Comunidades de líquenes: indicadores de la calidad del aire en la ciudad de La Paz, Bolivia

El presente trabajo evaluó la calidad del aire en la ciudad de La Paz, usando elÍndice de Pureza Atmosférica (IAP). Este método está basado en las alteraciones queproduce la contaminación atmosférica sobre las comunidades de los líquenes. Deacuerdo con este método, la presencia de especies tolerantes o sensibles y lamodificación en la estructura y abundancia de la comunidad liquénica, por si misma,son capaces de expresar la calidad del aire de un área específica. Este método permite,de manera integral, clasificar las diferentes áreas estudiadas con relación al nivel decontaminación, y fue aplicado en un transecto determinado por la principal fuente decontaminación, el tráfico vehicular, en diferentes áreas de la ciudad. Los resultadosmuestran que en áreas de alta intensidad vehicular, consecuentemente máscontaminadas, existe menor diversidad de líquenes, además de valores bajos depresencia y cobertura. Por otro lado, las áreas con menor contaminación registranmayor diversidad liquénica y valores mayores de cobertura y presencia. El método IAPpuede ser considerado como una herramienta fácil y económica de aplicar en lamedición de la calidad del aire utilizando bioindicadores

A Causal Discovery Approach To Learn How Urban Form Shapes Sustainable Mobility Across Continents

Global sustainability requires low-carbon urban transport systems, shaped by adequate infrastructure, deployment of low-carbon transport modes and shifts in travel behavior. To adequately implement alterations in infrastructure, it's essential to grasp the location-specific cause-and-effect mechanisms that the constructed environment has on travel. Yet, current research falls short in representing causal relationships between the 6D urban form variables and travel, generalizing across different regions, and modeling urban form effects at high spatial resolution. Here, we address all three gaps by utilizing a causal discovery and an explainable machine learning framework to detect urban form effects on intra-city travel based on high-resolution mobility data of six cities across three continents. We show that both distance to city center, demographics and density indirectly affect other urban form features. By considering the causal relationships, we find that location-specific influences align across cities, yet vary in magnitude. In addition, the spread of the city and the coverage of jobs across the city are the strongest determinants of travel-related emissions, highlighting the benefits of compact development and associated benefits. Differences in urban form effects across the cities call for a more holistic definition of 6D measures. Our work is a starting point for location-specific analysis of urban form effects on mobility behavior using causal discovery approaches, which is highly relevant for city planners and municipalities across continents.Comment: 22 pages, 13 figures, 4 table

Estandarización de métodos de cultivo y exposición para estudios de biomonitoreo

En el presente trabajo se sintetizan las experiencias obtenidas para el rediseño yadecuación de métodos estandarizados para el cultivo y exposición controlada deLolium multiflorum, Raphanus sativus, Tradescantia pallida y Vicia faba con el objeto deutilizarlos como bioindicadores activos de calidad del aire en las ciudades de La Paz yEl Alto

I Diretrizes do Grupo de Estudos em Cardiogeriatria da Sociedade Brasileira de Cardiologia

O idoso apresenta características próprias na manifestação das doenças, na resposta à terapêutica e no efeito colateral dos medicamentos. Constitui um grupo de maior risco para o aparecimento das doenças degenerativas, em geral, e cardiovasculares, em particular, além de apresentar maior número de comorbidades

Crescimento inicial da soja em resposta a modificação na reflexão da luz por superfícies coloridas

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Efeito de fatores do ambiente no manejo de sorgo para formação de cobertura morta no sistema de semeadura direta : II-temperatura

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T-type Ca2+ channels, SK2 channels and SERCAs gate sleep-related oscillations in thalamic dendrites.

International audienceT-type Ca2+ channels (T channels) underlie rhythmic burst discharges during neuronal oscillations that are typical during sleep. However, the Ca2+-dependent effectors that are selectively regulated by T currents remain unknown. We found that, in dendrites of nucleus reticularis thalami (nRt), intracellular Ca2+ concentration increases were dominated by Ca2+ influx through T channels and shaped rhythmic bursting via competition between Ca2+-dependent small-conductance (SK)-type K+ channels and Ca2+ uptake pumps. Oscillatory bursting was initiated via selective activation of dendritically located SK2 channels, whereas Ca2+ sequestration by sarco/endoplasmic reticulum Ca2+-ATPases (SERCAs) and cumulative T channel inactivation dampened oscillations. Sk2-/- (also known as Kcnn2) mice lacked cellular oscillations, showed a greater than threefold reduction in low-frequency rhythms in the electroencephalogram of non-rapid-eye-movement sleep and had disrupted sleep. Thus, the interplay of T channels, SK2 channels and SERCAs in nRt dendrites comprises a specialized Ca2+ signaling triad to regulate oscillatory dynamics related to sleep

Modeling of Reactivity Controlled Compression Ignition Combustion Using a Stochastic Reactor Model Coupled with Detailed Chemistry

Advanced combustion concepts such as reactivity controlled compression ignition (RCCI) have been proven to be capable of fundamentally improve the conventional Diesel combustion by mitigating or avoiding the soot-NOx trade-off, while delivering comparable or better thermal efficiency. To further facilitate the development of the RCCI technology, a robust and possibly computationally efficient simulation framework is needed. While many successful studies have been published using 3D-CFD coupled with detailed combustion chemistry solvers, the maturity level of the 0D/1D based software solution offerings is relatively limited. The close interaction between physical and chemical processes challenges the development of predictive numerical tools, particularly when spatial information is not available. The present work discusses a novel stochastic reactor model (SRM) based modeling framework capable of predicting the combustion process and the emission formation in a heavy-duty engine running under RCCI combustion mode. The combination of physical turbulence models, detailed emission formation sub-models and state-of-the-art chemical kinetic mechanisms enables the model to be computationally inexpensive compared to the 3D-CFD approaches. A chemical kinetic mechanism composed of 248 species and 1428 reactions was used to describe the oxidation of gasoline and diesel using a primary reference fuel (PRF) mixture and n-heptane, respectively. The model is compared to operating conditions from a single-cylinder research engine featuring different loads, speeds, EGR and gasoline fuel fractions. The model was found to be capable of reproducing the combustion phasing as well as the emission trends measured on the test bench, at some extent. The proposed modeling approach represents a promising basis towards establishing a comprehensive modeling framework capable of simulating transient operation as well as fuel property sweeps with acceptable accuracy