616 research outputs found
Long-term impact of fecal transplantation in healthy volunteers
Fecal microbiota transplantation (FMT) has been recently approved by FDA for the treatment of refractory recurrent clostridial colitis (rCDI). Success of FTM in treatment of rCDI led to a number of studies investigating the effectiveness of its application in the other gastrointestinal diseases. However, in the majority of studies the effects of FMT were evaluated on the patients with initially altered microbiota. The aim of our study was to estimate effects of FMT on the gut microbiota composition in healthy volunteers and to monitor its long-term outcomes.Peer ReviewedPostprint (published version
Beyond Moore's technologies: operation principles of a superconductor alternative
The predictions of Moore's law are considered by experts to be valid until
2020 giving rise to "post-Moore's" technologies afterwards. Energy efficiency
is one of the major challenges in high-performance computing that should be
answered. Superconductor digital technology is a promising post-Moore's
alternative for the development of supercomputers. In this paper, we consider
operation principles of an energy-efficient superconductor logic and memory
circuits with a short retrospective review of their evolution. We analyze their
shortcomings in respect to computer circuits design. Possible ways of further
research are outlined.Comment: OPEN ACCES
Influence of the spin-dependent quasiparticle distribution on the Josephson current through a ferromagnetic weak link
The Josephson current flowing through weak links containing ferromagnetic
elements is studied theoretically under the condition that the quasiparticle
distribution over energy states in the interlayer is spin-dependent. It is
shown that the interplay between the spin-dependent quasiparticle distribution
and the triplet superconducting correlations induced by the proximity effect
between the superconducting leads and ferromagnetic elements of the interlayer,
leads to the appearence of an additional contribution to the Josephson current.
This additional contribution can be extracted from the full Josephson
current in experiment. The features of the additional supercurrent , which
are of main physical interest are the following: (i) We propose the
experimental setup, where the contributions given by the short-range (SRTC) and
long-range (LRTC) components of triplet superconducting correlations in the
interlayer can be measured separately. It can be realized on the basis of
S/N/F/N/S junction, where the interlayer is composed of two normal metal
regions with a spiral ferromagnet layer sandwiched between them. For the case
of tunnel junctions the measurement of in such a system can provide
direct information about the energy-resolved anomalous Green's function
components describing SRTC and LRTC. (ii) In some cases the exchange
field-suppressed supercurrent can be not only recovered but also enhanced with
respect to its value for non-magnetic junction with the same interface
resistances by the presence of spin-dependent quasiparticle distribution. This
effect is demonstrated for S/N/S junction with magnetic S/N interfaces. In
addition, it is also found that under the considered conditions the dependence
of the Josephson current on temperature can be nontrivial: at first the current
rises upon temperature increasing and only after that starts to decline.Comment: 19 pages, 9 figures, published version, presentation improve
Publication activity and its role in assessment of professional engagement of hei academic staff (Russian practices)
The aim of the research is to analyze and summarize the Russian best practices of using the publication activity as a criterion to assess the professional activity of the academic staff; to identify the role of motivational factors as a method to manage and control the publication activity of the academic staff. Methods. The authors address the methodology of comprehensive research based on the method of document analysis, comparative analysis, and method of secondary use of sociological and psychological data. Results and scientific novelty concludes in presenting Russian and international best practices generalized on using the publication activity to assess the engagement of HEI (Higher Educational Institution) academic staff; the most appropriate formats of using the publication activity as a criterion to assess the research component of the academic staff engagement are defined. Degree of reliability of this criterion is shown – its strengths and shortcomings. The conclusion is drawn on need of the essential changes in management of publication activity affecting both professional and motivational spheres of scientific and pedagogical staff. The most acceptable options of measurement of staff work efficiency of this category are formulated. Practical significance. The research outcomes can be the corpus for designing the assessment method for the professional engagement of the academic staffЦели описанного в статье исследования – проанализировать и обобщить российский опыт использования публикационной активности в качестве критерия оценки профессиональной деятельности научно-педагогических работников; выявить роль мотивационных факторов, влияющих на эту активность. Методы и методология. Авторами в ходе изучения заявленной темы применялась методология комплексного исследования, включающая методы анализа документов, сравнительного анализа, вторичного использования социологических и психологических данных. Результаты и научная новизна. Рассмотрена международная и отечественная практика применения количественных и качественных показателей деятельности научно-педагогических работников вузов. Вскрыты причины, почему публикационная активность становится одним из ключевых параметров оценки достижений конкретного ученого, организации, в которой ведется научная работа, и в целом научного сообщества того или иного государства. Показана степень надежности данного критерия – его достоинства и недостатки. Сделан вывод о необходимости существенных изменений в управлении публикационной активностью, затрагивающих как профессиональную, так и мотивационную сферу научно-педагогических работников. Сформулированы наиболее приемлемые варианты измерения эффективности труда специалистов этой категории. Практическая значимость. Материалы статьи могут служить базой для создания методики оценки профессиональной деятельности научно-педагогических кадро
Гнездование большого баклана (Phalacrocorax carbo) на техногенных сооружениях в Украине
In Ukraine the Great Cormorant (Phalacrocorax carbo Linnaeus, 1758) uses a rather wide range of habitats for nesting: islands, trees and shrubs, reedbeds and a variety of man-made structures. In general, the strategy of nesting on man-made structures is uncommon both in Ukraine and Europe, and Cormorantsdo this only in the absence of other sites suitable for nesting. Special research onCormorant colonies on technogenic constructions was carried out during the field expeditions by the Research Institute of Biodiversity of Terrestrial and Aquatic Ecosystems of Ukraine in 2002–2003 and 2012–2016. Besides this, we used retrospective and current data from the literature and Internet resources. Most of the field work was carried out by making surveys by boat and on foot. As a result, we found 8 Cormorant colonies on technogenic constructions in Ukraine: gas platforms in the Sea of Azov (near the village Strilkove, Henichesk district of Kherson region); sunken ships – targets for bombing training near the Arabat Spit (these are also known as «ship islands»); electricity pylons of the high-voltage Enerhodar Dnipro Power Line where it crosses the Kakhovka Reservoir; the dock in Yahorlyk Bayk, used in the past as a target for bombing training bombing; artificial island-platforms on Lake Chernine (Kinburn Peninsula); an artificial island on the Sasyk Lagoon (Odessa region); artificial islands, made as navigation markers on the Kremenchuk and Kiev reservoirs. The study found that in most cases the accompanying species was the CaspianGull (Larus cachinnans Pallas, 1811), which actively destroys the Cormorants’ nests and eats their eggs and chicks. The number of nests in the colonies varied greatly (5–30 nests on the navigation marker islands and ca. 2 000–2 300 on the «ship-islands» and gas platforms). This is due, primarily, to the area of the breeding territory. The research found that fierce territorial competition was observed in most of the colonies both with Caspian Gulls and between Cormorants. In addition, we observed anthropogenic interference in the colonies by fishermen and workers conducting routine maintenance work (as happened in the case of electricity pylons and gas platforms). The benefit of this study is that it is the first research in Ukraine conducted at national level onthis type of nesting by Cormorants. Moreover, the study examines the history of emergence of these nesting territories and population dynamics of the Great Cormorant from the time of initial settlement of the breeding sites till the present.Гнездование большого баклана (Phalacrocorax carbo Linnaeus, 1758)на техногенных сооружениях является одним из проявлений его стратегии гнездостроительства, помимо наземной и древесной. В Украине установлены следующие техногенные объекты, служащие гнездовыми территориями для баклана: газовые вышки в Азовском море, затопленные корабли и док – мишени для учебного бомбометания, опоры ЛЭП и рукотворные острова на Киевском и Кременчугском водохранилищах, озерах Сасык и Чернино. В настоящее время существуют шесть из них. В большинстве случаев сопутствующим видом является чайка-хохотунья (Larus cachinnans Pallas, 1811), активно разоряющая гнезда баклана и поедающая яйца и птенцов. Оценена динамика численности баклана с момента заселения объектов и по настоящее время. Антропогенное вмешательство в колониях происходит не только в тех случаях, когда это предписано регламентными эксплуатационными работами (как на опорах ЛЭП и газовых вышках), но и со стороны посещающих гнездовья рыбаков. Ввиду отсутствия гнездопригодных территорий поблизости в колониях наблюдается ощутимая территориальная конкуренция как с чайкой-хохотуньей, так и между бакланами.Гнездование большого баклана (Phalacrocorax carbo Linnaeus, 1758)на техногенных сооружениях является одним из проявлений его стратегии гнездостроительства, помимо наземной и древесной. В Украине установлены следующие техногенные объекты, служащие гнездовыми территориями для баклана: газовые вышки в Азовском море, затопленные корабли и док – мишени для учебного бомбометания, опоры ЛЭП и рукотворные острова на Киевском и Кременчугском водохранилищах, озерах Сасык и Чернино. В настоящее время существуют шесть из них. В большинстве случаев сопутствующим видом является чайка-хохотунья (Larus cachinnans Pallas, 1811), активно разоряющая гнезда баклана и поедающая яйца и птенцов. Оценена динамика численности баклана с момента заселения объектов и по настоящее время. Антропогенное вмешательство в колониях происходит не только в тех случаях, когда это предписано регламентными эксплуатационными работами (как на опорах ЛЭП и газовых вышках), но и со стороны посещающих гнездовья рыбаков. Ввиду отсутствия гнездопригодных территорий поблизости в колониях наблюдается ощутимая территориальная конкуренция как с чайкой-хохотуньей, так и между бакланами
Geological-morphological description of the Ishtar Terra (photomap of the Venusian surface sheet B-5)
The main part of the Ishtar Terra east of the Maxwell Montes is covered with systems of areal dislocations of several directions, which are called Parquet. According to the structural patterns these may be divided into: (1) the central stable block; (2) the lesser peripheral blocks separated from the central one by gaps and grabens; (3) the zones of mobilized parquet, whose substance flowed downward at an incline in the directions away from the central block in the form of plastic flows; and (4) the partially parqueted lava sheets. The Maxwell Montes were formed as a result of the collision between the central parquet block and the Lakshmi Planum
Re-entrant superconductivity in Nb/Cu(1-x)Ni(x) bilayers
We report on the first observation of a pronounced re-entrant
superconductivity phenomenon in superconductor/ferromagnetic layered systems.
The results were obtained using a superconductor/ferromagnetic-alloy bilayer of
Nb/Cu(1-x)Ni(x). The superconducting transition temperature T_{c} drops sharply
with increasing thickness d_{CuNi} of the ferromagnetic layer, until complete
suppression of superconductivity is observed at d_{CuNi}= 4 nm. Increasing the
Cu(1-x)Ni(x) layer thickness further, superconductivity reappears at
d_{CuNi}=13 nm. Our experiments give evidence for the pairing function
oscillations associated with a realization of the quasi-one dimensional
Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) like state in the ferromagnetic layer.Comment: 3 pages, 3 figures, REVTEX4/twocolum
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