CMB Polarization: Scientific Case and Data Analysis Issues

We review the science case for studying CMB polarization. We then discuss the main issues related to the analysis of forth-coming polarized CMB data, such as those expected from balloon-borne (e.g. BOOMERanG) and satellite (e.g. Planck) experiments.Comment: 6 pages, 4 figures. To appear in "Astrophysical Polarized Background" Workshop Proceedings, eds. S. Cecchini, S. Cortiglioni, R. Sault and C. Sbarra, AIP, in pres

Forecasting isocurvature models with CMB lensing information: axion and curvaton scenarios

Some inflationary models predict the existence of isocurvature primordial fluctuations, in addition to the well known adiabatic perturbation. Such mixed models are not yet ruled out by available data sets. In this paper we explore the possibility of obtaining better constraints on the isocurva- ture contribution from future astronomical data. We consider the axion and curvaton inflationary scenarios, and use Planck satellite experimental specifications together with SDSS galaxy survey to forecast for the best parameter error estimation by means of the Fisher information matrix formal- ism. In particular, we consider how CMB lensing information can improve this forecast. We found substantial improvements for all the considered cosmological parameters. In the case of isocurvature amplitude this improvement is strongly model dependent, varying between less than 1% and above 20% around its fiducial value. Furthermore, CMB lensing enables the degeneracy break between the isocurvature amplitude and correlation phase in one of the models. In this sense, CMB lensing information will be crucial in the analysis of future data.Comment: Accepted for publication in PR

Pattern selection in growing tubular tissues

International audienceTubular organs display a wide variety of surface morphologies including circumferential and longitudinal folds, square and hexagonal undulations, and finger-type protrusions. Surface morphology is closely correlated to tissue function and serves as a clinical indicator for physiological and pathological conditions, but the regulators of surface morphology remain poorly understood. Here, we explore the role of geometry and elasticity on the formation of surface patterns. We establish morphological phase diagrams for patterns selection and show that increasing the thickness or stiffness ratio between the outer and inner tubular layers induces a gradual transition from circumferential to longitudinal folding. Our results suggest that physical forces act as regulators during organogenesis and give rise to the characteristic circular folds in the esophagus, the longitudinal folds in the valves of Kerckring, the surface networks in villi, and the crypts in the large intestine

Searching for a dipole modulation in the large-scale structure of the Universe

Several statistical anomalies in the CMB temperature anisotropies seem to defy the assumption of a homogeneous and isotropic universe. In particular, a dipole modulation has been detected both in WMAP and Planck data. We adapt the methodology proposed by Eriksen et al. (2007) on CMB data to galaxy surveys, tracing the large-scale structure. We analyse the NRAO VLA Sky Survey (NVSS) data at a resolution of ~2 degrees for three different flux thresholds: 2.5, 5.0 and 10.0 mJy respectively. No evidence of a dipole modulation is found. This result suggests that the origin of the dipole asymmetry found in the CMB cannot be assigned to secondary anisotropies produced at redshifts around z = 1. However, it could still have been generated at redshifts higher or lower, such as the integrated Sachs-Wolfe effect produced by the local structures. Other all-sky surveys, like the infrared WISE catalogue, could help to explore with a high sensitivity a redshift interval closer than the one probed with NVSS.Comment: 6 pages, 2 figures. Some minor changes have been done from the original manuscript. This paper is accepted by MNRA

Resilience framework for seaport infrastructure: theory and application

The efficient movement of goods is crucial to the economic growth of communities. This makes the existence of seaports essential for the marine transportation system. Due to their natural location, ports are continuously threatened by natural hazards such as wind action, which necessitates a continuous monitoring and assessment for their performance. The work presented here aims at assessing the resilience of ports against natural disasters. This is done by identifying the performance and the recovery rate of such infrastructure during the period following the event. The research commenced with gathering information about the port’s main components that are influenced by natural hazards. The collected data has been compiled in the form of indicators, which have been filtered and grouped under four dimensions in the proposed “PORT framework”. Each of the indicator has been allocated a measure to enable its quantitative evaluation. The aggregation of the indicators’ values allows identifying the port resilience

Sudden death after valve-in-valve procedure due to delayed coronary obstruction. A case report

Background: Valve-in-valve transcatheter aortic valve implantation for degenerated aortic bioprostheses is an effective option for patients at high risk for redo surgery, even if it may be burdened by complications more common in specific settings, such as, coronary artery obstruction. Case presentation: We present the case of a Caucasic 84-year-old woman with degeneration of a previously implanted aortic Mitroflow bioprosthesis. She underwent a valve-in-valve transcatheter aortic valve implantation with a CoreValve® bioprosthesis. End-procedure coronary angiography demonstrated maintained perfusion of both coronary arteries. However, few hours later, she experienced sudden cardiac death. An autopsy showed that Mitroflow prosthesis leaflets were higher than the left main coronary ostium, and no other possible cause for the sudden death. Fatality was thus ascribed to left main coronary ostium obstruction due to apposition of the Mitroflow leaflet pushed upward by the late expansion of CoreValve®. Conclusions: Coronary artery obstruction is a frequently fatal complication which usually presents just after valve implantation, but, as reported in our case, it may also have a delayed presentation. Accurate patient's selection and intraoperative preventive measures can reduce this eventuality