Search for gravitational waves associated with γ-ray bursts detected by the interplanetary network

We present the results of a search for gravitational waves associated with 223 γ-ray bursts (GRBs) detected by the InterPlanetary Network (IPN) in 2005-2010 during LIGO's fifth and sixth science runs and Virgo's first, second, and third science runs. The IPN satellites provide accurate times of the bursts and sky localizations that vary significantly from degree scale to hundreds of square degrees. We search for both a well-modeled binary coalescence signal, the favored progenitor model for short GRBs, and for generic, unmodeled gravitational wave bursts. Both searches use the event time and sky localization to improve the gravitational wave search sensitivity as compared to corresponding all-time, all-sky searches. We find no evidence of a gravitational wave signal associated with any of the IPN GRBs in the sample, nor do we find evidence for a population of weak gravitational wave signals associated with the GRBs. For all IPN-detected GRBs, for which a sufficient duration of quality gravitational wave data are available, we place lower bounds on the distance to the source in accordance with an optimistic assumption of gravitational wave emission energy of 10(-2)M⊙c(2) at 150 Hz, and find a median of 13 Mpc. For the 27 short-hard GRBs we place 90% confidence exclusion distances to two source models: a binary neutron star coalescence, with a median distance of 12 Mpc, or the coalescence of a neutron star and black hole, with a median distance of 22 Mpc. Finally, we combine this search with previously published results to provide a population statement for GRB searches in first-generation LIGO and Virgo gravitational wave detectors and a resulting examination of prospects for the advanced gravitational wave detectors.

Search for gravitational waves associated with γ-ray bursts detected by the interplanetary network

We present the results of a search for gravitational waves associated with 223 γ-ray bursts (GRBs) detected by the InterPlanetary Network (IPN) in 2005-2010 during LIGO's fifth and sixth science runs and Virgo's first, second, and third science runs. The IPN satellites provide accurate times of the bursts and sky localizations that vary significantly from degree scale to hundreds of square degrees. We search for both a well-modeled binary coalescence signal, the favored progenitor model for short GRBs, and for generic, unmodeled gravitational wave bursts. Both searches use the event time and sky localization to improve the gravitational wave search sensitivity as compared to corresponding all-time, all-sky searches. We find no evidence of a gravitational wave signal associated with any of the IPN GRBs in the sample, nor do we find evidence for a population of weak gravitational wave signals associated with the GRBs. For all IPN-detected GRBs, for which a sufficient duration of quality gravitational wave data are available, we place lower bounds on the distance to the source in accordance with an optimistic assumption of gravitational wave emission energy of 10(-2)M⊙c(2) at 150 Hz, and find a median of 13 Mpc. For the 27 short-hard GRBs we place 90% confidence exclusion distances to two source models: a binary neutron star coalescence, with a median distance of 12 Mpc, or the coalescence of a neutron star and black hole, with a median distance of 22 Mpc. Finally, we combine this search with previously published results to provide a population statement for GRB searches in first-generation LIGO and Virgo gravitational wave detectors and a resulting examination of prospects for the advanced gravitational wave detectors.

Prescription of antidepressants is increased in Danish patients with polycystic ovary syndrome and is associated with hyperandrogenism. A population-based cohort study

OBJECTIVE

Quality of life is impaired in polycystic ovary syndrome (PCOS). In this study, we compared the time to first prescription of antidepressants (ADM) in PCOS vs two control groups.

DESIGN

Register-based cohort study.

PATIENTS

One thousand and one hundred and twenty-four premenopausal women with hirsutism and/or PCOS, premenopausal women with hypertension (HT, n = 301), and age- and sex-matched population controls (controls, n = 4110).

MEASUREMENTS

Prescriptions for ADM on secondary care contacts from regional registers.

RESULTS

The median age at cohort entry in PCOS, HT and controls was 29, 34 and 29 years, respectively. Among PCOS, HT and controls, 227 (20%), 74 (25%) and 633 (15%), respectively, had prescriptions of ADM. The median time to first prescription of ADM in the PCOS, HT and control cohorts was 6·8, 6·6 and 7·2 years, respectively. The adjusted hazard ratio for time to prescription of ADM for HT vs PCOS was 1·36 [95% CI (1·02-1·82)], P = 0·039, and for controls vs PCOS, it was 0·75 [95% CI (0·64-0·88)], P < 0·001. Within patients with PCOS, hyperandrogenism contributed significantly to the model, likelihood ratio test P = 0·009. The adjusted hazard ratio for hyperandrogenism vs no hyperandrogenism was 1·97 (1·12-3·45), P = 0·018.

CONCLUSION

Patients with PCOS had moderately but significantly decreased time to first prescription of ADM compared with age-matched healthy women, whereas patients with HT had the shortest time to prescription. In PCOS, prescription of ADM was associated with the presence of hyperandrogenism.

Acute presentation of craniopharyngioma in children and adults in a Danish national cohort

We aimed to study the occurrence of acute-onset symptoms at initial presentation in a national Danish cohort of patients with childhood- or adult-onset craniopharyngioma, and to investigate potential risk factors for acute presentation. Medical records of 189 consecutive patients (39 children, 150 adults) presenting with craniopharyngioma during the period 1985-2004 were reviewed, and data regarding initial symptoms, neuroimaging results, vision and pituitary function were systematically collected. Acute symptoms preceding hospital admission were noted. Subgroup analyses were based on age, gender and calendar year period. Potential risk factors for acute presentation were analysed through uni- and multivariate analyses. Acute symptoms were reported in 24 (13%) patients. Acute visual symptoms, headache, nausea or vomiting were most frequently reported, and acute symptoms were more frequent among children (28%) than among adults (9%) (P < 0.01). There were no differences according to sex or calendar year period. Hydrocephalus was present in half of childhood cases and one-fifth of adult patients (P < 0.001). Intra-tumour haemorrhage was seen in two cases. Acute symptoms were more frequent among patients with tumours occupying the third ventricle (P < 0.01), radiologic signs of calcification (P < 0.05) or hydrocephalus (P < 0.01). In multivariate analysis, however, only childhood onset (P < 0.05) and calcification (P < 0.05) were independent risk factors for acute presentation. Craniopharyngioma presented with acute symptoms in 13% of patients. Childhood onset and radiologic signs of calcification were independent risk factors for acute presentation. Intra-tumour haemorrhage was rare.

Attributions and self-efficacy for physical activity in multiple sclerosis

Self-efficacy is an important predictor of health-related physical activity in multiple sclerosis (MS). While past experiences are believed to influence efficacy beliefs, the explanations individuals provide for these experiences also may be critical. Our objective was to test the hypothesis that perceived success or failure to accumulate 150 min of physical activity in the previous week would moderate the relationship between the attributional dimension of stability and self-efficacy to exercise in the future. Forty-two adults with MS participated in this cross-sectional descriptive study. Participants completed questions assessing physical activity, perceived outcome for meeting the recommended level of endurance activity, attributions for the outcome, and exercise self-efficacy. Results from hierarchical multiple regression revealed a significant main effect for perceived outcome predicting self-efficacy that was qualified by a significant interaction. The final model, which included perceived outcome, stability, and the interaction term, predicted 37% of the variance in exercise self-efficacy, F (3, 38) = 7.27, p = .001. Our findings suggest that the best prediction of self-efficacy in the MS population may include the interaction of specific attributional dimensions with success/failure at meeting the recommended physical activity dose. Attributions may be another target for interventions aimed at increasing the physical activity in MS.

Plasma osteoprotegerin is associated with testosterone levels but unaffected by pioglitazone treatment in patients with polycystic ovary syndrome

OBJECTIVE

Increased osteoprotegerin (OPG) levels are associated with increased cardiovascular risk and decreased bone resorption. Pioglitazone treatment reduces the inflammatory state but may decrease bone mineral density (BMD). OPG levels during pioglitazone treatment have not previously been evaluated in polycystic ovary syndrome (PCOS).

RESEARCH DESIGN AND METHODS

Plasma OPG levels were measured in 30 PCOS patients before and after randomized treatment with 30 mg pioglitazone/placebo for 16 weeks. Fourteen age- and body mass index-matched healthy women were included as controls. Clinical and hormonal evaluations and whole body dual-energy X-ray absorptiometry scans were performed in all participants.

RESULTS

OPG levels were comparable in PCOS patients [12.0 (10.5-14.6) ng/ml] and controls [12.9 (11.7-14.9) ng/ml]. In PCOS patients (no.=30), OPG levels were positively associated with testosterone (r=0.43), PRL (r=0.47), Pyridinoline cross-linked carboxyterminal telopeptide of type I collagen (r=0.43), and hip BMD, whereas inverse associations were found between OPG levels and triglyceride (r=-0.49) and free fatty acid levels during euglycemic clamps (r=-0.38), all p<0.05. Pioglitazone treatment significantly decreased inflammatory markers, insulin sensitivity, and BMD without affecting OPG levels.

CONCLUSIONS

OPG levels were comparable in PCOS patients and controls and unchanged during insulin sensitizing treatment with pioglitazone. OPG levels were associated with BMD in PCOS. Future studies need to evaluate OPG as a marker of cardiovascular disease in PCOS.

Controlling hydrogenation of graphene on Ir(111)

Combined fast X-ray photoelectron spectroscopy and density functional theory calculations reveal the presence of two types of hydrogen adsorbate structures at the graphene/Ir(111) interface, namely, graphane-like islands and hydrogen dimer structures. While the former give rise to a periodic pattern, dimers tend to destroy the periodicity. Our data reveal distinctive growth rates and stability of both types of structures, thereby allowing one to obtain well-defined patterns of hydrogen clusters. The ability to control and manipulate the formation and size of hydrogen structures on graphene facilitates tailoring of its properties for a wide range of applications by means of covalent functionalization.

The Nordic prescription databases as a resource for pharmacoepidemiological research--a literature review

PURPOSE

All five Nordic countries have nationwide prescription databases covering all dispensed drugs, with potential for linkage to outcomes. The aim of this review is to present an overview of therapeutic areas studied and methods applied in pharmacoepidemiologic studies using data from these databases.

METHODS

The study consists of a Medline-based structured literature review of scientific papers published during 2005-2010 using data from the prescription databases in Denmark, Finland, Iceland, Norway, and Sweden, covering 25 million inhabitants. Relevant studies were analyzed in terms of pharmacological group, study population, outcomes examined, type of study (drug utilization vs. effect of drug therapy), country of origin, and extent of cross-national collaboration.

RESULTS

A total of 515 studies were identified. Of these, 262 were conducted in Denmark, 97 in Finland, 4 in Iceland, 87 in Norway, and 61 in Sweden. Four studies used data from more than one Nordic country. The most commonly studied drugs were those acting on the nervous system, followed by cardiovascular drugs and gastrointestinal/endocrine drugs. A total of 228 studies examined drug utilization and 263 focused on the effects and safety of drug therapy. Pregnant women were the most commonly studied population in safety studies, whereas prescribers' adherence to guidelines was the most frequent topic of drug utilization studies.

CONCLUSIONS

The Nordic prescription databases, with their possibility of record-linkage, represent an outstanding resource for assessing the beneficial and adverse effects of drug use in large populations, under routine care conditions, and with the potential for long-term follow-up.

Similar reference intervals for total testosterone in healthy young and elderly men: results from the Odense Androgen Study

CONTEXT

Ageing in men is associated with changes in levels of sex hormones.

OBJECTIVE

To evaluate differences in sex hormones in young and elderly men and the significance of comorbidity and fat mass on sex hormones in elderly men.

DESIGN

Cross-sectional.

PATIENTS

Seven hundred and eighty-three men aged 20-29 years and 600 men aged 60-74 years randomly recruited from the background population.

MEASUREMENTS

Sex hormones and sex hormone-binding globulin (SHBG) were measured, and reference intervals were determined in healthy individuals in both groups and in elderly men stratified according to whether they were obese or lean (waist circumference ≥102 cm).

RESULTS

Sex hormones were lower and SHBG higher in elderly men compared with the young cohort. Lower cut-offs for total testosterone (TT) in healthy, young and elderly men were similar [Lower cut-off (95% CI): Young: 11·7 (11·2-12·1) vs elderly: 11·2 (10·3-12·1) nmol/l], but lower and higher cut-offs of bioavailable testosterone (BT) and free testosterone (FT) were higher in young men. Higher levels of androgens were found in healthy elderly men compared with those with a chronic disease or obesity. Androgens were inversely associated with central fat mass (CFM), whereas SHBG was inversely and directly associated with CFM and lower extremity fat mass, respectively, in both young and elderly men.

CONCLUSION

Reference intervals for TT were comparable in healthy young and elderly men, but reference intervals for FT and BT were lower in elderly men due to higher levels of SHBG. Androgens and SHBG were lower in elderly men with chronic disease and inversely associated with CFM.

Polymorphisms of muscle genes are associated with bone mass and incident osteoporotic fractures in Caucasians

The interaction between muscle and bone is complex. The aim of this study was to investigate if variations in the muscle genes myostatin (MSTN), its receptor (ACVR2B), myogenin (MYOG), and myoD1 (MYOD1) were associated with fracture risk, bone mineral density (BMD), bone mineral content (BMC), and lean body mass. We analyzed two independent cohorts: the Danish Osteoporosis Prevention Study (DOPS), comprising 2,016 perimenopausal women treated with hormone therapy or not and followed for 10 years, and the Odense Androgen Study (OAS), a cross-sectional, population-based study on 783 men aged 20-29 years. Nine tag SNPs in the four genes were investigated. In the DOPS, individuals homozygous for the variant allele of the MSTN SNP rs7570532 had an increased risk of any osteoporotic fracture, with an HR of 1.82 (95 % CI 1.15-2.90, p = 0.01), and of nonvertebral osteoporotic fracture, with an HR of 2.02 (95 % CI 1.20-3.41, p = 0.01). The same allele was associated with increased bone loss (BMC) at the total hip of 4.1 versus 0.5 % in individuals either heterozygous or homozygous for the common allele (p = 0.006), a reduced 10-year growth in bone area at the total hip of 0.4 versus 2.2 and 2.3 % in individuals heterozygous or homozygous for the common allele, respectively (p = 0.01), and a nonsignificantly increased 10-year loss of total-hip BMD of 4.4 versus 2.7 and 2.9 % in individuals heterozygous or homozygous for the common allele, respectively (p = 0.08). This study is the first to demonstrate an association between a variant in MSTN and fracture risk and bone loss. Further studies are needed to confirm the findings.

Osteoprotegerin levels decrease during testosterone therapy in aging men and are associated with changed distribution of regional fat

The cardiovascular effects of testosterone treatment are debated. Osteoprotegerin (OPG) is an independent marker of cardiovascular risk. We investigated the effect of testosterone therapy on OPG levels in aging men with low normal bioavailable testosterone levels. A randomized, double-blinded, placebo-controlled study of 6 months testosterone therapy (gel) in 38 men aged 60-78 years with bioavailable testosterone <7.3 nmol/l and waist circumference >94 cm was performed. Clinical evaluation, OPG, and C-reactive protein (CRP) measurements were carried out. Lean body mass (LBM), total fat mass, and bone mineral density (BMD) were established by dual X-ray absorptiometry. Visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) were measured by magnetic resonance imaging. Power calculation was based on an increase in LBM during testosterone therapy and responders were defined as testosterone treated patients with increased LBM (Δ LBM positive), n=14. Data are presented as median (interquartile range). Testosterone therapy decreased total fat mass and SAT, whereas VAT was unchanged (n=38). OPG levels decreased during testosterone therapy (from 2.0 (1.9-2.5) to 1.9 (1.6-2.2) ng/ml, p<0.05 vs. placebo), whereas CRP levels were unchanged (n=38). In responders to testosterone therapy (n=14), ΔOPG levels were inversely associated with ΔSAT (r= - 0.60, p=0.03) and positively associated with ΔVAT (r=0.56, p=0.04). OPG levels decreased during testosterone therapy suggesting decreased cardiovascular risk. Decreased OPG levels were associated with changes in regional fat distribution and future studies are needed to further evaluate the association between OPG and regional fat mass distribution.