141 research outputs found

    Improving student learning in higher education: A mixed methods study

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    To improve quality, higher education must be able to demonstrate learning improvement. To do so, academic degree program leaders must assess learning, intervene, and then re-assess to determine if the intervention was indeed an improvement (Fulcher, Good, Coleman, and Smith, 2014). This seemingly “simple model” is rarely enacted in higher education (Blaich & Wise, 2011). The purpose of this embedded mixed methods study was to investigate the effectiveness and experience of a faculty development program focused on a specific programmatic learning outcome. Specifically, the intervention was intended to increase students’ ethical reasoning skills aligned with a university-wide program. The results suggested that this experience did indeed improve student’s ethical reasoning skills. Likewise, the experience was positive for faculty participants. This study provides evidence supporting the connection of assessment and faculty development to improve student learning

    Sub-lethal Effects of Heavy Metal Pollution on Intertidal Crustaceans in the Duwamish Waterway

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    Throughout its history there has been heavy industrial pollution along the Duwamish Waterway in Seattle, Washington. Industrial and urban activities such as dredging, runoff, and aqueous waste production can have damaging effects on marine organisms, as the deposited contaminants, such as heavy metals, accumulate in sediment. Despite the well-documented history of lead contamination in the Duwamish Waterway, the effect of such contamination on aquatic organisms has scarcely been studied. This paper investigates the impact of sediment contaminants on the benthos by examining commonly found invertebrates in Seattle, Washington. The benthos is defined as the flora and fauna living on and in the bottom of sediments of a body of water. We examined the lethal and sub-lethal effects of lead contamination on three benthic crustaceans (Idotea wosnesenskii, Gnorimosphaeroma oregonensis, and Hemigrapsus oregonensis) along two sites on the Duwamish Waterway of known high contaminant levels. We then compared these sites to two other sites having known low contaminant levels. Despite significant differences in lead and copper sediment contamination, there were few measurable effects of heavy metal contamination among populations of I. wosnesenskii and G. oregonensis. Higher proportions of brooding females at non-contaminated sites, significantly different only in the month of June, could suggest disturbance resistance in H. oregonensis. We also examined food preference of Fucus as a food source of isopods at the four sites. Isopods from contaminated sites appeared to have a stronger preference for contaminated Fucus, but after statistical analysis they did not differ significantly from the preferences of the isopods collected at the uncontaminated site. With this in mind, we urge a long-term environmental assessment examining sediment contamination in the Duwamish Waterway to learn how anthropogenic stressors in aquatic environments alter ecosystems for benthic organisms

    Timing of snowmelt affects species composition via plant strategy filtering

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    Plant strategy schemes aim to classify plants according to measurable traits and group species according to their shared evolutionary responses to selective pressures. In this way, it becomes possible to make meaningful comparisons among ecosystems and communities and to predict how plant communities might respond to changes in their environment. Here, we classified common alpine plants which occur in snowpatches (Early and Late snowmelt sites) and in adjacent vegetation (Snow-free sites which melt early in the growing season) using Grime's CSR plant strategy scheme. Alpine plant communities are largely driven by environmental filters associated with a relatively constant gradient of snowmelt timing. Since snow persistence influences the abiotic environment and plant assemblages alike, we hypothesised that these patterns would be reflected in community CSR scores. Weighted community CSR scores were clustered towards the stress-tolerator (S) corner of the triangular CSR space, and Snow-free communities were significantly more stress-tolerant than Early and Late snowmelt communities. This suggests that snowpatch communities are functionally distinct from surrounding vegetation when considering the major axes of plant variation identified by CSR theory. These results lend further support to the importance of the timing of snowmelt as a key filter, influencing how species and plant strategy types distribute themselves across the alpine landscape

    Soil reconstruction after mining fails to restore soil function in an Australian arid woodland

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    The biogeochemical properties of soils drive ecosystem function and vegetation dynamics, and hence soil restoration after mining should aim to reinstate the soil properties and hydrological dynamics of remnant ecosystems. The aim of this study is to assess soil structure in two vegetation types in an arid ecosystem, and to understand how these soil properties compare to a reconstructed soil profile after mining. In an arid ecosystem in southeast Australia, soil samples were collected at five depths (to 105 cm) from remnant woodland and shrubland sites, and sites either disturbed or totally reconstructed after mining. We assessed soil physico-chemical properties and microbial activity. Soils in the remnant arid ecosystem had coarse-textured topsoils that overlay clay horizons, which allows water to infiltrate and avoid evaporation, but also slows drainage to deeper horizons. Conversely, reconstructed soils had high sand content at subsoil horizons and high bulk density and compaction at surface layers (0–20 cm). Reconstructed soils had topsoils with higher pH and electrical conductivity. The reconstructed soils did not show increased microbial activity with time since restoration. Overall, the reconstructed soil horizons were not organized in a way that allowed rainfall infiltration and water storage, as is imperative to arid-zone ecosystem function. Future restoration efforts in arid ecosystems should focus on increasing sand content of soils near the surface, to reduce evaporative water loss and improve soil quality and plant health. © 2020 Society for Ecological Restoratio

    Improving Distances to Binary Millisecond Pulsars with Gaia

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    Pulsar distances are notoriously difficult to measure, and play an important role in many fundamental physics experiments, such as pulsar timing arrays (PTAs). Here we perform a cross-match between International PTA pulsars (IPTA) and Gaia's DR2 and DR3. We then combine the IPTA pulsar's parallax with its binary companion's parallax, found in Gaia, to improve the distance measurement to the binary. We find 7 cross-matched IPTA pulsars in Gaia DR2, and when using Gaia DR3, we find 6 IPTA pulsar cross-matches, but with 7 Gaia objects. Moving from Gaia DR2 to Gaia DR3, we find that the Gaia parallaxes for the successfully cross-matched pulsars improved by 53%53\%, and pulsar distances improved by 29%29\%. Finally, we find that binary companions with a <3.0σ<3.0\sigma detection are unreliable associations, setting a high bar for successful cross-matches.Comment: 9 pages, 8 figures, 4 table

    Assessing Peracetic Acid Application Methodology and Impacts on Fluidized Sand Biofilter Performance

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    Nitrifying biofilters oxidize harmful ammonia excreted by fish into less toxic nitrate within recirculating aquaculture systems (RAS). Biofilter performance and resulting RAS water quality largely depend on a robust microbiome that effectively converts nitrogenous wastes; however, occasional use of water disinfectants may also be necessary to reduce or eliminate specific fish pathogens. Disinfectants and sanitizers such as peracetic acid (PAA) work by disrupting microbial activity and could unintentionally alter the microbially-driven nitrification biofiltration process if allowed to circulate within an RAS. Furthermore, the target concentration and application method of PAA may influence the level of biofilter disruption. For this study, 12 replicated experimental-scale fluidized sand biofilters were dosed with PAA to achieve target concentrations ranging from 1.0-–2.5 mg/L, a typical low-dose treatment range to reduce or eliminate opportunistic pathogens. Two application methods were compared, including (i) a single pulse of PAA added every other day for five days, and (ii) smaller doses of PAA added every five minutes over four hours. The PAA decay was monitored and predosing and postdosing water quality parameters were assessed. Regardless of the target concentration or application method, PAA addition within the tested range did not cause significant disruption to the biofilters’ nitrification processes. This research demonstrates that PAA may be a viable water sanitizer for the RAS industry, although further research to refine safe application protocols is necessary.Assessing Peracetic Acid Application Methodology and Impacts on Fluidized Sand Biofilter PerformancepublishedVersio

    Exposure to Household Air Pollution from Biomass Cookstoves and Blood Pressure Among Women in Rural Honduras: A Cross‐Sectional Study

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    Growing evidence links household air pollution exposure from biomass cookstoves with elevated blood pressure. We assessed cross‐sectional associations of 24‐hour mean concentrations of personal and kitchen fine particulate matter (PM2.5), black carbon (BC), and stove type with blood pressure, adjusting for confounders, among 147 women using traditional or cleaner‐burning Justa stoves in Honduras. We investigated effect modification by age and body mass index. Traditional stove users had mean (standard deviation) personal and kitchen 24‐hour PM2.5 concentrations of 126 ÎŒg/m3 (77) and 360 ÎŒg/m3 (374), while Justa stove users’ exposures were 66 ÎŒg/m3 (38) and 137 ÎŒg/m3(194), respectively. BC concentrations were similarly lower among Justa stove users. Adjusted mean systolic blood pressure was 2.5 mm Hg higher (95% CI, 0.7‐4.3) per unit increase in natural log‐transformed kitchen PM2.5 concentration; results were stronger among women of 40 years or older (5.2 mm Hg increase, 95% CI, 2.3‐8.1). Adjusted odds of borderline high and high blood pressure (categorized) were also elevated (odds ratio = 1.5, 95% CI, 1.0‐2.3). Some results included null values and are suggestive. Results suggest that reduced household air pollution, even when concentrations exceed air quality guidelines, may help lower cardiovascular disease risk, particularly among older subgroups

    Exposure to Household Air Pollution from Biomass-Burning Cookstoves and HbA1c and Diabetic Status Among Honduran Women

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    Household air pollution from biomass cookstoves is estimated to be responsible for more than two and a half million premature deaths annually, primarily in low and middle‐income countries where cardiometabolic disorders, such as Type II Diabetes, are increasing. Growing evidence supports a link between ambient air pollution and diabetes, but evidence for household air pollution is limited. This cross‐sectional study of 142 women (72 with traditional stoves and 70 with cleaner‐burning Justa stoves) in rural Honduras evaluated the association of exposure to household air pollution (stove type, 24‐hour average kitchen and personal fine particulate matter [PM2.5] mass and black carbon) with glycated hemoglobin (HbA1c) levels and diabetic status based on HbA1c levels. The prevalence ratio (PR) per interquartile range increase in pollution concentration indicated higher prevalence of prediabetes/diabetes (vs normal HbA1c) for all pollutant measures (eg, PR per 84 ÎŒg/m3 increase in personal PM2.5, 1.49; 95% confidence interval [CI], 1.11‐2.01). Results for HbA1c as a continuous variable were generally in the hypothesized direction. These results provide some evidence linking household air pollution with the prevalence of prediabetes/diabetes, and, if confirmed, suggest that the global public health impact of household air pollution may be broader than currently estimated

    Study Protocol for a Stepped-Wedge Randomized Cookstove Intervention in Rural Honduras: Household Air Pollution and Cardiometabolic Health

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    Growing evidence links household air pollution exposure from biomass-burning cookstoves to cardiometabolic disease risk. Few randomized controlled interventions of cookstoves (biomass or otherwise) have quantitatively characterized changes in exposure and indicators of cardiometabolic health, a growing and understudied burden in low- and middle-income countries (LMICs). Ideally, the solution is to transition households to clean cooking, such as with electric or liquefied petroleum gas stoves; however, those unable to afford or to access these options will continue to burn biomass for the foreseeable future. Wood-burning cookstove designs such as the Justa (incorporating an engineered combustion zone and chimney) have the potential to substantially reduce air pollution exposures. Previous cookstove intervention studies have been limited by stove types that did not substantially reduce exposures and/or by low cookstove adoption and sustained use, and few studies have incorporated community-engaged approaches to enhance the intervention

    Exposure to Household Air Pollution from Biomass Cookstoves and Levels of Fractional Exhaled Nitric Oxide (FeNO) among Honduran Women

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    Household air pollution is estimated to be responsible for nearly three million premature deaths annually. Measuring fractional exhaled nitric oxide (FeNO) may improve the limited understanding of the association of household air pollution and airway inflammation. We evaluated the cross-sectional association of FeNO with exposure to household air pollution (24-h average kitchen and personal fine particulate matter and black carbon; stove type) among 139 women in rural Honduras using traditional stoves or cleaner-burning Justastoves. We additionally evaluated interaction by age. Results were generally consistent with a null association; we did not observe a consistent pattern for interaction by age. Evidence from ambient and household air pollution regarding FeNO is inconsistent, and may be attributable to differing study populations, exposures, and FeNO measurement procedures (e.g., the flow rate used to measure FeNO)
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