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Strategy to enhance the academic performance of Grade 12 progressed learners in life sciences
No full textThe aim of the study was to design a strategy to enhance the academic performance of Grade 12 progressed learners in life sciences. The strategy emerged from the large number of Grade 12 progressed learners who perform poorly in life sciences. The theoretical framework that underpinned the study is critical emancipatory research (CER), as developed by the Frankfurt School of 1923. Four principles were applied: active communication, transformation, emancipation and social justice. These principles supported the study by facilitating emancipation of teachers and Grade 12 progressed learners in life sciences. Participatory action research (PAR) was applied in this study as an approach to generate data and find a strategy to enhance the academic performance of Grade 12 progressed learners in life sciences, and to complement CER by supporting disadvantaged learners at schools, and build a better future for them. Homologous purposeful sampling was used as a method of sampling. Teachers, including a subject advisor, and Grade 12 progressed learners participated in data generation through WhatsApp focus group discussions. This method was used as a part of a qualitative research study, to collect data according to the principles of PAR, and within the limitations imposed by Covid-19 pandemic restrictions and regulations. Data that was collected from the participants through WhatsApp group discussions was analysed with the thematic model suggested by Laws, Harper and Marcus, which involves seven steps. The findings of this study identify the factors that contribute to poor academic performance of progressed learners, and suggest ways to improve the academic performance of Grade 12 progressed learners.University of the Free State (UFS
Students’ perceptions of the research component in an applied psychology master’s programme
No full textThis study is aimed at exploring students’ perceptions of research as a component in an applied psychology master’s program. The perceptions of the students were explored through the lens of the self-determination theory (SDT) of Deci and Ryan (1985), particularly the basic psychological needs sub-theory. A qualitative approach was followed and a multiple case study design was applied. Data were collected through semi-structured interviews with 13 participants. The data were analyzed using the thematic analysis approach, which resulted in the finding of three themes and nine subthemes. The findings are discussed using the three basic psychological needs sub-theory to assess how the motivation of the participants was affected by either the thwarting or satisfaction of those needs. The basic psychological needs of the students were frustrated in specific instances during the research process, and for others these needs were fulfilled for the majority of the research process. Participants perceived the mini-dissertation as time consuming and financially and emotionally challenging but simultaneously as beneficial for personal and professional development. Participants were also challenged with difficult supervisory relations. The study could provide current applied psychology master’s training programs and their students with valuable information regarding challenges and shortcomings of the training programs. Researchers interested in the training of psychologists could also benefit from the information provided by this study
A study of the synthesis, characterization and cytotoxicity of tropones and troponimines and its Rhenium(I) coordination compounds
No full textRhenium(I) tricarbonyl complexes have gained much interest over the past years for its possible applications in radiopharmacy, chemotherapy and photodynamic therapy (PDT). In order to defeat cancer worldwide, it is imperative that scientists develop better, and improve current treatment methods. In this study the aim is to expand the knowledge on Re(I) tricarbonyl complexes and its potential in anticancer research, with the focus on good cytotoxicity and photoluminescent properties. Five N,O bidentate 2-(alkylamino)tropone ligand systems were successfully synthesized in yields between 22 % and 66 %. Nine N,N’ bidentate aminotroponimine ligand systems were successfully synthesized in yields ranging from 22 % to 74 %. Five Re(I) tricarbonyl complexes of the type fac-[Re(CO)3(H2O)(N,O)] (N,O = different N,O bidentate ligands) and nine of the type fac-[Re(CO)3(H2O)(N,N’)] (N,N’ = different N,N’ bidentate ligands) were synthesized successfully in yields of 66 % - 75 % and 53 % - 94 %, respectively. The crystal structures of 2-tosyloxytropone (TropOTs), 2-(methylamino)tropone (TropNHMe) and 2-(2-fluoroethylamino)tropone (TropNHEtF) were obtained, solved and reported in this study. The structures of these molecules have interesting packing patterns in their unit cells. TropNHMe has three molecules in the asymmetric unit and TropOTs and TropNHEtF have only one. Hydrogen bonding interactions are observed in all three the structures and in TropNHMe these interactions form one-dimensional infinite chains. In the structures of TropOTs and TropNHMe π-π interactions are observed, but not in TropNHEtF, where hydrogen bonding interactions are possibly responsible for the packing pattern observed in the unit cell. The in vitro cytotoxicity of all the ligands and four of the fac-[Re(CO)3(H2O)(N,O)] (N,O = different N,O bidentate ligands) complexes was determined. The results include IC50 values ranging from 0.45 μM - 36.1 μM for the ligands and 47.0 μM - 77.4 μM for the complexes. Four of the N,N’ bidentate ligands, namely [(EtPh,Bn)ATI]H, [(Me,Bn)ATI]H, [(Et,Bn)ATI]H and [(EtPh)2ATI]H have IC50 values of 0.45, 0.66, 1.10 and 2.4 μM, respectively, which are lower than that of cisplatin, the control in this study, with an IC50 value of 3.26 μM. Selected ligands and complexes were evaluated for its photoluminescent properties and the results are reported in this study. The excitation wavelengths of the ligands and complexes range from 257 nm - 377 nm and the emission wavelengths from 405 nm - 517 nm. The intensity of the emissions ranges from 2.37 x 103 to 21.5 x 103 arbitrary units with [(Me)2ATI]H having an exceptionally high intensity value of 218.0 x 103 arbitrary units. The 2-(alkylamino)tropone ligands and its complexes have longer excitation wavelengths than that of the aminotroponimine ligands and its complexes with fac-[Re(CO)3(H2O)(TropNEtPh)] being the exception. TropNHEtF, TropNHBn and TropNHEtPh and their Re(I) tricarbonyl complexes fac-[Re(CO)3(H2O)(TropNEtF)], fac-[Re(CO)3(H2O)(TropNBn)] and fac-[Re(CO)3(H2O)(TropNEtPh)] are the three ligand-complex pairs that exhibit red shifts in their emissions from the ligand to the complex. The quantum yields of the compounds could unfortunately not be determined successfully due to the low intensities of the emissions.National Research Foundation (NRF
Uptake and partitioning of salt by wheat and maize under irrigation in a semi-arid climate
No full textIrrigated soil is affected by salinity on a global scale, resulting in impaired crop development and reduced yields. Mitigation measures exist to decrease root zone salinity through leaching practices but this has detrimental offsite impacts. With increasing temperatures inducing water limitations, additional tactics are required to decrease root zone salinity. Crop salt removal is a tactic often overlooked due to the generally assumed small quantity of salts removed when crops are harvested but can aid as a viable measurement when quantified, especially for precision agriculture. This study therefore presented three research aims with focus on the salinity inducing cations; potassium, calcium, magnesium and sodium. The first research aim was to quantify cation uptake and partitioning of wheat (Triticum aestivum L.), maize (Zea mays L.) and popcorn (Zea mays everta), while the second research aim quantified the relationship between soil cations and cation uptake by these crops. The third research aim tried to spatially characterise soil cations and thus cation uptake using apparent soil electrical conductivity (ECa) measurements. Electromagnetic induction (EMI) surveys were conducted on three fields under centre pivots, which were located on commercial irrigation farms in the districts of Douglas and Luckhoff. These surveys were conducted at the beginning of the wheat (June 2016) and beginning of the maize and popcorn (December 2016) season. Soil and plant sampling points were identified based on the degree of soil apparent electrical conductivity (ECa) variability determined with the “Electrical Conductivity Sampling Assessment and Prediction” (ESAP) software and its featured “Response Surface Sampling Design” (RSSD) sampling methodology. The topsoil (0-300 mm) was sampled at the beginning of each crops’ season before planting, while the crops were sampled past physiological maturity (at harvest). Standard laboratory procedures were used to analyse the soil properties; bulk density, clay, gravimetric water, pH(water) and electrical conductivity of the saturation extract (ECe). Soil plant available ions were extracted with the Ambic-2 extraction method, while the closed-tube wet decomposition with acid technique was used to obtain the plant analytes. The Inductively Coupled Plasma Optical Emission Spectrometer (ICP-OES), which is an electro-spectroscopy technique, was used to analyse the cations present in the wheat, maize and popcorn plant material, as well as in the soil. For the first aim, the cation concentrations and weighted mean of the components were determined and compared with the sufficient and critical ranges of established literature, while the biomass and yield were compared with that of commercial cereal crops. Cation uptake was then calculated by multiplying the components weight with the concentration, from which biomass uptake can then be determined. The significant partitioning of cations by crop components was determined with mean separation at the 95% confidence interval. The stem-leaf of wheat, maize and popcorn was the dominant components to remove cations, (P ≤ 0.001). For the second aim, linear regression analysis was performed with Microsoft Excel to obtain a relationship between soil properties (ECe, SAR and clay) and cation uptake but only the SAR had a relationship and correlated with cation uptake. A linear relationship (R2 = 0.7) was then only found between SAR and Na+ in the soil for wheat. For the third research aim, the ESAP software was used to find ECa correlations between the afore mentioned soil properties, yield, biomass and soil cations but the results were unfavourable. Correlations for both aims were done at the 95% confidence interval. The results revealed that the mean cation uptake for the wheat, maize and popcorn biomass was 384.2 kg ha-1, 508.9 kg ha-1 and 359.8 kg ha-1, respectively. From this biomass uptake, it can be estimated that the wheat, maize and popcorn seeds partitioned a mean 11.5%, 12.7% and 8.5% of cations, respectively which is used to suit the need of the commercial market. However, crop residue is commonly left behind as a soil cover and can induce soil salinity when re-introduced into the soil medium. The wheat, maize and popcorn stem-leaf were therefore estimated to partition a mean 80.8%, 81% and 86.8% of cations, respectively. Crop salt removal can serve as an important mitigation measurement in minimising fertiliser applications and excessive irrigation practices when using crop components to enhance soil conditions such as organic matter, water retention and structure
Exploring agency in marginalised occupations: school administrative clerks' deployment of "participatory capital" in establishing practice-based agency
No full textPopular conceptions of school administrative clerks and school secretaries imply that they have little agency because they are deemed as subordinate support staff. However, the literature across a range of fields suggests that these subordinates exercise agency. We set out in this article to explore the workings of subordinate agency. The article suggests that it is through their involvement and interaction in the socio-cultural context of the school that school administrative clerks are able to expand the range of their agency and thereby reposition themselves at school. We employ the analytical construct “participatory capital” to analyse how these
clerks establish their agency and renegotiate their roles and places in the school. Based on a qualitative research study, we interviewed and observed three purposively selected administrative clerks in three primary schools in Cape Town. This article argues that, while the occupational identity of administrative clerks remains one of subordination within the bureaucratic discourse and their places of work, the selected school administrative clerks were able to extend the scope of their agency through their participatory capital.Publisher's versio
Reasons cited for the interruption of anti-retroviral treatment in the Bloemfontein/Mangaung area
No full textBackground: HIV infection is a chronic condition that affects millions of people worldwide and causes significant morbidity and mortality. It is however treatable with anti-retroviral treatment. This does require regular, uninterrupted dosages to prevent the development of treatment resistance. There are many reasons why patients may be unable to remain compliant on their treatment including medication, healthcare and psycho-social reasons. Objectives: To investigate the reasons cited for treatment interruption of anti-retroviral treatment in patients admitted to National District Hospital from the Mangaung district. Methods: This was a prospective descriptive study. Data was obtained by voluntary structured interviews from patients admitted to National district hospital between February and April of 2020. A total of 17 patients were included. Results: Unemployment among participants was at 68%, with 54% reporting no consistent income. There was a fairly even spread of reasons cited for treatment interruption between the healthcare, medication and psychosocial factors. Stock issues, however, remained a prominent problem reported. Almost half of participants reported omissions in their counselling prior to treatment initiation. Medication side effects remains a problem with 52% of participants reporting side effects and 44% of those attributed non-compliance to it. The majority of patients reported good family support and fear of disclosure or stigma was not reported. All participants screened positive for symptoms of depression, with 52% falling into the moderate and severe depression categories. Conclusions: The challenges for people living with HIV to remain compliant with their treatment remains numerous and varied. The role that unemployment and poverty plays cannot be ignored. Continuing efforts need to be made to create a robust supply of medication to patients if good outcomes are to be achieved. Patients need to be well educated prior to treatment initiation and given good advice regarding the management of side effects. The prevalence of symptoms for Depressive Mood disorder in this patient population is high and needs to be actively screened for at initiation and follow-up of patients. Further research within more well-defined communities can be beneficial for the healthcare workers working in those areas
Evaluation of the eosin-5-maleimide flow cytometric test and other screening tests in the diagnosis of hereditary spherocytosis
No full textBackground: Hereditary spherocytosis (HS) is a genetically determined haemolytic anaemia characterised by the spherical shape of affected red blood cells. With limited confirmatory tests currently available in South Africa, the diagnosis of HS is reliant on the clinical presentation and screening tests. Objectives: The aim of this study was to compare the sensitivity and specificity of three screening tests: flow osmotic fragility test (FOFT), cryohaemolysis test (CHT) and the eosin-5-maleimide binding test (EMA-binding test) in diagnosing hereditary spherocytosis (HS). Method: All three tests were performed on 18 subjects with confirmed HS. The negative control group was comprised of 10 subjects with haemolysis and spherocytosis, and either a positive direct antiglobulin test (DAT) or normal red cell membrane studies. The tests were also performed on samples submitted for cases of suspected HS during the study period. Results: The EMA-binding test demonstrated superior sensitivity (88.9%) compared to the CHT (61.1%) and the FOFT (38.8%). The EMA-binding test specificity (90.0%) was equal to that of the FOFT and superior to the CHT (50%). Combined sensitivities and specificities for EMA-binding test and CHT, EMAbinding test and FOFT, and CHT and FOFT, were 100% and 33.3%, 94.4% and 80.0% and 88.9% and 50.0%, respectively. Conclusion: EMA-binding test is the best screening test for cases of suspected HS. If there is a high clinical index of suspicion with a negative EMA-binding test, the CHT is recommended as a second screening test
Fusarium spp. and associated mycotoxins in South African maize
No full textMaize is an important staple food and feed crop in South Africa. This crop is however threatened by pathogens/pathogen complexes such as the Fusarium graminearum species complex (FGSC), the F. oxysporum species complex (FOSC) and F. verticillioides. These pathogens not only cause a decrease in grain yield and quality but may also produce mycotoxins, the most prevalent being deoxynivalenol (DON), nivalenol (NIV), zearalenone (ZEA) and fumonisins (FUM). This study was conceptualised because our understanding of Fusarium spp.-maize interactions is often limited to ear rots. Thus, this study consisted of five diverse chapters, which together gives a better understanding of the interaction between maize and Fusarium spp.. In Chapter 2 the North West province, in conjunction with, crop rotations, had the highest concentration of FGSC, FOSC and F. verticillioides. Unexpectedly, maize/wheat and maize monoculture did not contain the highest concentration of fungi. FGSC and F. verticillioides favours stalk tissue whereas FOSC favours roots. As expected, no-till fields favours pathogen/pathogenic complex disease but this is limited to certain tissues. Dryland fields favoured pathogen/pathogenic complex infection. ZEA and FUM were found in the majority of samples but FUM did not exceed the MTL set by the government whereas ZEA did. DON was less abundant but greatly exceeded the MTL during the third season. This suggests that although mycotoxins are season dependent there is a possibility that levels that could cause harm to humans and animals may be exceeded. This study enhances our knowledge of the influence of agricultural practices on these three Fusarium spp.. It also clearly indicates the importance of appropriate agricultural practices in reducing the risk of significant infection levels. In Chapter 3 the effect of abiotic and biotic factors on prematurely senescing plants in the Northern Cape was determined. It was observed that five nutrients impacted FGSC target DNA concentrations and increased (PSA) or decreased (VGA) the plants susceptibility. Ca increased disease severity with a trend towards higher stem rot incidence, whereas Mg, Na, K and B decreased disease incidence by increasing overall plant health and decreasing disease incidence and severity by the various role they play in plant defence responses. It was also shown that during the soft dough stage maize is the most sensitive towards plant disease. Thus, it could be seen that poor soil nutrition (environment), coupled with a susceptible plant (soft dough stage) and significantly high FGSC target DNA concentrations in In1 and In2 of season 2012/13 (virulent pathogens) resulted in the PSAs in maize fields. In Chapter 4 mycotoxin translocation throughout maize plants has in the past been shown to be possible, however in this study translocation of DON, NIV and ZEA was not shown. This was attributed to either the inability of these mycotoxins to be translocated in maize, the conditions were not ideal for translocation, or the maize genotypes were not conducive to translocation. The possibility of FUM translocation has only been evaluated in maize seedlings from roots to the leaves. In this study it was shown that there is a possibility of FUM translocation but because of the trace amounts of FUM found this possibility could not be confirmed. Thus, mycotoxin translocation of DON, NIV and ZEA was not confirmed but the possibility of FUM translocation was shown. Chapter 5 the first to examine maize stalk defence responses. It was expected that PR-1 would be highly upregulated at each time-point in the resistant cultivar with limited induction in the susceptible cultivar. Instead PR-1 was initially supressed, between 0 – 48 hai, then induced 96 hai. This was attributed to the biotroph/necrotroph switch. It is hypothesised that PR-1 plays a role in F. boothii-maize stalk rot resistance. WRKY1 was only induced in the susceptible cultivar at 72 hai. It is hypothesised that WRKY1 does not play a role in F. boothii-maize stalk rot resistance but may be responsible for the susceptibility of PAN 6479. Although some assumptions could be made from this study, further analysis is required to gain a definitive understanding of maize defence responses toward FGSC. Controlling pathogens or pathogen complexes such as Fusarium spp. is extremely difficult as they are highly adaptive, complex and diverse. However, as our understanding of these fungi increases so do the strategies in containing infections. This study focused on the interaction between Fusarium spp. and maize. The findings of this study could contribute to the prediction of Fusarium spp. infection on maize, the reduction in Fusarium disease on maize, the adaption of farming practices, and crops with less mycotoxin contamination.Agricultural Research Council (ARC)The Maize Trus
In vitro immune responses to Sindbis virus
No full textSindbis virus (SINV) is an arthritogenic alphavirus belonging to the Togaviridae family. SINV was initially isolated in Sindbis, Egypt in 1952, since then the virus has been isolated in different parts of the world including Africa, Asia, Australia and Europe. Infection with SINV results in febrile self-limiting symptoms that are usually of short duration. However, some individuals develop prolonged incapacitating joint pain that may persist for months to years. The mechanism by which SINV and other arthritogenic alphaviruses cause chronic arthritis is poorly understood however previous studies suggest the involvement of monocytes and macrophages which result in the secretion of pro-inflammatory cytokines which are induced by virus replicating in or around joint tissue. The aim of the study was to investigate the innate immune response to in vitro infection of macrophages with SINV in order to determine if human macrophages from different individuals differ in their susceptibility to SINV infection and to determine the role of interferon (IFN) in SINV infected macrophages. Peripheral blood mononuclear cells (PBMCs) were isolated from ten SINV antibody naïve individuals using ficoll-paque density gradient method. The cells were stimulated with human-macrophage colony-stimulating factor (HM-CSF) to differentiate from monocytes to macrophages. Post-stimulation the macrophages were infected with SINV at a multiplicity of infection (MOI) of 0.1. Additionally, some macrophages cultures were pre-treated with ruxolitinib, an IFN inhibitor 2 hours or immediately prior to infection with SINV at an MOI of 0.1. Virus replication was determined at different time intervals for 24 hours using a two-step quantitative RT-PCR. To determine the secretion levels of pro-inflammatory cytokines post-SINV infection, cell-free supernatant was collected at different intervals post-infection and levels of proinflammatory cytokines including IFN-α, TNF-α, IL-1β, IL-6, IL-8 and IL-12 in the supernatant were tested by ELISA. A primer pair that targets the nsP2 region of SINV nsP2 protein together with the TaqMan hydrolysis probe were used to quantify viral loads of infected macrophages by qRT-PCR. An increase in viral loads was detected in macrophages of 5/10 participants, suggestive of viral replication. A decrease in viral load over time was observed in macrophages of the remaining five participants, suggestive of little to no viral replication. IFN inhibition resulted in SINV replication in macrophages from 7/10 and 8/10 participants when treated at time 0 of infection and 2 hours prior to infection, respectively. Infection elicited a strong innate immune response demonstrated by secretion of pro-inflammatory cytokines including IFN-α. IL-6 and IL-8. Infection with SINV results in a strong pro-inflammatory response which seems to control viral load. Results suggest that macrophages are among SINV targeted cells during human infection and macrophages from different individuals appear to differ in their susceptibility to SINV replication. The study also shows that type I IFN may play an important role in the protection of SINV as its inhibition rendered macrophages from more participants susceptible to viral replication.National Health Laboratory ServiceThe South African Chairs initiative National Research FoundationPoliomyelitis Research FoundationUniversity of the Free State School of MedicineUniversity of the Free State Postgraduate Schoo
Renal cell carcinoma diagnosed by the Department of Anatomical Pathology at the University of the Free State, South Africa: a 10 year histopathological review
No full textDissertation (M.Med.(Anatomical Pathology))--University of the Free State, 2020Background: Globally, the incidence of renal cell carcinoma varies widely between populations and geographic areas, with the lowest incidence reported in Africa. Very little information is available on the epidemiology or histopathological profile of renal cell carcinoma (RCC) in the South African population, and most studies on RCC in Africa are from Nigeria. The determination of the incidence, demographic and histopathological features of RCC would provide the latest and most up to date information on RCC epidemiology in the state sector in central South Africa and would serve as a foundation for future research. Aim: The purpose of this study was determine the number of cases of RCC seen over a ten year period by the Department of Anatomical Pathology, University of the Free State and National Health Laboratory Service and to describe the demographic profile of the patients identified as well as the histological spectrum. We further aimed to determine the agestandardised incidence rate (ASR) of RCC for state sector patients from the Free State Province. Methods: A retrospective descriptive review with an analytical component was performed. All histologically confirmed cases of RCC identified between 1 January 2005 and 31 December 2014 were included in the study. The pathology reports were reviewed to collect the demographic information for each case and the H&E slides were reviewed to confirm the diagnosis and the specific histological subtype. ASRs were calculated using the population data from the South African census as performed in 2011. ASRs were only calculated for the Free State Province and patients from the North West and Northern Cape Provinces were excluded for these calculations as the department does not receive all the specimens from these two provinces. Results: A total of 105 patients with RCC were diagnosed with a male:female ratio of 1.2:1 and a mean age of 55.1 years. The age standardized incidence rate for the Free State province was 0.4 per 100 000 population. Ten patients (9.5%) were younger than 40 years. The majority of cases were identified in the age group 50 to 59 years (33.3%). The majority of patients (58.1%) were black and they were found to present on average a decade earlier than white patients. The most common histological subtype was clear cell RCC (58.1%). Patients diagnosed with papillary RCC were found to be significantly more likely to be male than female (72.7% vs 27.3%; p=0.03) and were also more likely to be black than white (81.8% vs 13.6%; p<0.01). Patients with chromophobe RCC were more likely to be female (80%) and black (60%). Two cases of a new entity, clear cell RCC with giant cells and emperipolesis were identified. All five patients with MiT family translocation RCC were diagnosed in black females. Conclusion: To our knowledge this is the most comprehensive study on RCC performed in our region. Our study demonstrated that the incidence of RCC in our population is lower than reported in the rest of the world. The age distribution correlates closely with other African studies, with black patients presenting a decade earlier than white patients. In addition, our findings identified distinct age, sex and racial differences for the various RCC subtypes, which warrants further research