195 research outputs found
Malaria chemoprophylaxis recommendations for immigrants to Europe, visiting relatives and friends - a Delphi method study
BACKGROUND: Numbers of travellers visiting friends and relatives (VFRs) from Europe to malaria endemic countries are increasing and include long-term and second generation immigrants, who represent the major burden of malaria cases imported back into Europe. Most recommendations for malaria chemoprophylaxis lack a solid evidence base, and often fail to address the cultural, social and economic needs of VFRs. METHODS: European travel medicine experts, who are members of TropNetEurop, completed a sequential series of questionnaires according to the Delphi method. This technique aims at evaluating and developing a consensus through repeated iterations of questionnaires. The questionnaires in this study included questions about professional experience with VFRs, controversial issues in malaria prophylaxis, and 16 scenarios exploring indications for prescribing and choice of chemoprophylaxis. RESULTS: The experience of participants was rather diverse as was their selection of chemoprophylaxis regimen. A significant consensus was observed in only seven of 16 scenarios. The analysis revealed a wide variation in prescribing choices with preferences grouped by region of practice and increased prescribing seen in Northern Europe compared to Central Europe. CONCLUSIONS: Improving the evidence base on efficacy, adherence to chemoprophylaxis and risk of malaria and encouraging discussion among experts, using techniques such as the Delphi method, may reduce the variability in prescription in European travel clinics
Evidence of the Purely Leptonic Decay B- --> tau- nu_tau-bar
We present the first evidence of the decay B- --> tau- nu_tau-bar using 414
fb^-1 of data collected at the Upsilon(4S) resonance with the Belle detector at
the KEKB asymmetric-energy e+e- collider. Events are tagged by fully
reconstructing one of the B mesons in hadronic modes. We detect the signal with
a significance of 3.5 standard deviations including systematics, and measure
the branching fraction to be Br(B- --> tau- nu_tau-bar) = (1.79
+0.56-0.49(stat) +0.46-0.51(syst))*10^-4. This implies that f_B = 0.229
+0.036-0.031(stat) +0.034-0.037(syst) GeV and is the first direct measurement
of this quantity.Comment: 6 pages, 3 figures, to appear in Physical Review Letter
Study of J/psi to p pbar, Lambda Lambdabar and observation of eta_c to Lambda Lambdabar at Belle
We study the baryonic charmonium decays of B mesons, B+ to etac K+ and B+ to
J/psi K+, where the etac and J/psi subsequently decay into a p pbar or Lambda
Lambdabar pair. We measure the J/psi to p pbar, Lambda Lambdabar anisotropy
parameters, alpha_B = -0.60 +- 0.13 +-0.14 (p pbar), -0.44 +- 0.51 +- 0.31
(Lambda Lambdabar) and compare to results from e+e- to J/psi formation
experiments. We also report the first observation of etac to Lambda Lambdabar.
The measured branching fraction is B(etac to Lambda Lambdabar) = (0.87 +0.24
-0.21(stat) +0.09 -0.14(syst) +- 0.27 (PDG)) x 10^-3. This study is based on a
357 fb^-1 data sample recorded on the Upsilon(4S) resonance with the Belle
detector at the KEKB asymmetric-energy e+e- collider.Comment: 8 pages, two figures (4 figure files), an update of hep-ex/0509020
for journal submissio
Measurement of D0 -> pilnu (Klnu) Form Factors and Absolute Branching Fractions
Using a 282 1/fb data sample collected by the Belle experiment at the KEKB
e+e- collider, we study D0 decays to K-l+nu and pi-l+nu final states. The D0
flavor and momentum are tagged through a full reconstruction of the recoiling
charm meson and additional mesons from fragmentation. The reconstruction method
provides very good resolution in neutrino momentum and in q^2 = (p_l+p_nu)^2.
Normalizing to the total number of D0 tags, we measure the absolute branching
fractions to be B(D0 -> Klnu) =(3.45 +- 0.07stat +- 0.20syst)% and B(D0 ->
pilnu) = (0.255 +- 0.019stat +- 0.016syst)% and the semi-leptonic form factors
(within the modified pole model) f+^K(0) = 0.695 +- 0.007stat +- 0.022syst and
f+^pi(0) = 0.624 +- 0.020stat +- 0.030syst.Comment: 9 pages, 2 figures, submitted to Phys. Rev. Let
Observation of a new charmonium state in double charmonium production in e+ e- annihilation at \sqrt{s} ~ 10.6 GeV
We report the first observation of a new charmonium state at a mass of
. This state, called X(3940), is
observed in the process in the spectrum of masses
recoiling against a reconstructed . We also observe the decay of the
X(3940) into and measure the intrinsic width of this state to be
less than at the 90% C.L. These results are obtained from a data sample collected with the Belle detector near the
resonance, at the KEKB asymmetric energy collider.Comment: BELLE-CONF-051
Observation of b --> d gamma and Determination of |V_td/V_ts|
We report the observation of the flavor-changing neutral current process b
--> d gamma using a sample of 386*10^6 B meson pairs accumulated by the Belle
detector at the KEKB e+ e- collider. We measure branching fractions for the
exclusive modes B- --> rho- gamma, B0bar --> rho0 gammaand B0bar --> omega
gamma. Assuming that these three modes are related by isospin, we find Br(B -->
(rho,omega) gamma) = (1.32 +0.34-0.31(stat.) +0.10-0.09(syst.)) * 10^-6 with a
significance of 5.1 sigma. This result is used to determine the ratio of CKM
matrix elements |V_td/V_ts| to be 0.199 +0.026-0.025(exp.) +0.018-0.015(theo.).Comment: 5 pages, 2 figures, submitted to Physical Review Letter
Improved Constraints on D0-D0bar Mixing in D0 -> K+ pi- Decays from the Belle Detector
We report the results of a search for D0-D0bar mixing in D0 -> K+ pi- decays
based on 400 fb^{-1} of data accumulated by the Belle detector at KEKB. Both
assuming CP conservation and allowing for CP violation, we fit the decay-time
distribution for the mixing parameters x' and y', as well as for the parameter
R_D, the ratio of doubly-Cabibbo-suppressed decays to Cabibbo-favored decays.
The 95% confidence level region in the (x'^2,y') plane is obtained using a
frequentist method. Assuming CP conservation, we find x'^2<0.72 x 10^{-3} and
-9.9 x 10^{-3}<y'<6.8 x 10^{-3} at the 95% confidence level; these are the most
stringent constraints on the mixing parameters to date. The no-mixing point
(0,0) has a confidence level of 3.9%. Assuming no mixing, we measure
R_D=(0.377+-0.008+-0.005)%.Comment: 6 pages, 3 figures, 1 table; replaced with the version of Phys. Rev.
Let
Observation of the decay
We report the first observation of decay. These results
are obtained from a data sample that contains 449 million pairs
accumulated at the resonance with the Belle detector at the KEKB
asymmetric-energy collider. We observe a signal with a significance
of 8.1 and obtain a branching fraction of (9.5 1.7 (stat)
0.8 (syst)).Comment: 5 pages, 2 figures, submit to PRL (8 pages, 2 figures, ICHEP'06
Conference Paper
Measurement of Branching Fraction and Direct CP Asymmetry in B0-->rho0 pi0 Decays
We report a measurement of the decay B0 --> rho0 pi0, using 386 x 10^6 BB-bar
pairs collected at the Upsilon(4S) resonance with the Belle detector at the
KEKB asymmetric-energy e+e- collider. We detect 51^{+14}_{-13} signal events
with a significance of 4.2 standard deviations, including systematic
uncertainties, and measure the branching fraction to be B(B0 --> rho0 pi0) =
(3.12^{+0.88}_{-0.82} (stat) +/- 0.33 (syst) ^{+0.50}_{-0.68} (model)) x
10^{-6}. We also perform the first measurement of direct CP violating asymmetry
in this mode.Comment: 5 pages, 2 figures, accepted in Physical Review
Physiological characteristics of dysphagia following thermal burn injury
The study aim was to document the acute physiological characteristics of swallowing impairment following thermal burn injury. A series of 19 participants admitted to a specialised burn centre with thermal burn injury were identified with suspected aspiration risk by a clinical swallow examination (CSE) conducted by a speech-language pathologist and referred to the study. Once medically stable, each then underwent more detailed assessment using both a CSE and fiberoptic evaluation of swallowing (FEES). FEES confirmed six individuals (32%) had no aspiration risk and were excluded from further analyses. Of the remaining 13, CSE confirmed that two had specific oral-phase deficits due to orofacial scarring and contractures, and all 13 had generalised oromotor weakness. FEES revealed numerous pharyngeal-phase deficits, with the major findings evident in greater than 50% being impaired secretion management, laryngotracheal edema, delayed swallow initiation, impaired sensation, inadequate movement of structures within the hypopharynx and larynx, and diffuse pharyngeal residue. Penetration and/or aspiration occurred in 83% (n = 10/12) of thin fluids trials, with a lack of response to the penetration/aspiration noted in 50% (n = 6/12 penetration aspiration events) of the cases. Most events occurred post swallow. Findings support the fact that individuals with dysphagia post thermal burn present with multiple risk factors for aspiration that appear predominantly related to generalised weakness and inefficiency and further impacted by edema and sensory impairments. Generalised oromotor weakness and orofacial contractures (when present) impact oral-stage swallow function. This study has identified a range of factors that may contribute to both oral- and pharyngeal-stage dysfunction in this clinical population and has highlighted the importance of using a combination of clinical and instrumental assessments to fully understand the influence of burn injury on oral intake and swallowing
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