Possibility of local pair existence in optimally doped SmFeAsO(1-x) in pseudogap regime

We report the analysis of pseudogap Delta* derived from resistivity experiments in FeAs-based superconductor SmFeAsO(0.85), having a critical temperature T_c = 55 K. Rather specific dependence Delta*(T) with two representative temperatures followed by a minimum at about 120 K was observed. Below T_s = 147 K, corresponding to the structural transition in SmFeAsO, Delta*(T) decreases linearly down to the temperature T_AFM = 133 K. This last peculiarity can likely be attributed to the antiferromagnetic (AFM) ordering of Fe spins. It is believed that the found behavior can be explained in terms of Machida, Nokura, and Matsubara (MNM) theory developed for the AFM superconductors.Comment: 5 pages, 2 figure

Grassmannians Gr(N-1,N+1), closed differential N-1 forms and N-dimensional integrable systems

Integrable flows on the Grassmannians Gr(N-1,N+1) are defined by the requirement of closedness of the differential N-1 forms $\Omega_{N-1}$ of rank N-1 naturally associated with Gr(N-1,N+1). Gauge-invariant parts of these flows, given by the systems of the N-1 quasi-linear differential equations, describe coisotropic deformations of (N-1)-dimensional linear subspaces. For the class of solutions which are Laurent polynomials in one variable these systems coincide with N-dimensional integrable systems such as Liouville equation (N=2), dispersionless Kadomtsev-Petviashvili equation (N=3), dispersionless Toda equation (N=3), Plebanski second heavenly equation (N=4) and others. Gauge invariant part of the forms $\Omega_{N-1}$ provides us with the compact form of the corresponding hierarchies. Dual quasi-linear systems associated with the projectively dual Grassmannians Gr(2,N+1) are defined via the requirement of the closedness of the dual forms $\Omega_{N-1}^{\star}$. It is shown that at N=3 the self-dual quasi-linear system, which is associated with the harmonic (closed and co-closed) form $\Omega_{2}$, coincides with the Maxwell equations for orthogonal electric and magnetic fields.Comment: 26 pages, references adde

Laplace transformations of hydrodynamic type systems in Riemann invariants: periodic sequences

The conserved densities of hydrodynamic type system in Riemann invariants satisfy a system of linear second order partial differential equations. For linear systems of this type Darboux introduced Laplace transformations, generalising the classical transformations in the scalar case. It is demonstrated that Laplace transformations can be pulled back to the transformations of the corresponding hydrodynamic type systems. We discuss periodic Laplace sequences of with the emphasize on the simplest nontrivial case of period 2. For 3-component systems in Riemann invariants a complete discription of closed quadruples is proposed. They turn to be related to a special quadratic reduction of the (2+1)-dimensional 3-wave system which can be reduced to a triple of pairwize commuting Monge-Ampere equations. In terms of the Lame and rotation coefficients Laplace transformations have a natural interpretation as the symmetries of the Dirac operator, associated with the (2+1)-dimensional n-wave system. The 2-component Laplace transformations can be interpreted also as the symmetries of the (2+1)-dimensional integrable equations of Davey-Stewartson type. Laplace transformations of hydrodynamic type systems originate from a canonical geometric correspondence between systems of conservation laws and line congruences in projective space.Comment: 22 pages, Late

Algebraic varieties in Birkhoff strata of the Grassmannian Gr(2)\mathrm{^{(2)}}: Harrison cohomology and integrable systems

Local properties of families of algebraic subsets $W_g$ in Birkhoff strata $\Sigma_{2g}$ of Gr$^{(2)}$ containing hyperelliptic curves of genus $g$ are studied. It is shown that the tangent spaces $T_g$ for $W_g$ are isomorphic to linear spaces of 2-coboundaries. Particular subsets in $W_g$ are described by the intergrable dispersionless coupled KdV systems of hydrodynamical type defining a special class of 2-cocycles and 2-coboundaries in $T_g$. It is demonstrated that the blows-ups of such 2-cocycles and 2-coboundaries and gradient catastrophes for associated integrable systems are interrelated.Comment: 28 pages, no figures. Generally improved version, in particular the Discussion section. Added references. Corrected typo

EFFECT OF THE PROPHAGE CTXΦ DELETION UPON PHENOTYPIC PROPERTIES IN STRAINS OF VIBRIO CHOLERAE BIOVAR EL TOR, ASSOCIATED WITH VIRULENCE AND PERSISTENCE

Objective of the study is to evaluate the influence of CTXφ prophage deletion, which carries ctxAB genes, on phenotypical properties associated with pathogenicity or biofilm formation in non-toxigenic mutants. Materials and methods. Utilized have been the clinical strains of Vibrio cholerae biovar El Tor and their spontaneous non-toxigenic mutants that lost CTXφ prophage. Applied have been microbiological and biochemical methods, inoculation of model animals with cells of the strains under study. Results and conclusions. The results of comparative analysis of phenotypic properties in isogenic toxigenic and non-toxigenic strains of Vibrio cholerae biovar El Tor, which lost CTXφ prophage encoding the cholera toxin, are represented. It is established that the deletion of CTXφ prophage leads to the simultaneous change of several phenotypic properties associated with virulence (colonizing ability, production of soluble hemagglutinin/protease and heat labile hemolysin/cytolysin) and biofilm formation (motility, exopolysaccharide biosynthesis) in spontaneous non-toxigenic mutants. It is suggested that the reason for these phenotypic changes in the mutants might be the changes in activity of the related to each other regulatory genes controlling virulence and biofilm formation process in cholera agent

БИОРАЗНООБРАЗИЕ ЛУКОВЫХ КУЛЬТУР: ЛУК АФЛАТУНСКИЙ (Allium aflatunense B. Fedtsch.), ЭЛЕМЕНТНЫЙ СОСТАВ

The evaluation of aflatunskiy onion for accumulation level of 25 elements was done. It was found that this crop is a source of potassium, calcium, and phosphorus. It is able to accumulate iodine, magnesium, zinc, ferric, silica. The obtained data shows the nutrition value of the genus of Allium L.Проведена оценка по уровню накопления 25 микроэлементов в луке афлатунском. Выявлено, что кроме высокого содержания калия лук афлатунский является также хорошим источником фосфора и кальция для организма человека. Показано, что лук афлатунский способен накапливать сравнительно высокие концентрации йода. Полученные впервые результаты по определению содержания микроэлементов в луке афлатунском позволяют расширить оценку пищевой значимости рода Allium L. не только как источника калия, кальция, фосфора и магния, но также натрия, цинка, железа и кремния

Оценка образцов лука репчатого (Allium сера L.) различного происхождения в условиях предгорной зоны Северного Кавказа и выделение исходного материала для селекции

Relevance. The success of breeding work is largely determined by the source material, the search and creation of which for target breeding begins with the collection and study of collectible samples for the alignment of morphological features; for the precocity and amity of maturation; for the keeping quality and transportability of bulbs; for the quality of vegetable products (high content of biologically active substances and antioxidants); for resistance to biotic and abiotic stressors of a specific growing zone.Materials and methods. On the basis of the North Caucasus branch FSBSI FSVC, 90 samples of spring onions from 26 countries of the world were evaluated in the number nursery for the period from 2017 to 2019, 71 of them were varieties and 19 were F1 hybrids. In a hybrid nursery, 25 hybrid combinations obtained from FSBSI FSVC (VNIISSOK) were evaluated. The laying and placement of experiments, agricultural techniques of cultivation, accounting and evaluation of economically valuable traits, biochemical analyses were carried out according to generally accepted methods. The standards are the new Primo and Ampex varieties of the selection of the FSBSI FSVC and the Italian F1 hybrid Ranko, which were placed every 10 collection samples.Results.According to the results of the assessment, among the studied F1 varieties and hybrids, sources of economically valuable traits such as yield (20-27 t/ha), precocity (80-90 days), preservation (more than 85%) when laid for long-term storage up to 7 months, purple, white and pink color of bulbs, as well as sources of long-shaped bulbs were identified. The greatest interest for breeding for yield is represented by 9 promising varieties and 9 F1 hybrids of onions of various origins, as well as 4 hybrid combinations that were distinguished by high yields, the yield of marketable products and the mass of marketable bulbs. These samples are recommended for use in the breeding process as sources for the creation of new varieties and hybrids with high yields for the agro-climatic conditions of the foothill zone of the North Caucasus.r breedingАктуальность. Успех селекционной работы, в том числе и на луковых культурах, в значительной мере определяется исходным материалом, поиск и создание которого для селекции начинается со сбора и изучения коллекционных образцов на выравненность морфологических признаков; на скороспелость и дружность созревания; на лежкость и транспортабельность луковиц; на качество продукции (высокое содержание биологически активных веществ и антиоксидантов); на устойчивость к биотическим и абиотическим стрессорам конкретной зоны выращивания.Материалы и методы. На базе Северо–Кавказского филиала ФГБНУ ФНЦО в коллекционном питомнике за период с 2017 по 2019 годы были оценены 90 образцов лука репчатого из 26 стран мира, из них 71 – сорта и 19 – гибриды F1. В гибридном питомнике были оценены 25 гибридных комбинаций, полученных из ФГБНУ ФНЦО (ВНИИССОК). Закладку и размещение опытов, агротехнику возделывания, учеты и оценку хозяйственно ценных признаков проводили согласно общепринятым методикам. Стандарты – новые сорта Примо и Ампэкс селекции ФГБНУ ФНЦО и итальянский гибрид F1 Ранко, которые размещали через каждые 10 коллекционных образцов.Результаты. По итогам проведенной оценки среди изученных сортов и гибридов F1 выделены источники хозяйственно ценных признаков, таких как урожайность (20-27 т/га), скороспелость (80-90 суток), сохранность (более 85%) при длительном хранении до 7 месяцев, фиолетовая, белая и розовая окраска луковиц, а также источники длинной формы луковицы. Наибольший интерес для селекции на урожайность представляют 9 перспективных сортов и 9 гибридов F1 лука репчатого различного происхождения, а также 4 гибридных комбинации, которые отличались высокими показателями урожайности, выходу товарной продукции и массой товарной луковицы. Данные образцы рекомендованы для использования в селекционном процессе в качестве источников создания новых сортов и гибридов с высокой урожайностью для агроклиматических условий предгорной зоны Северного Кавказа

ОЦЕНКА КОЛЛЕКЦИОННОГО ПИТОМНИКА ЧЕСНОКА ОЗИМОГО ПО ХОЗЯЙСТВЕННО ЦЕННЫМ ПРИЗНАКАМ

Garlic is one of the most ancient plants which the person turned to himself on advantage. The larger need for production of garlic for consumption and as raw materials for manufacture of medicinal preparations and, at last, just for use by the population as remedy for many diseases and for the preventive purposes led to the fact that bulk production of garlic in the world makes 24,836 million tons, and the area under garlic reached 1,465 million hectares. n Russia the area under garlic on all categories of farms is 28,4 thousand hectares, and production – 256,406 thousand tons. From factors influencing on the increase production of garlic, one of basic is a sort. Selection of garlic includes improvement of local grades, creation new high-yield, steady against diseases and to wreckers of grades, with the increased content of sugars, essential oils and biologically the active materials. Results of long-term researches by laboratory selection of onions cultures (VNIISSOK) on studying, assessment and selection exemplars grades of garlic winter, collected from different regions of Russia and the CIS countries, on a complex of signs are presented in article (winter hardiness, efficiency, to quality of production, resistance to wreckers and diseases).Чеснок – одно из самых древних растений, которые человек обратил себе на пользу. Большая потребность в продукции чеснока для употребления в пищу и как сырья для изготовления лекарственных препаратов и, наконец, просто для использования населением в качестве лечебного средства от многих заболеваний и для профилактических целей привели к тому, что валовое производство чеснока в мире составляет 24,836 млн т, а площадь под чесноком достигла 1,465 млн га. В России площадь под чесноком по всем категориям хозяйств составляет 28,4 тыс. га, а производство – 256,406 тыс. т. Из факторов, влияющих на повышение производства чеснока, одним из основных является сорт. Селекция чеснока включает улучшение местных сортов, создание новых высокопродуктивных, устойчивых к болезням и вредителям сортов, с повышенным содержанием сахаров, эфирных масел и биологически активных веществ. В статье представлены результаты многолетних исследований лаборатории селекции луковых культур (ФНЦО) по изучению, оценке и выделению сортообразцов чеснока озимого, собранных из разных регионов России и стран СНГ, по комплексу признаков (зимостойкости, продуктивности, качеству продукции, устойчивости к вредителям и болезням. По комплексу хозяйственно ценных признаков выделены сортообразцы No 755, 756, 772, 775, 781, 798, превосходившие стандарт по урожайности, вызреваемости, устойчивости к болезням, лежкости, которые после размножения будут использованы в дальнейшей селекционной работе

Determination of the Degree of Unsaturation in Essential Oils

Being widely used, medicinal products based on vegetable oils require strict regulation and evaluation of quality attributes, determination of shelf-life periods, and monitoring of storage conditions. The most common testing method for unsaturated compounds in vegetable oils is the iodine value determination, which has a range     of limitations. An alternative method for determining the degree of unsaturation is based on epoxidation.The aim of the study was to evaluate the possibility of determining the degree of unsaturation of terpenoids and essential oils using peroxycarboxylic acids.Materials and methods. The authors performed epoxidation of linalool, myrcene, and lemon oil with peroxydecanoic and peroxyoctanoic acids, followed by iodometric titration of the excess acid.Results. The study demonstrated the possibility of measuring the degree of unsaturation of the selected essential oil and terpenoids using peracid epoxidation.   The authors developed a procedure for determining the iodine value of essential oils and calculated the iodine values of linalool, myrcene, and lemon oil. Epoxidation proceeded as a second-order reaction. The authors obtained the following reaction rate constants: 3.9 L×mol–1×min–1 for linalool (298 К), 1.76 L×mol–1×min–1 for myrcene converting to monoxide (298 К), 0.044 L×mol–1×min–1 for myrcene epoxide converting to diepoxide (298 К), and 3.9 L×mol–1×min–1 for lemon oil (297 К).Conclusions. The suggested procedure involving peracid titration for rapid and efficient determination of the degree of unsaturation (iodine value) provides a potential basis for developing a quantification method for total unsaturated bioactive compounds in essential oils

ЭЛЕМЕНТНЫЙ СОСТАВ ЧЕСНОКА ОЗИМОГО (ALLIUM SATIVUM L.) СОРТОВ СЕЛЕКЦИИ ВНИИССОК

Ten varieties of winter garlic were tested for ability to accumulate macroand microelements. Genotype dependence was revealed. The most valuable varieties Strelets, Odintsovskiy Yubileyniy, Podnebesniy, Zaokskiy, and Replikant are characterized by high yield and content of macro- and microelements. The varieties Zaokskiy and Strelets are recommended for next breeding program as an initial breeding material.Проведена оценка десяти сортов чеснока озимого (Allium sativum L.): Дубковский, Юбилейный Грибовский, Заокский, Сармат, Демидов, Поднебесный, Одинцовский Юбилейный, Богатырь, Стрелец по уровню накопления макро- и микроэлементов, установлены сортовые различия. Выявлено, что лидером по накоплению йода является сорт Стрелец, железа – сорт Дубковский. Анализ основных хозяйственно ценных признаков сортов чеснока озимого показал, что наибольший практический интерес имеют сорта Стрелец, Одинцовский Юбилейный, Поднебесный, Заокский и Репликант, которые выделяются как по урожайности, так и по содержанию минеральных веществ. Таким образом, полученные результаты позволяют расширить оценку пищевой значимости чеснока озимого не только как источника калия, кальция, фосфора, магния, натрия, но также железа, цинка, алюминия, кремния, марганца, бора и йода. В качестве исходного материала при селекции на накопление минеральных веществ могут быть использованы сорта Стрелец и Заокский