Inflammation and Atherosclerosis: State of the Art in 2004-2005

peer reviewedInflammation plays a pivotal role in atherosclerosis; being present in all steps of the pathology, from initiation to the progression of the lesions to the development of vulnerable plaques and clinical destabilisation. Therefore, systemic markers of inflammation have emerged to predict future cardiovascular events in patients initially admitted for unstable syndromes, but also in healthy subjects. These markers can identify high risk patients and they are used to adapt ideal treatment to the patient's profile. The implication of the inflammation process in the treatment strategies is described in the last part of the article

CCCP: A CCD Controller for Counting Photons

CCCP, a CCD Controller for Counting Photons, is presented. This new controller uses a totally new clocking architecture and allows to drive the CCD in a novel way. Its design is optimized for the driving of EMCCDs at up to 20MHz of pixel rate and fast vertical transfer. Using this controller, the dominant source of noise of EMCCDs at low flux level and high frame rate, the Clock Induced Charges, were reduced to 0.001 - 0.0018 electron/pixel/frame (depending of the electron multiplying gain), making efficient photon counting possible. CCCP will be deployed in 2009 on the ESO NTT through the 3D-NTT1 project and on the SOAR through the BTFI project.Comment: 10 pages, 10 figures, to appear in "Ground-based and Airborne Instrumentation for Astronomy II" SPIE conference, Marseille, 23-28 June 200

Extreme faint flux imaging with an EMCCD

An EMCCD camera, designed from the ground up for extreme faint flux imaging, is presented. CCCP, the CCD Controller for Counting Photons, has been integrated with a CCD97 EMCCD from e2v technologies into a scientific camera at the Laboratoire d'Astrophysique Experimentale (LAE), Universite de Montreal. This new camera achieves sub-electron read-out noise and very low Clock Induced Charge (CIC) levels, which are mandatory for extreme faint flux imaging. It has been characterized in laboratory and used on the Observatoire du Mont Megantic 1.6-m telescope. The performance of the camera is discussed and experimental data with the first scientific data are presented.Comment: 33 pages, 17 figures, accepted for publication in PAS

L3CCD results in pure photon counting mode

Theoretically, L3CCDs are perfect photon counting devices promising high quantum efficiency ($\sim$90%) and sub-electron readout noise ($\sigma$<0.1 e-). We discuss how a back-thinned 512x512 frame-transfer L3CCD (CCD97) camera operating in pure photon counting mode would behave based on experimental data. The chip is operated at high electromultiplication gain, high analogic gain and high frame rate. Its performance is compared with a modern photon counting camera (GaAs photocathode, QE $\sim$28%) to see if L3CCD technology, in its current state, could supersede photocathode-based devices.Comment: 9 pages, 9 figures, to appear in SPIE conference proceedings vol 5499, "Optical & IR Detectors for Astronomy" Glasgow UK, 21-24 June 200

Algorithmes mémétiques de détection de communautés dans les réseaux complexes (techniques palliatives de la limite de résolution)

Les réseaux complexes, issus de relevés de terrain d origines trèsvariées, en biologie, science de l information ou sociologie,présentent une caractéristique remarquable dénommée structurecommunautaire. Des groupes, ou communautés, à l intérieur duréseau, ont une cohésion interne forte et des liens entre eux plusfaibles. Sans connaissance a priori du nombre de communautés, ladifficulté réside dans la caractérisation d un bon partitionnement encommunautés. La modularité est une mesure globale de qualité departitionnement très utilisée qui capture les contraintes de cohésioninterne forte et de liens externes faibles. Elle transforme le problèmede détection de communautés en problème d optimisationNP-difficile. Elle souffre d un défaut, la limite de résolution, qui tendà rendre indétectables les très petites communautés d autant plusque le réseau est grand. L algorithme le plus efficace pour optimiserla modularité, dit de Louvain, procède par fusion de communautés.Cette thèse s attache à modifier cet algorithme pour qu il réalisemajoritairement des fusions pertinentes, qui n aggravent pas lalimite de résolution, en utilisant une condition de fusion. De plus, enl associant à un algorithme mémétique, les partitions proposéessont très proches des partitions attendues pour des graphesgénérés par un modèle qui reproduit les caractéristiques desréseaux complexes. Enfin, cet algorithme mémétique réduitfortement l inconsistance de solution, défaut de la modularité selonlequel deux partitions trouvées à partir d un examen des noeudsdans un ordre aléatoire, pour le même graphe, peuvent êtrestructurellement très différentes, rendant leur interprétation délicate.From various applications, in sociology or biology for instance,complex networks exhib the remarquable property of communitystructure. Groups, sometimes called communities, has a stronginternal cohesion and poor links between them. Whithout priorknowledge of the number of communities, the difficulty lies in thecharacterization of a good clustering. Modularity is an overallmeasure of clustering quality widely used to capture the doubleconstraint, internal and external, of well formed communities. Theproblem became a NP-hard optimization problem. The main weakof modularity is the resolution limit, which tends to makeundetectable very small communities especially as the network islarge. The algorithm of Louvain, one of the most efficient one tooptimize modularity, proceeds by merging communities. This thesisattempts to modify the algorithm so that it mainly produces relevantmerges that do not make worse the effects of resolution limit, usinga merge condition. In addition, by combining it with a memeticalgorithm, proposed clusterings are very close to the expected onesfor graphs generated by a model that reproduces the characteristicsof complex networks. Finally, the memetic algorithm greatly reducesthe inconsistency of solution, another weakness of modularity suchthat, for the same graph, two partitions found from an exploration ofnodes in a random order can be structurally very different, makingthem difficult to interpret.LE MANS-BU Sciences (721812109) / SudocSudocFranceF

Spiral inflow feeding the nuclear starburst in M83, observed in H-alpha emission with the GHAFAS Fabry-Perot interferometer

We present observations of the nearby barred starburst galaxy, M83 (NGC5236), with the new Fabry-Perot interferometer GHAFAS mounted on the 4.2 meter William Herschel Telescope on La Palma. The unprecedented high resolution observations, of 16 pc/FWHM, of the H-alpha-emitting gas cover the central two kpc of the galaxy. The velocity field displays the dominant disk rotation with signatures of gas inflow from kpc scales down to the nuclear regions. At the inner Inner Lindblad Resonance radius of the main bar and centerd at the dynamical center of the main galaxy disk, a nuclear $5.5 (\pm 0.9) \times 10^8 M_\odot$ rapidly rotating disk with scale length of $60 \pm 20$ pc has formed. The nuclear starburst is found in the vicinity as well as inside this nuclear disk, and our observations confirm that gas spirals in from the outer parts to feed the nuclear starburst, giving rise to several star formation events at different epochs, within the central 100 pc radius of M83.Comment: Accepted for publication in ApJ Letters. High-resolution version can be found at http://www.astro.su.se/~kambiz/DOC/paper-M83.pd

Coronary chronic total occlusion intervention: utility or futility.

peer reviewedINTRODUCTION: Despite an incidence of about 18-52% of the patients undergoing coronary angiography, chronic total occlusions (CTO) are rarely revascularised by percutaneous angioplasty (PCI). Nevertheless, current evidence suggests that successful CTO angioplasty improves symptoms, quality of life and long-term survival. During the last decade, the improvement of specific tools and techniques for these complex procedures, and the increasing experience of operators, have led to the achievement of success and complication rates almost equivalent to non-CTO angioplasty. Areas covered: This review focuses on the clinical benefits of CTO revascularization and on appropriate patient selection. Expert commentary: Current evidence suggests that successful CTO-PCI improves symptoms, quality of life and long-term survival. During the last years, the improvement of specific techniques for these complex procedures and the increasing experience of operators, have led to the achievement of success and complication rates almost equivalent to non-CTO lesion angioplasty

The Brazilian Tunable Filter Imager for the SOAR telescope

This paper presents a new Tunable Filter Instrument for the SOAR telescope. The Brazilian Tunable Filter Imager (BTFI) is a versatile, new technology, tunable optical imager to be used in seeing-limited mode and at higher spatial fidelity using the SAM Ground-Layer Adaptive Optics facility at the SOAR telescope. The instrument opens important new science capabilities for the SOAR community, from studies of the centers of nearby galaxies and the insterstellar medium to statistical cosmological investigations. The BTFI takes advantage of three new technologies. The imaging Bragg Tunable Filter concept utilizes Volume Phase Holographic Gratings in a double-pass configuration, as a tunable filter, while a new Fabry-Perot (FP) concept involves technologies which allow a single FP etalon to act over a large range of interference orders and spectral resolutions. Both technologies will be in the same instrument. Spectral resolutions spanning the range between 25 and 30,000 can be achieved through the use of iBTF at low resolution and scanning FPs beyond R ~2,000. The third new technologies in BTFI is the use of EMCCDs for rapid and cyclically wavelength scanning thus mitigating the damaging effect of atmospheric variability through data acquisition. An additional important feature of the instrument is that it has two optical channels which allow for the simultaneous recording of the narrow-band, filtered image with the remaining (complementary) broad-band light. This avoids the uncertainties inherent in tunable filter imaging using a single detector. The system was designed to supply tunable filter imaging with a field-of-view of 3 arcmin on a side, sampled at 0.12" for direct Nasmyth seeing-limited area spectroscopy and for SAM's visitor instrument port for GLAO-fed area spectroscopy. The instrument has seen first light, as a SOAR visitor instrument. It is now in comissioning phase.Comment: accepted in PAS

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

Familial hypercholesterolaemia in children and adolescents from 48 countries: a cross-sectional study

Background: Approximately 450 000 children are born with familial hypercholesterolaemia worldwide every year, yet only 2·1% of adults with familial hypercholesterolaemia were diagnosed before age 18 years via current diagnostic approaches, which are derived from observations in adults. We aimed to characterise children and adolescents with heterozygous familial hypercholesterolaemia (HeFH) and understand current approaches to the identification and management of familial hypercholesterolaemia to inform future public health strategies. Methods: For this cross-sectional study, we assessed children and adolescents younger than 18 years with a clinical or genetic diagnosis of HeFH at the time of entry into the Familial Hypercholesterolaemia Studies Collaboration (FHSC) registry between Oct 1, 2015, and Jan 31, 2021. Data in the registry were collected from 55 regional or national registries in 48 countries. Diagnoses relying on self-reported history of familial hypercholesterolaemia and suspected secondary hypercholesterolaemia were excluded from the registry; people with untreated LDL cholesterol (LDL-C) of at least 13·0 mmol/L were excluded from this study. Data were assessed overall and by WHO region, World Bank country income status, age, diagnostic criteria, and index-case status. The main outcome of this study was to assess current identification and management of children and adolescents with familial hypercholesterolaemia. Findings: Of 63 093 individuals in the FHSC registry, 11 848 (18·8%) were children or adolescents younger than 18 years with HeFH and were included in this study; 5756 (50·2%) of 11 476 included individuals were female and 5720 (49·8%) were male. Sex data were missing for 372 (3·1%) of 11 848 individuals. Median age at registry entry was 9·6 years (IQR 5·8-13·2). 10 099 (89·9%) of 11 235 included individuals had a final genetically confirmed diagnosis of familial hypercholesterolaemia and 1136 (10·1%) had a clinical diagnosis. Genetically confirmed diagnosis data or clinical diagnosis data were missing for 613 (5·2%) of 11 848 individuals. Genetic diagnosis was more common in children and adolescents from high-income countries (9427 [92·4%] of 10 202) than in children and adolescents from non-high-income countries (199 [48·0%] of 415). 3414 (31·6%) of 10 804 children or adolescents were index cases. Familial-hypercholesterolaemia-related physical signs, cardiovascular risk factors, and cardiovascular disease were uncommon, but were more common in non-high-income countries. 7557 (72·4%) of 10 428 included children or adolescents were not taking lipid-lowering medication (LLM) and had a median LDL-C of 5·00 mmol/L (IQR 4·05-6·08). Compared with genetic diagnosis, the use of unadapted clinical criteria intended for use in adults and reliant on more extreme phenotypes could result in 50-75% of children and adolescents with familial hypercholesterolaemia not being identified. Interpretation: Clinical characteristics observed in adults with familial hypercholesterolaemia are uncommon in children and adolescents with familial hypercholesterolaemia, hence detection in this age group relies on measurement of LDL-C and genetic confirmation. Where genetic testing is unavailable, increased availability and use of LDL-C measurements in the first few years of life could help reduce the current gap between prevalence and detection, enabling increased use of combination LLM to reach recommended LDL-C targets early in life