104 research outputs found
Probabilities of Large Earthquakes in the San Francisco Bay Region, California
In 1987 a Working Group on California Earthquake Probabilities was organized by the U.S. Geological
Survey at the recommendation of the National Earthquake Prediction Evaluation Council (NEPEC). The
membership included representatives from private industry, academia, and the U.S. Geological Survey. The
Working Group computed long-term probabilities of earthquakes along the major faults of the San Andreas
fault system on the basis of consensus interpretations of information then available. Faults considered by the
Working Group included the San Andreas fault proper, the San Jacinto and Imperial-faults of southern
California, and the Hayward fault of northern California. The Working Group issued a final report of its
findings in 1988 (Working Group, 1988) that was reviewed and endorsed by NEPEC.
As a consequence of the magnitude 7.1 Loma Prieta, California, earthquake of October 17, 1989, a
second Working Group on California Earthquake Probabilities was organized under the auspices of NEPEC.
Its charge was to review and, as necessary, revise the findings of the 1988 report on the probability of large
earthquakes in the San Francisco Bay region. In particular, the Working Group was requested to examine the
probabilities of large earthquakes in the context of new interpretations or physical changes resulting from the
Loma Prieta earthquake. In addition, it was to consider new information pertaining to the San Andreas and other
faults in the region obtained subsequent to the release of the 1988 report. Insofar as modified techniques and
improved data have been used in this study, the same approach might also, of course, modify the probabilities
for southern California. This reevaluation has, however, been specifically limited to the San Francisco Bay
region.
This report is intended to summarize the collective knowledge and judgments of a diverse group of
earthquake scientists to assist in formulation of rational earthquake policies. A considerable body of information
about active faults in the San Francisco Bay region leads to the conclusion that major earthquakes are likely
within the next tens of years. Several techniques can be used to compute probabilities of future earthquakes,
although there are uncertainties about the validity of specific assumptions or models that must be made when
applying these techniques. The body of this report describes the data and detailed assumptions that lead to
specific probabilities for different fault segments. Additional data and future advances in our understanding of
earthquake physics may alter the way that these probabilities are estimated. Even though this uncertainty must
be acknowledged, we emphasize that the findings of this report are supported by other lines of argument and
are consistent with our best understanding of the likelihood for the occurrence of earthquakes in the San
Francisco Bay region
V2494 cyg: A unique FU ori type object in the cygnus OB7 complex
A photometric and spectral study of the variable star V2494 Cyg in the L 1003 dark cloud is presented. The brightness of the star, formerly known as HH 381 IRS, increased by 2.5 mag in R (probably in the 1980s) and since then has remained nearly constant. Since the brightness increase, V2494 Cyg has illuminated a bipolar cometary nebula. The stellar spectrum has several features typical of the FU Ori (FUor) type, plus it exhibits very strong Ha and forbidden emissionlines with high-velocity components. These emission lines originate in the Herbig-Haro (HH) jet near the star. The kinematic age of the jet is consistent with it forming at the time of the outburst leading to the luminosity increase. V2494 Cyg also produces a rather extended outflow; it is the first known FUor with both an observed outburst and a parsec-sized HH flow. The nebula, illuminated by V2494 Cyg, possesses similar morphological and spectral characteristics to Hubble's variable nebula (R Monocerotis/NGC 2261). © 2013 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society
Detection of massive tidal tails around the globular cluster Pal 5 with SDSS commissioning data
We report the discovery of two well-defined tidal tails emerging from the
sparse remote globular cluster Palomar 5. These tails stretch out symmetrically
to both sides of the cluster in the direction of constant Galactic latitude and
subtend an angle of 2.6 degrees on the sky. The tails have been detected in
commissioning data of the Sloan Digital Sky Survey (SDSS), providing deep
five-color photometry in a 2.5 degrees wide band along the equator. The stars
in the tails make up a substantial part (~1/3) of the current total population
of cluster stars in the magnitude interval 19.5 < i* < 22.0. This reveals that
the cluster is subject to heavy mass loss. The orientation of the tails
provides an important key for the determination of the cluster's Galactic
orbit.Comment: 7 pages, 3 postscript figures, accepted for publication in ApJ
Letter
The Seventh Data Release of the Sloan Digital Sky Survey
This paper describes the Seventh Data Release of the Sloan Digital Sky Survey
(SDSS), marking the completion of the original goals of the SDSS and the end of
the phase known as SDSS-II. It includes 11663 deg^2 of imaging data, with most
of the roughly 2000 deg^2 increment over the previous data release lying in
regions of low Galactic latitude. The catalog contains five-band photometry for
357 million distinct objects. The survey also includes repeat photometry over
250 deg^2 along the Celestial Equator in the Southern Galactic Cap. A
coaddition of these data goes roughly two magnitudes fainter than the main
survey. The spectroscopy is now complete over a contiguous area of 7500 deg^2
in the Northern Galactic Cap, closing the gap that was present in previous data
releases. There are over 1.6 million spectra in total, including 930,000
galaxies, 120,000 quasars, and 460,000 stars. The data release includes
improved stellar photometry at low Galactic latitude. The astrometry has all
been recalibrated with the second version of the USNO CCD Astrograph Catalog
(UCAC-2), reducing the rms statistical errors at the bright end to 45
milli-arcseconds per coordinate. A systematic error in bright galaxy photometr
is less severe than previously reported for the majority of galaxies. Finally,
we describe a series of improvements to the spectroscopic reductions, including
better flat-fielding and improved wavelength calibration at the blue end,
better processing of objects with extremely strong narrow emission lines, and
an improved determination of stellar metallicities. (Abridged)Comment: 20 pages, 10 embedded figures. Accepted to ApJS after minor
correction
Meta-analysis uncovers genome-wide significant variants for rapid kidney function decline
Rapid decline of glomerular filtration rate estimated from creatinine (eGFRcrea) is associated with severe clinical endpoints. In contrast to cross-sectionally assessed eGFRcrea, the genetic basis for rapid eGFRcrea decline is largely unknown. To help define this, we meta-analyzed 42 genome-wide association studies from the Chronic Kidney Diseases Genetics Consortium and United Kingdom Biobank to identify genetic loci for rapid eGFRcrea decline. Two definitions of eGFRcrea decline were used: 3 mL/min/1.73m(2)/year or more ("Rapid3"; encompassing 34,874 cases, 107,090 controls) and eGFRcrea decline 25% or more and eGFRcrea under 60 mL/min/1.73m(2) at follow-up among those with eGFRcrea 60 mL/min/1.73m(2) or more at baseline ("CKDi25"; encompassing 19,901 cases, 175,244 controls). Seven independent variants were identified across six loci for Rapid3 and/or CKDi25: consisting of five variants at four loci with genome-wide significance (near UMOD-PDILT (2), PRKAG2, WDR72, OR2S2) and two variants among 265 known eGFRcrea variants (near GATM, LARP4B). All these loci were novel for Rapid3 and/or CKDi25 and our bioinformatic follow-up prioritized variants and genes underneath these loci. The OR2S2 locus is novel for any eGFRcrea trait including interesting candidates. For the five genome-wide significant lead variants, we found supporting effects for annual change in blood urea nitrogen or cystatin-based eGFR, but not for GATM or (LARP4B). Individuals at high compared to those at low genetic risk (8-14 vs. 0-5 adverse alleles) had a 1.20-fold increased risk of acute kidney injury (95% confidence interval 1.08-1.33). Thus, our identified loci for rapid kidney function decline may help prioritize therapeutic targets and identify mechanisms and individuals at risk for sustained deterioration of kidney function
Regulatory subunits of PKA define an axis of cellular proliferation/differentiation in ovarian cancer cells
<p>Abstract</p> <p>Background</p> <p>The regulatory subunit of cAMP-dependent protein kinase (PKA) exists in two isoforms, RI and RII, which distinguish the PKA isozymes, type I (PKA-I) and type II (PKA-II). Evidence obtained from a variety of different experimental approaches has shown that the relative levels of type I and type II PKA in cells can play a major role in determining the balance between cell growth and differentiation. In order to characterize the effect of PKA type I and type II regulatory subunits on gene transcription at a global level, the PKA regulatory subunit genes for RIα and RIIβ were stably transfected into cells of the ovarian cancer cell line (OVCAR8).</p> <p>Results</p> <p>RIα transfected cells exhibit hyper-proliferative growth and RIIβ transfected cells revert to a relatively quiescent state. Profiling by microarray revealed equally profound changes in gene expression between RIα, RIIβ, and parental OVCAR cells. Genes specifically up-regulated in RIα cells were highly enriched for pathways involved in cell growth while genes up-regulated in RIIβ cells were enriched for pathways involved in differentiation. A large group of genes (~3600) was regulated along an axis of proliferation/differentiation between RIα, parental, and RIIβ cells. RIα/wt and RIIβ/wt gene regulation was shown by two separate and distinct gene set analytical methods to be strongly cross-correlated with a generic model of cellular differentiation.</p> <p>Conclusion</p> <p>Overexpression of PKA regulatory subunits in an ovarian cancer cell line dramatically influences the cell phenotype. The proliferation phenotype is strongly correlated with recently identified clinical biomarkers predictive of poor prognosis in ovarian cancer suggesting a possible pivotal role for PKA regulation in disease progression.</p
Genomic and transcriptomic changes complement each other in the pathogenesis of sporadic Burkitt lymphoma
Burkitt lymphoma (BL) is the most common B-cell lymphoma in children. Within the International Cancer Genome Consortium (ICGC), we performed whole genome and transcriptome sequencing of 39 sporadic BL. Here, we unravel interaction of structural, mutational, and transcriptional changes, which contribute to MYC oncogene dysregulation together with the pathognomonic IG-MYC translocation. Moreover, by mapping IGH translocation breakpoints, we provide evidence that the precursor of at least a subset of BL is a B-cell poised to express IGHA. We describe the landscape of mutations, structural variants, and mutational processes, and identified a series of driver genes in the pathogenesis of BL, which can be targeted by various mechanisms, including IG-non MYC translocations, germline and somatic mutations, fusion transcripts, and alternative splicing
Lack of association between the Trp719Arg polymorphism in kinesin-like protein-6 and coronary artery disease in 19 case-control studies
The genomic and transcriptional landscape of primary central nervous system lymphoma
Primary lymphomas of the central nervous system (PCNSL) are mainly diffuse large B-cell lymphomas (DLBCLs) confined to the central nervous system (CNS). Molecular drivers of PCNSL have not been fully elucidated. Here, we profile and compare the whole-genome and transcriptome landscape of 51 CNS lymphomas (CNSL) to 39 follicular lymphoma and 36 DLBCL cases outside the CNS. We find recurrent mutations in JAK-STAT, NFkB, and B-cell receptor signaling pathways, including hallmark mutations in MYD88 L265P (67%) and CD79B (63%), and CDKN2A deletions (83%). PCNSLs exhibit significantly more focal deletions of HLA-D (6p21) locus as a potential mechanism of immune evasion. Mutational signatures correlating with DNA replication and mitosis are significantly enriched in PCNSL. TERT gene expression is significantly higher in PCNSL compared to activated B-cell (ABC)-DLBCL. Transcriptome analysis clearly distinguishes PCNSL and systemic DLBCL into distinct molecular subtypes. Epstein-Barr virus (EBV)+ CNSL cases lack recurrent mutational hotspots apart from IG and HLA-DRB loci. We show that PCNSL can be clearly distinguished from DLBCL, having distinct expression profiles, IG expression and translocation patterns, as well as specific combinations of genetic alterations
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