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Policy and practice of inclusive education for mainstream secondary teachers supporting learners with physical disabilities in the Lower Shire, Malawi

  • Authors: De Souza, Ben
  • Date: 2021
  • Subjects: Children with disabilities -- Education (Secondary) -- Malawi , Children with disabilities -- Education -- Government policy -- Malawi , Children with disabilities -- Legal status, laws, etc. -- Malawi , Inclusive education -- Malawi , Teachers -- Training of -- Malawi , High School teachers -- Malawi -- Attitudes
  • Language: English
  • Type: Thesis , Masters , MEd
  • Identifier: http://hdl.handle.net/10962/171254 , vital:42038
  • Description: The Government of Malawi and its education partners are currently implementing the National Education Policy (2016) and the National Strategy on Inclusive Education (2017-2021). My study explored how mainstream secondary teachers interpret policies and strategies, and transition to the practice of supporting learners with physical disabilities. Previous studies revealed policy-to-practice disparities in the Malawian inclusive secondary education but did not proffer teacher-oriented strategies that can mitigate the disparities and enhance inclusive education. My study argued that effective strategies that could lessen policy-to-practice mismatches and advance inclusive education primarily rest with mainstream teachers, as they mediate policy and practice. This study drew on Clough and Corbett’s disability studies critique and Urie Bronfenbrenner’s bioecological systems perspective to form theoretical and analytical frameworks for understanding the problem and discussing the findings. The study generated primary data from the Lower Shire districts of Chikwawa and Nsanje in Malawi. Thirty-three teachers, randomly selected from four schools, responded to questionnaires. In-depth, face to face interviews were conducted with purposely selected teachers from the same four schools. The study also generated secondary data from a review of policy documents. The findings showed that policy directives are shifting inclusive education from social perspectives to political perspectives, whereby mainstream teachers regard national policies and strategies as political responses to demands for inclusion. The findings further showed that teachers’ practices are moving away from the provision of special needs to the promotion of inclusive needs, whereby inclusive education benefits all learners. The study found that some teachers are resisting inclusive education, and would like learners with physical disabilities to return to special schools, thus controverting policy directives. As a way forward, this study recommended that future policy formulation and implementation in the Malawian mainstream secondary education should consider the bioecological systems approach, whereby policymakers systematically interact with the mainstream secondary teachers to improve their perspectives, competencies and practices on inclusive education.
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  • Date Issued: 2021

Population genetics of invasive and native Nymphaea mexicana Zuccarini: Taking the first steps to initiate a biological control programme in South Africa

  • Authors: Reid, Megan K , Naidu, Prinavin , Paterson, Iain D , Mangan, Rosie , Coetzee, Julie A
  • Date: 2021
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/419375 , vital:71638 , xlink:href="https://doi.org/10.1016/j.aquabot.2021.103372"
  • Description: Nymphaea mexicana Zuccarini (Nympheaceae) (Mexican waterlily) is a rooted floating-leaved aquatic plant native to southern USA and Mexico that has become a problematic invasive alien plant in South Africa. Biological control is considered a desirable management strategy for the plant in South Africa. A good understanding of the genetic structure of invasive populations has been useful in other biological control programmes because taxonomic uncertainty about the target plant can result in natural enemies that are not adapted to the invasive populations being considered as potential agents. For N. mexicana, hybrids exist in the wild and horticultural trade, but identification is difficult, so understanding the genetic structure of populations is required to ensure that potential agents are collected off plants similar to invasive populations in South Africa. ISSR (inter-simple sequence repeats) analysis was used to determine whether invasive N. mexicana populations from South Africa were genetically similar to native range populations from USA or whether they were hybrids. Results from these analyses were matched with the morphotypes of each population based on petal colour, shape, and size. The genotypes suggested by the ISSR analyses corroborated the presence of both hybrid and pure forms of N. mexicana in South Africa. Populations of N. mexicana in the invaded range that are genetically similar to native range populations are more likely to be suitable for biological control, while other populations are likely to be hybrids formed by crossing of parents from the native range or within the horticultural trade, which may present difficulties for management using biocontrol.
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  • Date Issued: 2021

Positively charged styryl pyridine substituted Zn (II) Phthalocyanines for Photodynamic Therapy and Photoantimicrobial Chemotherapy

  • Authors: Magadla, Aviwe , Babu, Balaji , Mack, John , Nyokong, Tebello
  • Date: 2021
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/190600 , vital:45009 , xlink:href="https://doi.org/10.1039/D1DT01047F"
  • Description: Cationic Zn phthalocyanine complexes were synthesized using Knoevenagel reaction starting from a Zn(II) tetrakis(2-formylphenoxy)phthalocyanine (1) to form Zn(II) tetrakis(1-butyl-4-(4-(tetraphenoxy)styryl)pyridin-1-ium) phthalocyanine (2) and Zn(II) tetrakis(4-(4-(tetraphenoxy)styryl)-1-(4-(triphenylphosphonio)butyl)pyridin-1-ium)phthalocyanine (3). The photophysicochemical behaviours of the Pc complexes were assessed. The cationic complexes display high water-solubility and gave moderate singlet oxygen quantum yield in water. The cationic Pcs demonstrate good cellular uptake and photodynamic activity against MCF-7 cells with IC50 values of 8.2 and 4.9 μM for 2 and 3, respectively. The cationic Pcs also demonstrate high photoantimicrobial activity against Escherichia coli with log reductions of 5.3 and 6.0 for 2 and 3, respectively.
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  • Date Issued: 2021

Potential repurposing of four FDA approved compounds with antiplasmodial activity identified through proteome scale computational drug discovery and in vitro assay

  • Authors: Diallo, Bakary N , Swart, Tarryn , Hoppe, Heinrich C , Tastan Bishop, Özlem , Lobb, Kevin A
  • Date: 2021
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/177531 , vital:42830 , https://doi.org/10.1038/s41598-020-80722-2
  • Description: Malaria elimination can benefit from time and cost-efficient approaches for antimalarials such as drug repurposing. In this work, 796 DrugBank compounds were screened against 36 Plasmodium falciparum targets using QuickVina-W. Hits were selected after rescoring using GRaph Interaction Matching (GRIM) and ligand efficiency metrics: surface efficiency index (SEI), binding efficiency index (BEI) and lipophilic efficiency (LipE). They were further evaluated in Molecular dynamics (MD). Twenty-five protein–ligand complexes were finally retained from the 28,656 (36×796) dockings.
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  • Date Issued: 2021

Power, Powerlessness and Radical Protest in Contemporary Cameroonian Popular Music

  • Authors: Sone, Enongene Mirabeau
  • Date: 2021
  • Subjects: Popular music Marginal society Power (Social sciences) Article
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/11260/6896 , vital:52474 , xlink:href="https://doi.org/10.1080/18125980.2021.1947154"
  • Description: The fraught relationship between popular music and the various kinds of power in Africa has stimulated intensive scholarship and encouraged heated discussions on the topic. Of special interest seems to be the multifaceted character of that interrelationship. It is generally agreed that artistic expression is influenced by political power and that the two mutually inform and shape each other. This article examines the themes of power, powerlessness, and protest as they affect political governance in Cameroon, Central Africa, and as they are reflected in Cameroonian popular music. It further shows how popular songs are used to examine fundamental issues of national concern and to criticise the political leadership. The purpose of the article is to demonstrate how popular music can open a window of understanding into the current political process in Cameroon with a view to drawing implications for positive change. Written against the background of new historicism and postcolonial theories, the article is built on the assumption that popular music is a vibrant and dynamic form of oral literature which is shaped by social, economic, and political forces in present-day Cameroon. As a result, popular music has the potential to play a role in influencing a society’s perception and sense of direction. The article concludes by recommending that if the issues of power and marginality in Cameroon are to be addressed more successfully, and if the politically fraught conditions are to be ameliorated, then Cameroonians must be prepared to undergo a radical change of mentality. Keywords: Cameroon; marginalisation; popular music; power; powerlessness; radical protest
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  • Date Issued: 2021

Preformulation characterization and identification of excipients for nevirapine loaded niosomes

  • Authors: Witika, Bwalya A , Walker, Roderick B
  • Date: 2021
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/183126 , vital:43914 , xlink:href="https://doi.org/10.1691/ph.2021.0137"
  • Description: Nevirapine (NVP) is used for the management of HIV/AIDS but must be dosed frequently, exhibits unpredictable bioavailability and a side effect profile that includes hepato- and dermo-toxicity. Niosomes are a colloidal drug delivery system that may be used to overcome the low bioavailability, side effect profile and frequent dosing needed when using conventional drug delivery systems. The compatibility of NVP with sorbitan esters, polysorbate, cholesterol and dihexadecyl phosphate (DCP) was investigated using Differential Scanning Calorimetry (DSC), Scanning Electron Microscopy (SEM), Fourier Transform Infra-red Spectroscopy (FTIR) and X-ray Powder Diffraction (XRPD). Screening studies were undertaken to identify potential excipients that would produce niosomes with target critical quality attributes (CQA) viz, a particle size (PS) less than 1000 nm, a polydispersity index (PDI) less than 0.500 and an entrapment efficiency greater than 90%. The results revealed that sorbitan esters in combination with cholesterol and 5 μmol DCP produced niosomes with the best CQA and Zeta potential (ZP) less than -30 mV which suggests good stability of the niosomes on storage. Sorbitan esters produced the smallest niosomes of less than 400 nm diameter with a PDI less than 0.400 and an entrapment efficiency of more than 78% without cholesterol. The addition of cholesterol and DCP was essential to form niosomes with target CQA.
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  • Date Issued: 2021

Preliminary effectiveness of brief prolonged exposure therapy for ptsd: expanding access to effective therapies

  • Authors: Booysen, Duane D , Kagee, Ashraf
  • Date: 2021
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/454121 , vital:75311 , xlink:href="https://doi.org/10.1177/15346501211017989"
  • Description: Over the last three decades, several empirically supported trauma therapies have been developed to treat post-traumatic stress disorder (PTSD). Yet issues such as access to treatments and dropout are ongoing barriers to adequate dissemination and implementation, especially in low resource settings. To this end, we present results on the preliminary effectiveness of a brief prolonged exposure therapy (PE) for PTSD in South Africa, a low resource setting. Based on a case-series design, seven participants (n = 7) from diverse socio-cultural backgrounds were recruited and started a six-session brief PE for PTSD and co-morbid depression and anxiety. To examine the treatment outcomes, participants were assessed at baseline, during treatment, post-intervention, and at 3-month follow-up. Overall, brief PE reduced symptoms of PTSD, depression, and anxiety from baseline to post-intervention, and at 3-month follow-up. A downward trend in symptoms was evident during treatment, with slight symptom variations during exposure sessions. In conclusion, a six-session brief PE intervention produced positive outcomes for PTSD, depression, and anxiety at two community counseling centers in South Africa. We reflect on the implementation of brief PE in a South African context.
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  • Date Issued: 2021

Prevalence and clinical correlates of substance use disorders in South African Xhosa patients with schizophrenia

  • Authors: Temmingh, Henk , Susser, Ezra , Mall, Sumaya , Campbell, Megan M , Sibeko, Goodman , Stein, Dan J
  • Date: 2021
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/302509 , vital:58203 , xlink:href="https://doi.org/10.1007/s00127-020-01942-5"
  • Description: Purpose: To determine the prevalence of substance use disorders (SUDs) in patients with schizophrenia in a sample from South Africa and compare the clinical and demographic correlates in those with and without co-occurring SUDs. Methods: Patients with schizophrenia were interviewed using the Xhosa version SCID-I for DSM-IV. We used logistic regression to determine the predictors of SUDs. Results: In the total sample of 1420 participants, SUDs occurred in 47.8%, with the most prevalent SUD being cannabis use disorders (39.6%), followed by alcohol (20.5%), methaqualone (6.2%), methamphetamine (4.8%) and other SUDs (cocaine, ecstasy, opioids, 0.6%). Polydrug use occurred in 40%, abuse occurred in 13.5%, and 39.6% had at least one substance dependence diagnosis. Signifcant predictors of any SUD were younger age (41–55 vs. 21–30: OR=0.7, 95% CI=0.5–0.9), male sex (OR=8.6, 95% CI=5.1–14.6), inpatient status (OR=1.7, 95% CI=1.3–2.1), post-traumatic stress symptoms (OR=4.6, 95% CI=1.6–13.3), legal (OR=3.4, 95% CI=2.0–5.5) and economic problems (OR=1.4, 95% CI=1.0–2.0). Methamphetamine use disorders occurred signifcantly less often in the Eastern compared to the Western Cape provinces. Inpatient status and higher levels of prior admissions were signifcantly associated with cannabis and methamphetamine use disorders. Post-traumatic stress symptoms were signifcantly associated with alcohol use disorders. Anxiety disorders were associated with other SUDs. Conclusion: SUDs occurred in almost half of the sample. It is important for clinicians to identify the presence of SUDs as their presence is associated with characteristics, such as male sex, younger age, inpatient status, more prior hospitalisations, legal and economic problems, PTSD symptoms and anxiety.
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  • Date Issued: 2021

Prevalence and determinants of tobacco use amongst South African adults with mental illness in the Eastern Cape

  • Authors: Tindimwebwa, Linda K , Ajayi, Anthony I , Adeniyi, Oladele Vincent
  • Date: 2021
  • Subjects: mental health mental illiness tobacco use Article
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/11260/7278 , vital:53109 , xlink:href="https://doi.org/10.4102/sajpsychiatry.v27i0.1637"
  • Description: Background: Given the physical and mental health consequences of tobacco use amongst individuals with mental illness, it was imperative to assess the burden of tobacco use in this population. Aim: This study examined the patterns and factors associated with tobacco use in individuals attending the outpatient unit. Setting: Cecilia Makiwane Hospital Mental Health Department in Eastern Cape province, South Africa. Methods: Lifetime (ever use) use and current use of any tobacco products were examined in a cross-sectional study of 390 individuals between March and June 2020. A logistic regression was fitted to determine the correlates of lifetime and current use of any tobacco products. Results: The rates of ever use and current use of tobacco products were 59.4% and 44.6%, respectively. Of the participants interviewed, lifetime tobacco use was more prevalent amongst individuals with schizophrenia (67.9%) and cannabis-induced disorders (97.3%) and lower in those with major depressive disorders (36.1%) and bipolar and related disorders (43.5%). Men were six times more likely to have ever used or currently use tobacco products in comparison to women. Also, those who had a salaried job or owned a business were over three times more likely to have ever used or currently use tobacco products compared with those receiving government social grants. Conclusions: The prevalence of tobacco use in this study was significantly higher than the general population in the Eastern Cape. Therefore, smoking prevention and cessation interventions targeted at the general population should target this often neglected sub-population in the region. Keywords: Eastern Cape province; mental health users; mental illness; South Africa; tobacco use.
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  • Date Issued: 2021

Prevalence and factors associated with suicidal ideation amongst college students in the Nelson Mandela Bay Municipality, South Africa

  • Authors: Adeyinka A. Alabi , ROlawumi K. Oladimeji , Oladele V. Adeniyi
  • Date: 2021
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/11260/3337 , vital:43315 , https://doi.org/10.4102/safp.v63i1.5195
  • Description: Background: Suicidal behaviour amongst college students constitutes a significant social and public health problem globally. This study determined the prevalence and associated factors of suicidal ideation amongst students of higher education in the Nelson Mandela Bay Municipality (NMBM), South Africa. Methods: In this institution-based cross-sectional study, a multistage cluster sampling of 826 participants, drawn from a college in NMBM, was conducted from January to March 2020. Data were collected with a standardised self-administered questionnaire. Multivariable logistic regression analysis was used to identify the factors associated with suicidal ideation. Results: Participants’ ages ranged from 18 to 24 years, with a mean age of 20.49 years (standard deviation, 1.88 years). The lifetime prevalence of suicidal ideation and plans in the preceding 12 months were 24.5% and 9.6%, respectively. The odds of suicidal ideation were higher in students who experienced bullying (adjusted odds ratio [AOR], 1.89; 95% confidence interval [CI], 1.35–2.65), mental illness (AOR, 1.89; 95% CI, 1.35–2.65), a history of sexual assault (AOR, 2.50; 95% CI, 1.20–5.21) and experience of sexual assault by or to a close family member (AOR, 1.69; 95% CI, 1.01–2.82). Underlying chronic illness was associated with a twofold risk for suicidal ideation in both sexes. Conclusion: About a quarter of the students sampled at the college had experienced suicidal ideation and some had had suicidal plans in the preceding 12 months. Screening for the identified risk factors amongst the student population coupled with prompt interventions would mitigate the risk of suicide in the study population. Keywords: suicidal behaviour; suicidal plans; higher education; students; South Africa.
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  • Date Issued: 2021

Prevalence and factors associated with suicidal ideation amongst college students in the Nelson Mandela Bay Municipality, South Africa

  • Authors: Alabi, Adeyinka A , Oladimeji, Olawumi K , Adeniyi, Oladele Vincent
  • Date: 2021
  • Subjects: Suicidal behaviour Education (Higher) Students Article
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/11260/7235 , vital:53093 , xlink:href="https://doi.org/10.4102/safp.v63i1.5195"
  • Description: Background: Suicidal behaviour amongst college students constitutes a significant social and public health problem globally. This study determined the prevalence and associated factors of suicidal ideation amongst students of higher education in the Nelson Mandela Bay Municipality (NMBM), South Africa. Methods: In this institution-based cross-sectional study, a multistage cluster sampling of 826 participants, drawn from a college in NMBM, was conducted from January to March 2020. Data were collected with a standardised self-administered questionnaire. Multivariable logistic regression analysis was used to identify the factors associated with suicidal ideation. Results: Participants’ ages ranged from 18 to 24 years, with a mean age of 20.49 years (standard deviation, 1.88 years). The lifetime prevalence of suicidal ideation and plans in the preceding 12 months were 24.5% and 9.6%, respectively. The odds of suicidal ideation were higher in students who experienced bullying (adjusted odds ratio [AOR], 1.89; 95% confidence interval [CI], 1.35–2.65), mental illness (AOR, 1.89; 95% CI, 1.35–2.65), a history of sexual assault (AOR, 2.50; 95% CI, 1.20–5.21) and experience of sexual assault by or to a close family member (AOR, 1.69; 95% CI, 1.01–2.82). Underlying chronic illness was associated with a twofold risk for suicidal ideation in both sexes. Conclusion: About a quarter of the students sampled at the college had experienced suicidal ideation and some had had suicidal plans in the preceding 12 months. Screening for the identified risk factors amongst the student population coupled with prompt interventions would mitigate the risk of suicide in the study population. Keywords: suicidal behaviour; suicidal plans; higher education; students; South Africa.
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  • Date Issued: 2021

Prevalence and Implications of Telecommunication Counselling

  • Authors: Lusiba, Sinazo.
  • Date: 2021
  • Subjects: Counseling
  • Language: English
  • Type: Masters theses , text
  • Identifier: http://hdl.handle.net/11260/7554 , vital:54349
  • Description: ABSTRACT The purpose of the present study was to explore prevalence and implications of telecommunication counselling. Available literature suggests that telecommunication counselling may have far-reaching implications in the mental health practice in general, and particularly in psychology. This study was guided by the social information processing theoretical framework. A total number of 26 mental health practitioners aged from 22 to 45 were selected using purposive sampling. In this study questionnaires were distributed to respondents through email, email was also used to collect the research data. Research ethics, such as confidentiality, anonymity, and voluntary participation, were strictly observed. The Statistical Package for Social Sciences version 23 was used to analyse the data. The analysed data are presented in frequency tables and graphs. This study found that there are effectiveness and efficiency factors associated with the use telecommunication counselling. Furthermore, the findings imply that the popularity of this type of counselling has been growing steadily in the past few years, especially in urban areas. Furthermore, despite the increase and growing popularity in the use of telecommunication counselling, the results suggest the presence of ethical dilemmas that confront the practitioners. , Thesis (Masters) -- Faculy of Humanities, Social Sciences and Law, 2021
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  • Date Issued: 2021

Prey and predator density‐dependent interactions under different water volumes

  • Authors: Cuthbert, Ross N , Dalu, Tatenda , Wasserman, Ryan J , Sentis, Arnaud , Weyl, Olaf L F , Froneman, P William , Callaghan, Amanda , Dick, Jaimie T A
  • Date: 2021
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/466957 , vital:76802 , https://doi.org/10.1002/ece3.7503
  • Description: Predation is a critical ecological process that directly and indirectly mediates population stabilities, as well as ecosystem structure and function. The strength of interactions between predators and prey may be mediated by multiple density dependences concerning numbers of predators and prey. In temporary wetland ecosystems in particular, fluctuating water volumes may alter predation rates through differing search space and prey encounter rates. Using a functional response approach, we examined the influence of predator and prey densities on interaction strengths of the temporary pond specialist copepod Lovenula raynerae preying on cladoceran prey, Daphnia pulex, under contrasting water volumes. Further, using a population dynamic modeling approach, we quantified multiple predator effects across differences in prey density and water volume. Predators exhibited type II functional responses under both water volumes, with significant antagonistic multiple predator effects (i.e., antagonisms) exhibited overall. The strengths of antagonistic interactions were, however, enhanced under reduced water volumes and at intermediate prey densities. These findings indicate important biotic and abiotic contexts that mediate predator–prey dynamics, whereby multiple predator effects are contingent on both prey density and search area characteristics. In particular, reduced search areas (i.e., water volumes) under intermediate prey densities could enhance antagonisms by heightening predator–predator interference effects.
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  • Date Issued: 2021

Primary healthcare approach to substance abuse management

  • Authors: Kaswa, Ramprakash
  • Date: 2021
  • Subjects: Substance abuse Diseases Primary health care Article
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/11260/7259 , vital:53104 , xlink:href="https://doi.org/10.4102/safp.v63i1.5307"
  • Description: Substance abuse is common amongst patients attending primary healthcare settings. Despite the substantial impact on one’s health, substance abuse is often underdiagnosed by primary care providers owing to a lack of training and time for screening. Self-reported screening tools are easy to administer and efficient to make a substance abuse diagnosis in primary care settings. Comorbid mental illness and intimate partner violence are common amongst patients presenting with substance abuse in primary care. An early diagnosis and a brief behavioural change counselling are effective in managing substance abuse before it develops into dependency. A brief motivational communication rather than a confrontation during substance abuse screening, counselling and treatment is important to achieve optimum patient outcomes. Keywords: substance abuse; primary healthcare setting; screening tools; brief behavioural change counselling; co-morbidity
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  • Date Issued: 2021

Prioritisation of targets for weed biological control I: a review of existing prioritisation schemes and development of a system for South Africa

  • Authors: Downey, Paul O , Paterson, Iain D , Canavan, Kim N , Hill, Martin P
  • Date: 2021
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/417763 , vital:71484 , xlink:href="https://doi.org/10.1080/09583157.2021.1918636"
  • Description: Biological control is widely utilised for the management of invasive alien plants (IAP). With the ever-increasing number of IAPs, it is important to prioritise targets for biocontrol in order to maximise the use of resources and the chances of success. This paper reviewed 12 previous systems developed to prioritise plant targets for biocontrol. The review underpins the selection of attributes and methodologies for the prioritisation of targets for biocontrol in South Africa. All of the previous systems are purpose-built and context-specific, so a new system is required for the South African setting. Previous prioritisation systems were assessed based on the attributes and methodology adopted. The attributes of previous systems were grouped into three sections, being (1) impact/importance of the target plant, (2) likelihood of achieving success, and (3) investment required. Nineteen attributes from previous systems are included in the new system, while nine were excluded due to a requirement for legislation and/or research, or because they conflicted with objectives of the new system in some way. Two methodological approaches were identified for how systems sourced information, either sourcing information through expert knowledge or the use of available literature and data. This information was then applied through either a quantitative or qualitative scoring method. A quantitative scoring method, with information sourced from available resources, was selected as the most appropriate methodology in the context of the new system for South Africa. This review streamlined the development and testing of the South African Biological Control Target Selection system.
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  • Date Issued: 2021

Prioritising biological control agents for release against Sporobolus pyramidalis and Sporobolus natalensis (Poaceae) in Australia

  • Authors: Sutton, Guy Frederick
  • Date: 2021
  • Subjects: Grasses -- Diseases and pests , Bruchophagus , Wasps , Alien plants -- Biological control -- Australia , Sporobolus -- Biological control -- Africa , Sporobolus -- Biological control -- Australia , Insects as biological pest control agents -- Australia , Insects as biological pest control agents -- Africa
  • Language: English
  • Type: text , Thesis , Doctoral , PhD
  • Identifier: http://hdl.handle.net/10962/172445 , vital:42201 , 10.21504/10962/172445
  • Description: Sporobolus pyramidalis Beauv. and S. natalensis (Steud.) Th. Dur. and Schinz. (giant rat’s tail grass) (Poaceae), invade rangelands and pastures in eastern Australia, costing the livestock industry approximately AUS$ 60 million per annum in grazing losses. Mechanical and chemical control options are costly and largely ineffective. Biological control is viewed as the most promising control option, however this management strategy has largely been avoided for grasses, due to their perceived lack of suitably host-specific and damaging natural enemies. In this thesis, the prospects for using biological control against S. pyramidalis and S. natalensis in Australia was assessed, in light of these potential challenges. Climate matching models were used to identify high-priority geographic regions within the plants’ native distributions to survey for potential biological control agents. High-priority regions to perform surveys were identified by modelling the climatic suitability for S. pyramidalis and S. natalensis in sub-Saharan Africa (i.e. their potential native ranges’), and climatic compatibility with regions where biological control is intended in Australia. High-priority regions for S. pyramidalis included: (1) coastal East Africa, ranging from north-eastern South Africa to Uganda, including south-eastern DRC, (2) some parts of West Africa, including inland regions of the Ivory Coast and western Nigeria, (3) northern Angola and (4) eastern Madagascar, and for S. natalensis included: (1) eastern South Africa, (2) eastern Zimbabwe, (3) Burundi, (4) central Ethiopia and (5) central Madagascar. Prospective control agents collected from these regions have the highest probability of establishing and proliferating in Australia, if released. In surveys of the insect assemblages on S. pyramidalis and S. natalensis in the climatically-matched region of eastern South Africa fifteen insect herbivores associated with the grasses were identified. Insect feeding guild, geographic distributions, and seasonal abundances suggest that three stem-boring phytophagous wasps, Tetramesa sp. 1, Tetramesa sp. 2 and Bruchophagus sp. 1 (Hymenoptera: Eurytomidae), have potential as control agents. Species accumulation curves indicated that additional surveys in South Africa are unlikely to yield additional potential control agents. Field host-range surveys of 47 non-target grass species in South Africa showed that Tetramesa sp. 1, Tetramesa sp. 2, and Bruchophagus sp. 1, were only recorded from S. pyramidalis and S. natalensis. Integrating field host-range with phylogenetic relationships between plant species indicated that no native Australian Sporobolus species or economic crops and pastures are expected to be attacked by these wasps. All three wasp species are predicted to be suitably host-specific for release in Australia. Three other endophagous herbivores attacked non-target native African Sporobolus species that share a close phylogenetic relationship to native Australian Sporobolus species, and therefore, demonstrate considerable risk of non-target damage. These species should not be considered as potential control agents. Under native-range, open-field conditions, Tetramesa sp. 1 caused an approximately 5-fold greater reduction in plant survival and reproductive output than Tetramesa sp. 2 and Bruchophagus sp. 1. Tetramesa sp. 1 in combination with Tetramesa sp. 2 did not significantly increase the level of damage, while Bruchophagus sp. 1 may decrease the efficiency of Tetramesa sp. 1, if released in combination. Tetramesa 1 is therefore the most promising candidate agent. Prioritising potential agents using predicted efficacy allowed otherwise equally suitable prospective agents to be prioritised in a strategic manner. Prioritising which natural enemies to target as biological control agents is a complex task. Field host range and damage assessments in the native range may provide more realistic data than typical studies performed under artificial conditions in a laboratory or quarantine. Moreover, it could assist practitioners in prioritising the most suitable agent(s) at the earliest stage in the programme as possible. This study demonstrated that grasses are suitable targets for biological control as they can harbour host-specific and damaging natural enemies.
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  • Date Issued: 2021

Probing the binding sites of novel 2-substituted imidazole-4,5-dicarboxylic acids : Towards new imidazole-based drugs

  • Authors: Clark, Candyce Raine
  • Date: 2021
  • Subjects: Heterocyclic compounds Coordination compounds
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: http://hdl.handle.net/10948/50848 , vital:42957
  • Description: A series of benzimidazole and imidazole-4,5-dicarboxylic acids were prepared using known and adapted protocols. Novel ligands synthesised in this study include 2-tert-butyl-benzimidazole, 2-tert-butyl-imidazole-4,5-dicarboxylic acid, an intermediate in the synthesis of 1,2- bis(2-benzimidazyl)-1,2,-dihydroxyethane and 2-(2-hydroxyphenyl)-benzimidazole with a salicylic acid co-crystallisate. All ligands prepared were reacted with metal salt solutions in order to prepare metal coordination compounds. Complexes with Cu(II), Ag(I), Mn(II), Ni(II) and Cd(II) ions and 2-phenyl-imidazole-4,5-dicarboxylic acid were prepared, as well as Cu(II) and Mn(II) with 2-trifluoro-methyl-imidazole-4,5-dicarboxylic acid and Cu(II) ions with 2-(2- hydroxyphenyl)-benzimidazole. The ligands and complexes were characterised by means of single-crystal X-ray diffraction studies, NMR analysis, UV spectrophotometric analysis and IR spectroscopy. DFT studies were carried out for selected ligands in order to provide theoretical values for comparison. Antimicrobial studies were performed on some of the ligands and complexes and these results show promise for the future development of new imidazole-based drugs.
  • Full Text:
  • Date Issued: 2021

Progress and prospects for the biological control of invasive alien grasses Poaceae) in South Africa

  • Authors: Sutton, Guy F , Bownes, Angela , Visser, Vernon , Mapaura, Anthony , Canavan, Kim N
  • Date: 2021
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/414448 , vital:71147 , xlink:href="https://hdl.handle.net/10520/ejc-ento_v29_n3_a12"
  • Description: Historically, invasive alien grasses have not been considered a major threat in South Africa, and as a result, very few resources are allocated to their management. However, there is an increasing awareness of the severe environmental and socio-economic impacts of invasive grasses and the need for appropriate management options for their control. South Africa has a long history of successfully implementing weed biological control (biocontrol) to manage invasive alien plants, however much like the rest of the world, invasive grasses do not feature prominently as targets for biocontrol. The implementation and early indicators of success of the few grass biocontrol programmes globally and the finding that grasses can be suitable targets, suggests that biocontrol could start to play an important role in managing invasive alien grasses in South Africa. In this paper, we evaluated the prospects for implementing novel grass biocontrol projects over the next ten years against 48 grasses that have been determined to represent the highest risk based on their current environmental and economic impacts. The grasses were ranked in order of priority using the Biological Control Target Selection system. Five grasses were prioritised – Arundo donax L., Cortaderia jubata (Lem.) Stapf, Cortaderia selloana (Schult and Schult) Asch. and Graebn., Nassella trichotoma (Hack. ex Arech.), and Glyceria maxima (Hartm.) Holmb., based on attributes that make them suitable biocontrol targets. Arundo donax has already been the target of a biocontrol programme in South Africa. We reviewed the progress made towards the biocontrol of this species and discuss how this programme could be developed going forward. Moreover, we outline how biocontrol could be implemented to manage the remaining four high-priority targets. While biocontrol of grasses is not without its challenges (e.g. unresolved taxonomies, conflicts of interest and a lack of supporting legislation), South Africa has an opportunity to learn from existing global research and begin to invest in biocontrol of high-priority species that are in most need of control.
  • Full Text:
  • Date Issued: 2021

Promising photodynamic antimicrobial activity of polyimine substituted zinc phthalocyanine and its polycationic derivative when conjugated to nitrogen, sulfur, co-doped graphene quantum dots against Staphylococcus aureus

  • Authors: Sen, Pinar , Nyokong, Tebello
  • Date: 2021
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/185304 , vital:44363 , xlink:href="https://doi.org/10.1016/j.pdpdt.2021.102300"
  • Description: Antimicrobial resistance is a most important problem facing the treatment of infectious diseases. Antimicrobial photodynamic therapy is an alternative treatment strategy, considered to be cost-effective and feasible. For this purpose, octa-imine substituted ZnPc (3) have been prepared and conjugated to nitrogen, sulfur co-doped graphene quantum dots (N,S-GQDs) through π-π stacking. The photophysical and photochemical properties of Pc alone and and Pc-conjugated to the GQD nanomaterial such as absorption, fluorescence, fluorescence life time, singlet oxygen quantum yields, triplet state quantum yields and exited state lifetimes were investigated in solutions before in vitro cell studies. The PACT activity of prepared structures was investigated against Gram-positive (Staphylococcus aureus). Our results suggest that the in the case of conjugation of zinc Pc to N,S-GQDs, photodynamic inactivation increased with the 100 % reduction percentage.
  • Full Text:
  • Date Issued: 2021

Prospects for the biological control of Northern Temperate Weeds in South Africa

  • Authors: Martin, Grant D
  • Date: 2021
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/414478 , vital:71151 , xlink:href="https://hdl.handle.net/10520/ejc-ento_v29_n3_a10"
  • Description: The Northern Temperate Weeds programme is a novel biological control (biocontrol) programme started in 2017, with the aim of reducing the impacts of northern temperate weeds that are common, widespread and problematic in the high elevation grasslands of South Africa. As these regions are the most important systems for water security, providing nearly 50% of all water run-off, it is surprising that these species were not targeted for biocontrol previously. Thus far, research has focused on biocontrol feasibility as well as ecological and socio-economic impact studies on several northern temperate weeds, including Pyracantha angustifolia (Franch.) C.K.Schneid, Rosa rubiginosa L., Cotoneaster spp., Rubus spp., (all Rosaceae) and Salix spp. (Salicaceae). In addition, research conducted in the USA and Europe on the natural enemies associated with two of these species, Robinia pseudoacacia L. and Gleditsia triacanthos L. (both Fabaceae and native to the USA), have provided South African researchers with the necessary foundation to initiate programmes against these weeds. Research in South Africa is currently focused on pre-release studies on R. pseudoacacia, using the leaf miner Odontota dorsalis Thunberg (Coleoptera: Chrysomelidae) and the black locust midge Obolodiplosis robiniae Haldeman (Diptera: Cecidomyiidae), and on G. triacanthos, using a seed bruchid, Amblycerus robiniae F. (Coleoptera: Chrysomelidae). Progress with these programmes and potential constraints that may limit success, are discussed.
  • Full Text:
  • Date Issued: 2021
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