6,166 research outputs found
No Evidence for a Aystematic FEII Emission Line Redshift in Type 1 AGN
We test the recent claim by Hu et al. (2008) that FeII emission in Type 1 AGN
shows a systematic redshift relative to the local source rest frame and
broad-line Hbeta. We compile high s/n median composites using SDSS spectra from
both the Hu et al. sample and our own sample of the 469 brightest DR5 spectra.
Our composites are generated in bins of FWHM Hbeta and FeII strength as defined
in our 4D Eigenvector 1 (4DE1) formalism. We find no evidence for a systematic
FeII redshift and consistency with previous assumptions that FeII shift and
width (FWHM) follow Hbeta shift and FWHM in virtually all sources. This result
is consistent with the hypothesis that FeII emission (quasi-ubiquitous in type
1 sources) arises from a broad-line region with geometry and kinematics the
same as that producing the Balmer lines.Comment: 12 pages, 1 table, 1 figure - accepted for publication in ApJ Letter
The Physics of Heavy Flavours at SuperB
This is a review of the SuperB project, covering the accelerator, detector,
and highlights of the broad physics programme. SuperB is a flavour factory
capable of performing precision measurements and searches for rare and
forbidden decays of , , and
particles. These results can be used to test fundamental symmetries and
expectations of the Standard Model, and to constrain many different
hypothesised types of new physics. In some cases these measurements can be used
to place constraints on the existence of light dark matter and light Higgs
particles with masses below . The potential impact of the
measurements that will be made by SuperB on the field of high energy physics is
also discussed in the context of data taken at both high energy in the region
around the \Upsilon({\mathrm{4S}})$, and near charm threshold.Comment: 49 pages, topical review submitted to J. Phys
Association Between Biomarkers of Ovarian Reserve and Infertility Among Older Women of Reproductive Age
Despite lack of evidence of their utility, biomarkers of ovarian reserve are being promoted as potential markers of reproductive potential or “fertility tests.
Antimüllerian Hormone as a Predictor of Natural Fecundability in Women Aged 30–42 Years
To generate estimates of the association between markers of ovarian aging and natural fertility in a community sample at risk for ovarian aging
Renaissance of the ~1 TeV Fixed-Target Program
This document describes the physics potential of a new fixed-target program
based on a ~1 TeV proton source. Two proton sources are potentially available
in the future: the existing Tevatron at Fermilab, which can provide 800 GeV
protons for fixed-target physics, and a possible upgrade to the SPS at CERN,
called SPS+, which would produce 1 TeV protons on target. In this paper we use
an example Tevatron fixed-target program to illustrate the high discovery
potential possible in the charm and neutrino sectors. We highlight examples
which are either unique to the program or difficult to accomplish at other
venues.Comment: 31 pages, 11 figure
A model based approach for complex dynamic decision-making
Current state-of-the-practice and state-of-the-art of decision-making aids are inadequate for modern organisations that deal with significant uncertainty and business dynamism. This paper highlights the limitations of prevalent decision-making aids and proposes a model-based approach that advances the modelling abstraction and analysis machinery for complex dynamic decision-making. In particular, this paper proposes a meta-model to comprehensively represent organisation, establishes the relevance of model-based simulation technique as analysis means, introduces the advancements over actor technology to address analysis needs, and proposes a method to utilise proposed modelling abstraction, analysis technique, and analysis machinery in an effective and convenient manner. The proposed approach is illustrated using a near real-life case-study from a business process outsourcing organisation
Urinary Follicle-Stimulating Hormone as a Measure of Natural Fertility in a Community Cohort
High serum follicle-stimulating hormone (FSH) levels have been associated with diminished ovarian reserve; however, the association between high urinary FSH and reduced natural fertility has yet to be established. We sought to characterize the relationship between a single or multiple measurements of early follicular phase urinary FSH and fertility. Women (n = 209), 30 to 44 years old with no history of infertility, who had been trying to conceive for less than 3 months, provided early follicular phase urine. Participants subsequently kept a diary to record bleeding and intercourse and conducted standardized pregnancy testing for up to 6 months. A subset of women (N = 95) collected urine on cycle day 3 for up to 6 cycles. Urine was analyzed for FSH and creatinine (cr) corrected. Proportional hazard models were used to calculate fecundability ratios (FRs). Urinary FSH levels across cycles from the same woman were highly correlated (adjusted intraclass correlation = .77); within-woman variance was 3-fold lower than variance among women. Women with an initial urinary FSH level <7 mIU/mg cr exhibited a nonsignificant reduction in the probability of pregnancy (adjusted FR 0.71, 95% confidence interval [CI]: 0.45-1.13), as did women with elevated urinary FSH (≥12 mIU/mg cr; adjusted FR 0.78, 95% CI: 0.46-1.32). Using the most recent or maximum urinary FSH value did not strengthen the association. In the general population, urinary FSH levels appear to be nonlinearly associated with fertility; however, broad CIs indicate a lack of statistical significance. Repetitive testing appears to be of little benefit
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