Exemple d’acquisition automatique de mesures sur une maquette de contrôle actif de vibrations

Cet article propose une séance pédagogique autour de la mesure via une carte d'acquisition National Instruments interfacée avec Matlab. Cette séance a été montée pour répondre à une demande des étudiants qui, au cours de la scolarité et en particulier lors de la réalisation de projets, ont besoin d'effectuer des campagnes de mesures. Afin d'illustrer les manipulations réalisables avec la carte, le matériel et les programmes d'acquisition et de traitement de l'information sont mis en oeuvre sur une application de contrôle actif de vibrations, permettant ainsi d'effectuer des mesures dynamiques dans les domaines temporel et fréquentiel

Instrumentation d’une Fusée à Eau

Dans le cadre de la formation ISAE-ENSICA, un projet pédagogique autour du concept de fusée à eau a été développé. Cette fusée à eau est en fait instrumentée pour permettre l’analyse des différents paramètres de vol : accélération, vitesse et altitude en fonction du temps. Ce projet, d’un volume de 15 heures semi-encadrées, s’adresse à des étudiants d’un niveau Licence ou première année Master. En complément de la validation des notions d’électronique analogique, il permet par la même occasion d’aborder d’un point de vue pratique les principes théoriques d’aérodynamique et de mécanique du vol pour les lanceurs spatiaux. Outre l’aspect ludique évident, ce projet fait clairement apparaître les liens entre les différentes disciplines scientifiques qui constituent l’enseignement pluridisciplinaire de la formation ISAE-ENSICA

The Sorcerer’s cave in Saint-Cirq-du-Bugue (Dordogne, France): new readings. Report of the 2010 and 2011 campaigns

Two main reasons have led us to start again the study of the Sorcerer’s cave in Saint-Cirq-du-Bugue (Dordogne): first of all the real progress existing in recent years in the means available for the study of prehistoric parietal art, which had not been applied to the site; and secondly the discovery of vandalism on some of the art, which needed to be assessed precisely. The new campaign of tracings, as well as the attention given to understanding the making of the engravings in connection with the underground relief shapes allowed a better apprehension of the artists’ environment at the time of the making of the works of art, together with a more precise idea of the gestures and techniques used. Furthermore, during our first campaign in the autumn 2010, we were able to carry out a full topographic coverage of the cave associated with a precise sizing of all the engravings, in view of the future making of a digital site model. On most of the engravings studied up to date, it was possible to precise some of the ancient lines, to identify the position of the modern lines and to record the effects of the degradation agents associated to a rock support that is especially fragile in places. The main figure of the cave, the human ithyphallic figure, was newly interpreted (especially its head), which allowed us to underline the engraving of an equine whose back leg is partially superimposed to the engraving of the Sorcerer’s sex. The new engraving of a horse, up to date unnoticed, was also discovered. Finally, in the course of our investigations, it appeared essential to study the whole of the engravings as belonging to one composition stretched around a large fissure on the vault ‒ showing how important the natural shapes of the rock surfaces are in the organisation of the representations ‒ as well as to rethink the making of the decoration as the superimposition of drawings from different time periods

Mosquito magnet® liberty plus trap baited with octenol confirmed best candidate for Anopheles surveillance and proved promising in predicting risk of malaria transmission in French Guiana

BACKGROUND: In French Guiana, Mosquito Magnet(®) Liberty Plus trap baited with octenol (MMoct) has been proposed for sampling Anopheles darlingi after comparison with CDC light trap and Human landing catch (HLC). However, other available lures were not tested. The current study compared MMoct and MM baited with Lurex™ (MMlur) to HLC, and analysed entomological data from MMoct collection with malaria cases to facilitate malaria surveillance. METHODS: Two independent experiments were conducted during 2012 and 2013 in Saint-Georges town, French Guiana. The first experiment used Latin square design to compare MMoct and MMlur to HLC between 18:30 to 22:30 and 05:00 to 07:00. Parity rate was determined for An. darlingi from each sampling system. In the second experiment, a 24:00 hour collection was done for four consecutive days during the first week of each month and every four days for the rest of the month using MMoct. Portion of the 24 hour collection was dissected for parity rate. All anophelines were screened for Plasmodium infection by PCR. Data for number of malaria cases was analysed for association with density of An. darlingi. RESULTS: In the first experiment, 3,721 anopheline mosquitoes were collected over 21 nights. Of these, 95.7% was identified morphologically to five species and An. darlingi contributed 98.4%, mainly from HLC (75.1%, CI 95% [73.2-77.0]) than MMoct (14.1%, CI 95% [12.6-15.7]) and MMlur (10.8%, CI 95% [9.4-12.2]). Species richness was highest in HLC meanwhile species diversity index was greatest in MMoct. MMoct collected more parous An. darlingi than HLC (p < 0.0001) and MMlur (p = 0.0021). The second experiment amounted to 2035 females, 60.8% belonging to 10 species. Anopheles darlingi constituted 85.0% of the species and had parity rate of 52.3%. Specimens were uninfected with Plasmodium. Density of An. darlingi best correlated with malaria cases observed six weeks later (p = 0.0016; r = 0.4774). CONCLUSION: Though MMoct and MMlur performed well in sampling An. darlingi, MMoct captured more species and, therefore, would be useful for surveillance. Even if it collected mostly parous mosquitoes, MMoct proved useful in collecting entomological data required for predicting malaria emergence. It is a potential replacement for HLC

The Sorcerer’s cave in Saint-Cirq-du-Bugue (Dordogne, France): new readings. Report of the 2010 and 2011 campaigns

Two main reasons have led us to start again the study of the Sorcerer’s cave in Saint-Cirq-du-Bugue (Dordogne): first of all the real progress existing in recent years in the means available for the study of prehistoric parietal art, which had not been applied to the site; and secondly the discovery of vandalism on some of the art, which needed to be assessed precisely. The new campaign of tracings, as well as the attention given to understanding the making of the engravings in connection with the underground relief shapes allowed a better apprehension of the artists’ environment at the time of the making of the works of art, together with a more precise idea of the gestures and techniques used. Furthermore, during our first campaign in the autumn 2010, we were able to carry out a full topographic coverage of the cave associated with a precise sizing of all the engravings, in view of the future making of a digital site model. On most of the engravings studied up to date, it was possible to precise some of the ancient lines, to identify the position of the modern lines and to record the effects of the degradation agents associated to a rock support that is especially fragile in places. The main figure of the cave, the human ithyphallic figure, was newly interpreted (especially its head), which allowed us to underline the engraving of an equine whose back leg is partially superimposed to the engraving of the Sorcerer’s sex. The new engraving of a horse, up to date unnoticed, was also discovered. Finally, in the course of our investigations, it appeared essential to study the whole of the engravings as belonging to one composition stretched around a large fissure on the vault ‒ showing how important the natural shapes of the rock surfaces are in the organisation of the representations ‒ as well as to rethink the making of the decoration as the superimposition of drawings from different time periods

La grotte du sorcier à Saint-Cirq-du-Bugue (Dordogne, France) : nouvelles lectures. Bilan des campagnes 2010 et 2011

Les progrès réalisés ces dernières années dans les moyens mis à disposition pour étudier l’art pariétal préhistorique, ainsi que l’amer constat d’actes de vandalisme opérés sur certaines gravures de la grotte du Sorcier à Saint-Cirq-du-Bugue (Dordogne), nous ont conduits à reprendre l’étude de ce site majeur de l’art aquitain des populations de chasseurs-collecteurs. Cette nouvelle campagne de relevés, ainsi que l’attachement à comprendre l’exécution des gravures en lien avec les formes de relief souterrain, nous permettent de mieux appréhender l’environnement physique de la grotte au moment de la réalisation des œuvres, tout en nous faisant une idée plus précise des gestes et des techniques employés. Par ailleurs, nous avons pu réaliser lors de la première campagne, menée à l’automne 2010, la couverture topographique complète de la cavité associée à la cotation précise de l’ensemble des représentations, en vue de la réalisation future d’un modèle numérique de terrain.Sur la plupart des gravures réexaminées jusqu’alors, il nous a été possible de préciser certains tracés anciens, d’identifier la position des ajouts modernes et de constater les effets des altéragènes, associés à un support rocheux par endroits particulièrement vulnérable. La figure maîtresse de la grotte, cette représentation humaine ithyphallique, a fait l’objet d’une nouvelle lecture (notamment de la tête), qui a mis en évidence la gravure d’un équidé dont l’une des jambes arrière se superpose pour partie avec le tracé du sexe du « Sorcier ». Une nouvelle gravure figurant un équidé, jusque-là passée inaperçue, a également été découverte. Enfin, au fur et à mesure de nos investigations, il nous est apparu essentiel d’étudier l’ensemble des gravures comme appartenant à une composition se développant autour d’une large fissure présente à la voûte – signe de l’importance des formes naturelles des parois dans l’articulation des représentations –, ainsi que de repenser la constitution de son décor comme la superposition de tracés de différentes époques.Recent-years progress in the means available for the study of prehistoric parietal art as well as the bitter acknowledgement of vandalism on some engravings of the Sorcerer’s cave in Saint-Cirq-du-Bugue (Dordogne) led us to start again the study of this major site for the art of the hunters-gatherers of Aquitaine. The new campaign of tracings, as well as the attention given to understanding the making of the engravings in connection with the underground relief shapes allowed a better apprehension of the artists’ environment at the time of the making of the works of art, together with a more precise idea of the gestures and techniques used. Furthermore, during our first campaign in the autumn 2010, we were able to carry out a full topographic coverage of the cave associated with a precise sizing of all the engravings, in view of the future making of a numeric site model. On most of the studied engravings up to date, it was possible to precise some of the ancient lines, to identify the position of the modern lines and to record the effects of the degradation agents associated to a rock support that is especially fragile in places. The main figure of the cave, the human ithyphallic figure, was read anew (especially its head) which allowed us underlining the engraving of an equine whose back leg is partly superimposed to the engraving of the Sorcerer’s sex. The new engraving of a horse, up to date unnoticed, was also discovered. Finally, in the course of our investigations, it appeared essential to us to study the whole of the engravings as belonging to one composition stretched around a large crack on the vault - showing how important the natural shapes of the rock surfaces are in the organisation of the representations - as well as to rethink the making of the decoration as the superimposition of lines from different time periods

La grotte du sorcier à Saint-Cirq-du-Bugue (Dordogne, France) : nouvelles lectures. Bilan des campagnes 2010 et 2011

Les progrès réalisés ces dernières années dans les moyens mis à disposition pour étudier l’art pariétal préhistorique, ainsi que l’amer constat d’actes de vandalisme opérés sur certaines gravures de la grotte du Sorcier à Saint-Cirq-du-Bugue (Dordogne), nous ont conduits à reprendre l’étude de ce site majeur de l’art aquitain des populations de chasseurs-collecteurs. Cette nouvelle campagne de relevés, ainsi que l’attachement à comprendre l’exécution des gravures en lien avec les formes de relief souterrain, nous permettent de mieux appréhender l’environnement physique de la grotte au moment de la réalisation des œuvres, tout en nous faisant une idée plus précise des gestes et des techniques employés. Par ailleurs, nous avons pu réaliser lors de la première campagne, menée à l’automne 2010, la couverture topographique complète de la cavité associée à la cotation précise de l’ensemble des représentations, en vue de la réalisation future d’un modèle numérique de terrain.Sur la plupart des gravures réexaminées jusqu’alors, il nous a été possible de préciser certains tracés anciens, d’identifier la position des ajouts modernes et de constater les effets des altéragènes, associés à un support rocheux par endroits particulièrement vulnérable. La figure maîtresse de la grotte, cette représentation humaine ithyphallique, a fait l’objet d’une nouvelle lecture (notamment de la tête), qui a mis en évidence la gravure d’un équidé dont l’une des jambes arrière se superpose pour partie avec le tracé du sexe du « Sorcier ». Une nouvelle gravure figurant un équidé, jusque-là passée inaperçue, a également été découverte. Enfin, au fur et à mesure de nos investigations, il nous est apparu essentiel d’étudier l’ensemble des gravures comme appartenant à une composition se développant autour d’une large fissure présente à la voûte – signe de l’importance des formes naturelles des parois dans l’articulation des représentations –, ainsi que de repenser la constitution de son décor comme la superposition de tracés de différentes époques.Recent-years progress in the means available for the study of prehistoric parietal art as well as the bitter acknowledgement of vandalism on some engravings of the Sorcerer’s cave in Saint-Cirq-du-Bugue (Dordogne) led us to start again the study of this major site for the art of the hunters-gatherers of Aquitaine. The new campaign of tracings, as well as the attention given to understanding the making of the engravings in connection with the underground relief shapes allowed a better apprehension of the artists’ environment at the time of the making of the works of art, together with a more precise idea of the gestures and techniques used. Furthermore, during our first campaign in the autumn 2010, we were able to carry out a full topographic coverage of the cave associated with a precise sizing of all the engravings, in view of the future making of a numeric site model. On most of the studied engravings up to date, it was possible to precise some of the ancient lines, to identify the position of the modern lines and to record the effects of the degradation agents associated to a rock support that is especially fragile in places. The main figure of the cave, the human ithyphallic figure, was read anew (especially its head) which allowed us underlining the engraving of an equine whose back leg is partly superimposed to the engraving of the Sorcerer’s sex. The new engraving of a horse, up to date unnoticed, was also discovered. Finally, in the course of our investigations, it appeared essential to us to study the whole of the engravings as belonging to one composition stretched around a large crack on the vault - showing how important the natural shapes of the rock surfaces are in the organisation of the representations - as well as to rethink the making of the decoration as the superimposition of lines from different time periods

4-Pregnen-21-ol-3,20-dione-21-(4-bromobenzenesulfonate) (NSC 88915) and related novel steroid derivatives as tyrosyl-DNA phosphodiesterase (Tdp1) inhibitors

Tyrosyl-DNA phosphodiesterase 1 (Tdp1) is an enzyme that catalyzes the hydrolysis of 3'-phosphotyrosyl bonds. Such linkages form in vivo when topoisomerase I (Top1) processes DNA. For this reason, Tdp1 has been implicated in the repair of irreversible Top1-DNA covalent complexes. Tdp1 inhibitors have been regarded as potential therapeutics in combination with Top1 inhibitors, such as the camptothecin derivatives, topotecan and irinotecan, which are used to treat human cancers. Using a novel high-throughput screening assay, we have identified the C21-substituted progesterone derivative, NSC 88915 (1), as a potential Tdp1 inhibitor. Secondary screening and cross-reactivity studies with related DNA processing enzymes confirmed that compound 1 possesses specific Tdp1 inhibitory activity. Deconstruction of compound 1 into discrete functional groups reveals that both components are required for inhibition of Tdp1 activity. Moreover, the synthesis of analogues of compound 1 has provided insight into the structural requirements for the inhibition of Tdp1. Surface plasmon resonance shows that compound 1 binds to Tdp1, whereas an inactive analogue fails to interact with the enzyme. Based on molecular docking and mechanistic studies, we propose that these compounds are competitive inhibitors, which mimics the oligonucleotide-peptide Tdp1 substrate. These steroid derivatives represent a novel chemotype and provide a new scaffold for developing small molecule inhibitors of Tdp1