O objetivo do presente estudo foi investigar se os níveis de estabilização alcançados no final do processo de aquisição e nos canais de desempenho modificam a probabilidade de um dos dois processos envolvidos no aumento de complexidade em aprendizagem motora - modularização e adaptação - ocorrer, quando novos componentes são inseridos na tarefa já aprendida, e sua influência na aprendizagem da tarefa com novos componentes. Cento e cinquenta e três sujeitos de ambos os sexos, entre 10 e 13 anos de idade, realizaram uma tarefa seriada de rastreamento de sinais luminosos. O experimento constou de duas fases: estabilização e adaptação. Três grupos foram formados de acordo com critérios de desempenho a ser alcançados na estabilização: três séries consecutivas de respostas corretas, uma série de respostas antecipatórias e três séries de respostas antecipatórias, numa tarefa seriada composta de cinco estímulos. A fase de adaptação, igual para todos os grupos, ocorreu até o alcance de uma série de respostas antecipatórias numa tarefa com seis estímulos. Os resultados mostraram a ocorrência de ambos os processos: adaptativo e modularização, em 84% e 16% dos sujeitos, respectivamente. Os sujeitos do que alcançaram respostas antecipatórias foram posteriormente divididos em subgrupos com base na estabilidade interindividual da mudança intra-individual nos canais de desempenho ao longo da fase de estabilização. Foram definidos 4 subgrupos: estável no canal superior; estável no canal inferior; com tendência a mudança ascendente; e com oscilação. Os resultados da análise de regressão logística permitiram inferir que o subgrupo estável no canal superior da consistência do desempenho da sequência em respostas antecipatórias tem quatro vezes mais probabilidade de utilizar o processo de modularização do que o subgrupo estável no canal inferior, quando novos componentes são inseridos na tarefa já aprendida. Além disso, foi possível identificar que os sujeitos que utilizaram o processo de modularização necessitaram de uma menor quantidade de tentativas para a aprendizagem da nova tarefa / The purpose of this study was to investigate whether levels of stabilization achieved by the end of the acquisition process and performance channels modify the probability of occurrence of one of the two processes involved in the increase of complexity in motor learning - modularization and adaptation - when new components are inserted into the task already learned, and their influence on the learning of the task with new components. One hundred and fifty-three subjects of both sexes, between 10 and 13 years of age, performed a serial tracking task of luminous stimuli. The experiment consisted of two phases: stabilization and adaptation. Three groups were formed according to performance criteria to be achieved in the stabilization phase: three consecutive series of correct responses (group G_3C), a series of antecipatory responses (G_1A group) and three series of anticipatory responses (group G_3A) in a task with five stimuli. The adaptation phase, the same for all groups, took place until the achievement of a series of anticipatory responses in a task with six stimuli. The results showed the occurrence of both processes: adaptive and modularization, in 84% and 16% of the subjects, respectively. The subjects of G_1A and G_3A were afterwards divided into subgroups based on the interindividual stability of intra-individual change in the performance channels during the stabilization phase. Four groups were established: stable in the upper channel, stable in the lower channel, upward moving tendency, and oscillation groups. Based on the results of binary logistic regression analysis it was observed that the stable upper channel subgroup in consistency of the sequence in anticipatory responses is four times more likely to use the process of modularization in relation to the stable lower channel subgroup, when new components are inserted into the task already learned. It was also possible to identify that the subjects who used the process of modularization needed fewer attempts to learn the new task

Abstract Risk assessment of chemicals needs reliable scientific information and one source of information is the characterization of the metabolic fate and toxicokinetics of a chemical. Metabolism is often the most important factor contributing to toxicokinetics. Cytochrome P450 (CYP) enzymes are a superfamily of microsomal proteins playing a pivotal role in xenobiotic metabolism. In the present study, pesticides were used as representative xenobiotics since exposure to pesticides is a global challenge to risk assessment. Human and animal in vitro hepatic models were applied with the advantage of novel analytical techniques (LC/TOF-MS and LC/MS-MS) to elucidate the in vitro metabolism and interaction of selected pesticides. The results of these studies demonstrate that CYP enzymes catalyze the bioactivation of profenofos, diuron and carbosulfan into their more toxic metabolites desthiopropylprofenofos, N-demethyldiuron and carbofuran, respectively. The suspected carcinogenic metabolite of metalaxyl, 2,6-dimethylaniline, was not detected. CYP3A4 and CYP2C19 activities may be important in determining the toxicity arising from exposure to profenofos and carbosulfan. Individuals with high CYP1A2 and CYP2C19 activities might be more susceptible to diuron toxicity. Qualitative results of in vitro metabolism were generally in agreement with the results obtained from the published in vivo data, at least for the active chemical moiety and major metabolites. Considerable differences in the quantities of the metabolites produced within the species, as well as in the ratios of the metabolites among the species, were observed. These findings illustrate that in vitro screening of qualitative and quantitative differences are needed to provide a firm basis for interspecies and in vitro-in vivo extrapolations. Based on our findings, in vitro-in vivo extrapolation based on the elucidation of the in vitro metabolic pattern of pesticides in human and animal hepatic models could be a good model for understanding and extending the results of pesticides metabolism studies to human health risk assessment.

Ce travail de thèse concerne l’étude de la variabilité inter-individuelle du transcriptome soumis à un stimulus. Cette variabilité n’est pas homogène au sein même du transcriptome et varie suite aux perturbations extérieures.Nous avons mis en place une stratégie d’analyse de la variabilité inter-individuelle sur la base des indices de diversité. Nous avons sélectionné trois jeux de données ayant des caractéristiques particulières (stimulus fort, faible, cinétique, données appariées, …). Ces indices nous permettent de mettre en évidence les différences entre les individus; certains ayant des transcriptomes plus divers que d’autre. Ces différences s’attenues après l’application d’un stimulus au système : La variabilité de la diversité diminue. Nous mesurons cette diminution à l’aide d’une mesure de la similarité. Les résultats indiquent un phénomène global. Nous avons par la suite analysé les données sous le regard d’un indice de spécialisation. Les différences entre groupes témoins et groupes sous l’action d’un stimulus indiquent que la spécialisation diminue de manière significative après l’action du stimulus.Les informations obtenues sont différentes de celles obtenues par les stratégies d’analyses statistiques classiques. Nos travaux montrent enfin que ces outils permettent d’établir de nouvelles hypothèses. Ces indices, utilisés pour la première fois pour ce type d’analyse, ouvrent ainsi la voie à un nouvel arsenal d’outils d’analyse pour la compréhension des modifications transcriptomiques globales mais aussi individuelles et s’inscrit donc parfaitement dans le mouvement de la médecine personnalisée. / This thesis concern the study of the interindividual variability of transcriptome after stimulation. This variability is not homogenous within the same transcriptome and varies with external stimulus.We designed an analysis strategy of the interindividual variability based on diversity indices. We selected three transcriptome datasets based on particular characteristics (strong stimulus, kinetic, paired data…). The indices highlight differences across the samples, some being more diverse than the others. The differences decrease after applying a stimulation to the samples. We measure this modification with a measure of similarity. The results depict a global effect of the stimulation.We analysed the data using specialisation measure. The samples’ specialisation significantly decrease after stimulation, meaning the interindividual variability decreases when the system is on the pressure of a stimulus.Noteworthy, these information are different from those obtained with classical analyses. Our work describe also that this strategy leads to new hyptotheses. These indices are used for these analyses for the first time and can be added to the statistical and mathematical tools already available for transcriptome analysis. They show their capability for highlighting global but also individual modifications and therefore fits perfectly into the field of personalized medicine.

京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第18674号 / 理博第4023号 / 新制||理||1580(附属図書館) / 31607 / 京都大学大学院理学研究科生物科学専攻 / (主査)准教授 中川 尚史, 教授 中務 真人, 教授 高橋 淑子 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM

La variabilité interindividuelle dans la réponse aux médicaments constitue une problématique importante pouvant causer des effets indésirables ou l’échec d’un traitement. Ces variabilités peuvent être causées par une diminution de l’activité de l’enzyme responsable du métabolisme de certains médicaments, fréquemment les cytochromes P450, un système enzymatique majeur dans le métabolisme de ces derniers. Ces enzymes sont sujets à des mutations génétiques appelées polymorphismes, qui altèrent l’activité métabolique. Il est donc important d’évaluer le rôle de ces enzymes dans le métabolisme des médicaments afin d’identifier leur responsabilité dans la variabilité interindividuelle de la réponse au traitement. Parmi l’important système enzymatique que représentent les cytochromes P450, l’isoenzyme CYP2D6 est particulièrement étudiée, ses variations métaboliques revêtant une haute importance clinique. L’un des substrats du CYP2D6 est l’oxycodone, un analgésique narcotique largement prescrit en clinique. Une grande variabilité est observée dans la réponse analgésique à l’oxycodone, variabilité pouvant être causée par un polymorphisme génétique. Il est connu que des variations génétiques dans le CYP2D6 compromettent la réponse analgésique à la codéine en rendant moins importante la formation de son métabolite actif, la morphine. Par analogie, plusieurs études supportent l’hypothèse selon laquelle le métabolite oxymorphone, formée par l’isoenzyme CYP2D6, serait responsable de l’analgésie de l’oxycodone. Une déficience génétique de l’enzyme compromettrait la réponse analgésique au médicament. Les travaux effectués dans le cadre de ce mémoire ont démontré que l’inhibition du CYP2D6 chez des sujets volontaires réduit de moitié la production d’oxymorphone, confirmant l’importante implication de l’enzyme dans le métabolisme de l’oxycodone. Ces résultats démontrent une forte ressemblance avec le métabolisme de la codéine, suggérant que l’oxymorphone pourrait être responsable de l’analgésie. Cependant, les travaux effectués n’ont pu établir de relation entre la concentration plasmatique d’oxymorphone et le niveau d’analgésie ressenti par les sujets. La continuation des études sur le mécanisme d’action de l’oxycodone dans la réponse analgésique est essentielle afin d’établir la source des variabilités interindividuelles expérimentées par les patients et ainsi d’éviter des effets secondaires ou lacunes dans le traitement. / Intersubject variability in drug response is an important issue provoking side effects or treatment failure. Such variability may be caused by the decreased activity of the enzyme metabolising the drug, frequently cytochromes P450, a major enzyme system in drug metabolism. These enzymes are prone to genetic mutations called polymorphisms, which alter their metabolic activity. It is therefore important to assess the role of these enzymes to identify their responsibility in the intersubject variability of the drug. Among the important enzyme system that represents the cytochrome P450, CYP2D6 is particularly studied for its genetic polymorphisms, which are of clinical importance. One of CYP2D6 substrates is oxycodone, a narcotic analgesic widely prescribed in clinical practice. A large variability is observed in the analgesic response to oxycodone, which could be caused by genetic polymorphism. It is known that these variations affect the analgesic response to codeine, which form the active metabolite morphine by CYP2D6 to be effective. Several studies support the hypothesis that oxymorphone, a metabolite formed by CYP2D6, has the analgesia properties, in a similar mechanism to codeine. A genetic deficiency in the enzyme would compromise the analgesic response to the drug. Results obtained from our laboratory indicate that inhibition of CYP2D6 halved oxymorphone production, confirming the significant involvement of the enzyme in the metabolism of oxycodone. These results demonstrate a strong resemblance to codeine metabolism, suggesting that oxymorphone may be responsible for analgesia. We could not find a relationship between plasma concentration of oxymorphone and analgesia level experienced by subjects. Studies on oxycodone mecanism of action in the analgesic response should continue to establish the source of intersubject variability experienced by patients and thus avoid side effects or gaps in treatment.

Red deer males aggregate during the period of antler growth to bachelor groups. Social position - Rank - is unstable in these groups. Previous experiments revealed that rank modulated by agonistic behaviour influence the antler growth and antler cycle timing. Antlers are the secondary sexual characteristics of the deer family and one of the fastest growing tissue in vertebrate taxa. Their development is modulated by androgenic hormone, testosterone. In our experiment, we observed agonistic behaviour of 19 males. They were equipped with GPS collar and observation lasted for two hours in the evening an in the morning, once or twice a week from the end of May to the end of August. Deer were handled regularly for blood samples and downloading the telemetrical data from collars. Base on a statistical analysis we found that in our bachelor group 13 stags kept similar interindividual distances which did not exceed the 22 metres level. These stags - the closest associates - differed in the sum of agonistic interactions. Those who reached 8 or less interactions were called Friends, while subgroup of the others reaching much more interactions were classified as Rivals. We found that number of interactions depended on average distance among males in groups (Friends and Rivals). Rivals with increasing distance...

<p>This investigation focused on the mRNA expression of drug metabolising Cytochromes P-450 (CYP) and UDP-glucuronosyltransferases (UGT) and the transport protein P-glycoprotein (Pgp) in the small intestine of humans and rats.</p><p>The mRNA expression of the investigated genes in the human small intestine (duodenum) varies between individuals giving each one of us personal profile. In general, the most dominant forms are Pgp, CYPs 2C9, 2D6, 3A4, and UGTs 1A1, 1A10, 2B7. However, which of these is the highest expressed one varies between individuals.</p><p>The correlation in expression between some CYP forms and UGT forms respectively is relatively high, which indicates that they have some regulatory mechanisms in common. It was also shown that the mRNA expression of both CYPs and UGTs may be affected by endogenous and exogenous factors. Sex and ethnic background, affected the mRNA expression of CYP2A6 and 2E1 respectively. Commonly used drugs such as acetylsalicylicacid (ASA) and omeprazole (omep) affect CYP2A6, CYP2E1 (ASA) and CYP3A4, UGT1A4 (omep). The expression of UGT1A4 is also affected by smoking. All these factors are commonly used and can therefore lead to important drug-drug interactions.</p><p>It was also shown that the human small intestinal CYP mRNA expression pattern differs from that found in the rat. The rat CYP expression is rather constant between the different individuals, and the main rat intestinal forms are CYP1A1, CYP2C, CYP2D6 and CYP3A1. The expression is the same for females and males and no difference can be seen between the different segments of the rat small intestine. As metabolic studies have often been done with rat liver we compared the mRNA expression in the two organs. We found that the mRNA expression of 1A1 was absent in the liver and that the CYP2B1, CYP2Cs, CYP2D1 and Pgp all had a stronger mRNA expression in the small intestine compared to the liver. It is therefore important to realise that results from metabolic studies on liver may not be directly extrapolated to the small intestine.</p><p>Artemisinin is an orally used drug in multidrug treatment of malaria in Southeast Asia. It has been suggested that artemisinin can induce drug metabolism and therefore be involved in drug-drug interactions. This study shows that artemisinin induces mainly the CYP2B via nuclear receptor CAR.</p>

This investigation focused on the mRNA expression of drug metabolising Cytochromes P-450 (CYP) and UDP-glucuronosyltransferases (UGT) and the transport protein P-glycoprotein (Pgp) in the small intestine of humans and rats. The mRNA expression of the investigated genes in the human small intestine (duodenum) varies between individuals giving each one of us personal profile. In general, the most dominant forms are Pgp, CYPs 2C9, 2D6, 3A4, and UGTs 1A1, 1A10, 2B7. However, which of these is the highest expressed one varies between individuals. The correlation in expression between some CYP forms and UGT forms respectively is relatively high, which indicates that they have some regulatory mechanisms in common. It was also shown that the mRNA expression of both CYPs and UGTs may be affected by endogenous and exogenous factors. Sex and ethnic background, affected the mRNA expression of CYP2A6 and 2E1 respectively. Commonly used drugs such as acetylsalicylicacid (ASA) and omeprazole (omep) affect CYP2A6, CYP2E1 (ASA) and CYP3A4, UGT1A4 (omep). The expression of UGT1A4 is also affected by smoking. All these factors are commonly used and can therefore lead to important drug-drug interactions. It was also shown that the human small intestinal CYP mRNA expression pattern differs from that found in the rat. The rat CYP expression is rather constant between the different individuals, and the main rat intestinal forms are CYP1A1, CYP2C, CYP2D6 and CYP3A1. The expression is the same for females and males and no difference can be seen between the different segments of the rat small intestine. As metabolic studies have often been done with rat liver we compared the mRNA expression in the two organs. We found that the mRNA expression of 1A1 was absent in the liver and that the CYP2B1, CYP2Cs, CYP2D1 and Pgp all had a stronger mRNA expression in the small intestine compared to the liver. It is therefore important to realise that results from metabolic studies on liver may not be directly extrapolated to the small intestine. Artemisinin is an orally used drug in multidrug treatment of malaria in Southeast Asia. It has been suggested that artemisinin can induce drug metabolism and therefore be involved in drug-drug interactions. This study shows that artemisinin induces mainly the CYP2B via nuclear receptor CAR.

La variabilité interindividuelle dans la réponse aux médicaments constitue une problématique importante pouvant causer des effets indésirables ou l’échec d’un traitement. Ces variabilités peuvent être causées par une diminution de l’activité de l’enzyme responsable du métabolisme de certains médicaments, fréquemment les cytochromes P450, un système enzymatique majeur dans le métabolisme de ces derniers. Ces enzymes sont sujets à des mutations génétiques appelées polymorphismes, qui altèrent l’activité métabolique. Il est donc important d’évaluer le rôle de ces enzymes dans le métabolisme des médicaments afin d’identifier leur responsabilité dans la variabilité interindividuelle de la réponse au traitement. Parmi l’important système enzymatique que représentent les cytochromes P450, l’isoenzyme CYP2D6 est particulièrement étudiée, ses variations métaboliques revêtant une haute importance clinique. L’un des substrats du CYP2D6 est l’oxycodone, un analgésique narcotique largement prescrit en clinique. Une grande variabilité est observée dans la réponse analgésique à l’oxycodone, variabilité pouvant être causée par un polymorphisme génétique. Il est connu que des variations génétiques dans le CYP2D6 compromettent la réponse analgésique à la codéine en rendant moins importante la formation de son métabolite actif, la morphine. Par analogie, plusieurs études supportent l’hypothèse selon laquelle le métabolite oxymorphone, formée par l’isoenzyme CYP2D6, serait responsable de l’analgésie de l’oxycodone. Une déficience génétique de l’enzyme compromettrait la réponse analgésique au médicament. Les travaux effectués dans le cadre de ce mémoire ont démontré que l’inhibition du CYP2D6 chez des sujets volontaires réduit de moitié la production d’oxymorphone, confirmant l’importante implication de l’enzyme dans le métabolisme de l’oxycodone. Ces résultats démontrent une forte ressemblance avec le métabolisme de la codéine, suggérant que l’oxymorphone pourrait être responsable de l’analgésie. Cependant, les travaux effectués n’ont pu établir de relation entre la concentration plasmatique d’oxymorphone et le niveau d’analgésie ressenti par les sujets. La continuation des études sur le mécanisme d’action de l’oxycodone dans la réponse analgésique est essentielle afin d’établir la source des variabilités interindividuelles expérimentées par les patients et ainsi d’éviter des effets secondaires ou lacunes dans le traitement. / Intersubject variability in drug response is an important issue provoking side effects or treatment failure. Such variability may be caused by the decreased activity of the enzyme metabolising the drug, frequently cytochromes P450, a major enzyme system in drug metabolism. These enzymes are prone to genetic mutations called polymorphisms, which alter their metabolic activity. It is therefore important to assess the role of these enzymes to identify their responsibility in the intersubject variability of the drug. Among the important enzyme system that represents the cytochrome P450, CYP2D6 is particularly studied for its genetic polymorphisms, which are of clinical importance. One of CYP2D6 substrates is oxycodone, a narcotic analgesic widely prescribed in clinical practice. A large variability is observed in the analgesic response to oxycodone, which could be caused by genetic polymorphism. It is known that these variations affect the analgesic response to codeine, which form the active metabolite morphine by CYP2D6 to be effective. Several studies support the hypothesis that oxymorphone, a metabolite formed by CYP2D6, has the analgesia properties, in a similar mechanism to codeine. A genetic deficiency in the enzyme would compromise the analgesic response to the drug. Results obtained from our laboratory indicate that inhibition of CYP2D6 halved oxymorphone production, confirming the significant involvement of the enzyme in the metabolism of oxycodone. These results demonstrate a strong resemblance to codeine metabolism, suggesting that oxymorphone may be responsible for analgesia. We could not find a relationship between plasma concentration of oxymorphone and analgesia level experienced by subjects. Studies on oxycodone mecanism of action in the analgesic response should continue to establish the source of intersubject variability experienced by patients and thus avoid side effects or gaps in treatment.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-07-08T21:50:45Z No. of bitstreams: 1 PolianaGabrieleAlvesDeSouzaLins_DISSERT.pdf: 3620813 bytes, checksum: 1d0d398b2d312153ac98a53f411531fd (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-07-13T21:41:13Z (GMT) No. of bitstreams: 1 PolianaGabrieleAlvesDeSouzaLins_DISSERT.pdf: 3620813 bytes, checksum: 1d0d398b2d312153ac98a53f411531fd (MD5) / Made available in DSpace on 2016-07-13T21:41:13Z (GMT). No. of bitstreams: 1 PolianaGabrieleAlvesDeSouzaLins_DISSERT.pdf: 3620813 bytes, checksum: 1d0d398b2d312153ac98a53f411531fd (MD5) Previous issue date: 2015-08-14 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq) / A alimenta??o ? press?o seletiva b?sica de todas as formas de animais. Modelos em ecologia nutricional de primatas prev?em as consequ?ncias do consumo de alimentos preferidos e n?o preferidos no comportamento, fisiologia e morfologia dos animais. Ao mesmo tempo, modelos s?cio-ecol?gicos inferem o padr?o de organiza??o social a partir do tipo de competi??o alimentar enfrentada pelos animais. A defini??o de alimentos preferidos, e infer?ncias sobre a intensidade de competi??o e suas consequ?ncias comportamentais s?o informa??es valiosas para manejo de animais em fragmentos. Neste trabalho observamos o comportamento alimentar e posicionamento espacial de um grupo de mais de 100 macacos-prego galego (Sapajus flavius) que habitam um fragmento de Mata Atl?ntica, cercado por planta??es de cana-de-a??car. N?s comparamos o consumo de diferentes itens alimentares com sua disponibilidade mensal na regi?o para definirmos os alimentos preferidos e reserva, e contabilizamos as vocaliza??es de agress?o e a distancia inter-individual (?rea de m?nimo pol?gono convexo/n indiv?duos) para inferir a intensidade de competi??o alimentar vivenciada pelos animais. No ano estudado o tempo consumindo frutas correlacionou com a produtividade das frutas, indicando prefer?ncia por frutos. Os nossos dados indicam que as esp?cies Elaeis sp., Cecropia palmata, Inga spp. e Simarouba amara s?o os alimentos preferidos na dieta. Dispon?vel durante todo o ano e uniformemente distribu?da, a cana-de-a??car constituiu um item regular na dieta e foi caracterizado como alimento reserva est?vel para este grupo. Embora as frutas sejam itens alimentares preferenciais, a taxa de competi??o direta n?o se correlacionou com a sua produtividade, mantendo-se a ?ndices elevados durante todo o ano (2,45 eventos / hora). O ?ndice de distancia inter-individual correlacionou positivamente com a pluviometria indicando varia??o na competi??o indireta por alimentos. O n?mero de vizinhos das f?meas com filhotes foi menor quando a produtividade de frutos era baixa, indicando que elas est?o sofrendo alta competi??o indireta. Nossos dados indicam que esse grupo faz uso de cana-de-a??car como alimento reserva est?vel, o que evidencia a import?ncia da matriz circundante ao fragmento para a sobreviv?ncia desta esp?cie criticamente amea?ada de macaco-prego no Nordeste do Brasil. Uma lista preliminar de alimentos preferidos e importantes ? ofertada, e pode auxiliar na escolha de ?rvores para reflorestamento e corredores, e escolha de fragmentos a serem conservados e ?reas de soltura e transloca??o de animais. N?o verificamos aumento de competi??o direta durante o uso de alimentos preferidos, mas sim durante o uso de alimento reserva est?vel. Isso pode dever-se ao ambiente alterado, que resulta em alta competi??o alimentar durante todo o ano. Tanto a preferencia alimentar quanto as consequ?ncias s?cio-comportamentais da alta competi??o alimentar vivenciada pelos animais neste fragmento precisam ser acompanhadas ao longo dos anos para assegurar a sobreviv?ncia desta popula??o. / Feeding is the primary selective pressure in all forms of animals. Nutritional ecological models predict consequences of preferred and non-preferred food consumption on behavioural, physiological and morphological adaptations. At same time, socioecological models infer socio-organizarion patterns based on feeding competition faced by animals. A list of preferred foods, and inferences regarding the intensity of feeding competition and its behavioural consequences are information of much importance for management of populations in fragments. In this work we observed the feeding behavior and spatial positioning of a group of more than 100 blond capuchin monkeys (Sapajus flavius) that inhabit a fragment of Atlantic forest, surrounded by sugarcane plantation. We compared the consumption of different food items with their monthly availability in the area to define the preferred and fallback food items. We recorded the vocalizations of aggression and the inter-individual distance (area of Minimum Convex Polygon/n individuals) to infer the type of food competition experienced by animals. In the year studied the fruit feeding time correlated with top consumed fruit productivity, indicating preference for fruits. Our data indicate that the species Elaeis sp., Cecropia palmata, Inga spp. and Simarouba amara are the preferred food items in the diet. Available all year round and uniformly distributed, sugarcane was a regular item in the diet and its was characterized as a staple fallback food for this group. Although fruits are preferential food items, direct competition rate did not correlate to fruit productivity in the area, maintaining the high rates throughout the year (2.45 events/ hour). The inter-individual distance index positively correlated with rain fall indicating scramble food competition. The number of neighbours of females carrying infants was smaller when fruit productivity is low, indicating that females carrying infants are suffering increased indirect competition. Our data indicates that blond capuchins in this fragment make use of sugar cane as a staple fallback food, which evidence the importance of sugar cane landscape for the survival of this critically endangered capuchin species in fragmented habitats in Northeast Brazil. A preliminary list of preferred and important foods is offered, and can assist in the choice of trees for reforestation, better fragments to be preserved and areas of release and translocation of animals. We did not observe an increase of contest competition while using preferred foods, but when using staple FBF. This may be due the altered environment, which results in high competition food throughout the year. Both the food preference as the social and behavioral consequences of high food competition experienced by animals in this fragment must be accompanied over the years to ensure the survival of this population.