17 research outputs found
Mitochondrial physiology
As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery
Mitochondrial physiology
As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery
InterféromÚtre à conversion de fréquences ALOHA en bande L : Tests en laboratoire et intégration au réseau de télescopes CHARA
The use of telescope arrays in astronomy allows to observe stellar objects with a high angular resolution. For the imaging of cold objects, the thermal infrared spectral bands are particularly interesting for astronomers. However, at these wavelengths, the instrumentâs optical elements emit their own thermal radiation and it becomes necessary to set up complex and expensive cryogenic systems, as well as adequate infrastructures, which are often difficult to implement because of their large dimensions. The approach proposed by our team at the XLIM laboratory in Limoges combines non-linear and guided optics for high-resolution astronomy. The ALOHA (Astronomical Light Optical Hybrid Analysis) project consists in implementing a frequency conversion fibre link interferometer in the thermal infrared domain. This thesis is based on a set of previous studies and presents the laboratory development and integration at CHARA (Center for High Angular Resolution Astronomy, USA CA) of the ALOHA project interferometer at 3,5 ÎŒm (L-band), in collaboration with Georgia State University. Original fibre length control systems, necessary for long-distance fibre interferometry, were developed and characterised by our team before being integrated in situ. The acquisition of interference fringes on the sky, without frequency conversion, has been successfully achieved. A significant improvement in fringe contrast and signal-to-noise ratio is demonstrated experimentally with the activation of the servocontrol systems. Mechanical and thermal stability tests were then carried out during the integration of the conversion modules into two CHARA telescopes, in anticipation of future 3,5 ÎŒm frequency conversion tests and interference fringes on the sky.En astronomie, lâutilisation de rĂ©seaux de tĂ©lescopes permet dâobserver des objets stellaires avec une haute rĂ©solution angulaire. Pour les astronomes, les domaines de lâinfrarouge thermique sont particuliĂšrement intĂ©ressants pour lâobservation dâobjets froids. Cependant, les Ă©lĂ©ments optiques des instruments Ă ces longueurs dâondes ont leurs propres rayonnements thermiques et il devient alors nĂ©cessaire de mettre en place des systĂšmes cryogĂ©niques complexes et coĂ»teux, ainsi que des infrastructures adĂ©quates, souvent difficiles Ă mettre en Ćuvre de par leurs grandes dimensions. Lâapproche proposĂ©e par notre Ă©quipe au laboratoire XLIM Ă Limoges consiste Ă associer lâoptique non linĂ©aire et lâoptique guidĂ©e pour lâastronomie haute rĂ©solution. Le projet ALOHA (Astronomical Light Optical Hybrid Analysis) consiste Ă mettre en Ćuvre un interfĂ©romĂštre Ă liaisons fibrĂ©es Ă conversion de frĂ©quences dans lâinfrarouge thermique. Cette thĂšse sâappuie sur un ensemble dâĂ©tudes antĂ©rieures et prĂ©sente le dĂ©veloppement en laboratoire, puis lâintĂ©gration Ă CHARA (Center for High Angular Resolution Astronomy, USA CA) de lâinterfĂ©romĂštre du projet ALOHA Ă 3,5 ÎŒm (en bande L), en collaboration avec la Georgia State University. Des dispositifs originaux dâasservissement des longueurs des fibres, nĂ©cessaires en interfĂ©romĂ©trie fibrĂ©e longue distance, ont Ă©tĂ© dĂ©veloppĂ©s et caractĂ©risĂ©s par notre Ă©quipe avant dâĂȘtre intĂ©grĂ©s in situ. Lâacquisition de franges dâinterfĂ©rence sur le ciel, sans conversion de frĂ©quences, a Ă©tĂ© rĂ©alisĂ©e avec succĂšs. Une amĂ©lioration significative du contraste des franges et du rapport signal Ă bruit est dĂ©montrĂ©e expĂ©rimentalement avec lâactivation des systĂšmes dâasservissement. Des tests de stabilitĂ© mĂ©canique et thermique ont ensuite Ă©tĂ© rĂ©alisĂ©s lors de lâintĂ©gration des modules de conversion dans deux tĂ©lescopes de CHARA, en prĂ©vision des futurs tests de conversion de frĂ©quences et lâobtention de franges dâinterfĂ©rence sur le ciel Ă 3,5 ÎŒm du projet ALOHA
InterféromÚtre à conversion de fréquences ALOHA en bande L : Tests en laboratoire et intégration au réseau de télescopes CHARA
The use of telescope arrays in astronomy allows to observe stellar objects with a high angular resolution. For the imaging of cold objects, the thermal infrared spectral bands are particularly interesting for astronomers. However, at these wavelengths, the instrumentâs optical elements emit their own thermal radiation and it becomes necessary to set up complex and expensive cryogenic systems, as well as adequate infrastructures, which are often difficult to implement because of their large dimensions. The approach proposed by our team at the XLIM laboratory in Limoges combines non-linear and guided optics for high-resolution astronomy. The ALOHA (Astronomical Light Optical Hybrid Analysis) project consists in implementing a frequency conversion fibre link interferometer in the thermal infrared domain. This thesis is based on a set of previous studies and presents the laboratory development and integration at CHARA (Center for High Angular Resolution Astronomy, USA CA) of the ALOHA project interferometer at 3,5 ÎŒm (L-band), in collaboration with Georgia State University. Original fibre length control systems, necessary for long-distance fibre interferometry, were developed and characterised by our team before being integrated in situ. The acquisition of interference fringes on the sky, without frequency conversion, has been successfully achieved. A significant improvement in fringe contrast and signal-to-noise ratio is demonstrated experimentally with the activation of the servocontrol systems. Mechanical and thermal stability tests were then carried out during the integration of the conversion modules into two CHARA telescopes, in anticipation of future 3,5 ÎŒm frequency conversion tests and interference fringes on the sky.En astronomie, lâutilisation de rĂ©seaux de tĂ©lescopes permet dâobserver des objets stellaires avec une haute rĂ©solution angulaire. Pour les astronomes, les domaines de lâinfrarouge thermique sont particuliĂšrement intĂ©ressants pour lâobservation dâobjets froids. Cependant, les Ă©lĂ©ments optiques des instruments Ă ces longueurs dâondes ont leurs propres rayonnements thermiques et il devient alors nĂ©cessaire de mettre en place des systĂšmes cryogĂ©niques complexes et coĂ»teux, ainsi que des infrastructures adĂ©quates, souvent difficiles Ă mettre en Ćuvre de par leurs grandes dimensions. Lâapproche proposĂ©e par notre Ă©quipe au laboratoire XLIM Ă Limoges consiste Ă associer lâoptique non linĂ©aire et lâoptique guidĂ©e pour lâastronomie haute rĂ©solution. Le projet ALOHA (Astronomical Light Optical Hybrid Analysis) consiste Ă mettre en Ćuvre un interfĂ©romĂštre Ă liaisons fibrĂ©es Ă conversion de frĂ©quences dans lâinfrarouge thermique. Cette thĂšse sâappuie sur un ensemble dâĂ©tudes antĂ©rieures et prĂ©sente le dĂ©veloppement en laboratoire, puis lâintĂ©gration Ă CHARA (Center for High Angular Resolution Astronomy, USA CA) de lâinterfĂ©romĂštre du projet ALOHA Ă 3,5 ÎŒm (en bande L), en collaboration avec la Georgia State University. Des dispositifs originaux dâasservissement des longueurs des fibres, nĂ©cessaires en interfĂ©romĂ©trie fibrĂ©e longue distance, ont Ă©tĂ© dĂ©veloppĂ©s et caractĂ©risĂ©s par notre Ă©quipe avant dâĂȘtre intĂ©grĂ©s in situ. Lâacquisition de franges dâinterfĂ©rence sur le ciel, sans conversion de frĂ©quences, a Ă©tĂ© rĂ©alisĂ©e avec succĂšs. Une amĂ©lioration significative du contraste des franges et du rapport signal Ă bruit est dĂ©montrĂ©e expĂ©rimentalement avec lâactivation des systĂšmes dâasservissement. Des tests de stabilitĂ© mĂ©canique et thermique ont ensuite Ă©tĂ© rĂ©alisĂ©s lors de lâintĂ©gration des modules de conversion dans deux tĂ©lescopes de CHARA, en prĂ©vision des futurs tests de conversion de frĂ©quences et lâobtention de franges dâinterfĂ©rence sur le ciel Ă 3,5 ÎŒm du projet ALOHA
L-Band ALOHA frequency conversion interferometer : Laboratory tests and integration at the CHARA array
En astronomie, lâutilisation de rĂ©seaux de tĂ©lescopes permet dâobserver des objets stellaires avec une haute rĂ©solution angulaire. Pour les astronomes, les domaines de lâinfrarouge thermique sont particuliĂšrement intĂ©ressants pour lâobservation dâobjets froids. Cependant, les Ă©lĂ©ments optiques des instruments Ă ces longueurs dâondes ont leurs propres rayonnements thermiques et il devient alors nĂ©cessaire de mettre en place des systĂšmes cryogĂ©niques complexes et coĂ»teux, ainsi que des infrastructures adĂ©quates, souvent difficiles Ă mettre en Ćuvre de par leurs grandes dimensions. Lâapproche proposĂ©e par notre Ă©quipe au laboratoire XLIM Ă Limoges consiste Ă associer lâoptique non linĂ©aire et lâoptique guidĂ©e pour lâastronomie haute rĂ©solution. Le projet ALOHA (Astronomical Light Optical Hybrid Analysis) consiste Ă mettre en Ćuvre un interfĂ©romĂštre Ă liaisons fibrĂ©es Ă conversion de frĂ©quences dans lâinfrarouge thermique. Cette thĂšse sâappuie sur un ensemble dâĂ©tudes antĂ©rieures et prĂ©sente le dĂ©veloppement en laboratoire, puis lâintĂ©gration Ă CHARA (Center for High Angular Resolution Astronomy, USA CA) de lâinterfĂ©romĂštre du projet ALOHA Ă 3,5 ÎŒm (en bande L), en collaboration avec la Georgia State University. Des dispositifs originaux dâasservissement des longueurs des fibres, nĂ©cessaires en interfĂ©romĂ©trie fibrĂ©e longue distance, ont Ă©tĂ© dĂ©veloppĂ©s et caractĂ©risĂ©s par notre Ă©quipe avant dâĂȘtre intĂ©grĂ©s in situ. Lâacquisition de franges dâinterfĂ©rence sur le ciel, sans conversion de frĂ©quences, a Ă©tĂ© rĂ©alisĂ©e avec succĂšs. Une amĂ©lioration significative du contraste des franges et du rapport signal Ă bruit est dĂ©montrĂ©e expĂ©rimentalement avec lâactivation des systĂšmes dâasservissement. Des tests de stabilitĂ© mĂ©canique et thermique ont ensuite Ă©tĂ© rĂ©alisĂ©s lors de lâintĂ©gration des modules de conversion dans deux tĂ©lescopes de CHARA, en prĂ©vision des futurs tests de conversion de frĂ©quences et lâobtention de franges dâinterfĂ©rence sur le ciel Ă 3,5 ÎŒm du projet ALOHA.The use of telescope arrays in astronomy allows to observe stellar objects with a high angular resolution. For the imaging of cold objects, the thermal infrared spectral bands are particularly interesting for astronomers. However, at these wavelengths, the instrumentâs optical elements emit their own thermal radiation and it becomes necessary to set up complex and expensive cryogenic systems, as well as adequate infrastructures, which are often difficult to implement because of their large dimensions. The approach proposed by our team at the XLIM laboratory in Limoges combines non-linear and guided optics for high-resolution astronomy. The ALOHA (Astronomical Light Optical Hybrid Analysis) project consists in implementing a frequency conversion fibre link interferometer in the thermal infrared domain. This thesis is based on a set of previous studies and presents the laboratory development and integration at CHARA (Center for High Angular Resolution Astronomy, USA CA) of the ALOHA project interferometer at 3,5 ÎŒm (L-band), in collaboration with Georgia State University. Original fibre length control systems, necessary for long-distance fibre interferometry, were developed and characterised by our team before being integrated in situ. The acquisition of interference fringes on the sky, without frequency conversion, has been successfully achieved. A significant improvement in fringe contrast and signal-to-noise ratio is demonstrated experimentally with the activation of the servocontrol systems. Mechanical and thermal stability tests were then carried out during the integration of the conversion modules into two CHARA telescopes, in anticipation of future 3,5 ÎŒm frequency conversion tests and interference fringes on the sky
: Danse et astronomie
Compte-rendu de collaboration Art-ScienceEn rĂ©sidence Ă l'Observatoire de Lille en 2018, Julie Magri invite Ă dĂ©couvrir sa recherche chorĂ©graphique. Danseuse de flamenco, elle rĂ©interprĂšte lâordre du chaos Ă partir des Ă©tudes et modĂ©lisations du nuage de Oort dĂ©veloppĂ©es par le laboratoire. ChaoOmĂšte est un court-mĂ©trage de 10 minutes suivi dâun spectacle de danse dâenviron 45 minutes
The Bobath concept â a model to illustrate clinical practice: responding to comments on Michielsen et al.
Influence of the input-stage architecture on the in-laboratory test of a mid-infrared interferometer: application to the ALOHA up-conversion interferometer in the L band
International audienceIn the framework of the Astronomical Light Optical Hybrid Analysis (ALOHA) laboratory mid-infrared (MIR) up-conversion fibred interferometer in the L band, we report on the influence of the input-stage architecture. Using an amplitude division set-up in the visible or near-infrared is a straightforward choice in most cases. In the MIR context, the results are slightly different and we show that a wavefront division set-up is needed. These in-laboratory principle experiments allow us to measure a reliable 88âperâcent instrumental contrast with high flux and to obtain fringes from faint sources at 3.5â ÎŒm with a spectral bandwith of 37ânm converted to 817ânm. An equivalent limiting L-band magnitude around 3.9, equivalent to 3.0âfWânm -1, could be demonstrated on 1âm class telescopes. This opens the possibility of planning future on-sky tests at the Center for High Angular Resolution Astronomy (CHARA) array and of predicting the performance attained