436 research outputs found

    Optimizing solid manure application by improving distribution

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    Improving the uniformity of manure distribution may make it a more effective substitute for commercial fertilizer and allow farmers to take proper nutrient credit for the manure. Manure-spreading equipment or application techniques may need to be modified to be more efficient

    25 years of the WHO essential medicines lists: progress and challenges.

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    The first WHO essential drugs list, published in 1977, was described as a peaceful revolution in international public health. The list helped to establish the principle that some medicines were more useful than others and that essential medicines were often inaccessible to many populations. Since then, the essential medicines list (EML) has increased in size; defining an essential medicine has moved from an experience to an evidence-based process, including criteria such as public-health relevance, efficacy, safety, and cost-effectiveness. High priced medicines such as antiretrovirals are now included. Differences exist between the WHO model EML and national EMLs since countries face varying challenges relating to costs, drug effectiveness, morbidity patterns, and rationality of prescribing. Ensuring equitable access to and rational use of essential medicines has been promoted through WHO's revised drug strategy. This approach has required an engagement by WHO on issues such as the effect of international trade agreements on access to essential medicines and research and development to ensure availability of new essential medicines

    Photorespiration: metabolic pathways and their role in stress protection

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    Photorespiration results from the oxygenase reaction catalysed by ribulose-1,5-bisphosphate carboxylase/ oxygenase. In this reaction glycollate-2-phosphate is produced and subsequently metabolized in the photorespiratory pathway to form the Calvin cycle intermediate glycerate-3-phosphate. During this metabolic process, CO2 and NH3 are produced and ATP and reducing equivalents are consumed, thus making photorespiration a wasteful process. However, precisely because of this ine¤ciency, photorespiration could serve as an energy sink preventing the overreduction of the photosynthetic electron transport chain and photoinhibition, especially under stress conditions that lead to reduced rates of photosynthetic CO2 assimilation. Furthermore, photorespiration provides metabolites for other metabolic processes, e.g. glycine for the synthesis of glutathione, which is also involved in stress protection. In this review, we describe the use of photorespiratory mutants to study the control and regulation of photorespiratory pathways. In addition, we discuss the possible role of photorespiration under stress conditions, such as drought, high salt concentrations and high light intensities encountered by alpine plants

    Control of hyperglycaemia in paediatric intensive care (CHiP): study protocol.

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    BACKGROUND: There is increasing evidence that tight blood glucose (BG) control improves outcomes in critically ill adults. Children show similar hyperglycaemic responses to surgery or critical illness. However it is not known whether tight control will benefit children given maturational differences and different disease spectrum. METHODS/DESIGN: The study is an randomised open trial with two parallel groups to assess whether, for children undergoing intensive care in the UK aged <or= 16 years who are ventilated, have an arterial line in-situ and are receiving vasoactive support following injury, major surgery or in association with critical illness in whom it is anticipated such treatment will be required to continue for at least 12 hours, tight control will increase the numbers of days alive and free of mechanical ventilation at 30 days, and lead to improvement in a range of complications associated with intensive care treatment and be cost effective. Children in the tight control group will receive insulin by intravenous infusion titrated to maintain BG between 4 and 7.0 mmol/l. Children in the control group will be treated according to a standard current approach to BG management. Children will be followed up to determine vital status and healthcare resources usage between discharge and 12 months post-randomisation. Information regarding overall health status, global neurological outcome, attention and behavioural status will be sought from a subgroup with traumatic brain injury (TBI). A difference of 2 days in the number of ventilator-free days within the first 30 days post-randomisation is considered clinically important. Conservatively assuming a standard deviation of a week across both trial arms, a type I error of 1% (2-sided test), and allowing for non-compliance, a total sample size of 1000 patients would have 90% power to detect this difference. To detect effect differences between cardiac and non-cardiac patients, a target sample size of 1500 is required. An economic evaluation will assess whether the costs of achieving tight BG control are justified by subsequent reductions in hospitalisation costs. DISCUSSION: The relevance of tight glycaemic control in this population needs to be assessed formally before being accepted into standard practice

    Water, Sanitation and Hygiene Conditions in Kenyan Rural Schools: Are Schools Meeting the Needs of Menstruating Girls?

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    Water, sanitation and hygiene (WASH) programs in African schools have received increased attention, particularly around the potential impact of poor menstrual hygiene management (MHM) on equity for girls’ education. This study was conducted prior to a menstrual feasibility study in rural Kenya, to examine current WASH in primary schools and the resources available for menstruating schoolgirls. Cross-sectional surveys were performed in 62 primary schools during unannounced visits. Of these, 60% had handwashing water, 13% had washing water in latrines for menstruating girls, and 2% had soap. Latrines were structurally sound and 16% were clean. Most schools (84%) had separate latrines for girls, but the majority (77%) had no lock. Non-governmental organizations (NGOs) supported WASH in 76% of schools. Schools receiving WASH interventions were more likely to have: cleaner latrines (Risk Ratio (RR) 1.5; 95% Confidence Intervals [CI] 1.0, 2.1), handwashing facilities (RR 1.6, CI 1.1, 2.5), handwashing water (RR 2.7; CI 1.4, 5.2), and water in girls’ latrines (RR 4.0; CI 1.4, 11.6). Schools continue to lack essential WASH facilities for menstruating girls. While external support for school WASH interventions improved MHM quality, the impact of these contributions remains insufficient. Further support is required to meet international recommendations for healthy, gender-equitable schools

    Continuous-time modelling of behavioural responses in animal movement

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    Funding: TM, RG, CH, and LT were funded by the US office of Naval Research, Grant N000141812807. This work was supported by the US Fleet Forces Command through the Naval Facilities Engineering Command Atlantic under Contract No. N62470-15-D-8006, Task Order 50, Issued to HDR, Inc.There is great interest in ecology to understand how wild animals are affected by anthropogenic disturbances, such as sounds. For example, behavioural response studies are an important approach to quantify the impact of naval activity on marine mammals. Controlled exposure experiments are undertaken where the behaviour of animals is quantified before, during, and after exposure to a controlled sound source, often using telemetry tags (e.g., accelerometers, or satellite trackers). Statistical modelling is required to formally compare patterns before and after exposure, to quantify deviations from baseline behaviour. We propose varying-coefficient stochastic differential equations (SDEs) as a flexible framework to model such data, with two components: (1) time-varying baseline dynamics, modelled with non-parametric or random effects of time-varying covariates, and (2) a nonparametric response model, which captures deviations from baseline. SDEs are specified in continuous time, which makes it straightforward to analyse data collected at irregular time intervals, a common situation for animal tracking studies. We describe how the model can be embedded into a state-space modelling framework to account for measurement error. We present inferential methods for model fitting, model checking, and uncertainty quantification (including on the response model). We apply this approach to two behavioural response study data sets on beaked whales: a satellite track, and high-resolution depth data. Our results suggest that the whales’ horizontal movement and vertical diving behaviour changed after exposure to the sound source, and future work should evaluate the severity and possible consequences of these responses. These two very different examples showcase the versatility of varying-coefficient SDEs to measure changes in behaviour, and we discuss implications of disturbances for the whales’ energetic balance.PostprintPeer reviewe

    The Process and a Pitfall in Developing Biology and Chemistry Problems for Mathematics Courses

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    In this paper, we describe our process for developing applied problems from biology and chemistry for use in a differential calculus course. We describe our conversations and curricular analyses that led us to change from our initial focus on college algebra to calculus. We provide results that allowed us to see the overlaps between biology and mathematics and chemistry and mathematics and led to a specific focus on problems related to rates of change. Finally, we investigate the problems that were developed by the partner disciplines for use on recitation activities in calculus and how those problems were modified by the calculus coordinator. We compare what partner disciplines emphasize in scientific applications with what mathematics instructors emphasize in calculus and consider what that means for students’ understanding of science in mathematics. We also describe the role of the students, partner discipline colleagues, and calculus instructors in the development, refinement, and use of the problems
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