Indeed

Indeed,

#Earth #wordsofwisdom

Infinite unwinder

Infinite unwinder
The problem with introspection is that it has no end.
~Philip K. Dick

work by bigblueboo
https://twitter.com/bigblueboo

#math #animation #processing #C4D #design

Navigation System of Brain Cells Decoded

Navigation System of Brain Cells Decoded
The human brain contains roughly 100 billion neurons. Information among them is transmitted via a complex network of nerve fibers. Hardwiring of most of this network takes place before birth according to a genetic blueprint, that is without external influences playing a role. Researchers of Karlsruhe Institute of Technology (KIT) have now found out more about how the navigation system guiding the axons during growth works.

Total length of the nerve fiber network in the brain is approximately 500,000 km, more than the distance between the earth and the moon. Growth of the nerve fibers is controlled by a navigation system to prevent incorrect hardwiring. But how exactly do the nerve fibers find their target region during growth? “This is similar to autonomous driving in road traffic,” says Franco Weth of the Cell and Neural Biology Division of the Zoological Institute.

Vehicles exchange information with each other and with signal transmitters at the roadside to reach their destination. In case of nerve fibers, sensor molecules at their ends serve as antennas. With them, they receive guiding signals in the form of proteins that are positioned along the way, in the target area, and on other fibers crossing the path. Having arrived at the target, axons form interconnections with other neurons, the synapses.

An example of such hardwiring is the connection between retina and brain, Weth says. Nearly one million nerve fibers reach the visual regions via the visual nerve. Genetically pre-programmed “neural hardwiring” causes the pixels to be reproduced one-to-one similar to a projection and, thus, enables a newborn child to see and process an image. This vital capability has developed by evolution of our species and does not have to be acquired by own experience. “Only few synapses of our brain are hardwired by learning,” Weth points out.

Surprisingly, the axons’ sensitivity to incoming signals of their protein navigation system decreases during the travel. “Still, information has to be read out precisely for the axons to find their target,” Weth and his colleagues wondered. The solution: “The axons indeed are desensitized for all types of signals guiding them, but they surprisingly preserve the ratio of signal strengths to each other,” Weth says. In the end, the target is characterized by a certain ratio of several signals rather than by the intensity of a single signal.

Thanks to this refined coupling of sensitivities, the axonal navigation system manages the conflict between reliability and variability of signals. This type of coupled signal regulation is highly unusual in biology. “Although you quickly cease to notice the smell of the perfume of the person opposite you, this does not mean that you no longer smell the coffee you are drinking at the moment. But this is what happens in the brain.”

Researchers do not yet know why navigation of the axons is desensitized contrary to the naïve expectation that a strong signal will most certainly guide them to their target. “We presume that it is a strategy to save energy, because signal transmission needs energy,” Weth says. Actually, nature is striving for disorder.” Establishing order consumes energy. This is something we know. Nothing in biology is more ordered than the hardwiring of our brain. Only when nature minimizes hardwiring expenditure, can it achieve the top performance required to equip us with this ‘cognition computer’.”

With their findings, the researchers also contribute to better understanding diseases caused by hardwiring errors prior to birth. Among these diseases are the Tourette syndrome, autism, or schizophrenia.

Source:
https://www.kit.edu/kit/english/pi_2017_106_navigation-system-of-brain-cells-decoded.php

Image: Embryonal brain development: Axons (green) of retina neurons read biochemical signals by means of a growth cone (magenta) equipped with molecular antennas and guide them to targets to interconnect the visual system of the brain. Credit: KIT, Weth

#navigation #braincells #nervefibers #axons #neuroscience

Is Alzheimer’s Disease a Disorder of Energy Metabolism? New Study Shines New Light

Is Alzheimer’s Disease a Disorder of Energy Metabolism? New Study Shines New Light
A team of investigators from McLean Hospital and Harvard Medical School, led by Kai C. Sonntag, MD, PhD, and Bruce M. Cohen, MD, PhD, has found a connection between disrupted energy production and the development of late-onset Alzheimer’s disease (LOAD).

“These findings have several implications for understanding and developing potential therapeutic intervention in LOAD,” explained Sonntag, an associate stem cell researcher at McLean Hospital and an assistant professor of psychiatry at Harvard Medical School. “Our results support the hypothesis that impairment in multiple interacting components of bioenergetics metabolism may be a key mechanism underlying and contributing to the risk and pathophysiology of this devastating illness.”

For three decades, it has been thought that the accumulation of small toxic molecules in the brain, called amyloid beta, or in short, Aβ, is central to the development of Alzheimer’s disease (AD). Strong evidence came from studying familial or early-onset forms of AD (EOAD) that affect about five percent of AD patients and have associations with mutations leading to abnormally high levels or abnormal processing of Aβ in the brain. However, the “Aβ hypothesis” has been insufficient to explain the pathological changes in the more common LOAD, which affects more than 5 million seniors in the United States.

“Because late-onset Alzheimer’s is a disease of age, many physiologic changes with age may contribute to risk for the disease, including changes in bioenergetics and metabolism,” said Cohen, director of the Program for Neuropsychiatric Research at McLean Hospital and the Robertson-Steele Professor of Psychiatry at Harvard Medical School. “Bioenergetics is the production, usage, and exchange of energy within and between cells or organs, and the environment. It has long been known that bioenergetic changes occur with aging and affect the whole body, but more so the brain, with its high need for energy.”

According to Sonntag and Cohen, it has been less clear what changes in bioenergetics are underlying and which are a consequence of aging and illness.

In their study, Sonntag and Cohen analyzed the bioenergetic profiles of skin fibroblasts from LOAD patients and healthy controls, as a function of age and disease. The scientists looked at the two main components that produce energy in cells: glycolysis, which is the mechanism to convert glucose into fuel molecules for consumption by mitochondria, and burning of these fuels in the mitochondria, which use oxygen in a process called oxidative phosphorylation or mitochondrial respiration.

The investigators found that LOAD cells exhibited impaired mitochondrial metabolism, with a reduction in molecules that are important in energy production, including nicotinamide adenine dinucleotide (NAD). LOAD fibroblasts also demonstrated a shift in energy production to glycolysis, despite an inability to increase glucose uptake in response to the insulin analog IGF-1. Both the abnormal mitochondrial metabolism and the increase of glycolysis in LOAD cells were disease- and not age-specific, while diminished glucose uptake and the inability to respond to IGF-1 was a feature of both age and disease.

“The observation that LOAD fibroblasts had a deficiency in the mitochondrial metabolic potential and an increase in the glycolytic activity to maintain energy supply is indicative of failing mitochondria and fits with current knowledge that aging cells increasingly suffer from oxidative stress that impairs their mitochondrial energy production,” said Sonntag.

Cohen added that because the brain’s nerve cells rely almost entirely on mitochondria-derived energy, failure of mitochondrial function, while seen throughout the body, might be particularly detrimental in the brain.

The study’s results link to findings from other studies that decreasing energy-related molecules (and specifically NAD) are features of normal aging by suggesting that abnormalities in processes involving these molecules may also be a factor in neurodegenerative diseases like LOAD. Whether modulating these compounds could slow the aging process and prevent or delay the onset of LOAD is unknown. However, several clinical trials are currently under way to test this possibility. Other changes are unique to AD, and these, too, may be targets for intervention.

While these findings are significant, the paper’s authors emphasize that the pathogenesis of LOAD is multifactorial, with bioenergetics being one part of risk determination and note that the skin fibroblasts studied are not the primary cell type that is affected in LOAD.

“However, because bioenergetics changes are body-wide, observations made in fibroblasts may also be relevant to brain cells,” said Sonntag. “In fact, metabolic changes like diminished glucose uptake and insulin/IGF-1 resistance may underlie the association between various disorders of aging, such as type 2 diabetes and AD.”

Sonntag and Cohen are already in the midst of follow-up work aiming to study these bioenergetics features in brain nerve cells and astrocytes generated from LOAD patient-derived induced pluripotent stem cells, as an aging and disease model in the dish. It is the group’s hope that findings from these studies will reveal further insight into the role of bioenergetics in LOAD pathogenesis and novel targets for intervention—both prevention and treatment.

Journal article:
https://www.nature.com/articles/s41598-017-14420-x

Source:
https://www.mcleanhospital.org/news/alzheimers-disease-disorder-energy-metabolism-new-study-shines-new-light

#alzheimersdisease #betaamyloid #glycolysis #bioenergetics #neuroscience #medicine #research

M57: The Ring Nebula

M57: The Ring Nebula
Except for the rings of Saturn, the Ring Nebula (M57) is probably the most famous celestial band. Its classic appearance is understood to be due to our own perspective, though. The recent mapping of the expanding nebula's 3-D structure, based in part on this clear Hubble image, indicates that the nebula is a relatively dense, donut-like ring wrapped around the middle of a (American) football-shaped cloud of glowing gas.

The view from planet Earth looks down the long axis of the football, face-on to the ring. Of course, in this well-studied example of a planetary nebula, the glowing material does not come from planets. Instead, the gaseous shroud represents outer layers expelled from the dying, once sun-like star, now a tiny pinprick of light seen at the nebula's center. Intense ultraviolet light from the hot central star ionizes atoms in the gas. The Ring Nebula is about one light-year across and 2,000 light-years away.

Image & info via APOD
https://apod.nasa.gov/apod/ap180417.html
Image Credit: NASA, ESA, Hubble Legacy Archive; Composition: Giuseppe Donatiello

#space #universe #science #nebula #NASA

Neutrino experiment at Fermilab delivers an unprecedented measurement

Neutrino experiment at Fermilab delivers an unprecedented measurement
Tiny particles known as neutrinos are an excellent tool to study the inner workings of atomic nuclei. Unlike electrons or protons, neutrinos have no electric charge, and they interact with an atom's core only via the weak nuclear force. This makes them a unique tool for probing the building blocks of matter. But the challenge is that neutrinos are hard to produce and detect, and it is very difficult to determine the energy that a neutrino has when it hits an atom.

This week, a group of scientists working on the MiniBooNE experiment at the Department of Energy's Fermilab reported a breakthrough: They were able to identify exactly-known-energy muon neutrinos hitting the atoms at the heart of their particle detector. The result eliminates a major source of uncertainty when testing theoretical models of neutrino interactions and neutrino oscillations.

"The issue of neutrino energy is so important," said Joshua Spitz, Norman M. Leff assistant professor at the University of Michigan and co-leader of the team that made the discovery, along with Joseph Grange at Argonne National Laboratory. "It is extraordinarily rare to know the energy of a neutrino and how much energy it transfers to the target atom. For neutrino-based studies of nuclei, this is the first time it has been achieved."

To learn more about nuclei, physicists shoot particles at atoms and measure how they collide and scatter. If the energy of a particle is sufficiently large, a nucleus hit by the particle can break apart and reveal information about the subatomic forces that bind the nucleus together.

But to get the most accurate measurements, scientists need to know the exact energy of the particle breaking up the atom. That, however, is almost never possible when doing experiments with neutrinos.

Like other muon neutrino experiments, MiniBooNE uses a beam that comprises muon neutrinos with a range of energies. Since neutrinos have no electric charge, scientists have no "filter" that allows them to select neutrinos with a specific energy.

MiniBooNE scientists, however, came up with a clever way to identify the energy of a subset of the muon neutrinos hitting their detector. They realized that their experiment receives some muon neutrinos that have the exact energy of 236 million electronvolts (MeV). These neutrinos stem from the decay of kaons at rest about 86 meters from the MiniBooNE detector emerging from the aluminum core of the particle absorber of the NuMI beamline, which was built for other experiments at Fermilab.

Energetic kaons decay into muon neutrinos with a range of energies. The trick is to identify muon neutrinos that emerge from the decay of kaons at rest. Conservation of energy and momentum then require that all muon neutrinos emerging from the kaon-at-rest decay have to have exactly the energy of 236 MeV.

Source & further reading: https://phys.org/news/2018-04-neutrino-fermilab-unprecedented.html#jCp

Journal article:
https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.120.141802

#physics #neutrinos #Fermilab #science

Three Coronal Holes

Three Coronal Holes
For much of this week the sun featured three substantial coronal holes (Apr. 3-6, 2018). Coronal holes appear as large dark areas which are identified with arrows in the still image. These are areas of open magnetic field from which high speed solar wind rushes out into space. This wind, if it interacts with EarthÕs magnetosphere, can cause aurora to appear near the poles. They are not at all uncommon.

Credit: Solar Dynamics Observatory, NASA.
https://sdo.gsfc.nasa.gov/gallery/potw/item/890

#universe #space #coronalholes #sun #SDO #NASA

Dragon Aurora over Norway

Dragon Aurora over Norway
What's that in the sky? An aurora. A large coronal hole opened last month, a few days before this image was taken, throwing a cloud of fast moving electrons, protons, and ions toward the Earth. Some of this cloud impacted our Earth's magnetosphere and resulted in spectacular auroras being seen at high northern latitudes.

Featured here is a particularly photogenic auroral curtain captured above Tromsø Norway. To the astrophotographer, this shimmering green glow of recombining atmospheric oxygen appeared as a large dragon, but feel free to share what it looks like to you. Although now past Solar Maximum, our Sun continues to show occasional activity creating impressive auroras on Earth visible even last week.

Image & info via APOD
https://apod.nasa.gov/apod/astropix.html
Image Credit & Copyright: Marco Bastoni

#naturalphenomena #aurora #science #NASA

Nature or Nurture? Innate Social Behaviors in the Mouse Brain

Nature or Nurture? Innate Social Behaviors in the Mouse Brain
Adult male mice have a simple repertoire of innate, or instinctive, social behaviors: When encountering a female, a male mouse will try to mate with it, and when encountering another male, the mouse will attack. The animals do not have to be taught to perform these behaviors. This has led to the widespread presumption among neuroscientists that the brain circuits mediating these behaviors are “hardwired,” meaning that they are genetically encoded pathways with little flexibility.

But new research from Caltech neuroscientists shows that these behaviors and the neurons that represent them are not as fixed as previously believed.

The work appeared in the journal Nature, and was led by David Anderson—Seymour Benzer Professor of Biology; Tianqiao and Chrissy Chen Institute for Neuroscience Leadership Chair; Howard Hughes Medical Institute Investigator; and director of the Tianqiao and Chrissy Chen Institute for Neuroscience.

The team used mice that had been genetically engineered so that neurons in a specific part of the brain involved in aggression and sexual behavior—the ventromedial hypothalamus (VMH)—would glow green when activated. To visualize this activation, a needle-thin glass lens was inserted into the hypothalamus, and images of flashing neurons were recorded by a miniature, portable microscope attached to the mouse’s head. This brain imaging technology was originally developed by Anderson’s collaborator at Stanford University, Mark Schnitzer, and obtained through Inscopix.

The Caltech team first set up “resident/intruder tests,” in which they imaged the brain of a socially and sexually experienced “resident” mouse in its cage as a single intruder mouse—either a male or a female—was introduced. The researchers found that during its encounters with other mice, one of two distinct sets of neurons in the VMH were activated—one set if the other mouse was a male, and another if it was a female. Though these neurons are spatially intermingled, there is very little overlap between them, like grains of salt and pepper interspersed on a plate.

Just by looking at the activation of these two neural populations, the scientists could reliably determine whether an animal was interacting with a male or a female. These observations seemed to support the idea that these distinct representations of males versus females are hardwired and genetically fixed from birth.

To test this idea more directly, the researchers examined the behaviors of naïve mice—those that had been maintained in isolation since weaning, without any social or sexual experience. If the sex distinction was indeed hardwired, then the researchers should have seen the separate activation of the groups of neurons specific for recognizing males versus females, even during the first encounters between these naïve mice and other male or female intruder mice.

Surprisingly, to the contrary, the neurons of these naïve mice initially were similarly activated when the mice were exposed to either male or to female mice. At the same time, these mice initially exhibited little fighting (with males) or mating (with females) behaviors. Only after repeated social experience—contact with either male or female mice for two minutes, five times a day, for three days—did the separate sets of neurons representing male versus female mice appear. This separation occurred just as the mice began to exhibit aggression toward males and mating with females.

Further studies indicated that social experience with a female seemed to be the key requirement for the mice to develop separate, sex-specific populations of neurons, as well as aggressive behavior. As little as 30 minutes of social interaction with a female, the team found, was enough to make naïve mice aggressive towards males 24 hours later, as well as to cause the separation of male- versus female-specific representations in the mouse’s brain. Naïve mice that were exposed only to males did not develop aggressive behaviors, nor did they show this separation.

Source:
http://www.caltech.edu/news/nature-or-nurture-innate-social-behaviors-mouse-brain-80135

Journal article:
https://www.nature.com/articles/nature23885

#animalbehavior #socialbehavior #hypothalamus #naturevsnurture #neuroscience #research

There's no standing still because time is moving forward.

There's no standing still because time is moving forward.
G. Lake

Work by bigblueboo

#math #animation #processing

Self-healing metal oxides could protect against corrosion

Self-healing metal oxides could protect against corrosion
Researchers have found that a solid oxide protective coating for metals can, when applied in sufficiently thin layers, deform as if it were a liquid, filling any cracks and gaps as they form.

The thin coating layer should be especially useful to prevent leakage of tiny molecules that can penetrate through most materials, such as hydrogen gas that could be used to power fuel-cell cars, or the radioactive tritium (a heavy form of hydrogen) that forms inside the cores of nuclear power plants.

Most metals, with the notable exception of gold, tend to oxidize when exposed to air and water. This reaction, which produces rust on iron, tarnish on silver, and verdigris on copper or brass, can weaken the metal over time and lead to cracks or structural failure. But there are three known elements that produce an oxide that can actually serve as a protective barrier to prevent any further oxidation: aluminum oxide, chromium oxide, and silicon dioxide.

Ju Li, a professor of nuclear engineering and science at MIT and senior author of a paper describing the new finding, says “we were trying to understand why aluminum oxide and silicon dioxide are special oxides that give excellent corrosion resistance.” The paper appears in the journal Nano Letters.

Source:
http://news.mit.edu/2018/self-healing-metal-oxides-could-protect-against-corrosion-0404

Journal article:
https://pubs.acs.org/doi/10.1021/acs.nanolett.8b00068

Gif: a thin layer of aluminum oxide separates oxygen gas (right) and two aluminum metal grains (left). As the material is stretched, the oxide layer elongates.

#nanoscience #nanotech #research #science

April 4 is reserved to Maya Angelou

April 4 is reserved to Maya Angelou
“I've learned that people will forget what you said, people will forget what you did, but people will never forget how you made them feel.”

An acclaimed American poet, storyteller, activist, and autobiographer, Maya Angelou was born Marguerite Johnson in St. Louis, Missouri. Angelou has had a broad career as a singer, dancer, actress, composer, and Hollywood's first female black director, but is most famous as a writer, editor, essayist, playwright, and poet. As a civil rights activist, Angelou worked for Dr. Martin Luther King Jr. and Malcolm X. She was also an educator and served as the Reynolds professor of American Studies at Wake Forest University.

Angelou’s most famous work, I Know Why the Caged Bird Sings (1969), deals with her early years in Long Beach, St. Louis and Stamps, Arkansas, where she lived with her brother and paternal grandmother. In one of its most evocative (and controversial) moments, Angelou describes how she was first cuddled then raped by her mother's boyfriend when she was just seven years old. When the man was murdered by her uncles for his crime, Angelou felt responsible, and stopped talking. Angelou remained mute for five years, but developed a love for language. She read black authors like Langston Hughes, W. E. B. Du Bois, and Paul Lawrence Dunbar, as well as canonical works by William Shakespeare, Charles Dickens, and Edgar Allan Poe.

When Angelou was twelve and a half, Mrs. Flowers, an educated black woman, finally got her to speak again. Mrs. Flowers, as Angelou recalled in her children’s book Mrs. Flowers: A Moment of Friendship (1986), emphasized the importance of the spoken word, explained the nature of and importance of education, and instilled in her a love of poetry.

Source:
https://www.poetryfoundation.org/poets/maya-angelou

Bio:
https://www.biography.com/people/maya-angelou-9185388

#history #MayaAngelou #amazingwomen

Scientists reveal how inflammation affects the life of brain cells

Scientists reveal how inflammation affects the life of brain cells
King’s College London research reveals how blood inflammation affects the birth and death of brain cells, which could offer new treatment targets for antidepressants.

Mounting evidence points to high levels of inflammation as an important biological abnormality leading to depression in at least one third of patients. However, this new study offers the first evidence that inflammation may increase depression risk by reducing the birth of new cells and accelerating the naturally-occurring death of existing cells in the brain.

Using a research model made up of human brain cells, the researchers from King’s Institute of Psychiatry, Psychology & Neuroscience (IoPPN) examined the effects of a protein (interferon-alpha IFN-α), which is able to activate the immune system and ultimately to induce depressive symptoms in healthy people.

Specifically, they investigated the impact of IFN-α on the process of brain cell formation, called neurogenesis, which is known to occur in the hippocampus, a brain region highly involved in depression and antidepressant response. Neurogenesis is normally reduced by depression and chronic stress, and this reduction is thought to be clinically relevant to the development of depression.

These new findings, published in the International Journal of Neuropsychopharmacology, show that IFN-α reduces the birth of new brain cells and increases brain cell death in the hippocampus. The researchers demonstrated this by regulating the levels of four inflammatory proteins, which are known to activate the immune response and to regulate distinct brain functions related to depression.

Source:
https://www.kcl.ac.uk/ioppn/news/records/2017/10-October/Scientists-reveal-how-inflammation-affects-the-life-of-brain-cells.aspx

Journal article:
https://academic.oup.com/ijnp/article/21/2/187/4348673

#inflammation #braincells #neurogenesis #neuroscience #research

The physics of surfing ;)

The physics of surfing ;)
California cca. 1970

#history #coolteachers

Moons, Rings, Shadows, Clouds: Saturn (Cassini)

Moons, Rings, Shadows, Clouds: Saturn (Cassini)
While cruising around Saturn, be on the lookout for picturesque juxtapositions of moons, rings, and shadows. One quite picturesque arrangement occurred in 2005 and was captured by the then Saturn-orbiting Cassini spacecraft.

In the featured image, moons Tethys and Mimas are visible on either side of Saturn's thin rings, which are seen nearly edge-on. Across the top of Saturn are dark shadows of the wide rings, exhibiting their impressive complexity. The violet-light image brings up the texture of the backdrop: Saturn's clouds. Cassini orbited Saturn from 2004 until September of last year, when the robotic spacecraft was directed to dive into Saturn to keep it from contaminating any moons.

Image & info via APOD
https://apod.nasa.gov/apod/ap180402.html
Image Credit: NASA, JPL-Caltech, Space Science Institute

#space #NASA #Cassini #universe #science