Октябрь 2015 г. |
Российская наука и мир (по материалам зарубежной электронной прессы) |
EurekAler / 5-Oct-2015
Magnetic contraption tricks migrating songbirds into changing direction
|
Российские и британские орнитологи, несколько лет назад открывшие в мозге перелетных птиц "магнитный компас" на основе белков-криптохромов, доказали, что к "компасу" прилагается еще и "магнитная карта", которая помогает птицам находить дорогу на зимовье и обратно из любой точки.
Статья "Eurasian reed warblers compensate for virtual magnetic displacement" опубликована в журнале Current Biology.
When researchers captured Eurasian reed warblers along the Russian coast during their spring migrations and flew them 1,000 kilometers east to Zvenigorod, the birds weren't fazed; they simply re-oriented themselves toward their original destination. Now, the researchers who first demonstrated the birds' navigational skill in the Cell Press journal Current Biology several years ago are back with new evidence that reed warblers rely on a geomagnetic map to point them in the right direction.
In fact, the researchers show in Current Biology on October 5 that the birds will respond as though they've been sent to Zvenigorod when they are captured and exposed to a geomagnetic field that matches that location.
"The most amazing part of our finding is that the same birds sitting on the same dune of Courish Spit on the Baltic coast shifted their orientation from their normal migratory direction - northeast - to the northwest after we slightly turned current control knobs on our power supplies," says Dmitry Kishkinev of Queen's University Belfast. "All the other sensory cues remained the same for the birds."
To test the role of magnetic fields, Kishkinev, together with Nikita Chernetsov at the Biological Station Rybachy and their colleagues, had a special magnetic coil system built that allowed them to create a homogeneous magnetic field out on their coastal field site, where it's very easy to catch migratory reed warblers. The system allowed them to manipulate the magnetic field without obscuring the birds' ability to pick up on other cues, including the sun, stars, landmarks, and scents.
The birds were housed inside the magnetic coil system for several days. In that time, they were virtually displaced with a change in magnetic field only once to avoid confusion. The data show that this change in the magnetic parameters led the birds to re-orient toward their breeding destinations just as they would if they'd been physically displaced.
The researchers now suspect that reed warblers track changes in the geomagnetic parameters as they travel during their first fall migration - for example, from the Baltic down to West Africa - to establish certain "rules of thumb." Those rules then guide the birds on future migrations and make it possible for them to re-orient themselves if they find they've gotten off track.
The study provides some of the strongest evidence yet that at least some birds rely on a geomagnetic map for long-distance navigation, as spiny lobsters and sea turtles also do. Although the idea of magnetic navigation in birds was first proposed back in the 19th century, it has been a challenge to prove, the researchers say.
Further work is needed to understand how birds sense magnetic fields and which portions of the magnetic field are most important to them. The researchers are also curious to know whether reed warblers rely on their sense of smell, as some seabirds and homing pigeons do.
Copyright © 2015 by the American Association for the Advancement of Science (AAAS).
* * *
Nanotechnology News / October 6th, 2015
Superconductivity trained to promote magnetization Russian scientist and her colleagues discovered the superconductivity effect, which will help to create future supercomputers.
|
Физики из НИИ ядерной физики им. Д.В.Скобельцына и их британские и швейцарские коллеги выяснили, что сверхпроводимость, почти несовместимая с магнитным полем, при определенных условиях может способствовать его распространению. Ученые смогли превратить тонкую золотую пластинку в подобие магнита, используя ниобиевый сверхпроводник и ферромагнетик.
Статья "Remotely induced magnetism in a normal metal using a superconducting spin-valve" опубликована в журнале Nature Physics.
The research team, which included Natalya Pugach from the Skobeltsyn Institute of Nuclear Physics, studied the interactions between superconductivity and magnetization in order to understand how to control electron spins (electron magnetic moments) and to create the new generation of electronics.
In traditional microelectronics information is coded via the electric charges. In spin electronics - or spintronics - information is coded via the electron spin, which could be directed along or against particular axis.
"Superconducting spintronic devices will demand far less energy and emit less heat. It means, that this technology will allow to create much more economical and stable computing machines and supercomputers", - Natalya Pugach explains.
The main obstacle to the development of these devices lies in the fact, that the spins of the electron and of other charged particles are very difficult to control. The results of this new research show, that superconductors may be useful in the process of spin transportation, and ferromagnetics may be used to control spins.
Superconducting state is very responsive sensitive to magnetic fields: strong magnetic fields destroy it, but and superconductors expel the magnetic field completely. It is almost impossible to make ordinary superconductors and magnetic materials interact with each other due to their opposite magnetic ordering direction of magnetization: in magnetic layers storages the magnetic field tends to arrange spins in one direction, and the Cooper pair (BCS pair) in ordinary superconductors haves opposite spins.
"My colleagues experimented with devices called superconducting spin-valves. They look like a "sandwich", made of nanolayers of ferromagnetic material, superconductor and other metals. By changing the direction of magnetization it is possible to control the current in superconductor. The thickness of layers is crucial, because in case of the "thick" superconductor it is impossible to see any interesting effects", - Natalya Pugach explains.
During the experiments scientists bombarded the experimental samples with muons (particles that resemble electrons, but are 200 times heavier) and analyzed their dissipation scattering. This method gave the researchers the possibility to understand, how the magnetization proceeds in different layers of the sample.
The spin-valve consisted of two ferromagnetic cobalt layers, one superconductive niobium layer with thickness of approximately 150 atoms and a layer of gold. In the experiment researchers discovered an unexpected effect: when magnetization directions in two ferromagnetic layers were not parallel, the interaction between these layers and superconductive layer produced induced magnetization in the gold layer, "overjumping" the superconductor. When scientists changed the magnetization directions in two layers, making them parallel, this effect almost disappeared: field intensity experienced twentyfold decrease.
"This effect was unexpected. We were very surprised to discover it. Previously we tried to explain the results with another magnetization distribution pattern, that was predicted before, but in vain. We have some hypotheses, but we still do not have any complete explanation. But nevertheless this effect allows us to use the new method of manipulations with spins", - Natalya Pugach says.
It is quite possible, that the finding will allow development to develop conceptually new spintronic elements. According to Natalya Pugach, superconductive spintronics technologies may help to build supercomputers and powerful servers, whose energy consumption and heat emission create much more problems than in case of ordinary desktop computers.
"Development of computer technologies was based on semiconductors. They are good for personal computers, but when you use these semiconductors to build supercomputers, they produce heat and noise, demand powerful cooling systems. Spintronics allows to solve all these problems", - Natalya Pugach concludes.
© Copyright 1999-2015 7th Wave, Inc. All Rights Reserved.
* * *
EurekAlert / 7-Oct-2015
Ionic and covalent drug delivery
|
Ученые из Института органической химии им. Н.Д.Зелинского изучили три способа растворения активных фармацевтических ингредиентов в ионных жидкостях: в качестве аниона или катиона (ионная связь), с помощью ковалентной связи или с одновременным использованием этих двух типов связей. Ионные жидкости не только заметно улучшают растворимость, но и позволяют производить жидкие препараты "двойного действия", т.е. содержащие сразу два активных ингредиента.
Статья "Cytotoxic activity of salicylic acid-containing drug models with ionic and covalent binding" опубликована в журнале ACS Medicinal Chemistry Letters.
The human organism is composed of numerous types of molecules, both simple and complex, and all fundamental processes in a living body occur in water solutions. Therefore, for a drug to work, it must dissolve in body liquids, which are primarily water. Polymorphism of solid substances, a well-known problem of drug delivery, is the ability of solid drugs to form several different crystal structures (polymorphs). Polymorphs may differ in properties like biological activity, and in addition, their formation is difficult to control.
The problem of crystal polymorphs can be solved by liquid substances or solutions, as their medical usage is more predictable and reliable. Thus, many researchers investigate possibilities of solubilization of existing active pharmaceutical ingredients. It was previously identified that transformation of a poorly soluble substance into a salt may substantially increase solubility.
Group of scientists led by Professor Ananikov proved that Ionic liquids are excellent candidates to connect organic molecules to salt structures. Currently, there are three techniques to introduce active pharmaceutical ingredients into the ionic liquids: i) as an anion or a cation (ionic bond); ii) via a covalent linkage (covalent bond); and iii) using both ionic and covalent binding.
The proposed drug development platform has the following valuable advantages:
1. Tunable hydrophobicity/lipophilicity for adjusting the ability to penetrate through cell membranes and other biological barriers.
2. Ionic core, which implies the ability to modulate the strength of ionic binding. Ionic liquids are highly tunable and can be readily optimized to connect with a variety of pharmaceutical ingredients.
3. Variable linker for regulating the distance between the ionic core and active pharmaceutical ingredient. This linker may contain a specific site of enzymatic cleavage for target release of active pharmaceutical ingredient in the place of action.
The researchers used salicylic acid (a well-known anti-inflammatory compound) as a model drug and incorporated the molecule of salicylic acid into ionic liquids. The scientists studied solubility and biological activity of salicylic acid-containing ionic liquids towards human fibroblasts and colorectal adenocarcinoma cells. Indeed, salicylic acid retained its activity in the ionic liquid form. At the same time, it demonstrated dramatically higher water solubility in the complex with ionic liquid, as compared to the pure salicylic acid.
The study points out the important advances of API-IL concept in drug development and pharmaceutics (API - active pharmaceutical ingredient; IL - ionic liquid). Variability and ability to access a diversity of molecular combinations should be taken into account. Next, highly promising application is the production of "dual-action" drugs bearing two different active pharmaceutical ingredients with ionic and covalent binding. This approach may allow complex treatment targeting different potential causes of the pathology.
Copyright © 2015 by the American Association for the Advancement of Science (AAAS).
* * *
ScienceInsider / 8 October 2015
U.S.-Russia tensions put a chill on ice disaster research effort
|
Под угрозой срыва из-за санкций оказался совместный исследовательский проект Университета Аляски (Фэрбенкс) и Северо-Восточного федерального университета (Якутск) по изучению ледяных заторов на реках и их последствий в виде масштабных наводнений, от которых страдают и Аляска, и Якутия.
As tensions between the United States and Russia remain high, funding for a program to share knowledge between the two nations on disasters known as ice jam floods has been thrown into disarray by U.S. sanctions. Now, scientists are going hat in hand to collect funds to save the effort.
"Sometimes political decisions [trump] scientific cooperation," says Tuyara Gavrileva, a social scientist with the North-Eastern Federal University in Yakutsk, Russia. "The law is the law."
Ice jam floods generally occur in the Arctic in the spring, when rapid warming can break up river ice, creating obstructions and flooding of nearby settlements. The new joint research project, run by the University of Alaska, Fairbanks (UAF), and Gavrileva's university, focuses on two towns that both experienced catastrophic floods in May 2013: Galena, Alaska, and Edeytsy, Russia. Most public infrastructure in Edeytsy, in the Sakha republic, was destroyed in the floods, and some 1300 people were displaced. In Galena, floods drove 60% of residents from their homes.
This past March, John Eichelberger, a UAF geologist, submitted a grant proposal for the project to the U.S.-Russia Peer-to-Peer Dialogue Program, run by the U.S. embassy in Moscow. The peer program supports joint projects related to environmental, civic, health, or youth issues. In June, Eichelberger received a preliminary notice of approval for the grant, which included support for U.S. experts to travel to Sakha, and for Russians to later travel to Alaska. That's particularly crucial for Russian scientists, Gavrileva says. "My university does not have sufficient funds to finance a trip of several specialists [to] the United States," she says.
But in late August, embassy officials told Eichelberger in an email that, essentially, he couldn't get U.S. government funds to support the Russian scientists' travel. Eichelberger said he was "shocked" to receive the message. He resubmitted his grant, omiting support for the Russians to visit the United States. The revised grant was accepted late last month, so now the program is back on, but Eichelberger is fundraising to make up roughly $30,000. He says he has raised half that amount so far by tapping other funders interested in climate change.
"We have a lot to learn from the Russians on the Arctic flood issue," Eichelberger says, noting that Russian scientists have since the 1990s been experimenting with various mitigation efforts, such as cutting ice in the spring, or putting homes on stilts. "It's wonderful working with the Russians."
Although he says the effect of politics on international science is has "disheartened" him, he sees the episode with rose-tinted glasses. "The State Department in general and U.S. embassy in Moscow in particular are making the best of a bad situation," he says. "They could have canceled the Peer-to-Peer program entirely."
Peer-to-Peer is only one of several joint programs that have been disrupted by political strife between the United States and Russia. Last year, after Russia intervened in Ukraine, the United States suspended a presidential initiative called the U.S.-Russia Bilateral Presidential Commission, meant to foster partnership between government officials on areas including energy, environment, and health. The suspension of that program led to the cancelation of a planned international workshop on natural disasters in the Arctic that Eichelberger had helped organize.
© 2015 American Association for the Advancement of Science. All Rights Reserved.
* * *
Nature / 20 October 2015
Russian secret service to vet research papers Moscow biology department among the first to require that all manuscripts comply with law on state secrets.
|
Институт физико-химической биологии имени А.Н.Белозерского при МГУ стал одним из первых научных учреждений, от которых потребовали, чтобы все публикуемые труды ученых соответствовали закону о государственной тайне. Отсылать тексты работ в журналы и оргкомитеты научных конференций можно лишь с разрешения ФСБ.
A biology institute at Russia's largest and most prestigious university has instructed its scientists to get all research manuscripts approved by the security service before submitting them to conferences or journals.
The instructions, which come in response to an amended law on state secrets, appear in minutes from a meeting held on 5 October at the A. N. Belozersky Institute of Physico-Chemical Biology at Lomonosov Moscow State University (MSU).
The Russian government says that the amendment is not designed to restrict the publication of basic, non-military research. But scientists say that they believe institutes across the country are issuing similar orders.
"This is a return to Soviet times when in order to send a paper to an international journal, we had to get a permission specifying that the result is not new and important and hence may be published abroad," says Mikhail Gelfand, a bioinformatician at MSU.
In 1993, the government passed a law obliging scientists in Russia to get permission from the Federal Security Service (FSB) before publishing results that might have military or industrial significance. This mainly covered work that related to building weapons, including nuclear, biological and chemical ones.
However, in May, President Vladimir Putin used a decree to expand the scope of the law to include any science that can be used to develop vaguely defined "new products". The amendment was part of a broader crackdown that included declaring the deaths and wounding of soldiers during peacetime a secret; this was prompted by accusations that Russian soldiers are involved in conflict in Ukraine.
Since then, rumours have emerged that Russian universities and institutes are demanding that manuscripts be approved before submission to comply with the amendment. The minutes from the Belozersky Institute meeting confirm this. "Be reminded that current legislation obliges scientists to get approval prior to publication of any article and conference talk or poster," they say. They note that the rules apply to any publication or conference, foreign or national, and to all staff "without exception".
Scientists will need to seek permission from the university's First Department - a branch of the FSB that exists at all Russian universities and research institutes, says Viacheslav Shuper, a geographer at the Russian Academy of Sciences in Moscow and MSU. He says that MSU geographers have been given similar instructions.
The minutes tell scientists to seek permission "despite the obvious absurdity of the whole situation". Vladimir Skulachev, director of the Belozersky Institute, did not respond to Nature's queries as to how the changes might affect research in his department.
Shuper and other academics say researchers across Russia have complained that their institutes are also asking for manuscript approval. "Many scientists in Russia don't dare to speak openly," says Shuper. "But I know that many are very unhappy about the degradation of their academic freedom."
Letting bureaucrats decide whether any piece of science is a state secret is not just nerve-wracking, but also burdensome, he says. For example, at some institutes, scientists who have written papers in English for foreign publication are obliged to translate them into Russian for the sake of the security service.
The changes are also bad for science, says Fyodor Kondrashov, a Russian biologist at the Centre for Genomic Regulation in Barcelona, Spain. "The problem is that it appears that all scientific output is being treated as potentially classified," he says. "This creates an unhealthy research climate with some scientists preferring not to share information - not to give a talk at a conference abroad, for example. I fear that the authorities will choose to apply this law selectively against their critics."
Sergey Salikhov, director of the Russian science ministry's science and technology department, told Nature that the government does not intend the amendment to restrict the publication of basic research. He says that it is not ordering universities or security services to proactively enforce the law over civilian research.
But the amendment leaves interpretation to the security services and science administrators, who tend to be over-zealous, says Gelfand. "Basically, anything new and potentially useful can now be interpreted to be a state secret," says Konstantin Severinov, a molecular biologist with the Skolkovo Institute of Science and Technology, who graduated from MSU.
The demand for approval runs counter to government efforts to strengthen and internationalize Russian science, says Severinov. The government aims to see 5 of the country's universities enter the top 100 in the world rankings by 2020, and is keen to attract leading foreign scientists to Russia.
Gelfand says that he will not comply with the rules imposed by his institute, and he encourages others to follow suit. "A sad sign of overall deterioration here is that many are sheepishly following any absurdity instilled by the bureaucrats," he says. "I am going to ignore it and hope that a sufficient number of colleagues would do the same."
© 2015 Nature Publishing Group, a division of Macmillan Publishers Limited. All Rights Reserved.
* * *
Nature / 20 October 2015
Russian roulette Attempts to keep foreign interests out of Russian research will only suppress the exchange of information, and risk damaging East-West relations.
|
Редакционная статья журнала Nature о том, что стремление к изоляции и желание развивать науку плохо сочетаются.
Despite decades of intellectual isolation, the Soviet Union produced some fine science. When it imploded, only a wave of foreign aid and philanthropy protected that excellent research base from collapse. The strategy worked: as individualism and entrepreneurship took hold in Russia, science regained its strength and started to look outwards - as any successful research endeavour must in the twenty-first century.
Yet Russian President Vladimir Putin believes that his country can increasingly go its own way, and centralism and anti-Western rhetoric are on the rise. Science is beginning to suffer from paranoid state control.
As we report, Russia has placed strict new rules on how its scientists can operate. In response to a recently amended law, Russian universities and research institutes have begun to instruct scientists to seek permission from the Federal Security Service before they submit papers or give talks at scientific conferences.
The wording of the law is vague, seemingly deliberately so. It effectively requires any work that is applicable to industry to be approved for publication. Russian scientists are rightly outraged by this return to inglorious Soviet practices.
Meanwhile, dozens of organizations that receive foreign funding (and which the Russian government suspects are involved in "political activities" - again vaguely defined) are under scrutiny. Officially, this is to identify and repel unwelcome foreign influence. Unofficially, there is a whiff of political scores being settled.
In May, the Dynasty Foundation, Russia's largest private science-funding organization, shut down after the Ministry of Justice labelled it a "foreign agent". Other philanthropic groups and foreign-funded foundations fear that they may soon find themselves on a list of "undesirable" organizations that the Russian parliament is drawing up.
This is not the 1960s. Today, fear and isolationism can only damage collaborative science. In turn, this will undermine Russia's efforts to modernize its struggling economy. Putin knows only too well that his country's dependence on oil and gas exports is a treacherous anachronism as the world steers away from fossil-fuel use. Wisely, the government has substantially stepped up its science funding in recent years. But neither a multibillion-rouble nanotechnology initiative, launched in 2007, nor attempts to create a number of world-class research universities and attract top Western scientists to Russian labs will bear fruit if fear and distrust continue to stand in the way of a liberal science culture.
Russia's annexation of the Crimean Peninsula last year, and its dubious role in the ongoing conflict in the rest of Ukraine, chilled East-West collaborations, in science and other fields. Russia's controversial military involvement in the civil war in Syria, although cautiously tolerated by Western powers, threatens to cause further tension.
Through large European research facilities such as the particle-physics laboratory CERN and the international nuclear-fusion project ITER, science can still offer a much-needed peaceful counterbalance in these politically turbulent times. But a disturbingly anti-Western speech to the upper chamber of the Russian parliament by Putin's top science adviser on 30 September - the same day that Russia began its air strikes in Syria - testifies to the level of misunderstanding that is currently poisoning East-West relations across the board.
The speech by Mikhail Kovalchuk, director of the Kurchatov Institute of nuclear science in Moscow and a key contact for many international collaborations, delivered a patently absurd account, riddled with lies and propaganda, of how international science is a US plot to undermine Russia. Such anti-Western sentiments are readily echoed in Russia: last week, a high-ranking IT adviser to the government said that Russia should stop training computer experts because they will before long be serving Western interests.
Making a bogeyman of the outside world - and in particular of the United States - is a populist political strategy intended to prepare the ground for anti-liberal isolationism. For Russia's scientific community, a crackdown on academic freedom and foreign support will be devastating. Putin, who frequently expresses his appreciation of science, must see that investment alone is not enough.
To pour cash into a system that stifles intuition, brilliance and truth will not help a nation that has always held scientists and explorers in great esteem. Even through difficult economic and political times, Russian science has produced a never-ending supply of great minds. It needs the freedom and respect to continue to do so.
© 2015 Nature Publishing Group, a division of Macmillan Publishers Limited. All Rights Reserved.
* * *
The Moscow Times / Oct. 21 2015
Russian Academia Divided Over FSB Vetting of Research Papers
|
Проректор МГУ Андрей Федянин опроверг информацию из статьи журнала Nature о предварительной экспертизе публикуемых научных работ в ФСБ, но опровержение убедило не всех. Как пишет The Moscow Times, единого мнения в российском научном сообществе нет.
A report this week of research papers and scientific articles becoming subject to vetting by the Federal Security Service (FSB) before publication rattled Russian academics, coming on the heels of several cases in which people have been accused of espionage and treason in connection with their professional activities.
The report published Tuesday by Nature, a respected international scientific journal, said that a biology institute at Russia's biggest university - the prestigious Lomonosov Moscow State University (MSU) - had instructed its scientists to get all research manuscripts approved by the FSB before submitting them to conferences or journals.
Though the report cited a transcript of a recent meeting during which the instructions were given to professors, MSU officials denied Wednesday that FSB vetting was practiced in the university.
The denials did not convince everyone, with some academics expressing fear that the Soviet censorship system was creeping its way back into Russian science.
"Our generation remembers it too well from Soviet times, when everything went through the KGB," Vyacheslav Shuper, a professor at MSU's geography faculty that he said received similar instructions about two weeks ago, told The Moscow Times by phone Wednesday.
In the most recent case of a Russian academic or expert being accused of treason over their work, Vladimir Golubev, a scientist from the Russian Federal Nuclear Center, was arrested in February for publishing a paper about explosives after speaking on the same topic at a conference in Prague.
He was accused of treason and disclosing state secrets by the FSB, but both he and his lawyer insisted that all the information in the paper had been published numerous times before in scientific journals, and therefore couldn't be considered secret. Golubev was amnestied in May.
Official Denial
According to the transcript of a meeting held on Oct. 5 at MSU's Belozersky Institute of Physicochemical Biology and cited by Nature, scientists should seek permission to publish their work from the university's First Department - an entity that exists at all Russian universities and research institutes and that is closely associated with the FSB.
They were told to get approval "despite the obvious absurdity of the whole situation," the report said.
Andrei Fedyanin, a pro-rector at MSU, confirmed Wednesday that the meeting had taken place, but said no FSB vetting was discussed.
"The meeting … was devoted to questions regarding improving the standard of the publications, their quality and citation rate," he told the Interfax news agency.
"Among other things, [scientists] were reminded about the regular protocol that has existed for decades at Moscow State University: Expert commissions [consisting of] our employees examine research papers to assess their scientific novelty and possibility of publication," Fedyanin said.
Neither the FSB nor the Education and Science Ministry responded to requests for comment sent by The Moscow Times on Wednesday.
Secret Instructions
Shuper from the geography faculty said that the department he works for held a meeting about two weeks ago where similar instructions were announced by the senior departmental staff. "We were told that examination reports had been reinstated. They showed us the format for such reports and named the people on the expert commissions," he told The Moscow Times in a phone interview.
The expert commissions that examine research papers prior to their submission for publication or presentation at conferences consist of fellow scientists, said Shuper, but they are supposed to examine the manuscripts for certain elements described in secret documents.
"[They are] so secret that they can't disclose them or take them out of their office," he said. "Where do you think they get these instructions from? Who coordinates their work, who creates these standards?" the professor added.
A similar procedure existed during Soviet times, he said: Scientific works were inspected for content that could endanger the country's security. The practice was never repealed, people simply started ignoring it when the Soviet Union collapsed, he added.
More Than Paperwork
At MSU, the practice has been reinstated selectively, according to Shuper: For example, there is no such requirement in the mechanics and mathematics faculty, or at MSU's Institute of Geography, a research center where Shuper also works that is separate from the geography faculty.
"But mechanics and mathematics are also important in terms of the country's security and defense potential - no less than geography," he said. "And if geography is so important, why is the Institute of Geography excepted [from the procedure]?" Shuper added.
MSU is not the only center of higher education dealing with the examination reports. Shuper said he had received a letter from the Urals, from a person who asked for their name and the name of their institution to be withheld, fearing retribution.
"At his university, scientists were forced to translate manuscripts written in English back into Russian for examining. But the experts are their fellow professors, and they know English very well," so the Russian version was likely prepared for someone else, Shuper suggested. According to him, the consequences of this practice could be grave. "It is a way of blocking whatever information you don't want to get out from doing so," said Shuper.
People who remember Soviet times weren't enthusiastic about bringing back examination reports, he added, but the younger scientists weren't too afraid of it, considering it was just additional paperwork. "In the beginning it will be just additional paperwork, but it's much more than that," Shuper told The Moscow Times.
FSB or Accounts?
Gennady Sardanashvili, a professor at the physics faculty of MSU, told The Moscow Times he hadn't heard anything about mandatory examination reports, either from his colleagues or the university administration.
"No one has talked about it to me personally. I've never heard about it from my colleagues or friends, or from the administration - just from that article [in Nature]," he told The Moscow Times on Wednesday.
Yevgeny Taranov, a Ph.D. student and researcher at the Vinogradsky Institute of Microbiology at the Russian Academy of Sciences, said his institute has always had a First Department, but it was unclear whether it was connected to the FSB.
"All I heard was our lab head saying that soon we would have to return to approving manuscripts before sending them off to international science journals, but that's it," he told The Moscow Times in written comments.
Oleg Gusev, a professor at Kazan Federal University (KFU) in Russia's republic of Tatarstan, told The Moscow Times that KFU scientists have to get approval for their manuscripts, but he didn't know the details of the procedure, and said it could be easily ignored.
Gusev echoed Taranov's doubts about the First Department being controlled by the FSB. "It might be some poor girl from the accounts department who checks the papers for information that could formally be considered secret, in order to save us from the FSB," by stopping scholars from unintentionally disclosing classified information, he said.
© Copyright 1992-2015. The Moscow Times. All rights reserved.
* * *
Sciences et Avenir / le 27-10-2015
Des momies de jeunes lions des cavernes découvertes en Russie
|
Несколько месяцев назад на севере Якутии ученые обнаружили хорошо сохранившиеся останки двух детенышей пещерного льва, вымершего около 10000 лет назад. До сих пор находили лишь кости этих животных.
Pour la première fois, des lions des cavernes en chair et en os ont été mis au jour. Une découverte exceptionnelle, qui donne à voir l'apparence réelle de ces animaux préhistoriques jusque-là seulement reconstituée.
Paléo-lionceaux
C'est un rêve qui devient réalité : on sait désormais à quoi ressemblait réellement l'un des plus grands prédateurs de la Préhistoire, le lion des cavernes. Des scientifiques viennent en effet d'annoncer avoir mis au jour deux corps momifiés de lionceaux ayant vécu il y a environ 11.000 ans sur le territoire de l'actuelle République de Sakha, également appelée Yakoutie (état fédéral de Russie). Une première mondiale, car, jusqu'à présent, les scientifiques ne disposaient que des os de ce prédateur des steppes de l'ère glaciaire. "C'est une découverte exceptionnelle", acquiesce Philippe Fosse, paléontologue à l'UMR 5608 TRACES (CNRS), à l'université de Toulouse. "Pour la première fois, on a un lion complet, avec sa fourrure". Or, jusqu'ici, la robe de ces "paléo-félins" n'était que déduite des peintures pariétales réalisées par les hommes préhistoriques. Ainsi, c'est un peu des lionnes de la grotte Chauvet que l'on voit tout à coup, en vrai.
Certes il n'est pas rare qu'avec la fonte du pergélisol, un animal préhistorique soit délivré des glaces. Mais d'habitude, il s'agit plutôt d'ongulés (bisons, chevaux...), de mammouths, ou de rhinocéros laineux, que de carnivores. Surtout, "le lion des cavernes est un animal solitaire", explique Philippe Fosse. "Contrairement aux ongulés qui vivent en groupe, la probabilité de découvrir un individu congelé est quasi nulle !". Comble de chance, les scientifiques disposent non pas d'un mais de deux petits lions des cavernes. En raison du bon état de conservation de leurs tissus, la qualité de l'ADN prélevé devrait venir éclairer le débat de sa parenté avec le lion d'Afrique actuel ou avec le tigre d'Asie. De plus, le passage au scanner révèlera probablement le contenu stomacal et, de fait, quelle était leur alimentation (lait, types de proie...).
Apparence physique du lion des cavernes
Toutefois, en raison de leur jeune âge au moment de leur mort, il sera difficile de tirer des conclusions concernant la couleur du pelage que pouvaient avoir les adultes. Selon le paléontologue français, "La robe évolue avec l'âge chez les grands félins. Chez le lion des cavernes elle ne devait se stabiliser que vers 4,5 ou 5 ans". Il ne faut donc pas s'attendre à ce que la question de la présence ou de l'absence de rayures soit définitivement tranchée après analyses complètes. De plus "la couleur devait changer en fonction des saisons, comme c'est le cas chez un chat sauvage qui vit actuellement au Nord-Est de la Sibérie : les teintes devaient être plus foncées l'hiver", ajoute le scientifique. De même pour la densité du pelage. "Ce chat double presque de volume pour affronter une amplitude thermique d'environ 70°C.". Ainsi, teintes et densité de poils devraient permettre d'établir à quelle saison les lionceaux sont morts.
Enquête
Les scientifiques vont alors pouvoir se livrer à une véritable analyse médico-légale : les lions présentent-ils des traces de morsures, de blessures au scanner ? Ont-ils succombé à une maladie, à la famine ? Les causes de leur décès seront peut-être révélées par les analyses en cours. L'Académie des sciences de Sakha a dores et déjà annoncé dans le Siberian Times qu'elle présentera les résultats des recherches fin novembre 2015.
© Sciences et Avenir.
* * *
Nanotechnology News / October 28th, 2015
The world's fastest nanoscale photonics switch: Russian scientists developed the world's fastest nanoscale photonics switch
|
Физики из МГУ в сотрудничестве с коллегами из Австралийского национального университета создали компактный и очень быстрый фотонный переключатель, работающий на кремниевых наноструктурах. Устройство способно переключать оптические импульсы за несколько фемтосекунд.
Статья "Ultrafast All-Optical Switching with Magnetic Resonances in Nonlinear Dielectric Nanostructures" опубликована в журнале Nano Letters.
This work belongs to the field of photonics - an optics discipline which appeared in the 1960-s, simultaneously with the invention of lasers. Photonics has the same goals as electronics does, but uses photons - the quanta of light - instead of electrons. The biggest advantage of using photons is the absence of interactions between them. As a consequence, photons address the data transmission problem better than electrons. This property can primarily be used for in computing where IPS (instructions per second) is the main attribute to be maximized. The typical scale of eletronic transistors - the basis of contemporary electronic devices - is less than 100 nanometers, wheres the typical scale of photonic transistors stays on the scale of several micrometers. Nanostructures that are able to compete with the electronic structures - for example, plasmonic nanoparticles - are characterized by low efficiency and significant losses. Therefore, coming up with a compact photonic switch was a very challenging task.
Three years ago several groups of researchers simultaneously discovered an important effect: they found out that silicon nanoparticles are exhibit strong resonances in the visible spectrum - the so-called magnetic dipole resonances. This type of resonance is characterized by strong localization of light waves on subwavelength scales, inside the nanoparticles. This effect turned out to be interesting to researches, but, according to Maxim Shcherbakov, the first author of the article published in Nano Letters, nobody thought that this discovery could create a basis for development of a compact and very rapid photonic switch.
Nanoparticles were fabricated in the Australian National University by e-beam lithography followed by plasma-phase etching. It was done by Alexander Shorokhov, who served an internship in the University as a part of Presidential scholarship for studying abroad. The samples were brought to Moscow, and all the experimental work was carried out at the Faculty of Physics of Lomonosov Moscow State University, in the Laboratory of Nanophotonics and Metamaterials.
"In our experimental research me and my colleague Polina Vabishchevich from the Faculty used a set of nonlinear optics methods that address femtosecond light-matter, - explains Maxim Shcherbakov. - We used our femtosecond laser complex acquired as part of the MSU development program".
Eventually, researches developed a "device": a disc 250 nm in diameter that is capable of switching optical pulses at femtosecond rates (femtosecond is a one millionth of one billionth of a second). Switching speeds that fast will allow to create data transmission and processing devices that will work at tens and hundreds terabits per second. This can make possible downloading thousands of HD-movies in less than a second.
The operation of the all-optical switch created by MSU researchers is based on the interaction between two femtosecond pulses. The interaction becomes possible due to the magnetic resonance of the silicon nanostructures. If the pulses arrive at the nanostructure simultaneously, one of them interacts with the other and dampers it due to the effect of two-photon absorption. If there is a 100-fs delay between the two pulses, the interaction does not occur, and the second pulse goes through the nanostructure without changing.
"We were able to develop a structure with the undesirable free-carrier effects are suppressed, - says Maxim Shcherbakov. - Free carriers (electrons and electron holes) place serious restrictions on the speed of signal conversion in the traditional integrated photonics. Our work represents an important step towards novel and efficient active photonic devices - transistors, logic units, and others. Features of the technology implemented in our work will allow its use in silicon photonics. In the nearest future, we are going to test such nanoparticles in integrated circuits".
© Copyright 1999-2015 7th Wave, Inc. All Rights Reserved.
* * *
|
предыдущий месяц |
1998-2015 |
следующий месяц |
|
|