182 research outputs found

    Dinámica del rendimiento anual de materia seca de una pradera natural bajo tres frecuencias de corte

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    El objetivo del trabajo fue Evaluar la dinámica de rendimiento anual y distribución estacional de la materia seca de una pradera natural bajo tres frecuencias de corte e lo largo de un año.CONACYT – Consejo Nacional de Ciencia y TecnologíaPROCIENCI

    Relative Lempel-Ziv Compression of Suffix Arrays

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    We show that a combination of differential encoding, random sampling, and relative Lempel-Ziv (RLZ) parsing is effective for compressing suffix arrays, while simultaneously allowing very fast decompression of arbitrary suffix array intervals, facilitating pattern matching. The resulting text index, while somewhat larger (5-10x) than the recent r-index of Gagie, Navarro, and Prezza (Proc. SODA ’18)—still provides significant compression, and allows pattern location queries to be answered more than two orders of magnitude faster in practice.Peer reviewe

    Crustal Imbrication in an Alpine Intraplate Mountain Range: A Wide-Angle Cross-Section Across the Spanish-Portuguese Central System

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    Intraplate ranges are topographic features that can occur far from plate boundaries, the expected position of orogens as described in the plate tectonics theory. To understand the lithospheric structure of intraplate ranges, we focused on the Spanish-Portuguese Central System (SPCS), the most outstanding topographic feature in the central Iberian Peninsula. The SPCS is an Alpine range that exhumes Precambrian-Paleozoic rocks and is located at >200 km from the northern border of the Iberian microplate. Here, we provide a P-wave velocity model based on wide-angle seismic reflection/refraction data of the central SPCS (Gredos sector). Our results show: (a) a layered lithosphere characterized by three major interfaces: Conrad, Mohorovicic, and Hales discontinuities, (b) an asymmetry of the crust-mantle boundary under the SPCS, (c) the extent of the Variscan batholith forming the main outcrops of Gredos, and (d) the thinning of the lower crust toward the south. This model suggests that the exhumation of the SPCS basement was driven by a south-vergent thick-skinned thrust system, developed in the southern part of the SPCS and that promoted crustal imbrication and a Mohorovicic discontinuity's offset under the SPCS. Thus, the deformation mechanisms of the crust seem to be controlled by the presence of the late- to post-Variscan granitoids that assimilated the Variscan mid-crustal detachment creating a new rheological boundary. This tectonic structure allowed the formation of Alpine crustal-scale thrust systems that eased coupled deformation of the upper and lower crust, leading to limited underthrusting of both crustal layers.This study has been funded by the Ministry of Science, Innovation and Competitiveness through the Project CIMDEF (CGL2014-56548-P). IP is funded by the Spanish Government and the University of Salamanca (Beatriz Galindo grant BEGAL 18/00090). JA is funded by grant IJC2018-036074-I, funded by MCIN/AEI/10.13039/501100011033. DMP and FGL are also funded by grants CGL2015-71692 (MINECO/ FEDER) and PID2020-118822GB-I00 (MCIN/AEI/10.13039/501100011033).Peer reviewe

    Novel TRPV1 Channel Agonists With Faster and More Potent Analgesic Properties Than Capsaicin

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    Indexación: Scopus.The transient receptor potential vanilloid 1 (TRPV1) ion channel is a member of the family of Transient Receptor Potential (TRP) channels that acts as a molecular detector of noxious signals in primary sensory neurons. Activated by capsaicin, heat, voltage and protons, it is also well known for its desensitization, which led to the medical use of topically applied TRPV1 agonist capsaicin for its long-lasting analgesic effects. Here we report three novel small molecules, which were identified using a Structure-Based Virtual Screening for TRPV1 from the ZINC database. The three compounds were tested using electrophysiological assays, which confirmed their capsaicin-like agonist activity. von Frey filaments were used to measure the analgesic effects of the compounds applied topically on tactile allodynia induced by intra-plantar carrageenan. All compounds had anti-nociceptive activity, but two of them showed faster and longer lasting analgesic effects than capsaicin. The present results suggest that TRPV1 agonists different from capsaicin could be used to develop topical analgesics with faster onset and more potent effects. © Copyright © 2020 Duarte, Cáceres, Sepúlveda, Arriagada, Olivares, Díaz-Franulic, Stehberg and González-Nilo.https://www.frontiersin.org/articles/10.3389/fphar.2020.01040/ful

    Imprints of galaxy evolution on H ii regions Memory of the past uncovered by the CALIFA survey

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    H ii regions in galaxies are the sites of star formation and thus particular places to understand the build-up of stellar mass in the universe. The line ratios of this ionized gas are frequently used to characterize the ionization conditions. We use the Hii regions catalogue from the CALIFA survey (~5000 H ii regions), to explore their distribution across the classical [OIII]/Hbeta vs. [NII]/Halpha diagnostic diagram, and how it depends on the oxygen abundance, ionization parameter, electron density, and dust attenuation. We compared the line ratios with predictions from photoionization models. Finally, we explore the dependences on the properties of the host galaxies, the location within those galaxies and the properties of the underlying stellar population. We found that the location within the BPT diagrams is not totally predicted by photoionization models. Indeed, it depends on the properties of the host galaxies, their galactocentric distances and the properties of the underlying stellar population. These results indicate that although H ii regions are short lived events, they are affected by the total underlying stellar population. One may say that H ii regions keep a memory of the stellar evolution and chemical enrichment that have left an imprint on the both the ionizing stellar population and the ionized gasComment: 18 pages, 8 figures, accepted for publishing in A&

    Insights on the stellar mass-metallicity relation from the CALIFA survey

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    We use spatially and temporally resolved maps of stellar population properties of 300 galaxies from the CALIFA integral field survey to investigate how the stellar metallicity (Z*) relates to the total stellar mass (M*) and the local mass surface density (μ\mu*) in both spheroidal and disk dominated galaxies. The galaxies are shown to follow a clear stellar mass-metallicity relation (MZR) over the whole 109^9 to 1012^{12} M_{\odot} range. This relation is steeper than the one derived from nebular abundances, which is similar to the flatter stellar MZR derived when we consider only young stars. We also find a strong relation between the local values of μ\mu* and Z* (the μ\muZR), betraying the influence of local factors in determining Z*. This shows that both local (μ\mu*-driven) and global (M*-driven) processes are important in determining the metallicity in galaxies. We find that the overall balance between local and global effects varies with the location within a galaxy. In disks, μ\mu* regulates Z*, producing a strong μ\muZR whose amplitude is modulated by M*. In spheroids it is M* who dominates the physics of star formation and chemical enrichment, with μ\mu* playing a minor, secondary role. These findings agree with our previous analysis of the star formation histories of CALIFA galaxies, which showed that mean stellar ages are mainly governed by surface density in galaxy disks and by total mass in spheroids.Comment: 6 pages, 3 figures, accepted for publication in ApJ

    Identification of polymorphic inversions from genotypes

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    Background: Polymorphic inversions are a source of genetic variability with a direct impact on recombination frequencies. Given the difficulty of their experimental study, computational methods have been developed to infer their existence in a large number of individuals using genome-wide data of nucleotide variation. Methods based on haplotype tagging of known inversions attempt to classify individuals as having a normal or inverted allele. Other methods that measure differences between linkage disequilibrium attempt to identify regions with inversions but unable to classify subjects accurately, an essential requirement for association studies. Results: We present a novel method to both identify polymorphic inversions from genome-wide genotype data and classify individuals as containing a normal or inverted allele. Our method, a generalization of a published method for haplotype data [1], utilizes linkage between groups of SNPs to partition a set of individuals into normal and inverted subpopulations. We employ a sliding window scan to identify regions likely to have an inversion, and accumulation of evidence from neighboring SNPs is used to accurately determine the inversion status of each subject. Further, our approach detects inversions directly from genotype data, thus increasing its usability to current genome-wide association studies (GWAS). Conclusions: We demonstrate the accuracy of our method to detect inversions and classify individuals on principled-simulated genotypes, produced by the evolution of an inversion event within a coalescent model [2]. We applied our method to real genotype data from HapMap Phase III to characterize the inversion status of two known inversions within the regions 17q21 and 8p23 across 1184 individuals. Finally, we scan the full genomes of the European Origin (CEU) and Yoruba (YRI) HapMap samples. We find population-based evidence for 9 out of 15 well-established autosomic inversions, and for 52 regions previously predicted by independent experimental methods in ten (9+1) individuals [3,4]. We provide efficient implementations of both genotype and haplotype methods as a unified R package inveRsion

    Morphosedimentary infilling and human settlement of the Tinto-Odiel Estuary (Huelva) during the Mid-Late Holocene.

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    The first human settlements (6000−4000 BP) in the early estuary of the Tinto and Odiel rivers were located in the ancient coastal banks or in the nearby hills. From 4000 years BP onwards, the estuarine sediments started to emerge as sand barriers and chenier plains, prograding towards the mouth. As the littoral strands stabilized morphologically, they are colonized by human settlements in successive periods, the oldest inland (Almendral) and more recent outward (Cascajera). These emerged morphologies were surrounded by muddy tidal flats in the estuary and only the high-energy marine events such as a tsunami or extraordinary storms were able to modify both the landscape and human settlements installed on them. This work also describes the morphodynamicmodel that built the chenier plain of La Cascajera.Ministerio de Ciencia, Innovación y Universidades CGL2010-15810/BTEMinisterio de Ciencia, Innovación y Universidades HAR2012- 36008Junta de Andalucía SEJ-477
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