Facial Point Detection using Boosted Regression and Graph Models

Finding fiducial facial points in any frame of a video showing rich naturalistic facial behaviour is an unsolved problem. Yet this is a crucial step for geometric-featurebased facial expression analysis, and methods that use appearance-based features extracted at fiducial facial point locations. In this paper we present a method based on a combination of Support Vector Regression and Markov Random Fields to drastically reduce the time needed to search for a point’s location and increase the accuracy and robustness of the algorithm. Using Markov Random Fields allows us to constrain the search space by exploiting the constellations that facial points can form. The regressors on the other hand learn a mapping between the appearance of the area surrounding a point and the positions of these points, which makes detection of the points very fast and can make the algorithm robust to variations of appearance due to facial expression and moderate changes in head pose. The proposed point detection algorithm was tested on 1855 images, the results of which showed we outperform current state of the art point detectors

Measuring Intergenerational Mobility and Equality of Opportunity

This paper explores the link between the measurement of intergenerational mobility and the notion of equality of opportunity. We show how recently proposed theories of equality of opportunity can be meaningfully adapted to the intergenerational context. This throws a new light on the interpretation of existing mobility measures: these may be interesting to measure mobility as movement, but they are inadequate to capture the notion of equality of opportunity. We propose some new mobility measures, which start from the idea that the intergenerational transition matrix gives useful information about the opportunity sets of the children of different social classes. These measures are used in an empirical illustration to evaluate the degree of inequality of opportunity in the US, Great Britain and Italy.

Measuring Intergenerational Mobility and Equality of Opportunity

This paper explores the link between the measurement of intergenerational mobility and the notion of equality of opportunity. We show how recently proposed theories of equality of opportunity can be meaningfully adapted to the intergenerational context. This throws a new light on the interpretation of existing mobility measures: these may be interesting to measure mobility as movement, but they are inadequate to capture the notion of equality of opportunity. We propose some new mobility measures, which start from the idea that the intergenerational transition matrix gives useful information about the opportunity sets of the children of different social classes. These measures are used in an empirical illustration to evaluate the degree of inequality of opportunity in the US, Great Britain and Italy.

Measuring intergenerational mobility and equality of opportunity.

This paper explores the link between the measurement of intergenerational mobility and the notion of equality of opportunity. We show how recently proposed theories of equality of opportunity can be meaningfully adapted to the intergenerational context. This throws a new light on the interpretation of existing mobility measures: these may be interesting to measure mobility as movement, but they are inadequate to capture the notion of equality of opportunity. We propose some new mobility measures, which start from the idea that the intergenerational transition matrix gives useful information about the opportunity sets of the children of different social classes. These measures are used in an empirical illustration to evaluate the degree of inequality of opportunity in the US, Great Britain and Italy.

Development of New Radiotracers for PET Imaging of Adrenomedullin and Angiotensin II Type 1 Receptors

Les récepteurs de l'adrénomédulline sont fortement exprimés dans les capillaires alvéolaires humains et fournissent une cible moléculaire pour l'imagerie de la circulation et de l'embolie pulmonaire. Au cours des années précédentes, le dérivé DFH12 marqué au 99mTc (PulmoBind) a démontré son potentiel en tant qu'agent d'imagerie SPECT de l'hypertension pulmonaire dans des études cliniques de phase I et II. L’objectif principal de mon projet est de développer le nouvel analogue DFH17 pour l’imagerie TEP des récepteurs de l'adrénomédulline via la méthode de l’Al18F. Pour atteindre cet objectif, un système d’élution semi-automatique a été conçu pour produire l’Al18F concentré directement dans le vial de réaction. En utilisant des tests de complexation avec le chélateur NOTA, des conditions optimales ont été trouvées pour le radiomarquage du DFH17 avec l’Al18F. La combinaison du rapport Al/DFH17 1:3 dans l'éthanol 50% a permis de produire le [18F]AlF-DFH17 avec des puretés radiochimiques et chimiques élevées. Les études TEP avec le [18F]AlF-DFH17 ont démontré un rapport élevé poumon-bruit de fond ainsi qu’une grande stabilité in vivo chez le rat, le chien et le primate. Des captations différenciées dans les poumons des trois espèces ont aussi été détectées par imagerie TEP et leurs différences ont été associées à des variations de la composant RAMP2. Compte tenu de l’importante captation pulmonaire, de la stabilité in vivo et de la dosimétrie favorable, le nouveau dérivé [18F]AlF-DFH17 est un excellent candidat potentiel en tant que traceur TEP des récepteurs adrénomédulline humains. L’expression des récepteurs AT1 de l’angiotensine II est altérée dans plusieurs maladies cardiovasculaires et rénales, telles la défaillance cardiaque, rénale et l’hypertension ainsi que dans certains cancers. Auparavant, le dérivé [11C]méthyl-Candesartan a démontré un potentiel comme agent d'imagerie TEP de l'AT1R rénal mais une proportion élevée du signal TEP correspondait à une liaison non-spécifique d'un radiométabolite hydrophobe. Dans ce travail, l’objectif principal est de développer le nouveau dérivé [18F]fluorobenzyl-Candesartan en utilisant le 4[18F]fluoroiodobenzène ([18F]FIB) avec un profil métabolique et de biodistribution potentiellement meilleurs. Pour atteindre cet objectif, des paramètres réactionnels de fluorination tels que le solvant, la quantité de précurseur, le catalyseur et la température ont été optimisés permettant la radiosynthèse du [18F]FIB avec des rendements et pureté élevés. Ensuite, le couplage du [18F]FIB au dérivé alcyne-trityl-Candesartan a été évalué en utilisant la réaction de Sonogashira suivie d'une détritylation acide. Suite à l’étude de plusieurs conditions de couplage, le rendement de radioconversion a été légèrement augmenté en utilisant le catalyseur Pd(PPh3)4/CuI et K2CO3 comme base. Les meilleures conditions de fluorination et de couplage ont été automatisées pour le module de synthèse Synthra® RNPlus Research. La production du [18F]FB-Candesartan été atteinte avec de faibles rendements et activités molaires en raison de la formation d’impuretés ayant des structures et temps de rétention par HPLC similaires à ceux de notre traceur. Des études supplémentaires afin d'améliorer le rendement, la purification par HPLC et l'activité molaire se sont avérées infructueuses pour l’instant. D’autres expériences devront être effectuées à cette fin. En conclusion, l'utilisation de la réaction de Sonogashira pour produire le [18F]FB-Candersartan avec des rendements et des activités molaires élevées s'est avérée difficile.Adrenomedullin receptors are highly expressed in human alveolar capillaries and provide a molecular target for imaging the integrity of pulmonary microcirculation. In previous years, the 99mTc-labeled DFH12 derivative (PulmoBind) demonstrated its potential as a SPECT imaging agent of pulmonary hypertension in phase I and II clinical trials. In this work, we aimed to develop a NOTA-derivatized adrenomedullin analog (DFH17), radiolabeled with aluminum fluoride ([18F]AlF), for PET imaging of pulmonary microcirculation. To achieve this goal, highly concentrated [18F](AlF)2+ was produced from purified 18F using a semi-automatic system. Using inexpensive complexation assays with NOTA, optimal conditions at each step of the process were determined facilitating the radiolabeling optimization of DFH17. Furthermore, combining the Al-to-DFH17 1:3 ratio in 50% ethanol as co-solvent, allowed [18F]AlF-DFH17 production in high radiochemical and chemical purities. PET/CT and biodistribution demonstrated high [18F]AlF-DFH17 lung-to-background ratio and in vivo stability in rats, dog and primate. Contrasted inter-species uptake in the lungs associated with variations of RAMP2 were also detected by PET imaging. Considering high lung uptake, in vivo stability and favorable dosimetry observed in the monkey, the novel AM derivative [18F]AlF-DFH17 exhibits an excellent potential as a PET tracer of human AM receptors. Alterations of the expression levels of AT1R has been linked to cardiac and renal diseases, such as cardiac and renal failures, hypertension and some type of cancers. Previously, [11C]methyl-Candesartan displayed potential for PET imaging of AT1Rs, but a high proportion of PET signal corresponded to non-specific binding from a 11C-labeled hydrophobic metabolite. In this work, the main objective was to develop the novel derivative [18F]fluorobenzyl-Candesartan, with potentially better metabolic profile and biodistribution, using 4-[18F]fluoroidobenzene ([18F]FIB) as prosthetic group. To pursue this goal, radiofluorination parameters such as solvent, amount of precursor, type of catalyst and temperature were optimized to reliably synthesize [18F]FIB in high yield and purity. Coupling of [18F]FIB to the alkyne-trityl-Candesartan was evaluated using the Sonogashira cross-coupling reaction followed by an acid deprotection. After studying several Pd-cross-coupling conditions, the radioconversion yield was slightly increased by means of a Pd(PPh3)4/CuI catalyst and K2CO3 as base in DMF. Therefore, the best reaction conditions for [18F]FIB fluorination and its coupling to alkyne-Candesartan followed by an acid hydrolysis, was fully automated for Synthra® RNPlus Research synthesis module. In general, the synthesis of [18F]FB-Candesartan was achieved in low yields and molar activities due to the formation of structurally-close by-product(s) with similar HPLC retention time. Additional studies to further improve the yield, HPLC purification and molar activity (MA) have been unsuccessful. Other experiments will need to be performed to this end. In conclusion, the use of Sonogashira cross-coupling reaction to produce [18F]FB-Candesartan in high yields and molar activities was found to be challenging

Precision Measurement of the W-Boson Mass: Theoretical Contributions and Uncertainties

We perform a comprehensive analysis of electroweak, QED and mixed QCD-electroweak corrections underlying the precise measurement of the W-boson mass M_W at hadron colliders. By applying a template fitting technique, we detail the impact on M_W of next-to-leading order electroweak and QCD corrections, multiple photon emission, lepton pair radiation and factorizable QCD-electroweak contributions. As a by-product, we provide an up-to-date estimate of the main theoretical uncertainties of perturbative nature. Our results can serve as a guideline for the assessment of the theoretical systematics at the Tevatron and LHC and allow a more robust precision measurement of the W-boson mass at hadron colliders.Comment: 51 pages, 10 figures and 16 tables. Minor corrections: new citations and reference to the svn revisions of the POWHEG code. Numerical results and conclusions unchange

Terrestrial Carbonaceous Debris Tracing Atmospheric Hypervelocity-Shock Aeroplasma Processes

International audienceAtmospheric hypervelocity impacts are widely viewed to produce the meteoric smoke layer by the shock-less interactions of the impinging air molecules with the vaporized meteoroid. In contrast here, we intend to show how gas and solid aerosols when captured in the Mach cone of a bolide while entering the Earth atmosphere are transformed into a new range of polymeric nanomaterials. Carbonaceous materials from natural situations are studied from collect in a pilot region of Southern France in the following days of a high altitude meteor atmospheric airburst on 2011 August 2 nd and since the 2013 February 15 th Chelyabinsk meteoritic event in Ural. These materials are compared to the ones obtained by hypervelocity shock with the CEA Persephone light-gas gun. A numerical simulation with the Tycho software is performed to model the evolution of the increase of density directly in the rear front of the shockwave with the increase of velocity around an obstacle for high velocity inflow. The multidisciplinary approach reveals the production carbon-based nanosolids from terrestrial precursors by hypervelocity plasma particle deposition (HPPD) processes. The Tycho simulation helps to establish the lack of mixing between the ablation smoke and the surrounding atmosphere. The correlation between the simulation, the hypervelocity experiments and the natural situations shows the distinctive characteristics of visco-elastic filamentary nanosolids formed in the laminar domain of low pressure, the ones of nanoparticle-rich stiff film specific to the thin domain of high shear stress and the ones of dense glassy carbon with nanocarbon crystallites (graphite and graphene-like) only formed in the frontal high temperature and pressure domain. Data on the natural carbon-based nanosolids indicate that the atmospheric shock-dissociation occurred from a carbon pool dominated by dead atmospheric carbon. Diagnostic keys are provided to distinguish natural carbon-based nanosolids synthesized by HPPD just at the time of the hypervelocity atmospheric entry from their subsequent transformations during atmospheric transport by other aeroplasma processes

Learning to transfer: transferring latent task structures and its application to person-specific facial action unit detection

In this article we explore the problem of constructing person-specific models for the detection of facial Action Units (AUs), addressing the problem from the point of view of Transfer Learning and Multi-Task Learning. Our starting point is the fact that some expressions, such as smiles, are very easily elicited, annotated, and automatically detected, while others are much harder to elicit and to annotate. We thus consider a novel problem: all AU models for the tar- get subject are to be learnt using person-specific annotated data for a reference AU (AU12 in our case), and no data or little data regarding the target AU. In order to design such a model, we propose a novel Multi-Task Learning and the associated Transfer Learning framework, in which we con- sider both relations across subjects and AUs. That is to say, we consider a tensor structure among the tasks. Our approach hinges on learning the latent relations among tasks using one single reference AU, and then transferring these latent relations to other AUs. We show that we are able to effectively make use of the annotated data for AU12 when learning other person-specific AU models, even in the absence of data for the target task. Finally, we show the excellent performance of our method when small amounts of annotated data for the target tasks are made available