7 research outputs found
Clinical validation of cutoff target ranges in newborn screening of metabolic disorders by tandem mass spectrometry: a worldwide collaborative project.
Dissociation of first- and second-order motion systems by perceptual learning
Previous studies investigating transfer of perceptual learning between luminance-defined (LD) motion and texture-contrast-defined (CD) motion tasks have found little or no transfer from LD to CD motion tasks but nearly perfect transfer from CD to LD motion tasks. Here, we introduce a paradigm that yields a clean double dissociation: LD training yields no transfer to the CD task, but more interestingly, CD training yields no transfer to the LD task. Participants were trained in two variants of a global motion task. In one (LD) variant, motion was defined by tokens that differed from the background in mean luminance. In the other (CD) variant, motion was defined by tokens that had mean luminance equal to the background but differed from the background in texture contrast. The task was to judge whether the signal tokens were moving to the right or to the left. Task difficulty was varied by manipulating the proportion of tokens that moved coherently across the four frames of the stimulus display. Performance in each of the LD and CD variants of the task was measured as training proceeded. In each task, training produced substantial improvement in performance in the trained task; however, in neither case did this improvement show any significant transfer to the nontrained task
Inducing Kondo screening of vacancy magnetic moments in graphene with gating and local curvature
Clinical validation of cutoff target ranges in newborn screening of metabolic disorders by tandem mass spectrometry: A worldwide collaborative project.
Purpose: To achieve clinical validation of cutoff values for newborn screening by tandem mass
215 spectrometry through a worldwide collaboration. Methods: Cumulative percentiles of amino
216 acids and acylcarnitines in dried blood spots of approximately 30 million normal newborns and
217 10,615 true positive cases are compared to assign clinical significance, which is achieved when
218 the median of a disease range is either >99%ile or <1%ile of the normal population. The cutoff
219 target ranges of analytes and ratios are then defined as the interval between the limits of the two
220 populations. When overlaps occur, adjustments are made to maximize sensitivity and specificity
221 taking in consideration all available factors. Results: As of December 1, 2010, 129 sites in 45
222 countries have uploaded to the project website a total of 23,970 percentile data points, 558,168
223 analyte results of 10,615 true positive cases with 64 conditions, and 5,088 cutoff values. The
224 average rate of submission of true positive cases between December 1, 2008 and December 1,
225 2010 was 4.7 cases per day (3,418 cases). This cumulative evidence generated 91 and 23 high
226 and low target cutoff ranges, respectively. The overall proportion of cutoff values within the
227 respective target range was 43% (2,176/5,088). Conclusions: An unprecedented level of
228 cooperation and collaboration has allowed the objective definition of cutoff target ranges for 114
229 markers applied to newborn screening of rare metabolic disorders. This set of data could be used
230 as baseline for monitoring of future performance