424 research outputs found
OSL surface exposure dating of a lithic quarry in Tibet: Laboratory validation and application
The atmospheric charged kaon/pion ratio using seasonal variation methods
Observed since the 1950's, the seasonal effect on underground muons is a well
studied phenomenon. The interaction height of incident cosmic rays changes as
the temperature of the atmosphere changes, which affects the production height
of mesons (mostly pions and kaons). The decay of these mesons produces muons
that can be detected underground. The production of muons is dominated by pion
decay, and previous work did not include the effect of kaons. In this work, the
methods of Barrett and MACRO are extended to include the effect of kaons. These
efforts give rise to a new method to measure the atmospheric K/ ratio at
energies beyond the reach of current fixed target experiments. These methods
were applied to data from the MINOS far detector. A method is developed for
making these measurements at other underground detectors, including OPERA,
Super-K, IceCube, Baksan and the MINOS near detector.Comment: 15 pages, 4 figures, submitted to Astropart. Phy
On Differential Structure for Projective Limits of Manifolds
We investigate the differential calculus defined by Ashtekar and Lewandowski
on projective limits of manifolds by means of cylindrical smooth functions and
compare it with the C^infty calculus proposed by Froehlicher and Kriegl in more
general context. For products of connected manifolds, a Boman theorem is
proved, showing the equivalence of the two calculi in this particular case.
Several examples of projective limits of manifolds are discussed, arising in
String Theory and in loop quantization of Gauge Theories.Comment: 38 pages, Latex 2e, to be published on J. Geom. Phys minor misprints
corrected, reference adde
Emerging and recurring diseases in cetaceans worldwide and the role of environmental stressors. Scientific Committee Document SC/60/DW5, International Whaling Commission, June 2008, Santiago, Chile
Emerging and recurring infectious diseases known or suspected to have the potential to significantly impact cetacean populations, and possible synergistic effects of environmental factors are reviewed. Cetacean morbilliviruses and papillomaviruses and brucellosis may affect population densities through high mortality rates or interference with reproduction. Evidence is available for the role of environmental factors in the emergence/recurrence and severity of at least six infectious conditions i.e. lobomycosis, toxoplasmosis, tattoo skin disease, generalized bacterial infections, miscellaneous skin diseases and morbillivirus epizootics. Other micro-parasites of potential importance include rhabdo-, herpes- and parainfluenza-viruses as well as Helicobacter spp., Streptococcus spp., Salmonella spp. and Mycobacterium marinum. The population impact and aetiology of newly emerging skin diseases in South America are unknown and represent a cause of concern
Understanding the influence of the head coach on soccer training drills—an 8 season analysis
Soccer players perform a variety of training drills to develop the physical, technical and tactical qualities required for match-play. The role of coaches in prescribing training suggests that players may not always meet physical targets set by conditioning staff. To quantify the physical outputs elicited by different training drill types, 183 professional soccer players were monitored over 8 seasons using Microelectromechanical Systems during normal training, yielding 65,825 drill observations [362 ± 341 observations·player−1]. Linear mixed models assessed the influence of drill type, head coach and playing position on physical output. Drills lasted ~14 min, eliciting total distances and high speed running of ~1000 m and 40 m, respectively. Conditioning drills elicited substantially greater relative high-speed running [18.8 ± 27.2 m.min−1] and Sprint [3.5 ± 9.4 m.min−1] distances than all other drill types. The proportion of training drill types used and external outputs elicited per drill were affected by the head coach. Midfielders recorded the highest total distance [77.3 ± 36.1 m.min] and PlayerLoad™ [8.29 ± 3.54] of any playing position, whilst the lowest outputs were recorded by goalkeepers. This study provides reference data for practitioners when seeking to manipulate training prescription to achieve physical output targets whilst also meeting the team’s technical and tactical objectives
Acute and longer-term cardiovascular conditions in the Deepwater Horizon Oil Spill Coast Guard Cohort
Introduction: In 2010, the U.S. Coast Guard (USCG) led a clean-up response to the Deepwater Horizon (DWH) oil spill. Human studies evaluating acute and longer-term cardiovascular conditions associated with oil spill-related exposures are sparse. Thus, we aimed to investigate prevalent and incident cardiovascular symptoms/conditions in the DHW Oil Spill Coast Guard Cohort. Methods: Self-reported oil spill exposures and cardiovascular symptoms were ascertained from post-deployment surveys (n = 4,885). For all active-duty cohort members (n = 45,193), prospective cardiovascular outcomes were classified via International Classification of Diseases, 9th Edition from military health encounter records up to 5.5 years post-DWH. We used log-binomial regression to calculate adjusted prevalence ratios (aPRs) and 95% confidence intervals (CIs) in the cross-sectional analyses and Cox Proportional Hazards regression to calculate adjusted hazard ratios (aHR) and 95% CIs for incident cardiovascular diagnoses during 2010–2015 and stratifying by earlier (2010–2012) and later (2013–2015) time periods. Results: Prevalence of chest pain was associated with increasing levels of crude oil exposure via inhalation (aPRhigh vs. none = 2.00, 95% CI = 1.16–3.42, p-trend = 0.03) and direct skin contact (aPRhigh vs. none = 2.72, 95% CI = 1.30–5.16, p-trend = 0.03). Similar associations were observed for sudden heartbeat changes and for being in the vicinity of burning oil exposure. In prospective analyses, responders (vs. non-responders) had an elevated risk for mitral valve disorders during 2013–2015 (aHR = 2.12, 95% CI = 1.15–3.90). Responders reporting ever (vs. never) crude oil inhalation exposure were at increased risk for essential hypertension, particularly benign essential hypertension during 2010–2012 (aHR = 2.00, 95% CI = 1.08–3.69). Responders with crude oil inhalation exposure also had an elevated risk for palpitations during 2013–2015 (aHR = 2.54, 95% CI = 1.36–4.74). Cardiovascular symptoms/conditions aPR and aHR estimates were generally stronger among responders reporting exposure to both crude oil and oil dispersants than among those reporting neither. Conclusions: In this large study of the DWH oil spill USCG responders, self-reported spill clean-up exposures were associated with acute and longer-term cardiovascular symptoms/conditions
Search for the Proton Decay Mode proton to neutrino K+ in Soudan 2
We have searched for the proton decay mode proton to neutrino K+ using the
one-kiloton Soudan 2 high resolution calorimeter. Contained events obtained
from a 3.56 kiloton-year fiducial exposure through June 1997 are examined for
occurrence of a visible K+ track which decays at rest into mu+ nu or pi+ pi0.
We found one candidate event consistent with background, yielding a limit,
tau/B > 4.3 10^{31} years at 90% CL with no background subtraction.Comment: 13 pages, Latex, 3 tables and 3 figures, Accepted by Physics Letters
NMR and NQR Fluctuation Effects in Layered Superconductors
We study the effect of thermal fluctuations of the s-wave order parameter of
a quasi two dimensional superconductor on the nuclear spin relaxation rate near
the transition temperature Tc. We consider both the effects of the amplitude
fluctuations and the Berezinskii-Kosterlitz-Thouless (BKT) phase fluctuations
in weakly coupled layered superconductors. In the treatment of the amplitude
fluctuations we employ the Gaussian approximation and evaluate the longitudinal
relaxation rate 1/T1 for a clean s-wave superconductor, with and without pair
breaking effects, using the static pair fluctuation propagator D. The increase
in 1/T1 due to pair breaking in D is overcompensated by the decrease arising
from the single particle Green's functions. The result is a strong effect on
1/T1 for even a small amount of pair breaking. The phase fluctuations are
described in terms of dynamical BKT excitations in the form of pancake
vortex-antivortex (VA) pairs. We calculate the effect of the magnetic field
fluctuations caused by the translational motion of VA excitations on 1/T1 and
on the transverse relaxation rate 1/T2 on both sides of the BKT transitation
temperature T(BKT)<Tc. The results for the NQR relaxation rates depend strongly
on the diffusion constant that governs the motion of free and bound vortices as
well as the annihilation of VA pairs. We discuss the relaxation rates for real
multilayer systems where the diffusion constant can be small and thus increase
the lifetime of a VA pair, leading to an enhancement of the rates. We also
discuss in some detail the experimental feasibility of observing the effects of
amplitude fluctuations in layered s-wave superconductors such as the
dichalcogenides and the effects of phase fluctuations in s- or d-wave
superconductors such as the layered cuprates.Comment: 38 pages, 12 figure
Novel Genetic Variants for Cartilage Thickness and Hip Osteoarthritis
Osteoarthritis is one of the most frequent and disabling diseases of the elderly. Only few genetic variants have been identified for osteoarthritis, which is partly due to large phenotype heterogeneity. To reduce heterogeneity, we here examined cartilage thickness, one of the structural components of joint health. We conducted a genome-wide association study of minimal joint space width (mJSW), a proxy for cartilage thickness, in a discovery set of 13,013 participants from five different cohorts and replication in 8,227 individuals from seven independent cohorts. We identified five genome-wide significant (GWS, P≤5·0×10−8) SNPs annotated to four distinct loci. In addition, we found two additional loci that were significantly replicated, but results of combined meta-analysis fell just below the genome wide significance threshold. The four novel associated genetic loci were located in/near TGFA (rs2862851), PIK3R1 (rs10471753), SLBP/FGFR3 (rs2236995), and TREH/DDX6 (rs49654
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
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