909 research outputs found

    22Ne and 23Na ejecta from intermediate-mass stars: The impact of the new LUNA rate for 22Ne(p,gamma)23Na

    Get PDF
    We investigate the impact of the new LUNA rate for the nuclear reaction 22^{22}Ne(p,γ)23(p,\gamma)^{23}Na on the chemical ejecta of intermediate-mass stars, with particular focus on the thermally-pulsing asymptotic giant branch (TP-AGB) stars that experience hot-bottom burning. To this aim we use the PARSEC and COLIBRI codes to compute the complete evolution, from the pre-main sequence up to the termination of the TP-AGB phase, of a set of stellar models with initial masses in the range 3.0M6.0M3.0\,M_{\odot} - 6.0\,M_{\odot}, and metallicities Zi=0.0005Z_{\rm i}=0.0005, Zi=0.006Z_{\rm i}=0.006, and Zi=0.014Z_{\rm i} = 0.014. We find that the new LUNA measures have much reduced the nuclear uncertainties of the 22^{22}Ne and 23^{23}Na AGB ejecta, which drop from factors of 10\simeq 10 to only a factor of few for the lowest metallicity models. Relying on the most recent estimations for the destruction rate of 23^{23}Na, the uncertainties that still affect the 22^{22}Ne and 23^{23}Na AGB ejecta are mainly dominated by evolutionary aspects (efficiency of mass-loss, third dredge-up, convection). Finally, we discuss how the LUNA results impact on the hypothesis that invokes massive AGB stars as the main agents of the observed O-Na anti-correlation in Galactic globular clusters. We derive quantitative indications on the efficiencies of key physical processes (mass loss, third dredge-up, sodium destruction) in order to simultaneously reproduce both the Na-rich, O-poor extreme of the anti-correlation, and the observational constraints on the CNO abundance. Results for the corresponding chemical ejecta are made publicly available

    Patrones de conductas delictivas y socialización en adolescentes escolares en Brasil

    Get PDF
    Juvenile delinquency in Brazil promotes concern - especially the acts committed by young with more serious (violent) and persistent criminal conduct patterns, which are associated with specific personality traits. The objective of this study is to compare levels of criminal conduct among Brazilian schoolars, grouped according to aspects of socialization personality, from a group of 467 male adolescents. Three clusters are identified from the scores in Agreeableness (S1), Prosociality (S2) and Trustiness (S3). Knowing that the highest scores suggest the greatest social adaptation, Cluster 1, “Low Trustiness” (C1; n = 134) presents the lowest means in Prosociability, besides the lowest means in Trustiness and the greatest means in criminal conducts. The Clúster 2, “High Socialization” (C1; n = 185) presents the best indicators of social adaptation, which is reflected in fewer self-reported criminal behavior. Finally, Clúster 3, “Low Agreeableness” (C3; n = 148), presents a history of conducts similar to the “High Socialization” Clúster, but with the presence of a subgroup with greater self-reported delinquency. The results show variations in the sample studied, in socialization (psychological development), and in themanifestation of criminal conducts.La delincuencia juvenil en Brasil genera preocupación –sobre todo los actos cometidos por jóvenes con patrones deconducta delictivas más graves (violentas) y persistentes, las cualesse asocian a rasgos de personalidad específicos. El objetivo de este estudio es comparar niveles de conducta delictiva en adolescentesescolares brasileños, agrupados según los aspectos depersonalidad de socialización, desde una muestra de 467 adolescentes varones. Se identifican tres clústeres desde las puntuaciones en Amabilidad (S1), Prosocialidad (S2) y Confianza (S3). Sabiendo que las puntuaciones más elevadas sugieren mayor adaptación social, el Clúster 1, “Baja Confianza” (C1; n=134), presenta los promedios más bajos en Prosocialidad, además del más bajo promedio en Confianza y de los mayores promedios en conductas delictivas. El Clúster 2, “Alta Socialización” (C1; n=185) presenta los mejores indicadores de adaptación social, lo que se refleja en menos auto informes de conductas delictivas. Finalmente,el Clúster 3, “Baja Amabilidad” (C3; n=148), presenta un historial de conducta semejante al clúster “Alta Socialización”, pero con algunos indicios de subgrupo con mayor implicación en conductas delictivas. Los resultados denotan variaciones en la muestra estudiada, en las ocialización (desarrollo psicológico), y en la manifestación de conductas delictivas

    Oral chondroitin sulfate and prebiotics for the treatment of canine Inflammatory Bowel Disease: a randomized, controlled clinical trial

    Get PDF
    BACKGROUND Canine inflammatory bowel disease (IBD) is a chronic enteropathy of unknown etiology, although microbiome dysbiosis, genetic susceptibility, and dietary and/or environmental factors are hypothesized to be involved in its pathogenesis. Since some of the current therapies are associated with severe side effects, novel therapeutic modalities are needed. A new oral supplement for long-term management of canine IBD containing chondroitin sulfate (CS) and prebiotics (resistant starch, β-glucans and mannaoligosaccharides) was developed to target intestinal inflammation and oxidative stress, and restore normobiosis, without exhibiting any side effects. This double-blinded, randomized, placebo-controlled trial in dogs with IBD aims to evaluate the effects of 180 days administration of this supplement together with a hydrolyzed diet on clinical signs, intestinal histology, gut microbiota, and serum biomarkers of inflammation and oxidative stress. RESULTS Twenty-seven client-owned biopsy-confirmed IBD dogs were included in the study, switched to the same hydrolyzed diet and classified into one of two groups: supplement and placebo. Initially, there were no significant differences between groups (p > 0.05) for any of the studied parameters. Final data analysis (supplement: n = 9; placebo: n = 10) showed a significant decrease in canine IBD activity index (CIBDAI) score in both groups after treatment (p < 0.001). After treatment, a significant decrease (1.53-fold; p < 0.01) in histologic score was seen only in the supplement group. When groups were compared, the supplement group showed significantly higher serum cholesterol (p < 0.05) and paraoxonase-1 (PON1) levels after 60 days of treatment (p < 0.01), and the placebo group showed significantly reduced serum total antioxidant capacity (TAC) levels after 120 days (p < 0.05). No significant differences were found between groups at any time point for CIBDAI, WSAVA histologic score and fecal microbiota evaluated by PCR-restriction fragment length polymorphism (PCR-RFLP). No side effects were reported in any group. CONCLUSIONS The combined administration of the supplement with hydrolyzed diet over 180 days was safe and induced improvements in selected serum biomarkers, possibly suggesting a reduction in disease activity. This study was likely underpowered, therefore larger studies are warranted in order to demonstrate a supplemental effect to dietary treatment of this supplement on intestinal histology and CIBDAI

    Heredity of type 2 diabetes confers increased susceptibility to oxidative stress and inflammation.

    Get PDF
    INTRODUCTION AND OBJECTIVE: Heredity of type 2 diabetes mellitus (T2DM) is associated with greater risk for developing T2DM. Thus, individuals who have a first-degree relative with T2DM (FDRT) provide a natural model to study factors of susceptibility towards development of T2DM, which are poorly understood. Emerging key players in T2DM pathophysiology such as adverse oxidative stress and inflammatory responses could be among possible mechanisms that predispose FDRTs to develop T2DM. Here, we aimed to examine the role of oxidative stress and inflammatory responses as mediators of this excess risk by studying dynamic postprandial responses in FDRTs. RESEARCH DESIGN AND METHODS: In this open-label case-control study, we recruited normoglycemic men with (n=9) or without (n=9) a family history of T2DM. We assessed plasma glucose, insulin, lipid profile, cytokines and F2-isoprostanes, expression levels of oxidative and inflammatory genes/proteins in circulating mononuclear cells (MNC), myotubes and adipocytes at baseline (fasting state), and after consumption of a carbohydrate-rich liquid meal or insulin stimulation. RESULTS: Postprandial glucose and insulin responses were not different between groups. Expression of oxidant transcription factor NRF2 protein (p<0.05 for myotubes) and gene (pgroup=0.002, ptime×group=0.016), along with its target genes TXNRD1 (pgroup=0.004, ptime×group=0.007), GPX3 (pgroup=0.011, ptime×group=0.019) and SOD-1 (pgroup=0.046 and ptime×group=0.191) was upregulated in FDRT-derived MNC after meal ingestion or insulin stimulation. Synergistically, expression of target genes of inflammatory transcription factor nuclear factor kappa B such as tumor necrosis factor alpha (pgroup=0.001, ptime×group=0.007) was greater in FDRT-derived MNC than in non-FDRT-derived MNC after meal ingestion or insulin stimulation. CONCLUSIONS: Our findings shed light on how heredity of T2DM confers increased susceptibility to oxidative stress and inflammation. This could provide early insights into the underlying mechanisms and future risk of FDRTs for developing T2DM and its associated complications
    corecore