203 research outputs found

    Non-minimal Maxwell-Chern-Simons theory and the composite Fermion model

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    The magnetic field redefinition in Jain's composite fermion model for the fractional quantum Hall effect is shown to be effectively described by a mean-field approximation of a model containing a Maxwell-Chern-Simons gauge field non-minimally coupled to matter. Also an explicit non-relativistic limit of the non-minimal (2+1)D Dirac equation is derived.Comment: 10 pages, no figure

    Muertes por accidente de motocicleta y su asociación con variables relacionadas a la reproducción social en un estado del noreste brasileño

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    The objective of this article was to identify the association between motorcycle deaths and variables related to Samaja’s theory of social reproduction in the period 2000-2005 in the state of Pernambuco. An ecological, case-control study was carried out, with municipalities as the unit of analysis. Cases were defined as the 20% of municipalities with the highest local empirical Bayesian coefficients for mortality due to motorcycle accidents, and controls as the 40% with the lowest coefficients. The municipalities with the greatest chances of high coefficients for mortality due to motorcycle accidents showed high population growth factors and increases in the total fleet of motorcycles, with low population densities, low GDP per capita, and more than 20 motorcycles per thousand inhabitants. We conclude that the variables related to macro-policies proved to have greater force in explaining higher chances of motorcycle deathEl objetivo de este artículo es identificar el comportamiento de las muertes por accidentes de motocicleta y las variables relacionadas con la teoría de la reproducción social de Samaja, para el período 2000-2005 en el estado de Pernambuco, Brasil. Se realizó un estudio ecológico con abordaje caso-control. La unidad de análisis fue el municipio. Los casos fueron definidos considerando el 20% de los municipios con los mayores coeficientes bayesianos empíricos locales de mortalidad por accidentes de motocicleta y los controles como el 40% de los municipios con menores coeficientes de mortalidad por accidentes de motocicleta. Los municipios con mayor probabilidad de altos coeficientes de mortalidad por accidentes de motocicleta mostraron factores de crecimiento poblacional altos, así como de crecimiento de la flota de vehículos, bajas densidades demográficas, bajo PBI per cápita, y más de 20 motocicletas por mil habitantes. Se concluye que las variables relacionadas a las macropolíticas mostraron una mayor fuerza para explicar las probabilidades de defunciones por accidentes de motocicleta

    Estudo espacial da mortalidade por acidentes de motocicleta em Pernambuco

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    OBJETIVO: Analizar la distribución espacial de la mortalidad por accidentes de motocicleta en el estado de Pernambuco, Noreste de Brasil. MÉTODOS: Estudio ecológico de base poblacional, usando los datos de mortalidad por accidentes de motocicletas ocurridos de 01/01/2000 a 31/12/2005. Las unidades de análisis fueron municipios. Para el análisis de la distribución espacial de los óbitos fueron construidos coeficientes promedios de mortalidad, teniendo como numerador los óbitos por accidentes de motocicletas registrados en el Sistema de Informaciones sobre Mortalidad, y como denominador, la población del centro del período. Se utilizaron técnicas de análisis espacial, suavización del coeficiente por el método bayesiano empírico local y el diagrama de dispersión de Moran, aplicados sobre la base cartográfica digital del estado. RESULTADOS: El coeficiente promedio de mortalidad por accidentes de motocicletas en Pernambuco fue de 3,47/100 mil habitantes. De los 185 municipios, 16 formaban parte de cinco conglomerados identificados con coeficientes de mortalidad que variaron de 5,66 a 11,66/100 mil habitantes, considerados áreas críticas. Tres de dichas áreas se localizan en la región de desarrollo sertón y dos en la agreste. CONCLUSIONES: El riego de morir por accidente de motocicleta es mayor en las áreas de conglomerado en regiones fuera del eje metropolitano, sugiriendo medidas de intervención que consideren el contexto desarrollo económico, social y cultural.OBJETIVO: Analisar a distribuição espacial da mortalidade por acidentes de motocicleta no estado de Pernambuco. MÉTODOS: Estudo ecológico de base populacional, usando os dados de mortalidade por acidentes de motocicletas ocorridos de 01/01/2000 a 31/12/2005. As unidades de análise foram municípios. Para a análise da distribuição espacial dos óbitos foram construídos coeficientes médios de mortalidade, tendo como numerador os óbitos por acidentes de motocicletas registrados no Sistema de Informações sobre Mortalidade e, como denominador, a população do centro do período. Utilizaram-se técnicas de análise espacial, suavização do coeficiente pelo método bayesiano empírico local e o diagrama de espalhamento de Moran, aplicados sobre a base cartográfica digital do estado. RESULTADOS: O coeficiente médio de mortalidade por acidentes de motocicletas em Pernambuco foi de 3,47/100 mil habitantes. Dos 185 municípios, 16 faziam parte de cinco conglomerados identificados com coeficientes de mortalidade que variaram de 5,66 a 11,66/100 mil habitantes, considerados áreas críticas. Três dessas áreas localizam-se na região de desenvolvimento sertão e duas no agreste. CONCLUSÕES: O risco de morrer por acidente de motocicleta é maior nas áreas de conglomerado em regiões fora do eixo metropolitano, sugerindo medidas de intervenção que considerem o contexto de desenvolvimento econômico, social e cultural.OBJECTIVE: To analyze the spatial distribution of mortality due to motorcycle accidents in the state of Pernambuco, Northeastern Brazil. METHODS: A population-based ecological study using data on mortality in motorcycle accidents from 01/01/2000 to 31/12/2005. The analysis units were the municipalities. For the spatial distribution analysis, an average mortality rate was calculated, using deaths from motorcycle accidents recorded in the Mortality Information System as the numerator, and as the denominator the population of the mid-period. Spatial analysis techniques, mortality smoothing coefficient estimate by the local empirical Bayesian method and Moran scatterplot, applied to the digital cartographic base of Pernambuco were used. RESULTS: The average mortality rate for motorcycle accidents in Pernambuco was 3.47 per 100 thousand inhabitants. Of the 185 municipalities, 16 were part of five clusters identified with average mortality rates ranging from 5.66 to 11.66 per 100 thousand inhabitants, and were considered critical areas. Three clusters are located in the area known as sertão and two in the agreste of the state. CONCLUSIONS: The risk of dying from a motorcycle accident is greater in conglomerate areas outside the metropolitan axis, and intervention measures should consider the economic, social and cultural contexts

    Nature-based tourism elicits a phenotypic shift in the coping abilities of fish

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    Nature-based tourism is gaining extensive popularity, increasing the intensity and frequency of human-wildlife contacts. As a consequence, behavioral and physiological alterations were observed in most exposed animals. However, while the majority of these studies investigated the effects of punctual exposure to tourists, the consequences of constant exposition to humans in the wild remains overlooked. This is an important gap considering the exponential interest for recreational outdoor activities. To infer long-term effects of intensive tourism, we capitalized on Odontostilbe pequira, a short-lived sedentary Tetra fish who spends its life close to humans, on which it feeds on dead skin. Hence, those fish are constantly exposed to tourists throughout their lifecycle. Here we provide an integrated picture of the whole phenomenon by investigating, for the first time, the expression of genes involved in stress response and neurogenesis, as well as behavioral and hormonal responses of animals consistently exposed to tourists. Gene expression of the mineralocorticoid (and cortisol) receptor (mr) and the neurogenic differentiation factor (NeuroD) were significantly higher in fish sampled in the touristic zone compared to those sampled in the control zone. Additionally, after a simulated stress in artificial and controlled conditions, those fish previously exposed to visitors produced more cortisol and presented increased behavioral signs of stress compared to their non-exposed conspecifics. Overall, nature-based tourism appeared to shift selection pressures, favoring a sensitive phenotype that does not thrive under natural conditions. The ecological implications of this change in coping style remain, nevertheless, an open question

    Suppression of costimulation by human cytomegalovirus promotes evasion of cellular immune defenses.

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    CD58 is an adhesion molecule that is known to play a critical role in costimulation of effector cells and is intrinsic to immune synapse structure. Herein, we describe a virally encoded gene that inhibits CD58 surface expression. Human cytomegalovirus (HCMV) UL148 was necessary and sufficient to promote intracellular retention of CD58 during HCMV infection. Blocking studies with antagonistic anti-CD58 mAb and an HCMV UL148 deletion mutant (HCMV∆UL148) with restored CD58 expression demonstrated that the CD2/CD58 axis was essential for the recognition of HCMV-infected targets by CD8+ HCMV-specific cytotoxic T lymphocytes (CTLs). Further, challenge of peripheral blood mononuclear cells ex vivo with HCMV∆UL148 increased both CTL and natural killer (NK) cell degranulation against HCMV-infected cells, including NK-driven antibody-dependent cellular cytotoxicity, showing that UL148 is a modulator of the function of multiple effector cell subsets. Our data stress the effect of HCMV immune evasion functions on shaping the immune response, highlighting the capacity for their potential use in modulating immunity during the development of anti-HCMV vaccines and HCMV-based vaccine vectors

    Diagnostic accuracy of procalcitonin in critically ill immunocompromised patients

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    <p>Abstract</p> <p>Background</p> <p>Recognizing infection is crucial in immunocompromised patients with organ dysfunction. Our objective was to assess the diagnostic accuracy of procalcitonin (PCT) in critically ill immunocompromised patients.</p> <p>Methods</p> <p>This prospective, observational study included patients with suspected sepsis. Patients were classified into one of three diagnostic groups: no infection, bacterial sepsis, and nonbacterial sepsis.</p> <p>Results</p> <p>We included 119 patients with a median age of 54 years (interquartile range [IQR], 42-68 years). The general severity (SAPSII) and organ dysfunction (LOD) scores on day 1 were 45 (35-62.7) and 4 (2-6), respectively, and overall hospital mortality was 32.8%. Causes of immunodepression were hematological disorders (64 patients, 53.8%), HIV infection (31 patients, 26%), and solid cancers (26 patients, 21.8%). Bacterial sepsis was diagnosed in 58 patients and nonbacterial infections in nine patients (7.6%); 52 patients (43.7%) had no infection. PCT concentrations on the first ICU day were higher in the group with bacterial sepsis (4.42 [1.60-22.14] vs. 0.26 [0.09-1.26] ng/ml in patients without bacterial infection, <it>P </it>< 0.0001). PCT concentrations on day 1 that were > 0.5 ng/ml had 100% sensitivity but only 63% specificity for diagnosing bacterial sepsis. The area under the receiver operating characteristic (ROC) curve was 0.851 (0.78-0.92). In multivariate analyses, PCT concentrations > 0.5 ng/ml on day 1 independently predicted bacterial sepsis (odds ratio, 8.6; 95% confidence interval, 2.53-29.3; <it>P </it>= 0.0006). PCT concentrations were not significantly correlated with hospital mortality.</p> <p>Conclusion</p> <p>Despite limited specificity in critically ill immunocompromised patients, PCT concentrations may help to rule out bacterial infection.</p

    In situ short-term responses of Amazonian understory plants to elevated CO<sub>2</sub>

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    The response of plants to increasing atmospheric CO2 depends on the ecological context where the plants are found. Several experiments with elevated CO2 (eCO2) have been done worldwide, but the Amazonian forest understory has been neglected. As the central Amazon is limited by light and phosphorus, understanding how understory responds to eCO2 is important for foreseeing how the forest will function in the future. In the understory of a natural forest in the Central Amazon, we installed four open-top chambers as control replicates and another four under eCO2 (+250 ppm above ambient levels). Under eCO2, we observed increases in carbon assimilation rate (67%), maximum electron transport rate (19%), quantum yield (56%), and water use efficiency (78%). We also detected an increase in leaf area (51%) and stem diameter increment (65%). Central Amazon understory responded positively to eCO2 by increasing their ability to capture and use light and the extra primary productivity was allocated to supporting more leaf and conducting tissues. The increment in leaf area while maintaining transpiration rates suggests that the understory will increase its contribution to evapotranspiration. Therefore, this forest might be less resistant in the future to extreme drought, as no reduction in transpiration rates were detected.</p
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