51 research outputs found

    Droplet formation in cold asymmetric nuclear matter in the quark-meson-coupling model

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    The quark-meson-coupling model is used to study droplet formation from the liquid-gas phase transition in cold asymmetric nuclear matter. The critical density and proton fraction for the phase transition are determined in the mean field approximation. Droplet properties are calculated in the Thomas-Fermi approximation. The electromagnetic field is explicitly included and its effects on droplet properties are studied. The results are compared with the ones obtained with the NL1 parametrization of the non-linear Walecka model.Comment: 21 pages, RevTeX including 8 figures in .eps file

    Relativistic Thomas-Fermi description of Sm isotopes at finite temperature

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    The caloric curve (excitation energy per particle as a function of temperature) for finite nuclei is calculated within the non-linear Walecka model for different proton fractions and different parameterizations. The results obtained are compared with published experimental data and other theoretical results. Other properties related with the droplet formation as the surface energy, neutron skin thickness and binding energy per nucleon are also displayed as a function of temperature and their behaviours are discussed. It is shown that the caloric curve is sensitive to the proton fraction and to the Coulomb interaction. At T=0 the droplet properties do not depend on the parameterization used. At finite temperature however, the sensitivity appears.Comment: 24 pages, 5 figures, 9 table

    Induction of cardiac fibulin-4 protects against pressure overload-induced cardiac hypertrophy and heart failure

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    The prevailing view of fibulin-4 deficient mice is that the cardiac phenotype is the result of aortic and/or valvular disease. In the present study, we have tested whether the cardiac phenotype is, at least in part, the consequence of primary cardiac effects of fibulin-4. We have found fibulin-4 expression to be activated throughout the myocardium in wildtype (fibulin-4 +/+) C57Bl/6J;129 Sv mice subjected to transverse aortic constriction (TAC). In contrast, haploinsufficient fibulin-4 +/R mice exposed to severe TAC do not show this increase in myocardial fibulin-4 expression, but display altered physical properties of myocardial tissue. Moreover, TAC-induced cardiac fibrosis, pulmonary congestion, and mortality are aggravated in fibulin-4 +/R mice. In vitro investigations of myocardial tissue show that fibulin-4 deficiency results in cardiomyocyte hypertrophy, and a decreased beating frequency and contractile force. In conclusion, we demonstrate functions for fibulin-4 in cardiac homeostasis and show that reduced fibulin-4 expression drives myocardial disease in response to cardiac pressure overload, independent of aortic valvular pathology. </p

    Applied aspects of pineapple flowering

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    Resposta do abacaxizeiro 'Vitória' a doses de nitrogênio em solos de tabuleiros costeiros da Paraíba

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    Apesar de importantes, são bastante escassas as informações sobre adubação e nutrição mineral de cultivares de abacaxi resistentes à fusariose. O objetivo deste trabalho foi avaliar a resposta do abacaxizeiro 'Vitória', em termos de nutrição mineral, produção e qualidade, à aplicação de doses crescentes de N, em Espodossolo Humilúvico da região de Tabuleiros Costeiros, Estado da Paraíba. O experimento foi conduzido em delineamento experimental de blocos casualizados, com cinco tratamentos, correspondente às doses de 100, 200, 300, 500 e 600 kg ha-1 de N (ureia aos 60, 180 e 270 dias após o plantio), e três repetições. Avaliaram-se o comprimento, a matéria fresca da folha 'D' e os teores de N, P e K nas porções clorofilada e aclorofilada aos 300 e 420 dap; e peso médio, produtividade, atributos físicos (peso, comprimento e diâmetro mediano de infrutescências; peso e comprimento de coroa) e químicos (pH, sólidos solúveis - SS, acidez titulável - AT e relação SS/AT) de infrutescências na colheita. A elevação da dose de N aumentou linearmente os valores de comprimento e matéria fresca da folha 'D'. O aumento das doses promoveu também elevação dos teores de N e diminuição dos de P e K da porção clorofilada aos 300 dap, sem alterar, entretanto, os teores desses nutrientes aos 420 dap. Na porção aclorofilada, a elevação das doses de N aumentou os teores de K aos 320 dap, mas diminuiu-os aos 420 dap. Os valores de peso de infrutescências e de produtividade aumentaram com a elevação das doses de N, estimando-se valores máximos de 1,0 kg e 37,9 t ha-1, com doses de 409,0 e 439,0 kg ha-1 de N, respectivamente. As doses de N não alteraram os atributos de qualidade das infrutescências, as quais se mostraram compatíveis com as características descritas para a cultivar

    Meristemas: fontes de juventude e plasticidade no desenvolvimento vegetal

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    Human eye development is characterized by coordinated expression of fibrillin isoforms

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    Purpose: Mutations in human fibrillin-1 and -2, which are major constituents of tissue microfibrils, can affect multiple ocular components, including the ciliary zonule, lens, drainage apparatus, cornea, and retina. However, the expression pattern of the three human fibrillins and an integral microfibrillar component, MAGP1, during human eye development is not known. Methods: We analyzed sections from human eyes at gestational weeks (GWs) 6, 8, and 11 and at 1 and 3 years of age with antibodies specific for each human fibrillin isoform or MAGP1, using immunofluorescence microscopy. Results: During embryonic development, each fibrillin isoform was detected in vascular structures bridging the ciliary body and the developing lens, hyaloid vasculature, and retina. In addition, they were present in the developing corneal basement membranes and lens capsule. MAGP1 codistributed with the fibrillin isoforms. In contrast, the juvenile zonule was composed of fibrillin-1 microfibrils containing MAGP1, but fibrillin-2 was absent and fibrillin-3 was only sparsely detected. Conclusions: Fibrillin-1, -2, and, unique to humans, fibrillin-3 are found in various ocular structures during human embryonic eye development, whereas fibrillin-1 dominates the postnatal zonule. We speculate that vasculature spanning the ciliary body and lens, which elaborates fibrillin-2 and -3, may provide an initial scaffold for fibrillin assembly and zonule formation. © 2014 The Association for Research in Vision and Ophthalmology, Inc
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