2,031 research outputs found
Light hadron, Charmonium(-like) and Bottomonium(-like) states
Hadron physics represents the study of strongly interacting matter in all its
manifestations and the understanding of its properties and interactions. The
interest on this field has been revitalized by the discovery of new light
hadrons, charmonium- and bottomonium-like states. I review the most recent
experimental results from different experiments.Comment: Presented at Lepton-Photon 2011, Mumbai, India; 21 pages, 18 figures;
add more references; some correctio
Simultaneous Extraction of the Fermi constant and PMNS matrix elements in the presence of a fourth generation
Several recent studies performed on constraints of a fourth generation of
quarks and leptons suffer from the ad-hoc assumption that 3 x 3 unitarity holds
for the first three generations in the neutrino sector. Only under this
assumption one is able to determine the Fermi constant G_F from the muon
lifetime measurement with the claimed precision of G_F = 1.16637 (1) x 10^-5
GeV^-2. We study how well G_F can be extracted within the framework of four
generations from leptonic and radiative mu and tau decays, as well as from K_l3
decays and leptonic decays of charged pions, and we discuss the role of lepton
universality tests in this context. We emphasize that constraints on a fourth
generation from quark and lepton flavour observables and from electroweak
precision observables can only be obtained in a consistent way if these three
sectors are considered simultaneously. In the combined fit to leptonic and
radiative mu and tau decays, K_l3 decays and leptonic decays of charged pions
we find a p-value of 2.6% for the fourth generation matrix element |U_{e 4}|=0
of the neutrino mixing matrix.Comment: 19 pages, 3 figures with 16 subfigures, references and text added
refering to earlier related work, figures and text in discussion section
added, results and conclusions unchange
The Late Reionization of Filaments
We study the topology of reionization using accurate three-dimensional
radiative transfer calculations post-processed on outputs from cosmological
hydrodynamic simulations. In our simulations, reionization begins in overdense
regions and then "leaks" directly into voids, with filaments reionizing last
owing to their combination of high recombination rate and low emissivity. This
result depends on the uniquely-biased emissivity field predicted by our
prescriptions for star formation and feedback, which have previously been shown
to account for a wide array of measurements of the post-reionization Universe.
It is qualitatively robust to our choice of simulation volume, ionizing escape
fraction, and spatial resolution (in fact it grows stronger at higher spatial
resolution) even though the exact overlap redshift is sensitive to each of
these. However, it weakens slightly as the escape fraction is increased owing
to the reduced density contrast at higher redshift. We also explore whether our
results are sensitive to commonly-employed approximations such as using
optically-thin Eddington tensors or substantially altering the speed of light.
Such approximations do not qualitatively change the topology of reionization.
However, they can systematically shift the overlap redshift by up to , indicating that accurate radiative transfer is essential for
computing reionization. Our model cannot simultaneously reproduce the observed
optical depth to Thomson scattering and ionization rate per hydrogen atom at
, which could owe to numerical effects and/or missing early sources of
ionization.Comment: 16 pages, 9 figures, accepted to MNRA
Barriers to following dietary recommendations in Type 2 diabetes
Aims To evaluate barriers to following dietary recommendations in patients with Type 2 diabetes. Methods We conducted focus groups and surveys in urban and suburban VA and academic medical centres. For the written survey, a self-administered questionnaire was mailed to a random sample of 446 patients with diabetes. For the focus groups, six groups of patients with diabetes (three urban, three suburban) were conducted, with 6–12 participants in each group. The focus groups explored barriers across various types of diabetes self-management; we extracted all comments relevant to barriers that limited patients’ ability to follow a recommended diet. Results The written survey measured the burden of diabetes therapies (on a seven-point rating scale). Moderate diet was seen as a greater burden than oral agents (median 1 vs. 0, P = 0.001), but less of a burden than insulin (median 1 vs. 4, P < 0.001). A strict diet aimed at weight loss was rated as being similarly burdensome to insulin (median 4 vs. 4, P = NS). Despite this, self-reported adherence was much higher for both pills and insulin than it was for a moderate diet. In the focus groups, the most commonly identified barrier was the cost (14/14 reviews), followed by small portion sizes (13/14 reviews), support and family issues (13/14 reviews), and quality of life and lifestyle issues (12/14 reviews). Patients in the urban site, who were predominantly African-American, noted greater difficulties communicating with their provider about diet and social circumstances, and also that the rigid schedule of a diabetes diet was problematic. Conclusions Barriers to adherence to dietary therapies are numerous, but some, such as cost, and in the urban setting, communication with providers, are potentially remediable. Interventions aimed at improving patients’ ability to modify their diet need to specifically address these areas. Furthermore, treatment guidelines need to consider patients’ preferences and barriers when setting goals for treatment. Diabet. Med. (2004)Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73213/1/j.1464-5491.2004.01342.x.pd
Models in the delivery of depression care: A systematic review of randomised and controlled intervention trials
<p>Abstract</p> <p>Background</p> <p>There is still debate as to which features, types or components of primary care interventions are associated with improved depression outcomes. Previous reviews have focused on components of collaborative care models in general practice settings. This paper aims to determine the effective components of depression care in primary care through a systematic examination of both general practice and community based intervention trials.</p> <p>Methods</p> <p>Fifty five randomised and controlled research trials which focused on adults and contained depression outcome measures were identified through PubMed, PsycInfo and the Cochrane Central Register of Controlled Trials databases. Trials were classified according to the components involved in the delivery of treatment, the type of treatment, the primary focus or setting of the study, detailed features of delivery, and the discipline of the professional providing the treatment. The primary outcome measure was significant improvement on the key depression measure.</p> <p>Results</p> <p>Components which were found to significantly predict improvement were the revision of professional roles, the provision of a case manager who provided direct feedback and delivered a psychological therapy, and an intervention that incorporated patient preferences into care. Nurse, psychologist and psychiatrist delivered care were effective, but pharmacist delivery was not. Training directed to general practitioners was significantly less successful than interventions that did not have training as the most important intervention. Community interventions were effective.</p> <p>Conclusion</p> <p>Case management is important in the provision of care in general practice. Certain community models of care (education programs) have potential while others are not successful in their current form (pharmacist monitoring).</p
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