406 research outputs found
An improved near-real-Time precipitation retrieval for Brazil
Observations from geostationary satellites can provide spatially continuous coverage at continental scales with high spatial and temporal resolution. Because of this, they are commonly used to complement ground-based precipitation measurements, whose coverage is often more limited. We present Hydronn, a neural-network-based, near-real-Time precipitation retrieval for Brazil based on visible and infrared (Vis-IR) observations from the Advanced Baseline Imager (ABI) on the Geostationary Operational Environmental Satellite 16 (GOES-16). The retrieval, which employs a convolutional neural network to perform Bayesian precipitation retrievals, was developed with the aims of (1) leveraging the full potential of latest-generation geostationary observations and (2) providing probabilistic precipitation estimates with well-calibrated uncertainties. The retrieval is trained using more than 3 years of collocations with combined radar and radiometer retrievals from the Global Precipitation Measurement (GPM) core observatory over South America. The accuracy of instantaneous precipitation estimates is assessed using a separate year of GPM combined retrievals and compared to retrievals from passive microwave (PMW) sensors and HYDRO, the Vis-IR retrieval that is currently in operational use at the Brazilian Institute for Space Research. Using all available channels of the ABI, Hydronn achieves accuracy close to that of state-of-The-Art PMW precipitation retrievals in both precipitation estimation and detection despite the lower information content of the Vis-IR observations. Hourly, daily, and monthly precipitation accumulations are evaluated against gauge measurements for June and December 2020 and compared to HYDRO, the Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks (PERSIANN) Cloud Classification System (CCS), and the Integrated Multi-satellitE Retrievals for GPM (IMERG). Compared to HYDRO, Hydronn reduces the mean absolute error for hourly accumulations by 21% (22%) compared to HYDRO by 44% (41%) for the mean squared error (MSE) and increases the correlation by 138% (312%) for June (December) 2020. Compared to IMERG, the improvements correspond to 16% (14%), 12% (12%), and 20% (56%), respectively. Furthermore, we show that the probabilistic retrieval is well calibrated against gauge measurements when differences in the distributions of the training data and the gauge measurements are accounted for. Hydronn has the potential to significantly improve near-real-Time precipitation retrievals over Brazil. Furthermore, our results show that precipitation retrievals based on convolutional neural networks (CNNs) that leverage the full range of available observations from latest-generation geostationary satellites can provide instantaneous precipitation estimates with accuracy close to that of state-of-The-Art PMW retrievals. The high temporal resolution of the geostationary observation allows Hydronn to provide more accurate precipitation accumulations than any of the tested conventional precipitation retrievals. Hydronn thus clearly shows the potential of deep-learning-based precipitation retrievals to improve precipitation estimates from currently available satellite imagery
Dopaminergic and glutamatergic signaling crosstalk in Huntington's disease neurodegeneration : the role of p25/cyclin-dependent kinase 5
Altered glutamatergic and dopaminergic signaling has been proposed as contributing to the specific striatal cell death observed in Huntington's disease (HD). However, the precise mechanisms by which mutant huntingtin sensitize striatal cells to dopamine and glutamate inputs remain unclear. Here, we demonstrate in knock-in HD striatal cells that mutant huntingtin enhances dopaminemediated striatal cell death via dopamineD1 receptors. Moreover, we show thatNMDAreceptors specifically potentiate the vulnerability of mutant huntingtin striatal cells to dopamine toxicity as pretreatment withNMDAincreased D1R-induced cell death in mutant but not wild-type cells. As potential underlying mechanism of increased striatal vulnerability, we identified aberrant cyclin-dependent kinase 5 (Cdk5) activation. We demonstrate that enhanced Cdk5 phosphorylation and increased calpain-mediated conversion of the Cdk5 activator p35 into p25 may account for the deregulation of Cdk5 associated to dopamine and glutamate receptor activation in knock-in HD striatal cells. Moreover, supporting a detrimental role of Cdk5 in striatal cell death, neuronal loss can be widely prevented by roscovitine, a potent Cdk5 inhibitor. Significantly, reduced Cdk5 expression together with enhanced Cdk5 phosphorylation and p25 accumulation also occurs in the striatum of mutant HdhQ111 mice and HD human brain suggesting the relevance of deregulated Cdk5 pathway in HD pathology. These findings provide new insights into the molecular mechanisms underlying the selective vulnerability of striatal cells in HD and identify p25/Cdk5 as an important mediator of dopamine and glutamate neurotoxicity associated to HD
Hepatitis autoimnune. Diagnòstic, característiques clíniques i resposta al tractament
La hepatitis autoimmune (HAI) és una patologia inflamatòria crónica hepàtica, progressiva i d'origen desconegut d'àmplia variabilitat clínica. S'estudiaren 40 casos (edad mitjana 50.8 anys, 82,5% dones). Al nostre medi la majoria de casos d'HAI són de tipus 1, el 40% debuten en forma d'hepatitis aguda i tenen una malaltia autoimmune associada. El 60% van rebre incialment monoteràpia amb corticoides i el 32,5% associats a azatioprina. Al 94% s'aconsegueix la remissió independentment de la pauta terapèutica i és més freqüent si l'AST està augmentada
EXPLORING KEY MOMENTS OF EMPOWERMENT OF YOUNG PEOPLE THROUGH THEIR OWN LIFE STORIES
En el presente artículo se presentan los relatos de seis jóvenes que han compartido su percepción sobre lo que ellos creen que les ha empoderado, con el objetivo de identificar los momentos, espacios y procesos que han contribuido a él. Hemos compartido con
ellos la definición de empoderamiento construida en el proyecto HEBE como detonante para
su relato. Después de hacer una breve referencia a la complejidad del concepto de empoderamiento, se presenta la estrategia metodológica utilizada y se detalla el proceso de selección
de relatores, el proceso narrativo y se presentan los resultados más relevantes respecto a los
momentos, espacios y procesos identificados. Se integran las aportaciones de los jóvenes con
el análisis y selección que hacen los investigadores de los contenidos de los mismos, a partir
de una mirada en profundidad de cada relato pero también poniéndolos en relación, triangulando la información que nos ofrecen los diferentes relatores. Destacan espacios como son la
familia, la formación, el trabajo o la vida asociativa. Momentos tales como la mirada del otro,
los incidentes críticos o la adolescencia y procesos como la toma de decisiones, el reconocimiento de los otros o la acción. Se concluyen con algunos elementos relevantes que emergen
de sus relatos así como algunas cuestiones aún pendientes.
This article presents the stories of six young people who shared their perceptions of what they believe has empowered them. The aim was to identify those moments,
places and processes that have contributed to this empowerment. The starting point for their
stories was the definition of empowerment provided by the HEBE project. After briefly discussing the complex nature of the concept of empowerment, the methodological strategy
used will be explained, followed by a description of the narrative process and of how the
young participants were selected. Then the most important findings regarding the moments,
places and processes identified will be discussed. These include the contributions made by
the young participants, together with the analysis and extracts selected by the researchers.
Each story will be examined in depth and linked to the others, thus triangulating the data provided by each participant. Places such as family and work environments and community life
are particularly emphasized, as are moments and periods such as the gaze of others, critical
incidents, and adolescence, together with processes such as decision making, the recognition
of others and action. The article concludes with a number of important elements that arose in
the stories, as well as some questions that still remain to be answered
Trabajo en casa y plan de emergencias
Teniendo en cuenta la modalidad de “trabajo en casa” que trajo consigo la pandemia ocasionada por el COVID-19 la Universidad Militar Nueva Granada por medio del Programa de Administración de Riesgos, Seguridad y Salud en el Trabajo realizó un proyecto de investigación titulado “Condiciones ergonómicas y de seguridad en los trabajadores remotos (trabajo en casa) tras la pandemia de COVID-19”, en el que se buscaba identificar los factores de riesgo presentes en los entornos laborales de las personas, calificar los riesgos y generar estrategias de intervención que buscarán su control; es así como surge la idea de gestionar el factor de riesgo de seguridad ligado al plan de emergencias correspondiente a la casa del trabajador o de su entorno, en caso de que viviera en edificio o en conjuntos residenciales. De esta forma, fortalecer las estrategias no solo de salud laboral, sino también de prevención de desastres, buscando un perfeccionamiento en las estrategias, evitando un impacto negativo para la salud, para la seguridad y para el medio ambiente de cada persona.
Conociendo la importancia de generar lugares de trabajo sanos y seguros para los trabajadores y dando cumplimiento a la normatividad legal vigente en materia de Seguridad y Salud en el Trabajo se plantea la necesidad de inspeccionar y verificar los lugares de trabajo en los que se estuvieron desarrollando las labores durante el tiempo de pandemia y aún más en la actualidad en la que dicha modalidad de trabajo tomó fuerza y se quedó en nuestro país mediante la Ley 2088 de 2021 y el Decreto 649 de 2022 o migró a otras modalidades como el Teletrabajo, reglamentada por la Ley 1221 de 2008 y el Decreto 884 de 2012
Diurnal variability of atmospheric O-2, CO2, and their exchange ratio above a boreal forest in southern Finland
The exchange ratio (ER) between atmospheric O(2 )and CO2 is a useful tracer for better understanding the carbon budget on global and local scales. The variability of ER (in mol O(2 )per mol CO2) between terrestrial ecosystems is not well known, and there is no consensus on how to derive the ER signal of an ecosystem, as there are different approaches available, either based on concentration (ERatmos) or flux measurements (ERforest). In this study we measured atmospheric O-2 and CO2 concentrations at two heights (23 and 125 m) above the boreal forest in Hyytiala, Finland. Such measurements of O-2 are unique and enable us to potentially identify which forest carbon loss and production mechanisms dominate over various hours of the day. We found that the ERatmos signal at 23 m not only represents the diurnal cycle of the forest exchange but also includes other factors, including entrainment of air masses in the atmospheric boundary layer before midday, with different thermodynamic and atmospheric composition characteristics. To derive ERforest, we infer O(2 )fluxes using multiple theoretical and observation-based micro-meteorological formulations to determine the most suitable approach. Our resulting ERforest shows a distinct difference in behaviour between daytime (0.92 +/- 0.17 mol mol(-1)) and nighttime (1.03 +/- 0.05 mol mol(-1)). These insights demonstrate the diurnal variability of different ER signals above a boreal forest, and we also confirmed that the signals of ERatmos and ERforest cannot be used interchangeably. Therefore, we recommend measurements on multiple vertical levels to derive O-2 and CO2 fluxes for the ERforest signal instead of a single level time series of the concentrations for the ERatmos signal. We show that ERforest can be further split into specific signals for respiration (1.03 +/-; 0.05 mol mol-1) and photosynthesis (0.96 +/- 0.12 molmol(-1)). This estimation allows us to separate the net ecosystem exchange (NEE) into gross primary production (GPP) and total ecosystem respiration (TER), giving comparable results to the more commonly used eddy covariance approach. Our study shows the potential of using atmospheric O-2 as an alternative and complementary method to gain new insights into the different CO2 signals that contribute to the forest carbon budget.Peer reviewe
Otimização do processo de síntese e caracterização de MCM-48 / Synthesis process optimization and characterization of the MCM-48
As sílicas mesoporosas com geometrias regulares têm recebido atenção, devido à sua importância científica e potencial em aplicações práticas como catálise, adsorção, separação, sensoriamento, uso médico, ecológico e nanotecnológico. Em trabalho anterior do nosso grupo de pesquisa foram sintetizadas nanopartículas de sílica mesoporosa coloidal tipo MCM-48, porém estas se apresentaram agregadas. O objetivo deste trabalho foi a otimização do processo de síntese de MCM-48 para obtenção de nanopartículas desagregadas, assim como a caracterização do produto obtido. Para tanto, foi conduzido um estudo experimental com preparação de MCM-48 baseada no método de Stöber modificado. Após a síntese, os ensaios para avaliar estado de agregação, forma, tamanho e pureza do produto foram realizados por meio de análise de fase por espalhamento de luz (PALS), análise por microscopia eletrônica de varredura (MEV) e fluorescência de raio-X (EDX). Como resultado, as nanopartículas esféricas de MCM-48 foram sintetizadas (lote 1 e lote 2 com dimensões médias < 300 nm) e o rendimento foi de aproximadamente 2 %(m/m). A síntese das nanopartículas mesoporosas, esféricas e desagregadas foi alcançada neste trabalho, portanto houve otimização do processo. O rendimento do processo foi maior quando comparado ao obtido em trabalho anterior do nosso grupo de pesquisa. Na literatura pesquisada o rendimento dos processos similares não se encontrou divulgado.
Functional responses of key marine bacteria to environmental change - toward genetic counselling for coastal waters
Coastal ecosystems deteriorate globally due to human-induced stress factors, like nutrient loading and pollution. Bacteria are critical to marine ecosystems, e.g., by regulating nutrient cycles, synthesizing vitamins, or degrading pollutants, thereby providing essential ecosystem services ultimately affecting economic activities. Yet, until now bacteria are overlooked both as mediators and indicators of ecosystem health, mainly due to methodological limitations in assessing bacterial ecosystem functions. However, these limitations are largely overcome by the advances in molecular biology and bioinformatics methods for characterizing the genetics that underlie functional traits of key bacterial populations - "key" in providing important ecosystem services, being abundant, or by possessing high metabolic rates. It is therefore timely to analyze and define the functional responses of bacteria to human-induced effects on coastal ecosystem health. We posit that categorizing the responses of key marine bacterial populations to changes in environmental conditions through modern microbial oceanography methods will allow establishing the nascent field of genetic counselling for our coastal waters. This requires systematic field studies of linkages between functional traits of key bacterial populations and their ecosystem functions in coastal seas, complemented with systematic experimental analyses of the responses to different stressors. Research and training in environmental management along with dissemination of results and dialogue with societal actors are equally important to ensure the role of bacteria is understood as fundamentally important for coastal ecosystems. Using the responses of microorganisms as a tool to develop genetic counselling for coastal ecosystems can ultimately allow for integrating bacteria as indicators of environmental change.We thank for the many inspiring discussions with Ulla Li Zweifel and Åke Hagström on taking advantage of microbial genetic blueprints for informing on the health status of natural waters. We gratefully acknowledge Martin Brusin for contributing drawings of Figure 1. Research on this subject was supported by the marine strategic research program EcoChange to J. P and the BONUS BLUEPRINT project, which has received funding from BONUS, the Joint Baltic Sea Research and Development Program (Art 185), and Swedish, German and Danish research councils to JP, AA, ML and LR.Peer reviewe
O tratamento cirúrgico da diverticulite colônica aguda / Surgical treatment of acute colonic diverticulitis
A Doença Diverticular dos Cólons tem como principal característica a presença do divertículo associado aos sinais e sintomas, o divertículo é uma protrusão da mucosa e submucosa através das camadas musculares do cólon e geralmente ocorrem no local de penetração dos vasos sangíneos do cólon. A diverticulite colônica aguda caracteriza-se pela presença de perfuração dos divertículos, que pode ser pequena ou franca. A doença diverticular do cólon é uma causa importante de internações hospitalares e um contribuinte significativo para os custos de saúde em nações industrializadas. A maioria dos pacientes com diverticulite sigmóide aguda é tratada clinicamente, a cirurgia só é indicada quando a diverticulite não é tratável ou é refratária à terapia médica. Em torno de 15% dos pacientes necessitarão de cirurgia para doença diverticular, nos Estados Unidos, a doença diverticular é a principal indicação para cirurgia de cólon eletiva. Para pacientes que necessitam de cirurgia para diverticulite, a escolha das técnicas depende da estabilidade hemodinâmica do paciente, extensão da contaminação peritoneal e experiência/preferência do cirurgião. Os pacientes com sintomas persistentes ou crônicos, apesar da terapia médica, necessitam de cirurgia de urgência ou semieletiva.
Doença periodontal como fator de risco para alterações cardiovasculares: Uma análise da literatura / Periodontal disease as a risk factor for cardiovascular changes: An analysis of the literature
A doença periodontal crônica é caracterizada pela destruição dos tecidos de proteção e os de suporte dos dentes, como consequência de uma resposta inflamatória recorrente. A doença cardiovascular é um termo amplo que compreende todas as alterações patológicas que afetam o coração e/ou os vasos sanguíneos. Estudos comprovam uma relação dessas duas patologias, sendo a inflamação do periodonto uma das influenciadoras dos distúrbios cardiovasculares. O objetivo do presente trabalho foi realizar uma revisão de literatura sobre a associação da doença periodontal e a doença cardiovascular. Para esse fim, foram selecionados artigos na base de dados Pubmed com os descritores “periodontal disease” AND “cardiovascular disease”, no idioma Inglês, sendo selecionados os artigos publicados nos últimos 5 anos, obtendo assim 22 artigos. Foram selecionados apenas os artigos cadastrados no periódico CAPES, resultando no total de 10 artigos. É bastante notável a relação entre essas duas enfermidades ao levar em consideração os níveis de Proteína C reativa (PCR), fibrinogênio e algumas citocinas inflamatórias. Vale ressaltar, por exemplo, que diversos estudos científicos explicitam que indivíduos acometidos por periodontite têm uma predisposição bastante amplificada de vir a sofrer alguma doença cardiovascular, uma vez que são encontradas bactérias da doença periodontal nos vasos sanguíneos com arteriosclerose – uma doença a qual placas de gorduras se depositam nas artérias. As proteínas PCR e a TNF-? são de fase aguda monitoradas como biomarcadores da resposta inflamatória, conhecidas como um importante indicador para complicações ateroscleróticas. Pode-se concluir que a doença periodontal pode se manifestar como um fator de risco para as doenças cardiovasculares
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