Search results for "Statistical"
showing 10 items of 4960 documents
Unbiased estimates of long-term net survival of solid cancers in France
2013
In cancer studies, net survival (observed if cancer was the only cause of death) is a useful indicator but survival estimation at 5 years is insufficient for planning healthcare needs. We estimated the net survivals at 5 and 10 years in a cohort of 387,961 patients who had solid tumors between 1989 and 2004 and were followed-up until January 1, 2008. The cases were actively followed-up. Net survival was estimated with the unbiased Pohar-Perme method. The standardized net survival used the international cancer survival standard weights. In men, the standardized net survivals ranged from 92% at 5 years and 89% at 10 years (testis) to 6% at 5 years and 5% at 10 years (pancreas). In women, it r…
Serial echocardiographic left ventricular ejection fraction measurements: A tool for detecting thalassemia major patients at risk of cardiac death
2013
Cardiac damage remains a major cause of mortality among patients with thalassemia major. The detection of a lower cardiac magnetic resonance T2* (CMR-T2*) signal has been suggested as a powerful predictor of the subsequent development of heart failure. However, the lack of worldwide availability of CMR-T2* facilities prevents its widespread use for follow-up evaluations of cardiac function in thalassemia major patients, warranting the need to assess the utility of other possible procedures. In this setting, the determination of left ventricular ejection fraction (LVEF) offers an accurate and reproducible method for heart function evaluation. These findings suggest a reduction in LVEF≥7%, ov…
Repetitive TMS of cerebellum interferes with millisecond time processing
2007
Time processing is important in several cognitive and motor functions, but it is still unclear how the human brain perceives time intervals of different durations. Processing of time in millisecond and second intervals may depend on different neural networks and there is now considerable evidence to suggest that these intervals are possibly measured by independent brain mechanisms. Using repetitive transcranial magnetic stimulation (rTMS), we determined that the cerebellum is essential in explicit temporal processing of millisecond time intervals. In the first experiment, subjects' performance in a time reproduction task of short (400-600 ms) and long (1,600-2,400 ms) intervals, were evalua…
Anterior limbic alpha-like activity: a low resolution electromagnetic tomography study with lorazepam challenge
2005
Summary Objective To verify findings of an independently regulated anterior limbic alpha band source. Methods In a randomised cross-over study, the spontaneous EEG was recorded in nine healthy subjects after i.v. lorazepam or placebo. Intracerebral current densities within classical frequency bands were estimated with low resolution electromagnetic tomography [LORETA] and compared between groups with t -statistical parametric mapping [SPM{ t }]. A region-of-interest [ROI] based method was used to compare frontal and occipital alpha band activity changes. Results Irrespective of treatment group, local maxima of alpha band power were localised both in the occipital lobe, Brodman area [BA] 18,…
Cognitive control after distraction: event-related brain potentials (ERPs) dissociate between different processes of attentional allocation.
2008
Attentional reallocation after a distracting event is an important function of cognitive control. This process is tapped by the reorienting negativity (RON) event-related brain potential. It was argued that the RON reflects orientation of attention to relevant information in working memory. To test this hypothesis participants performed an auditory duration discrimination task. The stimuli were presented in a frequent standard or a rare deviant pitch with deviants resulting in behavioral distraction. Participants accomplished this task under two conditions: In the refocus condition participants were asked to respond to every stimulus; in the reorient condition participants were instructed t…
Numbers and time doubly dissociate
2011
The magnitude dimensions of number, time and space have been suggested to share some common magnitude processing, which may imply symmetric interaction among dimensions. Here we challenge these suggestions by presenting a double dissociation between two neuropsychological patients with left (JT) and right (CB) parietal lesions and selective impairment of number and time processing respectively. Both patients showed an influence of task-irrelevant number stimuli on time but not space processing. In JT otherwise preserved time processing was severely impaired in the mere presence of task-irrelevant numbers, which themselves could not be processed accurately. In CB, impaired temporal estimatio…
Task relevance and recognition of concealed information have different influences on electrodermal activity and event-related brain potentials.
2009
This study aimed at differentiating between memory- and task-related processes and their correlates on the electrodermal and electrocortical level during information concealment. Variations of the Guilty Knowledge Test were implemented in two experiments while we measured skin conductance responses (SCRs) and event-related brain potentials. P300 amplitudes were specifically enhanced for items requiring a deviant behavioral response but they were not sensitive to concealed knowledge. In contrast, N200 amplitudes differed between memorized and irrelevant items in both experiments. SCR measures reflected a combined influence of task relevance and probe recognition, and they provided incrementa…
Analgesics use in competitive triathletes: its relationship to doping and on predicting its usage
2016
The two major objectives of this study were (i) to assess variables that predict the use of analgesics in competitive athletes and (ii) to test whether the use of analgesics is associated with the use of doping. A questionnaire primarily addressing the use of analgesics and doping was distributed among 2,997 triathletes. Binary logistic regression analysis was performed to predict the use of analgesics. Moreover, the randomised response technique (RRT) was used to estimate the prevalence of doping in order to assess whether users of analgesics have a higher potential risk for doping than non-users. Statistical power analyses were performed to determine sample size. The bootstrap method was …
Confirmatory Factor Analysis of the Valencia Scale of Attitudes and Beliefs Toward Hypnosis–client Version in a Portuguese Sample
2018
Research literature about hypnosis highlights the importance of clients' attitudes and beliefs toward hypnosis because they promote hypnotic responses and may predict the effectiveness of hypnotic interventions as well as minimize iatrogenic effects for clients. This study analyzes the factorial structure and psychometric properties with confirmatory methodology of the Valencia Scale of Attitudes and Beliefs Toward Hypnosis-Client Version, using a Portuguese sample. We expected to replicate the results obtained in previous research conducted with samples from various countries. The Portuguese sample comprised 1,977 participants. We found a structure of 8 factors, with an adequate internal c…
Interrelationships between dental occlusion and plantar arch
2011
The aim of this study was to evaluate the influence of different jaw relationships on the plantar arch during gait.168 subjects, participating in this study, were distributed into two groups: a control (32 males and 52 females, ranging from 18 to 36 years of age) and a Temporomandibular joint disorders group (28 males and 56 females, ranging from 19 to 42 years of age). Five baropodometric variables were evaluated using a baropodometric platform: the mean load pressure on the plantar surface, the total surface of feet, forefoot vs rearfoot loading, forefoot vs rearfoot surface, and the percentage of body weight on each limb. The tests were performed in three dental occlusion conditions: man…