Computing eigenvalues occuring in continuation methods with the Jacobi-Davidson QZ method

Continuation methods are a well-known technique for computing several stationary solutions of problems involving one or more physical parameters. In order to determine whether a stationary solution is stable, and to detect the bifurcation points of the problem, one has to compute the rightmost eigenvalues of a related, generalized eigenvalue problem. The recently developed Jacobi-Davidson QZ method can be very eective for computing several eigenvalues of a given generalized eigenvalue problem. In this paper we will explain how the Jacobi-Davidson QZ method can be used to compute the eigenvalues needed in the application of continuation methods. As an illustration, the two-dimensional Rayleigh-Benard problem has been studied, with the Rayleigh number as a physical parameter. We investigated the stability of stationary solutions, and several bifurcation points have been detected. The Jacobi-Davidson QZ method turns out to be very ecient for this problem

Complete parameterization, and invariance, of diffusive quantum trajectories for Markovian open systems

The state matrix $\rho$ for an open quantum system with Markovian evolution obeys a master equation. The master equation evolution can be unraveled into stochastic nonlinear trajectories for a pure state $P$, such that on average $P$ reproduces $\rho$. Here we give for the first time a complete parameterization of all diffusive unravelings (in which $P$ evolves continuously but non-differentiably in time). We give an explicit measurement theory interpretation for these quantum trajectories, in terms of monitoring the system's environment. We also introduce new classes of diffusive unravelings that are invariant under the linear operator transformations under which the master equation is invariant. We illustrate these invariant unravelings by numerical simulations. Finally, we discuss generalized gauge transformations as a method of connecting apparently disparate descriptions of the same trajectories by stochastic Schr\"odinger equations, and their invariance properties.Comment: 10 pages, including 5 figures, submitted to J. Chem Phys special issue on open quantum system

Improved proteomic analysis of nuclear proteins, as exemplified by the comparison of two myelo\"id cell lines nuclear proteomes

One of the challenges of the proteomic analysis by 2D-gel is to visualize the low abundance proteins, particularly those localized in organelles. An additional problem with nuclear proteins lies in their strong interaction with nuclear acids. Several experimental procedures have been tested to increase, in the nuclear extract, the ratio of nuclear proteins compared to contaminant proteins, and also to obtain reproducible conditions compatible with 2D-gel electrophoresis. The NaCl procedure has been chosen. To test the interest of this procedure, the nuclear protein expression profiles of macrophages and dendritic cells have been compared with a proteomic approach by 2D-gel electrophoresis. Delta 2D software and mass spectrometry analyses have allowed pointing out some proteins of interest. We have chosen some of them, involved in transcriptional regulation and/or chromatin structure for further validations. The immunoblotting experiments have shown that most of observed changes are due to post-translational modifications, thereby a exemplifying the interest of the 2D gel approach. Finally, this approach allowed us to reach not only high abundance nuclear proteins but also lower abundance proteins, such as the HP1 proteins and reinforces the interest of using 2DE-gel in proteomics because of its ability to visualize intact proteins with their modifications

Ethnic density in school classes and adolescent mental health

OBJECTIVE: The present study set out to examine the association between ethnic composition of school classes and prevalence of internalising and externalising problem behaviour among ethnic minority and majority students. METHODS: Data were derived from the Dutch 2002 Health Behaviour in School-aged Children (HBSC) survey, a nationally representative cross-sectional study with a total of 5,730 adolescents, aged 11–18 and attending secondary school, of which 931 belong to ethnic minority groups. The data were analysed using a multilevel regression model. RESULTS: The study revealed that, after taking individual characteristics like age, gender, educational level and family affluence into account, ethnic minority students on average report higher levels of externalising but not internalising problems. Ethnic density on the level of school classes modified this difference, as a negative association between the proportion ethnic minority students in class and externalising problem behaviour was found, but only for ethnic minority students. No effect of ethnic composition was found with respect to internalising problem behaviour. CONCLUSION: The data revealed that ethnic minority students report higher levels of externalising problem behaviour, but only in classes with a minority of ethnic minority students and not in classes with a culturally diverse composition. This points towards a possible beneficial effect of a more culturally diverse environment for minority students. Majority students appeared to be insensitive for the ethnic density effect. Future studies should investigate the role of the ethnic composition of the school class more in-depth

Сучасна лексикографія як об’єкт лінгвістики

У статті проаналізовано сучасні праці теоретичної лексикографії, розглянуто погляди науковців на дефініцію терміна “лексикографія”.The article gives the analysis of contemporary works on theoretical lexicography and rewiews the approaches of different scientists to the term “lexicography”

Substance use by adolescents in special education and residential youth care institutions

This study examined substance use rates and related background factors among adolescents in special education (SE) and in residential youth care institutions (RYC). Information on substance use from 531 adolescents in RYC, 603 adolescents in SE for students with behavioral problems (SEB) and 1,905 adolescents in SE for students with learning disabilities (SEL) was compared with information from 7,041 adolescents who attended mainstream education. Results show that substance use rates are particularly high among adolescents in RYC and in SEB. For example, 22% of the 12–13 years old in RYC and 16% in SEB was a daily smoker compared with 1% of their counterparts in mainstream education. Background factors, including age, ethnic background and family situation, partly explained the differences in substance use between mainstream education on the one hand and SE and RYC on the other hand, but differences between the groups remained substantial and significant. Several interaction effects were found in the relation between SE/RYC and substance use that were all in line with the risk paradox: some subgroups that are normally at lower risk for problem behavior are at higher risk when they are subjected to high-risk indicators. The elevated risk of substance use among adolescents in RYC/SE was in some cases particularly marked for those who would normally be at lower risk for substance use (girls in SEB for heavy alcohol drinking and cannabis use, ethnic minority adolescents and adolescents with a stable family situation in RYC for respectively heavy weekly alcohol drinking and daily use of tobacco). Results of this study have important implications for health education and intervention programs for adolescents in RYC and SE

Проблемы феминизма в творчестве О.А. Шапир

В статье анализируются феминистические идеи О. Шапир, изложенные в публицистических, литературно-критических статьях, воплощенные в женских образах художественных призведений.У статті аналізуються феміністичні ідеї О. Шапір, викладені в публіцистиці, в літературно-критичних статтях, втілені в жіночих образах художніх творів.The given article dwells upon the feministic ideas of O. Shapir represented in publicistics and literary criticism and embodied in female characters of her worle