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Physical Sciences and Mathematics

Portland State University

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Articles 1 - 30 of 221

Full-Text Articles in Life Sciences

Fire And Land Cover Change In The Palouse Prairie–Forest Ecotone, Washington And Idaho, Usa, Penelope Morgan, Emily K. Heyerdahl, Eva K. Strand, Stephen C. Bunting, James P. Riser Ii, John T. Abatzoglou, Max Nielsen-Pincus, Mara Johnson Jan 2020

Fire And Land Cover Change In The Palouse Prairie–Forest Ecotone, Washington And Idaho, Usa, Penelope Morgan, Emily K. Heyerdahl, Eva K. Strand, Stephen C. Bunting, James P. Riser Ii, John T. Abatzoglou, Max Nielsen-Pincus, Mara Johnson

Environmental Science and Management Faculty Publications and Presentations

Background: Prairie–forest ecotones are ecologically important for biodiversity and ecological processes. While these ecotones cover small areas, their sharp gradients in land cover promote rich ecological interaction and high conservation value. Our objective was to understand how historical and current fire occurrences and human development influenced the Palouse Prairie–forest ecotone. We used General Land Office survey field notes about the occurrence of bearing trees to locate historical (1870s to 1880s) prairie, pine savanna, and forest at the eastern edge of the bioregion. We combined LANDFIRE Existing Vegetation classes to contrast historical land cover with current land cover. We ...


Quantitative And Qualitative Approaches To Assess Tree Vigor And Stand Health In Dry Pine Forests, Nancy Grulke, Craig Bienz, Kate Hrinkevich, Jason Maxfield, Kellie Uyeda Jan 2020

Quantitative And Qualitative Approaches To Assess Tree Vigor And Stand Health In Dry Pine Forests, Nancy Grulke, Craig Bienz, Kate Hrinkevich, Jason Maxfield, Kellie Uyeda

Biology Faculty Publications and Presentations

Despite a critical need to evaluate effectiveness of forest treatments in improving stand health, practitioners lack quantitative, repeatable metrics to assess tree vigor and stand health. We evaluated canopy and whole tree attributes of ponderosa pine (Pinus ponderosa Dougl. Ex Laws) related to carbon balance, water balance, and susceptibility to insects and pathogens in dry, pine-dominated forest stands during a multi-year drought, an environmental challenge to stand resilience. Metrics of trees in two unmanaged, and seven treated forested stands, in both uplands and lowlands to develop the quantitative approach. Whole tree and crown attributes including needle length and color, branchlet ...


Widespread Severe Wildfires Under Climate Change Lead To Increased Forest Homogeneity In Dry Mixed-Conifer Forests, Brooke Alyce Cassell, Robert M. Scheller, Melissa S. Lucash, Matthew Hurteau, E. Louise Loudermilk Nov 2019

Widespread Severe Wildfires Under Climate Change Lead To Increased Forest Homogeneity In Dry Mixed-Conifer Forests, Brooke Alyce Cassell, Robert M. Scheller, Melissa S. Lucash, Matthew Hurteau, E. Louise Loudermilk

Environmental Science and Management Faculty Publications and Presentations

Climate warming in the western United States is causing changes to the wildfire regime in mixed-conifer forests. Rising temperatures, longer fire seasons, increased drought, as well as fire suppression and changes in land use, have led to greater and more severe wildfire activity, all contributing to altered forest composition over the past century. To understand future interactions among climate, wildfire, and vegetation in a fire-prone landscape in the southern Blue Mountains of central Oregon, we used a spatially explicit forest landscape model, LANDIS-II, to simulate forest and fire dynamics under current management practices and two projected climate scenarios. The results ...


Social Vulnerability To Large Wildfires In The Western Usa, Palaiologos Palaiologou, Alan A. Ager, Max Nielsen-Pincus, Cody Evers, Michelle A. Day Sep 2019

Social Vulnerability To Large Wildfires In The Western Usa, Palaiologos Palaiologou, Alan A. Ager, Max Nielsen-Pincus, Cody Evers, Michelle A. Day

Environmental Science and Management Faculty Publications and Presentations

Federal land managers in the US can be informed with quantitative assessments of the social conditions of the populations affected by wildfires originating on their administered lands in order to incorporate and adapt their management strategy to achieve a more targeted prioritization of community wildfire protection investments. In addition, these assessments are valuable to socially vulnerable communities for quantifying their exposure to wildfires originating on adjacent land tenures. We assessed fire transmission patterns using fire behavior simulations to understand spatial variations across three diverse study areas (North-central Washington; Central California; and Northern New Mexico) to understand how different land tenures ...


Farmer Attitudes Toward Cooperative Approaches To Herbicide Resistance Management: A Common Pool Ecosystem Service Challenge, David E. Ervin, Elise H. Breshears, George B. Frisvold, Terrance M. Hurley, Katherine E. Dentzman, Jeffrey L. Gunsolus, Raymond A. Jussaume, Micheal D. K. Owen, Jason Norsworthy, Mustofa Mahmud Al Mamun, Wesley Everman Mar 2019

Farmer Attitudes Toward Cooperative Approaches To Herbicide Resistance Management: A Common Pool Ecosystem Service Challenge, David E. Ervin, Elise H. Breshears, George B. Frisvold, Terrance M. Hurley, Katherine E. Dentzman, Jeffrey L. Gunsolus, Raymond A. Jussaume, Micheal D. K. Owen, Jason Norsworthy, Mustofa Mahmud Al Mamun, Wesley Everman

Environmental Science and Management Faculty Publications and Presentations

Dramatic growth in herbicide-resistant (HR) weeds in the United States threatens farm profitability and may undercut environmentally beneficial farming practices. When HR weeds move across farm boundaries due to ecological processes or human action, a common pool resource challenge emerges, requiring farmer cooperation to manage such weeds effectively. We investigate the scope for cooperative management using responses to a national survey on HR weed issues to test a recursive model of three preconditions for collective action: (1) concern about HR weeds migrating from nearby lands; (2) communication with neighbors about HR weeds; and (3) belief that cooperation is necessary for ...


Fine-Scale Assessment Of Cross-Boundary Wildfire Events In The Western United States, Palaiologos Palaiologou, Alan A. Ager, Cody Evers, Max Nielsen-Pincus, Michelle A. Day, Haiganoush K. Preisler Jan 2019

Fine-Scale Assessment Of Cross-Boundary Wildfire Events In The Western United States, Palaiologos Palaiologou, Alan A. Ager, Cody Evers, Max Nielsen-Pincus, Michelle A. Day, Haiganoush K. Preisler

Environmental Science and Management Faculty Publications and Presentations

We report a fine-scale assessment of cross-boundary wildfire events for the western US. We used simulation modeling to quantify the extent of fire exchange among major federal, state, and private land tenures and mapped locations where fire ignitions can potentially affect populated places. We examined how parcel size affects wildfire transmission and partitioned the relative amounts of transmitted fire between human and natural ignitions. We estimated that 85 % of the total predicted wildfire activity, as measured by area burned, originates from four land tenures (Forest Service, Bureau of Land Management, private, and state lands) and 63 % of the total amount ...


Four-Fold Increase In Solar Forcing On Snow In Western U.S. Burned Forests Since 1999, Kelly E. Gleason, Joseph R. Mcconnell, Monica M. Arienzo, Nathan Chellman, Wendy M. Calvin Jan 2019

Four-Fold Increase In Solar Forcing On Snow In Western U.S. Burned Forests Since 1999, Kelly E. Gleason, Joseph R. Mcconnell, Monica M. Arienzo, Nathan Chellman, Wendy M. Calvin

Environmental Science and Management Faculty Publications and Presentations

Forest fires are increasing across the American West due to climate warming and fire suppression. Accelerated snow melt occurs in burned forests due to increased light transmission through the canopy and decreased snow albedo from deposition of light-absorbing impurities. Using satellite observations, we document up to an annual 9% growth in western forests burned since 1984, and 5 day earlier snow disappearance persisting for >10 years following fire. Here, we show that black carbon and burned woody debris darkens the snowpack and lowers snow albedo for 15 winters following fire, using measurements of snow collected from seven forested sites that ...


Limited Sequence Diversity Within A Population Supports Prebiotic Rna Reproduction, Ryo Mizuuchi, Niles Lehman Jan 2019

Limited Sequence Diversity Within A Population Supports Prebiotic Rna Reproduction, Ryo Mizuuchi, Niles Lehman

Chemistry Faculty Publications and Presentations

The origins of life require the emergence of informational polymers capable of reproduction. In the RNA world on the primordial Earth, reproducible RNA molecules would have arisen from a mixture of compositionally biased, poorly available, short RNA sequences in prebiotic environments. However, it remains unclear what level of sequence diversity within a small subset of population is required to initiate RNA reproduction by prebiotic mechanisms. Here, using a simulation for template-directed recombination and ligation, we explore the effect of sequence diversity in a given population for the onset of RNA reproduction. We show that RNA reproduction is improbable in low ...


Dynamics Of Prochlorococcus Diversity And Photoacclimation During Short-Term Shifts In Water Column Stratification At Station Aloha, Anne W. Thompson, Ger Van Den Engh, Nathan A. Ahlgren, Kathleen Kouba, Samantha Ward, Samuel T. Wilson, David M. Karl Dec 2018

Dynamics Of Prochlorococcus Diversity And Photoacclimation During Short-Term Shifts In Water Column Stratification At Station Aloha, Anne W. Thompson, Ger Van Den Engh, Nathan A. Ahlgren, Kathleen Kouba, Samantha Ward, Samuel T. Wilson, David M. Karl

Biology Faculty Publications and Presentations

The cyanobacterium Prochlorococcus is the dominant phototroph in surface waters of the vast oligotrophic oceans, the foundation of marine food webs, and an important component of global biogeochemical cycles. The prominence of Prochlorococcus across the environmental gradients of the open ocean is attributed to its extensive genetic diversity and flexible chlorophyll physiology, enabling light capture over a wide range of intensities. What remains unknown is the balance between temporal dynamics of genetic diversity and chlorophyll physiology in the ability of Prochlorococcus to respond to a variety of short (approximately 1 day) and longer (months to year) changes in the environment ...


Spatial Factor Models For High-Dimensional And Large Spatial Data: An Application In Forest Variable Mapping, Daniel Taylor-Rodríguez, Andrew O. Finley, Abhirup Datta, Chad Babcock, Hans-Erik Andersen, Bruce D. Cook, Douglas C. Morton, Sudipto Banerjee Nov 2018

Spatial Factor Models For High-Dimensional And Large Spatial Data: An Application In Forest Variable Mapping, Daniel Taylor-Rodríguez, Andrew O. Finley, Abhirup Datta, Chad Babcock, Hans-Erik Andersen, Bruce D. Cook, Douglas C. Morton, Sudipto Banerjee

Mathematics and Statistics Faculty Publications and Presentations

Gathering information about forest variables is an expensive and arduous activity. As such, directly collecting the data required to produce high-resolution maps over large spatial domains is infeasible. Next generation collection initiatives of remotely sensed Light Detection and Ranging (LiDAR) data are specifically aimed at producing complete-coverage maps over large spatial domains. Given that LiDAR data and forest characteristics are often strongly correlated, it is possible to make use of the former to model, predict, and map forest variables over regions of interest. This entails dealing with the high-dimensional (∼102 ) spatially dependent LiDAR outcomes over a large number of ...


Patterns And Drivers Of Recent Disturbances Across The Temperate Forest Biome, Andreas Sommerfeld, Cornelius Senf, Brian Buma, Anthony W. D'Amato, Tiphaine Despres, Ignacio Díaz-Hormazábal, Shawn Fraver, Lee E. Frelich, Alvaro G. Gutiérrez, Sarah J. Hart, Brian J. Harvey, Hong S. He, Tomáš Hlásny, Andrés Holz, Multiple Additional Authors Oct 2018

Patterns And Drivers Of Recent Disturbances Across The Temperate Forest Biome, Andreas Sommerfeld, Cornelius Senf, Brian Buma, Anthony W. D'Amato, Tiphaine Despres, Ignacio Díaz-Hormazábal, Shawn Fraver, Lee E. Frelich, Alvaro G. Gutiérrez, Sarah J. Hart, Brian J. Harvey, Hong S. He, Tomáš Hlásny, Andrés Holz, Multiple Additional Authors

Geography Faculty Publications and Presentations

Increasing evidence indicates that forest disturbances are changing in response to global change, yet local variability in disturbance remains high. We quantified this considerable variability and analyzed whether recent disturbance episodes around the globe were consistently driven by climate, and if human influence modulates patterns of forest disturbance. We combined remote sensing data on recent (2001–2014) disturbances with in-depth local information for 50 protected landscapes and their surroundings across the temperate biome. Disturbance patterns are highly variable, and shaped by variation in disturbance agents and traits of prevailing tree species. However, high disturbance activity is consistently linked to warmer ...


Water Flow And Biofilm Cover Influence Environmental Dna Detection In Recirculating Streams, Arial Shogren, Jennifer L. Tank, Scott P. Egan, Olivia August, Emma J. Rosi, Brittany R. Hanrahan, Mark A. Renshaw, Crysta A. Gantz, Diogo Bolster Jul 2018

Water Flow And Biofilm Cover Influence Environmental Dna Detection In Recirculating Streams, Arial Shogren, Jennifer L. Tank, Scott P. Egan, Olivia August, Emma J. Rosi, Brittany R. Hanrahan, Mark A. Renshaw, Crysta A. Gantz, Diogo Bolster

Environmental Science and Management Faculty Publications and Presentations

The increasing use of environmental DNA (eDNA) for determination of species presence in aquatic ecosystems is an invaluable technique for both ecology as a field and for the management of aquatic ecosystems. We examined the degradation dynamics of fish eDNA using an experimental array of recirculating streams, also using a “nested” primer assay to estimate degradation among eDNA fragment sizes. We introduced eDNA into streams with a range of water velocities (0.1–0.8 m s–1) and substrate biofilm coverage (0–100%) and monitored eDNA concentrations over time (∼10 d) to assess how biophysical conditions influence eDNA persistence ...


Using Transboundary Wildfire Exposure Assessments To Improve Fire Management Programs: A Case Study In Greece, Palaiologos Palaiologou, Alan A. Ager, Max Nielsen-Pincus, Cody Evers, Kostas Kalabokidis Jul 2018

Using Transboundary Wildfire Exposure Assessments To Improve Fire Management Programs: A Case Study In Greece, Palaiologos Palaiologou, Alan A. Ager, Max Nielsen-Pincus, Cody Evers, Kostas Kalabokidis

Environmental Science and Management Faculty Publications and Presentations

Numerous catastrophic wildfires in Greece have demonstrated that relying on fire suppression as the primary risk-management strategy is inadequate and that existing wildfire-risk governance needs to be re-examined. In this research, we used simulation modelling to assess the spatial scale of wildfire exposure to communities and cultural monuments in Chalkidiki, Greece. The study area typifies many areas in Greece in terms of fire regimes, ownership patterns and fire-risk mitigation. Fire-transmission networks were built to quantify connectivity among land tenures and populated places. We found that agricultural and unmanaged wildlands are key land categories that transmit fire exposure to other land ...


Multivalency Regulates Activity In An Intrinsically Disordered Transcription Factor, Sarah Clark, Janette B. Myers, Ashleigh King, Radovan Fiala, Jiri Novacek, Grant Pearce, Steve L. Reichow, Elisar J. Barbar May 2018

Multivalency Regulates Activity In An Intrinsically Disordered Transcription Factor, Sarah Clark, Janette B. Myers, Ashleigh King, Radovan Fiala, Jiri Novacek, Grant Pearce, Steve L. Reichow, Elisar J. Barbar

Chemistry Faculty Publications and Presentations

The transcription factor ASCIZ (ATMIN, ZNF822) has an unusually high number of recognition motifs for the product of its main target gene, the hub protein LC8 (DYNLL1). Using a combination of biophysical methods, structural analysis by NMR and electron microscopy, and cellular transcription assays, we developed a model that proposes a concerted role of intrinsic disorder and multiple LC8 binding events in regulating LC8 transcription. We demonstrate that the long intrinsically disordered C-terminal domain of ASCIZ binds LC8 to form a dynamic ensemble of complexes with a gradient of transcriptional activity that is inversely proportional to LC8 occupancy. The preference ...


The Economic Contribution Of Stewardship Contracting: Two Case Studies From The Mount Hood National Forest, Jean M. Daniels, Max Nielsen-Pincus, Mike Paruszkiewicz, Nathan Poage May 2018

The Economic Contribution Of Stewardship Contracting: Two Case Studies From The Mount Hood National Forest, Jean M. Daniels, Max Nielsen-Pincus, Mike Paruszkiewicz, Nathan Poage

Environmental Science and Management Faculty Publications and Presentations

We conducted an economic analysis of two case study stewardship contracts on the Mount Hood National Forest in western Oregon. Stewardship contracting has been embraced by some federal managers to achieve restoration goals while providing economic benefits to local communities. Little is known about economic contributions from stewardship contracts, including how they compare against Secure Rural Schools funding or the century-old payments to counties revenue sharing system. Using expenditure data from sale purchasers, contractors, and fiscal agents, we developed methodology to track spending and used IMPLAN software to estimate economic contributions and multipliers. Results showed that (1) commercial thinning, service ...


Assessing Transboundary Wildfire Exposure In The Southwestern United States, Alan A. Ager, Palaiologos Palaiologou, Cody Evers, Michelle A. Day, Ana M.G. Barros Apr 2018

Assessing Transboundary Wildfire Exposure In The Southwestern United States, Alan A. Ager, Palaiologos Palaiologou, Cody Evers, Michelle A. Day, Ana M.G. Barros

Environmental Science and Management Faculty Publications and Presentations

We assessed transboundary wildfire exposure among federal, state, and private lands and 447 communities in the state of Arizona, southwestern United States. The study quantified the relative magnitude of transboundary (incoming, outgoing) versus nontransboundary (i.e., self-burning) wildfire exposure based on land tenure or community of the simulated ignition and the resulting fire perimeter. We developed and described several new metrics to quantify and map transboundary exposure. We found that incoming transboundary fire accounted for 37% of the total area burned on large parcels of federal and state lands, whereas 63% of the area burned was burned by ignitions within ...


Bioassessment Of A Drinking Water Reservoir Using Plankton: High Throughput Sequencing Vs. Traditional Morphological Method, Wanli Gao, Zhaojin Chen, Yuying Li, Yangdong Pan, Jingya Zhu, Shijun Guo, Lanqun Hu, Jin Huang Jan 2018

Bioassessment Of A Drinking Water Reservoir Using Plankton: High Throughput Sequencing Vs. Traditional Morphological Method, Wanli Gao, Zhaojin Chen, Yuying Li, Yangdong Pan, Jingya Zhu, Shijun Guo, Lanqun Hu, Jin Huang

Environmental Science and Management Faculty Publications and Presentations

Drinking water safety is increasingly perceived as one of the top global environmental issues. Plankton has been commonly used as a bioindicator for water quality in lakes and reservoirs. Recently, DNA sequencing technology has been applied to bioassessment. In this study, we compared the effectiveness of the 16S and 18S rRNA high throughput sequencing method (HTS) and the traditional optical microscopy method (TOM) in the bioassessment of drinking water quality. Five stations reflecting different habitats and hydrological conditions in Danjiangkou Reservoir, one of the largest drinking water reservoirs in Asia, were sampled May 2016. Non-metric multi-dimensional scaling (NMDS) analysis showed ...


Connecting Chemistry To Community With Deliberative Democracy, Regis Komperda, Jack Barbera, Erin Shortlidge, Gwen Shusterman, Stem Education And Equity Institute, Portland State University Jan 2018

Connecting Chemistry To Community With Deliberative Democracy, Regis Komperda, Jack Barbera, Erin Shortlidge, Gwen Shusterman, Stem Education And Equity Institute, Portland State University

Biology Faculty Publications and Presentations

Science education communities have called for rethinking curricula to improve student understanding of the nature of science and the role of science in addressing controversial modern issues such as climate change, energy policy, and pollution levels. One approach to meeting this call is integrating these topics into class activities that require students to use discussion and scientific approaches to solve problems and deliberate potential policy solutions. Deliberative democracy (DD) is one such active learning approach in which students work in peer groups to reach a consensus on a scientific topic relevant to both real-world issues and course content. During DD ...


Northwest Forest Plan The First 20 Years (1994-2013): Watershed Condition Status And Trend, Stephanie A. Miller, Sean N. Gordon, Peter Eldred, Ronald M. Beloin, Steve Wilcox, Mark Raggon, Heidi Andersen, Ariel Muldoon Nov 2017

Northwest Forest Plan The First 20 Years (1994-2013): Watershed Condition Status And Trend, Stephanie A. Miller, Sean N. Gordon, Peter Eldred, Ronald M. Beloin, Steve Wilcox, Mark Raggon, Heidi Andersen, Ariel Muldoon

Institute for Sustainable Solutions Publications and Presentations

We used two data sets to evaluate stream and upslope/riparian condition for sixth-field watersheds in each aquatic province within the Northwest Forest Plan (NWFP) area. The stream evaluation was based on stream sampling data collected from 2002 to the 2013 (214 watersheds) as part of an eight year repeating (rotating) sample design. We are currently halfway through our second rotation of stream sampling, and have repeated 110 watersheds since the second rotation began in 2009. The analysis presented in this report uses roughly half the number of watersheds as was originally intended by the sample design since re-visitation will ...


Prozac In The Water: Chronic Fluoxetine Exposure And Predation Risk Interact To Shape Behaviors In An Estuarine Crab, Joseph R. Peters, Elise F. Granek, Catherine E. De Rivera, Matthew Rollins Sep 2017

Prozac In The Water: Chronic Fluoxetine Exposure And Predation Risk Interact To Shape Behaviors In An Estuarine Crab, Joseph R. Peters, Elise F. Granek, Catherine E. De Rivera, Matthew Rollins

Environmental Science and Management Faculty Publications and Presentations

Predators exert considerable top-down pressure on ecosystems by directly consuming prey or indirectly influencing their foraging behaviors and habitat use. Prey is, therefore, forced to balance predation risk with resource reward. A growing list of anthropogenic stressors such as rising temperatures and ocean acidification has been shown to influence prey risk behaviors and subsequently alter important ecosystem processes. Yet, limited attention has been paid to the effects of chronic pharmaceutical exposure on risk behavior or as an ecological stressor, despite widespread detection and persistence of these contaminants in aquatic environments. In the laboratory, we simulated estuarine conditions of the shore ...


Life’S Late Digital Revolution And Why It Matters For The Study Of The Origins Of Life, David A. Baum, Niles Lehman Aug 2017

Life’S Late Digital Revolution And Why It Matters For The Study Of The Origins Of Life, David A. Baum, Niles Lehman

Chemistry Faculty Publications and Presentations

The information contained in life exists in two forms, analog and digital. Analog information is manifest mainly in the differing concentrations of chemicals that get passed from generation to generation and can vary from cell to cell. Digital information is encoded in linear polymers such as DNA and RNA, whose side chains come in discrete chemical forms. Here, we argue that the analog form of information preceded the digital. Acceptance of this dichotomy, and this progression, can help direct future studies on how life originated and initially complexified on the primordial Earth, as well as expected trajectories for other, independent ...


Assessing The Potential Of Land Use Modification To Mitigate Ambient No2 And Its Consequences For Respiratory Health, Meenakshi Rao, Linda A. George, Vivek Shandas, Todd N. Rosenstiel Jul 2017

Assessing The Potential Of Land Use Modification To Mitigate Ambient No2 And Its Consequences For Respiratory Health, Meenakshi Rao, Linda A. George, Vivek Shandas, Todd N. Rosenstiel

Urban Studies and Planning Faculty Publications and Presentations

Understanding how local land use and land cover (LULC) shapes intra-urban concentrations of atmospheric pollutants—and thus human health—is a key component in designing healthier cities. Here, NO2 is modeled based on spatially dense summer and winter NO2 observations in Portland-Hillsboro-Vancouver (USA), and the spatial variation of NO2 with LULC investigated using random forest, an ensemble data learning technique. The NO2 random forest model, together with BenMAP, is further used to develop a better understanding of the relationship among LULC, ambient NO2 and respiratory health. The impact of land use modifications on ambient NO ...


Effectiveness Of Indoor Plants For Passive Removal Of Indoor Ozone, Omed A. Abbass, David J. Sailor, Elliott T. Gall Jul 2017

Effectiveness Of Indoor Plants For Passive Removal Of Indoor Ozone, Omed A. Abbass, David J. Sailor, Elliott T. Gall

Mechanical and Materials Engineering Faculty Publications and Presentations

Indoor vegetation is often proposed as a passive approach for improving indoor air quality. While studies of outdoor environments indicate that vegetation can be an important sink of outdoor ozone, there is scant data in the literature concerning the dynamics of ozone uptake by indoor plants. This study determined ozone deposition velocities (vd) for five common indoor plants (Peace Lily, Ficus, Calathia, Dieffenbachia, Golden Pothos). The transient vd was calculated, using measured leaf areas for each plant, for exposures mimicking three diurnal cycles where ozone concentrations in chamber tests were elevated for 8 h followed by 16 h ...


Columbia River Basin Salmon And Steelhead Long-Term Recovery Situation Assessment, Oregon Solutions, William D. Ruckelshaus Center Jun 2017

Columbia River Basin Salmon And Steelhead Long-Term Recovery Situation Assessment, Oregon Solutions, William D. Ruckelshaus Center

National Policy Consensus Center Publications and Reports

In the fall of 2012, after consulting with a wide range of salmon recovery partners, NOAA Fisheries asked Oregon Consensus and the William D. Ruckelshaus Center (university-based, neutral, third-party institutions devoted to promoting collaborative governance and consensusbased public policy) to conduct an independent, impartial situation assessment to explore regional views about how best to approach comprehensive, long-term salmon and steelhead recovery in the Basin. The centers assembled an Assessment Team comprised of practitioners and academics from Washington, Oregon and Idaho.

The Assessment Team conducted 206 semi-structured interviews with individuals selected for their knowledge of, engagement in, and/or concern for ...


Simplified Reversed Chloroquines To Overcome Malaria Resistance To Quinoline-Based Drugs, Bornface Gunsaru, Steven J. Burgess, Westin Morrill, Jane X. Kelly, Shawheen Shomloo, Martin J. Smilkstein, Katherine May Liebman, David H. Peyton May 2017

Simplified Reversed Chloroquines To Overcome Malaria Resistance To Quinoline-Based Drugs, Bornface Gunsaru, Steven J. Burgess, Westin Morrill, Jane X. Kelly, Shawheen Shomloo, Martin J. Smilkstein, Katherine May Liebman, David H. Peyton

Chemistry Faculty Publications and Presentations

Building on our earlier work of attaching a chemosensitizer (reversal agent) to a known drug pharmacophore, we have now expanded the structure-activity relationship study to include simplified versions of the chemosensitizer. The change from two aromatic rings in this head group to a single ring does not appear to detrimentally affect the antimalarial activity of the compounds. Data from in vitro heme binding and beta-hematin inhibition assays suggest that the single aromatic RCQ compounds retain activities against Plasmodium falciparum similar to those of CQ, although other mechanisms of action may be relevant to their activities.


Topological And Thermodynamic Factors That Influence The Evolution Of Small Networks Of Catalytic Rna Species, Jessica Anne Mellor Yeates, Philippe Nghe, Niles Lehman Mar 2017

Topological And Thermodynamic Factors That Influence The Evolution Of Small Networks Of Catalytic Rna Species, Jessica Anne Mellor Yeates, Philippe Nghe, Niles Lehman

Chemistry Faculty Publications and Presentations

An RNA-directed recombination reaction can result in a network of interacting RNA species. It is now becoming increasingly apparent that such networks could have been an important feature of the RNA world during the nascent evolution of life on the Earth. However, the means by which such small RNA networks assimilate other available genotypes in the environment to grow and evolve into the more complex networks that are thought to have existed in the prebiotic milieu are not known. Here, we used the ability of fragments of the Azoarcus group I intron ribozyme to covalently self-assemble via genotype-selfish and genotype-cooperative ...


Divergent Trends In Ecosystem Services Under Different Climate-Management Futures In A Fire-Prone Forest Landscape, Joshua S. Halofsky, Jessica E. Halofsky, Miles A. Hemstrom, Anita T. Morzillo, Xiaoping Zhou, Daniel C. Donato Feb 2017

Divergent Trends In Ecosystem Services Under Different Climate-Management Futures In A Fire-Prone Forest Landscape, Joshua S. Halofsky, Jessica E. Halofsky, Miles A. Hemstrom, Anita T. Morzillo, Xiaoping Zhou, Daniel C. Donato

Institute for Natural Resources Publications

While ecosystem services and climate change are often examined independently, quantitative assessments integrating these fields are needed to inform future land management decisions. Using climate-informed state-and-transition simulations, we examined projected trends and trade-offs for a suite of ecosystem services under four climate change scenarios and two management scenarios (active management emphasizing fuel treatments and no management other than fire suppression) in a fire-prone landscape of dry and moist mixed-conifer forests in central Oregon, USA. Focal ecosystem services included fire potential (regulating service), timber volume (provisioning service), and potential wildlife habitat (supporting service). Projections without climate change suggested active management in ...


Factors Affecting Snowy Plover Chick Survival In A Managed Population, Stephen J. Dinsmore, Eleanor P. Gaines, Scott F. Pearson, David J. Lauten, Kathleen J. Castelein Jan 2017

Factors Affecting Snowy Plover Chick Survival In A Managed Population, Stephen J. Dinsmore, Eleanor P. Gaines, Scott F. Pearson, David J. Lauten, Kathleen J. Castelein

Institute for Natural Resources Publications

Understanding survival of precocial chicks in the period immediately following hatching has important conservation implications because population growth is often sensitive to post-hatching survival. We studied federally threatened Western Snowy Plover (Charadrius nivosus nivosus) broods at the northern limit of their range in coastal Oregon (n ¼ 1,157) and Washington (n ¼ 84) from 1991 to 2011 in an attempt to understand seasonal, annual, and spatial patterns of chick survival. In Oregon, plover chick survival increased with age, varied between sites, and was greater at sites with predator management. The mean probability of surviving from hatch to fledging at ...


The T6a Modification Acts As A Positive Determinant For The Anticodon Nuclease Prrc, And Is Distinctively Nonessential In Streptococcus Mutans, Jo Marie Bacusmo, Silvia S. Orsini, Jennifer Hu, Michael Demott, Patrick C. Thiaville, Ameer Elfarash, Mellie June Paulines, Diego Rojas-Benítez, Birthe Meineke, Christopher Deutsch, Dirk Iwata-Reuyl, Patrick A. Limbach, Peter C. Dedon, Kelly C. Rice, Stewart Shuman, Valérie De Crécy-Lagard Jan 2017

The T6a Modification Acts As A Positive Determinant For The Anticodon Nuclease Prrc, And Is Distinctively Nonessential In Streptococcus Mutans, Jo Marie Bacusmo, Silvia S. Orsini, Jennifer Hu, Michael Demott, Patrick C. Thiaville, Ameer Elfarash, Mellie June Paulines, Diego Rojas-Benítez, Birthe Meineke, Christopher Deutsch, Dirk Iwata-Reuyl, Patrick A. Limbach, Peter C. Dedon, Kelly C. Rice, Stewart Shuman, Valérie De Crécy-Lagard

Chemistry Faculty Publications and Presentations

Endoribonuclease toxins (ribotoxins) are produced by bacteria and fungi to respond to stress, eliminate non-self competitor species, or interdict virus infection. PrrC is a bacterial ribotoxin that targets and cleaves tRNALys UUU in the anticodon loop. In vitro studies suggested that the post-transcriptional modification threonylcarbamoyl adenosine (t6A) is required for PrrC activity but this prediction had never been validated in vivo. Here, by using t6A-deficient yeast derivatives, it is shown that t6A is a positive determinant for PrrC proteins from various bacterial species. Streptococcus mutans is one of the few bacteria where the t ...


Reduced Snow Cover Alters Root-Microbe Interactions And Decreases Nitrification Rates In A Northern Hardwood Forest, Patrick O. Sorensen, Pamela H. Templer, Lynn M. Christenson, Jorge Durán, Timothy J. Fahey, Melany C. Fisk, Peter M. Groffman, Jennifer L. Morse, Adrien C. Finzi Dec 2016

Reduced Snow Cover Alters Root-Microbe Interactions And Decreases Nitrification Rates In A Northern Hardwood Forest, Patrick O. Sorensen, Pamela H. Templer, Lynn M. Christenson, Jorge Durán, Timothy J. Fahey, Melany C. Fisk, Peter M. Groffman, Jennifer L. Morse, Adrien C. Finzi

Environmental Science and Management Faculty Publications and Presentations

Snow cover is projected to decline during the next century in many ecosystems that currently experience a seasonal snowpack. Because snow insulates soils from frigid winter air temperatures, soils are expected to become colder and experience more winter soil freeze-thaw cycles as snow cover continues to decline. Tree roots are adversely affected by snowpack reduction, but whether loss of snow will affect root-microbe interactions remains largely unknown. The objective of this study was to distinguish and attribute direct (e.g., winter snow-and/ or soil frost-mediated) vs. indirect (e.g., root-mediated) effects of winter climate change on microbial biomass, the potential ...