1,749 research outputs found

    Una nueva especie de Arachis (Fabaceae) de Mato Grosso, Brasil, afín a A. matiensis

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    In the original description of Arachis matiensis, two isolated populations, from the municipality of Cáceres, Mato Grosso State, Brazil, were listed as possibly representing a different species, but the analysis of additional materials, and further morphological study were considered necessary to reach a decision in that regard. New herbarium and germplasm collections in the area, additional morphological studies, and inter- and intraspecific crossing results now support the description of A. jacobinensis, a new species of the taxonomic section ProcumbentesEn la descripción original de Arachis matiensis, dos poblaciones brasileñas aisladas, del municipio de Cáceres, estado de Mato Grosso, Brasil, se destacaron como posiblemente pertenecientes a una especie distinta pero se consideró que era necesario realizar análisis de más materiales y estudios morfológicos adicionales para alcanzar una decisión en ese respeto. Nuevas colecciones de herbario y germoplasma en el área, estudios morfológicos complementarios y resultados de cruzamientos inter- e intraespecíficos sustentan ahora la descripción de A. jacobinensis, una nueva especie de la sección taxonómica Procumbente

    Assessing the Sensitivity of Different Life Stages for Sexual Disruption in Roach (Rutilus rutilus) Exposed to Effluents from Wastewater Treatment Works

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    Surveys of U.K. rivers have shown a high incidence of sexual disruption in populations of wild roach (Rutilus rutilus) living downstream from wastewater treatment works (WwTW), and the degree of intersex (gonads containing both male and female structural characteristics) has been correlated with the concentration of effluent in those rivers. In this study, we investigated feminized responses to two estrogenic WwTWs in roach exposed for periods during life stages of germ cell division (early life and the postspawning period). Roach were exposed as embryos from fertilization up to 300 days posthatch (dph; to include the period of gonadal sex differentiation) or as postspawning adult males, and including fish that had received previous estrogen exposure, for either 60 or 120 days when the annual event of germ cell proliferation occurs. Both effluents induced vitellogenin synthesis in both life stages studied, and the magnitude of the vitellogenic responses paralleled the effluent content of steroid estrogens. Feminization of the reproductive ducts occurred in male fish in a concentration-dependent manner when the exposure occurred during early life, but we found no effects on the reproductive ducts in adult males. Depuration studies (maintenance of fish in clean water after exposure to WwTW effluent) confirmed that the feminization of the reproductive duct was permanent. We found no evidence of ovotestis development in fish that had no previous estrogen exposure for any of the treatments. In wild adult roach that had previously received exposure to estrogen and were intersex, the degree of intersex increased during the study period, but this was not related to the immediate effluent exposure, suggesting a previously determined programming of ovotestis formation

    Effects of zinc supplementation on cognitive function in healthy middle-aged and older adults: the ZENITH study

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    A randomised double-blind placebo-controlled design was employed to investigate the effects of Zn supplementation on cognitive function in 387 healthy adults aged 55–87 years. Several measures of visual memory, working memory, attention and reaction time were obtained using the Cambridge Automated Neuropsychological Test Battery at baseline and then after 3 and 6 months of 0 (placebo), 15 or 30 mg Zn/d. Younger adults (70 years), and performance improved with practice on some measures. For two out of eight dependent variables, there were significant interactions indicating a beneficial effect (at 3 months only) of both 15 and 30 mg/d on one measure of spatial working memory and a detrimental effect of 15 mg/d on one measure of attention. Further work is required to establish whether these findings generalise to older adults in poorer mental and physical health and with less adequate Zn intake and status than the present sample

    Spatially Explicit Correction of Simulated Urban Air Temperatures Using Crowdsourced Data

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    Urban climate model evaluation often remains limited by a lack of trusted urban weather observations. The increasing density of personal weather sensors (PWSs) make them a potential rich source of data for urban climate studies that address the lack of representative urban weather observations. In our study, we demonstrate that carefully quality-checked PWS data not only improve urban climate models’ evaluation but can also serve for bias correcting their output prior to any urban climate impact studies. After simulating near-surface air temperatures over London and southeast England during the hot summer of 2018 with the Weather Research and Forecasting (WRF) Model and its building Effect parameterization with the building energy model (BEP–BEM) activated, we evaluated the modeled temperatures against 402 urban PWSs and showcased a heterogeneous spatial distribution of the model’s cool bias that was not captured using official weather stations only. This finding indicated a need for spatially explicit urban bias corrections of air temperatures, which we performed using an innovative method using machine learning to predict the models’ biases in each urban grid cell. This bias-correction technique is the first to consider that modeled urban temperatures follow a nonlinear spatially heterogeneous bias that is decorrelated from urban fraction. Our results showed that the bias correction was beneficial to bias correct daily minimum, daily mean, and daily maximum temperatures in the cities. We recommend that urban climate modelers further investigate the use of quality-checked PWSs for model evaluation and derive a framework for bias correction of urban climate simulations that can serve urban climate impact studies. Significance Statement Urban climate simulations are subject to spatially heterogeneous biases in urban air temperatures. Common validation methods using official weather stations do not suffice for detecting these biases. Using a dense set of personal weather sensors in London, we detect these biases before proposing an innovative way to correct them with machine learning techniques. We argue that any urban climate impact study should use such a technique if possible and that urban climate scientists should continue investigating paths to improve our methods

    Cruzabilidad entre Arachis gregoryi (Fabaceae) y especies silvestres de Arachis con distintos genomas

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    Cross-compatibility studies in Arachis L. have brought to light possible new sources of genes for introgression in cultivated peanuts. A total of 32 different crosses were made, using accession V14957 of A. gregoryi C.E. Simpson, Krapov. & Valls as the female parent and Arachis species containing seven distinct genomes as male parents. The 3167 pollinations resulted in 153 confirmed inter and intraspecific hybrids. Viability estimates of paternal pollen by staining (PVS) varied from 46.75 to 99.17%, while the pollen count of the hybrids varied from 0.3 to 43.6%, this highest PVS resulting from an intraspecific combination, which suggests appreciable variability in accessions of A. gregoryi. Viability estimates of paternal pollen by germination (PVG) resulted in consistently lower values for all materials, ranging from 41.91% to 88.00%. Arachis gregoryi is important to expand the available diversity of species associated with the peanut B genome; it has a potential to be incorporated as a parent in crosses that aim to expand the genetic base of peanuts and may be useful for concentrating important genes in pre-breeding lines associated with the B genome.Estudios de compatibilidad cruzada en Arachis L. han sacado a la luz posibles nuevas fuentes de genes para introgresión en el maní cultivado. Se hicieron un total de 32 cruzamientos distintos, utilizando A. gregoryi C.E. Simpson, Krapov. & Valls accesión V14957 como progenitor femenino y especies de Arachis que contienen siete genomas distintos como progenitores masculinos. Las 3167 polinizaciones resultaron en 153 híbridos inter e intraespecíficos confirmados. Estimaciones de viabilidad del polen paternal por tinción (PVS) variaron de 46.75 a 99.17%, mientras que el recuento de polen de los híbridos varió de 0.30 a 43.60 %, ese PVS más alto resultando de una combinación intraespecífica, lo que sugiere variabilidad apreciable entre accesiones de A. gregoryi. Las estimaciones de viabilidad del polen paterno por germinación (PVG) resultaron en valores consistentemente más bajos para todos los materiales, que van desde 41.91% a los 88.00%. Arachis gregoryi es importante para expandir la diversidad disponible de especies asociadas con el genoma B del maní; tiene el potencial de incorporarse como progenitor en cruzamientos que apuntan a la expansión de la base genética del maní y puede ser útil para concentrar genes importantes en líneas de premejoramento asociadas al genoma B

    Cellular Models of Aggregation-Dependent Template-Directed Proteolysis to Characterize Tau Aggregation Inhibitors for Treatment of Alzheimer's Disease

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    Copyright © 2015, The American Society for Biochemistry and Molecular Biology. Acknowledgements-We thank Drs Timo Rager and Rolf Hilfiker (Solvias, Switzerland) for polymorph analyses.Peer reviewedPublisher PD

    Arachis inflata: Una nueva especie de Arachis (Fabaceae) del Genoma B

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    Se han realizado grandes esfuerzos para coleccionar germoplasma del género Arachis en Sudamérica, sin embargo, aún quedan muchas regiones subexploradas. Bajo la hipótesis de que estas tienen poblaciones/especies nuevas y diversas de Arachis, se realizaron nuevas expediciones en Bolivia a partir del año 2000 con el objetivo de incrementar la documentación de la diversidad de este género. Como primer resultado de estas exploraciones, en este trabajo se describe formalmente una nueva especie de la sección Arachis perteneciente al genoma B. Arachis inflata es una especie afín a A. magna y A. ipaënsis, aunque se distingue claramente de ellas, y de todas las demás especies del género, por presentar un tipo de fruto distinto. El mismo presenta epicarpo liso, con aspecto ampollado, debido a la presencia de cámaras de aire en el mesocarpo.Great efforts have been done to collect germplasm of the Arachis genus in South America, however, many regions still remain underexplored. Under the hypothesis that these regions have new and diverse populations/species of Arachis, several expeditions were carried out since 2000 in Bolivia, to increase the documentation of the genus diversity. As a first result of these explorations, a new species of section Arachis with B genome is formally described. Arachis inflata is closely related to A. magna and A. ipaënsis, but it can be clearly distinguished from them, and from any other species of the genus, for having a type of fruit with a completely distinct morphology. The fruit has a smooth epicarp, but shows a bullated aspect, due to the presence of air chambers in the mesocarp.Fil: Seijo, José Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; ArgentinaFil: Atahuachi, Margoth. Universidad Mayor de San Simon Bolivia; BoliviaFil: Simpson, Charles E.. Texas A&M University; Estados UnidosFil: Krapovickas, Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; Argentin

    Arachis inflata: A New B Genome species of Arachis (Fabaceae)

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    Great efforts have been done to collect germplasm of the Arachis genus in South America, however, many regions still remain underexplored. Under the hypothesis that these regions have new and diverse populations/species of Arachis, several expeditions were carried out since 2000 in Bolivia, to increase the documentation of the genus diversity. As a first result of these explorations, a new species of section Arachis with B genome is formally described. Arachis inflata is closely related to A. magna and A. ipaënsis, but it can be clearly distinguished from them, and from any other species of the genus, for having a type of fruit with a completely distinct morphology. The fruit has a smooth epicarp, but shows a bullated aspect, due to the presence of air chambers in the mesocarp

    Las razas de maní de Perú

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    En este estudio sobre maní se diferencian para Perú 47 razas de maní cultivado de las cuales 13 pertenecen a Arachis hypogaeassp. hypogaeavar. hypogaea, 2 a A. hypogaea ssp. hypogaea var. hirsuta, 15 a A. hypogaeassp. fastigiatavar. fastigiata, 15 a A. hypogaeassp. fastigiata var. peruvianay 2 a A. hypogaeassp. fastigiatavar. aecuatoriana. Perú constituye un centro de variación independiente pues sus razas son exclusivas de su territorio, salvo muy pocas excepciones
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