57 research outputs found

    The LION instrument on SOHO and its scientific objectives

    Get PDF

    Preparing isiXhosa home language teachers for the 21st century classroom: Student teachers' experiences, challenges and reflections

    Get PDF
    The aim of the article is to identify the gaps between theory and practice in pre-service teacher training with special reference to the teaching of isiXhosa as a home language in the Further Education and Training (FET) phase (Grades 10–12) in some Western Cape high schools. The article is based on data that was collected from Postgraduate Certificate in Education (PGCE) students taking isiXhosa (home language) as one of their teaching method subjects as part of their pre-service training. The data were collected by means of an open-ended questionnaire, semi-structured interviews and an analysis of student teachers’ reflective journals. The article provides an analysis of PGCE students’ experiences and reflections on the teaching of isiXhosa as a home language in schools. It argues that if there is a gap between theory underpinning initial pre-service training and actual practice in schools, there will be no significant improvement in the teaching of isiXhosa as a home language. It concludes by proposing ways of improving both pre-service and in-service teacher education practice to develop African languages as academic or intellectual languages at school level

    Raman spectroscopy - An innovative and versatile tool to follow the respirational activity and carbonate biomineralization of important cave bacteria

    No full text
    Raman gas spectrometry is introduced as a unique tool for the investigation of the respiratory activity that is indicative for growth of bacteria involved in biomineralization. Growth of these bacteria cannot be monitored using conventional turbidity-based optical density measurements due to concomitant mineral formation in the medium. The respiratory activity of carbonate-precipitating Arthrobacter sulfonivorans, isolated from the recently discovered Herrenberg Cave, was investigated during its lifecycle by means of innovative cavity-enhanced Raman gas analysis. This method allowed rapid and nonconsumptive online quantification of CO2 and O2 in situ in the headspace of the bacterial culture. Carbon dioxide production rates of A. sulfonivorans showed two maxima due to its pleomorphic growth lifecycle. In contrast, only one maximum was observed in control organism Pseudomonas fluorescens with a one-stage lifecycle. Further insight into the biomineralization process over time was provided by a combination of Raman macro- and microspectroscopy. With the help of this spatially resolved chemical imaging of the different types of calcium carbonate minerals, it was elucidated that the surface of the A. sulfonivorans bacterial cells served as nuclei for biomineralization of initially spherical vaterite precipitates. These vaterite biominerals continued growing as chemically stable rock-forming calcite crystals with rough edges. Thus, the utilization of innovative Raman multigas spectroscopy, combined with Raman mineral analysis, provided novel insights into microbial-mediated biomineralization and, therefore, provides a powerful methodology in the field of environmental sciences

    The LION instrument on SOHO and its scientific objectives, Ann

    No full text
    Abstract. A technical description is presented of the lowenergy ion and electron (LION) instrument on the SOHO spacecraft and its scientific goals are discussed. LION forms part of the comprehensive suprathermal and energetic particle analyzer (COSTEP), which is, in turn, a subset of the COSTEP/ERNE particle analyser collaboration (CEPAC).
    corecore