Déconfiner les consciences par la systémique

The Covid-19 pandemic has affected all of humanity. It was the first time that virtually all human beings on earth felt concerned by a particular event: a Chinese allegedly ate pangolin infected with a virus, causing an epidemic that has spread to all mankind. In the case of covid 19, virtually all humans have been informed by television and the internet. This made them stand together beyond any language, race or religion. However, this shared solidarity was based on the fear of illness and death. There was nothing to counterbalance this atavistic fear, other than, for some, a faith in a particular religion. On the contrary, systemic sciences, through Cognitive and Systemic Relativity (CSR), shows that fundamentally, our consciousness is immortal because it is not subject to time; it is inspatiotemporal or eternal. It only depends on each one to awaken his social consciousness (his ego) to its dimension of eternity, which corresponds to his EGO which is the Relativist Observer, pilot of the body. In addition, this individual awakening has the advantage of functioning as a positive pandemic, based on confidence in the source of life which is the Consciousness of Existing, the root of our EGO, and therefore also of our ego. This positive pandemic is based on a particular functioning which is the systemic entanglement of all the systems on earth since the EGO of all living systems on earth are in communion at all times. The conscious restoration of this communion of all EGO through trust in our individual EGO sets in motion the healing software of all systems on earth. This corresponds to the entry of humanity into what we might call universal brotherhood and which Teilhard de Chardin calls the noosphere

Design of modified plastic surfaces for antimicrobial applications: Impact of ionizing radiation on the physical and mechanical properties of polypropylene

Surface modification of polypropylene (PP) sheets was carried out by radiation induced graft polymer- ization of hydrophilic functional molecules such as N,N-dimethylacrylamide (DMA) and [2-methacry- loyloxy)ethyl] trimethylammonium chloride, which is a quaternary ammonium salt (QAS). Polypropylene sheets were activated prior to the grafting reaction by using electron beam radiation. The changes in morphology, crystallinity and tensile parameters like deformation and stress at yield and deformation at break of PP after irradiation were investigated. The results showed that a minor crystalline reorganization takes place during the irradiation of PP at 100 kGy. The grafting has been observed to be strongly dependent on the monomer dilution in the reaction medium. After grafting of QAS (40%) and DMA (20%) it was possible to develop highly hydrophilic surfaces (water contact angle comprised between 30 and 411). The surfaces of virgin, irradiated and grafted PP were studied using polarized optical microscopy (POM) and scanning electron microscopy (SEM). Spherical particles (i.e. polystyrene or silica beads) adhering to the modified samples were studied according to the surface parameters. Adhesion tests confirmed the strong influence of substrate type (mainly hydrophilicity and roughness) and to a lesser extent underlined the role of electrostatic interactions for the design of plastic surfaces for antimicrobial applications

Faut-il réhabiliter Héron d'Alexandrie ?

International audienceIn this paper I show that the judgments about Heron of Alexandria since the XIXth c. apre built on a misinterpretation of his authentic mathematical works, on false attrbutions and derivations, on a problematic edition from the philological point of view.Dans cet article je montre que les jugements portés sur Héron d'Alexandrie depuis le XIX s. sont fondés sur une méconnaissance de son œuvre mathématique authentique, des attributions et des dérivations fautives, une édition philologiquement incertaine

The Euclidean ideal of proof in The Elements and philological uncertainties of Heiberg's edition of the text

In this chapter, I study the history of the text of Euclid's Elements including the use of the indirect medieval tradition in arabic and latin. I discuss the positions of Heiberg and Knorr. I propose a typology of the volontary alterations of Euclid's text during its transmission. Some textual criterias can be used to choice between local variants but they do not converge at the global level of an Ancient or medieval Version. The choice depends on the type of change (addition/deletion; change the order of exposition or proofs' modifications) ; it depends too of the Book or the kind of textual units concerned (Definition;Proposition;Porism;Lemma)

Thermodynamics of migration in polymers: Can contamination from materials in contact be predicted, controlled and possibly avoided?

The contamination from materials is coined as “migration” and refers to a combination of various mass transfer mechanisms under thermodynamic control: molecular or mutual diffusion, sorption and desorption phenomena linear with concentration or not. The contamination pathways are particularly complicated when they involve several components or steps and strong interactions between materials and the medium in contact. They have been studied and mathematically described with two possible purposes: i) simplified approaches with a goal of overestimating the real contamination and ii) more sophisticated approaches to optimize the design of polymer materials, packaging materials or to redesign plastic additives with lower migration risk and toxicological hazard (e.g. plasticizers, surfactant, etc.). The simplified descriptions use conventional Fick equations and proper partition rules to enable decision making – Is the contamination acceptable or not? – without requiring a perfect understanding of underlying phenomena. The approach has been chosen in EU to regulate food contact materials and is used somehow for food contact notifications in US. It has been applied to the diffusion in various polymers and is currently under extension for elastomers and varnishes. A rigorous formulation using a probabilistic resolution of transport equations provides a justification of such intuitive assumptions while minimizing both contamination levels and adverse risks (i.e. discarding falsely a good material). These theoretical results demonstrated that migration in closed systems by materials was obeying to prescribed statistical laws and that it could be managed robustly through conventional risk assessment approaches [1]. Special methodologies have been recently developed to cover the whole supply chain [2]. More sophisticated approaches seek relationships between the chemical structures of contaminants and polymers and their mass transfer properties. Several calculation procedures have been proposed and tested over the last decades including semi-empirical models, models derived from molecular thermodynamics and brute force molecular simulation [3,4]. An overview of current capabilities of prediction based on the sole chemical structure is presented. Among the most effective techniques, generalized Flory-Huggins approximations at atomistic scale enable tailored calculation of partition coefficients (or equivalently excess-chemical potentials) with reasonable accuracy for almost any contaminant, polymer or co-polymer and media in contact [5-9]. Similar breakthroughs have been proposed for diffusion coefficients based on a generalized free-volume theory [10] and solute classification [11]. Experimental and theoretical results demonstrate that adding flexible segments and symmetry axes close to the center-of-mass in additives could reduce diffusion coefficients of several magnitude orders and accordingly migration. When no data are available on the initial compositions or the identity of possible migrants, rapid deconvolution techniques have been shown to be effective for plastic materials [12,13]

May the Force Be With You: Unfolding Lipid-Protein Interactions By Single-Molecule Force Spectroscopy

In this issue of Structure, Serdiuk et al. report the use of single-molecule force microscopy to establish a role for phosphatidylethanolamine in promoting the native fold of lactose permease, thereby preventing it from populating a functionally defective, nonnative conformation (Serdiuk et al., 2015)

The ubiquitous issue of cross-mass transfer: applications to single-use systems

The leaching of chemicals by materials has been integrated into risk management procedures of many sectors where hygiene and safety are important, including food, medical, pharmaceutical, and biotechnological applications. The approaches focus on direct contact and do not usually address the risk of cross-mass transfer of chemicals from one item or object to another and finally to the contacting phase (e.g., culture medium, biological fluids). Overpackaging systems, as well as secondary or ternary containers, are potentially large reservoirs of non-intentionally added substances (NIAS), which can affect the final risk of contamination. This study provides a comprehensive description of the cross-mass transfer phenomena for single-use bags along the chain of value and the methodology to evaluate them numerically on laminated and assembled systems. The methodology is validated on the risk of migration i) of -caprolactam originating from the polyamide 6 internal layer of the overpackaging and ii) of nine surrogate migrants with various volatilities and polarities. The effects of imperfect contacts between items and of an air gap between them are particularly discussed and interpreted as a cutoff distance depending on the considered substance. A probabilistic description is suggested to define conservative safety-margins required to manage cross-contamination and NIAS in routine

Héron d'Alexandrie et le corpus métrologique : état des lieux

Il s'agit d'un document composé pour le Séminaire d'histoire des mathématiques de Lille (UMR 8163 « Savoirs, textes, langage » CNRS/Universités de Lille et UMR 8210 « ANHIMA », Paris) organisé par F. Acerbi et moi-même, texte revu et modifié pour les Journées d'études « Géométrie(s), pratiques d'arpentage et enseignement : quels liens et dans quel contexte ? » organisées par Alain Bernard et Christine Proust les 15-16 Mars 2010 à Paris.International audienceIn this survey of the heronian and pseudo heronian corpus, I examine the following points : • Works attributed to Heron of Alexandria • The metrological corpus : editions; manuscripts • Collections of problems reconstructed by J.L. Heiberg (Teubner edition) • A chronology of the metrological corpus from an historiographical point of view • Authenticity • Relationships between Metrica (authentic heronian treatise) and the other writings in the corpus. Nine appendices are added to the text which include some informations about the known manuscripts, the content of the most important manuscripts, the content and the structure of the collections reconstructed by J.L. Heiberg (Geometrica, Stereometrica I, Stereometrica II), titles, authors and works mentionned in the manuscripts.Dans cet état des lieux du corpus métrologique héronien et pseudo héronien, j'aborde les points suivants : • Oeuvres attribuées à Héron d'Alexandrie • Le corpus métrologique : éditions; traditions manuscrites • Les collections de problèmes reconstituées par J.L. Heiberg (édition Teubner) • Chronologie du corpus métrologique du point de vue historiographique • Discussion d'authenticité • Relations entre les Métriques (traité héronien authentique) et les autres écrits du corpus. Neuf annexes ont été jointes au texte qui comprennent différentes informations sur les manuscrits recensés, le contenu des principaux d'entre eux, le contenu et la structure des collections reconstituées par J.L. Heiberg (Geometrica, Stereometrica I, Stereometrica II), la liste des titres, intertitres, personnages ou écrits cités dans les manuscrits