Analytical pair correlations in ideal quantum gases: Temperature-dependent bunching and antibunching

The fluctuation-dissipation theorem together with the exact density response spectrum for ideal quantum gases has been utilized to yield a new expression for the static structure factor, which we use to derive exact analytical expressions for the temperature{dependent pair distribution function g(r) of the ideal gases. The plots of bosonic and fermionic g(r) display "Bose pile" and "Fermi hole" typically akin to bunching and antibunching as observed experimentally for ultracold atomic gases. The behavior of spin-scaled pair correlation for fermions is almost featureless but bosons show a rich structure including long-range correlations near T_c. The coherent state at T=0 shows no correlation at all, just like single-mode lasers. The depicted decreasing trend in correlation with decrease in temperature for T < T_c should be observable in accurate experiments.Comment: 8 pages, 1 figure, minor revisio

Lexical neighborhood effects in pseudoword spelling

The general aim of this study is to contribute to a better understanding of the cognitive processes that underpin skilled adult spelling. More specifically, it investigates the influence of lexical neighbors on pseudo-word spelling with the goal of providing a more detailed account of the interaction between lexical and sublexical sources of knowledge in spelling. In prior research examining this topic, adult participants typically heard lists composed of both words and pseudo-words and had to make a lexical decision to each stimulus before writing the pseudo-words. However, these priming paradigms are susceptible to strategic influence and may therefore not give a clear picture of the processes normally engaged in spelling unfamiliar words. In our two Experiments involving 71 French-speaking literate adults, only pseudo-words we represented which participants were simply requested to write to dictation using the first spelling that came to mind. Unbeknownst to participants, pseudo-words varied according to whether they did or did not have a phonological word neighbor. Results revealed that low-probability yphoneme/grapheme mapping(e.g.,/o/-> aud in French)were used significantly more often in spelling pseudo-words with a close phonological lexical neighbour with that spelling(e.g.,/krepo/derived from “crapaud,”/krapo/)than in spelling pseudo-words with no close neighbors(e.g.,/frøpo/).In addition, the strength of this lexical influence increased with the lexical frequency of the word neighbors as well as with their degree of phonetic overlap with the pseudoword targets. These results indicate that information from lexical and sublexical processes is integrated in the course of spelling, and a specific theoretical account as to how such integration may occur is introduced

Is there a reentrant glass in binary mixtures?

By employing computer simulations for a model binary mixture, we show that a reentrant glass transition upon adding a second component only occurs if the ratio $\alpha$ of the short-time mobilities between the glass-forming component and the additive is sufficiently small. For $\alpha \approx 1$, there is no reentrant glass, even if the size asymmetry between the two components is large, in accordance with two-component mode coupling theory. For $\alpha \ll 1$, on the other hand, the reentrant glass is observed and reproduced only by an effective one-component mode coupling theory.Comment: 4 pages, 3 figure

Threshold Photoelectron Spectrum of Cyclobutadiene: Comparison with Time-Dependent Wavepacket Simulations

The C4H4 isomer cyclobutadiene (CBD) is the prime model for antiaromaticity and thus a molecule of considerable interest in chemistry. Because it is highly reactive, it can only be studied under isolated conditions. Its electronic structure is characterized by a pseudo-Jahn–Teller effect in the neutral and a E ⊗ β Jahn–Teller effect in the cation. As a result, recording photoelectron spectra as well as describing them theoretically has been challenging. Here we present the photoion mass-selected threshold photoelectron spectrum of cyclobutadiene together with a simulation based on time-dependent wavepacket dynamics that includes vibronic coupling in the ion, taking into account eight vibrational modes in the cation. Excellent agreement between theory and experiment is found, and the ionization energy is revised to 8.06 ± 0.02 eV

Critical Decay at Higher-Order Glass-Transition Singularities

Within the mode-coupling theory for the evolution of structural relaxation in glass-forming systems, it is shown that the correlation functions for density fluctuations for states at A_3- and A_4-glass-transition singularities can be presented as an asymptotic series in increasing inverse powers of the logarithm of the time t: $\phi(t)-f\propto \sum_i g_i(x)$, where $g_n(x)=p_n(\ln x)/x^n$ with p_n denoting some polynomial and x=ln (t/t_0). The results are demonstrated for schematic models describing the system by solely one or two correlators and also for a colloid model with a square-well-interaction potential.Comment: 26 pages, 7 figures, Proceedings of "Structural Arrest Transitions in Colloidal Systems with Short-Range Attractions", Messina, Italy, December 2003 (submitted

Armenia and Belarus: caught between the EU's and Russia's conditionalities?

This article looks into Armenia's and Belarus’ engagement with the European Union's (EU) and Russia's conditionalities, the two EU Eastern Partnership (EaP) countries that are also members of the Russia-led Eurasian Economic Union (EAEU). While paying attention to political, economic (including energy and technical) as well as security dimensions of the EU's and Russia's approaches, as proposed in the present special section, the article demonstrates that the conditionalities extended by the EU and Russia to the two countries in question have differed. In their turn, Armenia and Belarus have reacted differently to Russia's and the EU's conditionalities. Against the backdrop of the changing significance ascribed to both the EU's and Russia's policies towards their common neighbourhood since the 1990s, the present contribution identifies and analyses factors that account for the diverging positions of Armenia and Belarus, including the type of regime, the geopolitical considerations, the stakes in the economic and energy spheres and the predisposition to integration. The article shows that in the resulting complex context, Armenia and Belarus have been able to influence the shape and content of the EU's and Russia's conditionalities, although in a different way and to a different extent.Ministry of Education and Science (UID/CPO/ 00758/2013

Teaching child and adolescent psychiatry to undergraduate medical students - A survey in German-speaking countries

Objective To conduct a survey about teaching child and adolescent psychiatry to undergraduate medical students in German-speaking countries. Methods A questionnaire was sent to the 33 academic departments of child and adolescent psychiatry in Germany, Austria, and the German-speaking part of Switzerland. Results All departments responded. For teaching knowledge, the methods most commonly reported were lectures and case presentations. The most important skills to be taught were thought to be how to assess psychopathology in children and how to assess families. For elective courses, the departments reported using a wide range of teaching methods, many with active involvement of the students. An average of 34 hours per semester is currently allocated by the departments for teaching child and adolescent psychiatry to medical students. Required courses are often taught in cooperation with adult psychiatry and pediatrics. Achievement of educational objectives is usually assessed with written exams or multiple-choice tests. Only a minority of the departments test the achievement of skills. Conclusions Two ways of improving education in child and adolescent psychiatry are the introduction of elective courses for students interested in the field and participation of child and adolescent psychiatrists in required courses and in longitudinal courses so as to reach all students. Cooperation within and across medical schools can enable departments of child and adolescent psychiatry, despite limited resources, to become more visible and this specialty to become more attractive to medical students. Compared to the findings in earlier surveys, this survey indicates a trend towards increased involvement of academic departments of child and adolescent psychiatry in training medical students

Phase diagram of the metal-insulator transition in 2D electronic systems

We investigated the interdependence of the effects of disorder and carrier correlations on the metal-insulator transition in two-dimensional electronic systems. We present a quantitative metal-insulator phase diagram. Depending on the carrier density we find two different types of metal-insulator transition - a continuous localization for rs=<8 and a discontinuous transition at higher rs. The critical level of disorder at the transition decreases with decreasing carrier density. At very low carrier densities we find that the system is always insulating. The value of the conductivity at the transition is consistent with recent experimental measurements. The self-consistent method which we have developed includes the effects of both disorder and correlations on the transition, using a density relaxation theory with the Coulomb correlations determined from numerical simulation data.Comment: 4 pages, RevTeX + epsf, 5 figures. New comments on conducting phase and on the conductivity. References updated and correcte

The genomics of domestication special issue editorial

Domestication has been of major interest to biologists for centuries, whether for creating new plants and animal types or more formally exploring the principles of evolution. Such studies have long used combinations of phenotypic and genetic evidence. Recently, the advent of a large number of genomes and genomic tools across a wide array of domesticated plant and animal species has reinvigorated the study of domestication. These genomic data, which can be easily generated for nearly any species, often provide great insight with or without a reference genome. The comparison of genome wide data from domestic and wild species has ignited a wave of insight into human, plant, and animal history with a new range of questions becoming accessible. With this in mind, this issue of Evolutionary Applications includes eleven papers covering a wide range of perspectives and methodologies relevant to understanding genomic variation under domestication

Spatial-temporal variability of in situ cyanobacteria vertical structure in Western Lake Erie: Implications for remote sensing observations

Remote sensing has provided expanded temporal and spatial range to the study of harmful algal blooms (cyanoHABs) in western Lake Erie, allowing for a greater understanding of bloom dynamics than is possible through in situ sampling. However, satellites are limited in their ability to specifically target cyanobacteria and can only observe the water within the first optical depth. This limits the ability of remote sensing to make conclusions about full water column cyanoHAB biomass if cyanobacteria are vertically stratified. FluoroProbe data were collected at nine stations across western Lake Erie in 2015 and 2016 and analyzed to characterize spatio-temporal variability in cyanobacteria vertical structure. Cyanobacteria were generally homogenously distributed during the growing season except under certain conditions. As water depth increased and high surface layer concentrations were observed, cyanobacteria were found to be more vertically stratified and the assumption of homogeneity was less supported. Cyanobacteria vertical distribution was related to wind speed and wave height, with increased stratification at low wind speeds (bathymetry and environmental conditions could lead to improved biomass estimates. Additionally, cyanobacteria contributions to total chlorophyll-a were shown to change throughout the season and across depth, suggesting the need for remote sensing algorithms to specifically identify cyanobacteria