899 research outputs found

    Biologia E Descrição Dos Estágios Imaturos De Gymnetis Rufilateris (illiger, 1800) (coleoptera: Cetoniidae: Cetoniinae)

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    Larvae, pupae and adults of Gymnetis rufilateris (Illiger, 1800) (Coleoptera: Cetoniidae: Cetoniinae) were collected in the municipality of Rochedo, Mato Grosso do Sul State. Studies on biology and morphology were conducted at the Laboratory of Entomology of the Universidade Estadual de Mato Grosso do Sul in Aquidauana, Mato Grosso do Sul, Brazil. Females of couples formed in the laboratory oviposited and allowed the biology studies. The eggs lasted for 15.5 days. Larvae of the 1st, 2nd and 3rd instars lasted 13.5, 30.6 and 113.1 days, respectively. The pupal period lasted 12.8 days. The egg-to-adult period lasts 186.8 days. The larvae fed on decomposing feces of poultry. In the laboratory, adults fed on ripe banana (Musa sp.) (Musaceae). Descriptions of the 3rd larval instar and pupa of G. rufilateris are presented. A key to known larvae of Gymnetis is also included. © 2016, Universidade Estadual de Campinas UNICAMP. All rights reserved.16

    Scarabaeoidea (Insecta : Coleoptera) in the Brazilian Cerrado : current state of knowledge

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    Besouros pertencentes à superfamília Scarabaeoidea ocupam habitats variados, possuem hábitos alimentares diversifi cados, desempenham importante papel ecológico e diversas espécies apresentam importância agrícola. No entanto, estudos com esse grupo na região do Cerrado são escassos. Nesta revisão realizou-se um levantamento dos artigos publicados nos últimos 30 anos a respeito dos Scarabaeoidea no Cerrado. Foram recuperados 64 artigos, realizados em nove unidades da federação, que focavam quatro temas principais espécies praga, aspectos bioecológicos, biodiversidade e importância ecológica, e técnicas e metodologias de coleta de Scarabaeoidea. Os resultados desta revisão indicam que poucos estudos foram realizados com os Scarabaeoidea no Cerrado brasileiro nas últimas décadas frente à importância e diversidade desse grupo de insetos.Beetles belonging to the superfamily Scarabaeoidea occupy different habitats, present feeding habits diversifi ed, play an important ecological role and several species have agricultural importance. However, studies with this group in the Brazilian Cerrado are scarce. In this review we carried out a survey of scientifi c articles published in the past 30 years concerning Scarabaeoidea in the Cerrado. Were found 64 studies in nine Brazilian states. The studies focused on four main topics: pest species, bioecology, biodiversity and ecological importance, techniques and methodologies for collecting Scarabaeoidea. The results of this review indicate that few studies have been conducted with Scarabaeoidea in the Cerrado in recent decades compared to the importance and diversity of this group of insects

    The role of structural evolution on the quantum conductance behavior of gold nanowires during stretching

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    Gold nanowires generated by mechanical stretching have been shown to adopt only three kinds of configurations where their atomic arrangements adjust such that either the [100], [111] or [110] zone axes lie parallel to the elongation direction. We have analyzed the relationship between structural rearrangements and electronic transport behavior during the elongation of Au nanowires for each of the three possibilities. We have used two independent experiments to tackle this problem, high resolution transmission high resolution electron microscopy to observe the atomic structure and a mechanically controlled break junction to measure the transport properties. We have estimated the conductance of nanowires using a theoretical method based on the extended H\"uckel theory that takes into account the atom species and their positions. Aided by these calculations, we have consistently connected both sets of experimental results and modeled the evolution process of gold nanowires whose conductance lies within the first and third conductance quanta. We have also presented evidence that carbon acts as a contaminant, lowering the conductance of one-atom-thick wires.Comment: 10 page

    Prediction of apparent digestibility of hays from natural pastures of the Northeast region of Portugal

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    In the Northeast region of Portugal hays from natural pastures are traditionally used as the main feed during the period of drought and the evaluation of its nutritive value is essential. The aim of this study was to predict the apparent organic matter digestibility (OMD) of 21 hays from natural pastures based on chemical composition, pepsin-cellulase solubility of organic matter (OMS) and in vitro organic matter digestibility. Chemical composition of hays showed a wide range of values and acid detergent lignin (ADL) was the component that presented the highest variation (CV = 18.4%). The OMD varied between 516 and 658 g/kg OM. The best single OMD predictor was OMS (RSD = 2.8%, R2 = 0.52, P<0.001). Using multiple regression to predict OMD, the variables included in the model were OMS and ADL (OMD = 21.51 + 0.94 OMS – 0.83 ADL; RSD = 2.75%; R2 = 0.54; P<0.0001). According to principal component analysis (PCA) hays were divided in 3 groups and the multiple regression established for the larger group of hays (n=10) was: OMD = 4.13 + 0.85 OMS – 1.03 ADL; RSD = 2.13%, R2 = 0.77, P<0.0001. The OMS method was superior to chemical composition and to the in vitro rumen fluid method in predicting OMD of hays from natural pastures. Results from PCA suggested that it may be useful to group these hays according to its chemical composition to accurately predict OMD

    Soil organisms in organic and conventional cropping systems.

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    Apesar do crescente interesse pela agricultura orgânica, são poucas as informações de pesquisa disponíveis sobre o assunto. Assim, num Argissolo Vermelho-Amarelo distrófico foram comparados os efeitos de sistemas de cultivo orgânico e convencional, para as culturas do tomate (Lycopersicum esculentum) e do milho (Zea mays), sobre a comunidade de organismos do solo e suas atividades. As populações de fungos,bactérias e actinomicetos, determinadas pela contagem de colônias em meio de cultura, foram semelhantes para os dois sistemas de produção. A atividade microbiana, avaliada pela evolução de CO2, manteve-se superior no sistema orgânico, sendo que em determinadas avaliações foi o dobro da evolução verificada no sistema convencional. O número de espécimes de minhoca foi praticamente dez vezes maior no sistema orgânico. Não foi observada diferença na taxa de decomposição de matéria orgânica entre os dois sistemas. De modo geral, o número de indivíduos de microartrópodos foi superior no sistema orgânico do que no sistema convencional, refletindo no maior índice de diversidade de Shannon. As maiores populações de insetos foram as da ordem Collembola, enquanto para os ácaros a maior população foi a da superfamília Oribatuloidea. Indivíduos dos grupos Aranae, Chilopoda, Dyplopoda, Pauropoda, Protura e Symphyla foram ocasionalmente coletados e de forma similar entre os sistemas

    Predictive biometrics: A review and analysis of predicting personal characteristics from biometric data

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    Interest in the exploitation of soft biometrics information has continued to develop over the last decade or so. In comparison with traditional biometrics, which focuses principally on person identification, the idea of soft biometrics processing is to study the utilisation of more general information regarding a system user, which is not necessarily unique. There are increasing indications that this type of data will have great value in providing complementary information for user authentication. However, the authors have also seen a growing interest in broadening the predictive capabilities of biometric data, encompassing both easily definable characteristics such as subject age and, most recently, `higher level' characteristics such as emotional or mental states. This study will present a selective review of the predictive capabilities, in the widest sense, of biometric data processing, providing an analysis of the key issues still adequately to be addressed if this concept of predictive biometrics is to be fully exploited in the future

    Some anisotropic universes in the presence of imperfect fluid coupling with spatial curvature

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    We consider Bianchi VI spacetime, which also can be reduced to Bianchi types VI0-V-III-I. We initially consider the most general form of the energy-momentum tensor which yields anisotropic stress and heat flow. We then derive an energy-momentum tensor that couples with the spatial curvature in a way so as to cancel out the terms that arise due to the spatial curvature in the evolution equations of the Einstein field equations. We obtain exact solutions for the universes indefinetly expanding with constant mean deceleration parameter. The solutions are beriefly discussed for each Bianchi type. The dynamics of the models and fluid are examined briefly, and the models that can approach to isotropy are determined. We conclude that even if the observed universe is almost isotropic, this does not necessarily imply the isotropy of the fluid (e.g., dark energy) affecting the evolution of the universe within the context of general relativity.Comment: 17 pages, no figures; to appear in International Journal of Theoretical Physics; in this version (which is more concise) an equation added, some references updated and adde

    The Collective Field Theory of a Singular Supersymmetric Matrix Model

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    The supersymmetric collective field theory with the potential v(x)=ωxηxv'(x)=\omega x-{\eta\over x} is studied, motivated by the matrix model proposed by Jevicki and Yoneya to describe two dimensional string theory in a black hole background. Consistency with supersymmetry enforces a two band solution. A supersymmetric classical configuration is found, and interpreted in terms of the density of zeros of certain Laguerre polynomials. The spectrum of the model is then studied and is seen to correspond to a massless scalar and a majorana fermion. The xx space eigenfunctions are constructed and expressed in terms of Chebyshev polynomials. Higher order interactions are also discussed.Comment: Revtex 8 pages, Submitted to Phys. Rev. D. References and preprint numbers have been adde

    Magnetic phenomena in 5d transition metal nanowires

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    We have carried out fully relativistic full-potential, spin-polarized, all-electron density-functional calculations for straight, monatomic nanowires of the 5d transition and noble metals Os, Ir, Pt and Au. We find that, of these metal nanowires, Os and Pt have mean-field magnetic moments for values of the bond length at equilibrium. In the case of Au and Ir, the wires need to be slightly stretched in order to spin polarize. An analysis of the band structures of the wires indicate that the superparamagnetic state that our calculations suggest will affect the conductance through the wires -- though not by a large amount -- at least in the absence of magnetic domain walls. It should thus lead to a characteristic temperature- and field dependent conductance, and may also cause a significant spin polarization of the transmitted current.Comment: 7 pages, 5 figure

    FITOREGULADORES E GERMINAÇÃO DE SEMENTES DE MARACUJÁ DOCE EM CONDIÇÕES DE LABORATÓRIO

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    The experiment was carried out in Seed Analyze Laboratory of Department of Crop Science of São Paulo State University (UNESP) Botucatu, Brasil. The objective of the experiment was to study the influence of phytoregulators on the germination of Passiflora alata Curtis seeds. Completely randomized blocks, with four replications, 14 treatments of 50 seeds per plot was the experimental design used in the assay. The treatments was composed by applications of GA3, phenylmethil-tetrahydro-pyranil-aminopurine, and ethephon phytoregulators on dosages of 75 and 150 mg L-1 and in combinations of couples of thoses. In the treatments were used two controls, being one with seeds only soaked in distilled water and, the other seeds that did not receive any treatment. The evaluations of initial root emission, percentage of normal seedling, and percentage of hard seeds were avaluated by germination test under 25 °C temperature, during 35 days and after the seeds were remained more 35 days under 20-30 °C temperature. GA3, N-phenylmethyl-9- tetra-hydro-2H-2 pyranil 9H-6 aminopurine, and ethephon phytoregulators, on the 75 and 150 mg L-1 dosages did not favor the process of P.alata seed germinations.O experimento conduzido no Laboratório de Análise de Sementes do Departamento de Produção Vegetal - Setor Agricultura da Faculdade de Ciências Agronômicas do campus de Botucatu - UNESP, teve como objetivo avaliar a influência de fitorreguladores na germinação de sementes de Passiflora alata Curtis. Foram avaliados 14 tratamentos sob o delineamento experimental inteiramente casualizado com 4 repetições de 50 sementes cada. Os tratamentos constaram da aplicação dos fitorreguladores GA3, fenilmetiltetrahidro- piranil-aminopurina e ethephon nas concentrações de 75 e 150 mg.L-1, isolados e combinados com as mesmas dosagens, das sementes embebidas somente em água destilada e das sementes sem qualquer tratamento (testemunha). As avaliações de emissão de radícula, porcentagem de plântulas normais e porcentagem de sementes duras foram avaliadas pelo teste de germinação sob temperatura constante de 25 ºC, por 35 dias e temperatura de 20-30 ºC, por mais 35 dias. Os fitorreguladores GA3, N-fenilmetil-9- Tetra-Hidro-2H-2 piranil 9H-6 amino purina e ethephon, isolados ou em misturas, nas dosagens de 75 e 150 mg.L-1 não favoreceram o processo germinativo de sementes de P. alata
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