1,327 research outputs found

    Effects of climate change and invasive plants on autumn phenology in Massachusetts, USA

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    The timing of biological events in autumn, or autumn phenology, is an important factor in many ecosystem processes. Leaf senescence terminates the growing season, fruiting is important for seed dispersal and frugivorous wildlife, bird migration concludes the breeding season and is a high-mortality event, and insect diapause ends the active season for insects. Climate change and the spread of invasive species have the potential to shift autumn events and ecological processes. However, autumn has been neglected in the phenology literature, and there are many gaps in our knowledge of basic phenological patterns in this season, as well as how they are affected by anthropogenic changes. To address these gaps, I first synthesized the literature on how climate change affects autumn phenology. I found that shifts in autumn phenology can alter reproductive capacities, exacerbate invasions, increase disease transmission rates, reshuffle enemy-prey dynamics, and alter interactions between species. With a focus on autumn interactions between birds and fleshy-fruited plants, my colleagues and I then observed patterns of fruit phenology, using herbarium specimens of 55 species collected across New England, and over 400 species in the living collections of 5 international botanical gardens. Last, I monitored fleshy fruit phenology and abundance at Manomet, a migratory stopover site in coastal Massachusetts, and compared those patterns to seeds identified from landbird fecal samples collected across the autumn season. I found that the sequence of fruiting is moderately consistent from year to year and place to place, and has a significant phylogenetic signal. In wild plants, invasive species fruit, on average, nearly one month later than native species. Considering many landbirds are migrating through New England later over time and in warm years, this suggests birds are increasingly likely to encounter invasive fruits during late-autumn migration. However, bird diets do not reflect the increased availability of invasive fruits in late-autumn; rather, birds show a preference for native fleshy fruits throughout the autumn season. These findings add to our knowledge of how climate change and species invasions affect autumn synchrony, and highlight the importance of native, rather than invasive, fruits as a food source for migratory landbirds.2019-11-07T00:00:00

    Association between oxytocin receptor gene polymorphisms and self-rated 'empathic concern' in schizophrenia

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    The nonapeptide oxytocin (OXT) and its receptor (OXTR) have been implicated in social cognition, empathy, emotion and stress regulation in humans. Previous studies reported associations between OXT and OXTR genetic polymorphisms and risk for disorders characterized by impaired socio-emotional functioning, such as schizophrenia and autism. Here we investigate the influence of two single nucleotide polymorphisms (SNPs) within the OXTR gene on a measure of socio-emotional functioning in schizophrenic patients. OXTR SNPs that were previously investigated in other studies were genotyped in 145 patients diagnosed with schizophrenia according to DSM-IV and 145 healthy controls matched for age and gender. The Interpersonal Reactivity Index (IRI) was used to assess cognitive ('perspective taking'), affective ('empathic concern') and self-related ('personal distress') dimensions of empathy. No group differences in genotype frequencies were observed. MANCOVA revealed a significant main (F [1,282] = 10.464; pGG) with 'empathic concern'. Within the schizophrenia group, linear regression analysis determined OXTR rs2254298 genotype, PANSS negative and general symptom score, and age of disease onset as being significantly associated with 'empathic concern'. OXTR rs2254298 significantly impacted PANSS general psychopathology scores. No associations were found for OXTR rs53576, IRI 'perspective taking' or 'personal distress' ratings. Our preliminary findings support hypotheses about an involvement of OXTR rs2254298 in emotional empathy in schizophrenic and healthy individuals, warranting independent replication

    Optimización de la productividad del agua en zonas regables mediante una herramienta de simulación del sistema hidráulico, agrario y económico

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    Este trabajo presenta una aplicación de la herramienta de simulación CINTEGRAL que permite adaptar el diseño de la red de riego a la realidad agraria local de las zonas regables (meteorología, suelos, cultivos y productividad global). Se estudian las condiciones locales (meteorología, suelos y cultivos) de una zona regable del Valle Medio del Ebro cuya red se ha diseñado de forma estándar. Se analiza el efecto de la variabilidad meteorológica y de diferentes alternativas de gestión del riego sobre la productividad global de la zona. Se discuten las diferencias en producción y productividad global de la zona bajo tres alternativas de gestión del riego: 1) gestión a la demanda, 2) gestión en turnos de riego coincidentes con pisos de presión, y 3) gestión en dos redes independientes. Los resultados obtenidos muestran un efecto claro de la variabilidad meteorológica sobre los ingresos brutos, ingresos netos y la factura eléctrica. La gestión del riego en turnos ajustados en función de la presión requerida permite ahorrar el 22% en la factura eléctrica respecto de la gestión del riego a la demanda. Sin embargo, las producciones se ven afectadas de forma muy notable, reduciendo notablemente la productividad de la zona. Para mantener la productividad con un riego a turnos es necesario realizar modificaciones en el diseño original de la red. Por lo tanto, en esta zona la gestión en turnos coincidentes con pisos de presión no mejora los ingresos netos. La división de la red global en dos sub redes independientes de riego reduce la factura eléctrica en un 20% y además mantiene los niveles de producción, por lo que los ingresos netos se incrementan en un 9%

    DJ-1 interacts with the ectopic ATP-synthase in endothelial cells during acute ischemia and reperfusion

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    Altres ajuts: Ministerio de Ciencia e Innovación. BES Pre-doctoral fellowship (BES-2017-081378).Endothelial cells (ECs) play a central role in ischemia. ATP-Synthase is now recognized to be ectopically expressed in the cell surface of many cell types, with putative roles described in angiogenesis, proliferation, and intracellular pH regulation. DJ-1 is a multifunctional protein, involved in cell protection against ischemia, ischemia-reperfusion (I/R), and oxidative stress, that regulates mitochondrial ATP-synthase. Here we focused on the characterization of the endothelial dynamics of DJ-1, and its implication in the regulation of the ectopic ATP-synthase (ecATP-S) activity, during acute ischemia and I/R in ECs. We found that DJ-1 is secreted from ECs, by a mechanism enhanced in ischemia and I/R. A cleaved form of DJ-1 (DJ-1∆C) was found only in the secretome of ischemic cells. The ecATP-S activity increased following acute ischemia in ECs, coinciding with DJ-1 and DJ-1∆C secretion. The inhibition of DJ-1 expression inhibited the ecATP-S response to ischemia by ∼ 50%, and its exogenous administration maximized the effect, together with an enhanced Akt phosphorylation and angiotube-formation potential at reperfusion. Immunoprecipitation studies showed direct interaction between DJ-1 and the ecATP-S. Altogether suggesting that DJ-1 is actively cleaved and released from ischemic ECs and plays an important role in the regulation of the ecATP-S activity during acute ischemia and reperfusion
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