1,692 research outputs found

    Gap interpolation by inpainting methods : Application to Ground and Space-based Asteroseismic data

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    In asteroseismology, the observed time series often suffers from incomplete time coverage due to gaps. The presence of periodic gaps may generate spurious peaks in the power spectrum that limit the analysis of the data. Various methods have been developed to deal with gaps in time series data. However, it is still important to improve these methods to be able to extract all the possible information contained in the data. In this paper, we propose a new approach to handle the problem, the so-called inpainting method. This technique, based on a sparsity prior, enables to judiciously fill-in the gaps in the data, preserving the asteroseismic signal, as far as possible. The impact of the observational window function is reduced and the interpretation of the power spectrum is simplified. This method is applied both on ground and space-based data. It appears that the inpainting technique improves the oscillation modes detection and estimation. Additionally, it can be used to study very long time series of many stars because its computation is very fast. For a time series of 50 days of CoRoT-like data, it allows a speed-up factor of 1000, if compared to methods of the same accuracy.Comment: 29 pages, 7 figures, A&A pending final acceptance from edito

    The seesaw mechanism at TeV scale in the 3-3-1 model with right-handed neutrinos

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    We implement the seesaw mechanism in the 3-3-1 model with right-handed neutrinos. This is accomplished by the introduction of a scalar sextet into the model and the spontaneous violation of the lepton number. We identify the Majoron as a singlet under SUL(2)UY(1)SU_L(2)\otimes U_Y(1) symmetry, which makes it safe under the current bounds imposed by electroweak data. The main result of this work is that the seesaw mechanism works already at TeV scale with the outcome that the right-handed neutrino masses lie in the electroweak scale, in the range from MeV to tens of GeV. This window provides a great opportunity to test their appearance at current detectors, though when we contrast our results with some previous analysis concerning detection sensitivity at LHC, we conclude that further work is needed in order to validate this search.Comment: about 13 pages, no figure

    Desempenho de novilhos Simental alimentados com silagem de sorgo, cana-de-açúcar e palhada de arroz tratada ou não com amônia anidra.

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    Avaliou-se o desempenho de novilhos alimentados com dietas contendo palhada de arroz amonizada, palhada de arroz + uréia, cana-de-açúcar + uréia e silagem de sorgo. Utilizaram-se 16 novilhos, Simental PO, com peso vivo médio de 400 kg, distribuídos em delineamento inteiramente casualizado. O experimento teve duração de 88 dias, sendo 15 de adaptação e 61 dias de avaliação, divididos em três períodos de 21 dias. O consumo total de MS, que variou de 7,1 a 10,0 kg/dia, diferiu entre as dietas, registrando-se maiores consumos para os animais que receberam dietas contendo palhada de arroz amonizada e silagem de sorgo, que, por sua vez, não diferiram entre si. A conversão alimentar não diferiu entre as diferentes dietas, registrando-se valor médio de 6,6. Observou-se maior ganho de peso para os animais que receberam palhada de arroz amonizada (1,59 kg/dia) em relação à palhada mais uréia (1,25 kg/dia). O efeito da amonização, melhorando o valor nutritivo da palhada de arroz, resultou em maior consumo voluntário deste volumoso e, conseqüentemente, em maior ganho diário de peso vivo dos animais, em relação à palhada de arroz não-tratada e suplementada com uréia

    MiniBooNE Results and Neutrino Schemes with 2 sterile Neutrinos: Possible Mass Orderings and Observables related to Neutrino Masses

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    The MiniBooNE and LSND experiments are compatible with each other when two sterile neutrinos are added to the three active ones. In this case there are eight possible mass orderings. In two of them both sterile neutrinos are heavier than the three active ones. In the next two scenarios both sterile neutrinos are lighter than the three active ones. The remaining four scenarios have one sterile neutrino heavier and another lighter than the three active ones. We analyze all scenarios with respect to their predictions for mass-related observables. These are the sum of neutrino masses as constrained by cosmological observations, the kinematic mass parameter as measurable in the KATRIN experiment, and the effective mass governing neutrinoless double beta decay. It is investigated how these non-oscillation probes can distinguish between the eight scenarios. Six of the eight possible mass orderings predict positive signals in the KATRIN and future neutrinoless double beta decay experiments. We also remark on scenarios with three sterile neutrinos. In addition we make some comments on the possibility of using decays of high energy astrophysical neutrinos to discriminate between the mass orderings in presence of two sterile neutrinos.Comment: 33 pages, 8 figures. Comments added, to appear in JHE

    Spontaneous breaking of a global symmetry in a 331 model

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    In a 331 model in which the lepton masses arise from a scalar sextet it is possible to break spontaneously a global symmetry implying in a pseudoscalar majoron-like Goldstone boson. This majoron does not mix with any other scalar fields and for this reason it does not couple, at the tree level, neither to the charged leptons nor to the quarks. Moreover, its interaction with neutrinos is diagonal. We also argue that there is a set of the parameters in which that the model can be consistent with the invisible Z^0-width and that heavy neutrinos can decay sufficiently rapid by majoron emission having a lifetime shorter than the age of the universe.Comment: RevTex, 10 pages, one .eps figur

    Transcultural adaptation to the Brazilian Portuguese of the Postpartum Bonding Questionnaire for assessing the postpartum bond between mother and baby

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    The establishment of the bond between mother and baby in the postpartum period is important for ensuring the physical and psychological health of both. This short communication reports the first phase of the cross-cultural translation and adaptation to the Brazilian context of the Postpartum Bonding Questionnaire (PBQ). Four aspects of equivalence between the original scale and the Portuguese version were evaluated: the conceptual, semantic, operational and item equivalences. Literature review, the study of PBQ history, translation, expert evaluation, back-translation and pretests involving 30 mothers with children aging up to 7 months using a primary healthcare unit were conducted. Each step demonstrated the need for adjustments, which were made during the adaptation process. At the end of the study, a version of PBQ in Brazilian Portuguese equivalent to the original one was obtained, offering promise for national studies on the mother-baby bond, and its influence on health, and for use in health services

    Metabolic fate of glutamine in lymphocytes, macrophages and neutrophils

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    Eric Newsholmes laboratory was the first to show glutamine utilization by lymphocytes and macrophages. Recently, we have found that neutrophils also utilize glutamine. This amino acid has been shown to play a role in lymphocyte proliferation, cytokine production by lymphocytes and macrophages and phagocytosis and superoxide production by macrophages and neutrophils. Knowledge of the metabolic fate of glutamine in these cells is important for the understanding of the role and function of this amino acid in the maintenance of the proliferative, phagocytic and secretory capacities of these cells. Glutamine and glucose are poorly oxidized by these cells and might produce important precursors for DNA, RNA, protein and lipid synthesis. The high rate of glutamine utilization and its importance in such cells have raised the question as to the source of this glutamine, which, according to current evidence, appears to be muscle

    Morphological traits and type of dairy goats registered in Brazil from 1976 to 2009.

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    Abstract: Data from 2439 goats of the Saanen, Alpine, Anglo Nubian and Toggenburg breeds recorded from 1976 to 2009 by the Association of Goats and Sheep Breeders of Minas Gerais were used in principal component analysis. After consistency of data, six morphological variables (thorax perimeter, body length, withers height, height, width and length of the rump) and 12 variables related to breed standard score and fitness (breed characteristic, head, palette and topline, feet and legs, dairy type, body capacity, udder, rear and front ligament, udder texture, teat and final score) were analyzed. Based on the magnitude of the eigenvalue (lower than 0.7), eleven variables considered redundant were discarded, resulting in reduced costs of technician labor to evaluate the animals. Maintenance of records on height, length, rump width, breed characteristic, dairy type, front ligament and udder texture is recommended
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