• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 542
  • 78
  • 38
  • 24
  • 20
  • 20
  • 20
  • 20
  • 20
  • 20
  • 11
  • 3
  • 3
  • 2
  • 1
  • Tagged with
  • 802
  • 802
  • 152
  • 146
  • 123
  • 99
  • 94
  • 85
  • 79
  • 77
  • 68
  • 65
  • 61
  • 61
  • 59
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
491

Impact of a lifestyle physical activity intervention on school going children's physical activity participation

Tamara Ann Figaji January 2009 (has links)
<p>Associated with physical inactivity and obesity are numerous other health risks which have become a major health concern. A steady decrease in the levels of physical activity during childhood and adolescents have been noted in various parts of the world. The picture of low physical activity levels in developed countries is no different in developing countries. Children spend the majority of their day at school therefore a school setting is ideal to conduct physical activity intervention studies The primary aim of this study was to measure the effect of an intervention programme on the physical activity participation levels among school going children and adolescents. The study was carried out at an urban independent Catholic school. The sample, which was conveniently selected, which included 100 learners from grade 5 to 7 with parental consent. A quantitative approach using a quasi-experimental design was used in this study. Baseline data included levels of physical activity participation, Body Mass Index (BMI), hip-waist ratio, and socio-demographic variables. Physical activity was assessed with the Modifiable Activity Questionnaire for Adolescents. The Promoting Lifestyle activity for Youth (PLAY) programme was implemented at the school. This process-oriented programme shifts the focus from fitness toward regular participation in daily physical activity, and it is not intended to replace a comprehensive physical education programme.</p>
492

Extending health and safety protection to informal workers : an analysis of small scale mining in KwaZulu-Natal.

Marriott, Anna. January 2006 (has links)
This study explores the potential extension of occupational health and safety to informal small scale miners in South Africa. It was motivated by an understanding of the integral but much neglected relationship between the quality of work and the goals of poverty reduction and economic development. The study recognises that poor working conditions can reduce productivity and that work-related injury or illness is an unaffordable risk for those working without access to adequate social protection. Further, the protection of labour standards, including work health and safety, is an established basic right in those countries where relevant LLO Conventions have been ratified. Conventional occupational health and safety (OHS) regulation operates through formal employment structures and therefore offers limited or no protection to informal workers. In a country where increasing policy attention is being paid at national and local level to the employment and economic growth potential of the informal economy, this study practically explores within one sector - mining - how the institutional positions of both conventional and identified non-conventional OHS stakeholders work to constrain, or provide opportunities for, the extension of health and safety protection to those working informally. The focus on one kaolin and one clay/coal informal small scale mine site within KwaZulu-Natal and the use of in-depth interviews with workers and a range of identified stakeholders enabled a structured qualitative investigation into the health and safety challenges faced by informal miners; the nature of the support provided to small scale mining by the Department of Minerals and Energy (DME); and the institutional processes acting through national, provincial and local structures that do or could influence workers' access to OHS. The threats presented by each mine to worker and public, as well as environmental health and safety were found to be numerous and severe. There was also evidence of a negative impact of poor working conditions on both the health and economic security of the workers. Despite this, the study identified a vacuum of accountability for the labour protection of informal miners. Conventional mining OHS mechanisms are vertically driven, resource intensive and technocratic. They are both inappropriate for and inflexible towards meeting the challenges presented by informal work. In a minority of cases interdependent links between the responsibil ities of non-conventional OHS stakeholders and work health and safety are understood, but the lack of a worker focus, the institutional boundaries within which people work, their limited OHS knowledge, and the major financial and human resource constraints they face, appear to present significant barriers to any actual OHS intervention. Through the research process it became clear that the management and nature of the DME's small scale mining support strategy itself present fundamental barriers to the extension of OHS. The strategy is a product of a narrow conceptual isation of what is needed to achieve formalisation. This, and the lack of genuine worker representation and accountability within it, means that not only does the strategy fail to attend to OHS and a variety of other worker needs, but that the DME continues unchallenged in its neglect of such issues. With an understanding of the real constraints faced by both workers and the range of identified OHS stakeholders, and in view of the future plans to overhaul the existing national OHS framework in South Africa, the study concludes by outlining some practical opportunities and recommendations that could help to break down existing barriers to the OHS protection of informal workers. Conventional OHS mechanisms could be reoriented to take advantage of cheaper, simpler and more appropriate workerled approaches which could potentially achieve substantial improvements for large numbers of informal workers. Realistic opportunities also exist to more firmly secure the participation of promising non-conventional OHS stakeholders including, in this case, formal mining companies and local government. Finally, there are ways to bridge existing deep divides between social and economic institutional responsibilities that currently serve to obscure potential resource sharing and multiplier impact opportunities of working more collaboratively to improve OHS for the benefit of informal workers. / Thesis (M.Dev. Studies)-University of KwaZulu-Natal, Durban, 2006.
493

Identifying the prevalence of and pathways to diarrhoeal disease in rural KwaZulu-Natal and the implications for evaluating the impact of water supply schemes on community health.

Archer, Lynette Deborah. January 1999 (has links)
Since the establishment of a democratic South Africa in 1994, a number of rural water supply schemes have been implemented. A specific aim of these schemes is to improve the health of the population. The underlying assumption is that a supply of reticulated water will improve the quality of water used by the community, reduce the exposure of the community to contaminated water supplies, and reduce water related diseases, in particular diarrhoea. This research thesis focuses on two rural water supply schemes in KwaZulu-Natal: Mpolweni and Vulindlela, both being developed by Umgeni Water, the regional water utility. These communities depended variously on rivers, rain harvesting, and springs for their water supply. For sanitation, the majority of people used unimproved pit latrines. This research thesis is based on information gathered from the communities prior to the installation of the water supply schemes. It focuses on the linkage between water supply and health by examining diarrhoeal morbidity as a measurable disease outcome and by identifying possible pathways to the prevalence of diarrhoea. Questionnaire and observational surveys were undertaken of 181 households in Mpolweni and 100 households in Vulindlela. From these surveys, the prevalence of diarrhoea in Vulindlela households was found to be 40.4% and in Mpolweni to be 49%. Children under the age of five years old are the most vulnerable, with 20.1% of children in Mpolweni and 21 .3% of children in Vulindlela reported as having had diarrhoea in the recall period prior to the surveys. The Mpolweni study considered eighty exposure variables, finding an association between diarrhoeal disease and sixteen of these variables (p value < 0.05). The Vulindlela study considered fifty-five exposure variables, of which eight were considered significant (p value < 0.05). In regard to water and diarrhoea: • no association was found between the prevalence of diarrhoea and the source of water in either Mpolweni or Vulindlela. • using water to wash nappies was associated with diarrhoeal disease in Vulindlela. However, it is postulated that it is the faecal contamination in the nappy, rather than the water, that is problematic. No association between water use and diarrhoea was established in Mpolweni. • poor disinfection of stored water supplies was associated with diarrhoeal disease in both Mpolweni and Vulindlela. In addition, the use of plastic storage containers to store water at the household provided additional risk in Mpolweni. However, once the reticulated system is installed, the communities are likely to continue to store water due to a distrust of the reliability of water supply. The above surveys form the baseline for additional studies currently being undertaken by Umgeni Water that are intended to measure the effectiveness of the water supply schemes on community health. However, from this thesis, it is concluded that many of the risk factors associated with diarrhoeal disease in both Vulindlela and Mpolweni will not directly be addressed by the introduction of the water supply schemes. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 2000.
494

Antioxidants in Canadian boreal forest : indigenous medicinal plant treatments in relation to non-insulin dependent diabetes mellitus

McCune, Letitia M. January 1999 (has links)
Medicinal plants, as part of traditional ingestion practices, may contain antioxidants to combat the oxidative stress which is implicated in prediabetes as well as many of the complications of diabetes, As Indigenous Peoples move further from their traditional lifestyles, and therefore their use of medicinal plants, incidence of diabetes has increased dramatically, Those medicinal plants of the boreal forest that have been used for 3 or more symptoms of diabetes or its complications were selected for analysis. Three different assays (DPPH, NBT/xanthine oxidase and DCF/APPH) determined the antioxidant activity of 35 medicinal plant species. The majority of the species (89%) had free radical scavenging activity significantly greater than the market produce tested (Tukey, P < 0.05), 63% had superoxide scavenging activities similar to vitamin C, and eight species had free radical scavenging activity similar to green tea. Considering that many of these species are also used for food or beverage they represent an antioxidant benefit to the traditional lifestyle. Among the parts used medicinally, roots and barks were used the most frequently with activity in the order of fruit > bark > leaves > roots. The perennials selected had activity in rank trees > shrubs > herbs and the activity associated with habitat found rocky areas > woodland > wet/boggy habitats. Species used for symptoms such as diarrhea, rheumatism, tonic and heart/chest pain were typically high in antioxidant activity. Using cluster analysis it was determined that species used for diarrhea and heart disease as well as those used for a combination of tonic, sores, urinary, blood, pregnancy and boils could also be species with high antioxidant activity. The greater the number of symptoms a species was used for, the greater the activity. Three species with high antioxidant activities, Rhus hirta, Cornus stolonifera and Solidago canadensis, inhibited TNF production in human macrophage cells suggesting a po
495

Patterns and attitudes towards breastfeeding in the era of HIV/AIDS : a case study of Greater Mafikeng District in the North West Province in the Republic of South Africa / Shirley M. Malakane

Malakane, Shirley M January 2004 (has links)
HN/AIDS in South Africa has grown to very serious proportions. An estimated number of 5.3million South Africans are infected with HIV and the majority of these infections are in the reproductive age group. Based on Annual Antenatal survey 2002,of the total 2.95 million were women aged 15-49, with an estimation of 91271 babies infected through mother to child transmission. Breastfeeding is said to be an ideal food for growth and development of a child. Given that HIV is transmissible through breastfeeding, the paper aims at examining patterns and attitudes towards breastfeeding in the era of HIV/AIDS. A total of 400 respondents drawn from Mafikeng district were interviewed. The majority were aged 20-39, never married, rural, unemployed with high school level of education. Areas of interest were knowledge about HIV/AIDS, patterns of breastfeeding and attitudes towards alternative methods of infant feeding for an HIV positive mother. Previous reports gave clarity to HIV transmission rates at various stages of life. Evidence has shown that rates of transmission are higher in early stages than late stages of life. Few weeks of life from 6-8 weeks may particularly be a period of high risk than ages above three months. Transmission might have occurred during pregnancy, labor or through breastfeeding, whereby data has shown that colostrums have high concentration of Human Immune Virus than mature milk. The study shows that breastfeeding is still regarded as an important infant feeding method that is ideal for child's growth and development but HIV infection is seen as a disturbing factor to successful breastfeeding. Fifty four percent of respondents did not breastfeed exclusively as promoted by UNICEF and WHO; mean duration for exclusive breastfeeding is two months, support is given by SADHS 1998, mean duration for complementary feeding is two months which gives an indication that more infants are at higher risk of contracting the virus should their mothers test positive which in turn gives rise to high infant /childhood morbidity and mortality rates. There is a need to strengthen and expand programmes such as VCT and PMTCT in all communities especially in rural setting where there is lack of pure water supply and proper sanitation. Efforts to reduce the risk of transmission should therefore be centered on promoting the understanding that mixed feeding or breastfeeding with supplementary feeding carries the highest risk of HIV transmission compared to exclusive breastfeeding or exclusive formula feeding. / Thesis (M.Soc.Sc. (Population Studies) North-West University, Mafikeng Campus, 2004
496

Perceived constraints to physical activity among paramedical institution students in Uganda.

Nizeyimana, Eugene January 2005 (has links)
Research has clearly shown that all individuals will benefit from regular physical activity. Unfortunately, young adults including college and university students are not physically active on a regular basis worldwide. In the developing world particularly in Sub- Saharan Africa, physical inactivity along with tobacco use, poor diet and nutrition are increasingly parts of today&rsquo / s lifestyle. Physical activity declines with age and the most important decline appear to be during the transition period from high school to university and during university years. The aim of this study was to assess the level of physical activity, to investigate the perceived constraints to physical activity and to determine whether socio-demographic characteristic have an influence on participation in physical activity and perceived constraints to physical activity among paramedical institutions students in Uganda. A cross-sectional study with descriptive quantitative design was conducted. Four hundred (400) paramedical institution students were selected using a stratified random sampling technique. A self-administered questionnaire adopted from the literature was used to collect the data. A response rate of 90% was obtained. Descriptive and inferential statistics using the statistical package for social sciences were used to analyze the data. The relationships and associations between different variables were determined by carrying out significant tests using chi-square tests. Alpha level was set at 0.05. The mean age of the sample was 22.44 years (SD = 2.03). Males constituted 73.9% and females constituted 26.1% of the sample. Students from eight (8) health professional courses participated in the study. Over half (59%) of participants were classified as physically active and 41% were classified as inactive or sedentary. For male participants, lack of the right equipment to exercise and wanting to do other things in their free time were perceived as the major constraints to physical activity. For female participants, lack of motivation and tiredness after exercise were perceived as the major constraints to physical activity. The findings of this study demonstrate that there is an influence of socio-demographic characteristics such as gender, year of the study and different departments/schools on participation in physical activity and perceived constraints to physical activity. They also indicate the need of health promotion intervention aiming at promoting physical activity among paramedical institution students in Uganda.
497

Fatty acids as cancer preventive tools in the dietary modulation of altered lipid profiles associated with hepatocarcinogenesis.

Abel, Stefan January 2005 (has links)
This thesis consists of a brief description on cancer, carcinogenesis, the changes in the type and level of dietary fat available in our diets over time and association with the development of certain diseases. The main focus of this research was on omega 6 and omega 3 essential fatty acids (EFA) and their interaction with regards to carcinogenesis.
498

Aircraft noise and public health : acoustical measurement and social survey around Sydney (Kingsford Smith) Airport

Issarayangyun, Tharit, Civil & Environmental Engineering, Faculty of Engineering, UNSW January 2005 (has links)
The development of major commercial airports promotes the air transport industry and generates positive economic benefits to the airport and to its host economy. However, external costs are associated with these benefits. Any increase in aircraft movement causes negative environmental impacts, especially noise pollution. Governments have reduced aircraft noise levels at their sources, or introduced aircraft noise management strategies (ANMS); however the problems have never been satisfactorily resolved. This research aims at developing a better understanding of the impacts of aircraft noise on community health and well-being by exploring two core research questions: (1) ???Is health related quality of life worse in communities chronically exposed to aircraft noise than in communities not exposed????; and (2) ???Does long-term aircraft noise exposure associate with adult high blood pressure level via noise stress as a mediating factor????. The Sydney (Kingsford Smith) Airport has been selected as a case study. The health survey instruments have been developed and piloted, and then translated from English into Greek and Arabic. A postal self-administrative health survey (with follow-up letters) has been implemented in the areas surrounding Sydney Airport (called ???aircraft noise exposure group???) and in the matched control group. The total sample size was 1,500 with 47% response rate. This thesis has developed a ???new??? noise index (named Noise Gap Index, NGI) to describe and assess aircraft noise in such a way that is easily understood by the layperson. Factorial analysis of covariance revealed that ???Health related quality of life, in term of physical functioning, general health, vitality, and mental health, of community chronically exposed to high aircraft noise level were worse than the matched control area???. Binary logistic regression analysis found that ???Subjects (aged 15 ??? 87) who have been chronically exposed to high aircraft noise level have the odds of 2.61 of having chronic noise stress. In addition person who have chronic noise stress have the odds of 2.74 of having hypertension compared with those without chronic noise stress???. Finally, the robust hypotheses of effects of aircraft noise on community health and well-being for future experimental study were proposed.
499

Effects of dietary fish oil and fibre on contractility of gut smooth muscle.

Patten, Glen Stephen January 2008 (has links)
From animal experimentation, and studies using in vitro models, there was evidence in the literature to suggest that dietary fibre may influence contractility and motility of the gastrointestinal tract and long chain (LC) n-3 polyunsaturated fatty acids (PUFAs) from marine sources may influence contractility of smooth muscle cells in blood vessels. The hypothesis of this thesis was that dietary fish oil and/or fibre influence the contractility of isolated intact sections of gut smooth muscle tissue from small animal models. Methodology was established to measure in vitro contractility of intact pieces of guinea pig ileum with the serosal side isolated from the lumen. It was demonstrated that four amino acid peptides from κ-casein (casoxins) applied to the lumen overcame morphine-induced inhibition of contraction. Using this established technology, the guinea pig was used to investigate the effects of dietary fibre and fish oil supplementation on gut in vitro contractility. In separate experiments, changes in sensitivity to electrically-driven and 8-iso-prostanglandin (PG)E₂-induced contractility were demonstrated for dietary fibre and fish oil. A modified, isolated gut super-perfusion system was then established for the rat to validate these findings. It was subsequently shown that LC n-3 PUFA from dietary fish oil significantly increased maximal contraction in response to the G-protein coupled receptor modulators, acetylcholine and the eicosanoids PGE₂, PGF₂α, 8-iso-PGE₂ and U-46619 in ileum but not colon, without changes in sensitivity (EC₅₀), when n-3 PUFA as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) had been incorporated to a similar degree into the gut total phospholipid membrane pool. It was further established that the spontaneously hypertensive rat (SHR) had a depressed prostanoid (PGE₂and PGF₂α) response in the gut that could be restored by dietary fish oil supplementation (5% w/w of total diet) in the ileum but not the colon. Importantly, the muscarinic response in the colon of the SHR was increased by fish oil supplementation with DHA likely to be the active agent. Dietary fish oil dose experiments deduced differential increases in response occurred at fish oil concentrations of 1% for muscarinic and 2.5% (w/w) for prostanoid stimulators of the ileum with no difference in receptor-independent KCl-induced depolarization-driven contractility. Studies combining high amylose resistant starch (HAMS, 10% w/w) and fish oil (10% w/w) fed to young rats demonstrated a low prostanoid response that was enhanced by dietary fish oil but not resistant starch. There was however, an interactive effect of the HAMS and fish oil noted for the muscarinic-mimetic, carbachol. Generally, resistant starch increased the large bowel short chain fatty acid pool with a subsequent lower pH. Binding studies determined that while the total muscarinic receptor binding properties of an isolated ileal membrane fraction were not affected in mature rats by dietary fish oil, young rats had a different order of muscarinic receptor subtype response with a rank order potency of M₃ > M₁ > M₂ compared to mature animals of M₃ > M₂ > M₁ with fish oil altering the sensitivity of the M₁ receptor subtype in isolated carbachol-precontracted ileal tissue. In conclusion, experiments using the guinea pig and rat gut models demonstrated that dietary fish oil supplementation, and to a lesser degree fibre, increased receptor-driven contractility in normal and compromised SHR ileum and colon. Further, changes in responsiveness were demonstrated in the developing rat gut prostanoid and muscarinic receptor populations that could be altered by dietary fish oil. Preliminary evidence suggested that fish oil as DHA may alter receptor-driven gut contractility by mechanisms involving smooth muscle calcium modulation. Defining the role that dietary fibre and fish oil, and other nutrients, play in normal and diseased states of bowel health such as inflammatory bowel disease (IBD), where contractility is compromised, are among the ongoing challenges. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1316907 / Thesis (Ph.D.) -- University of Adelaide, School of Molecular and Biomedical Science, 2008
500

In vitro toxicity assessment of silver and zinc oxide nanoparticles

Johnson, Clint Edwin January 2010 (has links)
Nanotoxicology is a nascent field of study concerned with the potential for nanotechnology to adversely impact human health or result in ecological damage. Nanomaterials can display unique physicochemical properties not present in the parent bulk material and it is these properties that may be a potential source of toxicity. There are a growing number of examples of nanomaterials functioning differently in biosystems compared to the parent bulk material. With the rapid growth of nanotechnology and increasing exposure of people to novel nanomaterials there is an urgent need to evaluate the toxicity of nanomaterials. In this study the toxicities of silver and zinc oxide nanoparticles were assessed. The effects of size and surface coating on the cytotoxicity and immunogenicity of silver nanoparticles were investigated, with cytotoxicity found to be inversely proportional to nanoparticle size. The subcutaneous penetration of zinc oxide nanoparticles was assessed to determine whether this material can be safely used as a UV filter in sunscreens and cosmetics. No dermal penetration was detected using a porcine in vitro model. Zinc oxide nanoparticles were also used as a model material to investigate nano-specific toxicity by comparing cytotoxicity and changes to gene expression with bulk scale zinc oxide. In both cases cytotoxicity and changes to gene expression were greater for zinc oxide nanoparticles. Methods and techniques to test the toxicity of nanomaterials in vitro and the implication for in vivo toxicity are only beginning to be elucidated. The methods and techniques used in this study, particularly nanomaterial stabilization in biofluids and toxicity testing using blood cell cultures, may assist the establishment of standard in vitro testing protocols for nanomaterials.

Page generated in 0.1019 seconds