Thermisches Verhalten von CuOn-Polyedern in ausgewählten Verbindungen: Wechselspiel zwischen lokaler Strukturverzerrung und Kristalltopologie

An Hand des thermischen Verhaltens von CuOn-Polyedern wird ein Einblick in das gegenseitige Wechselspiel von lokaler Polyederverzerrung und Kristalltopologie gegeben. Die Polyederverzerrungen in den untersuchten Verbindungen beruhen auf dem Jahn-Teller-Effekt. Cu-O-Tetraeder werden abgeflacht, Cu-O-Oktaeder gestreckt. Je nach Strukturtyp teilt sich die lokale Polyederverzerrung auch makroskopisch dem Gesamtkristall mit und führt zu einer Erniedrigung der Gesamtsymmetrie (Spinell, Pyroxen), beziehungsweise bleibt nur lokal wirksam (Akermanit). Der Jahn-Teller-Efekt und damit die Verzerrung der jeweiligen Struktur kann durch thermische Behandlung aufgehoben werden. Die Phasenumwandlungen werden detailiert röntgenographisch und thermoanalytisch beschrieben

THE NON-STOICHIOMETRIC PEROVSKITE BAPBO3-x: CRYSTAL STRUCTURE AND CATION - ANION DISTRIBUTION

The ABO3 perovskites reveal a large structural tolerance for enabling a variety of substitutions at both A and B sites and for a wide range of cation and vacancy ordering. This led to a number of discoveries of useful chemical and physical properties. In particular the oxygen deficit influences the electrical conductivity of ABO3 perovskites. The degree of oxygen deficiency is influenced by sample preparation, calcination temperature and atmosphere used for synthesizing and annealing. However, oxygen measurements are challenging and the references give either none or incorrect data. Finally, conclusions described in literature about the structure of BaPbO3 are contradicting with respect to the oxygen content. Describing the structure, the most suggested space groups in references for BaPbO3-x are either the monoclinic space group I2/m [1-3] or the orthorhombic space group Imma [4, 5]. Imma as well as I112/m show tilted PbO6 octahedra around the [100] - and [010] - axis of the cubic aristotype. Although the tilt angle for Imma equals for a- and b-axis, it is different in I112/m. If differences between tilt angles are small a structural classification is rather difficult. Please click Additional Files below to see the full abstract

Non-equilibrium antigen recognition in acute infections

The immune response to an acute primary infection is a coupled process of antigen proliferation, molecular recognition by naive B-cells, and their subsequent proliferation and antibody shedding. Here we show B-cells can efficiently recognise new antigens by a tuned kinetic proofreading mechanism, where the number of proofreading steps and the characteristic rate of each step are set by the complexity of the immune repertoire. This process produces potent, specific and fast recognition of antigens, maintaining a spectrum of genetically distinct B-cell lineages as input for affinity maturation. We show that the proliferation-recognition dynamics of a primary infection can me mapped onto a generalised Luria-Delbr\"uck process, akin to the dynamics of the classic fluctuation experiment. We derive the resulting statistics of the activated immune repertoire: antigen binding affinity, expected size, and frequency of active B-cell clones are related by power laws. Their exponents depend on the antigen and B-cell proliferation rate, the number of proofreading steps, and the lineage density of the naive repertoire. Empirical data of mouse immune repertoires are found to be consistent with activation involving at least three proofreading steps. Our model predicts key clinical characteristics of acute infections. The primary immune response to a given antigen is strongly heterogeneous across individuals; few elite responders are distinguished by early activation of high-affinity clones. Conversely, ageing of the immune system, by reducing the density of naive clones, degrades potency and speed of pathogen recognition

Workload balancing in distributed virtual reality environments

Virtual Reality (VR) has grown to become state-of-theart technology in many business- and consumer oriented E-Commerce applications. One of the major design challenges of VR environments is the placement of the rendering process. The rendering process converts the abstract description of a scene as contained in an object database to an image. This process is usually done at the client side like in VRML [1] a technology that requires the client’s computational power for smooth rendering. The vision of VR is also strongly connected to the issue of Quality of Service (QoS) as the perceived realism is subject to an interactive frame rate ranging from 10 to 30 frames-per-second (fps), real-time feedback mechanisms and realistic image quality. These requirements overwhelm traditional home computers or even high sophisticated graphical workstations over their limits. Our work therefore introduces an approach for a distributed rendering architecture that gracefully balances the workload between the client and a clusterbased server. We believe that a distributed rendering approach as described in this paper has three major benefits: It reduces the clients workload, it decreases the network traffic and it allows to re-use already rendered scenes

CLIMA ORGANIZACIONAL Y DESEMPEÑO LABORAL DE LOS TRABAJADORES DEL GOBIERNO REGIONAL DE JUNÍN, 2021

La presente investigación tuvo como objetivo general determinar la relación que existe entre el clima organizacional y desempeño laboral de los trabajadores del Gobierno Regional de Junín, 2021. La metodología corresponde al enfoque de investigación cuantitativa, con un nivel de investigación descriptivo - correlacional, el diseño utilizado fue no experimental y de corte transversal. La muestra de estudio estuvo conformada por 231 trabajadores del Gobierno Regional de Junín. Para recolectar datos y medir las variables e indicadores se utilizó la técnica de la encuesta con su instrumento el cuestionario. Los resultados muestran que la mayoría de los trabajadores del Gobierno Regional de Junín consideran que el nivel de clima organizacional es regular al 64.5% y el desempeño laboral en nivel medio al 88.3%. Para probar la hipótesis se realizó la correlación del Rho de Spearman, la cual muestra un resultado de 0.490, lo cual concluye que existe una relación significativa entre el clima organizacional y el desempeño laboral de los trabajadores del Gobierno Regional de Junín, 2021.Tesi

Child labor and school desertion in Perú by 2015

La investigación tuvo como objetivo analizar el trabajo infantil y la deserción escolar con base en informaciones del Instituto Nacional de Estadísticas e Informática Perú 2015. Se trató de un estudio retrospectivo descriptivo-correlacional, con datos obtenidos de la página del Instituto Nacional de Estadísticas e Informática (INEI), la muestra estuvo conformada por niños entre 5 a 9 años de edad, haciendo un total 717 encuestados, los datos descriptivos fueron analizados en el programa estadístico SPSS versión 24, y para las asociaciones se utilizó el programa EViews y se utilizó la prueba de Máxima Verosimilitud del modelo Probit Bivariado con un p ≤ 0,05. Los resultados mostraron que los niños que realizaron actividades laborales fueron un 54,4 % (257) de sexo masculino y el 47,6 % (233) de sexo femenino, así la mayoría 84,5 % (414) pertenecían al área rural y el 15,5 % (76) área urbana, la mayoría residían 58,2 % (285) residían en la región Sierra, en cuanto a la deserción escolar del total de niños el 95 % (681) refirió que estudia con regularidad a la escuela, mientras que el 5 % (36) dejó de asistir, se encontró una relación directa entre el trabajo infantil y la deserción escolar, con un coeficiente de correlación (0,2315), entre la asistencia al colegio y el hecho de trabajar con una probabilidad de ocurrencia del 20,42 %. Se concluye que el trabajo infantil es predominante en área rural y residentes de la región sierra, así también existe asociación estadística entre el trabajo infantil y la deserción escolar.The research has the objective to analyze child labor and school dropout base don information from the National Institute of Statistics and Informatics Perú 2015. It was a retrospective descriptive correlational study, wth data obtained from the National Institute of Statistics and Informatics (INEI), the sample consisted of children between 5 to 9 years of age, making a total of 717 surveyeds , the descriptive data were analyzed in the statistical program SPSS versión 24, and for associations the EViews program was used and the Maxium Likelihood test of the Maxium Likelihood test of the Bivariate Probit model with a p ≤ 0,05 was used. The results showed that the children who carried out work activities were 54,4 % (257) of male sex and 47,6 % (233) of female sex, the majority 84.5% (414) belonged to the rural área and 15,5 % (76) urban área, most reside 58,2% (285) resided in the Sierra región, in ítems of school dropout of the total number of children 95 % (681) reported that they regularly study the school, while 5% (36) stopped attending, a direct relationship was found between child labor and school dropout, with a correlation coefficient (0,2315), between attending school and working with a probability of ocurrence of 20,42 %. It is concluded that child labor is predominant in rural áreas and residents of the mountain región, so there is also a statistical association between child labor and school dropout

Sourdough Fermentation Degrades Wheat Alpha-Amylase/Trypsin Inhibitor (ATI) and Reduces Pro-Inflammatory Activity

The ingestion of gluten-containing foods can cause wheat-related disorders in up to 15% of wheat consuming populations. Besides the role of gluten, α-amylase/trypsin inhibitors (ATI) have recently been identified as inducers of an innate immune response via toll-like receptor 4 in celiac disease and non-celiac wheat sensitivity. ATI are involved in plant self-defense against insects and possibly in grain development. Notably, they are largely resistant to gastrointestinal proteases and heat, and their inflammatory activity affects not only the intestine, but also peripheral organs. The aim of this study was to understand the changes of ATI throughout the sourdough and yeast-fermented bread-making processes. ATI tetramers were isolated, fluorescein-labelled, and added to a mini-dough bread-making system. When the pH decreased below 4.0 in sourdough fermentation, the ATI tetramers were degraded due to the activation of aspartic proteases, whilst in yeast fermentation, ATI tetramers remained intact. The amylase inhibitory activity after sourdough fermentation decreased significantly, while the concentration of free thiol groups increased. The glutathione reductase activity of Fructilactobacillus sanfranciscensis did not contribute to the reduction of ATI tetramers. Compared to the unfermented wheat, sourdough fermentation was able to decrease the release of pro-inflammatory cytokines monocyte chemoattractant protein-1 (MCP-1) and tumor necrosis factor alpha (TNF-α) in quantitative ATI extracts added to the human monocytic cell line THP-1. The current data suggest that sourdough fermentation can degrade ATI structure and bioactivity, and point to strategies to improve product development for wheat sensitivity patients

Sourdough Fermentation Degrades Wheat Alpha-Amylase/Trypsin Inhibitor (ATI) and Reduces Pro-Inflammatory Activity

The ingestion of gluten-containing foods can cause wheat-related disorders in up to 15% of wheat consuming populations. Besides the role of gluten, α-amylase/trypsin inhibitors (ATI) have recently been identified as inducers of an innate immune response via toll-like receptor 4 in celiac disease and non-celiac wheat sensitivity. ATI are involved in plant self-defense against insects and possibly in grain development. Notably, they are largely resistant to gastrointestinal proteases and heat, and their inflammatory activity affects not only the intestine, but also peripheral organs. The aim of this study was to understand the changes of ATI throughout the sourdough and yeast-fermented bread-making processes. ATI tetramers were isolated, fluorescein-labelled, and added to a mini-dough bread-making system. When the pH decreased below 4.0 in sourdough fermentation, the ATI tetramers were degraded due to the activation of aspartic proteases, whilst in yeast fermentation, ATI tetramers remained intact. The amylase inhibitory activity after sourdough fermentation decreased significantly, while the concentration of free thiol groups increased. The glutathione reductase activity of Fructilactobacillus sanfranciscensis did not contribute to the reduction of ATI tetramers. Compared to the unfermented wheat, sourdough fermentation was able to decrease the release of pro-inflammatory cytokines monocyte chemoattractant protein-1 (MCP-1) and tumor necrosis factor alpha (TNF-α) in quantitative ATI extracts added to the human monocytic cell line THP-1. The current data suggest that sourdough fermentation can degrade ATI structure and bioactivity, and point to strategies to improve product development for wheat sensitivity patients

An Adaptive Mutation in Enterococcus faecium LiaR Associated with Antimicrobial Peptide Resistance Mimics Phosphorylation and Stabilizes LiaR in an Activated State

The cyclic antimicrobial lipopeptide daptomycin (DAP) triggers the LiaFSR membrane stress response pathway in enterococci and many other Gram-positive organisms. LiaR is the response regulator that, upon phosphorylation, binds in a sequence-specific manner to DNA to regulate transcription in response to membrane stress. In clinical settings, non-susceptibility to DAP by Enterococcus faecium is correlated frequently with a mutation in LiaR of Trp73 to Cys (LiaRW73C). We have determined the structure of the activated E. faecium LiaR protein at 3.2 Å resolution and, in combination with solution studies, show that the activation of LiaR induces the formation of a LiaR dimer that increases LiaR affinity at least 40-fold for the extended regulatory regions upstream of the liaFSR and liaXYZ operons. In vitro, LiaRW73C induces phosphorylation-independent dimerization of LiaR and provides a biochemical basis for non-susceptibility to DAP by the upregulation of the LiaFSR regulon. A comparison of the E. faecalis LiaR, E. faecium LiaR, and the LiaR homolog from Staphylococcus aureus (VraR) and the mutations associated with DAP resistance suggests that physicochemical properties such as oligomerization state and DNA specificity, although tuned to the biology of each organism, share some features that could be targeted for new antimicrobials

Determinación de los principales efectos ambientales en humedales debido a la variación climática en la ciudad de Bogotá D.C. como un análisis del cambio climático

La variación de los diferentes parámetros climáticos como la temperatura ambiente, la precipitación, la evaporación, la humedad relativa y el brillo solar en la ciudad de Bogotá, causada tanto por factores antrópicos como naturales, tienen un efecto en los humedales. Dichos efectos cambian la dinámica y la función ecológica de los humedales convirtiéndolos en ecosistemas frágiles. De esta manera los humedales pierden su estructura ecológica, y su aporte a la mitigación del cambio climático se ve seriamente limitado, y por el contrario los fenómenos de variabilidad climática, como el fenómeno del niño y la niña, golpean seriamente las zonas ocupadas por estos ecosistemas, trayendo graves inundaciones en época de lluvias y sequias en épocas de estiaje. La intervención del hombre en la integridad del ecosistema, a causa de la expansión urbana (ocasionada por la mala planeación distrital), en áreas inundables de los humedales, transforma el microclima de dicha área, aumentando la vulnerabilidad del ecosistema, a pesar de la protección actual que se le brinda al hábitat por parte de la secretaria distrital de ambiente de Bogotá y la empresa de acueducto y alcantarillado de Bogotá