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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.
51

Effects of iron and omega-3 supplementation on the immune system of iron deficient children in South Africa : a randomised controlled trial / Linda Malan

Malan, Linda January 2014 (has links)
Background Iron deficiency (ID) is the world‟s most prevalent micronutrient deficiency and predominantly affects developing countries, also South Africa. In areas with low fish consumption and high n-6 PUFA vegetable oil intake, there is a risk for having inadequate n-3 PUFA status. Both iron and n-3 PUFA play important roles in the immune response, and supplementation is a strategy to alleviate deficiencies. However, little is known about potential interactive effects between concurrent iron and n-3 PUFA supplementation on the immune system. This is also important in the context that iron supplementation may be unsafe and may increase morbidity and mortality. Aim The overall aim of this thesis was to assess the effects of iron and docosahexaenoic (DHA)/eicosapentaenoic acid (EPA) supplementation, alone and in combination, on the immune system of ID children. More specifically, these effects were investigated on the occurrence and duration of illness and school-absenteeism due to illness, peripheral blood mononuclear cell (PBMC), red blood cell (RBC) and plasma total phospholipid fatty acid composition, iron status, fatty acid-derived immune modulators and targeted PBMC gene expression. Furthermore, association of PBMC, RBC and plasma total phospholipid fatty acid composition with allergic disease, were also examined. Design In a 2-by-2 factorial, randomised, double-blind, placebo-controlled trial, South African children (n = 321, aged 6–11 y) were randomly assigned to receive oral supplements of either 1) iron (50 mg as ferrous sulphate) plus placebo; 2) DHA/EPA (420/80 mg) plus placebo; 3) iron plus DHA/EPA (420/80 mg); or 4) placebo plus placebo for 8.5 mo, four times per week. Absenteeism and illness symptoms were recorded and biochemical parameters for compliance as well as parameters fundamental to immune function were assessed at baseline and endpoint. Furthermore, in a cross-sectional design, associations of allergic disease with baseline fatty acid composition of PBMC, RBC and plasma were examined. Results The combination of iron and DHA/EPA significantly attenuated respiratory illness caused by iron supplementation. DHA/EPA supplementation alone improved respiratory symptoms at school, but increased headache-related absenteeism. DHA/EPA and iron supplementation individually tended to increase and decrease anti-inflammatory DHA and EPA-derived mediators, respectively. Furthermore the anti-inflammatory DHA-derived immune mediator, 17HDHA was higher in the DHA/EPA plus placebo and iron plus DHA/EPA groups than in the iron plus placebo group. Also, the pro-inflammatory arachidonic acid (AA)-derived modulators (5- and 15-hydroxyeicosapentaenoic acid) were significantly lower in the iron plus DHA/EPA group compared to the placebo plus placebo groups. In the study population, 27.2% of the children had allergic disease and AA in PBMC phospholipids was significantly lower in the allergic children than in the non-allergic children. In RBC phospholipids dihomo-gamma-linolenic acid (DGLA) and the ratio of DGLA: linoleic acid (LA) correlated negatively and the n-6:n-3 PUFA ratio positively with total immunoglobulin E (tIgE). Furthermore, trans-C18:1n-9, tended to be higher in the allergic group. Conclusion DHA/EPA prevented respiratory illness caused by iron supplementation and although DHA/EPA on its own reduced respiratory morbidity when the children were present at school, surprisingly it increased the likelihood of being absent with headache and fever. The biochemical findings compliment the clinical results and support previous observations about DHA/EPA supplementation to reduce inflammation, but add to the current knowledge base that a relatively high oral dose of non-haem iron modulates circulating lipid-derived immune modulators and related gene expression. Furthermore, when supplementing with iron and DHA/EPA combined, in this ID population with low fish intake, the anti-inflammatory effect of DHA/EPA is maintained concurrently with attenuation of respiratory morbidity. This finding support the notion that excess iron (probably as non-transferrin bound iron) becomes available for pathogens and is probably why we found that iron increased respiratory infectious morbidity. The improved clinical outcome with combined supplementation seems to be related to increased lipid-mediator synthesis gene expression and the availability of DHA/EPA, leading to a more pro-resolving profile and enhanced immune competence. Overall these results give better insight into immune function and infectious morbidity in relation to n-3 PUFA and iron status and treatment, as well as the possible association of fatty acid status with allergic disease in young South-African school children. / PhD (Nutrition), North-West University, Potchefstroom Campus, 2015
52

Effects of iron and omega-3 supplementation on the immune system of iron deficient children in South Africa : a randomised controlled trial / Linda Malan

Malan, Linda January 2014 (has links)
Background Iron deficiency (ID) is the world‟s most prevalent micronutrient deficiency and predominantly affects developing countries, also South Africa. In areas with low fish consumption and high n-6 PUFA vegetable oil intake, there is a risk for having inadequate n-3 PUFA status. Both iron and n-3 PUFA play important roles in the immune response, and supplementation is a strategy to alleviate deficiencies. However, little is known about potential interactive effects between concurrent iron and n-3 PUFA supplementation on the immune system. This is also important in the context that iron supplementation may be unsafe and may increase morbidity and mortality. Aim The overall aim of this thesis was to assess the effects of iron and docosahexaenoic (DHA)/eicosapentaenoic acid (EPA) supplementation, alone and in combination, on the immune system of ID children. More specifically, these effects were investigated on the occurrence and duration of illness and school-absenteeism due to illness, peripheral blood mononuclear cell (PBMC), red blood cell (RBC) and plasma total phospholipid fatty acid composition, iron status, fatty acid-derived immune modulators and targeted PBMC gene expression. Furthermore, association of PBMC, RBC and plasma total phospholipid fatty acid composition with allergic disease, were also examined. Design In a 2-by-2 factorial, randomised, double-blind, placebo-controlled trial, South African children (n = 321, aged 6–11 y) were randomly assigned to receive oral supplements of either 1) iron (50 mg as ferrous sulphate) plus placebo; 2) DHA/EPA (420/80 mg) plus placebo; 3) iron plus DHA/EPA (420/80 mg); or 4) placebo plus placebo for 8.5 mo, four times per week. Absenteeism and illness symptoms were recorded and biochemical parameters for compliance as well as parameters fundamental to immune function were assessed at baseline and endpoint. Furthermore, in a cross-sectional design, associations of allergic disease with baseline fatty acid composition of PBMC, RBC and plasma were examined. Results The combination of iron and DHA/EPA significantly attenuated respiratory illness caused by iron supplementation. DHA/EPA supplementation alone improved respiratory symptoms at school, but increased headache-related absenteeism. DHA/EPA and iron supplementation individually tended to increase and decrease anti-inflammatory DHA and EPA-derived mediators, respectively. Furthermore the anti-inflammatory DHA-derived immune mediator, 17HDHA was higher in the DHA/EPA plus placebo and iron plus DHA/EPA groups than in the iron plus placebo group. Also, the pro-inflammatory arachidonic acid (AA)-derived modulators (5- and 15-hydroxyeicosapentaenoic acid) were significantly lower in the iron plus DHA/EPA group compared to the placebo plus placebo groups. In the study population, 27.2% of the children had allergic disease and AA in PBMC phospholipids was significantly lower in the allergic children than in the non-allergic children. In RBC phospholipids dihomo-gamma-linolenic acid (DGLA) and the ratio of DGLA: linoleic acid (LA) correlated negatively and the n-6:n-3 PUFA ratio positively with total immunoglobulin E (tIgE). Furthermore, trans-C18:1n-9, tended to be higher in the allergic group. Conclusion DHA/EPA prevented respiratory illness caused by iron supplementation and although DHA/EPA on its own reduced respiratory morbidity when the children were present at school, surprisingly it increased the likelihood of being absent with headache and fever. The biochemical findings compliment the clinical results and support previous observations about DHA/EPA supplementation to reduce inflammation, but add to the current knowledge base that a relatively high oral dose of non-haem iron modulates circulating lipid-derived immune modulators and related gene expression. Furthermore, when supplementing with iron and DHA/EPA combined, in this ID population with low fish intake, the anti-inflammatory effect of DHA/EPA is maintained concurrently with attenuation of respiratory morbidity. This finding support the notion that excess iron (probably as non-transferrin bound iron) becomes available for pathogens and is probably why we found that iron increased respiratory infectious morbidity. The improved clinical outcome with combined supplementation seems to be related to increased lipid-mediator synthesis gene expression and the availability of DHA/EPA, leading to a more pro-resolving profile and enhanced immune competence. Overall these results give better insight into immune function and infectious morbidity in relation to n-3 PUFA and iron status and treatment, as well as the possible association of fatty acid status with allergic disease in young South-African school children. / PhD (Nutrition), North-West University, Potchefstroom Campus, 2015
53

INTELLECTUAL PROPERTY, TRADITIONAL KNOWLEDGE AND BIODIVERSITY IN THE GLOBAL ECONOMY: THE POTENTIAL OF GEOGRAPHICAL INDICATIONS FOR PROTECTING TRADITIONAL KNOWLEDGE-BASED AGRICULTURAL PRODUCTS

Dagne, Teshager Worku 01 March 2012 (has links)
The relationship between international regimes regulating intellectual property, traditional knowledge and biodiversity has received much attention in recent times. Of the many complex and controversial issues in contemporary international legal discourse on this matter, the protection of traditional knowledge (TK) stands out as a significant challenge. Choices abound in the search for modalities to regulate rights to use and control TK systems and their underlying biodiversity. In recent times, the protection of geographical indications (GIs) has emerged as an option for protecting TK. Despite the considerable enthusiasm over it, there is appreciable research dearth on how far and in what context GIs can be used as a protection model. Indeed, not only is the concept of GIs itself widely misunderstood. As well, analyses as to their applicability for protecting TK often reflect underlying cultural differences in the nature, scope and the jurisprudence regarding GIs across jurisdictions. This thesis examines the relationship between GIs and TK, focusing on the responsiveness of GIs to the needs and desires of indigenous peoples and local communities (ILCs). The thesis posits that the search for a model to protect TK should involve identifying different modalities, including those based on intellectual property, to fit to the nature and uses of TK in particular contexts. The analysis conceptualizes GIs as a form of IP that are structurally and functionally suitable to protect aspects of TK in traditional knowledge-based agricultural products (TKBAPs). Substantively, the thesis draws attention to the conceptual underpinnings of GIs as encompassing cultural and economic objectives in the protection of TK. As such, it is argued that stronger protection of GIs should be achieved by integrating the negotiations and discussion concerning GIs and TK at the international level. Further, the case is made for the determination of immediate challenges and long-term opportunities in choosing a legal means for protecting GIs at the national level. In this connection, the thesis suggests that the potential of GIs to meet national and local imperatives to protect TK be assessed, inter alia, based on their instrumentality for economic, biodiversity, cultural and food security objectives in protecting TKBAPs.
54

Le Ventre des Belges: miracle économique et restauration des forces de travail :origines et développement de la politique alimentaire du second immédiat après-guerre, 1914-1948 / Belly of Belgium: economic miracle and restoration of labour force :origin and development of second immediate postwar food policy, 1914-1948

Bernardo Y Garcia, Luis Angel 01 July 2015 (has links)
Au cours du second immédiat après-guerre, la Belgique continue être soumise à une « économie de disette » qui s’est épanouie sous la seconde occupation. Afin d’assurer le ravitaillement alimentaire de la population et le maintien d’une activité économique, la puissance publique est contrainte d’organiser l’économie nationale traditionnellement acquise à la liberté du marché. Le temps de la pénurie alimentaire mondiale, la politique alimentaire va diriger l’approvisionnement général du pays par la stabilisation des prix et salaires, les importations, la mobilisation du secteur alimentaire, la distribution de l’alimentation, le rationnement et enfin la répression du « marché noir ». En dépit de la cherté des approvisionnements extérieurs et la régulation de la pénurie au niveau mondial, les gouvernements belges qui se succèdent depuis la Libération s’attachent à l’amélioration du niveau de vie d’une population affaiblie par l’occupation. Cette restauration des forces de travail est un corollaire indispensable à la reprise de l’activité économique et à la reconstruction du pays mais aussi au maintien de l’ordre établi et à la restauration politique. Cet objectif alimentaire a été assigné en exil et dans Bruxelles occupée par les élites dirigeantes – qu’elles soient politiques, économiques ou syndicales – dans une rare unanimité au même titre que la défense d’un « franc fort ». Le Parti communiste, qui participe au pouvoir dès le premier Gouvernement d’Union nationale de la Libération, va aussi adhérer à ces deux objectifs et se voit attribuer le lourd et ingrat portefeuille du Ravitaillement pendant la plus grande partie de son existence qui s’étale de septembre 1944 à décembre 1948. <p><p>Le choix assumé par une Belgique solvable d’une « politique d’abondance » aux dépens d’une planification des investissements se démarque des choix opérés par la France, les Pays-Bas ou la Grande-Bretagne impécunieux mais obsédés par la modernisation de leurs appareils de production respectifs. L’objectif belge d’apporter à la population – à coup de subventions massives – l’indispensable puis l’utile mais aussi le superflu va se maintenir jusqu’à la libération progressive des transactions et des prix et participe à la restauration rapide de l’économie belge transformatrice et exportatrice. Dès la fin de la guerre en Europe, un apparent « miracle économique » se produit en Belgique avec la reprise rapide des exportations à destination des pays limitrophes. Le processus de restauration économique a été initié dès les premières semaines de la Libération grâce aux prestations massives aux armées alliées et le « remboursement » inespéré d’une partie conséquente de celles-ci après-guerre. Dès le début de l’année 1947, la production industrielle belge rattrape le niveau d’avant-guerre alors que les productions charbonnière et agricole restent à la traîne. La politique alimentaire du second immédiat après-guerre place le consommateur au centre de l’économie agricole et multiple les contraintes du côté de l’offre en matière de transactions et de prix. Encombrée par l’héritage de l’occupation – en dépit d’un droit d’inventaire – elle rencontrera une forte opposition de la part du secteur alimentaire et principalement le monde agricole et le petit commerce. Ceux-ci déploieront des stratégies défensives à la fois politiques et illégales. Ces dernières s’expriment essentiellement depuis l’occupation par le détournement d’une part conséquente des maigres disponibilités alimentaires au profit de l’ennemi et d’une minorité au fort pouvoir d’achat. Quant au monde ouvrier organisé qui constitue aux yeux de la puissance publique le principal acteur du côté de la demande alimentaire, il va contester dès la Libération la politique d’austérité et l’inéquité des sacrifices demandés au nom de la restauration du pays. En dépit d’une pacification convenue entre les élites patronales et syndicales en échange de réformes sociales et la participation loyale des communistes au pouvoir, la seconde sortie de guerre sera marquée par de nombreuses grèves « sauvages » débordant le cadre syndical réformiste et communiste.<p><p>À vrai dire, la politique alimentaire mise en œuvre au cours de la seconde libération et du second immédiat après-guerre – ainsi que les réponses apportées par l’offre et la demande – ne peuvent être étudiées et comprises qu’en convoquant les crises alimentaires précédentes depuis la première occupation que la Belgique fut la seule à connaître en Europe occidentale sur la plus grand partie de son territoire, à l’exception du petit voisin grand-ducal. Tant la puissance publique, les élites dirigeantes que le monde agricole ou encore le mouvement ouvrier sauront tirer les enseignements des expériences passées. Enfin, la production agricole de la Belgique structurellement dépendante des importations massives de céréales et autres aliments du bétail s’inscrit depuis la fin du XIXème siècle dans une économie alimentaire mondialisée. Les crises alimentaires des temps de (sortie de guerre) traversées par la petite économie transformatrice et exportatrice sont avant tout des crises des approvisionnements extérieurs marquées par leur diminution voire leur quasi disparition. Au cours du second immédiat après-guerre, la politique alimentaire de la Belgique – comme celle des autres grands pays importateurs français, britannique ou néerlandais – sera toujours aussi tributaire des approvisionnements extérieurs régulés depuis la guerre par les Grands Alliés anglo-saxons. Ceux-ci passeront le relais en 1946 aux organismes internationaux gravitant autour des Nations Unies jusqu’aux abondantes récoltes mondiales de l’An 1948. / Doctorat en Histoire, art et archéologie / info:eu-repo/semantics/nonPublished
55

Evapotranspiração e coeficientes de cultivo (KC) da cana-de-açúcar irrigada por gotejamento subsuperficial / Evapotranspiration and crop coefficients of subsurface drip irrigated sugar cane

Gonçalves, Fabricio Mota January 2010 (has links)
GONÇALVES, Fabrício Mota. Evapotranspiração e coeficientes de cultivo (KC) da cana-de-açúcar irrigada por gotejamento subsuperficial. 2010. 64 f. : Dissertação (mestrado) - Universidade Federal do Ceará, Centro de Ciências Agrárias, Departamento de Engenharia Agrícola, Programa de Pós-Graduação em Engenharia Agrícola, Fortaleza-CE, 2010. / Submitted by demia Maia (demiamlm@gmail.com) on 2016-06-28T16:59:16Z No. of bitstreams: 1 2010_dis_fmgonçalves.pdf: 3900094 bytes, checksum: 1ad79acf1432c0de09bcbdf52cb0f8c3 (MD5) / Approved for entry into archive by demia Maia (demiamlm@gmail.com) on 2016-06-28T16:59:48Z (GMT) No. of bitstreams: 1 2010_dis_fmgonçalves.pdf: 3900094 bytes, checksum: 1ad79acf1432c0de09bcbdf52cb0f8c3 (MD5) / Made available in DSpace on 2016-06-28T16:59:48Z (GMT). No. of bitstreams: 1 2010_dis_fmgonçalves.pdf: 3900094 bytes, checksum: 1ad79acf1432c0de09bcbdf52cb0f8c3 (MD5) Previous issue date: 2010 / Sugar cane is one of the crops with the highest level of water consumption, with a high evapotranspiration demand throughout most of its cycle. Knowledge of the sugar cane water demand, the time that irrigation should be applied, and how to irrigate the crop are becoming increasingly important for the sustainable development of irrigated sugar cane cultivation, especially in areas of low water availability, as it is the case in northea stern Brazil. The experiment was carried out at the Curu Experimental Field (property of the Embrapa Tropical Agroindustry), located in the Curu-Paraipaba Irrig ation Project, city of Paraipaba-CE (3 ° 29 '20''S, 39 ° 9' 45''W and elevation 30m), in order to determine the evapotrans piration and crop coefficients (Kc) of sugarcane (Saccharum L. officinarium), subsurface drip-irrigated. It was used the SP 6949 sugar cane variety, planted in a spacing of 1.8 m between double rows and 0.4 m between rows within the double row. As to t he irrigation, we used one lateral water line for each double row, buried at a depth of 0.15 m, w ith self-compensating drip emitters, with a flow rate of 1 L h-1, spaced 0.5 m on the water line. The crop was irrigated daily and there were three fertigations per week. The irrigation de pth was periodically adjusted, keeping the soil water potential between -8 kPa to -20 kPa. The crop evapotranspiration (ETc) was determined using a wei ghing lysimeter with a surface area of 2.25 m 2. The reference evapotranspiration (ETo) was estimated by the FAO Penman-Monteith method. The durations of the phenological stages of cane sugar were estimated through analysis of soil cover, with the use of digital images. Durations of 31, 49, 237 and 118 days were observed, respectively for initial, crop development, mid-season and late season stages. The yields achieved within and outside the lysimeter were respectively 144.4 and 108.8 t ha -1 . The total ETc observed during the cycle of the sugar cane was 1074.1 m m, with maximum values of 6.6 mm d-1 during the mid-season stage. Observed Kc values for initial, mid-season and late season stages were respectively 0.23, 1 .03 and 0.50. In the crop development stage, the relationship between Kc and the (crop) soil cover was represented with good accuracy by a negative quadratic model. / A cana-de-açúcar é uma das culturas com maior consumo de água, apresentando uma alta demanda evapotranspirativa ao longo da maior parte do seu ciclo. O conhecimento das necessidades hídricas da cana-de-açúcar, do momento de aplicação da água requerida pela mesma e a forma de aplicação torna-se cada vez mais importante para o desenvolvimento sustentável da sua produção irrigada, principalmente em regiões de pouca disponibilidade hídrica, como é o caso da região Nordeste do Brasil. O experimento foi conduzido no Campo Experimental do Curu, pertencente à Embrapa Agroindústria Tropical localizado no Perímetro Irrigado Curu-Paraipaba, município de Paraipaba-CE (3° 29’ 20’’ S, 39° 9’ 45’’ W e altitude de 30 m), com o objetivo de determinar a evapotranspiração e os coeficientes de cultivo (Kc) da cana-de-açúcar (Saccharum officinarium L.), irrigada por gotejamento subsuperficial. Utilizou-se a variedade de cana SP 6949, plantada no espaçamento de 1,8 m entre fileiras duplas e 0,4 m entre linhas dentro da fileira dupla. Na irrigação utilizou-se uma linha lateral para cada fileira dupla, enterrada na profundidade de 0,15 m, com gotejadores autocompensantes, com vazão de 1 L h-1, espaçados de 0,5 m na linha. A cultura foi irrigada com freqüência diária e foram realizadas três fertirrigações por semana. A lâmina de irrigação foi ajustada periodicamente, mantendo-se o potencial de água no solo entre -8 kPa e -20 kPa. A evapotranspiração da cultura (ETc) foi determinada utilizando-se um lisímetro de pesagem com área superficial de 2,25 m2. A evapotranspiração de referência (ETo) foi estimada pelo método FAO Penman-Monteith. As durações das fases fenológicas da cana-de-açúcar foram estimadas por meio da análise da cobertura do solo pela cultura, determinada com o uso de imagens digitais. Foram observadas durações de 31, 49, 237 e 118 dias, para as fases inicial, de desenvolvimento, intermediária e final, respectivamente. A produtividade alcançada dentro e fora do lisímetro foi de 144,4 e 108,8 t ha-1, respectivamente. A ETc total observada durante o ciclo da cana-de-açúcar foi de 1.074,1 mm, com valores máximos da ordem de 6,6 mm d-1 durante a fase intermediária. Foram observados valores de Kc iguais a 0,23, 1,03 e 0,50, para as fases inicial, intermediária e final, respectivamente. Na fase de desenvolvimento vegetativo a relação entre o Kc e a cobertura do solo pela cultura foi representada com bastante exatidão por um modelo quadrático negativo.

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