Estudio AB-Initio de las propiedades estructurales y electrónicas de la doble Perovskita Ba2InTaO6

Los materiales de tipo Perovskita doble con fórmula genérica A2BB’O6 han sido ampliamente estudiados en los últimos años debido a su gran versatilidad, la cual permite la inclusión de iones de tipo alcalino térreo en los sitios A de la estructura y metales de transición en los sitios B y B’, dando origen a diversas propiedades físicas que redundan en múltiples aplicaciones industriales. En este trabajo estudiamos las propiedades estructurales y electrónicas del compuesto Ba2InTaO6, el cual es de particular interés ya que dichos sistemas podrían aplicarse en el desarrollo de resonadores dieléctricos y filtros para señal de microondas en teléfonos móviles y otros dispositivos inalámbricos, entre otras. Mediante modelamiento computacional ab-initio, basado en la Teoría de Funcional Densidad (DFT), y partiendo de la estructura de grupo espacial Fm-3m, evaluamos los parámetros de red, las energías de equilibrio y la ecuación de estado entre otras cantidades. La minimización de la energía en función del volumen permite la obtención de un parámetro de red de 15.861 Bohr. Los resultados de la Densidad de Estados Electrónicos (DOS) muestran que la doble Perovskita Ba2InTaO6 tiene un gap indirecto de ~ 4.25 eV.Palabras clave: Doble Perovskita, AB-Initio, estructura electrónica.Abstract The double Perovskites materials with the formula A2 BB’O6 has been studied thoroughly in the past years due to its versatility, which allow to include the alkaline earth ions in A sites and transition metals in B and B’sites, giving origin to several physical properties with various industrials applications. In this work the structural and electronic properties of Ba2 InTaO6 are studied, material that is particularly interesting due to its possible application to the development of dielectric resonators and microwave signal filters on mobile phones and other wireless devices. Using ab-initio computational model, based on the Density Funtional Theory (DFT), and starting from spacial group Fm-3m, we calculate lattice parameters, equilibrium energies and equations of state among other quantities. The energy minimization as a function of volume allows to obtain a attice constant of 15.861 Bohr. The results of electronic density of states (DOS) show that the double Perovskite Ba2 InTaO6 has an indirect gap of ~ 4.25 eV.Keywords: Double Perovskites, Ba2 InTaO6 , DFT, Electronic structur

Estrategias de implementación de la gestión del conocimiento en la cooperativa Cadefihuila, en el proceso de selección de personal

Tablas, gráficasLa propuesta de investigación se realizó en la empresa Cadefihuila, de tamaño mediano del sector cooperativo, se encuentra ubicada en el municipio de Pitalito (Huila), y se dedica a compra y venta de café. Actualmente está presentando alta rotación en el personal que afecta la normal ejecución de actividades diarias, generando demoras y represamientos en los servicios que se prestan, lo cual es percibido por el cliente afectando la imagen de la institución. Es por eso que queremos diseñar un modelo de Gestión del Conocimiento dentro del proceso de selección del personal de Cadefihuila, con el propósito de disminuir los índices de rotación de personal de la empresa que están afectando la productividad y competitividad.The proposed research was conducted at the company Cadefihuila of medium-size cooperative sector, is located in the town of Pitalito (Huila), and is dedicated to buying and selling coffee. It is currently presenting high turnover in personnel affect the normal execution daily activities, resulting in delays and damming services provided, which is perceived by the customer affecting the image of the institution. Is why we want to design a model of knowledge management within the selection process Cadefihuila staff, in order to reduce the rates of turnover of the company that are affecting productivity and competitiveness

Familial hypercholesterolaemia in children and adolescents from 48 countries: a cross-sectional study

Background: Approximately 450 000 children are born with familial hypercholesterolaemia worldwide every year, yet only 2·1% of adults with familial hypercholesterolaemia were diagnosed before age 18 years via current diagnostic approaches, which are derived from observations in adults. We aimed to characterise children and adolescents with heterozygous familial hypercholesterolaemia (HeFH) and understand current approaches to the identification and management of familial hypercholesterolaemia to inform future public health strategies. Methods: For this cross-sectional study, we assessed children and adolescents younger than 18 years with a clinical or genetic diagnosis of HeFH at the time of entry into the Familial Hypercholesterolaemia Studies Collaboration (FHSC) registry between Oct 1, 2015, and Jan 31, 2021. Data in the registry were collected from 55 regional or national registries in 48 countries. Diagnoses relying on self-reported history of familial hypercholesterolaemia and suspected secondary hypercholesterolaemia were excluded from the registry; people with untreated LDL cholesterol (LDL-C) of at least 13·0 mmol/L were excluded from this study. Data were assessed overall and by WHO region, World Bank country income status, age, diagnostic criteria, and index-case status. The main outcome of this study was to assess current identification and management of children and adolescents with familial hypercholesterolaemia. Findings: Of 63 093 individuals in the FHSC registry, 11 848 (18·8%) were children or adolescents younger than 18 years with HeFH and were included in this study; 5756 (50·2%) of 11 476 included individuals were female and 5720 (49·8%) were male. Sex data were missing for 372 (3·1%) of 11 848 individuals. Median age at registry entry was 9·6 years (IQR 5·8-13·2). 10 099 (89·9%) of 11 235 included individuals had a final genetically confirmed diagnosis of familial hypercholesterolaemia and 1136 (10·1%) had a clinical diagnosis. Genetically confirmed diagnosis data or clinical diagnosis data were missing for 613 (5·2%) of 11 848 individuals. Genetic diagnosis was more common in children and adolescents from high-income countries (9427 [92·4%] of 10 202) than in children and adolescents from non-high-income countries (199 [48·0%] of 415). 3414 (31·6%) of 10 804 children or adolescents were index cases. Familial-hypercholesterolaemia-related physical signs, cardiovascular risk factors, and cardiovascular disease were uncommon, but were more common in non-high-income countries. 7557 (72·4%) of 10 428 included children or adolescents were not taking lipid-lowering medication (LLM) and had a median LDL-C of 5·00 mmol/L (IQR 4·05-6·08). Compared with genetic diagnosis, the use of unadapted clinical criteria intended for use in adults and reliant on more extreme phenotypes could result in 50-75% of children and adolescents with familial hypercholesterolaemia not being identified. Interpretation: Clinical characteristics observed in adults with familial hypercholesterolaemia are uncommon in children and adolescents with familial hypercholesterolaemia, hence detection in this age group relies on measurement of LDL-C and genetic confirmation. Where genetic testing is unavailable, increased availability and use of LDL-C measurements in the first few years of life could help reduce the current gap between prevalence and detection, enabling increased use of combination LLM to reach recommended LDL-C targets early in life

Review of gender, socioeconomic status, and ethnic background considerations reported in active school travel intervention studies

Introduction: Trends over the last half century have shown that fewer children today are engaging in active modes of travel to and from school than in previous generations. Interventions promoting active school travel (AST) can be effective at reversing these trends and increasing rates of AST among children. This paper aims to explore (1) how studies of AST interventions have considered or framed multiple equity factors, namely those related to gender, socioeconomic status (SES), and ethnic background, in the design and evaluation of AST interventions, and (2) to what extent studies of AST interventions report these equity considerations in their analyses, outcomes, programming, and discussions. Methods: Six databases were used (BIOSIS Previews, GeoBase, PubMed, SCOPUS, SPORTDiscus, and Web of Science) to obtain AST literature published between 2010 and 2019 from around the world. The inclusion criteria applied in this review included a focus on an AST intervention for children (aged 5–19 years), quantitative results, and a primary outcome related to AST. A total of 69 papers were included in the review. Results: Across AST intervention studies, equity considerations were scarcely reported. Among the explicit mentions, gender and socioeconomic status were reported most often compared to ethnic background. Some papers reported differential effects among groups. Gender, SES, and ethnic background were, when reported, generally considered as variables that were controlled for within study samples. Conclusions: Suggestions to address equity within studies of AST interventions include reporting equity considerations made throughout the intervention and its evaluation in the published article. Using and reporting equity frameworks to develop AST interventions and conducting sub-group analyses during evaluation allows for greater assessment of equity effects and improved utility and applicability of the AST intervention. Ensuring the integration of equity into AST literature is needed to support evidence-based and equitable practices

Elementos del mecanismo de concentracion de CO2 en Chlorella vulgaris y Chlamydomonas reinhardii Su papel funcional y regulacion

Centro de Informacion y Documentacion Cientifica (CINDOC). C/Joaquin Costa, 22. 28002 Madrid. SPAIN / CINDOC - Centro de Informaciòn y Documentaciòn CientìficaSIGLEESSpai

Unité, réélaboration des sources et composition d’un réceptaire du Haut Moyen Âge

État de la question Après que Mancini eut fait la description du manuscrit de Lucca (Biblioteca Statale, 296), plusieurs catalogues de bibliothèques firent référence à la présence de deux textes consécutifs dans quelques codex, le premier, d’anthropothérapie, le second, de zoothérapie, présentés systématiquement sous le nom de Curae ex hominibus et Curae ex animalibus. Mais, plus que de véritables titres, ces désignations constituent de simples descriptions de contenu, commodes et fonctionnel..

The editor’s necessary judgement: a critical point at the Liber medicinae ex animalibus by Sextus Placitus Papiriensis (med. 17.1)

En una receta de Sexto Plácito Papiriense para problemas oculares una familia de manuscritos omite un fragmento que sí figura en otra familia, mucho más numerosa. En apariencia se trata de un salto de igual a igual (asperitudinem sedat … asperitudinem sedat). Sin embargo, el léxico vulgar del fragmento omitido y el desarrollo sintáctico de la receta conducen a una conclusión diferente. Es un interpolador el que, al introducir dos frases breves en un lugar crítico, provoca la repetición de la misma expresión distorsionando así la interpretación de los hechos. En consecuencia, es la familia que omite el fragmento la que da el texto que ha salido de manos del autor.In a medical recipe of Sextus Placitus Papyriensis for eye problems, a family of manuscripts omits a fragment that does appear in another much more larger family. At first instance, it looks like a saut du même au même (asperitudinem sedat ... asperitudinem sedat). However, the vulgar vocabulary of the omitted fragment and the syntactic development of the recipe lead to a different conclusion. It is actually an interpolator who, by inserting two short sentences in a critical place, causes the repetition of the same expression, thus distorting the interpretation of the facts. Therefore, it is the family that omits the fragment the one that gives the author’s text

Characterization in silico of flavonoids biosynthesis in Theobroma cacao L.

A detailed and curated map of molecular interactions taking place in the polyphenols (flavonoids) biosynthesis in Theobroma cacao L. is presented. The map was created using the software Cytoscape v.2.7 and the KEGG (Kyoto Encyclopedia of Genes and Genomes) database. The statistical parameters of the network were determined with CentiScape v.1.1 and MetaAnalyzer v.2.6.1. A preliminary theoretical map containing 1024 chemical species and 1099 chemical reactions was built, then a second map that was curated and annotated with the biological facts obtained from approximately 85 publications in T. cacao, with 653 chemical species and 706 chemical reactions. Structural analysis of this interaction network revealed similitude with other biological networks. The study of complex networks opens the way for creating realistic computational models of flavonoid biosynthesis metabolic pathways in cacao