The tilt after-effect (TAE) and tilt illusion (TI) have revealed a great deal about the nature of orientation coding of 1-dimensional (1D) lines and gratings. Comparatively little research however has addressed the mechanisms responsible for encoding the orientation of 2-dimensional (2D) plaid stimuli. A multi-stage model of edge detection has recently been proposed [Georgeson, M. A. (1998) Ima...

BACKGROUND This study estimated when it is safe to stop follow-up visits after cessation of amblyopia treatment and to identify factors associated with deterioration of visual acuity. METHODS Study patients included 282 patients aged 7 to 13 years who were monitored for deterioration after cessation of amblyopia treatment (median follow-up: 3.9 years). RESULTS Six (2.1%) patients lost 2 or ...

Background. The aim of this study was to determine the incidence of tuberculosis and its predictors among HIV positive children. Methods. A six-year retrospective follow-up study was conducted among HIV infected children aged less than 15 years. Life table was used to estimate the cumulative probability of tuberculosis free survival. Cox proportional hazards model was used to identify predictor...

Because of the absence of a uniform protocol for the head-up tilt table test (HUT), we compared 1,661 consecutive patients with syncope referred for HUT. The influence of age and gender on the results (positive response rate and patterns) obtained with three different protocols, Westminster, isoprenaline and nitroglycerin (groups A, B and C) was analyzed. The proportion of women was larger in t...

We appreciate the interest of Dr H. J. Koch et al. in our article and the opportunity to respond. As they state, sports medicine has become more involved in syncope and in the tilt table test. The sports medicine literature recognizes the term exerciseassociated collapse (EAC) to describe athletes who are unable to stand or walk unaided as a result of lightheadedness, feeling faint, dizziness o...

The loss of consciousness has been a subject of wonder and uncertainty in humans, and for this reason it has been the object of medical investigation since the beginning of time. Even actually, it is certainly an unresolved clinical problem. Many centuries ago, complicated exorcisms and remedies were used on these unfortunate patients, who upon regaining consciousness would find themselves soak...

In this article, we develop a nonparametric method, called adjusted exponentially tilted (ET) likelihood, and apply it to the analysis of morphometric measures. The adjusted exponential tilting estimator is shown to have the same first-order asymptotic properties as that of the original ET likelihood. The adjusted ET likelihood ratio statistic is applied to test linear hypotheses of unknown par...

The role of tilt table testing as a diagnostic modality in children with unexplained syncope is unclear. We sent a questionnaire to members of the Pediatric and Congenital Electrophysiology Society to assess the current practice pattern. Of the 186 members, 97 (52%) replied. Twenty four percent of the pediatric electrophysiologists have completely stopped doing tilt table tests and of those per...