As part of an evolution-function analysis, two nucleobase cation symporter 1 (NCS1) from the moss Physcomitrella patens (PpNCS1A and PpNCS1B) are examined--the first such analysis of nucleobase transporters from early land plants. The solute specificity profiles for the moss NCS1 were determined through heterologous expression, growth and radiolabeled uptake experiments in NCS1-deficient Saccha...

Long-distance phloem transport occurs under a pressure gradient generated by the osmotic exchange of water associated with solute exchange in source and sink regions. But these exchanges also occur along the pathway, and yet their physiological role has almost been ignored in mathematical models of phloem transport. Here we present a steady state model for transport phloem which allows solute l...

A three-dimensional model of interstitial fluid flow and passive species transport within mineralized regions surrounding cross-cortical vessel canals is developed. In contrast to earlier studies, the present model applies to circulatory, non-stress-induced interstitial flow in porous cortical bone. Based on previous experimental observations, the canals are modeled as line sources that pass at...

Two dimensionless parameters, the diffusional Deborah number, De, and the swelling interface number, Sw, were used as indicators of solvent and solute transport behavior in swellable hydrogel systems. Polymer relaxation and concentration-dependent diffusion led to dynamically swelling polymers which displayed Fickian, Case II, or anomalous transport behavior. Experimental systems studied includ...

Thermotransport studies have been made for liquid silver which contained trace amounts of gold, antimony and sulfur. Capillaries containing silver and homogeneously distributed solute were sub­ jected to a temperature gradient and solute redistribution at the stationary state was determined by sectioning and radiotracer technique. The net heat of transport was obtained from the slope of a plot ...

CHAPTER L GENERAL INTRODUCTION 1 [ntroduction I Dissertation Organization 4 References 5 CHAPTER 2. EVALUATION OF A SIMPLE METHOD FOR ESTIMATING SOLUTE TRANSPORT PAR.\>4ETERS: LABORATORY STUDIES 9 Abstract 9 [ntroduction 10 Materials and Methods 13 Results and Discussion 16 Conclusions 22 References 23 CHAPTER 3. A TIME DOMAIN REFLECTOMETRY METHOD TO MEASURE IMMOBILE WATER CONTENT AND MASS EXCH...

A numerical model that includes the effects of mass transfer between mobile and immobile liquid phases, advection, hydrodynamic dispersion, and melt-freeze episodes was developed to simulate ionic solute transport in melting snow. Model calibration using a tracer-infused laboratory snowpack experiment yielded a dispersivity of 0.05 cm and a mobile-immobile phase mass-transfer coefficient of 4 3...

This paper proposes groundwater flow simulation models based on explicit finite difference method (FDFLOW) and Galerkin finite element method (FEFLOW) and solute transport simulation models based on Galerkin finite element method (FESOLUTE), random walk method (RWSOLUTE) and modified method of characteristic (MMOCSOLUTE). These coupled flow and transport models are aimed at simulation of solute...

ABSTRACT Modeling of fluid flow and solute transport through fractured rock is an important component of engineering analysis in many disciplines including groundwater contamination, nuclear waste disposal, petroleum and gas production, mine excavation and geothermal production. Several studies have been conducted on single rock fracture using parallel plate model. An attempt has been made to s...

All cells face constant challenges to their volume either through changes in intracellular solute content or extracellular osmolality. Cells respond to volume perturbations by activating membrane transport and/or metabolic processes that result in net solute loss or gain and return of cell volume to its normal resting state. This paper provides a brief overview of fundamental concepts of osmoti...