123 research outputs found

    Fundamental and clinical evaluation of "SCC RIABEAD" kit for immuno radiometric assay of squamous cell carcinoma related antigen.

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    Classic vector control strategies target mosquitoes indoors as the main transmitters of malaria are indoor-biting and –resting mosquitoes. However, the intensive use of insecticide-treated bed-nets (ITNs) and indoor residual spraying have put selective pressure on mosquitoes to adapt in order to obtain human blood meals. Thus, early-evening and outdoor vector activity is becoming an increasing concern. This study assessed the effect of a deltamethrin-treated net (100 mg/m2) attached to a one-meter high fence around outdoor cattle enclosures on the number of mosquitoes landing on humans. Mosquitoes were collected from four cattle enclosures: Pen A – with cattle and no net; B – with cattle and protected by an untreated net; C – with cattle and protected by a deltamethrin-treated net; D – no cattle and no net. A total of 3217 culicines and 1017 anophelines were collected, of which 388 were Anopheles gambiae and 629 An. ziemanni. In the absence of cattle nearly 3 times more An. gambiae (p<0.0001) landed on humans. The deltamethrin-treated net significantly reduced (nearly three-fold, p<0.0001) culicine landings inside enclosures. The sporozoite rate of the zoophilic An. ziemanni, known to be a secondary malaria vector, was as high as that of the most competent vector An. gambiae; raising the potential of zoophilic species as secondary malaria vectors. After deployment of the ITNs a deltamethrin persistence of 9 months was observed despite exposure to African weather conditions. The outdoor use of ITNs resulted in a significant reduction of host-seeking culicines inside enclosures. Further studies investigating the effectiveness and spatial repellence of ITNs around other outdoor sites, such as bars and cooking areas, as well as their direct effect on vector-borne disease transmission are needed to evaluate its potential as an appropriate outdoor vector control tool for rural Africa

    GMCs and their Type classification in M74: Toward understanding star formation and cloud evolution

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    We investigated the giant molecular clouds (GMCs) in M74 (NGC 628) obtained by the PHANGS project. We applied the GMC Types according to the activity of star formation: Type I without star formation, Type II with Hα\alpha luminosity (LHαL_{\mathrm{H\alpha}}) smaller than 1037.5erg s110^{37.5} \mathrm{erg~s^{-1}}, and Type III with LHαL_{\mathrm{H\alpha}} greater than 1037.5erg s110^{37.5} \mathrm{erg~s^{-1}}. In total, 432 GMCs were identified, where the individual GMC Types are 65, 203, and 164, for Type I, Type II, and Type III, respectively. The size and mass of the GMCs range from 23 - 237 pc and 104.910^{4.9} - 107.110^{7.1} M_{\odot}, showing a trend that mass and radius increase from Type I to II to III. Clusters younger than 4 Myr and HII regions are found to be concentrated within 150 pc of a GMC, indicating a tight association of these young objects with the GMCs. The virial ratio tends to decrease from Type I to III, indicating that Type III GMCs are most relaxed gravitationally among the three. We interpret that GMCs evolve from Type I to III, as previously found in the LMC. The evolutionary timescales of the three Types are estimated to be 2 Myr, 6 Myr, and 4 Myr, respectively, on a steady state assumption, where we assume the timescale of Type III is equal to the age of the associated clusters, indicating a GMC lifetime of 12 Myr or longer. Chevance et al. (2020) investigated GMCs using the same PHANGS dataset of M74, while these authors did not define a GMC, reaching an evolutionary picture with a 20 Myr duration of the non-star forming phase, five times longer than 4 Myr. We compare the present results with those by Chevance et al. (2020) and argue that defining individual GMCs is essential to understanding GMC evolution.Comment: 33 pages, 17 figures, 5 tables

    Observation of Cabibbo-suppressed and W-exchange Lambda_c^+ baryon decays

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    We present measurements of the Cabibbo-suppressed decays Lambda_c^+ --> Lambda0 K+ and Lambda_c^+ --> Sigma0 K+ (both first observations), Lambda_c^+ --> Sigma+ K+ pi- (seen with large statistics for the first time), Lambda_c^+ --> p K+ K- and Lambda_c^+ --> p phi (measured with improved accuracy). Improved branching ratio measurements for the decays Lambda_c^+ --> Sigma+ K+ K- and Lambda_c^+ --> Sigma+ phi, which are attributed to W-exchange diagrams, are shown. We also present the first evidence for Lambda_c^+ --> Xi(1690)^0 K+ and set an upper limit on the non-resonant decay Lambda_c^+ --> Sigma+ K+ K-. This analysis was performed using 32.6 fb^{-1} of data collected by the Belle detector at the asymmetric e+ e- collider KEKB.Comment: Submitted to Phys. Lett. B. v2: A small correction to the Authorlist was made. An earlier version of this analysis was released as BELLE-CONF-0130, hep-ex/010800

    Measurement of the Branching Fraction for B->eta' K and Search for B->eta'pi+

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    We report measurements for two-body charmless B decays with an eta' meson in the final state. Using 11.1X10^6 BBbar pairs collected with the Belle detector, we find BF(B^+ ->eta'K^+)=(79^+12_-11 +-9)x10^-6 and BF(B^0 -> eta'K^0)=(55^+19_-16 +-8)x10^-6, where the first and second errors are statistical and systematic, respectively. No signal is observed in the mode B^+ -> eta' pi^+, and we set a 90% confidence level upper limit of BF(B^+-> eta'pi^+) eta'K^+- decays is investigated and a limit at 90% confidence level of -0.20<Acp<0.32 is obtained.Comment: Submitted to Physics Letters

    A Measurement of Lifetime Difference in D0D^0 Meson Decays

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    We report a measurement of the D0D^0-Dˉ0\bar{D}{}^0 mixing parameter yCPy_{CP} using 23.4 fb1^{-1} of data collected near the Υ\Upsilon(4S) resonance with the Belle detector at KEKB. yCPy_{CP} is measured from the lifetime difference of D0D^0 mesons decaying into the Kπ+K^-\pi^+ state and the CP even eigenstate KK+K^-K^+. We find yCP=(0.5±1.00.8+0.7)×102y_{CP}=(-0.5\pm 1.0{}^{+0.7}_{-0.8})\times10^{-2}, where the first error is statistical and the second systematic, corresponding to a 95% confidence interval 0.030<yCP<0.020-0.030 < y_{CP} < 0.020.Comment: 10 pages, 3 figure

    Search for Direct CP Violation in B -> K pi Decays

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    We search for direct CP violation in flavor specific B -> K pi decays by measuring the rate asymmetry between charge conjugate modes. The search is performed on a data sample of 11.1 million B B bar events recorded on the Upsilon(4S) resonance by the Belle experiment at KEKB. We measure 90% confidence intervals in the partial rate asymmetry A_CP of -0.25 < A_CP(K-/+ pi+/-) < 0.37, -0.40 < A_CP(K-/+ pi^0) < 0.36, and -0.53 < A_CP(K^0 pi-/+) < 0.82. By combining the K-/+ pi+/- and K-/+ pi^0 final states, we conclude that -0.22 < A_CP[K-/+(pi+/- + pi^0)] < 0.25 at the 90% confidence level.Comment: Submitted to PRD Rapid Communication

    Measurement of the CP Violation Parameter sin(2phi_1) in B^0_d Meson Decays

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    We present a measurement of the Standard Model CP violation parameter sin(2phi_1) based on a 10.5 fb^{-1} data sample collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric e+e- collider. One neutral B meson is reconstructed in the J/psi K_S, psi(2S) K_S, chi_{c1} K_S, eta_c K_S, J/psi K_L or J/psi pi^0 CP-eigenstate decay channel and the flavor of the accompanying B meson is identified from its charged particle decay products. From the asymmetry in the distribution of the time interval between the two B-meson decay points, we determine sin(2phi_1) = 0.58 +0.32-0.34 (stat) +0.09-0.10 (syst).Comment: LaTex, 13 pages, 3 figures, submitted to P.R.

    Measurement of B0d - B0d-bar mixing rate from the time evolution of dilepton events at the Upsilon(4S)

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    We report a determination of the B0d - B0d-bar mixing parameter Delta-m_d based on the time evolution of dilepton yields in Upsilon(4S) decays. The measurement is based on a 5.9 /fb data sample collected by the Belle detector at KEKB. The proper-time difference distributions for same-sign and opposite-sign dilepton events are simultaneously fitted to an expression containing Delta-m_d as a free parameter. Using both muons and electrons, we obtain Delta-m_d = 0.463 +- 0.008(stat.) +- 0.016(sys.) ps^{-1} This is the first determination of Delta-m_d from time evolution measurements at the Upsilon(4S). We also place limits on possible CPT violations.Comment: 12 pages, 2 figure

    Phase transition in spin systems with various types of fluctuations

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    Various types ordering processes in systems with large fluctuation are overviewed. Generally, the so-called order–disorder phase transition takes place in competition between the interaction causing the system be ordered and the entropy causing a random disturbance. Nature of the phase transition strongly depends on the type of fluctuation which is determined by the structure of the order parameter of the system. As to the critical property of phase transitions, the concept “universality of the critical phenomena” is well established. However, we still find variety of features of ordering processes. In this article, we study effects of various mechanisms which bring large fluctuation in the system, e.g., continuous symmetry of the spin in low dimensions, contradictions among interactions (frustration), randomness of the lattice, quantum fluctuations, and a long range interaction in off-lattice systems

    Production of Prompt Charmonia in e+ee^+e^- Annihilation at s10.6\sqrt{s}\approx 10.6 GeV

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    The production of prompt J/ψJ/\psi, ψ(2S)\psi(2S), χc1\chi_{c1} and χc2\chi_{c2} is studied using a 32.4fb132.4 fb^{-1} data sample collected with the Belle detector at the Υ(4S)\Upsilon(4S) and 60 MeV below the resonance. The yield of prompt J/ψJ/\psi mesons in the Υ(4S)\Upsilon(4S) sample is compatible with that of continuum production; we set an upper limit B(Υ(4S)J/ψX)<1.9×104{\cal B}(\Upsilon(4S) \to J/\psi X) < 1.9 \times 10^{-4} at the 95% confidence level, and find σ(e+eJ/ψX)=1.47±0.10±0.13\sigma(e^{+}e^{-} \to J/\psi X)=1.47\pm 0.10 \pm 0.13 pb. The cross-sections for prompt ψ(2S)\psi(2S) and direct J/ψJ/\psi are measured. The J/ψJ/\psi momentum spectrum, production angle distribution and polarization are studied.Comment: submitted to Phys. Rev. Let
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