Studies on acoustic properties of non-woven fabrics

This study is divided in to two main parts. The first part deals with the optimization of process parameters of needle-punched non-woven fabrics for achieving maximum sound absorption by employing a Box-Behnken factorial design. The influence of fibre type, depth of needle penetration and stroke frequency on sound absorption properties were studied. These parameters were varied at three levels during experimental trials. From multiple regression analysis, it was observed that the depth of needle penetration alone was the most dominant factor among the selected parameters, which was followed by the interaction between depth of needle penetration and stroke frequency. Fibre type was the least dominant parameter affecting sound absorption. A maximum sound absorption coefficient of 47% (0.47) was obtained from the selected parameters. The results showed that for a process such as needle-punching, which is influenced by multiple variables, it is important to also study the interactive effects of process parameters for achieving optimum sound absorption. The second part of the study deals with the effect of type of natural fibre (fineness), and the blending ratio (with PET fibres) on the air permeability of the needle-punched non-woven fabrics and then it proceeds to study the effect of the air-gap, type of natural fibre (fineness) and blending ratio (with PET fibres) on sound absorption of needle-punched non-woven fabrics. These parameters are tested individually and their two way interaction (synergy) effect using ANOVA. The air-gap was varied from 0mm to 25mm with 5mm increments, three natural fibre types were used and all were blended with polyester fibres at three blending ratios for each natural fibre type. The Univariate Tests of Significance shows that all three parameters have a significant effect on sound absorption together with two two-way interactions, with the exception of the Blend Ratio × Air Gap two-way interaction which was not significant. It was found that the sound absorption improves with the increase in the air-gap size up to 15mm after which sound absorption decreased slightly with the further increase in the air-gap up to 25mm

Clinical strains of mycobacterium tuberculosis induce strain-specific patterns of cytokine production, gene expression and pathway changes in pulmonary alveolar epithelial cells.

Doctor of Philosophy in Microbiology. University of KwaZulu-Natal, Durban 2016.The epidemiological success of M. tuberculosis strains, dominant in different geographic regions globally, may be ascribed to a subversion of the host‟s protective immune response. The increasing prevalence of F15/LAM4/KZN, Beijing, F11 and F28 Mycobacterium tuberculosis strain families, coupled with rapidly evolving drug resistance within the KwaZulu-Natal province of South Africa population has resulted in a need to characterize host response associated with infection by these strains. Therefore, in this study, cytokine/chemokine production and host transcriptomics were investigated in A549 pulmonary epithelial cells infected with the F15/LAM4/KZN, Beijing, F28, F11, Unique and H37Rv strains. Cytokines/chemokines were quantified using the Bio-Plex Pro Human Cytokine 27-Plex assay at 0, 24, 48 and 72 hr post-infection. Changes in host gene expression were determined by whole genome RNA Sequencing (RNA-Seq) using the Illumina HiSeq 2000 platform. The 50 bp reads were mapped to the human genome (hg19) using Tophat (2.0.10). Differential expression was quantified using Cufflinks (2.1.0) with false discovery rate (FDR) of 0.05 and a log fold change cutoff of ≥2. R commands (Bioconductor), MeV and Ingenuity Pathway Analysis (IPA) were used to generate heat maps, network and pathways analysis. Twenty-three out of 27 analytes were detected. All strains, except the F28 strain induced an increased production of 18, and a decrease in 5 cytokines/chemokines at 24, 48 and 72 hr post-infection, compared to the uninfected control. Increased production of all 23 analytes by the F28 strain occurred at 48 and 72 hr. Among the 23 cytokines/chemokines that were detected, anti-inflammatory and pro-inflammatory cytokines, as well as chemokines were produced at the different time intervals. Compared to the other strains, high cytokine levels were induced by the F28 strain at 48 hr and F15/LAM4/KZN strain at 72 hr for most analytes. A lower cytokine production was induced by the Beijing and Unique strains at all time intervals. In the case of the laboratory strain H37Rv either a higher or lower cytokine/chemokine production was observed, compared to the clinical strains. RNA-Seq revealed differential gene expression that varied among the strains with respect to both up- and down-regulated genes: F15/LAM4/KZN (1187), Beijing (1252), F11 (1639), F28 (870), Unique (886) and H37Rv (1179). A total of 292 genes were commonly induced by all strains, of which 52 were down-regulated and 240 were up-regulated. Different strain combinations induced different genes that were involved in a variety of pathways, including immune response and apoptosis pathways. Furthermore, strain specific genes were activated by each strain as follows: F15/LAM4/KZN (138), Beijing (52), F11 (255), F28 (55), Unique (185) and H37Rv (125). The F15/LAM4/KZN, Unique and H37Rv were the only strains that had molecular signatures with overlapping functional Kegg and Reactome pathways for their specific genes. IPA analysis revealed canonical pathways that differed among the strains, with the interferon signalling and hepatic fibrosis/hepatic stellate cell activation pathways being among the top 5 pathways in all the strains. Cholesterol biosynthesis and immune related pathway enrichment was similar in the Beijing and Unique strains whilst the F15/LAM4/KZN strain showed closer relatedness to the F11 strain, and the F28 strain closely clustered to the H37Rv strain. The Beijing and Unique strains highly enriched cholesterol biosynthesis pathways compared to other clinical and laboratory H37Rv strain. The top scoring networks induced by these clinical strains varied among the strains with the associated functions. These gene networks were involved in antimicrobial response, developmental disorder, organismal injury, infectious disease and cellular development. Among the transcriptional factors, only EHL, IRF7, PML, STAT1, STAT2 and VDR were induced by all clinical strains, while other factors were strain specific. In conclusion, low cytokine/chemokine production and activation of immune associated pathways by the Beijing and Unique strains suggest a higher virulence for these strains compared to the F15/LAM4/KZN, F11 and F28 strains. These characteristics may explain the high transmissibility and prevalence of the Beijing strains. A similar pattern exhibited by the less prevalent, non-clustering Unique strain, may suggest some virulence attributes in common with the Beijing strain. Findings in this study have the potential to reveal useful biomarkers that can be used as targets for alternative TB therapeutics including immunomodulators that take into consideration network regulations and strain-specific pathways and molecular signatures

Green supply chain management challenges in the South African fast-moving consumer goods industry : a case of Unilever.

Master of Commerce in Supply Chain Management. University of KwaZulu-Natal, Durban 2015.Abstract available in PDF file

The effects of digital and physical service quality on customer loyalty in the South African retail banking industry

Text in EnglishThe researcher aimed to determine the effects of digital and physical service quality on customer loyalty in the South African retail banking industry. To measure the effects of service quality for the physical channel, the researcher used the SERVQUAL model, and the E-S-QUAL model were used to measure the digital channel service quality. A quantitative research approach was employed. Data were gathered using a self administered, structured questionnaire. Constructs were measured using a six-point Likert scale. A convenience sampling method was used for this study. A total of 384 valid responses from both male and female participants aged between 18 to 60 were collected using an online questionnaire. A descriptive and standard multiple regression directed on IBM Statistical Package for Social Sciences (SPSS) was used. This study established that customer loyalty and service quality are positively correlated and that both physical channel service quality and digital service quality influence customer loyalty. However, this study revealed that digital service quality has more impact on customer loyalty than physical channel service quality on customer loyalty. Bank managers are encouraged to find ways to constantly improve service quality, sustain their competitive edge and maintain customer loyalty. Bank managers can do this by creating an omnichannel customer experience. Practical and theoretical implications for the study are also providedM. Com. (Commerce)Marketing and Retai

Examining curriculum change in English language teaching from O-level to the IGCSE curriculum in four selected high schools in Swaziland.

This study was undertaken to explore curriculum change from the General Certificate in Education (GCE) Ordinary Level (O-Level) to the International General Certificate in Secondary Education (lGCSE) with regard to English language teaching in four high schools in the Manzini region of Swaziland. The study investigated teachers' perceptions of the curriculum change and how they implemented it. The impact of the training teachers received in preparation for the introduction of the IGCSE English curriculum was also explored. An interpretive research paradigm using qualitative methodology was chosen for the study and was driven by the following critical research questions: 1. How do teachers experience curriculum change from GCE O-Level to IGCSE with regard to English language teaching? 2. How was this change implemented in the Form 4 English language classrooms? Qualitative methods comprising semi-structured interviews and non-participant classroom observations were used for collecting data. Data from interviews with teachers were analysed thematically through the use of the constant comparison method, while classroom observations data were qualitatively analysed by using themes that emerged from the observation schedule designed for the study. The data from classroom observations were triangulated with data from interviews with teachers to ensure validity of the study. The study used the body of literature that relates to second language acquisition (SLA) and learning, with specific reference to social constructivism, bilingualism, communicative language teaching and task-based language teaching approaches, literacy and the genre approach as the theoretical framework. The theoretical framework facilitated an understanding that knowledge or meaningful learning is constructed by the learners as they interact using the target language. The results revealed that the teachers used a constructivist approach towards teaching which comprised the communicative language teaching and task-based language teaching and learning approaches. The IGCSE curriculum emphasizes the use of these approaches. The findings also indicated that teachers were inadequately prepared for teaching the IGCSE English curriculum as some of the workshop facilitators were less informed than some of the participants; and that they were only given guidance for conducting assessment in the oral skill without training them how to teach it. Also, the language aspects such as grammar, writing and reading were left out when the curriculum was reviewed, as a result teachers reverted to using the structural approach when teaching grammar, as opposed to the constructivist approach. Findings showed that as much as the IGCSE English curriculum was said to be good, the reading skill was inefficiently taught. IGCSE does not give learners quality education since the tasks learners did were cognitively unchallenging. In view of the theoretical framework of the study, the IGCSE English curriculum produces skills-based, vocationally inclined learners who are not geared towards pursuing academic university education. Listening comprehension was found to be the most problematic language aspect since the learners could not understand the English native speakers' accent when they listened to passages from tapes and CD's during examinations. Using the genre approach to essay writing findings showed that teaching essay writing was not well grounded. The study recommended that the curriculum be reviewed and teachers be taught more effective approaches to teaching essay writing as well as reading comprehension. It was also recommended that the Ministry of Education should assist teachers with additional resources and multimedia for teaching listening skills including CDs and listening to talk shows and in teaching essay writing. The study further recommended that localisation of the curriculum to SIGCSE should be postponed until a suitable curriculum is identified and that further research be conducted which would include a larger study that would be a true representation of all high schools in the four regions of the country

Dynamique Socio-Économique de l'adoption des Variétés Améliorées du Manioc en République Démocratique du Congo (RDC) : Cas des Provinces de Kongo Central et la Tshopo

Cassava production is characterized by important contribution of farmers to food security. Dissemination of improved varieties will continue to progress according to socio-economic context. Overall, study aims to analyze adoption process of improved varieties. Specifically, it aims to determine socio-economic factors that influence adoption of these agricultural innovations. The study used object approach, focusing on the number and characteristics of innovations. The survey was conducted using individual questionnaire, administered to 180 farmers equitably distributed between provinces of Kongo Central and Tshopo. Lueki, Antiota, Nsansi and Obama are the most adopted varieties. The average rate of adoption is 74.27 %, on average area of less than one hectare (0.77 ha). Econometric model of Tobit specified variables influencing that adoption. In Kongo Central, it is positively influenced by distance to rural markets, while it is negatively influenced by state of access roads to Matadi City, distance to that City and age. In Tshopo, characteristics of varieties, level of education and distance to Kisangani City, influence positively adoption. In order to professionalize production of cassava, emergence of modern farmers is important, to sow reasonable areas. That emergence could be considerably supported by the strengthening of technical capacities, improvement of market system, improvement of roads and agricultural marketing. La production du manioc, est caractérisée par la contribution importante des paysans à la sécurité alimentaire. La diffusion des variétés améliorées va continuer à progresser suivant le contexte socio-économique. Globalement, l’étude vise à analyser le processus d’adoption des variétés améliorées. Spécifiquement, elle vise à déterminer les facteurs socioéconomiques qui influencent l'adoption de ces innovations agricoles. L’étude a employé l’approche objet, centrée sur le nombre et les caractéristiques des innovations. L'enquête a été conduite à l'aide du questionnaire individuel, administré à 180 paysans équitablement répartis entre les provinces de Kongo Central et la Tshopo. Lueki, Antiota, Nsansi et Obama sont les variétés les plus adoptées. Le taux moyen d'adoption est de 74,27 %, sur une superficie moyenne de moins d’un hectare (0,77 ha). Le modèle économétrique Tobit a spécifié les variables influençant cette adoption. Au Kongo Central, elle est positivement influencée par la distance aux marchés ruraux, tandis qu’elle est négativement influencée par l'état des routes d'accès à la ville de Matadi, la distance à cette ville et l’âge. À la Tshopo, les caractéristiques des variétés, le niveau d'instruction et la distance à la ville de Kisangani, influencent positivement l’adoption. Pour professionnaliser la production du manioc, l’émergence des fermiers modernes s’avère impératif, pour emblaver des superficies raisonnables. Cette émergence pourrait être considérablement appuyée par le renforcement des capacités techniques, l’amélioration du système des marchés, l’amélioration des infrastructures routières et le marketing agricole

Interactions between Type 1 Interferons and the Th17 Response in Tuberculosis: Lessons Learned from Autoimmune Diseases

textabstractThe classical paradigm of tuberculosis (TB) immunity, with a central protective role for Th1 responses and IFN-γ-stimulated cellular responses, has been challenged by unsatisfactory results of vaccine strategies aimed at enhancing Th1 immunity. Moreover, preclinical TB models have shown that increasing IFN-γ responses in the lungs is more damaging to the host than to the pathogen. Type 1 interferon signaling and altered Th17 responses have also been associated with active TB, but their functional roles in TB pathogenesis remain to be established. These two host responses have been studied in more detail in autoimmune diseases (AID) and show functional interactions that are of potential interest in TB immunity. In this review, we first identify the role of type 1 interferons and Th17 immunity in TB, followed by an overview of interactions between these responses observed in systemic AID. We discuss (i) the effects of GM-CSF-secreting Th17.1 cells and type 1 interferons on CCR2+ monocytes; (ii) convergence of IL-17 and type 1 interferon signaling on stimulating B-cell activating factor production and the central role of neutrophils in this process; and (iii) synergy between IL-17 and type 1 interferons in the generation and function of tertiary lymphoid structures and the associated follicular helper T-cell responses. Evaluation of these autoimmune-related pathways in TB pathogenesis provides a new perspective on recent developments in TB research

Dynamique Socio-économique de L’adoption de la Transformation Améliorée de la Farine Fermentée du Manioc en République Démocratique du Congo (RDC)

Cassava processing remains artisanal, often with poor performance on product quality. In a bid to promote it, there need to be a progression in agricultural innovations according to socioeconomic context. This paper, however, focuses on analyzing the adoption process of microchip technology. Specifically, it aims to determinate the socio-economic factors that influence it. A survey was conducted using individual questionnaire, which was administrated to 112 processors in provinces of Kongo Central and Tshopo. In view of the high costs of this agricultural innovation, the dotation approach of processing kits, in favor of farmer’s organizations, was promoted. Services were offered free of charge for members. 57% of the members employ them to produce Fufu (fermented flour). Best quality of final product, ease of producing it, and quick drying of microchip constitute the main motivations. Women were majorly active in the modern post-harvest activity. Despite the fact the services were offered free of charge, unfair competition in the market and logistic costs were the main obstacles according to 43 % of non-adopters. Adoption is positively influenced by external labor and state of access roads to rural and urban markets (Matadi and Kisangani). On the other hand, it is negatively influenced by remoteness to research stations (Gimbi and Yangambi). Emergence of that modern activity will stimulate raw material supply, and it should be significantly supported by socioeconomic factors. These include external labor, roads infrastructures of access to markets (rural and urban), and access to technological information. La transformation du manioc demeure artisanale, avec souvent une faible performance sur la qualité du produit. Pour la promouvoir, la diffusion des innovations agricoles va continuer à progresser suivant le contexte socioéconomique. Globalement, l’étude vise à analyser le processus d’adoption de la technologie des micro-cossettes. Spécifiquement, elle vise à déterminer les facteurs socio-économiques qui l’influencent. L'enquête a été conduite à l'aide du questionnaire individuel, administré à 112 transformateurs répartis dans les provinces de Kongo Central et de la Tshopo. Face aux coûts élevés de cette innovation agricole, l’approche de dotation des kits de transformation, en faveur des Organisations Paysannes, est préconisée. Ainsi, les services sont gratuitement offerts aux membres. Cependant, 57 % d’entre-eux y recourent, pour produire le Fufu (farine fermentée). La meilleure qualité du produit final, la facilité de l’obtenir et le séchage rapide des micro-cossettes sont les principales motivations. La femme est toujours active dans cette activité postrécolte moderne. Malgré cette gratuité des services, la concurrence déloyale sur le marché et les charges logistiques constituent les obstacles, selon 43 % des non-adoptants. L’adoption est positivement influencée par la main d’œuvre externe, l’état des routes d'accès aux marchés ruraux et urbains (Matadi et Kisangani), alors qu’elle est négativement influencée par l’éloignement aux stations de recherche (Gimbi et Yangambi). L’émergence de cette activité moderne, stimulera l’offre en matière première. Elle pourrait être considérablement appuyée par des facteurs socio-économiques. Il s’agit de la main d’œuvre, des infrastructures routières d’accès aux marchés (ruraux et urbains) et l’accès à l’information technologique