Biologically based modeling has been a critical step in human risk assessment of pharmacologic and environmental chemical exposures. Physiologically Based Pharmacokinetic (PBPK) models are used for predictions of an internal or target dose from external exposures. However, each risk assessment is dependent on the nature of the animal and human databases to support extrapolations across species, experimental paradigms, and variability of response within human populations. With an increased emphasis on the development of computational toxicology models using paradigms farther removed from physiological exposures, whole organism responses, and long-term health outcomes, a challenge arises for the integration of the state-of- the-art science PBPK modeling with emerging and current risk assessment paradigms. We will take a particular interest in original manuscripts that highlight application of cutting-edge PBPK models and analyses that can provide the basis for future modeling efforts and provide bridges to emerging toxicology paradigms. Potential topics include, but are not limited to:

• Increased understanding of human variability of pharmacokinetics and pharmacodynamics in the population
• Exploration of rodent mode of action hypotheses
• Application of biological modeling in the risk assessment of individual and mixtures of chemicals
• Identifying and addressing uncertainties in the modeling process

Before submission authors should carefully read over the journal's Author Guidelines, which are located at http://www.hindawi.com/journals/jt/guidelines/. Prospective authors should submit an electronic copy of their complete manuscript through the journal Manuscript Tracking System at http://mts.hindawi.com/ according to the following timetable: