Foundations of Black Hole Accretion Disk Theory

This review covers the main aspects of black hole accretion disk theory. We begin with the view that one of the main goals of the theory is to better understand the nature of black holes themselves. In this light we discuss how accretion disks might reveal some of the unique signatures of strong gravity: the event horizon, the innermost stable circular orbit, and the ergosphere. We then review, from a first-principles perspective, the physical processes at play in accretion disks. This leads us to the four primary accretion disk models that we review: Polish doughnuts (thick disks), Shakura-Sunyaev (thin) disks, slim disks, and advection-dominated accretion flows (ADAFs). After presenting the models we discuss issues of stability, oscillations, and jets. Following our review of the analytic work, we take a parallel approach in reviewing numerical studies of black hole accretion disks. We finish with a few select applications that highlight particular astrophysical applications: measurements of black hole mass and spin, black hole vs. neutron star accretion disks, black hole accretion disk spectral states, and quasi-periodic oscillations (QPOs).Comment: 91 pages, 23 figures, final published version available at http://www.livingreviews.org/lrr-2013-

Ascites susceptibility as affected by dietary lysine to energy ratios in interaction with broiler genotypes

Male chickens of two pure broiler breeder (S1 and S2) and a broiler cross line Ross 308 (BC) were reared from 0-35 days of age and were fed three dietary regimes with different lysine to apparent metabolizable energy (Lys/AME) ratios. Chickens were subjected to low ambient temperatures to stimulate the development of ascites. The objectives of the experiment was to evaluate effects of different ratios lysine to apparent metabolizable energy (Lys/AME) in diets, at different ages, on following indicators in metabolism for ascites susceptibility: arterial and venous blood gas pressures (paCO(2), pvCO(2), paO(2) and pvO(2)), heat production (Hp), plasma thyroid hormone concentrations (triiodothyronine, T-3 and thyroxine, T-4) and proportional organ weights (lung, liver and heart). Measurements were carried out at 2 and 5 wk of age.status: publishe

Micromineral Source Affects Intestinal Morphology but not Feather Formation in Pigeons

During 7 weeks, two groups of eight pigeons received Zn, Cu, Mn and Se either as inorganic salts or organically bound to investigate the effect of micromineral source on two fast processes in avian metabolism: feather regrowth and intestinal renewal. Increased plasma Zn with reduced hepatic Cu in the organically bound minerals group suggests improved Zn bio-availability with a net antagonistic effect on Cu. Micromineral source did not affect feather regrowth, organ weight or intestinal pH, but the increased villus height with similar crypt depth pointed to increased absorptive surface

Seroprevalence of Pertussis in the Netherlands: Evidence for Increased Circulation of Bordetella pertussis

Background: In many countries, the reported pertussis has increased despite high vaccination coverage. However, accurate determination of the burden of disease is hampered by reporting artifacts. The infection frequency is more reliably estimated on the basis of the prevalence of high IgG concentrations against pertussis toxin (IgG-Ptx). We determined whether the increase in reported pertussis in the last decade is associated with an increase in the number of infections. Methodology/Principal Findings: In a cross-sectional population-based serosurveillance study conducted in 2006-07, from a randomly selected age-stratified sample of 7,903 persons, serum IgG-Ptx concentrations were analyzed using a fluorescent bead-based multiplex immuno assay. In 2006-07, 9.3 % (95%CI 8.5-10.1) of the population above 9 years of age had an IgG-Ptx concentration above 62.5 EU/ml (suggestive for pertussis infection in the past year), which was more than double compared to 1995-96 (4.0%; 95%CI 3.3-4.7). The reported incidence showed a similar increase as the seroprevalence between both periods. Conclusions: Although changes in the vaccination program have reduced pertussis morbidity in childhood, they have not affected the increased infection rate in adolescent and adult pertussis. Indeed, the high circulation of B. pertussis in the latte