Advances in Precision Calculations of Higgs Boson and Single Top Quark Production at the Large Hadron Collider

Since the discovery of the Higgs boson in 2012, particle physics has entered an era of precision. With the upcoming increase in luminosity of the Large Hadron Collider (LHC), we will gain access to deep and detailed insights into the behaviour of fundamental particles. On the theoretical side, the description of partonic cross sections with next-to-next-to-leading order (NNLO) accuracy in Quantum Chromodynamics (QCD) is becoming a standard. Despite the astonishing agreement between the experiments and theoretical predictions, it is clear that the Standard Model (SM) of particle physics is incomplete. One way to search for New Physics is to push the accuracy of the theoretical predictions and experimental measurements further. In this thesis, we study three problems related to precision description of Higgs boson and top quark production at the LHC. In the first part, we investigate the interference contribution between two Higgs production mechanisms in the pp → H + jetc process. This process can be used to study the Yukawa coupling of the charm quark. The interference studied in this thesis requires a helicity flip on the charm-quark line, forcing us to treat the charm quarks as massive. This requirement leads to unconventional QCD phenomena, such as the importance of soft quarks and unusual collinear factorisation. In the second part, we calculate the so-called non-factorisable corrections to t-channel single top production. These corrections arise from the crosstalk between the two fermion lines present in this process. Until now, the non-factorisable contributions to single top production have been neglected because they do not appear at next-to-leading order (NLO) and they are colour-suppressed compared to the factorisable ones. However, recent studies indicate that the factorisable corrections are relatively small at NNLO and that the non-factorisable ones can be dynamically enhanced. We compute the non-factorisable corrections and discuss their numerical impact on t-channel single top production at the LHC and the Future Circular Collider (FCC). In the third part, we consider the same type of corrections to Higgs production in weak boson fusion (WBF). Contrary to the case of t-channel single top production, an exact computation of these corrections is currently impossible. We construct an expansion of the double-virtual contribution around the forward limit of the tagging jets. It turns out that the expression of the double-virtual contribution at the next-to-leading order in the eikonal approximation can be expressed in a quite compact form

KECAKAPAN MANAJERIAL DAN KEPEMILIKAN MANAJERIAL TERHADAP KUALITAS LABA YANG DIMODERASI OLEH KEAHLIAN KEUANGAN KOMITE AUDIT DAN GENDER

Tujuan penelitian ini untuk menguji pengaruh kecakapan manajerial dan kepemilikan manajerial terhadap kualitas laba yang dimoderasi oleh keahlian keuangan komite audit dan keragaman. Teknik pengambilan sampel menggunakan purposive sampling perbankan konvensional periode 2014-2018. Pendekatan yang digunakan adalah regresi data panel. Hasil penelitian menunjukkan bahwa kecakapan manajerial berpengaruh negatif dan signifikan terhadap kualitas laba, kepemilikan manajerial berpengaruh positif terhadap kualitas laba, keahlian keuangan komite audit memoderasi secara posiif pengaruh kecakapan manajerial terhadap kualitas laba manajerial terhadap kualitas laba; gender memoderasi secara positif pengaruh kecakapan manajerial terhadap kualitas laba; dan gender tidak memoderasi pengaruh kepemilikan manajerial terhadap kualitas laba

Suse, terres cuites islamiques. Paris et Gand, Snoeck/Musée du Louvre, 2005, 262 p., ill.

Aboutissement du travail de récolement et d’étude mené par G. Joel, ce catalogue rassemble le matériel en céramique non glaçurée, issu des niveaux islamiques des fouilles de Suse et conservé au département des Arts de l’Islam du musée du Louvre. Une introduction par S. Makariou retrace l’histoire des fouilles françaises à Suse, l’arrivée des pièces au Louvre et présente les caractéristiques et l’intérêt de cette collection. Le corpus de 337 pièces est réparti par typologie : cruches, pichets,..

Adaptabilité fonctionnelle des actes moteurs : coordinations propriospinales et ajustements des réseaux locomoteurs centraux par le traitement des infromations sensorielles

Se nourrir, se reproduire, fuir un danger, explorer son environnement, sont autant de comportements qui nécessitent le déplacement de l'animal. Ainsi, la locomotion apparaît comme un système moteur crucial et vital à la survie d'une espèce et requiert la production de mouvements hautement adaptés afin de satisfaire la réalisation de tous ces comportements. Toute atteinte de la fonction locomotrice entraînera donc une perturbation multisystémique plus ou moins prononcée. Afin de comprendre pourquoi et comment un organe ne fonctionne plus, il est nécessaire au préalable de connaître son fonctionnement dans les conditions normales. Au cours de mon travail doctoral, j'ai donc développé chez le rat nouveau-né un modèle expérimental de moelle épinière isolée in vitro qui, compte tenu de son accessibilité directe, nous permet d'étudier de façon précise les mécanismes intimes du fonctionnement du système nerveux par une approche combinée électrophysiologique, pharmacologique et lésionnelle. Dans le cadre des études sur la neurobiologie des réseaux, ma problématique de recherche a été plus particulièrement focalisée sur les mécanismes cellulaires et synaptiques impliqués dans les coordinations motrices produites par différents générateurs de rythmes locomoteurs. Au final et de façon plutôt inattendue, les coordinations locomotrices nécessiteraient en particulier un flux d'informations dans le sens caudo-rostral entre les différents réseaux neuronaux spinaux.To eat, reproduce, to explore the environment and escape from danger are all behaviors that require displacement of the organism. The locomotor act is therefore critical to animal survival, necessitating the production of highly adaptive movements to satisfy these other behavioral demands. As a consequence, any locomotor deficit can have a major impact at the multiple systems level. However in order to understand the dysfunction of any biological system, it is first necessary to understand its operation under normal conditions. For my doctoral study, therefore, I used the isolated spinal cord of the neonatal rat as an in vitro experimental model, which by virtue of its direct accessibility allows investigation of the mechanistic basis of nervous system function through the combination of electrophysiological, pharmacological and lesional approaches. In the context of exploring the neurobiology of neuronal networks, my thesis research focused on the cellular and synaptic mechanisms that are implicated in the functional coordination between the spatially separate rhythm-generating circuitry responsible for quadrupedal locomotion. An unexpected finding is that locomotor coordination is particularly dependent upon a caudo-rostral flow of propriospinal information between the different spinal networks

Eagle’s Nest. Ismaili Castles in Iran and Syria. London, I.B. Tauris Publishers en association avec The Institute of Islamili Studies, 2005, 321 p., 40 ill. coul.

L’ouvrage se décompose en deux parties. La première constitue une introduction historique où l’A. retrace les débuts de la communauté ismalienne nizarite et sa montée en puissance jusqu’à la défaite face aux Mongols en 1256, en s’appuyant principalement sur les publications récentes de Farhad Daftary. Contre la vision fantasmée occidentale des fameux « Assassins », Willey insiste sur l’habileté politique et militaire des Ismailiens qui, grâce à la personnalité avisée et charismatique de chefs..

Eagle’s Nest. Ismaili Castles in Iran and Syria. London, I.B. Tauris Publishers en association avec The Institute of Islamili Studies, 2005, 321 p., 40 ill. coul.

L’ouvrage se décompose en deux parties. La première constitue une introduction historique où l’A. retrace les débuts de la communauté ismalienne nizarite et sa montée en puissance jusqu’à la défaite face aux Mongols en 1256, en s’appuyant principalement sur les publications récentes de Farhad Daftary. Contre la vision fantasmée occidentale des fameux « Assassins », Willey insiste sur l’habileté politique et militaire des Ismailiens qui, grâce à la personnalité avisée et charismatique de chefs..

Supraspinal control of locomotion

International audienceLocomotion is a basic motor function generated and controlled by genetically defined neuronal networks. The pattern of muscle synergies is generated in the spinal cord, whereas neural centers located above the spinal cord in the brainstem and the forebrain are essential for initiating and controlling locomotor movements. One such locomotor control center in the brainstem is the mesencephalic locomotor region (MLR), first discovered in cats and later found in all vertebrate species tested to date. Over the last years, we have investigated the cellular mechanisms by which this locomotor region operates in lampreys. The lamprey MLR is a well-circumscribed region located at the junction between the midbrain and hindbrain. Stimulation of the MLR induces locomotion with an intensity that increases with the stimulation strength. Glutamatergic and cholinergic monosynaptic inputs from the MLR are responsible for excitation of reticulospinal (RS) cells that in turn activate the spinal locomotor networks. The inputs are larger in the rostral than in the caudal hindbrain RS cells. MLR stimulation on one side elicits symmetrical excitatory inputs in RS cells on both sides, and this is linked to bilateral projections of the MLR to RS cells. In addition to its inputs to RS cells, the MLR activates a well-defined group of muscarinoceptive cells in the brainstem that feeds back strong excitation to RS cells in order to amplify the locomotor output. Finally, the MLR gates sensory inputs to the brainstem through a muscarinic mechanism. It appears therefore that the MLR not only controls locomotor activity but also filters sensory influx during locomotion

A neuronal substrate for a state-dependent modulation of sensory inputs in the brainstem

International audienceCentral networks modulate sensory transmission during motor behavior. Sensory inputs may thus have distinct impacts according to the state of activity of the central networks. Using an in-vitro isolated lamprey brainstem preparation, we investigated whether a brainstem locomotor center, the mesencephalic locomotor region (MLR), modulates sensory transmission. The synaptic responses of brainstem reticulospinal (RS) cells to electrical stimulation of the sensory trigeminal nerve were recorded before and after electrical stimulation of the MLR. The RS cell synaptic responses were significantly reduced by MLR stimulation and the reduction of the response increased with the stimulation intensity of the MLR. Bath perfusion of atropine prevented the depression of sensory transmission, indicating that muscarinic receptor activation is involved. Previous studies have shown that, upon stimulation of the MLR, behavioral activity switches from a resting state to an active-locomotor state. Therefore, our results suggest that a state-dependent modulation of sensory transmission to RS cells occurs in the behavioral context of locomotion and that muscarinic inputs from the MLR are involved

Serotonergic modulation of sacral dorsal root stimulation-induced locomotor output in newborn rat

International audienceDescending neuromodulators from the brainstem play a major role in the development and regulation of spinal sensorimotor functions. Here, the contribution of serotonergic signaling in the lumbar spinal cord was investigated in the context of the generation of locomotor activity. Experiments were performed on in vitro spinal cord preparations from newborn rats (0–5 days). Rhythmic locomotor episodes (fictive locomotion) triggered by tonic electrical stimulations (2Hz, 30s) of a single sacral dorsal root were recorded from bilateral flexor-dominated (L2) and extensor-dominated (L5) ventral roots. We found that the activity pattern induced by sacral stimulation evolves over the 5 post-natal (P) day period. Although alternating rhythmic flexor-like motor bursts were expressed at all ages, the locomotor pattern of extensor-like bursting was progressively lost from P1 to P5. At later stages, serotonin (5-HT) and quipazine (5-HT2A receptor agonist) at concentrations sub-threshold for direct locomotor network activation promoted sacral stimulation-induced fictive locomotion. The 5-HT2A receptor antagonist ketanserin could reverse the agonist's action but was ineffective when fictive locomotion was already expressed in the absence of 5-HT (mainly before P2). Although inhibiting 5-HT7 receptors with SB266990 did not affect locomotor pattern organization, activating 5-HT1A receptors with 8-OH-DPAT specifically deteriorated extensor phase motor burst activity. We conclude that during the first 5 post-natal days in rat, serotonergic signaling in the lumbar cord becomes increasingly critical for the expression of fictive locomotion. Our findings therefore further underline the importance of both descending serotonergic and sensory afferent pathways in shaping locomotor activity during postnatal development