Geometric Second Order Field Equations for General Tensor Gauge Fields

Higher spin tensor gauge fields have natural gauge-invariant field equations written in terms of generalised curvatures, but these are typically of higher than second order in derivatives. We construct geometric second order field equations and actions for general higher spin boson fields, and first order ones for fermions, which are non-local but which become local on gauge-fixing, or on introducing auxiliary fields. This generalises the results of Francia and Sagnotti to all representations of the Lorentz group.Comment: 34 pages, LaTeX. Reference adde

Horizontal Branch Stars: The Interplay between Observations and Theory, and Insights into the Formation of the Galaxy

We review HB stars in a broad astrophysical context, including both variable and non-variable stars. A reassessment of the Oosterhoff dichotomy is presented, which provides unprecedented detail regarding its origin and systematics. We show that the Oosterhoff dichotomy and the distribution of globular clusters (GCs) in the HB morphology-metallicity plane both exclude, with high statistical significance, the possibility that the Galactic halo may have formed from the accretion of dwarf galaxies resembling present-day Milky Way satellites such as Fornax, Sagittarius, and the LMC. A rediscussion of the second-parameter problem is presented. A technique is proposed to estimate the HB types of extragalactic GCs on the basis of integrated far-UV photometry. The relationship between the absolute V magnitude of the HB at the RR Lyrae level and metallicity, as obtained on the basis of trigonometric parallax measurements for the star RR Lyrae, is also revisited, giving a distance modulus to the LMC of (m-M)_0 = 18.44+/-0.11. RR Lyrae period change rates are studied. Finally, the conductive opacities used in evolutionary calculations of low-mass stars are investigated. [ABRIDGED]Comment: 56 pages, 22 figures. Invited review, to appear in Astrophysics and Space Scienc

Integrative effect of carvedilol and aerobic exercise training therapies on improving cardiac contractility and remodeling in heart failure mice

The use of β-blockers is mandatory for counteracting heart failure (HF)-induced chronic sympathetic hyperactivity, cardiac dysfunction and remodeling. Importantly, aerobic exercise training, an efficient nonpharmacological therapy to HF, also counteracts sympathetic hyperactivity in HF and improves exercise tolerance and cardiac contractility; the latter associated with changes in cardiac Ca2+ handling. This study was undertaken to test whether combined β–blocker and aerobic exercise training would integrate the beneficial effects of isolated therapies on cardiac structure, contractility and cardiomyocyte Ca2+ handling in a genetic model of sympathetic hyperactivity-induced HF (α2A/α2C- adrenergic receptor knockout mice, KO). We used a cohort of 5–7 mo male wild-type (WT) and congenic mice (KO) with C57Bl6/J genetic background randomly assigned into 5 groups: control (WT), saline-treated KO (KOS), exercise trained KO (KOT), carvedilol-treated KO (KOC) and, combined carvedilol-treated and exercise-trained KO (KOCT). Isolated and combined therapies reduced mortality compared with KOS mice. Both KOT and KOCT groups had increased exercise tolerance, while groups receiving carvedilol had increased left ventricular fractional shortening and reduced cardiac collagen volume fraction compared with KOS group. Cellular data confirmed that cardiomyocytes from KOS mice displayed abnormal Ca2+ handling. KOT group had increased intracellular peak of Ca2+ transient and reduced diastolic Ca2+ decay compared with KOS group, while KOC had increased Ca2+ decay compared with KOS group. Notably, combined therapies re-established cardiomyocyte Ca2+ transient paralleled by increased SERCA2 expression and SERCA2:PLN ratio toward WT levels. Aerobic exercise trained increased the phosphorylation of PLN at Ser16 and Thr17 residues in both KOT and KOCT groups, but carvedilol treatment reduced lipid peroxidation in KOC and KOCT groups compared with KOS group. The present findings provide evidence that the combination of carvedilol and aerobic exercise training therapies lead to a better integrative outcome than carvedilol or exercise training used in isolation.© 2013 Vanzelli et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Diarreia em caprinos associada ao consumo de Arrabidaea corallina (Bignoniaceae)

Descreve-se um surto de intoxicação natural por Arrabidaea corallina (Jacq.) Sandw. (fam. Bignoniaceae) em caprinos no Município de Boqueirão, semiárido da Paraíba, durante a estação seca. De um rebanho de 550 caprinos maiores de um ano foram afetados 56 (10%) e morreram 6 (1%), com sinais clínicos de diarreia, aumento dos movimentos ruminais e depressão. Os demais animais se recuperaram após serem retirados da pastagem. O rebanho alimentava-se de pastagem nativa e nesse período dispunham de pouca forragem. Todavia, A. corallina era a única planta invasora que se mantinha verde e existia em grande quantidade. Um caprino afetado foi necropsiado. O intestino delgado apresentava conteúdo liquefeito, fétido e enegrecido e alterações de enterite catarral. Ao exame histológico observou-se enterite aguda, difusa e moderada, ocasionalmente com presença de Eimeria sp. Não foram observadas lesões macroscópicas ou microscópicas significativas em outros órgãos. A doença foi reproduzida experimentalmente em 4 caprinos após administração das folhas frescas de A. corallina em 3-6 doses diárias de 15g por kg de peso animal. Os caprinos apresentaram diarreia 3-4 dias após o início da ingestão e se recuperaram 5-6 dias após o final da administração. Conclui-se que o consumo de A. corallina é responsável pela ocorrência da doença em caprinos a campo. No entanto outras doenças como a infestação parasitária e a desnutrição podem contribuir para causar a morte dos animais. Recomenda-se a retirada de caprinos de áreas invadidas por A. corallina quando, em consequência de estiagem, não houver outra forragem disponível.An outbreak of poisoning by Arrabidaea corallina (Jacq.) Sandw. (Fam. Bignoniaceae) in goats is reported, which occurred in the municipality of Boqueirão, semiarid of Paraíba, during the dry season. In a flock of 550 goats, older than one year of age, 56 (10%) were affected and 6 (1%) died. Clinical signs were diarrhea, increased ruminal movements and depression. The goats recovered after being moved to another paddock. The pasture had low forage availability and large amounts of A. corallina was the only other green plant observed. One goat was necropsied. The gut had liquid, fetid and blackish content, and showed catarrhal enteritis. Histology revealed acute, diffuse and moderate enteritis. Eimeria sp. was also observed. Non significant macroscopic or histological lesions were seen in other tissues. The disease was experimentally reproduced in four goats after the administration of fresh leaves of A. corallina, at 3-6 daily doses of 15g per kg of body weight. The animals showed diarrhea 3-4 days after the beginning of administration and recovered 5-6 days afterwards. It is concluded that the plant is responsible for the outbreak of diarrhea in goats, but parasitic disease or malnutrition can be contributing factors to the animal death. Goats should be withdrawn from paddocks with A. corallina if during the dry seasons no other forage is available