Topological energy barrier for skyrmion lattice formation in MnSi

We report the direct measurement of the topological skyrmion energy barrier through a hysteresis of the skyrmion lattice in the chiral magnet MnSi. Measurements were made using small-angle neutron scattering with a custom-built resistive coil to allow for high-precision minor hysteresis loops. The experimental data was analyzed using an adapted Preisach model to quantify the energy barrier for skyrmion formation and corroborated by the minimum-energy path analysis based on atomistic spin simulations. We reveal that the skyrmion lattice in MnSi forms from the conical phase progressively in small domains, each of which consisting of hundreds of skyrmions, and with an activation barrier of several eV.Comment: Final accepted versio

Coherent spin dynamics of electrons and holes in semiconductor quantum wells and quantum dots under periodical optical excitation: resonant spin amplification versus spin mode-locking

The coherent spin dynamics of resident carriers, electrons and holes, in semiconductor quantum structures is studied by periodical optical excitation using short laser pulses and in an external magnetic field. The generation and dephasing of spin polarization in an ensemble of carrier spins, for which the relaxation time of individual spins exceeds the repetition period of the laser pulses, are analyzed theoretically. Spin polarization accumulation is manifested either as resonant spin amplification or as mode-locking of carrier spin coherences. It is shown that both regimes have the same origin, while their appearance is determined by the optical pump power and the spread of spin precession frequencies in the ensemble

Системное применение иммунологической схемы при диагностике Alternaria sp. и Fusarium sp.

About 6400 genera, including more than 64000 species, belong to ascomycotes. A significant part of ascomycetes are saprotrophs, the leading place belongs to the fungi pp. Alternaria sp. and Fusarium sр. Alternaria species are a very aggressive pathogenic genus that causes diseases in a large number of economically important crops. 300 species of the genus Alternaria have been identified worldwide, including A. dauci, A. radicinia, A. alternata, A. tenuissima, A. brassicicola and A. solani. Crop losses from the genus Alternaria can reach from 40 to 90%. Leaves, petioles and stems are affected. The genus Fusarium includes a number of species that are the causes of various diseases on most agriculturally significant crops. The most common are: F. oxysporum, causing wilting diseases and affecting the vascular system of plants. F. avenaceum is a widespread species, and F. poae belongs to the section Sporotrichiella Wollenw. Fusarium is a common and dangerous fungal disease. Plants are affected at any age. The fungus is located in the soil and penetrates into the plant through the soil and wounds. In young plants, the disease manifests itself in the form of rotting of the roots and root neck. Based on the above pathogenesis, the purpose of our research was to monitor, identify pathogenic fungi pp. Fusarium sр. and Alternaria sрp and develop a scheme with the gradual inclusion of phytopathological methods in the breeding process. Thus, using phytopathological methods of isolating pathogens of alternariasis and fusariasis from different organs of plants and soil, a collection of the most aggressive pathogens pp. Fusarium and Alternaria has been created. Comparative analyses of the informativeness of various methods of immunological assessment of resistance depending on the type of pathogen allowed us to develop and test a scheme for the sequential inclusion in the selection process of various methods that are applicable at different stages of plant development in order to increase the effectiveness of selection for group resistance to pathogens pp. Fusarium and Alternaria. The applied selection and immunological system of methods made it possible to create new tolerant hybrids, as well as valuable starting material with complex resistance to A. radicina, A.dauci and F.oxysporum was obtained from various lines and variety populations.К аскомикотам относят примерно 6400 родов, включающих более 64000 видов. Значительная часть аскомицетов – сапротрофы, лидирующее место принадлежит грибам родов Alternaria sp. и Fusarium sp. Alternaria – очень агрессивный патогенный род, который вызывает болезни у большого количества экономически важных культур. Во всем мире были идентифицированы 300 видов рода Alternaria, включая A. dauci, А. radicinia, A. alternata, A. tenuissima, A. brassicicola и A. solani. Потери урожая от рода Alternaria могут достигать от 40 до 90%. У растений поражаются листья, черешки и стебли. Род Fusarium включает в себя ряд видов, являющихся причинами различных заболеваний на большинстве сельскохозяйственнозначимых культур. Наиболее распространенными являются: F. oxysporum, вызывающий болезни увядания и поражающий сосудистую систему растений; F. avenaceum – широко распространенный вид и F. рoae, относящийся к секции Sporotrichiella Wollenw. Фузариоз – распространенная и опасная грибковая болезнь. Растения поражаются в любом возрасте. Гриб находится в почве и проникает в растение через корни и ранки. У молодых растений заболевание проявляется в виде загнивания корней и корневой шейки. Целью наших исследований был мониторинг, идентификация патогенных грибов родов Fusarium sp. и Alternaria sp. и разработка схемы поэтапного включения фитопатологических методов в селекционный процесс. С использованием фитопатологических методоввыделения возбудителей альтернариоза и фузариоза из разных органов растений и почвы создана коллекция наиболее агрессивных патогенов родов Fusarium и Alternaria. Проведенные сравнительные анализы информативности различных методов иммунологической оценки устойчивости в зависимости от рода возбудителя позволили разработать и апробировать схему последовательного включения в селекционный процесс различных методов, которые применимы на разных стадиях развития растений с целью повышения эффективности отбора на групповую устойчивость к Fusarium и Alternaria. Применяемая селекционно-иммунологическая система позволила создать новые толерантные гибриды, а кроме того, из различных линий, сортопопуляций был получен ценный исходный материал, обладающий комплексной устойчивостью к A. radicina, A. dauci и F. oxysporum

ХАРАКТЕРИСТИКА ИЗОЛЯТОВ рр. ALTERNARIA И FUSARIUM, ВЫДЕЛЕННЫХ С МОРКОВИ СТОЛОВОЙ ИЗ РАЗНЫХ ЭКОЛОГО-ГЕОГРАФИЧЕСКИХ ЗОН

Selection of infected material for research was carried out in experimental carrot plots at GNU VNIIO (Moscow region), Voronezh OOS (Voronezh oblast), Baraccudas OOS (Rostovregion) and Israel. The first year plants of carrot, the roots, were used for the study. There are many scientific papers cited where many different methods of artificial infection of plants with fungal disease pathogens were given to control the stability of carrot genotypes in various phases of plant development. One of the ways to lead the purposed breeding program for resistance is the extraction of pathogens isolates and the method of fast assessment on the basis of determining the aggressiveness of new strains and their use in breeding work. This article presents a method of inoculation of cut-discs of root. A great advantage of the method is in its efficiency and the current results can be obtained within 2 weeks from the moment of infection. As a result, the work on the isolation of fungi from carrot plants, the pure culture collection of strains: Alternaria radicina and Fusarium avenaceum was obtained. The characteristics and morphology description of colonies of isolates of RR. Alternaria and Fusarium found in carrot plants taken from different ecological and geographical zones were given. The most aggressive isolates of the following ecological and geographical zones as Alternaria at Moscow and Rostov regions, Fusarium at Voronezh and Moscow regions were revealed. These isolates will be used as standards of aggressiveness for the test of newly isolated strains regarded as inoculum to conduct immunological experimentsin carrot breeding for resistance to Fusarium and Alternaria.Отбор пораженного материала для исследований проводили на опытных посевах моркови столовой ФГБНУ ВНИИО (Московская обл.), Воронежской ООС (Воронежская обл.), Бирючекутской ООС (Ростовская обл.), Израиля. В качестве объектов исследования использованы растения первого года жизни (корнеплоды). Из литературных источников известно множество различных методов и способов искусственного заражения растений возбудителями грибных заболеваний, которые позволяют контролировать устойчивость генотипов моркови в различные фазы развития растения. Одним из путей, обеспечивающих целенаправленное ведение селекции на устойчивость, является выделение изолятов возбудителей болезней, метод ускоренной оценки на основе определения агрессивности новых штаммов и применение их в селекционной работе. В данной статье представлен метод инокуляции дисков-вырезок корнеплодов. Большое преимущество тестируемого метода – его оперативность, результаты можно получить уже через 2 недели от момента заражения. В результате проведенной работы по выделению грибов срастений моркови столовой в чистую культуру создана коллекция штаммов: Alternaria radicina и Fusarium avenaceum. Дана характеристика и морфология колоний  изолятов рр. Alternaria и Fusarium, выделенных из моркови столовой из разных эколого-географических зон. Выявлены наиболее агрессивные изоляты из следующих эколого-географических зон: Alternaria – Московская и Ростовская области, Fusarium – Воронежская и Московская области. Данные изоляты будут использоваться в качестве стандартов агрессивности при испытании вновь выделенных штаммов и в качестве инокулюма при проведении иммунологических экспериментов в селекции моркови столовой на устойчивость к фузариозу и альтернариозу

Konus-Wind and Helicon-Coronas-F Observations of Solar Flares

Results of solar flare observations obtained in the Konus-Wind experiment from November, 1994 to December, 2013 and in the Helicon Coronas-F experiment during its operation from 2001 to 2005, are presented. For the periods indicated Konus-Wind detected in the trigger mode 834 solar flares, and Helicon-Coronas-F detected more than 300 solar flares. A description of the instruments and data processing techniques are given. As an example, the analysis of the spectral evolution of the flares SOL2012-11-08T02:19 (M 1.7) and SOL2002-03-10T01:34 (C5.1) is made with the Konus-Wind data and the flare SOL2003-10-26T06:11 (X1.2) is analyzed in the 2.223 MeV deuterium line with the Helicon-Coronas-F data.Comment: Published version. A list of the Konus-Wind solar flare triggers and figures of their time profiles are available at http://www.ioffe.ru/LEA/Solar

Psychological and pedagogical support for the social workers professional development

The effectiveness of psychological andpedagogical support is determined by the following factors: self-determination and voluntary participation; activating education results; taking into account and developing social workers’ educational needs; the use of the dichotomic and humanistic approaches; social workers’ selfdetermination; interactive mode of cooperation, democratic style of communicatio

Randomized Reference Classifier with Gaussian Distribution and Soft Confusion Matrix Applied to the Improving Weak Classifiers

In this paper, an issue of building the RRC model using probability distributions other than beta distribution is addressed. More precisely, in this paper, we propose to build the RRR model using the truncated normal distribution. Heuristic procedures for expected value and the variance of the truncated-normal distribution are also proposed. The proposed approach is tested using SCM-based model for testing the consequences of applying the truncated normal distribution in the RRC model. The experimental evaluation is performed using four different base classifiers and seven quality measures. The results showed that the proposed approach is comparable to the RRC model built using beta distribution. What is more, for some base classifiers, the truncated-normal-based SCM algorithm turned out to be better at discovering objects coming from minority classes.Comment: arXiv admin note: text overlap with arXiv:1901.0882

Electron microscopy analysis of ATP-independent nucleosome unfolding by FACT

FACT is a histone chaperone that participates in nucleosome removal and reassembly during transcription and replication. We used electron microscopy to study FACT, FACT:Nhp6 and FACT:Nhp6:nucleosome complexes, and found that all complexes adopt broad ranges of configurations, indicating high flexibility. We found unexpectedly that the DNA binding protein Nhp6 also binds to the C-terminal tails of FACT subunits, inducing more open geometries of FACT even in the absence of nucleosomes. Nhp6 therefore supports nucleosome unfolding by altering both the structure of FACT and the properties of nucleosomes. Complexes formed with FACT, Nhp6, and nucleosomes also produced a broad range of structures, revealing a large number of potential intermediates along a proposed unfolding pathway. The data suggest that Nhp6 has multiple roles before and during nucleosome unfolding by FACT, and that the process proceeds through a series of energetically similar intermediate structures, ultimately leading to an extensively unfolded form

Ageing of kukersite thermobitumen

Ageing of the mix of thermobitumen and oil (TBO) formed at low-temper