155 research outputs found
Host Galaxies of Gamma-ray Bursts: Spectral Energy Distributions and Internal Extinction
We present BVRcIc broad-band flux spectra for the host galaxies of GRB970508,
GRB980613, GRB980703, GRB990123 and GRB991208 obtained with the 6-m telescope
of SAO RAS. The BVRcIc of these hosts are best fitted by the spectral
properties of template SEDs of starburst galaxies and that there is a
significant internal extinction in these host galaxies. We derived the absolute
magnitudes of the GRB host galaxies making use of SEDs for the starburst
galaxies. We performed the population synthesis modeling of the continuum
spectral energy distribution of the host galaxies of GRB970508 and GRB980703
using different extinction laws and assuming burst and exponential scenarios of
star formation. The comparison of BVRcIc broad-band flux spectra with the local
starburst galaxies templates and theoretical templates as well as direct
estimates (using Balmer emission lines) of the internal extinction shows that
it is likely to be of great importance to take into account effects of the
internal extinction in the host galaxies. From the SED of the host galaxy of
GRB991208 and from the intensity of their spectral lines it follows that this
is a GRB galaxy with the highest massive star-formation rate of all known GRB
galaxies. The reduced luminosity of these dusty galaxies (e.g. for the host of
GRB970508 A_V\sim 2 mag, for the host of GRB980703 A_V\sim 0.6 mag and for the
host of GRB991208 A_V\sim 2 mag) could explain the observational fact: none of
the observed GRB host galaxies with known distances is brighter than the local
galaxies with the luminosity L_*.Comment: Added acknowledgement
Prevalence, and associated risk factors, of self-reported diabetes mellitus in a sample of adult urban population in Greece: MEDICAL Exit Poll Research in Salamis (MEDICAL EXPRESS 2002)
BACKGROUND: The continuous monitoring and future prediction of the growing epidemic of diabetes mellitus worldwide presuppose consistent information about the extent of the problem. The aim of this study was to determine the prevalence of diagnosed diabetes and to identify associated risk factors in a sample of adult urban Greek population. METHODS: A cross-sectional population-based survey was conducted in municipality of Salamis, Greece, during an election day (2002). The study sample consisted of 2805 participants, aged 20–94 years. Data were collected using a standardized short questionnaire that was completed by a face-to-face interview. Multiple regression analyses were performed to evaluate the association of diabetes with potential risk factors. RESULTS: The overall prevalence of diagnosed diabetes was 8.7% (95% CI 7.7–9.8%). After age adjustment for the current adult population (2001 census) of Greece, the projection prevalence was calculated to 8.2%. Multivariate logistic regression analysis identified as independent risk factors: increasing age (odds ratio, OR = 1.07, 95% CI 1.06–1.08), male sex (OR = 1.43, 95% CI 1.04–1.95), overweight and obesity (OR = 1.97, 95% CI 1.29–3.01 and OR = 3.76, 95% CI 2.41–5.86, respectively), family history of diabetes (OR = 6.91, 95% CI 5.11–9.34), hypertension (OR = 2.19, 95% CI 1.60–2.99) and, among women, lower educational level (OR = 2.62, 95% CI 1.22–5.63). The prevalence of overweight and obesity, based on self-reported BMI, were 44.2% and 18.4%, respectively. Moreover, the odds for diabetes in obese subjects with family history were 25-fold higher than those with normal weight and without family history of diabetes, while the odds in overweight subjects with family history of diabetes were 15-fold higher. CONCLUSIONS: Our findings indicated that the prevalence of diabetes is high in Greek population. It is suggested that the main modifiable contributing factor is obesity, whose effect is extremely increased upon positive heredity presence
Agronomy, Harvesting Hybrid Sorghum
Photograph of harvesting hybrid grain sorghum
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