Photon correlations for colloidal nanocrystals and their clusters

Images of semiconductor `dot in rods' and their small clusters are studied by measuring the second-order correlation function with a spatially resolving ICCD camera. This measurement allows one to distinguish between a single dot and a cluster and, to a certain extent, to estimate the number of dots in a cluster. A more advanced measurement is proposed, based on higher-order correlations, enabling more accurate determination of the number of dots in a small cluster. Nonclassical features of the light emitted by such a cluster are analyzed.Comment: 4 pages, 4 figure

Photon correlations for colloidal nanocrystals and their clusters

Images of semiconductor “dot-in-rods” and their small clusters are studied by measuring the second-order correlation function with a spatially resolving intensified CCD camera. This measurement allows one to distinguish between a single dot and a cluster and, to a certain extent, to estimate the number of dots in a cluster. A more advanced measurement is proposed, based on higher-order correlations, enabling more accurate determination of the number of dots in a small cluster. Nonclassical features of the light emitted by such a cluster are analyzed

General properties of overlap probability distributions in disordered spin systems. Toward Parisi ultrametricity

For a very general class of probability distributions in disordered Ising spin systems, in the thermodynamical limit, we prove the following property for overlaps among real replicas. Consider the overlaps among s replicas. Add one replica s+1. Then, the overlap q(a,s+1) between one of the first s replicas, let us say a, and the added s+1 is either independent of the former ones, or it is identical to one of the overlaps q(a,b), with b running among the first s replicas, excluding a. Each of these cases has equal probability 1/s.Comment: LaTeX2e, 11 pages. Submitted to Journal of Physics A: Mathematical and General. Also available at http://rerumnatura.zool.su.se/stefano/ms/ghigu.p

On universality of local edge regime for the deformed Gaussian Unitary Ensemble

We consider the deformed Gaussian ensemble $H_n=H_n^{(0)}+M_n$ in which $H_n^{(0)}$ is a hermitian matrix (possibly random) and $M_n$ is the Gaussian unitary random matrix (GUE) independent of $H_n^{(0)}$. Assuming that the Normalized Counting Measure of $H_n^{(0)}$ converges weakly (in probability if random) to a non-random measure $N^{(0)}$ with a bounded support and assuming some conditions on the convergence rate, we prove universality of the local eigenvalue statistics near the edge of the limiting spectrum of $H_n$.Comment: 25 pages, 2 figure

Bulk Universality and Related Properties of Hermitian Matrix Models

We give a new proof of universality properties in the bulk of spectrum of the hermitian matrix models, assuming that the potential that determines the model is globally $C^{2}$ and locally $C^{3}$ function (see Theorem \ref{t:U.t1}). The proof as our previous proof in \cite{Pa-Sh:97} is based on the orthogonal polynomial techniques but does not use asymptotics of orthogonal polynomials. Rather, we obtain the $sin$-kernel as a unique solution of a certain non-linear integro-differential equation that follows from the determinant formulas for the correlation functions of the model. We also give a simplified and strengthened version of paper \cite{BPS:95} on the existence and properties of the limiting Normalized Counting Measure of eigenvalues. We use these results in the proof of universality and we believe that they are of independent interest

Educational and cognitive independence of students in e-learning

Topicality of the topic is driven by the changed social and economic conditions in Russia, that led to the search for educational paradigms adequate to the new social and economic development of the country, and by the rapid growth of the role of information technologies as well as by the need to improve the professionalism of teachers in their use of computer technologies in education. The aim of the article is to draw the attention of the pedagogical community to the actual forms of e-learning in modern educational practice of Russian education. The leading approach to the study of this problem is the analysis of world and Russian experience of using e-learning in order to strengthen the independence of students. The recommendations on the implementation of e-learning in the context of Russian education were suggested as the result of the research. The material of the article can be useful for teachers seeking to apply modern methods and technologies of teaching. © Authors

Ghrelin suppresses insulin secretion in human islets and type 2 diabetes patients have diminished islet ghrelin cell number and lower plasma ghrelin levels

Peer reviewe

Postural disorders of neurological genesis in elderly patients: pathogenesis and features of diagnostics (literature review)

Walking and balance disorders in elderly patients are the most common manifestations of various diseases of the nervous system. Balance imbalance is the leading cause of injuries in the elderly, leading to a limitation of both the patient’s ability to work and communication in the social environment, which in particular cases leads to a loss of independence, reducing the quality of life. Walking disorders are an important, difficult to resolve medical and social problem. The aim of the study was to identify the physiological and clinical aspects of age-related gait disorders with an emphasis on neurological pathogenetic causes. A detailed study of modern foreign medical literature and current international clinical guidelines was carried out with further systematization of the data obtained. Falls in the elderly are a common and major factor that threatens the independence of older people. The frequency of falls increases with age. Treatment for fall injuries does not always include identifying the cause of the fall. In the elderly, loss of balance is most commonly due to multiple causes, including impending threat to the homeostatic mechanisms that maintain postural stability combined with age-related impairments in balance, gait stability, and cardiovascular function. Gait disorders are a major cause of functional impairment and morbidity in the elderly. Most gait disorders in the elderly are multifactorial and have neurological components. In developed countries, there is a trend towards aging of the population: the percentage component of the elderly part of the population is growing. It is violations of balance, stability and walking, to a large extent, that lead to the inability of the patient to provide his quality of life at a satisfactory level on his own, to disability and failure in the workplace. Early diagnosis of gait disorders can prevent premature disability and limit the independence of elderly patients. It is important to note that a history of falls is a predictor of the risk of new falls