1,585 research outputs found

    Western Educational Longitudinal Study (WELS) Baseline Survey of Transfer Students Entering Western in the Fall, 2013: Descriptive Statistics

    Get PDF
    The WELS Baseline Survey of Transfers Entering Western in the Fall, 2013 (Transfer Survey) is the companion survey to the Office of Survey Research’s (OSR) survey of incoming freshmen. Together, these surveys elicit information from students prior to the start of their Western academic careers and provide an initial contact in a longitudinal survey design that follows students through graduation and into their initial years as alumni. The Transfer Survey is designed with three purposes in mind: (1) to provide baseline observations of students prior to the Western experience that can be used to forecast and enhance student success; (2) to provide data that can assist university assessment and accreditation endeavors; and (3) to assess student needs based upon their selfreported characteristics, perceptions, and concerns. To accomplish these, the Transfer Survey integrates questions into seven sections: prior engagement and experiences, the college application process, course scheduling, academic skills and goals, major choice, expenses and employment, and demographics. In addition to these, various Western offices submitted questions that dealt with academic advising and the use of technology. The questions on the Transfer Survey are a mixture of open-ended, numerical and multiple choice types. This report lists all questions and reports basic descriptive statistics from equations which lend themselves to numerical analysis. Responses to open ended questions are available upon request

    Regulation and Measurement of Nitrification in Terrestrial Systems

    Get PDF
    Nitric oxide (NO) is a relatively short-lived trace gas that reacts with oxygen in the troposphere to produce the air pollutant ozone. It also reacts with water vapor to form nitric and nitrous acids, which acidify precipitation and increase N deposition. Models currently used to predict soil NO fluxes are based on the assumption that NO flux is proportional to the gross rate of nitrification or N mineralization; however, this assumption has not been tested because of the difficulty in measuring gross N-cycling rates in situ. We measured soil NO fluxes, gross and net N-cycling rates, and a variety of other soil characteristics in the forest floor and intact soil cores at nine undisturbed forest and rangeland ecosystems of New Mexico, Utah, and Oregon, USA, to determine which soil variables were most closely related to soil NO flux. Soil NO fluxes ranged from a low of 0.02 ng N·m22·s21, prior to wetting in a western hemlock–sitka spruce forest on the Oregon coast, to a high of 6.74 ng N·m22·s21, one hour after soil wetting in a juniper woodland of central Oregon. In contrast to our expectations, neither gross nitrification nor gross mineralization was correlated with soil NO flux. Fluxes were positively correlated with net rates of mineralization and nitrification, soil NO3 2 concentrations, bulk density, and pH, and negatively correlated with gross rates of NO3 2 consumption in the forest floor, soil organic carbon (SOC), soil C:N, and soil water content. Principal-component analysis showed that NO flux after water addition (2 cm of water) had a strong negative correlation with microbial demand for N (as indicated by net mineralization, net nitrification, SOC, and C:N). Our results suggest that, even in well-drained soils, NO efflux is limited more by NO consumption than by NO production. As a result, models utilizing the more easily measured net rates, rather than gross rates, may be better predictors of soil NO fluxes across a range of ecosystems

    Western Educational Longitudinal Study (WELS) Baseline Survey of Freshmen Entering Western in the Fall, 2013: Descriptive Statistics

    Get PDF
    The Fall, 2013 Baseline Survey of Freshmen Entering Western (Freshmen Survey) continues the Office of Survey Research’s (OSR) efforts to collect information on all students prior to the start of their academic careers at Western Washington University. This survey represents the initial contact in a longitudinal process that makes inquiries of students at the end of their sophomore year, when they graduate from the university, and one to two years after graduation. The Freshmen Survey is designed with three purposes in mind: (1) to provide baseline observations of students prior to their Western experience which can be used to forecast and enhance student success; (2) to provide data that can assist university assessment and accreditation efforts; (3) to assess student needs based upon their self-reported characteristics, perceptions, and concerns. To accomplish these, the Freshmen Survey integrates questions into five major sections: pre-collegiate engagement and experiences, the college application process, class scheduling and expectations, skills, goals, and expectations, and expenses and employment. In addition to these, Western’s Division of Enrollment and Student Services submitted questions regarding the expected use of technology. The questions on the Freshmen Survey are a mix of open-ended, numerical, and multiple choice responses. This report lists all questions and reports basic descriptive statistics from questions which lend themselves to numerical analysis. Responses to the open ended questions are available upon request

    Effects of environmentally realistic concentrations of neonicotinoid insecticides on an aquatic invertebrate community

    Get PDF
    Neonicotinoid insecticides represent 24 % of the global market, and their use is increasing globally. Among them, clothianidin, imidacloprid, and thiamethoxam are widely used systemic insecticides, but are also used for lawn and garden care, and pest control. Residential usage has been linked to the occurrence of toxic level of pesticides in urban water bodies. Neonicotinoids are highly soluble in water and persistent in soil, and even though they are not intended for use in water bodies, they may enter in the aquatic compartment via spray drift, runoff or leaching, and contribute to downstream aquatic toxicity. Neonicotinoids interfere with the insect nervous system, and exhibit very high selectivity for insect nicotinic acetylcholine receptors. However, although insects appear to be the most sensitive, some studies have shown effects of neonicotinoids on the crustaceans Ceriodaphnia dubia and Daphnia magna, but also on honeybees and bumble bees, flies, and birds. Moreover, neonicotinoid contamination is likely to induce a top-down trophic cascade in a community dominated by invertebrate predators. Very little is known concerning the impact of neonicotinoid mixtures on the environment, and their combined toxicity on invertebrate community. Thus, our study aimed to test the effect of a mixture of imidachloprid, clothianidin and thiamethoxam on an aquatic invertebrate community at concentrations measured in the environment, and explore the community-level effects. The experiment was conducted in outdoor microcosms. The community was sampled before the insecticide application and throughout the month following the treatment. Environmental parameters (water temperature, pH, conductivity, chlorophyll a) were measured in every microcosm on each sampling date. Results will be discussed during the presentation. Keywords: neonicotinoid insecticides, mixture, aquatic invertebrates, community-leve

    Efficacy of compost amended biofiltration swales as green stormwater infrastructure for treatment of toxicants in Salish Sea road run-off

    Get PDF
    Biofiltration swales, or bioswales, use vegetated soil substrates to filter contaminants from stormwater, decrease sediment load, and reduce erosion. Following a storm, runoff moves slowly through the swale at a shallow depth. While stormwater is retained in the bioswales, pollutants are removed by the combined effects of filtration, infiltration, settling, and biotransformation. The system currently being evaluated at the Washington State University (WSU) Puyallup Research and Extension Center (PREC) uses compost to further enhance the ability of bioswales to remove toxicants. WSDOT has created guidelines for constructing compost amended biofiltration swales (CABS) and implemented a field test for CABS along Washington State Route (SR) 518 in 2009. As part of an ongoing study, influent and effluent samples are currently being collected at the field site during storm events and tested for metals, PAHs, pesticides, phthalates, and unknowns (LC-QTOF). Acute toxicity and sub-lethal effects of stormwater were also measured using zebrafish (Danio rerio) bioassays. Along with researchers from University of Washington (UW) we created a laboratory model for CABS at the WSU PREC to verify field test results in a controlled setting and identify ways that the WSDOT design could be improved. This system is exposed to highway runoff from a previously studied high volume source off SR 520 and tested at different flow rates, swale lengths, and slope gradients. Paired chemistry and toxicology data show how stormwater treatment by CABS differ from traditional soil biofiltration methods. Results presented at Salish Sea show how zebrafish developmental biology is affected by stormwater treatments and how CABS design impacts toxicant treatment efficacy

    Probing for Exoplanets Hiding in Dusty Debris Disks: Disk Imaging, Characterization, and Exploration with HST/STIS Multi-Roll Coronagraphy

    Get PDF
    Spatially resolved scattered-light images of circumstellar (CS) debris in exoplanetary systems constrain the physical properties and orbits of the dust particles in these systems. They also inform on co-orbiting (but unseen) planets, systemic architectures, and forces perturbing starlight-scattering CS material. Using HST/STIS optical coronagraphy, we have completed the observational phase of a program to study the spatial distribution of dust in ten CS debris systems, and one "mature" protoplanetrary disk all with HST pedigree, using PSF-subtracted multi-roll coronagraphy. These observations probe stellocentric distances > 5 AU for the nearest stars, and simultaneously resolve disk substructures well beyond, corresponding to the giant planet and Kuiper belt regions in our Solar System. They also disclose diffuse very low-surface brightness dust at larger stellocentric distances. We present new results inclusive of fainter disks such as HD92945 confirming, and better revealing, the existence of a narrow inner debris ring within a larger diffuse dust disk. Other disks with ring-like sub-structures, significant asymmetries and complex morphologies include: HD181327 with a posited spray of ejecta from a recent massive collision in an exo-Kuiper belt; HD61005 suggested interacting with the local ISM; HD15115 & HD32297, discussed also in the context of environmental interactions. These disks, and HD15745, suggest debris system evolution cannot be treated in isolation. For AU Mic's edge-on disk, out-of-plane surface brightness asymmetries at > 5 AU may implicate one or more planetary perturbers. Time resolved images of the MP Mus proto-planetary disk provide spatially resolved temporal variability in the disk illumination. These and other new images from our program enable direct inter-comparison of the architectures of these exoplanetary debris systems in the context of our own Solar System.Comment: 109 pages, 43 figures, accepted for publication in the Astronomical Journa

    Assessing the effects of chemical mixtures using a Bayesian network-relative risk model (BN-RRM) integrating adverse outcome pathways (AOPs) in three Puget Sound watersheds

    Get PDF
    Chemical mixtures are difficult to assess at the individual level, but more challenging at the population level. There is still little insight of the molecular pathway for numerous chemical mixtures. We have conducted a regional-scale ecological risk assessment by evaluating the effects chemical mixtures to populations with a Bayesian Network- Relative Risk Model (BN-RRM) incorporating a molecular pathway. We used this BN-RRM framework in a case study with organophosphate pesticide (OP) mixtures (diazinon, chlorpyrifos, and malathion) in three watersheds (Lower Skagit, Nooksack, Cedar) in the state of Washington (USA). Puget Sound Chinook salmon (Oncorhynchus tshawytscha) Evolutionary Significant Units (ESU) were chosen as population endpoints. These populations are a valuable ecosystem service in the Pacific Northwest because they benefit the region as a species that provide protection of biodiversity and are spiritually and culturally treasured by the local tribes. Laetz et al. (2009, 2013) indicated that organophosphate pesticide mixtures act synergistically to salmon and impair neurological molecular activity which leads to a change in swimming behavior and mortality, which then leads to changes in population productivity. Exposure response curves were generated for OP mixtures to connect the molecular pathway. Ecological stressors from dissolved oxygen and temperature were also included in our risk analysis. Synergism within the mixtures as well as increasing temperature and decreasing dissolve oxygen content lead to increasing risk to Puget Sound Chinook salmon populations. This research demonstrates a probabilistic approach with a multiple stressor framework to estimate the effects of mixtures through a molecular pathway and predict impacts to these valuable ecosystem services
    corecore