Gravitational Wave Detection by Interferometry (Ground and Space)

Significant progress has been made in recent years on the development of gravitational wave detectors. Sources such as coalescing compact binary systems, neutron stars in low-mass X-ray binaries, stellar collapses and pulsars are all possible candidates for detection. The most promising design of gravitational wave detector uses test masses a long distance apart and freely suspended as pendulums on Earth or in drag-free craft in space. The main theme of this review is a discussion of the mechanical and optical principles used in the various long baseline systems in operation around the world - LIGO (USA), Virgo (Italy/France), TAMA300 and LCGT (Japan), and GEO600 (Germany/U.K.) - and in LISA, a proposed space-borne interferometer. A review of recent science runs from the current generation of ground-based detectors will be discussed, in addition to highlighting the astrophysical results gained thus far. Looking to the future, the major upgrades to LIGO (Advanced LIGO), Virgo (Advanced Virgo), LCGT and GEO600 (GEO-HF) will be completed over the coming years, which will create a network of detectors with significantly improved sensitivity required to detect gravitational waves. Beyond this, the concept and design of possible future "third generation" gravitational wave detectors, such as the Einstein Telescope (ET), will be discussed.Comment: Published in Living Reviews in Relativit

Intermediate-Valence Tautomerism in Decamethylytterbocene Complexes of Methyl-Substituted Bipyridines

Multiconfigurational, intermediate valent ground states are established in several methyl-substituted bipyridine complexes of bispentamethylcyclopentadienylytterbium, Cp*{sub 2} Yb(Me{sub x}-bipy). In contrast to Cp*{sub 2} Yb(bipy) and other substituted-bipy complexes, the nature of both the ground state and the first excited state are altered by changing the position of the methyl or dimethyl substitutions on the bipyridine rings. In particular, certain substitutions result in multiconfigurational, intermediate valent open-shell singlet states in both the ground state and the first excited state. These conclusions are reached after consideration of single-crystal x-ray diffraction (XRD), the temperature dependence of x-ray absorption near-edge structure (XANES), extended x-ray absorption fine-structure (EXAFS), and magnetic susceptibility data, and are supported by CASSCF-MP2 calculations. These results place the various Cp*{sub 2}Yb(bipy) complexes in a new tautomeric class, that is, intermediate-valence tautomers

Effects of Extended-Release Niacin Added to Simvastatin/Ezetimibe on Glucose and Insulin Values in AIM-HIGH

BACKGROUND: Niacin is an anti-dyslipidemic agent that may cause blood sugar elevation in patients with diabetes, but its effects on glucose and insulin values in non-diabetic statin-treated subjects with cardiovascular disease and at high risk for diabetes are less well known. METHODS: This was a pre-specified, intent-to-treat analysis of 3414 participants in the Atherothrombosis Intervention in Metabolic syndrome with low HDL/high triglycerides: Impact on Global Health outcomes trial randomized at 92 centers in the United States and Canada to ERN plus simvastatin/ezetimibe (ERN) or simvastatin/ezetimibe plus placebo (Placebo). Baseline and annual fasting glucose and insulin values were measured. Those experiencing an adverse event indicative of diabetes or starting medications for diabetes were considered to have confirmed diabetes. In addition, non-diabetic subjects with 2 annual follow up glucose measurements were categorized into normal, impaired fasting glucose or newly diagnosed diabetes (presumed or confirmed) states. RESULTS: Compared to placebo, ERN increased annual fasting glucose from baseline to 1 year in both those with normal (7.9±15.8 vs 4.3±10.3 mg/dl; p<0.001) and impaired fasting glucose (4.1±18.7 vs 1.4±14.9 p<0.02) and increased insulin levels. Both effects waned over the next 2 years. There were less consistent effects in those with baseline diabetes. There was an increased risk of progressing from normal to presumed or confirmed impaired fasting glucose (ERN 197/336 cases (58.6%) versus placebo 135/325 cases (41.5%) p<0.001) over time, but no difference in diabetes development in the two treatment groups except in those with normal fasting glucose at baseline. CONCLUSIONS: The addition of ERN to simvastatin/ezetemibe had marginal effects on glycemia in those with diabetes at baseline, and there was a trend toward increased development of new onset diabetes. In addition ERN increased the risk of developing impaired fasting glucose which may have deleterious consequences over time and warrants further study