Newly discovered mutations in the GALNT3 gene causing autosomal recessive hyperostosis-hyperphosphatemia syndrome

Background and purpose Periosteal new bone formation and cortical hyperostosis often suggest an initial diagnosis of bone malignancy or osteomyelitis. In the present study, we investigated the cause of persistent bone hyperostosis in the offspring of two consanguineous parents

Analytical Solutions for Reactive Solute Transport Under an Infiltration-Redistribution Cycle

Transport of reactive solute in unsaturated soils under an infiltration-redistribution cycle is investigated. The study is based on the model of vertical flow and transport in the unsaturated zone proposed by Indelman et al. (1998), and generalizes it by accounting for linear nonequilibrium kinetics. An exact analytical solution is derived for an irreversible desorption reaction. The transport of solute obeying linear kinetics is modeled by assuming equilibrium during the redistribution stage. The model which accounts for nonequilibrium during the infiltration and assumes equilibrium at the redistribution stage is termed PEIRM (partial equilibrium infiltration-redistribution model). It allows to derive approximate closed form solutions for transport in one-dimensional homogeneous soils. These solutions are further applied to computing the field-scale concentration by adopting the Dagan and Bresler (1979) column model. The effect of soil heterogeneity on the solute spread is investigated by modeling the hydraulic saturated conductivity as a random function of horizontal coordinates. The quality of the PEIRM is illustrated by calculating the critical values of the Damköhler number which provide the achievable accuracy in estimating the solute mass in the mobile phase. The distinguishing feature of transport during the infiltration-redistribution cycle as compared to that of infiltration only is the finite depth of solute penetration. For irreversible desorption the maximum solute penetration W/θr is determined by the amount of applied water W and the residual water content θr. For sorption-desorption kinetics the maximum depth of penetration also depends on the ratio between the rate of application and the column saturated conductivity. It is shown that zr is bounded between the depths W/(θr+Kd) and W/θr corresponding to the maximum solute penetration for equilibrium transport and for irreversible desorption, respectively. This feature of solute penetration explains the unusual phenomena of plume contraction after an initial period of spreading (Lessoff et al., 2002). Unlike transport under equilibrium conditions, when the solute is completely concentrated at the front, the solute under nonequilibrium conditions is spread out behind the front. Heterogeneity leads to additional spreading of the plume

Steady flow toward wells in heterogeneous formations: Mean head and equivalent conductivity RID A-2321-2010

We consider steady flow of water in a confined aquifer toward a fully penetrating well of radius r(w) (Figure 1). The hydraulic conductivity K is modeled as a three-dimensional stationary random space function. The two-point covariance of Y = In (K/K-G) is of axisymmetric anisotropy, with I and I-v, the horizontal and vertical integral scales, respectively, and K-G, the geometric mean of K. Unlike previous studies which assumed constant flux, the well boundary condition is of given constant head (Figure 1). The aim of the study is to derive the mean head [H] and the mean specific discharge [q] as functions of the radial coordinate v and of the parameters sigma(Y)(2), e = I-v/I and r(w)/l. An approximate solution is obtained at first-order in sigma(Y)(2), by replacing the well by a line source of strength proportional to K and by assuming ergodicity, i.e., equivalence between (H) over bar, (q) over bar, space averages over the vertical, and [H], [q], ensemble means. An equivalent conductivity K-eq is defined as the fictitious one of a homogeneous aquifer which conveys the same discharge Q as the actual one, for the given head H-w in the well and a given head H in a piezometer at distance r from the well. This definition corresponds to the transmissivity determined in a pumping test by an observer that measures H-w, (H) over bar, and Q. The main result of the study is the relationship (19) K-eq = K-A(1 - lambda) + K(efu)lambda, where K-A is the conductivity arithmetic mean and K-efu is the effective conductivity for mean uniform flow in the horizontal direction in the same aquifer. The weight coefficient lambda 10, lambda has the simple approximate expression lambda* = in (r/I) ln (r/r(w)). Near the well, lambda congruent to 0 and K-eq congruent to K-A, which is easily understood, since for r(w)/I K-efu, our result indicates that the transmissivity is overestimated in a pumping test in a steady state and it decreases with the distance from the well. However, the difference between K-A and K-efu is small for highly anisotropic formations for which e << 1. A nonlocal effective conductivity, which depends only on the heterogeneous structure, is derived in Appendix A along the lines of Indelman and Abramovich [1994]

Influence of root resistivity on plant water uptake mechanism, part I: numerical solution, Transport

Abstract A one-dimensional approximate analytical model, which preserves the main features of soil-crop-atmospheric hydrodynamics, has been suggested for plant roots of low soil-root conductivity ratio (SRCR). The proposed approach involves physically based concepts, such as mass balance equation, Darcy&apos;s law, and related water uptake and plant transpiration functions. Two main assumptions have been made to derive the analytical solution: (1) gravitational flow is adopted and (2) the uniform soil moisture distribution within the root water activity zone is supposed. The mass balance equation in its integral form is solved by the method of characteristics. This leads to the two functional equations for soil pressure head and root potential, which can be solved simultaneously by using common software. The model has been further verified against the numerical one. The model represents a reasonable compromise between the complicated mechanism of unsaturated water flow with root water uptake (RWU) and still insufficient knowledge of the soil-plant-atmospheric continuum. It is able to account for temporal fluctuations in root activity zone and provides a relatively simple algorithm for investigation of RWU-mechanism. Besides the theoretical and applicative importance, this flow model yields water and velocity distributions within soil profile, and, thereby, constitutes a preliminary step toward solution of contaminant transport problems in vadose zone