406 research outputs found
Peace journalismâcritical discourse case study: media and the plan for Swedish and Norwegian defence cooperation
PURPOSE: To describe the occurrence of atypical, bilateral detachment of the macular neuroepithelium and Klinefelter syndrome in a young patient. METHODS: Case report. RESULTS: A 20-year-old male of Chinese origin with karyotype 47,XXY presented with bilateral central neurosensory retinal detachment. There was spontaneous improvement. CONCLUSIONS: An atypical form of detachment of the macular neuroepithelium was seen in a young patient with Klinefelter syndrome. The pathophysiological mechanism is not clear. The possibility of a hormonal imbalance is discussed. A differential diagnostic consideration is central serous chorioretinopathy and a mild form of Vogt-Koyanagi-Harada syndrome. This case is of interest because of the rarity of association between Klinefelter syndrome and chorioretinal abnormalities
LOFAR: A new radio telescope for low frequency radio observations: Science and project status
LOFAR, the Low Frequency Array, is a large radio telescope consisting about
100 soccer field sized antenna stations spread over a region of 400 km in
diameter. It will operate in the frequency range from ~10 to 240 MHz, with a
resolution at 240 MHz of better than an arcsecond. Its superb sensitivity will
allow for a broad range of astrophysical studies. In this contribution we first
discuss four major areas of astrophysical research in which LOFAR will
undoubtedly make important contributions: reionisation, distant galaxies and
AGNs, transient radio sources and cosmic rays. Subsequently, we will discuss
the technical concept of the instrument and the status of the LOFAR projectComment: 8 pages, 2 figures, to appear in the proceedings of the XXI Texas
Symposium on Relativistic Astrophysics held on December 9--13 2002, in
Florence, Ital
Completeness in Photometric and Spectroscopic Searches for Clusters
We investigate, using simulated galaxy catalogues, the completeness of
searches for massive clusters of galaxies in redshift surveys or imaging
surveys with photometric redshift estimates, i.e. what fraction of clusters
(M>10^14/h Msun) are found in such surveys. We demonstrate that the matched
filter method provides an efficient and reliable means of identifying massive
clusters even when the redshift estimates are crude. In true redshift surveys
the method works extremely well. We demonstrate that it is possible to
construct catalogues with high completeness, low contamination and both varying
little with redshift.Comment: ApJ in press, 15 pages, 10 figure
Large scale anisotropies on halo infall
We perform a statistical analysis of the peculiar velocity field around dark
matter haloes in numerical simulations. We examine different properties of the
infall of material onto haloes and its relation to central halo shapes and the
shape of the large scale surrounding regions (LSSR). We find that the amplitude
of the infall velocity field along the halo shape minor axis is larger than
that along the major axis. This is consistent for general triaxial haloes, and
for both prolate and oblate systems. We also report a strong anisotropy of the
velocity field along the principal axes of the LSSR. The infall velocity field
around dark matter haloes reaches a maximum value along the direction of the
minor axis of the LSSR, whereas along the direction of its major axis, it
exhibits the smallest velocities. We also analyse the dependence of the matter
velocity field on the local environment. The amplitude of the infall velocity
at high local density regions is larger than at low local density regions. The
velocity field tends to be more laminar along the direction towards the minor
axis of the LSSR, where the mean ratio between flow velocity and velocity
dispersion is of order unity and nearly constant up to scales of 15 Mpc/h. We
also detect anisotropies in the outflowing component of the velocity field,
showing a maximum amplitude along the surrounding LSSR major axis.Comment: 12 pages, 9 figures, accepted for publication in Monthly Notices of
the Royal Astronomical Societ
Redshifts in the Southern Abell Redshift Survey Clusters. I. The Data
The Southern Abell Redshift Survey contains 39 clusters of galaxies with
redshifts in the range 0.0 < z < 0.31 and a median redshift depth of z =
0.0845. SARS covers the region 0 21h (while
avoiding the LMC and SMC) with b > 40. Cluster locations were chosen from the
Abell and Abell-Corwin-Olowin catalogs while galaxy positions were selected
from the Automatic Plate Measuring Facility galaxy catalog with
extinction-corrected magnitudes in the range 15 <= b_j < 19. SARS utilized the
Las Campanas 2.5 m duPont telescope, observing either 65 or 128 objects
concurrently over a 1.5 sq deg field. New redshifts for 3440 galaxies are
reported in the fields of these 39 clusters of galaxies.Comment: 20 pages, 5 figures, accepted for publication in the Astronomical
Journal, Table 2 can be downloaded in its entirety from
http://trotsky.arc.nasa.gov/~mway/SARS1/sars1-table2.cs
ROSAT PSPC Observations of the Richest () ACO Clusters
We have compiled an X-ray catalog of optically selected rich clusters of
galaxies observed by the PSPC during the pointed GO phase of the ROSAT mission.
This paper contains a systematic X-ray analysis of 150 clusters with an optical
richness classification of from the ACO catalog (Abell, Corwin, and
Olowin 1989). All clusters were observed within 45' of the optical axis of the
telescope during pointed PSPC observations. For each cluster, we calculate: the
net 0.5-2.0 keV PSPC count rate (or upper limit) in a 1 Mpc radius
aperture, 0.5-2.0 keV flux and luminosity, bolometric luminosity, and X-ray
centroid. The cluster sample is then used to examine correlations between the
X-ray and optical properties of clusters, derive the X-ray luminosity function
of clusters with different optical classifications, and obtain a quantitative
estimate of contamination (i.e, the fraction of clusters with an optical
richness significantly overestimated due to interloping galaxies) in the ACO
catalog
Early host responses to avian influenza A virus are prolonged and enhanced at transcriptional level depending on maturation of the immune system
A lack of antibody formation against inactivated influenza virus after aerosol vaccination in presence or absence of adjuvantia
Reduced immune reaction prevents immunopathology after challenge with avian influenza virus: A transcriptomics analysis of adjuvanted vaccines
To gain more insight in underlying mechanisms correlating to protection against avian influenza virus (AIV) infection, we investigated correlates of protection after AIV H9N2 infection and studied the contribution of different adjuvants to a protective response at host transcriptional level. One-day-old chickens were immunised with inactivated H9N2 supplemented with w/o, Al(OH)3, CpG or without adjuvant. Two weeks later, birds were homologously challenged and at 1-4 days post challenge (d.p.c.) trachea and lung were collected. Birds immunised with H9N2+w/o or H9N2+Al(OH)3 were protected against challenge infection and had lower viral RNA expression, less immune related genes induced after challenge, a lower amplitude of change of gene expression and smaller cellular influxes compared to the higher and prolonged gene expression in unprotected birds. We show that a limited number of differentially expressed genes correlates with reduced immune activation and subsequently reduced immunopathology after challenge with AIV
The Las Campanas Distant Cluster Survey -- The Correlation Function
We present the first non-local (z>0.2) measurement of the cluster-cluster
spatial correlation length, using data from the Las Campanas Distant Cluster
Survey (LCDCS). We measure the angular correlation function for
velocity-dispersion limited subsamples of the catalog at estimated redshifts of
0.35<z_{est}<0.575, and derive spatial correlation lengths for these clusters
via the cosmological Limber equation. The correlation lengths that we measure
for clusters in the LCDCS are consistent both with local results for the APM
cluster catalog and with theoretical expectations based upon the Virgo
Consortium Hubble Volume simulations and the analytic predictions. Despite
samples containing over 100 clusters, our ability to discriminate between
cosmological models is limited because of statistical uncertainty.Comment: 7 pages, 4 figures, accepted to ApJ (v571, May 20, 2002
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