158 research outputs found
Gluing construction of initial data with Kerr-de Sitter ends
We construct initial data sets which satisfy the vacuum constraint equa-
tions of General Relativity with positive cosmologigal constant. More pre-
silely, we deform initial data with ends asymptotic to Schwarzschild-de Sitter
to obtain non-trivial initial data with exactly Kerr-de Sitter ends. The method
is inspired from Corvino's gluing method. We obtain here a extension of a
previous result for the time-symmetric case by Chru\'sciel and Pollack.Comment: 27 pages, 3 figure
Constraints on the Variations of the Fundamental Couplings
We reconsider several current bounds on the variation of the fine-structure
constant in models where all gauge and Yukawa couplings vary in an
interdependent manner, as would be expected in unified theories. In particular,
we re-examine the bounds established by the Oklo reactor from the resonant
neutron capture cross-section of 149Sm. By imposing variations in \Lambda_{QCD}
and the quark masses, as dictated by unified theories, the corresponding bound
on the variation of the fine-structure constant can be improved by about 2
orders of magnitude in such theories. In addition, we consider possible bounds
on variations due to their effect on long lived \alpha- and \beta-decay
isotopes, particularly 147Sm and 187Re. We obtain a strong constraint on \Delta
\alpha / \alpha, comparable to that of Oklo but extending to a higher redshift
corresponding to the age of the solar system, from the radioactive life-time of
187Re derived from meteoritic studies. We also analyze the astrophysical
consequences of perturbing the decay Q values on bound state \beta-decays
operating in the s-process.Comment: 25 pages, latex, 5 eps figure
Quantum Attractor Flows
Motivated by the interpretation of the Ooguri-Strominger-Vafa conjecture as a
holographic correspondence in the mini-superspace approximation, we study the
radial quantization of stationary, spherically symmetric black holes in four
dimensions. A key ingredient is the classical equivalence between the radial
evolution equation and geodesic motion of a fiducial particle on the moduli
space M^*_3 of the three-dimensional theory after reduction along the time
direction. In the case of N=2 supergravity, M^*_3 is a para-quaternionic-Kahler
manifold; in this case, we show that BPS black holes correspond to a particular
class of geodesics which lift holomorphically to the twistor space Z of M^*_3,
and identify Z as the BPS phase space. We give a natural quantization of the
BPS phase space in terms of the sheaf cohomology of Z, and compute the exact
wave function of a BPS black hole with fixed electric and magnetic charges in
this framework. We comment on the relation to the topological string amplitude,
extensions to N>2 supergravity theories, and applications to automorphic black
hole partition functions.Comment: 43 pages, 6 figures; v2: typos and references added; v3: published
version, minor change
Second-generation colon capsule endoscopy compared with colonoscopy
Colon capsule endoscopy (CCE) represents a noninvasive technology
that allows visualization of the colon without requiring sedation and air
insufflation. A second-generation colon capsule endoscopy system (PillCam Colon
2) (CCE-2) was developed to increase sensitivity for colorectal polyp detection
compared with the first-generation system. OBJECTIVE: To assess the feasibility,
accuracy, and safety of CCE-2 in a head-to-head comparison with colonoscopy.
DESIGN AND SETTING: Prospective, multicenter trial including 8 European sites.
PATIENTS: This study involved 117 patients (mean age 60 years). Data from 109
patients were analyzed. INTERVENTION: CCE-2 was prospectively compared with
conventional colonoscopy as the criterion standard for the detection of
colorectal polyps that are >/=6 mm or masses in a cohort of patients at average
or increased risk of colorectal neoplasia. Colonoscopy was independently
performed within 10 hours after capsule ingestion or on the next day. MAIN
OUTCOME MEASUREMENTS: CCE-2 sensitivity and specificity for detecting patients
with polyps >/=6 mm and >/=10 mm were assessed. Capsule-positive but
colonoscopy-negative cases were counted as false positive. Capsule excretion
rate, level of bowel preparation, and rate of adverse events also were assessed.
RESULTS: Per-patient CCE-2 sensitivity for polyps >/=6 mm and >/=10 mm was 84%
and 88%, with specificities of 64% and 95%, respectively. All 3 invasive
carcinomas were detected by CCE-2. The capsule excretion rate was 88% within 10
hours. Overall colon cleanliness for CCE-2 was adequate in 81% of patients.
LIMITATIONS: Not unblinding the CCE-2 results at colonoscopy; heterogenous
patient population; nonconsecutive patients. CONCLUSION: In this European,
multicenter study, CCE-2 appeared to have a high sensitivity for the detection of
clinically relevant polypoid lesions, and it might be considered an adequate tool
for colorectal imaging
Meta-analysis identifies seven susceptibility loci involved in the atopic March
Eczema often precedes the development of asthma in a disease course called the a 'atopic march'. To unravel the genes underlying this characteristic pattern of allergic disease, we conduct a multi-stage genome-wide association study on infantile eczema followed by childhood asthma in 12 populations including 2,428 cases and 17,034 controls. Here we report two novel loci specific for the combined eczema plus asthma phenotype, which are associated with allergic disease for the first time; rs9357733 located in EFHC1 on chromosome 6p12.3 (OR 1.27; P=2.1 Ă 10 a'8) and rs993226 between TMTC2 and SLC6A15 on chromosome 12q21.3 (OR 1.58; P=5.3 Ă 10 a'9). Additional susceptibility loci identified
Meta-analysis of Genome-Wide Association Studies for Extraversion: Findings from the Genetics of Personality Consortium
Extraversion is a relatively stable and heritable personality trait associated with numerous psychosocial, lifestyle and health outcomes. Despite its substantial heritability, no genetic variants have been detected in previous genome-wide association (GWA) studies, which may be due to relatively small sample sizes of those studies. Here, we report on a large meta-analysis of GWA studies for extraversion in 63,030 subjects in 29 cohorts. Extraversion item data from multiple personality inventories were harmonized across inventories and cohorts. No genome-wide significant associations were found at the single nucleotide polymorphism (SNP) level but there was one significant hit at the gene level for a long non-coding RNA site (LOC101928162). Genome-wide complex trait analysis in two large cohorts showed that the additive variance explained by common SNPs was not significantly different from zero, but polygenic risk scores, weighted using linkage information, significantly predicted extraversion scores in an independent cohort. These results show that extraversion is a highly polygenic personality trait, with an architecture possibly different from other complex human traits, including other personality traits. Future studies are required to further determine which genetic variants, by what modes of gene action, constitute the heritable nature of extraversion
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