Physician Awareness of Drug Cost: A Systematic Review

From a review of data from 24 studies, Michael Allan and colleagues conclude that doctors often underestimate the price of expensive drugs and overestimate the price of those that are inexpensive

Phase Behavior of Aqueous Na-K-Mg-Ca-CI-NO3 Mixtures: Isopiestic Measurements and Thermodynamic Modeling

A comprehensive model has been established for calculating thermodynamic properties of multicomponent aqueous systems containing the Na{sup +}, K{sup +}, Mg{sup 2+}, Ca{sup 2+}, Cl{sup -}, and NO{sub 3}{sup -} ions. The thermodynamic framework is based on a previously developed model for mixed-solvent electrolyte solutions. The framework has been designed to reproduce the properties of salt solutions at temperatures ranging from the freezing point to 300 C and concentrations ranging from infinite dilution to the fused salt limit. The model has been parameterized using a combination of an extensive literature database and new isopiestic measurements for thirteen salt mixtures at 140 C. The measurements have been performed using Oak Ridge National Laboratory's (ORNL) previously designed gravimetric isopiestic apparatus, which makes it possible to detect solid phase precipitation. Water activities are reported for mixtures with a fixed ratio of salts as a function of the total apparent salt mole fraction. The isopiestic measurements reported here simultaneously reflect two fundamental properties of the system, i.e., the activity of water as a function of solution concentration and the occurrence of solid-liquid transitions. The thermodynamic model accurately reproduces the new isopiestic data as well as literature data for binary, ternary and higher-order subsystems. Because of its high accuracy in calculating vapor-liquid and solid-liquid equilibria, the model is suitable for studying deliquescence behavior of multicomponent salt systems

GPS surveys within Falls Creek: Implementation and processing for aerial photography

This paper details GPS surveys undertaken in Falls Creek Ski Resort for a research project. Static, rapid-static and RTK GPS surveys were undertaken to establish a framework of accurate positional points with in the study area. Campaigns involved control surveys, coordination of photo control and elevation profiles, utilising the different GPS positioning techniques listed. The logistical problems of coordinating survey marks in areas of sparse survey control, deploying photo control targets over snow for image acquisition are discussed. The imagery acquired, in both winter (snow cover) and spring (no-snow cover), was later used to create surface models. The required positional accuracies resulting from the GPS surveys, for the photogrammetric validation purposes, were <20 mm for both Easting and Northing (MGA94, Zone 55), and <50 mm for elevation (AHD). The required post-processing and the results of rigorous network adjustment are also detailed. GPS static data was network adjusted from simultaneous state-wide GPSnet data using MGA94 coordinates derived from the ARGN. Network adjustments were required to obtain the best possible coordinates for control marks and photo control targets. Ausgeiod98 was used to model AHD elevations since no AHD benchmark was available. Network adjusted control marks agreed well with independent checks obtained from the online AUSPOS GPS data processing service. All network adjustment residuals satisfied the required accuracies