We investigated whether two techniques, cold moist stratification or application of exogenous hormones, were effective in breaking seed dormancy in Linum rigidum (yellow stiff flax), whose conditions for germination have not previously been reported. We were also interested in whether surface sterilization affects seed germination rates. In the study focused on effects of stratification, we divided seeds into six groups, three surface sterilized and stratified for zero, one or two months, and three not surface-sterilized and stratified for the same time periods. The unstratified groups were placed in replicate petri dishes directly under fluorescent lights, while the others were stratified at 4⁰C for appropriate durations prior to placing under lights. We monitored germination for up to two months. Seed germination rate did not significantly differ with surface-sterilization. Germination occurred slowly and sporadically in all groups; however, longer stratification duration significantly decreased germination rates. In a second study, we tested the effect of two hormones, gibberellic acid and cytokinins on germination rates on seeds not subjected to cold stratification. We found that germination occurred more quickly in the presence of gibberellic acid at two concentrations (1000 mg L-1 or 100 mg L-1), but was unaffected by cytokinin (215 mg L-1). These results indicate that L. rigidum experiences physiological dormancy but cold stratification does not break dormancy.
Division of Natural Sciences and Engineering, University of South Carolina Upstate, Spartanburg, South Carolina
P194 • Hannah M. White, Amanda Gains, C. Brian Odom
An Examination of Less Toxic Substitutes for Ethidium Bromide Comparing Migration Shifts, Resolution, and Quantitation of Agarose Gel Stained DNA Fragments
Traditionally, DNA fragments in agarose gels have been resolved via staining with the intercalating dye, Ethidium Bromide. In recent years, less toxic and mutagenic alternatives to EtBR staining have become commercially available. Several of these newer alternatives were compared to EtBr to determine their suitability to substitute for this compound in both the teaching lab and in undergraduate research projects. Wingate University has completely replaced EtBr in the undergraduate teaching program. Can it also comparably replace EtBr in the undergraduate research lab as well?
Women are an underrepresented part of the faculty in science Depts at many U.S. universities. University and national-level policies have driven efforts to improve the imbalance. This poster highlights many of the efforts to improve this inequality by presenting the stages of the policy process. The goal of this poster is to show how gender diversity in science faculties can be an effective part of the policy agenda. Through an understanding of the policy process, science Depts can better implement policies to develop more women science academics for future generations.
1 Dept of Biology, Winthrop University, Rock Hill, SC; 2 Public Policy Program, UNC Charlotte, Charlotte, NC
P196 • Tracy L. Deem1, Crystal Scott Croshaw2
Harmful Effects of Insecticide on Larval Development in Callosobruchus maculatus ? An Inquiry-Based Lab for Immunology, Biochemistry, or Developmental Biology Classes
The American Association for the Advancement of Science (AAAS) has challenged biology educators to develop active learning strategies that ensure students understand the process of science. In this multi-week, inquiry-based laboratory exercise, students are asked to design experiments to examine a possible mechanism for insect resistance to insecticides. Recent research has suggested that resistance may be due in part to the activity of the enzyme phenoloxidase (PO). PO is the last enzyme in a multi-enzyme cascade leading to melanin deposition. Melanization is one of the defenses used by the innate immune system of insects to surround and neutralize pathogens. Students are tasked with designing experiments to detect PO activity and to determine if insecticide-induced changes in larval development correlate with PO activity. Since this laboratory is designed to last the entire semester, it gives students a better sense of the process of science.
1 Dept of Biology, Bridgewater College, Bridgewater, VA; 2 College of Integrated Science and Technology, James Madison University, Harrisonburg, VA
P197 • Halley Alberts, Rob Hopkins
Improving Spatial Thinking: A Student-Driven Approach to Teaching Spatial Statistics
Spatial analysis is a powerful and broadly applicable analytical tool that is especially useful to ecologists. However, the topic is too often under-addressed in the classroom setting. When it is taught the traditional approach may be less than effective at fostering an improvement in student spatial thinking. Typically, students follow a strict procedure of data collection and data analysis - effectively reducing the exercise to plug-and-chug. In the words of a former pupil this approach regularly leaves students knowing essentially nothing except for a formula that they have no idea how or why it works. In this paper we present a primer exercise aimed at improving student spatial thinking and their basic understanding of how spatial statistic equations provide information about spatial dispersion. The central component of this approach is to have students develop their own spatial statistic equation to quantify dispersion and compare the results of their equation with a standard statistic. In the end, by creating the equation themselves many students gain a firmer understanding of where the results came from, rather than simply getting a number that they can’t relate to. Not only does this method aid in teaching a particular concept, it also requires more active learning and circumvents the tendency for students to relegate labs to strict procedure-following exercises or what we like to refer to has hands-on, brains-off.
Dept of Biology, University of Rio Grande, Rio Grande, OH
P198 • Jordan L. Hartman, Amy L. Rangel, C. Brian Odom
