713 research outputs found
Advances in Spatial Data Infrastructure, Acquisition, Analysis, Archiving and Dissemination
The authors review recent contributions to the state-of-thescience and benign proliferation of satellite remote sensing, spatial data infrastructure, near-real-time data acquisition, analysis on high performance computing platforms, sapient archiving, multi-modal dissemination and utilization for a wide array of scientific applications. The authors also address advances in Geoinformatics and its growing ubiquity, as evidenced by its inclusion as a focus area within the American Geophysical Union (AGU), European Geosciences Union (EGU), as well as by the evolution of the IEEE Geoscience and Remote Sensing Society's (GRSS) Data Archiving and Distribution Technical Committee (DAD TC)
Neutrino-less Double Beta Decay and Particle Physics
We review the particle physics aspects of neutrino-less double beta decay.
This process can be mediated by light massive Majorana neutrinos (standard
interpretation) or by something else (non-standard interpretations). The
physics potential of both interpretations is summarized and the consequences of
future measurements or improved limits on the half-life of neutrino-less double
beta decay are discussed. We try to cover all proposed alternative realizations
of the decay, including light sterile neutrinos, supersymmetric or left-right
symmetric theories, Majorons, and other exotic possibilities. Ways to
distinguish the mechanisms from one another are discussed. Experimental and
nuclear physics aspects are also briefly touched, alternative processes to
double beta decay are discussed, and an extensive list of references is
provided.Comment: 96 pages, 38 figures. Published versio
Genomic architecture of inflammatory bowel disease in five families with multiple affected individuals.
Currently, the best clinical predictor for inflammatory bowel disease (IBD) is family history. Over 163 sequence variants have been associated with IBD in genome-wide association studies, but they have weak effects and explain only a fraction of the observed heritability. It is expected that additional variants contribute to the genomic architecture of IBD, possibly including rare variants with effect sizes larger than the identified common variants. Here we applied a family study design and sequenced 38 individuals from five families, under the hypothesis that families with multiple IBD-affected individuals harbor one or more risk variants that (i) are shared among affected family members, (ii) are rare and (iii) have substantial effect on disease development. Our analysis revealed not only novel candidate risk variants but also high polygenic risk scores for common known risk variants in four out of the five families. Functional analysis of our top novel variant in the remaining family, a rare missense mutation in the ubiquitin ligase TRIM11, suggests that it leads to increased nuclear factor of kappa light chain enhancer in B-cells (NF-κB) signaling. We conclude that an accumulation of common weak-effect variants accounts for the high incidence of IBD in most, but not all families we analyzed and that a family study design can identify novel rare variants conferring risk for IBD with potentially large effect size, such as the TRIM11 p.H414Y mutation
Star formation towards the Scutum tangent region and the effects of Galactic environment
By positional matching to the catalogue of Galactic Ring Survey molecular
clouds, we have derived distances to 793 Bolocam Galactic Plane Survey (BGPS)
sources out of a possible 806 located within the region defined by Galactic
longitudes l = 28.5 degr to 31.5 degr and latitudes |b| < 1 degr. This section
of the Galactic Plane contains several major features of Galactic structure at
different distances, mainly mid-arm sections of the Perseus and Sagittarius
spiral arms and the tangent of the Scutum-Centarus arm, which is coincident
with the end of the Galactic Long Bar. By utilising the catalogued cloud
distances plus new kinematic distance determinations, we are able to separate
the dense BGPS clumps into these three main line-of-sight components to look
for variations in star-formation properties that might be related to the
different Galactic environments. We find no evidence of any difference in
either the clump mass function or the average clump formation efficiency (CFE)
between these components that might be attributed to environmental effects on
scales comparable to Galactic-structure features.
Despite having a very high star-formation rate, and containing at least one
cloud with a very high CFE, the star formation associated with the
Scutum-Centarus tangent does not appear to be in any way abnormal or different
to that in the other two spiral-arm sections. Large variations in the CFE are
found on the scale of individual clouds, however, which may be due to local
triggering agents as opposed to the large-scale Galactic structure.Comment: 11 pages, 8 figures. Accepted for publication in the Monthly Notices
of the Royal Astronomical Societ
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Ulcerative colitis-risk loci on chromosomes 1p36 and 12q15 found by genome-wide association study.
Ulcerative colitis is a chronic inflammatory disease of the colon that presents as diarrhea and gastrointestinal bleeding. We performed a genome-wide association study using DNA samples from 1,052 individuals with ulcerative colitis and preexisting data from 2,571 controls, all of European ancestry. In an analysis that controlled for gender and population structure, ulcerative colitis loci attaining genome-wide significance and subsequent replication in two independent populations were identified on chromosomes 1p36 (rs6426833, combined P = 5.1 x 10(-13), combined odds ratio OR = 0.73) and 12q15 (rs1558744, combined P = 2.5 x 10(-12), combined OR = 1.35). In addition, combined genome-wide significant evidence for association was found in a region spanning BTNL2 to HLA-DQB1 on chromosome 6p21 (rs2395185, combined P = 1.0 x 10(-16), combined OR = 0.66) and at the IL23R locus on chromosome 1p31 (rs11209026, combined P = 1.3 x 10(-8), combined OR = 0.56; rs10889677, combined P = 1.3 x 10(-8), combined OR = 1.29)
Proceedings of the 2nd Workshop on Flavor Symmetries and Consequences in Accelerators and Cosmology (FLASY12)
These are the proceedings of the 2nd Workshop on Flavor Symmetries and
Consequences in Accelerators and Cosmology, held 30 June 2012 - 4 July 2012,
Dortmund, Germany.Comment: Order 400 pages, several figures including the group picture v2:
corrected author list and contributio
Suppression of the vacuum space-charge effect in fs-photoemission by a retarding electrostatic front lens
The performance of time-resolved photoemission experiments at fs-pulsed photon sources is ultimately limited by the e–e Coulomb interaction, downgrading energy and momentum resolution. Here, we present an approach to effectively suppress space-charge artifacts in momentum microscopes and photoemission microscopes. A retarding electrostatic field generated by a special objective lens repels slow electrons, retaining the k-image of the fast photoelectrons. The suppression of space-charge effects scales with the ratio of the photoelectron velocities of fast and slow electrons. Fields in the range from −20 to −1100 V/mm for Ekin = 100 eV to 4 keV direct secondaries and pump-induced slow electrons back to the sample surface. Ray tracing simulations reveal that this happens within the first 40 to 3 μm above the sample surface for Ekin = 100 eV to 4 keV. An optimized front-lens design allows switching between the conventional accelerating and the new retarding mode. Time-resolved experiments at Ekin = 107 eV using fs extreme ultraviolet probe pulses from the free-electron laser FLASH reveal that the width of the Fermi edge increases by just 30 meV at an incident pump fluence of 22 mJ/cm2 (retarding field −21 V/mm). For an accelerating field of +2 kV/mm and a pump fluence of only 5 mJ/cm2, it increases by 0.5 eV (pump wavelength 1030 nm). At the given conditions, the suppression mode permits increasing the slow-electron yield by three to four orders of magnitude. The feasibility of the method at high energies is demonstrated without a pump beam at Ekin = 3830 eV using hard x rays from the storage ring PETRA III. The approach opens up a previously inaccessible regime of pump fluences for photoemission experiments
A frameshift mutation in NOD2 associated with susceptibility to Crohn's disease
Crohn's disease is a chronic inflammatory disorder of the gastrointestinal tract, which is thought to result from the effect of environmental factors in a genetically predisposed host. A gene location in the pericentromeric region of chromosome 16, IBD1, that contributes to susceptibility to Crohn's disease has been established through multiple linkage studies(1-6), but the specific gene(s) has not been identified. NOD2, a gene that encodes a protein with homology to plant disease resistance gene products is located in the peak region of linkage on chromosome 16 (ref. 7). Here we show, by using the transmission disequilibium test and case-control analysis, that a frameshift mutation caused by a cytosine insertion, 3020insC, which is expected to encode a truncated NOD2 protein, is associated with Crohn's disease. Wild-type NOD2 activates nuclear factor NF-kappaB, making it responsive to bacterial lipopolysaccharides; however, this induction was deficient in mutant NOD2. These results implicate NOD2 in susceptibility to Crohn's disease, and suggest a link between an innate immune response to bacterial components and development of disease.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62856/1/411603a0.pd
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