2,425 research outputs found
Does Unilateral DIPNECH Provide Clues to Pathogenesis?
Digitalitzat per Artypla
QSO clustering and the AAT 2dF redshift survey
We review previous results on the clustering and environments of QSOs. We
show that the correlation length for QSOs derived from existing surveys is
r~5/h Mpc, similar to the observed correlation length for field galaxies at the
present epoch. The galaxy environment for z<1 radio-quiet QSOs is also
consistent with field galaxies. The evolution of the QSO correlation length
with redshift is currently uncertain, largely due to the small numbers of QSOs
(~2000) in surveys suitable for clustering analysis. We report on intial
progress with the AAT 2dF QSO redshift survey, which, once completed will
comprise almost 30000 QSOs. With over 1000 QSOs already observed, it is already
the largest single homogeneous QSO survey. We discuss prospects for deriving
limits on cosmological parameters from this survey, and on the evolution of
large-scale structure in the Universe.Comment: Invited talk at RS meeting on 'Large Scale Structure in the Universe'
held at the Royal Society on 25-26 March 1998 14 pages, 11 figre
Unlocking biomarker discovery: Large scale application of aptamer proteomic technology for early detection of lung cancer
Lung cancer is the leading cause of cancer deaths, because ~84% of cases are diagnosed at an advanced stage. Worldwide in 2008, ~1.5 million people were diagnosed and ~1.3 million died – a survival rate unchanged since 1960. However, patients diagnosed at an early stage and have surgery experience an 86% overall 5-year survival. New diagnostics are therefore needed to identify lung cancer at this stage. Here we present the first large scale clinical use of aptamers to discover blood protein biomarkers in disease with our breakthrough proteomic technology. This multi-center case-control study was conducted in archived samples from 1,326 subjects from four independent studies of non-small cell lung cancer (NSCLC) in long-term tobacco-exposed populations. We measured >800 proteins in 15uL of serum, identified 44 candidate biomarkers, and developed a 12-protein panel that distinguished NSCLC from controls with 91% sensitivity and 84% specificity in a training set and 89% sensitivity and 83% specificity in a blinded, independent verification set. Performance was similar for early and late stage NSCLC. This is a significant advance in proteomics in an area of high clinical need
Lung cancer induced in mice by the envelope protein of jaagsiekte sheep retrovirus (JSRV) closely resembles lung cancer in sheep infected with JSRV
BACKGROUND: Jaagsiekte sheep retrovirus (JSRV) causes a lethal lung cancer in sheep and goats. Expression of the JSRV envelope (Env) protein in mouse lung, by using a replication-defective adeno-associated virus type 6 (AAV6) vector, induces tumors resembling those seen in sheep. However, the mouse and sheep tumors have not been carefully compared to determine if Env expression alone in mice can account for the disease features observed in sheep, or whether additional aspects of virus replication in sheep are important, such as oncogene activation following retrovirus integration into the host cell genome. RESULTS: We have generated mouse monoclonal antibodies (Mab) against JSRV Env and have used these to study mouse and sheep lung tumor histology. These Mab detect Env expression in tumors in sheep infected with JSRV from around the world with high sensitivity and specificity. Mouse and sheep tumors consisted mainly of well-differentiated adenomatous foci with little histological evidence of anaplasia, but at long times after vector exposure some mouse tumors did have a more malignant appearance typical of adenocarcinoma. In addition to epithelial cell tumors, lungs of three of 29 sheep examined contained fibroblastic cell masses that expressed Env and appeared to be separate neoplasms. The Mab also stained nasal adenocarcinoma tissue from one United States sheep, which we show was due to expression of Env from ovine enzootic nasal tumor virus (ENTV), a virus closely related to JSRV. Systemic administration of the AAV6 vector encoding JSRV Env to mice produced numerous hepatocellular tumors, and some hemangiomas and hemangiosarcomas, showing that the Env protein can induce tumors in multiple cell types. CONCLUSION: Lung cancers induced by JSRV infection in sheep and by JSRV Env expression in mice have similar histologic features and are primarily characterized by adenomatous proliferation of peripheral lung epithelial cells. Thus it is unnecessary to invoke a role for insertional mutagenesis, gene activation, viral replication, or expression of other viral gene products in sheep lung tumorigenesis, although these processes may play a role in other clinically less important sequelae of JSRV infection such as metastasis observed with variable frequency in sheep
The Evolution of Distorted Rotating Black Holes II: Dynamics and Analysis
We have developed a numerical code to study the evolution of distorted,
rotating black holes. This code is used to evolve a new family of black hole
initial data sets corresponding to distorted ``Kerr'' holes with a wide range
of rotation parameters, and distorted Schwarzschild black holes with odd-parity
radiation. Rotating black holes with rotation parameters as high as
are evolved and analyzed in this paper. The evolutions are generally carried
out to about , where is the ADM mass. We have extracted both the
even- and odd-parity gravitational waveforms, and find the quasinormal modes of
the holes to be excited in all cases. We also track the apparent horizons of
the black holes, and find them to be a useful tool for interpreting the
numerical results. We are able to compute the masses of the black holes from
the measurements of their apparent horizons, as well as the total energy
radiated and find their sum to be in excellent agreement with the ADM mass.Comment: 26 pages, LaTeX with RevTeX 3.0 macros. 27 uuencoded gz-compressed
postscript figures. Also available at http://jean-luc.ncsa.uiuc.edu/Papers/
Submitted to Physical Review
Disclosing the Radio Loudness Distribution Dichotomy in Quasars: An Unbiased Monte Carlo Approach Applied to the SDSS-FIRST Quasar Sample
We investigate the dichotomy in the radio loudness distribution of quasars by
modelling their radio emission and various selection effects using a Monte
Carlo approach. The existence of two physically distinct quasar populations,
the radio-loud and radio-quiet quasars, is controversial and over the last
decade a bimodal distribution of radio loudness of quasars has been both
affirmed and disputed. We model the quasar radio luminosity distribution with
simple unimodal and bimodal distribution functions. The resulting simulated
samples are compared to a fiducial sample of 8,300 quasars drawn from the SDSS
DR7 Quasar Catalog and combined with radio observations from the FIRST survey.
Our results indicate that the SDSS-FIRST sample is best described by a radio
loudness distribution which consists of two components, with 12+/-1 % of
sources in the radio-loud component. On the other hand, the evidence for a
local minimum in the loudness distribution (bimodality) is not strong and we
find that previous claims for its existence were probably affected by the
incompleteness of the FIRST survey close to its faint limit. We also
investigate the redshift and luminosity dependence of the radio loudness
distribution and find tentative evidence that at high redshift radio-loud
quasars were rarer, on average "louder", and exhibited a smaller range in radio
loudness. In agreement with other recent work, we conclude that the SDSS-FIRST
sample strongly suggests that the radio loudness distribution of quasars is not
a universal function, and that more complex models than presented here are
needed to fully explain available observations.Comment: Accepted for publication in ApJ; 13 pages, 10 figure
The constraints as evolution equations for numerical relativity
The Einstein equations have proven surprisingly difficult to solve
numerically. A standard diagnostic of the problems which plague the field is
the failure of computational schemes to satisfy the constraints, which are
known to be mathematically conserved by the evolution equations. We describe a
new approach to rewriting the constraints as first-order evolution equations,
thereby guaranteeing that they are satisfied to a chosen accuracy by any
discretization scheme. This introduces a set of four subsidiary constraints
which are far simpler than the standard constraint equations, and which should
be more easily conserved in computational applications. We explore the manner
in which the momentum constraints are already incorporated in several existing
formulations of the Einstein equations, and demonstrate the ease with which our
new constraint-conserving approach can be incorporated into these schemes.Comment: 10 pages, updated to match published versio
An Optical Catalog of Galaxy Clusters Obtained from an Adaptive Matched Filter Finder Applied to SDSS DR6
We present a new cluster catalog extracted from the Sloan Digital Sky Survey
Data Release 6 (SDSS DR6) using an adaptive matched filter (AMF) cluster
finder. We identify 69,173 galaxy clusters in the redshift range 0.045 0.78 in 8420 sq. deg. of the sky. We provide angular position, redshift,
richness, core and virial radii estimates for these clusters, as well as an
error analysis for each of these quantities. We also provide a catalog of more
than 205,000 galaxies representing the three brightest galaxies in the band
which are possible BCG candidates. We show basic properties of the BCG
candidates and study how their luminosity scales in redshift and cluster
richness. We compare our catalog with the maxBCG and GMBCG catalogs, as well as
with that of Wen, Han, and Liu. We match between 30% and 50% of clusters
between catalogs over all overlapping redshift ranges. We find that the
percentage of matches increases with the richness for all catalogs. We cross
match the AMF catalog with available X-ray data in the same area of the sky and
find 539 matches, 119 of which with temperature measurements. We present
scaling relations between optical and X-ray properties and cluster center
comparison. We find that both and correlate well with
both and , with no significant difference in trend if we restrict
the matches to flux-limited X-ray samples.Comment: 59 pages, 28 figures; accepted for publication in The Astrophysical
Journa
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