Three forms of mathematics education at school level are distinguished: direct expository teaching with an emphasis on procedures, with the expectation that learners will at some later stage make logical and functional sense of what they have learnt and practised (the prevalent form), mathematically rigorous teaching in terms of fundamental mathematical concepts, as in the so-called “modern mathematics” programmes of the sixties, teaching and learning in the context of engaging with meaningful problems and focused both on learning to become good problem solvers (teaching for problem solving) andutilising problems as vehicles for the development of mathematical knowledge andproficiency by learners (problem-centred learning), in conjunction with substantialteacher-led social interaction and mathematical discourse in classrooms. Direct expository teaching of mathematical procedures dominated in school systems after World War II, and was augmented by the “modern mathematics” movement in the period 1960-1970. The latter was experienced as a major failure, and was soon abandoned. Persistent poor outcomes of direct expository procedural teaching of mathematics for the majority of learners, as are still being experienced in South Africa, triggered a world-wide movement promoting teaching mathematics for and via problem solving in the seventies and eighties of the previous century. This movement took the form of a variety of curriculum experiments in which problem solving was the dominant classroom activity, mainly in the USA, Netherlands, France and South Africa. While initially focusing on basic arithmetic (computation with whole numbers) and elementary calculus, the problem-solving movement started to address other mathematical topics (for example, elementary statistics, algebra, differential equations) around the turn of the century. The movement also spread rapidly to other countries, including Japan, Singapore and Australia. Parallel with the problem-solving movement, over the last twenty years, mathematics educators around the world started increasingly to appreciate the role of social interaction and mathematical discourse in classrooms, and to take into consideration the infl uence of the social, socio-mathematical and mathematical norms established in classrooms. This shift away from an emphasis on individualised instruction towards classroom practices characterised by rich and focused social interaction orchestrated by the teacher, became the second element, next to problem-solving, of what is now known as the “reform agenda”. Learning and teaching by means of problem-solving in a socially-interactive classroom, with a strong demand for conceptual understanding, is radically different from traditional expository teaching. However, contrary to commonly-held misunderstandings, it requires substantial teacher involvement. It also requires teachers to assume a much higher level of responsibility for the extent and quality of learning tha
{"title":"Learning via problem solving in mathematics education","authors":"Pieter G. Human","doi":"10.4102/SATNT.V28I4.68","DOIUrl":"https://doi.org/10.4102/SATNT.V28I4.68","url":null,"abstract":"Three forms of mathematics education at school level are distinguished: direct expository teaching with an emphasis on procedures, with the expectation that learners will at some\u0000 later stage make logical and functional sense of what they have learnt and practised (the prevalent form), mathematically rigorous teaching in terms of fundamental mathematical concepts, as in the so-called “modern\u0000 mathematics” programmes of the sixties, teaching and learning in the context of engaging with meaningful problems and focused both on learning to become good problem solvers (teaching for problem solving) andutilising\u0000 problems as vehicles for the development of mathematical knowledge andproficiency by learners (problem-centred learning), in conjunction with substantialteacher-led social interaction and mathematical discourse in\u0000 classrooms. Direct expository teaching of mathematical procedures dominated in school systems after World War II, and was augmented by the “modern mathematics” movement in the period 1960-1970. The latter was\u0000 experienced as a major failure, and was soon abandoned. Persistent poor outcomes of direct expository procedural teaching of mathematics for the majority of learners, as are still being experienced in South Africa, triggered a world-wide movement\u0000 promoting teaching mathematics for and via problem solving in the seventies and eighties of the previous century. This movement took the form of a variety of curriculum experiments in which problem solving was the dominant classroom activity,\u0000 mainly in the USA, Netherlands, France and South Africa. While initially focusing on basic arithmetic (computation with whole numbers) and elementary calculus, the problem-solving movement started to address other mathematical topics (for\u0000 example, elementary statistics, algebra, differential equations) around the turn of the century. The movement also spread rapidly to other countries, including Japan, Singapore and Australia. Parallel with the problem-solving movement, over the\u0000 last twenty years, mathematics educators around the world started increasingly to appreciate the role of social interaction and mathematical discourse in classrooms, and to take into consideration the infl uence of the social, socio-mathematical\u0000 and mathematical norms established in classrooms. This shift away from an emphasis on individualised instruction towards classroom practices characterised by rich and focused social interaction orchestrated by the teacher, became the second\u0000 element, next to problem-solving, of what is now known as the “reform agenda”. Learning and teaching by means of problem-solving in a socially-interactive classroom, with a strong demand for conceptual understanding, is radically different from\u0000 traditional expository teaching. However, contrary to commonly-held misunderstandings, it requires substantial teacher involvement. It also requires teachers to assume a much higher level of responsibility for the extent and quality of learning\u0000 tha","PeriodicalId":30428,"journal":{"name":"South African Journal of Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2009-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70513902","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Whatever the reason, underachievement in mathematics in South Africa is endemic and tantamount to a national disaster. Despite the transformation of education in South Africa, failure rates in mathematics at school and university remain unacceptably high, and the number of learners who leave Grade 12 with a pass mark in both mathematics and physical science is unacceptably low. Relatively little has been written about inadequate performance of Grade 4 to 7 learners in mathematics in South Africa, and even less about possible solutions to the problem. South African primary school learners’ lack of basic mathematics and vocabulary skills in particular is a source of major concern. In the first national systemic evaluation of learners’ skills in English, mathematics and science in 2001 Grade 3 learners achieved an average of 30% in mathematics. In the follow-up studies, Grade 6 learners achieved a national average of 27% in mathematices, in 2004, while nationally eighty percent of Grade 3 and 6 learners achieved less than 50 percent for mathematics and Languages in 2008. The finding that so many primary school learners today are not numerate or literate has a direct influence both on the teaching and the learning of mathematics. Everything possible needs to be done to change this situation. During the past 15 years, the research focus in mathematics has shifted to an examination of the influence of social, cognitive and metacognitive, conative and affective factors on achievement in mathematics. In this regard, it is of particular importance that an ongoing investigation into “other” aspects that impact on achievement in mathematics is launched, rather than to restrict the investigation to mere assessment of objectives that are aimed at continually evaluating cognitive progress in mathematics. There is sufficient empirical evidence that an adequate orientation to the study of mathematics correlates positively with high achievement in mathematics on secondary and tertiary levels. The aim of this research was to investigate the extent to which the performance in study orientation (Study Orientation questionnaire in Mathematics (Primary)) and knowledge of basic vocabulary/terminology in mathematics (Mathematics Vocabulary (Primary)) (vocabulary as one aspect of language in Mathematics) of Grade 4 to 7 learners predict performance in mathematics (Basic Mathematics (Primary)). Three standardised questionnaires were administered, namely the Study Orientation questionnaire in Mathematics (Primary), or SOM(P), Mathematics Vocabulary (Primary) or (MV(P), and Basic Mathematics (Primary) or BM(P). The participants consisted of learners in Grade 4 to 7 (n = 1 103) in North-West Province with respectively Afrikaans, English and Tswana as their home language. Results from the data, by calculating intercorrelations and stepwise regression, confirmed that learners’ performance in mathematics (BM(P)) can be predicted through their performance in the knowledge
{"title":"Study orientation and knowledge of basic vocabulary in Mathematics in the primary school","authors":"M. V. D. Walt","doi":"10.4102/SATNT.V28I4.73","DOIUrl":"https://doi.org/10.4102/SATNT.V28I4.73","url":null,"abstract":"Whatever the reason, underachievement in mathematics in South Africa is endemic and tantamount to a national disaster. Despite the transformation of education in South Africa, failure rates in mathematics at\u0000 school and university remain unacceptably high, and the number of learners who leave Grade 12 with a pass mark in both mathematics and physical science is unacceptably low. Relatively little has been written about inadequate performance of Grade\u0000 4 to 7 learners in mathematics in South Africa, and even less about possible solutions to the problem. South African primary school learners’ lack of basic mathematics and vocabulary skills in particular is a source of major concern. In the first\u0000 national systemic evaluation of learners’ skills in English, mathematics and science in 2001 Grade 3 learners achieved an average of 30% in mathematics. In the follow-up studies, Grade 6 learners achieved a national average of 27% in\u0000 mathematices, in 2004, while nationally eighty percent of Grade 3 and 6 learners achieved less than 50 percent for mathematics and Languages in 2008. The finding that so many primary school learners today are not numerate or literate has a direct\u0000 influence both on the teaching and the learning of mathematics. Everything possible needs to be done to change this situation. During the past 15 years, the research focus in mathematics has shifted to an examination of the influence of social,\u0000 cognitive and metacognitive, conative and affective factors on achievement in mathematics. In this regard, it is of particular importance that an ongoing investigation into “other” aspects that impact on achievement in mathematics is launched,\u0000 rather than to restrict the investigation to mere assessment of objectives that are aimed at continually evaluating cognitive progress in mathematics. There is sufficient empirical evidence that an adequate orientation to the study of mathematics\u0000 correlates positively with high achievement in mathematics on secondary and tertiary levels. The aim of this research was to investigate the extent to which the performance in study orientation (Study Orientation questionnaire in Mathematics\u0000 (Primary)) and knowledge of basic vocabulary/terminology in mathematics (Mathematics Vocabulary (Primary)) (vocabulary as one aspect of language in Mathematics) of Grade 4 to 7 learners predict performance in mathematics (Basic Mathematics\u0000 (Primary)). Three standardised questionnaires were administered, namely the Study Orientation questionnaire in Mathematics (Primary), or SOM(P), Mathematics Vocabulary (Primary) or (MV(P), and Basic Mathematics (Primary) or BM(P). The\u0000 participants consisted of learners in Grade 4 to 7 (n = 1 103) in North-West Province with respectively Afrikaans, English and Tswana as their home language. Results from the data, by calculating intercorrelations and stepwise regression,\u0000 confirmed that learners’ performance in mathematics (BM(P)) can be predicted through their performance in the knowledge ","PeriodicalId":30428,"journal":{"name":"South African Journal of Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2009-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70514048","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper attempts to define a general framework for computability on an arbitrary topological space X . The elements of X are taken as primitives in this approach—also for the coding of functions — and, except when X = N, the natural numbers are not used directly.
{"title":"Elementary topology and universal computation","authors":"P. Potgieter","doi":"10.4102/SATNT.V27I4.97","DOIUrl":"https://doi.org/10.4102/SATNT.V27I4.97","url":null,"abstract":"This paper attempts to define a general framework for computability on an arbitrary topological space X . The elements of X are taken as primitives in this approach—also for the coding of functions — and, except when X =\u0000 N, the natural numbers are not used directly.","PeriodicalId":30428,"journal":{"name":"South African Journal of Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70513688","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In spite of an array of effective antibiotics, tuberculosis is still very common in developing countries where overcrowding, malnutrition and poor hygienic conditions prevail. Over the past 30 years associated HIV infection has worsened the situation by increasing the infection rate and mortality of tuberculosis. Of those diseases caused by a single organism only HIV causes more deaths internationally than tuberculosis. The tubercle bacillus probably first infected man in Neolithic times, and then via infected cattle, but the causative Mycobacteriacea have been in existence for 300 million years. Droplet infection is the most common way of acquiring tuberculosis, although ingestion (e.g. of infected cows’ milk) may occur. Tuberculosis probably originated in Africa. The earliest path gnomonic evidence of human tuberculosis in man was found in osteo-archaeological findings of bone tuberculosis (Pott’s disease of the spine) in the skeleton of anEgyptian priest from the 21st Dynasty (approximately 1 000 BC). Suggestive but not conclusiveevidence of tuberculotic lesions had been found in even earlier skeletons from Egypt and Europe. Medical hieroglyphics from ancient Egypt are silent on the disease, which could be tuberculosis,as do early Indian and Chinese writings. The Old Testament refers to the disease schachapeth, translated as phthisis in the Greek Septuagint. Although the Bible is not specific about this condition, tuberculosis is still called schachapeth in modern Hebrew. In pre-Hippocratic Greece Homer did not mention phthisis, a word meaning non-specific wasting of the body. However. Alexander of Tralles (6th century BC) seemed to narrow the concept down to a specific disease, and in the Hippocratic Corpus (5th-4th centuries BC) phthisis can be recognised as tuberculosis. It was predominantly a respiratory disease commonly seen and considered to be caused by an imbalance of bodily humours. It was commonest in autumn, winter and spring, tended to affect groups of people living close together, and young people in particular. Pregnancy exacerbated phthisis which was characterised by a chronic cough (worse at night), prominent sputum, often blood streaked and presumably arising from necrotic lung tissue. The face was typically flushed with sunken cheeks, sharp nose and very bright eyes. There was atrophy of all muscles with prominent (“winged”) shoulder blades, fever and perspiration often associated with shivering. Symptoms were described which would fit in with complicating lung abscess and empyema. Hippocrates also mentions disease entities which would fit in with extra-pulmonary tuberculosis, like Pott’s disease of the spine and cervical lymphadenopathy (scrofula), although he did not associate this with phthisis. Minimal specific therapy was prescribed. Subsequent writers in the Hellenistic and Roman eras added little to the classic Hippocratic clinical picture of phthisis, but Celsus (1st century AD) and Galen (2nd century) fir
{"title":"Tuberculosis in ancient times","authors":"L. Cilliers, F. Retief","doi":"10.4102/satnt.v27i4.93","DOIUrl":"https://doi.org/10.4102/satnt.v27i4.93","url":null,"abstract":"In spite of an array of effective antibiotics, tuberculosis is still very common in developing countries where overcrowding, malnutrition and poor hygienic conditions prevail. Over the past 30 years associated\u0000 HIV infection has worsened the situation by increasing the infection rate and mortality of tuberculosis. Of those diseases caused by a single organism only HIV causes more deaths internationally than tuberculosis. The tubercle bacillus probably\u0000 first infected man in Neolithic times, and then via infected cattle, but the causative Mycobacteriacea have been in existence for 300 million years. Droplet infection is the most common way of acquiring tuberculosis, although ingestion (e.g. of\u0000 infected cows’ milk) may occur. Tuberculosis probably originated in Africa. The earliest path gnomonic evidence of human tuberculosis in man was found in osteo-archaeological findings of bone tuberculosis (Pott’s disease of the spine) in the\u0000 skeleton of anEgyptian priest from the 21st Dynasty (approximately 1 000 BC). Suggestive but not conclusiveevidence of tuberculotic lesions had been found in even earlier skeletons from Egypt and Europe. Medical hieroglyphics from ancient Egypt\u0000 are silent on the disease, which could be tuberculosis,as do early Indian and Chinese writings. The Old Testament refers to the disease schachapeth, translated as phthisis in the Greek Septuagint. Although the Bible is not specific about this\u0000 condition, tuberculosis is still called schachapeth in modern Hebrew. In pre-Hippocratic Greece Homer did not mention phthisis, a word meaning non-specific wasting of the body. However. Alexander of Tralles (6th century BC) seemed to narrow the\u0000 concept down to a specific disease, and in the Hippocratic Corpus (5th-4th centuries BC) phthisis can be recognised as tuberculosis. It was predominantly a respiratory disease commonly seen and considered to be caused by an imbalance of bodily\u0000 humours. It was commonest in autumn, winter and spring, tended to affect groups of people living close together, and young people in particular. Pregnancy exacerbated phthisis which was characterised by a chronic cough (worse at night), prominent\u0000 sputum, often blood streaked and presumably arising from necrotic lung tissue. The face was typically flushed with sunken cheeks, sharp nose and very bright eyes. There was atrophy of all muscles with prominent (“winged”) shoulder blades, fever\u0000 and perspiration often associated with shivering. Symptoms were described which would fit in with complicating lung abscess and empyema. Hippocrates also mentions disease entities which would fit in with extra-pulmonary tuberculosis, like Pott’s\u0000 disease of the spine and cervical lymphadenopathy (scrofula), although he did not associate this with phthisis. Minimal specific therapy was prescribed. Subsequent writers in the Hellenistic and Roman eras added little to the classic Hippocratic\u0000 clinical picture of phthisis, but Celsus (1st century AD) and Galen (2nd century) fir","PeriodicalId":30428,"journal":{"name":"South African Journal of Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70513621","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The commercial transportation of crude oil and petroleum products by pipeline is receiving increased attention in South Africa. Transnet Pipeline Transport has recently obtained permission from the National Energy Regulator of South Africa (Nersa) to construct and operate a new petroleum products pipeline of 60 cm diameter from Durban to Gauteng. At an operating speed of 10 km/h the proposed 60 cm Transnet pipeline would be able to deliver 3,54 million litres of petroleum product per hour. This is equivalent to 89 deliveries per hour using road tank vehicles with an average carrying capacity of 40 000 litres of fuel per vehicle. This pipeline throughput is also equivalent to two trains departing per hour, each consisting of 42 petroleum tank wagons with an average carrying capacity of 42 500 litres of fuel per wagon. Considering that such road trucks and rail wagons return empty to the upstream refineries in Durban, it is clear that there is no tenable long-term alternative to pipeline transport: pipeline transport is substantially cheaper than road and rail transport; pipeline transport is much safer than rail and especially road transport; and pipeline transport frees up alternative road and rail transport capacity. Pipeline transport is a non-containerised bulk mode of transport for the carriage of suitable liquids (for example, petroleum commodities, which include crude oil, refined fuel products and liquid petro-chemicals), gas, slurrified coal and certain water-suspended ores and minerals. InSouth Africa, petroleum products account for the majority of commercial pipeline traffic, followed by crude oil and natural gas. There are three basic types of petroleum pipeline transport systems: Gathering pipeline systems Crude oil trunk pipeline systems Refined products pipeline systems Collectively, these systems provide a continuous link between extraction, processing, distribution, and wholesalers’ depots in areas of consumption. The following activities are involved in the flow of goods between place of origin and place of consumption or application: Demand forecasting, Facility site selection, Procurement, Materials handling, Packaging, Warehouse management, Inventory management, Order processing, Logistics communications, Transport, Reverse logistics. Because cost is incurred without adding value each time goods are handled (activity 4) at a terminal or storage facility, a primary logistics objective is to eliminate handling wherever possible. With the carriage of crude oil and petroleum products by pipeline this objective is fully met. Commodity intake, haulage, and discharge are combined in one process, usually a remote-controlled operation. Pipeline transport is a non-containerised bulk mode of transport thereby obviating the need for packaging (activity 5) and returning empty containers. Pipelines provide a direct and long-term link between these origins and destinations. If necessary a continuous service can be provided with no need for a
{"title":"Logistics aspects of pipeline transport in the supply of petroleum products","authors":"W. Pienaar","doi":"10.4102/SATNT.V27I2.85","DOIUrl":"https://doi.org/10.4102/SATNT.V27I2.85","url":null,"abstract":"The commercial transportation of crude oil and petroleum products by pipeline is receiving increased attention in South Africa. Transnet Pipeline Transport has recently obtained permission from the National Energy Regulator of South Africa (Nersa) to construct and operate a new petroleum products pipeline of 60 cm diameter from Durban to Gauteng. At an operating speed of 10 km/h the proposed 60 cm Transnet pipeline would be able to deliver 3,54 million litres of petroleum product per hour. This is equivalent to 89 deliveries per hour using road tank vehicles with an average carrying capacity of 40 000 litres of fuel per vehicle. This pipeline throughput is also equivalent to two trains departing per hour, each consisting of 42 petroleum tank wagons with an average carrying capacity of 42 500 litres of fuel per wagon. Considering that such road trucks and rail wagons return empty to the upstream refineries in Durban, it is clear that there is no tenable long-term alternative to pipeline transport: pipeline transport is substantially cheaper than road and rail transport; pipeline transport is much safer than rail and especially road transport; and pipeline transport frees up alternative road and rail transport capacity. Pipeline transport is a non-containerised bulk mode of transport for the carriage of suitable liquids (for example, petroleum commodities, which include crude oil, refined fuel products and liquid petro-chemicals), gas, slurrified coal and certain water-suspended ores and minerals. InSouth Africa, petroleum products account for the majority of commercial pipeline traffic, followed by crude oil and natural gas. There are three basic types of petroleum pipeline transport systems: Gathering pipeline systems Crude oil trunk pipeline systems Refined products pipeline systems Collectively, these systems provide a continuous link between extraction, processing, distribution, and wholesalers’ depots in areas of consumption. The following activities are involved in the flow of goods between place of origin and place of consumption or application: Demand forecasting, Facility site selection, Procurement, Materials handling, Packaging, Warehouse management, Inventory management, Order processing, Logistics communications, Transport, Reverse logistics. Because cost is incurred without adding value each time goods are handled (activity 4) at a terminal or storage facility, a primary logistics objective is to eliminate handling wherever possible. With the carriage of crude oil and petroleum products by pipeline this objective is fully met. Commodity intake, haulage, and discharge are combined in one process, usually a remote-controlled operation. Pipeline transport is a non-containerised bulk mode of transport thereby obviating the need for packaging (activity 5) and returning empty containers. Pipelines provide a direct and long-term link between these origins and destinations. If necessary a continuous service can be provided with no need for a","PeriodicalId":30428,"journal":{"name":"South African Journal of Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70513166","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Account is given of the distribution and habitats of the three Lymnaea species currently on recordin the National Freshwater Snail Collection (NFSC) of South Africa. A total number of 616, 353and 202 loci (1/16th square degrees) was respectively recorded for Lymnaea natalensis, L. columellaand L. truncatula. The number of loci in which the collection sites of each species was located, wasdistributed in intervals of mean annual air temperature and rainfall, as well as intervals of meanaltitude. A temperature index was calculated for all mollusc species in the database and the resultsused to rank them in order of their association with low to high climatic temperatures. Chi-squareand effect size values were calculated to determine the significance in differences between frequencies of occurrence of each species in, on, or at the different options for each of the variables investigated and also to determine the significance of the differences between the three species. None of the three Lymnaea species were well represented in the arid regions of the Northern ,Western and Eastern Cape Province, and only L. truncatula was reported from Lesotho. Lymnaeanatalensis is the most widespread of the three species, while the distribution of L. truncatula displaysa sporadic and limited pattern. The alien invader species L. columella was first reported from SouthAfrica in the early 1940’s but was so successful in its invasion of water-bodies in South Africa thatit is currently considered the third most widespread freshwater snail in the country. Lymnaea truncatula was the only one of the three species not recovered from all 14 water-body types represented in the database. The largest number of samples of L. truncatula by far, was yielded by marshes while the largest number of samples of the other two species was collected in rivers, streams and dams. The highest percentage occurrence of all three species was in habitats in which the water conditions were described as permanent, standing, fresh and clear. Although the highest percentage of samples of all three species was reported from loci that fell within the interval ranging from 16-20°C, a significant number of samples of L. truncatula came from loci falling with in the 11-15°C interval. In view of the fact that Lymnaea species are well known as intermediate hosts for liver fluke in South Africa and elsewhere in the world, the widespread occurrence of these snails could have considerable health and economic consequences. Lymnaea natalenis is the most important and probably the only intermediate host of Fasciola gigantica, the most common liver fluke in Africa but F. gigantica has been reliably reported only from Lesotho where its traditional intermediate host, L. truncatula is widespread. However, the epidemiology of fasciolosis in South Africa has been complicated by the invasion of many water-bodies by L. columella because this species has proved to be a successful host for F. hepatica where it had been in
介绍了目前在南非国家淡水蜗牛收集(NFSC)中记录的三种林蜗牛的分布和栖息地。柽柳(lynaea natalensis)、小圆柱蒿(L. columelland L. truncatula)分别有616个、353个和202个位点(1/16平方度)。各物种采集点的位点数量分布在年平均气温和降雨量的区间以及平均海拔的区间。计算了数据库中所有软体动物物种的温度指数，并将结果根据它们与低到高气候温度的关系进行排序。计算卡方值和效应大小值，以确定每个物种在每个调查变量的不同选项中、上或下发生频率之间差异的显著性，并确定三个物种之间差异的显著性。在北、西、东开普省干旱地区均未见见，莱索托仅见过L. truncatula。三种植物中，林氏属分布最广，而短尾草属则呈零星和有限分布。外来入侵物种小圆柱螺蛳于20世纪40年代初首次在南非被报道，但它在南非水体的入侵非常成功，目前被认为是该国第三大分布的淡水蜗牛。在这3个物种中，只有截尾林(lynaea truncatula)没有从数据库中所有14种水体类型中恢复。到目前为止，在沼泽中采集的样本数量最多，而在河流、小溪和水坝中采集的样本数量最多。在水条件被描述为永久、直立、新鲜和清澈的生境中，这三种物种的发生百分比最高。虽然这三种植物在16-20°C区间内的样本比例最高，但在11-15°C区间内的样本比例也很高。鉴于在南非和世界其他地方，淋巴螺是众所周知的肝吸虫的中间宿主，这些蜗牛的广泛存在可能会造成相当大的健康和经济后果。巨型片形吸虫是非洲最常见的肝吸虫，但据可靠报道，巨型片形吸虫仅来自莱索托，而莱索托的传统中间宿主截尾片形吸虫分布广泛。然而，南非片形吸虫病的流行病学由于小柱乳杆菌对许多水体的入侵而变得复杂，因为该物种已被证明是世界其他地方引入的肝螺旋体的成功宿主。据我们所知，它在南非这方面的作用尚未得到评价。由于没有印刷的统计数据，对南非各地的牛群进行的阳性血清学测试结果被用来编制一幅地图，描绘了该国牲畜中可能出现的片形吸虫物种。尽管1975年非洲人感染片形吸虫被认为非常罕见，但情况已发生变化。在埃塞俄比亚和埃及，它被认为是一种被低估和未被报告的人类疾病。最近还报告了片形吸虫病病例增加，人类患病率高达12.8%。据我们所知，南非文献中报告的唯一人类片形吸虫病病例来自夸祖鲁-纳塔尔省北部，1981年在那里检查的7 569名学童中有22人感染了肝吸虫。向不同人士和当局索取最近人类感染统计数字的努力完全没有成功。鉴于世界其他地方的统计数字，认为南非在这方面不存在任何问题是不明智的。1995年，61个国家中患片吸虫病的人数估计已达240万人，另有1.8亿人有受感染的危险，据报告，玻利维亚、中国、厄瓜多尔、埃及、法国、伊朗、秘鲁和葡萄牙的流行率最高。最近在南非选定地区的牛群中检测片形吸虫病的血清学分析结果表明，阳性病例来自与该国三种林螨的地理分布密切相关的地方。根据文献中的报告，埃塞俄比亚高地牲畜中片形虫病的高流行率可能对该地区人民的健康产生严重影响，因为他们必须使用相同的水资源。 在南非的许多农村地区，当地居民除了与他们的牲畜共享自然水资源之外也没有其他选择。在大多数情况下，这些水体中至少有一种能维持片形吸虫生命周期的lynaea物种。在这种情况下，居民可能每天都面临被感染的风险。令人关切的是，在南非，关于人类片形吸虫病的流行病学研究是一个如此被忽视的课题。我们认为，应该进行流行病学调查，以确定人类片形吸虫病在特定地区的流行情况，这些地区可以根据三种林奈物种的地理分布作为指导原则来选择。还应努力进行调查，以更新蜗牛中间寄主的地理分布情况，并应在有危险的农村地区开展提高认识方案。
{"title":"The geographical distribution and habitats of three liver fluke intermediate hosts in South - Africa and the health implications involved","authors":"K. Kock, C. Wolmarans","doi":"10.4102/SATNT.V27I1.78","DOIUrl":"https://doi.org/10.4102/SATNT.V27I1.78","url":null,"abstract":"Account is given of the distribution and habitats of the three Lymnaea species currently on recordin the National Freshwater Snail Collection (NFSC) of South Africa. A total number of 616, 353and 202 loci (1/16th square degrees) was respectively recorded for Lymnaea natalensis, L. columellaand L. truncatula. The number of loci in which the collection sites of each species was located, wasdistributed in intervals of mean annual air temperature and rainfall, as well as intervals of meanaltitude. A temperature index was calculated for all mollusc species in the database and the resultsused to rank them in order of their association with low to high climatic temperatures. Chi-squareand effect size values were calculated to determine the significance in differences between frequencies of occurrence of each species in, on, or at the different options for each of the variables investigated and also to determine the significance of the differences between the three species. None of the three Lymnaea species were well represented in the arid regions of the Northern ,Western and Eastern Cape Province, and only L. truncatula was reported from Lesotho. Lymnaeanatalensis is the most widespread of the three species, while the distribution of L. truncatula displaysa sporadic and limited pattern. The alien invader species L. columella was first reported from SouthAfrica in the early 1940’s but was so successful in its invasion of water-bodies in South Africa thatit is currently considered the third most widespread freshwater snail in the country. Lymnaea truncatula was the only one of the three species not recovered from all 14 water-body types represented in the database. The largest number of samples of L. truncatula by far, was yielded by marshes while the largest number of samples of the other two species was collected in rivers, streams and dams. The highest percentage occurrence of all three species was in habitats in which the water conditions were described as permanent, standing, fresh and clear. Although the highest percentage of samples of all three species was reported from loci that fell within the interval ranging from 16-20°C, a significant number of samples of L. truncatula came from loci falling with in the 11-15°C interval. In view of the fact that Lymnaea species are well known as intermediate hosts for liver fluke in South Africa and elsewhere in the world, the widespread occurrence of these snails could have considerable health and economic consequences. Lymnaea natalenis is the most important and probably the only intermediate host of Fasciola gigantica, the most common liver fluke in Africa but F. gigantica has been reliably reported only from Lesotho where its traditional intermediate host, L. truncatula is widespread. However, the epidemiology of fasciolosis in South Africa has been complicated by the invasion of many water-bodies by L. columella because this species has proved to be a successful host for F. hepatica where it had been in","PeriodicalId":30428,"journal":{"name":"South African Journal of Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70513516","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The fundamental elements of what is known today as Outcome-Based Education are clearly embodied in numerous familiar models of learning, assessment, and credentialing in the non-education world that, in some cases, are many centuries old. In virtually all of these models, successful outcome performance is the clear/fixed/pre-determined/known/constant factor in the equation, and time is the flexible/variable/adaptable factor. In formal education, however, exactly the opposite pattern exists: time is the clear/fixed/pre-determined/known/ constant factor, and learning successes the flexible/variable/adaptable factor. This makes “authentic” OBE implementation extremely difficult for modern education systems to implement because they are fundamentally Time-Based – defined, organized, and driven by the calendar, schedule, and clock – not Outcome-Based as some profess. South Africa is no exception to this rule – which made its enthusiastic embracing of OBE in 1997 problematic from the start. In explaining the core fundamentals of the OBE concept and how those fundamentals evolved(particularly in North America) prior to 1997, this paper makes clear that South Africa’s Curriculum2005 initiative missed the OBE mark on almost every essential count: 1) not having a clear, compelling, and operational framework of “Exit Outcomes” on which to ground the reform and the curricular changes which drove it; 2) making no reference, either in theory or practice, to OBE’s Four Operating Principles – which enable modern day educators to get as close to “real “implementation as the Time-Based paradigm of education allows; 3) missing the mark significantly on understanding and implementing what Outcomes are – culminating demonstrations of learning– the multiple forms they take, and the multiple ways in which they can be designed and assessed;4) bogging down in micro content, assessments, marking, and record-keeping – which advanced BE implementers warn strongly against; 5) lacking the future-focused grounding of OBE designs that are legitimately called “transformational;” and 6) falling into the familiar pattern of calling its “CBO” thinking and practices “OBE.”The latter relates to an almost universal constellation of practices that make educational systems virtually unchangeable from an OBE perspective: Curriculum Based Outcomes, Content Bound Objectives, Calendar Based Opportunities, Cellular Based Organization, Contest Biased Orientations, Convenience Based Operations, and Convention Bound Obsolescence. Unfortunately, Curriculum 2005 and its key advocates appeared to take these seven CBO’s as givens, which made their continuous reference to OBE incongruous at best. Consequently, the paper argues that, had South Africa’s key educational policy makers in1997, and since, taken the time to understand the six key points above, they would have been able to make a more constructive choice about the educational reforms they sought to bring about. First, recognizing these majo
{"title":"It’s Time to End the Decade of Confusion about OBE in South Africa","authors":"W. Spady","doi":"10.4102/SATNT.V27I1.79","DOIUrl":"https://doi.org/10.4102/SATNT.V27I1.79","url":null,"abstract":"The fundamental elements of what is known today as Outcome-Based Education are clearly embodied in numerous familiar models of learning, assessment, and credentialing in the non-education world that, in some cases, are many centuries old. In virtually all of these models, successful outcome performance is the clear/fixed/pre-determined/known/constant factor in the equation, and time is the flexible/variable/adaptable factor. In formal education, however, exactly the opposite pattern exists: time is the clear/fixed/pre-determined/known/ constant factor, and learning successes the flexible/variable/adaptable factor. This makes “authentic” OBE implementation extremely difficult for modern education systems to implement because they are fundamentally Time-Based – defined, organized, and driven by the calendar, schedule, and clock – not Outcome-Based as some profess. South Africa is no exception to this rule – which made its enthusiastic embracing of OBE in 1997 problematic from the start. In explaining the core fundamentals of the OBE concept and how those fundamentals evolved(particularly in North America) prior to 1997, this paper makes clear that South Africa’s Curriculum2005 initiative missed the OBE mark on almost every essential count: 1) not having a clear, compelling, and operational framework of “Exit Outcomes” on which to ground the reform and the curricular changes which drove it; 2) making no reference, either in theory or practice, to OBE’s Four Operating Principles – which enable modern day educators to get as close to “real “implementation as the Time-Based paradigm of education allows; 3) missing the mark significantly on understanding and implementing what Outcomes are – culminating demonstrations of learning– the multiple forms they take, and the multiple ways in which they can be designed and assessed;4) bogging down in micro content, assessments, marking, and record-keeping – which advanced BE implementers warn strongly against; 5) lacking the future-focused grounding of OBE designs that are legitimately called “transformational;” and 6) falling into the familiar pattern of calling its “CBO” thinking and practices “OBE.”The latter relates to an almost universal constellation of practices that make educational systems virtually unchangeable from an OBE perspective: Curriculum Based Outcomes, Content Bound Objectives, Calendar Based Opportunities, Cellular Based Organization, Contest Biased Orientations, Convenience Based Operations, and Convention Bound Obsolescence. Unfortunately, Curriculum 2005 and its key advocates appeared to take these seven CBO’s as givens, which made their continuous reference to OBE incongruous at best. Consequently, the paper argues that, had South Africa’s key educational policy makers in1997, and since, taken the time to understand the six key points above, they would have been able to make a more constructive choice about the educational reforms they sought to bring about. First, recognizing these majo","PeriodicalId":30428,"journal":{"name":"South African Journal of Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70513564","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Due to the availability and chemical nature of some heavy metals, sub-lethal toxicant levels may persist in the ocean waters and may cause physiological problems and toxicity in invertebrates and other marine organisms. Although studies of metal concentrations in False Bay showed relatively low mean concentrations of Cd, invertebrates such as molluscs, crustaceans and many other groups are able to accumulate high levels of heavy metals in their tissues and still survive in the heaviest polluted areas. They can accumulate numerous pollutants from natural waters in quantities that are many orders of magnitude higher than background levels. Bioaccumulation ofcadmium in intertidal species could cause stress which may be measurable at the cellular level. A variety of limpet species that may serve as suitable ecotoxicological monitoring species occur in abundance on rocky shores along the South African coastline. The aim of this study was to obtain sensitivity data which could contribute to the selection of a suitable monitoring species and the eventual establishment of a species sensitivity distribution model (SSD) with a biomarker responseas endpoint. The limpets Cymbula oculus, Scutellastra longicosta, Cymbula granatina and Scutellastragranularis as well as water samples were collected at two localities in False Bay, South Africa. Analysis of water and biological samples were done by atomic absorption spectrometry. Exposures were done to three different sublethal concentrations of cadmium in the laboratory in static flow tanks over three days. There was a moderate increase in cadmium body concentrations over time. Results obtained at three exposure concentrations showed no significant differences in metal concentrations between the different C. oculus samples. Significant differences were obtained between the control and the exposure groups for each exposure time except between the control and the 1mg/L CdCl2 exposure group after 24 and 72 hours of exposure. Cd body concentrations(soft tissue) varied between 4.56 and 21.41µg/g (wet mass).Mean Cd concentrations in soft tissue of S. longicosta was considerably lower (varying between 1.18 and 19.58 µg/g Cd ) than in the tissues of C. oculus. The control group differed significantly from the 0.8 and 1 mg/L CdCl2 exposures after 48 and 72 hours. Mean Cd body concentrations in S. granular is were the highest of all exposed species, reaching a level of 148 µg/g Cd at the highest exposure concentration and differed significantly from the means of the other samples of the 0.8 mg/L CdCl2 exposure group after 72 hours and from the 1 mg/L CdCl2 group after 24 hours. Significant differences were also obtained between theCd body concentrations of C. granatina for the three exposure concentrations and three exposure times. Lysosomal membrane integrity was determined for both exposed and control animals, using the neutral red retention assay. Three of the four species showed a significant decrease in re
{"title":"Cellular biomarker responses of limpets (Mollusca) as measure of sensitivity to cadmiumcontamination","authors":"K. Reinecke, W. Schoeman, S. Reinecke","doi":"10.4102/SATNT.V27I2.86","DOIUrl":"https://doi.org/10.4102/SATNT.V27I2.86","url":null,"abstract":"Due to the availability and chemical nature of some heavy metals, sub-lethal toxicant levels may persist in the ocean waters and may cause physiological problems and toxicity in invertebrates and other marine\u0000 organisms. Although studies of metal concentrations in False Bay showed relatively low mean concentrations of Cd, invertebrates such as molluscs, crustaceans and many other groups are able to accumulate high levels of heavy metals in their\u0000 tissues and still survive in the heaviest polluted areas. They can accumulate numerous pollutants from natural waters in quantities that are many orders of magnitude higher than background levels. Bioaccumulation ofcadmium in intertidal species\u0000 could cause stress which may be measurable at the cellular level. A variety of limpet species that may serve as suitable ecotoxicological monitoring species occur in abundance on rocky shores along the South African coastline. The aim of this\u0000 study was to obtain sensitivity data which could contribute to the selection of a suitable monitoring species and the eventual establishment of a species sensitivity distribution model (SSD) with a biomarker responseas endpoint. The limpets\u0000 Cymbula oculus, Scutellastra longicosta, Cymbula granatina and Scutellastragranularis as well as water samples were collected at two localities in False Bay, South Africa. Analysis of water and biological samples were done by atomic absorption\u0000 spectrometry. Exposures were done to three different sublethal concentrations of cadmium in the laboratory in static flow tanks over three days. There was a moderate increase in cadmium body concentrations over time. Results obtained at three\u0000 exposure concentrations showed no significant differences in metal concentrations between the different C. oculus samples. Significant differences were obtained between the control and the exposure groups for each exposure time except between the\u0000 control and the 1mg/L CdCl2 exposure group after 24 and 72 hours of exposure. Cd body concentrations(soft tissue) varied between 4.56 and 21.41µg/g (wet mass).Mean Cd concentrations in soft tissue of S. longicosta was considerably lower (varying\u0000 between 1.18 and 19.58 µg/g Cd ) than in the tissues of C. oculus. The control group differed significantly from the 0.8 and 1 mg/L CdCl2 exposures after 48 and 72 hours. Mean Cd body concentrations in S. granular is were the highest of all\u0000 exposed species, reaching a level of 148 µg/g Cd at the highest exposure concentration and differed significantly from the means of the other samples of the 0.8 mg/L CdCl2 exposure group after 72 hours and from the 1 mg/L CdCl2 group after 24\u0000 hours. Significant differences were also obtained between theCd body concentrations of C. granatina for the three exposure concentrations and three exposure times. Lysosomal membrane integrity was determined for both exposed and control animals,\u0000 using the neutral red retention assay. Three of the four species showed a significant decrease in re","PeriodicalId":30428,"journal":{"name":"South African Journal of Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70513951","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Van die drie genesingsmodaliteite wat minstens sedert die 6de eeu v.C. in die Grieks-Romeinse era gebruik is, naamlik dieet en gesonde leefwyse (regimen), chirurgie, en behandeling met medikamente, is laasgenoemde die oudste. Alhoewel die Corpus Hippocraticum (5de eeu v.C.) nie ’n geneesmiddelhandboek bevat het nie, en Hippokrates oenskynlik regimen bo medikamente verkies het, was hierdie dokumente met geringe Egiptiese beinvloeding die basis van empiriese geneesmiddelterapie (sonder magiese beinvloeding) vir bykans ’n millennium. Die eerste waardige Griekse geneesmiddelhandboek is in die 4de eeu v.C. deur Diokles opgestel, en Teofrastos het as botaniese navorser ’n baanbrekerswerk oor plantaardige medikamente die lig laat sien. Die Aleksandrynse mediese skool het die kennis van farmakoterapie ’n stewige hupstoot gegee, en Herophilus het kombinasiepreparate uitgebou. Die Hippokratiese konsep dat die doel van terapie was om die liggaam gesond te hou deur sy humore en primere kragte in balans te hou, is deur die meeste geneeshere aanvaar, alhoewel afwykende stemme ook gehoor is. Min oorspronklike werk van Hellenistiese geneeshere het egter behoue gebly, en ons kennis daarvan spruit oorwegend uit die kommentaar van persone soos Celsus en Galenus uit die Romeinse era. Dioskorides se Materia Medica (1ste eeu n.C.) was ’n gesaghebbende teks. Die ontstaansgeskiedenis van die komplekse teengifmiddel, teriaka, word geskets. Die dominerende stellings van Galenus (2de eeu), steeds oorwegend op Hippokrates gebou, het tot in die Middeleeue (selfs vir die jong Christenkerk) as dogma gedien. Mettertyd het bygeloof en magiese faktore weer toegang tot terapie gekry, en dit word uitgewys dat geneesmiddels van die Grieks-Romeinse era (met uitsondering van ’n paar analgetika en dwelms soos opium) oorwegend as plasebo’s of gifstowwe ingewerk het, sonder werklik genesende aksies. Die gebruik van medikamente (veral van plantaardige aard) om siekte te hanteer, dateer sekerlik erug na heel vroee menslike ontwikkeling. In die Grieks-Romeinse era het geneesmiddels, dieet en gesonde leefwyse (regimen), en chirurgie, die drie basiese komponente van geneeskundeterapie uitgemaak. 1 In hierdie artikel word die rol van geneesmiddels in die tyd, ondersoek.
{"title":"Medications and their use in the Graeco-Roman era","authors":"F. Retief, L. Cilliers","doi":"10.4102/SATNT.V26I1.120","DOIUrl":"https://doi.org/10.4102/SATNT.V26I1.120","url":null,"abstract":"Van die drie genesingsmodaliteite wat minstens sedert die 6de eeu v.C. in die Grieks-Romeinse era gebruik is, naamlik dieet en gesonde leefwyse (regimen), chirurgie, en behandeling met medikamente, is laasgenoemde die oudste. Alhoewel die Corpus Hippocraticum (5de eeu v.C.) nie ’n geneesmiddelhandboek bevat het nie, en Hippokrates oenskynlik regimen bo medikamente verkies het, was hierdie dokumente met geringe Egiptiese beinvloeding die basis van empiriese geneesmiddelterapie (sonder magiese beinvloeding) vir bykans ’n millennium. Die eerste waardige Griekse geneesmiddelhandboek is in die 4de eeu v.C. deur Diokles opgestel, en Teofrastos het as botaniese navorser ’n baanbrekerswerk oor plantaardige medikamente die lig laat sien. Die Aleksandrynse mediese skool het die kennis van farmakoterapie ’n stewige hupstoot gegee, en Herophilus het kombinasiepreparate uitgebou. Die Hippokratiese konsep dat die doel van terapie was om die liggaam gesond te hou deur sy humore en primere kragte in balans te hou, is deur die meeste geneeshere aanvaar, alhoewel afwykende stemme ook gehoor is. Min oorspronklike werk van Hellenistiese geneeshere het egter behoue gebly, en ons kennis daarvan spruit oorwegend uit die kommentaar van persone soos Celsus en Galenus uit die Romeinse era. Dioskorides se Materia Medica (1ste eeu n.C.) was ’n gesaghebbende teks. Die ontstaansgeskiedenis van die komplekse teengifmiddel, teriaka, word geskets. Die dominerende stellings van Galenus (2de eeu), steeds oorwegend op Hippokrates gebou, het tot in die Middeleeue (selfs vir die jong Christenkerk) as dogma gedien. Mettertyd het bygeloof en magiese faktore weer toegang tot terapie gekry, en dit word uitgewys dat geneesmiddels van die Grieks-Romeinse era (met uitsondering van ’n paar analgetika en dwelms soos opium) oorwegend as plasebo’s of gifstowwe ingewerk het, sonder werklik genesende aksies. Die gebruik van medikamente (veral van plantaardige aard) om siekte te hanteer, dateer sekerlik erug na heel vroee menslike ontwikkeling. In die Grieks-Romeinse era het geneesmiddels, dieet en gesonde leefwyse (regimen), en chirurgie, die drie basiese komponente van geneeskundeterapie uitgemaak. 1 In hierdie artikel word die rol van geneesmiddels in die tyd, ondersoek.","PeriodicalId":30428,"journal":{"name":"South African Journal of Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2007-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70513459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In hierdie studie is die effek van valskermspring en vryval, sowel as van visualisering, op die balans van die outonome senuweestelsel ondersoek. Die resultate toon ’n verskuiwing na simpatiese oorheersing in die balans van die outonome senuweestelsel tydens valskermspring en vryval. Hierdie verskuiwing was statisties betekenisvol in die geval van relatief onervare springers, maar nie in ervare springers nie. ’n Soortgelyke outonome stresrespons is ook geinduseer deur visualisering van die sprong in die laboratorium. Verdere studies is nodig om te bepaal of daar ’n verskil is in die mate waartoe die ervare en onervare springers die biologiese stresrespons deur visualisering kan induseer.
{"title":"Stress response of the autonomic nervous system on skydiving and freefall","authors":"C. Grant, N. Claassen, M. Viljoen","doi":"10.4102/SATNT.V25I1.142","DOIUrl":"https://doi.org/10.4102/SATNT.V25I1.142","url":null,"abstract":"In hierdie studie is die effek van valskermspring en vryval, sowel as van visualisering, op die balans van die outonome senuweestelsel ondersoek. Die resultate toon ’n verskuiwing na simpatiese oorheersing in die balans van die outonome senuweestelsel tydens valskermspring en vryval. Hierdie verskuiwing was statisties betekenisvol in die geval van relatief onervare springers, maar nie in ervare springers nie. ’n Soortgelyke outonome stresrespons is ook geinduseer deur visualisering van die sprong in die laboratorium. Verdere studies is nodig om te bepaal of daar ’n verskil is in die mate waartoe die ervare en onervare springers die biologiese stresrespons deur visualisering kan induseer.","PeriodicalId":30428,"journal":{"name":"South African Journal of Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2006-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70513400","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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