6,845 research outputs found

    Energy and volume of vector fields on spherical domains

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    We present in this paper a \boundary version" for theorems about minimality of volume and energy functionals on a spherical domain of threedimensional Euclidean sphere

    Light clusters and the pasta phase

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    The effects of including light clusters in nuclear matter at low densities are investigated within four different parametrizations of relativistic models at finite temperature. Both homogeneous and inhomogeneous matter (pasta phase) are described for neutral nuclear matter with fixed proton fractions. We discuss the effect of the density dependence of the symmetry energy, the temperature and the proton fraction on the non-homogeneous matter forming the inner crust of proto-neutron stars. It is shown that the number of nucleons in the clusters, the cluster proton fraction and the sizes of the Wigner Seitz cell and of the cluster are very sensitive to the density dependence of the symmetry energy.Comment: 14 pages, 14 figures; Accepted for publication in Phys. Rev.

    Characterization of a rare analphoid supernumerary marker chromosome in mosaic

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    Abstract publicado em: Chromosome Research. 2015;23(Suppl 1):67-8. doi:10.1007/s10577-015-9476-6Analphoid supernumerary marker chromosomes (SMCs) are a rare subclass of SMCs C-band-negative and devoid of alpha-satellite DNA. These marker chromosomes cannot be identified unambiguously by conventional banding techniques alone being necessary to apply molecular cytogenetic methods in favour of a detailed characterization. In this work we report an analphoid SMC involving the terminal long arm of chromosome 7, in 9 years-old boy with several dysmorphic features and severe development delay. Cytogenetic analysis revealed a mosaic karyotype with the presence of an extra SMC, de novo, in 20 % of lymphocytes and 73 % of fibroblast cells. FISH analysis with alpha-satellite probes for all chromosomes, whole chromosome painting probe for chromosome 7, and D7S427 and TelVysion 7q probes, allowed establishing the origin of the SMC as an analphoidmarker resulting of an invdup rearrangement of 7q36-qter region. Affimetrix CytoScan HD microarray analysis, redefined the SMC to arr[hg19] 7q35(143696249-159119707)×2~3, which correspond to a gain of 15.42 Mb and encloses 67 OMIM genes, 16 of which are associated to disease. This result, combined with detailed clinical description, will provide an important means for better genotype-phenotype correlation and a more suitable genetic counselling to the patient and his parents, despite the additional difficulty resulting from being a mosaic (expression varies in different tissues). Analphoid SMCs derived from chromosome 7 are very rare, with only three cases reported so far. With this case we hope contribute to a better understanding of this type of chromosome rearrangements which are difficult for genetic counselling

    Instabilities in asymmetric nuclear matter

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    The existence of phase transitions from liquid to gas phases in asymmetric nuclear matter (ANM) is related with the instability regions which are limited by the spinodals. In this work we investigate the instabilities in ANM described within relativistic mean field hadron models, both with constant and density dependent couplings at zero and finite temperatures. In calculating the proton and neutron chemical potentials we have used an expansion in terms of Bessel functions that is convenient at low densities. The role of the isovector scalar δ\delta-meson is also investigated in the framework of relativistic mean field models and density dependent hadronic models. It is shown that the main differences occur at finite temperature and large isospin asymmetry close to the boundary of the instability regions.Comment: 13 pages, 5 figures; to appear in Phys. Rev.

    Quasinormal modes of a massive scalar field nonminimally coupled to gravity in the spacetime of Self-Dual Black Hole

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    In this work, we investigate the quasinormal modes for a massive scalar field with a nonminimal coupling with gravity in the spacetime of a loop quantum black hole, known as the Self-Dual Black Hole. In this way, we have calculated the characteristic frequencies using the 3rd order WKB approach, where we can verify a strong dependence with the mass of scalar field, the parameter of nonminimal coupling with gravity, and parameters of the Loop Quantum Gravity. From our results, we can check that the Self-Dual Black Hole is stable under the scalar perturbations when assuming small values for the parameters. Also, such results tell us that the quasinormal modes assume different values for the cases where the mass of field is null and the nonminimal coupling assumes ξ=0\xi=0 and ξ=1/6\xi=1/6, i.e., a possible breaking of the conformal invariance can be seen in the context of loop quantum black holes.Comment: 15 pages, 2 tables and 8 figures. arXiv admin note: text overlap with arXiv:2005.0220

    Fatores de risco associados à resistência à pesticidas em populações da mosca-dos-chifres.

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    As pragas parasitárias são consideradas um dos principais fatores limitantes à produção animal em todo o mundo e, embora raramente associadas à alta mortalidade, determinam um expressivo impacto econômico em virtude da redução da produtividade e aumentos dos custos de controle. Essa situação tende a ser mais grave em regiões tropicais, como é o caso da maior parte do território brasileiro, onde as condições climáticas favoráveis contribuem para aumentar os problemas decorrentes do parasitismo. Esta publicação buscou levantamento os fatores de risco relacionados à resistência a pesticidas em rebanhos bovídeos.bitstream/item/122468/1/CT-139-moscadoschifres.pd
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