Lorenz-like systems and classical dynamical equations with memory forcing: a new point of view for singling out the origin of chaos

A novel view for the emergence of chaos in Lorenz-like systems is presented. For such purpose, the Lorenz problem is reformulated in a classical mechanical form and it turns out to be equivalent to the problem of a damped and forced one dimensional motion of a particle in a two-well potential, with a forcing term depending on the ``memory'' of the particle past motion. The dynamics of the original Lorenz system in the new particle phase space can then be rewritten in terms of an one-dimensional first-exit-time problem. The emergence of chaos turns out to be due to the discontinuous solutions of the transcendental equation ruling the time for the particle to cross the intermediate potential wall. The whole problem is tackled analytically deriving a piecewise linearized Lorenz-like system which preserves all the essential properties of the original model.Comment: 48 pages, 25 figure

Pursuing resilience in architectural design through international experimental projects: exploring new boundaries in the design studio pedagogy.

In response to the current global crisis, there is a growing demand for responsible behaviour in designing and building that can accommodate user needs through the design process. This chapter describes an innovative approach to the design process aiming to generate a model adopted by an international collaboration who are reconsidering the traditional design process and addressing a new paradigm of the thinking process. The project is experimental in nature and discusses the educational frameworks in architecture. It optimises a model, which demonstrates breakthroughs and trend-setting educational approaches and is potentially transferable to a range of other professions. The chapter argues that the educational ethos of ‘ethic of resilience’ should be pursued by pushing the boundaries of the conventional Design Studio towards the formation of adaptive system settings. All the participants at the various stages of the innovative educational framework, named Build Our Nation (BON) and its first application Taifa Letu Tujenge (TLT), have already demonstrated, on one hand to be able to learn from the experience achieved from various stages undertaken in the past, and, on the contrary, to be flexible enough to proceed with changes reflecting on the external conditions. The vision is that the Higher Educational Institutions and, especially, universities must become more co-productive actors in society. It can be useful to think of a university as a manufacturer; and subsequently, a manufacturing company as an advanced workshop; a workshop as a real-world project; therefore, a real-world project connoted back to the meaning of university. This vicious cycle of pedagogy embedded in learning and teaching should be central to any higher education focusing on design and research aiming to inform each other through the values of social capital

Ovarian cancer molecular pathology.

Peer reviewe

Training programs for children: literature review

International audienc

Training programs for children: literature review

International audienc

Étude des relations entre le score de Gillette et la vitesse de marche chez les enfants paralysés cérébraux

Contexte Aider les enfants atteints de paralysie cérébrale à découvrir, puis à perfectionner leurs possibilités de déplacement et de déambulation, est un des buts essentiels de l'action thérapeutique. Cela implique une connaissance approfondie de leurs capacités de marche. Le but de cette étude était d'essayer de trouver un ou des paramètres spatiotemporels du pattern de marche corrélé au score de Gillette afin de disposer d'un outil objectif d'évaluation des capacités de marche de l'enfant paralysé cérébral. Méthode Cinq sujets âgés de 6 à 14 ans (± 4,4), répondant aux classes 1 à 3 du score de Palisano ont été inclus dans l'étude. Une évaluation des qualités de marche par l'échelle de Gillette a été réalisée à la suite d'une évaluation des paramètres spatiotemporels de marche sur un tapis de type GAITRite®. Résultats Ainsi cinq paramètres spatiotemporels corrélés au score de Gillette ont été mis en évidence. Tous ces paramètres sont liés à la vitesse de déplacement. Discussion Les résultats montrent une corrélation des paramètres liés à la vitesse de foulée et du pas des patients. Les paramètres concernant la foulée et le pas des enfants paralysés cérébraux sont à prendre en compte dans le processus de prise en charge rééducative. Conclusion Une étude future devra comprendre un plus grand nombre de sujets et centrer son investigation sur les paramètres corrélés

Energy and information in Hodgkin-Huxley neurons

The generation of spikes by neurons is energetically a costly process and the evaluation of the metabolic energy required to maintain the signalling activity of neurons a challenge of practical interest. Neuron models are frequently used to represent the dynamics of real neurons but hardly ever to evaluate the electrochemical energy required to maintain that dynamics. This paper discusses the interpretation of a Hodgkin-Huxley circuit as an energy model for real biological neurons and uses it to evaluate the consumption of metabolic energy in the transmission of information between neurons coupled by electrical synapses, i.e. gap junctions. We show that for a single postsynaptic neuron maximum energy efficiency, measured in bits of mutual information per ATP molecule consumed, requires maximum energy consumption. On the contrary, for groups of parallel postsynaptic neurons we determine values of the synaptic conductance at which the energy efficiency of the transmission presents clear maxima at relatively very low values of metabolic energy consumption. Contrary to what it could be expected best performance occurs at low energy cost.Comment: This paper has been withdrawn by the author due to technical issue

Efficiency of flexible derotator in walking cerebral palsy children

Introduction The flexible derotator is one of the therapeutic resources used to combat primary and secondary abnormalities in walking cerebral palsy children. It was developed to reduce abnormal femoral and tibial torsions and lessen the latter's negative functional impact. Objective To determine the effect of wearing a flexible derotator on anatomic and functional parameters in walking cerebral palsy children. Methods We performed a retrospective study of walking cerebral palsy children by gathering data on bone-related parameters (femoral and tibial torsion) and functional parameters (distance and speed gait, and the energy expenditure index (EEI)). Fifteen walking cerebral palsy children were treated with the flexible derotator for one year and 15 untreated walking cerebral palsy children were included as controls. The two groups were compared in terms of the various parameters' change over time between the initial examination (the last examination prior to the start of the study or prior to use of the flexible derotator) and the final examination (after one year of follow-up). Results Right femoral anteversion and right and left external tibial torsion improved. There was a significant increase in distance and speed gait and a decrease in the EEI in walking cerebral palsy children. Conclusion Our retrospective study revealed a significant improvement in functional parameters in children with cerebral palsy, as a result of wearing the flexible derotator for at least 6 hours a day for a year. Bone parameters only improved slightly. Use of the flexible derotator could improve these children's quality of life