12 research outputs found
Metabolomic profiling and 16 S rRNA metabarcoding of endophytes of two Aloe species revealed diverse metabolites
No full textAbstract Aloe species are often used interchangeably for medicinal and cosmeceutical applications, presenting a challenge to the biological efficacy consistency of some herbal preparations. Sustainable production of high-quality commonly used medicinal plants remains a limitation for commercialisation. Thus, this study investigated the potential for plant substitution by examining bacterial endophytes capable of producing similar host plant secondary metabolites. The metabolite profiles and endophytic bacterial communities of endangered Aloe lettyae were compared with those of Aloe longibracteata using nuclear magnetic resonance spectroscopy and 16 S rRNA gene sequencing. Only 15 metabolites were significantly different between A. lettyae and A. longibracteata based on metabolite concentrations. However, both plants’ functionality and potential application remain comparable. Phytohormones, including indole-3-acetate and 5-hydroxyindole-3-acetate, were more concentrated in A. lettyae than A. longibracteata. Metabolites such as tyrosine, allantoin, and myo-inositol, with human health benefits, were annotated in both species. Aloe lettyae harboured a phylogenetically diverse bacteria community compared to A. longibracteata, with a higher richness of bacterial species, indicating a likelihood of diverse metabolic capabilities among the bacteria. Dominant endophytes, including Bacillus, Comamonas, and Pseudomonas, possess enzymes contributing to various metabolic pathways. The enzymes have the potential to impact the synthesis, or breakdown of plant metabolites, consequently influencing the overall metabolic composition of the host plant. Therefore, this study supports the interchangeability of A. lettyae and A. longibracteata due to their ability to produce similar metabolites, and although the Aloe species exhibit phylogenetically diverse endophytic communities, the feasibility of utilizing their endophytes as producers of secondary metabolites remains viable. Graphical abstrac
Metabolomic profiling and 16 S rRNA metabarcoding of endophytes of two Aloe species revealed diverse metabolites
No full textJournal Article, Faculty of Natural and Agricultural Science, North--West UniversityAloe species are often used interchangeably for medicinal and cosmeceutical applications, presenting a challenge to the biological efficacy consistency of some herbal preparations. Sustainable production of high-quality commonly used medicinal plants remains a limitation for commercialisation. Thus, this study investigated the potential for plant substitution by examining bacterial endophytes capable of producing similar host plant secondary metabolites. The metabolite profiles and endophytic bacterial communities of endangered Aloe lettyae were compared with those of Aloe longibracteata using nuclear magnetic resonance spectroscopy and 16 S rRNA gene sequencing. Only 15 metabolites were significantly different between A. lettyae and A. longibracteata based on metabolite concentrations. However, both plants’ functionality and potential application remain comparable. Phytohormones, including indole-3-acetate and 5-hydroxyindole-3-acetate, were more concentrated in A. lettyae than A. longibracteata. Metabolites such as tyrosine, allantoin, and myo-inositol, with human health benefits, were annotated in both species. Aloe lettyae harboured a phylogenetically diverse bacteria community compared to A. longibracteata, with a higher richness of bacterial species, indicating a likelihood of diverse metabolic capabilities among the bacteria. Dominant endophytes, including Bacillus, Comamonas, and Pseudomonas, possess enzymes contributing to various metabolic pathways. The enzymes have the potential to impact the synthesis, or breakdown of plant metabolites, consequently influencing the overall metabolic composition of the host plant. Therefore, this study supports the interchangeability of A. lettyae and A. longibracteata due to their ability to produce similar metabolites, and although the Aloe species exhibit phylogenetically diverse endophytic communities, the feasibility of utilizing their endophytes as producers of secondary metabolites remains viabl
Publisher Correction to Quantifying intra-urban socio-economic and environmental vulnerability to extreme heat events in Johannesburg, South Africa(International Journal of Biometeorology, 10.1007/s00484-025-02971-y)
No full textIn the originally published version of this article, Aakin Bobola, was mistakenly listed as an author. This was an error introduced during typesetting and has since been corrected. The correct list of authors is: Craig Parker, Craig Mahlasi, Tamara Govindasamy, Lebohang Radebe, Nicholas Brian Brink, Christopher Jack, Madina Doumbia, Etienne Kouakou, Matthew Chersich, Guéladio Cissé, and Sibusisiwe Makhanya for the HE2AT Center Group Springer apologizes for the oversight and any confusion this may have caused. The original article has been corrected.</p
Metabolomic analysis of Sclerocarya birrea (A. Rich) Hochst : to determine the differences in chemical profile and anti-diabetic properties in relation to geographical distribution
No full textMetabolomics is a discipline where metabolites are assessed, identified and quantified in different samples. Metabolites are crucial components of the biological system and highly informative about its functional state due to the closeness to functional endpoints and to the organism’s phenotypes. 1H NMR and LC-MS, the commonly used metabolomics analytical platforms were used to annotate the metabolites found in Sclerocarya birrea (S. birrea) leaves from five South African provinces, Limpopo (L), Gauteng (G), North West (NW), Mpumalanga (M) and KwaZulu-Natal (KZN). Supervised Orthogonal Partial Least Square – Discriminant Analysis (OPLS-DA) of the full spectra revealed a clear differentiation of S. birrea leaves from five provinces. In addition, the level of common metabolites were measured and compounds previously found to have anti-diabetes potential ((-)-epicatechin 3-0-galloyl ester, myricetin-3-0-α-L-rhamnopyranoside, gallic acid and Kaempferol-3-0-α-L-rhamnopyranoside) were annotated in the samples. The samples from the five provinces showed anti- diabetic activity when exposed to an in-vitro glucose uptake assay, with the highest activity observed in male samples from M. The sample presented high concentrations of (-)-epicathechin 3-0-galloyl ester, one of the metabolites with anti-diabetes activity. Overall 1H NMR and LC-MS metabolic profiling were successfully applied to discriminate all five sources of S. birrea leaves, and obtained qualitative information of many common metabolitesM. Sc. (Agriculture)Agriculture, Animal Health and Human Ecolog
The nature of school organisational cultures of well-performing previously disadvantaged secondary schools
No full textMEd (Educational Management and Leadership), North-West University, Vanderbijlpark CampusThe culture of an organisation influences the behaviour and the performance of the entire organisation. This qualitative phenomenological study aimed to investigate the nature of organisational culture in previously disadvantaged, well performing secondary schools in the Metsimaholo Municipality.
The study focused on three questions regarding organisational cultures of these schools, namely, what the nature of organisational culture is; what the nature of organisational cultures of previously disadvantaged, well performing, secondary schools is in the Metsimaholo Municipality is; and what lessons can be derived from the school organisational cultures of previously disadvantaged, well performing secondary schools.
The literature reviewed revealed main aspects of organisational culture as being tangible and intangible manifestation and indicated four types of organisational cultures prevalent in organisations such as schools. To this end, the findings of the study indicated that the schools’ organisational cultures were driven by intangible aspects manifested in philosophic convictions, values and their deeply held beliefs. These aspects shaped the schools’ members’ organisational behaviours and were all geared towards good performance and learner development into useful members of their communities. Moreover, the intangible aspects were also manifested in tangible aspects such as the visual, behavioural and verbal manifestations, which resonates which literature on organisational culture.
It was also found that the schools displayed two dominant types of organisational cultures, namely, the clan and the market cultures. The former was found to pertain to collegial behaviours characterised by cooperation and team work while the latter was found to be a function of principals’ exercise of democratic and autocratic leadership styles as dictated by the different situations. This was evidence of the pivotal role of school principals in shaping the organisational cultures of their schools.
Lessons derived from the organisational cultures of the schools in the study were mainly the importance of schools having a strategy within structures that promoted behavioural patterns of behaviours that promote good performance.Master
Anti-HIV activity of southern African plants: Current developments, phytochemistry and future research
No full textLeading the African agenda or following the African consensus? South Africa's implementation of the African agenda in the United Nations Security Council
No full textLimited immunogenicity of HIV CD8+ T-cell epitopes in acute clade C virus infection
No full textBackground. Human immunodeficiency virus type 1 (HIV-1)–specific CD81 responses contribute to the decline in acute peak viremia following infection. However, data on the relative immunogenicity of CD81 T-cell epitopes during and after acute viremia are lacking. Methods. We characterized CD81 T-cell responses in 20 acutely infected, antiretroviral-naive individuals with HIV-1 subtype C infection using the interferon-c enzyme-linked immunosorbent spot assay. Eleven of these had not fully seroconverted at the time of analysis. Viruses from plasma were sequenced within defined cytotoxic T-lymphocyte (CTL) cell epitopes for selected subjects. Results. At approximately 28 days after estimated initial infection, CD81 T-cell responses were directed against an average of 3 of the 410 peptides tested (range, 0–6); 2 individuals had no detectable responses at this time. At 18 weeks, the average number of peptides targeted had increased to 5 (range 0–11). Of the 56 optimal Gag CTL epitopes sequenced, 31 were wild-type in the infecting viruses, but only 11 of 31 elicited measurable CD81 T-cell responses. Conclusions. These data demonstrate that the majority of CD81 responses are not elicited during acute HIV infection despite the presence of the cognate epitope in the infecting strain. There is a need to define factors that influence lack of induction of effective immune responses and the parameters that dictate immunodominance in acute infection
Employer perspectives on domestic employment relationships in post-apartheid South Africa
No full textIncludes bibliographical references.This dissertation investigates the relationships between domestic workers and employers, as reported by employers, concentrating on food provision as a central dimension. It applies anthropological and sociological approaches that include 10 focus group discussions, 171 completed questionnaires (open- and closed-answer questions) and 10 home observation sessions. The employer sample group is almost exclusively white, middle class, female, English-speaking, tertiary educated residents of Cape Town, South Africa. The research starts from the premise that domestic employment Is an illuminating sphere for analysing the intersection between race, class and gender at the present time in South Africa. It argues that, through an examination of the domestic worker employment relationship, particularly when viewed through the lens of food provision, It becomes possible to judge the extent to which these relationships have changed since the end of apartheid. The research shows that, while a proportion of individual relationships have changed in positive ways, many remain determined by the habituated norms and codes of apartheid-era employment. The study found that the relationship is characterised by contradictions in the attitudes and behaviour of employers, exacerbated by ambiguous communication and employer discomfort and feelings of guilt about past, and present, inequalities. Employer unease and discomfort were particularly evident in the company of peers and in relation to the question of employer responsibility towards workers. The study also found that age and income influenced employer attitudes
On the pathway to better birth outcomes? A systematic review of azithromycin and curable sexually transmitted infections.
No full textThe WHO recommends the administration of sulfadoxine-pyrimethamine (SP) to all pregnant women living in areas of moderate (stable) to high malaria transmission during scheduled antenatal visits, beginning in the second trimester and continuing to delivery. Malaria parasites have lost sensitivity to SP in many endemic areas, prompting the investigation of alternatives that include azithromycin-based combination (ABC) therapies. Use of ABC therapies may also confer protection against curable sexually transmitted infections and reproductive tract infections (STIs/RTIs). The magnitude of protection at the population level would depend on the efficacy of the azithromycin-based regimen used and the underlying prevalence of curable STIs/RTIs among pregnant women who receive preventive treatment. This systematic review summarizes the efficacy data of azithromycin against curable STIs/RTIs
