681 research outputs found
Preliminary Investigations of Early Proterozoic western River and Burnside River Formations : Evidence For Foredeep Origin of Kilohigok Basin, District of Mackenzie
In the Kilohigok Basin, the Western River and Burnside River formations comprise three successively overlying tectono-stratigraphic sedimentary units of regional extent: a basal shallow water siliciclastic/carbonate platform, overlain by deepwater flysch, in turn overlain by shallow
marine and fluvial molasse. This stratigraphy represents an initial stable shelf (passive margin?) whose outer, southerly edge rapidly subsided contemporaneous with arching and subaerial exposure of its interior. Shelf drowning represents the onset of foredeep subsidence subparallel to the trend of Thelon Tectonic Zone. Arching and subsidence were perpendicular to the tectonic transport direction of intrabasinal nappes. indicating that convergence and uplift a long Thelon Tectonic Zone were
probably responsible for foredeep subsidence within Ki lohigok Basin. Following drowning, the platform was buried by deepwater deposits ( flysch); with progressive uplift and basin filling, the foredeep entered the molasse phase and fluvial sediments prograded towards the foreland. The
foredeep model places constraints on the origin of Thelon Tectonic Zone and provides a more comprehensive understanding of the tectonic evolution of the Slave Province and its relation to the Wopmay Orogen
Circumventing antivector immunity: potential use of nonhuman adenoviral vectors
Adenoviruses are efficient gene delivery vectors based on their ability to transduce a wide variety of cell types and drive high-level transient transgene expression. While there have been advances in modifying human adenoviral (HAdV) vectors to increase their safety profile, there are still pitfalls that need to be further addressed. Preexisting humoral and cellular immunity against common HAdV serotypes limits the efficacy of gene transfer and duration of transgene expression. As an alternative, nonhuman AdV (NHAdV) vectors can circumvent neutralizing antibodies against HAdVs in immunized mice and monkeys and in human sera, suggesting that NHAdV vectors could circumvent preexisting humoral immunity against HAdVs in a clinical setting. Consequently, there has been an increased interest in developing NHAdV vectors for gene delivery in humans. In this review, we outline the recent advances and limitations of HAdV vectors for gene therapy and describe examples of NHAdV vectors focusing on their immunogenicity, tropism, and potential as effective gene therapy vehicles
Development and preliminary validation of a tool measuring concordance and belief about performing pressure-relieving activities for pressure ulcer prevention in spinal cord injury
Objective: To develop and examine the reliability, and validity of a questionnaire measuring concordance for performing pressure-relief for pressure ulcer (PrU) prevention in people with Spinal Cord Injury (SCI).
Methods: Phase I included item development, content and face validity testing. In phase II, the questionnaire was evaluated for preliminary acceptability, reliability and validity among 48 wheelchair users with SCI.
Results: Thirty-seven items were initially explored. Item and factor analysis resulted in a final 26-item questionnaire with four factors reflecting concordance, perceived benefits, perceived negative consequences, and personal practical barriers to performing pressure-relief activities. The internal consistency reliability for four domains were very good (Cronbach's α = .75-.89). Pearson correlation coefficient on a test-retest of the same subjects yielded significant correlations in concordance (r = .91, p = .005), perceived benefit (r = .71, p < .04), perceived negative consequences (r = .98, p < .0001), personal barriers (r = .93, p= .002). Participants with higher levels of concordance reported a greater amount of pressure-relieving performed. Individuals viewing PrU as a threatening illness were associated with higher scores of concordance and tended to report a greater amount of pressure-relieving performance which provides evidence of criterion related validity.
Conclusion: The new questionnaire demonstrated good preliminary reliability and validity in people with SCI. Further evaluation is necessary to confirm these findings using larger samples with follow-up data for predictive validity. Such a questionnaire could be used by clinicians to identify high risk of patients and to design individualised education programme for PrU prevention
Community Support and Transition of Research to Operations for the Hurricane Weather Research and Forecasting Model
The Hurricane Weather Research and Forecasting Model (HWRF) is an operational model used to provide numerical guidance in support of tropical cyclone forecasting at the National Hurricane Center. HWRF is a complex multicomponent system, consisting of the Weather Research and Forecasting (WRF) atmospheric model coupled to the Princeton Ocean Model for Tropical Cyclones (POM-TC), a sophisticated initialization package including a data assimilation system and a set of postprocessing and vortex tracking tools. HWRF’s development is centralized at the Environmental Modeling Center of NOAA’s National Weather Service, but it incorporates contributions from a variety of scientists spread out over several governmental laboratories and academic institutions. This distributed development scenario poses significant challenges: a large number of scientists need to learn how to use the model, operational and research codes need to stay synchronized to avoid divergence, and promising new capabilities need to be tested for operational consideration. This article describes how the Developmental Testbed Center has engaged in the HWRF developmental cycle in the last three years and the services it provides to the community in using and developing HWRF
Time-odd components in the mean field of rotating superdeformed nuclei
Rotation-induced time-odd components in the nuclear mean field are analyzed
using the Hartree-Fock cranking approach with effective interactions SIII,
SkM*, and SkP. Identical dynamical moments are obtained for
pairs of superdeformed bands Tb(2)--Dy(1) and
Gd(2)--Tb(1). The corresponding relative alignments strongly
depend on which time-odd mean-field terms are taken into account in the
Hartree-Fock equations.Comment: 23 pages, ReVTeX, 6 uuencoded postscript figures include
Investigating the TeV Morphology of MGRO J1908+06 with VERITAS
We report on deep observations of the extended TeV gamma-ray source MGRO
J1908+06 made with the VERITAS very high energy (VHE) gamma-ray observatory.
Previously, the TeV emission has been attributed to the pulsar wind nebula
(PWN) of the Fermi-LAT pulsar PSR J1907+0602. We detect MGRO J1908+06 at a
significance level of 14 standard deviations (14 sigma) and measure a photon
index of 2.20 +/- 0.10_stat +/- 0.20_sys. The TeV emission is extended,
covering the region near PSR J1907+0602 and also extending towards SNR
G40.5--0.5. When fitted with a 2-dimensional Gaussian, the intrinsic extension
has a standard deviation of sigma_src = 0.44 +/- 0.02 degrees. In contrast to
other TeV PWNe of similar age in which the TeV spectrum softens with distance
from the pulsar, the TeV spectrum measured near the pulsar location is
consistent with that measured at a position near the rim of G40.5--0.5, 0.33
degrees away.Comment: To appear in ApJ, 8 page
Motion Capture of Hands in Action Using Discriminative Salient Points
Abstract. Capturing the motion of two hands interacting with an object is a very challenging task due to the large number of degrees of freedom, self-occlusions, and similarity between the fingers, even in the case of multiple cameras observing the scene. In this paper we propose to use discriminatively learned salient points on the fingers and to estimate the finger-salient point associations simultaneously with the estimation of the hand pose. We introduce a differentiable objective function that also takes edges, optical flow and collisions into account. Our qualitative and quantitative evaluations show that the proposed approach achieves very accurate results for several challenging sequences containing hands and objects in action.
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