The Evolution of Compact Binary Star Systems

We review the formation and evolution of compact binary stars consisting of white dwarfs (WDs), neutron stars (NSs), and black holes (BHs). Binary NSs and BHs are thought to be the primary astrophysical sources of gravitational waves (GWs) within the frequency band of ground-based detectors, while compact binaries of WDs are important sources of GWs at lower frequencies to be covered by space interferometers (LISA). Major uncertainties in the current understanding of properties of NSs and BHs most relevant to the GW studies are discussed, including the treatment of the natal kicks which compact stellar remnants acquire during the core collapse of massive stars and the common envelope phase of binary evolution. We discuss the coalescence rates of binary NSs and BHs and prospects for their detections, the formation and evolution of binary WDs and their observational manifestations. Special attention is given to AM CVn-stars -- compact binaries in which the Roche lobe is filled by another WD or a low-mass partially degenerate helium-star, as these stars are thought to be the best LISA verification binary GW sources.Comment: 105 pages, 18 figure

Venous gas embolism as a predictive tool for improving CNS decompression safety

A key process in the pathophysiological steps leading to decompression sickness (DCS) is the formation of inert gas bubbles. The adverse effects of decompression are still not fully understood, but it seems reasonable to suggest that the formation of venous gas emboli (VGE) and their effects on the endothelium may be the central mechanism leading to central nervous system (CNS) damage. Hence, VGE might also have impact on the long-term health effects of diving. In the present review, we highlight the findings from our laboratory related to the hypothesis that VGE formation is the main mechanism behind serious decompression injuries. In recent studies, we have determined the impact of VGE on endothelial function in both laboratory animals and in humans. We observed that the damage to the endothelium due to VGE was dose dependent, and that the amount of VGE can be affected both by aerobic exercise and exogenous nitric oxide (NO) intervention prior to a dive. We observed that NO reduced VGE during decompression, and pharmacological blocking of NO production increased VGE formation following a dive. The importance of micro-nuclei for the formation of VGE and how it can be possible to manipulate the formation of VGE are discussed together with the effects of VGE on the organism. In the last part of the review we introduce our thoughts for the future, and how the enigma of DCS should be approached

Novel Approach Identifies SNPs in SLC2A10 and KCNK9 with Evidence for Parent-of-Origin Effect on Body Mass Index

Marja-Liisa Lokki työryhmien Generation Scotland Consortium, LifeLines Cohort Study ja GIANT Consortium jäsenPeer reviewe

A GEOCHEMICAL INVESTIGATION OF CRUDE OILS AND SOURCE ROCKS FROM BIYANG BASIN, CHINA

China has a number of petroliferous lacustrine sedimentary basins of varying salinity and age (mainly Eocene). A geochemical investigation has been undertaken on several oils and source rocks from the Eocene lacustrine Biyang Basin. The distributions of n-alkanes, isoprenoids, steranes, and terpanes have been studied and used to characterize the sedimentary environment of deposition, maturity, biodegradation and undertake possible correlations. The ratios of C30-hopane/gammacerane, 4-methylsteranes/regular steranes, steranes/hopanes, C21 tricyclic/C30 hopane are proposed to be indicative of the depositional environment whereas beta-carotane appears to be a source related indicator. The geochemical data obtained in this study suggest that the major source rocks in the Biyang Basin were deposited in a saline/hypersaline depositional environment

Characterization of Graphite Alteration and Bitumen Genesis in the Cigar Lake Deposit (saskatchewan, Canada)

Bitumens collected in the east zone of the Cigar Lake deposit have been analyzed by C-13 nuclear magnetic resonance, pyrolysis - gas chromatography, Rock-Eval, and C. H, and 0 methods. Carbon and hydrogen isotopic compositions and uranium contents have been determined. Results indicate that the bitumens consist mainly of aromatic structures (F(a) almost-equal-to 60%) and have undergone a late oxidation process. Similarities in carbon isotopic composition (-27.5 part per thousand > deltaC-13 > -28.2 parts per thousand) between barren bitumens (U < 300 ppm) and graphite collected in the basement gneisses, as well as evidence for progressive disorganization of graphite along a basement profile, suggest a genetic relationship between graphite and bitumens from the mineralized areas. The presence of amorphous carbon in pit structures inside graphite flakes close to the unconformity supports this assessment. Significant differences in geochemical and isotopic characteristics of the Cigar Lake barren bitumens and the Cluff Lake mineralized bitumens suggest that there are two possible mechanisms for their formation. Barren ''C-enriched bitumens could have formed directly by hydrogenation of amorphous carbon, whereas mineralized, isotopically light bitumens from Cluff Lake (deltaC-13 almost-equal-to 48 parts per thousand) may result from the polymerization of light hydrocarbons around uraninite grains

Turkey

The Tertiary Thrace Basin located in NW Turkey comprises 9 km of clastic-sedimentary column ranging in age from Early Eocene to Recent in age. Fifteen natural gas and 10 associated condensate samples collected from the I I different gas fields along the NW-SE extending zone of the northern portion of the basin were evaluated on the basis of their chemical and individual C isotopic compositions. For the purpose of the study, the genesis of CH4, thermogenic C2+ gases, and associated condensates were evaluated separately.Methane appears to have 3 origins: Group-1 CH4 is bacteriogenic (Calculated delta(13)C(C1-C) = -61.48%.; Silivri Field) and found in Oligocene reservoirs and mixed with the thermogenic Group-2 CH4. They probably formed in the Upper Oligocene coal and shales deposited in a marshy-swamp environment of fluvio-deltaic settings. Group-2 (delta(13)C(C1-C) = -35.80 parts per thousand; Hamitabat Field) and Group-3 (delta(13)C(1-C) = -49.10 parts per thousand; Degirmenkoy Field) methanes are thermogenic and share the same origin with the Group-2 and Group-3 C2+ gases. The Group-2 C2+ gases include 63% of the gas fields. They are produced from both Eocene (overwhelmingly) and Oligocene reservoirs. These gases were almost certainly generated from isotopically heavy terrestrial kerogen (delta(13)C = -21 parts per thousand) present in the Eocene deltaic Hamitabat shales. The Group-3 C2+ gases, produced from one field, were generated from isotopically light marine kerogen (delta(13)C = -29 parts per thousand). Lower Oligocene Mezardere shales deposited in pro-deltaic settings are believed to be the source of these gases.The bulk and individual n-alkane isotopic relationships between the rock extracts, gases, condensates and oils from the basin differentiated two Groups of condensates, which can be genetically linked to the Group-2 and -3 thermogenic C2+ gases. However, it is crucial to note that condensates do not necessarily correlate to their associated gases.Maturity assessments on the Group-1 and -2 thermogenic gases based on their estimated initial kerogen isotope values (delta(13)C = -21 parts per thousand; -29 parts per thousand) and on the biomarkers present in the associated condensates reveal that all the hydrocarbons including gases, condensates and oils are the products of primary cracking at the early mature st age (R-eq = 0.55-0.81%). It is demonstrated that the open-system source conditions required for such an early-mature hydrocarbon expulsion exist and are supported by fault systems of the basin. (c) 2005 Elsevier Ltd. All rights reserved.C1 Univ Pamukkale, Geol Engn Dept, TR-20070 Denizli, Turkey.Univ Oklahoma, Norman, OK 73019 USA.High Bank House, Tenbury Wells WR15 8JJ, Worcs, England.Turkish Petr Corp, Explorat Grp, Ankara, Turkey