88 research outputs found

    Teacher training for primary school musical arts education in Botswana : problems and proposals

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    Primary school teacher education in Botswana has undergone a tremendous change in recent years. The former two-year Primary Teaching Certificate has been phased out and replaced by a three-year diploma in primary education. In the three-year teacher training programme, students have the liberty to specialize in two subjects. Since teacher education plays a pivotal role in the efficiency and effectiveness of delivery of the curriculum, it is envisaged that the three-year programme will adequately equip students to ensure efficient and effective syllabi delivery. It is on this premise that this study examined the training of primary school teachers for musical arts education in Botswana’s colleges of primary education. It further identifies the problems in the teacher training programme and proposes ways in which the music training programme could be improved. The research was conducted following a survey method in which data collection techniques of questionnaires, interviews and observations were used. Primary school teachers responded to the questionnaire and some were observed. College lecturers were interviewed. In addition, some important insights were obtained from literature and have been incorporated in this study. Information obtained revealed that students are admitted at the colleges of education with little or no formal music education and this makes it difficult for them to choose music as an area of specialisation. The syllabi that are used for the two music categories do not differ much; there is inadequate allocation of time for music lessons. The syllabi do not cover much African music, concentrating more on Western educationists than on African ones. Colleges of education lack resources for effective training and the emphasis is more on the theoretical aspect than the practical component. The study indicates that teachers are of the opinion that the training they undergo does not adequately equip them to face the challenges of the CAPA (Creative and Performing Arts) syllabus - which deals with practical subjects of which music is one. Consequently, very few activities are employed when teaching the CAPA syllabus at primary schools. Primary schools also lack musical instruments. Teachers are unable to integrate music with other art forms because the training does not include the integration of arts education. These are some of the problems faced by the teacher training as revealed by this study. The research proposes ways in which the admission can be done and the syllabus for musical arts education which can then be used at colleges. There are also recommendations to be considered by the Ministry of Education, music educators and parents, in order to improve musical arts education in Botswana.Dissertation (MMus)--University of Pretoria, 2008.Musicunrestricte

    Comparison of bacterial culture and 16S rRNA community profiling by clonal analysis and pyrosequencing for the characterization of the dentine caries-associated microbiome

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    Culture-independent analyses have greatly expanded knowledge regarding the composition of complex bacterial communities including those associated with oral diseases. A consistent finding from such studies, however, has been the under-reporting of members of the phylum Actinobacteria. In this study, five pairs of broad range primers targeting 16S rRNA genes were used in clonal analysis of 6 samples collected from tooth lesions involving dentine in subjects with active caries. Samples were also subjected to cultural analysis and pyrosequencing by means of the 454 platform. A diverse bacterial community of 229 species-level taxa was revealed by culture and clonal analysis, dominated by representatives of the genera Prevotella, Lactobacillus, Selenomonas, and Streptococcus. The five most abundant species were: Lactobacillus gasseri, Prevotella denticola, Alloprevotella tannerae, S. mutans and Streptococcus sp. HOT 070, which together made up 31.6 % of the sequences. Two samples were dominated by lactobacilli, while the remaining samples had low numbers of lactobacilli but significantly higher numbers of Prevotella species. The different primer pairs produced broadly similar data but proportions of the phylum Bacteroidetes were significantly higher when primer 1387R was used. All of the primer sets underestimated the proportion of Actinobacteria compared to culture. Pyrosequencing analysis of the samples was performed to a depth of sequencing of 4293 sequences per sample which were identified to 264 species-level taxa, and resulted in significantly higher coverage estimates than the clonal analysis. Pyrosequencing, however, also underestimated the relative abundance of Actinobacteria compared to culture

    Identifying Low pH Active and Lactate-Utilizing Taxa within Oral Microbiome Communities from Healthy Children Using Stable Isotope Probing Techniques

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    <div><h3>Background</h3><p>Many human microbial infectious diseases including dental caries are polymicrobial in nature. How these complex multi-species communities evolve from a healthy to a diseased state is not well understood. Although many health- or disease-associated oral bacteria have been characterized <em>in vitro</em>, their physiology within the complex oral microbiome is difficult to determine with current approaches. In addition, about half of these species remain uncultivated to date with little known besides their 16S rRNA sequence. Lacking culture-based physiological analyses, the functional roles of uncultivated species will remain enigmatic despite their apparent disease correlation. To start addressing these knowledge gaps, we applied a combination of Magnetic Resonance Spectroscopy (MRS) with RNA and DNA based Stable Isotope Probing (SIP) to oral plaque communities from healthy children for <em>in vitro</em> temporal monitoring of metabolites and identification of metabolically active and inactive bacterial species.</p> <h3>Methodology/Principal Findings</h3><p>Supragingival plaque samples from caries-free children incubated with <sup>13</sup>C-substrates under imposed healthy (buffered, pH 7) and diseased states (pH 5.5 and pH 4.5) produced lactate as the dominant organic acid from glucose metabolism. Rapid lactate utilization upon glucose depletion was observed under pH 7 conditions. SIP analyses revealed a number of genera containing cultured and uncultivated taxa with metabolic capabilities at pH 5.5. The diversity of active species decreased significantly at pH 4.5 and was dominated by <em>Lactobacillus</em> and <em>Propionibacterium</em> species, both of which have been previously found within carious lesions from children.</p> <h3>Conclusions/Significance</h3><p>Our approach allowed for identification of species that metabolize carbohydrates under different pH conditions and supports the importance of Lactobacilli and Propionibacterium in the development of childhood caries. Identification of species within healthy subjects that are active at low pH can lead to a better understanding of oral caries onset and generate appropriate targets for preventative measures in the early stages.</p> </div

    Pyrosequencing as a tool for better understanding of human microbiomes

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    Next-generation sequencing technologies have revolutionized the analysis of microbial communities in diverse environments, including the human body. This article reviews several aspects of one of these technologies, the pyrosequencing technique, including its principles, applications, and significant contribution to the study of the human microbiome, with especial emphasis on the oral microbiome. The results brought about by pyrosequencing studies have significantly contributed to refining and augmenting the knowledge of the community membership and structure in and on the human body in healthy and diseased conditions. Because most oral infectious diseases are currently regarded as biofilm-related polymicrobial infections, high-throughput sequencing technologies have the potential to disclose specific patterns related to health or disease. Further advances in technology hold the perspective to have important implications in terms of accurate diagnosis and more effective preventive and therapeutic measures for common oral diseases

    Molecular analysis of the oral microbiota of dental diseases

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    Traditionally, bacterial culture has been used for bacterial detection, allowing study of living microorganisms. Molecular methods are rapid and allow simultaneous identification of numerous species and uncultivated phylotypes. The objective of this doctoral thesis was to investigate the role of the oral microbiota, including poorly characterized and uncultivated bacteria, in dental caries and periodontitis, by comprehensive molecular, clinical, and statistical methods. The microbiota of 275 pre-school children (75 with caries and 200 caries-free) was examined by whole genomic DNA probes, 16S rDNA cloning and sequencing, and PCR. Streptococcus mutans, exhibiting a combined association with Streptococcus sobrinus, was significantly associated with Early Childhood Caries (ECC). Plaque from children with Severe Early Childhood Caries (S-ECC) was diverse with 138 identified and 107 unidentified taxa, which possibly included novel phylotypes. Other species/phylotypes associated with childhood caries included Lactobacillus gasseri (p&lt;0.01), Lactobacillus fermentum, Actinomyces israelii, and Actinomyces odontolyticus (all p&lt;0.05, ECC), Veillonella parvula (p&lt;0.01), Veillonella atypica (p&lt;0.05), and Veillonella sp. HOT-780 (p&lt;0.01, S-ECC). Lactobacillus acidophilus and Lactobacillus reuteri, both used as probiotic therapy species, were detected more frequently in caries-free children than those with ECC. Fastidious periodontal species, including Parvimonas micra, Aggregatibacter actinomycetemcomitans, Eubacterium brachy, Filifactor alocis (all p &lt;0.05), and Porphyromonas gingivalis (p&lt;0.01), were also more frequently detected in children with dental caries than in caries-free children. Other variables associated with ECC were race, dental visit, snacking (all p&lt;0.05), and visible dental plaque (p&lt;0.01). The oral microbiota of early periodontitis in young adults (N=141) was analyzed by whole genomic and oligonucleotide DNA probes, and PCR. Species detected more frequently in early periodontitis than periodontal health included Treponema denticola, F. alocis, Porphyromonas endodontalis, Bacteroidetes sp. HOT-274 (oral clone AU126), and A. odontolyticus (p&lt;0.01) by oligonucleotide DNA probes, and P. gingivalis (p&lt;0.001) and T. forsythia (p=0.03) by PCR. Subgingival samples exhibited a higher prevalence of periodontitis-associated species than samples from tongue surface, including A. actinomycetemcomitans, T. denticola, T. forsythia (all p&lt;0.05), and uncultivated TM7, Treponema, and Actinobaculum clones (all p&lt;0.05). P. gingivalis (p&lt;0.01) by PCR was associated with periodontal disease progression. Early periodontitis was associated with older age (p=0.01), male gender (p=0.04), and cigarette smoking (p=0.05). The role of bacterial subgroups in periodontitis was examined by studying the serotypeability of 313 genotyped clinical A. actinomycetemcomitans isolates (189 subjects). A total of 95 strains (30 subjects) remained non-serotypeable, although PCR revealed presence of the serotype- specific genes. The absence of the immunodominant serotype-specific antigen was confirmed by immunoblot assays. No major DNA rearrangement in the studied serotype-specific gene clusters was found. In summary, detection of previously cultured species and uncultivated phylotypes revealed the diversity of the oral microbiota in dental diseases and health already early in life. Bacterial species have insufficiently characterized subgroups that may have attributes to evade the host response. Molecular approaches used in this study enable comprehensive, culture-independent characterization of the oral microbiome that may in the future lead to identification of diagnostic bacterial profiles for dental diseases

    The aging population: demographics and the biology of aging

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    Epidemiologic studies show that 11% of the world's population is over 60 years of age; this is projected to increase, by 2050, to 22% of the population. Oral aging is a current focus of several organizations including the Federation Dentaire Internationale, the World Health Organization and the American and Japanese Dental Associations. In their Tokyo Declaration, the Japanese Association identified the elderly population as one of its main target groups. One of the WHO goals is for each person to retain more than 20 teeth by age 80, despite the fact that the prevalence of periodontal disease is continuously rising as the population is aging. Every species has its own characteristic lifespan, which is determined by its evolutionary history and is modified by multiple diverse factors, including biological mechanisms. In humans, the gradual accumulation of products of cellular metabolism and extensive DNA damage contribute to the aging process. Aging is thought to be associated with a low‐grade inflammatory phenotype in mammals, called ‘inflammaging’, and is the result of autophagic capacity impairing so‐called ‘housekeeping activities’ in the cells, resulting in protein aggregation, mitochondrial dysfunction and oxidative stress. Delayed stem‐cell proliferation, associated with aging, may impact the maintenance and survival of a living being, but excessive proliferation could also result in depleted reserves of stem cells. Studies are needed to address the association of delayed cell proliferation and wound healing with the onset of periodontal diseases and response to treatment. The effects of systemic diseases, medications, psychological effects and decreased interest or ability in performing oral‐hygiene practices are thought to result in periodontal diseases, and ultimately in tooth loss, in aged individuals. Together with an aging population comes a responsibility for ‘healthy’ and ‘successful’ aging. This article describes the changing global demographic profile and the effects of an aging society on the prevalence and incidence of periodontal diseases. We review the definitions of normal and successful aging, the principles of geriatric medicine and the highlights of biological aging at cellular, tissue and systems levels
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