Comparison of the Automated Oscillometric Method With the Gold Standard Doppler Ultrasound Method to Access the Ankle-Brachial Pressure Index

Objective: Despite its screening interest, the ankle-brachial pressure index (ABPI) remains uncommon in general practice, because it needs training and specific devices as Doppler. Easier methods such as the use of automated oscillometric devices may facilitate the peripheral arterial diseases (PADs) screening. We wanted to assess the reliability of the automated oscillometric measurement of the ABPI, compared with the gold standard Doppler ultrasound measurement. Patients and Method: In 287 patients aged 65 years or older without diagnosed PAD, we performed ABPI measurements with oscillometric and Doppler devices. Reproducibility was assessed by the intraclass correlation coefficient of agreement (R) and the Bland and Altman method. Results: The intermethod reliability was bad (R = .346, 95% CI = (0.268-0.420)), with a large confidence interval of the individual differences between the 2 methods: 95% CI = (—0.183-0.346). Conclusion: Automatic oscillometric devices cannot be recommended as reliable methods for ABPI measurement

Monitoring edge-geodetic sets in graphs

We introduce a new graph-theoretic concept in the area of network monitoring. In this area, one wishes to monitor the vertices and/or the edges of a network (viewed as a graph) in order to detect and prevent failures. Inspired by two notions studied in the literature (edge-geodetic sets and distance-edge-monitoring sets), we define the notion of a monitoring edge-geodetic set (MEG-set for short) of a graph $G$ as an edge-geodetic set $S\subseteq V(G)$ of $G$ (that is, every edge of $G$ lies on some shortest path between two vertices of $S$) with the additional property that for every edge $e$ of $G$, there is a vertex pair $x, y$ of $S$ such that $e$ lies on \emph{all} shortest paths between $x$ and $y$. The motivation is that, if some edge $e$ is removed from the network (for example if it ceases to function), the monitoring probes $x$ and $y$ will detect the failure since the distance between them will increase. We explore the notion of MEG-sets by deriving the minimum size of a MEG-set for some basic graph classes (trees, cycles, unicyclic graphs, complete graphs, grids, hypercubes,...) and we prove an upper bound using the feedback edge set of the graph

Characterizing extremal digraphs for identifying codes and extremal cases of Bondy's theorem on induced subsets

An identifying code of a (di)graph $G$ is a dominating subset $C$ of the vertices of $G$ such that all distinct vertices of $G$ have distinct (in)neighbourhoods within $C$. In this paper, we classify all finite digraphs which only admit their whole vertex set in any identifying code. We also classify all such infinite oriented graphs. Furthermore, by relating this concept to a well known theorem of A. Bondy on set systems we classify the extremal cases for this theorem

Étude comparative tensiomètre automatique versus doppler à ultrasons dans la mesure de l’index de pression systolique à la cheville (Ipsc)

ObjectifL’évaluation de l’index de pression systolique à la cheville (IPSC) est la méthode non invasive la plus simple de dépistage de l’artériopathie des membres inférieurs (AOMI) mais reste peu usitée en pratique courante, car elle est chronophage, implique un équipement et une formation appropriés. Le but de notre étude est d’évaluer la validité et la fiabilité de la mesure de l’IPSC à l’aide d’un tensiomètre automatique par comparaison avec les résultats obtenus par doppler continu, méthode de référence. Méthodes Les patients de 65 ans et plus hospitalisés au CHU d’Angers de juillet 2008 à mars 2009 en médecine interne et n’ayant pas d’AOMI documentée au moment de l’inclusion ont participé à l’étude. Les critères d’exclusion étaient la présence d’une fibrillation auriculaire et une incompressibilité des artères distales des membres inférieurs. Pour chaque patient, l’IPSC a été évalué par tensiomètre automatique et par la méthode Doppler de référence ; ces mesures étant faites par le même examinateur. La concordance entre les deux mesures était appréciée par la méthode de Bland et Altman et le coefficient de corrélation intraclasse (ICC). Résultats Sur 287 patients participant à l’étude, 221 ont étés inclus. Cinquante-six (25 %) de ces patients avaient un IPSC < 0,90. La concordance entre les deux méthodes était médiocre : ICC à 0,35 ± 0,08 et moyenne à 0,08 ± 0,26 selon la méthode de Bland et Altman. Conclusion La méthode de dépistage de l’AOMI par mesure de l’IPSC par tensiomètre automatique ne peut être retenue comme une alternative à la méthode Doppler

Observing the high redshift universe using the VIMOS-IFU

We describe the advantages of using Integral Field Spectroscopy to observe deep fields of galaxy. The VIMOS Integral Field Unit is particularly suitable for this kind of studies thanks to its large field-of-view (~ 1 arcmin^2). After a short description of the VIMOS-IFU data reduction, we detail the main scientific issues which can be addressed using observations of the Hubble Deep Field South with a combination of Integral Field Spectroscopy and broad band optical and Near-Infrared imaging.Comment: 4 pages, accepted for publishing in AN (ref. proc. of Euro3D Science workshop, IoA Cambridge, May 2003

Galactic conformity and central/satellite quenching, from the satellite profiles of M* galaxies at 0.4 < z < 1.9 in the UKIDSS UDS

We explore the redshift evolution of a curious correlation between the star formation properties of central galaxies and their satellites (‘galactic conformity') at intermediate to high redshift (0.4 9.7, around central galaxies at the characteristic Schechter function mass, M ∼ M*. We fit the radial profiles of satellite number densities with simple power laws, finding slopes in the range −1.1 to −1.4 for mass-selected satellites, and −1.3 to −1.6 for passive satellites. We confirm the tendency for passive satellites to be preferentially located around passive central galaxies at 3σ significance and show that it exists to at least z ∼ 2. Meanwhile, the quenched fraction of satellites around star-forming galaxies is consistent with field galaxies of equal stellar masses. We find no convincing evidence for a redshift-dependent evolution of these trends. One simple interpretation of these results is that only passive central galaxies occupy an environment that is capable of independently shutting off star formation in satellite galaxies. By examining the satellites of higher stellar mass star-forming galaxies (log(M*/M⊙) > 11), we conclude that the origin of galactic conformity is unlikely to be exclusively due to the host dark matter halo mass. A halo-mass-independent correlation could be established by either formation bias or a more physical connection between central and satellite star formation histories. For the latter, we argue that a star formation (or active galactic nucleus) related outburst event from the central galaxy could establish a hot halo environment which is then capable of quenching both central and satellite galaxie

Star formation in the cluster CLG0218.3-0510 at z=1.62 and its large-scale environment: the infrared perspective

The galaxy cluster CLG0218.3-0510 at z=1.62 is one of the most distant galaxy clusters known, with a rich muti-wavelength data set that confirms a mature galaxy population already in place. Using very deep, wide area (20x20 Mpc) imaging by Spitzer/MIPS at 24um, in conjunction with Herschel 5-band imaging from 100-500um, we investigate the dust-obscured, star-formation properties in the cluster and its associated large scale environment. Our galaxy sample of 693 galaxies at z=1.62 detected at 24um (10 spectroscopic and 683 photo-z) includes both cluster galaxies (i.e. within r <1 Mpc projected clustercentric radius) and field galaxies, defined as the region beyond a radius of 3 Mpc. The star-formation rates (SFRs) derived from the measured infrared luminosity range from 18 to 2500 Ms/yr, with a median of 55 Ms/yr, over the entire radial range (10 Mpc). The cluster brightest FIR galaxy, taken as the centre of the galaxy system, is vigorously forming stars at a rate of 256$\pm$70 Ms/yr, and the total cluster SFR enclosed in a circle of 1 Mpc is 1161$\pm$96 Ms/yr. We estimate a dust extinction of about 3 magnitudes by comparing the SFRs derived from [OII] luminosity with the ones computed from the 24um fluxes. We find that the in-falling region (1-3 Mpc) is special: there is a significant decrement (3.5x) of passive relative to star-forming galaxies in this region, and the total SFR of the galaxies located in this region is lower (130 Ms/yr/Mpc2) than anywhere in the cluster or field, regardless of their stellar mass. In a complementary approach we compute the local galaxy density, Sigma5, and find no trend between SFR and Sigma5. However, we measure an excess of star-forming galaxies in the cluster relative to the field by a factor 1.7, that lends support to a reversal of the SF-density relation in CLG0218.Comment: accepted for publication in MNRAS. v2: minor correction

The Halo Mass-Bias Redshift Evolution in the Λ\LambdaCDM Cosmology

We derive an analytic model for the redshift evolution of linear-bias, allowing for interactions and merging of the mass-tracers, by solving a second order differential equation based on linear perturbation theory and the Friedmann-Lemaitre solutions of the cosmological field equations. We then study the halo-mass dependence of the bias evolution, using the dark matter halo distribution in a $\Lambda$CDM simulation in order to calibrate the free parameters of the model. Finally, we compare our theoretical predictions with available observational data and find a good agreement. In particular, we find that the bias of optical QSO's evolve differently than those selected in X-rays and that their corresponding typical dark matter halo mass is $\sim 10^{13} h^{-1} M_{\odot}$ and \magcir 5 \times 10^{13} h^{-1} M_{\odot}, respectively.Comment: 8 pages, 5 figures, accepted for publication in Ap