Degradation capability of the coastal environment adjacent to the Itata River in central Chile (36.5° S)

The response of the coastal ocean influenced by both river discharges and inputs of photosynthetically derived organic carbon product of upwelling, was evaluated by estimating rates of microbial hydrolysis of macromolecules with the goal of estimating the potential degradation capability of the coastal ecosystem off central Chile. Extracellular enzymatic activity (EEA) in seawater was dominated by aminopeptidase activity on substrate L-leucine-4-methyl-7-coumarinylamide (MCA-leu) (1.2 to 182 nmol l⁻¹ h⁻¹) followed by 4-methylumbelliferyl-ß-D-glucoside (MUF-glu) (0.08–61 nmol l⁻¹ h⁻¹) and 4-methylumbelliferyl-ß-D-cellobiose (MUF-cel) (0.15–7 nmol l⁻¹ h⁻¹), with the highest rates measured during spring-summer. In riverine waters, extracellular enzymatic hydrolysis remained within the range of 45 to 131 nmol l⁻¹ h⁻¹ for MCA-leu and ca. 20 nmol l⁻¹ h⁻¹ for glucosidic substrates, year-round. Contrary to the EEA observed for the marine water column, surface sediment extracellular enzymatic hydrolysis of MCA-leu (0.04 to 6.13 nmol g⁻¹ dw h⁻¹) was in the same order of magnitude as the rates observed for MUF-cel (0.004 to 5.1 nmol g⁻¹ dw h⁻¹) and MUF-glu (0.007 to 10.5 nmol g⁻¹ dw h⁻¹). Moreover, hydrolysis in sediments was characterized by higher rates during winter compared with spring-summer in the coastal and estuarine zone. The five years of data allowed us to evaluate the potential capability of microbial processing of organic carbon in the coastal area adjacent to the Itata river discharge where the increase in primary production in the productive seasons is accompanied by the increase in hydrolysis of macromolecules

Curvature singularity of the distributional BTZ black hole geometry

For the non-rotating BTZ black hole, the distributional curvature tensor field is found. It is shown to have singular parts proportional to a $\delta$-distribution with support at the origin. This singularity is related, through Einstein field equations, to a point source. Coordinate invariance and independence on the choice of differentiable structure of the results are addressed.Comment: Latex, 7 page

Diferencias y similitudes entre percepción y autopercepción de administradores universitarios y su líder

Se condujo un análisis comparativo entre las percepciones que los admi- nistradores universitarios tienen sobre el estilo de liderazgo de su director y la propia autoevaluación de este último, en una universidad pública estatal (UPE) en México. Se utilizó la herramienta “Perfil gerencial 5-D” desarrollada por Nosnik (2013), así que apoyándose en las teorías de Karl Pooper (demarcación de la ciencia) y de Imre Lakatos (metodología de los programas de investigación científica), genera perfiles gerenciales basados en la metodología de los sistemas heurísticos (MSH). El objetivo fue contar con un análisis comparativo de percepciones que sirva a la reflexión de los líderes en la búsqueda de mejora continua de su estilo. Los resultados detectaron las áreas de oportunidad existentes para la mejora en los estilos de liderazgo de los directores y proporcionan un estudio de caso aplicable en otras universidades

Uma solução da equação de difusão-advecção com termo contragradiente

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Indicadores de desempeño académico como predictores de captación de recursos financieros

El presente estudio abordó el ámbito de las Universidades Públicas Estatales (UPE) en México, para determinar la posible existencia de una correlación entre el desempeño de estas en los indicadores de excelencia académica y el nivel de asignación de recursos financieros obtenidos de las principales fuentes de financiamiento del gobierno federal. Mediante la determinación de los indicadores académicos y financieros utilizados por los organismos internacionales y nacionales más importantes se construyó una propuesta metodológica de análisis estadístico, con el fin de evaluar el desempeño académico de las UPE y su correlación con la consecución de recursos financieros. Los resultados mostraron que no existe suficiente evidencia para inferir que la obtención de mejores resultados académicos en las UPE mexicanas es un predictor confiable de mejor captación de dichos recursos. De esta manera se expone la necesidad de una política clara en la asignación de recursos a las instituciones

Palladium iodide-catalyzed selective carbonylative double cyclization of 4-(2-aminophenyl)-3-yn-1-ols to dihydrofuroquinolinone derivatives

The PdI2/KI‐catalyzed oxidative carbonylation of 4‐(2‐aminophenyl)‐3‐yn‐1‐ols, bearing two potential nucleophilic groups in suitable position selectively leads to dihydrofuroquinolinone derivatives in fair to high yields (60%—89%) and excellent turnover numbers (180—267 mol of product per mol of Pd) over 19 examples, through a mechanistic pathway involving initial O‐cyclization followed by N‐cyclocarbonylation. In such process, the selective catalytic construction of two rings and three new bonds is achieved in one synthetic step to afford high value added fused heterocyclic structures starting from readily available materials

Substrato para crescimento de mudas de tucumanzeiro-do-pará.

O trabalho foi desenvolvido como objetivo de verificar a influência do tipo de substrato sobre o crescimento de mudas de tucumanzeiro-do-pará. Como substrato foram usadas as seguintes misturas: a) solo, b) solo + 1 grama de NPK na formulação (10.28.20), c) solo + 10% de cama de aviário, d) solo + 20% de cama de aviário, e) solo + 30% de cama de aviário, f) solo + 40% de cama de aviário. Para a análise de variância foi adotado o delineamento inteiramente casualizado com quatro repetições em esquema fatorial de dois fatores, sendo seis tipos de substrato e quatro períodos de avaliação. Foram feitas as seguintes avaliações, diâmetro do coleto e altura da muda aos 0, 60, 120 e 180 dias após a instalação do experimento. Não houve interação significativa entre os fatores tipo de substrato e período de avaliação. Pelos resultados obtidos, observa-se crescimento lento das mudas em todos os tipos de substrato usados. Apenas para o período de avaliação feito aos 180 dias foi encontrado diferença significativa em relação aos demais períodos. Nas condições em que foi realizado o experimento pode-se concluir que, durante o período avaliado, o tipo de substrato usado não tem efeito sobre o crescimento de mudas de Astrocaryum vulgare

Granting of credit in organic family production.

Despite the relevance of credit lines for the development of organic production system activities, the access by producers, especially family producers, to specific lines for this purpose is still extremely low. Therefore, this study aims to analyze the reasons why organic producers do not have access to government financial credit lines, in particular, from the Brazilian Program for Strengthening Family Agriculture´s (PRONAF) “Green Lines”. As to the methodology, this is an applied and descriptive research, which integrates quantitative and qualitative approaches with non-probabilistic sampling due to its accessibility and convenience. An electronic questionnaire was sent via WhatsApp application to 2,325 producers included in the National Register of Organic Producers, and the data obtained underwent statistical and content analysis. The data showed that most producers carry out organic production activities with their own resources and that the most prominent reasons for not taking out credit in specific credit lines for organic production are linked to the credit granting process. Furthermore, the findings indicated a necessity to reassess the granting lines, aiming to make them more commercially attractive and less bureaucratic, considering the specificities of producers and the organic production system