The study of the autonomic nervous system (ANS) function has shown to provide useful indicators for risk stratification and early detection on a variety of cardiovascular pathologies. However, data gathered during different tests of the ANS are difficult to analyse, mainly due to the complex mechanisms involved in the autonomic regulation of the cardiovascular system (CVS). Although model-based analysis of ANS data has been already proposed as a way to cope with this complexity, only a few models coupling the main (...) elements involved have been presented in the literature. In this paper, a new model of the CVS, representing the ventricles, the circulatory system and the regulation of the CVS activity by the ANS, is presented. The models of the vascular system and the ventricular activity have been developed using the Bond Graph formalism, as it proposes a unified representation for all energetic domains, facilitating the integration of mechanic and hydraulic phenomena. In order to take into account the electro-mechanical behaviour of both ventricles, an electrophysiologic model of the cardiac action potential, represented by a set of ordinary differential equations, has been integrated. The short-term ANS regulation of heart rate, cardiac contractility and peripheral vasoconstriction is represented by means of continuous transfer functions. These models, represented in different continuous formalisms, are coupled by using a multi-formalism simulation library. Results are presented for two different autonomic tests, namely the Tilt Test and the Valsalva Manoeuvre, by comparing real and simulated signals. (shrink)

In this paper, a mathematical model of the respiratory mechanics is used to reproduce experimental signal waveforms acquired from three newborn lambs. As the main challenge is to determine specific lamb parameters, a sensitivity analysis has been realized to find the most influent parameters, which are identified using an evolutionary algorithm. Results show a close match between experimental and simulated pressure and flow waveforms obtained during spontaneous ventilation and pleural pressure variations acquired during the application of positive pressure, since root (...) mean square errors equal to 0.0119, 0.0052 and 0.0094. The identified parameters were discussed in light of previous knowledge of respiratory mechanics in the newborn. (shrink)

The ventricular pressure profile is characteristic of the cardiac contraction progress and is useful to evaluate the cardiac performance. In this contribution, a tissue-level electromechanical model of the left ventricle is proposed, to assist the interpretation of left ventricular pressure waveforms. The left ventricle has been modeled as an ellipsoid composed of twelve mechano-hydraulic sub-systems. The asynchronous contraction of these twelve myocardial segments has been represented in order to reproduce a realistic pressure profiles. To take into account the different energy (...) domains involved, the tissue-level scale and to facilitate the building of a modular model, multiple formalisms have been used: Bond Graph formalism for the mechano-hydraulic aspects and cellular automata for the electrical activation. An experimental protocol has been defined to acquire ventricular pressure signals from three pigs, with different afterload conditions. Evolutionary Algorithms have been used to identify the model parameters in order to minimize the error between experimental and simulated ventricular pressure signals. Simulation results show that the model is able to reproduce experimental ventricular pressure. In addition, electro-mechanical activation times have been determined in the identification process. For example, the maximum electrical activation time is reached, respectively, 96.5, 139.3 and 131.5 ms for the first, second, and third pigs. These preliminary results are encouraging for the application of the model on non-invasive data like ECG, arterial pressure or myocardial strain. (shrink)

The objective of the current study was to propose a sensitivity analysis of a 3D left ventricle model in order to assess the influence of parameters on myocardial mechanical dispersion. A finite element model of LV electro-mechanical activity was proposed and a screening method was used to evaluate the sensitivity of model parameters on the standard deviation of time to peak strain. Results highlight the importance of propagation parameters associated with septal and lateral segments activation. Simulated curves were compared to (...) myocardial strains, obtained from echocardiography of one healthy subject and one patient diagnosed with intraventricular dyssynchrony and coronary artery disease. Results show a close match between simulation and clinical strains and illustrate the model ability to reproduce myocardial strains in the context of intraventricular dyssynchrony. (shrink)

A method for the recursive identification of physiological models of the cardiovascular baroreflex is proposed and applied to the time-varying analysis of vagal and sympathetic activities. The proposed method was evaluated with data from five newborn lambs, which were acquired during injection of vasodilator and vasoconstrictors and the results show a close match between experimental and simulated signals. The model-based estimation of vagal and sympathetic contributions were consistent with physiological knowledge and the obtained estimators of vagal and sympathetic activities were (...) compared to traditional markers associated with baroreflex sensitivity. High correlations were observed between traditional markers and model-based indices. (shrink)

The study of the autonomic nervous system (ANS) function has shown to provide useful indicators for risk stratification and early detection on a variety of cardiovascular pathologies. However, data gathered during different tests of the ANS are difficult to analyse, mainly due to the complex mechanisms involved in the autonomic regulation of the cardiovascular system (CVS). Although model-based analysis of ANS data has been already proposed as a way to cope with this complexity, only a few models coupling the main (...) elements involved have been presented in the literature. In this paper, a new model of the CVS, representing the ventricles, the circulatory system and the regulation of the CVS activity by the ANS, is presented. The models of the vascular system and the ventricular activity have been developed using the Bond Graph formalism, as it proposes a unified representation for all energetic domains, facilitating the integration of mechanic and hydraulic phenomena. In order to take into account the electro-mechanical behaviour of both ventricles, an electrophysiologic model of the cardiac action potential, represented by a set of ordinary differential equations, has been integrated. The short-term ANS regulation of heart rate, cardiac contractility and peripheral vasoconstriction is represented by means of continuous transfer functions. These models, represented in different continuous formalisms, are coupled by using a multi-formalism simulation library. Results are presented for two different autonomic tests, namely the Tilt Test and the Valsalva Manoeuvre, by comparing real and simulated signals. (shrink)

The study of the autonomic nervous system (ANS) function has shown to provide useful indicators for risk stratification and early detection on a variety of cardiovascular pathologies. However, data gathered during different tests of the ANS are difficult to analyse, mainly due to the complex mechanisms involved in the autonomic regulation of the cardiovascular system (CVS). Although model-based analysis of ANS data has been already proposed as a way to cope with this complexity, only a few models coupling the main (...) elements involved have been presented in the literature. In this paper, a new model of the CVS, representing the ventricles, the circulatory system and the regulation of the CVS activity by the ANS, is presented. The models of the vascular system and the ventricular activity have been developed using the Bond Graph formalism, as it proposes a unified representation for all energetic domains, facilitating the integration of mechanic and hydraulic phenomena. In order to take into account the electro-mechanical behaviour of both ventricles, an electrophysiologic model of the cardiac action potential, represented by a set of ordinary differential equations, has been integrated. The short-term ANS regulation of heart rate, cardiac contractility and peripheral vasoconstriction is represented by means of continuous transfer functions. These models, represented in different continuous formalisms, are coupled by using a multi-formalism simulation library. Results are presented for two different autonomic tests, namely the Tilt Test and the Valsalva Manoeuvre, by comparing real and simulated signals. (shrink)

The European Union Commission’s whitepaper on Artificial Intelligence proposes shaping the emerging AI market so that it better reflects common European values. It is a master plan that builds upon the EU AI High-Level Expert Group guidelines. This article reviews the masterplan, from a culture cycle perspective, to reflect on its potential clashes with current societal, technical, and methodological constraints. We identify two main obstacles in the implementation of this plan: the lack of a coherent EU vision to drive future (...) decision-making processes at state and local levels and the lack of methods to support a sustainable diffusion of AI in our society. The lack of a coherent vision stems from not considering societal differences across the EU member states. We suggest that these differences may lead to a fractured market and an AI crisis in which different members of the EU will adopt nation-centric strategies to exploit AI, thus preventing the development of a frictionless market as envisaged by the EU. Moreover, the Commission aims at changing the AI development culture proposing a human-centred and safety-first perspective that is not supported by methodological advancements, thus taking the risks of unforeseen social and societal impacts of AI. We discuss potential societal, technical, and methodological gaps that should be filled to avoid the risks of developing AI systems at the expense of society. Our analysis results in the recommendation that the EU regulators and policymakers consider how to complement the EC programme with rules and compensatory mechanisms to avoid market fragmentation due to local and global ambitions. Moreover, regulators should go beyond the human-centred approach establishing a research agenda seeking answers to the technical and methodological open questions regarding the development and assessment of human-AI co-action aiming for a sustainable AI diffusion in the society. (shrink)

This paper focuses on flows to emerging capital markets (ECMs) and examines the importance of corporate transparency and public governance in attracting portfolio flows to ECMs. This paper's empirical investigation centers on the hypothesis that ceteris paribus, ECMs with better quality accounting standards and good governance attract higher levels of portfolio equity and bond flows. To assess the incremental impact of each of these factors, a pooled time series, cross‐sectional model was econometrically tested for 17 ECMS over the 1998–2002 time (...) period. Our empirical analysis demonstrates a positive association between public governance, corporate transparency, and portfolio flows after controlling for other macroeconomic factors. The results suggest that good public governance and high accounting quality are important determinants of portfolio flows to ECMs. Finally, the paper establishes that while portfolio equity flows are significantly attracted to ECMs with strong democratic institutions, there is no significant association between portfolio bond flows and the presence of democratic institutions. (shrink)

L’aphorisme sur lequel s’ouvre la préface du livre : « Tant vaut la femme, tant vaut la famille et la société » retrace parfaitement le rôle que la société du XIXe siècle entend accorder aux femmes. Se comporter en ménagères chevronnées, en femmes de foyer expertes en sciences domestiques, en maîtresses de maison économes, en un mot en « fées du logis » est la première des tâches qui leur incombent. C’est cet éloge de la ménagère œuvrant au bien-être de (...) son foyer et de la nation toute entière... (shrink)

Dans cet article, je montre que les neurosciences computationnelles fournissent une nouvelle approche pertinente à des problèmes traditionnels en philosophie tels que la relation entre les états mentaux et cérébraux (le problème esprit–corps ou corps–esprit), le déterminisme et le libre arbitre, et peut nous aider à traiter le problème « difficile » des aspects phénoménaux de la conscience. Un des thèmes de cet article et de mon livre Neuroculture: on the Implications of Brain Science ([Rolls 2012c]) est qu’en comprenant les (...) calculs effectués par les neurones et les réseaux neuronaux, et les effets du bruit dans le cerveau sur ceux-ci, nous gagnerons une vraie compréhension des mécanismes qui sous-tendent le fonctionnement du cerveau. Une partie de notre solution au problème esprit–corps est que l’esprit et le cerveau sont différents niveaux d’explication du traitement de l’information, leur relation pouvant être appréhendée par la compréhension des mécanismes en jeu à l’aide de l’approche fournie par les neurosciences computationnelles. Mais cette solution ne traite pas certains problèmes « difficiles » tels que le problème de la conscience phénoménale, et, même si j’ai fourni de nouvelles suggestions sur ce point dans cet article, il faut reconnaître qu’il y a toujours une brèche dans notre compréhension entre les événements dans le cerveau et les expériences subjectives qui peuvent les accompagner. L’explication que je propose est que, lorsque cela « fait quelque chose », il ne s’agit que d’une propriété d’un processus computationnel qui a des pensées sur ses propres pensées (pensées d’ordre supérieur), les pensées étant ancrées dans le monde. (shrink)

Dans cet article, je montre que les neurosciences computationnelles fournissent une nouvelle approche pertinente à des problèmes traditionnels en philosophie tels que la relation entre les états mentaux et cérébraux (le problème esprit–corps ou corps–esprit), le déterminisme et le libre arbitre, et peut nous aider à traiter le problème « difficile » des aspects phénoménaux de la conscience. Un des thèmes de cet article et de mon livre Neuroculture: on the Implications of Brain Science ([Rolls 2012c]) est qu’en comprenant les (...) calculs effectués par les neurones et les réseaux neuronaux, et les effets du bruit dans le cerveau sur ceux-ci, nous gagnerons une vraie compréhension des mécanismes qui sous-tendent le fonctionnement du cerveau. Une partie de notre solution au problème esprit–corps est que l’esprit et le cerveau sont différents niveaux d’explication du traitement de l’information, leur relation pouvant être appréhendée par la compréhension des mécanismes en jeu à l’aide de l’approche fournie par les neurosciences computationnelles. Mais cette solution ne traite pas certains problèmes « difficiles » tels que le problème de la conscience phénoménale, et, même si j’ai fourni de nouvelles suggestions sur ce point dans cet article, il faut reconnaître qu’il y a toujours une brèche dans notre compréhension entre les événements dans le cerveau et les expériences subjectives qui peuvent les accompagner. L’explication que je propose est que, lorsque cela « fait quelque chose », il ne s’agit que d’une propriété d’un processus computationnel qui a des pensées sur ses propres pensées (pensées d’ordre supérieur), les pensées étant ancrées dans le monde. (shrink)

This paper demonstrates that L'Étranger , Camus's famous novel about an outsider, had by as early as 1946 become just as much of an 'insider' in terms of its affiliation to the Parisian literary tradition. More than an insider simply by virtue of its contemporary place in the French canon, then, the novel is also intertextually bound to a tradition of oxymoronic poetics dating back to Charles Baudelaire's Paris Spleen ( Les Petits poèmes en prose ). I shall examine the (...) way in which L'Étranger performs its prose poetics, thereby establishing it as exemplary of a Parisian model of modernity. Additionally, the famous scene on the beach will be considered as a liminal space and as a literary translation of Paris into the desert, which, once a joke for Paris's relationship to provincial France, became after the Second World War a new allegory for the capital's self-alterity. (shrink)

Petite fille d’Olympe Gevin-Cassal (1859-1945), Geneviève Lefort nous fait découvrir dans cet ouvrage le parcours et les multiples engagements de sa grand-mère qui contribua à la mise en place de réformes en faveur de la protection des mères et de leurs enfants. Ce récit détaillé s’appuie essentiellement sur les souvenirs de l’auteure, de riches archives familiales longtemps oubliées comprenant de nombreuses lettres, notes manuscrites, extraits de journaux, actes d’état civil etc., et les rap...

Voici un ouvrage qui contribue à combler un vide dans l’histoire de l’éducation et l’histoire des femmes. Joël Lebeaume retrace ici l’évolution complexe d’un enseignement souvent considéré à tort, aujourd’hui encore, comme une entreprise de moralisation des femmes. Les cours de ménage, de blanchissage, de cuisine, de puériculture etc. qui accompagnent le siècle forment certes les élèves aux activités domestiques, de couture, de nettoyage, de soins et aux préparations culinaires qu’elles exerc...