18 results
Reconstructing Saharan dust transport to the Eastern Mediterranean Sea during the last 180 ka using endmember modelling of grain size data
- Sarah Beuscher, Werner Ehrmann, Stefan Krüger, Gerhard Schmiedl
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- Journal:
- Quaternary Research / Volume 94 / March 2020
- Published online by Cambridge University Press:
- 06 January 2020, pp. 156-173
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Endmember modelling on the terrigenous silt fraction of nine marine sediment cores spanning up to 180,000 years reveals the influx of North African dust into the Eastern Mediterranean Sea. The dust grain size modes decrease with transport distance, from >50 µm off the African coast to ca. 30 µm in the Aegean Sea. The dust signal is strongly influenced by hydrological changes in northern Africa. Changes from arid to humid periods are documented in the grain size data of all cores. The climatic signal gets weaker with growing distance from the source and close to large fluvial sediment sources such as the Nile. Frequency and wavelet analyses show a strong orbital precession signal that is known to trigger the migration of the monsoonal rain belt in northern Africa. The influence of climate changes on suborbital time scales on dust influx is less distinct, but Dansgaard-Oeschger interstadials and Heinrich-like events are documented in some cores. In the sediment core closest to the source, three endmembers represent one or more dust sources in northern Africa. With growing distance from the source, the three modes cannot be separated anymore and appear as one multimodal dust endmember.
Measurement of mechanical properties of snow for simulation of skiing
- Martin Mössner, Gerhard Innerhofer, Kurt Schindelwig, Peter Kaps, Herwig Schretter, Werner Nachbauer
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- Journal:
- Journal of Glaciology / Volume 59 / Issue 218 / 2013
- Published online by Cambridge University Press:
- 10 July 2017, pp. 1170-1178
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In the simulation of skiing the force between ski and snow is a decisive factor. We decompose the reaction force into a penetration force normal to the snow surface, a shear force and friction. Two portable measurement devices were developed to study the penetration and shear forces for compacted snow on groomed ski slopes. The penetration force was assessed by measuring the penetration depth of a ski-tool loaded normal to the snow surface. For the shear force the tangential load was measured when the snow began to fail. Overall 236 penetration and 108 shear experiments were conducted on different types of snow. The penetration force was proportional to the volume of snow displaced by the ski-tool. The failure shear force was proportional to the penetration depth multiplied by the length of the tool. The constants of proportionality, HV and Sf, are material parameters of snow. The snow hardness, HV, varied between 0.04 and 90 N mm–3 and the failure shear stress, Sf, between 0.04 and 0.40 N mm–2. In another investigation, skiing turns were simulated using the presented snow reaction forces. Maximum deviations between computed and real trajectories were <1 % of the overall length of the runs.
Modern and late Quaternary clay mineral distribution in the area of the SE Mediterranean Sea
- Yvonne Hamann, Werner Ehrmann, Gerhard Schmiedl, Tanja Kuhnt
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- Journal:
- Quaternary Research / Volume 71 / Issue 3 / May 2009
- Published online by Cambridge University Press:
- 20 January 2017, pp. 453-464
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The present-day clay mineral distribution in the southeastern Levantine Sea and its borderlands reveals a complex pattern of different sources and distribution paths. Smectite dominates the suspended load of the Nile River and of rivers in the Near East. Illite sources are dust-bearing winds from the Sahara and southwestern Europe. Kaolinite is prevalent in rivers of the Sinai, in Egyptian wadis, and in Saharan dust. A high-resolution sediment core from the southeastern Levantine Sea spanning the last 27 ka shows that all these sources contributed during the late Quaternary and that the Nile River played a very important role in the supply of clay. Nile influence was reduced during the glacial period but was higher during the African Humid Period. In contrast to the sharp beginning and end of the African Humid Period recorded in West African records (15 and 5.5 ka), our data show a more transitional pattern and slightly lower Nile River discharge rates not starting until 4 ka. The similarity of the smectite concentrations with fluctuations in sea-surface temperatures of the tropical western Indian Ocean indicates a close relationship between the Indian Ocean climate system and the discharge of the Nile River.
Contributors
- Edited by Hartmut Berghoff, German Historical Institute, Washington DC, Jürgen Kocka, Wissenschaftszentrum Berlin für Sozialforschung, Dieter Ziegler, Ruhr-Universität, Bochum, Germany
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- Business in the Age of Extremes
- Published online:
- 05 September 2014
- Print publication:
- 28 January 2013, pp ix-x
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- By Bruno Allolio, Wiebke Arlt, John Bancroft, Shezad Basaria, Hermann M. Behre, Shalender Bhasin, Steven Boonen, Cesare Carani, Kevin S. Channer, Frank Claessens, Susan R. Davis, Samuel R. Denmeade, Flaminia Fanelli, Evelien Gielen, Wen Guo, Stefanie Hahner, David J. Handelsman, Olaf Hiort, John T. Isaacs, Ravi Jasuja, T. Hugh Jones, Jean-Marc Kaufman, C. Marc Luetjens, Mario Maggi, Robert I. McLachlan, Eberhard Nieschlag, Susan Nieschlag, Liza O'Donnell, Uberto Pagotto, Valerie Anne Randall, Vincenzo Rochira, Laura Roli, Daniele Santi, Wilhelm Schänzer, Carlo Serra, Manuela Simoni, Rajan Singh, Mieke Sinnesael, Thomas W. Storer, Ronald S. Swerdloff, Mario Thevis, Thomas G. Travison, Guy T'Sjoen, Dirk Vanderschueren, Alex Vermeulen, Elena Vorona, Christina C. L. Wang, Gerhard F. Weinbauer, Ralf Werner, Mikhail N. Zacharov, Michael Zitzmann
- Edited by Eberhard Nieschlag, Hermann M. Behre
- Edited in association with Susan Nieschlag
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- Book:
- Testosterone
- Published online:
- 05 August 2012
- Print publication:
- 26 July 2012, pp vii-x
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Fabrication and Characterization of Organic Thin Films for Applications in Tissue Engineering: Emphasis on Cell-Surface Interactions
- Michael R. Wertheimer, Amélie St-Georges-Robillard, Sophie Lerouge, Fackson Mwale, Bentsian Elkin, Christian Oehr, Werner Wirges, Reimund Gerhard
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- Journal:
- MRS Online Proceedings Library Archive / Volume 1469 / 2012
- Published online by Cambridge University Press:
- 18 May 2012, mrss12-1469-ww08-04
- Print publication:
- 2012
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In several recent communications from these laboratories, we have described observations that thin organic layers which are rich in primary amine (R-NH2) groups are very efficient surfaces for the adhesion of mammalian cells, even for controlling the differentiation of stem cells. We prepare such deposits by plasma polymerization at low pressure (thin films designated “L-PPE:N”, for “Low-pressure Plasma Polymerized Ethylene containing Nitrogen”), at atmospheric (“High”) pressure (“H-PPE:N”), or by vacuum-ultraviolet photo-polymerization (“UV-PE:N”). More recently, we have also investigated a commercially available material, Parylene diX AM.
In the present communication we shall, first, briefly introduce literature relating to electrostatic interactions between cells, proteins, and charged surfaces. Next, we discuss the comparative results of physico-chemical characterizations of the various organic deposits mentioned above, which deliberately contain varying concentrations of nitrogen, [N], and amine groups, [NH2]. Finally, we present certain selected cell-response results that pertain to applications in orthopedic medicine; we discuss the influence of surface properties on the observed behaviors of various cell lines, with particular emphasis on possible electrostatic attractive forces due to positively charged R-NH3+ groups and negatively charged proteins and cells, respectively.
Provenance changes between recent and glacial-time sediments in the Amundsen Sea embayment, West Antarctica: clay mineral assemblage evidence
- Werner Ehrmann, Claus-Dieter Hillenbrand, James A. Smith, Alastair G.C. Graham, Gerhard Kuhn, Robert D. Larter
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- Journal:
- Antarctic Science / Volume 23 / Issue 5 / October 2011
- Published online by Cambridge University Press:
- 18 May 2011, pp. 471-486
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The Amundsen Sea embayment is a probable site for the initiation of a future collapse of the West Antarctic Ice Sheet. This paper contributes to a better understanding of the transport pathways of subglacial sediments into this embayment at present and during the last glacial period. It discusses the clay mineral composition of sediment samples taken from the seafloor surface and marine cores in order to decipher spatial and temporal changes in the sediment provenance. The most striking feature in the present-day clay mineral distribution is the high concentration of kaolinite, which is mainly supplied by the Thwaites Glacier system and indicates the presence of hitherto unknown kaolinite-bearing sedimentary strata in the hinterland, probably in the Byrd Subglacial Basin. The main illite input is via the Pine Island Glacier. Smectite originates from the erosion of volcanic rocks in Ellsworth Land and western Marie Byrd Land. The clay mineral assemblages in diamictons deposited during the last glacial period are distinctly different from those in corresponding surface sediments. This relationship indicates that glacial sediment sources were different from modern ones, which could reflect changes in the catchment areas of the glaciers and ice streams.
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- By Rose Teteki Abbey, K. C. Abraham, David Tuesday Adamo, LeRoy H. Aden, Efrain Agosto, Victor Aguilan, Gillian T. W. Ahlgren, Charanjit Kaur AjitSingh, Dorothy B E A Akoto, Giuseppe Alberigo, Daniel E. Albrecht, Ruth Albrecht, Daniel O. Aleshire, Urs Altermatt, Anand Amaladass, Michael Amaladoss, James N. Amanze, Lesley G. Anderson, Thomas C. Anderson, Victor Anderson, Hope S. Antone, María Pilar Aquino, Paula Arai, Victorio Araya Guillén, S. Wesley Ariarajah, Ellen T. Armour, Brett Gregory Armstrong, Atsuhiro Asano, Naim Stifan Ateek, Mahmoud Ayoub, John Alembillah Azumah, Mercedes L. García Bachmann, Irena Backus, J. Wayne Baker, Mieke Bal, Lewis V. Baldwin, William Barbieri, António Barbosa da Silva, David Basinger, Bolaji Olukemi Bateye, Oswald Bayer, Daniel H. Bays, Rosalie Beck, Nancy Elizabeth Bedford, Guy-Thomas Bedouelle, Chorbishop Seely Beggiani, Wolfgang Behringer, Christopher M. Bellitto, Byard Bennett, Harold V. Bennett, Teresa Berger, Miguel A. Bernad, Henley Bernard, Alan E. Bernstein, Jon L. Berquist, Johannes Beutler, Ana María Bidegain, Matthew P. Binkewicz, Jennifer Bird, Joseph Blenkinsopp, Dmytro Bondarenko, Paulo Bonfatti, Riet en Pim Bons-Storm, Jessica A. Boon, Marcus J. Borg, Mark Bosco, Peter C. Bouteneff, François Bovon, William D. Bowman, Paul S. Boyer, David Brakke, Richard E. Brantley, Marcus Braybrooke, Ian Breward, Ênio José da Costa Brito, Jewel Spears Brooker, Johannes Brosseder, Nicholas Canfield Read Brown, Robert F. Brown, Pamela K. Brubaker, Walter Brueggemann, Bishop Colin O. Buchanan, Stanley M. Burgess, Amy Nelson Burnett, J. Patout Burns, David B. Burrell, David Buttrick, James P. Byrd, Lavinia Byrne, Gerado Caetano, Marcos Caldas, Alkiviadis Calivas, William J. Callahan, Salvatore Calomino, Euan K. Cameron, William S. Campbell, Marcelo Ayres Camurça, Daniel F. Caner, Paul E. Capetz, Carlos F. Cardoza-Orlandi, Patrick W. Carey, Barbara Carvill, Hal Cauthron, Subhadra Mitra Channa, Mark D. Chapman, James H. Charlesworth, Kenneth R. Chase, Chen Zemin, Luciano Chianeque, Philip Chia Phin Yin, Francisca H. Chimhanda, Daniel Chiquete, John T. Chirban, Soobin Choi, Robert Choquette, Mita Choudhury, Gerald Christianson, John Chryssavgis, Sejong Chun, Esther Chung-Kim, Charles M. A. Clark, Elizabeth A. Clark, Sathianathan Clarke, Fred Cloud, John B. Cobb, W. Owen Cole, John A Coleman, John J. Collins, Sylvia Collins-Mayo, Paul K. Conkin, Beth A. Conklin, Sean Connolly, Demetrios J. Constantelos, Michael A. Conway, Paula M. Cooey, Austin Cooper, Michael L. Cooper-White, Pamela Cooper-White, L. William Countryman, Sérgio Coutinho, Pamela Couture, Shannon Craigo-Snell, James L. Crenshaw, David Crowner, Humberto Horacio Cucchetti, Lawrence S. Cunningham, Elizabeth Mason Currier, Emmanuel Cutrone, Mary L. Daniel, David D. Daniels, Robert Darden, Rolf Darge, Isaiah Dau, Jeffry C. Davis, Jane Dawson, Valentin Dedji, John W. de Gruchy, Paul DeHart, Wendy J. Deichmann Edwards, Miguel A. De La Torre, George E. Demacopoulos, Thomas de Mayo, Leah DeVun, Beatriz de Vasconcellos Dias, Dennis C. Dickerson, John M. Dillon, Luis Miguel Donatello, Igor Dorfmann-Lazarev, Susanna Drake, Jonathan A. Draper, N. Dreher Martin, Otto Dreydoppel, Angelyn Dries, A. J. Droge, Francis X. D'Sa, Marilyn Dunn, Nicole Wilkinson Duran, Rifaat Ebied, Mark J. Edwards, William H. Edwards, Leonard H. Ehrlich, Nancy L. Eiesland, Martin Elbel, J. Harold Ellens, Stephen Ellingson, Marvin M. Ellison, Robert Ellsberg, Jean Bethke Elshtain, Eldon Jay Epp, Peter C. Erb, Tassilo Erhardt, Maria Erling, Noel Leo Erskine, Gillian R. Evans, Virginia Fabella, Michael A. Fahey, Edward Farley, Margaret A. Farley, Wendy Farley, Robert Fastiggi, Seena Fazel, Duncan S. Ferguson, Helwar Figueroa, Paul Corby Finney, Kyriaki Karidoyanes FitzGerald, Thomas E. FitzGerald, John R. Fitzmier, Marie Therese Flanagan, Sabina Flanagan, Claude Flipo, Ronald B. Flowers, Carole Fontaine, David Ford, Mary Ford, Stephanie A. Ford, Jim Forest, William Franke, Robert M. Franklin, Ruth Franzén, Edward H. Friedman, Samuel Frouisou, Lorelei F. Fuchs, Jojo M. Fung, Inger Furseth, Richard R. Gaillardetz, Brandon Gallaher, China Galland, Mark Galli, Ismael García, Tharscisse Gatwa, Jean-Marie Gaudeul, Luis María Gavilanes del Castillo, Pavel L. Gavrilyuk, Volney P. Gay, Metropolitan Athanasios Geevargis, Kondothra M. George, Mary Gerhart, Simon Gikandi, Maurice Gilbert, Michael J. Gillgannon, Verónica Giménez Beliveau, Terryl Givens, Beth Glazier-McDonald, Philip Gleason, Menghun Goh, Brian Golding, Bishop Hilario M. Gomez, Michelle A. Gonzalez, Donald K. Gorrell, Roy Gottfried, Tamara Grdzelidze, Joel B. Green, Niels Henrik Gregersen, Cristina Grenholm, Herbert Griffiths, Eric W. Gritsch, Erich S. Gruen, Christoffer H. Grundmann, Paul H. Gundani, Jon P. Gunnemann, Petre Guran, Vidar L. Haanes, Jeremiah M. Hackett, Getatchew Haile, Douglas John Hall, Nicholas Hammond, Daphne Hampson, Jehu J. Hanciles, Barry Hankins, Jennifer Haraguchi, Stanley S. Harakas, Anthony John Harding, Conrad L. Harkins, J. William Harmless, Marjory Harper, Amir Harrak, Joel F. Harrington, Mark W. Harris, Susan Ashbrook Harvey, Van A. Harvey, R. Chris Hassel, Jione Havea, Daniel Hawk, Diana L. Hayes, Leslie Hayes, Priscilla Hayner, S. Mark Heim, Simo Heininen, Richard P. Heitzenrater, Eila Helander, David Hempton, Scott H. Hendrix, Jan-Olav Henriksen, Gina Hens-Piazza, Carter Heyward, Nicholas J. Higham, David Hilliard, Norman A. Hjelm, Peter C. Hodgson, Arthur Holder, M. Jan Holton, Dwight N. Hopkins, Ronnie Po-chia Hsia, Po-Ho Huang, James Hudnut-Beumler, Jennifer S. Hughes, Leonard M. Hummel, Mary E. Hunt, Laennec Hurbon, Mark Hutchinson, Susan E. Hylen, Mary Beth Ingham, H. Larry Ingle, Dale T. Irvin, Jon Isaak, Paul John Isaak, Ada María Isasi-Díaz, Hans Raun Iversen, Margaret C. Jacob, Arthur James, Maria Jansdotter-Samuelsson, David Jasper, Werner G. Jeanrond, Renée Jeffery, David Lyle Jeffrey, Theodore W. Jennings, David H. Jensen, Robin Margaret Jensen, David Jobling, Dale A. Johnson, Elizabeth A. Johnson, Maxwell E. Johnson, Sarah Johnson, Mark D. Johnston, F. Stanley Jones, James William Jones, John R. Jones, Alissa Jones Nelson, Inge Jonsson, Jan Joosten, Elizabeth Judd, Mulambya Peggy Kabonde, Robert Kaggwa, Sylvester Kahakwa, Isaac Kalimi, Ogbu U. Kalu, Eunice Kamaara, Wayne C. Kannaday, Musimbi Kanyoro, Veli-Matti Kärkkäinen, Frank Kaufmann, Léon Nguapitshi Kayongo, Richard Kearney, Alice A. Keefe, Ralph Keen, Catherine Keller, Anthony J. Kelly, Karen Kennelly, Kathi Lynn Kern, Fergus Kerr, Edward Kessler, George Kilcourse, Heup Young Kim, Kim Sung-Hae, Kim Yong-Bock, Kim Yung Suk, Richard King, Thomas M. King, Robert M. Kingdon, Ross Kinsler, Hans G. Kippenberg, Cheryl A. Kirk-Duggan, Clifton Kirkpatrick, Leonid Kishkovsky, Nadieszda Kizenko, Jeffrey Klaiber, Hans-Josef Klauck, Sidney Knight, Samuel Kobia, Robert Kolb, Karla Ann Koll, Heikki Kotila, Donald Kraybill, Philip D. W. Krey, Yves Krumenacker, Jeffrey Kah-Jin Kuan, Simanga R. Kumalo, Peter Kuzmic, Simon Shui-Man Kwan, Kwok Pui-lan, André LaCocque, Stephen E. Lahey, John Tsz Pang Lai, Emiel Lamberts, Armando Lampe, Craig Lampe, Beverly J. Lanzetta, Eve LaPlante, Lizette Larson-Miller, Ariel Bybee Laughton, Leonard Lawlor, Bentley Layton, Robin A. Leaver, Karen Lebacqz, Archie Chi Chung Lee, Marilyn J. Legge, Hervé LeGrand, D. L. LeMahieu, Raymond Lemieux, Bill J. Leonard, Ellen M. Leonard, Outi Leppä, Jean Lesaulnier, Nantawan Boonprasat Lewis, Henrietta Leyser, Alexei Lidov, Bernard Lightman, Paul Chang-Ha Lim, Carter Lindberg, Mark R. Lindsay, James R. Linville, James C. Livingston, Ann Loades, David Loades, Jean-Claude Loba-Mkole, Lo Lung Kwong, Wati Longchar, Eleazar López, David W. Lotz, Andrew Louth, Robin W. Lovin, William Luis, Frank D. Macchia, Diarmaid N. J. MacCulloch, Kirk R. MacGregor, Marjory A. MacLean, Donald MacLeod, Tomas S. Maddela, Inge Mager, Laurenti Magesa, David G. Maillu, Fortunato Mallimaci, Philip Mamalakis, Kä Mana, Ukachukwu Chris Manus, Herbert Robinson Marbury, Reuel Norman Marigza, Jacqueline Mariña, Antti Marjanen, Luiz C. L. Marques, Madipoane Masenya (ngwan'a Mphahlele), Caleb J. D. Maskell, Steve Mason, Thomas Massaro, Fernando Matamoros Ponce, András Máté-Tóth, Odair Pedroso Mateus, Dinis Matsolo, Fumitaka Matsuoka, John D'Arcy May, Yelena Mazour-Matusevich, Theodore Mbazumutima, John S. McClure, Christian McConnell, Lee Martin McDonald, Gary B. McGee, Thomas McGowan, Alister E. McGrath, Richard J. McGregor, John A. McGuckin, Maud Burnett McInerney, Elsie Anne McKee, Mary B. McKinley, James F. McMillan, Ernan McMullin, Kathleen E. McVey, M. Douglas Meeks, Monica Jyotsna Melanchthon, Ilie Melniciuc-Puica, Everett Mendoza, Raymond A. Mentzer, William W. Menzies, Ina Merdjanova, Franziska Metzger, Constant J. Mews, Marvin Meyer, Carol Meyers, Vasile Mihoc, Gunner Bjerg Mikkelsen, Maria Inêz de Castro Millen, Clyde Lee Miller, Bonnie J. Miller-McLemore, Alexander Mirkovic, Paul Misner, Nozomu Miyahira, R. W. L. Moberly, Gerald Moede, Aloo Osotsi Mojola, Sunanda Mongia, Rebeca Montemayor, James Moore, Roger E. Moore, Craig E. Morrison O.Carm, Jeffry H. Morrison, Keith Morrison, Wilson J. Moses, Tefetso Henry Mothibe, Mokgethi Motlhabi, Fulata Moyo, Henry Mugabe, Jesse Ndwiga Kanyua Mugambi, Peggy Mulambya-Kabonde, Robert Bruce Mullin, Pamela Mullins Reaves, Saskia Murk Jansen, Heleen L. Murre-Van den Berg, Augustine Musopole, Isaac M. T. Mwase, Philomena Mwaura, Cecilia Nahnfeldt, Anne Nasimiyu Wasike, Carmiña Navia Velasco, Thulani Ndlazi, Alexander Negrov, James B. Nelson, David G. Newcombe, Carol Newsom, Helen J. Nicholson, George W. E. Nickelsburg, Tatyana Nikolskaya, Damayanthi M. A. Niles, Bertil Nilsson, Nyambura Njoroge, Fidelis Nkomazana, Mary Beth Norton, Christian Nottmeier, Sonene Nyawo, Anthère Nzabatsinda, Edward T. Oakes, Gerald O'Collins, Daniel O'Connell, David W. Odell-Scott, Mercy Amba Oduyoye, Kathleen O'Grady, Oyeronke Olajubu, Thomas O'Loughlin, Dennis T. Olson, J. Steven O'Malley, Cephas N. Omenyo, Muriel Orevillo-Montenegro, César Augusto Ornellas Ramos, Agbonkhianmeghe E. Orobator, Kenan B. Osborne, Carolyn Osiek, Javier Otaola Montagne, Douglas F. Ottati, Anna May Say Pa, Irina Paert, Jerry G. Pankhurst, Aristotle Papanikolaou, Samuele F. Pardini, Stefano Parenti, Peter Paris, Sung Bae Park, Cristián G. Parker, Raquel Pastor, Joseph Pathrapankal, Daniel Patte, W. Brown Patterson, Clive Pearson, Keith F. Pecklers, Nancy Cardoso Pereira, David Horace Perkins, Pheme Perkins, Edward N. Peters, Rebecca Todd Peters, Bishop Yeznik Petrossian, Raymond Pfister, Peter C. Phan, Isabel Apawo Phiri, William S. F. Pickering, Derrick G. Pitard, William Elvis Plata, Zlatko Plese, John Plummer, James Newton Poling, Ronald Popivchak, Andrew Porter, Ute Possekel, James M. Powell, Enos Das Pradhan, Devadasan Premnath, Jaime Adrían Prieto Valladares, Anne Primavesi, Randall Prior, María Alicia Puente Lutteroth, Eduardo Guzmão Quadros, Albert Rabil, Laurent William Ramambason, Apolonio M. Ranche, Vololona Randriamanantena Andriamitandrina, Lawrence R. Rast, Paul L. Redditt, Adele Reinhartz, Rolf Rendtorff, Pål Repstad, James N. Rhodes, John K. Riches, Joerg Rieger, Sharon H. Ringe, Sandra Rios, Tyler Roberts, David M. Robinson, James M. Robinson, Joanne Maguire Robinson, Richard A. H. Robinson, Roy R. Robson, Jack B. Rogers, Maria Roginska, Sidney Rooy, Rev. Garnett Roper, Maria José Fontelas Rosado-Nunes, Andrew C. Ross, Stefan Rossbach, François Rossier, John D. Roth, John K. Roth, Phillip Rothwell, Richard E. Rubenstein, Rosemary Radford Ruether, Markku Ruotsila, John E. Rybolt, Risto Saarinen, John Saillant, Juan Sanchez, Wagner Lopes Sanchez, Hugo N. Santos, Gerhard Sauter, Gloria L. Schaab, Sandra M. Schneiders, Quentin J. Schultze, Fernando F. Segovia, Turid Karlsen Seim, Carsten Selch Jensen, Alan P. F. Sell, Frank C. Senn, Kent Davis Sensenig, Damían Setton, Bal Krishna Sharma, Carolyn J. Sharp, Thomas Sheehan, N. Gerald Shenk, Christian Sheppard, Charles Sherlock, Tabona Shoko, Walter B. Shurden, Marguerite Shuster, B. Mark Sietsema, Batara Sihombing, Neil Silberman, Clodomiro Siller, Samuel Silva-Gotay, Heikki Silvet, John K. Simmons, Hagith Sivan, James C. Skedros, Abraham Smith, Ashley A. Smith, Ted A. Smith, Daud Soesilo, Pia Søltoft, Choan-Seng (C. S.) Song, Kathryn Spink, Bryan Spinks, Eric O. Springsted, Nicolas Standaert, Brian Stanley, Glen H. Stassen, Karel Steenbrink, Stephen J. Stein, Andrea Sterk, Gregory E. Sterling, Columba Stewart, Jacques Stewart, Robert B. Stewart, Cynthia Stokes Brown, Ken Stone, Anne Stott, Elizabeth Stuart, Monya Stubbs, Marjorie Hewitt Suchocki, David Kwang-sun Suh, Scott W. Sunquist, Keith Suter, Douglas Sweeney, Charles H. Talbert, Shawqi N. Talia, Elsa Tamez, Joseph B. Tamney, Jonathan Y. Tan, Yak-Hwee Tan, Kathryn Tanner, Feiya Tao, Elizabeth S. Tapia, Aquiline Tarimo, Claire Taylor, Mark Lewis Taylor, Bishop Abba Samuel Wolde Tekestebirhan, Eugene TeSelle, M. Thomas Thangaraj, David R. Thomas, Andrew Thornley, Scott Thumma, Marcelo Timotheo da Costa, George E. “Tink” Tinker, Ola Tjørhom, Karen Jo Torjesen, Iain R. Torrance, Fernando Torres-Londoño, Archbishop Demetrios [Trakatellis], Marit Trelstad, Christine Trevett, Phyllis Trible, Johannes Tromp, Paul Turner, Robert G. Tuttle, Archbishop Desmond Tutu, Peter Tyler, Anders Tyrberg, Justin Ukpong, Javier Ulloa, Camillus Umoh, Kristi Upson-Saia, Martina Urban, Monica Uribe, Elochukwu Eugene Uzukwu, Richard Vaggione, Gabriel Vahanian, Paul Valliere, T. J. Van Bavel, Steven Vanderputten, Peter Van der Veer, Huub Van de Sandt, Louis Van Tongeren, Luke A. Veronis, Noel Villalba, Ramón Vinke, Tim Vivian, David Voas, Elena Volkova, Katharina von Kellenbach, Elina Vuola, Timothy Wadkins, Elaine M. Wainwright, Randi Jones Walker, Dewey D. Wallace, Jerry Walls, Michael J. Walsh, Philip Walters, Janet Walton, Jonathan L. Walton, Wang Xiaochao, Patricia A. Ward, David Harrington Watt, Herold D. Weiss, Laurence L. Welborn, Sharon D. Welch, Timothy Wengert, Traci C. West, Merold Westphal, David Wetherell, Barbara Wheeler, Carolinne White, Jean-Paul Wiest, Frans Wijsen, Terry L. Wilder, Felix Wilfred, Rebecca Wilkin, Daniel H. Williams, D. Newell Williams, Michael A. Williams, Vincent L. Wimbush, Gabriele Winkler, Anders Winroth, Lauri Emílio Wirth, James A. Wiseman, Ebba Witt-Brattström, Teofil Wojciechowski, John Wolffe, Kenman L. Wong, Wong Wai Ching, Linda Woodhead, Wendy M. Wright, Rose Wu, Keith E. Yandell, Gale A. Yee, Viktor Yelensky, Yeo Khiok-Khng, Gustav K. K. Yeung, Angela Yiu, Amos Yong, Yong Ting Jin, You Bin, Youhanna Nessim Youssef, Eliana Yunes, Robert Michael Zaller, Valarie H. Ziegler, Barbara Brown Zikmund, Joyce Ann Zimmerman, Aurora Zlotnik, Zhuo Xinping
- Edited by Daniel Patte, Vanderbilt University, Tennessee
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- Book:
- The Cambridge Dictionary of Christianity
- Published online:
- 05 August 2012
- Print publication:
- 20 September 2010, pp xi-xliv
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An adapted filament model for accurate modeling of printed coplanar lines with significant surface roughness and proximity effects
- Brian Curran, Ivan Ndip, Christian Werner, Veronika Ruttkowski, Marcus Maiwald, Heinrich Wolf, Volker Zoellmer, Gerhard Domann, Stephan Guttovski, Horst Gieser, Herbert Reichl
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- Journal:
- International Journal of Microwave and Wireless Technologies / Volume 2 / Issue 3-4 / August 2010
- Published online by Cambridge University Press:
- 15 September 2010, pp. 273-281
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New technologies have resulted in transmission lines that deviate significantly from the intended rectangular cross sections. Trapezoidal cross sections and roughness that penetrate a significant depth into the surface in comparison to the skin-depth of the conductor can cause a very significant deviation in transmission line parameters from predicted values. Proximity effect further complicates the analysis by increasing losses and changing the impact of surface roughness by changing the current distribution. A skin-effect filament model that combines a traditional skin-effect filament modeling concept with traditional surface roughness modeling concepts is presented that accounts for surface roughness effects and non-ideal cross sections. The new technique models the transmission line non-idealities in a combined way with the current density in the signal and return current paths. This adapted filament model shows an average deviation of less than 2% above 1 GHz with one given transmission line measurement and does not have the computational challenges seen in a 3D full-wave solver.
Cognition as self–organizing process
- Gerhard Werner
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- Journal:
- Behavioral and Brain Sciences / Volume 10 / Issue 2 / June 1987
- Published online by Cambridge University Press:
- 04 February 2010, p. 183
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7 - Respiration from roots and the mycorrhizosphere
- Edited by Werner L. Kutsch, Max-Planck-Institut für Biogeochemie, Jena, Michael Bahn, Leopold-Franzens-Universität Innsbruck, Austria, Andreas Heinemeyer
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- Book:
- Soil Carbon Dynamics
- Published online:
- 11 May 2010
- Print publication:
- 07 January 2010, pp 127-156
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Summary
INTRODUCTION
The largest flux in the global carbon cycle is the uptake of CO2 by plants as photosynthesis. Estimates of gross primary production (GPP), or total amount of CO2 assimilated by terrestrial plants, range between about 109 and 120 Pg C per year at the global scale (Schlesinger, 1997; Zhao et al., 2005). Except for carbon that remains stored in passive organic matter pools, as fossil fuel, and an estimated 0.2 Pg C per year sedimenting on the ocean floors, assimilated carbon is eventually returned to the atmosphere by respiration, either by plants or by heterotrophic organisms. The time between the fixation of a carbon atom by the plant and its conversion back to CO2 is extremely variable, ranging between a few hours and thousands of years. How long it remains part of organic compounds will depend on its turnover within the plant and, eventually, as part of soil organic matter.
Carbon assimilated by plants is translocated to plant organs where it can be used as building material for structural biomass, for storage or as substrate for respiration. Carbon imported into roots can also be exudated or transferred to symbionts such as mycorrhizal fungi (Farrar, 1999). The amount of assimilated carbon used for each purpose will depend on the plant's requirements, which are further determined by plant and environmental factors.
Picosecond Polarisation Detector for Infrared and Terahertz Radiation
- Wolfgang Weber, Josef Kiermaier, Sergey N. Danilov, Dieter Schuh, Christian Gerl, Werner Wegscheider, Dominique Bougeard, Gerhard Abstreiter, Wilhelm Prettl, Sergey D. Ganichev
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- Journal:
- MRS Online Proceedings Library Archive / Volume 1016 / 2007
- Published online by Cambridge University Press:
- 01 February 2011, 1016-CC01-04
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- 2007
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We report on a room temperature detector of infrared/terahertz laser radiation allowing to measure and characterized the radiation polarization state with picosecond time resolution.
Marker-assisted introgression of the Compact mutant myostatin allele MstnCmpt-dl1Abc into a mouse line with extreme growth effects on body composition and muscularity
- LUTZ BÜNGER, GERHARD OTT, LÁSZLÓ VARGA, WERNER SCHLOTE, CHARLOTTE REHFELDT, ULLA RENNE, JOHN L. WILLIAMS, WILLIAM G. HILL
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- Journal:
- Genetical Research / Volume 84 / Issue 3 / December 2004
- Published online by Cambridge University Press:
- 14 January 2005, pp. 161-173
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Myostatin is a negative regulator of muscle growth and mutations in its gene lead to muscular hypertrophy and reduced fat. In cattle, this is seen in ‘double muscled’ breeds. We have used marker-assisted introgression to introduce a murine myostatin mutation, MstnCmpt-dl1Abc [Compact (C)], into an inbred line of mice (DUHi) that had been selected on body weight and had exceptional growth. Compared with homozygous wild-type mice, homozygous (C/C) mice of this line were ~4–5% lighter, had ~7–8% shorter tails, substantially increased muscle weights (e.g. quadriceps muscle in males was 59% heavier) and an increased ‘dressing percentage’ (~49% vs 39%), an indicator of overall muscularity. The weights of several organs (e.g. liver, kidney, heart and digestive tract) were significantly reduced, by 12–20%. Myostatin deficiency also resulted in drastic reductions of total body fat and of various fat depots, total body fat proportion falling from ~17·5% in wild-type animals of both sexes to 9·5% and 11·6% in homozygous (C/C) females and males, respectively. Males with a deficiency in myostatin had higher gains in muscle traits than females. Additionally, there was a strong distortion of the segregation ratio on the DUHi background. Of 838 genotyped pups from inter se matings 29%, 63% and 8% were homozygous wild type (+/+), heterozygous (C/+) and homozygous (C/C), respectively, showing that MstnCmpt-dl1Abc has lower fitness on this background. This line, when congenic, will be a useful resource in gene expression studies and for finding modifying genes.
Chemical Behavior and Corrosion Resistance of Medical Grade Titanium after Surface Modification by Means of Ion Implantation Techniques
- Frank Schrempel, Gerhard Hildebrand, Marion Frant, Werner Wesch, Klaus Liefeith
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- MRS Online Proceedings Library Archive / Volume 908 / 2005
- Published online by Cambridge University Press:
- 26 February 2011, 0908-OO14-22
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- 2005
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This work presents data on topographical structure, chemical surface composition, physicochemical properties and corrosion resistance of medical grade titanium after ion implantation. Pure commercial titanium has been implanted with 30 keV Na-, Ca- and P-ions at fluences of 2.0 × 1017 cm-2 and 1.5 × 1017 cm-2, respectively. Some of the samples were heat treated at 600 °C for 40 min. Atomic force microscopy (AFM) was used for surface analysis. The chemical composition was investigated using Rutherford backscattering spectrometry (RBS). Physicochemical investigations were carried out using contact angle measurements to determine the polarity of the modified titanium surfaces. Moreover, the electrokinetic zeta potentials on a physiological pH value have been determined. Finally, the corrosion resistance was examined in simulated body fluid (SBF) containing 4 g/l bovine serum albumin (BSA) using cyclic voltametry.
Considering the P-implantations, the measured depth distribution of phosphorus agrees well with calculations. For the implantation of Na and Ca, the concentration of implanted atoms in the maximum of the depth distribution is noticeably lower and the distribution extends to larger depths compared to the predictions. This finding is associated with a strong incorporation of oxygen over the whole penetration depth of the implanted ions. According to topographical and chemical changes different contact angles as well as zeta potentials have been detected for the ion implanted surfaces compared to pure titanium. The electrochemical examinations indicate that the implantation has no negative influence on the corrosion resistance in comparison to unmodified medical grade titanium. The results show that ion implantation using certain ions can be used to design tailor-made titanium surfaces from a physicochemical point of view.
Quantum Dot Growth in the Si-Ge-C System Through Multi-Step Procedure
- Yutaka Wakayama, Gerhard Gerth, Peter Werner, Leonid V. Sokolov
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- Journal:
- MRS Online Proceedings Library Archive / Volume 618 / 2000
- Published online by Cambridge University Press:
- 10 February 2011, 135
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- 2000
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To fabricate nanometer-sized Ge dots on Si(100), we have investigated multi-step procedure, involving low temperature deposition of a Ge layer, a sub-monolayer C on a Ge wetting layer, a Ge top layer for three-dimensional (3D) dot formation and post-annealing. Effects of each procedure were discussed on the basis of an atomic force microscope study. 10nm-sized Ge dots with a high number density in the order of 1011 cm−2 were grown on the Si(100) substrate by combining each procedure and optimizing experimental conditions, such as deposition temperature, the C layer thickness and post-annealing temperature.
Comparison of Growth and Strain Relaxation of Si/Ge Superlattices Under Compressive and Tensile Strain Field
- Werner Wegscheider, Karl Eberl, Gerhard Abstreiter, Hans Cerva, Helmut Oppolzer
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- MRS Online Proceedings Library Archive / Volume 220 / 1991
- Published online by Cambridge University Press:
- 22 February 2011, 135
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- 1991
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Optimization of growth parameters of short period Si/Ge superlattices (SLs) has been achieved via in situ low-energy electron diffraction (LEED) and Auger electron spectroscopy (AES) measurements during homo- and heteroepitaxy on Si (001) and Ge (001) substrates. Transmission electron microscopy (TEM) reveals that pseudomorphic SimGe12-m (m = 9 and 3 for growth on Si and Ge, respectively) SLs with extended planar layering can be prepared almost defect-free by a modified molecular beam epitaxy (MBE) technique. Whereas the SLs on Ge can be deposited at a constant substrate temperature, high-quality growth on Si demands for temperature variations of more than 100°C within one superlattice period. Strain relaxation of these SLs with increasing number of periods has been directly compared by means of TEM. For the compressively strained structures grown on Si we found misfit dislocations of the type 60° (a/2)<110>. Under opposite strain conditions i.e. for growth on Ge, strain relief occurs only by microtwin formation through successive glide of 90° (a/6)<211> Shockley partial dislocations. This is consistent with a calculation of the activation energy for both cases based on a homogeneous dislocation nucleation model.
Chemical corrosion of highly radioactive borosilicate nuclear waste glass under simulated repository conditions
- Las Werme, Inga K. Björner, Gerhard Bart, Hans U. Zwicky, Bernd Grambow, Werner Lutze, Rodney C. Ewing, Claude Magrabi
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- Journal:
- Journal of Materials Research / Volume 5 / Issue 5 / May 1990
- Published online by Cambridge University Press:
- 31 January 2011, pp. 1130-1146
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- May 1990
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This review summarizes the results of the joint Japanese (Central Research Institute of Electric Power Industry, CRIEPI, Tokyo), Swiss (National Cooperative for the Storage of Radioactive Waste, NAGRA, Baden), Swedish (Swedish Nuclear Fuel and Waste Management Company, SKB, Stockholm) international ‘JSS’ project on the determination of the chemical durability of the French nuclear waste borosilicate glass, which was completed in 1988. Radioactive and nonradioactive glass specimens were investigated. A data base was created with results from glass corrosion tests performed with different water compositions, pH values, temperatures, sample surface areas (S), solution volumes (V), and flow rates. Glass corrosion tests were performed with and without bentonite and/or steel corrosion products present. Variation of the glass composition was taken into account by including the borosilicate glass ‘MW’ in the investigations, formulated by British Nuclear Fuels, plc. An understanding was achieved of the glass corrosion process in general, and of the performance of the French glass under various potential disposal conditions in particular. A special effort was made to establish a corrosion data base, using high S/V ratios in the experiments in order to understand the glass durability in the long term.
New Relaxation Mechanism in Short Period Si/Ge Strained-Layer Superlattices
- Werner Wegscheider, Karl Eberl, Gerhard Abstreiter, Hans Cerva, Helmut Oppolzer
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- MRS Online Proceedings Library Archive / Volume 183 / 1990
- Published online by Cambridge University Press:
- 21 February 2011, 155
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- 1990
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High quality Si/Ge strained-layer superlattices composed of a sequence of alternating 3 monolayers pure Si and 9 monolayers pure Ge have been grown by molecular beam epitaxy at 310°C on Ge(001) substrates. In order to investigate the transition from coherent to incoherent growth in these tensily strained structures a set of samples with varying number of superlattice periods has been studied by transmission electron microscopy. It is found that superlattices as thick as 33 nm at least show perfect and defect-free layer growth whereas for thicker superlattices strain accommodation occurs. For this strained heteroepitaxial system we observed, to our knowledge, for the first time the formation of microtwins as the only relaxation mechanism. High-resolution lattice imaging reveals that the twin lamellae result from successive glide of 90° (a/6)<112> Shockley partial dislocations on adjacent {111} planes from the surface towards the bulk. The activation barrier which has to be overcome in the case of 90° partial dislocations is compared with the energies required for the nucleation of 60° perfect and 30° partial misfit dislocation half-loops.