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  • 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.
1

I vilken mängd intas D-vitamin? : En kvantitativ studie som undersöker rapporterat intag av D-vitamin i en internetbaserad enkätstudie. / Which amount of vitamin D is ingested? : A quantitative study examining reported intake of vitamin D in an internet-based survey.

Sara, Wikman January 2014 (has links)
Bakgrund. Kostens sammansättning får en stor betydelse för boende i Sverige då de inte tillgodogör sig D-vitamin från solen i samma utsträckning som länder vid ekvatorn, speciellt vintertid. Hela 80 % av den intagna mängden D-vitamin absorberas i tarmen, ändå visar forskning på att brist föreligger i större utsträckning bland boende över 55 breddgraden. Syfte. Studiens syfte var att undersöka hur troligt det är att boende i Sverige uppnår rekommenderat dagligt intag av D-vitamin. Metod. För att besvara syftet utfördes en internetbaserad kvantitativ studie, baserad på en frekvensenkät. Enkäten bestod av 28 frågor, varav åtta mätte intagsfrekvens av D-vitaminrika livsmedel. Urvalet baserades på ett bekvämlighetsurval. Kön, utbildningsnivå, hemort, utlandsvistelse, träning, kosttillskott- och solskyddsanvändning testades mot tre intagsgrupper baserad på intagen mängd D-vitamin med hjälp av Chit2-test. Vidare jämfördes deltagarnas intag mot EFSA´s gränsvärden. Resultat. Totalt inkom 144 enkätsvar av dessa rapporterade 93 % ett D-vitaminintag under rekommenderat dagligt intag (RDI). Beträffande livsmedel var lax, makrill, berikad lätt-/mellanmjölk och ägg de främsta källorna till deltagarnas uppskattade D-vitaminintag. Det var 21 % av respondenter som rapporterade ett intag under lower intake level (LI). Vidare rapporterade 32 % av respondenterna ett intag mellan LI och average requirement (AR). En mindre andel av respondenterna (n=20) hade varit utomlands under efterfrågad period. Majoriteten av respondenterna sågs använda solskyddsmedel, var aktiva och upplevde sig ha en god hälsa. Slutsats. Det beräknades föreligga en 53-% risk att någon av deltagarna hade ett inadekvat D-vitaminintag. Ett fåtal deltagare (n=10) beräknades inta D-vitamin i enlighet med RDI. / Background. The diet is of a great importance for residents in Sweden, since they do not assimilate vitamin D from the sun to the same extent as people living in countries located at the equator. The intestine absorbs as much as 80 % of the vitamin-D intake; nevertheless the insufficiency is more common among countries above the 55 latitude. Aim. The study aimed to investigate how likely it is that people in Sweden achieves the recommended daily intake of vitamin D. Method. To answer the question a quantitative study approach was chosen based on a non-random selection. Frequency questionnaire consisted of a total of 28 questions; eight measured the intake frequency of D- vitamin in food. Gender, education, place of residence, educational, training, food supplements and sun block use were tested against three intake groups based on vitamin D intake with Chit2 test. Later on participants' intake was compared with the limits of EFSA. Results. A total of 144 responded the survey, 93% of these reported a D-vitamin intake below the recommended daily intake (RDI). Food such as, salmon, mackerel, enriched easy- /semi-skimmed milk and eggs were principal sources of the participants' estimated D-vitamin intake. It was 21 % of respondents who reported an intake below lower intake level (LI). Furthermore, 32% of the respondents reported an intake between LI and average requirement (AR). A smaller proportion of the respondents (n= 20) had been abroad during requested period. The majority of the respondents were seen using sun block, was active and experienced to have a good health. Conclusion. It might be a 53-% risks that participants have an inadequate D-vitamin intake. A small number of participants (n= 10) estimate a vitamin D intake in accordance with RDI.
2

Metabolismo visceral em ovinos: custo energético associado ao nível de consumo e ao metabolismo hepático de compostos nitrogenados / Splanchnic metabolism in sheep: energetic costs associated to feed intake level and hepatic metabolism of nitrogenous compounds

Hentz, Fernanda 26 August 2013 (has links)
Conselho Nacional de Desenvolvimento Científico e Tecnológico / The effect of level of forage intake on blood flow and oxygen consumption (Experiment 1), and mesenteric infusion of ammonium bicarbonate (NH4HCO3), L-alanine or L-arginine on oxygen consumption and net flux of metabolites (Experiment 2) through the splanchnic (portal-drained viscera [PDV] plus liver (ST)) tissues were evaluated in sheep surgically implanted with chronic indwelling catheters into the mesenteric, portal and hepatic veins. In both experiments, blood flow was estimated by downstream dilution of p-aminohippurate. In experiment 1, three adult male Polwarth wethers (42±4.4 kg body weight (BW)), housed in metabolism cages and offered Tifton (Cynodon sp.) hay were used in a 3 x 3 Latin Square design. Treatments consisted of hay allowances of 7, 14 or 21 g dry matter (DM)/kg BW/day, offered in four equal daily meals, every 6 h. Blood flow across PDV was linearly (P<0.05) related to OM intake, whereas the hepatic-arterial and total ST blood flow were no affected. Oxygen expenditure by PDV was directly (P<0.05) related to OM intake, while oxygen consumption by the liver was not affected. Oxygen expenditure was linearly (P<0.05) related to blood flow across tissues for PDV, liver and total ST. The proportion of metabolizable energy (ME) intake spent as heat by PDV and total ST reduced when ME intake increased. In addition, this reduction occurred in a curvilinear manner as the difference between PDV and ST heat production reduced at increased ME intake. In experiment 2, four multicatheterized Polwarth wethers (40 ± 3.8 kg BW) fed 14 g DM of oat (Avena sativa) plus ryegrass (Lolium multiflorum Lam) hay/kg BW/day of Tifton hay were used in a 4 x 4 Latin Square design. Treatments were mesenteric vein infusion of 500 μL/min of saline solution (control) or a solution containing NH4HCO3, L-alanine or L-arginine. The net flux of glucose and urea through PDV and ST were not affected by treatments. Portal appearance and liver removal of N-NH3 were higher (P<0.05) with the NH4HCO3 infusion. The PDV and ST net flux of oxygen were not affected by treatments, whereas the hepatic oxygen consumption was higher in control treatment (P<0.05). The hypothesis that ureagenesis and/or gluconeogenesis increases hepatic energy spenditure was not observed in the present study. Methodological aspects are included in results discussion. / Foi avaliado o efeito do nível de consumo de forragem sobre o fluxo de sangue e utilização de O2 (Experimento 1), e da infusão mesentérica de bicarbonato de amônio (NH4HCO3), L-alanina ou L-arginina (Experimento 2) sobre a utilização de O2 e fluxo de metabólitos pelo sistema visceral (tecidos drenados pela veia porta (TDVP) e o fígado) em ovinos implantados cirurgicamente com catéteres permanentes nas veias mesentérica, porta e hepática. Em ambos experimentos o fluxo de sangue foi estimado pela técnica de diluição de p-aminohipurato. No experimento 1, três ovinos machos da raça Polwarth (42±4.4 kg de peso corporal (PC), alojados em gaiolas de metabolismo e alimentados com feno de Tifton (Cynodon sp.) foram utilizados em um delineamento Quadrado Latino 3 x 3. O feno foi oferecido nas quantidades de 7, 14 ou 21 g matéria seca (MS)/dia/kg de PC em quatro porções diárias iguais, a cada 6 h. O fluxo de sangue nos TDVP aumentou linearmente (P<0,05), mas o fluxo de sangue hepático-arterial e visceral total não foram afetados pelo aumento no consumo de forragem. O gasto de O2 pelos TDVP foi positivamente (P<0,05) relacionado com o consumo de matéria orgânica (MO). O gasto de O2 relacionou-se linearmente com o fluxo de sangue (P<0,05) nos TDVP, fígado e sistema visceral. A proporção de energia metabolizável (EM) consumida gasta como calor pelos TDVP e fígado diminuiu com o aumento no consumo de EM de forma curvilinear, sendo que a diferença entre a produção de calor visceral e dos TDVP reduziu com o aumento no consumo de EM. No experimento 2, quatro ovinos Corriedale (40 ± 3.8 kg PC), implantados com catéteres permanentes nas veias mesentérica, porta e hepática, alimentados com 14 g MS de feno de aveia (Avena sativa) e azevém (Lolium multiflorum Lam)/dia/kg de PC, foram utilizados em um delineamento Quadrado Latino 4 x 4. Os tratamentos consistiram da infusão na veia mesentérica de 500 μL/min de solução salina (controle) ou de uma solução contendo NH4HCO3, L-alanina ou L-arginina. Os fluxos portal e visceral total líquido de glicose e N-uréia não foram afetados significativamente pelos tratamentos. O fluxo de O2 pelos TDVP não diferiu entre tratamentos. Contudo, houve maior (P<0,05) gasto de O2 pelo fígado no tratamento controle. A hipótese de que a ureagênese e/ou a neoglicogênese impactam o gasto de energia pelo fígado não foi comprovada no presente estudo. Aspectos metodológicos são considerados na discussão destes resultados.
3

Physcial hydraulic model investigation of critical submergence for raised pump intakes

Kleynhans, S. H. 03 1900 (has links)
Thesis (MScEng)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: Various design guidelines have been published over the past four decades to calculate the minimum submergence required at pump intakes to prevent vortex formation. These design guidelines also require the suction bell to be located not higher than 0.5 times the suction bell diameter (D) above the floor. Sand trap canals are an integral part of large river abstraction works, with the pump intakes located at the end of the sand trap canals. The canals need to be flushed by opening a gate, typically 1.5 m high, that is located downstream of the pump intake. This requires the suction bell be raised to not interfere with the flushing operation, which leads to the question – what impact does the raising of the suction bell have on the minimum required submergence? A physical hydraulic model constructed at 1:10 scale was used to determine the submergence required to prevent types 2, 5 and 6 vortices for prototype suction bell inlet velocities ranging from 0.9 m/s to 2.4 m/s, and for suction bells located at 0.5D, 1.0D and 1.5D above the floor. The tests were undertaken for four suction bell configurations with a conventional flat bottom suction bell, fitted with a long radius bend, being the preferred suction bell configuration in terms of the lowest required submergence levels. The experimental test results of the preferred suction bell configuration were compared against the published design guidelines to determine which published formula best represents the experimental test results for raised pump intakes. It became evident from the experimental test results that the required submergence increased markedly when the suction bell was raised higher than a certain level above the floor. It was concluded that this “discontinuity” in the required submergence occurred for all the suction bell configuration types when the ratio between the prototype bell inlet velocity and the approach canal velocity was approximately 6.0 or higher. It is recommended that, for pump intakes with a similar geometry to that tested with the physical hydraulic model, critical submergence is calculated using the equation published by Knauss (1987), i.e. S = D(0.5 + 2.0Fr), if the prototype bell inlet velocity/approach canal velocity ratio is less than 6.0, and that the equation published by the Hydraulic Institute (1998), i.e. S = D(1 + 2.3Fr), can be used where the ratio, as determined with Knauss’ (1987) equation, exceeds 6.0. It is also recommended that prototype bell inlet velocities be limited to 1.5 m/s. / AFRIKAANSE OPSOMMING: Oor die afgelope vier dekades is verskeie ontwerpriglyne vir die berekening van minimum watervlakke, om werwelvorming by pompinlate te voorkom, gepubliseer. Hierdie ontwerpriglyne vereis dat die klokmond van die pompinlaat nie hoër as 0.5 keer die deursnee van die klokmond (D) bokant die kanaalvloer geleë moet wees nie. Sandvang kanale vorm ‘n integrale deel van groot riveronttrekkingswerke, met pompinlate wat aan die einde van hierdie kanale geleë is. Die kanale word aan die stroomaf kant van die pompinlaat voorsien met sluise sodat die kanale gespoel kan word. Hierdie sluise is tipies 1.5 m hoog. Dit is derhalwe nodig om die hoogte onder die klokmond dieselfde te maak as die hoogte van die sluis sodat die klokmond die spoelwerking nie beïnvloed nie. Die vraag is egter – wat is die impak op die minimum vereiste watervlakke indien die klokmond op ‘n hoër vlak installeer word? ‘n Fisiese hidrouliese model met ‘n 1:10 skaal is gebruik om die minimum watervlakke te bepaal waar tipes 2, 5 en 6 werwels aangetref word vir prototipe inlaatsnelhede van 0.9 m/s tot 2.4 m/s en klokmond hoogtes van 0.5D, 1.0D en 1.5D bokant die kanaalvloer. Vier klokmond konfigurasies is getoets. Die minimum vereiste watervlakke was die laagste vir die tradisionele plat klokmond met ‘n lang radius buigstuk en was dus die voorkeur klokmond. Die eksperimenttoetsresultate vir die voorkeur klokmond is met die gepubliseerde ontwerpriglyne vergelyk om te bepaal watter van die ontwerpsriglyne van toepassing sal wees vir verhoogde klokmond installasies. Uit die eksperimenttoetsresultate is dit duidelik dat die vereiste watervlakke skielik verhoog sodra die klokmond installasie ‘n seker hoogte bokant die kanaal vloer oorskry. Daar is bevind dat hierdie verskynsel by al vier klokmond konfigurasies voorkom sodra die verhouding tussen die prototipe klokmond inlaatsnelheid teenoor die snelheid in die kanaal hoër as 6.0 is. Daar word aanbeveel dat die minimum vereiste watervlak vir pompinlate met dieselfde geometrie as die fisiese model, met Knauss (1987) se vergelyking bereken word, naamlik S = D(0.5 + 2.0Fr), waar die snelheidsverhouding tussen die klokmond en kanaal 6.0 nie oorskry nie, en dat die vergelyking gepubliseer deur die Hydraulic Institute (1998), S = D(1 + 2.3Fr), gebruik word waar die snelheidsverhouding 6.0, so bereken met Knauss (1987) ser vergelyking, wel oorskry. Die prototipe klokmond inlaatsnelheid moet ook beperk word tot 1.5 m/s.
4

An Examination of the Population Health Implications of Voluntary Food Fortification and Nutrition-related Marketing Practices in Canada.

Sacco, Jocelyn 19 December 2012 (has links)
The 2004 Canadian Community Health Survey (CCHS) revealed many indicators of poor diet quality in Canada which, together with the high rates of obesity and diet-related chronic disease, suggest that shifts in dietary patterns are urgently needed. Given the widespread promotion of foods on the basis of nutrition and health, the aim of this work was to explore the population health implications of voluntary food fortification and nutrition-related marketing in Canada. Using the CCHS, the potential impact of a proposed discretionary food fortification policy on nutrient inadequacies and excesses was examined, in addition to the relationship between consumption of foods eligible to be fortified under this policy and indicators of dietary quality. To better understand the potential risk associated with liberal fortification practices, the National Health and Nutrition Examination Survey (2007-08) was used to examine potential for risk of excess associated with voluntarily fortified food consumption in the US, where these practices have long been permitted. The results suggest that proposed changes to voluntary fortification may reduce inadequacy and increase excess, and may reinforce poor diet patterns. Excessive nutrient intakes were also found to be associated with consumption of voluntarily fortified foods in the US, particularly among children. Therefore, there appears to be real potential for risk associated with voluntary fortification practices in Canada. The extent, nature, and population health implications of nutrition marketing in Canada was examined, using a survey of front-of-package nutrition-related marketing on foods within three large grocery stores in Toronto. Nutrition-related marketing was found on 41% of all foods surveyed, and was widely found on highly processed, often fortified foods. References to nutrients of public health concern (e.g. sodium, vitamin D) were infrequently found. Overall, this practice provides limited nutritional guidance. Current directions in nutrition policy in Canada should be re-evaluated, to ensure that they support healthy diet patterns.
5

An Examination of the Population Health Implications of Voluntary Food Fortification and Nutrition-related Marketing Practices in Canada.

Sacco, Jocelyn 19 December 2012 (has links)
The 2004 Canadian Community Health Survey (CCHS) revealed many indicators of poor diet quality in Canada which, together with the high rates of obesity and diet-related chronic disease, suggest that shifts in dietary patterns are urgently needed. Given the widespread promotion of foods on the basis of nutrition and health, the aim of this work was to explore the population health implications of voluntary food fortification and nutrition-related marketing in Canada. Using the CCHS, the potential impact of a proposed discretionary food fortification policy on nutrient inadequacies and excesses was examined, in addition to the relationship between consumption of foods eligible to be fortified under this policy and indicators of dietary quality. To better understand the potential risk associated with liberal fortification practices, the National Health and Nutrition Examination Survey (2007-08) was used to examine potential for risk of excess associated with voluntarily fortified food consumption in the US, where these practices have long been permitted. The results suggest that proposed changes to voluntary fortification may reduce inadequacy and increase excess, and may reinforce poor diet patterns. Excessive nutrient intakes were also found to be associated with consumption of voluntarily fortified foods in the US, particularly among children. Therefore, there appears to be real potential for risk associated with voluntary fortification practices in Canada. The extent, nature, and population health implications of nutrition marketing in Canada was examined, using a survey of front-of-package nutrition-related marketing on foods within three large grocery stores in Toronto. Nutrition-related marketing was found on 41% of all foods surveyed, and was widely found on highly processed, often fortified foods. References to nutrients of public health concern (e.g. sodium, vitamin D) were infrequently found. Overall, this practice provides limited nutritional guidance. Current directions in nutrition policy in Canada should be re-evaluated, to ensure that they support healthy diet patterns.

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