112 research outputs found

    Emissions and Deforestation Associated with Household Energy Use: A Case of the Thulamela Local Municipality, South Africa

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    Fuel wood is regarded as a major source of energy around the world, particularly in developing nations forming part of the energy mix. Most rural communities around the world, consider forests as the repository of stored energy. The study focused on the role of fuel wood in deforestation and the emissions of greenhouse gases (GHG) in the Thulamela local municipality in South Africa. Information regarding the fuel wood consumption was collected during a manual field survey of 200 households in four villages in the municipality using questionnaires and interviews. The carbon dioxide (CO2) emissions were calculated using the generic formula and the emission factors were applied in calculating the emissions of carbon monoxide (CO), nitrogen oxide (NO) and methane (CH4). According to our results, the combined greenhouse gases emitted in the four studied areas are CO2 14.91 Kg, CO 0.000349 Kg, NO 0.00548 Kg and CH4 0.01222 Kg. Calculated vegetation change using the Normalized Difference Vegetation Index (NDVI) for a 5year interval (2007-2012) indicated that a change percentage of 56.23 in the four villages

    Optimization of Base Station Location in 3G Networks using Mads and Fuzzy C-means

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    Distribution of Base Transceiver Stations (BTS) with an aim of maintaining high Quality of Service and coverage is important to mobile operators. Rapid expansion of telecommunication industry results in stiff competition among service providers which in turn leads to greater focus on quality of services delivered. Increase in number of mobile phone usage has also led to unprecedented network expansion. Coupled to these challenges is rapid change in telecommunication technology from 2G to 4G in a short space of time. A combination of MADS and FUZZY C- MEANS is used to aid in planning Base Station Transceivers (BTS) location efficiently in order to curb capital and maintenance costs. Keywords: BTS placement, MADS, Fuzzy C-Mean

    Analysis of Electromagnetic Field Radiation from a Rectangular Cavity-Backed Slot Antenna Using ADI-FDTD Method

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    In this paper, a rectangular Cavity Backed Slot Antenna (CBSA) Model excited by a probe is investigated. The analysis is carried out using the Alternating Direction Implicit - Finite Difference Time Domain (ADI-FDTD) Method which is applied to investigate its characteristics in terms of radiation patterns and power. This is because the method is capable of providing a more accurate definition of the electromagnetic fields within the rectangular apertures, while eliminating the Courant-Friedrich-Levy (CFL) stability condition which is present in the regular Finite Difference Time Domain (FDTD) method. A cavity-backed slot antenna structure with dimensions of 14cm×22cm×30cm is analyzed with the slot and aperture measurements done at 3GHz. Results showing current distribution on the material surrounding the apertures are presented and a discussion on the physical aspects of the aperture radiation phenomenon is also presented. Keywords: cavity-backed slot antenna (CBSA), aperture radiation, alternating direction implicit-finite difference time domain (ADI-FDTD) metho

    Determinants of human papillomavirus (HPV) vaccine hesitancy in sub-Saharan Africa: A systematic review

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    Background: Vaccine hesitancy is a major public health issue that has negatively impacted vaccine uptake in sub-Saharan Africa (SSA). The reasons why individuals hesitate or refuse to vaccinate are variable and factors contributing to vaccine hesitancy are not well outlined. This review, therefore, aims to identify and describe the determinants of HPV vaccine hesitancy in SSA.Methods: A systematic search was conducted across four electronic databases (PubMed, Scopus, CINAHL and Web of Science) from 2007 until October 2021 and updated in January 2022. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses, 13 studies were eligible and were included in the analysis. Data extraction and synthesis were guided by the Health Belief Model. Quality assessment was performed using the NIH and CASP quality assessment tools.Results: The most frequently reported factors influencing HPV vaccine hesitancy included concerns about side effects and infertility; limited knowledge of HPV vaccine, HPV infection, and cervical cancer; lack of awareness of vaccination opportunities; mistrust of health workers, health authorities, and new vaccines; influence by caregivers, peers, community members or respected members of the society and religious and cultural factors. Other factors included accessibility issues (roads in poor condition, transport costs), adolescent absenteeism on vaccination day and dropping out of school.Conclusion: To reduce hesitancy and improve HPV vaccination coverage, vaccination programs need to develop and implement inclusive and context-specific strategies to enhance vaccine confidence, alleviate concerns, engage, and provide appropriate information to stakeholders involved in HPV vaccination, and dispel rumours and misinformation. The capacity of teachers and healthcare providers must be reinforced to equip them with knowledge about HPV vaccines, improve their interpersonal communication skills so that they can be better advocates for the vaccine within their communities. &nbsp

    Relapse and post-discharge body composition of children treated for acute malnutrition using a simplified, combined protocol: A nested cohort from the ComPAS RCT

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    INTRODUCTION: Severe and moderate acute malnutrition (SAM and MAM) affect more than 50 million children worldwide yet 80% of these children do not access care. The Combined Protocol for Acute Malnutrition Study (ComPAS) trial assessed the effectiveness of a simplified, combined SAM/MAM protocol for children aged 6-59 months and found non-inferior recovery compared to standard care. To further inform policy, this study assessed post-discharge outcomes of children treated with this novel protocol in Kenya. METHODS: Six 'combined' protocol clinics treated SAM and MAM children using an optimised mid-upper arm circumference (MUAC)-based dose of ready-to-use therapeutic food (RUTF). Six 'standard care' clinics treated SAM with weight-based RUTF rations; MAM with ready-to-use supplementary food (RUSF). Four months post-discharge, we assessed anthropometry, recent history of illness, and body composition by bioelectrical impedance analysis. Data was analysed using multivariable linear regression, adjusted for age, sex and allowing for clustering by clinic. RESULTS: We sampled 850 children (median age 18 months, IQR 15-23); 44% of the original trial sample in Kenya. Children treated with the combined protocol had similar anthropometry, fat-free mass, fat mass, skinfold thickness z-scores, and frequency of common illnesses 4 months post-discharge compared the standard protocol. Mean subscapular skinfold z-scores were close to the global norm (standard care: 0.24; combined 0.27). There was no significant difference in odds of relapse between protocols (SAM, 3% vs 3%, OR = 1.0 p = 0.75; MAM, 10% vs 12%, OR = 0.90 p = 0.34). CONCLUSIONS: Despite the lower dosage of RUTF for most SAM children in the combined protocol, their anthropometry and relapse rates at 4 months post-discharge were similar to standard care. MAM children treated with RUTF had similar body composition to those treated with RUSF and neither group exhibited excess adiposity. These results add further evidence that a combined protocol is as effective as standard care with no evidence of adverse effects post-discharge. A simplified, combined approach could treat more children, stretch existing resources further, and contribute to achieving Sustainable Development Goal Two

    Small-scale agricultural grassland management can affect soil fungal community structure as much as continental scale geographic patterns

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    A European transect was established, ranging from Sweden to the Azores, to determine the relative influence of geographic factors and agricultural small-scale management on the grassland soil microbiome. Within each of five countries (factor ‘Country’), which maximized a range of geographic factors, two differing growth condition regions (factor ‘GCR’) were selected: a favorable region with conditions allowing for high plant biomass production and a contrasting less favorable region with a markedly lower potential. Within each region, grasslands of contrasting management intensities (factor ‘MI’) were defined: intensive and extensive, from which soil samples were collected. Across the transect, ‘MI’ was a strong differentiator of fungal community structure, having a comparable effect to continental scale geographic factors (‘Country’). ‘MI’ was also a highly significant driver of bacterial community structure, but ‘Country’ was clearly the stronger driver. For both, ‘GCR’ was the weakest driver. Also at the regional level, strong effects of MI occurred on various measures of the soil microbiome (i.e. OTU richness, management-associated indicator OTUs), though the effects were largely regional-specific. Our results illustrate the decisive influence of grassland MI on soil microbial community structure, over both regional and continental scales, and, thus, highlight the importance of preserving rare extensive grasslands

    Vaccines in the fight against antimicrobial resistance – perspectives from South Africa

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    Antimicrobial resistance (AMR), in which microbes adapt to and resist current therapies, is a well-recognised global problem that threatens to reverse gains made by modern medicine in the last decades. AMR is a complex issue; however, at its core, it is driven by the overuse and inappropriate use of antimicrobials. Socioeconomic factors have been identified as significant contributors to the emergence and exacerbation of AMR, especially in populations facing inadequate access to healthcare, poor sanitation services and high morbidity and mortality rates. Weak healthcare systems and water, sanitation and hygiene have been highlighted as fundamental risk factors for AMR emergence and transmission. Behavioural factors, such as purchasing antibiotics without a prescription from a registered healthcare professional, not completing the prescribed course or overly prolonged courses of antibiotics, using antibiotics to treat viral infections, lack of access to quality antibiotics, and the proliferation of substandard or falsified (SF) drugs, have also been identified as significant contributors to AMR. Low- and middle-income countries have a higher incidence of antibiotics being dispensed without a prescription than higher-income countries

    Community-Led Total Sanitation: A Mixed-Methods Systematic Review of Evidence and Its Quality

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    Background: Community-led total sanitation (CLTS) is a widely applied rural behavior change approach for ending open defecation. However, evidence of its impact is unclear. Objectives: We conducted a systematic review of journal-published and gray literature to a) assess evidence quality, b) summarize CLTS impacts, and c) identify factors affecting implementation and effectiveness. Methods: Eligible studies were systematically screened and selected for analysis from searches of seven databases and 16 websites. We developed a framework to appraise literature quality. We qualitatively analyzed factors enabling or constraining CLTS, and summarized results from quantitative evaluations. Discussion: We included 200 studies (14 quantitative evaluations, 29 qualitative studies, and 157 case studies). Journal-published literature was generally of higher quality than gray literature. Fourteen quantitative evaluations reported decreases in open defecation, but did not corroborate the widespread claims of open defecation–free (ODF) villages found in case studies. Over one-fourth of the literature overstated conclusions, attributing outcomes and impacts to interventions without an appropriate study design. We identified 43 implementation- and community-related factors reportedly affecting CLTS. This analysis revealed the importance of adaptability, structured posttriggering activities, appropriate community selection, and further research on combining and sequencing CLTS with other interventions. Conclusions: The evidence base on CLTS effectiveness available to practitioners, policy makers, and program managers to inform their actions is weak. Our results highlight the need for more rigorous research on CLTS impacts as well as applied research initiatives that bring researchers and practitioners together to address implementation challenges to improve rural sanitation efforts

    Controlled Human Malaria Infection in Semi-Immune Kenyan Adults (CHMI-SIKA): a study protocol to investigate in vivo Plasmodium falciparum malaria parasite growth in the context of pre-existing immunity [version 2; peer review: 2 approved]

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    Malaria remains a major public health burden despite approval for implementation of a partially effective pre-erythrocytic malaria vaccine. There is an urgent need to accelerate development of a more effective multi-stage vaccine. Adults in malaria endemic areas may have substantial immunity provided by responses to the blood stages of malaria parasites, but field trials conducted on several blood-stage vaccines have not shown high levels of efficacy. We will use the controlled human malaria infection (CHMI) models with malaria-exposed volunteers to identify correlations between immune responses and parasite growth rates in vivo. Immune responses more strongly associated with control of parasite growth should be prioritized to accelerate malaria vaccine development. We aim to recruit up to 200 healthy adult volunteers from areas of differing malaria transmission in Kenya, and after confirming their health status through clinical examination and routine haematology and biochemistry, we will comprehensively characterize immunity to malaria using >100 blood-stage antigens. We will administer 3,200 aseptic, purified, cryopreserved Plasmodium falciparum sporozoites (PfSPZ Challenge) by direct venous inoculation. Serial quantitative polymerase chain reaction to measure parasite growth rate in vivo will be undertaken. Clinical and laboratory monitoring will be undertaken to ensure volunteer safety. In addition, we will also explore the perceptions and experiences of volunteers and other stakeholders in participating in a malaria volunteer infection study. Serum, plasma, peripheral blood mononuclear cells and whole blood will be stored to allow a comprehensive assessment of adaptive and innate host immunity. We will use CHMI in semi-immune adult volunteers to relate parasite growth outcomes with antibody responses and other markers of host immunity. / Registration: ClinicalTrials.gov identifier NCT02739763
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