37200 research outputs found
Sort by
Patagonia\u27s Late Holocene Lake Sediments Reveal No Major Black Carbon Sources for Antarctica
Get PDFBlack carbon from biomass and fossil fuel burning is an important aerosol in the climate system. Understanding its historical variation is crucial to constrain current anthropogenic and wildfire impacts on the atmosphere. Patagonia was proposed previously as a major source region for the late 13th century black carbon increase observed in an ice core from the northern Antarctic Peninsula but not in continental Antarctic ice cores. Here, we reconstruct regional black carbon trends using high-resolution measurements of refractory black carbon (rBC) in two Patagonian lake-sediment cores spanning the last two millennia and compare the results with other records of fire activity in the region. Our new rBC reconstruction, which is consistent with macroscopic charcoal data from the same sites as well as regional charcoal data, indicates low fire activity in this region of Patagonia over the past 2000 years, with no major, long-lasting and systematic increase from the 13th century onwards that goes significantly beyond values detected earlier in these records. The consistently low rBC deposition at these sites suggests that Patagonian emissions did not contribute to the observed late 13th century rBC increases in ice cores from the Antarctic Peninsula. Moreover, the low amounts of rBC deposition throughout the Industrial Period suggests that Patagonian rBC records primarily reflect emissions from regional biomass burning and not fossil fuel combustion
Financial Metrics as Predictors of Financial Vulnerability and Nonprofit Failure
Get PDFStudying nonprofit\u27s risk factors for financial vulnerability and possible demise is important because of the negative social consequences for both the failed organization and its stockholders. Financial vulnerability is a concern shared by all nonprofit\u27s stakeholders as poor financial health affects nonprofit\u27s ability to fulfill its mission, sustain its operations, and in many cases may result in a nonprofit demise. Advance knowledge on financial vulnerability has significant implications for nonprofit\u27s leaders to develop corrective strategies to prevent failure.
Nonprofit scholars such as Tuckman and Chang, Greenlee, Hager, and Searing have contributed notable benchmarks in the field of nonprofit vulnerability, by searching for associations between wide-ranging metrics and \u27financial vulnerability\u27 as defined by the individual researcher. Only a few studies examined the association between financial metrics and the ultimate consequence of financial vulnerability - a nonprofit actual failure. This thesis aims to add to that knowledge by examining financial metrics and their association with failed or on-going nonprofits. It also examines which metrics, when combined in a statistical model, can predict future financial vulnerability which is useful information for nonprofit stakeholders when making funding and operational decisions. This study confirms that revenues, overhead ratio, and the ratio between Program Service Expense and Fund Surplus are associated with nonprofit failure, and that these metrics can be used to predict which nonprofits are financially vulnerable and susceptible to failure within the next 12 months. This knowledge may help reduce the hazard of funding a destined-to-fail nonprofit, increase funding to strengthen vulnerable nonprofits that are the sole providers of goods and services in a community, and put nonprofit management on notice so they can take corrective actions
Culturable Microbial Communities in Root Nodules of Red Alder (\u3ci\u3eAlnus rubra\u3c/i\u3e Bong.) and Scotch Broom (\u3ci\u3eCytisus scoparius\u3c/i\u3e L.): Patterns of Diversity and Composition
Get PDFEndophytes are a hyper diverse group of bacterial or fungal organisms residing within plant tissues without causing visible symptoms of disease. While their overall diversity and ecological functions are not well-understood, some endophytes can provide a range of important benefits to their host such as enhanced growth and increased tolerance to environmental stress. Nitrogen-fixing bacteria residing within nodules--specialized structures on the roots of legumes and actinorhizal plants--play an integral role in the plant microbiome by facilitating nitrogen availability in nutrient-poor environments. Remarkably, the patterns of diversity including both bacterial and fungal endophytes in root nodules are virtually known, except in a few agricultural crop legumes. This study represents the first comparison of the culturable microbial communities associated with the root nodules of red alder (Alnus rubra Bong.), an actinorhizal plant native to the Pacific Northwest of the United States, and Scotch broom (Cytisus scoparius L.), an invasive legume, which often co-occur in similar environments. Red alder and Scotch broom root nodules collected at a sympatric location near Sandy, OR, revealed high numbers of cultivable endophytes. Culturable bacterial endophytes were detected in 98% (n = 44) of red alder nodules and 93% (n = 42) of Scotch broom nodules. Out of the 306 bacterial sequences obtained from red alder and Scotch broom root nodules, a total of 88 operational taxonomic units (OTUs) were identified, with 58% (n = 51) unique to red alder, 25% (n = 22) unique to Scotch broom, and 17% (n = 15) shared between the two host species. Red alder hosted 30 bacterial genera, while Scotch broom hosted 20 genera, with red alder exhibiting significantly greater bacterial diversity than Scotch broom (PERMANOVA: p = 0.001, R² = 0.1158). Although red alder hosted a more diverse root nodule microbial community, both hosts displayed a high frequency of Bradyrhizobium and Mesorhizobium within their root nodules. While typically associated with legumes, these genera have previously been isolated from alder and shown to enhance its growth. However, this is the first time rhizobia have been reported as the most frequently observed bacterial taxa in red alder root nodules. Fungal endophytes were less prevalent, found in 53% (n = 24) of red alder nodules and 56% (n = 25) of Scotch broom nodules. Out of the 147 fungal sequences obtained from red alder and Scotch broom root nodules, a total of 51 operational taxonomic units (OTUs) were identified, with 55% (n = 28) unique to red alder, 29% (n = 15) unique to Scotch broom, and 16% (n = 8) shared between the two host species. Red alder hosted six fungal orders, while Scotch broom hosted seven, with Eurotiales--driven by the prevalence of Penicillium--being the dominant order in both hosts. Despite red alder exhibiting slightly higher fungal diversity, the fungal communities were not significantly different between the two hosts (PERMANOVA: p = 0.224, R² = 0.0802). This contrasts with previous studies that reported significant variation in fungal root nodule endophytes between legumes and non-legumes and even among sympatric alder species. Red alder exhibited a higher frequency of microbial co-occurrence within its root nodules, with 96% (n = 43) of nodules containing multiple microbes compared to 73% (n = 33) in Scotch broom. This may suggest that red alder nodules are not only more diverse but also provide a more hospitable environment for microbial endophytes to coexist, potentially fostering synergistic interactions. Overall, the results revealed distinct patterns of bacterial diversity and composition within root nodules, significantly influenced by host type, with red alder hosting a more diverse bacterial community than Scotch broom. Although red alder and Scotch broom are fundamentally different plants, they often co-occur in similar environments and can alter soil nitrogen levels through associations with nitrogen-fixing bacteria. This study serves as a foundational step towards understanding host-specific plant-microbe interactions happening belowground, with significant implications for ecosystem recovery, land management, and the role of plant-microbe interactions in plant invasions
Oregon’s Journey Creating Social and Emotional Learning Standards for Educator Preparation Programs
Get PDFThis paper summarizes Oregon’s creation and implementation of Standards in Social and Emotional Learning (SEL) for Educator Preparation programs (EPPs) in response to the House Bill 2166 passed in 2021. Initial steps included gaining an understanding of current practices and new teachers’ perspectives on preparation they received in SEL. The Educator Preparation SEL Survey revealed that EPP courses largely emphasized the Learning Context and Student SEL, but not Teacher SEL in their programming. Findings from the New Teacher SEL Survey indicated that while many new teachers felt prepared to create inclusive and positive learning environments, half felt unprepared to deliver SEL-based instruction and did not feel equipped by their programs with personal SEL skills to manage the stressors of teaching. Results from these surveys highlight the need to integrate SEL into educator preparation to develop educators who can create supportive and inclusive learning environments. An interdisciplinary workgroup utilized findings from these surveys to develop SEL standards for EPPs. The workgroup adopted the Anchor Competency Framework by Markowitz and Bouffard (2020) and aligned it with CASEL’s five SEL competencies to create comprehensive standards for EPPs. These standards were reviewed and adopted in Spring 2023 and implementation strategies are underway in Oregon. The Oregon experience highlights the necessity of systemic approaches to embedding SEL in teacher education to enhance the well-being and effectiveness of future teachers. Oregon’s process detailed here serves as an example and inspiration for states aiming to infuse SEL into their teacher preparation programs
Poa Annua Ecology, Biology, and Integrated Weed Management Practices in Turfgrass
Get PDFPoa annua L. is one of the most widespread and troublesome weeds of turfgrass. It persists as both an annual and perennial and is adaptable to almost any static maintenance regime, including adaptation to mowing heights and evolution of herbicide resistance. This management guide is intended to provide stakeholders with a summary of new and existing knowledge on integrated Poa annua management. Here we review the basic biology and ecology, as well as practical integrated weed management (IWM) strategies developed for its control
Effects of Wetting Events on Mass Timber Surface Microbial Communities and VOC Emissions: Implications for Building Operation and Occupant Well-Being
Get PDFIntroductionHumans have used wood as a construction material throughout history. Currently, mass timber products, such as cross-laminated timber (CLT), are becoming more popular as a structural material, since they are renewable and have a lower carbon footprint than concrete or steel. Nonetheless, some building types, such as healthcare, veterinary, and food manufacturing, avoid using structural mass timber due to concerns about microbial growth in the event of wetting. One solution is to use protective coatings on mass timber products to increase moisture resistance, although the coatings themselves may generate concerns about volatile organic compound (VOC) emissions. Natural uncoated wood also produces VOCs, some of which may have intrinsic antimicrobial effects.MethodsIn this study, we inoculated coated and uncoated cross- laminated timber (CLT) blocks with a mock microbial community and isolated each block within individual sealed microcosms. We characterized VOCs and surface microbial communities from the CLT blocks before, during, and after wetting periods of varying durations. VOC concentration and emission rate were analyzed with chromatography-mass spectrometry (GC-MS), while microbial community abundance, diversity, and composition were analyzed through qPCR and shotgun metagenomics.ResultsVOC emissions were elevated immediately after inoculation, then decreased through the remainder of the experiment, except for a plateau during the wetting period. VOCs from uncoated CLT blocks were primarily terpenes, while coated blocks emitted VOCs associated with coatings, plastics, and industrial solvents, as well as terpenes. One VOC—acetoin (3-hydroxy, 2-butanone)—was present at high levels across all samples immediately after microbial inoculation. Bacteria comprised 99.54% of the identified microbial sequences. The plastic control microcosm (not containing a CLT block) had higher abundance of viable bacteria for the majority of the study, but there was no difference in abundance between coated and uncoated blocks. Prior to wetting periods, microbial composition was driven primarily by sampling day, whereas surface type played a larger role during and after wetting periods
A Meta-Analysis of Accent Bias in Employee Interviews: the Effects of Gender and Accent Stereotypes, Interview Modality, and Other Moderating Features
Get PDFTo address concerns of subtle discrimination against stigmatized groups, we meta‐analyze the magnitude and moderators of bias against non‐standard accents in employment interview evaluations. Results from a multi‐level random‐effects meta‐analysis (unique effects: k = 41, N = 7,596; multi‐level effects accounting for dependencies: k = 120, N = 20,873) demonstrate that standard‐accented (SA) interviewees are consistently favored over non‐standard‐accented (NSA) interviewees (d = 0.46). Accent bias is stronger against women compared to men, particularly when evaluator samples are predominantly female, and was strongly predicted by interviewers\u27 stereotypes of NSA interviewees as less competent and, to a lesser extent, as less warm. Accent bias was not significantly impacted by perceptions of comprehensibility, accentedness, accent type, interview modality, study rigor, or job speaking skill requirements
Photocathodes from Aerobic Oxidation of Tellurorhodamines
Get PDFGrowing environmental concerns have facilitated an increased need for renewable energy. Solar energy is an excellent source of renewable energy, however current dye-sensitized solar cells are not efficient enough for commercial use. This thesis attempts to create a novel dye-sensitized cathode to increase the efficiency of dye-sensitized solar cells.
Dye-sensitized cathodes could lower the energy level on the cathode and thereby increase the overall efficiency of the solar cell, however until now it has not been attempted. A tellurorhodamine dye with a mesityl ring was chosen as the dye for its ability to aerobically oxidize in the presence of light. The ability of the dye to undergo photo-oxidation and how its absorbance was affected were analyzed to measure the tellurorhodamine dye\u27s ability to absorb solar light. The electrochemical properties of the dye were then analyzed to quantify how the dye underwent reduction via a current. Finally, the tellurorhodamine\u27s photo-electrochemical properties were analyzed by measuring the voltage response under varying light and dark conditions.
The dye was found to experience red-shifted absorption after aerobic oxidation. The electrochemical response of the dye to light was to produce increasing voltage, consistent with the oxidized concentration of the dye increasing. Increasing the available light caused a greater increase in the voltage response while illuminated. The tellurorhodamine dye required a current to be reduced, and a steady applied current caused a consistent decrease in voltage under dark conditions. Taken together these results show a complete redox cycle of the chosen tellurorhodamine dye and offer potential for a self-sensitizing cathode
Disaster Vulnerability Hotspots in the Portland Metro-Region: Converging Indices for Equitable Resilience
Get PDFAs climate-related extreme events intensify across the globe, governments, practitioners, and communities have focused on reducing vulnerability and building resilience. However, debates persist about the validity, differences, and similarities between social vulnerability and resilience indices. This study combines the Social Vulnerability Index (SoVI) (26 indicators) and the Baseline Resilience Indicators for Communities (BRIC) (52 indicators) to assess the Portland Metro region using ACS (2016–2020) and 2020 Census data. Through hotspot analysis, Pearson’s correlation, and linear regression, we identify key drivers as well as areas of convergence and divergence between the two indices. Results show a strong overlap between SoVI and BRIC, with distinct drivers across counties and census tracts. High SoVI/low BRIC hotspots were found in Clackamas and Multnomah counties. In Clackamas, vulnerability was due to limited hospital access, weak infrastructure and institutions, mobile homes, and inadequate community resources. In Multnomah, poverty, low educational attainment, and single-parent households were the primary drivers of vulnerability. While Clackamas had stronger environmental resilience, Multnomah showed higher resilience than Washington County due to better transportation, institutions, and community capital. Having a high proportion of migrant populations, institutionalized residents, and mobile homes reduced resilience in Washington County. These findings support the combined use of SoVI-BRIC indices for targeted resilience planning and equitable resource allocation for infrastructure development, environmental protection, social programs, and emergency preparedness across multiple scales
Glacial-Interglacial and Millennial-Scale Changes in Nitrous Oxide Emissions Pathways and Source Regions
Get PDFDuring the transition from the Last Glacial Maximum (LGM) to the Holocene, the atmospheric N2O mole fraction increased by 80 nmol mol−1. Using ice core measurements of N2O isotopomer ratios, we show that this increase was driven by increases in both nitrification and denitrification, with the relative partitioning between both production pathways depending on the assumed isotopic end‐member source signatures. Similarly, we also attribute a 35 nmol mol−1 N2O mole fraction increase during the Heinrich Stadial 4/Dansgaard Oeschger 8 (HS4/DO8) millennial‐scale event to increases in both N2O production pathways. In contrast, the 25 nmol mol−1 N2O mole fraction decrease during the Younger Dryas was driven almost exclusively by a decrease in nitrification. The deglacial and HS4/DO8 increases in N2O production occurred in both marine and terrestrial environments, with the terrestrial source responding faster to warming by about two centuries. Constraints on changes in nitrification and denitrification emissions are robust and consistent with previous studies showing the sensitivity of N2O emissions to abrupt Northern Hemisphere warming. This study demonstrates for the first time the importance of both denitrification and nitrification pathways in driving source changes. Absolute emissions are more uncertain due to uncertainty about source isotopomer signatures. For instance, the contribution of denitrification to emissions at the LGM shifts from (65 ± 10) % to (91 ± 6) % when factoring in isotope enrichment due to partial reduction of N2O to N2 during denitrification. Reducing uncertainty in source signatures will increase the power of ice core N2O isotope records in deducing environmental change