23 research outputs found

    Emisión difusa de hidrógeno en el Volcán Poás, Costa Rica

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    Se presentan los resultados obtenidos del estudio de las emanaciones difusas de H2 en el volcán Poás, Costa Rica. Este estudio ha implicado la realización de tres campañas en los años 2000, 2001 y 2002, conla finalidad de investigar la distribución espacial de la concentración de H2 en el gas del suelo y evaluar la des-gasificación difusa de esta especie como una herramienta geoquímica para el programa de vigilancia volcánicadel Poás. Las concentraciones de H2 en el gas del suelo medidas presentan un amplio rango de valores que vandesde 0,4 a 7059 ppmV. La mayor parte del área de estudio reflejó contenidos relativamente bajos de H2 en elgas del suelo, mientras que las concentraciones más altas se midieron en el interior del cráter principal durantelos años 2001 y 2002. Desde la campaña del 2001 se ha observado un aumento relativo del contenido de H2 enel gas del suelo del interior del cráter principal, coincidiendo en el tiempo con un incremento de la actividad fumarólica y de la temperatura en los suelos. Estos resultados pueden indicar la existencia de cambios en el sistema volcánico-hidrotermal del Poás, por lo que el monitoreo de las emanaciones difusas de H2 podría ser útilpara mejorar el programa de vigilancia volcánica. We report the results of the study of diffuse H2 emission from Poás volcano, Costa Rica. Three surveys were carried out in 2000, 2001 and 2002, to investigate soil H2 distribution in and around Poás summit crater and to evaluate diffuse H2 emission as a potential geochemical tool for the Poás volcano monitoring program. Soil H2 contents showed a wide range of concentrations from 0.4 to 7,059 ppmV. Most of the study area showed low levels of H2 in the soil atmosphere, and the highest values of soil gas H2 were just observed inside the summit crater of Poás volcano for the 2001 and 2002 surveys. These surface geochemical changes coincide with an increase of the fumarolic activity as well as soil temperature rose inside the crater during this study.The results here reported suggest changes in the Poás volcanic-hydrothermal system, therefore monitoring diffuse H2 emission could be useful for the volcanic surveillance of Poás volcano.

    Development of a citrus genome-wide EST collection and cDNA microarray as resources for genomic studies

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    A functional genomics project has been initiated to approach the molecular characterization of the main biological and agronomical traits of citrus. As a key part of this project, a citrus EST collection has been generated from 25 cDNA libraries covering different tissues, developmental stages and stress conditions. The collection includes a total of 22,635 high-quality ESTs, grouped in 11,836 putative unigenes, which represent at least one third of the estimated number of genes in the citrus genome. Functional annotation of unigenes which have Arabidopsis orthologues (68% of all unigenes) revealed gene representation in every major functional category, suggesting that a genome-wide EST collection was obtained. A Citrus clementina Hort. ex Tan. cv. Clemenules genomic library, that will contribute to further characterization of relevant genes, has also been constructed. To initiate the analysis of citrus transcriptome, we have developed a cDNA microarray containing 12,672 probes corresponding to 6875 putative unigenes of the collection. Technical characterization of the microarray showed high intra- and inter-array reproducibility, as well as a good range of sensitivity. We have also validated gene expression data achieved with this microarray through an independent technique such as RNA gel blot analysis

    COVID-19 in hospitalized HIV-positive and HIV-negative patients : A matched study

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    CatedresObjectives: We compared the characteristics and clinical outcomes of hospitalized individuals with COVID-19 with [people with HIV (PWH)] and without (non-PWH) HIV co-infection in Spain during the first wave of the pandemic. Methods: This was a retrospective matched cohort study. People with HIV were identified by reviewing clinical records and laboratory registries of 10 922 patients in active-follow-up within the Spanish HIV Research Network (CoRIS) up to 30 June 2020. Each hospitalized PWH was matched with five non-PWH of the same age and sex randomly selected from COVID-19@Spain, a multicentre cohort of 4035 patients hospitalized with confirmed COVID-19. The main outcome was all-cause in-hospital mortality. Results: Forty-five PWH with PCR-confirmed COVID-19 were identified in CoRIS, 21 of whom were hospitalized. A total of 105 age/sex-matched controls were selected from the COVID-19@Spain cohort. The median age in both groups was 53 (Q1-Q3, 46-56) years, and 90.5% were men. In PWH, 19.1% were injecting drug users, 95.2% were on antiretroviral therapy, 94.4% had HIV-RNA < 50 copies/mL, and the median (Q1-Q3) CD4 count was 595 (349-798) cells/μL. No statistically significant differences were found between PWH and non-PWH in number of comorbidities, presenting signs and symptoms, laboratory parameters, radiology findings and severity scores on admission. Corticosteroids were administered to 33.3% and 27.4% of PWH and non-PWH, respectively (P = 0.580). Deaths during admission were documented in two (9.5%) PWH and 12 (11.4%) non-PWH (P = 0.800). Conclusions: Our findings suggest that well-controlled HIV infection does not modify the clinical presentation or worsen clinical outcomes of COVID-19 hospitalization
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