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Les Échos / Le 01/11/2015
Les mammouths ont disparu parce qu'ils avaient de l'ostéoporose
Проанализировав около 23500 костей мамонтов Северной Евразии, руководитель лаборатории континентальных экосистем мезозоя и кайнозоя Томского государственного университета Сергей Лещинский выдвинул новую гипотезу о причине их вымирания - геохимические изменения среды обитания. В какой-то момент мамонтам стало не хватать жизненно необходимых химических элементов. Сильнейший минеральный голод привел к массовым патологиям костей, высокой травматичности и быстрой гибели.
Статья «Enzootic diseases and extinction of mammoths as a reflection of deep geochemical changes in ecosystems of Northern Eurasia» опубликована в журнале Archaeological and Anthropological Sciences.
Il y a 12.000 ans s'éteignaient les mammouths. Cette disparition a suscité bien des questionnements. Des scientifiques russes ont peut-être la réponse.
Changements climatiques, maladies, bouleversements géologiques, ou simplement les humains... Plusieurs théories sur l'extinction des mammouths en Eurasie ont déjà été soulevées. Mais celle-ci pourrait vous étonner : l'ostéoporose.
Selon des chercheurs russes qui étudient la question depuis plus de 15 ans, les éléphantidés ont souffert d'une véritable « famine minérale ». En analysant quelque 23.500 ossements et dents de mammouths, ils ont découvert des squelettes endommagés. Cela n'était pas dû à des traumatismes.
Des os « défigurés par la maladie »
Peu importe l'âge de la bête, les os étudiés étaient ramollis, balafrés, ou cassants. Pire, dans deux cimetières de mammouths, les scientifiques ont établi que 90% des animaux avaient souffert d'une maladie des os (ostéoporose, mais aussi ostéofibrose, ostéomalacie ou arthrose).
Responsable de cette étude de l'Université de Tomsk, Sergueï Lechtchinski précise que « les surfaces articulaires des os des extrémités de certains spécimens ne sont pas simplement endommagés, mais défigurés par la maladie ».
Selon lui, l'ostéoporose entraînait des foulures et des fractures. Ensuite, les mammouths dont le squelette était endommagé ne pouvaient pas trouver suffisamment de nourriture et ils n'étaient plus capables de suivre le troupeau. Distancés par leurs congénères et affaiblis, ils devenaient des proies faciles.
Ils mangeaient à leur faim
La cause de cette épidémie d'ostéoporose : le sol, qui est devenu de moins en moins riche en minéraux. Les mammouths, qui avaient l'habitude de se retrouver autour de certains points d'eau pour manger de l'argile et boire de l'eau boueuse, ont vu leur apport en sodium, magnesium, calcium et phosphore diminuer drastiquement.
Ces minéraux étaient essentiels au bon fonctionnement de leur corps. Malheureusement, vers la fin de l'époque géologique du Pléistocène, ces petits oasis de minéraux ont commencé à disparaître à cause de changement géologiques radicaux.
Petit à petit, le niveau des océans s'est élevé et les plaines ont été englouties. En altitude, ce sont les fortes pluies qui ont chassé les minéraux hors du sol. C'est ainsi que les mammouths - même s'ils mangeaient à leur faim - sont morts de famine. Une famine minérale.
Tous droits réservés - les echos 2015.
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SpaceFlight Insider / November 1st, 2015
Russia hopes to land humans on the Moon in 2029
Российское космическое агентство планирует пилотируемый полет и высадку человека на Луну в 2029 г.
Russia's growing interest in the Moon manifests itself in more and more bold announcements regarding the future manned landing on the lunar surface. On Tuesday, Oct. 27, one of the country's top space industry officials, Vladimir Solntsev, revealed that Russia aims to land a man on the Moon in 2029.
"A manned flight to the Moon and lunar landing is planned for 2029," said Solntsev, the head of the RKK Energia company.
RKK Energia is the manufacturer of spacecraft and space station components. The company is the prime developer and contractor of the Russian manned spaceflight program.
Solntsev said that Russian scientists in Moscow are building a new spacecraft made of composites specifically for Moon missions. Its first flight is scheduled for 2021. Two years later, the vehicle will be sent to the International Space Station (ISS), and in 2025 it will complete an unmanned lunar mission.
Russia also plans to send a lunar polar lander around 2024, named Luna-25, or Luna-Glob lander. It will be the country's first step toward the creation of a fully robotic base on the Moon. Currently, five Luna missions are planned. The European Space Agency (ESA) has lately expressed interest in Russian efforts to colonize the Moon. The agency said it would offer key technical expertise for future lunar missions.
ESA also hopes that a possible cooperation with Russia could help the agency send European astronauts to the Moon.
"We have an ambition to have European astronauts on the Moon. There are currently discussions at [an] international level going on for broad cooperation on how to go back to the Moon," said Bérengère Houdou, the head of the lunar exploration group at ESA's European Space Research and Technology Centre (ESTEC).
Tuesday's announcement coincides with the start of the Russian isolation experiment Luna-2015 (Moon-2015) at the Institute for Biomedical Problems (IBMP) of the Russian Academy of Sciences. The experiment simulates an eight-day-long flight from the Earth to the Moon and aims at testing the psychology and physiology of female humans - as the crew consists of six women.
RKK Energia said that its specialists will closely study the results of this experiment and, possibly, will take them into account when developing the hardware to support a manned lunar mission.
"Our specialists will conduct a detailed analysis of all the data obtained in the Luna-2015 experiment. We hope that this will help us improve the characteristics of the habitable environment inside the hardware which is being developed to deliver man to the Moon, as well as thoroughly work out the issues of medical and biological support for the missions," said Mark Serov, the head of the flight testing department at RKK Energia.
The last Russian unmanned mission to the Moon, Luna 24, landed on the lunar surface on Aug. 18, 1976. It was also the last spacecraft to make a soft landing on the Moon until the landing of China's Chang'e 3 on Dec. 14, 2013.
In 1989, the Soviet Union officially acknowledged the existence of its manned lunar program. The USSR and Russia have so far failed to land cosmonauts on the Moon.
© 2013-2015 Spaceflight Insider.
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Popular Mechanics / Nov 4, 2015
5 Places Russia Will Send Its Space Probes Next. To the Moon, Mars, and beyond
Пять мест в космосе, куда Россия планирует отправить исследовательские аппараты в ближайшее десятилетие. Насколько реалистичны сроки и каковы шансы на успех?
NPO Lavochkin, Russia's premier manufacturer of unmanned planetary probes, just refreshed its wish list. The company outlined a series of robotic missions into the Solar System approved for development and launch in the next decade. This is one seriously ambitious plan - especially if one remembers that not a single Russian probe have made it beyond the Earth's orbit since the collapse of the USSR more than two decades ago.
Still: If even half of the goodies on the list make it to the launch pad, it would be a true renaissance of the Russian planetary exploration. So here are a few highlights from the menu, and a few comments on each mission's realistic timeframe and chances for success.
The Moon: Touching Ice
NPO Lavochkin hopes to jump-start its deep-space program around 2019 by visiting the moon, the closest destination possible. But Russian scientists did not make it easy for themselves.
They plan to land the first of three probes, called Luna-Glob, near the lunar south pole, where suspected deposits of water ice might have been buried for eons. Touching the lunar water ice would be a huge deal not only for planetary geology but also for the future of human space exploration, as many people planning or imagining future missions would love to tap into local resources to cut down how much spacecraft have to carry with them. Some incurable optimists even hope to use the lunar water to convert it into oxygen and liquid hydrogen to refuel departing rockets.
If successful, Luna-Glob would pave the way to a more sophisticated lander and to a mission to return soil samples from the Moon in the second half of the 2020s. In the next step, an international robotic base could be built near the south pole by the end of 2020s, inhabited by rovers, geological sensors, telescopes and, possibly, the first experimental machines to convert lunar ice into hydrogen fuel. Finally, in the 2030s, Russian cosmonauts might finally arrive for a visit to establish the first permanent human foothold on another world.
Will it happen? Given Lavochkin's history and the company's current commitments, we'd consider the 2019 launch date for the first Luna-Glob a bit too optimistic. But with all the recent international attention, the mission does have a good chance to fly at the turn of the new decade.
Mars: The Life Question
One of the reasons we think Lavochkin's moon missions might have to wait is because the company's involvement in the ExoMars 2018 project. ExoMars will be perhaps the most sophisticated attempt to answer a seemingly eternal question whether there is, or ever has been, life on Mars. Europe will supply a rover wielding a drill capable of penetrating up to two meters into the Martian soil. But it will be Lavochkin's job to gently take the rover through the riskiest phase of a parachute descent and rocket-propelled landing on Mars using a custom-built four-legged platform.
Will it happen? Not counting the very first Soviet Mars-3 lander in 1971 - which survived on the Martian surface for a few seconds and then fell silent, only to be rediscovered by satellites images in 2012 - Russia has never quite succeeded at landing on Mars, suffering through a string of failures and bad luck. Still, ESA had no choice but to turn to Russia for this project after NASA suddenly (and some allege intentionally) withdrew from the joint project. Yet even with a free ride on the Russian Proton rocket, ExoMars faces serious technical and financial challenges. We wouldn't recommend betting a huge amount of money on its planned launch really going off in 2018. And because of the unforgivable orbital mechanics of missions to Mars, even a minor delay would mean a two-year wait until 2020.
Boomerang: Bringing Back a Piece of Mars' Moon
If ExoMars does succeed - and even if it doesn't - Russia hopes to build upon its partnership with Europe to send another mission into the orbit of Mars around 2024. The Boomerang probe would land on the Martian moon Phobos, scoop its soil, and then fly its precious cargo back to Earth.
Will It Happen? If this mission scenario sounds familiar, that is because the Boomerang is a successor to the disastrous Phobos-Grunt spacecraft, which got stranded in the Earth's orbit just hours after its launch in November 2011. This time, however, the redesigned mission will stand on the shoulders of the ExoMars experience and have much broader international team of engineers behind it. In turn, the Boomerang project could lead to soil sample return from Mars itself, moving earthlings ever closer to resolving the mystery of life on the Red Planet.
Laplas: A Longshot to Ganymede
Even the mighty Soviet space program never ventured beyond Mars. But now, Russian scientists hope to send a mission called Laplas (after French scientist Pierre-Simon Laplace) all the way to Jupiter's system in 2026. Most importantly, the spacecraft should involve the world's first lander to touch down on Jupiter's mighty (and possibly watery!) moon Ganymede.
Will it happen? The official launch date for the Laplas mission is not an accident. The 2026 plan places Laplas beyond the 10-year Federal Space Program of the Russian Federation, which is expected to be approved this month and cover all Russian space activities from 2016 to 2025. A spacecraft as complex as this one will take a long time to build and will doubtlessly be subjected to technical delays and budget problems along the way. Therefore, it is a long-shot project we cannot realistically expected to lift off before the end of the 2020s. Add to that a nearly decade-long travel time to Jupiter and we're talking about a spacecraft that won't actually land on Ganymede until the end of 2030s.
InterGelioZond: Burn by the Sun
The InterGelioZond is designed to approach the Sun as closely as possible without melting itself. A special thermal shielding will be required to protect onboard equipment from the searing heat of our star, while simultaneously enabling sensors to probe the environment. Solar panels would also have to work but not melt, making the whole project a major engineering challenge.
Will it happen? Realizing what a tough nut they would have to crack, planners pushed the mission until after 2025. We say add another five years to that date.
© 2015 Hearst Communications, Inc. All Rights Reserved.
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Maritime Professional / November 12, 2015
Snow storms, Earthquakes - Scientists to Predict
Ученые из Мурманского государственного технического университета разработали метод раннего прогнозирования землетрясений на основе данных об изменениях атмосферы. Уже давно было замечено, что за несколько дней до землетрясения в ионосфере на высоте 200-500 км над будущим эпицентром заметно изменяется концентрация заряженных частиц. Мурманские ученые выявили механизм формирования этой аномалии и разработали модель, способную анализировать и воссоздавать различные атмосферные процессы.
Russian scientists have demonstrated the ability to predict earthquakes, typhoons and snowstorms on the changes of the atmosphere.
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"These experiments allow satellite data on the state of the atmosphere to detect the earliest stages of seismic processes which result in a strong, six points above, earthquakes, and predict them," - said the Doctor of Physical and Mathematical Sciences, Chief Scientific Officer of the Murmansk State Technical University Alexander Namgaladze.
The accumulated data of satellite and ground observations of the ionosphere (upper atmosphere) showed that during the preparation of major seismic events of their hubs at altitudes of 200-500 km recorded abnormal change in the composition of the atmosphere - a significant increase or decrease in the concentration of charged particles does not depend neither on other reasons. This phenomenon was given the name "Ionospheric precursors to earthquakes" (anomalies appear a few days before seismic events).
For final confirmation of the possibility to predict the earthquake was not enough just to explain the mechanism of formation of these anomalies to uniquely link the processes in the air and the ground. This mechanism has been identified in the last several years of research by computer physical and mathematical model of the upper atmosphere of the Earth, developed by a group of scientists led by Namgaladze. This model is generally created a few decades, it has no analogues in Russia and abroad and is able to analyze in detail and simulate a variety of processes in the Earth's atmosphere, according to Tass.
Further research will be directed at the development of practical methods of earthquake prediction. "These anomalies may occur sometimes before the volcanic eruptions, dust storms, typhoons, and, more important for the Arctic and subarctic regions, blizzards and storms, which can also be predicted," - said Namgaladze.
Spaceflight Now / November 12, 2015
U.S.-Russian talks on Venus mission resume
NASA и Роскосмос вернулись к обсуждению задуманной несколько лет назад совместной миссии на Венеру. За основу предполагается взять российский проект «Венера-Д» - автоматическую межпланетную станцию, которая должна будет исследовать состав атмосферы, поверхность планеты и выяснить причины исчезновения с нее воды.
NASA has resumed discussions with Russia on a potential joint robotic mission to Venus in the late 2020s after the Ukraine crisis stalled the partnership, according to scientists involved in the talks.
Russian scientists have studied the Venera-D mission to Venus more than a decade as a follow-up to the Soviet-era Venera and Vega probes to the second rock from the sun.
Rob Landis, a program executive at NASA Headquarters, told a meeting of the Venus Exploration Analysis Group last month that the discussions are taking a "100,000-foot view" of the mission.
NASA has only committed to a year-long feasibility study, which will produce a report for top NASA and Russian managers to decide whether to pursue a cooperative mission to Venus, Landis said Oct. 27 at the VEXAG meeting in Washington. The joint science definition team met in Moscow from Oct. 5-8, and scientists plan two more face-to-face meetings in the Russian capital over the next year. Scientists from the Moscow-based Space Research Institute, known by the Russian acronym IKI, are in charge of the Venera-D concept.
Russian officials envision the Venera-D mission as a combined orbiter and lander. Scientists are also studying whether the mission could accommodate a balloon to loiter in the Venusian atmosphere for several days, measuring the sweltering planet's climate patterns and winds.
"We made a lot of progress," said David Senske, a scientist at NASA's Jet Propulsion Laboratory who is the U.S. co-chair of the Venera-D science definition team. "We heard a lot about what they had in mind. We've been told this is an IKI/Roscosmos endeavor, so they're in the driver's seat."
Senske said the U.S. role in the science definition team is to steer the Venera-D mission's objectives toward addressing NASA priorities and answering questions posed by the last planetary science decadal survey, a document published by the National Research Council that guides U.S. solar system exploration.
The October meeting came after the potential Venera-D partnership was put on hold following Russia's annexation of Crimea in early 2014. A U.S. government directive for NASA to curtail its cooperation with Russia in April 2014 excluded large projects, such as the International Space Station and Russia's research instrument aboard the Curiority Mars rover. But the policy forced the Venera-D science definition team to suspend their work before it even started.
"Almost two years ago, NASA and Roscosmos decided to stand up a joint science definition team," Senske said. "We had just gotten our work going when we were told stand down, but in August (of) this year, we were told we were back in business again."
Russia's federal space program initially included the Venera-D mission as a core component, assuring the project of Russian government funding. But Senske said the Russian space agency, Roscosmos, has now asked scientists to formally propose the Venera-D mission before it will be considered for full development. NASA participation in the mission could reduce Venera-D's cost to the Russian government, and IKI scientists have scaled back the scope of the mission. The mission includes a spacecraft in a 24-hour orbit around Venus, and a probe that will descend through the planet's smothering atmosphere and operate on the surface for up to several hours. Russian scientists initially planned a more sturdy lander - the "D" in Venera-D stands for the Russian word for long-lived - but designing and building a spacecraft to survive for multiple days on Venus turned out to be too costly.
"When they looked at that in detail, they discovered that was a bridge too far. They wanted to get 24 hours or more (from the lander), but in order to fit into their cost envelope, they're looking at more of a Vega-type lander," Senske said, referring to the Soviet Union's Vega missions to Venus in the 1980s.
Russia's last Venus missions launched in 1984 after launching a series of Venus probes beginning in 1961.
The Venera-D lander would likely focus on atmospheric observations, surface imagery and composition measurements, and searching for volcanic activity. Venera-D's orbiter would look at Venus' upper atmosphere, cloud patterns, super-rotating winds and the planet's runaway greenhouse effect, which gives Venus surface temperatures of nearly 900 degrees Fahrenheit (nearly 500 degrees Celsius).
Launch of the Venera-D mission will not occur before 2025, according to Lev Zelyony, IKI's director, who was quoted in a story by Russia's Interfax news agency.
Tasks for the science definition team include identifying the Venera-D mission's science goals and technological needs. The discussions will also determine what NASA could contribute to the mission, assuming it goes forward.
A final report from the science definition team to NASA and IKI is due Sept. 30, 2016.
© 2015 Spaceflight Now Inc.
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ScienceInsider / 16 November 2015
Stung by 'foreign agents' law, Russian scientists regroup
Готовится к работе новый просветительский фонд «Эволюция». Идея его создания появилась летом, а осенью были предприняты уже конкретные шаги. Одним из учредителей выступила АНО «Троицкий вариант». Прежде всего фонд планирует заняться переводом и изданием иностранной научно-популярной литературы, а также поддержкой и координацией различных просветительских мероприятий.
MOSCOW - Hoping to a fill a void left by the closure last summer of Russia's only private research funder, scientists here are gearing up to launch a new foundation. But the nonprofit, called Evolution, has set modest ambitions: Initially it will focus only on science popularization.
These are difficult times for nonprofit organizations in Russia. Over the past 3 years, the government labeled several dozen organizations "foreign agents," questioning their motives and imposing restrictions on their activities. Recent designees include the MacArthur Foundation, the Open Society Foundations, and the Dynasty Foundation, backed by the Russian telecommunications tycoon Dmitry Zimin.
Established in 2002, Dynasty spent some $30 million over 13 years on seed money for young Russian scientists and on competitions for science teachers, science festivals, and public lectures by world-class researchers. It ran afoul of the foreign agents law because Zimin bankrolled the foundation with funds held outside Russia. Dynasty's tarring last May was a blow to Russia's scientific community: Zimin pulled the plug on his support, forcing the foundation to wind up its activities in July.
Rueing Dynasty's demise, a group of scientists behind the independent newspaper Troitsky Variant, the tribune of Russia's scientific community, set out in August to create a successor. "The original idea was to continue and extend what Dynasty had been doing," says Evolution board member Mikhail Gelfand, a biologist here at the Institute of Information Transmission Problems. But fundraising has proven daunting. So far, Evolution has managed to raise tens of thousands of dollars - "a drop in the ocean" compared with Dynasty's budget, says Troitsky Variant chief editor Boris Shtern here at the Institute for Nuclear Research.
After recalibrating its aspirations to the size of its war chest, the foundation now intends to translate into Russian science nonfiction books from abroad, including children's literature, publish Russian science authors, and organize science festivals in the hinterlands, far from the science powerhouses of Moscow, St. Petersburg, and Novosibirsk. The foundation intends to support some of its activities through crowdfunding, says spokesperson Lilia Sabirova. Evolution's coming out party will be later this month here at the VDNH book fair.
Although Evolution is starting small, "It is hard to overestimate the symbolic importance of the new foundation," Shtern says. "For the first time ever in the world," he says, "researchers united to replace an organization they had been deprived of."
© 2015 American Association for the Advancement of Science. All Rights Reserved.
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Science Codex / November 17, 2015
Mitochondria on guard of human life
Биологи, химики и материаловеды из МГУ совместно с немецкими и датскими коллегами разработали метод исследования митохондрий, позволяющий изучить перенос электронов между митохондриальными мембранами и белковым комплексом цитохром С, не разрушая при этом сами митохондрии. В основе метода лежит поверхностно-усиленная рамановская спектроскопия, которая давно используется в физических и химических экспериментах, но попытки изучать с ее помощью живые клетки до сих пор были неудачными.
Статья «Probing cytochrome c in living mitochondria with surface-enhanced Raman spectroscopy» опубликована в журнале Scientific Reports.
A group of researchers from Lomonosov Moscow State University in collaboration with Russian Science Foundation developed a unique method for the selective study of electron transport chain in living mitochondria by using nondestructive analysis. The study was published in Scientific Reports.
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Mitochondria are organelles of fundamental importance for cellular energy production and are often described as "the powerhouse of the cell". Mitochondria generate adenosine triphosphate (ATP), used as a universal source of chemical energy. The main role in the process of ATP synthesis belongs to the transport of electrons between special proteins in the inner mitochondrial membrane, one the most important of which is called cytochrome c.
Mitochondria are of a special interest for scientists because these organelles contain mtDNA - molecules that carry maternally inherited genetic information. From this point of view mitochondria are a very interesting object of research for genetic and health scientists, whose field of work lies in the area of genetic disorders.
According to Nadezda Brazhe from the Department of Biophysics (Biological Faculty, Moscow State University), there are many methods of mitochondria study, but even the most advanced and sophisticated cannot provide detailed information about the processes that occur inside and in between mitochondrial membranes during the electron transport.
Researchers from Moscow State University suggested a novel and promising approach based on the surface-enhanced Raman spectroscopy (SERS). During last decade this method becomes more popular in studies of molecule properties in a tube and inside living cells.
There are two types of light scattering: Rayleigh scattering (or elastic scattering) does not influence on the state of photon that falls off the obstacle without changing its frequency, and Raman scattering (or inelastic scattering), when photon interacts with molecules changing their energy level. As a result, photon frequency also changes and photon carries away some information about the encountered molecule. This information can potentially be used for the further study of the molecule.
Physicists developed the method that permit to separate photons of Raman and Rayleigh scattering with the help of special spectrometers, but inelastic collisions occur extremely rarely. That is why combinational (Raman) scattering turns out to be weak and low intensive, which makes it almost undetectable.
The problem was solved in 1974 when an unusual effect was discovered: if the object that scattered Raman photons was located in close proximity to nanostructured metal surface, the scattering billionfold intensified. Researchers still cannot give a full explanation of this phenomenon, but they suggest that this effect occurs due to plasmons - quasiparticles, which represent surface electron oscillations relatively to positively charged nuclei of nanostructure's metal. If the frequencies of plasmon and Raman photon coalesce, the resonance is produced, which helps to make almost undetectable processes visible. This effect gave birth to a specific type of spectroscopy - SERS.
Biologists who study biomacromolecules understood that this type of spectroscopy could be a perspective way to study function of molecules inside living organelles or cells without destruction. From the middle of 2000th biologists tried to implement the method in practice, but not all attempts were successful.
According to Nadezda Brazhe, the main reasons of failure were related to inefficiency of nanostructures. Thousands of nanostructured surfaces were invented, but some of them were not capable to create resonance on the frequencies needed, the others turns out to be toxic for mitochondria or degraded when put into physiological fluids.
"Biologists, chemists and physicists were involved into our work. This cross-disciplinary approach made our success possible - we were able to create nanostructured surfaces and new methodological approach to study mitochondria. Success would be impossible without our colleagues from MSU Department of Material Science, - says Nadezda Brazhe. - Young researchers from group of Prof. Eugene Goodilin after long and careful examinations found appropriate and non-toxic nanostructure, which allowed us to complete the work".
The work lasted several years and was very difficult both for biologists and for nanochemists. Sometimes an achieved result seemed to be a miracle - but a miracle that can be explained from a scientific point of view.
The final result turned out to be surprisingly simple: diluted mitochondria sample was placed on the nanostructured silver surface; laser light was focused on mitochondria aggregated on nanostructures and SERS spectra of cytochrome c inside living mitochondria was recorded. After that researchers analyzed the SERS spectra. It turned out that only Raman scattering from cytochrome c experiences manifold enhancement. Therefore, the researchers had the chance to see in details the changes in cytochrome c structure that occur in process of electron transport and ATP synthesis. With the use of different agents, scientists could initiate and stop electron transport and ATP synthesis in mitochondria, and these changes were well detectable in recorded spectra.
No epoch-making discoveries were made during the work. Nevertheless, scientists developed a method, which permits to make such discoveries. The use of the method is now available for everybody, and Brazhe and her colleagues want to continue their work.
"Our next step will be to analyze mitochondria taken from heart and skeletal muscle of rats with cardiovascular diseases and diabetes. We hope that the results of the work will help to develop a method for the early diagnostics of pathologies. It will help to start the disease treatment earlier and to make medication more efficient", - says Nadezda Brazhe.
History.com / November 18, 2015
DNA in Tooth Yields New Insight Into Ancient Human Cousin
Международный коллектив археологов, антропологов и генетиков представил новые результаты исследования находок из Денисовой пещеры - двух зубов. Генетический анализ подтвердил, во-первых, что зубы также принадлежали денисовскому человеку (точнее, двум разным людям с разницей в возрасте примерно 60 тысяч лет), а во-вторых, что денисовцы действительно существенно отличались и от неандертальцев, и от Homo sapiens.
Статья "Nuclear and mitochondrial DNA sequences from two Denisovan individuals" опубликована в журнале PNAS.
Back in 2010, Russian scientists identified a tiny finger bone and one tooth found in a Siberian mountain cave as belonging to members of an ancient hominid group previously unknown to science. The Denisovans, as they were called, were thought to have lived some 50,000 years ago, at the same time when early modern humans shared the world with Neanderthals, another now-extinct branch of the human family tree. Now, analysis of another tooth found in the cave has revealed much more about this mysterious human cousin.
A new study, published earlier this week in the journal Proceedings of the National Academy of Sciences, represents a key step in scientists' understanding of the Denisovans, an ancient hominid group that interbred with early modern humans. In 2008, scientists discovered a tiny finger bone and a few teeth in Denisova cave, located in the Altai Mountains in southern Siberia. Two years later, a team of Russian scientists identified the bone and one of the teeth as belonging to members of the same previously unknown human relative; they called the new group the Denisovans (pronounced "De-NEE-soh-vens") after the cave where the remains were found.
Analysis of the finger bone and tooth showed the specimens to be at least 50,000 years old. The Denisovans' closest relatives, the scientists found, were the Neanderthals, a hominin species that lived in Europe and western Asia between 300,000 and 40,000 years ago. Despite common origins, they concluded that the Denisovans were almost as genetically distinct from Neanderthals as Neanderthals were from living people. DNA analysis showed that the Denisovans had made their mark on modern humans, contributing some 5 percent of their DNA to the genomes of present-day Melanesians, who live in Papua New Guinea and other Pacific islands, and around 0.2 percent to the genomes of Native Americans and mainland Asians.
Because there were so few known Denisovan remains, however, scientists have been limited in what they could determine about the group, which they have not yet definitively called a species. The new study focuses on analysis of a second tooth, uncovered deep in the back of the Denisova cave in 2010. Researchers found that the new tooth, dubbed Denisova 8, bore striking similarities to the previously analyzed Denisovan tooth, while both were significantly different from the teeth of Neanderthals and modern humans. Both teeth were large, with sizeable roots, indicating that their owners must have had very large jaws. In addition, the new tooth showed only half the amount of genetic mutations as the other tooth and the finger bone. Using this evidence, geneticists concluded that the tooth was around 110,000 years old, as many as 60,000 years older than the other two specimens.
DNA analysis of the new tooth, combined with that of the earlier tooth and finger bone, revealed that the three specimens belong to three different individuals, all Denisovians. As a result, the scientists were able to examine genetic variation among Denisovians for the first time. Although all three remains were found in a single cave, they marveled, the Denisovans appeared to have almost as much genetic diversity as modern Europeans, and were far more genetically diverse than Neanderthals. This conclusion suggests that Denisovans either lived near the cave between 110,000 and 50,000 years ago, or that they came into the region at least twice - either way, the group appears to have been much larger, and to have flourished for much longer, than previously believed.
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University World News / 19 November 2015
Government plans incentives to lure foreign scientists
Правительство России планирует создать условия для привлечения иностранных ученых в качестве преподавателей в национальные университеты с целью повышения качества российского образования и улучшения его имиджа на мировой арене. В долгосрочной перспективе доля иностранного преподавательского состава в вузе должна будет достигать не менее 10%.
The Russian government plans to create conditions for attracting foreign scientists to national universities, with the aim of improving the quality and raising the image of the national system of higher education in the international arena.
Particular attention will be paid to attracting scientists of Russian origin working abroad.
According to state plans, in the long-term the share of foreign scientists among teaching staff of each leading Russian university should not be less than 10%.
Russia's President, Vladimir Putin, said: "The Russian government should create conditions for the attraction of leading foreign scientists to teach at technological faculties of Russian universities. The existing programme of mega grants could be considered as one of the incentives for foreigners to teach in Russian universities."
According to data from the Russian Ministry of Education and Science, last year about 650 foreign teachers found employment in Russian universities and there is a possibility that this figure may be significantly increased this year.
One of the incentives planned is the provision of pension protection of foreign scientists after retirement.
In addition, the Ministry of Education and Science together with Russian universities plan to design a special work schedule for foreigners in Russian universities, taking into account the high workload of local university teachers, which may exceed 25 hours per week and which is significantly higher than that in Western universities. This will allow foreigners to teach fewer hours.
There are also plans to reduce income tax for foreign scientists working in Russia from the current 17% to 13%.
Demand has increased
According to an official spokesman of the Russian Ministry of Education and Science, the demand for work in Russia among foreign scientists has increased significantly in recent years, and one of the reasons for this is the improvement of the positions of Russian universities in international rankings.
This year the Moscow State University came close to the top 100 universities in the global QS World University Rankings, while the number of Russian universities in the top 400 of the Times Higher Education World University Rankings 2015-2016 doubled to four. (The ranking expanded from covering 400 universities to ranking 800 this year and nine other Russian universities appear in the top 800.)
Against this, the UNESCO Science Report, released last week, revealed that scientific output has stagnated in recent years and the average citation rate for articles (0.51) is just half the G20 average. The Russian Federation ranks 29th globally for the number of researchers, according to UNESCO.
To date, several leading Russian universities have already started trying to attract foreign scientists, one of them being the Russian Higher School of Economics, one of Russia's most prestigious universities in the field of economics and business.
Maria Yudkevich, vice-rector of the Higher School of Economics, said: "The university attracts different foreign specialists from post-doctoral fellows to world-renowned scientists for different periods of time. We are trying to provide not only a good salary, but also other decent conditions for working in Russia such as medical insurance, pension guarantees etc."
She added: "The current Russian legislation does not regulate the provision of particular benefits to foreign scientists working in national universities; however, there is a possibility that such a situation may change already in the coming years."
According to Vladimir Pligin, chairman of the Committee on Constitutional Legislation and State Construction of the Russian parliament (State Duma), as part of the state plans, the Russian parliament has already started designing a bill that will ease the process of the provision of visas to foreign scientists willing to work in Russian higher education institutions and will provide other benefits.
Since 2009 foreigners have been required to submit a whole pile of papers to gain permission to work in Russian universities. According to state comments, this ensured the protection of the Russian system of higher education from an influx of unqualified teachers. However, there is a possibility that the volume of paperwork with regard to foreigners may be significantly reduced by the end of the current year.
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The Pulitzer Center / November 20, 2015
Chill With Russia Brings Nuclear Insecurity
Эксперты опасаются, что достигнутые ранее успехи в вопросе российско-американского сотрудничество по ядерной безопасности могут сойти на нет.
MOSCOW - Nikolai Ponomarev-Stepnoi dedicated decades of his career to a U.S.-Russian effort to prevent nuclear proliferation.
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Today, the retired nuclear scientist is glumly watching it all fall apart.
"The communication has been cut off to not even at zero but negative," says the octogenarian, who was the first Russian scientist allowed to visit Three Mile Island after the 1979 reactor meltdown.
The former vice president of the independent Kurchatov Institute, one of the first Russian organizations to accept U.S. nuclear security assistance under the long-running Nunn-Lugar Cooperative Threat Reduction program, says nuclear security is too important to allow any spats to get in the way.
But that's just what has happened. Ever since Russia's annexation of Ukraine's Crimean Peninsula, he says the two sides have gone out of their way to spotlight disagreements to justify why they have cut off almost all nuclear security work.
"Both countries should cooperate regardless of anything happening in Ukraine or anywhere else because it is too dangerous in the world not to," says Ponomarev-Stepnoi.
In the first half of 2014, the Energy Department slowed down several joint projects with Russia's state-owned energy company Rosatom that would have sent Russian scientists to U.S. government nuclear laboratories and vice versa for technical discussions on atomic reactor safety and non-proliferation. Then in late 2014, Moscow said it wouldn't accept any more U.S. help in securing its large stockpiles of plutonium and weapons-grade uranium.
Congress too has made a 180-degree turn in this area. After more than two decades of funding joint U.S.-Russian nuclear security projects, lawmakers wrote into the fiscal 2016 defense policy bill a provision that would ban money for nuclear nonproliferation work in Russia. The Energy secretary would have the authority to waive that restriction. President Barack Obama vetoed the measure in late October without mentioning the issue, but the change shows just how far things have deteriorated.
The breakdown is part of a larger strategic fallout, which has the two countries on opposite sides of two armed conflicts in Europe and the Middle East.
Washington is pushing sanctions against Moscow and questions are being raised in both capitals about whether Russian President Vladimir Putin will pull out of a key Cold War-era arms control treaty.
The breakdown in nuclear security cooperation adds a new layer of risk and reignites fears of miscalculation and suspicion.
Senate Armed Services Chairman John McCain of Arizona says the Russians are clearly to blame. "When they cooperate, then I think we should consider the funding," he says. "When they're not cooperating, why should we waste the money on something we can't get done?"
Even former Indiana Republican Sen. Richard G. Lugar, who along with former Democratic Sen. Sam Nunn of Georgia shepherded congressional passage of the Cooperative Threat Reduction initiative in 1992, is pessimistic about the outlook for the nuclear security relationship with Moscow.
"I think this is going to be a very important part of any relationship that we have," he says. "It's going to require a different frame of mind on the part of the Russians, which obviously is not there presently."
Sleepwalking Toward Disaster
Interviews with nearly a dozen other senior Russian and American scientists, diplomats and retired defense officials reveal growing concerns that hard-won gains in post-Cold War nuclear nonproliferation are slowly being eroded. Russian and American officials still talk about the importance of working together to prevent nuclear terrorism, but there is no indication that either side intends to take steps to revive security cooperation and insulate it from other disputes.
Rose Gottemoeller, undersecretary of State for arms control and international security, says the administration is willing to resume stalled nuclear work, but Moscow has been dragging its feet.
"They've been good partners on nuclear security for the past 20 years so we continue to say, 'Look, we've got a good record here. We need to continue and work together, '" says Gottemoeller, who has worked on nonproliferation issues in the former Soviet Union since the end of the Cold War. "I have to say, though, that there is a real tentativeness on the Russian side right now about this cooperation. It's related, I think, to internal political noise in their system."
Republican Trent Franks of Arizona, a member of the House Armed Services Strategic Forces Subcommittee, adds: "It wasn't America that stepped back from it. It was really Russia that pulled away from us."
Many nuclear security advocates in Russia, however, don't accept that the fault lies mostly with Moscow, arguing that both governments have erred in taking for granted the nonproliferation gains made in the last quarter century.
Alexei Arbatov, a former member of the Russian parliament who worked on defense issues, warns the two countries are "sleepwalking into a comprehensive and unprecedented crisis of nuclear arms control."
Now chairman of the Carnegie Moscow Center's nonproliferation program, Arbatov says the lack of understanding between the United States and Russia of the other side's point of view has him losing sleep at night.
"I do not remember such a misunderstanding between Moscow and Washington since the early '60s," says Arbatov, who sits on the Russian Foreign Affairs Ministry's research council. "The situation changes, people change, generations change, and we may all once again find ourselves facing a new type of Cuban Missile Crisis."
After the collapse of the Soviet Union, Russia's inability to pay for basic things such as fences and guards' salaries at nuclear facilities led the United States to step in and help.
Starting in 1991, the Nunn-Lugar program spent billions of dollars in Russia, mostly through Defense Department-administered contracts that destroyed thousands of Soviet-era nuclear warheads and more than 1,000 long-range missiles, as well as dozens of submarines and bombers.
The money also went to help keep Russian nuclear scientists employed and to improve Russia's accounting practices for its millions of pounds of highly enriched uranium and plutonium. The program expired in 2013.
Can't Trust or Verify
Some U.S. officials and analysts privately say they are concerned that the longer the Russian economy deteriorates, the greater the temptation will be for the Kremlin to shortchange nuclear security projects, such as needed computer software updates at civilian sites housing nuclear materials. Moscow has said it can pay for all needed upgrades and site work on its own, but U.S. officials worry that they have no way of verifying that Russia has made good on its word.
"That is a continuing problem and why we have stressed to them that we need to continue to work together," says Gottemoeller.
A Western official in Moscow who insisted on anonymity acknowledges that Russia's economic situation today is not nearly as severe as the tailspin of the late 1980s and early 1990s. But the fears linger.
"What I think my greater concern would be … is even when the Russians make something their priority, these days there's so much corruption and so much inefficiency that they're really bad at it," the official says, noting that even major prestige projects such as Russia's space program have rockets blowing up on the launch pad or failing to reach orbit. "So my concern would be less the resources, more their ineptness."
Tom Marino, who sits on the House Foreign Affairs Subcommittee on Europe, Eurasia and Emerging Threats, says the United States would be foolish to count on Putin to protect Russia's nuclear materials from would-be traffickers.
"Russia has so much nuclear material missing, they just don't pay attention to it," says the Pennsylvania Republican, who is also the vice president of the NATO Parliamentary Assembly. "I don't know if they don't care or if it is just that they are so disorganized over there."
Comments like these infuriate Russians working in the nuclear security realm.
Anton Khlopkov, director of the independent Moscow-based Center for Energy and Security Studies think tank, says it is "humiliating" and counterproductive for the United States to question Russia's commitment to nuclear security.
"I see that this perception in the [United] States is very strong, that the level of nuclear security in Russia is still not appropriate," Khlopkov says. "I cannot accept that."
Khlopkov, a nonproliferation analyst and editor-in-chief of the journal Nuclear Club who has written policy briefs for the Stanley Foundation in Washington, says that if the United States is so concerned about deteriorating nuclear security standards in Russia, it should investigate how the billions of dollars in Nunn-Lugar activities were spent, since much of the work was handled by U.S. contractors and only concluded two years ago.
Anne Harrington, who heads up defense nuclear nonproliferation work for the Energy Department's nuclear weapons branch, says her office is ready to resume work with Russia under a 2013 agreement that would have each side co-finance nuclear security projects.
"We continue to engage at a technical level in areas of nonproliferation and threat reduction to the extent basically that the Russian government will allow us to," Harrington tells CQ. "That really is the constraining factor."
Even if Obama finds a way to smooth over serious differences with Putin over Ukraine and Syria to reinvigorate nuclear security, he would face considerable hurdles from staunch Republican critics.
House Armed Services member Michael R. Turner rejects the idea that more money will solve Russia's feared nuclear security problems, which were highlighted recently by news reports that Moldovan authorities have conducted several sting operations in recent years that turned up lethal quantities of radioactive material offered up for sale by smugglers with possible Russian connections.
"This is an issue of Russia having lax systems and needing to step up to the plate," the Ohio Republican says. "Russia has all of the resources that it needs to undertake its own control of its nuclear materials. They're in Syria using their military. They're in Ukraine. This is not an issue of lack of resources."
Democratic Sen. Edward J. Markey of Massachusetts is one of the few voices on Capitol Hill continuing to call for a revival of the nuclear security relationship with Russia.
"It's important for President Putin and President Obama to be talking at all times, especially about nuclear issues, because ultimately those kinds of weapons slipping into the hands of non-state players can wind up causing a catastrophic global situation," says the Foreign Relations member. "The job is not yet done; we have to ensure that the United States and Russia remain committed to securing any and all nuclear materials."
Washington Post / November 23, 2015
Remember those weird Siberian craters? Scientists say they may have an underwater version
В арктических морях происходят, возможно, те же процессы, которые привели к возникновению ямальских кратеров. К такому выводу пришли геологи из Арктического университета Норвегии и ВНИИОкеангеологии им. И.С.Грамберга, изучив континентальный шельф южной части Карского моря.
Статья «Methane release from pingo-like features across the South Kara Sea shelf, an area of thawing offshore permafrost» опубликована в журнале Journal of Geophysical Research: Earth Surface.
A recent scientific paper may have just cast new light on mysterious happenings on the Yamal Peninsula in Siberia, where the appearance of numerous large craters in the permafrost has been attributed, at least by some, to the venting of large pockets of methane gas, possibly in a dramatic or sudden way.
Now, say Pavel Serov and colleagues from the Centre for Arctic Gas Hydrate, Environment, and Climate at the Arctic University of Norway, possibly related structures appear to exist offshore as well, embedded within the shallow continental shelf of the South Kara Sea. The researchers published their results in August in the Journal of Geophysical Research: Earth Surface, but they have recently gained more attention, thanks in part to a report in Siberian Times.
In particular, the researchers say, they have detected and measured several offshore "pingo-like formations," large mounds rising from the seafloor. On land, pingos are gigantic icy mounds that form in some Arctic areas, with a huge wedge of ice protruding out of the ground, covered up by Earth so that it resembles a hill.
Subsea pingo-like formations have been studied as well - but in this case, the researchers say, they could involve much more than blocks of ice. Rather, the best explanation for at least one of them, the study suggests, appears to be a surge of methane from deep below the seafloor, creating a dome. They also suggest the formation could be unstable and possibly subject to a future blowout.
The deep methane source, they further suggest, is a so-called methane "hydrate," a frozen combination of methane and water that forms at high pressures and cold temperatures - i.e., deep beneath the ground or seafloor in the Arctic - but that can be destabilized by warming temperatures or by the Earth's heat from below.
"In this area, there are no other sources of such an extensive and such a focused amount of methane on the seafloor than gas hydrates," says Serov. "Plus we combined our observations with modeling results, and our modeling results show us that there could be gas hydrates inside the permafrost."
The idea that climate change could destabilize methane hydrates, which contain enormous amounts of methane, has been frequently evoked as a kind of doomsday climate scenario, since methane packs a much greater warming punch than carbon dioxide, at least over a short time scale. But the researchers say their results do not support such alarmism - they may have detected the destabilization and upward migration of hydrate in one area, but not anything systematic or large scale enough to suggest a climate worry.
"I think those pingos are zones of focused discharge, but the total input of methane coming from pingos is not so significant," says Serov.
The researchers report their results based on ocean measurements and marine core measurements surrounding several pingo-like formations in the region. Both were found in shallow waters of around 40 meters depth, bulging upward for a number of meters.
One very large group of pingo-like formations, the largest of which was up to 1,000 meters in diameter, did not have noteworthy concentrations of methane in the seafloor sediments at its top. However, a smaller one had very high concentrations of methane in the sediment, greater than 120,000 parts per million.
The researchers go on to reason that in the case of the latter pingo, it might very well be the result of warmer waters further destabilizing submerged permafrost, and tapping into a methane hydrate that has started to melt. The pressure from the gas could have risen up and created the mound.
The results are "provocative," says Carolyn Ruppel, who heads the gas hydrate program at the U.S. Geological Survey, in their implication that "one of these features may be storing and or expelling methane from deeper dissociating gas hydrates."
Ruppel agrees that in this particular area, there could indeed be gas hydrates in subsea permafrost. Such hydrates are distinct from the most common type of hydrate, found in deeper ocean regions where there is less concern of destabilization or of methane actually venting to the atmosphere, rather than being dissolved in ocean water.
"I definitely find this more plausible that there could be gas hydrate in this area, just based on what I know about permafrost hydrates, and their very different distribution in the world than deep marine hydrates," says Ruppel.
The complication, Ruppel adds, is that "there is no marker for methane that comes from dissociating gas hydrate." So the authors can't definitively prove that that is the actual source of the very high methane concentrations that they detected.
The worry that there could be a climatically significant methane "feedback" - in which warming destabilizes large amounts of methane that reach the atmosphere, driving more warming and more methane or carbon dioxide release - relies on a large number of assumptions and contingencies.
Nobody doubts that there are gigantic quantities of methane stored in gas hydrates around the world - one recent estimate is that hydrates contain between 1,600 and 1,800 gigatons, or billion metric tons, of carbon in the form of methane. That's more than enough to cause very rapid warming if these were to be somehow tapped into and reach the atmosphere.
But there are many things preventing that from happening. The most important is depth: There would have to be significant amounts of methane hydrates lying beneath relatively shallow waters. That's because for hydrates in deeper waters of about 100 meters or more, scientists think most or all of the methane released would be absorbed into the water column, rather than venting into the atmosphere in significant amounts.
Thus, the focus becomes hydrates located in permafrost on land or in permafrost beneath relatively shallow ocean waters. The latter are believed to be located in realms of so-called "relict permafrost" - areas that were once hard and frozen tundra, but that were flooded at the end of the last glacial maximum as ice sheets melted and sea levels rose. This process would have initiated a slow thawing of permafrost over thousands of years and in turn, destabilization of hydrates. Global warming, meanwhile, could now be adding oomph to that process.
The question then becomes how much subsea permafrost is still left and how much hydrate it contains. The new study calls this question "controversial" and does not make any quantitative claims about the matter.
Ruppel herself has published a recent study suggesting that only about 1 percent of all hydrate methane is located in permafrost, corresponding to 20 gigatons worth of carbon. Subsea permafrost would be a fraction of that. However, the study also noted that this is a "conservative" estimate.
That's why the new research, while it certainly does suggest one possible case of a hydrate dissociating from permafrost and creating a bulge on the seafloor, can't necessarily be used to raise alarms about the methane climate feedback.
"It's a difficult area to talk about because we have not much data conforming to or rejection the hypothesis," says Serov. The new study does assert, though, that in the South Kara Sea, there are reasons to think there is still relict permafrost, and that it is still in a process of thaw.
There's also a more immediate concern, Serov says - this is an area where there is much oil and gas development and the methane rich pingo-like formation could lead to a dangerous blowout. "It's a very big geohazard," he says. The paper notes that in the Pechora Sea, drilling into a pingo-like formation triggered an "emergency situation" for one vessel.
Finally, the analogy with the craters on land on the Yamal peninsula isn't a certain one, simply because there is still debate over the origins of those. But there are definitely suggestions that they involve pingos and, possibly, methane releases.
"I think you've heard about the Yamal craters," says Serov. "It might be more or less the same process, but going on onshore."
The takeaway, then, is that we certainly have some evidence of odd happenings in permafrost regions in Siberia - some of which may involve methane. It's not time to freak out about this. But the developments do underscore that when it comes to the rapidly changing Arctic, changes to permafrost could be one of the most important alterations to the Earth's system, brought on by our own actions.
Washingtonpost.com © 1996-2015 The Washington Post.
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SciCasts / Nov 23, 2015
Scientists Investigate Mechanisms of Self-Organization in Living Cells
Российские биологи выяснили, каким образом двухметровые нити ДНК сворачиваются в трехмерные структуры, чтобы уместиться в ядро, диаметр которого не превышает 0,01 мм. Оказывается, молекула ДНК наматывается на специальные белки (гистоны), а затем сворачивается так, что некоторые участки нити ДНК находятся близко друг к другу и взаимодействуют.
Статья «Active chromatin and transcription play a key role in chromosome partitioning into topologically associating domains» опубликована в журнале Genome Research.
Moskva, Russia (Scicasts) - Chromosome is a structure inside the cell nucleus that carries a large part of the genetic information and is responsible for its storage, transfer and implementation.
Chromosome is formed from a very long DNA molecule - a double chain of a plurality of genes. Given that the diameter of the cell nucleus is usually around hundredth of a millimetre or even less, while the total length of DNA constituting human genome is about two meters, it is clear that DNA must be packaged very tightly.
DNA-protein fibril forms visible mitotic chromosomes only during cell division. But in between the divisions DNA is not just floating in the cell nucleus: in order not to get tangled or broken, it is wound on special proteins - histones - as thin and long thread on a spool, and then is folded in such a way that some sections of DNA strand are close to each other and can interact to form compact aggregates. These compact regions are called topologically associated domains, or TADs. Regions located between the TADs ("inter-TADs"), in contrast, are characterized by a low level of interaction.
A group of Russian researchers, led by Sergei Razin (Head of the Department of Molecular Biology, Faculty of Biology, Lomonosov Moscow State University, corresponding member of Russian Academy of Sciences), studied how filamentous DNA-protein fibrils of chromatin are stacked in three-dimensional structures - TADs and inter-TADs. The results of the research have been published in Genome Research (impact factor - 13.852), and also have been mentioned in the Research Highlights of the current issue of Nature Review Genetics.
"Previously, several authors have demonstrated that the genomes of mammals and fruit flies are organized into compact topologically associated domains - TADs separated by some border areas," said the head of the group Sergey Razin. "Yet the nature of these border areas has remained unclear. Most authors believe that the very existence of these boundaries between compact domains is determined by the presence of special "dividing" genomic elements - insulators, but no one could explain the mechanism of their action. We have demonstrated that TADs are separated by active regions of the genome containing genes that work in all types of cells (so-called "housekeeping" genes). Features of chromatin in working genes are sufficient to explain why such a chromatin simply can't be stowed in compact TADs."
Russian scientists were able to show how the DNA-protein fibril itself fits into the three-dimensional structure. This is a vivid demonstration of the mechanisms of self-organization in living cells. It is this conceptual component of the work that awakened an echo in hearts of researchers all over the world.
"We can say without exaggeration that now the entirely Russian work has appeared at the peak of the world's research. In Russia we have no such "breakthrough works" in genomics for many years. This became possible also due to the interdisciplinary nature of the group of authors (biology, bioinformatics, and physics). Computer simulation that was fundamentally important to confirm the findings has become possible due to the presence of supercomputer "Lomonosov" at MSU," says Sergey Razin.
Findings made by Russian researchers may provide the basis for important practical developments: scientists have good reason to believe that TADs are also regulatory domains in which enhancers (small sections of DNA that increase the expression of genes) can activate a variety of tissue-specific genes. Thus, the association of TADs as a result of chromosomal rearrangements or their separation can lead to changes in the spectrum of genes that are activated by any given enhancer, and this may be the cause of various diseases.
According to Sergei Razin, the knowledge of the mechanisms of formation of these diseases will allow to develop science-based strategies for their treatment: currently, many pharmaceutical companies are already actively engaged in the development of so-called "epigenetic drugs" that can, for example, make the cancer cells lose the ability to multiply uncontrollably.
However, this work is currently being done largely at random, by analyzing the effect that various compounds have on the work of epigenetic mechanisms. In order to make searching for such drugs more meaningful, one must understand how epigenetic control of gene transcription works. It is currently clear that these systems affect the way the packaging of DNA inside chromatin.
Thus, the disclosure of principles of three-dimensional organization of chromatin fibrils is a prerequisite for understanding the mechanisms of epigenetic systems and, consequently, developing strategies of targeted intervention into the operation of these systems.
Copyright © 2015 Scicasts Ltd.
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Horsetalk / 24 November 2015
Horses in eastern Siberia adapted to icy cold in only 100 generations
Генетики из Европы, США и России расшифровали геном лошади, жившей на Таймыре около 5000 лет назад, и выяснили, как ее родственникам, современным якутским лошадям, удалось приспособиться к жизни в условиях сильнейших морозов. Оказалось, что это заняло у них всего лишь 800 лет, т.е. в случае острой необходимости адаптация и эволюция могут проходить очень быстро.
Статья «Tracking the origins of Yakutian horses and the genetic basis for their fast adaptation to subarctic environments» опубликована в журнале PNAS.
Yakutian horses adapted to the extreme cold of eastern Siberia in less than 800 years, according to researchers.
The study team said the change happened almost overnight in evolutionary terms, covering only 100 or so generations. The process involved changes in the expression of a raft of genes, including some also selected in human Siberian groups and the extinct woolly mammoth.
The researchers, in a new scientific study, compared the complete genomes of nine living and two ancient Yakutian horses from Far-East Siberia with a large genome panel of 27 domesticated horses.
The analysis shows that the current population of Yakutian horses was founded after the migration of the Yakut people into the region in the 13-15th century AD. Yakutian horses thus developed their striking adaptations to the extremely cold climate of the region in less than eight centuries.
This represents one of the fastest examples of evolutionary adaptation yet seen within mammals.
The international team of researchers, whose findings have been published in the early edition of PNAS (Proceedings of the National Academy of Sciences of the USA), said horses have been essential to the survival and development of the Yakut people, who migrated into the Far-East Siberia, probably from Mongolia.
There, Yakut people developed an economy almost entirely based on horses. Horses were crucial for communication and keeping the population in contact within a territory slightly larger than Argentina, and with 40% of its surface area situated north of the Arctic Circle.
Horse meat and hides have also been revealed as crucial for surviving extremely cold winters, with temperatures occasionally dropping below -70 degrees Celsius.
Horses have been present in Yakutia for a long time, as 30,000 year-old Late Pleistocene fossils from the region show. Yet, the study team, led by the University of Copenhagen's Dr Ludovic Orlando, showed that ancient horses of this region were not the ancestors of the present-day Yakutian horses.
The genome sequence obtained from the remains of a 5200 year-old horse from Yakutia appears within the diversity of a now-extinct population of wild horses that the team discovered last year in Late Pleistocene fossils from the Taymir peninsula, in Central Siberia.
This new finding extends by thousands of kilometres eastwards the geographical range of this divergent horse population, which became separated from the lineage leading to modern horses some 150,000 years ago. It also extends its presence up to 5200 years ago - a time when woolly mammoths also became extinct.
"This population did not appear on any radar until we sequenced the genomes of some of its members," said Dr Orlando, who is with the Centre for GeoGenetics at the Natural History Museum of Denmark, which is part of the University of Copenhagen.
"With 150,000 years of divergence with the lineage leading to modern horses, this makes the roots of this population as deep as the origins of our human species."
Interestingly, the new genome analyses show that the horses Yakut people now ride, and probably rode throughout history, as shown by the genome of a horse that lived about 200 years ago, are not related with this now-extinct horse lineage, but rather with the domesticated horses from Mongolia.
"We know now that the extinct population of wild horses survived in Yakutia until 5200 years ago.
"Thus, it extended from the Taymir peninsula to Yakutia, and probably all across the entire Holarctic region. In Yakutia, it may have become extinct prior to the arrival of Yakut people and their horses. Judging from the genome data, modern Yakutian horses are no closer to the extinct population than is any other domesticated horse."
The new genome analyses show that the founders of the modern Yakutian horse population probably entered the region with Yakut horse-riders in the 13-15th Century AD.
"This is truly amazing as it implies that all traits now seen in Yakutian horses are the product of very fast adaptive processes, taking place in about 800 years.
"This represents about a hundred generations for horses. That shows how fast evolution can go when selective pressures for survival are as strong as in the extreme environment of Yakutia."
The team set out to identify the genes underlying such adaptations. Strikingly, they found that a large fraction of the selection signatures were not located within the coding region of genes, but within their upstream regulatory regions. It thus suggests that the adaptation of Yakutian horses to their environment took place through a massive reprogramming of gene expression.
"The founder group of the current population was quite reduced in size," he said.
"The genetic variation standing within gene bodies was, thus, probably limited in comparison to that present within regulatory regions. These regulatory variants probably offered as many possibilities to rapidly modify horse traits in a way that was compatible with their survival."
Focusing on the genes and their regulatory regions showing evidence of selection, the team identified key biological functions involved in the adaptive process. These concern physical changes, hormonal responses involved in heat regulation and even the production of anti-freezing compounds.
The list of selective signatures also include genes, such as TGM3, which is involved in hair development and might be responsible for the extremely hairy winter coat of Yakutian horses.
Fellow researcher Dr Pablo Librado, who is also with the university, said: "In addition to unveiling their evolutionary origins, our approach helped narrow down the genetic basis of adaptations that are unique to Yakutian horses. In one word, their genetic makeup.
"We also found genes that were reported to have undergone selection in other Arctic populations, such as indigenous Siberian humans, and even the woolly mammoth. It provides a compelling example of evolutionary convergence, where unrelated groups exposed to similar environments end up independently developing similar adaptations."
Colleague Dr Clio Der Sarkissian, who also took part in the study, said the work showed the power of ancient DNA. "We would have never been able to discover the existence of the now extinct ancient population of horses by analyzing the genome of modern horses.
"With ancient genomes, we can now understand the dynamics of past populations at unprecedented levels and track, through space and time, how these became adapted to changing environments.
"Applied to pre-industrial museum specimens, our approach can therefore help following how extant populations have been affected by ongoing climate changes and recent human activities. This can help develop tailor-made conservation programs, which will be ultimately essential for preserving endangered populations."
The study group has already implemented such approaches for preserving the Przewalski's horse, which represents the last truly wild horse living in the planet.
© Copyright Horsetalk: World equestrian news and information 2015. All rights reserved.
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EurekAlert / 24-Nov-2015
Physicists explain the unusual behavior of strongly disordered superconductors
Using a theory they developed previously, the scientists have linked superconducting carrier density with the quantum properties of a substance.
Российские физики из МФТИ Михаил Фейгельман и Лев Иоффе объяснили необычный эффект в так называемых сверхпроводниках с псевдощелью. «Щель» - характерный зазор на диаграмме с распределением электронов по энергиям, возникающий одновременно со сверхпроводимостью при охлаждении сверхпроводника до критической температуры. Если зазор уже появился, а сверхпроводимость - еще нет, употребляется термин «псевдощель». Свойства такого сверхпроводника во многом отличаются от обычных.
Несколько лет назад ученые предложили теорию, в которую вписываются сверхпроводники с псевдощелью, а теперь рассчитали для них зависимость плотности сверхпроводящего тока от ширины псевдощели.
Physicists Mikhail Feigel'man (the head of MIPT's theoretical nanophysics laboratory) and Lev Ioffe have explained the unusual effect in a number of promising superconductor materials. Using a theory they developed previously, the scientists have linked superconducting carrier density with the quantum properties of a substance.
In the paper published by the scientists in Physical Review B: Condensed Matter And Materials Physics, they discuss so-called pseudogapped superconductors. The term "gap" appears in the quantum theory of superconductivity and is a definition for the characteristic gap in an electron energy distribution diagram, the energy spectrum. A distinction is made between superconductors with a "conventional" gap and special superconductors, which, even in their normal state, demonstrate something similar to a gap - it is called a pseudogap.
Electron pairs and superconductivity
In order to understand what a "gap" is, we need to look briefly at the theory behind the term. At present, there is no complete model which is able to explain the phenomenon of superconductivity in full detail (and which would enable us, for example, to synthesize a superconductor capable of working at room temperature). However, one successful model that is most often used today is the BCS theory, which was developed by John Bardeen, Leon Cooper, and John Robert Schrieffer. In BCS theory, a key role is played by Cooper pairs - two electrons bound together with opposite spins. These pairs are characterized, on the one hand, by a very weak bond between the particles (which is purely of a quantum nature - in classical theory electrons have the same charge and should repel one another), and on the other hand because they do not interact with the crystal lattice and therefore move freely within a substance and do not lose energy in collisions. If a metal is cooled to a temperature where the thermal motion of particles does not prevent the formation of Cooper pairs, these pairs can be made to move without loss of energy and thus cause the whole specimen to reach its superconducting state.
The formation of Cooper pairs alters not only the electrical properties of a substance as a whole, but also electron energy distribution, the energy spectrum. The coupling of the pairs results in a characteristic gap, or pseudogap depending on the circumstances. If the substance is a superconductor, and after cooling to critical temperature superconductivity was reached at the same time as the formation of the Cooper pairs, it is called a gap. However, if this occurs in the electron spectrum diagram after cooling, but superconductivity has not yet been reached, the term pseudogap is used (meaning it is not a "true" gap, and its formation is not linked to the onset of superconductivity). If this substance is cooled further, it will become a superconductor and the gap in its spectrum will increase - its value will include both the pseudogap and the superconducting gap itself. The properties of these superconductors are considerably different to those of conventional superconductors.
Superconductors with a normal gap fit in well with the BCS theory, which explicitly links Cooper pairs with the formation of a gap in an energy distribution diagram. According to this theory, superconducting current density is directly proportional to the magnitude of the superconducting gap: сs ~ Δ, the more Cooper pairs formed per unit volume, the larger the gap in the energy spectrum, i.e. the size of the gap.
Superconductors with a pseudogap do not fit in with the BCS theory, but they can be described using the theory proposed earlier by Mikhail Feigel'man and Lev Ioffe and their colleagues. In their new paper, the scientists used their theory to calculate the dependence of superconducting current density on pseudogap width for a pseudogapped superconductor.
The key is in the disorder
Studying the structure of pseudogapped superconductors at microscopic level showed that these materials are strongly disordered. This means that their atoms are not arranged in a perfect crystal lattice, or the structure of this lattice is strongly impaired. Examples of pseudogapped superconductors given by the authors of the new paper are thin films of titanium nitride (in which the crystal lattice is impaired in many places) and indium oxide (which can be completely amorphous, like glass).
Disorder plays a key role because the transition to a superconducting state does not happen at the same time as the formation of Cooper pairs. The electrons that are bound to each other in these materials appear before electrical resistance disappears because the numerous variations in the substance's microscopic structure from the ideal order can impede a Cooper pair, which in ordered crystals would move freely without interference.
It should be emphasized that Cooper pairs in a pseudogapped superconductor cannot be described as motionless. As a result of quantum effects, their behaviour is slightly more complex: obeying the uncertainty principle, they do not freeze motionless in one place, but "spread out" over a rather large (dozens of interatomic distances), but finite region. If they could move, this region would cover the entire substance: the illustration below will help to better understand the process.
Deducing electrical parameters of pseudogapped superconductors from quantum properties is important both from a fundamental point of view (scientists are beginning to have a better general understanding of superconductors), and a practical point of view. The researchers note that using indium oxide, a typical pseudogapped superconductor, it has already been possible to create a superconducting quantum device that can be used as a prototype component for a quantum computer.
Having considered the movement of Cooper pairs in a substance with varying degrees of disorder, the scientists deduced the theoretical dependence of the density of Cooper pairs сs in the substance on pseudogap width. This is an important characteristic, as it is inversely proportional to the inductance of the film (the materials described are obtained in film form) in the superconducting state. Films such as this with high inductance and zero resistance are needed to produce qubits, the fundamental units of quantum computing devices.
In conventional superconductors, the dependence of the density of Cooper pairs on pseudogap width is linear (сs ~ Δ), however, in the test substances the dependence is squared (сs ~ Δ2). This fact is easy to verify experimentally in a more detailed study, and, if that happens, the theory developed previously by the authors will receive further confirmation.
Copyright © 2015 by the American Association for the Advancement of Science (AAAS).
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US News and World Report / Nov. 28, 2015
Rich in energy and with vast forests, Russia pays little attention to climate change
- By Katherine Jacobsen, Associated Press
Российская национальная метеорологическая служба утверждает, что Россия расположена в той части света, где потепление климата происходит быстрее всего. При этом не предпринимается практически никаких мер для того, чтобы ограничить выброс в атмосферу парникового газа, по объемам которого Россия занимает 4-е место в мире.
MOSCOW (AP) - When forest fires roared through Siberia this summer, so vast that the smoke blocked vast Lake Baikal from satellite view, Russian officials blamed the blazes on arsonists and disorganized fire crews. Environmentalists say there was another culprit: global warming.
As temperatures rise worldwide, areas such as Siberia are suffering increasingly long dry spells. Russia's national weather agency says the country is the fastest-warming part of the world.
But Russia has taken little action to reduce its own emissions of the greenhouse gases believed to be behind the warming and at next week's international climate conference in Paris it aims to push a proposal that would allow its emissions to increase.
To Vladimir Chuprov of Greenpeace Russia, the country's leadership is obtuse and in denial.
"Of course the forest won't burn if it's not set on fire, but the unusually dry environment and high temperatures - that's global warming," he said. "The fact that the fires burned for so long, that's because the government can't adapt to the new demands of a warming climate."
The issue is largely absent from public discussion and officials appear to give it only lip service, when they're not sardonically dismissing it.
In 2003 at the World Climate Change Conference, President Vladimir Putin quipped that "Russia is a northern country. It's not scary if it's two to three degrees warmer. Maybe it would even be a good thing. We'd have to spend less money on fur coats and warmer things."
Leading up to the Paris conference, which seeks to implement the most ambitious emissions cuts ever, Russia presented a paradoxical pledge by promising to reduce its greenhouse gas output over the next 15 years by 25 to 30 percent from what it was in 1990. However, 1990 saw a spike in industrial output before the Soviet industrial complex collapsed during the decade, causing a steep drop in emissions. So Russia's pledge means it could actually increase emission levels by about 40 percent from current levels by 2030.
The 1990 emissions levels were the baseline for cuts in the Kyoto Treaty of 1997; that baseline is still used by many countries, including those of the European Union.
By volume, Russia is the world's fourth-largest greenhouse gas emitter after China, the United States and India, releasing more than 2 gigatons of greenhouse gases per year. But based on emissions per unit of gross domestic product, Russia is one of the most carbon intensive countries in the world, according to Shift Project Data Portal, an aggregator of climate change statistics; China, India and the U.S. aren't even in the top 20.
"One doesn't get the sense from Russia that climate change is a big problem," said Bill Hare, the head of the Climate Analytics research group. "There is a clear lack of political will in Russia to address climate change, which will be much to their detriment in the coming years."
Russia's chief climate negotiator, Oleg Shamanov, canceled an interview requested by The Associated Press.
Russia may be paying little attention to the issue because of the influence of the state-controlled oil and gas companies and the metallurgical industries that account for some 90 percent of the country's export revenue.
"Because of the oil and gas lobby, climate and environmental issues are more often than not ignored by the government," said Chuprov.
At the Copenhagen climate talks in 2009, Russia also agreed to transition 4.5 percent of its power sources to renewable energy, with national funding for renewable energy projects to start in 2014. This year, lawmakers postponed the program until 2024. Currently, 0.2 percent of all Russian energy comes from renewable sources, excluding hydropower, says Greenpeace's Chuprov.
In a country where even recycling is a little-understood concept, there is little support and few incentives from the national government for Russian companies to switch over to green energy.
"To get rid of the climate change, or at least stop it ... they never find the money," said Yevgenia Chirikova, an environmental activist who has left the country due to pressure from the government related to her work.
One natural antidote for Russia's emissions could be its carbon-absorbing boreal forests, which absorb approximately 500 million tons of emissions per year. Russian climate change negotiators have been pushing to include the forests in carbon emissions calculations, but critics say that including the forests' carbon-offset would mean that Russia would reduce emissions only by 6-11 percent by 2030. And scientists at the Russian Academy of Science warn that increased greenhouse gas emissions could negate the carbon absorbing effects of the boreal forests by 2040.
Copyright 2015 © U.S. News & World Report LP.
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