Understanding variability across the Crossroad transect from 3 years (2013 to 2015) of hydrographic data

The southwest continental shelf of Africa is characterized by a strong western boundary current with three interdependent components, namely the Agulhas Current, Agulhas Retroflection and Agulhas Return Current. This system plays a key role in setting oceanic conditions south of Africa. The Crossroad transect intersects both the Agulhas Current and Agulhas Return Current; a monitoring line established in 2013 to sample both the currents and determine inter-ocean fluxes, as well as the influence of the Agulhas Current on the Agulhas Bank shelf. The objective of the study was to examine both mesoscale and submesoscale features that influence the dynamic and variant nature of the Agulhas system. In this study we make use of Ship board Acoustic Doppler Current Profiler (SADCP), Conductivity Temperature and Depth (CTD), Thermosalinograph (TSG) and satellite Sea Surface Height data as main observations for analysis. The study also examines both the spatial and temporal characteristics of water properties across the Crossroad transect. The fundamental findings of the study include the abundance of both the mesoscale and submesoscale features observed in the Agulhas system, which are often overlooked. In addition, a noticeable variability in current measurements was observed, where velocity ranging from 2 to 2.5 m/s represented the Agulhas Current and 1.4 to 1.7 m/s, Agulhas Return Current. The position of the Agulhas Current and Agulhas Return Current displayed variation from 2013 to 2015, with the Agulhas Return Current exhibiting a meandering pattern in 2014 along the transect. Furthermore, an intrusion of cool (8 to 13 °C), lower salinity (34.8 to 35 psu) South Indian Central Water masses were also observed along the Agulhas Bank. The ability to combine altimetry and in situ data also contributed to the analysis of the results. Therefore, given the inherent advantage of satellite and in situ measurements, an overview of the variability across the Crossroad transect was determined

Non-Neuroleptic Antitubercular and Anticancer Therapeutics through Rational Drug Remodelling of Phenothiazines and Related Antipsychotics

In light of shrinking pharmaceutical drug pipelines and drug resistance, innovative drug discovery strategies are of imperative need. Drug repurposing and related strategies such as drug rescue and drug remodelling have garnered significant research interest. Various clinically approved non-antibiotics including phenothiazines hold promise as novel classes of therapeutics in other indications. However, in addition to inherent neuroleptic properties, phenothiazines and related antipsychotics elicit adverse side effects at clinically relevant doses thus precluding their extensive clinical application. Herein, it was postulated that the selectivity of phenothiazines and related drugs for nonneuroleptic indications could be enhanced through rationalized structural remodelling. Phenothiazine and related neuroleptics are known to obey a lipophilic chromophore/basic side chain paradigm. Deviation from this paradigm is expected to decrease potential for neuroleptic effects. Therefore, the remodelling strategies involved introduction of novel functionalities that are dissimilar to native phenothiazine structures. Prior to chemical synthesis, drug metabolism and pharmacokinetic related properties were predicted in silico to assess drug-likeness of the new chemical entities derived from phenothiazines and related antipsychotics. The in silico profiling also included prediction of blood/brain partition coefficients and CNS activity to determine their likelihood of exhibiting neuroleptic effects. The new chemical entities were then evaluated against drug-susceptible Mycobacterium tuberculosis-H37Rv. Furthermore, a selected series was screened for binding to dopamine and serotonin receptors to corroborate in silico CNS activity predictions. Moreover, pharmacokinetic studies were conducted with the selected series to determine in vitro microsomal stability, kinetic solubility and in vivo toxicity profiles. Another objective of this study was to evaluate the new chemical entities for their potential as anticancer agents. The key findings herein demonstrated that it is possible to abolish neuroleptic effects through rationalized structural manipulation and still retain bio-activities of interest. Several new chemical entities including N-alkylsulfonates (DS0031, DS0032, DS0034, DS0035, DS00366) and nitrobenzenesulfonamides (DS00325, DS00326, DS00329) of phenothiazines, displayed notable antitubercular (GAST/Fe MIC90 range: 9.9-125 µM; 7H9 MIC range 12.5- 25 µg/mL) and anticancer (IC50 range 4.51-12.43 µM) activities in comparison to native phenothiazine drugs. Furthermore, in vitro and in vivo preclinical evaluation revealed favourable pharmacokinetic profiles. Overall, this study presents novel subclasses of phenothiazines that hold promise for further development as non-neuroleptic agents in either tuberculosis or cancer treatment regimens

Pedagogical responsiveness: Focus on the Ukuqonda institute’s mode of engagement in mathematics

This paper was prompted by mathematics teachers’ challenges in implementing the proposed framework that centres on teaching for understanding, as opposed to teaching aimed at producing marks as evidence of achievement. Teaching for understanding in mathematics, among other factors, requires the creation of engaging and inclusive learning environments underpinned by teachers’ pedagogical responsiveness to the diverse needs of learners. We investigated pedagogical responsiveness, focusing on the Ukuqonda Institute’s mode of engagement in mathematics. We specifically pursued two research questions: 1) What are the key elements of the Ukuqonda Institute’s mode of engagement in mathematics? and 2) What characterised the pedagogical responsiveness of mathematics educators at the Ukuqonda Institute? We adopted collaborative autoethnography and used two data sets generated from audio recordings captured by the authors. We employed narrative analysis and organised the findings using the characteristics of pedagogical responsiveness as heuristic devices. The findings show that the participants’ pedagogical responsiveness was stimulated by the iterative process of team planning, deliberate implementation, and reflection. The prevalent characteristics were learner interactions, learner focus, inclusivity, dialogue and relationality, knowledge work, social justice, and equity. We recommend that similar studies be conducted targeting pedagogical responsiveness with a focus on other mathematical themes. Furthermore, this study suggests that, to remain pedagogically responsive, there should be constructive alignment among the types of tasks, questions, classroom interactions, and targeted content that underpin mathematics teaching and learning across different educational levels

INFIDELITY AMONGST YOUNG MARRIED COUPLES: SUGGESTIONS FOR SOCIAL WORK INTERVENTION

Infidelity is a common phenomenon in modern society and a major factor in marital dissolution across the globe. A qualitative research approach was used in this study to develop an in-depth understanding of the experiences and impact of infidelity amongst young married couples. The participants were purposively selected from a population of young married couples who had experienced infidelity in their marriage and lived within the municipal borders of Lepelle-Nkumpi, in Limpopo province, using the snowball technique. Tesch’s eight steps were used to analyse the data. To ensure the trustworthiness of the findings, the researchers assessed the qualitative data for credibility, transferability, dependability, and conformability. The findings highlight that young married couples experiencing marital infidelity require direction from social workers to understand the process of recovery from any type of infidelity to bring about improvement and change in their marriage

Greenhouse evaluation of maize performance and changes in chemical properties of soil following application of winery solid waste composts

Thesis (M.Sc.(Soil Science)) -- University of Limpopo, 2015Winery solid waste materials namely, wine filter materials (FM), grape marc (berry stalks, skins and seeds) and chopped grapevine pruning canes were composted in heaps through a thermophilic process. The filter materials were mixed with the grape marc and grapevine prunings at five rates (10%, 25%, 50%, 75% and 100%) to produce five composts herein designated as C10FM, C25FM, C50FM, C75FM and C100FM, respectively. A laboratory incubation study was thereafter carried out to determine the nutrient release potential of the composts using two soil types with varying textural characteristics. Each compost was mixed with soil at a rate equivalent to 200 kg N ha-1 and the mineral N, available P and exchangeable K content determined over 42 days incubation period. Results revealed that the composts possess high C content and low C:N ratios; and released significantly higher NH4-N and K concentration relative to un-amended control. The differences in the amount of P mineralised among the five compost treatments were not significant while significantly higher amount of K was mineralised at higher FM mix rates. The composts were applied to maize cv. SNK2147 on sandy soil in a greenhouse pot study at five rates (5, 10, 20, 40 and 80 t ha-1) to determine their effects on crop growth and yield as well as on selected soil chemical properties. An un-fertilised control and NPK fertiliser treatments were included for comparison. The pots were arranged in a completely randomized design, with each treatment replicated four times. The C50FM, C75FM and C100FM treatments applied at 80 t ha-1 gave significantly higher maize dry matter yield than the NPK fertiliser treatment. Quantitative estimates of the optimum compost rate for dry matter production ranged from 450 to 1842 g pot-1. Application of these composts significantly increased dry matter yield, plant height, stem diameter and the number of functional leaves per plant compared to the un-fertilised control. The K content of shoot from composts treatments exceeded the critical nutritional level of 3.3%. Plant tissue Zn content from C10FM, C25FM and C50FM treatments exceeded the critical nutritional level of 15 mg kg-1 while the residual soil K, Na and Zn contents after crop harvest were significantly increased following compost application. Similarly, the residual P was significantly increased in C25FM, C75FM and C100FM treatments after harvest. In conclusion, application of these composts exerted beneficial effects on maize performance and soil. Field studies under variable conditions are recommended to validate these findings. Keywords: wine, compost, nutrient release potential, maize, soil chemical propertie

IoT Challenges and Issues: A Comprehensive Review of Software Defined Networking and Network Function Virtualization Solutions

The idea behind the Internet of Things (IoT) is to connect everything, including laptops, smartphones, sensors, and other devices, to the Internet. To build an autonomous environment without human intervention. This novel network was used in several industries, including smart homes, smart cities, healthcare, etc. For this reason, IoT networks are growing in infrastructure. As a result, the administration of this vast array of linked devices and produced data becomes more complicated. Thus, a new elastic mechanism is required for this dynamic and rapid evolution in configuration, control, management, etc. Network Function Virtualization (NFV) and Software Defined Networking (SDN) have become essential points in scientific research to overcome IoT challenges such as security, heterogeneity, energy efficiency, interoperability, and more. These two approaches have proven their efficiency in adapting to dynamic and evolving networks. SDN reduces network latency by up to 30% and increases device scalability by 40%. At the same time, NFV optimizes resource allocation, achieving up to a 35% reduction in energy consumption and a 20% decrease in operational costs through virtualized infrastructure. In this review, we systematically analyze solutions designed for IoT systems by developing a state-of-the-art for NFV and SDN and thoroughly researching the various problems that IoT will face. Thus, we compare SDN- and NFV-based IoT solutions to overcome these challenges. Lastly, we will discuss the different obstacles that can lower the performance of SDN/NFV applications on the IoT. The contribution of this review lies in its systematic evaluation and comparison of current NFV and SDN approaches, providing valuable insights and paving the way for future research to enhance the integration and management of IoT systems

Numerical modelling of groundwater flow at Mogalakwane Subcatchment, Limpopo Province : implication for sustainability of groundwater supply

Thesis (M.Sc.(Geology)) -- University of Limpopo, 2022The Limpopo Province is largely underlain by crystalline basement rocks, which are characterised by low porosity and permeability. The climate in this province is arid to semi-arid, with scarce surface water for domestic and industrial use. As a result, groundwater is the prime source of fresh water supply for various uses. The complex geology, the impacts of climate change and man-made interactions with groundwater and surface water are the main threat to the availability of a sustainable source of fresh water in the province. In addition, despite substantial research efforts conducted by academic institutions and government organisations, there is still a gap in understanding quantitatively the dynamics of the hydrological systems in large parts of the Limpopo Province. The present study is therefore focused on the investigation of hydrological stresses that are applied to groundwater and surface water in one of the catchments situated in the Limpopo Province. In this study, a three-dimensional steady-state numerical model of groundwater flow was carried out at Mogalakwena Subcatchment, which is situated in the western sector of the Limpopo Province. The area is situated approximately 40 km northwest of Mokopane and 50 km west of Polokwane town. The research aims to understand the dynamics of the exchange between surface water and groundwater, and to assess the influences of these processes on the sustainability of water supply in the area. Hydrologically, the area falls within the boundaries of the Mogalakwena River Catchment, which forms part of the Limpopo River Basin. Previous studies suggest that there is a continuous decline in groundwater levels in the study area due to extensive use of groundwater for mining, irrigation, and domestic purposes. Furthermore, continued climate changes have altered the rainfall events during the last couple of decades, which consequently had an impact on groundwater recharge, quality, and availability. In addition, the complex geology of the area has an impact on the aquifers’ productivity resulting in variability in borehole yields throughout the study area. To achieve the aims of the research project, a three-dimensional steady-state numerical model of groundwater flow was implemented using MODFLOW NWT and ModelMuse v graphical user interface. The model domain covers an area of 5896 sq. km and was discretised with a grid cell size of 200 m by 200 m. The MODFLOW Packages used include DIS, UPW, RCH, EVT, WEL, GHB, RIV and UZF as well as the ZONEBUDGET. The conceptual model of groundwater flow consists of two layers, and it was developed based on drillhole logs, hydrochemical data, environmental isotopes, geological, digital terrain models, and other spatial data relevant for the conceptualisation of boundary conditions and hydrological stresses. The results of the steady-state simulation of groundwater flow show that recharge contributes 99.6% of inflow, followed by river leakage (0.36%) and GHB (0.08%). Among the outflow components, surface runoff takes the lion’s share (83.3%), followed by evapotranspiration (16.6%) and river leakage 0.02%. The zone budget was implemented to evaluate the interaction between surface water and groundwater by quantifying the amount of water that flows from one zone to the other. This was achieved by assigning zone numbers to the objects that represent boundary conditions (e.g., aquifer, river and dam). Zone 1, 2 and 3 were assigned to the aquifer, river and dam, respectively. The results indicate that the rivers gain more water than they supply to the aquifer. Similarly, the Glen Alpine Dam gain more water from the aquifer than it supplies to the aquifer. This implies that the interaction between surface water bodies such as rivers and dams have a significant impact on the aquifer, which consequently partly contributed to the shortage of water in the area. A predictive analysis of the aquifer’s response to an increase in abstraction rate, evapotranspiration rate and a decrease in recharge was carried out to investigate the future fate of water availability in the study area. The results suggest that as recharge decreases, the river inflow slightly increases to compensate for the declining water level due to the river stage exceeding the piezometric surface. In addition, the decrease in recharge rate is accompanied by a slight decrease in both surface runoff and evapotranspiration rate. Thus, a decline in recharge causes a significant drop in piezometric surface relative to the evapotranspiration extinction depth, which ultimately decreases the rate of evapotranspiration. Similarly, a decrease in recharge rate lowers the depth of the water level below the river stage, which consequently triggers water vi exchange from Mogalakwena River to the aquifer. In general, the water balance shows that as recharge decreases by 20% or more, the outflows exceed the inflows resulting in a continuous drop in water level, which may ultimately risk the availability of groundwater in the area.Council for Geoscience (CGs

Challenges facing provincial departments in records management and disposal : a case study of CoGHSTA in Limpopo Province

Thesis (MPAM.) -- University of Limpopo, 2021The study investigated the challenges faced by CoGHSTA department in records management and disposal with the sole purpose of developing some mechanisms to address the above-mentioned challenges. The study was conducted at CoGHSTA in Limpopo Province. The overall challenges faced in both records management and disposal are discussed. Data was collected from various sources e.g., primary, and secondary sources of data. Literature written by different authors – from international, national, and provincial contexts - namely government legislations, books, journals, websites office records such as procedure manuals and service standards, was investigated, to explore the topic under study. The population for this study was all 21-records management staff within the two divisions of the Information management unit such as general records and human resource records. The study employed a qualitative research approach that relies on phenomenology because the researcher intends to find out what challenges are faced by CoGHSTA records management staff on records management and disposal. The study adopted purposive sampling because its respondents have the characteristics and knowledge to answer the research problem of this study. For this study, data were collected from 17 participants using semi-structured interviews. The study findings revealed the following as major challenges faced in records management: Lack of resources - human and financial; lack of storage facilities; lack of Senior Management support. The following were raised as challenges experienced on the disposal of records: delay in the approval of memo(s) for disposal of records by the Head of Department; delay by the Provincial Archives to give authority to dispose of records; lack of storage facilities for active and inactive records and shortage of staff to arrange records for disposal. It is out of those findings that the study proposed several recommendations which included the need to implement records management policies, standards, guidelines, and procedures. The study recommended that the records management unit be allocated sufficient resources (human and financial) as other units that the department of strategic business deems to be performing the department’s (CoGHSTA) core functions. This is because the records management unit equally plays a key role in the management of the records from various CoGHSTA units which are regarded as core units. It is also recommended that the allocation of storage facilities that meet the records storage xi facilities standard be prioritised and attended to as a matter of urgency because the records management unit could function effectively and efficiently without such an important infrastructure. The study deems it necessary for the Head of Department as the Accounting Officer to delegate - in writing - the authority to the Records Manager or his/her supervisor to sign and approve the memorandum for disposal of records after a thorough appraisal of such records is done by the records staff to avoid the delays that are experienced during the approval of the memorandums. The study further recommends that the Provincial Archives have three (3) to four (4) employees amongst its staff establishment dedicated to each government department dealing with all records management issues including an appraisal of records to address the delay by the Provincial Archives when authorising the disposal of records

A module placement scheme for fog-based smart farming applications

As in Industry 4.0 era, the impact of the internet of things (IoT) on the advancement of the agricultural sector is constantly increasing. IoT enables automation, precision, and efficiency in traditional farming methods, opening up new possibilities for agricultural advancement. Furthermore, many IoT-based smart farming systems are designed based on fog and edge architecture. Fog computing provides computing, storage, and networking services to latency-sensitive applications (such as Agribots-agricultural robots-drones, and IoT-based healthcare monitoring systems), instead of sending data to the cloud. However, due to the limited computing and storage resources of fog nodes used in smart farming, designing a modules placement scheme for resources management is a major challenge for fog based smart farming applications. In this paper, our proposed module placement algorithm aims to achieve efficient resource utilization of fog nodes and reduce application delay and network usage in Fog-based smart farming applications. To evaluate the efficacy of our proposal, the simulation was done using iFogSim. Results show that the proposed approach is able to achieve significant reductions in latency and network usage