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Brain Size May Increase with Exercise, According to Study

Aerobic exercise can improve memory function and maintain brain health as we age, a new Australian-led study has found.

In a first of its kind international collaboration, researchers from Australia’s National Institute of Complementary Medicine at Western Sydney University and the Division of Psychology and Mental Health at the University of Manchester in the UK examined the effects of aerobic exercise on a region of the brain called the hippocampus, which is critical for memory and other brain functions.

Brain health decreases with age, with the average brain shrinking by approximately five per cent per decade after the age of 40.

Studies in mice and rats have consistently shown that physical exercise increases the size of the hippocampus but until now evidence in humans has been inconsistent.

The researchers systematically reviewed 14 clinical trials which examined the brain scans of 737 people before and after aerobic exercise programs or in control conditions.

The participants included a mix of healthy adults, people with mild cognitive impairment such as Alzheimer’s and people with a clinical diagnosis of mental illness including depression and schizophrenia. Ages ranged from 24 to 76 years with an average age of 66.

The researchers examined effects of aerobic exercise, including stationary cycling, walking, and treadmill running. The length of the interventions ranged from three to 24 months with a range of 2-5 sessions per week.

Overall, the results – published in the journal NeuroImage – showed that, while exercise had no effect on total hippocampal volume, it did significantly increase the size of the left region of the hippocampus in humans.

Lead author, NICM postdoctoral research fellow, Joseph Firth said the study provides some of the most definitive evidence to date on the benefits of exercise for brain health.

“When you exercise you produce a chemical called brain-derived neurotrophic factor (BDNF), which may help to prevent age-related decline by reducing the deterioration of the brain,” Mr. Firth said.

“Our data showed that, rather than actually increasing the size of the hippocampus per se, the main ‘brain benefits’ are due to aerobic exercise slowing down the deterioration in brain size. In other words, exercise can be seen as a maintenance program for the brain.”

Mr. Firth said along with improving regular ‘healthy’ aging, the results have implications for the prevention of aging-related neurodegenerative disorders such as Alzheimer’s and dementia – however further research is needed to establish this.

Interestingly, physical exercise is one of the very few ‘proven’ methods for maintaining brain size and functioning into older age.

The paper, “Effects of aerobic exercise on hippocampal volume in humans: a systematic review and meta-analysis” is available online here.

NICM

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Science & Technology

Designer has created a concept for the electric bike of the future

Futuristic motorcycles have become part of popular culture, associated with the concepts of the near future. They appeared in the film ” Tron: Legacy”, the anime “Akira” and in many video games from the “cyberpunk” genre. Recently, Russian designer Roman Dolzhenko presented his version of the bike of the future.

Russian designer has created a concept for the electric bike of the futureromorwise.com

MIMIC eBike – the concept of an electric superbike – originally existed as a sketch on a paper napkin. Later, the designer made the idea more realistic by rendering in 3DS max.

Minimalism prevails in motorcycle design. It lacks straight lines and protrusions. The dashboard of the bike is completely digital, and consists of a solid display showing basic information (speed and battery charge status).

Superbike MIMICromorwise.com

There are very few details about the superbike. Social network users are most often concerned about the question: how to turn the steering wheel with this design? The front wheel fairing and handlebar structure appear to be inactive. In an interview for InceptiveMind, Dolzhenko answered this question: the front of the motorcycle turns completely, but at a slight angle.

Superbike MIMICromorwise.com

There is no information on the cost of transport, capacity and production, which is not surprising. MIMIC eBike is just an extremely realistic concept art of the motorcycle of the future. Perhaps in a couple of years, some Elon Musk will adapt the MIMIC design for a real electric superbike.

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Genes work differently in men and women

All of our cells have the same genes. They can have mutations, however, both in the muscle cell and in the neuron there is a gene for the globin protein, an insulin gene, an acetylcholinesterase gene, etc. But is it worth reminding that a muscle cell is not like a nerve cell? The point is that genes work differently in different cells.

… although these differences should not be exaggerated – even the end sections of chromosomes, which determine biological age, look the same in men and women.

More than ten years ago, a large international team of researchers launched the GTEx (Genotype-Tissue Expression) project, the goal of which was to determine the activity of all genes in all human tissues and organs. Samples of 49 tissues were taken from 838 donors – dead healthy people, mostly elderly. First of all, the DNA was read from each of the donors. Second, the amount of different RNA was analyzed in each tissue. As you know, genetic information from genes in DNA is first read into the messenger RNA (mRNA) molecule, and then proteins are already synthesized on the mRNA molecule (for simplicity, we are not talking about a large class of RNAs that do not encode proteins and which themselves perform various important functions in the cell). The more active a gene is, the more mRNA is read from it. Therefore, by the level of different mRNAs, one can understand where which genes are more active,

The activity of a gene depends on special regulatory sequences, which are also recorded in the DNA – that is, some sections of DNA affect others. By comparing the genetic text in DNA with the amount of different RNAs in different people, one can understand which regulatory regions in DNA affect a particular gene. Such regions (or loci) in DNA are called eQTL, expression quantitative trait loci, which can be roughly translated as loci that determine the level of activity.

As a result of the work, a whole bundle of fifteen articles was recently published in Science , Science Advances , Cell and other journals. Now, using the map of tissue genetic activity for each gene, you can check how it should work in a particular organ or part of it (because several samples were taken from each organ). On the other hand, by looking for a regulatory region (eQTL) in a person’s genome, one can estimate how certain genes will work. It’s genes – because each regulatory eQTL affects more than two genes.

Another important result concerns telomeres, the ends of chromosomes that shorten with each cell division. Telomeres are often used to assess biological age: the shorter they are, the older the body is. But usually blood cells are taken to measure telomeres. What if different fabrics age differently?

The researchers estimated the length of the end sections of chromosomes in 23 tissues, and came to the conclusion that blood does indeed provide an indication of age in general: telomeres in blood cells shorten in proportion to telomeres in other tissues. At the same time, earlier studies were not confirmed, in which female telomeres were on average longer than male ones – that is, neither women nor men have telomere advantages. Which is curious in its own way, since it is believed that women generally live longer than men . This is probably because telomeres are a significant, but not the only indicator of age. In addition, it was not possible to see a strong shortening of telomeres in smokers (here it is worth noting that lung cancer can occur without telomere shortening).

By the way, about women and men. Gender differences are hard to ignore, and we all know that men and women have different sex chromosomes and that men and women have different hormones. Obviously, this should affect the work of genes. Indeed, researchers have found that 37% of our genes work differently in men and women in at least one tissue. Moreover, some genes, relatively speaking, “work” only in one sex. For example, men with different DPYSL4 gene variants will have different body fat percentages. But in women, the DPYSL4 gene does not affect body fat – this does not mean that the gene does not work, just the amount of adipose tissue depends on other genes. Similarly, in men with different variants of the CLDN7 genethere will be different birth weights. In women, birth weight is linked to another gene, HKDC1 .

Many genes, whose activity depends on sex, are associated with diseases, but their “sex” differences were still unknown. Obviously, this information is useful in personalized therapy, when the patient is being treated according to his individual genetic characteristics. However, the authors of the work note that although a lot of “sex-dependent” genes were found, their activity itself does not change very much. In general, the gender genetic differences between men and women are not very large. We emphasize that this is precisely if we take it as a whole – because the genes on which, say, primary and secondary sexual characteristics depend, work in men and women in very different ways.

What else affects gene activity? For example, age – but here there is a gap in the received data. Above we said that the samples were taken mostly from people in years; in addition, more material is needed to analyze age differences across the entire genome. (By the way, it is possible that sex differences are manifested in different ways at different ages.) Some experts, according to The Scientist portal , generally strongly doubt the reliability of the results, because samples were taken from the dead, and not from living people. On the other hand, where can we find healthy volunteers who would allow them to take a piece of tissue from the bowels of their own brain? Subsequent studies are likely to greatly adjust this map of tissue gene activity, but, one way or another, the new data will have something to compare with.

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What are dark matter and dark energy?

An article devoted to the search for dark matter has been published in the scientific journal Nature. To better understand what it is, astronomers have created a detailed computer model of the “web of the universe”, which includes various clusters of this mysterious substance.

“Cobweb” will help find signs of decay

“Our calculations show that small clusters of dark matter should be very common in the Universe. But by themselves they will remain completely invisible to our telescopes, “admitted one of the authors of the work, professor at the Max Planck Astrophysical Institute (Germany) Simon White .

According to the modern concepts of cosmologists, immediately after the Big Bang, matter in the Universe was divided into visible and dark matter. Their distribution was uneven. Researchers call the three-dimensional model of the distribution of forms of matter “cobweb”. They hope that thanks to it it will be possible to find traces of the decay of dark matter particles. This will help to somehow study its properties.

Back in January, predictions were made that in 2020 astrophysicists will attempt to detect dark matter and dark energy, which account for about 95% of the mass of the Universe. Science still knows almost nothing about these mysterious substances. 

So what do scientists know today?

These particles permeate our bodies every second

“Until we understand what dark matter is, what kind of substance it is and what kind of particles. Physicists have not yet learned how to register them, – explains a senior researcher at the State Astronomical Institute. P.K.Sternberg Moscow State University Vladimir Surdin

It was not physicists who learned about the existence of dark matter, but astronomers. Ever since the 1930s, observing the movement of neighboring galaxies, they realized that there are not only stars there. Their gravity is much stronger than stars, planets, interstellar gas and other matter we observe could provide.

Stars are the main objects we see. But their mass is clearly not enough to explain the mass of galaxies as a whole. Stars at large distances from the center of galaxies orbit these centers rather quickly. But according to the laws of physics, this should not be so: as you move away from the center of gravity, the speed of movement of bodies should decrease, look at least at our solar system.

This means that far from the center of galaxies there is something that provides gravity, some kind of invisible, hidden mass. And we know for sure that this cannot be a substance that is so familiar to us, with its protons, electrons, neutrons. These are particles of a new type. They surround us and permeate our bodies every second, but we do not feel them. And physicists cannot yet create devices that would be able to register them.

Scientists judge about the existence of dark matter on other grounds. For example, on the decays of star clusters, which should not have occurred if there was no interaction with some substance invisible to us. And also by the effect of a gravitational lens: clusters of galaxies bend the rays of light that come from objects located behind them. It should be so, it follows from the theory of relativity, but the calculation of the distortion shows that there is much more invisible matter than visible. More about five times.

Another mystery of science is dark energy. Physicists do not even try to solve it in laboratories, only theoretically.

In the twentieth century, astronomers recorded the movement of galaxies and found that almost all of them were moving away from us. When Edwin Hubble learned to measure the distance to galaxies, it turned out that the farther a galaxy is from us, the faster it flies away. Mathematicians have described all these patterns. It turned out that there are not so many options for the expansion of the Universe. And the mutual attraction of galaxies should stop their run-up: like a stone thrown upwards, at some point it stops and begins to fall to the ground.

In the late 1980s, new data emerged. Scientists have discovered that the movement of galaxies is not only not slowed down, but, on the contrary, accelerates. This meant that there is a force in nature that overcomes gravity at significant distances, a kind of anti-gravity. And if the first 7 billion years after the Big Bang was won by gravity, then another force began to win, which began to push the galaxies apart.

This power has been given a conventional name: dark energy. Scientists can calculate the energy itself, but they cannot indicate its carrier. Whether it is some kind of field, or a property of the vacuum, is still unclear. “

Dark energy, according to the Planck Space Observatory, accounts for 68.3% of the observed Universe, and dark matter – 26.8%. And only 4.9% are visible objects.

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