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Wang, Jun. "Encapsulation of DHA oil as Pickering emulsion : effect on DHA bioaccessibility and metabolism." Thesis, Rennes, Agrocampus Ouest, 2022. https://tel.archives-ouvertes.fr/tel-03711326.
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L'encapsulation peut affecter la digestion et la bioaccessibilité des composés encapsulés, ce qui peut ensuite affecter leur métabolisme. Le but de ce projet était d'étudier les effets de l'encapsulation sur la bioaccessibilité et le métabolisme du DHA, en étudiant une huile de DHA non-encapsulée ou encapsulée, apportée sous forme d'omelette comme matrice alimentaire.L'huile de DHA, composée de triacylglycérols riches en DHA, a été préparée sous forme d'émulsion de Pickering, stabilisée par des isolats de protéines de lactosérum dénaturés par la chaleur. De l'huile pure ou sous forme d’émulsion a ensuite été ajoutée à l’œuf liquide pour obtenir de l’omelette. Les effets de l'encapsulation sur la digestion ont été étudiés à l'aide d'un modèle de digestion statique in vitro pour adulte, puis l’impact sur le métabolisme du DHA a été mesuré sur un modèle rat pris au sevrage.Les résultats ont montré in vitro que l'encapsulation peut augmenter la surface de contact entre l'huile de DHA et les enzymes de digestion, favorisant l'hydrolyse lipasique de l’huile de DHA et améliorant ainsi la bioaccessibilité du DHA. In vivo, l'encapsulation n'a pas impacté le profil global des acides gras, et particulièrement l’accrétion du DHA dans le cerveau. En revanche, le profil des oxylipines, dérivés oxydatifs d’acides gras, a été fortement modifié dans le plasma, le cœur et même le cerveau. Les métabolites dérivés du DHA ont globalement été augmentés tandis que ceux issus des acides gras de la famille n-6 ont été essentiellement atténués.Par conséquent, l'encapsulation de l'huile de DHA pourrait non seulement améliorer la bioaccessibilité du DHA, mais constitue également un facteur clé dans le métabolisme du DHA pour produire des précurseurs de protectines et de maresines, améliorant ainsi le statut de santé globalEncapsulation may affect the digestion and bioaccessibility of the encapsulated bioactive compounds, which in turn affects their metabolism. The purpose of this project was to study the effects of encapsulation on DHA bioaccessibility and metabolism, based on omelet as a food matrix, which contains DHA oil as encapsulated or unencapsulated form.DHA oil composed of DHA-rich triacylglycerols was prepared as a Pickering emulsion, which is stabilized by heat-denatured whey protein isolates. Pure oil or emulsion was then incorporated into eggs and cooked in an omelet. The effects of encapsulation on the digestion and metabolism of DHA were studied by using INFOGEST static in vitro digestion model for adults and in a weanling rat model, respectively.The results showed that encapsulation can increase the contact surface between DHA oil and lipase during the in vitro digestion, thereby promoting the hydrolysis of DHA oil and improving DHA bioaccessibility. In vivo, encapsulation of DHA oil did not modulate the fatty acid profile in tissues, but remarkably modified the oxylipin pattern in plasma, heart and even brain. Specific oxidized metabolites derived from DHA were upgraded while those from n-6 fatty acids were essentially mitigated.Therefore, encapsulation of DHA oil could not only improve the bioaccessibility of DHA, but is also a key factor in the metabolism of DHA to produce protectins and maresins precursors, thereby improving global health status
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Malcolm, Cari A. "Maternal docosahexaenoic acid (DHA) supplementation and infant visual development." Thesis, Glasgow Caledonian University, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.270513.
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Atnip, Allison A. "Oxidative Stabilities of Docosahexaenoic Acid Oil and Linoleic Acid in an Aqueous System." The Ohio State University, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=osu1284727595.
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Harvey, Jessica C. "The Effects of Fish Oil (EPA+DHA) on Chronic Ventilator Patients in a Long Term Acute Care Setting: A Randomized Control Trial." University of Cincinnati / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1307125476.
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Borges, Fábio Luiz 1984. "Predição de rendimentos de derivados de petróleo a partir de análises de destilação pelo método ASTM D7169 e DHA Front End realizadas em misturas de petróleos." [s.n.], 2014. http://repositorio.unicamp.br/jspui/handle/REPOSIP/266124.
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Orientador: Maria Regina Wolf MacielDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química
Made available in DSpace on 2018-08-24T13:22:45Z (GMT). No. of bitstreams: 1 Borges_FabioLuiz_M.pdf: 1928972 bytes, checksum: 8ee551cc8034ad570e84bd024b3702ca (MD5) Previous issue date: 2014
Resumo: Essa dissertação tem como objetivo avaliar a utilização de curvas de destilação simulada de petróleo analisadas por dois métodos cromatográficos (ASTM D7169 e DHA Front End) combinados em um modelo de predição de rendimentos de derivados de uma unidade de destilação atmosférica e a vácuo. Os métodos utilizados são de execução mais ágil e de custo bastante reduzido em relação aos métodos de obtenção de curvas de Ponto de Ebulição Verdadeiro (PEV), sendo viável obter curvas de destilação de tanques de petróleo em laboratórios de refinarias. A utilização dessas análises possibilita a obtenção de curvas das cargas a serem processadas mais representativas do que as curvas obtidas utilizando as curvas PEV disponíveis no BDAP (Banco de Dados de Avaliação de Petróleos da Petrobras) em conjunto com a proporção de petróleos informada pelo BDEMQ (Banco de Dados de Estoque, Movimentação e Qualidade da Petrobras) em cada tanque. Para realizar essa avaliação, foi elaborada, no software PETROSIM®, uma simulação do tipo Distop, a qual foi calibrada utilizando-se as vazões e as curvas de destilação dos derivados amostrados em uma das plantas de destilação da Refinaria de Paulínia. Em seguida, foram coletadas amostras de tanques de petróleo, as quais foram analisadas pelos dois métodos combinados para obter as curvas de destilação, que foram utilizadas como dados de entrada da simulação calibrada, obtendo os rendimentos dos derivados. Foram também obtidos os rendimentos da mesma simulação calibrada utilizando como dados de entrada os dados de curvas PEV disponíveis no BDAP e também pelo método de predição baseado em rendimentos fixos de petróleos, que são gerados pelo software Blend-BR®, de propriedade da Petrobras, cujos dados de entrada também são as curvas PEV do BDAP. Os rendimentos obtidos por esses três métodos foram comparados com os rendimentos obtidos na unidade quando os tanques de petróleo amostrados foram processados. Os resultados obtidos indicaram que a simulação calibrada utilizando os dados analisados pelos métodos cromatográficos forneceu rendimentos mais aderentes aos realizados do que os outros métodos, principalmente na predição de rendimentos de nafta
Abstract: This thesis aims to evaluate the use of crude distillation curves analyzed by two combined chromatographic methods (ASTM D7169 and DHA Front End) combined into an atmospheric and vacuum crude distillation unit yields prediction model. These methods are faster to be executed and have the costs pretty lower compared to the methods used to obtain the True Boiling Point (TBP) curves, enabling to obtain distillation curves of crude tanks in refinery laboratories. These analyzes enable obtaining curves of the loads to be processed more representative than the curves obtained using the TBP curves available in BDAP (the Petrobras petroleum Database) and the proportion of oils informed by BDEMQ (the Petrobras feedstocks and quality Database) for each tank. To perform this evaluation, it was built in PETROSIM® software a Distop simulation, which was calibrated using flow rates and crude cuts distillation curves from the samples collected at on of the crude distillation units of Paulínia Refinery. Samples of oil tanks, which were analyzed by the two combined methods to obtain the distillation curves, were then used as input data the calibrated simulation, obtaining the crude cuts yields. The cuts yields were also obtained by the same calibrated simulation using as input data TBP curves available at BDAP and also by a model based on fixed crude cuts yields, which are performed by the software Blend-BR®, property of Petrobras, whose data input are also the TBP curves available at BDAP. The yields obtained by these three methods were compared with the yields obtained in the industrial unit when the sampled oil tanks were processed. The results indicated that the calibrated simulation using data analyzed by the chromatographic methods provided yields that are closer to actual ones than other methods, especially for the naphtha yields
Mestrado
Desenvolvimento de Processos Químicos
Mestre em Engenharia Química
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Tippetts, Megan. "Effect of Processing and Formulation Conditions on Physicochemical Characteristics of Food Emulsions." DigitalCommons@USU, 2008. https://digitalcommons.usu.edu/etd/147.
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The objective of this research was to systematically study the effect of processing conditions on crystallization behavior and destabilization mechanisms of oil-in-water (o/w) emulsions. The effects of oil content (20 and 40 wt %); crystallization temperature (Tc = 10, 5, 0, -5, -10 °C); homogenization conditions, such as high shear (HS), very low pressure homogenization (VLPH), and high pressure homogenization (HPH); and cooling rate (0.2 and 30 °C/min) on both thermal behavior and destabilization mechanisms were analyzed. Docosahexaenoic acid (DHA) was added to VLPH emulsions and its effect on the physicochemical and oxidative stabilities and flavor was studied. Emulsions with 20% oil were less stable than those with 40% oil with a fast-cooling rate; however, stability increased when the emulsions were cooled slowly. Stability was also affected by oil and droplet size; the smaller the droplet the more stable the system. Smaller droplets (i.e., VLPH, HPH) had an effect on crystallization by delaying the onset of the crystal formation, which was promoted in emulsions with larger droplets (i.e., HS); 20% o/w emulsion crystallization was delayed more than 40%; and in emulsions crystallized using a slow-cooling rate, the crystal formation was less inhibited (i.e., crystals formed at a higher onset temperature [Ton], but at lower Tc) than when using a fast-cooling rate. The formation of lipid crystals either helped stabilize (small droplets) the emulsion and melted in a less fractionated manner or destabilized (big droplets) the emulsion. In addition, fast-cooling rates have greater fractionation than slow-cooling rates. Due to the greater stability of VLPH emulsions after thawing from being at -10 °C for 3 h, DHA was added to evaluate its effect on flavor (besides the effect on stability) of the emulsion. A descriptive panel was used to evaluate four attributes: oxidized, rancid, fishy, and buttery. The panelists were given samples after 72 h, because contrary to the TBA analysis which showed no significant differences between samples with and without DHA, the fishy smell was evident. The sensory evaluation results showed that there was a significant (p < 0.05) difference in fishiness between the VLPH emulsions with and without DHA, and that the odor was repulsive. No significance was seen for rancid and buttery flavors, and only a marginal significance was seen for oxidized.
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Neijat, Mohamed. "Omega-3 fatty acid enrichment of chicken eggs: Regulation of long chain polyunsaturated fatty acid metabolism in laying hens." Poultry Science, 2014. http://hdl.handle.net/1993/32076.
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Eggs enriched with omega-3 polyunsaturated fatty acids (PUFA), particularly the longer chain PUFA (LCPUFA, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)) can boost human consumption of these fatty acids implicated in human health. Alpha-linolenic acid (ALA) from plant seeds/oils, primarily serve as the source of omega-3 PUFA for hens, however, the scarcity of ALA-rich plants and the limited conversion of ALA to LCPUFA are challenges for egg enrichment. Two major experiments were conducted to determine potential factors regulating egg enrichment of omega-3 LCPUFA based on detailed assessment of PUFA profiles in different lipid pools of hen tissues. In experiment 1, supplementation of graded levels of hempseed products, provided ~ 0.1 to 1.3% of ALA in the diets. Experiment 2, investigated dietary supplementation of flaxseed oil (ALA-rich) and algal DHA (preformed LCPUFA), each providing similar graded levels of total omega-3 PUFA. Both ALA-containing models demonstrated a plateau in DHA enrichment of eggs at higher ALA intakes. ALA-containing diets led to high concentrations of ALA in the triacylglycerol (TAG) fraction of eggs and plasma, and the adipose tissue of flaxseed oil-fed hens. In total phospholipid (PL), particularly the phosphatidylethanolamine (PE), the levels of EPA and ALA in the yolk were linearly associated with those in the liver. In all tissues, DHA dominated the PE pool, exhibiting a plateau with a strong inverse correlation to the ratio of ALA to EPA in the liver, suggesting limited ALA availability for egg DHA enrichment. The use of algal DHA should therefore permit further accumulation of DHA in the total PL and TAG fractions of yolk. However, enrichment via preformed DHA (at 3.36% algal product) was also limited by hepatic PL resulting in more DHA and EPA being shunted to the adipose TAG, concurrent with elevated hepatic acyl-CoA synthetase (ACSL1) expression. As a function of total omega-3 PUFA intakes (regardless of source), similar levels of stearidonic acid (SDA) and particularly EPA accumulated in liver PE. Therefore, hepatic PL regulation, possibly aimed at maintaining EPA level, may potentially be limiting the amount of ALA accumulation in the same pool, hence limiting the endogenous synthesis of DHA and subsequent enrichment in eggs.February 2017
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Rosing, Keith Andrew. "The Feasibility of a Randomized Controlled Trial Investigating the Effects of Fish Oil - Eicosapentaenoic Acid (EPA) and Docosahexanoic Acid (DHA) - on Chronic Ventilator Patients in a Long-Term Acute Care Hospital (LTACH) Setting." University of Cincinnati / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1241813078.
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Jensen, Maren T. "Effects of A-beta immunotherapy and Omega-3 fatty acid administration in Alzheimer's transgenic mice." [Tampa, Fla] : University of South Florida, 2006. http://purl.fcla.edu/usf/dc/et/SFE0001438.
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Woodman, Richard John. "The independent effects of purified EPA and DHA supplementation on cardiovascular risk in treated-hypertensive type 2 diabetic individuals." University of Western Australia. School of Medicine and Pharmacology, 2003. http://theses.library.uwa.edu.au/adt-WU2003.0028.
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[Formulae and special characters can only be approximated here. Please see the pdf version of the Abtract for an accurate reproduction.] Type 2 diabetes at least doubles the risk of cardiovascular disease. This can partly be explained by the increased prevalence of risk factors such as hypertension, dyslipidaemia and obesity. However, the underlying abnormality of insulin resistance and the presence of more recently identified risk factors including endothelial dysfunction, increased inflammation, and increased oxidative stress might also contribute towards the heightened cardiovascular risk. Fish oil, which contains eicosapentaenoic acid (EPA, 20:5 n-3), has wide-ranging beneficial effects on these and other abnormalities, and has reduced cardiovascular mortality in secondary prevention studies. Animal and human studies have recently established that in addition to EPA, docosahexaenoic acid (DHA, 22:6 n-3) also has beneficial effects, and furthermore, may have less detrimental effects than EPA on glycaemic control which has worsened in some fish and fish oil studies involving Type 2 diabetic subjects. Study 1 : This intervention study aimed to determine the independent effects of EPA and DHA on cardiovascular risk factors and glycaemic control in individuals with Type 2 diabetes receiving treatment for hypertension. In a double-blind placebo-controlled trial of parallel design, 59 subjects in good to moderate glycaemic control (HbA1c < 9%) were recruited from media advertising and randomised to 4 g/day of EPA, DHA or olive oil (placebo) for 6 weeks. Thirty-nine men and 12 post-menopausal women aged 61.2±1.2 yrs completed the study. Relative to placebo, and with Bonferroni adjustments for multiple comparisons, serum triglycerides fell by 19% (p=0.022) and 15% (p=0.022) in the EPA and DHA groups respectively. There were no changes in serum total cholesterol, or LDL- and HDL-cholesterol, although HDL2-cholesterol increased 16% with EPA (p=0.026) and 12% with DHA (p=0.05). HDL3-cholesterol fell by 11% (p=0.026) with EPA supplementation and LDL particle size increased by 0.26±0.10 nm (p=0.02) with DHA. Urinary F2-isoprostanes, an in-vivo marker of oxidative stress was reduced by 19% following EPA (p=0.034) and by 20% following DHA. DHA but not EPA supplementation reduced collagen-stimulated platelet aggregation (16.9%, p=0.05) and thromboxane release (18.8%, p=0.03), but there were no significant changes in PAF-stimulated platelet aggregation. Fasting glucose rose by 1.40±0.29 mmol/l (p=0.002) following EPA and 0.98±0.29 mmol/l (p=0.002) following DHA. Neither EPA nor DHA had any significant effect on HbA1c, fasting serum insulin or C-peptide, insulin sensitivity, stimulated insulin secretion, 24-hr ambulatory blood pressure and heart rate, markers of inflammation, and fibrinolytic or vascular function. Study 2 : This study aimed to examine the influence and causes of increased inflammation on vascular function in subjects recruited for Study 1. Compared with healthy controls (n=17), the diabetic subjects (n=29) had impaired flow-mediated dilatation (FMD) (3.9±3.0% vs 5.5±2.4%, p=0.07) and glyceryl-trinitrate mediated dilatation (GTNMD) (11.4±4.8% vs 15.4±7.1%, p=0.04) of the brachial artery. They also had higher levels of the inflammatory markers C-reactive protein (2.7±2.6 mg/l vs 1.4±1.1 mg/l, p=0.03), fibrinogen (3.4±0.7 g/l vs 2.7±0.3 g/l, p<0.001) and tumor necrosis factor-alpha (20.9±13.4 pg/l vs 2.5±1.7 pg/l, p<0.001). In diabetic subjects, after adjustment for age and gender, leukocyte count was an independent predictor of FMD (p=0.02), accounting for 17% of total variance. Similarly, leukocyte count accounted for 23% (p<0.001) and IL-6 for 12% (p=0.03) of variance in GTNMD. Von Willebrand factor, a marker of endothelial cell activation was correlated with leukocyte count (r=0.38, p=0.04), FMD (r=-0.35, p=0.06) and GTNMD (r=-0.47, p=0.009), whilst P-selectin, a marker of platelet activation was correlated with fibrinogen (r=0.58, p=0.001). Conclusion : EPA and DHA have similar beneficial effects on triglycerides, HDL2 cholesterol and oxidative stress in individuals with Type 2 diabetes and hypertension. However, DHA also increases LDL particle size and reduces collagen-stimulated platelet aggregation and thromboxane release, thus offering more potential than EPA as an anti-thrombotic agent. The beneficial effects of both oils were potentially offset by deterioration in glycaemic control. Neither oil affected blood pressure or vascular function. Longer-term studies with major morbidity and mortality as the primary outcome measures are required to assess the overall benefits and risks of EPA and DHA. The cross-sectional observations from Study 2 are consistent with the hypothesis that impaired vascular function in individuals with Type 2 diabetes and hypertension is at least in part secondary to increased inflammation, with associated endothelial and platelet activation.
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Fernández, Castaño Irene. "Efecto de la administración de ácido docosahexanóico sobre las alteraciones metabólicas y sobre la distribución de grasa corporal en pacientes con infección por VIH-1 sometidos a tratamiento antiretroviral." Doctoral thesis, Universitat Autònoma de Barcelona, 2016. http://hdl.handle.net/10803/399575.
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Introducción. La hipertrigliceridemia es común en los pacientes con infección por VIH. Los ácidos grasos omega 3 reducen los niveles de triglicéridos (TG) en pacientes con infección por VIH. Se desconoce si la suplementación con ácido docosahexanóico (DHA) puede reducir los niveles de TG y/o modificar la distribución corporal de grasa en pacientes con infección por VIH-
Métodos. Se trata de un estudio randomizado, doble ciego, controlado con placebo con 84 pacientes tratados con antirretrovirales que tenían niveles de TG en ayunas entre 2.26 y 5.65 mmol/l y fueron ranzomizados a recibir DHA o placebo durante 48 semanas. Se midieron los niveles de TG basalmente, a las 4, 12, 24, 36 y 48 semanas. Se realizó una densitometría (DXA) basalmente y a las 48 semanas para estudiar la distribución de grasa corporal. En un subgrupo de 39 pacientes se midieron marcadores de inflamación y moleculares en tejido adiposo subcutáneo basalmente y a las 48 semanas. Este estudio está registrado con Clinical Trials.gov, NCT02005900.
Resultados. Los pacientes que recibieron DHA tuvieron un descenso del nivel de TG del 43.9% de media en la semana 4 (IQR: -31% a 56%) comparado con un -2.9% (-18.6% a 16.5%) en el grupo de placebo (p < 0.0001). Se observó una correlación significativa entre los niveles de DHA y el descenso de los niveles de TG en la semana 4 en la rama de DHA ( r = 0.7110, p < 0.0001). En la semana 12 la media de descenso de los niveles de TG en la rama de DHA fue de -43,7% (-32.4% a -57.5%) y en la placebo fue 2.9% (-21.3% a 30.1%). La diferencia entre ambos brazos siguió siendo estadísticamente significativa a la semana 48 ( p = 0.0253). Los niveles de colesterol de baja densidad (LDL) aumentaron significativamente en la rama de DHA a la semana 4, 7.1% (IQR: -4.8% a 35.3%) pero no en el brazo de placebo. No se observaron diferencias significativas en los niveles de colesterol de alta densidad (HDL), insulina, HOMA, ni FGF 19 y FGF21. La grasa en las ectremidades aumentó significativamente en ambos grupos sin diferencias significativas ( p = 0.3889). La proteína C reactiva de alta sensibilidad (hsPCR) y los niveles de ácido araquidónico disminuyeron en el grupo de DHA. Los genes relacionados con la adipogénesis (PPAR-γ, adiponectina) y la expresión de genes relacionados con la mitocondria no tuvieron cambios significativos en ambos grupos. El DNA mitocondrial disminuyó en el grupo placebo significativamente. La expresión de genes relacionados con la inflamación en tejido adiposo subcutáneo (TNF-α, MCP-1) disminuyó significativamente en el grupo de DHA permaneciendo estables en el placebo. DHA fue muy bien tolerado, solo 3 pacientes experimentaron toxicidad limitante del tratamiento.
Conclusiones. La suplementación con DHA reduce los niveles de TG en ayunas en pacientes con infección por VIH en tratamiento con antirretrovirales. DHA fue muy bien tolerado con síntomas gastrointestinales leves. La grasa periférica aumentó significativamente en el grupo de DHA pero no comparándolo con el grupo de placebo. La suplementación con DHA disminuye la expresión genética de inflamación en el tejido adiposo subcutáneo pero no modifica la expresión genética de la adipogénesis. DHA disminuye significativamente los niveles de hsPCR y ácido araquidónicoBackground. Hypertriglyceridemia is common in HIV-infected patients. Omega-3 fatty acids reduce fasting serum triglyceride (TG) levels in HIV-infected patients. It is not known whether docosahexanoic acid (DHA) supplementation can reduce hypertriglyceridemia and modify fat distribution in HIV-infected patients. Methods. We conducted a randomized, double-blind, placebo-controlled trial with 84 antiretroviral-treated patients who had fasting TG levels from 2.26-5.65 mmol/l and were randomized to receive DHA or placebo for 48 weeks. TG levels were assessed at baseline, week 4 and every 12 weeks. Body composition was assessed at baseline and at week 48. And systemic inflammatory and molecular SAT markers were assessed at baseline and at week 48 in a subgroup of 39 patients. This study is registered with ClinicalTrials.gov, NCT02005900. Results. Patients receiving DHA had a 43.9% median decline in fasting TG levels at week 4 (IQR: -31% to -56%), compared with -2.9% (-18.6% to 16.5%) in the placebo group (P < 0.0001). There was a significant correlation between DHA levels and decrease in TG at week 4 in the DHA arm (r = 0.7110, P < 0.0001). By week 12, the median reduction in TG levels in the DHA arm was -43.7% (-32.4% to -57.5%), and in the placebo arm +2.9% (-21.3% to +30.1%). The difference between study arms remained statistically significant at week 48 (P = 0.0253). Low-density lipoprotein cholesterol levels had significantly increased at week 4 by 7.1% (IQR: -4.8% to +35.3%) in the DHA arm but not in the placebo group. No significant changes were observed in HDL cholesterol, insulin, and HOMA-IR during the study. Limb fat significantly increased in both arms, without statistically significant differences between groups (P = 0.3889). High sensitivity C reactive protein (hsCRP) and arachidonic acid levels significantly decreased in the DHA group. Adipogenesis-related genes (PPAR-γ, adiponectin) and mitochondrial-related gene expression did not experience significant changes in either group. Mitochondrial DNA (mtDNA) significantly decreased in the placebo group. SAT inflammation-related gene expression (TNF-α, MCP-1) significantly decreased in the DHA but remained unaltered in the placebo group. DHA was well tolerated; only 3 patients experienced treatment-limiting toxicity. Conclusions Supplementation with DHA reduced fasting TG levels in antiretroviral-treated HIV-infected patients with mild hypertriglyceridemia. DHA was well tolerated with minor GI symptoms. Peripheral fat significantly increased in the DHA group but did not increase significantly compared with placebo. DHA supplementation down-regulated inflammatory gene expression in SAT, but did not modify adipogenesis-related gene expression. DHA impact on markers of systemic inflammation was restricted to a significant decrease in hsCRP and arachidonic acid.
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Tagliaferri, Camille. "Mécanismes de la perte osseuse et musculaire avec l'âge et étude du potentiel de l'huile d'olive, de la vitamine D et du DHA pour une stratégie nutritionnelle de prévention." Thesis, Clermont-Ferrand 1, 2014. http://www.theses.fr/2014CLF1MM20.
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Les sociétés économiquement développées sont confrontées à la problématique du vieillissement de leur population associée à la recrudescence des pathologies dégénératives. Parmi les manifestations du vieillissement, l'atteinte de l'appareil locomoteur (ostéoporose et sarcopénie) est considérée comme un problème majeur de santé publique. De ce fait, le développement de mesures préventives permettant de préserver la santé des séniors constitue un véritable enjeu de santé publique. La recherche scientifique fournit de nombreuses preuves concernant l'importance de l'alimentation dans la diminution ou l'exacerbation de certaines maladies. Ces observations confirment le vieux concept soutenant que l'adoption d'une alimentation équilibrée permet le maintien d'un état de santé satisfaisant, en particulier avec l'avancée en âge. A ce jour, le potentiel de l'huile d'olive, en tant que telle ou comme vecteur de nutriments lipophiles d'intérêt pour la prévention nutritionnelle de l'ostéoporose et de la sarcopénie, n'a jamais été testé. La prévalence de l'ostéoporose étant très supérieure chez la femme ménopausée qui souffre également d'une perte musculaire accélérée, cette population a été ciblée dans la présente étude. Dans une première étape, des résultats originaux ont été obtenus concernant l'effet de l'ovariectomie sur le métabolisme musculaire. Ainsi, notre travail montre qu'après ablation des ovaires, la synthèse protéique musculaire est réduite, en association avec une diminution d'un marqueur de la protéolyse de ce tissu. Pris dans son ensemble, ces résultats démontrent un ralentissement du renouvellement protéique musculaire suite à l'ovariectomie. En termes de mécanismes mis en jeu, une augmentation de l'infiltration lipidique tissulaire a été observée. En parallèle du ralentissement du renouvellement musculaire après ovariectomie, une augmentation du renouvellement osseux, classiquement décrit dans la littérature, a été mis en évidence. Dans un second temps, l'effet de l'huile d'olive et plus particulièrement des polyphénols présents dans cet aliment en association avec la vitamine D et l'acide ocosahexaénoïque et leur éventuelle synergie a été évalué à l'aide d'un modèle d'ostéoporose post-ménopausique. Des souris ovariectomisées ont été soumises à une des 4 huiles suivantes : huile de maïs, huile d'olive raffinée, huile d'olive extra vierge ou huile de poisson. Pour chaque huile, un groupe supplémentaire de souris ovariectomisées a reçu de l'huile enrichie en vitamine D. Cette étude a permis de mettre en évidence un effet protecteur de l'association de l'huile d'olive extra vierge et de la vitamine D sur la perte osseuse induite par l'ovariectomie chez la souris. En effet, l'accélération du renouvellement osseux consécutive à la carence estrogénique est freinée par cette association de nutriments, qui diminuent également l'expression des marqueurs du stress oxydant et de l'inflammation. Les résultats obtenus sont en cours de validation chez l'Homme grâce à une investigation clinique réalisée chez des femmes ménopausées. Celle-ci a été mise en place au cours de ces travaux de thèseEconomically developed societies face the problem of an aging population combined with the increase in degenerative diseases. Among the signs of aging, musculoskeletal pathologies (osteoporosis and sarcopenia) are considered major public health problems. Therefore, the development of preventive measures to preserve seniors’ health is a real public health issue. Scientific research provides ample evidence of the importance of diet in diseases reduction or exacerbation. These observations confirm the old concept arguing that the adoption of a balanced diet helps to maintain a healthy life, especially with advancing age. To date, the potential of the olive oil, as such or as a vector of lipophilic nutrients, for the prevention of osteoporosis and sarcopenia, has never been tested. As the prevalence of osteoporosis is much higher in postmenopausal women who also suffer from an accelerated muscle mass loss, this population was targeted in this study. In a first step, original results were obtained regarding the effect of ovariectomy on muscle metabolism. Thus, our work showed that after removal of the ovaries, muscle protein synthesis was reduced in association with a decrease in the expression of a proteolysis marker of this tissue. Taken together, these results suggest a slowing down of muscle protein turnover after ovariectomy. In terms of mechanisms, an increase in lipid tissue infiltration was observed. The slowdown in muscle protein renewal after ovariectomy was associated with an increased bone turnover, classically described in the literature. In a second step, the effect of olive oil and more particularly its polyphenols in combination with vitamin D and docosahexaenoic acid and their possible synergy was assessed using a postmenopausal osteoporosis model. Ovariectomized mice were subjected to one of the following oils: corn oil, refined olive oil, extra virgin olive oil or fish oil. Four additional groups of ovariectomized mice received the oil fortified with vitamin D. This study demonstrated a protective effect of the combination of virgin olive oil and vitamin D on bone loss induced by ovariectomy in mice. Indeed, the acceleration of the bone turnover induced by the estrogen deficiency was inhibited by this combination of nutrients, which also decreased the expression of oxidative stress and inflammation markers. These results are currently being validated in a clinical investigation conducted in postmenopausal women, which has been established during this thesis work
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Rosing, Keith A. "The feasibility of a randomized controlled trial investigating the effects of fish oil- eicosapentaenoic acid (EPA) and docosahexanoic acid (DHA)- on chronic ventilator patients in a long term acute care hospital (LTACH) setting." Cincinnati, Ohio : University of Cincinnati, 2009. http://rave.ohiolink.edu/etdc/view.cgi?acc_num=ucin1241813078.
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Thesis (M.S.)--University of Cincinnati, 2009.Advisor: Sarah C. Couch. Title from electronic thesis title page (viewed July 28, 2009). Includes abstract. Keywords: Fish Oil; Long-term Acute Care Hospital Setting; Mechanical Ventilation. Includes bibliographical references.
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Roby, Mohamed Hussein Hamdy. "Synthèse et caractérisation de biomolécules antioxidantes." Thesis, Université de Lorraine, 2014. http://www.theses.fr/2014LORR0083/document.
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Un procédé enzymatique sans solvant a été développé permettant la synthèse d'un ester phénolique de DHA. L'optimisation des paramètres réactionnels a permis d'atteindre des rendements élevés (440 g/L) d'ester de DHA et d'alcool vanillique (DHA-VE), dont les activités biologiques et le potentiel applicatif ont été évalués. L'activité inhibitrice du DHA-VE vis-à-vis des radicaux ABTS, DPPH et hydroxyle a été démontrée. Un effet neuroprotecteur de l'ester a également été mis en évidence sur des neurones primaires de rat, exposés aux oligomères du peptide [bêta]-amyloïde. Une étude in vivo a permis de montrer que le greffage d'alcool vanillique conduit à une augmentation du taux de DHA au niveau des globules rouges et des neurones, indiquant une biodisponibilité accrue du DHA lorsque celui-ci est couplé au composé phénolique. Aucune toxicité visible de l'ester n'a été constatée. Par ailleurs, l'incorporation de DHA-VE dans divers systèmes émulsionnés a permis d'accroître leur stabilité à l'oxydation, quelles que soient les conditions de stockage. Ceci montre le potentiel de cet ester pour enrichir diverses matrices alimentaires en DHA, tout en améliorant leur stabilité à l'oxydation. Le procédé enzymatique développé a été appliqué à de l'huile de saumon, utilisée comme source d'acides gras polyinsaturés de la série oméga-3. L'incorporation totale de l’alcool vanillique (50 g/L) a été obtenue après 24 h de réaction, conduisant à la production d'une grande variété d'esters, représentatifs de la composition initiale de l'huile en acides gras. Le milieu réactionnel brut issu de l'alcoolyse de l'huile présente une grande stabilité et des propriétés antioxydantes importantes par rapport à l'huile de saumon native. En conclusion, l'approche consistant à assembler des composés phénoliques et des lipides polyinsaturés au sein d'une même structure semble prometteuse pour renforcer le potentiel applicatif de ces deux familles de biomolécules et produire de nouveaux ingrédients bioactifs stablesAn efficient solvent-free bioprocess was developed for the synthesis of DHA phenolic ester, using the lipase B from Candida antarctica. The protocol developed here led to high-level production (440 g/L) of DHA vanillyl ester (DHA-VE) that exhibits interesting application potential as food ingredient. DHA-VE was characterized by a high stability and a high radical scavenging activity towards DPPH, ABTS and hydroxyl radicals. Neuroprotective properties of DHA-VE were also demonstrated in rat primary neurons exposed to amyloid-[beta] oligomers. Enzymatic esterification of DHA with vanillyl alcohol (VA) led to increased DHA levels in erythrocytes and brain tissues of mice fed DHA-VE-supplemented diet comparing with DHA. No visible toxicity of the ester was found. Enrichment of emulsions with DHA-VE improved significantly their oxidative stability whatever the conditions of storage, showing the potential of DHA-VE to enrich various food matrices with DHA while protecting them against oxidation. The enzymatic process was applied to salmon oil as a source of omega-3 polyunsaturated fatty acids (PUFA). The total conversion of VA (50 g/L) was achieved after 24 h of reaction, leading to the production of a wide variety of esters that mirror the initial composition of the oil. The crude reaction medium recovered from salmon oil alcoholysis exhibited a high stability together with high antioxidant properties in comparison with native salmon oil. In conclusion, the approach that consists in bringing phenolic compounds and PUFA-rich lipids together within a single structure is expected to provide stable bioactive ingredients that should broaden the scope of application of omega-3 PUFAs whose health benefits are increasingly sought
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Ferreira, Ana Maria Coelho de Magalhães. "Efeito da suplementação de dietas com lípidos de origem marinha na composição em ácidos gordos da carne de borrego." Master's thesis, Universidade de Lisboa. Faculdade de Medicina Veterinária, 2016. http://hdl.handle.net/10400.5/11136.
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Dissertação de Mestrado em Engenharia Zootécnica/Produção AnimalO interesse em estudar a composição em ácidos gordos (AG) da carne de ruminantes advém da necessidade de descobrir diferentes vias para produzir carne mais saudável, isto é, com um teor de ácidos gordos polinsaturados (PUFA) mais elevado comparativamente ao teor de ácidos gordos saturados (SFA) e um balanço mais favorável entre os PUFA ómega-6 e ómega-3. O estudo realizado examinou os efeitos de diferentes fontes de PUFA de cadeia muito longa (LCPUFA) ómega-3 na composição de AG do músculo e da gordura subcutânea (GSC) de borregos. Assim, os principais objetivos deste estudo foram verificar de que forma a suplementação da dieta de borregos com lípidos de origem marinha (óleo de peixe e microalgas) afetou a composição de AG do músculo de borregos através da comparação do teor e tipo de AG das frações lipídicas do músculo (lípidos neutros e polares) e da GSC de borregos e se os AG provenientes das algas e do óleo de peixe se depositaram em quantidades significativas na carne ou na GSC. O ensaio foi realizado no INIAV-Santarém, em que foram utilizados 36 borregos Merino Branco, divididos em 3 grupos de 12 animais cada. O ensaio foi realizado durante 6 semanas, após uma semana de adaptação em que a dieta foi introduzida progressivamente. Os três grupos experimentais foram sujeitos a diferentes dietas: controlo, óleo de peixe e algas. Em geral, houve uma redução do 18:0 e uma acumulação de 18:1trans nos tecidos dos animas suplementados com lípidos de origem marinha comparativamente ao controlo, o que sugere a inibição do último passo da bioidrogenação ruminal. A suplementação das dietas com óleo de peixe e algas conduziram a um aumento de LCPUFA n-3 e CLAc9t11 na carne e na gordura dos borregos. No entanto, os níveis mais elevados de CLAc9t11 foram verificados no tratamento com óleo de peixe, o que sugere uma menor atividade da enzima Delta9-dessaturase no tratamento com algas relativamente ao do óleo de peixe.
ABSTRACT - The interest in study the fatty acid composition of ruminant meat comes from the need to find different ways to produce meat with a higher content of polyunsaturated fatty acids (PUFA) compared to saturated fatty acids and a favorable balance between PUFA omega-6 and omega-3. This study examined the effects of different marine sources in the fatty acid composition of subcutaneous fat and muscle of lambs. Thus, the aims of this study was verify if the dietary supplementation of lipids from marine sources (fish oil and microalgae) had an effect on the fatty acid composition of lambs muscle and compare the content and type of fatty acids in lipid muscle fractions (neutral and polar lipids) and subcutaneous fat, and also understand if fatty acids from algae and fish oil were deposited in significant quantities in these tissues. The experiment was conducted at INIAV-Santarem, where 36 Merino Branco lambs were divided into 3 groups of 12 animals each. The experiment was conducted over 6 weeks after one week of adaptation to the diet. The three groups were subjected to different diets: control, fish oil and algae. Overall, there was a reduction of 18:0 and an accumulation of 18:1trans in the tissues of animals supplemented with marine lipids compared to control, suggesting an inhibition of the last biohydrogenation step. Supplementation of diets with fish oil and algae led to an increase of n-3 LCPUFA and CLAc9t11 in meat and subcutaneous fat of lambs. However, the highest levels of CLAc9t11 were observed with the fish oil treatment suggesting a reduced Delta9-dessaturase enzyme activity on animals fed algae compared to those fed fish oil.
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Simoens, Christian. "Intravascular metabolism of lipid emulsions with different fatty acid pattern: influence on fatty acid profile of membrane phospholipids in target organs and cells." Doctoral thesis, Universite Libre de Bruxelles, 2011. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209776.
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Sánchez, Monsalve Diego Alejandro. "Downhole Gasification (DHG) for improved oil recovery." Thesis, University of Bath, 2014. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.642042.
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Gas injection, the fastest growing tertiary oil recovery technique, holds the promise of significant recoveries from those depleted oil reservoirs around the world which fall into a pressure range of (50-200) bar mainly. However, its application with the usual techniques is restricted by the need for various surface facilities such as enormous gas supply and storage. The only surface facility that downhole gasification of hydrocarbons (DHG) requires, on the other hand, is a portable electricity generator. DHG consists in producing inert gases, H2, CO, CO2 and CH4 through the steam reforming reaction of a part of the produced oil in a gasifier-reformer reactor positioned alongside the producer well in the reservoir. The gases, mainly H2 -the most effective displacing gas among produced gases- are injected into a gas cap above the oil formation, to increase oil recovery through a gas displacement drive mechanism. So far, DHG has only been tested under laboratory conditions using methane, pentane/reservoir gas and naphtha/reservoir gas as feedstock at conditions of reservoir pressure up to 130 bar. The studies varied reaction temperature, steam to carbon (S/C) ratio, catalyst types and catalyst loading in the gasifier-reformer reactor of a small pilot scale rig. These experimental studies demonstrated that pressure is one of the main factors influencing the effectiveness of the DHG process. From this starting point, the present investigation was directed at extending the pressure range up to 160 bar in the gasifier-reformer reactor using a naphtha fraction as feedstock in order to investigate whether the conversion and H2 concentration in produced dry gas can be maintained at acceptable levels under conditions of high pressure. To this end, experimental studies were carried out within the laboratory using the existing DHG rig on the small pilot scale, which was successfully commissioned and revamped for the purposes of this study. Initially, the investigation focused on exploring operating conditions, namely, steam to carbon (S/C) ratio, length of the gasifier-reformer reactor tube/ catalyst loading and the relative performance of two different catalysts. Subsequently, experiments on shutdown/start up cycles followed by variation of temperature were performed to simulate the effect of sudden electrical disruptions that usually occur in field operations. Experimental results using naphtha at pressure from 80 to 160 bar at 650 ºC, S/C= 6 achieved total feedstock conversion, no coke deposits and, most importantly, high H2 concentration in the produced dry gas (56-63 vol. % plus other gases). The best result was obtained with a crushed HiFUEL R110 catalyst (40-60 wt. % of NiO/CaO.Al2O3) and a reactor tube length of 72 cm, but the results with a C11-PR catalyst (40 wt. % of NiO/MgO.Al2O3) and a reactor tube length of 30 cm were similarly favourable. These results were supported by results of a numerical DHG model which indicated total feedstock conversion and values of H2 around 67 vol. % (using n-heptane as model surrogate). The results suggest that the DHG process is technically feasible at the pressure values studied, perhaps up to 200 bar where there are many hundreds of depleted, light oil reservoirs, especially in North America and other parts of the world below that pressure value.
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Drouin, Gaëtan. "Métabolisme et intérêt nutritionnel de l’acide docosapentaénoïque n-3 : modulation du statut tissulaire en acides gras n-3 par les lipides laitiers alimentaires chez le rat." Thesis, Rennes 1, 2018. http://www.theses.fr/2018REN1B020/document.
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L’optimisation du statut tissulaire en acides gras polyinsaturés à longues chaines n-3 (AGPILC n-3) fait partie des objectifs actuels en nutrition humaine. En effet, de nombreux effets bénéfiques sur la santé humaine ont été démontrés pour ces différents AGPILC n-3. Néanmoins, la bioconversion de ces dérivés à partir de leur précurseur alimentaire, l’acide α-linolénique, est limitée chez l’Homme et ne permet pas de subvenir aux besoins. Parmi cette famille d’acides, l’acide docosahexaénoïque (DHA) et de l’acide eicosapentaénoïque (EPA) ont été largement étudiés à l’inverse de ceux de l’acide docosapentaénoïque n-3 (DPA). Le premier objectif de ces travaux a été d’étudier l’impact d’une supplémentation nutritionnelle en DPA sur le métabolisme des acides gras et le métabolisme lipidique chez le rat sain. Pour cela, une méthode de purification du DPA à haute pureté et en grande quantité par chromatographie liquide a tout d’abord été mise en place. Ce résultat participe à faciliter la recherche future des effets in vivo du DPA dont la disponibilité commerciale est faible. Après sa supplémentation nutritionnelle, le DPA a été incorporé dans de multiples tissus et a impacté les compositions tissulaires en AGPILC n-3 de certains organes spécifiques comme le foie, le cœur, le poumon, la rate et le rein. Ainsi, la supplémentation en DPA pourrait être une source d’EPA, de DPA, et dans une moindre mesure de DHA. Enfin, comparé à une supplémentation en EPA ou en DHA, le DPA a été l’AGPILC n-3 le plus puissant pour améliorer la triglycéridémie et la cholestérolémie des animaux. Ces informations participeront certainement à une prise en compte plus importante du DPA tant dans les études nutritionnelles ainsi que dans l’installation des futures recommandations nutritionnelles. Le deuxième axe de recherche a porté sur la capacité d’une incorporation partielle de lipides laitiers dans le régime à augmenter le statut tissulaire en AGPI-LC n-3. L’incorporation de lipides laitiers a augmenté le statut en DHA cérébral et rétinien et le statut en DPA dans les autres tissus étudiés. De plus, l’induction de la conversion des AGPILC n-3 à partir de leur précurseur par les lipides laitiers a été complémentaire avec la supplémentation en DPA pour augmenter le statut tissulaire en AGPI-LC n-3. Ces résultats s’insèrent dans un contexte de nutrition infantile, période pendant laquelle l’incorporation des AGPI-LC n-3 est maximale dans les tissus nerveux. Ainsi, ces résultats apportent des données intéressantes tant pour les entreprises que pour les professionnels de santé pour recommander à la consommation des formules infantiles contenant des lipides laitiersThe optimization of tissue status in n-3 long-chain polyunsaturated fatty acids (n-3 LCPUFA) is one of the current goals in human nutrition. Indeed, many beneficial effects on human health have been demonstrated for these different n-3 LCPUFA. However, the bioconversion of these derivatives from their food precursor, α-linolenic acid, is limited in humans and it does not meet the needs of the organism. Among this family of fatty acids, docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) have been widely studied in contrast to those of n-3 docosapentaenoic acid (DPA). The first objective of this work was to study the impact of dietary supplementation with DPA on fatty acid metabolism and lipid metabolism in healthy rats. For this, a method for purifying DPA with high purity and in large quantities by liquid chromatography was first established. This result helps future research of the in vivo effects of DPA, poorly commercially available. After its nutritional supplementation, DPA was incorporated into multiple tissues and it has affected the n-3 LCPUFA tissue compositions of specific organs such as the liver, heart, lung, spleen and the kidney. Thus, supplementation with DPA could be a source of EPA, DPA, and to a lesser extent DHA. Finally, compared to supplementation with EPA or DHA, DPA was the most potent n-3 LCPUFA to improve triglyceridemia and cholesterolemia in animals. This information will certainly contribute to a greater consideration of DPA both in nutritional studies and in the direction of future nutritional recommendations. The second area of research focused on the ability of a partial incorporation of dairy lipids in the diet to increase the tissue status in n-3 LCPUFA. Incorporation of dairy lipids in the diet increased DHA status in brain and retina and DPA status in the other studied tissues. In addition, the induction of conversion of n-3 LCPUFA from their precursor by dairy lipid was complementary with the DPA supplementation to increase n-3 LCPUFA status in tissues. These results fit into a context of infant nutrition, during which the incorporation of n-3 LCPUFA is maximal in nervous tissues. Thus, these results provide interesting data for both companies and health professionals to recommend infant formulas containing dairy lipids for consumption
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Du, Qin. "Optimisation des profils lipidiques du cerveau de rats déficients en oméga-3 au sevrage par l'utilisation de matière grasse laitière : conséquences au niveau du lipidome." Thesis, Aix-Marseille 2, 2010. http://www.theses.fr/2010AIX20717/document.
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L‟acide docosahexaénoïque (DHA) s‟accumule principalement dans les membranes cérébrales humaines durant la période périnatale et les 2 premières années de la vie. Optimiser l‟incorporation des acides gras polyinsaturés à longue chaîne (AGPI-LC) n-3 dans le système nerveux central, notamment le DHA, constitue l‟un des objectifs majeurs de la nutrition néonatale et infantile. Ce projet étudie l‟effet de régimes à base de matière grasse laitière anhydre (MGLA) afin d‟améliorer la bioconversion des AGPI n-3 et l‟incorporation du DHA dans le cerveau. L‟autre objectif, au-delà des effets sur les acides gras, est d‟évaluer si l‟impact des apports destinés au jeune n‟exercent pas un effet plus large tels qu‟appréciés au niveau du lipidome du cerveau.Nous avons mis au point un modèle d‟expérimentation animale permettant d‟étudier les effets de mélanges de MGLA et d‟huiles végétales. Des mères sont nourries avec un régime déficient en acide α-linoléique (ALA) (0,4% des acides gras totaux (AGT)) pendant 6 semaines avant accouplement et pendant toute la gestation et la lactation. Après sevrage, quatre-vingts petits rats mâles et femelles ainsi carencés en AGPI n-3 sont séparés en 4 groupes et reçoivent des régimes à 10% de lipides pendant 6 semaines, soit à base d‟huile de palme mélangée avec des huiles vegétales pour un apport à 1,5%ALA (P1), ou 1,5% ALA supplementé avec 0,12%DHA et 0,4% acide arachidonique (ARA) (P2); soit à base de MGLA et d‟huiles végétales apportant 1,5%ALA (B1) ou 2,3%ALA (B2). Les acides gras cérébraux, plasmatiques et érythrocytaires ainsi que le profil lipidomique cérébral sont mesurés, et les résultats sont analysés en statistiques multivariées. Le régime B1 est supérieur aux deux régimes à base d‟huile de palme à 1,5 %ALA, pour restaurer la quantité de DHA du cerveau (augmentation de 14.38%, P < 0.05) ; le régime (B2) présente un bénéfice supplémentaire sur ce paramètre. Les concentrations cérébrales en DHA chez les rats mâles sont significativement plus faibles que chez les femelles en raison des interactions de l‟effet sexe sur l‟effet régime, mais cet effet s‟atténue avec les régimes MGLA ou l‟ajout de DHA préformés dans le régime palme (P2).Nous avons calculé un nouvel indice à l‟aide des profils en acides gras des globules rouges et du plasma pour prédire le contenu en DHA cérébral, et dont la performance est meilleure que celle des indices existants. Pour la première fois, nous avons pu mettre en évidence un effet majeur et inconnu jusqu‟alors, des régimes sur le lipidome du cerveau (analyse des espèces moléculaires de lipides), affectant près de 15% des espèces analysées. Ces changements semblent être liés, entre autres, au métabolisme du cholestérol, des acides gras et des messagers lipidiques.En conclusion, nos données sont susceptibles d„améliorer les formules infantiles. La première utilisation de l‟approche de lipidomique sans a priori que nous avons mise en oeuvre ouvre des perspectives nouvelles en nutrition infantileThe accretion of docosahexaenoic acid (DHA) in brain membranes mainly occurs around delivery and during the first two years of life. One of the main goals of neonatal nutrition is to optimize the incorporation of n-3 long chain polyinsaturate fatty acids (LC-PUFA) into the central nervous system, including DHA. Our goal was to study the impact of several kinds of diets based on dairy-fat to improve the n-3 LC-PUFA bioconversion and DHA accretion into brain. The other endpoint was to assess if beyond the brain fatty acid profiles, the dietary intakes would bring about a wider effect such as the one that can be appreciated through a lipidomic approach.We compared the nutritional effect of dairy-fat based diets to that of palm-oil based diets in the rat reproductive model. Mother rats were made deficient in α-linoleic acid (ALA) (0.4% of fatty acids (FA) for 6 weeks prior to mating and throughout gestation and lactation. After weaning, the resulting deficient 40 rat pups of either gender were split into 4 groups and received 10% fat diets made with either 1.5%ALA palm oil blend (P1), same added with 0.12% DHA and 0.4% arachidonic acid (ARA) (P2) , 1.5% ALA dairy-fat blend (B1) or 2.5% ALA dairy-fat blend (B2). The brain, red blood cell (RBC) and plasma fatty acid profiles were analyzed and treated using multivariate statistics. B1 was superior to both palm-oil based diets to improve the brain DHA contents (14.4% increase, P < 0.05). B2 brought an additional benefit for this parameter. The brain DHA contents in males were significantly lower than for the female because of a diet x gender interaction. This effect was smoothed with the dairy-fat diets or the palm-oil based diet augmented with preformed DHA.We calculated a new fatty acid index to predict the brain DHA contents, based on the fatty acid profiles measured in RBC and plasma, and which demonstrated a better performance than the existing published index. For the first time, we showed a profound and yet unsuspected effect of diets until now on the brain lipidome (lipids molecular species), affecting about 15% of the features detected. These changes were ascribed to the cholesterol and fatty acid metabolism, and to the lipid messengers, among others.In conclusion, our data appear highly relevant to improve infant formulas. The first use of the lipidomic approach in neonatal nutrition open the paths of new researches in the area of infant nutrition
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Burkey, Carren Nyambare. "Bioprocessing of soybean seed-coats for production of proteins & omega-3 fatty acids using Pythium isolates." Bowling Green State University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu159361093538274.
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Kim, Hyun-Jin. "Genetic analysis of a storage-oil deficient mutant of Streptomyces coelicolor A3(2)." Thesis, University of East Anglia, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.302210.
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Lund, Linnea. "Decline Curve Analysis of Shale Oil Production : The Case of Eagle Ford." Thesis, Uppsala universitet, Naturresurser och hållbar utveckling, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-235816.
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Production of oil and gas from shale is often described as a revolution to energyproduction in North America. Since the beginning of this century the shale oilproduction has increased from practically zero to currently supply almost half of theU.S. oil production. This development is made possible by the technology ofhorizontal drilling and hydraulic fracturing. Since the production has not been ongoingfor that long, production data is still fairly limited in length and there are still largeuncertainties in many parameters, for instance production decline, lifespan, drainagearea, geographical extent and future technological development. More research isneeded to be able to estimate future production and resources with more certainty. At the moment shale oil is extracted only in North America but around the worldinvestigations are starting to assess if the conditions are suitable from shale oilextraction elsewhere. The global technically recoverable resource has been estimatedto 345 Gb, 10% of all global technically recoverable resources. Health andenvironmental aspects of shale oil and gas production have not yet been investigatedthoroughly and there is a risk that these parameters may slow down or limit thespreading of shale development. This report aims to examine production patterns of shale oil wells by applying declinecurve analysis. This analysis comprises of analyzing historical production data toinvestigate how the future production may develop. The area of the study is the EagleFord shale play in Texas, U.S. The goal is to fit decline curves to production data andthen use them for making estimates of future production in the Eagle Ford. The production in the shale oil wells included in the study reach their peak already within a few months after production starts. After this point, production is declining.After one year, production has decreased by 75% and after two years the productionis 87% of the peak production. The hyperbolic decline curve has a good fit toproduction data and in many cases the curve is close to harmonic. It is too early todetermine whether the alternative decline curve that is tested, the scaling declinecurve, has a better fit in the long term. The report also investigates how the density of the petroleum affects the declinecurve. The result is that lighter products decline faster than heavier. A sensitivity analysis is performed to illustrate how different parameters affect thefuture production development. In addition to the wells’ decline rate, the assumptionson the maximum number of wells, the maximal production and the rate at which newwells are added affect the ultimately recoverable resource. These parameters all havelarge uncertainties and makes resource estimations more difficult.
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Endo, Fumihiro, Shinpei Yamamoto, Takayuki Sadakane, Akira Yamagishi, Katsunori Miyagi, and Hitoshi Okubo. "Analysis of Gasses Generated by Electrical Discharges in Low Viscosity Silicone Oil." IEEE, 2008. http://hdl.handle.net/2237/11797.
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Nyskohus, Laura Sophia, and laura nyskohus@flinders edu au. "Consequences of the regulation of DNA damage and other host responses by fish oil for colorectal oncogenesis." Flinders University. Medicine, 2009. http://catalogue.flinders.edu.au./local/adt/public/adt-SFU20090730.115059.
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The acute cellular responses to DNA damaging agents are critical in determining the long term outcome of disease. A cells susceptibility to damage, or its capacity to remove or repair this damage, all contributes to the eventual health or disease of tissues. This process is especially crucial in colonic epithelial cells and in the development of colorectal oncogenesis. The colonic lumen is constantly subjected to different environmental compounds that may have genotoxic properties that can initiate mutational events and possibly carcinogenesis. Therefore, the study of a regulatory dietary agent that improves the colonic cells ability to withstand damage, improve repair and retain its general health is a significant and practical tool in the fight against colorectal cancer.
The health benefits of fish oil, including its potential chemopreventative properties, have been reported in numerous studies. However, the mechanism by which this protective effect occurs remains unclear. A gap in current literature exists that fails to explore the effect of fish oil on the early cellular responses to carcinogenic agents. Therefore, this thesis aims to firstly, better understand the specific host responses to an insult of carcinogen in vivo; secondly, to determine if regulation of these responses can be achieved by dietary fish oil; and lastly, to explore the potential consequences of this regulation for colorectal oncogenesis.
All experimental work was carried out using a rat azoxymethane (AOM) animal model of colorectal carcinogenesis. The key host responses to the carcinogen that were measured included the formation of acute O6methyldeoxyGuanosine (O6medG) DNA damage, the acute apoptotic response to genotoxic carcinogen (AARGC) and cell proliferation rates. A novel immunochemical assay was designed to detect both the levels and distribution of O6medG in colonic cells. With this established, a pattern of these host responses were mapped out over time. A dietary intervention study trialling a range of fish oil diets containing different doses and forms was then carried out to determine if modulation of responses occurred. This study was then followed on by a longer term study that explored the consequences of regulation by fish oil on pre-neoplastic lesions in the colon.
The acute host responses to an insult of AOM showed that colonic O6medG formation began 2h post AOM administration and peaked at 6h. The AARGC response followed the pattern of O6medG by a 2h delay, peaking at 8h post AOM administration, while cell proliferation rates decreased significantly after 6h.
The inclusion of tuna oil in the diet did not affect either the AARGC or cell proliferation rates when given in any form or at any dose. Animals fed a diet with 15% free tuna oil and 7% encapsulated tuna oil did however have significantly reduced levels of O6medG DNA damage in the distal colon. This reduction in O6medG levels did not translate into a reduction of ACF lesion, with a protective effect against ACF lesions only being observed in animals fed the high dose fish oil groups.
Analysis of the data suggest that the acute host responses to an insult of DNA damaging agent appear to be closely related, all reaching their peak level of response 6-8h after the insult. The short time frame between both O6medG and apoptosis also did not support the current popular theory which explains O6medG mediated apoptosis. An alternate hypothesised BER mediated apoptotic pathway was also not supported.
Regulation of the acute apoptotic response or the cell proliferation rate was not achieved by dietary fish oil. However, a high dose fish oil diet did regulate the level of O6medG in colonic epithelial cells by significantly reducing the total O6medG DNA damage load. This reduction of O6medG by a high fish oil diet however, was not translated into a protective effect against the formation of pre-neoplastic lesions. These data suggests that regulation of the acute O6medG response to a damaging agent does not necessarily imply protection for longer term colorectal oncogenesis. Additional studies exploring both the effect of fish oil on AOM metabolising enzymes and also a longer term cancer study may help to answer some pertinent questions evolving from this thesis.
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Ye, Weiping. "Mechanisms of anticancer activities of (-)-gossypol-enriched cottonseed oil against human breast cancer cells." Columbus, Ohio : Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1174672705.
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Ribeiro, Robival Alves. "Correla??es nos dfa de diversos perfis geol?gicos. estudo de caso: Bacia de Campos - RJ." Universidade Federal do Rio Grande do Norte, 2010. http://repositorio.ufrn.br:8080/jspui/handle/123456789/12917.
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Previous issue date: 2010-04-14This work aims to study the fluctuation structure of physical properties of oil well profiles. It was used as technique the analysis of fluctuations without trend (Detrended Fluctuation Analysis - DFA). It has been made part of the study 54 oil wells in the Campo de Namorado located in the Campos Basin in Rio de Janeiro. We studied five sections, namely: sonic, density, porosity, resistivity and gamma rays. For most of the profiles , DFA analysis was available in the literature, though the sonic perfile was estimated with the aid of a standard algorithm. The comparison between the exponents of DFA of the five profiles was performed using linear correlation of variables, so we had 10 comparisons of profiles. Our null hypothesis is that the values of DFA for the various physical properties are independent. The main result indicates that no refutation of the null hypothesis. That is, the fluctuations observed by DFA in the profiles do not have a universal character, that is, in general the quantities display a floating structure of their own. From the ten correlations studied only the profiles of density and sonic one showed a significant correlation (p> 0.05). Finally these results indicate that one should use the data from DFA with caution, because, in general, based on geological analysis DFA different profiles can lead to disparate conclusions
Esta disserta??o tem como objetivo estudar a estrutura de flutua??o de propriedades f?sicas dos perfis de po?os de petr?leo. Usou-se como t?cnica a an?lise de flutua??es sem tend?ncia (Detrended Fluctuation Analysis DFA). Fizeram parte do estudo 54 po?os de petr?leo do Campo de Namorado localizado na Bacia de Campos, no Estado do Rio de Janeiro. Foram estudados cinco perfis, quais sejam: s?nico, densidade, porosidade, resistividade e raios gama. Para a maioria dos perfis, a an?lise de DFA j? estava dispon?vel na literatura; entretanto o perfil s?nico foi estimado com o aux?lio de um algoritmo padr?o. A compara??o entre os expoentes de DFA dos cinco perfis foi feita usando correla??o linear de vari?veis; assim t?nhamos 10 compara??es de perfis. Nossa hip?tese nula ? que os valores de DFA para as diversas propriedades f?sicas s?o independentes. O principal resultado indica a n?o refuta??o da hip?tese nula. Isto ?, as flutua??es apresentadas pelos DFA dos perfis n?o apresentam um car?ter universal; ou seja, em geral, as grandezas exibem uma estrutura de flutua??o que lhes ? pr?pria. Das dez correla??es estudadas, apenas os perfis de densidade e o s?nico apresentaram uma correla??o significativa (p<0,05). Enfim, estes resultados indicam que se devem usar os dados de DFA com cautela, pois, em geral, an?lises geol?gicas baseadas em DFA de perfis diferentes podem levar a conclus?es d?spares
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AL-Amery, Maythem. "IMPACT OF A HIGH OIL AND PROTEIN ON AGRONOMIC TRAITS AND OVERALL SEED COMPOSITION IN SOYBEAN." UKnowledge, 2017. https://uknowledge.uky.edu/pss_etds/97.
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New soybean lines have been developed with significantly higher oil, protein + oil and higher meal protein. These soybeans contain a VgD1 gene (highly active acyl-CoA:diacylglycerol acyltransferase, DGAT from Vernonia galamensis (VgDGAT1A) produces much higher oil synthesis and accumulation activity in soybean. Soybean with active DGAT from Vernonia galamensis (VgDGAT1A) has active TAG biosynthesis relative to other DGATs including from soybeans and Arabidopsis. DGATs catalyze the final step of TAG synthesis: DAG (diacylglycerol) + acyl-CoA → TAG + CoASH (Coenzyme A is notable for its role in the synthesis and oxidation of fatty acids, and the oxidation of pyruvate in the citric acid cycle). A thorough analysis of the major components in VgD1 lines, especially those of nutritional or anti-nutritional value including what else changed (decreased); and what remained at normal levels was conducted. A field study was conducted in Spindletop and Princeton KY, reviled no reduction in yield nor protein, and about 4 % (DW) more oil was obtained in Princeton and 2% (DW) in Spindeltop. No consistent reduction in the other seed composition.VgDGAT1A soybean lines indicated noticeably early maturation compared to the parental line. This is associated with higher expression of the flowering genes FT2 (FLOWERING LOCUS T2) and FT5 (FLOWERING LOCUS T5), for the high oil lines. A single recessive mutation in soybean (MIPS) myo-inositol 1-phosphate synthase, confers a seed phenotype of increase inorganic phosphate (Pi) crossed with high oil lines expressing a DGAT from Vernonia galamensis (VgDGAT1A) (VgD). The oil and protein were maintained compart to VgD. VgD X MIPS (VM), had 21.2, and 22 % oil in 2015, and 23.3 and 24.0 oil in 2016, and protein 46, 49 in 2015, and 37 and 39 % in 2016. Phosphate results suggesting the cross MV is still segregating for MIPS and more selection and planting are needed.
Measurement of seed phosphate levels is an established technique for screening for low phytate mutants but to date, it has not been performed non-destructively from single soybean seeds. A protocol was developed greatly reducing the sample size thereby reducing the cost and time and saving a generation in the selection of low phytate mutant seeds based on the high Pi phenotype.
Genotyping single seeds are useful in breeding and genetics while maintaining high germination rates. Nondestructive single-seed genomic DNA extraction protocols using 12 mg cotyledon tissue with a modified cetyl trimethyl ammonium bromide (CTAB) technique and a commercial seed DNA extraction kit using 1 mg cotyledon tissue were developed for dry soybean seeds and cross-verified with leaf DNA analysis.
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Maester, Thais Carvalho. "Prospecção de sequências genômicas codificadoras de enzimas lipolíticas degradadoras de hidrocarbonetos de petróleo." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/87/87131/tde-15092011-151851/.
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Enzimas lipolíticas possuem enorme potencial biotecnológico. O objetivo foi prospectar genes para a codificação de enzimas lipolíticas em biblioteca metagenômica com 4224 clones. A atividade lipolítica foi avaliada pela formação de halo ao redor das colônias através do cultivo dos clones em meio de cultura suplementado com tributirina, sendo positiva para 30 clones, e dois foram selecionados e tiveram o DNA sub-clonado. Os DNAs das sub-bibliotecas foram sequenciados, gerando um contig completo para o clone PL28.F10, que foi comparado com as sequências do banco NCBI. Uma ORF codificadora de esterase/lipase de 303 aminoácidos e 61% de identidade com micro-organismo não cultivável foi encontrada. Árvores filogenéticas indicam que o clone possui a ORF15 mais próxima da família IV das esterases/lipases. Foi possível identificar os sítios ativos representativos da família, confirmando o resultado das árvores filogenéticas. Com sequências já patenteadas, a ORF15 é um grupo irmão das sequências de esterases/lipases da BASF e de uma proteína não identificada da CAMBIA.Lipolytic enzymes have show enormous biotechnological potential. The work was done to find genes which codify lipolytic enzymes in a metagenomic library with 4224 clones. Clones were selected according to lipolytic activity and were assessed by cultivation in medium supplemented with tributyrin. Assessment was done by observation of halos formed around the colonies, with 30 clones producing halos. Of these, two were selected. DNA from the sub libraries was sequenced, generating a complete contig for clone PL28.F10 that was compared to sequences from the NCBI. An ORF of 303 amino acids with 61% of identity with uncunturable microorganism were found. The clone presented the ORF15 similar to that of lipolytic enzyme family IV. The alignments made possible the identification of active sites which represent the family, confirming the results obtained with the construction of the cladograms. The ORF15 showed similarities to patented BASF esterase/lipase and an unnamed protein of CAMBIA.
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Dong, Bo. "Fiber Optic Sensors for On-Line, Real Time Power Transformer Health Monitoring." Diss., Virginia Tech, 2012. http://hdl.handle.net/10919/77175.
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High voltage power transformer is one of the most important and expensive components in today's power transmission and distribution systems. Any overlooked critical fault generated inside a power transformer may lead to a transformer catastrophic failure which could not only cause a disruption to the power system but also significant equipment damage. Accurate and prompt information on the health state of a transformer is thus the critical prerequisite for an asset manager to make a vital decision on a transformer with suspicious conditions.
Partial discharge (PD) is not only a precursor of insulation degradation, but also a primary factor to accelerate the deterioration of the insulation system in a transformer. Monitoring of PD activities and the concentration of PD generated combustible gases dissolved in the transformer oil has been proven to be an effective procedure for transformer health state estimation. However current commercially available sensors can only be installed outside of transformers and offer indirect or delayed information.
This research is aimed to investigate and develop several sensor techniques for transformer health monitoring. The first work is an optical fiber extrinsic Fabry-Perot interferometric sensor for PD detection. By filling SF6 into the sensor air cavity of the extrinsic Fabry-Perot interferometer sensor, the last potential obstacle that prevents this kind of sensors from being installed inside transformers has been removed. The proposed acoustic sensor multiplexing system is stable and more economical than the other sensor multiplexing methods that usually require the use of a tunable laser or filters. Two dissolved gas analysis (DGA) methods for dissolved hydrogen or acetylene measurement are also proposed and demonstrated. The dissolved hydrogen detection is based on hydrogen induced fiber loss and the dissolved acetylene detection is by direct oil transmission measurement.Ph. D.
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Neto, Eduardo Piber. "Enriquecimento do ovo: utilização de óleos de peixes e alga marinha como fontes de ácidos graxos poliinsaturados ômega-3 em rações de galinhas." Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/10/10136/tde-29012007-132108/.
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Foram utilizadas 168 galinhas poedeiras Hisex White em delineamento experimental inteiramente casualizado, com duração de cinco semanas. As aves foram distribuídas em sete tratamentos com três repetições cada, com o objetivo de verificar a influência da suplementação de três fontes marinhas de PUFAs n-3 - óleos de salmão (SA) e de atum e sardinha (A/S) e mistura de algas marinhas (AL), bem como sua combinações (SA+A/S, AL+SA, AL+A/S) - em relação ao grupo controle alimentado com ração basal de milho e soja (CON), sobre a qualidade do ovo e a composição lipídica da gema. A qualidade externa e interna do ovo não foi alterada significativamente pela adição de fontes de PUFAs n-3 na dieta das aves. A relação entre os lípides saturados : monoinsturados : poliinsaturados da gema (3,5 : 4,5 : 2,0) manteve-se constante com a adição dos suplementos de PUFAs n-3 na ração. Os óleos de salmão (SA) e de atum e sardinha (A/S) revelaram-se mais efetivos no enriquecimento da gema do ovo em PUFAs n-3, em especial o DHA. A relação PUFAs n-6/ PUFAs n-3 sofreu redução significativa com a adição das fontes marinhas de ômega-3 à dieta das galinhas. O EPA, embora em teores mais baixos que o DHA na gema do ovo, apresentou incremento significativo com o uso dos óleos de peixes (SA e A/S) adicionado à dieta em relação ao CON. O consumo de dois ovos enriquecidos com DHA do presente estudo, por dia, provavelmente atenderia os requerimentos diários deste PUFA n-3 para o ser humanoTo investigate the influence of three PUFAs n-3 marine sources - salmon oil (SA), tuna and sardine oil (A/S), marine algae (AL) and combinations (SA+A/S, AL+SA, AL+A/S) - on egg quality and egg lipid composition, compared to a corn/soy control group (CON), 168 Hisex White laying hens were assigned into seven treatments with three repetitions in a randomized design during a experimental period of five weeks. The external and internal egg quality were not significantly affected by the addition of PUFAs n-3 marine sources into the hen diets. The saturated : monounsaturated : polyunsaturated ratio (3.5:4.5:2.0) remained constant by the supplementation of the marine sources into the diets. The salmon oil and the tuna and sardine oil showed the best results of PUFAs n-3 egg yolk enrichment, mainly the DHA. The PUFAs n-6/PUFAs n-3 ratio was significantly reduced by the inclusion of PUFAs n-3 sources into the hen diets. The EPA, although with lower levels than DHA into the egg yolk, showed a significant increase by the use of salmon oil and tuna and sardine oil added to the diet as compared to the control group (CON). The consumption of two DHA enriched eggs from this study per day probably would reach the daily requirements of this PUFA n-3 for the human been
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Silva, Francisco Wilton de Freitas. "DFA e an?lise de agrupamento aplicadas a perfis de porosidade neutr?nico em po?os de petr?leo." Universidade Federal do Rio Grande do Norte, 2009. http://repositorio.ufrn.br:8080/jspui/handle/123456789/18534.
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Previous issue date: 2009-05-22?Peng was the first to work with the Technical DFA (Detrended Fluctuation Analysis), a tool capable of detecting auto-long-range correlation in time series with non-stationary. In this study, the technique of DFA is used to obtain the Hurst exponent (H) profile of the electric neutron porosity of the 52 oil wells in Namorado Field, located in the Campos Basin -Brazil. The purpose is to know if the Hurst exponent can be used to characterize spatial distribution of wells. Thus, we verify that the wells that have close values of H are spatially close together. In this work we used the method of hierarchical clustering and non-hierarchical clustering method (the k-mean method). Then compare the two methods to see which of the two provides the best result. From this, was the parameter ? (index neighborhood) which checks whether a data set generated by the k- average method, or at random, so in fact spatial patterns. High values of ? indicate that the data are aggregated, while low values of ? indicate that the data are scattered (no spatial correlation). Using the Monte Carlo method showed that combined data show a random distribution of ? below the empirical value. So the empirical evidence of H obtained from 52 wells are grouped geographically. By passing the data of standard curves with the results obtained by the k-mean, confirming that it is effective to correlate well in spatial distribution
Peng foi o primeiro a trabalhar com a T?cnica DFA (Detrended Fluctuation Analysis), uma ferramenta capaz de detectar auto-correla??o de longo alcance em s?ries temporais com n?o-estacionaridade. Nesse trabalho, a t?cnica de DFA ? utilizada para obter o expoente de Hurst (H) do perfil el?trico de Porosidade Neutr?nica dos 52 po?os petrol?feros Campo de Namorado, situado na Bacia de Campos ? RJ. A finalidade ? saber se o expoente de Hurst pode ou n?o ser usado para se caracterizar uma distribui??o espacial dos po?os. Assim, queremos verificar se os po?os que apresentam valores pr?ximos de H est?o espacialmente pr?ximos entre si. Neste trabalho foi utilizado o m?todo de agrupamento hier?rquico e o m?todo de agrupamento n?o hier?rquico (m?todo do k-m?dia). Em seguida comparamos os dois m?todos para ver qual dos dois fornece o melhor resultado. A partir disso, foi criado o par?metro (?ndice de vizinhan?a) o qual verifica se um conjunto de dados gerados pelo m?todo km?dia, ou de forma aleat?ria, forma de fato padr?es espaciais. Altos valores de indicam que os dados est?o agregados, enquanto que baixos valores de indicam que os dados est?o espalhados (sem correla??o espacial). Com aux?lio do m?todo de Monte Carlo observou-se que dados agrupados aleatoriamente apresentam uma distribui??o de inferior ao valor emp?rico. Portanto os dados emp?ricos de H obtidos dos 52 po?os est?o agrupados espacialmente. Ao cruzar os dados das curvas de n?vel com os resultados obtidos pelo k-m?dia, confirmam que este ? eficaz para correlacionar po?os em distribui??o espacial
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Silva, ?talo Batista da. "Compara??o da an?lise de diferentes perfis de po?os pelo m?todo DFA." Universidade Federal do Rio Grande do Norte, 2014. http://repositorio.ufrn.br:8080/jspui/handle/123456789/12988.
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Previous issue date: 2014-01-16The study of complex systems has become a prestigious area of science, although relatively young . Its importance was demonstrated by the diversity of applications that several studies have already provided to various fields such as biology , economics and Climatology . In physics , the approach of complex systems is creating paradigms that influence markedly the new methods , bringing to Statistical Physics problems macroscopic level no longer restricted to classical studies such as those of thermodynamics . The present work aims to make a comparison and verification of statistical data on clusters of profiles Sonic ( DT ) , Gamma Ray ( GR ) , induction ( ILD ) , neutron ( NPHI ) and density ( RHOB ) to be physical measured quantities during exploratory drilling of fundamental importance to locate , identify and characterize oil reservoirs . Software were used : Statistica , Matlab R2006a , Origin 6.1 and Fortran for comparison and verification of the data profiles of oil wells ceded the field Namorado School by ANP ( National Petroleum Agency ) . It was possible to demonstrate the importance of the DFA method and that it proved quite satisfactory in that work, coming to the conclusion that the data H ( Hurst exponent ) produce spatial data with greater congestion . Therefore , we find that it is possible to find spatial pattern using the Hurst coefficient . The profiles of 56 wells have confirmed the existence of spatial patterns of Hurst exponents , ie parameter B. The profile does not directly assessed catalogs verification of geological lithology , but reveals a non-random spatial distribution
O estudo dos sistemas complexos tornou-se uma ?rea prestigiada da ci?ncia, apesar de ser relativamente jovem. Sua import?ncia foi comprovada pela diversidade de aplica??es que v?rios estudos j? proporcionaram para campos diversos como os da Biologia, Economia e Climatologia. Na F?sica, a abordagem dos sistemas complexos vem criando paradigmas que influenciam de forma marcante os novos m?todos, trazendo para a F?sica Estat?stica problemas de n?vel macrosc?pico n?o mais restritos a estudos cl?ssicos como os da Termodin?mica. O presente trabalho tem como objetivo fazer uma compara??o e verifica??o dos aglomerados estat?sticos de dados relativos aos perfis de S?nico (DT), Raio Gama (GR), Indu??o (ILD), Neutr?nico (NPHI) e Densidade (RHOB) por serem grandezas f?sicas medidas durante a perfura??o de po?os explorat?rios de fundamental import?ncia para localizar, identificar e caracterizar reservat?rios de petr?leo. Foram utilizados os softwares: Statistica, Matlab R2006a, Origin 6.1 e Fortran para a compara??o e verifica??o dos dados dos perfis de po?os de petr?leo da Escola Campo Namorado cedidos pela ANP (Ag?ncia nacional de petr?leo). Foi poss?vel evidenciar a import?ncia do m?todo DFA e que o mesmo mostrou-se bastante satisfat?rio no referido trabalho, chegando-se a conclus?o que os dados do H (expoente de Hurst) produzem dados espaciais com uma maior aglomera??o. Portanto, constatamos que ? poss?vel encontrar padr?o espacial usando o coeficiente de Hurst. Os perfis dos 56 po?os comprovaram a exist?ncia de padr?es espaciais dos expoentes de Hurst, ou seja, par?metro B. O perfil avaliado n?o cataloga diretamente a verifica??o da litologia geol?gica, mas revela a exist?ncia de uma distribui??o espacial n?o aleat?ria
2024-12-31
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Xu, Bing. "Multidimensional approaches to performance evaluation of competing forecasting models." Thesis, University of Edinburgh, 2009. http://hdl.handle.net/1842/4081.
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The purpose of my research is to contribute to the field of forecasting from a methodological perspective as well as to the field of crude oil as an application area to test the performance of my methodological contributions and assess their merits. In sum, two main methodological contributions are presented. The first contribution consists of proposing a mathematical programming based approach, commonly referred to as Data Envelopment Analysis (DEA), as a multidimensional framework for relative performance evaluation of competing forecasting models or methods. As opposed to other performance measurement and evaluation frameworks, DEA allows one to identify the weaknesses of each model, as compared to the best one(s), and suggests ways to improve their overall performance. DEA is a generic framework and as such its implementation for a specific relative performance evaluation exercise requires a number of decisions to be made such as the choice of the units to be assessed, the choice of the relevant inputs and outputs to be used, and the choice of the appropriate models. In order to present and discuss how one might adapt this framework to measure and evaluate the relative performance of competing forecasting models, we first survey and classify the literature on performance criteria and their measures – including statistical tests – commonly used in evaluating and selecting forecasting models or methods. In sum, our classification will serve as a basis for the operationalisation of DEA. Finally, we test DEA performance in evaluating and selecting models to forecast crude oil prices. The second contribution consists of proposing a Multi-Criteria Decision Analysis (MCDA) based approach as a multidimensional framework for relative performance evaluation of the competing forecasting models or methods. In order to present and discuss how one might adapt such framework, we first revisit MCDA methodology, propose a revised methodological framework that consists of a sequential decision making process with feedback adjustment mechanisms, and provide guidelines as to how to operationalise it. Finally, we adapt such a methodological framework to address the problem of performance evaluation of competing forecasting models. For illustration purposes, we have chosen the forecasting of crude oil prices as an application area.
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Costa, Antonio Rufino da. "An?lise da efici?ncia de contratos de servi?os de elevada especificidade terceirizados pela petrobras." Universidade Federal do Rio Grande do Norte, 2013. http://repositorio.ufrn.br:8080/jspui/handle/123456789/12078.
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Previous issue date: 2013-07-05The definition of the boundaries of the firms is subject that has occupied the organizational theorists long ago, being the seminal work of Coase (1937) indicated as the trigger for one theoretical evolution, with emphasis on governance structures, which led to a modern theory of incomplete contracts. The Transaction Cost Economics (TCE) and Agency Theory arise within this evolution, being widely used in studies related to the theme. Empirically, data envelopment analysis (DEA) has established itself as a suitable tool for analysis of efficiency. Although TCE argues that specific assets must be internalized, recent studies outside the mainstream of theory show that, often, firms may decide, for various reasons, hire them on the market. Researches on transaction costs face with the unavailability of information and methodological difficulties in measuring their critical variables. There`s still the need for further methodological deepening. The theoretical framework includes classic works of TCE and Agency Theory, but also more recent works, outside the mainstream of TCE, which warn about the existence of strategies in use of specific assets that aren`t necessarily aligned with the classical ideas of TCE. The Brazilian oil industry is the focus of this thesis, that aimed to evaluate the efficiency of contracts involving high specificity service outsourced by Petrobras. In order to this, we made the categorization of outsourced services in terms of specificity, as well the description of services with higher specificity. Then, we verified the existence of relationship between the specificity of services and a number of variables, being found divergent results than those that are preached by the mainstream of TCE. Then, we designed a DEA model to analyze the efficiency in the use of onshore drilling rigs, identified among the services of highest specificity. The next step was the application of the model to evaluate the performance of drilling rigs contracts. Finally, we verified the existence of relationship between the efficiency of contracts and a number of variables, being found, again, results not consistent with the theory mainstream. Regarding to analyze of efficiency of drilling rigs contracts, the model developed is compatible with what is found in academic productions in efficiency of drilling rigs. The results on efficiency show a wide range of scores, with efficiencies ranging from 31.79% to 100%, being low the sample efficiency average. There is consonance between the model results and the practices adopted by Petrobras. The results strengthen the DEA as an important tool in studies of efficiency with possibility to use for analysis other types of contracts. In terms of theoretical findings, the results reinforce the arguments that there are situations in which the strategies of the organizations, in terms of use of assets and services of high specificity, do not necessarily follow what is recommended by the mainstream of TCE
A defini??o das fronteiras da firma ? tema que tem ocupado os te?ricos organizacionais h? bastante tempo, sendo o trabalho seminal de Coase (1937) apontado como desencadeador de uma evolu??o te?rica, com ?nfase nas estruturas de governan?a, que desemboca numa moderna teoria dos contratos incompletos. A Economia dos Custos de Transa??o (ECT) e a Teoria da Ag?ncia surgem dentro desta evolu??o, sendo bastante utilizadas em estudos associados ao tema. Empiricamente, a An?lise Envolt?ria de Dados (DEA) vem se firmando como ferramenta adequada para an?lises de efici?ncia. Embora a ECT argumente que ativos espec?ficos devam ser internalizados, estudos recentes fora do mainstream da teoria mostram que, muitas vezes, as firmas podem decidir, por motivos diversos, contrat?-los no mercado. As pesquisas sobre custos de transa??o deparam-se, com a indisponibilidade de informa??es e com dificuldades metodol?gicas para medi??o de suas vari?veis cr?ticas. Existe, ainda, a necessidade de aprofundamento metodol?gico. O referencial te?rico contempla trabalhos cl?ssicos da ECT e da Teoria da Ag?ncia, mas tamb?m trabalhos mais recentes, fora do mainstream da ECT, que alertam para a exist?ncia de estrat?gias no uso de ativos espec?ficos n?o necessariamente alinhadas com as ideias cl?ssicas da ECT. A ind?stria petrol?fera brasileira ? o foco da tese, que teve como objetivo avaliar a efici?ncia dos contratos de servi?os de elevada especificidade terceirizados pela Petrobras. Para tanto, foram feitas a categoriza??o dos servi?os terceirizados quanto ? especificidade e a descri??o dos servi?os de mais elevada especificidade. Na sequ?ncia, foi verificada a exist?ncia de rela??o entre a especificidade dos servi?os e uma s?rie de vari?veis, encontrando-se resultados divergentes do que prega o mainstream da ECT. Em seguida, foi elaborado um modelo DEA para an?lise de efici?ncia na utiliza??o de servi?os de sondas de perfura??o terrestres, identificado entre os de mais elevada especificidade. O passo seguinte foi a aplica??o do modelo para medi??o da efici?ncia dos contratos de sondas. Por fim, foi verificada a exist?ncia de rela??o entre a efici?ncia dos contratos e uma s?rie de vari?veis encontrando-se, mais uma vez, resultados n?o condizentes com o mainstream da teoria. No tocante ? an?lise de efici?ncia dos contratos de sonda, o modelo elaborado ? compat?vel com o que se encontra em produ??es acad?micas sobre efici?ncia de sondas. Os resultados quanto ? efici?ncia mostram um largo espectro de escores, com efici?ncias que variam de 31,79% a 100%, sendo baixa a efici?ncia m?dia da amostra. H? conson?ncia entre os resultados do modelo e as pr?ticas adotadas pela Petrobras. Os resultados refor?am a posi??o da DEA como ferramenta importante nos estudos de efici?ncia, com possibilidade de uso para an?lise de outros tipos de contratos. Em termos de achados te?ricos, os resultados refor?am os argumentos de que existem situa??es em que as estrat?gias das organiza??es, no que se referem ? utiliza??o de ativos e servi?os de elevada especificidade, n?o seguem necessariamente o que ? preconizado pelo mainstream da ECT
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Spiegelman, Dan. "Exploring the fusion of metagenomic library and DNA microarray technologies." Thesis, McGill University, 2006. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=98805.
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We explored the combination of metagenomic library and DNA microarray technologies into a single platform as a novel way to rapidly screen metagenomic libraries for genetic targets. In the "metagenomic microarray" system, metagenomic library clone DNA is printed on a microarray surface, and clones of interest are detected by hybridization to single-gene probes. This study represents the initial steps in the development of this technology. We constructed two 5,000-clone large-insert metagenomic libraries from two diesel-contaminated Arctic soil samples. We developed and optimized an automated fosmid purification protocol to rapidly-extract clone DNA in a high-throughput 96-well format. We then created a series of small prototype arrays to optimize various parameters of microarray printing and hybridization, to identify and resolve technical challenges, and to provide proof-of-principle of this novel application. Our results suggest that this method shows promise, but more experimentation must be done to establish the feasibility of this approach.
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Wang, Zhenyuan. "Artificial Intelligence Applications in the Diagnosis of Power Transformer Incipient Faults." Diss., Virginia Tech, 2000. http://hdl.handle.net/10919/28594.
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This dissertation is a systematic study of artificial intelligence (AI) applications for the diagnosis of power transformer incipient fault.
The AI techniques include artificial neural networks (ANN, or briefly neural networks - NN), expert systems, fuzzy systems and multivariate regression.
The fault diagnosis is based on dissolved gas-in-oil analysis (DGA). A literature review showed that the conventional fault diagnosis methods, i.e. the ratio methods (Rogers, Dornenburg and IEC) and the key gas method, have limitations such as the "no decision" problem. Various AI techniques may help solve the problems and present a better solution.
Based on the IEC 599 standard and industrial experiences, a knowledge-based inference engine for fault detection was developed. Using historical transformer failure data from an industrial partner, a multi-layer perceptron (MLP) modular neural network was identified as the best choice among several neural network architectures. Subsequently, the concept of a hybrid diagnosis was proposed and implemented, resulting in a combined neural network and expert system tool (the ANNEPS system) for power transformer incipient diagnosis. The abnormal condition screening process, as well as the principle and algorithms of combining the outputs of knowledge based and neural network based diagnosis, were proposed and implemented in the ANNEPS. Methods of fuzzy logic based transformer oil/paper insulation condition assessment, and estimation of oil sampling interval and maintenance recommendations, were also proposed and implemented.
Several methods of power transformer incipient fault location were investigated, and a 7Ã 21Ã 5 MLP network was identified as the best choice. Several methods for on-load tap changer (OLTC) coking diagnosis were also investigated, and a MLP based modular network was identified as the best choice. Logistic regression analysis was identified as a good auditor in neural network input pattern selection processes.
The above results can help developing better power transformer maintenance strategies, and serve as the basis of on-line DGA transformer monitors.Ph. D.
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Mata, Maria das Vit?rias Medeiros da. "An?lise de agrupamentos dos dados de DFA oriundos de perfis el?tricos de indu??o de po?os de petr?leo." Universidade Federal do Rio Grande do Norte, 2009. http://repositorio.ufrn.br:8080/jspui/handle/123456789/12902.
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Previous issue date: 2009-07-24The main objective of this study is to apply recently developed methods of physical-statistic to time series analysis, particularly in electrical induction s profiles of oil wells data, to study the petrophysical similarity of those wells in a spatial distribution. For this, we used the DFA method in order to know if we can or not use this technique to characterize spatially the fields. After obtain the DFA values for all wells, we applied clustering analysis. To do these tests we used the non-hierarchical method called K-means. Usually based on the Euclidean distance, the K-means consists in dividing the elements of a data matrix N in k groups, so that the similarities among elements belonging to different groups are the smallest possible. In order to test if a dataset generated by the K-means method or randomly generated datasets form spatial patterns, we created the parameter Ω (index of neighborhood). High values of Ω reveals more aggregated data and low values of Ω show scattered data or data without spatial correlation. Thus we concluded that data from the DFA of 54 wells are grouped and can be used to characterize spatial fields. Applying contour level technique we confirm the results obtained by the K-means, confirming that DFA is effective to perform spatial analysis
O principal objetivo do presente trabalho foi aplicar m?todos recentemente desenvolvidos em f?sica-estat?stica ?s s?ries temporais, em especial a dados de perfis el?tricos de indu??o de 54 po?os de petr?leo localizados no Campo de Namorado Bacia de Campos - RJ, para estudar a similaridade petrof?sica dos po?os numa distribui??o espacial. Para isto, utilizamos o m?todo do DFA com o intuito de saber se podemos, ou n?o, utilizar esta t?cnica para caracterizar espacialmente o campo. Depois de obtidos os valores de DFA para todos os po?os, fizemos uma an?lise de agrupamento com rela??o a estas caracter?sticas; para tanto, utilizamos o m?todo de agrupamento n?o-hier?rquico chamado m?todo K-m?dia. Geralmente baseado na dist?ncia euclidiana, o K-m?dia consiste em dividir os elementos de uma matriz n de dados em k grupos bem definidos, de maneira que as semelhan?as existentes entre elementos pertencentes a grupos distintos sejam as menores poss?veis. Com o objetivo de verificar se um conjunto de dados gerados pelo m?todo do K-m?dia ou gerado aleatoriamente forma padr?es espaciais, criamos o par?metro Ω (?ndice de vizinhan?a). Altos valores de Ω implicam em dados mais agregados e baixos valores de Ω em dados dispersos ou sem correla??o espacial. Com aux?lio do m?todo de Monte Carlo observamos que dados agrupados aleatoriamente apresentam uma distribui??o de Ω inferior ao valor emp?rico. Desta forma conclu?mos que os dados de DFA obtidos nos 54 po?os est?o agrupados e podem ser usados na caracteriza??o espacial de campos. Ao cruzar os dados das curvas de n?vel com os resultados obtidos pelo K-m?dia, confirmamos a efici?ncia do mesmo para correlacionar po?os em distribui??o espacial
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Melo, André de Souza. "Identificação de pontos quentes em transformadores de potência por meio de técnicas não invasivas." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/3/3143/tde-07112017-151817/.
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Esta pesquisa apresenta uma metodologia, baseada em duas técnicas não invasivas para identificação e diagnóstico de pontos quentes em transformadores de potência durante plena operação ou em fase de projeto. A primeira técnica é baseada na medição de radiação infravermelha, emitida pelo equipamento em funcionamento e registrada por meio de análise termográfica. A segunda técnica é possível a partir do conhecimento prévio das características construtivas do transformador, fazendo uso do Método dos Elementos Finitos (MEF). A segunda técnica pode ser validada a partir das medições realizadas utilizando a primeira técnica. A formação de gases no interior dos transformadores de potência, devido à elevação da temperatura do óleo isolante em função dos pontos quentes, é discutida em detalhes com base nas normas técnicas estabelecidas pelo IEEE e IEC. As técnicas e procedimentos abordados ao longo dessa pesquisa foram obtidos a partir de um transformador com potência nominal de 120 MVA e relação de tensão 13,8/230 kV, projetado para integrar uma fazenda eólica ao Sistema Interligado Nacional (SIN).This research presents a methodology based on two noninvasive techniques for identification and diagnostic of hot spots in power transformers during operation or project development. The first is based on measurements of infrared radiation from the equipment during operation and recording by thermography. The second technique is possible from the previous knowing of the constructive characteristics of the power transformer, by using the Finite Element Method (FEM). The second technique can be validated from measurements obtained using the first technique. The gas formation into the power transformers, because of the high temperatures in the insulating oil due to the hot spots, is discussed in details based on normative recommendations well established by the IEEE and IEC. All techniques and procedures to be approached in this research were obtained using a 120-MVA power transformer with voltage relationship of 13.8/230 kV that was projected to interconnect a wind farm to the Interconnected Brazilian System (Sistema Interligado Nacional - SIN).
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Romero, Llop Roberto. "Especificación OWL de una ontología para teleeducación en WEB semántica." Doctoral thesis, Universitat Politècnica de València, 2008. http://hdl.handle.net/10251/1828.
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Debido al gran desarrollo de la World Wide Web, tanto en cantidad de contenidos y nodos como en velocidades de acceso, aparecen por parte de la comunidad científico-técnica propuestas de utilización de la misma con objetivos más ambiciosos que la mera descarga de ficheros para ser presentados al usuario. Con esa finalidad se desarrolla la Web Semántica, sistema que pretende introducir información entendible por Agentes Inteligentes, permitiendo de este modo que estos Agentes puedan aumentar sus bases de conocimiento y realizar inferencias que faciliten procesos realizados actualmente de forma manual por los usuarios. De esta forma surgen los lenguajes ontológicos para la web, y en concreto el lenguaje recomendado por la World Wide Web Consortium (W3C) denominado Web Ontology Language (OWL), así como razonadores relacionados como FACT++, Racer y Pellet.
Además, con el objetivo de aprovechar el potencial de la web, se han ido generando gran cantidad de contenidos educativos, que debido a los altos costes de producción generan una necesidad de potenciar la reutilización de dichos contenidos. Aparece en este caso el concepto de objeto educativo, que es susceptible de ser reaprovechado para otras experiencias de aprendizaje, con alguna modificación o sin modificación alguna, generando la denominada interoperabilidad de objetos educativos.
El presente trabajo pretende potenciar esta interoperabilidad de objetos educativos. Para ello se especifica una ontología completa para teleeducación, basada en la lógica descriptiva y desarrollada en el lenguaje OWL, para que pueda ser utilizada por medio de la Web Semántica. Se estudian, desarrollan e implementan dentro de esta ontología conceptos relacionados con la interacción de los distintos agentes que intervienen en una experiencia de aprendizaje a través de la web.
La ontología presentada va además acompañada de una especificación de arquitectura de pares o Peer to Peer (P2P) basada en las arquitecturas de tablas de búsqueda distribuidas (DHTs), que denominaremos DHT Semántica. La DHT Semántica está diseñada para permitir la explotación por parte de Agentes Inteligentes de la ontología especificada, con una alta tolerancia a fallos en nodos de la arquitectura. Estos Agentes asisten en la búsqueda de objetos educativos más allá de la búsqueda por palabras claves. Finalmente, tanto la ontología como la arquitectura se validan utilizando un conjunto de experiencias educativas on-line reales.Romero Llop, R. (2007). Especificación OWL de una ontología para teleeducación en WEB semántica [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/1828
Palancia
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Barbosa, Fabio Rocha. "Monitoramento on-line e DiagnÃstico Inteligente da Qualidade DielÃtrica do Isolamento LÃquido de Transformadores de PotÃncia." Universidade Federal do CearÃ, 2012. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=8383.
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CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel SuperiorO monitoramento e o diagnÃstico de falhas incipientes em transformadores de potÃncia imersos em Ãleo estÃo diretamente relacionados à avaliaÃÃo das condiÃÃes do sistema de isolamento. Neste estudo, estabelece-se o conceito de monitoramento e diagnÃstico, e em seguida tÃcnicas de monitoramento on-line sÃo discutidas. Um sistema de prÃ-diagnÃstico à elaborado baseado na utilizaÃÃo de um dispositivo on-line de monitoramento, Hydran da GE, para classificar a gravidade da situaÃÃo de falha detectada. Uma vez detectada uma situaÃÃo de falha, mÃdulos inteligentes de diagnÃstico de falhas incipientes, via redes neurais, podem ser utilizados para identificaÃÃo da falha interna do equipamento. Para completar a verificaÃÃo da qualidade dielÃtrica do lÃquido isolante, tambÃm à descrito um algoritmo inteligente, baseado em redes neurais, para diagnÃstico do estado do Ãleo atravÃs das grandezas fÃsico-quÃmicas. A relaÃÃo entre os atributos fÃsico-quÃmicos e as grandezas cromatogrÃficas referente ao Ãleo mineral tambÃm foram averiguadas. Foi desenvolvida, entÃo, a estimaÃÃo dos gases dissolvidos atravÃs das caracterÃsticas fÃsico-quÃmicas. Os mÃdulos de monitoramento on-line, diagnÃsticos do estado do Ãleo e de falhas incipientes, alÃm da estimaÃÃo dos gases dissolvidos, perfazem um sistema computacional de auxÃlio à operaÃÃo e manutenÃÃo. O sistema implementado apresenta resultados satisfatÃrios na implantaÃÃo em uma planta de usina termelÃtrica.
The monitoring and diagnosis of incipient fault in power transformers immerses in oil are directly related to the assessment of the isolation system conditions. In this research, it is established the concept of monitoring and diagnosis, after that, on-line monitoring techniques are discussed. A pre-diagnosis system is elaborated based on use of a monitoring on-line device, Hydran GE, to classify the situation gravity of the detected fault. Once detected a fault situation, intelligent modules of incipient fault diagnosis, by neural networks, can be used to identification of internal fault of the equipment. To complete the checking of the dielectric quality of the isolate liquid, it is also described an intelligent algorithm, based on neural networks, to diagnosis of the oil estate through physical-chemical attribute. The relation between physical-chemical attributes and chromatographic ones regarding to mineral oil were also verified. It was developed, then, the dissolved gases esteem through physicalchemical characteristics. The on-line monitoring modules, diagnosis of oil estate and incipient fault, besides dissolved gases esteem, constitute a computation aid system to operation and maintenance. The implemented system presents satisfied results in a thermoelectric power plant.
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Casas, Godoy Leticia. "Lipase-catalyzed purification and functionalization of Omega-3 polyunsaturated fatty acids and production of structured lipids." Thesis, Toulouse, INSA, 2012. http://www.theses.fr/2012ISAT0057/document.
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Les lipases sont des enzymes présentant un grand intérêt industriel. L’intérêt de ces enzymes a conduit à caractériser ces enzymes, à mieux comprendre leur mécanisme réactionnel et leur cinétique, et à établir des méthodes efficaces de production en système d’expression homologue et hétérologue. Plus récemment, l’ingénierie enzymatique permet d’améliorer les caractéristiques des enzymes. Ce thèse s’est fixé deux objectifs principaux: premièrement, la purification et la fonctionnalisation d’acides gras poly-insaturés de type Omega-3 (PUFAs), et spécialement l’acide cis-4, 7, 10, 13, 16, 19-docosahexaénoique (DHA) et deuxièmement la production de lipides structurés (SL). Un premier objectif fut de produire une molécule pharmaceutique, le nicotinyl DHA ester. Le co-substrat du DHA est le nicotinol, un alcool qui après absorption, il est rapidement converti en acide nicotinique (Vitamine B3). La trans-esterification enzymatique entre l’ester éthylique du DHA et le nicotinol a été optimisée dans le but de synthétiser un ester présentant les propriétés cumulatives des deux réactants. Après la sélection de l’enzyme optimale (lipase immobilisée de Candida antarctica; Novozyme 435) et le choix du milieu réactionnel (milieu sans solvant), le procédé a été optimisé. Une conversion supérieure à 97 % a été obtenu en 4 heures avec 45 g.L-1 d’enzyme. Dans ces conditions, une productivité de 4.2 g de produit .h-1.g d’enzyme-1 a été obtenue. Ce projet nécessite une haute pureté en DHA. Un procédé de purification enzymatique a été choisi. Les lipases sont capables de discriminer entre les acides gras en fonction de la longueur de chaine et du degré d’insaturation. Les lipases agissent par résolution cinétique, en réagissant plus efficacement avec les acides gras saturés et mono-insaturés qu’avec les PUFAs résistants. La lipase YLL2 de Yarrowia lipolytica apparait comme un bon candidat car elle est homologue à une des lipases les plus efficaces, la lipase de Thermomyces lanuginosus. YLL2 a permis d’obtenir une discrimination très efficace. Les raisons de la sélectivité de l’enzyme ont été identifiées : il s’agit du positionnement de la double liaison la plus proche de la fonction carboxylique. La concentration en DHA la plus élevée a été obtenue avec YLL2 (73%) avec un pourcentage de récupération du DHA-EE de 89%. YLL2 est par conséquent l’enzyme décrite la plus efficace pour la purification du DHA.La mutagénèse ciblée dans le site actif de YLL2 a été utilisée pour améliorer la sélectivité de cette enzyme. L’analyse de la structure 3D et les alignements avec des lipases homologues a permis de choisir les cibles de mutagénèse dirigée. Les acides aminés cibles ont été changés de manière à restreindre ou élargir le site actif. De ce premier screening de variantes deux positions ont permis d’améliorer la spécificité de l’enzyme, les positions I100 et V235. Finalement la saturation de ces 2 positions a été réalisée. Le dernier objectif de la thèse était la production de SL par acidolysis enzymatique entre l'huile d'olive vierge et les acides caprylic ou capric utilisant la lipase YLL2 immobilisé. Le SL obtenu devrait être riche en acide oléique à la position sn-2 tandis que les C8:0 et C10:0 devraient être principalement estérifiés aux positions sn-1,3. YLL2 immobilisé sur Accurel 1000 a été testé dans un système sans solvant. La réaction d’acidolysis d'huile d'olive avec C8:0 ou C10:0 a été optimisée avec la méthodologie de surface de réponse (RSM)Lipases are enzymes with applications extended to a wide variety of industries. The variety of lipases applications led to increased research to characterize them and better understand their kinetics and reaction mechanisms and to establish methods for lipase production in homologous and heterologous expression systems. Lately enzymatic engineering allowed the improvement of lipase characteristics. This thesis project studies the use of lipases for two main objectives: lipase-catalyzed purification and functionalization of Omega-3 polyunsaturated fatty acids (PUFAs), especially cis-4, 7, 10, 13, 16, 19-docosahexaenoic acid (DHA) and production of structured lipids (SL). DHA was used for the synthesis of a pharmaceutical molecule, the nicotinyl DHA ester. The co-substrate of the reaction was nicotinol, an alcohol from the group B pro-vitamin, which after absorption is rapidly converted into nicotinic acid (Vitamin B3). The enzymatic trans-esterification of DHA ethyl esters with nicotinol was optimised to synthesise an ester presenting the cumulative properties of the two reactants. After enzyme (immobilized lipase from Candida antarctica; Novozym 435) and reaction medium (solvent-free system) selection, the process was optimised. A conversion to nicotinyl-DHA superior to 97 % was obtained in 4 hours using 45 g.L-1 of enzyme. With a productivity of 4.2 g of product .h-1.g of enzyme-1.This project requires DHA of high purity. Enzymatic purification was chosen for the production of DHA concentrates. Lipases can discriminate between fatty acids in function of their chain length and saturation degree. Lipases react more efficiently with the bulk of saturated and mono-unsaturated fatty acids than with the PUFAs. The objective was the discovery of more specific enzymes for DHA purification. The lipase Lip2 from Yarrowia lipolytica (YLL2) appears as a good candidate since it is homologous to one of the most efficient lipase, the lipase from Thermomyces lanuginosus. YLL2 enables a high discrimination to be obtained, enzyme selectivity being principally due to the positioning of the double-bond the closest from the carboxylic group. The highest concentration of DHA was obtained with YLL2 (73%) with a recovery percentage of DHA-EE of 89%. YLL2 is the most efficient described lipase for DHA purification.Site directed mutagenesis was used to improve YLL2 from Y. lipolytica. Using its three dimensional structure and alignment with homologous lipases, targets for site directed mutagenesis were chosen. Chosen amino acids were substituted by two amino acids of different sizes. From the screening of variants two positions with promising specificities where chosen, positions I100 and V235. Finally saturation of both positions and the analysis of their performances in the selected reactions were carried out. The last objective was the production of SL by enzymatic acidolysis between virgin olive oil and caprylic or capric acids using immobilized Lip2 from Y. lipolytica. The SL obtained should be rich in oleic acid at the sn-2 position while C8:0 and C10:0 should be mainly esterified at the sn-1,3 positions. Lip2 from Y. lipolytica immobilized on Accurel MP 1000 was tested in a solvent-free system. The acidolysis reaction of olive oil with C8:0 or C10:0 was optimized by response surface methodology (RSM)
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Janda, Ondřej. "Umělá inteligence v diagnostice výkonových olejových transformátorů." Doctoral thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2013. http://www.nusl.cz/ntk/nusl-234173.
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This dissertation thesis deals with the application of expert systems and soft computing methods in field of power oil transformers. The main work is divided into theoretical and practical part. First, the theoretical part presents the basic elements of the transformer, and approaches to its diagnosis. The work focused mainly on the diagnostics of the insulation system, and diagnostic methods and approaches in this specific area. Next part describes the basics of expert systems and other soft computing methods such as: fuzzy logic, neural networks, genetic algorithms and their combinations and extensions. At the end of the theoretical part, the possibility of optimization approaches by means of artificial intelligence and its application in fuzzy model optimization are described. The practical part begins with description of the used data file that runs through the entire work. The work is then divided into four parts, namely in parts which deal with the expert system for transformer diagnostics, DGA module, prediction module, and optimization using artificial intelligence. The section describing the expert system gives specific information about the particular expert system. The means and techniques used for constructing given system are described, and then the complete system design and description of all subsystems and modules are presented. The next section describes the developed DGA module and all selected approaches to its implementation and expansion. At the end of the chapter, the results of comparison between all implemented methods are evaluated. The third part deals with the prediction module and describes its design and construction, including description of the main parts which are based on the selected predictive approaches. Also, the predictions of selected quantities from the data file are included. There are two predictive approaches being used: the one step prediction, and the multiple step prediction. The comparison of prediction accuracy and computational cost of given methods is presented at the end of this chapter. The last part deals with the possibilities of optimization using artificial intelligence methods, namely differential evolution, PSO, and genetic algorithms. Both the single-objective and the multi-objective optimization are considered. The methods are compared in a series of synthetic tests and then applied to optimize the fuzzy models of DGA tests from an earlier part of this work. The dissertation also includes chapters: "The Aims", "The Contribution of the Work", and a list of publications, products, and projects of the author.
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Barbosa, Fabio Rocha. "DiagnÃstico de Falhas Incipientes a Partir das Propriedades FÃsico-QuÃmicas do Ãleo Isolantes em Transformadores de PotÃncia Como MÃtodo Alternativo à AnÃlise de Gases Dissolvidos." Universidade Federal do CearÃ, 2013. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=9189.
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CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel SuperiorO diagnÃstico de falhas incipientes em transformadores de potÃncia imersos em Ãleo està diretamente relacionado à avaliaÃÃo das condiÃÃes do sistema de isolamento. Este estudo aborda a relaÃÃo entre os gases dissolvidos no Ãleo e a qualidade do Ãleo mineral isolante utilizado em transformadores de potÃncia. As redes neurais artificiais sÃo utilizadas na abordagem da avaliaÃÃo das condiÃÃes operacionais do Ãleo isolante em transformadores de potÃncia, que à caracterizada por um comportamento dinÃmico nÃo-linear. As condiÃÃes de operaÃÃo e a integridade do sistema de isolamento de um transformador de potÃncia podem ser inferidas atravÃs das anÃlises fÃsico-quÃmicas e cromatogrÃficas (AnÃlise de GÃs Dissolvido). Estes ensaios permitem estabelecer procedimentos de operaÃÃo e manutenÃÃo do equipamento e normalmente sÃo realizados simultaneamente. Esta tese de doutorado propÃe um mÃtodo que pode ser usado para extrair informaÃÃes cromatogrÃficas usando as anÃlises fÃsico-quÃmicas atravÃs de redes neurais artificiais. As anÃlises atuais das propriedades fÃsico-quÃmicas fornecem apenas diagnÃstico do estado do Ãleo, o que nÃo permite o diagnÃstico de falhas incipientes. Acredita-se que, as concessionÃrias de energia podem melhorar a confiabilidade na previsÃo de falhas incipientes a um custo menor com este mÃtodo, uma vez que apenas um ensaio à necessÃrio. Os resultados mostraram que esta estratÃgia à promissora com mÃdia de acertos em diagnÃsticos de falhas maiores que 72%. O objetivo deste trabalho à a aplicaÃÃo direta do diagnÃstico de falhas incipientes atravÃs da utilizaÃÃo de propriedades fÃsico-quÃmicas, sem a necessidade de fazer uma cromatografia do Ãleo.
The diagnosis of incipient fault in power transformers immerses in oil are directly related to the assessment of the isolation system conditions. This search is about the relationship between dissolved gases and the quality of the insulating mineral oil used in power transformers. Artificial Neural Networks are used to approach operational conditions assessment issue of the insulating oil in power transformers, which is characterized by a nonlinear dynamic behavior. The operation conditions and integrity of a power transformer can be inferred by analysis of physicochemical and chromatographic (DGA â Dissolved Gas Analysis) profiles of the isolating oil. This tests allow establishing procedures for operating and maintaining the equipment and usually are performed simultaneously. This work proposes a method that can be used to extract chromatographic information using physicochemical analysis through Artificial Neural Networks. The present analysis of physicochemical properties only provide a diagnostic tool for the oil quality, which does not allow the diagnosis of incipient faults. ItÂs believed that, the power utilities could improve reliability in the prediction of incipient failures at a lower cost with this method, since only one test is required. The results show this strategy might be promising with an average accuracy for diagnosis of faults greater than 72%. The purpose of this work is the direct implementation of the diagnosis of incipient faults through the use of physicochemical properties without the need to make an oil chromatography.
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Colombo, Natália Beatriz Rigoldi. "Ação dos compostos antioxidantes na redução do estresse oxidativo em modelo experimental de câncer de pulmão: estudo do pequi (Caryocar brasilense camb)." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/5/5160/tde-27082014-092810/.
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Introdução. Uma alimentação rica em antioxidantes pode prevenir e reparar danos oxidativos causados pelas espécies reativas de nitrogênio e oxigênio, como o dano no DNA e a peroxidação lipídica e pode reduzir o risco de câncer, aterosclerose e outras doenças degenerativas. A polpa do Caryocar Brasiliense Camb, mais conhecido como pequi, é uma fruta do cerrado brasileiro que possui altos níveis de antioxidantes como os carotenóides, vitamina C e E e compostos fenólicos. Objetivos. Verificar a atividade antioxidante do óleo e do extrato da polpa do pequi na diminuição do estresse oxidativo em um modelo experimental de carcinogênese pulmonar. Métodos. O estudo foi realizado em 40 camundongos BALB/C machos: 35 animais foram submetidos a duas doses intra-peritoniais de 1,5 g/kg de uretana (U = 5), 10 destes camundongos receberam por gavagem 15uL de óleo da polpa do pequi (UO = 10), 10 animais receberam gavagem de 15uL de extrato etanólico de polpa de pequi (UE = 10) e os 10 animais restantes receberam por gavagem 3?g/kg de betacaroteno (UB = 10). 5 camundongos não receberam as doses de uretana nem a gavagem (C = 5). Após 60 dias, os grupos foram sacrificados. A defesa antioxidante enzimática foi mensurada pelo teste bioquímico. A atividade antioxidante do óleo de pequi foi avaliada nos tecidos do pulmão pelo teste bioquímico de TBARS (substâncias reativas ao ácido tiobarbitúrico) e os danos do DNA pelo método de teste de cometa. A expressão gênica e protéica das óxido nítrico sintases foi analisada por biologia molecular e imunohistoquímica, respectivamente. Resultados. O parênquima pulmonar dos animais que receberam as doses de uretana apresentaram formações neoplásicas induzidas pela carcinogênese química, em contraste com o grupo Controle. Os grupos de animais que receberam as doses de uretana e foram suplementados com o betacaroteno, o óleo e o extrato de pequi apresentaram resultados importantes na diminuição do dano no DNA, na peroxidação lipídica e na expressão protéica e gênica das isoformas da óxido nítrico sintase (NOS1, NOS2 e NOS3) ao contrário dos animais que receberam apenas as doses de uretana. Conclusão. Concluiu-se que os diferentes compostos antioxidantes encontrados no óleo e no extrato do pequi são eficientes para diminuir a expressão das enzimas óxido nítrico sintase, o dano no DNA e a peroxidação lipídica em um modelo experimental de carcinogênese pulmonar induzida pelo uretana, sugerindo que essa fruta possa contribuir no tratamento de câncer de pulmãoIntroduction. A daily consumption of foods that are rich in antioxidant compounds can prevent and repair the oxidative damage caused by reactive species of oxygen and nitrogen, such as DNA damage and lipid peroxidation and can reduce the risk of cancer, atherosclerosis and other degenerative diseases. The pulp of the Caryocar brasiliense camb, most known as pequi, has high levels of antioxidant compounds such as carotenoids, phenolic compounds and vitamin C and E. Objectives. Verify the antioxidant activity of the oil and extract of the pequi pulp in diminishing of the oxidative stress in an experimental model of lung cancer. Methods. The study was performed in 40 male BALB/c mices: 35 animals were submitted to two doses of 1,5g/kg intraperitoneal of urethane (U=5), 10 of these mices received by gavage 15uL of pequi pulp oil (UO=10), 10 animals received by gavage 15uL of ethanolic extract of pequi pulp (UE=10) and the other 10 animals received by gavage 3?g/kg of betacarotene (UB=10). 5 mices didn\'t receive the urethane doses neither the gavage (C=5). After 60 days, the groups were sacrificed. The enzymatic antioxidant defense was measured by biochemical test. The antioxidant activity of pequi oil was evaluated in the lung tissues by the biochemical TBARS test (Thiobarbituric acid-reactive substances) and the DNA damage by the comet test method. Nitric oxid Synthases gene and protein expression was analyzed by molecular biology and imunohistochemestry, respectively. Results. The pulmonary parenquima of animals that received the urethane doses showed neoplasic formations induced by the chemical carcinogenesis, in contrast with the control group. The groups of animals that received the urethane doses and the treatment with the oil, extract and betacarotene showed an important result in diminishing the DNA damage, lipid peroxidation, genic and protein expression of the nitric oxid synthase isoforms (NOS1,NOS2,NOS3), different from what we found in the group that just received the urethane doses. Conclusion. The different antioxidant components in the oil and extract of the pequi pulp are efficient to diminish the oxid nitric synthase isoforms, DNA damage and lipid peroxidation in an experimental model pulmonary chemical carcinogenesis, and suggest that the consumption of the fruit can be a good alternative to contribute in the treatment of lung cancer
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Maia, Mayara Cristina Mendes. "Mulheres ol?mpicas: cinema brasileiro, mulheres atletas e teoria feminista do cinema." Universidade Federal do Rio Grande do Norte, 2016. http://repositorio.ufrn.br/handle/123456789/21340.
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Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES)
Acreditamos que as recorrentes mudan?as do cinema cl?ssico, abrindo espa?o no cinema para o pensamento feminista, tem chegado ao Brasil de diferentes formas e com diversas tem?ticas fortemente dentro do cinema independente. Neste sentido, nossa pesquisa surge da necessidade de compreender as transforma??es sociais e na produ??o audiovisual sobre a mulher atleta e suas poss?veis rela??es com a Teoria Feminista do Cinema. Deste modo, nosso objetivo de trabalho foi analisar a obra cinematogr?fica brasileira ?Mulheres Ol?mpicas?, estabelecendo suas poss?veis rela??es com a teoria feminista do cinema. Realizamos uma an?lise contextual da obra atrav?s dos estudos de Gumbrecht. Nossas fichas t?cnicas de an?lise foram organizadas em dois momentos. O primeiro momento ? composto pelos objetos e pelas condi??es da experi?ncia est?tica do filme debatidos a partir dos elementos do texto f?lmico. O segundo momento, regido pelos conte?dos e efeitos da experi?ncia est?tica, est? dividido nas categorias que surgem partir da an?lise de conte?do de Bardin, a saber: desigualdade de sexo; desvaloriza??o da atleta; lutas pol?ticas e conquistas de espa?o; diferentes mulheres brasileiras; objetos e marcas simb?licos e; desconhecimento da hist?ria do esporte ol?mpico brasileiro. Ao estudarmos as categorias, conclu?mos que o document?rio n?o s? apresenta rela??es com a Teoria Feminista do Cinema, como retrata imagens de mulheres brasileiras atletas que h? muito tempo foram ofuscadas em sua visibilidade midi?tica e que, tribut?ria a emerg?ncia dessa teoria, ganham olhares mais generosos ? problematiza??o dos espa?os sociais ocupados pela mulher que predominam na obra.
Our research arises from the need to understand the social, and audiovisual production on the female athletes and their possible relationship with the Feminist Theory of Cinema. After conducting a survey of Brazilian works that address the theme of Brazilian female athlete by access Brazilian film libraries and the Internet, defined as a general goal of our work is to analyze the Brazilian cinematographic work "Mulheres Ol?mpicas", establishing their possible relationships with feminist theory cinema. We build a contextual analysis of the work through Gumbrecht studies. Our analysis of data sheets were organized in two stages. The first time was composed of objects and the conditions of the aesthetic experience of the film discussed from the filmic text elements. The second time, governed by the content and effects of the aesthetic experience, was divided into the categories that emerge from the Bardin content analysis, namely: sex inequality; devaluation of the athlete; political struggles and space conquests; different Brazilian women; objects and symbolic brands and; ignorance of the history of Brazilian Olympic sport. In studying the categories, we conclude that the documentary not only has relations with the Theory Feminist Cinema, as portrayed by images of women Brazilian athletes who have long been overshadowed by its media visibility and that tax the emergence of this theory, make more generous looks to problematize the social spaces occupied by women predominate in the work.
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Johnson, Michael Farley. "Cactus Hill, Rubis-Pearsall and Blueberry Hill : one is an accident; two is a coincidence; three is a pattern : predicting "old dirt" in the Nottoway river valley of Southeastern Virginia, USA." Thesis, University of Exeter, 2012. http://hdl.handle.net/10871/9541.
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This thesis covers more than thirty years of the author's research into the Paleoamerican period of the Middle Atlantic Region of North America, including the last 19+ years of focused work on the Cactus Hill site (44SX202) and replication of the Paleoamerican occupation discovered there. Using a landform and geology based predictive model derived from the Paleoamerican occupation at Cactus Hill, the author directed preliminary archaeological testing in three other areas of the same Nottoway River Valley, where Cactus Hill is located. These areas were the Barr site, located 11 miles (18 km.) downriver from Cactus Hill; the Chub Sandhill Natural Resource Conservation Area, located 19 miles (30 km.) downriver from Cactus Hill; and the Blueberry Hill site (44SX327), located approximately 1,000 feet (300 meters) east of Cactus Hill. The latter two produced OSL dated, pre-Younger-Dryas landforms, as predicted. The Rubis-Pearsall site (44SX360), located in the Chub Sandhill preserve also produced a buried Paleoamerican, Clovis age cultural level confirming the model. In addition to the OSL dates, Blueberry Hill also produced a distinct and apparently discrete activity surface with a possible pre-Clovis age Cactus Hill point at the same depth as the Paleoamerican levels at Cactus Hill and Rubis-Pearsall.
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Hanauer, André. "Le chromosome x humain : recherche de sequences exprimees et localisation genique de deux loci correspondanta des maladies." Université Louis Pasteur (Strasbourg) (1971-2008), 1989. http://www.theses.fr/1989STR13010.
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Caracterisation d'expressions geniques liees au chromosome x, de 6 sequences genomiques humaines liees au chromosome x; localisation du syndrome coffin-lowry par analyse de linkage et de la dysplasie ectodermique anhidrotique
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Centis, Sonia. "Transfert de fragments de genes d'un caulimovirus dans le colza (brassica napus l. ) : obtention de plantes transgeniques." Toulouse 3, 1988. http://www.theses.fr/1988TOU30198.
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Le virus de la mosaique du chou-fleur, representant modele des caulimovirus, comprend une molecule circulaire d'adn double brin d'organisation genetique connue. Des fragments de l'adn viral ont ete introduits dans le genome du colza, grace au vecteur naturel de transformation agrobacterium rhizogenes, afin de faire produire par la cellule vegetale un arn antisens permettant d'interferer avec l'expression d'un gene essentiel dans le cycle vital du virus. Des plantes transgeniques ont ete regenerees a partir des racines transformees
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Chen, Yu Ling, and 陳玉鈴. "Preparation of EPA/DHA Concentrate from Squid Visceral Oil." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/05867873909018442367.
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碩士國立臺灣大學
農業化學研究所
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The subject of this study is to investigate an efficient method for preparing high EPA/DHA content products from squid visceral oil as well as a method to remove cholesterol efficiently. We also study the storage stability of these high EPA/DHA content products and their glyceride derivatives. Firstly, we studied the suitable conditions for the hydrolysis of squid visceral oil to prepare the corresponded free fatty acids. It revealed that complete hydrolysis of the squid visceral oil could be carried out by saponification with NaOH at an amount of 1.2 times equivalent of the saponification value of the raw material in methanol, 95% ethanol or acetone. The acid value of hydrolysis product was around 178 mg KOH/ g oil. Besides, we also found that the same result could be obtained when saponification was carried out in 10 volumes of acetone at room temperature for 24 hours. We could obtain the high EPA/DHA product when it was neutralized with NaOH at an amount of 0.8 equivalent acid value in 5 volumes of acetone at room temperature for 1 hour. The content of EPA/DHA was 67.4% in the oil obtained from the supernatant. The precipitate was adjusted with hydrochloric acid and repeated the extractions twice as described above. The EPA/DHA content and recovery of the combined final materials was 57.2% and 90.9%, respectively. In additions, when the precipitate of saponification in acetone was extracted by acetone twice, the EPA/DHA contents of the supernatant and the two extracts (30 minutes) were 53.3%, 65.1%, and 45.1%, respectively. The recoveries were 36.0%, 13.2%, and 3.1%, respectively. The total recovery of EPA/DHA was 52.3%. The EPA/DHA content of the supernatant and two extracts (24 hours) were 72.0%, 62.8%, and 58.3%, respectively. The recoveries were 45.0%, 9.1%, and 3.9%, respectively. The total recovery of EPA/DHA was 58.0%. On the other hand, we found that the cholesterol in the hydrolysis products of squid visceral oil could be efficiently removed by flush silica gel column chromatography using n-hexane as the solvent. This method could remove 83.0% cholesterol from the hydrolysis products of squid visceral oil. And add cholesterol to raw squid visceral oil to cholesterol content was 1.0%, This method could dislodge 97.8% cholesterol from raw squid visceral oil. In this study, we also enzymatically converted the high EPA/DHA hydrolysis products to the glyceride derivatives, and compared their storage stabilities. We found that both Products were very stable, and the EPA/DHA contents decreased only slightly from 67.4% to 65.6% at 60℃after 10 days. Besides, we found that the natural antioxidants including Vit. E, ascorbyl palmitate, tea antioxidant and rosemary could significantly improve the storage stability of these high EPA/DHA p
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Zhan, De Ren, and 詹德仁. "Enrichment of EPA and DHA in squid visceral oil." Thesis, 1994. http://ndltd.ncl.edu.tw/handle/37346707426528567319.
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