A produtividade de soja no mundo aumenta há décadas, em razão do avanço genético e das técnicas de cultivo e, em especial, pelo avanço da ciência na melhoria da fixação biológica de nitrogênio (FBN), nutriente exigido em grande quantidade pela soja. Existe a hipótese que a quantidade de nitrogênio (N) fornecida pela FBN e pelo solo não sejam suficientes para dar continuidade ao aumento da produtividade média hoje atingida (3 Mg ha-1), ou seja, o N seria o fator limitante para a soja. Essa hipótese é reforçada quando consideramos que o cultivo de soja é realizado em solos com baixo fornecimento de N, e em condições subótimas para a FBN. Neste contexto, seria necessário a adubação nitrogenada para complementar a demanda da cultura pelo nutriente. Dessa forma, caberia o uso da adubação nitrogenada para complementar a demanda da soja pelo N? A demanda de N pela soja, pode até ser complementada via fertilização. Entretanto, a mesma só faz sentido se não houver prejuízo à FBN, processo que sempre deve ser priorizado. Esta pesquisa teve como objetivo verificar a produtividade da soja e, compreender a resposta da planta à fertilização nitrogenada, no que diz respeito ao aproveitamento do N do fertilizante e sua influência na FBN. Para tanto, foram realizados dois anos de experimentos em ambiente tropical (Cerrado, Estado do Mato Grosso) e subtropical (sul do Estado de São Paulo). As fontes de variação experimentais foram doses (0, 20, 40, 80 e 120 kg ha-1) de N, e épocas de aplicação do fertilizante (VE, e R3) utilizando ureia aplicada com incorporação ao solo. Outro experimento foi realizado com a aplicação de ureia em baixas doses (650, 1300 e 1950 g ha-1 de N) em R1 ou R3 em Ambiente subtropical. Em ambos experimentos, foi utilizado o N marcado com o isótopo 15N. Não houve resposta produtiva da soja às doses de N aplicadas. Entre as épocas de aplicação, foi verificado que em uma das safras no Cerrado, houve maior produtividade (400 kg ha-1) com o fornecimento de N em R3. Porém essa resposta é obtida em determinadas condições ambientais, ou seja, o fornecimento de N não é garantia de aumento de produção, e a resposta é incerta. Houve redução da FBN, em porcentagem (% de N na planta derivado da atmosfera), da ordem de 15% entre a soja sem N e a soja com 120 kg N ha-1. A extração de N total foi 8% maior com a adubação em R3. O aumento do N (20 kg ha-1) da parte aérea com a aplicação em R3 no Cerrado, acompanhou o aumento de produtividade, mas esse aumento não foi provocado pelo N derivado do fertilizante (Ndff). A eficiência de uso do N (NUE) apresentou valores próximos a 50%, e, foi semelhante entre as duas épocas de aplicação de N em ambos os ambientes. No outro experimento, o fornecimento de N foliar não aumentou a produtividade, embora a NUE seja alta, com média de 64%. / The soybean yield in the world has been increasing for decades, due to the cultivation techniques, the cultivars, and the advancement of science in improving the biological nitrogen fixation (BNF), nutrient required in large quantities for soybeans. There is hypothesis that the quantity of nitrogen (N) provided by the BNF and soil are not enough to continue to increase yields today achieved (3 Mg ha-1), or N would be the limiting factor for soybeans. This hypothesis is reinforced when we consider that soybean cultivation is carried out in soils with low N supply, and suboptimal conditions for BFN. In this scenario, it would be the use of nitrogen fertilizer to supplement the soybean demand for N? The demand of N by soybeans may even be supplemented via fertilization. However, it only makes sense if there is (NUE) o damage to the BFN, a process that should always be prioritized. Many experiments with supply of mineral N have been conducted. Some tested negative, others positive. Producers are also conducting nitrogen fertilization in soybean, without proper knowledge of the subject. This study aimed to evaluate the production of soybean response, and understand the reaction of the plant to nitrogen fertilization, with regard to the use of N fertilizer and its influence on BFN. For that, two years of experiments were performed in tropical environment (Cerrado, Mato Grosso) and subtropical (southern state of São Paulo). The experimental variation sources were nitrogen rates, and fertilizer application times, using N marked with the 15N isotope. The application of nutrients has been tried in the soil, and also in soybean leaves. Verified productive soybean response to the supply of N in the Cerrado where the amount of N available to the crop is low. However such response is achieved under certain environmental conditions or N supply is no guarantee production increase, and the response is uncertain. The BFN is reduced, if not in absolute terms (kg ha-1 de N fixed by FBN), in percentages (% of N at plant from atmosphere). The total N extraction was always higher with fertilization in R3, and the Cerrado environment the application at this stage caused increased yeld, but only in one crop season. Increasing Number of shoot with the application in R3 in Primavera do Leste, accompanied the increase in productivity, but this increase was not caused by N fertilizer (Ndff). The N use efficiency showed values close to 50% and was similar between the two N application timing in both environments. In the tropical environment NUE decreased with increasing N rate. In subtropical environment NUE was constant. The supply of leaf N did not increase productivity, although the NUE is high, averaging 64%.

Espera-se que entre 2010 e 2050, a população mundial total terá um aumento de 2 bilhões de habitantes, ao passo que a população idosa chegará ao número de 1,3 bilhões de habitantes. Dentre os diversos fatores envolvidos com expectativa de vida longa, está bem estabelecido que o hábito alimentar desempenha um papel central para a saúde, o que torna importante o conhecimento do padrão alimentar nesta faixa etária. Para a avaliação da ingestão alimentar média a longo prazo em grande número de indivíduos, os Questionários de Frequência de Alimentos (QFAs) são instrumentos particularmente importantes. Objetivo: validar um questionário de frequência alimentar para idosos saudáveis. Casuística e Métodos: Participaram da pesquisa 43 idosos independentes, com a capacidade cognitiva e funcional preservadas, de ambos os gêneros, com idades > 60 anos. Foi avaliado o consumo alimentar dos indivíduos por meio de 3 recordatórios alimentares de 24 horas e um questionário de frequência alimentar, com o auxílio de um livro de fotografias para visualização do tamanho das porções dos alimentos. Como método padrão-ouro, foi utilizada a água duplamente marcada (DLW) para aferição do gasto energético total diário. Para a análise estatística, foi realizada análise descritiva dos dados, calculado o coeficiente de correlação de Spearman, construídos gráficos de dispersão e de Bland-Altman, e também o Coeficiente de Correlação Intraclasse (ICC). Foi adotado o nível de significância de 5%. Resultados: foi observada excelente concordância entre o QFA e DLW para estimativa do consumo de energia em mulheres idosas, assim boa correlação entre o R24h e DLW para estimativa do consumo de energia em homens idosos. Não foram encontradas correlações significativas entre o QFA e DLW para estimativa do consumo de energia em ambos os sexos. Conclusão: Considerando que o objetivo desta pesquisa foi validar o QFA para os dois gêneros (homem e mulher), o mesmo não foi alcançado. / Introduction: It is expected that between 2010 and 2050, the total world population will increase by 2 billion inhabitants, while the elderly population will reach 1.3 billion. Among the many factors involved in long life expectancy, it is well established that eating habits play a central role in health, which makes it important to know the food pattern in this age group. For the evaluation of the long-term average food intake in a large number of individuals, Food Frequency Questionnaires (FFQs) are particularly important instruments. Objective: to validate a food frequency questionnaire for healthy elderly. METHODS: Participants were 43 independent, with cognitive and functional capacity, of both genders, aged> 60 years. The individuals\' food consumption was evaluated through three 24-hour recalls and a food frequency questionnaire, with the aid of a photo book to visualize the size of the food portions. As a gold standard method, double-labeled water (DLW) was used to measure total daily energy expenditure. For the statistical analysis, a descriptive analysis of the data was performed, the Spearman correlation coefficient was calculated, the dispersion and Bland-Altman graphs were constructed, as well as the Intraclass Correlation Coefficient (ICC). The significance level of 5% was adopted. Results: excellent concordance was observed between the QFA and DLW for estimation of energy consumption in elderly women, thus a good correlation between R24h and DLW for estimation of energy consumption in elderly men. No significant correlations were found between the QFA and DLW to estimate the energy consumption in both sexes. Conclusion: Considering that the objective of this research was to validate the FFQ for both genders (man and woman), the same was not achieved.

Standard chemical DNA synthesis with isotope labels requires expensive reagents; moreover, a large excess of phosphoramadites (typically 50-100 fold) must be used. We developed a process where enzymatic cyclic solid phase synthesis of DNA allows for more economic reagent use. A DNA template was immobilized on an epoxy-activated solid support. This chemistry was chosen because the formed linkage is inert to high pH conditions. High efficiency of the covalent attachment was observed when the reaction was carried out in MgCl2/CAPS buffer. It was found that Mg2+ enables the reaction to be completed over a period of 14 h, compared to 72 h under standard conditions. DNA synthesis was carried in a cyclic fashion on a support bound DNA using Klenow fragment.

Keyword queries are extremely easy for a user to write. They have become a standard way to query for information in web search engines and most other information retrieval systems whose users are usually laypersons and might not have knowledge about the database schema or contained data. As keyword queries do not impose any structural constraints on the retrieved information, the quality of the obtained results is far from perfect. However, one can hardly improve it without changing the ways the queries are asked and the methods the information is stored in the database. The purpose of this thesis is to propose a method to improve the quality of the information retrieving by adding weights to the existing ways of keyword queries asking and information storing in the database. We consider weighted queries on two different data structures: weighted binary relations and weighted multi-labeled trees. We propose adaptive algorithms to solve these queries and prove the measures of the complexity of these algorithms in terms of the high-level operations. We describe how these algorithms can be implemented and derive the upper bounds on their complexity in two specific models of computations: the comparison model and the word-RAM model.

Keyword queries are extremely easy for a user to write. They have become a standard way to query for information in web search engines and most other information retrieval systems whose users are usually laypersons and might not have knowledge about the database schema or contained data. As keyword queries do not impose any structural constraints on the retrieved information, the quality of the obtained results is far from perfect. However, one can hardly improve it without changing the ways the queries are asked and the methods the information is stored in the database. The purpose of this thesis is to propose a method to improve the quality of the information retrieving by adding weights to the existing ways of keyword queries asking and information storing in the database. We consider weighted queries on two different data structures: weighted binary relations and weighted multi-labeled trees. We propose adaptive algorithms to solve these queries and prove the measures of the complexity of these algorithms in terms of the high-level operations. We describe how these algorithms can be implemented and derive the upper bounds on their complexity in two specific models of computations: the comparison model and the word-RAM model.

H αλόγιστη απόρριψη των αγροτοβιομηχανικών αποβλήτων στο περιβάλλον προκαλεί σοβαρά προβλήματα παγκοσμίως. Πολλά από αυτά όπως π.χ. τυρόγαλα περιέχουν θρεπτικά συστατικά τα οποία μπορούν να χρησιμοποιηθούν από μικροοργανισμούς προς παραγωγή προϊόντων υψηλής προστιθέμενης αξίας. Στην παρούσα εργασία χρησιμοποιήθηκε ο ζυμομύκητας Kluyveromyces marxianus για την ζύμωση συνθετικού μέσου με λακτόζη συγκέντρωσης ανάλογης με εκείνη του τυρογάλακτος (~5% w/v) προς παραγωγή αιθανόλης. Προσδιορίσθηκαν οι βέλτιστες φυσικοχημικές συνθήκες και τα αποτελέσματα έδειξαν ότι σε pH 7 και 30οC επιτυγχάνεται μέγιστη ταχύτητα ζύμωσης και συγκέντρωση αιθανόλης. Στις ίδιες συνθήκες, μέτρηση του ρυθμού πρόσληψης λακτόζης επισημασμένης με 14C από τον μικροοργανισμό έδειξε ότι αυτός σχετίζεται άμεσα με την κινητική της ζύμωσης. / Τhe indiscriminate disposal of agro waste in the environment causes serious problems worldwide. However, many of them for example whey, contain nutrients which can be used by microorganisms in order to produce products with high value. In this study is being used the yeast Kluyveromyces Marxianus for the fermentation of synthetic substrate of lactose with lactose concentration similar to that of the whey (~5% w/v) for ethanol production. Having determined the optimal physicochemical conditions and the results showed that at pH 7 and 30οC achieved a maximum speed of fermentation and ethanol concentration. Under the same conditions, measuring the rate of uptake of 14C-labeled lactose by the microorganism showed that this is directly related to the kinetics of fermentation

Concurrence est concernée par les systèmes informatiques des agents multiples qui interagissent les uns avec les autres. Bisimilarité est l'un des principales représentantes de ces derniers. Programmation concurrente par contraintes (ccp) est un formalisme qui combine le point de vue traditionnel des formules algébriques et opérationnelles des calculs de processus avec une notion déclarative basée sur logique. La définition standard de bisimilarité n'est pas complètement satisfaisante pour ccp car il donne une équivalence qui est trop à grain fin. Nous introduisons une sémantique de transitions étiquetées et une notion de bisimilarité totalement abstraite à l'équivalence observationnelle en ccp. Lorsque l'espace d'état d'un système est fini, la notion ordinaire de bisimilarité peut être calculé par l'algorithme de partition de raffinement, mais, cet algorithme ne fonctionne pas pour la bisimilarité de ccp. Par conséquent, nous fournissons un algorithme que nous permet de vérifier bisimilarité forte pour ccp, en utilisant un pré-raffinement et une fonction de partition basée sur la bisimilarité irredondante. Bisimilarité faible est une équivalence comportementale obtenue en prenant en compte uniquement les actions qui sont observables dans le système. Typiquement, le raffinement de partition standard peut être utilisé pour décider bisimilarité faible simplement en utilisant la réduction de Milner allant de faible à forte. Nous démontrons que, en raison de ses impliquées transitions étiquetées, la technique mentionnée ci-dessus ne fonctionne pas pour ccp. Nous donnons une réduction qui nous permet d'utiliser cet algorithme pour ccp pour décider cette équivalence.

In the middle of the 1990s many adolescents became vegetarians. There was concern among adults about whether these new young vegetarians got enough energy and nutrients from their dietary intake. The aim of this thesis was to investigate the prevalence of young vegetarians, the food and lifestyle habits, dietary intake and nutritional status of vegetarian and omnivorous adolescents. The prevalence of adolescents eating a vegetarian school lunch in 124 Swedish secondary schools was investigated by interviewing matrons. Information about prevalence of vegetarians, food and lifestyle habits, of 2041 15-year old students from Umeå, Stockholm and Bergen, was obtained by a questionnaire. The dietary intake and nutritional status of thirty 16-20 year-old vegans were compared with thirty age, sex and height matched omnivores. Five percent of the adolescents (16-20 years) in Sweden were found to eat vegetarian food at school lunch. In Umeå there was a significantly higher prevalence (15.6%) of 15-year-old vegetarians compared with Stockholm (4.8%) and Bergen (3.8%). It was also found that more females than males (15 years old) chose a vegetarian dietary regime. Even though the female vegetarians consumed vegetables significantly more often than the omnivores, the intake (32 times/month) was not as often as might be expected of a vegetarian population. The male vegetarians reported eating vegetables not even once a day (25 times/month). No difference in the consumption frequency of fruits/berries, alcoholic beverages, sweets/chocolates and fast foods was seen between vegetarians and omnivores. However, female vegetarians more often than female omnivores consumed dietary supplements. Furthermore, lifestyle characteristics of vegetarians were similar those of omnivores regarding exercise, use of alcohol and smoking habits. No significant difference in validity of reported energy expenditure or energy and protein intakes was found between vegans and omnivores. Young vegans (16-20 year-olds) were seen to have a higher calculated intake of vegetables, legumes, and dietary supplements and a lower intake of ice creams, cakes/cookies, and candies/chocolate than omnivores. The dietary intake was below the average requirements of riboflavin for 73% of the vegans, vitamin B12 for all vegans, vitamin D for 43% of the vegans, calcium for 77% of the vegans and selenium for all vegans and 43% of the omnivores. If intake of supplements was included the intake of e.g. calcium and selenium was still lower than the average requirements for 67% and 73% of the vegans respectively. Low iron stores were as prevalent among vegans as among omnivores (20% and 23% with low stores) and three vegans had low vitamin B12 concentrations in blood. The findings imply that food and lifestyle habits of young vegetarians are different than what previous studies of vegetarians have shown. There is a need for future research of the long-term health effects of being vegetarian.

Em cenas naturais, ocorrem com certa freqüência classes espectralmente muito similares, isto é, os vetores média são muito próximos. Em situações como esta dados de baixa dimensionalidade (LandSat-TM, Spot) não permitem uma classificação acurada da cena. Por outro lado, sabe-se que dados em alta dimensionalidade tornam possível a separação destas classes, desde que as matrizes covariância sejam suficientemente distintas. Neste caso, o problema de natureza prática que surge é o da estimação dos parâmetros que caracterizam a distribuição de cada classe. Na medida em que a dimensionalidade dos dados cresce, aumenta o número de parâmetros a serem estimados, especialmente na matriz covariância. Contudo, é sabido que, no mundo real, a quantidade de amostras de treinamento disponíveis, é freqüentemente muito limitada, ocasionando problemas na estimação dos parâmetros necessários ao classificador, degradando, portanto a acurácia do processo de classificação, na medida em que a dimensionalidade dos dados aumenta. O Efeito de Hughes, como é chamado este fenômeno, já é bem conhecido no meio científico, e estudos vêm sendo realizados com o objetivo de mitigar este efeito. Entre as alternativas propostas com a finalidade de mitigar o Efeito de Hughes, encontram-se as técnicas que utilizam amostras não rotuladas e amostras semi-rotuladas para minimizar o problema do tamanho reduzido das amostras de treinamento. Deste modo, técnicas que utilizam amostras semi-rotuladas, tornamse um tópico interessante de estudo, bem como o comportamento destas técnicas em ambientes de dados de imagens digitais de alta dimensionalidade em sensoriamento remoto, como por exemplo, os dados fornecidos pelo sensor AVIRIS. Neste estudo foi dado prosseguimento à metodologia investigada por Lemos (2003), o qual implementou a utilização de amostras semi-rotuladas para fins de estimação dos parâmetros do classificador Máxima Verossimilhança Gaussiana (MVG). A contribuição do presente trabalho consistiu na inclusão de uma etapa adicional, introduzindo a estimação das probabilidades a priori P( wi) referentes às classes envolvidas para utilização no classificador MVG. Desta forma, utilizando-se funções de decisão mais ajustadas à realidade da cena analisada, obteve-se resultados mais acurados no processo de classificação. Os resultados atestaram que com um número limitado de amostras de treinamento, técnicas que utilizam algoritmos adaptativos, mostram-se eficientes em reduzir o Efeito de Hughes. Apesar deste Efeito, quanto à acurácia, em todos os casos o modelo quadrático mostrou-se eficiente através do algoritmo adaptativo. A conclusão principal desta dissertação é que o método do algoritmo adaptativo é útil no processo de classificação de imagens com dados em alta dimensionalidade e classes com características espectrais muito próximas. / In natural scenes there are some cases in which some of the land-cover classes involved are spectrally very similar, i.e., their first order statistics are nearly identical. In these cases, the more traditional sensor systems such as Landsat-TM and Spot, among others usually result in a thematic image low in accuracy. On the other hand, it is well known that high-dimensional image data allows for the separation of classes that are spectrally very similar, provided that their second-order statistics differ significantly. The classification of high-dimensional image data, however, poses some new problems such as the estimation of the parameters in a parametric classifier. As the data dimensionality increases, so does the number of parameters to be estimated, particularly in the covariance matrix. In real cases, however, the number of training samples available is usually limited preventing therefore a reliable estimation of the parameters required by the classifier. The paucity of training samples results in a low accuracy for the thematic image which becomes more noticeable as the data dimensionality increases. This condition is known as the Hughes Phenomenon. Different approaches to mitigate the Hughes Phenomenon investigated by many authors have been reported in the literature. Among the possible alternatives that have been proposed, the so called semi-labeled samples has shown some promising results in the classification of remote sensing high dimensional image data, such as AVIRIS data. In this dissertation the approach proposed by Lemos (2003) is further investigated to increase the reliability in the estimation of the parameters required by the Gaussian Maximum Likelihood (GML) classifier. In this dissertation, we propose a methodology to estimate the a priory probabilities P( i) required by the GMV classifier. It is expected that a more realistic estimation of the values for the a priory probabilities well help to increase the accuracy of the thematic image produced by the GML classifier. The experiments performed in this study have shown an increase in the accuracy of the thematic image, suggesting the adequacy of the proposed methodology.

Em cenas naturais, ocorrem com certa freqüência classes espectralmente muito similares, isto é, os vetores média são muito próximos. Em situações como esta dados de baixa dimensionalidade (LandSat-TM, Spot) não permitem uma classificação acurada da cena. Por outro lado, sabe-se que dados em alta dimensionalidade tornam possível a separação destas classes, desde que as matrizes covariância sejam suficientemente distintas. Neste caso, o problema de natureza prática que surge é o da estimação dos parâmetros que caracterizam a distribuição de cada classe. Na medida em que a dimensionalidade dos dados cresce, aumenta o número de parâmetros a serem estimados, especialmente na matriz covariância. Contudo, é sabido que, no mundo real, a quantidade de amostras de treinamento disponíveis, é freqüentemente muito limitada, ocasionando problemas na estimação dos parâmetros necessários ao classificador, degradando, portanto a acurácia do processo de classificação, na medida em que a dimensionalidade dos dados aumenta. O Efeito de Hughes, como é chamado este fenômeno, já é bem conhecido no meio científico, e estudos vêm sendo realizados com o objetivo de mitigar este efeito. Entre as alternativas propostas com a finalidade de mitigar o Efeito de Hughes, encontram-se as técnicas que utilizam amostras não rotuladas e amostras semi-rotuladas para minimizar o problema do tamanho reduzido das amostras de treinamento. Deste modo, técnicas que utilizam amostras semi-rotuladas, tornamse um tópico interessante de estudo, bem como o comportamento destas técnicas em ambientes de dados de imagens digitais de alta dimensionalidade em sensoriamento remoto, como por exemplo, os dados fornecidos pelo sensor AVIRIS. Neste estudo foi dado prosseguimento à metodologia investigada por Lemos (2003), o qual implementou a utilização de amostras semi-rotuladas para fins de estimação dos parâmetros do classificador Máxima Verossimilhança Gaussiana (MVG). A contribuição do presente trabalho consistiu na inclusão de uma etapa adicional, introduzindo a estimação das probabilidades a priori P( wi) referentes às classes envolvidas para utilização no classificador MVG. Desta forma, utilizando-se funções de decisão mais ajustadas à realidade da cena analisada, obteve-se resultados mais acurados no processo de classificação. Os resultados atestaram que com um número limitado de amostras de treinamento, técnicas que utilizam algoritmos adaptativos, mostram-se eficientes em reduzir o Efeito de Hughes. Apesar deste Efeito, quanto à acurácia, em todos os casos o modelo quadrático mostrou-se eficiente através do algoritmo adaptativo. A conclusão principal desta dissertação é que o método do algoritmo adaptativo é útil no processo de classificação de imagens com dados em alta dimensionalidade e classes com características espectrais muito próximas. / In natural scenes there are some cases in which some of the land-cover classes involved are spectrally very similar, i.e., their first order statistics are nearly identical. In these cases, the more traditional sensor systems such as Landsat-TM and Spot, among others usually result in a thematic image low in accuracy. On the other hand, it is well known that high-dimensional image data allows for the separation of classes that are spectrally very similar, provided that their second-order statistics differ significantly. The classification of high-dimensional image data, however, poses some new problems such as the estimation of the parameters in a parametric classifier. As the data dimensionality increases, so does the number of parameters to be estimated, particularly in the covariance matrix. In real cases, however, the number of training samples available is usually limited preventing therefore a reliable estimation of the parameters required by the classifier. The paucity of training samples results in a low accuracy for the thematic image which becomes more noticeable as the data dimensionality increases. This condition is known as the Hughes Phenomenon. Different approaches to mitigate the Hughes Phenomenon investigated by many authors have been reported in the literature. Among the possible alternatives that have been proposed, the so called semi-labeled samples has shown some promising results in the classification of remote sensing high dimensional image data, such as AVIRIS data. In this dissertation the approach proposed by Lemos (2003) is further investigated to increase the reliability in the estimation of the parameters required by the Gaussian Maximum Likelihood (GML) classifier. In this dissertation, we propose a methodology to estimate the a priory probabilities P( i) required by the GMV classifier. It is expected that a more realistic estimation of the values for the a priory probabilities well help to increase the accuracy of the thematic image produced by the GML classifier. The experiments performed in this study have shown an increase in the accuracy of the thematic image, suggesting the adequacy of the proposed methodology.