Rachel T. Johnson

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The mechanism of uptake and efflux of porfiromycin (PFM) by HCT 116 human colon carcinoma cells or freshly obtained human RBC was investigated. The time course of uptake of radioactivity upon exposure of HCT 116 cells to [14C]PFM showed one fast and one slow phase of linear increase. The initial phase of PFM uptake was not saturable with external drug(More)
During acetaminophen (APAP) hepatotoxicity, increased expression of multidrug resistance-associated proteins 2, 3, and 4 (Mrp2-4) occurs. Mrp4 is the most significantly upregulated transporter in mouse liver following APAP treatment. Although the expression profiles of liver transporters following APAP hepatotoxicity are well characterized, the regulatory(More)
Cycle Time -- Throughput curves (CT-TH), which plot the average cycle time versus start rate for a given product mix, are often used to support decisions made in manufacturing settings, such as the impact of proposed changes in start rate on mean cycle time. Discrete event simulation is often used to generate estimations of cycle time at a significant(More)
Existing robotic manipulator and controller designs compare unfavorably to the human arm when performing tasks in unstructured environments. Traditionally, “anthropomorphic” designs have focused on replicating only the kinematics of the human arm. In contrast, we describe a versatile parallel computing architecture for emulating the spinal circuits of the(More)
The use of simulation as a modeling and analysis tool is wide spread. Simulation is an enabling tool for experimenting virtually on a validated computer environment. Often the underlying function for the results of a computer simulation experiment has too much curvature to be adequately modeled by a low order polynomial. In such cases finding an appropriate(More)
This paper illustrates an example of the use of a metamodeling approach to simulation through an example of two real world semiconductor manufacturing systems. The meta-model used was from Yang <i>et al.</i> (2004) and has similarities to Cheng and Kleijnen (1999). The approach aims at reducing the amount of simulation work necessary to generate high(More)
This paper describes the use of the design and analysis of experiments to calibrate an agent-based simulation model of a peace-keeping mission. The situation depicted is a refugee camp scenario in which de-escalation of enraged civilians is required by military personnel. Calibration was determined by ensuring that the military actions in the simulation(More)