Density, structure and dynamics of water: the effect of Van der Waals interactions

It is known that ab initio molecular dynamics (AIMD) simulations of liquid water, based on the generalized gradient approximation (GGA) to density functional theory (DFT), yield structural and diffusive properties in reasonable agreement with experiment only if artificially high temperatures are used in the simulations. The equilibrium density, at normal conditions, of DFT water has been recently shown by Schmidt et al. [J. Phys. chem. B, 113, 11959 (2009)] to be underestimated by different GGA functionals for exchange and correlation, and corrected by the addition of interatomic pair potentials to describe van derWaals (vdW) interactions. In this contribution we present a DFTAIMD study of liquid water using several GGA functionals as well as the van der Waals density functional (vdW-DF) of Dion et al. [Phys. Rev. Lett. 92, 246401(2004)]. As expected, we find that the density of water is grossly underestimated by GGA functionals. When a vdW-DF is used, the density improves drastically and the experimental diffusivity is reproduced without the need of thermal corrections. We analyze the origin of the density differences between all the functionals. We show that the vdW-DF increases the population of non-H-bonded interstitial sites, at distances between the first and second coordination shells. However, it excessively weakens the H-bond network, collapsing the second coordination shell. This structural problem is partially associated to the choice of GGA exchange in the vdW-DF. We show that a different choice for the exchange functional is enough to achieve an overall improvement both in structure and diffusivity.Comment: 11 pages, 9 figures, submitted. Revised versio

La prescripción del ejercicio físico para personas mayores: valores normativos de la condición física

La evaluación de la condición física debe ser considerado como un aspecto a tener en cuenta a la hora de determinar la capacidad funcional de los ancianos. Debido a la no existía de unos valores referenciales, a partir de los cuales determinar el estado físico de los ancianos, y a las posibilidades que esta información nos daría, a la hora de prescribir ejercicio, fue lo que nos condujo a la llevar a cabo este estudio. El estudio etnográfico se llevó a cabo en la Comunidad Autónoma Gallega y en el se testaron a 159 hombres y 692 mujeres, todos mayores de 65 años e inscriptos en programas de actividad física. La muestra realizó voluntariamente las ocho pruebas de que consta la Batería E.C.F.A, mediante la cual se evaluó: 1)Composición corporal, 2)Fuerza máxima de prensión manual, 3)Equilibrio monopodal, 4)Fuerza resistencia abdominal, 5)Flexibilidad anterior del tronco, 6)Fuerza máxima de piernas, 7)Coordinación Oculo-manual (Agilidad manual) y 8)Resistencia Cardio-respiratoria (Caminar 2 Km)

Agua virtual : el agua que no vemos : seguridad alimentaria

Fil: Volpedo, Alejandra V. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias; ArgentinaFil: Pérez Carrera, Alejo. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias; ArgentinaFil: Fernández Cirelli, Alicia. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias; ArgentinaLas actividades agropecuarias son el principal usuario de agua dulce ya que utilizan aproximadamente entre el 70 y el 80% del agua accesible, por lo que producir alimentos implica, necesariamente, consumir agua. En los últimos tiempos, el concepto de agua virtual -en referencia al agua utilizada en la producción de alimentos y/o la contenida en ellos- globaliza discusiones sobre su escasez, la sostenibilidad ecológica, la seguridad alimentaria y el consumo, estimulando la reflexión sobre los procesos de cambio socio-económicos en relación con la evolución de la demanda de alimentos

Direct, automated and sensitive determination of glyphosate and related anionic pesticides in environmental water samples using solid-phase extraction on-line combined with liquid chromatography tandem mass spectrometry

An automated procedure for the simultaneous determination of six anionic pesticides, including glyphosate (GLY) and its transformation product aminomethylphosphonic acid (AMPA), was developed and applied to the analysis of environmental water samples. The proposed method combines on-line concentration of water samples (0.160 mL), with compounds separation in an anion-exchange liquid chromatography (LC) column, followed by their selective determination by tandem mass spectrometry (MS/MS). The global procedure was completed in 25 min, providing limits of quantification (LOQs) between 5 ng L−1 and 20 ng L−1, with reduced effect of the surface water matrix in the efficiency of process (SPE and ionization yields). The method was applied to the analysis of grab samples obtained from three watersheds, in two rural and one residential area, in Galicia (Northwest Spain). Out of six investigated compounds, Fosetyl, AMPA and GLY were noticed in the set of processed samples. Their detection frequencies increased from 12% (Fosetyl) to 88% (AMPA). Median concentrations followed the same trend varying from 9 ng L−1 (Fosetyl) to 44 ng L−1 (AMPA). The higher levels and the large seasonal variations in the residues of the latter species were noticed in small rivers affected by discharges of municipal sewage treatment plants (STPs)This study was supported by Spanish Government and Xunta de Galicia through grants PGC2018–094613-B-I00 and ED431C 2021/06, respectively. Both projects are co-funded by the EU FEDER programS

Explicit oral narrative intervention for students with Williams syndrome

Narrative skills play a crucial role in organizing experience, facilitating social interaction and building academic discourse and literacy. They are at the interface of cognitive, social, and linguistic abilities related to school engagement. Despite their relative strengths in social and grammatical skills, students with Williams syndrome (WS) do not show parallel cognitive and pragmatic performance in narrative generation tasks. The aim of the present study was to assess retelling of a TV cartoon tale and the effect of an individualized explicit instruction of the narrative structure. Participants included eight students with WS who attended different special education levels. Narratives were elicited in two sessions (pre and post intervention), and were transcribed, coded and analyzed using the tools of the CHILDES Project. Narratives were coded for productivity and complexity at the microstructure and macrostructure levels. Microstructure productivity (i.e., length of narratives) included number of utterances, clauses, and tokens. Microstructure complexity included mean length of utterances, lexical diversity and use of discourse markers as cohesive devices. Narrative macrostructure was assessed for textual coherence through the Pragmatic Evaluation Protocol for Speech Corpora (PREP-CORP). Macrostructure productivity and complexity included, respectively, the recall and sequential order of scenarios, episodes, events and characters. A total of four intervention sessions, lasting approximately 20 min, were delivered individually once a week. This brief intervention addressed explicit instruction about the narrative structure and the use of specific discourse markers to improve cohesion of story retellings. Intervention strategies included verbal scaffolding and modeling, conversational context for retelling the story and visual support with pictures printed from the cartoon. Results showed significant changes in WS students’ retelling of the story, both at macro- and microstructure levels, when assessed following a 2-week interval. Outcomes were better in microstructure than in macrostructure, where sequential order (i.e., complexity) did not show significant improvement. These findings are consistent with previous research supporting the use of explicit oral narrative intervention with participants who are at risk of school failure due to communication impairments. Discussion focuses on how assessment and explicit instruction of narrative skills might contribute to effective intervention programs enhancing school engagement in WS students

Semantically enabling UPnP Networks of Multimedia Home Content

There is plenty of multimedia content available in our homes, stored in multimedia disk drives, personal computers, or digital cameras. Protocols like Universal Plug and Play (UPnP) allow sharing this content among storage devices and displaying them in multimedia renderers in the local area networks of our homes. However, UPnP does not provide native support for the exchange of resources across homes neither does it provide means to describe multimedia content so as to facilitate search across multimedia resources. In this paper we describe a set of extensions to the UPnP protocol to provide a uniform access to multimedia content belonging to different homes, as well as mechanisms to create tag-based and ontology-based metadata, allowing search and Linked-Data publishing of these multimedia resources

Identificación de regiones genómicas de almendro en progenies de híbridos interespecíficos (abstract)

La mejora genética de portainjertos tiene por objetivo obtener diferentes híbridos interespecíficos y combinar la tolerancia a estreses abióticos. Distintos cruzamientos entre almendro, melocotonero y ciruelo se están estudiado para su adaptación a un amplio rango de condiciones edafoclimáticas. En este estudio analizamos 49 individuos de cuatro progenies de híbridos interespccíficos de tres especies y sus parentales (dos ciruelos mirobolanes: 'P.2175' y 'P.2980'; los híbridos almendro x melocotonero 'Garnem' y 'Felinem'; el almendro 'Garfi'; y el melocotonero 'Nemared'). Se analizaron 48 SSRs polimórficos en los parentales a lo largo de los 8 grupos de ligamiento a partir de varios mapas de referencia de Prunus. El dendrograma UPGMA generado con la variabilidad genética observada, clasificó los genotipos en 5 grupos, permitiéndonos diferenciar en nuestras progenies las regiones genómicas del almendro entre las regiones del melocotonero y el ciruelo. En estas regiones se va a llevar a cabo el estudio de distintos genes implicados en la tolerancia a la sequía, puesto que el almendro es más tolerante que las otras dos especies, melocotonero y cirueloPublishe

Identification of almond genomic regions in four 3-way interspecific hybrid progenies (abstract)

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Spike-based VITE control with Dynamic Vision Sensor applied to an Arm Robot.

Spike-based motor control is very important in the field of robotics and also for the neuromorphic engineering community to bridge the gap between sensing / processing devices and motor control without losing the spike philosophy that enhances speed response and reduces power consumption. This paper shows an accurate neuro-inspired spike-based system composed of a DVS retina, a visual processing system that detects and tracks objects, and a SVITE motor control, where everything follows the spike-based philosophy. The control system is a spike version of the neuroinspired open loop VITE control algorithm implemented in a couple of FPGA boards: the first one runs the algorithm and the second one drives the motors with spikes. The robotic platform is a low cost arm with four degrees of freedom.Ministerio de Ciencia e Innovación TEC2009-10639-C04-02/01Ministerio de Economía y Competitividad TEC2012-37868-C04-02/0