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A comparative study of levels of methylglyoxal and reduced glutathione in different organs of rats treated with high carbohydrate diets2014 June 1900 (has links)
Methylglyoxal (MG) is a reactive dicarbonyl compound mainly formed during glucose and fructose metabolism. Diabetic patients have increased plasma levels of MG. Our laboratory has shown that treatment with MG induces insulin resistance and type II diabetes in male Sprague-Dawley rats. However, the increases in endogenous MG level attained in different organs and its contribution to the pathogenesis of diabetes following the administration of either high glucose or high fructose diet have not been addressed. The present study aims to investigate whether the harmful effects induced by increased consumption of glucose and/or fructose is linked to increased MG generation. In vitro studies have suggested that L-arginine is an effective MG scavenger. Accordingly, another goal is to determine whether L-arginine pretreatment would scavenge MG under in vivo setting and reduce the harmful effects of hyperglycemia. MG and reduced glutathione (GSH) levels were determined in plasma and urine and in different organs of male Sprague-Dawley rats after 12 weeks of treatment with either high fructose or high glucose diet. GSH plays an important role in the degradation of MG and bears an inverse relationship with the levels of MG. The key results obtained suggest that both diets significantly increased blood pressure and plasma MG levels. A high fructose but not a high glucose diet, increased the plasma total cholesterol, triglycerides levels and total cholesterol/HDL ratio in parallel with the increases in MG and GSH levels in the liver. Increased MG levels seen in both aorta and mesenteric artery induced by high glucose or fructose diet was attenuated by pretreatment with L-arginine. These findings suggest that elevated MG level induced by treatment with high carbohydrate diets in both conduit (aorta) and resistance type (mesneteric artery) vessels may be linked to endothelial dysfunction seen in hyerglycemic/diabetic states. High glucose but not high fructose diet significantly increased MG levels in the pancreas. This observation is consistent with the well-known glucotoxicity caused by hyperglycemia in the pancreas. Taken together, these data provide the first evidence that elevated MG levels in certain organs/tissues following consumption of high fructose and/or glucose diet(s) may play a critical role in contributing to the metabolic abnormalities and the endothelial dysfunction that precedes the onset of macro and microvascular complications in either hyperglycemic and/or type II diabetic states. Interestingly, quenching of elevated MG levels in tissues by pretreamtent with L-arginine overcomes MG-induced vascular damage and endothelial dysfunction caused by high fructose and high glucose diet regimens.
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Gerenciamento de res?duos s?lidos recicl?veis: estudo de caso das cooperativas do munic?pio de Natal/RNBispo, Cristina de Souza 20 September 2013 (has links)
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Previous issue date: 2013-09-20 / This dissertation conducted in the years 2011 and 2012, an analysis of cooperatives waste pickers in the city of Natal, Rio Grande do Norte, aiming to identify improvements to be implemented to assist the management of waste from the municipality as well as to improve the living conditions of the workers who perform the selective collection, the environmental perspective. This analysis was performed by means of an investigation of the reality in which they live cooperatives and their local representation, using also the law. The research is characterized as a case study of an applied nature, documentary, consultations with the institutions related to the issue of solid waste in the national and local levels; exploratory and descriptive, the main methodological tools technical visits and structured interviews. From these methods was possible to obtain data regarding the organization of cooperatives, environmental perception of the collector of recyclable materials, among other issues. For the analysis of data matrices were used to include comments and method GUT, from which it was possible to identify numerous difficulties faced by recycling cooperatives, and develop proposals for possible improvements in various aspects of their operation, such as infrastructure and production process , which can improve both the waste management and the quality of life of workers involved in the selective collection system city / A presente disserta??o realizou, nos anos de 2011 e 2012, uma an?lise das cooperativas de catadores de materiais recicl?veis da cidade de Natal, Rio Grande do Norte, tendo como objetivo identificar melhorias a serem implementadas para auxiliar o gerenciamento dos res?duos do munic?pio, bem como para a melhoria das condi??es de vida dos trabalhadores que realizam a coleta seletiva, na perspectiva socioambiental. Tal an?lise realizou-se por meio de uma investiga??o da realidade na qual vivem as cooperativas e de sua representatividade local, utilizando-se tamb?m da legisla??o vigente. A pesquisa caracteriza-se como um estudo de caso de natureza aplicada; documental, com consultas ?s institui??es relacionadas ? quest?o dos res?duos s?lidos nos cen?rio nacional e local; explorat?ria e descritiva, tendo como principais instrumentos metodol?gicos visitas t?cnicas e entrevistas semiestruturadas. A partir dos referidos m?todos foi poss?vel obter dados referentes ? organiza??o das cooperativas, percep??o ambiental do catador de materiais recicl?veis, entre outras quest?es. Para a an?lise dos dados foram utilizadas matrizes de inclus?o de coment?rios e o m?todo GUT, a partir dos quais foi poss?vel identificar in?meras dificuldades enfrentadas pelas cooperativas de catadores, al?m de elaborar propostas de poss?veis melhorias em diversos aspectos de seu funcionamento, como infraestrutura e processo produtivo, as quais possam aprimorar tanto a gest?o dos res?duos, quanto a qualidade de vida dos trabalhadores envolvidos no sistema de coleta seletiva municipal
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Mezidruhová kompetice a hostitelské spektrum entomopatogenních hlístovek (Steinernematidae, Nematoda) / Interspecific competition and host range of entomopathogenic nematodes (Steinernematidae, Nematoda)PŮŽA, Vladimír January 2009 (has links)
The presented thesis deals with interspecific competition and host range of entomopathogenic nematodes and assess the mechanisms enabling coexistence of multiple EPN species. The thesis further studied the scavenging ability of EPNs and their defense mechanisms against invertebrate scavengers. The results revealed that coexisting EPN species share the same niche and their interaction are complex and may be asymmetric. EPNs were found to be able to colonise and multiply in cadavers of different insects and scavenging seems to be an important alternative to normal infection. The defence of EPNs against scavengers seems to be an adaptation of the nematode-bacteria complex.
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The migration ecology of North American turkey vultures wintering in the Neotropics: spatial and population dynamicsNaveda-Rodríguez, Adrián José 08 December 2023 (has links) (PDF)
The spatial and population dynamics of avian scavengers are poorly understood. This information is key for management and conservation interventions that guarantee long-term species conservation. My goal in this dissertation is to fill information gaps on the movement ecology of New World vultures using the Turkey Vulture (Cathartes aura) as a model species. I used a continental-wide satellite telemetry dataset to study the migration ecology, space-use, and demography of the three North American breeding populations of Turkey Vultures wintering in the Neotropics during a 17-year period. I found that primary productivity, but not weather, triggered Turkey Vulture migratory behavior, migration initiated when primary productivity dropped at the end of the breeding and non-breeding season. Migratory connectivity was high at the species level (0.85, 95% CI: 0.74–0.94). However, I found evidence of intrapopulation segregation during the non-breeding season demonstrated by lower values of migratory connectivity in each population. I investigated how seasonality interacted with human disturbance, landscape composition and configuration to mediate patterns of geographic and environmental space-use, and annual and seasonal survival probabilities. Environmental space-use was best explained by landscape configuration. Geographic space-use exhibited a quadratic response to landscape configuration metrics, suggesting that Turkey Vultures maximize space-use in landscape with intermediate disturbance. Human disturbance, but not but not landscape composition and configuration, influenced survival rates in space and time. Overall annual survival averaged 0.87 (95% CI = 0.74 – 0.98). Mortality risk was low in western and central populations but was 3.7 times greater for vultures in the eastern population. Risk of mortality for all vulture populations increased with road density, and this was greater during the non-breeding and return migration seasons. My results suggest that spatial and population dynamics are affected at a continental scale by the energy landscape, intermediate disturbance and human disturbance. My dissertation emphasizes the importance of an integrative empirical-modeling approach to address questions on effects of resources availability and search efficiency in the spatial and population dynamics of avian scavengers.
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Synthesis and Characterization of New Active Barrier PolymersMahajan, Kamal 14 June 2010 (has links)
No description available.
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Efficacy of Odor Scavengers in Reducing Odor Compounds in Water, Milk, and SoymilkNorton, Jenny Lynn 14 October 2003 (has links)
Odor detection thresholds of hexanal, 2-heptenal, 2-pentanone, and 2,4-nonadienal were determined in spring water, high temperature short time (HTST) 2% fat milk, and extended shelf life soymilk. The efficacy of odor scavenger's beta-cyclodextrin, D-sorbitol, and nylon 6 in removing these odors was also determined. The odor thresholds of the different odor and media combinations were as follows: hexanal in spring water, milk, and soymilk were 585, 339, and 536 ppb respectively; 2-heptenal in spring water, milk, and soymilk were 2,092, 2,322, and 3,184 ppb respectively; 2-pentanone in spring water, milk and soymilk were 24,925, 29,255 and 33,271 ppb respectively; and 2,4-nonadienal in spring water, milk, and soymilk were 164, 326, and 243 ppb respectively. These amounts reference the initial spiked concentration that was added directly to the media. Both hexanal and 2,4-nonadienal had lower thresholds than 2-heptenal and 2-pentanone in all of the media. The odor detection thresholds of 2-heptenal, 2-pentanone, and 2,4-nonadienal did show a significant difference between soymilk and water, but not for milk. The efficacy of the odor scavengers were determined by use of solid phase micro-extraction gas chromatography (SPME-GC) and sensory evaluation. Hexanal, 2-heptenal, 2-pentanone, and 2,4-nonadienal were spiked at 1,000, 3,000, 30,000, and 300 ppb respectively in all three media. Beta-cyclodextrin, D-sorbitol, and nylon 6 were added at a level of 0.1% w/v and 1.0% w/v. In all of the media, beta-cyclodextrin was found to significantly reduce hexanal, 2-pentanone, 2-heptenal, and 2,4-nonadienal at both 0.1% w/v and 1.0% w/v. Nylon 6 was not found beneficial. / Master of Science
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Investigation of the nutraceutical potential of monofloral Indian mustard bee pollenKetkar, S.S., Rathore, A.S., Lohidasan, S., Rao, L., Paradkar, Anant R, Mahadik, K.R. January 2014 (has links)
No / This study was designed to investigate the nutraceutical potential of monofloral Indian mustard bee pollen (MIMBP). MThe nutritional value of MIMBP was examined in terms of proteins, fats, carbohydrates, and energy value. Its chemical composition in terms of total polyphenol and flavonoid content was determined. MIMBP was screened for free flavonoid aglycones by developing and validating a high-performance liquid chromatography-photo diode array (HPLC-PDA) method. MIMBP was analyzed for in vitro antioxidant effect in terms of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging activity. MIMBP was found to be comprised of proteins ((182.2+/-5.9) g/kg), fats ((137.7+/-6.8) g/kg) and carbohydrates ((560.6+/-17.4) g/kg), which result in its high energy value ((17 616.7+/-78.6) kJ/kg). MIMBP was found to contain polyphenols ((18 286.1+/-374.0) mg gallic acid equivalent/kg) and flavonoids ((1 223.5+/-53.1) mg quercetin equivalent/kg). The HPLC-PDA analysis revealed the presence of kaempferol ((65.4+/-0.5) mg/kg) and quercetin ((51.4+/-0.4) mg/kg) in MIMBP, which can be used as markers for determining the quality of bee pollen. The MIMBP extract showed DPPH free radical-scavenging activity with a half maximal inhibitory concentration of 54.79 mug/mL. The MIMBP was found to be a rich source of nutrients providing high caloric value, which makes it a candidate for a potential nutraceutical agent. The study also illustrated the high antioxidant content of MIMBP, especially in the principle polyphenols and flavonoids, which suggests its potential role in the prevention of free radical-implicated diseases. The DPPH-scavenging effect of MIMBP further confirmed its antioxidant potential. Additionally, we developed a simple, specific and accurate HPLC-PDA method for the identification and quantification of free flavonoid aglycones. This can be applied in future screenings of the quality of pollen collected by honeybees.
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<b>Accelerating oxygen depletion in hermetic storage using hand warmers to improve pest control</b>Wenbo Li (19337320) 06 August 2024 (has links)
<p dir="ltr">This study explores the use of hand warmers to enhance hermetic storage. Hand warmers work similarly to conventional oxygen scavengers by consuming oxygen through oxidation. This research aimed to determine how effective hand warmers are in accelerating oxygen reduction and insect mortality in hermetic storage, hence preserving grain quality. The experiments conducted in hermetic containers showed that hand warmers rapidly reduce oxygen levels, achieving insect-lethal conditions much faster than conventional oxygen absorbers like Oxy-Sorb. Our results show that hand warmers brought oxygen levels down to below 5% within 24-48 h and kept them low for an extended period up to 240 h. This quick oxygen depletion led to high insect mortality, reduced oviposition, and inhibited progeny development. Additionally, hand warmers did not negatively impact seed moisture content or germination rates, demonstrating their effectiveness in maintaining grain quality during storage.</p>
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Synthèse et Purification de matériaux à caractère cristal liquide à base de triphénylène pour leur utilisation dans des diodes électroluminescentes organiques.Roussel, Olivier C 07 September 2006 (has links)
Les diodes électroluminescentes organiques (OLED) ont une durée de vie limitée. Cette limitation est notamment due à la présence d'impuretés dans le matériau électroluminescent. Ces impuretés proviennent principalement des électrodes. Nous pensons que l'ajout de couches de matériaux entre les électrodes et le matériau électroluminescent peut retarder l'arrivée des impuretés. Cette couche ajoutée doit avoir plusieurs caractéristiques dont principalement : être conductrice, ne pas absorber la lumière, être facilement mise en oeuvre et être d'une grande pureté. Nous pensons que des matériaux de type discotique possédant une mésophase aux températures d'utilisation de la OLED peuvent remplir ce cahier des charges.
Nous avons choisi d'étudier les composés discotiques à base de triphénylène, car celui-ci n'absorbe pas dans le visible. Nous avons tout d'abord étudié les 2,3,6,7,10,11-Hexa-(alkylthio)triphénylènes (HATT). Les HATT possèdent déjà les propriétés physiques que nous recherchons à l'exception des propriétés thermotropes. Nous avons donc étudié la possibilité de modifier celles-ci.
La synthèse de plusieurs HATT possédant six chaînes alkylsulfanyles identiques n'a pas donné les résultats attendus du point de vue des propriétés thermotropes. Nous avons alors synthétisé des molécules possédant plusieurs chaînes alkylsulfanyles différentes. Après différents essais, nous avons trouvé un mélange de molécules possédant plusieurs chaînes latérales différentes ayant les propriétés physiques recherchées. Mais ce matériau est composé d'un grand nombre de molécules et sa purification est difficile. Les techniques classiques de purification des composés organiques ne donnant pas une pureté suffisante, ou étant inapplicables sur une mésophase cristal liquide à température ambiante, nous avons donc recherché d'autres techniques de purification ou d'obtention des propriétés thermotropes désirées.
Nous avons étudié la purification par raffinage de zone des matériaux à l'aide d'une impureté que nous avons ajoutée et suivie au cours des manipulations. Le raffinage de zone montre une bonne purification lors de l'utilisation d'une transition de phase entre une phase cristalline et une phase liquide. Par contre, lors de l'utilisation d'une transition impliquant une mésophase (cristal liquide ou cristal plastique), une faible (ou une absence de) purification est observée. Ces deux dernières études ont été faites sur des 2,3,6,7,10,11-Hexa(alkyloxy)triphénylènes (HAOT) que nous avons synthétisés et purifiés au préalable.
Les gels de silice fonctionnalisés que nous avons utilisés montrent une purification des cations métalliques durs et, dans une moindre mesure, des cations métalliques intermédiaires dans le concept dur-mou. Le phosphore, seul élément non-métallique que nous ayons étudié, est l'élément dont la baisse de concentration est la moins efficace.
La seconde approche pour obtenir des mélanges possédant une mésophase cristal liquide à température ambiante est la formation de mélanges de molécules synthétisées et purifiées isolément. Parmi les mélanges de molécules que nous avons effectués, nous avons pu observer une plage de concentration de mélanges ternaires qui possède les propriétés thermotropes recherchées.
Nous avons donc obtenu un matériau cristal liquide à température ambiante grâce à un mélange de molécules. Le matériau ainsi formé absorbe peu dans le visible, possède potentiellement une bonne mobilité des porteurs de charges électriques, est facilement obtenu à une pureté suffisante. Ce mélange de molécules possède donc les propriétés que nous recherchons pour être utilisé comme couche de matériau ajoutée aux OLED.
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No lixo? Na Arte?: um estudo da consciência política dos sujeitos participantes em empreendimentos de economia solidária em Tangará da Serra-MTJunior, Wilson Luconi 29 April 2011 (has links)
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Previous issue date: 2011-04-29 / FAPEMAT - Fundação de Amparo à Pesquisa do Estado de Mato Grosso / A dissertação discute a economia solidária com foco na consciência política dos sujeitos participantes nos empreendimentos solidários, dos segmentos de coleta e separação de resíduos sólidos e artesanato. Descreve e analisa elementos da consciência política, através de sete dimensões, conforme proposto por Sandoval (1994), sendo elas: identidade coletiva; crenças, valores e expectativas; interesses antagônicos e adversários, eficácia política; sentimentos de justiça e injustiça; vontade de agir coletivamente e ações e objetivos do movimento social. Para contribuir nesta discussão foram apresentadas articulações teóricas sobre a economia solidária, a compreensão do sujeito, movimentos sociais e consciência política. A pesquisa consiste em um estudo de caso de cunho exploratório, cujos dados foram coletados por meio de entrevistas individuais, grupos focais e observações do pesquisador. Os empreendimentos selecionados foram: Coopertan - Cooperativa de Produção de Material Reciclável de Tangará da Serra-MT e a Artetan - Associação dos Artesões de Tangará da Serra-MT. A análise consistiu em categorizar os discursos dos sujeitos através das dimensões da consciência política. Os resultados apontam que os empreendimentos são um espaço possível de politizar a sobrevivência através da prática da autogestão e da formação que ela demanda; que as identidades em geral são construídas através de relações de parentesco e de liberdade no trabalho e que a luta dos cooperados é contra o sistema capitalista que os exclui do mercado de trabalho. Indicam também que eles encontram, nos espaços do empreendimento, significativo apoio e solidariedade. Esse trabalho, que compartilha da própria vida, evidenciou aspectos da formação política engendrada na esfera do trabalho, ou seja, uma politização da e para a sobrevivência. / The dissertation discusses the solidary economy with focus on political awareness of individual participants in the social economy enterprises. It describes and analyzes this political consciousness through seven dimensions as proposed by Sandoval (1994), like: the collective identity issue; beliefs, values and expectations; conflicting interests and opponents; political effectiveness; justice and injustice feelings; wish of acting collectively and the social movement actions and aims. It was presented some theoretical articulations of the solidarity economy to contribute to this discussion, the question on the understanding of the subjetct, some theories on social movements and, finally, on political consciousness. The research consists in an exploratory case study, whose data were collected through individual interviews, focus groups and observations. The selected groups were: Coopertan - Production Cooperative of Recyclable Material of Tangara da Serra, MT and Artetan - Craftsmen Association of Tangara-MT. The analysis consisted of categorizing the speeches by the dimensions of the political consciousness. The results indicate that the enterprises are a possible space of politicizing the survival, through self-management and training; identities are often constructed through relations of kinship and freedom at work and the struggle of cooperative members is against the capitalist system, that excludes them from the labor market. Also indicate there are, in enterprises, spaces of support and solidarity. This essay which shares the own life has presented policy formation aspects, i.e., a politicization of and for the survival.
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