640 research outputs found
Marked response to VNS in a post-cingulotomy patient: Implications for the mechanism of action of VNS in TRD
AbstractTreatment-resistant major depression (TRMD, major depressive disorder that fails to respond to numerous therapies) is a relatively common and clinically challenging disorder. In many cases, the most severely affected TRMD patients have received surgical intervention (subcaudate tractotomy, limbic leucotomy, anterior capsulotomy, and anterior cingulotomy). New treatments, including vagus nerve stimulation (VNS) and deep brain stimulation, have emerged to treat individuals with TRMD. We describe the case of a woman, 53 years of age, with a long and sustained history of TRMD (33 years), which was unresponsive to numerous treatments (multiple pharmacotherapies, psychotherapy, electroconvulsive therapy [ECT]). Additionally, her TRMD failed to respond to a bilateral anterior cingulotomy. She underwent placement of a cervical vagus nerve stimulator and a brief course of ECT (3 unilateral treatments). Her depression improved markedly, and it has remained in sustained remission for 3.5 years. This case suggests a potential synergistic effect of VNS and ECT, as well as provides possible clues to the neural circuitry of VNS in TRMD.</jats:p
Understanding mechanisms of genetic risk for adolescent internalizing and externalizing problems: The mediating role of parenting and personality
Genetic predispositions play an important role in the development of internalizing and externalizing behaviors. Understanding the mechanisms through which genetic risk unfolds to influence these developmental outcomes is critical for developing prevention and intervention efforts, capturing key elements of Irv's research agenda and scientific legacy. In this study, we examined the role of parenting and personality in mediating the effect of genetic risk on adolescents' major depressive disorder and conduct disorder symptoms. Longitudinal data were drawn from a sample of 709 European American adolescents and their mothers from the Collaborative Studies on Genetics of Alcoholism. Results from multivariate path analysis indicated that adolescents' depressive symptoms genome-wide polygenic scores (DS_GPS) predicted lower parental knowledge, which in turn was associated with more subsequent major depressive disorder and conduct disorder symptoms. Adolescents' DS_GPS also had indirect effects on these outcomes via personality, with a mediating effect via agreeableness but not via other dimensions of personality. Findings revealed that the pattern of associations was similar across adolescent gender. Our findings emphasize the important role of evocative gene-environment correlation processes and intermediate phenotypes in the pathways of risk from genetic predispositions to complex adolescent outcomes
Quantum Time and Spatial Localization: An Analysis of the Hegerfeldt Paradox
Two related problems in relativistic quantum mechanics, the apparent
superluminal propagation of initially localized particles and dependence of
spatial localization on the motion of the observer, are analyzed in the context
of Dirac's theory of constraints. A parametrization invariant formulation is
obtained by introducing time and energy operators for the relativistic particle
and then treating the Klein-Gordon equation as a constraint. The standard,
physical Hilbert space is recovered, via integration over proper time, from an
augmented Hilbert space wherein time and energy are dynamical variables. It is
shown that the Newton-Wigner position operator, being in this description a
constant of motion, acts on states in the augmented space. States with strictly
positive energy are non-local in time; consequently, position measurements
receive contributions from states representing the particle's position at many
times. Apparent superluminal propagation is explained by noting that, as the
particle is potentially in the past (or future) of the assumed initial place
and time of localization, it has time to propagate to distant regions without
exceeding the speed of light. An inequality is proven showing the Hegerfeldt
paradox to be completely accounted for by the hypotheses of subluminal
propagation from a set of initial space-time points determined by the quantum
time distribution arising from the positivity of the system's energy. Spatial
localization can nevertheless occur through quantum interference between states
representing the particle at different times. The non-locality of the same
system to a moving observer is due to Lorentz rotation of spatial axes out of
the interference minimum.Comment: This paper is identical to the version appearing in J. Math. Phys.
41; 6093 (Sept. 2000). The published version will be found at
http://ojps.aip.org/jmp/. The paper (40 page PDF file) has been completely
revised since the last posting to this archiv
Some examples of exponentially harmonic maps
The aim of this paper is to study some examples of exponentially harmonic
maps. We study such maps firstly on flat euclidean and Minkowski spaces and
secondly on Friedmann-Lema\^ itre universes. We also consider some new models
of exponentially harmonic maps which are coupled with gravity which happen to
be based on a generalization of the lagrangian for bosonic strings coupled with
dilatonic field.Comment: 16 pages, 5 figure
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ADH1B is associated with alcohol dependence and alcohol consumption in populations of European and African ancestry.
A coding variant in alcohol dehydrogenase 1B (ADH1B) (rs1229984) that leads to the replacement of Arg48 with His48 is common in Asian populations and reduces their risk for alcoholism, but because of very low allele frequencies the effects in European or African populations have been difficult to detect. We genotyped and analyzed this variant in three large European and African-American case-control studies in which alcohol dependence was defined by the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) criteria, and demonstrated a strong protective effect of the His48 variant (odds ratio (OR) 0.34, 95% confidence interval (CI) 0.24, 0.48) on alcohol dependence, with genome-wide significance (6.6 × 10(-10)). The hypothesized mechanism of action involves an increased aversive reaction to alcohol; in keeping with this hypothesis, the same allele is strongly associated with a lower maximum number of drinks in a 24-hour period (lifetime), with P=3 × 10(-13). We also tested the effects of this allele on the development of alcoholism in adolescents and young adults, and demonstrated a significantly protective effect. This variant has the strongest effect on risk for alcohol dependence compared with any other tested variant in European populations
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ANSL-V: ENDF/B-V based multigroup cross-section libraries for Advanced Neutron Source (ANS) reactor studies. Supplement 1
The original ANSL-V cross-section libraries (ORNL-6618) were developed over a period of several years for the physics analysis of the ANS reactor, with little thought toward including the materials commonly needed for shielding applications. Materials commonly used for shielding applications include calcium barium, sulfur, phosphorous, and bismuth. These materials, as well as {sup 6}Li, {sup 7}Li, and the naturally occurring isotopes of hafnium, have been added to the ANSL-V libraries. The gamma-ray production and gamma-ray interaction cross sections were completely regenerated for the ANSL-V 99n/44g library which did not exist previously. The MALOCS module was used to collapse the 99n/44g coupled library to the 39n/44g broad- group library. COMET was used to renormalize the two-dimensional (2- D) neutron matrix sums to agree with the one-dimensional (1-D) averaged values. The FRESH module was used to adjust the thermal scattering matrices on the 99n/44g and 39n/44g ANSL-V libraries. PERFUME was used to correct the original XLACS Legendre polynomial fits to produce acceptable distributions. The final ANSL-V 99n/44g and 39n/44g cross-section libraries were both checked by running RADE. The AIM module was used to convert the master cross-section libraries from binary coded decimal to binary format (or vice versa)
Computational Discovery of Lanthanide Doped and Co-Doped Y₃Al₅O₁₂ for Optoelectronic Applications
We systematically elucidate the optoelectronic properties of rare-earth doped and Ce co-doped yttrium aluminum garnet (YAG) using hybrid exchange-correlation functional based density functional theory. The predicted optical transitions agree with the experimental observations for single doped Ce:YAG, Pr:YAG, and co-doped Er,Ce:YAG. We find that co-doping of Ce-doped YAG with any lanthanide except Eu and Lu lowers the transition energies; we attribute this behavior to the lanthanide-induced change in bonding environment of the dopant atoms. Furthermore, we find infrared transitions only in case of the Er, Tb, and Tm co-doped Ce:YAG and suggest Tm,Ce:YAG and Tb,Ce:YAG as possible functional materials for efficient spectral up-conversion devices
Common genetic risk of major depression and nicotine dependence: The contribution of antisocial traits in a United States veteran male twin cohort
Many studies that found associations between depression and nicotine dependence have ignored possible shared genetic influences associated with antisocial traits. The present study examined the contribution of genetic and environmental effects associated with conduct disorder (CD) and antisocial personality disorder (ASPD) to the comorbidity of major depression (MD) and nicotine dependence (ND). A telephone diagnostic interview, the Diagnostic Interview Schedule-III-R, was administered to eligible twins from the Vietnam Era Twin (VET) Registry in 1992. Multivariate genetic models were fitted to 3360 middle-aged and predominantly white twin pairs (1868 monozygotic, 1492 dizygotic pairs) of which both members completed the pertinent diagnostic interview sections. Genetic influences on CD accounted for 100%, 68%, and 50% of the total genetic variance in risk for ASPD, MD and ND, respectively. After controlling for genetic influences on CD, the partial genetic correlation between MD and ND was no longer statistically significant. Nonshared environmental contributions to the comorbidity among these disorders were not significant. This study not only demonstrates that the comorbidity between ND and MD is influenced by common genetic risk factors, but also further suggests that the common genetic risk factors overlapped with those for antisocial traits such as CD and ASPD in men
Environment and Co-occurring Native Mussel Species, but Not Host Genetics, Impact the Microbiome of a Freshwater Invasive Species (Corbicula fluminea)
The Asian clam Corbicula fluminea (Family: Cyneridae) has aggressively invaded freshwater habitats worldwide, resulting in dramatic ecological changes and declines of native bivalves such as freshwater mussels (Family: Unionidae), one of the most imperiled faunal groups. Despite increases in our knowledge of invasive C. fluminea biology, little is known of how intrinsic and extrinsic factors, including co-occurring native species, influence its microbiome. We investigated the gut bacterial microbiome across genetically differentiated populations of C. fluminea in the Tennessee and Mobile River Basins in the Southeastern United States and compared them to those of six co-occurring species of native freshwater mussels. The gut microbiome of C. fluminea was diverse, differed with environmental conditions and varied spatially among rivers, but was unrelated to host genetic variation. Microbial source tracking suggested that the gut microbiome of C. fluminea may be influenced by the presence of co-occurring native mussels. Inferred functions from 16S rRNA gene data using PICRUST2 predicted a high prevalence and diversity of degradation functions in the C. fluminea microbiome, especially the degradation of carbohydrates and aromatic compounds. Such modularity and functional diversity of the microbiome of C. fluminea may be an asset, allowing to acclimate to an extensive range of nutritional sources in invaded habitats, which could play a vital role in its invasive success
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