Cette thèse se divise en deux parties. La première est consacrée aux points entiers sur les courbes modulaires, et l'autre se concentre sur les courbes elliptiques à couplages.Dans la première partie, nous donnons quelques majorations effectives de la hauteur des j-invariants des points entiers sur les courbes modulaires quelconques associées aux sous-groupes de congruence sur les corps de nombres quelconques en supposant que le nombre des pointes est au moins 3. De plus, dans le cas d'un groupe de Cartan non-déployé nous fournissons de meilleures bornes. Comme application, nous obtenons des résultats similaires pour certaines courbes modulaires avec moins de 3 pointes.Dans la deuxième partie, nous donnons une nouvelle majoration du nombre de classes d'isogénie de courbes elliptiques ordinaires à couplages. Nous analysons également la méthode de Cocks-Pinch pour confirmer certaines de ses propriétés communément conjecturées. Par ailleurs, nous présentons la première analyse heuristique connue qui suggère que toute construction efficace de courbes elliptiques à couplages peut engendrer efficacement de telles courbes sur tout corps à couplages. Enfin, quelques données numériques allant dans ce sens sont données.

A la veille d’une nouvelle conférence sur le climat, les questions environnementales demeurent plus que jamais au premier plan de la vie publique. La lutte contre le réchauffement climatique, et les émissions de gaz à effet de serre, dont l’attribution à l’activité humaine fait globalement l’objet d’un consensus scientifique, constituent l’un des plus grands défis de l’humanité pour les prochaines années. Dans ce contexte, l’amélioration de l’efficacité énergétique des sites de production est une des préoccupations des industriels. Les réglementations environnementales, et les fluctuations des cours de l’énergie les forcent à continuellement améliorer leurs procédés pour en maintenir la compétitivité. Ceux-ci doivent ainsi pouvoir disposer d’outils leur permettant d’effectuer des diagnostics énergétiques sur les installations, leur facilitant la prise de décision et leur permettant d’élaborer des solutions d’efficacité énergétique sur leurs sites industriels. Les travaux présentés dans ce document visent à introduire une méthodologie d’analyse et de rétro-conception pour l’amélioration énergétique des procédés industriels. Cette méthodologie, qui s’appuie sur une utilisation combinée de la méthode du pincement et de l’analyse exergétique, se décompose en trois grandes étapes : la première comprend le recueil des données, la modélisation et la simulation du procédé. La deuxième étape, dédiée à l’analyse du procédé, est elle-même divisée en deux phases. La première, qui s’appuie pour l’essentiel sur l’utilisation de la méthodologie du pincement, s’intéresse uniquement à l’analyse du système de fourniture et de récupération de l’énergie thermique. Si cela s’avère nécessaire, le procédé complet est étudié dans une deuxième phase. L’analyse pincement se limitant à l’étude des procédés thermiques, une méthodologie d’analyse exergétique est mise en œuvre. Cette méthodologie s’appuie sur l’implémentation de l’analyse exergétique dans l’environnement ProSimPlus, entreprise par Ali Ghannadzadeh, et poursuivie pendant cette thèse. Les formules d'exergie ont été affinées pour s’ajuster aux différents modèles thermodynamiques. L’approche d’analyse proposée dans ce manuscrit est basée sur l’utilisation d’une nouvelle représentation graphique des bilans exergétiques : le ternaire exergétique. Ce dernier permet d’illustrer tous les aspects des bilans exergétiques et ainsi d'assister l’ingénieur dans l’analyse du procédé. La troisième étape s’intéresse à la conception pour l’amélioration énergétique. Alors que l’analyse du pincement propose des solutions d’amélioration, l’analyse exergétique ne le permet pas. Elle nécessite l’apport d’une certaine expertise pour aboutir au développement de solutions d’améliorations. Pour pallier ce problème, l’expertise est en partie capitalisée dans un système de raisonnement à partir de cas. Ce système permet de proposer des solutions à des problèmes nouveaux en analysant les similarités avec des problèmes anciens. Cet outil se révèle utile pour définir des solutions locales d’améliorations énergétiques. L’analyse du pincement associée à des outils numériques est ensuite utilisée pour concevoir des propositions complètes d’améliorations. La seconde partie de ce manuscrit présente cette étape. / On the eve of a new conference on climate change, environmental issues remain more than ever at the forefront of public life. Tackling climate change, and reducing greenhouse gases emissions, that are largely attributable to human activity, represents one of the biggest challenges for humanity in the coming years. In such a context, the promotion of best practices to enable an efficient utilization of energy has emerged as one of the major point of focus. High volatility of energy prices and the increasingly stringent environmental regulations have forced industrials to continuously improve their processes in order to cut the energy consumption down and reduce GHG emissions. For this purpose, industrials need tools to perform energy audits on facilities, to ease decision-making and to enable them to develop their energy efficiency solutions on their sites. In this context, the study presented in this dissertation aims at introducing a new systematic procedure for energy diagnosis and retrofit of industrial processes. This methodology presented in this dissertation is divided into three stages: the first involves the data collection, the modeling and simulation of the process. The second stage, dedicated to the analysis of the process, is subdivided into two phases. The first, which is essentially relying on the Pinch methodology, is only concerned with the analysis of the thermal energy supply and recovery system. If necessary, the complete process is studied in the second phase of the analysis. Pinch analysis being limited to the analysis of thermal systems, an exergy analysis methodology is then implemented. This methodology is based on the implementation of the Exergy analysis in the ProSimPlus modelling and simulation environment, undertaken by A. Ghannadzadeh, and pursued in this study. The formulas proposed by Ali Ghannadzadeh have been adjusted to take into account different thermodynamic approaches. A new graphical representation of exergy balances, the exergetic ternary diagram, is also introduced to assist engineers in the analysis process. It enables to illustrate all aspects of exergy balances, i.e. the irreversibility, the exergy losses and the exergy efficiencies of each unit operation. The automation of this new graphical layout was made possible by the implementation of a generic exergy efficiency in the simulator. This analysis paves the way to the third step of the overall methodology dedicated to retrofitting. This methodology is detailed in the first part of this dissertation. While Pinch analysis proposes improvement solutions, the Exergy analysis does not. The key to achieving a significant exergy analysis lies in the engineer’s ability to propose alternatives for reducing thermodynamic imperfections, thus exergy analysis is supposed to be undertaken by an experienced user. To overcome this problem, the expertise is partly capitalized in a case-based reasoning system. This system allows the proposition of solutions to new problems by analyzing the similarities with solved problems. This tool is useful for defining local solutions for energy improvements. The Pinch analysis combined to numerical tools is then used to develop alternatives. This third step is developed in the third part of the manuscript.

Thesis submitted in fulfilment of the requirements for the degree of Master of Technology: Chemical Engineering, In the Faculty of Engineering, Cape Peninsula University of Technology 2014 / Energy efficiency has become an important feature in the design of process plants due to the rising cost of energy and the more stringent environmental regulations being implemented worldwide. In South Africa as in other African countries, most of the chemical plants were built during the era of cheap energy with little emphasis placed on energy efficiency due to the abundance of cheap utility sources such as coal and crude oil. In most of these plants, there exists significant potential for substantial process heat recovery by conceptual integration of the plant’s heat exchangers. Pinch Technology (PT) has been demonstrated to be a simple and very effective technique for heat integration and process optimization. This study applies the PT approach to retrofit the heat exchangers network of the Crude Distillation Unit (CDU), of a complex petroleum refinery with the aim to reduce utilities requirement and the associated gaseous pollutants emission. This objective is accomplished by firstly conducting an energy audit of the unit to scope for potential energy saving. The existing Heat Exchanger Network (HEN) was re-designed using the remaining problem analysis (RPA) to achieve improved process energy recovery while making maximum use of the existing exchangers. The aim is to maintain the existing plant topology as much as possible. This network was later relaxed trading heat recovery with number of heat transfer unit so as to optimize the capital cost. These were implemented in AspenPlus v7.2 environment. The cost implications of the retrofitted and evolved networks including the capital and operating costs were determined on a 5 years payback time basis. The Problem Table (PT) analysis revealed that the minimum utilities requirements are 75 MW and 55 MW for the hot and cold utilities respectively. Compared to the existing utilities requirements of 103 MW for hot utility and 83 MW for cold utility, this represent a potential savings of about 26 % and 33 % savings for the hot and cold utilities respectively. The target utilities usage in the re-designed network after applying Remaining Problem Analysis (RPA) was found to be 55 MW for the cold utility and 75 MW for hot utility. The relaxed HEN required a cold utility of 62.5 MW and hot utility of 81 MW. From the total cost estimation, it was found that, although an energy saving of 34% can be achieved by the re-designed network before relaxation, the capital cost, US$ 1670000 is significantly higher than for the existing network (about US$ 980000). The final relaxed network gave an energy saving of 34% and with total cost of US$ 1100000. It was recommended from the study after cost comparisons of the four different networks (the original network, the MER network, the relaxed network and a grass-root design) that the best network for the retrofit purpose was the relaxed HEN, because there is no major shift in deviation from the topology of the original network. From the analysis it was found that a 34% saving in energy cost could be achieved from this retrofit. The Total Annual Cost (TAC) for this network gives credence to the fact that this retrofit which applied the rules of pinch analysis can bring about real saving in energy usage.

Este trabalho tem como objetivo analisar a tecnologia do ciclo refrigerante misto para obtenção de gás natural liquefeito (GNL). Nessa tecnologia, o GNL é obtido por meio do seu resfriamento através de um ciclo de refrigeração, cujo fluido refrigerante é formado por uma mistura de diversos componentes. O ciclo de refrigeração é usado para resfriar a corrente de gás natural até as condições criogênicas por meio de um trocador de calor. A determinação da composição ótima dessa mistura de refrigerantes é de suma importância para a correta e eficiente operação da planta. O modelo termodinâmico para o cálculo de equilíbrio de fases dos componentes da mistura refrigerante é o baseado na Lei de Raoult, válido para misturas e soluções ideais. Inicialmente, revisam-se os conceitos de refrigerantes mistos, curvas compostas e o ponto de pinça (pinch point), utilizados na implementação da solução computacional. A aplicação dos modelos de gás e solução ideal influencia nos resultados, mas, não obstante, produz bons resultados como os obtidos no presente trabalho. A operação eficiente do ciclo depende, sobretudo, de três parâmetros principais, quais sejam: vazão da mistura refrigerante, razão de pressões alta e baixa do ciclo de refrigeração e composição da mistura refrigerante. Da análise dos resultados obtidos conclui-se que a alteração nas proporções da composição do refrigerante muda significativamente a forma das curvas composta quente e composta fria, quando comparados à alteração dos níveis de pressão e da vazão do ciclo refrigerante. Entretanto, a operacionalização do ciclo somente ocorre se um dado conjunto de valores daqueles parâmetros satisfaça uma determinada diferença mínima de temperatura, ou ponto de pinça, entre as curvas composta quente e composta fria dentro do trocador de calor. Assim, a operação eficiente do ciclo de refrigeração requer a otimização daqueles três parâmetros operacionais. / This work has the objective of analyzing the technology of mixed refrigerant cycle for obtaining liquefied natural gas (LNG). In that technology, the liquefied natural gas is obtained by means of cooling through a refrigeration cycle, whose fluid refrigerant is formed by a mixture of various components. The refrigeration cycle is used to cool the natural gas stream to cryogenic condition with the use of a heat exchanger. The determination of the optimal composition of this refrigerant mixture is very important for the correct and efficient operation of the plant. The thermodynamic model for the equilibrium phase calculation of the refrigerant mixture is based on the Law of Raoult, which is valid for ideal mixtures and solutions. Initially, the concepts of refrigerant mixture, composite curves and pinch point used in the implementation of the numerical solution were reviewed. The application of ideal-gas and ideal-solution models has influence on the results. Nevertheless, it produces good results as those obtained in the present work. The efficient operation of the cycle depends essentially of three key parameters, which are: refrigerant flow rate, the ratio of high to low pressures of the refrigerant cycle and the mixed refrigerant composition. The results indicated that the composition variation of the refrigerant changes significantly the shape of hot and cold composite curves in comparison to the modification in the pressure levels and the refrigerant flow rate of the refrigerant cycle. However, the process will operate only if a given set of values of those parameters satisfies a minimum temperature difference, or pinch point, between the hot and cold composite curves within the heat exchanger. Thus, the efficient operation of the refrigerant cycle requires the optimization of those three operational parameters.

La méthode du Pincement a été développée et utilisée dans le secteur de la pétrochimie. Le nombre de flux y est important et la consommation énergétique est un critère décisionnel fort. D'autres secteurs énergivores tels la métallurgie, la production de papier et de pâte à papier ou l'industrie agroalimentaire peuvent bénéficier de cette approche structurée. Par ailleurs, l'intégration d'utilités thermodynamiques complexes comme les pompes à chaleur ou les unités de cogénération peut réduire significativement la consommation d'énergie d'un procédé, sans avoir à en modifier la technologie.Un algorithme de conception d'un réseau d'échangeurs à partir de flux thermiques à été choisi dans la littérature, puis deux fonctionnalités lui ont été ajoutées : la différenciation des technologies d'échangeur et la prise en compte de flux "disponibilités" à température de sortie variable. Un module de présélection a été développé pour proposer et dimensionner des utilités thermodynamiques à partir de la grande courbe composite et d'un critère exergétique. Il est utilisé en amont de la conception du réseau d'échangeurs.Ces deux algorithmes ont été intégrés dans un logiciel dédié à l'intégration énergétique de procédés à partir des flux thermiques des opérations unitaires. Plusieurs validations ont été faites sur des cas théoriques de référence issus de la littérature ainsi que sur des cas industriels réels nécessitant la modélisation des procédés. L'enchainement des deux algorithmes débouche sur l'obtention de résultats concrets et technologiquement réalistes. L'amélioration apportée par les solutions est calculable à chaque étape. / The pinch analysis has been developed and exploited in the petrochemical sector. There are numerous heat fluxes and energy consumption is a strong decision criterion. Other energy-intensive sectors such as metallurgy, pulp and paper and food & drink industry can benefit from this systemic approach. Moreover, integration of complex thermodynamic utilities such heat pumps or Combined Heat and Power units can significantly reduce the energy consumption of a process, without having to interfere with the process technology.An algorithm for heat exchangers network design from heat fluxes was chosen in the literature and two features were added to it: Ability to pick different heat exchanger technology and creation of "availabilities" heat fluxes whose outlet temperature is variable. Preselection tool has been developed from grand composite curve and exergetic criterion to propose and pre-size thermodynamics utilities. It is used upstream of the heat exchangers network design step.These two algorithms have been integrated into a software for energy integration of process unit operations heat fluxes. Several validations were made on study cases from the literature as well as on industrial cases which require process modelling. The both algorithms sequence allows achieving practical and technologically feasible results. Improvement on energy consumption provided by the solutions can be calculated at each step.

I den här uppsatsen presenteras en studie av rörelsebaserad zoom (Device Movement Based Zoom) och nyp-zoomning (Pinch-zoom). Rörelsebaserad zoom innebär att användaren zoomar in genom att gå närmare ett objekt och zoomar ut genom att gå längre bort från det. Nyp-zoomning innebär att användaren zoomar genom nyp-gester med två fingrar på plattformens pekskärm. Syftet var att undersöka vilka likheter och skillnader som finns mellan de båda systemen ur ett användarperspektiv samt om engagemanget blir större när rörelserna blir större och användaren tvingas vara mer aktiv (med kroppen) vid interaktionen med systemet. De 24 deltagarna i studien testade två olika system, ett med vardera typen av zoom, och både kvalitativ och kvantitativ data samlades in genom enkäter. Resultatet visade att systemen hade nästan lika hög popularitet (på frågan; vilken av de två systemen skulle du föredra?). Däremot var svaren på frågan influerade av vilken telefon de hade till vardags. De som var vana att använda en telefon med knappar för navigering föredrog rörelsebaserad zoom i större utsträckning och de som var vana att använda pekskärm föredrog nyp-zoom i större utsträckning. Samma tendens syntes genomgående i all insamlad data. En tendens till att systemet med rörelsebaserad zoom gav högre engagemang hos användarna gick att se, men inga signifikanta skillnader fanns för hela gruppen. Tendensen var störst för delkategorierna upplevt engagemang och stabilitet. När deltagarna delades upp efter vilken mobiltelefon de var vana att använda syntes tendensen att de båda systemen ansågs mer likvärdiga i självskattat engagemang för de som sen tidigare var vana att använda nyp-zoom. De som inte var vana att använda nyp-zoom (deltagarna som använde knapptelefoner till vardags) märkte en större skillnad på systemen. Signifikanta skillnader sågs här under det totala engagemanget samt för delkategorierna stabilitet och upplevt engagemang. Värt att notera är att gruppstorleken var väldigt ojämn och antalet deltagare som var vana att använda en knapptelefon var väldigt lågt. Rörelsebaserad zoom upplevdes som naturlig och mer fri, medan nyp-zoom är smidigt att använda i vissa situationer då det inte kräver någon plats att gå omkring. En annan fördelmed nyp-zoom är att 3d-modellerna inte försvinner som de kan göra med den rörelsebaserade zoomen eftersom hela markören behöver vara i bild i enhetens kamera för att 3d-modellen ska visas. Däremot verkar nyp-zoom vara relativt svårt att använda för de som inte är vana vilket också syntes i de kvalitativa data. För att kunna säga mer hur väl resultatet kan generaliseras, till exempel med fokus på kroppslig interaktion och om något av sätten att zooma är att föredra över lag uppmuntras fler liknande studier.

Les systèmes sédimentaires turbiditiques ont de tout temps présenté un intérêt pour la recherche académique et industrielle. Ils correspondent à d’importantes accumulations sous-marine, à l’organisation complexe et se développant au pied des marges continentales. Les processus gravitaires assurant le transport des matériaux au sein de ces systèmes sont variés et organisés selon un continuum longitudinal évoluant depuis les dépôts les plus concentrés vers des courants turbulents à l’aval via des effets de perte de charge et d’incorporation d’eau. Parmi les nombreux paramètres contrôlant l’organisation de ces systèmes, l’inclinaison de la pente continentale apparait comme un paramètre majeur. Les découvertes récentes de réservoirs pétroliers au pied de marges dites abruptes, associées à des pièges stratigraphiques suscitent un intérêt particulier des industriels sur les modalités de mise en place de ces systèmes à la transition entre la zone de bassin et la pente. L’analyse des architectures de dépôt, et des variations hydrodynamiques des écoulements, dans ces zones critiques de fermeture des réservoirs apparait comme cruciale d’un point vu académique et pétrolier. Les systèmes turbiditiques du bassin de Tabernas en Espagne (Tortonien supérieur/Messinien préévaporitique) d’une part, les Grés d’Annot dans le bassin du Sud-Est (France, Eocène/Oligocène) d’autre part et enfin les systèmes Crétacés de la marge Ivoirienne se développent dans des contextes de marge abrupte. Ils présentent des profils de pentes escarpées constituant de bons analogues adaptés à l’étude de la mise en place de ce type de réservoirs pétroliers. Ce travail se base sur des données de terrain (relevés de logs sédimentologiques, cartographie, mesure de paléo-courant) et sur l’analyse d’un bloc de sismique 3D le long de la marge Ivoirienne pour renforcer la pertinence des comparaisons. Les dépôts de ces systèmes turbiditiques témoignent des processus de ségrégation des écoulements avec un piégeage préférentiel des particules les plus grossières localisé au niveau des variations de pente le long du thalweg. Ces variations de la topographie sont à l‘origine de ressaut hydraulique entrainant une modification des écoulements. L’étude fine de l’architecture et de la mise en place de ces dépôts formant le biseau amont de ces systèmes sur la pente, apporte des avancées inédites sur les continuums de dépôts des écoulements au sein des zones de canyon et à la transition canyon/bassin. De plus, cette analyse met en évidence l’impact des zones de rupture de pente et du phénomène de ressaut hydraulique pouvant en découler. Le caractère pseudo tridimensionnel de tous les affleurements étudiés, semble au moins partiellement valider l’existence de biseaux amonts des systèmes turbiditiques. Néanmoins aucun d’entre eux ne permet de documenter le recouvrement amont par des argiles ; lesquelles assureraient en conditions réelles la qualité de la couverture. En amont de ces zones de biseaux, la présence de zone de By-pass des écoulements gravitaires apparait liée à l’augmentation de la pente et aux transformations des écoulements au passage des zones de ressaut hydraulique. Les modalités de biseaux amont des systèmes turbiditiques sont directement reliées à la présence de zone de changement de pente, où le phénomène de ressaut hydraulique entraine le dépôt d’une partie de la charge sédimentaire la plus grossière des écoulements sous forme de lags deposits s’accompagnant ou non d’une érosion partielle du fond marin. Cette érosion peut prendre la forme de structure du type plunge and pool dans le cas d’une diminution importante de la pente. Les biseaux peuvent également se mettre en place par des phénomènes d’érosion/dépôts régressifs sur la pente. Ce travail a été réalisé dans le cadre d’une thèse CIFRE en partenariat avec l’université Côte d’Azur, le groupe TOTAL et le laboratoire de Géoazur. / Turbidite systems present both academic and industrial interest for research. They correspond to important marin accumulations developing at the base of the continental slope, with a complex organization. The gravitational processes for transporting materials within these systems are varied and organized along a longitudinal continuum evolving from the most concentrated deposits to turbulent downstream currents through pressure drop and water incorporation effects. Among the many parameters controlling the organization of these systems, the inclination of the continental slope appears as a major parameter. The recent discoveries of oil reservoirs at the foot margins considered as “steep” associated with stratigraphic traps arouse particular industrial interest in the methods of setting up these systems at the transition between the basin zone and the slope. The analysis of the deposition architectures, and the hydrodynamic variations of the flows in these critical zones of field appears as crucial from an academic and petroleum point of view. The turbidite system of the Tabernas Basin in Spain (Upper Tortonian / Messinian Pre-Evaporitic), the Annot Sandstone in the South-East Basin (France, Eocene / Oligocene) and the Cretaceous system of the Ivorian margin develop in steep margin contexts with steep slopes profiles constituting good analogs adapted to the study of this type of stratigraphic trap. This work is based on field data (sedimentological log survey, cartography, paleocurrent measurement) and on the analysis of a 3D seismic block along the Ivorian margin to reinforce the relevance of the comparisons. Deposits of these turbidite system indicate segregation processes with preferential trapping of the coarser particles located in the upstream zones at the level of the slope break along the thalweg. These variations of the topography initiated a hydraulic jump causing a change in the flow condition. The detailed study of the architecture and the formation of these deposits forming the upstream pinch-out on the slope brings a new light on the continuity of these sandbodies within the zones of canyon and the transition canyon / basin. In addition, this analysis highlights the impact of the slope failure zones and the hydraulic jump phenomenon that may result. The pseudo-three-dimensional character of all outcrops studied seems to validate the existence of upstream pinch-out of turbidite systems. Nevertheless, none of them allows to document the upstream recovery by clays; which would ensure in real conditions the quality of the cover. Upstream of these pinch-out, the presence of by-pass zones appears related to the increase of the slope gradient and the flows transformations while crossing the hydraulic jump. The upstream pinch-out modalities of turbidite systems are directly related to the presence of a slope break where the hydraulic jump phenomenon causes the deposition of a part of the coarsest sediment load as lags deposits accompanied partial erosion of the seabed, often taking the form of plunge and pool in the case of a significant decrease of the slope. This work was conducted as part of a CIFRE thesis in partnership with the Côte d'Azur University, the TOTAL group and the Géoazur laboratory.

<p>Current gasoline blend planning practice is to optimize blend plans via discrete-time multi-period NLP or MINLP models and schedule blends via interactive simulation. Solutions of multi-period models using discrete-time representation typically have different blend recipes for each time period. In this work, the concept of an inventory pinch point is introduced and used it to construct a new decomposition of the multi-period MINLP problems: at the top level nonlinear blending problems for periods delimited by the inventory pinch points are solved to optimize multi-grade blend recipes; at the lower level a fine grid multi-period MILP model that uses optimal recipes from the top level is solved in order to determine how much to blend of each product in each fine grid period, subject to minimum threshold blend size. If MILP is infeasible, corresponding period between the pinch points is subdivided and recipes are re-optimized.</p> <p>Two algorithms at the top level are examined: a) multi-period nonlinear model (MPIP) and b) single-period non-linear model (SPIP). Case studies show that the MPIP algorithm produces solutions that have the same optimal value of the objective function as corresponding MINLP model, while the SPIP algorithm computes solutions that are most often within 0.01% of the solutions by MINLP. Both algorithms require substantially less computational effort than the corresponding MINLP model. Reduced number of blend recipes makes it easier for blend scheduler to create a schedule by interactive simulation.</p> / Master of Applied Science (MASc)

Eating disorders are serious psychological disorders associated with debilitating lifestyle, multiple health problems and high rates of suicidality and mortality. Despite extensive research, the aetiology of eating disorders still remains unclear. Amongst the identified risk factors for eating disorders, stress has been frequently studied. The purpose of the present study was to explore the possibility that tail-pinch administered to rats could provide an animal model of stress-induced eating disturbances in humans, and whether environmental enrichment might ameliorate the effects of stress. In Experiment 1, we compared eating behaviours of rats that were reared in either enriched or standard environments and later exposed to tail-pinch and allowed to eat when food deprived. The study showed that a single exposure to tail-pinch induced eating disturbances in most of the rats. When rats were not food deprived, but were conditioned to eating when placed in test chamber, tail-pinch suppressed eating in all rats, but significantly more for rats reared under standard than in enriched conditions. Experiment 2 used a between-subjects design in which rats were reared in either a standard or enriched environment, and were either exposed to tail-pinch or not exposed during sessions in which they were not food deprived and allowed to eat. Tail-pinch suppressed the food intake of rats reared in enriched but not standard environments. Although this finding appeared to contradict results of Experiment 1, analysis of body weight revealed that exposure to tail pinch suppressed increases in weight gain across sessions more for rats reared in standard than enriched environments. The suppression of food intake during test sessions for enriched but not standard rats exposed to tail-pinch was attributed to differences in contextual conditioning and discrimination of the test chamber from home cages. Overall, results of the present study suggest that rats reared in enriched environments were more resilient to the effects of tail-pinch as a stressor. Implications of these findings for the understanding of human eating disorders are discussed.

INTRODUÇÃO: As distrofias musculares de cinturas (DMC) representam um grupo heterogêneo de desordens hereditárias e degenerativas da musculatura esquelética, com evolução progressiva, caracterizadas pelo acometimento predominante das cinturas escapular e/ou pélvica. São classificadas de acordo com o padrão de herança e o gene envolvido, podendo ser autossômicas dominantes ou autossômicas recessivas. No presente estudo, foi feita a análise de pacientes com diagnóstico de distrofia muscular de cinturas 2B (DMC2B). Trata-se de condição autossômica recessiva, cujo gene envolvido na sua fisiopatologia é o DYSF; sua mutação pode associar-se a alterações na proteína disferlina. OBJETIVOS: Avaliar a distribuição da fraqueza muscular na distrofia muscular de cinturas 2B com ênfase no acometimento dos membros superiores; realizar avaliação objetiva da força muscular para preensão palmar e pinças; correlacionar a força muscular dos diferentes movimentos com a idade de início dos sintomas, idade na ocasião da avaliação, tempo de evolução da doença e capacidade funcional. METODOLOGIA: Estudo prospectivo, observacional, corte transversal, caso-controle. Foi feita avaliação clínica da força muscular de membros superiores e superiores dos pacientes, através de instrumentos clínicos específicos e dinamômetro de pinça e de preensão palmar; adicionalmente, foram aplicadas escalas de capacidade funcional (Escala de Vignos e Escala de Brooke). RESULTADOS: Foram avaliados 12 pacientes com diagnóstico molecular confirmado de DMC2B e recrutados 41 pacientes para o grupo controle. Os grupos não diferiram por gênero nem nas médias etárias. A média da idade de início dos sintomas dos pacientes foi de 26,9 anos (DP 10,05); a idade média na ocasião da avaliação foi de 43,6 anos (DP 9,34). A avaliação clínica da força muscular evidenciou maior acometimento de membros inferiores em relação aos membros superiores. A dinamometria de pinça (bidigital e trigidital) e de preensão palmar evidenciou diferença significativa entre os pacientes e o grupo controle para todos os movimentos citados. Os valores de CK apresentaram média de 2769 U/L (cerca de quinze vezes o limite superior de normalidade). As escalas de avaliação de capacidade funcional evidenciaram uma correlação significativa entre a idade do paciente na ocasião da avaliação e o escore na escala de Brooke. CONCLUSÃO: A análise do padrão de fraqueza dos pacientes com DMC2B evidenciou acometimento de membros inferiores e também de membros superiores. A análise objetiva com dinamometria demonstrou acometimento em todos os movimentos avaliados, evidenciando o envolvimento distal de membros superiores. A análise da capacidade funcional de membros superiores apresentou correlação com idade na avaliação (quanto maior a idade do paciente, maior o grau de incapacidade para membros superiores). Os valores de CK e de força muscular correlacionaram-se com a idade do início dos sintomas e idade na avaliação, ou seja, o início mais precoce da doença correlacionou-se com quadros mais graves (maiores valores de CK e maior envolvimento de força muscular - principalmente distal de membros superiores) / INTRODUCTION: Limb-girdle muscular dystrophies (LGMD) are a heterogeneous group of hereditary and degenerative disorders of the skeletal muscle, with progressive evolution, characterized by the predominant involvement of the scapular and / or pelvic girdles. They are classified according to the inheritance pattern and the involved gene, being autosomal dominant or autosomal recessive. In the present study, we evaluated patients with a diagnosis of 2D (LGMD2B). The LGMD2B is an autosomal recessive condition whose gene involved in its pathophysiology is DYSF; its mutation may be associated with changes in protein dysferlin. OBJECTIVES: To assess the distribution of muscle weakness in 2D womb muscular dystrophy with emphasis on upper limb involvement; perform objective evaluation of muscle strength for palmar grip and forceps; to correlate the muscular strength of the different movements with the age of onset of symptoms, age at the time of evaluation, duration of disease and functional capacity. METHODS: Prospective, observational, cross-sectional, case-control study. Clinical evaluation of the muscular strength of the upper and upper limbs of the patients was made through specific clinical instruments and pinch dynamometer and palmar grip; In addition, functional capacity scales were applied (Vignos Scale and Brooke Scale). RESULTS: Twelve patients with confirmed molecular diagnosis of DMC2B were evaluated and 41 patients were recruited for the control group. The groups did not differ by gender nor in the age groups. The mean age of onset of the patients\' symptoms was 26.9 years (SD 10.05); the mean age at the time of the evaluation was 43.6 years (SD 9.34). The clinical evaluation of muscle strength showed a greater involvement of the lower limbs in relation to the upper limbs. Pinch dynamometry (bidigital and trigidital) and handgrip dynamometry showed a significant difference between the patients and the control group for all the mentioned movements. CK values presented a mean of 2769 U / L (about eight times the upper limit of normality); there was a significant negative correlation (p <0.01) between the age of the patient at the time of the evaluation and the maximum value of CK. The functional capacity evaluation scales showed a significant correlation between the age of the patient at the time of the evaluation and the score on the Brooke scale. The correlation values between the muscular strength between the different movements evaluated and the age of onset of symptoms, age at the time of evaluation and time of evaluation of the disease presented values of significance close to 0.05 for the upper limb distal muscles and age of onset and age at the time of evaluation. CONCLUSION: The analysis of the weakness pattern of patients with LGMD2B showed involvement of lower limbs as well as upper limbs. Objective analysis with dynamometry showed involvement in all the movements evaluated, showing the distal involvement in the upper limbs. The analysis of functional capacity of upper limbs showed correlation with age in the evaluation (the higher the patient\'s age, the greater the degree of incapacity for upper limbs). The values of CK and muscle strength correlated with the age of onset of symptoms and age at the assessment, ie the earlier onset of the disease was correlated with more severe conditions (higher CK values and greater involvement of muscle strength - mainly distal upper limbs)