The Gram negative, opportunistically pathogenic Gammaproteobacterium Pseudomonas aeruginosa has a propensity to form biofilms. Biofilms are surface associated or aggregated bacterial communities, embedded in a self-derived, extracellular matrix (EPS). One major component of the P. aeruginosa biofilm EPS is the polysaccharide Psl. Psl plays a structural and protective role in P. aeruginosa biofilms by mediating attachment to abiotic surfaces and mammalian cells, conferring protection from components of the host immune response and a variety of antimicrobials, as well as promoting cell-cell adhesion. More recently, Psl has also been shown to function as a cell-cell signaling molecule that activates two diguanylate cyclases through an unknown mechanism, which results in an increase in intracellular levels of c-di-GMP. The secondary messenger c-di-GMP is central to the P. aeruginosa virulence regulatory network, and promotes biofilm formation, in part, by inducing the production of EPS components, including Psl. Thus, presence of environmental Psl appears to act as a feed-forward signaling molecule that enhances biofilm formation. In order to further understand this function, this investigation will employ mini-Tn5 mutagenesis to define the signal transduction pathway(s) responsible for activating the diguanylate cyclases through a novel feed-forward mechanism of Psl-dependent signaling in P. aeruginosa.

Washington State, in response to the recent return of grey wolves, implemented a management plan that includes the monetary compensation of ranchers who lose livestock to confirmed wolf predation. Our research looks into the reasons why many Washington State ranchers refuse to participate in these compensation programs, helping us better understand the social attitudes towards wolves and their management within the state. We were able to assess the views of Washington State ranchers through numerous key informant interviews and focus groups, followed by transcription and coding. We analyzed correlations between views on compensation and other attributes to increase our understanding of shortcomings of the compensation program. Our results allow us to assess the overall effectiveness of the wolf compensation program in Washington. Through the study of stakeholder views of the current compensation program, we are able to focus future efforts on a more widely socially accepted wolf management program in the state of Washington.