375 research outputs found
The Extended Blue Continuum and Line Emission around the Central Radio Galaxy in Abell 2597
We present results from detailed imaging of the centrally dominant radio
elliptical galaxy in the cooling flow cluster Abell 2597, using data obtained
with the Wide Field and Planetary Camera 2 (WFPC2) on the Hubble Space
Telescope (HST). This object is one of the archetypal "blue-lobed" cooling flow
radio elliptical galaxies, also displaying a luminous emission-line nebula, a
compact radio source, and a significant dust lane and evidence of molecular gas
in its center. We show that the radio source is surrounded by a complex network
of emission-line filaments, some of which display a close spatial association
with the outer boundary of the radio lobes. We present a detailed analysis of
the physical properties of ionized and neutral gas associated with the radio
lobes, and show that their properties are strongly suggestive of direct
interactions between the radio plasma and ambient gas. We resolve the blue
continuum emission into a series of knots and clumps, and present evidence that
these are most likely due to regions of recent star formation. We investigate
several possible triggering mechanisms for the star formation, including direct
interactions with the radio source, filaments condensing from the cooling flow,
or the result of an interaction with a gas-rich galaxy, which may also have
been responsible for fueling the active nucleus. We propose that the properties
of the source are plausibly explained in terms of accretion of gas by the cD
during an interaction with a gas-rich galaxy, which combined with the fact that
this object is located at the center of a dense, high-pressure ICM can account
for the high rates of star formation and the strong confinement of the radio
source.Comment: Astrophysical Journal, in press, 34 pages, includes 6 PostScript
figures. Latex format, uses aaspp4.sty and epsf.sty file
Role of the TCF4 gene intronic variant in normal variation of corneal endothelium
PURPOSE: To identify early features of Fuchs endothelial dystrophy (FED) in carriers of the rs613872(G) transcription factor 4 gene (TCF4) aged 20 to 21 years. METHODS: Prospective cohort study of people aged 20 to 21 years previously enrolled in the Western Australia Pregnancy (Raine) Cohort. Specular microscopy was performed using a noncontact specular microscopy (EM-3000; Tomey, Nagoya, Japan). Individual genotype data were extracted from the genome-wide Illumina 660 Quad Array. Analysis of the association between the rs613872 risk allele in TCF4 and specular microscopic measurements was conducted. RESULTS: Association between the rs613872 risk allele and corneal endothelial cell density (CD) as well as the coefficient of variation in cell shape was the main outcome measure. Genotype and specular microscopic data were available for a total of 445 participants (46% women). The median CD was 2851 and 2850 cells per square millimeter in the right and left eyes, respectively. No significant differences between intereye variability in endothelial CD were seen (right eye to left eye correlation = 0.64); however, a significant difference in variability of endothelial CD between men and women was observed (male: OD, 2839 ± 124 cells/mm and OS, 2845 ± 124 cells/mm vs. female: OD, 2838 ± 134 cells/mm and OS, 2842 ± 132 cells/mm; OD, P = 0.0013 and OS, P = 0.0016). Eleven individuals were homozygous for the rs613872 risk allele. We found no association between rs613872 genotype and CD or coefficient of variation. One of 11 homozygous GG individuals was found to have a gutta in 1 sample field on specular microscopy, whereas 2 of 297 TT individuals also had a gutta each in 1 sample field. CONCLUSIONS: We were unable to detect an association between TCF4 rs613872 genotype and the variation in corneal endothelial CD or variation in cell morphology in a healthy young adult population. Copyrigh
ROSAT X-ray Observations of the Cooling Flow Cluster A2597
The cluster A2597 was observed in X-rays with the ROSAT PSPC and HRI
detectors. The X-ray isophotes are oriented similarly to the optical isophotes
of the central cD galaxy and to the isopleths of the galaxy distribution in the
cluster, but are otherwise quite regular, suggesting that this cluster is
reasonably relaxed and in hydrostatic equilibrium. The merged HRI and PSPC
surface brightness profile is not adequately fit by a beta model because of the
central X-ray surface brightness peak, indicating the presence of a cooling
flow. If the central 108 arcsec in radius are excluded, an acceptable fit is
found which gives beta = 0.64 but only an upper limit to the core radius, rcore
< 78 arcsec. Within a radius of 2 Mpc, we found masses of Mgas = 1.2e14 Msun
and Mtot = 6.5e14 Msun, and a gas mass fraction of about 19%. Both the overall
cluster spectrum and the spatially resolved spectra within 300 kpc require the
presence of both hot gas and a cooling flow in the spectrum. The spectrally
determined total cooling rate of Mdot = 344 Msun/yr is in good agreement with
those derived from analyses of the X-ray surface brightness profile from the
Einstein IPC and the ROSAT HRI images. The ROSAT spatially resolved X-ray
spectra indicate that the cooling component is distributed over the inner ~300
kpc in radius of the cluster. We do not detect any significant excess X-ray
absorption toward the center of A2597, and we set a very conservative upper
limit on the excess column in front of the cooling flow region of NH < 1.72e20
cm**-2.Comment: 16 pages, 12 figures, LaTeX, emulateapj style, Astrophysical Journal
in pres
Elevated DNA Oxidation and DNA Repair Enzyme Expression in Brain White Matter in Major Depressive Disorder
Background: Pathology of white matter in brains of patients with major depressive disorder (MDD) is well-documented, but the cellular and molecular basis of this pathology are poorly understood.
Methods:Levels of DNA oxidation and gene expression of DNA damage repair enzymes were measured in Brodmann area 10 (BA10) and/or amygdala (uncinate fasciculus) white matter tissue from brains of MDD (n=10) and psychiatrically normal control donors (n=13). DNA oxidation was also measured in BA10 white matter of schizophrenia donors (n=10) and in prefrontal cortical white matter from control rats (n=8) and rats with repeated stress-induced anhedonia (n=8).
Results:DNA oxidation in BA10 white matter was robustly elevated in MDD as compared to control donors, with a smaller elevation occurring in schizophrenia donors. DNA oxidation levels in psychiatrically affected donors that died by suicide did not significantly differ from DNA oxidation levels in psychiatrically affected donors dying by other causes (non-suicide). Gene expression levels of two base excision repair enzymes, PARP1 and OGG1, were robustly elevated in oligodendrocytes laser captured from BA10 and amygdala white matter of MDD donors, with smaller but significant elevations of these gene expressions in astrocytes. In rats, repeated stress-induced anhedonia, as measured by a reduction in sucrose preference, was associated with increased DNA oxidation in white, but not gray, matter.
Conclusions:Cellular residents of brain white matter demonstrate markers of oxidative damage in MDD. Medications that interfere with oxidative damage or pathways activated by oxidative damage have potential to improve treatment for MDD
Author Correction: A population-specific reference panel empowers genetic studies of Anabaptist populations.
A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has not been fixed in the paper
Measurement of Inverse Pion Photoproduction at Energies Spanning the N(1440) Resonance
Differential cross sections for the process pi^- p -> gamma n have been
measured at Brookhaven National Laboratory's Alternating Gradient Synchrotron
with the Crystal Ball multiphoton spectrometer. Measurements were made at 18
pion momenta from 238 to 748 MeV/c, corresponding to E_gamma for the inverse
reaction from 285 to 769 MeV. The data have been used to evaluate the gamma n
multipoles in the vicinity of the N(1440) resonance. We compare our data and
multipoles to previous determinations. A new three-parameter SAID fit yields 36
+/- 7 (GeV)^-1/2 X 10^-3 for the A^n_1/2 amplitude of the P_11.Comment: 14 pages, 8 figures, submitted to PR
Associations between fruit and vegetable intake, leisure-time physical activity, sitting time and self-rated health among older adults : cross-sectional data from the WELL study
BackgroundLifestyle behaviours, such as healthy diet, physical activity and sedentary behaviour, are key elements of healthy ageing and important modifiable risk factors in the prevention of chronic diseases. Little is known about the relationship between these behaviours in older adults. The purpose of this study was to explore the relationship between fruit and vegetable (F&V) intake, leisure-time physical activity (LTPA) and sitting time (ST), and their association with self-rated health in older adults.MethodsThis cross-sectional study comprised 3,644 older adults (48% men) aged 55-65 years, who participated in the Wellbeing, Eating and Exercise for a Long Life ("WELL") study. Respondents completed a postal survey about their health and their eating and physical activity behaviours in 2010 (38% response rate). Spearman\u27s coefficient (rho) was used to evaluate the relationship between F&V intake, LTPA and ST. Their individual and shared associations with self-rated health were examined using ordinal logistic regression models, stratified by sex and adjusted for confounders (BMI, smoking, long-term illness and socio-demographic characteristics).ResultsThe correlations between F&V intake, LTPA and ST were low. F&V intake and LTPA were positively associated with self-rated health. Each additional serving of F&V or MET-hour of LTPA were associated with approximately 10% higher likelihood of reporting health as good or better among women and men. The association between ST and self-rated health was not significant in the multivariate analysis. A significant interaction was found (ST*F&V intake). The effect of F&V intake on self-rated health increased with increasing ST in women, whereas the effect decreased with increasing ST in men.ConclusionThis study contributes to the scarce literature related to lifestyle behaviours and their association with health indicators among older adults. The findings suggest that a modest increase in F&V intake, or LTPA could have a marked effect on the health of older adults. Further research is needed to fully understand the correlates and determinants of lifestyle behaviours, particularly sitting time, in this age group
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