56 research outputs found
An Effect of Co–W Barrier Sublayer on the Functional Characteristics of Au–Ru Contact Coatings
Funding Information: Funding: This work was supported by the Ministry of Education and Science of the Russian Federation in the frame of the state assignment FSSN-2020-0003. Publisher Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland.The performance characteristics (microhardness, porosity, roughness, and transient resistance) of Au–Ru coatings with and without the Co–W alloy barrier sublayer electrodeposited on the surface of contact blades of commercially produced reed switches were investigated. It was found that the barrier sublayer reduces the average roughness of the coatings without significant change in their porosity. The Au–Ru coatings without sublayer exhibited a greater variation in the transient resistance during an increase in the pressing force. The service time of reed switches with the barrier sublayer increased in both testing modes: in low-power (50 mV, 5 µA, 50 Hz) by more than 4 × 106 switching cycles, and in mean-power (12 V, 0.25 A, 50 Hz) by more than 1.8 × 106 switching cycles.publishersversionpublishe
Spatial distribution of Oreoleuciscus potanini in evenings in the Bayan Nur lake, Мohgolia
Вивчено розподіл алтайського османа в одному з озер Монголії улітку. Показники ехолота GPSMAP 178 фіксували цифровим фотоапаратом. Аналіз горизонтального розподілу риб показав, що максимальна концентрація та мінімальна варіабельність густоти ехомішеней відмічена на ділянках із глибинами 6–15 м. Аналіз вертикального розподілу розрідженого скупчення риб у пелагіалі виявив дві зони концентрації риб (2–4 м і від 10 м та глибше), між якими риби відмічаються поодиноко. Щільні скупчення риб, навпаки, локалізовані в основному у середніх шарах. Изучено распределение алтайского османа в одном из озер Монголии в летнее время. Показания эхолота GPSMAP 178 фиксировали цифровым фотоаппаратом. Анализ горизонтального распределения рыб показал, что максимальная концентрация и минимальная вариабельность плотности эхомишеней отмечались на участках глубиной 6–15 м. Анализ вертикального распределения разреженного скопления рыб в пелагиали выявил две зоны концентрации рыб (2–4 м и от 10 м и глубже), между которыми рыбы отмечаются одиночно. Плотные скопления рыб, напротив, локализованы в основном в средних слоях.Distribution of the altay osman in one of the lakes of Mongolia was studied in summer. Indications of the sonar GPSMAP 178 were fixed withdigital camera. Analysis of fish horizontal distribution had shown that the maximal concentrations and minimal variability of fish density were registered in the areas with depths of 6–15 m. Analysis of vertical distribution of pelagic rarefied fish aggregationshas revealed two fish concentration zones (2–4 m and from 10 m to deeper). Between those zones the fish scores were sparse. On the contrary, dense aggregationsof fishes locate at the middle water strata in the core.
ВЕТЕРИНАРНЫЕ ПРОБЛЕМЫ ОЛЕНЕВОДСТВА В РЕГИОНЕ ЕВРОПЕЙСКОГО СЕВЕРА РОССИИ
Objective of research. As deer are kept year-round on pasture (in summer in tundra in the northern coast of the Russian arctic; in winter – in forest-tundra and northern taiga), biogeocenosis and natural focality of most parasitic and infectious diseases were formed over the years. That should be considered when developing methods for combating them, and to determine the optimal timing of mass treatment and prevention measures.Materials and methods. The question naturally arises, which living and nonliving components ensure pathogen survivability, contribute to the emergence and spread of infectious and invasive diseases. Each disease is characterized by specific factors requiring careful examination and generalization based on the study of clinical records and epizootic diseases in reindeer of the European North of Russia.Results and discussion. Dominant diseases of reindeer in the European region ofNorthern Russia, requiring greater attention of veterinary experts and against which it is necessary to conduct a regular complex of veterinary, prevention and treatment measures are: anthrax, edemagenosis, cephenomiosis, necrobacillosis, echinococcosis, cysticercosis, rabies, leptospirosis, number of helminthoses (strongylatosis, monieziasis, echinococcosis, cysticercosis, etc.). This is a brucellosis-free region, and for many tens years no outbreaks of FMD were reported. The vast majority of the tundra is located in the permafrost zone; the area is dotted with numerous canals, lakes, rivers, streams, marshes, between which in summer on shallow layered soil, grow bushes of willow, dwarf birch, berries, grass and lichen, the main food of deer. The fauna of the tundra is rich and diverse. Here live wolves, foxes, bears, rodents (lemmings, mice), rabbits, birds (geese, ducks, partridges, gulls) and other animals. In summer, "clouds" of midges (mosquitoes, midges, horseflies, flies) are flying in the air. In the region, there are still places virtually untouched by man. However, in recent years, intensive industrial development of the region began to carry out exploration and extraction of oil, gas and other minerals. Oil and gas pipelines, roads, power lines are built which certainly cannot affect negatively the extremely vulnerable nature of the North. For example, reindeer moss trampled or torn down by moving offroaders can be restored only after 7-10 years. Summer season in the North is a very short period, there are usually few warm and sunny days. These negative factors lead to reduced pastures and do not contribute to the growth of the deer population, their health status and fatness.Цель исследования. Поскольку олени содержатся на круглогодовом выпасе (летом в тундре прибрежных районов Северных морей, зимой в лесотундре и северо-таёжной зоне), существует сложившийся годами биогеоценоз и природная очаговость большинства паразитарных и инфекционных заболеваний, что необходимо учитывать при разработке методов борьбы с ними, и определить оптимальные сроки проведения массовых лечебно-профилактических мероприятий. Материалы и методы. Естественно возникает вопрос, какие живые и неживые компоненты природы обеспечивают сохранность возбудителя болезни, способствуют возникновению и распространению инфекционных и инвазионных заболеваний. Для каждой болезни факторы индивидуальны, требуют внимательного изучения и обобщения на основе изучения истории болезней и эпизоотий в оленеводстве Европейского Севера России, что и представлено в настоящей работе. Результаты и обсуждение. Доминирующими болезнями оленей в регионе Европейского Севера России, требующими повышенного внимания ветеринарных специалистов и против которых необходимо регулярно проводить комплекс ветеринарно-профилактических и лечебных мероприятий являются: сибирская язва, эдемагеноз, цефеномиоз, некробактериоз, эхинококкоз, цистицеркоз, бешенство и дикование, лептоспироз, ряд гельминтозов (стронгилятозы, мониезиоз, эхинококкоз, цистицеркоз и др.). Регион благополучен по бруцеллёзу и уже десятки лет не отмечалось вспышек ящура. Подавляющая часть тундры находится в зоне вечной мерзлоты; местность испещрена многочисленными протоками, озёрами, реками, ручьями, болотами, между которыми, на оттаивающем в летний период неглубоком слое почвы, растут кустарники ивняка, карликовых берёз, ягодника, трава и ягель, основной корм оленей. Животный мир тундры богат и разнообразен. Здесь уживаются волки, песцы, медведи, многочисленные грызуны (лемминги, мыши), зайцы, птицы (гуси, утки, куропатки, чайки) и пр. живность. В летний период в воздухе летает буквально «тучами» гнус (комары, мошки, слепни, мухи). В регионе имеются ещё места, практически, не тронутые человеком, однако, в последние годы началось интенсивное промышленное освоение края в целях поиска и добычи нефти, газа, других полезных ископаемых. Прокладываются и строятся нефте- и газопроводы, дороги, ЛЭП и пр., что, безусловно не может не отразиться негативно на чрезвычайно ранимой природе Севера. Например, вытоптанный или порушенный при движении вездеходов ягель может восстановиться лишь через 7-10 лет. Летний период на Севере кратковременный и, как правило, с малым числом тёплых, солнечных дней. Все эти негативные факторы ведут к сокращению площадей пастбищ и не способствуют росту поголовья оленей, состоянию их здоровья и упитанности
Potential limitations of biogenic silica as an indicator of abrupt climate change in Lake Baikal, Russia
VETERINARY PROBLEMS OF REINDEER HUSBANDRY IN THE EUROPEAN NORTH OF RUSSIA
Objective of research. As deer are kept year-round on pasture (in summer in tundra in the northern coast of the Russian arctic; in winter – in forest-tundra and northern taiga), biogeocenosis and natural focality of most parasitic and infectious diseases were formed over the years. That should be considered when developing methods for combating them, and to determine the optimal timing of mass treatment and prevention measures.Materials and methods. The question naturally arises, which living and nonliving components ensure pathogen survivability, contribute to the emergence and spread of infectious and invasive diseases. Each disease is characterized by specific factors requiring careful examination and generalization based on the study of clinical records and epizootic diseases in reindeer of the European North of Russia.Results and discussion. Dominant diseases of reindeer in the European region ofNorthern Russia, requiring greater attention of veterinary experts and against which it is necessary to conduct a regular complex of veterinary, prevention and treatment measures are: anthrax, edemagenosis, cephenomiosis, necrobacillosis, echinococcosis, cysticercosis, rabies, leptospirosis, number of helminthoses (strongylatosis, monieziasis, echinococcosis, cysticercosis, etc.). This is a brucellosis-free region, and for many tens years no outbreaks of FMD were reported. The vast majority of the tundra is located in the permafrost zone; the area is dotted with numerous canals, lakes, rivers, streams, marshes, between which in summer on shallow layered soil, grow bushes of willow, dwarf birch, berries, grass and lichen, the main food of deer. The fauna of the tundra is rich and diverse. Here live wolves, foxes, bears, rodents (lemmings, mice), rabbits, birds (geese, ducks, partridges, gulls) and other animals. In summer, "clouds" of midges (mosquitoes, midges, horseflies, flies) are flying in the air. In the region, there are still places virtually untouched by man. However, in recent years, intensive industrial development of the region began to carry out exploration and extraction of oil, gas and other minerals. Oil and gas pipelines, roads, power lines are built which certainly cannot affect negatively the extremely vulnerable nature of the North. For example, reindeer moss trampled or torn down by moving offroaders can be restored only after 7-10 years. Summer season in the North is a very short period, there are usually few warm and sunny days. These negative factors lead to reduced pastures and do not contribute to the growth of the deer population, their health status and fatness
Electrochemical Deposition of Ni–W Crack-Free Coatings
The main features of electrochemical deposition of coatings based on Ni–W binary alloy in the pulse current mode using pyrophosphate electrolytes were studied. Two electrolytes with a pH of 8.7 and 9.5 were used. The deposition was carried out with the current density varying in the range of 0.01–0.1 A·cm−2, and the duty cycle (the relative pulse duration) was changed within the range 20–100%. The surface morphology and elemental and phase composition of the coatings were studied by scanning electron microscopy, energy-dispersive X-ray microanalysis and X-ray diffractometry. The experimental conditions allowing us to achieve the maximum Faradaic efficiency and W content in the coatings were determined. It was found that the pulse current mode enabled the fabrication of crack-free coatings with a thickness greater than 6 μm
Phylogeography of Daphnia magna Straus (Crustacea: Cladocera) in Northern Eurasia: Evidence for a deep longitudinal split between mitochondrial lineages.
Species with a large geographic distributions present a challenge for phylogeographic studies due to logistic difficulties of obtaining adequate sampling. For instance, in most species with a Holarctic distribution, the majority of studies has concentrated on the European or North American part of the distribution, with the Eastern Palearctic region being notably understudied. Here, we study the phylogeography of the freshwater cladoceran Daphnia magna Straus, 1820 (Crustacea: Cladocera), based on partial mitochondrial COI sequences and using specimens from populations spread longitudinally from westernmost Europe to easternmost Asia, with many samples from previously strongly understudied regions in Siberia and Eastern Asia. The results confirm the previously suspected deep split between Eastern and Western mitochondrial haplotype super-clades. We find a narrow contact zone between these two super-clades in the eastern part of Western Siberia, with proven co-occurrence in a single lake in the Novosibirsk region. However, at present there is no evidence suggesting that the two mitochondrial super-clades represent cryptic species. Rather, they may be explained by secondary contact after expansion from different refugia. Interestingly, Central Siberia has previously been found to be an important contact zone also in other cladoceran species, and may thus be a crucial area for understanding the Eurasian phylogeography of freshwater invertebrates. Together, our study provides an unprecedented complete, while still not global, picture of the phylogeography of this important model species
New Sets of Primers for DNA Identification of Non-Indigenous Fish Species in the Volga-Kama Basin (European Russia)
Adequate species’ identification is critical for the detection and monitoring of biological invasions. In this study, we proposed and assessed the efficiency of newly created primer sets for the genetic identification of non-indigenous species (NIS) of fishes in the Volga basin based on: (a) a “long” fragment of cytochrome c oxidase subunit one of the mitochondrial gene (COI) (0.7 kb), used in “classical” DNA barcoding; (b) a short 3’-fragment (0.3 kb) of COI, suitable for use in high-throughput sequencing systems (i.e., for dietary analysis); (c) fragment of 16S mitochondrial rRNA, including those designed to fill the library of reference sequences for work on the metabarcoding of communities and eDNA studies; (d) a fragment of 18S nuclear rRNA, including two hypervariable regions V1-V2, valuable for animal phylogeny. All four sets of primers demonstrated a high amplification efficiency and high specificity for freshwater fish. Also, we proposed the protocols for the cost-effective isolation of total DNA and purification of the PCR product without the use of commercial kits. We propose an algorithm to carry out extremely cheap studies on the assessment of biological diversity without expensive equipment. We also present original data on the genetic polymorphism of all mass NIS fish species in the Volga-Kama region. The high efficiency of DNA identification based on our primers is shown relative to the traditional monitoring of biological invasions
Phylogeography of the <i>Chydorus sphaericus</i> Group (Cladocera: Chydoridae) in the Northern Palearctic
<div><p>The biodiversity and the biogeography are still poorly understood for freshwater invertebrates. The crustacean <i>Chydorus sphaericus-brevilabris</i> complex (Cladocera: Chydoridae) is composed of species that are important components of Holarctic freshwater food webs. Recent morphological and genetic study of the complex has indicated a substantial species diversity in the northern hemisphere. However, we know little of the geographic boundaries of these novel lineages. Moreover, a large section of the Palearctic remains unexamined at the genetic level. Here we attempt to address the biodiversity knowledge gap for the <i>Chydorus sphaericus</i> group in the central Palearctic and assess its diversity and biogeographic boundaries. We sequenced nuclear (<i>ITS-2</i>) and mitochondrial (<i>COI</i>) gene regions of <i>Chydorus</i> specimens across the Palearctic and compared them with already available Holarctic sequences. We detected six main clades in the <i>C</i>. <i>sphaericus</i> group in the Palearctic, of which two of the groups are novel. Three of the more divergent clades are geographically widespread. The central portion of Eurasia (the Yenisey River basin) appears to be a narrow zone of secondary contact for phylogroups that expanded from European and Beringian refugia. As such, the previously unsampled central Palearctic represents an important region for understanding the evolutionary consequences of Pleistocene climatic oscillations on the <i>Chydorus sphaericus</i> group.</p></div
Complete subtree (collapsed in Fig 2) for the clades A1, A2 and A3 of the <i>Chydorus sphaericus</i> group showing support of the terminal clades.
<p>Geometric symbols for Eurasian taxa correspond to those in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0168711#pone.0168711.g001" target="_blank">Fig 1</a>.</p
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