671 research outputs found
Quantifying the Socio-Economic Benefits of Reducing Industrial Dietary Trans Fats: Modelling Study.
BACKGROUND: Coronary Heart Disease (CHD) remains a leading cause of UK mortality, generating a large and unequal burden of disease. Dietary trans fatty acids (TFA) represent a powerful CHD risk factor, yet to be addressed in the UK (approximately 1% daily energy) as successfully as in other nations. Potential outcomes of such measures, including effects upon health inequalities, have not been well quantified. We modelled the potential effects of specific reductions in TFA intake on CHD mortality, CHD related admissions, and effects upon socioeconomic inequalities. METHODS & RESULTS: We extended the previously validated IMPACTsec model, to estimate the potential effects of reductions (0.5% & 1% reductions in daily energy) in TFA intake in England and Wales, stratified by age, sex and socioeconomic circumstances. We estimated reductions in expected CHD deaths in 2030 attributable to these two specific reductions. Output measures were deaths prevented or postponed, life years gained and hospital admissions. A 1% reduction in TFA intake energy intake would generate approximately 3,900 (95% confidence interval (CI) 3,300-4,500) fewer deaths, 10,000 (8,800-10,300) (7% total) fewer hospital admissions and 37,000 (30,100-44,700) life years gained. This would also reduce health inequalities, preventing five times as many deaths and gaining six times as many life years in the most deprived quintile compared with the most affluent. A more modest reduction (0.5%) would still yield substantial health gains. CONCLUSIONS: Reducing intake of industrial TFA could substantially decrease CHD mortality and hospital admissions, and gain tens of thousands of life years. Crucially, this policy could also reduce health inequalities. UK strategies should therefore aim to minimise industrial TFA intake
Influence of constituents on the properties of self compacting repair materials
The paper presents the results of laboratory tests and field application in a highway bridge of self compacting repair materials. Three commercially available repair materials and one specially designed self compacting concrete were used in the study. The properties investigated were shrinkage, creep, elastic modulus and modulus of rupture. In addition, the field investigation determined flowing characteristics, compactibility and placing procedure of the flowing materials. The laboratory results show that the constituents of the mixtures greatly influence the basic properties of the materials. Inclusion of coarse aggregate in the mixture generally lowered the free shrinkage and modulus of rupture. Creep was highest in the material with polymer modification but creep recovery was lowest where large size aggregate was present. The elastic modulus was also influenced by the addition of coarse aggregate and copolymers The field results show that the materials can be placed and compacted satisfactorily without the aid of mechanical equipment
A Study of Aluminium Zinc Indium Thermal Spray Coatings for the Protection of Steel Rebars in Reinforced Concrete
Long-term performance of high-stiffness repairs in highway structures
This paper presents the results of field monitoring of repair patches in two reinforced concrete highway bridges, Lawns Lane Bridge on the M1 and Gunthorpe Bridge across the River Trent. The repairs were applied by spraying (guniting) repair materials to compression members of the bridges. The structural members were unpropped during repair and throughout the 60 week monitoring period. The strains in the repair patches were monitored with vibrating-wire gauges. Four different repair materials were investigated whose elastic modulus was greater than that of the substrate concrete (E-rm > E-sub). The results show that efficient repairs are achieved with E-rm> E-sub, the optimum relationship being E-rm > 1.3E(sub). This enables the repair material to shed a significant proportion of its shrinkage strain to the substrate, thereby reducing restrained-shrinkage tension. It also enables the repair to attract externally applied load from the substrate in the long term. The effect of creep and shrinkage on the performance of the repair patch is also determined. Overall, the results show that current repair standards have limitations with respect to repair material specifications
Factors affecting the efficiency of repair to propped and unpropped bridge beams
This paper presents the results of laboratory and field investigations of bridge beams repaired both under propped and unpropped conditions. In the laboratory beams were repaired using hand-applied repairs. Repairs to beams in two highway, bridges were carried out using both hand-applied and flowing repairs. The repair materials used were commercial products of wide-ranging properties (shrinkage, creep and elastic modulus). Both low stiffness repair materials of elastic modulus, E-rm, less than the substrate E-sub, and high stiffness repair materials (E-rm > E-sub) were used. The repairs were applied in the tensile zone of the beams. Strain distributions in the different phases of repair patches were monitored under service loading for a period of up to 240 weeks. The results show that high structural efficiency is achieved with repairs having E-rm > E-sub, other properties (shrinkage and creep) being within reasonable limits. Such repairs ave less plane to restrained shrinkage cracking and show a capacity for load redistribution into the repair patch. Low stiffness repairs (E-rm < E-sub), on the other hand, are prone to restrained shrinkage cracking and are ineffective in load-sharing with the substrate. Repairs to propped flexural members developed erratic and non-uniform load distribution in the different phases upon reapplication of load. Composite action between the repair patch and the substrate results in cracking in the repair patch, rendering the repairs structurally inefficient
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Apes, essences, and races: What natural scientists believed about human variation, 1700-1900
Scientific views on human variation and the relationship between humans and apes changed dramatically between 1700-1900. This paper traces the history of those changes from an initial consensus on the homogeneity of man and on casual models tied to environmental contrasts to the turn of the 20th century when "race was everything". Over the course of these two centuries new sciences were born and matured and vast quantities of data were collected, generated and digested. Yet, paradoxically, while the overwhelming majority of data indicated that discrete interpopulational contrasts among humans were elusive, the broader social constructs, likely among them economics, would rely on a scientific foundation that viewed the differences as innate and fixed. By the turn of the twentieth century Europeans and European-Americans would explain their economic and military superiority in biological terms, even if contradicted by the data. Through an analysis of changing perspectives on the key underlying constructs of essentialism, fixity and ranking, we try to understand these shifting views on the nature of human variation
Comparison of Generic and Proprietary Sodium Stibogluconate for the Treatment of Visceral Leishmaniasis in Kenya.
OBJECTIVE: To compare the use of generic and proprietary sodium stibogluconate for the treatment of visceral leishmaniasis (kala-azar). METHODS: A total of 102 patients with confirmed kala-azar were treated in a mission hospital in West Pokot region, Kenya, with sodium stibogluconate (20 mg/kg/day for 30 days)--either as Pentostam (PSM) or generic sodium stibogluconate (SSG); 51 patients were allocated alternately to each treatment group. FINDINGS: There were no significant differences in baseline demographic characteristics or disease severity, or in events during treatment. There were 3 deaths in the PSM group and 1 in the SSG group; 2 patients defaulted in each group. Only 1 out of 80 test-of-cure splenic aspirates was positive for Leishmania spp.; this patient was in the SSG group. Follow-up after > or = 6 months showed that 6 out of 58 patients had relapsed, 5 in the SSG group and 1 in the PSM group. No outcome variable was significantly different between the two groups. CONCLUSION: The availability of cheaper generic sodium stibogluconate, subject to rigid quality controls, now makes it possible for the health authorities in kala-azar endemic areas to provide treatment to many more patients in Africa
Comparing Strategies to Prevent Stroke and Ischemic Heart Disease in the Tunisian Population: Markov Modeling Approach Using a Comprehensive Sensitivity Analysis Algorithm.
Background. Mathematical models offer the potential to analyze and compare the effectiveness of very different interventions to prevent future cardiovascular disease. We developed a comprehensive Markov model to assess the impact of three interventions to reduce ischemic heart diseases (IHD) and stroke deaths: (i) improved medical treatments in acute phase, (ii) secondary prevention by increasing the uptake of statins, (iii) primary prevention using health promotion to reduce dietary salt consumption. Methods. We developed and validated a Markov model for the Tunisian population aged 35–94 years old over a 20-year time horizon. We compared the impact of specific treatments for stroke, lifestyle, and primary prevention on both IHD and stroke deaths. We then undertook extensive sensitivity analyses using both a probabilistic multivariate approach and simple linear regression (metamodeling). Results. The model forecast a dramatic mortality rise, with 111,134 IHD and stroke deaths (95% CI 106567 to 115048) predicted in 2025 in Tunisia. The salt reduction offered the potentially most powerful preventive intervention that might reduce IHD and stroke deaths by 27% (−30240 [−30580 to −29900]) compared with 1% for medical strategies and 3% for secondary prevention. The metamodeling highlighted that the initial development of a minor stroke substantially increased the subsequent probability of a fatal stroke or IHD death. Conclusions. The primary prevention of cardiovascular disease via a reduction in dietary salt consumption appeared much more effective than secondary or tertiary prevention approaches. Our simple but comprehensive model offers a potentially attractive methodological approach that might now be extended and replicated in other contexts and populations
Influence of resistivity on current and potential distribution of cathodic protection systems for steel framed masonry structures
The present paper presents the influence of resistivity on the current and potential distribution of cathodic protection (CP) systems for steel framed masonry structures. The work involves both experimental measurements and boundary element analysis and follows on from earlier experiments employing sand as a simple model for masonry encasement that has been reported elsewhere. Factors such as the size and type of masonry, moisture content and width of mortar joints will affect the resistance of the path through which the CP currents pass and thereby influence the distribution onto the steel surface. To represent such variations in resistance, it has been necessary to construct a small scale specimen replicating, as far as possible, actual applications on steel framed structures. The results from the laboratory specimen and numerical modelling are in sufficient agreement to confirm the validity of the modelling approach and allow the results to be employed for the purposes of design and development
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