Life Sciences Commons^™

Rearrangement Of The Rna Polymerase Subunit H And The Lower Jaw In Archaeal Elongation Complexes, Sebastian Grünberg, Christoph Reich, Mirijam E. Zeller, Michael S. Bartlett, Michael Thomm

Biology Faculty Publications and Presentations

The lower jaws of archaeal RNA polymerase and eukaryotic RNA polymerase II include orthologous subunits H and Rpb5, respectively. The tertiary structure of H is very similar to the structure of the C-terminal domain of Rpb5, and both subunits are proximal to downstream DNA in pre-initiation complexes. Analyses of reconstituted euryarchaeal polymerase lacking subunit H revealed that H is important for open complex formation and initial transcription. Eukaryotic Rpb5 rescues activity of the ΔH enzyme indicating a strong conservation of function for this subunit from archaea to eukaryotes. Photochemical cross-linking in elongation complexes revealed a striking structural rearrangement of RNA …

The Complexity-Independence Of The Origin Of Life, Radu Popa

Systems Science Friday Noon Seminar Series

It is often stated that the macroevolution of life is driven toward increased Complexity, and indeed, biosystems situated at higher evolutionary level show higher levels of Complexity. Yet, evidence also shows that some dynamic systems evolve toward lower entropy states, and not by increasing Complexity, but by increasing Organization. Organization is a parameter with two almost orthogonal components: Order and Complexity. Hence, it is possible for a dynamic system to experience changes in Organization in ways that do not elicit changes in Complexity. Whether Order or Complexity controls changes in Organization is dictated by the capacity of a system to …

Biological Control Of Purple Loosestrife (Lythrum Salicaria): Factors Affecting Galerucella Pusilla And Galerucella Calmariensis Establishment In Tidal Areas, Lynda Kathryn Moore

Dissertations and Theses

Galerucella pusilla and G. calmariensis have provided successful biological control of purple loosestrife (Lythrum salicaria L.) in non-tidal areas but only marginal control in areas of tidal influence. While a previous study identified mechanical scour by tidal waters as the main cause of establishment failure, purple loosestrife stem density explained more than 80% of the variability in presence and absence of Galerucella at my study sites in the Columbia River Estuary. A logistic regression model using purple loosestrife stem density, elevation, and their interaction as predictors accurately predicted 92.5% of Galerucella presence or absence observations of a test data …

Similarity Of Nutrient Uptake And Root Dimensions Of Engelmann Spruce And Subalpine Fir At Two Contrasting Sites In Colorado, Melissa S. Lucash, Ruth D. Yanai, Karis J. Mcfarlane, Sarah E. Kulpa, Dustin M. Wood

Environmental Science and Management Faculty Publications and Presentations

Nutrient uptake capacity is an important parameter in modeling nutrient uptake by plants. Researchers commonly assume that uptake capacity measured for a species can be used across sites. We tested this assumption by measuring the nutrient uptake capacity of intact roots of Engelmann spruce (Picea engelmanni Parry) and subalpine fir (Abies lasiocarpa (Hook.) Nutt.) at Loch Vale Watershed and Fraser Experimental Forest in the Rocky Mountains of central Colorado. Roots still attached to the tree were exposed to one of three concentrations of nutrient solutions for time periods ranging from 1 to 96h, and solutions were analyzed for ammonium, …

A Phylogenetic Study Of The Old World Asclepiadinae (Apocynaceae) Based On Chloroplast And Nuclear Dna Sequence Data, David Chuba

Dissertations and Theses

Relationships within the African Asclepias generic complex (Asclepiadinae, Apocynaceae) have for a long time been only a matter of intuitive speculation and generic delimitations have been diverse and rather contentious. Generic delimitation in this group has been based on morphological characters that are usually not exclusive to any particular clade or genus. The difficulty of identifying taxonomically useful morphological characters for inferring generic delimitations has led to differences in the emphasized characters by different taxonomists. This study is aimed at understanding phylogenetic relationships of species within the African Asclepias complex based upon the nuclear PgiC and three chloroplast DNA regions, …

Lipid-Protein Interactions Probed By Electron Crystallography, Steve L. Reichow, Tamir Gonen

Chemistry Faculty Publications and Presentations

Electron crystallography is arguably the only electron cryomicroscopy (cryoEM) technique able to deliver an atomic-resolution structure of membrane proteins embedded in the lipid-bilayer. In the electron crystallographic structures of the light driven ion pump, bacteriorhodopsin, and the water channel, aquaporin-0, sufficiently high resolution was obtained and both lipid and protein were visualized, modeled and described in detail. An extensive network of lipid-protein interactions mimicking native membranes is established and maintained in two-dimensional (2D) crystalline vesicles used for structural analysis by electron crystallography. Lipids are tightly integrated into the protein's architecture where they can affect the function, structure, quaternary assembly and …

Sex-Specific Variation In The Interaction Between Distichlis Spicata (Poaceae) And Mycorrhizal Fungi, Sarah M. Eppley, Charlene Ashley Mercer, Christian Haaning, Camille Brianne Graves

Biology Faculty Publications and Presentations

Associations between mycorrhizal fungi and plants can influence intraspecific competition and shape plant population structure. While variation in plant genotypes is known to affect mycorrhizal colonization in crop systems, little is known about how genotypes affect colonization in natural plant populations or how plant sex might influence colonization with mycorrhizal fungi in plant species with dimorphic sexual systems. In this study, we analyzed mycorrhizal colonization in males and females of the wetland dioecious grass Distichlis spicata, which has spatially segregated sexes. Our results suggest that D. spicata males and females interact with mycorrhizal fungi differently. We discuss the implications for …

Apoptotic And Chemotherapeutic Properties Of Iron (Iii)-Salophene In An Ovarian Cancer Animal Model, Thilo S. Lange, Carolyn Mccourt, Rakesh K. Singh, Kyu Kwang Kim, Ajay P. Singh, Brian S. Luisi, Onur Alptürk, Robert M. Strongin, Laurent Brard

Chemistry Faculty Publications and Presentations

The cytotoxicity of organometallic compounds iron(III)-, cobalt(III)-, manganese(II)-, and copper(II)-salophene (-SP) on platinum-resistant ovarian cancer cell lines was compared. Fe-SP displayed selective cytotoxicity (IC(50) at ~1 muM) against SKOV-3 and OVCAR-3 cell lines while Co-SP caused cytotoxic effects only at higher concentrations (IC(50) at 60 muM) and Cu-SP effects were negligible. High cytotoxicity of Mn-SP (30-60 muM) appeared to be nonspecific because the Mn-chloride salt reduced cell viability similarly. The effect of Fe-SP at 1 muM proved to be ovarian cancer cell selective when compared to a panel of cell lines derived from different tumors. The first irreversible step in …

Interview With Angela Martin, Village Gardens, 2009 (Audio), Angela Martin

All Sustainability History Project Oral Histories

Interview of Angela Martin by Steve Jarosz at Village Gardens, Portland, Oregon on August 6th, 2009.

The interview index is available for download.

Fecal-Sac Ingestion By Spotted Towhees, Jenny E. Mckay, Michael T. Murphy, Sarah Bartos Smith, Jennifer K. Richardson

Biology Faculty Publications and Presentations

Altricial nestlings encase excrement in fecal sacs that parents remove by either ingesting them or transporting them away from the nest. Ingestion may allow energetically or nutritionally deprived parents to recapture energy or nutrients that might be lost because of nestlings' inefficient digestion (the "parental-nutrition hypothesis"), but ingestion may also permit parents to avoid flights from the nest that interfere with parental care (e.g., brooding young; the "economic-disposal hypothesis"). We used a hypothetico-deductive approach to test the two hypotheses' ability to account for fecal-sac ingestion by the Spotted Towhee (Pipilo maculatus). We confirmed the parental-nutrition hypothesis' predictions that …

Interview With Sarah Patterson, Lettuce Grow Garden Foundation, 2009 (Audio), Sarah Patterson

All Sustainability History Project Oral Histories

Interview of Sarah Patterson by Diane Mahon in Portland, Oregon on July 29th, 2009.

The interview index is available for download.

Interview With Rodney Bender, Growing Gardens, 2009 (Audio), Rodney Bender

All Sustainability History Project Oral Histories

Interview of Rodney Bender by Sarah Roecker at Growing Gardens Portland, Oregon on July 29th, 2009.

The interview index is available for download.

Interview With Caitlin Blethen, Growing Gardens, 2009 (Audio), Caitlin Blethen

All Sustainability History Project Oral Histories

Interview of Caitlin Blethen by Kristin Milner at Growing Gardens Organization Portland, Oregon on July 29th, 2009.

The interview index is available for download.

Interview With Marissa Madrigal, Jeff Cogen Chief Of Staff, 2009 (Audio), Marissa Madrigal

All Sustainability History Project Oral Histories

Interview of Marissa Madrigal by Andrea Schons in Portland, Oregon on July 23rd, 2009.

The interview index is available for download.

Increasing The Reliability Of Ecological Models Using Modern Software Engineering Techniques, Robert M. Scheller, Brian R. Sturtevant, Eric J. Gustafson, Brendan C. Ward, David J. Mladenoff

Environmental Science and Management Faculty Publications and Presentations

Modern software development techniques are largely unknown to ecologists. Typically, ecological models and other software tools are developed for limited research purposes, and additional capabilities are added later, usually in an ad hoc manner. Modern software engineering techniques can substantially increase scientific rigor and confidence in ecological models and tools. These techniques have the potential to transform how ecological software is conceived and developed, improve precision, reduce errors, and increase scientific credibility. We describe our re-engineering of the forest landscape model LANDIS (LANdscape DIsturbance and Succession) to illustrate the advantages of using common software engineering practices.

Cultural Responses To Climate Change In The Holocene, Richard Prentice

Anthós

Variable Holocene climate conditions have caused cultures to thrive, adapt or fail. The invention of agriculture and the domestication of plants and animals allowed sedentary societies to develop and are the result of the climate becoming warmer after the last glaciation. The subsequent cooling of the Younger Dryas forced humans to concentrate into geographic areas that had an abundant water supply and ultimately favorable conditions for the use of agriculture and widespread domestication of plants and animals. Population densities would have reached a threshold and forced a return to foraging, however the end of the Younger Dryas at 10,000 BP …

Phylogeographic And Phylogenetic Exploration Of Plethodon (Plethodontidae, Caudata) Salamanders In The Pacific Northwest, Tara Anne Pelletier

Dissertations and Theses

Genetic studies of amphibians often reveal substantial population structure due to either historical demographics from changing climate and geographic features over varying timeframes. Eight species of terrestrial salamanders (Family: Plethodontidae, Genus: Plethodon) reside in forests of the Pacific Northwest (PNW). Plethodon vehiculum is the most widespread and abundant terrestrial salamander in the PNW yet evolutionary studies are lacking. Using mitochondrial DNA (mtDNA) sequence data (D-loop and cytb) questions regarding the phylogeography of P. vehiculum and phylogenetics of western Plethodons are explored. Two major clades were defined in P. vehiculum, a southern clade in the Klamath-Siskiyou region and a …

Analysis And Classification Of Sounds Produced By Asian Elephants (Elephas Maximus), Sharon Stuart Glaeser

Dissertations and Theses

Relatively little is known about the vocal repertoire of Asian elephants (Elephas maximus), and a categorization of basic call types and modifications of these call types by quantitative acoustic parameters is needed to examine acoustic variability within and among call types, to examine individuality, to determine communicative function of calls via playback, to compare species and populations, and to develop rigorous call recognition algorithms for monitoring populations.

This study defines an acoustic repertoire of Asian elephants based on acoustic parameters, compares repertoire usage among groups and individuals, and validates structural distinction among call types through comparison of manual and automated …

Research Choice And Finance In University Bioscience, David E. Ervin, Steven T. Buccola, Hui Yang

Economics Faculty Publications and Presentations

Academic bioscience's rising importance for downstream technology and growing private sector relationships have evoked substantial policy attention. We contribute to the scrutiny by asking how university bioscientists design and finance their research, with particular attention to the mutuality of research portfolio choice and funding success. The analysis requires consideration of other major influences on academic science, including scientific norms, human capital, and institutional environment. Drawing on a national survey of university bioscientists, we find that public financial support encourages more basic investigation and private support encourages more applied investigation. Yet downstream research is only moderately more excludable than upstream. Once …

Mangrove-Exported Nutrient Incorporation By Sessile Coral Reef Invertebrates, Elise F. Granek, Jana E. Compton, Donald L. Phillips

Environmental Science and Management Faculty Publications and Presentations

Coastal mangrove forests were historically considered as a source of organic matter (OM) for adjacent marine systems due to high net primary production; yet recent research suggesting little uptake through the food web because of low nutritional quality, challenges the concept of trophic linkage between mangrove forests and coral reefs. To examine the importance of mangrove forests to coral reef nutrient availability, we examined sessile reef-forming invertebrate consumers including hard corals, sponges, a bivalve mollusc, polychaete annelid and tunicate, and potential sources of OM (decaying mangrove leaves, microalgae, macroalgae, and seagrass) in Bocas del Toro, Panama. Using stable isotope analyses …

Preliminary Characterization Of Mitochondrial Atp-Sensitive Potassium Channel (Mitokatp) Activity In Mouse Heart Mitochondria, Venkat Raghav Aachi

Dissertations and Theses

Myocardial ischemia, infarction, heart failure and arrhythmias are the manifestations of coronary artery disease. Reduction of ischemic damage is a major concern of cardiovascular biology research. As per recent studies, the mitochondrial ATP-sensitive potassium channel (mitoK_ATP) opening is believed to play key role in the physiology of cardioprotection, protection against ischemia-reperfusion injury or apoptosis. However, the structural information of mitoK_ATP is not precisely known. Elucidating the structural integrity and functioning of the mitoK_ATP is therefore a major goal of cardiovascular biology research. The known structure and function of the cell ATP-sensitive potassium channel (cellK_ATP) …

Molecular Coevolution Of Pacific Northwest Hantaviruses And Their Host, The Deer Mouse, Peromyscus Maniculatus, Philip Darren Jones

Dissertations and Theses

Sin Nombre virus (SNV, family Bunyaviridae, genus Hantavirus), hosted by the deer mouse, Peromyscus maniculatus (family Cricetidae, Subfamily Neotominae), is the primary etiological agent of Hantavirus pulmonary syndrome (HPS) in the western United States. HPS, with known pathogenicity only to humans and for which there is no cure or prophylaxis, affects the epithelium of the lungs by making the capillaries leaky, thereby resulting in bilateral infiltrates, and eventually leading to respiratory failure and death by drowning in approximately 38% of hospitalized patients.

In the Americas, Peromyscus has been co-evolving with hantaviruses for approximately 12–20 million years, since the first …

One Rna Plays Three Roles To Provide Catalytic Activity To A Group I Intron Lacking An Endogenous Internal Guide Sequence, Nilesh Vaidya, Niles Lehman

Chemistry Faculty Publications and Presentations

Catalytic RNA molecules possess simultaneously a genotype and a phenotype. However, a single RNA genotype has the potential to adopt two or perhaps more distinct phenotypes as a result of differential folding and/or catalytic activity. Such multifunctionality would be particularly significant if the phenotypes were functionally inter-related in a common biochemical pathway. Here, this phenomenon is demonstrated by the ability of the Azoarcus group I ribozyme to function when its canonical internal guide sequence (GUG) has been removed from the 5? end of the molecule, and added back exogenously in trans. The presence of GUG triplets in noncovalent fragments of …

Dna Before Proteins? Recent Discoveries In Nucleic Acid Catalysis Strengthen The Case, Aaron Steven Burton, Niles Lehman

Chemistry Faculty Publications and Presentations

An RNA-DNA World could arise from an all-RNA system with the development of as few as three ribozymes— a DNA-dependent RNA polymerase, an RNA-dependent DNA polymerase, and a catalyst for the production of DNA nucleotides. A significant objection to DNA preceding proteins is that RNA has not been shown to catalyze the production of DNA. However, RNA- and DNAzymes have been recently discovered that catalyze chemical reactions capable of forming deoxyribose, such as mixed aldol condensation of 5’-glyceryl- and 3’- glycoaldehyde-terminated DNA strands. Thus, the only remaining obstacles to RNA-catalyzed in vitro DNA synthesis are alterations of substrate and template …