245 research outputs found
Near-field polarization conversion in planar chiral nanostructures
Enantiomeric-sensitive optical polarization conversion has been observed in the near-field above a planar chiral nanostructures consisting of an array of gammadions cut in a metal film. Formation of the far-field scattered light rotated with respect to the incident linear polarized light has been visualized
Sampling Distributions of Random Electromagnetic Fields in Mesoscopic or Dynamical Systems
We derive the sampling probability density function (pdf) of an ideal
localized random electromagnetic field, its amplitude and intensity in an
electromagnetic environment that is quasi-statically time-varying statistically
homogeneous or static statistically inhomogeneous. The results allow for the
estimation of field statistics and confidence intervals when a single spatial
or temporal stochastic process produces randomization of the field. Results for
both coherent and incoherent detection techniques are derived, for Cartesian,
planar and full-vectorial fields. We show that the functional form of the
sampling pdf depends on whether the random variable is dimensioned (e.g., the
sampled electric field proper) or is expressed in dimensionless standardized or
normalized form (e.g., the sampled electric field divided by its sampled
standard deviation). For dimensioned quantities, the electric field, its
amplitude and intensity exhibit different types of
Bessel sampling pdfs, which differ significantly from the asymptotic
Gauss normal and ensemble pdfs when is relatively
small. By contrast, for the corresponding standardized quantities, Student ,
Fisher-Snedecor and root- sampling pdfs are obtained that exhibit
heavier tails than comparable Bessel pdfs. Statistical uncertainties
obtained from classical small-sample theory for dimensionless quantities are
shown to be overestimated compared to dimensioned quantities. Differences in
the sampling pdfs arising from de-normalization versus de-standardization are
obtained.Comment: 12 pages, 15 figures, accepted for publication in Phys. Rev. E, minor
typos correcte
Using Supply Chain Strategy in Skilled Workers Migration: A Consequence for the Russian Far East’s Economy
Supply chain management in human resource management of the workers in the large scale can be more efficient. Migration of highly skilled workers abroad and to the Russia’s central territories is becoming a significant problem for Primorsky region which located in the key geopolitical zone in the Russian Far East. Every year due to migration losses the population engaged in the economy squeezes by 0.3-0.4 percent. It determines a loss of public services’ quality in healthcare and education, and stipulates a degradation of business environment, which in turn limits the economic advances. Migration losses cause a change in demographic and ethnic structure of employment in the region, which in the long term will determine a structural imbalance in the labor force market. In addition, the outflow of labor force preconditions a slowdown of the economy and diminish the geopolitical status of the Russian Federation in the Far East due to depopulation process at the border’s areas. It can be managed by supply chain strategies to manage the forces properly in their own requirements. Migration of skilled workers, or "brain drain", is a crucial factor for the economy of the Russian Far East. The consequence is a negative impact of migration processes for the age structure of the labor force, considering a fact that the major part of migration, some about 70 %, is due to outflow of the working age’s people. Next consequence is reducing of the engaged population in the economy and, accordingly, shrinking supply of labor resources in the market. The processes of population’s decline and labor migration off the region may squeeze the skilled workers offering in the labor market. Adequacy of qualified specialists will not exceed 40 percent following to the graduates’ forecast of higher and secondary vocational education - 21.0 thousand annually. In this situation a "gap" will probably occur between supply and demand in the labor market as a result of deficit of specialists in long run period
The effect of structural changes on magnetic permeability of amorphous powder Ni80Co20
The structural changes of Ni80Co20 amorphous powder were tested during heating. The alloy was obtained by electrolysis from ammonia solution sulfate of cobalt and nickel on the titanium cathode. The differential scanning calorimetry (DSC) method was used to detect that the crystallization process of powder occurred in two stages with crystallization peaks temperatures of the first stage at 690 K and of the second stage at 790 K. The effect of structural relaxation and crystallization of powder on magnetic properties was predicted by measurement of the relative magnetic permeability change in isothermal and nonisothermal conditions. On the basis of the time change of relative magnetic permeability at a defined temperature in the temperature range of the first and second crystallization peak on the thermogram, the kinetics of crystallization was defined. It was predicted, that in the initial time interval, in the range of the first crystallization peak, the rate of crystallization is determined by the rate of nucleation of the amorphous part of the powder. However, in the second time interval, the crystallization rate is determined by the rate of diffusion. In the range of the second peak, in the beginning the rate of crystal growth is determined by activation energy of the atom pass from smaller to bigger crystal grain. In second time interval, the rate of crystal grain growth is determined by the diffusion rate of atoms to the location of integration into bigger crystal grains. For all processes which determine the rate of crystallization in temperature ranges of both crystallization peaks, the Arrhenius temperature dependence of rate for those processes is obtained. The relative magnetic permeability of crystallized powder at 873 K, is smaller for about 30 % than the relative magnetic permeability of fresh powder at room temperature. However, structurally relaxed powder at 573 K has an about 22 % larger magnetic permeability than the same fresh powder at room temperature
Effect of a nematicidal Bacillus thuringiensis strain on free- living nematodes : 3. Characterization of the intoxication process
La toxicité de #Bacillus thuringiensis est fonction de la température. L'incubation de #Caenorhabditis elegans avec des souches de #B. thuringiensis à 16, 20 et 25°C montre que la toxicité décroît en même temps que la température. A 16°C, la toxicité disparaît complètement, tandis qu'elle atteint son maximum à 25°C. La toxicité, fonction du pH, diminue significativement lorsque les nématodes sont mis en incubation dans des bases faibles (NH4Cl, chloroquine, acridine orange, rouge de méthyle, rouge neutre). A partir de ces résultats, il est possible d'avancer l'hypothèse que l'agent nématicide pénètre à l'intérieur des cellules intestinales, ce qui constitue une différence notable avec les toxines des souches insecticides de #B. thuringiensis lesquelles agissent au niveau de la membrane en brosse. Bien que l'absence de toxine purifiée ne permette pas l'élucidation définitive de son mode d'action, les résultats exposés dans cette troisième, et dernière, partie de la série de publications traitant du sujet, apportent une indication convaincante du fait que les souches nématicides de #B. thuringiensis$ ne peuvent tenir les mêmes promesses que les souches insecticides en tant qu'agent de contrôle biologique. (Résumé d'auteur
Effect of nematicidal Bacillus thuringiensis strains on free- living nematodes : 1. Light microscopic observations, species and biological stage specificity and identification of resistant mutants of Caenorhabditis elegans
L'observation en microscopie optique de l'action toxique des spores/cristaux de #Bacillus thuringiensis montre que, chez #Caenorhabditis elegans, l'intestin est détruit en deux phases sur une période de 24 h. L'anneau antérieur de quatre cellules constitue la première cible. Les observations indiquent que les tissus intestinaux sont les seuls détruits. Le criblage de quatorze autres espèces de Rhabditides vis-à-vis de trois souches nématicides de #B. thuringiensis actives contre #C. elegans a démontré qu'une seule de ces espèces était sensible et indiqué une forte spécificité du facteur nématicide. Cependant, au contraire des toxines de #B. thuringiensis douées de spécificité envers les insectes, les toxines nématicides ne montrent qu'une faible spécificité envers les différents stades de #C. elegans, tous les stades, y compris les adultes, étant sensibles. De plus, la sensibilité s'accroît lors du processus de développement. Deux mutants de #C. elegans envers laquelle elle n'avait pas été testée. Des données préliminaires indiquent que cette réduction de la sensibilité chez les mutants n'est pas causée par une diminution de l'activité de pompage du pharynx. (Résumé d'auteur
Effect of nematicidal Bacillus thuringiensis strains on free-living nematodes : 2. Ultrastructural analysis of the intoxication process in Caenorhabditis elegans
La microscopie électronique par transmission a été utilisée pour décrire l'intoxication de #Caenorhabditis elegans se nourrissant sur des spores/cristaux de #Bacillus thuringiensis. La toxine agit directement sur l'intestin où elle affecte initialement l'anneau de quatre cellules le plus antérieur. En 12 heures, le volume de ces cellules diminue considérablement, les microvillosités régressent lentement, de nombreux organites cellulaires subissent des changements spectaculaires pour être finalement détruits. Il n'a pas été observé de rupture de la membrane cellulaire apicale. Les tissus autres qu'intestinaux n'apparaissent pas affectés. Cette étude révèle des différences ultrastructurales considérables entre le mode d'action des toxines nématicides et celui des cristaux insecticides émanant les uns et les autres de #Bacillus thuringiensis$. (Résumé d'auteur
Региональные вузы и внешняя миграция выпускников: влияние на сферу экономики (на примере Приморского края)
Primorsky krai, a region located in the Far East of Russia, is suffering a deficit with qualified graduates to facilitate the economy processes. There is a gap between the offering of specific staff to advance the economy and ability of local universities to satisfy it. External migration of graduates, so-called “brain drain”, is a deterrent to development of the economy. Approximately 78 percent of the migration flow are the young people under 35. Along the asymmetry of supply and demand due a professional qualification, the tendency of reducing the universities’ graduates leads to a structural imbalance in the labor market. As a result, the region will only partially be able to meet the needs of economy in higher degree employees. Thus, for regional universities is vital to develop educational programs fit the prospective economic spheres, taking the forecast for the economy and the labor market, at least for 5-7 years. The strategic goal for a core regional university is reducing the imbalance in the labor market and providing the economy with specific knowledge and skills. An axial university, or a core regional university, is becoming a research and project center which able transforming the knowledge into a commercial product. It generates a network of partnerships covering the boundaries of the entire economic system of a region.Primorsky krai, una región ubicada en el Lejano Oriente de Rusia, sufre un déficit con graduados calificados para facilitar los procesos económicos. Existe una brecha entre la oferta de personal específico para avanzar en la economía y la capacidad de las universidades locales para satisfacerla. La migración externa de los graduados, llamada "fuga de cerebros", es un elemento disuasorio para el desarrollo de la economía. Aproximadamente el 78 por ciento del flujo migratorio son los jóvenes menores de 35 años. Junto con la asimetría de la oferta y la demanda debido a una calificación profesional, la tendencia a reducir los graduados de las universidades conduce a un desequilibrio estructural en el mercado laboral. Como resultado, la región solo podrá satisfacer parcialmente las necesidades de la economía de los empleados de mayor grado. Por lo tanto, para las universidades regionales es vital desarrollar programas educativos que se ajusten a las esferas económicas prospectivas, tomando el pronóstico para la economía y el mercado laboral, al menos durante 5-7 años. El objetivo estratégico de una universidad regional central es reducir el desequilibrio en el mercado laboral y proporcionar a la economía conocimientos y habilidades específicas. Una universidad axial, o una universidad regional central, se está convirtiendo en un centro de investigación y proyectos que puede transformar el conocimiento en un producto comercial. Genera una red de asociaciones que cubre los límites de todo el sistema económico de una región. Приморский край, регион, расположенный на Дальнем Востоке России, испытывает дефицит квалифицированных выпускников для содействия экономическим процессам. Существует разрыв между предложением конкретных сотрудников для развития экономики и способностью местных университетов ее удовлетворить. Внешняя миграция выпускников, так называемая «утечка мозгов», является сдерживающим фактором для развития экономики. Приблизительно 78 процентов миграционного потока составляют молодые люди в возрасте до 35 лет. Наряду с асимметрией спроса и предложения, обусловленной профессиональной квалификацией, тенденция сокращения числа выпускников университетов приводит к структурному дисбалансу на рынке труда. В результате регион сможет лишь частично удовлетворить потребности экономики в работниках высшей степени. Таким образом, для региональных вузов жизненно важно разработать образовательные программы, подходящие для перспективных сфер экономики, принимая прогноз по экономике и рынку труда, по крайней мере, на 5-7 лет. Стратегической целью основного регионального университета является снижение дисбаланса на рынке труда и обеспечение экономики конкретными знаниями и навыками. Осевой университет, или основной региональный университет, становится исследовательским и проектным центром, способным превращать знания в коммерческий продукт. Он создает сеть партнерских отношений, охватывающих границы всей экономической системы региона
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