- Leonid Luneev
- BBC
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Among the scientific news of the week:
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- Bilingualism – salvation from dementia
- How we quench our thirst without taking extra sips
- Single-celled hunters who get a virus for one tooth
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Exercise for the brain, or how to hit Alzheimer’s with bilingualism
Photo author, Getty Images
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Communication in two or more languages is not a problem for Barcelona residents
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Knowledge of two or more languages not only enriches us, allows us to learn another culture, share our thoughts and understand the world deeper. As scientists from two Spanish research centers, the Open University of Catalonia (UOC) and the University of Pompeu Fabra (UPF), have found, the active use of two languages at once can protect you from the cognitive disorders associated with aging.
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The fact that the use of two languages to some extent protects people from senile dementia has been known for a long time.
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“The prevalence of dementia in bilingual countries is 50% lower than in regions where the population speaks only one language,” said the head of the latest study (published in Neuropsychologia), UOC Professor Marco Calabria. they wanted to reveal the mechanism of resistance to cognitive disorders in a mild form, as well as Alzheimer’s disease, which exists among bilinguals, and to learn about the dependence of the work of such a mechanism on the degree of proficiency in two languages. “
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The researchers chose the residents of Barcelona as volunteers, since almost everyone there is equally proficient in Spanish and Catalan, and among them were both perfectly healthy people and those who suffer from dementia or memory loss.
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“We found that if people with higher levels of bilingualism were diagnosed with mild cognitive impairment, it was at a noticeably later age than those who were passively using one of the two languages,” Calabria explains.
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The professor himself believes that the constant use of two languages and switching from one to the other serves as an excellent exercise for the brain.
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According to the researcher, such linguistic gymnastics is also associated with other cognitive functions – for example, with the executive system of the brain, which turns on when we perform several actions at the same time. It also makes it easy to switch from one language to another, without confusing them in speech.
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So when the executive system is impaired in a cognitive disease, the bilingual brain has an effective alternative system for solving the problem. Moreover, the more actively both languages are used and the better a native speaks them, the more reliably it is protected in neurological terms.
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In fact, active bilingualism serves as an important factor in delaying the symptoms of mild cognitive impairment – the preclinical Alzheimer’s phase.
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Scientists are now hoping to find out if speaking two languages helps stop the onset of Parkinson’s and Huntington’s diseases.
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Thirst: why we know when to stop
Photo author, Getty Images
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Thirst – this feeling is familiar to everyone, and everyone knows how to quench it, how many sips of water, preferably cold, need to be done to make it go away.
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However, until now, no one has been able to figure out exactly how thirst is quenched.
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As a group of scientists led by Chris Zimmerman from the Institute of Neurology at Princeton University found out, in the process of drinking, the brain continuously receives signals about the concentration of water in the blood, mouth, throat, intestines, and the neurons responsible for thirst instantly assess the degree of saturation of the body with water and, accordingly, the level of thirst.
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“Thirst is not just a response to dehydration, as classical models suggested, but dynamic regulation that predicts in real time when the right water level will be reached,” explains Zimmerman.
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Indeed, since the 1950s, all textbooks have presented a very simple theory that there is a kind of osmosensor in the brain – a site that regulates the level of water in the blood and tells when and how much to drink in order to maintain this level.
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According to Zimmerman, this model was not able to answer the simplest question: how does water instantly quench the feeling of thirst, although it has not yet had time to be absorbed into the blood?
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And then again the mice came to the rescue, which in the matter of thirst practically do not differ from people. Using fiber-optic technology, scientists led by Zimmerman were able to measure the calcium balance in the brains of mice and see how a separate group of neurons responsible for feeling thirst reacts.
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As it turned out, these neurons not only have information about the level of water in the blood, but also receive additional signals from other parts of the body, including from the mouth, esophagus and stomach, instantly making up the big picture, so that a mouse (or a person) is not yet drunk, knows when to stop.
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Plankton We Underestimated
Photo author, Getty Images
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Either you eat, go eat you – this is the harsh law of nature, which operates in all corners of the biosphere. Only viruses have not yet fit into this picture. And this despite the fact that the viral biomass in soil, atmosphere and water is tens of millions of tons. Has no one still coveted this wealth?
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It looks like scientists have found the answer in the waters of the Gulf of Maine off the east coast of North America.
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There are two types of unicellular organisms living there, which, apparently, are not averse to eating even such a dubious delicacy as viruses. After examining the insides of these first virrophages (that is, the eaters of viruses), the researchers selected all the DNA found there and made a real card index on them.
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As you might expect, most of the DNA belonged to the plankton itself, 19% were bacteria that were swallowed by this plankton, but half of the card index was made up of fragments of genes from 50 or more different viruses.
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For the most part, these were gene sequences of bacteriophages – viruses that invade bacterial cells and multiply there, so that plankton could get them in the form of “food additives” to the main food.
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But in the case of choanozoic and picozoic protozoa, researchers sometimes could not find any remnants of bacterial DNA at all. And if the dinner did not take place, how could the bacteriophage genes get into the plankton cells?
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And although all this evidence of a snack with viruses may look indirect, you must admit that if you found your child soiled in chocolate, and there was a wrapper from him lying nearby, then you will have every reason to be suspicious.
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