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LOOK KG 243 racer from late 1990's built with Columbus Neuron steel. Components are generally 2000's - but a mix of new and old.
Photo: Thomas Ohlsson Photography
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Nearly everyone has had headache pain, and most of us have had it many times. A minor headache is little more than a nuisance that's relieved by an over-the-counter pain reliever, some food or coffee, or a short rest. But if your headache is severe or unusual, you might worry about stroke, a tumor, or a blood clot. Fortunately, such problems are rare. Still, you should know when a headache needs urgent care and how to control the vast majority of headaches that are not threatening to your health. Headache is defined as a pain arising from the head or upper neck of the body. The pain originates from the tissues and structures that surround the skull or the brain because the brain itself has no nerves that give rise to the sensation of pain (pain fibers). The thin layer of tissue (periosteum) that surrounds bones, muscles that encase the skull, sinuses, eyes, and ears, as well as thin tissues that cover the surface of the brain and spinal cord (meninges), arteries, veins, and nerves, all can become inflamed or irritated and cause headache. The pain may be a dull ache, sharp, throbbing, constant, intermittent, mild, or intense. Headaches can be more complicated than most people realize. Different kinds can have their own set of symptoms, happen for unique reasons, and need different kinds of treatment. Once you know the type of headache you have, you and your doctor can find the treatment that’s most likely to help and even try to prevent them.
Headache is the symptom of pain anywhere in the region of the head or neck. It occurs in migraines (sharp, or throbbing pains), tension-type headaches, and cluster headaches.Frequent headaches can affect relationships and employment. There is also an increased risk of depression in those with severe headaches. Headaches can occur as a result of many conditions whether serious or not. There are a number of different classification systems for headaches. The most well-recognized is that of the International Headache Society. Causes of headaches may include fatigue, sleep deprivation, stress, the effects of medications, the effects of recreational drugs, viral infections, loud noises, common colds, head injury, rapid ingestion of a very cold food or beverage, and dental or sinus issues.The pain you feel during a headache comes from a mix of signals between your brain, blood vessels, and nearby nerves. Specific nerves of the blood vessels and head muscles switch on and send pain signals to your brain. But it's not clear why these signals turn on in the first place. People often get headaches because of:
Illness: such as an infection, cold, or fever. They’re also common with conditions like sinusitis (inflammation of the sinuses), a throat infection, or an ear infection. In some cases, the headaches may be the result of a blow to the head or rarely, a sign of a more serious medical problem. Stress: Emotional stress and depression as well as alcohol use, skipping meals, changes in sleep patterns, and taking too much medication. Other causes include eyestrain and neck or back strain due to poor posture. Your environment, including secondhand tobacco smoke, strong smells from household chemicals or perfumes, allergens, and certain foods. Stress, pollution, noise, lighting, and weather changes are other possible triggers. Headaches, especially migraine headaches, tend to run in families. Most children and teens (90%) who have migraines have other family members who get them. When both parents have a history of migraines, there is a 70% chance that their child will also have them. If only one parent has a history of these headaches, the risk drops to 25%-50%.
Doctors don’t know exactly what causes migraines. A popular theory is that triggers cause unusual brain activity, which causes changes in the blood vessels there. Some forms of migraines are linked to genetic problems in certain parts of the brain. Too much physical activity can also trigger a migraine in adults. Treatment of a headache depends on the underlying cause, but commonly involves pain medication. Some form of headache is one of the most commonly experienced of all physical discomforts. About half of adults have a headache in a given year. Tension headaches are the most common, affecting about 1.6 billion people (21.8% of the population) followed by migraine headaches which affect about 848 million (11.7%)
There are more than two hundred types of headaches. Some are harmless and some are life-threatening. The description of the headache and findings on neurological examination, determine whether additional tests are needed and what treatment is best. Once you get your headaches diagnosed correctly, you can start the right treatment plan for your symptoms. The first step is to talk to your doctor about your headaches. She’ll give you a physical exam and ask you about the symptoms you have and how often they happen. It’s important to be as complete as possible with these descriptions. Give your doctor a list of things that cause your headaches, make them worse, and what helps you feel better. You can track details in a headache diary to help your doctor diagnose your problem. Most people don’t need special diagnostic tests. But sometimes, doctors suggest a CT scan or MRI to look for problems inside your brain that might cause your headaches. Skull X-rays are not helpful. An EEG (electroencephalogram) is also unnecessary unless you have passed out when you had a headache. If your headache symptoms get worse or happen more often despite treatment, ask your doctor to refer you to a headache specialist. If you need more information, contact one of the organizations in the resource list for a list of member doctors in your state.
Your doctor may recommend different types of treatment to try. She also might recommend more testing or refer you to a headache specialist. The treatment you need will depend on a lot of things, including the type of headache you get, how often, and its cause. Some people don’t need medical help at all. But those who do might get medications, counseling, stress management, and biofeedback. Your doctor will make a treatment plan to meet your specific needs. Once you start a treatment program, keep track of how well it’s working. A headache diary can help you note any patterns or changes in how you feel. Know that it may take some time for you and your doctor to find the best treatment plan, so try to be patient. Be honest with her about what is and isn’t working for you. Even though you’re getting treatment, you should still steer clear of the things you know can trigger your problem, like foods or smells. And it’s important to stick to healthy habits that will keep you feeling good, like regular exercise, enough sleep, and a healthy diet. Also, make your scheduled follow-up appointments so your doctor can see how you’re doing and make changes in the treatment program if you need them.
Headaches are broadly classified as "primary" or "secondary". Primary headaches are benign, recurrent headaches not caused by underlying disease or structural problems. For example, migraine is a type of primary headache. While primary headaches may cause significant daily pain and disability, they are not dangerous. Secondary headaches are caused by an underlying disease, like an infection, head injury, vascular disorders, brain bleed or tumors. Secondary headaches can be harmless or dangerous. Certain "red flags" or warning signs indicate a secondary headache may be dangerous.Occurring in about three of every four adults, tension headaches are the most common of all headaches. In most cases, they are mild to moderate in severity and occur infrequently. But a few people get severe tension headaches, and some are troubled by them for three or four times a week. The typical tension headache produces a dull, squeezing pain on both sides of the head. People with strong tension headaches may feel like their head is in a vise. The shoulders and neck can also ache. Some tension headaches are triggered by fatigue, emotional stress, or problems involving the muscles or joints of the neck or jaw. Most last for 20 minutes to two hours.If you get occasional tension-type headaches, you can take care of them yourself. Over-the-counter pain relievers such as acetaminophen (Tylenol, other brands) and nonsteroidal anti-inflammatories (NSAIDs) such as aspirin, naproxen (Aleve, other brands), or ibuprofen (Motrin, Advil, other brands) often do the trick, but follow the directions on the label, and never take more than you should. A heating pad or warm shower may help; some people feel better with a short nap or light snack. If you get frequent tension-type headaches, try to identify triggers so you can avoid them. Don't get overtired or skip meals. Learn relaxation techniques; yoga is particularly helpful because it can relax both your mind and your neck muscles. If you clench your jaw or grind your teeth at night, a bite plate may help. If you need more help, your doctor may prescribe a stronger pain medication or a muscle relaxant to control headache pain. Many people with recurrent tension-type headaches can prevent attacks by taking a tricyclic antidepressant such as amitriptyline (Elavil, generic). Fortunately, most people with tension-type headaches will do very well with simpler programs. 90% of all headaches are primary headaches. Primary headaches usually first start when people are between 20 and 40 years old. The most common types of primary headaches are migraines and tension-type headaches.[6] They have different characteristics. Migraines typically present with pulsing head pain, nausea, photophobia (sensitivity to light) and phonophobia (sensitivity to sound). Tension-type headaches usually present with non-pulsing "bandlike" pressure on both sides of the head, not accompanied by other symptoms. Other very rare types of primary headaches include: cluster headaches: This type is intense and feels like a burning or piercing pain behind or around one eye, either throbbing or constant. It’s the least common but the most severe type of headache. The pain can be so bad that most people with cluster headaches can’t sit still and will often pace during an attack. On the side of the pain, the eyelid droops, the eye reddens, pupil gets smaller or the eye tears. The nostril on that side runs or stuffs
They’re called “cluster headaches” because they tend to happen in groups. You might get them one to three times per day during a cluster period, which may last 2 weeks to 3 months. Each headache attack last 15 mins to 3 hours and often wakens the patient from sleep. The headaches may disappear completely (go into "remission") for months or years, only to come back again. Cluster headaches affect men 3-4 times more often than women.short episodes (15–180 minutes) of severe pain, usually around one eye, with autonomic symptoms (tearing, red eye, nasal congestion) which occur at the same time every day. Cluster headaches can be treated with triptans and prevented with prednisone, ergotamine or lithium. trigeminal neuralgia or occipital neuralgia: shooting face pain hemicrania continua: continuous unilateral pain with episodes of severe pain. Hemicrania continua can be relieved by the medication indomethacin.
primary stabbing headache: recurrent episodes of stabbing "ice pick pain" or "jabs and jolts" for 1 second to several minutes without autonomic symptoms (tearing, red eye, nasal congestion). These headaches can be treated with indomethacin. primary cough headache: starts suddenly and lasts for several minutes after coughing, sneezing or straining (anything that may increase pressure in the head). Serious causes (see secondary headaches red flag section) must be ruled out before a diagnosis of "benign" primary cough headache can be made. primary exertional headache: throbbing, pulsatile pain which starts during or after exercising, lasting for 5 minutes to 24 hours. The mechanism behind these headaches is unclear, possibly due to straining causing veins in the head to dilate, causing pain. These headaches can be prevented by not exercising too strenuously and can be treated with medications such as indomethacin. primary sex headache: dull, bilateral headache that starts during sexual activity and becomes much worse during orgasm. These headaches are thought to be due to lower pressure in the head during sex. It is important to realize that headaches that begin during orgasm may be due to a subarachnoid hemorrhage, so serious causes must be ruled out first. These headaches are treated by advising the person to stop sex if they develop a headache. Medications such as propranolol and diltiazem can also be helpful.
hypnic headache: moderate-severe headache that starts a few hours after falling asleep and lasts 15–30 minutes. The headache may recur several times during night. Hypnic headaches are usually in older women. They may be treated with lithium.
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Headaches may be caused by problems elsewhere in the head or neck. Some of these are not harmful, such as cervicogenic headache (pain arising from the neck muscles). Medication overuse headache may occur in those using excessive painkillers for headaches, paradoxically causing worsening headaches.More serious causes of secondary headaches include: meningitis: inflammation of the meninges which presents with fever and meningismus, or stiff neck
bleeding inside the brain (intracranial hemorrhage)
subarachnoid hemorrhage (acute, severe headache, stiff neck WITHOUT fever) ruptured aneurysm, arteriovenous malformation, intraparenchymal hemorrhage (headache only)
brain tumor: dull headache, worse with exertion and change in position, accompanied by nausea and vomiting. Often, the person will have nausea and vomiting for weeks before the headache starts. temporal arteritis: inflammatory disease of arteries common in the elderly (average age 70) with fever, headache, weight loss, jaw claudication, tender vessels by the temples, polymyalgia rheumatica acute closed angle glaucoma (increased pressure in the eyeball): headache that starts with eye pain, blurry vision, associated with nausea and vomiting. On physical exam, the person will have a red eye and a fixed, mid dilated pupil. Post-ictal headaches: Headaches that happen after a convulsion or other type of seizure, as part of the period after the seizure (the post-ictal state) Gastrointestinal disorders may cause headaches, including Helicobacter pylori infection, celiac disease, non-celiac gluten sensitivity, irritable bowel syndrome, inflammatory bowel disease, gastroparesis, and hepatobiliary disorders. The treatment of the gastrointestinal disorders may lead to a remission or improvement of headaches.
The brain itself is not sensitive to pain, because it lacks pain receptors. However, several areas of the head and neck do have pain receptors and can thus sense pain. These include the extracranial arteries, middle meningeal artery, large veins, venous sinuses, cranial and spinal nerves, head and neck muscles, the meninges, falx cerebri, parts of the brainstem, eyes, ears, teeth and lining of the mouth.Pial arteries, rather than pial veins are responsible for pain production. Headaches often result from traction to or irritation of the meninges and blood vessels. The nociceptors may be stimulated by head trauma or tumors and cause headaches. Blood vessel spasms, dilated blood vessels, inflammation or infection of meninges and muscular tension can also stimulate nociceptors and cause pain. Once stimulated, a nociceptor sends a message up the length of the nerve fiber to the nerve cells in the brain, signaling that a part of the body hurts.
Primary headaches are more difficult to understand than secondary headaches. The exact mechanisms which cause migraines, tension headaches and cluster headaches are not known. There have been different theories over time which attempt to explain what happens in the brain to cause these headaches.
Migraines are currently thought to be caused by dysfunction of the nerves in the brain. This condition is accompanied by intense headaches. These headaches are often described as pounding, throbbing pain. They can last from 4 hours to 3 days and usually happen one to four times per month. Along with the pain, people have other symptoms, such as sensitivity to light, noise, or smells; nausea or vomiting; loss of appetite; and upset stomach or belly pain. When a child has a migraine, she may look pale, feel dizzy, and have blurry vision, fever, and an upset stomach.Migraines occur less often than tension-type headaches, but they are usually much more severe. They are two to three times more common in women than men, but that's small consolation if you are among the 6% to 8% of all men who have migraines. And since a Harvard study of 20,084 men age 40 to 84 reported that having migraines boosts the risk of heart attacks by 42%, men with migraines should take their headaches to heart. Neurologists believe that migraines are caused by changes in the brain's blood flow and nerve cell activity. Genetics play a role since 70% of migraine victims have at least one close relative with the problem. Migraine triggers. Although a migraine can come on without warning, it is often set off by a trigger. The things that set off a migraine vary from person to person, but a migraine sufferer usually remains sensitive to the same triggers. A small percentage of children's migraines include digestive symptoms, like vomiting, that happen about once a month. Previously, migraines were thought to be caused by a primary problem with the blood vessels in the brain.This vascular theory, which was developed in the 20th century by Wolff, suggested that the aura in migraines is caused by constriction of intracranial vessels (vessels inside the brain), and the headache itself is caused by rebound dilation of extracranial vessels (vessels just outside the brain). Dilation of these extracranial blood vessels activates the pain receptors in the surrounding nerves, causing a headache. The vascular theory is no longer accepted. Studies have shown migraine head pain is not accompanied by extracranial vasodilation, but rather only has some mild intracranial vasodilation.
Currently, most specialists think migraines are due to a primary problem with the nerves in the brain. Auras are thought to be caused by a wave of increased activity of neurons in the cerebral cortex (a part of the brain) known as cortical spreading depression followed by a period of depressed activity. Some people think headaches are caused by the activation of sensory nerves which release peptides or serotonin, causing inflammation in arteries, dura and meninges and also cause some vasodilation. Triptans, medications which treat migraines, block serotonin receptors and constrict blood vessels. People who are more susceptible to experience migraines without headache are those who have a family history of migraines, women, and women who are experiencing hormonal changes or are taking birth control pills or are prescribed hormone replacement therapy. Tension headaches are thought to be caused by activation of peripheral nerves in the head and neck muscles Cluster headaches involve overactivation of the trigeminal nerve and hypothalamus in the brain, but the exact cause is unknown.
Edit: Hurray for the GFP Nobel Prize. Aside from just green, it is a wonderful rainbow of tools providing results...
20X magnification of the somatosensory cortex of a mouse brain slice. These little guys have green flourescent protein (GFP) from a jelly-fish expressed in a subset of their neurons. Layer V neuron cell bodies are the teardrop shaped things at the bottom and then the dendrite reaches up like a tree to then bifurcate near the top (pial surface).
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De forma misteriosa y por ello todavía incomprendida, las amebas constructoras, que como Centropyxis modelan granito a grano su caparazón, sin planos, sin neuronas y sin manos, lo hacen siguiendo siempre el mismo patrón no escrito y ese patrón permite diferenciar a los numerosos géneros y a la gran variedad de especies que fabrican su casa siguiendo técnicas completamente distintas, siempre con un resultado sorprendente y hermoso del Arte de la Naturaleza.
Centropyxis es un género que reúne a poco más de una docena de especies, de contorno variado, pero casi siempre elíptico o circular, cuya cubierta está tapizada por diminutos granitos de arena o caparazones minúsculos de algunos organismos que como las diatomeas, tras vivir navegando un tiempo, han quedado depositados sobre el mullido fondo en una colección de joyas de naufragio que Centropyxis consigue recuperar para adornarse.
A veces Centropyxis se acicala rematando su casa con pequeñas torres de aguja que coronan sus contornos y cada una de las especies lo hace de una manera propia y singular. Sin embargo, todas tienen algo en común: la puerta por la que Centropyxis asoma su cuerpo al agua, como si fuese la puerta de una concha de caracol, suele ser circular como un ojo de buey y está situada en posición central.
...sin embargo, alguna de estas diminutas amebas, excéntrica y original, ha decidido probar suerte de una manera diferente y construir su casa con la puerta desplazada hacia un extremo y asomar así su cuerpo por ella como si lo hiciese desde la boca de un buzón y esa ameba excéntrica es la ameba de hoy Centropyxis platystoma.
Al igual que al resto de sus hermanas a Centropyxis platystoma también le encanta rebozarse de arena y si fuésemos de su tamaño, la confundiríamos con el fondo de las charcas en las que vive camuflada como si fuese el mismo lecho del agua.
Todo lo que encuentra en el fondo le sirve para ir construyendo, grano a grano, la casa que le dará cobijo y, así, de forma mágica, cristal a cristal de cuarzo fragmentos invisibles de limo van modelando la vasija que contiene su vida.
Centropyxis platystoma también es una ameba de gruesos brazos y cuerpo de agua, por eso necesita vivir protegida y es ella misma la que fabrica una casa con pared de doble muro: uno fino y suave, casi transparente, de materia orgánica en contacto con su cuerpo como una delicada camisa y otro sobre ella, armadura y abrigo de piedrecitas recogidas en el fondo.
Sin embargo, Centropyxis platystoma es excéntrica y construye a su manera especial la entrada de su casa, protegida además por encima por un arco en forma de abanico extendido, desde donde se asoma para ver la vida a su alrededor, ver sin vista...eso sí que es original y excéntrico y no sólo es habilidad de esta ameba excéntrica, todas ellas ven así.
Centropyxis platystoma vive entre los sedimentos alimentándose de pequeñas partículas de la materia orgánica contenida en ellos y se cita por vez primera desde esta galería para el Lago de Sanabria y quizá también para la Península Ibérica.
La imagen, tomada a 400 aumentos con la técnica de campo oscuro y polarización, procede de una muestra recogida a 4m de profundidad, en los fondos del Lago de Sanabria junto a la Isla de Moras el 7 de julio de 2015, por Laura, Mª José y Tomás desde el catamarán Helios Sanabria el primer catamarán del mundo propulsado por energía eólica y solar.
Presentación ponencia congreso internacional de Limnología de la AIL
Informes de contaminación en el Lago de Sanabria
Informe de evolución de la contaminación en el Lago de Sanabria
Nation of China systematically organizes itself to operate just like a brain, with each individual acting as a neuron (forming what has come to be called a "Blockhead")Chinese thought, including seemingly disparate fields such as geomancy or Feng shui, astrology, traditional Chinese medicin, as seen on "Floating Perspective," a technique which displaces the static eye of the viewer and highlights the differences between Chinese and Western modes of spatial representation. It summarizes these into three ways of minor, middle and great achievement, and illustrates each with charts, explanations and formulae..The 5-volumed Record of the Realization of Perfection by the Concourse of Immortals of West Mountain ( 《西山群仙會真記》 Xishan Qunxian Huizhen Ji ) was authored by Shi Jianwu and compiled by Li Song. Shi, whose title was "The Perfect Man of Huayang" ( 華陽真人 Huayang Zhenren ) lived during the Tang Dynasty. After his success in the national civil service examinations, Shi remained secluded as a Daoist on the West Mountain (present Jiangxi province) to cultivate the Dao. But some say that there were two men named "Shi Jianwu". the Comprehensive Annotated Bibliography of the Four Repositories ( 《四庫提要》 Siku Tiyao ) say some Daoists, under the name of Shi, wrote this book during the Jin and Yuan Dynasties. Still some hold that the book should have been completed no later than the Northern Song. The preface by the author states, the book, in secret accordance with earlier and later sages, imitating the number of five agents ( 五行 Wuxing ) and corresponding to the pure Yang one-breath ( 純陽一氣 Chunyang Yiqi ), expounds the mystery and supreme truth of the Zhong-Lu lineage in one five-volume book. The contents, similar to the Transmission of Dao by Zhongli Chuan and Lü Dongbin ( 《鍾呂傳道集》 Zhinglu Chuandao Ji ), explains the ways of inner alchemy, citing the Supreme Hidden Book ( 《太上隱書》 Taishang Yinshu ), Record of the Western Mountain ( 《西山記》 Xishan Ji ), Numinous Treasure Book of Inner Contemplation ( 《靈寶內觀經》 Lingbao Neiguan Jing ), the Book of Communion with the Mystery ( 《通玄經》 Tongxuan Jing ) and quotations of the immortals Ge, Yin and Lu. The theme, based on Three Ways Unified and Normalized ( 《參同契》 Cantong Qi ), expounds the theory about increasing and reducing fire ( 抽添 Choutian ) and the practice that leads to liberation.
en.daoinfo.org/wiki/Record_of_the_Realization_of_Perfecti...
Neuronal cells were cultured in a microfluidic device with channels to induce guidance of axons. We load the device with nanorods which penetrate into the cells and we study how those rods move inside the axons. Cells have been fixed and plastified with resin (thin layer plastification, procedure developed in our lab) such that both the rods and the cells are preserved and visible. In fact we can distinguish between the penetrating rods and those which just stay outside the cell.
Courtesy of Dr. Francesca Santoro , Stanford University - Chemistry Department
Image Details
Instrument used: Helios NanoLab
Voltage: 5kV
Detector: BSE
Close-up of neurons in a mouse with the neurodegenerative disease Niemann-Pick type C1. A major way to assess the impact of a potential therapeutic on the central nervous system is to assess cerebellar pathology in mice.
Credit: I. Williams, National Institute of Child Health and Human Development, NIH
At the UCSF Decoding the Brain Academy last night, Dr. Tomasz Nowakowski plotted the progress of neurons sequenced over time, including the project planned for 2025. It has been following a Moore’s Law-like exponential curve for a decade now. So, we should have a sequence of every one of the 86 billion neurons in a human brain by 2032, and maybe all the glial cells too.
Why sequence every cell? The genetic makeup varies, as does the methylation. On the left, you can see clustering analysis of 121 different cell types in the thalamus alone. Out neurons are very different, and they vary over time. I was reminded of an amazing discovery Ed Boyden of MIT shared with me — they found HIV-like encodings being expressed in human neurons. This might be a transposon-like viral vector for horizontal gene transfer in the brain. This is a controversial finding, partially because it is difficult to detect the signal from the noise of the delta from the human reference genome, which is still Craig Venter. I asked Ed how many neuron types does he suspect we’ll find? “An infinite number. They are all different.”
When we asked Nowakowski about the compute capacity of a neuron, he lit up with excitement. By analogy to our machine learning neural nets with back prop, we now know that our neurons don’t just adjust weights at the synapse. Firing-feedback adjusts the weights in all of the ~1000 inputs embedded in the dendrite of each neuron. This is called synaptic tagging, and it serves as an overlay to the relaxation back to a nominal rate of firing, a process that is not fully understood.
From the other speakers on stage, left to right:
• Shawn Hervey-Jumper: in 50 years of neurosurgery advances, we have added just 4 months to expected lifespan
• Mercedes Paredes: in the pre-natal and infant brain (up to 6 months), neurons migrate great distances (1-10cm) by sending out an axon and pulling the neuron cell body along, a sequence of push and pulls. For a sense of scale, if the neuron was a car, it is like driving across America. How do they navigate over these distances?
• Christine Liu: We can keep brain tissues alive for weeks now (for glass probe insertion into neural cell bodies). Learning how to juggle can increase cortical thickness by 3%.
“I can never read all the books I want; I can never be all the people I want and live all the lives I want....I am horribly limited.”
― (Sylvia Plath) ―
When you spend the day trying to write, and the words don't come: the neurons start melting.
+++ DISCLAIMER +++
Nothing you see here is real, even though the conversion or the presented background story might be based on historical facts. BEWARE!
Some background:
The McDonnell Douglas (now Boeing) T-45 Goshawk was a highly modified version of the BAe Hawk land-based training jet aircraft. Manufactured by McDonnell Douglas (now Boeing) and British Aerospace (now BAe Systems), the T-45 was used by the United States Navy and the United States Marine Corps (USMC) as an aircraft carrier-capable trainer.
The Goshawk's origins began in the mid-1970s, when the US Navy began looking for a single aircraft replacement for both its T-2 and TA-4 jet trainers. The US Navy started the VTXTS advanced trainer program in 1978. Several companies made submissions, e. g. North American or Northrop/Vought. Due to the size of the potential contract, European companies made submissions, too, including a navalized Alpha Jet from Dassault/Dornier and a fully carrier-capable version of the BAe Hawk Mk.60, mutually proposed by British Aerospace (BAe) and McDonnell Douglas (MDC). The latter eventually won the competition and BAe and MDC were awarded the T-45 contract in 1981.
The Hawk had not been designed for carrier operations and numerous modifications were required to make it suitable for use on carriers. These included improvements to the low-speed handling characteristics and a reduction in the approach speed. It was found that the aircraft was apt to stall at the low approach speed required. Modifications were designed by BAe in England; most notably a simple slat system was devised, operated by an actuator and linkage mechanism to fit into the small space available. Strakes were also added on the fuselage to improve airflow. Other changes were a strengthened airframe, a more robust and wider landing gear with a two-wheel nose landing gear, a catapult tow bar attachment and an arresting hook. The modified aircraft was christened “Goshawk”, flew in 1988 for the first time and became operational in 1991.
Beyond being a naval trainer the T-45 was also adapted for first-line duty with strike capabilities, in the form of the OA-45 for the USMC. The role of this aircraft dated back to the Vietnam War when twenty-three A-4 two-seaters were converted into OA-4Ms for “FastFAC” (Fast Forward Air Controller) missions, in order to control interdiction sorties dedicated to shaping the battlefield for future operations. Basically, the OA-4M was a TA-4F equipped with A-4M electronics. The most visible and characteristic change was the fitting of the A-4M’s dorsal electronics hump, neatly faired into the rear of the two-seat canopy. The nose sensor group of the OA-4M was basically the same as that of the A-4M, but the Angle/Rate Bombing system was not installed as it would not be needed.
When the T-45 was introduced in the early Nineties, the USMCs OA-4Ms had reached the end of their service life and the USMC started looking for a replacement, wanting a comparable, light and fast fixed-wing aircraft. The USMC did not accept the LTV A-7 as an A-4 replacement (even though a two-seater version was available), because it was already dated, too, and not part of the USMC inventory. The USMC's A-4Ms were supposed to be replaced by the VTOL AV-8 by the mid-nineties, but the AV-8, even as a two-seater, was deemed unsuitable for FFAC duties. The new T-45 looked like a good and economical alternative with future potential, since the airframe was brand new and the type's infrastructure was fully established, so that a small number of specialized aircraft could easily be supported without much extra cost.
With fresh experience from the 1st Gulf War in 1990-91 the decision was made to buy 25 extra T-45A airframes and convert them to OA-45A standard. Most important change were modified wings, using structures and systems from the BAe Hawk 100 series. While the T-45 only had two underwing and a single ventral hardpoint, the OA-45A featured a total of seven: four underwing and one ventral hardpoints, plus wingtip stations for defensive air-to-air missiles. Upgraded avionics allowed the deployment of a wide range of external stores, including air-to-ground missiles and rocket launchers, a reconnaissance pod, retarded and free-fall bombs of up to 1,000 pounds (450 kg) caliber, runway cratering, anti-personnel and light armor bombs, cluster bombs, practice bombs as well as external fuel tanks and ECM pods. This was a vital asset, since Desert Storm had proved that FFAC aircraft had to have an offensive capability to handle targets of opportunity on their own, when no air assets to control were available. A total ordnance load of up to 6,800 lb (3,085 kg) was possible, even though the aircraft was not supposed to play an offensive role and rather act from a distance, relying on its small size and agility.
Communication modifications for the FastFAC role included a KY-28 secure voice system, an ARC-159 radio and an ARC-114 VHF radio. Similar to the Skyhawk, a hump behind the cockpit had to be added to make room for the additional electronic equipment and a heat exchanger. Other additions were a continuous-wave Doppler navigation radar under a shallow ventral radome underneath the cockpit, a ground control bombing system, an APN-194 altimeter, an ALR-45 radar warning suite, a retrofitted, fixed midair refueling probe and cockpit armor plating that included Kevlar linings on the floor and the lower side walls as well as externally mounted armor plates for the upper areas.
VMA-131 of Marine Aircraft Group 49 (the Diamondbacks) retired its last four OA-4Ms on 22 June 1994, and the new OA-45A arrived just in time to replace the venerable Skyhawk two-seaters in the FastFAC role. Trainer versions of the Skyhawk remained in Navy service, however, finding a new lease on life with the advent of "adversary training". OA-45A deliveries were finished in 1996 and the 25 aircraft were distributed among the newly established Marine Aviation Logistics Squadron (MALS, formerly Headquarters & Maintenance Squadron/H&MS) 12 & 13. The USMC crews soon nicknamed their new mounts "GosHog", to underlöine ist offensive capabilities and to set themselves apart from the USN's "tame" trainers. Even though thos name was never officially approved it caught on quickly.
After initial experience with the new aircraft and in the wake of technological advances, the USMC decided to upgrade the OA-45As in 2000 to improve its effectiveness and interaction capabilities with ground troops. This primarily resulted in the addition of a forward-looking infrared camera laser in the aircraft’s nose section, which enabled the aircraft to execute all-weather/night reconnaissance and to illuminate targets for laser-guided infantry shells or ordnance launched by the OA-45 itself or by other aircraft. Through this measure the OA-45 became capable of carrying and independently deploying light laser-guided smart weapons like the GBU-12 and -16 “Paveway II” glide bombs or the laser-guided AGM-65E “Maverick” variant. The update was gradually executed during regular overhauls in the course of 2001 and 2002 (no new airframes were built/converted), the modified machines received the new designation OA-45B.
After this update phase, the OA-45Bs were deployed in several global conflicts and saw frequent use in the following years. For instance, MALS 13 used its OA-45Bs operationally for the first time in October 2002 when the squadron was tasked with providing support to six AV-8B Harrier aircraft in combat operations in Afghanistan during Operation Enduring Freedom. This mission lasted until October 2003, four aircraft were allocated and one OA-45B was lost during a landing accident.
On 15 January 2003, MALS 13 embarked 205 Marines and equipment aboard the USS Bonhomme Richard in support of combat operations in Southwest Asia during Operation Southern Watch. Four OA-45Bs successfully supported these troops from land bases, marking targets and flying reconnaissance missions.
Furthermore, six MALS 13 OA-45Bs took actively part in Operation Iraqi Freedom from Al Jaber Air Base, Kuwait, and An Numiniyah Expeditionary Air Field, Iraq, where the aircraft worked closely together with the advancing ground troops of the USMC’s 15th Marine Expeditionary Unit. They successfully illuminated targets for US Navy fighter bombers, which were launched from USS Abraham Lincoln (CVN-72) in the Persian Gulf, and effectively guided these aircraft to their targets. Two OA-45Bs were lost during this conflict, one through enemy MANPADS, the other through friendly AA fire. In late May 2003 the surviving machines and their crews returned to MCAS Yuma.
On 16 March 2007, the 200th T-45 airframe was delivered to the US Navy. From this final batch, six airframes were set aside and modified into OA-45Bs in order to fill the losses over the past years.
Later T-45 production aircraft were built with enhanced avionics systems for a heads-up display (HUD) and glass cockpit standard, while all extant T-45A aircraft were eventually converted to a T-45C configuration under the T-45 Required Avionics Modernization Program (T-45 RAMP), bringing all aircraft to same HUD plus glass cockpit standard. These updates, esp. concerning the cockpit, were introduced to the OA-45Bs, too, and they were re-designated again, now becoming OA-45Cs, to reflect the commonality with the Navy’s Goshawk trainers. Again, these modifications were gradually introduced in the course of the OA-45s’ normal maintenance program.
In 2007, an engine update of the whole T-45 fleet, including the OA-45s, with the Adour F405-RR-402 was considered. This new engine was based on the British Adour Mk 951, designed for the latest versions of the BAe Hawk and powering the BAe Taranis and Dassault nEUROn UCAV technology demonstrators. The Adour Mk 951 offered 6,500 lbf (29 kN) thrust and up to twice the service life of the F405-RR-401. It featured an all-new fan and combustor, revised HP and LP turbines, and introduced Full Authority Digital Engine Control (FADEC). The Mk 951 was certified in 2005, the F405-RR-402 derived from it was certified in 2008, but it did not enter service due to funding issues, so that this upgrade was not carried out.
The final delivery of the 246th T-45 airframe took place in November 2009, and both T-45 and the OA-45 "GosHog" are supposed to remain in service until 2035.
General characteristics:
Crew: 2 (pilot, observer)
Length: 39 ft 4 in (11.99 m)
Wingspan: 30 ft 10 in (9.39 m)
Height: 13 ft 5 in (4.08 m)
Wing area: 190.1 ft² (17.7 m²)
Empty weight: 10,403 lb (4,460 kg)
Max. takeoff weight: 14,081 lb (6,387 kg)
Powerplant:
1× Rolls-Royce Turbomeca F405-RR-401 (Adour) non-afterburning turbofan with 5,527 lbf (26 kN)
Performance:
Maximum speed: Mach 2 (2,204 km/h (1,190 kn; 1,370 mph) at high altitude
Combat radius: 800 km (497 mi, 432 nmi)
Ferry range: 3,200 km (1,983 mi) with drop tanks
Service ceiling: 15,240 m (50,000 ft)
Wing loading: 283 kg/m² (58 lb/ft²)
Thrust/weight: 0.97
Maximum g-load: +9 g
Armament:
No internal gun; seven external hardpoints (three on each wing and one under fuselage)
for a wide range of ordnance of up to 6,800 lb (3,085 kg), including up to six AIM-9 Sidewinder for
self-defense, pods with unguided rockets for target marking or ECM pods, but also offensive weapons
of up to 1.000 lb (454 kg) weight, including iron/cluster bombs and guided AGM-65, GBU-12 and -16.
The kit and its assembly:
This fictional T-45 variant is actually the result of a long idea evolution, and simply rooted in the idea of a dedicated OA-4M replacement for the USMC; in real life, the FFAC role has been transferred to F-18 two-seaters, though, but the T-45 appeared like a sound alternative to me.
There's only one T-45 kit available, a dubious T-45A from Italeri with poor wings and stabilizers. Wolfpack also offers a T-45, but it’s just a re-boxing of the Italeri kit with some PE parts and a price tag twice as big – but it does not mend the original kit’s issues… After reading the A-4 Skyhawk book from the French "Planes & Pilots" series, I was reminded of the USMC's special OA-4M FAC two-seaters (and the fact that it is available in kit form from Italeri and Hasegawa), and, cross-checking the real-world timeline of the T-45, I found that it could have been a suitable successor. The ide of the USMC’s OA-45 was born! :D
Building-wise the Italeri T-45 remained close to OOB, even though I transplanted several parts from an Italeri BAe Hawk Mk. 100 to create a different look. I modified the nose with the Mk. 100’s laser fairing and added some radar warning sensor bumps. This transplantation was not as easy as it might seem because the T-45’s nose is, due to the different and more massive front landing gear quite different from the Hawk’s. Took some major PSR to integrate the laser nose.
An ALR-45 “hot dog” fairing from a late A-4M (Italeri kit) was added to the fin, together with a small styrene wedge extending the fin’s leading edge. This small detail markedly changes the aircraft’s look. I furthermore added a refueling probe, scratched from coated wire and some white glue, as well as a low “camel back” fairing behind the cockpit, created from a streamlined bomb half with air outlets for an integrated heat exchanger. Blade antennae were relocated and added. A shallow bump for the Doppler radar was added under the fuselage behind the landing gear well – left over from an Airfix A-4B (from an Argentinian A-4P, to be correct, actually a dorsal fairing).
On the wings, a tailored pair of pylons and wing tip launch rails from the Italeri BAe Hawk Mk. 100 kit were added, too, as well as the donor kit’s pair of Sidewinders. The rest of the ordnance consists of drop tanks and LAU-19 pods for target marking missiles. The tanks were taken from the Hawk Mk. 100 kit, too, the rocket launchers came from an Italeri NATO aircraft weapons set. The centerline position carries an ALQ-131 ECM pod from a Hasegawa US aircraft weapons set on a pylon from the scrap box.
Painting and markings:
The low-viz idea prevailed, since I had some leftover OA-4M decals from Italeri kits in store, as well as some other suitable low-viz decals from a Revell A-4F kit. However, an all-grey livery was IMHO not enough, and when I came across a picture of a USN low-viz A-7E with an improvised desert camouflage in sand and reddish brown applied over the grey (even partly extending over its markings) from Operation Iraqi Freedom, I had that extra twist that would set the OA-45 apart. MALS-13 was chosen as operator because I had matching codes, and, as another benefit, the unit had actually been deployed overseas during the 2003 Iraq War, so that the whif’’s time frame was easily settled, adding to its credibility.
The livery was built up just like on the real aircraft: on top of a basic scheme in FS 36320 and 36375 (Humbrol 128 and 127) with a slightly darker anti-glare panel in front of the cockpit (FS 35237, I used Revell 57 as a slightly paler alternative) I applied the low-viz marking decals, which were protected with a coat of acrylic varnish. Next, additional desert camouflage was added with dry-brushed sand and millitary brown (supposedly FS 33711 and 30400 in real life, I used, after consulting pictures of aircraft from both Gulf Wars, Humbrol 103 (Cream) and 234 (Dark Flesh). They were applied with a kind of a dry-brushing technique, for a streaky and worn look, leaving out the codes and other markings. The pattern itself was inspired by an USMC OV-10 Bronco in desert camouflage from the 1st Gulf War.
On top of that a black ink washing was applied. Once things had thoroughly dried over night, I wet-sanded the additional desert camouflage away, carefully from front to back, so that the edges became blurred and the underlying grey became visible again.
The cockpit interior was painted in standard Dark Gull Grey (Humbrol 140), while the air intakes and the landing gear became white, the latter with red trim on the covers’ edges – just standard. Finally, the model was sealed with a coat of matt acrylic varnish (Italeri).
The upgraded T-45 is an interesting result. The add-ons suit the aircraft, which already looks sturdier than its land-based ancestor, well. The improvised desert paint scheme with the additional two-tone camouflage over the pale grey base really makes the aircraft an unusual sight, adding to its credibility.
Hardware-wise I am really happy how the added dorsal hump blends into the overall lines – in a profile view it extends the canopy’s curve and blends into the fin, much like the A-4F/M’s arrangement. And the modified fin yields a very different look, even though not much was changed. The T-45 looks much beefier now, and from certain angles really reminds of the OA-4M and sometimes even of a diminutive Su-25?
hola, penso seriamente che il neurone stia lentamente ma progressivamente prendendo le distanze dalla proprietà corporea.
Possiamo tutto nel mondo globale ma non siamo più capaci di prendere le distanze da ciò che è letale.
La parola ridotta a suono gutturale, le frasi a messaggini criptati, la vita sociale a sfruttamento.
Tutto in nome della Libertà.
Siccome sono libero e non faccio male a nessuno mi comporto come cavolo mi pare.
E no, non è proprio così, ci sono regole non scritte dove tutto è causa ed effetto, anche se non si incorre in reati, non riesco a pensare persone di 50 anni che scrivono xchè o ci vdm dp per dare appuntamenti!
Abbiamo sempre bisogno di una nuova definizione per convenzione, maschere messe per trasformarsi in quello che gli altri vogliono, recitare parti, copioni, cercare consensi, rimanere vuoti nella speranza di essere riempiti da chi si ha di fronte.
A poco a poco siamo riusciti a conquistare una condizione di stupidità eccelsa, accantonando la sincerità nei rapporti, si fa sempre più fatica a immaginare uno scambio reale nei rapporti.
E allora ci si mette in condizioni di essere filtrati da improbabili schermi colorati dove ci si mostra come gli altri vorrebbero, bombardati come siamo da informazioni più o meno attendibili, ci adeguiamo al "pensiero comune" giusto o sbagliato che sia, in cerca di approvazione.
E allora ci si trova come quel mio amico che ha regalato al nonno l'IPOD pensando bene di modernizzare un mondo che aveva bisogno di tutto tranne che di isolarsi con le cuffiette!
Ci crediamo portatori sani di vita migliore, riducendo in macerie quartieri fatti di convivialità.
Ed ecco che lo stesso lavoro viene ridotto a import export, che in poche parole significa compro fuori che costa meno e vendo da noi che incasso di più, abbandonando per strada interi stabilimenti che hanno fatto vivere, sognare, lottare intere generazioni.
E si, è stata dura ma ce l'abbiamo fatta, abbiamo il diploma di stupidità applicata.
Lo incorniciamo e mettiamo in bella vista in sala?
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Another from last Thursdays visit to Canary Wharf Winter Lights Festival, this time it's 'Neuron' by Juan Fuentes.
This for me was one of the moer interesting installations but without my tripod I've not really been able to do it justice.
Click here to see more photos from Canary Wharf : www.flickr.com/photos/darrellg/albums/72177720298516472
From Canarywharf.com, "This newly commissioned installation is inspired by the intricate network of neural connections in the human brain. The vast three-dimensional structure composed of thousands of luminous filaments that interweave and intricately connect, aims to make the incredibly complex concept of the human brain into a tangible, and beautiful art object. Each filament represents a neuron, and their interconnection symbolizes neuronal synapses, where the transmission of electrical and chemical signals take place."
© D.Godliman
LOOK KG 243 racer from late 1990's built with Columbus Neuron steel. Components are generally 2000's - but a mix of new and old.
Photo: Thomas Ohlsson Photography
www.thomasohlsson.com | 500px | Facebook | Flickr | Instagram
... sorry, I didn't note the sculptor of this one.
While we were there some kids tried to twang some of the tendrils. Security told them to stop and they wandered away.
Hormonal sentience, first described by Robert A. Freitas Jr., describes the information processing rate in plants, which are mostly based on hormones instead of neurons like in all major animals (except sponges). Plants can to some degree communicate with each other and there are even examples of one-way-communication with animals.
Acacia trees produce tannin to defend themselves when they are grazed upon by animals. The airborne scent of the tannin is picked up by other acacia trees, which then start to produce tannin themselves as a protection from the nearby animals. When attacked by caterpillars, some plants can release chemical signals to attract parasitic wasps that attack the caterpillars.
A similar phenomenon can be found not only between plants and animals, but also between fungus and animals. There exists some sort of communication between a fungus garden and workers of the leaf-cutting ant Atta sexdens rubropilosa. If the garden is fed with plants that are poisonous for the fungus, it signals this to the ants, which then will avoid fertilizing the fungus garden with any more of the poisonous plant.The Venus flytrap, during a 1- to 20-second sensitivity interval, counts two stimuli before snapping shut on its insect prey, a processing peak of 1 bit/s. Mass is 10-100 grams, so the flytrap's SQ is about +1. Plants generally take hours to respond to stimuli though, so vegetative SQs (Sentience Quotient) tend to cluster around -2.In theory even an organism with a hormonal system instead of a nervous system could be intelligent in some degree, but it would be an extremely slow brain, to say the least.And yet, at least higher plants are able to produce electrical signals, even if they do not use them in the same way animals do. František Baluška from the University of Bonn in Germany is one of the authorities on plant neurobiology.
en.wikipedia.org/wiki/Hormonal_sentience
Plants do not have a brain or neuronal network, but reactions within signalling pathways may provide a biochemical basis for learning and memory in addition to computation and problem solving.Controversially, the brain is used as a metaphor in plant intelligence to provide an integrated view of signalling.Plants respond to environmental stimuli by movement and changes in morphology. They communicate while actively competing for resources. In addition, plants accurately compute their circumstances, use sophisticated cost–benefit analysis and take tightly controlled actions to mitigate and control diverse environmental stressors. Plants are also capable of discriminating positive and negative experiences and of "learning" (registering memories) from their past experiences. Plants use this information to update their behaviour in order to survive present and future challenges of their environment.Plant physiology studies the role of signalling, communication, and behaviour to integrate data obtained at the genetic, molecular, biochemical, and cellular levels with the physiology, development, and behaviour of individual organisms, plant ecosystems, and evolution. The neurobiological view sees plants as information-processing organisms with rather complex processes of communication occurring throughout the individual plant organism. It studies how environmental information is gathered, processed, integrated and shared (sensory plant biology) to enable these adaptive and coordinated responses (plant behaviour); and how sensory perceptions and behavioural events are 'remembered' in order to allow predictions of future activities upon the basis of past experiences. Plants, it is claimed by some plant physiologists, are as sophisticated in behaviour as animals but this sophistication has been masked by the time scales of plants' response to stimuli, many orders of magnitude slower than animals'.It has been argued that although plants are capable of adaptation, it should not be called intelligence, as plant neurobiologists are relying primarily on metaphors and analogies to argue that complex responses in plants can only be produced by intelligence.[32]"A bacterium can monitor its environment and instigate developmental processes appropriate to the prevailing circumstances, but is that intelligence? Such simple adaptation behaviour might be bacterial intelligence but is clearly not animal intelligence." However, plant intelligence fits a definition of intelligence proposed by David Stenhouse in a book about evolution and animal intelligence where he described it as "adaptively variable behaviour during the lifetime of the individual".Critics of the concept have also argued that a plant cannot have goals once it is past the development stage of plantlet because, as a modular organism, each module seeks its own survival goals and the resultant whole organism behavior is not centrally controlled.[33] This view, however, necessarily accommodates the possibility that a tree is a collection of individually intelligent modules cooperating with, competing with and influencing each other, thus determining organism level behavior from the base up. The development into a larger organism whose modules must deal with different environmental conditions and challenges is not universal across plant species either, as smaller organisms might be subject to the same conditions across their bodies, at least, when the below and above ground parts are considered separately. Moreover, the claim that central control of development is completely absent from plants is readily falsified by apical dominance.Charles Darwin studied the movement of plants and in 1880 published a book The Power of Movement in Plants. In the book he concludes:It is hardly an exaggeration to say that the tip of the radicle thus endowed [..] acts like the brain of one of the lower animals; the brain being situated within the anterior end of the body, receiving impressions from the sense-organs, and directing the several movements.In philosophy, there are few studies of the implications of plant perception. Michael Marder put forth a phenomenology of plant life based on the physiology of plant perception.Paco Calvo Garzon offers a philosophical take on plant perception based on the cognitive sciences and the computational modeling of consciousness.Comparison to neurobiology:.A plant's sensory and response system has been compared to the neurobiological processes of animals. Plant neurobiology, an unfamiliar misnomer, concerns mostly the sensory adaptive behaviour of plants and plant electrophysiology. Indian scientist J. C. Bose is credited as the first person to research and talk about neurobiology of plants. Many plant scientists and neuroscientists, however, view this as inaccurate, because plants do not have neurons.The ideas behind plant neurobiology were criticised in a 2007 article published in Trends in Plant Science by Amedeo Alpi and other scientists, including such eminent plant biologists as Gerd Jürgens, Ben Scheres, and Chris Sommerville. The breadth of fields of plant science represented by these researchers reflects the fact that the vast majority of the plant science research community reject plant neurobiology. Their main arguments are that:"Plant neurobiology does not add to our understanding of plant physiology, plant cell biology or signaling".
"There is no evidence for structures such as neurons, synapses or a brain in plants".The common occurrence of plasmodesmata in plants which "poses a problem for signaling from an electrophysiological point of view" since extensive electrical coupling would preclude the need for any cell-to-cell transport of a ‘neurotransmitter-like’ compounds.The authors call for an end to "superficial analogies and questionable extrapolations" if the concept of "plant neurobiology" is to benefit the research community.There were several responses to the criticism clarifying that the term "plant neurobiology" is a metaphor and metaphors have proved useful on several previous occasions.[37][38] Plant ecophysiology describes this phenomenon.Parallels in other taxa. As described above in the case of a plant, similar mechanisms exist in a bacterial cell, a choanoflagellate, a fungal hypha, or a sponge, among the many other examples. All of these individual organisms of the respective taxa, despite being devoid of a brain or nervous system, are capable of sensing their immediate and momentary environment and responding accordingly. In the case of single-celled life, the sensory pathways are even more primitive in the sense that they take place on the surface of a single cell, as opposed to a network of many cells.
en.wikipedia.org/wiki/Plant_perception_(physiology)
Recent surprising similarities between plant cells and neuronsPlant cells and neurons share several similarities, including non-centrosomal microtubules, motile post-Golgi organelles, separated both spatially/structurally and functionally from the Golgi apparatus and involved in vesicular endocytic recycling, as well as cell-cell adhesion domains based on the actin/myosin cytoskeleton which serve for cell-cell communication. Tip-growing plant cells such as root hairs and pollen tubes also resemble neurons extending their axons. Recently, surprising discoveries have been made with respect to the molecular basis of neurodegenerative disorders known as Hereditary Spastic Paraplegias and tip-growth of root hairs. All these advances are briefly discussed in the context of other similarities between plant cells and neurons.There are very prominent similarities between tip-growing plant cells and the extending axons of neurons. However, recent advances reveal that these visible similarities stretch beyond the tip-growing plant cells and include plant tissue cells generating action potentials3 and accomplishing vesicle trafficking and recycling, typically at actin/myosin enriched cell-cell adhesion domains resembling neuronal synapses. Moreover, plant cells and neurons are similar from the cellular perspective, when most of their microtubules and Golgi apparatus organelles are not associated with the perinuclear centrosomes.In plant cells, Golgi stacks and Trans-Golgi Networks (TGNs) are motile organelles extending through the whole plant cells. Similarly in neurons centrosome-independent cortical microtubules are abundant in axons. They transport, among other cargo, so-called Golgi Outposts—which correspond to the TGNs of plant cells toward neuronal synapses. In both plant cells and neurons, TGNs act as independent organelles separated both spatially/structurally and functionally from the Golgi apparatus.Intriguingly, similarly as in neurons, also the TGN of plant cells is the inherent part of the endosomal/vesicular recycling pathways, supporting the dynamic and communicative nature of plant synapses.Plant action potentials (electric spikes) run in an axial direction, along the longitudinal axis of any plant organ, and the highest spike activity was scored in the transition zone of the root apex in maize.Hereditary spastic paraplegia (HSP) represents a heterogeneous group of genetic neurodegenerative disorders affecting the longest neurons of the human body, extending from the brain along the spinal cord /down to the legs.21 In the HSP disorders, axons of these long neurons degenerate causing problems in controlling leg muscles. One of the major genes in which mutation results in the HSP is Atlastin. Recent study has reported that Atlastin is homologous to the RHD3 protein of Arabidopsis.RHD3 protein is essential for proper growth and development of root hairs in Arabidopsis.Moreover, RHD3 is also important for the proper arrangement of root cell files which underlies the direction of root growth.In order to maintain their ordered cell files, root apex cross-walls (plant root synapses) perform active vesicle recycling. Both Arabidopsis RHD3 and Drosophila Atlastin are important for shaping tubular ER networks.RHD3 is also known to be required for the proper arrangement of the actin cytoskeleton and cell wall maintenance via vesicle trafficking.Moreover, similarly as Atlastin in neurons,RHD3 is important for the GA morphogenesis in plant cells too Importantly, both RHD3 and Atlastin are implicated in membrane tubulation and vesiculation whereas rhd3 mutant line emerges to be less active in endocytic internalization of FM endocytic tracer.Drosophila Atlastin regulates the stability of muscle microtubules and is required for both the axonal maintenance and synapse development. All this suggest that Arabidopsis emerges as an attractive and useful model object for investigations of mechanisms underlying HSP disorders in humans.Glutamate is one of the best understood and the most widespread excitatory .neurotransmitter which is perceived via glutamate receptors at brain synapses in animals and humans. These neuronal receptors have, in fact, deep evolutionary origin in prokaryotic bacteria, and are present also in plants., Importantly, the plant glutamate receptors have all the features of neuronal ones, and glutamate induces plant action potentials., All this strongly suggest that glutamate serves in neurotransmitter-like cell-cell communication in plants too. Interestingly in this respect, especially the root apices are target of the neuronal-like activity of glutamate in plants, with effects on cell development, root growth, morphogenesis, and behavior. The transition zone cells, localized between the apical meristem and basal cell elongation zone, respond to glutamate with rapid depolarization of the plasma membrane and this response is blocked by a specific antagonist of ionotropic glutamate receptors, 2-amino-5-phosphonopentanoate.Cells of the transition zone, also known as the distal elongation zone or the basal meristem, are crucial for root primordia priming,and exogenous glutamate is known to decrease primary root growth and increase lateral root proliferation.Beta-N-methylamino-L-alanine (BMAA) is a neurotoxic amino acid, derived from cycads, which is well-known to act as agonists and antagonists of mammalian glutamate receptors. BMAA inhibits root growth, cotyledon opening, and it stimulates elongation of light-grown hypocotyls in Arabidopsis.BMAA affects growth of Arabidopsis organs at very low concentrations, and these BMAA-induced effects are reversed by the addition of glutamate.This is consistent with a scenario wherein BMAA acts to block plant-specific glutamate receptors.Similarly to glutamate, aluminium also induces very rapid plasma membrane depolarization specifically in cells of the root apex transition zone. Moreover, glutamate and aluminium both induce rapid and strong calcium spikes with unique signatures in cells of the transition zone.These root cells represent the primary target for the aluminium toxicity in plants, whereas aluminium is not toxic to root cells which have already entered the rapid elongation region.Similarly, although aluminium is not so toxic in most plant cells, neuronal-like tip-growing root hairs and pollen tubes1,2 are sensitive to aluminium similarly as are the transition zone cells. In these latter cells, aluminium is specifically internalized via endocytosis. Internalized endocytic aluminium interferes with vesicle trafficking/recycling and endocytosis, inhibiting the PIN2-driven basipetal auxin transport in the transition zone of root apices.Aluminium targets specifically the auxinsecreting plant synapses and affects the polar auxin-transport-based root cell patterning. Moreover, aluminium affects also nitric oxide (NO) production which is highest in cells of the the distal portion of the transition zone. Importantly, the rapidly elongating root cells are not sensitive towards aluminium and neither is there internalization of aluminium into rapidly elongating root cells. In support of the endocytosis of aluminium being the primary process linked to the aluminium toxicity in root cells, endocytosis of aluminium and its toxicity is lowered in the Arabidopsis mutant over-expressing the DnaJ domain protein auxillin which regulates the clathrin-based endocytosis.In animals and humans, neuronal cells are extremely sensitive towards aluminium which is internalized via endocytosis specifically in these cells. Aluminium was found to be enriched in lysosomes, similarly like Alzheimer’s amyloid β-peptide plaque depositions. These are also internalized from cell surface and aluminium was reported to inhibit their degradation.In conclusion, in both transition zone root cells and neurons, endocytosis of aluminium emerges as relevant to its high biotoxicity. In plants, the aluminium toxicity is the most important limiting factor for crop production in acid soil environments worldwide. Further studies on these cells might give us crucial clues not only for plant biology and agriculture but also for our still limited understanding of the Alzheimer disease. In line with the original proposal of Charles and Francis Darwin, root apices of plants represent neuronal/anterior pole of plant bodies
This striking Vivid installation illustrates the complexity and connectivity of the human brain. It's the creation of industrial design firm Amigo and Amigo and technology company S1T2, and explores the effects of Alzheimer's disease on electrochemical activity in the brain (not to mention the camera's colour sensors).
Touching the sculpture triggers a colour response. Purple light represents the emergence of Alzheimer’s disease. When the purple path reaches a neuron, it disconnects, signifying that memories will be lost.
For the technically minded, "Affinity" features Onled LED's lighting and 19 Intel Galileo boards in an interactive display using over 56 colours, 114 capacitive sensors and 4200 meters of LED strip lighting. There are 70 balls each with six sensors, and about 48 arms.
Neuron projections from the visual cortex have been known to extend to cells of the brainstem that regulate innate motor behaviors. This image shows a neuron projection from the visual cortex of a mouse.
More information: www.nih.gov/news-events/news-releases/visual-cortex-plays...
This image is not owned by the NIH. It is shared with the public under license. If you have a question about using or reproducing this image, please contact the creator listed in the credits. All rights to the work remain with the original creator.
Credit: Dr. Massimo Scanziani
NIH funding from: National Eye Institute (NEI)
This composite image shows two neurons in the locust brain (one colored orange, one colored blue) that process information about odors.
Credit: Mark Stopfer, National Institute of Child Health and Human Development, NIH
Taken at SFU's cellular neuroscience lab (Silverman Lab) under fluorescent microscope (therefore no EXIF)
Neurons were stained using the following markers:
(MAP2 cyan and Synapsin pink)
LOOK KG 243 racer from late 1990's built with Columbus Neuron steel. Components are generally 2000's - but a mix of new and old.
Photo: Thomas Ohlsson Photography
www.thomasohlsson.com | 500px | Facebook | Flickr | Instagram