710 research outputs found

    Informed consent comprehension in African research settings

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    ObjectivePrevious reviews on participants' comprehension of informed consent information have focused on developed countries. Experience has shown that ethical standards developed on Western values may not be appropriate for African settings where research concepts are unfamiliar. We undertook this review to describe how informed consent comprehension is defined and measured in African research settings.MethodsWe conducted a comprehensive search involving five electronic databases: Medline, Embase, Global Health, EthxWeb and Bioethics Literature Database (BELIT). We also examined African Index Medicus and Google Scholar for relevant publications on informed consent comprehension in clinical studies conducted in sub-Saharan Africa. 29 studies satisfied the inclusion criteria; meta-analysis was possible in 21 studies. We further conducted a direct comparison of participants' comprehension on domains of informed consent in all eligible studies.ResultsComprehension of key concepts of informed consent varies considerably from country to country and depends on the nature and complexity of the study. Meta-analysis showed that 47% of a total of 1633 participants across four studies demonstrated comprehension about randomisation (95% CI 13.9–80.9%). Similarly, 48% of 3946 participants in six studies had understanding about placebo (95% CI 19.0–77.5%), while only 30% of 753 participants in five studies understood the concept of therapeutic misconception (95% CI 4.6–66.7%). Measurement tools for informed consent comprehension were developed with little or no validation. Assessment of comprehension was carried out at variable times after disclosure of study information. No uniform definition of informed consent comprehension exists to form the basis for development of an appropriate tool to measure comprehension in African participants.ConclusionsComprehension of key concepts of informed consent is poor among study participants across Africa. There is a vital need to develop a uniform definition for informed consent comprehension in low literacy research settings in Africa. This will be an essential step towards developing appropriate tools that can adequately measure informed consent comprehension. This may consequently suggest adequate measures to improve the informed consent procedure.ObjectifLes normes éthiques élaborées selon les valeurs occidentales ne sont peut-être pas appropriées au contexte africain où les concepts de recherche ne sont pas familiers. Cette revue décrit comment la compréhension du consentement éclairé est définie et mesurée dans les cadres de recherche africains.MéthodesDes recherches ont été effectuées sur Medline, Embase, Global Health, EthxWeb, base de données de la Bioéthique Littérature, Index Medicus African et Google Scholar pour des publications pertinentes sur la compréhension du consentement éclairé dans les études cliniques menées en Afrique sub-saharienne. 29 études répondaient aux critères d'inclusion; une méta-analyse a été possible pour 21 études. La compréhension des participants sur les domaines du consentement éclairé dans toutes les études admissibles a été comparée directement.RésultatsLa compréhension des concepts clés du consentement éclairé varie considérablement selon les pays et dépend de la nature et de la complexité de l’étude. La méta-analyse a montré que 47% des participants ont compris la randomisation (IC95%: 13,9 - 80,9%), 48% ont compris le placebo (IC95%: 19,0 - 77,5%), 30% ont compris le concept de méprise thérapeutique (IC95%: 4,6 - 66,7%). Les outils de mesure de la compréhension du consentement éclairé étaient développés avec peu ou pas de validation.ConclusionsLa compréhension des concepts clés du consentement éclairé est faible en Afrique. Il y a une nécessité vitale d’élaborer une définition uniforme pour la compréhension du consentement éclairé dans les cadres de recherche avec un faible niveau d'alphabétisation en Afrique.ObjetivoLos estándares éticos desarrollados basándose en valores occidentales podrían no ser apropiados para emplazamientos Africanos en donde los conceptos de investigación no son familiares. En esta revisión se describe como la comprensión del consentimiento informado se define y mide en un centro de investigación Africano.MétodosSe buscaron publicaciones relevantes sobre la comprensión del consentimiento informado en estudios clínicos en África subsahariana en Medline, Embase, Global Health, EthxWeb, Bioethics Literature Database, African Index Medicus y Google Scholar. 29 estudios satisfacían los criterios de inclusión y el metaanálisis era posible para 21. La comprensión del consentimiento informado por parte de los participantes se comparó directamente en todos los estudios elegibles.ResultadosLa comprensión de conceptos claves del consentimiento informado varió de forma considerable entre países, y dependía de la naturaleza y de la complejidad del estudio. El meta-análisis mostró que un 47% entendía la aleatorización (IC 95% 13.9-80.9%); un 48% entendía el placebo (IC 95% 19.0-77.5%); y un 30% entendió el concepto terapéutico errado (IC 95% 4.6-66.7%). Las herramientas para medir la comprensión del consentimiento informado se desarrollaron con poca o ninguna validación.ConclusionesEn África, la comprensión de conceptos claves del consentimiento informado es pobre. Existe una necesidad vital de desarrollar una definición uniforme para la comprensión del consentimiento informado en lugares con bajos niveles de alfabetización en África

    On Leveraging Tests to Infer Nullable Annotations

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    Issues related to the dereferencing of null pointers are a pervasive and widely studied problem, and numerous static analyses have been proposed for this purpose. These are typically based on dataflow analysis, and take advantage of annotations indicating whether a type is nullable or not. The presence of such annotations can significantly improve the accuracy of null checkers. However, most code found in the wild is not annotated, and tools must fall back on default assumptions, leading to both false positives and false negatives. Manually annotating code is a laborious task and requires deep knowledge of how a program interacts with clients and components. We propose to infer nullable annotations from an analysis of existing test cases. For this purpose, we execute instrumented tests and capture nullable API interactions. Those recorded interactions are then refined (santitised and propagated) in order to improve their precision and recall. We evaluate our approach on seven projects from the spring ecosystems and two google projects which have been extensively manually annotated with thousands of @Nullable annotations. We find that our approach has a high precision, and can find around half of the existing @Nullable annotations. This suggests that the method proposed is useful to mechanise a significant part of the very labour-intensive annotation task

    Parasystole in a Mahaim Accessory Pathway

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    AbstractAutomaticity has been described in Mahaim pathways, both spontaneously and during radiofrequency ablation. We describe an unusual case of automatic rhythm from a Mahaim pathway presenting as parasystole. The parasystolic beats were also found to initiate tachycardia, resulting in initial presentation with incessant tachycardia and tachycardia induced cardiomyopathy

    Evaporation-Driven Micromixing in Sessile Droplets for Miniaturized Absorbance-Based Colorimetry

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    We demonstrate the use of an evaporating, sessile droplet on a nonwetting substrate as a miniature micromixing device to conduct sample−dye reactions for absorbance-based colorimetry. The nonwetting substrate supports buoyancy-induced mixing inside the droplet for rapid completion of the measurement. The Bradford assay is used as a proof of concept, where a protein-containing sample is reacted with a reagent dye to measure the protein concentration. Viability of absorbance measurement through the droplet is first established using droplets in which the reactants are mixed prior to their deposition onto the substrate. In a second set of experiments involving in situ mixing, the reagent is directly added to a sessile droplet of the protein-containing sample, allowing the reactants to mix while the absorbance is being measured. Interplay between buoyancyinduced mixing, protein−reagent reaction, and protein adsorption onto the substrate leads to a complex temporal absorbance measurement signal. Videos corresponding to the signal data show that each of these mechanisms dominates during different phases of droplet evolution, causing a signal pattern containing peaks and valleys having a strong monotonic trend with the protein concentration. Overall, the second absorbance peak at which the reaction nears completion is the most sensitive to sample concentration. Heating of the substrate is demonstrated to dramatically speed up the mixing process. These protein concentration measurements, obtained with a simpler system and low reactant volumes, demonstrate that this droplet micromixing concept is a viable alternative to microtiter plates for colorimetric applications

    Regularized Neural User Model for Goal-Oriented Spoken Dialogue Systems

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    User simulation is widely used to generate artificial dialogues in order to train statistical spoken dialogue systems and perform evaluations. This paper presents a neural network approach for user modeling that exploits an encoder-decoder bidirectional architecture with a regularization layer for each dialogue act. In order to minimize the impact of data sparsity, the dialogue act space is compressed according to the user goal. Experiments on the Dialogue State Tracking Challenge 2 (DSTC2) dataset provide significant results at dialogue act and slot level predictions, outperforming previous neural user modeling approaches in terms of F1 score.Spanish Minister of Science under grants TIN2014-54288-C4-4-R and TIN2017-85854-C4-3-R and by the EU H2020 EMPATHIC project grant number 769872

    Haemoglobin and haematocrit: is the threefold conversion valid for assessing anaemia in malaria-endemic settings?

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    BACKGROUND: Anaemic status is determined by haemoglobin using the HemoCue system or haematocrit measurements, and a threefold conversion is commonly used to equate the two measures (haemoglobin = haematocrit/3). The validity of this conversion in malaria endemic settings was assessed. METHODS: Concurrent measures of haemoglobin and centrifuged haematocrit in children aged 6-59 months were compared by modelling the difference between the two measures against their average. A random effects linear regression of the difference of the measures on their average was used to describe the line of best agreement and 95% limits of agreement for these two measures over a range of values after adjusting for statistically significant covariates. RESULTS: There was a consistent bias between the two measures, with haemoglobin less than haematocrit/3 in 87% (899/1,030) of observations. This difference was non-uniform, decreasing with the average measure, i.e. less difference at higher haemoglobin and haematocrit values. In these studies, use of haematocrit would have underestimated the prevalence of anaemia by misclassifying 10% (89/920) of individuals with haemoglobin < 11 g/dl, 66% (252/380) of individuals with haemoglobin < 8 g/dl and 100% (23/23) of individuals with haemoglobin < 5 g/dl. The mean difference between the measures was greater in males than females, increased with age between 6-59 months, and was greater in the wet than dry season suggesting that the relationship between haemoglobin and haematocrit may be modified by exposure to malaria. CONCLUSION: The regression model indicated that the standard threefold conversion from haematocrit to haemoglobin underestimates the prevalence of haemoglobin < 11 g/dl in children under five years of age in malaria endemic settings. This bias was more acute for more severe anaemia defined by haemoglobin < 8 g/dl and haemoglobin < 5 g/dl. This has important implications for the comparability of studies using these different measures. Direct determination of haemoglobin should be the measurement of choice for assessing anaemia outcomes in malaria intervention trials and surveys

    Low Temperature Measurements by Infrared Spectroscopy in CoFe2_2O4_4 Ceramic

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    In this paper results of new far-infrared and middle-infrared measurements (wavenumber range of 4000cm-1 - 100cm-1) in the range of the temperature from 300K to 8K of the CoFe2O4 ceramic are presented. The bands positions and their shapes are the same in the wide temperature range. The quality of the sample was investigated by X-ray, EDS and EPMA studies. The CoFe2O4 reveals the cubic structure (Fd-3m) in the temperature range from 85K to 360 K without any traces of distortion. On the current level of knowledge the polycrystalline CoFe2O4 does not exhibit phase transition in the temperature range from 8 K to 300 K.Comment: 10 pages, 6 figure
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