Сентябрь 2023 г.

Российская наука и мир (по материалам зарубежной электронной прессы)

CONTENTS / ОГЛАВЛЕНИЕ


• Study reveals new insights into Siberia’s Por-Bazhyn
• Challenging assumptions: Scientists unearth untold technological secrets of Neanderthals
• Researchers aim to teach a neural network to identify fatigue from PC users
• Researchers report on the atmosphere of hot Jupiter HD 189733b
• Revamped research grants aim to entice scientists to Russia
• Russian scientists develop better protection for fusion reactor walls
• Near-surface permafrost could be nearly gone by 2100, scientists conclude
• Breakthrough: Ural scientists introduce innovative method for bauxite processing
• Fern saves fish from microbes and leeches

Глиняная крепость Пор-Бажын, построенная в 777 г. на острове посреди высокогорного озера Тере-Холь в Туве, должна была стать манихейским монастырем. К такому выводу пришли исследователи Российского географического общества. В 762 г. правитель Уйгурского каганата Бегю-каган утвердил манихейство в качестве официальной религии, однако был убит в результате переворота в 780 г., после чего только что построенная крепость оказалась заброшена.

Por-Bazhyn, meaning "Clay House" in the Tuvan language is located in the Sengelen mountains of southern Siberia, Russia.
Approximately 30 buildings stood within the interior, centred on a central complex consisting of two pavilions that likely served a ceremonial and religious purpose, with various one or two chamber structures located in each of the smaller enclosure courtyards.
The lack of archaeological material has led to various interpretations as to the function of Por-Bazhyn, including a border fortress, a fortified palace, and an astronomical observatory.
Por-Bazhyn has been known since the 18th century and was first explored in 1891. Radiocarbon dating and dendrochronological studies indicate that Por-Bazhyn was built around AD 777, with previous excavations associating the site with the Uyghurs based on comparisons with the palace complex of Karabalgasun (the capital of the Uyghur Khaganate).
A Chinese influence has also been suggested as the layout of the central complex of the site appears to be in the Tang style. This interpretation was further supported by the use of Chinese construction methods, such as the hangtu technique and dougong ceilings, and the presence of Chinese-type building materials.
According to an announcement by the Russian Geographical Society, Por-Bazhyn was built to serve as a Manichean monastery for the study of Manichaeism, a former world religion founded in the 3rd century AD by the Parthian prophet, Mani (AD 216-274).
During the AD 770s, the Uighur Empire under the rule of Bögü Khagan, embarked on a religious transformation to embrace Manichaeism. However, this reform was halted in AD 779 with a counter-Manichean uprising, resulting in Por-Bazhyn being abandoned following the death of Bögü Khagan.
"If the monastery was built on the eve of the coup, then the previous rulers simply did not have time to use it, and for the new one it was no longer needed," said Andrei Panin, deputy director of the Institute of Geography of the Russian Academy of Sciences.

Французские, бельгийские и российские ученые опубликовали результаты исследования находок, сделанных на неандертальской стоянке Ше-Пино возле французского города Жонзак. Найденные там многочисленные и разнообразные костяные орудия доказывают, что неандертальцы отлично умели их мастерить, не ограничиваясь лишь кремневыми инструментами. Кроме того, у них были свои методы изготовления, отличавшиеся от приемов Homo sapiens.

Were anatomically modern humans the only ones who knew how to turn bone into tools? A new discovery at the Chez-Pinaud-Jonzac Neanderthal site by an international research team puts this question to rest. Published in the journal PLOS ONE, the findings illuminate a little known aspect of Neanderthal technology.
Starting from 45,000 years ago, anatomically modern humans began to appear in Western Europe, eventually replacing the last remaining Neanderthal communities. This period also marked significant shifts in material culture, notably the introduction of a wide array of bone artifacts - ranging from hunting tools and decorative ornaments to intricately carved figurines - by modern human groups.
Their absence from Neanderthal sites has led to the assumption that these groups did not produce bone tools and implements, sometimes inferred to reflect cognitive differences between the two populations. Since Neanderthals did not know how to process this raw material, they were limited to picking up bone fragments amongst butchery remains, using them uniquely as retouchers for shaping flint tools.
New excavations at the Neanderthal site of Chez-Pinaud-Jonzac (Charente-Maritime), carried out by an international team since 2019, have made it possible to reconsider this assumption. Current studies have shown that bone tools are as numerous as flint ones. Moreover, their diversity provides evidence for a genuine industry that consists not only of retouchers but also of cutting tools, scrapers, chisels, and smoothers, used for various activities and on multiple materials.
These bone tools are identifiable based on traces of manufacture and use present on their surfaces as well as within the tools themselves using X-ray microtomography. Unlike examples made by modern humans that are generally shaped by scraping and abrasion, these tools were primarily made by percussion.
The discovery of a bone industry at Chez-Pinaud-Jonzac is consistent with evidence uncovered a few years earlier by the same team at the Neanderthal site of Chagyrskaya, in the Siberian Altai. These two sites, located on either side of the Neanderthal range, testify to the fact that, like modern humans, Neanderthal made and used bone tools for their daily needs. They had the know-how to process bone using their own techniques and for their own purposes. Bone tools represent a new means for exploring and understanding Neanderthal technology, which has apparently not yet revealed all its secrets.
The study was funded by Marie Sklodowska-Curie Actions, the Russian Science Foundation, the Russian Foundation for Basic Research, the Fondation Maison des Sciences de l’Homme, the Ministère de la Culture, and the European Research Council.

Петербургские специалисты научили нейросеть распознавать признаки усталости у пользователей компьютеров. В дальнейшем это планируется использовать для обеспечения безопасности и отслеживания состояния операторов, диспетчеров, водителей и т. д.

A team of researchers from St. Petersburg University, the St. Petersburg Federal Research Center of the Russian Academy of Sciences, and some other institutions have devised a comprehensive database cataloging eye movement patterns in individuals operating PCs under various conditions, such as tiredness and alertness.
Drawing insights from this data, the scientists intend to train neural network models that will serve as the foundation for highly accurate systems monitoring an individual's functional state. These systems aim to bolster safety measures in domains like transportation and industrial facilities.
Integrated Approach
Various transport, industrial, and defense systems rely on operators and professionals at central hubs. The effectiveness and safety of these critical facilities are closely linked to the psychological and physiological well-being of these human operators.
According to the research team, this system could be particularly valuable for professionals like drivers, pilots, air traffic controllers, and industrial supervisors.
Irina Shoshina, a Doctor of Biological Sciences and Professor at the Institute for Cognitive Research at St. Petersburg State University, highlighted the value of this integrated approach, noting its capacity to offer a more holistic and objective assessment of an individual's functional state compared to methods that involve isolated measurements of specific indicators linked to fatigue.
Shoshina explained: "An integrated approach provides a more complete picture and a more objective assessment of the functional state, in contrast to approaches involving separate registration of certain indicators that reflect the state of fatigue."
"Thus, a common method of cardiac time interval measurement used to register fatigue is quite controversial in terms of the accuracy of state assessment. It is based on the registration of heart rate indicators," she added.
Instead, the team adopted a unique approach focused on analyzing eye movement patterns, which, according to Shoshina, reflect the interplay between the neural networks responsible for static and dynamic vision, psychophysiological markers of functional state, and psychological test results.
The next step for the scientists is to harness this database to train a neural network capable of accurately detecting operator fatigue based on their eye movement patterns.
Shoshina believes this approach will facilitate remote fatigue assessment. Moreover, their compiled database is available to all software developers, offering them a valuable resource for testing their offerings.
Extensive Database
Alexey Kashevnik, the Project Manager and Senior Research Associate in the Laboratory of Integrated Automation Systems at the St. Petersburg Federal Research Center of the Russian Academy of Sciences, claims they have crafted an extensive database.
This database is well-suited for training neural networks to categorize an individual's condition as either fatigue or alert. It contains a distinctive array of diverse labeled indicators that can be employed to instruct neural networks in accurately identifying human fatigue levels.
The researchers gathered data on functional state indicators through various sensors, including a video camera, eye tracker, heart rate monitor, and electroencephalograph. Furthermore, participants were subjected to assessments of sleep quality, fatigue levels, complex visual-motor reaction tests, and more.
These measurements were taken at different times over an eight-day research period involving 10 individuals engaged in both passive and active tasks. The findings of the team were recently published in the journal Sensors.

Ученые из Института лазерной физики СО РАН смоделировали атмосферу «горячего Юпитера» - экзопланеты HD 189733b, известной своими экстремальными погодными условиями, в частности, ветром со скоростью 2 км/с и дождями из расплавленного стекла. С помощью многокомпонентной трехмерной модели физики вычислили вероятные причины нестабильного обнаружения водорода в атмосфере газового гиганта, а также определили физико-химические свойства этой планетной системы.

Scientists from the Institute of Laser Physics of the Siberian Branch of the Russian Academy of Science have modeled the atmosphere of the well-known "hot Jupiter" HD 189733b and have learned what hindered a stable finding of hydrogen in the atmosphere of the planet. They also defined the physico-chemical properties of this planetary system. They presented on this topic at the symposium of Asian Pacific Geophysical Society in August 2023, and the work is published in The Astrophysical Journal.
Exoplanets are planets beyond the solar system. The most studied of them are from the family of so-called hot Jupiters. They can be compared with Jupiterian exoplanets as far as size and weight is concerned, but orbit their stars 10 times nearer than Mercury orbits the sun.
Such close distance and high temperatures cause atmosphere to escape from planets with ultrasonic speed, and the movement of the atmosphere, and also its content, can be studied with the help of method of transit spectroscopy. This method consists of registration of absorptions of stellar radiation by the planet's atmosphere and enables definition of which elements are present in the atmosphere, allowing researchers to make conclusions about speed and density of various elements.
HD 189733b has attracted researchers and observation time of telescopes for less than a decade. The planet became popular due its blue color, caused by glass (silicate) rains - particles of silicates raised into the atmosphere. One of the most interesting mysteries of this planet was "disappearing" transit in the hydrogen line Lyα - measurements of absorptions in this diapason of wavelength turned out to be rather inconsistent.
A bit clearer is the situation with the IK-line of metastable helium 1083 nm - transit in its locality was observed twice, but with different amplitude. Such changes suggest substantially different regimes of the outflow of planetary matter of HD 189733b, and computer modeling is the most available way of investigating possible causes of changes.
One of the most advanced instruments for modeling of complex of features in the atmosphere of exoplanets and interpretation of transit absorptions in the world was created and developed by scientists from the Institute of Laser Physics.
Having applied it to HD 189733b, scientists found that the most probable cause of unstable absorptions in the hydrogen line Lyα is high activity of the host star, which appears in an increase of radiation flux in the ultraviolet area (FXUV, erg∙cm-2с-1Å-1 for 1 АЕ) and the speed of loss of mass of stellar material. It was discovered that changes in those factors can cause not only variable detections of transit absorption in the hydrogen line due to formation of energetically neutral atoms in strong stellar wind, but also different absorptions in the line of metastable helium.

Минобрнауки России предлагает обновить программу мегагрантов и увеличить объем и условия государственной поддержки научных исследований. Планируется, что размер грантов вырастет с 30 млн рублей в год до 100 млн в течение срока действия гранта, который составит от трех до пяти лет (сейчас грантовая программа рассчитана на два года). Таком образом власти рассчитывают вернуть покинувших Россию ученых. Кроме того, впервые гранты будут предоставляться молодым исследователям - 15 млн рублей в год сроком до двух лет.

The Russian Ministry of Science and Higher Education is proposing to update the mega-grants programme and increase the maximum amount and terms of state support for scientific research under the guidance of leading scientists.
It is planned that the value of the grants will grow from RUB30 million (US$316,600) to RUB100 million (US$1 million) per year for the duration of the grant period which ranges from three to five years. According to the Russian authorities, this increase could attract scientists who have previously left Russia.
So far, the Ministry of Science and Higher Education has prepared a draft government decree to update the mega-grants programme aimed at creating world-class research laboratories in Russian universities and scientific organisations under the guidance of leading scientists, primarily foreign citizens and compatriots living abroad.
Currently, the grant programme only runs for two years.
The grants will be allocated to projects determined by the grants board. In addition, the funds can also be received for projects led by leading scientists who decide to move permanently to the Russian Federation or stay in the country for at least six months.
The programme also provides for the allocation of grants to support research in priority areas of scientific and technological development - up to RUB50 million per year for up to five years and RUB30 million per year with a grant extension for up to three years.
Early career researchers
In a first for Russia, grants will also be provided for promising young researchers: RUB15 million per year for up to two years with the possibility of an extension for another two years.
The project stipulates that two categories of researchers will be able to participate in the updated programme: leading scientists and young scientists up to 35 years of age.
A prominent academician of the Russian Academy of Sciences, Alexei Khokhlov, said in an interview with the Russian Kommersant business newspaper, it is expected the competition among young university researchers for these grants will be high.
"As for leading scientists, funding of new university research laboratories offered by the project may be attractive both for Russian scientists who would like to start research in a new scientific field, and for foreign ones, especially for those who cannot continue research in their country due to age-related restrictions," he said.
Competitions for such grants have been held by the Russian government since 2010. Applications were last accepted from December 2021 to the end of January 2022. Based on the results, the grants council announced 30 recipients.
Later, in September last year, the Ministry of Science and Higher Education proposed to allow grant recipients to change the list of foreign partners for joint research. This was because foreign organisations began to withdraw from participation in international projects for which grants had already been allocated. The list of research participants was adjusted to include organisations from friendly or neutral countries.
‘Comfortable’ relocation
According to an official spokesman of the Russian Ministry of Science and Higher Education, despite the current geopolitical situation, in 2022, more than 50 leading scientists from 25 countries were attracted from abroad as part of the mega-grants programme, including scientists from China, India, Serbia, Egypt, the US, Australia and other countries.
The spokesman also said that the programme will help to create conditions for the comfortable relocation of foreign scientists, as it will provide assistance in obtaining visas, medical insurance, invitations for family members, payment for accommodation and travel, etc.
In the meantime, representatives of leading Russian universities have supported the new initiative.
According to Inna Shevchenko, rector of Southern Federal University, one of Russia’s leading universities, the creation of laboratories, which will be led by foreign scientists who are recognised authorities in their fields, will allow Russia to achieve some significant results.
"These include neurotechnologies in robotics, and projects for soil conservation and restoration. And, of course, in modern conditions, the development of international scientific collaborations, which becomes possible thanks to mega-grants, gains additional importance. Such projects show that Russian resources and competencies are of great value to colleagues from all over the world," said Shevchenko.

Ученые Института физической химии и электрохимии имени А.Н.Фрумкина РАН и Национального исследовательского ядерного университета МИФИ разработали технологию защиты стенок термоядерных реакторов от потоков плазмы с помощью жидкого лития на медно-вольфрамовой подложке.

Researchers at Russia’s AN Frumkin Institute of Physical Chemistry & Electrochemistry of the Russian Academy of Sciences (IPCE-RAS) and the National Research Nuclear University (NRNU) MEPhI [Moscow Engineering & Physics Institute] have developed a technology to protect the walls of fusion reactors.
In tokamaks, plasma is held in place by a magnetic field, but plasma flows can still come into contact with the reactor wall causing damage. The heated wall material is therefore sprayed with a protective coating but this can enter the plasma as an impurity. As a result, the plasma cools, which can interfere with nuclear fusion.
The "sweat wall" concept involves covering the inside of the reactor with a network of channels from which liquid lithium flows. The nuclei of such a light element hardly cools the plasma. The material for the "sweating" wall must be refractory and thermally conductive and must not enter into chemical interaction with liquid lithium.
"The choice of material for plasma-facing elements is still a matter of scientific debate. Testing of various materials and methods of their conjugation, as well as protective coatings, is now being carried out," said Vladimir Dushik, head of the laboratory of heterogeneous synthesis of refractory compounds at IPCE-RAS.
Scientists from the two Russian institutes therefore proposed using a chemical vapour deposition method to combine the properties of two metals, tungsten and copper.
"Tungsten, with its record high melting and boiling points, can withstand high thermal loads and does not interact with liquid lithium," explained Dushik."In the form of a coating on copper, tungsten shows higher efficiency due to the significantly higher thermal conductivity of copper. The solution is to deposit a 30 μm tungsten layer on a copper substrate. This layer will take the main attack - of both plasma and chemically active lithium."
According to Dushik, coatings obtained from the gas phase have low porosity, which prevents interaction of the copper substrate with liquid lithium. They also have high purity, which prevents contamination of the tokamak working space.
"A pilot batch of coatings on model copper substrates has undergone a series of tests at the NRNU MEPhI and the Research Institute of Electrophysical Equipment," noted Dushik. "Tests on lithium wettability and lithium flow in a vacuum, heat dissipation uniformity and thermal cycling have shown that, despite the difference in the thermal expansion coefficients of tungsten and copper, as well as the low thickness, the tungsten coating retains its durability, integrity and protective properties."

Сравнив современные климатические тенденции с климатом планеты 3 млн лет назад, международная группа ученых пришла к выводу, что большая часть приповерхностной вечной мерзлоты может практически полностью исчезнуть уже к 2100 году. Если глобальное потепление не остановится, вечная мерзлота останется только на Восточно-Сибирском нагорье, Канадском Арктическом архипелаге и на севере Гренландии - так же, как это было в теплый период среднего плиоцена.
В исследованиях участвовали ученые из США, России, Великобритании, Германии, Японии, Канады, Нидерландов, Франции и Швеции.

Most of Earth's near-surface permafrost could be gone by 2100, an international team of scientists has concluded after comparing current climate trends to the planet's climate 3 million years ago.
The team found that the amount of near-surface permafrost could drop by 93% compared to the preindustrial period of 1850 to 1900. That's under the most extreme warming scenario in the latest report of the Intergovernmental Panel on Climate Change.
By 2100, Earth's near-surface permafrost, within the upper 10 to 13 feet of the soil layer, may exist only in the eastern Siberian uplands, Canadian High Arctic Archipelago and northernmost Greenland - just like it did in the mid-Pliocene Warm Period.
The research, published Aug. 28 in Proceedings of the National Academy of Sciences, was led by Donglin Guo of the Chinese Academy of Sciences and Nanjing University of Information Science & Technology. Scientists from the United States, Russia, United Kingdom, Germany, Japan, Canada, The Netherlands, France and Sweden collaborated in the research.
"Our study indicates dramatically smaller-than-present near-surface permafrost extent in the geological past, under climate conditions analogous to those expected if global warming continues unabated," the authors write.
Professor emeritus Vladimir Romanovsky of the University of Alaska Fairbanks Geophysical Institute is among the co-authors. Romanovsky is a leading scientist in permafrost research.
"The loss of this much near-surface permafrost over the next 77 years will have widespread implications for human livelihoods and infrastructure, for the global carbon cycle and for surface and subsurface hydrology," Romanovsky said. "This research rings yet another alarm bell for what is happening to Earth's climate."
Simulations of the mid-Pliocene Warm Period climate are similar to the climate projection for the end of this century under the fossil-fueled development pathway in the latest report of the IPCC. That pathway is the bleakest of five presented for future society.
Simulations for the mid-Pliocene Warm Period and projections of permafrost extent in 2100 focus only on near-surface permafrost, which is less resistant to climate warming than deep permafrost.
Ten computer models project Earth will lose approximately 77% of its near-surface permafrost by 2100, relative to 1995-2014, under the IPCC's fossil-fueled development pathway if the surface air temperature increases by 13.5° Fahrenheit.
The paper's authors chose to compare Earth's projected future to the mid-Pliocene Warm Period, which occurred approximately 3 million years ago, because it is the most recent period of sustained global warmth in the planet's geological history.
Scientists have little direct information about Northern Hemisphere permafrost during the mid-Pliocene Warm Period. To overcome that, they analyzed other factors, such as vegetation composition and special soil features, to reconstruct surface air temperature records. From that proxy evidence, they projected permafrost extent of the mid-Pliocene Warm Period.
Using computer modeling, they determined that the global annual mean surface temperature at that time was between 5 and 6° Fahrenheit warmer than the pre-industrial period. It also showed that the temperature was almost 13° higher in Arctic regions.
Absence of permafrost is also inferred by marine fossil sediment records in northwestern Alaska, the paper states.
The authors add that simulated winter and summer temperature and precipitation variables, which arguably have the strongest impact on permafrost stability, have been shown to be similar for the mid-Pliocene and the years 2100 and 2200.
The authors write that the study of mid-Pliocene Warm Period permafrost distribution and associated climate drivers "can improve our understanding of the extent, dynamics and uncertainty of permafrost loss in a warmer future climate."
"Based on our findings, the future of Northern Hemisphere near-surface permafrost appears bleak," the authors write. "Continued climate warming and related near-surface permafrost degradation may cause changes in ambient and environmental conditions that humans have not yet experienced, implying an imperative to further highlight the importance of permafrost degradation."

Уральские ученые усовершенствовали способ Байера, наиболее часто используемый при переработке бокситов, что позволило повысить извлечение оксида алюминия с 80-85% до 95-98%. Кроме того, количество отходов снижается почти в три раза.

The scientists of the Ural Federal University modified the Bayer technology and increased the efficiency of the extraction of aluminum oxide (alumina) from bauxite (the main raw material for the production of aluminum). With the standard processing method, the maximum alumina extraction rate was 80-85 percent. The modified technology will allow up to 95-98 percent of the substance to be extracted from the bauxite. In addition, the new processing method will reduce the amount of red mud (also known as bauxite sludge), a byproduct of the bauxite processing process. This will contribute to sustainable and environmentally friendly production. More information is available in the journal Metals. The work was supported by the Russian Science Foundation (Project No. 22-29-01515).
"For every ton of bauxite, the standard Bayer process produces 0.7 to 1 ton of red mud. This means that for every ton of bauxite we process, almost the same amount of red mud is stored in the sludge fields. Our process allows us to reduce the red mud emission to 300 kg per ton of bauxite. In addition, the alumina recovery rate increases significantly - up to 98 percent, compared to 80-85 percent for conventional processing," explains Andrei Shoppert, Associate Professor at the Department of Non-Ferrous Metallurgy at UrFU.
Red mud is produced during the process of chemical treatment with alkaline solutions of crushed bauxite to extract alumina. The main hazard of red mud is its high alkalinity and the presence of heavy metals and other hazardous substances.
"In the Sverdlovsk region, for example, there are two alumina refineries. During their operation since the middle of the last century, more than 100 million tons of red sludge have accumulated. It can be a source of man-made disasters, as was the case in Hungary in 2010. In addition, if the sludge is too dry, its particles can be carried by the wind and pollute the environment," says Andrei Shoppert.
The Bayer process is the most commonly used method of producing alumina from bauxite. The process begins by crushing the bauxite into small fractions so that it can be more easily processed by hydrometallurgical methods. The crushed bauxite is then placed in steel reactors and mixed with an alkaline solution. After mixing and holding under pressure at 230°C for several hours, the alumina is extracted into the solution, leaving a solid residue called red mud. The resulting solution is sent to precipitate aluminum hydroxide. The aluminum hydroxide is then calcined to produce alumina powder, which can be used to produce aluminum.
To improve Bayer’s technology, scientists applied the technology of electrolytic reduction of iron compounds. This increased the leaching efficiency by removing stubborn minerals containing iron along with aluminum. In addition, the amount of alumina lost along with silicon was reduced by pre-siliconizing the bauxite at 95-120°C.
The scientists will continue to work in this direction. The next experiments will focus on refining the process to ensure that no red sludge is formed by producing metallic iron during electrolysis, a process in which an electric current is used to reduce chemical compounds.
The study also involved scientists from the Vernadsky Institute of Geochemistry and Analytical Chemistry of the Russian Academy of Sciences.

Ученые Балтийского федерального университета имени Иммануила Канта совместно с коллегами из Малайзии обнаружили, что водный экстракт папоротника Nephrolepis biserrate обладает высокой эффективностью против бактерий вибрионов и паразитов, поражающих рыбу в системах аквакультуры.

Scientists from Immanuel Kant Baltic Federal University have found out unique properties of Asian plant, that help to struggle with vermin at fish farms. Extract of fern contains a lot of useful chemical compounds, that combine antibacterial and antiparasitic activity, and can soon become safe alternative to chemicals. The research, supported by grant of Russian Scientific Fund (RNF), is published in magazine Molecules.
Vibriosis is a bacterial disease, that presents a significant threat to fish and shell-fish, bred in aquacultures. In general, it is caused by several kinds of bacteria from Vibrio family. Microbe is able to infect a wide range of fish, including an important industrial one - ocean perch. Apart from vibriosis, aquaculture faces the problem of vermintation. One of the well-known examples is a parasitic leech Zeylanicobdella arugamensis, that lives in tropical regions. Fish, infected by that leech, perish very quickly, and that suffer damage to fish farms. Besides this, as scientists think, this parasite carries in itself bacteria Vibrio, that was mentioned earlier. Thus, parasites, whether microbes or leeches, suffer a significant damage to aquaculture and lead to essential economic losses.
Scientists from Immanuel Kant Baltic Federal University together with colleagues from Malaysia have studied useful features of fern Nephrolepis biserrate and found out that its extract effectively struggles with parasites and microbes, that infect fish in aquacultures. It must be noted that nowadays only chemicals are use to struggle with parasites. They are effective, but harm ecology and human health, whereas substances, extracted by scientists from plants, are less dangerous. Moreover, specialists have found out that fern extract suppresses the growth of bacteria Vibrio in 2.5 times more effectively, killing them within a radius of 19 mm, than methanol and chloroform that are able to suppress activity of vermin only in a radius of 8 mm.
Scientists have analyzed chemical composition of extract of fern and found out several classes of substances that have activity against parasites. Phenol and flavonoids are of the most frequent occurrence. These compounds were discovered also in other plants, and their biological activity is connected with antimicrobic and antiparasitic effect. Among other chemical matters scientists have found various aromatic compounds, such as cinnamylic acid, that successfully struggles with parasites. Nicotinamide should also be mentioned, it is a vitamin from group B, that demonstrates activity against parasite Trypanosoma cruzi that is dangerous as for people and also for animals, because it causes gastrointestinal disease known as Chagas disease.
"The results of research are very promising and witness about potential of aqueous extract of fern against Vibrio and leeches. The analysis has enabled to find out 118 compounds, among which there are a lot of metabolites with antibacterial and antiparasitic activity, for example, cinnamylic acid and nicotinamide. Obtained results enable to suggest that aqueous extract of fern can be used as a natural alternative in struggle against infections in systems of aquaculture. It is obvious that aqueous extract of fern is a promising functional product for fish farming and aquaculture. It is possible to produce on its base feed stuff for growing fish and also products for improving quality of aquatic environment", - tells Olga Babich, director of Immanuel Kant Baltic Federal University, Research and Education Center "Industrial Biotechnologies", leader of the grant of RSF.

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