A New Mechanism of Sodium Zirconate Formation

The objective of this study was to synthesize sodium zirconate (Na2ZrO3) from the thermal decomposition of two reactants; sodium acetate (CH3COONa) and Zirconium(IV) acetylacetonate (Zr(C5H7O2)4). The Na2ZrO3 formation mechanism has not been previously reported as it is shown in this work. Also, the reagents are soluble in ethanol; making it possible to apply the mechanism proposed in a spray pyrolysis process. The solid-state reaction was derived from the thermal decomposition of its precursors through the thermogravimetric analysis techniques (TG). The desired product formation was proven by means of an x-ray diffraction technique while the gaseous by-products of the reaction were analyzed using of the IR spectroscopy method (FTIR). Solid-state reaction has three significant weight losses and the TG technique displays these behaviors. The kinetic reaction study was completed using the determination of the activation energy, the pre-exponential factor and the reaction order of such regions. Finally, it was numerically proven that the chemical reaction behavior is well reproduced using the Arrhenius-type kinetic model. Keywords: Sodium zirconate, Arrhenius equation, solid-state reaction, thermal decomposition

A dark energy multiverse

We present cosmic solutions corresponding to universes filled with dark and phantom energy, all having a negative cosmological constant. All such solutions contain infinite singularities, successively and equally distributed along time, which can be either big bang/crunchs or big rips singularities. Classicaly these solutions can be regarded as associated with multiverse scenarios, being those corresponding to phantom energy that may describe the current accelerating universe

Modeling of energy efficiency for residential buildings using artificial neuronal networks

The energy efficiency dataset used to support the findings of this study has been deposited in the GitHub repository https://github.com/mereshow/ann-energy-efficiency.git.[Abstract] Increasing the energy efficiency of buildings is a strategic objective in the European Union, and it is the main reason why numerous studies have been carried out to evaluate and reduce energy consumption in the residential sector. The process of evaluation and qualification of the energy efficiency in existing buildings should contain an analysis of the thermal behavior of the building envelope. To determine this thermal behavior and its representative parameters, we usually have to use destructive auscultation techniques in order to determine the composition of the different layers of the envelope. In this work, we present a nondestructive, fast, and cheap technique based on artificial neural network (ANN) models that predict the energy performance of a house, given some of its characteristics. The models were created using a dataset of buildings of different typologies and uses, located in the northern area of Spain. In this dataset, the models are able to predict the U-opaque value of a building with a correlation coefficient of 0.967 with the real U-opaque measured value for the same building

Permanencia y deserción versus autoeficacia de estudiantes universitarios: Un desafío de la calidad educativa

Introduction. the student dropout at university level continues being a current problem that unleashes financial loss besides social and familiar ones, when academic formation goals are not achieved, which assures skillful workers for the current labor world. Objective. To analyze the permanence and dropout versus self-sufficiency of university students in the quality educative framework. Materials and methods. Population was composed by university students in the city of Barranquilla, Colombia. The registry of 2015-1 term, a sample of 322 students, from which 195 were active and 127 on dropout was taken. The work was descriptive and transactional of non-experimental design. Data collection instrument was the General Self-sufficiency scale (GSS), supported by the institutional information system of the Admissions and Registration Department. Results. It was proved that there is not a significant correlation between self-efficiency and permanence, as neither between self-sufficiency or dropout; however, a significant finding was to prove that the average of dropout's self-sufficient students resulted greater than the one of students staying in the institution. Conclusions. It was obtained that there is not a significant correlation among self-efficiency, dropout, and permanence variables.Introducción. La deserción estudiantil a nivel universitario sigue siendo un problema vigente que desencadena pérdidas financieras además de tipo social y familiar, cuando no se alcanzan las metas de la formación académica que garantice trabajadores competentes para el mundo laboral actual. Objetivo. Analizar la permanencia y deserción versus la autoeficacia de estudiantes universitarios en el marco de la calidad educativa. Materiales y métodos. La población estuvo constituida por los estudiantes de una universidad de la ciudad de Barranquilla en Colombia. Se tomó, del registro para el período 2015- 1, una muestra de 322 estudiantes, de los cuales 195 estaban activos y 127 en deserción. El trabajo fue descriptivo y transaccional de diseño no experimental. El instrumento de recolección de datos fue la Escala de Autoeficacia General (EAG), apoyada por el sistema de información institucional del Departamento de Admisiones y Registro. Resultados. Se demostró que no existe una correlación significativa entre autoeficacia y permanencia, así como tampoco entre la autoeficacia y la deserción. Sin embargo, un hallazgo significativo fue demostrar que la media de autoeficacia en desertores resultó mayor que la de los estudiantes que permanecieron en la institución. Conclusiones. Se obtuvo que no se presenta una correlación significativa entre las variables autoeficacia, deserción y permanencia.Introdução. A deserção estudantil a nível universitário segue sendo um problema vigente que desencadeia perdas financeiras ademais de tipo social e familiar, quando não se alcançam as metas da formação acadêmica que garante trabalhadores competentes para o mundo laboral atual. Objetivo. Analisar a permanência e deserção versus a auto eficácia de estudantes universitários no marco da qualidade educativa. Materiais e métodos. A população foi constituída pelos estudantes de uma universidade da cidade de Barranquilla na Colômbia. Se tomou, do registro para o período 2015-1, uma amostra de 322 estudantes, dos quais 195 estavam ativos e 127 em deserção. O trabalho foi descritivo e transacional de desenho não experimental. O instrumento de recolhimento dos dados foi a Escala de Auto eficácia General (EAG), apoiada pelo sistema de informação institucional do Departamento de Admissões e Registro. Resultados. Se demostrou que não existe uma correlação significativa entre auto eficácia e permanência, assim como tampouco entre a auto eficácia e a deserção. Embora, um descobrimento significativo foi demostrar que a média de auto eficácia em desertores resultou maior que a dos estudantes que permaneceram na instituição. Conclusões. Se obteve que não se apresenta una correlação significativa entre as variáveis auto eficácia, deserção e permanência

Permanencia y deserción versus autoeficacia de estudiantes universitarios: Un desafío de la calidad educativa

Introducción. La deserción estudiantil a nivel universitario sigue siendo un problema vigente que desencadena pérdidas financieras además de tipo social y familiar, cuando no se alcanzan las metas de la formación académica que garantice trabajadores competentes para el mundo laboral actual. Objetivo. Analizar la permanencia y deserción versus la autoeficacia de estudiantes universitarios en el marco de la calidad educativa. Materiales y métodos. La población estuvo constituida por los estudiantes de una universidad de la ciudad de Barranquilla en Colombia. Se tomó, del registro para el período 2015- 1, una muestra de 322 estudiantes, de los cuales 195 estaban activos y 127 en deserción. El trabajo fue descriptivo y transaccional de diseño no experimental. El instrumento de recolección de datos fue la Escala de Autoeficacia General (EAG), apoyada por el sistema de información institucional del Departamento de Admisiones y Registro. Resultados. Se demostró que no existe una correlación significativa entre autoeficacia y permanencia, así como tampoco entre la autoeficacia y la deserción. Sin embargo, un hallazgo significativo fue demostrar que la media de autoeficacia en desertores resultó mayor que la de los estudiantes que permanecieron en la institución. Conclusiones. Se obtuvo que no se presenta una correlación significativa entre las variables autoeficacia, deserción y permanencia.Introdução. A deserção estudantil a nível universitário segue sendo um problema vigente que desencadeia perdas financeiras ademais de tipo social e familiar, quando não se alcançam as metas da formação acadêmica que garante trabalhadores competentes para o mundo laboral atual. Objetivo. Analisar a permanência e deserção versus a auto eficácia de estudantes universitários no marco da qualidade educativa. Materiais e métodos. A população foi constituída pelos estudantes de uma universidade da cidade de Barranquilla na Colômbia. Se tomou, do registro para o período 2015-1, uma amostra de 322 estudantes, dos quais 195 estavam ativos e 127 em deserção. O trabalho foi descritivo e transacional de desenho não experimental. O instrumento de recolhimento dos dados foi a Escala de Auto eficácia General (EAG), apoiada pelo sistema de informação institucional do Departamento de Admissões e Registro. Resultados. Se demostrou que não existe uma correlação significativa entre auto eficácia e permanência, assim como tampouco entre a auto eficácia e a deserção. Embora, um descobrimento significativo foi demostrar que a média de auto eficácia em desertores resultou maior que a dos estudantes que permaneceram na instituição. Conclusões. Se obteve que não se apresenta una correlação significativa entre as variáveis auto eficácia, deserção e permanência.Introduction. the student dropout at university level continues being a current problem that unleashes financial loss besides social and familiar ones, when academic formation goals are not achieved, which assures skillful workers for the current labor world. Objective. To analyze the permanence and dropout versus self-sufficiency of university students in the quality educative framework. Materials and methods. Population was composed by university students in the city of Barranquilla, Colombia. The registry of 2015-1 term, a sample of 322 students, from which 195 were active and 127 on dropout was taken. The work was descriptive and transactional of non-experimental design. Data collection instrument was the General Self-sufficiency scale (GSS), supported by the institutional information system of the Admissions and Registration Department. Results. It was proved that there is not a significant correlation between self-efficiency and permanence, as neither between self-sufficiency or dropout; however, a significant finding was to prove that the average of dropout's self-sufficient students resulted greater than the one of students staying in the institution. Conclusions. It was obtained that there is not a significant correlation among self-efficiency, dropout, and permanence variables

A Fungal Effector With Host Nuclear Localization and DNA-Binding Properties Is Required for Maize Anthracnose Development

Plant pathogens have the capacity to manipulate the host immune system through the secretion of effectors. We identified 27 putative effector proteins encoded in the genome of the maize anthracnose pathogen Colletotrichum graminicola that are likely to target the host’s nucleus, as they simultaneously contain sequence signatures for secretion and nuclear localization. We functionally characterized one protein, identified as CgEP1. This protein is synthesized during the early stages of disease development and is necessary for anthracnose development in maize leaves, stems, and roots. Genetic, molecular, and biochemical studies confirmed that this effector targets the host’s nucleus and defines a novel class of double-stranded DNA-binding protein. We show that CgEP1 arose from a gene duplication in an ancestor of a lineage of monocot-infecting Colletotrichum spp. and has undergone an intense evolution process, with evidence for episodes of positive selection. We detected CgEP1 homologs in several species of a grass-infecting lineage of Colletotrichum spp., suggesting that its function may be conserved across a large number of anthracnose pathogens. Our results demonstrate that effectors targeted to the host nucleus may be key elements for disease development and aid in the understanding of the genetic basis of anthracnose development in maize plants.Fil: Vargas, Walter Alberto. Universidad de Salamanca; España. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Sanz Martín, José M.. Universidad de Salamanca; EspañaFil: Rech, Gabriel E.. Universidad de Salamanca; EspañaFil: Armijos Jaramillo, Vinicio D.. Universidad de Salamanca; EspañaFil: Rivera Rodriguez, Lina Patricia. Universidad de Salamanca; EspañaFil: Echeverria, María de Las Mercedes. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; ArgentinaFil: Díaz Mínguez, José M.. Universidad de Salamanca; EspañaFil: Thon, Michael R.. Universidad de Salamanca; EspañaFil: Sukno, Serenella A.. Universidad de Salamanca; Españ

The macrofauna associated to the bamboo coral Isidella elongata: to what extent the impact on isideidae affects diversification of deep-sea fauna

Macrofauna associated with the bamboo coral Isidella elongata was analysed in the Balearic Basin at depths of 697–1308 m. The diversity of associated macrofauna and the specific associations identified depended on different morphological characteristics of colonies, such as height or density of rami. Species associated with Isidella consisted mainly of sessile fauna, such as cnidarians (the actinian Amphianthus dornhii and the solitary coral Desmophyllum dianthus) and cirripeds (Gibossaverruca sp.). The strongest relationship (commensalism) occurred for the Pontogeneiidae amphipod Dautzenbergia megacheir, living attached to colonies of Isidella and represented by all population stages from adult (oostegal) females and males to juveniles. Species-coral relationships between Dautzenbergia and bamboo corals (Isididae) are plausible. Dautzenbergia spp. showed morphological differences between Atlantic (described by Walker 1897 as “eyes wanting”) and Mediterranean (with well-developed reddish eyes) specimens. This would suggest diversification of this genus, as has been recently suggested for Pleustidae associated with deep gorgonians. The diversity of the macrofaunal community associated with I. elongata was higher in the most mature (larger colonies with higher density) fields found NW of Mallorca, with higher colonies than in other parts of the Mediterranean. This was the only site where Gibossaverruca sp. (a first Mediterranean faunal record) and D. dianthus were collected. These complex associations between macrofauna and deep-water corals may provide arguments to protect these fragile ecosystems as a source of faunal diversity and diversification.Versión del editor3,87

Back to the future: restoring historical communities

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Quantum cosmic models and thermodynamics

The current accelerating phase of the evolution of the universe is considered by constructing most economical cosmic models that use just general relativity and some dominating quantum effects associated with the probabilistic description of quantum physics. Two of such models are explicitly analyzed. They are based on the existence of a sub-quantum potential and correspond to a generalization of the spatially flat exponential model of de Sitter space. The thermodynamics of these two cosmic solutions is discussed, using the second principle as a guide to choose which among the two is more feasible. The paper also discusses the relativistic physics on which the models are based, their holographic description, some implications from the classical energy conditions, and an interpretation of dark energy in terms of the entangled energy of the universe.Comment: 15 pages, 1 figure, accepted for publication in Class. Quantum Gra