1,527 research outputs found
Using Stable Isotopes to Determine Dominant Methane Production Pathways of Thaw Ponds in a Subarctic Peatland
Arctic and subarctic ecosystems are currently warming faster than any other region of the globe, accelerating seasonal permafrost thaw. As thaw progresses, small water bodies can form due to slumping of the peatland surface. These ponds emit methane (CH4), a strong, radiatively important trace gas, predominantly through ebullition (bubbling). Two different types of methanogenic Archaea present in these systems produce CH4 through their respective production pathways: acetoclastic and hydrogenotrophic methanogenesis. The acetoclastic pathway forms CH4 using CH3COOH, an organic carbon (C) source while hydrogenotrophic methanogenesis uses CO2, an inorganic C source. Stable isotopes can be used to characterize the relative contribution of these two pathways in overall CH4 production and to better constrain the global CH4 budget and improve modeling of future emission scenarios. We used stable isotopes, carbon-13 (13C) of CH4 and CO2, deuterium (D) of CH4, and calculated apparent fractionation factors to determine the relative contribution of acetoclastic versus hydrogenotrophic pathways of methanogenesis in thaw ponds in a subarctic peatland located in the discontinuous permafrost region of northern Sweden. Isotopic analysis was performed on porewater samples (n = 310) and gas captured from ebullition (n = 177). Samples were collected from nine ponds over seven years (2012 to 2019) during the ice-free months (June to September). We tested important physical attributes of the ponds that were related to their formation and CH4 production pathways. Results indicated that δ13C-CH4 of ebullition (-86.3‰ to -49.2‰) and porewater (98.2‰ to -42.9‰) and the inferred contribution of hydrogenotrophic vs. acetoclastic methanogenesis differed significantly between certain ponds and pond types. Over the course of this study dissolved and ebullitive δ13C-CH4 remained relatively constant between years but varied significantly between months. Alternatively, δD-CH4 of ebullition (-397.0‰ to -199.4‰) and porewater (-383.4‰ to -184.8‰) did not differ between sampling years or months. Pond types that are partially thawed and have a lower daily CH4 ebullitive flux appear to have a higher relative contribution of hydrogenotrophic methanogenesis while types that are partially or fully thawed and have a higher daily CH4 ebullitive flux appear to have a higher contribution of acetoclastic methanogenesis relative to other pond types. Differences in CH4 isotopic composition between pond types indicates that shifts in isotopic emissions could occur as thaw progresses in northern permafrost ecosystems. While we did observe expansion of ponds and landscape slumping at Stordalen Mire over our 7-year study, a strong trend in isotope signal was not observed likely due to the high interannual variability. This unique multi-year study characterized δ13C-CH4 and δD-CH4 values for ebullition and porewater from open-water thaw ponds providing valuable data to constrain the global CH4 budget and improve modeling of the contribution of these systems to emissions now and in the future
HealthTech: How Blockchain Can Simplify Healthcare Compliance
This Note broadly explores solutions to modern-day accessibility and security problems latent in electronic health records. Specifically, this Note discusses HIPAA and HITECH, the current law in place, and how blockchain technology can be used to fix the accessibility and security problems of current electronic health records. This Note proposes that blockchain technology can help a healthcare industry struggling to adhere to the current rule of law in an era of Big Data. Further, Blockchain technology can help individual consumers, particularly those with significant health issues, obtain the best possible medical care while simultaneously keeping their private and sensitive information safe. This innovative technology offers the security and sophistication needed to usher healthcare providers and healthcare consumers into a new technological era fraught with privacy issues
2010 New York State Reference Manual for Regional Schools, Income Tax Management and Reporting for Small Businesses and Farms
E.B. 2010-1
Preserving the village : Cambridge Street and the end of rent control
Thesis (M.C.P.)--Massachusetts Institute of Technology, Dept. of Urban Studies and Planning, 1995.Includes bibliographical references (p. 102-103).by Kathryn Bennett.M.C.P
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Public Performance Metrics: Driving Physician Motivation and Performance
Introduction: As providers transition from “fee-for-service” to “pay-for-performance” models, focus has shifted to improving performance. This trend extends to the emergency department (ED) where visits continue to increase across the United States. Our objective was to determine whether displaying public performance metrics of physician triage data could drive intangible motivators and improve triage performance in the ED.Methods: This is a single institution, time-series performance study on a physician-in-triage system. Individual physician baseline metrics—number of patients triaged and dispositioned per shift—were obtained and prominently displayed with identifiable labels during each quarterly physician group meeting. Physicians were informed that metrics would be collected and displayed quarterly and that there would be no bonuses, punishments, or required training; physicians were essentially free to do as they wished. It was made explicit that the goal was to increase the number triaged, and while the number dispositioned would also be displayed, it would not be a focus, thereby acting as this study’s control. At the end of one year, we analyzed metrics.Results: The group’s average number of patients triaged per shift were as follows: Q1-29.2; Q2-31.9; Q3-34.4; Q4-36.5 (Q1 vs Q4, p < 0.00001). The average numbers of patients dispositioned per shift were Q1-16.4; Q2-17.8; Q3-16.9; Q4-15.3 (Q1 vs Q4, p = 0.14). The top 25% of Q1 performers increased their average numbers triaged from Q1-36.5 to Q4-40.3 (ie, a statistically insignificant increase of 3.8 patients per shift [p = 0.07]). The bottom 25% of Q1 performers, on the other hand, increased their averages from Q1-22.4 to Q4-34.5 (ie, a statistically significant increase of 12.2 patients per shift [p = 0.0013]).Conclusion: Public performance metrics can drive intangible motivators (eg, purpose, mastery, and peer pressure), which can be an effective, low-cost strategy to improve individual performance, achieve institutional goals, and thrive in the pay-for-performance era
Thinking fan's rock band : R.E.M. fandom and negotiations of normativity in Murmurs.com
This thesis analyses how normative behaviour is negotiated within Murmurs, an online community for fans of rock band R.E.M. Undertaken as a cyber-ethnography, I examine the manner in which normative identity is constructed in Murmurs through masculinised Liberal intelligentsia "central values" of the R.E.M. fan's subcultural homology, such as tolerance, good will and equality, the rejection of which works to define the Other in the community. I demonstrate how the object of fandom as the "thinking fan's rock band" works to reflect and reinforce these "central values" and the processes through which they are explicitly enforced by the community hierarchy through strategies of power. My findings therefore show that normative behaviour in Murmurs is not a given, but requires continuous maintenance and governance. In conjunction with compliance to the homologous values, I identify in Murmurs how normativity can be achieved by strict adherence to four other key practices: reading in the "right way," assuming the correct gendered discourse, participating in the exchange of knowledge with other fans and maintaining a focus on the object of fandom. To analyse the processes of negotiation further, and in an effort to redress the inadequacies in the field of literature surrounding online communities and fan cultural norms regarding oppositional intra-communal fan identities, I examine through case studies the activities of three non-normative groups within Murmurs (Trobes, Droolers and Pointless Posters), determining how the community negotiates different types of fan behaviour that are seemingly a threat to normative conduct. However, quite notably, my analysis is conducted from a unique "insider" position in that, in addition to being an ethnographic researcher in the virtual field, I am both an R.E.M. fan and member of Murmurs' subcultural police, an official role which involves my active participation in the enforcement and governance of this non-normative Other in Murmurs. By doing this, I challenge the assumed existence of a consistently singular, or cohesive, identity in an online fan community. My conclusion in the thesis therefore rests upon a recommendation that future studies in this field should move away from assumptions of singularity and instead attempt to understand oppositional fan identities by examining the power relations surrounding them, and the processes through which fans negotiate normative identity within a community.EThOS - Electronic Theses Online ServiceGBUnited Kingdo
The endocytosis gene END3 is essential for the glucose-induced rapid decline of small vesicles in the extracellular fraction in Saccharomyces cerevisiae
Background: Protein secretion is a fundamental process in all living cells. Gluconeogenic enzymes are secreted when Saccharomyces cerevisiae are grown in media containing low glucose. However, when cells are transferred to media containing high glucose, they are internalized. We investigated whether or not gluconeogenic enzymes were associated with extracellular vesicles in glucose-starved cells. We also examined the role that the endocytosis gene END3 plays in the internalization of extracellular proteins/vesicles in response to glucose addition. Methods: Transmission electron microscopy was performed to determine the presence of extracellular vesicles in glucose-starved wild-type cells and the dynamics of vesicle transport in cells lacking the END3 gene. Proteomics was used to identify extracellular proteins that associated with these vesicles. Results: Total extracts prepared from glucose-starved cells consisted of about 95% small vesicles (30–50 nm) and 5% large structures (100–300 nm). The addition of glucose caused a rapid decline in small extracellular vesicles in wild-type cells. However, most of the extracellular vesicles were still observed in cells lacking the END3 gene following glucose replenishment. Proteomics was used to identify 72 extracellular proteins that may be associated with these vesicles. Gluconeogenic enzymes fructose-1,6-bisphosphatase, malate dehydrogenase, isocitrate lyase, and phosphoenolpyruvate carboxykinase, as well as non-gluconeogenic enzymes glyceraldehyde-3-phosphate dehydrogenase and cyclophilin A, were distributed in the vesicle-enriched fraction in total extracts prepared from cells grown in low glucose. Distribution of these proteins in the vesicle-enriched fraction required the integrity of the membranes. When glucose was added to glucose-starved wild-type cells, levels of extracellular fructose-1,6-bisphosphatase, malate dehydrogenase, isocitrate lyase, phosphoenolpyruvate carboxykinase, glyceraldehyde-3-phosphate dehydrogenase, and cyclophilin A were reduced. In contrast, in cells lacking the END3 gene, levels of these proteins in the extracellular fraction remained high. Conclusion: The END3 gene is required for the rapid decline of extracellular proteins and vesicles in response to glucose addition
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