Entropy production and time asymmetry in nonequilibrium fluctuations

The time-reversal symmetry of nonequilibrium fluctuations is experimentally investigated in two out-of-equilibrium systems namely, a Brownian particle in a trap moving at constant speed and an electric circuit with an imposed mean current. The dynamical randomness of their nonequilibrium fluctuations is characterized in terms of the standard and time-reversed entropies per unit time of dynamical systems theory. We present experimental results showing that their difference equals the thermodynamic entropy production in units of Boltzmann's constant

Doris Wishman sur les plateformes VÀD cinéphiles : une contre-histoire 2.0 du cinéma ?

Ce mémoire entend analyser et mettre en perspective la présence, début des années 2020, des films de Doris Wishman dans les catalogues des plateformes de streaming cinéphile Criterion Channel et MUBI. La réalisatrice officiait dans le genre tabou et discrédité de la sexploitation. Elle ne prétendait pas à la grille auteuriste revendiquée par les deux sites de vidéo-à-la-demande. Le phénomène à l’étude est donc celui d’un déplacement de son cinéma vers une sphère de réception nouvelle. Pour en comprendre les enjeux, je propose une double recherche-terrain. Elle consistera d’abord en l’étude de la façon dont Criterion Channel et MUBI s’approprient et valorisent ces films auprès de leurs abonnés. Elle sera ensuite discutée par la conduction d’entretiens, menés avec des professionnels du streaming et des spécialistes de Doris Wishman. Plus largement, l’analyse de phénomène cherche à comprendre comment l’expérience d’un spectateur peut différer selon le contexte de visionnement, et comment un film peut être détourné, ou non, de son intention originelle.This thesis aims to analyze and put into perspective the presence, in the early 2020s, of Doris Wishman’s films in the catalogs of cinephile video-on-demand platforms MUBI and Criterion Channel. The director was working in the taboo and discredited genre of sexploitation. She had no pretensions to the auteur-oriented positioning of the two VOD sites. The phenomenon under study is therefore a shift of her cinema towards a new sphere of reception. To understand what’s at stake, this thesis proposes a double field research. First, it will study how Criterion Channel and MUBI appropriate and promote these films among their subscribers. It will then discuss the findings through interviews with streaming professionals and Doris Wishman specialists. More broadly, this analysis seeks to understand how a viewers’s experience can differ depending on the viewing context, and how a film can be diverted from its original intention

Villejuif – Zac des Guipons (îlots A)

Le plateau de Longboyau supporte un important complexe lœssique ayant livré, entre autres, de nombreux vestiges attribuables au Paléolithique moyen. Les données anciennes se sont accumulées depuis le début du s. jusqu’aux années 1950 grâce, en particulier, aux travaux de F. Bordes. Depuis, plusieurs fouilles récentes complètent nos connaissances en prouvant la présence de niveaux d’occupation non remaniés situés à la base de la séquence des lœss récents. Cette opération s’inscrit dans le cadr..

Topological and semantic Web based method for analyzing TGF-β signaling pathways

International audienceTargeting the deleterious effects of Transforming Growth Factor TGF-β without affecting its physiological role is the common goal of therapeutic strategies aiming at curing fibrosis, the final outcome of all chronic liver disease. The pleiotropic effects of TGF-β are linked to the complex nature of its activation and signaling net- works which understanding requires modeling approaches. Our group recently developed a model of TGF-beta signal propagation based on guarded transitions (ref, Andrieux et al, 2014). In this initial work, we explored the combinatorial complexity of cell signaling, developing a discrete formalism based on guarded transitions. We imported the whole database Pathway Interaction Database into a single unified model of signal transduction. We detected 16,000 chains of reactions linking TGF-β to at least one of 159 target genes in the nucleus. The size and complexity of this model place it beyond current understanding. Its analysis requires automated tools for identifying general patterns.Currently, we focus on designing one reasoning method based on Semantic Web technologies for the analysis of signaling pathways. Our method aims at leveraging external domain knowledge represented in biomedical ontologies and linked databases to rank these candidates. We consider a signaling pathway as a set of proteins involved in the respons of a cell to an external stimulus and influencing at least one gene. The underlying reasoning methods are based on graph topological analysis, formal concepts analysis (FCA) and semantic similarity and particularity measures. First, we determine the formal concepts, maximal bi-cliques, between proteins sets and genes. Then, to determine the biological relevance of theses gene clusters, we calculate a similarity score for each cluster based on Wang semantic similarity. Using such approaches, we identify groups of genes sharing signaling networks.Cibler les effets délétères du Transforming Growth Factor, TGF-β, sans affecter son rôle physiologique est l’objectif commun des stratégies thérapeutiques visant à guérir la fibrose, la conséquence finale de toutes les maladies chroniques du foie. Les effets pléiotropiques du TGF-β sont liés à la nature complexe de son activation et du réseaux de signalisation qu’il induit, et dont la compréhension nécessite des approches de modélisation. Notre équipe a développé un modèle de la propagation du signal induit par le TGF-β base ́ sur les transitions gardées. Le développement d’un formalisme discret base ́ sur les transitions gardées permet d’étudier la complexité combinatoire de la signalisation cellulaire. Nous avons formalise ́ l’intégralité de la base de données Pathway Interaction Database en un unique modèle de la propagation du signal. Nous avons détecté 16 000 chaines de réactions reliant le TGF-β à au moins l’un des 159 gènes cibles d’intérêt Pour identifier des propriétés au sein de ces résultats il est nécessaire d’utiliser des outils automatisés.Nous développons actuellement une méthode basée sur le Web sémantique pour l’analyse des voies de signalisation. Cette méthode vise à tirer parti des connaissances de domaine externe représentées dans les ontologies biomédicales et des bases de données pour classer ces candidats. Nous considérons qu’une voie de signalisation est un ensemble des protéines impliquées dans la réaction d’une cellule à un stimulus externe et qui influence au moins un gène. Les méthodes de raisonnement sous-jacentes sont basées sur l’analyse topologique, l’analyse formelle de concepts et les mesures de similarité et de particularité sémantique. Tout d’abord, nous déterminons les concepts formels, c’est-à-dire les bi-cliques maximales, entre les ensembles de protéines et les gènes. Puis, afin de déterminer la pertinence biologique de ces groupes de gènes, nous calculons un score de similarité pour chacun des groupes, base ́ sur la mesure de Wang. La finalité est d’identifier des groupes de gènes similaires influencés par un même ensemble de voies de signalisation

Evidence for new C-terminally truncated variants of α- and β-tubulins

New C-terminally truncated α- and β-tubulin variants, both ending with an -EEEG sequence, are identified in vivo: αΔ3-tubulin, which has a specific neuronal distribution pattern (distinct from that of αΔ2-tubulin) and seems to be related to dynamic microtubules, and βΔ4-tubulin, corresponding to β2A/B-tubulin modified by truncation of four C-terminal residues, which is ubiquitously present in cells and tissues. Cellular α-tubulin can bear various carboxy-terminal sequences: full-length tubulin arising from gene neosynthesis is tyrosinated, and two truncated variants, corresponding to detyrosinated and Δ2 α‑tubulin, result from the sequential cleavage of one or two C-terminal residues, respectively. Here, by using a novel antibody named 3EG that is highly specific to the -EEEG C-terminal sequence, we demonstrate the occurrence in neuronal tissues of a new αΔ3‑tubulin variant corresponding to α1A/B‑tubulin deleted of its last three residues (EEY). αΔ3‑tubulin has a specific distribution pattern: its quantity in the brain is similar to that of αΔ2-tubulin around birth but is much lower in adult tissue. This truncated α1A/B-tubulin variant can be generated from αΔ2-tubulin by the deglutamylases CCP1, CCP4, CCP5, and CCP6 but not by CCP2 and CCP3. Moreover, using 3EG antibody, we identify a C‑terminally truncated β-tubulin form with the same -EEEG C-terminal sequence. Using mass spectrometry, we demonstrate that β2A/B-tubulin is modified by truncation of the four C-terminal residues (EDEA). We show that this newly identified βΔ4-tubulin is ubiquitously present in cells and tissues and that its level is constant throughout the cell cycle. These new C-terminally truncated α- and β-tubulin variants, both ending with -EEEG sequence, are expected to regulate microtubule physiology. Of interest, the αΔ3-tubulin seems to be related to dynamic microtubules, resembling tyrosinated-tubulin rather than the other truncated variants, and may have critical function(s) in neuronal development

Mutations in TUBG1, DYNC1H1, KIF5C and KIF2A cause malformations of cortical development and microcephaly.

International audienceThe genetic causes of malformations of cortical development (MCD) remain largely unknown. Here we report the discovery of multiple pathogenic missense mutations in TUBG1, DYNC1H1 and KIF2A, as well as a single germline mosaic mutation in KIF5C, in subjects with MCD. We found a frequent recurrence of mutations in DYNC1H1, implying that this gene is a major locus for unexplained MCD. We further show that the mutations in KIF5C, KIF2A and DYNC1H1 affect ATP hydrolysis, productive protein folding and microtubule binding, respectively. In addition, we show that suppression of mouse Tubg1 expression in vivo interferes with proper neuronal migration, whereas expression of altered γ-tubulin proteins in Saccharomyces cerevisiae disrupts normal microtubule behavior. Our data reinforce the importance of centrosomal and microtubule-related proteins in cortical development and strongly suggest that microtubule-dependent mitotic and postmitotic processes are major contributors to the pathogenesis of MCD

Leading-order determination of the gluon polarisation from semi-inclusive deep inelastic scattering data

Using a novel analysis technique, the gluon polarisation in the nucleon is re-evaluated using the longitudinal double-spin asymmetry measured in the cross section of semi-inclusive single-hadron muoproduction with photon virtuality $Q^2>1~({\rm GeV}/c)^2$. The data were obtained by the COMPASS experiment at CERN using a 160 GeV/$c$ polarised muon beam impinging on a polarised $^6$LiD target. By analysing the full range in hadron transverse momentum $p_{\rm T}$, the different $p_{\rm T}$-dependences of the underlying processes are separated using a neural-network approach. In the absence of pQCD calculations at next-to-leading order in the selected kinematic domain, the gluon polarisation $\Delta g/g$ is evaluated at leading order in pQCD at a hard scale of $\mu^2= \langle Q^2 \rangle = 3 ({\rm GeV}/c)^2$. It is determined in three intervals of the nucleon momentum fraction carried by gluons, $x_{\rm g}$, covering the range $0.04 \!<\! x_{ \rm g}\! <\! 0.28$~ and does not exhibit a significant dependence on $x_{\rm g}$. The average over the three intervals, $\langle \Delta g/g \rangle = 0.113 \pm 0.038_{\rm (stat.)}\pm 0.036_{\rm (syst.)}$ at $\langle x_{\rm g} \rangle \approx 0.10$, suggests that the gluon polarisation is positive in the measured $x_{\rm g}$ range.Comment: 14 pages, 6 figure

Jet energy measurement with the ATLAS detector in proton-proton collisions at root s=7 TeV

The jet energy scale and its systematic uncertainty are determined for jets measured with the ATLAS detector at the LHC in proton-proton collision data at a centre-of-mass energy of √s = 7TeV corresponding to an integrated luminosity of 38 pb-1. Jets are reconstructed with the anti-kt algorithm with distance parameters R=0. 4 or R=0. 6. Jet energy and angle corrections are determined from Monte Carlo simulations to calibrate jets with transverse momenta pT≥20 GeV and pseudorapidities {pipe}η{pipe}<4. 5. The jet energy systematic uncertainty is estimated using the single isolated hadron response measured in situ and in test-beams, exploiting the transverse momentum balance between central and forward jets in events with dijet topologies and studying systematic variations in Monte Carlo simulations. The jet energy uncertainty is less than 2. 5 % in the central calorimeter region ({pipe}η{pipe}<0. 8) for jets with 60≤pT<800 GeV, and is maximally 14 % for pT<30 GeV in the most forward region 3. 2≤{pipe}η{pipe}<4. 5. The jet energy is validated for jet transverse momenta up to 1 TeV to the level of a few percent using several in situ techniques by comparing a well-known reference such as the recoiling photon pT, the sum of the transverse momenta of tracks associated to the jet, or a system of low-pT jets recoiling against a high-pT jet. More sophisticated jet calibration schemes are presented based on calorimeter cell energy density weighting or hadronic properties of jets, aiming for an improved jet energy resolution and a reduced flavour dependence of the jet response. The systematic uncertainty of the jet energy determined from a combination of in situ techniques is consistent with the one derived from single hadron response measurements over a wide kinematic range. The nominal corrections and uncertainties are derived for isolated jets in an inclusive sample of high-pT jets. Special cases such as event topologies with close-by jets, or selections of samples with an enhanced content of jets originating from light quarks, heavy quarks or gluons are also discussed and the corresponding uncertainties are determined. © 2013 CERN for the benefit of the ATLAS collaboration

Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

The inclusive and dijet production cross-sections have been measured for jets containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV, using the ATLAS detector at the LHC. The measurements use data corresponding to an integrated luminosity of 34 pb^-1. The b-jets are identified using either a lifetime-based method, where secondary decay vertices of b-hadrons in jets are reconstructed using information from the tracking detectors, or a muon-based method where the presence of a muon is used to identify semileptonic decays of b-hadrons inside jets. The inclusive b-jet cross-section is measured as a function of transverse momentum in the range 20 < pT < 400 GeV and rapidity in the range |y| < 2.1. The bbbar-dijet cross-section is measured as a function of the dijet invariant mass in the range 110 < m_jj < 760 GeV, the azimuthal angle difference between the two jets and the angular variable chi in two dijet mass regions. The results are compared with next-to-leading-order QCD predictions. Good agreement is observed between the measured cross-sections and the predictions obtained using POWHEG + Pythia. MC@NLO + Herwig shows good agreement with the measured bbbar-dijet cross-section. However, it does not reproduce the measured inclusive cross-section well, particularly for central b-jets with large transverse momenta.Comment: 10 pages plus author list (21 pages total), 8 figures, 1 table, final version published in European Physical Journal

Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC

The uncertainty on the calorimeter energy response to jets of particles is derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the calorimeter response to single isolated charged hadrons is measured and compared to the Monte Carlo simulation using proton-proton collisions at centre-of-mass energies of sqrt(s) = 900 GeV and 7 TeV collected during 2009 and 2010. Then, using the decay of K_s and Lambda particles, the calorimeter response to specific types of particles (positively and negatively charged pions, protons, and anti-protons) is measured and compared to the Monte Carlo predictions. Finally, the jet energy scale uncertainty is determined by propagating the response uncertainty for single charged and neutral particles to jets. The response uncertainty is 2-5% for central isolated hadrons and 1-3% for the final calorimeter jet energy scale.Comment: 24 pages plus author list (36 pages total), 23 figures, 1 table, submitted to European Physical Journal