167 research outputs found

    Remarkable convergent evolution in specialized parasitic Thecostraca (Crustacea)

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    <p>Abstract</p> <p>Background</p> <p>The Thecostraca are arguably the most morphologically and biologically variable group within the Crustacea, including both suspension feeders (Cirripedia: Thoracica and Acrothoracica) and parasitic forms (Cirripedia: Rhizocephala, Ascothoracida and Facetotecta). Similarities between the metamorphosis found in the Facetotecta and Rhizocephala suggests a common evolutionary origin, but until now no comprehensive study has looked at the basic evolution of these thecostracan groups.</p> <p>Results</p> <p>To this end, we collected DNA sequences from three nuclear genes [18S rRNA (2,305), 28S rRNA (2,402), Histone H3 (328)] and 41 larval characters in seven facetotectans, five ascothoracidans, three acrothoracicans, 25 rhizocephalans and 39 thoracicans (ingroup) and 12 Malacostraca and 10 Copepoda (outgroup). Maximum parsimony, maximum likelihood and Bayesian analyses showed the Facetotecta, Ascothoracida and Cirripedia each as monophyletic. The better resolved and highly supported DNA maximum likelihood and morphological-DNA Bayesian analysis trees depicted the main phylogenetic relationships within the Thecostraca as (Facetotecta, (Ascothoracida, (Acrothoracica, (Rhizocephala, Thoracica)))).</p> <p>Conclusion</p> <p>Our analyses indicate a convergent evolution of the very similar and highly reduced slug-shaped stages found during metamorphosis of both the Rhizocephala and the Facetotecta. This provides a remarkable case of convergent evolution and implies that the advanced endoparasitic mode of life known from the Rhizocephala and strongly indicated for the Facetotecta had no common origin. Future analyses are needed to determine whether the most recent common ancestor of the Thecostraca was free-living or some primitive form of ectoparasite.</p

    Chlorpromazine for schizophrenia: a Cochrane systematic review of 50 years of randomised controlled trials

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    BACKGROUND: Chlorpromazine (CPZ) remains one of the most common drugs used for people with schizophrenia worldwide, and a benchmark against which other treatments can be evaluated. Quantitative reviews are rare; this one evaluates the effects of chlorpromazine in the treatment of schizophrenia in comparison with placebo. METHODS: We sought all relevant randomised controlled trials (RCT) comparing chlorpromazine to placebo by electronic and reference searching, and by contacting trial authors and the pharmaceutical industry. Data were extracted from selected trials and, where possible, synthesised and random effects relative risk (RR), the number needed to treat (NNT) and their 95% confidence intervals (CI) calculated. RESULTS: Fifty RCTs from 1955–2000 were included with 5276 people randomised to CPZ or placebo. They constitute 2008 person-years spent in trials. Meta-analysis of these trials showed that chlorpromazine promotes a global improvement (n = 1121, 13 RCTs, RR 0.76 CI 0.7 to 0.9, NNT 7 CI 5 to 10), although a considerable placebo response is also seen. People allocated to chlorpromazine tended not to leave trials early in both the short (n = 945, 16 RCTs, RR 0.74 CI 0.5 to 1.1) and medium term (n = 1861, 25 RCTs, RR 0.79 CI 0.6 to 1.1). There were, however, many adverse effects. Chlorpromazine is sedating (n = 1242, 18 RCTs, RR 2.3 CI 1.7 to 3.1, NNH 6 CI 5 to 8), increases a person's chances of experiencing acute movement disorders, Parkinsonism and causes low blood pressure with dizziness and dry mouth. CONCLUSION: It is understandable why the World Health Organization (WHO) have endorsed and included chlorpromazine in their list of essential drugs for use in schizophrenia. Low- and middle-income countries may have more complete evidence upon which to base their practice compared with richer nations using recent innovations

    Search for B+ -> l+ nu gamma decays with hadronic tagging using the full Belle data sample

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    We search for the decay B+ -> l+ nu gamma with l+ = e+ or mu+ using the full Belle data set of 772 x 10^6 BBbar pairs, collected at the Y(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider. We reconstruct one B meson in a hadronic decay mode and search for the B+ -> l+ nu gamma decay in the remainder of the event. We observe no significant signal within the phase space of E_gamma^sig > 1 GeV and obtain upper limits of BR(B+ -> e+ nu gamma) mu+ nu gamma) l+ nu gamma) < 3.5 x 10^-6 at 90 % credibility level.Comment: Submitted to Phys. Rev.

    Measurement of the branching ratio of BˉD()τνˉτ\bar{B} \to D^{(\ast)} \tau^- \bar{\nu}_\tau relative to BˉD()νˉ\bar{B} \to D^{(\ast)} \ell^- \bar{\nu}_\ell decays with hadronic tagging at Belle

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    We report a measurement of the branching fraction ratios R(D(*)) of Bbar -> D(*) tau- nubar_tau relative to Bbar -> D()* l- nubar_l (where l = e or mu) using the full Belle data sample of 772 x 10^6 BBbar pairs collected at the Y(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider. The measured values are R(D)= 0.375 +- 0.064(stat.) +- 0.026(syst.) and R(D*) = 0.293 +- 0.038(stat.) +- 0.015(syst.). The analysis uses hadronic reconstruction of the tag-side B meson and purely leptonic tau decays. The results are consistent with earlier measurements and do not show a significant deviation from the standard model prediction.Comment: Accepted for publication in Phys.Rev.

    First Observation of Doubly Cabibbo-Suppressed Decay of a Charmed Baryon: Λc+pK+π\Lambda^{+}_{c} \rightarrow p K^{+} \pi^{-}

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    We report the first observation of the decay Λc+pK+π\Lambda^{+}_{c} \rightarrow p K^{+} \pi^{-} using a 980 fb1\mathrm{fb^{-1}} data sample collected by the Belle detector at the KEKB asymmetric-energy e+ee^{+}e^{-} collider. This is the first doubly Cabibbo-suppressed decay of a charmed baryon to be observed. We measure the branching ratio of this decay with respect to its Cabibbo-favored counterpart to be B(Λc+pK+π)/B(Λc+pKπ+)=(2.35±0.27±0.21)×103\mathcal{B}(\Lambda^{+}_{c} \rightarrow p K^{+} \pi^{-})/\mathcal{B}(\Lambda^{+}_{c} \rightarrow p K^{-} \pi^{+})=(2.35\pm0.27\pm0.21)\times10^{-3}, where the uncertainties are statistical and systematic, respectively.Comment: 6 pages, 3 figure

    Search for Bhννˉ\boldsymbol{B\to h\nu\bar{\nu}} decays with semileptonic tagging at Belle

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    We present the results of a search for the rare decays BhννB\to h\nu\overline{\nu}, where hh stands for K+,KS0,K+,K0,π+,π0,ρ+K^+,\:K^0_{\mathrm{S}},\:K^{\ast +},\:K^{\ast 0},\:\pi^+,\:\pi^0,\:\rho^+ and ρ0\rho^{0}. The results are obtained with 772×106772\times10^{6} BBB\overline{B} pairs collected with the Belle detector at the KEKB e+ee^+ e^- collider. We reconstruct one BB meson in a semileptonic decay and require a single hh meson but nothing else on the signal side. We observe no significant signal and set upper limits on the branching fractions. The limits set on the BKS0ννB\to K^0_{\mathrm{S}}\nu\overline{\nu}, B0K0ννB^0\to K^{*0}\nu\overline{\nu}, Bπ+ννB\to \pi^+\nu\overline{\nu}, B0π0ννB^0\to\pi^0\nu\overline{\nu}, B+ρ+ννB^+\to\rho^+\nu\overline{\nu}, and B0ρ0ννB^0\to\rho^0\nu\overline{\nu} channels are the world's most stringent.Comment: Submitted to PR

    Measurement of the τ\tau lepton polarization and R(D)R(D^*) in the decay BˉDτνˉτ\bar{B} \to D^* \tau^- \bar{\nu}_\tau

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    We report the first measurement of the τ\tau lepton polarization Pτ(D)P_\tau(D^*) in the decay BˉDτνˉτ\bar{B} \rightarrow D^* \tau^- \bar{\nu}_\tau as well as a new measurement of the ratio of the branching fractions R(D)=B(BˉDτνˉτ)/B(BˉDνˉ)R(D^{*}) = \mathcal{B}(\bar {B} \rightarrow D^* \tau^- \bar{\nu}_\tau) / \mathcal{B}(\bar{B} \rightarrow D^* \ell^- \bar{\nu}_\ell), where \ell^- denotes an electron or a muon, and the τ\tau is reconstructed in the modes τπντ\tau^- \rightarrow \pi^- \nu_\tau and τρντ\tau^- \rightarrow \rho^- \nu_\tau. We use the full data sample of 772×106772 \times 10^6 BBˉB{\bar B} pairs recorded with the Belle detector at the KEKB electron-positron collider. Our results, Pτ(D)=0.38±0.51(stat.)0.16+0.21(syst.)P_\tau(D^*) = -0.38 \pm 0.51 {\rm (stat.)} ^{+0.21}_{-0.16} {\rm (syst.)} and R(D)=0.270±0.035(stat.)0.025+0.028(syst.)R(D^*) = 0.270 \pm 0.035{\rm (stat.)} ^{+0.028}_{-0.025}{\rm (syst.)}, are consistent with the theoretical predictions of the Standard Model.Comment: 7 pages, 2 figures, submitted to Physical Review Letters; one figure was removed from the first versio

    Angular analysis of B0K(892)0+B^0 \to K^\ast(892)^0 \ell^+ \ell^-

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    We present a measurement of angular observables, P4P_4', P5P_5', P6P_6', P8P_8', in the decay B0K(892)0+B^0 \to K^\ast(892)^0 \ell^+ \ell^-, where +\ell^+\ell^- is either e+ee^+e^- or μ+μ\mu^+\mu^-. The analysis is performed on a data sample corresponding to an integrated luminosity of 711 fb1711~\mathrm{fb}^{-1} containing 772×106772\times 10^{6} BBˉB\bar B pairs, collected at the Υ(4S)\Upsilon(4S) resonance with the Belle detector at the asymmetric-energy e+ee^+e^- collider KEKB. Four angular observables, P4,5,6,8P_{4,5,6,8}' are extracted in five bins of the invariant mass squared of the lepton system, q2q^2. We compare our results for P4,5,6,8P_{4,5,6,8}' with Standard Model predictions including the q2q^2 region in which the LHCb collaboration reported the so-called P5P_5' anomaly.Comment: Conference paper for LHC Ski 2016. SM prediction for P6P_{6}' corrected and reference for arXiv:1207.2753 adde
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