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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
111

Expanding the genetic variability of flatpea using tissue culture, mutagenesis, and intercrossing techniques

Coulombe, Bruce Armand January 1988 (has links)
Flatpea (Lathyrgs sylvestris L.) is a potentially valuable forage legume but contains high levels of 2,4-diaminobutyric acid (DABA), a compound that can have adverse effects on some animals, including rats and poultry. To increase genetic variability in foliar DABA content and other traits of interest, three approaches were utilized: (1) regeneration of flatpea plants from tissue culture to produce potential somaclonal variants, (2) seed irradiation and screening of potentially mutated progeny, and (3) intercrossing among flatpea accessions. Low-frequency whole plant regeneration of flatpea was obtained from hypocotyl-derived callus cultures. Auxin concentrations above 5.0 µM resulted primarily in root formation without shoots. Conditions for optimum whole plant regeneration were as follows: callus was initiated on a modified Schenk-Hildebrandt low-ammonium medium containing 5.0 µM IAA (indole acetic acid) and 2.5 µM zeatin for callus initiation; after two subcultures, calli were transferred to a regeneration medium containing 0.1 µM IAA and 1.0 µM zeatin. Calli and regenerated root tissue contained 47 and 381 as much DABA as leaf tissue from 'Lathco' flatpea plants, respectively. Initial tests established that the effective range of gamma irradiation for seed treatment was between 10.0 and 17.5 kR. Within this range, reduction in percentage of both seedling height and plant survival was a linear function of dose. Individual M₂ plants that contained reduced levels of DABA were identified. No significant trend in DABA concentration with increasing gamma irradiation was apparent. Flatpea pollination methods were evaluated prior to utilization of intercrossing for inducing genetic variability. Appropriate flower stages for emasculation were determined by in vitro germination of pollen. Lines that produced high numbers of seeds per pollination were identified by crossing in all possible combinations among seven flatpea accessions. Cross-pollinations resulted in significantly higher seed set than selfing. Pollination using caged honeybees was the most efficient method of hybridization. Greater range and coefficient of variation in DABA concentration were observed for flatpea accessions than for intercrossed progeny produced by honeybee pollination. / Ph. D.
112

A CONTRIBUIÇÃO DA FORMAÇÃO CONTINUADA PARA AS PROFESSORAS DE EDUCAÇÃO INFANTIL DO MUNICÍPIO DE SÃO PAULO / Early childhood education teacher working in state schools belonging to the São Paulo municipality network

Sales, Cintia de Cássia Silva 19 May 2015 (has links)
Made available in DSpace on 2016-08-03T16:15:51Z (GMT). No. of bitstreams: 1 CintiaSales2.pdf: 907172 bytes, checksum: 68b2a0f08bcccbc59f4428b1d3d50a90 (MD5) Previous issue date: 2015-05-19 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This research addresses the ongoing education of Early Childhood Education teachers working in state schools belonging to the São Paulo Municipality network. The central question to be investigated is the contributions made by the proposal for ongoing education offered by the São Paulo City Board of Education to the referred teachers. The study was carried out based on the perception of the importance of ongoing education as a path and an exercise of self-reflection that enables the redefinition of the teacher s identity considering his/her historical construction process. This segment of education was chosen because several contemporary authors such as Beatrice Cerisara, Patricia Prado, Zeila Demartini, Júlia Formosinho and João Oliveira-Formosinho, among others, consider it an essential phase in which the dichotomy between care and education, as well as the identity of the teacher as an Educator, must be continually discussed. In this sense, this research first presents a theoretical discussion about Early Childhood Education teacher training in Brazil, concluding with a field research that evaluates the Strategic Action Project (PEA in Portuguese) as one of the proposals of ongoing training for Early Childhood Education teachers. The field research was carried out by means of semi-structured interviews with nine teachers from that municipal network. The research confirmed the relevance of PEA for the ongoing education of the teachers interviewed. The study also found that this project has been positively and significantly modified and improved with actions directed to the specific needs of Early Childhood Education, which conceive the child as a subject of right, who has a voice and many competences. The research also observed how PEA contributes to the ongoing education when, in collective moments, it allows peer exchange and the consequent reflection about their practices, helping teachers to became more autonomous, aware of their important role as mediators of the child learning construction process. / Esta pesquisa aborda a formação continuada das educadoras da Educação Infantil da rede pública municipal de São Paulo. A questão central a ser investigada refere-se à proposta de formação continuada oferecida pela Secretaria Municipal de Educação de São Paulo SMESP buscando pesquisar quais são as contribuições desse projeto para essas educadoras. O estudo foi desenvolvido a partir da percepção da importância da formação continuada como um caminho de ressignificação da identidade docente e um exercício reflexivo para as professoras desse segmento da educação considerando todo o seu processo de construção histórica. Tal segmento foi escolhido para esta pesquisa, pois estudos contemporâneos realizados por diversos autores tais como: Beatriz Cerisara, Patricia Prado, Zeila Demartini, Júlia Formosinho e João Oliveira-Formosinho, entre outros, consideram que essa é uma fase essencial, na qual está sempre presente a necessidade de se discutir a dicotomia entre o cuidar e o educar, e de se ressignificar a identidade das professoras enquanto profissionais de Educação Infantil. Nesse sentido, a pesquisa apresenta uma discussão teórica acerca da formação das professoras da Educação Infantil no Brasil finalizando com uma pesquisa de campo que avalia o Projeto Estratégico de Ação PEA -, como uma das propostas de formação continuada das professoras de Educação Infantil, por meio de entrevistas semiestruturadas realizadas com nove professoras da Educação Infantil dessa rede municipal. A pesquisa possibilitou observar a relevância do PEA para as professoras entrevistadas, no que diz respeito à formação continuada. O estudo constatou também que este projeto vem sendo alterado de forma positiva e significativa, a partir de ações direcionadas às necessidades específicas da Educação Infantil, com uma concepção sobre a criança como um sujeito de direito à voz e dotado de competências. Nesta pesquisa, como possibilidade de formação, observou-se ainda a contribuição do PEA, que em momentos coletivos, permite a troca entre os pares e a reflexão sobre suas práticas, tornando-as professoras mais autônomas em seu papel enquanto parte do processo de construção de aprendizagem pela criança.
113

Quête et construction identitaires dans l’œuvre autobiographique de Enrico Pea (1881-1958) / Identity search and construction in Enrico Pea’s (1881-1958) autobiografical work

Fabrèges, Mélody 10 December 2012 (has links)
Auteur autodidacte, Enrico Pea (1881-1958), romancier, nouvelliste, poète et auteur dramatique, est une figure atypique dans le paysage littéraire italien du XXe siècle. Une partie de l’œuvre narrative de Pea est caractérisée par sa dimension autobiographique qui n’efface cependant pas une tendance à composer ses œuvres par fragments. Nous proposons, dans cette thèse, de nous concentrer sur cinq œuvres de Enrico Pea, toutes caractérisées par leur dimension fragmentaire, qui représentent autant d’étapes dans sa construction identitaire et d’envisager ainsi, la dimension fragmentaire par le prisme du morcellement du « je » narratif. Fole (1910) est un recueil de contes et légendes de sa terre natale. Moscardino (1922), Il Volto Santo (1924) et Il servitore del Diavolo (1931) sont des œuvres autobiographiques en prose. Dans Moscardino et Il Volto Santo, le narrateur raconte l’histoire de sa famille et son enfance en Versilia auprès de son grand-père. Il servitore del Diavolo est une autobiographie en creux retraçant dans un climat fantasmagorique les années égyptiennes de l’auteur. Enrico Pea se tourne une nouvelle fois vers l’autobiographie vers la fin de sa carrière pour évoquer à nouveau le séjour égyptien dans Vita in Egitto (1949). Cette étude entend montrer que l’œuvre autobiographique de Enrico Pea, à travers la création du personnage de Pea-Moscardino, retrace les étapes de la construction identitaire de l’auteur mais également propose une autobiographie idéale reposant sur le mythe de l’écrivain autodidacte. Ce parcours s’accompagne d’une réflexion de l’auteur sur l’écriture autobiographique qui converge vers la définition d’une poétique de l’autobiographie. / Self-taught author Enrico Pea (1881-1958) was a novelist, short story writer, poet, playwright and is an unusual figure of the twentieth century Italian literary scene. Part of Pea’s narrative work is characterized by its autobiographical dimension which maintains however a tendency to be created in fragments. This thesis will focus on five pieces of work by Enrico Pea, all characterized by their fragmentary dimension and representing many steps in the construction of his identity. Therefore it considers this dimension gradually through the prism of fragmentation of the narrative "I". Fole (1910) is a collection of tales and legends from his homeland. Moscardino (1922), Il Volto Santo (1924) and Il servitore del Diavolo (1931) are autobiographical works in prose. In Moscardino and Il Volto Santo, the narrator tells the story of his family and childhood in Versilia with his grandfather. Il servitore del Diavolo is an autobiography subtly depicting the author’s Egyptian years in a dreamy climate. Enrico Pea uses the autobiography again towards the end of his career to portray once more his stay in Egypt in Vita in Egitto (1949). This study aims to show that Enrico Pea’s autobiographical work, through the creation of the character Pea-Moscardino, retraces the steps of the author’s self-identity construction, but also provides an ideal autobiography based on the myth of the self-taught writer. This work is accompanied by a reflection from the author on autobiographical writing and converges towards a definition of the poetics of autobiography.
114

Betydelsen av rapportskrivning : Gymnasieelevers frågor och språkanvändning vid diskussion om kemisk bindning / The significance of writing reports : High School students’ questions and language in discussion about chemical bonding

Kristiansen, Susann January 2018 (has links)
Vid ett laborativt arbete i undervisningen får eleverna möjlighet att samtala med varandra och dela med sig av tidigare erfarenheter, vilket har en positiv effekt på elevernas lärande. Att skriva i undervisningen har också visat sig ha en stor effekt på elevernas lärande, då de får utveckla och strukturera om sina tankar. Syftet med denna studie har varit att undersöka hur elevernas kunskap inom kemisk bindning utvecklas, samt hur elevernas språk utvecklas vid kursmoment med laborativt inslag och laborationsrapportskrivning. För att undersöka detta har kommunikationen hos fyra elever, som gick första året på gymnasiet och läste kemi, spelats in och sedan transkriberats, när eleverna genomförde och efteråt presenterade en laboration. Det här materialet tillsammans med elevernas laborationsrapporter blev sedan analyserade dels med PEA, dels med fokus på ämnesspråk och vardagsspråk. Resultatet visar att under alla delar i kursmomenten finns det ett fokus på laborationsrapporten och hur den ska skrivas där eleverna får möjlighet att utveckla sina kunskaper inom kemisk bindning samt utveckla sitt ämnesspråk. / Laboratory work in science education gives students opportunity to have a conversation and share knowledge with other classmates, which have a positive effect on students learning. To be able to communicate by writing in science education, has also been proven to have an enhanced the learning process by helping students to organized and challenged their thoughts. Therefore, this study objective is to explore how students’ knowledge about chemical bonding and their scientific language develops with laboratory work and laboratory report writing. To explore this, the communication of four students in their first year of high school, studying chemistry were recorded and later transcribed, while they performed and afterwards presented a lab. This material together with the students’ final laboratory report has been analyzed with regards to PEA and the language used by students. The study indicates that the use of laboratory report writing has helped students to develop their knowledge about chemical bonding, but also their scientific language.
115

Caractérisation moléculaire et phénotypique d’un mutant dpp3Δ défectif pour une pyrophosphate phosphatase chez la levure opportuniste Candida lusitaniae : étude de l’interaction des levures avec l’hôte / Molecular and phenotypic characterization of a dpp3Δ knocked-out mutant, lacking a pyrophosphate phosphatase, in the opportunistic yeast Candida lusitaniae : a study on the interaction of yeasts with the host

Sabra, Ayman 12 November 2013 (has links)
Candida lusitaniae est une levure pathogène opportuniste émergente, responsable d’infections sévères chez les sujets immunodéprimés, et constitue un important modèle d’étude fonctionnelle de gènes par génétique inverse. Cette levure est souvent associée à des résistances aux antifongiques, d’où la nécessité de mieux comprendre l’interaction entre l’hôte et le pathogène, afin d’identifier de nouvelles cibles thérapeutiques potentielles. Les molécules signal sont décrites comme modulatrices de cette interaction. Au cours de ce travail, nous avons créé un mutant dpp3Δ, inactivé pour une pyrophosphate phosphatase, chez C. lusitaniae. La mutation a pour conséquence de modifier le taux secrété de PEA/tyrosol, des alcools aromatiques récemment décrits comme molécules signal chez les espèces Candida. Les levures du mutant dpp3Δ présentent aussi un défaut de pseudo-filamentation et de reproduction sexuée. Comparé à la souche sauvage, le mutant dpp3Δ module différemment la réponse macrophagique, notamment la production de NO et ROS, ainsi que la sécrétion de TNF-α et d’IL-10. Curieusement, la sécrétion d’IL-10 est modulée par les levures même sans contact physique avec les macrophages. Par ailleurs, nous avons observé des effets du traitement des levures par le PEA ou le tyrosol sur la modification des réponses immunes macrophagiques. Enfin, nous avons montré que le gène DPP3 chez C. lusitaniae était un facteur de virulence essentiel dans des modèles murins d’infection, et qu’il augmentait le taux de TNF-α secrété et la colonisation des cerveaux. / C. lusitaniae, an emerging Candida species often associated with antifungal resistance, is an important model to study gene function by reverse genetics. Understanding the host-pathogen interaction helps identifying new virulence factors and potentially new antifungal targets. Signaling molecules are often reported as modulators of this interaction. Here we created a dpp3Δ knocked-out mutant, lacking a pyrophosphate phosphatase, in C. lusitaniae. This mutation modified the ratio of secreted PEA/tyrosol, two newly reported signaling molecules in Candida species. Colony morphology of yeast cells was also altered as yeasts had a defect in pseudo-filamentation, and mating capacity was severely reduced. Compared to the wild-type strain, the dpp3Δ knocked-out mutant differently affected NO and ROS production by macrophages as well as TNF-α and IL-10 secretion. Interestingly IL-10 secretion was found to be modulated by C. lusitaniae without the need of a physical contact with the phagocytes. Moreover we elucidated the effects of PEA and tyrosol on yeast cells leading to modulations in macrophage immune responses. At last, the DPP3 gene was found to be an essential pathogenicity factor in mice models, leading to an increase of TNF-α secretion and brain colonization.
116

Caractérisation de l'axe intégrine α5β1/protéine p53 dans les gliobastomes humains : application à une thérapie ciblée anti-tumorale / Characterization of the α5β1 integrin / p53 protein axis in human glioblastoma : application to a targeted anti-cancer therapy

Renner, Guillaume 30 September 2016 (has links)
Les intégrines sont des protéines transmembranaires, formées d’une sous-unité α et d’une sous-unité β, qui sont impliquées dans de nombreuses caractéristiques du cancer. Mes travaux de thèses ont montré que l’axe intégrine α5β1/AKT est impliqué dans la résistance à l’apoptose des cellules de glioblastome et dans leur migration. L’inhibition fonctionnelle de l’intégrine α5β1 associée à la réactivation de p53 sensibilise les cellules de glioblastome à l’apoptose. Mes résultats ont mis en évidence que les protéines anti-apoptotiques PEA-15 et Survivine sont deux intervenants majeurs dans cette résistance à l’apoptose. La migration dépendante de l’intégrine α5β1 implique la β-caténine. Les résultats obtenus par ce travail de thèse, donnent, par conséquent, des arguments supplémentaires en faveur de l’implication de l’intégrine α5β1 dans l’agressivité des glioblastomes. Ces résultats permettent également de proposer de nouvelles cibles thérapeutiques ainsi que des biomarqueurs pertinents pour stratifier les patients potentiellement répondeurs à une stratégie anti-intégrine. / Integrins are αβ membrane localised protein heterodimers involved in numerous hallmarks of cancer. My PhD thesis showed that the integrin α5β1/AKT axis is implicated in glioblastoma cells resistance to apoptosis and migration. The inhibition of α5β1 integrin oncogenic pathway sensitizes glioma cells to p53-reactivation dependent apoptotic cues. My results showed that PEA-15 and Survivin are two anti-apoptotic proteins involved in the resistance to apoptosis. α5β1 integrin dependent migration involves the β-catenin pathway. My results confirm that α5β1 integrin has to be considered as an important player in glioblastoma aggressiveness and resistance to therapy. The results of my thesis also suggest new therapeutic targets and pertinent biomarkers for glioblastoma patient stratification.
117

Novel approaches for the chromatographic and electrophoretic separation of molecules

Meyer, Amanda R. January 1900 (has links)
Doctor of Philosophy / Department of Chemistry / Christopher T. Culbertson / High-performance liquid chromatography (HPLC) and capillary electrophoresis (CE) are two well-established analytical separation techniques that are continuously being adapted for performing distinctive separations and analyses of multitudes of complex and/or unique samples. Since their introduction, these techniques have been pivotal in the discovery, analysis, and understanding of a variety of samples and still prove to be key analytical tools for biological investigation. Using these techniques, one can obtain a wide-range of valuable sample information from the hydrophobicity and molecular weights to size and charge distributions. Furthermore, these techniques allow for sample analysis, purification, and collection for additional sample analysis, such as mass spectrometry analysis. My doctoral dissertation encompasses the full scope of these two techniques and novel approaches for the investigation of distinct, relevant samples. Described herein is the fabrication of glass microfluidic devices used for CE and their diversity for numerous investigations. Chapter 2 shows that the resolution of the photomasks used in microchip fabrication does not alter the separation efficiency of the devices, as the separations remain diffusion-limited. Using an in-house built capillary electrophoresis system, wheat proteins were separated more than 25% faster than previously reported in literature, and the electropherograms used for sample varietal identification. The fabrication of a robust, portable CE system capable of performing biological analysis in microgravity and hypergravity environments is also discussed. The need for and features necessary to achieve a reliable, robust, automated system is further described in Chapter 4. Isolation and analysis of the pea aphid (Acyrthosiphon pisum) salivary secretions was completed for the first time using HPLC. By altering the aphid environment and the sample treatment parameters, sample concentrations were increased above the limit of detection. Coupled with mass spectrometry, identification of pea aphid salivary proteins such as exopeptidase, angiotensin converting enzyme, and Buchnera proteins has been achieved. Finally, a simplified contact conductivity detection system for the detection of jurkat cells was developed that surpasses current, complex optical systems. The experiments described in this dissertation demonstrate novel approaches for the preparation, separation, analysis, and identification of a wide variety of common, and uncommon, samples.
118

Implication des PPARgamma dans l'effet cardioprotecteur des endocannabinoïdes et du préconditionnement ischémique

Awad, Dima January 2005 (has links)
Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.
119

Teores de taninos e produção de gases in vitro da silagem de sorgo com adição de níveis crescentes de guandu / Tannins Levels and gas production in vitro of sorghum silage with the addition of increasing levels of pigeon pea

Pinedo, Lerner Arévalo 30 November 2009 (has links)
Na alimentação animal, o sorgo pode ser explorado de diversas formas. Além dos grãos, a planta pode ser oferecida na forma de silagem, rolão, verde ou ainda pastejada; embora o valor nutritivo pode sofrer algumas variações pela presença ou ausência de compostos fenólicos como os taninos condensados. O objetivo deste trabalho foi avaliar a composição química-bromatológica, qualidade fermentativa e produção de gases in vitro nas silagens de sorgo granífero adicionados com diferentes níveis de guandu. O estudo foi dividido em dois experimentos. O primeiro estudo (Capítulo 3) avaliou os efeitos da adição de forragem de guandu sobre a composição química-bromatológica e fermentativas da silagem de sorgo granífero. Os tratamentos foram compostos por: T1 - Silagem com 100% de sorgo, T2 - Silagem com 25% de guandu e 75% de sorgo, T3 - Silagem com 50% de guandu e 50% de sorgo, T4 - Silagem com 75% de guandu e 25% de sorgo e T5 Silagem com 100% de guandu. As variáveis estudadas para a composição química e fermentativas das silagens foram: matéria seca (MS), proteína bruta (PB), fibra em detergente neutro (FDN), fibra em detergente neutro (FDA), carboidratos totais (CHOT), matéria mineral (MM), fenóis totais (FT), taninos totais (TT), taninos condensados (TC), pH, capacidade tampão (CT), perdas fermentativas e ácido lático. A adição de guandu promoveu efeito linear (P<0,01) nas silagens para os teores de MS, PB, FDN, FDA, FT, assim como para as perdas fermentativas de MS da silagem. Enquanto para os teores de CHOT, MM e TC verificaram-se respostas quadráticas (p<0,01) entre as silagens. Inclusões de 25, 50 e 75% de guandu, com base na matéria fresca, seriam suficientes para melhorar o valor nutricional assim como para se obter melhor padrão fermentativo da silagem de sorgo. O segundo estudo (Capítulo 4) avaliou a produção total de gases, metano, degradabilidade da MS (DMS) e degradabilidade da MO (DMO) em silagens de sorgo granífero com níveis crescentes de guandu através da técnica in vitro de produção de gases. Foram avaliadas as cinco silagens de sorgo granífero com níveis crescentes (0, 25, 50, 75 e 100%) de guandu utilizados como substratos. Para avaliar o efeito do tanino nas silagens sobre a produção de gases, procedeu-se um bioensaio, no qual os substratos foram incubados na presença de polietileno glicol (PEG), macro molécula capaz de ligar-se aos taninos presente no substrato, liberando os nutrientes para a fermentação; sendo o efeito do tanino medido pelo incremento na produção de gases. Não houve diferença estatística para a produção total de gases e metano para os níveis de inclusão do guandu, entretanto houve diferença significativa para o contraste nível zero e a inclusão do guandu. Para os incrementos também não houve diferença significativa para as variáveis (PG, CH4, DMS e DMO). Por outro lado, houve maior PG e maior incremento para o nível de 25% de guandu com a presença do PEG. Foi encontrado maior emissão de metano e incremento de metano para o nível 50% de guandu, quando comparado com os demais níveis. Houve maior DMS e DMO no substrato com 100% de guandu com a presença do PEG. Concluiu-se que a adição de forragem de guandu na silagem de sorgo aumentou o conteúdo de PB e reduziu os teores de FDN, implicando um melhor valor nutritivo das silagens, contudo os taninos condensados precisariam ser monitorados para futuros experimentos in vivo / In animal nutrition, sorghum can be used in various ways. Besides grain, the plant can be offered as silage, pollard, green or even grazed. Although the nutritional value may undergo some changes by the presence or absence of phenolic compounds such as condensed tannins. The objective of this study was to evaluate the chemical composition, fermentation quality and gas production in vitro in sorghum silage added with different levels of pigeon pea. The study was divided into two experiments. The first study (Chapter 3) evaluated the effects of the addition of pigeon pea grass on the chemical composition and fermentation of sorghum silage. The treatments were: T1 - silage with 100% sorghum, T2 - silage with 25% of pigeon pea and sorghum 75%, T3 - silage with 50% of pigeon pea and sorghum 50%, T4 - silage with 75% pigeon pea and 25% of sorghum and T5 - silage with 100% pigeon pea. The parameters of chemical composition and fermentation of the silage were: dry matter (DM), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), total carbohydrates (TCHO), ash, total phenolics (TP), total tannins (TT), condensed tannins (CT), pH, buffer capacity (BC), losses of fermentation and lactic acid. The addition of pigeon pea showed linear effect (P <0.01) in silage for DM, CP, NDF, ADF, TP, as well as the levels of CT and fermentation losses in DM of silage. As for the contents of TCHO, CT and MM there were quadratic responses (p <0.01) among silages. The results observed that, inclusion of 25, 50 and 75% pigeon pea, based on fresh weight, are sufficient to improve the nutritional value and to achieve better fermentation pattern of sorghum silage. The second study (Chapter 4) evaluated the production of gases, methane, DM degradability and degradability of OM in silage sorghum with increasing levels of pigeon pea using the technique of bioassay gas production. Five types of grain sorghum silage with increasing levels (0, 25, 50, 75 and 100%) of pigeon pea were used as substrates and evaluated by gás production technique. There were no significant differences with and without the presence of PEG within each level using regression, for (GP, CH4 and DMD), but there were significant effect for using of contrast for the variables (GP, CH4 and OMD). No significant difference was observed for the increments for the variables (GP and CH4,). On the other hand GP was more increase in the level of 25% of pigeon pea in the presence of PEG. Compared with the other levels of pigeon pea the level 50% showed higher emissions of methane. In the presence of PEG,DMD and OMD Showed higher percentage on the substrate with 100% of pigeon pea . it can be concluded that ,the addition of pigeon pea in sorghum silage increased the PC content and decreased the NDF, implying a higher nutritive value of silages, but the tannins need to be monitored for future experiments in vivo
120

Amido resistente obtido a partir de amido de leguminosas e de seus hidrolisados / Resistant starch from legumes starches and their hydrolysates

Polesi, Luis Fernando 28 August 2009 (has links)
O amido resistente (AR) é a fração do amido que não sofre a ação das enzimas digestivas, apresentando comportamento semelhante ao da fibra dietética. O objetivo do presente trabalho foi avaliar o teor e as características dos AR obtidos a partir dos amidos de ervilha e de grão-de-bico por diferentes processos de redução de massa molecular. Os amidos naturais ou gelatinizados foram submetidos a processos de hidrólise ácida (HCl 2 M por 2,5 h) ou enzimática (pululanase, 40 U/g por 10 h) previamente a um processo controle, que constou de tratamento hidrotérmico (autoclavagem a 121 °C por 30 min), refrigeração (4 °C por 24 h) e liofilização. O material produzido foi caracterizado quanto ao aspecto geral por microscopia eletrônica de varredura (MEV), teor de AR, teor de fibra dietética total (FDT), índice de absorção de água (IAA), índice de solubilidade em água (ISA), padrão de cristalinidade (difração de raios X), viscosidade (RVA - Rapid Visco Analyser) e propriedades térmicas (DSC - Differential Scanning Calorimeter). O teor de AR para o amido natural de ervilha e grãode- bico foi de 39,8 e 31,9 %, respectivamente. Nos amidos processados esse teor variou de 38,5 a 54,6 % para a ervilha e de 16,4 a 32,3 % para o grão-de-bico. Os melhores tratamentos para elevar o teor de AR foram o tratamento ácido (amido natural e gelatinizado) para o amido de ervilha e o tratamento enzimático (amido gelatinizado) para o amido de grão-de-bico. Os teores de FDT dos amidos processados de ervilha variaram de 22,9 a 37,1 % e foram superiores aos do grão-de-bico, que variaram entre 7,2 e 15,7 %. A MEV revelou a presença de grânulos inteiros ou não fragmentados nos amidos de ervilha dos diferentes tratamentos, enquanto os amidos de grão-de-bico tratados apresentaram apenas massa amorfa, sem a evidência de grânulos. Os padrões de cristalinidade dos amidos naturais foram tipo B e C, respectivamente para os amidos de ervilha e grão-de-bico, entretanto, os amidos processados de ambos apresentaram padrão do tipo B. Os amidos naturais apresentaram endotermas entre 56 e 90 °C, enquanto os amidos processados apresentaram endotermas em temperaturas superiores, entre 131 e 171 °C. A entalpia de gelat inização (H) dos amidos de ervilha processados foi superior à dos amidos de grão-de-bico. Os amidos natural e processados de ervilha, de modo geral, apresentaram viscosidade baixa (< 20 RVU) em RVA. O amido de grão-de-bico natural apresentou viscoamilograma bem definido, característico da fonte. Os amidos resistentes obtidos por hidrólise, de ambas as fontes, apresentaram redução na viscosidade em comparação com o controle. A viscosidade foi inversamente proporcional ao teor de AR nas amostras. A hidrólise e o processamento térmico promoveram o aumento no IAA e ISA dos amidos tratados. Os processos de hidrólises dos amidos de ervilha e de grão-de-bico podem elevar o teor de AR se comparados com o método controle. / Resistant starch (RS) is the fraction of starch that does not suffer the action of digestive enzymes, showing similar behavior to that of dietary fiber. The aim of this study was to evaluate the amounts and characteristics of RS obtained from chick-pea and high amylose pea starches using different processes of molecular weight reduction. The natural or pregelatinized starches were submitted to acid (2 M HCl for 2.5 h) or enzymatic (pullulanase, 40 U / g per 10 h) hydrolysis prior to a control process, which consisted of hydrothermal treatment (autoclaving at 121 ° C for 30 min), refrigeration (4 ° C for 24 h) and liophilization. The material was characterized as to the general appearance by scanning electron microscopy (SEM), RS content, total dietary fiber (TDF) content, water absorption index (WAI), water solubility index (WSI), crystallinity pattern (X-ray diffraction), viscosity (RVA - Rapid Visco Analyzer) and thermal properties (DSC - Differential Scanning Calorimeter). The RS content in pea and chick-pea natural starch was 39.8 and 31.9%, respectively. The processed starches showed contents ranging from 38.5 to 54.6% for pea and from 16.4 to 32.3% for chick-pea starch. The best treatments to raise the level of RS were the acid treatment (natural and gelatinized starch) for pea and the enzymic treatment (gelatinized starch) for chick-pea starch. The FDT amounts in processed pea starches ranged from 22.9 to 37.1% and were higher than those of chick-pea, which ranged between 7.2 and 15.7%. The photomicrographs in SEM revealed the presence of whole grains (not fragmented) in pea starches treatments, while the treated chick-pea starches showed only amorphous mass, without the evidence of granules. The cristallinity patterns of natural starches were B and C types, respectively for pea and chick-pea starch. Both processed starches, however, presented B type pattern. The natural starches showed endotherms between 56 and 90°C, while the processed starches showed endotherms at higher temperatures (131 and 171°C). The processed pea starches gelatinizati on enthalpy (H) was higher than those of processed chick-pea starches. The natural and processed pea starches, in general, showed low viscosity (<20 RVU) in RVA. The natural chick-pea starch presented viscoamylogram well defined, typical of this botanical source. The resistant starches obtained by hydrolysis showed in both sources, a decrease in viscosity compared to the control treatment. The viscosity was inversely proportional to the RS content in the samples. The hydrolysis and the thermal processing promoted an increase in WAI and WSI of treated starches. The hydrolysis process of pea and chickpea starches may raise the level of RS when compared to the control process.

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