Data on the association between exposure to environmental tobacco smoke (ETS) and Mycobacterium tuberculosis infection in children are limited.
To examine the dose-response effect of ETS exposure on ...the risk of M. tuberculosis infection in children in a high tuberculosis (TB) burden setting.
This cross-sectional study included healthy South African children from impoverished urban communities. Data were collected on household ETS and M. tuberculosis exposure, demographics, socio-economic and anthropometric data, M. tuberculosis infection, human immunodeficiency virus and TB disease status.
Among 196 children (median age 6.8 years, range 0.3-15.9), 97 (49.5%) were M. tuberculosis - i nfected (tuberculin skin test TST ≥ 10 mm) and 128 (65.3%) reported ETS exposure; of these, 81/128 (63.3%) were exposed to ≥ 2 household smokers. The presence of ≥ 2 household smokers was associated with M. tuberculosis infection in univariate analysis, irrespective of TST cut-off point. In analysis adjusting for M. tuberculosis exposure, socio-economic status, age and previous TB treatment, ETS exposure remained associated with M. tuberculosis infection. In univariate and multivariate analysis, pack-years of exposure were associated with risk of TB infection.
Exposure to ETS is associated with M. tuberculosis infection in children after adjustment for multiple variables, with a dose-response relationship between the degree of ETS exposure and risk of infection. Public health interventions to reduce exposure to tobacco smoke among children in high TB burden settings are urgently needed.
•Presentation of unique results from 6 and 8 year CA field trials in South Africa.•In clay soils, SOC increased from 54.9 to 57.6 t ha−1 under reduced tillage.•In sandy soils, SOC changes were mostly ...influenced by climatic conditions.•The profitability of CA depended on soil conditions.•Seasonal weather variation was the main determinant of profitability, irrespective of management.
Conservation agriculture (CA), with reduced tillage, permanent soil cover and diversified cropping systems, is advocated in southern Africa to improve soil quality, reduce input costs and mitigate climate-induced risks. However, improvements in terms of yield and soil organic carbon (SOC) under CA are slow and variable and many small-scale farmers are unable to buffer themselves against potential short-term financial losses. In this study we examined the effects of CA-related management practices on SOC sequestration and productivity at two medium-term sites on a sandy soil (eight year trial) and clay soil (six years) in maize producing areas of South Africa. Using field data, current input costs and market prices for crops, we calculated the gross margin for each system. Treatments compared conventional ploughing under maize monoculture with reduced tillage, intercropping and crop rotation. On the clay soil, SOC was increased under reduced tillage (57.6 t C ha−1) compared to conventional tillage (54.9 t C ha−1) while there was no difference for the sandy soil (19.7 t C ha−1 average across treatments). Profitability was most strongly influenced by seasonal rainfall, but was higher on the sandy soil than the clay soil, with an average gross margin of R11,344 ha−1 and R5,686 ha−1, respectively. This study has demonstrated that while certain CA practices can create site-specific benefits for farmers, it is highly dependent on local weather and soil conditions. For the clay soil an additional payment scheme would be required to reward farmers in southern Africa for C-sequestration to make CA profitable and achieve increased C-mitigation through soil sequestration.
Polystoma vernoni (Polystomatidae) is a new species in the urinary bladder of Ptychadena oxyrhynchus in KwaZulu-Natal province, South Africa. Ptychadena is a true African species and the 49 currently ...known species in Africa harbour 11 polystome parasites. Ptychadena oxyrhynchus has an extensive distribution through Africa and harbours Polystoma prudhoei in West Africa. This new parasite differs significantly from P. prudhoei. The new species is distinguished by its long body relative to its haptor length, its unique shape and its ratio of marginal hooklets. In a sample of 13 frogs, 53.8% were infected with up to 18 parasites per host (mean intensity 4.86).
Specimens from across the range of the Hyperolius nasutus species group were sequenced for two mitochondrial genes and one nuclear gene. Advertisement calls were recorded from the same specimens ...where possible, and morphological characters were compared. Bayesian inference and maximum likelihood produced a tree indicating 16 clades. The clades show little or no overlap in combinations of 16S sequence difference, shared tyr haplotypes, advertisement call parameters, snout profiles and webbing. On the basis of these data we recognise H. acuticeps, H. adspersus, H. benguellensis, H. dartevellei, H. igbettensis, H. nasutus, H. nasicus, H. poweri, H. viridis and describe six new species: Hyperolius friedemanni sp. nov. Mercurio & Rödel, Hyperolius howelli sp. nov. Du Preez & Channing, Hyperolius inyangae sp. nov. Channing, Hyperolious jacobseni sp. nov. Channing, Hyperolius rwandae sp. nov. Dehling, Sinsch, R6del & Channing, and Hyperolius lupiroensis sp. nov. Channing. Hyperolius lamottei is confirmed to be outside the H. nasutus group clade. Hyperolius granulatus, H. oxyrhynchus, H. punctulatus and H. sagitta are assigned as junior synonyms. As our results are based on a small number of specimens, these hypotheses await testing with larger sample sizes and more characters. A species distribution model suggests where outlier populations might be found.
Polystoma nacialtuneli n. sp. is described from the urinary bladder of the eastern spadefoot, Pelobates syriacus from Turkey. This is the fifth polystome species known from Turkey and the third ...species in Pelobates. We show that this new parasite species can be distinguished from other polystome species in the area by a combination of characteristics, including parasite size and the shape and size of the hamuli. Polystoma pelobatis from Pelobates cultripes has a pair of well-developed hamuli, while P. fuscus from Pe. fuscus characteristically has a pair of underdeveloped hamuli barely larger than the marginal hooklets. Polystoma nacialtuneli n. sp. has well-developed hamuli that vary significantly in shape. Phylogenetic relationships of P. nacialtuneli n. sp. within Polystoma, supplemented with molecular divergences estimated from internal transcribed spacer 1 (ITS1) sequences, indicate that they are well separated from their closest relatives, i.e. P. fuscus and P. pelobatis from Pe. fuscus and Pe. cultripes, respectively.
Background
Musculoskeletal (MSK) injuries are one of the leading causes of disability worldwide. Despite improvements in trauma-related morbidity and mortality in high-income countries over recent ...years, outcomes following MSK injuries in low- and middle-income countries, such as South Africa (SA), have not. Despite governmental recognition that this is required, funding and research into this significant health burden are limited within SA. This study aims to identify research priorities within MSK trauma care using a consensus-based approach amongst MSK healthcare practitioners within SA.
Method
Members from the Orthopaedic Research Collaboration in Africa (ORCA), based in SA, collaborated using a two round modified Delphi technique to form a consensus on research priorities within orthopaedic trauma care. Members involved in the process were orthopaedic healthcare practitioners within SA.
Results
Participants from the ORCA network, working within SA, scored research priorities across two Delphi rounds from low to high priority. We have published the overall top 10 research priorities for this Delphi process. Questions were focused on two broad groups—clinical effectiveness in trauma care and general trauma public health care. Both groups were represented by the top two priorities, with the highest ranked question regarding the overall impact of trauma in SA and the second regarding the clinical treatment of open fractures.
Conclusion
This study has defined research priorities within orthopaedic trauma in South Africa. Our vision is that by establishing consensus on these research priorities, policy and research funding will be directed into these areas. This should ultimately improve musculoskeletal trauma care across South Africa and its significant health and socioeconomic impacts.
The triazine herbicide atrazine has been hypothesized to disrupt sexual development in frogs by up-regulating aromatase activity, resulting in greater estradiol (E2) concentrations and causing ...feminization in males. The goal of this study was to collect native ranid frogs from atrazine-exposed ponds and determine whether relationships exist between measured atrazine concentrations and the gonadosomatic index (GSI), plasma concentrations of testosterone (T), E2 or 11-ketotestosterone (KT), or with aromatase activity. In the summer of 2002 and 2003, adult and juvenile green frogs (
Rana clamitans), bullfrogs (
R. catesbeiana) and Northern leopard frogs (
R. pipiens) were collected from areas with extensive corn cultivation and areas where there was little agricultural activity in south-central Michigan. Atrazine concentrations were below the limit of quantification at non-agricultural sites. Atrazine concentrations did not exceed 2
μg/L at most agricultural sites, but a concentration of 250
μg atrazine/L was measured in one sample from one site in 2002. Plasma steroid concentrations varied among locations. Aromatase activity was measurable in less than 11% of testes in adult males, and in less than 4% of testes in juvenile males. Median aromatase activities in ovaries of adult females ranged from 3 to 245
pmol/h/mg protein, and maximum activities were 2.5-fold greater in juveniles than in adults. Atrazine concentrations were not significantly correlated with any of the parameters measured in this study. These results indicate that atrazine does not up-regulate aromatase in green frogs in the wild, and does not appear to affect plasma steroid hormone concentrations.
Polystoma okomuensis is described as a new species of the Polystomatidae parasitic in the urinary bladder of Boulenger's striped frog Phlyctimantis boulengeri in the Okomu National Park, Edo State, ...Nigeria. Although other African polystomes have been reported from Nigeria, this is the first to be described from the country and the first from Phlyctimantis. It is distinguished from other African Polystoma species by a combination of characters, including the body size, size and shape of the hamuli, size and shape of marginal hooklets and intestinal location. Phlyctimantis boulengeri was found to be infected in two of four seasonal lakes where specimens were caught with prevalences and mean intensities ranging from 14.3 to 22% and 1.0 to 1.5, respectively. Of the total number of 45 frogs examined, the prevalence was 15.6% and mean intensity 1.4.
In South Africa canola (Brassica napus L.) is cultivated in rotation with wheat under winter rainfall in the Western Cape Province, primarily for seed to make oil. Expansion of the crop to the other ...8 provinces is proposed to reduce shortages of locally produced plant oils. At the same time, canola can serve as a rotational crop for wheat in these summer rainfall provinces. In central Free State, information on evapotranspiration and various water use indicators for canola as influenced by sustained deficit irrigation and plant density is lacking. An experiment with a line source sprinkler irrigation system was therefore conducted, comprising of full irrigation as a control with 4 sustained deficit irrigation levels (mean reduction in irrigation depth per event of 67%, 52%, 34% and 19%) and 5 plant densities (25, 50, 75, 100 and 125 plants·m−2). Mean seasonal maximum evapotranspiration amounted to 429 mm across plant densities. Plant density did not significantly influence seasonal evapotranspiration. Reducing the irrigation depth per event by more than 20% decreased seasonal evapotranspiration by a mean 3.5 mm per percentage increase in irrigation depth. A maximum biomass water productivity of 22 kg·ha−1·mm−1 was measured with full irrigation and a plant density of 75 plants·m−2. Seed water productivity amounted to a high of 11 kg·ha−1·mm−1 with full irrigation and a plant density of 25 plants·m−2. A percentage reduction in irrigation depth and increase in plant density above 25 plants·m−2 will reduce seed water productivity by 0.071 and 0.033 kg·ha−1·mm−1, respectively. Sustained deficit irrigation increased water use efficiency by a mean 0.5% per percentage reduction in irrigation depth per event.
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