448 research outputs found
Infrared emission towards SN 1987A 11 years after outburst: Measurements with ISOCAM
We present measurements of the mid-infrared (MIR) emission from SN 1987A,
made using the Infrared Space Observatory (ISO) 11 years after outburst. They
are the only late epoch detections of this source in the thermal IR regime. The
position of the source, determined from an offset to an IR-emitting star,
suggests that the emission is associated with SN 1987A or its extended
supernova remnant (SNR). A predominantly circumstellar origin is however
suggested by the size and orientation of the IR-emitting region, which is
comparable with the extension of the inner ring seen with the Hubble Space
Telescope (HST). The emission is most probably from collisionally-heated
circumstellar grains embedded in shocked gas downstream of the blast wave. The
MIR extent is consistent with the hypothesis that the blast wave was
propagating into material of moderate density interior to the thick inner ring
at the epoch of the ISOCAM observations
Cervical lateral mass screw fixation without fluoroscopic control: analysis of risk factors for complications associated with screw insertion
Observational study to characterise 24-hour COPD symptoms and their relationship with patient-reported outcomes: results from the ASSESS study
Transformations structurelles et essor du métal
The role of multiattribute utility theory is first placed in the overall context of decision analysis. Then an approach that has proven useful in adapting the theory to be a practical tool is illustrated. Several cases where multiattribute utility has been used are briefly discussed. These include both operational and strategic problems involving, for example, siting of large-scale facilities (airports, power plants), medical treatment, the structuring corporate objectives, environmental management, and personal investment strategy
Surgical resectability of pancreatic adenocarcinoma: CTA
Imaging studies play an important role in the diagnosis and management of patients with pancreatic adenocarcinoma. Computed tomography (CT) is the most widely available and best validated modality for imaging these patients. Meticulous technique following a well-designed pancreas protocol is essential for maximizing the diagnostic efficacy of CT. After the diagnosis of pancreatic adenocarcinoma is made, the key to management is staging to determine resectability. In practice, staging often entails predicting the presence or absence of vascular invasion by tumor, for which several radiologic grading systems exist. With advances in surgical techniques, the definition of resectability is in evolution, and it is crucial that radiologists have an understanding of the implications of findings that are relevant to the determination of resectability
Production of phi mesons at mid-rapidity in sqrt(s_NN) = 200 GeV Au+Au collisions at RHIC
We present the first results of meson production in the K^+K^- decay channel
from Au+Au collisions at sqrt(s_NN) = 200 GeV as measured at mid-rapidity by
the PHENIX detector at RHIC. Precision resonance centroid and width values are
extracted as a function of collision centrality. No significant variation from
the PDG accepted values is observed. The transverse mass spectra are fitted
with a linear exponential function for which the derived inverse slope
parameter is seen to be constant as a function of centrality. These data are
also fitted by a hydrodynamic model with the result that the freeze-out
temperature and the expansion velocity values are consistent with the values
previously derived from fitting single hadron inclusive data. As a function of
transverse momentum the collisions scaled peripheral.to.central yield ratio RCP
for the is comparable to that of pions rather than that of protons. This result
lends support to theoretical models which distinguish between baryons and
mesons instead of particle mass for explaining the anomalous proton yield.Comment: 326 authors, 24 pages text, 23 figures, 6 tables, RevTeX 4. To be
submitted to Physical Review C as a regular article. Plain text data tables
for the points plotted in figures for this and previous PHENIX publications
are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm
Parasites of native Cichlidae populations and invasive Oreochromis niloticus (Linnaeus, 1758) in tributary of Amazonas River (Brazil)
Infrared emission towards 11 years after outburst: Properties of the circumstellar dust
Detailed models are presented for the late epoch mid infrared (MIR) emission
from collisionally heated grains in the shocked circumstellar gas around SN
1987A. Thermal dust emission from a region of moderate density interior to the
thick inner ring seen with the Hubble Space Telescope (HST) is found to be a
natural explanation for the MIR spectral energy distribution measured by
ISOCAM. The MIR-spectrum can be reproduced by a mixture of silicate-iron or
silicate-graphite grains or by a composition of pure graphite grains. A
composition of pure iron grains on the other hand can be excluded and a pure
silicate composition does not seem to be very likely. The dust-to-gas ratio in
the interaction zone is ~0.01%, an order of magnitude lower than estimates for
dust abundances in the winds of red supergiant (RSG) stars in the LMC. This low
dust abundance can be accounted for by a combination of evaporation through the
UV-flash from the supernova outburst and subsequent sputtering in the shocked
gas. For this explanation to hold, dust in the pre-supernova circumstellar
medium (CSM) would have to have been predominantly composed of grains other
than graphite, with a maximum size smaller than ~0.1 microns
Factors associated with seropositivity for APGL-Iamong household contacts of leprosy patients
Sex Differences in the Association between Serum Levels of Testosterone and Frailty in an Elderly Population: The Toledo Study for Healthy Aging
BACKGROUND: Age-associated decline in testosterone levels represent one of the potential mechanisms involved in the development of frailty. Although this association has been widely reported in older men, very few data are available in women. We studied the association between testosterone and frailty in women and assessed sex differences in this relationship. METHODS: We used cross-sectional data from the Toledo Study for Healthy Aging, a population-based cohort study of Spanish elderly. Frailty was defined according to Fried's approach. Multivariate odds-ratios (OR) and 95% confidence intervals (CI) associated with total (TT) and free testosterone (FT) levels were estimated using polytomous logistic regression. RESULTS: In women, there was a U-shaped relationship between FT levels and frailty (p for FT(2) = 0.03). In addition, very low levels of FT were observed in women with ≥ 4 frailty criteria (age-adjusted geometric means = 0.13 versus 0.37 in subjects with <4 components, p = 0.010). The association of FT with frailty appeared confined to obese women (p-value for interaction = 0.05).In men, the risk of frailty levels linearly decreased with testosterone (adjusted OR for frailty = 2.9 (95%CI, 1.6-5.1) and 1.6 (95%CI, 1.0-2.5), for 1 SD decrease in TT and FT, respectively). TT and FT showed association with most of frailty criteria. No interaction was found with BMI. CONCLUSION: There is a relationship between circulating levels of FT and frailty in older women. This relation seems to be modulated by BMI. The relevance and the nature of the association of FT levels and frailty are sex-specific, suggesting that different biological mechanisms may be involved
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