We report here the development of an inexpensive and engaging laboratory-based activity that can help students learn about the scientific method and the role of plant epicuticular waxes and surfactant function on waxy plant leaves as real life example in the agricultural industry. Three each of nontreated collard leaves (Brassica oleraceae L. Acephala group) and brushed-leaves were sprayed with water to demonstrate hydrophobicity of epicuticular waxes. Another set of three nontreated collard leaves was sprayed with Tween 20 containing water to demonstrate function of surfactant. Then, water retention rate was calculated by subtracting between before and after spray treatments. Water contact angles were measured by ImageJ software from nontreated and brushed-leaves from pictures taken by students' smartphone. This lab activity provides a foundation for instruction on the importance of the plant epicuticular waxes that is the outermost hydrophobic barrier in agrochemical applications and the function of surfactant on waxy leaf surface.

West Virginia University recently began a learning assistants (LA) program in its introductory calculus-based physics course targeted at increasing course effectiveness and recruiting future STEM teachers. The LA program was modeled after the Colorado Learning Assistant model. This paper describes the setting and initial results from the implementation including changes in learning gains (measured with the Force and Motion Conceptual Evaluation) and attitudes (measured with the Colorado Learning Attitudes about Science Survey). These data are combined with demographic data about the individual students and compared to baseline data collected prior to the implementation of the LA program.