Hypotheses concerning community-level vulnerability to invasion often emphasize biotic interactions but fail to consider fine-scale variation in the physical environment. In this study, the interplay between interspecific competition and abiotic factors is examined with respect to whether scrub habitats in southern California become invaded by the Argentine ant (Linepithema humile). Argentine a...

We show how liquid migrates in sheared unsaturated granular media using a grain scale model for capillary bridges. Liquid is redistributed to neighboring contacts after rupture of individual capillary bridges leading to redistribution of liquid on large scales. The liquid profile evolution coincides with a recently developed continuum description for liquid migration in shear bands. The velocit...

Experimental evidence shows that the presence of an ambient liquid can greatly modify the collision process between two solid surfaces. Interactions between the solid surfaces and the surrounding liquid result in energy dissipation at the particle level, which leads to solid-liquid mixture rheology deviating from dry granular flow behaviour. The present work investigates how the surrounding liq...

The effects of high-temperature sterilization methods (boiling, dry-heating, autoclaving and chemiclaving) on the properties of four types of stone cast were determined. SEM observations were made of the cast surface before and after sterilization. High-temperature sterilization affected the properties of the stone casts. Boiling, dry-heating and autoclaving were considered to be unacceptable m...

ture of our Indian diseases ; but there is evidence to show from record that it was not absolutely unknown to the practitioners of the Hindu system of medicine. The ancients gave the name Diabetes or Bohumootra (Polyuria) to a group of symptoms, the most prominent being augmented secretion of urine, thirst, dry skin, gradual emaciation and loss of strength. For want of a sufficient knowledge of...

We simulate penetration of large projectiles into dry granular media using two-dimensional soft particle molecular dynamics. We systematically vary the physical parameters of the projectile (density, size, impact energy). Our results confirm the recently observed scaling of the crater depth with impact energy as observed by Uehara et al. (2003) and the effect of constant deceleration of the bal...

Using all-atom molecular dynamics (MD) simulations at constant water chemical potential in combination with basic theoretical arguments, we study hydration-induced interactions between two overall charge-neutral yet polar planar surfaces with different wetting properties. Whether the water film between the two surfaces becomes unstable below a threshold separation and cavitation gives rise to l...

We evaluated a simple, specific method for measuring plasma creatinineconcentration,invoMng enzymatic degradation of creatinine before analysis by a kineticJaff#{233} reaction. The enzymes-prepared in a dry, stable form-are convenient to use and eliminate the need to correct for sample dilution. As little as 50 1L of plasma is required, making the procedure ideal for use with samples from child...

Water and nitrogen contents were also determined. Measure ments were made on whole tissue, as well as on parenchyma. The hepatoma contained 79% water versus 71% in normal liver; the proportion of nitrogen in the solid matter of the tumor was higher than normal, indicating a decrease in non-nitrogenous compo nents, presumably glycogen and lipids. On either wet or dry weight basis, the hepatoma c...

For over 15 years now, the efficiency and reliability of centrifugal compressors have been enhanced by the application of thermoplastic materials to the eye, shaft, and balance piston labyrinth seals. Traditionally these seals have been manufactured from metallic materials and have required relatively large clearances for reliability reasons. By upgrading to carefully selected engineered thermo...