1,313 research outputs found
Predicted modulated differential rates for direct WIMP searches at low energy transfers
The differential event rate for direct detection of dark matter, both the
time averaged and the modulated one due to the motion of the Earth, are
discussed. The calculations focus on relatively light cold dark matter
candidates (WIMP) and low energy transfers. It is shown that for sufficiently
light WIMPs the extraction of relatively large nucleon cross sections is
possible. Furthermore for some WIMP masses the modulation amplitude may change
sign, meaning that, in such a case, the maximum rate may occur six months later
than naively expected. This effect can be exploited to yield information about
the mass of the dark matter candidate, if and when the observation of the
modulation of the event rate is established.Comment: 16 pages, 22 figures; references adde
Electron impact dissociative excitation of water within the adiabatic nuclei approximation
The R-matrix method is used to calculate dissociative excitation cross sections for the four lowest-lying electronically excited states of H2O in the energy range 5-15 eV. For the first time calculations are performed taking into account the nuclear motion by means of an adaptation of the adiabatic nuclei approximation. Cross sections are compared with previous and new fixed-nuclei results and also experiments. Resonance positions and widths are calculated for different geometries of the water molecule
A note on the probability of generating alternating or symmetric groups
We improve on recent estimates for the probability of generating the
alternating and symmetric groups and . In
particular we find the sharp lower bound, if the probability is given by a
quadratic in . This leads to improved bounds on the largest number
such that a direct product of copies
of can be generated by two elements
Ariel - Volume 5 Number 3
Editor
J.D. Kanofsky
Entertainment Editors
Robert Breckenridge
Gary Kaskey
Overseas Editor
Mike Sinason
Staff
Ken Jaffe
Bob Sklaroff
Janet Weish
David Jacoby
Circulation Editor
Jay Amsterdam
Humorist
Jim McCan
GTOBAS: fitting continuum functions with Gaussian-type orbitals
GTOBAS is a program for fitting Gaussian-type orbitals (GTOs) to Bessel and Coulomb functions over a finite range. The exponents of the GTOs are optimized using the method of Nestmann and Peyerimhoff [J. Phys. B 23 (1990) L773]. The appended module NUMCBAS provides the numerical Bessel and Coulomb functions required as input for the program. The use of GTO continuum basis sets is particularly important in electron–molecule scattering calculations when polyatomic targets are involved. Sample results for such calculations are also discussed
Neuropsychological profile of patients with normal pressure hydrocephalus and Alzheimer's disease
RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are
A systematic review of approaches for continuous quality improvement capacity-building
Context: Continuous quality improvement (CQI) has become prominent in public health settings; yet, little consolidated guidance exists for building CQI capacity of community-based organizations. Objective: To synthesize relevant literature to identify guiding principles and core components critical to building the capacity of organizations to adopt and use CQI. Design: We employed a systematic review approach to assess guiding principles and core components for CQI capacity-building as outlined in the literature. Eligibility Criteria: Studies meeting the following criteria were eligible for review: (1) empirical, peer-reviewed journal article, evaluation study, review, or systematic review; (2) published in 2010 or later; and (3) capacity-building activities were described in enough detail to be replicable. Studies not including human subjects, published in a language other than English, or for which full text was not available were excluded. Study Selection: The initial return of records included 6557 articles, of which 1455 were duplicates. The research team single-screened titles and abstracts of 5102 studies, resulting in the exclusion of 4842 studies. Two hundred sixty-two studies were double-screened during full-text review, yielding a final sample of 61 studies from which data were extracted. Main Outcome Measures: Outcome measures of interest were operationalized descriptions of guiding principles and core components of the CQI capacity-building approach. Results: Results yielded articles from medical education, health care, and public health settings. Findings included guiding principles and core components of CQI capacity-building identified in current practice, as well as infrastructural and contextual elements needed to build CQI capacity. Conclusions: This consolidation of guiding principles and core components for CQI capacity-building is valuable for public health and related workforces. Despite the uneven distribution of articles from health care, medical education, and public health settings, our findings can be used to guide public health organizations in building CQI capacity in a well-informed, systematic manner
Knowledge, Food and Place: a way of producing a way of knowing
The article examines the dynamics of knowledge in the valorisation of local food, drawing on the results from the CORASON project (A cognitive approach to rural sustainable development: the dynamics of expert and lay knowledge), funded by the EU under its Framework Programme 6. It is based on the analysis of several in-depth case studies on food relocalisation carried out in 10 European countries
Preconditioning the solution of the time- dependent neutron diffusion equation by recycling Krylov subspaces
[EN] Spectral preconditioners are based on the fact that the convergence rate of Krylov subspace
methods is improved if the eigenvalues of smallest magnitude of the system matrix are
`removed'. In this paper, two preconditioning strategies are studied to solve a set of linear
systems associated with the numerical integration of the time dependent neutron di usion
equation. Both strategies can be implemented using the matrix-vector product as the main
operation and succeed at reducing the total number of iterations needed to solve the set of
systems.This work has been partially supported by the Spanish Ministerio de Educacion y Ciencia under projects MTM2010-18674 and ENE2011-22823.González Pintor, S.; Ginestar Peiro, D.; Verdú Martín, GJ. (2014). Preconditioning the solution of the time- dependent neutron diffusion equation by recycling Krylov subspaces. International Journal of Computer Mathematics. 91(1):42-52. https://doi.org/10.1080/00207160.2013.771181S425291
Association of FCGR3A and FCGR3B haplotypes with rheumatoid arthritis and primary Sjögren's syndrome [POSTER PRESENTATION]
Background
Rheumatoid arthritis (RA) is an autoimmune disease that is thought to arise from a complex interaction between multiple genetic factors and environmental triggers. We have previously demonstrated an association between a Fc gamma receptor (FcγR) haplotype and RA in a cross-sectional cohort of RA patients. We have sought to confirm this association in an inception cohort of RA patients and matched controls. We also extended our study to investigate a second autoanti-body associated rheumatic disease, primary Sjögren's syndrome (PSS).
Methods
The FCGR3A-158F/V and FCGR3B-NA1/NA2 functional polymorphisms were examined for association in an inception cohort of RA patients (n = 448), and a well-characterised PSS cohort (n = 83) from the United Kingdom. Pairwise disequilibrium coefficients (D') were calculated in 267 Blood Service healthy controls. The EHPlus program was used to estimate haplotype frequencies for patients and controls and to determine whether significant linkage disequilibrium was present. A likelihood ratio test is performed to test for differences between the haplotype frequencies in cases and controls. A permutation procedure implemented in this program enabled 1000 permutations to be performed on all haplotype associations to assess significance.
Results
There was significant linkage disequilibrium between FCGR3A and FCGR3B (D' = -0.445, P = 0.001). There was no significant difference in the FCGR3A or FCGR3B allele or genotype frequencies in the RA or PSS patients compared with controls. However, there was a significant difference in the FCGR3A-FCGR3B haplotype distributions with increased homozygosity for the FCGR3A-FCGR3B 158V-NA2 haplotype in both our inception RA cohort (odds ratio = 2.15, 95% confidence interval = 1.1–4.2 P = 0.027) and PSS (odds ratio = 2.83, 95% confidence interval = 1.0–8.2, P = 0.047) compared with controls. The reference group for these analyses comprised individuals who did not possess a copy of the FCGR3A-FCGR3B 158V-NA2 haplotype.
Conclusions
We have confirmed our original findings of association between the FCGR3A-FCGR3B 158V-NA2 haplotype and RA in a new inception cohort of RA patients. This suggests that there may be an RA-susceptibility gene at this locus. The significant increased frequency of an identical haplotype in PSS suggests the FcγR genetic locus may contribute to the pathogenesis of diverse autoantibody-mediated rheumatic diseases
- …