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3. Radar for Europa Assessment and Sounding: Ocean to Near-Surface (REASON)

Author

Blankenship, Donald D., Moussessian, Alina, Chapin, Elaine, Young, Duncan A., Wesley Patterson, G., Plaut, Jeffrey J., Freedman, Adam P., Schroeder, Dustin M., Grima, Cyril, Steinbrügge, Gregor, Soderlund, Krista M., Ray, Trina, Richter, Thomas G., Jones-Wilson, Laura, Wolfenbarger, Natalie S., Scanlan, Kirk M., Gerekos, Christopher, Chan, Kristian, Seker, Ilgin, Haynes, Mark S., Barr Mlinar, Amy C., Bruzzone, Lorenzo, Campbell, Bruce A., Carter, Lynn M., Elachi, Charles, Gim, Yonggyu, Hérique, Alain, Hussmann, Hauke, Kofman, Wlodek, Kurth, William S., Mastrogiuseppe, Marco, McKinnon, William B., Moore, Jeffrey M., Nimmo, Francis, Paty, Carol, Plettemeier, Dirk, Schmidt, Britney E., Zolotov, Mikhail Y., Schenk, Paul M., Collins, Simon, Figueroa, Harry, Fischman, Mark, Tardiff, Eric, Berkun, Andy, Paller, Mimi, Hoffman, James P., Kurum, Andy, Sadowy, Gregory A., Wheeler, Kevin B., Decrossas, Emmanuel, Hussein, Yasser, Jin, Curtis, Boldissar, Frank, Chamberlain, Neil, Hernandez, Brenda, Maghsoudi, Elham, Mihaly, Jonathan, Worel, Shana, Singh, Vik, Pak, Kyung, Tanabe, Jordan, Johnson, Robert, Ashtijou, Mohammad, Alemu, Tafesse, Burke, Michael, Custodero, Brian, Tope, Michael C., Hawkins, David, Aaron, Kim, Delory, Gregory T., Turin, Paul S., Kirchner, Donald L., Srinivasan, Karthik, Xie, Julie, Ortloff, Brad, Tan, Ian, Noh, Tim, Clark, Duane, Duong, Vu, Joshi, Shivani, Lee, Jeng, Merida, Elvis, Akbar, Ruzbeh, Duan, Xueyang, Fenni, Ines, Sanchez-Barbetty, Mauricio, Parashare, Chaitali, Howard, Duane C., Newman, Julie, Cruz, Marvin G., Barabas, Neil J., Amirahmadi, Ahmadreza, Palmer, Brendon, Gawande, Rohit S., Milroy, Grace, Roberti, Rick, Leader, Frank E., West, Richard D., Martin, Jan, Venkatesh, Vijay, Adumitroaie, Virgil, Rains, Christine, Quach, Cuong, Turner, Jordi E., O’Shea, Colleen M., Kempf, Scott D., Ng, Gregory, Buhl, Dillon P., and Urban, Timothy J.

Published
2024
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4. eQTLs identify regulatory networks and drivers of variation in the individual response to sepsis

Author

Addison, Jenni, Galley, Helen, Hall, Sally, Roughton, Sian, Taylor, Jane, Tennant, Heather, Webster, Nigel, Guleri, Achyut, Waddington, Natalia, Arawwawala, Dilshan, Durcan, John, Mitchell-Inwang, Christine, Short, Alasdair, Smolen, Susan, Swan, Karen, Williams, Sarah, Errington, Emily, Gordon, Tony, Templeton, Maie, McCauley, Marie, Venatesh, Pyda, Ward, Geraldine, Baudouin, Simon, Grier, Sally, Hall, Elaine, Higham, Charley, Soar, Jasmeet, Brett, Stephen, Kitson, David, Moreno, Juan, Mountford, Laura, Wilson, Robert, Hall, Peter, Hewlett, Jackie, McKechnie, Stuart, Faras-Arraya, Roser, Garrard, Christopher, Hutton, Paula, Millo, Julian, Parsons, Penny, Smiths, Alex, Young, Duncan, Raymode, Parizade, Andreou, Prem, Bowrey, Sarah, Hales, Dawn, Kazembe, Sandra, Rich, Natalie, Roberts, Emma, Thompson, Jonathan, Fletcher, Simon, Glister, Georgina, Rosbergen, Melissa, Cuesta, Jeronimo Moreno, Bion, Julian, Carrera, Ronald, Lees, Sarah, Millar, Joanne, Mitchell, Natalie, Nilson, Annette, Perry, Elsa Jane, Ruel, Sebastian, Wilde, Jude, Willis, Heather, Atkinson, Jane, Brown, Abby, Jacques, Nicola, Kapila, Atul, Prowse, Heather, Bland, Martin, Bullock, Lynne, Harrison, Donna, Krige, Anton, Mills, Gary, Humphreys, John, Armitage, Kelsey, Laha, Shond, Baldwin, Jacqueline, Walsh, Angela, Doherty, Nicola, Drage, Stephen, Ortiz-Ruiz de Gordoa, Laura, Lowes, Sarah, Walsh, Helen, Calder, Verity, Swan, Catherine, Payne, Heather, Higgins, David, Andrews, Sarah, Mappleback, Sarah, Hinds, Charles, Watson, D., McLees, Eleanor, Purdy, Alice, Stotz, Martin, Ochelli-Okpue, Adaeze, Bonner, Stephen, Whitehead, Iain, Hugil, Keith, Goodridge, Victoria, Cawthor, Louisa, Kuper, Martin, Pahary, Sheik, Bellingan, Geoffrey, Marshall, Richard, Montgomery, Hugh, Ryu, Jung Hyun, Bercades, Georgia, Boluda, Susan, Bentley, Andrew, Mccalman, Katie, Jefferies, Fiona, Allcock, Alice, Burnham, Katie, Davenport, Emma, Geoghegan, Cyndi, Knight, Julian, Maugeri, Narelle, Mi, Yuxin, Radhakrishnan, Jayachandran, Burnham, Katie L., Milind, Nikhil, Lee, Wanseon, Kwok, Andrew J., Cano-Gamez, Kiki, Geoghegan, Cyndi G., Zhang, Ping, Soranzo, Nicole, Hinds, Charles J., Knight, Julian C., and Davenport, Emma E.

Published
2024
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5. The Scientific Legacy of NASA’s Operation IceBridge

Author

MacGregor, Joseph A, Boisvert, Linette N, Medley, Brooke, Petty, Alek A, Harbeck, Jeremy P, Bell, Robin E, Blair, J Bryan, Blanchard‐Wrigglesworth, Edward, Buckley, Ellen M, Christoffersen, Michael S, Cochran, James R, Csathó, Beáta M, Marco, Eugenia L, Dominguez, RoseAnne T, Fahnestock, Mark A, Farrell, Sinéad L, Gogineni, S Prasad, Greenbaum, Jamin S, Hansen, Christy M, Hofton, Michelle A, Holt, John W, Jezek, Kenneth C, Koenig, Lora S, Kurtz, Nathan T, Kwok, Ronald, Larsen, Christopher F, Leuschen, Carlton J, Locke, Caitlin D, Manizade, Serdar S, Martin, Seelye, Neumann, Thomas A, Nowicki, Sophie MJ, Paden, John D, Richter‐Menge, Jacqueline A, Rignot, Eric J, Rodríguez‐Morales, Fernando, Siegfried, Matthew R, Smith, Benjamin E, Sonntag, John G, Studinger, Michael, Tinto, Kirsty J, Truffer, Martin, Wagner, Thomas P, Woods, John E, Young, Duncan A, and Yungel, James K

Subjects
Climate Action, Physical Sciences, Earth Sciences, Engineering, Meteorology & Atmospheric Sciences
Abstract

The National Aeronautics and Space Administration (NASA)’s Operation IceBridge (OIB) was a 13-year (2009–2021) airborne mission to survey land and sea ice across the Arctic, Antarctic, and Alaska. Here, we review OIB’s goals, instruments, campaigns, key scientific results, and implications for future investigations of the cryosphere. OIB’s primary goal was to use airborne laser altimetry to bridge the gap in fine-resolution elevation measurements of ice from space between the conclusion of NASA’s Ice, Cloud, and land Elevation Satellite (ICESat; 2003–2009) and its follow-on, ICESat-2 (launched 2018). Additional scientific requirements were intended to contextualize observed elevation changes using a multisensor suite of radar sounders, gravimeters, magnetometers, and cameras. Using 15 different aircraft, OIB conducted 968 science flights, of which 42% were repeat surveys of land ice, 42% were surveys of previously unmapped terrain across the Greenland and Antarctic ice sheets, Arctic ice caps, and Alaskan glaciers, and 16% were surveys of sea ice. The combination of an expansive instrument suite and breadth of surveys enabled numerous fundamental advances in our understanding of the Earth’s cryosphere. For land ice, OIB dramatically improved knowledge of interannual outlet-glacier variability, ice-sheet, and outlet-glacier thicknesses, snowfall rates on ice sheets, fjord and sub-ice-shelf bathymetry, and ice-sheet hydrology. Unanticipated discoveries included a reliable method for constraining the thickness within difficult-to-sound incised troughs beneath ice sheets, the extent of the firn aquifer within the Greenland Ice Sheet, the vulnerability of many Greenland and Antarctic outlet glaciers to ocean-driven melting at their grounding zones, and the dominance of surface-melt-driven mass loss of Alaskan glaciers. For sea ice, OIB significantly advanced our understanding of spatiotemporal variability in sea ice freeboard and its snow cover, especially through combined analysis of fine-resolution altimetry, visible imagery, and snow radar measurements of the overlying snow thickness. Such analyses led to the unanticipated discovery of an interdecadal decrease in snow thickness on Arctic sea ice and numerous opportunities to validate sea ice freeboards from satellite radar altimetry. While many of its data sets have yet to be fully explored, OIB’s scientific legacy has already demonstrated the value of sustained investment in reliable airborne platforms, airborne instrument development, interagency and international collaboration, and open and rapid data access to advance our understanding of Earth’s remote polar regions and their role in the Earth system.

Published
2021

8. Exploring the Interior of Europa with the Europa Clipper

Author

Roberts, James H., McKinnon, William B., Elder, Catherine M., Tobie, Gabriel, Biersteker, John B., Young, Duncan, Park, Ryan S., Steinbrügge, Gregor, Nimmo, Francis, Howell, Samuel M., Castillo-Rogez, Julie C., Cable, Morgan L., Abrahams, Jacob N., Bland, Michael T., Chivers, Chase, Cochrane, Corey J., Dombard, Andrew J., Ernst, Carolyn, Genova, Antonio, Gerekos, Christopher, Glein, Christopher, Harris, Camilla D., Hay, Hamish C. F. C., Hayne, Paul O., Hedman, Matthew, Hussmann, Hauke, Jia, Xianzhe, Khurana, Krishan, Kiefer, Walter S., Kirk, Randolph, Kivelson, Margaret, Lawrence, Justin, Leonard, Erin J., Lunine, Jonathan I., Mazarico, Erwan, McCord, Thomas B., McEwen, Alfred, Paty, Carol, Quick, Lynnae C., Raymond, Carol A., Retherford, Kurt D., Roth, Lorenz, Rymer, Abigail, Saur, Joachim, Scanlan, Kirk, Schroeder, Dustin M., Senske, David A., Shao, Wencheng, Soderlund, Krista, Spiers, Elizabeth, Styczinski, Marshall J., Tortora, Paolo, Vance, Steven D., Villarreal, Michaela N., Weiss, Benjamin P., Westlake, Joseph H., Withers, Paul, Wolfenbarger, Natalie, Buratti, Bonnie, Korth, Haje, and Pappalardo, Robert T.

Published
2023
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9. The effects of ultra-selective beta1-antagonism on the metabolic and cytokine profile in septic shock patients receiving noradrenaline: a sub-investigation from the STRESS-L Randomised Study.

Author

Thomas, Jarrod L., McGee, Kirsty C., Hossain, Anower, Perkins, Gavin D., Gordon, Anthony C., Young, Duncan, McAuley, Danny, Singer, Mervyn, Lall, Ranjit, Kramaric, Tina, Lord, Janet M., Whitehouse, Tony, Mur, Luis A. J., Veenith, Tonny, Patel, Jaimin, Murphy, Nick, Bangash, Mansoor, Torlinski, Tomasz, Talbot, Nicholas, and Snelson, Catherine

Subjects
ELECTROSPRAY ionization mass spectrometry, SEPTIC shock, METABOLOMIC fingerprinting, SUCCINIC acid, BIOMARKERS
Abstract

Purpose: The landiolol and organ failure in patients with septic shock (STRESS-L study) included a pre-planned sub-study to assess the effect of landiolol treatment on inflammatory and metabolomic markers. Methods: Samples collected from 91 patients randomised to STRESS-L were profiled for immune and metabolomic markers. A panel of pro- and anti-inflammatory cytokines were measured through commercially acquired multiplex Luminex assays and statistically analysed by individual and cluster-level analysis (patient). Metabolite fingerprinting was carried out by flow infusion electrospray ionisation high-resolution mass spectrometry and metabolomic data were analysed using the R-based platform MetaboAnalyst. The metabolites were identified using DIMEdb (dimedb.ibers.aber.ac.uk) from their mass/charge ratios. These metabolomic data were also re-analysed using individual and cluster-level analysis. The individual-level models were adjusted for confounders, such as age, sex, noradrenaline dosage and patient (random effect). Results: Analysis was undertaken at cluster- and individual-level. There were no significant differences in cytokine concentration level between trial arms nor survivors and non-survivors over the duration of the observations from day 1 to day 4. Metabolomic analysis showed some separation in the levels of ceramides and cardiolipins between those who survived and those who died. Following adjusted analysis for confounders, plasma metabolite concentrations remained statistically different between landiolol and standard care arms for succinic acid, l-tryptophan, l-alanine, 2,2,2-trichloroethanol, lactic acid and d-glucose. Conclusions: In a study of ICU patients with established septic shock and a tachycardia, landiolol treatment used to reduce the heart rate from above 95 to a range between 80 and 94 beats per minute did not induce significant cytokine changes. d-Glucose, lactic acid, succinic acid, l-alanine, l-tryptophan and trichloroethanol were pathways that may merit further investigation. Trial Registration: EU Clinical Trials Register Eudra CT: 2017-001785-14 (https://www.clinicaltrialsregister.eu/ctr-search/trial/2017-001785-14/GB); ISRCTN registry Identifier: ISRCTN12600919 (https://www.isrctn.com/ISRCTN12600919). [ABSTRACT FROM AUTHOR]

Published
2025
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11. Basal channels drive active surface hydrology and transverse ice shelf fracture.

Author

Dow, Christine F, Lee, Won Sang, Greenbaum, Jamin S, Greene, Chad A, Blankenship, Donald D, Poinar, Kristin, Forrest, Alexander L, Young, Duncan A, and Zappa, Christopher J

Abstract

Ice shelves control sea-level rise through frictional resistance, which slows the seaward flow of grounded glacial ice. Evidence from around Antarctica indicates that ice shelves are thinning and weakening, primarily driven by warm ocean water entering into the shelf cavities. We have identified a mechanism for ice shelf destabilization where basal channels underneath the shelves cause ice thinning that drives fracture perpendicular to flow. These channels also result in ice surface deformation, which diverts supraglacial rivers into the transverse fractures. We report direct evidence that a major 2016 calving event at Nansen Ice Shelf in the Ross Sea was the result of fracture driven by such channelized thinning and demonstrate that similar basal channel-driven transverse fractures occur elsewhere in Greenland and Antarctica. In the event of increased basal and surface melt resulting from rising ocean and air temperatures, ice shelves will become increasingly vulnerable to these tandem effects of basal channel destabilization.

Published
2018

16. The Use of Primary Care Big Data in Understanding the Pharmacoepidemiology of COVID-19: A Consensus Statement From the COVID-19 Primary Care Database Consortium

Author

Dambha-Miller, Hajira, Griffin, Simon J., Young, Duncan, Watkinson, Peter, Tan, Pui San, Clift, Ashley K., Payne, Rupert A., Coupland, Carol, Hopewell, Jemma C., Mant, Jonathan, Martin, Richard M., and Hippisley-Cox, Julia

Subjects
Drug therapy, Usage, Research, Methods, Health aspects, Big data -- Usage -- Health aspects, Medical records -- Usage, Medical research -- Methods, COVID-19 -- Drug therapy -- Research, Primary health care, Medicine, Experimental -- Methods
Abstract

INTRODUCTION Primary care big data refers to routinely collected anonymized general practitioner (GP) electronic health records that form large and complex longitudinal databases, often with hundreds of variables at an [...], The use of big data containing millions of primary care medical records provides an opportunity for rapid research to help inform patient care and policy decisions during the first and subsequent waves of the coronavirus disease 2019 (COVID-19) pandemic. Routinely collected primary care data have previously been used for national pandemic surveillance, quantifying associations between exposures and outcomes, identifying high risk populations, and examining the effects of interventions at scale, but there is no consensus on how to effectively conduct or report these data for COVID-19 research. A COVID-19 primary care database consortium was established in April 2020 and its researchers have ongoing COVID-19 projects in overlapping data sets with over 40 million primary care records in the United Kingdom that are variously linked to public health, secondary care, and vital status records. This consensus agreement is aimed at facilitating transparency and rigor in methodological approaches, and consistency in defining and reporting cases, exposures, confounders, stratification variables, and outcomes in relation to the pharmacoepidemiology of COVID-19. This will facilitate comparison, validation, and meta-analyses of research during and after the pandemic. Key words: big data; coronavirus; epidemiology; primary health care

Published
2021
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17. Radar for Europa Assessment and Sounding:Ocean to Near-Surface (REASON)

Author

Blankenship, Donald D., Moussessian, Alina, Chapin, Elaine, Young, Duncan A., Wesley Patterson, G., Plaut, Jeffrey J., Freedman, Adam P., Schroeder, Dustin M., Grima, Cyril, Steinbrügge, Gregor, Soderlund, Krista M., Ray, Trina, Richter, Thomas G., Jones-Wilson, Laura, Wolfenbarger, Natalie S., Scanlan, Kirk M., Gerekos, Christopher, Chan, Kristian, Seker, Ilgin, Haynes, Mark S., Barr Mlinar, Amy C., Bruzzone, Lorenzo, Campbell, Bruce A., Carter, Lynn M., Elachi, Charles, Gim, Yonggyu, Hérique, Alain, Hussmann, Hauke, Kofman, Wlodek, Kurth, William S., Mastrogiuseppe, Marco, McKinnon, William B., Moore, Jeffrey M., Nimmo, Francis, Paty, Carol, Plettemeier, Dirk, Schmidt, Britney E., Zolotov, Mikhail Y., Schenk, Paul M., Collins, Simon, Figueroa, Harry, Fischman, Mark, Tardiff, Eric, Berkun, Andy, Paller, Mimi, Hoffman, James P., Kurum, Andy, Sadowy, Gregory A., Wheeler, Kevin B., Decrossas, Emmanuel, Hussein, Yasser, Jin, Curtis, Boldissar, Frank, Chamberlain, Neil, Hernandez, Brenda, Maghsoudi, Elham, Mihaly, Jonathan, Worel, Shana, Singh, Vik, Pak, Kyung, Tanabe, Jordan, Johnson, Robert, Ashtijou, Mohammad, Alemu, Tafesse, Burke, Michael, Custodero, Brian, Tope, Michael C., Hawkins, David, Aaron, Kim, Delory, Gregory T., Turin, Paul S., Kirchner, Donald L., Srinivasan, Karthik, Xie, Julie, Ortloff, Brad, Tan, Ian, Noh, Tim, Clark, Duane, Duong, Vu, Joshi, Shivani, Lee, Jeng, Merida, Elvis, Akbar, Ruzbeh, Duan, Xueyang, Fenni, Ines, Sanchez-Barbetty, Mauricio, Parashare, Chaitali, Howard, Duane C., Newman, Julie, Cruz, Marvin G., Barabas, Neil J., Amirahmadi, Ahmadreza, Palmer, Brendon, Gawande, Rohit S., Milroy, Grace, Roberti, Rick, Leader, Frank E., West, Richard D., Martin, Jan, Venkatesh, Vijay, Adumitroaie, Virgil, Rains, Christine, Quach, Cuong, Turner, Jordi E., O’Shea, Colleen M., Kempf, Scott D., Ng, Gregory, Buhl, Dillon P., Urban, Timothy J., Blankenship, Donald D., Moussessian, Alina, Chapin, Elaine, Young, Duncan A., Wesley Patterson, G., Plaut, Jeffrey J., Freedman, Adam P., Schroeder, Dustin M., Grima, Cyril, Steinbrügge, Gregor, Soderlund, Krista M., Ray, Trina, Richter, Thomas G., Jones-Wilson, Laura, Wolfenbarger, Natalie S., Scanlan, Kirk M., Gerekos, Christopher, Chan, Kristian, Seker, Ilgin, Haynes, Mark S., Barr Mlinar, Amy C., Bruzzone, Lorenzo, Campbell, Bruce A., Carter, Lynn M., Elachi, Charles, Gim, Yonggyu, Hérique, Alain, Hussmann, Hauke, Kofman, Wlodek, Kurth, William S., Mastrogiuseppe, Marco, McKinnon, William B., Moore, Jeffrey M., Nimmo, Francis, Paty, Carol, Plettemeier, Dirk, Schmidt, Britney E., Zolotov, Mikhail Y., Schenk, Paul M., Collins, Simon, Figueroa, Harry, Fischman, Mark, Tardiff, Eric, Berkun, Andy, Paller, Mimi, Hoffman, James P., Kurum, Andy, Sadowy, Gregory A., Wheeler, Kevin B., Decrossas, Emmanuel, Hussein, Yasser, Jin, Curtis, Boldissar, Frank, Chamberlain, Neil, Hernandez, Brenda, Maghsoudi, Elham, Mihaly, Jonathan, Worel, Shana, Singh, Vik, Pak, Kyung, Tanabe, Jordan, Johnson, Robert, Ashtijou, Mohammad, Alemu, Tafesse, Burke, Michael, Custodero, Brian, Tope, Michael C., Hawkins, David, Aaron, Kim, Delory, Gregory T., Turin, Paul S., Kirchner, Donald L., Srinivasan, Karthik, Xie, Julie, Ortloff, Brad, Tan, Ian, Noh, Tim, Clark, Duane, Duong, Vu, Joshi, Shivani, Lee, Jeng, Merida, Elvis, Akbar, Ruzbeh, Duan, Xueyang, Fenni, Ines, Sanchez-Barbetty, Mauricio, Parashare, Chaitali, Howard, Duane C., Newman, Julie, Cruz, Marvin G., Barabas, Neil J., Amirahmadi, Ahmadreza, Palmer, Brendon, Gawande, Rohit S., Milroy, Grace, Roberti, Rick, Leader, Frank E., West, Richard D., Martin, Jan, Venkatesh, Vijay, Adumitroaie, Virgil, Rains, Christine, Quach, Cuong, Turner, Jordi E., O’Shea, Colleen M., Kempf, Scott D., Ng, Gregory, Buhl, Dillon P., and Urban, Timothy J.

Abstract

The Radar for Europa Assessment and Sounding: Ocean to Near-surface (REASON) is a dual-frequency ice-penetrating radar (9 and 60 MHz) onboard the Europa Clipper mission. REASON is designed to probe Europa from exosphere to subsurface ocean, contributing the third dimension to observations of this enigmatic world. The hypotheses REASON will test are that (1) the ice shell of Europa hosts liquid water, (2) the ice shell overlies an ocean and is subject to tidal flexing, and (3) the exosphere, near-surface, ice shell, and ocean participate in material exchange essential to the habitability of this moon. REASON will investigate processes governing this material exchange by characterizing the distribution of putative non-ice material (e.g., brines, salts) in the subsurface, searching for an ice–ocean interface, characterizing the ice shell’s global structure, and constraining the amplitude of Europa’s radial tidal deformations. REASON will accomplish these science objectives using a combination of radar measurement techniques including altimetry, reflectometry, sounding, interferometry, plasma characterization, and ranging. Building on a rich heritage from Earth, the moon, and Mars, REASON will be the first ice-penetrating radar to explore the outer solar system. Because these radars are untested for the icy worlds in the outer solar system, a novel approach to measurement quality assessment was developed to represent uncertainties in key properties of Europa that affect REASON performance and ensure robustness across a range of plausible parameters suggested for the icy moon. REASON will shed light on a never-before-seen dimension of Europa and – in concert with other instruments on Europa Clipper – help to investigate whether Europa is a habitable world.

Published
2024

18. Dated radar-stratigraphy between Dome A and South Pole, East Antarctica: old ice potential and ice sheet history

Author

Sanderson, Rebecca J., Ross, Neil, Winter, Kate, Bingham, Robert G., Callard, S. Louise, Jordan, Tom A., Young, Duncan A., Sanderson, Rebecca J., Ross, Neil, Winter, Kate, Bingham, Robert G., Callard, S. Louise, Jordan, Tom A., and Young, Duncan A.

Abstract

An array of information about the Antarctic ice sheet can be extracted from ice-sheet internal architecture imaged by airborne ice-penetrating radar surveys. We identify, trace and date three key internal reflection horizons (IRHs) across multiple radar surveys from South Pole to Dome A, East Antarctica. Ages of ∼38±2.2, ∼90±3.6 and ∼162±6.7ka are assigned to the three IRHs, with verification of the upper IRH age from the South Pole ice core. The resultant englacial stratigraphy is used to identify the locations of the oldest ice, specifically in the upper Byrd Glacier catchment and the Gamburtsev Subglacial Mountains. The distinct glaciological conditions of the Gamburtsev Mountains, including slower ice flow, low geothermal heat flux and frozen base, make it the more likely to host the oldest ice. We also observe a distinct drawdown of IRH geometry around South Pole, indicative of melting from enhanced geothermal heat flux or the removal of deeper, older ice under a previous faster ice flow regime. Our traced IRHs underpin the wider objective to develop a continental-scale database of IRHs which will constrain and validate future ice-sheet modelling and the history of the Antarctic ice sheet.

Published
2024

21. Comprehensive multi frequency airborne mapping of the southern flank of Dome A: results of the COLDEX airborne program.

Author

Young, Duncan, primary, Paden, John, additional, Kerr, Megan, additional, Singh, Shivangini, additional, Kaundinya, Shravan, additional, Yan, Shuai, additional, Vega González, Alejandra, additional, Greenbaum, Jamin, additional, Buhl, Dillon, additional, Ng, Gregory, additional, Chan, Kristian, additional, Schroeder, Bradley, additional, Echeverry, Gonzalo, additional, Richter, Thomas, additional, Kempf, Scott, additional, Rodriguez-Morales, Fernando, additional, Hale, Richard, additional, Blankenship, Donald, additional, and Brook, Edward, additional

Published
2024
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31. Deep glacial troughs and stabilizing ridges unveiled beneath the margins of the Antarctic ice sheet

Author

Morlighem, Mathieu, Rignot, Eric, Binder, Tobias, Blankenship, Donald, Drews, Reinhard, Eagles, Graeme, Eisen, Olaf, Ferraccioli, Fausto, Forsberg, René, Fretwell, Peter, Goel, Vikram, Greenbaum, Jamin S., Gudmundsson, Hilmar, Guo, Jingxue, Helm, Veit, Hofstede, Coen, Howat, Ian, Humbert, Angelika, Jokat, Wilfried, Karlsson, Nanna B., Lee, Won Sang, Matsuoka, Kenichi, Millan, Romain, Mouginot, Jeremie, Paden, John, Pattyn, Frank, Roberts, Jason, Rosier, Sebastian, Ruppel, Antonia, Seroussi, Helene, Smith, Emma C., Steinhage, Daniel, Sun, Bo, Broeke, Michiel R. van den, Ommen, Tas D. van, Wessem, Melchior van, and Young, Duncan A.

Published
2020
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32. A Reconciled Estimate of Ice-Sheet Mass Balance

Author

Shepherd, Andrew, Ivins, Erik R, A, Geruo, Barletta, Valentina R, Bentley, Mike J, Bettadpur, Srinivas, Briggs, Kate H, Bromwich, David H, Forsberg, René, Galin, Natalia, Horwath, Martin, Jacobs, Stan, Joughin, Ian, King, Matt A, Lenaerts, Jan TM, Li, Jilu, Ligtenberg, Stefan RM, Luckman, Adrian, Luthcke, Scott B, McMillan, Malcolm, Meister, Rakia, Milne, Glenn, Mouginot, Jeremie, Muir, Alan, Nicolas, Julien P, Paden, John, Payne, Antony J, Pritchard, Hamish, Rignot, Eric, Rott, Helmut, Sørensen, Louise Sandberg, Scambos, Ted A, Scheuchl, Bernd, Schrama, Ernst JO, Smith, Ben, Sundal, Aud V, van Angelen, Jan H, van de Berg, Willem J, van den Broeke, Michiel R, Vaughan, David G, Velicogna, Isabella, Wahr, John, Whitehouse, Pippa L, Wingham, Duncan J, Yi, Donghui, Young, Duncan, and Zwally, H Jay

Subjects
Climate Action, Antarctic Regions, Climate Change, Geographic Information Systems, Greenland, Ice Cover, General Science & Technology
Abstract

We combined an ensemble of satellite altimetry, interferometry, and gravimetry data sets using common geographical regions, time intervals, and models of surface mass balance and glacial isostatic adjustment to estimate the mass balance of Earth's polar ice sheets. We find that there is good agreement between different satellite methods--especially in Greenland and West Antarctica--and that combining satellite data sets leads to greater certainty. Between 1992 and 2011, the ice sheets of Greenland, East Antarctica, West Antarctica, and the Antarctic Peninsula changed in mass by -142 ± 49, +14 ± 43, -65 ± 26, and -20 ± 14 gigatonnes year(-1), respectively. Since 1992, the polar ice sheets have contributed, on average, 0.59 ± 0.20 millimeter year(-1) to the rate of global sea-level rise.

Published
2012

33. Network-driven cancer cell avatars for combination discovery and biomarker identification for DNA Damage Response inhibitors

Author

Papp, Orsolya, primary, Jordán, Viktória, additional, Hetey, Szabolcs, additional, Balázs, Róbert, additional, Bartha, Árpád, additional, Ordasi, Nóra N., additional, Kamp, Sebestyén, additional, Farkas, Bálint, additional, Mettetal, Jay, additional, Dry, Jonathan R., additional, Young, Duncan, additional, Veres, Dániel, additional, Sidders, Ben, additional, and Bulusu, Krishna C., additional

Published
2023
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40. Antarctic Bedmap data: Findable, Accessible, Interoperable, and Reusable (FAIR) sharing of 60 years of ice bed, surface, and thickness data

Author

Frémand, Alice C., primary, Fretwell, Peter, additional, Bodart, Julien A., additional, Pritchard, Hamish D., additional, Aitken, Alan, additional, Bamber, Jonathan L., additional, Bell, Robin, additional, Bianchi, Cesidio, additional, Bingham, Robert G., additional, Blankenship, Donald D., additional, Casassa, Gino, additional, Catania, Ginny, additional, Christianson, Knut, additional, Conway, Howard, additional, Corr, Hugh F. J., additional, Cui, Xiangbin, additional, Damaske, Detlef, additional, Damm, Volkmar, additional, Drews, Reinhard, additional, Eagles, Graeme, additional, Eisen, Olaf, additional, Eisermann, Hannes, additional, Ferraccioli, Fausto, additional, Field, Elena, additional, Forsberg, René, additional, Franke, Steven, additional, Fujita, Shuji, additional, Gim, Yonggyu, additional, Goel, Vikram, additional, Gogineni, Siva Prasad, additional, Greenbaum, Jamin, additional, Hills, Benjamin, additional, Hindmarsh, Richard C. A., additional, Hoffman, Andrew O., additional, Holmlund, Per, additional, Holschuh, Nicholas, additional, Holt, John W., additional, Horlings, Annika N., additional, Humbert, Angelika, additional, Jacobel, Robert W., additional, Jansen, Daniela, additional, Jenkins, Adrian, additional, Jokat, Wilfried, additional, Jordan, Tom, additional, King, Edward, additional, Kohler, Jack, additional, Krabill, William, additional, Kusk Gillespie, Mette, additional, Langley, Kirsty, additional, Lee, Joohan, additional, Leitchenkov, German, additional, Leuschen, Carlton, additional, Luyendyk, Bruce, additional, MacGregor, Joseph, additional, MacKie, Emma, additional, Matsuoka, Kenichi, additional, Morlighem, Mathieu, additional, Mouginot, Jérémie, additional, Nitsche, Frank O., additional, Nogi, Yoshifumi, additional, Nost, Ole A., additional, Paden, John, additional, Pattyn, Frank, additional, Popov, Sergey V., additional, Rignot, Eric, additional, Rippin, David M., additional, Rivera, Andrés, additional, Roberts, Jason, additional, Ross, Neil, additional, Ruppel, Anotonia, additional, Schroeder, Dustin M., additional, Siegert, Martin J., additional, Smith, Andrew M., additional, Steinhage, Daniel, additional, Studinger, Michael, additional, Sun, Bo, additional, Tabacco, Ignazio, additional, Tinto, Kirsty, additional, Urbini, Stefano, additional, Vaughan, David, additional, Welch, Brian C., additional, Wilson, Douglas S., additional, Young, Duncan A., additional, and Zirizzotti, Achille, additional

Published
2023
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42. Antarctic Bedmap data: Findable, Accessible, Interoperable, and Reusable (FAIR) sharing of 60 years of ice bed, surface, and thickness data

Author

Frémand, Alice C., Fretwell, Peter, Bodart, Julien A., Pritchard, Hamish D., Aitken, Alan, Bamber, Jonathan L., Bell, Robin, Bianchi, Cesido, Bingham, Robert G., Blankenship, Donald D., Casassa, Gino, Catania, Ginny, Christianson, Knut, Conway, Howard, Corr, Hugh F.J., Cui, Xiangbin, Damaske, Detlef, Damm, Volkmar, Drews, Reinhard, Eagles, Graeme, Eisen, Olaf, Eisermann, Hannes, Ferraccioli, Fausto, Field, Elena, Forsberg, René, Franke, Steven, Fujita, Shuji, Gim, Yonggyu, Goel, Vikram, Gogineni, Siva Prasad, Greenbaum, Jamin, Hills, Benjamin, Hindmarsh, Richard C.A., Hoffman, Andrew O., Holmlund, Per, Holschuh, Nicholas, Holt, John W., Horlings, Anneka N., Humbert, Anglika, Jacobel, Robert W., Jansen, Daniela, Jenkins, Adrian, Jokat, Wilfried, Jordan, Tom, King, Edward, Kohler, Jack, Krabill, William, Langley, Kirsty, Lee, Joohan, Leitchenkov, German, Leuschen, Carlton, Luyendyk, Bruce, MacGregor, Joseph, MacKie, Emma, Matsuoka, Kenichi, Morlighem, Mathieu, Mouginot, Jérémie, Nitsche, Frank O., Nogi, Yoshifumi, Nost, Ole A., Paden, John, Pattyn, Frank, Popov, Sergey V., Rignot, Eric, Rippin, David M., Rivera, Andrés, Roberts, Jason, Ross, Neil, Ruppel, Anotonia, Schroeder, Dustin M., Siegert, Martin J., Smith, Andrew M., Steinhage, Daniel, Studinger, Michael, Sun, Bo, Tabacco, Ignazio, Tinto, Kirsty, Urbini, Stefano, Vaughan, David, Welch, Brian C., Wilson, Douglas S., Young, Duncan A., and Zirizzotti, Achille

Abstract

One of the key components of this research has been the mapping of Antarctic bed topography and ice thickness parameters that are crucial for modelling ice flow and hence for predicting future ice loss and the ensuing sea level rise. Supported by the Scientific Committee on Antarctic Research (SCAR), the Bedmap3 Action Group aims not only to produce new gridded maps of ice thickness and bed topography for the international scientific community, but also to standardize and make available all the geophysical survey data points used in producing the Bedmap gridded products. Here, we document the survey data used in the latest iteration, Bedmap3, incorporating and adding to all of the datasets previously used for Bedmap1 and Bedmap2, including ice bed, surface and thickness point data from all Antarctic geophysical campaigns since the 1950s. More specifically, we describe the processes used to standardize and make these and future surveys and gridded datasets accessible under the Findable, Accessible, Interoperable, and Reusable (FAIR) data principles. With the goals of making the gridding process reproducible and allowing scientists to re-use the data freely for their own analysis, we introduce the new SCAR Bedmap Data Portal (https://bedmap.scar.org, last access: 1 March 2023) created to provide unprecedented open access to these important datasets through a web-map interface. We believe that this data release will be a valuable asset to Antarctic research and will greatly extend the life cycle of the data held within it. Data are available from the UK Polar Data Centre: https://data.bas.ac.uk (last access: 5 May 2023​​​​​​​). See the Data availability section for the complete list of datasets.

Published
2023

43. Geophysical mapping of the southern flank of Dome A, Antarctica: Initial results from the inaugural COLDEX airborne survey

Author

Kerr, Megan, Young, Duncan, Richter, Thomas, Blankenship, Donald, Buhl, Dillon, Chan, Kristian, Greenbaum, Jamin, Kaundinya, Shravan, Kempf, Scott, Liu-Schiaffini, Miguel, Ng, Gregory, Paden, John, and Yan, Shuai

Abstract

The acquisition of a stratigraphically intact Antarctic ice column spanning the past 1.5 million years requires understanding of the thermal state of both the basal layer of the ice sheet and the underlying bed, which are influenced strongly by the coupled boundary conditions of geothermal heat flow and accumulation rate. However, geothermal heat flow, crustal structure, lithology, and other geological controls on thermal and hydraulic conductivity are poorly understood for likely ‘old ice’ regions of Antarctica. In the 2022/23 Antarctic field season, we collected over 20,000 line km of new airborne radar, magnetics, and gravity data over a poorly-surveyed region of the East Antarctic Ice Sheet between Dome A and the South Pole. We present updated maps of subglacial topography and ice thickness, as well as free-air and Bouguer anomaly grids, which can be used to make preliminary inferences about the crustal framework and basal thermal regime of the study area. These data, supplemented by existing geophysical observations, will inform further airborne and ground-based geophysical surveys and provide important context for ice flow models and selection of potential sites for old ice drilling operations., The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)

Published
2023

45. Antarctic Bedmap data: Findable, Accessible, Interoperable, and Reusable (FAIR) sharing of 60 years of ice bed, surface, and thickness data

Author

Frémand, Alice C, Fretwell, Peter, Bodart, Julien A, Pritchard, Hamish D, Aitken, Alan, Bamber, Jonathan L, Bell, Robin, Bianchi, Cesidio, Bingham, Robert G, Blankenship, Donald D, Casassa, Gino, Catania, Ginny, Christianson, Knut, Conway, Howard, Corr, Hugh FJ, Cui, Xiangbin, Damaske, Detlef, Damm, Volkmar, Drews, Reinhard, Eagles, Graeme, Eisen, Olaf, Eisermann, Hannes, Ferraccioli, Fausto, Field, Elena, Forsberg, René, Franke, Steven, Fujita, Shuji, Gim, Yonggyu, Goel, Vikram, Gogineni, Siva Prasad, Greenbaum, Jamin, Hills, Benjamin, Hindmarsh, Richard CA, Hoffman, Andrew O, Holmlund, Per, Holschuh, Nicholas, Holt, John W, Horlings, Annika N, Humbert, Angelika, Jacobel, Robert W, Jansen, Daniela, Jenkins, Adrian, Jokat, Wilfried, Jordan, Tom, King, Edward, Kohler, Jack, Krabill, William, Gillespie, Mette Kusk, Langley, Kirsty, Lee, Joohan, Leitchenkov, German, Leuschen, Carlton, Luyendyk, Bruce, MacGregor, Joseph, MacKie, Emma, Matsuoka, Kenichi, Morlighem, Mathieu, Mouginot, Jérémie, Nitsche, Frank O, Nogi, Yoshifumi, Nost, Ole A, Paden, John, Pattyn, Frank, Popov, Sergey V, Rignot, Eric, Rippin, David M, Rivera, Andrés, Roberts, Jason, Ross, Neil, Ruppel, Anotonia, Schroeder, Dustin M, Siegert, Martin J, Smith, Andrew M, Steinhage, Daniel, Studinger, Michael, Sun, Bo, Tabacco, Ignazio, Tinto, Kirsty, Urbini, Stefano, Vaughan, David, Welch, Brian C, Wilson, Douglas S, Young, Duncan A, Zirizzotti, Achille, Frémand, Alice C, Fretwell, Peter, Bodart, Julien A, Pritchard, Hamish D, Aitken, Alan, Bamber, Jonathan L, Bell, Robin, Bianchi, Cesidio, Bingham, Robert G, Blankenship, Donald D, Casassa, Gino, Catania, Ginny, Christianson, Knut, Conway, Howard, Corr, Hugh FJ, Cui, Xiangbin, Damaske, Detlef, Damm, Volkmar, Drews, Reinhard, Eagles, Graeme, Eisen, Olaf, Eisermann, Hannes, Ferraccioli, Fausto, Field, Elena, Forsberg, René, Franke, Steven, Fujita, Shuji, Gim, Yonggyu, Goel, Vikram, Gogineni, Siva Prasad, Greenbaum, Jamin, Hills, Benjamin, Hindmarsh, Richard CA, Hoffman, Andrew O, Holmlund, Per, Holschuh, Nicholas, Holt, John W, Horlings, Annika N, Humbert, Angelika, Jacobel, Robert W, Jansen, Daniela, Jenkins, Adrian, Jokat, Wilfried, Jordan, Tom, King, Edward, Kohler, Jack, Krabill, William, Gillespie, Mette Kusk, Langley, Kirsty, Lee, Joohan, Leitchenkov, German, Leuschen, Carlton, Luyendyk, Bruce, MacGregor, Joseph, MacKie, Emma, Matsuoka, Kenichi, Morlighem, Mathieu, Mouginot, Jérémie, Nitsche, Frank O, Nogi, Yoshifumi, Nost, Ole A, Paden, John, Pattyn, Frank, Popov, Sergey V, Rignot, Eric, Rippin, David M, Rivera, Andrés, Roberts, Jason, Ross, Neil, Ruppel, Anotonia, Schroeder, Dustin M, Siegert, Martin J, Smith, Andrew M, Steinhage, Daniel, Studinger, Michael, Sun, Bo, Tabacco, Ignazio, Tinto, Kirsty, Urbini, Stefano, Vaughan, David, Welch, Brian C, Wilson, Douglas S, Young, Duncan A, and Zirizzotti, Achille

Abstract

One of the key components of this research has been the mapping of Antarctic bed topography and ice thickness parameters that are crucial for modelling ice flow and hence for predicting future ice loss and the ensuing sea level rise. Supported by the Scientific Committee on Antarctic Research (SCAR), the Bedmap3 Action Group aims not only to produce new gridded maps of ice thickness and bed topography for the international scientific community, but also to standardize and make available all the geophysical survey data points used in producing the Bedmap gridded products. Here, we document the survey data used in the latest iteration, Bedmap3, incorporating and adding to all of the datasets previously used for Bedmap1 and Bedmap2, including ice bed, surface and thickness point data from all Antarctic geophysical campaigns since the 1950s. More specifically, we describe the processes used to standardize and make these and future surveys and gridded datasets accessible under the Findable, Accessible, Interoperable, and Reusable (FAIR) data principles. With the goals of making the gridding process reproducible and allowing scientists to re-use the data freely for their own analysis, we introduce the new SCAR Bedmap Data Portal (https://bedmap.scar.org, last access: 1 March 2023) created to provide unprecedented open access to these important datasets through a web-map interface. We believe that this data release will be a valuable asset to Antarctic research and will greatly extend the life cycle of the data held within it. Data are available from the UK Polar Data Centre: https://data.bas.ac.uk (last access: 5 May 2023). See the Data availability section for the complete list of datasets.

Published
2023

46. Exploring the Interior of Europa with the Europa Clipper

Author

Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences, Roberts, James H., McKinnon, William B., Elder, Catherine M., Tobie, Gabriel, Biersteker, John B., Young, Duncan, Park, Ryan S., Steinbrügge, Gregor, Nimmo, Francis, Howell, Samuel M., Castillo-Rogez, Julie C., Cable, Morgan L., Abrahams, Jacob N., Bland, Michael T., Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences, Roberts, James H., McKinnon, William B., Elder, Catherine M., Tobie, Gabriel, Biersteker, John B., Young, Duncan, Park, Ryan S., Steinbrügge, Gregor, Nimmo, Francis, Howell, Samuel M., Castillo-Rogez, Julie C., Cable, Morgan L., Abrahams, Jacob N., and Bland, Michael T.

Abstract

The Galileo mission to Jupiter revealed that Europa is an ocean world. The Galileo magnetometer experiment in particular provided strong evidence for a salty subsurface ocean beneath the ice shell, likely in contact with the rocky core. Within the ice shell and ocean, a number of tectonic and geodynamic processes may operate today or have operated at some point in the past, including solid ice convection, diapirism, subsumption, and interstitial lake formation. The science objectives of the Europa Clipper mission include the characterization of Europa’s interior; confirmation of the presence of a subsurface ocean; identification of constraints on the depth to this ocean, and on its salinity and thickness; and determination of processes of material exchange between the surface, ice shell, and ocean. Three broad categories of investigation are planned to interrogate different aspects of the subsurface structure and properties of the ice shell and ocean: magnetic induction, subsurface radar sounding, and tidal deformation. These investigations are supplemented by several auxiliary measurements. Alone, each of these investigations will reveal unique information. Together, the synergy between these investigations will expose the secrets of the Europan interior in unprecedented detail, an essential step in evaluating the habitability of this ocean world.

Published
2023

47. Antarctic Bedmap data: Findable, Accessible, Interoperable, and Reusable (FAIR) sharing of 60 years of ice bed, surface, and thickness data

Author

Frémand, Alice, Fretwell, Peter, Bodart, Julien A., Pritchard, Hamish D., Aitken, Alan, Bamber, Jonathan L., Bell, Robin, Bianchi, Cesidio, Bingham, Robert G., Blankenship, Donald, Casassa, Gino, Catania, Ginny, Christianson, Knut, Conway, Howard, Corr, Hugh F. J., Cui, Xiangbin, Damaske, Detlef, Damm, Volkmar, Drews, Reinhard, Eagles, Graeme, Eisen, Olaf, Eisermann, Hannes, Ferraccioli, Fausto, Field, Elena, Forsberg, René, Franke, Steven, Fujita, Shuji, Gim, Yonggyu, Goel, Vikram, Gogineni, Siva Prasad, Greenbaum, Jamin Stevens, Hills, Benjamin, Hindmarsh, Richard C. A., Hoffman, Andrew O., Holmlund, Per, Holschuh, Nicholas, Holt, John W., Horlings, Annika, Humbert, Angelika, Jacobel, Robert, Jansen, Daniela, Jenkins, Adrian, Jokat, Wilfried, Jordan, Tom, King, Edward, Kohler, Jack, Krabill, William, Kusk Gillespie, Mette, Langley, Kirsty, Lee, Joohan, Leitchenkov, German, Leuschen, Carlton, Luyendyk, Bruce, MacGregor, Joseph A., MacKie, Emma, Matsuoka, Kenichi, Morlighem, Mathieu, Mouginot, Jeremie, Nitsche, Frank, Nogi, Yoshifumi, Nost, Ole, Paden, John, Pattyn, Frank, Popov, Sergey V., Rignot, Eric, Rippin, David, Medina-Rivera, Alejandra, Roberts, Jason, Ross, Neil, Ruppel, Anotonia, Schroeder, Dustin M., Siegert, Martin J., Smith, Andrew M., Steinhage, Daniel, Studinger, Michael, Sun, Bo, Tabacco, Ignazio, Tinto, Kirsty, Urbini, Stefano, Vaughan, David, Welch, Brian, Wilson, Douglas S., Young, Duncan A., Zirizzotti, Achille, Frémand, Alice, Fretwell, Peter, Bodart, Julien A., Pritchard, Hamish D., Aitken, Alan, Bamber, Jonathan L., Bell, Robin, Bianchi, Cesidio, Bingham, Robert G., Blankenship, Donald, Casassa, Gino, Catania, Ginny, Christianson, Knut, Conway, Howard, Corr, Hugh F. J., Cui, Xiangbin, Damaske, Detlef, Damm, Volkmar, Drews, Reinhard, Eagles, Graeme, Eisen, Olaf, Eisermann, Hannes, Ferraccioli, Fausto, Field, Elena, Forsberg, René, Franke, Steven, Fujita, Shuji, Gim, Yonggyu, Goel, Vikram, Gogineni, Siva Prasad, Greenbaum, Jamin Stevens, Hills, Benjamin, Hindmarsh, Richard C. A., Hoffman, Andrew O., Holmlund, Per, Holschuh, Nicholas, Holt, John W., Horlings, Annika, Humbert, Angelika, Jacobel, Robert, Jansen, Daniela, Jenkins, Adrian, Jokat, Wilfried, Jordan, Tom, King, Edward, Kohler, Jack, Krabill, William, Kusk Gillespie, Mette, Langley, Kirsty, Lee, Joohan, Leitchenkov, German, Leuschen, Carlton, Luyendyk, Bruce, MacGregor, Joseph A., MacKie, Emma, Matsuoka, Kenichi, Morlighem, Mathieu, Mouginot, Jeremie, Nitsche, Frank, Nogi, Yoshifumi, Nost, Ole, Paden, John, Pattyn, Frank, Popov, Sergey V., Rignot, Eric, Rippin, David, Medina-Rivera, Alejandra, Roberts, Jason, Ross, Neil, Ruppel, Anotonia, Schroeder, Dustin M., Siegert, Martin J., Smith, Andrew M., Steinhage, Daniel, Studinger, Michael, Sun, Bo, Tabacco, Ignazio, Tinto, Kirsty, Urbini, Stefano, Vaughan, David, Welch, Brian, Wilson, Douglas S., Young, Duncan A., and Zirizzotti, Achille

Abstract

One of the key components of this research has been the mapping of Antarctic bed topography and ice thickness parameters that are crucial for modelling ice flow and hence for predicting future ice loss andthe ensuing sea level rise. Supported by the Scientific Committee on Antarctic Research (SCAR), the Bedmap3 Action Group aims not only to produce newgridded maps of ice thickness and bed topography for the internationalscientific community, but also to standardize and make available all thegeophysical survey data points used in producing the Bedmap griddedproducts. Here, we document the survey data used in the latest iteration,Bedmap3, incorporating and adding to all of the datasets previously used forBedmap1 and Bedmap2, including ice bed, surface and thickness point data from all Antarctic geophysical campaigns since the 1950s. More specifically,we describe the processes used to standardize and make these and futuresurveys and gridded datasets accessible under the Findable, Accessible, Interoperable, and Reusable (FAIR) data principles. With the goals of making the gridding process reproducible and allowing scientists to re-use the data freely for their own analysis, we introduce the new SCAR Bedmap Data Portal(https://bedmap.scar.org, last access: 1 March 2023) created to provideunprecedented open access to these important datasets through a web-map interface. We believe that this data release will be a valuable asset to Antarctic research and will greatly extend the life cycle of the data heldwithin it. Data are available from the UK Polar Data Centre: https://data.bas.ac.uk (last access: 5 May 2023​​​​​​​). See the Data availability section for the complete list of datasets., info:eu-repo/semantics/published

Published
2023

48. High mid-Holocene accumulation rates over West Antarctica inferred from a pervasive ice-penetrating radar reflector

Author

Bodart, Julien A., Bingham, Robert G., Young, Duncan A., MacGregor, Joseph A., Ashmore, David W., Quartini, Enrica, Hein, Andrew S., Vaughan, David G., Blakenship, Donald D., Bodart, Julien A., Bingham, Robert G., Young, Duncan A., MacGregor, Joseph A., Ashmore, David W., Quartini, Enrica, Hein, Andrew S., Vaughan, David G., and Blakenship, Donald D.

Abstract

Understanding the past and future evolution of the Antarctic Ice Sheet is challenged by the availability and quality of observed paleo-boundary conditions. Numerical ice-sheet models often rely on these paleo-boundary conditions to guide and evaluate their models' predictions of sea-level rise, with varying levels of confidence due to the sparsity of existing data across the ice sheet. A key data source for large-scale reconstruction of past ice-sheet processes are internal reflecting horizons (IRHs) detected by radio-echo sounding (RES). When IRHs are isochronal and dated at ice cores, they can be used to determine paleo-accumulation rates and patterns on large spatial scales. Using a spatially extensive IRH over the Pine Island Glacier (PIG), Thwaites Glacier (THW), and the Institute and Möller ice streams (IMIS, covering a total of 610 000 km2 or 30 % of the West Antarctic Ice Sheet (WAIS)), and a local layer approximation model, we infer mid-Holocene accumulation rates over the slow-flowing parts of these catchments for the past ∼4700 years. By comparing our results with modern climate reanalysis models (1979–2019) and observational syntheses (1651–2010), we estimate that accumulation rates over the Amundsen–Weddell–Ross Divide were on average 18 % higher during the mid-Holocene than modern rates. However, no significant spatial changes in the accumulation pattern were observed. The higher mid-Holocene accumulation-rate estimates match previous paleo-accumulation estimates from ice-core records and targeted RES surveys over the ice divide, and they also coincide with periods of grounding-line readvance during the Holocene over the Weddell and Ross sea sectors. We find that our spatially extensive, mid-Holocene-to-present accumulation estimates are consistent with a sustained late-Holocene period of higher accumulation rates occurring over millennia reconstructed from the WAIS Divide ice core (WD14), thus indicating that this ice core is spatially representative

Published
2023

49. Selective digestive tract decontamination in critically ill adults with acute brain injuries: a post hoc analysis of a randomized clinical trial.

Author

Young, Paul J., Devaux, Anthony, Li, Qiang, Billot, Laurent, Davis, Joshua S., Delaney, Anthony, Finfer, Simon R., Hammond, Naomi E., Micallef, Sharon, Seppelt, Ian M., Venkatesh, Balasubramanian, Myburgh, John A., Gordon, Anthony, Cuthbertson, Brian, Fowler, Robert, Murthy, Srinivas, Pattison, Natalie, Iredell, Jon, Taylor, Colman, and Young, Duncan

Subjects
CRITICALLY ill patient care, HOSPITAL mortality, BRAIN injuries, CLINICAL trials, ALIMENTARY canal, CRITICALLY ill, CLUSTER randomized controlled trials
Abstract

Purpose: The aim of this study was to determine whether selective decontamination of the digestive tract (SDD) reduces in-hospital mortality in mechanically ventilated critically ill adults admitted to the intensive care unit (ICU) with acute brain injuries or conditions. Methods: We carried out a post hoc analysis from a crossover, cluster randomized clinical trial. ICUs were randomly assigned to adopt or not to adopt a SDD strategy for two alternating 12-month periods, separated by a 3-month inter-period gap. Patients in the SDD group (n = 2791; 968 admitted to the ICU with an acute brain injury) received a 6-hourly application of an oral paste and administration of a gastric suspension containing colistin, tobramycin, and nystatin for the duration of mechanical ventilation, plus a 4-day course of an intravenous antibiotic with a suitable antimicrobial spectrum. Patients in the control group (n = 3191; 1093 admitted to the ICU with an acute brain injury) received standard care. The primary outcome was in-hospital mortality within 90 days. There were four secondary clinical outcomes: death in ICU, ventilator-, ICU- and hospital-free days to day 90. Results: Of 2061 patients with acute brain injuries (mean age, 55.8 years; 36.4% women), all completed the trial. In patients with acute brain injuries, there were 313/968 (32.3%) and 415/1093 (38%) in-hospital deaths in the SDD and standard care groups (unadjusted odds ratio [OR], 0.76, 95% confidence interval [CI] 0.63–0.92; p = 0.004). The use of SDD was associated with statistically significant improvements in the four clinical secondary outcomes compared to standard care. There was no significant heterogeneity of treatment effect between patients with and without acute brain injuries (interaction p = 0.22). Conclusions: In this post hoc analysis of a randomized clinical trial in critically ill patients with acute brain injuries receiving mechanical ventilation, the use of SDD significantly reduced in-hospital mortality in patients compared to standard care without SDD. These findings require confirmation. [ABSTRACT FROM AUTHOR]

Published
2024
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