4,632 research outputs found
Empirical extinction coefficients for the GALEX, SDSS, 2MASS and WISE passbands
Using the "standard pair" technique of paring stars of almost nil and high
extinction but otherwise of almost identical stellar parameters from the SDSS,
and combing the SDSS, GALEX, 2MASS and WISE photometry ranging from the far UV
to the mid-IR, we have measured dust reddening in the FUV-NUV, NUV-u, u-g, g-r,
r-i, i-z, z-J, J-H, H-Ks, Ks-W1 and W1-W2 colors for thousands of Galactic
stars. The measurements, together with the E(B-V) values given by Schlegel et
al. (1998), allow us to derive the observed, model-free reddening coefficients
for those colors. The results are compared with previous measurements and the
predictions of a variety of Galactic reddening laws. We find that 1) The dust
reddening map of Schlegel et al. (1998) over-estimates E(B-V) by about 14 per
cent, consistent with the recent work of Schlafly et al. (2010) and Schlafly &
Finkbeiner (2011); 2) All the new reddening coefficients, except those for
NUV-u and u-g, prefer the R(V) = 3.1 Fitzpatrick reddening law rather than the
R(V) = 3.1 CCM and O'Donnell (O'Donnell 1994) reddening laws. Using the Ks-band
extinction coefficient predicted by the R(V) = 3.1 Fitzpatrick law and the
observed reddening coefficients, we have deduced new extinction coefficients
for the FUV, NUV, u, g, r, i, z, J, H, W1 and W2 passbands. We recommend that
the new reddening and extinction coefficients should be used in the future and
an update of the Fitzpatrick reddening law in the UV is probably necessary. We
stress however that the FUV- and NUV-band coefficients should be used with
caution given their relatively large measurement uncertainties. Finally,
potential applications of the "standard pair" technique with the LAMOST
Galactic surveys are discussed.Comment: 13 pages, 9 figures, accepted to MNRA
Empirical metallicity-dependent calibrations of effective temperature against colours for dwarfs and giants based on interferometric data
We present empirical metallicity-dependent calibrations of effective
temperature against colours for dwarfs of luminosity classes IV and V and for
giants of luminosity classes II and III, based on a collection from the
literature of about two hundred nearby stars with direct effective temperature
measurements of better than 2.5 per cent. The calibrations are valid for an
effective temperature range 3,100 - 10,000 K for dwarfs of spectral types M5 to
A0 and 3,100 - 5,700 K for giants of spectral types K5 to G5. A total of
twenty-one colours for dwarfs and eighteen colours for giants of bands of four
photometric systems, i.e. the Johnson (), the Cousins
(), the Sloan Digital Sky Survey (SDSS, ) and the Two
Micron All Sky Survey (2MASS, ), have been calibrated. Restricted
by the metallicity range of the current sample, the calibrations are mainly
applicable for disk stars ([Fe/H]). The normalized percentage
residuals of the calibrations are typically 2.0 and 1.5 per cent for dwarfs and
giants, respectively. Some systematic discrepancies at various levels are found
between the current scales and those available in the literature (e.g. those
based on the infrared flux method IRFM or spectroscopy). Based on the current
calibrations, we have re-determined the colours of the Sun. We have also
investigated the systematic errors in effective temperatures yielded by the
current on-going large scale low- to intermediate-resolution stellar
spectroscopic surveys. We show that the calibration of colour ()
presented in the current work provides an invaluable tool for the estimation of
stellar effective temperature for those on-going or upcoming surveys.Comment: 28 pages, 19 figures, 8 tables, accepted for publication in MNRA
Urban-Rural Differences in the Associations of Risk Factors With Epilepsy Based on the California Health Interview Survey: A Multiple Logistic Regression Analysis
Background: Previous studies provided inconsistent associations of smoking, stroke, and serious psychological distress (SPD) with epilepsy while urban-rural differences in the associations of risk factors with epilepsy are not well documented. Objectives: This study aimed to evaluate the associations of lifestyle, health conditions, and SPD with epilepsy and to examine whether the associations differ between urban and rural areas. Patients and Methods: A total of 604 adults with epilepsy and 42416 controls were selected from the 2005 California Health Interview Survey. Weighted univariate and multiple logistic regression analyses were used to estimate the associations of potential factors (behavioral factors, SPD, social factors and health conditions) with epilepsy. The odds ratios (ORs) with 95% confidence intervals (CIs) were estimated. Results: The overall prevalence of epilepsy was 1.3% and the prevalence was higher in urban area than rural area (1.4 vs. 1.1%). The prevalence of SPD was 11% in cases and 4% in controls, respectively. The percentage of stroke was higher in cases than in controls (9% vs. 2%). After adjusting for other factors using multiple logistic regression, current smoking, stroke, cancer, SPD and living in urban were positively significantly associated with epilepsy (OR = 1.74, 95% CI = 1.28 - 2.38; OR = 4.81, 95% CI = 3.13 - 7.41; OR = 1.52, 95% CI = 1.12 - 2.06; OR = 2.02, 95% CI = 1.39 - 2.92, and OR = 1.4, 95% CI = 1.08 - 1.81, respectively); while binge drinking was negatively associated with epilepsy (OR = 0.65, 95% CI = 0.43 - 0.99). Stratified by residence, in the urban area, current smoking and race were only associated with epilepsy. Stroke and SPD showed stronger association with epilepsy in the rural area (OR = 7.63, 95% CI = 3.68 - 15.8, and OR = 3.14, 95% CI = 1.52 - 6.47, respectively) comparing with urban region (OR = 4.51, 95% CI = 2.79 - 7.28 and OR = 1.9, 95% CI = 1.27 - 2.86, respectively). Conclusions: Smoking, stroke, and SPD were associated with epilepsy; while the associations differed between urban and rural areas
Rapid Remission in Peripheral T-Cell Lymphoma of the Nasal Type by the Bortezomib plus CHOP Therapy
Peripheral T-cell lymphoma (PTCL) is rare and difficult to treat for its high relapse rate. The authors report a case of PTCL of the skin, regarding which clinical and pathological features, treatment, and prognosis were discussed. A 66-year-old woman was admitted with complaints of enlarging erythematous noduloplaques on the right anterior tibial skin for one year and similar lesions on the left for 6 months. Surgical resection of right leg lesion and biopsy of enlarged inguinal lymph nodes histologically indicated a PTCL of the nasal type. The patient was treated by CHOP plus bortezomib, reached complete remission just after two courses of chemotherapy and then received another two as consolidation. The patient remained in remission for 11 months until local relapse. As for cutaneous lesions, detailed lymph node examination and prompt tissue biopsy are judicious choices prior to any medical management. The chemotherapy consisting of bortezomib and CHOP is safe and efficient in PTCL of the skin
Early transition from insulin to sulfonylureas in neonatal diabetes and follow-up: experience from China
Background: Sulfonylurea therapy can improve glycemic control and ameliorate neurodevelopmental outcomes in patients suffering from neonatal diabetes mellitus (NDM) with KCNJ11 or ABCC8 mutations. As genetic testing results are often delayed, it remains controversial whether sulfonylurea treatment should be attempted immediately at diagnosis or doctors should await genetic confirmation. Objective: This study aimed to investigate the effectiveness and safety of sulfonylurea therapy in Chinese NDM patients during infancy before genetic testing results were available. Methods: The medical records of NDM patients with their follow‐up details were reviewed and molecular genetic analysis was performed. Sulfonylurea transfer regimens were applied in patients diagnosed after May 2010, and glycemic status and side effects were evaluated in each patient. Results: There were 23 NDM patients from 22 unrelated families, 10 had KCNJ11 mutations, 3 harbored ABCC8 mutations, 1 had INS mutations, 4 had chromosome 6q24 abnormalities, 1 had a deletion at chromosome 1p36.23p36.12, and 4 had no genetic abnormality identified. Sixteen NDM infants were treated with glyburide at an average age of 49 days (range 14‐120 days) before genetic confirmation. A total of 11 of 16 (69%) were able to successfully switch to glyburide with a more stable glucose profile. The responsive glyburide dose was 0.51 ± 0.16 mg/kg/d (0.3‐0.8 mg/kg/d), while the maintenance dose was 0.30 ± 0.07 mg/kg/d (0.2‐0.4 mg/kg/d). No serious adverse events were reported. Conclusions: Molecular genetic diagnosis is recommended in all patients with NDM. However, if genetic testing results are delayed, sulfonylurea therapy should be considered before such results are received, even in infants with newly diagnosed NDM
Galactic Disk Bulk Motions as Revealed by the LSS-GAC DR2
We report a detailed investigation of the bulk motions of the nearby Galactic
stellar disk, based on three samples selected from the LSS-GAC DR2: a global
sample containing 0.57 million FGK dwarfs out to 2 kpc, a local subset
of the global sample consisting 5,400 stars within 150 pc, and an
anti-center sample containing 4,400 AFGK dwarfs and red clump stars
within windows of a few degree wide centered on the Galactic anti-center. The
global sample is used to construct a three-dimensional map of bulk motions of
the Galactic disk from the solar vicinity out to 2 kpc with a spatial
resolution of 250 pc. Typical values of the radial and vertical
components of bulk motion range from 15 km s to 15 km s, while
the lag behind the circular speed dominates the azimuthal component by up to
15 km s. The map reveals spatially coherent, kpc-scale stellar
flows in the disk, with typical velocities of a few tens km s. Bending-
and breathing-mode perturbations are clearly visible, and vary smoothly across
the disk plane. Our data also reveal higher-order perturbations, such as breaks
and ripples, in the profiles of vertical motion versus height. From the local
sample, we find that stars of different populations exhibit very different
patterns of bulk motion. Finally, the anti-center sample reveals a number of
peaks in stellar number density in the line-of-sight velocity versus distance
distribution, with the nearer ones apparently related to the known moving
groups. The "velocity bifurcation" reported by Liu et al. (2012) at
Galactocentric radii 10--11 kpc is confirmed. However, just beyond this
distance, our data also reveal a new triple-peaked structure.Comment: 27 pages, 17 figures, Accepted for publication in a special issue of
Research in Astronomy and Astrophysics on LAMOST science
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