Specular nonlinear anisotropic polarization effect along fourfold crystal symmetry axes

We present what is to our knowledge the first experimental observation of the specular nonlinear anisotropic polarization effect of a pump-induced polarization-plane rotation for normal-incidence reflection from the (001) surface of a cubic crystal. In GaAs, azimuth rotation of the order of 9 × 10-6 rad is seen for a pump intensity of 75 MW/cm2 at 750 nm, from which the anisotropic component of the cubic nonlinearity |Re(χxxxx - 2χxxyy - χxyyx)| = 5 × 10-9 esu is found.<br/

Creation of an Electronic Textbook for University Students

The need for e-learning in modern Russia is caused by the rapid development of informatization, digitalization, information and communication technologies, the creation of a global environment for mutual integration of cultures and disciplines, as well as the formation of open continuous education, which is the basis of a post-industrial (information) society. These processes stimulate an active search for creative educational practices that meet the requirements of the information society. A modern specialist must have a certain amount of knowledge that will allow him to learn constantly, improve his skills and abilities, self-develop and self-actualize in order to keep up with the time of changes in the information society. In the framework of the modern educational paradigm, the student is considered as a subject of knowledge, not an object of pedagogical influence. In the early – mid-2010s, this is actively promoted by electronic learning (e-learning, EL), which should be used in various educational organizations. E-learning allows integrating into the world scientific community, becoming subjects of interaction between cultures, including the exchange of spiritual values. Implementation of EL is one of the key tasks in the context of modernization of national education. The term “electronic learning” is translated into Russian in various ways. The most popular options are: “distance learning/education”, “mobile learning”, and “virtual learning”. The European Commission interprets “e-learning” as “using new multimedia and Internet technologies to improve the quality of learning by improving access to resources and services, as well as remote knowledge sharing and collaboration”. In this study, the concept of “e-learning” will correspond to the phrase “electronic learning”. This is an educational process based on interactive electronic means of storing and providing information: the Internet, corporate networks, and CDs

Creation of an Electronic Textbook for University Students

The need for e-learning in modern Russia is caused by the rapid development of informatization, digitalization, information and communication technologies, the creation of a global environment for mutual integration of cultures and disciplines, as well as the formation of open continuous education, which is the basis of a post-industrial (information) society. These processes stimulate an active search for creative educational practices that meet the requirements of the information society. A modern specialist must have a certain amount of knowledge that will allow him to learn constantly, improve his skills and abilities, self-develop and self-actualize in order to keep up with the time of changes in the information society. In the framework of the modern educational paradigm, the student is considered as a subject of knowledge, not an object of pedagogical influence. In the early – mid-2010s, this is actively promoted by electronic learning (e-learning, EL), which should be used in various educational organizations. E-learning allows integrating into the world scientific community, becoming subjects of interaction between cultures, including the exchange of spiritual values. Implementation of EL is one of the key tasks in the context of modernization of national education. The term “electronic learning” is translated into Russian in various ways. The most popular options are: “distance learning/education”, “mobile learning”, and “virtual learning”. The European Commission interprets “e-learning” as “using new multimedia and Internet technologies to improve the quality of learning by improving access to resources and services, as well as remote knowledge sharing and collaboration”. In this study, the concept of “e-learning” will correspond to the phrase “electronic learning”. This is an educational process based on interactive electronic means of storing and providing information: the Internet, corporate networks, and CDs

Creation of an Electronic Textbook for University Students

The need for e-learning in modern Russia is caused by the rapid development of informatization, digitalization, information and communication technologies, the creation of a global environment for mutual integration of cultures and disciplines, as well as the formation of open continuous education, which is the basis of a post-industrial (information) society. These processes stimulate an active search for creative educational practices that meet the requirements of the information society. A modern specialist must have a certain amount of knowledge that will allow him to learn constantly, improve his skills and abilities, self-develop and self-actualize in order to keep up with the time of changes in the information society. In the framework of the modern educational paradigm, the student is considered as a subject of knowledge, not an object of pedagogical influence. In the early – mid-2010s, this is actively promoted by electronic learning (e-learning, EL), which should be used in various educational organizations. E-learning allows integrating into the world scientific community, becoming subjects of interaction between cultures, including the exchange of spiritual values. Implementation of EL is one of the key tasks in the context of modernization of national education. The term “electronic learning” is translated into Russian in various ways. The most popular options are: “distance learning/education”, “mobile learning”, and “virtual learning”. The European Commission interprets “e-learning” as “using new multimedia and Internet technologies to improve the quality of learning by improving access to resources and services, as well as remote knowledge sharing and collaboration”. In this study, the concept of “e-learning” will correspond to the phrase “electronic learning”. This is an educational process based on interactive electronic means of storing and providing information: the Internet, corporate networks, and CDs

THE GENERATION OF CODING SEQUENCES OF CELLULAR GENOME THROUGH COOPTION OF VIRAL GENES

This review attempts to summarize the available data concerning the influence of viruses on the generation of the cellular genome coding genes content. For a long time endogenous retroviruses have been considered as selfish elements of the organism genome. But now there is growing evidence that endogenous retroviruses are more than genome junk and can serve as source for new coding sequences allowing organism evolution. Many genes derived from retroviruses have been identified in eukaryote through comparative genomics and functional analyses. In particular, genes derived from gag structural protein and envelope (env) genes, as well as from the integrase-coding and protease-coding sequences, have been identified in humans and other vertebrates. It has been proved that a number of these genes fulfill essential functions for the development and survival of their host. One of the best known co-opted retroviral genes encoded syncytin plays a key role in the placenta development. It is interesting that during mammalian evolution retroviral envelope genes have been domesticated several times independently to generate syncytin. The activity-regulated cytoskeletal protein Arc is important for cognitive functions and memory formation. Arc was one of over 100 human proteins that have been ‘‘domesticated’’ from the retrotransposon remains of ancient viruses. A number of genes that code the transcription factors have emerged as a result of “taming” the viral genes by the host organism. Now growing evidence reveals that not only retroviruses but other RNA viruses are reverse-transcribed and integrated into the genome of infected cells. It has been recently demonstrated that all Homo sapiens bornavirus like nucleoproteins (EBLN) are expressed in at least one tissue and consequently may have function.The co-option of the viral sequences not only can lead to the major evolutionary innovations, but also is able to create interspecies polymorphism.What it has been described here is probably only the tip of the iceberg, and future genome analyses will certainly uncover new virus-derived genes

The N-methyl-d-aspartate receptor antagonist CPP alters synapse and spine structure and impairs long-term potentiation and long-term depression induced morphological plasticity in dentate gyrus of the awake rat

Long-term morphological synaptic changes associated with homosynaptic long-term potentiation (LTP) and heterosynaptic long-term depression (LTD) in vivo, in awake adult rats were analyzed using three-dimensional (3-D) reconstructions of electron microscope images of ultrathin serial sections from the molecular layer of the dentate gyrus. For the first time in morphological studies, the specificity of the effects of LTP and LTD on both spine and synapse ultrastructure was determined using an N-methyl-d-aspartate (NMDA) receptor antagonist CPP (3-[(R)-2-carboxypiperazin-4-yl]-propyl-1-phosphonic acid). There were no differences in synaptic density 24 h after LTP or LTD induction, and CPP alone had no effect on synaptic density. LTP increased significantly the proportion of mushroom spines, whereas LTD increased the proportion of thin spines, and both LTP and LTD decreased stubby spine number. Both LTP and LTD increased significantly spine head evaginations (spinules) into synaptic boutons and CPP blocked these changes. Synaptic boutons were smaller after LTD, indicating a pre-synaptic effect. Interestingly, CPP alone decreased bouton and mushroom spine volumes, as well as post-synaptic density (PSD) volume of mushroom spines.These data show similarities, but also some clear differences, between the effects of LTP and LTD on spine and synaptic morphology. Although CPP blocks both LTP and LTD, and impairs most morphological changes in spines and synapses, CPP alone was shown to exert effects on aspects of spine and synaptic structure

Биологические средства защиты растений в борьбе с фитопаразитическими нематодами, другими патогенами и перспективы их использования в XXI веке

Different strains of antagonistic bacteria and fungi have been actively tested for the last several years in order to discover their complex fungicidal, bactericidal and nematicidal activity in different plant communities and regions of Russia. This work is targeted for elaboration of environmentally friendly and energy-saving methods of plant protection. Bacterial strains of Pseudomonas and Bacillus, that possess not only fungicidal but also bactericidal and nematicidal effects, were revealed in the results of pot, laboratory and field experiments. These strains could regulate the number of virus-vector nematodes of Longidoridae and Trichodoridae and their associated viruses. Also, the strains could be shown to stimulate plant growth and high yield of different varieties of test-plants. They should be considered to be the natural regulators of the quantity and the distribution of parasites. This work was supported by grant RFFI 05-04-49237.С целью разработки экологически безопасных и энергосберегающих способов защиты растений в последние годы интенсивно изучаются коллекции штаммов бактерий и грибов-антагонистов, обладающих комплексной фунгицидной, бактерицидной и нематицидной активностью. Проводится их поиск в различных фитоценозах и регионах России. В результате лабораторных, вегетационных и полевых исследований впервые выделены штаммы бактерий из родов Pseudomonas и Bacillus, обладающие не только фунгицидным, бактерицидным и нематицидным эффектами, регулирующими численность нематод-вирусоносителей, но и антивирусным действием, включая вирусы, переносимые нематодами-лонгидоридами и триходоридами. Выделенные штаммы обладают стимулирующим действием на рост, вегетативную продуктивность и урожай различных видов тест-растений. Они могут рассматриваться в качестве природных регуляторов, снижающих численность и распространение в различных почвенных биоценозах нематод-вирусоносителей

Radial thermal expansion of pure and Xe-saturated bundles of single-walled carbon nanotubes at low temperatures

The radial thermal expansion coefficient ar of pure and Xe-saturated bundles of single-walled carbon nanotubes (CNT) has been measured in the interval 2.2-120 K. The coefficient is positive above T = 5.5 K and negative at lower temperatures. The experiment was made using a low-temperature capacitance dilatometer with a sensitivity of 2·10⁻⁹ cm and the sample was prepared by compacting a CNT powder such that the pressure applied oriented the nanotube axes perpendicular to the axis of the cylindrical sample. The data show that individual nanotubes have a negative thermal expansion while the solid compacted material has a positive expansion coefficient due to expansion of the intertube volume in the bundles. Doping the nanotubes with Xe caused a sharp increase in the magnitude of ar in the whole range of temperatures used, and a peak in the dependence ar(T) in the interval 50-65 K. A subsequent decrease in the Xe concentration lowered the peak considerably but had little effect on the thermal expansion coefficient of the sample outside the region of the peak. The features revealed have been explained qualitatively

Measurement of xF3xF_3 and F2F_2 Structure Functions in Low Q2Q^2 Region with the IHEP-JINR Neutrino Detector

The isoscalar structure functions $xF_3$ and $F_2$ are measured as functions of $x$ averaged over all $Q^2$ permissible for the range of 6 to 28 GeV of incident neutrino (anti-neutrino) energy at the IHEP-JINR Neutrino Detector. The QCD analysis of $xF_3$ structure function provides $\Lambda_{\bar{MS}}^{(4)} = (411 \pm 200)$ MeV under the assumption of QCD validity in the region of low $Q^2$. The corresponding value of the strong interaction constant $\alpha_S (M_Z) = 0.123^{+0.010}_{-0.013}$ agrees with the recent result of the CCFR collaboration and with the combined LEP/SLC result.Comment: 11 pages, 1 Postscript figure, LaTeX. Talk given at the 7th International Workshop on Deep Inelastic Scattering and QCD (DIS 99), Zeuthen, Germany, 19-23 Apr 199