546 research outputs found

    Phylogenetic analysis with morphological characters of the tribe metapterini STÅL, 1859 and taxonomic revision of the genusGhilianella Spinola, 1850 (HEMIPTERA: REDUVIIDAE: EMESINAE)

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    Metapterini Stål, 1859 pertence à Emesinae (Hemiptera: Reduviidae), apresenta ampla distribuição, e morfologicamente se caracteriza pelo conspícuo processo basal da série póstero-ventral do profemur e pela presença de polimorfismo alar. Na tribo há alta proporção de gêneros com espécies micropteras e ápteras. A única hipótese filogenética disponível para a subfamília assumiu Metapterini como monofilético, embora nunca tenha sido formalmente testado com metodos cladísticos. Além disso, conjuntos de dados moleculares não publicados sugerem parafilia do grupo. Ghilianella Spinola, 1850 é o gênero mais diversificado dentro de Metapterini, exclusivamente Neotropical, e com 72 espécies válidas. Morfologicamente se caracteriza pela série anteroventral do profemur composta por processos espiniformes misturas com setas simples, e genitália do macho simétrica, entre outros caracteres. Os objetivos desta tese são: 1) Testar o monofiletismo de Metapterini usando caracteres morfológicos numa análise cladística; 2) explorar a informatividade filogenética de caracteres morfológicos aqui propostos; 3) avaliar as relações filogenéticas entre os gêneros de Metapterini; 4) hipotetizar as relações filogenéticas entre os gêneros Ghilianella, Ghinallelia e Liaghinella, taxonomicamente problemáticos, para ajudar as suas delimitações e parentesco; e 5) apresentar a revisão taxonômica de Ghilianella explorando novos caracteres morfológicos para ajudar a delimitar as espécies.The assassin bug tribe Metapterini belongs to the subfamily Emesinae (Hemiptera: Reduviidae). Morphologically, it is characterized by the conspicuous basal process of the postero ventral series in the foreleg and the presence of the wing polymorphism, with high proportion of genera with micropterous and apterous species. The only available phylogenetic hypothesis for the subfamily assumed that Metapterini is monophyletic, although it has never been formally tested. In addition, unpublished molecular data sets suggest that this group might be paraphyletic. The genus Ghilianella Spinola, 1850 is the most diversified genus of the Metapterini, exclusively Neotropical with approximately 72 species. Morphologically, it is characterized by having the anteroventral and posteroventral setal series on the two distal thirds of the fore femur, the anteroventral series composed by spines and setae and not interrupted in the base, conspicuous posteroventral process located far from the base of the article, both process of the fore femur to the apical extreme end with acute dentiform process, symmetric phallus, among other characters. The goals of this study are to: 1) evaluate the monophyly of the tribe Metapterini with morphological characters; 2) explore novel morphological characters that may be informative for the phylogenetic analysis; 3) assess the phylogenetic relationships among the genera of Metapterini; 4) resolve the phylogenetic relationships among taxonomically problematic genera Ghilianella, Ghinallelia, and Liaghinella; and 5) undertake the taxonomic revision of the large genus Ghilianella exploring novel morphological characters to help delimit the species

    Revisitando el género de chinches emboscadoras Neoanthylla Kormilev, 1951 (Reduviidae, Phymatinae)

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    Neoanthylla (Kormilev, 1951) es un género Neotropical de Phymatinae con tres especies válidas: Neoanthylla bucki (Kormilev), Neoanthylla horvathi (Handlirsch) y Neoanthylla peruviana Kormilev. Morfológicamente se caracteriza por el profémur alargado y ovalado con la superficie cuticular lisa y brillante; las procoxas largas y subiguales al mesofémur; la carina prosternal larga, alcanzando el margen anterior del mesosternum; y el abdomen entero posteriormente. Las especies de Neoanthylla están escasamente documentadas en la literatura y las estructuras genitales son desconocidas. Además, las especies brasileñas (N. bucki y N. horvathi) son conocidas sólo por hembras. Aquí, se revisa Neoanthylla, se actualizan las diagnosis de las especies válidas, se brindan imágenes de los holotipos de N. horvathi y N. peruviana, y se describe por primera vez el macho de N. horvathi, incluyendo los caracteres genitales.Neoanthylla (Kormilev, 1951) is a Neotropical genus of Phymatinae with three valid species: Neoanthylla bucki (Kormilev), Neoanthylla horvathi (Handlirsch), and Neoanthylla peruviana Kormilev. Morphologically, it is characterized by the elongated and oval profemur with the cuticular surface smooth and shiny; the procoxa long and subequal to the mesofemur; the prosternal carina long, reaching the anterior margin of the mesosternum; and the abdomen posteriorly entire. Neoanthylla species are scarcely documented in the literature, and the genital structures are unknown. In addition, the Brazilian species (N. bucki and N. horvathi) are known only by female specimens. Here, Neoanthylla is revisited, the diagnoses of the valid species are improved, images of the holotypes of N. horvathi and N. peruviana are provided, and the male of N. horvathi is described for the first time, including genital characters.Fil: Castro Huertas, Ana Valentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Entomología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Varela, Pablo Sebastian. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Entomología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Melo, María Cecilia. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Entomología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

    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

    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 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

    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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    Measurement of t(t)over-bar normalised multi-differential cross sections in pp collisions at root s=13 TeV, and simultaneous determination of the strong coupling strength, top quark pole mass, and parton distribution functions

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    An embedding technique to determine ττ backgrounds in proton-proton collision data

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    An embedding technique is presented to estimate standard model tau tau backgrounds from data with minimal simulation input. In the data, the muons are removed from reconstructed mu mu events and replaced with simulated tau leptons with the same kinematic properties. In this way, a set of hybrid events is obtained that does not rely on simulation except for the decay of the tau leptons. The challenges in describing the underlying event or the production of associated jets in the simulation are avoided. The technique described in this paper was developed for CMS. Its validation and the inherent uncertainties are also discussed. The demonstration of the performance of the technique is based on a sample of proton-proton collisions collected by CMS in 2017 at root s = 13 TeV corresponding to an integrated luminosity of 41.5 fb(-1).Peer reviewe
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