The effect of piospheres on the ecology of insectivorous birds and their arthropod prey
- Authors: Balmer, Natasha Louise
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424380 , vital:72148
- Description: Desertification is the degradation of arid ecosystems that result in the loss of biodiversity. Piospheres are areas of local degradation around a central point due to overgrazing and increased herbivore presence. There is a paucity of information regarding the effect of localised degradation on arthropods and insectivorous birds. Both of these organisms play crucial roles in ecosystem functioning and stability and can be used as models to study ecosystem functioning. I investigated the effect of piospheres on arthropods and birds in the Eastern Cape province of South Africa. I found that the abundance and diversity of arthropods were significantly reduced inside the piospheres due to the lack of vegetation. Termites were a group specifically negatively impacted by piospheres, with a significant reduction in their presence inside the piosphere. The family composition of arthropods also changed inside and outside the piospheres, with Caelifera, Diptera and Formicidae being the most dominant groups. The diversity of birds was also significantly reduced due to the degradation inside the piospheres. Looking at insectivorous birds, I found that the reduction in both vegetation and arthropod prey availability resulted in non-random avoidance of piospheres. This shows that piospheres negatively impact both arthropods and birds. The results from my study are supported by other literature studying the effects of habitat degradation associated with desertification. Due to the similarities of degradation between piospheres and desertification I make the argument that piospheres can be studied as localised models of desertification. The decrease in vegetation and arthropod abundance and diversity was found to further impact the feeding success of insectivorous birds. Using piospheres as a model for desertification, I found that the foraging effort of birds is significantly reduced within a degraded area due to the lack of vegetation providing safety to arthropod prey species. In addition to this, the foraging efficiency of insectivorous birds is significantly reduced inside the piospheres due to the decreased arthropod abundance and diversity. This shows that inside the piospheres birds spend less time searching for insects and have fewer successful feeds. This has implications for desertification of arid environments where birds face hyperthermia. , Thesis (MSc) -- Faculty of Science, Zoology and Entomology, 2023
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- Date Issued: 2023-10-13
The effectiveness of prolonged exposure therapy for the treatment of PTSD and suicide ideation: a case study
- Authors: Mhlane, Zuziwe Gloria
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424997 , vital:72200
- Description: Post-Traumatic Stress Disorder (PTSD) is regarded as a public health burden in South Africa (SA) (Atwoli et al., 2013; Kagee, Bantjies & Saal 2017; Koenen et al.; 2017; Williams et al., 2007). According to McGowan & Kagee (2013), young adults in SA are a high-risk group of trauma. Exposure to trauma is also associated to comorbid conditions such as depression, anxiety suicidal ideation (SI) experienced by a large population (Bantjes, McGowan, Kagee & Steel, 2016). Prolonged Exposure (PE) is empirically supported and evaluated trauma therapy for PTSD (Foa, Hembree, & Rothbaum, 2007). However, there has been limited to no studies conducted to evaluate the effectiveness of PE in SA. Therefore, this study investigated whether PE is effective treatment for PTSD symptom reduction and suicide ideation in South Africa. Three participants were recruited from Focus on the Family SA (FOTF SA SA) through purposive sampling, and single-case experimental design (SCED) was utilised. PE was implemented online through zoom for 6 sessions on each client. At baseline, all the participants met the criteria for PTSD as per the Post-traumatic stress disorder symptom scale interview for DSM-5 (PSSI-5): Participant 1 (PSSI-5 - 63), Participant 2 (PSSI-5 - 53), Participant 3 (PSSI-5 - 63) and the clinical cut off score is 23. Furthermore, all participants were screened for suicide ideation (SI) using the Beck Suicide Inventory (BSI). All participants’ BSI score ranges were mild to moderate. Participants were also screened for depression using the Beck Depression Inventory second edition (BDI-II) and anxiety using the Beck Anxiety Inventory (BAI). The score ranges for both BDI-II and BAI were moderate to severe. The Clinical Outcomes in Routine Evaluation-Outcome Measure (CORE-OM) was also used to assess general psychological distress. The CORE-OM scores for all the participants for trauma, depression and anxiety were severe. However, the risk to self/SI for all the participants was minimal. During the intervention phase, all the participants scores showed a downtrend of PTSD symptomology, as per the Post-traumatic Stress Disorder Checklist for DSM-5 (PCL-5). The PCL-5 scores went down from PCL-5 score of 58 to final session PCL-5 score of 3. The clinical cut off score is 31-33. They were also screened using the BSI, BDI and BAI and the score ranges were mild. The CORE-OM scores for trauma, anxiety, depression, and risk to self/SI were also minimal. Overall, the preliminary result of this study supports the notion that adults with symptoms of PTSD and SI had improved at the end of a brief 6-session PE intervention. The comorbid depression also showed a downtrend. , Thesis (MA) -- Faculty of Humanities, Psychology, 2023
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- Date Issued: 2023-10-13
The effectiveness of the Therapeutic Sandstory Method as a focused intervention with a child: a descriptive single case study
- Authors: Francis, Staci
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424973 , vital:72198
- Description: This study explores and describes a phenomenological case study, illustrating a postmodern constructionist orientation to sandtray work with a South African child. The Therapeutic Sandstory Method (TSM) involves the innovative integration of a variety of tenets when working with children– constructing sandworlds, storytelling, the reflection of stories and coherent therapeutic documents in therapy collectively facilitating the healing process. This novel method enables children to translate and communicate their own personal experiences and traumas into a concrete form through storytelling and metaphoric connections constructed in their sandworld. It is anticipated that the TSM is a brief yet feasible, child-centered therapeutic engagement designed to continue the therapeutic process outside of the therapy setting, making it ideally suited for children and adolescents from under-resourced communities. The results of the study revealed improved interpersonal functioning and emotional wellbeing after eight sessions. Contextualized narrative and social constructionist findings are discussed and recommendations made pertaining to future research and practice using TSM with children in therapy. , Thesis (MA) -- Faculty of Humanities, Psychology, 2023
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- Date Issued: 2023-10-13
The effects of different shift patterns on nurses’ sleep-wake behaviours in selected, private healthcare facilities
- Authors: Bell, Emma Catherine
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424219 , vital:72134
- Description: Nurses are required to work shifts to provide 24-hour care, in which they complete physically and mentally demanding tasks. The length and type of shifts, particularly night shifts interfere with the natural sleep-wake behaviours, leading to extended wakefulness and overall reduced sleep, and increase the likelihood of sleepiness during subsequent shifts. This can in turn affected various cognitive processes such attention, vigilance and alertness, which are necessary during the care process. Sleepiness as a result of working shifts has also been associated with an increased risk accidents and error during the delivery of care. Given the unique demands and ways in which workplaces are structured, each context arranges its shifts in unique ways and thus, in order to determine how to manage the effects of shift work, it is important to understand how it affects self-reported fatigue and sleep, of, in this case, nurses. While there has been extensive research on this in the global north, to date, there has been limited research aimed at examining the effects of shift work on nurses’ sleep-wake behaviours and fatigue in the South African context. Therefore, the aim of this study is to characterise shift arrangements in selected private facilities and explore its effects on private healthcare nurses. This study adopted a cross-sectional, survey design using an amended version of Standard Shiftwork Index. The questionnaire included demographic and shift details and explored the impact of the shift systems on nurse sleep-wake behaviours and disturbances and fatigue and workload. It was distributed among shift working nurses registered with the South African Nursing Council across three selected, private, healthcare facilities in the Eastern Cape, over a two-month period. The responses were analysed with descriptive and inferential statistics, with open-ended questions analysed using a thematic analysis. A total of 51 nurses completed the survey. Nurses worked 12-hour shifts which included night shifts and day shifts with fixed start and end times. Over time was commonly reported and generally, nurses reported having very little control over their shift arrangements. Overall, nurses slept less than what they reported they needed on duty days, with nurses working both day and night shifts reporting to sleep less than the globally recommended required sleep. This was compensated for by longer sleep durations during days off. The data collection revealed that three different shift arrangements were in use, including permanent day shifts, permanent night shifts and rotating shift work including nights, with permanent night nurses working significantly more consecutive shifts (seven) than the other two shift types and having significantly more days off (seven) as well. While there were no significant differences in self-reported sleep across the three shift types, permanent night nurses were found to have the shortest sleep. During days off, rotating nurse reported significantly longer sleep times compared to day shift workers which may point to the need to catch up from sleep debt. Rotating nurses experienced the greater total disturbances to their sleep than permanent day and permanent night shift nurses. While not statistically significant, it may point to the fact that rotating shift workers could not obtain regularly timed sleep (due to having to change their schedules) compared to permanent day and night nurses. Workload (physical, emotional, mental and time pressure) did not differ between the shifts (day or night) or the shift types, but did reflect a heavier workload, possibly due to the data collection occurring during the 5th wave of the COVID 19 pandemic. This study highlights that nurses in private healthcare facilities are working extended hours which were associated with reduced total sleep, irrespective of the nature of the shift, with rotating shift nurses experiencing some degree of greater disturbances to their sleep. The number, duration speed and direction of the shifts of rotating nurses needs to be explored further, whilst also exploring the influence of individual factors on sleep-wake behaviours of nurses. It may be beneficial for the healthcare facilities to implement fatigue management strategies to mitigate the negative impacts of shift work, given the impact that this may impact the delivery of care. , Thesis (MSc) -- Faculty of Science, Human Kinetics and Ergonomics, 2023
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- Date Issued: 2023-10-13
The effects of exploitation on the activity of Chrysoblephus laticeps in a thermally variable environment
- Authors: Mlotshwa, Nonhle Thubelihle
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424346 , vital:72145
- Description: Embargoed. Expected release date 2025. , Thesis (MSc) -- Faculty of Science, Ichthyology and Fisheries Science, 2023
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- Date Issued: 2023-10-13
The effects of short-duration overnight kraaling on herbaceous vegetation and soils in mesic grassland
- Authors: Mgwali, Nompendulo
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424721 , vital:72178
- Description: Land degradation is widespread in communal rangelands in the grassland biome of South Africa, and often attributed to overstocking and lack of coordinated management. Excessive pressure on the herbaceous component has contributed to the uncontrolled spread of opportunistic invasive alien woody species e.g. Acacia mearnsii in many degraded areas, resulting in significant loss of ecosystem service capacity, along with soil and land productivity. Short-duration overnight kraaling has been suggested as a tool for restoring degraded rangelands. Recent studies in semi-arid savannas and shrublands have reported increased grass cover, soil nutrients and palatability and concluded that short-duration kraaling is a low-cost and effective way of restoring degraded rangelands using livestock. However, the response of different plant functional types and communities to such intense livestock impact may vary depending on local context. This study used twelve paired kraal and control sites to investigate the effects of short-duration (7-24 days) overnight kraaling of livestock on herbaceous vegetation and soils in a mesic grassland. The study area is generally considered to be overgrazed but has considerable variation in grass composition and basal cover. Sites included relatively intact natural grassland and sites where wattle infestations had been cleared and where mostly bare ground remained. I tested the hypotheses that overnight kraaling would result in (1) increased basal cover due to introduction of grass seed and stimulation of germination through hoof action, (2) increased infiltration due to hoof action, and (3) increased soil nutrients and organic matter due to dung and urine deposition. I also hypothesized that factors such as a site’s initial grass cover, its slope, the occurrence and amount of rainfall before and during kraaling, and the kraaling intensity (number of livestock and duration of the kraaling event) would influence the magnitude and direction of the kraaling effect. The effect of kraaling on vegetation was strongly dependent on initial condition. Kraaling increased basal cover of grasses when sites had low initial basal cover, but decreased basal cover if initial values were over 50%. Infiltration increased if kraaling took place during or after rain but decreased if kraaling took place when soils were dry. Kraaling increased soil P and K. In mesic grasslands, short-duration overnight kraaling is promising as a tool for rehabilitating degraded sites but should be avoided where the grass sward is relatively intact. I recommend that the suitability of kraaling be further evaluated per vegetation type and local context. , Thesis (MSc) -- Faculty of Science, Botany, 2023
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- Date Issued: 2023-10-13
The electrocatalytic activity of metallophthalocyanines and their conjugates with carbon nanomaterials and metal tungstate nanoparticles
- Authors: Ndebele, Nobuhle
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/431934 , vital:72816 , DOI 10.21504/10962/431933
- Description: In this dissertation, seventeen phthalocyanine complexes were synthesised. Of these, only four are known and have been published. These complexes were synthesised using the conventional statistical condensation method that involves refluxing the phthalonitrile(s) (4-((1,3-bis(dimethylamino)propan-2-yl)oxy)phthalonitrile, 4-(4-carboxyphenoxy)phthalonitrile, 4-(4-acetylphenoxy)phthalonitrile, dimethyl 5-(3,4-dicyanophenoxy)-isophthalate, 4-(4-(tert-butyl)phenoxy)phthalonitrile, 5-phenoxylpicolinic acid phthalonitrile 4-(4-formylphenoxy) phthalonitrile, and 4-(4-(3-oxo-3-phenylprop-1-enyl) phenoxy) phthalonitrile) with the metal salt and 1,8-diazabicyclo[5.4.0]undecane as a catalyst in a high-temperature solvent. And thereafter (when necessary), isolation and purification of the target compounds were achieved through the use of silica column chromatography. These compounds were characterised using various analytical techniques such as; ultraviolet-visible absorption, mass spectroscopy, and Fourier transform infrared spectra and elemental analysis. These techniques proved that the complexes were successfully synthesised and isolated as pure compounds. Carbon-based (graphene quantum dots and nitrogen-doped graphene quantum dots) and metal oxide (bismuth tungsten oxide and nickel tungsten oxide) nanomaterials were synthesised. Together with the purchased single-walled carbon nanotubes, these nanomaterials were conjugated to some of the MPc complexes via non-covalent (carbon-based nanomaterials) and covalent (metal oxides) linkage forming hybrid materials. These nanomaterials and hybrids were characterised using various analytical methods (ultraviolet-visible absorption, X-ray diffraction, Raman spectroscopy, thermographic analysis, and dynamic light scattering). Nanomaterials were utilised herein to determine their effect on the properties of MPc complexes and provide a synergistic effect in the hope of enhancing these properties. All complexes synthesised in this work (MPcs, nanomaterials and hybrids) were employed as electrocatalysts in electrochemical sensing. These electrocatalysts were embedded onto the glassy carbon electrode via an adsorption method known as drop-casting. The modified electrode surfaces were characterised using cyclic voltammetry, electrochemical impedance spectroscopy and scanning electrochemical microscopy to determine various electrochemical parameters. These electrocatalysts were used in the detection of either nitrite, catechol and/or dopamine. The detection limits, sensitivities, kinetics and catalytic constants were among other parameters determined for each electrocatalyst. These electrocatalysts proved to be stable electrocatalysts that could potentially be used for practical applications. The determined parameters were comparable and sometimes better than those obtained in literature. , Thesis (PhD) -- Faculty of Science, Chemistry, 2023
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- Date Issued: 2023-10-13
The enigmatic subterranean amphipod genus (sternophysinx: sternophysingidae): conservation and systematics
- Authors: Mlungu, Zizile
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424424 , vital:72152
- Description: Sternophysingidae Holsinger, 1992 is a monotypic subterranean amphipod family endemic to Namibia and South Africa. It currently has eight described species under the genus Sternophysinx. The species in this family are considered narrow endemics, having only been identified using morphological characters. However, the apparent wide distribution of certain species, reported in several subterranean waters in different provinces, suggests that our current taxonomic understanding of these species needs to be completed, thus needing revision. Further, detailed knowledge of the distribution and phylogenetic relationship between species of this taxon still needs to be improved. This study aimed to use integrative taxonomy to analyse both morphology and molecular biology to study hidden diversity and to further our understanding of the distribution in this taxon. The available morphological keys were used to identify species, and 12S rRNA was also used to investigate the relationships of Sternophysinx species and delimit species boundaries. The study primarily aimed to use mitochondrial cytochrome c oxidase subunit I (COI). However, due to technical issues such as getting the correct primers, this study's aims were altered, and 12S was used instead of CO1. However, the process of getting CO1 sequences is still ongoing, and the results will be made available elsewhere. The current study aimed to visit all the type localities of the seven species of Sternophysinx reported in South Africa, including all known localities in which these amphipods have been recorded in the past. Nevertheless, this study did not get samples from Nelspruit, De Hoop Nature Reserve, and Nash Nature Reserve, which cover type localities of S. travaleensis, Matlapitse and Chaos cave that harbours S. calceola. Instead, the current study added five new localities Graaff-Reinet, Beaufort West, Hogsback, Makhambathi Nature Reserve and Ntsikeni Nature Reserve, for the distribution, including two new provinces (i.e., Eastern Cape and KwaZulu-Natal) that had records of this genus in the country. Three delimitation methods, Assemble Species by Automatic Partitioning (ASAP), Bayesian implementation of the Poison Tree Processor (bPTP) and Automatic Barcode Gap Discovery (ABGD), were used to identify cryptic species within Sternophysinx. Phylogenetic analyses and three delimitation methods (ASAP, bPTP and ABGD) revealed considerable hidden cryptic diversity within this Sternophysinx. Preliminary morphological examination revealed at least two species as undescribed from Bakwena and Sterkfontein caves, and several that were morphologically identified using the current taxonomic keys did not match with the molecular analysis. For example, S. basilobata from three different systems, Boesmansgat cave (Northern Cape), Beaufort West (Western Cape) and Potchefstroom (North West), was in genetically different putative species. The same is true for S. robertsi and S. alca in Ficus and Peppercorn cave in Limpopo. Overall, the results of the current study demonstrate the need for a comprehensive integrative taxonomic revision of Sternophysinx. These findings suggest that S. basilobata is a complex of distinct lineages and requires further study. On the other hand, species delimitation methods suggested that there are 12- 14 candidate species (Figure 2.5). Lastly, this study investigated the threat posed by the invasive koi fish introduced to an important cave, Boesmansgat cave in the Northern Cape, which is a type locality of two endemic species (S. megacheles and S. basilobata). Stable isotope (δ13C and δ15N) and gut content analyses of the fish were investigated to establish whether this invasive fish feed on these critical creatures, thus endangering their long-term survival. Stable isotope signatures and the stomach gut content proved to be helpful in determining the diet of the koi fish, revealing it to be an omnivorous feeder with high invertebrate preference, including amphipods. These results indicate that the introduction of koi fish in the Boesmansgat cave threatens the long-term sustainability of these amphipods and other invertebrate assemblages in this cave. , Thesis (MSc) -- Faculty of Science, Zoology and Entomology, 2023
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- Date Issued: 2023-10-13
The ergonomic assessment of two different pipette models and their effects on biomechanical, performance, and subjective outcomes
- Authors: Masoka, Bonolo
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424278 , vital:72139
- Description: While laboratory workers are essential in many industries, they are also at a high risk of developing musculoskeletal disorders (MSDs). Manual pipetting has been identified as the leading cause of MSDs in laboratories because it exposes operators to high forces, repetition, static muscular loading, and awkward wrist postures for prolonged periods. The main contributors to the high risk associated with manual pipetting are the design of manual pipettes and how they are used. A laboratory-based study was conducted to assess and compare the biomechanical, subjective, and performance responses of an ergonomically designed pipette model to those of a traditional model. In a simulated laboratory workstation, 20 individuals performed 40 repetitions of pipetting tasks using each pipette model. Dependent variables consisted of muscle activity (of the Abductor Pollicis Brevis, Opponens Pollicis, Extensor pollicis longus, Abductor pollicis longus, Extensor pollicis brevis, and brachioradialis muscles), wrist postures, time to task completion, perceived muscular exertion (measured using the Borg RPE scale), perceived comfort and usability, and user preference. The results revealed that an ergonomic modification to pipette design has some effect on biomechanical and subjective outcomes. The ergonomic model significantly reduced muscular loading of the Opponens pollicis, and Abductor pollicis brevis muscles. The ergonomic model also reduced radial deviation and was associated with better subjective responses, while the time to task completion did not change. This study found that an ergonomic modification to pipette design can improve user comfort and well-being without compromising performance. Overall, the findings emphasize the importance of addressing pipette design to reduce the MSD risk associated with manual pipetting, and the necessity for a user-centred approach to tool design. , Thesis (MSc) -- Faculty of Science, Human Kinetics and Ergonomics, 2023
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- Date Issued: 2023-10-13
The heterologous expression and in vitro biochemical characterization of the Hsp70 escort protein 1 and mitochondrial Hsp70 partner proteins of the Trypanosoma brucei parasite and humans
- Authors: Mahlalela, Maduma Ernst
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/431832 , vital:72807 , DOI 10.21504/10962/431832
- Description: The 70 kDa family of heat shock proteins (Hsp70) plays a central role in the maintenance of cellular proteostasis, with paralogues occurring in all the major compartments of the eukaryotic cell. Hsp70s act in conjunction with proteins known as co-chaperones, as part of the larger molecular chaperone network. In the mitochondrion, Hsp70 (mtHsp70) is responsible for the import of proteins synthesized in the cytosol, protein folding in the matrix and the maintenance of the iron-sulphur cluster. In human cells mtHsp70 (HSPA9) is also referred to as mortalin, as the knockdown of the protein leads to cell mortality. Trypanosoma brucei is the causative agent of sleeping sickness in humans and nagana in animals. In the T. brucei parasite there are three identical mtHsp70 (TbmtHsp70) proteins that are produced, forming part of the Hsp70 machinery that is essential for parasite survival. In humans, the levels of HSPA9 are often elevated in non-communicable diseases such as cancer and neurodegeneration. Despite their vital cellular roles, mtHsp70s are characteristically prone to self-aggregation. The binding of the Hsp70 escort protein (Hep1) is required to prevent the aggregation of mtHsp70 proteins, enabling the proteins to function. In many non-communicable diseases, mtHsp70 and other molecular chaperones such as heat shock protein 90 (Hsp90) are being investigated as potential drug targets. Existing anti-trypanosomal drugs for treating sleeping sickness are toxic, having adverse side effects that are potentially lethal. Investigations into Hsp70s, and other molecular chaperones, form part of the research into the discovery of novel and efficacious therapeutics. This is the first study to characterise Hep1 and investigate its partnership with mtHsp70 in T. brucei. The overall aim of this study was to comparatively assess the T. brucei and human mtHsp70/Hep1 partnerships. The putative T. brucei Hep1 (TbHep1) orthologue was analysed in silico, and it was found to possess a zinc finger domain consisting of anti-parallel β-sheets that are characteristic of canonical Hep1 proteins, whilst the N-terminal domain was unstructured. Based on sequence analysis, the regions outside of the zinc finger domains lacked conservation. Despite the lack of sequence conservation, the N- and C-terminal regions of TbHep1 shared segments of similarity with Hep1 orthologues of other kinetoplastid and trypanosomal orthologues. The same held true for the N- and C-termini of human Hep1 (HsHep1) when compared to other Hep1 orthologues of mammalian origin. Biochemical analysis revealed TbmtHsp70 and HSPA9 to be prone to self-aggregation, which was reduced by co-expression with TbHep1 and HsHep1, respectively. Recently Hep1 proteins have been determined to be present in the cytosol. In this study, TbHep1 and HsHep1 also interacted with the cytosolic Hsp70s, HSPA1A and TbHsp70, by preventing their thermally induced aggregation and stimulating their ATPase activities. TbHep1 and HsHep1 also suppressed the thermally induced aggregation of the model substrates malate dehydrogenase and citrate synthase, independently of Hsp70. To date, only two Hep1 orthologues, HsHep1 and LbHep1, have been found to function in a similar manner to a J-protein co-chaperone by stimulating the ATPase activities of their partner mtHsp70 proteins. In this study, TbHep1 stimulated the ATPase activity of TbmtHsp70. HsHep1 also stimulated the ATPase activity of TbmtHsp70. However, the mechanism of action still needs to be determined. This study also explored the potential of the Hep1 orthologues to be functionally activated by oxidative stress, which is prevalent in mitochondria. The abilities of TbHep1 and HsHep1 to reduce the thermally induced aggregation of malate dehydrogenase were enhanced under oxidative conditions. Disrupting the function of Hep1 has been found to eventually lead to cell death, and given the critical role played by mtHsp70 in the cell, this partnership could be exploited as a potential drug target. In conclusion, this study demonstrated that TbHep1 and HsHep1 functionally interact with mtHsp70s, whilst also possessing independent chaperone activities that are also potentially influenced by the environmental redox state. , Thesis (PhD) -- Faculty of Science, Biotechnology Innovation Centre, 2023
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- Date Issued: 2023-10-13
The mathematical and pedagogical content knowledge that Namibian senior primary teachers draw on to develop their learners’ computational estimation
- Authors: Shigwedha, Emilia Ndilimeke
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424108 , vital:72124
- Description: Computational estimation is important in the development of learners’ number sense. It is through the process of finding an approximate (but satisfactory) that learners can check the reasonableness of their answers to calculations, develop an understanding of place value and by implication the four number operations. It is the role of teachers to develop the computational estimation skills of learners. To do this, teachers need to have a sound knowledge of computational estimation, its value and how to teach it. This study thus seeks to explore and understand Namibian senior primary teachers’ mathematical and pedagogical content knowledge to develop their learners’ computation estimation knowledge. The research is guided by the following question: What mathematical and pedagogical content knowledge do senior primary mathematics teachers draw on to develop their learners’ computational estimation skills? The research is a qualitative interpretivist case study. Eight senior primary teachers of Mathematics from the Ohangwena region in Namibia participated in the study. Data was generated through questionnaires, a focus group interview and lesson observations. The Mathematics Knowledge for Teaching (Ball et al., 2008) and the Knowledge Quartet (Rowland, 2005) frameworks were used as both analytic and explanatory tools for the study. Key findings from the research are that teachers have knowledge of and use a variety of strategies for estimation, however, they only use the ‘rounding off’ strategy when teaching learners computational estimation. The teachers appear to teach computational estimation by first focusing on place value before moving on to ‘rounding off’ to the nearest 10s, 100s, 1000s and so forth. My research recommends that the National Institute of Educational Development together with the Ministry of Education, Art and Culture in Namibia, provide teachers with professional development opportunities on how to develop learners’ computational estimation. Such professional development will further develop teachers’ mathematical and pedagogical content knowledge. Furthermore, the Namibian syllabus should include a variety of strategies for computational estimation. , Thesis (MEd) -- Faculty of Education, Primary and Early Childhood Education, 2023
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- Date Issued: 2023-10-13
The obligation of South Africa to provide social security to refugees and asylum seekers during the COVID-19 pandemic
- Authors: Dekeda, Awethu Zethu
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424119 , vital:72125
- Description: Covid-19 a novel pandemic, has wreaked havoc globally, threatening the livelihoods of all, including refugees and asylum seekers. Like all other countries globally, South Africa has gone to great lengths to mitigate the challenges that this pandemic has caused. However, it is far from clear whether these responses are according due regard to the rights of some of the most vulnerable in society, amongst which are refugees. This thesis deals with South Africa’s obligation to provide social security to refugees during the Covid-19 pandemic. It specifically assesses whether South Africa's responses to the Covid-19 pandemic were in adherence to fundamental refugee law principles relevant to the protection of refugees. The study commences with a general introduction, followed by an analysis of the international human rights and refugee law framework relevant to protection of refugees. This framework is used to assess South Africa’s responses. Subsequently, the discussion delves into South Africa’s own national framework on social security. Using the standards identified in both the national and international frameworks, the thesis then proceeds to measure South Africa’s Covid-19 related responses regarding social security to resolve the issue of whether South Africa adhered to these standards in as far the protection of refugees’ right to social security is concerned. , Thesis (LLM) -- Faculty of Law, Law, 2023
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- Date Issued: 2023-10-13
The photodynamic therapeutic activities and optical limiting properties of metalated asymmetric porphyrins and corroles
- Authors: Burgess, Kristen Paige
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424490 , vital:72158
- Description: Cancer is a devastating disease that is a leading cause of death worldwide. Despite the available cancer treatments, there is a significant need to improve the therapeutic approach towards this disease. Photodynamic therapy (PDT) is an alternative approach for treating cancer, which requires a photosensitiser, molecular oxygen and light. Although some porphyrin-based derivatives have been approved by the United States Food and Drug Administration (FDA) and other similar agencies elsewhere for photodynamic therapy, their relatively poor photophysicochemical properties mean that there is an ongoing need for new photosensitiser dyes. Singlet oxygen photosensitiser dyes can also be used to treat bacteria that develop antimicrobial resistance in the context of photodynamic antimicrobial chemotherapy (PACT). The main aim of this study was to synthesise and characterise a series of porphyrin dyes with 4-quinolinyl, thien-2-yl and 4-bromo-thien-2-yl meso-aryl groups and their Sn(IV) and In(III) complexes, as well as their corrole analogues. Corroles are contracted macrocycles that have interesting optical properties. The corroles selected for study were found to be difficult to synthesise and purify and had unfavourable photophysicochemical properties and were thus omitted from the PDT and PACT biological applications within this thesis. High- and low-symmetry A4 and ABAB type meso-tetraarylporphyrins porphyrins were synthesised to improve the photophysicochemical properties of the photosensitisers; the utility of these dyes as photosensitisers was studied against the MCF-7 breast cancer cell line for PDT and against Staphylococcus aureus and Escherichia coli for PACT. The thienyl-2-yl rings were introduced to red shift the lowest energy Q band towards the phototherapeutic window, while quaternisation of the nitrogen and sulfur atoms of the 4-quinolinyl and thien-2-yl rings to introduce a cationic nature was explored to improve the bioavailability of the drugs and uptake into the target cell walls for improved efficacy. Heavy Sn(IV) and In(III) central metal ions were introduced to enhance the singlet oxygen quantum yields and limit aggregation through axial ligation. The bromine atoms of the 4-bromo-thien-2-yl meso-aryl rings were also introduced to enhance the singlet oxygen quantum yields of the dyes. Furthermore, the utility of the porphyrin and corrole molecules for optical limiting properties to limit laser radiation to protect optical devices, including eyes, was explored by the z-scan technique. One of the dyes studied, Sn(IV) tetrathien-2-ylporphyrin, that exhibited the most favourable reverse saturable absorbance (RSA) response was embedded into a poly(bisphenol carbonate A) polymer thin film to further explore its suitability for practical applications. , Thesis (MSc) -- Faculty of Science, Chemistry, 2023
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- Date Issued: 2023-10-13
The possible effect of insecticide drift from citrus orchards, and acute toxicity of insecticides on the biocontrol agents of Pontederia crassipes (Mart.) Solms-Laub (Pontederiaceae) established along citrus orchards in the Lowveld region of Mpumalanga Province, South Africa
- Authors: Mabuza, Mefika Michael
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424468 , vital:72156
- Description: This study investigated the possible effect of insecticide drift on naturalized biological control agents of Pontederia crassipes (Mart.) Solms-Laub (Pontederiaceae), in the Lowveld region of Mpumalanga Province of South Africa. Occurrence and abundance of biocontrol agents were recorded at three sites on the Crocodile River and at three dams adjacent to citrus orchards. Leaves of P. crassipes and water samples were collected for insecticide residues and also nutrient status of the water and plants. Eccritotarsus catarinensis Carvalho (Hemiptera: Miridae), Neochetina spp. (combined) (Coleoptera: Curculionidae), and Orthogalumna terebrantis Wallwork (Sarcoptiformes: Galumnidae) were recorded with notable variation in abundance between the river and dams across regions. Insecticide residues were not detected on all leaves sampled across study regions, however, nutrients were detected with nitrate ranging between oligotrophic and mesotrophic. Phosphorus was also detected, but, neither of the nutrients correlated with the occurrence and abundance of naturalized biological control agents of P. crassipes. Bioassays were conducted to measure the effect of commonly used insecticides (viz. Methomyl and Chlorpyrifos) on the survival and feeding damage of biological control agents of P. crassipes. Survival of individual insects was recorded between 0.5 and 120 hours for Megamelus scutellaris and Neochetina eichhorniae Warner (Coleoptera: Curculionidae) adults for treatments where insecticides were topically applied onto the insects or leaves were dipped into the pesticides. Concentrations below field rates, recommended and above field rates of Methomyl and Chlorpyrifos on either exposure techniques significantly reduced survival and feeding of biocontrol agents. Methomyl was more toxic compared to Chlorpyrifos and it significantly reduced the survival of M. scutellaris and N. eichhorniae. In conclusion, in this study, population abundance of biocontrol agents of P. crassipes at the Lowveld region of Mpumalanga was not influenced by pesticide drift, but, insecticides commonly used in the citrus orchards has the potential to negatively impact naturalized biological control of P. crassipes as demonstrated by the bioassays. , Thesis (MSc) -- Faculty of Science, Zoology and Entomology, 2023
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- Date Issued: 2023-10-13
The prevalence of alcohol use disorders among university students in developing countries: a systematic review and meta-analysis
- Authors: Ndlovu, Philani
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/425019 , vital:72202
- Description: High alcohol misuse is associated with many challenges, including (a) unsafe sex, problems with the criminal justice system, absenteeism, academic failure, death, injury, and alcohol related harm, both in the developing and developed world. Despite the above, no meta-analysis had been conducted in the literature to comprehensively study the prevalence of Alcohol Use Disorders (AUDs) amongst university students in the developing world. This study reviewed literature related to AUDs among university students in developing countries. It described the concept of AUD and the harmful effects of excessive alcohol use, including biological, cognitive, psycho-social, and economic impacts on the individual and the family. , Thesis (MA) -- Faculty of Humanities, Psychology, 2023
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- Date Issued: 2023-10-13
The professional experiences of early career counselling psychologists in South Africa: a mixed method study
- Authors: Haine, Phillipa Claire
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/432321 , vital:72861 , DOI 10.21504/10962/432322
- Description: Counselling psychologists represent a considerable proportion of psychologists in South Africa (SA), yet knowledge on the discipline’s workforce is limited. In addition, professional lifespan issues have received inadequate attention, inclusive of the early career stage, identified as an exceptionally vulnerable segment of the professional lifespan. Undergirded by an interpretative phenomenology research paradigm, this mixed method sequential explanatory study, consisting of two distinct phases, aimed to explore the professional experiences of early career counselling psychologists (counselling ECPs) in SA, inclusive of employment trends, challenges and support needs. The quantitative phase (‘First Phase’) comprised of an online survey questionnaire (n = 512) to investigate the employment trends of counselling ECPs in SA. A qualitative phase (‘Second Phase’) followed, comprising of online semi-structured interviews with ten counselling ECPs. The rationale for this was that the preliminary quantitative data provided a broad understanding of the research problem, whereas the qualitative data sought to expand on the quantitative data by exploring the participants’ experiences in depth. Moreover, the collection of quantitative data provided a strong justification and phenomenological orientation for the second, qualitative, phase. The data from the two research phases were combined within a joint discussion to ensure a level of methodological complementarity and a more holistic understanding of the data captured. Trends from the first, quantitative, phase demonstrated that counselling ECPs differed across various domains from more senior generations. In the second, qualitative, phase, Interpretative Phenomenological Analysis of the data revealed three Group Experiential Themes: i) Complexity of finding and securing work, ii) Navigating an array of personal, professional and systemic challenges, and iii) Support as self-acquired. Overall, the findings suggest that counselling ECPs in SA face a variety of challenges upon entering the workforce, enhanced support is thus needed for this new, more diverse cohort of practitioners. Actionable recommendations are offered at various levels. , Thesis (PhD) -- Faculty of Humanities, Psychology, 2023
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- Date Issued: 2023-10-13
The relevance of career counselling in higher education: a study following students at a South African university
- Authors: Lewis, Christine
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/432347 , vital:72863 , DOI 10.21504/10962/432348
- Description: Very few students in South Africa (SA) receive adequate career counselling at school and often arrive at institutions of higher learning without a clear sense of what their prospective careers will entail. The limited access to career counselling and assessment is further compounded by criticisms of popular career assessment instruments used in SA, where the primary goal of career counselling and assessment is to match clients to careers for job placement. This approach no longer serves the needs of a diverse SA population and disregards contextual influences on careers. Therefore, a need exists to understand and inform career counselling interventions and to guard against the provision of de-contextualised and contextually insensitive approaches. Moreover, changes in the workplace, where career change has become the norm as the world of work has moved away from stability and permanency to fluidity, calls for a contemporary response from career counselling theories, practitioners as well as researchers, to equip clients with the necessary skills to respond to these changes. Thus, SA institutions of higher learning need to innovate their practices to more inclusively, effectively, and justly serve the needs of a diverse student population for work success in a developing nation and a complex world. This study aimed to evaluate the relevance and effectiveness of a university’s career counselling services from the students’ perspectives. It focuses on gaining an indication of the perceived effectiveness of assessment measures used, and to ascertain the influences that impact on individual students’ career decision-making over the course of undergraduate studies. Due to the increasing recognition for the need to develop a contextualised approach to career development interventions, this study included the SACII, a locally developed interest inventory as part of a career assessment battery, with a group of university students. A pragmatic approach using mixed-methods was used. Multiple case studies of the career trajectories of a cohort of undergraduate students who had undertaken career assessments at the university career centre, were tracked longitudinally over the course of undergraduate studies. Data were generated through vignettes that included the 13 participants' career assessment reports, a service evaluation questionnaire and two successive follow-up interviews. Each participant's first follow-up interview occurred six months after their career assessment feedback session; and the second follow-up was in the final year of undergraduate studies, after eighteen months. Descriptive statistical analysis summarised the basic features of the quantitative data from the evaluation questionnaire. Thematic analysis was used for organisation and analysis of the follow-up interview data. Findings were that the career counselling and assessment facilitated greater self-knowledge in relation to career decision-making, assisted with selecting degree major subjects and enhanced career planning abilities. Using locally developed assessment measures in career counselling proved to be useful. Exploring career development from an overarching developmental contextual framework that is applicable and well-suited to the SA context provided a deeper understanding of contextual influences that impact on students' career decision-making processes. , Thesis (PhD) -- Faculty of Humanities, Psychology, 2023
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- Date Issued: 2023-10-13
The Role of the courts in the interpretation and implementation of the Right to Basic Education in Section 29(1)(a) of the South African Constitution
- Authors: Ngubane, Kwanele Nhlanhla
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424141 , vital:72127
- Description: The right to education in section 29(1)(a) of the Constitution was meant to signal a break between an education system divided along racial lines, and a new democratic education system based on equity, equality, and opportunity for all learners. In reality, the South African education system still remains deeply divided along racial lines, with poor, mostly black learners, being under-resourced by the state, while their richer, mostly white, counterparts are being taught in schools that have access to all the resources necessary to realise the right to basic education. As a result, the right to education in section 29(1)(a) of the Constitution has been heavily debated, and between 2010 and 2022, the South African courts have often been called on to interpret the right. In the process, a rich jurisprudence has developed on the core content of the right to basic education, with findings by the courts that the right includes an entitlement to a number of educational resources. These include access to school infrastructure, learner-teacher support materials, desks and chairs, scholar transport, teaching and non-teaching staff, and nutrition. This study examines the way South African courts, between 2010 and 2022, have interpreted and implemented the right to basic education to give effect to section 29(1)(a) of the Constitution. While South African courts have historically shied away from interpreting socio-economic rights to contain a minimum core content and have rather opted for a reasonableness approach, the same is not entirely true for section 29(1)(a). As stated above, courts have been willing to find that the right entails a minimum basket of goods and services without which the right cannot be realised. By examining some of the most important education rights cases during this period, the study proposes that there are five factors that have guided the courts’ interpretation of the right and has assisted in the courts finding that the right contains a minimum core content. These factors are the historical context of the right to basic education; the textual formulation of the right to basic education in section 29(1)(a) of the Constitution; the interrelatedness of the right to basic education and other rights within the Bill of Rights; subsidiary education policies, legislation, and regulations, and lastly, the role of international law. This study seeks to consider the extent to which each of these factors have played a role in courts’ interpretation of section 29(1)(a). The study also considers the implementation of these judgments and the role that the courts have played in realising the right to education for learners on ground-level. , Thesis (LLM) -- Faculty of Law, Law, 2023
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- Date Issued: 2023-10-13
The use of dynamic software to potentially enhance conceptual understanding and a productive disposition in the visual learning of algebra: an interventionist case study
- Authors: Junius, Daniel Franscius
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/431542 , vital:72784 , DOI 10.21504/10962/431542
- Description: Over the decades, the didactics and practice of teaching mathematics has offered many unique challenges and opportunities for exploration and understanding. The introduction and development of technology into mathematics is one of the occurrences which has also contributed to a new discourse in teaching mathematics – in this case the teaching of algebra. Algebra is still seen as a gatekeeper and remains as one of the key reasons for a negative disposition amongst learners towards learning the subject. Across the globe psychologists, philosophers and educators continue to engage in debates and research projects in search of answers and solutions for the improvement of algebra teaching and an improvement in dispositions towards learning algebra. This thesis reports on a research project that focused on the use of dynamic software to enhance the conceptual understanding and productive dispositions of selected learners through the visual learning of abstract algebraic concepts. The research was executed as an interventionist case study. A case study methodological strategy was adopted with two groups of 30 Grade 9 learners. One group was a Grade 9 mathematics class of a school in Windhoek who scored above average in algebra but showed a very low disposition score, while the other group was made up of learners from a community project who scored high on the disposition scale but achieved below average results in algebra. The analytical framework of the case study is structured around a combination of complementary algebraic topics presented through visual learning, with GeoGebra as a medium of instruction. With the focus on visualisation and the use of technology the study investigated and attempted to understand how participants processed and internalised algebraic concepts to make sense of abstract algebraic concepts and eventually gain sustained conceptual understanding. The study was framed by the theoretical theories of constructivism and the Dual Coding Theory. For the collection of data, a mixed methods approach was adopted following three cycles. Three algebraic topics were taught with GeoGebra applets yielding both qualitative and quantitative data, through the observation of participants, screen captures and reflective interviews, using instruments designed specifically for the study and collecting quantitative achievement test results. The study, a journey that both the participants and the researcher embarked upon, revealed that the use of technology enhanced conceptual understanding for both groups and both groups showed a positive change in disposition towards learning algebra. The intervention with GeoGebra consistently and progressively improved in terms of conceptual understanding and dispositions towards learning algebra significant improvements in results were achieved. The findings showed that this approach to teaching algebra yielded positive results and gave new insights into visual teaching with technology. New opportunities for further research were created. , Thesis (PhD) -- Faculty of Education, Secondary and Post-School Education, 2023
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- Date Issued: 2023-10-13
The views and opinions of Rhodes University lecturers towards isiXhosa as a language of learning and teaching (LOLT) in higher education
- Authors: Nkunzi, Zintle
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424963 , vital:72197
- Description: This research sought to investigate how African languages function as a communicative tool in a university where English is the medium of instruction. The study's purpose is to provide a systematic review of research that has been carried out on language attitudes towards isiXhosa as a language of learning and teaching (LoLT) in higher education. The study reveals that South African higher education institutions such as Rhodes University mostly use English as the LoLT- a language which for most lecturers is not their first/home language but helps ease communication in a multilingual community. Rhodes University is characterised by multilingualism because the university community is made up of diversity in culture, language, and educational background of the people. Previously explored language attitude studies are based on students’ views and this study investigated RU lecturer views and opinions towards isiXhosa as a LoLT. The study focused on the importance and the need (if any) of isiXhosa in a multilingual higher education institution. The study reveal that language barriers are one of the difficulties, but academic cultural differences seem to play a crucial role that can impact on the learning and teaching outcomes. This can lead to negative experiences and the forming of stereotypical views. These views include how lecturers are and should be trained to teach mathematics, science, and academic studies in African languages. The SA higher education practices and language use (i.e., monolingual language policy) are one of the reasons that the implementation of indigenous languages in education policies in SA is fraught with difficulties due to several factors. Amongst the factors is the fact that indigenous languages are not yet fully developed as academic languages. The study further reveals that lecturers find it difficult to teach mathematical studies in isiXhosa because of lack of terminology in the language for academic purposes particularly at a tertiary level. Furthermore, existing literature highlights the importance of the use of code-switching which is a beneficial practice for lecturers in assisting their students who struggle with English as a LoLT at RU. The lecturer views towards isiXhosa as a LoLT at RU is not only on language barrier but also about the lack of development in the language use in spaces where only English is believed to be the best such as language for academics. The study also reveals an integration of Information Communication Technology in education and how language appears as a barrier. , Thesis (MA) -- Faculty of Humanities, School of Languages and Literatures, 2023
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- Date Issued: 2023-10-13