Rôle du toll-like receptor 4 (TLR4) immun dans le développement de la fibrose du tissu adipeux

Ce manuscrit est principalement axé sur le rôle du Toll-like Receptor 4 (TLR4) immun dans le développement de la fibrose du tissu adipeux. Récepteur de l'immunité innée dont le ligand naturel est le lipopolysaccharide (LPS), le TLR4 a été impliqué dans la fibrogenèse de différents tissus tels que le foie et le rein. Afin de mettre en évidence les mécanismes de genèse de la fibrose dans le tissu adipeux, nous avons travaillé avec des souris C3H/HeJ, modèle de mutation ponctuelle/perte de fonction du TLR4 et leurs contrôles C3H/HeOuJ. L'utilisation d'un régime hyperlipidique, inducteur d'inflammation et de fibrose dans ce modèle, ainsi que l'utilisation d'une expérience d'irradiation/reconstitution de moelle osseuse, nous a permis d'identifier le rôle clé du TLR4 immun dans la mise en place de la fibrose adipeuse. Nous avons également montré l'apparition d'une dysfonction lipolytique du tissu adipeux accompagnée d'une importante mort adipocytaire avec l'apparition de cette fibrose. En deuxième partie de ce manuscrit, nous avons regardé la régulation des lipases du muscle squelettique au cours d'un régime gras in vivo. Une précédente publication du laboratoire, dans un modèle in vitro, a montré le rôle néfaste pour le signal insulinique d'une dérégulation de l'expression des deux principales lipases de la lipolyse, via l'accumulation de diacylglycérols (DAG). Dans ce contexte nous avons voulu vérifier ces résultats in vivo. Pour cela nous avons mis des souris C3H/HeOuJ en régime standard ou en régime riche en lipides durant 4 semaines. L'étude de différents acteurs de la voie de l'insuline ainsi que des lipases musculaires nous a permis de confirmer les résultats in vitro précédemment obtenus dans un modèle in vivo.In a first part, the study focuses on the implication of the immune Toll-like Receptor 4 (TLR4) in adipose tissue fibrosis. The natural ligand of this innate immunity receptor is lipopolysaccharide (LPS). In many studies, TLR4 was involved in fibrogenesis in various tissues such as liver and kidney. To highlight the mechanisms of fibrogenesis in adipose tissue, we worked with C3H/HeJ mice which carry a missense mutation in the TLR4 gene and C3H/HeOuJ as controls. The use of a high fat diet, inducing inflammation and fibrosis in this model, as well as an irradiation/bone marrow reconstitution experiment, which allowed us to identified the key role of the immune TLR4 in the genesis of adipose tissue fibrosis. We also showed the appearance of a lipolytic adipose tissue dysfunction accompanied by adipocyte death with the appearance of adipose tissue fibrosis. In the second part of this thesis, we looked at the regulation of skeletal muscle lipases during a high fat diet in mice. A previous publication of the laboratory, done in an in vitro model, showed the negative impact on insulin signaling of the dysregulation of the expression of two major lipases, though diacylglycerol (DAG) accumulation. In this context we wanted to verify these results in vivo. We used C3H/HeOuJ mice on standard diet or high fat diet for 4 weeks. The study of different actors in insulin signaling and muscle lipases has allowed us to confirm in vivo results previously obtained

Avant-propos et introduction

Présentation des problématiques et des articles contenus dans le livre "La Chasse. Pratiques sociales et symboliques", de Boccard, 2006

Personal exposure to radiofrequency electromagnetic fields in various occupations in Spain and France

BACKGROUND: A preliminary job-exposure matrix (JEM) for radiofrequency electromagnetic fields (RF-EMF) was created based on self-reported occupational information from a multi-country population-based study of approximately 10,000 participants combined with available measurement data compiled in a source-exposure matrix (spot measurements). In order to address the limited personal occupational RF-EMF measurement data available in the literature, we performed a measurement campaign among workers in various occupations in Spain and France. METHODS: Personal full-shift measurements were conducted using RadMan 2XT™ (Narda) devices. A worker diary was used to capture information on occupational and background sources of RF exposure during the shift. Inclusion of occupations to be measured was initially based on exposure prevalence and level information in the preliminary JEM and expert judgment. RESULTS: Personal full-shift measurements were conducted among 333 workers representing 46 ISCO88 occupations. Exposure to electric (E) and magnetic (H) fields was infrequent with >99% of measurements below the detection limit of the device (≥1% of the 1998 ICNIRP standards). A total of 50.2% and 77.2% of workers were ever exposed to E and H fields respectively (having at least one recorded 1-second measurement above the detection limit). Workers in elementary occupations, technicians and associate professionals, plant and machine operators and assemblers had somewhat greater numbers of measurements above the detection limit, higher maximum values and longer exposure durations. A small proportion of measurements were ≥100% of the standards, though these exceedances were brief (generally a few seconds in duration). Female workers and workers reporting use of any RF-EMF emitting source were more likely to have a measured exposure to E and H fields. CONCLUSION: We conducted personal RF-EMF measurements among workers in various occupations in Spain and France. Overall, RF-EMF exposure ≥1 % ICNIRP was infrequent, despite some intermittent exposures ≥100% observed among workers in some occupations

Ferroelectric Domain Walls in PbTiO3 Are Effective Regulators of Heat Flow at Room Temperature

Achieving efficient spatial modulation of phonon transmission is an essential step on the path to phononic circuits using "phonon currents". With their intrinsic and reconfigurable interfaces, domain walls (DWs), ferroelectrics are alluring candidates to be harnessed as dynamic heat modulators. This paper reports the thermal conductivity of single-crystal PbTiO thin films over a wide variety of epitaxial-strain-engineered ferroelectric domain configurations. The phonon transport is proved to be strongly affected by the density and type of DWs, achieving a 61% reduction of the roomerature thermal conductivity compared to the single-domain scenario. The thermal resistance across the ferroelectric DWs is obtained, revealing a very high value (≈5.0 × 10 K m W), comparable to grain boundaries in oxides, explaining the strong modulation of the thermal conductivity in PbTiO. This low thermal conductance of the DWs is ascribed to the structural mismatch and polarization gradient found between the different types of domains in the PbTiO films, resulting in a structural inhomogeneity that extends several unit cells around the DWs. These findings demonstrate the potential of ferroelectric DWs as efficient regulators of heat flow in one single material, overcoming the complexity of multilayers systems and the uncontrolled distribution of grain boundaries, paving the way for applications in phononics

Optimasi Portofolio Resiko Menggunakan Model Markowitz MVO Dikaitkan dengan Keterbatasan Manusia dalam Memprediksi Masa Depan dalam Perspektif Al-Qur`an

Risk portfolio on modern finance has become increasingly technical, requiring the use of sophisticated mathematical tools in both research and practice. Since companies cannot insure themselves completely against risk, as human incompetence in predicting the future precisely that written in Al-Quran surah Luqman verse 34, they have to manage it to yield an optimal portfolio. The objective here is to minimize the variance among all portfolios, or alternatively, to maximize expected return among all portfolios that has at least a certain expected return. Furthermore, this study focuses on optimizing risk portfolio so called Markowitz MVO (Mean-Variance Optimization). Some theoretical frameworks for analysis are arithmetic mean, geometric mean, variance, covariance, linear programming, and quadratic programming. Moreover, finding a minimum variance portfolio produces a convex quadratic programming, that is minimizing the objective function ðð¥with constraintsð ð 𥠥 ðandð´ð¥ = ð. The outcome of this research is the solution of optimal risk portofolio in some investments that could be finished smoothly using MATLAB R2007b software together with its graphic analysis

Search for heavy resonances decaying to two Higgs bosons in final states containing four b quarks

A search is presented for narrow heavy resonances X decaying into pairs of Higgs bosons (H) in proton-proton collisions collected by the CMS experiment at the LHC at root s = 8 TeV. The data correspond to an integrated luminosity of 19.7 fb(-1). The search considers HH resonances with masses between 1 and 3 TeV, having final states of two b quark pairs. Each Higgs boson is produced with large momentum, and the hadronization products of the pair of b quarks can usually be reconstructed as single large jets. The background from multijet and t (t) over bar events is significantly reduced by applying requirements related to the flavor of the jet, its mass, and its substructure. The signal would be identified as a peak on top of the dijet invariant mass spectrum of the remaining background events. No evidence is observed for such a signal. Upper limits obtained at 95 confidence level for the product of the production cross section and branching fraction sigma(gg -> X) B(X -> HH -> b (b) over barb (b) over bar) range from 10 to 1.5 fb for the mass of X from 1.15 to 2.0 TeV, significantly extending previous searches. For a warped extra dimension theory with amass scale Lambda(R) = 1 TeV, the data exclude radion scalar masses between 1.15 and 1.55 TeV

The James Webb Space Telescope Mission

Twenty-six years ago a small committee report, building on earlier studies, expounded a compelling and poetic vision for the future of astronomy, calling for an infrared-optimized space telescope with an aperture of at least $4m$. With the support of their governments in the US, Europe, and Canada, 20,000 people realized that vision as the $6.5m$ James Webb Space Telescope. A generation of astronomers will celebrate their accomplishments for the life of the mission, potentially as long as 20 years, and beyond. This report and the scientific discoveries that follow are extended thank-you notes to the 20,000 team members. The telescope is working perfectly, with much better image quality than expected. In this and accompanying papers, we give a brief history, describe the observatory, outline its objectives and current observing program, and discuss the inventions and people who made it possible. We cite detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space Telescope Overview, 29 pages, 4 figure

Search for supersymmetry in events with one lepton and multiple jets in proton-proton collisions at root s=13 TeV

Peer reviewe