|Российская наука и мир|
(по материалам зарубежной электронной прессы)
В преддверии второго саммита Россия-Африка, который состоится в 2022 году в столице Эфиопии Аддис-Абебе, 24-26 мая в Москве прошла XV международная конференция африканистов «Судьбы Африки в современном мире». Организаторами выступили Институт Африки РАН совместно с фондом «Росконгресс».
As part of the preparations for the second Russia-Africa summit, the Institute of African Studies in conjunction with the Roscongress Foundation and supported by TASS News Agency organized and held the 15th conference of Africanists entitled ‘The Destinies of Africa in the Modern World’ in Moscow. The conference opened on the eve of the Africa Day celebrated on May 25.
This year’s conference, and other related events held online/offline format, was especially significant, as it was an important step in preparation for the second Russia-Africa summit, which will take place in 2022 in Addis Ababa, Ethiopia.
On May 24, the conference opened with the plenary session moderated by Director of the Institute for African Studies under the Russian Academy of Sciences, Professor Irina Abramova.
This session was an opportunity for the leaders of Russia and the African Union (AU), representatives of business and scientific community to discuss the current agenda of the Russian-African cooperation and the required steps to strengthen and expand a mutually beneficial partnership on an international scale.
The delegates were greeted by the Russian side, represented by Deputy Chairman of the Federation Council of the Federal Assembly of the Russian Federation Konstantin Kosachev, Deputy Chairwoman of the State Duma of the Federal Assembly of the Russian Federation Olga Timofeeva and TASS Director General Sergei Mikhailov.
The African side was represented by Commissioner for Human Resources, Science and Technology at African Union Commission Sarah Anyang Agbor and President and Chairman of the Board of Directors of the African Export-Import Bank (Afreximbank) Dr. Benedict Okey Oramah.
The plenary session was attended by Special Presidential Representative for the Middle East and Africa and Deputy Foreign Minister Mikhail Bogdanov, Deputy Minister of Science and Higher Education of the Russian Federation Natalia Bocharova, Deputy Minister of Industry and Trade Alexey Gruzdev and Head of Rossotrudnichestvo Evgeniy Primakov.
Vice President of the Russian Academy of Science Academician Yuri Balega, Director of the Institute for African Studies of the Russian Academy of Sciences Academician Alexey Vasiliev, Senator of the Russian Federation and Chairman of Coordination Committee for Economic Cooperation with African Countries Igor Morozov, Russian Export Center CEO Veronika Nikishina, Chairman of the Association of Economic Cooperation with African States (AECAS) Alexander Saltanov and Managing Director for Multilateral Cooperation and Integration of the Russian Union of Industrialists and Entrepreneurs Sergey Mikhnevich also attended the session.
"First of all, I would like to thank the Russian Academy of Sciences for organzing this type of forum and to express my gratitude to Presidium Member of the Russian Academy of Sciences, Director of the RAS Institute for African Studies Olga Abramova, it is largely thanks to her that we are opening this event today. It is really important that the academic circles independently assess the condition and the perspectives of our relations with African countries," said Special Presidential Representative for the Middle East and Africa, Deputy Foreign Minister Mikhail Bogdanov.
On the opening session, the African side was represented by the Dean of the African Diplomatic Corps, Ambassador Extraordinary and Plenipotentiary of the Republic of Cameroon to the Russian Federation H.E. Mahamat Paba Sale and Rector of the Free University of Kinshasa, Professor Jean Michel Kumbu.
The face-to-face plenary session attended by representatives of state administration of Russia and of African countries was the starting point for further discussion by the scientists and experts. Within the three days (May 24-26), 48 sections provided opportunities for over 500 leading researchers and specialists from all continents to talk online about a wide range of topics related to Africa.
The closing session of the conference moderated by Deputy Director of the Institute for African Studies of the Russian Academy of Sciences, Professor Dmitri Bondarenko. The session also featured presentations by Professor of University of South Africa Andreas Velthuizen, Honorary President of the Institute for African Studies of the Russian Academy of Sciences Alexey Vasiliev and Deputy Director of the Institute for African Studies Leonid Fituni.
The participants unanimously praised the high level of the conference organization and its high academic and applied significance. The conference outcomes and results will be taken into account for preparation for the forthcoming summit planned next year in Addis Ababa, Ethiopia.
Copyright © 2020 Modern Diplomacy.
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В Томском политехническом университете определили точные математические параметры процесса распыления воды. Это может пригодиться как при тушении пожаров, так и в различных отраслях промышленности, где используется распыление воды с последующим испарением.
Scientists from Tomsk Polytechnic University (TPU) were able to improve industrial methods of spraying water by creating a complete mathematical description of this process.
According to the scientists, the data obtained will help improve fire extinguishing techniques, as well as a number of processes in the petrochemical industry. The results were published in the Powder Technology academic journal.
Spraying water with various impurities and its subsequent evaporation is an important part of many technologies applied in the petrochemical industry, the TPU scientists said. However, according to them, such systems have a low degree of efficiency, which affects the cost of production.
For example, in thermal treatment chambers, where byproducts are separated, relatively large drops of an aqueous solution do not have enough time to evaporate during one operation cycle, which significantly reduces efficiency and increases time consumption.
As the scientists assume energy and resource consumption can be optimised by spraying liquid under special conditions in which it will be impossible for large droplets to form. The exact mathematical parameters of such a process are provided in the new research conducted by the TPU physicists.
"Crushing droplets of liquids, emulsions, solutions and suspensions can multiply the surface area of their evaporation. Using this effect along with changing the design and position of the sprayers, it is possible to significantly increase the efficiency of a large number of systems, from fire extinguishing to thermal energy using water vapour," Pavel Strizhak, Professor of TPU, Doctor of Physical and Mathematical Sciences, explained.
The data obtained, according to the authors of the research work, will help significantly increase the thermal power of combustion engines and boiler furnaces, as well as raise heat absorption in heat exchange systems by three to five fold. In the long run, this will also make it possible to optimise the dimensions of the combustion chambers, heat and mass transfer devices and the entire set of the other elements of heat and power systems.
Another area that will be significantly affected by the results of the research is the environmentally friendly power developing industry, the TPU scientists believe. According to them, today, the systems are being actively implemented which allow capturing hazardous products of combustion of hydrocarbons by using water and water vapour, preventing their release into the atmosphere.
"We have determined the transformation and decay time of droplets under the action of aerodynamic forces and for the first time have found the exact values of the critical criterion for the Weber and the Reynolds number, taking into account the capillarity and the Ohnesorge and Laplace numbers. This makes it possible to mathematically describe the entire process of crushing drops and make adjustments to the existing methods of spraying," Ivan Voytkov, one of the authors of the research, and a invited research engineer at TPU, said.
According to the scientists, the new experimental data are highly accurate, since the crushing of drops was first studied in the dynamics of a real air flow, for which video recording was used at a frequency of up to 100,000 frames per second. Water-containing mixtures of various compositions used in the industry were analysed as well.
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Палеонтологи Сергей Наугольных (Геологический институт РАН) и Мостафа Укассу (Университет Касабланки имени Хасана II) описали растение эпохи позднего девона, обнаруженное на территории Марокко в виде отпечатков в кварцитовом песчанике. Растение принадлежит отделу плауновидных и получило название Rehamnia michardis.
Une étude publiée par des chercheurs dans "Journal of African Earth Sciences" se penche sur une plante découverte au Maroc et qui serait le premier signalement de plante de l’ère "Dévonien tardif".
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Dénommé "Rehamnia michardis", cette plante présente certaines caractéristiques communes avec les lycopodiophytes du Dévonien et avec un certain nombre de plantes, qui sont comparables aux lycopodiophytes, mais dont la position systématique reste incertaine, expliquent les chercheurs. Les lycopodiophytes ou Lycophytes forment en effet un groupe de plantes vasculaires comprenant notamment les lycopodes et les isoëtes. Lors de deux visites de terrain effectuées en 2019 et 2020, les deux chercheurs Mostafa Oukassou et Serge V. Naugolnykh, ont pu collecter les mégafossiles végétaux de la rive nord de la rivière Kibane dans la colline Dalaâ à Foum El Mejez (Dans le massif de Rehamna).
Selon les deux chercheurs, les restes de cette plante sont conservés sous forme de compression et d'impression dans le grès quartzitique du sommet de la Formation de Dalaâ. "Le matériel est représenté par six spécimens pratiquement complets comprenant un holotype" (spécimen type ayant permis de définir et décrire une catégorie déterminée dans la classification des organismes vivants).
La morphologie générale des tiges, les cicatrices foliaires et les phylloïdes sont similaires aux mêmes structures organographiques de certains représentants des lycopodiopsidés, expliquent également le duo de chercheurs. D’après leur conclusion, l'étude ouvre de nombreuses nouvelles portes pour une compréhension plus approfondie de la diversité des plantes terrestres de l’ère du Dévonien.
Российско-американская команда ученых впервые описала процесс возникновения в космосе органических молекул полициклических ароматических углеводородов, сыгравших важнейшую роль в развитии самых ранних форм жизни на Земле.
Polycyclic Aromatic Hydrocarbons (PAHs) are complex organic molecules that may incorporate up to one-third of the organic carbon in our galaxy and are involved in fundamental molecular mass growth processes in our galaxy. PAHs are found in carbonaceous chondrites (a class of meteorite) and may initiate an abiotic synthesis (making compounds using non-living molecules) of material vital to the earliest forms of life on present-day Earth.
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The aromatic benzene molecule, discovered 175 years ago, is the basic molecular
building block of PAHs. A research team, led by University of Hawaiʻi at Mānoa Department of Chemistry Professor Ralf Kaiser, has exposed synthetic routes (non-natural formation by chemical compounds) to form the aromatic benzene molecule in combustion flames and in hydrocarbon-rich atmospheres of planets and their moons. The team’s findings were presented in the May 2021 issue of Science Advances.
Using high-tech instruments at the Advanced Light Source facility at the Lawrence Berkeley National Laboratory, a high-temperature chemical microreactor and advanced detection methods, the researchers combined the findings with calculations and simulations to discover the synthetic methods of forming the aromatic benzene molecule and its isomers through the ratio of two highly unstable organic radicals.
"This work provides compelling evidence on the formation of the very first ringed aromatic building block of PAHs - benzene - together with three structural isomers via previously poorly characterized radical-radical reactions," Kaiser said. "These results uncover fundamental mechanisms involved in molecular mass growth processes not only in hydrocarbon-rich solar systems environments, but also in combustion systems, thus gaining us a better understanding and rigid scientific foundation of the hydrocarbon chemistry of our universe."
The research team included Musahid Ahmed of Lawrence Berkeley National Laboratory and Alexander M. Mebel of Florida International University. This work was conducted in collaboration with Russian scientists from the Samara National Research University and the Lebedev Physical Institute. Funding for the study was provided by the Basic Energy Sciences program in the U.S. Department of Energy.
This work is an example of UH Mānoa’s goal of Excellence in Research: Advancing the Research and Creative Work Enterprise (PDF), one of four goals identified in the 2015-25 Strategic Plan (PDF), updated in December 2020.
Российские и финские археологи предположили, что лосиные зубы, найденные в Оленеостровском могильнике на Онежском озере, могли использоваться в качестве звукового сопровождения во время танцев. Зубы подвешивались или пришивались к одежде и при движении издавали дребезжащие звуки.
"Ornaments composed of elk teeth suspended from or sown on to clothing emit a loud rattling noise when moving," says auditory archaeologist and Academy of Finland Research Fellow Riitta Rainio from the University of Helsinki. "Wearing such rattlers while dancing makes it easier to immerse yourself in the soundscape, eventually letting the sound and rhythm take control of your movements. It is as if the dancer is led in the dance by someone."
Rainio is well versed in the topic, as she danced, for research purposes, for six consecutive hours, wearing elk tooth ornaments produced according to the Stone Age model. Rainio and artist Juha Valkeapää held a performance to find out what kind of wear marks are formed in the teeth when they bang against each other and move in all directions. The sound of a tooth rattler can be clear and bright or loud and pounding, depending on the number and quality of the teeth, as well as the intensity of movement.
Microanalysis demonstrates that tooth wear marks are the result of dancing
The teeth worn out by dancing were analysed for any microscopic marks before and after the dancing. These marks were then compared to the findings made in the Yuzhniy Oleniy Ostrov graves by Evgeny Girya, an archaeologist specialised in micro-marks at the Russian Academy of Sciences. Girya documented and analysed the wear marks in the elk teeth found in four graves chosen for the experiment. Comparing the chips, hollows, cuts and smoothened surfaces of the teeth, he observed a clear resemblance between teeth worn out by dancing and the Stone Age teeth. However, the marks in the Stone Age teeth were deeper and more extensive. According to Girya, the results show that the marks are the result of similar activity.
"As the Stone Age teeth were worn for years or even decades, it's no surprise that their marks are so distinctive," Girya says.
Associate Professor of Archaeology Kristiina Mannermaa from the University of Helsinki is excited by the research findings.
"Elk tooth rattlers are fascinating, since they transport modern people to a soundscape that is thousands of years old and to its emotional rhythms that guide the body. You can close your eyes, listen to the sound of the rattlers and drift on the soundwaves to a lakeside campfire in the world of Stone Age hunter-gatherers."
A total of 177 graves of women, men and children have been found in the Yuzhniy Oleniy Ostrov burial site, of which more than half contain several elk tooth ornaments, some of them composed of as many as over 300 individual teeth.
Copyright 2021 ScienceDaily.
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Биологи Института физико-химических и биологических проблем почвоведения РАН благополучно оживили нескольких бделлоидных коловраток, микроскопических многоклеточных животных, пролежавших 24 тысячи лет в вечной мерзлоте Якутии. Современные коловратки менее устойчивы к заморозке, что говорит о том, что древние представители этого семейства обладали эффективными механизмами защиты для выживания при низких температурах.
A microscopic animal has been revived after slumbering in the Arctic permafrost for 24,000 years.
Bdelloid rotifers typically live in watery environments and have an incredible ability to survive. Russian scientists found the creatures in a core of frozen soil extracted from the Siberian permafrost using a drilling rig.
"Our report is the hardest proof as of today that multicellular animals could withstand tens of thousands of years in cryptobiosis, the state of almost completely arrested metabolism," said Stas Malavin, a researcher at the Soil Cryology Laboratory at the Pushchino Scientific Center for Biological Research in Russia.
Earlier research by other groups had shown that the rotifers could survive up to 10 years when frozen. In a new study, the Russian researchers used radiocarbon dating to determine that the critters they recovered from the permafrost - ground that is frozen year-round, apart from a thin layer near the surface - were about 24,000 years old.
The study was published in the journal Current Biology on Monday.
It's not the first time ancient life has been resurrected from a permanently frozen habitat.
Stems of Antarctic moss were successfully regrown from a 1,000-year-old sample that had been covered by ice for about 400 years, and a living campion flower was regenerated from seed tissue, likely stored by an Arctic squirrel, that had been preserved in 32,000-year-old permafrost. Simple worms, called nematodes, were revived from the permafrost from two places in northeastern Siberia, in sediments that were more than 30,000 years old.
Long-dead but well-preserved mammals, including extinct cave bears and mammoths, have also been unearthed from the permafrost, which is thawing in some places as a result of the climate crisis.
Malavin said that it is highly unlikely bigger life forms could survive being frozen in this way.
"The takeaway is that a multicellular organism can be frozen and stored as such for thousands of years and then return back to life - a dream of many fiction writers," Malavin said in the statement.
"Of course, the more complex the organism, the trickier it is to preserve it alive frozen and, for mammals, it's not currently possible. Yet, moving from a single-celled organism to an organism with a gut and brain, though microscopic, is a big step forward."
Once the rotifer thawed, the creature was able to reproduce, the study said. The tiny invertebrates were also able to feed.
To understand how the creature survived in suspended animation in the frozen ground, the researchers froze and thawed modern day rotifers living in permafrost regions. They found that the creatures could withstand the formation of ice crystals while they were slowly frozen.
While not all the rotifers survived the freezing process, the study suggested that the creatures have some mechanism that can can shield their cells and organs from harm at very low temperatures.
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Chemie.de / 09-Jun-2021
Lead Halide Perovskites - a Horse of a Different Color
Novel spectroscopic technique developed.
Металлогалогенные перовскиты - новый класс полупроводников, которые можно использовать в оптоэлектронных технологиях. Однако фотофизические свойства этих материалов еще не изучены до конца, например, механизмы рекомбинации носителей заряда.
Исследователи из Дрезденского технического университета, Лундского университета и Института химической кинетики и горения им В.В.Воеводского СО РАН разработали двумерные карты, позволяющие не только получить представление о фотофизике образца, но и проверять возможные теории, объясняющие то или иное поведение носителей заряда.
In a joint experimental and theoretical effort between Lund University (Sweden), the Russian Academy of Science (Russia), and the Center for Advancing Electronics Dresden at Technische Universität Dresden (Germany), researchers developed a novel spectroscopic technique for the study of charge carrier dynamics in lead halide perovskites.
Metal halide perovskites have been under intense investigation over the last decade due to the remarkable rise in their performance in optoelectronic devices such as solar cells or light-emitting diodes. Despite tremendous progress in this field, many fundamental aspects of the photophysics of perovskite materials remain unknown, such as a detailed understanding of their defect physics and charge recombination mechanisms. These are typically studied by measuring the photoluminescence - i.e. the emission of light upon photoexcitation - of the material in both the steady-state and transient regimes. While such measurements are ubiquitous in literature, they do not capture the full range of the photophysical processes that occur in metal halide perovskites and thus represent only a partial picture of their charge carrier dynamics. Moreover, while several theories are commonly applied to interpret these results, their validity and limitations have not been explored, raising concerns regarding the insights they offer.
To tackle this challenging question, a trinational team of researchers from Lund University (Sweden), the Russian Academy of Science (Russia) and the Technical University of Dresden (Germany) have developed a new methodology for the study of lead halide perovskites. This methodology is based on the complete mapping of the photoluminescence quantum yield and decay dynamics in the two-dimensional (2D) space of both fluence and frequency of the excitation light pulse. Such 2D maps not only offer a complete representation of the sample’s photophysics, but also allow to examine the validity of theories, by applying a single set of theoretical equations and parameters to the entire data set. "Mapping a perovskite film using our new method is like taking its fingerprints - it provides us with a great deal of information about each individual sample." says Prof. Ivan Scheblykin, a Professor of Chemical Physics at Lund University. "Interestingly, each map resembles the shape of a horse’s neck and mane, leading us to fondly refer to them as ‘perovskite horses’, which are all unique in their own way."
"The wealth of information contained in each 2D map allows us to explore different possible theories that may explain the complex behavior of charge carriers in metal halide perovskites" adds Dr. Pavel Frantsuzov from the Siberian Branch of the Russian Academy of Science. Indeed, the researchers discovered that the two most commonly applied theories (the so called ‘ABC theory’ and the Shockley-Read-Hall theory) cannot explain the 2D maps across the entire range of excitation parameters. They propose a more advanced theory that includes additional nonlinear processes to explain the photophysics of metal halide perovskites.
The researchers show that their method has important implications for the development of more efficient perovskite solar cells. Prof. Dr. Yana Vaynzof, Chair for Emerging Electronic Technologies at the Institute for Applied Physics and Photonic Materials and the Center for Advancing Electronics Dresden (cfaed) explains: "By applying the new methodology to perovskite samples with modified interfaces, we were able to quantify their influence on the charge carrier dynamics in the perovskite layer by changing, for example, the density and efficacy of traps. This will allow us to develop interfacial modification procedures that will lead to optimal properties and more efficient photovoltaic devices."
Importantly, the new method is not limited to the study of metal halide perovskites and can be applied to any semiconducting material. "The versatility of our method and the ease with which we can apply it to new material systems is very exciting! We anticipate many new discoveries of fascinating photophysics in novel semiconductors", adds Prof. Scheblykin.
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Группа исследователей из Испании, Германии, Канады, Нидерландов и России проанализировала образцы костей и зубов неандертальцев возрастом 50 и 60 тысяч лет, обнаруженных в Чагырской пещере (Алтайский край) с целью получить представление о рационе питания древних людей. Выяснилось, что меню было достаточно разнообразное - много животного белка, различные растения. Диета оказалась схожей с диетой европейских неандертальцев, из чего можно сделать вывод, что мигрировавшие на Алтай группы сохраняли свои пищевые привычки.
Neanderthals, extinct cousins of modern humans, occupied Western Eurasia before disappearing and although it was once thought that they travelled as far east as Uzbekistan, in recent years an international research team with the participation of the University of Valencia discovered that they reached two thousand kilometers further East, to the Altai Mountains of Siberia.
An international research team led by Domingo Carlos Salazar, CIDEGENT researcher of excellence at the University of Valencia, published today in the Journal of Human Evolution the first attempt to document the diet of a Neanderthal through a unique combination of stable isotope analysis and identification of plant micro-remnants in an individual.
The analysis of Neanderthal bones and dental stones from Siberia sheds light on their dietary ecology, at the eastern limit of their expansion. It is a very dynamic region where Neanderthals also interacted with their enigmatic Asian cousins, the Denisovans.
The work refers both to western Siberia, where there are studies that explain that modern humans responded with high mobility, and to the eastern part, where there is a lack of work that analyses the behaviour and subsistence of Neanderthals, who inhabited this Siberian forest steppe, which is drier and colder than the western one.
Studying the diets of eastern Neanderthals allows us to understand their behaviours, mobility and potential adaptability.
A team of researchers from Spain, Germany, Canada, The Netherlands and Russia, led by physician and historian Domingo Carlos Salazar García from the University of Valencia, took bone samples and dental calculus from Neanderthal remains dated to 60 and 50 ka BP from the site of Chagyrskaya in the Altai Mountains in Southern Siberia, located just 100 km from the Denisova Cave.
Analyses of the stable carbon and nitrogen isotopes from one mandible (Chagyrskaya 6) revealed that this individual had a relatively high trophic level compared to the local food web, indicating that it consumed a large amount of animal protein from hunting large and medium-sized game.
Using optical microscopy, the researchers identified a diverse assemblage of microscopic particles from plants preserved in the dental calculus from the same individuals as well as from others from the site. These plant microremains indicate that the inhabitants of Chagyrskaya also consumed a number of different plants.
These results can help us answer a long-standing enigma about the Altai Neanderthals: the region was tempting enough that Neanderthals colonised the area at least twice, but genetic data indicates they were barely hanging on, living only in small groups that were constantly at risk of extinction.
The dietary data now indicates that this unusual habitation pattern was probably not due to a lack of adapting their diet to the local environment. Instead, other factors such as the climate or interaction with other hominins should be investigated in future studies.
"Neanderthals were capable of having a diverse menu even in adverse climatic environments", says Domingo C. Salazar García, "it was really surprising that these eastern Neanderthals had broadly similar subsistence patterns to those from Western Eurasia, showing the high adaptability of our cousins, and therefore suggesting that their dietary ecology was probably not a disadvantage when competing with anatomically modern humans".
"A better grasp of Neanderthal dietary ecology is not only the key to better understand why they disappeared, but also to how they interacted with other populations who they coexisted with, like the Denisovans" says Bence Viola, assistant professor at the Department of Anthropology at the University of Toronto.
"To really understand the diets of our ancestors and cousins, we need more studies like this one that make use of multiple different methods on the same individuals. We can finally understand both the plant and animal foods that they ate", offers Amanda G. Henry, assistant professor at the Faculty of Archaeology of Leiden University.
"The steppe lowlands of the Altai Mountains were suitable for the habitation of the Neanderthals 60,000 years ago. Despite the sparse vegetation and its seasonal nature, the absence of tundra elements and relatively mild climate allowed eastern Neanderthals to keep the same food strategies as their western relatives", says Natalia Rudaya, head of PaleoData Lab of the Institute of Archaeology and Ethnography Siberian Branch Russian Academy of Science.
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Российские климатологи не одобрили рекомендацию Министерства иностранных дел о финансировании исследований, которые позволили бы продвигать «альтернативные» точки зрения на изменение климата, которые «не обязательно означают отказ от ископаемого топлива и ограничение промышленного роста».
Russia is a signatory to the Paris climate agreement, and dozens of its scientists have contributed to the consensus reports of the Intergovernmental Panel on Climate Change (IPCC) that detail the causes and consequences of global warming. This month, the lower chamber of Russia’s parliament passed the country’s first climate bill, setting a course for carbon neutrality through emissions reductions and limits on deforestation. Just last week, speaking at the St. Petersburg International Economic Forum, President Vladimir Putin said Russia is concerned about climate change, and any claims that it is not are "nonsense, a myth, and sometimes outright distortion."
But not everyone in Putin’s government seems to have gotten the message. Last month, in a document reviewed by ScienceInsider, the country’s Ministry of Foreign Affairs recommended funding studies that would allow Russia to promote "alternative" viewpoints on climate change that "would not necessarily imply abandoning fossil fuels and limiting industrial growth."
The document, signed on 21 May by the head of the ministry’s department of international organizations, also says the United Nations and IPCC "have been aggressively forcing the consensus on the causes of climate change. … For a long time, a ‘scientific basis for climate change’ has been forming that is not always favorable to Russia." And it asserts that "Isolated alternative research is not developed further nor discussed by the international scientific community (it is basically blocked or silenced)."
Climate scientists are upset by the ministry’s recommendations, which were sent to the Ministry of Economic Development, which oversees domestic climate policy, for "potential consideration." It is "very unfortunate that such a document was published in a country which looks back to an enormous scientific tradition," says Thomas Stocker, a climate scientist at the University of Bern and former co-chair of an IPCC working group. "It’s almost like betraying your rich legacy of research."
Anna Romanovskaya, head of the Yuri Izrael Institute of Global Climate and Ecology, says the recommendations reveal a profound lack of understanding about how climate research works. They also represent an attack on the integrity of climate scientists, she says. "This slander should stop, and the work of researchers, including climate scientists, should be protected from political pressure."
The Ministry of Foreign Affairs’s department of international organizations, which is responsible for Russia’s participation with the United Nations and its climate talks, did not respond to a request for comment.
It’s not the first time that contrarian views on climate science have reached high levels in Russia. In 2019, several Russian IPCC authors, including Romanovskaya, wrote to the president of the Russian Academy of Sciences, complaining that the academy had recommended against ratifying the Paris agreement over "a lack of consensus" on the causes of global warming, and that it had done so without consulting any of the scientists. Russia did join the agreement in the end, and the academy has since revamped its internal council on climate.
Alexander Chernokulsky, an atmospheric physicist and academic secretary of the new academy climate council, says the ministry recommendations remind him of "tobacco companies and their attempts to disrupt science and sow doubt to stall regulation." However, he notes that other parts of the document call for mainstream climate policies. Those internal contradictions, he says, may be due to "confusion and cluelessness rather than malice."
After an introduction on climate science, the document calls for policies such as better forestry management, energy efficiency, and even a potential carbon tax on imports. Marianna Poberezhskaya, who studies Russian climate politics at Nottingham Trent University, calls the foreign affairs document a "mixed bag," and thinks it reasonably reflects popular attitudes toward climate change in Russia. "Climate skepticism keeps reappearing but climate discussion in Russia is not monolithic," she says.
But Poberezhskaya is disappointed that a high-level ministry would promote such a mixed message. "It is a shame," she says, "that it still mentions such conspiracy-fueled denialist rhetoric, which is absolutely unnecessary and even damaging to progress in Russian climate science, policy, and public attitudes."
© 2021 American Association for the Advancement of Science. All rights Reserved.
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PR Newswire / Jun 10, 2021
Researchers Discover Critical Role of Hydrogen Sulfide in Ability of Bacteria to Survive Antibiotics
Prototype Drugs Found to Strengthen Antibiotics by Blocking Bacterial H2S Biogenesis.
Российские и американские биохимики нашли способ преодолеть возникающую у ряда бактерий резистентность к антибиотикам, подавив фермент цистатионин-гамма-лиазу. Фермент производит сероводород, защищающий бактерии от окислительного стресса.
The signaling molecule hydrogen sulfide (H2S) plays a critical role in antibiotic tolerance, the innate ability of bacteria to survive normally lethal levels of antibiotics, a new study finds.
Published online in the journal Science on June 11, the study revolves around tolerance, wherein bacteria in general have evolved to use common defense systems to resist antibiotics. Tolerance differs from antibiotic resistance, where one species happens to acquire a genetic change that helps them resist treatment.
In one defense mechanism, tolerant bacteria, also called "persisters," stop multiplying (proliferating), reducing their energy use (metabolism) to survive antibiotic treatment, but resuming growth when the treatment ends. Persisters are particularly abundant in biofilms, bacterial colonies that live in tough polymeric matrices which further prevent their eradication.
"The combined trends toward resistant infections and fewer new antimicrobials are projected to kill 10 million people annually by the year 2050," says corresponding study author Evgeny Nudler, PhD, the Julie Wilson Anderson Professor of Biochemistry at NYU Langone Health, and an investigator with the Howard Hughes Medical Institute. "New approaches are urgently needed to prevent this, and our study suggests that suppressing bacterial H2S would make different antibiotics more potent."
In their prior work, the NYU Langone research team showed that H2S production is deployed against antibiotics by a wide variety of bacterial species, including two increasingly antibiotic-resistant pathogens prevalent in hospital-borne infections: Staphylococcus aureus and Pseudomonas aeruginosa. S. aureus is gram-positive, while Pseudomonas aeruginosa is gram-negative, with the differing organizations of their outer layers demonstrating that H2S production protects pathogens across the bacterial kingdom.
Remarkably, the research team found that both species rely on the same enzyme, cystathionine γ-lyase (CSE), for the bulk of H2S production. Blocking its action would represent then a way to remove an important defense against antibiotics, but available CSE inhibitors have a low potency against bacterial CSE and a high probability of causing side effects in human tissue, says Nudler.
To find better inhibitors, the research team obtained an x-ray structure of S. aureus CSE and used it to "virtually screen" millions of drug-like compounds looking for those with the right shape and properties to block the enzyme's action without side effects. The team selected lead compounds, NL1, NL2, and NL3, which inhibited the bacterial CSE, blocked H2S production by both S. aureus and P. aeruginosa, and strengthened the effect of bactericidal antibiotics from different classes. Furthermore, NL1 increased the potency of antibiotic effect in mouse models of S. aureus and P. aeruginosa infection.
Unexpectedly, further testing revealed that the NL compounds markedly diminished persisters, and suppressed biofilm formation in both pathogens.
How exactly H2S contributes to tolerance remains to be established, but there are some hints.
"Bacteria appear to use controlled, self-poisoning with H2S to slow down their metabolism, preventing the antibiotics from using the bacteria's energy production system to kill them," says Nudler. "Interfering with the H2S-based defenses represents a largely unexplored alternative to the traditional antibiotic discovery. Our results suggest that a new kind of small molecule potentiator can strengthen the effect of major classes of clinically important antibiotics."
The authors note several opportunities for designing conceptually novel antimicrobial therapeutics by combining H2S-blocking potentiators with antibiotics. Such combinations may have better efficacy against bacterial biofilms. Other potential applications include overcoming intermediate-level antibiotic resistance; reducing antibiotic dose and related toxicity while maintaining efficacy; and enhancing the bacteria-killing (bactericidal) effect at the same antibiotic dose.
Along with Nudler, the study was led by first authors Konstantin Shatalin and Ashok Nuthanakanti in the Department of Biochemistry and Molecular Pharmacology at NYU Langone Health. Also authors were Abhishek Kaushik, Alla Peselis, Ilya Shamovsky, Bibhusita Pani, Mirna Lechpammer, Nikita Vasiliev, Elena Shatalina, and Alexander Serganov at NYU Langone, as well as Dmitry Shishov and Peter Fedichev of Gero LLC, Moscow, Russia; Dmitri Rebatchouk of Ellyris LLC in Union, NJ; and Alexander Mironov of the Engelhardt Institute of Molecular Biology, Russian Academy of Sciences in Moscow. The study was funded by the Blavatnik Family Foundation, the United States Department of Defense, and the Howard Hughes Medical Institute.
Copyright © 2021 Cision US Inc.
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С помощью желудочной бактерии Helicobacter pylori ученые из шести стран, включая Россию, проследили миграцию людей из Сибири в Америку 12 000 лет назад, а также пришли к выводу, что во время последнего ледникового максимума (около 20 000 лет назад) часть древнего населения Сибири не мигрировала на юг, а сумела пережить самое холодное время на севере.
Gut bugs and bacterias have provided new insights about the peopling of Siberia and human migration into the Americas, which may appear to be an unexpected source of information.
Helicobacter pylori is a bacteria that can cause stomach ulcers and dwells in people's digestive tracts. For at least the past 100,000 years, it has evolved alongside (and within) humans, accompanying people out of Africa, on cross-continental migrations, and beyond.
By reconstructing H. pylori's evolutionary path as it traveled about in the stomachs of early humans, an international team had provided more detail to the fragmentary fossil record of how and when people travelled from Siberia to the Americas.
"This study now uses the powerful approach of ABC statistics to reconstruct and date the migrations of Siberian H. pylori (and their human hosts) across Siberia and to the Americas," researchers said per Phys.org.
But, more importantly, the study provides insight into the complicated history of Siberian people, some of whom seemed to have survived the worst of the last ice age.
"The peopling of Siberia and the Americas is intriguing for archaeologists, linguists, and human geneticists, but despite significant recent developments, many details remain controversial," the research team, led by zoologist Yoshan Moodley, wrote in a report from Proceedings of the National Academy of Sciences (PNas).
Everything from the time of human migration from Eurasia to the Americas to the routes taken by the first migrants has been challenged by fresh evidence in recent years.
Did humans cross land bridges or travel over kelp motorways along the coast? Did they arrive in the Americas as the trans-Siberian glaciers thawed, or were they there much earlier?
However, there are still some unanswered problems, primarily because ancient human remains are scarce and difficult to come by. Genetic studies that track slow steps in human evolution can only tell us so much.
Recent genomic analyses of ancient human DNA have provided more evidence that Siberia served as a crossroads for human migrations into northern America and western Eurasia.
Bacteria in Human Gut Could Suggest More Historical Insights
As it turns out, the DNA sequences of bacteria living inside humans for a long period include more historical insights.
To better comprehend previous human migration, the researchers collected over 550 different strains of H. pylori from 16 ethnic and traditional language groups living in modern-day Siberia and Mongolia.
H. pylori infect more than half of the world's population, but little is known about the gut bug's presence or diversity in these distant areas.
The team wrote that the region's multiplicity of language groups suggests a complicated history of movement and isolation. They went on to say that the patterns of human variety between different ethnic groupings are equally understudied. H. pylori, as a bacterium, reproduce quickly in the human gut, mutating ever so little. As a result, comparisons of divergent strains can reveal how various groups of people worldwide are linked, making it a helpful marker of human migrations.
Florida Times News said Moodley and his colleagues recreated the evolutionary histories of H. pylori strains collected in Siberia and the Americas. They then calculated how individuals and H. pylori strains would have crossed the continental divide.
The researchers found that because humans across "the entire extent" of Siberia shared H. pylori strains with humans in North America, there was likely a single migration event as recently as 12,000 years ago.
However, growing archaeological data, ancient bones, and genetic studies all point to a considerably earlier human migration into the Americas, perhaps between 13,000 and 23,000 years ago.
How Ice Age Contributed To History
Another topic of contention is whether people who initially arrived in Siberia around 45,000 years ago stayed during the coldest portion of the previous ice age (about 20,000 years ago) or migrated south.
Ice sheets covered a quarter of the Earth's surface area and a third of Alaska during the last glacial maximum. Sea levels have also risen, exposing land bridges such as the one that originally connected Russia and Alaska over the Bering Sea.
The researchers concluded that some individuals must have survived in northern Siberia during the last ice age because researchers identified the same ancient H. pylori strains across the country.
Across the region, however, the team discovered a few more recently admixed H. pylori genotypes. This shows that once the weather warmed throughout the Holocene, around 12,000 years ago, isolated people in central and southern Siberia re-joined the hardy tribes in the north.
The study entitled "Helicobacter pylori's historical journey through Siberia and the Americas" is published this week (14 June) in the journal PNAS.
© 2021 ScienceTimes.com All rights reserved.
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HPCwire / June 14, 2021
Lomonosov Moscow State University Announces Supercomputing and High-Technology Branch in Sarov
Московский государственный университет объявил о создании в Сарове крупного филиала в составе национального центра физики и математики. Филиал должен будет стать научно-образовательным центром мирового уровня.
Lomonosov Moscow State University announces the establishment of a major new branch as a key part of the Russian National Physics and Mathematics Center. Its creation is an important initiative and is part of strategic planning by the office of President V.V. Putin of the Russian Federation. This world class institute is being colocated in Sarov, Russia, south of the Nizhniy Novgorod region.
The goal and charter of the Lomonosov MSU Branch ("MSU-Sarov") is to train high-quality specialists in the theoretical and practical foundations of physics and mathematics, computer sciences, and supercomputer technologies. MSU-Sarov branch designed to employ the highest standards of scientific and educational practices.
Commenting on the opening of this branch in Sarov, the Rector of Moscow State University, Academician Victor Sadovnichy, stated: that "The new branch being established will be oriented to educate advanced master’s degree students in fundamental areas of computational mathematics and physics. It is well-known that specialists in the fundamentals create scientific breakthroughs faster than anybody else, and only fundamental discoveries allow making correct technological decisions."
The MSU-Sarov Branch will be a part of a world-class scientific and educational center equipped with the most advanced and diverse experimental and computational facilities. These are being implemented by MSU, the State Corporation "Rosatom," the Russian Academy of Sciences, and the Research Center "Kurchatov Institute" under the auspices of the Government of the Russian Federation in close cooperation with Russian and international scientific and educational organizations.
"The new Physics and Mathematics Center should attract scientists and young specialists from universities and educational centers of our entire country. Introduction of innovative educational programs will allow the MSU Branch in Sarov to become one of the greatest centers of science and education in Russia. Its graduates will enter the intellectual elite," stated Alexey Likhachev, Director General of the State Corporation "Rosatom."
Students of the MSU-Sarov Branch will have the opportunity to perform research at unique physical facilities, use the computational resources of the most productive computers in Russia deployed by MSU and Rosatom, learn from the finest professors, and undertake science guided by leading scientists. This modern campus is being organized, architected and equipped with leading-edge state-of-the-art facilities. It is designed to enable advanced studies, research, cooperative engagement and quality of life. This is planned to be a truly advanced technology based academic city dedicated to science and education.
Educational programs at MSU-Sarov will begin in the fall of this year. Master programs have been developed and prepared incorporating the high educational standards of Moscow State University. Fifty masters students will begin their studies in five educational programs developed specifically for the Branch. The fundamental areas of computational mathematics, physics and supercomputing technologies include:
• Advanced Computing Technologies. Numerical Modeling Methodology.
• Supercomputing Technologies for Large-Scale Mathematical Modeling and Data Processing.
• Extreme Electromagnetic Fields, Relativistic Plasma & Attoscience.
• Laser Nonlinear Optics & Photonics.
• Theoretical Physics.
In following years, the number of subject areas and educational programs will expand to address a wider body of fields. It is planned to start enrolment for the PhD studies in 2022. Specialized integrated 6-years master degree programs are to be developed through future student enrollment and innovative syllabus.
Prof. Vladimir Voevodin, recognized as a leader in the international supercomputer community, the Director of the MSU Research Computing Center, and Corresponding Member of the Russian Academy of Sciences, has been appointed as the Head of the Direction for establishment and functioning of the MSU Branch in Sarov.
© 2021 HPCwire. All Rights Reserved. A Tabor Communications Publication.
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Ars Technica / 6/16/2021
Someone stabbed a cave bear in the head with a spear 35,000 years ago
It's a rare piece of evidence of people killing cave bears during the Pleistocene.
Изучив череп малого пещерного медведя возрастом около 35 тысяч лет, найденный в башкирской пещере Иманай в 2015 году, палеонтологи Уральского федерального университета и УрО РАН пришли к выводу, что отверстие в черепе нанесено оружием и именно оно стало причиной смерти. Это первое и пока единственное в мире свидетельство того, что доисторические люди охотились на малых пещерных медведей.
During the last Ice Age, more than 100 cave bears died in Imanay Cave, a 100-meter-long corridor of stone in Russia’s southern Ural Mountains. The dead bears, along with a cave lion and a few other Pleistocene mammals, left behind nearly 10,000 bones, which have mostly worn down to small fragments over the millennia. Most of them were so-called small cave bears, Ursus spelaeus eremus, notable for being smaller than the so-called large cave bear, Ursus spelaeus - and for their apparent habit of dying en masse while hibernating through the harsh Pleistocene winters, leaving behind huge assemblages of bones for modern paleontologists to find.
Most of the cave bear bones found in Eurasia, including the ones at Imanay Cave, show no signs of violence, butchering, or gnawing. They seem to have died quietly, perhaps of cold, starvation, or illness. But while cleaning one cave bear skull from Imanay, Dmitry Gimranov of the Ural Branch of the Russian Academy of Sciences and his colleagues noticed a rather suspicious hole in the parietal bone, near the back of the skull.
The lower edge of the hole is a gentle curve with a flattened base, while the upper edge is more uneven and widens sharply in the middle. Its shape is strikingly similar to the cross-section of stone projectile points unearthed in the same layer of cave sediment as most of the bear bones. Those points tend to have a flat ventral (or lower) side and a more curved dorsal (or upper) side with a sharp rib of stone sticking up along the center. And they're about the same size as the hole in the bear skull.
"Matching the section and size of the points and the hole on the bear's skull allows [us] to assume that the beast was hit with just such a weapon," wrote Gimranov and his colleagues. "Most likely, the spike was used as a spearhead." (They published their work in the Russian journal Vestnik Archeologii, Anthropologii, I Ethnographii, but you can read an English abstract here; copy-and-pasting excerpts of the Russian paper into Google Translate also yields very readable results.)
It was clearly a powerful blow. The spearhead pierced the bear's skull and left its mark on the surrounding bone. "The walls of the hole are chipped, visible on the surface numerous flat facets directed from the hole along the surface of the bone, as well as through cracks going in the same direction," wrote Gimranov and his colleagues. "The described features of the hole indicate its obvious artificial origin in a very strong impact with a hard object."
If Gimranov and his colleagues are correct, that could mean that a person killed at least one of the 110 dead small cave bears in Imanay Cave.
Loaded for bear
That’s not as surprising as it sounds - there’s some evidence of people killing and even butchering other bear species, like large cave bears and brown bears, during the Pleistocene. For instance, archaeologists have found the bones of about two dozen large cave bears at sites scattered across Eurasia; many have the telltale cut-and-scrape marks of defleshing, and one even has the tip of a stone projectile still lodged in a vertebra.
Of course, that’s a few dozen out of literally millions of bear bones unearthed at Pleistocene sites across Europe and western Asia. We probably shouldn’t picture Pleistocene hunters going after bears as prey on a regular basis. But the need for shelter from the elements probably brought people and bears into contact alarmingly often.
"Caves attracted not only animals, but also humans," wrote Gimranov and his colleagues. "Finding the bones of cave bears and artifacts together is quite common." At Imanay Cave, for instance, archaeologists found stone tools from the Mousterian culture, as well as bits of charcoal and ocher, in the same sediment layers as the bear bones. That’s fairly common at other sites in Eurasia, too. And in one French cave, dating to around the same age as Imanay Cave, people buried their dead in abandoned bear nests. In other caves, people and bears almost seemed to take turns, with human footprints overlapping bear tracks and vice versa.
So although you'd have to be crazy or desperate to hunt cave bears for dinner on a regular basis, it’s reasonable to speculate that people trying to survive the Ice Age may sometimes have survived surprise encounters with disgruntled bears or scavenged the meat from freshly dead carcasses. If Gimranov and his colleagues are right about the Imanay Cave bear skull, at least one Pleistocene hunter had one heck of a bear story to tell.
Paws for reflection
Unfortunately, we can't learn the really exciting details of that story, but here’s what we can piece together from the available evidence: radiocarbon dating material from the bone reveals that the encounter happened roughly 35,000 years ago. The broken bone didn’t have time to start healing, which suggests that the injury occurred right around the time of death. And calcite deposits had time to form in the cracks and facets around the hole, which means the skull spent a very long time buried in the cave after the damage was done; in other words, the damage happened before burial, not during.
Based on the number of growth layers in the root of one molar, the bear was probably between nine and 10 years old when it died. Bear teeth grow new layers twice a year, during the summer and during the winter. By counting those layers, Gimranov and his colleagues concluded that the bear died during the winter, when it would most likely have been curled up in the cave hibernating. That scenario seems to match the location of the stab wound: at the back of the bear's skull, near the base, as if the person who did the stabbing was standing behind and above the bear.
It’s not too hard to picture a Pleistocene person wandering into a cave, maybe looking for shelter, and stumbling across a dozing bear, then stabbing it in a moment of panic. That’s pure speculation, of course. Gimranov and his colleagues also suggest the damage may have been done after the bear died as part of a ritual, but there's no other evidence of ritual activity in the cave, and no other bear skulls seem to have been stabbed.
© 2021 Condé Nast. All rights reserved.
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Кремний является основным материалом для создания микросхем, но он плохо взаимодействует со светом, что мешает его использованию в качестве источника излучения. Российские исследователи нашли способ усилить фотолюминесценцию в кремнии с помощью квантовых точек германия и специально разработанного фотонного кристалла.
Researchers in Russia have increased photoluminescence (PL) in silicon using germanium quantum dots and a specially designed silicon photonic crystal. Developed by scientists from Skolkovo Institute of Science and Technology (Skoltech), Institute for Physics of Microstructures of the Russian Academy of Sciences, Lobachevsky State University of Nizhny Novgorod, ITMO University, Lomonosov Moscow State University, and A.M. Prokhorov General Physics Institute of the Russian Academy of Sciences, the method and demonstration could lead to optoelectronic components that are compatible with silicon technology.
The technique is based on bound states of continuum. According to the researchers, it may pave the way to photonic integrated circuits (PICs).
"Silicon itself weakly interacts with light; it is a poor emitter and a poor absorber of photons. Therefore, taming silicon to interact with light effectively is an essential task," Sergey Dyakov, senior researcher at Skoltech, said.
To increase PL in silicon, the researchers introduced bound states in the continuum into the emission process - a technique derived from quantum mechanics. They used a resonator based on bound states in the continuum that confined light effectively because the symmetry of the electromagnetic field inside the resonator did not correspond to the symmetry of the electromagnetic waves of the surrounding space.
For the PL source, the researchers chose germanium nanoislands, which can be embedded into specific locations on a silicon chip. Tests showed that the PL of germanium nanoislands in silicon photonic crystal slabs with hexagonal lattice was significantly enhanced, and that the enhancement was due to the inclusion of bound states in the continuum in the emission process.
The researchers realized PL resonance peaks with a quality factor as high as 2200 and with a peak PL enhancement factor of more than two orders of magnitude. The corresponding integrated PL demonstrated PL enhancement of more than one order of magnitude.
"The use of bound states in the continuum increased luminescence intensity by more than a hundred times," Dyakov said. The team did a theoretical study on the effect of bound states in the continuum using the Fourier modal method in the scattering matrix form.
Dakov believes that the work of the Russian team could open the way for CMOS-compatible photonic integrated circuits, improving CMOS performance by lessening the heat release caused by the density of elements in CMOS circuits. The ability to switch from metallic to optical connections between the elements could reduce heat generation because unlike electrons, photons can travel for huge distances with minimal heat losses.
"The transition to CMOS-compatible photonic integrated circuits will also make it possible to significantly increase the information transfer rate within a chip and between individual chips in modern computers, making them faster," Dyakov said.
Silicon today remains the leading material for the development and manufacture of chips, and most digital microcircuits are created using CMOS technology. Heat release due to high density of elements in CMOS circuits has contributed directly to the inability to further increase device performance.
One potential workaround is reducing heat generation by switching from metallic connections between elements in microcircuits to optical ones. Unlike electrons in conductors, photons can travel great distances in waveguides with minimal heat losses.
"The results open up new possibilities for creating efficient radiation sources based on silicon, built into the circuits of modern microelectronics with optical signal processing," said professor Nikolay Gippius, head of the nanophotonics theory group at the Center of Photonics and Quantum Materials at Skoltech. "There are currently lots of groups working on creating light-emitting diodes based on such structures and the principles of their coupling with other elements on an optoelectronic chip."
The research was published in Laser & Photonics Reviews.
© 2021 Photonics Media.
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Исследователи Сколтеха совместно с британскими коллегами создали устойчивый гигантский квантовый вихрь во взаимодействующих поляритонных конденсатах, решив одну из проблем квантовой гидродинамики. Это может открыть новые возможности для аналогового моделирования гравитации или динамики черных дыр на микроскопическом уровне.
This may open new possibilities for analog simulation of gravity or black hole dynamics at the microscopic level.
Skolkovo Institute of Science and Technology (Skoltech) in Russia, communicates that a team of its scientists, in collaboration with researchers from three British universities, has created a stable giant vortex in the interaction of polariton condensate, thus solving a well-known problem in quantum hydrodynamics.
In hydrodynamics, a vortex is a region of space where a the fluid revolves around a point or a similar streak of eddies that can be seen in the drain. Vortex also exists in the quantum world: the flow of quantum liquid can create a region where the particles are constantly rotating around a certain point.
In this research, its authors studied vortex generated by polariton - unusual hybrid quantum particles that are half light (photon) and half matter (electrons), and under certain conditions form a quantum fluid. The researchers were looking for a way to create vortices with large angular momentum in polariton fluids, that is, to make them spin rapidly. These vortices, also known as giant swirls, is very difficult to form because it tends to penetrate many smaller vortices with low angular moments.
The creation of stable giant vortices demonstrates this unbalanced quantum systems, in particular polariton capacitors, are not always subject to the severe limitations of their thermodynamic counterpart, such as cold corn capacitors from Bose Einstein, scientists note.
Achieving quantum fluid vortex control could open up new possibilities about analog simulation of gravity or the dynamics of black holes at the microscopic level. In addition, the polariton capacitor constantly emits photons that carry all the information about the properties of the vortex, which can be important for the optical storage systems data transmission and processing.
This result clearly shows that polaritons can be sandbox. "Very good at studying complex natural phenomena. We were able to show a system that has a lot in common with radiant black hole. "Or, if you prefer, a white hole," said Pavlos Lagodakis, a professor at Skoltech.
Copyright © All rights reserved.
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Harvard Gazette / June 22, 2021
New wrinkle in tale of wolf-to-dog evolution
Research from Russian experiment suggests a surprising evolutionary brain change.
Уникальный эксперимент по одомашниванию лис, начатый академиком Дмитрием Беляевым в 1958 г., по-прежнему вызывает пристальный интерес ученых. Американские и российские (Институт цитологии и генетики СО РАН) исследователи установили, что у животных, выведенных в рамках селекции по поведению (как «ручная», так и «агрессивная» группы) объем мозга и серого вещества больше, чем у обычных лис из контрольной группы. Это говорит о том, что формирование противоположных поведенческих реакций может привести к сходным изменениям мозга, причем очень быстро - менее чем за сто поколений.
When Erin Hecht was earning her Ph.D. in neuroscience more than a decade ago, she watched a nature special on the Russian farm-fox experiment, one of the best-known studies on animal domestication.
The focus of that ongoing research, which began in 1958, is to try to understand the process by which wild wolves became domesticated dogs. Scientists have been selectively breeding two strains of silver fox - an animal closely related to dogs - to exhibit certain behaviors. One is bred to be tame and display dog-like behaviors with people, such as licking and tail-wagging, and the other to react with defensive aggression when faced with human contact. A third strain acts as the control and isn’t bred for any specific behaviors.
Hecht, who’s now an assistant professor in the Harvard Department of Human Evolutionary Biology, was fascinated by the experiment, which has helped scientists closely analyze the effects of domestication on genetics and behavior. But she also thought something fundamental was missing. What she didn’t know was that filling that knowledge gap could potentially force reconsideration of what was known about the connection between evolutionary changes in behavior and those in the brain.
"In that TV show, there was nothing about the brain," Hecht said. "I thought it was kind of crazy that there’s this perfect opportunity to be studying how changes in brain anatomy are related to changes in the genome and changes in behavior, but nobody was really doing it yet."
Hecht acted fast and sent an email to Lyudmila N. Trut, the scientist running the Siberian institute where the Russian foxes were being studied. Fast forward to today and that email was foundational for a surprising new study emerging from the fox-farm animals. Published Monday in the Journal of Neuroscience, the paper raises questions about some of the leading theories on domesticated animals’ brains.
By analyzing MRI scans of the foxes, Hecht and her colleagues showed that both the foxes bred to be tame and those bred to be aggressive have larger brains and more gray matter than those of the control group. These findings run contrary to other studies on chickens, sheep, cats, dogs, horses, and other animals that have shown domesticated species have smaller brains, with less gray matter, than their wild forebears.
Hecht and her team of researchers from Harvard, University of Illinois at Urbana-Champaign, Emory University, Cornell University, and the Russian Institute of Cytology and Genetics say they can’t be sure why this happens without further study. Their leading hypothesis centers on how the tame and aggressive strains have both been bred for specific behaviors at an accelerated time frame compared with many other domesticated animals. Dogs, for example, have been domesticated for at least 15,000 years.
"Both the tame and aggressive strains have been subject to intense, sustained selection on behavior, while the conventional strain undergoes no such intentional selection," they wrote. "Thus, it is possible that fast evolution of behavior, at least initially, may generally proceed via increases in gray matter."
As they analyzed the MRI scans, scientists noticed another surprise: similarities in the ways that the brains of the aggressive and tame foxes were changing. Both, for instance, showed enlargement in many of the same regions, including the prefrontal cortex, the amygdala, the hippocampus, and the cerebellum.
Results suggest that selection for opposite behavioral responses can produce similar changes in brain anatomy. It also appears that significant shifts in the structure and organization of the nervous system can evolve very quickly. In fact, it can happen within the span of less than 100 generations.
Taken together, the researchers say the study’s findings suggest existing ideas of brain changes in domestication may need revising, and that the brains of other animals, including humans, may have gone through similarly abrupt morphological shifts during times when rapid changes in environment or climate made certain behaviors more evolutionarily advantageous.
Next steps in the research include observing the foxes’ brains scans at a cellular level.
The researchers believe there’s a lot left to be learned from the Russian farm foxes and domesticated species, in general. That’s because when a species splits from its wild counterpart, its brain, body, and behavior undergo rapid changes. Studying the foxes and other domesticated animals provides a window into these complex evolutionary processes.
"It’s a more simple and straightforward way to see how evolution changes brains than we can achieve with just studying naturally occurring evolved brain changes," Hecht said.
© 2021 The President and Fellows of Harvard College.
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Science / Jun. 23, 2021
Ancient Siberian cave hosted Neanderthals, Denisovans, and modern humans - possibly at the same time
Проанализировав за два года 728 образцов осадочных пород из Денисовой пещеры, исследователи из Германии, Австралии, Израиля и России (Институт археологии и этнографии СО РАН), обнаружили ДНК человека современного типа в 175 из них. Это доказывает, что они также населяли пещеру, причем случилось это около 45 тысяч лет назад, после денисовцев и неандертальцев.
A decade ago, anthropologists shocked the world when they discovered a fossil pinkie bone from a then-unknown group of extinct humans in Siberia’s Denisova Cave. The group was named "Denisovans" in its honor. Now, an extensive analysis of DNA in the cave’s soils reveals it also hosted modern humans - who arrived early enough that they may have once lived there alongside Denisovans and Neanderthals.
The new study "gives [researchers] unprecedented insight into the past," says Mikkel Winther Pedersen, a molecular paleoecologist at the University of Copenhagen who was not involved with the work. "It literally shows what [before] they have only been able hypothesize."
Humans - including Neanderthals and Denisovans - are known to have occupied Denisova Cave for at least 300,000 years. Among the eight human fossils unearthed there are the pinkie, three bones from Neanderthals, and even one from a child with one Neanderthal and one Denisovan parent. The cave also contains sophisticated stone tools and jewelry at higher, later levels. But no modern human fossils have been found there. Those artifacts, extensive studies of DNA from these bones, and even one early study of DNA from soils have cemented the cave’s importance for piecing together human evolution.
But eight fossils are not much to go on, so Elena Zavala, a graduate student at the Max Planck Institute for Evolutionary Anthropology, and colleagues teamed up with Russian researchers to see what kind of DNA was present in the soils of the three-chamber cave.
Researchers have been studying DNA isolated from soils for more than 40 years, including sequencing DNA from permafrost, but only in the past 4 years has anyone found DNA from extinct humans in ancient soils.
Working with another team of experts who had previously dated the layers of the cave, the researchers dug out 728 soil samples. After 2 years of analysis, in which they isolated and sequenced the samples, the researchers found human DNA in 175 of them. That makes the study "the largest and most systematic of its kind," says Katerina Douka, an archaeological scientist at the Max Planck Institute for the Science of Human History who was not involved in the work.
The data reveal a complex history of human and animal habitation, with different groups moving in and out of the cave over time, Zavala and her colleagues report today in Nature. Their work confirms that Denisovans were the cave’s first human inhabitants, about 300,000 years ago. They disappeared 130,000 years ago, only to be followed by a different group of Denisovans, who likely made many of the stone tools, some 30,000 years later. Neanderthals appeared on the scene about 170,000 years ago, with different groups using the cave at various points in time, some overlapping with the Denisovans.
The last to arrive were modern humans, who showed up about 45,000 years ago. The soil layer that corresponds with that period contained DNA from all three human groups, the researchers report. "The time periods [of each layer] are quite large, so we can’t concretely say if they overlapped or not," Zavala says. But, Douka adds, "I cannot think of another site where three human species lived through time."
Given the jewelry and sophisticated artifacts in later layers, some researchers had suspected moderns had been there. But no one knew they had arrived as early as 45,000 years ago - and overlapped with both of our archaic cousins. "It suggests a more complicated interplay between archaic and modern humans," says Ron Pinhasi, an evolutionary anthropologist at the University of Vienna who was not involved with the work.
The soil samples also yielded DNA from many species of animals. About 170,000 years ago, the climate went from warmer to colder, and Neanderthals moved in, so did different species of hyenas and bears.
It’s the combination of genomic data from both the fossils and the soil samples that really makes the new work stand out, Pinhasi says. "It’s a superpromising direction [for future work]." Douka agrees, and says the new study should help ancient soil DNA become "a mainstream archaeological tool." She is already amazed at the progress that it, combined with other studies, has made possible. "Let’s not forget that as recently as in 2010 we had absolutely no evidence that Denisovans existed, and that these various hominins ever met, let alone that they interbred repeatedly and co-existed for millennia," she wrote in an email.
© 2021 American Association for the Advancement of Science. All rights Reserved.
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На территории России находится более одной пятой всех лесов мира, играющих огромную роль в смягчении последствий изменения климата. Совместное исследование ученых из России, Австрии, Новой Зеландии и Швейцарии показало, что за последние десятилетия в российских лесах произошло значительное увеличение растительности, древесного покрова и наземной биомассы. Соответственно, леса поглощают гораздо большее количество углекислого газа, чем считалось ранее.
Russia is the world’s largest forest country. Being home to more than a fifth of forests globally, the country’s forests and forestry have enormous potential to contribute to making a global impact in terms of climate mitigation. A new study by IIASA researchers, Russian experts, and other international colleagues have produced new estimates of biomass contained in Russian forests, confirming a substantial increase over the last few decades.
Since the dissolution of the USSR, Russia has been reporting almost no changes in its forests, while data obtained from remote sensing products indicate that Russian forests have in fact experienced an increase in vegetation productivity, tree cover, and above-ground biomass in the last few decades. This has led to inconsistencies in available data and a general decline in the reliability of information on Russian forests since 1988, which can be attributed to an information gap that appeared when Russia moved from the Soviet Forest Inventory and Planning system to its current National Forest Inventory (NFI) for the collection of forest information at the national scale. The first cycle of the Russian NFI was finalized in 2020. The authors of a new IIASA-led study published in Nature Scientific Reports have used this data in combination with research forest plots on the ground and remote sensing data in an advanced analysis to produce a new estimate of the biomass of Russian forests, confirming these forests’ climate change impact and their importance for climate change mitigation.
"We set out to determine the live biomass stock and sequestration rate of Russian forests. The joint efforts of our diverse team consisting of representatives from the Russian state forestry agency, forest survey, academic research institutes, and other educational institutions, made it possible for us to produce an important reproducible scientific result. Even more importantly, our work contributed to building mutual trust, a policy of data sharing, and hopefully, the potential for fruitful future collaboration," says study lead author Dmitry Schepaschenko, a researcher with the IIASA Agriculture, Forestry, and Ecosystem Services Research Group in the Biodiversity and Natural Resources Program.
The team were the first to be given access to a portion of primary NFI plot data with precise location information, which, as in many other countries, is normally restricted for sharing and use, under the condition that the initial data processing was physically undertaken on site at the authorized division ("Roslesinforg") of the Federal Forestry. The researchers used this data in combination with remote sensing data to estimate the growing stock of Russian forests and to assess the relative changes in post-Soviet Russia. They calibrated models relating to two global remote sensing biomass data products and additional remote sensing data layers with around 10,000 ground plots from the NFI and the Forest Observation System to reduce uncertainties and produce an unbiased estimation at jurisdictional level. By combining these two sources of information, the team were able to utilize the advantages of both sources in terms of highly accurate ground measurements and the spatially comprehensive coverage of remote sensing products and methods.
"Quite often, practitioners simply use linear regression by default without checking the underlying statistical assumptions or worrying about the difference between the ability of a model to explain the observed data and the ability to predict the future or unobserved data. Because the aim of this study was to estimate the unobserved biomass, we have used modern computationally intensive methods to focus on the goodness-of-prediction of a range of plausible models," explains study coauthor and long-time IIASA collaborator, Elena Moltchanova from the School of Mathematics and Statistics at the University of Canterbury, New Zealand.
The findings indicate that Russian forests have in fact accumulated a large amount of biomass - in the range of 40% more than the value recorded in the country’s State Forest Register and reported to the statistics of the Food and Agriculture Organization of the United Nations (FAO). Using the last Soviet Union report as a reference, the results show that the growing stock accumulation rate in Russian forests between 1988 and 2014 is of the same amplitude as the net forest stock losses in tropical countries. The study’s estimate of carbon sequestration in live biomass of managed forests between 1988 and 2014 is 47% higher than reported in the National Greenhouse Gases Inventory.
The authors note that while Russian forests and forestry have great potential in terms of global climate mitigation as well as numerous potential co-benefits relating to the green economy and sustainable development, it is important to highlight that as the climate becomes more severe, as in recent years, resulting forest disturbances might nullify these gains. Close collaboration of science and policy would therefore be critical to elaborate and implement adaptive forest management.
"We are talking here about the largest country in the world hosting the largest share of the largest land biome globally - the circumboreal belt of forest - which is highly climate relevant. Imagine what just a few percent up or down with regard to the amount of forest biomass available and its consequent carbon sequestration potential can make globally," says Agriculture, Forestry, and Ecosystem Services Research Group Leader and study coauthor, Florian Kraxner. "This study once again highlights the important work done by researchers of the International Boreal Forest Research Association (IBFRA), which we would like to acknowledge particularly," he concludes.
Shchepashchenko, D., Moltchanova, E., Fedorov, S., Karminov, V., Ontikov, P., Santoro, M., See, L., Kositsyn, V., et al. (2021). Russian forest sequesters substantially more carbon than previously reported. Scientific Reports 11 (1) e12825. DOI: 10.1038/s41598-021-92152-9 [pure.iiasa.ac.at/1720]
© International Institute for Applied Systems Analysis (IIASA).
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Коллектив ученых из Томского политехнического университета, Новосибирского института органической химии им. Н.Н.Ворожцова СО РАН, Института органической химии имени Н.Д.Зелинского РАН, Института химической кинетики и горения им. В.В.Воеводского СО РАН и Международного томографического центра СО РАН синтезировал уникальную молекулу вердазил-нитроксильного трирадикала. Подобные органические магнитные соединения со временем могут заменить в электронике кремний и металлы, но пока получить молекулы с такими свойствами удалось лишь нескольким научным коллективам.
Scientists of Tomsk Polytechnic University jointly with their colleagues have synthetized a unique molecule of verdazyl-nitronyl nitroxide triradical. Only several research teams in the world were able to obtain molecules with similar properties. The molecule is stable. It is able to withstand high temperatures and obtains promising magnetic properties. It is a continuation of scientists' work on the search for promising organic magnetic materials. The research findings are published in the Journal of the American Chemical Society (IF: 14.612, Q1).
Magnetoresistive random-access memory (MRAM) is one of the most promising technologies for storage devices. Nowadays, the MRAM development is limited due to the fact it is impossible to create a smaller memory cell because of spontaneous magnetization reversal. Single-molecular magnets based on organic compounds are free from this disadvantage: few molecules are already capable to operate as a memory storage unit.
"At a certain temperature, a magnetic phase transition occurs, the consistent orientation of the magnetic vectors of molecules is observed, as a result, the matter becomes a united magnet. Thus, 20-40 molecules are quite enough to form a micromagnet.
Our task in the research laid in creation such a molecule that could be capable to give its magnetic properties at high temperatures, would be crystalline and would possess a small distance between radical centers,"
Pavel Petunin, Associate Professor of the TPU Research School of Chemistry and Applied Biomedical Sciences, an article author, explains.
When creating the molecule, the scientists worked with three radical centers in one molecule combined them in one conjugated structure. To synthetize the molecule, the scientists used a palladium-catalyzed reaction of a verdazyl radical with a gold complex of a nitronyl-nitroxyl radical. The course of the reaction was complicated due to the presence of unpaired electrons in starting compounds, as well as the combination of three radical centers in one molecule, which affects its stability. According to the scientists, there are no other ways to synthesize the molecule.
The research teams from TPU, the Vorozhtsov Novosibirsk Institute of Organic Chemistry of the Siberian Branch of Russian Academy of Sciences, the Zelinsky Institute of Organic Chemistry of the Russian Academy of Sciences, the Voevodsky Institute of Chemical Kinetics and Combustion of the Siberian Branch of the Russian Academy of Sciences and International Tomography Center of the Siberian Branch of the Russian Academy of Sciences took part in the molecule synthesis. The research work was conducted within the project of the Russian Science Foundation No. 20-73-00236 "Stable Organic Radicals as Promising Building Blocks for New Materials".
"The published research not only makes a significant contribution to the development of stable verdazyl radicals but it is also a meaningful publication for TPU. Research teams of the TPU Research School of Chemistry and Applied Biomedical Sciences perfectly complete the mission, which was determined at the moment of the School creation. The Journal of the American Chemical Society is the most peer-reviewed chemical journal. Research teams around the globe are intending to publish their articles in this journal. It should be noted that it is a cycle of the research works of the research team. The authors have recently published their research work in the equally top-rated Angewandte Chemie academic journal (IF: 12.959, Q1)," Marina Trusova, Director of the TPU Research School of Chemistry and Applied Biomedical Sciences, says.
At the moment, the researchers have approached complicated molecules and are planning to synthetize almost impossible molecules: heterospin and high-spin dendrimers.
Copyright © 2021 by the American Association for the Advancement of Science (AAAS).
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Ars Technica / 6/28/2021
Why is Russia launching a new module to the space station if it’s pulling out?
Nauka will be the largest module the Russians have sent to the ISS.
Модуль Международной космической станции «Наука», запуск которого запланирован на 15 июля этого года, станет первым крупным российским компонентом за последние 10 лет. Однако автор статьи задается вопросом, зачем запускать такой большой модуль после того, как Россия заявила о своем возможном выходе из программы МКС уже после 2025 года.
The Russian space corporation, Roscosmos, released photos on Monday showing the much-anticipated Nauka space station module enclosed in its payload fairing. This will be Russia's first significant addition to the International Space Station in more than a decade, and it will provide the Russians with their first module dedicated primarily to research. "Nauka" means science in Russian.
This is a sizable module, including crew quarters, an airlock for scientific experiments, and much more. With a mass of about 24 metric tons, it is about 20 percent larger than the biggest Russian segment of the station, the Zvezda service module.
The timing for this launch, scheduled for as early as July 15 on a Proton rocket, is notable. For one, the multi-purpose Nauka module is more than a dozen years late due to a lack of budget for the project on top of technical issues. At times, it seemed like the module was never actually going to launch.
Additionally, Russia is launching its largest module at a time when its future participation in the International Space Station program is uncertain. Russian officials have said the existing hardware on orbit, much of which is more than two decades old, is aging beyond repair. The Russians have said they may pull out of the program in 2025 and build a brand-new station.
So why launch a new module just a few years before exiting the station? One possibility is that the Russians are simply posturing. Some NASA officials have speculated privately that this may be an angle to obtain new funds from the United States. With the success of SpaceX's Crew Dragon vehicle and nearing availability of Boeing's Starliner, NASA is no longer annually sending hundreds of millions of dollars to Roscosmos to purchase Soyuz seats for access to the station. This was an important source of funding for Russia's space program.
However, NASA would like to keep the station flying for another decade, and for this it needs the Russians. The first elements of the International Space Station were launched in 1998, and it was designed such that the US and Russian segments were dependent upon one another for attitude control, power, and other critical resources. The NASA officials suspect Russia may seek "maintenance" funding from the United States in return for keeping its part of the space station going.
Nauka's launch is an important symbolic win for Russia's space program, in that it is increasingly rare for Roscosmos to develop and fly new hardware. Mostly, the program maintains and launches decades-old spacecraft such as the Soyuz vehicle and the Proton rocket.
After being encapsulated in its payload fairing, Nauka will now move to a "filling station" at the Baikonur Cosmodrome in Kazakhstan, where it will be fueled and pressurized. After that, it will be mated to its Proton rocket for a launch that may occur as soon as July 15.
© 2021 Condé Nast. All rights reserved.
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