Cliffs of Moher, County Clare Ireland

 

Focus stack of two images, one of the flower in the foreground and one of the cliffs in the back. Did not have a tripod so had to imrpovise

Refredis has had a little makeover, looking more like a thane now!

 

"Apple No Longer Immune to China’s Scrutiny of U.S. Tech Firms" by PAUL MOZUR and JANE PERLEZ via NYT t.co/oZ8YwQgDpe (via Twitter twitter.com/felipemassone/status/723315921503264768)

Today is World Arthritis Day 2011!

 

This year's theme is Move to Improve, by keeping active you can improve the way you feel

 

Many of you know I have Seronegative Rheumatoid Arthritis and Fybromyalgia. About 7 years ago literally overnight my joints one by one started 'flaring' up and it took a while to get a diagnosis as I was 'too young' according to a few people! But these auto immune diseases can affect anyone at any age.

 

I was quite ill for a while and couldn't do very much, I have been on a lot of nasty medications over the years and am now finally! on the Anti TNF waiting list, so next year I will be injecting myself with yet more drugs but I am hoping they will help slow down the progression of the disease.

 

The 'But you don't look sick' website comes to mind, as people can't 'see' pain so don't think there is anything 'wrong' with you, yes i'll go to the gym but ask me to carry a shopping bag, open a bottle or cut up my dinner! and i'll struggle.

 

Most of you also know I lead a (very!) active life, I try and not let this auto immune disease 'win', and this past year these trainers have been going to the gym a few times a week, zumba, spin, yoga, body balance amongst others. I find it tough going but I push myself to keep active and it does help me feel better in my mindset of dealing with the constant daily pain throughout my body. Best of all I have lost nearly 2 stone over the last year!

 

So yes there are dark days where the pain and fatigue leave you feeling pretty much useless but trying even a little gentle exercise - yoga, walking, swimming etc will help. And there are days were I do too much, then pay for it the following few days! like Edinburgh HPAD meet last weekend lol

 

This is for Carey, Steph and everyone else who has to deal with this in their lives xxx

 

Please favourite this and help me raise awareness - thank you x

 

www.worldarthritisday.org/

 

www.butyoudontlooksick.com/

 

whatisarthritis.co.uk/seronegative-rheumatoid-arthritis.html

www.arthritiscare.org.uk/Home

nras.org.uk/

I joke about many things but not illness. I have been ill for 20 yrs following a bout of Hepatits where I was bed ridden for 4 yrs, I was totally let down by the medical profession and deja vu has struck again. My wife following Pneumonia has had ME for nearly 12 yrs, she has been bed ridden for 2 yrs and 8mth. In Oct 2012 it was decided that she had to be admitted to hospital else she would die. 8mths on we are still waiting. This month is ME Awareness and I do all I can to raise it.

voicesfromtheshadowsfilm.co.uk/

dozydayz.co.uk/

www.youtube.com/watch?v=U1jgXEI8ngk&list=UU8i6jUphcG2...

An experimental therapy has brought prolonged remissions to a high proportion of patients who were facing death from advanced leukemia after standard treatments had failed, researchers are reporting.

 

The therapy involves genetically programming cells from the patient’s own immune system to fight the disease.

 

The research included 30 patients: five adults ages 26 to 60, and 25 children and young adults ages 5 to 22. All were severely ill, with acute lymphoblastic leukemia, and had relapsed several times or had never responded to typical therapies. In more than half, the disease had come back even after a stem-cell transplant, which usually gives patients the best hope of surviving. Their life expectancy was a few months, or in some cases just weeks.

 

Six months after being treated, 23 of the 30 patients were still alive, and 19 of them have remained in complete remission. (NY Times)

 

GRATEFUL a love song to the world

iss065e026426 (May 6, 2021) --- NASA astronaut and Expedition 65 Flight Engineer Megan McArthur services donor cells inside the Kibo laboratory module's Life Science Glovebox for the Celestial Immunity study. The human research investigation may provide insights into new vaccines and drugs possibly advancing the commercialization of space.

Mark and Megan have been working a lot on NASA's Celestial immunity experiment, including weekends. This is one of the reasons I like making timelapses, it compresses hours of work into a short video (also once the camera is set up we can let it be it and do said work). Together with solid support from mission control and scientists on ground, Mark and Megan have been working in the Life Sciences Glovebox in the Japanese Kibo laboratory to run this experiment. They are taking immune cells from elderly people and adults and seeing how they react to being on the International Space Station. This could offer clues to the whole ageing process in general and continues on ground-breaking research in space that is helping us understand the human body in detail. Like much human research in space it capitalises on the fact that cells seem to age faster offering a handy way for researchers to observe changes but sped up. Mark is doing the experiment in the Glovebox so the cells are contained, we do many biological or chemical experiments in gloveboxes for extra safety. youtu.be/vNS_sEfgvdI

 

Mark et Megan travaillent beaucoup sur l’expérience Celestial immunity dernièrement, y compris les weekends. Les timelapses ont l’avantage de compresser le temps et de montrer l’essentiel des activités en une courte vidéo (et puis je peux installer la caméra et la laisser tourner pendant que je vaque à mes occupations 🆗). Avec le soutien du centre d’opérations et des scientifiques, Megan et Mark utilisent la Life Sciences Glovebox (littéralement « la boîte à gants pour les sciences du vivant) qui se trouve dans le laboratoire :flag japon: Kibo. Grâce à cette boîte, les échantillons restent bien confiner, sans risque d’être abimés. Ils étudient des cellules immunitaires de personnes âgées et d’adultes pour voir comment elles réagissent dans la Station spatiale. L’objectif ? Étudier le vieillissement et plus généralement améliorer la compréhension du corps humain. Comme la plupart des études sur la physiologie humaine, on se sert du fait que les cellules vieillissent plus vite dans l’espace. C’est pratique, on peut observer les changements plus rapidement, comme en accélérer… un peu comme un timelapse dans la vie réelle :) youtu.be/vNS_sEfgvdI

  

Credits: ESA/NASA–T. Pesquet

  

527C3558

" With reins firmly gripped, dominance asserts its supremacy, impervious to redemption, immune to exchange. Beyond redemption, beyond price... 💕 "

 

_______ Miss Saphira

 

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. . . Femdom Tale . . .

 

Chaper: Her Masculinity Energy

 

☑ Masculinity isn't just a presence, it's a force.

☑ An aura of strength that commands respect and inspires trust.

☑ It's the unwavering resolve to shoulder responsibility, the quiet confidence to lead, and the unwavering hand that guides a couple through life's storms.

☑ It's the unwavering embrace that says, "Together, we face anything."

 

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In the world of Femdom, some guys feeling weak get attracted to dominant women, called dominas, because they give off strong vibes they don't have.

 

Masculinity isn't just about being macho, it's also about having confidence and power. Guys who feel they're not masculine enough look for dominas with masculine energy 'cause they admire these traits and 'wish they had that strength too.'

 

Sharing strength for men lacking masculinity is straightforward. It's not intricate. What complicates matters is the sub's denial of his own flaws.

 

Embrace your Domme's strength without dwelling on your own shortcomings. Build a new identity around her power and masculinity. In most femdom relationships, these aspects might symbolize unity, feeling like one with your lover. However, for her, it's distinct. It's not perceived as romantic, instead, it's seen as parasitic. Acknowledging this reality could strain romance, but it's a truth you must confront.

 

How do you live alongside her, coexist without becoming a burden? That's the question to ponder.

 

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. . . D/s Game . . .

 

Her game, His game, or Our game?

 

Whose game is it? Who's leading?

Who embodies masculinity and shoulders the weight of the relationship, embracing the responsibility of carrying their partner's weaknesses? That person emerges as the leader, shaping the dynamics of the game.

 

For someone unable to take the reins, failing to assume responsibility and manage the relationship, they become the oppressed one, a sub in the D/s power dynamic, compelled to chase after the leader's whims. Without the masculine energy to assert dominance, they forfeit the right to dictate the course of the relationship.

 

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Unspoken Realities: Taboos in Femdom Relationships

 

1. Using "Miss" to empower yourself, forge a new, independent identity. Instead of labeling them as parasites, the Miss must consider it a form of unity or oneness.

 

2. In exchange for 'honor and the right to dictate the game as well', some people negotiate with wealth, while others who don't pay - engage in rare romances and fetish offers.

 

Two easy deals that most Findom and Femdom practitioners accept and entertain, yet fail to seal the deal with her. He questioned, WHY??

 

1. Because, let's be real, a parasite is a parasite. Feeling as one and unity? (Amused)...That's on a whole different level of connection - feeling as one and unity belong to another realm of sharing. I'll keep labeling you as a parasite as long as you keep behaving like one, constantly leaning on my strength and responsibility.

 

2. Because, let's get this straight, as long as you're leeching off my masculine energy, you lose the right to call the shots. It can't be our game when I'm shouldering all your weaknesses and the weight of this D/s dynamic alone. You don't get to set the rules, you must chase after and follow my lead until you step up and show some real masculinity. I won't let you lead until you improve yourself.

 

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My casino, My rules, My allowed bets !

 

A: Why can't overflowing love and exclusive rare fetishes be taken as stakes? Why can't they be used as chips in your casino, Miss?

 

B: (throws back her head and laughs, a sultry sound that drips with amusement) Ah, because my love and fetishes are just as rare and wonderful as you, well, perhaps even more so. You know it well, it's a win-win. They can't be traded because you win I win already, you cannot use them as your breathtaking stakes, haha, keep this in mind, I'm not like your former dommies, unlike those dull dommes you've discarded, I won't be caught begging for scraps, whimpering for your embrace. I'm not the low-skill domina who was devoid of charisma, lacking in fetish skills to rely on, who had to beg for you like paupers pleading for alms, yearning for your embrace just to receive a morsel from your skills and charisma, letting you set your rules, lead the game and truly honor and adore you as the strong man while you're leeching and relying on her masculinity. No, darling, it's YOU who depends on me for this and as long as you depend on me, I won't let you rule by using love and fetishes as stakes!

 

A: "How much?!" His voice boomed, frustration crackling in the air. "Is that all this is to you? A damn price list?"

 

B: (A throaty laugh escaped her lips, laced with disdain.) "Price list? My dear boy, I don't want your money. I'm too real to let you pay to win my respect easily. Respect isn't something you can buy with a fistful of dollars. It's earned. Earned through genuine strength, not the kind that throws wallets around."

 

(A flicker of amusement danced in her eyes.) "To rule the game, to be honored, to be respected like a strong man? It requires masculinity and leadership to carry burdens, something you seem to be… lacking."

 

(Her voice dropped to a dangerous whisper.) "So, tell me, darling, are you ready to improve your power, step up and claim your position as the leader in this game, or are you content being a mere player… forever chasing after my approval?"

 

A: (Scoffs) "A whole cushion for my meltdown? That's awfully generous, Your Majesty! You sure know how to spoil a guy rotten." (Feigning indignation)

 

B: (Pats the cushion playfully) "Oh, hush now, big guy. Feeling a little flustered? Need a few days to unleash your inner beast on this innocent cushion? Scream, yell, curseeee your little heart out – the whole nine yards. But remember, darling, this throne" (gestures to the cushion) "has an expiration date. Once the tantrum's over, things go back to the usual. My rules are like the Bible, sweetheart - 'unbreakable!' And according to it, the one with the most masculinity and confidence gets to be in charge and rule the weaker one. Nothing can change that... 💕 "

 

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There is a superhighway between the brain and GI system that holds great sway over humans

"There is a muscle that encircles the gut like a lasso when we are sitting… creating a kink in the tube," Giulia Enders explains in Gut: The Inside Story of Our Body's Most Underrated Organ. She calls the mechanism "an extra insurance policy, in addition to our old friends, the sphincters" (you have two sphincters – keep reading) and cites studies showing that squatters, with their unkinked guts, are less susceptible to haemorrhoids and constipation.Enders, a 25-year-old student at the Institute for Microbiology in Frankfurt, inside an underground public lavatory in central London. "Is there a toilet in this toilet?" she asks when she arrives. There is not, a barista tells her. The Victorian urinals, abandoned in the 1960s, have been converted into cafe with booths and stools, and no room for anything else.After a dash to a pub loo above ground, Enders talks with infectious energy about the wonder of the gut. She has been delighted to discover how many people share her fascination with a subject that can suffer for being taboo. "Even today in the taxi, I told the driver what I was doing and within about two minutes he was telling me about his constipation," she says in perfect English, which she owes to a year of study in the US. "And it's not just him. It's ladies with chic hair at big gala dinners, too. Everyone wants to talk about it."Enders first got noticed after a self-assured turn at a science slam in Berlin three years ago. Her 10-minute lecture went viral on YouTube, and now, weeks after completing her final exams as a doctoral student, she is a publishing sensation. Her book, called Darm Mit Charme ("Charming Bowels") in Germany, has sold more than 1.3 million copies since it came out last year. Rights have been sold to dozens of countries.

 

Her way into the gut is a lightness that some reviewers have found too childish or lacking in scientific rigour to be taken seriously. But there is something compelling and refreshing about her curiosity and popular approach. "When I read the research, I think, why don't people know about this – why am I reading about it in some paper or specialist magazine? It's ridiculous because everyone has to deal with it on a daily basis." After she explains the inspiration for her fixation (the suicide of an acquaintance who had had severe halitosis, and her own teenage skin condition, which turned out to have been caused by a wheat intolerance) Enders starts at the end of the digestive tract with what she calls the "masterly performance" that is defecation. "There is so much about the anus that we don't know," she says, reaching for a gluten-free chocolate chip cookie. "The first surprise is the sophistication of our sphincters… you know about the outer one because you can control it, but the inner one nobody knows about."

This inner opening is beyond our conscious control, releasing waste material into a sort of anal vestibule where, in Enders words, "a small taster" hits sensor cells that tell the body what it's dealing with and how to respond using the outer sphincter. This opening, and our mouths, are the recognisable and controllable ends of a system that, stretched out, would be almost as long as a bus. But it's the bits in between, and their link with the rest of our bodies, including our brains and emotions, that really interest Enders.

 

"Medical diagrams show the small intestine as a sausage thing chaotically going through our belly," she says. "But it is an extraordinary work of architecture that moves so harmonically when you see it during surgery. It's clean and smooth, like soft fabric, and moves like this." She performs a wavy, pulsating motion with her hands. Enders believes that if we could think differently about the gut, we might more readily understand its role beyond basic digestion – and be kinder to it. The great extent to which the gut can influence health and mood is a growing field in medicine. We speak of it all the time, whether we describe "gut feelings", "butterflies in our stomachs", or "pooing our pants" in fear, but popular understanding of this gut-brain axis remains low.

 

A primal connection exists between our brain and our gut. We often talk about a “gut feeling” when we meet someone for the first time. We’re told to “trust our gut instinct” when making a difficult decision or that it’s “gut check time” when faced with a situation that tests our nerve and determination. This mind-gut connection is not just metaphorical. Our brain and gut are connected by an extensive network of neurons and a highway of chemicals and hormones that constantly provide feedback about how hungry we are, whether or not we’re experiencing stress, or if we’ve ingested a disease-causing microbe. This information superhighway is called the brain-gut axis and it provides constant updates on the state of affairs at your two ends. That sinking feeling in the pit of your stomach after looking at your postholiday credit card bill is a vivid example of the brain-gut connection at work. You’re stressed and your gut knows it—immediately.

 

The enteric nervous system is often referred to as our body’s second brain. There are hundreds of million of neurons connecting the brain to the enteric nervous system, the part of the nervous system that is tasked with controlling the gastrointestinal system. This vast web of connections monitors the entire digestive tract from the esophagus to the anus. The enteric nervous system is so extensive that it can operate as an independent entity without input from our central nervous system, although they are in regular communication. While our “second” brain cannot compose a symphony or paint a masterpiece the way the brain in our skull can, it does perform an important role in managing the workings of our inner tube. The network of neurons in the gut is as plentiful and complex as the network of neurons in our spinal cord, which may seem overly complex just to keep track of digestion. Why is our gut the only organ in our body that needs its own “brain”? Is it just to manage the process of digestion? Or could it be that one job of our second brain is to listen in on the trillions of microbes residing in the gut?

 

Operations of the enteric nervous system are overseen by the brain and central nervous system. The central nervous system is in communication with the gut via the sympathetic and parasympathetic branches of the autonomic nervous system, the involuntary arm of the nervous system that controls heart rate, breathing, and digestion. The autonomic nervous system is tasked with the job of regulating the speed at which food transits through the gut, the secretion of acid in our stomach, and the production of mucus on the intestinal lining. The hypothalamic-pituitary-adrenal axis, or HPA axis, is another mechanism by which the brain can communicate with the gut to help control digestion through the action of hormones.

 

This circuitry of neurons, hormones, and chemical neurotransmitters not only sends messages to the brain about the status of our gut, it allows for the brain to directly impact the gut environment. The rate at which food is being moved and how much mucus is lining the gut—both of which can be controlled by the central nervous system—have a direct impact on the environmental conditions the microbiota experiences.

 

Like any ecosystem inhabited by competing species, the environment within the gut dictates which inhabitants thrive. Just as creatures adapted to a moist rain forest would struggle in the desert, microbes relying on the mucus layer will struggle in a gut where mucus is exceedingly sparse and thin. Bulk up the mucus, and the mucus-adapted microbes can stage a comeback. The nervous system, through its ability to affect gut transit time and mucus secretion, can help dictate which microbes inhabit the gut. In this case, even if the decisions are not conscious, it’s mind over microbes.

 

What about the microbial side? When the microbiota adjusts to a change in diet or to a stress-induced decrease in gut transit time, is the brain made aware of this modification? Does the brain-gut axis run in one direction only, with all signals going from brain to gut, or are some signals going the other way? Is that voice in your head that is asking for a snack coming from your mind or is it emanating from the insatiable masses in your bowels? Recent evidence indicates that not only is our brain “aware” of our gut microbes, but these bacteria can influence our perception of the world and alter our behavior. It is becoming clear that the influence of our microbiota reaches far beyond the gut to affect an aspect of our biology few would have predicted—our mind.

 

For example, the gut microbiota influences the body’s level of the potent neurotransmitter serotonin, which regulates feelings of happiness. Some of the most prescribed drugs in the U.S. for treating anxiety and depression, like Prozac, Zoloft, and Paxil, work by modulating levels of serotonin. And serotonin is likely just one of a numerous biochemical messengers dictating our mood and behavior that the microbiota impacts.

 

Most of us can relate to the experience of having butterflies in our stomach, or to a visceral gut-wrenching feeling, and how often are we told not to ignore our “gut-instinct” or “gut-feeling” when making a decision.

 

Even from our simple slang, it’s clear just how symbolically connected the gut is to our emotions. Now, there’s tangible proof to support these popular metaphors.

 

We all have a microbiome, and they are as unique as our neural pathways

Research has shown that the body is actually composed of more bacteria than cells. We are more bug than human! Collectively, these trillions of bacteria are called the microbiome. Most of those bacteria reside in our gut, sometimes referred to as the gut microbiota, and they play multiple roles in our overall health.

 

The gut is no longer seen as an entity with the sole purpose of helping with all aspects of digestion. It’s also being considered as a key player in regulating inflammation and immunity.

 

A healthy gut consists of different iterations of bacteria for different people, and this diversity maintains wellness. A shift away from “normal” gut microbiota diversity is called dysbiosis, and dysbiosis may contribute to disease. In light of this, the microbiome has become the focus of much research attention as a new way of understanding autoimmune, gastrointestinal, and even brain disorders.

 

The benefit of a healthy gut is illustrated most effectively during early development. Research has indicated just how sensitive a fetus is to any changes in a mother’s microbiotic makeup, so much so that it can alter the way a baby’s brain develops. If a baby is born via cesarean section, it misses an opportunity to ingest the mother’s bacteria as it travels down the vaginal canal. Studies show that those born via c-section have to work to regain the same diversity in their microbiome as those born vaginally. Throughout our lives, our microbiome continues to be a vulnerable entity, and as we are exposed to stress, toxins, chemicals, certain diets, and even exercise, our microbiome fluctuates for better or worse.

 

The gut as second brain

Our gut microbiota play a vital role in our physical and psychological health via its own neural network: the enteric nervous system (ENS), a complex system of about 100 million nerves found in the lining of the gut.

 

The ENS is sometimes called the “second brain,” and it actually arises from the same tissues as our central nervous system (CNS) during fetal development. Therefore, it has many structural and chemical parallels to the brain.

 

Our ENS doesn’t wax philosophical or make executive decisions like the gray shiny mound in our skulls. Yet, in a miraculously orchestrated symphony of hormones, neurotransmitters, and electrical impulses through a pathway of nerves, both “brains” communicate back and forth. These pathways include and involve endocrine, immune, and neural pathways.

 

At this point in time, even though the research is inchoate and complex, it is clear that the brain and gut are so intimately connected that it sometimes seems like one system, not two.

 

Our emotions play a big role in functional gastrointestinal disorders

Given how closely the gut and brain interact, it has become clear that emotional and psychosocial factors can trigger symptoms in the gut. This is especially true in cases when the gut is acting up and there’s no obvious physical cause.

 

The functional gastrointestinal disorders (FGIDs) are a group of more than 20 chronic and hard to treat medical conditions of the gastrointestinal tract that constitute a large proportion of the presenting problems seen in clinical gastroenterology.

 

While FGID’s were once thought to be partly “in one’s head,” a more precise conceptualization of these difficulties posits that psychosocial factors influence the actual physiology of the gut, as well as the modulation of symptoms. In other words, psychological factors can literally impact upon physical factors, like the movement and contractions of the GI tract, causing, inflammation, pain, and other bowel symptoms.

 

Mental health impacts gut wellness

In light of this new understanding, it might be impossible to heal FGID’s without considering the impact of stress and emotion. Studies have shown that patients who tried psychologically based approaches had greater improvement in their symptoms compared with patients who received conventional medical treatment.

 

Along those lines, a new pilot study from Harvard University affiliates Benson-Henry Institute for Mind Body Medicine at Massachusetts General Hospital and Beth Israel Deaconess Medical Center found that meditation could have a significant impact for those with irritable bowel syndrome and inflammatory bowel disease. Forty-eight patients with either IBS or IBD took a 9-week session that included meditation training, and the results showed reduced pain, improved symptoms, stress reduction, and the change in expression of genes that contribute to inflammation.

 

Poor gut health can lead to neurological and neuropsychiatric disorders

Vice-versa, poor gut health has been implicated in neurological and neuropsychiatric disorders. Disturbances in gut health have been linked to multiple sclerosis, autistic spectrum disorders, and Parkinson’s disease. This is potentially related to pro-inflammatory states elicited by gut dysbiosis-microbial imbalance on or inside the body. Additional connections between age-related gut changes and Alzheimer’s disease have also been made.

 

Further, there is now research that is dubbing depression as an inflammatory disorder mediated by poor gut health. In fact, multiple animal studies have shown that manipulating the gut microbiota in some way can produce behaviors related to anxiety and depression. (Maes, Kubera, Leunis, Berk, J. Affective Disorders, 2012 and Berk, Williams, Jacka, BMC Med, 2013).

 

Our brain’s health, which will be discussed in more depth in a later blog post, is dependent on many lifestyle choices that mediate gut health; including most notably diet (i.e., reduction of excess sugar and refined carbohydrates) and pre and probiotic intake.

 

The brain-gut connection has treatment implications

We are now faced with the possibility of both prevention and treatment of neurological/neuropsychiatric difficulties via proper gut health. On the flip side, stress-reduction and other psychological treatments can help prevent and treat gastrointestinal disorders. This discovery can potentially lead to reduced morbidity, impairment, and chronic dependency on health care resources.

 

The most empowering aspect to the gut-brain connection is the understanding that many of our daily lifestyle choices play a role in mediating our overall wellness. This whole-body approach to healthcare and wellness continues to show its value in our longevity, well-being, and quality of life: that both physical and mental health go hand-in-hand.

 

www.mindful.org/meet-your-second-brain-the-gut/

 

The Kliment Voroshilov (KV) tanks were a series of Soviet heavy tanks, named after the Soviet defense commissar and politician Kliment Voroshilov. The KV series were known for their extremely heavy armour protection during the early war, especially during the first year of the invasion of the Soviet Union in World War II. Almost completely immune to the 3.7 cm KwK 36 and howitzer-like, short barreled 7.5 cm KwK 37 guns mounted respectively on the early Panzer III and Panzer IV tanks, until better guns were developed often the only way to defeat a KV was a point-blank shot to the rear. Prior to the invasion, about 500 of the over 22,000 tanks in Soviet service at the time were of the KV-1 type. When the KV-1 appeared, it outclassed the French Char B1, the only heavy tank used in the world at that time. Yet in the end it turned out that there was little sense in producing the expensive KV tanks, as the T-34 medium tank performed better (or at least equally) in all practical respects. Later in the war, the KV series became a base of development of the Iosif Stalin tanks.

Development

After disappointing results with the multi-turreted T-35 heavy tank, Soviet tank designers started drawing up replacements. The T-35 conformed to the 1920s notion of a 'breakthrough tank' with very heavy firepower and armour protection, but suffered from poor mobility. The Spanish Civil War demonstrated the need for much heavier armor on tanks, and was the main influence on Soviet tank design just prior to World War II.

 

Several competing designs were offered, and even more were drawn up prior to reaching prototype stage. All had heavy armour, torsion-bar suspension, wide tracks, and were of welded and cast construction. One of the main competing designs was the SMK, which in its final form had two turrets, mounting the same combination of 76.2 mm and 45 mm weapons. The designers of the SMK independently drew up a single-turreted variant and this received approval at the highest level. Two of these, named after the People's Defence Commissioner were ordered alongside a single SMK. The smaller hull and single turret enabled the designer to install heavy frontal and turret armour while keeping the weight within manageable limits.

  

When the Soviets entered the Winter War, the SMK, KV and a third design, the T-100, were sent to be tested in combat conditions. The KV outperformed the SMK and T-100 designs. The KV's heavy armour proved highly resistant to Finnish anti-tank weapons, making it more difficult to stop. In 1939 production of 50 KV was ordered. During the War, the Soviets found it difficult to deal with the concrete bunkers used by the Finns and a request was made for a tank with a large howitzer. One of the rush projects to meet the request put the howitzer in a new turret on one of the KV tanks.

 

Initially known as Little Turret and Big turret, the 76-mm-armed tank was designated as the KV-1 Heavy Tank and the 152 mm howitzer one as KV-2 Heavy Artillery Tank.

 

The KV's strengths included armor that was impenetrable by any tank-mounted weapon then in service except at point-blank range, that it had good firepower, and that it had good traction on soft ground. It also had serious flaws: it was difficult to steer, the transmission (which was a twenty year old Caterpillar design) was unreliable (and was known to have to be shifted with a hammer),[6] and the ergonomics were poor, with limited visibility and no turret basket. Furthermore, at 45 tons, it was simply too heavy. This severely impacted the maneuverability, not so much in terms of maximum speed, as through inability to cross many bridges medium tanks could cross. The KV outweighed most other tanks of the era, being about twice as heavy as the heaviest contemporary German tank. KVs were never equipped with a snorkeling system to ford shallow rivers, so they had to be left to travel to an adequate bridge. As applique armor and other improvements were added without increasing engine power, later models were less capable of keeping up to speed with medium tanks and had more trouble with difficult terrain. In addition, its firepower was no better than the T-34. It took field reports from senior commanders "and certified heroes", who could be honest without risk of punishment, to reveal "what a dog the KV-1.

By 1942, when the Germans were fielding large numbers of long-barrelled 50 mm and 75 mm guns, the KV's armor was no longer invincible. The KV-1's side, top, and turret armor could also be penetrated by the high-velocity MK 101 carried by German ground attack aircraft such as the Henschel Hs 129, requiring the installation of additional field-expedient appliqué armour. The KV-1's 76.2 mm gun also came in for criticism. While adequate against all German tanks, it was the same gun as carried by smaller, faster, and cheaper T-34 medium tanks. In 1943, it was determined that this gun could not penetrate the frontal armour of the new Tiger,the first German heavy tank, fortunately captured near Leningrad. The KV-1 was also much more difficult to manufacture and thus more expensive than the T-34. In short, its advantages no longer outweighed its drawbacks.

 

Nonetheless, because of its initial superior performance, the KV-1 was chosen as one of the few tanks to continue being built following the Soviet reorganization of tank production. Due to the new standardization, it shared the similar engine (the KV used a 600 hp V-2K modification of the T-34's V-2 diesel engine) and gun (the KV had a ZiS-5 main gun, while the T-34 had a similar F-34 main gun) as the T-34, was built in large quantities, and received frequent upgrades.

When production shifted to the Ural Mountains 'Tankograd' complex, the KV-2 was dropped. While impressive on paper, it had been designed as a slow-moving bunker-buster. It was less useful in highly mobile, fluid warfare that developed in World War II. The turret was so heavy it was difficult to traverse on non-level terrain, and it was expensive to produce. Only about 300 KV-2s were made, all in 1940-41, making it one of the rarer Soviet tanks. Many KV-2s were later converted into KV-1s.

As the war continued, the KV-1 continued to get more armour to compensate for the increasing effectiveness of German weapons. This culminated in the KV-1 model 1942 (German designation KV-1C), which had very heavy armour, but lacked a corresponding improvement to the engine. Tankers complained that although they were well-protected, their mobility was poor and they had no firepower advantage over the T-34 medium tank.[citation needed]

 

In response to criticisms, the lighter KV-1S (Russian language: КВ-1С) was released, with thinner armour and a smaller, lower turret in order to reclaim some speed. Importantly, the KV-1S also had a commander's cupola with all-around vision blocks, a first for a Soviet heavy tank. However, the thinning-out of the armor called into question why the tank was being produced at all, when the T-34 could seemingly do everything the KV could do and much more cheaply. The Soviet heavy tank program was close to cancellation in mid-1943.

 

The appearance of the German Panther tank in the summer of 1943 convinced the Red Army to make a serious upgrade of its tank force for the first time since 1941. Soviet tanks needed bigger guns to take on the growing numbers of Panthers and the few Tigers.

 

A stopgap upgrade to the KV series was the short-lived KV-85 or Objekt 239. This was a KV-1S with a new turret designed for the IS-85, mounting the same 85 mm D-5T gun as the SU-85 and early versions of the T-34-85; demand for the gun slowed production of the KV-85 tremendously and only 148 were built before the KV design was replaced. The KV-85 was produced in the fall and winter of 1943-44; they were sent to the front as of September 1943 and production of the KV-85 was stopped by the spring of 1944 once the IS-2 entered full scale production.

Successor

 

A new heavy tank design entered production late in 1943 based on the work done on the KV-13. Because Kliment Voroshilov had fallen out of political favour, the new heavy tank series was named the Iosif Stalin tank, after Iosif (Joseph) Stalin. The KV-13 program's IS-85 prototype was accepted for production as the IS-1 (or IS-85, Object 237) heavy tank. After testing with both 100 mm and 122 mm guns, the D-25T 122 mm gun was selected as the main armament of the new tank, primarily because of its ready availability and the effect of its large high-explosive shell when attacking German fortifications. The 122mm D-25T used a separate shell and powder charge, resulting in a lower rate of fire and reduced ammunition capacity. While the 122mm armour piercing shell had a lower muzzle velocity than similar late German 7.5 cm and 8.8 cm guns, proving-ground tests showed that the 122mm AP shell could defeat the frontal armour of the German Panther tank, and the HE shell would easily blow off the drive sprocket and tread of the heaviest German tank or self-propelled gun. The IS-122 replaced the IS-85, and began mass production as the IS-2. The 85 mm gun saw service in the lighter SU-85 and T-34-85.

  

A destroyed Soviet KV-1 in Olonets, September 1941, during the Continuation War

Some KVs remained in service right up to the end of the war, although in greatly diminishing numbers as they wore out or were knocked out. The 260th Guards Heavy Breakthrough Tank Regiment, based on the Leningrad front, operated a number of 1941-vintage KV-1s at least as late as the summer of 1944 before re-equipping with IS-2s. A regiment of KVs saw service in Manchuria in August 1945, and a few KV-85s were used in the Crimea in the summer of 1944. The Finnish forces had two KVs, nicknamed Klimi, a Model 1940 and Model 1941, both of which received minor upgrades in their service, and both of which survived the war. A single captured KV-2 was used by German forces in 1945 against US forces in the Ruhr.

  

Specifications (KV-1 Model 1941)

Weight - 45 tonnes

Length - 6.75 m (22 ft 2 in)

Width - 3.32 m (10 ft 11 in)

Height -2.71 m (8 ft 11 in)

Crew - 5

Armour - 90 mm maximum

Main armament -76.2 mm model F-34 gun

Secondary armament - 3× or 4× DT machine guns

Engine - 12-cylinder diesel model V-2 600 hp (450 kW)

Power/weight - 13 hp/tonne

Suspension - Torsion bar

Operational range - 335 km

Speed - 35 km/h (22 mph)

   

This cap provide valuable buffs like invisibility, immunity to crowd control, or increased that "Plutonic Theory",was the idea that the earth was formed due to intense heat in the earth, stems from Pluto, the opposing theory of which is the Neptunian Theory which states that the formation of the earth was caused by the agency of water.Pluto was originally not the god of the underworld. Pluto is cognate with the Greek word "Ploutos" (wealth, cf. plutocracy), and, under the original name Plutus, was considered by the Romans as the giver of gold, silver, and other subterranean substances. Because these "gifts" were mined, Pluto became recognized as the god of the physical underworld, which in turn helped him become recognized as the god of the spiritual underworld and thus death. This brought about his mythological relationship to the Greek god Hades. Because the mythology of these gods is more known than the actual religious roles of the gods, Pluto is identified as the counterpart to the Greek Hades (which is only true in mythology).

Hades's Cap of Invisibility (ハデスの隠れ兜, Hadesu no Kakure Kabuto?), also called the Cloth of Concealment (身隠しの布, Mikakushi no Nuno?), is the cap of invisibility owned by Hades. It is the prototype of all Noble Phantasms that “hides the figure.” Normally kept by Gilgamesh in the form of a sash, anything covered or enclosed by the cloth cannot be observed through magecraft and optical means. Using optical magic to block all forms of magical detection and any presence of magical emanations from the wearer, it is incredibly effective against those relying solely on magecraft to detect enemies. It does not obscure sound, smell, body temperature, or the wearer's tracks, so its usage is mostly situational. Without such indicators being readily apparent, it is possible to easily walk by enemies while keeping quiet, and it allows for the easy kidnapping of others through Bounded Fields without detection. While in its sash form, it can be held by multiple people at once, and it can wrap up itself automatically to return to its cap form. The cloth of which it is made of is of a very complex weave estimated to have "reached five dimensions", and complete reproduction of the cloth is impossible for humans.

In classical mythology, the Cap of Invisibility (Ἄϊδος κυνέην (H)aidos kuneēn in Greek, lit. dog-skin of Hades) is a helmet or cap that can turn the wearer invisible. It is also known as the Cap of Hades, Helm of Hades,[2] or Helm of Darkness. Wearers of the cap in Greek myths include Athena, the goddess of wisdom, the messenger god Hermes, and the hero Perseus. The Cap of Invisibility enables the user to become invisible to other supernatural entities, functioning much like the cloud of mist that the gods surround themselves in to become undetectable. Invisibility is found on Blue Entoloma, Namira's Rot, Nirnroot, & Spider Egg so you'll need at least 2 of these reagents. Also you must avoid all reagents with Detection: Cornflower, Torchbug Thorax, White Cap, or Wormwood.So find things that combine with up to 2 of the invisibility reagents without using the Detection reagents. If by recovery you mean Stamina Recovery, you're out of luck as there are no reagents which both restore Stamina and grant Invisibility, making it impossible to get pairs for both effects with at most 3 reagents. If you mean Health Recovery, you can start with Blue Entoloma as your common reagent for both Invisibility & Restore Health, adding in one other Invisibility reagent (Namira's Rot or Spider Egg -- avoiding Nirnroot because of its Ravage Health property) and one other Restore Health reagent (Bugloss, Butterfly Wing, Columbine, Luminous Russula, Mountain Flower, or Water Hyacinth). Which other reagents you choose aside from Blue Entoloma will determine what other effects you may receive. Using Blue Entoloma, Butterfly Wing, + Spider Egg would add both Restore Health & Sustained Restore Health to Invisibilty. Or using Blue Entoloma, Namira's Rot, + Columbine would add immune to knockback/disabling effects to the Restore Health & Invisibility. The helmet of invisibility was a magical item of Hades. Hades gave the helmet to Perseus, to help him on his quest to retrieve Medusa's Head and kill the Kraken. However, Hades was under the orders of Zeus. Perseus used it to sneak into Andromeda's room where he witnessed her spirit being taken away by a giant vulture. He then uses it again the next night but follows the vulture to Calibos' Lair. There, he witnesses Calibos giving Andromeda's Spirit a new riddle.THis is a scam In the end, Calibos figures out that Perseus is there and attacks him, but Perseus manages to escape. However, The Helmet of Invisibility then falls into the swamp and vanishes forever. Because of this, Zeus orders Athena to give Perseus her owl, but she denies and tells Hephaestus to make a mechanical version.

 

Square is the emblem of the created world and nature as opposed to the uncreated and the creator... square and cube symbolize fixation and stability and are associated with earth....The square allows the man an orientation in the horizontal plane. He's got imposes on chaos a system of four cardinal directions to order the world. This spatial orientation gives rise to square and orthogonal shapes emblematic of the habitat of sedentary populations. The square and cube symbolize fixation and stability and are associated with earth. The sky covers, the earth supports. The square symbolizes the earth and Man in its imperfection. In the case of the semi-square, it is the complementarity of the visible and the invisible. In China, in the texts of the Ancients of the Tao, it was told:"Heaven is a Round, the Earth is a Square". In Beijing, the forbidden city, which is the seat and symbol of power, is structured squarely, while the palace of heaven, which symbolizes spirituality and the divine, is made up of three circular monuments.

In Mecca, pilgrims walk around the Kaaba cube in a circular way. Through this act of faith, Islam spiritually squares the circle. The square is the construction plan of many temples (Angkor in Cambodia, Borobudur to Java) but they are very often written in circular spaces (hilltop, circle of hills) or surmounted by circular shapes (stupas). If the Ka' ba of Mecca is presented as a square shape, the faithful followers of the ka' ba of Mecca move around describing circular routes. In India, in the drawings of meditation mandalas, one can see the circle and the square associated with it. They represent the ideal harmony of a couple of opposites, heaven and earth, divine and human. Although the properties of the square are strictly opposed to those of the circle, these two geometric figures are associated, especially in religious architecture. Indeed, often, the base of the buildings present a square structure to symbolize the earth, while their circular roofs symbolize the sky.

 

The square in a vertical position, close to the diamond, indicates the dynamics of the square, the movement, i. e. the principle of life. It shall describe methods for working with these Magic Squares to construct and charge sigils. The mathematical definition of a Magic Square is an arrangement of distinct integers in a square grid in which the integers of each row, column and diagonal all add up to the same number. While a full exploration into the history of Magic Squares is beyond our current scope, suffice it to say that their use in mathematics and mysticism is well documented in Asia as early as the 7th century B.C.E. By the early Renaissance, Magic Squares were popularized in Europe and made their way into western magical traditions via the later writings of Marsilio Ficino, Pico della Mirandola, and Cornelius Agrippa. Of primary importance to this post is a grouping of seven squares between the orders of 3 and 9 that were identified as planetary in nature. These were each attributed to one of the seven classical planets based on the emanation sequence of the kabbalistic sefirah associate with that planet.The square summarizes the symbolism of the number four, order of the Universe and the necessary opposition of opposites. It is a symbol of unity, wholeness and balance of the four psychic functions: thought, sensation, intuition, feeling. "The square is an anti-dynamic figure that is anchored on four sides. This symbolizes the stop, or the instant sampled. The square implies an notion of stagnation, solidification and perhaps even stabilisation in perfection "(Jean Chevalier - Alain Gheerbrant).It also represents the four directions of the compass and thus allows man to orientate himself in space. The square establishes a coordinate system. It imposes a structure on chaos and brings order to the world. In his work,"Signs, symbols and myths", Luc Benoist explains this point:"If the earth is characterized by the square, it is because the sun fixes its axes thanks to the extreme points of its course, which divides it into four parts, each representing a season, at the same time as one of the cardinal points".

  

the hatchets in the blood

 

#immunity #fuckcancer come help #cutitup #creativeImagination #imagineHeath #mandala #process

 

artist creating through it : tinyurl.com/y68cgm7a

 

My first baking experience , Pineapple bread , tastes like semi sweet cake , Martin’s Photographs , a Lonely Good Friday exercise , because i cannot be to close to Family and friends , physical distancing , because of my compromised immune system , good time learning new skills and having fun doing so , Ajax , Ontario , Canada , April 10. 2020

 

Exercise

IPhone XR

Pineapple bread

My first baking experience

Martin’s photographs

Lonely Good Friday

Physical distancing

Friends

New baking skills

Bread

Baking

Close to family and friends

Compromised immune system

C.L.L.

You all have a good and safe Easter weekend

Having fun doing so

Ajax

Ontario

Canada

April 10 2020

April 2020

Good time learning new skills and having fun doing so !

Not to close to family and friends

via Instagram ift.tt/2j6rsxI

The Yellow-Collared Scape Moth (Cisseps fulvicollis) has long black wings, an abdomen of iridescent blue, and a bright yellow or orange collar, from which it takes its name. Since many tend to have a more orange collar, it is also known by its other common name, Orange-Collared Scape Moth.

 

While the moth above is enjoying some "Hillside Pink Sheffield" variety chrysanthemums, Yellow-collared scape moths are frequently found on flowers of Eupatorium, a genus of flowering plants in the aster family, Asteraceae. Eupatorium are toxic to most animals. However the moths have developed a tolerance against the toxins. Males feed on these plants and acquire and store the toxins. Later they transfer them to the females as a mating gift. In turn females use the toxins to protect their eggs against predators. I wonder if there are any other cases of sexually-acquired protection in Nature? I'm sure there must be.

iss065e023172 (May 6, 2021) --- NASA astronaut and Expedition 65 Flight Engineer Megan McArthur services donor cells inside the Kibo laboratory module's Life Science Glovebox for the Celestial Immunity study. The human research investigation may provide insights into new vaccines and drugs possibly advancing the commercialization of space.

iss065e018996 (May 4, 2021) --- NASA astronaut and Expedition 65 Flight Engineer Mark Vande Hei works inside the Life Science Glovebox (LSG) for the Celestial Immunity study that may provide insights into new vaccines and drugs possibly advancing the commercialization of space. The LSG is located in the Kibo laboratory module from the Japan Aerospace Exploration Agency.

iss065e058810 (May 22, 2021) --- NASA astronaut and Expedition 65 Flight Engineer Mark Vande Hei services donor cell samples inside the Kibo laboratory module's Life Science Glovebox. The samples for the Celestial Immunity study are compared to cell cultures harvested on Earth and may help scientists develop new vaccines and drugs to treat diseases on Earth.

iss065e018995 (May 4, 2021) --- NASA astronaut and Expedition 65 Flight Engineer Mark Vande Hei works inside the Life Science Glovebox (LSG) for the Celestial Immunity study that may provide insights into new vaccines and drugs possibly advancing the commercialization of space. The LSG is located in the Kibo laboratory module from the Japan Aerospace Exploration Agency.

Different forms of fluctuations of the terrestrial gravity field are observed by gravity experiments. For example, atmospheric pressure fluctuations generate a gravity-noise foreground in measurements with super-conducting gravimeters. Gravity changes caused by high-magnitude earthquakes have been detected with the satellite gravity experiment GRACE, and we expect high-frequency terrestrial gravity fluctuations produced by ambient seismic fields to limit the sensitivity of ground-based gravitational-wave (GW) detectors. Accordingly, terrestrial gravity fluctuations are considered noise and signal depending on the experiment. Here, we will focus on ground-based gravimetry. This field is rapidly progressing through the development of GW detectors. The technology is pushed to its current limits in the advanced generation of the LIGO and Virgo detectors, targeting gravity strain sensitivities better than 10−23 Hz−1/2 above a few tens of a Hz. Alternative designs for GW detectors evolving from traditional gravity gradiometers such as torsion bars, atom interferometers, and superconducting gradiometers are currently being developed to extend the detection band to frequencies below 1 Hz. The goal of this article is to provide the analytical framework to describe terrestrial gravity perturbations in these experiments. Models of terrestrial gravity perturbations related to seismic fields, atmospheric disturbances, and vibrating, rotating or moving objects, are derived and analyzed. The models are then used to evaluate passive and active gravity noise mitigation strategies in GW detectors, or alternatively, to describe their potential use in geophysics. The article reviews the current state of the field, and also presents new analyses especially with respect to the impact of seismic scattering on gravity perturbations, active gravity noise cancellation, and time-domain models of gravity perturbations from atmospheric and seismic point sources. Our understanding of terrestrial gravity fluctuations will have great impact on the future development of GW detectors and high-precision gravimetry in general, and many open questions need to be answered still as emphasized in this article.

 

Keywords: Terrestrial gravity, Newtonian noise, Wiener filter, Mitigation

Go to:

Introduction

In the coming years, we will see a transition in the field of high-precision gravimetry from observations of slow lasting changes of the gravity field to the experimental study of fast gravity fluctuations. The latter will be realized by the advanced generation of the US-based LIGO [1] and Europe-based Virgo [7] gravitational-wave (GW) detectors. Their goal is to directly observe for the first time GWs that are produced by astrophysical sources such as inspiraling and merging neutron-star or black-hole binaries. Feasibility of the laser-interferometric detector concept has been demonstrated successfully with the first generation of detectors, which, in addition to the initial LIGO and Virgo detectors, also includes the GEO600 [119] and TAMA300 [161] detectors, and several prototypes around the world. The impact of these projects onto the field is two-fold. First of all, the direct detection of GWs will be a milestone in science opening a new window to our universe, and marking the beginning of a new era in observational astronomy. Second, several groups around the world have already started to adapt the technology to novel interferometer concepts [60, 155], with potential applications not only in GW science, but also geophysics. The basic measurement scheme is always the same: the relative displacement of test masses is monitored by using ultra-stable lasers. Progress in this field is strongly dependent on how well the motion of the test masses can be shielded from the environment. Test masses are placed in vacuum and are either freely falling (e.g., atom clouds [137]), or suspended and seismically isolated (e.g., high-quality glass or crystal mirrors as used in all of the detectors listed above). The best seismic isolations realized so far are effective above a few Hz, which limits the frequency range of detectable gravity fluctuations. Nonetheless, low-frequency concepts are continuously improving, and it is conceivable that future detectors will be sufficiently sensitive to detect GWs well below a Hz [88].

 

Terrestrial gravity perturbations were identified as a potential noise source already in the first concept laid out for a laser-interferometric GW detector [171]. Today, this form of noise is known as “terrestrial gravitational noise”, “Newtonian noise”, or “gravity-gradient noise”. It has never been observed in GW detectors, but it is predicted to limit the sensitivity of the advanced GW detectors at low frequencies. The most important source of gravity noise comes from fluctuating seismic fields [151]. Gravity perturbations from atmospheric disturbances such as pressure and temperature fluctuations can become significant at lower frequencies [51]. Anthropogenic sources of gravity perturbations are easier to avoid, but could also be relevant at lower frequencies [163]. Today, we only have one example of a direct observation of gravity fluctuations, i.e., from pressure fluctuations of the atmosphere in high-precision gravimeters [128]. Therefore, almost our entire understanding of gravity fluctuations is based on models. Nonetheless, potential sensitivity limits of future large-scale GW detectors need to be identified and characterized well in advance, and so there is a need to continuously improve our understanding of terrestrial gravity noise. Based on our current understanding, the preferred option is to construct future GW detectors underground to avoid the most dominant Newtonian-noise contributions. This choice was made for the next-generation Japanese GW detector KAGRA, which is currently being constructed underground at the Kamioka site [17], and also as part of a design study for the Einstein Telescope in Europe [140, 139]. While the benefit from underground construction with respect to gravity noise is expected to be substantial in GW detectors sensitive above a few Hz [27], it can be argued that it is less effective at lower frequencies [88].

 

Alternative mitigation strategies includes coherent noise cancellation [42]. The idea is to monitor the sources of gravity perturbations using auxiliary sensors such as microphones and seismometers, and to use their data to generate a coherent prediction of gravity noise. This technique is successfully applied in gravimeters to reduce the foreground of atmospheric gravity noise using collocated pressure sensors [128]. It is also noteworthy that the models of the atmospheric gravity noise are consistent with observations. This should give us some confidence at least that coherent Newtonian-noise cancellation can also be achieved in GW detectors. It is evident though that a model-based prediction of the performance of coherent noise cancellation schemes is prone to systematic errors as long as the properties of the sources are not fully understood. Ongoing experiments at the Sanford Underground Research Facility with the goal to characterize seismic fields in three dimensions are expected to deliver first data from an underground seismometer array in 2015 (see [89] for results from an initial stage of the experiment). While most people would argue that constructing GW detectors underground is always advantageous, it is still necessary to estimate how much is gained and whether the science case strongly profits from it. This is a complicated problem that needs to be answered as part of a site selection process.

 

More recently, high-precision gravity strainmeters have been considered as monitors of geophysical signals [83]. Analytical models have been calculated, which allow us to predict gravity transients from seismic sources such as earthquakes. It was suggested to implement gravity strainmeters in existing earthquake-early warning systems to increase warning times. It is also conceivable that an alternative method to estimate source parameters using gravity signals will improve our understanding of seismic sources. Potential applications must still be investigated in greater detail, but the study already demonstrates that the idea to use GW technology to realize new geophysical sensors seems feasible. As explained in [49], gravitational forces start to dominate the dynamics of seismic phenomena below about 1 mHz (which coincides approximately with a similar transition in atmospheric dynamics where gravity waves start to dominate over other forms of oscillations [164]). Seismic isolation would be ineffective below 1 mHz since the gravitational acceleration of a test mass produced by seismic displacement becomes comparable to the seismic acceleration itself. Therefore, we claim that 10 mHz is about the lowest frequency at which ground-based gravity strainmeters will ever be able to detect GWs, and consequently, modelling terrestrial gravity perturbations in these detectors can focus on frequencies above 10 mHz.

 

This article is divided into six main sections. Section 2 serves as an introduction to gravity measurements focussing on the response mechanisms and basic properties of gravity sensors. Section 3 describes models of gravity perturbations from ambient seismic fields. The results can be used to estimate noise spectra at the surface and underground. A subsection is devoted to the problem of noise estimation in low-frequency GW detectors, which differs from high-frequency estimates mostly in that gravity perturbations are strongly correlated between different test masses. In the low-frequency regime, the gravity noise is best described as gravity-gradient noise. Section 4 is devoted to time domain models of transient gravity perturbations from seismic point sources. The formalism is applied to point forces and shear dislocations. The latter allows us to estimate gravity perturbations from earthquakes. Atmospheric models of gravity perturbations are presented in Section 5. This includes gravity perturbations from atmospheric temperature fields, infrasound fields, shock waves, and acoustic noise from turbulence. The solution for shock waves is calculated in time domain using the methods of Section 4. A theoretical framework to calculate gravity perturbations from objects is given in Section 6. Since many different types of objects can be potential sources of gravity perturbations, the discussion focusses on the development of a general method instead of summarizing all of the calculations that have been done in the past. Finally, Section 7 discusses possible passive and active noise mitigation strategies. Due to the complexity of the problem, most of the section is devoted to active noise cancellation providing the required analysis tools and showing limitations of this technique. Site selection is the main topic under passive mitigation, and is discussed in the context of reducing environmental noise and criteria relevant to active noise cancellation. Each of these sections ends with a summary and a discussion of open problems. While this article is meant to be a review of the current state of the field, it also presents new analyses especially with respect to the impact of seismic scattering on gravity perturbations (Sections 3.3.2 and 3.3.3), active gravity noise cancellation (Section 7.1.3), and timedomain models of gravity perturbations from atmospheric and seismic point sources (Sections 4.1, 4.5, and 5.3).

 

Even though evident to experts, it is worth emphasizing that all calculations carried out in this article have a common starting point, namely Newton’s universal law of gravitation. It states that the attractive gravitational force equation M1 between two point masses m1, m2 is given by

 

equation M21

where G = 6.672 × 10−11 N m2/kg2 is the gravitational constant. Eq. (1) gives rise to many complex phenomena on Earth such as inner-core oscillations [156], atmospheric gravity waves [157], ocean waves [94, 177], and co-seismic gravity changes [122]. Due to its importance, we will honor the eponym by referring to gravity noise as Newtonian noise in the following. It is thereby clarified that the gravity noise models considered in this article are non-relativistic, and propagation effects of gravity changes are neglected. While there could be interesting scenarios where this approximation is not fully justified (e.g., whenever a gravity perturbation can be sensed by several sensors and differences in arrival times can be resolved), it certainly holds in any of the problems discussed in this article. We now invite the reader to enjoy the rest of the article, and hope that it proves to be useful.

 

Go to:

Gravity Measurements

In this section, we describe the relevant mechanisms by which a gravity sensor can couple to gravity perturbations, and give an overview of the most widely used measurement schemes: the (relative) gravimeter [53, 181], the gravity gradiometer [125], and the gravity strainmeter. The last category includes the large-scale GW detectors Virgo [6], LIGO [91], GEO600 [119], KAGRA [17], and a new generation of torsion-bar antennas currently under development [13]. Also atom interferometers can potentially be used as gravity strainmeters in the future [62]. Strictly speaking, none of the sensors only responds to a single field quantity (such as changes in gravity acceleration or gravity strain), but there is always a dominant response mechanism in each case, which justifies to give the sensor a specific name. A clear distinction between gravity gradiometers and gravity strainmeters has never been made to our knowledge. Therefore the sections on these two measurement principles will introduce a definition, and it is by no means the only possible one. Later on in this article, we almost exclusively discuss gravity models relevant to gravity strainmeters since the focus lies on gravity fluctuations above 10 mHz. Today, the sensitivity near 10 mHz of gravimeters towards gravity fluctuations is still competitive to or exceeds the sensitivity of gravity strainmeters, but this is likely going to change in the future so that we can expect strainmeters to become the technology of choice for gravity observations above 10 mHz [88]. The following sections provide further details on this statement. Space-borne gravity experiments such as GRACE [167] will not be included in this overview. The measurement principle of GRACE is similar to that of gravity strainmeters, but only very slow changes of Earth gravity field can be observed, and for this reason it is beyond the scope of this article.

 

The different response mechanisms to terrestrial gravity perturbations are summarized in Section 2.1. While we will identify the tidal forces acting on the test masses as dominant coupling mechanism, other couplings may well be relevant depending on the experiment. The Shapiro time delay will be discussed as the only relativistic effect. Higher-order relativistic effects are neglected. All other coupling mechanisms can be calculated using Newtonian theory including tidal forces, coupling in static non-uniform gravity fields, and coupling through ground displacement induced by gravity fluctuations. In Sections 2.2 to 2.4, the different measurement schemes are explained including a brief summary of the sensitivity limitations (choosing one of a few possible experimental realizations in each case). As mentioned before, we will mostly develop gravity models relevant to gravity strainmeters in the remainder of the article. Therefore, the detailed discussion of alternative gravimetry concepts mostly serves to highlight important differences between these concepts, and to develop a deeper understanding of the instruments and their role in gravity measurements.

 

Gravity response mechanisms

 

Gravity acceleration and tidal forces We will start with the simplest mechanism of all, the acceleration of a test mass in the gravity field. Instruments that measure the acceleration are called gravimeters. A test mass inside a gravimeter can be freely falling such as atom clouds [181] or, as suggested as possible future development, even macroscopic objects [72]. Typically though, test masses are supported mechanically or magnetically constraining motion in some of its degrees of freedom. A test mass suspended from strings responds to changes in the horizontal gravity acceleration. A test mass attached at the end of a cantilever with horizontal equilibrium position responds to changes in vertical gravity acceleration. The support fulfills two purposes. First, it counteracts the static gravitational force in a way that the test mass can respond to changes in the gravity field along a chosen degree of freedom. Second, it isolates the test mass from vibrations. Response to signals and isolation performance depend on frequency. If the support is modelled as a linear, harmonic oscillator, then the test mass response to gravity changes extends over all frequencies, but the response is strongly suppressed below the oscillators resonance frequency. The response function between the gravity perturbation δg(ω) and induced test mass acceleration δa(ω) assumes the form

equation M32

where we have introduced a viscous damping parameter γ, and ω0 is the resonance frequency. Well below resonance, the response is proportional to ω2, while it is constant well above resonance. Above resonance, the supported test mass responds like a freely falling mass, at least with respect to “soft” directions of the support. The test-mass response to vibrations δα(ω) of the support is given by

 

equation M43

This applies for example to horizontal vibrations of the suspension points of strings that hold a test mass, or to vertical vibrations of the clamps of a horizontal cantilever with attached test mass. Well above resonance, vibrations are suppressed by ω−2, while no vibration isolation is provided below resonance. The situation is somewhat more complicated in realistic models of the support especially due to internal modes of the mechanical system (see for example [76]), or due to coupling of degrees of freedom [121]. Large mechanical support structures can feature internal resonances at relatively low frequencies, which can interfere to some extent with the desired performance of the mechanical support [173]. While Eqs. (2) and (3) summarize the properties of isolation and response relevant for this paper, details of the readout method can fundamentally impact an instrument’s response to gravity fluctuations and its susceptibility to seismic noise, as explained in Sections 2.2 to 2.4.

 

Next, we discuss the response to tidal forces. In Newtonian theory, tidal forces cause a relative acceleration δg12(ω) between two freely falling test masses according to

 

equation M54

where equation M6 is the Fourier amplitude of the gravity potential. The last equation holds if the distance r12 between the test masses is sufficiently small, which also depends on the frequency. The term equation M7 is called gravity-gradient tensor. In Newtonian approximation, the second time integral of this tensor corresponds to gravity strain equation M8, which is discussed in more detail in Section 2.4. Its trace needs to vanish in empty space since the gravity potential fulfills the Poisson equation. Tidal forces produce the dominant signals in gravity gradiometers and gravity strainmeters, which measure the differential acceleration or associated relative displacement between two test masses (see Sections 2.3 and 2.4). If the test masses used for a tidal measurement are supported, then typically the supports are designed to be as similar as possible, so that the response in Eq. (2) holds for both test masses approximately with the same parameter values for the resonance frequencies (and to a lesser extent also for the damping). For the purpose of response calibration, it is less important to know the parameter values exactly if the signal is meant to be observed well above the resonance frequency where the response is approximately equal to 1 independent of the resonance frequency and damping (here, “well above” resonance also depends on the damping parameter, and in realistic models, the signal frequency also needs to be “well below” internal resonances of the mechanical support).

 

Shapiro time delay Another possible gravity response is through the Shapiro time delay [19]. This effect is not universally present in all gravity sensors, and depends on the readout mechanism. Today, the best sensitivities are achieved by reflecting laser beams from test masses in interferometric configurations. If the test mass is displaced by gravity fluctuations, then it imprints a phase shift onto the reflected laser, which can be observed in laser interferometers, or using phasemeters. We will give further details on this in Section 2.4. In Newtonian gravity, the acceleration of test masses is the only predicted response to gravity fluctuations. However, from general relativity we know that gravity also affects the propagation of light. The leading-order term is the Shapiro time delay, which produces a phase shift of the laser beam with respect to a laser propagating in flat space. It can be calculated from the weak-field spacetime metric (see chapter 18 in [124]):

equation M95

Here, c is the speed of light, ds is the so-called line element of a path in spacetime, and equation M10. Additionally, for this metric to hold, motion of particles in the source of the gravity potential responsible for changes of the gravity potential need to be much slower than the speed of light, and also stresses inside the source must be much smaller than its mass energy density. All conditions are fulfilled in the case of Earth gravity field. Light follows null geodesics with ds2 = 0. For the spacetime metric in Eq. (5), we can immediately write

 

equation M116

As we will find out, this equation can directly be used to calculate the time delay as an integral along a straight line in terms of the coordinates equation M12, but this is not immediately clear since light bends in a gravity field. So one may wonder if integration along the proper light path instead of a straight line yields additional significant corrections. The so-called geodesic equation must be used to calculate the path. It is a set of four differential equations, one for each coordinate t, equation M13 in terms of a parameter λ. The weak-field geodesic equation is obtained from the metric in Eq. (5):

 

equation M147

where we have made use of Eq. (6) and the slow-motion condition equation M15. The coordinates equation M16 are to be understood as functions of λ. Since the deviation of a straight path is due to a weak gravity potential, we can solve these equations by perturbation theory introducing expansions equation M17 and t = t(0) +t(1) + …. The superscript indicates the order in ψ/c2. The unperturbed path has the simple parametrization

 

equation M188

We have chosen integration constants such that unperturbed time t(0) and parameter λ can be used interchangeably (apart from a shift by t0). Inserting these expressions into the right-hand side of Eq. (7), we obtain

 

equation M199

As we can see, up to linear order in equation M20, the deviation equation M21 is in orthogonal direction to the unperturbed path equation M22, which means that the deviation can be neglected in the calculation of the time delay. After some transformations, it is possible to derive Eq. (6) from Eq. (9), and this time we find explicitly that the right-hand-side of the equation only depends on the unperturbed coordinates1. In other words, we can integrate the time delay along a straight line as defined in Eq. (8), and so the total phase integrated over a travel distance L is given by

 

equation M2310

In static gravity fields, the phase shift doubles if the light is sent back since not only the direction of integration changes, but also the sign of the expression substituted for dt/dλ.

 

Gravity induced ground motion As we will learn in Section 3, seismic fields produce gravity perturbations either through density fluctuations of the ground, or by displacing interfaces between two materials of different density. It is also well-known in seismology that seismic fields can be affected significantly by self-gravity. Self-gravity means that the gravity perturbation produced by a seismic field acts back on the seismic field. The effect is most significant at low frequency where gravity induced acceleration competes against acceleration from elastic forces. In seismology, low-frequency seismic fields are best described in terms of Earth’s normal modes [55]. Normal modes exist as toroidal modes and spheroidal modes. Spheroidal modes are influenced by self-gravity, toroidal modes are not. For example, predictions of frequencies and shapes of spheroidal modes based on Earth models such as PREM (Preliminary Reference Earth Model) [68] are inaccurate if self-gravity effects are excluded. What this practically means is that in addition to displacement amplitudes, gravity becomes a dynamical variable in the elastodynamic equations that determine the normal-mode properties. Therefore, seismic displacement and gravity perturbation cannot be separated in normal-mode formalism (although self-gravity can be neglected in calculations of spheroidal modes at sufficiently high frequency).

In certain situations, it is necessary or at least more intuitive to separate gravity from seismic fields. An exotic example is Earth’s response to GWs [67, 49, 47, 30, 48]. Another example is the seismic response to gravity perturbations produced by strong seismic events at large distance to the source as described in Section 4. It is more challenging to analyze this scenario using normal-mode formalism. The sum over all normal modes excited by the seismic event (each of which describing a global displacement field) must lead to destructive interference of seismic displacement at large distances (where seismic waves have not yet arrived), but not of the gravity amplitudes since gravity is immediately perturbed everywhere. It can be easier to first calculate the gravity perturbation from the seismic perturbation, and then to calculate the response of the seismic field to the gravity perturbation at larger distance. This method will be adopted in this section. Gravity fields will be represented as arbitrary force or tidal fields (detailed models are presented in later sections), and we simply calculate the response of the seismic field. Normal-mode formalism can be avoided only at sufficiently high frequencies where the curvature of Earth does not significantly influence the response (i.e., well above 10 mHz). In this section, we will model the ground as homogeneous half space, but also more complex geologies can in principle be assumed.

 

Gravity can be introduced in two ways into the elastodynamic equations, as a conservative force −∇ψ [146, 169], or as tidal strain The latter method was described first by Dyson to calculate Earth’s response to GWs [67]. The approach also works for Newtonian gravity, with the difference that the tidal field produced by a GW is necessarily a quadrupole field with only two degrees of freedom (polarizations), while tidal fields produced by terrestrial sources are less constrained. Certainly, GWs can only be fully described in the framework of general relativity, which means that their representation as a Newtonian tidal field cannot be used to explain all possible observations [124]. Nonetheless, important here is that Dyson’s method can be extended to Newtonian tidal fields. Without gravity, the elastodynamic equations for small seismic displacement can be written as

 

equation M2411

where equation M25 is the seismic displacement field, and equation M26 is the stress tensor [9]. In the absence of other forces, the stress is determined by the seismic field. In the case of a homogeneous and isotropic medium, the stress tensor for small seismic displacement can be written as

 

equation M2712

The quantity equation M28 is known as seismic strain tensor, and λ, μ are the Lamé constants (see Section 3.1). Its trace is equal to the divergence of the displacement field. Dyson introduced the tidal field from first principles using Lagrangian mechanics, but we can follow a simpler approach. Eq. (12) means that a stress field builds up in response to a seismic strain field, and the divergence of the stress field acts as a force producing seismic displacement. The same happens in response to a tidal field, which we represent as gravity strain equation M29. A strain field changes the distance between two freely falling test masses separated by equation M30 by equation M312. For sufficiently small distances L, the strain field can be substituted by the second time integral of the gravity-gradient tensor equation M32. If the masses are not freely falling, then the strain field acts as an additional force. The corresponding contribution to the material’s stress tensor can be written

 

equation M3313

Since we assume that the gravity field is produced by a distant source, the local contribution to gravity perturbations is neglected, which means that the gravity potential obeys the Laplace equation, equation M34. Calculating the divergence of the stress tensor according to Eq. (11), we find that the gravity term vanishes! This means that a homogeneous and isotropic medium does not respond to gravity strain fields. However, we have to be more careful here. Our goal is to calculate the response of a half-space to gravity strain. Even if the half-space is homogeneous, the Lamé constants change discontinuously across the surface. Hence, at the surface, the divergence of the stress tensor reads

 

equation M3514

In other words, tidal fields produce a force onto an elastic medium via gradients in the shear modulus (second Lamé constant). The gradient of the shear modulus can be written in terms of a Dirac delta function, equation M36, for a flat surface at z = 0 with unit normal vector equation M37. The response to gravity strain fields is obtained applying the boundary condition of vanishing surface traction, equation M38:

 

equation M3915

Once the seismic strain field is calculated, it can be used to obtain the seismic stress, which determines the displacement field equation M40 according to Eq. (11). In this way, one can for example calculate that a seismometer or gravimeter can observe GWs by monitoring surface displacement as was first calculated by Dyson [67].

 

Coupling in non-uniform, static gravity fields If the gravity field is static, but non-uniform, then displacement equation M41 of the test mass in this field due to a non-gravitational fluctuating force is associated with a changing gravity acceleration according to

equation M4216

We introduce a characteristic length λ, over which gravity acceleration varies significantly. Hence, we can rewrite the last equation in terms of the associated test-mass displacement ζ

 

equation M4317

where we have neglected directional dependence and numerical factors. The acceleration change from motion in static, inhomogeneous fields is generally more significant at low frequencies. Let us consider the specific case of a suspended test mass. It responds to fluctuations in horizontal gravity acceleration. The test mass follows the motion of the suspension point in vertical direction (i.e., no seismic isolation), while seismic noise in horizontal direction is suppressed according to Eq. (3). Accordingly, it is possible that the unsuppressed vertical (z-axis) seismic noise ξz(t) coupling into the horizontal (x-axis) motion of the test mass through the term ∂xgz = ∂zgx dominates over the gravity response term in Eq. (2). Due to additional coupling mechanisms between vertical and horizontal motion in real seismic-isolation systems, test masses especially in GW detectors are also isolated in vertical direction, but without achieving the same noise suppression as in horizontal direction. For example, the requirements on vertical test-mass displacement for Advanced LIGO are a factor 1000 less stringent than on the horizontal displacement [22]. Requirements can be set on the vertical isolation by estimating the coupling of vertical motion into horizontal motion, which needs to take the gravity-gradient coupling of Eq. (16) into account. Although, because of the frequency dependence, gravity-gradient effects are more significant in low-frequency detectors, such as the space-borne GW detector LISA [154].

 

Next, we calculate an estimate of gravity gradients in the vicinity of test masses in large-scale GW detectors, and see if the gravity-gradient coupling matters compared to mechanical vertical-to-horizontal coupling.

 

One contribution to gravity gradients will come from the vacuum chamber surrounding the test mass. We approximate the shape of the chamber as a hollow cylinder with open ends (open ends just to simplify the calculation). In our calculation, the test mass can be offset from the cylinder axis and be located at any distance to the cylinder ends (we refer to this coordinate as height). The gravity field can be expressed in terms of elliptic integrals, but the explicit solution is not of concern here. Instead, let us take a look at the results in Figure ​Figure1.1. Gravity gradients ∂zgx vanish if the test mass is located on the symmetry axis or at height L/2. There are also two additional ∂zgx = 0 contour lines starting at the symmetry axis at heights ∼ 0.24 and ∼0.76. Let us assume that the test mass is at height 0.3L, a distance 0.05L from the cylinder axis, the total mass of the cylinder is M = 5000 kg, and the cylinder height is L = 4 m. In this case, the gravity-gradient induced vertical-to-horizontal coupling factor at 20 Hz is

 

equation M4418

This means that gravity-gradient induced coupling is extremely weak, and lies well below estimates of mechanical coupling (of order 0.001 in Advanced LIGO3). Even though the vacuum chamber was modelled with a very simple shape, and additional asymmetries in the mass distribution around the test mass may increase gravity gradients, it still seems very unlikely that the coupling would be significant. As mentioned before, one certainly needs to pay more attention when calculating the coupling at lower frequencies. The best procedure is of course to have a 3D model of the near test-mass infrastructure available and to use it for a precise calculation of the gravity-gradient field.

 

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Figure 1

Gravity gradients inside hollow cylinder. The total height of the cylinder is L, and M is its total mass. The radius of the cylinder is 0.3L. The axes correspond to the distance of the test mass from the symmetry axis of the cylinder, and its height above one of the cylinders ends. The plot on the right is simply a zoom of the left plot into the intermediate heights.

Gravimeters

 

Gravimeters are instruments that measure the displacement of a test mass with respect to a non-inertial reference rigidly connected to the ground. The test mass is typically supported mechanically or magnetically (atom-interferometric gravimeters are an exception), which means that the test-mass response to gravity is altered with respect to a freely falling test mass. We will use Eq. (2) as a simplified response model. There are various possibilities to measure the displacement of a test mass. The most widespread displacement sensors are based on capacitive readout, as for example used in superconducting gravimeters (see Figure ​Figure22 and [96]). Sensitive displacement measurements are in principle also possible with optical readout systems; a method that is (necessarily) implemented in atom-interferometric gravimeters [137], and prototype seismometers [34] (we will explain the distinction between seismometers and gravimeters below). As will become clear in Section 2.4, optical readout is better suited for displacement measurements over long baselines, as required for the most sensitive gravity strain measurements, while the capacitive readout should be designed with the smallest possible distance between the test mass and the non-inertial reference [104].

 

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Figure 2

Sketch of a levitated sphere serving as test mass in a superconducting gravimeter. Dashed lines indicate magnetic field lines. Coils are used for levitation and precise positioning of the sphere. Image reproduced with permission from [96]; copyright by Elsevier.

Let us take a closer look at the basic measurement scheme of a superconducting gravimeter shown in Figure ​Figure2.2. The central part is formed by a spherical superconducting shell that is levitated by superconducting coils. Superconductivity provides stability of the measurement, and also avoids some forms of noise (see [96] for details). In this gravimeter design, the lower coil is responsible mostly to balance the mean gravitational force acting on the sphere, while the upper coil modifies the magnetic gradient such that a certain “spring constant” of the magnetic levitation is realized. In other words, the current in the upper coil determines the resonance frequency in Eq. (2).

 

Capacitor plates are distributed around the sphere. Whenever a force acts on the sphere, the small signal produced in the capacitive readout is used to immediately cancel this force by a feedback coil. In this way, the sphere is kept at a constant location with respect to the external frame. This illustrates a common concept in all gravimeters. The displacement sensors can only respond to relative displacement between a test mass and a surrounding structure. If small gravity fluctuations are to be measured, then it is not sufficient to realize low-noise readout systems, but also vibrations of the surrounding structure forming the reference frame must be as small as possible. In general, as we will further explore in the coming sections, gravity fluctuations are increasingly dominant with decreasing frequency. At about 1 mHz, gravity acceleration associated with fluctuating seismic fields become comparable to seismic acceleration, and also atmospheric gravity noise starts to be significant [53]. At higher frequencies, seismic acceleration is much stronger than typical gravity fluctuations, which means that the gravimeter effectively operates as a seismometer. In summary, at sufficiently low frequencies, the gravimeter senses gravity accelerations of the test mass with respect to a relatively quiet reference, while at higher frequencies, the gravimeter senses seismic accelerations of the reference with respect to a test mass subject to relatively small gravity fluctuations. In superconducting gravimeters, the third important contribution to the response is caused by vertical motion ξ(t) of a levitated sphere against a static gravity gradient (see Section 2.1.4). As explained above, feedback control suppresses relative motion between sphere and gravimeter frame, which causes the sphere to move as if attached to the frame or ground. In the presence of a static gravity gradient ∂zgz, the motion of the sphere against this gradient leads to a change in gravity, which alters the feedback force (and therefore the recorded signal). The full contribution from gravitational, δa(t), and seismic, equation M45, accelerations can therefore be written

 

equation M4619

It is easy to verify, using Eqs. (2) and (3), that the relative amplitude of gravity and seismic fluctuations from the first two terms is independent of the test-mass support. Therefore, vertical seismic displacement of the reference frame must be considered fundamental noise of gravimeters and can only be avoided by choosing a quiet measurement site. Obviously, Eq. (19) is based on a simplified support model. One of the important design goals of the mechanical support is to minimize additional noise due to non-linearities and cross-coupling. As is explained further in Section 2.3, it is also not possible to suppress seismic noise in gravimeters by subtracting the disturbance using data from a collocated seismometer. Doing so inevitably turns the gravimeter into a gravity gradiometer.

 

Gravimeters target signals that typically lie well below 1 mHz. Mechanical or magnetic supports of test masses have resonance frequencies at best slightly below 10 mHz along horizontal directions, and typically above 0.1 Hz in the vertical direction [23, 174]4. Well below resonance frequency, the response function can be approximated as equation M47. At first, it may look as if the gravimeter should not be sensitive to very low-frequency fluctuations since the response becomes very weak. However, the strength of gravity fluctuations also strongly increases with decreasing frequency, which compensates the small response. It is clear though that if the resonance frequency was sufficiently high, then the response would become so weak that the gravity signal would not stand out above other instrumental noise anymore. The test-mass support would be too stiff. The sensitivity of the gravimeter depends on the resonance frequency of the support and the intrinsic instrumental noise. With respect to seismic noise, the stiffness of the support has no influence as explained before (the test mass can also fall freely as in atom interferometers).

 

For superconducting gravimeters of the Global Geodynamics Project (GGP) [52], the median spectra are shown in Figure ​Figure3.3. Between 0.1 mHz and 1 mHz, atmospheric gravity perturbations typically dominate, while instrumental noise is the largest contribution between 1 mHz and 5 mHz [96]. The smallest signal amplitudes that have been measured by integrating long-duration signals is about 10−12 m/s2. A detailed study of noise in superconducting gravimeters over a larger frequency range can be found in [145]. Note that in some cases, it is not fit to categorize seismic and gravity fluctuations as noise and signal. For example, Earth’s spherical normal modes coherently excite seismic and gravity fluctuations, and the individual contributions in Eq. (19) have to be understood only to accurately translate data into normal-mode amplitudes [55].

 

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Figure 3

Median spectra of superconducting gravimeters of the GGP. Image reproduced with permission from [48]; copyright by APS.

Gravity gradiometers

 

It is not the purpose of this section to give a complete overview of the different gradiometer designs. Gradiometers find many practical applications, for example in navigation and resource exploration, often with the goal to measure static or slowly changing gravity gradients, which do not concern us here. For example, we will not discuss rotating gradiometers, and instead focus on gradiometers consisting of stationary test masses. While the former are ideally suited to measure static or slowly changing gravity gradients with high precision especially under noisy conditions, the latter design has advantages when measuring weak tidal fluctuations. In the following, we only refer to the stationary design. A gravity gradiometer measures the relative acceleration between two test masses each responding to fluctuations of the gravity field [102, 125]. The test masses have to be located close to each other so that the approximation in Eq. (4) holds. The proximity of the test masses is used here as the defining property of gradiometers. They are therefore a special type of gravity strainmeter (see Section 2.4), which denotes any type of instrument that measures relative gravitational acceleration (including the even more general concept of measuring space-time strain).

 

Gravity gradiometers can be realized in two versions. First, one can read out the position of two test masses with respect to the same rigid, non-inertial reference. The two channels, each of which can be considered a gravimeter, are subsequently subtracted. This scheme is for example realized in dual-sphere designs of superconducting gravity gradiometers [90] or in atom-interferometric gravity gradiometers [159].

 

It is schematically shown in Figure ​Figure4.4. Let us first consider the dual-sphere design of a superconducting gradiometer. If the reference is perfectly stiff, and if we assume as before that there are no cross-couplings between degrees of freedom and the response is linear, then the subtraction of the two gravity channels cancels all of the seismic noise, leaving only the instrumental noise and the differential gravity signal given by the second line of Eq. (4). Even in real setups, the reduction of seismic noise can be many orders of magnitude since the two spheres are close to each other, and the two readouts pick up (almost) the same seismic noise [125]. This does not mean though that gradiometers are necessarily more sensitive instruments to monitor gravity fields. A large part of the gravity signal (the common-mode part) is subtracted together with the seismic noise, and the challenge is now passed from finding a seismically quiet site to developing an instrument with lowest possible intrinsic noise.

 

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Figure 4

Basic scheme of a gravity gradiometer for measurements along the vertical direction. Two test masses are supported by horizontal cantilevers (superconducting magnets, …). Acceleration of both test masses is measured against the same non-inertial reference frame, which is connected to the ground. Each measurement constitutes one gravimeter. Subtraction of the two channels yields a gravity gradiometer.

The atom-interferometric gradiometer differs in some important details from the superconducting gradiometer. The test masses are realized by ultracold atom clouds, which are (nearly) freely falling provided that magnetic shielding of the atoms is sufficient, and interaction between atoms can be neglected. Interactions of a pair of atom clouds with a laser beam constitute the basic gravity gradiometer scheme. Even though the test masses are freely falling, the readout is not generally immune to seismic noise [80, 18]. The laser beam interacting with the atom clouds originates from a source subject to seismic disturbances, and interacts with optics that require seismic isolation. Schemes have been proposed that could lead to a large reduction of seismic noise [178, 77], but their effectiveness has not been tested in experiments yet. Since the differential position (or tidal) measurement is performed using a laser beam, the natural application of atom-interferometer technology is as gravity strainmeter (as explained before, laser beams are favorable for differential position measurements over long baselines). Nonetheless, the technology is currently insufficiently developed to realize large-baseline experiments, and we can therefore focus on its application in gradiometry. Let us take a closer look at the response of atom-interferometric gradiometers to seismic noise. In atom-interferometric detectors (excluding the new schemes proposed in [178, 77]), one can show that seismic acceleration δα(ω) of the optics or laser source limits the sensitivity of a tidal measurement according to

 

equation M4820

where L is the separation of the two atom clouds, and is the speed of light. It should be emphasized that the seismic noise remains, even if all optics and the laser source are all linked to the same infinitely stiff frame. In addition to this noise term, other coupling mechanisms may play a role, which can however be suppressed by engineering efforts. The noise-reduction factor ωL/c needs to be compared with the common-mode suppression of seismic noise in superconducting gravity gradiometers, which depends on the stiffness of the instrument frame, and on contamination from cross coupling of degrees-of-freedom. While the seismic noise in Eq. (20) is a fundamental noise contribution in (conventional) atom-interferometric gradiometers, the noise suppression in superconducting gradiometers depends more strongly on the engineering effort (at least, we venture to claim that common-mode suppression achieved in current instrument designs is well below what is fundamentally possible).

 

To conclude this section, we discuss in more detail the connection between gravity gradiometers and seismically (actively or passively) isolated gravimeters. As we have explained in Section 2.2, the sensitivity limitation of gravimeters by seismic noise is independent of the mechanical support of the test mass (assuming an ideal, linear support). The main purpose of the mechanical support is to maximize the response of the test mass to gravity fluctuations, and thereby increase the signal with respect to instrumental noise other than seismic noise. Here we will explain that even a seismic isolation of the gravimeter cannot overcome this noise limitation, at least not without fundamentally changing its response to gravity fluctuations. Let us first consider the case of a passively seismically isolated gravimeter. For example, we can imagine that the gravimeter is suspended from the tip of a strong horizontal cantilever. The system can be modelled as two oscillators in a chain, with a light test mass m supported by a heavy mass M representing the gravimeter (reference) frame, which is itself supported from a point rigidly connected to Earth. The two supports are modelled as harmonic oscillators. As before, we neglect cross coupling between degrees of freedom. Linearizing the response of the gravimeter frame and test mass for small accelerations, and further neglecting terms proportional to m/M, one finds the gravimeter response to gravity fluctuations:

 

equation M4921

Here, ω1, γ1 are the resonance frequency and damping of the gravimeter support, while ω2, γ2 are the resonance frequency and damping of the test-mass support. The response and isolation functions R(·), S(·) are defined in Eqs. (2) and (3). Remember that Eq. (21) is obtained as a differential measurement of test-mass acceleration versus acceleration of the reference frame. Therefore, δg1(ω) denotes the gravity fluctuation at the center-of-mass of the gravimeter frame, and δg2(ω) at the test mass. An infinitely stiff gravimeter suspension, ω1 → ∞, yields R(ω; ω1, γ1) = 0, and the response turns into the form of the non-isolated gravimeter. The seismic isolation is determined by

 

equation M5022

We can summarize the last two equations as follows. At frequencies well above ω1, the seismically isolated gravimeter responds like a gravity gradiometer, and seismic noise is strongly suppressed. The deviation from the pure gradiometer response ∼ δg2(ω) − δg1(ω) is determined by the same function S(ω; ω1, γ1) that describes the seismic isolation. In other words, if the gravity gradient was negligible, then we ended up with the conventional gravimeter response, with signals suppressed by the seismic isolation function. Well below ω1, the seismically isolated gravimeter responds like a conventional gravimeter without seismic-noise reduction. If the centers of the masses m (test mass) and M (reference frame) coincide, and therefore δg1(ω) = δg2(ω), then the response is again like a conventional gravimeter, but this time suppressed by the isolation function S(ω; ω1, γ1).

 

Let us compare the passively isolated gravimeter with an actively isolated gravimeter. In active isolation, the idea is to place the gravimeter on a stiff platform whose orientation can be controlled by actuators. Without actuation, the platform simply follows local surface motion. There are two ways to realize an active isolation. One way is to place a seismometer next to the platform onto the ground, and use its data to subtract ground motion from the platform. The actuators cancel the seismic forces. This scheme is called feed-forward noise cancellation. Feed-forward cancellation of gravity noise is discussed at length in Section 7.1, which provides details on its implementation and limitations. The second possibility is to place the seismometer together with the gravimeter onto the platform, and to suppress seismic noise in a feedback configuration [4, 2]. In the following, we discuss the feed-forward technique as an example since it is easier to analyze (for example, feedback control can be unstable [4]). As before, we focus on gravity and seismic fluctuations. The seismometer’s intrinsic noise plays an important role in active isolation limiting its performance, but we are only interested in the modification of the gravimeter’s response. Since there is no fundamental difference in how a seismometer and a gravimeter respond to seismic and gravity fluctuations, we know from Section 2.2 that the seismometer output is proportional to δg1(ω) − δα(ω), i.e., using a single test mass for acceleration measurements, seismic and gravity perturbations contribute in the same way. A transfer function needs to be multiplied to the acceleration signals, which accounts for the mechanical support and possibly also electronic circuits involved in the seismometer readout. To cancel the seismic noise of the platform that carries the gravimeter, the effect of all transfer functions needs to be reversed by a matched feed-forward filter. The output of the filter is then equal to δg1(ω) − δα(ω) and is added to the motion of the platform using actuators cancelling the seismic noise and adding the seismometer’s gravity signal. In this case, the seismometer’s gravity signal takes the place of the seismic noise in Eq. (3). The complete gravity response of the actively isolated gravimeter then reads

 

equation M5123

The response is identical to a gravity gradiometer, where ω2, γ2 are the resonance frequency and damping of the gravimeter’s test-mass support. In reality, instrumental noise of the seismometer will limit the isolation performance and introduce additional noise into Eq. (23). Nonetheless, Eqs. (21) and (23) show that any form of seismic isolation turns a gravimeter into a gravity gradiometer at frequencies where seismic isolation is effective. For the passive seismic isolation, this means that the gravimeter responds like a gradiometer at frequencies well above the resonance frequency ω1 of the gravimeter support, while it behaves like a conventional gravimeter below ω1. From these results it is clear that the design of seismic isolations and the gravity response can in general not be treated independently. As we will see in Section 2.4 though, tidal measurements can profit strongly from seismic isolation especially when common-mode suppression of seismic noise like in gradiometers is insufficient or completely absent.

 

Gravity strainmeters

 

Gravity strain is an unusual concept in gravimetry that stems from our modern understanding of gravity in the framework of general relativity. From an observational point of view, it is not much different from elastic strain. Fluctuating gravity strain causes a change in distance between two freely falling test masses, while seismic or elastic strain causes a change in distance between two test masses bolted to an elastic medium. It should be emphasized though that we cannot always use this analogy to understand observations of gravity strain [106]. Fundamentally, gravity strain corresponds to a perturbation of the metric that determines the geometrical properties of spacetime [124]. We will briefly discuss GWs, before returning to a Newtonian description of gravity strain.

 

Gravitational waves are weak perturbations of spacetime propagating at the speed of light. Freely falling test masses change their distance in the field of a GW. When the length of the GW is much larger than the separation between the test masses, it is possible to interpret this change as if caused by a Newtonian force. We call this the long-wavelength regime. Since we are interested in the low-frequency response of gravity strainmeters throughout this article (i.e., frequencies well below 100 Hz), this condition is always fulfilled for Earth-bound experiments. The effect of a gravity-strain field equation M52 on a pair of test masses can then be represented as an equivalent Newtonian tidal field

 

equation M5324

Here, equation M54 is the relative acceleration between two freely falling test masses, L is the distance between them, and equation M55 is the unit vector pointing from one to the other test mass, and equation M56 its transpose. As can be seen, the gravity-strain field is represented by a 3 × 3 tensor. It contains the space-components of a 4-dimensional metric perturbation of spacetime, and determines all properties of GWs5. Note that the strain amplitude h in Eq. (24) needs to be multiplied by 2 to obtain the corresponding amplitude of the metric perturbation (e.g., the GW amplitude). Throughout this article, we define gravity strain as h = ΔL/L, while the effect of a GW with amplitude aGW on the separation of two test mass is determined by aGW = 2ΔL/L.

 

The strain field of a GW takes the form of a quadrupole oscillation with two possible polarizations commonly denoted × (cross)-polarization and +(plus)-polarization. The arrows in Figure ​Figure55 indicate the lines of the equivalent tidal field of Eq. (24).

 

An external file that holds a picture, illustration, etc.

Object name is 41114_2016_3_Fig5.jpg

Figure 5

Polarizations of a gravitational wave.

Consequently, to (directly) observe GWs, one can follow two possible schemes: (1) the conventional method, which is a measurement of the relative displacement of suspended test masses typically carried out along two perpendicular baselines (arms); and (2) measurement of the relative rotation between two suspended bars. Figure ​Figure66 illustrates the two cases. In either case, the response of a gravity strainmeter is obtained by projecting the gravity strain tensor onto a combination of two unit vectors, equation M57 and equation M58, that characterize the orientation of the detector, such as the directions of two bars in a rotational gravity strain meter, or of two arms of a conventional gravity strain meter. This requires us to define two different gravity strain projections. The projection for the rotational strain measurement is given by

 

equation M5925

where the subscript × indicates that the detector responds to the ×-polarization assuming that the x, y-axes (see Figure ​Figure5)5) are oriented along two perpendicular bars. The vectors equation M60 and equation M61 are rotated counter-clockwise by 90° with respect to equation M62 and equation M63. In the case of perpendicular bars equation M64 and equation M65. The corresponding projection for the conventional gravity strain meter reads

 

equation M6626

The subscript + indicates that the detector responds to the +-polarization provided that the x, y-axes are oriented along two perpendicular baselines (arms) of the detector. The two schemes are shown in Figure ​Figure6.6. The most sensitive GW detectors are based on the conventional method, and distance between test masses is measured by means of laser interferometry. The LIGO and Virgo detectors have achieved strain sensitivities of better than 10−22 Hz−1/2 between about 50 Hz and 1000 Hz in past science runs and are currently being commissioned in their advanced configurations [91, 7]. The rotational scheme is realized in torsion-bar antennas, which are considered as possible technology for sub-Hz GW detection [155, 69]. However, with achieved strain sensitivity of about 10−8 Hz−1/2 near 0.1 Hz, the torsion-bar detectors are far from the sensitivity we expect to be necessary for GW detection [88].

 

An external file that holds a picture, illustration, etc.

Object name is 41114_2016_3_Fig6.jpg

Figure 6

Sketches of the relative rotational and displacement measurement schemes.

Let us now return to the discussion of the previous sections on the role of seismic isolation and its impact on gravity response. Gravity strainmeters profit from seismic isolation more than gravimeters or gravity gradiometers. We have shown in Section 2.2 that seismically isolated gravimeters are effectively gravity gradiometers. So in this case, seismic isolation changes the response of the instrument in a fundamental way, and it does not make sense to talk of seismically isolated gravimeters. Seismic isolation could in principle be beneficial for gravity gradiometers (i.e., the acceleration of two test masses is measured with respect to a common rigid, seismically isolated reference frame), but the common-mode rejection of seismic noise (and gravity signals) due to the differential readout is typically so high that other instrumental noise becomes dominant. So it is possible that some gradiometers would profit from seismic isolation, but it is not generally true. Let us now consider the case of a gravity strainmeter. As explained in Section 2.3, we distinguish gradiometers and strainmeters by the distance of their test masses. For example, the distance of the LIGO or Virgo test masses is 4 km and 3 km respectively. Seismic noise and terrestrial gravity fluctuations are insignificantly correlated between the two test masses within the detectors’ most sensitive frequency band (above 10 Hz). Therefore, the approximation in Eq. (4) does not apply. Certainly, the distinction between gravity gradiometers and strainmeters remains somewhat arbitrary since at any frequency the approximation in Eq. (4) can hold for one type of gravity fluctuation, while it does not hold for another. Let us adopt a more practical definition at this point. Whenever the design of the instrument places the test masses as distant as possible from each other given current technology, then we call such an instrument strainmeter. In the following, we will discuss seismic isolation and gravity response for three strainmeter designs, the laser-interferometric, atom-interferometric, and superconducting strainmeters. It should be emphasized that the atom-interferometric and superconducting concepts are still in the beginning of their development and have not been realized yet with scientifically interesting sensitivities.

 

Laser-interferometric strainmeters The most sensitive gravity strainmeters, namely the large-scale GW detectors, use laser interferometry to read out the relative displacement between mirror pairs forming the test masses. Each test mass in these detectors is suspended from a seismically isolated platform, with the suspension itself providing additional seismic isolation. Section 2.1.1 introduced a simplified response and isolation model based on a harmonic oscillator characterized by a resonance frequency ω0 and viscous damping γ6. In a multi-stage isolation and suspension system as realized in GW detectors (see for example [37, 121]), coupling between multiple oscillators cannot be neglected, and is fundamental to the seismic isolation performance, but the basic features can still be explained with the simplified isolation and response model of Eqs. (2) and (3). The signal output of the interferometer is proportional to the relative displacement between test masses. Since seismic noise is approximately uncorrelated between two distant test masses, the differential measurement itself cannot reject seismic noise as in gravity gradiometers. Without seismic isolation, the dominant signal would be seismic strain, i.e., the distance change between test masses due to elastic deformation of the ground, with a value of about 10−15 Hz−1/2 at 50 Hz (assuming kilometer-scale arm lengths). At the same time, without seismically isolated test masses, the gravity signal can only come from the ground response to gravity fluctuations as described in Section 2.1.3, and from the Shapiro time delay as described in Section 2.1.2.

 

www.ncbi.nlm.nih.gov/pmc/articles/PMC5256008/

Caption: Scanning electron micrograph of a human T lymphocyte (also called a T cell) from the immune system of a healthy donor.

 

Image credit: NIAID (National Institute of Allergy and Infectious Diseases)

 

From the International Space Station Research feature:

 

NASA and the National Institute on Aging, part of the National Institutes of Health, have teamed up to support research aboard the International Space Station that may one day advance medical care and quality of life for all humanity. T-Cell Activation in Aging is the first study to launch into space that is funded by the Biomedical Research on the International Space Station National Institutes of Health initiative.

 

It is difficult to study the genetic and molecular changes associated with aging-related immune suppression because the condition develops over decades, and the elderly often have illnesses that can complicate research studies. However, changes in the immune system—including T-cell behavior—quickly occur in space.

 

“One of our goals for this study is to use microgravity as a novel model system of aging to investigate the molecular mechanisms of immune suppression commonly seen in the elderly population,” said Millie Hughes-Fulford, former NASA astronaut, principal investigator for the study and researcher at the University of California, San Francisco, Northern California Institute for Research and Education and the San Francisco Veterans Affairs Medical Center. “Ultimately, this could lead us to new treatment strategies for immune system dysfunction.”

 

Read full article:

www.nasa.gov/mission_pages/station/research/news/T_Cell/

 

More about space station research:

www.nasa.gov/mission_pages/station/research/index.html

 

just watching, and waiting,

outside my sequestered door. As the oldest in the house... for whom the bell tolls... I prefer the plaintive coos of the nesting owls in the neighboring tree.

 

Once I accepted the inevitability of exposure, I focused on resistance: boosting my immune system and antivirals. I’ll share what I take daily, and if anyone is aware of any reason to *not* take these in the context of coronavirus, please let me know and I’ll update. I have not had a sick day for decades, and perhaps this helped, but remember that my personal journey is not prescriptive and that none of these have been properly studied to reach any conclusions on efficacy, yet:

 

1) Vitamin D (+ K2 for better absorption): “Studies have indicated that there is a high prevalence of vitamin D deficiency worldwide. Vitamin D deficiency may affect the immune system as vitamin D plays an immunomodulation role, enhancing innate immunity by up-regulating the expression and secretion of antimicrobial peptides, which boosts mucosal defenses. Furthermore, recent meta-analyses have reported a protective effect of vitamin D supplementation on respiratory tract infections” — WHO and an apparently biased site, but some links: Vitamin D Wiki

 

2) Magical mushroom powder of Shitake + Maitake: “We found significant stimulation of defense reaction. In all cases, the most active was the Maitake-Shiitake combination” — NIH

 

3) Coconut oil: “Several in vitro, animal, and human studies support the potential of coconut oil, lauric acid and its derivatives as effective and safe agents against a virus like nCoV-2019. Mechanistic studies on other viruses show that at least three mechanisms may be operating. Given the safety and broad availability of virgin coconut oil (VCO), we recommend that VCO be considered as a general prophylactic against viral and microbial infection.” — Ateneo University

 

4) Zinc, short term use: “In this study we demonstrate that the combination of Zn(2+) and PT at low concentrations (2 µM Zn(2+) and 2 µM PT) inhibits the replication of SARS-coronavirus (SARS-CoV)” — Researchgate And some warnings about prolonged use: Oregon State

 

5) Oregano oil capsules: “Mexican oregano oil and its main component, carvacrol, are able to inhibit different human and animal viruses in vitro.” — NIH

And then found to be helpful with other viruses, like norovirus and herpes: “This study provides novel findings on the antiviral properties of oregano oil” — sfamjournals

 

6) Vitamin C: “2019-nCoV infected pneumonia, namely severe acute respiratory infection (SARI) has caused global concern and emergency. We hypothesize that Vitamin C infusion can help improve the prognosis of patients with SARI. Therefore, it is necessary to study the clinical efficacy” — Clinicaltrials

 

These are all inexpensive on Amazon, but if you want an even stronger placebo effect, find the most expensive version, as that is proven to work better :) ScienceDaily

 

7) Update: I have added Quercetin. Its impact on Covid-19 has not yet been properly researched, but the basic mechanism could be similar to Chloroquine, and is an over-the-counter supplement even if you don’t have symptoms. Best with Zinc. From molecular simulation studies: "Liu et al. (2020) successfully crystallised the COVID-19 main protease (Mpro), which is a potential drug target. Quercetin... and curcumin [among others] appeared to have the best potential to act as COVID-19 Mpro inhibitors."

 

8) I also take NMN + TMG and have been discussing possible downstream NAD+ / sirtuin effects on COVID-19 with David Sinclair of Harvard Medical School. As with all of these, nothing is proven; it's just a fascinating hypothesis. The observed age effect on mortality is stark — the younger a person is, across the spectrum, the lower the death rate and hospitalization rate. Looking to NAD+ depletion as we age, and exacerbated by inflammation, perhaps it's ultimately an energy crisis and a loss of NAD + ATP that does us in.

 

Snips from his recent book Lifespan:

“NAD boosts the activity of all seven sirtuins. And because NAD is used by over 500 different enzymes, without any NAD, we’d be dead in 30 seconds. NAD acts as a fuel for sirtuins. NAD levels decrease with age throughout the body. Human studies with NAD boosters (NMN and NR) are ongoing. So far, there has been no toxicity, not even a hint of it.” (p.134)

 

Also: "Most antiviral drugs target specific viral proteins. Consequently, they often work for only one virus, and their efficacy can be compromised by the rapid evolution of resistant variants. There is a need for the identification of host proteins with broad-spectrum antiviral functions, which provide effective targets for therapeutic treatments that limit the evolution of viral resistance. Here, we report that sirtuins present such an opportunity for the development of broad-spectrum antiviral treatments, since our findings highlight these enzymes as ancient defense factors that protect against a variety of viral pathogens." — Researchgate

 

Sinclair added trimethylglycine (TMG) in a recent podcast. He also mentions not to take NMN or NR at night as they interfere with sleep.

 

H/T Nova Spivack for the corona-relevant links. He is maintaining a more complete list here.

 

“Ah, distinctly I remember

it was in the bleak December

And each separate dying ember

wrought its ghost upon the floor.

Much I marvelled this ungainly fowl

to hear discourse so plainly,

Though its answer little meaning—

little relevancy bore

For we cannot help agreeing

that no living human being

Ever yet was blessed with seeing

bird above his chamber door

What this grim, ungainly, ghastly, gaunt,

and ominous bird of yore

Meant in croaking ‘Nevermore.’”

— Edgar Allan Poe

You can see more photos at my Facebook page.

Zombies:

Basic undead that move slowly and die fairly easy. Most of them die from rotting too much or falling over. They can be killed with basically anything.

 

Red Zombies:

Zombies that are covered in red ooze, can run faster, jump higher, and rot slower. A lot slower. The ooze can be washed off the zombie if it is sprayed with water. They can only be found in dry warm places such as deserts. Symptoms of the ooze coming into contact with a human are: rashes, weakness, and the immune system being shut down. They can be killed with sturdy melee weapons and most firearms.

 

Tar Zombies:

Zombies that are covered in a thick, tar-like substance. They can swim fast and have feet that almost seem webbed. They are only in hot humid places such swamps.

 

Crushers:

A monster that is in-between being human and zombie. They have the capacity of thinking, unlike zombies. Crushers use their huge arms to crush and rip apart their prey. They also have the ability to charge and ram into walls with ease. They can be killed with sharp spears, or high caliber weapons. THESE ARE NOT ZOMBIES, THEY ARE STILL LIVING!

 

Zombified Crusher:

A very stupid and slow version of a Crusher. If a crusher is killed by zombies, it becomes a this. They can be killed the same way as Crusher.

 

Camouflaged Zombies:

Four-armed zombies that blend into their surroundings. They usually live in trees and jump down on their prey. They can sprint for a short time, but after approximately 50 feet, the give up. They can be killed with sharp melee weapons and medium to high caliber firearms.

 

Stalker Zombies:

Zombies that can run really fast and sneak around quietly. They usually are loners. They can be killed with most firearms. (melee is a bery bad idea for these guys)

 

Brute Zombies:

Giant, fat, and ugly. They spew out vomit that turns humans into zombies very quickly. They take longer to rot than all the other zombies. They can be killed with long sharp melee weapons, and high caliber firearms.

 

Spitter Zombies:

Spitters are zombies that have the ability to puke vomit that infects its victim. It takes about a minute for one to succumb to the effect of the infected vomit. Spitters also have warts and boils that can burst with more vomit like substance. Spitters are also extremely fast and agile. It is recommended that you use medium caliber firearms to kill them.

 

Mauler Zombies:

These zombies have larger fists and feet, and can punch with great force. They have very small heads, and rot just as fast as a basic zombie.They do not last long by themselves due to their weak heads and slow movement. They have slow moving packs and attack anything that moves. You can use just about and weapon to smash their tiny little heads in.

 

Banshees:

Banshees are mutated zombies that often go into the female gene. Banshees have the ability to alert any other zombies to a target. After screaming, they will start sprinting toward you and will not stop until you or it is dead. It is very rare for a male to become a Banshee. A Banshee decays slower, but can be killed with pretty much everything. Even though they are very easy to kill, they alert other zombies that are in a 1 mile radius.

 

Crazies:

Insane people that have not been mutated at all. They are found mostly in the mid west surrounding Texas since that is where the nuclear bomb was dropped. They become more insane the closer you get to the drop point of the nuke. Some are less insane such as the Hooded Warrior's Gas Empire. He has made a truce with Fort Ducced, thus becoming our ally. He supplies Fort Ducced with gasoline, diesel, and other liquids.

 

Donald Trump opened a Pandora’s Box when he and the Republican Party politicized the coronavirus. When he called it the “Kung Flu” and the “Wuhan Virus,” racists attacked Asian-Americans. As a new virus, we have no natural immunity. But Trump refused to heed the warnings to social distance and wear masks, playing down the severity of the disease for political gain. Instead, he promoted fake cures and dismissed science experts. His acolytes followed suit. Rather than follow the science, right-wing charlatans continue to tout fake COVID cures. Only recently has Trump promoted vaccines and boosters (in part to separate himself from potential presidential rivals like Ron DeSantis). Other GOP lawmakers have privately protected themselves while publicly refusing to convey the importance of being immunized. And over 800,000 Americans have died.

 

People reacted with anger and pseudo-science theories when President Biden first appealed to Americans to “get the shot.” Incentives encouraged vaccinations. While these motivated some, it was much less than needed to reach herd immunity. With vaccination rates lagging, President Biden forced the issue with mandates for businesses with over 100 employees. And now conservatives on the Supreme Court have overruled those.

 

Adam Galinsky, a professor of leadership and ethics at Columbia Business School, recently wrote about the “psychology of regret” and its effect on vaccine hesitancy. “Alongside skepticism of institutions and experts, exposure to misinformation, and other often-cited reasons for resisting vaccines sits a clear emotional explanation: Many people are afraid that they’ll make a bad decision.” Fear can cause people to hesitate, no matter what the incentives might be. It may not seem rational, but many put more weight on the negative ramifications of their decisions than on any potential positive outcomes. They assign their actions greater importance than the consequences of not acting.

 

Ironically, this sense of regret explains why mandates have been so successful. When Biden first announced these mandates, the largest police union in New York City went to court to block them. They said they would lose thousands of officers who would quit rather than get inoculated. In reality, only three dozen officers ended up refusing. United Airlines instituted its mandate, and 99% of its workforce is vaccinated. This week they reported no deaths due to COVID. Mandates take the decision-making out of the individual’s hands. With the fear of making a wrong decision eliminated, most get vaccinated.

 

One of the most inane and insensitive protests over these requirements comes from those who show their opposition by wearing yellow Stars of David. Nazis required Jews to wear these stars with the word “Jude” at all times. Today’s protesters liken vaccine mandates to the persecution of Jews during World War II. They equate vaccination requirements with being sent to the gas chamber. At least, they say, it’s a slippery slope. They wear these stars as badges of resistance. However, Nazis forced Jews to wear them as signs of exclusion and disdain, signifying they were less than human. This false equivalent insults all Jews and their families who suffered during the Holocaust.

 

In June 2021, Jim Walsh, a Republican Washington State Representative, posted a video on Facebook showing him speaking to a group of conservatives while wearing the star. Posting on the social media platform, he said, “It’s an echo from history. In the current context, we’re all Jews.” We’re all Jews? During the Charlottesville protests, neo-Nazi’s chanted, “Jews will not replace us.” Now people are using the symbols of our annihilation to protest vaccine mandates. We’re tired of being used as scapegoats by neo-Nazis and examples of persecution by anti-vaxxers.

 

On November 14, 2021, anti-mandate protesters displayed the swastika and the yellow star in front of the offices of New York State Assemblyman Jeffrey Dinowitz, who is Jewish. Dinowitz has been a vigorous proponent of mandates. The crowd gathered to protest Dinowitz’s bill, requiring all students be immunized against COVID in order to attend school. Republican gubernatorial candidate, Rob Astorino, organized the rally. Assemblyman Dinowitz stated, “People are free to express their opinions on vaccine policy and on any issue, but I draw the line at swastikas. [T]o stand next to swastikas and yellow Stars of David outside of a Jewish legislator’s office shows a lack of integrity at best and an embrace of right-wing extremism at worst.”

 

In a hearing by the Kansas Special Committee on Government Overreach and the Impact of COVID-19 Mandates, former Kansas City, Kansas mayoral candidate Daran Duffy, explained why he and his family were wearing these stars. “The reason I’m wearing the star is not to be offensive, but it’s to remember, and for everybody else to call to remembrance World War II. The Jewish people were forced to wear a yellow star to identify them as Jews. And they were ushered off to the death camps in accordance with that. There were medical tests; there were experimentations done on human people. And while this hasn’t reached that deprivation, we are definitely moving in that direction.” Despite his sincerity, he is oblivious to the insensitivity of his protest.

 

And, just this week, Ohio Republican Congressman Warren Davidson likened vaccine mandates to Nazi atrocities by tweeting a photo of a Nazi Gesuntheitspaß (health passport) with the text, “It’s been done before. #DoNotComply” He went on to say, “Let’s recall that the Nazis dehumanized Jewish people before segregating them, segregated them before imprisoning them, imprisoned them before enslaving them, and enslaved them before massacring them.”

 

People receiving COVID shots are not part of an experiment. The actions of Nazi doctor Josef Mengele, who conducted sadistic medical procedures on Auschwitz children, are a far cry from the science behind these vaccines. For over two decades, researchers have been studying mRNA, the foundation of both the Pfizer and Moderna vaccines. Scientists conducted vigorous trials involving thousands of volunteers before their release. No one forced people to enroll in these trials. It was an altruistic choice meant to help others.

 

Mandates do not force people to get the vaccine. They have a choice. Yes, it’s a serious one. Their lives and their livelihoods may depend on what choice they make. And there are serious consequences for refusal, like losing one’s job. Without the vaccine, they may suffer a horrible death or lifelong after-effects. Even if you survive on a ventilator in the ICU, your life may never be the same. The coronavirus is and will continue to be a public health hazard.

 

Our personal decisions affect the people around us. Children and the immunocompromised are at risk. Many of these “hesitants” are ardent supporters of “American Exceptionalism,” believing that God has bestowed special blessings on our country and its people. But there is nothing exceptional about this selfishness.

 

The exploitation of the Star of David is part of the conflict over racial identity politics. Many Whites are afraid of being marginalized. And the GOP creates false wedge issues that stoke this fear as a way of igniting voters’ outrage. They’ve been employing this tactic for decades. So why is everyone outraged? Because the GOP wants us to be outraged. Because their hold on power depends on it.

 

Since this pandemic began, we have lived in a world without reason. American society has devolved into a culture where many equate vaccine mandates with Nazi atrocities. Critical thinking is often missing. Jewish identity is just one tangent of racial injustice. White racists often invoke Jew’s supposed political and financial power for their hatred. We can often pass for “white-white.” But we’re really “off-white.” When White racial fears abound, Jews are targeted.

 

Fear of losing control fuels opposition to vaccine mandates. But anti-vaxxers are not innocent victims of a frightening mob with an irrational agenda. COVID is a dire public health issue. And resistance to vaccines, mandates, and fear of make-believe persecution does not make them martyrs.

 

One may object to mandates, but don’t use symbols of real suffering to do so. Signs of our persecution are not yours to appropriate whenever you see fit. It feigns solidarity with Jews. But, in reality, these protesters are using us. Until you see your family marched off to the death camps, never to see them again, stop using the Star of David to compare your fears and outrage to the extermination of European Jewry. You don’t know what real suffering is. Stop living your lives as if you do.

  

Feel free to pass this poster on. It's free to download here (click on the down arrow just to the lower right of the image).

 

See the rest of the posters from the Chamomile Tea Party! Digital high res downloads are free here (click the down arrow on the lower right side of the image). Other options are available. And join our Facebook group.

 

Follow the history of our country's political intransigence from 2010-2020 through a seven-part exhibit of these posters on Google Arts & Culture.

So yesterday not one, but two of my memes got reviewed on J2GOSRS, the firsrt meme on the left he gave a 6/10, better than expected (despite the fact he got spooked), the second one on the right he didn't rate because he hasn't played a Lego game, but he at least featured it. If I keep this up I might get some more memes featured on more meme shows.

Your local councils bright idea on how to stone damage your car or motorcycle....with immunity!!!!!!

The mind is never immune to “alien thoughts,” and there is no easy way of weeding them out. A Hasidic rabbi, asked by his disciples in the last hours of his life whom they should choose as their master after his passing away, said: “If someone should give you advice on how to eradicate alien intentions, know he is not your master.

-Abraham Joshua Heschel and the Sources of Wonder

by Michael Marmur

 

It is one thing to race or be driven by the vicissitudes that menace life, and another thing to stand still and embrace the presence of an eternal moment

--Abraham Joshua Heschel and the Sources of Wonder

by Michael Marmur

 

 

Das Immunsystem ist das körpereigene, individuelle Abwehrsystem gegen schädlichen Krankheitserregner - zum Beispiel Bakterien, Parasiten, Pilze, Protozoen (Einzeller) und Viren.

 

The immune system is the body's own, individual defense system against harmful pathogens - for example, bacteria, parasites, fungi, protozoa (unicellular organisms) and viruses.

Benjamin Jesty was my 5 times great grand uncle and a man who failed to obtain his rightful place in history.

 

In 1774 smallpox arrived in Dorset. Benjamin Jesty, a farmer from Yetminster, had noticed that milkmaids who contracted the much lesser disease of cowpox through handling cows udders did not subsequently become infected with smallpox. He took the decision to vaccinate his wife Elizabeth and their two sons with cowpox material gathered from a nearby farm, thereby giving them immunity from the deadly disease of smallpox. All this happened 22 years before Edward Jenner announced he had discovered the vaccination but despite the gap in time it was Jenner that received the credit and not Benjamin.

 

It has been estimated that some 400,000 Europeans died from smallpox annually in the closing years of the 18th century. In 1979 the World Health Organization confirmed that various programmes of vaccination meant that naturally occurring smallpox had been eradicated throughout the world. To this day it is the only known deadly disease to man to be completely conquered by mankind and it started in a small village in Dorset.

 

Coronavirus disease 2019 (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).[8] The disease was first identified in December 2019 in Wuhan, the capital of China's Hubei province, and has since spread globally, resulting in the ongoing 2019–20 coronavirus pandemic.[9][10] As of 26 April 2020, more than 2.89 million cases have been reported across 185 countries and territories, resulting in more than 203,000 deaths. More than 822,000 people have recovered.[7]

 

Common symptoms include fever, cough, fatigue, shortness of breath and loss of smell.[5][11][12] While the majority of cases result in mild symptoms, some progress to viral pneumonia, multi-organ failure, or cytokine storm.[13][9][14] More concerning symptoms include difficulty breathing, persistent chest pain, confusion, difficulty waking, and bluish skin.[5] The time from exposure to onset of symptoms is typically around five days but may range from two to fourteen days.[5][15]

 

The virus is primarily spread between people during close contact,[a] often via small droplets produced by coughing,[b] sneezing, or talking.[6][16][18] The droplets usually fall to the ground or onto surfaces rather than remaining in the air over long distances.[6][19][20] People may also become infected by touching a contaminated surface and then touching their face.[6][16] In experimental settings, the virus may survive on surfaces for up to 72 hours.[21][22][23] It is most contagious during the first three days after the onset of symptoms, although spread may be possible before symptoms appear and in later stages of the disease.[24] The standard method of diagnosis is by real-time reverse transcription polymerase chain reaction (rRT-PCR) from a nasopharyngeal swab.[25] Chest CT imaging may also be helpful for diagnosis in individuals where there is a high suspicion of infection based on symptoms and risk factors; however, guidelines do not recommend using it for routine screening.[26][27]

 

Recommended measures to prevent infection include frequent hand washing, maintaining physical distance from others (especially from those with symptoms), covering coughs, and keeping unwashed hands away from the face.[28][29] In addition, the use of a face covering is recommended for those who suspect they have the virus and their caregivers.[30][31] Recommendations for face covering use by the general public vary, with some authorities recommending against their use, some recommending their use, and others requiring their use.[32][31][33] Currently, there is not enough evidence for or against the use of masks (medical or other) in healthy individuals in the wider community.[6] Also masks purchased by the public may impact availability for health care providers.

 

Currently, there is no vaccine or specific antiviral treatment for COVID-19.[6] Management involves the treatment of symptoms, supportive care, isolation, and experimental measures.[34] The World Health Organization (WHO) declared the 2019–20 coronavirus outbreak a Public Health Emergency of International Concern (PHEIC)[35][36] on 30 January 2020 and a pandemic on 11 March 2020.[10] Local transmission of the disease has occurred in most countries across all six WHO regions.[37]

 

File:En.Wikipedia-VideoWiki-Coronavirus disease 2019.webm

Video summary (script)

 

Contents

1Signs and symptoms

2Cause

2.1Transmission

2.2Virology

3Pathophysiology

3.1Immunopathology

4Diagnosis

4.1Pathology

5Prevention

6Management

6.1Medications

6.2Protective equipment

6.3Mechanical ventilation

6.4Acute respiratory distress syndrome

6.5Experimental treatment

6.6Information technology

6.7Psychological support

7Prognosis

7.1Reinfection

8History

9Epidemiology

9.1Infection fatality rate

9.2Sex differences

10Society and culture

10.1Name

10.2Misinformation

10.3Protests

11Other animals

12Research

12.1Vaccine

12.2Medications

12.3Anti-cytokine storm

12.4Passive antibodies

13See also

14Notes

15References

16External links

16.1Health agencies

16.2Directories

16.3Medical journals

Signs and symptoms

Symptom[4]Range

Fever83–99%

Cough59–82%

Loss of Appetite40–84%

Fatigue44–70%

Shortness of breath31–40%

Coughing up sputum28–33%

Loss of smell15[38] to 30%[12][39]

Muscle aches and pains11–35%

Fever is the most common symptom, although some older people and those with other health problems experience fever later in the disease.[4][40] In one study, 44% of people had fever when they presented to the hospital, while 89% went on to develop fever at some point during their hospitalization.[4][41]

 

Other common symptoms include cough, loss of appetite, fatigue, shortness of breath, sputum production, and muscle and joint pains.[4][5][42][43] Symptoms such as nausea, vomiting and diarrhoea have been observed in varying percentages.[44][45][46] Less common symptoms include sneezing, runny nose, or sore throat.[47]

 

More serious symptoms include difficulty breathing, persistent chest pain or pressure, confusion, difficulty waking, and bluish face or lips. Immediate medical attention is advised if these symptoms are present.[5][48]

 

In some, the disease may progress to pneumonia, multi-organ failure, and death.[9][14] In those who develop severe symptoms, time from symptom onset to needing mechanical ventilation is typically eight days.[4] Some cases in China initially presented with only chest tightness and palpitations.[49]

 

Loss of smell was identified as a common symptom of COVID‑19 in March 2020,[12][39] although perhaps not as common as initially reported.[38] A decreased sense of smell and/or disturbances in taste have also been reported.[50] Estimates for loss of smell range from 15%[38] to 30%.[12][39]

 

As is common with infections, there is a delay between the moment a person is first infected and the time he or she develops symptoms. This is called the incubation period. The incubation period for COVID‑19 is typically five to six days but may range from two to 14 days,[51][52] although 97.5% of people who develop symptoms will do so within 11.5 days of infection.[53]

 

A minority of cases do not develop noticeable symptoms at any point in time.[54][55] These asymptomatic carriers tend not to get tested, and their role in transmission is not yet fully known.[56][57] However, preliminary evidence suggests they may contribute to the spread of the disease.[58][59] In March 2020, the Korea Centers for Disease Control and Prevention (KCDC) reported that 20% of confirmed cases remained asymptomatic during their hospital stay.[59][60]

 

A number of neurological symptoms has been reported including seizures, stroke, encephalitis and Guillain-Barre syndrome.[61] Cardiovascular related complications may include heart failure, irregular electrical activity, blood clots, and heart inflammation.[62]

 

Cause

See also: Severe acute respiratory syndrome coronavirus 2

Transmission

Cough/sneeze droplets visualised in dark background using Tyndall scattering

Respiratory droplets produced when a man is sneezing visualised using Tyndall scattering

File:COVID19 in numbers- R0, the case fatality rate and why we need to flatten the curve.webm

A video discussing the basic reproduction number and case fatality rate in the context of the pandemic

Some details about how the disease is spread are still being determined.[16][18] The WHO and the U.S. Centers for Disease Control and Prevention (CDC) say it is primarily spread during close contact and by small droplets produced when people cough, sneeze or talk;[6][16] with close contact being within approximately 1–2 m (3–7 ft).[6][63] Both sputum and saliva can carry large viral loads.[64] Loud talking releases more droplets than normal talking.[65] A study in Singapore found that an uncovered cough can lead to droplets travelling up to 4.5 metres (15 feet).[66] An article published in March 2020 argued that advice on droplet distance might be based on 1930s research which ignored the effects of warm moist exhaled air surrounding the droplets and that an uncovered cough or sneeze can travel up to 8.2 metres (27 feet).[17]

  

Respiratory droplets may also be produced while breathing out, including when talking. Though the virus is not generally airborne,[6][67] the National Academy of Sciences has suggested that bioaerosol transmission may be possible.[68] In one study cited, air collectors positioned in the hallway outside of people's rooms yielded samples positive for viral RNA but finding infectious virus has proven elusive.[68] The droplets can land in the mouths or noses of people who are nearby or possibly be inhaled into the lungs.[16] Some medical procedures such as intubation and cardiopulmonary resuscitation (CPR) may cause respiratory secretions to be aerosolised and thus result in an airborne spread.[67] Initial studies suggested a doubling time of the number of infected persons of 6–7 days and a basic reproduction number (R0 ) of 2.2–2.7, but a study published on April 7, 2020, calculated a much higher median R0 value of 5.7 in Wuhan.[69]

 

It may also spread when one touches a contaminated surface, known as fomite transmission, and then touches one's eyes, nose or mouth.[6] While there are concerns it may spread via faeces, this risk is believed to be low.[6][16]

 

The virus is most contagious when people are symptomatic; though spread is may be possible before symptoms emerge and from those who never develop symptoms.[6][70] A portion of individuals with coronavirus lack symptoms.[71] The European Centre for Disease Prevention and Control (ECDC) says while it is not entirely clear how easily the disease spreads, one person generally infects two or three others.[18]

 

The virus survives for hours to days on surfaces.[6][18] Specifically, the virus was found to be detectable for one day on cardboard, for up to three days on plastic (polypropylene) and stainless steel (AISI 304), and for up to four hours on 99% copper.[21][23] This, however, varies depending on the humidity and temperature.[72][73] Surfaces may be decontaminated with many solutions (with one minute of exposure to the product achieving a 4 or more log reduction (99.99% reduction)), including 78–95% ethanol (alcohol used in spirits), 70–100% 2-propanol (isopropyl alcohol), the combination of 45% 2-propanol with 30% 1-propanol, 0.21% sodium hypochlorite (bleach), 0.5% hydrogen peroxide, or 0.23–7.5% povidone-iodine. Soap and detergent are also effective if correctly used; soap products degrade the virus' fatty protective layer, deactivating it, as well as freeing them from the skin and other surfaces.[74] Other solutions, such as benzalkonium chloride and chlorhexidine gluconate (a surgical disinfectant), are less effective.[75]

 

In a Hong Kong study, saliva samples were taken a median of two days after the start of hospitalization. In five of six patients, the first sample showed the highest viral load, and the sixth patient showed the highest viral load on the second day tested.[64]

 

Virology

Main article: Severe acute respiratory syndrome coronavirus 2

 

Illustration of SARSr-CoV virion

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a novel severe acute respiratory syndrome coronavirus, first isolated from three people with pneumonia connected to the cluster of acute respiratory illness cases in Wuhan.[76] All features of the novel SARS-CoV-2 virus occur in related coronaviruses in nature.[77] Outside the human body, the virus is killed by household soap, which bursts its protective bubble.[26]

 

SARS-CoV-2 is closely related to the original SARS-CoV.[78] It is thought to have a zoonotic origin. Genetic analysis has revealed that the coronavirus genetically clusters with the genus Betacoronavirus, in subgenus Sarbecovirus (lineage B) together with two bat-derived strains. It is 96% identical at the whole genome level to other bat coronavirus samples (BatCov RaTG13).[47] In February 2020, Chinese researchers found that there is only one amino acid difference in the binding domain of the S protein between the coronaviruses from pangolins and those from humans; however, whole-genome comparison to date found that at most 92% of genetic material was shared between pangolin coronavirus and SARS-CoV-2, which is insufficient to prove pangolins to be the intermediate host.[79]

 

Pathophysiology

The lungs are the organs most affected by COVID‑19 because the virus accesses host cells via the enzyme angiotensin-converting enzyme 2 (ACE2), which is most abundant in type II alveolar cells of the lungs. The virus uses a special surface glycoprotein called a "spike" (peplomer) to connect to ACE2 and enter the host cell.[80] The density of ACE2 in each tissue correlates with the severity of the disease in that tissue and some have suggested that decreasing ACE2 activity might be protective,[81][82] though another view is that increasing ACE2 using angiotensin II receptor blocker medications could be protective and these hypotheses need to be tested.[83] As the alveolar disease progresses, respiratory failure might develop and death may follow.[82]

 

The virus also affects gastrointestinal organs as ACE2 is abundantly expressed in the glandular cells of gastric, duodenal and rectal epithelium[84] as well as endothelial cells and enterocytes of the small intestine.[85]

 

ACE2 is present in the brain, and there is growing evidence of neurological manifestations in people with COVID‑19. It is not certain if the virus can directly infect the brain by crossing the barriers that separate the circulation of the brain and the general circulation. Other coronaviruses are able to infect the brain via a synaptic route to the respiratory centre in the medulla, through mechanoreceptors like pulmonary stretch receptors and chemoreceptors (primarily central chemoreceptors) within the lungs.[medical citation needed] It is possible that dysfunction within the respiratory centre further worsens the ARDS seen in COVID‑19 patients. Common neurological presentations include a loss of smell, headaches, nausea, and vomiting. Encephalopathy has been noted to occur in some patients (and confirmed with imaging), with some reports of detection of the virus after cerebrospinal fluid assays although the presence of oligoclonal bands seems to be a common denominator in these patients.[86]

 

The virus can cause acute myocardial injury and chronic damage to the cardiovascular system.[87] An acute cardiac injury was found in 12% of infected people admitted to the hospital in Wuhan, China,[88] and is more frequent in severe disease.[89] Rates of cardiovascular symptoms are high, owing to the systemic inflammatory response and immune system disorders during disease progression, but acute myocardial injuries may also be related to ACE2 receptors in the heart.[87] ACE2 receptors are highly expressed in the heart and are involved in heart function.[87][90] A high incidence of thrombosis (31%) and venous thromboembolism (25%) have been found in ICU patients with COVID‑19 infections and may be related to poor prognosis.[91][92] Blood vessel dysfunction and clot formation (as suggested by high D-dimer levels) are thought to play a significant role in mortality, incidences of clots leading to pulmonary embolisms, and ischaemic events within the brain have been noted as complications leading to death in patients infected with SARS-CoV-2. Infection appears to set off a chain of vasoconstrictive responses within the body, constriction of blood vessels within the pulmonary circulation has also been posited as a mechanism in which oxygenation decreases alongside with the presentation of viral pneumonia.[93]

 

Another common cause of death is complications related to the kidneys[93]—SARS-CoV-2 directly infects kidney cells, as confirmed in post-mortem studies. Acute kidney injury is a common complication and cause of death; this is more significant in patients with already compromised kidney function, especially in people with pre-existing chronic conditions such as hypertension and diabetes which specifically cause nephropathy in the long run.[94]

 

Autopsies of people who died of COVID‑19 have found diffuse alveolar damage (DAD), and lymphocyte-containing inflammatory infiltrates within the lung.[95]

 

Immunopathology

Although SARS-COV-2 has a tropism for ACE2-expressing epithelial cells of the respiratory tract, patients with severe COVID‑19 have symptoms of systemic hyperinflammation. Clinical laboratory findings of elevated IL-2, IL-7, IL-6, granulocyte-macrophage colony-stimulating factor (GM-CSF), interferon-γ inducible protein 10 (IP-10), monocyte chemoattractant protein 1 (MCP-1), macrophage inflammatory protein 1-α (MIP-1α), and tumour necrosis factor-α (TNF-α) indicative of cytokine release syndrome (CRS) suggest an underlying immunopathology.[96]

 

Additionally, people with COVID‑19 and acute respiratory distress syndrome (ARDS) have classical serum biomarkers of CRS, including elevated C-reactive protein (CRP), lactate dehydrogenase (LDH), D-dimer, and ferritin.[97]

 

Systemic inflammation results in vasodilation, allowing inflammatory lymphocytic and monocytic infiltration of the lung and the heart. In particular, pathogenic GM-CSF-secreting T-cells were shown to correlate with the recruitment of inflammatory IL-6-secreting monocytes and severe lung pathology in COVID‑19 patients.[98] Lymphocytic infiltrates have also been reported at autopsy.[95]

 

Diagnosis

Main article: COVID-19 testing

 

Demonstration of a nasopharyngeal swab for COVID-19 testing

 

CDC rRT-PCR test kit for COVID-19[99]

The WHO has published several testing protocols for the disease.[100] The standard method of testing is real-time reverse transcription polymerase chain reaction (rRT-PCR).[101] The test is typically done on respiratory samples obtained by a nasopharyngeal swab; however, a nasal swab or sputum sample may also be used.[25][102] Results are generally available within a few hours to two days.[103][104] Blood tests can be used, but these require two blood samples taken two weeks apart, and the results have little immediate value.[105] Chinese scientists were able to isolate a strain of the coronavirus and publish the genetic sequence so laboratories across the world could independently develop polymerase chain reaction (PCR) tests to detect infection by the virus.[9][106][107] As of 4 April 2020, antibody tests (which may detect active infections and whether a person had been infected in the past) were in development, but not yet widely used.[108][109][110] The Chinese experience with testing has shown the accuracy is only 60 to 70%.[111] The FDA in the United States approved the first point-of-care test on 21 March 2020 for use at the end of that month.[112]

 

Diagnostic guidelines released by Zhongnan Hospital of Wuhan University suggested methods for detecting infections based upon clinical features and epidemiological risk. These involved identifying people who had at least two of the following symptoms in addition to a history of travel to Wuhan or contact with other infected people: fever, imaging features of pneumonia, normal or reduced white blood cell count, or reduced lymphocyte count.[113]

 

A study asked hospitalised COVID‑19 patients to cough into a sterile container, thus producing a saliva sample, and detected the virus in eleven of twelve patients using RT-PCR. This technique has the potential of being quicker than a swab and involving less risk to health care workers (collection at home or in the car).[64]

 

Along with laboratory testing, chest CT scans may be helpful to diagnose COVID-19 in individuals with a high clinical suspicion of infection but are not recommended for routine screening.[26][27] Bilateral multilobar ground-glass opacities with a peripheral, asymmetric, and posterior distribution are common in early infection.[26] Subpleural dominance, crazy paving (lobular septal thickening with variable alveolar filling), and consolidation may appear as the disease progresses.[26][114]

 

In late 2019, WHO assigned the emergency ICD-10 disease codes U07.1 for deaths from lab-confirmed SARS-CoV-2 infection and U07.2 for deaths from clinically or epidemiologically diagnosed COVID‑19 without lab-confirmed SARS-CoV-2 infection.[115]

  

Typical CT imaging findings

 

CT imaging of rapid progression stage

Pathology

Few data are available about microscopic lesions and the pathophysiology of COVID‑19.[116][117] The main pathological findings at autopsy are:

 

Macroscopy: pleurisy, pericarditis, lung consolidation and pulmonary oedema

Four types of severity of viral pneumonia can be observed:

minor pneumonia: minor serous exudation, minor fibrin exudation

mild pneumonia: pulmonary oedema, pneumocyte hyperplasia, large atypical pneumocytes, interstitial inflammation with lymphocytic infiltration and multinucleated giant cell formation

severe pneumonia: diffuse alveolar damage (DAD) with diffuse alveolar exudates. DAD is the cause of acute respiratory distress syndrome (ARDS) and severe hypoxemia.

healing pneumonia: organisation of exudates in alveolar cavities and pulmonary interstitial fibrosis

plasmocytosis in BAL[118]

Blood: disseminated intravascular coagulation (DIC);[119] leukoerythroblastic reaction[120]

Liver: microvesicular steatosis

Prevention

See also: 2019–20 coronavirus pandemic § Prevention, flatten the curve, and workplace hazard controls for COVID-19

 

Progressively stronger mitigation efforts to reduce the number of active cases at any given time—known as "flattening the curve"—allows healthcare services to better manage the same volume of patients.[121][122][123] Likewise, progressively greater increases in healthcare capacity—called raising the line—such as by increasing bed count, personnel, and equipment, helps to meet increased demand.[124]

 

Mitigation attempts that are inadequate in strictness or duration—such as premature relaxation of distancing rules or stay-at-home orders—can allow a resurgence after the initial surge and mitigation.[122][125]

Preventive measures to reduce the chances of infection include staying at home, avoiding crowded places, keeping distance from others, washing hands with soap and water often and for at least 20 seconds, practising good respiratory hygiene, and avoiding touching the eyes, nose, or mouth with unwashed hands.[126][127][128] The CDC recommends covering the mouth and nose with a tissue when coughing or sneezing and recommends using the inside of the elbow if no tissue is available.[126] Proper hand hygiene after any cough or sneeze is encouraged.[126] The CDC has recommended the use of cloth face coverings in public settings where other social distancing measures are difficult to maintain, in part to limit transmission by asymptomatic individuals.[129] The U.S. National Institutes of Health guidelines do not recommend any medication for prevention of COVID‑19, before or after exposure to the SARS-CoV-2 virus, outside of the setting of a clinical trial.[130]

 

Social distancing strategies aim to reduce contact of infected persons with large groups by closing schools and workplaces, restricting travel, and cancelling large public gatherings.[131] Distancing guidelines also include that people stay at least 6 feet (1.8 m) apart.[132] There is no medication known to be effective at preventing COVID‑19.[133] After the implementation of social distancing and stay-at-home orders, many regions have been able to sustain an effective transmission rate ("Rt") of less than one, meaning the disease is in remission in those areas.[134]

 

As a vaccine is not expected until 2021 at the earliest,[135] a key part of managing COVID‑19 is trying to decrease the epidemic peak, known as "flattening the curve".[122] This is done by slowing the infection rate to decrease the risk of health services being overwhelmed, allowing for better treatment of current cases, and delaying additional cases until effective treatments or a vaccine become available.[122][125]

 

According to the WHO, the use of masks is recommended only if a person is coughing or sneezing or when one is taking care of someone with a suspected infection.[136] For the European Centre for Disease Prevention and Control (ECDC) face masks "... could be considered especially when visiting busy closed spaces ..." but "... only as a complementary measure ..."[137] Several countries have recommended that healthy individuals wear face masks or cloth face coverings (like scarves or bandanas) at least in certain public settings, including China,[138] Hong Kong,[139] Spain,[140] Italy (Lombardy region),[141] and the United States.[129]

 

Those diagnosed with COVID‑19 or who believe they may be infected are advised by the CDC to stay home except to get medical care, call ahead before visiting a healthcare provider, wear a face mask before entering the healthcare provider's office and when in any room or vehicle with another person, cover coughs and sneezes with a tissue, regularly wash hands with soap and water and avoid sharing personal household items.[30][142] The CDC also recommends that individuals wash hands often with soap and water for at least 20 seconds, especially after going to the toilet or when hands are visibly dirty, before eating and after blowing one's nose, coughing or sneezing. It further recommends using an alcohol-based hand sanitiser with at least 60% alcohol, but only when soap and water are not readily available.[126]

 

For areas where commercial hand sanitisers are not readily available, the WHO provides two formulations for local production. In these formulations, the antimicrobial activity arises from ethanol or isopropanol. Hydrogen peroxide is used to help eliminate bacterial spores in the alcohol; it is "not an active substance for hand antisepsis". Glycerol is added as a humectant.[143]

  

Prevention efforts are multiplicative, with effects far beyond that of a single spread. Each avoided case leads to more avoided cases down the line, which in turn can stop the outbreak in its tracks.

 

File:COVID19 W ENG.ogv

Handwashing instructions

Management

People are managed with supportive care, which may include fluid therapy, oxygen support, and supporting other affected vital organs.[144][145][146] The CDC recommends that those who suspect they carry the virus wear a simple face mask.[30] Extracorporeal membrane oxygenation (ECMO) has been used to address the issue of respiratory failure, but its benefits are still under consideration.[41][147] Personal hygiene and a healthy lifestyle and diet have been recommended to improve immunity.[148] Supportive treatments may be useful in those with mild symptoms at the early stage of infection.[149]

 

The WHO, the Chinese National Health Commission, and the United States' National Institutes of Health have published recommendations for taking care of people who are hospitalised with COVID‑19.[130][150][151] Intensivists and pulmonologists in the U.S. have compiled treatment recommendations from various agencies into a free resource, the IBCC.[152][153]

 

Medications

See also: Coronavirus disease 2019 § Research

As of April 2020, there is no specific treatment for COVID‑19.[6][133] Research is, however, ongoing. For symptoms, some medical professionals recommend paracetamol (acetaminophen) over ibuprofen for first-line use.[154][155][156] The WHO and NIH do not oppose the use of non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen for symptoms,[130][157] and the FDA says currently there is no evidence that NSAIDs worsen COVID‑19 symptoms.[158]

 

While theoretical concerns have been raised about ACE inhibitors and angiotensin receptor blockers, as of 19 March 2020, these are not sufficient to justify stopping these medications.[130][159][160][161] Steroids, such as methylprednisolone, are not recommended unless the disease is complicated by acute respiratory distress syndrome.[162][163]

 

Medications to prevent blood clotting have been suggested for treatment,[91] and anticoagulant therapy with low molecular weight heparin appears to be associated with better outcomes in severe COVID‐19 showing signs of coagulopathy (elevated D-dimer).[164]

 

Protective equipment

See also: COVID-19 related shortages

 

The CDC recommends four steps to putting on personal protective equipment (PPE).[165]

Precautions must be taken to minimise the risk of virus transmission, especially in healthcare settings when performing procedures that can generate aerosols, such as intubation or hand ventilation.[166] For healthcare professionals caring for people with COVID‑19, the CDC recommends placing the person in an Airborne Infection Isolation Room (AIIR) in addition to using standard precautions, contact precautions, and airborne precautions.[167]

 

The CDC outlines the guidelines for the use of personal protective equipment (PPE) during the pandemic. The recommended gear is a PPE gown, respirator or facemask, eye protection, and medical gloves.[168][169]

 

When available, respirators (instead of facemasks) are preferred.[170] N95 respirators are approved for industrial settings but the FDA has authorised the masks for use under an Emergency Use Authorisation (EUA). They are designed to protect from airborne particles like dust but effectiveness against a specific biological agent is not guaranteed for off-label uses.[171] When masks are not available, the CDC recommends using face shields or, as a last resort, homemade masks.[172]

 

Mechanical ventilation

Most cases of COVID‑19 are not severe enough to require mechanical ventilation or alternatives, but a percentage of cases are.[173][174] The type of respiratory support for individuals with COVID‑19 related respiratory failure is being actively studied for people in the hospital, with some evidence that intubation can be avoided with a high flow nasal cannula or bi-level positive airway pressure.[175] Whether either of these two leads to the same benefit for people who are critically ill is not known.[176] Some doctors prefer staying with invasive mechanical ventilation when available because this technique limits the spread of aerosol particles compared to a high flow nasal cannula.[173]

 

Severe cases are most common in older adults (those older than 60 years,[173] and especially those older than 80 years).[177] Many developed countries do not have enough hospital beds per capita, which limits a health system's capacity to handle a sudden spike in the number of COVID‑19 cases severe enough to require hospitalisation.[178] This limited capacity is a significant driver behind calls to flatten the curve.[178] One study in China found 5% were admitted to intensive care units, 2.3% needed mechanical support of ventilation, and 1.4% died.[41] In China, approximately 30% of people in hospital with COVID‑19 are eventually admitted to ICU.[4]

 

Acute respiratory distress syndrome

Main article: Acute respiratory distress syndrome

Mechanical ventilation becomes more complex as acute respiratory distress syndrome (ARDS) develops in COVID‑19 and oxygenation becomes increasingly difficult.[179] Ventilators capable of pressure control modes and high PEEP[180] are needed to maximise oxygen delivery while minimising the risk of ventilator-associated lung injury and pneumothorax.[181] High PEEP may not be available on older ventilators.

 

Options for ARDS[179]

TherapyRecommendations

High-flow nasal oxygenFor SpO2 <93%. May prevent the need for intubation and ventilation

Tidal volume6mL per kg and can be reduced to 4mL/kg

Plateau airway pressureKeep below 30 cmH2O if possible (high respiratory rate (35 per minute) may be required)

Positive end-expiratory pressureModerate to high levels

Prone positioningFor worsening oxygenation

Fluid managementGoal is a negative balance of 0.5–1.0L per day

AntibioticsFor secondary bacterial infections

GlucocorticoidsNot recommended

Experimental treatment

See also: § Research

Research into potential treatments started in January 2020,[182] and several antiviral drugs are in clinical trials.[183][184] Remdesivir appears to be the most promising.[133] Although new medications may take until 2021 to develop,[185] several of the medications being tested are already approved for other uses or are already in advanced testing.[186] Antiviral medication may be tried in people with severe disease.[144] The WHO recommended volunteers take part in trials of the effectiveness and safety of potential treatments.[187]

 

The FDA has granted temporary authorisation to convalescent plasma as an experimental treatment in cases where the person's life is seriously or immediately threatened. It has not undergone the clinical studies needed to show it is safe and effective for the disease.[188][189][190]

 

Information technology

See also: Contact tracing and Government by algorithm

In February 2020, China launched a mobile app to deal with the disease outbreak.[191] Users are asked to enter their name and ID number. The app can detect 'close contact' using surveillance data and therefore a potential risk of infection. Every user can also check the status of three other users. If a potential risk is detected, the app not only recommends self-quarantine, it also alerts local health officials.[192]

 

Big data analytics on cellphone data, facial recognition technology, mobile phone tracking, and artificial intelligence are used to track infected people and people whom they contacted in South Korea, Taiwan, and Singapore.[193][194] In March 2020, the Israeli government enabled security agencies to track mobile phone data of people supposed to have coronavirus. The measure was taken to enforce quarantine and protect those who may come into contact with infected citizens.[195] Also in March 2020, Deutsche Telekom shared aggregated phone location data with the German federal government agency, Robert Koch Institute, to research and prevent the spread of the virus.[196] Russia deployed facial recognition technology to detect quarantine breakers.[197] Italian regional health commissioner Giulio Gallera said he has been informed by mobile phone operators that "40% of people are continuing to move around anyway".[198] German government conducted a 48 hours weekend hackathon with more than 42.000 participants.[199][200] Two million people in the UK used an app developed in March 2020 by King's College London and Zoe to track people with COVID‑19 symptoms.[201] Also, the president of Estonia, Kersti Kaljulaid, made a global call for creative solutions against the spread of coronavirus.[202]

 

Psychological support

See also: Mental health during the 2019–20 coronavirus pandemic

Individuals may experience distress from quarantine, travel restrictions, side effects of treatment, or fear of the infection itself. To address these concerns, the National Health Commission of China published a national guideline for psychological crisis intervention on 27 January 2020.[203][204]

 

The Lancet published a 14-page call for action focusing on the UK and stated conditions were such that a range of mental health issues was likely to become more common. BBC quoted Rory O'Connor in saying, "Increased social isolation, loneliness, health anxiety, stress and an economic downturn are a perfect storm to harm people's mental health and wellbeing."[205][206]

 

Prognosis

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The severity of diagnosed cases in China

The severity of diagnosed COVID-19 cases in China[207]

Case fatality rates for COVID-19 by age by country.

Case fatality rates by age group:

China, as of 11 February 2020[208]

South Korea, as of 15 April 2020[209]

Spain, as of 24 April 2020[210]

Italy, as of 23 April 2020[211]

Case fatality rate depending on other health problems

Case fatality rate in China depending on other health problems. Data through 11 February 2020.[208]

Case fatality rate by country and number of cases

The number of deaths vs total cases by country and approximate case fatality rate[212]

The severity of COVID‑19 varies. The disease may take a mild course with few or no symptoms, resembling other common upper respiratory diseases such as the common cold. Mild cases typically recover within two weeks, while those with severe or critical diseases may take three to six weeks to recover. Among those who have died, the time from symptom onset to death has ranged from two to eight weeks.[47]

 

Children make up a small proportion of reported cases, with about 1% of cases being under 10 years, and 4% aged 10-19 years.[22] They are likely to have milder symptoms and a lower chance of severe disease than adults; in those younger than 50 years, the risk of death is less than 0.5%, while in those older than 70 it is more than 8%.[213][214][215] Pregnant women may be at higher risk for severe infection with COVID-19 based on data from other similar viruses, like SARS and MERS, but data for COVID-19 is lacking.[216][217] In China, children acquired infections mainly through close contact with their parents or other family members who lived in Wuhan or had traveled there.[213]

 

In some people, COVID‑19 may affect the lungs causing pneumonia. In those most severely affected, COVID-19 may rapidly progress to acute respiratory distress syndrome (ARDS) causing respiratory failure, septic shock, or multi-organ failure.[218][219] Complications associated with COVID‑19 include sepsis, abnormal clotting, and damage to the heart, kidneys, and liver. Clotting abnormalities, specifically an increase in prothrombin time, have been described in 6% of those admitted to hospital with COVID-19, while abnormal kidney function is seen in 4% of this group.[220] Approximately 20-30% of people who present with COVID‑19 demonstrate elevated liver enzymes (transaminases).[133] Liver injury as shown by blood markers of liver damage is frequently seen in severe cases.[221]

 

Some studies have found that the neutrophil to lymphocyte ratio (NLR) may be helpful in early screening for severe illness.[222]

 

Most of those who die of COVID‑19 have pre-existing (underlying) conditions, including hypertension, diabetes mellitus, and cardiovascular disease.[223] The Istituto Superiore di Sanità reported that out of 8.8% of deaths where medical charts were available for review, 97.2% of sampled patients had at least one comorbidity with the average patient having 2.7 diseases.[224] According to the same report, the median time between the onset of symptoms and death was ten days, with five being spent hospitalised. However, patients transferred to an ICU had a median time of seven days between hospitalisation and death.[224] In a study of early cases, the median time from exhibiting initial symptoms to death was 14 days, with a full range of six to 41 days.[225] In a study by the National Health Commission (NHC) of China, men had a death rate of 2.8% while women had a death rate of 1.7%.[226] Histopathological examinations of post-mortem lung samples show diffuse alveolar damage with cellular fibromyxoid exudates in both lungs. Viral cytopathic changes were observed in the pneumocytes. The lung picture resembled acute respiratory distress syndrome (ARDS).[47] In 11.8% of the deaths reported by the National Health Commission of China, heart damage was noted by elevated levels of troponin or cardiac arrest.[49] According to March data from the United States, 89% of those hospitalised had preexisting conditions.[227]

 

The availability of medical resources and the socioeconomics of a region may also affect mortality.[228] Estimates of the mortality from the condition vary because of those regional differences,[229] but also because of methodological difficulties. The under-counting of mild cases can cause the mortality rate to be overestimated.[230] However, the fact that deaths are the result of cases contracted in the past can mean the current mortality rate is underestimated.[231][232] Smokers were 1.4 times more likely to have severe symptoms of COVID‑19 and approximately 2.4 times more likely to require intensive care or die compared to non-smokers.[233]

 

Concerns have been raised about long-term sequelae of the disease. The Hong Kong Hospital Authority found a drop of 20% to 30% in lung capacity in some people who recovered from the disease, and lung scans suggested organ damage.[234] This may also lead to post-intensive care syndrome following recovery.[235]

 

Case fatality rates (%) by age and country

Age0–910–1920–2930–3940–4950–5960–6970–7980-8990+

China as of 11 February[208]0.00.20.20.20.41.33.68.014.8

Denmark as of 25 April[236]0.24.515.524.940.7

Italy as of 23 April[211]0.20.00.10.40.92.610.024.930.826.1

Netherlands as of 17 April[237]0.00.30.10.20.51.57.623.230.029.3

Portugal as of 24 April[238]0.00.00.00.00.30.62.88.516.5

S. Korea as of 15 April[209]0.00.00.00.10.20.72.59.722.2

Spain as of 24 April[210]0.30.40.30.30.61.34.413.220.320.1

Switzerland as of 25 April[239]0.90.00.00.10.00.52.710.124.0

Case fatality rates (%) by age in the United States

Age0–1920–4445–5455–6465–7475–8485+

United States as of 16 March[240]0.00.1–0.20.5–0.81.4–2.62.7–4.94.3–10.510.4–27.3

Note: The lower bound includes all cases. The upper bound excludes cases that were missing data.

Estimate of infection fatality rates and probability of severe disease course (%) by age based on cases from China[241]

0–910–1920–2930–3940–4950–5960–6970–7980+

Severe disease0.0

(0.0–0.0)0.04

(0.02–0.08)1.0

(0.62–2.1)3.4

(2.0–7.0)4.3

(2.5–8.7)8.2

(4.9–17)11

(7.0–24)17

(9.9–34)18

(11–38)

Death0.0016

(0.00016–0.025)0.0070

(0.0015–0.050)0.031

(0.014–0.092)0.084

(0.041–0.19)0.16

(0.076–0.32)0.60

(0.34–1.3)1.9

(1.1–3.9)4.3

(2.5–8.4)7.8

(3.8–13)

Total infection fatality rate is estimated to be 0.66% (0.39–1.3). Infection fatality rate is fatality per all infected individuals, regardless of whether they were diagnosed or had any symptoms. Numbers in parentheses are 95% credible intervals for the estimates.

Reinfection

As of March 2020, it was unknown if past infection provides effective and long-term immunity in people who recover from the disease.[242] Immunity is seen as likely, based on the behaviour of other coronaviruses,[243] but cases in which recovery from COVID‑19 have been followed by positive tests for coronavirus at a later date have been reported.[244][245][246][247] These cases are believed to be worsening of a lingering infection rather than re-infection.[247]

 

History

Main article: Timeline of the 2019–20 coronavirus pandemic

The virus is thought to be natural and has an animal origin,[77] through spillover infection.[248] The actual origin is unknown, but by December 2019 the spread of infection was almost entirely driven by human-to-human transmission.[208][249] A study of the first 41 cases of confirmed COVID‑19, published in January 2020 in The Lancet, revealed the earliest date of onset of symptoms as 1 December 2019.[250][251][252] Official publications from the WHO reported the earliest onset of symptoms as 8 December 2019.[253] Human-to-human transmission was confirmed by the WHO and Chinese authorities by 20 January 2020.[254][255]

 

Epidemiology

Main article: 2019–20 coronavirus pandemic

Several measures are commonly used to quantify mortality.[256] These numbers vary by region and over time and are influenced by the volume of testing, healthcare system quality, treatment options, time since the initial outbreak, and population characteristics such as age, sex, and overall health.[257]

 

The death-to-case ratio reflects the number of deaths divided by the number of diagnosed cases within a given time interval. Based on Johns Hopkins University statistics, the global death-to-case ratio is 7.0% (203,044/2,899,830) as of 26 April 2020.[7] The number varies by region.[258]

 

Other measures include the case fatality rate (CFR), which reflects the percent of diagnosed individuals who die from a disease, and the infection fatality rate (IFR), which reflects the percent of infected individuals (diagnosed and undiagnosed) who die from a disease. These statistics are not time-bound and follow a specific population from infection through case resolution. Many academics have attempted to calculate these numbers for specific populations.[259]

  

Total confirmed cases over time

 

Total deaths over time

 

Total confirmed cases of COVID‑19 per million people, 10 April 2020[260]

 

Total confirmed deaths due to COVID‑19 per million people, 10 April 2020[261]

Infection fatality rate

Our World in Data states that as of March 25, 2020, the infection fatality rate (IFR) cannot be accurately calculated.[262] In February, the World Health Organization estimated the IFR at 0.94%, with a confidence interval between 0.37 percent to 2.9 percent.[263] The University of Oxford Centre for Evidence-Based Medicine (CEBM) estimated a global CFR of 0.72 percent and IFR of 0.1 percent to 0.36 percent.[264] According to CEBM, random antibody testing in Germany suggested an IFR of 0.37 percent there.[264] Firm lower limits to local infection fatality rates were established, such as in Bergamo province, where 0.57% of the population has died, leading to a minimum IFR of 0.57% in the province. This population fatality rate (PFR) minimum increases as more people get infected and run through their disease.[265][266] Similarly, as of April 22 in the New York City area, there were 15,411 deaths confirmed from COVID-19, and 19,200 excess deaths.[267] Very recently, the first results of antibody testing have come in, but there are no valid scientific reports based on them available yet. A Bloomberg Opinion piece provides a survey.[268][269]

 

Sex differences

Main article: Gendered impact of the 2019–20 coronavirus pandemic

The impact of the pandemic and its mortality rate are different for men and women.[270] Mortality is higher in men in studies conducted in China and Italy.[271][272][273] The highest risk for men is in their 50s, with the gap between men and women closing only at 90.[273] In China, the death rate was 2.8 percent for men and 1.7 percent for women.[273] The exact reasons for this sex-difference are not known, but genetic and behavioural factors could be a reason.[270] Sex-based immunological differences, a lower prevalence of smoking in women, and men developing co-morbid conditions such as hypertension at a younger age than women could have contributed to the higher mortality in men.[273] In Europe, of those infected with COVID‑19, 57% were men; of those infected with COVID‑19 who also died, 72% were men.[274] As of April 2020, the U.S. government is not tracking sex-related data of COVID‑19 infections.[275] Research has shown that viral illnesses like Ebola, HIV, influenza, and SARS affect men and women differently.[275] A higher percentage of health workers, particularly nurses, are women, and they have a higher chance of being exposed to the virus.[276] School closures, lockdowns, and reduced access to healthcare following the 2019–20 coronavirus pandemic may differentially affect the genders and possibly exaggerate existing gender disparity.[270][277]

 

Society and culture

Name

During the initial outbreak in Wuhan, China, the virus and disease were commonly referred to as "coronavirus" and "Wuhan coronavirus",[278][279][280] with the disease sometimes called "Wuhan pneumonia".[281][282] In the past, many diseases have been named after geographical locations, such as the Spanish flu,[283] Middle East Respiratory Syndrome, and Zika virus.[284]

 

In January 2020, the World Health Organisation recommended 2019-nCov[285] and 2019-nCoV acute respiratory disease[286] as interim names for the virus and disease per 2015 guidance and international guidelines against using geographical locations (e.g. Wuhan, China), animal species or groups of people in disease and virus names to prevent social stigma.[287][288][289]

 

The official names COVID‑19 and SARS-CoV-2 were issued by the WHO on 11 February 2020.[290] WHO chief Tedros Adhanom Ghebreyesus explained: CO for corona, VI for virus, D for disease and 19 for when the outbreak was first identified (31 December 2019).[291] The WHO additionally uses "the COVID‑19 virus" and "the virus responsible for COVID‑19" in public communications.[290] Both the disease and virus are commonly referred to as "coronavirus" in the media and public discourse.

 

Misinformation

Main article: Misinformation related to the 2019–20 coronavirus pandemic

After the initial outbreak of COVID‑19, conspiracy theories, misinformation, and disinformation emerged regarding the origin, scale, prevention, treatment, and other aspects of the disease and rapidly spread online.[292][293][294][295]

 

Protests

Beginning April 17, 2020, news media began reporting on a wave of demonstrations protesting against state-mandated quarantine restrictions in in Michigan, Ohio, and Kentucky.[296][297]

 

Other animals

Humans appear to be capable of spreading the virus to some other animals. A domestic cat in Liège, Belgium, tested positive after it started showing symptoms (diarrhoea, vomiting, shortness of breath) a week later than its owner, who was also positive.[298] Tigers at the Bronx Zoo in New York, United States, tested positive for the virus and showed symptoms of COVID‑19, including a dry cough and loss of appetite.[299]

 

A study on domesticated animals inoculated with the virus found that cats and ferrets appear to be "highly susceptible" to the disease, while dogs appear to be less susceptible, with lower levels of viral replication. The study failed to find evidence of viral replication in pigs, ducks, and chickens.[300]

 

Research

Main article: COVID-19 drug development

No medication or vaccine is approved to treat the disease.[186] International research on vaccines and medicines in COVID‑19 is underway by government organisations, academic groups, and industry researchers.[301][302] In March, the World Health Organisation initiated the "SOLIDARITY Trial" to assess the treatment effects of four existing antiviral compounds with the most promise of efficacy.[303]

 

Vaccine

Main article: COVID-19 vaccine

There is no available vaccine, but various agencies are actively developing vaccine candidates. Previous work on SARS-CoV is being used because both SARS-CoV and SARS-CoV-2 use the ACE2 receptor to enter human cells.[304] Three vaccination strategies are being investigated. First, researchers aim to build a whole virus vaccine. The use of such a virus, be it inactive or dead, aims to elicit a prompt immune response of the human body to a new infection with COVID‑19. A second strategy, subunit vaccines, aims to create a vaccine that sensitises the immune system to certain subunits of the virus. In the case of SARS-CoV-2, such research focuses on the S-spike protein that helps the virus intrude the ACE2 enzyme receptor. A third strategy is that of the nucleic acid vaccines (DNA or RNA vaccines, a novel technique for creating a vaccination). Experimental vaccines from any of these strategies would have to be tested for safety and efficacy.[305]

 

On 16 March 2020, the first clinical trial of a vaccine started with four volunteers in Seattle, United States. The vaccine contains a harmless genetic code copied from the virus that causes the disease.[306]

 

Antibody-dependent enhancement has been suggested as a potential challenge for vaccine development for SARS-COV-2, but this is controversial.[307]

 

Medications

Main article: COVID-19 drug repurposing research

At least 29 phase II–IV efficacy trials in COVID‑19 were concluded in March 2020 or scheduled to provide results in April from hospitals in China.[308][309] There are more than 300 active clinical trials underway as of April 2020.[133] Seven trials were evaluating already approved treatments, including four studies on hydroxychloroquine or chloroquine.[309] Repurposed antiviral drugs make up most of the Chinese research, with nine phase III trials on remdesivir across several countries due to report by the end of April.[308][309] Other candidates in trials include vasodilators, corticosteroids, immune therapies, lipoic acid, bevacizumab, and recombinant angiotensin-converting enzyme 2.[309]

 

The COVID‑19 Clinical Research Coalition has goals to 1) facilitate rapid reviews of clinical trial proposals by ethics committees and national regulatory agencies, 2) fast-track approvals for the candidate therapeutic compounds, 3) ensure standardised and rapid analysis of emerging efficacy and safety data and 4) facilitate sharing of clinical trial outcomes before publication.[310][311]

 

Several existing medications are being evaluated for the treatment of COVID‑19,[186] including remdesivir, chloroquine, hydroxychloroquine, lopinavir/ritonavir, and lopinavir/ritonavir combined with interferon beta.[303][312] There is tentative evidence for efficacy by remdesivir, as of March 2020.[313][314] Clinical improvement was observed in patients treated with compassionate-use remdesivir.[315] Remdesivir inhibits SARS-CoV-2 in vitro.[316] Phase III clinical trials are underway in the U.S., China, and Italy.[186][308][317]

 

In 2020, a trial found that lopinavir/ritonavir was ineffective in the treatment of severe illness.[318] Nitazoxanide has been recommended for further in vivo study after demonstrating low concentration inhibition of SARS-CoV-2.[316]

 

There are mixed results as of 3 April 2020 as to the effectiveness of hydroxychloroquine as a treatment for COVID‑19, with some studies showing little or no improvement.[319][320] The studies of chloroquine and hydroxychloroquine with or without azithromycin have major limitations that have prevented the medical community from embracing these therapies without further study.[133]

 

Oseltamivir does not inhibit SARS-CoV-2 in vitro and has no known role in COVID‑19 treatment.[133]

 

Anti-cytokine storm

Cytokine release syndrome (CRS) can be a complication in the later stages of severe COVID‑19. There is preliminary evidence that hydroxychloroquine may have anti-cytokine storm properties.[321]

 

Tocilizumab has been included in treatment guidelines by China's National Health Commission after a small study was completed.[322][323] It is undergoing a phase 2 non-randomised trial at the national level in Italy after showing positive results in people with severe disease.[324][325] Combined with a serum ferritin blood test to identify cytokine storms, it is meant to counter such developments, which are thought to be the cause of death in some affected people.[326][327][328] The interleukin-6 receptor antagonist was approved by the FDA to undergo a phase III clinical trial assessing the medication's impact on COVID‑19 based on retrospective case studies for the treatment of steroid-refractory cytokine release syndrome induced by a different cause, CAR T cell therapy, in 2017.[329] To date, there is no randomised, controlled evidence that tocilizumab is an efficacious treatment for CRS. Prophylactic tocilizumab has been shown to increase serum IL-6 levels by saturating the IL-6R, driving IL-6 across the blood-brain barrier, and exacerbating neurotoxicity while having no impact on the incidence of CRS.[330]

 

Lenzilumab, an anti-GM-CSF monoclonal antibody, is protective in murine models for CAR T cell-induced CRS and neurotoxicity and is a viable therapeutic option due to the observed increase of pathogenic GM-CSF secreting T-cells in hospitalised patients with COVID‑19.[331]

 

The Feinstein Institute of Northwell Health announced in March a study on "a human antibody that may prevent the activity" of IL-6.[332]

 

Passive antibodies

Transferring purified and concentrated antibodies produced by the immune systems of those who have recovered from COVID‑19 to people who need them is being investigated as a non-vaccine method of passive immunisation.[333] This strategy was tried for SARS with inconclusive results.[333] Viral neutralisation is the anticipated mechanism of action by which passive antibody therapy can mediate defence against SARS-CoV-2. Other mechanisms, however, such as antibody-dependent cellular cytotoxicity and/or phagocytosis, may be possible.[333] Other forms of passive antibody therapy, for example, using manufactured monoclonal antibodies, are in development.[333] Production of convalescent serum, which consists of the liquid portion of the blood from recovered patients and contains antibodies specific to this virus, could be increased for quicker deployment.[334]

  

en.wikipedia.org/wiki/Coronavirus_disease_2019

Pentax SMC 20mm f2.8 + flash

 

Thanks for all your comments and faves, much appreciated as always.

 

www.youtube.com/watch?v=xF4Pr5yVbo4

Dutch getting his cardio in!

Or does it...

Ethiopia, 2005: Are you up-to-date? From 24 to 30 April, World Immunization Week 2014 urges everyone to ask this question for themselves and their children. Immunization protects against the suffering caused by vaccine-preventable diseases and saves 2–3 million lives each year. But staying up-to-date on inoculations is critical to ensure lasting immunity. A health worker administers a dose of oral polio vaccine to a baby, in Tigray Region.

 

© UNICEF/NYHQ2005-0560/Boris Heger

 

To see more: www.unicef.org/photography

 

Also download the UNICEF Photography iPhone app here

Nothing is entirely immune to the harsh environment of space. Out there, things and organisms degrade at a faster pace and in different ways. To understand how materials age beyond Earth’s atmosphere, up to 141 samples are spending a minimum of six months exposed to outer space for the Euro Material Ageing experiment.

 

Radiation, vacuum, temperature extremes and even space debris are hitting this selection of inorganic materials on Bartolomeo, Europe’s ‘front porch’ on the International Space Station.

 

No filters or protection allowed, each sample has a bare surface of 20 millimetres cramped between two aluminium plates. The diverse palette in this image shows metallic glass, ceramic composites, silicon, diamond-like carbon, carbon fibres and plastics, among others.

 

Europe has years of experience in sending biology samples to space, but this is the first time ESA and the French space agency CNES expose inorganic materials outside the Space Station.

 

NASA astronauts Sunita Williams and Nick Hague used the Station’s 17-metre-long robotic arm last December to place the Nanoracks airlock on Bartolomeo, where the experiment is facing the full spectrum of space environment hazards.

 

As Nick Hague said in a social media post, “Materials research is critical to our exploration of space. Vacuum, extreme hot and cold, radiation – these are the harsh realities of the space environment. The right materials can help us survive in space and dare to go further, and can also improve life on Earth!”

 

Euro Material Ageing is testing how exposure to space can be bad for the health of spacecraft components. Whether a mission is orbiting Earth or operates in deep space, unwanted effects include discoloration, embrittlement and buckling.

 

The Space Station experiences frequent changes from sunlight to darkness while circling our planet. Materials go through drastic temperature shifts from up to 150°C in sunlight down to –150°C in the shade. Such thermal stresses lead to accelerated ageing, potential cracking and misalignment.

 

Samples are exposed to highly reactive atomic oxygen formed at the topmost fringes of the atmosphere and known to eat away satellite surfaces. Materials in this experiment will also cope with ‘outgassing’ in vacuum – the gradual boiling away of chemicals and solvents – which could contaminate sensitive satellite surfaces such as lenses.

 

Results from the Euro Material Ageing experiment could inform the design of fire-retardant and rust-resistant materials, and better protection for satellites could in turn help improve plastic siding for your house.

 

The exposure time is planned between six and 18 months. After completion, the facility will be transferred back inside the International Space Station. A new set of samples will be waiting for a second immersion into the harshness of space.

 

Credits: ESA/NASA

Contagion Battle

It's an embarrassing confession to admit publicly, but yes, I still watch Survivor.

 

Yes, the show where they vote each other off the island. Yes, the one where the guy walked around naked on the beach twenty years ago. Yes, I still have cable. Yes, I know this is profoundly uncool. Yes, I know that no one watches this show. Yes, I know I am super lame.

 

I watched the first season back in 2000 with my mom and my grandfather. We loved dissecting the psychology and strategy that went into the game. It was very exciting. You may remember that the players need to "outwit, outplay, and outlast" each other to achieve the title of "sole survivor." And there is only one sole survivor each season. Only one winner.

 

Which brings me back to photography... There are a host of common subjects that I photograph each season. Right now it's fall, and I have a number of photos of the forest floor blanketed in leaves. In the winter, I collect photos of patterns in the ice. In the spring and summer, there are ferns and lily pads. Maybe they are cliches, but they are also all unique, fleeting scenes. All personal to the photographer. I don't go out with a plan to photograph these subjects, but you never know when one will catch your eye. And wherever you hike, there they are right at your feet. Little unnoticed scenes, waiting for someone to notice them.

 

But in order to avoid viewer fatigue, I need to curate these images heavily. I could probably post a fern photo every week of the year that I think is interesting, but I doubt anyone else would. So I edit. A lot.

 

What you have here is the winner. The sole survivor. My favorite fern photo from this summer. I made this one near the Mount Osceola Trail parking lot along Tripoli Road. I was the first car in the lot that morning, and in the dawn light a half a mile before turning into the lot, I drove past a deer and then a bear. Both scampered across the road into the woods. In addition to this scene, I found another really nice composition of ferns near the parking lot. And about halfway up the mountain I found some perfect uncurling lime green ferns. Those photos were nice - they made the merge - but not as nice as this one. The tribe has spoken.

Congrats to Prellis on their progress on externalizing the human immune system with a lab-grown version of a human lymph node (as imaged here).

 

From TechCrunch today: “By creating this immune system in a dish, we can actually test if those therapeutics are going to elicit an immune response before it goes into a human,” founder and CEO Melanie Matheu told TechCrunch. “Our company’s edge is that EXIS is out of the box, fully human.”

 

Prellis’ approach is to model the immune system in miniature and develop a cadre of drug candidates by mining immune responses. Matheu calls it “natural intelligence” as opposed to artificial intelligence.

 

The company can create 1,200 organoids from one blood draw, challenge those immune systems with a particular antigen, and see what each immune system comes up with. That process, she says, can be done with different blood donors with different immune system characteristics to create a plethora of responses to analyze.

 

Matheu says the company has developed antibodies responsive to SARS-CoV-2, Influenza A and Marburg Hemorrhagic Fever (these results haven’t been published). The company is developing partnerships with five drug companies"

Yasmin and I haven't taken photos in a while so we did this on the weekend :)

 

I'm going to the hospital tomorrow to find out more about the immune deficiency and the treatments I'll need. Wish me luck <3

Welcome to your second judging ladies! This week you girls had to get your sugar teeth ready for your theme "Candy, Candy, Candy!" Last week Raina chose Winter and Jaymee for immunity with her so no matter what they won't be eliminated! This weeks guest judge is a previous model in Coolbraatz BNTM Cycle 3 Miku Hudson (XDollywoodX)! Now let's get to judging!

 

(This is in no particular order!)

 

Shayla- www.flickr.com/photos/60532297@N05/8431718210/:

 

Miku: Oh la la! I get so much Hollywood Glamour feels here! The positive? Your outfit! That coat is to die for! The background is good too! But I really can't stand "hands on the hips" 101 for theme. BUT, you made it work! Good job!

 

Mr. Bratz: First welcome back to the competition! You look fierce! Your pose is stunning but pretty basic but you definitely stand out from everything in the photo!

 

Izzy- www.flickr.com/photos/beautiful30bratz/8430445847/in/phot...:

 

Mr. Bratz: Woah! Huge step up from last week! Your pose is super cute and your face is adorable!

 

Miku: You look so fun and geekly-chic! The glasses were a nice touch! Love the pose too. But it's just the eyes that ruin the photo. If it was facing the camera more, perfection!

 

Winter- www.flickr.com/photos/crushphobia/8435821987/:

 

Miku: Winter.... I LOVE IT! You look so magical here and I love your take on it! The hair... my god <3 BUT........... I just don't like the fact that you were suppose to be representing twizzlers but I thought it was marshmellows. But this still amazing! Don't forget that!

 

Mr. Bratz: Do you ever stop getting any better! Hehe just kidding! This is stunning! Your pose is very soft but fierce and your face is very gorgeous!

 

Jaymee- www.flickr.com/photos/86834980@N07/8435164002/in/photostream:

 

Mr. Bratz: Stunning! You look fabulous! Your pose is very cute also! But it is very obvious you edited her in because in between her legs is a white background!

 

Miku: Your hair is gorgeous! Pink brings out so much of your face, consider that a makeover? ;) But I'm not in love with your pose and face. You look so bored! I also wish you had a different outfit. It makes you look a bit chubby... If you worked more on the outfit, it would've been a better photo.

 

Tessa- www.flickr.com/photos/71921331@N06/8452223659/:

 

Miku: I like your dress and your background but that's it. You face is wondering off and your arms are stiff. Overall, I think you could've done better considering you have one of my favorite faces.

 

Mr. Bratz: I love this! Your pose is very chic and sexy! But the photo itself is very grainy! The background and the dress is good too! But since you did not turn in your "Freestyle" photo it will be a call out penalty!

 

Allison- www.flickr.com/photos/84271682@N06/8460945599/:

 

Mr. Bratz: What a huge step up! This is stunning! Your pose could use a little work though! The editing is amazing and overall good job!

 

Miku: Honestly, not your best. The editing just covers up the flaws. When I looked behind it, I could see a really nice background but the editing just "jazzes" it up abit. Not saying I hate it but when some people edit like this, it makes me wonder if the just cover the flaws with wild effects - don't be one of them! Overall: Nice face and background but stiff pose and alot of layers.

 

Raina- www.flickr.com/photos/57541329@N03/8466024831/in/photostream:

 

Miku: Wow! You look like the queen of the com.! I like how you added elegance to a candy-lish theme! Background reminds me of cotton candy... O3o Well done!

 

Mr. Bratz: Wow! This is so amazing! You managed it to be high fashion and sassy but still maintain it as candy! The pose is very sexy also!

 

Katia- www.flickr.com/photos/66850425@N04/8447204639/:

 

Mr. Bratz: Stunning! I love how you went all nude! Your pose is stunning and that face is just gorgeous! BUT, I feel this is really soft! The candy is there but it's really hard to see!

 

Miku: This is alright. I like how you took it outside and your take on this but this is just boring! You look very commercial and not in a good way. I also wish you would change your make-up more. This doesn't fit the theme.

 

Camilla- www.flickr.com/photos/86305693@N04/8437113106/in/photostream:

 

Miku: I like your outfit and backdrop but that''s it! I wish you fixed up your bangs, they look messy. The pose is stiff and I don't think the letters were necessary.

 

Mr. Bratz: Welcome back Camilla! First off your outfit is outrageous! Your pose is a little stiff though! The photo is abit grainy! The candy made dress is outgoing though!

 

Jizel- www.flickr.com/photos/87808124@N06/8442501786/in/photostr...:

 

Mr. Bratz: Fierce! Your pose is very sexy and straight to the point! The lollipop wrapping dress is very cute! Those eyes are stunning, I really thought they were peppermints!

  

Miku: This looks very rushed to be honest. You look like you don't want to be here and you just through lollipops on the floor, and took a picture. Try and get out of your comfort zone more!

 

Sophie- www.flickr.com/photos/glglover78/8435997111/:

 

Miku: This is quite disappointing. I like your outfit and the pose is ok but the angle and your face ruins the photo for me..... Your face looks awkward and you should've rotated it.

 

Mr. Bratz: Huge step up from last week! From innocent to fierce! Your makeup is fantastic and your pose is super fierce! Also your face is gorgeous!

 

Seirina- www.flickr.com/photos/lagoonablue247/8463022315/in/photos...:

 

Mr. Bratz: This is a big let down for me! Your pose is model 101 and very weak! The candy carpet thing was very unique and very different! But the other models arm is really catching my eye in this photo! Also the dress is nice!

 

Miku: That dress is so designer! i love it! But the rest- not much. The pose is weird and the bg is boring. The other model wasn't necessary.

 

Raine- www.flickr.com/photos/87268212@N06/8433639617/in/photostream:

 

Miku: I know you can take more risks! You look like an ordinary girl on pounds of ice cream: that's not good!

 

Mr. Bratz: This a step up from last week! Your face is gorgeous but your pose is very stiff! I will give you props for taking that risk with the Ice Cream!

 

Roxy- www.flickr.com/photos/91923902@N06/8465891715/in/photostream:

 

Mr. Bratz: This is gorgeous! Your face is stunning! Your pose is gorgeous!

 

Miku: Wow, this is ah-mazing! The calm feeling is awesome and the background is so detailed! Great job!

 

Call Out Order:

 

1. Raina

2. Winter

3. Shayla

4. Izzy and Roxy (Tie)

5. Allison

6. Seirina

7. Jaymee

8. Jizel

9. Camilla

10. Raine

11. Sophie

12. Katia Lyn

13. Tessa

 

Bottom Two: Dana and Angela

 

Dana and Angela you models are both up here for the same reason! You did not get your photos in! The model that is staying is........

 

14. Angela

 

Angela I want to give you second chance! Your portfolio was much better than Dana's so don't let me down!

 

Dana you are a model with loads of potential! This is definitely not the end of the career I can see you going far!

 

Your next theme is "Model Madness"!

 

Requirements:

 

- Must be a psychical altercation

- Must have an opponent

- Have messy hair

- Either a Club fight or a Bad Girls Club fight

- Must have a story!

- Have Fun

 

Deadline: February 26, 2013

 

Photos Finished:

Sophie: www.flickr.com/photos/glglover78/8468770505/

Jizel: www.flickr.com/photos/87808124@N06/8474779564/in/photostream

Izzy: www.flickr.com/photos/beautiful30bratz/8471365273/in/phot...

Raine: www.flickr.com/photos/87268212@N06/8476357343/in/photostream

Camilla: www.flickr.com/photos/86305693@N04/8478719533/

Allison: www.flickr.com/photos/84271682@N06/8497654815/

Angela: www.flickr.com/photos/87839448@N06/8496068320/

Katia: www.flickr.com/photos/66850425@N04/8485952923/

Raine: www.flickr.com/photos/87268212@N06/8476357343/in/photostr...

Jaymee: www.flickr.com/photos/86834980@N07/8501045877/

Roxy: www.flickr.com/photos/91923902@N06/8508977108/in/photostream

Shayne: www.flickr.com/photos/lagoonablue247/8520240349/in/photos...

Macela or Marcela Anthemis nobilis aka Chamaemelum nobile commonly known as Roman chamomile, at the Farmer's Market in Funchal.

 

Marcela is a false chamomile, very similar to the genuine Matricaria chamomilla / Matricaria recutita with similar medicinal properties: antiseptic, antibiotic, disinfectant, bactericidal and vermifuge.

 

Fresh or dried, the heads of the flower are traditionally used as a herbal infusion, very popular for boosting the immune system, anti‐spasmodic cough treatment, fever and cold remedy, digestive stimulant, stomach ache relief, a calming agent to help sleep as well as being used to soothe skin rashes.