227 research outputs found

    Spatio-temporal analysis of maximum and minimum temperatures over Levant region (1987-2017)

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    Ponencia presentada en: XI Congreso de la Asociación Española de Climatología celebrado en Cartagena entre el 17 y el 19 de octubre de 2018.[ES]El objetivo de este estudio es analizar los cambios espaciales y temporales en los promedios anuales y estacionales de las temperaturas máxima y mínima en la región del Levante durante 1987-2017. Estos promedios se calcularon a partir de datos diarios para cada estación y para toda la región de Levante. Las tendencias espaciales y temporales para tres variables se calcularon utilizando la prueba no paramétrica de Mann-Kendall. Además, la diferencia de medias anuales y estacionales entre los dos períodos 1987-2000 y 2001-2011 se evaluó mediante el uso de la prueba U no paramétrica de Mann-Whitney. Durante 1987-2017, la región de Levante fue testigo de un calentamiento significativo en las temperaturas máximas y mínimas anuales de 0.33 y 0.30ºC/década, respectivamente. Además, la primavera mostró una tendencia al calentamiento muy fuerte y significativa en comparación con otras estaciones en 0.53ºC/década para la temperatura máxima y en 0.51ºC/década para la temperatura mínima. La temperatura máxima y mínima anual, de primavera y verano han aumentado significativamente en esta región durante 2001-2017 en comparación con el período 1987-2000. Las tendencias decrecientes mostraron un patrón muy aislado y aleatorio en comparación con las tendencias de calentamiento amplias, intensivas y coherentes en los promedios anuales y estacionales de la temperatura máxima y mínima. Las tasas de calentamiento en Jordania fueron generalmente las más altas.[EN]This study aims to analyze the spatial and temporal variability of the annual and seasonal maximum (Tmax) and minimum (Tmin) temperatures, along with the diurnal temperature range (DTR) over the entire Levant region for the period 1987-2017. The temporal trends for these three variables were calculated at the annual and seasonal scales by using the non-parametric Mann-Kendall test. Furthermore, the difference of the means between the two periods (1987-2000 and 2001-2017) were assessed by using the non-parametric Mann-Whitney U test. During 1987-2017, the Levant region suffered a significant warming for the annual maximum and minimum temperatures around 0.33 and 0.30ºC\decade, respectively. In addition, spring showed very strong and significant warming trend (around 0.53ºC/decade for Tmax and 0.51ºC/decade for Tmin) compared with the other seasons. The annual, spring and summer means of Tmax and Tmin have significantly increased over the Levant region during 2001-2017 compared with the period 1987-2000. Spatially, the decreasing trends showed very isolated and random patterns compared with the broad, intensive and coherent warming trends at annual and seasonal time scales. The warming over Jordan was generally the highest.This work has been financed by the projects P11-RNM-7941 (Junta de Andalucía), CGL2013-48539-R (MINECO-Spain, FEDER) and CGL2017-89836-R (MINECO-Spain, FEDER)

    In Situ Characterization of Follicular Helper CD4 T Cells Using Multiplexed Imaging.

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    Follicular helper CD4 T (Tfh) cells play an essential role in the formation of germinal centers (GCs), where mature B cells proliferate, differentiate, and provide long-term protective humoral responses. Despite the extensive phenotypic characterization and identification of human Tfh cell subsets, their spatial positioning at tissue level is not well understood. Here, we describe a quantitative multiplexed immunofluorescence approach allowing for the comprehensive in situ characterization of Tfh cells in human tonsils and lymph nodes (LNs) from individuals with angioimmunoblastic T-cell lymphoma (AITL). We have developed eight multiplexed panels comprising a spectrum of Tfh cell markers, like PD-1, CXCR5, and ICOS, along with transcription factors (Bcl6, Tbet, GATA3), to assess their expression, frequencies, spatial distribution and co-localization in a quantitative manner. Combined analysis of relevant markers revealed the presence of several Tfh cell subsets at tissue level based on the differential expression of surface receptors, nuclear factors as well as their distinct localization within the follicular areas. Interestingly, we found a considerable amount of tonsillar Tfh cells expressing high levels of the Th2 regulator GATA3. The co-expression of GATA3, CXCR5, and BCL6, points to an important role of GATA3 for the generation of effector human Tfh cells. Furthermore, our data revealed significantly different Tfh cell profile signatures between health and disease. Therefore, our imaging platform generates meaningful information for the in situ characterization of human Tfh cells and could provide the base for future studies aiming to a comprehensive understanding of Tfh cell tissue heterogeneity

    Spatio-temporal analysis for extreme temperature indices over the Levant region

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    The temporal and spatial trends of 16 climate extreme indices based on daily maximum and minimum temperatures during the period 1987-2016 at 28 stations distributed across Israel and Palestine in the Levant region were annually and seasonally analysed. The Man-Kendall test and the Sen's slope estimator were employed for the trend analysis. Results showed that the region has significantly experienced a dominant warming trend for the last three decades, with more intense changes for minimum temperatures than for maximum. At annual scale, maximum values of minimum temperatures exhibited significant increasing trends up to 0.68{\deg}C/decade. Changes detected were more pronounced than those for the absolute extreme temperature indices, with 93 and 89% of stations significantly showed increasing trends in TX90p and TN90p, respectively. The duration and fixed threshold extreme indices confirmed the trend toward a warming, with the 86% of the stations exhibited significant increasing trends in the annual SU25 and TR20. Moreover, 57% of stations showed significant increasing trends in their SU30 index. At seasonal scale, the analysis of trends for extreme temperature indices showed intense and broad significant increasing trends in all absolute extreme temperature indices. In summer, more than 75% of total stations exhibited significant increasing trends for warm days and warm nights. In winter and spring, 71% of the total stations also showed significant increasing trends in SU25 index, whereas the percentage of stations reached 82% in summer and 64% in autumn for significant increasing trends in TR20 index. Finally, the influence of large-scale circulation patterns on temperature extremes was examined. The results highlighted the presence of significant correlations between most of the selected extreme temperature indices and the North Sea-Caspian pattern at annual and seasonal scales

    Supporting Diversity in Science through Social Networking

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    In this Community Page, we learn how a scientific community leverages social networking tools to connect a group of dispersed scientific researchers in Ciencia Puerto Rico; this effort fosters innovative research and educational collaborations and changes the way scientists interact with the public

    Prenatal Nutritional Intervention Reduces Autistic-Like Behavior Rates Among Mthfr-Deficient Mice

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    The causes and contributing factors of autism spectrum disorders (ASD) are poorly understood. One gene associated with increased risk for ASD is methylenetetrahydrofolate-reductase (MTHFR), which encodes a key enzyme in one carbon (C1) metabolism. The MTHFR 677C > T polymorphism reduces the efficiency of methyl group production with possible adverse downstream effects on gene expression. In this study, the effects of prenatal and/or postnatal diets enriched in C1 nutrients on ASD-like behavior were evaluated in Mthfr-deficient mice. Differences in intermediate pathways between the mice with and without ASD-like behaviors were tested. The findings indicate that maternal and offspring Mthfr deficiency increased the risk for an ASD-like phenotype in the offspring. The risk of ASD-like behavior was reduced in Mthfr-deficient mice supplemented with C1 nutrients prenatally. Specifically, among offspring of Mthfr+/- dams, prenatal diet supplementation was protective against ASD-like symptomatic behavior compared to the control diet with an odds ratio of 0.18 (CI:0.035, 0.970). Changes in major C1 metabolites, such as the ratios between betaine/choline and SAM/SAH in the cerebral-cortex, were associated with ASD-like behavior. Symptomatic mice presenting ASD-like behavior showed decreased levels of GABA pathway proteins such as GAD65/67 and VGAT and altered ratios of the glutamate receptor subunits GluR1/GluR2 in males and NR2A/NR2B in females. The altered ratios, in turn, favor receptor subunits with higher sensitivity to neuronal activity. Our study suggests that MTHFR deficiency can increase the risk of ASD-like behavior in mice and that prenatal dietary intervention focused on MTHFR genotypes can reduce the risk of ASD-like behavior

    Aprovechamiento y mejoramiento de un suelo salino mediante el cultivo de pastos forrajeros

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    Soil salinity is one of the factors that limit agricultural production in vast land areas. Worldwide, some 897 million hectares show a certain degree of salinity. In Mexico, 10 % of the irrigated area is considered as affected by salinity and approximately two thirds of this is to be found in the northern part of the country. With the purpose of offering an viable alternative for improving saline soils and their vegetable cover, in the present study the effect of planting ryegrass, Sudangrass and bermuda grass, that can excrete salt and also posses physiological tolerance, was evaluated. Besides, the effect of two pant densities (1 x 106 and 2 x 106 pl ha-1) on soil total soluble salts equilibrium, cations and anions and cations in plants were also assessed. Results obtained showed a clear trend of salt content reduction in soils, as seen in a drop in electrical conductivity in saturated soil extract and also in cation and anion concentration. Bermuda grass caused a greater fall in soil salinity and no significant effects were found for plant density in soil and plant salt balance.La salinidad de los suelos es uno de los factores que limita actualmente la agricultura en grandes extensiones de tierra. A nivel mundial una superficie de aproximadamente 897 millones de hectáreas presenta algún grado de salinidad. En México se considera que un 10 % del área irrigada está afectada por salinidad y de ésta el 64 % se localiza en el norte del país. Con el propósito de plantear una alternativa para el mejoramiento y cobertura vegetal de los suelos salinos, en el presente estudio se evaluó la salinidad en un suelo cultivado con algunas especies como el zacate Sudán, ballico italiano o ryegrass y zacate bermuda, las cuales poseen propiedades excretoras de sal, como un mecanismo fisiológico de tolerancia a este factor. Así mismo, se evaluó el efecto de dos densidades de población de plantas correspondientes a 1 x 106 y 2 x 106 plantas ha-1, respectivamente en el balance de sales solubles totales, cationes y aniones en suelo y cationes en planta. Los resultados del estudio mostraron una clara tendencia de reducción de sales en el suelo por efecto del cultivo de las tres especies, expresada tanto en reducción de la conductividad eléctrica del extracto de saturación del suelo, como en reducción de la concentración de cationes y aniones formadores de sales. El zacate bermuda ocasionó una mayor reducción en la salinidad del suelo y no se observó efecto significativo de la densidad de población de plantas en el balance de sales en suelo y planta
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