“Bactricia nematodes Kby., 1894” (Phasmida, Diapheromeridae, Diapheromerinae) is a nomen nudum
- Authors: Villet, Martin H
- Date: 2024
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440615 , vital:73797 , https://doi.org/10.3897/ AfrInvertebr.65.115507
- Description: A review of published evidence indicates that Bactricia nematodes Kirby, 1894 is a nomen nudum because it is an unavailable name. The specimen collected during the Lund University Swedish South African Expedition and reported by this name is a male of Bactricia bituberculata (Schaum, 1857).
- Full Text:
- Date Issued: 2024
A Comparative Analysis of Speaker and Headphone-Based Immersive Audio in VR and Gaming Applications:
- Authors: Marais, Kyle , Foss, Richard
- Date: 2023
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/426705 , vital:72384 , https://ieeexplore.ieee.org/abstract/document/10289435
- Description: Precise and accurate audio spatialization is crucial for gaming and Virtual Reality (VR) applications, as it is an essential aspect of the immersion experienced by users. When the audio of a virtual environment is synchronized with its visual sources and localized accurately, users are more likely to feel deeply engaged and suspend their disbelief. Audio Middleware software is commonly used in cooperation with game engines to meet the audio requirements of virtual environments created by game developers. This research paper presents a comparative analysis of speaker-and headphone-based immersive audio systems within the context of VR. The research findings indicate that, despite the headphone-based system offering more accurate audio localization and a higher ‘perceived audio quality’, the speaker-based system resulted in a greater sense of ‘immersion.’.
- Full Text:
- Date Issued: 2023
Entomopathogenic fungi associated with cultivated honeybush, Cyclopia spp., in South Africa and their pathogenicity towards a leafhopper pest, Molopopterus sp.(Hemiptera: Cicadellidae)
- Authors: Mushore, Tapiwa G , Coombes, Candice A , Hill, Martin P
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/451382 , vital:75045 , http://dx.doi.org/10.17159/2254-8854/2023/a14183
- Description: The southern and eastern parts of the African Fynbos region favour the production of honeybush tea. Honeybush biomass and extracts are used to prepare a beverage both locally and internationally, mainly as herbal tea with health benefits. Honeybush tea is mostly grown organically requiring natural control measures for pests and diseases. The leafhopper, Molopopterus sp., is one of the most important pests of cultivated honeybush in South Africa, as its feeding compromises the quality and quantity of the yield through leaf discolouration and reduction of the photosynthetic area. Local entomopathogenic fungi (EPF) can provide a pool of potential biocontrol agents for this pest. Therefore, a total of 98 soil samples were collected from organically grown honeybush fields and vegetation surrounding the honeybush fields in the Western Cape province of South Africa. Entomopathogenic fungi were isolated using the insect bait method and were characterised using molecular techniques. Twenty fungal isolates of Metarhizium anisopliae and Fusarium oxysporum were recovered from soil samples, of which 70% were from honeybush fields and 30% were from surrounding vegetation.
- Full Text:
- Date Issued: 2023
Evaluating the establishment of a new water hyacinth biological control agent in South Africa
- Authors: Miller, Benjamin E , Coetzee, Julie A , Hill, Martin P
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/451399 , vital:75046 , http://dx.doi.org/10.17159/2254-8854/2023/a15613
- Description: Megamelus scutellaris Berg (Hemiptera: Delphacidae) is the most recent of nine biological control agents developed to manage invasive water hyacinth, Pontederia (= Eichhornia) crassipes Mart.(Pontederiaceae), in South Africa. More than a million M. scutellaris have been mass-reared and released since the first introduction of the agent into South Africa in 2013, successfully establishing overwintering populations at 32 sites in seven of the nine provinces. Establishment has also been recorded at seven of these sites through natural dispersal from sites where they had established. Inundative releases, where large numbers of M. scutellaris are released regularly, have resulted in excellent establishment, and caused a significant reduction in water hyacinth cover in areas where, historically, biological control seemed unlikely due to excessive eutrophication. Although M. scutellaris has established well throughout South Africa through classical biological control methods, this study also showed that inundative releases of biological control agents over multiple seasons results in the most effective control of the weed, especially at cool temperate and eutrophic sites.
- Full Text:
- Date Issued: 2023
Expansive Learning and Transformative Agency for Equity and Sustainability: Formative Interventions in Six Continents
- Authors: Engeström, Yrjö , Bal, Aydin , Sannino, Annalisa , Morgado, Luciana P , de Gouveia Vilela, R A , Querol, Marco P , Lotz-Sisitka, Heila , Wei, Ge , Chikunda, Charles , Hopwood, Nick , Virkkunen, Jaakko , Mukute, Mutizwa
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , symposium
- Identifier: http://hdl.handle.net/10962/436688 , vital:73293 , ISBN 978-3-030-99347-4 , https://repository.isls.org//handle/1/8974
- Description: This double symposium brings together activity-theoretical formative intervention research conducted in six continents. The aim is to illuminate and examine the common threads, important differences, and new challenges of formative inter-vention studies to address “wicked problems” in different cul-tural, political, and economic contexts. Formative interven-tions facilitate expansive learning and systemic transfor-mation led by local stakeholders in organizations and social movements. The formative intervention methodology is based on the principles of double stimulation and ascending from the abstract to the concrete. Its most well-known appli-cation is the Change Laboratory method. Formative interven-tions generate and support expansive learning and trans-formative agency. The current global crises of climate change, poverty and deepening inequalities are giving rise to what is called fourth generation activity theory for tackling fateful challenges by building heterogenous multiactivity coa-litions. The symposium will present the theoretical and peda-gogical challenges and possibilities in Change Laboratories and other formative interventions to develop just and sus-tainable solutions to global crises.
- Full Text:
- Date Issued: 2022
A leopard's favourite spots: habitat preference and population density of leopards in a semi-arid biodiversity hotspot
- Authors: Mann, Gareth K H , O'Riain, M Justin , Parker, Daniel M
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148584 , vital:38752 , https://doi.org/10.1016/j.jaridenv.2020.104218
- Description: Leopards (Panthera pardus) are the only free-ranging large predators to still occur naturally throughout much of Africa, but are vulnerable to habitat loss, ecosystem degradation and persecution. We used a systematic camera trap survey covering an area of ∼3100 km2 in the Little Karoo, a semi-arid biodiversity hotspot in South Africa, to assess the impacts of land use and habitat type on leopard density. Camera data were supplemented by opportunistic scat collection to produce a habitat suitability model. We used a habitat suitability model to inform spatially explicit capture-recapture models used to estimate population density. We recorded 152 independent photographs of 27 individually recognizable leopards at 54 camera stations and collected scats from a further 76 locations. Our habitat suitability model showed that primary productivity and vegetation type were the best predictors of leopard habitat suitability. Our best performing population density model allowed for detection and movement of individuals to vary according to sex, and estimated population density at 1.26 (SE ± 0.25) leopards/100 km2.
- Full Text:
- Date Issued: 2020
Acceptance of ambulatory blood pressure monitoring in a semi-rural population in South Africa:
- Authors: Chiwanza, Farisai , Irwin, Yoland , Dowse, Roslind
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/157072 , vital:40084 , DOI: https://doi.org/10.4102/hsag.v25i0.1336
- Description: Ambulatory blood pressure monitoring is a valuable tool that helps in providing an insight into the diagnosis and management of hypertension; however, no evidence exists of its acceptance in the diverse South African population. We assessed the acceptance of an ambulatory blood pressure monitor in patients attending public sector primary health care (PHC) clinics. Five PHC clinics in the Makana subdistrict in the Eastern Cape.
- Full Text:
- Date Issued: 2020
Bioelectrocatalysis and surface analysis of gold coated with nickel oxide/hydroxide and glucose oxidase towards detection of glucose:
- Authors: Njoko, Nqobile , Louzada, Marcel , Britton, Jonathan , Khene, Samson M , Nyokong, Tebello , Mashazi, Philani N
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150071 , vital:38937 , https://doi.org/10.1016/j.colsurfb.2020.110981
- Description: The fabricating of metal oxide thin films onto conducting surfaces continues to grow and their potential applications as surfaces for biosensor applications is of paramount importance. The correct orientation of glucose oxidase redox enzymes yields very important biointerfaces capable of selectively detecting D-glucose as a measure of blood sugar for healthy and diabetic sick patients. The electrodeposition of redox enzymes, such as glucose oxidase enzymes, onto gold electrode surfaces pre-modified with nickel oxide was investigated in this work.
- Full Text:
- Date Issued: 2020
Calling rhythm as a predictor of the outcome of vocal interactions: flight departure in pale-winged starling pairs
- Authors: Hausberger, Martine , Giacalone, Aline , Harmand, Mariane , Craig, Adrian J F K , Henry, Laurence
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/449283 , vital:74808 , https://doi.org/10.1007/s00114-019-1658-1
- Description: Vocal communication plays an important role in the regulation of social interactions and the coordination of activities in many animal species. Synchrony is an essential part of the establishment and maintenance of pair bonds, but few reports have investigated decision-making at the pair level. We investigated temporal characteristics of call exchanges in pale-winged starlings (Onychognathus nabouroup) that could predict whether one, two, or neither members of a pair would take off. Our analysis of these interactions revealed that the overall rhythm of a call exchange, as well as the acceleration towards the end of an interaction, were significantly associated with the type of behavioural outcome. Faster rhythms were associated with higher probabilities that both birds would fly away. Our results confirm the findings of previous studies showing that higher rates of alarm calls indicate imminent departure and highlight the relationship between temporal features of vocal interactions and their outcome.
- Full Text:
- Date Issued: 2020
Compounds isolation and biological activities of Piptadeniastrum africanum (hook. f.) Brennan (Fabaceae) roots:
- Authors: Teinkela, Jean E M , Noundou, Xavier S , Mimba, Jeanne E Z , Meyer, Franck , Tabouguia, Octavie M , Nguedia, Jules C A , Hoppe, Heinrich C , Krause, Rui W M , Wintjens, René , Azebaze, Anatole G B
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150084 , vital:38938 , https://doi.org/10.1016/j.jep.2020.112716
- Description: The dicotyledonous plant Piptadeniastrum africanum (hook.f.) Brennan (Fabaceae) is used in traditional medicine to treat various human complaints including bronchitis, coughing, urino-genital ailments, meningitis, abdominal pain, treatment of wounds, malaria and gastrointestinal ailments, and is used as a purgative and worm expeller. The present study describes the phytochemical investigation and the determination of the antimicrobial, antiplasmodial and antitrypanosomal activities of crude extract, fractions and compounds extracted from Piptadeniastrum africanum roots.
- Full Text:
- Date Issued: 2020
Congruence between fine-scale genetic breaks and dispersal potential in an estuarine seaweed across multiple transition zones:
- Authors: Nicastro, Katy R , Assis, Jorge , Serrão, Ester A , Pearson, Gareth A , Neiva, Joao , Valero, Myriam , Jacinto, Rita , Zardi, Gerardo I
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149873 , vital:38908 , https://0-doi.org.wam.seals.ac.za/10.1093/icesjms/fsz179
- Description: Genetic structure in biogeographical transition zones can be shaped by several factors including limited dispersal across barriers, admixture following secondary contact, differential selection, and mating incompatibility. A striking example is found in Northwest France and Northwest Spain, where the estuarine seaweed Fucus ceranoides L. exhibits sharp, regional genetic clustering. This pattern has been related to historical population fragmentation and divergence into distinct glacial refugia, followed by post-glacial expansion and secondary contact. The contemporary persistence of sharp ancient genetic breaks between nearby estuaries has been attributed to prior colonization effects (density barriers) but the effect of oceanographic barriers has not been tested. Here, through a combination of mesoscale sampling (15 consecutive populations) and population genetic data (mtIGS) in NW France, we define regional genetic disjunctions similar to those described in NW Iberia. Most importantly, using high resolution dispersal simulations for Brittany and Iberian populations, we provide evidence for a central role of contemporary hydrodynamics in maintaining genetic breaks across these two major biogeographic transition zones. Our findings further show the importance of a comprehensive understanding of oceanographic regimes in hydrodynamically complex coastal regions to explain the maintenance of sharp genetic breaks along continuously populated coastlines.
- Full Text:
- Date Issued: 2020
Cytotoxicity of triterpenoids from Clerodendrum glabrum against triple negative breast cancer cells in vitro:
- Authors: Teclegeorgish, Zecarias W , Mokgalaka, Ntebogeng S , Vukea, Nyeleti , de la Mare, Jo-Anne , Tembu, Vuyelwa J
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/161511 , vital:40634 , https://doi.org/10.1016/j.sajb.2020.07.009
- Description: Clerodendrum glabrum is an indigenous medicinal plant that is used to treat cough, cold, sore throat and chest complaints. The stem bark of Clerodendrum glabrum afforded four tritepenoids namely, 3β-olean-12-en-3-yl palmitate (β-amyrin palmitate), (1), 3β hydroxy 5-glutinene (glutinol), (2), 3β-lup-20(29)-en-3-palmitate (Lupeol-3-palmitate), (3), 3β-lup-20(29)-en-3-ol (lupeol) (4) and one common phytosterol (stigmasterol) (5). The structures were established on the basis of their spectroscopic analysis. The compounds were screened for cytotoxicity against the HCC70 triple negative breast cancer (TNBC), MCF-7 hormone receptor positive breast cancer and MCF-12A non-cancerous mammary epithelial cell lines.
- Full Text:
- Date Issued: 2020
Debunking the myth of lack of vocabulary for teaching content knowledge in primary schools: exploring terminology for science in Ekegusii of Kenya
- Authors: Mose, Peter
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150095 , vital:38939 , DOI: 10.1080/02572117.2020.1733827
- Description: The language-in-education policy to teach in mother tongues at lower primary level is not adhered to by classroom teachers in Kenya due to, among other reasons, lack of content terminology. The purpose of this study was to demonstrate that mother tongues can be used to teach science up to the end of grade three, considering the nature of topics for this level and other extra-classroom realities. Our research objectives were to examine the nature and content of science topics and sub-topics from grade one to grade three; examine conceptual and technical terms in grade one to grade three science textbooks; describe the Ekegusii equivalents of these terms; and explain the feasibility of teaching science in Ekegusii up to the end of grade three.
- Full Text:
- Date Issued: 2020
Events as catalyst to atact tourists to destinations: Spectator perceptions of the social impact of events in East London: A study of Spec-Savers Ironman South Africa 70.3 in Buffalo City
- Authors: Mxunyelwa, Siayabonga
- Date: 2020
- Language: English
- Type: Conference Proceeding
- Identifier: http://hdl.handle.net/11260/10868 , vital:75300
- Description: In recent years, globally events have shown rapid growth as types of attractions within destinations with such events creating a favourable image of a destination, expanding the traditional tourist season, spreading tourist demand evenly through an area and attracting foreign and domestic visitors. As far as South Africa is concerned attracting influx of tourists is the problem in the event sport tourism industry The objective of this study is to address this gap and to evaluate the social impact perceptions of event tourism spectators. The research design for the proposed study primarily involved exploratory and descriptive research. The target-sampling frame was the event tourism spectators at the Spec-Savers Ironman South Africa 70.3 Triathlon event held in East London. The findings suggest that the opportunity to meet new people, attend a major event and enhancing event tourism destination were deemed positive social impacts. Conversely, the study suggested that littering and social inequalities (exclusionary) are negative social impacts. The results in this study have produced a foundation that events management practitioners, event tourism planners, policy makers, decision makers, researchers and academics can utilise in planning for future events that are socially sustainable in a developing economy context such as South Africa.
- Full Text: false
- Date Issued: 2020
High genetic diversity and limited spatial structure in an endangered, endemic South African sparid, the red steenbras Petrus rupestris:
- Authors: Tang, Wei , Qiu, Yuanyuan , Li, Xiaonan , Soy, Rodah C , Mack, John , Nyokong, Tebello
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/160390 , vital:40441 , DOI: 10.6060/mhc200183l
- Description: Earth-abundant first row transition metal corrole complexes have played an important role in fundamental research due to their unique molecular structures and attractive properties. In comparison to porphyrins, corroles have three inner N-H protons and are ring-contracted with a smaller macrocyclic cavity. First row transition metal corroles have been widely used as effective electrochemical catalysts for small molecule activations, such as hydrogen evolution, oxygen reduction/evolution and CO2 reduction reactions (HERs, ORRs/OERs and CO2 RRs) through homogenous and/or heterogenous prodecures. Several strategies have been used to modulate the catalytic efficiency of synthetic metallocorroles.
- Full Text:
- Date Issued: 2020
Hop depletion reduces HSF1 levels and activity and coincides with reduced stress resilience:
- Authors: Chakraborty, Abantika , Edkins, Adrienne L
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/165440 , vital:41244 , https://doi.org/10.1016/j.bbrc.2020.04.072
- Description: Heat-shock factor 1 (HSF1) regulates the transcriptional response to stress and controls expression of molecular chaperones required for cell survival. Here we report that HSF1 is regulated by the abundance of the Hsp70-Hsp90 organizing protein (Hop/STIP1).
- Full Text:
- Date Issued: 2020
In Vitro Release Testing (IVRT) of Topical Hydrocortisone Acetate Creams: a novel approach using positive and negative controls
- Authors: Mudyahoto, Nyengeterai Amanda , Rath, Seeprarani , Ramanah, Ashmita , Kanfer, Isadore
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149849 , vital:38888 , dx.doi.org/10.14227/DT270120P6
- Description: The objective was to develop and validate an in vitro release testing (IVRT) method to assess the release of hydrocortisone acetate (HCA) from five topical formulations. A marketed generic cream containing 1% HCA was used as the reference product. Vertical diffusion cells (VDCs) were used to assess and compare the release rates of HCA from cream formulations containing 0.5%, 1%, and 1.5% HCA. The study describes a novel approach to test the discriminatory power by including both positive and negative controls to declare pharmaceutical equivalence or inequivalence. The validated method was found to be sensitive, linear, precise, reproducible, robust, and selective for the analysis of HCA from topical cream products. Equivalence or inequivalence was established based on SUPAC-SS acceptance criteria using a 90% CI with limits of 75–133.33%. The IVRT method was shown to have discriminatory ability to appropriately measure significant differences in drug release from various cream formulations. This approach also provides useful information for the future development of acceptable IVRT methods to assess topical dosage forms for local action containing different drugs.
- Full Text:
- Date Issued: 2020
Increasing temperatures increase the risk of reproductive failure in a near threatened alpine groundnesting bird, the Cape Rockjumper Chaetops frenatus:
- Authors: Oswald, Krista N , Diener, Elizabeth F , Diener, John P , Cunningham, Susan J , Smit, Ben , Lee, Alan T K
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149324 , vital:38825 , https://0-doi.org.wam.seals.ac.za/10.1111/ibi.12846
- Description: A major cause of reproductive failure in birds is nest predation. Predation risk depends on predator type, as predators vary in their ecology and sensory modalities (e.g. visual vs. olfactory). Snakes (generally olfactory predators) are a major nest predator for small birds, with predation strongly associated with higher temperatures. We investigated nest survival in a ground‐nesting alpine species, the Cape Rockjumper Chaetops frenatus , endemic to alpine fynbos in southwestern South Africa. We collected 3 years of nest data, testing whether nest survival was related to (1) habitat stage (early post‐fire vs. late post‐fire habitat, ≤ 3 and > 3 years since fire respectively), (2) nest concealment and (3) temperature. We found that nests had better survival at lower temperatures, with snake predation (our main source of predation) increasing in higher temperatures.
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- Date Issued: 2020
Non-aggregated lipophilic water-soluble tin porphyrins as photosensitizers for photodynamic therapy and photodynamic antimicrobial chemotherapy:
- Authors: Babu, Balaji , Soy, Rodah C , Mack, John , Nyokong, Tebello
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/158241 , vital:40165 , DOI: 10.1039/d0nj01564d
- Description: Two readily synthesized water-soluble Sn(IV) porphyrins have been prepared with quaternized pyridyl nitrogens and 2-naphthalato trans-axial ligands. Methyl and hexyl groups were attached to the quaternized nitrogens to form lipophilic dyes with high singlet oxygen quantum yields (ca. 0.90) and unusually long triplet state lifetimes. The dyes exhibit good photodynamic activity against MCF-7 cells with IC50 values of 14.3 and 8.5 μM, respectively. The hexyl quaternized dye exhibited a 9.69 log reduction value (0.5 μM) towards S. aureus under illumination for 90 min (250 mW cm−2). The results demonstrate that this set of structural modification strategies for photosensitizer dyes merits further in depth study.
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- Date Issued: 2020
Reconstructing the distribution of the non-native sea anemone, Diadumene lineata (Actiniaria), in the Canadian Maritimes: local extinction in New Brunswick and no regional range expansion in Nova Scotia since its initial detection
- Authors: Ma, Kevin C K , Glon, Heather E , Hawk, Heather L , Chapman, Cody N
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/179054 , vital:40095 , https://doi.org/10.1016/j.rsma.2020.101049
- Description: Since its first observations in New Brunswick (Sam Orr’s Pond) and Nova Scotia (Bedford Institute of Oceanography in Dartmouth) in 2009 and 2013, respectively, Diadumene lineata has been observed spreading to new locations in the Canadian Maritimes. In 2017 and 2018, regional surveys for non-native species did not detect D. lineata in New Brunswick, suggesting local extinction. Recent surveys also did not detect D. lineata in Prince Edward Island. However, between 2013 and 2018, D. lineata was detected in Nova Scotia (in chronological order) from Lunenburg Harbour (Lunenburg), Hermans Island (Lunenburg), Black Rock Beach (Halifax), Oak Island Marina (Chester), and Dartmouth Yacht Club (Dartmouth).
- Full Text:
- Date Issued: 2020