Boundary effects on non-equilibrium localized structures in spatially extended systems

A study of the effects of system boundaries on bistable front propagation in nonequilibrium reaction-diffusion systems is presented. Two model partial differential equations displaying bistable fronts, with distinct experimental motivations and mathematical structure, are examined in detail utilizing simulations and perturbation techniques. We see that propagating fronts in both models bounce, trap, pin, or oscillate at the boundary, contingent on the imposed boundary condition, initial front speed and distance from the boundary. The similarities in front boundary interactions in these two models is traced to the fact that they display the same front instability (Ising-Bloch bifurcation) that controls the speed of propagation. A simplified dynamical picture based on ordinary differential equations that captures the essential features of front motion described by the original partial differential equations, is derived and analyzed for both models. In addition to addressing experimentally important boundary effects, we establish the universality of the Ising-Bloch bifurcation. Useful analytical insights into perturbative analysis of reaction diffusion systems are also presented

Vacuum pyrolysed biochar for soil amendment

Biochar, a highly carbonaceous charred organic material obtained from biomass conversion can be deliberately applied as a conditioner/ amender in order to improve soil quality and associated environmental services. Napier grass (Pennisetum purpureum), a lignocellulosic biomass, can potentially be used to produce biochar. The aim of the present work is to manufacture, comprehensively characterize, and apply biochar obtained from the vacuum pyrolysis and investigate its potential for soil amendment. Biochar produced from Napier grass was characterized for its pH, electrical conductivity, soil water retention capacity, surface acidity and/or basicity, elemental composition, Infrared spectra, X-ray diffraction spectra, surface area, porosity, soil-water relation and morphological properties. Experiments on the methylene blue adsorption of the biochar indicated an equilibrium uptake capacity of 35 mg.g−1 and showed good agreement with the Langmuir-Freundlich model. Kinetic studies revealed Lagergren pseudo-first-order fit with intra-particle diffusion appearing to be one of the rate controlling mechanisms. Pot trials with Cicer grown in neutral and acidic soil amended with biochar validated that biochar augmented plant growth in terms of enhanced biomass weight and number of seed germinations. The entire investigation revealed that the properties of the produced biochar are in line with those necessary for it to act as a suitable agent for soil amendment

Cross-sectional study on accidental occupational exposures amongst urban slum-based private medical practitioners

Background:This cross-sectional, complete enumeration study was conducted in an urban slum to determine the frequency of occupational exposure of private medical practitioners to patient body fluids and the remedial measures adopted following such events and also to examine their high-risk practices, personal protective measures, immunisation and training status in relation to occupational exposures.Methods: After Institutional Ethics Committee approval, private medical practitioners practising for ≥ 1 year in the locality who gave written informed consent were interviewed in their own clinics using a pre-tested formatted questionnaire.Results: Of the 108 respondents interviewed, the majority were non-allopathic, male practitioners. The speciality-wise and gender-wise differences in training in occupational exposure were not significant (p=0.135). Prior to disposal, 10.18% cut needles while 26.85% disinfected needles with 1% hypochlorite solution (p=0.0001). 50.93% never bent or recapped needles (p=0.0008). Only 19.44% regularly used gloves while examining patients (p=0.0039). 41.66% were completely unimmunised against Hepatitis B (p=0.004), while only one female non-allopathic practitioner (0.92%) had taken complete immunisation against tetanus (p<0.05). Of the 7.41% respondents who had history of needle stick injuries, only one female non-allopathic practitioner had reported occupational exposure. Those unaware about the need for post-exposure prophylaxis for occupational exposure and that anti-retroviral therapy was part of post-exposure prophylaxis constituted 87.96% and 95.37%, respectively.Conclusions: Reporting of occupational exposure, complete immunisation against hepatitis B and tetanus and use of personal protection was inadequate. Specialised hands-on training ought to be an integral component of continuing medical education for private medical practitioners.

On the behaviour, mechanistic modelling and interaction of biochar and crop fertilizers in aqueous solutions

Although the benefits of applying biochar for the purposes of soil conditioning and crop productivity enhancement have been demonstrated, relatively few studies have elaborated on its causal mechanisms, especially on the biochar-fertilizer interaction. Thus, in the present study, the ex-situ adsorptive potential of base activated biochar (BAB) towards plant nutrient immobilization and removal from aqueous solutions was investigated. Napier grass (Pennisetum purpureum) was utilized as the precursor to prepare slow vacuum pyrolysed char and its affinity towards adsorption of urea was examined at various process conditions. Low sorption temperatures, moderate agitation speeds and high initial concentration were seen to favour greater urea uptake by BAB. The sorption was exothermic, physical, spontaneous and had a pseudo-second order kinetic fit. Both surface and intra-particle diffusion governed the removal and immobilization of urea. Furthermore, process mass transfer was limited by film diffusion of urea to the external surface of the BAB. Equilibrium studies suggested that Dubinin-Radushkevich is the most appropriate model to describe the urea-BAB behaviour with maximum uptake, estimated to be 1115 mg·g−1. Through such ex-situ analysis, it could be possible to have prior knowledge, quantification and differentiation of the potential of chars manufactured from various feedstocks. This could then be used as an effective screening step in designing appropriate biochar-fertilizer systems for soil conditioning and help reduce the time and effort spent otherwise in long-term field studies

Foraging behaviour of honeybees (Apis spp.) (Hymenoptera: Apidae) in hybrid seed production of Indian mustard (Brassica juncea)

Pollination of entomophilous crops by honeybees is considered as one of the effective and inexpensive method for improving the crop yield and its quality. In most of the crops, effective pollination is prerequisite for fruitful fertilisation. Hence, we investigated the differential foraging activity of honeybees in relation to aspects of crop management including sowing time and parental row ratio in the hybrid seed production of the first Indian mustard hybrid NRCHB Apis spp. (half of which being Apis dorsata) was the dominant pollinators in our study. The pollinator abundance was maximum in the forenoon in male line (19.1) and in the afternoon in female line (13.9). Pollen collectors (8.7) outnumbered the nectar collectors (7.2) in male line and the reverse in female line. Pollinator abundance decreased in rows distantly positioned from the male parent row. Air temperature was positively correlated (r = 0.631) and relative humidity negatively correlated (r = –0.736) with honeybee foraging. Warmer weather conditions during flowering period showed higher number of honeybee visiting the hybrid seed production plots. This study would help the seed producers to standardise the planting geometry and date of sowing to promote maximum pollinator abundance at peak flowering period resulting in higher hybrid seed yield

Measuring the health-related Sustainable Development Goals in 188 countries : a baseline analysis from the Global Burden of Disease Study 2015

Background In September, 2015, the UN General Assembly established the Sustainable Development Goals (SDGs). The SDGs specify 17 universal goals, 169 targets, and 230 indicators leading up to 2030. We provide an analysis of 33 health-related SDG indicators based on the Global Burden of Diseases, Injuries, and Risk Factors Study 2015 (GBD 2015). Methods We applied statistical methods to systematically compiled data to estimate the performance of 33 health-related SDG indicators for 188 countries from 1990 to 2015. We rescaled each indicator on a scale from 0 (worst observed value between 1990 and 2015) to 100 (best observed). Indices representing all 33 health-related SDG indicators (health-related SDG index), health-related SDG indicators included in the Millennium Development Goals (MDG index), and health-related indicators not included in the MDGs (non-MDG index) were computed as the geometric mean of the rescaled indicators by SDG target. We used spline regressions to examine the relations between the Socio-demographic Index (SDI, a summary measure based on average income per person, educational attainment, and total fertility rate) and each of the health-related SDG indicators and indices. Findings In 2015, the median health-related SDG index was 59.3 (95% uncertainty interval 56.8-61.8) and varied widely by country, ranging from 85.5 (84.2-86.5) in Iceland to 20.4 (15.4-24.9) in Central African Republic. SDI was a good predictor of the health-related SDG index (r(2) = 0.88) and the MDG index (r(2) = 0.2), whereas the non-MDG index had a weaker relation with SDI (r(2) = 0.79). Between 2000 and 2015, the health-related SDG index improved by a median of 7.9 (IQR 5.0-10.4), and gains on the MDG index (a median change of 10.0 [6.7-13.1]) exceeded that of the non-MDG index (a median change of 5.5 [2.1-8.9]). Since 2000, pronounced progress occurred for indicators such as met need with modern contraception, under-5 mortality, and neonatal mortality, as well as the indicator for universal health coverage tracer interventions. Moderate improvements were found for indicators such as HIV and tuberculosis incidence, minimal changes for hepatitis B incidence took place, and childhood overweight considerably worsened. Interpretation GBD provides an independent, comparable avenue for monitoring progress towards the health-related SDGs. Our analysis not only highlights the importance of income, education, and fertility as drivers of health improvement but also emphasises that investments in these areas alone will not be sufficient. Although considerable progress on the health-related MDG indicators has been made, these gains will need to be sustained and, in many cases, accelerated to achieve the ambitious SDG targets. The minimal improvement in or worsening of health-related indicators beyond the MDGs highlight the need for additional resources to effectively address the expanded scope of the health-related SDGs.Peer reviewe