|Российская наука и мир|
(по материалам зарубежной электронной прессы)
Phys.Org / September 4, 2018
Brown bear saliva found to contain chemical that kills Staphylococcus aureus
Российские биохимики при участии американских коллег обнаружили в слюне сибирского бурого медведя микроорганизмы Bacillus pumilus. Вырабатываемый ими антибиотик амикумацин защищает от золотистого стафилококка. Поскольку стафилококки часто вырабатывают устойчивость к медицинским препаратам, открытие нового антибиотика может помочь лечению.
A team of researchers affiliated with multiple institutions in Russia and the U.S. has found that Siberian brown bears have a chemical in their saliva that has been found able to kill Staphylococcus aureus bacteria. In their paper published in Proceedings of the National Academy of Sciences, the group describes their study of the microbiome of a subspecies of brown bear and what they found.
The Siberian brown bear lives in Mongolia, northern parts of China, and in Siberia. While mostly vegetarian, they will on occasion kill and eat caribou, elk and fish - giving them a varied diet that has a profound impact on their microbiome. The researchers were interested in studying the biome of the brown bear as part of a larger effort to study the biome of a large number of wild animals. The goal of the larger effort is to find naturally occurring chemicals that are able to kill bacteria that infect humans - bacteria that are evolving to become resistant to traditional treatments.
To learn more about the microbiome of Siberian brown bears, the team captured several specimens in the taiga (a forested part of Siberia) and took saliva swabs which they carried back to their lab. There they used what they describe as state-of-the-art screening techniques to identify chemicals and organisms in the saliva samples.
The team reports that they found evidence of Bacillus pumilus in the saliva, which produces an antibiotic chemical called amicoumacin A. The researchers suggest the bears get the microbes when they consume certain types of vegetation. After they found B. pumilus in the saliva, the researchers focused their study on it specifically and in so doing discovered the means by which it does battle with bacteria, specifically S. aureus - a type of bacteria associated with human skin infections. S. aureus is also one of the types of bacteria that are becoming resistant to traditional treatments, thus a naturally occurring chemical that can help humans fight it would be quite valuable.
The team plans to continue studying the biome of the brown bear, along with other wild animals, in hopes of discovering the means by which they ward off bacteria that are giving us humans so many problems.
© Phys.org 2003 - 2018, Science X network.
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Photonics Media / Sept. 13, 2018
Rostec Installs Mirror at Russian Academy's Large Altazimuth Telescope at Russian Academy of Sciences Observatory
На самом большом оптическом телескопе в Евразии (Специальная астрофизическая обсерватория РАН в Карачаево-Черкесии) установлено новое зеркало диаметром 6 метров и весом более 40 тонн. Новая оптика увеличит дальность наблюдения в 1,5 раза.
Civil and military industrial technology provider Rostec has installed a mirror at the Large Altazimuth Telescope (BTA) in the Special Astrophysical Observatory of the Russian Academy of Sciences (SAO RAS) in Karachay-Cherkessia.
The key element of BTA installed by Rostec is a mirror with a 6-m diameter. The surface of the mirror shape is now being adjusted, and the curvature and deviation of the mirror surface from the specified form are being measured. This will help to adjust the supporting systems that the mirror sits on. The final step will be to apply a reflective coating to the surface with a special vacuum unit.
"Our technologies allow us to create a mirror weighing several dozen tons and process it with nm precision," said Oleg Yevtushenko, executive director of Rostec. "The combination of the large size of the mirror and the unique reflective optical characteristics will allow Russian scientists to work with one of the most advanced telescopes in the world over the coming decades. The new optics increase the range of observations by 1.5×, greatly expanding the horizons of research."
In order to avoid deformation of the mirror, which weighs more than 40 tons, 60 special supporting systems are used when pivoting the telescope. Employees of the Lytkarino Optical Glass Factory (LZOS) of Shvabe Holding worked to improve the quality, accuracy, and penetrating power of the mirror.
"The history of the telescope began with making two mirrors in the 1970s," said Alexey Patrikeev, general director of Shvabe Holding. "The first was used in the first four years, after which it was replaced by a more advanced one. After nearly 40 years of operation, the surface quality has deteriorated significantly, and it was decided to send the first mirror to LZOS for an upgrade. Today, adjusted to the new weight, it has been successfully installed into BTA. The shape of the surface was also evaluated. The RAS has already received the first test shots. The final work on improving the mirror surface and further configuration, which will complete the preparatory phase, is now underway. The upgrade will provide 40 to 50 years of trouble-free operation of the telescope."
Rostec is a Russian State Corporation established in 2007 with the purpose of facilitating the development, manufacture, and export of high-tech industrial products for both civil and military purposes. It incorporates more than 700 entities that currently form 11 holdings operating in the military-industrial complex and four holdings active in civilian industries, as well as over 80 directly supervised organizations.
© 2018 Photonics Media.
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Nanowerk / Sep 13, 2018
Scientists study light to create technologies of the future
Ученые Южно-Уральского государственного университета исследуют эффекты проявления так называемого спин-орбитального взаимодействия света, то есть взаимовлияния траектории распространения света и его поляризации. Полученные результаты можно будет использовать в различных областях - например, в медицине.
Scientists of the Faculty of Physics of the South Ural State University (SUSU) Institute of Natural Sciences and Mathematics predict new optical effects in light beams which in perspective will help create technologies of the future, and even reveal cancer in early stages.
Spin-orbital Interaction of Light
A big project on Spin-orbital Interaction of Light for Photonics of the Future by the scientists of Institute of Natural Sciences and Mathematics deals with searching for and studying the effects of the occurring spin-orbital interaction of light, that is the interinfluence between the light propagation path and such property of light as polarization.
The research is supervised by Natalia Kundikova, Doctor of Sciences (Physics and Mathematics), Professor, Dean of the Faculty of Physics of the SUSU Institute of Natural Sciences and Mathematics, chief research fellow at Non-linear Optics Laboratory of the Institute of Electrophysics at the Urals Division of the Russian Academy of Sciences. Dr. Kundikova is holder of Galileo Galilei award for research in the field of physical optics.
"According to classical physics, a light beam is characterised with polarization and propagation direction. In quantum physics, spin and orbital angular momentums of photon correspond to these characteristics. The existence of spin-orbital interaction of photon in optically-inhomogeneous medium was first proved by experiment at our university in 1991, by a group of scientists guided by the Corresponding Member of the Russian Academy of Sciences Boris Zeldovich. This effect was revealed by experiments in turning speckle pattern of circularly polarized light passing through optic fiber in case of altered sign of circular polarization," explains Natalia Kundikova.
New Optical Effects Predicted
A light beam has spin angular momentum (polarization) and external orbital angular momentum (trajectory). All the effects of the occurring spin-orbital interaction studied earlier are related to influence of one of the angular momentums on others. The assumption of the scientists of South Ural State University states that two angular momentums may simultaneously influence the third angular momentum.
"Through experiments we were able to demonstrate that light polarization and trajectory may influence the structure of a light beam. As for the other two effects, it's just a prediction for now. We need to understand in what conditions these effects may be observed, and try studying them through experiments. But it's a very difficult task," shares Dr. Kundikova.
The peculiarity of optical experiments is that scientists have to create their own installations for experiments. To do that, optical constructors are used which allow to produce beams with ring structure. The scientists from South Ural State University are planning, jointly with their colleagues from France, to study the so called "bagel" beams with special wave front. It is proposed to use such beams for early cancer detection.
Photonics for Creation of the Technologies of the Future
Originally, photonics dealt with studying the basic working principles of optical signals and fields, as well as their application for creation of devices. But today in comprises such fields as laser technology, optical computing, medical diagnostics and therapy.
That is why the project by the SUSU scientists on Spin-orbital Interaction of Light for Photonics of the Future is of huge importance for development and application of optics in different fields. For instance, one of the Department's research studies aims at improving optic-fiber sensors for measuring various physical quantities.
Following the research results, 2 reports were presented at the 24th Congress of the International Commission for Optics (Tokyo, Japan), and a presentation was delivered at the 4th International Conference on Optical Angular Momentum (Anacapri, Italy). In October 2018 it is planned to present reports at international conferences in the Netherlands and in France.
© 2018 Nanowerk. All Rights Reserved.
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Great Lakes Ledger / Monday, September 17, 2018
The Mysterious Yamal Crater, The So-Called "End of The World Crater," Formed By Unusual Cryovolcanic Activity
Геологи из МГУ имени М.В.Ломоносова пришли к выводу, что гигантский кратер, появившийся в 2014 году на Ямале, возник в результате процесса криовулканизма. До сих пор это явление на Земле известно не было, зато наблюдалось на ледяных космических телах.
Russian scientists concluded that the mysterious Yamal crater, the so-called "end of the world crater" formed in 2014 on the remote Yamal Peninsula in northern Siberia was the result of unusual cryovolcanic activity on Earth. Cryovulcanism is generally observed on other planets and satellites.
A cryovolcano is a volcano of ice and water, but its basic structure is practically identical to the Earth's volcanic rocks. In extremely cold conditions, a cryovolcano does not release molten rocks, but water and other chemical compounds, such as ammonia and methane, in a liquid and gaseous state.
According to the new research published in Scientific Reports, the mysterious Yamal crater appears to be the result of the collapse of a large pingo, a small hill typical of polar regions, which formed inside a lake that later dried up.
This allowed a large talik, a layer or body of unfrozen soil in a permafrost area, underneath it to freeze. The pingo collapsed under cryogenic hydrostatic pressure accumulated in the closed system of the frozen talik. This happened before the freezing was complete, when a wet soil core remained unfrozen and stored a large amount of carbon dioxide dissolved in interstitial water.
When the structure reached the end of the gas phase, the resulting overpressure exceeded the confining stress of the lithosphere and the force of the superimposed ice. When the pingo exploded, the demarcation of the crater followed the cylindrical shape of the remaining talik nucleus, conclude the scientists, headed by Sergey N. Buldovicz of Moscow's Lomonosov University.
The "end of the world crater," the mysterious Yamal crater, was discovered in 2014 on the Yamal peninsula. However, its origin was unknown until now.
Several theories included the fall of a meteorite or the melting of permafrost due to the global warming. It quickly filled with water and by the fall of 2016 became a lake, with a maximum depth of only 52 meters and approximately 25 meters in diameter. Now its mystery has been solved out as the scientists consider that the Yamal crater formed by unusual cryovolcanic activity.
Copyright © 2018 Great Lakes Ledger.
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IFLScience / 18 Sep 2018
Medieval Board Game Found In A Secret Chamber Under A 13th-Century Russian Castle
Археологи обнаружили в средневековом Выборгском замке кирпич XVI века с нарисованным на нем полем для настольной игры. Ученые предположили, что речь идет об игре "Мельница", появившейся в IX-X веках, с той лишь разницей, что обычно в нее играли на досках.
Archaeologists have found what appears to be a Medieval board game inside the secret chamber of a 13th-century fortress close to the Russian-Finnish border. According to a social media post from Vladimir Tsoi, director of the Vyborg Museum-Reserve, it might just be the "most intriguing" discovery since archaeologists began excavations in and around the castle earlier this year.
The fortress is Vyborg Castle, located on a teeny tiny island overlooking the town of Vyborg in Leningrad Oblast in northwestern Russia. It was built by the Swedes in 1293 CE but its roots may be older still - possibly to an earlier Karelian garrison, Newsweek reports.
In the intervening years, it has passed hands several times between Russia and Finland, most recently in 1944 when it was taken back by the Soviet Union.
The object itself is basic - a clay tablet with markings of intersecting squares - but experts believe it is an old edition of a two-player strategy game called Nine Men's Morris, which has existed in some incarnation or another for centuries. Copies have been found everywhere from the UK to China to the Roman Empire and today you may know it as Cowboy's Checkers.
The aim of the game is to capture your opponent's pieces or "men". To do this, you must build "mills" or rows of three men and for every mill you build, you earn one "man". The winner is declared when their opponent is unable to build any more mills - ie they are left with only two men.
In the standard game, each player starts with nine men but depending on the version, it could be a few as three or as high as 12.
Intriguingly, the game was found inside an underground chamber that may offer a secret passageway to the town of Vyborg, at least if historical documents are to be believed. According to Vyborg Museum-Reserve, castle records dating back to the mid-16th century mention a so-called "secret house" that leads to the shore of the strait. But for now, the evidence that it makes it as far as the shore remains inconclusive.
The board game is not the first treasure found within the castle walls. This summer, archaeologists unearthed a collection of copper coins dating back to the early 19th century, Gizmodo reports.
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The Independent / 21 Sep 2018
Oldest known animal fossil discovered in Russian cliffs
Discovery solves "decades-old mystery that has been the Holy Grail of palaeontology".
Российские, немецкие и австралийские ученые подтвердили, что обитавшая в морях эдиакарского периода дикинсония (Dickinsonia) относилась к царству животных, являясь, таким образом, самым древним его представителем возрастом 558 млн лет. Об этом свидетельствуют сохранившиеся остатки органики - холестероиды, обнаруженные в найденных в районе Белого моря образцах.
Hailed as "the Holy Grail of palaeontology", scientists have confirmed that an unusual oval shape found preserved in Russian cliffs is the oldest known animal fossil.
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Debate has raged in the research community for decades over the identity of Dickinsonia, which roamed the Earth 558 million years ago during the Ediacaran period. Life forms from this period are thought to be the first ever large, multicellular creatures, but they are so different to anything alive today that their exact identity has remained a mystery.
Previously experts have suggested the metre-long Dickinsonia could be a fungus or a giant amoeba. But experiments using a specimen from north west Russia has revealed their true identity as some of the first ever animals. The fossil was so well preserved that when researchers drilled into it they found traces of cholesterol, a type of fat that is a clear indicator of animal life.
"The fossil fat molecules that we've found prove that animals were large and abundant 558 million years ago, millions of years earlier than previously thought," said Professor Jochen Brocks from the Australian National University.
The current received wisdom in palaeontology is that large animals began to dominate around the time of the Cambrian explosion around 541 million years ago. At this point creatures recognisable as worms, molluscs and other modern groups appear in the fossil record, but the new discovery suggests they were preceded by a wave of animals that looked like Dickinsonia. Besides high levels of cholesterol, the fossil was lacking in chemical markers known to be associated with fungi.
"Scientists have been fighting for more than 75 years over what Dickinsonia and other bizarre fossils of the Edicaran biota were," said Professor Brocks, who "couldn't believe" the results when they were first brought to him by PhD student Ilya Bobrovskiy. He added: "The fossil fat now confirms Dickinsonia as the oldest known animal fossil, solving a decades-old mystery that has been the Holy Grail of palaeontology." The specimen was excavated from a remote cliff face near the White Sea by Mr Bobrovskiy.
"I took a helicopter to reach this very remote part of the world - home to bears and mosquitoes - where I could find Dickinsonia fossils with organic matter still intact," he said.
Mr Bobrovskiy noted the difficulty in finding a fossil as old as this Dickinsonia specimen that still contained traces of organic material.
"Most rocks containing these fossils such as those from the Ediacara Hills in Australia have endured a lot of heat, a lot of pressure and then they were weathered after that," he said. "These are the rocks that palaeontologists studied for many decades, which explained why they were stuck on the question of Dickinsonia's true identity."
The results of this work, published in the journal Science, mark a new way for scientists to examine the prehistoric world.
"Looking at molecules in these ancient organisms is a game changer," said Professor Brocks.
Historically, palaeontologists have exclusively looked at the structure of ancient creatures, but adding molecular analysis to these studies allows them to explore them in far greater depth.
Daily News & Analysis / Sep 26, 2018
Scientists are developing an optical clock for flights to Mars
Во Всероссийском научно-исследовательском институте физико-технических и радиотехнических измерений Росстандарта (ВНИИФТРИ) разрабатывают высокоточные оптические часы, которые можно будет использовать в космической технике, например, во время будущих полетов на Марс.
Scientists from the All-Russian Scientific Research Institute for Physical-Engineering and Radiotechnical Metrology (VNIIFTRI) are developing an optical clock for future spaceflights, including those to Mars, the VNIIFTRI Director General, Sergei Donchenko, said.
"We are developing a new optical clock that will be used in future space vehicles, for example, for flights to Mars. I think that they will start being used within 10-15 years. It is unlikely that someone will fly to Mars earlier," Donchenko said.
He added that current models of the optical clock were too big to be used in a spacecraft. Donchenko also announced creation of an acoustic gas thermometre that would allow to measure the temperature in Arctic areas as well as on the Moon.
"One more invention is an acoustic gas thermometre, the use of which is especially important for measuring low temperatures. For example, a Russian space vehicle will head for the Moon, where the temperature is minus 150-200 degrees Celsius (minus 238-328 degrees Fahrenheit), but how can one understand whether it will operate under such temperatures. One checks this at special sites. But who can prove that the needed temperature is reached during the tests. Now, when scientists of our institute have created the new thermometre, one can determine the real temperature very precisely," he said.
In March, Russian cosmonaut Oleg Artemyev said that Russia's manned spaceflight to Mars was going to happen in 2030-2040, adding that the activities of US company SpaceX, which was also planning flights to the Red Planet, may motivate Russia to launch their spacecraft earlier.
© 2018 Diligent Media Corporation Ltd.
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EurekAlert / 28-Sep-2018
Scientists studied the influence of gravity on liquid evaporation characteristics
Сотрудники Сибирского федерального университета и Института вычислительного моделирования СО РАН рассчитали, как будут проходить процессы испарения в двухслойной системе "жидкость - пар" с учетом толщины слоя и воздействия гравитации. Созданная математическая модель может использоваться при разработке систем охлаждения различных электронных устройств, используемых в том числе в космосе.
A team from Siberian Federal University (SFU) together with their colleagues from the Institute of Computational Modeling of SB RAS presented a calculation describing the structure of flows and evaporation processes in the two-layer system with liquid - gas-vapour mixture. The main attention is paid to the influence of two factors, namely, gravity and the thickness of the liquid layer.
The understanding of mechanisms that determine the nature of flows and vaporization (condensation) effects is important for the development of micro-sized cooling devices for satellites and life support systems of the orbital space station, as well as in material studies and chemical industry. The results of the study were published in the Microgravity Science and Technology journal.
Heat and mass transfer processes are observed everywhere. One of them is called convection, when fluxes of the matter and energy are transferred in flows. Permanent motion occurs in the liquid. Upper layers cool, get heavier, and go down, and liquid in the lower layers has higher temperature and rise to the top. One of the reasons for heat loss at the border between liquid and gas is related with evaporation. A part of molecules has higher energy in comparison with others, and it is enough to break intermolecular bonds and to be released from the surface. This is how liquid particles transfer to their gas state, i.e. become vapor. An opposite effect is called condensation and takes place when vapor molecules contact with cooled liquid surface.
"The described processes depend on internal and external conditions: properties of the medium (liquid and surrounding gas or gas-vapor mixture), temperature regime of the system, its geometry (e.g. the width of the channel in which liquid and vapor are located), and the effect of gravity. In our work we focused on describing the influence of the two latter factors," says Victoria Bekezhanova, Dr. habil. in physics and mathematics, Professor of SFU, and leading researcher in the Department of differential equations in mechanics at the Institute of Computational Modeling of SB RAS.
The presented mathematical model describes convective processes in the two-layer liquid and gas-vapor system. It is based on the most important equations of fluid dynamics (the Navier - Stokes equations) and takes into account several additional factors. For example, the thermodiffusion effect can lead to the formation of zones with different concentrations of molecules depending on the temperature. Under the influence of various factors a liquid can be stratified into warm and cold layers, whereby some physical properties of the medium (density, superficial tension, and so on) can be changed. A system in which upper layers are cooler than lower ones is unstable, because convective motion occurs in the fluid being in a gravity field (i.e. cold liquid goes down, and hot one goes up). This process can be controlled, for example, by means of changing the thickness of the liquid layer. With decrease of the height of the liquid layer, one can suppress convection due to the increasing influence of the thermocapillary effect that causes hot liquid to move along the liquid-gas interface.
"Traditionally, a need to explore convective processes is required for developments in thermal physics, chemical industry, material studies, and biological medicine. Our recent results may be of use for modifying liquid cooling systems in various micro- and mini-sized electronic devices, including those used on board of space stations or new generation satellites, and also for improving thermal control systems, thermal drying technologies, or applying coatings with given characteristics (thickness, form, mechanical or chemical properties, and so on," concludes Victoria Bekezhanova.
Copyright © 2018 by the American Association for the Advancement of Science (AAAS).
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Phys.Org / September 27, 2018
Extended emission filaments found in the galaxy Markarian 6
Астрономы из Специальной астрофизической обсерватории РАН впервые получили глубокие изображения галактики Маркарян-6, расположенной на расстоянии 263 млн световых лет от Земли, и обнаружили протяженные газовые нити, предположительно отходящие от внешней материи, вращающейся перпендикулярно диску самой галактики. Структура простирается примерно на 130 тыс. световых лет.
Russian astronomers have conducted a study of large-scale morphology and kinematics of the ionized gas in the galaxy Markarian 6. The research, in addition to mapping the ionized gas in the stellar disc, has identified a system of faint, extended emission filaments in the galaxy. The finding is detailed in a paper published September 16 on the arXiv pre-print server.
Markarian 6 (or Mrk 6 for short) is a Seyfert galaxy located some 263 million light years away. The galaxy showcases complex radio emission structure consisting of a compact radio core and elongated multicomponent radio structures resembling jet elements or hot spots.
Mrk 6 also exhibits complex kinematics of ionized gas, which is still not fully understood. In order to learn more about this subject, as well as to better understand Mrk 6's morphology, a team of astronomers led by Aleksandrina Smirnova from the Special Astrophysical Observatory of the Russian Academy of Sciences (SAO RAS) in Nizhny Arkhyz, Russia, has conducted 3-D spectroscopic observations of this galaxy.
For their observational campaign, the researchers used the six-meter SAO RAS telescope and the one-meter Schmidt telescope at the Byurakan Astrophysical Observatory (BAO) in Armenia. Their observations were complemented by archival data provided by the Multi-Pupil Field Spectrograph (MPFS) mounted on six-meter SAO RAS telescope.
"Using various techniques of optical observations at the six-meter Russian telescope (emission-line images, long-slit and 3-D spectroscopy), we have studied large-scale morphology and kinematics of the ionized gas in the Seyfert galaxy Mrk 6," the astronomers wrote in the paper.
Besides providing essential information about the ionized gas in Mrk 6's stellar disc, the observations resulted in unveiling the presence of a complex structure of the Extended Emission-Line Regions (EELRs) in Mrk 6 consisting of a gaseous disc co-rotating with the galaxy's stellar disc and off-plane ionizing filaments. The structure extends to a projected distance of about 130,000 light years.
The origin of the extended emission filaments in Mrk 6 remains uncertain. The researchers suppose that they were formed by an external matter orbiting orthogonally to the stellar disc. This could mean that origin of the filaments in Mrk 6 is similar to that in gaseous clouds in tidal tails and debris caught in the ionization cone of the active galactic nucleus (AGN).
"Kinematics as well as an ionization state of the filament gas suggest the scenario that hard radiation of the active nucleus illuminated the matter accreted from outside and orbiting almost orthogonally to the Mrk 6 stellar disc," the paper reads.
However, the astronomers added that a possible source of gas accretion is still unknown. They that new deep neutral atomic hydrogen radio observations of Mrk 6 will make it possible to reveal a clear picture of the gaseous environment and accretion processes.
© Phys.org 2003-2018, Science X network.
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