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Modelo contingencialista como preditor do grau de adaptação mercadológica de ofertas internacionais / The contingency model as a predictor of the degree of adaptation of international marketing dealsTafner, Rodrigo Esteves 09 April 2014 (has links)
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Previous issue date: 2014-04-09 / This study aims to provide a predictive model of degree of adaptation required for the entry of a particular product in a particular target market, pointing to a position on a continuum of standardization / adaptation based on the contingency view particularly Jain, through the analysis of relationship indicators formed from secondary data and public access. To achieve this goal, a theoretical review pointed constructs not only Internationalization, but Organizational Psychology, and the Cultural Distance Hofstede, the gravitational theory proposed by authors such as Retail Reiley, Converse Huff and that should be integrated in a formative model predicting the degree of adaptation of the International Offering. The resulting theoretical model from the literature review was put to the test with data obtained from secondary databases as the Best Global Brands Ranking, GMID - Euromonitor and Global UN HDI and compared to data obtained using the Delphi method, in which 18 judges internationalization experts judged ex -post adjustment of 48 cases, 7 products in 6 countries over 1 item in only 6 of the 7 countries, by means of Partial Least Squares method - Structural Equation Modeling. The results point to a model with a high degree of prediction, with significance, after removing the bookmark Monetary Value of Brand originally proposed theoretical model. The final model, however can not be generalized because the study investigated some representative group of the population, but offers prospects for expansion of research is the expansion of the sample and the databases used either by the method of regression analysis in Multilevel function of the multi-stage characteristic of the sample. / Este estudo objetiva oferecer um modelo preditivo de grau de adaptação necessária para a entrada de um determinado produto em um determinado mercado-alvo, apontando uma posição em um contínuo de padronização/ adaptação baseado na visão contingencialista, principalmente de Jain, por meio da análise da relação de indicadores formados a partir de dados secundários e de acesso público. Para atingir esse objetivo, uma revisão teórica apontou constructos não só de Internacionalização, mas de Psicologia Organizacional, como a Distância Cultural de Hofstede, da Teoria Gravitacional do Varejo proposto por autores como Reiley, Converse e Huff que deveriam se integrar em um modelo formativo de predição do Grau de Adaptação da Oferta Internacional. O modelo teórico resultante da revisão da literatura foi posto à prova com dados obtidos de bases de dados secundários como o Ranking Best Global Brands, GMID Euromonitor e IDH global da ONU e confrontados com dados obtidos por meio do método Delphi, no qual 18 juízes especialistas em internacionalização julgaram ex-post, a adaptação de 48 casos, 7 produtos em 6 países mais 1 produto em somente 6 dos 7 países, por meio do método Partial Least Squares Structural Equation Modeling. Os resultados apontaram para um modelo com alto grau de predição, com significância, após a retirada do indicador Valor Monetário da Marca do modelo teórico originalmente proposto. O modelo final, entretanto não pode ser generalizado pois a pesquisa investigou um grupo pouco representativo da população, mas oferece perspectivas de ampliação da pesquisa seja pela ampliação da amostra e das bases de dados utilizados, seja por meio do método de análise de Regressão Multinível em função da característica multi-estágio da amostra.
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Arquitetura de centros de pesquisas: um estudo de caso múltiplo quantitativo / Architecture of research centres: a quantitative multiple case studyÉrika Di Giaimo Bataglia 06 May 2010 (has links)
O presente trabalho trata-se de um estudo de caso múltiplo de natureza quantitativa. Trata-se de um estudo descritivo em função da comparação e análise dos projetos de arquitetura e explicativo em função da aplicação da modelagem em equação estrutural. Foram visitados e analisados os centros de pesquisas: (A) Instituto Max Planck de Ecologia Química, localizado em Jena, Alemanha; (B) Instituto Max Planck de Antropologia Evolutiva, localizado em Leipzig, Alemanha; (C) Instituto Max Planck de Biologia e Genética de Célula Molecular, localizado em Dresden, Alemanha; (D) Instituto de Biociência, localizado em Liverpool, Inglaterra. Procedeu-se a aplicação de um questionário, para avaliar a percepção dos usuários com relação aos fatores que caracterizam os ambientes de trabalho e que se relacionam com a satisfação pelo ambiente físico. Os fatores extraídos da literatura e analisados foram: interação, privacidade, flexibilidade e percepção de conforto. Analisando as características físicas de cada edifício e os resultados do questionário, constata-se que estas características de fato têm sido percebidas pelos usuários. As evidências empíricas obtidas através do modelo de equação estrutural indicam: (1) que existe uma relação positiva entre condição física para interação e satisfação com o ambiente físico; (2) que existe uma relação positiva entre percepção de conforto e satisfação com o ambiente físico; (3) que existe uma relação positiva entre condição física para interação e condição física para privacidade. / This paper consists of a quantitative multiple case study presenting a descriptive analysis based on comparisons and examinations of architectural project designs, with an explanation of the structural equation modelling application. The following research centres were visited and analysed: (A) Max Planck Chemical Ecology Institute, Jena, Germany; (B) Max Planck Evolutionary Anthropology Institute, Leipzig, Germany; (C) Max Planck Biology and Molecular Cell Genetics Institute, Dresden, Germany; (D) Bioscience Institute, Liverpool, UK. A questionnaire was completed in order to assess user perceptions of factors characterising their work environments, related to satisfaction with their physical surroundings. The factors taken from the literature and analysed were: Interaction, Privacy, Flexibility and Perception of Comfort. Analyses of the physical characteristics of each building and the findings of the questionnaire clearly demonstrate that these characteristics are really perceived by their users. Empirical evidence obtained through the structural equation model indicates that: (1) there is a positive relationship between physical conditions conducive to interaction and satisfaction with physical surroundings; (2) there is a positive relationship between perception of comfort and satisfaction with physical surroundings; (3) there is a positive relationship between physical conditions conducive to interaction and physical conditions providing privacy.
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QSAR e dinâmica molecular no estudo de sistemas biomoleculares: predição da atividade biológica de antagonistas do receptor sigma-1 e simulações de bicamadas lipídicas / QSAR and Molecular Dynamics in the study of biomolecular systems: biological activity prediction of sigma-1 receptor antagonists and simulations of lipid bilayersOliveira, Aline Alves 09 March 2016 (has links)
Diferentes abordagens teóricas têm sido utilizadas em estudos de sistemas biomoleculares com o objetivo de contribuir com o tratamento de diversas doenças. Para a dor neuropática, por exemplo, o estudo de compostos que interagem com o receptor sigma-1 (Sig-1R) pode elucidar os principais fatores associados à atividade biológica dos mesmos. Nesse propósito, estudos de Relações Quantitativas Estrutura-Atividade (QSAR) utilizando os métodos de regressão por Mínimos Quadrados Parciais (PLS) e Rede Neural Artificial (ANN) foram aplicados a 64 antagonistas do Sig-1R pertencentes à classe de 1-arilpirazóis. Modelos PLS e ANN foram utilizados com o objetivo de descrever comportamentos lineares e não lineares, respectivamente, entre um conjunto de descritores e a atividade biológica dos compostos selecionados. O modelo PLS foi obtido com 51 compostos no conjunto treinamento e 13 compostos no conjunto teste (r² = 0,768, q² = 0,684 e r²teste = 0,785). Testes de leave-N-out, randomização da atividade biológica e detecção de outliers confirmaram a robustez e estabilidade dos modelos e mostraram que os mesmos não foram obtidos por correlações ao acaso. Modelos também foram gerados a partir da Rede Neural Artificial Perceptron de Multicamadas (MLP-ANN), sendo que a arquitetura 6-12-1, treinada com as funções de transferência tansig-tansig, apresentou a melhor resposta para a predição da atividade biológica dos compostos (r²treinamento = 0,891, r²validação = 0,852 e r²teste = 0,793). Outra abordagem foi utilizada para simular o ambiente de membranas sinápticas utilizando bicamadas lipídicas compostas por POPC, DOPE, POPS e colesterol. Os estudos de dinâmica molecular desenvolvidos mostraram que altas concentrações de colesterol induzem redução da área por lipídeo e difusão lateral e aumento na espessura da membrana e nos valores de parâmetro de ordem causados pelo ordenamento das cadeias acil dos fosfolipídeos. As bicamadas lipídicas obtidas podem ser usadas para simular interações entre lipídeos e pequenas moléculas ou proteínas contribuindo para as pesquisas associadas a doenças como Alzheimer e Parkinson. As abordagens usadas nessa tese são essenciais para o desenvolvimento de novas pesquisas em Química Medicinal Computacional. / Different theoretical approaches have been used in the studies of biomolecular systems aiming to contribute with the treatment of several diseases. For neuropathic pain, for example, the study of compounds that interact with sigma-1 receptor (Sig-1R) can elucidate the main factors associated to their biological activities. For this purpose, studies of Quantitative Structure-Activity Relationships (QSAR) using Partial Least Squares (PLS) and Artificial Neural Network (ANN) methods were applied to 64 Sig-1R antagonists belong to 1-arylpyrazole class. PLS and ANN models were used in order to describe linear and nonlinear behavior, respectively, between a set of descriptors and the biological activity of the selected compounds. The PLS model was obtained with 51 compounds in the training set and 13 compounds in the test set (r² = 0.768, q² = 0.684 and r²test = 0.785). Leave-N-out tests, biological activity randomization and outliers detection confirmed the robustness and stability of the models and showed that they were not obtained by chance correlations. Models were also generated from Multilayer Perceptron Artificial Neural Network (MLP-ANN) and the 6-12-1 architecture, trained by tansig-tansig transfer functions, showed the best result for the biological activity prediction of the compounds (r²training = 0.891, r²validation = 0.852 and r²test = 0.793). Another approach was used to simulate synaptic membranes environment using lipid bilayers composed by POPC, DOPE, POPS and cholesterol. Performed molecular dynamics studies showed that high cholesterol concentration induces decrease of area per lipid and lateral diffusion and increase of membrane thickness and order parameter caused by ordering of phospholipids acil chains. The obtained lipid bilayers can be used to simulate interactions between lipids and small molecules or proteins contributing for researches associated to Alzheimer and Parkinson diseases. The approaches used in this thesis are essential for the development of new researches in Computational Medicinal Chemistry.
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Arquitetura de centros de pesquisas: um estudo de caso múltiplo quantitativo / Architecture of research centres: a quantitative multiple case studyBataglia, Érika Di Giaimo 06 May 2010 (has links)
O presente trabalho trata-se de um estudo de caso múltiplo de natureza quantitativa. Trata-se de um estudo descritivo em função da comparação e análise dos projetos de arquitetura e explicativo em função da aplicação da modelagem em equação estrutural. Foram visitados e analisados os centros de pesquisas: (A) Instituto Max Planck de Ecologia Química, localizado em Jena, Alemanha; (B) Instituto Max Planck de Antropologia Evolutiva, localizado em Leipzig, Alemanha; (C) Instituto Max Planck de Biologia e Genética de Célula Molecular, localizado em Dresden, Alemanha; (D) Instituto de Biociência, localizado em Liverpool, Inglaterra. Procedeu-se a aplicação de um questionário, para avaliar a percepção dos usuários com relação aos fatores que caracterizam os ambientes de trabalho e que se relacionam com a satisfação pelo ambiente físico. Os fatores extraídos da literatura e analisados foram: interação, privacidade, flexibilidade e percepção de conforto. Analisando as características físicas de cada edifício e os resultados do questionário, constata-se que estas características de fato têm sido percebidas pelos usuários. As evidências empíricas obtidas através do modelo de equação estrutural indicam: (1) que existe uma relação positiva entre condição física para interação e satisfação com o ambiente físico; (2) que existe uma relação positiva entre percepção de conforto e satisfação com o ambiente físico; (3) que existe uma relação positiva entre condição física para interação e condição física para privacidade. / This paper consists of a quantitative multiple case study presenting a descriptive analysis based on comparisons and examinations of architectural project designs, with an explanation of the structural equation modelling application. The following research centres were visited and analysed: (A) Max Planck Chemical Ecology Institute, Jena, Germany; (B) Max Planck Evolutionary Anthropology Institute, Leipzig, Germany; (C) Max Planck Biology and Molecular Cell Genetics Institute, Dresden, Germany; (D) Bioscience Institute, Liverpool, UK. A questionnaire was completed in order to assess user perceptions of factors characterising their work environments, related to satisfaction with their physical surroundings. The factors taken from the literature and analysed were: Interaction, Privacy, Flexibility and Perception of Comfort. Analyses of the physical characteristics of each building and the findings of the questionnaire clearly demonstrate that these characteristics are really perceived by their users. Empirical evidence obtained through the structural equation model indicates that: (1) there is a positive relationship between physical conditions conducive to interaction and satisfaction with physical surroundings; (2) there is a positive relationship between perception of comfort and satisfaction with physical surroundings; (3) there is a positive relationship between physical conditions conducive to interaction and physical conditions providing privacy.
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Les représentations de la proximité d'un magasin par les distributeurs et les consommateurs : une contribution à la stratégie de l'enseigne / Managers’ and consumers’ representations of the closeness to a store : a contribution to retailer strategySchultz, Maryline 02 December 2013 (has links)
La proximité constitue l’une des préoccupations stratégiques actuelles majeures de la distribution alimentaire. Cette recherche porte sur les raisons de la réhabilitation des formats de proximité et s’intéresse aux représentations de la proximité d’un magasin par les distributeurs et par les consommateurs. Il ressort des analyses qualitatives et quantitatives menées auprès des distributeurs et des consommateurs que cette distance spatiale, temporelle, fonctionnelle et social qui unit un magasin et ses clients est multidimensionnelle. Sept dimensions ont été identifiées : la proximité d’accès, la proximité fonctionnelle, la proximité de processus, la proximité relationnelle, la proximité identitaire, la proximité d’intégration et la proximité d’assortiment. Certains points de convergence et divergence apparaissent dans les représentations de la proximité d’un magasin par les distributeurs et les consommateurs. Plus généralement, tous deux perçoivent les aspects symboliques et fonctionnels du magasin de proximité. Les représentations de la proximité d’un magasin du point de vue des distributeurs sont plus complètes et positives ; les consommateurs se concentrent davantage sur les aspects fonctionnels et utilitaires du magasin de proximité. Le test des hypothèses du modèle théorique (PLS) nous amènent finalement à identifier les antécédents de la proximité perçue d’un magasin (positionnement perçu et localisation géographique) et ses conséquences (intentions d’achat futures, évaluation positive et attachement). Nos résultats démontrent que la localisation géographique ne suffit pas à créer une relation entre client et le magasin. Le distributeur ne doit pas se contenter d’être géographiquement près de son client pour être proche de lui ; il doit dépasser la vision géographique de la proximité pour valoriser d’autres aspects fonctionnels et symboliques / Getting close to the consumer is one major concern in retailing. This research tries to understand the rehabilitation of small food stores in the French retailing context and explores the notion of closeness in all in its dimensions from a retailer as well as a consumer perspective. The research involves data collection from both retail companies and consumers. The qualitative and quantitative analysis show that creating closeness with the customer can be defined as the management of the spatial, temporal, functional and social distance that links a store to its customers. Seven dimensions can be identified: the access closeness, the functional closeness, the process closeness, the relational closeness, the identity closeness, the integration closeness and the assortment closeness. Some convergence or difference points between the retailers and the consumers perceptions can be describe. In general, managers and consumers both establish a dichotomy between practical and symbolic aspects of closeness. We can observe that managers see the relationship between the store and its clients in a more positive and global way whereas consumers are more rational and focus on practical elements. The tests of the hypothesis show us that the retailer image and the geographical location of the store have both a positive effect on perceived closeness to a store. Also, perceived closeness to a store increases consumer’s loyalty to the store. Our results demonstrate that location of the store is not enough to create a close relationship between the customer and the store; the closeness between a customer and a store is not only based on a spatial distance but also on a temporal, functional and social distance. Being close to its consumers not only means being close to them geographically. The consumer prefers a broader vision of closeness including practical and symbolic aspects
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Effets masqués en analyse prédictive / Masked effects in predictive analysisBascoul, Ganaël 27 June 2013 (has links)
L’objectif de cette thèse consiste en l’élaboration de deux méthodologies visant à révéler des effets jusqu’alors masqués en modélisation décisionnelle. Dans la première partie, nous cherchons à mettre en œuvre une méthode d’analyse locale des critères de choix dans un contexte de choix binaires. Dans une seconde partie, nous mettons en avant les effets de génération dans l’étude des comportements de choix. Dans les deux parties, notre démarche de recherche combine de nouveaux outils d’analyse prédictive (Support Vector Machines, FANOVA, PLS) aux outils traditionnels de statistique inférentielle, afin d’enrichir les résultats habituels par des informations complémentaires sur les effets masqués que constituent les effets locaux dans les fonctions de choix binaires, et les effets de génération dans l’analyse temporelle des comportement de choix. Les méthodologies proposées, respectivement nommées AEL et APC-PLS, sont appliquées sur des cas réels, afin d’en illustrer le fonctionnement et la pertinence. / The objective of this thesis is the development of two methodologies to reveal previously hidden effects in decision modeling. In the first part, we try to implement a method of local analysis in order to select criteria in the context of binary choices. In a second part, we highlight the effects of generations in the study of consumer behavior. In both parts, our research approach combines new predictive analytical tools (such as Support Vector Machines, FANOVA, PLS) to traditional tools of inferential statistics, to enrich the usual results by additional on the masked effects, which are the local effects in the binary choice functions, and the effects of generation in temporal choice behavior analysis.The proposed methodologies, respectively named AEL and APC- PLS are both applied to real cases in order to illustrate their operation and relevance.
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Síntese e caracterização de nanocompósitos do tipo polímero/silicatos lamelares com propriedades anisotrópicas via polimerização RAFT em emulsão / Synthesis and characterization of polymer/layered silicate nanocomposites with anisotropic properties via RAFT emulsion polymerizationSilva, Rafael Caetano Jardim Pinto da 27 September 2013 (has links)
Nos últimos anos, a incorporação de partículas inorgânicas em uma matriz polimérica com a finalidade de se obter sistemas híbridos orgânico/inorgânico utilizando diferentes técnicas de polimerização tem recebido grande atenção. Neste sentido, preservar e controlar as propriedades físico-químicas das partículas inorgânicas torna-se essencial para manter a integridade destas em nanoescala, bem como para obtenção de dispersões uniformes, magnificando os efeitos de reforço e demais ganhos de propriedades desejadas para a matriz polimérica. Quando se utiliza partículas inorgânicas anisotrópicas tais como a montmorilonita, silicato lamelar mais utilizado para obtenção de nanocompósitos do tipo polímero/silicato lamelar, este controle apresenta-se como um problema particularmente desafiador. Nesse contexto, a polimerização radicalar controlada (PRC) vem se destacando como uma importante via para atingir os objetivos mencionados acima, encontrando-se na literatura diversas estratégias de síntese em meio a solventes orgânicos na qual a efetiva nanoencapsulação de partículas inorgânicas dá-se por meio do crescimento de cadeias poliméricas na superfície destas estruturas inorgânicas. Entretanto, poucos trabalhos são encontrados envolvendo rota de obtenção semelhante em meio aquoso, tais como suspensão, emulsão e miniemulsão, processos estes que possuem grande interesse industrial, ambiental e viabilidade real de ampliação de escala quanto à produção.Desta forma, o objetivo deste projeto de pesquisa concentra-se na síntese e na caracterização de nanocompósitos do tipo polímero/silicato lamelar via polimerização radicalar controlada em emulsão. As polimerizações radicalares controladas de estireno em emulsão, via mecanismo de transferência reversível de cadeia por adição-fragmentação (RAFT), foram conduzidas na presença de argila montmorilonita (MMT) e mediadas por dois macroagentes de transferência de cadeia com grupo funcional tri-tioéster, sendo o primeiro constituído de cadeia polimérica não iônica de monoetil éter de poli(etilenoglicol) (MPEG-CPP) e outro derivado do MPEG-CPP contendo adicionalmente um bloco ionizável de poli(ácido metacrílico) incorporado à cadeia polimérica (MPEG-b-PMAA-CPP). Foram avaliados inicialmente os parâmetros de adsorção dos macroagentes MPEG-CPP e MPEG-b-PMAA-CPP na superfície da MMT bem como a influência das variáveis do processo de polimerização na adsorção dos macroagentes na MMT e na estabilidade coloidal dos complexos macroagente RAFT / MMT formados. Posteriormente foram avaliados os efeitos do pH, das concentrações dos macroagente RAFT e de MMT, bem como do tipo de iniciador na cinética de polimerização em emulsão \"ab-initio\" de estireno, conduzidas na ausência de surfatantes. As técnicas utilizadas nos estudos de adsorção e para a caracterização das argilas, dos látices híbridos e dos materiais nanocompósitos incluem: espectroscopia de UV-vis, espalhamento dinâmico de luz (DLS), espalhamento eletroforético de luz (ELS), cromatografia de permeação em gel (GPC), análise termogravimétrica (TGA), calorimetria diferencial de varredura (DSC) e microscopia eletrônica de transmissão (TEM). / In recent years, the incorporation of inorganic particles in a polymer matrix in order to obtain hybrid organic/inorganic systems using different polymerization techniques have received great attention. In this sense, preserve and manage the physical and chemical properties of inorganic particles is essential to maintain its integrity at the nanoscale, as well as to obtain uniform dispersions of them, magnifying the effects of reinforcement and other desired properties into the polymer matrix. When using anisotropic inorganic nanoobjects such as montmorillonite, the most used layered silicate to obtain polymer / layered silicate nanocomposites, this control is presented as a particularly challenging problem. In this context, the controlled radical polymerization (CRP) has been highlighted as an important way to achieve the goals mentioned above, several strategies of organic solvent-borne synthesis can be found in literature in which the effective nanoencapsulation of inorganic particles is given by through the growth of polymer chains on the surface of these inorganic structures. However, few works are found involving obtaining similar route in water-borne, such as suspension, emulsion, miniemulsion, these procedures have great interest in industrial, environmental and actual feasibility of expanding scale in manufacture. Thus, the objective of this research project focuses on the synthesis and characterization of nanocomposite-type polymer / layered silicate via controlled radical polymerization in emulsion media. The controlled radical polymerizations in emulsion, via transfer mechanism for the reversible addition-fragmentation chain (RAFT) have been conducted in the presence of montmorillonite clay (MMT) and mediated by two macroRAFT agents with functional tri-thioesters groups, being the first one constituted by a nonionic poly(ethylene glycol) methyl ether polymeric chain (MPEG-CPP) and the second on being MPEG-CPP derived but containing additionally an ionizable block of poly(methacrylic acid) inserted to its polymeric chain. The parameters of adsorption of MPEG-CPP and MPEG-b-PMAA-CPP agent on the surface of MMT as well as the influence of the polymerization process variables on the adsorption of PEO-RAFT in MMT and colloidal stability of the complex formed macroRAFT agents / MMT were firstly evaluated. Subsequently, the influence of pH, macroRAFT agents and MMT concentrations as well as the type of initiator on the kinetics of RAFT emulsion polymerization were equally evaluated. The techniques used the for adsorption studies and characterization of clays, latexes of hybrid materials and nanocomposites include: UV-vis spectroscopy, dynamic light scattering (DLS), electrophoretic light scattering (ELS), gel permeation chromatography (GPC), thermogravimetric analysis (TGA), dynamic scanning calorimetry (DSC) and transmission electron microscopy (TEM).
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Ferramentas quimiom?tricas aplicadas a classifica??o de amostras de leite em p? e quantifica??o de prote?nas / Ferramentas quimiom?tricas aplicadas a classifica??o de amostras de leite em p? e quantifica??o de prote?nasIn?cio, Maria Raquel Cavalcanti 24 February 2010 (has links)
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Previous issue date: 2010-02-24 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / In this work we used chemometric tools to classify and quantify the protein content in samples of milk powder. We applied the NIR diffuse reflectance spectroscopy combined with multivariate techniques. First, we carried out an exploratory method of samples by principal component analysis (PCA), then the classification of independent modeling of class analogy (SIMCA). Thus it became possible to classify the samples that were grouped by similarities in their composition. Finally, the techniques of partial least squares regression (PLS) and principal components regression (PCR) allowed the quantification of protein content in samples of milk powder, compared with the Kjeldahl reference method. A total of 53 samples of milk powder sold in the metropolitan areas of Natal, Salvador and Rio de Janeiro were acquired for analysis, in which after pre-treatment data, there were four models, which were employed for classification and quantification of samples. The methods employed after being assessed and validated showed good performance, good accuracy and reliability of the results, showing that the NIR technique can be a non invasive technique, since it produces no waste and saves time in analyzing the samples / Neste trabalho foram utilizadas ferramentas quimiom?tricas para classificar e quantificar o teor de prote?nas em amostras de leite em p?. Empregou-se a espectroscopia NIR com reflect?ncia difusa associada a t?cnicas multivariadas. Primeiramente, realizou-se um m?todo explorat?rio das amostras atrav?s da an?lise das componentes principais (PCA),em seguida a classifica??o de modelagem independente para analogia de classes (SIMCA). Dessa forma se tornou poss?vel classificar as amostras que se agruparam por semelhan?as em sua composi??o. Por fim, as t?cnicas de regress?o por m?nimos quadrados parciais (PLS) e regress?o por componentes principais (PCR) permitiram a quantifica??o do teor de prote?nas nas amostras de leite em p?, comparadas com o m?todo de refer?ncia Kjeldahl. Um total de 53 amostras de leite em p? comercializadas nas regi?es metropolitanas de Natal, Salvador e Rio de Janeiro foram adquiridas para an?lise, em que ap?s pr?-tratamento dos dados obtidos, foram encontrados quatro modelos, os quais empregaram-se para a classifica??o e quantifica??o das amostras. Os m?todos empregados ap?s serem avaliados e validados apresentaram bom desempenho, demonstrando exatid?o e confiabilidade nos resultados obtidos, mostrando que a t?cnica NIR pode ser uma t?cnica n?o invasiva, uma vez que n?o produz res?duos e ainda economiza tempo na an?lise das amostras
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Approches PLS linéaires et non linéaires pour la modélisation de multi-tableaux. Théorie et applicationsVivien, Myrtille 03 December 2002 (has links) (PDF)
Ce travail concerne les analyses multi-tableaux de données et plus particulièrement la régression. Présentées sous forme d'un recueil, nous exposons un grand nombre de méthodes peu connues pour la majorité, pour l'analyse des multi-tableaux.<br /><br />Notre travail se compose de trois parties. La première partie, contenant sept chapitres, expose les méthodes de modélisation linéaires. Elles sont classées par type d'analyse (conjointe ou régression) et par domaine d'application (cube ou multi-tableaux). Nous en introduisons plusieurs nouvelles de type PLS, basées sur l'optimisation d'un critère sous contraintes par étape, pour analyser simultanément un (ACIMO) ou plusieurs (ACIMOG1,2, 3) ensembles de tableaux, pour modéliser un ensemble de tableaux par un autre (ACIMO-PLS, ACIMOG-PLS1,2 3, REMUB) et appliquons l'ACIMO à l'intrastructure de STATIS pour en améliorer les trajectoires. De plus, nous proposons une généralisation de la méthode STATIS au cas de deux ensembles de tableaux (DO-ACT), aussi basée sur l'optimisation d'un critère sous contraintes. <br /><br />Un chapitre est consacré à ce qui touche la pratique de ces méthodes, dans lequel nous abordons la question du choix de blocs explicatifs importants dans les modèles de régression multi-tableaux, qui n'a encore jamais été abordée. Nous proposons plusieurs critères pour répondre à cela.<br /><br />La seconde partie, moins importante en taille, concerne la modélisation non-linéaire en régression multi-tableaux. Après une revue des méthodes de régression PLS non-linéaire pour deux tableaux, nous introduisons deux méthodes (SARMUB1 et 2) pour la régression non-linéaire des multi-tableaux, basées sur la recherche de transformations splines des prédicteurs optimales. Enfin, nos méthodes, programmées en S-Plus, ayant pour but principal d'être appliquées, nous proposons dans la troisième partie les résultats de plusieurs applications dans divers domaines, tels que la chimiométrie, l'analyse sensorielle, l'écologie ...
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Spezies- und Tieraltersbestimmung von Geweben des zentralen Nervensystems anhand des FettsäuremustersGrießbach, Maria 15 September 2010 (has links) (PDF)
Massiver wirtschaftlicher Schaden und der Verlust des Verbrauchervertrauens hervorgerufen durch die BSE - Krise führten zu einer radikalen Änderung in der Futtermittel- und Lebensmittelgesetzgebung. Neben diversen anderen Maßnahmen wurden u. a. das Gehirn und Rückenmark von über 12 Monate alten Wiederkäuern vom Gesetzgeber als so genanntes spezifiziertes Risikomaterialien (SRM) definiert. Die spezielle Entsorgung und das Verarbeitungsverbot dieser Materialien in Lebens- und Futtermitteln hatte zum Ziel die Infektkette zu unterbrechen und dadurch das Risiko einer Infektion mit dem BSE-Erreger für den Verbraucher zu senken.
Um die Einhaltung des Verarbeitungsverbotes von SRM in Lebensmitteln zu überprüfen, wurden diverse ZNS-Nachweisverfahren entwickelt. Jedoch ist keines, der hierfür entwickelten molekularbiologischen und immunochemischen Verfahren in der Lage sowohl Spezies, als auch Tieralter des nachgewiesenen ZNS zu bestimmen und damit eine potentielle Einordnung zum SRM zu ermöglichen. Darüber hinaus hat sich für fast alle ZNS-Marker der Einfluss von hohen Prozesstemperaturen als nachteilig für die Nachweisbarkeit erwiesen.
NIEDERER und BOLLHALDER (2001) entwickelten ein auf Fettsäureanalytik basierendes ZNS-Nachweisverfahren, welches am Institut für Lebensmittelhygiene der Universität Leipzig weiterentwickelt wurde. Vorteile dieses Verfahrens sind die hitzestabilen Marker und die Möglichkeit mit Hilfe von spezifischen Fettsäureverhältnissen Spezies und Tieralters des nachgewiesenen ZNS zu ermitteln. Somit ist es mit diesem Verfahren erstmals möglich das nachgewiesene ZNS der Gruppe der spezifizierten Risikomaterialien zuzuordnen.
Ziel dieser Arbeit war es, das am Institut für Lebensmittelhygiene weiterentwickelte Verfahren auf Praxistauglichkeit anhand eines externen Blindversuchs zu testen. Hierbei sollten mögliche Schwachstellen identifiziert und im weiterführenden Verlauf dieser Arbeit Lösungen erarbeitet werden. Für den Blindversuch wurden vom Max-Rubner-Institut, Standort Kulmbach, insgesamt 72 Brühwurstproben zur Verfügung gestellt, welche mittels des nach LÜCKER et al. (2005) beschriebenen Verfahrens untersucht wurden. Die Ergebnisse des Blindversuchs deuten auf eine grundsätzliche Eignung des Verfahrens für den Nachweis von spezifiziertem Risikomaterial in Fleischerzeugnissen hin. Jedoch konnte bei der Tierartdifferenzierung und vor allem bei der Altersbestimmung ein Optimierungsbedarf ermittelt werden. Somit ergaben sich für diese Arbeit folgende weiterführende Aufgabenstellungen:
1. Die Optimierung der Tierartbestimmung auch im Hinblick auf Erweiterung des Speziesspektrums und
2. die Optimierung der Tieraltersbestimmung von Rinder- und Schaf-ZNS.
Insgesamt 257 ZNS-Proben der Spezies Rind, Schaf, Schwein, Ziege und Geflügel wurden einer Fettsäureanalyse unterzogen. Aus allen analysierten Fettsäuren wurden 67 Fettsäureverhältnisse gebildet. Zur Identifikation für die Speziesdifferenzierung geeigneter Fettsäureverhältnisse wurde das statistische Verfahren der Partial Least Square – Discriminant Analysis (PLS-DA) eingesetzt. Hierbei ergab sich, dass von den 67 untersuchten Fettsäureverhältnissen insgesamt 14 für die Differenzierung zwischen den Tierarten Rind, Schwein, Schaf, Ziege und Geflügel geeignet sind.
Für die Optimierung der Tieraltersbestimmung wurden 37 ZNS-Proben vom Rind und elf ZNS-Proben vom Schaf untersucht. Die analysierten Fettsäuren wurden auf ihre Korrelation mit dem Alter untersucht. Stark korrelierende Fettsäuren und deren Verhältnisse wurden mit Hilfe der Regressionsanalyse auf ihre Vorhersagefähigkeit geprüft. Hierbei gelang die Identifikation von vier neuen Fettsäureverhältnissen. Für die Altersschätzung bei der Tierart Rind scheinen sich die FS-Verhältnisse 2OH-C24:0/2OH-C25:0 und 2OH-C24:1(n-7)/2OH-C25:0 am besten zu eignen. Für die Tierart Schaf sollten die Verhältnisse 2OH-C25:0/2OH-C26:0 und 2OH-C25:0/2OH-C26:1(n-7) bevorzugt eingesetzt werden. Im Vergleich zur bisherigen Verfahrensweise ist mit Hilfe dieser Fettsäureverhältnisse und deren Regressionsformeln eine deutlich präzisere Altersschätzung für die Tierarten Rind und Schaf möglich. Der neue Ansatz bietet die Möglichkeit flexibel auf zukünftige Änderungen der Altersgrenze von SRM zu reagieren. / The immense economical damage and the loss of consumer trust caused by the bovine spongiform encephalopathy (BSE) - crisis resulted in a radical alteration of the feed- and foodlegislation. Besides several other measures, the legislator defined the brain and spinal cord of ruminants older than 12 month as specified risk material (SRM). The special disposal and the processing prohibition of these materials in food and feedstuffs aimed to interrupt the infection chain and to reduce the risk of an infection caused by the BSE pathogen for the consumer.
In order to control the processing prohibition of SRM in food, several CNS detection methods were developed. But none of the designed molecular biological or immuno chemical methods has the ability to detect species and age of the CNS. Therefore, a classification of the detected CNS as SRM is not possible. Furthermore, high process temperatures influence nega-tively the detection of almost all CNS markers.
NIEDERER and BOLLHALDER (2001) developed a CNS detection procedure based on the analysis of fatty acids, which was improved at the Institute of Food Hygiene, University Leipzig.
Advantages of this procedure are the heat stability of the markers and the possibility to identify species and age of the detected CNS. Therefore, this procedure is the first, which facilitates the potential of identifying SRM.
The aim of this work was to test the practicability of the improved CNS detection procedure in an external blind trial. During this, possible weak points should be identified and solutions for their elimination presented. Furthermore, the sample preparation of the method should be optimized with regard to cost and time reduction.
For the external blind trial the Max-Rubner-Institute, Kulmbach, produced 72 emulsion type sausages. These sausages were analysed according to the procedure described by LÜCKER et al. 2005. The results of the blind trial show the suitability of the procedure for the detection of SRM in meat products in principle. However, some results revealed that the species and age identification required further enhancement.
Therefore, the following additional topics of this work were:
1. Optimization of species identification especially with regard to other species
2. Optimization of animal age prediction for cattle and sheep CNS.
Selected fatty acids of total 257 CNS samples from cattle, pig, sheep, goat and several poultry species were analysed. These fatty acids were combined to 67 fatty acid ratios. Afterwards, the application of these ratios for the species detection was tested by using the statistical method of Partial Least Square – Discriminant Analysis (PLS-DA). In result, 14 out of 67 fatty acid ratios are suitable for differentiation between the species cattle, pig, sheep, goat and poultry.
For the optimization of animal age prediction 37 CNS samples from cattle and eleven CNS samples from sheep were examined. All analyzed fatty acids were checked for their correlation with age. Afterwards strong correlating fatty acids and their fatty acid ratios were examined for their predictive ability by the application of regression analysis. In result, four new fatty acid ratios for age prediction could be identified. For the age prediction of cattle CNS the fatty acid ratios 2OH-C24:0/2OH-C25:0 and 2OH-C24:1(n-7)/2OH-C25:0 are the best choice.
In sheep CNS the ratios 2OH-C25:0/2OH-C26:0 and 2OH-C25:0/2OH-C26:1(n-7) should be preferred for prediction of age. In comparison to the previous age prediction method, the application of these fatty acid ratios and their regression formula led to more accurate results. Furthermore, it offers the possibility to adopt to possible variations of the age limits within the SRM definition in future.
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