Mental Health Consequences of Unemployment: Mental Health, Somatic Symptoms, Depressive Affect and Positive Affect

In this dissertation, we endeavoured to investigate the relationship between mental health and labour market changes in South Africa. We started by understanding the relationship between the aggregate CESD-10 and labour market status and then explored whether this aggregate relationship holds true for each of the three mental health factors that make up the CESD-10 score. Using data from the National Income Dynamics Study, waves 1-5, we documented increasing mental health symptoms with employed to other states of unemployment. This follows for somatic symptoms, depressed affect and positive affect, but the source driving the effects differs between factors and with the CESD-10 as well. We found that those who are NEA suffer to a greater extent in positive affect than in the other two factors relative to the employed. For those who are unemployed (discouraged), we see they also experience the strongest detrimental effect to their positive affect relative to the employed. However, they experience lower depressed affect scores relative to the employed. Those who are unemployed (strict), meanwhile, experience greater depressed affect scores out of the three factors when compared to the employed. As such, we expect to see an average increase in depressive symptoms classifications among those moving from employed to NEA statuses. We can also expect an average increase in depressed affect disorder classifications among those moving from employed to NEA labour force status. Likewise, we can expect higher positive affect across the five waves among those moving from a employed to NEA status. We find that, after controlling for observed individual characteristics and utilizing the panel structure of the data by allowing for individual specific fixed effects, negative labour market shifts have a significant negative impact on mental health. The sub-group analysis shows that this has a particularly adverse effect on black people and males

Diversity and industrial potential of hydrolaseproducing halophilic/halotolerant eubacteria

Halophilic and haloterant eubacteria have been isolated from different marine and hypersaline environments. Halophilic eubacteria also occur in environments typified by more than one soda lakes which are both hypersaline and extremely alkaline. These organisms have been shown to produce a wide array of hydrolytic enzymes including proteases, amylases, xylanases, cellulases as well as lipases and DNases. These enzymes are commonly applied in the production of fermented food and food supplements, in animal feed, laundry detergents and textile industries. Several studies have shown that enzymes derived from halophilic and halotolerant eubacteria are not only halostable but may also be thermostable and alkalistable. This extremophilicity make the enzymes suitable candidates in various fields of biotechnology and may even open up new application opportunities

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

The Diversity and Dynamics of Indigenous Yeast Communities in Grape Must from Vineyards Employing Different Agronomic Practices and their Influence on Wine Fermentation

The current study evaluated the diversity of yeast species in Cabernet Sauvignon grape must derived from three neighbouring vineyards from a similar terroir but on which significantly different management practices are employed. The fermentation kinetics and yeast population dynamics were monitored from the beginning to the end of spontaneous fermentation. The grape musts were characterised by distinct yeast populations comprising oxidative, weakly fermentative and strongly fermentative yeasts. Different combinations of dominant non-Saccharomyces yeasts were observed in each must, with significantly different assortments of dominant species, including Starmerella bacillaris (synonym Candida zemplinina), Lachancea thermotolerans, Hanseniaspora uvarum, Candida parapsilosis and Wickerhamomyces anomalus. None of these yeast consortia appeared to affect the growth of Saccharomyces cerevisiae or inhibit the overall progress of fermentation. However, the percentage of fermentative yeasts was positively correlated with the fermentation rate. Glucose and fructose consumption rates suggested active participation of both glucophilic and fructophilic yeasts from the onset of fermentation. The data highlight two parameters, viz. initial cell concentration and yeast community composition, as important fermentation drivers and open the possibility to predict fermentation behaviour based on the initial composition of the yeast community

Fungicides and the grapevine wood mycobiome: a case study on Tracheomycotic Ascomycete Phaemoniella chlamydospora reveals potential for two novel control strategies

Original ResearchPhaeomoniella chlamydospora is a tracheomycotic fungus that colonizes the xylem of grapevines (Vitis vinifera L.), causing wood discoloration, brown wood streaking, gummosis, and wood necrosis, which negatively affect the overall health, productivity, and life span of vines. Current control strategies to prevent or cope with P. chlamydospora infections are frequently ineffective. Moreover, it is unclear how fungicides commonly applied in vineyards against downy and powdery mildew agents affect the wood mycobiome, including wood pathogens such as P. chlamydospora. In this study, we used next-generation sequencing to assess the effects of foliar spray of grapevines with inorganic (copper oxychloride and sulfur), synthetic (penconazole and fosetyl-aluminum), and natural (Blad) fungicides currently used against the downy and powdery mildews. The subjects of our investigation were (i) the resident wood mycobiome, (ii) the early colonization by a consortium of fungal wood endophytes (ACEA1), (iii) the wood colonization success of P. chlamydospora, and (iv) the in planta interaction between P. chlamydospora and ACEA1, under greenhouse conditions, in rooted grapevine cuttings of cv. Cabernet Sauvignon. The data obtained suggest that the resident mycobiome is affected by different fungicide treatments. In addition, the early colonization success of the endophytes composing ACEA1 varied in response to fungicides, with relative abundances of some taxa being overrepresented or underrepresented when compared with the control. The wood colonization by P. chlamydospora comported significant changes in the mycobiome composition, and in addition, it was greatly affected by the foliar spray with Blad, which decreased the relative abundance of this pathogen 12-fold (4.9%) when compared with the control (60.7%) and other treatments. The presence of the pathogen also decreased considerably when co-inoculated into the plant with ACEA1, reaching relative abundances between 13.9% and 2.0%, depending on the fungicide treatment applied. This study shows that fungicides sprayed to prevent infections of powdery and downy mildews have an control strategies to fight P. chlamydospora, namely, the foliar spray with Blad and the use of ACEA1. Further studies to confirm these results are requiredinfo:eu-repo/semantics/publishedVersio

Isolation of hydrolase producing bacteria from Sua pan solar salterns and the production of endo-1, 4-bxylanase from a newly isolated haloalkaliphilic Nesterenkonia sp.

Eighty seven bacterial isolates were obtained from evaporator ponds using culture enrichment technique and screened for xylanase, mannanase and cellulase activity. Based on biochemical and phenotypic characteristics, the isolates were divided into 18 groups. Thirteen groups were Bacillusspecies, four were Halomonas species, while one group belonged to the genus Nesterenkonia. Four Bacillus isolates, Sua-BAC005, Sua-BAC012, Sua-BAC017 and Sua-BAC019, as well as Nesterenkonia sp. Sua-BAC020 were studied further. Isolate Sua-BAC005 affiliated with Bacillus amyloliquefaciens secreted 12.6 U/ml and 9.0 U/ml b-mannanase and b-xylanase, respectively, while isolates Sua-BAC012, Sua-BAC017 and Sua-BAC019 affiliated with Bacillus licheniformis, produced less than 2 U/ml of xylanase, cellulase and mannanase. Nesterenkonia sp. Sua-BAC020 grew at 0 – 20% NaCl with anoptimum at 2.5% NaCl, and at pH 7 – 9.5 with an optimum at pH 9. This isolate produced 3.5 U/ml xylanase when cultivated at pH 8 in 10% NaCl. Five xylanase activity bands were detected on Native-PAGE coupled with zymogram

Non-Saccharomyces Killer Toxins: Possible Biocontrol Agents Against Brettanomyces in Wine?

Red wine spoiled by the yeast Brettanomyces bruxellensis is characterised by off-odours commonlydescribed as horse sweat, phenolic, varnish and band-aid. The growth of this yeast in wine is traditionallycontrolled by the use of sulphur dioxide (SO2). However, the concentration of SO2, the pH of the wine,the presence of SO2-binding chemical compounds in the wine, as well as the strain of B. bruxellensis,determine the effectiveness of SO2. Other chemical preservatives have been tested, but are not much moreefficient than SO2, and methods used to clean barrels are only partially effective. Filtration of wine andthe use of electric currents/fields are also reported to alter the physical and sensory properties of wine. Inthis context, alternative methods are currently sought to achieve full control of this yeast in wine. Killertoxins have recently been proposed to fulfil this purpose. They are antimicrobial compounds secretedby Saccharomyces and non-Saccharomyces yeasts, displaying killer activity against other yeasts andfilamentous fungi. They are believed to play a role in yeast population dynamics, and this killer phenotypepotentially could be exploited to inhibit the growth of undesired microorganisms within a microbialecosystem such as that occurring in wine. In this review, non-Saccharomyces killer toxins are describedand their potential application in inhibiting B. bruxellensis in wine is discussed in comparison to othertried methods and techniques

A Shotgun Metagenomic Sequencing Exploration of Cabernet Sauvignon Grape Must Reveals Yeast Hydrolytic Enzymes

Shotgun sequencing was employed to explore the community structure (phylotyping of rRNA genes) andfunctional potential of Cabernet Sauvignon grape must microbiome. A metagenomic library, representing92.6 Mb of genetic information, was generated from DNA obtained from Cabernet Sauvignon grapemust.. Fungi were identified as the dominant domain (59.5%) followed by Streptophyta (39%). Amongthe 84 fungal species, 22 were yeasts of various genera. Additionally, grapevine endophytes such asDavidiella sp., Botryotinia fuckeliana, Alternaria sp., and Cladosporium sp. were identified. An unusuallyhigh prevalence of Mucor spp. was evidenced. Functional annotation revealed sequences of genesinvolved in metabolism (35.6%), followed by poorly characterized categories (28.3%), cellular processesand signalling (18.4%), and finally information storage (17.8%). Among the former, glycosidases wereabundant followed by glycogen debranching enzyme, 6-phosphofructokinase and trehalose-6-phosphatesynthase. Furthermore, the taxonomic analysis of the functional sequence data exhibited the eukaryoticgene pool that predominantly contains sequences derived from Streptophyta (mainly Vitis vinifera) 60% >Ascomycota (32%) > Basidiomycota (5%) > Bacteria (2.5%). Finally, sequences of a variety of hydrolyticenzymes of potential oenological relevance were retrieved, thereby confirming that grape juice is a richreservoir for valuable biocatalysts that should be explored further

Determining the level of condom use and associated factors among married people in Tshwane District of South Africa

Introduction: despite the wide availability of free male condoms in South Africa, high rates of new HIV transmissions are reported to occur among married couples. The aim of this study was to determine the level of condom use among the married people and to assess the factors associated with condom use in the Tshwane district of the Gauteng province. Methods: a cross-sectional study was conducted among 325 clients accessing health care services at the Steve Biko Academic Hospital. A self- administered questionnaire was used to collect data, which were entered onto an Excel spreadsheet and imported into Epi info version 7 for analysis. A logistic regression model was used to investigate the association between condom use and the explanatory variables. The odds ratio was used to measure the strength of the associations. The 95% CI and a cut-off point of 0.05 for the p-value were used to indicate statistical significance. Results: the mean age of the participants was 41.6 years (SD=7.7). Two hundred and seventy-six (276; 85%) of the 325 participants reported not using condoms. Trust, doing regular HIV testing, and refusal by the husband were among the reasons given for not using condoms. In this study it was found that, the level of education, age and employment status were the determinants of condom use. Conclusion: the level of condom use was low and sero-discordance was found to be the primary motivator for condom use. This study recommends the strengthening of and the widespread implementation of the CVCT service

Machine Learning for Decision-Support in Distributed Networks

Student Number : 9801145J - MSc dissertation - School of Electrical and Information Engineering - Faculty of EngineeringIn this document, a paper is presented that reports on the optimisation of a system that assists in time series prediction. Daily closing prices of a stock are used as the time series under which the system is being optimised. Concepts of machine learning, Artificial Neural Networks, Genetic Algorithms, and Agent-Based Modeling are used as tools for this task. Neural networks serve as the prediction engine and genetic algorithms are used for optimisation tasks as well as the simulation of a multi-agent based trading environment. The simulated trading environment is used to ascertain and optimise the best data, in terms of quality, to use as inputs to the neural network. The results achieved were positive and a large portion of this work concentrates on the refinement of the predictive capability. From this study it is concluded that AI methods bring a sound scientific approach to time series prediction, regardless of the phenomena that is being predicted