Northern Arizona University View Institution's Website 5 articles published in JoVE Bioengineering "Avatar", a Modified Ex vivo Work Loop Experiments Using In vivo Strain and Activation Caitlin Bemis1, Kiisa Nishikawa1 1Northern Arizona University This article details the methodology for emulating in vivo muscle force production during ex vivo work loop experiments using an "avatar" muscle from a laboratory rodent to assess the contributions of strain transients and activation to the muscle force response. Environment In Vitro Scratch Assay to Demonstrate Effects of Arsenic on Skin Cell Migration Bronson I. Pinto1,4, Nathan D. Cruz1, Oscar R. Lujan1, Catherine R. Propper1,3, Robert S. Kellar1,2,4 1Department of Biological Sciences, Northern Arizona University, 2Department of Mechanical Engineering, Northern Arizona University, 3Department of Chemistry and Biochemistry, Northern Arizona University, 4Center for Bioengineering Innovation, Northern Arizona University This study focuses on an in vitro model of wound healing (scratch assay) as a mechanism for determining how environmental contaminants such as arsenic influence cellular migration. The results demonstrate that this in vitro assay provides rapid and early indications of changes to cellular migration prior to in vivo experimentation. Biology A Hybrid DNA Extraction Method for the Qualitative and Quantitative Assessment of Bacterial Communities from Poultry Production Samples Michael J. Rothrock Jr.1, Kelli L. Hiett2, John Gamble3, Andrew C. Caudill4, Kellie M. Cicconi-Hogan1, J. Gregory Caporaso5 1Egg Safety and Quality Research Unit, USDA-Agricultural Research Service, 2Poultry Microbiological Safety and Processing Research Unit, USDA-Agricultural Research Service, 3Department of Biochemistry and Biophysics, Oregon State University, 4College of Public Health, University of Georgia, 5Department of Biological Sciences, Center for Microbial Genetics and Genomics, Northern Arizona University A novel semi-automated hybrid DNA extraction method for use with environmental poultry production samples was developed and demonstrated improvements over a common mechanical and enzymatic extraction method in terms of the quantitative and qualitative estimates of the total bacterial communities. Environment Technique for Studying Arthropod and Microbial Communities within Tree Tissues Nicholas C Aflitto1, Richard W Hofstetter1, Reagan McGuire1, David D Dunn2, Kristen A Potter1 1School of Forestry, Northern Arizona University, 2Acoustic Ecology Institute We provide a technique to preserve intact tree phloem and prepare it for observation. We create an apparatus called a phloem sandwich that allows for the introduction and observation of arthropods, microbes, and other organisms that inhabit phloem tissues. Medicine The Trier Social Stress Test Protocol for Inducing Psychological Stress Melissa A. Birkett1 1Department of Psychology, Northern Arizona University This article describes a protocol for inducing psychological stress in participants, which enables researchers to measure psychological, physiological and neuroendocrine responses to stress within single participants or between groups.