99 research outputs found

    Fiber optic Raman spectroscopy for the evaluation of disease state in Duchenne muscular dystrophy:An assessment using the mdx model and human muscle

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    INTRODUCTION/AIMS: Raman spectroscopy is an emerging technique for the evaluation of muscle disease. In this study we evaluate the ability of in vivo intramuscular Raman spectroscopy to detect the effects of voluntary running in the mdx model of Duchenne muscular dystrophy (DMD). We also compare mdx data with muscle spectra from human DMD patients. METHODS: Thirty 90‐day‐old mdx mice were randomly allocated to an exercised group (48‐hour access to a running wheel) and an unexercised group (n = 15 per group). In vivo Raman spectra were collected from both gastrocnemius muscles and histopathological assessment subsequently performed. Raman data were analyzed using principal component analysis–fed linear discriminant analysis (PCA‐LDA). Exercised and unexercised mdx muscle spectra were compared with human DMD samples using cosine similarity. RESULTS: Exercised mice ran an average of 6.5 km over 48 hours, which induced a significant increase in muscle necrosis (P = .03). PCA‐LDA scores were significantly different between the exercised and unexercised groups (P < .0001) and correlated significantly with distance run (P = .01). Raman spectra from exercised mice more closely resembled human spectra than those from unexercised mice. DISCUSSION: Raman spectroscopy provides a readout of the biochemical alterations in muscle in both the mdx mouse and human DMD muscle

    Resisting the desire for the unambiguous: productive gaps in researcher, teacher and student interpretations of a number story task

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    This article offers reflections on task design in the context of a Grade R (reception year) in-service numeracy project in South Africa. The research explores under what conditions, and for what learning purpose, a task designed by someone else may be recast and how varying given task specifications may support or inhibit learning, as a result of that recasting. This question is situated within a two-pronged task design challenge as to emerging gaps between the task designer’s intentions and teacher’s actions and secondly between the teachers’ intentions and students’ actions. Through analysing two teachers and their respective Grade R students’ interpretations of a worksheet task, provided to teachers in the project, we illuminate the way explicit constraints, in the form of task specifications, can be both enabling and constraining of learning. In so doing we recast this ‘double gap’ as enabling productive learning spaces for teacher educators, teachers and students

    Linguistic challenges faced by rural Tshivenda-speaking teachers when Grade 4 learners transition to English

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    The general complaint of teachers in rural monolingual communities is that teaching becomes problematic after learners are promoted to Grade 4. While the transition to a next academic phase places new cognitive demands on the learners, they must also adjust to being taught in English after 3 years of mother tongue education. This qualitative case study was underpinned by Krashen’s theory of second-language acquisition which emphasises the importance of exposure to and interaction in the target language. Six Grade 4 teachers who are mother tongue speakers of Tshivenda and two curriculum advisors participated in the study. Data were collected through individual interviews and classroom observations. Initially, it was assumed that the transition was problematic, because learners’ English proficiency was inadequate, but teachers too struggled to impart academic content to Grade 4 learners and relied heavily on code switching. This strategy contributed to learners’ understanding of content, but militated against any improvement in their English. The remoteness of this rural monolingual community implies a limited exposure to the target language, but ought not to be reckoned an excuse. Means to build teachers’ linguistic confidence and improve their oral proficiency during initial teacher preparation as well as greater in-service support should ameliorate the transition for learners. A revision of the mother tongue Foundation Phase curriculum and monitored implementation is advisable

    A snapshot of early childhood care and education in South Africa: institutional offerings, challenges and recommendations

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    This article draws from a research report on the Project for Inclusive Early Childhood Care and Education (PIECCE), which surveyed attitudes, training strategies, materials and entrance requirements across most relevant higher education institutions (HEIs), non-governmental organisations (NGOs) and technical and vocational education and training colleges (TVETs). The aim of this study was to identify what institutions were offering in terms of training teachers in the birth-to-four age group, to identify the challenges and provide recommendations based on the findings

    Contextualising school readiness in South Africa: Stakeholders’ perspectives

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    Preparing children for mainstream school occurs in systems that act as an overarching context. The perspectives of stakeholders influence how they prepare children for mainstream education.The aim of this study was to develop an understanding of the contextual factors that affect school readiness as identified by stakeholders. School readiness was conceptualised as a function of contextual influences and connections between individual and systemic factors enabling the child to benefit from the curriculum

    Normal right- and left ventricular volumes and myocardial mass in children measured by steady state free precession cardiovascular magnetic resonance

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    BACKGROUND: Quantification of ventricular volume by steady state free precession (SSFP) cardiovascular magnetic resonance is accurate and reproducible. Normal values exist for adults, but are lacking for children.We sought to establish normal values for left and right ventricular volumes, mass and function in healthy children by using SSFP. METHODS AND RESULTS: Fifty children (27 females, 23 males) without cardiovascular disease were evaluated. Median age was 11 years (range 7 months - 18 years), weight 35 kg (range 7-77 kg), height 146 cm (range 66-181 cm). Thirty-six examinations were performed with breath holding, 14 in freely breathing sedated children.Ventricular volumes and mass were measured in the end systolic and end diastolic phase on SSFP cine images acquired in a short axis plane as a stack of 12 contiguous slices covering full length of both ventricles. Regression analysis showed an exponential relationship between body surface area (BSA) and ventricular volumes and mass (normal value = a*BSAb). Normative curves for males and females are presented in relation to BSA for the end-diastolic volume, end-systolic volume and mass of both ventricles. Intra- and interobserver variability of the measurements was within the limits of 2% and 7% respectively, except for right ventricular mass (10%). CONCLUSION: The exponential equation for calculation of normal values for each ventricular parameter and graphical display of normative curves for data acquired in healthy children by SSFP cardiovascular magnetic resonance are provided

    Mathematical practices and mathematical modes of enquiry: Same or different?

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    Background: In this paper, I share a case study of a teacher’s work on mathematics tasks in the context of a ‘mathematics for teaching’ course aiming to develop mathematical content understandings and mathematical practices among primary teachers in one South African province. The course was developed in a national context of concerns about the nature and levels of primary teachers’ mathematical knowledge. Theories viewing mathematical practices as fundamental, contrasted with those that view mathematical practices and mathematical content in more separate and ‘to be integrated’ ways, are used to frame the analysis and ritically reflect on the findings. Results: Data from this teacher’s pre-test and selected course assessments and interactions suggest that while he was able to develop some aspects of the mathematical practices described in the literature, his overall orientation remained attuned to memorization and recall. Findings also pointed to an ongoing reliance on external validation of the ‘correctness’ of his answers. Conclusions: The data suggest that the presence of elements of mathematical practices cannot be viewed as equivalent to the presence of mathematical modes of enquiry. The analysis presented in this paper suggests that while elements of mathematical practices can be developed, moving towards an encompassing orientation to mathematical modes of enquiry may require more central focus on problem-solving approaches to achieve a change in orientation
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