The bright gamma-ray burst GRB 050525a has been detected with the Swift observatory, providing unique multiwavelength coverage from the very earliest phases of the burst. The X-ray and optical/UV ...afterglow decay light curves both exhibit a steeper slope 60.15 days after the burst, indicative of a jet break. This jet break time combined with the total gamma-ray energy of the burst constrains the opening angle of the jet to be 3:2. We derive an empirical "time-lag" redshift from the BAT data of super(z) = 0.69 c 0.02, in good agreement with the spectroscopic redshift of 0.61. Prior to the jet break, the X-ray data can be modeled by a simple power law with index a = -1.2. However, after 300 s the X-ray flux brightens by about 30% compared to the power-law fit. The optical/UV data have a more complex decay, with evidence of a rapidly falling reverse shock component that dominates in the first minute or so, giving way to a flatter forward shock component at later times. The multiwavelength X-ray/UV/optical spectrum of the afterglow shows evidence for migration of the electron cooling frequency through the optical range within 25,000 s. The measured temporal decay and spectral indexes in the X-ray and optical/UV regimes compare favorably with the standard fireball model for gamma-ray bursts assuming expansion into a constant-density interstellar medium.
We present a generalized analytic formalism for the inverse Compton X-ray emission from hydrogen-poor supernovae and apply this framework to SN 2011fe using Swift X-Ray Telescope (XRT), UVOT, and ...Chandra observations. We characterize the optical properties of SN 2011fe in the Swift bands and find them to be broadly consistent with a "normal" SN Ia, however, no X-ray source is detected by either XRT or Chandra. We constrain the progenitor system mass-loss rate M < 2 x 10 super(-9) M sub(odot) yr super(-1) (3sigma c.l.) for wind velocity v sub(w), = 100km s super(-1). Our result rules out symbiotic binary progenitors for SN 2011fe and argues against Roche lobe overflowing subgiants and main-sequence secondary stars if gap 1% of the transferred mass is lost at the Lagrangian points. Regardless of the density profile, the X-ray non-detections are suggestive of a clean environment (n sub(CSM) < 150 cm super(-3)) for 2 x 10 super(15) lap R lap 5 x 10 super(16) cm around the progenitor site. This is either consistent with the bulk of material being confined within the binary system or with a significant delay between mass loss and supernova explosion. We furthermore combine X-ray and radio limits from Chomiuk et al. to constrain the post-shock energy density in magnetic fields. Finally, we searched for the shock breakout pulse using gamma-ray observations from the Interplanetary Network and find no compelling evidence for a supernova-associated burst. Based on the compact radius of the progenitor star we estimate that the shock breakout pulse was likely not detectable by current satellites.
The abundance of ammonia-oxidising bacterial (AOB) and ammonia-oxidising archaeal (AOA) (amoA) genes and ammonia oxidation rates were compared bimonthly from July 2008 to May 2011 in 4 contrasting ...coastal sediments in the western English Channel. Despite a higher abundance of AOA amoA genes within all sediments and at all time-points, rates of ammonia oxidation correlated with AOB and not AOA amoA gene abundance. Sediment type was a major factor in determining both AOB amoA gene abundance and AOB community structure, possibly due to deeper oxygen penetration into the sandier sediments, increasing the area available for ammonia oxidation. Decreases in AOB amoA gene abundance were evident during summer and autumn, with maximum abundance and ammonia oxidation rates occurring in winter and early spring. PCR-DGGE of AOB amoA genes indicated that no seasonal changes to community composition occurred; however, a gradual movement in community composition occurred at 3 of the sites studied. The lack of correlation between AOA amoA gene abundance and ammonium oxidation rates, or any other environmental variable measured, may be related to the higher spatial variation amongst measurements, obscuring temporal trends, or the bimonthly sampling, which may have been too infrequent to capture temporal variability in the deposition of fresh organic matter. Alternatively, AOA may respond to changing substrate concentrations by an increase or decrease in transcript rather than gene abundance.
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BFBNIB, NUK, PNG, UL, UM, UPUK
Purpose: Pretreatment hemoglobin (Hb) level has been reported to be an important prognostic factor for local control and survival in various malignancies. However, in many settings, the adverse ...effect of a low Hb may be related to more advanced disease. The purpose of this analysis was to assess the influence of pretreatment Hb on local control in a large series of patients with a localized cancer (T1/T2 glottic cancer, AJCC 1992) treated in a standard fashion.
Materials and Methods: Between January 1981 and December 1989, 735 patients (median age 63; 657 males, 78 females) with T1/T2 glottic cancer were treated with radiation therapy (RT). The standard RT prescription was 50 Gy in 20 fractions over 4 weeks (97% of patients). Factors studied for prognostic importance for local failure included pretreatment Hb, age, sex, T category, anterior commissure involvement, subglottic extension, and tumor bulk (presence of visible tumor vs. subclinical disease).
Results: With a median follow-up of 6.8 years (range 0.2–14.3), 131 patients have locally relapsed for an actuarial 5-year relapse-free rate of 81.7%. The 5-year actuarial survival was 75.8%. The mean pretreatment hemoglobin level was 14.8 g/dl and was similar in all prognostic categories. On multivariate analysis, using the Cox proportional hazards model, pretreatment Hb predicted for local failure after RT. The hazard ratio (HR) for relapse was calculated for various Hb levels. For example, the HR for a Hb of 12 g/dl vs. a Hb of 15 g/dl was 1.8 (95% confidence interval 1.2–2.5). Previously established factors, including gender, T category, subglottic extension, as well as tumor bulk, were also prognostically important for local control.
Conclusions: This analysis, in a large number of similarly treated patients, indicates that pretreatment Hb is an independent prognostic factor for local control in patients with T1/T2 carcinoma of the glottis treated with RT. The underlying biology of this observation needs to be explored, and using this information, it may be possible to develop strategies to improve treatment outcome.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
ABSTRACTVascular endothelial growth factor-B (VEGF-B) is closely related to VEGF-A, an effector of blood vessel growth during development and disease and a strong candidate for angiogenic therapies. ...To further study the in vivo function of VEGF-B, we have generated Vegfb knockout mice (Vegfb). Unlike Vegfa knockout mice, which die during embryogenesis, Vegfb mice are healthy and fertile. Despite appearing overtly normal, Vegfb hearts are reduced in size and display vascular dysfunction after coronary occlusion and impaired recovery from experimentally induced myocardial ischemia. These findings reveal a role for VEGF-B in the development or function of coronary vasculature and suggest potential clinical use in therapeutic angiogenesis. The full text of this article is available at http://www.circresaha.org.
Using data collected with the CLEO detector operating at the CESR e+e- collider at sqrts=3.97-4.26 GeV, we investigate 15 charmonium decay modes of the psi(4040), psi(4160), and Y(4260) resonances. ...We confirm, at 11 sigma significance, the BABAR Y(4260)-->pi+pi- J/psi discovery, make the first observation of Y(4260)--> pi(0)pi(0) J/psi (5.1 sigma), and find the first evidence for Y(4260)-->K+K- J/psi(3.7 sigma). We measure e+e- cross sections at sqrts=4.26 GeV as sigma(pi+pi- J/psi)=58(+12)(-10)+/-4 pb, sigma(pi(0)pi(0) J/psi)=23(+12)(-8)+/-1 pb, and sigma(K+K- J/psi)=9(+9)(-5)+/-1 pb, in which the uncertainties are statistical and systematic, respectively. Upper limits are placed on other decay rates from all three resonances.
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CMK, CTK, FMFMET, IJS, NUK, PNG, UM
Summary
Methodological limitations preclude determination of the association between sleep duration and bone mineral density (BMD) from existing literature. This was the first study to use
objective
...sleep duration to determine its association with BMD. Nocturnal sleep duration, assessed objectively (actigraphy) or subjectively (questionnaire), was not independently associated with BMD in postmenopausal women.
Introduction
Both long and short
self-reported
sleep durations are associated with low bone mineral density (BMD) in men and women. The association between sleep duration measured by actigraphy and BMD in postmenopausal women is unknown.
Methods
The Study of Osteoporotic Fractures (SOF) ancillary sleep study was used to determine the association between sleep duration and BMD at the total hip and femoral neck in postmenopausal women ≥ 75 years old. Sleep duration was assessed by wrist actigraphy (average 4 nights) and questionnaire. BMD was compared between postmenopausal women with short (< 6 h/night) vs. NIH-recommended (7–8 h/night) sleep durations. Data were analyzed using a 2-sample
t
test (unadjusted) and multivariate regression model (adjusted). Simple linear regression was used to estimate the difference in BMD per additional hour of sleep when sleep duration was considered as a continuous, rather than dichotomized, variable.
Results
Total hip BMD was higher in women with actigraphically assessed shorter sleep duration in unadjusted models only. No clinically or statistically significant differences in total hip or femoral neck BMD were observed according to nocturnal sleep duration after adjusting for body mass index (BMI) in dichotomized (
N
= 874) or continuous (
N
= 1624) sleep duration models or when subjective sleep duration was used. When sleep duration included daytime naps, longer sleep duration was associated with lower total hip BMD (
β
= − 0.005,
p
= 0.04).
Conclusions
Nocturnal sleep duration, whether assessed objectively (actigraphy) or subjectively (questionnaire), was not independently associated with BMD in older postmenopausal women.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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