Nonequilibrium dynamics of quantum fields

The nonequilibrium effective equation of motion for a scalar background field in a thermal bath is studied numerically. This equation emerges from a microscopic quantum field theory derivation and it is suitable to a Langevin simulation on the lattice. Results for both the symmetric and broken phases are presented.Comment: To appear in the proceedings of 5th International Conference on Perspectives in Hadronic Physics: International Conference on Particle-Nucleus and Nucleus-Nucleus Scattering at Relativistic Energies, Trieste, Italy, 22-26 May 2006. V2:reference correcte

Perfil clínico dos membros da Associação dos Celíacos do Brasil - Regional de Santa Catarina

Trabalho de Conclusão de Curso - Universidade Federal de Santa Catarina. Curso de Medicina. Departamento de Pediatria

Palabras preliminares

Introducción al volumen y homenaje a Mariateresa Cattane

Modeling of amorphous carbon structures with arbitrary structural constraints

In this paper we describe a method to generate amorphous structures with arbitrary structural constraints. This method employs the Simulated Annealing algorithm to minimize a simple yet carefully tailored Cost Function (CF). The Cost Function is composed of two parts: a simple harmonic approximation for the energy-related terms and a cost that penalizes configurations that do not have atoms in the desired coordinations. Using this approach, we generated a set of amorphous carbon structures spawning nearly all the possible combinations of $sp$, $sp^2$ and $sp^3$ hybridizations. The bulk moduli of this set of amorphous carbons structures was calculated using Brenner's potential. The bulk modulus strongly depends on the mean coordination, following a power law behavior with an exponent $\nu=1.51 \pm 0.17$. A modified Cost Function that segregates carbon with different hybridizations is also presented, and another set of structures was generated. With this new set of amorphous materials, the correlation between the bulk modulus and the mean coordination weakens. This method proposed can be easily modified to explore the effects on physical properties of the presence hydrogen, dangling bonds, and structural features such as carbon rings.Comment: 20 pages, 5 figures; v2: minor text modifications, included analysis of angular width; v3: grammar revision, recalculation of the bulk modulu

Applications and Limitations of Inflammatory Biomarkers for Studies on Neurocognitive Impairment in HIV Infection

Despite reduced prevalence of severe forms of HIV-associated neurocognitive disorders (HAND) on current antiretroviral therapy (ART) regimens, milder forms of neurocognitive impairment (NCI) remain prevalent in HIV-infected populations. These mild forms of HAND consist of subtypes, probably reflecting distinct, though possibly overlapping, pathophysiological mechanisms. Factors associated with HAND in HIV patients with prolonged viral suppression on ART include older age, low nadir CD4, active HCV co-infection, and cardiovascular risk factors, but underlying mechanisms and their relationship to innate immune activation, chronic inflammation, and other features of systemic disease are poorly understood. In this article, we discuss applications and limitations of plasma inflammatory biomarkers for studies on HAND in HIV patients on ART and describe an analysis pipeline to reduce common sources of noise and increase likelihood of identifying relevant inflammatory biomarkers. Clinical covariates and comorbidities that influence inflammatory biomarkers, such as aging, obesity, metabolic abnormalities, HCV co-infection, and substance abuse, are also reviewed. As an example for using this analytic pipeline, we present an exploratory study of 22 plasma inflammatory biomarkers (IFN-α 2b and -γ, 16 cytokines/chemokines, sIL-2R, sCD14, HA, and YKL-40) in a cohort of HIV-infected individuals with advanced disease, frequent HCV co-infection, and viral suppression on ART. The identification of inflammatory biomarkers associated with HAND in HIV+ patients on ART may be useful to distinguish between HAND subtypes with distinct pathophysiology, and is important for achieving a systems-level understanding of the biology of these disorders, developing effective therapies, and evaluating therapeutic outcomes. Electronic supplementary material The online version of this article (doi:10.1007/s11481-013-9512-2) contains supplementary material, which is available to authorized users

Análise De Dois Programas De Simulação Para O Ensino Do Empreendedorismo

O papel dos empreendedores e do empreendedorismo no desenvolvimento econômico têm sido estudado no mundo inteiro. Entretanto, o ensino da administração, por muitos anos, foi centrado na gerência da grande empresa. Somente nos últimos 15 anos houve aumento mais significativo na demanda por cursos e formas diferenciadas de ensino na área de empreendedorismo. Assim, entre as maneiras de ensinar e de fornecer maiores experiências empreendedoras conta-se com programas de simulação por computador, os quais ensinam os princípios de como se maximizar as chances de sucesso no empreendedorismo, e também a simulação da dinâmica do ambiente de negócios da empresa de pequeno porte. Entre os existentes, descrevem-se o FastTrac, projetado para ajudar os empresários a melhorar/criar habilidades, administrar e/ou cultivar negócios prósperos, vivenciando o mundo dos negócios, e o Netpreneur, que simula as fases iniciais da criação do negócio na economia em linha, modelando a simulação eletrônica do ambiente do comércio, voltado para o ambiente acadêmico. As principais características de cada um destes programas podem ser resumidas como segue: vivenciam a realidade das empresas, fazendo com que o usuário tome decisões e corram riscos calculados, utilizando dinheiro virtual, ou seja, não perde dinheiro real quando toma uma decisão inapropriada numa situação de instabilidade, insegurança ou mudança. Facilitam o aprendizado por meio da experimentação, ou seja, simulam situações reais de ambigüidade e instabilidade, onde o usuário precisa buscar conhecimentos (financeiros, mercadológicos, administrativos..) necessários para a tomada de decisões e para poder traçar estratégias eficazes para solucionar os problemas que surgem ao longo do trajeto. Os participantes obtêm a prática e a experiência sem os riscos das conseqüências. Estas atividades são virtuais, porém devem ser criadas, desenvolvidas, interpretadas de acordo com o participante. Os empreendedores desenvolvem suas próprias maneiras de tratar as oportunidades, criando novos serviços, produtos, organizações, e maneiras de satisfazer seus clientes ou de realizar negócios

Cerebrospinal fluid metabolomics reveals altered waste clearance and accelerated aging in HIV patients with neurocognitive impairment

Objective(s): HIV-associated neurocognitive disorders (HAND) remain prevalent in HIV-infected patients on antiretroviral therapy (ART), but the underlying mechanisms are unclear. Some features of HAND resemble those of age-associated cognitive decline in the absence of HIV, suggesting that overlapping mechanisms may contribute to neurocognitive impairment. Design: Cross-sectional analysis of cerebrospinal fluid (CSF) from 100 individuals (46 HIV-positive patients and 54 HIV-negative controls). Methods: Untargeted CSF metabolite profiling was performed using liquid/gas chromatography followed by mass spectrometry. Cytokine profiling was performed by Bioplex. Bioinformatic analyses were performed in Metaboanalyst and R. Results: Alterations in the CSF metabolome of HIV patients on ART mapped to pathways associated with neurotransmitter production, mitochondrial function, oxidative stress, and metabolic waste. Many CSF metabolites altered in HIV overlapped with those altered with advanced age in HIV-negative controls, suggesting a pattern indicative of accelerated aging. Machine learning models identified neurotransmitters (glutamate, N-acetylaspartate), markers of glial activation (myo-inositol), and ketone bodies (beta-hydroxybutyric acid, 1,2-propanediol) as top-ranked classifiers of HAND. These CSF metabolites correlated with worse neurocognitive test scores, plasma inflammatory biomarkers [interferon (IFN)-α, IFN-γ, interleukin (IL)-8, IL-1β, IL-6, IL-2Ra], and intrathecal IFN responses (IFN-γ and kynurenine : tryptophan ratio), suggesting inter-relationships between systemic and intrathecal inflammation and metabolic alterations in CSF. Conclusions: Alterations in the CSF metabolome of HIV patients on ART suggest that persistent inflammation, glial responses, glutamate neurotoxicity, and altered brain waste disposal systems contribute to mechanisms involved in HAND that may be augmented with aging

Contrasting multi-taxa diversity patterns between abandoned and non-intensively managed forests in the southern Dolomites

The abandonment of silvicultural activities can lead to changes in species richness and composition of biological communities, when compared to those found in managed forests. The aim of this study was to compare the multi-taxonomical diversity of two mature silver fir-beech-spruce forests in the southern Dolomites (Italy), corresponding to the European Union habitat type 9130. The two sites share similar ecological and structural characteristics, but differ in their recent management histories. In the last 50 years, one site underwent non-intensive management, while the other was left unmanaged and was included in a forest reserve. The species richness and composition of eight taxa were surveyed in the two sites between 2009 and 2011. The difference in mean species richness between the two forest management types was tested through permutation tests, while differences in species composition were tested by principal coordinates analysis and the permutational multivariate analysis of variance. Mean species richness of soil macrofungi, deadwood lichens, bark beetles, and longhorn beetles were significantly higher in the abandoned than in the non-intensively managed forests. Deadwood fungi and epiphytic lichens did not differ in mean species richness between the two study sites, while mean species richness of ground beetles and birds were higher in the non-intensively managed than in the abandoned forest. Significant differences in species composition between the two sites were found for all the taxa, except for longhorn beetles. These results indicate that improving forest landscape heterogeneity through the creation of a mosaic of abandoned and extensively managed forests should better fulfill the requirements of ecologically different taxa