In this study of Oklahoma's universal pre-K program, the authors relied on a strict birthday eligibility criterion to compare "young" kindergarten children who just completed pre-K to "old" pre-K children just beginning pre-K. This regression-discontinuity design reduces the threat of selection bias. Their sample consisted of 1,567 pre-K children and 1,461 kindergarten children who had just com...

Simultaneous multislice acquisition using rosette trajectories (SMART) is a recently introduced functional magnetic resonance imaging pulse sequence that offers high-speed data acquisition by simultaneously exciting several slices. A drawback to its benefit of rapid acquisition is the cumulative effect of the systematic noise present in the off-resonant slices. In this work, a systematic noise ...

A new method for automatic analysis and characterization of recorded hummingbird wing motion is proposed. The method starts by computing a multiscale dense optical flow field, which is used to segment the wings, i.e., pixels with larger velocities. Then, the kinematic and deformation of the wings were characterized as a temporal set of global and local measures: a global angular acceleration as...

This study investigated a hypothesis of dependence of child height and weight on the month of their birth. The sample comprised 1,241 subjects, 568 boys and 673 girls, age 6-20 years, from villages in Olsztyn Province, Northeast Poland. Individuals' height and weight data were standardized by sex and age to allow grouping of individuals born in the same month irrespective of their sex and age a...

Agilent Technologies tested a large number of 6890 Plus gas chromatographs (GCs) over a 10-month period to characterize analytical performance. A sequence of ten runs was performed on each GC to measure retention time reproducibility. The results for retention time reproducibility show that a given peak typically falls within a very tight range of 0.002 to 0.003 min. The average standard deviat...

Instantaneous texture discrimination performance was examined for different texture stimuli to uncover the use of edge-based and region-based texture analysis mechanisms. Textures were composed of randomly placed, short, oriented line segments. Line segment orientation was chosen randomly using a Gaussian distribution (described by a mean and a standard deviation). One such distribution determi...

Using computer simulation, the authors assessed the accuracy of J. E. Hunter, F. L. Schmidt, and H. Le's (2006) procedure for correcting for indirect range restriction, the most common type of range restriction, in comparison with the conventional practice of applying the Thorndike Case II correction for direct range restriction. Hunter et al.'s procedure produced more accurate estimates of bot...

The current study investigated the relationship between intraindividual variability and associative learning in younger and older adults. The authors hypothesized that higher levels of intraindividual variability would be associated with a reduction in the benefits of practice during learning, and that nonoptimal testing times would magnify these effects. Results indicated that older adults sho...

The aim of this study was to describe the physiques of Ironman athletes and the relationship between Ironman's performance, training and somatotype. A total of 165 male and 22 female competitors of the Ironman Switzerland volunteered in this study. Ten anthropometric dimensions were measured, and 12 training and history variables were recorded with a questionnaire. The variables were compared w...

Although it is generally accepted that the spread of a response time (RT) distribution increases with the mean, the precise nature of this relation remains relatively unexplored. The authors show that in several descriptive RT distributions, the standard deviation increases linearly with the mean. Results from a wide range of tasks from different experimental paradigms support a linear relation...