4,064 research outputs found
SCHOOL CHARACTERISTICS AND ACADEMIC PERFORMANCE IN UGANDA: EVIDENCE FROM 2001 PRIMARY LEAVING EXAMINATIONS RESULTS
Effect of staffing, supplies and facilities on primary school performance in Uganda was estimated using OLS on district level data. Parameter estimates and significance tests show that textbooks have an important influence on performance under prevailing levels of staffing and facilities. In addition, performance in schools in the northern region was lower than in the central region. This study suggests that considerable improvements in performance can be attained by additional expenditure on school textbooks.Teaching/Communication/Extension/Profession,
The perception of nurses and doctors on a care bundle guideline for management of pain in critical care
Objetivo: el objetivo de este estudio fue explorar la percepción de las enfermeras y los médicos sobre el uso de un paquete de aten- ción como una guía para el manejo del dolor en cuidados críticos. A pesar del desarrollo de guías y protocolos para el manejo del dolor en cuidados críticos, basados en la evidencia, el dolor sigue siendo un problema importante. La introducción de un paquete de atención para cuidados críticos ha mejorado el manejo de los pacientes ventilados. Un paquete de atención en el manejo del dolor tiene como objetivo reducir las variaciones en la práctica. Método: el estudio tiene un diseño prospectivo cualitativo desarrollado mediante una entrevista en profundidad y semi-estructurada de 23 enfermeros y médicos en una unidad de cuidado crítico. Resultado: cuatro temas principales surgieron: 1 ) la adecuación al escenario de cuidado crítico, 2) la aplicabilidad al escenario de cuidado crítico, 3 ) la propiedad del Paquete de Atención al Dolor, y 4) la necesidad en la práctica actual. Los resultados mostraron una pobre aceptación del paquete por parte de los profesionales de la salud en el manejo de dolor agudo en los enfermos críticos. Conclusión: el estudio encontró que las enfermeras y los médicos no percibieron el paquete de atención al dolor como una herramienta útil para mejorar el manejo del dolor, con pruebas que apuntan a una brecha entre la práctica del manejo del dolor, tal como se describe por el paquete de atención, y la práctica real.</jats:p
Measurement of Nanoparticles Release during Drilling of Polymer Nanocomposites
Nanomaterials are one of the promising technologies of this century. The Project on Emerging Nanotechnologies [1] reports more than 1600 consumer products based on nanotechnology that are currently on the market and advantages link to the reinforcement of polymeric materials using nano-fillers are not to demonstrate anymore. However, the concerns about safety and its consumer perception can slow down the acceptance of nanocomposites. Indeed, during its life-cycle, a nanotechnology-based product can release nano-sized particles exposing workers, consumers and environment and the risk involved in the use and disposal of such particles is not well known. The current legislation concerning chemicals and environment protection doesn’t explicitly cover nanomaterials and changes undergone by nanoparticles during the products’ life cycle. Also, the possible physio-chemical changes that the nanoparticles may undergo during its life cycle are unknown. Industries need a standard method to evaluate nanoparticles release during products’ life cycle in order to improve the knowledge in nanomaterials risk assessment and the legislation, and to inform customers about the safety of nanomaterials and nanoproducts. This work aims to propose a replicable method in order to assess the release of nanoparticles during the machining of nanocomposites in a controlled environment. For this purpose, a new experimental set-up was implemented and issues observed in previous methods (background noise due to uncontrolled ambient environment and the process itself, unrepeatable machining parameters) were solved. A characterisation and validation of the chamber used is presented in this paper. Also, preliminary testing on drilling of polymer-based nanocomposites (Polyamide-6/Glass Fibre reinforced with nano-SiO2) manufactured by extrusion and injection moulding were achieved
Contracts for environmental outcomes: the use of financial contracts in environmental markets
In environmental markets, parties frequently exchange obligations through environmental contracts. These contracts imply a distribution of risk between parties. The main focus of our paper is to identify contracts that enable risk in environmental markets to be reduced, distributed at least cost, or managed efficiently. The risks that we consider are: moral hazard risk, price risk, exogenous environmental risk, measurement risk and production risk. The first section of our paper outlines some of the contracts currently utilised in financial and insurance markets to achieve these objectives. These are: futures and options contracts, spread contracts, weather contracts and catastrophe bonds. We then provide a snapshot of current applications of these contracts both in real markets and in the literature. Finally we discuss some possible applications in the environmental sector and indicate how the use of these contracts may alter the way government manages environmental assets and responsibilities. We also suggest a staged process to the introduction of contracts that recognises the current limitations faced by government. This paper does not propose new or novel contracts for tackling the problems of risk in exchange. Rather it extends the application of existing contractual arrangements to a new type of problem: environmental markets.Environmental Economics and Policy,
A comparison of statistical and machine learning methods for creating national daily maps of ambient PM concentration
A typical problem in air pollution epidemiology is exposure assessment for
individuals for which health data are available. Due to the sparsity of
monitoring sites and the limited temporal frequency with which measurements of
air pollutants concentrations are collected (for most pollutants, once every 3
or 6 days), epidemiologists have been moving away from characterizing ambient
air pollution exposure solely using measurements. In the last few years,
substantial research efforts have been placed in developing statistical methods
or machine learning techniques to generate estimates of air pollution at finer
spatial and temporal scales (daily, usually) with complete coverage. Some of
these methods include: geostatistical techniques, such as kriging; spatial
statistical models that use the information contained in air quality model
outputs (statistical downscaling models); linear regression modeling approaches
that leverage the information in GIS covariates (land use regression); or
machine learning methods that mine the information contained in relevant
variables (neural network and deep learning approaches). Although some of these
exposure modeling approaches have been used in several air pollution
epidemiological studies, it is not clear how much the predicted exposures
generated by these methods differ, and which method generates more reliable
estimates. In this paper, we aim to address this gap by evaluating a variety of
exposure modeling approaches, comparing their predictive performance and
computational difficulty. Using PM in year 2011 over the continental
U.S. as case study, we examine the methods' performances across seasons, rural
vs urban settings, and levels of PM concentrations (low, medium, high)
Modelling and validation of synthesis of poly lactic acid using an alternative energy source through a continuous reactive extrusion process
PLA is one of the most promising bio-compostable and bio-degradable thermoplastic polymers made from renewable sources. PLA is generally produced by ring opening polymerization (ROP) of lactide using the metallic/bimetallic catalyst (Sn, Zn, and Al) or other organic catalysts in a suitable solvent. In this work, reactive extrusion experiments using stannous octoate Sn(Oct)2 and tri-phenyl phosphine (PPh)3 were considered to perform ROP of lactide. Ultrasound energy source was used for activating and/or boosting the polymerization as an alternative energy (AE) source. Ludovic® software, designed for simulation of the extrusion process, had to be modified in order to simulate the reactive extrusion of lactide and for the application of an AE source in an extruder. A mathematical model for the ROP of lactide reaction was developed to estimate the kinetics of the polymerization process. The isothermal curves generated through this model were then used by Ludovic software to simulate the “reactive” extrusion process of ROP of lactide. Results from the experiments and simulations were compared to validate the simulation methodology. It was observed that the application of an AE source boosts the polymerization of lactide monomers. However, it was also observed that the predicted residence time was shorter than the experimental one. There is potentially a case for reducing the residence time distribution (RTD) in Ludovic® due to the ‘liquid’ monomer flow in the extruder. Although this change in parameters resulted in validation of the simulation, it was concluded that further research is needed to validate this assumption
Developing a National Design Scoreboard
Recognising the growing importance of design, this paper reports on the development of an approach to measuring design at a national level. A series of measures is proposed, that are based around a simplified model of design as a system at a national level. This model was developed though insights from literature and a workshop with government, industry and design sector representatives. Detailed data on design in the UK is presented to highlight the difficulties in collecting reliable and robust data. Evidence is compared with four countries (Spain, Canada, Korea and Sweden). This comparison highlights the inherent difficulties in comparing performance and a revised set of measures is proposed. Finally, an approach to capturing design spend at a firm level is proposed, based on insights from literature and case studies.
Keywords:
National Design System, Design Performance</p
Cognitive Demands of Semi-Natural Virtual Locomotion
There is currently no fully natural, general-purpose locomotion interface. Instead, interfaces such as gamepads or treadmills are required to explore large virtual environments (VEs). Furthermore, sensory feedback that would normally be used in real-world movement is often restricted in VR due to constraints such as reduced field of view (FOV). Accommodating these limitations with locomotion interfaces afforded by most virtual reality (VR) systems may induce cognitive demands on the user that are unrelated to the primary task to be performed in the VE. Users of VR systems often have many competing task demands, and additional cognitive demands during locomotion must compete for finite resources. Two studies were previously reported investigating the working memory demands imposed by semi-natural locomotion interfaces (Study 1) and reduced sensory feedback (Study 2). This paper expands on the previously reported results and adds discussion linking the two studies. The results indicated that locomotion with a less natural interface increases spatial working memory demands, and that locomotion with a lower FOV increases general attentional demands. These findings are discussed in terms of their practical implications for selection of locomotion interfaces when designing VEs
Systems intervention to promote colon cancer screening in safety net settings: Protocol for a community-based participatory randomized controlled trial
BACKGROUND: Colorectal cancer is a leading cause of cancer mortality. Screening can be effective but is underutilized. System- or multi-level interventions could be effective at increasing screening, but most have been implemented and evaluated in higher-resource settings such as health maintenance organizations. Given the disparities evident for colorectal cancer and the potential for screening to improve outcomes, there is a need to expand this work to include diverse settings, including those who treat economically disadvantaged patients. This paper describes the study protocol for a trial designed to increase colorectal cancer screening in those ‘safety-net’ health centers that serve underinsured and uninsured patients. This trial was designed and is being implemented using a community-based participatory approach. METHODS/DESIGN: We developed a practical clinical cluster-randomized controlled trial. We will recruit 16 community health centers to this trial. This systems-level intervention consists of a menu of evidence-based implementation strategies for increasing colorectal cancer screening. Health centers in the intervention arm then collaborate with the study team to tailor strategies to their own setting in order to maximize fit and acceptability. Data are collected at the organizational level through interviews, and at the provider and patient levels through surveys. Patients complete a survey about their healthcare and screening utilization at baseline, six months, and twelve months. OUTCOMES: The primary outcome is colorectal cancer screening by patient self-report, supplemented by a chart-audit in a subsample of patients. Implementation outcomes informed by the Reach, Efficacy/Effectiveness, Adoption, Implementation, and Maintenance (RE-AIM) conceptual framework will be measured at patient, provider, and practice levels. DISCUSSION: Our study is one of the first to integrate community participatory strategies to a randomized controlled trial in a healthcare setting. The multi-level approach will support the ability of the intervention to affect screening through multiple avenues. The participatory approach will strengthen the chance that implementation strategies will be maintained after study completion and, supports external validity by increasing health center interest and willingness to participate. TRIAL REGISTRATION: NCT0129949
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