Birds do it with plumage and songs, frogs do it with mating calls, and flowers do it with pollen compatibility, but how do yeast choose appropriate mates? While speciation has been heavily studied in macro-organisms (plants and animals), very little work has been done on the study of speciation of sexually reproducing micro-organisms. My honors project will test one possible mechanism for mate selection and reproductive isolation (key steps in speciation) in the sexually reproducing yeast Saccharomyces paradoxus. It was long assumed that most micro-organisms form essentially global, mixed populations and do not undergo speciation in the classical sense. Recent studies, however, have determined that not only does S. paradoxus form distinct populations, but actually has actually evolved assortative mating – preferentially mating with members of its own population while avoiding members of other less-compatible populations. Sexual adhesion proteins are a possible mechanism for this behavior. To test this hypothesis, I will genetically engineer strains of S. paradoxus to express sexual adhesion genes from different populations, and then determine if they have a significant effect on mate choice. In investigating the mechanism underlying the mating behavior of S. paradoxus, I hope to help develop our understanding of speciation in micro-organisms.
My name is Augustin Hennings, and I am a rising senior here at the College. I am a Neuroscience and Hispanic Studies double major and I am very excited to be leading my own research project this summer in the psychology lab of Dr. Barnet. My research concerns nicotine, a widely used drug with known neurotoxic effects. My research investigates the effect of nicotine on anxiety and stress using an animal model of anxiety called Light-Enhanced Startle (LES). Rats are naturally more anxious in bright light (where they might be more visible to predators), and LES measures anxiety as enhanced startle reactivity to brief bursts of white noise in the presence versus absence of a bright light. Our research has shown that first-time acute nicotine exposure is anxiogenic in the LES paradigm, revealing that nicotine enhances vulnerability to the negative effects of environmental stress. This is an important observation because enhanced vulnerability to the effects of stress can predispose the development of addictive dependence as well as psychiatric disease. My summer project extends our earlier research and seeks to establish the LES paradigm as an experimental model of nicotine withdrawal. There is a current gap in the literature regarding LES and nicotine withdrawal, and my research will expand on the only other published paper using this paradigm. Following nicotine exposure intended to produce dependence, anxiety measured in LES will be assessed at various points during the withdrawal (post-nicotine) period. The goal is to identify how anxiety during withdrawal varies and thereby establish possible critical periods where vulnerability to relapse may be enhanced. Identifying critical periods of anxiety and vulnerability to relapse is important to developing more targeted and effective pharmacological as well as cognitive-behavioral smoking cessation treatments.
In recent years, international development has adopted several theories and methodologies that differ from one another, essentially detailing the manner in which to alleviate poverty and address social concerns in a given community. Community Based Participatory Research, a theory on this very subject, states that in order for a community to become less marginalized, it must increase its capacity. According to Goodman, capacity is composed of both participation and leadership (1998). Without these two dimensions of social structures, a community does not have the ability to determine its needs and respond appropriately.
Hey everyone! My name is Meagan Phillips, and I’m a junior majoring in Critical Animal Studies (self-designed). I’m interested in the way humans and animals interact, both at an individual level and on a broader scale. This summer, I’ll be continuing research with Professors John Swaddle and Dana Moseley, who have been collaborating on a project to test the effectiveness of a sonic net on deterring birds from a food source. The sonic net is a device that issues a beam of sound encompassing all of the frequencies that birds use to communicate. Because communication is vital for birds (alarm calls, food calls, territorial and breeding songs), the prediction is that birds will avoid the beam of sound even if it means forsaking a perfectly good food source (in this case, a bird feeder). If it works, the hope is that it can be applied on a larger scale to prevent birds from feeding in agricultural fields and to deter them from skyscrapers, wind turbines, radio towers, and other tall manmade structures during migration.