Assisted reproduction in Hong Kong: Status in the 1990s

Information on assisted reproduction in Hong Kong for the period from January 1992 to December 1993 was collected from the three centres that offer assisted reproduction. Altogether, 912 treatment cycles of in vitro fertilisation and embryo transfer, 158 treatment cycles of gamete intrafallopian transfer, and 87 cycles of zygote intrafallopian transfer were initiated during this period. The delivery rates per cycle started were 8.4% for in vitro fertilisation, 29.1% for gamete intrafallopian transfer, and 13.8% for zygote intrafallopian transfer. During the same period, 233 cycles of replacement of frozen thawed embryos were completed with a delivery rate of 11.2% per cycle. Pregnancies were also achieved using oocyte donation and micromanipulation techniques.published_or_final_versio

Search for the Higgs boson in the all-hadronic final state using the CDF II detector

We report on a search for the production of the Higgs boson decaying to two bottom quarks accompanied by two additional quarks. The data sample used corresponds to an integrated luminosity of approximately 4  fb-1 of pp̅ collisions at √s=1.96  TeV recorded by the CDF II experiment. This search includes twice the integrated luminosity of the previous published result, uses analysis techniques to distinguish jets originating from light flavor quarks and those from gluon radiation, and adds sensitivity to a Higgs boson produced by vector boson fusion. We find no evidence of the Higgs boson and place limits on the Higgs boson production cross section for Higgs boson masses between 100  GeV/c2 and 150  GeV/c2 at the 95% confidence level. For a Higgs boson mass of 120  GeV/c2, the observed (expected) limit is 10.5 (20.0) times the predicted standard model cross section.Peer reviewe

Nonlinear beam self-cleaning in a coupled cavity composite laser based on multimode fiber

We study a coupled cavity laser configuration where a passively Q-switched Nd:YAG microchip laser is combined with an extended cavity, including a doped multimode fiber. For appropriate coupling levels with the extended cavity, we observed that beam selfcleaning was induced in the multimode fiber thanks to nonlinear modal coupling, leading to a quasi-single mode laser output. In the regime of beam self-cleaning, laser pulse duration was reduced from 525 to 225 ps. We also observed a Q-switched mode-locked operation, where spatial self-cleaning was accompanied by far-detuned nonlinear frequency conversion in the active multimode fiber

Measurement of the WW+WZ Production Cross Section Using a Matrix Element Technique in Lepton + Jets Events

Submitted to Phys. Rev. DWe present a measurement of the $WW+WZ$ production cross section observed in a final state consisting of an identified electron or muon, two jets, and missing transverse energy. The measurement is carried out in a data sample corresponding to up to 4.6~fb$^{-1}$ of integrated luminosity at $\sqrt{s} = 1.96$ TeV collected by the CDF II detector. Matrix element calculations are used to separate the diboson signal from the large backgrounds. The $WW+WZ$ cross section is measured to be $17.4\pm3.3$~pb, in agreement with standard model predictions. A fit to the dijet invariant mass spectrum yields a compatible cross section measurement.We present a measurement of the WW+WZ production cross section observed in a final state consisting of an identified electron or muon, two jets, and missing transverse energy. The measurement is carried out in a data sample corresponding to up to 4.6  fb-1 of integrated luminosity at √s=1.96  TeV collected by the CDF II detector. Matrix element calculations are used to separate the diboson signal from the large backgrounds. The WW+WZ cross section is measured to be 17.4±3.3  pb in agreement with standard model predictions. A fit to the dijet invariant mass spectrum yields a compatible cross section measurement.Peer reviewe

Updated Search for the Flavor-Changing Neutral-Current Decay D^0 \to {\mu} + {\mu}-

8 pages, 5 figures, RevTex format, submitted to PRDWe report on a search for the flavor-changing neutral-current decay D0 \to {\mu}+ {\mu}- in pp collisions at \surd s = 1.96 TeV using 360 pb-1 of integrated luminosity collected by the CDF II detector at the Fermilab Tevatron collider. A displaced vertex trigger selects long-lived D0 candidates in the {\mu}+ {\mu}-, {\pi}+{\pi}-, and K-{\pi}+ decay modes. We use the Cabibbo-favored D0 \to K-{\pi}+ channel to optimize the selection criteria in an unbiased manner, and the kinematically similar D0 \to{\pi}+ {\pi}- channel for normalization. We set an upper limit on the branching fraction (D0 --> {\mu}+ {\mu}-)We report on a search for the flavor-changing neutral-current decay D0→μ+μ- in pp̅ collisions at √s=1.96  TeV using 360  pb-1 of integrated luminosity collected by the CDF II detector at the Fermilab Tevatron collider. A displaced vertex trigger selects long-lived D0 candidates in the μ+μ-, π+π-, and K-π+ decay modes. We use the Cabibbo-favored D0→K-π+ channel to optimize the selection criteria in an unbiased manner, and the kinematically similar D0→π+π- channel for normalization. We set an upper limit on the branching fraction B(D0→μ+μ-)<2.1×10-7(3.0×10-7) at the 90% (95%) confidence level.Peer reviewe

Search for New Heavy Particles Decaying to Z0 Z0 to llll, lljj in p pbar Collisions at Sqrt(s) = 1.96 TeV

We report on a search for anomalous production of Z boson pairs through a massive resonance decay in data corresponding to 2.5-2.9 fb^-1 of integrated luminosity in p pbar collisions at 1.96 TeV using the CDF II detector at the Fermilab Tevatron. This analysis, with more data and channels where the Z bosons decay to muons or jets, supersedes the 1.1 fb^-1 four-electron channel result previously published by CDF. In order to maintain high efficiency for muons, we use a new forward tracking algorithm and muon identification requirements optimized for these high signal-to-background channels. Predicting the dominant backgrounds in each channel entirely from sideband data samples, we observe four-body invariant mass spectra above 300 GeV/c^2 that are consistent with background. We set limits using the acceptance for a massive graviton resonance that are 7-20 times stronger than the previously published direct limits on resonant ZZ production.Comment: for submission to Phys. Rev.

Search for New Physics with a Dijet plus Missing Transverse Energy Signature in p-pbar Collisions at sqrt(s) = 1.96 TeV

submitted to Phys. Rev. LettWe present results of a signature-based search for new physics using a dijet plus missing transverse energy data sample collected in 2 fb-1 of p-pbar collisions at sqrt(s) = 1.96 TeV with the CDF II detector at the Fermilab Tevatron. We observe no significant event excess with respect to the standard model prediction and extract a 95% C.L. upper limit on the cross section times acceptance for a potential contribution from a non-standard model process. Based on this limit the mass of a first or second generation scalar leptoquark is constrained to be above 187 GeV/c^2.We present results of a signature-based search for new physics using a dijet plus missing transverse energy (ET) data sample collected in 2  fb-1 of pp̅ collisions at √s=1.96  TeV with the CDF II detector at the Fermilab Tevatron. We observe no significant event excess with respect to the standard model prediction and extract a 95% C.L. upper limit on the cross section times acceptance for a potential contribution from a nonstandard model process. The search is made by using novel, data-driven techniques for estimating backgrounds that are applicable to first searches at the LHC.Peer reviewe

Search for the Production of Scalar Bottom Quarks in ppbar collisions at sqrt(s) = 1.96 TeV

7 pages, 2 figures Submitted to PRL on 16th MayWe report on a search for direct scalar bottom quark (sbottom) pair production in $p \bar{p}$ collisions at $\sqrt{s}=1.96$~TeV, in events with large missing transverse energy and two jets of hadrons in the final state, where at least one of the jets is required to be identified as originating from a $b$ quark. The study uses a CDF Run~II data sample corresponding to 2.65~fb${}^{-1}$ of integrated luminosity. The data are in agreement with the standard model. In an R-parity conserving minimal supersymmetric scenario, and assuming that the sbottom decays exclusively into a bottom quark and a neutralino, 95$\%$ confidence-level upper limits on the sbottom pair production cross section of 0.1~pb are obtained. For neutralino masses below 70~GeV/$c^2$, sbottom masses up to 230~GeV/$c^2$ are excluded at 95$\%$ confidence level.We report on a search for direct scalar bottom quark (sbottom) pair production in pp̅ collisions at √s=1.96  TeV, in events with large missing transverse energy and two jets of hadrons in the final state, where at least one of the jets is required to be identified as originating from a b quark. The study uses a collider detector at Fermilab Run II data sample corresponding to 2.65  fb-1 of integrated luminosity. The data are in agreement with the standard model. In an R-parity conserving minimal supersymmetric scenario, and assuming that the sbottom decays exclusively into a bottom quark and a neutralino, 95% confidence-level upper limits on the sbottom pair production cross section of 0.1 pb are obtained. For neutralino masses below 70  GeV/c2, sbottom masses up to 230  GeV/c2 are excluded at 95% confidence level.Peer reviewe

Value of intracoronary Doppler for guiding percutaneous interventions

Following the rapid developments in computer software directed towards the anatomical assessment of coronary arteries by quantitative coronary angiography (QCA), interventional cardiologist felt that the anatomical information obtained was sufficient for clinical decision-making. However, further down the line, it became clear that QCA presented some limitations especially in patients with diffuse coronary artery atherosclerosis. In addition, the presence of haziness at the dilated area precluded an accurate estimate of the acute angioplasty results. The latter was further supporter by a lack of correlation observed between the QCA and coronar