The effect of climate change on Dreissena polymorpha, a multiregional invasive species in North America

To study the effect of climate change across different latitudinal gradients on an aquatic invasive species in North America, filtration rates of Dreissena polymorpha were examined as part of a manipulative experiment. We took into consideration three regions across North America that the Intergovernmental Panel on Climate Change (IPCC) predicts to experience different increases in temperature by the year 2100. These three climates were simulated at the University of Michigan Biological Station in Pellston, MI and used as habitats for D. polymorpha. The effect of climate change was taken into consideration by measuring the chlorophyll A concentration at current average lake temperatures and temperatures adjusted for climate change predictions. We found that only the trials run at the mid-latitudinal region (Douglas Lake of Pellston, MI) showed a significant difference between D. polymorpha filtration rates at current and predicted climate change temperatures. We did not see a significant difference in filtration rates between the environments at current and predicted climate change temperatures at the higher (Flindt Lake of Ignace, ON) or lower (Lake Placid of Lake Placid, FL) latitudinal region. In addition, we examined the differences in D. polymorpha filtration rates due to increased temperature between the three latitudinal regions. Upon analysis of our data, we did not find a significant difference in this respect.http://deepblue.lib.umich.edu/bitstream/2027.42/64578/1/Jilek_Sookhai_Yee_Lande_2009.pd

The PEER Collaborative: Supporting Engineering Education Research Faculty with Near-peer Mentoring Unconference Workshops

The PEER Collaborative National Network is a national peer mentoring network for early career tenure-track or mid-career tenured faculty who conduct and are primarily evaluated based on their research related to engineering education. This paper discusses the development, logistics, and outcomes of two PEER workshops built around a community of practice framework. Data from internal and external evaluations are presented to provide insights into aspects that worked well and aspects that need further development. Additionally, by reflecting on the workshops, participants crafted vignettes describing the impact the PEER workshops had on their personal and professional lives. The paper concludes with a discussion on the future of PEER (and potential spin-off groups from the PEER cohorts), and the changes that will be made in future workshops. Recommendations are provided for other organizers interested in developing successful “near peer” groups to address specific community needs

The transition between stochastic and deterministic behavior in an excitable gene circuit

We explore the connection between a stochastic simulation model and an ordinary differential equations (ODEs) model of the dynamics of an excitable gene circuit that exhibits noise-induced oscillations. Near a bifurcation point in the ODE model, the stochastic simulation model yields behavior dramatically different from that predicted by the ODE model. We analyze how that behavior depends on the gene copy number and find very slow convergence to the large number limit near the bifurcation point. The implications for understanding the dynamics of gene circuits and other birth-death dynamical systems with small numbers of constituents are discussed.Comment: PLoS ONE: Research Article, published 11 Apr 201