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1
Beyrouty, Peter. "Effects of methylmercury on reproduction and offspring development and potential benefits of supplemental selenium and vitamin E intake in rats." Thesis, McGill University, 2002. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=32762.
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Methylmercury (MeHg) is an environmental contaminant mainly present in fish and seafood. The long-term consumption of these fish and seafoods could pose a health risk to pregnant women and their children. Animal studies were conducted to assess the effects of MeHg exposure on reproduction and offspring development as well as the potential benefits of nutrient supplementation. Adult female rats were treated by gavage with MeHg at dose levels of 0.5, 1.0 or 2.0 mg/kg/day for 4 weeks prior to mating and throughout pregnancy, and then were allowed to deliver. In a second study, adult female rats were treated with MeHg at 1.25 mg/kg/day for the same duration, and they were fed diets containing an extra 1 ppm selenium (Se), or 225 IU/kg vitamin E, or both of these two nutrients, 4 weeks prior to MeHg dosing, and then throughout McHg treatment. (Abstract shortened by UMI.)
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Chapman, Laurie A. "Interactions of nutrients on methyl mercury toxicity in neuron X spinal chord hybrid cells (NSC-34) and human oligodendrocyte X rhabdomyosarcoma cells (MO3.13)." Thesis, McGill University, 2001. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=36888.
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Exposure to methyl mercury (MeHg) is a global concern. Increased chronic exposure to MeHg among fish and marine mammal consuming populations will increase the risk of prenatal exposure and as a result, the risk of infant brain damage and neurotoxcity. It is therefore important to understand the role of environmental factors, such as nutrition, in determining susceptibility to MeHg toxicity. Three nutrients (selenium (Se), vitamin C and vitamin E) were selected for examination of their interactions with the mechanisms of McHg cytotoxicity in vitro. Two hybrid neural cell lines (M03.13 and NSC-34) were evaluated for their usefulness in the study of MeHg cytotoxicity. Sixteen toxic endpoints were selected for investigation of growth, viability, structure and biochemistry. Both cell lines responded to MeHg exposure in a dose dependent manner for the majority of endpoints suggesting that both MO3.13 and NSC-34 cells undergo structural and biochemical changes during exposure to McHg, but that MO3.13 cells are more sensitive to DNA, mitochondria) membrane damage and glutathione (GSH) depletion and that NSC-34 cells are more sensitive to protein damage and apoptosis. Se exposure lessened the MeHg-induced decrease in DNA and GSH concentrations in both cell lines. In NSC-34 cells, Se also increased F-actin concentrations and prevented an increase in caspase-3 activity. Se may alter the mechanism of cell death by preventing McHg disruption of DNA replication thus maintaining the production and function of peptides (GSH) and protein (polymerized actin) that aid in MeHg detoxification and neural function. In NSC-34 cells, vitamin C prevented the induction of caspase-3 activity and lessened DNA damage and GSH depletion. Vitamin E lessened GSH depletion and lessened G-actin depletion. Both vitamin C and E improved GSH status, but vitamin C also delayed McHg damage of DNA and prevented early signs of apoptosis suggesting these two vitamins interfere with MeHg metabolism by diffe
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Huang, Wenhu. "Extracellular glutathione peroxidase purification, immunoassay, nutritional regulation and clinical aspects /." Lund : Lund University Dept. of Applied Nutrition and Food Chemistry, 1996. http://catalog.hathitrust.org/api/volumes/oclc/38100668.html.
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Lyons, Graham Henry. "High-selenium wheat : biofortification for better health /." Title page, table of contents and abstract only, 2004. http://web4.library.adelaide.edu.au/theses/09PH/09phl9915.pdf.
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Elaseer, Abdusalam S. "Transmethylation of selenium and tellurium : analytical and environmental aspects." Thesis, University of Bristol, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.240775.
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Walsh, Dominic Martin. "Biochemical aspects of vitamin E and selenium deficiency in cattle." Thesis, Queen's University Belfast, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.334686.
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Hudman, J. F. "Aspects of selenium metabolism in sheep and selected rumen bacteria." Thesis, Hudman, J.F. (1986) Aspects of selenium metabolism in sheep and selected rumen bacteria. PhD thesis, Murdoch University, 1986. https://researchrepository.murdoch.edu.au/id/eprint/53616/.
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High rates of application of superphosphate lead to lower glutathione peroxidase levels in sheep and higher incidence of nutritional myopathy. There is no convincing evidence that sulphate and selenium interact to the detriment of selenium metabolism in sheep. In this work the possible interaction of selenium and phosphorous is investigated.
Sheep fed a low selenium, low phosphate diet and intraruminally infused with either sodium phosphate or sodium chloride developed skeletal or cardiac muscle lesions. The severity of the skeletal muscle lesions was dramatically increased by the intraruminal infusion of sodium phosphate. There was no evidence of skeletal or cardiac muscle lesions in sheep fed diets adequate in selenium and infused with either sodium phosphate or sodium chloride.
Glutathione peroxidase activity in the whole blood declined more rapidly in phosphate infused sheep as compared to chloride infused sheep, suggesting that erythrocytes produced subsequent to phosphate infusion contained very small amounts of this seleno-enzyme.
Elevated plasma creatine phosphokinase activity was associated with the skeletal muscle lesions in the sheep fed a low selenium, low phosphate diet and intraruminally infused with sodium phosphate. The concentration of selenium in the livers of the sodium phosphate infused sheep was significantly lower than that of the sodium chloride infusea sheep on the same diet. The selenium concentrations of kidney, blood and cardiac and skeletal muscle of sheep fed a low selenium, low phosphate diet and subsequently intraruminally infused with either sodium phosphate or sodium chloride were similar.
The glutathione peroxidase activities and selenium concentrations in the whole blood of sheep with nutritional myopathy showed that low levels of these two parameters were not necessarily associated with nutritional myopathy nor reliable indicators of animals at risk of developing nutritional myopathy.
A study of the bioavailability of selenium incorporated into rumen bacteria showed that there were no significant differences in the tissue metabolism of 75 [SeJ associated with bacteria (derived from 75 [SeJselenite) , or from inorganic 75 [Se ] selenite or 75 [SeJselenate. The results indicated that there were differences in the metabolism of selenate and selenite by mixed populations of rumen bacteria. 75 [SeJ incorporated into bacterial cells, or that derived from inorganic selenite and selenate did not behave in the same manner after infusion into the rumen. The rate of entry into blood and plasma of 75 [Se] incorporated into bacterial cells "in vitro" was more rapid than 75 [Se] derived from inorganic selenite or selenate.
Other isotopic data showed that 75 [Sejselenium infused into the rumen was excreted predominantly in the faeces. Selenium associated with whole blood was predominantly in the plasma TCA precipitate and erythrocytes. Very little 75 [Sejselenium was present in the TCA precipitated plasma supernatant. The majority of selenium in the blood was associated with the plasma and selenium was incorporated more rapidly into the plasma than into the erythrocyte. In older sheep (>G months old) selenium incorporated into the erythrocyte was not associated with an increase in whole blood glutathione peroxidase activity at least in the short term (over 4 weeks).
Sheep fed the selenium deficient, low phosphate diet and intraruminally infused with sodium chloride developed osteoporosis, whereas there was no evidence of osteoporosis in sheep fed the same diet and infused with sodium phosphate. A dietary insufficiency of phosphate was implicated in the development of osteoporosis and the urinary excretion of calcium was elevated in the osteoporotic sheep.
There are two possible sites for this interaction of phosphorous and selenium — either within the rumen or within the animal. In the first instance, the metabolism of selenium was studied in mixed populations of rumen bacteria and then the study was continued with pure cultures of three selected rumen isolates.
A study of the incorporation of selenium into mixed rumen bacteria showed that 75 [Sejselenite was metabolised "in vitro" by mixed populations of rumen bacteria and that seleno-amino acids could be identified in the bacterial extracts. 75 [Sejselenate was not metabolised by rumen bacteria under the same conditions.
Selenite uptake and incorporation in Selenomonas ruminantium, Butyrivibrio fibrisolvens, and Bacteroides ruminicola were by constitutive systems. It was distinct from sulphate or selenate transport, since sulphate and selenate did not inhibit uptake, nor could sulphate or selenate uptake be demonstrated in the three species. Selenite uptake had an apparent Km of 1.28 mM, 1.82 mM and 1.71 mM in S. ruminantium, B. fibrisolvens and B. ruminicola respectively. The K values were associated 0.11 and 1.5 /xg Se min 1 (mg protein) 1 respectively in the three species. 75 [Sejselenite by S. ruminantium, B. fibrisolvens and B. ruminicola was sensitive to inhibition m with Vmax values of 0.15, Uptake of by 2,4-dinitrophenol (2,4,DNP), iodoacetic acid (IAA) and N-ethyImaleimide but not chlorpromazine (CPZ) or N,N1-dicyclohexy1-carbodiimide (DCCD). Azide partially inhibited selenite uptake in cells of S. ruminantium and B. fibrisolvens but not in B. ruminicola. Arsenate partially inhibited selente uptake by cells of B. fibrisolvens as did carbonyl cyanide m-chloropheny1 hydrazone (CCCP) in S. ruminantium and fluoride in cells of B. ruminicola. These compounds were not inhibitory to the other species. Transport of selenite was inhibited by sulphite and nitrite, but not by nitrate, phosphate, sulphate or selenate in cells of S. ruminantium, B. fibrisolvens and B. ruminicola. S. ruminantium and B. fibrisolvens were capable of converting 75 [Se]selenite into seleno-amino acids whereas there was no conversion of selenite into seleno-amino acids by B. ruminicola. B. ruminicola converted selenite into red elemental selenium. S. ruminantium and B. fibrisolvens also produced some red elemental selenium.
Clearly these isolated bacteria metabolise selenate and selenite in a manner different to the whole animal. Similarly phosphorous does not affect selenium metabolism in these isolated bacteria. This suggests that although phosphorous does affect selenium metabolism leading to nutritional myopathy, the rumen does not appear to be the primary site of this interaction. Therefore there is a need to look at the effect of phosphorous loading on selenium metabolism in animal tissues. One possibility is to use non-ruminant animals as a model for this effect.
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Yang, Feili Lo. "Effects of selenium status, fish oil consumption and submaximal exercise training on the selenium-related antioxidant defense system of rats /." The Ohio State University, 1990. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487677267731233.
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Carroll, Brett. "Microbial and geochemical aspects of selenium cycling in an estuarine system Lake Macquarie, NSW /." Connect to full text, 1999. http://hdl.handle.net/2123/378.
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Thesis (Ph. D.)--University of Sydney, 1999.Title from title screen (viewed Apr. 21, 2008). Submitted in fulfilment of the requirements for the degree of Doctor of Philosophy to the Dept. of Chemical Engineering, Graduate School of Engineering. Includes bibliography. Also available in print form.
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Tran, Thien Hung. "Aspects bénéfiques et toxiques du sélénium." Paris 5, 1996. http://www.theses.fr/1996PA05P132.
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Welsh, Daniel. "Selenium in aquatic habitats at Cibola National Wildlife Refuge." Diss., The University of Arizona, 1992. http://hdl.handle.net/10150/186067.
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I studied selenium contamination at Cibola National Wildlife Refuge (Cibola NWR) in the lower Colorado River Valley, California and Arizona. My objectives were to: (1) determine whether local irrigation practices resulted in exposure of fish to toxic levels of selenium; (2) assess the risks to humans of consuming fish from Cibola NWR; (3) assess whether diversity and abundance of fish were related to selenium concentrations or other water quality variables. Water, sediment, fish, crayfish, and aquatic plants were collected from sites which received irrigation return flows and sites which did not. Selenium was below toxic levels at sites receiving irrigation return flows. Selenium was at the toxicity threshhold for fish at two sites receiving water directly from the Colorado River. Concentrations of selenium in fillets of largemouth bass (Micropterus salmoides) from one lake exceeded levels that elicit consumption advisories in California. Most people would be unlikely to consume toxic amounts of fish, but an advisory should be posted to inform people about potential risks. Gill nets were used to determine species diversity and abundance. There were no strong correlations between selenium levels and indices of species richness and equitability. There was a consistent inverse relationship between selenium levels and catch-per-unit-effort for all species combined. This inverse relationship suggested that selenium may be one of a suite of factors limiting abundance of fish. Correlations between indices of species diversity and abundance and values of water quality variables generally were not significant. Temperature and salinity may have limited abundance of some species seasonally. Increases in selenium levels at sites that are already at the toxicity threshhold could impair reproduction of sensitive species. Population declines and concern about edibility of fish could impair the recreational fishery. Therefore, site-specific ways to reduce selenium accumulation should be studied and implemented. Site-specific limnological conditions may play a role in accumulation of selenium to toxic levels, but major sources of selenium appear to be upstream in the Colorado River basin rather than local agricultural practices. Therefore, selenium input to the Colorado River from sources throughout the basin should be monitored and reduced where possible.
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Carroll, Brett Ian. "Microbial and Geochemical aspects of Selenium cycling in an Estuarine system: Lake Macquarie N.S.W." University of Sydney, Chemical Engineering, 1999. http://hdl.handle.net/2123/378.
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ABSTRACT This work examined the role of micro-organisms in the biogeochemical cycling of selenium within the benthic ecosystem of Lake Macquarie, a coastal lake in New South Wales with a history of anthropogenic heavy metal contamination. Certain micro-organisms possess the ability to oxidise or reduce selenium (Fleming and Alexander, 1973; Doran and Alexander, 1977), and microbial volatilisation of selenium from contaminated sediments and soils utilising naturally-occurring microflora has been shown in overseas research (Thompson-Eagle and Frankenberger, 1992) to be a potentially effective remediation strategy. In examining the impact of micro-organisms upon the oxidation state of selenium in Lake Macquarie sediments, this work also investigated and characterised selenium (and heavy metal) concentrations, speciation and geochemical phase associations (an indicator of potential bioavailability) in the sediments. Seven distinct bacterial species indigenous to Lake Macquarie were identified in this work with the ability to reduce selenium as selenite to elemental selenium, and selenium as selenate to organic forms of selenium, including volatile methylated selenium compounds. Metabolic parameters calculated for these organisms compared favourably with those reported in the literature by other researchers. Mixed populations of sediment micro-organisms were also isolated and studied in this work for their selenite and selenate reduction abilities. Total reduction of added selenite at levels up to 100 mg/L was recorded for a number of the organisms studied in this work. A maximum specific uptake rate for selenite of 3040 mgSe(IV).(gcells)-1.(h)-1 for one isolate (Shewanella putrefaciens) was determined, exceeding rates reported in the literature by other authors. Use of the indigenous micro-organisms from Lake Macquarie for the bioremediation of selenium containing waste streams was also examined in this work and selenium reduction in an immobilised cell reactor was demonstrated with such organisms. Concentrations, speciation, sediment core profiles and geochemical phase associations for selenium were determined for sediment samples collected at a variety of sites throughout Lake Macquarie and from Wyee Creek, a selenium-impacted fluvial input to the lake. The maximum concentration of selenium obtained in this work for the lake proper was 4.04 mg/kg, considerably lower than values reported over a decade ago (Batley, 1987) but consistent with reported reductions of selenium input into the lake from the lead-zinc smelter. Selective extraction methodology (Tessier et al. and BCR methods) studied geochemical phase association of selenium in Lake Macquarie sediments and found up to 44% of selenium was in bioavailable forms. Of interest and environmental concern was levels of selenium found in sediments of Wyee Creek, which previously received overflows from the ash dam associated with the Vales Point Power Station. Sediment selenium levels of up to 300 mg/kg were determined for this creek. These were an order of magnitude or more greater than those recorded for the lake itself and are of concern as to the potential impact on benthic organisms and those animals, including humans, who consume them. While this work can only provide a 'snapshot' of conditions within Lake Macquarie at the time of the sampling events recorded herein, it does make several important contributions to the understanding of selenium biogeochemistry in Lake Macquarie. These include: presentation of the hypothesis that selenium levels in surficial sediments being deposited in the north of the lake have decreased in recent years as a result of selenium reduction measures undertaken by the lead-zinc smelter; determination that up to 44% of selenium in surficial sediments from the lake is associated with sediment phases in which selenium has the potential to become remobilized and hence possibly bioavailable; and documentation of selenium concentrations in Wyee Creek, identifying the area as having selenium concentrations an order of magnitude or more greater than the lake itself. Concerning the role played by microorganisms in the biogeochemical cycling of selenium in Lake Macquarie, this work has: identified individual isolated and mixed cultures of bacteria that can reduce selenium as selenite to lower oxidation states; identified individual isolated and mixed cultures of bacteria that can reduce selenium as selenate to lower oxidation states; identified volatile methylated selenium compounds in the headspace gases of microorganisms reducing selenate; determined Minimum Inhibitory Concentrations for selenate and selenite for organisms isolated from Lake Macquarie; identified casein hydrolysate as a preferred carbon source for selenium reducing microorganisms from Lake Macquarie; and demonstrated that bioremediation of selenium contaminated waste streams using indigenous organisms from Lake Macquarie is feasible on the laboratory scale. Further research areas suggested by this work include: additional investigations of elevated selenium levels in Wyee Creek sediments; determination of the role of microbes in in-situ selenium reduction; and optimisation of selenium biotreatment/bioremediation of selenium-containing waste streams and sediments. In summary, this work, in rejecting the null hypothesis that the oxidation states of selenium in sediments from Lake Macquarie, NSW, are independent of microbial activity and accepting the alternate hypothesis that these oxidation states are not independent of microbial activity, contributes to the understanding of the role of microorganisms in the biogeochemical cycling of selenium, having applicability to both the specific ecosystem of Lake Macquarie, NSW, and also to selenium cycling in the environment in general. In addition, this work has identified selenium contamination in Wyee Creek, one of the fluvial inputs to Lake Macquarie, which was previously been undocumented in the literature and which may pose significant potential risk to humans and the ecosystem due to sediment selenium levels one or more orders of magnitude higher than those recorded in the lake itself. Finally, this work has also identified a number of microorganisms indigenous to Lake Macquarie with the ability to reduce selenium from toxic, mobile forms to less toxic, immobile or volatile forms, and these organisms have been shown to have the potential for use in treatment of selenium contaminated waste streams and also in the bioremediation of selenium-contaminated sediments.
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Lesley, Michael Patrick. "The fluxes and fates of arsenic, selenium, and antimony from coal fired power plants to rivers." Thesis, Available online, Georgia Institute of Technology, 2004:, 2003. http://etd.gatech.edu/theses/available/etd-04082004-180307/unrestricted/lesley%5fmichael%5fp%5f200312%5fms.pdf.
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Wilt, Stephen Ray. "Effect of selenium on chemical carcinogenesis in animal models /." The Ohio State University, 1985. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487261553056718.
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Miller, Lana L., and University of Lethbridge Faculty of Arts and Science. "The effects of selenium on the physiological stress response in fish." Thesis, Lethbridge, Alta. : University of Lethbridge, Faculty of Arts and Science, 2006, 2006. http://hdl.handle.net/10133/397.
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Selenium (Se), an essential element, can bioaccumulate and become toxic. The
main toxicity symptom in fish, teratogenicity, is mediated by oxidative stress; however,
little is known about the effect of Se on the physiological stress response (PSR). The
effects of Se on the PSR and oxidative stress parameters were investigated in rainbow
trout, brook trout, and white suckers. The PSR was activated by acute and sub-chronic
laboratory exposures to NaSeO3, but not exposure to environmental levels of Se.
Species-specific sensitivity to Se may be explained by biochemical differences. Rainbow
trout (exhibit oxidative damage with Se exposure) have greater GSH reserves (cycles
with Se causing oxidative stress) than brook trout. Selenium in agricultural drain water
did not accumulate to dangerous levels in white suckers, but additional stressors (e.g.
pesticides) were present. Differences in sensitivity to Se may alter competitive
interactions between species, changing community compositions and putting additional
pressure on threatened species.xiii, 150 leaves ; 29 cm.
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Warner, Blake Matthew. "Topical Black Raspberries and Strawberries Bioincorporated with Selenium Reduce Experimental Oral Cancer." The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1367419885.
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Shank, Alba Maria Montana. "Effects of Stress on Several Immune and Health Responses of Weanling Calves." Thesis, Virginia Tech, 2002. http://hdl.handle.net/10919/34898.
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The effects of weaning stressors on several immune and health responses were measured in three experiments. Sixty-four beef calves from 2 sources were bled on d - 7 (pre-weaning), 0 (weaning), 7, 14, and 21 (post-weaning). Serum selenium (Se), neutrophil and lymphocyte counts, and glutathione peroxidase (GSH-Px) activity for erythrocytes and leukocytes were measured for each calf at each date. Erythrocyte GSH-Px activity remained constant over time, while leukocyte GSH-Px and serum Se increased on d 7 (P<0.0001). Effects of single mineral vs. multi-mineral supplementation were measured for several immune and health responses in 2 trials. Trial 1: 36 heifers weaned on-site at SVAREC were randomly assigned 1 of 2 dietary supplements: 1) no supplement; 2) 15% CP at 0.5% BW; and 1 of 3 injection treatments: 1) no treatment (control); 2) Mu-Se injection; 3) Multi-Min injection. Whole blood Se and serum Cu increased post-weaning and serum Zn decreased post-weaning. Mu-Se-supplemented heifers gained weight faster between d 14-28 vs. Multi-Min-supplemented (P=0.01) or control heifers (P=0.02). Trial 2: 48 steers purchased at auction and transported to SVAREC were randomly assigned to 1 of 4 pasture management systems: 1) control (no treatment); 2) litter fed; 3) litter applied; 4) inorganic fertilizer; and 1 of 3 injection treatments (same as Trial 1). Whole blood Se and serum Cu increased post-stress and serum Zn decreased post-stress. Oxidative burst activity decreased in Mu-Se and Multi-min supplemented steers between d 0-4 vs. control steers (P<0.01). Multi-min-supplemented steers had higher phagocytic activity vs. steers in either Mu-Se or control groups (P=0.04).Master of Science
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Kinghorn-Taenzer, April Laura. "Mercury and selenium in Beluga teeth: tools for biomonitoring and dietary exposure assessment." Thesis, McGill University, 2007. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=18438.
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Beluga teeth are evaluated as biomonitors of heavy metal accumulation in beluga soft tissues and contaminant exposure in people who consume beluga as part of a traditional diet. Selenium, which protects marine mammals from the toxic effects of mercury, was measured in beluga teeth for the first time using hydride-generation atomic fluorescence spectrometry. Tooth selenium concentrations are shown to be moderately strong predictors of liver and muscle selenium, validating the use of teeth as a selenium biomonitor. Dietary exposure to mercury from the consumption of beluga was compared between historic and modern Mackenzie Delta Inuit populations, based on measured mercury concentrations in archeological beluga teeth and modern beluga tissues. Despite higher mercury levels in modern beluga, estimated average mercury exposure from the consumption of beluga is higher for pre-industrial Inuit populations than for modern Inuit populations, due to the significantly decreased average consumption of beluga among the modern population.Des dents de beluga sont évaluées pour prévoir l'accumulation des métaux lourds dans les tissus mous, et l'évaluation d'exposition diététique pour les personnes qui consomment le beluga en tant qu'élément d'un régime traditionnel. Le sélénium, qui protège les mammifères marins contre les effets toxiques du mercure, a été mesuré dans des dents de beluga pour la première fois. C'était trouvé que le sélénium dans les dents est un facteur prédictif modérément efficace de sélénium dans le foie et les muscles, validant l'utilisation des dents comme biomoniteurs de sélénium. L'exposition diététique au mercure venant de la consommation du beluga a été comparée entre les populations d'Inuit historiques et modernes, à l'aide des dents de beluga archéologiquement préservées et des tissus de beluga modernes. Malgré le plus haut nivelle de mercure dans les baleines modernes, l'évaluation de l'ingestion diététique du mercure venant de la consommation de baleine de beluga ont été plus hauts pour les populations historiques que pour les populations modernes, à cause d'une diminution de la consommation moyenne de beluga parmi la population moderne.
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Heintz, Emelie. "Health economic aspects of diabetic retinopathy." Doctoral thesis, Linköpings universitet, Utvärdering och hälsoekonomi, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-76283.
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To ensure that the resources of the health care sector are used effectively, new technologies need to be evaluated before implementation to examine if they generate health outcomes at an acceptable cost. This information can be collected by performing health economic evaluations in which the costs and health outcomes of different technologies are compared. To estimate the effect on health care budgets, there is also a need for information about the prevalence of the specific disease. Health outcomes in health economic evaluations are often measured in quality-adjusted life years (QALYs), which are calculated by multiplying the remaining life years after an intervention by a weight representing the health-related quality of life (HRQoL) during those years. This thesis aims to provide deeper knowledge of the health economic aspects of diabetic retinopathy (DR), an eye complication that affects patients with diabetes and may in the worst case lead to blindness. The focus is on three empirical and two methodological health economic research questions. The empirical research areas cover prevalence, costs, and HRQoL related to patients with DR. The methodological research questions explore the performance of different methods for estimation of QALY weights. This is of interest since it has been argued that the most common methods for estimating QALY weights may not capture all relevant vision-related aspects of quality of life. The analyses comprehend the validity of different methods for estimating QALY weights among patients with DR and if the results of one of the specific methods for estimating QALY weights, the time trade-off (TTO) exercise, are affected by patients’ subjective life expectancy (SLE). The empirical results demonstrate that DR is seen in approximately 40% and 30% of patients with type I and type II diabetes respectively, indicating that the prevalence of DR has decreased in both of these patient groups. Healthcare costs vary considerably between different severity levels of the disease, being estimated at €26, €257, €216, and €433 per patient per year for background retinopathy, proliferative diabetic retinopathy (PDR), diabetic macular oedema (DMO), and PDR combined with DMO respectively. Blindness due to DR is associated with an increased use of transportation services, caregiving services, and assistive technologies as well as productivity losses. This suggests that preventing the progression of DR may lower healthcare costs. Patients with vision impairment due to DR have lowered HRQoL in various dimensions, but the diagnosis of DR in itself has only a limited effect on HRQoL. The results on the methodological research questions show that different methods for estimating QALY weights seem to give different results. In comparison to EQ-5D, the Health Utilities Index Mark 3 (HUI-3) is the most sensitive method for detecting differences in QALY weights due to DR, and if decisions are to be made based on values from the general public, it can be recommended for use in cost-utility analyses of interventions directed at DR. Neither of the direct methods, TTO and the visual analogue scale, seems to be sensitive to differences in visual function, and more research is needed concerning the role of vision in people’s responses to the TTO exercises. In TTO exercises with time frames based on actuarial life expectancy, the patients’ SLE has an effect on their willingness to trade off years for full health. Thus, applying time frames deviating from patients’ SLE may result in biased QALY weights. Such bias may appear stronger within patient populations than within the general public. In conclusion, this thesis offers estimates for prevalence, costs, and QALY weights that can be used in economic evaluations of interventions directed at DR and as benchmarks for future DR research in order to follow up consequences of changes in diabetes care. In addition, it demonstrates that the choice of method for estimating QALY weights may have an impact on whether an intervention is considered cost-effective.
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Rickayzen, Benjamin David. "Some actuarial aspects of health insurance." Thesis, City University London, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.446443.
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Martinez, Cynthia Therese 1969. "Selenium levels in selected species of aquatic birds on Imperial National Wildlife Refuge." Thesis, The University of Arizona, 1994. http://hdl.handle.net/10150/278452.
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Five species of waterbirds were collected from five sites on Imperial National Wildlife Refuge between April and August of 1993. There were previous baseline contaminants data for all sites. Sites were of two distinct habitat types. Backwater lakes have a direct connection to the mainstem of the Colorado River, and seep lakes receive river water only via seepage through the soil column. Selenium concentrations in liver, kidney, and muscle tissues were consistently higher in birds collected from backwater lakes than those collected from seep lakes. Eighty-one percent of the birds collected on backwater lakes (n = 52) were above the effect threshold for reproductive impairment or embryotoxicity (10 ppm dry weight in livers). Herbivorous birds had significantly (p ≤ 0.05) lower tissue selenium levels than those species feeding on animal matter. Of the birds feeding on fish and invertebrates, 83% (n = 47) had selenium levels in liver above the effect threshold. Differences in selenium concentrations based on diet suggest food chain cycling of selenium. Eggs from waterbirds as well as those from neotropical migrants were above the 3 ppm embryotoxicity threshold.
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Reineholm, Cathrine. "Psychosocial Work Conditions and Aspects of Health." Doctoral thesis, Linköpings universitet, HELIX Vinn Excellence Centre, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-95578.
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Today’s working life has led to new requirements and conditions at the workplace, and additional factors may be of importance for employees’ health. Most earlier research has taken place in stable organizations, and has not taken changes in organizations into account. The way in which psychosocial work conditions affect employees’ health and well-being has been the topic of several studies but mental ill health is still one of the most common causes of sick leave in Sweden. Little attention is given to the importance of the workplace and organizational context for employees’ health. The overall aim of this thesis is to investigate how different aspects of health are associated with psychosocial work conditions in today’s working life. This thesis comprises two empirical studies. The first study is a longitudinal study, based on questionnaire data from 1010 employees at the Swedish Labour Market Administration. The second study is designed as a prospective cohort study, based on questionnaire data from 8430 employees in ten organizations, participating in the LOHP project. Linear and logistic regressions were performed to investigate associations between psychosocial work conditions and different aspects of health. Multilevel analysis was performed in one paper. The main findings in Paper I are that traditional job stress models are better for predicting ill health than good health. Different psychosocial work conditions may however, be useful for measuring different aspects of health, depending on whether the purpose is to prevent ill health or to promote health. In Paper II, psychosocial work conditions and symptoms of burnout were found to differ between different hierarchical levels, and different psychosocial work conditions were associated with symptoms of burnout at different hieratical levels. Paper III showed that psychosocial work conditions predict voluntary job mobility, and this may be due to two forces for job mobility: job dissatisfaction and career development. In Paper IV, a strong association between high work ability and better performance was found. Clear goals and expectations may result in improved psychosocial work conditions and work ability, which in turn affects employees’ performance. This thesis has provided knowledge regarding different aspects of health and psychosocial work conditions. Conditions at the organizational and workplace level set the prerequisites for if and how employees use their resources and their ability to act. Access to resources and the capacity to use them may vary depending on the employees’ hierarchal position. Occupational health research needs to focus on differences in psychosocial work conditions at different hierarchical levels. Organizations with clear goals and expectations may create more favourable conditions at work, supporting employees’ room for manoeuver, social capital and their ability to cope with working life, hence promoting health. Health promotion has a holistic approach and considers the work environment, the individual and the interplay between them. However, most health interventions at workplaces are directed to employees’ health behaviour rather than improvements in organizational and work conditions. To develop a good work environment it is necessary to identify conditions at work that promote different aspects of health. These conditions need to be tackled at the organizational, workplace and individual level, as good health is shaped by the interplay between the employee and the conditions for work.
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Hreinsson, Julius, and Yonathan Woldearegay. "Internationalization of health care services : Networking aspects." Thesis, Uppsala universitet, Företagsekonomiska institutionen, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-243306.
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Principles of business management are increasingly being used to analyze health care systems. Conceptualizing health care as business networks offers the possibility to apply the ARA model of Actors, Resources and Activities to understand the functioning of the system. We have used this model to study the phenomenon of networking in cross-border care using Uppsala University Hospital as a research case. The aim of the study was to understand actor’s perceptions of networking activities and how these related with international sales of health care services. We collected primary data through five interviews with managers involved in internationalization and a survey study with 26 managers at the hospital. Secondary data on patient flows and research activity was collected from hospital and university records. The main actors identified in the health care networks are doctors with professional identity being an important facilitating factor. Patient´s role as active participators in the system is increasing while researchers, innovators and key opinion leaders are also important. Networking activities consist of knowledge transfer via lecturing, meetings and external consulting activities. Resources in the form of supporting clinics, research centers and administrative services correlate positively with the level of internationalization. The study identifies networking activities as important for internationalization and cross-border sales of health care services. We conclude that the ARA model is a valuable instrument for analyzing cross border activities and internationalization of health care.
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Robertson, Kevin. "Health-related psychological aspects of playing squash." Thesis, Liverpool John Moores University, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.282785.
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Leo, Jared. "Capturing temporal aspects of bio-health ontologies." Thesis, University of Manchester, 2016. https://www.research.manchester.ac.uk/portal/en/theses/capturing-temporal-aspects-of-biohealth-ontologies(a2f5868e-94e3-4d4b-bd1e-311358ebf7e0).html.
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Extending Descriptions Logics (DLs) with a temporal dimension to aid in the ability to model meaningful temporal information is an active and popular research area that has gathered a lot of attention over recent years. DLs underpin the Web Ontology Language (OWL) which offers a way to describe ontologies for the semantic web. Representing temporal information in ontologies plays an important role, specifically for those ontologies where time information is inherently embedded in the information they describe. This is very common for ontologies in the bio-health domain, for example ontologies that describe the development of anatomies of biological entities, stage based development, evolution of diseases and so on. As expressive as DLs are, given that they are fragments of First Order Logic, they are static in nature and are limited in what they can express from a temporal view point, hence the surge in temporal extensions to DLs over recent years. In this thesis we investigate the use of temporal extensions of DLs as suitable representations for the temporal information required for bio-health ontologies. We first set out to find out exactly what types of temporal information need to be modelled, before going on to evaluate current temporal extensions and representations to determine their suitability. We then go on to introduce several new temporal extensions to DLs and evaluate their suitability.
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Bamford, Margaret. "Aspects of health among an employed population." Thesis, Aston University, 1993. http://publications.aston.ac.uk/10867/.
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This survey collected information on aspects of health amongst an employed population, employees in 14 different organisations in the West Midlands Regional Health Authority; and was a stratified sample of senior managers, middle managers and operatives. Nine hundred and sixty questionnaires were distributed asking for both quantitative and qualitative information on 58 questions covering health, work, family, leisure activities and life-style. A response rate of 48% (459 returned questionnaires) came from 290 men (63%), 165 women (36%) and four people (1%) who did not answer the gender question. The initial findings from this study are unique in that there has not been a specific review of the health of people at work. In answer to the main research questions, 92% felt they were healthy. Compared to others of a similar age, 34% felt their health was `above average', 58% `average', and 7&37 `below average'. Thirty two percent of respondents had visited their GP in the past 1-2 months; the highest reason given was disorders of the respiratory system, 20%. People's perceptions on the effects of work on their health were: good effect, 13% fair effect, 20% no effect, 27% poor effect, 27% and bad effect, 7%. The effects of leisure activities on health were thought to be more positive: good effect, 46% fair effect, 20% no effect, 21% poor effect, 3% and bad effect, 2%. The perceptions of effects of life-style on health were considered to be: good effect, 32% fair effect, 32% no effect, 20% poor effect, 9% and bad effect, 1%. In this survey, leisure and life-style were seen by employees to have more beneficial effects on health than work. Future implications include a review of occupational health as a major policy development area within primary care. There is a need to influence the education and training of health care practitioners in order to affect their ability to practise effectively in this new and challenging area of work.
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Hutchinson, Karen Hallie. "Evaluation of By-product Feedstuffs, Level of Concentrate, and Selenium and Vitamin E Injections on Performance and Health of Beef Calves in Backgrounding Systems." Thesis, Virginia Tech, 2003. http://hdl.handle.net/10919/33105.
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Weaning stress in young calves is often compounded with stress from transport, marketing, and commingling. The result is a weakened immune system, which can lead to increased incidence of diseases, especially bovine respiratory disease complex (BRDC). Backgrounding cattle post-weaning and prior to feedlot entry may alleviate some of the more common stresses and typically diminished feed intake. Five trials were conducted with a total of 228 weaned calves to evaluate different backgrounding systems. Drylot diets with 70:30 and 40:60 forage to concentrate total mixed rations with Se and vitamin E injections were studied. No differences were observed in daily gains or feed efficiency among treatments. Steers receiving Se injections had higher (P < 0.05) blood Se concentrations on d 7, 14, 28, and 42. Steers grazed four types of stockpiled pastures with previous pasture treatments: control, poultry litter fed to previous grazing cattle, poultry litter applied, and inorganic fertilizer. Supplements (16% CP) for each pasture treatment were none, soy hulls + SBM (0.5% BW), and corn + SBM (0.5% BW). On d 7, unsupplemented steers had higher (P < 0.05) daily gains than steers supplemented with corn + SBM. No differences were detected on any other day. Heifers grazed stockpiled fescue and were fed three 16% CP supplements: corn gluten feed + soy hulls (0.5% BW), corn gluten feed + soy hulls (1.0% BW), and soy hulls + SBM (0.5% BW). On d 14, heifers supplemented with soy hulls + SBM had higher (P < 0.05) cumulative daily gains. No other differences were detected in gains among treatments. Steers were allotted to four injection treatments: none, Se, vitamin E, and combination of Se and vitamin E. There were no differences in daily gain or blood Se concentrations on any day among all treatments. Steers grazed two pasture types: fescue and fescue + alfalfa, with the following injections: none, vitamin E, and Se. There were no differences in daily gains among all treatments. On d 7, 14, 28, and 42, steers receiving Se injections had higher (P < 0.05) blood Se concentrations. On d 7 and 14, steers grazing fescue pastures had higher serum alpha-tocopherol concentrations than steers grazing fescue + alfalfa pastures. There were no differences in serum alpha-tocopherol concentrations due to injection treatment on any day. No consistent differences were detected in forage and blood serum mineral concentrations in all trials. There were no differences in gains from by-product supplementation versus â traditionalâ corn-based supplementation, suggesting that by-product feedstuffs may be of value for backgrounding rations. Selenium and vitamin E supplementation did not have any significant effect on calf morbidity.Master of Science
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Mei, Jenny J. "The relationship between dietary and supplemental selenium, magnesium, zinc, and copper intake and depression score in older adults." Thesis, California State University, Long Beach, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10105270.
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The importance of investigating relationships between depression and mineral intake is necessary due to concerns over the mental health and nutrition status of the growing older adult population in America. Due to lack of research in this area, the development of nutrition therapies for depressed older adults with special consideration for minerals is hindered. This study explored whether mean depression scores significantly differed between quartile intake groups of selenium, magnesium, zinc, and copper in a nationally representative sample of older adults (n = 901) from the 2011-2012 National Health and Nutrition Examination Survey (NHANES). For all four minerals, those within the highest quartile of intake had significantly lower depression scores than those within the lowest quartile. Nutrition and mental health care professionals should be aware of a possible association between mineral intake and depression and emphasize healthy eating patterns and nutrient-dense diets to maintain optimal mental and physical functioning.
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Viswanathan, Uma Maheswari [Verfasser], and Claus [Akademischer Betreuer] Jacob. "Study of antimicrobial, biochemical and nanotechnological aspects of novel sulfur, selenium and tellurium compounds / Uma Maheswari Viswanathan. Betreuer: Claus Jacob." Saarbrücken : Saarländische Universitäts- und Landesbibliothek, 2014. http://d-nb.info/1058360779/34.
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Rusk, Monica Kirsten 1967. "Selenium risk to Yuma clapper rails and other marsh birds of the lower Colorado River." Thesis, The University of Arizona, 1991. http://hdl.handle.net/10150/278053.
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I estimated the risk of selenium toxicity to endangered Yuma clapper rail and other marsh birds of the lower Colorado River (LCR). I collected sediment, invertebrates, Virginia rails, and least bitterns from 4 locations within the LCR valley, in May-August 1990, and collected additional bird species from 1 of the sites in April 1991. I analyzed the samples for selenium and other trace elements. Selenium accumulated in the backwater marshes of the LCR and was uniformly distributed among the backwaters sampled. Selenium increased 1-16X between successive trophic levels, however, selenium levels did not differ significantly among species with different diets. Based on the selenium levels in bird tissues and prey species, marsh birds in the LCR valley are at low risk of adult mortality, but moderate to high risk of teratogenicity. The rate of selenium accumulation in the backwaters must be reduced to decrease the risk of toxicity.
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Franks, Susan F. (Susan Faye). "Negative Psychological States: Predictors for Immunological Health." Thesis, University of North Texas, 1992. https://digital.library.unt.edu/ark:/67531/metadc332521/.
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Relationships of negative psychological conditions with general status of cell-mediated and humoral immune systems were investigated. A unique approach was utilized in that indexes representing multiple aspects of each branch of the immune system were employed to better indicate general immunological status. Differences in emotion-immune interactions between males and females were demonstrated. Results indicated a positive relationship between Trait Anger and Cell-Mediated Immunological Index. Particular criticisms of previous psychoneuroimmunological research were met by addressing sex differences and differences in various conditions of anger and depression, as well as through assessment of cumulative effects of negative emotions on immune system status. Directions for future research in eddressing similar issues are suggested. In general, results provide support for validity of mindbody interactionism and imply the need for revision of standard medical and psychological treatment.
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Schützhold, Svenja [Verfasser]. "Aspects of oral health in the German Oral Health Studies / Svenja Schützhold." Greifswald : Universitätsbibliothek Greifswald, 2016. http://d-nb.info/1082577367/34.
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Shirazi, Farshad 1963. "Metabolic aspects of neonatal rat cardiomyocyte hypertrophy." Diss., The University of Arizona, 1997. http://hdl.handle.net/10150/282447.
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The consensus view is that cardiac hypertrophy is an adaptive response to increased work caused by a variety of stimuli. While hypertrophy can be defined as an increase in cell mass without an increase in cell number, not all increases are equivalent in type and amount of protein accumulated. Our goal in this study was to identify the common steps in the process of cardiac hypertrophy. Our working hypothesis was that in all forms of cardiac hypertrophy glucose utilization increases and that the percentage of energy derived from fatty-acid oxidation decreases. The first part of this study entailed the development and characterization of a neonatal rat heart cell model. The model had to provide uniform culture conditions for rapid development of hypertrophy by agents acting at different sites in the cardiomyocytes. The second part of this study was composed of an assessment of hypertrophy caused by four pharmacologically distinct agents: norepinephrine, angiotensin-II, endothelin-I and tetradecylglycidic acid. In this part we compared the quantity of protein accumulation and quality of hypertrophy cause by each agent. This task was accomplished by examining the effect of each agent on selected mRNA messages and alteration in DNA content of cardiomyocytes. Here we also examined the effect of protein kinase-C, endothelin-I and angiotensin-II inhibitors on hypertrophy caused by each agent. In the final part of this study, metabolic alteration in hypertrophy caused by each agent was assessed for a potential common pathway to hypertrophy. As part of this analysis, we examined changes in glucose and palmitate oxidation, glucose uptake and role of pentose pathway in hypertrophy resulting from treatment of cardiomyocyte by each agent.
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Chamberlin, Christine M. "Workaholism, health, and self-acceptance." Virtual Press, 2001. http://liblink.bsu.edu/uhtbin/catkey/1213153.
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The present study was designed to address the issue of the potential harm of workaholism. It specifically examined the relationships between workaholism, self-acceptance, psychological well-being, and physical symptoms. Furthermore, participants completed a form to rate their perceptions of their parents work behaviors, and thus relationships between perceived parental workaholism, physical symptoms, psychological well-being, and self-acceptance, were also explored.Three hundred forty seven students from a Midwestern university completed a survey measuring the above constructs. Of these 347 surveys, 279 were utilized for analysis. It was hypothesized that students' workaholism would correlate negatively with the students' psychological well-being and self-acceptance, and positively with physical health complaints. It was expected that student workaholics would report less psychological well-being, more physical complaints, and less self-acceptance than nonworkaholic students. Furthermore it was hypothesized that there would be no relationship between perceived parental workaholism and students' workaholism. While it was hypothesized that students who perceive their parents as workaholic would report less psychological well-being and self-acceptance than students with perceived nonworkaholic parents, it was not expected that they would report more physical health complaints.Results supported the majority of the hypotheses. A negative relationship was found between students' workaholism and the students' psychological well-being and self-acceptance, while a positive relationship was found between students' workaholism and physical health complaints. Students in the medium to high risk workaholic group were found to have significantly more physical health complaints, and lower self-acceptance and psychological well-being than students scoring in the low risk workaholic group. Furthermore, students with perceptions of parental workaholism falling within the medium to high risk range, had significantly lower levels of psychological well-being and self-acceptance than parents falling within the low risk range. No differences were expected in these two groups in terms of physical health complaints, however students' with perceptions of parental workaholism in the medium to high risk range had significantly more physical symptoms than students' with lower perceptions of parental workaholism. Furthermore, while no correlation was expected between perceived parental workaholism and student workaholism, a significant positive correlation was found.Department of Counseling Psychology and Guidance Services
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Urassa, David Paradiso. "Quality Aspects of Maternal Health Care in Tanzania." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distrubutör], 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-4221.
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Slattery, M. "Demographic aspects of resource allocation to Health Services." Thesis, University of Southampton, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.374235.
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Allin, Sara. "Examining aspects of equality in Canada's health system." Thesis, London School of Economics and Political Science (University of London), 2009. http://etheses.lse.ac.uk/2326/.
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Canada's health system is based on the firmly-held belief that the receipt of care should be based on need and not ability to pay. This thesis examines three aspects of this equity goal: provincial variations in equity in the receipt of care; the role of private prescription drug insurance in explaining inequity in the use of physician services; and the equity implications of subjective unmet need. Canada's provinces are responsible for planning and funding most publicly insured health services, hence there is variation in health system characteristics across the country. In the context of such variation, the first empirical analysis examines equity in the use of health services across the provinces. The analysis reveals some evidence of inequity in the likelihood of a GP visit, and the likelihood and number of specialist and dentist visits; some variations can also be found across the provinces. The second empirical analysis investigates the role of complementary insurance for prescription drugs in explaining inequity in the use of publicly-funded physician services. Due to the complementary relationship between prescription drugs and physician services, and the unequal distribution of private insurance coverage across income groups, inequity in physician utilisation partly can be explained by the interaction with insurance. The third empirical analysis assesses the equity implications of subjective unmet need. It finds that there are different utilisation patterns among the different types of unmet need, which raises methodological and conceptual challenges. The concluding chapter positions the three empirical studies within the broader policy context, offers an in-depth discussion of their methodological and policy implications, and proposes areas for future research.
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Mani, Kevin. "Abdominal aortic aneurysm epidemiological and health economic aspects /." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-110810.
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Hu, Qiming, and 胡啟明. "Application of nudge theory for changing diet and physical activity : a systematic review." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2014. http://hdl.handle.net/10722/206943.
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Background: Unhealthy lifestyle are important contributors to chronic illness in Hong Kong and worldwide. Lifestyle modification, particularly improving healthy diet and physical activity, can prevent the development of various chronic illnesses, improve disease conditions, reduce the risk of complications and enhance the quality of life. Many behavioural models have been applied to achieve lifestyle modification, but the major limitation was that they mainly treated human behaviours as individual behaviours that were subsequent to rational thinking. Nudge theory, an advanced behavioral concept, proposed to change individual’s motivation, incentives and decision making through non-direct suggestion and non-forced reinforcement. However, the application of Nudge theory has been challenged on the lack of evidence to prove its effectiveness, and its controversial framework for ethical analysis.
Objectives: This review was to synthesize the empirical findings about the effectiveness of using nudge theory for lifestyle modification including healthy diet and physical activity.
Methodology: Interventional and experimental studies that were conducted based on Nudge theory to change diet or physical activity was identified from the published literature. The studies were divided into two large groups according to outcome measured: healthy diet and physical activity, and they were systematically synthesized. The “nudges” used in these studies were categorized as six types of “nudges” summarized by “nudge unit” as “MINDSPACE” for further discussion. The type of “nudges” that were used in the studies and their effectiveness on changing diet and physical activity was abstracted.
Results: Totally, nine articles that met the inclusion criteria were included. Five nudges were identified from the included studies, including Priming (P), Default (D), Salience & Affect (SA), Incentives (I) and Messenger & Norms (MN). It is found that the strategies and methods applied on the same nudge may have different effectiveness. Seven studies applied Priming (P) as nudge to motivate change in diet, which used two major strategies: “availability” and “accessibility”. The evidence was strong that altering the availability of food presence could be effective to change food selection. The results of studies using accessibility were heterogeneous and contradictive with each other. Another three studies used different nudges including Default, Salience & Affect and Incentive. The effectiveness of Default (D) as nudge seemed to be blurry, and the sustainability remained questionable. The ethical consideration is always the primary pillar for applying nudging theory. As long as the applications are stick to necessary ethical concerns, the nudging model can be beneficial through mild “manipulation” rather than harmful.
Conclusion: It has potential opportunity to carry out “libertarian paternalism” in Hong Kong. However, it is still a long way to take application of nudging model into regulation, legislation and daily practice. The evidences for each type of nudge were not consistent and enough. Besides, the monitoring and evaluation are not available yet. Future research can be focused on transferring these applications into real practice with an effective monitoring and evaluation system.published_or_final_version
Public Health
Master
Master of Public Health
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Wood, Susan. "Mental health literacy and mental health in at-risk populations." Thesis, University of Warwick, 2016. http://wrap.warwick.ac.uk/88088/.
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This thesis explores mental health literacy (MHL) and mental health difficulties in at-risk populations. Young people, particularly males, are vulnerable to the onset of mental health difficulties, failing to access support and increased risk of suicide. Supporting people with mental health difficulties and improving prognosis is an important area of public health concern. Chapter one is a systematic review of gender differences in MHL of young people (ages 12-25 years). 14 studies were identified and critically assessed. The nature of gender differences in MHL of young people is complex but most consistently reported in depression. Females tended to have higher levels of MHL than males. The implications for public health interventions and future research are discussed. Methodological components of MHL research, such as the use of case vignettes are also considered. Chapter two is a qualitative research study of male professional footballers’ lived experiences of mental health difficulties and help-seeking using interpretative phenomenological analysis. One superordinate theme emerged from the data; Survival. This is discussed through six subordinate themes and alongside existing literature pertaining to identity, transition, personality and emotional development. The clinical implications of the findings are discussed, as well as suggestions for future research. Chapter three is a reflective paper considering the use of Cognitive Analytic Therapy as a tool for reflexivity in qualitative research. The opportunities and limitations of this approach are considered, alongside reflections on the research process.
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Munro, Catherine A. M. "Developing a dialogue on health : user involvement in health and health services." Thesis, University of Glasgow, 2008. http://theses.gla.ac.uk/291/.
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In common with other areas of public services, recent years have seen a shift in the National Health Service (NHS), with increased power and authority transferring from professionals towards the users of services. As a result, user involvement has come to form a central element of government policy on public services, and health in particular, with a series of specific policy commitments to give users a stronger voice and to involve them in the health service having been published by both the Westminster and Scottish parliaments. These seek to increase users’ involvement in making decisions about their own care and treatment, in examining and improving the quality of services and in policy and planning activity. In doing so, this policy aspires to respond to the changing culture of personal and societal expectations of health and the health service; to build democratic participation in the difficult targeting and rationing decisions faced by health agencies and, thus, to help renew public trust and strengthen confidence in the NHS. These are ambitious aims with far-reaching implications as they represent a transformation in the interaction between users, health professionals and health policy makers. This thesis examined how this policy has been understood and implemented in the NHS by exploring the scope, relevance and quality of the user involvement processes available in three health service settings. In order to develop a better understanding of the issues in user involvement it explored the nature of user participation; the character of user representation and the barriers and facilitators to user involvement in maternity, gynaecological oncology and mental health services. The study examined the response to this policy within these three settings; the functioning of existing user involvement mechanisms and their capacity to involve users in determining their individual health care and in shaping health services and policy to their definition of need. From this examination it defined the key features of a model process for user involvement within the professional service culture and organisational ethos of the NHS. The study then drew conclusions on the capacity of these current user involvement processes to deliver on the policy directive to develop both individual treatment and health services in ways that are responsive and accountable to users. Finally, the thesis identified those areas that require further research before proposing the lessons for the further development of this significant and potentially influential policy directive.
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Lye, Ellen Jane Davey. "Effects of dietary selenium, vitamin E, and fibre on methylmercury toxicity and kinetics in male Sprague-Dawley rats." Thesis, McGill University, 2006. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=101619.
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Mercury is an environmental contaminant of concern, particularly for fish eating populations. The objective of this study was to assess the effects of selenium, vitamin E, and phytate on methylmercury (MeHg) toxicity and kinetics in rats. Results show that increased selenium increases McHg in the liver, kidney, and frontal lobe of the brain, while increased vitamin E increases MeHg in the kidney but lowers McHg in the liver. Increased phytate resulted in a significant increase in MeHg in the frontal lobe. Methylmercury-treated rats on all diets showed an increased trend in muscarinic acetylcholine receptor (mAChR) binding in comparison with untreated rats. There was no change in monoamine oxidase (MAO) activities in all treatment groups. These results suggest that nutrients can alter the toxicokinetics of MeHg but none of them show clear protection in neurotoxicity in adult rats.
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Warren, Ann Marie. "Partner abuse: Health consequences to women." Thesis, University of North Texas, 2003. https://digital.library.unt.edu/ark:/67531/metadc5534/.
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Intimate partner violence is endemic in the United States. According to the American Medical Association (1992), one-fifth to one-third of women will sustain violence from a partner or ex-partner in their lifetime. The relevant literature was organized by ICD-9-CM categories. This study examined the health consequences of partner abuse in a sample of community women using a sample consisting of 564 women in three ethnic groups. Because prior research has failed to account for variations by type of abuse on health consequences, this study assessed psychological abuse, violence and sexual aggression by women's partners. To determine whether or not different types of abuse had an effect on women's health, hierarchical regression analyses were conducted. The regression equations were calculated for women within each ethnic group to facilitate identification of similarities and differences and to control for ethnic differences in risk for specific diseases. The results were consistent with past research on health consequences of abuse and extended the prior literature by showing that psychological abuse had a pervasive effect on health conditions, distress and use of health care resources. Additionally, ethnic differences emerged. As expected, ethnicity appeared to function as a moderator. Clinical implications and recommendations are made for future research, suggesting the development of a new assessment tool for partner abuse screening.
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Mingotti, Nicola. "Passive environmental design for health." Thesis, University of Cambridge, 2015. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.709015.
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Wynchank, Sinclair. "Aspects of paediatric gastro oesophageal scintigraphy." Doctoral thesis, University of Cape Town, 1988. http://hdl.handle.net/11427/27191.
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This work is concerned with the application of scintigraphy in studies of foregut motility in paediatric patients; notably oesophageal transit during swallowing, gastro oesophageal reflux (GOR) and stomach emptying as measured by the gastric contents 30 and 120 minutes after deglutition of liquid. Relevant anatomy, physiology, pathophysiology and non-radioisotopic methods of gastro oesophageal examination are outlined. The extremely important question of dose deposited by ionising radiation in paediatric patients is also considered. Because currently available estimations of absorbed dose after swallowing non- absorbable radionuclides are unsatisfactory and often contradictory, a new model was derived. It is based on more physiological principles than previous models, with a continuously varying exponential passage between four compartments in the gastrointestinal tract. From a review of previous work and our experience, a standard method of examination was developed. There is emphasis on normal physiological manoeuvres. The broad extent of useful information available in the study stems from the positions in which the patient is investigated, the quantity of labelled fluid swallowed, its physiological nature and observations of oesophageal transit, GOR, gastric emptying and pulmonary aspiration after two hours. The wide range of paediatric problems amenable to investigation by this means is described, including those of a life-threatening nature. Also, the importance of using this examination to determine the likelihood of successful surgical intervention in the gastro oesophageal region is explained. By using the observations made during swallows in neonates, the closure of the lower oesophageal sphincter (LOS) was observed during a short series of rapid deglutitions. This extends previous knowledge of the function of the neonatal LOS. These findings were very clearly demonstrated by the condensed image technique. A comparison between the abilities of radiology and scintigraphy to detect GOR in paediatric patients, with and without oesophagitis, gives unequivocal results in favour of scintigraphy. Two independent clear correlations between oesophageal transit time and the severity of GOR and age are demonstrated by variance and correlation analysis. The mean duration of GOR, maximum height of a GOR, gastric contents 30 and 120 min after deglutition, the effect of the nature of liquid swallowed and age are also examined and their relations are described. The application of the method to assess drug response is illustrated by the paediatric use of cisapride, an experimental drug which increases acetylcholinesterase release. The deductions from this work include values of the radiation dose deposited in paediatric patients of various ages, after swallowing non- absorbed Tc-99m compounds. Other contributions are a scintigraphic means to allow recognition of the importance of oesophageal dysmotility in paediatrics, especially in the absence of GOR and its relevance to the efficacy of surgery in cases of apparent GOR. Also, this gastro oesophageal scintigraphic study provided information on the paediatric use of cisapride, the relevance of GOR to repeated respiratory problems and the recognition of a new paediatric syndrome analogous to the diffuse oesophageal spasm syndrome of adulthood. It has been demonstrated that a routine, uncomplicated, paediatric scintigraphic examination, useful for investigating a wide range of problems in both a first and third world setting is possible for a nuclear medicine practitioner with normally available radiopharmaceuticals, equipment and radiographical expertise.
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Yang, Lin. "Physical activity in adults : investigating the contribution of active travel." Thesis, University of Cambridge, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.610782.
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Kuchapski, Kathryn A. "Effects of selenium and other surface coal mine influences on fish and invertebrates in Canadian Rockies streams." Thesis, Lethbridge, Alta. : University of Lethbridge, Dept. of Biological Sciences, c2013, 2013. http://hdl.handle.net/10133/3362.
Full textAbstract:
Physical and chemical influences downstream of surface coal mines, including
selenium (Se) release, water quality shifts, and habitat alterations can affect aquatic
organisms. To evaluate these influences at the community level of organization, fish and
macroinvertebrates were studied in mine-affected and reference streams. Se can be toxic
to aquatic organisms and was measured in lotic food chains (water, biofilm,
macroinvertebrates and juvenile salmonids). Invertebrate Se was significantly related to
Se in juvenile fish muscle (westslope cutthroat, bull, rainbow and brook trout) and Se
concentrations exceeded proposed individual-level reproductive effects thresholds in
some rainbow and cutthroat trout. Community-level effects were only detected in
rainbow trout where species specific biomass was negatively related to muscle Se
concentration in stream reaches. Macroinvertebrate assemblages varied along a mineinfluence
gradient defined by Se, alkalinity, substrate embeddedness and interstitial
material size. Ephemeroptera were the most sensitive to mining effects and potential
mechanisms influencing community composition included Se and ion toxicity and habitat
degradation. This project highlights the need to study multiple organisms at different
levels of ecological organization in order to understand and manage diverse mining
impacts.xi, 108 leaves : col. maps ; 29 cm
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Roberts, Keith McMillan. "Intakes of selenium and calcium are inversely correlated with incidence of colorectal cancer| National Health and Nutrition Examination Survey (NHANES) 1999-2014." Thesis, California State University, Long Beach, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10118893.
Full textAbstract:
Diet is a modifiable risk factor that strongly influences colorectal cancer (CRC) risk. Previous studies have associated CRC with impaired nutrient intakes including calcium, selenium and folate intakes. This study sought to investigate relationships between calcium, selenium and folate intakes and CRC. Calcium, selenium, and folate intakes and incidence of CRC from a selected cohort within the National Health and Nutrition Examination Survey (NHANES) 1999–2014 were analyzed. A total of 2,130 men and women aged 31 to 85 with and without CRC were included in the analysis. The relationships between daily intakes of calcium, selenium and folate and CRC incidence were analyzed using χ2 test and logistic regression. Correlations between calcium, selenium and folate intakes and CRC were also assessed using Pearson’s correlation coefficient.
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Catena, Rodolfo. "Essays on health care operations management." Thesis, University of Oxford, 2015. http://ora.ox.ac.uk/objects/uuid:3c2035a6-b5d0-43b7-9b12-4883e5db4526.
Full textAbstract:
The aim of operations management in health care is to enhance the provision of services to patients and to decrease costs. Overall worldwide health care expenditures represent around 10.5% of the global GDP and are projected to increase at an annual rate of 5.3% from 2015 to 2017 [74]. In order to investigate how to curb health care costs, I study the English NHS, a health care system that provided universal care to around 54 million people in 2014 [243]. The NHS has launched many initiatives to improve the performance of hospital operations such as the "QIPP" program, which has the objective to save £20 billion of costs by 2015 [98]. Given this framework, this research aims to contribute to the theory that is guiding these operational changes, using data on all admissions to hospitals and focussing on the inguinal hernia, one of the most common surgical procedures [86]. In the next chapters, this research describes inguinal hernia care delivery in the English NHS, examines the impact of spillovers and complementarities on costs, and investigates the effects of length of stay reduction on risk of re-admission and risk of death. The findings of this thesis indicate that one of the possible problems in the delivery of inguinal hernia care in the NHS is the decrease in the number of elective operations performed and the increase in readmission rates. They also clarify how decisions on allocation of resources can affect hospital expenditures by showing that loss in focus can increase health care costs and by pointing out that there is little evidence to support the theory of spillovers and complementarities in the surgical context. Finally, the results of this research can be used to suggest the logic of a policy to decrease length of stay that can inform hospital decisions and can decrease hospital costs.
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Dominguez, Socorro Escandon. "Temporal aspects of Mexican American intergenerational caregiving." Diss., The University of Arizona, 2004. http://hdl.handle.net/10150/280544.
Full textAbstract:
Problem and background. Caregiving for elderly family members can be viewed as a part of and extension of supportive behaviors between individuals. Consequently, there are cultural undertones to caregiving and what is supportive in one culture may not be in another. Mexican American caregiving has not been well studied; however, Mexican Americans are reported to be more likely to use family as resource for solving problems than non-Hispanic whites. Purpose. Guided by caregiving framework developed by Bowers (1987), Wilson (1989) and Nolan et al. (1995, 1996, & 1997) this study employed grounded theory to formulate a conceptual model of intergenerational caregiving among Mexican American families focusing on characteristics of the temporal axis which defines caregiving in terms of (1) family structure or generational attitudes (historical time); (2) what and how shared understandings with elders and among family members influence who assumes the caregiver role and when (kin time); (3) how entry into the caregiving role affects the entire family (intergenerational development time); and (4) how entry into the caregiving role affects the caregivers' peer relationships (peer time). This study also builds theory about how acculturation influences family care giving. Design, methods. This exploratory study was guided by grounded theory methodology where interviews were taped and analyzed using grounded theory's constant comparative method of analysis. Sample. The sample consisted of Mexican American caregivers (n = 10) of various generations over the age of 21 who provided at lest one intermittent service (without pay at least once a month) to an elder, related through consanguinal or acquired kinship ties. Results. Grounded theory of Role Acceptance comprised of four phases: (1) Introduction: Early Caregiving Experiences; (2) Role Reconciliation; (3) Role Imprint; and (4) Providing/Projecting Care. Significance. This study provides a Mexican American intergenerational caregiving model that can be utilized to study varied generations of Mexican American caregivers. It also provides a framework for comparison with other groups of caregivers. Results of this study also inform health professionals about ways in which Mexican American caregivers view caregiving. This information has potential to increase cultural competence in delivery of health care to elders and their families.