3,484 research outputs found

    Exact results of a mixed spin-1/2 and spin-S Ising model on a bathroom tile (4-8) lattice: effect of uniaxial single-ion anisotropy

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    Effect of uniaxial single-ion anisotropy upon magnetic properties of a mixed spin-1/2 and spin-S (S>=1) Ising model on a bathroom tile (4-8) lattice is examined within the framework of an exact star-triangle mapping transformation. The particular attention is focused on the phase diagrams established for several values of the quantum spin number S. It is shown that the mixed-spin bathroom tile lattice exhibits very similar phase boundaries as the mixed-spin honeycomb lattice whose critical points are merely slightly enhanced with respect to the former ones. The influence of uniaxial single-ion anisotropy upon the total magnetization vs. temperature dependence is particularly investigated as well.Comment: 12 pages, 4 figure

    Post-Traumatic Stress Disorder and Urban Violence: An Anthropological Study

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    The study aimed to understand how distress is experienced by patients with Post-Traumatic Stress Disorder (PTSD) in the social-cultural context of São Paulo, Brazil, an urban environment marked by social inequality and high levels of violence. A qualitative study was conducted between 2008 and 2010 with PTSD patients (F43.1, ICD-10, 1997) who had been victims of robberies and kidnappings in São Paulo. Dense ethnographic observations were carried out, as well as in-depth semi-structured interviews with ten adult patients. the analysis method used was based on anthropology. the results show that it is particularly important to distinguish between perceptions of different forms of the experience of social suffering and perceptions of health and illness held by victims and biomedical experts. the cause of PTSD is more often associated with the personal problems of the victim than with the specific traumatic event. the distress described in terms of what is considered a normal reaction to violence and what is considered a symptom of PTSD. the findings indicate that the diagnostic of PTSD can be understood in relation to the different contexts within a culture. the ethnographic approach serves not only to illuminate individual suffering but also the social suffering experienced by the residents of São Paulo.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Universidade Federal de São Paulo, BR-04038020 São Paulo, BrazilUniversidade Federal de São Paulo, BR-04038020 São Paulo, BrazilWeb of Scienc

    A comparative study of the dynamic critical behavior of the four-state Potts like models

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    We investigate the short-time critical dynamics of the Baxter-Wu (BW) and n=3n=3 Turban (3TU) models to estimate their global persistence exponent θg\theta _{g}. We conclude that this new dynamical exponent can be useful in detecting differences between the critical behavior of these models which are very difficult to obtain in usual simulations. In addition, we estimate again the dynamical exponents of the four-state Potts (FSP) model in order to compare them with results previously obtained for the BW and 3TU models and to decide between two sets of estimates presented in the current literature. We also revisit the short-time dynamics of the 3TU model in order to check if, as already found for the FSP model, the anomalous dimension of the initial magnetization x0x_{0} could be equal to zero

    Great Salt Lake Halophilic Archaea: A Model for Mineral Entrapment of Life

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    NASA’s Mars Exploration Rover, Opportunity, found veins of gypsum and layer of salt deposited by water in 2011(Figure 7). Gypsum has been detected on Mars as early as 2005 by the ESA’s Mars Express Orbiter, which later found evidence of chloride salts in 2008. On Earth, gypsum is formed in hypersaline environments, in minerals left behind when water evaporates. During evaporation, gypsum deposits and salt crystals can trap microorganisms in fluid inclusions. Gypsum obtained from Great Salt Lake, along with salt crystals collected from the salt glands of pelicans, were used to develop a method to extract halophilic archaea and culture it in the lab. Our studies show that gypsum was difficult to dissolve in aqueous microbiological media. Various methods of dissolution involving mechanical crushing and different solvents including microbiological media were tested. We also employed a variety of cultivation methods. We will present data on best practices for obtaining halophilic microorganisms from gypsum and salt crystal samples. The method obtained could be used to isolate potential microorganisms present in these minerals from Mars

    The drugs misuse related harm reduction in the health promoting schools

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    The goal of this paper is to review the school-based drugs misuse prevention programs, and to establish a connection with the health promotion and health promoting school concepts, in an attempt to create a new proposal. There are several models of preventive intervention, but the results of its evaluations show little improvement. The most hopeful programs imply in giving up the restrict focus of prevention (of a specific disease) to adopt the health promotion concept. The application of the health promotion concept in the school environment resulted in the health promoting school concept, which can be defined as a school that has an organized set of policies, procedures, activities, and structures, designed to protect and promote the health and well-being of all school community members. The harm reduction proposal, as a prevention strategy, come together the health promoting school proposal, and in this way our proposal is a set of health promotion actions that includes: wider and progressive goals; breaking the manichaeism; inclusive actions; community partnerships including many sectors of society; youth autonomy; and the focus on the person in all its complexity, not only on the substance use or misuse. This proposal aims all students, regardless if they had or not already tried or they still are using any psychoactive substance.Este trabalho tem por objetivo revisar os modelos de prevenção do uso indevido de drogas em ambiente escolar, relacionando-os aos conceitos de promoção de saúde e escola promotora de saúde, e propor um modelo de intervenção. Os modelos de intervenção são múltiplos, os resultados provenientes das avaliações de impacto são modestos. As abordagens preventivas mais promissoras ampliam o campo de intervenções para o ambiente físico e social, enfocando a saúde como um todo, aproximando-se do conceito de promoção de saúde. A aplicação deste no âmbito escolar resultou no conceito de escola promotora de saúde. Esta pode ser definida como a escola com políticas, procedimentos, atividades e estrutura que resultem na proteção e promoção à saúde e ao bem-estar de todos os membros da comunidade escolar. A proposta da redução de danos, pensada como estratégia de prevenção, converge para a da escola promotora de saúde, e neste sentido propomos ações de promoção de saúde pautadas por: objetivos amplos e escalonados; ruptura com o maniqueísmo; ações inclusivas; parcerias intersetoriais; incentivo à autonomia dos alunos; abordagem do indivíduo em toda a sua complexidade. Esta proposta amplia a abrangência da intervenção para todos os alunos, independentemente se estes já experimentaram, já fizeram ou fazem algum uso de substâncias psicoativas.Universidade Federal de São Paulo (UNIFESP), Escola Paulista de Medicina (EPM) Departamento de PsiquiatriaUnisantos Departamento de PsiquiatriaUNIFESP, EPM, Depto. de PsiquiatriaSciEL

    Situations related to drug misuse in public schools in the city of São Paulo, Brazil

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    OBJECTIVE: To explore situations, attitudes and behavior of public elementary school education supervisors concerning psychoactive substance misuse. METHODS: The study was carried out in the city of São Paulo, Southeastern Brazil, in 2002. Data were collected using a semi-structured questionnaire applied to eight key informants in the administrative area experienced in education supervision. Qualitative content analysis with ethnographic reference was conducted. RESULTS: Most discourses show that knowledge transmission is thought as essential for drug use prevention, though supervisors reported being ill-informed on this subject. The most frequent attitudes toward drug users are impotence and inability to act and sometimes a repressive attitude. These are motivated by misinformation and fear due to mistaken association of drug users and criminals. In situations indirectly related to drug abuse (family and behavior problems) more understanding and inclusive attitudes are reported, following the harm reduction paradigm. CONCLUSIONS: Theoretical capacity building of educators for preventive attitudes would support their skills developed through dealing with situations (in)directly related to drug abuse in schools. Thus, educators would feel more confident to make interventions for harm or risk reduction among drug users.OBJETIVO: Investigar situações, atitudes e comportamentos dos coordenadores pedagógicos das escolas municipais de ensino fundamental relacionados ao uso indevido de substâncias psicoativas. MÉTODOS: Estudo realizado na cidade de São Paulo, em 2002. As informações foram colhidas por meio de entrevista semi-estruturada, com oito informantes-chave locados em setor administrativo e com experiência de coordenação pedagógica. Foi realizada a análise qualitativa de conteúdo, com o referencial etnográfico. RESULTADOS: A idéia da transmissão de conhecimentos como base da prevenção permeia a maioria dos discursos, entretanto, os coordenadores relataram sentirem-se mal informados. As atitudes mais freqüentes frente ao usuário de drogas são de impotência e paralisia e algumas vezes, repressora. Elas são motivadas pelo desconhecimento e medo devido à associação entre usuário e marginalidade. Nas situações indiretamente associadas ao abuso de drogas (problemas familiares e de comportamento) foram relatadas atitudes mais compreensivas e inclusivas, compatível com práticas do paradigma da redução de danos. CONCLUSÕES: Uma capacitação teórica dos educadores para uma prática preventiva teria a função de ratificar aquela desenvolvida a partir da sua vivência na escola com as situações (in)diretamente associadas ao abuso de drogas. Conseqüentemente, os tornaria mais seguros nas suas intervenções de redução de danos ou risco com os usuários.Universidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Programa de Orientação e Atendimento a DependentesUniversidade Católica de Santos Programa de Mestrado em Saúde ColetivaUNIFESP, EPM, Programa de Orientação e Atendimento a DependentesSciEL

    Correlated edge overlaps in multiplex networks

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    This work was partially supported by the FET proactive IP project MULTIPLEX 317532. G.J.B. was supported by the FCT Grant No. SFRH/BPD/74040/2010

    An alternative order parameter for the 4-state Potts model

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    We have investigated the dynamic critical behavior of the two-dimensional 4-state Potts model using an alternative order parameter first used by Vanderzande [J. Phys. A: Math. Gen. \textbf{20}, L549 (1987)] in the study of the Z(5) model. We have estimated the global persistence exponent θg\theta_g by following the time evolution of the probability P(t)P(t) that the considered order parameter does not change its sign up to time tt. We have also obtained the critical exponents θ\theta, zz, ν\nu, and β\beta using this alternative definition of the order parameter and our results are in complete agreement with available values found in literature.Comment: 6 pages, 6 figure

    The anisotropic Ashkin-Teller model: a renormalization group study

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    The two-dimensional ferromagnetic anisotropic Ashkin-Teller model is investigated through a real-space renormalization-group approach. The critical frontier, separating five distinct phases, recover all the known exacts results for the square lattice. The correlation length (νT)(\nu_T) and crossover (ϕ)(\phi) critical exponents are also calculated. With the only exception of the four-state Potts critical point, the entire phase diagram belongs to the Ising universality class.Comment: 3 ps figures, accepted for publication in Physica
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