2,408 research outputs found
Most of the genetic covariation between major depressive and alcohol use disorders is explained by trait measures of negative emotionality and behavioral control
Background Mental health disorders commonly co-occur, even between conceptually distinct syndromes, such as internalizing and externalizing disorders. The current study investigated whether phenotypic, genetic, and environmental variance in negative emotionality and behavioral control account for the covariation between major depressive disorder (MDD) and alcohol use disorder (AUD). Method A total of 3623 members of a national twin registry were administered structured diagnostic telephone interviews that included assessments of lifetime histories of MDD and AUD, and were mailed self-report personality questionnaires that assessed stress reactivity (SR) and behavioral control (CON). A series of biometric models were fitted to partition the proportion of covariance between MDD and AUD into SR and CON. Results A statistically significant proportion of the correlation between MDD and AUD was due to variance specific to SR (men = 0.31, women = 0.27) and CON (men = 0.20, women = 0.19). Further, genetic factors explained a large proportion of this correlation (0.63), with unique environmental factors explaining the rest. SR explained a significant proportion of the genetic (0.33) and environmental (0.23) overlap between MDD and AUD. In contrast, variance specific to CON accounted for genetic overlap (0.32), but not environmental overlap (0.004). In total, SR and CON accounted for approximately 70% of the genetic and 20% of the environmental covariation between MDD and AUD. Conclusions This is the first study to demonstrate that negative emotionality and behavioral control confer risk for the co-occurrence of MDD and AUD via genetic factors. These findings are consistent with the aims of NIMH's RDoC proposal to elucidate how transdiagnostic risk factors drive psychopathology
Review of an Investigation of Ceramic Coatings for Metallic Turbine Parts and Other High-temperature Applications
No abstract availabl
Distinguishing cancerous from non-cancerous cells through analysis of electrical noise
Since 1984, electric cell-substrate impedance sensing (ECIS) has been used to
monitor cell behavior in tissue culture and has proven sensitive to cell
morphological changes and cell motility. We have taken ECIS measurements on
several cultures of non-cancerous (HOSE) and cancerous (SKOV) human ovarian
surface epithelial cells. By analyzing the noise in real and imaginary
electrical impedance, we demonstrate that it is possible to distinguish the two
cell types purely from signatures of their electrical noise. Our measures
include power-spectral exponents, Hurst and detrended fluctuation analysis, and
estimates of correlation time; principal-component analysis combines all the
measures. The noise from both cancerous and non-cancerous cultures shows
correlations on many time scales, but these correlations are stronger for the
non-cancerous cells.Comment: 8 pages, 4 figures; submitted to PR
Optically Selected BL Lacertae Candidates from the Sloan Digital Sky Survey Data Release Seven
We present a sample of 723 optically selected BL Lac candidates from the SDSS
DR7 spectroscopic database encompassing 8250 deg^2 of sky; our sample
constitutes one of the largest uniform BL Lac samples yet derived. Each BL Lac
candidate has a high-quality SDSS spectrum from which we determine
spectroscopic redshifts for ~60% of the objects. Redshift lower limits are
estimated for the remaining objects utilizing the lack of host galaxy flux
contamination in their optical spectra; we find that objects lacking
spectroscopic redshifts are likely at systematically higher redshifts.
Approximately 80% of our BL Lac candidates match to a radio source in
FIRST/NVSS, and ~40% match to a ROSAT X-ray source. The homogeneous
multiwavelength coverage allows subdivision of the sample into 637 radio-loud
BL Lac candidates and 86 weak-featured radio-quiet objects. The radio-loud
objects broadly support the standard paradigm unifying BL Lac objects with
beamed radio galaxies. We propose that the majority of the radio-quiet objects
may be lower-redshift (z<2.2) analogs to high-redshift weak line quasars (i.e.,
AGN with unusually anemic broad emission line regions). These would constitute
the largest sample of such objects, being of similar size and complementary in
redshift to the samples of high-redshift weak line quasars previously
discovered by the SDSS. However, some fraction of the weak-featured radio-quiet
objects may instead populate a rare and extreme radio-weak tail of the much
larger radio-loud BL Lac population. Serendipitous discoveries of unusual white
dwarfs, high-redshift weak line quasars, and broad absorption line quasars with
extreme continuum dropoffs blueward of rest-frame 2800 Angstroms are also
briefly described.Comment: 24 pages, 14 figures, 8 tables. Accepted for publication in A
A Large, Uniform Sample of X-ray Emitting AGN from the ROSAT All-Sky and Sloan Digital Sky Surveys: the Data Release 5 Sample
We describe further results of a program aimed to yield ~10^4 fully
characterized optical identifications of ROSAT X-ray sources. Our program
employs X-ray data from the ROSAT All-Sky Survey (RASS), and both optical
imaging and spectroscopic data from the Sloan Digital Sky Survey (SDSS).
RASS/SDSS data from 5740 deg^2 of sky spectroscopically covered in SDSS Data
Release 5 (DR5) provide an expanded catalog of 7000 confirmed quasars and other
AGN that are probable RASS identifications. Again in our expanded catalog, the
identifications as X-ray sources are statistically secure, with only a few
percent of the SDSS AGN likely to be randomly superposed on unrelated RASS
X-ray sources. Most identifications continue to be quasars and Seyfert 1s with
15<m<21 and 0.01<z<4; but the total sample size has grown to include very
substantial numbers of even quite rare AGN, e.g., now including several
hundreds of candidate X-ray emitting BL Lacs and narrow-line Seyfert 1
galaxies. In addition to exploring rare subpopulations, such a large total
sample may be useful when considering correlations between the X-ray and the
optical, and may also serve as a resource list from which to select the "best"
object (e.g., X-ray brightest AGN of a certain subclass, at a preferred
redshift or luminosity) for follow-on X-ray spectral or alternate detailed
studies.Comment: Accepted for publication in AJ; 32 pages, including 11 figures, and 6
example table
Nonlinear Magneto-Optical Response of - and -Wave Superconductors
The nonlinear magneto-optical response of - and -wave superconductors
is discussed. We carry out the symmetry analysis of the nonlinear
magneto-optical susceptibility in the superconducting state. Due to the surface
sensitivity of the nonlinear optical response for systems with bulk inversion
symmetry, we perform a group theoretical classification of the superconducting
order parameter close to a surface. For the first time, the mixing of singlet
and triplet pairing states induced by spin-orbit coupling is systematically
taken into account. We show that the interference of singlet and triplet
pairing states leads to an observable contribution of the nonlinear
magneto-optical Kerr effect. This effect is not only sensitive to the
anisotropy of the gap function but also to the symmetry itself. In view of the
current discussion of the order parameter symmetry of High-T
superconductors, results for a tetragonal system with bulk singlet pairing for
various pairing symmetries are discussed.Comment: 21 pages (REVTeX) with 8 figures (Postscript
A crossover intervention trial evaluating the efficacy of a chlorhexidine-impregnated sponge in reducing catheter-related bloodstream infections among patients undergoing hemodialysis
BACKGROUND: Catheter-related bloodstream infections (BSI) account for the majority of hemodialysis-related infections. There are no published data on the efficacy of the chlorhexidine-impregnated foam dressing at reducing catheter-related BSI in hemodialysis patients. DESIGN: Prospective non-blinded cross-over intervention trial to determine the efficacy of a chlorhexidine-impregnated foam dressing (Biopatch®) to reduce catheter-related BSI in hemodialysis patients. SETTING: Two outpatient dialysis centers PATIENTS: A total of 121 patients who were dialyzed through tunneled central venous catheters received the intervention during the trial. METHODS: The primary outcome of interest was the incidence of catheter-related bloodstream infections. A nested cohort study of all patients who received the Biopatch® Antimicrobial Dressing was also conducted. Backward stepwise logistic regression analysis was used to determine independent risk factors for development of BSI. RESULTS: 37 bloodstream infections occurred in the intervention group for a rate of 6.3 BSIs/1000 dialysis sessions and 30 bloodstream infections in the control group for a rate of 5.2 BSIs/1000 dialysis sessions and [RR 1.22, CI (0.76, 1.97); P=0.46]. The Biopatch® Antimicrobial Dressing was well-tolerated with only two patients (<2%) experiencing dermatitis that led to its discontinuation. The only independent risk factor for development of BSI was dialysis treatment at one dialysis center [aOR 4.4 (1.77, 13.65); P=0.002]. Age ≥ 60 years [aOR 0.28 (0.09, 0.82); P=0.02] was associated with lower risk for BSI. CONCLUSION: The use of a chlorhexidine-impregnated foam dressing (Biopatch®) did not decrease catheter-related BSIs among hemodialysis patients with tunneled central venous catheters
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