304 research outputs found

    Challenges and strength of current industrial energy efficiency management practices in steam industries

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    Abstract: The aim of this study is to achieve greater output by examining the existing way of coordinating the determined attempts of Steam Industries in South Africa to successfully reach a sustainable industrial development by using energy source adequately in a more competent way. Furthermore into the study we look at obstacles that prevent and those that leads to maximum utilization of energy management measures and also highlights the effects of implementing cheap available energy source in South Africa. The investigation and analysis have shown that energy is not well managed in Steam Industries and that the use of energy is minimized and not fully utilized due to poor management and lack of knowledge. Another detection was that lack of government structured and strategic measures of implementing and motivating the use of energy effectively. The effective and rational use of available power by Steam Industries in South Africa is a key player in developing a sustainable industrial development. The use of energy efficiency management strategies has contributed an increase in economic and improve environmentally friendly in the industrial sector. The slow pace adoption of energy saving and cost effective management programmes are negatively impacting on the benefits to Steam Industries in South Africa. In conclusion the study finds that the economy can be boosted by implementing energy efficiency management programmes and environmentally friendly. These will also stabilize the negative impact of energy raising prices

    Effects of a fibrolytic enzyme and bacterial inoculants on the fermentation, chemical composition and aerobic stability of ensiled potato hash

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    The study was conducted to evaluate the effects of adding a fibrolytic enzyme in combination with bacterial inoculants on the fermentation, chemical composition and aerobic stability of ensiled potato hash (PH). Potato hash silage (PHS) was produced by mixing 800 g PH/kg and 200g wheat bran (WB)/kg. The mixture was ensiled with either no additive or enzyme Celluclast (low or high dose) or bacterial inoculants (Emsilage and Silosolve). These treatment combinations were produced: i) no additive (control); ii) Celluclast low dose (CLD); iii) Celluclast high dose (CHD); iv) Emsilage (EMS); v) CLD + EMS; vi) CHD + EMS; vii) Silosolve (SLS); viii) CLD + SLS; and ix) CHD + SLS. These treatments were ensiled in 81 x 1 L anaerobic jars for 90 days with nine replicates per treatment. Three samples per treatment were collected before ensiling and after 90 days’ ensiling, were analysed for fermentation characteristics and chemical composition. In addition, samples of day 90 were subjected to an aerobic stability test, where they were exposed for five days. Enzyme addition reduced fibre, thus making more sugar available for fermentation. The combination of CHD and EMS reduced silage pH, thus preserving the silage compared with other treatment combinations. Enzyme addition (used at low and high dose), and bacterial inoculants improved fermentation. Enzyme addition improved the chemical composition, but impaired the aerobic stability of PHS. Further work to test these findings on animal performance is warranted.Keywords: Deterioration, fibre, nutrients, pH, ruminant, water soluble carbohydrate

    Dual HLA B*42 and B*81-reactive T cell receptors recognize more diverse HIV-1 Gag escape variants

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    Closely related HLA alleles presenting similar HIV-1 epitopes can be associated with variable clinical outcome. Here the authors report their findings on CD8+ T cell responses to the HIV-1 Gag-p24 TL9 immunodominant epitope in the context of closely related protective and less protective HLA alleles, and their differential effect on viral contro

    Reliability and factor structure of the audit among male and female bar patrons in a rural area of South Africa

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    We assessed the reliability and dimensional structure of the Alcohol Use Disorders Identification Test (AUDIT) among bar patrons in a rural area of South Africa. In total, 406 bar patrons completed a questionnaire containing the AUDIT, and demographic and psychosocial measures. The participants consisted of 314 (77.3%) males and 92 (22.6%) females. Their combined mean age was 30.0 years (SD = 8.45). The data were analysed using Confirmatory Factor Analysis (CFA) and Cronbach’s alpha reliability analysis which were conducted separately for males and females. We found that Cronbach’s alpha for the AUDIT was 0.81 and 0.72 for the males and females, respectively. CFA supported a two-factor and three-factor model for the males but failed to support a one-factor, two-factor, or three-factor model for the females. The results suggest that the AUDIT is highly reliable, but that potential gender differences in its factor structure should be considered, particularly when applied in new contexts.Keywords: AUDIT; South Africa; Bar patron

    Gathering the evidence and identifying opportunities for future research in climate, heat and health in South Africa : the role of the South African Medical Research Council

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    Abstract: Background. A changing climate is likely to have widespread and varying impacts on ecosystems and human health. South Africa (SA) is particularly vulnerable to the impacts of climate change, given the projected increases in temperature, and changes in the amount and patterns of rainfall. Moreover, SA’s vulnerability is exacerbated by extreme inequality and poverty. To prepare for the impacts of climate change and to ensure timeous adaptation, a perspective is given on essential heat and health research in the country. Objectives. To gather studies conducted by the South African Medical Research Council (SAMRC)’s Environment and Health Research Unit (EHRU) to illustrate the range of possible research key areas in the climate, heat and health domain and to present future research priorities. Methods. Studies conducted by the SAMRC’s EHRU were gathered and used to illustrate the range of possible research key areas in the climate, heat and health domain. Using national and international published and grey literature, and tapping into institutional research experiences, an overview of research findings to date and future research priorities were developed. Results. Heat and health-related research has focussed on key settings, for example, schools, homes and outdoor work places, and vulnerable groups such as infants and children, the elderly and people with pre-existing diseases. The need to address basic needs and services provision was emphasised as an important priority. Conclusions. High and low temperatures in SA are already associated with mortality annually; these impacts are likely to increase with a changing climate. Critical cross-sectoral research will aid in understanding and preparing for temperature extremes in SA

    Prevalence and correlates of roll-your-own cigarette smoking among South African adults during 2010-2011 and 2017-2018

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    INTRODUCTION : The increasing use of roll-your own (RYO) cigarettes has been documented globally, but there are no recent data from South Africa, particularly among youths and low-income groups. We assessed changes in prevalence and correlates of RYO smoking among South African adults during 2010-2011 and 2017-2018, and explored expenditure differences between daily smokers of RYO and manufactured cigarettes. METHODS : Nationally representative data of South Africans aged ≥16 years used in this study were from the South African Social Attitudes Survey (SASAS) for 2010-2011 (n=6116), and 2017-2018 (n=5799). Current RYO cigarette use included daily and non-daily use. Annual expenditures were estimated based on typical usage patterns for daily users. Descriptive and multivariable analyses were performed using Stata Version 15 with the level of statistical significance set at p<0.05. RESULTS : The prevalence of ever RYO cigarette use increased from 6.5% (95% CI: 5.6-7.5) during 2010-2011, to 8.5% (95% CI: 7.0-10.0) during 2017-2018 (p=0.026). Current RYO cigarette use prevalence however remained largely unchanged when we compared 2010-2011 to 2017-2018 (5.2% vs 6.3%, p=0.544). During 2017-2018, current RYO cigarette use prevalence was highest among men (11.6%), those who self-identified as Coloreds (11.1%), people aged 25-34 years (7.8%), those with no schooling (7.5%), and those unemployed (9.8%). Annual expenditures associated with typical patterns of daily RYO cigarette smoking were substantially less than for smoking of manufactured cigarettes. CONCLUSIONS : The prevalence of ever RYO cigarette use increased between 2010-2011 and 2017-2018. Current RYO cigarette use during 2017-2018 was more prevalent among Coloreds, Black Africans, youths, those with lower education, and the unemployed. This study's findings highlight the need to harmonize taxation of cigarettes and RYO cigarettes, and to intensify implementation of evidence-based tobacco control and prevention interventions in South Africa.The African Capacity Building Foundation.http://www.tobaccoinduceddiseases.orghj2022School of Health Systems and Public Health (SHSPH

    Screening and managing a low-risk pregnant population using continuous-wave Doppler ultrasound in a low-income population: A cohort analytical study

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    Background. In South Africa (SA), the largest category of perinatal deaths is unexplained stillbirths. Two-thirds of these occur in the antenatal period and most fetuses are macerated, but at antenatal clinics the mothers were generally regarded as healthy, with low-risk pregnancies. Innovative methods are urgently required to detect fetuses at risk of stillbirth and manage the mothers appropriately.Objectives. To determine the prevalence of raised resistance indices (RIs) of the umbilical artery in a low-risk, low-income population and ascertain whether use of this information can prevent perinatal deaths.Methods. A descriptive study was performed in Mamelodi township, east of Pretoria, SA, on pregnant women attending antenatal clinics draining to two community health centres (CHCs). These women, classified as having low-risk pregnancies, were screened for placental insufficiency using a continuous-wave Doppler ultrasound apparatus (Umbiflow) between 28 and 32 weeks’ gestation. When a raised RI was detected, the mother was referred to a high-risk clinic and managed according to a standard protocol. A cohort analytical study compared women who attended antenatal care at the same clinics as the Umbiflow group but did not have an Umbiflow test with those who had an Umbiflow test. The outcomes of all the deliveries in Mamelodi were recorded. The prevalences of abnormal RIs, absent end-diastolic flow (AEDF), stillbirths and neonatal deaths were the main outcome measures.Results. An Umbiflow RI was performed in 2 868 women, and pregnancy outcome was available for 2 539 fetuses (88.5%); 297 fetuses (11.7%) were regarded as at high risk. AEDF was found in 1.5% of the population screened with an outcome. There were 29 perinatal deaths in the Umbiflow group (low risk n=18, high risk n=11). The perinatal mortality rate for 12 168 women attending the CHCs and the antenatal clinics draining to the CHCs who did not have an RI was 21.3/1 000 births, significantly higher than that in the Umbiflow group (11.4/1 000 births) (risk ratio 0.58, 95% confidence interval 0.42 - 0.81).Conclusions. The prevalence of AEDF in this low-risk population is ~10 times higher than that previously recorded. Use of the information prevented a number of perinatal deaths, most of which would have been macerated stillbirths. Screening a low-risk pregnant population using continuous-wave Doppler ultrasound may substantially reduce the prevalence of unexplained stillbirths in SA.

    CD8 lymphocytes mitigate HIV-1 persistence in lymph node follicular helper T cells during hyperacute-treated infection

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    HIV persistence in tissue sites despite ART is a major barrier to HIV cure. Detailed studies of HIV-infected cells and immune responses in native lymph node tissue environment is critical for gaining insight into immune mechanisms impacting HIV persistence and clearance in tissue sanctuary sites. We compared HIV persistence and HIV-specific T cell responses in lymph node biopsies obtained from 14 individuals who initiated therapy in Fiebig stages I/II, 5 persons treated in Fiebig stages III-V and 17 late treated individuals who initiated ART in Fiebig VI and beyond. Using multicolor immunofluorescence staining and in situ hybridization, we detect HIV RNA and/or protein in 12 of 14 Fiebig I/II treated persons on suppressive therapy for 1 to 55 months, and in late treated persons with persistent antigens. CXCR3(+) T follicular helper cells harbor the greatest amounts of gag mRNA transcripts. Notably, HIV-specific CD8(+) T cells responses are associated with lower HIV antigen burden, suggesting that these responses may contribute to HIV suppression in lymph nodes during therapy. These results reveal HIV persistence despite the initiation of ART in hyperacute infection and highlight the contribution of virus-specific responses to HIV suppression in tissue sanctuaries during suppressive ART

    Augmentation of HIV-specific T cell function by immediate treatment of hyperacute HIV-1 infection

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    Sustained viremia after acute HIV infection is associated with profound CD4+ T cell loss and exhaustion of HIV-specific CD8+ T cell responses. To determine the impact of combination antiretroviral therapy (cART) on these processes, we examined the evolution of immune responses in acutely infected individuals initiating treatment before peak viremia. Immediate treatment of Fiebig stages I and II infection led to a rapid decline in viral load and diminished magnitude of HIV-specific (tetramer+) CD8+ T cell responses compared to untreated donors. There was a strong positive correlation between cumulative viral antigen exposure before full cART-induced suppression and immune responses measured by MHC class I tetramers, IFN-Îł ELISPOT, and CD8+ T cell activation. HIV-specific CD8+ T responses of early treated individuals were characterized by increased CD127 and BCL-2 expression, greater in vitro IFN-Îł secretion, and enhanced differentiation into effector memory (Tem) cells. Transcriptional analysis of tetramer+ CD8+ T cells from treated persons revealed reduced expression of genes associated with activation and apoptosis, with concurrent up-regulation of prosurvival genes including BCL-2, AXL, and SRC. Early treatment also resulted in robust HIV-specific CD4+ T cell responses compared to untreated HIV-infected individuals. Our data show that limiting acute viremia results in enhanced functionality of HIV-specific CD4+ and CD8+ T cells, preserving key antiviral properties of these cells
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