1,155 research outputs found
Sociodemographic Trends in National Ambulatory Care Visits for Hepatitis C Virus Infection
Poor and non-white patients are disproportionately infected with the hepatitis C virus (HCV). The objective of this research is to determine sociodemographic patterns of HCV-related ambulatory care visits over time. Data from the National Ambulatory Medical Care Survey (NAMCS) and the National Hospital Ambulatory Medical Care Survey-Outpatient (NHAMCS-OPD) for the years 1997â2005 were analyzed in 3-year intervals. Demographic and other variables were compared for each period, and multivariable logistic regression was performed to examine whether the likelihood of a visit being HCV-related (versus non-HCV) was independently associated with (1) race and/or (2) Medicaid status over time. The total number of HCV-related ambulatory visits more than doubled from 3,583,585 during the years 1997â1999 to 8,027,166 during 2003â2005. During this time, the proportion of non-whites and Medicaid recipients presenting for HCV-related visits approximately doubled (non-whites: 16% vs. 33%, PÂ =Â 0.04; Medicaid recipients: 10% vs. 25%, PÂ =Â 0.07). In 2003â2005, HCV-related visits were more than twice as likely to occur among non-white patients vs. white patients (ORÂ =Â 2.49; 95% CI: 1.60â3.86) and patients on Medicaid vs. non-Medicaid (3.49; 1.79â6.80). Our results show that HCV-associated ambulatory care visits are increasing, with a greater proportion of visits occurring among non-white patients and Medicaid recipients
An ecological analysis of colorectal cancer incidence and mortality: Differences by sexual orientation
<p>Abstract</p> <p>Background</p> <p>Some have suggested gays and lesbians may carry a greater burden of colorectal cancer. To date, individual sexual orientation data are not available in cancer surveillance registries. This prevents an assessment of differences in colorectal cancer incidence and mortality by sexual orientation, using individual-level data.</p> <p>Methods</p> <p>We use an ecological approach to examine differences in colorectal cancer incidence and mortality by county-level sexual orientation data. From the Surveillance, Epidemiology and End Results (SEER) Program we obtain population-based surveillance data on colorectal cancer incidence and mortality from 1996 to 2004. We use Census 2000 data on same-sex partnered households, a proxy of sexual orientation, to derive county-level sexual orientation data. Using multiple regression models, we examined the county-level association of sexual minority density with colorectal cancer incidence and mortality.</p> <p>Results</p> <p>After controlling for race and SES, we identify a significant positive association between greater density of sexual minority men and women and colorectal cancer incidence. With respect to colorectal cancer mortality, we identify a positive association with density of sexual minority men, but not women.</p> <p>Conclusions</p> <p>In the absence of surveillance data on sexual minority individuals, ecological analyses provide estimates of associations at the aggregate level, thereby providing crucial information for follow-up studies.</p
The relativistic Sagnac Effect: two derivations
The phase shift due to the Sagnac Effect, for relativistic matter and
electromagnetic beams, counter-propagating in a rotating interferometer, is
deduced using two different approaches. From one hand, we show that the
relativistic law of velocity addition leads to the well known Sagnac time
difference, which is the same independently of the physical nature of the
interfering beams, evidencing in this way the universality of the effect.
Another derivation is based on a formal analogy with the phase shift induced by
the magnetic potential for charged particles travelling in a region where a
constant vector potential is present: this is the so called Aharonov-Bohm
effect. Both derivations are carried out in a fully relativistic context, using
a suitable 1+3 splitting that allows us to recognize and define the space where
electromagnetic and matter waves propagate: this is an extended 3-space, which
we call "relative space". It is recognized as the only space having an actual
physical meaning from an operational point of view, and it is identified as the
'physical space of the rotating platform': the geometry of this space turns out
to be non Euclidean, according to Einstein's early intuition.Comment: 49 pages, LaTeX, 3 EPS figures. Revised (final) version, minor
corrections; to appear in "Relativity in Rotating Frames", ed. G. Rizzi and
M.L. Ruggiero, Kluwer Academic Publishers, Dordrecht, (2003). See also
http://digilander.libero.it/solciclo
Irreversible Pulmonary Hypertension Associated with the use of Interferon Alpha for Chronic Hepatitis C
The interferons are a complex group of virally induced proteins produced by activated macrophages and lymphocytes, which have become the mainstay of therapy for hepatitis C infection. Sustained viral response (SVR) rates in noncirrhotic patients vary from 40â80% with interferon-based therapy. This, along with transplantation, has drastically changed the course of hepatitis C virus (HCV) infection over the last two decades. Numerous side effects associated with interferon therapy have been reported. These range from transient flu-like symptoms to serious effects such as cardiac arrhythmias, cardiomyopathy, renal and liver failure, polyneuropathy, and myelosuppression. Pulmonary side effects including pneumonitis, pulmonary fibrosis, and reversible pulmonary hypertension have been reported. Herein, we present four cases in which irreversible pulmonary hypertension was diagnosed after prolonged treatment with interferon alpha. In each case, other causes of pulmonary hypertension were systematically eliminated. Pulmonary artery hypertension, which may be irreversible, should be considered in patients being treated with interferon alpha who present with exertional dyspnea and do not have a readily identifiable inflammatory or thromboembolic cause
Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector
The inclusive and dijet production cross-sections have been measured for jets
containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass
energy of sqrt(s) = 7 TeV, using the ATLAS detector at the LHC. The
measurements use data corresponding to an integrated luminosity of 34 pb^-1.
The b-jets are identified using either a lifetime-based method, where secondary
decay vertices of b-hadrons in jets are reconstructed using information from
the tracking detectors, or a muon-based method where the presence of a muon is
used to identify semileptonic decays of b-hadrons inside jets. The inclusive
b-jet cross-section is measured as a function of transverse momentum in the
range 20 < pT < 400 GeV and rapidity in the range |y| < 2.1. The bbbar-dijet
cross-section is measured as a function of the dijet invariant mass in the
range 110 < m_jj < 760 GeV, the azimuthal angle difference between the two jets
and the angular variable chi in two dijet mass regions. The results are
compared with next-to-leading-order QCD predictions. Good agreement is observed
between the measured cross-sections and the predictions obtained using POWHEG +
Pythia. MC@NLO + Herwig shows good agreement with the measured bbbar-dijet
cross-section. However, it does not reproduce the measured inclusive
cross-section well, particularly for central b-jets with large transverse
momenta.Comment: 10 pages plus author list (21 pages total), 8 figures, 1 table, final
version published in European Physical Journal
Observation of associated near-side and away-side long-range correlations in âsNN=5.02ââTeV proton-lead collisions with the ATLAS detector
Two-particle correlations in relative azimuthal angle (ÎÏ) and pseudorapidity (Îη) are measured in âsNN=5.02ââTeV p+Pb collisions using the ATLAS detector at the LHC. The measurements are performed using approximately 1ââÎŒb-1 of data as a function of transverse momentum (pT) and the transverse energy (ÎŁETPb) summed over 3.1<η<4.9 in the direction of the Pb beam. The correlation function, constructed from charged particles, exhibits a long-range (2<|Îη|<5) ânear-sideâ (ÎÏâŒ0) correlation that grows rapidly with increasing ÎŁETPb. A long-range âaway-sideâ (ÎÏâŒÏ) correlation, obtained by subtracting the expected contributions from recoiling dijets and other sources estimated using events with small ÎŁETPb, is found to match the near-side correlation in magnitude, shape (in Îη and ÎÏ) and ÎŁETPb dependence. The resultant ÎÏ correlation is approximately symmetric about Ï/2, and is consistent with a dominant cosâĄ2ÎÏ modulation for all ÎŁETPb ranges and particle pT
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