3,055 research outputs found
The Relationship Between Leadership Style & Demographic Characteristics Of Taiwanese Executives
The purpose of this study was to investigate the relationship between Taiwanese executives leadership style and demographic characteristics in the high-tech Kun-Shan region of Mainland China using the leader Behavior Description Questionnaire (LBDQ)
Rofecoxib and cardiovascular adverse events in adjuvant treatment of colorectal cancer
Background
Selective cyclooxygenase inhibitors may retard the progression of cancer, but they
have enhanced thrombotic potential. We report on cardiovascular adverse events in
patients receiving rofecoxib to reduce rates of recurrence of colorectal cancer.
Methods
All serious adverse events that were cardiovascular thrombotic events were reviewed
in 2434 patients with stage II or III colorectal cancer participating in a randomized,
placebo-controlled trial of rofecoxib, 25 mg daily, started after potentially curative
tumor resection and chemotherapy or radiotherapy as indicated. The trial was terminated
prematurely owing to worldwide withdrawal of rofecoxib. To examine possible
persistent risks, we examined cardiovascular thrombotic events reported up to 24
months after the trial was closed.
Results
The median duration of active treatment was 7.4 months. The 1167 patients receiving
rofecoxib and the 1160 patients receiving placebo were well matched, with a median
follow-up period of 33.0 months (interquartile range, 27.6 to 40.1) and 33.4 months
(27.7 to 40.4), respectively. Of the 23 confirmed cardiovascular thrombotic events,
16 occurred in the rofecoxib group during or within 14 days after the treatment
period, with an estimated relative risk of 2.66 (from the Cox proportional-hazards
model; 95% confidence interval [CI], 1.03 to 6.86; P = 0.04). Analysis of the Antiplatelet
Trialists’ Collaboration end point (the combined incidence of death from
cardiovascular, hemorrhagic, and unknown causes; of nonfatal myocardial infarction;
and of nonfatal ischemic and hemorrhagic stroke) gave an unadjusted relative
risk of 1.60 (95% CI, 0.57 to 4.51; P = 0.37). Fourteen more cardiovascular thrombotic
events, six in the rofecoxib group, were reported within the 2 years after trial
closure, with an overall unadjusted relative risk of 1.50 (95% CI, 0.76 to 2.94;
P = 0.24). Four patients in the rofecoxib group and two in the placebo group died
from thrombotic causes during or within 14 days after the treatment period, and
during the follow-up period, one patient in the rofecoxib group and five patients in
the placebo group died from cardiovascular causes.
Conclusions
Rofecoxib therapy was associated with an increased frequency of adverse cardiovascular
events among patients with a median study treatment of 7.4 months’ duration.
(Current Controlled Trials number, ISRCTN98278138.
Role of lepton flavor violating (LFV) muon decay in Seesaw model and LSND
The aim of the work is to study LFV in a newly proposed Seesaw model of
neutrino mass and to see whether it could explain LSND excess. The motivation
of this Seesaw model was that there was no new physics beyond the TeV scale. By
studying \mu \to 3e in this model, it is shown that the upper bound on the
branching ratio requires Higgs mass m_{h} of a new scalar doublet with lepton
number L=-1 needed in the model has to be about 9 TeV. The predicted branching
ratio for \mu \to e\nu_{l}\bar{\nu}_{l} is too small to explain the LSND. PACS:
11.30.Hv, 14.60.PqComment: 05 pages, three figures, the version to appear in PR
Quantum Zeno effect in a probed downconversion process
The distorsion of a spontaneous downconvertion process caused by an auxiliary
mode coupled to the idler wave is analyzed. In general, a strong coupling with
the auxiliary mode tends to hinder the downconversion in the nonlinear medium.
On the other hand, provided that the evolution is disturbed by the presence of
a phase mismatch, the coupling may increase the speed of downconversion. These
effects are interpreted as being manifestations of quantum Zeno or anti-Zeno
effects, respectively, and they are understood by using the dressed modes
picture of the device. The possibility of using the coupling as a nontrivial
phase--matching technique is pointed out.Comment: 11 pages, 4 figure
Harmonization and standardization of data for a pan-European cohort on SARS- CoV-2 pandemic
The European project ORCHESTRA intends to create a new pan-European cohort to rapidly advance the knowledge of the effects and treatment of COVID-19. Establishing processes that facilitate the merging of heterogeneous clusters of retrospective data was an essential challenge. In addition, data from new ORCHESTRA prospective studies have to be compatible with earlier collected information to be efficiently combined. In this article, we describe how we utilized and contributed to existing standard terminologies to create consistent semantic representation of over 2500 COVID-19-related variables taken from three ORCHESTRA studies. The goal is to enable the semantic interoperability of data within the existing project studies and to create a common basis of standardized elements available for the design of new COVID-19 studies. We also identified 743 variables that were commonly used in two of the three prospective ORCHESTRA studies and can therefore be directly combined for analysis purposes. Additionally, we actively contributed to global interoperability by submitting new concept requests to the terminology Standards Development Organizations
Spallation Neutron Production by 0.8, 1.2 and 1.6 GeV Protons on various Targets
Spallation neutron production in proton induced reactions on Al, Fe, Zr, W,
Pb and Th targets at 1.2 GeV and on Fe and Pb at 0.8, and 1.6 GeV measured at
the SATURNE accelerator in Saclay is reported. The experimental
double-differential cross-sections are compared with calculations performed
with different intra-nuclear cascade models implemented in high energy
transport codes. The broad angular coverage also allowed the determination of
average neutron multiplicities above 2 MeV. Deficiencies in some of the models
commonly used for applications are pointed out.Comment: 20 pages, 32 figures, revised version, accepted fpr publication in
Phys. Rev.
Can lepton flavor violating interactions explain the LSND results?
If the atmospheric and the solar neutrino problem are both explained by
neutrino oscillations, and if there are only three light neutrinos, then all
mass-squared differences between the neutrinos are known. In such a case,
existing terrestrial neutrino oscillation experiments cannot be significantly
affected by neutrino oscillations, but, in principle there could be an anomaly
in the neutrino flux due to new neutrino interactions. We discuss how a
non-standard muon decay would modify the
neutrino production processes of these experiments. Since violation
is small for New Physics above the weak scale one can use related
flavor-violating charged lepton processes to constrain these decays in a model
independent way. We show that the upper bounds on ,
muonium-antimuonium conversion and rule out any observable
effect for the present experiments due to
for , respectively. Applying similar arguments to
flavor-changing semi-leptonic reactions we exclude the possibility that the
"oscillation signals" observed at LSND are due to flavor-changing interactions
that conserve total lepton number.Comment: 21 pages, 6 figures, Latex; minor correction
Lung Cancer Occurrence in Never-Smokers: An Analysis of 13 Cohorts and 22 Cancer Registry Studies
Michael Thun and colleagues pooled and analyzed comprehensive data on lung cancer incidence and death rates among never-smokers to examine what factors other than active smoking affect lung cancer risk
- …