
Cape Peninsula University of Technology
UniversityCape Town, South Africa
Research output, citation impact, and the most-cited recent papers from Cape Peninsula University of Technology (South Africa). Aggregated across the NobleBlocks index of 300M+ scholarly works.
Top-cited papers from Cape Peninsula University of Technology
Diabetes mellitus has been recognised as one of the four major non-communicable diseases that demands urgent attention from all key shareholders globally in an effort to address its prevalence and associated complications. It is considered as a top 10 cause of death globally, killing about 1.6 million people worldwide and is seen as the third highest risk factor for worldwide premature mortality due to hyperglycaemia and hyperglycaemic-induced oxidative stress and inflammation. There is a strong link between hyperglycaemia, hyperglycaemic-induced oxidative stress, inflammation and the development and progression of type 2 diabetes mellitus. Various reports have shown that chronic low-grade inflammation is associated with the risk of developing type 2 diabetes and that sub-clinical inflammation contributes to insulin resistance and is linked to the characteristics of metabolic syndrome which include hyperglycaemia. Oxidative stress stimulates the generation of inflammatory mediators and inflammation in turn enhances the production of reactive oxygen species. This interaction between diabetes, oxidative stress and inflammation is the primary motivation for the compilation of this review. Based on previous studies, the review examines the interaction between diabetes, oxidative stress and inflammation, factors promoting prevalence of diabetes mellitus, mechanisms involved in hyperglycaemia-induced oxidative stress with particular focus on type 2 diabetes and selected diabetic complications.
Abstract Body-mass index (BMI) has increased steadily in most countries in parallel with a rise in the proportion of the population who live in cities 1,2 . This has led to a widely reported view that urbanization is one of the most important drivers of the global rise in obesity 3–6 . Here we use 2,009 population-based studies, with measurements of height and weight in more than 112 million adults, to report national, regional and global trends in mean BMI segregated by place of residence (a rural or urban area) from 1985 to 2017. We show that, contrary to the dominant paradigm, more than 55% of the global rise in mean BMI from 1985 to 2017—and more than 80% in some low- and middle-income regions—was due to increases in BMI in rural areas. This large contribution stems from the fact that, with the exception of women in sub-Saharan Africa, BMI is increasing at the same rate or faster in rural areas than in cities in low- and middle-income regions. These trends have in turn resulted in a closing—and in some countries reversal—of the gap in BMI between urban and rural areas in low- and middle-income countries, especially for women. In high-income and industrialized countries, we noted a persistently higher rural BMI, especially for women. There is an urgent need for an integrated approach to rural nutrition that enhances financial and physical access to healthy foods, to avoid replacing the rural undernutrition disadvantage in poor countries with a more general malnutrition disadvantage that entails excessive consumption of low-quality calories.
Soil is a fundamental resource and it is crucial to manage its quality in order to enhance agricultural productivity and environmental quality. Soil enzymes catalyze several biochemical reactions which result in the transformation of organic matter, and the release of inorganic nutrients for plant growth and nutrient cycling. Soil enzyme activities are useful biological soil quality indicators since they are operationally practical, very sensitive, integrative, easy to measure and more responsive to soil tillage and structure than other soil variables. There are several enzymes in soil, but those involved in hydrolases and the degradation of main litter components are used most often for evaluating soil quality. This paper reviews the roles of soil enzymes such as -glucosidase, phosphatase and urease, as well as the implications of their activities for soil quality.
Acinetobacter are a major concern because of their rapid development of resistance to a wide range of antimicrobials, and rapid profundity in transformation, surviving desiccation and persisting in the environment for a very long time. The organisms are associated with bacteraemia, pulmonary infections, meningitis, diarrhea and notorious nosocomial infections with mortality rates of 20 to 60%. Transmission is via person-to-person contact, water and food contamination, and contaminated hospital equipment. The increasing virulence and rapid development of multidrug resistance by these organisms highlights the need to search for alternatives for chemotherapy. A poor understanding of the organisms and dearth of information about their occurrence especially in developing countries informed the need for this review paper.
Purpose This paper aims to examine the influence of interactive social media marketing communications on teenagers’ cognitive, affective and behavioral attitude components in South Africa. The study also considers the impact of a number of additional factors such as usage (access, length of usage, log-on frequency, log-on duration and profile update incidence) and demographic (gender, age and population group) variables on young consumers’ attitudes toward social media marketing communications. Design/methodology/approach A survey was used via three self-administered questionnaires, which were distributed to over 13,000 learners in the age range of 13-18 years (Generation Z cohort) at colleges and high schools in South Africa. A generalized linear model was used for statistical data analysis. Findings The study ascertained that social media marketing communications had a positive on each attitude component among adolescents, but on a declining scale, which correlates to the purchase funnel. The results also revealed that teenagers who used social media for long time periods; updated their profiles frequently and were from the Colored and Black population groups, displayed the most favorable attitudinal responses to social media marketing communications. Research limitations/implications Social media was collectively analyzed and did not consider the number of different social media types, which could be examined individually. This investigation only considered the Generation Z cohort, but other cohorts to attitudes toward social media marketing communications could also be assessed. Practical implications Companies and their brands should consider using and/or adapting their strategies based on the declining impact of social media marketing communications on the hierarchical attitude stages among young consumers and the divergent influence on usage and demographic variables when targeting the lucrative and technologically advanced, but capricious, Generation Z consumers. Originality/value This research established that social media marketing communications had a favorable influence on cognitive, affective and behavioral attitude components among young consumers, but on a declining scale, which is in congruence with the purchase funnel model. This investigation also makes an important contribution to attitudinal research in developing countries, where there is a lack of research in social media marketing communications.
Purpose – The purpose of this paper is to investigate the influence of behavioural attitudes towards the most popular social medium in the world, Facebook, amongst Millennials in South Africa (SA), and to determine whether various usage and demographic variables have an impact on intention-to-purchase and purchase perceptions. Design/methodology/approach – Quantitative research was conducted by means of a survey among a sample of over 3,500 respondents via self-administered structured questionnaires in SA. A generalised linear model was used to analyse the data. Findings – The results confirm that advertising on Facebook has a positive influence on the behavioural attitudes (intention-to-purchase and purchase) of Millennials who reside in SA. The usage characteristics, log on duration and profile update incidence, as well as the demographic influence of ethnic orientation also resulted in more favourable perceptions of Facebook advertising. Research limitations/implications – Research on Facebook advertising was only conducted in SA, whereas other emerging countries warrant further investigation to establish if they share the slight positive sentiment towards intention-to-purchase and purchase. This inquiry only provides a “snap shot” of behavioural attitudes, usage and demographic factors towards social media advertising, whereas future research could consider the development of cognitive, affective and behavioural attitudes towards Facebook advertising by employing longitudinal and qualitative research designs. Practical implications – Organisations and managers should consider that their existing Facebook advertising strategies may only have a limited effect on intention-to-purchase and purchase in SA. However, certain usage characteristics, namely the more time spent logged on to Facebook and the greater frequency of profile update incidence, as well as the demographic variable, namely black and coloured Millennials, resulted in more favourable behavioural attitudes towards Facebook advertising. Hence, organisations and managers should be prepared to alter or adapt their Facebook advertising tactics accordingly when targeting the notoriously fickle Millennials. Originality/value – This investigation found that Facebook advertising has a nominal positive influence on behavioural attitudes among Millennials, which is in congruence with the communications of the effect pyramid model that was established through traditional advertising research. This paper also makes a noteworthy contribution to attitudinal research in emerging countries where there is a dearth of research in social media advertising.
and allied fusarioid genera (www.fusarium.org).
Produced from experiences at the outset of the intense times when Covid-19 lockdown restrictions began in March 2020, this collaborative paper offers the collective reflections and analysis of a group of teaching and learning and Higher Education (HE) scholars from a diverse 15 of the 26 South African public universities. In the form of a theorised narrative insistent on foregrounding personal voices, it presents a snapshot of the pandemic addressing the following question: what does the 'pivot online' to Emergency Remote Teaching and Learning (ERTL), forced into urgent existence by the Covid-19 pandemic, mean for equity considerations in teaching and learning in HE? Drawing on the work of Therborn (2009: 20-32; 2012: 579-589; 2013; 2020) the reflections consider the forms of inequality - vital, resource and existential - exposed in higher education. Drawing on the work of Tronto (1993; 2015; White and Tronto 2004) the paper shows the networks of care which were formed as a counter to the systemic failures of the sector at the onset of the pandemic.
Antioxidants are compounds that inhibit the oxidation of other molecules and protect the body from the effects of free radicals, produced either by normal cell metabolism or as an effect of pollution and exposure to other external factors and are responsible for premature aging and play a role in cardiovascular disease. degenerative diseases such as cataracts, Alzheimer's disease, and cancer. While many antioxidants are found in nature, others are obtained in synthetic form and reduce oxidative stress in organisms. This review highlights the pharmacological relevance of antioxidants in fruits, plants, and other natural sources and their beneficial effect on human health through the analysis and in-depth discussion of studies that included phytochemistry and their pharmacological effects. The information obtained for this review was collected from several scientific databases (ScienceDirect, TRIP database, PubMed/Medline, Scopus, Web of Science), professional websites, and traditional medicine books. Current pharmacological studies and evidence have shown that the various natural antioxidants present in some fruits, seeds, foods, and natural products have different health-promoting effects. Adopting functional foods with high antioxidant potential will improve the effective and affordable management of free radical diseases while avoiding the toxicities and unwanted side effects caused by conventional medication.
Soil enzymes regulate ecosystem functioning and in particular play a key role in nutrient cycling. In this review we briefly summarise potential roles of selected enzymes such as amylase, arylsulphatases, -glucosidase, cellulose, chitinase, dehydrogenase, phosphatase, protease and urease in the ecosystem. We also highlight areas where further research is needed to increase our understanding of other possible role(s) of enzymes and factors that may affect their activities in the ecosystem.
The multicell converter topology is said to possess a natural voltage balancing property. This paper is the first of a two-part series in which multicell converters are modelled for the general case of p-cells. This paper focuses on the development of the natural balancing theory for the two-cell case. An understanding of the two-cell case is fundamental to understanding the general balancing theory. The switching functions used in switching these converters are mathematically analyzed. Equivalent circuits are derived and presented. The switching and balancing properties of these converters are mathematically analyzed. The main conclusion of the analysis is that the natural balancing of these converters are influenced by three factors namely, the harmonic content of the reference waveform, the switching frequency and the load impedance. Mathematical tools are presented that can help designers to predict if balancing problems would occur for a particular set of operating conditions. As a result of the detailed understanding of the balancing mechanism that is gained through this theory it is shown that by adding a balance booster, the load impedance can be manipulated to improve the natural balancing of the converter. Simulation results are included to verify the presented balance theory and properties
Abstract High blood cholesterol is typically considered a feature of wealthy western countries 1,2 . However, dietary and behavioural determinants of blood cholesterol are changing rapidly throughout the world 3 and countries are using lipid-lowering medications at varying rates. These changes can have distinct effects on the levels of high-density lipoprotein (HDL) cholesterol and non-HDL cholesterol, which have different effects on human health 4,5 . However, the trends of HDL and non-HDL cholesterol levels over time have not been previously reported in a global analysis. Here we pooled 1,127 population-based studies that measured blood lipids in 102.6 million individuals aged 18 years and older to estimate trends from 1980 to 2018 in mean total, non-HDL and HDL cholesterol levels for 200 countries. Globally, there was little change in total or non-HDL cholesterol from 1980 to 2018. This was a net effect of increases in low- and middle-income countries, especially in east and southeast Asia, and decreases in high-income western countries, especially those in northwestern Europe, and in central and eastern Europe. As a result, countries with the highest level of non-HDL cholesterol—which is a marker of cardiovascular risk—changed from those in western Europe such as Belgium, Finland, Greenland, Iceland, Norway, Sweden, Switzerland and Malta in 1980 to those in Asia and the Pacific, such as Tokelau, Malaysia, The Philippines and Thailand. In 2017, high non-HDL cholesterol was responsible for an estimated 3.9 million (95% credible interval 3.7 million–4.2 million) worldwide deaths, half of which occurred in east, southeast and south Asia. The global repositioning of lipid-related risk, with non-optimal cholesterol shifting from a distinct feature of high-income countries in northwestern Europe, north America and Australasia to one that affects countries in east and southeast Asia and Oceania should motivate the use of population-based policies and personal interventions to improve nutrition and enhance access to treatment throughout the world.
Antioxidants are important ingredients that are present in fruits and vegetables (FAV). With increased consumption of FAV in its raw and processed form, a predominantly plant-based diet rich in FAV could reduce the risk of the development of chronic human diseases. This review highlights the potentials of the various types of antioxidants containing FAV; their impact on human health as nutraceuticals, pharmaceuticals, and phytoceuticals; as well as prospects in tackling some chronic human diseases. The structures and activity relationship of the antioxidant compounds, as well as their mechanism of action, are examined from current scientific investigations. Information provided herein will give more insight into the roles of antioxidant ingredients present in FAV.
Pollinating species are in decline globally, with land use an important driver. However, most of the evidence on which these claims are made is patchy, based on studies with low taxonomic and geographic representativeness. Here, we model the effect of land-use type and intensity on global pollinator biodiversity, using a local-scale database covering 303 studies, 12,170 sites, and 4502 pollinating species. Relative to a primary vegetation baseline, we show that low levels of intensity can have beneficial effects on pollinator biodiversity. Within most anthropogenic land-use types however, increasing intensity is associated with significant reductions, particularly in urban (43% richness and 62% abundance reduction compared to the least intensive urban sites), and pasture (75% abundance reduction) areas. We further show that on cropland, the strongly negative response to intensity is restricted to tropical areas, and that the direction and magnitude of response differs among taxonomic groups. Our findings confirm widespread effects of land-use intensity on pollinators, most significantly in the tropics, where land use is predicted to change rapidly.
Recently, big data streams have become ubiquitous due to the fact that a number of applications generate a huge amount of data at a great velocity. This made it difficult for existing data mining tools, technologies, methods, and techniques to be applied directly on big data streams due to the inherent dynamic characteristics of big data. In this paper, a systematic review of big data streams analysis which employed a rigorous and methodical approach to look at the trends of big data stream tools and technologies as well as methods and techniques employed in analysing big data streams. It provides a global view of big data stream tools and technologies and its comparisons. Three major databases, Scopus, ScienceDirect and EBSCO, which indexes journals and conferences that are promoted by entities such as IEEE, ACM, SpringerLink, and Elsevier were explored as data sources. Out of the initial 2295 papers that resulted from the first search string, 47 papers were found to be relevant to our research questions after implementing the inclusion and exclusion criteria. The study found that scalability, privacy and load balancing issues as well as empirical analysis of big data streams and technologies are still open for further research efforts. We also found that although, significant research efforts have been directed to real-time analysis of big data stream not much attention has been given to the preprocessing stage of big data streams. Only a few big data streaming tools and technologies can do all of the batch, streaming, and iterative jobs; there seems to be no big data tool and technology that offers all the key features required for now and standard benchmark dataset for big data streaming analytics has not been widely adopted. In conclusion, it was recommended that research efforts should be geared towards developing scalable frameworks and algorithms that will accommodate data stream computing mode, effective resource allocation strategy and parallelization issues to cope with the ever-growing size and complexity of data.
A critical global issue in the 21st century is water shortage, as well as its pollution with noxious metal ions and organic dyes. To extract these pollutants from wastewater, a variety of traditional methods have been employed but they lack reusability/recyclability, are expensive, environmentally unfriendly, unsafe and the remediation process takes a long time. Therefore, to treat these contaminants, nanotechnology (NT) has recently been granted several leeways in terms of making the desirable nanomaterials (NMs) with high surface-to-volume ratios and special surface functionalities. In particular, fly ash (FA) has stood out as one of the greatest exciting new-found affordable and high efficient materials for water decontamination owing to its high porosity, huge surface area, and exceptional features. Hence, this present review study will attempt to compile data from existing literature on the utilization of FA-based adsorbent for the removal of heavy metals (HMs) and dyes from wastewater. Based on the reviewed publications, Langmuir's isotherm models (LIMs) and Freundlich's isotherm models (FIMs) best described the sorption process thus signalling monolayer and multi-layer sorptions. Pseudo-second-order (PSO) model provided the best appropriate means in elucidating the kinetic process and both exothermic and endothermic processes revealed the nature of the thermodynamic process during sorption. Some recommendations in the form of future prospects on how to advance the capacity of the adsorption and effectiveness of FA on the removal of HMs, dyes and other environmental contaminants using innovative technologies such as the nanofiber technology is also been proposed.
UNLABELLED: Terbium offers 4 clinically interesting radioisotopes with complementary physical decay characteristics: (149)Tb, (152)Tb, (155)Tb, and (161)Tb. The identical chemical characteristics of these radioisotopes allow the preparation of radiopharmaceuticals with identical pharmacokinetics useful for PET ((152)Tb) and SPECT diagnosis ((155)Tb) and for α- ((149)Tb) and β(-)-particle ((161)Tb) therapy. The goal of this proof-of-concept study was to produce all 4 terbium radioisotopes and assess their diagnostic and therapeutic features in vivo when labeled with a folate-based targeting agent. METHODS: (161)Tb was produced by irradiation of (160)Gd targets with neutrons at Paul Scherrer Institute or Institut Laue-Langevin. After neutron capture, the short-lived (161)Gd decays to (161)Tb. (149)Tb, (152)Tb, and (155)Tb were produced by proton-induced spallation of tantalum targets, followed by an online isotope separation process at ISOLDE/CERN. The isotopes were purified by means of cation exchange chromatography. For the in vivo studies, we used the DOTA-folate conjugate cm09, which binds to folate receptor (FR)-positive KB tumor cells. Therapy experiments with (149)Tb-cm09 and (161)Tb-cm09 were performed in KB tumor-bearing nude mice. Diagnostic PET/CT ((152)Tb-cm09) and SPECT/CT ((155)Tb-cm09 and (161)Tb-cm09) studies were performed in the same tumor mouse model. RESULTS: Carrier-free terbium radioisotopes were obtained after purification, with activities ranging from approximately 6 MBq (for (149)Tb) to approximately 15 MBq (for (161)Tb). The radiolabeling of cm09 was achieved in a greater than 96% radiochemical yield for all terbium radioisotopes. Biodistribution studies showed high and specific uptake in FR-positive tumor xenografts (23.8% ± 2.5% at 4 h after injection, 22.0% ± 4.4% at 24 h after injection, and 18.4% ± 1.8% at 48 h after injection). Excellent tumor-to-background ratios at 24 h after injection (tumor to blood, ≈ 15; tumor to liver, ≈ 5.9; and tumor to kidney, ≈ 0.8) allowed the visualization of tumors in mice using PET ((152)Tb-cm09) and SPECT ((155)Tb-cm09 and (161)Tb-cm09). Compared with no therapy, α- ((149)Tb-cm09) and β(-)-particle therapy ((161)Tb-cm09) resulted in a marked delay in tumor growth or even complete remission (33% for (149)Tb-cm09 and 80% for (161)Tb-cm09) and a significantly increased survival. CONCLUSION: For the first time, to our knowledge, 4 terbium radionuclides have been tested in parallel with tumor-bearing mice using an FR targeting agent. Along with excellent tumor visualization enabled by (152)Tb PET and (155)Tb SPECT, we demonstrated the therapeutic efficacy of the α-emitter (149)Tb and β(-)-emitter (161)Tb.
This paper focuses on the development of the natural balancing theory for the p-cell case. It describes the relationship between the models for different numbers of cells in a generic model for a p-cell multicell converter. The model discussed is based on the same principles that were used to develop the two-cell model in , except that the mathematics is much more involved. The same conclusions that were found to be true for the two-cell case was also found to be true for the general case of p cells. These conclusions include that the natural balancing mechanism of multicell converters depends on the overlap of the groups of harmonics of the switching function as well as on the load impedance. It will also be shown that the self-balancing mechanism ensures safe operation under most operating conditions where a high enough switching frequency is chosen and the load is not purely reactive. Two new aspects of the balancing theory were identified in the p-cell case: 1) for fixed duty-cycle modulation there exists certain values of the duty-cycle that causes the natural balancing mechanism to fail and 2) for p-cell converters the balance booster concept can be extended to a number of balance boosters tuned to multiples of the switching frequency. A "DesignTool" based on the balancing theory was developed to aid practicing engineers in designing multicell converters
The development of antiretroviral drugs has significantly changed the perception of HIV/AIDS from a very fatal to a chronic and potentially manageable disease, and the availability and administration of antiretroviral therapy (ART) has significantly reduced mortality and morbidity associated with HIV and AIDS. There is a relationship between ART and quality of life of people living with HIV and AIDS, and several studies have reported a strong positive association between ART and improved quality of life in different domains among people living with HIV and AIDS in both developed and developing countries. However, a few studies have reported on the negative effects of ART, which directly or indirectly relate to the quality of life and longevity of HIV-infected persons. In this review, the effects and benefits of ART on people living with HIV and AIDS based on studies done in developed and developing countries is examined.
Pollutants in water or wastewater raise grave public health problems. This review provides a concise summary of the potential applications of activated carbon derived from various sources. Here is an overview of the activated carbon properties and materials used to produce activated carbon. It also explores different techniques for creating active carbon for improved performance in specific applications, particularly low-cost adsorbents for heavy metal and synthetic dye removal.