Henri Poincaré: The Status of Mechanical Explanations and the Foundations of Statistical Mechanics

The first goal of this paper is to show the evolution of Poincaré’s opinion on the mechanistic reduction of the principles of thermodynamics, placing it in the context of the science of his time. The second is to present some of his work in 1890 on the foundations of statistical mechanics. He became interested first in thermodynamics and its relation with mechanics, drawing on the work of Helm-holtz on monocyclic systems. After a period of skepticism concerning the kinetic theory, he read some of Maxwell’s memories and contributed to the foundations of statistical mechanics. I also show that Poincaré's contributions to the founda-tions of statistical mechanics are closely linked to his work in celestial mechanics and its interest in probability theory and its role in physics

Uma análise do feminino em “A ceia”, de Lygia Fagundes Telles

Lygia Fagundes Telles posiciona-se como uma escritora-testemunha de seu tempo, assim como uma mulher do século 20 a vivenciar e defender as lutas em prol da liberdade feminina. Atenta aos paradigmas sociopolíticos vigentes, sem ignorar a natureza ficcional e estética da arte, a autora constrói uma literatura disposta a desvelar (e também subverter) o status quo em suas múltiplas nuances por meio de personagens femininas vibrantes e de temáticas como amor, casamento e traição. Considerando essas questões, propomos neste ensaio uma análise da representação do feminino no conto “A ceia”, presente na antologia Antes do baile verde, publicada pela primeira vez em 1970 pela Editora Bloch. Para tanto, discutimos como, no conto, figuram representações do feminino nas personagens Alice e Olívia, em que se revela uma tensão dialética entre as imposições sociais do patriarcado e sua subversão. 

Lower between-limb asymmetry during running on treadmill compared to overground in subjects with laterally pronounced knee osteoarthritis

Subjects with knee osteoarthritis (KOA) show gait asymmetries evidenced by lower knee flexion and shorter contact times for the affected leg. Interestingly, running on a treadmill compared to running overground is also associated with lower knee flexion and shorter contact times. Thus, it is of particular interest how gait patterns are influenced by the type of ground in subjects with KOA. The aim of the current study was therefore to measure the overground asymmetry of kinematic parameters in KOA subjects while running and to investigate whether this asymmetry is altered on a treadmill. Nine patients diagnosed with KOA underwent overground and treadmill running with 3D-motion analysis. The symmetry analysis was performed using Symmetry Angles for five selected gait parameters: contact and step time, heel-toe delay, maximal knee flexion during stance and vertical speed variance. For all parameters, the values were significantly lower for the affected compared to the non- affected leg (p≤0.023). Post-hoc analyses revealed significant differences between legs only overground and not on the treadmill. The asymmetry was lower on the treadmill, as indicated by significant Symmetry Angle reductions for contact time (p = 0.033), knee flexion (p = 0.001) and vertical speed variance (p = 0.002). The symmetry increase on the treadmill was mainly due to changes of the non-affected leg towards the affected leg values leading to smaller steps and less impact load in general. The present results suggest therefore that a) an assessment of symmetry may differ depending on the ground type (treadmill versus overground) and b) treadmill running may be more suitable for patients with KOA related gait asymmetries

Diabetes Insipidus Central: uma revisão da literatura / Central Diabetes Insipidus: a review of the literature

Introdução: O diabetes insipidus central é uma patologia que resulta do deficit de secreção de hormônio antidiurético. A principal ação desse hormônio é regular a capacidade do rim de reabsorver água, o que explica as manifestações clínicas da doença que envolvem polidipsia, noctúria e poliúria. O diagnóstico é realizado, principalmente, a partir da privação e análise da consequente concentração da urina. O tratamento, de maneira geral, consiste na administração de um análogo do hormônio deficitário a fim de controlar os sintomas, outras medicações e adequações dietéticas podem também fazer parte do tratamento. Objetivos: O objetivo desse estudo é revisar sobre o diabetes insipidus central, compreendendo epidemiologia, fisiopatologia, manifestações clinicas, diagnóstico e tratamento. Métodos: Os bancos de dados Pubmed, Diretrizes e UpToDate foram pesquisados eletronicamente utilizando os descritores diabetes insipidus central; diabetes insipidus nos idiomas inglês e português. Discussão e Conclusão: Trata-se de uma doença de manifestações clínicas sistêmicas, uma vez que a fisiopatologia envolve o equilíbrio osmótico do corpo. Distúrbios eletrolíticos podem se fazer presente em pacientes não tratados pela excreção hídrica excessiva, especificamente a hipernatremia, entretanto o próprio tratamento da doença, se não conduzido de maneira adequada, pode ocasionar distúrbios opostos, como é o caso da hiponatremia que é um dos principais efeitos colaterais da medicação mais utilizada na doença

2(CREM): une méthode de reconnaissance structurelle de documents complexes basée sur des patterns bidimensionnels

Cette thèse s'inscrit dans la problématique de la reconnaissance de documents imprimés. Nous avons étudié les systèmes existants, tout d'abord de manière générale en distinguant les systèmes de reconnaissance de la structure physique des systèmes de reconnaissance de la structure logique. Puis, nous nous sommes focalisés sur les méthodes adaptées aux documents complexes ainsi que sur les méthodes douées d’apprentissage. A la croisée de ces deux axes, nous n'avons rien trouvé et choisi d'apporter notre contribution. Des premières expériences, faisant appel à des méthodes simples, ont été appliquées pour la reconnaissance de la structure physique des pages de journaux. Elles ont permis de mettre en évidence les problèmes spécifiques à l'analyse de documents à structures complexes, en particulier le problème de l'organisation bidimensionnelle de l'information. Fort de ces constatations, nous avons conçu 2(CREM), une méthode générale de classification d'objets s'appliquant particulièrement bien à la reconnaissance des objets qui constituent un document à structure complexe. En effet, 2(CREM) est douée d'apprentissage incrémental et prévoit la description et l'interprétation d'un objet en tenant compte des deux dimensions; un objet est modélisé en une configuration, un ensemble de caractéristiques se rapportant à l'objet et à son voisinage 2D. Les configurations sont alors comparées au modèle du document analysé qui comprend, pour chaque classe d'objets, un ensemble de configurations de référence appelées patterns. L'apprentissage du modèle se fait par extension (ajout d'un pattern dans la description de la classe) et spécialisation (ajout d'une caractéristique à tous les patterns d'une classe). 2(CREM) a été implémentée puis testées dans quatre des phases de la reconnaissance d'images de journaux à la reconnaissance de filets, la reconnaissance de cadres, la fusion des lignes de texte en blocs et l'étiquetage logique des blocs de texte. Le modèle, les données et les résultats intermédiaires et finaux ont été représentés en XML. Nos expériences ont confirmé le choix de XML comme standard de représentation des données dans le domaine de la reconnaissance de documents. La méthode a été appliquée sur plusieurs exemplaires du Los Angeles Times. L'étiquetage logique a été testé sur 29 pages comprenant en tout 977 objets. Après environ 150 opérations d'étiquetage élémentaire par l'utilisateur, 86% des objets ont été classés correctement, 7% n'ont pas été reconnus, 5% étaient en conflit et 2% ont été confondus avec une autre classe. Ainsi, nous estimons avoir démontré la pertinence de 2(CREM) comme méthode de reconnaissance de structure complexes de documents qui soit douée d'apprentissage incrémental.This thesis addresses the question of printed document recognition. We studied existing systems, first in a general context, by making the distinction between physical and logical structure recognition systems. Then, we focused on methods specific for complex layout documents and on methods having a learning aptitude. Since there do not seem to exist learning systems which are able to recognise complex layout documents, we chose to work in this direction. First experiments, using simple methods, were applied for the physical structure recognition of newspaper pages. They have revealed the specific problems of the complex layout document analysis, in particular the problem of bidimensional organisation of information. With this constatation in mind, we conceived 2(CREM), a general method for object classification that is specially suited for the recognition of objects that form a complex layout document. Indeed, 2(CREM) has the ability to learn incrementally and enables the description and interpretation of an object in two dimensions; an object is modelled by a configuration, i.e. a characteristic set related to the object and to its bidimensional neighbourhood. The configurations are then compared to the analysed document model which includes, for every object class, a set of reference configurations called patterns. The system learns the model by extension (addition of a pattern to the class description) and by specialisation (addition of a characteristic to all the patterns of a class). 2(CREM) was implemented and then tested on four of the steps necessary in newspaper image recognition: the line segment recognition, the frame recognition, the merger of text lines in blocks and the logical labeling of text blocks. We represent the model, the data and the intermediate and final results by using XML. Our experience confirms the choice of XML as a standard for data representation in document recognition. The method was applied on several Los Angeles Times issues. The logical labeling has been tested on 29 pages which were composed of 977 objects in total. After around 150 elementary labeling operations by the user, 86% of the objects were correctely classified, 7% were not identified, 5% were in conflict and 2% were confused with another class. These results show that 2(CREM) is a relevant learning method for the recognition of documents with complex layout

Elaboration of a statement on the degree of generality of a property: Poincaré’s work on the recurrence theorem

This article examines the statement that a property is true for ‘almost all’ considered objects, in a precise mathematical sense, by referring to Henri Poincaré’s reflections on the generality of recurring trajectories. In 1890, Poincaré introduces a statement of a new type in which he formulates mathematically the remark that he had previously made in vague terms: ‘the trajectories that have this property [of stability, AR] are more general than those that do not’. This article first considers how Poincaré adapts the calculus of probability to show that the non-recurring trajectories are exceptional before analyzing the proofs of the recurrence theorem and the corollary that Poincaré added to the theorem. It also discusses the change of status of the recurrence theorem between 1889 and 1891 and suggests that the confinement inside the trajectory surfaces seemed to be the key property for the definition of stability.</p

Les circulations et les transferts agronomiques entre la Société économique de Berne et les sociétés d’agriculture françaises (1757-1773) : l’exemple des abeilles et de l’Encyclopédie économique

Die zweite Hälfte des achtzehnten Jahrhunderts fiel mit einer Phase der landwirtschaftlichen und demografischen Prosperität zusammen : Die gebildeten Eliten und die Aufklärung interessierten sich für die Landwirtschaft und die Agrarwissenschaft schloss sich so prestigeträchtigen Wissensgebieten wie der Mathematik und der Physik an. In diesem besonderen Kontext verbindet sich die Ökonomische Gesellschaft Bern mit einem weitreichenden Netzwerk zur Zirkulation von agronomischem Wissen und Erkenntnissen, das durch die polymorphen Netzwerke der République des Lettres begünstigt wird, insbesondere in Richtung Frankreich und Nordeuropa. Diese Studie konzentriert sich auf die agronomischen Interaktionen zwischen dem französischen und dem helvetischen Kulturraum, repräsentiert durch die Ökonomische Gesellschaft Bern: Grundlegende Konzepte, Netzwerkbildung und Vernetzung von französischen und schweizerischen Agronomen, institutionelle Unterschiede, Objekte und Medien des agronomischen Austauschs (Publikationen, Zeitschriften, Korrespondenz, Enzyklopädien), agronomische Praktiken (gemeinsame versus spezifische). Die Mechanismen (Polarisierung, Vermittlung, Ausschluss) und Prozesse (Umsetzung in die Praxis, Wiederaneignung, Zirkulation) offenbaren die Richtungen, die das Wissen eingeschlagen hat, und stellen Fragen zu einem möglichen agronomischen Kulturtransfer

An innovative PCM Storage System to enhance Building Energy Autonomy: experimental and numerical characterization

Abstract Even if the use of renewable energy sources towards autonomous buildings is promising, it is facing a fundamental issue: the shift between energy production and heating energy demand. We propose in this paper a thermally controlled storage solution using phase change materials integrated in the building walls. Its main advantage lies in the ability to activate on-demand the thermal discharge by ventilating the phase change materials. A test bench has been manufactured. Tests were performed which proved the feasibility of overnight storage with morning discharge allowing an internal air temperature increase of 5°C. Simulations based on experimental results showed that an integration in real buildings with photovoltaic energy production allows to significantly increase the building energy autonomy. If the improvement is important for all types of buildings, it showed larger absolute improvements for weakly insulated buildings than for buildings with an efficient insulation.</jats:p