20 research outputs found
Tracing Ghost Cavities with Low Frequency Radio Observations
We present X-ray and multi-frequency radio observations of the central radio
sources in several X-ray cavity systems. We show that targeted radio
observations are key to determining if the lobes are being actively fed by the
central AGN. Low frequency observations provide a unique way to study both the
lifecycle of the central radio source as well as its energy input into the ICM
over several outburst episodes.Comment: 6 pages, 4 figures, To appear in the Proceedings of "Heating vs.
Cooling in Galaxies and Clusters of Galaxies", eds. H. Boehringer, P.
Schuecker, G. W. Pratt & A. Finoguenov (ESO Astrophysics Symposia,
Springer-Verlag), Garching (Germany), August 200
Non-detection of a statistically anisotropic power spectrum in large-scale structure
We search a sample of photometric luminous red galaxies (LRGs) measured by
the Sloan Digital Sky Survey (SDSS) for a quadrupolar anisotropy in the
primordial power spectrum, in which P(\vec{k}) is an isotropic power spectrum
P(k) multiplied by a quadrupolar modulation pattern. We first place limits on
the 5 coefficients of a general quadrupole anisotropy. We also consider
axisymmetric quadrupoles of the form P(\vec{k}) = P(k){1 +
g_*[(\hat{k}\cdot\hat{n})^2-1/3]} where \hat{n} is the axis of the anisotropy.
When we force the symmetry axis \hat{n} to be in the direction (l,b)=(94
degrees,26 degrees) identified in the recent Groeneboom et al. analysis of the
cosmic microwave background, we find g_*=0.006+/-0.036 (1 sigma). With uniform
priors on \hat{n} and g_* we find that -0.41<g_*<+0.38 with 95% probability,
with the wide range due mainly to the large uncertainty of asymmetries aligned
with the Galactic Plane. In none of these three analyses do we detect evidence
for quadrupolar power anisotropy in large scale structure.Comment: 23 pages; 10 figures; 3 tables; replaced with version published in
JCAP (added discussion of scale-varying quadrupolar anisotropy
Cosmological parameters from SDSS and WMAP
We measure cosmological parameters using the three-dimensional power spectrum
P(k) from over 200,000 galaxies in the Sloan Digital Sky Survey (SDSS) in
combination with WMAP and other data. Our results are consistent with a
``vanilla'' flat adiabatic Lambda-CDM model without tilt (n=1), running tilt,
tensor modes or massive neutrinos. Adding SDSS information more than halves the
WMAP-only error bars on some parameters, tightening 1 sigma constraints on the
Hubble parameter from h~0.74+0.18-0.07 to h~0.70+0.04-0.03, on the matter
density from Omega_m~0.25+/-0.10 to Omega_m~0.30+/-0.04 (1 sigma) and on
neutrino masses from <11 eV to <0.6 eV (95%). SDSS helps even more when
dropping prior assumptions about curvature, neutrinos, tensor modes and the
equation of state. Our results are in substantial agreement with the joint
analysis of WMAP and the 2dF Galaxy Redshift Survey, which is an impressive
consistency check with independent redshift survey data and analysis
techniques. In this paper, we place particular emphasis on clarifying the
physical origin of the constraints, i.e., what we do and do not know when using
different data sets and prior assumptions. For instance, dropping the
assumption that space is perfectly flat, the WMAP-only constraint on the
measured age of the Universe tightens from t0~16.3+2.3-1.8 Gyr to
t0~14.1+1.0-0.9 Gyr by adding SDSS and SN Ia data. Including tensors, running
tilt, neutrino mass and equation of state in the list of free parameters, many
constraints are still quite weak, but future cosmological measurements from
SDSS and other sources should allow these to be substantially tightened.Comment: Minor revisions to match accepted PRD version. SDSS data and ppt
figures available at http://www.hep.upenn.edu/~max/sdsspars.htm
Metal enrichment processes
There are many processes that can transport gas from the galaxies to their
environment and enrich the environment in this way with metals. These metal
enrichment processes have a large influence on the evolution of both the
galaxies and their environment. Various processes can contribute to the gas
transfer: ram-pressure stripping, galactic winds, AGN outflows, galaxy-galaxy
interactions and others. We review their observational evidence, corresponding
simulations, their efficiencies, and their time scales as far as they are known
to date. It seems that all processes can contribute to the enrichment. There is
not a single process that always dominates the enrichment, because the
efficiencies of the processes vary strongly with galaxy and environmental
properties.Comment: 18 pages, 8 figures, accepted for publication in Space Science
Reviews, special issue "Clusters of galaxies: beyond the thermal view",
Editor J.S. Kaastra, Chapter 17; work done by an international team at the
International Space Science Institute (ISSI), Bern, organised by J.S.
Kaastra, A.M. Bykov, S. Schindler & J.A.M. Bleeke
Estimating the global burden of endemic canine rabies
Rabies is a fatal viral disease largely transmitted to humans from bites by infected animals
—predominantly from domestic dogs. The disease is entirely preventable through prompt
administration of post-exposure prophylaxis (PEP) to bite victims and can be controlled
through mass vaccination of domestic dogs. Yet, rabies is still very prevalent in developing
countries, affecting populations with limited access to health care. The disease is also
grossly underreported in these areas because most victims die at home. This leads to insufficient
prioritization of rabies prevention in public health agendas. To address this lack of
information on the impacts of rabies, in this study, we compiled available data to provide a
robust estimate of the health and economic implications of dog rabies globally. The most
important impacts included: loss of human lives (approximately 59,000 annually) and productivity
due to premature death from rabies, and costs of obtaining PEP once an exposure
has occurred. The greatest risk of developing rabies fell upon the poorest regions of the
world, where domestic dog vaccination is not widely implemented and access to PEP is
most limited. A greater focus on mass dog vaccination could eliminate the disease at
source, reducing the need for costly PEP and preventing the large and unnecessary burden
of mortality on at-risk communities.S1 Text. Supporting bibliography.S1 Table. Estimates by country of rabies deaths, exposures, PEP use, prevented deaths, dog
vaccination coverage, probability that a dog is rabid (RP), of bite victims receiving PEP
(PP), DALYs, costs and 95% confidence intervals of estimates. Clusters to which countries
are assigned are shown and inputs used for estimating parameters including the human development
index and whetehr a country s rabies-free or endemic (RISK). Estimates of years of life
lost (YLL) and DALYs (due to rabies and to adverse events from the use of nerve tissue vaccines) are shown under different assumptions (estimates under the assumption of no time
discounting or age-weighting should be directly comparable to the 2010 Global Burden of Disease
study).S1 Fig. Division of costs associated with rabies, prevention and control across sectors by
cluster. Inset shows proportional expenditure in different clusters. Full details of countries by
cluster are given in S1 Table. Asia 4 comprises: Philippines, Sri Lanka, Thailand (High PEP
use); Asia 3 comprises Bhutan, Nepal, Bangladesh, Pakistan (Himalayan region); Asia 2 comprises
Cambodia, Myanmar, Laos, Vietnam and Democratic People’s Republic of Korea;
SADC comprises countries in the Southern African Development Community, Eurasia comprises
Afghanistan, Kazakhstan, Kyrgyzstan, Mongolia, the Russian Federation, Turkmenistan,
Tajikistan, and Uzbekistan.S1 Dataset. Model code and input data files including references, rationale and detail of
Delphi process. The code folder contains seven R scripts: burden_model.R runs the model
using data compiled in burden_1.R, after estimating parameters using: FitCovInc.R, FitPP.R,
and creating Fig 2 (RabiesBurdenFig2.R). The script burden_results.R summarizes findings
using the output of burden_model.R and burden_sensitivity.R runs the sensitivity analyses. The
data folder contains 12 csv files called by the R code for the analyses, and one excel file (Vet.
xlsx) with additional details about the data sources in vcountry2.csv and vcluster2.csv and with
Delphi process estimates for dog vaccination coverage. Data sources are detailed in the relevant
data sources and the details of the sources of data used in the analysis are in the supporting bibliography,
S1 text.This study was funded by the UBS
Optimus Foundation (http://www.ubs.com/optimusfoundation)
and the Wellcome Trust (095787/Z/11/Z).http://www.plosntds.orgam201
Novel genetic loci associated with hippocampal volume
The hippocampal formation is a brain structure integrally involved in episodic memory, spatial navigation, cognition and stress responsiveness. Structural abnormalities in hippocampal volume and shape are found in several common neuropsychiatric disorders. To identify the genetic underpinnings of hippocampal structure here we perform a genome-wide association study (GWAS) of 33,536 individuals and discover six independent loci significantly associated with hippocampal volume, four of them novel. Of the novel loci, three lie within genes (ASTN2, DPP4 and MAST4) and one is found 200 kb upstream of SHH. A hippocampal subfield analysis shows that a locus within the MSRB3 gene shows evidence of a localized effect along the dentate gyrus, subiculum, CA1 and fissure. Further, we show that genetic variants associated with decreased hippocampal volume are also associated with increased risk for Alzheimer's disease (rg =-0.155). Our findings suggest novel biological pathways through which human genetic variation influences hippocampal volume and risk for neuropsychiatric illness
Complement Blockade in Recipients Prevents Delayed Graft Function and Delays Antibody-mediated Rejection in a Nonhuman Primate Model of Kidney Transplantation
Background. Complement activation in kidney transplantation is implicated in the pathogenesis of delayed graft function (DGF). This study evaluated the therapeutic efficacy of high-dose recombinant human C1 esterase inhibitor (rhC1INH) to prevent DGF in a nonhuman primate model of kidney transplantation after brain death and prolonged cold ischemia. Methods. Brain death donors underwent 20 h of conventional management. Procured kidneys were stored on ice for 44-48 h, then transplanted into ABO-compatible major histocompatibility complex-mismatched recipients. Recipients were treated with vehicle (n = 5) or rhC1INH 500 U/kg plus heparin 40 U/kg (n = 8) before reperfusion, 12 h, and 24 h posttransplant. Recipients were followed up for 120 d. Results. Of vehicle-treated recipients, 80% (4 of 5) developed DGF versus 12.5% (1 of 8) rhC1INH-treated recipients (P = 0.015). rhC1INH-treated recipients had faster creatinine recovery, superior urinary output, and reduced urinary neutrophil gelatinase-associated lipocalin and tissue inhibitor of metalloproteinases 2-insulin-like growth factor-binding protein 7 throughout the first week, indicating reduced allograft injury. Treated recipients presented lower postreperfusion plasma interleukin (IL)-6, IL-8, tumor necrosis factor-alpha, and IL-18, lower day 4 monocyte chemoattractant protein 1, and trended toward lower C5. Treated recipients exhibited less C3b/C5b-9 deposition on day 7 biopsies. rhC1INH-treated animals also trended toward prolonged mediated rejection-free survival. Conclusions. Our results recommend high-dose C1INH complement blockade in transplant recipients as an effective strategy to reduce kidney injury and inflammation, prevent DGF, delay antibody-mediated rejection development, and improve transplant outcomes.Nephrolog