Triangle-Well and Ramp Interactions in One-Dimensional Fluids: A Fully Analytic Exact Solution

The exact statistical-mechanical solution for the equilibrium properties, both thermodynamic and structural, of one-dimensional fluids of particles interacting via the triangle-well and the ramp potentials is worked out. In contrast to previous studies, where the radial distribution function $g(r)$ was obtained numerically from the structure factor by Fourier inversion, we provide a fully analytic representation of $g(r)$ up to any desired distance. The solution is employed to perform an extensive study of the equation of state, the excess internal energy per particle, the residual multiparticle entropy, the structure factor, the radial distribution function, and the direct correlation function. In addition, scatter plots of the bridge function versus the indirect correlation function are used to gauge the reliability of the hypernetted-chain, Percus--Yevick, and Martynov--Sarkisov closures. Finally, the Fisher--Widom and Widom lines are obtained in the case of the triangle-well model.Comment: 19 pages, 9 figure

Nitric Oxide Regulates Neurogenesis in the Hippocampus following Seizures

Hippocampal neurogenesis is changed by brain injury. When neuroinflammation accompanies injury, activation of resident microglial cells promotes the release of inflammatory cytokines and reactive oxygen/nitrogen species like nitric oxide (NO). In these conditions, NO promotes proliferation of neural stem cells (NSC) in the hippocampus. However, little is known about the role of NO in the survival and differentiation of newborn cells in the injured dentate gyrus. Here we investigated the role of NO following seizures in the regulation of proliferation, migration, differentiation, and survival of NSC in the hippocampus using the kainic acid (KA) induced seizuremouse model. We show that NO increased the proliferation of NSC and the number of neuroblasts following seizures but was detrimental to the survival of newborn neurons. NO was also required for the maintenance of long-term neuroinflammation. Taken together, our data show that NO positively contributes to the initial stages of neurogenesis following seizures but compromises survival of newborn neurons.Foundation for Science and Technology (FCT, Portugal); COMPETE; FEDER [PTDC/SAU-NEU/102612/2008, PTDC/NEU-OSD/0473/2012, PEst-C/SAU/LA0001/2013-2014, PEst-OE/EQB/LA0023/2013-2014]; FCT, Portugal [SFRH/BPD/78901/2011, SFRH/BD/77903/2011

Equation of state of hard-disk fluids under single-file confinement

The exact transfer-matrix solution for the longitudinal equilibrium properties of the single-file hard-disk fluid is used to study the limiting low- and high-pressure behaviors analytically as functions of the pore width. In the low-pressure regime, the exact third and fourth virial coefficients are obtained, which involve single and double integrals, respectively. Moreover, we show that the standard irreducible diagrams do not provide a complete account of the virial coefficients in confined geometries. The asymptotic equation of state in the high-pressure limit is seen to present a simple pole at the close-packing linear density, as in the hard-rod fluid, but, in contrast to the latter case, the residue is $2$. Since, for an arbitrary pressure, the exact transfer-matrix treatment requires the numerical solution of an eigenvalue integral equation, we propose here two simple approximations to the equation of state, with different complexity levels, and carry out an extensive assessment of their validity and practical convenience vs the exact solution and available computer simulations.Comment: 14 pages, 9 figures, 4 appendices; v3: minor change

Structural properties of hard-disk fluids under single-file confinement

The structural properties of confined single-file hard-disk fluids are studied analytically by means of a mapping of the original system onto a one-dimensional mixture of non-additive hard rods, the mapping being exact in the polydisperse limit. Standard statistical-mechanical results are used as a starting point to derive thermodynamic and structural properties of the one-dimensional mixture, where the condition that all particles have the same chemical potential must be taken into account. Analytical results are then provided for the $n$th neighbor probability distribution function, the radial distribution function, and the structure factor, a very good agreement being observed upon comparison with simulation data from the literature. Moreover, we have analyzed the scaling form for the disappearance of defects in the zigzag configuration for high pressure, and have obtained the translational correlation length and the structural crossover in the oscillation frequency for asymptotically large distances.Comment: 15 pages, 12 figures; v2: new subsections and 4 new figures added; v3: minor change

Detection of outliers in multivariate data: a method based on clustering and robust estimators

Outlier identification is important in many applications of multivariate analysis. Either because there is some specific interest in finding anomalous observations or as a pre-processing task before the application of some multivariate method, in order to preserve the results from possible harmful effects of those observations. It is also of great interest in supervised classification (or discriminant analysis) if, when predicting group membership, one wants to have the possibility of labelling an observation as does not belong to any of the available groups. The identification of outliers in multivariate data is usually based on Mahalanobis distance. The use of robust estimates of the mean and the covariance matrix is advised in order to avoid the masking effect (Rousseeuw and Leroy, 1985; Rousseeuw and von Zomeren, 1990; Rocke and Woodruff, 1996; Becker and Gather, 1999). However, the performance of these rules is still highly dependent of multivariate normality of the bulk of the data. The aim of the method here described is to remove this dependence

Caso Clínico de una Niña con Algoneurodistrofia

A clinical case of a 12-year-old female child with anxiety symptoms and a diagnosis of Algoneurodystrophy in the left hand is presented. The psychological assessment was carried out using the following instruments: observation, psychological interview, Wechsler Intelligence Scale for Children (WISC-III), State/Trait Anxiety Questionnaire for children, and Conners Scales for parents and teachers. The intervention aimed to reduce anxiety levels, promote self-esteem, and alleviate the child's grief. For this purpose, a cognitive-behavioral intervention was carried out with the child and their parents. Through education, the child's parents were alerted to the need to express the feeling of loss, providing an environment for the resolution of the grieving process of all family members. Furthermore, they were also warned about the maintenance factors of the child's anxiety symptoms, such as the issue of high parental demand. As a result, it can be concluded that good therapeutic gains were seen, translating into the resolution of the child's problems and, consequently, increasing their psychological well-being.Se presenta el caso clínico de una niña de 12 años con síntomas de ansiedad y diagnóstico de algoneurodistrofia en la mano izquierda. La evaluación psicológica se realizó mediante los siguientes instrumentos: observación, entrevista psicológica, Escala de Inteligencia Wechsler para Niños (WISC-III), Cuestionario de Ansiedad Estado/Rasgo para niños y Escalas de Conners para padres y profesores. La intervención tuvo como objetivo reducir los niveles de ansiedad, promover la autoestima y aliviar los sentimientos de dolor. Para ello, se realizó una intervención cognitivo-conductual con la niña y los padres.  A través de la educación, los padres de la niña fueron alertados sobre la necesidad de expresar el sentimiento de pérdida, brindando un entorno para la resolución del proceso de duelo de todos los miembros de la familia. Además, también se les advirtió sobre los factores de mantenimiento de los síntomas de ansiedad de la niña, como el tema de la alta demanda de los padres. Como resultado, se puede concluir que se apreciaron buenos avances terapéuticos, que se tradujeron en la resolución de los problemas de la niña y, en consecuencia, en un aumento de su bienestar psicológico

The first notification of Salmonella Budapest in Portuguese meat products: a case report

Salmonella is a bacterium that can cause an illness in humans called salmonellosis. In the European Union, over 100,000 human cases were reported last year. The EFSA has estimated that the overall economic cost of human salmonellosis could be as high as EUR 3 billion a year

Resveratrol affects differently rat liver and brain mitochondrial bioenergetics and oxidative stress in vitro: Investigation of the role of gender

Resveratrol (3,5,40-trihydroxy-trans stilbene) is commonly recognized by its antioxidant properties. Despite its beneficial qualities, the toxic effects of this natural compound are still unknown. Since mitochondria are essential to support the energy-dependent regulation of several cell functions, the objective of this study was to evaluate resveratrol effects on rat brain and liver mitochondrial fractions from male and females regarding oxidative stress and bioenergetics. No basal differences were observed between mitochondrial fractions from males and females, except in liver mitochondria, the generation of H2O2 by the respiratory chain is lower for female preparations. Resveratrol inhibited lipid peroxidation in preparations from both genders and organs. Furthermore, brain mitochondria in both gender groups appeared susceptible to resveratrol as seen by a decrease in state 3 respiration and alterations in mitochondrial membrane potential fluctuations during ADP phosphorylation. As opposed, liver mitochondria were less affected by resveratrol. Our data also demonstrates that resveratrol inhibits complex I activity in all mitochondrial preparations. The results suggest that brain mitochondria appear to be more susceptible to resveratrol effects, and gender appears to play a minor role. It remains to be determined if resveratrol effects on brain mitochondria contribute to deterioration of mitochondrial function or instead to mediate hormesis-mediated events.This work is supported by PTDC/AGR-ALI/108326/2008 to M.S.S. from the Portuguese Foundation for Science and Technology, FEDER/ Compete/National Funds. A.C.M., A.M.S. and V.A.S. are recipient of SFRH/BD/33892/2009, SFRH/BD/76086/2011 and SFRH/BPD/ 31549/2006 fellowships, respectively