2,881 research outputs found
Is HE 0436-4717 Anemic? A deep look at a bare Seyfert 1 galaxy
A multi-epoch, multi-instrument analysis of the Seyfert 1 galaxy HE 0436-4717
is conducted using optical to X-ray data from XMM-Newton and Swift (including
the BAT). Fitting of the UV-to-X-ray spectral energy distribution shows little
evidence of extinction and the X-ray spectral analysis does not confirm
previous reports of deep absorption edges from OVIII. HE 0436-4717 is a "bare"
Seyfert with negligible line-of-sight absorption making it ideal to study the
central X-ray emitting region. Three scenarios were considered to describe the
X-ray data: partial covering absorption, blurred reflection, and soft
Comptonization. All three interpretations describe the 0.5-10.0 keV spectra
well. Extrapolating the models to 100 keV results in poorer fits for the the
partial covering model. When also considering the rapid variability during one
of the XMM-Newton observations, the blurred reflection model appears to
describe all the observations in the most self-consistent manner. If adopted,
the blurred reflection model requires a very low iron abundance in HE
0436-4717. We consider the possibilities that this is an artifact of the
fitting process, but it appears possible that it is intrinsic to the object.Comment: 7 tables, 11 figures, 16 pages; accepted for publication in MNRAS 17
Feb. 201
Analysis of Genetic Polymorphisms as Risk Factors in Essential Hypertension and Type 2 Diabetes Mellitus among Malaysians
Genetic Polymorphisms are the variations found in the DNA sequences and they are
integral to the development of genetic markers to identify individuals at risk. The
genotypic distribution of various genetic polymorphisms involved in essential
hypertension (EHT) and type 2 diabetes mellitus subjects (T2DM) has been
established in many populations with conflicting results but in Malaysian subjects it
has not been well characterized. The main objective of this study was to determine
the association of various polymorphisms involved in the renin angiotensinaldosterone
system (RAAS), insulin receptor, lipoprotein lipase, interleukin gene and
G protein ß 3 subunit genes in EHT and T2DM of Malaysian subjects. This crosssectional
study includes 70 EHT without T2DM, 60 T2DM, 65 EHT with T2DM and
75 unrelated healthy control subjects. Genomic DNA was extracted from the
peripheral blood and the plasma was separated and analyzed for the biochemical
analyses. The genotypes of the various genetic polymorphisms were determined
using the polymerase chain reaction-restriction fragment length polymorphism
(PCR-RFLP), mutagenically PCR and the hot-start PCR methods. All PCR products and the restricted fragments were resolved electrophoretically on agarose and
polyacrylamide gels. Statistical analyses was done using SPPS version 14.0. The
baseline characteristics such as age, body mass index, diastolic blood pressure,
fasting plasma glucose, high density lipoprotein cholesterol and sodium differed
significantly (p<0.05) in case subjects compared to control subjects but not in low
density lipoprotein cholesterol, total cholesterol and potassium. The
insertion/deletion (I/D) and G2350A polymorphism of the angiotensin converting
enzyme (ACE) gene and the I/D polymorphism of the alpha adrenoceptor gene
differed significantly in EHT and T2DM subjects, whereas the A6G variant of the
angiotensinogen (AGT) gene differed significantly (p<0.05) in the EHT and
EHT+T2DM subjects when compared to the control subjects but not in the T2DM
subjects. However, the BglI and MboI polymorphisms of the renin gene, the A6244G
polymorphism of the insulin receptor gene, the S477X polymorphism of the
lipoprotein lipase gene, the C511T polymorphism of the interleukin gene and the
C825T polymorphism of the G protein ß 3 subunit genes did not differ significantly
(p>0.05) when compared to the control subjects. Therefore, the polymorphisms of
ACE, AGT and alpha adrenoceptor genes involved in RAAS were significantly
associated with EHT and T2DM in Malaysian subjects. The genotypes and alleles of
those polymorphisms can be considered as possible genetic markers or predisposing
risk factors for EHT and T2DM in Malaysian subjects
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Synthesis and Coordination Compounds of A Bis(Imino)Acenaphthene (Bian)-Supported N-Heterocyclic Carbene
The bis(imino)acenaphthene-supported N-heterocyclic carbene IPr(BIAN) has been prepared by deprotonation of the precursor imidazolium chloride. Treatment of IPr(BIAN) imidazolium chloride with Ag(2)O afforded the silver complex [IPr(BIAN)]AgCl which can be converted into the corresponding gold complex [IPr(BIAN)]AuCl by reaction with (tht)AuCl (tht = tetrahydrothiophene). The iridium complex [IPr(BIAN)]Ir(COD)Cl was prepared by reaction of the imidazolium chloride with KO(t)Bu and [Ir(COD)Cl](2) and subsequently converted to the carbonyl complex [IPr(BIAN)]Ir(CO)(2)Cl by exposure to an atmosphere of CO. All new compounds were characterized by single-crystal X-ray diffraction, multinuclear NMR, MS and HRMS data.Robert A. Welch Foundation F-0003National Science Foundation 0741973Chemistr
Solution of the differential equation (∂2∂x∂y + ax∂∂x + by∂∂y + cxy + ∂∂t) P(x, y, t) = 0 and the Bogoliubov transformation
AbstractAn eigen function expansion for the solution of the Lambropolous partial differential equation is obtained by the use of a transformation similar to the Bugolubov transformation familiar in Bose gas theory. Also the technique of normal ordering of operators is employed. The orthogonality properties of such solutions are also analysed
VIBRATION ANALYSIS OF A ROTATING TAPERED COMPOSITE BEAM WITH TIP MASS
In this study, free vibration responses of a rotating tapered composite beam with tip mass are investigated. The energy expressions for the kinetic and potential energies of a rotating composite beam with tip mass have been formulated. The energy expressions are then applied in Lagrange’s equations to develop the equation of motion of a composite beam with tip mass. The stiffness and mass matrices for a standard composite beam element with two end nodes with two degrees of freedom at each node are derived. Various parametric studies are performed to investigate the effect of tip mass and the rotational speed on the variation of natural frequencies of the composite beam. The investigations are also done to study the effect of hub radius on the natural frequencies. It is shown that the addition of tip mass increases the stiffness of the structure and consequently increases the natural frequencies
Neuroadaptations in the Cellular and Postsynaptic Group 1 Metabotropic Glutamate Receptor mGluR5 and Homer Proteins Following Extinction of Cocaine Self-administration
This study examined the role of group1 metabotropic glutamate receptor mGluR5 and associated postsynaptic scaffolding protein Homer1b/c in behavioral plasticity after three withdrawal treatments from cocaine self-administration. Rats self-administered cocaine or saline for 14 days followed by a withdrawal period during which rats underwent extinction training, remained in their home cages, orwere placed in the self-administration chambers in the absence of extinction. Subsequently, the tissue level and distribution of proteins in the synaptosomal fraction associated with the postsynaptic densitywere examined. Cocaine self-administration followed by home cage exposure reduced the mGluR5 protein in nucleus accumbens (NA) shell and dorsolateral striatum. While extinction training reduced mGluR5 protein in NAshell, NAcore and dorsolateral striatum did not display any change. The scaffolding protein PSD95 increased in NAcore of the extinguished animals. Extinction of drug seeking was associated with a significant decrease in the synaptosomal mGluR5 protein in NAshell and an increase in dorsolateral striatum, while that of NAcore was not modified. Interestingly, both Homer1b/c and PSD95 scaffolding proteins were decreased in the synaptosomal fraction after extinction training in NAshell but not NAcore. Extinguished drug-seeking behavior was also associated with an increase in the synaptosomal actin proteins in dorsolateral striatum. Therefore, extinction of cocaine seeking is associated with neuroadaptations in mGluR5 expression and distribution that are region-specific and consist of extinction-induced reversal of cocaine-induced adaptations aswell as emergent extinction-induced alterations. Concurrent plasticity in the scaffolding proteins further suggests that mGluR5 receptor neuroadaptations may have implications for synaptic function
Glutamatergic Plasticity in Medial Prefrontal Cortex and Ventral Tegmental Area Following Extended-Access Cocaine Self-Administration
Glutamate signaling in prefrontal cortex and ventral tegmental area plays an important role in the molecular and behavioral plasticity associated with addiction to drugs of abuse. The current study investigated the expression and postsynaptic density redistribution of glutamate receptors and synaptic scaffolding proteins in dorsomedial and ventromedial prefrontal cortex and ventral tegmental area after cocaine self-administration. After 14 days of extended-access (6 h/day) cocaine self-administration, rats were exposed to one of three withdrawal regimen for 10 days. Animals either stayed in home cages (Home), returned to self-administration boxes with the levers withdrawn (Box), or underwent extinction training (Extinction). Extinction training was associated with significant glutamatergic plasticity. In dorsomedial prefrontal cortex of the Extinction group, there was an increase in postsynaptic density GluR1, PSD95, and actin proteins; while postsynaptic density mGluR5 protein decreased and there was no change in NMDAR1, Homer1b/c, or PICK1 proteins. These changes were not observed in ventromedial prefrontal cortex or ventral tegmental area. In ventral tegmental area, Extinction training reversed the decreased postsynaptic density NMDAR1 protein in the Home and Box withdrawal groups. These data suggest that extinction of drug seeking is associated with selective glutamatergic plasticity in prefrontal cortex and ventral tegmental area that include modulation of receptor trafficking to postsynaptic density
Particle Motion and Scalar Field Propagation in Myers-Perry Black Hole Spacetimes in All Dimensions
We study separability of the Hamilton-Jacobi and massive Klein-Gordon
equations in the general Myers-Perry black hole background in all dimensions.
Complete separation of both equations is carried out in cases when there are
two sets of equal black hole rotation parameters, which significantly enlarges
the rotational symmetry group. We explicitly construct a nontrivial irreducible
Killing tensor associated with the enlarged symmetry group which permits
separation. We also derive first-order equations of motion for particles in
these backgrounds and examine some of their properties.Comment: 16 pages, LaTeX2
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