20 results on '"Pyle, A M"'
Search Results
2. Balanitis
- Author
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Pyle, Tia M., primary and Heymann, Warren R., additional
- Published
- 2018
- Full Text
- View/download PDF
3. List of Contributors
- Author
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Abdullah, Anthony, primary, Abrouk, Michael, additional, Ahad, Tashmeeta, additional, Ahmed, Imtiaz, additional, Al Hammadi, Anwar, additional, Allen, Caroline, additional, Almohssen, Amer Ali, additional, Alwan, Wisam, additional, Ameen, Mahreen, additional, Amini, Sadegh, additional, Anderson, Bryan E., additional, Anhalt, Grant J., additional, Baker, Donald J., additional, Bala, Harini Rajgopal, additional, Baltz, Julia, additional, Banach, David, additional, Banfield, Cedric C., additional, Baran, Robert, additional, Bardhan, Ajoy, additional, Barkham, Melissa C., additional, Bello, Ysabel M., additional, Benton, Emma, additional, Bergfeld, Wilma F., additional, Berkowitz, Eric, additional, Berman, Brian, additional, Bernhard, Jeffrey D., additional, Bernstein, Daniel, additional, Berth-Jones, John, additional, Bhate, Chinmoy, additional, Bhatia, Bhavnit K., additional, Blume, Jonathan E., additional, Bordet, Nevianna, additional, Borysiewicz, Catherine, additional, Brauner, Gary J., additional, Brodell, Robert T., additional, Brown, Marc D., additional, Burd, Robert M., additional, Burdick, Anne E., additional, Butala, Niraj, additional, Callen, Jeffrey P., additional, Camacho, Ivan D., additional, Camasmie, Helena, additional, Caplivski, Daniel, additional, Cappell, Mitchell S., additional, Casey, Genevieve A., additional, Chan, Lawrence S., additional, Chan, Loi-Yuen, additional, Chen, Jennifer K., additional, Chen, Chen “Mary”, additional, Chiang, Nicole Yi Zhen, additional, Chiaravalloti, Anthony J., additional, Child, Fiona J., additional, Chu, Anthony C., additional, Clayton, Timothy H., additional, Cohen, Steven R., additional, Cooper, Elizabeth A., additional, Cooper, Susan M., additional, Collier, Nick, additional, Correnti, Christina M., additional, Coulson, Ian H., additional, Council, M. Laurin, additional, Cowper, Shawn E., additional, Craven, Nicholas M., additional, Creamer, Daniel, additional, Cruz, Ponciano D., additional, Cusack, Carrie Ann R., additional, Daunton, Adam, additional, Davis, Mark D.P., additional, Dawe, Robert S., additional, D’Cruz, David P., additional, de Berker, David, additional, DeHoratius, Danielle M., additional, Deng, Min, additional, Desai, Seemal R., additional, Devlin, Georgina, additional, DiGiovanna, John J., additional, Doctoroff, Alexander, additional, Dodiuk-Gad, Roni P., additional, Eichenfield, Dawn Z., additional, Eichenfield, Lawrence F., additional, Eisen, Drore, additional, Eke, Ure, additional, Elston, Dirk M., additional, Emanuel, Patrick O.M., additional, Enos, Clinton W., additional, Ensanyat, Shaheen H., additional, Falabella, Anna F., additional, Farberg, Aaron S., additional, Feigenbaum, Lawrence S., additional, Fernandez, Kristen Heins, additional, Fett, Nicole, additional, Finlay, Andrew Y., additional, Firoz, Bahar F., additional, Firoz, Elnaz F., additional, Fitzpatrick, James E., additional, Flischel, Amy E., additional, Foley, Kelly A., additional, Freedman, Derek, additional, Fremlin, Georgina A., additional, Fried, Richard, additional, Friedlander, Philip, additional, Friedman, Adam, additional, Forrestel, Amy K., additional, Fuchs, Brian S., additional, Gach, Joanna E., additional, Galan, Anjela, additional, Ganesh, Jaya, additional, Garg, Amit, additional, Geller, Lauren, additional, Gelmetti, Carlo M., additional, Ghazi, Elizabeth, additional, Ghunawat, Sneha, additional, Goldberg, Leonard H., additional, Goodfield, Mark J.D., additional, Gordon, Marsha L., additional, Gowda, Asha, additional, Grabell, Daniel A., additional, Grant, Matthew, additional, Grattan, Clive E.H., additional, Greaves, Malcolm W., additional, Green, Justin J., additional, Griffiths, Christopher E.M., additional, Gropper, Charles A., additional, Grossberg, Anna L., additional, Gupta, Aditya K., additional, Hadi, Ali S., additional, Hadi, Suhail M., additional, Hagans, Iris A., additional, Hairston, Bethany R., additional, Halpern, Analisa Vincent, additional, Halverstam, Caroline, additional, Harper, Natasha, additional, Harries, Matthew J., additional, Harris, John, additional, Harrison, Shannon, additional, Hatch, Michael M., additional, Heagerty, Adrian H.M., additional, Hebert, Adelaide A., additional, Helms, Stephen E., additional, Hexsel, Camile L., additional, Hexsel, Doris M., additional, Heymann, Warren R., additional, Higgins, Elisabeth M., additional, Higgins, Claire L., additional, High, Whitney A., additional, Hönigsmann, Herbert, additional, Horenstein, Marcelo G., additional, Hruza, George J., additional, Hui, Andrea, additional, Huo, Ran, additional, Ibbotson, Sally H., additional, Ibrahim, Sherrif F., additional, Ilchyshyn, Andrew, additional, Ismail, Dina, additional, Jablonska, Stefania, additional, Jacobe, Heidi T., additional, James, William D., additional, Javed, Aysha, additional, Jemec, Gregor B.E., additional, Johnston, Graham A., additional, Jones, Stephen K., additional, Junkins-Hopkins, Jacqueline M., additional, Kaffenberger, Jessica, additional, Kane, Kelly R., additional, Kanelleas, Antonios, additional, Karadağ, Ayşe Serap, additional, Karas, Laura, additional, Katugampola, Ruwani P., additional, Katz, Bruce E., additional, Kellen, Roselyn, additional, Khan, Murtaza, additional, Khorasani, Hooman, additional, Kim, Ellen J., additional, Kim, Hee J., additional, Kirby, Brian, additional, Kirby, Joslyn S., additional, Klein, Rachel S., additional, Kleydman, Kate, additional, Koch, Dimitra, additional, Kohorst, John J., additional, Koo, John Y.M., additional, Kopp, Sandra A., additional, Korman, Neil J., additional, Kovarik, Carrie, additional, Kraemer, Kenneth H., additional, Krafchik, Bernice R., additional, Krishnamurthy, Karthik, additional, Kvernebo, Knut, additional, Lam, Charlene, additional, Lambert, Peter C., additional, Langtry, James A.A., additional, Larian, Amir A., additional, Larocca, Cecilia A., additional, Lawlor, E. Frances, additional, Lawrence, Clifford M., additional, Lebwohl, Mark G., additional, Lebwohl, Oscar, additional, Lehman, Julia S., additional, Leslie, Tabi A., additional, Lessin, Stuart R., additional, Levitt, Jacob O., additional, Lewis, Fiona M., additional, Liaqat, Maryam, additional, Liu, Kristina J., additional, Loosemore, Michael P., additional, Luger, Thomas A., additional, Lupi, Omar, additional, Lushniak, Boris D., additional, Lyon, Calum C., additional, Maderal, Andrea D., additional, Mahmoud, Bassel H., additional, Majewski, Slawomir, additional, Mallett, Richard B., additional, Manders, Steven M., additional, Mann, Ranon, additional, Mansouri, Yasaman, additional, Margolis, David J., additional, Markowitz, Orit, additional, Marsland, Alexander, additional, Martin-Clavijo, Agustin, additional, Martinez, Daniela, additional, Matiz, Catalina, additional, Maurer, Marcus, additional, McKerrow, Kevin, additional, Meah, Nekma, additional, Micali, Giuseppe, additional, Micheletti, Robert G., additional, Millard, Leslie G., additional, Miller, James E., additional, Wong Millsop, Jillian W., additional, Mimouni, Daniel, additional, Mirowski, Ginat W., additional, Mirza, Sultan A., additional, Molin, Sonja, additional, Morales-Burgos, Adisbeth, additional, Morison, Warwick L., additional, Mørk, Cato, additional, Morton, Colin A., additional, Motley, Richard J., additional, Mowbray, Megan, additional, Muldoon, Eavan G., additional, Muncaster, Anna E., additional, Murakawa, George J., additional, Murase, Jenny E., additional, Murdoch, Michele E., additional, Nabatian, Adam S., additional, Nakamura, Mio, additional, Nalluri, Rajani, additional, Nawas, Zeena Y., additional, Needham, Glen R., additional, Newell, Glenn C., additional, Newton-Bishop, Julia, additional, Nguyen, Adam V., additional, Nixon, Rosemary L., additional, O’Brien, Jack C., additional, Ogden, Stephanie, additional, Olbricht, Suzanne M., additional, O’Shea, Sally Jane, additional, Owen, Cindy E., additional, Pan, Michael, additional, Pappas-Taffer, Lisa, additional, Parish, Jennifer L., additional, Parish, Lawrence Charles, additional, Payette, Michael, additional, Peck, Gary L., additional, Pena, Sandra, additional, Peranteau, Jarad, additional, Pereira, Frederick A., additional, Perkins, William, additional, Perlis, Clifford S., additional, Phelps, Robert G., additional, Phillips, Tania J., additional, Poh-Fitzpatrick, Maureen B., additional, Pomeranz, Miriam Keltz, additional, Pop, Samantha R., additional, Porcu, Pierluigi, additional, Powell, James B., additional, Prok, Lori D., additional, Pyle, Tia M., additional, Qazaz, Surod, additional, Rajkomar, Vikram, additional, Rashid, Rabia S., additional, Rashighi, Mehdi, additional, Ratnavel, Ravi, additional, Regula, Christie G., additional, Renzi, Michael, additional, Revuz, Jean, additional, Reynolds, Rachel V., additional, Richard, Elisabeth, additional, Richard, Gabriele, additional, Rigel, Darrell S., additional, Robles, Wanda Sonia, additional, Rogge, Megan, additional, Rook, Alain H., additional, Manning, Jamie R., additional, Rosen, Ted, additional, Rosenbach, Misha, additional, Rosenfeld, David, additional, Rowland Payne, Christopher, additional, Rubin, Adam I., additional, Rubin, Courtney, additional, Rustin, Malcolm H.A., additional, Ruzicka, Thomas, additional, Samimi, Sara, additional, Schachner, Lawrence A., additional, Scheinfeld, Noah, additional, Schlosser, Bethanee J., additional, Schnur, Rhonda E., additional, Schwartz, Robert A., additional, Scorer, Matthew J., additional, Selkin, Bryan A., additional, Seymour, Jamie, additional, Shaver, Christine M., additional, Shea, Christopher R., additional, Shear, Neil H., additional, Shim, Tang Ngee, additional, Shimizu, Hiroshi, additional, Siegel, Julia, additional, Singer, Elisha, additional, Skelsey, Maral Kibarian, additional, Sladden, Chris, additional, Sladden, Michael, additional, Smith, Janellen, additional, Smucker, Joanne E., additional, Somani, Najwa, additional, Sommer, Lacy L., additional, Sommerlad, Mary, additional, Soon, Christine, additional, Sopkovich, Jennifer A., additional, Soter, Nicholas A., additional, Spencer, James M., additional, Staughton, Richard C.D., additional, Sterling, Jane C., additional, Sunderkötter, Cord, additional, Taibjee, Saleem M., additional, Tamura, Deborah, additional, Tan, Eunice, additional, Tang, William Y-M., additional, Taylor, Lynsey, additional, Thiers, Bruce H., additional, Thomas, Lucy J., additional, Thornton, Cody R., additional, Tobin, Anne-Marie, additional, Torgerson, Rochelle R., additional, Tosti, Antonella, additional, Tsatsou, Fragkiski, additional, Tsuji-Abe, Yukiko, additional, Tucker, William F.G., additional, Tyring, Stephen K., additional, Udkoff, Jeremy, additional, Unger, Robin H., additional, Unger, Walter P., additional, Utz, Sarah, additional, Valbuena, Martha C., additional, van de Kerkhof, Peter, additional, Van Voorhees, Abby S., additional, Vangipuram, Ramya, additional, Veitch, David, additional, Venning, Vanessa, additional, Versteeg, Sarah G., additional, Viera, Martha, additional, Vittorio, Carmela C., additional, Vleugels, Ruth Ann, additional, Wali, Gorav N., additional, Wallengren, Joanna, additional, Wan, Joy, additional, Wanat, Karolyn A., additional, Weichert, Gabriele, additional, Weidmann, Anja K., additional, Weinberg, Jeffrey M., additional, Werth, Victoria P., additional, White, Lucile E., additional, Wiener, Adam H., additional, Wilkin, Jonathan K., additional, Wilkin, Nathaniel K., additional, Williams, Jason, additional, Wilson, Niall, additional, Wiss, Karen, additional, Witkowski, Joseph A., additional, Wiznia, Lauren E., additional, Wong, Henry K., additional, Wong, Junie Li Chun, additional, Wright, Andrew L., additional, Wriston, Cooper C., additional, Wu, Benedict C., additional, Wulkan, Adam, additional, Zaenglein, Andrea L., additional, Zaki, Irshad, additional, Zeichner, Joshua A., additional, Zhu, Tian Hao, additional, Zone, John J., additional, Zouboulis, Christos C., additional, and Zuberbeir, Torstein, additional
- Published
- 2018
- Full Text
- View/download PDF
4. Contributors
- Author
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Acocella, Valerio, primary, Andrews, Graham D.M., additional, Andrews, Benjamin, additional, Angelis, Silvio De, additional, Arnórsson, Stefán, additional, Aspinall, Willy, additional, Aubele, Jayne C., additional, Barclay, Jenni, additional, Baxter, Peter J., additional, Bebbington, Mark, additional, Belousov, Alexander, additional, Bernard, Alain, additional, Bernstein, Marc, additional, Bleacher, Jacob Elvin, additional, Blong, Russell, additional, Bonadonna, Costanza, additional, Branney, Michael, additional, Brown, Richard J., additional, Browne, Brandon, additional, Burgisser, Alain, additional, Bursik, Marcus, additional, Büttner, Ralf, additional, Calder, Eliza S., additional, Carey, Steven, additional, Carey, Rebecca J., additional, Carn, Simon A., additional, Cas, Ray, additional, Cashman, Katharine V., additional, Chiodini, Giovanni, additional, Cioni, Raffaello, additional, Clarke, Amanda Bachtell, additional, Clarkson, Bruce D., additional, Coffin, Millard F., additional, Cole, Paul D., additional, Connor, Chuck, additional, Connor, Charles B., additional, Cornelis, Jean-Thomas, additional, Costa, Antonio, additional, Cottrell, Elizabeth, additional, Crisafulli, Charles M., additional, Crown, David A., additional, Crumpler, Larry S., additional, Daines, Martha J., additional, Davies, Tim, additional, Day, Simon J., additional, Degruyter, Wim, additional, Dehn, Jonathan, additional, de la Cruz, Servando, additional, Deligne, Natalia Irma, additional, Dellino, Pierfrancesco, additional, Delmelle, Pierre, additional, de Ronde, Cornel E.J., additional, de Silva, Shan, additional, Dufek, Josef, additional, Edmonds, Marie, additional, Edwards, Benjamin R., additional, Erfurt-Cooper, Patricia, additional, Esposti Ongaro, Tomaso, additional, Ewert, John W., additional, Fee, David, additional, Fischer, Tobias P., additional, Folch, Arnau, additional, Freymueller, Jeffrey T., additional, Garry, William Brent, additional, Geissler, Paul, additional, Ghiorso, Mark S., additional, Goff, Fraser, additional, Goff, Cathy J., additional, Gonnermann, Helge, additional, Gregg, Chris E., additional, Grove, Timothy L., additional, Gualda, Guilherme A.R., additional, Gudmundsson, Magnús T., additional, Halvorson, Jonathan J., additional, Harris, Andrew J.L., additional, Hauri, Erik H., additional, Haynes, Katharine, additional, Head, James W., additional, Henley, Richard W., additional, Horwell, Claire J., additional, Houghton, Bruce, additional, Ian Schipper, C., additional, Ivanov, Mikhail A., additional, Iverson, Richard M., additional, James, Michael R., additional, Johnson, Jeffrey, additional, Johnston, David, additional, Jolly, Gill, additional, Kano, Kazuhiko, additional, Kendrick, Jackie E., additional, Kilburn, Christopher R.J., additional, Koppers, Anthony A.P., additional, Koyaguchi, Takehiro, additional, LaFemina, Peter C., additional, Lavallée, Yan, additional, Lesher, Charles E., additional, Lindsay, Jan M., additional, Locke, Corinne A., additional, Lopes, Rosaly M.C., additional, Marsh, Bruce D., additional, Marzocchi, Warner, additional, Maters, Elena, additional, McNutt, Stephen R., additional, McPhie, Jocelyn, additional, Murray, John B., additional, Neri, Augusto, additional, Opfergelt, Sophie, additional, Oppenheimer, Clive, additional, Pallister, John, additional, Pec, Matej, additional, Ping, Chien-Lu, additional, Pistolesi, Marco, additional, Plank, Terry, additional, Prata, Fred, additional, Pyle, David M., additional, Rampino, Michael R., additional, Robock, Alan, additional, Roche, Olivier, additional, Rogers, Nick, additional, Roman, Diana C., additional, Rose, Bill, additional, Rosi, Mauro, additional, Rowland, Scott K., additional, Russell, James K., additional, Rymer, Hazel, additional, Scheu, Bettina, additional, Self, Stephen, additional, Sheets, Payson, additional, Siebert, Lee, additional, Sigurdsson, Haraldur, additional, Soule, S. Adam, additional, Spera, Frank J., additional, Spudis, Paul D., additional, Staudigel, Hubert, additional, Stefánsson, Andri, additional, Stimac, James, additional, Stucker, Valerie K., additional, Swanson, Frederick J., additional, Szramek, Lindsay, additional, Taddeucci, Jacopo, additional, Taisne, Benoit, additional, Thomas, Ronald J., additional, Thompson, Glenn, additional, Thórhallsson, Sverrir, additional, Till, Christy B., additional, Valentine, Greg A., additional, Vallance, James W., additional, Van Eaton, Alexa R., additional, van Wyk de Vries, Benjamin, additional, Venzke, Edward, additional, Vergniolle, Sylvie, additional, Wallace, Paul J., additional, White, James D.L., additional, Williams-Jones, Glyn, additional, Williams, David A., additional, Wilson, Lionel, additional, Wohletz, Kenneth H., additional, Wolff, John A., additional, Zimanowski, Bernd, additional, and Zimbelman, James R., additional
- Published
- 2015
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5. Sizes of Volcanic Eruptions
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Pyle, David M., primary
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- 2015
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6. Preparation and electroporation of Cas12a/Cpf1-guide RNA complexes for introducing large gene deletions in mouse embryonic stem cells
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Pyle, A M, Christianson, D W, Pyle, A M ( A M ), Christianson, D W ( D W ), Kissling, Lucas, Monfort, Asun, Swarts, Daan C, Wutz, Anton, Jinek, Martin, Pyle, A M, Christianson, D W, Pyle, A M ( A M ), Christianson, D W ( D W ), Kissling, Lucas, Monfort, Asun, Swarts, Daan C, Wutz, Anton, and Jinek, Martin
- Abstract
CRISPR-Cas12a is a bacterial RNA-guided deoxyribonuclease that has been adopted for genetic engineering in a broad variety of organisms. Here, we describe protocols for the preparation and application of AsCas12a-guide RNA ribonucleoprotein (RNP) complexes for engineering gene deletions in mouse embryonic stem (ES) cells. We provide detailed protocols for purification of an NLS-containing AsCas12a-eGFP fusion protein, design of guide RNAs, assembly of RNP complexes, and transfection of mouse ES cells by electroporation. In addition, we present data illustrating the use of pairs of Cas12a nucleases for engineering large genetic deletions and outline experimental considerations for applications of Cas12a nucleases in ES cells.
- Published
- 2019
7. New constraints from Central Chile on the origins of enriched continental compositions in thick-crusted arc magmas
- Author
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Wieser, P. E., Turner, S. J., Mather, T. A., Pyle, D. M., Savov, I. P., Orozco, G., Wieser, P. E., Turner, S. J., Mather, T. A., Pyle, D. M., Savov, I. P., and Orozco, G.
- Abstract
Magmas from continental arcs built on thick crust have elevated incompatible element abundances and “enriched” radiogenic isotope ratios compared to magmas erupted in island and continental arcs overlying thinner crust. The relative influence of the slab, mantle, and upper plate on this variability is heavily debated. The Andean Southern Volcanic Zone (SVZ; 33-46° S) is an ideal setting to investigate the production of enriched continental arc compositions, because both crustal thickness and magma chemistry vary coherently along strike. However, the scarcity of primitive magmas in the thick-crusted northern SVZ has hindered previous regional studies. To better address the origin of enriched continental compositions, we investigate the geochemistry (major and trace element abundances, 87Sr/86Sr and 143Nd/144Nd ratios) of new mafic samples from Don Casimiro and Maipo volcanoes in Diamante-Maipo Caldera Complex of the northern SVZ. While evolved Diamante-Maipo samples show evidence for crustal assimilation, the trace element and isotopic enrichment of the most mafic samples cannot result from crustal processing, as no known regional or global basement lithologies are enriched in all of the necessary incompatible trace elements. Subduction erosion models similarly fail to account for the enriched isotopic and trace element signature of these samples. Instead, we suggest that the enrichment of northern SVZ magmas is derived from an enriched ambient mantle component (similar to EM1-type ocean island basalts), superimposed on a northward decline in melt extent. A substantial, but nearly uniform contribution of melts from subducting sediment and altered oceanic crust are required at all latitudes. The EM1-like enrichment may arise from recycling of metasomatized subcontinental lithospheric mantle (M-SCLM), as the isotopic trajectory of primitive rear-arc monogenetic cones trend towards the compositions of SCLM melts sampled across South America. Isotopic data from spatially
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- 2019
- Full Text
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8. Oceanic fronts control the distribution of dissolved barium in the Southern Ocean
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Pyle, Kimberley M., Hendry, Katharine R., Sherrell, Robert M., Legge, Oliver, Hind, Andrew J., Bakker, Dorothee, Venables, Hugh, Meredith, Michael P., Pyle, Kimberley M., Hendry, Katharine R., Sherrell, Robert M., Legge, Oliver, Hind, Andrew J., Bakker, Dorothee, Venables, Hugh, and Meredith, Michael P.
- Abstract
The globally-observed relationship between oceanic barium and the macronutrient silicic acid results from the shared influence of large-scale ocean circulation and mixing on the two elements, and the inherent link between barium and organic matter formation and dissolution. A detailed examination of deviations from barium-silicon correlations can reveal variations in non-conservative processes within the marine barium cycle. Here, we present a high-resolution dataset of dissolved barium and macronutrients from the Drake Passage and the Scotia and Weddell Seas. Our new results highlight the influence of Southern Ocean frontal zones on barium cycling and the deviations of barium and macronutrient distributions as a result of spatial variations in phytoplankton assemblages and in barite formation processes. These new data also reinforce findings that water mass mixing and ocean circulation, in particular the location of oxygen minima, play a key role in barium distribution. Our findings have implications for the use of sedimentary barium as a proxy for export production, which may be complicated by physical water circulation changes or shifts in plankton community structure.
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- 2018
9. The evolution of magma during continental rifting: new constraints from the isotopic and trace element signatures of silicic magmas from Ethiopian volcanoes
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Hutchison, William, Mather, Tamsin A., Pyle, David M., Boyce, Adrian J., Gleeson, Matthew L.M., Yirgu, Gezahegn, Blundy, Jon D., Ferguson, David J., Vye-Brown, Charlotte, Millar, Ian L., Sims, Kenneth W.W., Finch, Adrian A., Hutchison, William, Mather, Tamsin A., Pyle, David M., Boyce, Adrian J., Gleeson, Matthew L.M., Yirgu, Gezahegn, Blundy, Jon D., Ferguson, David J., Vye-Brown, Charlotte, Millar, Ian L., Sims, Kenneth W.W., and Finch, Adrian A.
- Abstract
Magma plays a vital role in the break-up of continental lithosphere. However, significant uncertainty remains about how magma-crust interactions and melt evolution vary during the development of a rift system. Ethiopia captures the transition from continental rifting to incipient sea-floor spreading and has witnessed the eruption of large volumes of silicic volcanic rocks across the region over ∼45 Ma. The petrogenesis of these silicic rocks sheds light on the role of magmatism in rift development, by providing information on crustal interactions, melt fluxes and magmatic differentiation. We report new trace element and Sr–Nd–O isotopic data for volcanic rocks, glasses and minerals along and across active segments of the Main Ethiopian (MER) and Afar Rifts. Most data for mineral and glass separates from these active rift zones fall within the bounds of modelled fractional crystallization trajectories from basaltic parent magmas (i.e., 5.5–6.5‰) with scant evidence for assimilation of Pan-African Precambrian crustal material ( of 7–18‰). Radiogenic isotopes (; 87Sr/86Sr = 0.7037–0.7072) and incompatible trace element ratios (Rb/Nb <1.5) are consistent with data and emphasize limited interaction with Pan-African crust. However, there are important regional variations in melt evolution revealed by incompatible elements (e.g., Th and Zr) and peralkalinity (molar ). The most chemically-evolved peralkaline compositions are associated with the MER volcanoes (Aluto, Gedemsa and Kone) and an off-axis volcano of the Afar Rift (Badi). On-axis silicic volcanoes of the Afar Rift (e.g., Dabbahu) generate less-evolved melts. While at Erta Ale, the most mature rift setting, peralkaline magmas are rare. We find that melt evolution is enhanced in less mature continental rifts (where parental magmas are of transitional rather than tholeiitic composition) and regions of low magma flux (due to reduced mantle melt productivity or where crustal structure inhibits magma ascent). This has i
- Published
- 2018
10. Compositional variability in mafic arc magmas over short spatial and temporal scales: Evidence for the signature of mantle reactive melt channels
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Rawson, Harriet, Keller, Tobias, Fontijn, Karen, Pyle, David M., Mather, Tamsin A., Smith, Victoria C., and Naranjo, José A.
- Subjects
reactive melt channels ,Geophysics ,Space and Planetary Science ,Geochemistry and Petrology ,Mocho-Choshuenco ,Géochimie ,Southern Volcanic Zone ,subduction zone processes ,Earth and Planetary Sciences (miscellaneous) ,mantle transport ,Volcanologie ,Géodynamique et tectonique - Abstract
Understanding arc magma genesis is critical to deciphering the construction of continental crust, understanding the relationship between plutonic and volcanic rocks, and for assessing volcanic hazards. Arc magma genesis is complex. Interpreting the underlying causes of major and trace element diversity in erupted magmas is challenging and often non-unique. To navigate this complexity mafic magma diversity is investigated using sample suites that span short temporal and spatial scales. These constraints allow us to evaluate models of arc magma genesis and their geochemical implications based on physical arguments and recent model results. Young volcanic deposits (≲18 kyr) are analysed from the Southern Volcanic Zone (SVZ), Chile, in particular suites of scoria cones on the flanks of arc stratovolcanoes that have erupted relatively primitive magmas of diverse compositions. Our study is centred on the high-resolution post-glacial tephrochronological record for Mocho-Choshuenco volcano where tight age constraints and a high density of scoria cones provide a spatially well-resolved mafic magma dataset. Two compositional trends emerge from the data. Firstly, magmas from cones on the flanks of the main edifice become more mafic with distance from the central vent. This is attributed to fractional crystallisation processes within the crust, with distal cones sampling less differentiated magmas. Secondly, there is a set of cones with distinct major and trace element compositions that are more primitive but enriched in incompatible elements relative to the central system and other ‘normal SVZ’ magmas. This distinct signature – termed the ‘Kangechi’ signature – is observed at three further clusters of cones within the SVZ. This is attributed to greater preservation of the enriched melt signature arising from reactive melt transport within the mantle wedge. Our model has important implications for arc magma genesis in general, and in particular for the spatial and temporal scales over which compositional variations are preserved in erupted magmas.
- Published
- 2016
11. Glaciovolcanism at Volcán Sollipulli, southern Chile: lithofacies analysis and interpretation
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Lachowycz, Stefan M., Pyle, David M., Gilbert, Jennie S., Mather, Tamsin A., Mee, Katy, Naranjo, José A., Hobbs, Laura K., Lachowycz, Stefan M., Pyle, David M., Gilbert, Jennie S., Mather, Tamsin A., Mee, Katy, Naranjo, José A., and Hobbs, Laura K.
- Abstract
Magma–ice–meltwater interactions produce diverse landforms and lithofacies, reflecting the multitude of factors that influence glaciovolcanism, including both magmatic (e.g., composition, eruption rate) and glacial (e.g., ice thickness, thermal regime) conditions. This is exemplified by the walls of the partly ice-filled summit caldera of Volcán Sollipulli, a stratovolcano in southern Chile, which include lithofacies from eruptions of a wide range of magma compositions beneath or in contact with ice. Here we analyse these lithofacies and hence propose new interpretations of the eruptive and glacial history of Sollipulli. The facies include a thick, laterally extensive sequence of fragmental glaciovolcanic deposits, comprising massive, mafic lava pillow-bearing hyaloclastite overlain by sills and then hyaloclastic debris flow deposits (similar to Dalsheidi-type sequences). The distribution and thickness of these units indicate an unusual abundance of magma–meltwater interaction for an arc stratovolcano in temperate latitudes, perhaps due to eruptions beneath a thick ice cap. Coherent lava coulées, domes, lobes, and stacks of basaltic andesite–trachydacite composition are present around the top of the caldera rim; these display morphologies and fracture patterns on caldera-facing margins that indicate that the caldera was filled with ice when these lavas were erupted. The lithofacies characterised in this study demonstrate the diversity of glaciovolcanism that is possible at arc stratovolcanoes capped by temperate ice or with ice-filled calderas, and the potential for uncertainties in inference of the palaeoenvironmental conditions of their emplacement.
- Published
- 2015
12. EFFECTS OF IN VIVO DIALYZABLE LEUKOCYTE LYSATE TREATMENT ON THE DEVELOPMENT OF ALLOGENEIC CELL-MEDIATED CYTOTOXICITY
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Pyle, Joseph M., primary and Baram, Peter, additional
- Published
- 1979
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13. The volcanic response to deglaciation: Evidence from glaciated arcs and a reassessment of global eruption records
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Watt, Sebastian F. L., Pyle, David M., Mather, Tamsin A., Watt, Sebastian F. L., Pyle, David M., and Mather, Tamsin A.
- Abstract
Several lines of evidence have previously been used to suggest that ice retreat after the last glacial maximum (LGM) resulted in regionally-increased levels of volcanic activity. It has been proposed that this increase in volcanism was globally significant, forming a substantial component of the post-glacial rise in atmospheric CO2, and thereby contributing to climatic warming. However, as yet there has been no detailed investigation of activity in glaciated volcanic arcs following the LGM. Arc volcanism accounts for 90% of present-day subaerial volcanic eruptions. It is therefore important to constrain the impact of deglaciation on arc volcanoes, to understand fully the nature and magnitude of global-scale relationships between volcanism and glaciation. The first part of this paper examines the post-glacial explosive eruption history of the Andean southern volcanic zone (SVZ), a typical arc system, with additional data from the Kamchatka and Cascade arcs. In all cases, eruption rates in the early post-glacial period do not exceed those at later times at a statistically significant level. In part, the recognition and quantification of what may be small (i.e. less than a factor of two) increases in eruption rate is hindered by the size of our datasets. These datasets are limited to eruptions larger than 0.1 km3, because deviations from power-law magnitude–frequency relationships indicate strong relative under-sampling at smaller eruption volumes. In the southern SVZ, where ice unloading was greatest, eruption frequency in the early post-glacial period is approximately twice that of the mid post-glacial period (although frequency increases again in the late post-glacial). A comparable pattern occurs in Kamchatka, but is not observed in the Cascade arc. The early post-glacial period also coincides with a small number of very large explosive eruptions from the most active volcanoes in the southern and central SVZ, consistent with enhanced ponding of magma during glaciat
- Published
- 2013
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14. Guiding ribozyme cleavage through motif recognition: the mechanism of cleavage site selection by a group ii intron ribozyme.
- Author
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Su LJ, Qin PZ, Michels WJ, and Pyle AM
- Subjects
- Base Pair Mismatch, Base Pairing, Base Sequence, Binding Sites, Cations, Divalent metabolism, Exons genetics, Kinetics, Models, Genetic, Mutation genetics, RNA Precursors chemistry, RNA Precursors genetics, RNA, Catalytic classification, Single-Strand Specific DNA and RNA Endonucleases metabolism, Substrate Specificity, Thermodynamics, Introns genetics, RNA Precursors metabolism, RNA, Catalytic genetics, RNA, Catalytic metabolism
- Abstract
The mechanism by which group II introns cleave the correct phosphodiester linkage was investigated by studying the reaction of mutant substrates with a ribozyme derived from intron ai5gamma. While fidelity was found to be quite high in most cases, a single mutation on the substrate (+1C) resulted in a dramatic loss of fidelity. When this mutation was combined with a second mutation that induces a bulge in the exon binding site 1/intron binding site 1 (EBS1/IBS1) duplex, the base-pairing register of the EBS1/IBS1 duplex was shifted and the cleavage site moved to a downstream position on the substrate. Conversely, when mismatches were incorporated at the EBS1/IBS1 terminus, the duplex was effectively truncated and cleavage occurred at an upstream site. Taken together, these data demonstrate that the cleavage site of a group II intron ribozyme can be tuned at will by manipulating the thermodynamic stability and structure of the EBS1/IBS1 pairing. The results are consistent with a model in which the cleavage site is not designated through recognition of specific nucleotides (such as the 5'-terminal residue of EBS1). Instead, the ribozyme detects a structure at the junction between single and double-stranded residues on the bound substrate. This finding explains the puzzling lack of phylogenetic conservation in ribozyme and substrate sequences near group II intron target sites., (Copyright 2001 Academic Press.)
- Published
- 2001
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15. Antagonistic substrate binding by a group II intron ribozyme.
- Author
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Qin PZ and Pyle AM
- Subjects
- Binding Sites, Catalysis, Mutation, Nucleic Acid Conformation, RNA Splicing, RNA, Catalytic antagonists & inhibitors, RNA, Catalytic chemistry, Substrate Specificity, Thermodynamics, Introns, RNA, Catalytic metabolism
- Abstract
In this study, the thermodynamic properties of substrate-ribozyme recognition were explored using a system derived from group II intron ai5gamma. Substrate recognition by group II intron ribozymes is of interest because any nucleic ac?id sequence can be targeted, the recognition sequence can be quite long (>/=13 bp), and reaction can proceed with a very high degree of sequence specificity. Group II introns target their substrates throug?h the formation of base-pairing interactions with two regions of the intron (EBS1 and EBS2), which are usually located far apart in the secondary structure. These structures pair with adjacent, corresponding sites (IBS1 and IBS2) on the substrate. In order to understand the relative energetic contribution of each base-pairing interaction (EBS1-IBS1 or EBS2-IBS2) to substrate binding energy, the free energy of each helix was measured. The individual helices were found to have base-pairing free energies similar to those calculated for regular RNA duplexes of the same sequence, suggesting that each recognition helix derives its binding energy from base-pairing interactions alone and that each helix can form independently. Most interestingly, it was found that the sum of the measured individual free energies (approximately 20 kcal/mol) was much higher than the known free energy for substrate binding (approximately 12 kcal/mol). This indicates that certain group II intron ribozymes can bind their substrates in an antagonistic fashion, paying a net energetic penalty upon binding the full-length substrate. This loss of binding energy is not due to weakening of individual helices, but appears to be linked to ribozyme conformational changes induced by substrate binding. This coupling between substrate binding and ribozyme conformational rearrangement may provide a mechanism for lowering overall substrate binding energy while retaining the full information content of 13 bp, thus resulting in a mechanism for ensuring sequence specificity., (Copyright 1999 Academic Press.)
- Published
- 1999
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16. Stepping through an RNA structure: A novel approach to conformational analysis.
- Author
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Duarte CM and Pyle AM
- Subjects
- Algorithms, Computer Simulation, Databases, Factual, Nucleotides chemistry, RNA, Transfer, Phe chemistry, Software, Models, Molecular, Nucleic Acid Conformation, RNA chemistry
- Abstract
Drawing from the growing database of complex three-dimensional RNA structures, a systematic method has been developed for classifying and analyzing the variety of conformations adopted by nucleic acids. This method is based on the development of a reduced representation for nucleic acid backbone conformation, simplifying the formidable eight-dimensional problem that has long complicated nucleic acid conformational analysis. Two pseudotorsion angles (eta and theta) have been defined, based on the selection of two appropriate pivot points along the RNA backbone, P and C4'. These pseudotorsions, together with a complete library of conventional torsion angles, can be calculated for any RNA structure or all-atom model using a new program called AMIGOS. Having computed eta and theta pseudotorsions for each position on an RNA molecule, they can be represented on a two-dimensional plot similar to the phi-phi plots that have traditionally been used for protein conformational analysis. Like a Ramachandran plot, clusters of residues appear at discrete regions on an eta-theta plot. Nucleotides within these clusters share conformational properties, often belonging to the same type of structural motif such as A-platforms, sheared tandem purine-purine pairs and GNRA tetraloops. An eta-theta plot provides a two-dimensional representation of the conformational properties of an entire RNA molecule, facilitating rapid analysis of structural features. In addition to the utility of eta-theta plots for intuitive visualization of conformational space, the pseudotorsional convention described here should significantly simplify approaches to macromolecular modeling of RNA structure., (Copyright 1998 Academic Press)
- Published
- 1998
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17. Branch-site selection in a group II intron mediated by active recognition of the adenine amino group and steric exclusion of non-adenine functionalities.
- Author
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Liu Q, Green JB, Khodadadi A, Haeberli P, Beigelman L, and Pyle AM
- Subjects
- Binding Sites, Mutagenesis, Site-Directed, RNA Processing, Post-Transcriptional, RNA Splicing, RNA, Catalytic metabolism, Spliceosomes metabolism, Adenine chemistry, Introns, RNA, Catalytic chemistry
- Abstract
The 2'-hydroxyl on a specific bulged adenosine is the nucleophile during the first step of splicing by group II introns. To understand the means by which the ribozyme core recognizes this adenosine, it was mutagenized and effects on catalytic activity were quantified. The results indicate that a low level of mutational variability is tolerated at the branch-site of group II introns, with no apparent loss of fidelity. Analyses of mutant and modified nucleotides at the branch-site reveal that adenine is recognized primarily through the N6 amino group and by steric exclusion of functionalities found on other bases. The mutational and single atom effects reported here contrast with those observed during spliceosomal processing, suggesting that there are important differences in adenosine recognition by the two systems.
- Published
- 1997
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18. Remarkable morphological variability of a common RNA folding motif: the GNRA tetraloop-receptor interaction.
- Author
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Abramovitz DL and Pyle AM
- Subjects
- Kinetics, RNA genetics, Sequence Analysis, Nucleic Acid Conformation, RNA chemistry
- Abstract
One of the most common RNA tertiary interactions involves the docking of GNRA hairpin loops into stem-loop structures on other regions of RNA. Domain 5 of the group II intron interacts with Domain 1 through such an interaction, which has been characterized thermodynamically and kinetically for the ai5g intron. Using this system, it was possible to test the morphological tolerances of the GNRA tetraloop involved in tertiary interactions. The data presented herein show that a GNRA tetraloop can still participate in tertiary interaction after being physically cut at any phosphodiester linkage within the loop. The "nicked tetraloop" can be expanded by many nucleotides in either direction and the covalently continuous loop can also be expanded without loss of interaction energy. In the context of the nicked tetraloop, the second nucleotide of the tetraloop sequence can be completely deleted without loss of function. By examining radical alterations in tetraloop structure, this study helps define the minimal sequence and structural requirements of a GNRA motif involved in long-range tertiary interaction. It shows that "tetraloop"-like structures capable of forming tertiary interactions can be imbedded in unexpected contexts, such as internal loops and apparently open structure within RNA. It demonstrates that pentaloops and hexaloops can form the same type of interaction, with almost equal affinity, as a tetraloop. Taken together, these data suggest a more generic term for the GNRA tetraloop-receptor interaction: It is proposed herein that the term "GNRA tetraloop" be replaced by "GNn/RA", where n represents a variable number of nucleotides and / indicates that the loop can be divided and interrupted by other sequences.
- Published
- 1997
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19. Two competing pathways for self-splicing by group II introns: a quantitative analysis of in vitro reaction rates and products.
- Author
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Daniels DL, Michels WJ Jr, and Pyle AM
- Subjects
- Ammonium Chloride, Ammonium Sulfate, Hydrolysis, Kinetics, Magnesium Chloride, Models, Biological, Nucleic Acid Conformation, Osmolar Concentration, Potassium Chloride, RNA, Fungal chemistry, RNA, Fungal genetics, RNA, Fungal metabolism, Ribonucleases, Saccharomyces cerevisiae genetics, Saccharomyces cerevisiae metabolism, Introns, RNA Splicing
- Abstract
Self-splicing group II introns are found in bacteria and in the organellar genes in plants, fungi, and yeast. The mechanism for the first step of splicing is generally believed to involve attack of a specific intronic 2'-hydroxyl group on a phosphodiester linkage at the 5'-splice site, resulting in the formation of a lariat intron species. In this paper, we present kinetic and enzymatic evidence that in vitro there are two distinct pathways for group II intron self-splicing: one involves 2'-OH attack and another involves attack of water or hydroxide. These two pathways occur in parallel under all reaction conditions, although either can dominate in the presence of particular salts or protein cofactors. Both pathways are followed by a successful second step of splicing, and either pathway can be highly efficient. We find that the hydrolytic pathway prevails under physiological ionic conditions, while branching predominates at molar concentrations of ammonium ion. The intron is observed to adopt two major active conformations. In order to quantify their individual reaction rates, we applied a mechanistic model describing biphasic parallel kinetic behavior. Kinetic analysis throughout the investigation reveals that there is no coupling between the unproductive "spliced-exon-reopening" reaction (SER) and hydrolysis during the first step of splicing. Conditions that stimulate branching can promote the SER reaction just as efficiently as conditions that stimulate the hydrolytic pathway. Although there is little evidence that it exists in vivo, a hydrolytic splicing pathway for group II introns has important implications for the translation of intron-encoded proteins and the inhibition of intron migration into new genomic positions.
- Published
- 1996
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20. Group II intron ribozymes that cleave DNA and RNA linkages with similar efficiency, and lack contacts with substrate 2'-hydroxyl groups.
- Author
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Griffin EA Jr, Qin Z, Michels WJ Jr, and Pyle AM
- Subjects
- Animals, DNA chemistry, Hydroxylation, Kinetics, Nucleotide Mapping, Plasmids genetics, RNA chemistry, RNA Splicing, RNA, Bacterial metabolism, RNA, Catalytic chemistry, RNA, Messenger chemistry, RNA, Messenger metabolism, Tetrahymena metabolism, DNA metabolism, Introns genetics, RNA metabolism, RNA, Catalytic metabolism
- Abstract
Background: Group II introns are self-splicing RNAs that have mechanistic similarity to the spliceosome complex involved in messenger RNA splicing in eukaryotes. These autocatalytic molecules can be reconfigured into highly specific, multiple-turnover ribozymes that cleave oligonucleotides in trans. We set out to use a simplified system of this kind to study the mechanism of cleavage., Results: Unlike other catalytic RNA molecules, the group II ribozymes cleave DNA linkages almost as readily as RNA linkages. One ribozyme variant cleaves DNA linkages with an efficiency comparable to that of restriction endonuclease EcoRI. Single deoxynucleotide substitutions in the substrate showed that the ribozymes bind substrate without engaging 2'-hydroxyl groups., Conclusions: The ribose 2'-hydroxyl group at the cleavage site has little role in transition-state stabilization by group II ribozymes. Substrate 2'-hydroxyl groups are not involved in substrate binding, suggesting that only base-pairing is required for substrate recognition.
- Published
- 1995
- Full Text
- View/download PDF
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