4,933 research outputs found
Element and nutrient mass-balances in a large semi-arid riverine lake system (the Lower Lakes, South Australia)
No full textPerran Cook, Kane T. Aldridge, Sébastien
Lamontagne, Justin D. Brookeshttp://trove.nla.gov.au/work/374699
Ambient groundwater flow diminishes nitrate processing in the hyporheic zone of streams
Get PDFModeling and experimental studies demonstrate that ambient groundwater reduces hyporheic exchange, but the implications of this observation for stream N-cycling is not yet clear. Here we utilize a simple process-based model (the Pumping and Streamline Segregation or PASS model) to evaluate N-cycling over two scales of hyporheic exchange (fluvial ripples and riffle-pool sequences), ten ambient groundwater and stream flow scenarios (five gaining and losing conditions and two stream discharges), and three biogeochemical settings (identified based on a principal component analysis of previously published measurements in streams throughout the United States). Model-data comparisons indicate that our model provides realistic estimates for direct denitrification of stream nitrate, but overpredicts nitrification and coupled nitrification-denitrification. Riffle-pool sequences are responsible for most of the N-processing, despite the fact that fluvial ripples generate 3-11 times more hyporheic exchange flux. Across all scenarios, hyporheic exchange flux and the Damköhler Number emerge as primary controls on stream N-cycling; the former regulates trafficking of nutrients and oxygen across the sediment-water interface, while the latter quantifies the relative rates of organic carbon mineralization and advective transport in streambed sediments. Vertical groundwater flux modulates both of these master variables in ways that tend to diminish stream N-cycling. Thus, anthropogenic perturbations of ambient groundwater flows (e.g., by urbanization, agricultural activities, groundwater mining, and/or climate change) may compromise some of the key ecosystem services provided by streams
Letter from J.W. Cook to Thomas Lamb Eliot
No full texthttps://rdc.reed.edu/v1/resources/5e17b7c9-4bca-4fcf-8784-0915783532dd/thumb/128.jpgIt is possible that the author is James W. Cook, who was an important figure in the establishment of the Portland Unitarian Church
Letter from J.W. Cook to Thomas Lamb Eliot
No full texthttps://rdc.reed.edu/v1/resources/c9f13811-9c93-449b-8b79-31dd26e7a981/thumb/128.jpgIt is probable that the author is James W. Cook, who was an important figure in the establishment of the Portland Unitarian Church
Letter from J.W. Cook to Thomas Lamb Eliot
No full texthttps://rdc.reed.edu/v1/resources/413865c0-390a-449d-9d4e-f69f66754b8e/thumb/128.jpgIt is possible that the author is James W. Cook, who was an important figure in the establishment of the Portland Unitarian Church
Letter from J.W. Cook to Thomas Lamb Eliot
No full texthttps://rdc.reed.edu/v1/resources/48a1abe6-3896-473b-bc17-0796ead5e587/thumb/128.jpgIt is probable that the author is James W. Cook, who was an important figure in the establishment of the Portland Unitarian Church
Factoring stream turbulence into global assessments of nitrogen pollution
Get PDFThe discharge of excess nitrogen to streams and rivers poses an existential threat to both humans and ecosystems. A seminal study of headwater streams across the United States concluded that in-stream removal of nitrate is controlled primarily by stream chemistry and biology. Reanalysis of these data reveals that stream turbulence (in particular, turbulent mass transfer across the concentration boundary layer) imposes a previously unrecognized upper limit on the rate at which nitrate is removed from streams. The upper limit closely approximates measured nitrate removal rates in streams with low concentrations of this pollutant, a discovery that should inform stream restoration designs and efforts to assess the effects of nitrogen pollution on receiving water quality and the global nitrogen cycle
Oral History Interview with Robert Cook-Deegan
No full textThis interview with Bob Cook-Deegan, MD, is part of “Moral Histories: Voices and Stories from the Founding Figures of Bioethics,” an oral history project of the Johns Hopkins Berman Institute of Bioethics. Prof. Cook-Deegan is a professor in the School for the Future of Innovation in Society and the Consortium for Science, Policy, and Outcomes at Arizona State University. He was the founding director of the Center for Genome Ethics, Law, and Policy at Duke University’s Institute for Genome Sciences and Policy. He served at the Office of Technology Assessment of the United States Congress where he contributed to major reports on emerging biomedical technologies and their societal impacts. He is the author of The Gene Wars: Science, Politics, and the Human Genome, a comprehensive account of the struggle to launch the Human Genome Project. His areas of expertise include genomics, genetic policy, Open Science, health technology, and public policy.
Bob Cook-Deegan recounts his childhood in Denver as the son of a physician. He discusses his early academic career, his undergraduate years at Harvard, his time at the University of Colorado Medical School, and his decision to pursue medical research. He also talks about becoming a father and maintaining a work-life balance with his two children and wife, Kathryn. Cook Deegan shares his experience researching Alzheimer’s disease, as well as his rotation at the National Institutes of Health. Dr. Cook-Deegan details his work at the Office of Technology Assessment (OTA), including reports on aging, biotech, and the Human Genome Project, and offers an account of its eventual demise due to political changes. Other topics include the history of the Bermuda Principles, the role of political administrations on health policy, the current turn to Open Science, and Cook-Deegan's own relationship to collecting oral histories. He concludes the conversation with a reflection on the Trump administration’s recent decision to cut funding for many science-funding agencies
Oral History Interview with Robert Cook-Deegan
No full textThis interview with Bob Cook-Deegan, MD, is part of “Moral Histories: Voices and Stories from the Founding Figures of Bioethics,” an oral history project of the Johns Hopkins Berman Institute of Bioethics. Prof. Cook-Deegan is a professor in the School for the Future of Innovation in Society and the Consortium for Science, Policy, and Outcomes at Arizona State University. He was the founding director of the Center for Genome Ethics, Law, and Policy at Duke University’s Institute for Genome Sciences and Policy. He served at the Office of Technology Assessment of the United States Congress where he contributed to major reports on emerging biomedical technologies and their societal impacts. He is the author of The Gene Wars: Science, Politics, and the Human Genome, a comprehensive account of the struggle to launch the Human Genome Project. His areas of expertise include genomics, genetic policy, Open Science, health technology, and public policy.
Bob Cook-Deegan recounts his childhood in Denver as the son of a physician. He discusses his early academic career, his undergraduate years at Harvard, his time at the University of Colorado Medical School, and his decision to pursue medical research. He also talks about becoming a father and maintaining a work-life balance with his two children and wife, Kathryn. Cook Deegan shares his experience researching Alzheimer’s disease, as well as his rotation at the National Institutes of Health. Dr. Cook-Deegan details his work at the Office of Technology Assessment (OTA), including reports on aging, biotech, and the Human Genome Project, and offers an account of its eventual demise due to political changes. Other topics include the history of the Bermuda Principles, the role of political administrations on health policy, the current turn to Open Science, and Cook-Deegan's own relationship to collecting oral histories. He concludes the conversation with a reflection on the Trump administration’s recent decision to cut funding for many science-funding agencies
A chart of part of the south coast of Newfoundland [cartographic material] : includingthe islands St. Peters and Miquelon, from an actual survey /
No full textDetailed chart of part of the Newfoundland, Canadian coast with relief shown by hachures and bathymetric soundings.; "Scale to the general chart English and French leagues 20 to a degree"; Accompanied by booklet: Directions for navigating on part of the south coast of Newfoundland, with a chart thereof, including the islands of St. Peter's and Miquelon ... / by James Cook. London : Printed for the author, and sold by J.Mount and T. Page on Tower-Hill, 1766. 32 p. : 24 cm.; Insets: Harbours of St. Laurence; Harbour [of] Briton.; Also available in an electronic version via the Internet at: http://nla.gov.au/nla.map-rm423
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