SCIENCE AND LIFE

SCIENCE AND LIFE

SCIENCE AND LIFE

SCIENCE AND LIFE

SCIENCE AND LIFE

SCIENCE AND LIFE

SCIENCE AND LIFE

Bureau of foreign scientific and technical information. May 2018 №5

“Doctors’ Affairs” in the domestic history (long and not very)

In ancient times, doctors in Russia were mainly engaged in medicine men. The zhnahar craft combined elements of folk medicine with magic and witchcraft.

SCIENCE AND LIFE

Bureau of Scientific and Technical Information. May 2018 №5

The development of small space vehicles is one of the fastest growing areas of modern satellite engineering.

SCIENCE AND LIFE

Zinc will help alcohol-afflicted HIV-positive residents of St. Petersburg

The addition of compounds of this metal to food reduces mortality in this group of the population, and calls to drink less do not have a noticeable effect on the behavior of such people.

Zinc will help alcohol-afflicted HIV-positive residents of St. Petersburg

Employees of the First St. Petersburg State Medical University named after academician I.P. Pavlova together with colleagues from the United States conducted a clinical trial of the effect of zinc gluconate on the mortality and general health of HIV-infected St. Petersburg residents suffering from alcoholism. The study, which lasted a year and a half, showed that the addition of zinc to the diet reduces the rate of reproduction of HIV in the cells of the immune system of the infected and the concentration of substances – markers of bacterial distribution throughout the body. Since measures to combat alcoholism in Russia have very limited success, taking zinc gluconate can be a means of improving the condition of HIV-positive people with alcohol dependence. The scientific article is published in the journal HIV Clinical Trials.

Volunteers for the study were recruited in several drug dispensaries and centers for the prevention and control of AIDS in St. Petersburg from October 2013 to June 2015. The degree of their adherence to alcohol, viral load, antiviral medication, background emotional state, heredity, social status and some other characteristics were assessed using medical analyzes and questionnaires.

Zinc will help alcohol-afflicted HIV-positive residents of St. Petersburg

By all criteria, 254 people approached. They were randomly divided into two equal groups. Members of one daily for 18 months took capsules with zinc gluconate (15 mg for men and 12 mg for women). Representatives of the second group with the same frequency and duration took indistinguishable form of placebo. All the capsules were supplemented with riboflavin, which changed the color of urine for 24 hours after its administration. It was necessary to make sure that the person actually took the medication given to him before coming to the examination. They should have been passed to each subject at the end of the 6th, 12th and 18th months of taking capsules. Additional visits to the clinic were also not forbidden: 500 rubles were paid for each such visit. For basic surveys, participants were paid 1,250 rubles each.

During the main receptions, the patients noted the presence in the blood of biomarkers of microbial translocation (the spread of bacteria and their toxins into the blood and lymph nodes leading to systemic inflammatory responses), viral load and immune status (the amount of RNA of the immunodeficiency virus and the number of CD4-lymphocytes in the blood) . All these parameters allowed to assess the state of the immune system of the participants in the experiment. Also, doctors evaluated the risk of cardiovascular disease (the concentration of “bad cholesterol” in the blood) and death from other factors.

In patients from the group given capsules with zinc gluconate, the viral load was more stable than those who were prescribed a placebo. The level of substances – markers of microbial translocation – in their blood also became lower, as well as the concentration of “bad cholesterol”. These patterns were observed provided that the patient regularly took zinc preparations given to him.

Thus, zinc gluconate can be a cheap and effective means of improving the condition of alcohol-afflicted HIV-positive people. Unfortunately, neither the authors of the study, nor Russian doctors in general, hope to significantly reduce the proportion of people who regularly consume alcoholic patients infected with the immunodeficiency virus. All available measures to combat alcoholism in this category of citizens have extremely limited effectiveness. Therefore, it is easier to maintain the state of HIV-positive and alcohol-dependent people with zinc compounds, that is, to carry out palliative therapy to some extent.

Whatever it was, the search for such funds is especially relevant for Russia. There are two main reasons for this. First, the number of people infected with HIV in our country has exceeded one million people for several years and continues to grow. Secondly, the annual consumption of alcoholic beverages per capita in the Russian Federation is one of the largest in the world. It is vitally important to raise the survivability of the victims of both these epidemics.

Migraine is a legacy of the ancient Europeans

Migraine is a legacy of the ancient Europeans

The first Briton probably already suffered from migraine. History Museum

If you have a migraine, then most likely you are a descendant of the first Europeans. Migraine helped ancient people after migrating from Africa 50,000 years ago to overcome the cold and adapt to European weather.

This conclusion can be drawn from studies conducted by scientists from the Max Planck Institute in Germany.

According to scientists, the outcome of Homo sapiens from Africa was accompanied by genetic mutations that helped early people adapt to low temperatures. In particular, mutated TRPM8, the only known gene that is responsible for the reaction to cold.

Researchers have found that over the past 25,000 years, the European version of the gene has spread rapidly among residents of northern latitudes. For example, today it is found in 88 percent of the inhabitants of Finland and only 5 percent of people with Nigerian ancestry.

This change may have had the unfortunate consequence of increasing the incidence of these severe headaches in some populations, researchers at PLOS Genetics report.

Previous research has already established that people with an African version of this DNA fragment are less susceptible to migraines than people with a mutated European version of TRPM8.

According to the scientists’ assumption, the connection of mutation of the gene with migraine seems to be a side effect. Researchers recognize that migraine is still a mystery, as well as its relationship TRPM8.

Migraines, characterized by a pulsating headache, affect millions of people. They are difficult to treat, because it is not known what causes them. The majority of children (72.6%) inherit migraine from their mother, only 20.5% of cases are transmitted on the paternal line.

According to the World Health Organization, migraine is almost not common in Africa and has the highest rate in Europe.

From the new study, we can conclude that migraine is the first pan-European human trait of the reasonable.

Other signs – pale skin, blond hair and blue eyes – later became stronger. Ancient people began to lighten about 40 thousand years ago as a result of mass migration from Africa to Europe. However, the analysis of the genomes of 83 prehistoric Europeans in 2015 showed that the population in Europe about 8,000 years ago was still mixed and varied. In central and southern Europe, including Spain, Luxembourg and Hungary, ancient hunter-gatherers had darker skin. In the north of Europe, light-skinned Europeans already predominated.

These conclusions are confirmed by the reconstruction in March of this year of the appearance of the first Briton, whose skeleton of 10 000 was found in southern England. The study showed that he probably had brown hair, dark skin and light eyes.

Physicists have learned to move nodes along the DNA molecule

Physicists have learned to move nodes along the DNA moleculeA. R. Klotz et al. / Physical Review Letters, 2018

American biophysicists have learned to control the movement of nodes along a single DNA molecule using a stretching polymer electric field. If the parameters of the molecule’s stretching are properly selected, it is possible to move the node along a molecule several micrometers long in about a minute, scientists write Physical Review Letters.

Almost all long polymer molecules, including DNA molecules, can be found nodes. They appear on the molecule in a natural way, and their number may depend on the type of molecule and the presence of auxiliary compounds in the cell. For example, in mammals, certain enzymes from the topoisomerase class are responsible for tying and untangling nodules on DNA molecules. Since the presence of nodes on the DNA molecule can lead to errors in the replication or transcription process, they can be used as one speed regulators and analysis mechanisms. And for example, in the case of nanoporous sequencing, the presence of nodes serves as one of the factors that slow the process of passage of the molecule through the pore, which makes it possible to increase the resolution of the method.

American biophysicists from the Massachusetts Institute of Technology, led by Patrick S. Doyle, discovered that if a DNA molecule is in an extended state, then the node can be controlled by it. This effect scientists noticed, placing the molecule with a knot tied to it in a microfluidic device, in which the channels were connected at a right angle, forming a T-shaped joint. At this junction, by using an electric field (the lines of tension that were directed along the channel), it is possible to fix and stretch the polymer. To do this, the center of the molecule is placed at a zero-field point located in the center of the junction, and its ends are pulled by the field in opposite directions due to electrophoresis, which stretches the entire structure along the channel wall.

Physicists have learned to move nodes along the DNA molecule

Above: a microchannel-trap circuit for stretching DNA. Black dotted lines show the lines of electrostatic field, red line – the DNA molecule. Bottom: successive micrographs of a molecule with a node moving along it. Scale ruler – 5 micrometers

Alexander R. Klotz et al. / Physical Review Letters, 2018

After the state of the tinted molecule about 80 micrometers in length, the scientists were followed by fluorescence optical microscopy. On the molecule was located one simple node, which could be clearly seen on microimages. It turned out that the electric field in the microchannel not only stretches the DNA, but also leads to the movement of the node along the polymer from the center to the edge. In this case, as soon as the node reaches the end of the chain, it is untied.

Physicists have learned to move nodes along the DNA moleculeMovement of the node on the DNA molecule from the center to the edge

Scientists note that it is impossible to describe the mobility of a site only by the action of an electrostatic field, so to explain the nonlinear dependence of its coordinates on time, the authors considered the balance between Brownian motion and the velocity gradient.

Because of the peculiarities of fixing the molecule in such a “stretching trap” along its length, the fluid velocity changes, creating an analog of the shear flow with zero velocity in the middle of the molecule. Therefore, the mobility of a site on a molecule is characterized by the Weissenberg number – the ratio between the relaxation time and the force gradient: if the maximum tensile force is large enough compared to the force of Brownian diffusion, then the node moves translationally in a known direction, and in the case of predominance of Brownian motion its motion has a pronounced diffusion character .

It turned out that as the Weissenberg number increases, the motion of the node slows down. The optimal range is the parameter (when the molecule can be stretched so that it does not tend to curl up into a spiral, but the knot is controlled and moves quickly enough) is about 0.9 to 1.5. The obtained quantitative experimental data of biophysics was also confirmed by computer simulation of nodes of several different topologies.

The authors of the paper note that the method proposed by them will help to quickly get rid of those nodes that interfere with the experiments, and also controllably move the DNA nodes that are used for useful purposes.

If in a linear polymer molecule the node is fairly easy to untie, simply moving it to the edge of the molecule, then in the case of a node in a closed polymer chain, it can not be disposed of. The most complex of these artificially synthesized knotted knotted molecules consists of 192 atoms and includes 8 crossings. Similar molecules with a topological link are made from DNA molecules: for example, recently one of such structures was converted into a nanomotor, which synthesizes RNA and jumps over the surface.

In Hawaii lava flows along the roads

Residents of the Hawaiian Islands managed to shoot and put on the Internet a rare footage: on the Big Island Kilauea volcano, and now the roads and forests on the island are literally lava.

In Hawaii lava flows along the roads

In Hawaii lava flows along the roads

On the largest island of the Hawaiian archipelago, the Kilauea volcano erupts; on Thursday, the inhabitants of the island felt a five-point earthquake, after which a pink cloud of ash and smoke rose above the crater of the volcano.

Short-lived plume of ash from Pu"u «Ō"ō captured the an HVO overflight. https://t.co/Lt84auZeSP pic.twitter.com/ 0xQgH1FPEI

– USGS Volcanoes (@USGSVolcanoes) May 3, 2018

Then, cracks began to form in the ground, and the lava flowed through forests, roads, and even climbed up to residential areas. Due to the threat of destruction and high concentration of sulfur-containing gases, the state authorities evacuated fifteen hundred people. In a video shot by Maya Stenbeck on Friday, you can see how lava, hissing and gurgling, rises from the crack in the asphalt.

Another inhabitant of the island, Jeremiah Osuna, took a lava flow from the drone, making his way through the forest. He did it shortly before the flights were forbidden over the island, including unmanned aerial vehicles.

Kilauea is one of the largest shield volcanoes in the world. Shield volcanoes do not take the form of high cones with a vent at the top; They are more like a layered pie, lined with multiple outpourings of lava. They are characterized by a large diameter of the caldera, gently sloping walls and a lot of cracks that sometimes appear for many kilometers from the caldera.

Scientists: fasting for 24 hours slows down aging

Scientists: fasting for 24 hours slows down aging

pixabay.com

Fasting during the day can slow the aging of intestinal stem cells. To such conclusions came the scientists from the Massachusetts Institute of Technology.

Biologists conducted a series of experiments in mice, which "starved" 24 hours. After that, the scientists studied intestinal cells, which were grown as a three-dimensional cell culture. It turned out that the cells began to break down fatty acids instead of glucose to produce energy.

This had a bad effect on their work, as well as on the ability of tissues to regenerate. PPAR factors that regulate the activity of genes in the metabolism of fatty acids were involved in the process.

Compound, "including" these factors, acted on the body as a diet. The effect turned out to be beneficial: the intestinal cells began to rejuvenate.

Scientists came to the conclusion that short-term fasting is beneficial for the body. Slowing down the aging that it causes, in turn, reduces the risk of intestinal tumors or organ damage to infections.

4 books about the digital afterlife

Books Knowledge Bank

What to read about digital immortality

4 books about the digital afterlife

unsplash.com

PostNauka continues to talk about modern technologies and their impact on our life in the “Knowledge Bank” project, prepared jointly with the Corporate University of Sberbank.

Since the beginning of 2010, experts in the field of communication theory, sociologists, philosophers and developers of human-machine interfaces have actively engaged in discussions about the afterlife of man. Of course, representatives of social and humanitarian knowledge have long studied the practice of dying, various aspects of rituals of sorrow, mourning, mourning. And the historians of religion, as well as representatives of those or other denominations, were very aware of the strategies of confessional “treatment” of death. But at the beginning of the 21st century, digital technologies were gently invaded the everyday, private and professional, public spheres of many. And it quickly became clear that the “figure” can offer solutions not only for managing the quality of life of a person, but also for planning death.

Strictly speaking, the digital environment generally does not know death as a physical and simultaneously existential dimension of being. It can die that is alive, within the limits of digital interactions it is a matter of data transactions. Therefore, death in the digital world exists predominantly in the format of obsolescence of “things” and services (which cease to function properly), like the representation of former conventional models of dealing with the dead, communication around the event of dying in the new online reality and as a game in the social life of postmortem for example, by constructing chat bots based on the data of the deceased). However, even this understanding of the “artificiality” of digital death does not prevent interface designers, for example, to think about turning the online world into a “tanatosensitive” system whose interaction will allow people to feel relatively comfortable, and even in such crisis situations as the experience of leaving another . Researchers, on the other hand, often use the old vocabulary to critically consider those new tools and behaviors that are becoming more common for users.

4 books about the digital afterlife

Carroll E., Romano J. Your digital afterlife: When Facebook, Flickr and Twitter are your estate, what’s your legacy? – New Riders, 2010

One of the first books, written by designers and researchers, since 2008 has studied only the emerging postmortem digital community. Some of the theses of the book are reflected on the original site of its authors, while others are more elaborate and detailed reflections on the legal, financial problems of the functioning of the online digital life afterlife (digital afterlife). Since at the time of writing the online immortality cases still seemed marginal in the digital life fields, the authors begin by describing the specifics of the digital presence itself.

4 books about the digital afterlife

Reasoning about the communication services, which are more often used by users, they come to talk about a digital heritage consisting of all consciously or accidentally left traces. Postal services that store data about transferred documents, accounts in online libraries, where the links to favorite movies, serials, photos and books, computer games (where on the linked accounts, by the way, can lie real or convertible into real money) are stored, the devices themselves – all these are elements of a personal user heritage that would be good to transfer to descendants. What for? Well, because their value is not only significant in the virtual space, but also quite visible within the mixed online-offline daily routine. And how can you convey all this? Here there are problems. Far from always the system of law stipulates the possibility of inheritance in such cases, therefore there is some arbitrariness of the services and their owners. The creators of software often independently regulate (not) the possibility of relations between testators and heirs, and these rules have to be reckoned, because it is they who determine the security features of those personal data archives that constitute fragments of our identities designed online.

The situation of such dependence on the engineers and architects of the software looks somewhat risky. It is enough for the business owner to decide whether to stop the work of the platform or change its algorithms, how users can lose access to the archives or face inconvenience in the event of access to them. Therefore, the authors propose to plan their posthumous digital existence, the more so that the first services of this kind at the time of writing the book have already worked. Of course, these recommendations are practical in nature. But, probably, for many of us, concerned about the preservation of their data (for themselves and their descendants), it is primarily the desire to take control of these assets. And then plunge into the discussion of the fundamental foundations of digital death and immortality.

4 books about the digital afterlife

Maciel C., Pereira V. C. (ed.). Digital legacy and interaction: post-mortem issues. – Springer Science & Business Media, 2013.

A close look at the table of contents gives the impression that this collective monograph was created based on Borges’s encyclopaedia called “Celestial Emporium of Beneficial Knowledge.” Probably, this experience is connected with a variety of declared topics, which ideally should mark out the diversity of possible research problems.

So, talking about the digital legacy of dead users, the authors are concerned with the specifics of developing services that are fundamentally sensitive to data security problems, they talk about how these platforms work with the remembering and grieving practices that their clients want and / or can show, and even do not miss It’s worth noting that all these questions often seem not to require special discussion – at least within the communities of young users who are used to remote communication and seem not too sensitive to zmozhnosti posthumous communication with the dead friend. Parallel to the narrative, there are stories about the impact of digital technologies on real burial processes, in general funeral industry. And a constantly emerging vignette is a discussion about the role of post / transhumanism in the conceptualization of a person’s social death, whose electronic emanations may well continue to interact actively with the survivors.

One of the big claims to the monograph is the actual equalization of the offline and online identities of the user. Still, our digital accounts, used in the everyday situation as digital versions of us, are specially designed “things.” At least, they are the managers and programmers of online services. It would be a great assumption to compare their attitude to their clients with the behavior of the heroes of the sci-fi movie “The Matrix”, who had the opportunity to recognize in the lines of code the emanations of people in the machines created by reality. But, what exactly is true in this metaphor is the cynical ability to see in avatars only a collection of data. In this regard, talk about the need to maintain digital “posthumous privacy” (that is, be concerned about the ethics of manipulating the accounts of the deceased) look slightly divorced from the realities of established business models. But in any case, should be conducted, because these models in the context of the urgency of the problem of social immortality on the web are not exactly the only possible.

4 books about the digital afterlife

Moreman C. M., Lewis A.D. (ed.). Digital Death: Mortality and Beyond in the Online Age. – ABC-CLIO, 2014

4 books about the digital afterlife

As in all the other books listed above, the authors begin their narrative with an appeal to popular culture. Images from the series help to describe the reality of life on the web as something potentially close to any reader. Once something appears in the series, it means that this is a fact that appeals not only to scientific, but also to “naive”, everyday criticism. However, unlike previous works, this is formed as a clear set of problem fields, which are often consulted by experts of the emerging research field Digital Death Studies. According to the authors of the collective monograph, in general such fields are practices of online grief, the representation of which is helped by multiplying communication services, features of online memorialization of the deceased, the problems of inheritance of their digital property and the reflection of the fact of death in different virtual spaces.

The description of the inheritance of digital data may seem to the reader familiar with previous books, a hackneyed topic. Although, I will note that the discussion of digital obituaries, cemeteries, scenarios of virtual remembering of close and social values ​​of “ghost” accounts belonging to the deceased, is evidence of non-trivial approaches that indicate a greater degree of critical reflection on phenomena. Still, the authors of the essay try to describe the strategies of the online life of the deceased and their loved ones on specific platforms. For example, the authors try to answer the following questions: “How do they report about death on Twitter?”, “How do they grieve about death on Facebook?”, “What kind of photos are laid out in Instagram?”, “Can people be counted, condolences on any occasion, supporters of a new dark tourism or bearers of ostentatious virtue? Or do they play in grief? “In turn, the study of the depiction of death in video games, implemented in the third chapter, raises the question of how game designers process conventional, cultural attitudes toward death to increase user engagement, empathy (note, game characters and game events).

Finally, the book is useful because its authors and editors rely on the emerging research tradition and do not hesitate to mention colleagues working in the same field, including offering quite practical recommendations to a wide range of readers. As we get acquainted with the monograph, the reader sees references to the work on the theories of futurists and programmers regarding the digital posthumous status of users, a book about digital thanatology intended for specialists in the field of education and psychological support, and a guide for those who have lost loved ones and is looking for including online – Ways to survive your grief.

Arnold M. et al. Death and Digital Media. Routledge, 2018

The most recent book of the collection, published in 2018. Some of its authors may be known for the article of 2015 devoted to the study of hashtag and other “languages” of online platforms, which are used to publish death reports. In the same text, the researchers decided not to limit themselves to social media analytics alone, but to look at modern ways of understanding death as an event, in relation to which a whole range of operational, tactical and strategic decisions have been developed that in a significant number of cases involve access to digital services.

In particular, the authors share all possible products and services offered by agents, somehow related to the funeral industry, to those that need to worry about beforehand (pre-need, on the eve of death) that help to solve the problems of specific death (at-need) and that help regulate some issues later (post-need). This simple classification allows you to look at, for example, the activity of concrete funeral bureaus in social networks, the technology of online death planners, permanent online wake-ups, performed on the personal pages of the deceased in social networks. As a result, the authors manage to outline several aspects of the work of digital media with the phenomenon of death.

First of all, they are interested in the new dimension of “humanity”, the identification grounds associated with the intuition of the discrepancy between physical and social death among modern users. Can we say that in the zombie accounts that continue to lead a social “life” after the death of the owners, is there something “human”? Then the authors undertake to clarify how the rules of the digital world are correlated with the existing legal systems, customs and rules governing the rituals of death and mourning. Another problematic issue is the question of the possibility of quality aesthetic, design solutions to help the mourners live the event. For example, virtual cemeteries in one form or another – is this a solution for those who want to somehow “see” the deceased? Finally, the authors are interested in the problem of new temporal and temporal (spatial) characteristics of death and farewell to the departed. Traditional rituals offer solutions on how, where and when to burial, how often you can visit the deceased, how many, to whom and how exactly to keep mourning. But the “figure” destroys all these conventions or, perhaps, comes up with their own versions of the rites.

About how much these solutions can be considered workers in the era of digitalization, in the conditions of total publicity, we all – researchers, business representatives, lawyers and generally users – will find out in the near future. For example, at a time when the “population” of popular social networks, blog platforms and messengers will largely consist of “ghosts.”

candidate of cultural studies, associate professor of the Department of Cultural Studies and Social Communication of the Russian Academy of Science, Assistant Professor of the Department of the USPS MShSEN, Director of Studies of the Research Bureau for Digital Humanitarian Studies “CultLook”

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4 books about the digital afterlifeThe science of oil

At the source of the creation of all civilizations of the Indians of America stood 250 Siberians

At the source of the creation of all civilizations of the Indians of America stood 250 Siberians

The conjecture that the real founding fathers of America are natives of modern Russia, so excited the minds of scientists that immediately after the fall of the Iron Curtain, the Americans organized an anthropological expedition to Siberia

Of course, Columbus is wrongly called the pioneer of America. Long before him, this part of the world was discovered by people who represented the peoples living today on the territory of Russia. Only in contrast to Columbus, they followed the precepts of Lenin, went the other way. An international group of scientists with the participation of the professor of anthropology of Kansas University Michael Crawford in 2015 published a fundamental study in which she proved that the ancestors of modern Indians entered America from the “black entrance”. They did not need to cross the Atlantic at all. At the height of the last ice age, about 23,000 years ago, they crossed the Bering Isthmus from Chukotka to Alaska on dry land (there they spent 8,000 years in isolation and moved into the interior of the continent only when the climate warmed and the passageways opened in the ice sheets). Genetic studies have shown that all the indigenous Indians of America are descended from a single population of Siberian inhabitants.

In the new study, the scientists calculated the size of this group of first settlers.

The Chukchi, the Buryats, or George Washington?

The conjecture that the real founding fathers of America are not George Washington and Benjamin Franklin, but natives of modern Russia, so excited the minds of scientists that immediately after the fall of the Iron Curtain, the Americans organized an anthropological expedition to Siberia. The head of the first team of scientists, who in 1989 started to study the genetic code of the peoples of Siberia, was just Michael Crawford.

Even then, anthropologists collected DNA samples from representatives of 10 nationalities: the Altaians, Aleuts, Buryats, Chukchi, Evenks, Ostyaks, Itelmen, Kalmyks, Koryaks and Tuvinians. In the current study, scientists compared certain areas of the DNA of Siberians with the genetic markers of ethnic groups living in South and Central America: Ace (Paraguay), Bribri, Guatuso, Guaymi (all – Costa Rica), Lengua (Argentina), Quechua (Peru), arar, vivay, chavant and zuruha (Brazil).

Scientists were interested in the question: how great was the first wave of migrants from Siberia, whose descendants colonized America? Figuratively speaking, the idea was to roll back the “time machine” with the help of genetic analysis methods, when the genetic differences between the representatives of these tribes were minimal.

Get into the bottle neck

In the course of the study, it became clear that there was one migration wave, and the genetic diversity in the Indigenous tribes was very small. This is due to the fact that at some point the population survived the effect of the “bottleneck”. This is called the reduction of the gene pool, which occurs as a result of a critical decrease in the number of biological species. A classic example of this effect is the cheetah population. It is believed that as a result of a catastrophe, only one female and male survived, which became the progenitors of all living cheetahs. Due to the lack of genetic diversity in predators, a high level of accumulation of harmful mutations is observed, which reduces the survival of the species as a whole. Through this “bottleneck” at one time managed to get through and all of humanity. Scientists suggest that at some point the ancestral population of Homo sapiens was reduced to a group of 2-5 thousand people. However, the low genetic diversity of American Indians is due to other reasons.

Pyramids and drawings of Nazca were created by our people

– Based on archaeological evidence, we know that Central and South America have been inhabited for the past 15 thousand years. – says Michael Crawford. “Using computer modeling of isolation and migration processes based on 100 million generations, we managed to calculate the size of the founder population – according to our estimates it was only 250 people! Genetic evidence helps to restore a fascinating picture of how the New World settlement unfolded. Only a couple of hundred people have given life to numerous tribes and peoples, whose number today reaches 40 million people! Naturally, they did not say to each other: “And let’s go and discover new lands!” It was about the division of groups of hunters and gatherers. Probably, the ancestral population was divided into groups of about 50 people. When the conditions became favorable, the birth rate grew, after a while part of the community, not to crowd, went to new land. There, in turn, again there was a small demographic explosion, and then the division of the group. Thus, for 15 thousand years, immigrants from Alaska reached Argentina, while the development of the continent in different regions formed tribes with their new language, culture, way of life.

It’s amazing that the Iroquois and Mohicans are heroes of adventure novels; Aztecs and Maya – the creators of highly developed civilizations; Indians Nazca – the authors of amazing giant drawings – they were all far from foreign to Russia people.

Scientists have found a connection between starvation and aging cells

Scientists have found a connection between starvation and aging cells© Fotolia / evgenyatamanenko

MOSCOW, May 4 – RIA Novosti. Biologists at the Massachusetts Institute of Technology found that fasting improves the regenerative capacity of intestinal stem cells, the MedicalXpress portal reports.

Scientists have found a connection between starvation and aging cells

Scientists have proved the relationship between fasting and hair growth

Scientists conducted an experiment involving mice: rodents were not fed for 24 hours, after which scientists extracted stem cells of the intestine and raised them in an artificial way.

As it turned out, after starvation in the cells there was a change in the energy metabolism: instead of glucose, they switched to the splitting of fatty acids. This greatly stimulated the process of the appearance of new cells – the process of their rejuvenation accelerated in half.

Scientists hope that this study will contribute to the development of a drug with a similar effect that will help elderly people suffering from gastrointestinal infections and oncology after chemotherapy.

The age of will can not be seen, or Why a person does not control his behavior

The age of will can not be seen, or Why a person does not control his behavior

© RIA Novosti Illustration. Alina Polyanina, Depositphotos / Milous

MOSCOW, May 1 – RIA Novosti, Alfiya Enikeeva. In the last few years, the notion of the human brain has changed dramatically. Scientists have proved that the center of rational thinking and self-control is in the frontal lobe of the cortex, and hormones control mood and behavior. RIA Novosti understands whether people are capable of conscious decisions or their actions – the result of biochemical reactions in the brain.

The age of will can not be seen, or Why a person does not control his behavior

The human brain is found "appraiser" decisions

In 1979, an American psychologist, Benjamin Libet, experimentally showed that brain regions responsible for decision-making are activated earlier than a person makes his choice. This is about two hundred milliseconds, but they transferred the question of free will to the natural-scientific plane. The experiment of Libet was criticized a lot, however, reproduced dozens of times, he gave the same results.

The next attempt to verify Libet’s conclusions was made in 2016 at Johns Hopkins University (USA). The scientists placed the subjects in the MRI unit and asked to arbitrarily translate the view from one part of the screen to the other (the monitor was inside the device). Each movement of the eyes was recorded in the picture. When a person changed the direction of the view, the parietal lobe of the brain, responsible for implementing the solutions, became more active. However, two sections of the brain – in the frontal lobe of the cortex and in the basal nuclei – were excited before the gaze began to change direction. It turns out that the decision about the action ripens in the brain before the person realizes his choice.

Love, friendship, hormones

Trying to explain this, neuroscientists have suggested that the chemical processes in the brain control the mood and behavior of a person, including decision making. The human brain weighs about one and a half kilograms, its volume is on average 1,500 cubic centimeters, but we think only a few centimeters of the cortex. The rest of the neural tissue deals with the processing of non-verbal information coming from the external environment and from the body itself. Therefore, hormones synthesized in the ovaries, adrenal glands or other glands of internal secretion through their metabolites (products of chemical transformation in the body) affect the brain and thus determine human behavior.

Scientists from Russia have found out how depression changes the work of the brain

So, stress hormones – adrenaline, norepinephrine and cortisol – inhibit digestion and improve the blood supply of muscles, cause a person in a difficult situation to act on one of two stable behavioral patterns: "hit or run" and "zam". The level of another hormone, progesterone, whose main function is to prevent uterine contraction during pregnancy, reduces anxiety of the pregnant woman and thereby protects the embryo from harmful hormones of stress. This same hormone is responsible for mood swings in women, when at the end of the menstrual cycle it becomes less in the body.

Another predominantly female hormone, oxytocin, enhances the production of breast milk, awakens parental feelings for the baby. In addition, it is associated with the establishment of social contacts and the level of anxiety, so they are trying to use it to treat depression. For example, scientists from the St. Petersburg University in the experiment found that oxytocin returned rats subjected to uncontrolled stress to a normal state, while conventional antidepressants did not help.

Maternal share

Sexual orientation, intellectual potential, autism, schizophrenia, aggression are laid in the embryo under the influence of the level of hormones in the mother’s body, says Dutch neurophysiologist Dick Svaab, author of the book "We are our brain".

Play, a hormone: why men are more calm, and women see better

Thus, a high level of testosterone during pregnancy, the use of the future mother of nicotine, amphetamines and some synthetic hormones can lead to a homosexual orientation of the female child. And the boy’s sexual behavior depends on how many brothers he had. The fact is that with every new male embryo the female body produces more and more substances that counteract its hormones.

The articles of Svaab and his colleagues, published in leading scientific journals, were taken into account when drafting legislation in the UK and the European Court of Human Rights, when transsexuals defended the right to change sex in a passport. Another example of the practical application of the results of scientific research in the field of neurobiology is described by Professor Nike Farahani of the University of Duke (USA). Her research team analyzed more than 1,500 sentences passed in the United States from 2005 to 2012, and in about half of them found references to neurobiological data when the defense party tried to prove that the defendant’s brain had made them commit a crime.

According to Michael Gazzaniga, a neuropsychologist at the University of California at Santa Barbara, the fact that brain biochemistry affects behavior does not relieve a person of responsibility for the deeds done. In the book "Who is in charge?" he writes that at the level of one person’s brain, free will is a myth created by evolution, but at the level of interaction between people it is a real thing. It is impossible to fully predict the behavior of people in relation to each other, and due to this there is freedom of will that allows the human brain to constantly develop and improve.

The age of will can not be seen, or Why a person does not control his behavior© Depositphotos / focuspocusltd