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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.
11

Efeitos do óleo de nim (Azadirachta indica A. Juss) sobre a reprodução e perfil metabólico de machos ovinos / Effects of Neem oil (Azadirachta indica A. Juss) on reproductive and metabolic profile of male sheep

Brito, Osvaldo Santos de 27 February 2013 (has links)
Submitted by Reginaldo Soares de Freitas (reginaldo.freitas@ufv.br) on 2016-06-27T10:15:45Z No. of bitstreams: 1 texto completo.pdf: 655848 bytes, checksum: 0ff4198bce278adfb35d72306b750cef (MD5) / Made available in DSpace on 2016-06-27T10:15:45Z (GMT). No. of bitstreams: 1 texto completo.pdf: 655848 bytes, checksum: 0ff4198bce278adfb35d72306b750cef (MD5) Previous issue date: 2013-02-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O objetivo deste estudo foi avaliar o efeito da administração via oral do óleo de nim sobre a função reprodutiva e o perfil metabólico de carneiros mestiços da raça Santa Inês. Trinta animais foram distribuídos em quatro grupos (G): GI - controle, administração de 20 mL de água por animal por via oral; e GII, GIII e GIV – administração de 1, 2 e 3 mL de óleo de nim/kg de peso vivo (PV) por via oral, respectivamente, durante sete dias. Realizou-se a biometria testicular e coletou-se sêmen duas vezes por semana durante 93 dias para avaliação dos aspectos físicos e morfológicos. Amostras de sangue foram coletadas nos dias D1, D4, D8, D30, D60 e D90, para determinação da concentração plasmática de testosterona e do perfil metabólico plasmático dos animais. Ao final do período experimental, os animais foram abatidos; os testículos, coletados e pesados; e foram obtidas amostras para avaliações histológicas. Houve comportamento linear decrescente (P˂0,05) para ganho de peso. Observou-se comportamento linear decrescente (P˂0,05) para volume seminal, turbilhão e vigor espermático, motilidade progressiva e concentração espermática. Para defeitos maiores verificou-se comportamento linear crescente (P<0,05), e defeitos menores, comportamento linear decrescente (P<0,05). Não houve diferença (P>0,05) para defeitos totais. Perímetro escrotal e consistência testicular apresentaram comportamento linear decrescente (P<0,05). Quanto aos dados da morfometria testicular, observou-se diferença (P<0,05) para volume das células de Leydig, volume do conjuntivo e volume do espaço intertubular, porém não houve diferença (P>0,05) para peso do testículo, índice gonadossomático, porção volumétrica da lâmina basal, lúmen, epitélio germinativo, vasos sanguíneos e linfáticos, tecido conjuntivo, túbulo seminífero, espaço intertubular, volume dos vasos sanguíneos e linfáticos, volume do túbulo seminífero, comprimento total dos túbulos seminíferos, comprimento total dos túbulos seminíferos por grama de testículo, índice leydigossomático e índice tubolossomático. No perfil metabólico, observou-se comportamento quadrático decrescente (P<0,05) para LDL e quadrático crescente (P<0,05) para concentração plasmática de VLDL e triglicerídios. Não houve diferença (P>0,05) para concentração plasmática de colesterol total, HDL, ureia e testosterona. A administração oral de óleo de nim nas concentrações de até 3 mL/kg de peso vivo durante sete dias causou prejuízos à função reprodutiva de carneiros mestiços da raça Santa Inês, mostrou-se dose – dependente e provocou intoxicação dos animais na maior concentração. / The aim of the study was to evaluate the effect of oral administration of Neem oil on the reproductive function and metabolic profile of crossbred Santa Inês sheep. Thirty animals were divided into four groups (G): GI - control, oral administration of 20 mL of water per animal; GII, GIII and GIV – oral administration of 1, 2 and 3 mL of neem oil/kg body weight (BW), respectively, for seven days. Testis size was estimated and semen was collected twice a week for 93 days to evaluate physical and morphological aspects. Blood samples were collected on days D1, D4, D8, D30, D60 and D90 for determination of plasma testosterone and plasma metabolic profile of the animals. At the end of the experimental period, the animals were slaughtered, and the testes were collected, weighed and sampled for histological evaluations. There was a linear decrease (P˂0.05) for weight gain. A linear decrease (P˂0.05) was observed for semen volume, sperm vigor, turmoil, progressive motility, and sperm concentration. A linear increase (P<0.05) was observed for major defects, and a linear decrease (P<0.05), for minor defects. There was no difference (P>0.05) for total defects. Scrotal circumference and testicular consistency decreased linearly (P<0.05). For the morphometric data of the testes, a difference was observed (P<0.05) for Leydig cell volume, volume of tissue and volume of intertubular space. However, there was no difference (P>0.05) for testis weight, gonadosomatic index, volumetric basal lamina, lumen, germinal epithelium, connective tissue, seminiferous tubule, intertubular space, volume of blood and lymph vessels, seminiferous tubule volume, total length of the seminiferous tubules, total length of seminiferous tubules per testicular gram, leydigosomatic index and tubulosomatic index. In the metabolic profile, a quadratic decrease (P<0.05) was observed for LDL and a quadratic increase (P<0.05), for plasma VLDL and triglycerides. There was no difference (P>0.05) for plasma concentration of total cholesterol, HDL cholesterol, urea and testosterone. Oral administration of Neem oil at concentrations of up to 3 mL/kg body weight for 7 days produced damage to the reproductive function of crossbred Santa Inês sheep. It was shown to be dose dependent and poisoned the animals at the highest concentration.
12

Combinatorial Games on Graphs

Williams, Trevor K. 01 May 2017 (has links)
Combinatorial games are intriguing and have a tendency to engross students and lead them into a serious study of mathematics. The engaging nature of games is the basis for this thesis. Two combinatorial games along with some educational tools were developed in the pursuit of the solution of these games. The game of Nim is at least centuries old, possibly originating in China, but noted in the 16th century in European countries. It consists of several stacks of tokens, and two players alternate taking one or more tokens from one of the stacks, and the player who cannot make a move loses. The formal and intense study of Nim culminated in the celebrated Sprague-Grundy Theorem, which is now one of the centerpieces in the theory of impartial combinatorial games. We study a variation on Nim, played on a graph. Graph Nim, for which the theory of Sprague-Grundy does not provide a clear strategy, was originally developed at the University of Colorado Denver. Graph Nim was first played on graphs of three vertices. The winning strategy, and losing position, of three vertex Graph Nim has been discovered, but we will expand the game to four vertices and develop the winning strategies for four vertex Graph Nim. Graph Theory is a markedly visual field of mathematics. It is extremely useful for graph theorists and students to visualize the graphs they are studying. There exists software to visualize and analyze graphs, such as SAGE, but it is often extremely difficult to learn how use such programs. The tools in GeoGebra make pretty graphs, but there is no automated way to make a graph or analyze a graph that has been built. Fortunately GeoGebra allows the use of JavaScript in the creation of buttons which allow us to build useful Graph Theory tools in GeoGebra. We will discuss two applets we have created that can be used to help students learn some of the basics of Graph Theory. The game of thrones is a two-player impartial combinatorial game played on an oriented complete graph (or tournament) named after the popular fantasy book and TV series. The game of thrones relies on a special type of vertex called a king. A king is a vertex, k, in a tournament, T, which for all x in T either k beats x or there exists a vertex y such that k beats y and y beats x. Players take turns removing vertices from a given tournament until there is only one king left in the resulting tournament. The winning player is the one which makes the final move. We develop a winning position and classify those tournaments that are optimal for the first or second-moving player.
13

Etude didactique des situations de recherche pour la classe concernant des jeux combinatoires de type Nim / Didactical study of research situations for the classroom concerning combinatorial games

Colipan, Ximena 16 January 2014 (has links)
La recherche que nous avons menée s'inscrit dans les projets de l'équipe de recherche Maths à Modeler. En particulier dans celui portant sur les situations de recherche pour la classe (SiRC). Cette recherche est centrée sur l'étude du rôle, pour l'apprentissage des savoir-faire fondamentaux, de l'activité mathématique, des jeux combinatoires et plus particulièrement des jeux de type Nim. Nous mettons sous l'expression « savoir-faire fondamentaux » les savoirs, méthodes et techniques qui sont à la base de toute activité mathématique : l'expérimentation, l'étude de cas particuliers, l'énoncé et l'étude de conjectures, la construction d'exemples et contre-exemples, la modélisation, l'élaboration et l'écriture de preuves, la définition d'objets, etc. (Grenier et Payan, 2002). Le sujet est la construction, l'expérimentation et l'analyse de SiRC basées sur des jeux combinatoires de type Nim pour des élèves, afin de leur faire construire et développer les savoir- faire indispensables à la mise en œuvre d'une « démarche mathématique ». Notre problématique porte donc sur l'identification des savoirs notionnels et des savoir-faire fondamentaux de l'activité mathématique qui sont mis en œuvre dans les jeux combinatoires de type Nim et la détermination des conditions et contraintes épistémologiques et didactiques favorisant l'apprentissage en classe de ces savoirs. Pour mener à bien notre étude, nous nous sommes appuyés d'une part sur certains éléments de la théorie des situations didactiques de Brousseau (Brousseau, 2004) et de la théorie des champs conceptuels de Vergnaud (Vergnaud, 1994) et, d'autre part, sur le modèle SiRC, contribuant à préciser ce modèle. Nous nous sommes servis de l'étude épistémologique et didactique des jeux de type Nim, pour mener les analyses mathématique et didactique de deux SiRC : la première, nommée « jeu d'Euclide géométrique », situation de jeu de type Nim, construite spécifiquement pour cette recherche, basée sur un jeu d'Euclide classique. La seconde, nommée le « jeu du chocolat », situation expérimentée régulièrement dans l'équipe Maths à Modeler, mais dont l'étude didactique n'avait pas vraiment été faite. Les analyses et expérimentations que nous avons menées montrent que les situations basées sur des jeux de type Nim, peuvent induire une activité mathématique qui va au-delà du développement et de la pratique de techniques mathématiques : Elles peuvent ouvrir l'accès à des savoir-faire plus généraux propres de l'activité mathématique. / This research is included in the project of the research group "Maths à modeler". In particular, in the part that corresponds to the study of "situations de recherche pour la classe" (SiRC). This research is focused in the study of the role played by the mathematical activity, the combinatorial games and particularly the games of Nim-type in learning the fundamental know-hows. We put under the term "fundamental know-hows" all the knowledge, methods and techniques found in all mathematical activity: experimenting, studying particular cases, conjecturing, building examples and counter-examples, modeling, proving, defining, etc. (Grenier et Payan, 2002). The main aim of this research is the construction, the experimentation and the analysis of SiRC based on combinatorial games of Nim-type for students designed to make them build and develop the know-hows required for the implementation of a "mathematical process". Our main problem is then identifying the fundamental and notional know-hows of the mathematical activity that are used in combinatorial games of Nim-type and establishing the epistemological and didactical conditions and constrains that favor the learning of these know-hows in the classroom. To achieve our aim, our research is supported, on one hand, by some aspects of the theory of didactical situation by Brousseau (Brousseau, 2004) and the theory of conceptual fields by Vergnaud (Vergnaud, 1994) and, on the other hand, by the SiRC model, where we also contribute to precise it. We based our research in the epistemological and didactical study of Nim-type games to conduct mathematical and didactical analysis of two SiRC: the first one, called "the geometrical Euclid game", is a situation of Nim-type created specifically for this research and based on the classical Euclid game. The second one, called "the chocolate game", is a situation frequently experimented by the research group math à modeler whose didactical analysis had not been done yet. The analysis and experimentations we have conducted show that the situations based on Nim-type games can lead to a mathematical activity that goes beyond developing and practicing mathematical techniques. They can open access to more general know-hows specific to the mathematical activity.
14

Avaliação Ecotoxicológica de Agrotóxicos, seus Componentes e Afins: Teste para o Parâmetro Abelhas / Ecotoxicological Evaluation of Pesticides and their Components: Honeybees Protocols

Fernandes, Renata Oliveira de 31 July 2012 (has links)
Made available in DSpace on 2015-03-26T13:30:43Z (GMT). No. of bitstreams: 1 texto completo .pdf: 755196 bytes, checksum: 7cbe9fcb487f4294780e4e4ebdd9f492 (MD5) Previous issue date: 2012-07-31 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / In order to register a Pesticide, Brazilian Law is based on the evaluation and classification of the Pesticides Potential Hazard of the products. Also planned is the introduction of the Environmental and Human Health Risk Assessment for pesticides both based on study results that follow internationally recognized protocols, however, all these those study protocols, including bee toxicity, may not be adequate to represent the Brazilian reality, once they are applied mostly in temperate countries. In this sense, there is growing concern about bees and other pollinators that possess universal importance to the economy, agriculture and environmental balance on the planet. The disappearance of these insects of the hives, a phenomenon commonly known as CCD (Colony Collapse Disorder) has been discussed nowadays in Brazil and worldwide. This study aimed to identify and study the existing protocols for assessing the toxicity of pesticides to bees, as well as to discuss alternative studies to better adapt the protocols used abroad to the Brazilian scenario. In order to do that, studies were conducted on survival, walking behavior, proboscis extention response (P.E.R), nutrition and morphology of hypopharyngeal glands in africanized Apis mellifera exposed to the insecticide Azamax®. Results have demonstrated that bee survivial can be diminished when those insects are exposed to the insecticide at field doses and also that bees present morphological changes in the areas of acini hypopharyngeal glands, preventing its development when young worker bees were exposed to three different doses of insecticide. These findings indicated the importance of exploring pesticides sub lethal effects on insects, observing parameters such as walking behavior, PER (Proboscis Extension Response), nutrition and morphology of hypopharingeal glands, instead of only consider acute toxicity studies, like it happens nowadays, when reviewing the test protocols that already exists, considering not only hazard evaluation, but also the dose and exposition scenery. / A legislação brasileira para o Registro de Produtos Agrotóxicos, seus Componentes e Afins, tem como base a avaliação e classificação do Potencial de Periculosidade desses produtos, com previsão da Avaliação do Risco Ambiental e Toxicológico, fundamentados em protocolos internacionais para diversos parâmetros, inclusive estudos em abelhas, que podem não refletir a realidade brasileira. Um fator de preocupação no Brasil e no mundo é o Colapso das Colonias (CCD), fenômeno de desaparecimento das abelhas, onde uma das hipóteses discutidas para tal fato seria o uso indiscriminado de agrotóxicos. Este trabalho teve como objetivo levantar e estudar os protocolos existentes para a avaliação da toxicidade dos agrotóxicos em abelhas, bem como a discutir estudos alternativos para melhor adequá-los ao cenário brasileiro. Neste sentido, foram conduzidos estudos de sobrevivência, comportamento de caminhamento, extensão de probóscide e de nutrição sobre as glândulas hipofaringeanas em Apis mellifera africanizadas expostas ao inseticida Azamax®. Os resultados demonstraram que a sobrevivência das abelhas pode ser reduzida quando expostas ao inseticida na dose de campo e que as abelhas apresentaram alterações morfológicas nas áreas dos ácinos das glândulas hipofaringeanas em operárias jovens expostas a três doses diferentes do inseticida. Esses achados indicaram a importância de testar os efeitos subletais dos agrotóxicos em insetos, observando parâmetros como comportamento de caminhamento, PER (Proboscis Extension Response), nutrição sobre glândulas hipofaringeanas, ao invés de considerar apenas estudos de toxicidade aguda como acontece nos dias de hoje para a revisão dos protocolos de testes vigentes, considerando não apenas a avaliação do perigo, mas também da dose e o cenário de exposição.
15

Modélisation hydrologique intégrée de bassins versants fortement transitoires : développement d'outils numériques et applications / Integrated hydrological modeling of highly transient watersheds : development of numerical tools and applications

Jeannot, Benjamin 15 October 2018 (has links)
L’objectif du travail de thèse est d'œuvrer au développement et à l’application d’un modèle hydrologique intégré pré-existant (Pan et al., 2015; Weill et al., 2017) : Normally Integrated Model (NIM). La spécificité de ce modèle est d’intégrer l’équation d’écoulement souterrain 3D sur la direction perpendiculaire au substratum, de façon à se ramener à un problème en deux dimensions. Il en résulte un gain substantiel en termes de temps de simulation, et une économie du point de vue de l’espace mémoire requis. Dans le cadre de cette thèse, NIM a été entièrement recodé et optimisé. Un module de ruissellement 2-D a également été implémenté, ce qui a permis d’appliquer le modèle en situations réelles sur deux bassins versants distincts. En sus, la validité des simulations issues de NIM et l'efficacité du modèle en termes de temps de calcul ont été évaluées sur de nombreux cas tests synthétiques. / This works aims at contributing to the development and application of a pre-existing integrated hydrological model (Pan et al., 2015; Weill et al., 2017) : Normally Integrated Model (NIM). The specificity of this model is to perform an integration of the 3D groundwater flow equation over the direction perpendicular to the substratum of the aquifer, so that the problem becomes 2D. It results in a substantial gain both in calculation time and required memory. During this thesis, NIM has been fully rewritten and optimized. Besides, a 2D overland flow module has been implemented, which enabled to apply the model in real cases on two distinct watersheds. Furthermore, the validity of NIM simulations and their efficiency as regards computation times have been assessed on numerous synthetic test cases.
16

Teorie her pro nadané žáky středních škol / Game Theory for Gifted Secondary School Students

Skálová, Alena January 2014 (has links)
The thesis contains a textbook for gifted secondary school students. Its aim is to give to these students (or to their teachers) a Czech-written text covering fundamental principles in the field of game theory. In the first part we introduce the combinatorial games and some elementary methods of their solution. The second part is devoted to the game of Nim, to the Sprague-Grundy function and to the sums of the combinatorial games. It also contains a necessary introduction to the binary numeral system. In the third part we present the concept of matrix and bimatrix games. There is a lot of exercises and examples in the textbook. At the end we bring solutions to the most of them, providing the active reader with the opportunity of checking their own solutions.
17

O jogo do NIM: uma alternativa para reforçar o algoritmo da divisão no sexto ano do ensino fundamental

Cassiano, Milton 15 May 2009 (has links)
Made available in DSpace on 2016-04-27T16:58:54Z (GMT). No. of bitstreams: 1 Milton Cassiano.pdf: 2491618 bytes, checksum: 95c55c98dce7f49e53273451d23ec0ec (MD5) Previous issue date: 2009-05-15 / Secretaria da Educação do Estado de São Paulo / Games have always been a part of the daily life from children since the first years of age. Thus, when they play, they question, ask questions, focus, abstract, use their imagination and spend hours playing. This way, the purpose of this study was to verify how the NIM game can help the construction or improvement of the division algorithm. A qualitative research was done with the application of a prior test and some students were selected to participate in the workshops that involved the NIM game. This study was based on Brouseau s Theory of Didactic Situations (1996) and the methodological choice was based on the theory of Didactic Engineering from Artigue (1996) that contributed to the achievement of our goals. Facing the results presented in the prior test and even in the after test, the difficulties presented by the students were clear, regarding the division algorithm and that can be of great value for future studies about the theme / O jogo sempre fez parte do dia a dia das crianças desde os primeiros anos de idade. Assim, quando jogam elas questionam, fazem perguntas, concentram-se, abstraem, usam a imaginação e ficam horas a fio brincando. Desse modo, este estudo teve como objetivo verificar como o jogo do NIM pode auxiliar na construção ou aprimoramento do Algoritmo da Divisão. Foi realizada uma pesquisa qualitativa, com aplicação de um pré-teste para que alguns alunos fossem selecionados para participarem das oficinas que envolviam o jogo do NIM. O presente estudo baseou-se na Teoria das Situações Didáticas de Brousseau (1996) e a escolha metodológica apoiou-se nos pressupostos da Engenharia Didática de Artigue (1996) que contribuíram para o alcance de nossos objetivos. Diante dos resultados apresentados no pré-teste e mesmo no pós-teste, as dificuldades apresentadas pelos estudantes, perante o Algoritmo da Divisão, ficaram claras, o que pode ser de grande valia para estudos futuros a respeito do tema
18

Lagererfahrung und Identität literarische Spiegelungen sowjetischer Lagerhaft in Texten von Varlam Šalamov, Lev Konson, Naum Nim und Andrej Sinjavskij

Thaidigsmann, Karoline January 2009 (has links)
Zugl.: Heidelberg, Univ., Diss., 2009
19

Efeitos do óleo da semente de neem (Azadirachta indica A. Juss) nos ovócitos e glândulas salivares de carrapatos Rhipicephalus sanguineus (Latreille, 1806) (Acari: Ixodidae)

Remedio, Rafael Neodini [UNESP] 13 November 2014 (has links) (PDF)
Made available in DSpace on 2016-01-13T13:28:11Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-11-13. Added 1 bitstream(s) on 2016-01-13T13:33:45Z : No. of bitstreams: 1 000856112.pdf: 4422258 bytes, checksum: 675eb8d60dbbf40c256acc5ba1788f42 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Os carrapatos Rhipicephalus sanguineus têm atraído, nos últimos anos, a atenção de pesquisadores, bem como de órgãos gerenciadores da saúde pública, por estarem se tornando grandes pragas urbanas, transmissoras de doenças para cães e humanos. Por esta razão, a busca por formulações com ação acaricida tem sido preocupação constante das indústrias farmacêuticas veterinárias. No entanto, a grande maioria dos produtos atualmente comercializados apresenta alta toxicidade aos hospedeiros dos ectoparasitas e ao meio ambiente, induzindo, inclusive, resistência nos carrapatos. Métodos alternativos de controle, como o uso de extratos de plantas, por exemplo, têm se tornado cada vez mais interessantes, já que apresentam menores custos e baixa toxicidade. Neste sentido, destaca-se a espécie Azadirachta indica (neem), cujos extratos de folhas e sementes apresentam reconhecido potencial repelente, inseticida e acaricida. Desta forma, este estudo teve como objetivo avaliar as alterações morfológicas observadas no ovário e nas glândulas salivares de fêmeas semiingurgitadas de carrapatos R. sanguineus, submetidas à aplicação tópica do óleo extraído das sementes de neem, nas concentrações de 20, 40 e 60%, utilizando-se etanol aquoso a 10% como solvente. Os órgãos foram coletados, fixados, e analisados por meio de técnicas de microscopia de luz convencional, microscopia confocal de varredura a laser e microscopia eletrônica de transmissão. De forma geral, a metodologia proposta neste trabalho permitiu a simulação de um tratamento tópico dos animais infestados, tornando os resultados obtidos mais próximos de uma aplicação prática em campo. Em ambos os órgãos analisados, o óleo de neem demonstrou efeitos claramente dose-dependentes. Os ovócitos e os ácinos glandulares de carrapatos R. sanguineus exibiram alterações morfológicas semelhantes, tais como sinais evidentes de desorganização citoplasmática,... / Rhipicephalus sanguineus ticks have attracted, in recent years, the attention of researchers as well as public health managers, since they have become major urban pests, transmitters of diseases to humans and dogs. For this reason, the search for formulations with acaricide action has been constant concern of veterinary pharmaceutical industries. However, the vast majority of products currently commercialized exhibits high toxicity to the hosts of these ectoparasites and to the environment, even inducing resistance in ticks. Alternative control methods such as the use of plant extracts, for example, have become increasingly interesting, since they have reduced costs and low toxicity. In this sense, Azadirachta indica (neem) species stands out, as its leaf and seed extracts have recognized repellent, insecticide and acaricide potential. Thus, this study aimed to evaluate the morphological alterations resulting from the action of neem in the ovary and salivary glands of semi-engorged R. sanguineus female ticks, subjected to the topical application of the oil extracted from neem seeds, at concentrations of 20, 40 and 60%, using 10% aqueous ethanol as solvent. The organs were collected and fixed, and analyzed by means of techniques in conventional light microscopy, confocal laser scanning microscopy and transmission electron microscopy. In general, the methodology proposed in this work allowed the simulation of a topical treatment of the infested animals, making the results closer to a practical application in field. In both analyzed organs, neem oil clearly demonstrated a dose-dependent effect. Oocytes and glandular acini of R. sanguineus ticks exhibited similar morphological changes, such as evident signs of cytoplasmic disorganization, cellular vacuolation, nuclear or nucleolar irregularities, dilation of mitochondrial cristae, as well as dilation in rough endoplasmic reticulum lumen. These facts show that, regardless of the organ, neem ...
20

Nano-microencapsulados de extrato de Azadirachta indica usando ligninas do bagaço de cana-de-açúcar: estabilidade e eficácia contra insetos pragas / Nano and micro encapsulation of botanical extracts of Azadirachta indica using sugarcane bagasse lignins

Costa, Eveline Soares 25 July 2014 (has links)
Made available in DSpace on 2016-06-02T20:35:00Z (GMT). No. of bitstreams: 1 6537.pdf: 2866156 bytes, checksum: f6a431ef47337cb8c9a1f74dc2835f9f (MD5) Previous issue date: 2014-07-25 / Universidade Federal de Minas Gerais / The present work aimed the development of a model bioinsecticide for pest insect control using microencapsulated botanical extracts of Azadirachta indica (neem), and natural polymer of lignins, witch were extracted from sugarcane bagasse. Several different extraction methods and chemical modifications were carried out on lignin in order to evaluate yield, cost, environmental advantages and biological efficacy. Among the proposed chemical modifications the main reactions were oxidation and acetylation. Techniques used for biopolymer characterization were FITR, 1H NMR, MALDI-TOF and SEM. Chemometric tools on NMR analyses aided on lignin differentiation according to their groups: oxidized, acetylated and naturals. Lignins were used in microencapsulation processes of extracts and fractions of the natural insecticide, A. indica L. Juss, by using Spray-Drying methods. The obtained products were subjected to thermal and photochemical degradation assays. The formulation promoted stability gains of approximately 40% for the formulated botanical extract. Use of commercial thermal and photochemical protectors were also investigated where it was observed that lignin was more efficient than traditional commercial photostabilizers protectors, showing that there is no need for adding synthetic protectors on microencapsulation process, and consequently, they are not needed on the final product. Microencapsulation was done through process known as Nanoemulsion/Solvent Displacement developed by the workgroup. In this process, botanical material was firstly nanoemulsioned, coated by a biopolymeric film in order to promote nanocapsules, and dried using Spray-Dryer generating micrometric clusters. All formulated material was subjected to biological assays to Spodoptera frugiperda, Diabrotica speciosa, Diatraea saccharalis e Anticarsia gemmatalis. Data obtained on biological testes shows that formulations that were prepared with neem and lignin were as active as non-formulated botanical extract on pest insects. / O presente trabalho teve como objetivo o desenvolvimento de um bioinseticida modelo para controle de insetos-pragas formulado com extrato vegetal de Azadirachta indica (nim), microencapsulado, utilizando como polímero natural ligninas extraídas do bagaço da cana-de-açúcar. Foram realizados diferentes métodos de extração e modificação química da lignina no intuito de comparação de rendimento, custo, vantagens ambientais e eficácia biológica. Entre as modificações químicas propostas as principais foram reações de oxidação e acetilação. As técnicas utilizadas para a caracterização do biopolímero foram o IV-TF, RMN de 1H, MALDI-TOF e MEV. Tecnicas de quimiometria foram empregadas na analise de RMN, auxiliando na diferenciação dos biopolímeros segundo seu grupo: oxidadas, acetiladas e naturais. As ligninas foram utilizadas em processos de microencapsulação de extratos e frações do inseticida natural, Azadirachta indica L. Juss, por Spray-Drying. Os produtos obtidos foram submetidos a ensaios de degradação térmica e fotoquímica. A formulação promoveu ganhos de estabilidade em aproximadamente 40% para o extrato vegetal formulado. O uso de protetores térmicos e UV comerciais também foram investigados onde verificou-se que a lignina foi mais eficiente que protetores fotoestabilizantes tradicionalmente comercializados, mostrando assim, a não necessidade de inserir aditivos sintéticos no processo de microencapsulamento e, consequentemente, no produto final. O microencapsulamento foi realizado utilizando o processo nomeado Nanoemulsão/Deslocamento Solvente desenvolvido no grupo de trabalho. Neste processo, o material vegetal foi nanoemulsionado, revestido por um filme biopolimérico formando as nanocápsulas e secas pela técnica de Spray-Drying gerando um cluster em escala micrométrica. Todo material formulado foi submetido a ensaios biológicos para os insetos Spodoptera frugiperda, Diabrotica speciosa, Diatraea saccharalis e Anticarsia gemmatalis que foram usados como modelos. Os dados obtidos nos ensaios biológicos demostraram que as formulações preparadas com nim e ligninas como envoltórios foram ativas contra os insetos-pragas tanto quanto o extrato vegetal não formulado.

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