561 research outputs found

    Diet of Engystomops pustulosus (Anura: Leptodactylidae) from Colombia and current knowledge of its dietary

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    Investigamos la dieta de Engystomops pustulosus de una población del valle medio del río Magdalena, incluyendo una evaluación del efecto del tamaño del cuerpo y de la cabeza sobre el número y volumen de presas. Presentamos el estado actual de conocimiento sobre la dieta de E. pustulosus a partir de información publicada más nuestros datos. Encontramos un total de 400 presas representando dos phyla, Arthropoda y Mollusca; siete órdenes y nueve familias de invertebrados. Los artrópodos, principalmente insectos, fueron las presas más frecuentes en la dieta. Entre los artrópodos, Acari e Isoptera fueron numéricamente dominantes. No se observaron efectos del tamaño del cuerpo y la cabeza sobre el número y volumen de presas. La literatura publicada sobre la dieta de E. pustulosus incluyó 66 taxones presas, entre los que Isoptera, Acari y Formicidae fueron los grupos más comunes, lo que sugiere una especialización en la dieta. Las presas consumidas por E. pustulosus varían entre localidades; Blattodea, Orthoptera y Thysanoptera, son únicos en algunas localidades. Estudios más detallados de la disponibilidad de presas y dietas asociadas a los cambios en el uso del suelo en mas localidades geográficas contribuirá a una mejor comprensión de las interacciones depredador-presa en estos entornos antropogénicos.Investigamos a dieta de Engystomops pustulosus de uma população do vale médio do rio Magdalena, incluindo uma avaliação do efeito do tamanho do corpo e da cabeça sobre o número e o volume das presas. Apresentamos o estado atual do conhecimento sobre a dieta de E. pustulosus com base em informações publicadas e em nossos próprios dados. Encontramos um total de 400 itens alimentares representando os filos Arthropoda e Mollusca; sete ordens e nove famílias de invertebrados. Artrópodes, principalmente insetos, foram os itens mais frequentes na dieta. Entre os artrópodes, Acari e Isoptera foram numericamente dominantes. Não foram observados efeitos do tamanho do corpo e da cabeça sobre o número e o volume de presas. A literatura publicada sobre a dieta de E. pustulosus incluiu 66 táxons, entre os quais Isoptera, Acari e Formicidae foram os grupos mais comuns, sugerindo especialização na dieta. Os itens consumidos variaram entre as localidades; Blattodea, Orthoptera e Thysanoptera foram exclusivos de algumas localidades. Estudos mais detalhados da disponibilidade de presas e dietas associadas a mudanças no uso do solo em mais localidades geográficas contribuirão para uma melhor compreensão das interações predador-presanesses ambientes antropogênicos.We investigated the diet of Engystomops pustulosus from a population in the Middle Magdalena River valley, including an evaluation of theeffect of body and head size on prey number and volume. We present the current state of knowledge of the diet of E. pustulosus from published information in addition to our data. We found a total of 400 prey items representing two phyla, Arthropoda and Mollusca; seven orders and nine families were detected. Arthropods, mainly insects, were the most frequent prey in the diet. Among arthropods, Acari and Isoptera were numerically dominant. We did not observe effects of body and head size on prey number and volume. The published literature of the diet of E. pustulosus included 66 prey items, among which Isoptera (termites), Acari, and Formicidae were the most common groups, suggesting dietary specialization. Prey items consumed by E. pustulosus varied among different localities; Blattodea, Orthoptera, and Thysanoptera were unique at certain localities. Further study of prey availability and diets associated with land-use changes across majorgeographic localities will contribute to a better understanding of the predator-prey interactions in these anthropogenic environments

    Patrimonio cultural : Contextos en transición: pedagogía, cultura y economía sustentable en comunidades americanas

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    El presente documento es una recopilación de experiencias que fueron parte del I Encuentro Internacional de Patrimonio Cultural celebrado en la Corporación Universitaria Minuto de Dios – UNIMINUTO en septiembre del 2019; así como de otros aportes de investigadores colombianos a la comprensión de temas relacionados con la tradición, la cultura, la memoria y el ecosistema natural en el cual como humanos nos desenvolvemos. Los aportes tienen origen en reflexiones de diferentes países desde Argentina hasta Canadá y cumple con el propósito de realizar un diálogo multidisciplinar de los aspectos que componen el patrimonio cultural en el continente americano

    Patrimonio cultural : Contextos en transición: pedagogía, cultura y economía sustentable en comunidades americanas

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    El presente documento es una recopilación de experiencias que fueron parte del I Encuentro Internacional de Patrimonio Cultural celebrado en la Corporación Universitaria Minuto de Dios – UNIMINUTO en septiembre del 2019; así como de otros aportes de investigadores colombianos a la comprensión de temas relacionados con la tradición, la cultura, la memoria y el ecosistema natural en el cual como humanos nos desenvolvemos. Los aportes tienen origen en reflexiones de diferentes países desde Argentina hasta Canadá y cumple con el propósito de realizar un diálogo multidisciplinar de los aspectos que componen el patrimonio cultural en el continente americano

    Supplement: "Localization and broadband follow-up of the gravitational-wave transient GW150914" (2016, ApJL, 826, L13)

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    This Supplement provides supporting material for Abbott et al. (2016a). We briefly summarize past electromagnetic (EM) follow-up efforts as well as the organization and policy of the current EM follow-up program. We compare the four probability sky maps produced for the gravitational-wave transient GW150914, and provide additional details of the EM follow-up observations that were performed in the different bands

    Optimasi Portofolio Resiko Menggunakan Model Markowitz MVO Dikaitkan dengan Keterbatasan Manusia dalam Memprediksi Masa Depan dalam Perspektif Al-Qur`an

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    Risk portfolio on modern finance has become increasingly technical, requiring the use of sophisticated mathematical tools in both research and practice. Since companies cannot insure themselves completely against risk, as human incompetence in predicting the future precisely that written in Al-Quran surah Luqman verse 34, they have to manage it to yield an optimal portfolio. The objective here is to minimize the variance among all portfolios, or alternatively, to maximize expected return among all portfolios that has at least a certain expected return. Furthermore, this study focuses on optimizing risk portfolio so called Markowitz MVO (Mean-Variance Optimization). Some theoretical frameworks for analysis are arithmetic mean, geometric mean, variance, covariance, linear programming, and quadratic programming. Moreover, finding a minimum variance portfolio produces a convex quadratic programming, that is minimizing the objective function ðð¥with constraintsð ð 𥠥 ðandð´ð¥ = ð. The outcome of this research is the solution of optimal risk portofolio in some investments that could be finished smoothly using MATLAB R2007b software together with its graphic analysis

    Search for heavy resonances decaying to two Higgs bosons in final states containing four b quarks

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    A search is presented for narrow heavy resonances X decaying into pairs of Higgs bosons (H) in proton-proton collisions collected by the CMS experiment at the LHC at root s = 8 TeV. The data correspond to an integrated luminosity of 19.7 fb(-1). The search considers HH resonances with masses between 1 and 3 TeV, having final states of two b quark pairs. Each Higgs boson is produced with large momentum, and the hadronization products of the pair of b quarks can usually be reconstructed as single large jets. The background from multijet and t (t) over bar events is significantly reduced by applying requirements related to the flavor of the jet, its mass, and its substructure. The signal would be identified as a peak on top of the dijet invariant mass spectrum of the remaining background events. No evidence is observed for such a signal. Upper limits obtained at 95 confidence level for the product of the production cross section and branching fraction sigma(gg -> X) B(X -> HH -> b (b) over barb (b) over bar) range from 10 to 1.5 fb for the mass of X from 1.15 to 2.0 TeV, significantly extending previous searches. For a warped extra dimension theory with amass scale Lambda(R) = 1 TeV, the data exclude radion scalar masses between 1.15 and 1.55 TeV

    Measurement of the top quark forward-backward production asymmetry and the anomalous chromoelectric and chromomagnetic moments in pp collisions at √s = 13 TeV

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    Abstract The parton-level top quark (t) forward-backward asymmetry and the anomalous chromoelectric (d̂ t) and chromomagnetic (μ̂ t) moments have been measured using LHC pp collisions at a center-of-mass energy of 13 TeV, collected in the CMS detector in a data sample corresponding to an integrated luminosity of 35.9 fb−1. The linearized variable AFB(1) is used to approximate the asymmetry. Candidate t t ¯ events decaying to a muon or electron and jets in final states with low and high Lorentz boosts are selected and reconstructed using a fit of the kinematic distributions of the decay products to those expected for t t ¯ final states. The values found for the parameters are AFB(1)=0.048−0.087+0.095(stat)−0.029+0.020(syst),μ̂t=−0.024−0.009+0.013(stat)−0.011+0.016(syst), and a limit is placed on the magnitude of | d̂ t| < 0.03 at 95% confidence level. [Figure not available: see fulltext.

    Search for Physics beyond the Standard Model in Events with Overlapping Photons and Jets

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    Results are reported from a search for new particles that decay into a photon and two gluons, in events with jets. Novel jet substructure techniques are developed that allow photons to be identified in an environment densely populated with hadrons. The analyzed proton-proton collision data were collected by the CMS experiment at the LHC, in 2016 at root s = 13 TeV, and correspond to an integrated luminosity of 35.9 fb(-1). The spectra of total transverse hadronic energy of candidate events are examined for deviations from the standard model predictions. No statistically significant excess is observed over the expected background. The first cross section limits on new physics processes resulting in such events are set. The results are interpreted as upper limits on the rate of gluino pair production, utilizing a simplified stealth supersymmetry model. The excluded gluino masses extend up to 1.7 TeV, for a neutralino mass of 200 GeV and exceed previous mass constraints set by analyses targeting events with isolated photons.Peer reviewe

    Search for supersymmetry in events with one lepton and multiple jets in proton-proton collisions at root s=13 TeV

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    Measurement of the top quark mass using charged particles in pp collisions at root s=8 TeV

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