Submitted by Setor de Tratamento da Informa??o - BC/PUCRS (tede2@pucrs.br) on 2015-09-03T12:00:12Z No. of bitstreams: 1 474518 - Texto Completo.pdf: 1324777 bytes, checksum: 8637f529b7e7e37f98207020149727e5 (MD5) / Made available in DSpace on 2015-09-03T12:00:12Z (GMT). No. of bitstreams: 1 474518 - Texto Completo.pdf: 1324777 bytes, checksum: 8637f529b7e7e37f98207020149727e5 (MD5) Previous issue date: 2014-08-29 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / This research has the objective of analyzing the current validity of the political-ideological dichotomy Right-Left approaching specifically the case of Liberalism and by questioning its position on the political spectrum. A historical panorama of this dichotomy is presented, since its emergence until contemporary times, coming to a brief debate about the current validity of the one-dimension political-ideological spectrum. Following, Liberalism is discussed as political philosophy and through its positions as such since its doctrinaire origins? with special attention to the development of liberal ideas in Brazil until today. After that, there will be an analysis of qualitative interviews made with eight leaders from seven of the most important institutions in so called ?liberal movement? in Brazil. The interviews aim at better understanding how these actors ? selected among founders and directing figures at the most highlighted organizations focused on defending liberal ideas in Brazil ? see the positioning of their own organizations and that of Liberalism regarding the one-dimension scale Left-Right. These interviews will allow a reflection on the perception of liberals about the suitability of this dichotomy, alternatives and the relation of liberals with politics. / A presente pesquisa tem por objetivo analisar a validade contempor?nea da dicotomia pol?tico-ideol?gica Direita-Esquerda abordando especificamente o caso do Liberalismo ao problematizar seu posicionamento no espectro pol?tico. Tra?a-se um panorama hist?rico da dicotomia, desde o seu surgimento at? a contemporaneidade, partindo para um breve debate sobre a validade atual da perspectiva unidimensional do espectro pol?tico-ideol?gico. Discute-se em seguida o Liberalismo como filosofia pol?tica e seus posicionamentos como tal desde suas origens doutrin?rias at? a atualidade. Ser? dada aten??o especial ao desenvolvimento das ideias liberais no Brasil at? os dias de hoje. Ap?s isso, analisaremos entrevistas qualitativas individuais realizadas com oito lideran?as de sete institui??es de destaque do chamado ?movimento liberal? no Brasil. O objetivo das entrevistas ? buscar uma melhor compreens?o sobre como estes atores ? selecionados dentre fundadores e membros dirigentes das institui??es mais destacadas como defensoras do ide?rio liberal ? enxergam o posicionamento de suas institui??es e do Liberalismo em rela??o ? escala unidimensional Esquerda-Direita. Estas entrevistas ensejar?o uma reflex?o sobre a percep??o dos liberais sobre a adequa??o da dicotomia, alternativas a essa perspectiva e a rela??o dos liberais com a pol?tica.

Submitted by Setor de Tratamento da Informa??o - BC/PUCRS (tede2@pucrs.br) on 2015-10-20T10:09:44Z No. of bitstreams: 1 475816 Texto Completo.pdf: 891315 bytes, checksum: 2f04cd28f1d31506ab10c98f28758679 (MD5) / Made available in DSpace on 2015-10-20T10:09:45Z (GMT). No. of bitstreams: 1 475816 Texto Completo.pdf: 891315 bytes, checksum: 2f04cd28f1d31506ab10c98f28758679 (MD5) Previous issue date: 2015-08-10 / The present study aims to establish a relationship between the thinking of Thomas Kuhn in Philosophy of Science and the thinking of Joseph Schumpeter for Economy, establishing a parallel between the concepts of "Scientific Revolution" proposed by Kuhn and "Creative Destruction" proposed by Schumpeter. Despite their interest in different areas, both Thomas Kuhn and Joseph Schumpeter considered that their fields have subjectivities related to human, social, and historical issues, and that organization and progress were the result of human understanding and its ensuing relations. To achieve this goal, we will discuss the central ideas of Thomas Kuhn, including the notions of ?paradigm?, ?normal science? and ?incommensurability?, as described in The Structure of Scientific Revolutions, Kuhn?s main work. We will also emphasize the historical context of Kuhn?s work by highlighting the most prominent Philosophy of Science thinkers preceding him, as well as Kuhn?s responses to the main criticisms to his work, especially "relativism" and "irrationalism." An additional aim of the present study is to describe the evolution of Economy until its establishment as a "normal science" from a Kuhnian perspective.This will be done by illustrating the development on economic thinking until its neoclassical formulation, and by showing the significant consolidation that Economy studies have achieved since the first ideas of Adam Smith. Joseph Schumpeter?s ideas will be detailed from the perspective of the evolution of economic thinking, revealing his estrangement, as also occurs with Kuhn, from traditional ideas of equilibrium of the economic system. We will show that Schumpeter introduces elements of disequilibrium in environments that were previously considered stable, such as consumer behavior and production techniques. Thomas Kuhn and Joseph Schumpeter seem to have understood, each in their own way, that the scientific and economic processes lack a set of neutral categories that are independent of culture, because human and historical aspects are always combined to produce our choices and behaviors. Therefore, absolute rationalism is denied by both thinkers, who assume disequilibrium and disruption as part of their study areas. / A presente disserta??o pretende estabelecer uma rela??o entre o pensamento de Thomas Kuhn na Filosofia da Ci?ncia e o pensamento de Joseph Schumpeter para a Economia, estabelecendo um paralelismo entre os conceitos de ?revolu??o cient?fica? em Kuhn e ?destrui??o criadora? em Schumpeter. Tanto Thomas Kuhn quanto Joseph Schumpeter, apesar de serem pensadores de ?reas distintas, consideravam que seus campos de estudo tinham subjetividades relacionadas a aspectos humanos, sociais, e hist?ricos, onde a organiza??o e progresso davam-se como resultado da compreens?o humana e de suas rela??es. Para tanto, iremos desenvolver as ideias centrais de Thomas Kuhn, como ?paradigma?, ?ci?ncia normal? e ?incomensurabilidade?, a partir de sua principal obra ?A Estrutura das Revolu??es Cient?ficas?. Tamb?m daremos ?nfase a seu contexto hist?rico a partir dos pensadores at? ali destacados na Filosofia da Ci?ncia, e sua resposta ?s principais cr?ticas recebidas, podendo-se destacar o ?relativismo? e o ?irracionalismo?. Este trabalho pretende tamb?m descrever a evolu??o da Economia at? seu estabelecimento como ?ci?ncia normal? a partir de uma perspectiva Kuhniana.Para tanto iremos ilustrar a evolu??o do pensamento econ?mico at? sua formula??o neocl?ssica, onde ser? poss?vel verificar a significativa consolida??o que os estudos da Economia alcan?aram desde as primeiras ideias de Adam Smith. As ideias do economista Joseph Schumpeter ser?o detalhadas a partir da evolu??o do pensamento econ?mico, revelando seu distanciamento, assim como em Kuhn, das ideias tradicionais de equil?brio do sistema econ?mico. Ser? poss?vel observar que Schumpeter colocou elementos de desequil?brio no que antes era considerado est?vel, como o comportamento do consumidor ou as t?cnicas de produ??o. Thomas Kuhn e Joseph Schumpeter parecem ter entendido cada a um seu modo, que no processo cient?fico e econ?mico, n?o h? um conjunto de categorias que sejam neutras e independentes da cultura, pois sempre haveria combina??es nas escolhas e nos comportamentos que teriam aspectos humanos e hist?ricos. Nesse sentido, o racionalismo absoluto ? negado por ambos, j? que consideravam o desequil?brio e a ruptura como parte integrante de suas ?reas de estudo.

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2016-10-04T19:57:29Z No. of bitstreams: 1 2006 - Elisangela Sousa de Araujo.pdf: 1061759 bytes, checksum: 865d0167431190cf5627ccdf21cf91fb (MD5) / Made available in DSpace on 2016-10-04T19:57:29Z (GMT). No. of bitstreams: 1 2006 - Elisangela Sousa de Araujo.pdf: 1061759 bytes, checksum: 865d0167431190cf5627ccdf21cf91fb (MD5) Previous issue date: 2006-02-23 / FAPERJ / CAPES / Brazil is the country with the greatest plant genetic diversity in the world with the potential still underestimated what makes it necessary to characterize local genetic material. Genetic resources are studie in several stages and identify traits of agronomic value in hardy varieties is one of the roles of gene banks (BAG's). In rice, because it is a very important crop for the diet of the brazilian population, selecting genotypes with high yield, nutritional value and adapted to the most diverse environmental conditions is a continuous search for improvement programs. In this sense, the present study aimed to adapt methodologies for protein extraction reserve and DNA of rice seeds to be used in routine laboratory for characterization of germplasm banks. After optimization of methodologies, seeds of twenty local varieties of rice grown in the state of Maranh?o different times (Experiment I: Aug-2002 to Mar-2003 and Experiment II: Nov-2002 to Jun-2003) were analyzed for study of diversity genetic (DNA and protein) and seasonality effect on its accumulation of reserves and gross protein. The analysis of variance or protein content and protein fractions was highly significant (P <0.01) between genotypes and experiments. The mean protein fractions albumin+globulin and glutelin were higher in experiment I, whose average temperatures were 330C while the average gross protein (CP) was higher than in Experiment II in which the average temperature was 410C.Varieties analyzed, the Pingo d? ?gua (220019) and Jatob? (220012) showed the highest values for PB (11.32 and 11.13%) and glutelin (83.73 and 92.86 mg flour). The molecular characterization by RAPD was based on 37 polymorphic band sand phylogenetic analysis revealed a genetic diversity at 50% training with four groups and three separate varieties. Groups based on the varieties named Lageado and Zebu branco seems to have been the shape of the grains and reason C/L. / O Brasil ? o pa?s com a maior diversidade gen?tica vegetal do mundo com potencial ainda subestimado o que torna fundamental a caracteriza??o do material gen?tico local. Os recursos gen?ticos s?o estudados em v?rias etapas e identificar caracter?sticas de valor agron?mico em variedades r?sticas ? um dos pap?is dos bancos de germoplasma (BAG?s). Em arroz, por se tratar de uma cultura muito relevante para a dieta da popula??o brasileira, selecionar gen?tipos com alta produtividade, valor nutricional e adaptados ?s mais diversificadas condi??es ambientais ? uma busca cont?nua em programas de melhoramento. Nesse sentido, o presente trabalho teve por objetivos adaptar metodologias para extra??o de prote?na de reserva e de DNA de sementes de arroz a fim de serem empregadas na rotina de laborat?rio para caracteriza??o de bancos de germoplasma. Ap?s otimiza??o das metodologias, sementes de vinte variedades locais de arroz do Estado do Maranh?o cultivadas em ?pocas distintas (Experimento I: Ago-2002 a Mar-2003 e Experimento II: Nov-2002 Jun-2003) foram analisadas para fins de estudo de diversidade gen?tica (DNA e prote?na) e efeito da sazonalidade em seu ac?mulo de prote?na bruta e reserva. A an?lise de vari?ncia para teor de prote?na e fra??es proteicas foi altamente significativa (P<0,01) entre os gen?tipos, e os experimentos. As m?dias das fra??es proteicas albumina+globulina e glutelina foram superiores no experimento I, cujas temperaturas m?dias foram de 330C enquanto que a m?dia da prote?na bruta (PB) foi superior no Experimento II em que a m?dia de temperatura foi de 410C. Das variedades analisadas, a Pingo d??gua (220019) e Jatob? (220012) foram as que apresentaram os maiores valores para PB (11,32 e 11,13%) e glutelina (83,73 e 92,86 mg.g farinha). A caracteriza??o molecular pela RAPD foi baseada em 37 bandas polim?rficas e a an?lise filogen?tica revelou uma diversidade gen?tica em 50% com forma??o de quatro grupos e tr?s variedades isoladas. Os grupos formados pelas variedades de nome Lageado e Zebu branco parecem ter sido pela forma dos gr?os e raz?o C/L.

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2016-10-06T18:31:14Z No. of bitstreams: 1 2011 - Ana Maria Silva de Araujo.pdf: 2356633 bytes, checksum: ddb45ffd88bc508180544f6f9a4cb0a3 (MD5) / Made available in DSpace on 2016-10-06T18:31:14Z (GMT). No. of bitstreams: 1 2011 - Ana Maria Silva de Araujo.pdf: 2356633 bytes, checksum: ddb45ffd88bc508180544f6f9a4cb0a3 (MD5) Previous issue date: 2011-02-24 / CAPES / CNPq / The wet tropical climate, characteristic of great part of the Northeast, Midwest and part of the Southeast regions of Brazil, present markedly a rainy season and a dry one. During the dry season, the evapotranspiration provides capillary movements of water in soil coincidently with the superficial accumulation of NO3 -. The amount of nitrate in the soil may vary with the seasonality of environmental variables, such as the temperature and precipitation, thus influencing the assimilation process, the consumption and the storage of that ion by the plants. This way, in the beginning of the rainy period there is a great availability of NO3 - in the soil. This phenomenon has being identified as nitrate flush. The objective of the study was to evaluate the possibility of occurrence of synchronism among N-NO3 - flush and absorption of N by two rice varieties dissimilar in the storage capacity and remobilization of N in field conditions. Two experiments were installed in two consecutive years in the town of S?o Luis and in Miranda do Norte, Maranh?o State. The areas had three different management systems: alley cropping, slash-and-burn agriculture (cutting down and burning), and conventional system. The legume trees used were: Leucaena leucocephala (Leucena); Clitoria fairchildiana (Philippine pigeonwings); and Acacia mangium (acacia). They were combined among themselves, in the following treatments: Philippine pigeonwings + Leucena (S + L); Acacia + Leucena (A + L), and a reference plot, without legume trees. The experimental design was of random blocks in sub-subdivided plots with four repetitions. The appraised parameters were: nitrate reductase (NR) activity, the plant N metabolism, the mineralization of N in soil, the seasonal flow of NO3 - in soil, biomass production, and the rice productivity. According to the results, the addition of biomass from legume trees did not cause great alterations in the soil characteristics, in S?o Luis and in the Miranda do Norte areas. In the soil the largest changes were observed for the burnt area and the one with conventional system. The Acacia + Leucena alley cropping influenced significantly most of evaluated variables, and in most of the time they showed superior to Sombreiro + Leucena alley and the testimony. In general, the activity of the nitrate reductase was low, for all systems. However, a variation was verified in the enzyme activity according to sampling period. The results showed the largest reductions in NO3 - in the hems, indicating this is the preferential plant part for N remobilization in rice. The traditional variety always presented lower values of NR activity, and it accumulated more NO3 - compared with the improved variety. There were seasonal variations in the levels of NO3 - and NH4 + in the soil; however the largest accumulations of NH4 + occurred in the superficial layer and in the beginning of the rainy season. The rice productivity was low; however it differed significantly among the management systems. / O clima tropical ?mido, caracter?stico de grande parte do Nordeste, Centro-Oeste e parte do Sudeste do Brasil, apresenta de forma marcante uma esta??o chuvosa e outra seca. Durante a esta??o seca, a evapotranspira??o proporciona movimentos capilares de ?gua no solo coincidentes com o ac?mulo superficial de NO3 -. Esse conte?do de nitrato no solo pode variar com a sazonalidade de vari?veis ambientais, tais como a temperatura e a precipita??o, assim influenciando o processo de assimila??o, o consumo e o armazenamento desse ?on pelas plantas. Portanto, no in?cio do per?odo chuvoso ocorre grande disponibilidade de NO3 - no solo e este fen?meno tem sido denominado como ?flush? de nitrato. O objetivo do estudo foi o de avaliar a possibilidade de ocorr?ncia do sincronismo entre esse ?flush? de N-NO3 - e a absor??o de N por duas variedades de arroz diferentes quanto ? capacidade de armazenamento e remobiliza??o de N em condi??es de campo. Para tal, foram instalados dois experimentos por dois anos consecutivos nos munic?pios de S?o Luis e Miranda do Norte, Estado do Maranh?o em tr?s diferentes sistemas de manejo: cultivo em al?ias, ro?a no toco (derrubada e queima) e sistema convencional. As esp?cies de leguminosas utilizadas foram: Leucaena leucocephala (leucena); a Clitoria fairchildiana (sombreiro) e a Acacia mangium (ac?cia), combinadas entre si, nos seguintes tratamentos: Sombreiro + Leucena (S + L); Ac?cia + Leucena (A+ L) e Testemunha, sem leguminosas. Em todos os sistemas de manejo adotou-se o delineamento experimental de blocos casualizados em parcelas sub-subdivididas com quatro repeti??es. Os par?metros avaliados foram ? atividade da nitrato redutase, o metabolismo do N na planta, o fluxo sazonal de NO3 - no solo, produ??o de biomassa e a produtividade do arroz. De acordo com resultados, a adi??o de biomassa das leguminosas n?o causou grandes altera??es nas caracter?sticas do solo tanto em S?o Luis quanto no munic?pio de Miranda do Norte. No solo as maiores altera??es foram observadas para o a ?rea queimada e a ?rea mantida em sistema convencional. As al?ias de Ac?cia + Leucena influenciaram de forma significativa a maioria das vari?veis avaliadas apresentando-se na maioria das vezes superiores as al?ias de Sombreiro + Leucena e a testemunha. No geral, a atividade da nitrato redutase foi baixa em todos os sistemas de manejo. No entanto, constatou-se varia??o na atividade da enzima em fun??o ?poca de amostragem. Os resultados mostraram que as maiores redu??es nos teores de NO3 - foram observados nas bainhas, indicando ser este o local preferencial para a remobiliza??o de N em arroz. A variedade tradicional apresentou sempre valores mais baixos de atividade da NR e acumulou mais NO3 - comparada com a variedade melhorada. Houve varia??es sazonais no teor de NO3 - e NH4 + no solo, por?m os maiores ac?mulos de NH4 + ocorreram na camada superficial e in?cio da esta??o chuvosa. A produtividade do arroz foi baixa, por?m diferiu de forma significativa entre os sistemas de manejo.

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2016-10-19T19:18:40Z No. of bitstreams: 1 2015 - Jo?o Ant?nio Montibeller Furtado e Silva.pdf: 2711514 bytes, checksum: effd09162dc88c6c073a5293a03578ff (MD5) / Made available in DSpace on 2016-10-19T19:18:40Z (GMT). No. of bitstreams: 1 2015 - Jo?o Ant?nio Montibeller Furtado e Silva.pdf: 2711514 bytes, checksum: effd09162dc88c6c073a5293a03578ff (MD5) Previous issue date: 2015-08-26 / CAPES / FAPERJ / In the zones that produce swine, the farms have a high concentration of animals that generate large amounts of slurry, which becomes a problem due to lack of agricultural area for distribution, at the rates calculated to be used as a supply of nutrients to crops. Systematic application of pig slurry (PS) can increase the levels of heavy metals (HMs) in the soil. The HMs dynamics in the soil depends on their chemical form, the slurry characteristics, plant absorption capacity and the phytomass management. The purpose of this study was to study the effect of applying PS fertilizing and intensity of nutrient removal, represented by managements of biomass, in the dynamics of soil HMs. The levels of heavy metals (Cu, Zn, Mn, Ni and Pb) were evaluated in a area with Typic Hapludox soil, after three applications of PS. The Humic Acid (HA) obtained from PS samples was characterized in terms of elemental composition, nuclear magnetic resonance of carbon-13 and infrared spectroscopy, in order to evaluate their potential to interact with the HMs. The total contents of Cu, Zn, Mn, Ni and Pb was determined in feed samples, PS from slurry tanks on a finishing swine farm and plants fertilized with PS, consisting a consortium of lopsided oat (Avena strigose, Schreb.) and Italian rye grass (Lolium multiflorum Lam.). The dynamics of HMs in soil was assessed by determining the pseudototals levels in six layers (0-2.5; 2.5-5; 5-10; 10-20; 20-40; 40-80 cm), and bioavailable in the layer of most exploration of consortium roots studied (0-20 cm). The metals Cu, Zn, Mn, Ni e Pb were found in the feed, indicating the source and origin of the HMs in the PS. With 55% of aliphatic chains, 14% of oxygenated aliphatics and 15% of carboxyl, the characterization of HA in the PS showed a high capacity to interact and form soluble complexes with HMs. All analysed HMs had pseudototals levels that increased in all six layers of soil, as a function of the PS dose applied, and the bioavailable forms in the arable layer (0-20 cm). The management with higher intensity of biomass removal, the soil showed the lowest levels of HMs, pseudototal and bioavailables. The total metal accumulation in plants showed a positive and significant correlation with the levels of bioavailables in the soil, suggesting that the HMs were in exchangeable and/or hydrosoluble forms, capable of being transferred to water bodies and to enter the food chain. / Nas regi?es produtoras de su?nos, as granjas apresentam elevadas concentra??es de animais que geram grandes quantidades de res?duos, tornando-se um problema devido ? falta de ?rea agr?cola para sua distribui??o, em taxas calculadas para o fornecimento de nutrientes para as culturas.Aplica??es sistem?ticas de dejeto l?quido de su?nos (DLS) podem elevar os teores de metais pesados (MPs) no solo. A din?mica dos MPs depende da forma qu?mica que se encontram no solo, das caracter?sticas do res?duo aplicado, da absor??o pelas plantas e do manejo da fitomassa. Com o objetivo de estudar os efeitos da aplica??o de dejeto l?quido de su?nos e da intensidade de remo??o de nutrientes, representadas por manejos de fitomassa, na din?mica de MPs do solo, o presente trabalho avaliou os teores de metais pesados (Cu, Zn, Mn, Ni e Pb) em uma ?rea de Nitossolo Vermelho Distr?fico, ap?s tr?s aplica??es de DLS.Os ?cidos h?micos (AH) obtidos de amostras de DLS foram caracterizados quanto ? composi??o elementar,resson?ncia magn?tica nuclear do carbono-13 e espectroscopia de infravermelho, a fim de se avaliar o seu potencial de intera??o com os MPs. Foram determinados os teores totais de Cu, Zn, Mn, Ni ePb em amostras de ra??o, DLS oriundo de esterqueiras, e em tecido do cons?rcio de plantas de aveia preta (Avena strigosa Schreb.) e azev?m (Lolium multiflorum Lam.) adubadas com DLS. A din?mica dos MPs no solo foi avaliada atrav?s da determina??o dos teores pseudototais em seis camadas do solo (0-2,5; 2,5-5; 5-10; 10-20; 20-40, e 40-80 cm), e biodispon?veis na camada de maior explora??o das ra?zes do cons?rcio estudado (0-20 cm).Os metais Cu, Zn, Mn, Ni e Pb foram encontrados na ra??o, indicando a origem desses MPs no DLS. A caracteriza??o dos AH do DLS, com 55% de cadeias alif?ticas, 14% alif?ticas oxigenadas e 15% de carboxilas, demonstra a sua alta capacidade de intera??o e forma??o de complexos sol?veis com MPs. Todos os metais avaliados apresentaram ac?mulo nas seis camadas do solo em fun??o da dose de DLS aplicada, inclusive em formas biodispon?veis na camada ar?vel (0-20 cm). No manejo com maior intensidade de remo??o de fitomassa, o solo apresentou os menores teores de MPs, tanto pseudototais, como biodispon?veis. O ac?mulo total desses metais nas plantas apresentou correla??o positiva e significativa com os teores biodispon?veis do solo, indicando que os MPs se encontravam em formas troc?veis e/ou hidrossol?veis, com capacidade para serem transferidos para corpos h?dricos e entrar na cadeia tr?fica.

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2016-10-21T17:28:48Z No. of bitstreams: 1 2016 - Alessandro Samuel-Rosa.pdf: 15092171 bytes, checksum: bbe06c922805d4196e0a50c4f2aee7a5 (MD5) / Made available in DSpace on 2016-10-21T17:28:48Z (GMT). No. of bitstreams: 1 2016 - Alessandro Samuel-Rosa.pdf: 15092171 bytes, checksum: bbe06c922805d4196e0a50c4f2aee7a5 (MD5) Previous issue date: 2016-02-24 / CNPq / Modern soil spatial modelling is based on statistical models to explore the empirical relation-ship among environmental conditions and soil properties. These models are a simplification of reality, and their outcome (soil map) will always be in error. What a soil map conveys is what we expect the soil to be, acknowledging that we are uncertain about it. The objective of this thesis is to evaluate important sources of uncertainty in spatial soil modelling, with emphasis on soil and covariate data. Case studies were developed using data from a catchment located in Southern Brazil. The soil spatial distribution in the study area is highly variable, being deter-mined by the geology and geomorphology (coarse spatial scales), and by agricultural practices (fine spatial scales). Four topsoil properties were explored: clay content, organic carbon con-tent, effective cation exchange capacity and bulk density. Five covariates, each with two levels of spatial detail, were used: area-class soil maps, digital elevation models, geologic maps, land use maps, and satellite images. These soil and covariate data constitute the Santa Maria dataset. Two packages for R were created in support to the case studies, the first (pedometrics) con-taining various functions for spatial exploratory data analysis and model calibration, the second (spsann) designed for the optimization of spatial samples using simulated annealing. The case studies illustrated that existing covariates are suitable for calibrating soil spatial models, and that using more detailed covariates results in only a modest increase in the prediction ac-curacy that may not outweigh the extra costs. More efficient means of increasing prediction accuracy should be explored, such as obtaining more soil observations. For this end, one should use objective means for selecting observation locations to minimize the effects of psycholog-ical responses of soil modellers to conceptual and operational factors on the sampling design. This because conceptual and operational difficulties encountered in the field determine how the motivation of soil modellers shifts between learning/verifying soil-landscape relationships and maximizing the number of observations and geographic coverage. For the sole purpose of spa-tial trend estimation, it should suffice to optimize spatial samples aiming only at reproducing the marginal distribution of the covariates. For the joint purpose of optimizing sample configu-rations for spatial trend and variogram estimation, and spatial interpolation, one can formulate a sound multi-objective optimization problem using robust versions of existing sampling algo-rithms. Overall, we have learned that a single, universal recipe for reducing our uncertainty in soil spatial modelling cannot be formulated. Deciding upon efficient ways of reducing our uncertainty requires, first, that we explore the full potential of existing soil and covariate data using sound spatial modelling techniques. / A modelagem espacial do solo moderna usa modelos estat?sticos para explorar a rela??o em-p?rica entre as condi??es ambientais e as propriedades do solo. Esses modelos s?o uma sim-plifica??o da realidade, e seu resultado (mapa do solo) estar? sempre errado. O que um mapa do solo transmite ? o que esperamos que o solo seja, reconhecendo que somos incertos sobre ele. O objetivo dessa tese ? avaliar importantes fontes de incerteza na modelagem espacial do solo, com ?nfase nos dados do solo e covari?veis. Estudos de caso foram desenvolvidos usando dados de uma bacia hidrogr?fica do sul do Brasil. A distribui??o espacial do solo na ?rea de estudo ? vari?vel, sendo determinada pela geologia e geomorfologia (escalas espaciais maiores) e pr?ticas agr?colas (escalas espaciais menores). Quatro propriedades do solo foram explora-das: teor de argila, teor de carbono org?nico, capacidade de troca cati?nica efetiva e densidade. Cinco covari?veis, cada um com dois n?veis de detalhe espacial, foram utilizadas: mapas areais de classes de solo, modelos digitais de eleva??o, mapas geol?gicos, mapas de uso da terra, e imagens de sat?lite. Esses dados constituem o conjunto de dados de Santa Maria. Dois paco-tes para R foram criados, o primeiro (pedometrics) contendo v?rias fun??es para a an?lise explorat?ria espacial de dados e calibra??o de modelos, o segundo (spann) projetado para a optimiza??o de amostras espaciais usando recozimento simulado. Os estudos de caso ilustraram que as covari?veis existentes s?o apropriadas para calibrar modelos espaciais do solo, e que o uso de covari?veis mais detalhadas resulta em modesto aumento na acur?cia de predi??o que pode n?o compensar os custos adicionais. Meios mais eficientes de aumentar a acur?cia de pre-di??o devem ser explorados, como obter mais observa??es do solo. Para esse fim, deve-se usar meios objetivos para a sele??o dos locais de observa??o a fim de minimizar os efeitos das res-postas psicol?gicas dos modeladores do solo a fatores conceituais e operacionais sobre o plano de amostragem. Isso porque as dificuldades conceituais e operacionais encontradas no campo determinam mudan?as na motiva??o dos modeladores do solo entre aprendizagem/verifica??o das rela??es solo-paisagem e maximiza??o do n?mero de observa??es e cobertura geogr?fica. Para estimar a tend?ncia espacial, deve ser suficiente otimizar as amostras espaciais visando so-mente reproduzir a distribui??o marginal das covari?veis. Para otimizar configura??es amostrais para estimar a tend?ncia espacial e o variograma, e interpola??o espacial, pode-se formular um problema de otimiza??o multi-objetivo s?lido usando vers?es robustas de algoritmos de amos-tragem existentes. No geral, aprendemos que uma receita ?nica, universal para a redu??o da incerteza na modelagem espacial do solo n?o pode ser formulada. Decidir sobre formas efi-cazes de redu??o da incerteza requer, em primeiro lugar, que exploremos todo o potencial dos dados existentes usando t?cnicas de modelagem espacial s?lidas.

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-02-07T18:57:15Z No. of bitstreams: 1 2016 - Shirlei Almeida Assun??o.pdf: 1407109 bytes, checksum: 346922df83ba0b7c92b59002d73737df (MD5) / Made available in DSpace on 2017-02-07T18:57:15Z (GMT). No. of bitstreams: 1 2016 - Shirlei Almeida Assun??o.pdf: 1407109 bytes, checksum: 346922df83ba0b7c92b59002d73737df (MD5) Previous issue date: 2016-02-22 / CAPES / Faperj / Brazil is the biggest sugarcane producer of the world with cultivated area superior to nine millions hectares. To reach economically viable productivity levels it is necessary to make use of high amounts of N fertilizers. These fertilizers are high cost and they also can contribute to emission of greenhouse gases and pollution of watercourses, as well as, to influence directly on the decomposition of the soil organic matter (SOM). In this context to understand how interactions between nitrogen and SOM occurs in sugarcane fields is important from both economic and environmental points of view. Therefore, the objective of this study was to evaluate quantity and quality of soil carbon when different doses of nitrogen are added in the form of ammonium sulphate in a sugarcane raw agro-ecosystem in an ultisol from Coastal Plains. The experiment was conduced in sugarcane fields renovated in 2009 in area of the company LASA alcohol distillery, in Linhares - ES, in an Ultisol with sandy to medium texture, from Coastal Plain environment. The variety of sugarcane (Saccharum spp.) used was RB918639. There were evaluated five treatments of N ammonium sulphate doses: 0 (control), 80, 100, 120 and 160 kg of N per ha-1 with four repetitions, established under experimental design of randomized blocks. Each experimental unit (plot) was 70 m? (5 lines with 10 m, spaced by 1.4 m between lines). Samples of plant and soil were collected in September 2013 and 2014, corresponding to 4th and 5th harvest. The results indicated that among the N doses evaluated, the doses of 100 and 120 kg were the most efficient on accumulating carbon on the humic fractions, particle size, densimetric and oxidizable carbon fractions. The dose of 160 kg was the less effective to carbon accumulation on the humic fractions, particle size, densimetric and oxidizable carbon fractions. Total nitrogen, natural abundance of 13C and 15N, stem and straw production were not influenced by N rates, with no differences on any of the seasons. About the elemental composition of humic acids (HA), the quantities of chemicals were very similar between doses and coherent with results in the literature for the HA. In the E4/E6 ratio, the dose of 160 kg of N was the one with the lowest E4/E6 ratio. Regarding the infrared with Fourier transformation it was observed the predominance of aliphatic groups, and the analysis of major components enabled the clear separation of the effects from different N doses. In the 13CNMR prevailed larger amounts of aliphatic carbons, it was confirmed with the aliphaticity index of the samples, the results were above 80% for all samples. It was also verified through the 13 CNMR that the control area and the dose of 160 kg had the lowest aromaticity rates. Therefore, it was concluded that different fractionations of organic matter along with spectroscopic techniques were effective on evaluating the influence of different nitrogen doses to the decomposition of SOM. / O Brasil ? o maior produtor mundial de cana-de-a??car, com ?rea plantada que ultrapassa os nove milhoes de hectares. Para obter produtividade economicamente vi?vel da cultura, s?o utilizadas elevadas doses de fertilizantes nitrogenados. Tais fertilizantes possuem elevados custos economicos, podem contribuir para emiss?o de gases do efeito estufa e para polui??o de cursos de ?gua, al?m de infuenciarem de forma direta na decomposi??o da mat?ria org?nica do solo (MOS). Neste contexto, entender como ocorre a intera??o entre o nitrog?nio e a MOS no cultivo da cana ? importante tanto do vista economico quanto ambiental. Assim sendo o objetivo desse estudo foi avaliar a quantidade e qualidade do carbono do solo em fun??o de diferentes doses de nitrog?nio adicionado na forma de sulfato de am?nio no agroecossistema cana-de-a??car crua em Argissolo Amarelo de Tabuleiro Costeiro. O experimento foi instalado em canavial renovado em 2009, em ?rea cedida pela Usina LASA, no munic?pio de Linhares ? ES, em Argissolo Amarelo de textura arenosa/m?dia, no ambiente de Tabuleiros Costeiros. A variedade da cana-de-a??car (Saccharum spp.) utilizada foi a RB918639. Foram avaliados cinco tratamentos/doses de N-sulfato de am?nio quais sejam: 0 (testemunha), 80, 100, 120 e 160 kg ha-1 de N com quatro repeti??es, estabelecidos segundo delineamento experimental de blocos ao acaso. Cada unidade experimental (parcela) tinha 70 m? (5 linhas com 10 m, espa?adas 1,4 m). As amostras de planta e terra foram coletadas no m?s de setembro de 2014, correspondendo ? 4? soca. Os resultados indicaram que as doses de 100 e 120 kg, foram as mais eficientes para acumular o carbono nas fra??es h?micas, granulom?tricas, densim?tricas e nas fra??es do carbono oxid?vel. A dose de 160 kg foi a menos eficiente para acumular o carbono nas fra??es h?micas, granulom?tricas, densim?tricas e nas fra??es do carbono oxid?vel. O nitrog?nio total, a abund?ncia natural de 13C e 15N e a produtividade de colmo e palhada n?o apresentaram diferen?as significativas. Na composi??o elementar dos ?cidos h?micos (AH), as quantidades dos elementos qu?micos foram bem semelhantes entre as doses e coerentes com resultados na literatura para os AH. Para o coeficiente E4/E6 a dose de 160 kg de N foi a que apresentou o menor coeficiente E4/E6. Em rela??o ao infravermelho com transforma??o de Fourier verificou-se o predom?nio de grupamentos alif?ticos, e a analise de componentes principais possibilitou a separa??o clara do efeito das diferentes doses de N. No RMN C prevaleceram maiores quantidades de carbonos alif?ticos, isto foi confirmado com o ?ndice de alif?ticidade das amostras que foram superiores a 80 % para todas as amostras. Verificou-se tamb?m atrav?s do RMN 13C que a testemunha e a dose de 160 kg foram as que apresentaram menores ?ndices de aromaticidade. Portanto, conclui-se que os diferentes fracionamentos bem com as t?cnicas espectrosc?picas foram eficientes para avaliar a influencia das diferentes doses de N na decomposi??o da MOS.

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-04-18T20:10:31Z No. of bitstreams: 1 2010 - Cec?lia de Souza Ant?nio.pdf: 1613209 bytes, checksum: e560fdd88ef8707b79c6d4b0120730ec (MD5) / Made available in DSpace on 2017-04-18T20:10:31Z (GMT). No. of bitstreams: 1 2010 - Cec?lia de Souza Ant?nio.pdf: 1613209 bytes, checksum: e560fdd88ef8707b79c6d4b0120730ec (MD5) Previous issue date: 2010-04-20 / CAPES / The sugar cane is one of the major agricultural products in Brazil. The crop is able to associate with diazotrophic bacteria (fix nitrogen from the air), that may be located inside the plant tissue (entophytic). The diazotrophic bacteria are capable of promoting growth of sugar cane by means of biological nitrogen fixation (BNF) or production of hormones. But little is known about populations of these bacteria present in sugar cane. This work aimed to study diversity of the population and identify the isolates by molecular and physiological methods, as well as to assess the effectiveness of some isolates to promote plant growth of sugar cane in the field. In solid potato media, there were observed the formation of seven groups, with 95% of similarity, showing the great colonies morphology variation. Many isolates showed similar characteristics to the genus Gluconacetobacter, when analyzed in semi-solid LGI-P media and solid Potato-P and LGI-P media. Two isolates were most efficient in the endolar synthesis with production over 49 ?g/mL. All isolates were classified as Gram negative. Of the 36 isolates, 27.5% were similar to the standard strain RB 11366 (Burkholderia tropica), 45% to BR 11281 strain (Gluconacetobacter diazotrophicus) and 5% to the other patterns BR 11335 (Herbaspirillum seropedicae), BR 11504 (Herbaspirillum rubrisubalbicans) and BR 11145 (Azospirillum amazonense). Through the comparison of the sequencing of 16S rDNA with the NCBI GenBank isolate 215 was identified as belonging to species Gluconacetobacter diazotrophicus, the 179-1a belonging to Burkholderia tropica and the isolated 151-B, 211-A, and 219 to the gender Burkholderia. The inoculated strains 160-1 and 215 promoted an increase in the straw dry biomass (up to 0.7 Mg ha-1) and total nitrogen of flag leaf (above 69,7 kg ha-1), respectively in the tested varieties RB 72454 and RB 918,639. Only the 160-1 isolate was able to promote increase in biomass in the RB 867515 variety. Stalk yield was higher for the variety RB 918639 with 191.96 Mg ha-1. / A cana-de-a??car ? um dos principais produtos agr?colas do Brasil. A cultura ? capaz de se associar as bact?rias diazotr?ficas (fixam nitrog?nio do ar), que podem estar no interior do tecido da planta (endof?ticas). As bact?rias diazotr?ficas endof?ticas s?o capazes de promover o crescimento da cana-de-a??car por meio da fixa??o biol?gica do nitrog?nio (FBN) ou pela produ??o de fitorm?nios. Mas pouco se conhece sobre as popula??es presentes destas bact?rias em cana-de-a??car. O presente trabalho visou estudar a diversidade da popula??o e identificar estes isolados, atrav?s de m?todos moleculares e fisiol?gicos, assim como avaliar a efici?ncia de alguns isolados na promo??o de crescimento vegetal de plantas de cana-de-a??car no campo. Foi observada em meio s?lido Batata, com 95% de similaridade, a forma??o de sete grupos mostrando a grande varia??o morfol?gica de col?nias neste meio testado. Muitos isolados apresentaram caracter?sticas similares ao g?nero Gluconacetobacter, quando analisados em meio semi-s?lido LGI-P e s?lido Batata-P e LGI-P. Dois isolados foram mais eficientes na s?ntese de ind?les com produ??es acima de 49 ?g/mL. Todos os isolados foram classificados como Gram negativos. Dos 36 isolados avaliados, 27,5% foram semelhantes ? estirpe padr?o RB 11366 (Burkholderia tropica); 45% a BR 11281 (Gluconacetobacter diazotrophicus) e 5% aos demais padr?es BR 11335 (Herbaspirillum seropedicae), BR 11504 (Herbaspirillum rubrisubalbicans) e BR 11145 (Azospirillum amazonense). Atrav?s da compara??o do seq?enciamento do gene 16S rDNA com o NCBI GenBank o isolado 215 foi identificado com pertencente a esp?cie de Gluconacetobacter diazotrophicus , o 179-1A com pertencente a esp?cie Burkholderia tropica e os isolados 151-B, 211-A e 219 ao g?nero Burkholderia. As estirpes 160-1 e 215 inoculadas promoveram aumento na produ??o de biomassa seca da palha (acima de 0,7 Mg.ha-1) e nitrog?nio total da folha bandeira (acima de 69,7 kg.ha-1), respectivamente nas variedades RB 72454 e RB 918639 testadas. Apenas o isolado 160-1 foi capaz de promover um aumento de biomassa seca na variedade RB 867515. A produ??o de colmos foi maior para a variedade RB918639 com 191,96 Mg.ha-1.

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-05-05T18:01:27Z No. of bitstreams: 1 2013 - Silvio da Silva Santos.pdf: 1585710 bytes, checksum: 55512544fcf22f1d09c9080258d4c607 (MD5) / Made available in DSpace on 2017-05-05T18:01:27Z (GMT). No. of bitstreams: 1 2013 - Silvio da Silva Santos.pdf: 1585710 bytes, checksum: 55512544fcf22f1d09c9080258d4c607 (MD5) Previous issue date: 2013-04-30 / CAPES / There is a growing demand for organic fertilizers in Brazil, mainly for growing vegetables. Composting is a technique that can be used as an alternative to increase the availability and quality of organic fertilizers. During the composting process, there is emission gases such as carbon dioxide (CO2), nitrous oxide (N2O) and methane (CH4), which contribute to the greenhouse effect in the planet, also of ammonia (NH3), which reduces the efficiency of the composting process. Emissions of N2O and NH3 to the atmosphere has been attributed in part to the decomposition of organic matter from crop residues that are used in soil management systems. Thus, Chapter I aimed to characterize mixtures of elephant grass (Pennisetum purpureum) with different materials in order to produce an organic fertilizer rich in nutrients and can be used in the cultivation of sugar beets. The treatments were: (i) elephant grass + cattle manure;(ii) elephant grass + gliricidia; and (iii) elephant grass + castor cake. The evaluations were performed for 120 days. In this study, the compound formulated with a mixture of elephant grass and gliricidia resulted in higher concentrations of N, which shows the high potential of the material to be used as organic fertilizer for crops with high nutritional requirements. The N losses by volatilization were not relevant in the composting process. In the Chapter II it was evaluated the emissions of N2O and NH3 in the compost and other organic N sources used in the production of beet and lettuce. The treatments consisted of: (i) organic compound, prepared from the mixture of elephant grass with gliricidia (Gliricidia sepium) + fertilization coverage with castor bean; (ii) green manure dwarf mucuna (Mucuna deeringiana) + fertilization coverage with castor bean; (iii) cattle manure + fertilizer topdressing with chicken manure tanned; (iv) urea in planting and coverage; and (v) the control treatment (without nitrogen). Considering these results, the N2O emissions from the soil ranged from 7.37 and 2699.62 ?g N2O-N-1. The volatilization losses of ammonia ranged from 9.5 to 30% of the N applied. The application of cattle manure + chicken manure management proved to be environmentally more suitable for growing vegetables, since it resulted in lowest flow of nitrous oxide from the soil and ammonia volatilization. Moreover, urea is the N source that causes most losses by volatilization of ammonia, with zero residual effect for the next crop, in this case for the production of lettuce. The highest emissions were observed after rainfall, regardless of treatment, highlighting the importance of presence of water in the environment for the emissions of N2O to occur. / ? crescente a demanda por adubos org?nicos no Brasil, principalmente para o cultivo de hortali?as. A compostagem ? uma t?cnica que pode ser utilizada como alternativa para aumentar a disponibilidade e a qualidade dos fertilizantes org?nicos. Durante o processo de compostagem, h? emiss?o de gases, como g?s carb?nico (CO2), ?xido nitroso (N2O) e metano (CH4), que contribuem para o efeito estufa no planeta, al?m de am?nia (NH3), que reduz a efici?ncia do processo de compostagem. As emiss?es de N2O e NH3 para atmosfera tem sido atribu?das, em parte, ? decomposi??o da mat?ria org?nica proveniente dos res?duos vegetais que s?o empregados nos sistemas de manejo do solo. Dessa maneira, o Cap?tulo I teve como objetivo caracterizar misturas de capim-elefante (Pennisetum purpureum) com diferentes mat?rias-primas, visando produzir um adubo org?nico rico em nutrientes e capaz de ser usado no cultivo de hortali?as. Os tratamentos foram os seguintes: (i) capim-elefante + esterco bovino curtido; (ii) capim-elefante + gliricidia (Gliricidia sepium); e (iii) capim-elefante + torta de mamona. As avalia??es foram realizadas durante 120 dias. Neste estudo, o composto formulado com a mistura de capim-elefante e gliricidia resultou em maior teor de N, o que mostra o elevado potencial do material para ser usado como adubo org?nico em culturas com elevada exig?ncia nutricional. As perdas de N por volatiliza??o de am?nia n?o foram relevantes at? 34 dias de compostagem. O Cap?tulo II teve como objetivo avaliar as emiss?es de N2O e NH3 em composto org?nico e outras fontes de N usadas na produ??o de hortali?as. Os tratamentos consistiram da aplica??o de: (i) composto org?nico, preparado da mistura de capim elefante com gliricidia (Gliricidia sepium) + fertiliza??o em cobertura com torta de mamona; (ii) aduba??o verde com mucuna an? (Mucuna deeringiana) + fertiliza??o em cobertura com torta de mamona; (iii) esterco bovino curtido + fertiliza??o em cobertura com esterco de ave curtido; (iv) ureia em plantio e cobertura; e (v) tratamento controle (sem aplica??o de N). Considerando os resultados obtidos neste estudo, as emiss?es de N2O do solo variaram de 7,37 e 2699,62 ?g N-N2O m2h-1. As perdas por volatiliza??o de am?nia variaram de 9,5 e 30% do N aplicado. A aplica??o de esterco bovino curtido + esterco de ave curtido mostra ser um manejo ambientalmente mais adequado para o cultivo de hortali?as, por resultar em menores fluxos de ?xido nitroso do solo e volatiliza??o de am?nia. Por outro lado, a ureia ? a fonte de N que provoca as maiores perdas de N por volatiliza??o de am?nia com efeito residual nulo para a cultura seguinte, neste caso para produ??o de alface. As maiores emiss?es foram observadas ap?s precipita??es, independente do tratamento, destacando a necessidade da presen?a de ?gua no ambiente para que ocorram as emiss?es de N2O.

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-05-10T19:19:55Z No. of bitstreams: 1 2012 - Felipe Reis Rodrigues.pdf: 1576034 bytes, checksum: f91efa30a06e540cab9e32f343fe64b0 (MD5) / Made available in DSpace on 2017-05-10T19:19:55Z (GMT). No. of bitstreams: 1 2012 - Felipe Reis Rodrigues.pdf: 1576034 bytes, checksum: f91efa30a06e540cab9e32f343fe64b0 (MD5) Previous issue date: 2012-07-20 / CAPES / In Brazil on December 23, 2003 the National Agency of Sanitary Surveillance - ANVISA has published the resolution number 360 (360 RDC). The purpose of this resolution was to repeal the laws related to nutrition labeling of packaged foods ready for consumption (DRC 39 and 40). The legislation of 2003 had the requirement on the labeling of food content of trans fatty acids, as well as specific characteristics of the information contained therein. Currently, epidemiological studies have be associated the consumption of trans fats to the risk of developing cardiovascular and chronic degenerative diseases. In addition, health professionals report that the children have shown high rates of obesity, a situation directly related to excessive consumption of manufactured products. In order to ensure the maintenance and promotion of health, the accuracy of food labels sold in Brazil, mainly in relation to lipid content present in them should be more effectively monitor. This work aimed to make a critical analysis of the nutritional labeling of ?minibolos? sold in the city of Rio de Janeiro, relating lipid profile and content of trans fatty acids and their claim presented. The methodology used for derivatization of fatty acids is characterized by the extraction transesterification. It consists of an acidic or basic catalysis, where there is a double exchange of glycerides of esters of fatty acids. The method described by Huang (2006) for methylation of fatty acids was subjected to the validation process to ensure the accuracy of the results. The determination and quantification of fatty acids were performed by gas chromatography (GC-FID) using fused silica capillary column CP-Sil 88 (100 mx 0.25 mm), at the Analytical Laboratory of Food and Beverage - LAAB. We analyzed the products containing the information to be free of trans fatty acids to quantify the actual levels of these products in order to ascertain whether the labels were described in reliable information. From the results, the obligation to inform in the labels quantities of trans fatty acids was sufficient to make available to brazilian consumers which foods are free of trans fatty acids and which still have trans fatty acids in the food industry. There were no trans fatty acids in the composition of the samples, what means that is a real assertion to be exempt from the same type of fatty acid. / No Brasil no dia 23 de dezembro de 2003 a Agencia Nacional de Vigil?ncia Sanit?ria ? ANVISA publicou a resolu??o de n?mero 360 (RDC 360). O objetivo desta resolu??o era revogar as legisla??es relacionadas a rotulagem nutricional de alimentos embalados prontos para consumo (RDC 39 e 40). A legisla??o de 2003 teve como principal caracter?stica a exig?ncia de se constar no r?tulo dos alimentos o teor de ?cidos graxos trans, al?m de caracter?sticas especificas das informa??es contidas no mesmo. Atualmente, estudos epidemiol?gicos t?m associado o consumo de gorduras trans ao risco do desenvolvimento de doen?as cardiovasculares e cr?nico-degenerativas. Al?m disso, profissionais da ?rea de sa?de relatam que a popula??o infantil tem apresentado ?ndices elevados de obesidade, situa??o diretamente relacionada ao consumo excessivo de produtos industrializados. Com o intuito de zelar pela manuten??o e promo??o da sa?de da popula??o, deve-se fiscalizar de forma mais efetiva a veracidade dos r?tulos dos alimentos comercializados no Brasil, principalmente em rela??o aos teores lip?dicos presentes nos mesmos. O presente trabalho teve por objetivos fazer uma an?lise cr?tica da rotulagem nutricional de minibolos comercializados em estabelecimentos varejistas na cidade do Rio de Janeiro, relacionando o perfil lip?dico e o teor de ?cidos graxos trans e sua alega??o apresentada. A metodologia empregada para a derivatiza??o dos ?cidos graxos ? caracterizada pela transesterifica??o. Ela consiste em uma cat?lise ?cida ou b?sica, onde h? uma dupla troca de acilglicer?is em ?steres de ?cidos graxos. O m?todo descrito por Huang (2006) para metila??o dos ?cidos graxos foi submetido ao processo de valida??o para assegurar a veracidade dos resultados obtidos. A determina??o e quantifica??o dos ?cidos graxos foram realizadas por cromatografia gasosa (CG-FID), utilizando coluna capilar de s?lica fundida CP-Sil 88 (100 m x 0.25 mm), do Laborat?rio Anal?tico de Alimentos e Bebidas ? LAAB. Foram analisados os produtos que cont?m a informa??o de serem isentos de ?cidos graxos trans para quantificar os teores reais destes produtos, visando averiguar se o descrito nos r?tulos eram informa??es fidedignas. A partir dos resultados, verificou-se em que medida a obrigatoriedade de informar nos r?tulos as quantidades de AG trans foi suficiente para tornar dispon?veis aos consumidores brasileiros quais os alimentos que s?o livres de ?cidos graxos trans e quais ainda possuem ?cidos graxos trans na ind?stria aliment?cia no Brasil. N?o foram encontrados AG trans na composi??o das amostras analisadas, sendo real a alega??o das mesmas serem isentas desse tipo de ?cido graxo.