Fluctuations of entropy production in turbulent thermal convection

We report on a numerical experiment performed to analyze fluctuations of the entropy production in turbulent thermal convection, a physical configuration that represents here a prototypical case of an out-of-equilibrium dissipative system. We estimate the entropy production from instantaneous measurements of the local temperature and velocity fields sampled along the trajectory of a large number of point-wise Lagrangian tracers. The entropy production is characterized by large fluctuations and becomes often negative. This represents a sort of "finite-time" violation of the second principle of thermodynamics, since the direction of the energy flux is opposite to that prescribed by the external gradient. We clearly show that the fluctuations of entropy production observed in the present system verify the fluctuation relation (FR), even though the system is time-irreversible

What is the length of a knot in a polymer?

We give statistical definitions of the length, l, of a loose prime knot tied into a long, fluctuating ring macromolecule. Monte Carlo results for the equilibrium, good solvent regime show that ~ N^t, where N is the ring length and t ~ 0.75 is independent of the knot topology. In the collapsed regime below the theta temperature, length determinations based on the entropic competition of different knots within the same ring show delocalization (t~1).Comment: 9 pages, 5 Postscript figure

A newly discovered Arabic-Hebrew medieval philosophical dictionary, including key-terms of Maimonides' Guide

The manuscript of Turin, Biblioteca Nazionale Universitaria, A. II. 12, includes (on folios 213r-217v) a short Hebrew dictionary of 39 philosophical terms. 23 of these terms can be found in the introduction to part two of Maimonides' Guide of the Perplexed, which has been copied in full lenght in the manuscript as well (according to Samuel Ibn Tibbon's Hebrew translation). The dictionary was probably written in the second half of the 13th century by an anonymous scribe and has been unknown to scholars until now. This article offers a critical edition of the original text of the dictionary, with a facsimile reproduction of the relevant folios as well as an English annotated summary of its content. © 2007 Brill.It comes, it publishes and translates into an anonymous commented version Philosophical Dictionary Hebrew, probably written in the thirteenth century and so far unknown

Medieval Judaic Logic and the Scholastic One in the 14th – 15th Centuries Provence and Italy: a Comparison of the Logical Works by Rav Hezekiah bar Halafta (First Half of the 14th Century) and Rav Judah Messer Leon (Second Half of the 15th Century)

Abstract Hezekiah bar Halafta and Judah Messer Leon, who wrote in 14th – 15th century in Provence and Italy, were the first and last of "Jewish Schoolman." This short article compares two texts, in order to showing differences and similarities

Hippocampal volumes in patients with bipolar-schizophrenic spectrum disorders and their unaffected first-degree relatives

BACKGROUND: schizophrenic and bipolar disorders are complex and disabling psychiatric diseases whose classical nosography and classification are still under challenging debate aiming to overcome the traditional “Kraepelinian Dichotomy”. For the past hundred years most clinical work and research in psychiatry has proceeded under the assumption that schizophrenia and bipolar disorderaredistinctentities with separate underlying disease processes and treatments. In more recent years there has been increasing evidence for phenomenological, biological and genetic overlap between the two disorders (Potash and Bienvenu 2009). Nowadays, the categorical approach to psychiatric nosography is in contrast with the recent neurobiological, neuropsychological and genetic findings in affective and schizophrenic disorders. Further, symptoms and signs constituting bipolar and schizophrenic disorders are continuously, not dichotomously, distributed; there may be no point of “real cleavage” (Phelps et al. 2008). This recognition has led some clinicians and researchers to call for a diagnostic model that, moving to a “dimensional perspective”, formally recognizes a continuous spectrum from schizophrenic to bipolar (and recurrent depressive) disorders. Kelsoe argued that the existing data coming from various fields of research in bipolar and schizophrenic disorders may best fit a model in which different set of genes predispose to overlapping phenotypes in a continuum. Given the apparent overlap of regions of the genome implicated in bipolar disorder with those for schizophrenia (Kelsoe 1999; Berrettini 2000), the data suggest the possibility that a common polygenic background predisposes to both bipolar disorder and schizophrenia, according to the so-called “multiple threshold model” (Kelsoe 2003). As highlighted by Craddock and Owen, the recent findings are compatible with a model of functional psychosis in which susceptibility to a spectrum of clinical phenotypes is under the influence of overlapping sets of genes, which, together with environmental and epigenetic factors, determine an individual’s expression of illness (Craddock and Owen 2005). A lot of interest is focusing on brain structural abnormalities in patients suffering from schizophrenia and bipolar disorder. A huge amount of neuroimaging studies has been published so far, however the literature is heterogeneous and there is still some degree of uncertainty concerning what key regions are involved in the pathogenesis of such disorders. Schizophrenia and Bipolar Disorder have a number of overlapping symptoms and risk factors, but it is not yet clear if the disorders are characterized by similar deviations in brain morphometry or whether any such deviations reflect the impact of shared susceptibility genes on brain structure. To date there is no consensus about whether, and to what extent, gray matter loss in Schizophrenia is mirrored in Bipolar Disorder and what is the effect of medication or other confounding factors. Studies in family members of patients, who share the risk of the disease but not the confounding factors, may help elucidate whether abnormalities in brain structures are shared by both illnesses. AIM OF THE STUDY: to investigate hippocampal gray matter volume differences in a group of patients with bipolar-schizophrenic spectrum disorders, a group of their unaffected first-degree relatives, and a group of healthy control subjects. METHODS: a total of 104 subjects - 36 schizophrenic or schizoaffective (SZ), 27 bipolar (BP), 2 major depression, 8 unaffected relatives (UR), and 31 healthy controls (HC) - underwent 1,5 T MRI scanning, with volumetric T1 3D acquisition protocol, at the Neuroradiology Unit of Conegliano Hospital. We calculate bilateral hippocampal gray matter volume (HV) and total cerebral volume (TCV) in a sample of 31 SZ, 27 BP, 8 UR and 26 HC, with a stereological method using ANALYZE 10.0 software. RESULTS: we found statistically significant reductions in bilateral HV in the BP-SZ patients compared to HC; the direct comparison between patient groups identified statistically significant reduction in the right HV of SZ, but no significant differences for left HV or TCV (however statistical significance was lost after normalization); statistically significant reduction in the left HV and a trend towards statistical significance for right HV in the UR compared to HC (a trend towards statistically significant reduction in bilateral HV persisted after normalization). CONCLUSION: it might be speculated that the alterations of the gray matter volume in the hippocampus highlighted in our study could be interpreted as a possible structural “biological marker” in the schizophrenic-bipolar spectrum

Balanced scorecard adoption: the case of the Milan TA team at BNP Paribas

This Work Project, written in the form of a Direct Research, is to develop a Balanced Scorecard (BSC), specifically designed for the Milan Transfer Agent (TA) Team of BNP Paribas Securities Services (BP2S), located in Warsaw. The goal is not to focus on the whole company, but to identify the main characteristics of the aforementioned team and to develop the BSC that suit it the most, according also to the strategy given by the corporation. As for all the BSC implementations, the purpose is to balance long-term goals, stemming from the corporate strategy and competitive advantage needs, and short-term objectives

Shem Tob ibn Falaquera e la filologia ebraica medievale. A proposito di due libri recenti

The recent publication of two books gives the opportunity of a study about some aspects of the work of Shem Tob ben Yosef ibn Falaquera, a Sephardi philosopher living in the 13th century, as translator of Arabic philosophy and science. They contain editions (accompanied by English translations) of two writings: the ’Iggereṯ ha-Wikuaḥ, edited by S. Harvey, and the section of the Sefer De‛ôṯ ha-Filosofîm devoted to Nicolaus Damascenus' De Plantis, edited by H. J. Drossaart Lulofs. The ecdotic criteria and the textual basis of the two editions are examined, and some corrections and integrations are suggested.La reciente publicación de dos libros ofrece la ocasión de profundizar en algunos aspectos de la función de Shem Tob ben Yosef ibn Falaquera, filósofo sefardí del siglo XIII, como divulgador y traductor de las obras filosóficas y científicas árabes. Se trata de las ediciones (acompañadas de traducción inglesa) del ’Iggereṯ ha-Wikuaḥ, a cargo de S. Harvey, y de la sección del Sefer De‛ôṯ ha-Filosofîm dedicada al De plantis de Nicolás de Damasco, a cargo de H. J. Drossaart Lulofs. Se examinan los criterios editoriales y las bases adoptadas en cada una de las ediciones, y se hacen algunas sugerencias sobre correcciones y adiciones que podrían incorporarse

Os sentidos do fazer teatral para alunos de um curso livre de teatro

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Filosofia e Ciências Humanas, Programa de Pós-Graduação em Psicologia, Florianópolis, 2009.Na atualidade, encontramos muitos trabalhos acadêmicos que dão foco ao fazer teatral, principalmente no que concerne a esta prática enquanto mediadora de processos de aprendizado em diversas áreas. Entretanto, as investigações sobre o processo de produção de sentidos e a constituição dos sujeitos que se envolvem com este fazer, são menos freqüentes. Diante deste quadro, este trabalho tem como objetivo analisar o movimento dos sentidos atribuídos ao fazer teatral, por alunos que buscam esta prática depois de adultos. Para tanto, buscamos investigar a base afetivo-volitiva que leva os alunos a iniciarem um curso básico de teatro e quais os sentidos que, acerca deste fazer artístico, apresentavam antes do início do curso; identificar os sentidos do fazer teatral que são produzidos e modificados durante o curso de teatro e após o freqüentarem; e analisar as implicações deste processo na constituição dos sujeitos observados. O recorte do campo de pesquisa contemplou os momentos que antecederam o início de um curso livre de teatro para adultos na cidade de Curitiba-PR até o término do seu primeiro semestre. Os instrumentos utilizados para produção de informações foram a observação das aulas de teatro e as entrevistas em profundidade realizadas com dois alunos participantes do curso. A análise das entrevistas foi feita desde o referencial teórico da análise do discurso com base nas contribuições do círculo de Bakhtin e da psicológica histórico-cultural de Vygotski, e seus comentadores. As contribuições de outros autores, como Sartre e Sanchez-Vazquez também foram aproveitadas no que concordam com o referencial epistemológico definido para este estudo. Como conclusões, destacamos que, no espaço do curso, os alunos encontraram, na linguagem do teatro, uma nova forma de objetivação da subjetividade, envolveram-se em relações diferenciadas do cotidiano, compartilharam e superaram dificuldades. Deste modo, a experiência do curso afetou intensamente estes alunos, passando a mediar a busca pelos sujeitos que eles desejam ser

Modelado de transiciones de fases en cristales liquidas confinados a 2D

Los cristales líquidos (CL)son materiales que, en su estado líquido, presentan cierto grado de orden molecular. El ordenamiento de CL en dos dimensiones ha sido estudiado teórica y experimentalmente, y se ha encontrado un comportamiento no-universal de la transición nemática-isotrópica, que dependiendo de las características del material y sus interacciones puede ser de primer o segundo orden. Los objetivos de este trabajo son -estudiar teóricamente los diagramas de fases de materiales líquidos adsorbidos en una superficie. -formular un modelo termodinámico basado en la teoría de Onsager que considera interacciones de volumen excluido entre las moléculas, y extender el modelo para considerar interacciones atractivas.Área: Ingeniería, Arquitectura y Tecnologí