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Anxiety associated with the use of technology among teachers in Lesotho
(University of Zululand, 2016) Tlaba, David Tlaba; Sibaya, P.T. and Sibaya, D.C.
The purpose of this study is to investigate anxiety associated with the use of technology among teachers in Lesotho. The sample consists of 100 high school teachers from various schools located in the Maseru district. To meet the objectives, a questionnaire was designed, which collected data on teachers’ anxieties towards technology in relation to demographic variables. The findings of the study suggest that the educators do differ in their anxiety levels in relation to technology, and that there is no correlation between age and anxiety. The relationship between the variable of gender and anxiety is revealed. Furthermore, teaching experience is found to have a significant effect on anxiety, while nationality is found to have no effect on anxiety.
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In vitro antioxidant and antibacterial activity of Crude extracts of some freshwater cyanobacteria
(University of Zululand, 2023) Ikhane, Olufemi Akayagboke Albert; Opoku, A.R Osunsanmi, F.O. and Mosa, R.A
Commonly available antibiotics are increasingly becoming ineffective due to the astronomic rise of antimicrobial resistance (AMR). As a result, there is a need for the discovery of new antibiotics and antioxidants from natural products. Cyanobacteria possess a myriad of significant secondary metabolites among which potential antibacterial and antioxidant could be found. The aim of this study was to exploit the potential metabolite reservoir of cyanobacteria towards the development of novel antimicrobial compounds. Freshwater cyanobacteria, Cylindrospermum alatosporum NR125682.1 and Loriellopsis cavenicola NR117881.1, utilized in this study were isolated from Vulindlela area, KwaZulu-Natal, SA. They were propagated on BG-11 media, identified, and characterized through 16S rRNA sequencing. The cyanobacteria were sequentially extracted with hexane, dichloromethane (DCM) and ethanol. The extracts were screened for their antioxidant capacity using DPPH, ABTS, OH* radicals and metal chelating potential. The in silico molecular docking of the major constituents of the extracts against β-lactamase was also evaluated. The in vitro antibacterial potential of the extracts was evaluated using the broth microdilution method against some selected gram-positive and gram-negative clinical bacterial isolates. The effect of the extracts on the bacterial membranes was evaluated using the lactate dehydrogenase assay. The efflux pump inhibitory potential was investigated by measuring the percentage cytoplasmic accumulation of rhodamine. Beta-lactamase inhibitory potential was investigated along with synergistic potential when combined with erythromycin. The ability of the extracts to effect DNA damage was also evaluated. The crude extracts were moderate antioxidants, scavenging free radicals with IC50 range of 6-10 μg/ml and metal chelating efficiency IC50 values ranging from 44-72 μg/ml. Despite the encouraging (-6.6, -6.3 kJmol-1) binding affinity of some of the phytochemicals in the extracts following molecular docking against beta-lactamase, the in vitro inhibition of beta-lactamase indicates that all six extracts were poor inhibitors of the enzyme with a high IC50 value of 5.6 mg/ml. The ethanol crude extract of both isolates was the most efficient with a minimum MIC value of 0.7 mg/ml against the tested resistant bacteria. The ethanol extract of Loriellopsis cavenicola NR117881.1 effectively inhibited efflux pump activity, with up to 60% rhodamine accumulation in the bacteria tested. The extracts effected cell membrane damage on the tested bacteria. The extract also exhibited synergism when combined with erythromycin against some of the tested bacteria. Only the DCM extract of Loriellopsis cavenicola NR117881.1 effected DNA damage. The various bioactivity exhibited by the extracts suggest potential for the development of antibacterial and antioxidant active agents with multiple beneficial effects.
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Effects of particles’ size and composition on magnetic properties of substituted ferrite nanoparticles
(University of Zululand, 2024) Majozi, Prince Phathizwe; Msomi, J. Z. and Jili, T. P.
This project presents the effects of particle size and composition on the magnetic properties of ferrites investigated by magnetization and electron spin resonance (ESR) spectroscopy. CuxMn1−xFe2O4, (Zn, Cd)Fe1.2Al0.8O4, NixCo1−xFe2O4 and Cu0.5Ni0.5Fe2O4 nanoferrites were produced by glycol-thermal reaction under a low reaction temperature of 200 ◦C. Structural properties were analysed by transmission electron microscopy (TEM) and X-ray diffraction (XRD). For CuxMn1−xFe2O4, the majority of the XRD peaks were indexed to the cubic spinel phase. However, a small impurity peak at 2θ ≈ 52◦ attributed to α-Fe2O3 and Mn2O3 phases for samples 0.4≤ x ≤ 0.8 was observed. The particle sizes varied between 8 nm and 16 nm. The particle size for the sample x = 0.3 (Cu0.3Mn0.7O4), which did not show any impurity phases was about 8 nm. The reduction of lattice parameters as a function of increasing Cu content is attributed to the smaller Cu replacing Mn ions. Magnetization data revealed superparamagnetic Cu0.3Mn0.7Fe2O4 fine particles and spin-glass behaviour. Enhanced magnetization and coercive fields at 10 K were explained by the core-shell model and spin freezing. An attempt to produce (Zn, Cd)Fe1.2Al0.8O4 was made. The XRD spectrum of the Cd-based sample showed impurity phases. XRD analysis showed clean ZnFe1.2Al0.8O4 with a particle size of about 6 nm. TEM images revealed nearly spherical particles with a reasonably narrow distribution of particle size which compared well with the value estimated from XRD data. ESR measurements showed a single-line signal indicative of dominant superexchange interactions. A small peak at very low magnetic field (about -500 ≤ H ≤ 500 G) was observed for the Zn- based oxide annealed at 1000 ◦C. This anomalous peak may be due to the low field microwave absorption(LFMA) phenomenon that is not fully understood in magnetic materials. NixCo1−xFe2O4 were successfully indexed to the cubic spinel. An additional peak associated with α-Fe2O3 was observed for samples with 0.7 ≤ x ≤ 0.9. XRD spectra revealed crystallite sizes ranging from 8 nm to 13 nm. There was no significant change in lattice parameters with increasing Ni concentration due to the small difference in their atomic radii. The ESR results showed single-line signals. Additional resonances were observed at low fields which need further measurements. We suspect these additional resonance peaks to be due to LFMA. The Land´e g-values varied between 1.98 and 3.6. Nanosized Cu0.5Ni0.5Fe2O4 fine particles with particle sizes of about 12 nm were produced. XRD did not show any impurity phases. The as-prepared oxide was annealed from 500 ◦C to 1100 ◦C to investigate particle size effects. Grain growth to about 46 nm was observed after annealing at 900 ◦C. ESR data revealed enhanced magnetization on the sample annealed at 900 ◦C due to the large ferromagnetic domains.
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The confusion of work and real life.
(2023) Madibi, Zizipho.
Society seems to think work is what makes a human being...........................
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Interaction of nitrogen fertilizer rates and plant population on growth, phenology, yield, and nutritional composition of Solanum scabrum
(2023) Ndlovu, Sindi; van Jaarsveld, C.M. Mavengahama, S. and Ntuli, N.R.
Solanum scabrum is a nutritious African leafy vegetable scarcely known in South Africa but consumed in other African countries. Very little is known about the agronomic requirements of this crop, including optimum fertilizer rates and plant population. This study focused on the effect of N fertilizer application and plant population on the growth, phenology, yield, and nutritional composition of S. scabrum. A field experiment was conducted at the University of Zululand farm in which S. scabrum was grown under 0, 100, 200, 300, and 400 kg ha-1 N (as limestone ammonium nitrate) and 100 000, 160 000, 220 000, and 280 000 plants per hectare in a randomised complete block design with three replications. Five randomly selected plants from the inner rows of each plot were marked and used to take measurements of vegetative traits (on plant height, leaf chlorophyll content, leaf area, and the number of leaves and branches) 35 days after transplanting. Phenological development of reproductive traits was recorded as duration (days after transplanting) to 50% flowering, fruit formation, and fruit maturity, using plants from the border rows. Plants from inner rows were harvested to measure marketable and non-marketable yield in fresh and dry mass (g). Ten centimetre long shoot tips were harvested for marketable yield at 35 and 56 days after transplanting. However, the non-marketable yield was determined from all aboveground parts harvested at 5 cm above soil level at the termination date. The same shoot tips were analysed for their N, P, K, Ca, Mg, Na, Al, Zn, Mn, Cu, and Fe content. Plant height and leaf area generally increased, but leaf chlorophyll content and the number of branches and leaves were inconsistent with an increase in N application. The effect of population size on plant height, the number of branches and leaves, leaf area, and leaf chlorophyll content were inconsistent. Nitrogen application of 300 and 400 kg ha-1 N and a low plant population (100 000 plants ha-1) increased the days to 50% flowering. Generally, applying N resulted in higher values for all yield parameters measured in this study. Further, yield parameters were higher at the lowest plant population (100 000 plants ha-1). Nitrogen application did not affect N, K, and Ca content, but reduced P content of the shoots. Its effect on the shoot Mg content was variable. Application of N had an inconsistent effect on the shoots’ Na, Zn, Cu, and Fe content. However, it reduced and increased the shoots’ Al and Mn content, respectively. Variation in plant population did not affect the macronutrients, whereas the application of N had an inconsistent effect on some micronutrients. The application of 300 kg ha– 1 was the optimum range for N fertilizer application, and 100 000 plants ha-1 was the optimum plant population relative to shoot fresh mass. This indicates potential for improving the crop through N fertilization, thereby contributing to food security and balanced diets in rural households in South Africa.