Search results for " processing"
showing 10 items of 7549 documents
Cognitive dysfunction in patients with relapsing-remitting multiple sclerosis
2006
Cognitive dysfunction is considered one of the clinical markers of multiple sclerosis (MS). However, in the literature there are inconsistent reports on the prevalence of cognitive dysfunction, and separate data for the relapsing-remitting (RR) type of the disease are not always presented. In this study, we submitted 461 RRMS patients to a battery of neuropsychological tests to investigate their impairment in various cognitive domains. As a consequence of the exclusion criteria, the sample is not fully representative of the entire population of RRMS patients. In this selected sample, when only the eight scores of a core battery (Mental Deterioration Battery) were considered (with respectiv…
P and R Wave Detection in Complete Congenital Atrioventricular Block
2009
Complete atrioventricular block (type III AVB) is characterized by an absence of P wave transmission to ventricles. This implies that QRS complexes are generated in an autonomous way and are not coordinated with P waves. This work introduces a new algorithm for the detection of P waves for this type of pathology using non-invasive electrocardiographic surface leads. The proposed algorithm is divided into three stages. In the first stage, the R waves located by a QRS detector are used to generate the RR series and time references for the other stages of the algorithm. In the second stage, the ventricular activity (QT segment) is removed by using an adaptive filter that obtains an averaged pa…
Exploring the reciprocal modulation of time and space in dancers and non-dancers.
2014
We explored whether time and space representations modulate each other in subjects that are trained to integrate time and space dimensions, i.e., professional dancers. A group of dancers, and one of non-dancers, underwent two different tasks employing identical stimuli. A first static central line could last one of three possible durations and could have one of three possible lengths. A second growing line appeared from the left or right of the screen and grew up toward the opposite direction at constant velocity. In the Spatial task, subjects encoded the length of the static line and stopped the growing line when it had reached half the length of the static one, regardless of time travel. …
Accuracy and accommodation capability of a handheld autorefractor
2000
Purpose: To determine the accuracy of measurement by the Nikon Retinomax handheld autorefractor and its ability to relax accommodation. Setting: Pediatric Section, Department of Ophthalmology, University of Mainz, Germany. Methods: To perform a series of comparative measurements, autorefractor readings were obtained on healthy young adults (students) and on children aged 2 to 12 years. The autorefractor readings were compared with subjective refractions of the young adults and with cycloplegic retinoscopy of the children. Results: In adults, the accuracy of the handheld autorefractor measurements was comparable to that of conventional tabletop autorefractors. In children, the autorefractor …
Topographic heterogeneity of amyloid B-protein epitopes in brains with various forms of neuronal ceroid lipofuscinoses suggesting defective processin…
1990
To verify our hypothesis of defective protease inhibitor domains that are encoded by abnormal processing of amyloid precursor protein (APP) in brains of patients with neuronal ceroid lipofuscinoses (NCL), immunohistochemical and cytochemical studies were performed with monoclonal antibodies (mAbs) directed against various domains of APP. For the studies, 22 autopsy brains were used: 12 with different forms of NCL, and 10 control brains. The staining procedure for the avidin-biotin complex (ABC) technique and the postembedding gold-labelled procedure for electron microscopy (EM) were employed. Of all mAbs used for the study, only mAbs generated against amyloid B-protein bound to neural tissu…
On-Capillary Surface-Enhanced Raman Spectroscopy: Determination of Glutathione in Whole Blood Microsamples.
2018
Oxidative stress monitoring in the neonatal period supports early outcome prediction and treatment. Glutathione (GSH) is the most abundant antioxidant in most cells and tissues, including whole blood, and its usefulness as a biomarker has been known for decades. To date, the available methods for GSH determination require laborious sample processing and the use of sophisticated laboratory equipment. To the best of our knowledge, no tools suitable for point-of-care (POC) sensing have been reported. Surface-enhanced Raman spectroscopy (SERS), performed in a microvolume capillary measurement cell, is proposed in this study as a robust approach for the quantification of GSH in human whole blood…
Amplitude, Latency, and Peak Velocity in Accommodation and Disaccommodation Dynamics
2017
The aim of this work was to ascertain whether there are differences in amplitude, latency, and peak velocity of accommodation and disaccommodation responses when different analysis strategies are used to compute them, such as fitting different functions to the responses or for smoothing them prior to computing the parameters. Accommodation and disaccommodation responses from four subjects to pulse changes in demand were recorded by means of aberrometry. Three different strategies were followed to analyze such responses: fitting an exponential function to the experimental data; fitting a Boltzmann sigmoid function to the data; and smoothing the data. Amplitude, latency, and peak velocity of …
Legibility of Text and Pictograms in Variable Message Signs: Can Single-Word Messages Outperform Pictograms?
2018
The current research shows the advantage of single-word messages in the particular case of variable message signs (VMSs) with a high aspect ratio.Early studies on traffic sign design proposed that pictorial information would advantage equivalent text messages in static signs.We used a driving simulator to present individually 36 VMSs, showing six words (e.g., "congestion") and six danger signs (e.g., congestion traffic sign). In Experiment 1, 18 drivers read aloud the text or orally identified the pictograms as soon as they could correctly do it. In Experiment 2, a different sample of 18 drivers gave a motor response, according to the meaning of the message. We analyzed the legibility dista…
Adaptive frequency decomposition of EEG with subsequent expert system analysis.
2001
We present a hybrid system for automatic analysis of clinical routine EEG, comprising a spectral analysis and an expert system. EEG raw data are transformed into the time-frequency domain by the so-called adaptive frequency decomposition. The resulting frequency components are converted into pseudo-linguistic facts via fuzzification. Finally, an expert system applies symbolic rules formulated by the neurologist to evaluate the extracted EEG features. The system detects artefacts, describes alpha rhythm by frequency, amplitude, and stability and after artefact rejection detects pathologic slow activity. All results are displayed as linguistic terms, numerical values and maps of temporal exte…
Thalamic infarctions cause side-specific suppression of vestibular cortex activations.
2005
H2O15-PET was performed during caloric vestibular stimulation of the right and left external ears in eight right-handed patients with acute unilateral infarctions or haemorrhages of the posterolateral thalamus (four right, four left). The posterolateral thalamus is the relay station for ipsi- and contralateral ascending vestibular input to the multiple multisensory vestibular cortex areas. The aim of this study was to evaluate the differential effects of unilateral vestibular thalamic lesions on thalamo-cortical projections, right hemispheric dominance and reciprocal inhibitory visual-vestibular interaction, as well as perceptual and ocular motor consequences during caloric irrigation. The …