33074 research outputs found
Sort by
Culex quinquefasciatus mosquito avoids ovipositing in habitats with the annual fish (Nothobranchius neumanni) in Tanzania
Get PDFJournal Article, Faculty of Natural and Agricultural Sciences, Unit for Environmental Sciences and Management-- Potchefstroom CampusMosquitoes are known to choose oviposition habitats actively based on their suitability for survival of their offspring. They thus avoid laying eggs in dangerous habitats with aquatic predators through detection of their cues. Visual, tactile, and chemical cues emitted by certain predators have been shown to reduce oviposition in some mosquitoes, which in turn may affect their adult population sizes. However, those tests tend to be limited to species from temperate regions. Moreover, mosquito oviposition response to predator cues have been shown to be predator specific, but this has not been investigated for many potential predators worldwide. In the African subtropics, temporary ponds can be important mosquito breeding habitats and the same habitats are also used by a group of specialized killifish that can survive dry periods using drought resistant eggs. Although they are reported as mosquito predators, it is unknown whether mosquitoes actively avoid laying eggs in ponds with annual killifish. We investigated this using the mosquito Culex quinquefasciatus and the free and caged killifish Nothobranchius neumanni in the outdoor mesocosm experiments in Tanzania. We found that Cx. quinquefasciatus had 71% lower oviposition in mesocosms with free swimming killifish and 68% lower oviposition in mesocosms with caged killifish. We conclude that predator-released chemical cues alone are enough to explain the observed responses. If the cues can be isolated and chemically identified can be developed into a biological mosquito control strategy and used to safeguard public health in areas where mosquito borne diseases are endemic.Acknowledgements
-The authors thank the Tropical Pesticide Research Institute (TPRI) for granting a plot on which the experiment was conducted. The research was supported by funds (grant number TZ2019IUC029A101) from the VLIRUOS Interuniversity Cooperation (IUC) Programme at the Nelson Mandela African Institution of Science and Technology (NM-AIST)-Tanzania
Risk factors contributing to tick-acaricide control failure in communal areas of the Oliver Tambo district eastern cape province, South Africa
Get PDFArticle, Faculty of Natural and Agricultural Sciences (Unit for Environmental Sciences and Management)-- Northwest University, Potchefstroom CampusApplication of chemical acaricides in the control of ticks has led to the problem of tick- acaricide control failure. To obtain an understanding of the possible risk factors involved in this tick-acaricide control failure, this study investigated tick control practices on com-munal farms in the north-eastern part of the Eastern Cape Province (ECP) of South Af-rica. A semi-structured questionnaire designed to document specific farm attributes and acaricide usage practices was administered at 94 communal farms from the Oliver Tambo District municipality of the ECP. Data collected indicated that the main acaricide chemi-cals used at plunge dips of inland and coastal areas were synthetic pyrethroid formula-tions. Most (75%) farmers claimed not to have noticed a significant reduction in numbers of actively feeding and growing ticks on cattle after several acaricide treatments. Based on the farmers’ perceptions, leading factors that could have led to tick-acaricide control failure included: weak strength of the dip solution (76%); poor structural state of dip tanks (42%); and irregular tick control (21%). The rearing of crossbreeds of local and exotic cattle breeds, perceived weak strength of the dip solution and high frequency of acaricide treatment, were statistically associated with proportions of farms reporting tick-acaricidecontrol failure. Furthermore, approximately 50% of farms reported at least four tick con-trol malpractices, which could have resulted in the emergence and spread of tick-acaricide control failure. Other sub-optimal tick control practices encountered included incorrect acaricide rotation, and failure to treat all cattle in a herd. This data will inform and guide the development of management strategies for tick-acaricide control failure and resistance in communal farming areas
Developing a framework for SMME survival based on events during Covid-19 in the Western Cape, South Africa.
Get PDF, North-West University, Mahikeng CampusThis study aims to comprehend how certain SMMEs managed to survive, and some even thrived during the Covid pandemic in the Western Cape of South Africa. The impact of the pandemic and the various levels of lockdown in South Africa, as determined by the National Government, affected some SMMEs' operating capability more than others, as some had essential status and some did not. The surviving skills of these SMMEs have to be studied to ascertain how they survived. These survival skills and actions will assist the researcher in developing a framework for SMME survival in future difficult economic circumstances, such as a pandemic. The methodology approach to be followed in this study is by applying a qualitative research method, using semi-structured interviews to collect the data and then following a manual qualitative data analysis process. Research limitations of this study included the restrictions placed on the researcher via the POPI Act being applicable in South Africa. Hence, the successful SMMEs in the Western Cape could only be accessed via snowball sampling. The findings of this study will contribute to the literature about the challenges experienced by the SMMEs before and during the Covid period, the mentorship role and motivational factors that convinced them to start their SMMEs and how these aspects contributed to their SMME survival during a pandemic. Furthermore, this study will clarify what these SMMEs saw as necessary personal skills, attributes and characteristics an entrepreneur requires to survive a pandemic. The leadership styles of the SMME owner as applied have contributed to their survival, and this study will indicate in which way. Their view on success pre-Covid and post-Covid have been analysed to ascertain how the pandemic impacted their idea of what constitutes a successful SMME. The majority reported that their perceptions of success have changed since the pandemic. Whether the Western Cape Government's interventions created an entrepreneurial ecosystem was investigated, and whether these SMMEs received sufficient assistance to contribute to their survival, with the overall feeling that the government did not supply adequate support to SMMEs in the province. Finally, the factors they employed, their actions to survive or thrive, and their advice and recommendations have been recorded to answer this study's primary and secondary objectives to comprehend fully how SMMEs could survive the pandemic. Further study is recommended on how digitalisation and "going online" affected SMME survival and whether this can be grounds for creating a new entrepreneurial theory.Doctora
Perceived convenience as a driver of South African Generation Y consumers’ online repurchase intentions
Get PDFArticle, Faculty of Economic and Management Sciences (Workwell: Research Unit for Economic; Management Sciences)-- Northwest University, Potchefstroom CampusThe digital transformation and technological advancements resulting from the fourth industrial revolution (4IR), paired with other external factors including the ramifications of the COVID-19 pandemic, have led to the South African online retail market increasing by 66% in 2020 and surpassing a market value of R55 billion in 2022. While online shopping continues to increase steadily, reports of the factors impacting consumer repurchase intentions are vague in the literature, specifically from a consumer convenience perspective and in the South African context. As such, this study provides a departure point and employed the SERVCON (service convenience) model to investigate whether access, search, transaction, execution and post-service convenience had a statistically significant direct influence on South African Generation Y consumers’ online repurchase intentions. Following a descriptive research and cross sectional design, this study collected quantitative data from 400 Generation Y university students, using a self-administered questionnaire. While all five factors were significant, access convenience had a negative impact and execution convenience had no statistically significant influence on repurchase intentions. Nonetheless, the findings will guide academic and industry stakeholders in understanding consumers’ perceived convenience and how to optimise every aspect accordingly
Policy uncertainty, mergers, and acquisitions in the South African business environment
Get PDFJournal Article, Faculty of Economic and Management Sciences. School of Economic Sciences-- Potchefstroom CampusThis study examines policy uncertainty on mergers and acquisitions (M&A) in South Africa, emphasising the extensive regulatory review by the Competition Commission under the ‘public interest consideration’ criterion. It aims to identify the cost implications and uncertainties associated with M&A transactions to propose measures to reduce these uncertainties. Utilising qualitative methodologies, the study gathers empirical evidence through interviews with companies and competition lawyers involved in the M&A processes. The findings reveal significant concerns about economic uncertainty, merger control, and policy and regulation impacting investment decisions. Policy uncertainty, particularly in the context of merger regulation, imposes substantial cost implications and delays on M&A activities, negatively affecting investment, growth, and economic development. It emphasises the necessity for a regulatory framework that minimises disruptions and costs to business participants. The findings suggest that addressing policy uncertainty and streamlining regulatory processes are crucial steps towards enhancing South Africa's attractiveness as an investment destination and fostering economic growth and development
David versus Goliath? Indigenous people, carbon majors and climate litigation in South Africa
Get PDFJournal Article, Faculty of Law, Law; Justice and Sustainability-- Potchefstroom CampusIn two recent South African cases, Indigenous communities successfully challenged proposed fossil fuel exploration activities by the Shell petroleum company off South Africa's pristine West Coast. In contrast to earlier climate litigation cases in South Africa, the litigants relied specifically on their Indigenous rights and knowledge. In this case note, we highlight the ways in which the two courts engaged with the communities' cultural beliefs and practices as well as their knowledge related to sustainability and how this relates to protecting their livelihoods, cultural practices and identities that are threatened by the proposed activities. We highlight the important role played by Indigenous communities in the climate movement and argue that, in the future, Indigenous and related considerations could provide a strong basis for climate litigation in South Africa and potentially contribute to efforts to protect Indigenous communities against the activities of carbon majors.-Alexander von Humboldt Foundation;
-Research Institute for Sustainability Helmholtz
-Centre Potsdam, German
Characterization and diversity of potential mycotoxin producing endophytic fungi isolated from maize husk leaves
Get PDFJournal Article, Faculty of Natural and Agricultural Sciences, Microbiology-- Mahikeng CampusMaize (Zea mays L.) is an important staple food due to its good nutritional profile. Unfortunately, maize can be vulnerable to contamination by fungi, which are capable of producing mycotoxins that have an impact on human and animal health, crop productivity and lead to economic losses. In addition, the ubiquitous presence of mycotoxin-producing fungi in maize poses significant challenges to food safety and economic stability. Mycotoxins are toxic secondary metabolites produced by certain fungi, which, when ingested by humans or animals through contaminated maize products can lead to a variety of health issues. There is a shift of nonpathogenic microbes to pathogenic state due to unfavourable conditions arising. The aim of this study was to characterize and identify fungi that have the potential to produce mycotoxins isolated from maize husks. The study identified Fusaria sp., Aspergillus and Penicillium sp. as target species since they are often regarded as primary mycotoxin producing fungi, which often contaminates the maize plants. Ten (n=10) healthy (disease-free) and mature maize samples were obtained, and a total of 200 maize husk segments were utilized to isolate eighty-four (n=84) endophytic fungi. Preliminary identification was conducted using macroscopic and microscopic characteristics. Molecular processes using the Internal transcribed spacer region (ITS1 and ITS4) were used for PCR amplification as a confirmatory test. A total of 13 isolates were identified by macroscopic and microscopic characterization based on morphological features and their identification was confirmed using molecular techniques. Fusaria sp. were found to be predominant (46%), followed by Aspergillus sp. (39%) and Penicillium sp. (15%). The findings suggest a community of mycotoxin producing fungi inhibited within the maize husks. Under unfavourable conditions, these fungi might be the source of contamination and produce mycotoxins. In the face of changing environmental conditions and evolving fungal threats, our research serves as a valuable resource for understanding and addressing the challenges posed by mycotoxin contamination in maize. Effective strategies and interventions are essential to mitigate the impact of these fungi on food security, human health, and the global maize industry.Acknowledgements
We would like to thank the North-west University- Mafikeng Campus (Department of Microbiology
Developing an e-commerce risk management framework for online shopping in South Africa
Get PDFDoctor of Philosophy in Economic and Management Sciences with Business Administration, North-West University, Potchefstroom CampusIn a developing economy such as South Africa, e-commerce is experiencing rapid growth across different industries. This growth can be attributed to several factors, including the increasing penetration of mobile devices and the rise of mobile commerce. Another factor driving the growth of e-commerce in South Africa is the increasing popularity of social media platforms, such as Facebook and Instagram, as marketing and sales channels. This has made it easier for consumers to access online shopping platforms, leading to a growing demand for e-commerce services. The rapidly developing field of e-commerce has significantly changed the landscape of global trade, opening up previously unimaginable opportunities for businesses and consumers alike. The objective of this research was to develop an e-commerce risk management framework that is robust and adaptable for risk management and is particularly well-suited to the complexities of e-commerce environments. In this context, a mixed method research approach was utilised to analyse the perceived risks associated with online shopping to develop an e-commerce risk management framework for South African online shopping. A sequential exploratory research design was adopted for this study. The study employed an exploratory sequential design integrating quantitative and qualitative phases, utilizing random sampling for online shopping clients and convenience sampling for online shopping/e-commerce organizations, employing structured questionnaires for quantitative data collection and interviews stored through recorded transcripts for qualitative data, followed by meticulous data cleaning and coding for analysis through descriptive and inferential statistics for quantitative data and thematic analysis for qualitative data, resulting in a comprehensive understanding of online shopping adoption in South Africa. The proposed framework adopts a multidisciplinary approach to address the diverse difficulties associated with online transactions, drawing on insights from financial risk management, strategic management, and information security. The framework emphasizes the significance of adopting a proactive approach by offering a methodical and structured procedure for identifying, evaluating, and lowering risks across all stages of the e-commerce value chain. This research presents a major finding derived from significant research done to establish an e-commerce risk management strategy specifically tailored for the South African online shopping market. The aforementioned findings play a crucial role in comprehending the present condition of e-commerce risks in South Africa, as well as evaluating the effectiveness of the suggested framework in alleviating these risks. The study found multiple perceived hazards associated with e-commerce in South Africa. These risks encompassed financial, operational, cybersecurity, compliance, and reputational aspects. The frequency of fraudulent activities and payment scams highlighted the financial risks, whilst issues related to logistics, such as delivery inefficiencies, served as examples of operational risks. The escalating occurrences of data breaches and cyber-attacks have brought attention to the significance of cybersecurity risks. Additionally, the growing regulatory framework regulating e-commerce activities has given rise to compliance concerns. The success of e-commerce is closely linked to customer trust and happiness, as these factors are crucial in mitigating reputational concerns. The study advocates for ongoing research to continuously refine the risk management framework in line with emerging risks and technological advancements. It also encourages research into the long-term impacts of risk management strategies on consumer behavior and market expansion. In conclusion, the findings from this study provide a comprehensive understanding of the perceived risks associated with South African e-commerce and present a tailored framework for risk management. The recommendations put forth are designed to fortify the e-commerce sector against a myriad of risks, ensuring sustainable growth and bolstering consumer confidence. The study's outcomes are instrumental in charting a course for a resilient, secure, and thriving e-commerce industry in South Africa.-Wholesale and Retail Sector Education and Training Authority (W&RSETA
Dietary effects of Sclerocarya birrea caffra seed cake replacing soyabean meal on physiology, meat and bone quality of indigenous chickens
Get PDFArticle, Faculty of Natural & Agricultural Sciences (Food Security and Safety)--Northwest University, Mahikeng CampusThis study investigated marula seed cake (MSC) as alternative protein source (APS) replacing soyabean meal (SBM) in indigenous chicken diets. Four hundred, 3-week-old Boschveld chicks were randomly allocated to 5 iso-energetic nitrogenous maize and SBM-based grower diets with 0, 10, 15, 20, and 25 % MSC, each with 5 replicate pens of 16 birds, in a completely randomised design (CRD), for 9 weeks. Results showed that dietary MSC quadratically decreased bird overall feed intake (FI) (P 0.05) on overall feed conversion efficiency (FCE) and all other parameters. In conclusion, feeding of ≤ 15 % dietary MSC is nutritionally safe for indigenous chickens whilst detrimental on bird appetite, growth and meat yield, however without significantly affecting their physiology, at higher inclusion level
Experimental and numerical analysis of dilute gas-particle flow in a pipe section
Get PDFJournal Article, Faculty of Engineering, School of Mechanical Engineering-- Potchefstroom CampusCoal-fired power plants depend on the milling and conveying of Pulverised Coal (PC), where the coal is milled down and then distributed through a network of pipes, using pneumatic transport, to individual burners that feed the boilers. These systems can be plagued by various operational problems due to varying flow conditions, which can even lead to unplanned plant breakdowns and illegal emission of pollutants. The quality of PC gas-particle mixtures and flow stability can be improved by online measurement of particle mass flow and size distributions. A Particle Flow Test Loop (PFTL) was available that includes a blower fan providing gas flow for the system, a solid particle feeder to mix particles with the gas, a number of long pipe sections, and finally, a cyclone separator and gas cleaning system. To enable particle flow measurements, a new pipe test section for the PFTL was designed and analysed using computational fluid dynamics (CFD) simulations. The multiphase software code Neptune CFD by EDF was used in conjunction with Ansys Fluent and Siemens Star-CCM+. The final design was manufactured and fitted to the PFTL and can accommodate measurement devices such as an offline isokinetic sampler as well as online laser-based devices. Two-phase CFD modelling was used to predict cross-sectional solid concentrations for comparison with experimental measurements of particle velocity and particle size distribution. In this paper, selected results from the gas-particle flow simulations are presented, together with comparisons to experimental measurements taken inside the PFTL test section