1,065 research outputs found
Jet p_T Resummation in Higgs Production at NNLL'+NNLO
We present predictions for Higgs production via gluon fusion with a p_T veto
on jets and with the resummation of jet-veto logarithms at NNLL'+$NNLO order.
These results incorporate explicit O(alphas^2) calculations of soft and beam
functions, which include the dominant dependence on the jet radius R. In
particular the NNLL' order accounts for the correct boundary conditions for the
N3LL resummation, for which the only unknown ingredients are higher-order
anomalous dimensions. We use scale variations in a factorization theorem in
both rapidity and virtuality space to estimate the perturbative uncertainties,
accounting for both higher fixed-order corrections as well as higher-order
towers of jet-p_T logarithms. This formalism also predicts the correlations in
the theory uncertainty between the exclusive 0-jet and inclusive 1-jet bins. At
the values of R used experimentally, there are important corrections due to jet
algorithm clustering that include logarithms of R. Although we do not sum
logarithms of R, we do include an explicit contribution in our uncertainty
estimate to account for higher-order jet clustering logarithms. Precision
predictions for this H+0-jet cross section and its theoretical uncertainty are
an integral part of Higgs analyses that employ jet binning.Comment: 24 pages, 11 figure
Preliminary Test Results for Full Scale Drilled Shaft Under Cyclic Lateral Loading
Preliminary results are presented of a field testing program for a full-scale, large diameter cast-in-drilled-hole (CIDH) shaft/column under cyclic lateral loading. The shaft was extensively instrumented to enable high precision, redundant section curvature measurements, measurements of pressure at the soil-shaft interface around the shaft perimeter, and in situ measurements of concrete quality. The principal objective of the testing was to characterize the soil-shaft interaction across a wide displacement range to gain insight into the adequacy of existing design guidelines (which are based principally on the testing of small diameter piles) for the large diameter shafts commonly used to support highway bridges in California. Also of interest is the failure mechanism of the shaft-column, since most previous tests of large-diameter shaft-columns do not test the column to large levels of ductility. This testing was only recently completed, and reduction and interpretation of the data is ongoing as of this writing. This paper presents preliminary results of the overall specimen performance across the full range of tested displacements. Details of the soil-shaft interaction remain under study, and are not presented here
Computational Efficiency of Frequency-- and Time--Domain Calculations of Extreme Mass--Ratio Binaries: Equatorial Orbits
Gravitational waveforms and fluxes from extreme mass--ratio inspirals can be
computed using time--domain methods with accuracy that is fast approaching that
of frequency--domain methods. We study in detail the computational efficiency
of these methods for equatorial orbits of fast spinning Kerr black holes, and
find the number of modes needed in either method --as functions of the orbital
parameters-- in order to achieve a desired accuracy level. We then estimate the
total computation time and argue that for high eccentricity orbits the
time--domain approach is more efficient computationally. We suggest that in
practice low-- modes are computed using the frequency--domain approach, and
high-- modes are computed using the time--domain approach, where is the
azimuthal mode number.Comment: 19 figures, 6 table
Inelastic yielding and forebulge shape across a modern foreland basin: North West Shelf of Australia, Timor Sea
The Timor Trough is a modern `underfilled\u27 foreland and basin created by partial subduction of the outer north west continental shelf of Australia beneath Timor Island in the Outer Banda Arc of eastern Indonesia during the Cenozoic. A change of the effective elastic thickness (EET) of the continental foreland lithosphere from approximately 80±20 km to approximately 25 km over a distance of approximately 300 km explains (1) the high curvature (approximately 10-7 m-1) on the outer Trough wall, (2) the low shelf forebulge (approximately 200 m) as measured along a reference base Pliocene unconformity, and (3) observed gravity. An inelastically yielding quartzite-quartz-diorite-dunite continental rheology can explain the EET gradient. New, shallow crustal (\u3c8 \u3ekm), seismic reflection images indicate that Jurassic basement normal faults are reactivated during bending of the foreland
Hypertension in mice lacking 11beta-hydroxysteroid dehydrogenase type 2
Deficiency of 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2) in humans leads to the syndrome of apparent mineralocorticoid excess (SAME), in which cortisol illicitly occupies mineralocorticoid receptors, causing sodium retention, hypokalemia, and hypertension. However, the disorder is usually incompletely corrected by suppression of cortisol, suggesting additional and irreversible changes, perhaps in the kidney. To examine this further, we produced mice with targeted disruption of the 11β-HSD2 gene. Homozygous mutant mice (11β-HSD2(–/–)) appear normal at birth, but ∼50% show motor weakness and die within 48 hours. Both male and female survivors are fertile but exhibit hypokalemia, hypotonic polyuria, and apparent mineralocorticoid activity of corticosterone. Young adult 11β-HSD2(–/–) mice are markedly hypertensive, with a mean arterial blood pressure of 146 ± 2 mmHg, compared with 121 ± 2 mmHg in wild-type controls and 114 ± 4 mmHg in heterozygotes. The epithelium of the distal tubule of the nephron shows striking hypertrophy and hyperplasia. These histological changes do not readily reverse with mineralocorticoid receptor antagonism in adulthood. Thus, 11β-HSD2(–/–) mice demonstrate the major features of SAME, providing a unique rodent model to study the molecular mechanisms of kidney resetting leading to hypertension. J. Clin. Invest. 103:683–689 (1999
The foundations framework for developing and reporting new models of care for multimorbidity
PURPOSE Multimorbidity challenges health systems globally. New models of care are urgently needed to better manage patients with multimorbidity; however, there is no agreed framework for designing and reporting models of care for multimorbidity and their evaluation. METHODS Based on findings from a literature search to identify models of care for multimorbidity, we developed a framework to describe these models. We illustrate the application of the framework by identifying the focus and gaps in current models of care, and by describing the evolution of models over time. RESULTS Our framework describes each model in terms of its theoretical basis and target population (the foundations of the model) and of the elements of care implemented to deliver the model. We categorized elements of care into 3 types: (1) clinical focus, (2) organization of care, (3) support for model delivery. Application of the framework identified a limited use of theory in model design and a strong focus on some patient groups (elderly, high users) more than others (younger patients, deprived populations). We found changes in elements with time, with a decrease in models implementing home care and an increase in models offering extended appointments. CONCLUSIONS By encouraging greater clarity about the underpinning theory and target population, and by categorizing the wide range of potentially important elements of an intervention to improve care for patients with multimorbidity, the framework may be useful in designing and reporting models of care and help advance the currently limited evidence base
Broadband simulations for M_w 7.8 southern San Andreas earthquakes: Ground motion sensitivity to rupture speed
Using the high-performance computing resources of the Southern California Earthquake Center, we simulate broadband (0–10 Hz) ground motions for three M_w 7.8 rupture scenarios of the southern San Andreas fault. The scenarios incorporate a kinematic rupture description with the average rupture speed along the large slip portions of the fault set at 0.96, 0.89, and 0.84 times the local shear wave velocity. Consistent with previous simulations, a southern hypocenter efficiently channels energy into the Los Angeles region along the string of basins south of the San Gabriel Mountains. However, we find the basin ground motion levels are quite sensitive to the prescribed rupture speed, with peak ground velocities at some sites varying by over a factor of two for variations in average rupture speed of about 15%. These results have important implications for estimating seismic hazards in Southern California and emphasize the need for improved understanding of earthquake rupture processes
Risk score predicts high-grade prostate cancer in DNA-methylation positive, histopathologically negative biopsies.
BACKGROUND: Prostate cancer (PCa) diagnosis is challenging because efforts for effective, timely treatment of men with significant cancer typically result in over-diagnosis and repeat biopsies. The presence or absence of epigenetic aberrations, more specifically DNA-methylation of GSTP1, RASSF1, and APC in histopathologically negative prostate core biopsies has resulted in an increased negative predictive value (NPV) of ∼90% and thus could lead to a reduction of unnecessary repeat biopsies. Here, it is investigated whether, in methylation-positive men, DNA-methylation intensities could help to identify those men harboring high-grade (Gleason score ≥7) PCa, resulting in an improved positive predictive value. METHODS: Two cohorts, consisting of men with histopathologically negative index biopsies, followed by a positive or negative repeat biopsy, were combined. EpiScore, a methylation intensity algorithm was developed in methylation-positive men, using area under the curve of the receiver operating characteristic as metric for performance. Next, a risk score was developed combining EpiScore with traditional clinical risk factors to further improve the identification of high-grade (Gleason Score ≥7) cancer. RESULTS: Compared to other risk factors, detection of DNA-methylation in histopathologically negative biopsies was the most significant and important predictor of high-grade cancer, resulting in a NPV of 96%. In methylation-positive men, EpiScore was significantly higher for those with high-grade cancer detected upon repeat biopsy, compared to those with either no or low-grade cancer. The risk score resulted in further improvement of patient risk stratification and was a significantly better predictor compared to currently used metrics as PSA and the prostate cancer prevention trial (PCPT) risk calculator (RC). A decision curve analysis indicated strong clinical utility for the risk score as decision-making tool for repeat biopsy. CONCLUSIONS: Low DNA-methylation levels in PCa-negative biopsies led to a NPV of 96% for high-grade cancer. The risk score, comprising DNA-methylation intensity and traditional clinical risk factors, improved the identification of men with high-grade cancer, with a maximum avoidance of unnecessary repeat biopsies. This risk score resulted in better patient risk stratification and significantly outperformed current risk prediction models such as PCPTRC and PSA. The risk score could help to identify patients with histopathologically negative biopsies harboring high-grade PCa. Prostate 76:1078-1087, 2016. © 2016 The Authors. The Prostate Published by Wiley Periodicals, Inc.MDxHealthThis is the author accepted manuscript. It is currently under an indefinite embargo pending publication by Wiley
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