Council for Scientific and Industrial Research, South Africa
Recent publications
Improper selection of laser powder bed fusion (LPBF) process parameters tends to result in poor quality parts which imposes limitations with respect to the mechanical performance due to process induced defects. To address this LPBF processing challenge, this study employs a hybrid optimisation technique which combines artificial neural network (ANN) and response surface methodology (RSM) models. The models were employed for predicting the microstructural properties (porosity, microhardness and amount of martensite phase composition) and mechanical characteristic (wear resistance) of LPBF manufactured maraging steel 1.2709 parts as a function of a combination of process parameters (scan speed, laser power and hatch spacing). Both ANN and RSM models had a high tracking ability. However, ANN showed better prediction accuracy than RSM. The most desirable optimal LPBF processing parameters for minimum wear volume and porosity while maintaining maximum microhardness and martensite phase composition were found at volumetric energy density (VED) of 77 J/mm3 (laser power = 165 W, scan speed = 784 mm/s and hatch spacing = 91 μm). Optimal quality properties predicted by the RSM and ANN models were consistent with confirmatory experiment results.
Background: Although tuberculosis (TB) symptoms have limited sensitivity they remain an important entry point into the TB care cascade. Objectives: To investigate self-reported healthcare seeking for TB symptoms in participants in a community-based survey. Methods: We compared reasons for not seeking care in participants reporting ≥1 of four TB screening symptoms (cough, weight loss, night sweats, fever) in the first South African national TB prevalence survey (2017-2019). We used logistic regression analyses to identify sociodemographic and clinical characteristics associated with healthcare seeking. Results: 5,168/35,191 (14.7%) survey participants reported TB symptoms and 3,442/5168 had not sought healthcare. 2,064/3,442(60.0%) participants intended to seek care, 912 (26.5%) regarded symptoms as benign, 399 (11.6%) reported access barriers(distance and cost), 36 (1.0%) took other medications and 20(0.6%) reported health system barriers. Of the 57/98 symptomatic participants diagnosed with bacteriologically confirmed TB who had not sought care: 38(66.7%) intended to do so, 8(14.0%) regarded symptoms as benign, and 6(10.5%) reported access barriers. Among these 98, those with unknown HIV status(OR 0.16 95% CI 0.03-0.82), p = 0.03 and those who smoked tobacco products(OR 0.39, 95% CI 0.17-0.89, p = 0.03) were significantly less likely to seek care. Conclusions: People with TB symptoms delayed seeking healthcare, many regarded symptoms as benign while others faced access barriers. Those with unknown HIV status were significantly less likely to seek care. Strengthening community-based TB awareness and screening programmes together with self-screening models could increase awareness of the significance of TB symptoms and contribute to improving healthcare seeking and enable many people with TB to enter the TB care cascade.
Woody plant encroachment (WPE) has been found to alter ecosystem functioning and services in savannas. In rain-limited savannas, increasing woody cover can reduce streamflow and groundwater by altering evapotranspiration rates and rainfall partitioning , but the ecological relevance of this impact is not well known. This study quantified the altered partitioning of rainfall by two woody plant structural types (fine-and broad-leaved trees) across a gradient of encroachment in a semi-arid savanna in South Africa. Averaged across both plant functional types, loss of rainfall through canopy interception and subsequent evaporation roughly doubled (from 20.5% to 43.6% of total rainfall) with a roughly 13-fold increase in woody cover (from 2.4 to 31.4 m 2 /ha tree basal cover). Spatial partitioning changes comprised fourfold increases in stem-flow (from 0.8% to 3.9% of total rainfall) and a decline in throughfall proportion of about two-fifths (from 80.2% to 47.3% of total rainfall). Changes in partitioning were dependent on plant functional type; rainfall interception by the fine-leaved multi-stemmed shrub Dichrostachys cinerea was almost double that of the broad-leaved tree Terminalia sericea at the highest levels of woody encroachment (i.e., 49.7% vs. 29.1% of total rainfall intercepted at tree basal area of 31.4 m 2 /ha). Partitioning was also dependent on rainfall characteristics, with the proportion of rainfall intercepted inversely related to rainfall event size and intensity. Therefore, increasing tree cover in African grassy ecosystems reduces the amount of canopy throughfall, especially beneath canopies of fine-leaved species in smaller rainfall events. Rainfall interception traits may thus confer a selective advantage, especially for fine-leaved woody plant species in semi-arid savannas. K E Y W O R D S functional traits, rainfall interception, stemflow, throughfall, woody plant encroachment
Atmospheric water harvesting (AWH) has consistently emerged as a possible source of fresh water, especially in regions where water and energy are scarce. Harvesting water from ambient air has the potential to be largely powered by renewable energy sources. Renewable energy has demonstrated a greater potential to produce water in arid regions using adsorption-based atmospheric water harvesting (ABAWH). Adsorbent is the only component in the ABAWH process that converts ambient air or moisture to water. In this direction, metal–organic frameworks (MOFs) have recently emerged as effective AWH adsorbents. The chapter focuses on the development of MOF-based adsorbents with excellent adsorption performance. Various parameters, such as adsorption kinetics, climatic conditions, and adsorption–desorption rate, have been covered in this chapter. This chapter also looks at the current advancements in AWH technologies and achievements. It is expected that this chapter will provide the reader with challenges that have been identified that retard the potential practical application of MOFs in AWH technology.
Polymeric Membranes, as a thin layer barrier for various size differential separation, are usually integrated with chemical and biological treatment of wastewater settings. Membrane filtration (MF) technology is very effective for heavy metal and metalloid removal from wastewater that contains a higher concentration of pollutants. MF and ultrafiltration (UF) membranes are generally used for the filtration of water effluent. Moreover the suitable alteration of polymeric membranes by incorporation of carbon based and metal nanoparticles resulting in highly engineered polymeric nanocomposite membranes put forward great benefits such as high strength, stability, resistivity better permeability and antimicrobial and antifouling properties. The resultant water from these membrane processes may be used for diverse reuse applications after disinfection. Researchers are exploring membrane-based, deionization, and nanotechnology-inspired approaches for converting raw or effluent water fit for specific purposes and minimization of pollution load. We quite often gather information regarding the advantages and disadvantages of available technologies for water remediation, and along with recent progress, this chapter also contains the developmental history, current status, future prospects, and significance of exploring and utilizing polymeric nanocomposite membranes in this domain.
Background: Hypertension is the second leading risk factor for death in South Africa, and rates have steadily increased since the end of Apartheid. Research on the determinants of hypertension in South Africa has received considerable attention due to South Africa's rapid urbanization and epidemiological transition. However, scant work has been conducted to investigate how various segments of the Black South African population experience this transition. Identifying the correlates of hypertension in this population is critical to the development of policies and targeted interventions to strengthen equitable public health efforts. Methods: This analysis explores the relationship between individual and area-level socioeconomic status and hypertension prevalence, awareness, treatment, and control within a sample of 7,303 Black South Africans in three municipalities of the uMgungundlovu district in KwaZulu-Natal province: the Msunduzi, uMshwathi, and Mkhambat-hini. Cross-sectional data were collected on participants from February 2017 to February 2018. Individual-level socioeconomic status was measured by employment status and educational attainment. Ward-level area deprivation was operationalized by the most recent (2011 and 2001) South African Multidimensional Poverty Index scores. Covariates included age, sex, BMI, and diabetes diagnosis. Results: The prevalence of hypertension in the sample was 44.4% (n = 3,240). Of those, 2,324 were aware of their diagnosis, 1,928 were receiving treatment, and 1,051 had their hypertension controlled. Educational attainment was negatively associated with hypertension prevalence and positively associated with its control. Employment status was negatively associated with hypertension control. Black South Africans living in more deprived wards had higher odds of being hypertensive and lower odds of having their hypertension controlled. Those residing in wards that became more deprived from 2001 to 2011 had higher odds of being aware of their hypertension, yet lower odds of receiving treatment for it. Conclusions: Results from this study can assist policymakers and practitioners in identifying groups within the Black South African population that should be prioritized for public health interventions. Black South Africans who have and continue to face barriers to care, including those with low educational attainment or living in deprived wards had worse hypertension outcomes. Potential interventions include community-based programs that deliver medication to households, workplaces, or community centers.
It is critical that coating’s microstructural characteristics are designed to meet its wear-resistance functional requirement. To the best of our knowledge, no study had related carbide dissolution ratio (CDR) in laser deposited Inconel 625 composite coating and its microstructural parameters to its wear performance. This study explores how laser processing and materials parameters influence CDR, microhardness (MH) and wear resistance (measured in terms of volume of materials loss: VML) of fibre-laser deposited composite coatings by employing response surface methodology (RSM). The nature of inter-relationship between the CDR, coating’s microstructural parameters (average mean free path and size of retained particles, and MH) as well as VML was explored to determine appropriate process and materials parameters to optimise wear resistance of the coatings. CDR increases with laser energy density while MH and wear resistance increase with laser energy density up to a threshold of 19.70J/mm². Above the energy density threshold, MH and wear resistance reduce. Inconel 625 content varies directly with CDR and VML while it has an indirect relationship with MH. The shielding gas flow rates have no effect on micro-hardness whereas it varies indirectly with CDR and VML. A fully consolidated coating characterised with uniformly distributed retained reinforcement’s particle size of 40 μm; mean free path of 30 μm within the Inconel 625 matrix; MH = 852 HV0.5; and CDR = 77.08% has the most desirable wear resistance (VML = 9.42mm³) when processed with laser energy density (19.70 J/mm²), Inconel content (70wt%) and shielding gas flow rates (6.00 l/min). This study provides new insight, for coating manufacturers, on how CDR and microstructural parameters can be manipulated as laser process and materials variables are altered in designing most desirable wear resistant composite coating.
Diagnostic accuracy studies in pulmonary tuberculosis (PTB) are complicated by the lack of a perfect reference standard. This limitation can be handled using latent class analysis (LCA), assuming independence between diagnostic test results conditional on the true unobserved PTB status. Test results could remain dependent, however, e.g. with diagnostic tests based on a similar biological basis. If ignored, this gives misleading inferences. Our secondary analysis of data collected during the first year (May 2018 -May 2019) of a community-based multi-morbidity screening program conducted in the rural uMkhanyakude district of KwaZulu Natal, South Africa, used Bayesian LCA. Residents of the catchment area, aged ≥15 years and eligible for microbiological testing, were analyzed. Probit regression methods for dependent binary data sequentially regressed each binary test outcome on other observed test results, measured covariates and the true unobserved PTB status. Unknown model parameters were assigned Gaussian priors to evaluate overall PTB prevalence and diagnostic accuracy of 6 tests used to screen for PTB: any TB symptom, radiologist conclusion, Computer Aided Detection for TB version 5 (CAD4TBv5≥53), CAD4TBv6≥53, Xpert Ultra (excluding trace) and culture. Before the application of our proposed model, we evaluated its performance using a previously published childhood pulmonary TB (CPTB) dataset. Standard LCA assuming conditional independence yielded an unrealistic prevalence estimate of 18.6% which was not resolved by accounting for conditional dependence among the true PTB cases only. Allowing, also, for conditional dependence among the true non-PTB cases produced a 1.1% plausible prevalence. After incorporating age, sex, and HIV status in the analysis, we obtained 0.9% (95% CrI: 0.6, 1.3) overall prevalence. Males had higher PTB prevalence compared to females (1.2% vs. 0.8%). Similarly, HIV+ had a higher PTB prevalence compared to HIV- (1.3% vs. 0.8%). The overall sensitivity for Xpert Ultra (excluding trace) and culture were 62.2% (95% CrI: 48.7, 74.4) and 75.9% (95% CrI: 61.9, 89.2), respectively. Any chest X-ray abnormality, CAD4TBv5≥53 and CAD4TBv6≥53 had similar overall sensitivity. Up to 73.3% (95% CrI: 61.4, 83.4) of all true PTB cases did not report TB symptoms. Our flexible modelling approach yields plausible, easy-to-interpret estimates of sensitivity, specificity and PTB prevalence under more realistic assumptions. Failure to fully account for diagnostic test dependence can yield misleading inferences.
Background: Gallbladder cancer (GBC) is a lethal cancer with a poor prognosis. The lack of specific and sensitive biomarkers results in delayed diagnosis with most patients presenting at late stages of the disease. Furthermore, there is little known about the molecular mechanisms associated with GBC, especially in patients of African ancestry. This study aimed to determine dysregulated proteins in South African GBC patients to identify potential mechanisms of the disease progression and plausible biomarkers. Methods: Tissues (27 GBC, 13 Gallstone disease, and 5 normal tissues) and blood plasma (54 GBC and 73 Benign biliary pathology) were obtained from consenting patients. Protein extraction was performed on all tissues and liquid chromatography-mass spectrometry was used for proteomic profiling. A project-specific spectral library was built using the Pulsar search algorithm. Principal component and Spearman's rank correlation analyses were performed using PAST (V4.07b). Pathway and Network analyses were conducted using REACTOME (v3.7) and stringAPP (v1.7.0), respectively. Results: In the tissue sample group, there were 62 and 194 dysregulated proteins in GBC compared to normal and gallstone groups, respectively. In the plasma group, there were 33 altered proteins in GBC compared to the benign biliary pathology group. We found 9 proteins (APOA1, APOA2, RET4, TTR, HEMO, HBB, HBA, PIGR, and APOE) to be commonly dysregulated in both tissue and plasma. Furthermore, a subset analysis demonstrated that 2 proteins, S100A8 and S100A9, were downregulated in GBC patients with GD history compared to those without. Pathway analysis showed that the dysregulated proteins in GBC patients were enriched in pathways involved in smooth muscle contraction, metabolism, ECM organization, and integrin cell surface interactions. Conclusion: The identified dysregulated proteins help in understanding GBC molecular mechanisms in our patient group. Furthermore, the alteration of specific proteins in both tissue and plasma samples suggests their potential utility as biomarkers of GBC in this sample cohort.
South Africa has experienced successive outbreaks of anti-immigrant violence in the last few decades, a phenomenon that seems to disproportionately impact informal migrant workers. Informal migrant workers are also perceived to be an economic threat to citizens. The existing research on pathogen stress would suggest that the shock of the current COVID-19 crisis could have led to a surge in xenophobia, exacerbating intergroup tension. Given the place of xenophobia in the current national discourse, there is increasing interest from academic researchers, development practitioners and international organisations in public attitudes towards migrants in South Africa. Using innovative public opinion data, this chapter explores mass views towards migrants living in South Africa, reflecting on how the pandemic changed the way ordinary people think about non-nationals. The chapter ends by offering an assessment of how mass views on immigration changed during the pandemic and puts forward recommendations on how to reduce xenophobia in the country.
The world has been facing a huge crisis of clean water for the past decade, and advanced applications of modern technologies in various industrial and commercial sectors are only adding to freshwater security problems. The ever-increasing use of synthetic and toxic chemicals in various industries plays the main role in water contamination. Moreover, the ultra-modern lifestyle is leading researchers to develop new and advanced products which are unfortunately not so environment friendly. Several harmful substances are now being recognized to be widely present in water resources which possess a potential risk to the environment and public health. Many researchers are labeling these as “emerging contaminants” or “emerging pollutants”, however, adequate data is not yet available to assess the complete risk. Such emerging pollutants may not necessarily be new chemicals, they may include substances that have been present in the environment for a long time but their extensive use and consequent detrimental effects on the environment are being discovered now. Hence, there is an urgent need to explore highly advanced methods and materials to remove such new contaminants. Membrane technology has come out as the choicest alternative to separate a range of new emerging pollutants from water bodies. This chapter focuses on the role of polymeric membranes in the advanced water treatment process. It also highlights the major trends in membrane technology with respect to novel materials, novel configuration, and major challenges such as membrane fouling, cleaning, and their potential application in reuse for potable water (PW).
Background: Couple-based interventions (CBIs), despite strong efficacy in improving numerous HIV risk behaviors, are not widely available and have not been tested to improve women's antiretroviral therapy (ART) adherence. We examined barriers and facilitators to participation in a CBI based on cognitive behavioral couple therapy for women's ART adherence in KwaZulu-Natal, South Africa. Methods: Semi-structured interviews were conducted with women with HIV (n = 15) and men of mixed HIV status (n = 15). Thematic analyses were guided by the Consolidated Framework for Implementation Research. Results: Facilitators mostly related to the couple's relationship, including having an existing healthy relationship, men's desire to support their partners, and a potential opportunity for men's HIV disclosure. Barriers included a lack of understanding of how a CBI approach would be useful for women's ART adherence, sole focus on women if male partners were also living with HIV, and men's lack of prior HIV status disclosure to female partners. Conclusion: Findings indicate that relationship context and the male partner's HIV status need to be addressed during recruitment, enrolment, and during the intervention to promote uptake.
Self-perceived health (SPH) is a widely used measure of health amongst individuals that indicates an individual’s overall subjective perception of their physical or mental health status. As rural to urban migration increases, the health of individuals within informal settlements becomes an increasing concern as these people are at high health and safety risk due to poor housing structures, overcrowding, poor sanitation and lack of services. This paper aimed to explore factors related to deteriorated SPH status among informal settlement dwellers in South Africa. This study used data from the first national representative Informal Settlements Survey in South Africa conducted by the Human Sciences Research Council (HSRC) in 2015. Stratified random sampling was applied to select informal settlements and households to participate in the study. Multivariate logistic regression and multinomial logistic regression analyses were performed to assess factors affecting deteriorated SPH among the informal settlement dwellers in South Africa. Informal settlement dwellers aged 30 to 39 years old (OR = 0.332 95%CI [0.131–0.840], p < 0.05), those with ZAR 5501 and more household income per month (OR = 0.365 95%CI [0.144–0.922], p < 0.05) and those who reported using drugs (OR = 0.069 95%CI [0.020–0.240], p < 0.001) were significantly less likely to believe that their SPH status had deteriorated compared to the year preceding the survey than their counterparts. Those who reported always running out of food (OR = 3.120 95%CI [1.258–7.737], p < 0.05) and those who reported having suffered from illness or injury in the past month preceding the survey (OR = 3.645 95%CI [2.147–6.186], p < 0.001) were significantly more likely to believe that their SPH status had deteriorated compared to the year preceding the survey than their counterparts. In addition, those who were employed were significantly (OR = 1.830 95%CI [1.001–3.347], p = 0.05) more likely to believe that their SPH status had deteriorated compared to the year preceding the survey than those who were unemployed with neutral SPH as a base category. Overall, the results from this study point to the importance of age, employment, income, lack of food, drug use and injury or illness as key determinants of SPH amongst informal settlement dwellers in South Africa. Given the rapid increasing number of informal settlements in the country, our findings do have implications for better understanding the drivers of deteriorating health in informal settlements. It is therefore recommended that these key factors be incorporated into future planning and policy development aimed at improving the standard of living and health of these vulnerable residents.
In response to the malaria parasite’s resistance towards quinoline-based antimalarial drugs, we have employed quinoline-containing compounds in combination with dihydropyrimidinone (DHPM) analogues as resistance reversal agents (RAs) and investigated their antimalarial activities based on DHPM’s resistance reversal abilities. The present study employed click chemistry to link DHPM and quinoline compounds which offered several synthetic advantages over the previously used amide coupling for the same hybrids. Among the synthesised compounds, 4 hybrids with the 7-chloroquinoline moiety showed antimalarial activity below 1 µM while compounds with the mefloquine moiety showed lower antimalarial activity than chloroquine (CQ) and the 7-chloroquinoline hybrids. Among the tested hybrids for the IC50 determination, four compounds displayed good antimalarial activity with increased sensitivity against the CQ-resistant K1 strain between 421 and 567 nM and showed higher activity between 138 and 245 nM against the NF54 CQ-sensitive strain, while three compounds have IC50 values greater than 5 µM. Additionally, in silico molecular docking and molecular dynamics studies were conducted to investigate the binding affinities of all the synthesised compounds as glutathione reductase protein competitive inhibitors. Further optimisation of the compound with the highest binding affinity generated 16 compounds with higher binding affinities than the flavine adenine dinucleotide (FAD) cofactor.
The control of the open loop unstable systems with nonlinear structure is challenging work. In this paper, for the first time, we present a sand cat swarm optimization (SCSO) algorithm-based state feedback controller design for open-loop unstable systems. The SCSO algorithm is a newly proposed metaheuristic algorithm with an easy-to-implement structure that can efficiently find the optimal solution for optimization problems. The proposed SCSO-based state feedback controller can successfully optimize the control parameters with efficient convergence curve speed. In order to show the performance of the proposed method, three different nonlinear control systems such as an Inverted pendulum, a Furuta pendulum, and an Acrobat robot arm are considered. The control and optimization performances of the proposed SCSO algorithm are compared with well-known metaheuristic algorithms. The simulation results show that the proposed control method can either outperform the compared metaheuristic-based algorithms or have competitive results.
Background In South Africa, similar to other populous countries, the taxi industry is an important form of transportation that contributes to the country's development. As a result, minibus taxi driving is an occupation characterized by strenuous activities such as long hours of driving, limited rest, and challenges related to securing passengers, among several others. Consequently, to combat stress, some commercial drivers resort to smoking, overeating unhealthy food sold at transportation interchange areas (i.e., taxi ranks), and participating in sedentary behaviors. Most of these activities are risk factors for metabolic syndrome (MetS). Aim Therefore, this study aimed to investigate the sociodemographic and lifestyle factors that predispose South African taxi drivers who work in the Cape Town Metropole area to the risk of developing MetS. Methods This cross-sectional study used a convenient sampling method that included 185 male minibus taxi drivers aged 20 years or above. The participants were interviewed using a validated questionnaire to gather information regarding their sociodemographic characteristics and lifestyle practices. They also underwent physical and metabolic assessments, and the International Diabetes Federation (IDF) criteria were used to diagnose people with MetS. Results Overall, the mean age and driving experience of the taxi drivers were 40.0 years (SD: 10.7) and 9.1 years (SD: 7.4), respectively, with those with MetS being significantly older and having more driving experience than those without. Older participants were 3 and 2.9 times more likely to be diagnosed with MetS than the younger participants. Most taxi drivers (70%) met the IDF diagnostic criteria for MetS. Smokers, those who spent more than 100 ZAR (USD 5.9) and those who spent less than 1.4 MET-minutes per week on physical activity were 1.96, 2.0, and 13.6 times more likely to suffer from MetS that those who were nonsmokers, those who spent less than 100 ZAR and those who spent <1.4 MET-minutes per week on physical activity. Consumption of alcohol and sugar-sweetened beverages (SSBs), as well as takeaway and fried foods, snacks, and sold by the SF vendors, increased the likelihood of developing MetS, abnormal HDL-C, TG, and hypertension, while avoiding takeaway and fried foods decreased this likelihood. Taxi drivers who also avoided consuming fresh fruits had abnormal HDL-C. Conclusion These findings have significant public health implications, highlighting the need for South African policymakers to adopt a system-level approach to promote lifestyle changes among taxi drivers within the taxi industry. This can help reduce the health risks faced by these drivers and improve their overall health profile.
Electromagnetic interference (EMI) shielding effectiveness (SE) systems have received immense attention from researchers owing to the rapid development in electronics and telecommunications, which is an alarming matter in our modern society. This radiation can damage the performance of EM devices and may harmfully affect animal/human health. The harmonious utilization of magnetic alloys and conducting but nonmagnetic materials (such as carbon/graphene) is a practical approach toward EMI SE. This review is not exhaustive, although it is comprehensive and aimed at all materials for EMI SE especially graphene-based polymeric composites. It encompasses multifunctional and functional structural EMI shields. These materials comprise polymers, carbons, ceramics, metals, cement composites/nanocomposites, and hybrids. The accessibility of abundant categories of carbon-based materials in their microscale, nanoscale, and quantum forms as EMI shields as polymer-carbon, cement-carbon, ceramic-carbon, metal-carbon, and their hybrids, makes them receive much attention, as a result of their unique amalgamation of electrical, magnetic, dielectric, thermal, and/or mechanical properties. Herewith, we have discussed the principles of EMI shields along with their design and state of the art basis and material architecture along with the drawbacks in research on EMI shields.
Nitrate-loaded Zn/Al, Mg/Al, and Mg-Zn/Al layered double hydroxides (LDHs) were synthesized using the coprecipitation method. The slow-release properties of LDHs were measured in powder form at various pH conditions. Sodium alginate was used to encapsulate Mg/Al LDH to produce composite beads (LB) to further slow down the release of nitrate ions. The prepared LDH samples and LB were characterized by X-ray diffraction, attenuated total reflectance Fourier transform infrared spectroscopy, thermogravimetric analysis, and inductively coupled plasma optical emission spectroscopy. The surface morphologies of LDHs and LB were obtained from scanning electron microscopy analysis. The slow-release properties of the materials were evaluated using a kinetic study of nitrate release in tap water, soil solution, as well as plant growth experiments using coriander (Coriandrum sativum). The nitrate release ability of LDHs and LB was compared with a soluble nitrate source. The plant growth experiments showed that all three LDHs were able to supply an adequate amount of nitrate to the plant similar to the soluble fertilizer while maintaining the availability of nitrate over extended periods. The ability of LDHs to increase soil pH was also demonstrated.
Industrialization and rapid urbanization in almost every country adversely affect many of our environmental values, such as our core ecosystem, regional climate differences and global diversity. The difficulties we encounter as a result of the rapid change we experience cause us to encounter many problems in our daily lives. The background of these problems is rapid digitalization and the lack of sufficient infrastructure to process and analyze very large volumes of data. Inaccurate, incomplete or irrelevant data produced in the IoT detection layer causes weather forecast reports to drift away from the concepts of accuracy and reliability, and as a result, activities based on weather forecasting are disrupted. A sophisticated and difficult talent, weather forecasting needs the observation and processing of enormous volumes of data. In addition, rapid urbanization, abrupt climate changes and mass digitization make it more difficult for the forecasts to be accurate and reliable. Increasing data density and rapid urbanization and digitalization make it difficult for the forecasts to be accurate and reliable. This situation prevents people from taking precautions against bad weather conditions in cities and rural areas and turns into a vital problem. In this study, an intelligent anomaly detection approach is presented to minimize the weather forecasting problems that arise as a result of rapid urbanization and mass digitalization. The proposed solutions cover data processing at the edge of the IoT and include filtering out the missing, unnecessary or anomaly data that prevent the predictions from being more accurate and reliable from the data obtained through the sensors. Anomaly detection metrics of five different machine learning (ML) algorithms, including support vector classifier (SVC), Adaboost, logistic regression (LR), naive Bayes (NB) and random forest (RF), were also compared in the study. These algorithms were used to create a data stream using the time, temperature, pressure, humidity and other sensor-generated information.
Access to healthcare services is largely determined by socioeconomic factors, with economically well-off individuals obtaining healthcare services more efficiently than those who are disadvantaged. This paper aims to assess the effects of socioeconomic and other related factors on access to healthcare facilities in the City of Tshwane, South Africa, during the COVID-19 pandemic. Data were sourced from the Gauteng City-Region Observatory (GCRO) quality of life survey (2020/2021). Multivariate logistic regression was applied. Results showed that 66.3% of the respondents reported that they had access to public healthcare facilities within their area. Furthermore, results showed that those who lived in informal houses were significantly (OR = 0.55, 95% CI [0.37–0.80], p < 0.01) less likely to report that they had access to public healthcare facilities in their area compared to those who lived in formal houses. More efforts need to be undertaken to ensure that all citizens have access to public healthcare facilities, especially among those who are disadvantaged, such as informal dwellers. In addition, future research should encompass locality in relation to the factors that affect access to public healthcare facilities, especially during pandemics such as the COVID-19 pandemic, in order to have geographically targeted interventions.
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1,055 members
Stoyan Stoychev
  • Biosciences Research Area
Hongze Luo
  • Materials Science and Manufacturing Research Area
Andrew Smith
  • NextGen Enterprises and Institutions
Kevin W Wellington
  • Biosciences Research Area
Sisa Pityana
  • National Laser Centre
Meiring Naude Street, Pretoria, South Africa
Head of institution
Dr Thulani Dlamini
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