6 research outputs found

    Geochemistry of Pegmatites associated with the cape coast granite complex in the Egyaa and Akim Oda areas of southern Ghana

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    The Cape Coast granite complex, which is associated with  metasedimentary rocks of the Birirmian in Ghana, is characterised by various minor intrusions that include pegmatites. The pegmatites, which are feldspar-rich, occur within, and at the margins of the granite batholiths and the surrounding schists. The major and trace element compositions of the pegmatites sampled from Egyaa and Akim Oda areas have been determined. The data indicates that the pegmatites from these areas have granitic compositions. The rocks are medium-K to high-K, calc-alkaline, S-type granitoids that are peraluminous and magnesian. Lower values of molar CaO/ (MgO + FeO <sub>tot</tot>) coupled with higher values of molar Al<sub>2</sub>O<sub>3</sub>/(MgO + FeO<sub>tot</sup>) suggest their derivation from partial melting from metapelitic sources, with the Birimian metasedimentary rocks being the likely source material. The rocks are depleted in Rb, Ba, Nb, Ce and Ti but rich in U, K, La, Hf and Y relative to primitive mantle. The data suggest that the pegmatites from these areas are late orogenic, and were emplaced at upper to middle crustal levels in a volcanic arc geotectonic environment

    Evaluation of pragmatic oxygenation measurement as a proxy for Covid-19 severity

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    Choosing optimal outcome measures maximizes statistical power, accelerates discovery and improves reliability in early-phase trials. We devised and evaluated a modification to a pragmatic measure of oxygenation function, the [Formula: see text] ratio. Because of the ceiling effect in oxyhaemoglobin saturation, [Formula: see text] ratio ceases to reflect pulmonary oxygenation function at high [Formula: see text] values. We found that the correlation of [Formula: see text] with the reference standard ([Formula: see text]/[Formula: see text] ratio) improves substantially when excluding [Formula: see text] and refer to this measure as [Formula: see text]. Using observational data from 39,765 hospitalised COVID-19 patients, we demonstrate that [Formula: see text] is predictive of mortality, and compare the sample sizes required for trials using four different outcome measures. We show that a significant difference in outcome could be detected with the smallest sample size using [Formula: see text]. We demonstrate that [Formula: see text] is an effective intermediate outcome measure in COVID-19. It is a non-invasive measurement, representative of disease severity and provides greater statistical power

    Evaluation of pragmatic oxygenation measurement as a proxy for Covid-19 severity

    Get PDF
    Choosing optimal outcome measures maximizes statistical power, accelerates discovery and improves reliability in early-phase trials. We devised and evaluated a modification to a pragmatic measure of oxygenation function, the [Formula: see text] ratio. Because of the ceiling effect in oxyhaemoglobin saturation, [Formula: see text] ratio ceases to reflect pulmonary oxygenation function at high [Formula: see text] values. We found that the correlation of [Formula: see text] with the reference standard ([Formula: see text]/[Formula: see text] ratio) improves substantially when excluding [Formula: see text] and refer to this measure as [Formula: see text]. Using observational data from 39,765 hospitalised COVID-19 patients, we demonstrate that [Formula: see text] is predictive of mortality, and compare the sample sizes required for trials using four different outcome measures. We show that a significant difference in outcome could be detected with the smallest sample size using [Formula: see text]. We demonstrate that [Formula: see text] is an effective intermediate outcome measure in COVID-19. It is a non-invasive measurement, representative of disease severity and provides greater statistical power

    Measurement of the branching fraction for the decay BK(892)+B \to K^{\ast}(892)\ell^+\ell^- at Belle II

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    We report a measurement of the branching fraction of BK(892)+B \to K^{\ast}(892)\ell^+\ell^- decays, where +=μ+μ\ell^+\ell^- = \mu^+\mu^- or e+ee^+e^-, using electron-positron collisions recorded at an energy at or near the Υ(4S)\Upsilon(4S) mass and corresponding to an integrated luminosity of 189189 fb1^{-1}. The data was collected during 2019--2021 by the Belle II experiment at the SuperKEKB e+ee^{+}e^{-} asymmetric-energy collider. We reconstruct K(892)K^{\ast}(892) candidates in the K+πK^+\pi^-, KS0π+K_{S}^{0}\pi^+, and K+π0K^+\pi^0 final states. The signal yields with statistical uncertainties are 22±622\pm 6, 18±618 \pm 6, and 38±938 \pm 9 for the decays BK(892)μ+μB \to K^{\ast}(892)\mu^+\mu^-, BK(892)e+eB \to K^{\ast}(892)e^+e^-, and BK(892)+B \to K^{\ast}(892)\ell^+\ell^-, respectively. We measure the branching fractions of these decays for the entire range of the dilepton mass, excluding the very low mass region to suppress the BK(892)γ(e+e)B \to K^{\ast}(892)\gamma(\to e^+e^-) background and regions compatible with decays of charmonium resonances, to be \begin{equation} {\cal B}(B \to K^{\ast}(892)\mu^+\mu^-) = (1.19 \pm 0.31 ^{+0.08}_{-0.07}) \times 10^{-6}, {\cal B}(B \to K^{\ast}(892)e^+e^-) = (1.42 \pm 0.48 \pm 0.09)\times 10^{-6}, {\cal B}(B \to K^{\ast}(892)\ell^+\ell^-) = (1.25 \pm 0.30 ^{+0.08}_{-0.07}) \times 10^{-6}, \end{equation} where the first and second uncertainties are statistical and systematic, respectively. These results, limited by sample size, are the first measurements of BK(892)+B \to K^{\ast}(892)\ell^+\ell^- branching fractions from the Belle II experiment

    Trace metals quality of some herbal medicines sold in Accra, Ghana

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    Abstract Ten brands of herbal medicines were selected on the market for the analysis of trace metals quality using the Atomic Absorption Spectrometer. The results were reported as the mean concentration of three representative samples for each of the ten brands. The respective percentage incidence of the trace metals analyzed were; Fe (20%), Zn (80%), Cu (20%), Cd (40%); Al (100%) and Pb (100%). The range of the mean concentrations measured for all the brands were; Fe (<0.006-3.298 mg/L), Zn (<0.001-0.091 mg/L), Cu (<0.003-0.009 mg/L), Cd (<0.002-0.003), Al (0.278-0.533 mg/L) and Pb (0.0056-0.085 mg/L). The mean concentrations of the trace metals measured were generally low and below stipulated national limits as per WHO (2007). A hierarchical cluster analysis indicated two clusters; cluster 1 (CA1) loading Zn, Al and Fe whilst Cluster 2 (CA2) loaded Cd and Pb. The presence of these trace metals may be the result of accidental contamination during manufacture, for instance, from grinding weights or lead-releasing containers or other manufacturing utensils and contamination from polluted soils on which the herbs were harvested. Some brands of the herbal medicines sampled do not have the code in Food and Drugs Board of Ghana. Hence a routine analysis of these herbal medicines must be carried out to ensure the safety of the consuming populace

    Adaptation of the Wound Healing Questionnaire universal-reporter outcome measure for use in global surgery trials (TALON-1 study): mixed-methods study and Rasch analysis

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    BackgroundThe Bluebelle Wound Healing Questionnaire (WHQ) is a universal-reporter outcome measure developed in the UK for remote detection of surgical-site infection after abdominal surgery. This study aimed to explore cross-cultural equivalence, acceptability, and content validity of the WHQ for use across low- and middle-income countries, and to make recommendations for its adaptation.MethodsThis was a mixed-methods study within a trial (SWAT) embedded in an international randomized trial, conducted according to best practice guidelines, and co-produced with community and patient partners (TALON-1). Structured interviews and focus groups were used to gather data regarding cross-cultural, cross-contextual equivalence of the individual items and scale, and conduct a translatability assessment. Translation was completed into five languages in accordance with Mapi recommendations. Next, data from a prospective cohort (SWAT) were interpreted using Rasch analysis to explore scaling and measurement properties of the WHQ. Finally, qualitative and quantitative data were triangulated using a modified, exploratory, instrumental design model.ResultsIn the qualitative phase, 10 structured interviews and six focus groups took place with a total of 47 investigators across six countries. Themes related to comprehension, response mapping, retrieval, and judgement were identified with rich cross-cultural insights. In the quantitative phase, an exploratory Rasch model was fitted to data from 537 patients (369 excluding extremes). Owing to the number of extreme (floor) values, the overall level of power was low. The single WHQ scale satisfied tests of unidimensionality, indicating validity of the ordinal total WHQ score. There was significant overall model misfit of five items (5, 9, 14, 15, 16) and local dependency in 11 item pairs. The person separation index was estimated as 0.48 suggesting weak discrimination between classes, whereas Cronbach's α was high at 0.86. Triangulation of qualitative data with the Rasch analysis supported recommendations for cross-cultural adaptation of the WHQ items 1 (redness), 3 (clear fluid), 7 (deep wound opening), 10 (pain), 11 (fever), 15 (antibiotics), 16 (debridement), 18 (drainage), and 19 (reoperation). Changes to three item response categories (1, not at all; 2, a little; 3, a lot) were adopted for symptom items 1 to 10, and two categories (0, no; 1, yes) for item 11 (fever).ConclusionThis study made recommendations for cross-cultural adaptation of the WHQ for use in global surgical research and practice, using co-produced mixed-methods data from three continents. Translations are now available for implementation into remote wound assessment pathways
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