Magnetotransport in wide parabolic PbTe quantum wells

The 3D- and 2D- behaviour of wide parabolic PbTe single quantum wells, which consist of PbTe p-n-p-structures, are studied theoretically and experimentally. A simple model combines the 2D- subband levels and the 3D-Landau levels in order to calculate the density of states in a magnetic field perpendicular to the 2D plane. It is shown that at a channel width of about 300nm on can expect to observe 3D- and 2D-behaviour at the same time. Magnetotransport experiments in selectively contacted Hall bar samples are performed at temperatures down to T = 50 mK and at magnetic fields up to B = 17 T.Comment: postscript file including 2 figs, 4 pages, Paper presented at EP2DS-XI, Nottingham 199

Protein synthesis at synaptic sites on dendrites

Studies over the past 20 years have revealed that gene expression in neurons is carried out by a distributed network of translational machinery. One component of this network is localized in dendrites, where polyribosomes and associated membranous elements are positioned beneath synapses and translate a particular population of dendritic mRNAs. The localization of translation machinery and mRNAs at synapses endows individual synapses with the capability to independently control synaptic strength through the local synthesis of proteins. The present review discusses recent studies linking synaptic plasticity to dendritic protein synthesis and mRNA trafficking and considers how these processes are regulated. We summarize recent information about how synaptic signaling is coupled to local translation and to the delivery of newly transcribed mRNAs to activated synaptic sites and how local translation may play a role in activity-dependent synaptic modification

Gauge invariant effective action for the Polyakov line in the SU(N) Yang--Mills theory at high temperatures

We integrate out fast varying quantum fluctuations around static A_4 and A_i fields for the SU(N) gauge group. By assuming that the gluon fields are slowly varying but allowing for an arbitrary amplitude of A_4 we obtain two variants of the effective high-temperature theory for the Polyakov line. One is the effective action for the gauge-invariant eigenvalues of the Polyakov line, and it is explicitly Z(N) symmetric. The other is the effective action for the Polyakov line itself as an element of the SU(N). In this case the theory necessarily includes the spatial components A_i to ensure its gauge invariance under spatial gauge transformations. We derive the 1-loop effective action in the `electric' and `magnetic' sectors, summing up all powers of A_4.Comment: RevTex4, 2 figure

Selective Self-Stereotyping and Women’s Self-Esteem Maintenance

The process and implications of gender-based self-stereotyping are examined in this paper. Women displayed a tendency to selectively self-stereotype for personality and physical traits such that they endorsed positive stereotypic traits and denied negative traits as descriptive of the self and closest women friends. However, negative traits were endorsed as descriptive of women in general. Cognitive stereotypes were endorsed as more descriptive of all women than of the general university student. The tendency to selectively self-stereotype on physical traits was positively associated with appearance, social, and performance self-esteem. The results are discussed for their theoretical and practical implications

An Examination of Relational-interdependent Self-construal, Communal Strength, and Pro-relationship Behaviors in Friendships

Individual differences in relational-interdependent self-construal (RISC) are associated with positive relationship characteristics. This suggests that RISC is positively associated with the degree to which individuals view their relationships as communally-oriented (i.e., governed by norms of responsiveness), which should in turn be associated with increased use of pro-relationship behaviors. Thus, the current study explored the associations between RISC, communal strength, and pro-relationship behaviors in friendships. As predicted, RISC was positively associated with pro-relationship behavior use, but this association was mediated by greater communal strength. This suggests that increased RISC is associated with greater relationship satisfaction because the manner in which individuals view their relationships (i.e., communally) explains the association between RISC and constructive relationship behavior

An Analysis of the 2002 Farm Bill’s Value-Added Producer Grants Program

Our objective is to identify the determinants for success among USDA’s Value- Added Producer Grants (VAPG) program recipients. Business development has become an important program in departments of agricultural economics. Market share was found to be an important determinant of VAPG success. Size variables including greater sales and increased grant dollars, as well as a lower number of producers, were also determinants of business success. Departments of agricultural economics are likely best able to assist VAPG recipients by providing information on price discovery, explaining their relationship to potential plant location, and providing education on best management practices to help producers avoid costly mistakes.agribusiness, business development, value-added, Agribusiness, Financial Economics, Productivity Analysis,

Why Do Leaders Matter? The Role of Expert Knowledge

Why do some leaders succeed while others fail? This question is important, but its complexity makes it hard to study systematically. We examine an industry in which there are well-defined objectives, small teams, and exact measures of leaders’ characteristics. We show that a strong predictor of a leader’s success in year T is that person’s own level of attainment, in the underlying activity, in approximately year T-20. Our data come from 15,000 professional basketball games. The effect on team performance of the coach’s ‘expert knowledge’ is large and is discernible in the data within 12 months of his being hired.organizational performance, firms, leadership, fixed-effects, productivity