Although exposure to bacteria has been assessed in cabin air previously, minimal numbers of samples have been collected in-flight. The purpose of this research was to comprehensively characterize bacterial concentrations in the aircraft cabin. Twelve randomly selected flights were sampled on Boeing-767 aircraft, each with a flight duration between 4.5 and 6.5 h. N-6 impactors were used to colle...

In the U.S., there is no recent database of district-level test scores that is comparable across states. We construct and evaluate such a database for years 2009-2013 to support large-scale educational research. First, we derive transformations that link each state test score scale to the scale of the National Assessment of Educational Progress (NAEP). Next, we apply these transformations to a ...

This study examined the normal ranges and the determinants for various parameters of the short-term heart rate variability (HRV) measurements in a large Korean sample of healthy people. HRV measurements were obtained in 2,748 healthy men and 735 healthy women 18-65 yr of age. The mean total power (TP), low frequency (LF), high frequency (HF), and LF/HF ratio were 1,358.9 ± 1,840.8 ms(2), 417.3 ...

The component parts of an image analysis based system for estimating the mass of swimming fish have been developed and tested under a limited range of conditions. They comprise automatic techniques for identifying video frames, which contain good images of fish, for identifying the outline of the fish in 3D space, and for determining mass from linear measurements taken from this outline. The ma...

BACKGROUND Within the construction industry the risk of lung disorders depends on the specific professions probably due to variations in the levels of dust exposure, and with dust levels depending on the work task and job function. We do not know the extent of exposure in the different professions or the variation between the different work tasks. The purpose of this study was therefore to asse...

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...

In classification problems when multiples algorithms are applied to different benchmarks a difficult issue arises, i.e., how can we rank the algorithms? In machine learning it is common run the algorithms several times and then a statistic is calculated in terms of means and standard deviations. In order to compare the performance of the algorithms, it is very common to employ statistical tests...

Hyperelastic constitutive models are frequently used to characterize the stress-strain response of highly flexible materials. Literature surveys reveal most researchers report statistical quantities (e.g. mean and standard deviation) to describe and summarize hyperelastic coefficient values. However, statistical quantities are not appropriate for describing and summarizing coefficient values of...

Intersubject variability of striate and extrastriate areas was mapped by conjoined use of positron emission tomography (PET) and magnetic resonance imaging (MRI). We used two dynamic bowtie-shaped random-dot patterns centered symmetrically around the vertical- and horizontal-meridian, respectively, presented during sequential PET scans in 11 subjects. Control condition was simple fixation on a ...