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The demand for innovative and cost-effective in-situ consolidation technologies in soft clay stimulated the effort to employ electrokinetic phenomena in soils under an electric field. This work explains the principles of electrophoresis and electroosmosis in soft clay under an electric field and discusses the implacations of these results for field implementation of the technique. The experimental work reported here was carried out to shed light on the principles by considering various influencing factors. The results show that there is a threshold current (about 15 mA) for electroosmosis and electrophoresis in soft clay. Below the threshold current, electrophoresis plays a major role and is accompanied by weak electroosmosis. The particle size, dry density, and boundary rise height of electrophoretic soil in anode chamber are mainly affected by soil moisture content, electrode in electrolyte length, and bottom of electrode to soil surface distance. The closer the soil moisture content is to the average value of the liquid limit and plastic limit, the denser the electrophoretic soil will be. Above the threshold current, almost only electroosmosis occurs. The greater the current, the greater the electroosmosis. In practical engineering application, electrodes are usually directly inserted into the soft clay. This results in the current usually being much greater than the threshold current, meaning the electrophoretic phenomenon in the soil can be negligible.

Objectives: This study investigated the long-term outcomes 1-year after undertaking an Internet-based cognitive behavioural therapy (ICBT) for tinnitus distress in a US population. Secondary aims were to identify the effects on additional difficulties associate with tinnitus and any unwanted events related to ICBT for tinnitus. Methods: A repeated-measures design with 4 time points was used. Participants previously undertaking two randomized ICBT efficacy trials for tinnitus in the US were invited to participate. Of the 200 invited, 132 (66 %) completed the 1-year follow-up questionnaire. The primary outcome was a change in tinnitus distress from baseline at one year post-intervention, as assessed by the Tinnitus Functional Index. Secondary assessment measures were included for anxiety, depression, insomnia, hearing disability, hyperacusis, tinnitus cognitions and health-related quality of life. Results: Undertaking ICBT for tinnitus led to significant improvements 1-year post-intervention for tinnitus severity, with a large effect size (d = 1.06; CI: 0.80 to 1.32). Medium effects were found for anxiety (d = 0.54; CI: 0.29 to 0.79), depression (d = 0.46; CI: 0.21 to 0.70), insomnia (d = 0.47; CI: 0.22 to 0.72), and tinnitus cognitions (d = 0.43, CI: 0.18 to 0.68). Small effect sizes were found for hearing disability, hyperacusis and health-related quality of life. Adverse events related to the intervention were only reported by 1 participant. Conclusions: The benefits of audiologist-guided ICBT for tinnitus and tinnitus-related difficulties were maintained 1-year post-intervention with very few adverse events reported. Ways of disseminate evidence-based easily accessible interventions to the general population with bothersome tinnitus should be sought.

Foliar exposure to dust-borne potentially toxic elements (PTEs) is often overlooked in chromium (Cr) mining and industrial regions. A comparative analysis of unwashed (UL) and washed leaves (WL) was conducted to investigate the contribution of dust to Al, As, Cd, Co, Cr (total and hexavalent Cr (Cr(VI)), Cu, Hg, Mn, Mo, Ni, Pb, Sb, V and Zn contents of leafy vegetables and medicinal plants from chromitite outcrops and Cr mining-smelting localities in Sekhukhuneland, South Africa. For leafy vegetables, health risks were estimated for all PTEs except Al and Hg, for which weekly intakes were calculated. Mean total Cr levels in UL and WL exceeded the international permissible levels by up to 22- and 9-fold, respectively, linking foliar Cr contamination to dust deposition and a lesser extent, accumulation in tissue. The most hazardous Cr species, Cr(VI) was detected in soil-plant (UL) systems of outcrops and polluted sites. Unwashed leaves had higher mean concentrations of 71% of the assessed PTEs (except Cd, Co, Hg and Sb) than WL, indicating dust as a source of PTEs. Only Cr had a Hazard Quotient (HQ) > 1 (UL). The HQ of Cr and Co contributed the most to the Hazard Index of UL (1.70) and WL (1.39). Carcinogenic risk was > 1 × 10‒4 for Cr(VI) (UL) and > 1 × 10‒3 for total Cr (UL > WL) and Ni (WL > UL). Estimated weekly intake of Hg (WL > UL) exceeded Provisional Tolerable Weekly Intake. Lifelong consumption of unwashed and even washed leafy vegetables might be hazardous in the study locality. Regular monitoring of PTE levels in the dust-soil-plant system is necessary for Cr mining-smelting regions.

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal).Please note that this retraction notice was updated in November 2022, as follows: to provide details of the corrected and updated version of the article that has been published.This article has been retracted at the request of the Corresponding Author, Sutapa Adhikari, who regrets to inform us that two wrong pieces of information were used: (1) The oral Reference Dose used for aluminium and mercury in this study (2) The Hazard Quotient and Hazard Index of elements were calculated based on WHO recommended daily dietary intake amounts of fruit and vegetables, rather than the average daily vegetable intake quantity for South African population which is significantly lower. Consequently, the calculated risk outcome was magnified considerably, leading to erroneous conclusions.The Corresponding Author takes full responsibility for these errors and offers her sincere apologies.The corrected and updated version of this article is available here:Sutapa Adhikari, João Marcelo-Silva, Johan Paul Beukes, Pieter Gideon van Zyl, Yolindi Coetsee, Ricart Barend Boneschans, Stefan John Siebert, Contamination of useful plant leaves with chromium and other potentially toxic elements and associated health risks in a polluted mining-smelting region of South Africa, Environmental Advances, Volume 9, 2022, 100301, https://doi.org/10.1016/j.envadv.2022.100301.

Methicillin-resistant Staphylococcus aureus (MRSA) is resistant to beta-lactam antibiotics, while some strains are multi-drug resistant and may produce disease-causing toxins. Drug resistant strains are often responsible for chronic, persistent and recurrent infections, which pose a challenge for healthcare practitioners. Our study aimed to determine the prevalence of nasal MRSA and methicillin-resistant coagulase-negative staphylococci (MRCoNS) among school children in the Mariental community, southern Namibia. This was a cross-sectional study in the Mariental District. Nasal specimens (swabs) were collected from 272 randomly selected learners aged 6–14 years attending school in the area during the months of March, September and October 2016. Isolation and identification of staphylococci were performed using standard microbiological methods. Methicillin-resistant isolates were identified by their resistance towards cefoxitin (30 µg) using the Kirby-Bauer disk diffusion assay. Enterotoxin production among multi-drug resistant MRSA isolates was detected with a SET-RPLA toxin detection kit. Methicillin-resistant S. aureus was isolated from 48 (17.6%) learners and MRCoNS from only seven (2.6%). Methicillin-resistant S. aureus colonization was significantly higher (P = 0.003) in the age group 11–14 years than in the group 6–10 years. Among the 433 staphylococcal isolates screened for cefoxitin resistance, 51 (11.8%) were MRSA and seven (1.6%) were MRCoNS. From the 51 MRSA isolates, 22 (43.1%) were multi-drug resistant of which six were enterotoxigenic. This is the first report on MRSA and MRCoNS among school children in Namibia. The presence of multi-drug resistant and potentially virulent staphylococci among school children in Mariental, Namibia, is of concern. Self-infection by these bacteria poses various health risks for the children. It is recommended that school health programmes improve current hygiene practices. Frequent handwashing can prevent staphylococcal disease and spread of resistant strains among learners and the wider community.

A potential hazard associated with ferrochrome production is the unintentional generation of Cr(VI) in the off-gas dusts produced during smelting. Cr(VI) is a well-known environmental toxin and genotoxic carcinogen. Although Cr(VI) has been identified in baghouse dusts associated with submerged-arc furnaces, its occurrence in DC-arc-furnace dusts has not been previously investigated. In this study, we report the bulk composition and phase make-up, as well as the surface and bulk speciation of Cr and Fe of dusts generated during smelting of chromite ore under basic slag conditions in a pilot-scale DC arc smelter. Dusts are captured from both within the DC furnace as well as along the off-gas handling stream, after passing through the afterburner. The dusts primarily comprise feed material (chromite, flux, reductant), aerosolized slag, and glassy spherules, interpreted as off-gas condensates. Dusts collected from within the furnace, known as freeboard dusts, are dominated by feed materials, with elevated amounts of flux (lime) and lesser amounts of slag and spherules. In contrast, spherules dominate dusts collected along the off-gas handling stream by dust separators that capture the increasingly fine-grained fraction of dust, with the highest proportion of spherules occurring in baghouse dusts. Chromite is the primary host of Cr in all dust samples, whereas the spherules have low Cr contents. Cr(VI) was identified by X-ray photoelectron spectroscopy in the surfaces of dust collected from all parts of the smelter system considered, including from the furnace freeboard, despite the overall reducing conditions present therein. Cr(VI) concentrations are sufficiently high in dusts collected from the off-gas handling stream (post-afterburner, cyclone, and baghouse) to be detected in the bulk dust samples by X-ray absorption spectroscopy. The higher concentration of Cr(VI) in the finer-grained off-gas dusts, especially the baghouse dusts, is consistent with the increased abundance of spherules, the major Cr(VI)-hosting phase, in these samples. Fe is similarly more oxidized in dusts collected down the off-gas handling stream compared to dusts collected from within the furnace, which are dominated by Fe(II). Fe(III) hosted by FeOOH is predominate in dusts collected from all locations along the off-gas handling stream. These results demonstrate that there is sufficient oxygen ingress and sufficiently high temperatures in the closed DC furnace for Cr(VI) to be generated in the freeboard off-gas dusts. Cr(VI) is associated with the finest grained fraction of dusts, underlining the importance of ensuring the continual improvement of dust-capture systems, especially in terms of their ability to target increasingly finer fractions of dust.

Background: Internet-based cognitive behavioral therapy (ICBT) for tinnitus is an evidence-based intervention. The components of ICBT for tinnitus have, however, not been dismantled and thus the effectiveness of the different therapeutic components is unknown. It is, furthermore, not known if heterogeneous tinnitus subgroups respond differently to ICBT. Aims: This dismantling study aimed to explore the contribution of applied relaxation within ICBT for reducing tinnitus distress and comorbidities associated with tinnitus. A secondary aim was to assess whether outcomes varied for three tinnitus subgroups, namely those with significant tinnitus severity, those with low tinnitus severity, and those with significant depression. Methods: A parallel randomized controlled trial design (n = 126) was used to compare audiologist-guided applied relaxation with the full ICBT intervention. Recruitment was online and via the intervention platform. Assessments were completed at four-time points including a 2-month follow-up period. The primary outcome was tinnitus severity as measured by the Tinnitus Functional Index. Secondary outcomes were included for anxiety, depression, insomnia, negative tinnitus cognitions, health-related quality of life, hearing disability, and hyperacusis. Treatment engagement variables including the number of logins, number of modules opened, and the number of messages sent. Both an intention-to-treat analysis and completer's only analysis were undertaken. Results: Engagement was low which compromised results as the full intervention was undertaken by few participants. Both the ICBT and applied relaxation resulted in large reduction of tinnitus severity (within-group effect sizes d = 0.87 and 0.68, respectively for completers only analysis), which were maintained, or further improved at follow-up. These reductions in tinnitus distress were greater for the ICBT group, with a small effect size differences (between-group d = 0.15 in favor of ICBT for completers only analysis). Tinnitus distress decreased the most at post-intervention for those with significant depression at baseline. Both ICBT and applied relaxation contributed to significant reductions on most secondary outcome measures, with no group differences, except for a greater reduction of hyperacusis in the ICBT group. Conclusion: Due to poor compliance partly attributed to the COVID-19 pandemic results were compromised. Further studies employing strategies to improve compliance and engagement are required. The intervention's effectiveness increased with initial level of tinnitus distress; those with the highest scores at intake experienced the most substantial changes on the outcome measures. This may suggest tailoring of interventions according to tinnitus severity. Larger samples are needed to confirm this.

Summary: Background: A rapid, blood-based triage test that allows targeted investigation for tuberculosis at the point of care could shorten the time to tuberculosis treatment and reduce mortality. We aimed to test the performance of a host blood transcriptomic signature (RISK11) in diagnosing tuberculosis and predicting progression to active pulmonary disease (prognosis) in people with HIV in a community setting. Methods: In this prospective diagnostic and prognostic accuracy study, adults (aged 18–59 years) with HIV were recruited from five communities in South Africa. Individuals with a history of tuberculosis or household exposure to multidrug-resistant tuberculosis within the past 3 years, comorbid risk factors for tuberculosis, or any condition that would interfere with the study were excluded. RISK11 status was assessed at baseline by real-time PCR; participants and study staff were masked to the result. Participants underwent active surveillance for microbiologically confirmed tuberculosis by providing spontaneously expectorated sputum samples at baseline, if symptomatic during 15 months of follow-up, and at 15 months (the end of the study). The coprimary outcomes were the prevalence and cumulative incidence of tuberculosis disease confirmed by a positive Xpert MTB/RIF, Xpert Ultra, or Mycobacteria Growth Indicator Tube culture, or a combination of such, on at least two separate sputum samples collected within any 30-day period. Findings: Between March 22, 2017, and May 15, 2018, 963 participants were assessed for eligibility and 861 were enrolled. Among 820 participants with valid RISK11 results, eight (1%) had prevalent tuberculosis at baseline: seven (2·5%; 95% CI 1·2–5·0) of 285 RISK11-positive participants and one (0·2%; 0·0–1·1) of 535 RISK11-negative participants. The relative risk (RR) of prevalent tuberculosis was 13·1 times (95% CI 2·1–81·6) greater in RISK11-positive participants than in RISK11-negative participants. RISK11 had a diagnostic area under the receiver operating characteristic curve (AUC) of 88·2% (95% CI 77·6–96·7), and a sensitivity of 87·5% (58·3–100·0) and specificity of 65·8% (62·5–69·0) at a predefined score threshold (60%). Of those with RISK11 results, eight had primary endpoint incident tuberculosis during 15 months of follow-up. Tuberculosis incidence was 2·5 per 100 person-years (95% CI 0·7–4·4) in the RISK11-positive group and 0·2 per 100 person-years (0·0–0·5) in the RISK11-negative group. The probability of primary endpoint incident tuberculosis was greater in the RISK11-positive group than in the RISK11-negative group (cumulative incidence ratio 16·0 [95% CI 2·0–129·5]). RISK11 had a prognostic AUC of 80·0% (95% CI 70·6–86·9), and a sensitivity of 88·6% (43·5–98·7) and a specificity of 68·9% (65·3–72·3) for incident tuberculosis at the 60% threshold. Interpretation: RISK11 identified prevalent tuberculosis and predicted risk of progression to incident tuberculosis within 15 months in ambulant people living with HIV. RISK11's performance approached, but did not meet, WHO's target product profile benchmarks for screening and prognostic tests for tuberculosis. Funding: Bill & Melinda Gates Foundation and the South African Medical Research Council.

The process of species description is not random, and understanding the factors that influence when a species is first described (the date of first description, DoFD) allows us to target environments and/or species' traits to increase our knowledge of diversity. Such studies typically correlate species traits (e.g. maximum size, occupational depth) against DoFD, forgetting that species are not statistically independent of each other, owing to the inheritance of shared characteristics. A recent study of extant fishes by Costello et al. (2015) identified depth and geographic range size as the most important (of many) predictors of the DoFD, implying that newly described species will likely occupy restricted areas and occur deep in the water column. However, these authors failed to accommodate for “identity by descent” in their analyses. We correct that oversight here, and conclude that while the adjustments strengthen the associations between the different predictors and the DoFD, the overall affects are minimal and they do not materially change Costello et al.’s (2015) conclusions. This is briefly discussed.

First study of phytosynthesis of TiO2 NPs using the leaf (KL), pod (KP), seed (KS) and seed shell (KSS) extracts of kola nut tree (Cola nitida) is herein reported. The TiO2 NPs were characterized and evaluated for their antimicrobial, dye degradation, antioxidant and anticoagulant activities. The nearly spherical-shaped particles had λmax of 272.5–275.0 nm with size range of 25.00–191.41 nm. FTIR analysis displayed prominent peaks at 3446.79, 1639.49 and 1382.96 cm−1, indicating the involvement of phenolic compounds and proteins in the phytosynthesis of TiO2 NPs. Both SAED and XRD showed bioformation of crystalline anatase TiO2 NPs which inhibited multidrug-drug resistant bacteria and toxigenic fungi. The catalytic activities of the particles were profound, with degradation of malachite green by 83.48–86.28 % without exposure to UV-irradiation, scavenging of DPPH and H2O2by 51.19–60.08 %, and 78.45–99.23 % respectively. The particles as well prevented the coagulation of human blood. In addition to the antimicrobial and dye-degrading activities, we report for the first time the H2O2 scavenging and anticoagulant activities of TiO2 NPs, showing that the particles can be useful for catalytic and biomedical applications.

The dairy cow model ‘Molly’ is a mixed discrete event-continuous system model that simulates feeding, metabolism and lactation of dairy cows. Decades of model development have resulted in a valuable tool in dairy science. Due to the deprecation of the ACSL (Advanced Continuous Simulation Language) programming language, Molly has been translated into C++. This paper describes the translation process and discusses the advantages of the new implementation, one of which is the ability to run Molly within RStudio, a popular integrated development environment (IDE) for data science.

Background: Namibia experienced a large measles outbreak starting in 2009, with 38% of reported cases in adults, including women of reproductive age. Population immunity was assessed among pregnant women to determine whether immunization activities were needed in adults to achieve measles elimination in Namibia. Methods: A total of 1708 and 2040 specimens sampled from Namibian pregnant women aged 15–44 years who were included in the 2008 and 2010 National HIV Sentinel Survey, respectively, were tested for measles immunoglobulin G antibody. The proportion of women seropositive overall and by 5-year age strata was determined, and factors associated with seropositivity were analyzed by logistic regression, including age, facility type, gravidity, HIV status, and urban/rural setting. Seropositivity in 2008 versus 2010 was compared. Results: In both analysis years, measles seropositivity was lower in 15–19-year-olds (77%) and 20–24-year-olds (85–87%) and higher in 25–44-year-olds (90–94%) (2008, p

Background: The level of rubella susceptibility among women of reproductive age in Namibia is unknown. Documenting the risk of rubella will help estimate the potential burden of disease in Namibian women and the risk of congenital rubella syndrome (CRS) in infants, and will guide strategies for the introduction of rubella vaccine. Methods: A total of 2044 serum samples from pregnant Namibian women aged 15–44 years were tested for rubella immunoglobulin G antibody; the samples were obtained during the 2010 National HIV Sentinel Survey. The proportion of women seropositive for rubella was determined by 5-year age strata, and factors associated with seropositivity were analyzed by logistic regression, including age, gravidity, HIV status, facility type, and urban/rural status. Results: Overall rubella seroprevalence was 85% (95% confidence interval (CI) 83–86%). Seroprevalence varied by age group (83–90%) and health district (71–100%). In the multivariable model, women from urban residences had higher odds of seropositivity as compared to women from rural residences (odds ratio 1.40, 95% CI 1.09–1.81). Conclusions: In the absence of a routine rubella immunization program, the high level of rubella seropositivity suggests rubella virus transmission in Namibia, yet 15% of pregnant Namibian women remain susceptible to rubella. The introduction of rubella vaccine will help reduce the risk of rubella in pregnant women and CRS in infants.

Few existing studies illuminate the operation of the carbon cycle before the rise of atmospheric oxygen circa 2400 million years ago. Stable carbon isotopic measurements of shallow stromatolitic carbonates (~0 [parts per thousand] VPDB) and basinal carbonate minerals (-6 [parts per thousand]) in iron formation have been used to infer a strong isotopic depth gradient in Archean ocean basins. From new diamond drill cores obtained by the Agouron Drilling Project from the Griqualand West structural basin in the Northern Cape Province, South Africa, we present [delta C-13] data from carbonates and organic matter that offer fresh insights into the Late Archean carbon cycle. Three drill cores cover the development, progradation, and ultimate demise (by drowning) of the Campbellrand carbonate platform (ca. 2590-2500 Ma); one captures the platform top shallow marine and intertidal paleoenvironments, the other two run through slope and basinal sections deposited adjacent to the platform margin, increasing in water depth (likely to >1 km). Both shallow and deep-water carbonates precipitated on the seafloor consistently show [delta C-13] values around -0.5 [parts per thousand], incompatible with a strong Late Archean isotopic depth gradient. A mathematical model suggests that these isotopic data are consistent with a reduced biological pump, increased dissolved inorganic carbon in seawater due to higher atmospheric [P-CO2], or both. Certain horizons do show distinct isotopic variability. Such areas are commonly shaly, and they tend to be organic and/or iron rich. Strong C-isotopic variations occur on a cm scale and most likely stem from diagenetic remineralization of organic matter. In sediment-starved areas where iron formation developed, siderite tends to be [C-13]-depleted, sometimes by as much as -14 [parts per thousand]. These observations suggest a carbon cycle in which iron respiration played a conspicuous role. Carbon isotope ratios from organic matter in shales are commonly >1 [parts per thousand] lighter than stratigraphically contiguous carbonates, but there is no clear water depth trend in the organic carbon isotopic data. Taken as a whole, the [delta C-13] of organic matter can be explained by several non-unique sets of processes, including different autotrophic mechanisms of carbon fixation, heterotrophic recycling (including fermentation and methanotrophy), and post-depositional diagenesis. The most striking feature is the occurrence of organic [delta C-13] values <-40 [parts per thousand], a feature that appears to be commonplace in Late Archean successions. Framed in the context of carbon cycle isotopic mass balance, both organic and carbonate carbon isotopic data suggest that the proportion of carbon buried as organic matter was not radically different before the appearance of free environmental oxygen., Earth and Planetary Sciences, Organismic and Evolutionary Biology

The dairy cow model 'Molly' is a mixed discrete event-continuous system model that simulates feeding, metabolism and lactation of dairy cows. Decades of model development have resulted in a valuable tool in dairy science. Due to the deprecation of the ACSL (Advanced Continuous Simulation Language) programming language, Molly has been translated into C++. This paper describes the translation process and discusses the advantages of the new implementation, one of which is the ability to run Molly within RStudio, a popular integrated development environment (IDE) for data science.

An efficient dairy system, that implemented a combination of nitrogen (N) leaching mitigation strategies including lower N fertilizer input, standing cows off pasture for part of the day in autumn and winter (stand-off), and importing limited amounts of low protein supplements was evaluated over four consecutive years of a farmlet study. This efficient system consistently demonstrated a lower measured annual N leaching of 40 to 50% compared with a baseline system representing current practice with no mitigations. To maximize return from this system fewer cows but of higher genetic merit were used resulting in an average decrease in milk production of 2% and operating profit by 5% compared with the baseline system. The magnitude of the N leaching reduction from mitigation strategies was predicted in pre-trial modelling. Using similar mechanistic models in a post-trial study, we were able to satisfactorily predict the trends in the observed N leaching data over the four years. This enabled us to use the calibrated models to explore the contributions of the different mitigation strategies to the overall leaching reduction in the efficient system. In one of the years half of the leaching reduction was achieved by the 'input' component of the strategy (less feed N flowing through the herd from lower fertilizer use, less grass grown, and low-protein supplement use), while the other half was achieved by the stand-off strategy. However, these contributions are determined by the weather of a particular year. We estimate that on average stand-off would contribute 60% and 'input' 40% to the reduction. The implication is that farmers facing nutrient loss limitations have some current and some future technologies available to them for meeting these limitations. A shift towards the mitigations described here can result in a downward trend in their own N-loss metrics. The challenge will be to negate any reductions in production and profit, and remain competitive., (Copyright © 2017 Elsevier B.V. All rights reserved.)