861 research outputs found
Panels illuminated by edge-lighted lens technique
Electroluminescent lamps used to edge-light a specially ground lens provide nonglare, reduced eye strain panel illumination. There is no noticeable falloff in brightness along the lens edge. Light intensity diminishes toward the lens center. A slight halo, observed along the lens edge, has no detrimental effect
Comparison of Two Detailed Models of Aedes aegypti Population Dynamics
The success of control programs for mosquito-borne diseases can be enhanced by crucial information provided by models of the mosquito populations. Models, however, can differ in their structure, complexity, and biological assumptions, and these differences impact their predictions. Unfortunately, it is typically difficult to determine why two complex models make different predictions because we lack structured side-by-side comparisons of models using comparable parameterization. Here, we present a detailed comparison of two complex, spatially explicit, stochastic models of the population dynamics of Aedes aegypti, the main vector of dengue, yellow fever, chikungunya, and Zika viruses. Both models describe the mosquito?s biological and ecological characteristics, but differ in complexity and specific assumptions. We compare the predictions of these models in two selected climatic settings: a tropical and weakly seasonal climate in Iquitos, Peru, and a temperate and strongly seasonal climate in Buenos Aires, Argentina. Both models were calibrated to operate at identical average densities in unperturbedconditions in both settings, by adjusting parameters regulating densities in each model (number of larval development sites and amount of nutritional resources). We show that the models differ in their sensitivityto environmental conditions (temperature and rainfall) and trace differences to specific model assumptions.Temporal dynamics of the Ae. aegypti populations predicted by the two models differ more markedly under strongly seasonal Buenos Aires conditions. We use both models to simulate killing of larvae and/or adults with insecticides in selected areas. We show that predictions of population recovery by the models differ substantially, an effect likely related to model assumptions regarding larval development and (director delayed) density dependence. Our methodical comparison provides important guidance for model improvement by identifying key areas of Ae. aegypti ecology that substantially affect model predictions, and revealing the impact of model assumptions on population dynamics predictions in unperturbed and perturbed conditions.Fil: Legros, Mathieu. University of North Carolina; Estados UnidosFil: Otero, Marcelo Javier. Universidad de Buenos Aires; ArgentinaFil: Romeo Aznar, Victoria Teresa. Universidad de Buenos Aires; ArgentinaFil: Solari, Hernan Gustavo. Universidad de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; ArgentinaFil: Gould, Fred. National Institutes of Health; Estados UnidosFil: Lloyd, Alun L.. National Institutes of Health; Estados Unido
Costs of vitamin D testing and prescribing among children in primary care
Vitamin D has attracted considerable interest in recent years, with a marked increase in diagnosis of vitamin D deficiency seen among children in clinical practice in the UK. The economic implications of this change in diagnostic behaviour have not been explored. We performed a cohort study to examine longitudinal trends in healthcare expenditure arising from vitamin D testing and prescribing for children in primary care in England, using the electronic healthcare records of 722,525 children aged 0–17 years held in The Health Improvement Network database. Combined costs of vitamin D tests and prescriptions increased from £1647 per 100,000 person-years in 2008 (95% CI, £934 to £3007) to £28,913 per 100,000 person-years in 2014 (95% CI, £26,361 to £31,739). The total cost of vitamin D prescriptions and tests for children in primary care at the national level in England in 2014 was estimated to be £4.31 million (95% CI, £2.96–£6.48 million).
CONCLUSION: There has been a marked increase in healthcare expenditure on vitamin D tests and prescriptions for children in primary care over the past decade. Future research should explore the drivers for this change in diagnostic behaviour and the reasons prompting investigation of vitamin D status in clinical practice
Spiral strand cables subjected to high velocity fragment impact
Structural cables are widely adopted around the world in offshore construction, sports stadia, large scale bridges, Ferris wheels and suspended canopy and fabric structures. However, the robustness of such structures to blast or impact is uncertain with a particular concern related to the loss of a primary structural cable when damaged by high velocity blast fragmentation. This paper presents the first ever numerical and experimental study on commonly used high-strength steel spiral strand cables subjected to high velocity fragment impact. Spiral strand cables were impacted by 20 mm fragment simulating projectiles travelling at velocities between 200 and 1400 m/s. Complex 3D non-linear finite element models were developed and carefully compared with experimental tests. The penetration resistance of the cables and resultant damage were studied with respect to fragment impact velocity. It was found that for all the impact velocities, the fragment penetration depth was less than half of the cable diameter demonstrating a considerable amount of resilience. Considering the damage caused, the residual cable breaking strengths were estimated and found to be still higher than the minimum breaking load of an un-damaged cable. The numerical models were also able to reproduce the main features of the impact tests, including the extent of localised damage area, the fragment penetration depth and mode of individual wire failures, thus demonstrating their potential to be widely used in industry for structural resilience and robustness assessments by structural engineers
Movement side effects of antipsychotic drugs in adults with and without intellectual disability: UK population-based cohort study
OBJECTIVES: To measure the incidence of movement side effects of antipsychotic drugs in adults with intellectual disability and compare rates with adults without intellectual disability. DESIGN: Cohort study using data from The Health Improvement Network. SETTING: UK primary care. PARTICIPANTS: Adults with intellectual disability prescribed antipsychotic drugs matched to a control group of adults without intellectual disability prescribed antipsychotic drugs. OUTCOME MEASURES: New records of movement side effect including acute dystonias, akathisia, parkinsonism, tardive dyskinaesia and neuroleptic malignant syndrome. RESULTS: 9013 adults with intellectual disability and a control cohort of 34 242 adults without intellectual disability together contributed 148 709 person-years data. The overall incidence of recorded movement side effects was 275 per 10 000 person-years (95% CI 256 to 296) in the intellectual disability group and 248 per 10 000 person-years (95% CI 237 to 260) in the control group. The incidence of any recorded movement side effect was significantly greater in people with intellectual disability compared with those without (incidence rate ratio 1.30, 95% CI 1.18 to 1.42, p<0.001, after adjustment for potential confounders), with parkinsonism and akathisia showing the greatest difference between the groups. Neuroleptic malignant syndrome, although occurring infrequently, was three times more common in people with intellectual disability-prescribed antipsychotic drugs (incidence rate ratio 3.03, 95% CI 1.26 to 7.30, p=0.013). Differences in rates of movement side effects between the groups were not due to differences in the proportions prescribed first and second-generation antipsychotic drugs. CONCLUSIONS: This study provides evidence to substantiate the long-held assumption that people with intellectual disability are more susceptible to movement side effects of antipsychotic drugs. Assessment for movement side effects should be integral to antipsychotic drug monitoring in people with intellectual disability. Regular medication review is essential to ensure optimal prescribing in this group
Mental illness, challenging behaviour, and psychotropic drug prescribing in people with intellectual disability: UK population based cohort study
To describe the incidence of recorded mental illness and challenging behaviour in people with intellectual disability in UK primary care and to explore the prescription of psychotropic drugs in this group
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