Май 2022 г.

Российская наука и мир (по материалам зарубежной электронной прессы)

CONTENTS / ОГЛАВЛЕНИЕ


• Which parts of Mars are the safest from cosmic radiation?
• Scientists synthesize new, ultra-hard material
• Creating a biomimetic algorithm to find epileptogenic areas of the brain
• New method for synthesizing titanium-based nanocomposite coatings
• Russian-Chinese research team has sequenced genome of Thalictrum
• Ces chercheurs inventent un nouveau matériau explosif de synthèse
• Paleontologists have discovered the jaws of a rare bear in Taurida Cave
• Why are Russian Baikal salmon doubling in size? Scientists baffled
• The curious case of the Arctic desert island that’s not actually an island

Одной из проблем, с которой столкнутся астронавты на Марсе, станет солнечная и космическая радиация, от которой разреженная атмосфера планеты почти не защищает. Команда китайских, немецких и российских ученых изучила марсианскую поверхность, чтобы найти районы с наименьшим уровнем радиации. Исследователи пришли к выводу, что лучшие места для будущих поселений должны быть расположены в низменных районах на глубине 1-1,6 м под поверхностью, например, на Великой Северной равнине (Vastitas Borealis) и в долинах Маринер (Valles Marineris).

In the coming decade, NASA and China plan to send the first crewed missions to Mars. This will consist of both agencies sending spacecraft in 2033, 2035, 2037, and every 26 months after that to coincide with Mars being in "Opposition" (i.e., when Earth and Mars are closest in their orbits). The long-term aim of these programs is to establish a base on Mars that will serve as a hub that accommodates future missions, though the Chinese have stated that they intend for their base to be a permanent one.
The prospect of sending astronauts on the six-to-nine-month journey to Mars presents several challenges, to say nothing of the hazards they’ll face while conducting scientific operations on the surface. In a recent study, an international team of scientists conducted a survey of the Martian environment - from the peaks of Mount Olympus to its underground recesses - to find where radiation is the lowest. Their findings could inform future missions to Mars and the creation of Martian habitats.
The team was led by Jian Zhang and his Ph.D. supervisor Dr. Jingnan Guo of the School of Earth and Space Sciences at the University of Science and Technology of China (USTC). They were joined by colleagues from the USTC and the CAS Center for Excellence in Comparative Planetology in China, the Institute of Experimental and Applied Physics (IEAP) in Kiel, Germany, and the Russian Academy of Science’s (RAS) Institute of BioMedical Problems and the Skobeltsyn Institute of Nuclear Physics (SINP) in Moscow.
When it comes to missions to Mars and other locations beyond Low Earth Orbit (LEO), radiation is always a going concern. Compared to Earth, Mars has a very tenuous atmosphere (less than 1% of the air pressure), and there is no protective magnetosphere to shield the surface from solar and cosmic radiation. As a result, scientists theorize that harmful particles, particularly galactic cosmic rays (GCRs), could propagate and interact directly with the atmosphere and even reach the subsurface of Mars.
However, the level of radiation exposure depends on just how thick the atmosphere is, which changes due to altitude. Within low-lying areas like Mars’ famous canyon system (Valles Marineris) and its largest crater (Hellas Planitia), atmospheric pressure is estimated at over 1.2 and 1.24 kPa, respectively. This is about twice the average of 0.636 kPa and up to ten times the atmospheric pressure at high-elevation locations like Olympus Mons (the largest mountain in the Solar System). As Dr. Jingnan Guo explained to Universe Today via email:
"Different elevation means different atmospheric thickness. High-altitude places generally have a thinner atmosphere on top. Energetic particle radiation from space needs to traverse through the atmosphere to reach the surface of Mars. If the atmospheric thickness changes, the surface radiation may also change. Thus elevation could influence the surface radiation of Mars."
To this end, the team considered the influence of atmospheric depths on Martian radiation levels. This included the absorbed dose measured in rads; the dose equivalent, measured in rems and sieverts (Sv); and the body effective dose rates induced by GCRs. This consisted of modeling the radiation environment using a state-of-the-art simulator based on the GEometry And Tracking (GEANT4) software developed by CERN.
Known as Atmospheric Radiation Interaction Simulator (AtRIS), this software employs Monte Carlo probability algorithms to simulate particle interactions with the Martian atmosphere and terrain. As Dr. Guo illustrated:
"We use a Monte Carlo approach called ‘GEANT4’ to model the transport and interaction of energetic particles with the Martian atmosphere and regolith. The Mars environment is set up considering the Mars atmospheric composition & structure and regolith properties.
"The input particle spectra on top of the Mars’s atmosphere are obtained also from data-calibrated models which describe the omnipresent particle radiation environment in the interplanetary space that includes charged particles of different species which are mainly protons(~87%), helium ions (12%) and also small traces of heavier ions such as carbon, oxygen and irons."
They found that higher surface pressures can effectively reduce the amount of heavy-ion GCR radiation, but this is not enough to protect future astronauts on Mars. Unfortunately, the presence of this shielding can lead to "cosmic ray showers," where the impact of GCRs against shielding creates secondary particles that can flood a habitat’s interior with varying levels of neutron radiation (aka. neutron flux). These can contribute significantly to the effective dose of radiation astronauts will absorb. They determined that both the neutron flux and effective dose peak at around 30 cm (1 foot) below the surface. Luckily, these findings offer solutions as far as using Martian regolith for shielding is concerned. Said Dr. Guo:
"For a given threshold of the annual biologically-weighted radiation effective dose, e.g., 100 mSv (a quantity often considered as the threshold below which radiation-induced cancer risk is negligible), the required regolith depth ranges between about 1 m and 1.6 m. Within this range, at a deep crater where the surface pressure is higher, the needed extra regolith shielding is slightly smaller. While on top of Olympus Mons, the needed extra regolith shielding is thicker."
Based on their findings, the best sites for future habitats on Mars would be located in low-lying areas and at depths of 1 m and 1.6 m (3.28 to 5.25 ft) beneath the surface. Therefore, the Northern Lowlands, which make up most of the northern hemisphere (aka. Vastitas Borealis), and Valles Marineris would be suitable locations. In addition to having thicker atmospheric pressure, these regions also have abundant water ice just beneath the surface.
Apart from the obvious benefit of having locally-sourced water, the enhanced hydrogen content in the water could also provide additional shielding against neutron-contributed radiation. The role of subsurface water ice as a source of natural shielding for Martian habitats was the subject of a previous study conducted by Lennart Röstel (a former student from the University of Kiel) in close collaboration with Dr. Guo and other colleagues from Kiel University.
If all goes according to plan, astronauts will be setting foot on the Martian surface in just over a decade. This will consist of transits lasting six to nine months (barring the development of more advanced propulsion technology) and surface operations of up to 18 months. In short, astronauts will have to contend with the threat of elevated radiation for up to three years. As such, detailed mitigation strategies need to be developed well in advance.
NASA and other space agencies have invested considerable time, energy, and resources to develop habitat designs that leverage 3-D printing, In-Situ Resource Utilization (ISRU), and even electromagnetic shielding to ensure astronaut health and safety. However, there are still unanswered questions about how effective these strategies will be in practice, especially when considering the amount of time crews will be spending on the Martian surface.
"Our study may [help mitigate] radiation risks when designing future Martian habitats using natural surface material as shielding protection," said Dr. Guo. "Research like this will therefore be of considerable value when mission planners begin considering designs for future Martian habitats that rely on natural surface material to provide radiation protection."
The paper that describes their findings recently appeared in the Journal of Geophysical Research.

Российские ученые синтезировали новый сверхжесткий материал на основе углеродных наноструктур фуллеренов с атомами скандия внутри. Подобные материалы могут использоваться в фотоэлектрических и оптических устройствах, нано- и оптоэлектронике, а также в биомедицинской инженерии в качестве высокоэффективных контрастных веществ.

Russian scientists have synthesized a new ultra-hard material consisting of scandium containing carbon. It consists of polymerized fullerene molecules with scandium and carbon atoms inside. The work paves the way for future studies of fullerene-based ultra-hard materials, making them a potential candidate for photovoltaic and optical devices, elements of nanoelectronics and optoelectronics, and biomedical engineering as high-performance contrast agents. The study was published in Carbon.
The discovery of new, all-carbon molecules known as fullerenes almost 40 years ago was a revolutionary breakthrough that paved the way for fullerene nanotechnology. Fullerenes have a spherical shape made of pentagons and hexagons that resembles a soccer ball, and a cavity within the carbon frame of fullerene molecules can accommodate a variety of atoms.
The introduction of metal atoms into carbon cages leads to the formation of endohedral metallofullerenes (EMF), which are technologically and scientifically important owing to their unique structures and optoelectronic properties.
A team of researchers from NUST MISIS, Technological Institute for Superhard and Novel Carbon Materials, and Kirensky Institute of Physics have obtained, for the first time, scandium-containing EMFs and studied the process of their polymerization. Polymerization is the process by which unbound molecules link together to form a chemically bonded polymerized material. Most polymerization reactions proceed at a faster rate under high pressure.
After the scandium-containing fullerenes were obtained from carbon condensate using a high-frequency arc discharge plasma, they were placed in a diamond anvil cell, the most versatile and popular device used to create very high pressures.
"We have found that guest atoms facilitate the polymerization process. Scandium atoms change the fullerene bonding process completely by the polarization of the carbon bonds, which leads to an increase in their chemical activity. The material obtained was less rigid than pristine polymerized fullerenes, it was easier to obtain," said Pavel Sorokin, senior researcher at the NUST MISIS Laboratory of Inorganic Nanomaterials.
The study will pave the way for studies of fullerite endohedral complexes as a macroscopic material and make it possible to consider EMF not only as a nanostructure of fundamental interest but also as a promising material that may be in demand in various fields of science and technology in the future, the researchers believe.

Исследователи Центра биоэлектрических интерфейсов НИУ ВШЭ разработали высокоточный алгоритм для обнаружения на электро- и магнитоэнцефалограмме маркеров эпилептической активности, так называемых межсудорожных спайков. Точная локализация эпилептогенных зон позволит повысить эффективность нейрохирургического вмешательства.

Researchers from the HSE University Centre for Bioelectric Interfaces have designed a new method for detecting diagnostic markers of epilepsy, called interictal spikes, using EEG and MEG. Capable of accounting for various errors and artifacts, this method constitutes a valuable addition to the arsenal of means for automatic analysis of electrophysiological recordings in epilepsy patients, especially when the data are noisy. Precise localization of epileptogenic cortical structures can enhance the effectiveness of neurosurgical interventions. The study is published in the Journal of Neural Engineering.
More than 65 million people worldwide suffer from epilepsy - which in 30% of cases is resistant to pharmacological treatment. Such patients can be helped by the neurosurgical removal of pathological cortical tissue in the epileptogenic zone. The main challenge for neurosurgeons is to localize this zone of about one square centimeter on the cortex area measuring up to 0.2 square meters. Epileptogenic zone localization can be facilitated by observing the brain's electrical activity to detect events such as interictal spikes, or spike-wave complexes.
Searching for interictal spikes among the multichannel signals reflecting the brain's electrical activity is a painstaking process that requires trained epileptologists to sift through a large amount of data using continuously evolving spike selection criteria. This is followed by analysis of the spike amplitude distribution over the scalp surface to localize the epileptogenic zone so that a neurosurgical intervention to remove this cortical area may be planned.
While automated signal processing and mathematical analysis can facilitate the search for interictal spikes, such automation requires the formalization of selection criteria applied by human operators.
A group of authors from the HSE University Centre for Bioelectric Interfaces and the Moscow University of Medicine and Dentistry named after I. A. Evdokimov developed a signal analysis technique for translating a verbal description of a spike's shape into a set of easily verifiable logical predicates.
"In a sense, our algorithm works like a human. Essentially, it helps the epileptologists to verify a set of verbally described spike shape parameters. The biomimetic approach used in our algorithm facilitates human-machine interaction and contributes to practitioner's trust in the results obtained by the automated analysis," explains Alexei Ossadtchi, Director of the Centre for Bioelectric Interfaces and head of the research team.
Having compared the algorithm's performance with a number of conventional methods, the authors found the former to be superior to several other well established approaches in processing datasets containing large amounts of high-amplitude artifacts.
"The algorithm's robustness - i.e. its ability to produce consistent results despite perturbations - can be particularly useful in dealing with clinical EEG data, which often contains high-amplitude artifacts, bursts and instabilities," comments the first author, Daria Kleeva, HSE University research assistant and a doctoral student at the Centre for Bioelectric Interfaces.

Ученые Уральского федерального университета и Института электрофизики УрО РАН разработали метод синтеза четырехкомпонентных нанокомпозитных покрытий, которые используются для защиты газотурбинных двигателей, в авиа- и машиностроении, металлообработке, биомедицине. Новый метод не требует высоких температур, дополнительного оборудования или материалов и позволяет получать покрытия с требуемыми характеристиками.

Scientists at the Ural Federal University (UrFU) and the Institute of Electrophysics of the Ural Branch of the Russian Academy of Sciences have developed a method for synthesizing four-component nanocomposite coatings. It is used to protect gas turbine engines, in aircraft and machine building, for metalworking, and in biomedicine. The new approach does not require high temperatures, additional equipment or materials, and allows to obtain coatings with the required characteristics. The experimental results and description of the method were published in the journal Membranes.
Nanocomposite coatings based on titanium, silicon, carbon, and nitrogen are promising for use as protective wear-resistant coatings due to their unique set of properties. Today such four-component coatings are synthesized using a number of physical and chemical methods, but they have disadvantages. And scientists have proposed the method of plasma chemical decomposition, which shows the best results in obtaining the final coatings.
"Compared to the vacuum-arc method, the advantage is the absence of microdroplets that degrade the quality of the coatings. Unlike magnetron sputtering, our method provides higher deposition rates, high ion flux density necessary to form dense and high-quality coatings. If you compare it with the chemical method, the advantage is the use of environmentally and health-friendly, affordable, and inexpensive components. The main advantage of the method, in our opinion, is the possibility to independently and within a wide range control almost all synthesis conditions, and, consequently, the composition and properties of the obtained coatings, which makes it possible to obtain films with the required characteristics," says Andrey Menshakov, researcher at the UrFU and at the Ural Branch of RAS.
The new method is relatively easy to implement: only a gas-discharge device with a hollow cathode and an active anode is used to create a multicomponent active medium. This deposition method does not require separate facilities and ionization and filtration systems because the flow of the evaporated metal does not contain any droplets that disturb the coating structure.
"The nanocomposite structure of such a coating is generally an amorphous matrix with nanocrystals embedded in it. To obtain multicomponent nanocomposite coatings, we use organosilicon precursors - volatile low-toxic liquids containing silicon-carbon and silicon-nitrogen bonds that participate in reactions leading to the formation of the final structure. To synthesize a nanocrystalline phase consisting of crystals titanium-nitrogen, titanium-carbon, or titanium-carbon-nitrogen, we add titanium to the precursor gas environment by its evaporation by electron flow from the plasma. Thus, we create an active vapor-gas environment consisting of the decomposition products of organosilicon molecules and titanium vapor, and the components of this mixture form a coating on the treated surface," explains Menshakov.
The researchers note that companies, which have the necessary production technology, are now creating installations for the application of such protective coatings for various enterprises. Using the new method can improve the energy efficiency of existing facilities, as well as the quality of the resulting films. When determining specific requirements for obtaining coatings, for example, on medical products or cutting tools, it is necessary to individually select synthesis conditions that will help to obtain coatings with the necessary characteristics. Now scientists are working on this very task of synthesizing coatings with the required mechanical and physical-chemical properties.

Томские и китайские ботаники расшифровали геном двух растений рода василисник (Thalictrum) семейства лютиковые (Ranunculaceae), обладающих антибактериальными, противоопухолевыми, заживляющими и другие полезными свойствами.

TSU laboratory Herbarium scientists, in collaboration with colleagues from China, have published an article on the Thalictrum genus, which has antibacterial and other healing properties. The article "Organization, phylogenetic marker exploitation and gene evolution in the plastome of Thalictrum (Ranunculaceae)" is published in Frontiers in Plant Science. The scientists have sequenced and analyzed the complete plastid genomes of two Thalictrum species (T. minus var. hypoleucum and T. simplex) using bioinformatics technologies.
"Next generation sequencing provides us with a large amount of data on plant genomes, proteomes, transcriptomes, etc. Numerical techniques to make sense of these data are provided by a newly emerging field of botany - plant bioinformatics. We used bioinformatics technologies to study the Thalictrum genus," says Andrey Erst, senior researcher at the TSU laboratory Herbarium and co-author of the article.
Thalictrum is one of the main genera in the buttercup family, Ranunculaceae, and includes more than 200 species. The plants of this genus are rich in alkaloid derivatives of benzylisoquinoline; most of them are highly biologically active. They are used in traditional medicine for curing various diseases - in Chinese traditional medicine it is used for treating enteritis and dysentery.
Thalictrum-based medications have antibacterial, antitumor, tonic, diuretic, laxative, and wound healing properties. Some species have been used as an antihypertensive drug. These plants also accumulate lithium, which plays an important role in regulating our nervous system. In addition to that, plants of the Thalictrum genus have been used as ornamental plants because of their lush foliage, elongated stems, and beautiful flowers.
"It’s a phylogenetically and economically important member of the family, but it is also considered one of the hardest plants in which to settle phylogenetic and taxonomic questions between taxons. We were able to identify plastome features that were mostly conserved in the overall structure of the gene order: a quadripartite structure, loci locations, and gene structure. We have also discovered eight highly variable noncoding genome regions. They can be used for a phylogeographic and taxon analysis of various species," says Andrey Erst.
The Russian-Chinese research team has also analyzed selective pressure and codon usage bias of all the plastid coding genes for 11 species. Phylogenetic relationships showed that Thalictrum is a monophyly and divided into two major clades. The availability of data on these plastomes offers valuable genetic information for accurate identification of species and taxonomy, phylogenetic resolution, and evolutionary studies of Thalictrum, and should assist in exploring and using Thalictrum plants.
The study is supported by the Russian Science Foundation (№ 19-74-10082).

Американские, российские и китайские исследователи получили новое синтетическое взрывчатое вещество, полученное с помощью химии высоких давлений и состоящее из двух атомов калия и шести атомов азота, образующих шестиугольное кольцо. Полученное соединение стабильно лишь при достаточно высоком давлении, поэтому следующий этап работы - стабилизация материала при нормальном давлении.

Une équipe internationale de scientifiques a fait une découverte qui pourrait entre autres révolutionner le stockage d’énergie ainsi que la propulsion de fusées. Il est question d’un matériau explosif de synthèse inédit obtenu par chimie à haute pression.
Un anneau de potassium et d’azote
En 2019, la NASA communiquait sur un budget faramineux qui devrait permettre de développer une fusée à propulsion nucléaire thermique. Pour l’agence spatiale américaine, l’objectif est de raccourcir les temps de trajets dans l’espace. Le domaine de la propulsion fait sans cesse l’objet de recherches et dernièrement, des scientifiques disent avoir inventé un explosif très puissant. Les détails de ces travaux figurent dans la revue Nature Chemistry du 21 avril 2022.
Alexander Goncharov est un mathématicien d’origine russe travaillant pour la Carnegie Institution à Washington (États-Unis). Avec d’autres chercheurs américains, mais également chinois et russes, il a mis au point un nouveau matériau explosif de synthèse dont la formule est K₂N₆. Ainsi, celui-ci se compose de deux atomes de potassium et six atomes d’azote, le tout formant un anneau.
Il faut savoir qu’habituellement, avec l’hydrogène et l’hélium, l’un des éléments générant souvent des explosions est l’azote. Or, l’azote se retrouve dans de très nombreux explosifs chimiques comme la poudre à canon et le TNT.
Pas encore de forme permettant une application pratique
L’explosion se produit suite à la formation de liaisons chimiques. En effet, l’atome d’azote (voir schéma) contient trois électrons non appariés et lorsque deux atomes d’azote se rencontrent, ils forment le gaz connu sous le nom de diazote (N₂) qui génère de l’énergie. Bien que l’azote soit abondant dans l’atmosphère terrestre, l’attraction est si forte entre les atomes qu’ils ne rencontrent pas les autres éléments et se contentent généralement de flotter. En revanche, lorsque la pression est plus importante que la normale, leur explosivité se révèle.
Pour créer leur nouvel explosif, les scientifiques ont porté un précurseur d’azote contenant du potassium à environ 450 000 fois la pression atmosphérique. Il a ensuite été chauffé à l’aide de puissants lasers infrarouges afin d’obtenir la synthèse d’un composé inédit. Le K₂N₆ est un matériau cristallin à l’éclat métallique, se composant de plusieurs anneaux d’azote pur en forme d’hexagone. Ces anneaux sont stables grâce à la présence de potassium s’intercalant entre chacun d’entre eux. Toutefois, les chercheurs expliquent que le matériau en question est stable sous des pressions environ 50 % moins fortes que celle effective lors de sa création.
Autrement dit, il n’existe pas encore de forme permettant une application pratique. La prochaine étape pour les scientifiques sera donc de trouver le moyen de maintenir le matériau stable à une pression normale, c’est-à-dire la pression atmosphérique. En cas d’évolution positive des travaux, il pourrait s’agir d’une véritable révolution dans le stockage de l’énergie ainsi que les matériaux propulseurs, notamment de fusées.

Уральские палеонтологи обнаружили в пещере Таврида челюсти очень редкого этрусского медведя, обитавшего в раннем плейстоцене (1,5-2 млн лет назад), а также останки других крупных хищников. Это расширяет географию обитания медведя, а также позволяет предположить, что в то время в Крыму уже жили предки современных людей, мигрировавшие в Евразию вслед за представителями крупной наземной фауны.

A group of paleontologists, included researchers from the Ural Federal University (UrFU), discovered the jaws of an Etruscan bear from the early Pleistocene period (2-1.5 million years ago) in the Taurida cave. The remains of Etruscan bears (which is the ancestor of brown and cave bears) as part of the fauna of large mammals of the early Pleistocene were found in Western Europe, Asia, and North Africa. And now it is found in the Crimea. The bones indicate that the ancestor of modern man, the early Homo, most likely lived on the territory of the Crimean Peninsula almost 2 million years ago. The discovery was reported in the paleobiology journal Historical Biology.
"Our finding, on the one hand, extends the geography of distribution of the Etruscan bear in Eastern Europe, and on the other hand, it indicates that the "Crimean" bear is a link between Asian and European relatives. On the third hand, it helps to characterize the evolutionary features within the bears and the historical biogeography of this species," said Dmitry Gimranov, senior researcher at the Laboratory of Natural Science Methods in the Humanities at UrFU.
Excavations by paleontologists were carried out in 2020-2021. The remains were found in the pre-surface layer of deposits of Taurida, in a small chamber called the "Hyena Den". As a result of the research, it was established the features of life and the fact that the Etruscan bear coexisted next to such large predators as lynxes, giant hyenas, saber-toothed cats, wolves, with whom it had to compete for food resources just as it probably did with humans.
"More than 2 million years ago, together with the fauna of that time - antelopes, bulls, elephants, hyenas, Etruscan bears - the ancient man Homo moved towards Eurasia," says Dmitry Gimranov. "As a rule, the presence of members of these faunas in the territories of Western Europe correlates with the presence of ancient Homo. The remains of ancient people have not yet been found in Taurida, most likely they were there, we just haven’t found them yet. But the structure of the Taurida's fauna - Etruscan bear, saber-toothed tigers, hyenas and other large mammals - suggests that at that time the migration routes of ancient people could pass through this territory."
The Etruscan bear was a typical representative of European faunas during the early Homo period, scientists believe. They concluded by comparing finds from the Taurida cave and its closest point with the same fauna of the same age Dmanisi (Georgia), where the earliest Eurasian Homo remains were found.
At the next stage of the work, paleontologists plan to study the food habits and ecological characteristics of the Etruscan bears. This will help to understand how they competed for food resources with other large predators.
Note
The Taurida Cave was discovered in Crimea in 2018. It is located 15 km east of Simferopol on the Inner Ridge of the Crimean Mountains. The bone layer of the cave corresponds to the fauna of Eastern Europe and the late Villafranchian of Western Europe (about 1.8-1.5 Ma). Taurida is rich in bones of early Pleistocene mammals. During two seasons of excavations, paleontologists found there the remains of the Issuar lynx, the skull of the giant hyena Pachycrocuta, and the bones of other ancient animals.

Экспедиция Всероссийского научно-исследовательского института рыбного хозяйства и океанографии и Лимнологического института СО РАН намерена выяснить, каким образом байкальский омуль пелагической (селенгинской) популяции в последние годы резко прибавил в размерах и вместо 300-350 граммов весит теперь 600-800 граммов.

The Baikal omul of the pelagic (Selenga) family, a subspecies of salmon, have almost doubled in size, head of the Baikal branch of the All-Russian Research Institute of Fisheries and Oceanography (VNIRO) Vladimir Peterfeld told TASS.
Since October 2017, a ban has been established on industrial Industrial and amateur fishing of omul in lake Baikal, Russia, due to a sharp decline in its population. The Baikal omul is the object of one of the largest commercial fisheries on Lake Baikal, as well as the most well known example of the fauna that lives exclusively in the lake.
With some restrictions, omul can be caught by the indigenous peoples of Siberia and fish hatcheries for artificial reproduction purposes, as well as be taken by scientists and for research.
"In recent years, we have recorded the highest growth rate of pelagic omul in history. That is, such a large omul has never come to spawn. This is most pronounced growth in the pelagic group. If, for example, in 1985 there were three omuls of 300-350 grams in a kilogram, now the same omul are almost 600-800 grams each," Peterfeld said.
Scientists do not yet understand what is causing the unusual growth, specialists from VNIRO and the Limnological Institute of the Siberian Branch of the Russian Academy of Sciences are planning a six-day expedition which, will depart at May 23, to further research what is causing the growth anomaly among other subjects.
"During the expedition, we will calculate not only the biomass, but also the size characteristics of the fish in order to understand how many juveniles and adults we have," Andrey Fedotov, director of the Limnological Institute, said in a statement. "One of the types of analysis that will be performed during this expedition is the composition of microelements in the tissues of the omul."
Researchers plan to find out how and at what depths the Baikal omul is distributed in winter, Peterfeld told TASS.
Deep ice fishing has recently become popular on Lake Baikal, when fish were caught with bait from a depth of 150-200 meters using this method. It turns out that fauna that is active at such depths is not in winter hibernation, as researchers previously thought.

Земля Бунге расположена на архипелаге Новосибирские острова и представляет собой ровную песчаную пустыню, неожиданную в этих широтах. Среди геологов до сих пор нет единого мнения о времени и причинах ее появления. Изучение арктической пустыни затрудняют ее удаленность и неблагоприятный климат, а вскоре Земля Бунге и вовсе может оказаться под водой из-за климатических изменений и подъема уровня моря.

You would be forgiven for expecting camels, or an oasis, maybe. In full summer sun, the vast, flat stretch of pale sand is nearly featureless, broken in places only by what appear to be low dunes, or perhaps the dry beds of ancient rivers. It might be mistaken for the Sahara, or the Arabian Peninsula’s famous Empty Quarter, also known as Rub’ al Khali, the largest continuous sand desert on the planet. But this is Bunge Land, Zemlya Bunge in Russian, a 2,400-square-mile desert north of the Arctic Circle. And no one is entirely sure how it got there.
"Currently, there is no consensus among geologists," says Andrei Prokopiev, a geologist with the Russian Academy of Sciences who has done fieldwork on the New Siberian archipelago, where Bunge Land is located. With some understatement, he adds, "There are different points of view."
Bunge Land remains a question mark because its remote location and inhospitable climate make it difficult to study, and because the underlying geology of the area is particularly complex. The clock may be running out on our chance to figure out this mysterious landform. As climate change intensifies, so do the spring and summer storms that periodically flood much of this Arctic desert with seawater. Rising sea levels may soon claim Bunge Land for good.
For now, Bunge Land sits roughly in the center of the New Siberian Islands, which are scattered several miles off Russia’s northern coast, where the Laptev and East Siberian Seas meet. The rugged archipelago is home to Arctic fox, lemmings, and, in summer, migratory birds - but not much else. The rest of the New Siberians are tundra-topped layer cakes of permafrost that’s now thawing. As the compressed layers of ice and once-frozen soil melt, the islands’ dark and ragged coastlines slump, chunk by chunk, into the frigid water. But not on Bunge Land.
Wedged between two of the larger islands, Kotelny and Faddeyevsky, Bunge stands in stark contrast. While Kotelny has a range of modest mountains reaching about 1,200 feet in elevation and Faddeyevsky tops 200 feet in places, most of Bunge Land is less than 20 feet above sea level. In fact, the earliest recorded explorers of the region, in the late-18th and 19th centuries, missed Bunge Land entirely.
"The first travelers came there by ice when only Kotelny and Faddeyevsky were visible," says geologist Alexander Kuzmichev, also at the Russian Academy of Sciences. Kuzmichev knows firsthand that missing the vast Arctic desert between the two islands is easy to do. "I have been on Bunge Land only once, in early June," he says. "The sea was under ice, the land under snow, and there was no definite border between."
When people finally did notice this strange place, they named it after scientist Alexander von Bunge, who had led an expedition in the New Siberians in 1886. Noticed and named at last, Bunge Land presented another challenge: figuring out what it was and when it formed. And that’s where things get complicated.
Let’s start with what to call it. The Eastern Arctic Seas Encyclopedia and other reference guides define Bunge Land as "an island and a sandbank." Geologists who study it, however, call it a land bridge or intermediate zone and, increasingly, define Kotelny as a single island that includes both Bunge Land and Faddeyevsky.
For most of the 20th century, scientists - when they thought about the remote desert at all - thought Bunge Land was a block of sandy seafloor somehow shoved up and exposed. At first glance, that seems plausible. On a satellite image of Bunge Land and its neighbors, in addition to the contrast of its pale sands, something else stands out: The dividing lines between Bunge and the land on either side of it are fairly sharp, a clue that they are faults, carved by past seismic activity.
"You can already see from the geomorphology of the three parts of the whole Kotelny Island that there are very straight borders between them. This always shows a strong, large-scale tectonic shaping," says geologist Lutz Schirrmeister, senior researcher at the Alfred Wegener Institute in Bremerhaven, Germany. In 2010, Schirrmeister coauthored the most comprehensive paper to date on Bunge Land, in the journal Quaternary Science Reviews.
In fact, the entire New Siberian archipelago falls within the active Arctic Rift Zone, where the Eurasian and North American tectonic plates are slowly and unevenly pulling apart deep below the surface, rumpling and stretching and tearing whatever is above them. Schirrmeister’s research, however, shows that at least large areas of Bunge Land were not raised from the seafloor. These areas are terrestrial in origin, and "part of the East Siberian (continental) shelf."
During the Last Glacial Maximum (LGM), or the height of the last ice age more than 15,000 years ago, Schirrmeister says, "the global sea level was about 120 meters [roughly 400 feet] lower, because quite a lot of water was bound in the ice caps, [and] these areas belonged to the mainland." As the ice caps melted, the region, which was not entirely covered in ice, gradually flooded, with the present coastline established about 5,000 years ago, he says.
While ongoing tectonic activity has certainly played a role in the shape of these landforms, the loss of the ice sheets also had a hand. The immense weight of miles-high ice during the LGM actually depressed Earth’s surface. As the ice melted, that intense pressure dissipated and the surface essentially bounced back - very slowly, over millennia - in a process known as isostatic rebound. In some more accessible areas of the Northern Hemisphere that were once crushed by ice sheets, particularly in Alaska and Canada, scientists have found that the rebound process continues today. It’s possible the New Siberians are also still rebounding, but research in this area has been limited.
In the 21st century, Schirrmeister’s team and others have confirmed areas of thermokarst, a type of landscape unique to permafrost regions, buried beneath the sands that dominate Bunge Land’s expanse. Thermokarst regions are flat and pockmarked with small depressions, formed over time as permafrost melts and freezes again - and they don’t form on seabed.
Instead of Bunge Land being sandy seafloor pushed upward by tectonic activity, it appears to have been a permafrost landscape that, because it sits at a lower elevation, was buried under layer after layer of sand, which arrived courtesy of the area’s extreme winds and intense storms. The sand didn’t simply wash away because it was hemmed in by the higher ground on either side. There are additional hints that the permafrost itself also may have slumped during a melt event, been inundated by seawater, and then was lifted again by the restless planet’s tectonic to and fro. The exact order of events, and the timing, remains a mystery.
Evgeny Gusev, deputy director general of geological mapping at VNIIOkeangeologiya, a marine geology research institute based in St. Petersburg, believes in a recent and tectonic origin for Bunge Land. "There was a general tectonic rise of the entire archipelago," says Gusev. "This happened, apparently, in the middle Holocene, 3,000 to 5,000 years ago."
Other geologists remain skeptical. "No tectonic activity is responsible," says Kuzmichev, who thinks isostatic rebound alone explains the rise of Bunge Land and surrounding parts of the continental shelf following the most recent ice age.
Kuzmichev and some other geologists, including Prokopiev, believe the faults that separate Bunge Land from its immediate neighbors date back more than 2.6 million years, possibly much earlier, and are not related to Bunge Land’s recent (geologically speaking) appearance.
However Bunge Land formed, it’s very possible that humans witnessed it. During the last ice age, when sea levels were lower, the entire region was part of a massive plain that spanned continents and included the land bridge of Beringia, which ancient Siberians crossed into what’s now North America. And, while no artifacts have been found on Bunge Land itself, archaeologists have uncovered extensive evidence of an ancient human presence on Zhokhov Island, about 200 miles to the northeast. What humans in the area may have thought of this anomalous, sandy expanse, however - along with the exact events that created it - remains unknown.

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