Cone-beam (CB) acquisition is increasingly used for truly three-dimensional X-ray computerized tomography (CT). However, tomographic reconstruction from data collected along a circular trajectory with the popular Feldkamp algorithm is known to produce the so-called CB artifacts. These artifacts result from the incompleteness of the source trajectory and the resulting missing data in the Radon s...

Over the last ten years a community on context has emerged. Brézillon (1999) proposed a survey of the literature about context in artificial intelligence. There is a now series of conference on context, a web site and a mailing list. The number of web pages with the word “context” has been multiply by ten in the last five years. Being among the instigators of the use of context in real-world ap...

Attention is critical for successful performance in demanding real-world situations. Yet, protracted periods of high demand may compromise attention and increase offtask thinking. Herein, we investigate if mindfulness training (MT) may promote cognitive resilience by curbing attentional lapses in high-stress cohorts. Two military cohorts were recruited during their high-stress predeployment int...

Increased variability in reaction time (RT) has been proposed as a cardinal feature of attention deficit hyperactivity disorder (ADHD). Increased variability during sustained attention tasks may reflect inefficient fronto-striatal and fronto-parietal circuitry; activity within these circuits is modulated by the catecholamines. A disruption to dopamine signaling is suggested in ADHD that may be ...

The prime motivation of this work is to devise techniques that make the Algebraic Reconstruction Technique (ART) and related methods more efficient for routine clinical use, while not compromising their accuracy. Since most of the computational effort of ART is spent for projection/backprojection operations, we first seek to optimize the projection algorithm. Existing projection algorithms are ...

There is an error in Fig 6. Please view the correct Fig 6 here. There is an error in the second paragraph of the Results section under the subheading Validation 2: Estimating Brain-Behaviour Correlations. The correct paragraph should read: Fig 6a plots the median (ρbehav, gSNRbehav,) values for PLS analysis of every task, and both GNB and CVA analysis models. In general, IND optimization improv...

Over ten years a community on context has emerged. There is a now series of conference on context, a web site and a mailing list. The number of web pages with the word “context” has been multiplied by four in the last five years. Being among the instigators of the use of context in artificial intelligence and in decision support system, we present in this paper the evolution of our thoughts ove...

Mindfulness training (MT) is a form of mental training in which individuals engage in exercises to cultivate an attentive, present centered, and non-reactive mental mode. The present study examines the putative benefits of MT in University students for whom mind wandering can interfere with learning and academic success. We tested the hypothesis that short-form MT (7 h over 7 weeks) contextuali...

Mindwandering (MW) is associated with both positive and negative outcomes. Among the latter, negative mood and negative cognitions have been reported. However, the underlying mechanisms linking mindwandering to negative mood and cognition are still unclear. We hypothesized that MW could either directly enhance negative thinking or indirectly heighten the accessibility of negative thoughts. In a...

OBJECTIVES The present study examined the effect of chewing gum on sustained attention and associated changes in subjective alertness. METHODS In a within-participants design, 20 participants completed an extended version of the sustained attention response task (SART: Robertson et al., 1997), both with and without chewing gum. Self-rated measures of alertness, contentedness, and calmness wer...