BACKGROUND Freezing of gait is a common and debilitating symptom affecting many patients with advanced Parkinson's disease. Although the pathophysiology of freezing of gait is not fully understood, a number of observations regarding the pattern of gait in patients with this symptom have been made. Increased 'Stride Time Variability' has been one of the most robust of these features. In this stu...

Various analytical and empirical methods assuming the existence of steady state and requiring homogenous properties of the product have been used with limited success in estimating freezing times in the food processing industry. Irrespective of the method adopted for estimating freezing time requirements, a critical process issue that needs to be considered is that of system control. Simulation...

The freezing front depth ( zff ) of annual freeze- thaw cycles is critical for monitoring the dynamics cryosphere under climate change because a sensitive indicator heat balance over atmosphere-cryosphere interface. Meanwhile, although it very promising acquiring global soil moisture distributi...

Nonsorted circles are relatively barren patterned-ground features common in most arctic tundra regions. We studied how vegetation changes on nonsorted circles might affect cryogenic processes, which is of relevance as arctic vegetation responds to climate change. Twenty-eight circles at a moist nonacidic tundra site in northern Alaska received one of four treatments: (a) vegetation removal; (b)...

A free energy functional for a crystal which contains both the symmetry-conserved and symmetry-broken parts of the direct pair correlation function has been used to investigate the fluid-solid transition in systems interacting via purely repulsive Weeks-Chandler-Anderson Lennard-Jones potential and the full Lennard-Jones potential. The results found for freezing parameters for the fluid-face ce...

2,4,6-Trinitrotoluene (TNT)-contaminated soil was remediated by an anaerobic/aerobic slurry process. Prior to treatment, the soil was spiked with [14C]-TNT. Leaching experiments were carried out with the decontaminated soil to determine the degree of binding of the radiolabel under a variety of conditions. To simulate natural degradation processes of soil organic matter, each of three columns w...

Rapidly fluctuating environmental conditions can significantly stress organisms, particularly when fluctuations cross thresholds of normal physiological tolerance. Redox potential fluctuations are common in humid tropical soils, and microbial community acclimation or avoidance strategies for survival will in turn shape microbial community diversity and biogeochemistry. To assess the extent to w...

The Hypothalamic-Pituitary-Adrenal (HPA)-axis plays an important role in the expression of defensive freezing. Adaptive freezing reactivity, characterized by an immediate increase in acute stress and timely termination upon threat offset or need to act, is essential for adequate stress coping. Blunted HPA-axis activity in animals is associated with blunted freezing reactivity and internalizing ...

Abstract Permafrost and seasonally frozen ground are important surface features in highlatitudes. Because of this, a soil-frost parameterization was added to the Penn State University/NCAR mesoscale meteorological model MM5 in combination with the well validated hydro-thermodynamic soil vegetation scheme HTSVS, which takes into account among other things soil freezing and thawing. Reanalysis of...