Why traditional approaches to on-site sanitation provision are failing poor households

Towns and cities across Africa are growing fast and poor settlements are under increasing pressure. The numbers without adequate sanitation continue to grow. Health and hygiene education and social marketing aim to address this, persuading poor communities to change behaviours and invest in household-level sanitation. However, recent BPD work on ‘sanitation partnerships’ in five African cities highlighted two worrying issues. Firstly, many urban poor are tenants rather than owners, whose incentives to invest in sanitation are weak at best. Secondly, to the detriment of many poor communities, the emptying of latrines is often overlooked. This note discusses the impact of these two issues and goes on to propose how ‘mapping the territory’ and the linkages of a ‘sanitation service’ can help external agencies. We also suggest a short checklist for those working with on-site sanitation

Work limitations and employer adjustments for employees with chronic illness

This study measured work limitations and work adjustments among chronically ill employees with regard to three distinct job characteristics: physical work demands, cognitive work demands and social work demands. The study presents findings from an organizational-based survey, from which 610 respondents reported managing employees with a chronic illness. These included arthritis, musculoskeletal pain, diabetes, asthma, migraine, heart disease, irritable bowel syndrome and depression. The results indicate that depression had the largest impact in all three work demand categories, while musculoskeletal pain principally affected physical work demands and migraine and diabetes largely affected cognitive work demands. For other chronic illnesses, it was the generic symptoms of the illness (for example, fatigue) that resulted in a work limitation, rather than the specific nature of the illness itself. Employer work adjustments were available to those people with illnesses that required a physical work adjustment (for example, musculoskeletal pain). For other chronic illnesses, with the exception of depression, disclosing an illness was the strongest predictor for work adjustments in cognitive tasks and the provision of social support. Those with depression were least likely to receive a cognitive work adjustment, indicating either a low disclosure rate in this group or that employers' perceptions of depression may be a barrier to providing suitable work adjustments

Modelling factors in primary care quality improvement: a cross-sectional study of premature CHD mortality.

Objectives: To identify features of primary care quality improvement associated with improved health outcomes using premature coronary heart disease (CHD) mortality as an example, and to determine impacts of different modelling approaches. Design: Cross-sectional study of mortality rates in 229 general practices. Setting: General practices from three East Midlands primary care trusts. Participants: Patients registered to the practices above between April 2006 and March 2009. Main outcome measures: Numbers of CHD deaths in those aged under 75 (premature mortality) and at all ages in each practice. Results: Population characteristics and markers of quality of primary care were associated with variations in premature CHD mortality. Increasing levels of deprivation, percentages of practice populations on practice diabetes registers, white, over 65 and male were all associated with increasing levels of premature CHD mortality. Control of serum cholesterol levels in those with CHD and the percentage of patients recalling access to their preferred general practitioner were both associated with decreased levels of premature CHD mortality. Similar results were found for all-age mortality. A combined measure of quality of primary care for CHD comprising 12 quality outcomes framework indicators was associated with decreases in both all-age and premature CHD mortality. The selected models suggest that practices in less deprived areas may have up to 20% lower premature CHD mortality than those with median deprivation and that improvement in the CHD care quality from 83% (lower quartile) to 86% (median) could reduce premature CHD mortality by 3.6%. Different modelling approaches yielded qualitatively similar results. Conclusions: High-quality primary care, including aspects of access to and continuity of care, detection and management, appears to be associated with reducing CHD mortality. The impact on premature CHD mortality is greater than on all-age CHD mortality. Determining the most useful measures of quality of primary care needs further consideration

Non-destructive, safe removal of conductive metal coatings from fossils: a new solution

Scanning electron microscopy, and some other imaging techniques, commonly require that specimens to be imaged are coated with a conductive metal, such as gold, gold-palladium, platinum or silver. However, the application of metal coatings changes the appearance of specimens and can obscure important features, and thus may be undesirable, or even prohibited by institutions or curators. We describe a harmless, straightforward and inexpensive technique for removing gold. The method involves immersing samples in ionic liquids and rinsing in water. No further handling is needed, no poisonous compounds are utilised in the process, and the liquids may be tailored to remove other metal coatings without affecting the adhesive used to attach the specimen to the substrat

Analysis of a cross groove constant velocity joint mechanism designed for high performance racing conditions

Constant Velocity Joint (CVJ) mechanisms enable torque transmission between two shafts at a fixed or variable angle. Cross groove CVJs are typically used in high performance automotive applications due to their versatility and light weight. Critical failure modes, such as pitting or abrasive wear, occur due to the harsh tribological conditions at ball reversals. In this research, an existing mathematical model is developed further for the case of cross groove CVJs including an accurate contact mechanics model. The developed model is validated against a published data set from literature. Surface topography of worn raceways are experimentally measured and the results from the developed model are corroborated with the measured surface parameters. This improved model shows the correlations between predicted contact force variation and wear scar depths during ball reversals, hitherto not reported in the literature.</p

Multibody dynamics of cross groove constant velocity ball joints for high performance racing applications

Accurate prediction of constant velocity joint transient contact loading and complex kinematics is necessary to improve joint design and prevent incurring failure from rolling contact fatigue. A detailed multibody dynamic model is presented for cross groove constant velocity joints used in high performance automotive racing applications, hitherto not reported in the open literature. The developed model includes detailed contact mechanics and friction models for all contacts made between the components. A novel semi-Hertzian contact model is adopted for the cage-race conjunction. Local contact kinematics is evaluated based on a methodology used in tribological analysis. The proposed model is validated against available computational models provided in literature for cross groove designs. Using the model, contact pressures occurring in the ball-race and ball-cage contacts are shown to reach levels as high as 4 and 5 GPa, respectively. The assumed value of friction coefficient is shown to have a strong influence on the predicted contact forces. Local contact motions are presented for the ball-race and ball-cage contacts, demonstrating complex motion which varies between pure rolling and pure sliding within a single cycle.</p

An analytical friction model for point contacts subject to boundary and mixed elastohydrodynamic lubrication

An analytical EHL model suitable for highly loaded point contacts operating in mixed and boundary regimes of lubrication is presented. The results are compared and validated with the experimental measurements of friction coefficient from an MTM tribometer. Measurements are carried out upon a PAO40 oil at medium to high temperatures. In general, a good agreement in trend and magnitude over a wide range of operating conditions is observed. Both the experimental findings and the model predictions show an inverse relationship between friction and contact load in mixed and boundary regimes of lubrication, an effect not hitherto reported in literature.</p

Canopy transpiration of Jeffrey pine in mesic and xeric microsites: O3 uptake and injury response

Canopy transpiration of mature Jeffrey pine was compared in "mesic" and "xeric" microsites differing in topographical position, bole growth, and the level of drought stress experienced. Diurnal and seasonal course of canopy transpiration was monitored with thermal dissipation probes in 1999 and 2000. Mid-canopy measures of diurnal foliar stomatal conductance (gs) were taken in June and August in 1999. In early summer, there was little difference between trees in either microsite with regard to gs (55 mmol H2O m-2s-1), canopy transpiration (4.0 1 h-1), and total duration of active transpiration (12 h >0.03 1 h-1). In late summer, xeric trees had a lower daily maximum gs (by 30%), a greater reduction in whole canopy transpiration relative to the seasonal maximum (66 vs 79%), and stomata were open 2 h less per day than in mesic trees. Based on leaf-level gas exchange measurements, trees in mesic sites had an estimated 46% decrease in O3 uptake from June to August. Xeric trees had an estimated 72% decrease over the same time period. A multivariate analysis of morphological and tissue chemistry attributes in mid-canopy elucidated differences in mesic and xeric tree response. Mesic trees exhibited more O3 injury than xeric trees based on reduced foliar nitrogen content and needle retention in mid-canopy

Additional file 2: of A decision analytic model to investigate the cost-effectiveness of poisoning prevention practices in households with young children

Sensitivity Analyses (SA). (DOCX 13 kb

Mechanical evaluation and failure analysis of composite laminates manufactured using automated dry fibre tape placement followed by liquid resin infusion

Automated tape placement is seen as a promising technique for the manufacture of net-shape dry fibre preforms using carbon fibre tapes. However, most of the dry fibre tapes (DFT) available on the market are proprietary and aimed mainly at the aerospace sector. In the current study, two different binders (polyurethane and phenoxy water based binder) were used to coat and hence stabilise the carbon fibre tows. A net shaped preform was manufactured using Laser-Assisted Dry Fibre Tape Placement (LDFTP) and subsequently infused by vacuum assisted liquid resin infusion. The mechanical properties of the resulting laminates were compared to the laminates where the preform was manually laid up by hand with and without a coating (baseline). Failure mechanism analysis was carried out using scanning electron microscopy (SEM). The LDFTP process improved cured ply thickness (17–20% reduction) and fibre volume fraction (+9%). Interlaminar shear strength (ILSS) showed a significant improvement of 35–48%. However, only laminates manufactured using phenoxy coated LDFTP manufactured preforms showed comparable flexural strength to the uncoated baseline. Flexural modulus reduced in all cases. Further optimisation of binder content and process parameters (layup rate, consolidation temperature) is required for high speed deposition, better consolidation and improvements in mechanical properties