Analysis of correlation and ionization from pair distributions in many-electron systems

This work was supported in part by the Spanish MINECO project FIS2014-59311-P (cofinanced by FEDER). A.L.M., J.C.A. and J.A. belong to the Andalusian research group FQM-020, and S.L.R. to FQM-239.Jensen–Shannon divergence is used to quantify the discrepancy between the Hartree–Fock pair density and the product of its marginals for different N-electron systems, enclosing neutral atoms (with nuclear charge Z = N) and singly-charged ions (N = Z ±1). This divergence measure is applied to determine the interelectronic correlation in atomic systems. A thorough study was carried out, by considering (i) both position and momentum conjugated spaces, and (ii) systems with a nuclear charge as far as Z = 103. The correlation among electrons was measured by comparing, for an arbitrary system, the double-variable electron-pair density with the product of the respective one-particle densities. A detailed analysis throughout the Periodic Table highlights the relevance not only of weightiness for the systems considered, but also of their shell structure. Besides, comparative computations between two-electron densities of different atomic systems (neutrals, cations, anions) quantify their dissimilarities, patently governed by shell-filling patterns throughout the Periodic Table.Spanish MINECO (FEDER) FIS2014-59311-

Adaptación cultural al español del instrumento de evaluación de funcionalidad física en Unidad de Paciente Crítico: “The Chelsea Critical Care Physical Assessment Tool (CPAx)”

Las Unidades de Cuidados Intensivos (UCI), presentan una sobrevida cada vez mayor de los pacientes que ingresan a ellas, donde se ven enfrentados a una nueva entidad fisiopatológica llamada Debilidad Muscular Adquirida en UCI (DAUCI). Algunos test desarrollados para la evaluación de función motriz, que permiten objetivar la progresión del paciente, son la escala de fuerza muscular del Medical Research Council (MRC), el Functional status score for the intensive care unit (FSS-ICU) y el “Chelsea Critical Care Physical Assessment Tool (CPAx). La ventaja del CPAx radica en que este test incluye mayor información asociada al funcionamiento humano como recomienda la OMS, incorporando tanto el componente ventilatorio (que también se ve deteriorado por DAUCI) como neuromuscular lo que permite al profesional kinesiólogo tener una herramienta objetiva más completa del nivel funcional del paciente. Para que sea confiable, todo test debe ser validado en el país donde quiere aplicarse, pero antes de esto debe ser adaptado culturalmente. El objetivo de este trabajo fue efectuar la adaptación transcultural (AT) al español del test de funcionalidad física de aplicación kinésica CPAx. Se utilizó el proceso establecido por Beaton y cols que incluye la formación de un comité de expertos multidisciplinario que da una visión integral a la adaptación y una prueba piloto en que kinesiólogos de UCI sin capacitación previa del test lo lean, posteriormente lo apliquen y entreguen sus observaciones. Conclusiones: Realizar la AT permite dimensionar la importancia que tiene cada una de las etapas de este proceso. El test es el mismo, equivalente al original, pero contiene nuestras características culturales y condiciones técnicas, que lo hace ser comprensible y aplicable en nuestro país. Esta adaptación transcultural también es útil a nivel latinoamericano; para los países de habla hispana que quieran validarlo tenerlo adaptado al español, hace el proceso menos complejo. Palabras clave: Evaluación funcional, Unidad de cuidados intensivos, CPAx, adaptación transcultural

One simulation to have them all: performance of the Bias Assignment Method against N-body simulations

In this paper, we demonstrate that the information encoded in one single (sufficiently large) N-body simulation can be used to reproduce arbitrary numbers of halo catalogues, using approximated realizations of dark matter density fields with different initial conditions. To this end, we use as a reference one realization (from an ensemble of 300) of the Minerva N-body simulations and the recently published Bias Assignment Method to extract the local and non-local bias linking the halo to the dark matter distribution. We use an approximate (and fast) gravity solver to generate 300 dark matter density fields from the down-sampled initial conditions of the reference simulation and sample each of these fields using the halo-bias and a kernel, both calibrated from the arbitrarily chosen realization of the reference simulation. We show that the power spectrum, its variance, and the three-point statistics are reproduced within ∼2 per cent (up to k∼1.0hMpc−1⁠), ∼5−10 per cent⁠, and ∼10 per cent⁠, respectively. Using a model for the real space power spectrum (with three free bias parameters), we show that the covariance matrices obtained from our procedure lead to parameter uncertainties that are compatible within ∼10 per cent with respect to those derived from the reference covariance matrix, and motivate approaches that can help to reduce these differences to ∼1 per cent⁠. Our method has the potential to learn from one simulation with moderate volumes and high-mass resolution and extrapolate the information of the bias and the kernel to larger volumes, making it ideal for the construction of mock catalogues for present and forthcoming observational campaigns such as Euclid or DESI

Exploring the Associative Determinants of Tolerance to the Effects of Cannabis on Locomotion

Experimental evaluation of cannabis tolerance has to date lacked an associative approximation, focusing primarily on physiological variables. The present study assessed acute effects, chronic tolerance, and contextual specificity, exploring a potential associative component underlying cannabis tolerance. Sixteen adult Sprague-Dawley rats of both sexes were assigned to two groups, one receiving vaporized administrations of cannabis and the other receiving the vehicle substance, in two different (counterbalanced) contexts. An initial measurement was performed to assess acute effects, followed by four measurements to evaluate the development of chronic tolerance, and a final measurement to test the context specificity of tolerance, comparing the responses to the usual administration context and a novel context. Ten behaviors were analyzed in an open field. Acute effects were observed in seven indicators, corresponding to greater locomotor activity in the group that received the drug compared to the control group. In five of these, the data also showed the development of chronic tolerance to the effects of cannabis on locomotion, which was indicated by a progressive decrease in locomotor activity in the drug group. However, no evidence of context specificity was found in any of the variables in which chronic tolerance was observed. We discuss factors that may be related to the lack of contextual specificity of cannabis tolerance. Together, our findings show that a single administration of cannabis induces acute effects, and its consecutive consumption develops chronic tolerance to these effects, reaching a hypolocomotor state