Modelling household well-being and poverty trajectories: An application to coastal Bangladesh

This is the final version. Available on open access from the Public Library of Science via the DOI in this recordData Availability: All relevant data are within the manuscript and its Supporting Information files.Resource-based livelihoods are uncertain and potentially unstable due to variability over time, including seasonal variation: this instability threatens marginalised populations who may fall into poverty. However, empirical understanding of trajectories of household wellbeing and poverty is limited. Here, we present a new household-level model of poverty dynamics based on agents and coping strategies–the Household Economy And Poverty trajectory (HEAP) model. HEAP is based on established economic and social insights into poverty dynamics, with a demonstration of the model calibrated with a qualitative and quantitative household survey in coastal Bangladesh. Economic activity in Bangladesh is highly dependent on natural resources; poverty is widespread; and there is high variability in ecosystem services at multiple temporal scales. The results show that long-term decreases in poverty are predicated more on the stability of, and returns from, livelihoods rather than their diversification. Access to natural resources and ecosystem service benefits are positively correlated with stable income and multidimensional well-being. Households that remain in poverty are those who experience high seasonality of income and are involved in small scale enterprises. Hence, seasonal variability in income places significant limits on natural resources providing routes out of poverty. Further, projected economic trends to 2030 lead to an increase in well-being and a reduction in poverty for most simulated household types.Department for International Development (DFID)Economic and Social Research Council (ESRC)Natural Environment Research Council (NERC

Sensitivity and specificity of methods of classification of leprosy without use of skin-smear examination

A 12-month cohort of 2664 new leprosy cases in Bangladesh has been analyzed to provide information about the sensitivity and specificity of two different methods of classifying leprosy into paucibacillary (PB) and multibacillary (MB), if the results of skin-smear examination are not taken into account. The two methods are: 1) a procedure based on counting skin lesions recommended by the World Health Organization (WHO) (&lt;6 skin lesions = PB, ≥6 skin lesions = MB); and 2) the 'Bangladesh method' (&lt;10 skin and nerve lesions = PB, ≥10 skin and nerve lesions = MB). In the latter system, any degree of nerve enlargement is taken to be a nerve lesion. The WHO method was found to be 89% sensitive and 88% specific at detecting smear-positive MB cases from among the cohort; the Bangladesh system, 92% sensitive and 88.6% specific. The WHO method did not detect 18 smear-positive cases as MN; the Bangladesh method left 13 smear-positive cases unclassified as MB. Several of these 'missed' (false-negative) cases had a high bacterial index. The WHO system of classifying leprosy cases as MB is simple to apply and has a reasonable balance between sensitivity and specificity. However, it must be recognized that the system will lead to a small but significant number of skin-smear-positive MB cases being treated with a PB treatment regimen.</p

Sensitivity and specificity of methods of classification of leprosy without use of skin-smear examination

A 12-month cohort of 2664 new leprosy cases in Bangladesh has been analyzed to provide information about the sensitivity and specificity of two different methods of classifying leprosy into paucibacillary (PB) and multibacillary (MB), if the results of skin-smear examination are not taken into account. The two methods are: 1) a procedure based on counting skin lesions recommended by the World Health Organization (WHO) (&lt;6 skin lesions = PB, ≥6 skin lesions = MB); and 2) the 'Bangladesh method' (&lt;10 skin and nerve lesions = PB, ≥10 skin and nerve lesions = MB). In the latter system, any degree of nerve enlargement is taken to be a nerve lesion. The WHO method was found to be 89% sensitive and 88% specific at detecting smear-positive MB cases from among the cohort; the Bangladesh system, 92% sensitive and 88.6% specific. The WHO method did not detect 18 smear-positive cases as MN; the Bangladesh method left 13 smear-positive cases unclassified as MB. Several of these 'missed' (false-negative) cases had a high bacterial index. The WHO system of classifying leprosy cases as MB is simple to apply and has a reasonable balance between sensitivity and specificity. However, it must be recognized that the system will lead to a small but significant number of skin-smear-positive MB cases being treated with a PB treatment regimen.</p

Large time existence for 3D water-waves and asymptotics

We rigorously justify in 3D the main asymptotic models used in coastal oceanography, including: shallow-water equations, Boussinesq systems, Kadomtsev-Petviashvili (KP) approximation, Green-Naghdi equations, Serre approximation and full-dispersion model. We first introduce a ``variable'' nondimensionalized version of the water-waves equations which vary from shallow to deep water, and which involves four dimensionless parameters. Using a nonlocal energy adapted to the equations, we can prove a well-posedness theorem, uniformly with respect to all the parameters. Its validity ranges therefore from shallow to deep-water, from small to large surface and bottom variations, and from fully to weakly transverse waves. The physical regimes corresponding to the aforementioned models can therefore be studied as particular cases; it turns out that the existence time and the energy bounds given by the theorem are always those needed to justify the asymptotic models. We can therefore derive and justify them in a systematic way.Comment: Revised version of arXiv:math.AP/0702015 (notations simplified and remarks added) To appear in Inventione

DYNAMIC ROCK MECHANICS INVESTIGATIONS FINAL REPORT, PROJECT COWBOY

Strain gage instrumentation is reported of three Cowboy shots to measure the strain produced in salt by coupled and decoupled detonations. Linear array tests were made to develop a propagation law for strain, to determine particle velocity and acceleration in salt, to compare explosives, to determine the effect of impedance coupling between explosive and rock, and to investigate other seismic effects. Crater tests were made to determine the dynamic tensile breaking strength of salt. Tests were made to measure in situ, longitudinal (P) and shear (S) wave velocities and to calculate the dynamic elastic constants therefrom. Laboratory tests on core were made to determine the dynamic compressive and tensile breaking strength of salt. Physical properties tests were made under laboratory conditions for comparison with dynamic results. (W.L.H.

Analysis of Granular Flow in a Pebble-Bed Nuclear Reactor

Pebble-bed nuclear reactor technology, which is currently being revived around the world, raises fundamental questions about dense granular flow in silos. A typical reactor core is composed of graphite fuel pebbles, which drain very slowly in a continuous refueling process. Pebble flow is poorly understood and not easily accessible to experiments, and yet it has a major impact on reactor physics. To address this problem, we perform full-scale, discrete-element simulations in realistic geometries, with up to 440,000 frictional, viscoelastic 6cm-diameter spheres draining in a cylindrical vessel of diameter 3.5m and height 10m with bottom funnels angled at 30 degrees or 60 degrees. We also simulate a bidisperse core with a dynamic central column of smaller graphite moderator pebbles and show that little mixing occurs down to a 1:2 diameter ratio. We analyze the mean velocity, diffusion and mixing, local ordering and porosity (from Voronoi volumes), the residence-time distribution, and the effects of wall friction and discuss implications for reactor design and the basic physics of granular flow.Comment: 18 pages, 21 figure

Exploring young people's and youth workers' experiences of spaces for ‘youth development’: creating cultures of participation

The paper focuses on the emergence of ‘positive youth development’ and its impact on older, more established practices of working with young people, such as youth work. Drawing on ethnographic fieldwork in England between 2004 and 2006, in particular young people's and youth workers' accounts of participating in youth work, the analysis engages with the social spaces in which youth work takes place and asks key questions about why young people might participate in youth spaces, what they get out of participating and how such spaces can promote cultures of participation. The analysis shows that such spaces provide young people and their communities with biographical continuity and time becomes a key component for sustaining such spaces. The argument is made for a more nuanced understanding of what young people get out of their participation in youth spaces, and for an epistemological approach to youth praxis that embraces the messiness and inequalities of lived experience

Erosive osteoarthritis: a more severe form of radiographic hand osteoarthritis rather than a distinct entity?

OBJECTIVES: To determine whether erosive osteoarthritis shares the same pattern of joint involvement and risk profile as increasing grades of non-erosive hand osteoarthritis. METHODS: Participants were from two population-based cohorts, aged ≥50 years, reporting hand symptoms in the previous month. Interphalangeal joints were assessed for erosive osteoarthritis (Verbruggen-Veys erosive or remodelled phase) and radiographic osteoarthritis (sliding cut-offs of K&L≥2, K&L≥3 and K&L=4). At the joint level, similarities in the frequency and pattern of erosive and non-erosive osteoarthritis were assessed by Spearman's rank correlation coefficients and generalised estimating equations. At the person level, individuals with erosive osteoarthritis were compared to those with non-erosive osteoarthritis using logistic regression, adjusted for age and gender (aOR), for the following exposures: family history, previous injury, overuse and metabolic factors (BMI, dyslipidaemia, hypertension, diabetes). RESULTS: In 1076 symptomatic participants the ranked frequency of involvement for erosive joints was comparable to joints with K&L≥3 and K&L=4 (r>0.95). Patterns of joint involvement in erosive osteoarthritis were strongest for symmetry (aOR=6.5; 95% CI 3.0 to 14.1), followed by row (2.0; 0.8 to 5.0) and ray (0.3; 0.0 to 2.5), which was similar to joints with K&L≥3 and K&L=4. Individuals with erosive osteoarthritis (n=80) had an increased risk of metabolic syndrome (2.7; 1.0 to 7.1), notably dyslipidaemia (4.7; 2.1 to 10.6) compared with non-erosive osteoarthritis classed K&L≥3 (n=193). CONCLUSIONS: The similar frequency of radiographic joint involvement and patterning in erosive osteoarthritis and more severe non-erosive osteoarthritis is consistent with prevalent erosive osteoarthritis being a severe form of hand osteoarthritis rather than a distinct entity. Metabolic exposures, dyslipidaemia in particular, may be implicated in erosive osteoarthritis

Treatment with corticosteroids of long-standing nerve function impairment in leprosy:A randomized controlled trial (TRIPOD 3)

Some leprosy patients with long-standing nerve function impairment (NFI) appear to have responded favourably to treatment with corticosteroids. This study investigated whether patients with untreated NFI between 6 and 24 months duration and who are given standard regimen corticosteroid therapy, will have a better treatment outcome than a placebo group. A multicentre, randomized, double-blind placebo-controlled trial was conducted in Nepal and Bangladesh. Subjects were randomised to either prednisolone treatment starting at 40 mg/day, tapered by 5 mg every 2 weeks, and completed after 16 weeks, or placebo. Outcome assessments were at 4, 6, 9, and 12 months from the start of treatment. 92 MB patients on MDT were recruited, of whom 40 (45%) received prednisolone and 52 (55%) placebo treatment. No demonstrable additional improvement in nerve function, or in preventing further leprosy reaction events was seen in the prednisolone group. Overall, improvement of nerve function at 12 months was seen in about 50% of patients in both groups. Analysis of subgroups according to nerve (ulnar and posterior tibial), duration of NFI, and sensory and motor function, also did not reveal any differences between the treatment and placebo groups. There was however, indication of less deterioration of nerve function in the prednisolone group. Finally, there was no difference in the occurrence of adverse events between both groups. The trial confirms current practice not to treat long-standing NFI with prednisolone. Spontaneous recovery of nerve function appears to be a common phenomenon in leprosy. Leprosy reactions and new NFI occurred in a third of the study group, emphasizing the need to keep patients under regular surveillance during MDT, and, where possible, after completion of MDT.</p

Treatment with corticosteroids of long-standing nerve function impairment in leprosy:A randomized controlled trial (TRIPOD 3)

Some leprosy patients with long-standing nerve function impairment (NFI) appear to have responded favourably to treatment with corticosteroids. This study investigated whether patients with untreated NFI between 6 and 24 months duration and who are given standard regimen corticosteroid therapy, will have a better treatment outcome than a placebo group. A multicentre, randomized, double-blind placebo-controlled trial was conducted in Nepal and Bangladesh. Subjects were randomised to either prednisolone treatment starting at 40 mg/day, tapered by 5 mg every 2 weeks, and completed after 16 weeks, or placebo. Outcome assessments were at 4, 6, 9, and 12 months from the start of treatment. 92 MB patients on MDT were recruited, of whom 40 (45%) received prednisolone and 52 (55%) placebo treatment. No demonstrable additional improvement in nerve function, or in preventing further leprosy reaction events was seen in the prednisolone group. Overall, improvement of nerve function at 12 months was seen in about 50% of patients in both groups. Analysis of subgroups according to nerve (ulnar and posterior tibial), duration of NFI, and sensory and motor function, also did not reveal any differences between the treatment and placebo groups. There was however, indication of less deterioration of nerve function in the prednisolone group. Finally, there was no difference in the occurrence of adverse events between both groups. The trial confirms current practice not to treat long-standing NFI with prednisolone. Spontaneous recovery of nerve function appears to be a common phenomenon in leprosy. Leprosy reactions and new NFI occurred in a third of the study group, emphasizing the need to keep patients under regular surveillance during MDT, and, where possible, after completion of MDT.</p