156 research outputs found
Type Ia Supernovae, Evolution, and the Cosmological Constant
We explore the possible role of evolution in the analysis of data on SNe Ia
at cosmological distances. First, using a variety of simple sleuthing
techniques, we find evidence that the properties of the high and low redshift
SNe Ia observed so far differ from one another. Next, we examine the effects of
including simple phenomenological models for evolution in the analysis. The
result is that cosmological models and evolution are highly degenerate with one
another, so that the incorporation of even very simple models for evolution
makes it virtually impossible to pin down the values of and
, the density parameters for nonrelativistic matter and for the
cosmological constant, respectively. Moreover, we show that if SNe Ia evolve
with time, but evolution is neglected in analyzing data, then, given enough SNe
Ia, the analysis hones in on values of and which
are incorrect. Using Bayesian methods, we show that the probability that the
cosmological constant is nonzero (rather than zero) is unchanged by the SNe Ia
data when one accounts for the possibility of evolution, provided that we do
not discriminate among open, closed and flat cosmologies a priori. The case for
nonzero cosmological constant is stronger if the Universe is presumed to be
flat, but still depends sensitively on the degree to which the peak
luminosities of SNe Ia evolve as a function of redshift. The estimated value of
, however, is only negligibly affected by accounting for possible
evolution.Comment: 45 pages, 15 figures; accepted for publication in The Astrophysical
Journal. Minor revisions and clarifications made including addition of recent
reference
Growth, profits and technological choice: The case of the Lancashire cotton textile industry
Using Lancashire textile industry company case studies and financial records, mainly from the period just before the First World War, the processes of growth and decline are re-examined. These are considered by reference to the nature of Lancashire entrepreneurship and the impact on technological choice. Capital accumulation, associated wealth distributions and the character of Lancashire business organisation were sybiotically linked to the success of the industry before 1914. However, the legacy of that accumulation in later decades, chronic overcapacity, formed a barrier to reconstruction and enhanced the preciptious decline of a once great industry
An Integrated TCGA Pan-Cancer Clinical Data Resource to Drive High-Quality Survival Outcome Analytics
For a decade, The Cancer Genome Atlas (TCGA) program collected clinicopathologic annotation data along with multi-platform molecular profiles of more than 11,000 human tumors across 33 different cancer types. TCGA clinical data contain key features representing the democratized nature of the data collection process. To ensure proper use of this large clinical dataset associated with genomic features, we developed a standardized dataset named the TCGA Pan-Cancer Clinical Data Resource (TCGA-CDR), which includes four major clinical outcome endpoints. In addition to detailing major challenges and statistical limitations encountered during the effort of integrating the acquired clinical data, we present a summary that includes endpoint usage recommendations for each cancer type. These TCGA-CDR findings appear to be consistent with cancer genomics studies independent of the TCGA effort and provide opportunities for investigating cancer biology using clinical correlates at an unprecedented scale. Analysis of clinicopathologic annotations for over 11,000 cancer patients in the TCGA program leads to the generation of TCGA Clinical Data Resource, which provides recommendations of clinical outcome endpoint usage for 33 cancer types
Structure-Based Vaccines Provide Protection in a Mouse Model of Ehrlichiosis
infection. were protected against the pathogen.Our results demonstrate the power of structural vaccines and could be a new strategy in the development of vaccines to provide protection against pathogenic microorganisms
Genomic, Pathway Network, and Immunologic Features Distinguishing Squamous Carcinomas
This integrated, multiplatform PanCancer Atlas study co-mapped and identified distinguishing
molecular features of squamous cell carcinomas (SCCs) from five sites associated with smokin
Pan-Cancer Analysis of lncRNA Regulation Supports Their Targeting of Cancer Genes in Each Tumor Context
Long noncoding RNAs (lncRNAs) are commonly dys-regulated in tumors, but only a handful are known toplay pathophysiological roles in cancer. We inferredlncRNAs that dysregulate cancer pathways, onco-genes, and tumor suppressors (cancer genes) bymodeling their effects on the activity of transcriptionfactors, RNA-binding proteins, and microRNAs in5,185 TCGA tumors and 1,019 ENCODE assays.Our predictions included hundreds of candidateonco- and tumor-suppressor lncRNAs (cancerlncRNAs) whose somatic alterations account for thedysregulation of dozens of cancer genes and path-ways in each of 14 tumor contexts. To demonstrateproof of concept, we showed that perturbations tar-geting OIP5-AS1 (an inferred tumor suppressor) andTUG1 and WT1-AS (inferred onco-lncRNAs) dysre-gulated cancer genes and altered proliferation ofbreast and gynecologic cancer cells. Our analysis in-dicates that, although most lncRNAs are dysregu-lated in a tumor-specific manner, some, includingOIP5-AS1, TUG1, NEAT1, MEG3, and TSIX, synergis-tically dysregulate cancer pathways in multiple tumorcontexts
Spatial Organization and Molecular Correlation of Tumor-Infiltrating Lymphocytes Using Deep Learning on Pathology Images
Beyond sample curation and basic pathologic characterization, the digitized H&E-stained images
of TCGA samples remain underutilized. To highlight this resource, we present mappings of tumorinfiltrating lymphocytes (TILs) based on H&E images from 13 TCGA tumor types. These TIL
maps are derived through computational staining using a convolutional neural network trained to
classify patches of images. Affinity propagation revealed local spatial structure in TIL patterns and
correlation with overall survival. TIL map structural patterns were grouped using standard
histopathological parameters. These patterns are enriched in particular T cell subpopulations
derived from molecular measures. TIL densities and spatial structure were differentially enriched
among tumor types, immune subtypes, and tumor molecular subtypes, implying that spatial
infiltrate state could reflect particular tumor cell aberration states. Obtaining spatial lymphocytic
patterns linked to the rich genomic characterization of TCGA samples demonstrates one use for
the TCGA image archives with insights into the tumor-immune microenvironment
Pan-cancer Alterations of the MYC Oncogene and Its Proximal Network across the Cancer Genome Atlas
Although theMYConcogene has been implicated incancer, a systematic assessment of alterations ofMYC, related transcription factors, and co-regulatoryproteins, forming the proximal MYC network (PMN),across human cancers is lacking. Using computa-tional approaches, we define genomic and proteo-mic features associated with MYC and the PMNacross the 33 cancers of The Cancer Genome Atlas.Pan-cancer, 28% of all samples had at least one ofthe MYC paralogs amplified. In contrast, the MYCantagonists MGA and MNT were the most frequentlymutated or deleted members, proposing a roleas tumor suppressors.MYCalterations were mutu-ally exclusive withPIK3CA,PTEN,APC,orBRAFalterations, suggesting that MYC is a distinct onco-genic driver. Expression analysis revealed MYC-associated pathways in tumor subtypes, such asimmune response and growth factor signaling; chro-matin, translation, and DNA replication/repair wereconserved pan-cancer. This analysis reveals insightsinto MYC biology and is a reference for biomarkersand therapeutics for cancers with alterations ofMYC or the PMN
Bayesian analysis of neutrinos observed from supernova SN 1987A
We present a Bayesian analysis of the energies and arrival times of the
neutrinos from supernova SN 1987A detected by the Kamiokande II, IMB, and
Baksan detectors, and find strong evidence for two components in the neutrino
signal: a long time scale component from thermal Kelvin-Helmholtz cooling of
the nascent neutron star, and a brief (~< 1 s), softer component similar to
that expected from emission by accreting material in the delayed supernova
scenario. In the context of this model, we show that the data constrain the
electron antineutrino rest mass to be less than 5.7 eV with 95% probability.
Our analysis takes advantage of significant advances that have occured in the
years since the detections in both our understanding of the supernova mechanism
and our ability to analyze sparse data. As a result there are substantial
differences between our inferences and those found in earlier studies. We find
that two-component models for the neutrino signal make the data >100 times more
probable than single-component models. In addition, the radius and binding
energy of the nascent neutron star implied by single-component models deviates
significantly from the values predicted by current neutron star models, whereas
those implied by models with an accretion component are in complete agreement
with the predictions. As a result, two-component models are hundreds to
thousands of times more probable than single-component models. The neutrino
data thus provide the first direct observational evidence in favor of the
delayed supernova scenario over the prompt scenario. (Abridged abstract)Comment: 46 pages, 12 figures, RevTeX; for submission to Physical Review
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