Cosmic Black Holes

Production of high-energy gravitational objects is a common feature of gravitational theories. The primordial universe is a natural setting for the creation of black holes and other nonperturbative gravitational entities. Cosmic black holes can be used to probe physical properties of the very early universe which would usually require the knowledge of the theory of quantum gravity. They may be the only tool to explore thermalisation of the early universe. Whereas the creation of cosmic black holes was active in the past, it seems to be negligible at the present epoch.Comment: 7 pages. Essay submitted to the 2003 Gravity Research Foundation essay competition. Received an honorable mention. Accepted for publication in IJMP

Effects of Increasing Concentrations of Corn Distiller’s Dried Grains with Solubles on Chemical Composition and Nutrients Content of Egg

Four diets were formulated to contain 0, 17, 35 or 50% corn DDGS. A total of 240 54-week-old single-comb White Leghorn laying hens were assigned to one of four dietary treatments and fed for a 24-week experimental period. Two sets of the experimental diets were formulated and each diet was fed for 12 weeks. Chemical composition and nutritional components in egg yolk were measured. Egg yolk from hens fed DDGS-containing diet tended to have higher fat content and lower protein content. Total polyunsaturated fatty acids were significantly increased by DDGS diet. The contents of choline and cholesterol were initially higher in 50% DDGS treatment group, but were not different in the later period, especially during last 4 weeks. Lutein content increased linearly as DDGS level increased. The results indicated that feeding high level of DDGS can increase the content of lutein and polyunsaturated fatty acids in egg yolk, but may not affect the content of cholesterol or choline

Dose-Dependent Changes of Chemical Attributes in Irradiated Sausages

To determine the effects of irradiation on the chemical attributes of sausages, TBARS values, volatile compounds, gas compounds, and hydrocarbons of vacuum-packaged sausages were analyzed during 60 d of refrigerated storage. A sulfur-containing volatile compound (dimethyl disulfide), a gas compound (methane), and radiation-induced hydrocarbons (1-tetradecene, pentadecane, heptadecane, 8-heptadecene, eicosane, 1, 7-hexadecadiene, hexadecane) were mainly detected in irradiated sausages, and the concentrations of the compounds were irradiation dosedependent. Especially methane and a few hydrocarbons were detected only in irradiated sausages and their amounts were dose-dependent. On the other hand, TBARS values, other off-odor volatiles (carbon disulfide, hexanal), and gas compounds (carbon monoxide, carbon dioxide) were found both in irradiated and nonirradiated sausages. Therefore, it is suggested that irradiation-induced hydrocarbons (1-tetradecene, pentadecane, heptadecane, 8-heptadecene, eicosane, 1, 7-hexadecadiene, hexadecane), dimethyl disulfide, and methane can be used as markers for irradiated sausages

Evaluation of Radiation-induced Compounds in Irradiated Raw or Cooked Chicken Meat during Storage

The concentrations of hydrocarbons, 2-alkylcyclobutanones, and sulfur volatiles in irradiated (0, 5 kGy) chicken meats (raw, pre-cooked, and irradiatedcooked) were analyzed after 0 and 6 months of frozen storage (-40°C) under oxygen permeable packaging conditions. Two hydrocarbons [8-heptadecene (C17:1) and 6,9-heptadecadiene (C17:2)], two 2-alkylcyclobutanones [2-dodecylcyclobutanone (DCB) and 2-tetradecylcyclobutanone (TCB)], and dimethyl disulfide were determined as radiation-induced detection markers in the irradiated raw and cooked chicken meats. Although, irradiated-cooked samples produced less hydrocarbons and 2-alkylcyclobutanones than pre-cooked irradiated ones, the amount of individual hydrocarbons or 2-alkylcyclobutanones was still sufficient enough to detectradiation treatment even after 6 months of storage at -40°C. Among sulfur volatiles, only dimethyl disulfide were found in meat after 6 months of storage indicating it has potential to be used an irradiation detection marker for frozen-stored meats under oxygen permeable packaging conditions

Effects of Diet, Packaging and Irradiation on Protein Oxidation, Lipid Oxidation of Raw Broiler Thigh Meat

The effects of dietary treatment, packaging and irradiation singly or in combinations on the oxidative stability of broiler chicken thigh meat were studied. Lipid and protein oxidation of thigh meats from birds fed the diet supplemented with antioxidants (vitamin E + BHA) were significantly lower than those of the control while those from oxidized oil treatment were higher than the control. Vacuum-packaging slowed down while irradiation accelerated both lipid and protein oxidation of thigh meat during storage. Dietary antioxidants (vitamin E + BHA) and irradiation treatments showed stronger effect to lipid oxidation than protein oxidation. Significant correlation between lipid and protein oxidation in meat was foundduring storage. The results indicated that appropriate use of dietary antioxidants in combination with packaging could be effective in minimizing oxidative changes in irradiated raw chicken thigh meat

Impact of Astrophysical Processes on the Gamma-Ray Background from Dark Matter Annihilations

We study the impact of astrophysical processes on the gamma-ray background produced by the annihilation of dark matter particles in cosmological halos, with particular attention to the consequences of the formation of supermassive black holes. In scenarios where these objects form adiabatically from the accretion of matter on small seeds, dark matter is first compressed into very dense “spikes”, then its density progressively decreases due to annihilations and scattering off of stellar cusps. With respect to previous analyses, based on non-evolving halos, the predicted annihilation signal is higher and significantly distorted at low energies, reflecting the large contribution to the total flux from unevolved spikes at high redshifts. The peculiar spectral feature arising from the specific redshift distribution of the signal, would discriminate the proposed scenario from more conventional astrophysical explanations. We discuss how this affects the prospects for detection and demonstrate that the gamma-ray background from DM annihilations might be detectable even in absence of a signal from the Galactic center