Июнь 2024 г.

Российская наука и мир (по материалам зарубежной электронной прессы)

CONTENTS / ОГЛАВЛЕНИЕ


• Rosatom announces novel used fuel processing technology
• Non, l'Europe n'a pas été conquise par des cavaliers il y a 5000 ans : la domestication du cheval est bien plus tardive
• Scientists propose converting natural gas into hydrogen directly in gas fields
• As leaks on the space station worsen, there’s no clear plan to deal with them
• Chemists offer new type of contrast agent for magnetic resonance imaging
• Un "cimetière" de mammouths révèle 800 ans d'interactions entre les humains et l'animal en Sibérie
• Squeezing Schrödinger's cat may increase quantum sensitivity
• Medieval carving of a warrior discovered in Russia
• Russian researchers develop accident-tolerant fuel using digital twin
• Amazingly-preserved ancient wolf with its fearsome teeth intact after 44,000 years is pulled out of Siberian permafrost
• Did inbreeding cause the woolly mammoth’s extinction? Our research suggests it was more sudden than that
• The beginnings of fashion: why do we wear clothes?

Росатом объявил о разработке инновационной технологии очистки и выделения ядерных материалов из отработанного ядерного топлива. Технология кристаллизационного аффинажа станет заключительным этапом очистки и обеспечит высокий уровень безопасности процесса.

Rosatom said that scientists from its Fuel Division and the Proryv, or Breakthrough, project area have developed the new technology, which will be implemented at the facility for reprocessing irradiated uranium-plutonium (SNUP) fuel as part of the pilot energy complex (ODEK) being built at the Siberian Chemical Combine's site in Seversk, Tomsk Region.
Rosatom's Proryv project aims to enable a closed nuclear fuel cycle, ultimately eliminating production of radioactive waste from nuclear power generation. The ODEK complex comprises a fuel production/refabrication module for production of dense uranium plutonium (nitride) fuel for fast reactors; a nuclear power plant with a BREST-OD-300 lead-cooled fast-neutron reactor; and a used fuel retreatment module.
The crystallisation technology is expected to become the final technological stage in the process of purification of nuclear materials isolated from irradiated SNUP fuel - uranium, plutonium and neptunium, the company said.
"Crystallisation refining technology will ensure a high level of safety during used nuclear fuel reprocessing," Rosatom said. "The technological process will make it possible to jointly purify and isolate uranium, plutonium and neptunium, eliminating the possibility of isolating plutonium as a separate product. Thus, the technology fully complies with the nuclear non-proliferation regime."
It noted that, unlike extraction technologies for purification of nuclear materials, crystallisation is accompanied by the production of a smaller volume of secondary waste, including due to the use of only nitric acid solutions as reagents. "This technology will improve the environmental safety of the used fuel reprocessing process," Rosatom said.
Technologies for reprocessing irradiated fuel are of particular importance for closing the nuclear fuel cycle at ODEK, the company noted. Materials separated from used fuel, after reprocessing, will be sent for fabrication of fresh fuel. "Thus, this system will gradually become practically autonomous and independent of external energy supplies," Rosatom said.

Единого мнения о том, где и когда впервые были одомашенены лошади, среди ученых пока нет. Исследовав ДНК 475 древних лошадей и 77 современных, команда палеогенетиков из 27 стран, в том числе России, пришла к выводу, что случилось это не ранее 4200 лет назад в Понтийско-Каспийской степи.

Oubliez les hordes de cavaliers des steppes déferlants sur l’Europe, il y a 5000 ans. S’il y a eu de nouveaux arrivants, ils sont venu certainement à pied. Et pour cause : la domestication du cheval n’a que 4200 ans. C'est ce que montre une étude d’ADN dirigée par Ludovic Orlando du Centre d’anthropobiologie et de génomique de Toulouse (CNRS et université Toulouse III - Paul Sabatier). Cette enquête a employé 133 scientifiques de 113 institutions ; elle parait ce 6 juin 2024 dans la revue Nature.
L’essor des chevaux domestiques n’a commencé qu’il y a environ 4200 ans
Qu'ils soient champions de saut ou haridelles "tous les chevaux domestiques vivant sur terre trouvent leurs origines dans les steppes occidentales de Russie", précise le CNRS dans un communiqué, "mais la chronologie exacte de leur intégration généralisée dans les sociétés humaines divisait encore la communauté scientifique". Le dernier résultat montre que l’essor des chevaux domestiques n’a commencé qu’il y a 4200 ans environ.
Cette date a marqué une nouvelle ère dans l'histoire humaine, les chevaux révolutionnant la vitesse des échanges (conquête, razzia, commerce, etc.) entre les peuples. Sa prolifération soudaine dans l’Eurasie tout entière a été permise grâce à l’émergence de techniques efficaces contrôlant la reproduction du cheval. D'autres étaient apparues un peu plus tôt mais n'avaient pas entraîné la multiplication de l'animal dans les steppes d’Asie Centrale.
Une fois domestiqués et montés, la demande de chevaux a été exponentielle à travers le continent
Les experts se sont appuyés sur une vaste collection de restes archéologiques de chevaux couvrant l'Eurasie tout entière. Les techniques de pointes et le séquençage de l'ADN ancien leur a permis "d'analyser les transformations génétiques qui ont accompagné l'émergence de l'équitation avec une précision inégalée, et y retrouver le moment où l'élevage du cheval a débuté" précise le CNRS.
Les scientifiques "ont tout d’abord cherché à placer précisément dans le temps l’époque où les ancêtres des chevaux domestiques actuels ont commencé à quitter leur foyer d’origine. Ensuite, ils ont reconstruit l’histoire démographique des chevaux pour identifier quand les éleveurs ont entrepris de les produire à grande échelle. Enfin, ils ont cherché des signes génétiques manifestes d’une manipulation délibérée de la reproduction animale par les premiers éleveurs."
"Ces trois indices (date du début de l’essor des chevaux domestiques ; démographie ; manipulation de la reproduction) dépeignent tous une histoire cohérente où les chevaux domestiques ont été produits en nombre suffisant pour répondre à une demande exponentielle à travers le continent, démarrant il y a seulement 4200 ans", estiment les spécialistes dans Nature.
Par conséquent, cette date, et aucune autre avant elle, marque le début d’une nouvelle ère dans l’histoire humaine où la mobilité basée sur le cheval a émergé pour rester un élément central de nos sociétés... jusqu’à l’essor des moteurs à combustion à partir de la fin du XIXe siècle.
Le cheval a été conquis deux fois : pour être mangé, puis pour être monté
Des travaux précédents sur l'ADN ancien préservé dans des restes humains avaient pourtant révélé que le paysage génétique de l’Europe avait connu un changement radical suite à la migration de peuples venus des steppes, souvent décrits comme cavaliers et locuteurs d’une langue proto-indo-européenne.
La nouvelle étude ne retrouve aucun signe de tels bouleversements parmi les chevaux de la même époque. Ainsi, et malgré l’omniprésence d’un vocabulaire lié au cheval parmi les langues indo-européennes, les humains ne se sont pas servi du cheval comme moyen de transport au cours de ces migrations !
"Les travaux publiés aujourd’hui décrivent une méthode particulièrement innovante permettant d’établir que les générations de chevaux se sont mises à défiler bien plus vite au moment même où leur production devenait massive et où ils envahissaient le continent" se réjouit le CNRS. "Si les premiers éleveurs ont donc pu produire soudainement un nombre aussi colossal de chevaux pour répondre à une demande devenue générale, c’est qu’ils ont réussi à élever et à faire se reproduire des chevaux de plus en plus jeunes, jusqu’à presque doubler leur capacité de production".
Selon Nature, l'équipe de recherche a retrouvé les mêmes signes d’une accélération considérable dans la cadence des générations au sein d’une lignée distincte de celle menant aux chevaux domestiques modernes. Cette lignée a été découverte à Botaï, un site d’Asie centrale où des enclos à chevaux et des signes de leur traite et de leur harnachement ont été décrits, mais sont restés fortement débattus.
Le nouvel indice génétique dévoilé par l’étude plaide en faveur d’un contrôle avancé de la reproduction des chevaux par les éleveurs. Il conforte les interprétations faisant du peuple sédentaire de Botaï un peuple ayant réussi à domestiquer le cheval il y a 5500 ans pour en exploiter sa viande et son lait. Le cheval a donc bel et bien été domestiqué deux fois : d’abord pour le manger, et bien longtemps après, pour le monter.

Ученые Сколтеха предложили получать водород из природного газа прямо в газовых месторождениях. В скважину закачивается водяной пар, катализатор и кислород для воспламенения. С помощью катализатора при сжигании газа образуется смесь окиси углерода (угарного газа) и водорода, после чего последний выводится из скважины через мембрану, не пропускающую другие продукты горения.

Skoltech researchers have found a way to produce hydrogen from natural gas with 45% efficiency right in the gas field by injecting steam and a catalyst into a well and adding oxygen to ignite the gas. Catalyst-assisted combustion produces a mixture of carbon monoxide and hydrogen, from which the latter can be easily extracted. This technology will help accelerate the transition from fossil fuels to clean hydrogen power. The study supported by a grant from the Russian Science Foundation (RSF) was published in Fuel.
Approximately 80 percent of energy comes from fossil fuels, such as oil and natural gas, which release carbon dioxide when burned, threatening the environment and contributing to climate change. Although gas is considered "cleaner" than oil with its many toxins, it still emits carbon dioxide when burned, making gas a threat to the environment. Hydrogen, which emits nothing but water vapor, could be a healthier alternative. However, the widespread use of this "green" energy source is hampered by production difficulties.
For the first time, a team from the Skolkovo Institute of Science and Technology in Moscow has proposed extracting hydrogen from the reservoirs of natural gas fields, which are rich in hydrocarbons that contain a large amount of hydrogen at the molecular level. This means that hydrocarbons, once converted, can yield an abundance of "green" fuel.
The team has proposed an efficient, multi-step process for producing hydrogen from gas fields. First, steam is injected into the well along with a catalyst that will later help separate hydrogen from the natural gas components. Then, air or pure oxygen is pumped in to ignite the gas directly in the reservoir. Assisted by the steam and catalyst, the natural gas burns and is converted into a mixture of carbon monoxide and hydrogen. The carbon dioxide formed from the carbon monoxide remains in the reservoir and does not contribute to the greenhouse effect. At the final stage, hydrogen is extracted from the well through a membrane that blocks other combustion products, leaving the carbon monoxide and carbon dioxide permanently trapped underground.
The researchers tested their process in lab reactors that simulated a real gas reservoir environment. They placed crushed rock in the reactor and then pumped in methane, the main component of natural gas, along with steam and a catalyst, and then oxygen. The pressure inside the reactor was maintained at a level typical of gas reservoirs (eighty times higher than atmospheric pressure).
As the experiment progressed, the team analyzed the composition of the gases in the reactor to assess the efficiency of the methane conversion into hydrogen. It turned out that most of the hydrogen - 45% of the total gas volume - was formed at 800° C with large amounts of steam injected into the reactor. To make the reaction as efficient as possible, there should be four times more steam than natural gas. The researchers chose the 800° C temperature because it is easily achieved in natural gas combustion and does not need to be artificially maintained.
The hydrogen yield also depended on the composition of the rock. For example, in experiments with porous alumina, the hydrogen yield reached 55 percent. The higher efficiency in this case is explained by the fact that alumina is inert, i.e. it does not react with the surrounding elements. Natural rock contains other, more active minerals that can react with the components of the gas mixture and affect the hydrogen yield.
"All the stages of the process are based on well-established technologies that have not previously been adapted for hydrogen production from real gas reservoirs. We have demonstrated that our approach can help convert hydrocarbons into "green" fuels in the field environment with an efficiency of up to 45%. In the future, we plan to test our method in real gas fields," says Elena Mukhina, PhD, a senior research scientist at Skoltech Petroleum and the leader of the RSF-supported project.

НАСА и Роскосмос не могут решить проблему с утечками воздуха на Международной космической станции. На протяжении нескольких лет трещины периодически обнаруживаются в промежуточной камере российского модуля «Звезда», а в феврале этого года утечка усилилась в два раза. Ни одна из принятых мер не сработала, поэтому в апреле Роскосмос решил держать люк в отсеке, из которого утекает воздух, постоянно закрытым и открывать только при прибытии грузового корабля.

NASA and the Russian space agency, Roscosmos, still have not solved a long-running and worsening problem with leaks on the International Space Station.
The microscopic structural cracks are located inside the small PrK module on the Russian segment of the space station, which lies between a Progress spacecraft airlock and the Zvezda module. After the leak rate doubled early this year during a two-week period, the Russians experimented with keeping the hatch leading to the PrK module closed intermittently and performed other investigations. But none of these measures taken during the spring worked.
"Following leak troubleshooting activities in April of 2024, Roscosmos has elected to keep the hatch between Zvezda and Progress closed when it is not needed for cargo operations," a NASA spokesperson told Ars. "Roscosmos continues to limit operations in the area and, when required for use, implements measures to minimize the risk to the International Space Station."
What are the real risks?
NASA officials have downplayed the severity of the leak risks publicly and in meetings with external stakeholders of the International Space Station. And they presently do not pose an existential risk to the space station. In a worst-case scenario of a structural failure, Russia could permanently close the hatch leading to the PrK module and rely on a separate docking port for Progress supply missions.
However, there appears to be rising concern in the ISS program at NASA's Johnson Space Center in Houston. The space agency often uses a 5x5 "risk matrix" to classify the likelihood and consequence of risks to spaceflight activities, and the Russian leaks are now classified as a "5" both in terms of high likelihood and high consequence. Their potential for "catastrophic failure" is discussed in meetings.
US officials are likely remaining quiet about their concerns because they don't want to embarrass their Russian partners. The working relationship has improved since the sacking of the pugnacious leader of Russia's space activities, Dmitry Rogozin, two years ago. The current leadership of Roscosmos has maintained a cordial relationship with NASA despite the high geopolitical tensions between Russia and the United States.
The leaks are a sensitive subject. Because of Russian war efforts, the resources available to the country's civil space program will remain flat or even decrease in the coming years. A dedicated core of Russian officials who value the International Space Station partnership are striving to "make do" with the resources they have to maintain its Soyuz and Progress spacecraft, which carry crew and cargo to the space station respectively, and its infrastructure on the station. But they do not have the ability to make major new investments, so they're left with patching things together as best they can.
Aging infrastructure
At the same time, the space station is aging. The Zvezda module was launched nearly a quarter of a century ago, in July 2000, on a Russian Proton rocket. The cracking issue first appeared in 2019 and has continued to worsen since then. Its cause is unknown.
"They have repaired multiple leak locations, but additional leak locations remain," the NASA spokesperson said. "Roscosmos has yet to identify the cracks’ root cause, making it challenging to analyze or predict future crack formation and growth."
NASA and Russia have managed to maintain the space station partnership since Russia's invasion of Ukraine in February 2022. The large US segment is dependent on the Russian segment for propulsion to maintain the station's altitude and maneuver to avoid debris. Since the invasion, the United States could have taken overt steps to mitigate against this, such as funding the development of its own propulsion module or increasing the budget for building new commercial space stations to maintain a presence in low-Earth orbit.
Instead, senior NASA officials chose to stay the course and work with Russia for as long as possible to maintain the fragile partnership and fly the aging but venerable International Space Station. It remains to be seen whether cracks - structural, diplomatic, or otherwise - will rupture this effort prior to the station's anticipated retirement date of 2030.

Казанские химики предложили новый тип контрастного вещества для магнитно-резонансной томографии - наночастицы бычьего сывороточного альбумина в сочетании с ионами марганца. Последний, в отличие от применяемого сейчас гадолиния, более биосовместим и не имеет токсического эффекта.

Scientists at the Institute of Chemistry have developed a new type of contrast agent for magnetic resonance imaging (MRI) - bovine serum albumin nanoparticles doped with manganese (II) ions. The results of the study are published in International Journal of Biological Macromolecules.
The extensive research, supported by a grant from the Russian Science Foundation, was carried out by researchers: Associate Professors Rustem Zairov and Timur Mukhametzyanov of the Department of Physical Chemistry, Senior Researcher Bulat Akhmadeev of the Laboratory of Materials for Hydrogen Energy and Conventional Energy with Low Carbon Footprint, Lab Researcher Alexey Dovzhenko, and junior researchers Timur Kornev, a second-year Ph.D. student, and Vadim Vasilyev, a fourth-year student. The research group also included scientists from Kazan National Research Technological University, Kazan National Research Technical University, and the Institute of Organic and Physical Chemistry of the Kazan Scientific Center of the Russian Academy of Sciences.
The use of biomolecules in the development of nanomaterials is a well-known way to increase its biocompatibility. Blood proteins are the most common biological objects of study, as they have a unique ability to bind and transfer various substrates, including metal ions. Due to controlled soft denaturation, the properties of native, i.e. original proteins can be dramatically changed. In the case of this development, the protein in question is bovine serum albumin (BSA), which is a more accessible model of human serum albumin (HSA). Modification of the properties of protein molecules and further cross-linking with certain cross-linking agents allows to fix the obtained functional characteristics and synthesize nanoparticles.
"Bovine serum albumin is a classical protein that is the closest and most actively investigated model of human serum albumin. The primary function of this protein in the human body is transport - it reversibly binds various biomolecules and transports them. BSA is the most commercially available protein, its cost relative to other proteins is low, so many biological studies that claim for further application in biomedical purposes are conducted on bovine serum albumin. We found that bovine serum albumin in its native (initial) state is able to bind manganese ions in a ratio of 1:1. In this case, the formed complex, in which the manganese ion (Mn2+) is bound, say, with a high molecular weight ligand, is able to increase the relaxation of water protons by several orders of magnitude. By selecting experimental conditions by desolvation with an organic solvent, we achieved a mild non-thermal denaturation of the protein," comments Rustem Zairov.
In the denatured state the protein is able to bind 4 manganese ions, Zairov notes. Thus, it becomes possible to increase manganese loading by 4 times. Further, by adding glutaric aldehyde, the scientists cross-linked denatured protein molecules to form nanoparticles. Such particles, says the Associate Professor, have a size of about 100 nanometers, which is very suitable for biomedical applications - they are able to cross various barriers in the body.
The participants of the study achieved a ratio of Mn2+ ions to protein - 4:1, studied the magnetic relaxation characteristics and showed that the particles are very biocompatible, by the type of Fenton reaction they have a very weak catalytic activity. They are characterized by low hemolytic activity and hemagglutination (at concentrations less than 110 micromol/L). Scientists are confident such nanoparticles are promising candidates for use as contrast agents in MRI scans; they exhibit unusually high relaxivity values compared to other manganese particles at the 100-unit level (longitudinal relaxivity, 98.9 mM-1s-1; transverse relaxivity, 133.6 mM-1s-1).
"As you know, more than 30 percent of modern MRI procedures are performed with the administration of contrast agents. It is clear that MRI is by far the most widely used method for non-invasive diagnosis of tumor diseases. In some cases, contrast injection is required to locate the tumor site, including cancerous tumors, for highly accurate diagnosis. For this purpose, contrast agents are injected, all of which are complex compounds of gadolinium (Gd). Gd3+ is such an ion, which has seven unpaired electrons, and due to its unique magnetic properties, it effectively accelerates the relaxation of water protons," says Zairov.
The scientist adds that unlike manganese, which is found in the human body, gadolinium can cause nephrotoxicity - toxicity towards the kidneys leading to nephrogenic systemic fibrosis as well as some neurodegenerative diseases.
"The question is now increasingly being raised that gadolinium needs to be replaced with something more 'bio-friendly', and this is where Mn2+ comes in. This ion has an electronic configuration d5, the number of unpaired electrons, it is inferior to gadolinium: the relaxivity of the manganese(II) aqua ion is slightly lower than the relaxivity of the gadolinium(III) aqua ion (9 and 16, respectively). Despite this, in a certain ligand environment or in the composition of nanoparticles, the use of manganese may give a better result," explains the scientist. "Existing MRI contrast agents are not so effective, at least their relaxivity values lie in the range of 3.5 - 9.9. The relaxivity of nanoparticles obtained by our group reaches about 100 units. This is a significant breakthrough in the field of contrast agent development, as it exceeds the corresponding relaxivity values of current, commercially available MRI contrast agents based on gadolinium by more than an order of magnitude. That is, with manganese, which initially loses to gadolinium but is more biocompatible, we were able to achieve higher relaxivity. At the same time, together with biologists, it was shown that the resulting nanoparticles do not cause toxic effects, hemagglutination and do not generate reactive oxygen species."
The research was conducted under the supervision of Marat Ziganshin, Director of the Institute of Chemistry, and Asiya Mustafina, Head of the Laboratory of Physical Chemistry of Supramolecular Systems at the Institute of Organic and Physical Chemistry.
In the near future, the technology may be used in biomedicine to establish contrast between healthy and diseased tissues during diagnostics using magnetic resonance imaging.

Берелехское кладбище мамонтов в Якутии - скопление останков нескольких сотен животных возрастом 12-14 тысяч лет - расположено по соседству со стоянкой древнего человека, относящейся к тому же периоду. Долгое время считалось, что кладбище возникло естественным путем - в долину реки Берелех кости приносило водой, либо же мамонты по какой-то причине массово гибли на месте. Новое исследование российских палеонтологов опровергает это мнение, показывая, что накопление костных останков непосредственно связано с присутствием в этом районе людей и началось с возникновением поселения.

Une récente étude montre que l'accumulation d'os de mammouths laineux le long d'une rivière sibérienne, datant de temps où la Terre était plongée dans une ère glaciaire, a été créée par d'anciennes communautés humaines, utilisant le site comme une sorte "d'usine de transformation" de l'ivoire.
Le long de la rivière Berelekh, dans l'Arctique sibérien oriental en Russie, ont été découverts les restes d'un "cimetière" de mammouths : des milliers d'os désarticulés de ces pachydermes laineux (Mammuthus primigenius), d'au moins 156 spécimens ont été retrouvés près d'un site archéologique. Cette proximité a conduit les chercheurs à penser qu'il y a plusieurs milliers d'années, un lien étroit existait entre les communautés vivant au-delà du 70e parallèle nord, animales et humaines.
La manière dont ces deux dernières ont interagi est l'objet de nouvelles recherches, publiées dans les Quaternary Science Reviews le 15 juin 2024. Et elles révèlent en effet que durant les cycles glaciaires Pléistocène, les anciennes communautés humaines ont, sur 700 à 800 ans et pour fabriquer artisanalement (et en grande quantité) des outils, des armes ou des objets en ivoire, amasser de nombreux os de mammouth. Elles ont ainsi créé le fameux cimetière, autrefois considéré comme un exemple d'accumulation naturelle de restes de proboscidiens dans le paysage périglaciaire.
L'histoire "glaciale" des mammouths de l'Arctique sibérien
Dans un communiqué, les auteurs de l'étude rappellent que les premiers ancêtres des mammouths laineux sont situés dans le Pliocène (il y a 2,58 à 5,33 millions d'années), avant que leurs populations ne se développent véritablement au Pléistocène (entre 2,58 millions d'années à environ 11 700 ans).
Seulement, en raison notamment du réchauffement global lié à la fin de la dernière glaciation, marquant le début de l'Holocène, leurs effectifs ont progressivement diminué pour donner naissance à des populations isolées dans la Sibérie moderne et l'Alaska.
Elles y ont parfois donc côtoyé les hommes avant leur extinction, estimée il y a environ 4 000 ans. De quoi donner un des exemples les plus connus du "Problème Tiffany", théorisé par l'écrivain Jo Walton, selon lequel un fait historique semble anachronique ou irréaliste pour les publics modernes : oui, alors même que les anciens égyptiens bâtissaient les pyramides, une poignée de mammouths survivait encore aux confins du cercle polaire.
En ce qui concerne la population spécifique de Berelekh, une équipe de l'Académie des sciences de Russie s'est engagée dans une réévaluation des données stratigraphiques et paléogéographiques recueillies en 2009. Elle a été complétée par de nouveaux travaux sur le terrain, sur les rives gauches de la rivière, où des ossements se sont facilement détachés de leur emplacement initial dans le sédiment et sont apparus au bord de l'eau.
À proximité, des restes de lièvres, de renards arctiques et de loups du Pléistocène ont aussi été identifiés, ainsi que des traces de foyers où des défenses de mammouth étaient travaillées ; une lance de jet inachevée y notamment été retrouvée.
Des humains au cœur de la création du "cimetière"
Premièrement, là où il était auparavant estimé que les humains étaient arrivés 50 à 80 ans après l'importante accumulation des ossements des éléphantidés, les nouvelles investigations révèlent que cela est très peu probable. Tout d'abord, leurs datations sur une large période - de 13 700 à 11 800 av. J.-C., avec des pics respectifs à 12 400, 12 200 et 11 800 av. J.-C. - sont trop étalés pour correspondre à un événement d'extinction de masse. Le débit de la rivière sibérienne, quant à lui, était autrefois bien trop faible pour avoir charrié les lourds restes des pachydermes morts à son amont.
L'étude met aussi en lumière la présence de larves de mouches dans les cavités des crânes et des os des mammouths, qui montrent que les carcasses ont été ajoutées au "cimetière" après qu'ils aient été décharnés. Les chercheurs ont en outre identifié des preuves selon lesquelles les restes ont été triés : seuls les plus précieux auraient été transportés à Berelekh depuis le lieu où l'animal a été tué, quand les parties les moins intéressantes (colonnes vertébrales, "mains" et "pieds") auraient été laissées.
Il semble donc que les humains ont bel et bien été responsables de la création du "cimetière" de mammouths, davantage exploités pour leur ivoire que pour leur viande. Trois quarts des animaux de Berelekh étaient des femelles, peut-être parce qu'elles étaient des proies plus petites. Mais aussi, car leurs défenses rectilignes étaient certainement plus appréciées que celles des mâles, courbées. Les lièvres auraient quant à eux été ciblés pour leur fourrure et la production de vêtements d'hiver.
En outre, soulignent les scientifiques, la période de 13 700 à 11 800 av. J.-C. correspond à la dite "déglaciation de Bølling-Allerød", où l'hémisphère nord s'est réchauffé. Les données issues de l'analyse des grains de pollen prélevés dans les carottes de glace, les "preuves polliniques", suggèrent que la région est alors devenue plus aride - ainsi, plus "accueillante" (ou plutôt, moins inhospitalière) pour les humains. Les nouvelles recherches dévoilent pourtant que le site n'était pas occupé de manière permanente, bien que des populations y passaient du temps de manière récurrente.
Entre pillages et découvertes sur le site de Berelekh
Aussi important que se révèle ce site, il aurait pu l'être bien davantage. Des pilleurs d'ivoire l'ont détroussé avant qu'il ne soit étudié, vendant en 1974 (et selon les estimations) pas moins de cinquante défenses. Qui sait les précieuses informations qu'elles auraient pu renfermer ? D'autant que des questions restent sans réponses : d'où provient le petit nombre d'ossements déposés sur le site avant que l'activité ne devienne plus intense ? Est-il possible que de premiers mammouths soient morts naturellement sur place, avant que les humains ne décident d'y établir leur "atelier d'ivoire" ?
Les chercheurs font toutefois remarquer que bien que Berelekh ait été initialement perçu comme unique lors de sa découverte, il peut maintenant être compris comme l'un des nombreux "cimetières" de mammouths similaires, déjà découverts à travers l'Eurasie du Nord.
Sur le site paléolithique de Yana par exemple, en Sibérie septentrionale également, des enquêtes avaient permis d'estimer que le nombre de mammouths ajoutés par les anciennes populations à "l'accumulation d'ossements" augmentait d’un à deux par an. Un chiffre qui pourrait être similaire, voire plus élevé pour Berelekh.

Московские математики Ранджит Сингх и Александр Теретенков нашли потенциальный способ увеличить количество фотонов в квантовой системе, находящихся в состоянии суперпозиции и снизить квантовый шум, повысив тем самым квантовую чувствительность.

One of the most counter-intuitive aspects of quantum physics is the idea that a quantum system, unlike a physical system governed by the everyday physics of the macroscopic universe, can exist in two states at once even if these states are contradictory.
This is called a superposition, and the states are then described as overlapping waves. The superposition is resolved by constructive or destructive interference caused when the peaks and troughs of different waves meet and amplify or cancel each other, causing a single wave to emerge.
This is perfectly exemplified by the "Schrödinger's cat" thought experiment, in which a hypothetical cat sealed from observers is both dead and alive until a measurement is made and the superposition collapses, causing a single state to resolve itself.
As wild as the concept of a superposition of contradictory states may sound, this principle and other forms of "quantum weirdness" are at the heart of a revolution in technology that includes quantum sensors, which use the fundamental properties of photons to make measurements, and quantum computers.
In quantum computers, for instance, the fundamental units of standard computers, "bits" are replaced with "quantum bits" or "qubits," which can exist in a superposition of multiple contradictory states at once, i.e., a Schrödinger cat state.
A new paper published in Physics Open by Ranjit Singh, an independent researcher based in Moscow, Russia, and Alexander E. Teretenkov from the Steklov Mathematical Institute of the Russian Academy of Sciences details how the sensitivity of quantum technology can be improved by using Schrödinger cat states that are "squeezed" to compress the amount of noise - that is, random, unpredictable, and undesirable signals - affecting measurements.
"Squeezed Schrödinger cat states can potentially be used to identify small perturbations if they are coupled to the perturbation medium. Such a precession can be more advantageous compared to Schrödinger cat states without squeezing," Singh says.
"Our theoretical research opens potential ways to increase the number of photons in the Schrödinger cat state, increase the quantum sensitivity, and preserve the interference present in the Schrödinger cat state by using optical parametric processing."
He adds that it is difficult to increase the number of photons in the Schrödinger cat state, but he and Teretenkov found the mechanism of an optical parametric process that does just this. Singh explains that the parametric process used also preserves the interference parameters and "squeezes the noise" in a quantum system. Reducing the noise while upping the number of photons increases the quantum sensitivity.
"Research on the use of squeezed Schrödinger cat states is quite interesting. It has started to develop rapidly and is promising in many aspects of modern quantum physics and quantum technologies," he adds. "Squeezed states are widely used in quantum optics, and Schrödinger cat states are now actively attracting the attention of scientists and technologists."
This research doesn't just have theoretical implications but can lead to specific applications in significant quantum technologies, in particular in quantum sensors. "Our research is at the intersection of important trends in modern quantum physics," Singh concludes.

Сотрудники Института археологии РАН обнаружили на раскопках в Суздале резную костяную пластинку с детально проработанным изображением вооруженного человека. Пластинка относится к 12-13 вв. и представляет собой декоративную накладку на шкатулку - такие изготавливались в то время в Византии и пользовались большой популярностью. Это первая подобная находка на территории Суздаля.

Archaeologists in western Russia have discovered a bone carving depicting a medieval warrior. Dating to the 12th or 13th century, it is exceptionally detailed, with one being able to see the folds of the cloak, the warrior’s muscles, and flowing hair.
The discovery was made in fortifications just outside of Suzdal, one of Russia’s oldest towns. The Institute of Archeology from the Russia Academy of Sciences announced the find, which is a bone plate with a relief carving. The square plate, measuring 45 x 46 mm and about 4 mm thick, features a smooth frame surrounding a central image of a warrior in a cloak, depicted in mid-attack. The warrior holds a shield in his left hand and a sword in his raised right hand. The plate has six asymmetrically placed mounting holes, each just over 3 mm in diameter.
The plate is believed to be a decorative element from a casket made in Byzantium during the Middle Ages. These wooden boxes were adorned with carved bone plates depicting various scenes. The plates were attached to the wooden base with bone nails or pins and were typically placed on the side panels or lid. Such items were widespread from the 10th to the 12th centuries.
These highly artistic caskets were likely produced in workshops in Constantinople. Initially made from ivory, by the 12th century, simpler bone from domestic or wild animals became more common. This shift reflected a broader audience for these products or the rise of provincial bone-carving workshops. Chersonesus is considered a center for casket production, with Constantinople’s artistic bone-carving craft serving as a model for imitation in peripheral workshops.
Direct analogies to the Suzdal plate are found in Byzantine art, such as the side plates of boxes from the State Hermitage and the Novgorod Museum of the Reserve. However, unlike the Suzdal find, these are made of ivory.
Bone plates with artistic relief carvings are extremely rare and valuable in medieval Rus’. Individual ornamented plates and fragments have been excavated in Gnezdovo, Smolensk, and Novogrudok. This discovery is the first of its kind in Suzdal. The plate was found in a small excavation area of just over 70 square meters, where two estates from the 12th to 14th centuries were partially explored. Other notable finds at the site include stone crosses, an encolpion, a glass vessel with enamel painting, and seals. The plate came from a pit filled between the mid-12th to early 13th centuries.
While the exact place of manufacture - whether in Constantinople or another Byzantine workshop - is yet to be determined, the discovery highlights the estate’s extraordinary nature and the wealth of its inhabitants. The casket, adorned with bone overlays and intricate relief images, reflects the artistic applied art of the time. This find also underscores the cultural and material connections between medieval Suzdal and the Byzantine world, as the naked warrior in a cloak echoes ancient scenes, indicating familiarity with ancient images and mythology alongside traditional Christian elements.

Специалисты Высокотехнологического научно-исследовательского института неорганических материалов им. А.А.Бочвара разрабатывают с помощью цифровых моделей композитные оболочки для твэлов на основе карбида кремния. Такие оболочки позволят полностью исключить риск пароциркониевой реакции, ставшей причиной аварий на АЭС в Чернобыле и Фукусиме.

Specialists at Russia’s A.A. Bochvar Research Institute of Inorganic Materials (VNIINM, part of Rosatom’s TVEL fuel company) have developed composite fuel shells based on silicon carbide. The use of digital twin technology saved time and money on the experiments.
Tolerant fuel with silicon carbide shells will not only minimise, but completely eliminate the risk of a steam-zirconium reaction - the main cause of almost all past accidents at NPPs. But this material is unpredictable and fragile, and it is impossible to make fuel tubes from it using technology developed for metals. VNIINM proposed another method - a frame woven from silicon carbide fibre and impregnated with a matrix material based on the same silicon carbide.
The basic technology was understood, but developers still had many questions. At what angle should the fibres be wound when weaving? What is the optimal thickness of a monolithic silicon carbide part? How to achieve a sealed shell? VNIINM engineer Alexey Sorokin used a digital twin to help to find the answers.
Sorokin is a programmer and physicist who studied at the Moscow Energy Institute’s Department of Engineering Thermophysics. In the third year, he joined the modelling group and began to develop calculation codes for thermal and thermophysics. At VNIINM, he was given a specific task - numerical modelling of the behaviour of a fuel rod with a composite cladding.
"The double is a set of digital calculation models," he explained. "A library of material properties has been collected for it - the shell, the end element of the fuel rod and their solder joint. Numerical models of mechanical tests and main components of fuel rods are ready. As data is received, the digital twin will be updated with models."
The twin is already helping to reduce the number of experiments.: "There is no need to make 20 expensive samples with different fibre winding angles and study the mechanical characteristics of each," said Sorokin. "They can be simulated by calculation and the optimal winding angle can be determined."
Researchers examine the sample and describe the initial geometry, the loading process, and the strength of the sample’s resistance to the applied load. Sorokin recreates a numerical model of mechanical testing in the calculation code, verifies it - and it is possible to conduct a numerical study and select optimal parameters. "For example, a tensile experiment on a tubular sample. I made a model and looked at the experimental data. Then I conducted research and found out in which weaving configuration the strength characteristics would be better, and gave feedback to the technologists."
Developers of silicon carbide claddings are thinking about how to achieve gas-tightness of fuel rods during operation. There is an idea to add an intermediate layer of metal liner from the standard E110 alloy. A digital twin will help to calculate its thickness.
Sorokin carries out calculations using the foreign code Abaqus, based on the finite element method (FEM). In parallel with other computer modelling specialists, he is developng import-substituting codes "Startup" and PK3D.
The digital twin of silicon carbide-based fuel cladding manufacturing technology will be developed along with research and development work on the project as a whole. "Any new information, any new test should complement the twin, expand the digital model of the object," Sorokin noted. "The twin will be completely ready when we introduce the technology into production. It will, of course, be improved all the time: the industry is constantly fighting to improve the energy efficiency of nuclear fuel."
The development of composite fuel claddings at VNIINM began in 2014. By the end of 2023, 55 samples had been manufactured of 11 types of gas-tight shell pipes up to 500 mm long with different weaving architectures, frame compaction methods, and deposition modes of the silicon carbide matrix and interphase layer.
The first reactor tests of silicon carbide shells in Russia were a milestone. Last summer, the Research Institute of Atomic Reactors (NIIAR) completed the first irradiation cycle in the BOR-60 research reactor. Tests took place at temperatures up to 360 °C. By 2030, VNIINM specialists have to make optimised sealed gas-tight claddings of fuel rods up to 1 metre long and conduct a set of pre-reactor tests to check compatibility with the nuclear fuel.

Якутские ученые провели исследование останков древнего волка возрастом около 44 тысяч лет, найденного в вечной мерзлоте в 2021 г. У животного отлично сохранились не только кости, зубы и шерсть, но и мягкие ткани и внутренние органы, например, желудок со всем содержимым, что позволит получить информацию о волчьем рационе. Исследователи также намерены сравнить ДНК животного с геномом современных волков.

A ferocious-looking ancient wolf with its fearsome teeth intact has been uncovered from Siberian permafrost after 44,000 years. Experts say the adult male wolf found in Yakutia, eastern Russia, has amazingly-preserved fur, bone and even organs, as well as teeth and bone. It's been transferred to the Mammoth Museum Laboratory of the Northeast Federal University in Yakutsk, where it's been undergoing an autopsy.
Permafrost is ground that remains permanently frozen even during summer months - and can stay frozen for thousands of years. Ancient remains found in permafrost are among the most complete ever found because the ice stops organic matter from decomposing.
The wolf was discovered by locals in 2021 in the permafrost at a depth of about 130 ft by the Tirekhtyakh River in the Abyi district of Yakutia, Russia’s coldest region. Experts say it is the oldest known wolf to undergo such an autopsy - and even its stomach has survived.
"Its stomach has remained isolated, without contamination", said Dr Albert Protopopov, head of the Mammoth Fauna Study Department of the Yakutia Academy of Sciences. "As a result of the dissection, we hope to get an instantaneous cross-section of the biota of the ancient Pleistocene period. It was an active and large predator, and we have the opportunity to find out what it ate. Additionally, its stomach contains the remains of what its prey consumed."
Dr Maxim Cheprasov, head of the Mammoth Museum Laboratory, said: "We extracted a premolar - a tooth - to determine the biological age of the find. However, based on the wear of the teeth and the development of the sagittal crest, we can already say that this is an adult male".
Professor Artemy Goncharov, head of the Functional Genomics and Proteomics Laboratory at the Institute of Experimental Medicine, said such investigations could lead to modern-day benefits.
"We see that live bacteria can survive in the finds of fossil animals for millennia, serving as witnesses to those ancient times," he said. "We hope for good results that will allow us to further understand what ancient microbial communities were like, what function they performed, and how dangerous pathogenic bacteria were represented in their structure. It is possible that microorganisms will be found that can be applied in medicine and biotechnology as promising producers of biologically active substances. Therefore, this research has a special influence on the future".

10 тысяч лет назад из-за подъема уровня моря стадо мамонтов оказалось изолировано на острове Врангеля у побережья Чукотки. Их потомки прожили на острове 6 тысяч лет, став последними представителями своего вида на Земле. По одной из наиболее распространенных версий, причиной их вымирания стал инбридинг - близкородственное скрещивание, приведшее к накоплению мутаций. Однако международный коллектив палеогенетиков, в том числе российских, изучив геномы 14 врангелевских мамонтов и 7 материковых, пришел к выводу, что, несмотря на явные признаки инбридинга и низкое генетическое разнообразие, обитатели острова были вполне жизнеспособны, а серьезных мутаций имели даже меньше, чем материковые собратья. Оказавшись на острове, популяция сначала сократилась всего до 8 особей, но за 20 поколений снова увеличилась до 300 особей и стабильно просуществовала несколько тысячелетий. Что бы ни стало причиной вымирания, случилось это, по мнению ученых, неожиданно и быстро.

In science, we usually share our successes and ignore the less glamorous mishaps. We decided to follow a different approach. This is the story of how multiple generations of scientists collaborated to decipher the genome of the mammoth formerly known as Lonely Boy, often referred to as the last mammoth on the Earth.
The woolly mammoth was one of the most charismatic species of the last Ice Age, between roughly 120,000 to 12,000 years ago. Yet, the cause of its extinction remains a mystery. Mammoths roamed large parts of the northern hemisphere during their heyday, but by the end of the Ice Age, they had disappeared from most of their former range. The last mammoth population lived on Wrangel Island, a small island off the Siberian coast, until its final demise about 4,000 years ago.
In our new study, published in Cell, we investigated whether the Wrangel Island mammoth population was genetically destined for extinction. And despite many mistakes along the way, we ultimately discovered it wasn’t.
Mammoths became isolated on Wrangel Island around 10,000 years ago due to rising sea levels and survived as a small population for thousands of years. Inbreeding is a common problem in small populations and its negative effects could accumulate over time, eventually leading to an unviable population and extinction.
Inbreeding can cause lots of issues. Portraits of Charles II of Spain, last monarch of the Habsburg house, show his deformed chin due to generations of inbreeding. Scientists have long wondered whether genomic processes led to the extinction of the mammoths on Wrangel Island.
To address this, we generated a dataset of 21 mammoth genomes spanning the last 50,000 years of the species’ existence. This dataset allowed us to travel back in time and study the genetic effects of their isolation over time.
Lonely Boy was the most precious individual in our dataset, the sample key to understanding why mammoths went extinct. Sequencing Lonely Boy’s DNA, however, proved to be challenging.
The adventures of Lonely Boy
Generating a genome for Lonely Boy took multiple attempts over a time span of almost ten years. In our first attempt to extract DNA, our sample turned out to be plagued with human contamination. In our second attempt, we used bleach to remove as much contamination as possible.
Although this is common practice in the field of ancient DNA, it also comes with the trade-off that some of the mammoth DNA will also inadvertently be destroyed. In our case, it meant that not enough mammoth material was left in the sample to generate a high-quality genome.
In a final attempt, we merged the data from the different DNA extracts from Lonely Boy. However, the DNA from our different extracts, while similar, looked like it belonged to different individuals. We came up with the wildest theories as to explain these new results.
One of our leading theories at the time was that Lonely Boy had a condition called the "vanishing twin syndrome". Apparently, in some rare cases, a mammal foetus can absorb the genetic material of a diseased twin during gestation. This would explain why the DNA extracts looked similar, yet not entirely identical.
In the end, the explanation was not nearly as exciting and could all be tracked back to the egregious amount of effort we had put into this sample. This resulted in strange lab artefacts (which is anything causing difficulty in interpreting a specimen) - normally not even noticeable - that introduced a false genetic variation in the sample. We therefore created a simple filter to remove these artefacts.
But even after all these steps, Lonely Boy still looked like an outlier. At this point, we decided to re-date the sample. Lonely Boy had been dated a long time ago and methods have considerably improved since then.
The result came as a big surprise. Lonely Boy was not 4,000 years old as initially thought, but closer to 5,500 years - making him a completely average mammoth in our dataset, rather than the last such individual on Earth.
Causes of extinction
To answer the original question of this project, no, the Wrangel Island population did likely not go extinct due to inbreeding. By comparing our genomic data with results from computer simulations, we now know that the population decline of the mammoths after isolation on Wrangel Island some 10,000 years ago must have been huge, with only eight breeding individuals remaining.
Nevertheless, our results show that the population recovered quickly to a population size of 300 within 20 generations and remained stable until the mammoth’s final demise. We can see it remained stable since there is virtually no change in inbreeding levels through this period.
However, our results on harmful mutations tell a different story. While the most harmful mutations were gradually purged from the population through natural selection, mildly harmful mutations accumulated over time. This indicates that the initial population decline - despite fast recovery - had long-lasting genetic effects.
Predicting the exact effect of harmful mutations is challenging, especially in an extinct species. Comparison with known human diseases suggests that some of the most harmful purged mutations likely disrupted genes that may have been important for the development of different senses, like hearing and sight.
Yet it seems unlikely that this caused the mammoth’s final demise. Based on our results, the extinction must have happened rapidly. Humans did not co-exist with mammoths on the island, but a sudden event, such as a disease outbreak or a weather event, could have caused the population’s sudden extinction.
As with most things in science, more research will hopefully provide new insights. Potentially even with a new Lonely Boy or Girl.
Although we eventually managed to analyse the inbreeding of mammoths, it was a long journey with many detours. Yet, as a lab group we learned a lot from this project. We came up with a new bioinformatic method to deal with human contamination and discovered a new type of lab artefact. This new information may well be crucial to pinpoint the exact reasons why the woolly mammoth became extinct.

В какой момент человеческой истории одежда помимо чисто утилитарной функции приобрела функцию социальную, став инструментом обозначения групповой принадлежности, статуса в обществе и способом самовыражения?
Ученые из Австралии, Франции, Китая и России (Институт геологии и минералогии имени В.С.Соболева СО РАН) связывают этот переход с изобретением сначала костяных шильев, а потом игл с ушком, самые ранние из которых появились примерно 40 000 лет назад в Сибири. Иглы позволяли создавать одежду более сложного покроя, а также украшать ее.

From stone tools that prepared animal skins for humans to use as thermal insulation, to the advent of bone awls and eyed needles to create fitted and adorned garments, why did we start to dress to express ourselves and to impress others?
Clothing is understood as a significant component in shaping what makes us human. The emergence of clothing enabled our ancestors to inhabit more corners of the world, access different resources and environments, and connect with a broader community. Today, clothing is associated with identity and status. Yet archaeological evidence indicates that apart from thermal reasons, clothing was not intrinsic for society or cultures to function.
A team of researchers led by Dr Ian Gilligan, Honorary Associate in the discipline of Archaeology at the University of Sydney, are the first to suggest that eyed needles were a new technological innovation used to adorn clothing for social and cultural purposes, marking the major shift from clothes as protection to clothes as an expression of identity.
"Eyed needle tools are an important development in prehistory because they document a transition in the function of clothing from utilitarian to social purposes," says Dr Ian Gilligan.
Dr Gilligan and his co-authors reinterpret the evidence of recent discoveries in the development of clothing in their paper, Paleolithic eyed needles and the evolution of dress.
"Why do we wear clothes? We assume that it’s part of being human, but once you look at different cultures, you realise that people existed and functioned perfectly adequately in society without clothes," Dr Gilligan says. "What intrigues me is the transition of clothing from being a physical necessity in certain environments, to a social necessity in all environments."
The earliest known eyed needles appeared approximately 40,000 years ago in Siberia. One of the most iconic of Paleolithic artefacts from the Stone Age, eyed needles are more difficult to make when compared to bone awls, which sufficed for creating fitted clothing. Bone awls are tools made of animal bones that are sharpened to a point. Eyed needles are modified bone awls, with a perforated hole (eye) to facilitate the sewing of sinew or thread.
As evidence suggests bone awls were already being used to create tailored clothes, the innovation of eyed needles may reflect the production of more complex, layered clothing, as well as the adornment of clothes by attaching beads and other small decorative items onto garments.
"We know that clothing up until the last glacial cycle was only used on an ad hoc basis. The classic tools that we associate with that are hide scrapers or stone scrapers, and we find them appearing and going away during the different phases of the last ice ages," Dr Gilligan explains
Dr Gilligan and his co-authors argue that clothing became an item of decoration because traditional body decoration methods, like body painting with ochre or deliberate scarification, weren’t possible during the latter part of the last ice age in colder parts of Eurasia, as people were needing to wear clothes all the time to survive.
"That’s why the appearance of eyed needles is particularly important because it signals the use of clothing as decoration," Dr Gilligan says. "Eyed needles would have been especially useful for the very fine sewing that was required to decorate clothing."
Clothing therefore evolved to serve not only a practical necessity for protection and comfort against external elements, but also a social, aesthetic function for individual and cultural identity.
The regular wearing of clothing allowed larger and more complex societies to form, as people could relocate to colder climates while also cooperating with their tribe or community based on shared clothing styles and symbols. The skills associated with the production of clothing contributed to a more sustainable lifestyle and enhanced the long-term survival and prosperity of human communities.
Covering the human body regardless of climate is a social practice that has endured. Dr Gilligan’s future work moves beyond the advent of clothing as dress and looks at the psychological functions and effects of wearing clothes.
"We take it for granted we feel comfortable wearing clothes and uncomfortable if we’re not wearing clothes in public. But how does wearing clothes impact the way we look at ourselves, the way we see ourselves as humans, and perhaps how we look at the environment around us?"

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