10,638 research outputs found

    Quantum Anomalies, Running Vacuum and Leptogenesis: an Interplay

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    We discuss a connection between gravitational-wave physics, quantum theory anomalies, right-handed (sterile) neutrinos, (spontaneous) CPT Violation and Leptogenesis, within the framework of string-inspired cosmological models. In particular, we present a scenario, according to which (primordial) gravitational waves induce gravitational anomalies during inflation. This, in turn, results in the existence of an undiluted (at the exit of inflation/beginning of radiation era) bakcground of the Kalb-Ramond (KR) axion of the massless bosonic string gravitational multiplet. The latter may violate spontaneously CP and CPT symmetries, and induce leptogenesis during the radiation-dominated era in models involving right-handed neutrinos. The so-generated lepton asymmetry may then be communicated to the baryon sector by appropriate baryon-minus-lepton-number (B - L)-conserving, but (B + L)-violating, (sphaleron) processes in the Standard Model sector, thus leading to matter dominance over antimatter in the Universe.In the current (approximately de Sitter) era, the KR axion background may provide a source for an axionic dark matter in the Universe, through its mixing with other axions that are abundant in string models. As an interesting byproduct of our analysis, we demonstrate that the anomalies contribute to the vacuum energy density of the Universe terms of 'running-vacuum' type, proportional to the square of the Hubble parameter, H2H^2.Comment: 11 pages Revtex, 1 eps figure incorporated. Based on invited talks by NEM at conferences: Corfu2018, Corfu (Greece) and "HEP2019, NCSR "Demokritos", Athens (Greece). The contents of the current article are partially based on works presented in: arXiv:1905.04685 [hep-th] and arXiv:1209.6387[hep-ph], with which there is partial text opverla

    Ground-state energy and stability limit of small 3He drops

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    Small and stable drops of 3He atoms can only exist above a minimum number of particles, due to the combination of the 3He atom Fermi statistics and its light mass. An accurate estimation of this minimum number using microscopic theory has been difficult due to the inhomogeneous and fermionic nature of these systems. We present a diffusion Monte Carlo calculation of 3He drops with sizes near the minimum in order to determine the stability threshold. The results show that the minimum self-bound drop is formed by N=30 atoms with preferred orbitals for open shells corresponding to maximum value of the spin.Comment: 5 pages, 4 figure

    Feed preference in pigs: Relationship between cereal preference and nutrient composition and digestibility

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    The present work aimed to identify the nutritional characteristics that best explain cereal feed preference in pigs. A total of 25 cereals of known preference (at 60% of inclusion in complete feed) from a previous study were evaluated. The cereals were analyzed for DM, OM, crude fiber, ether extract, CP, GE, digestible starch, and glycemic index. Additionally, for 12 of the cereals, complete feeds (the same composition as those previously used to measure preference) were prepared, analyzed for DM, OM, CP, and starch, and fed to pigs (33 ┬▒ 5.1 kg BW) fitted with ileal T-cannulae to assess the apparent ileal (AID) and total tract digestibility (ATTD) of these nutrients using titanium dioxide as an indigestible marker. The relationships among the different energy and nutrient contents were studied by principal component (PC) analysis, and the correlations between the generated PC scores and cereal preference were analyzed. A correlation between preference and the second PC obtained with data of the 25 cereals was observed (P < 0.01), which indicated that crude fiber (negatively) and digestible starch, OM, and glycemic index (positively) were correlated with feed preference. Statistically significant linear relationships with preference were confirmed for crude fiber, digestible starch, and glycemic index (R = 0.38, 0.36, and 0.23, respectively; P < 0.02). Similarly, the first PC obtained with data of the 12 feeds also correlated with preference (P < 0.01), indicating that the digestible nutrients (positively) and the nondigestible nutrients (negatively) were correlated with preference. Statistically significant relationships with preference were observed for the contents of starch (total, digestible AID, and digestible ATTD: R = 0.62, 0.66, and 0.63, respectively; P < 0.01), AID DM (digestible and nondigestible: R = 0.41 and 0.44, respectively; P < 0.05), ATTD DM (digestible and nondigestible: R = 0.67 and 0.70, respectively; P < 0.01), AID OM (digestible and nondigestible: R = 0.45 and 0.43, respectively; P < 0.05), and ATTD OM (digestible and nondigestible: R = 0.64 and 0.66, respectively;

    Diabetes as an outcome predictor after heart transplantation

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    We aimed to compare post-transplantation morbidity and survival among heart transplant recipients with and without diabetes mellitus. A retrospective review of 141 adult patients submitted to heart transplantation from November 2003 to June 2009 (with a minimum follow-up of one year) was undertaken. The patients were divided into two groups: those with (29%) and those without (71%) pre-transplantation diabetes. Those with diabetes were older (57.6┬▒6.1 vs. 52.3┬▒11.1 years; P=0.020) and had lower creatinine clearance (53.6┬▒15.1 vs. 63.7┬▒22.1; P=0.029). Nine patients died in hospital (6.4%; P=non-significant). No significant differences in lipid profiles (diabetes vs. no diabetes) existed before transplantation or at one year afterwards. Patients with diabetes showed a significant deterioration in their one-year lipid profile (158┬▒43 vs.192┬▒38 mg/dL; P=0.001), although one-year fasting diabetic was lower than before (178┬▒80 vs. 138┬▒45 mg/dL; P=0.016). During the first year, 17 (17%) patients previously free of diabetes developed new-onset diabetes. No significant differences were seen in rejection at one year (14% vs. 20%), infection (31% vs. 33%), new-onset renal dysfunction (8% vs. 14%) or mortality (17% vs. 7%). One-year survival was not significantly different (83% vs. 94%), but there was a significant decrease in the survival of individuals with diabetes at three years (73% vs. 91%; P=0.020). No significant difference was found in one-year survival or in terms of higher morbidity in the heart transplant patients with diabetes, but a longer follow-up showed a significant decrease in survival. Nonetheless, the patients with diabetes benefited significantly from transplantation and should not be excluded from it
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