Cytotoxicity and effect of extraction methods on the chemical composition of essential oils of Moringa oleifera seeds

Renewed interest in natural materials as food flavors and preservatives has led to the search for suitable essential oils. Moringa oleifera seed essential oil was extracted by solvent-free microwave and hydrodistillation. This study assessed its chemical constituents. Cytotoxicity of the oils was investigated using hatchability and lethality tests on brine shrimps. A total of 16 and 26 compounds were isolated from the hydrodistillation extraction (HDE) and solvent-free microwave extraction (SME) oils, respectively, which accounted for 97.515% and 97.816% of total identifiable constituents, respectively. At 24 h when the most eggs had hatched, values of the SME (56.7%) and HDE (60.0%) oils were significantly different (P<0.05) from those of sea water (63.3%) and chloramphenicol (15.0%). Larva lethality was different significantly (P<0.05) between HDE and SME oils at different concentrations and incubation periods. The median lethal concentration (LC₅₀) of the oils was >1000 mg/ml recommended as an index for non-toxicity, which gives the oil advantage over some antioxidant, antimicrobial, therapeutic, and preservative chemicals.     

The experience of introducing secure e-assessment in a South African university first-year foundational ICT networking course

This article illustrates the experience of introducing e-assessment to a foundational ICT networking course for a ‘large’ group of first-year students at a South African Higher Education Institution. The study employed a mix of participatory action research, systems design, and survey (quantitative and qualitative) analysis over an academic year across two semesters. Although much research has been conducted on teaching in ICT, the purposeful pedagogical use of electronic assessment is limited. The results provide insight into the need for ‘extending’ the scholarship of teaching and learning to the scholarship of teaching, learning and assessment. While the research has some limitations in longitudinal and comparison studies, it is useful to students, teaching instructors, lecturers and administrators as it provides key thoughts as guidelines for introducing and using e-assessments as platforms for active learning, and as a basis for future research into the use of e-assessment for high-stake summative assessment.     

Silver and Gold We Have None But What We Have, We Give Unto Thee: Indigenous African Counselling and the Rest of the World

This paper examines the complimentary roles and functions of African indigenous counselling in relationship with non-African forms of counselling. This paper is premised on the view that all forms of counselling, whether African or Western, stand to gain a lot from one another via collaboration and the cross fertilization of ideas. This paper examines the counselling and therapeutic contents of African language, African indigenous education, African indigenous counselling and social practices using the Yoruba culture of Western Nigeria as a reference point. Furthermore, the paper practically examines how the traditional therapeutic resources of African language, African traditional education and African indigenous counselling practices could complement non-African counselling culture. The paper advocates for the evolution of a somewhat global orientation to professional helping. This is possible if counselling practitioners from different cultural orientations develop interest in learning how different counselling cultures could complement one another. This orientation may contribute to mutual self-renewal and self-refinement for all forms of counselling. This paper primarily intends to promote the culture of sharing ideas, practices and concepts from different cultural orientations so that we may develop the mentality of a universal approach to employing counselling strategies to solve humanity's problems.     

Biomolecular characterization,identification, enzyme activities of molds and physiological changes in sweet potatoes (<Emphasis Type="Italic">Ipomea batatas</Emphasis>) stored under controlled atmospheric conditions

Microbial attacks during storage are one of the primary causes of product deterioration, and can limit the process of prolonging the shelf-life of harvested food. In this study, sweet potatoes were stored at temperatures of 13, 21, and 29 °C for 4 weeks. Samples were collected during storage and plated on potato dextrose agar, from which axenic mold cultures were obtained and identified using 26S rRNA gene sequences. Physiological changes of potato tubers were assessed with respect to pathogenicity, enzyme activity, and atmospheric storage conditions. Six fungal species were identified, namely Penicillium chrysogenum (P. rubens), P. brevicompactum, Mucor circinelloides, Cladosporium cladosporiodes, P. expansum, and P. crustosum. The following fungal isolates, namely P. expansum, P. brevicompactum, and Rhizopus oryzae, were recovered from the re-infected samples and selected according to their levels of enzyme activity. This study revealed high levels of activity for cellulase and pectinase, which were most notable during the initial three days of testing, and were followed by a steady decrease (P<0.05). Polygalacturonase activity was prominent with values ranging from 12.64 to 56.79 U/mg (P. expansum) and 18.36 to 79.01 U/mg (P. brevicompactum). Spoilage was obvious in the control group, which had a 100% decay at the end of the experimental period compared with samples treated with iprodione and sodium hypochlorite, in which the decay rates were 5% and 55%, respectively. The data for the iprodione- and sodium hypochlorite-treated samples at the end of the 3-month storage period showed that they were significantly different (P=0.041), with the sodium hypochlorite-treated samples producing twice the rate of infection compared to the iprodione-treated samples. The comparative rate of the progression of decay in the treated samples can be expressed as iprodione<sodium hypochlorite<control. This study demonstrates that sweet potato tissue damage is due to the activities of microbial enzymes and, in particular, the pectinases of the organisms isolated from the infected potato tissues, and suggests the advantages of utilizing iprodione as a curing agent for potato tubers before storage.     

Open and distance education as a strategy for human capital development in Nigeria

The development of human capital has been identified as the most important component of all the factors employed in production economics. Since independence in 1960, Nigeria has placed great emphasis on training and education for human capital formation. However, the education process as the primary means of developing human resource has failed, in its conventional mode, to fulfil the needs of the country. This paper therefore examines the impact of open and distance learning on the human capital development processes in teacher education and other areas in Nigeria, presenting an overview of human capital development efforts in Nigeria with a focus on the tertiary education system. The study also maps out the potential benefits and logical justifications for the application of distance learning systems in the training and development of professionals for the industrial and corporate sectors of the economy. In conclusion, a proposal is made for the full‐scale adoption of open and distance learning as a fundamental strategy for human resource development in the country.     

Conservation of indigenous medicinal botanicals in Ekiti State, Nigeria

INTRODUCTION Ekiti State (about 7000 km2, Inland area) is situ- ated between 7°25′ and 8°20′ North and 5°00′ and 6°00′ East in the rainforest belt of southwestern Ni- geria (EKSG, 1997; Kayode, 1999; 2000). The state which was previously rich in botanicals is now being confronted with massive deforestation due to increase in population, urbanization, uncontrolled logging, lumber being used as fuel and developmental activi- ties since the state was created in 1996. Although stud…