Biological control of South African plants that are invasive elsewhere in the world: A review of earlier and current programmes
- Authors: Olckers, Terence , Coetzee, Julie A , Egli, Daniella , Martin, Grant D , Paterson, Iain D , Sutton, Guy F , Wood, Alan R
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/414336 , vital:71137 , xlink:href="https://hdl.handle.net/10520/ejc-ento_v29_n3_a21"
- Description: South Africa supports a rich floral diversity, with 21 643 native plant taxa that include a high proportion (76.3%) of endemic species, and many of these favoured as ornamentals, both locally and globally. Consequently, South Africa has contributed substantially to global plant invasions, with 1093 native taxa (5% of all species) naturalized in other countries. At least 80 taxa are invasive in natural or semi-natural ecosystems elsewhere, while an additional 132 taxa are potentially invasive. Of the global naturalized flora, 8.2% originate from South Africa and largely comprise species of Poaceae, Asteraceae, Iridaceae and Fabaceae. Australia, in particular, but also Europe and North America are major recipients of South African weeds. However, few countries have targeted South African plants for biological control (biocontrol), with most efforts undertaken by Australia. Previous and current targets have involved only 26 species with 17 agents (15 insects, one mite and one rust fungus) of South African origin released on five target species in Australia and the United States of America. South Africa’s history of weed biocontrol, together with a large cohort of active scientists, is currently facilitating several internationally funded programmes targeting invasive plants of South African origin. In particular, the recently inaugurated Centre for Biological Control at Rhodes University and the University of KwaZulu-Natal have provided the impetus for novel efforts on five new target species and renewed efforts on four previously targeted species. In this contribution, we review the history of earlier biocontrol programmes against weeds of South African origin and the status of projects currently in progress in South Africa.
- Full Text:
- Date Issued: 2021
Book Review Quinn, L.(ed.) 2019. Re-imagining Curriculum: Spaces for Disruption
- Authors: McKenna, Sioux
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/185865 , vital:44441 , xlink:href="https://journals.co.za/doi/abs/10.14426/cristal.v9i1.434"
- Description: This book is in some ways a continuation of the conversation begun with Reimaging Academic Staff Development: Spaces for Disruption (2012), also edited by Lynn Quinn. But the 2019 volume takes a much wider viewpoint including, as it does, twenty chapters by forty-two authors who are academics and academic developers across institutional types from Australia, Canada, South Africa, the United States of America, the United Kingdom, and the West Indies. Quinn and Vorster (2019: 2) state in Chapter One that the purpose of the book is 'to share theoretical perspectives and practical ideas for ways in which academic developers (and academic leaders) can work in partnership with lecturers and students to respond to the urgent calls for curriculum transformation and decolonisation'. This captures the four threads that run throughout the collection.
- Full Text:
- Date Issued: 2021
Borneol-triarylcorrole hybrids with chiral-optical response and anticancer behaviours
- Authors: Fu, Bo , Wang, Lin , Yu, Xiaoxiao , Fang, Xianying , Mack, John , Dingiswayo, Somila , Nyokong, Tebello , Liang, Xu , Xu, Haijun
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/185294 , vital:44362 , xlink:href="https://doi.org/10.1016/j.dyepig.2021.109699"
- Description: A series of four multifunctional A2B type H3corroles with meso-borneol substituents at the B position have been synthesized and characterized. A detailed analysis of the optical properties was carried out, and a comparison was made with theoretical calculations to identify the key trends in the structure-property relationships. The meso-borneol substituent couples with the corrole core leading to clear CD signals in the B band region. Enhanced anti-cancer properties are observed in vitro relative to (−)-borneol with cell inhibition rates of up to 94%.
- Full Text:
- Date Issued: 2021
Breaking the Rules: Zodwa Wabantu and postfeminism in South Africa
- Authors: Boshoff, Priscilla A
- Date: 2021
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/177408 , vital:42819 , http://dx.doi.org/10.17645/mac.v9i2.3830
- Description: Zodwa Wabantu, a South African celebrity recently made popular by the Daily Sun, a local tabloid newspaper, is notorious as an older working-class woman who fearlessly challenges social norms of feminine respectability and beauty. Her assertion of sexual autonomy and her forays into self-surveillance and body-modification, mediated by the Daily Sun and other tabloid and social media platforms, could be read as a local iteration of a global postfeminist subjectivity. However, the widespread social opprobrium she faces must be accounted for: Using Connell’s model of the gender order together with a coloniality frame, I argue that northern critiques of postfeminism omit to consider the forms of patriarchy established by colonialism in southern locales such as South Africa. The local patriarchal gender order, made visible within the tabloid reportage, provides the context within which the meaning of Zodwa Wabanu’s contemporary postfeminist identity is constructed. I examine a range of Zodwa Wabantu’s (self)representations in Daily Sun and other digital media in the light of this context, and conclude that a close examination of the local gender order assists in understanding the limits of postfeminism’s hegemony.
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- Date Issued: 2021
Bridging through “women’s work"
- Authors: Magadla, Siphokazi
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/298650 , vital:57724 , xlink:href="https://doi.org/10.1080/14616742.2020.1863158"
- Description: Bodomo’s bridge theory describes and predicts the long-term implications of African migrants’ activities and settlement in China. Drawing on research with African retail traders, university students, and corporate executives in China, I show that the bridge theory illuminates how African women and men rationalize their decisions to migrate to China within the context of the rise of Asia. Drawing on the literature regarding African women and work, I explain that structural economic conditions now force more Africans into economic sectors such as trade work that historically were dominated by African women. I demonstrate that African women’s roles as economic providers for their families and children in other sectors, such as university students and company executives, provide evidence of the continued “matricentric” nature of African households that rely on women’s economic productivity. I also examine the possibilities and limitations of building long-standing networks that shape African migrant settlement in China. I show that the historical theorization that characterizes global mobility as male – particularly regarding Africans – has contributed to the misrecognition of African women’s multiple activities in China.
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- Date Issued: 2021
Case Study For Linking Water Quality License Conditions With Resource Quality Objectives For The Leeutaaiboschspruit Industrial Complex Situated Within The Vaal Barrage Catchment Volume 1
- Authors: Odume, Oghenekaro N , Slaughter, Andrew R , Griffin, Neil J , Chili, Asanda
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , report
- Identifier: http://hdl.handle.net/10962/438074 , vital:73433 , ISBN 978-0-6392-0224-2 , https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/TT 838-1 final web.pdf
- Description: In South Africa, the resource-directed measures (RDM) and the source-directed con-trols (SDC) are the two complementary strategies designed to ensure that water resources are used and protected. The RDM are directed at water resources to en-sure their protection, and include the Water Resource Classification System (WRCS), the classification of every significant water resource, the determination of the re-serve and the setting of resource quality objectives (RQOs). On the other hand, the SDC are measures imposed to restrict and control the use of water resources, not only in terms of ensuring water resource protection, but also in terms of ensuring that water resources are equitably allocated and are used efficiently. Water use li-cencing (WUL) is an example of an SDC instrument.
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- Date Issued: 2021
Cereal stem borer (Lepidoptera) assemblage structure in a sub-tropical agro-ecosystem, Eastern Cape Province, South Africa
- Authors: Niba, AS. , Mdazu, S.
- Date: 2021
- Subjects: Cereal products Stem borers Article
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/6958 , vital:52619 , xlink:href="https://doi.org/10.1080/0035919X.2021.1893861"
- Description: Insect pests, especially lepidopterous stem borers, cause significant losses to cereal production at local and global scales. The borer species associated with cultivated grain cereals and alternative wild host plants were identified at three elevation gradients in the former Transkei area of the Eastern Cape Province, South Africa. Stem borer sampling was undertaken during maize crop and non-crop seasons in Port St Johns (PSJ), Mthatha and Elliot, sites that differ in elevation above sea level, annual precipitation and temperature. Morphologically identical borers retrieved from each sampling unit were recorded, processed and reared to adult stage for identification at an ambient temperature range of 25–28°C and a relative humidity range of 65–80%. Specimens were sorted first into morphospecies (MS1–MS6) based on external morphological characteristics. Six stem borer species (Busseola fusca, Sesamia calamistis, Eldana saccharina, Chilo orichalcocili, Chilo sacchariphagus and Chilo partellus) were collected during the survey. E. saccharina and C. orichalcocili were absent in PSJ; in Elliot, E. saccahrina occurred in very low numbers whereas C. partellus was absent. Busseola fusca was more abundant at high altitude (i.e. Elliot). Borer community structure in the study showed similarity between Mthatha and Elliot. Species richness and abundance across study sites were not statistically significant (P > 0.05). The study provides information on borer species occurrence in the study area, and techniques to identify larval stages for effective control by local farmers and extension workers. When designing strategies for borer control, elevation may not be a major concern at this spatial scale.
- Full Text:
- Date Issued: 2021
Cereal stem borer (Lepidoptera) assemblage structure in a sub-tropical agro-ecosystem, Eastern Cape Province, South Africa
- Authors: Niba, AS. , Mdazu, S.
- Date: 2021
- Subjects: Cereal products Stem borers Article
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/6948 , vital:52620 , xlink:href="https://doi.org/10.1080/0035919X.2021.1893861"
- Description: Insect pests, especially lepidopterous stem borers, cause significant losses to cereal production at local and global scales. The borer species associated with cultivated grain cereals and alternative wild host plants were identified at three elevation gradients in the former Transkei area of the Eastern Cape Province, South Africa. Stem borer sampling was undertaken during maize crop and non-crop seasons in Port St Johns (PSJ), Mthatha and Elliot, sites that differ in elevation above sea level, annual precipitation and temperature. Morphologically identical borers retrieved from each sampling unit were recorded, processed and reared to adult stage for identification at an ambient temperature range of 25–28°C and a relative humidity range of 65–80%. Specimens were sorted first into morphospecies (MS1–MS6) based on external morphological characteristics. Six stem borer species (Busseola fusca, Sesamia calamistis, Eldana saccharina, Chilo orichalcocili, Chilo sacchariphagus and Chilo partellus) were collected during the survey. E. saccharina and C. orichalcocili were absent in PSJ; in Elliot, E. saccahrina occurred in very low numbers whereas C. partellus was absent. Busseola fusca was more abundant at high altitude (i.e. Elliot). Borer community structure in the study showed similarity between Mthatha and Elliot. Species richness and abundance across study sites were not statistically significant (P > 0.05). The study provides information on borer species occurrence in the study area, and techniques to identify larval stages for effective control by local farmers and extension workers. When designing strategies for borer control, elevation may not be a major concern at this spatial scale.
- Full Text:
- Date Issued: 2021
Chave Chemutengure Vhiri Rengoro : Husarungano Nerwendo Rwengano Dzevashona
- Authors: Mabasa, Ignatius T
- Date: 2021
- Subjects: Ethnology -- Zimbabwe , Zimbabwe -- Folklore , Shona (African people) -- Folklore , Ethnoscience , Decolonization in literature , Decolonization -- Africa , Autoethnography , Chemutengure , Subaltern
- Language: Shona
- Type: text , Thesis , Doctoral , PHD
- Identifier: http://hdl.handle.net/10962/174198 , vital:42454 , http://doi.org/10.21504/10962/174198
- Description: Tsvakurudzo ino inyaya yangu sasarungano nemunyori weChiShona, asiwo iri nyaya yevanhu veChiShona. Inyaya yekurerwa kwandakaitwa nengano, ndikaona ngano dzakandirera dzichipinzwa muzvikoro, dzichisangana nechirungu, dzichifambidzana nechirungu, nekuzopedzisira dzazvara mimwe misambo yengano. Basa rino maonero angu ndichishandisa nzira yetsvakurudzo inonzi husarungano, kureva muono wasarungano. Izvi zvinoreva kududzira nekutsanangura, kufungisisa nekupenengura humhizha hunowanikwa mutsika nemagariro angu, sasarungano ari kupfuurira mberi nekuita ngano munyika yazara chirungu. Naizvozvo, ini ndini musoro wenyaya yandiri kutaura, asiwo ndirini zvakare muiti wetsvakurudzo. Ndichishandisa zvandakasangana nazvo, nezvandinofunga nekuona sasarungano – ndinodzokera kuchimbo chinotaura nyaya yevaShona pakapinda vachena munyika yeZimbabwe. Ndinotsanangura zvinoreva Chemutengure, uye nekukosha kwacho mukufambisa ruzivo, mashoko nekutsanangura hupenyu hwedu sevanhu vatema vakanga vakadzvanyiriwa. Chemutengure mafungiro, imhenenguro, iyambiro nehungwaru. Ndinotsanangura ruzivo rwevanhu vangu nekushanduka kwarwo kwakakonzerwa nechirungu. Ndinoita izvi ndichipenengura ngano, mabhuku, nziyo, mafungiro nezvimwe zvimutengure zvakatakura ngano. Otoetinogirafu iyo yandichapa zita rekuti husarungano imhando yekuvhiya uchiita tsvakurudzo, uye inowanikwa pakati pehumhizha hwekunyora nyaya nekupenengura zvine chekuita nehumhizha hwetsika nemagariro evanhu. Husarungano hunovhurira musiwo vanhu vanowanzovharirwa kunze netsvakurudzo dzinoitwa mumayunivhesiti dzine mitauro isiri yavo uyewo dzimwe nguva isinganzwisisike zviri nyn’ore. Husarungano hunoshandisa rondedzero nengano kuti zvinhu zvinosanganisira hukama nezvakasanganikwa nazvo nevanhu zvinzwisisike, panguva imwechete pachiumbwa hukama pakati penguva dzakare nazvino, hukama pakati pevanoita tsvakurudzo nevavari kuita tsvakurudzo pamusoro pavo, hukama pakati pevanyori nevaverengi, vanasarungano nevateereri vengano (Adams nevamwe, 2015). Tsvakurudzo ino haisi kuzopedza zvese zvinofanira kutaurwa pamusoro pengano, tsika nemagariro evanhu vatema, kunyorwa kwemabhuku nezvimwe zvakawanda zvainobata nekutarisa, asi riripo kuratidza simba nehupfumi huri muruzivo rwevaShona rwuri kurariswa muberere memba, chirungu chichirariswa mumba. Shanduko yandiri kutarisa mubasa rino inoda kuti isu vanhu vatema tisarambe tichiverengera kuti tirongeke nekuronga mafambiro nemararamiro achaita ruzivo rwedu munyika iri kukoshesa ruzivo, maitiro nezvinhu zvinogadzirwa nevarungu. Kana tikasaronga kuti tipembedze nekuwanisa ruzivo rwedu mukana, tichaita mufakose – kurasikirwa nezvedu, nekusakwana kana kunyatsonzwisisa zvevamwe zvatiri kukoshesa. Ruzivo rwandakashandisa mubasa rino rwunosanganisira zvakaitika kwandiri kubva pandakatanga kuziva ngano dzandakaudzwa nambuya vangu, kubatsirwa kwangu nengano kuchikoro, kuve munyori wemabhuku, nekuenda kwangu mhiri kwemakungwa sasarungano. Zvakarewo ndiri kutarisa ngano dzakaunganidzwa nekunyorwa nemamishenari, ngano dzakanyorwa kare muNative Afffairs Department Annual (NADA), ngano dzakaitwa senziyo, ngano dzakaitwa neLiterature Bureau, nengano dzandave kuita dzemanon-governmental organisations (NGO), panhepfenyuro, paTwitter nezvimwe zvimutengure zvakasiyana-siyana. Hupfumi huri mungano, mazano ekuri kuenda ngano dzedu, nezvinoreva chemutengure senzira yemafungiro zvinobuda mutsvakurudzo ino. Chitsauko 1 ndicho chinozama kutevedza nzira yekuita tsvakurudzo inozivikanwa, asi Chitsauko 2 inyunyuto inoburitsa mukundo une chirungu sekuunzwa kwachakaitwa naCecil John Rhodes. Chitsauko 3 chinotambanudza nekujekesa kukosha kwechimbo Chemutengure, uyewo nekuti sezano, chemutengure chinotibata sei nhasi uno. Chitsauko 4 chinoronda nzira dzakafamba nadzo ngano dzekunze dzichipinda matiri, uyewo nezvakaitwa nengano dzedu pamusoro peshanduko yakanga yauya. Chitsauko 5 chinopa mienzaniso yezviteshi zvakamira ngano dzevatema padzakabva mumisha dzichienda kuzvikoro kusvika dzazove muzvimwe zvimutengure zvakadziendesa kure nasarungano. Chitsauko 6 chinotarisa dambudziko rine chirungu muhupenyu hwevanhu vatema, nekukosha kwekudada nerudzi rwedu. Chitsauko 7 chinopeta basa chichipa mazano, chichiratidza kuti ngano hadzifanire kufa nekuti dzakagara dzine simba rekufambirana nenguva. , This research is my story as a Shona folklorist and creative writer, but it is also the story of the Shona people. It is a story of how I am “a child” of storytelling, and how the stories that raised me got appropriated and incorporated into the colonial school system where they converged and mixed with western forms of storytelling to create hybrids. As a storyteller I use autoethnography – which offers an insider’s perspective - to interpret and explain, to reflect and analyse the art of storytelling in my culture. The alienation of indigenous knowledge and cultural practices – specifically storytelling, is what necessitates the use of autoethnography for this study. Autoethnography is a qualitative research method of writing and storytelling where the researcher is the subject and the researcher's experiences are the data. I, being a Shona storyteller and creative writer, will systematically journey back and analyse personal experiences in order to make sense of the Shona people’s cultural experiences. The research process will see me running away from depending on other people’s records about my people’s cultural history. Instead, I traverse back in time to consult and extract a theory from the Shona song called Chemutengure from around 1890 that tells the story of British colonisation from the perspective of the colonised. I theorise and explain Chemutengure’s pedagogical and epistemological significance in critiquing the plight of Africans suffering contact-induced change. I apply the Chemutengure theory to folktales, books, songs, paradigms and other agents that played an active role in producing new forms of storytelling and worldviews. Autoethnography is a type of research method that blends engaging creative writing and analysis of cultural experiences. It opens doors of research to the subalterns who are usually shut out by research that is done in universities. “Rather than producing esoteric, jargon-laden texts, many auto-ethnographers recognize a need to speak also to nonacademic audiences,” (Adams et al, 2015: 42) employing narrative and story-telling to give meaning to identities, relationships, and experiences, and to create relationships between past and present, researchers and participants, writers and readers, tellers and audiences, (Adams et al, 2015:23). This research will not exhaust all that needs to be explored and said about Shona folktales, creativity and culture, or its literature and the many cultural aspects it looks at. Rather, it seeks to highlight, decolonize and deconstruct colonial mentalities, while emancipating the Shona worldview that has been put on leash by colonialism and western capitalistic tendencies. The study also looks at positive change that occurs when cultures inform one another, but without turning a blind eye to the lack of mutuality and how the logic of capitalism has left Africa hemorrhaging ideologically. Drawing from personal experiences when I listened to my grandmother’s stories, the study looks at the influence of folktales on my creative writing career. I reflect on my experiences as a Fulbright Scholar, as well as my Canadian experiences as storyteller and writer-in-residence at the University of Manitoba. Besides analysing stories written by missionaries in early Shona school readers, I also discuss folktales published in the Native Affairs Department Annual (NADA); the folktales performed as songs; the comic tales published by the Literature Bureau; tales developed for private institutions, government and non-governmental organisations; stories on radio, Twitter and many other forms. Besides giving the subaltern a voice, this research attempts to artistically demonstrate the power and versatility of the Shona folktale, as well as the genre’s potential for growth and development. Chapter 1 introduces the autoethngraphy method as well as what I hope to achieve through the methodology and style of writing. Chapter 2 is a conversation between a representative of the colonised and Cecil John Rhodes the imperialist. Besides pointing out imperialism’s damage to indigenous identities, the chapter discusses how Africa and Europe’s paradigms are diametrically conflicting. Chapter 3 introduces, explains and analyses the song/theory Chemutengure, and how it applies to the condition of the native in postcolonial Africa today. Chapter 4 tracks the trajectory of foreign tales in Zimbabwe, and how they influenced native folktales. The response of local tales is also critiqued. Chapter 5 looks at the milestones in the structural transformation of indigenous folktales, and how they were appropriated and hitched a ride in the wagon of change. Chapter 6 is a reflection on the impact of westernisation and globalisation in the lives of Africans, and how confused the native has become without his cultural anchor. Chapter 7 concludes by acknowledging the inevitability of change, and suggests how cultural practices and perspectives must respond to social change so as to remain relevant.
- Full Text:
- Date Issued: 2021
Clinical outcomes of hospitalised COVID-19 patients at Mthatha Regional Hospital, Eastern Cape, South Africa: A retrospective study
- Authors: Kaswa, Ramprakash , Yogeswaran, Parimalaranie , Cawe, Busisiwe
- Date: 2021
- Subjects: COVID-19 Diabetes Hypertension Diseases Article
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/7330 , vital:53402 , xlink:href="https://doi.org/10.4102/safp.v63i1.5253"
- Description: Background: Coronavirus disease 2019 (COVID-19) is a public health crisis that threatens the current health system. The sudden expansion in the need for inpatient and intensive care facilities raised concerns about optimal clinical management and resource allocation. Despite the pressing need for evidence to make context-specific decisions on COVID-19 management, evidence from South Africa remained limited. This study aimed to describe the clinical characteristics and outcomes of COVID-19 hospitalised patients. Methods: A retrospective cross-sectional study design was used to evaluate the clinical outcomes of hospitalised adult patients (≥ 18 years old) with laboratory-confirmed COVID-19 illness at Mthatha Regional Hospital (MRH), Eastern Cape. Results: Of the 1814 patients tested for COVID-19 between 20 March 2020 and 31 July 2020 at MRH, two-thirds (65.4%) were female. About two-thirds (242) of the 392 patients (21.6%) who tested positive for this disease were hospitalised and one-third (150) were quarantined at home. The mean age of the patients tested for COVID-19 was 42.6 years and there was no difference between males and females. The mean age of hospitalised patients was 55.5 years and the mean age of hospitalised patients who died (61.3 years) was much higher than recovered (49.5 years). Overall, 188 (77.6%) hospitalised patients had clinical comorbidity on admission. Diabetes (36.8%) and hypertension (33.1%) were the most common comorbidities amongst COVID-19 hospitalised patients. Conclusion: The majority of the patients who were hospitalised for COVID-19 were elderly and had high baseline comorbidities. Advance age and underlying comorbidities (diabetes, hypertension and HIV) were associated with high mortality in hospitalised COVID-19 patients. Keywords: COVID-19, diabetes; hypertension; hospitalised; co-morbidity.
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- Date Issued: 2021
Coastal dunefields maintain pre‐Holocene genetic structure in a rocky shore red alga
- Authors: Mmonwa, Kolobe L , Barker, Nigel P , McQuaid, Christopher D , Teske, Peter R
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/444784 , vital:74298 , https://doi.org/10.1111/jpy.13182
- Description: Most intertidal algae have limited dispersal potential, and areas that lack hard substratum suitable for attachment are thus expected to isolate regional populations from each other. Here, we used nuclear and mitochondrial genetic data to compare genetic structure in two co‐distributed intertidal red algae with different dispersal potential along the South African coastline. Gelidium pristoides is divided into a south‐eastern and a south‐western evolutionary lineage separated by extensive, continuous sandy shoreline habitat adjacent to coastal dunefields. In contrast, Hypnea spicifera is genetically homogeneous throughout its range. In G. pristoides, the genetic breaks are associated with contemporary coastal dunefields. The age of the divergence event suggests that this may reflect the effect of older dispersal barriers, and that genetic structure was subsequently maintained by the formation of contemporary coastal dunefields.
- Full Text:
- Date Issued: 2021
Coastal pH variability and the eco-physiological and behavioural response of a coastal fish species in light of future ocean acidification
- Authors: Edworthy, Carla
- Date: 2021
- Subjects: Ocean acidification , Diplodus capensis (Blacktail) , Diplodus -- South Africa -- Algoa Bay , Diplodus -- Metabolism , Diplodus -- Food , Diplodus -- Larvae , Marine ecology -- South Africa -- Algoa Bay , Carbon dioxide -- Physiological effect , Respiration -- Measurement
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/176793 , vital:42759 , 10.21504/10962/176793
- Description: Ocean acidification (OA) is a global phenomenon referring to a decrease in ocean pH and a perturbation of the seawater carbonate system due to ever-increasing atmospheric CO2 concentrations. In coastal environments, identifying the impacts of OA is complex due to the multiple contributors to pH variability by coastal processes, such as freshwater inflow, upwelling, hydrodynamic processes, and biological activity. The aim of this PhD study was to quantify the local processes occurring in a temperate coastal embayment, Algoa Bay in South Africa, that contribute to pH and carbonate chemistry variability over time (monthly and 24-hour) and space (~10 km) and examine how this variability impacts a local fish species, Diplodus capensis, also commonly known as ‘blacktail’. Algoa Bay, known for its complex oceanography, is an interesting location in which to quantify carbonate chemistry variability. To assess this variability, monitoring sites were selected to coincide with the Algoa Bay Sentinel Site long-term ecological research (LTER) and continuous monitoring (CMP) programmes. The average pH at offshore sites in the bay was 8.03 ± 0.07 and at inshore sites was 8.04 ± 0.15. High pH variability (~0.55–0.61 pH units) was recorded at both offshore (>10 m depth) and inshore sites (intertidal surf zones). Many sites in the bay, especially the atypical site at Cape Recife, exhibit higher than the average pH levels (>8.04), suggesting that pH variability may be biologically driven. This is further evidenced by high diurnal variability in pH (~0.55 pH units). Although the specific drivers of the high pH variability in Algoa Bay could not be identified, baseline carbonate chemistry conditions were identified, which is necessary information to design and interpret biological experiments. Long-term, continuous monitoring is required to improve understanding of the drivers of pH variability in understudied coastal regions, like Algoa Bay. A local fisheries species, D. capensis, was selected as a model species to assess the impacts of future OA scenarios in Algoa Bay. It was hypothesized that this temperate, coastally distributed species would be adapted to naturally variable pH conditions and thus show some tolerance to low pH, considering that they are exposed to minimum pH levels of 7.77 and fluctuations of up to 0.55 pH units. Laboratory perturbation experiments were used to expose early postflexion stage of D. capensis to a range of pH treatments that were selected based on the measured local variability (~8.0–7.7 pH), as well as future projected OA scenarios (7.6–7.2 pH). Physiological responses were estimated using intermittent flow respirometry by quantifying routine and active metabolic rates as well as relative aerobic scope at each pH treatment. The behavioural responses of the larvae were also assessed at each pH treatment, as activity levels, by measuring swimming distance and speed in video-recording experiments, as well as feeding rates. D. capensis had sufficient physiological capacity to maintain metabolic performance at pH levels as low as 7.27, as evidenced by no changes in any of the measured metabolic rates (routine metabolic rate, active metabolic rate, and relative aerobic scope) after exposure to the range of pH treatments (8.02–7.27). Feeding rates of D. capensis were similarly unaffected by pH treatment. However, it appears that subtle increases in activity level (measured by swimming distance and swimming speed experiments) occur with a decrease in pH. These changes in activity level were a consequence of a change in behaviour rather than metabolic constraints. This study concludes, however, that based on the parameters measured, there is no evidence for survival or fitness related consequences of near future OA on D. capensis. OA research is still in its infancy in South Africa, and the potential impacts of OA to local marine resources has not yet been considered in local policy and resource management strategies. Integrating field monitoring and laboratory perturbation experiments is emerging as best practice in OA research. This is the first known study on the temperate south coast of South Africa to quantify local pH variability and to use this information to evaluate the biological response of a local species using relevant local OA scenarios as treatment levels for current and near future conditions. Research on local conditions in situ and the potential impacts of future OA scenarios on socio-economically valuable species, following the model developed in this study, is necessary to provide national policy makers with relevant scientific data to inform climate change management policies for local resources.
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- Date Issued: 2021
Constraints on improving higher education teaching and learning through funding
- Authors: Moyo, Temwa , McKenna, Sioux
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/185854 , vital:44440 , xlink:href="http://dx.doi.org/10.17159/sajs.2021/7807"
- Description: In the midst of massification, targeted funding has been used in various countries to address inefficiencies in teaching and learning. In South Africa, arguments have been made for significant investments to be made and the University Capacity Development Grant (UCDG) in particular is being used as a driver for improved outputs. Prior to its implementation in 2018, the UCDG comprised the Research Development Grant and the Teaching Development Grant. The Teaching Development Grant was intended to address low retention and throughput rates and ZAR5.5 billion was spent to this end over a 12-year period. The analysis presented here of all Teaching Development Grant budget plans and progress reports from 2007 to 2015 shows that the undifferentiated implementation of the Teaching Development Grant within a differentiated sector limited its potential for system-wide gains. Institutions without adequate resources tended to divert Teaching Development Grant funds to attend to backlogs rather than to address teaching and learning practices and such universities lost much of their allocation through the withholding of unspent funds. This blanket practice addressed the symptoms of underspending but not the structural, cultural and agential mechanisms that led to such under-expenditure. Uneven access to the limited teaching development expertise also impacted on the use of the grant. This call for a context-based approach to funding has been identified as a key success factor in grant interventions in both African and European universities. We recommend a sector-wide response in the form of a national body or plan for the benefit of all universities and investment in financial management enhancement. The study contributes to a better understanding of how government funding interventions can achieve intended goals. The study calls for a more contextualised approach to funding and to greater collaboration across the sector to maximise limited capacity.
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- Date Issued: 2021
Covid-19 and the restrictive measures: The national security conundrum for Zimbabwe
- Authors: Mugari, Ishmael , Obioha, Emeka E.
- Date: 2021
- Subjects: COVID-19 (Disease) National security Article
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/6926 , vital:52571 , xlink:href="https://10.1080/10246029.2021.1972015"
- Description: The emergence of the COVID-19 pandemic at the onset of the year 2020 brought unprecedented suffering to humanity. Economic activities in virtually all nations across the globe were brought to a shuddering halt, with the third world suffering the worst effects on the economic front. The health security of nations across the globe was shaken, as nations came to terms with the surging health needs for the infected citizens. In order to grapple with the pandemic, nations took drastic measures, chief among them being the implementation of lockdowns, coupled with harsh restrictions. These measures, however, came at a cost. This paper explores the impacts of the restrictive measures that were implemented by the Zimbabwean government to combat COVID-19 pandemic. The paper interrogates these measures in the context of the national security discourse. In the analysis, the paper also makes reference to South Africa- a more developed nation and Zimbabwe’s neighbour. Keywords: COVID-19 , national security, health security, lockdown
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- Date Issued: 2021
Creating the Ideal Push-Pull System for Electrocatalysis A Comparative Study on Symmetrical and Asymmetrical Cardanol-based Cobalt Phthalocyanines
- Authors: Nkhahle, Reitumetse , Nyokong, Tebello
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/${Handle} , vital:44452 , xlink:href="https://doi.org/10.1002/elan.202060019"
- Description: A symmetrical cardanol-based cobalt phthalocyanine (Pc) along with its asymmetrical acid-based derivatives were synthesized and applied in the electrocatalysis of hydrazine. Despite the inhibition of electron movement by the bulky cardanol-based substituent throughout the series of molecules, an ideal combination of substituents was established in GCE-3 (2,9,16-tris(3- pentadecylphenoxy)-23-mono propionic acid phthalocyanato cobalt (II)) where a limit of detection (LoD) value of 5.10 μM (signal to noise ratio=5) was recorded for the detection of hydrazine. The results obtained serve as an illustration that the combination of electron-donating and electron-withdrawing substituents has a significant influence on the complete functioning of the phthalocyanine molecule(s) being investigated.
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- Date Issued: 2021
Creative Cities and Regional Development: The Case of Makhanda and the Creative City Project
- Authors: Campbell, Guy John
- Date: 2021
- Subjects: To be assigned
- Language: English
- Type: thesis , text , Masters , MCOM
- Identifier: http://hdl.handle.net/10962/174448 , vital:42478
- Description: Thesis (MSc)--Rhodes University, Faculty of Commerce, Economics and Economic History, 2020
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- Date Issued: 2021
Crossing the border from candidate to supervisor: The need for appropriate development
- Authors: Motshoane, Puleng , McKenna, Sioux
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/185876 , vital:44442 , xlink:href="https://doi.org/10.1080/13562517.2021.1900814"
- Description: Postgraduate education has grown enormously worldwide, which has led to supervisors being expected to take on a supervisor's role immediately upon graduation. But crossing the border from being a doctoral candidate to becoming a doctoral supervisor entails significant shifts in identity and an understanding of postgraduate pedagogy and institutional expectations. This paper argues that supervision development opportunities are crucial, but they need to be contextualised and include critical key agents with some institutional authority if they are to be deemed worthwhile and effect change. An online survey completed by 186 participants from across institutional types and disciplines in South Africa is analysed using Archer's social realism to provide insights into how emerging supervisors are currently supported. The resultant recommendations on supervision development could contribute to more confident border crossing by emerging supervisors.
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- Date Issued: 2021
Current and future biological control efforts against Solanum mauritianum (Solanaceae) in South Africa
- Authors: Venter, Nic , Cowie, Blair W , Olckers, Terence , Byrne, Marcus J
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/414349 , vital:71138 , xlink:href="https://hdl.handle.net/10520/ejc-ento_v29_n3_a14"
- Description: Solanum mauritianum Scop. (Solanaceae), colloquially referred to as bugweed in South Africa, remains a widespread invasive tree of global significance. Although biological control (biocontrol) efforts were undertaken from 1984 -2003 in South Africa, the programme eventually only released two agents, the sap-sucking lace bug Gargaphia decoris Drake (Hemiptera: Tingidae) and flowerbud-feeding weevil Anthonomus santacruzi Hustache (Coleoptera: Curculionidae). To date, these agents have been relatively ineffective in controlling S. mauritianum, largely due to low establishment success due to climatic incompatibility in relation to the widespread distribution of S. mauritianum. This has prompted the revival of S. mauritianum biocontrol research in 2018, with the programme focused largely on sourcing additional agents from climatically suitable regions in the plant’s native range in South America. Climate matching between cooler regions of South Africa and known S. mauritianum sites in South America identified Uruguay as a promising source of new agents. Field collections in Uruguay focused mainly on Anthonomus spp. but included stem-boring and shoot-galling weevils. Low incidence in the field and difficulties in culturing candidate species temporarily precluded research into stem-boring and shoot-galling candidates, but the rearing and assessment of the flowerbud-feeding weevil Anthonomus morticinus Clark (Coleoptera: Curculionidae) is ongoing. Host-specificity testing of A. morticinus has thus far confirmed a narrow host range, suggesting it has potential as a new agent.
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- Date Issued: 2021
Defended subjectivity in service-learning:a psychosocial analysis of students’ talk about service-learning in psychology
- Authors: Haselau, Tracey Laura
- Date: 2021
- Subjects: Service learning -- Case studies -- South Africa -- Makhanda , Rhodes University -- Students -- Attitudes , Psychology students -- Attitudes -- South Africa -- Makhanda
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/170810 , vital:41962 , 10.21504/10962/170810
- Description: The purpose of this qualitative study was to analyse students’ talk about their service-learning experiences in psychology, in South Africa, from a psychosocial perspective. The research aims to identify dominant and subjugated discourses about service-learning in psychology, and to explore why students invest in particular discourses over others. Furthermore, the research aims to explore the intersubjective contexts that mediate students’ talk about their service-learning and their emotional investments in the discourses employed in their talk, drawing on the concept of mentalization. Eight psychology students were interviewed toward the end of their participation in a service-learning psychology honours course. Transcripts from the interviews as well as entries from students’ reflective journals were analysed using a psychosocial methodology. The key findings from this research point to the ways in which students oscillate between employing two competing sets of discourses about their service learning. At times, students drew on what I have referred to as a ‘discourse of rapture’, characterised by fascination with the ‘other’ and the maintenance of power imbalances. This discourse draws on a liberal traditional discourse of learning and a charity discourse of service-learning. In other parts of their talk, students draw on what I have called a ‘discourse of ruptura’, characterised by an inward curiosity about the outward fascination with the ‘other’. This discourse draws on constructivist accounts of service-learning. Findings suggest that students’ emotional investments in discourses of service-learning are mediated by defensive positions caused by the anxieties incurred in service-learning contexts. An important consideration to take forward from this research is the way in which anxieties in service-learning experiences may be contained (or not), and to be aware of the problematic outcomes that may arise from not containing anxieties, such as the perpetuation of prejudicial attitudes and othering. The intersectionality of ‘race’ and disability in the specific service-learning programme under investigation in this study is an important consideration in implementing careful supervision of programmes such as this one, so that students’ rapture with the ‘other’ is not compounded and reinforced by the service-learning experience.
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- Date Issued: 2021
Design patterns and software techniques for large-scale, open and reproducible data reduction
- Authors: Molenaar, Gijs Jan
- Date: 2021
- Subjects: Radio astronomy -- Data processing , Radio astronomy -- Data processing -- Software , Radio astronomy -- South Africa , ASTRODECONV2019 dataset , Radio telescopes -- South Africa , KERN (omputer software)
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/172169 , vital:42172 , 10.21504/10962/172169
- Description: The preparation for the construction of the Square Kilometre Array, and the introduction of its operational precursors, such as LOFAR and MeerKAT, mark the beginning of an exciting era for astronomy. Impressive new data containing valuable science just waiting for discovery is already being generated, and these devices will produce far more data than has ever been collected before. However, with every new data instrument, the data rates grow to unprecedented quantities of data, requiring novel new data-processing tools. In addition, creating science grade data from the raw data still requires significant expert knowledge for processing this data. The software used is often developed by a scientist who lacks proper training in software development skills, resulting in the software not progressing beyond a prototype stage in quality. In the first chapter, we explore various organisational and technical approaches to address these issues by providing a historical overview of the development of radioastronomy pipelines since the inception of the field in the 1940s. In that, the steps required to create a radio image are investigated. We used the lessons-learned to identify patterns in the challenges experienced, and the solutions created to address these over the years. The second chapter describes the mathematical foundations that are essential for radio imaging. In the third chapter, we discuss the production of the KERN Linux distribution, which is a set of software packages containing most radio astronomy software currently in use. Considerable effort was put into making sure that the contained software installs appropriately, all items next to one other on the same system. Where required and possible, bugs and portability fixes were solved and reported with the upstream maintainers. The KERN project also has a website, and issue tracker, where users can report bugs and maintainers can coordinate the packaging effort and new releases. The software packages can be used inside Docker and Singularity containers, enabling the installation of these packages on a wide variety of platforms. In the fourth and fifth chapters, we discuss methods and frameworks for combining the available data reduction tools into recomposable pipelines and introduce the Kliko specification and software. This framework was created to enable end-user astronomers to chain and containerise operations of software in KERN packages. Next, we discuss the Common Workflow Language (CommonWL), a similar but more advanced and mature pipeline framework invented by bio-informatics scientists. CommonWL is supported by a wide range of tools already; among other schedulers, visualisers and editors. Consequently, when a pipeline is made with CommonWL, it can be deployed and manipulated with a wide range of tools. In the final chapter, we attempt something unconventional, applying a generative adversarial network based on deep learning techniques to perform the task of sky brightness reconstruction. Since deep learning methods often require a large number of training samples, we constructed a CommonWL simulation pipeline for creating dirty images and corresponding sky models. This simulated dataset has been made publicly available as the ASTRODECONV2019 dataset. It is shown that this method is useful to perform the restoration and matches the performance of a single clean cycle. In addition, we incorporated domain knowledge by adding the point spread function to the network and by utilising a custom loss function during training. Although it was not possible to improve the cleaning performance of commonly used existing tools, the computational time performance of the approach looks very promising. We suggest that a smaller scope should be the starting point for further studies and optimising of the training of the neural network could produce the desired results.
- Full Text:
- Date Issued: 2021