The faintest star forming galaxies

I briefly report on the X-ray detection of 10 radio sub-mJy sources in the 2 Ms Chandra observation of the Hubble Deep Field North region. These sources follow the same radio/X-ray luminosities relation which holds for nearby galaxies. Making use of this relation, X-ray number counts from star forming galaxies are predicted from the deep radio Log N-Log S's.Comment: 1 page, 2 figures. Proc. workshop "X-ray surveys in the light of the new observatories" held in Santander (E) 2002. LaTeX, anabs.cls include

Astrometry and exoplanets in the Gaia era: a Bayesian approach to detection and parameter recovery

(abridged) We develop Bayesian methods and detection criteria for orbital fitting, and revise the detectability of exoplanets in light of the in-flight properties of Gaia. Limiting ourselves to one-planet systems as a first step of the development, we simulate Gaia data for exoplanet systems over a grid of S/N, orbital period, and eccentricity. The simulations are then fit using Markov chain Monte Carlo methods. We investigate the detection rate according to three information criteria and the delta chi^2. For the delta chi^2, the effective number of degrees of freedom depends on the mission length. We find that the choice of the Markov chain starting point can affect the quality of the results; we therefore consider two limit possibilities: an ideal case, and a very simple method that finds the starting point assuming circular orbits. Using Jeffreys' scale of evidence, the fraction of false positives passing a strong evidence criterion is < ~0.2% (0.6%) when considering a 5 yr (10 yr) mission and using the Akaike information criterion or the Watanabe-Akaike information criterion, and <0.02% (<0.06%) when using the Bayesian information criterion. We find that there is a 50% chance of detecting a planet with a minimum S/N=2.3 (1.7). This sets the maximum distance to which a planet is detectable to ~70 pc and ~3.5 pc for a Jupiter-mass and Neptune-mass planet, respectively, assuming a 10 yr mission, a 4 au semi-major axis, and a 1 M_sun star. The period is the orbital parameter that can be determined with the best accuracy, with a median relative difference between input and output periods of 4.2% (2.9%) assuming a 5 yr (10 yr) mission. The median accuracy of the semi-major axis of the orbit can be recovered with a median relative error of 7% (6%). The eccentricity can also be recovered with a median absolute accuracy of 0.07 (0.06).Comment: 18 pages, 11 figures. New version accepted by A&A for publicatio

Which Conflict? Understanding Conflicts inside the Board of Directors

The analysis of previous studies oncerning corporate governance shows that some variables related to board behavior have not been properly taken into account. The paper analyses board of directors in its decision-making process highlighting the importance that a clear identification of conflict could have on board effectiveness. It emerges that conflict could be distinguished in many typologies affecting board dynamics and decision-making process. The aim of the paper is to identify the mainstream and the other borderline approaches in the existent literature in order to: (i) mark some confusions in the definition or use of the concept of conflict; (ii) point-out its potential in the study of board effectiveness in a behavioural per-spective; (iii) underline the need for operationalizing the concept for a better understanding of its impact on board effectiveness and for a robust future empirical research.Conflict; Board of Directors; Decision-making Process; Board Effetiveness

Clinical and Laboratory Techniques for the Custom-Fabrication of Athletic Mouthguards

The efficacy of mouthguards for preventing sportsrelated traumatic oral injuries is well documented in those sports that mandate their use. There are three general categories of athletic mouthguards that currently are available. These include stock, mouth-formed and custom fabricated mouthguards made over a dental cast. Most mouthguards in each of these categories are made from ethylene vinyl acetate (EVA) material. Fabrication and design require professional services for impression taking and laboratory processing. Custom-fabricated mouthguards are, therefore, the most retentive. This presentation is designed to describe, in detail, clinical and laboratory procedures that are used to fabricate custom athletic mouthguards and will include the vacuum-forming technique and the heatpressure-lamination technique. Information on a new vacuum- pressure-lamination technique will be described as well as an experimental technique that utilizes photopolymerized urethane diacrylate. Several research topics for future investigation will be identified