Negative magnetoresistance in the nearest-neighbour hopping conduction in granular gold film

The low temperature (0.5-55 K) conduction of semicontinuous gold film vacuum deposited at T \approx 50 K is studied. The film is near the percolation threshold (thickness 3.25 nm). Its resistance is extremely sensitive to the applied voltage U. At low enough U the film behaves as an insulator (two-dimensional granular metal). In this state the dependences R(T) \propto \exp (1/T) (for T \leq 20 K) and R(U) \propto \exp (1/U)) (for T \leq 1 K and U > 0.1 V) are observed. Magnetoresistance (MR) is negative and can be described by \Delta R(H)/R(0) \propto -H^2/T. This negative MR which manifests itself for nearest-neighbour hopping is rather uncommon and, up to now, has not been clarified. The possible mechanisms of such case of negative MR are discussed.Comment: 9 pages, LATEX, 6 figures. To be published in Physica B. Fig.4 is JPG file, in case of troubles with it, appeal for help and advice to: [email protected]

Expression of Arabidopsis gdh2 gene depends on activity of alternative electron transfer pathway in mitochondria

Aim. We studied the expression level of gdh2 gene, encoding subunit of mitochondrial glutamate dehydrogenase, in Arabidopsis suspension culture cells with genetically modified level of alternative oxidase AOX1a. Methods. Polymerase chain reaction, Northern-blotting. Results. The treatment with main electron transfer pathway inhibitor antimycin A led to an increase in gdh2 transcript level in the wild-type cells and the cells with decreased level of alternative oxidase, but not in the cells with elevated level of alternative oxidase. Conclusions. It is known that an increase in alternative oxidase level in the plant cell results in more oxidized state of ubiquinone pool in respiratory chain. Therefore, the obtained results support the earlier proposed model according to which the expression level of gdh2 gene depends on the redox state of ubiquinone pool. Keywords: Arabidopsis thaliana, electron transport chain, alternative oxidase, glutamate dehydrogenase, antimycin A.Цель. Исследование уровня экспрессии гена gdh2, кодирующего субъединицу митохондриальной глутаматдегидрогеназы, в суспензионных культурах клеток арабидопсиса с генетически модифицированным уровнем альтернативной оксидазы AOX1a. Методы. Полимеразная цепная реакция, Нозерн-блоттинг. Результаты. Показано, что при обработке ингибитором основного пути переноса электронов антимицином А содержание транскриптов gdh2 возрастает в клетках дикого типа и в клетках со сниженным уровнем альтернативной оксидазы, однако остается неизменным в клетках с ее повышенным содержанием. Выводы. Поскольку увеличенный уровень альтернативной оксидазы приводит к уменьшению степени восстановленности пула убихинона в дыхательной цепи, полученные результаты свидетельствуют в пользу модели, согласно которой уровень экспрессии гена gdh2 зависит от редокс-состояния убихинонового пула. Ключевые слова: Arabidopsis thaliana, электронно-транспортная цепь, альтернативная оксидаза, глутаматдегидрогеназа, антимицин А.Мета. Дослідити рівень експресії гена gdh2, кодуючого субодиницю мітохондріальної глутаматдегідрогенази, у суспензійних культурах клітин арабідопсису з генетично модифікованим рівнем альтернативної оксидази AOX1a. Методи. Полімеразна ланцюгова реакція. Результати. Показано, що за обробки інгібітором основного шляху перенесення електронів антиміцином А вміст транскриптів gdh2 зростає у клітинах дикого типу і в клітинах зі зниженим рівнем альтернативної оксидази, однак він лишається незмінним у клітинах з її підвищеним вмістом. Висновки. Оскільки збільшений рівень альтернативної оксидази спричиняє зменшення ступеня відновлення пулу убіхінону у дихальному ланцюгу, отримані резудбтати свідчать на користь моделі, згідно з якою рівень експресії гена gdh2 залежить від редокс-стану убіхінонового пулу. Ключові слова: Arabidopsis thaliana, електронно-транспортний ланцюг, альтернативна оксидаза, глутаматдегідрогеназа, антиміцин А

Monitoring of Fine Dust Pollution of Multistory Buildings Air Environment as an Adoption Factor of Town-planning Decisions

AbstractIt is important to carry out the environmental monitoring during the construction of facilities in the urban areas. The article represents the research of the indoor air of a higher educational institution in relation to existence of such contaminants as the particulate matter of PM2.5 and PM10. Samples were taken on all floors at several academic buildings of a higher educational institution from September to November 2014 and from March to May 2015. As a result of the research, the regression dependence was obtained, indicating interrelation of the distribution of dust particles PM2.5 and PM10 and the particulate matter with the building height. Thus, the maximum size of the dust particles is detected at 1-4 floors of rooms, on the upper floors a smaller diameter of particles is observed. It is revealed that dust particle diameter decreases when the building height increases.The findings confirm the relevance of the further research as for the problems of an assessment of influence of dust emissions on the public health and the development of measures for the indoor air quality improvement as well as for the problems of the ventilation and air cleaning modernization at a design stage of facilities’ construction and their placement under the conditions of urban development

Dosing of exercises in improving the technology of swimming at schoolchildren

Rational distribution of muscular effort in the aquatic environment not only contributes to the optimization of swimming techniques, but also contributes to the improvement of athletic performance. [2]. Swimmer movement is a system of repetitive cycles. The cycle of arm movement is divided into phases: 1 – capture water; 2 – tightening the body to the fulcrum; 3 - repulsion; 4 - extraction the hand from the water; 5 - arm movement above water; 6 - putting the hand into the water [1]. The boundaries of the phases are the moments of change in the direction of movement of the brush. Purpose. The aim of the work is to optimize the structure of swimming technique for schoolchildren, taking into account the age-related features of the formation of swimming movements

Self-stochasticity in deterministic boundary value problems

This paper presents the experience of applying dynamical systems theory to an investigation into nonlinear boundary value problems for partial differential equations (PDE for short) in the case that their solutions become chaotic with time. To describe the long time behavior of such solutions, the concept of self-stochasticity had been suggested. The results reported in this work are concerned linear systems of PDE with nonlinear boundary conditions; general ideas on the manner in which chaotic solutions may be described are set forth by the example of several simplest boundary value problems

Differentiated Approach to Learning in Higher Education

AbstractThe relevance of this work is determined by the fact that due to the increasing demands for professional development of specialists it is necessary to apply such approaches to teaching so that students of all learning levels could fully understand the material. In order to create optimal learning conditions for students the use of a differentiated approach to the educational process is presented in the paper. For its realization the introduction of level differentiation and differentiated module-rating system was suggested.In this paper we define the conditions for the implementation of level differentiation, describe the developed training complex containing multilevel tasks, variants of control tests with a choice of difficulty levels. To assist the students to choose the difficulty level a web application was designed. Differentiated module-rating system is a modification of the rating system. It is distinguished by the method of counting ranking: at the end of the semester the student has a range of individual private ratings considered in the exam. Differentiated module-rating system allows them to get an idea of the level of learning the material under study and make the necessary adjustments.The introduction of a differentiated approach into the educational process helps to individualize the learning process of students, contributes to a more lasting and deeper acquiring of knowledge, the formation of positive motivation to learning, creation of a comfortable learning environment, building students’ self-esteem and making them more autonomous

On kinetic formulation of first-order hyperbolic quasilinear systems

We give kinetic formulation of measure valued and strong measure valued solutions to the Cauchy problem for a first-order quasilinear equation. For the corresponding kinetic equation the class of existence and uniqueness to the Cauchy problem is extracted. This class consists of so-called entropy solutions, which correspond to strong measure valued solutions of the original problem. In the last section we generalized these results to the case of symmetric generally nonconservative multidimensional systems and introduce the notion of a strong measure valued solution, based only on the kinetic approach under consideration

THE EFFECT OF PSEUDOMONAS AERUGINOSA SIGNAL QUINOLONE ON THE RHAMNOLIPIDS BIOSYNTHESIS AND RHAMNOSYLTRANSFERASE 2ACTIVITY

Aim: Discovery of the P. aeruginosa ONU 302rhamnolipids biosynthesis andrhamnosyltransferase 2 activity in presence of the Pseudomonas aeruginosaexogenous quorum sensing signal molecule2-heptyl-3-hydroxy-4-quinolon (PQS). Methods. Pseudomonas aeruginosa ONU 302were cultured in the Giss medium with 2% glucose at 37оС 24 h. All discoveries were performed in "plancton-biofilm" system with using of the «Nunclon» 48-well plates. Di- and monorhamnolipids separation conducted by TLC methods and its content was determined by orcinol test. Rhamnosyltransferase 2 (RhlC) activity was analysed in P.aeruginosa cell extracts using arhamnosyltransferase assayspecific for the addition of L-rhamnose to monorhamnolipid. Results. The synthesis of rhamnolipids in control culture is activated from the early stationary phase and the content of the biosurfactants is increasedfivefold up 10 to 24 hour – up 0.66 to 3.44 mg/ml. Addition of increasing concentrations of PQS did not affect the growth ofP.aeruginosa but were enhanced rhamnolipids content and dirhamnolipids proportion in the biosurfactants mixture. After 24 hours total biosurfactant level in culture medium in the presence of 80 μМ PQS was 3.7 times higher compared with the control. The dirhamnolipid/monorhamnolipid ratio was 2.2 times higher. The additions of PQS at the time of inoculation are sufficient to induce RhlC activity during the transition to stationary phase.So, after 24 hours in the presence of 40, 60 or 80 μМ PQS rhamnosyltransferase 2 activity was higher at 40%, 70% and 120%, respectively, as compared with the control