75 research outputs found

    Characterizing temporary hydrological regimes at a European scale

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    Monthly duration curves have been constructed from climate data across Europe to help address the relative frequency of ecologically critical low flow stages in temporary rivers, when flow persists only in disconnected pools in the river bed. The hydrological model is 5 based on a partitioning of precipitation to estimate water available for evapotranspiration and plant growth and for residual runoff. The duration curve for monthly flows has then been analysed to give an estimate of bankfull flow based on recurrence interval. The corresponding frequency for pools is then based on the ratio of bank full discharge to pool flow, arguing from observed ratios of cross-sectional areas at flood 10 and low flows to estimate pool flow as 0.1% of bankfull flow, and so estimate the frequency of the pool conditions that constrain survival of river-dwelling arthropods and fish. The methodology has been applied across Europe at 15 km resolution, and can equally be applied under future climatic scenarios

    QUANTIFILERÂźTRIO DNA method performance in a collection of ancient samples

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    Trabalho científico apresentado sob a forma de Poster no evento 9th ISABS Conference on Forensic Anthropologic Genetics and Mayo Clinicm Bol, Island of Brac, Croacia, 2015During the past few years significant progress has been made in solving technical challenges associated with STR profiling including the ability to analyze degraded DNA and low amounts of DNA. The result of these changes is that useful STR profiles can now be obtained from previously untypeable forensic DNA samples. Analysis of DNA from ancient material represents an important role in molecular anthropology, although there are many limitations concerning low DNA quantity and/or degraded DNA, and/or PCR inhibitors. These factors can make it difficult to decide whether to continue with STR analysis, which STR panel to use and how much DNA to add to PCR reaction. With all these constraints, DNA quantification represents an important tool to decide which method will follow in order to improve workflow and have good results in less time-consuming. The Quantifiler¼ Trio DNA method provides a quality index (QI) to detect the presence of degraded DNA along with PCR inhibitors.This guide allows the selection of the optimal short tandem repeat (STR) analysis chemistry (autosomal, or miniSTR) and streamlines the workflow while increasing downstream analysis success rates. In order to compare DNA quality from different extraction methods, samples from 46 exhumed Middle Ages individuals were extracted with modified phenol-chloroform method and also PrepFiler Express BTAℱ method. DNA was quantified with Quantifiler¼ Trio DNA Quantification in an Applied Biosystems¼ 7500 Real-Time PCR System. Results were analyzed and allow us to point Quantifiler¼ Trio method as an important tool in pre-STR typing methods in ancient samplesN/

    Astrobiologically Interesting Stars within 10 parsecs of the Sun

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    The existence of life based on carbon chemistry and water oceans relies upon planetary properties, chiefly climate stability, and stellar properties, such as mass, age, metallicity and Galactic orbits. The latter can be well constrained with present knowledge. We present a detailed, up-to-date compilation of the atmospheric parameters, chemical composition, multiplicity and degree of chromospheric activity for the astrobiologically interesting solar-type stars within 10 parsecs of the Sun. We determine their state of evolution, masses, ages and space velocities, and produce an optimized list of candidates that merit serious scientific consideration by the future space-based interferometry probes aimed at directly detecting Earth-sized extrasolar planets and seeking spectroscopic infrared biomarkers as evidence of photosynthetic life. The initially selected stars number 33 solar-type within the population of 182 stars (excluding late M-dwarfs) closer than 10 pc. A comprehensive and detailed data compilation for these objects is still essentially lacking: a considerable amount of recent data has so far gone unexplored in this context. We present 13 objects as the nearest "biostars", after eliminating multiple stars, young, chromospherically active, hard X-ray emitting stars, and low metallicity objects. Three of these "biostars", HD 1581, 109358 and 115617, closely reproduce most of the solar properties and are considered as premier targets. We show that approximately 7% of the nearby stars are optimally interesting targets for exobiology.Comment: 36 pages, recommended for publication in Astrobiolog

    Isoscaling in dissipative projectile breakup

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    Dynamical breakup of projectile-like fragments (PLF) following dissipative reactions of Ca-48 projectiles with Sn-112 and Sn-124 is shown to exhibit "isoscaling" regularities that can be understood in terms of phase space governed by ground state masses. Ambiguities in isoscaling parameters obscure information on nuclear symmetry energy at subnormal densities
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