Anomalous size-dependence of interfacial profiles between coexisting phases of polymer mixtures in thin film geometry: A Monte-Carlo simulation

The interfacial profile between coexisting phases of a binary mixture (A,B) in a thin film of thickness D and lateral linear dimensions L depends sensitively on both linear dimensions and on the nature of boundary conditions and statistical ensembles applied. These phenomena generic for systems in confined geometry are demonstrated by Monte-Carlo simulations of the bond fluctuation model of symmetric polymer mixtures. Both the canonical and semi-grand-canonical ensemble are studied. In the canonical ensemble, the interfacial width w increases (from small values which are of the same order as the intrinsic profile) like sqrt{D}, before a crossover to a saturation value w_max (w_max^2 proportional to ln L) sets in. In the semi-grand-canonical ensemble, however, one finds the same widths (w proportional to sqrt{D}) as in the canonical ensemble for not too large L, while for large L the interfacial profile is smeared out over a finite fraction of the film thickness (w proportional to D for D -> infinity). We discuss the implications of these findings for the interpretation of both simulations and experiments.Comment: 42 pages, including 15 PS figures, to appear in JC

An Algorithm for Dynamic Load Balancing of Synchronous Monte Carlo Simulations on Multiprocessor Systems

We describe an algorithm for dynamic load balancing of geometrically parallelized synchronous Monte Carlo simulations of physical models. This algorithm is designed for a (heterogeneous) multiprocessor system of the MIMD type with distributed memory. The algorithm is based on a dynamic partitioning of the domain of the algorithm, taking into account the actual processor resources of the various processors of the multiprocessor system.Comment: 12 pages, uuencoded figures included, 75.93.0

Volunteering, happiness and public policy

Is the activity of volunteering something that benefits the volunteer as well as the recipient of the volunteer's activities? We analyze this relationship and apply matching estimators to the large-scale British Household Panel Survey (BHPS) data set to estimate the causal impact of volunteering on happiness. We take into account personality traits that could jointly determine volunteering behaviour and happiness. We find that the causal impact of volunteering on happiness is positive and increasing over time if volunteering is sustained. In a quantile analysis, we find that this effect seems to be driven by reducing the unhappiness of the less happy quantiles of the well-being distribution. We test the robustness of our findings and discuss their relevance for public policy

Volunteering, happiness and public policy

Is the activity of volunteering something that benefits the volunteer as well as the recipient of the volunteer's activities? We analyze this relationship and apply matching estimators to the large- scale British Household Panel Survey (BHPS) data set to estimate the causal impact of volunteering on happiness. We take into account personality traits that could jointly determine volunteering behaviour and happiness. We find that the causal impact of volunteering on happiness is positive and increasing over time if volunteering is sustained. In a quantile analysis, we find that this effect seems to be driven by reducing the unhappiness of the less happy quantiles of the well-being distribution. We test the robustness of our findings and discuss their relevance for public policy

Reverend John P. Bertolucci to Give Two Lecture at the University of Dayton

News release announces that Reverend John P. Bertolucci will give two lectures during a Charismatic Workshop at the University of Dayton

Analysis of the Lotus japonicus nuclear pore NUP107-160 subcomplex reveals pronounced structural plasticity and functional redundancy

Mutations in the Lotus japonicus nucleoporin genes, NUP85, NUP133, and NENA (SEH1),lead to defects in plant-microbe symbiotic signaling. The homologous proteins in yeast and vertebrates are part of the conserved NUP84/NUP107-160 subcomplex, which is an essential component of the nuclear pore scaffold and has a pivotal role in nuclear pore complex (NPC) assembly. Loss and down-regulation of NUP84/NUP107-160 members has previously been correlated with a variety of growth and molecular defects, however, in L. japonicus only surprisingly specific phenotypes have been reported. We investigated whether Lotus nup85, nup133, and nena mutants exhibit general defects in NPC composition and distribution. Whole mount immunolocalization confirmed a typical nucleoporin-like localization for NUP133, which was unchanged in the nup85-1 mutant. Severe NPC clustering and aberrations in the nuclear envelope have been reported for Saccharomyces cerevisiae nup85 and nup133 mutants. However, upon transmission electron microscopy analysis of L. japonicus nup85, nup133 and nena, we detected only a slight reduction in the average distances between neighboring NPCs in nup133. Using quantitative immunodetection on protein-blots we observed that loss of individual nucleoporins affected the protein levels of other NUP107-160 complex members. Unlike the single mutants, nup85/nup133 double mutants exhibited severe temperature dependent growth and developmental defects, suggesting that the loss of more than one NUP107-160 member affects basal functions of the NPC