230 research outputs found
Azimuthal Correlation in Lepton-Hadron Scattering via Charged Weak-Current Processes
We consider the azimuthal correlation of the final-state particles in charged
weak-current processes. This correlation provides a test of perturbative
quantum chromodynamics. The azimuthal asymmetry is large in the semi-inclusive
processes in which we identify a final-state hadron, say, a charged pion
compared to that in the inclusive processes in which we do not identify
final-state particles and use only the calorimetric information. In
semi-inclusive processes the azimuthal asymmetry is more conspicuous when the
incident lepton is an antineutrino or a positron than when the incident lepton
is a neutrino or an electron. We analyze all the possible charged weak-current
processes and study the quantitative aspects of each process. We also compare
this result to the ep scattering with a photon exchange.Comment: 25 pages, 2 Postscript figures, uses RevTeX, fixes.st
Inpatient Antipsychotic Drug Use in 1998, 1993, and 1989
OBJECTIVE: Patterns of clinical use of antipsychotic agents have changed greatly in the past decade. The authorsâ goal was to examine these patterns.
METHOD: They evaluated medication use in all McLean Hospital inpatients treated with antipsychotic drugs during 3 months in 1998 (N=349) and compared the results with McLean Hospital inpatients treated with antipsychotics in 1993 (N=299) and Boston area inpatients in 1989 (N=50).
RESULTS: The most commonly prescribed antipsychotics in 1998 were atypical agents; olanzapine was prescribed more often than risperidone or quetiapine, which were prescribed more often than other antipsychotics. Two or more antipsychotics were prescribed at some time during their hospitalization for 150 (43%) of the patients in 1998. The total discharge dose in chlorpromazine equivalents for the 349 patients for whom antipsychotics were prescribed at discharge was 371 mg/day, 29% higher than the total discharge dose for patients in 1993 and 46% greater than the dose in 1989. The dose of antipsychotics was greater for patients with psychotic illnesses than for those with affective illnesses. Higher doses were associated with greater clinical improvement, polypharmacotherapy, and younger patient age.
CONCLUSIONS: Emerging trends toward higher total antipsychotic doses and polypharmacotherapy require critical assessments of cost-benefit relationships
Moments of the Virtual Photon Structure Function
The photon structure function is a useful testing ground for QCD. It is
perturbatively computable apart from a contribution from what is usually called
the hadronic component of the photon. There have been many proposals for this
nonperturbative part of the real photon structure function. By studying moments
of the virtual photon structure function, we explore the extent to which these
proposed nonperturbative contributions can be identified experimentally.Comment: LaTeX, 16 pages + 14 compressed and uuencoded postscript figures,
UMN-TH-1111/9
Latent tuberculosis infection screening and treatment in congregate settings (TB FREE COREA): protocol for a prospective observational study in Korea
IntroductionSouth Korea regards tuberculosis (TB) incidence in congregate settings as a serious problem. To this end, systematic latent TB infection (LTBI) diagnosis and treatment were provided to approximately 1.2âmillion individuals in high-risk congregate settings.Methods and analysisWe designed a prospective cohort study of individuals tested for LTBI, based on the data collected on all persons screened for LTBI as part of the 2017 congregate settings programme in South Korea. Four types of databases are kept: LTBI screening database (personal information and LTBI test results), national health information (NHI) database (socio-demographic data and comorbidities), public healthcare information system (PHIS) database, and the Korean national TB surveillance system database (TB outcomes). Information regarding LTBI treatment at private hospitals and public health centres is collected from NHI and PHIS databases, respectively. The screening data are cleaned, duplicates are removed, and, where appropriate, re-coded to analyse specific exposures and outcomes. The primary objective is to compare the number of active TB cases prevented within 2âyears between participants undergoing treatment and not undergoing treatment in the LTBI screening programme in congregate settings. Cascade of care for LTBI diagnosis and treatment will be evaluated among those with a positive LTBI test result. A Cox proportional hazards model will be applied to determine the risk factors for developing active TB.Ethics and disseminationThe protocol is approved by the institutional review boards of Incheon St. Maryâs Hospital, the Catholic University of Korea. Study results will be disseminated through peer-reviewed journals and conference presentations.Trial registration numberKCT000390
Geometry of Polynomials and Root-Finding via Path-Lifting
Using the interplay between topological, combinatorial, and geometric
properties of polynomials and analytic results (primarily the covering
structure and distortion estimates), we analyze a path-lifting method for
finding approximate zeros, similar to those studied by Smale, Shub, Kim, and
others. Given any polynomial, this simple algorithm always converges to a root,
except on a finite set of initial points lying on a circle of a given radius.
Specifically, the algorithm we analyze consists of iterating where the form a decreasing sequence of
real numbers and is chosen on a circle containing all the roots. We show
that the number of iterates required to locate an approximate zero of a
polynomial depends only on (where is
the radius of convergence of the branch of taking to a root
) and the logarithm of the angle between and certain critical
values. Previous complexity results for related algorithms depend linearly on
the reciprocals of these angles. Note that the complexity of the algorithm does
not depend directly on the degree of , but only on the geometry of the
critical values.
Furthermore, for any polynomial with distinct roots, the average number
of steps required over all starting points taken on a circle containing all the
roots is bounded by a constant times the average of . The
average of over all polynomials with roots in the
unit disk is . This algorithm readily generalizes to
finding all roots of a polynomial (without deflation); doing so increases the
complexity by a factor of at most .Comment: 44 pages, 12 figure
Non-Newtonian Couette-Poiseuille flow of a dilute gas
The steady state of a dilute gas enclosed between two infinite parallel
plates in relative motion and under the action of a uniform body force parallel
to the plates is considered. The Bhatnagar-Gross-Krook model kinetic equation
is analytically solved for this Couette-Poiseuille flow to first order in the
force and for arbitrary values of the Knudsen number associated with the shear
rate. This allows us to investigate the influence of the external force on the
non-Newtonian properties of the Couette flow. Moreover, the Couette-Poiseuille
flow is analyzed when the shear-rate Knudsen number and the scaled force are of
the same order and terms up to second order are retained. In this way, the
transition from the bimodal temperature profile characteristic of the pure
force-driven Poiseuille flow to the parabolic profile characteristic of the
pure Couette flow through several intermediate stages in the Couette-Poiseuille
flow are described. A critical comparison with the Navier-Stokes solution of
the problem is carried out.Comment: 24 pages, 5 figures; v2: discussion on boundary conditions added; 10
additional references. Published in a special issue of the journal "Kinetic
and Related Models" dedicated to the memory of Carlo Cercignan
Positive thyroid transcription factor 1 staining strongly correlates with survival of patients with adenocarcinoma of the lung
This study investigated the relation between positive thyroid transcription factor 1 (TTF1) staining and survival of patients affected by primary adenocarcinoma (ADC) of the lung. Pathological tissue from consecutive ADC patients was collected from 2002 to 2004. The anti-TTF1 antibody (8G7G3/1, dilution of 1/200) was used. Thyroid transcription factor 1 staining was assessed for each tumour as positive or negative. Probability of survival was estimated by KaplanâMeier and difference tested by log-rank test. A Cox's regression multivariate analysis was carried out. In all, 106 patients were studied (66% male, 69% PS0â1, 83% with stage III or IV). Tumours expressed positive TTF1 staining in 66% of cases. Multivariate analysis demonstrated an independent lower risk of death for patients whose tumour expresses positive TTF1 staining (HR=0.51, 95% CI 0.30â0.85; P=0.01) and higher grade of differentiation (HR=0.40, 95% CI 0.24â0.68; P=0.001). In conclusion, positive TTF1 staining strongly and independently correlates with survival of patients with primary ADC of the lung
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