114 research outputs found

    The challenges experienced by educators in primary schools regarding continuous professional development

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    The transition from apartheid to democracy in South Africa, which began in 1994 led to a change in a plethora of policies and/or legislation. In recent years there has been much debate on how the standard of education provisioning in schools could be raised in the light of the introduction of the much debated Revised National Curriculum Statement (RNCS) and thereafter the National Curriculum Statement (NCS). These reform initiatives have brought about confusion and a sense of unsettledness amongst educators, including principals as well as their School Management Teams. Furthermore, the abovementioned and other policies required educators to acquaint themselves with either the materials that are used or the content of the curriculum and the planning and presentation of lessons. This entails in some occasions that educators who are more experienced have to assist the less experienced ones since they understand the RNCS and more recently the NCS better than the others. According to me this emphasises the importance of educator development towards raising the standards in schools. Continuous Professional Development (CPD) is a process that fits the role of an educator as a lifelong learner. The aforementioned is captured in the Norms and Standards for Educators (2000). The need for more attention to be accorded to the professional development of practising educators is emphasised in the Report of the Ministerial Committee on Teacher Education (2005). This report led to the development of the National Policy Framework for Teacher Education and Development which has as its aim to attempt to address the need for suitably qualified educators in South Africa. The National Policy Framework for Teacher Education and Development will be used in this study along with the Integrated Quality Management Systems (IQMS) as tools to achieve the continuous development of educators in South African schools. The Personnel Administration Measures (PAM) of 1999 are also used since they stipulate the roles and responsibilities of the educator, including those of the principal, deputy principal(s) as well as the heads of department. In particular it stipulates that the principal (Department of Education, 1999:10) is responsible for the development of staff training programmes, school-based, school-focused and externally directed, and to assist educators, particularly new and inexperienced educators, in developing and achieving educational objectives in accordance with the needs of the school. This research project deals with the challenges experienced by educators regarding their own Continued Professional Development (CPD). It thus aims at coming up with an empirical account of the challenges experienced by the said educators. The study will focus on, among others, the educatorsā€™ experiences in the implementation of the IQMS as a developmental tool for educators in schools. It looks at the roles that different staff members in senior positions in terms of the CPD of the educators. These include the developmental opportunities available in the sampled schools. Carefully selected and drafted interview questions assisted me in soliciting answers from the sampled educators.Dissertation (MEd)--University of Pretoria, 2010.Education Management and Policy Studiesunrestricte

    Metabolomics of the interaction between PPAR-Ī± and age in the PPAR-Ī±-null mouse

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    Regulation between the fed and fasted states in mammals is partially controlled by peroxisome proliferator-activated receptor-Ī± (PPAR-Ī±). Expression of the receptor is high in the liver, heart and skeletal muscle, but decreases with age. A combined 1H nuclear magnetic resonance (NMR) spectroscopy and gas chromatography-mass spectrometry metabolomic approach has been used to examine metabolism in the liver, heart, skeletal muscle and adipose tissue in PPAR-Ī±-null mice and wild-type controls during ageing between 3 and 13 months. For the PPAR-Ī±-null mouse, multivariate statistics highlighted hepatic steatosis, reductions in the concentrations of glucose and glycogen in both the liver and muscle tissue, and profound changes in lipid metabolism in each tissue, reflecting known expression targets of the PPAR-Ī± receptor. Hepatic glycogen and glucose also decreased with age for both genotypes. These findings indicate the development of age-related hepatic steatosis in the PPAR-Ī±-null mouse, with the normal metabolic changes associated with ageing exacerbating changes associated with genotype. Furthermore, the combined metabolomic and multivariate statistics approach provides a robust method for examining the interaction between age and genotype

    NEIL1 excises 3ā€² end proximal oxidative DNA lesions resistant to cleavage by NTH1 and OGG1

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    Base excision repair is the major pathway for the repair of oxidative DNA damage in human cells that is initiated by a damage-specific DNA glycosylase. In human cells, the major DNA glycosylases for the excision of oxidative base damage are OGG1 and NTH1 that excise 8-oxoguanine and oxidative pyrimidines, respectively. We find that both enzymes have limited activity on DNA lesions located in the vicinity of the 3ā€² end of a DNA single-strand break, suggesting that other enzymes are involved in the processing of such lesions. In this study, we identify and characterize NEIL1 as a major DNA glycosylase that excises oxidative base damage located in close proximity to the 3ā€² end of a DNA single-strand break

    Processing of thymine glycol in a clustered DNA damage site: mutagenic or cytotoxic

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    Localized clustering of damage is a hallmark of certain DNA-damaging agents, particularly ionizing radiation. The potential for genetic change arising from the effects of clustered damage sites containing combinations of AP sites, 8-oxo-7,8-dihydroguanine (8-oxoG) or 5,6-dihydrothymine is high. To date clusters containing a DNA base lesion that is a strong block to replicative polymerases, have not been explored. Since thymine glycol (Tg) is non-mutagenic but a strong block to replicative polymerases, we have investigated whether clusters containing Tg are highly mutagenic or lead to potentially cytotoxic lesions, when closely opposed to either 8-oxoG or an AP site. Using a bacterial plasmid-based assay and repair assays using cell extracts or purified proteins, we have shown that DNA double-strand breaks (DSBs) arise when Tg is opposite to an AP site, either through attempted base excision repair or at replication. In contrast, 8-oxoG opposite to Tg in a cluster ā€˜protectsā€™ against DSB formation but does enhance the mutation frequency at the site of 8-oxoG relative to that at a single 8-oxoG, due to the decisive role of endonucleases in the initial stages of processing Tg/8-oxoG clusters, removing Tg to give an intermediate with an abasic site or single-strand break

    Media and information literate citizens: think critically, click wisely!

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    Can we improve our societies by clicking wisely? Content providers such as libraries, archives, museums, media and digital communications companies can enable inclusive and sustainable development. However, they do not always live up to these ideals, which creates challenges for the users of these services. Content providers of all types open up new opportunities for lifelong learning. But at the same time, they open up challenges such as misinformation and disinformation, hate speech, and infringement of online privacy, among others. Media and information literacy is a set of competencies that help people to maximize advantages and minimize harms. Media and information literacy covers competencies that enable people to critically and effectively engage with: communications content; the institutions that facilitate this content; and the use of digital technologies. Capacities in these areas are indispensable for all citizens regardless of their ages or backgrounds. This pioneering curriculum presents a comprehensive competency framework of media and information literacy and offers educators and learners structured pedagogical suggestions. It features various detailed modules covering the range of competencies needed to navigate todayā€™s communications ecosystem. This resource links media and information literacy to emerging issues, such as artificial intelligence, digital citizenship education, education for sustainable development, cultural literacy and the exponential rise in misinformation and disinformation. With effective use of this media and information literacy curriculum, everyone can become media and information literate as well as peer-educators of media and information literacy

    Gene and metabolite expression dependence on body mass index in human myocardium

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    Funding Van Geest Foundation, Leicester NIHR Biomedical Research Centre, British Heart Foundation CH/12/1/29419, AA18/3/34220. Competing interests Mrs. Kumar, Prof. Murphy and Dr WoÅŗniak received a grant from Zimmer Biomet. Dr Murphy also received grants from Terumo and Baxter. The remaining authors have disclosed that they do not have any potential conflicts of interest.Peer reviewedPublisher PD

    End-bridging is required for pol Ī¼ to efficiently promote repair of noncomplementary ends by nonhomologous end joining

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    DNA polymerase Ī¼ is a member of the mammalian pol X family and reduces deletion during chromosome break repair by nonhomologous end joining (NHEJ). This biological role is linked to pol Ī¼'s ability to promote NHEJ of ends with noncomplementary 3ā€² overhangs, but questions remain regarding how it performs this role. We show here that synthesis by pol Ī¼ in this context is often rapid and, despite the absence of primer/template base-pairing, instructed by template. However, pol Ī¼ is both much less active and more prone to possible template independence in some contexts, including ends with overhangs longer than two nucleotides. Reduced activity on longer overhangs implies pol Ī¼ is less able to synthesize across longer gaps, arguing pol Ī¼ must bridge both sides of gaps between noncomplementary ends to be effective in NHEJ. Consistent with this argument, a pol Ī¼ mutant defective specifically on gapped substrates is also less active during NHEJ of noncomplementary ends both in vitro and in cells. Taken together, pol Ī¼ activity during NHEJ of noncomplementary ends can thus be primarily linked to pol Ī¼'s ability to work together with core NHEJ factors to bridge DNA ends and perform a template-dependent gap fill-in reaction

    Novel ketone diet enhances physical and cognitive performance.

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    Ketone bodies are the most energy-efficient fuel and yield more ATP per mole of substrate than pyruvate and increase the free energy released from ATP hydrolysis. Elevation of circulating ketones via high-fat, low-carbohydrate diets has been used for the treatment of drug-refractory epilepsy and for neurodegenerative diseases, such as Parkinson's disease. Ketones may also be beneficial for muscle and brain in times of stress, such as endurance exercise. The challenge has been to raise circulating ketone levels by using a palatable diet without altering lipid levels. We found that blood ketone levels can be increased and cholesterol and triglycerides decreased by feeding rats a novel ketone ester diet: chow that is supplemented with (R)-3-hydroxybutyl (R)-3-hydroxybutyrate as 30% of calories. For 5 d, rats on the ketone diet ran 32% further on a treadmill than did control rats that ate an isocaloric diet that was supplemented with either corn starch or palm oil (P < 0.05). Ketone-fed rats completed an 8-arm radial maze test 38% faster than did those on the other diets, making more correct decisions before making a mistake (P < 0.05). Isolated, perfused hearts from rats that were fed the ketone diet had greater free energy available from ATP hydrolysis during increased work than did hearts from rats on the other diets as shown by using [31P]-NMR spectroscopy. The novel ketone diet, therefore, improved physical performance and cognitive function in rats, and its energy-sparing properties suggest that it may help to treat a range of human conditions with metabolic abnormalities.-Murray, A. J., Knight, N. S., Cole, M. A., Cochlin, L. E., Carter, E., Tchabanenko, K., Pichulik, T., Gulston, M. K., Atherton, H. J., Schroeder, M. A., Deacon, R. M. J., Kashiwaya, Y., King, M. T., Pawlosky, R., Rawlins, J. N. P., Tyler, D. J., Griffin, J. L., Robertson, J., Veech, R. L., Clarke, K. Novel ketone diet enhances physical and cognitive performance.A.J.M. thanks the Research Councils UK for supporting his Academic Fellowship. This work was supported by the Defense Advanced Research Projects Agency.This is the final version of the article. It first appeared from FASEB at https://doi.org/10.1096/fj.201600773R

    Cellular responses to DNA double-strand breaks after low-dose Ī³-irradiation

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    DNA double-strand breaks (DSBs) are a serious threat to genome stability and cell viability. Although biological effects of low levels of radiation are not clear, the risks of low-dose radiation are of societal importance. Here, we directly monitored induction and repair of single DSBs and quantitatively analyzed the dynamics of interaction of DNA repair proteins at individual DSB sites in living cells using 53BP1 fused to yellow fluorescent protein (YFP-53BP1) as a surrogate marker. The number of DSBs formed was linear with dose from 5 mGy to 1 Gy. The DSBs induced by very low radiation doses (5 mGy) were repaired with efficiency similar to repair of DSBs induced at higher doses. The YFP-53BP1 foci are dynamic structures: 53BP1 rapidly and reversibly interacted at these DSB sites. The time frame of recruitment and affinity of 53BP1 for DSB sites were indistinguishable between low and high doses, providing mechanistic evidence for the similar DSB repair after low- and high-dose radiation. These findings have important implications for estimating the risk associated with low-dose radiation exposure on human health

    Post-irradiation chemical processing of DNA damage generates double-strand breaks in cells already engaged in repair

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    In cells exposed to ionizing radiation (IR), double-strand breaks (DSBs) form within clustered-damage sites from lesions disrupting the DNA sugarā€“phosphate backbone. It is commonly assumed that these DSBs form promptly and are immediately detected and processed by the cellular DNA damage response (DDR) apparatus. This assumption is questioned by the observation that after irradiation of naked DNA, a fraction of DSBs forms minutes to hours after exposure as a result of temperature dependent, chemical processing of labile sugar lesions. Excess DSBs also form when IR-exposed cells are processed at 50Ā°C, but have been hitherto considered method-related artifact. Thus, it remains unknown whether DSBs actually develop in cells after IR exposure from chemically labile damage. Here, we show that irradiation of ā€˜nakedā€™ or chromatin-organized mammalian DNA produces lesions, which evolve to DSBs and add to those promptly induced, after 8ā€“24ā€‰h in vitro incubation at 37Ā°C or 50Ā°C. The conversion is more efficient in chromatin-associated DNA, completed within 1ā€‰h in cells and delayed in a reducing environment. We conclude that IR generates sugar lesions within clustered-damage sites contributing to DSB formation only after chemical processing, which occurs efficiently at 37Ā°C. This subset of delayed DSBs may challenge DDR, may affect the perceived repair kinetics and requires further characterization
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