Bacterial Active Community Cycling in Response to Solar Radiation and Their Influence on Nutrient Changes in a High-Altitude Wetland

Indexación: Web of Science; Scopus.Microbial communities inhabiting high-altitude spring ecosystems are subjected to extreme changes in solar irradiance and temperature throughout the diel cycle. Here, using 16S rRNA gene tag pyrosequencing (cDNA) we determined the composition of actively transcribing bacteria from spring waters experimentally exposed through the day (morning, noon, and afternoon) to variable levels of solar radiation and light quality, and evaluated their influence on nutrient recycling. Solar irradiance, temperature, and changes in nutrient dynamics were associated with changes in the active bacterial community structure, predominantly by Cyanobacteria, Verrucomicrobia, Proteobacteria, and 35 other Phyla, including the recently described Candidate Phyla Radiation (e.g., Parcubacteria, Gracilibacteria, OP3, TM6, SR1). Diversity increased at noon, when the highest irradiances were measured (3.3-3.9 H', 1125 W m(-2)) compared to morning and afternoon (0.6-2.8 H'). This shift was associated with a decrease in the contribution to pyrolibraries by Cyanobacteria and an increase of Proteobacteria and other initially low frequently and rare bacteria phyla (< 0.5%) in the pyrolibraries. A potential increase in the activity of Cyanobacteria and other phototrophic groups, e.g., Rhodobacterales, was observed and associated with UVR, suggesting the presence of photo activated repair mechanisms to resist high levels of solar radiation. In addition, the percentage contribution of cyanobacterial sequences in the afternoon was similar to those recorded in the morning. The shifts in the contribution by Cyanobacteria also influenced the rate of change in nitrate, nitrite, and phosphate, highlighted by a high level of nitrate accumulation during hours of high radiation and temperature associated with nitrifying bacteria activity. We did not detect ammonia or nitrite oxidizing bacteria in situ, but both functional groups (Nitrosomona and Nitrospira) appeared mainly in pyrolibraries generated from dark incubations. In total, our results reveal that both the structure and the diversity of the active bacteria community was extremely dynamic through the day, and showed marked shifts in composition that influenced nutrient recycling, highlighting how abiotic variation affects potential ecosystem functioning.http://journal.frontiersin.org/article/10.3389/fmicb.2016.01823/ful

Microbial Activity Response to Solar Radiation across Contrasting Environmental Conditions in Salar de Huasco, Northern Chilean Altiplano

Indexación: Web of Science; Scopus.In high altitude environments, extreme levels of solar radiation and important differences of ionic concentrations over narrow spatial scales may modulate microbial activity. In Salar de Huasco, a high-altitude wetland in the Andean mountains, the high diversity of microbial communities has been characterized and associated with strong environmental variability. Communities that differed in light history and environmental conditions, such as nutrient concentrations and salinity from different spatial locations, were assessed for bacterial secondary production (BSP, H-3-leucine incorporation) response from short-term exposures to solar radiation. We sampled during austral spring seven stations categorized as: (a) source stations, with recently emerged groundwater (no-previous solar exposure); (b) stream running water stations; (c) stations connected to source waters but far downstream from source points; and (d) isolated ponds disconnected from ground sources or streams with a longer isolation and solar exposure history. Very high values of 0.25 mu E m(-2) s(-1), 72 W m(-2) and 12 W m(-2) were measured for PAR, UVA, and UVB incident solar radiation, respectively. The environmental factors measured formed two groups of stations reflected by principal component analyses (near to groundwater sources and isolated systems) where isolated ponds had the highest BSP and microbial abundance (35 microalgae taxa, picoeukaryotes, nanoflagellates, and bacteria) plus higher salinities and PO43- concentrations. BSP short-term response (4 h) to solar radiation was measured by H-3-leucine incorporation under four different solar conditions: full sun, no UVB, PAR, and dark. Microbial communities established in waters with the longest surface exposure (e.g., isolated ponds) had the lowest BSP response to solar radiation treatments, and thus were likely best adapted to solar radiation exposure contrary to ground source waters. These results support our light history (solar exposure) hypothesis where the more isolated the community is from ground water sources, the better adapted it is to solar radiation. We suggest that factors other than solar radiation (e.g., salinity, PO43-, NO3-) are also important in determining microbial productivity in heterogeneous environments such as the Salar de Huasco.http://journal.frontiersin.org/article/10.3389/fmicb.2016.01857/ful

Causas antrópicas, efectos socioeconómicos y las medidas de mitigación y adaptación del cambio climático sobre la producción de cacao en las cooperativas Pedro Sergio y Petrona Hernández del municipio Rancho Grande, departamento de Matagalpa durante el segundo semestre del 2010

En el presente trabajo se analizaron las causas antrópicas, el efecto socioeconómico del cambio climático al sector cacao, en el departamento de Matagalpa municipio de Rancho Grande, comunidades colonia agrícola Nº1 y Nº2, durante el II semestre del 2010. El objetivo de la investigación es conocer las causas antrópicas, efectos socioeconómicos del cambio climático en el sector cacao, el cual los resultados lo obtuvimos por medios de instrumentos investigativos, donde se evidencia que nuestro sector emite gases de efecto invernadero estos ocasionadas por las prácticas agrícolas que los productores implementan en su producción, provocando efectos tanto ambiental, económico y social, ocasionando así vulnerabilidad. Con el estudio se genera información, la cual permite la obtención de conocimientos la implementación de nuevas prácticas agrícolas, la que nos permitirá abrir paso a la implementación de medidas de mitigación y adaptación, para contrarrestar los efectos del cambio climátic

{2,2′-[4-Chloro-5-methyl-o-phenyl­enebis(nitrilo­methyl­idyne)]diphenolato}nickel(II)

In the title complex, [Ni(C21H15ClN2O2)], the NiII ion is coordinated by two N and two O atoms from the tetra­dentate Schiff base ligand in a distorted square geometry. The crystal packing exhibits short inter­molecular Ni⋯Ni distances of 3.273 (3) Å

Evaluation of direct sample injection as a fast, no-sample handling, approach for the LC-MS/MS monitoring of pharmaceuticals in different water matrices

The determination of drug residues in water, particularly in environmental water, is a hot topic due to the usual presence of these emerging contaminants in the aquatic environment and their potential negative impact on water quality. The most widely approach applied at present for their determination is the use of a solid phase extraction (SPE) step followed by the LC-MS/MS measurement. This is due to the theoretical need to preconcentrate the analytes and to produce “clean” sample extracts leading to less inferences in subsequent analysis. However, in LC-MS/MS based methods, the main interferences are not “visible” and are mostly due to matrix effects, which in fact are produced by unknown compounds that co-elute with the analytes and therefore not easily removed by SPE. As an alternative, an increasing trend is observed towards the use of direct injection (DI) of the samples, which is nowadays possible thank to the notable improvement in sensitivity of modern LCMS/MS instrumentation. In this work, both approaches, SPE and DI, have been evaluated for the determination of 16 pharmaceuticals in three different types of water: groundwater, surface water and effluent wastewater. The study has been performed by using pharmaceutical reference standards and their corresponding isotope-labelled internal standards (ILIS) for efficient matrix effects correction. Both methodologies have been compared in terms of matrix effects, sensitivity, and suitability for the analysis of real-world water samples. Our data show that DI is an efficient alternative to SPE, with satisfactory analyte recoveries for most pharmaceuticals, matrix effects even lower than in SPE, and sufficient sensitivity for most of applications. In addition, the absence of sample treatment minimizes potential errors associated with this step, and there is a notable saving in the analysis time and costs. The analysis of Quality Control (QC) samples included in different sample batch sequences has been used to support the feasibility of using DI in this type of analysis.Funding for open access charge: CRUE-Universitat Jaume

Women, Health and Aging: Building a Statewide Movement

Provides an overview of current policy and program environments that affect the state's most vulnerable elder population, and considers some effective strategies to address the growing needs of older persons in California

Relacion entre el sindrome de friccion de la banda iliotibial y el dolor lumbar en 8 ciclistas

49 p.El Síndrome de Fricción de la Banda Iliotibial (SFBIT) es una lesión por sobre uso común en ciclistas, corredores de fondo y personal militar, que se expresa como dolor en la región lateral de la rodilla. El objetivo de este trabajo es evaluar la Banda Iliotibial (BIT) de 8 ciclistas y relacionar su disfunción con la presencia de dolor lumbar. Material y método: se analizaron los resultados de una encuesta que contenía los datos personales y la presencia o ausencia de dolor en las rodillas y dolor lumbar. Asimismo se evaluó mediante tres pruebas especiales (Ober, Noble y Renne) el grado de flexibilidad- acortamiento de la BIT y el hallazgo de dolor a la palpación de ésta. Por último se aplicó el Indice de discapacidad de Oswestry de manera de conocer la implicancia de la lumbalgia en las actividades de la vida diaria. Resultados: la media para la edad fue de 16,6 años, siendo la moda y la mediana de 17 años. El 62,5% de los jóvenes presentó dolor de rodilla, existiendo un predominio unilateral, ya sea izquierda o derecha. El tipo de dolor que padecen más comúnmente es del tipo punzante localizándose mayormente en la cara medial de la rodilla. Todos los jóvenes que relataron haber presentado dolor lumbar (50%) tenían diferentes tipos de dolores. Estos a su vez se distribuyeron de igual forma entre la zona lumbar media y baja. El 62.5% presentó dolor a la palpación de la BIT. Conclusión: el estudio demuestra que no existe una relación estadísticamente significativa entre una BIT disfuncional (SFBIT) y el dolor lumbar en los 8 ciclistas evaluados (P>0.05