Operational assessment of point-of-care diagnostics in rural primary healthcare clinics of KwaZulu-Natal, South Africa: a cross-sectional survey.

BACKGROUND: The World Health Organization (WHO) called for new clinical diagnostic for settings with limited access to laboratory services. Access to diagnostic testing may not be uniform in rural settings, which may result in poor access to essential healthcare services. The aim of this study is to determine the availability, current usage, and need for point-of-care (POC) diagnostic tests among rural primary healthcare (PHC) clinics in South Africa's KwaZulu-Natal (KZN) province. METHODS: We used the KZN's Department of Health (DoH) clinic classification to identify the 232 rural PHC clinics in KZN, South Africa. We then randomly sampled 100 of 232 rural PHC clinics. Selected health clinics were surveyed between April to August 2015 to obtain clinic-level data for health-worker volume and to determine the accessibility, availability, usage and need for POC tests. Professional healthcare workers responsible for POC testing at each clinic were interviewed to assess the awareness of POC testing. Data were survey weighted and analysed using Stata 13. RESULTS: Among 100 rural clinics, the average number of patients seen per week was 2865 ± 2231 (range 374-11,731). The average number of POC tests available and in use was 6.3 (CI: 6.2-6.5) out of a potential of 51 tests. The following POC tests were universally available in all rural clinics: urine total protein, urine leukocytes, urine nitrate, urine pregnancy, HIV antibody and blood glucose test. The average number of desired POC diagnostic tests reported by the clinical staff was estimated at 15 (CI: 13-17) per clinic. The most requested POC tests reported were serum creatinine (37%), CD4 count (37%), cholesterol (32%), tuberculosis (31%), and HIV viral load (23%). CONCLUSION: Several POC tests are widely available and in use at rural PHC clinics in South Africa's KZN province. However, healthcare workers have requested additional POC tests to improve detection and management of priority disease conditions. TRIAL REGISTRATION: Clinical Trials.gov Identifier: NCT02692274

Microplastic ingestion in fish larvae in the western English Channel

Microplastics have been documented in marine environments worldwide, where they pose a potential risk to biota. Environmental interactions between microplastics and lower trophic organisms are poorly understood. Coastal shelf seas are rich in productivity but also experience high levels of microplastic pollution. In these habitats, fish have an important ecological and economic role. In their early life stages, planktonic fish larvae are vulnerable to pollution, environmental stress and predation. Here we assess the occurrence of microplastic ingestion in wild fish larvae. Fish larvae and water samples were taken across three sites (10, 19 and 35 km from shore) in the western English Channel from April to June 2016. We identified 2.9% of fish larvae (n = 347) had ingested microplastics, of which 66% were blue fibres; ingested microfibers closely resembled those identified within water samples. With distance from the coast, larval fish density increased significantly (P < 0.05), while waterborne microplastic concentrations (P < 0.01) and incidence of ingestion decreased. This study provides baseline ecological data illustrating the correlation between waterborne microplastics and the incidence of ingestion in fish larvae

An assessment of the ecosystem services of marine zooplankton and the key threats to their provision

Zooplankton are a key group of organisms at the base of the marine food web and are fundamental to providing a broad range of societal and economic benefits which have previously remained poorly defined. This research addresses this knowledge gap through the provision of a first full assessment of zooplankton ecosystem services and disservices. Anthropogenic stressors such as microplastic pollution, climate change, and fisheries, could negatively affect the marine ecosystem services provided to humans and therefore have a negative impact on human well-being through reduction in food security, livelihoods, income, and good health. Deploying a mixed methodology approach including a semi-systematic literature review and ecological impact assessment, we provide novel evidence of the effects of microplastic pollution (high and low concentrations), fisheries, and climate change on the ecosystem services of three important zooplankton groups (copepods, jellyfish, and krill). We show that the majority of impacts on ecosystem services are negative, with the exception of climate change on jellyfish ecosystem services. Climate change and high microplastic concentration are evidenced to have the most substantial negative impacts on copepods and krill, with accompanying implications for the ecosystem services of climate regulation, water conditions, other materials, science, and entertainment. High microplastic concentration also depressed ecosystem service provision for jellyfish, impacting the services of genetic materials, climate regulation, water conditions, education, and entertainment. Fisheries are also evidenced to have negative impacts on all three zooplankton groups. In the case of jellyfish, climate change is evidenced to have a positive impact on the group's ecosystem service provision in every category except experiential experiences, which is inversely related to increasing population, owing to their negative perception due to sting injuries. The evidence presented in this study shows that by maintaining sustainable fisheries, reducing plastic pollution, and minimising climate change, we will be actively investing in the current and future provision of marine ecosystem services and the human well-being benefits that they provide

A reference relative time-scale as an alternative to chronological age for cohorts with long follow-up

Background: Epidemiologists have debated the appropriate time-scale for cohort survival studies; chronological age or time-on-study being two such time-scales. Importantly, assessment of risk factors may depend on the choice of time-scale. Recently, chronological or attained age has gained support but a case can be made for a ‘reference relative time-scale’ as an alternative which circumvents difficulties that arise with this and other scales. The reference relative time of an individual participant is the integral of a reference population hazard function between time of entry and time of exit of the individual. The objective here is to describe the reference relative time-scale, illustrate its use, make comparison with attained age by simulation and explain its relationship to modern and traditional epidemiologic methods. Results: A comparison was made between two models; a stratified Cox model with age as the time-scale versus an un-stratified Cox model using the reference relative time-scale. The illustrative comparison used a UK cohort of cotton workers, with differing ages at entry to the study, with accrual over a time period and with long follow-up. Additionally, exponential and Weibull models were fitted since the reference relative time-scale analysis need not be restricted to the Cox model. A simulation study showed that analysis using the reference relative time-scale and analysis using chronological age had very similar power to detect a significant risk factor and both were equally unbiased. Further, the analysis using the reference relative time-scale supported fully-parametric survival modelling and allowed percentile predictions and mortality curves to be constructed. Conclusions: The reference relative time-scale was a viable alternative to chronological age, led to simplification of the modelling process and possessed the defined features of a good time-scale as defined in reliability theory. The reference relative time-scale has several interpretations and provides a unifying concept that links contemporary approaches in survival and reliability analysis to the traditional epidemiologic methods of Poisson regression and standardised mortality ratios. The community of practitioners has not previously made this connection

Microwave enhanced ion-cut silicon layer transfer

Microwave heating has been used to decrease the time required for exfoliation of thin single-crystalline silicon layers onto insulator substrates using ion-cut processing. Samples exfoliated in a 2.45 GHz, 1300 W cavity applicator microwave system saw a decrease in incubation times as compared to conventional anneal processes. Rutherford backscattering spectrometry, cross sectional scanning electron microscopy, cross sectional transmission electron microscopy, and selective aperture electron diffraction were used to determine the transferred layer thickness and crystalline quality. The surface quality was determined by atomic force microscopy. Hall measurements were used to determine electrical properties as a function of radiation repair anneal times. Results of physical and electrical characterizations demonstrate that the end products of microwave enhanced ion-cut processing do not appreciably differ from those using more traditional means of exfoliation. © 2007 American Institute of Physics

Production of Androgens by Microbial Transformation of Progesterone in Vitro: A Model for Androgen Production in Rivers Receiving Paper Mill Effluent

We have previously documented the presence of progesterone and androstenedione in the water column and bottom sediments of the Fenholloway River, Taylor County, Florida. This river receives paper mill effluent and contains masculinized female mosquitofish. We hypothesized that plant sterols (e.g., β-sitosterol) derived from the pulping of pine trees are transformed by bacteria into progesterone and subsequently into 17α-hydroxyprogesterone, androstenedione, and other androgens. In this study, we demonstrate that these same androgens can be produced in vitro from the bacterium Mycobacterium smegmatis. In a second part to this study, we reextracted and reanalyzed the sediment from the Fenholloway River and verified the presence of androstadienedione, a Δ1 steroid with androgen activity

The capitalist labour process : concepts and connections

The Conference of Socialist Economists (CSE) and Capital & Class were central in creating the conditions for a labour process debate. However, while the journal has continued to publish some articles on labour process issues, the debate has become associated primarily with the annual International Labour Process Conference. This article explores shifts in the nature and focus of debates, emphasizing continuity between the traditions as well as change. By contrasting early attempts in the journal to uncover 'immanent laws' of the capitalist labour process to more recent writings on core theory, contemporary trends in labour power and capitalist political economy are outlined and evaluated

Optimisation of microfluidic polymerase chain reaction devices

The invention and development of Polymerase Chain Reaction (PCR) technology have revolutionised molecular biology and molecular diagnostics. There is an urgent need to optimise the performance of these devices while reducing the total construction and operation costs. This study proposes a CFD-enabled optimisation methodology for continuous flow (CF) PCR devices with serpentine-channel structure, which enables the optimisation of DNA amplification efficiency and pressure drop to be explored while varying the width (W) and height (H) of the microfluidic (μ) channel. This is achieved by using a surrogate-enabled optimisation approach accounting for the geometrical features of a μCFPCR device by performing a series of simulations using COMSOL Multiphysics 5.4®. The values of the objectives are extracted from the CFD solutions, and the response surfaces are created using polyharmonic splines. Genetic algorithms are then used to locate the optimum design parameters. The results indicate that there is the possibility of improving the DNA concentration and the pressure drop in a PCR cycle by ~2.1 % ([W, H] = [400 μm, 50 μm]) and ~95.2 % ([W, H] = [400 μm, 80 μm]) respectively, by modifying its geometry.</jats:p

Impact of polyester and cotton microfibers on growth and sublethal biomarkers in juvenile mussels

Anthropogenic microfibres are a prevalent, persistent and globally distributed form of marine debris. Evidence of microfibre ingestion has been demonstrated in a range of organisms, including Mytilus spp. (mussels), but the extent of any impacts on these organisms are poorly understood. This study investigates, for the first time, the effect of exposing juvenile mussels to polyester and cotton microfibres at environmentally relevant concentrations (both current and predicted future scenarios) over a chronic timescale (94 days). Sublethal biomarkers included growth rate, respiration rate and clearance rate. Mussels were exposed to polyester (median length 149 µm) and cotton (median length 132 µm) microfibres in three treatments: polyester (~ 8 fibres L−1), polyester (~ 80 fibres L−1) and cotton (~ 80 fibres L−1). Mussels exposed to 80 polyester or cotton microfibres L−1 exhibited a decrease in growth rate of 35.6% (polyester) and 18.7% (cotton), with mussels exposed to ~ 80 polyester microfibres L−1 having a significantly lower growth rate than the control population (P < 0.05). This study demonstrates that polyester microfibres have the potential to adversely impact upon mussel growth rates in realistic future scenarios, which may have compounding effects throughout the marine ecosystem and implications for commercial viability