Paroxysmal positional vertigo is a frequent cause for consultation. When approaching these patients, we try to differentiate central from peripheral causes, but sometimes we find manifestations that generate diagnostic doubts. In this review, we address atypical paroxysmal positional vertigo, reviewing the literature on the subject and giving a provisional definition of atypical positional vertigo as well as outlining its causes and pathophysiological mechanisms.
View Article and Find Full Text PDFThis study developed and evaluated a visual approach to promoting environmental health literacy about highway pollution. The Interactive Map of Chinatown Traffic Pollution was the centerpiece of a communication approach designed to make complex scientific information about traffic-related air pollution comprehensible to Chinese immigrants with limited English proficiency. The map enabled visualization of the spatial distribution of ultrafine particles (less than 100 nanometers in diameter), a toxic and invisible form of air pollution, in Boston Chinatown.
View Article and Find Full Text PDFIncreasing evidence points to an association of airborne pollutant exposure with respiratory, cardiovascular, and neurological pathology. We examined whether or not ground-level ozone or fine particulate matter ≤ 2.5 μm in diameter (PM2.
View Article and Find Full Text PDFThere is little doubt that having a theoretic foundation will benefit the field of visualization, including its main subfields. Because there has been a substantial amount of work on taxonomies and conceptual models in the visualization literature and some recent work on theoretic frameworks, such a theoretic foundation is not a foolish or impractical ambition. This article asks, "How can we build a theoretic foundation for visualization collectively as a community?" The authors envision the pathways for four different aspects of a theoretic foundation: taxonomies and ontologies, principles and guidelines, conceptual models and theoretic frameworks, and quantitative laws and theoretic systems.
View Article and Find Full Text PDFJMIR Public Health Surveill
April 2017
Background: Digital maps are instrumental in conveying information about environmental hazards geographically. For laypersons, computer-based maps can serve as tools to promote environmental health literacy about invisible traffic-related air pollution and ultrafine particles. Concentrations of these pollutants are higher near major roadways and increasingly linked to adverse health effects.
View Article and Find Full Text PDFThis article introduces the neuroimaging community to the dynamic visualization workbench, Weave (https://www.oicweave.org/), and a set of enhancements to allow the visualization of brain maps.
View Article and Find Full Text PDFInt J Data Min Bioinform
January 2012
In this paper, we introduce a heuristic method for gene selection. We target this method, coupled with RadViz visualisation, to the visual prediction of tissue samples which may exist in normal and disease states. As a result of this coupling, the gene selection process, predictive model training and evaluation as well as the model's application for tissue sample prediction can all be intuitively visualised.
View Article and Find Full Text PDFIEEE Trans Vis Comput Graph
December 2008
Radviz is a radial visualization with dimensions assigned to points called dimensional anchors (DAs) placed on the circumference of a circle. Records are assigned locations within the circle as a function of its relative attraction to each of the DAs. The DAs can be moved either interactively or algorithmically to reveal different meaningful patterns in the dataset.
View Article and Find Full Text PDFPhys Rev E Stat Nonlin Soft Matter Phys
January 2008
We derive exact asymptotic results for a stochastic queueing model in which tasks are executed according to a continuous-valued priority. The distribution P(tau) of the waiting times tau of executed tasks for this model is shown to behave asymptotically as a power law, P(tau) approximately tau(-3/2), when the average rates of task arrival lambda and execution micro satisfy micro
IEEE Trans Vis Comput Graph
February 2008
Information Visualization (InfoVis) is now an accepted and growing field but questions remain about the best uses for and the maturity of novel visualizations. Usability studies and controlled experiments are helpful but generalization is difficult. We believe that the systematic development of benchmarks will facilitate the comparison of techniques and help identify their strengths under different conditions.
View Article and Find Full Text PDFThe self-reporting of cancer history is becoming increasingly important, as it frequently guides medical decision-making. We studied the accuracy of personal cancer history using a self-administered questionnaire, comparing the results with the Tumor Registry at our institution. Among 39,662 records, we identified 3614 women with a single cancer in the Tumor Registry who reported none or one cancer on their questionnaire.
View Article and Find Full Text PDFWe study the structure and robustness of universality classes for queueing, deriving analytic results for priority-based models with continuous-valued priorities. By mapping one model onto the problem of biased diffusion, we show that its distribution of waiting times, P(tau), decreases for large times tau as P(tau) approximately tau;{-3/2} or as P(tau) approximately tau;{-5/2}exp(-tau/tau_{0}) in different parameter regimes. In a second model, introducing a cost for switching between different classes of tasks substantially changes the asymptotic behavior of P(tau).
View Article and Find Full Text PDFA theoretical study of the physical properties which determine the variation in signal strength from probe to probe on a microarray is presented. A model which incorporates probe-target hybridization, as well as the subsequent dissociation which occurs during stringent washing of the microarray, is introduced and shown to reasonably describe publicly available spike-in experiments carried out at Affymetrix. In particular, this model suggests that probe-target dissociation during the stringent wash plays a critical role in determining the observed hybridization intensities.
View Article and Find Full Text PDFAim: The purpose of this study was to develop an accurate regression model to predict insulin resistance in girls with premature adrenarche.
Methods: The insulin sensitivity index was calculated from the frequently sampled intravenous glucose tolerance test with tolbutamide. Thirty-five prepubertal girls (23 Caribbean-Hispanic and 12 African-American; mean age 6.
In the standard Arrhenius picture [S. Arrhenius, Z. Phys.
View Article and Find Full Text PDFThe clockwise (CW) or counterclockwise (CCW) spinning of a bacterial flagellar motor is controlled by the concentration [Y] of a phosphorylated protein, CheY-P. Representing the stochastic switching behavior of the motor by a dynamical two-state (CW and CCW) model, whose energy levels fluctuate in time (t) as [Y](t) fluctuates, we show that temporal fluctuations in [Y](t) can generate a power-law distribution for the durations of the CCW states, in agreement with recent experiments. Correlations between the duration times of nearby CCW (CW) intervals are predicted by our model, and shown to exist in the experimental data and to affect the power spectrum for motor switching.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
July 2005
Synchronous firing peaks at levels greatly exceeding background activity have recently been reported in neocortical tissue. A small subset of neurons is dominant in a large fraction of the peaks. To investigate whether this striking behavior can emerge from a simple model, we constructed and studied a model neural network that uses a modified Hopfield-type dynamical rule.
View Article and Find Full Text PDFObjective: We report the presentation and 5-year follow-up of 89 African-American (AA) and Caribbean-Hispanic (CH) youths with type 2 diabetes mellitus (T2DM) followed at the Montefiore Medical Center, Bronx, N.Y., USA, from 1990 to 2000.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
June 2003
A method of analyzing DNA microarray data based on the physical modeling of hybridization is presented. We demonstrate, in experimental data, a correlation between observed hybridization intensity and calculated free energy of hybridization. Then, combining hybridization rate equations, calculated free energies of hybridization, and microarray data for known target concentrations, we construct an algorithm to compute transcript concentration levels from microarray data.
View Article and Find Full Text PDFNumerical solutions of the micromagnetic Landau-Lifshitz-Gilbert equations provide valuable information at low temperatures (T), but produce egregious errors at higher T. For example, Curie temperatures are often overestimated by an order of magnitude. We show that these errors result from the use of block or coarse-grained variables, without a concomitant renormalization of the system parameters to account for the block size.
View Article and Find Full Text PDFWe have observed low-frequency noise due to quasiequilibrium thermal magnetization fluctuations in micron-scale magnetic tunnel junctions (MTJs). This strongly field-dependent magnetic noise occurs within the magnetic hysteresis loops, either as 1/f or Lorentzian (random telegraph) noise. We attribute it to the thermally excited hopping of magnetic domain walls between pinning sites.
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