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Effective insect pollination requires appropriate responses to internal and external environmental cues in both the plant and the pollinator. Helianthus annuus, a highly outcrossing species, is marked for its uniform eastward orientation of mature pseudanthia, or capitula. Here we investigate how this orientation affects floral microclimate and the consequent effects on plant and pollinator interactions and reproductive fitness. We artificially manipulated sunflower capitulum orientation and temperature in both field and controlled conditions and assessed flower physiology, pollinator visits, seed traits and siring success. East-facing capitula were found to have earlier style elongation, pollen presentation and pollinator visits compared with capitula manipulated to face west. East-facing capitula also sired more offspring than west-facing capitula and under some conditions produced heavier and better-filled seeds. Local ambient temperature change on the capitulum was found to be a key factor regulating the timing of style elongation, pollen emergence and pollinator visits. These results indicate that eastward capitulum orientation helps to control daily rhythms in floral temperature, with direct consequences on the timing of style elongation and pollen emergence, pollinator visitation, and plant fitness
Development of a Spatial Visualization Assessment Tool for Younger Students Using a Lego™ Assembly TaskIn recent years, it has increasingly been recognized that spatial visualization skills are important in supporting student success in Science, Technology, Engineering, and Math (STEM) education and retention of these students in STEM careers. Many first year college engineering programs and high schools with pre-engineering curriculum have incorporated spatial visualization training into their courses. However, there is no reason why spatial visualization training could not occur at a much younger age, like elementary school. Often at the high school and college level, the Purdue Spatial Visualization Test: Rotations (PSVT:R), which is recognized as a gold standard assessment tool, is used to measure students’ spatial skills learning gains. The PSVT:R is a 20 minute timed test consisting of 30 three-dimensional rotations problems. While the PSVT:R test has been well validated, there are benefits to developing alternative methods of assessing spatial visualization skills suitable for elementary school grades. Researchers at XXX developed an assembly pre- and post- test based upon a timed Lego™ exercise. Students are timed to see how long it would take them to build small Lego shapes using only a picture of the final assembly, but no instructions. The test was implemented at the beginning and then at themore »