Tannins are a diverse group of plant-produced, polyphenolic compounds with metal-chelating and antimicrobial properties that are prevalent in many soils. Using transcriptomics, we determined that tannic acid, a form of hydrolysable tannin, broadly affects the expression of genes involved in iron and zinc homeostases, sulfur metabolism, biofilm formation, motility, and...
Zinc is an important nutrient but can be lacking in some soil environments, influencing the physiology of soil-dwelling bacteria. Hence, we studied the global effect of zinc limitation on the transcriptome of the rhizosphere biocontrol strain Pseudomonas protegens Pf-5 (formerly Pseudomonas fluorescens). We observed that the expression of the putative...
One of the most important micronutrients for bacterial growth is iron, whose bioavailability in soil is limited. Consequently, rhizospheric bacteria such as Pseudomonas fluorescens employ a range of mechanisms to acquire or compete for iron. We investigated the transcriptomic and proteomic effects of iron limitation on P. fluorescens Pf-5 by...
The Tam McArthur Rim is a volcanic center located within the Tumalo Volcanic Field (TVF), approximately 25 km west of Bend, OR. The rim comprises of shallowly dipping bedded sequences of intermediate and silicic flows with minor tephra interbedding capped by a rhyodacite dome. Glacial activity has exposed significant portions...
Semi-volatile trace metals (e.g., Cd, Sn, Pb, Zn, Cu, Mo) have been analyzed by using laser ablation ICP-MS in a number of silicate glasses (GSE-1G, GSD-1G, NIST 610, NIST 612, BCR-2G, BHVO-2G). Our work investigates and highlights sources of uncertainty in the analysis of semi-volatile metals using LA-ICP-MS. We identify...
Substrate switching noise is becoming a concern as integrated circuits get larger and speeds get faster. Mixed-mode integrated circuits are especially affected as the substrate noise interferes with sensitive analog circuits resulting in limited signal to noise ratios. This thesis serves to study the cause of the noise at the...
Zebrafish (Danio rerio) are one of the most commonly used animal models in biomedical research. Zebrafish resource facilities, like the Zebrafish International Resource Center (ZIRC) in Eugene, Oregon, are the main providers and keepers of numerous zebrafish wild-type, mutant, and transgenic lines. Although ZIRC maintains live zebrafish at various life...
The microsporidian parasite, Pseudoloma neurophilia, is the most commonly diagnosed infectious disease in laboratory populations of the zebrafish, Danio rerio. Infections by P. neurophilia are generally subclinical, however, they can become acute either incidentally or due to experimental immune suppression. Non-protocol induced variation can confound results in laboratory experiments using...