502 research outputs found

    The effects of particle size on the optical properties and surface roughness of a glass-balloon-filled black paint

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    The effects of particle size on the optical properties and surface roughness of a glass-balloon-filled, carbon-pigmented paint were studied in order to develop a diffuse-reflecting, low-total-reflectance, low-outgassing black paint. Particle sizes ranged between 20 microns and 74 microns. Surface roughness was found to increase with increasing particle size. Relative total reflectance at near-normal incidence (MgO standard) of the filled paints was less than for the unfilled paint between 230 nm and 1800 nm. Total absolute reflectance at 546 nm decreased with increasing particle size at grazing angles of incidence. Near-normal, total emittance was greater for the filled paints than for the unfilled paint. Specularity decreased with increasing particle size over the range studied

    Community based rehabilitation after severe traumatic brain injury: a randomised controlled trial

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    Objective: Evaluation of multidisciplinary community based outreach rehabilitation after severe traumatic brain injury (TBI). Methods: A randomised controlled trial compared outreach treatment (mean of two sessions a week for 27.3 (SD 19.1) weeks) in community settings such as participants' homes, day centres, or workplaces, with provision of written information detailing alternative resources. Follow up for an average of 24.8 months after initial allocation was by a blinded independent assessor. Participants were aged 16–65, had sustained severe TBI between 3 months and 20 years previously, and had no other neurological conditions. Of 110 initially allocated, 48 outreach and 46 information participants were successfully followed up. Primary outcome measures (Barthel index (BI) and the brain injury community rehabilitation outcome-39 (BICRO-39)) focused on levels of activity and participation. Secondary measures were the functional independence measure and the functional assessment measure (FIM+FAM) and, in a subgroup of 46 participants, the hospital anxiety and depression scale. Analyses were non-parametric. Results: outreach participants were significantly more likely to show gains on the BI and the BICRO-39 total score and self organisation and psychological wellbeing subscales. There were likewise strong trends (p<0.10) for BICRO personal care and mobility, and on the FIM+FAM for personal care and cognitive functions. Differential improvements were not seen for indices of socialising, productive employment, anxiety, or depression. Median changes on individual subscales were small, reflecting the diversity of the clinical population; however, 40% of outreach but only 20% of information participants made a clinically significant improvement of 2+ points on at least one BICRO-39 scale. Time since injury was unrelated to the magnitude of gains. Conclusions: This is the first RCT of multidisciplinary community rehabilitation after severe TBI, and suggests that even years after injury it can yield benefits which outlive the active treatment period

    Regionalization Versus Competition in Complex Cancer Surgery

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    The empirical association between high hospital procedure volume and lower mortality rates has led to recommendations for the regionalization of complex surgical procedures. While regionalization may improve outcomes, it also reduces market competition, which has been found to lower prices and improve health care quality. This study estimates the potential net benefits of regionalizing the Whipple surgery for pancreatic cancer patients. We confirm that increased hospital volume and surgeon volume are associated with lower inpatient mortality rates. We then predict the price and outcome consequences of concentrating Whipple surgery at hospitals that perform at least two, four, and six procedures respectively per year. Our consumer surplus calculations suggest that regionalization can increase consumer surplus, but potential price increases extract over half of the value of reduced deaths from regionalization. We reach three conclusions. First, regionalization can increase consumer surplus, but the benefits may be substantially less than implied by examining only the outcome side of the equation. Second, modest changes in outcomes due to regionalization may lead to decreases in consumer surplus. Third, before any regionalization policy is implemented, a deep and precise understanding of the nature of both outcome/volume and price/competition relationships is needed

    Ontario Native Canadians and World War One

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    While 35% of eligible Native Ontario Indians joined Canada's armed forces, the war strengthened Native resolve to resist assimilation, and spurred them to postwar political action, though internal unity eluded them

    Guidance for researchers wanting to link NHS data using non-consent approaches: a thematic analysis of feedback from the Health Research Authority Confidentiality Advisory Group

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    Introduction: The use of linked data and non-consent methodologies is a rapidly growing area of health research due to the increasing detail, availability and scope of routinely collected electronic health records data. However, gaining the necessary legal and governance approvals to undertake data linkage is a complex process in England. / Objectives: We reflect on our own experience of establishing lawful basis for data linkage through Section 251 approval, with the intention to build a knowledgebase of practical advice for future applicants. / Methods: Thematic analysis was conducted on a corpus of Section 251 feedback reports from the NHS Health Research Authority Confidentiality Advisory Group. / Results: Four themes emerged from the feedback. These were: (a) Patient and Public Involvement, (b)~Establishing Rationale, (c) Data maintenance and contingency, and the need to gain (d) Further Permissions from external authorities prior to full approval. / Conclusions: Securing Section 251 approval poses ethical, practical and governance challenges. However, through a comprehensive, planned approach Section 251 approval is possible, enabling researchers to unlock the potential of linked data for the purposes of health research

    Age-Related Disparities in Trauma Center Access for Severe Head Injuries Following the Release of the Updated Field Triage Guidelines

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    Objective: In 2006, the American College of Surgeons’ Committee on Trauma and the Center for Disease Control released field triage guidelines with special consideration for older adults. Additional considerations for direct transport to a Level I or II trauma center (TC) were added in 2011, reflecting perceived undertriage to TCs for older adults. We examined whether age-based disparities in TC care for severe head injury decreased following introduction of the 2011 revisions. Methods: A pre-post design analyzing the 2009 and 2012 Healthcare Cost and Utilization Project State Emergency Department Databases (SEDD) and State Inpatient Databases (SID) with multivariable logistic regressions considered changes in (1) the trauma designation of the emergency department where treatment was initiated and (2) transfer to a TC following initial treatment at a non-TC. Results: Compared with adults aged 18–44 years, after multivariable adjustment, in both years TC care was less likely for adults aged 45–64 years (OR: 0.76 in 2009 and 0.74 in 2012), aged 65–84 years (OR: 0.61 and 0.59), and aged 85+ years (OR: 0.53 and 0.56). Between 2009 and 2012, the likelihood of TC care increased for all age groups, with the largest increase among those aged 85+ years (OR = 1.18), which was statistically different (p = .02) from the increase among adults aged 18–44 years (OR = 1.12). The analysis of transfers yielded similar results. Conclusions: Although patterns of increased TC treatment for all groups with severe head trauma indicate improvements, age-based disparities persisted

    Simulating the Cascading Effects of an Extreme Agricultural Production Shock: Global Implications of a Contemporary US Dust Bowl Event

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    Higher temperatures expected by midcentury increase the risk of shocks to crop production, while the interconnected nature of the current global food system functions to spread the impact of localized production shocks throughout the world. In this study, we analyze the global potential impact of a present-day event of equivalent magnitude to the US Dust Bowl, modeling the ways in which a sudden decline in US wheat production could cascade through the global network of agricultural trade. We use observations of country-level production, reserves, and trade data in a Food Shock Cascade model to explore trade adjustments and country-level inventory changes in response to a major, multiyear production decline. We find that a 4-year decline in wheat production of the same proportional magnitude as occurred during the Dust Bowl greatly reduces both wheat supply and reserves in the United States and propagates through the global trade network. By year 4 of the event, US wheat exports fall from 90.5 trillion kcal before the drought to 48 trillion to 52 trillion kcal, and the United States exhausts 94% of its reserves. As a result of reduced US exports, other countries meet their needs by leveraging their own reserves, leading to a 31% decline in wheat reserves globally. These findings demonstrate that an extreme production decline would lead to substantial supply shortfalls in both the United States and in other countries, where impacts outside the United States strongly depend on a country's reserves and on its relative position in the global trade network
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