48 research outputs found

    False vacuum decay in a brane world cosmological model

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    The false vacuum decay in a brane world model is studied in this work. We investigate the vacuum decay via the Coleman-de Luccia instanton, derive explicit approximative expressions for the Coleman-de Luccia instanton which is close to a Hawking-Moss instanton and compare the results with those already obtained within Einstein's theory of relativity.Comment: minor changes done, references added, version to appear in GR

    Cosmology of a brane radiating gravitons into the extra dimension

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    We study in a self-consistent way the impact of the emission of bulk gravitons on the (homogeneous) cosmology of a three-brane embedded in a five-dimensional spacetime. In the low energy regime, we recover the well known result that the bulk affects the Friedmann equation only via a radiation-like term \C/a^4, called dark or Weyl radiation. By contrast, in the high energy regime, we find that the Weyl parameter \C is no longer constant but instead grows very rapidly as \C\propto a^4. As a consequence, the value of \C today is not a free parameter as usually considered but is a fixed number, which, generically, depends only on the number of relativistic degrees of freedom at the high/low energy transition. Our estimated amount of Weyl radiation satisfies the present nucleosynthesis bounds.Comment: 12 page

    Reconstruction of the equation of state for the cyclic universes in homogeneous and isotropic cosmology

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    We study the cosmological evolutions of the equation of state (EoS) for the universe in the homogeneous and isotropic Friedmann-Lema\^{i}tre-Robertson-Walker (FLRW) space-time. In particular, we reconstruct the cyclic universes by using the Weierstrass and Jacobian elliptic functions. It is explicitly illustrated that in several models the universe always stays in the non-phantom (quintessence) phase, whereas there also exist models in which the crossing of the phantom divide can be realized in the reconstructed cyclic universes.Comment: 29 pages, 8 figures, version accepted for publication in Central European Journal of Physic

    Updating the Food-Based Dietary Guidelines for the Spanish Population: The Spanish Society of Community Nutrition (SENC) Proposal

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    Diet-related risk factors and physical inactivity are among the leading risk factors for disability and are responsible for a large proportion of the burden of chronic non-communicable diseases. Food-based dietary guidelines (FBDGs) are useful tools for nutrition policies and public health strategies to promote healthier eating and physical activity. In this paper, we discuss the process followed in developing the dietary guidelines for the Spanish population by the Spanish Society of Community Nutrition (SENC) and further explain the collaboration with primary healthcare practitioners as presented in the context of the NUTRIMAD 2018 international congress of SENC. From a health in all policies approach, SENC convened a group of experts in nutrition and public health to review the evidence on diet-health, nutrient intake and food consumption in the Spanish population, as well as food preparation, determinants and impact of diet on environmental sustainability. The collaborative group drafted the document and designed the graphic icon, which was then subject to a consultation process, discussion, and qualitative evaluation. Next, a collaborative group was established to plan a dissemination strategy, involving delegates from all the primary healthcare scientific societies in Spain. A product of this collaboration was the release of an attractive, easy-to-understand publication

    Characterization of Histone Genes from the Bivalve Lucina Pectinata

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    Lucina pectinata is a clam that lives in sulfide-rich environments and houses intracellular sulfide-oxidizing endosymbionts. To identify new Lucina pectinata proteins, we produced libraries for genome and transcriptome sequencing and assembled them de novo. We searched for histone-like sequences using the Lucina pectinata histone H3 partial nucleotide sequence against our previously described genome assembly to obtain the complete coding region and identify H3 coding sequences from mollusk sequences in Genbank. Solen marginatus histone nucleotide sequences were used as query sequences using the genome and transcriptome assemblies to identify the Lucina pectinata H1, H2A, H2B and H4 genes and mRNAs and obtained the complete coding regions of the five histone genes by RT-PCR combined with automated Sanger DNA sequencing. The amino acid sequence conservation between the Lucina pectinata and Solen marginatus histones was: 77%, 93%, 83%, 96% and 97% for H1, H2A, H2B, H3 and H4, respectively. As expected, the H3 and H4 proteins were the most conserved and the H1 proteins were most similar to H1′s from aquatic organisms like Crassostrea gigas, Aplysia californica, Mytilus trossulus and Biomphalaria glabrata. The Lucina pectinata draft genome and transcriptome assemblies, obtained by semiconductor sequencing, were adequate for identification of conserved proteins as evidenced by our results for the histone genes

    A low-cost, sustainable, second generation system for surveillance of people living with HIV in Spain: 10-year trends in behavioural and clinical indicators, 2002 to 2011.

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    A second-generation surveillance system of people infected with human immunodeficiency virus (HIV) has been implemented in Spain. Behavioural and clinical data were collected between 2002 and 2011 through an annual one-day, cross-sectional survey in public hospitals, including all in- and outpatients receiving HIVrelated care on the survey day. Mean age increased over time (from 38.7 years in 2002 to 43.8 years in 2011) and 68.4% of the 7,205 subjects were male. The proportion of migrants increased from 6.1% to 15.9%, while people who inject or used to inject drugs (PWID and Ex-PWID) decreased and men who have sex with men (MSM) and heterosexuals increased. Unprotected intercourse at last sex increased among MSM and PWID/Ex-PWID. Patients receiving antiretroviral treatment increased significantly from 76.0% to 88.2% as did those with CD4 T-cell counts ≥350 (from 48.2% to 66.9%) and viral copies <200 (from 47.0% to 85.2%). HIV-infected people with hepatitis C virus RNA decreased from 36.0% in 2004 to 29.9% in 2011, while those with HBsAg remained stable at around 4.4%. Implementation of a low-cost, sustainable system for second-generation surveillance in people living with HIV is feasible. In Spain, the information obtained has helped to define and refine public health policy and document treatment effectiveness.The authors are grateful to all patients and clinical staff who have participated in the survey, for their kind collaboration, to Anastasia Pharris for critical review of the manuscript, and to Kathy Fitch for the English reviewS
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