BACKGROUND Research evaluating the effect of comprehensive coach education and practice contact restriction in youth football injury rates is sparse. In 2012, USA Football released their Heads Up Football coaching education program (HUF), and Pop Warner Football (PW) instituted guidelines to restrict contact during practice. PURPOSE To compare injury rates among youth football players aged 5 ...

[1] We use four-year time series of precipitable water (PW) and zenith neutral delay (ZND) derived from a GPS network in Hawaii to show that the statistical distributions of these quantities are closely approximated by the lognormal distribution. The long term average and median values of precipitable water decline exponentially with height, or very nearly so. The arithmetic standard deviation ...

Estimation of precipitable water (PW) in the atmosphere from ground-based Global Positioning System (GPS) essentially involves modeling the zenith hydrostatic delay (ZHD) in terms of surface Pressure (Ps) and subtracting it from the corresponding values of zenith tropospheric delay (ZTD) to estimate the zenith wet (non-hydrostatic) delay (ZWD). This further involves establishing an appropriate ...

We apply some concepts and results from mathematical logic in order to obtain an apparently new counterexample in symbolic dynamics. Two sets are said to be Muchnik equivalent if any point of either set can be used as a Turing oracle to compute a point of the other set. The Muchnik degree of a set is its Muchnik equivalence class. There is an extensive recursion-theoretic literature on the latt...

Very little is known about how products derived from the hydrothermal carbonization (HTC) of municipal waste affect availability and uptake nitrogen in plant nutrition. This study examined effects 60% sewage sludge 40% food HTC products, i.e., biochar (BC) process water (PW), as sources on garden cress growth quality. A fertilization program using four doses [(control), 9, 12, 15 kg da−1 N] BC,...

INTRODUCTION Ureteral access sheaths (UAS) facilitate flexible ureteroscopy in the treatment of urolithiasis. The physical properties of UAS vary by manufacturer and model. We compared three new UAS: Glideway (GW, Terumo, 11/13Fr, 12/14Fr), Pathway (PW, Terumo 12/14F) and Navigator HD (NHD, Boston Scientific, 11/13Fr, 12/14Fr) in the domains of safety characteristics, positioning characteristic...

The ventricles of the brain remain perhaps the largest anatomic structure in the human body without established primary purpose, even though their existence has been known at least since described by Aristotle. We hypothesize that the ventricles help match a stroke volume of arterial blood that arrives into the rigid cranium with an equivalent volume of ejected venous blood by spatially configu...

Background Contrast-enhanced H2O T1-weighted cardiovascular MRI is usually interpreted using tracer paradigms; e.g., the extra-/intravascular contrast agent (CA) partition coefficient. However, the signal molecule is water, not CA. Consequently, the myocardial extracellular volume fraction (ECV) is underestimated in proportion to its magnitude. Even more importantly, intercompartmental water ex...