Российская наука и мир (дайджест) - Август 2019 г.
Навигация
Дайджест за другие годы
Август
2019 г.
Российская наука и мир
(по материалам зарубежной электронной прессы)

январь февраль март апрель май июнь июль август сентябрь октябрь ноябрь декабрь
    Livescience / August 05, 2019
    13th-Century Death Pit Reveals Murdered Family in the "City Drowned in Blood "
    The group was found among hundreds of bodies consigned to mass graves.
    • By Mindy Weisberger
    Генетические исследования останков из массовых захоронений людей, погибших при захвате Ярославля Батыем в 1238 году, подтвердили случаи семейных связей, предположенных археологами и антропологами.

When Mongol soldiers swept through the Russian town of Yaroslavl in 1238, a bloodbath followed. Hundreds of people died horrific and violent deaths during the city's capture, and DNA evidence has now revealed a tragic glimpse of a family of victims spanning three generations.
Following the massacre, bodies were dumped in mass graves by the dozens. No markers identified individuals, but scientists used genetic analysis of corpses in one grave to discover that three of the dead - two women and a young man - were close relatives: a mother, her daughter and her grandson.
The matriarch of the trio was at least 55 years old, her daughter was around 30 to 40 years old and the grandson was no more than 20. The grave that held the family's bodies was one of nine death pits at Yaroslavl. Together, the pits held more than 300 corpses, the researchers reported recently at the Alekseyev Readings conference, held Aug. 26 to 28 at the Anuchin Research Institute and Museum of Anthropology in Moscow.
Prior examination of the bones by anthropologists suggested that the trio might be related; they shared certain skull features, and all of their skeletons showed signs of spina bifida, a hereditary birth defect that produces an underdeveloped spinal cord.
The three family members were discovered in a burial pit holding 15 bodies, at a homestead inside a citadel in Yaroslavl's inner city. Though much of the site was burned during the city's capture, surviving buildings and artifacts hinted that it was once a wealthy estate, the researchers said in the presentation.
Further evidence of the murdered family's wealth was detected in their teeth. Their remains showed more advanced tooth decay than in the other townsfolk, hinting that the family's diet included regular helpings of honey and sugar - a sign of elevated status, according to the presentation.
Genetic analysis also pinpointed a possible fourth family member, a maternal relative, buried nearby, the scientists said.
"Drowned in blood"
Excavation work at Yaroslavl from 2005 to 2006 determined that the massacre took place in February in 1238. But the species and life stages of preserved maggots (blowfly larvae) in the remains indicated that the flies laid their eggs on the corpses in warm weather. That finding suggested that the bodies were likely decomposing in the open for months before being buried.
"These people were killed, and their bodies remained lying in the snow for a fairly long time," said Asya Engovatova, head of excavations at the Yaroslavl site and deputy director of the Institute of Archaeology at the Russian Academy of Sciences.
"In April or May, flies started to multiply on the remains, and in late May or early June, they were buried in a pit on the homestead, which is where they probably had lived," Engovatova said in a statement.
The Mongol army that invaded Russia and decimated Yaroslavl in the early 13th century was led by Batu Khan, grandson of Genghis Khan and founder of the kingdom known as the "Golden Horde." Though scholars have argued that Khan's Golden Horde peacefully acquired territory in Russia, the gruesome evidence at Yaroslavl proves otherwise, the scientists said.
Signs of brutality at Yaroslavl were seen in the hundreds of hastily buried bodies, their bones punctured, broken and burned. By the time the Mongol invaders were done with Yaroslavl and the Russian town had fallen, it was truly a "city drowned in blood," the horrific fate of its residents later woven into legend, Engovatova said in the statement.
"Batu Khan's conquest was the greatest national tragedy, surpassing any other event in cruelty and destruction," Engovatova said. "It is not by chance that it is among the few such events that made its way into the Russian folklore."

© Future US, Inc.
* * *
    CNN / August 6, 2019
    Fires, floods (and even bugs) are challenging Russia's stance on the climate crisis
    • By Mary Ilyushina and Frederik Pleitgen
    Лесные пожары, наводнения, таяние вечной мерзлоты, карстовые воронки - экологи предупреждают, что на фоне глобального и регионального изменения климата количество экстремальных природных явлений в Сибири будет расти.

Landing in Yakutsk, six time zones east of Moscow, the first thing you see and smell is thick, acrid smoke.
This is one of the coldest inhabited places on Earth, and just one of the dozens of Russian cities choked by the wildfires that have been ravaging the Arctic this season at unprecedented levels.
"These past weeks it's been impossible to breathe, the smoke is coming from the woods all around us, so we were all warned to stay inside," said Murtaz, a local taxi driver who declined to give his second name, as he drove past a lookout point of the smog-filled city. "But the bugs are the worst - literally hundreds of them are fleeing the fire and swarming all over you."
Alaska and Canada have also been affected by wildfires. But in Russia the smoke from thousands of kilometers of burning forest has spread over almost half of the country and even reached the west coast of the United States.
Fires in Siberian taiga forests happen annually, but they now have global implications. In the last three years alone, the area affected by forest fires has tripled, spewing megatons of greenhouse emissions into the atmosphere, according to official Russian estimates.
So as Siberia heats up, it has potential to accelerate global warming. But the Russian response has been slow. Authorities here at first decided not to put the fires out unless they pose a direct threat to settlements as it would be "economically unsound." In other words, local budgets were too constrained.
Complicating matters is the extraordinary logistical burden of working in the vast, undeveloped expanses of eastern Russia. Getting to hard-to-reach forest fires requires a lot of people, aircraft and fuel. But forest fires are only one part of the cascading effects of climate change. Rising global temperatures, scientists say, are tied to deforestation. Timber is a major Russian export, particularly to resource-hungry China. But as loggers move in, environmental activists say their clearcutting allows vital topsoil to wash away, weakening the ability of the earth to hold extra moisture - and making the region vulnerable to flooding.
Northern parts of the Irkutsk region were hit by wildfires before its southern areas could recover from deadly floods which took 25 lives and displaced over 30,000 people this June. The area hasn't experienced floods this strong in years, and is not used to having them this time of the year either. Researchers at Irkutsk State University said the flooding was caused by "anomalous atmospheric processes taking place amid global and regional climate change," warning that Siberia is bound to experience even more weather extremes in the future.
Climate change at the "Gateway to Hell"
While the surface of eastern Russia is on fire and flooding, its foundation is literally melting away. Two thirds of the country sit on permafrost, which is degrading rapidly, puncturing places like the Yakutia region with giant sinkholes.
The biggest known one is the Batagai crater, another thousand kilometers north of Yakutsk. Locals dubbed the gaping hole in the permafrost the "Gateway to Hell." Global climate change is often imperceptible. But at the Batagai sinkhole, you can witness the effects in near-real time. What sounds like heavy rain from afar is in fact water streaming down the walls of a giant black glacier. This is the sound of melting permafrost. Cracking is audible as ice and frozen earth break loose and falling hundreds of meters from the edges of the crater.
"At first we thought that some meteorite fell here but turns out it was all human factor," says local resident Erel Struchkov. "It used to be a logging area, then people made a little pathway, which turned into a little creek and then, bit by bit, it grew into this massive thing." And it keeps growing - about 10-15 meters sink each year. The locals are worried it might envelop their village, and that other holes could endanger more populated areas, where much of the infrastructure sits precariously on permafrost.
"This is massive social issue," said Alexander Fedorov, the lead scientist at Yakutsk Permafrost Institute. "The infrastructure - buildings, gas lines, water pipes, railroads, roads - is decaying which comes at a big cost."
And that's where the forest fires are also raising alarms. According to Fedorov, areas where the permafrost sits under trees - both untouched - are much less prone to degradation.
Dependence on fossil fuels
Russian President Vladimir Putin has already ordered the military to send planes and helicopters to help fight the inferno. The fires even took on a geopolitical dimension last week, after US President Donald Trump also offered to send help.
For now, the Russian government is tentatively acknowledging the effects of climate change. Putin paid a visit to Irkutsk flood victims on his way to the G20 summit in Osaka in June, where he delivered a message about climate change.
"I want to remind you that in Russia we are warming 2.5 times faster than the rest of the planet. This is a serious challenge to us. We must understand this," Putin said. "Hence the floods and the melting of permafrost in areas where we have big settlements. We need to understand how to respond to the climate change happening there."
Standing up to this challenge would require an environmental policy to cut dependence on fossil fuels - a cornerstone of the Russian economy. But a summer of wildfires and flooding may be changing the way Russians feel about action on climate change.
"We need to lessen the human impact. When climate change meets human factor, the effect is colossal," Fedorov said. "If we don't cut down the forests, if we don't cause fires the permafrost can be more stable... The point of no return is almost here, we are at a critical point already when it comes to permafrost."

© 2019 Cable News Network. Turner Broadcasting System, Inc. All Rights Reserved.

* * *

    Reuters / August 14, 2019
    Kremlin warns of foreign espionage as scientists chafe under new restrictions
    • Tom Balmforth
    Приказ Минобрнауки о новых правилах взаимодействия российских учёных с иностранными коллегами, разосланный по организациям в июле, вызвал резко негативную реакцию, после чего министерство заявило, что документ носит «рекомендательный характер».

The Kremlin said on Wednesday Russia must be vigilant in protecting its industrial secrets against foreign intelligence services after scientists criticized new restrictions on them meeting foreigners.
Under an order issued by the education ministry in February but which has only now come to light, government-affiliated scientists are advised to meet their foreign colleagues only if they are accompanied and have been formally authorized to do so.
The order urges scientists to inform their superiors five days in advance of any plans to meet foreign scientists and also to report back on what was discussed. In an open letter on Wednesday, scientist Alexander Fradkov criticized the guidelines, which he outlined in detail, and called on the ministry to revise or abandon them.
"Such ridiculous and impossible orders will not improve the security of our country, but will only lead to an increase in its isolation from developed countries and discredit the government...," he wrote.
Asked about the directive, Kremlin spokesman Dmitry Peskov said he had not seen it but that, though it sounded excessive, it was nonetheless important for Russia to be wary of foreign espionage.
"Of course, we need to adopt a certain vigilance because foreign intelligence services are not dozing and, let’s put it like this, nobody has canceled industrial espionage," he said.
"It happens 24 hours a day, seven days a week, and is directed against our scientists, particular young scientists," he told reporters on a conference call.
He promised, however, to look into the ministry order and said it was important not to get carried away with stringent rules.
A number of Russian scientists have been arrested and charged with treason for handing over sensitive material to foreigners in recent years, in cases that Kremlin critics have said are the result of groundless paranoia.
Later on Wednesday, the education and science ministry said the measures should be seen as recommendations mainly aimed at keeping tabs on the "rise in international ties", the TASS news agency reported.

© 2019 Reuters. All Rights Reserved.

* * *

    Quanta Magazine / August 19, 2019
    Can New Species Evolve From Cancers? Maybe. Here’s How
    Researchers agree it’s a long shot, but transmissible cancers could theoretically evolve into independent species. Certain weird parasites might be living proof.
    • Christie Wilcox
    Российский биолог Александр Панчин (Институт проблем передачи информации РАН) с коллегами выдвинул гипотезу о том, что трансмиссивные формы рака могут трансформироваться в самостоятельные виды, эволюционируя до уровня многоклеточности. Научное сообщество сочло предположение очень смелым, но не лишенным оснований и заслуживающим дальнейшего изучения.

Agressive cancers can spread so fiercely that they seem less like tissues gone wrong and more like invasive parasites looking to consume and then break free of their host. If a wild theory recently floated in Biology Direct is correct, something like that might indeed happen on rare occasions: Cancers that learn how to roam between hosts may gradually evolve into their own multicellular species. Researchers are now scrutinizing a peculiar group of marine parasites called myxosporeans to see whether they might be the first known example.
Even among microscopic parasites, myxosporeans are enigmatic. They were first discovered nearly two centuries ago, and more than 2,000 species are recognized today. Their complex life cycles make study particularly difficult: It wasn’t until the 1980s that scientists realized the ones found in fish were the same species as those found in worms, and not completely different classes of parasite. And while most parasites are content merely to snuggle into their animal host’s tissues, myxosporeans often take up residence inside a host’s own cells.
Until fairly recently, myxosporeans were considered to be protists, offshoots of the eukaryotic line that are neither plants, animals nor fungi. In 1995, however, Mark Siddall, then at the Virginia Institute of Marine Science, and his colleagues argued that myxosporeans are weird members of the cnidarians, the group that includes jellyfish and corals. Since then, genetic studies have bolstered that position.
But their location on the tree of life doesn’t explain how myxosporeans ended up with such strange traits. Myxosporeans boast some of the smallest known animal genomes. The genome of Kudoa iwatai, for example, is estimated to be a mere 22.5 megabases, considerably smaller than that of any other cnidarian genome. It’s less than one-twentieth the size of the genome of Polypodium hydriforme, a closely related cnidarian parasite.
Moreover, their genomes have not just been catastrophically reduced. They specifically lack certain genes thought to be essential for multicellular life. It’s not clear how or why a complex multicellular creature discarded these seemingly necessary genes along with huge chunks of its DNA.
Yet Alexander Panchin, a senior researcher at the Russian Academy of Sciences, and his colleagues have an intriguing if controversial hypothesis to explain it. Early this year, they proposed that myxosporeans initially branched off from their cnidarian kin not as independent animals but as tumors.
Evolutionary Scandals
Panchin knows the idea of cancer-derived animals sounds far-fetched - so much so that, in the paper, he and his co-authors refer to them as Scandals (an acronym for "speciated by cancer development animals").
At first, Scandals were just a thought experiment. While Panchin was writing about transmissible cancers, he heard his colleagues express surprise at the genes for complex tissues that were turning up in certain unusual but simple parasitic animals. Further conversations led to what Panchin calls the "fantastic" idea that such simple parasites could have cancerous origins. "So we took all the data and we proposed this hypothesis," he said.
According to Panchin’s three-step scenario, a Scandal would start off as a cancer, but not just any cancer. It would have to be transmissible, so that it wouldn’t die when its host did. Then the cancer would have to spread to other species, and then independently evolve multicellularity. Those steps might seem to present insurmountable barriers, and yet there’s reason to believe each one could have happened.
The first step, the emergence of the transmissible cancer, is the most straightforward because we know it happens, although it is rare. Devil facial tumor disease (DFTD) has become notorious as a transmissible cancer devastating Tasmanian devils, who transmit it to one another in their bites. More common but perhaps less famous is canine transmissible venereal tumor (CTVT), a sexually transmitted disease among dogs that, according to a recent analysis by Elizabeth Murchison of the University of Cambridge and her colleagues, has been evolving as a transmissible cancer for as long as 8,500 years. (In a 2014 report, Murchison and her co-authors described CTVT as perhaps "the oldest and most widely disseminated cancer in the natural world.")
Transmissible cancers are not confined to mammals; they have also been found in mollusks. There’s no reason to think it would be impossible for transmissible tumors to arise in a cnidarian too. Cnidarians certainly aren’t immune to cancers in general. If myxosporeans are Scandals, they most likely began as tumors of other cnidarian parasites - such as their Polypodium cousins, for instance.
Although the spread of a cancer to other species might seem unlikely, "it’s not unheard of," said Athena Aktipis, an assistant professor at Arizona State University. Aktipis, who specializes in the evolution of cancer, points to cases such as that of a man with HIV who was discovered to be infected with tumor cells from a tapeworm. Such worm cancers have turned up repeatedly among people with compromised immune systems, and the known cases likely represent only the small minority of occurrences in which the source of a strange growth was tracked down. If this kind of species hopping happens right before our eyes, "maybe we should also consider the possibility that things that were cancer or cancerlike sometimes, in the right conditions, could become parasites on other species," she said.
"I think that the field has been way too cautious about talking about when cancer becomes its own species, or its own kind of organism," Aktipis said. In her view, researchers have seen too many examples of transmissible tumors like CTVT and DFTD. "It’s a parasite. It’s a parasitic organism."
Perhaps the least likely step in the Scandal hypothesis is the one where the cancerous parasite evolves from a unicellular existence to a multicellular one with distinct hosts and stages. Myxosporeans are simple animals but truly multicellular - so if they arose from a transmissible tumor, that tumor would have had to evolve distinct cell types.
Multicellularity is thought to have evolved at least 25 times in eukaryotes, the domain of life that includes complex single-celled creatures as well as plants, animals and fungi. In animals, though, it’s believed to have arisen just once at the very base of our lineage. Some multicellular branches of the eukaryotes have reverted to unicellularity, but no animals have been known to do so (unless, like some scientists, you consider cancer itself to be a kind of reversion). As yet, there don’t seem to be lineages of any kind in which multicellularity was gained, lost and then gained again, in keeping with the Scandal hypothesis. "We understand that this is a very improbable scenario," Panchin said.
But that doesn’t mean it couldn’t have happened. "I think it’s certainly possible that clusters of cancer cells that are transmissible could evolve to have something like a life cycle," Aktipis said. "There’s nothing special about the evolutionary process that says you can only evolve a life cycle if you are a branch of the evolutionary tree that didn’t derive from [a part of] another organism."
Following the Evidence
In the hope of finding more substantive evidence for the Scandal theory, Panchin and his team compared the genomes of a variety of simple species (most of them parasitic) with those of five myxosporeans, three single-celled creatures and 29 other animals. They looked for hints of a cancerous past by checking for the absence of genes that are often lost when cells turn malignant. These include genes involved in apoptosis, the regulated self-sacrifice that purges abnormal cells from the body. Any organism evolving from a transmissible tumor would presumably lack such genes.
Although the scientists had expected other parasites to be the most likely Scandal candidates, only the myxosporeans had lost key tumor-suppressing genes. So they drilled deeper and found that the myxosporeans have lost so many genes related to apoptosis that they probably can’t trigger that death pathway at all. That deficiency stood out: "Even if you look at very simplified parasites which are animals, we don’t see this degree of lack of cancer-related genes," Panchin said.
Aktipis thinks that Panchin and his co-authors have presented some intriguing reasons why "we should at least consider the possibility that some of the parasitic organisms that we see today might have evolved from transmissible cancers." But it’s not case closed, she said. "This paper is a beginning for this work, not a decisive proof of it by any means."
Juliana Naldoni, a parasitologist and myxosporean specialist with the Federal University of São Paulo, isn’t convinced that myxosporeans are Scandals at all. "They are actually much more complex than initially thought and evolve quite intricate [and specific] mechanisms of interaction with their hosts," she said. Some species also have complex features, such as cells organized into structures resembling muscles for movement, for example. She just doesn’t find it plausible that such complexity arose from a cancer.
Adrian Baez-Ortega, a doctoral student and bioinformatician with Murchison’s Transmissible Cancer Group at the University of Cambridge, agrees with Naldoni. "It is a thought-provoking paper, if not a very convincing one," he wrote in an email to Quanta. He isn’t terribly impressed by the loss of apoptosis genes, for example. "In the context of such a dramatic genome reduction, the claim that the lack of genes specifically related to apoptosis points to a cancerous origin seems rather cherry-picked," he explained.
But mostly he’s skeptical that a transmissible cancer could last long enough to evolve multicellularity. Cancer cells have incredibly unstable genomes. Although this allows them to mutate rapidly and elude their host’s defenses, Baez-Ortega pointed out that on an evolutionary timescale, "this is a very detrimental strategy. As time goes on, a good portion of a cancer’s genome becomes nonfunctional or abnormal, and this might impede not just survival, but also the development of sophisticated traits like multicellularity." The way he sees it, "even if a transmissible cancer could have survived for millions of years, it would be much more likely to remain a unicellular parasite."
That said, he thinks the Scandal hypothesis is worth further investigation. "There is almost nothing evolution cannot do," he said. Rather than focusing on specific missing genes, he would like researchers to scan candidate species for the diverse genomic changes that occur in cancers, from point mutations to large-scale chromosome rearrangements. "If a cancer were to become a long-lived species, all these modifications would be preserved in its genome," he said.
Even Panchin and his colleagues aren’t going all-in on the hypothesis that myxosporeans are Scandals. "I think that’s fair to say it’s probably not true," he said. It’s just that, with the work they’ve done so far, they can’t rule it out. "We’ve been trying to refute it with the means that we have."
He added, "We are going to try to falsify the hypothesis through looking at the Malacosporea genome." Malacosporeans are cnidarian parasites and the closest known relatives of myxosporeans, but they are so much more complex that they are clearly not cancer derived. If they, too, turn out to lack apoptosis genes, it would suggest that the myxosporean loss doesn’t stem from a cancerous past.
Even if, in the end, the data suggest myxosporeans aren’t evolved cancers, Panchin noted that Scandals could still be out there waiting to be discovered. "We are hoping that maybe some zoologists who have been investigating some other peculiar kind of animal at some point will say, ‘Probably those guys are wrong about Myxosporea, but this [animal], he’s obviously a cancer.’"

All Rights Reserved © 2019.

* * *

    Earth.com / 08-19-2019
    Substance found in brown coal can combat tick-borne virus
    • By Olivia Harvey
    Исследовав с помощью методов масс-спектрометрии высокого разрешения и хемоинформатики извлеченные из бурого угля гуминовые вещества, российские ученые обнаружили соединения, обладающие противовирусной активностью. Молекула с фрагментами флавоноидов и полифенолов блокирует размножение вируса клещевого энцефалита.

Scientists have used a combination of high-resolution mass spectrometry and chemoinformatics to identify specific molecular components of humic substances in brown coal, and in the process, found antiviral substances that could combat the tick-borne encephalitis virus.
Humic substances found in coal, soil, and peat, are one of many natural multicomponent mixtures that are important sources of biologically active compounds. And gaining a better understanding of what these mixtures are made of (a challenging task, in itself) can help scientists develop new drugs.
However, the scientists involved in this study were able to reveal that humic substances inhibit the reproduction of the tick-borne encephalitis virus. They were able to come to this conclusion using high-resolution mass spectrometry to analyze the composition of humic samples and chemoinformatics.
Using this analysis, the team was able to compare their results against databases of chemical compounds and were able to identify the compounds’ structure.
These findings were performed by a team of scientists from Russia’s Skolkovo Institute of Science and Technology (SKOLTECH), the M.P. Chumakov Federal Scientific Center for Research and Development of Immune-and-Biological Products of the Russian Academy of Science, and M.V. Lomonosov Moscow State University. The results were published in Scientific Reports.
"We made an attempt at understanding the structural reasons behind the antiviral activity of the molecular components of humic substances," said Alexander Zherebker, PhD, a Research Scientist from SKOLTECH. "Aware that standard methods of complex mixture separation do not work for humic substances, we looked at some known structures matching the molecular compositions determinable by mass spectrometry and noticed that some structures correspond to compounds often extracted from natural sources, for example, flavonoids."
"We undertook further mass spectrometry experiments," he continued, "which suggest that there can indeed be a match between the types of structures we found in the databases and the molecular components of humic systems."
The study’s results are the first in what will be more detailed research into humic substances and how they can be used in a pharmaceutical setting.

© 2019 Earth.com. All rights reserved.

* * *

    Los Angeles Times / Aug. 21, 2019
    Siberia just experienced wildfires on a staggering scale. Russia is rethinking how to fight them
    • By Sabra Ayres
    Четыре года назад в России вышел закон, разрешающий не тушить лесные пожары в отдаленных местах, если в этом нет экономической необходимости. Экологи предупредили, что последствием станет рост интенсивности ежегодных лесных пожаров в Сибири и увеличение выбросов диоксида углерода в атмосферу.
    После того, как этим летом пожарами оказались охвачены тысячи квадратных километров сибирских лесов, а треть территории страны заволокло дымом, правительству придется пересмотреть закон в ближайшее время.

Four years ago, Russia instituted a policy of letting remote forest fires burn unless it made sense economically to put them out.
Environmentalists warned that the new rules would intensify Siberia’s annual fire season and release more greenhouse gases into the air. The public, for the most part, didn’t pay attention to the regulation change.
That changed this summer when fires swept quickly through thousands of square miles of Siberian forest and strong winds spread smoke and ash across a third of the country. For several days, dark clouds blanketed the cities of Novosibirsk and Krasnoyarsk - each home to more than a million people - hundreds of miles from the fires’ epicenter.
Siberians begged the government to ignore the cost efficiency regulations and extinguish the remote fires. Russian President Vladimir Putin finally sent in military planes and helicopters to douse the flames.
Now Prime Minister Dmitry Medvedev has ordered the government to examine the "control zone" burn regulations when parliament meets next month. A change in the policy could have far-reaching benefits in the fight against climate change.
Russia has the largest forested area in the world, covering about 45% of the country. Much of that forest is remote and difficult to reach, which creates unique challenges when battling fires, whether they are in the taiga forests of the Krasnoyarsk region or the Arctic tundra in the republic of Sakha.
The current regulation grants regional authorities the right to decide whether it is economically viable to extinguish a remote fire that does not directly threaten settlements or people. If the cost of putting out these remote fires is greater than the profit that could be made from selling the timber, they can decide to let it burn. But critics say it is irresponsible simply to let remote fires burn, spread and pollute.
"When the law was drafted in 2015, it never occurred to anyone that the wind would be able to bring smoke from the fires so far," said Andrey Sirin, director of the Institute of Forest Science at the Russian Academy of Sciences. "Often the damage to people’s health is much worse than the damage to the economy."
In a petition to the Kremlin calling for a policy change, the environmental group Greenpeace said that "these forests are considered to be sufficiently accessible for logging, but they are also called inaccessible and therefore too hard to extinguish."
Still, experts said that more aggressive firefighting would not solve the underlying issues: a failure of prevention efforts, a lack of sustainable forest management and hotter, drier conditions resulting from climate change.
"The problem is not only the fires this year," said Anton Beneslavskiy, a forest fire expert with Greenpeace International in Moscow. "The problem is that these fires happen every year, and with more intensity. Previously it was one catastrophic fire a year. Now it’s a lot of them and in different parts of the world."
This year’s fires in Siberia have been especially brutal.
According to Russian authorities, they have burned more than 11,500 square miles of Siberian forest, including areas north of the Arctic Circle. Greenpeace disputed those figures, saying the burn area was nearly 21,000 square miles, or nearly three times the size of New Jersey. The group estimates about 90% of the fires occurred in the control zones that the government is now reconsidering. Rains and cooling temperatures in Siberia this month have helped keep the fires in check for the moment, but Greenpeace estimated in mid-August that only 9% had been extinguished and that by the end of the season the burn area could break the 2012 record of nearly 70,000 square miles. It estimated that the fires had already released 138 megatons of carbon dioxide, more than the annual emissions of many countries.
In addition, scientists now believe intense forest fires around the world are increasingly emitting particles known as "black carbon," which are carried by the wind and eventually settle on the earth. Some wind up on Arctic ice sheets, where they soak up sunlight and accelerate thawing.
Hundreds of this year’s Siberian fires were above the Arctic Circle, meaning more particles were expected to land on the ice sheets.
For centuries, starting in the era of czar Peter the Great, Russia cared for its forests through a system of government forest rangers. Often a ranger job would be handed down through generations of a single family.
The system meant close monitoring of forests and, Sirin said, allowed the rangers to quickly extinguish small fires. But a 2006 law ended that system, relying instead on forest tenants, who cover territories 10 times the size of those the rangers monitored and who have very little power and few resources. Beneslavskiy said Russia also needs systemic change to build a sustainable forest industry.
Russia is a global leader in forest depletion - a significant cause of global warming - in large part because of China’s seemingly insatiable appetite for Russian lumber.

Copyright © 2019, Los Angeles Times.
* * *
    Phys.org / August 22nd, 2019
    Bat Swarming in Eastern Siberia Has Been Studied for the First Time
    Тюменские и иркутские ученые опубликовали результаты масштабного исследования летучих мышей в карстовых пещерах Байкальского региона. Впервые описано такое явление, как сворминг или «роение» - массовый сбор летучих мышей у входа в пещеры в конце лета и начале осени. До недавнего времени данные по свормингу были представлены только для рукокрылых Европы и Северной Америки..

Siberia is a remote and mysterious region that can be quite difficult to explore. Siberian bats are small and secretive and therefore even more difficult to study. A team of Russian scientists including a representative of Tyumen State University managed to study bat swarming in the Baikal region for the first time. The work was published in the Acta Chiropterologica journal.
Bats are the creatures of folklore and myths, but in reality, we know little about these nocturnal animals, mainly because they are extremely difficult to study. They are almost invisible in the night time and can be heard only with special devices. One of the most efficient methods to collect the data on bats is the use of nets made of thin but strong nylon threads. The animals get tangled in them, and after that, they can be examined, weighed, and released. No damage is done to the animals in the process. To obtain the most accurate data, the bats should be caught in large quantities which is extremely difficult. Bats actively fly around in the night time and don't have specific routes. Therefore, the places for setting up the nets should be chosen carefully.
The best time to collect information about bats is the swarming season when the bats gather at the entrances of caves in large masses. They fly in and out, and a part of them gets caught in the nets. This method was used by the Russian scientists to study bat swarming in the Baikal region for the first time. The extensive study took place in 2015-2017. Within this period of time, the team studied three Siberian caves: Mechta (in July), Dolganskaya Yama (in August and September) and Okhotnichya (in September). Unfortunately, solutional caves are hard to access, and the climate in the region is harsh, therefore it was impossible to carry out the study all the swarming season. The researchers caught over 1,500 bats, identified their species, sex, age, and weight. 85% of seven species of caught bats were Siberian long-eared bats (Plecotus ognevi). Others included northern, long-tailed, Ikonnikov's, Siberian, and Siberian tube-nosed bats.
Males were caught more often, as females are occupied with rearing young bats during summer and start their migration to the swarming sites later. The balance of males and females is established only by the end of the swarming season and is considered a sign of forthcoming hibernation. The age structure also changed over time. Young animals were rare in August, but by September their share reached up to 30%. This is due to the fact that young bats do not participate in the breeding process and therefore migrate to swarming sites later than the adults.
It is not entirely clear why bats gather at cave entrances. However, the majority of studies suggest that swarming sites act as hotspots of gene flow, i.e. main function of swarming is mating. Caves may also be resting points along bat migration routes. It is also possible that adult females swarm to lead young bats to hibernation sites.
"We expect to expand our understanding of autumn swarming in Eastern Palaearctic. We would also like to study spring bat swarming that has previously been observed only in Europe. We might use radio transmitters to monitor the animals. It could help us understand how long they stay at swarming sites and what summer roosts they use. We plan to study the population structure of some species using molecular and genetic methods" said Denis Kazakov, master student of the Institute of Biology, Tyumen State University.
Among the participants of the work, there were scientists from Tyumen State University and Irkutsk State Medical University and employees from Federal State Budgetary Institution "Zapovednoe Pribaikalye" (Irkutsk) and Center of Children's Complementary Education and Evenkis' Folk Crafts.

© Phys.org 2003-2019 powered by Science X Network.
* * *
    La Nouvelle République / le 27/08/2019
    Le vaisseau transportant le robot russe Fedor s'est arrimé à l'ISS
    Со второй попытки «Союз МС-14» с антропоморфным роботом «Федором» пристыковался к МКС. Андроид был создан для того, чтобы работать в опасных для людей условиях; одна из его функций - способность дистанционно повторять движения человека, одетого в специальный костюм-экзоскелет. Эксперимент в космосе позволит оценить работу этой функции в условиях невесомости.

La deuxième tentative a été la bonne : un vaisseau spatial Soyouz transportant le premier robot humanoïde russe, Fedor, s'est arrimé avec succès mardi à la Station spatiale internationale (ISS), après un premier essai infructueux ce weekend.
"Mes excuses pour le retard. J'étais dans les bouchons. Je suis prêt à poursuivre le travail", peut-on lire dans un message sur un compte Twitter créé pour le robot. Capable d'imiter les mouvements humains, Fedor aura pour fonction d'aider les cosmonautes à réaliser leurs tâches sans pouvoir toutefois se déplacer librement dans la station.
Après un premier essai d'arrimage, l'équipage de l'ISS avait dû déplacer lundi un autre vaisseau Soyouz, déjà arrimé, d'un module à un autre pour que la capsule transportant le robot puisse faire une nouvelle tentative.
Le Soyouz MS-14 avec Fedor à son bord s'est fixé avec succès à l'ISS à 03H08 GMT, a annoncé l'agence spatiale russe Roskosmos.
Un commentateur sur Nasa TV, la chaîne de télévision de l'agence spatiale américaine, qui diffusait l'arrimage en direct, a relevé "l'approche parfaite vers l'ISS".
Pendant une vidéo-conférence avec les deux cosmonautes russes à son bord, le président Vladimir Poutine a quant à lui évoqué une "situation anormale" mais salué "un travail réalisé avec brio".
"J'espère que le robot Fedor vous apportera toute l'aide nécessaire", a-t-il ajouté, cité par les médias russes, du salon aéronautique MAKS, près de Moscou, où il était en visite avec son homologue turc Recep Tayyip Erdogan.
Le vaisseau avait décollé jeudi du cosmodrome russe de Baïkonour, au Kazakhstan. Il transportait également de l'équipement scientifique et médical, des vivres, des médicaments et des produits d'hygiène, selon Roskosmos.
"Défaillances radio"
Fedor (acronyme de Final Experimental Demonstration Object Research) est un robot au corps anthropomorphe argenté qui mesure 1,80 m de haut et pèse 160 kg. Portant le numéro d'identification Skybot F850, il est le premier engin de ce type envoyé dans l'espace par la Russie.
Il doit séjourner dans l'ISS jusqu'au 7 septembre pour un vol-test avant des missions plus risquées. Ses opérations l'amèneront à manier un tournevis ou encore des clés et à tester ses capacités en conditions de très faible gravité.
Selon le directeur de Roskosmos, Dmitri Rogozine, les prochaines étapes seront une sortie du robot dans l'espace, ainsi que son essai au sein du nouveau vaisseau russe Federatsia, dont les premiers vols sont prévus pour 2020.
L'échec samedi de la première tentative d'arrimage du Soyouz avait constitué un nouveau revers pour le secteur spatial russe, qui a subi ces dernières années une série d'accidents et de scandales de corruption.
La Nasa avait déclaré samedi que le Soyouz de Fedor "n'avait pas pu se verrouiller" et "s'était éloigné à une distance de sécurité" de l'ISS, dans l'attente des directives des contrôleurs de vol russes.
Selon le responsable du segment russe de la station, Vladimir Soloviov, le problème qui a empêché le premier arrimage était dans l'ISS et non dans le Soyouz. Il a mis en cause des "défaillances de l'équipement radio" qu'"il est possible de corriger".
"Conquérir l'espace lointain"
En octobre, la Russie avait dû faire face au premier échec dans l'histoire des vols habités à bord de la station internationale lorsqu'un vaisseau Soyouz à bord duquel se trouvaient un astronaute américain et un cosmonaute russe avait été forcé d'effectuer un atterrissage d'urgence peu après son décollage.
Fedor n'est pas le premier robot à avoir quitté la Terre.
En 2011, la Nasa a envoyé dans l'espace un robot humanoïde baptisé Robonaut 2, mis au point en coopération avec General Motors, avec le même objectif de le faire travailler dans un environnement à haut risque. Il est revenu en 2018 en raison de problèmes techniques.
En 2013, le Japon, à son tour, a expédié un petit robot, en même temps que le premier commandant japonais de l'ISS, Koichi Wakata. Mis au point avec Toyota, Kirobo était capable de parler, mais uniquement en japonais.
Malgré les récents échecs, la Russie reste le seul pays en mesure de transporter des humains vers la station internationale. Elle cherche depuis des années à redresser son industrie spatiale, source d'une immense fierté à l'époque soviétique, mais qui s'est retrouvée ruinée après la chute de l'URSS.
En août, le directeur de l'agence spatiale russe avait expliqué vouloir utiliser à l'avenir des machines comme Fedor pour "conquérir l'espace lointain".

* * *
    Nature / 30 August 2019
    How nuclear scientists are decoding Russia’s mystery explosion
    Isotopes that caused a radiation spike earlier this month probably came from an exploding nuclear-reactor core - but device’s application is still unknown.
    • Elizabeth Gibney
    Журнал Nature опубликовал анализ доступной информации о причинах взрыва на военно-морской базе в Архангельской области 8 августа, в результате которого погибли пятеро ученых и произошел выброс гамма-излучения.

Rumours continue to swirl about a blast at a Russian naval base on 8 August, which killed five scientists and caused a short, unexplained spike in γ-radiation.
Information has been slow to emerge and confused by conflicting reports, but this week, Russia’s weather agency, Roshydromet, finally revealed details about the nuclear radiation that was released.
The information suggests that a nuclear reactor was involved in the blast, which lends weight to the theory that Russia was testing a missile known as Burevestintnik, or Skyfall. President Vladimir Putin told Russia’s parliament in 2018 that the nation was developing the missile, which is propelled by an on-board nuclear reactor and could have unlimited range.
But because official information about the cause could be scarce, independent researchers are finding ways to glean more details about the explosion.
Nature examines the growing evidence.
What have official sources said about the blast?
The explosion happened at a military facility in northwestern Russia’s Arkhangelsk region. The region is home to Nenoksa, one of the Russian Navy’s major research and development sites. A day after the blast, Russia’s nuclear agency, Rosatom, said that an accident happened during "tests on a liquid propulsion system involving isotopes" and later added that the incident happened on an offshore platform.
Meanwhile, Roshydromet reported a brief spike in γ-radiation at 16 times the normal level in the city of Severodvinsk, around 30 kilometres east of Nenoksa.
On 26 August, Roshydromet revealed the isotopes found in rain and air samples: strontium-91, barium-139, barium-140 and lanthanum-140.
What do we know about the scientists who died?
Rosatom named the dead scientists as Alexei Viushin, Evgeny Kortaev, Vyacheslav Lipshev, Sergei Pichugin and Vladislav Yanovsky. It’s not clear whether they were killed when thrown off the sea platform, or after being exposed to radiation.
Few details are known about the scientists’ research, which took place at the All-Russian Scientific Research Institute of Experimental Physics in Sarov. Viushin was a member of the ALICE collaboration at CERN, Europe’s particle-physics laboratory near Geneva, Switzerland, until at least 2016.
What do the isotopes tell us?
The detected isotopes of barium, strontium and lanthanum would be created in the core of a nuclear reactor, which produces energy by splitting uranium atoms in a chain reaction. These isotopes would have been released if a core exploded, says Claire Corkhill, a nuclear scientist at the University of Sheffield, UK.
Any damage an explosion might have caused to the reactor core would probably have led to the release of radioactive iodine and caesium, says Marco Kaltofen, a nuclear scientist at the Worcester Polytechnic Institute and the environment investigation firm Boston Chemical Data Corp, both in Massachusetts. An uncorroborated report in The Moscow Times on 16 August said that local doctors had traces of caesium-137 in their muscle tissue. And a Norwegian nuclear authority detected an unexplained spike in radioactive iodine-131 almost 700 kilometres away in Svanhovd after the blast. But this could be from another source: iodine-131 can be released in small quantities during the production of radionuclides for medical purposes, says Corkhill.
Boris Zhuikov, head of the Laboratory of Radioisotope Complex at the Institute for Nuclear Research of the Russian Academy of Sciences in Moscow, has an alternative explanation. His calculations show that if an explosion damaged the housing of a nuclear reactor, rather than the core, and caused a leak of radioactive noble gases - which are a product of fission - then by the time the nuclei reached the detector in Severodvinsk they would have decayed to leave precisely the isotopes observed.
But Kaltofen cautions that circumstantial evidence points to damage to a reactor core.
Does this mean that Russia was testing a nuclear-powered missile?
Some experts think so. Powering a missile is a plausible use for the huge amount of energy generated by nuclear fission, says Corkhill. Little is known about the Burevestintnik missile, but experts speculate that it could use liquid propellant to become airborne, then use a compact nuclear reactor to heat air that gets fired out the back to sustain flight - potentially for days.
Satellite images of Nenoksa taken hours before and after the blast also strongly point to a missile test, says Anne Pellegrino, a researcher at the James Martin Center for Nonproliferation Studies in Monterey, California. The images show launch infrastructure in Nenoksa that was also present at another site known to be associated with testing a nuclear-powered missile, she says. "The existence of that ship off the coast is a huge indicator," she says.
What else could it be?
A nuclear-fission device could be part of a number of military nuclear-energy projects, says Michael Kofman, a researcher and Russia specialist at the non-profit research and analysis organization CNA and a fellow at the Wilson Center, both in Washington DC.
Kofman believes there is cause to doubt the Burevestintnik theory. He reasons that to be light enough to fly on a missile, the propulsion reactor would probably have no shielding, putting anyone around it at risk during its use. "It doesn’t make sense that Russian scientists would be standing around any sort of reactor that was being tested without adequate shielding in place," he says. These missiles are also usually tested on land-based launchers, rather than platforms at sea, and such a test facility is visible on the coast, he adds.
This leads Kofman to deduce that the device was probably not a propulsion system for a missile. Other options include a nuclear-powered torpedo, a pressurized underwater nuclear reactor for powering undersea infrastructure, or a small reactor for space applications, he says.
What are researchers investigating?
Kaltofen is attempting to source objects such as car air filters from people who live near the blast area, to examine any radioactive elements on them. His team will compare this information to analyses of other objects irradiated by known sources, such as Japan’s Fukushima Daiichi nuclear power plant, which released significant amounts of radiation after it was damaged by an earthquake in 2011.
With enough filters, the method could work, says Corkhill, but they will need to be tested soon, before the radioactive isotopes decay.
Pellegrino’s team will look more closely at the scientists who died. The researchers will analyse the scientists’ social media, scientific publications and conference presentations, which could reveal clues about what they were working on.
The Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO), an international agency that detects nuclear-bomb tests, might also have data. It has eight stations across Russia that monitor radionuclides - but five of these had outages in the days after the blast, fuelling speculation that secretive weapons were involved. Two reporting stations have come back online and begun to backfill data, a CTBTO spokesperson told Nature.
Does the radioactivity pose a danger to the public?
The risk is low, says Zhuikov. The initial spike in γ-radiation was 16 times above background levels; by comparison, γ-radiation was 7,000 times above background levels after the 1986 reactor meltdown at Chernobyl.

© 2019 Springer Nature Publishing AG.
* * *
    Science / 30 Aug 2019
    Science diplomacy leverages alliances to build global bridges
    • Anne Q. Hoy
    Центр научной дипломатии при Американской ассоциации содействия развитию науки (American Association for the Advancement of Science, AAAS) был создан в 2008 г. с целью использования научного сотрудничества для налаживания устойчивых связей со странами, в политических отношениях с которыми имеются проблемы.
    16 июля в Вашингтоне прошел симпозиум «US-Soviet Scientific Cooperation: Lessons for Science Engagement», организованный Центром и посвященный истории советско-американского сотрудничества в годы холодной войны как «наилучшего примера научного взаимодействия между странами, имеющими сложные дипломатические отношения».

Nobel laureate and theoretical physicist Kip Thorne counts his decades-long collaboration with Russian experimental physicist Vladimir Braginsky as pivotal to scientific research that led to the first detection of two colliding black holes in the distant universe.
The 2015 detection of gravitational waves by the Laser Interferometer Gravitational-Wave Observatory (LIGO) was not only the birth of a whole new way of studying the universe, a realization predicted by Albert Einstein's general theory of relativity, and a discovery that earned Thorne and two other physicists the 2017 Nobel Prize in Physics. It also validated the enduring benefits of science diplomacy across the globe.
"Braginsky was my principal mentor on research at the interface between theory and experiment. His mentoring made possible many of my contributions to LIGO, and our tight collaboration led to his own major LIGO contributions," said Thorne. "He became the ‘conscience’ of LIGO in the 1990s and 2000s, identifying a series of sources of noise that we had not been aware of, and triggering the LIGO Scientific Collaboration to scope out those noise sources and devise ways to deal with them."
Thorne and Braginsky, who died in 2016, traveled to each other's laboratories, coauthored scientific papers, shared findings, traded questions, and formed a lasting friendship that began with Thorne's first visit to Braginsky's lab in 1968 and extended into the 2000s.
As scientists forged such cooperative relationships despite tensions between their governments, the American Association for the Advancement of Science (AAAS) was pioneering efforts to spread the global reach of science and technology by engaging in scientific leadership initiatives through international exchanges and scientific partnerships.
In 2008, AAAS formally established the Center for Science Diplomacy to advance the value of what then AAAS CEO Alan I. Leshner described as a program "guided by the overarching goal of using science and scientific cooperation to promote international understanding and prosperity. AAAS believes this use of scientific collaboration and communication is essential both to the advancement of science and its use for the benefit of our global society." Leshner is now serving as AAAS's interim CEO.
At the center's opening, Vaughan Turekian, then AAAS's chief international officer, said the center would "contribute to the long and methodical building of relationships" and pursue advances to address global challenges such as climate change, sustainability, and health care innovation.
A year later, AAAS joined five representatives of other leading scientific organizations in a meeting with North Korea's State Academy of Science. During the rare visit, U.S. scientists met with their counterparts, toured government research institutions, and reached an agreement to pursue cooperative issues that paved the way for a reciprocal visit of North Korean scientists to U.S. laboratories.
AAAS has continued to develop such scientific agreements, including a 2013 agreement with China's Association for Science Technology, a 2014 pact between AAAS and the Cuban Academy of Sciences, a 2017 agreement with Mexico's Presidential Science Advisory Council, and a 2018 agreement with the Science Commission of Chile's Senate.
It also has tapped into long-standing collaborations to offer training sessions and expand global scientific alliances. Last year, for instance, AAAS held a regional training workshop with The World Academy of Sciences and the Academy of Science of South Africa to introduce regional scientists to scientific collaborations that inform science and advance diplomacy.
The AAAS Center for Science Diplomacy also provides training for scientists and graduate students in the U.S., and, since 2014, it has cohosted international sessions with The World Academy of Sciences at its headquarters in Italy.
Throughout the ebb and flow of relations between the United States and the Soviet Union, then Russia, scientists, like Thorne, continue to build professional relationships and keep in touch with their foreign counterparts.
"The Cold War Iron Curtain was not a significant barrier to my collaborations with Braginsky and other Russian scientists," said Thorne. "I hope the soaring paranoia in Washington about China does not create major barriers to the very fruitful collaborations that my colleagues today have with Chinese scientists."
The parallel with China was not raised during a 16 July AAAS symposium hosted by the AAAS Center for Science Diplomacy that centered on the history of U.S.-Soviet scientific activities. In examining scientific interactions between the two powers, Gerson S. Sher, author of From Pugwash to Putin: A Critical History of US-Soviet Scientific Cooperation and former coordinator of the National Science Foundation's U.S.-Soviet and East European program, used the U.S.-Soviet relationship as a case study of what drives, benefits, and sometimes interrupts international scientific collaborations.
Today, six decades of formal bilateral exchanges between U.S. and Soviet scientific academies have "all but descended to zero," after Russia's annexation of the Crimean Peninsula and its intervention in the Ukraine crisis in 2014, said Sher during the symposium held at AAAS's Washington, D.C., headquarters.
Sher walked through earlier collaborations during post–World War II, post–Joseph Stalin and post-Soviet periods to demonstrate that despite any strained relations between governments, scientific cooperation endures in strengthening civil relationships, improving understanding of each society, and advancing science.
Among early U.S. collaborations was President Dwight D. Eisenhower's "people to people" exchange initiative. Backed by private sponsors, it amplified the scientific communities' prevalence to nurture relationships with fellow researchers. This led to the emergence of multiple public and private scientific efforts designed to support international scientific alliances in the wake of the Soviet Union's demise in 1991.
The U.S. National Science Foundation, for instance, established the nonprofit U.S. Civilian Research and Development Foundation (CRDF) in 1995 to provide scientists grants, technical resources, and training support for global scientific and technical collaborations. Sher served as its founding president.
CRDF's emergence came amid heightened U.S. concerns about unsecured weapons of mass destruction and set off calls for nonproliferation programs, said Sher. Particularly unsettling was the sidelining of Russian nuclear weapons experts under the weight of a stagnant Soviet economy and amid the chaotic fallout of the Soviet Union's collapse.
In remarks at the AAAS symposium, Cathleen A. Campbell, who also served as a CRDF president beginning in 2006, underscored the importance of such nongovernmental organizations in fostering scientific collaborations through science and technology agreements between the United States and the former Soviet Union and its republics.
"That was a unique period in history that I don't think we will ever see again anywhere," said Campbell, a former visiting scholar at the AAAS Center for Science Diplomacy and now a board member of the U.S.-Israel Bilateral Science Foundation. "It's just an incredible interconnection of opportunities and challenges and issues we were facing that prompted this whole array of programs."
Turekian, now executive director of policy and global affairs at the National Academies of Sciences, Engineering, and Medicine, said the Cold War had a profound impact in shaping science diplomacy, then and today.
"The creation of the AAAS Center for Science Diplomacy was a response to the need to refocus how science and science cooperation could be better utilized as a bridge outside of a polar world and to deal with complex issues at regional and global scales," said Turekian. "But it also looked to the U.S.-USSR science diplomacy experiences to understand how to make science diplomacy work."

© 2019 American Association for the Advancement of Science. All rights reserved.
* * *

январь февраль март апрель май июнь июль август сентябрь октябрь ноябрь декабрь

предыдущий месяц
1998-2019
следующий месяц
[О библиотеке | Академгородок | Новости | Выставки | Ресурсы | Библиография | Партнеры | ИнфоЛоция | Поиск | English]
  Пожелания и письма: branchl@gpntbsib.ru
© 1997-2020 Отделение ГПНТБ СО РАН (Новосибирск)
Статистика доступов: архив | текущая статистика
 

Документ изменен: Fri Sep 20 12:45:36 2019. Размер: 75,956 bytes.
Посещение N 316 с 19.09.2019