52 research outputs found

    A classical approach to the restoration of discipline in South African schools

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    As a result of the era of civil disobedience associated with the struggle for freedom and democracy discipline in many schools has deteriorated. The persistent lack of discipline in all South African schools can only be countered by means of a wise application of discipline. Application of “discipline” according to the standard dictionary meanings of the word will, however, not be appropriate since it implies a clamp-down on disruptive behaviour, including punishment, chastisement and retribution. Discipline associated with the paideia ideal of well-educatedness and of the educator as the servant of his learners (paidagogos), though within the context of a reformational perspective of discipline on the other hand, will be more suitable

    The toxic effects on cardiac myocytes of tyledoside F, a cumulative neurotoxic cardiac glycoside isolated from Tylecodon grandiflorus

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    To investigate the cardiac cellular effects of tyledoside F, a cumulative neurotoxic bufadienolide and ouabain, a non-cumulative cardenolide, the whole-cell clamp method was used to measure the Na-K pump current after the Na-K pump had been activated by high intracellular Na²⁺. The toxic effects of tyledoside F and ouabain on cardiac myocytes were also investigated by observing the effect of the Ca²⁺ overload on the viability of myocytes during a period of 75 min. From the results it is clear that there are similarities in the direct effects of tyledoside F and ouabain on the Na-K pump. It was found that ouabain inhibited the Na-K pump current more than that of tyledoside F. With regard to Ca²⁺ overload, there are differences in their mode of production of Ca²⁺ overload because cinnarizine protects the myocytes against ouabain-induced Ca²⁺ overload but not against tyledoside-induced Ca²⁺ overload. This study shows that with the whole-cell clamp technique tyledoside F inhibited the Na-K pump in a manner similar to inhibition of the pump by ouabain. Viability studies with myocytes indicated that tyledoside F also has other effects which are different from these of ouabain.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.mn201

    A comparison of haemodynamic and vasoconstrictory responses in sheep with a toxic fraction from Pachystigma pygmaeum and with the plant material

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    ST-segment changes in the ECG, which are an indication of acute myocardial ischaemia, are obtained when a small quantity of an extract from dried Pachystigma pygmaeum is injected intravenously in sheep. When the fraction was injected subcutaneously, animals reached a crisis after about 5 h, with low values of stroke volumes and high values for pulmonary arterial pressures, pulmonary vascular resistances and heart rates. The haemodynamic changes are an indication of the development of pump failure of the heart. In sheep, injected subcutaneously with the toxic fraction, as well as for sheep dosed with plant material through rumen fistula, increased serum levels for thromboxane and increased or decreased levels for prostacycline were observed. The experimental results are interpreted as being an indication that these prostaglandines may be involved in the development of gousiekte by impeding cardiopulmonary function as a result of coronary and pulmonary vasoconstriction. The sudden death observed in some gousiekte sheep may be due to myocardial ischaemia and associated arrhythmias.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.mn201

    Cardiotoxicity of the skin of the red-banded rubber frog, Phrynomerus bifasciatus (Smith 1847)

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    The skin of the red-banded rubber frog is said to secrete an unidentified toxin. Whole skin extract as well as HPLC fractions were tested for toxicity on viable, isolated cardiomyocytes. The skin extract and one of its fractions were shown to be cardiotoxic. Whole-cell clamping tests demonstrated that both extract and fraction interfered with the function of the potassium channels of the cardiomyocytes and that the toxic substance has an affinity for the IK₁ channels. Investigations are in progress to isolate and characterize the toxic substance.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.Medical Research Council. PU for CHE.mn201

    Vulnerability of Cape Fold Ecoregion freshwater fishes to climate change and other human impacts

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    1. Native freshwater fish populations throughout South Africa's Cape Fold Ecoregion (CFE) are in decline as a result of human impacts on aquatic habitats, including the introduction of nonnative freshwater fishes. Climate change may be further accelerating declines of many species, although this has not yet been studied in the CFE. This situation presents a major conservation challenge that requires assigning management priorities through assessing species in terms of their vulnerability to climate change. 2. One factor hindering reliable vulnerability assessments and the concurrent development of effective conservation strategies is limited knowledge of the biology and population status of many species. This paper reports on a study employing a rapid assessment method used in the USA, designed to capitalize on available expert knowledge to supplement existing empirical data, to determine the relative vulnerabilities of different species to climate change and other human impacts. Eight local freshwater fish experts conducted vulnerability assessments on 20 native and 17 non‐native freshwater fish species present in the CFE. 3. Results show (1) that native species were generally classified as being more vulnerable to extinction than were non‐native species, (2) that the climate change impacts are expected to increase the vulnerability of most native, and some non‐native, species, (3) that vulnerability hotspots requiring urgent conservation attention occur in the Olifants‐Doring, upper Berg and upper Breede River catchments in the south west of the region, (4) that in addition to providing guidance for prioritizing management interventions, this study highlights the need for reliable data on the biology and distribution of many CFE freshwater fishes, and (5) that identification of priority areas for protection should be based on multiple sources of data

    Biblical Theology of Life in the Old Testament

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    Life is a primary theme in Scripture, expressed in the rich diversity of the various books, corpora and genres of Scripture. Much has been published on what Scripture teaches about life and death. To date, however, no comprehensive biblical theology in which the concept of life is traced throughout the different books and corpora of the Old and New Testament has been published. It is this lacuna that this book aims to fill, assuming that such an approach can provide a valuable contribution to the theological discourse on life and related concepts. The primary aim of this book is to give an indication of the different nuances of the concept of life in the various books and corpora of the Old and New Testament by providing the reader with a book-by-book overview of the concept of life in Scripture. The secondary aim is to give an indication of the overall use and function of the concept of life in the Old Testament, the New Testament, and Scripture as a whole. The latter is provided by using the findings of the book-by-book overview of the concept of life in Scripture to draw the lines together

    Biblical Theology of Life in the Old Testament

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    Life is a primary theme in Scripture, expressed in the rich diversity of the various books, corpora and genres of Scripture. Much has been published on what Scripture teaches about life and death. To date, however, no comprehensive biblical theology in which the concept of life is traced throughout the different books and corpora of the Old and New Testament has been published. It is this lacuna that this book aims to fill, assuming that such an approach can provide a valuable contribution to the theological discourse on life and related concepts. The primary aim of this book is to give an indication of the different nuances of the concept of life in the various books and corpora of the Old and New Testament by providing the reader with a book-by-book overview of the concept of life in Scripture. The secondary aim is to give an indication of the overall use and function of the concept of life in the Old Testament, the New Testament, and Scripture as a whole. The latter is provided by using the findings of the book-by-book overview of the concept of life in Scripture to draw the lines together

    Psoriasis and mental health workshop report : Exploring the links between psychosocial factors, psoriasis, neuroinflammation and cardiovascular disease risk

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    Psoriasis is a systemic, relapsing, inflammatory disease associated with serious comorbidities including mood problems and/or unhealthy lifestyle behaviours. Cutaneous and systemic abnormalities in innate and acquired immunity play a role in its pathogenesis. The exact pathogenetic mechanism remains elusive. Evidence is accumulating that TNF-alpha, IL-17 and IL-23 signalling are highly relevant as targeting these pathways reduces disease activity. Evidence suggests a strong link between psoriasis and depression in adults. The International Psoriasis Council (IPC) held a roundtable event, "Psoriasis and Mental Health", in Barcelona, Spain which focused on the presence of depression and suicidality, plus the role of neuroinflammation in psoriasis, sleep disruption and the impact of depression on cardiovascular disease outcomes. We summarize here the expert presentations to provide additional insight into the understanding of psychiatric comorbidities of psoriasis and of the impact of chronic, systemic inflammation on neuro-and cardiovascular outcomes. the associations between psoriasis and other psychiatric comorbidities are still controversial and warrant further attention

    The state of the Martian climate

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    60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes
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