3,895 research outputs found

    Nutritional and health status primary schoolchildren in rural Uganda

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    Poor nutrition and health can affect children’s education. The nutritional status of school children (9-15 years) was assessed in Kumi district, Eastern Uganda in 2006-2007. Selection of schools was done using modified cluster sampling involving 34 schools (n= 645). Assessments for nutritional status were done anthropometrically (height and weight), biochemically (iron, n=145; iodine, n=87; and vitamin A, n=145) and assessment for health status was done following the formal ether concentration technique for examination for intestinal helminths (n=189) and a quick malaria (n=119) test for malaria parasites. Prevalence rates for stunting, underweight and thinness were 8.7% (95CI 6.7-11.1); 13.0% (95CI 10.6-15.8); and 10.1% (95CI 7.9-12.6), respectively of which males and the older age group of children were more affected. Prevalence rates for iodine deficiency, anaemia, iron deficiency and vitamin A deficiency (VAD) were 3.4% (95CI 0.9-9.1); 24.1% (95CI 17.7-31.6); 82.1% (95CI 75.2-87.7); and 30.3% (95CI 23.3- 38.2), respectively. Anaemia (measured as haemoglobin status), iron deficiency (measured as serum Ferritin) and VAD (measured as serum retinol) were higher among females (26.3%, 95CI 17.5-36.7; 83.8%, 95CI 74.4-90.7; 33.8%, 95CI 24.0-44.6) compared to males (21.5%, 95CI 12.8-32.8; 80%, 95CI 69.0-88.4; 26.2%, 95CI 16.6-37.8). Geohelminth (S.mansoni & N.americanus) and malaria parasitemia were 4.8% and 46.2%, respectively. Prevalence rates for stunting, iodine deficiency and geohelminth infections were low. The high prevalence rates of wasting/thinness, underweight, iron and vitamin A deficiencies show these as significant public health problems among school children in Kumi district. There is a need to focus attention on nutritional and health conditions of school children to improve their conditions. Much can be done to prevent malaria infection by promoting the use of Insecticide Treated Nets and chemoprophylaxis. The biennial dosage with albendazole for deworming, and universal use of iodized salt in Uganda are success stories that should continue; iron deficiency anaemia can be controlled through nutrition education, provision of nutritious school meals coupled with control of malaria and deworming. Since many children attend school, such services if delivered through school systems would assist those school children who most need them

    Intramolecular thiomaleimide [2+2] photocycloadditions: stereoselective control for disulfide stapling and observation of excited state intermediates by transient absorption spectroscopy

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    Thiomaleimides undergo efficient intermolecular [2 + 2] photocycloaddition reactions and offer applications from photochemical peptide stapling to polymer crosslinking; however, the reactions are limited to the formation of the exo head-to-head isomers. Herein, we present an intramolecular variation which completely reverses the stereochemical outcome of this photoreaction, quantitatively generating endo adducts which minimise the structural disturbance of the disulfide staple and afford a 10-fold increase in quantum yield. We demonstrate the application of this reaction on a protein scaffold, using light to confer thiol stability to an antibody fragment conjugate. To understand more about this intriguing class of [2 + 2] photocycloadditions, we have used transient absorption spectroscopy (electronic and vibrational) to study the excited states involved. The initially formed S2 (π1π*) excited state is observed to decay to the S1 (n1π*) state before intersystem crossing to a triplet state. An accelerated intramolecular C–C bond formation provides evidence to explain the increased efficiency of the reaction, and the impact of the various excited states on the carbonyl vibrational modes is discussed

    The effect of the annealing temperature on the local distortion of La0.67_{0.67}Ca0.33_{0.33}MnO3_3 thin films

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    Mn KK-edge fluorescence data are presented for thin film samples (3000~\AA) of Colossal Magnetoresistive (CMR) La0.67_{0.67}Ca0.33_{0.33}MnO3_3: as-deposited, and post-annealed at 1000 K and 1200 K. The local distortion is analyzed in terms of three contributions: static, phonon, and an extra, temperature-dependent, polaron term. The polaron distortion is very small for the as-deposited sample and increases with the annealing temperature. In contrast, the static distortion in the samples decreases with the annealing temperature. Although the local structure of the as-deposited sample shows very little temperature dependence, the change in resistivity with temperature is the largest of these three thin film samples. The as-deposited sample also has the highest magnetoresistance (MR), which indicates some other mechanism may also contribute to the transport properties of CMR samples. We also discuss the relationship between local distortion and the magnetization of the sample.Comment: 11 pages of Preprint format, 8 figures in one tar fil

    Gallbladder agenesis diagnosed intra-operatively: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Agenesis of the gallbladder is a rare congenital anomaly occurring in 13 to 65 people of a population of 100,000. The rarity of the condition, combined with clinical and radiologic features that are indistinguishable from those of more common biliary conditions, means that it is rarely diagnosed preoperatively, and patients undergo unnecessary operative intervention.</p> <p>Case presentation</p> <p>This case report describes the case of a 79-year-old symptomatic Caucasian man who underwent laparoscopic cholecystectomy for suspected choledocholithiasis despite imaging studies raising suspicion of gallbladder agenesis. Intra-operatively, the diagnosis of gallbladder agenesis and associated common bile duct stones was made.</p> <p>Conclusion</p> <p>The preoperative diagnosis of this rare condition is difficult to make. However, with advances in biliary tract imaging and with heightened awareness of this anomaly, fewer patients will need to undergo unnecessary operative intervention. The authors review the different imaging modalities available to help diagnose this condition and highlight the importance of being aware of this rare anomaly to avoid an operation that carries a high risk of iatrogenic injury.</p

    Studies of the decays D^0 \rightarrow K_S^0K^-\pi^+ and D^0 \rightarrow K_S^0K^+\pi^-

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    The first measurements of the coherence factor R_{K_S^0K\pi} and the average strong--phase difference \delta^{K_S^0K\pi} in D^0 \to K_S^0 K^\mp\pi^\pm decays are reported. These parameters can be used to improve the determination of the unitary triangle angle \gamma\ in B^- \rightarrow D~K−\widetilde{D}K^- decays, where D~\widetilde{D} is either a D^0 or a D^0-bar meson decaying to the same final state, and also in studies of charm mixing. The measurements of the coherence factor and strong-phase difference are made using quantum-correlated, fully-reconstructed D^0D^0-bar pairs produced in e^+e^- collisions at the \psi(3770) resonance. The measured values are R_{K_S^0K\pi} = 0.70 \pm 0.08 and \delta^{K_S^0K\pi} = (0.1 \pm 15.7)∘^\circ for an unrestricted kinematic region and R_{K*K} = 0.94 \pm 0.12 and \delta^{K*K} = (-16.6 \pm 18.4)∘^\circ for a region where the combined K_S^0 \pi^\pm invariant mass is within 100 MeV/c^2 of the K^{*}(892)^\pm mass. These results indicate a significant level of coherence in the decay. In addition, isobar models are presented for the two decays, which show the dominance of the K^*(892)^\pm resonance. The branching ratio {B}(D^0 \rightarrow K_S^0K^+\pi^-)/{B}(D^0 \rightarrow K_S^0K^-\pi^+) is determined to be 0.592 \pm 0.044 (stat.) \pm 0.018 (syst.), which is more precise than previous measurements.Comment: 38 pages. Version 3 updated to include the erratum information. Errors corrected in Eqs (25), (26), 28). Fit results updated accordingly, and external inputs updated to latest best known values. Typo corrected in Eq(3)- no other consequence

    Efficient and accurate P-value computation for Position Weight Matrices

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    <p>Abstract</p> <p>Background</p> <p>Position Weight Matrices (PWMs) are probabilistic representations of signals in sequences. They are widely used to model approximate patterns in DNA or in protein sequences. The usage of PWMs needs as a prerequisite to knowing the statistical significance of a word according to its score. This is done by defining the P-value of a score, which is the probability that the background model can achieve a score larger than or equal to the observed value. This gives rise to the following problem: Given a P-value, find the corresponding score threshold. Existing methods rely on dynamic programming or probability generating functions. For many examples of PWMs, they fail to give accurate results in a reasonable amount of time.</p> <p>Results</p> <p>The contribution of this paper is two fold. First, we study the theoretical complexity of the problem, and we prove that it is NP-hard. Then, we describe a novel algorithm that solves the P-value problem efficiently. The main idea is to use a series of discretized score distributions that improves the final result step by step until some convergence criterion is met. Moreover, the algorithm is capable of calculating the exact P-value without any error, even for matrices with non-integer coefficient values. The same approach is also used to devise an accurate algorithm for the reverse problem: finding the P-value for a given score. Both methods are implemented in a software called TFM-PVALUE, that is freely available.</p> <p>Conclusion</p> <p>We have tested TFM-PVALUE on a large set of PWMs representing transcription factor binding sites. Experimental results show that it achieves better performance in terms of computational time and precision than existing tools.</p

    Measurement of proton electromagnetic form factors in e+e−→ppˉe^+e^- \to p\bar{p} in the energy region 2.00-3.08 GeV

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    The process of e+e−→ppˉe^+e^- \rightarrow p\bar{p} is studied at 22 center-of-mass energy points (s\sqrt{s}) from 2.00 to 3.08 GeV, exploiting 688.5~pb−1^{-1} of data collected with the BESIII detector operating at the BEPCII collider. The Born cross section~(σppˉ\sigma_{p\bar{p}}) of e+e−→ppˉe^+e^- \rightarrow p\bar{p} is measured with the energy-scan technique and it is found to be consistent with previously published data, but with much improved accuracy. In addition, the electromagnetic form-factor ratio (∣GE/GM∣|G_{E}/G_{M}|) and the value of the effective (∣Geff∣|G_{\rm{eff}}|), electric (∣GE∣|G_E|) and magnetic (∣GM∣|G_M|) form factors are measured by studying the helicity angle of the proton at 16 center-of-mass energy points. ∣GE/GM∣|G_{E}/G_{M}| and ∣GM∣|G_M| are determined with high accuracy, providing uncertainties comparable to data in the space-like region, and ∣GE∣|G_E| is measured for the first time. We reach unprecedented accuracy, and precision results in the time-like region provide information to improve our understanding of the proton inner structure and to test theoretical models which depend on non-perturbative Quantum Chromodynamics

    Search for the decay J/ψ→γ+invisibleJ/\psi\to\gamma + \rm {invisible}

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    We search for J/ψJ/\psi radiative decays into a weakly interacting neutral particle, namely an invisible particle, using the J/ψJ/\psi produced through the process ψ(3686)→π+π−J/ψ\psi(3686)\to\pi^+\pi^-J/\psi in a data sample of (448.1±2.9)×106(448.1\pm2.9)\times 10^6 ψ(3686)\psi(3686) decays collected by the BESIII detector at BEPCII. No significant signal is observed. Using a modified frequentist method, upper limits on the branching fractions are set under different assumptions of invisible particle masses up to 1.2  GeV/c2\mathrm{\ Ge\kern -0.1em V}/c^2. The upper limit corresponding to an invisible particle with zero mass is 7.0×10−7\times 10^{-7} at the 90\% confidence level

    Precise Measurements of Branching Fractions for Ds+D_s^+ Meson Decays to Two Pseudoscalar Mesons

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    We measure the branching fractions for seven Ds+D_{s}^{+} two-body decays to pseudo-scalar mesons, by analyzing data collected at s=4.178∼4.226\sqrt{s}=4.178\sim4.226 GeV with the BESIII detector at the BEPCII collider. The branching fractions are determined to be B(Ds+→K+η′)=(2.68±0.17±0.17±0.08)×10−3\mathcal{B}(D_s^+\to K^+\eta^{\prime})=(2.68\pm0.17\pm0.17\pm0.08)\times10^{-3}, B(Ds+→η′π+)=(37.8±0.4±2.1±1.2)×10−3\mathcal{B}(D_s^+\to\eta^{\prime}\pi^+)=(37.8\pm0.4\pm2.1\pm1.2)\times10^{-3}, B(Ds+→K+η)=(1.62±0.10±0.03±0.05)×10−3\mathcal{B}(D_s^+\to K^+\eta)=(1.62\pm0.10\pm0.03\pm0.05)\times10^{-3}, B(Ds+→ηπ+)=(17.41±0.18±0.27±0.54)×10−3\mathcal{B}(D_s^+\to\eta\pi^+)=(17.41\pm0.18\pm0.27\pm0.54)\times10^{-3}, B(Ds+→K+KS0)=(15.02±0.10±0.27±0.47)×10−3\mathcal{B}(D_s^+\to K^+K_S^0)=(15.02\pm0.10\pm0.27\pm0.47)\times10^{-3}, B(Ds+→KS0π+)=(1.109±0.034±0.023±0.035)×10−3\mathcal{B}(D_s^+\to K_S^0\pi^+)=(1.109\pm0.034\pm0.023\pm0.035)\times10^{-3}, B(Ds+→K+π0)=(0.748±0.049±0.018±0.023)×10−3\mathcal{B}(D_s^+\to K^+\pi^0)=(0.748\pm0.049\pm0.018\pm0.023)\times10^{-3}, where the first uncertainties are statistical, the second are systematic, and the third are from external input branching fraction of the normalization mode Ds+→K+K−π+D_s^+\to K^+K^-\pi^+. Precision of our measurements is significantly improved compared with that of the current world average values

    Simplified novel muraymycin analogues ; using a serine template strategy for linking key pharmacophores

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    The present status of antibiotic research requires the urgent invention of novel agents that act on multidrug-resistant bacteria. The World Health Organization has classified antibiotic-resistant bacteria into critical, high and medium priority according to the urgency of need for new antibiotics. Naturally occurring uridine-derived "nucleoside antibiotics" have shown promising activity against numerous priority resistant organisms by inhibiting the transmembrane protein MraY (translocase I), which is yet to be explored in a clinical context. The catalytic activity of MraY is an essential process for bacterial cell viability and growth including that of priority organisms. Muraymycins are one subclass of naturally occurring MraY inhibitors. Despite having potent antibiotic properties, the structural complexity of muraymycins advocates for simplified analogues as potential lead structures. Herein, we report a systematic structure-activity relationship (SAR) study of serine template-linked, simplified muraymycin-type analogues. This preliminary SAR lead study of serine template analogues successfully revealed that the complex structure of naturally occurring muraymycins could be easily simplified to afford bioactive scaffolds against resistant priority organisms. This study will pave the way for the development of novel antibacterial lead compounds based on a simplified serine template. [Abstract copyright: © 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
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