Objectives: The incidence of appendix testis has been shown to be 76% in descended and 24% in undescended testis in our previous intraoperative survey. To determine the possible role of the appendix ...testis in the process of testicular migration, we compared the androgen and estrogen receptor status of appendix testis in descended and undescended testes.
Methods: Thirty‐seven appendix testes were collected intraoperatively and the expression of androgen and estrogen receptors were examined with immunostaining and immunofluorescence labeling. Based on the diagnosis, the specimens were divided into three groups. Group H (groin hernia, n = 11, as a group of descended testis), Group AU (acquired undescended testis, n = 14), and Group CU (congenital undescended testis, n = 12).
Results: The testicular appendages were found to express both androgen and estrogen receptors in Group H and Group AU, but specimens in Group CU were only estrogen receptor positive, whereas androgen receptors were not present.
Conclusion: The presence of the androgen receptor in the appendix testis of the descended testes and acquired undescended testes and its absence in patients with congenital undescended testis suggests that the appendix testis might play a role in the process of testicular descent.
Hadronic event shape distributions from e super(+)e super(-) annihilation measured by the OPAL experiment at centre-of-mass energies between 91 GeV and 209 GeV are used to determine the strong ...coupling alpha sub(S). The results are based on QCD predictions complete to the next-to-next-to-leading order (NNLO), and on NNLO calculations matched to the resummed next-to-leading-log-approximation terms (NNLO+NLLA). The combined NNLO result from all variables and centre-of-mass energies is while the combined NNLO+NLLA result is The completeness of the NNLO and NNLO+NLLA results with respect to missing higher order contributions, studied by varying the renormalization scale, is improved compared to previous results based on NLO or NLO+NLLA predictions only. The observed energy dependence of alpha sub(S) agrees with the QCD prediction of asymptotic freedom and excludes the absence of running.
A search is made for charged Higgs bosons predicted by Two-Higgs-Doublet extensions of the Standard Model (2HDM) using electron-positron collision data collected by the OPAL experiment at
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\begin{document}$\sqrt{s}=189\mbox{--}209\ \mbox{GeV}$\end{document}
, corresponding to an integrated luminosity of approximately 600 pb
−1
. Charged Higgs bosons are assumed to be pair-produced and to decay into
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,
τν
τ
or AW
±
. No signal is observed. Model-independent limits on the charged Higgs-boson production cross section are derived by combining these results with previous searches at lower energies. Under the assumption
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\begin{document}$\mathrm{BR} (\mathrm{H}^{\pm} \to \tau\nu_{\tau}) + \mathrm{BR} (\mathrm{H}^{\pm} \to \mathrm{q} \bar{\mathrm{q}}) = 1$\end{document}
, motivated by general 2HDM type II models, excluded areas on the
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\begin{document}$m_{\mathrm{H}^{\pm}} , \mathrm{BR} (\mathrm {H}^{\pm} \to \tau\nu_{\tau})$\end{document}
plane are presented and charged Higgs bosons are excluded up to a mass of 76.3 GeV at 95 % confidence level, independent of the branching ratio BR(H
±
→
τν
τ
). A scan of the 2HDM type I model parameter space is performed and limits on the Higgs-boson masses
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and
m
A
are presented for different choices of tan
β
.
A search for single top quark production via flavour changing neutral currents (FCNC) was performed with data collected by the OPAL detector at the e+e− collider LEP. Approximately 600 pb−1 of data ...collected at s=189–209 GeV were used to search for the FCNC process e+e−→tc(u)→bWc(u). This analysis is sensitive to the leptonic and the hadronic decay modes of the W boson. No evidence for a FCNC process is observed. Upper limits at the 95% confidence level on the single top production cross-section as a function of the centre-of-mass energy are derived. Limits on the anomalous coupling parameters κγ and κZ are determined from these results.
Searches for a scalar top quark and a scalar bottom quark have been performed using a data sample of 438 pb−1 at centre-of-mass energies of s=192–209 GeV collected with the OPAL detector at LEP. No ...evidence for a signal was found. The 95% confidence level lower limit on the scalar top quark mass is 97.6 GeV if the mixing angle between the supersymmetric partners of the left- and right-handed states of the top quark is zero. When the scalar top quark decouples from the Z0 boson, the lower limit is 95.7 GeV. These limits were obtained assuming that the scalar top quark decays into a charm quark and the lightest neutralino, and that the mass difference between the scalar top quark and the lightest neutralino is larger than 10 GeV. The complementary decay mode of the scalar top quark decaying into a bottom quark, a charged lepton and a scalar neutrino has also been studied. The lower limit on the scalar top quark mass is 96.0 GeV for this decay mode, if the mass difference between the scalar top quark and the scalar neutrino is greater than 10 GeV and if the mixing angle of the scalar top quark is zero. From a search for the scalar bottom quark, a mass limit of 96.9 GeV was obtained if the mass difference between the scalar bottom quark and the lightest neutralino is larger than 10 GeV.
A search is performed for Higgs bosons decaying into invisible final states, produced in association with a Z0 boson in e+e− collisions at energies between 183 and 209 GeV. The search is based on ...data samples collected by the OPAL detector at LEP corresponding to an integrated luminosity of about 660 pb−1. The analysis aims to select events containing the hadronic decay products of the Z0 boson and large missing momentum, as expected from Higgs boson decay into a pair of stable weakly interacting neutral particles, such as the lightest neutralino in the Minimal Supersymmetric Standard Model. The same analysis is applied to a search for nearly invisible Higgs boson cascade decays into stable weakly interacting neutral particles. No excess over the expected background from Standard Model processes is observed. Limits on the production of invisibly decaying Higgs bosons produced in association with a Z0 boson are derived. Assuming a branching ratio BR(h0→invisible)=1, a lower limit of 108.2 GeV is placed on the Higgs boson mass at the 95% confidence level. Limits on the production of nearly invisibly decaying Higgs bosons are also obtained.
Inclusive jet production (e+e−→e+e−+jet+X) is studied in collisions of quasi-real photons radiated by the LEP beams at e+e− centre-of-mass energies see from 189 to 209 GeV. Jets are reconstructed ...using the k⊥ jet algorithm. The inclusive differential cross-section is measured as a function of the jet transverse momentum, pTjet, in the range 5<pTjet<40 GeV for pseudo-rapidities, ηjet, in the range −1.5<ηjet<1.5. The results are compared to predictions of perturbative QCD in next-to-leading order in the strong coupling constant.
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