824 research outputs found

    Actividad molusquicida de extractos acuosos vegetales sobre el caracol manzana pomacea canaliculata

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    En el Ecuador, entre el 40 y 48% de la producción de arroz se pierde a causa del ataque de Pomacea canaliculata, una de las cien especies invasivas más dañinas del mundo que actualmente ha infestado alrededor de 170.000 hectáreas del cultivo en todo el territorio nacional

    Áreas potenciales para plantaciones de Agave angustifolia Haw en Guerrero, México

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    Objective: To determine optimum and suboptimal areas for the establishment of plantations of Agave angustifolia Haw. in the state of Guerrero. Design/methodology/approach: A collection of 139 specimens of A. angustifolia was carried out, obtaining for each specimen phenotypic, agroclimatic and agroecological data. The information of 30 specimens of herbarium was consulted. Interviews were conducted with the representatives of the state council of mezcal in Guerrero, the company Sanzekan Tinemi and Mezcalli del Sur, to complement the information of the areas. A database was created where the information of each copy was included, as well as the information obtained from the interviews. Criteria for selecting potential areas of A. angustifoliawere defined, after which a Geographic Information Systems (GIS) was constructed, generating mapping areas with agroclimatic and agro potential, wherein the optimal suboptimal and marginal areas for the establishment of A. angustifolia were delineated. For the validation of the information, field visits were made to specific sites to verify the agroecological conditions of the potential areas obtained in this research. Results: There are approximately 1,020,998.27 ha with optimum aptitude and 618,015.87 ha with suboptimal aptitude. Limitations on study/implications: We suggest to incorporate information referring to the physiology, productivity and genetic diversity of the native populations of A. angustifolia. Findings/conclusions: The regions with the highest and suboptimal potential for the plantations of A. angustifolia are Norte, Tierra Caliente and Centro, where the largest production of mezcal in the state occurs.  Objetivo: Determinar áreas optimas y subóptimas para establecer plantaciones de Agave angustifolia Haw. en el estado de Guerrero, México. Diseño/metodología/aproximación: Se recolectaron 139 ejemplares de A. angustifolia, para cada ejemplar se registraron datos fenotípicos, agroclimáticos y agroecológicos. Se consultó la información de 30 ejemplares de herbario; además se entrevistaron a los representantes del Consejo Estatal del Mezcal en Guerrero, la empresa Sanzekan Tinemi y la empresa Mezcalli del Sur, para complementar la información de las áreas. Se generó una base de datos donde se incluyó la información de cada ejemplar, así como la obtenida de entrevistas. Se definieron criterios para la selección de áreas potenciales de A. angustifolia, después de lo cual se construyó un Sistema de Información Geográfica (SIG),generando la cartografía de las áreas con potencial agroclimático y agroecológico, donde se delimitaron las áreas optimas, subóptimas y marginales, para el establecimiento de A. angustifolia. Para la validación de la información, se realizaron visitas de campo a sitios específicos para verificar las condiciones agroecológicas de las áreas potenciales obtenidas en el presente trabajo. Resultados: Los resultados indican que existen aproximadamente 1,020,998.27 ha con aptitud óptima y 618,015.87 ha con aptitud subóptima. Limitaciones del estudio/implicaciones: se sugiere incorporar información referente a la fisiología, productividad y diversidad genética de las poblaciones nativas de A. angustifolia. Hallazgos/conclusiones: Las regiones con mayor potencial optimo y subóptimo para las plantaciones de A. angustifolia son Norte, Tierra Caliente y Centro, donde además se presenta la mayor producción de mezcal en el estado

    The future of isosorbide as a fundamental constituent for polycarbonates and polyurethanes

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    Isosorbide is a biobased compound which could become in the near future an advantageous competitor of petroleum-derived components in the synthesis of polymers of different nature. When the reactivity of isosorbide is not enough, it can be successfully transformed into secondary building blocks, such as isosorbide bis(methyl carbonate), which provides extra functionalities for polymerization reactions with diols or diamines. The present review summarizes the possibilities for isosorbide as a green raw material to be used in the synthesis of polycarbonates and polyurethanes to obtain products of similar or enhanced properties to the commercial equivalents.This paper is a part of the research carried out within the VIPRISCAR project which has received funding from the Bio-Based Industries Joint Undertaking (JU) under the European Union’s Horizon 2020 research and innovation programme under grant agreement No 790440. The JU receives support from the European Union’s Horizon 2020 research and innovation programme and the Bio-Based Industries Consortium

    Current State of Conservation Knowledge on Threatened Amphibian Species in Peru

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    This study documents the current state of conservation knowledge on threatened amphibian species in Peru. Following the International Union for the Conservation of Nature (IUCN) classification system, we considered species in the following categories: Critically Endangered, Endangered, Vulnerable, and Near Threatened. Even though only the first three categories are regarded as threatened by IUCN, we included the fourth category to make comparisons with the list of threatened species issued by the Peruvian government. We used the Global Amphibian Assessment\u27s database and the list issued in Peru for this comparison. We conducted separate field surveys in 17 regions of Peru to evaluate the presence/absence of threatened amphibian species and species that are potentially threatened. We also used the Declining Amphibian Database-DAPTF, to compare our results with previous assessments on population declines, and the World Wildlife Fund\u27s Wildfinder database, to determine in which Neotropical ecoregion each species occurs. We compiled data on 83 species, 44 of which are recognized as threatened by the IUCN and/or the Peruvian government. The remaining 39 species should be re-assessed as they face various threats. A re-evaluation of current estimates is needed as only 8% of all species recorded in Peru are recognized as threatened by the government, whereas the global estimate of threatened species is about 32%. In addition to using IUCN criteria, this re-assessment should follow national guidelines standardized in Peru and be in accordance with the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). Because the habitat of almost 40% of threatened species reported herein still remains unprotected, and data on chytridiomycosis and other threats are lacking for most taxa, it is crucial to develop strategies for habitat conservation and research on disease dynamics in natural populations

    Diets based on virgin olive oil or fish oil but not on sunflower oil prevent age-related alvolar bone resorption by mitochondrial-related mechanisms

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    Background/Objectives: Aging enhances frequency of chronic diseases like cardiovascular diseases or periodontitis. Here we reproduced an age-dependent model of the periodontium, a fully physiological approach to periodontal conditions, to evaluate the impact of dietary fat type on gingival tissue of young (6 months old) and old (24 months old) rats.Methods/Findings: Animals were fed life-long on diets based on monounsaturated fatty acids (MUFA) as virgin olive oil, n-6 polyunsaturated fatty acids (n-6PUFA), as sunflower oil, or n-3PUFA, as fish oil. Age-related alveolar bone loss was higher in n-6PUFA fed rats, probably as a consequence of the ablation of the cell capacity to adapt to aging. Gene expression analysis suggests that MUFA or n-3PUFA allowed mitochondria to maintain an adequate turnover through induction of biogenesis, autophagy and the antioxidant systems, and avoiding mitochondrial electron transport system alterations.Conclusions: The main finding is that the enhanced alveolar bone loss associated to age may be targeted by an appropriate dietary treatment. The mechanisms involved in this phenomenon are related with an ablation of the cell capacity to adapt to aging. Thus, MUFA or n-3PUFA might allow mitochondrial maintaining turnover through biogenesis or autophagy. They might also be able to induce the corresponding antioxidant systems to counteract age-related oxidative stress, and do not inhibit mitochondrial electron transport chain. From the nutritional and clinical point of view, it is noteworthy that the potential treatments to attenuate alveolar bone loss (a feature of periodontal disease) associated to age could be similar to some of the proposed for the prevention and treatment of cardiovascular diseases, a group of pathologies recently associated with age-related periodontitis.This study was supported by I+D grants from the Spanish Ministry of Education and Science (AGL2008-01057) and the Autonomous Government of Andalusia (AGR832)

    Measurement of χ c1 and χ c2 production with s√ = 7 TeV pp collisions at ATLAS

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    The prompt and non-prompt production cross-sections for the χ c1 and χ c2 charmonium states are measured in pp collisions at s√ = 7 TeV with the ATLAS detector at the LHC using 4.5 fb−1 of integrated luminosity. The χ c states are reconstructed through the radiative decay χ c → J/ψγ (with J/ψ → μ + μ −) where photons are reconstructed from γ → e + e − conversions. The production rate of the χ c2 state relative to the χ c1 state is measured for prompt and non-prompt χ c as a function of J/ψ transverse momentum. The prompt χ c cross-sections are combined with existing measurements of prompt J/ψ production to derive the fraction of prompt J/ψ produced in feed-down from χ c decays. The fractions of χ c1 and χ c2 produced in b-hadron decays are also measured

    Measurements of fiducial and differential cross sections for Higgs boson production in the diphoton decay channel at s√=8 TeV with ATLAS

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    Measurements of fiducial and differential cross sections are presented for Higgs boson production in proton-proton collisions at a centre-of-mass energy of s√=8 TeV. The analysis is performed in the H → γγ decay channel using 20.3 fb−1 of data recorded by the ATLAS experiment at the CERN Large Hadron Collider. The signal is extracted using a fit to the diphoton invariant mass spectrum assuming that the width of the resonance is much smaller than the experimental resolution. The signal yields are corrected for the effects of detector inefficiency and resolution. The pp → H → γγ fiducial cross section is measured to be 43.2 ±9.4(stat.) − 2.9 + 3.2 (syst.) ±1.2(lumi)fb for a Higgs boson of mass 125.4GeV decaying to two isolated photons that have transverse momentum greater than 35% and 25% of the diphoton invariant mass and each with absolute pseudorapidity less than 2.37. Four additional fiducial cross sections and two cross-section limits are presented in phase space regions that test the theoretical modelling of different Higgs boson production mechanisms, or are sensitive to physics beyond the Standard Model. Differential cross sections are also presented, as a function of variables related to the diphoton kinematics and the jet activity produced in the Higgs boson events. The observed spectra are statistically limited but broadly in line with the theoretical expectations

    Search for squarks and gluinos in events with isolated leptons, jets and missing transverse momentum at s√=8 TeV with the ATLAS detector

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    The results of a search for supersymmetry in final states containing at least one isolated lepton (electron or muon), jets and large missing transverse momentum with the ATLAS detector at the Large Hadron Collider are reported. The search is based on proton-proton collision data at a centre-of-mass energy s√=8 TeV collected in 2012, corresponding to an integrated luminosity of 20 fb−1. No significant excess above the Standard Model expectation is observed. Limits are set on supersymmetric particle masses for various supersymmetric models. Depending on the model, the search excludes gluino masses up to 1.32 TeV and squark masses up to 840 GeV. Limits are also set on the parameters of a minimal universal extra dimension model, excluding a compactification radius of 1/R c = 950 GeV for a cut-off scale times radius (ΛR c) of approximately 30

    Measurement of the production of a W boson in association with a charm quark in pp collisions at √s = 7 TeV with the ATLAS detector

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    The production of a W boson in association with a single charm quark is studied using 4.6 fb−1 of pp collision data at s√ = 7 TeV collected with the ATLAS detector at the Large Hadron Collider. In events in which a W boson decays to an electron or muon, the charm quark is tagged either by its semileptonic decay to a muon or by the presence of a charmed meson. The integrated and differential cross sections as a function of the pseudorapidity of the lepton from the W-boson decay are measured. Results are compared to the predictions of next-to-leading-order QCD calculations obtained from various parton distribution function parameterisations. The ratio of the strange-to-down sea-quark distributions is determined to be 0.96+0.26−0.30 at Q 2 = 1.9 GeV2, which supports the hypothesis of an SU(3)-symmetric composition of the light-quark sea. Additionally, the cross-section ratio σ(W + +c¯¯)/σ(W − + c) is compared to the predictions obtained using parton distribution function parameterisations with different assumptions about the s−s¯¯¯ quark asymmetry

    Measurement of the top pair production cross section in 8 TeV proton-proton collisions using kinematic information in the lepton plus jets final state with ATLAS

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    A measurement is presented of the ttˉt\bar{t} inclusive production cross-section in pppp collisions at a center-of-mass energy of s=8\sqrt{s}=8 TeV using data collected by the ATLAS detector at the CERN Large Hadron Collider. The measurement was performed in the lepton+jets final state using a data set corresponding to an integrated luminosity of 20.3 fb1^{-1}. The cross-section was obtained using a likelihood discriminant fit and bb-jet identification was used to improve the signal-to-background ratio. The inclusive ttˉt\bar{t} production cross-section was measured to be 260±1(stat.)23+22(syst.)±8(lumi.)±4(beam)260\pm 1{\textrm{(stat.)}} ^{+22}_{-23} {\textrm{(syst.)}}\pm 8{\textrm{(lumi.)}}\pm 4{\mathrm{(beam)}} pb assuming a top-quark mass of 172.5 GeV, in good agreement with the theoretical prediction of 25315+13253^{+13}_{-15} pb. The ttˉ(e,μ)+jetst\bar{t}\to (e,\mu)+{\mathrm{jets}} production cross-section in the fiducial region determined by the detector acceptance is also reported.Comment: Published version, 19 pages plus author list (35 pages total), 3 figures, 2 tables, all figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/TOPQ-2013-06
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