1,575 research outputs found
Potential model calculations and predictions for heavy quarkonium
We investigate the spectroscopy and decays of the charmonium and upsilon
systems in a potential model consisting of a relativistic kinetic energy term,
a linear confining term including its scalar and vector relativistic
corrections and the complete perturbative one-loop quantum chromodynamic short
distance potential. The masses and wave functions of the various states are
obtained using a variational technique, which allows us to compare the results
for both perturbative and nonperturbative treatments of the potential. As well
as comparing the mass spectra, radiative widths and leptonic widths with the
available data, we include a discussion of the errors on the parameters
contained in the potential, the effect of mixing on the leptonic widths, the
Lorentz nature of the confining potential and the possible
interpretation of recently discovered charmonium-like states.Comment: Physical Review published versio
Setting Priorities for Space Research: Opportunities and Imperatives
This report represents the first phase of a study by a task group convened by the Space Studies Board to ascertain whether it should attempt to develop a methodology for recommending priorities among the various initiatives in space research (that is, scientific activities concerned with phenomena in space or utilizing observations from space). The report argues that such priority statements by the space research community are both necessary and desirable and would contribute to the formulation and implementation of public policy. The report advocates the establishment of priorities to enhance effective management of the nation's scientific research program in space. It argues that scientific objectives and purposes should determine how and under what circumstances scientific research should be done. The report does not take a position on the controversy between advocates of manned space exploration and those who favor the exclusive use of unmanned space vehicles. Nor does the report address questions about the value or appropriateness of Space Station Freedom or proposals to establish a permanent manned Moon base or to undertake a manned mission to Mars. These issues lie beyond the charge to the task group
Discovering the New Standard Model: Fundamental Symmetries and Neutrinos
This White Paper describes recent progress and future opportunities in the
area of fundamental symmetries and neutrinos.Comment: Report of the Fundamental Symmetries and Neutrinos Workshop, August
10-11, 2012, Chicago, I
Coexistence of 'alpha+ 208Pb' cluster structures and single-particle excitations in 212Po
Excited states in 212Po have been populated by alpha transfer using the
208Pb(18O,14C) reaction at 85MeV beam energy and studied with the EUROBALL IV
gamma multidetector array. The level scheme has been extended up to ~ 3.2 MeV
excitation energy from the triple gamma coincidence data. Spin and parity
values of most of the observed states have been assigned from the gamma angular
distributions and gamma -gamma angular correlations. Several gamma lines with
E(gamma) < 1 MeV have been found to be shifted by the Doppler effect, allowing
for the measurements of the associated lifetimes by the DSAM method. The
values, found in the range [0.1-0.6] ps, lead to very enhanced E1 transitions.
All the emitting states, which have non-natural parity values, are discussed in
terms of alpha-208Pb structure. They are in the same excitation-energy range as
the states issued from shell-model configurations.Comment: 21 pages, 19 figures, corrected typos, revised arguments in Sect.
III
Protein dynamics with off-lattice Monte Carlo moves
A Monte Carlo method for dynamics simulation of all-atom protein models is
introduced, to reach long times not accessible to conventional molecular
dynamics. The considered degrees of freedom are the dihedrals at
C-atoms. Two Monte Carlo moves are used: single rotations about
torsion axes, and cooperative rotations in windows of amide planes, changing
the conformation globally and locally, respectively. For local moves Jacobians
are used to obtain an unbiased distribution of dihedrals. A molecular dynamics
energy function adapted to the protein model is employed. A polypeptide is
folded into native-like structures by local but not by global moves.Comment: 10 pages, 4 Postscript figures, uses epsf.sty and a4.sty; scheduled
tentatively for Phys.Rev.E issue of 1 March 199
Designing spin-1 lattice models using polar molecules
We describe how to design a large class of always on spin-1 interactions
between polar molecules trapped in an optical lattice. The spin degrees of
freedom correspond to the hyperfine levels of a ro-vibrational ground state
molecule. Interactions are induced using a microwave field to mix ground states
in one hyperfine manifold with the spin entangled dipole-dipole coupled excited
states. Using multiple fields anistropic models in one, two, or three
dimensions, can be built with tunable spatial range. An illustrative example in
one dimension is the generalized Haldane model, which at a specific parameter
has a gapped valence bond solid ground state. The interaction strengths are
large compared to decoherence rates and should allow for probing the rich phase
structure of strongly correlated systems, including dimerized and gapped
phases.Comment: 24 pages, 5 figure
The effectiveness of manual stretching in the treatment of plantar heel pain: a systematic review
Background: Plantar heel pain is a commonly occurring foot complaint. Stretching is frequently utilised as a treatment, yet a systematic review focusing only on its effectiveness has not been published. This review aimed to assess the effectiveness of stretching on pain and function in people with plantar heel pain. Methods: Medline, EMBASE, CINAHL, AMED, and The Cochrane Library were searched from inception to July 2010. Studies fulfilling the inclusion criteria were independently assessed, and their quality evaluated using the modified PEDro scale. Results: Six studies including 365 symptomatic participants were included. Two compared stretching with a control, one study compared stretching to an alternative intervention, one study compared stretching to both alternative and control interventions, and two compared different stretching techniques and durations. Quality rating on the modified Pedro scale varied from two to eight out of a maximum of ten points. The methodologies and interventions varied significantly between studies, making meta-analysis inappropriate. Most participants improved over the course of the studies, but when stretching was compared to alternative or control interventions, the changes only reached statistical significance in one study that used a combination of calf muscle stretches and plantar fascia stretches in their stretching programme. Another study comparing different stretching techniques, showed a statistically significant reduction in some aspects of pain in favour of plantar fascia stretching over calf stretches in the short term. Conclusions: There were too few studies to assess whether stretching is effective compared to control or other interventions, for either pain or function. However, there is some evidence that plantar fascia stretching may be more effective than Achilles tendon stretching alone in the short-term. Appropriately powered randomised controlled trials, utilizing validated outcome measures, blinded assessors and long-term follow up are needed to assess the efficacy of stretching
Evaluation of early and late presentation of patients with ocular mucous membrane pemphigoid to two major tertiary referral hospitals in the United Kingdom
PURPOSE: Ocular mucous membrane pemphigoid (OcMMP) is a sight-threatening autoimmune disease in which referral to specialists units for further management is a common practise. This study aims to describe referral patterns, disease phenotype and management strategies in patients who present with either early or established disease to two large tertiary care hospitals in the United Kingdom.\ud
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PATIENTS AND METHODS: In all, 54 consecutive patients with a documented history of OcMMP were followed for 24 months. Two groups were defined: (i) early-onset disease (EOD:<3 years, n=26, 51 eyes) and (ii) established disease (EstD:>5 years, n=24, 48 eyes). Data were captured at first clinic visit, and at 12 and 24 months follow-up. Information regarding duration, activity and stage of disease, visual acuity (VA), therapeutic strategies and clinical outcome were analysed.\ud
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RESULTS: Patients with EOD were younger and had more severe conjunctival inflammation (76% of inflamed eyes) than the EstD group, who had poorer VA (26.7%=VA<3/60, P<0.01) and more advanced disease. Although 40% of patients were on existing immunosuppression, 48% required initiation or switch to more potent immunotherapy. In all, 28% (14) were referred back to the originating hospitals for continued care. Although inflammation had resolved in 78% (60/77) at 12 months, persistence of inflammation and progression did not differ between the two phenotypes. Importantly, 42% demonstrated disease progression in the absence of clinically detectable inflammation.\ud
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CONCLUSIONS: These data highlight that irrespective of OcMMP phenotype, initiation or escalation of potent immunosuppression is required at tertiary hospitals. Moreover, the conjunctival scarring progresses even when the eye remains clinically quiescent. Early referral to tertiary centres is recommended to optimise immunosuppression and limit long-term ocular damage.\ud
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Contamination Control and Assay Results for the Majorana Demonstrator Ultra Clean Components
The MAJORANA DEMONSTRATOR is a neutrinoless double beta decay experiment
utilizing enriched Ge-76 detectors in 2 separate modules inside of a common
solid shield at the Sanford Underground Research Facility. The DEMONSTRATOR has
utilized world leading assay sensitivities to develop clean materials and
processes for producing ultra-pure copper and plastic components. This
experiment is now operating, and initial data provide new insights into the
success of cleaning and processing. Post production copper assays after the
completion of Module 1 showed an increase in U and Th contamination in finished
parts compared to starting bulk material. A revised cleaning method and
additional round of surface contamination studies prior to Module 2
construction have provided evidence that more rigorous process control can
reduce surface contamination. This article describes the assay results and
discuss further studies to take advantage of assay capabilities for the purpose
of maintaining ultra clean fabrication and process design.Comment: Proceedings of Low Radioactivity Techniques (LRT May 2017, Seoul
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