A Micro-Macro Parareal Implementation for the Ocean-Circulation Model FESOM2

A micro-macro variant of the parallel-in-time algorithm Parareal has been applied to the ocean-circulation and sea-ice model model FESOM2. The state-of-the-art software in climate research has been developed by the Alfred-Wegener-Institut (AWI) in Bremen, Germany. The algorithm requires two meshes of low and high spatial resolution to define the coarse and fine propagator. As a first assessment we refined the PI mesh, increasing its resolution by factor 4. The main objective of this study was to demonstrate that micro-macro Parareal can provide convergence in diagnostic variables in complex climate research problems. After the introduction to FESOM2 we show how to generate the refined mesh and which interpolation methods were chosen. With the convergence results presented we discuss the success of this attempt and which steps have to be taken to extend the approach to current research problems.Comment: 65 pages, 107 figure

Small Volume Resuscitation in Hemorrhagic Shock: Historical and Scientific Background

Exsanguination is the primary cause of death in trauma. The mortality can be prevented if bleeding can be stopped and blood loss can be replaced with fluid. Fluid resuscitation has been proven to improve tissue perfusion and reverse the cellular injury and swelling in state of hemorrhage. Fluid resuscitation can also depress the cytokines that could lead to multiple organ failure in hemorrhagic shock. The method of fluid resuscitation widely used nowadays refers to guideline by American College of Surgeon. Despite its wide application, some studies reported the guideline may be harmful and addressed the lack of its scientific basis. These studies introduced another strategy called small volume fluid resuscitation. Although studies were limited to animal model and some small clinical trials, they showed promising result for small volume fluid resuscitation. Small volume fluid resuscitation could reduce the additional blood loss due to continued bleeding or re-bleeding and lower mortality rate. Small volume fluid is an appropriate option in resuscitating patients especially those with uncontrolled hemorrhage

Quantitative NME microscopy of iron transport in methanogenic aggregates

Transport of micronutrients (iron, cobalt, nickel, etc.) within biofilms matrixes such as methanogenic granules is of high importance, because these are either essential or toxic for the microorganisms living inside the biofilm. The present study demonstrates quantitative measurements of metal transport inside these biofilms using T1 weighted 3D RARE. It is shown that iron(II)-EDTA diffusion within the granule is independent of direction or the inner structure of the granules. Assuming position dependence of the spin-lattice relaxivity, Fick’s law for diffusion in a sphere can be applied to simulate the diffusion within the methanogenic granules under investigation. A relatively low diffusion coefficient of 2.5*10-11 m2·s-1 was obtained for iron diffusion within the methanogenic granul

Microscopic Origin of the Valley Hall Effect in Transition Metal Dichalcogenides Revealed by Wavelength Dependent Mapping

The band structure of many semiconducting monolayer transition metal dichalcogenides (TMDs) possesses two degenerate valleys, with equal and opposite Berry curvature. It has been predicted that, when illuminated with circularly polarized light, interband transitions generate an unbalanced non-equilibrium population of electrons and holes in these valleys, resulting in a finite Hall voltage at zero magnetic field when a current flows through the system. This is the so-called valley Hall effect that has recently been observed experimentally. Here, we show that this effect is mediated by photo-generated neutral excitons and charged trions, and not by inter-band transitions generating independent electrons and holes. We further demonstrate an experimental strategy, based on wavelength dependent spatial mapping of the Hall voltage, which allows the exciton and trion contributions to the valley Hall effect to be discriminated in the measurement. These results represent a significant step forward in our understanding of the microscopic origin of photo-induced valley Hall effect in semiconducting transition metal dichalcogenides, and demonstrate experimentally that composite quasi-particles, such as trions, can also possess a finite Berry curvature.Comment: accepted for publication in Nano Letter

Psychometric properties of the Disordered Eating Attitude Scale for adult men

OBJECTIVE: To evaluate psychometric properties of the Disordered Eating Attitude Scale (DEAS) for men. METHODS: Two hundred and twenty-eight undergraduate male students (18-39 years old) answered the DEAS, originally developed and validated for women. Internal consistency was evaluated by Cronbach's Alpha; convergent validity by comparing DEAS and the Eating Attitude (EAT) and Restraint Scale (RS) scores using Pearson's coefficient. Test-retest reliability was evaluated with a subsample (n = 38) in a month interval by means of intraclass correlation coefficient (ICC). Known-groups validity was obtained comparing scores in DEAS among undergraduate students and men with eating disorders (ED) (n = 28). RESULTS: Internal consistency of scale was 0.63. DEAS score correlated with EAT (r = 0.65) and RS (r = 0.51); ICC between test and retest was 0.948. Known-groups analysis differentiated ED patients and undergraduate students (p < 0.001). CONCLUSIONS: The scale presented adequate psychometric properties and could be used in studies with adult men, since the construct is not explored among males. Nevertheless, it is recommended to revise the scale and to develop specific instruments for male public.OBJETIVO: Avaliar as propriedades psicométricas da Escala de Atitudes Alimentares Transtornadas (EAAT) para o sexo masculino. MÉTODOS: Duzentos e vinte e oito universitários (18-39 anos) responderam à EAAT, originalmente desenvolvida e validada para o sexo feminino. A consistência interna foi avaliada pelo Alpha de Cronbach e a validade convergente, por meio do coeficiente de correlação de Pearson comparando os escores da EAAT, do Teste de Atitudes Alimentares (EAT) e da Escala de Restrição (RS). A reprodutibilidade foi avaliada aplicando a escala numa subamostra (n = 38) com um mês de intervalo utilizando o coeficiente de correlação intraclasse (CCI). A validade known-groups foi obtida comparando o escore dos universitários na EAAT com o escore de homens com diagnóstico de transtornos alimentares (TA) (n = 28). RESULTADOS: A consistência interna da escala foi de 0,63. O escore da EAAT foi correlacionado com a EAT (r = 0,65) e RS (r = 0,51), e o CCI entre o teste e o reteste foi de 0,948. A análise known-groups diferenciou pacientes com TA de estudantes universitários (p < 0,001). CONCLUSÕES: A escala apresentou propriedades psicométricas adequadas e pode ser utilizada em estudos com homens adultos - uma vez que o constructo é pouco explorado em homens. Recomenda-se, de qualquer forma, uma revisão da escala e desenvolvimento de instrumentos específicos para o público masculino.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Universidade de São Paulo Faculdade de Saúde Pública Departamento de NutriçãoUniversidade Federal de Juiz de Fora Programa de Pós-Graduação em PsicologiaUniversidade Federal de São Paulo (UNIFESP) Departamento de Saúde, Clínica e InstituiçõesUNIFESP, Depto. de Saúde, Clínica e InstituiçõesSciEL

Dynamics, cation conformation and rotamers in guanidinium ionic liquids with ether groups

Ionic liquids are modern materials with a broad range of applications, including electrochemical devices, the exploitation of sustainable resources and chemical processing. Expanding the chemical space to include novel ion classes allows for the elucidation of novel structure-property relationships and fine tuning for specific applications. We prepared a set of ionic liquids based on the sparsely investigated pentamethyl guanidinium cation with a 2-ethoxy-ethyl side chain in combination with a series of frequently used anions. The resulting properties are compared to a cation with a pentyl side chain lacking ether functionalization. We measured the thermal transitions and transport properties to estimate the performance and trends of this cation class. The samples with imide-type anions form liquids at ambient temperature, and show good transport properties, comparable to imidazolium or ammonium ionic liquids. Despite the dynamics being significantly accelerated, ether functionalization of the cation favors the formation of crystalline solids. Single crystal structure analysis, ab initio calculations and variable temperature nuclear magnetic resonance measurements (VT-NMR) revealed that cation conformations for the ether- and alkyl-chain-substituted are different in both the solid and liquid states. While ether containing cations adopt compact, curled structures, those with pentyl side chains are linear. The Eyring plot revealed that the curled conformation is accompanied by a higher activation energy for rotation around the carbon-nitrogen bonds, due to the coordination of the ether chain as observed by VT-NMR