Cheminements et ouvertures sur des espaces intimes : regards sur le théâtre de Thomas Kilroy

L’oeuvre de Thomas Kilroy est incontournable pour quiconque s’intéresse au théâtre irlandais contemporain. Par l’entremise de son oeuvre, cet auteur cherche à remettre en question les certitudes communautaires : l’homosexualité, la religion, les visions claniques mortifères sont des leitmotivs qui traversent ses pièces. Son association avec la compagnie théâtrale « Field Day » — reconnue pour ses prises de position politiques —, est également étudiée, et ce, pour souligner l’importance de sa contribution au théâtre irlandais en tant qu’artiste et en tant qu’animateur.Thomas Kilroy's work is considered seminal in the field of contemporary Irish drama. Through his work, Kilroy challenges communal certainties: homosexuality, religion, deadly clannish beliefs are leitmotifs that mark his oeuvre. His association with Field Day Theatre Company—known for its political activism—, is also studied in order to highlight his contribution to Irish theatre both as an artist and as a facilitator

Light-matter interaction with atomic ensembles

Tesi en modalitat de cotutela: Universitat Politècnica de Catalunya i Université Paris VII-Denis Diderot(English) The study of quantum light-matter interaction with atomic ensembles is an active research area. This kind of system allows fundamental studies on measurement in the context of continuous variables, in collective entanglement and in quantum simulations. This field of research is also interesting in the context of quantum metrology, quantum networking and quantum computation. In this thesis two complementary aspects of light matter interaction with atomic ensembles have been studied with trapped ions and cold neutral atoms. The trapped ion experiment is intended to evaluate the possibility to use large ion clouds for realizing a quantum memory with long coherence times. Whereas the cold atom experiment focused on the use of quantum non demolition measurements to evaluate non- Gaussian states. This experiment is similar to quantum networking experiment currently planned. Laser cooled trapped ions can reach a crystalline phase due to the strong Coulomb repulsion between ions. In this phase the relative positions between the ions is xed avoiding collisions and the ions to explore magnetic eld inhomogeneities which can be a source of coherence loss. At low ion number, long coherence times have been demonstrated. With large ion numbers, the trapping mechanism can induce heating of the ion cloud thus making more di cult to obtain the crystallized regime. During this thesis, large Coulomb crystals containing more than 1x10 6 ions have been obtained and signature of electromagnetically induced transparency in such system have been obtained. This study also revealed limitations of this kind of systems which have to be further studied to allow strong light matter interaction probability with cold large ion ensembles in a regime allowing for long coherence times. Neutral atoms systems allow strong light matter coupling probabilities but usually reduced coherence times. Quantum memories, entanglement between atoms and light, high precision magnetometry have been demonstrated with neutral atomic vapors. The system used during this thesis is designed to allow strong light matter coupling probability with detuned polarized light pulses, allowing to precisely measure the spin state of the atomic system without destruction and low noise. The measurement noise of the system is lower than the atomic noise opening the way for collective entanglement (via measurement induced spin squeezing) and ultra sensitive magnetic eld measurements. This system is closely related with systems designed for quantum networking and quantum memories. Non Gaussian atomic states are a resource for quantum computation and quantum communication, in the context of atomic physics experiments, their detection can be di cult. The work presented in this thesis focuses on the detection of non Gaussian states in atomic ensembles using cumulants, and in particular their noise properties.(Español) El estudio de la interacción luz materia con conjuntos atómicos es un área de investigación activa. Este tipo de sistema permite fundamental estudios sobre la medición en el contexto de las variables continuas, en entrelazamiento colectiva y en las simulaciones cuánticas. Este campo de la investigación también es interesante en el contexto de la metrología cuántica, comunicación cuántica y la computación cuántica. En esta tesis dos aspectos complementarios de la interacción luz materia con conjuntos atómicos han sido estudiados con iones atrapados y átomos neutros fríos. El experimento de iones atrapados pretende evaluar la posibilidad de utilizar grandes nubes de iones para la realización de una memoria cuántica con largo tiempo de coherencia. En vez de que el experimento de átomos fríos se centró en el uso de medidas de no demolición cuántica para evaluar estados no gaussianos. Este experimento es parecido a los experimentos de comunicación cuántica que se desarrollan actualmente. Los iones atrapados enfriados por láser pueden llegar a una fase cristalina debido a la fuerte repulsión de Coulomb entre los iones. En esta fase, las relativas posiciones entre los iones se fijan de manera a evitar las colisiones y los iones que exploran inhomogeneidades del campo magnético que puede ser una fuente de pérdida de coherencia. Con bajo número de iones, largos tiempos de coherencia han sido demostrados. Con iones numerosos, el mecanismo de captura puede inducir un calentamiento de la nube de iones, haciendo así más difícil de obtener el régimen cristalizado. Durante esta tesis, los cristales de Coulomb grandes que contiene más de 1 x 10 6 iones se han obtenidos y la prueba de la transparencia inducida electromagnéticamente en tal sistema ha sido obtenida. Este estudio también reveló las limitaciones de este tipo de sistemas que tienen que ser estudiado más a fondo para obtenir una fuerte probabilidad de interacción con conjuntos de iones fríos en un régimen permitiendo largos tiempos de coherencia. Los sistemas de átomos neutros permiten fuertes probabilidades de acoplamiento luz materia, pero generalmente reduce los tiempos de coherencia. Memorias cuánticas, el entrelazamiento entre átomos y la luz, magnetometría de alta precisión han sido demostrados en experimentos relaciondaos con vapores atómicos neutros. El sistema utilizado en esta tesis se ha diseñado para permitir que la probabilidad de acoplamiento luz materia sea importante, con pulsos de luz polarizada, lo que permite medir con precisión el estado de espín del sistema atómico sin destrucción y con bajo ruido. La medición del ruido del sistema es más baja que el ruido atómico, lo que podría inducir el entrelazamiento colectivo de los espines atómicos (a través del squeezing de espines inducido por la medición) y mediciones de campo magnético ultra sensibles. Este sistema está estrechamente relacionado con sistemas diseñados para la creación de comunicación cuántica y memorias cuánticas. Los estados atómicos no gaussianos constituyen un recurso para la computación cuántica y la comunicación cuántica, en el contexto de los experimentos de física atómica, su detección puede ser difícil. El trabajo presentado en esta tesis se centra en la detección de los estados no gaussianos en conjuntos atómicos utilizando cumulants, y en particular el ruido relacionado con la medición de los cumulants.Postprint (published version

Stride-to-stride variability while backward counting among healthy young adults

BACKGROUND: Little information exists about the involvement of attention in the control of gait rhythmicity. Variability of both stride time and stride length is closely related to the control of the rhythmic stepping mechanism. We sought 1) to determine whether backward counting while walking could provoke significant gait changes in mean values and coefficients of variation of stride velocity, stride time and stride length among healthy young adults; and 2) to establish whether change in stride-to-stride variability could be related to dual-task related stride velocity change, attention, or both. METHODS: Mean values and coefficients of variation of stride velocity, stride time and stride length were recorded using the Physilog(®)-system, at a self-selected walking speed in 49 healthy young adults (mean age 24.1 ± 2.8 years, women 49%) while walking alone and walking with simultaneous backward counting. Performance on backward counting was evaluated by recording the number of figures counted while sitting alone and while walking. RESULTS: Compared with walking alone, a significant dual-task-related decrease was found for the mean values of stride velocity (p < 0.001), along with a small but significant increase for the mean values and coefficients of variation of stride time (p < 0.001 and p = 0.015, respectively). Stride length parameters did not change significantly between both walking conditions. Dual-task-related increase of coefficient of variation of stride time was explained by changing stride velocity and variability between subjects but not by backward counting. The number of figures counted while walking decreased significantly compared to backward counting alone. Further, the dual-task related decrease of the number of enumerated figures was significantly higher than the dual-task related decrease of stride velocity (p = 0.013). CONCLUSION: The observed performance-changes in gait and backward counting while dual tasking confirm that certain aspects of walking are attention-demanding in young adults. In the tested group of 49 young volunteers, dual tasking caused a small decrease in stride velocity and a slight increase in the stride-to-stride variability of stride time, while stride velocity variability was not affected by the attention-demanding task. The increase in stride time variability was apparently the result of a change in gait speed, but not a result of dual tasking. This suggests that young adults require minimal attention for the control of the rhythmic stepping mechanism while walking

Artificial Intelligence with Light Supervision: Application to Neuroimaging

Recent developments in artificial intelligence research have resulted in tremendous success in computer vision, natural language processing and medical imaging tasks, often reaching human or superhuman performance. In this thesis, I further developed artificial intelligence methods based on convolutional neural networks with a special focus on the automated analysis of brain magnetic resonance imaging scans (MRI). I showed that efficient artificial intelligence systems can be created using only minimal supervision, by reducing the quantity and quality of annotations used for training. I applied those methods to the automated assessment of the burden of enlarged perivascular spaces, brain structural changes that may be related to dementia, stroke, mult

Motivations des bénévoles : une revue de la littérature.

Après avoir montré l’importance des bénévoles comme ressource des associations, cette communication pose la question de la nature et de l’intensité de leurs motivations. Une revue des travaux de recherche est alors proposée, pour aboutir à une typologie basée sur la nature des hypothèses et sur la méthodologie utilisée. Pour finir, nous montrons que des travaux en Sciences de Gestion pourraient certainement enrichir le débat sur cette question de recherche.Motivations, bénévoles, modèles économiques, modèles sociologiques, psychologie sociale

Point-diffraction interferometry for wavefront sensing in adaptive optics

The work presented in this thesis aims at the development and validation of a wavefront sensor concept for adaptive optics (AO) called the pupil-modulated Point-Diffraction Interferometer (m-PDI). The m-PDI belongs to a broader family of wavefront sensors called Point-Diffraction Interferometers (PDIs), which make use of a small pinhole to filter a portion of the incoming light, hence generating a reference beam. This allows them to perform wavefront sensing on temporally incoherent light, such as natural guide stars in the context of astronomical AO. Due to their high sensitivity, PDIs are being developed to address several difficult problems in AO, namely measuring quasi-static aberrations to a high degree of accuracy, the cophasing of segmented apertures, and reaching a high correction regime known as extreme AO. But despite their advantages, they remain limited by their narrow chromatic range, around ∆λ = 2% relative to central bandwidth, and short dynamic range, generally of ±π/2. The purpose of developing the m-PDI is to explore whether this new concept has any ad- vantages regarding these limitations. Indeed, we find that the m-PDI has a maximum chromatic bandwidth of 66% relative to the central wavelength and a dynamic range at least 4 times larger than that of other PDIs. Although the m-PDI concept had been proposed previously, it had not been explored to the extent reached in this manuscript. This thesis presents an initial investigation into the m-PDI, beginning with the development of the theory. Here the theoretical framework is laid out to explain how interference fringes are modulated by the wavefront, how to then demodulate the propa- gating electric field’s phase and then finally how to measure the signal-to-noise ratio (SNR). After building analytical and numerical models, a prototype is designed, built and characterised using CHOUGH, a high-order AO testbed in the lab. This incarnation of the m-PDI is called the Calibration & Alignment Wavefront Sensor (CAWS). The characterisation of the CAWS shows two things. The first one is that the CAWS’ response is approximately flat across its spatial frequency domain. The second one is that its dynamic range decreases at higher frequencies, suggesting that it depends, amongst other things, on the wavefront’s slope. In order to prove that m-PDIs can be used for AO, a control loop is closed using the CAWS and CHOUGH’s deformable mirror, with both monochromatic and broadband light. The results show that the final Strehl ratio increases from 0.2 to 0.66, at a wavelength of 633 nm. The difference in residual aberrations seen separately by the imaging camera and by the CAWS is about 20 nm RMS. This is explained by non-common path aberrations and low order aberrations which are invisible to the CAWS. Finally, the instrument was tested on the CANARY AO bench at the William Herschel Telescope. The CAWS was successful at characterising the quasi- static aberrations of the system and at demodulating the phase of wavefronts produced with the deformable mirror. When demodulating on-sky residual aberrations at the back of CANARY’s single-conjugate AO loop, the SNR remained too low for effective wavefront demodulation, only sporadically in- creasing above 1. These results are not discouraging as the CAWS was only a first prototype and CANARY is not a high-order system, reaching a Strehl ratio of around 0.5% at 675 nm. The lessons and improvements for future de- signs are to increase the diameter of the instrument’s pinhole by at least twice, and deliver it a higher Strehl ratio by moving towards longer wavelengths and employing a higher order AO system

Renégocier l'intraduisible: perspectives pour un humanisme transculturel

International audienc

Un exemple de stratégie de renforcement de moyennes entreprises : l'échange relationnel comme moyen de gérer la dépendance économique vis-à-vis des clients.

Parmi les options stratégiques des moyennes entreprises (ME), les stratégies de renforcement visant à gérer la dépendance économique vis-à-vis des clients, peuvent s'avérer un facteur de vulnérabilité (Saporta, 1989). La mise en place d'un échange relationnel entre la ME et ses clients relève selon nous, de ce type de stratégie. Après avoir défini l'échange relationnel, cet article présente les résultats d'une étude empirique portant sur les relations de trente ME françaises avec leur plus gros client, appartenant à trois secteurs industriels. Il y apparaît qu'une facette de l'échange relationnel, à savoir le souhait d'établir une relation à long terme, permet aux ME de rendre, à leur tour, leur plus gros client déopendant d'elles-mêmes. En instaurant une dépendance mutuelle, l'échange relationnel rend ainsi caduc le lien entre dépendance économique et vulnérabilité de la ME.dépendance économique, échange relationnel, stratégie