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Regional Cotton Acreage Response
- Patricia A. Duffy, James W. Richardson, Michael K. Wohlgenant
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- Journal:
- Journal of Agricultural and Applied Economics / Volume 19 / Issue 1 / July 1987
- Published online by Cambridge University Press:
- 28 April 2015, pp. 99-110
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An econometric model of cotton acreage response was estimated for four distinct production regions in the United States. This work builds on previous work in the area of supply response under government farm programs and provides up-to-date regionalized estimates of own-price elasticity of cotton acreage supply. The own-price variable used in this study is a weighted combination of expected market price and government policy variables. Results indicate regional similarity in response to own price but differences with respect to the prices of alternative enterprises. Differences in regional response to paid diversion are also indicated.
Contributors
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- By Mitchell Aboulafia, Frederick Adams, Marilyn McCord Adams, Robert M. Adams, Laird Addis, James W. Allard, David Allison, William P. Alston, Karl Ameriks, C. Anthony Anderson, David Leech Anderson, Lanier Anderson, Roger Ariew, David Armstrong, Denis G. Arnold, E. J. Ashworth, Margaret Atherton, Robin Attfield, Bruce Aune, Edward Wilson Averill, Jody Azzouni, Kent Bach, Andrew Bailey, Lynne Rudder Baker, Thomas R. Baldwin, Jon Barwise, George Bealer, William Bechtel, Lawrence C. Becker, Mark A. Bedau, Ernst Behler, José A. Benardete, Ermanno Bencivenga, Jan Berg, Michael Bergmann, Robert L. Bernasconi, Sven Bernecker, Bernard Berofsky, Rod Bertolet, Charles J. Beyer, Christian Beyer, Joseph Bien, Joseph Bien, Peg Birmingham, Ivan Boh, James Bohman, Daniel Bonevac, Laurence BonJour, William J. Bouwsma, Raymond D. Bradley, Myles Brand, Richard B. Brandt, Michael E. Bratman, Stephen E. Braude, Daniel Breazeale, Angela Breitenbach, Jason Bridges, David O. Brink, Gordon G. Brittan, Justin Broackes, Dan W. Brock, Aaron Bronfman, Jeffrey E. Brower, Bartosz Brozek, Anthony Brueckner, Jeffrey Bub, Lara Buchak, Otavio Bueno, Ann E. Bumpus, Robert W. Burch, John Burgess, Arthur W. Burks, Panayot Butchvarov, Robert E. Butts, Marina Bykova, Patrick Byrne, David Carr, Noël Carroll, Edward S. Casey, Victor Caston, Victor Caston, Albert Casullo, Robert L. Causey, Alan K. L. Chan, Ruth Chang, Deen K. Chatterjee, Andrew Chignell, Roderick M. Chisholm, Kelly J. Clark, E. J. Coffman, Robin Collins, Brian P. Copenhaver, John Corcoran, John Cottingham, Roger Crisp, Frederick J. Crosson, Antonio S. Cua, Phillip D. Cummins, Martin Curd, Adam Cureton, Andrew Cutrofello, Stephen Darwall, Paul Sheldon Davies, Wayne A. Davis, Timothy Joseph Day, Claudio de Almeida, Mario De Caro, Mario De Caro, John Deigh, C. F. Delaney, Daniel C. Dennett, Michael R. DePaul, Michael Detlefsen, Daniel Trent Devereux, Philip E. Devine, John M. Dillon, Martin C. Dillon, Robert DiSalle, Mary Domski, Alan Donagan, Paul Draper, Fred Dretske, Mircea Dumitru, Wilhelm Dupré, Gerald Dworkin, John Earman, Ellery Eells, Catherine Z. Elgin, Berent Enç, Ronald P. Endicott, Edward Erwin, John Etchemendy, C. Stephen Evans, Susan L. Feagin, Solomon Feferman, Richard Feldman, Arthur Fine, Maurice A. Finocchiaro, William FitzPatrick, Richard E. Flathman, Gvozden Flego, Richard Foley, Graeme Forbes, Rainer Forst, Malcolm R. Forster, Daniel Fouke, Patrick Francken, Samuel Freeman, Elizabeth Fricker, Miranda Fricker, Michael Friedman, Michael Fuerstein, Richard A. Fumerton, Alan Gabbey, Pieranna Garavaso, Daniel Garber, Jorge L. A. Garcia, Robert K. Garcia, Don Garrett, Philip Gasper, Gerald Gaus, Berys Gaut, Bernard Gert, Roger F. Gibson, Cody Gilmore, Carl Ginet, Alan H. Goldman, Alvin I. Goldman, Alfonso Gömez-Lobo, Lenn E. Goodman, Robert M. Gordon, Stefan Gosepath, Jorge J. E. Gracia, Daniel W. Graham, George A. Graham, Peter J. Graham, Richard E. Grandy, I. Grattan-Guinness, John Greco, Philip T. Grier, Nicholas Griffin, Nicholas Griffin, David A. Griffiths, Paul J. Griffiths, Stephen R. Grimm, Charles L. Griswold, Charles B. Guignon, Pete A. Y. Gunter, Dimitri Gutas, Gary Gutting, Paul Guyer, Kwame Gyekye, Oscar A. Haac, Raul Hakli, Raul Hakli, Michael Hallett, Edward C. Halper, Jean Hampton, R. James Hankinson, K. R. Hanley, Russell Hardin, Robert M. Harnish, William Harper, David Harrah, Kevin Hart, Ali Hasan, William Hasker, John Haugeland, Roger Hausheer, William Heald, Peter Heath, Richard Heck, John F. Heil, Vincent F. Hendricks, Stephen Hetherington, Francis Heylighen, Kathleen Marie Higgins, Risto Hilpinen, Harold T. Hodes, Joshua Hoffman, Alan Holland, Robert L. Holmes, Richard Holton, Brad W. Hooker, Terence E. Horgan, Tamara Horowitz, Paul Horwich, Vittorio Hösle, Paul Hoβfeld, Daniel Howard-Snyder, Frances Howard-Snyder, Anne Hudson, Deal W. Hudson, Carl A. Huffman, David L. Hull, Patricia Huntington, Thomas Hurka, Paul Hurley, Rosalind Hursthouse, Guillermo Hurtado, Ronald E. Hustwit, Sarah Hutton, Jonathan Jenkins Ichikawa, Harry A. Ide, David Ingram, Philip J. Ivanhoe, Alfred L. Ivry, Frank Jackson, Dale Jacquette, Joseph Jedwab, Richard Jeffrey, David Alan Johnson, Edward Johnson, Mark D. Jordan, Richard Joyce, Hwa Yol Jung, Robert Hillary Kane, Tomis Kapitan, Jacquelyn Ann K. Kegley, James A. Keller, Ralph Kennedy, Sergei Khoruzhii, Jaegwon Kim, Yersu Kim, Nathan L. King, Patricia Kitcher, Peter D. Klein, E. D. Klemke, Virginia Klenk, George L. Kline, Christian Klotz, Simo Knuuttila, Joseph J. Kockelmans, Konstantin Kolenda, Sebastian Tomasz Kołodziejczyk, Isaac Kramnick, Richard Kraut, Fred Kroon, Manfred Kuehn, Steven T. Kuhn, Henry E. Kyburg, John Lachs, Jennifer Lackey, Stephen E. Lahey, Andrea Lavazza, Thomas H. Leahey, Joo Heung Lee, Keith Lehrer, Dorothy Leland, Noah M. Lemos, Ernest LePore, Sarah-Jane Leslie, Isaac Levi, Andrew Levine, Alan E. Lewis, Daniel E. Little, Shu-hsien Liu, Shu-hsien Liu, Alan K. L. Chan, Brian Loar, Lawrence B. Lombard, John Longeway, Dominic McIver Lopes, Michael J. Loux, E. J. Lowe, Steven Luper, Eugene C. Luschei, William G. Lycan, David Lyons, David Macarthur, Danielle Macbeth, Scott MacDonald, Jacob L. Mackey, Louis H. Mackey, Penelope Mackie, Edward H. Madden, Penelope Maddy, G. B. Madison, Bernd Magnus, Pekka Mäkelä, Rudolf A. Makkreel, David Manley, William E. Mann (W.E.M.), Vladimir Marchenkov, Peter Markie, Jean-Pierre Marquis, Ausonio Marras, Mike W. Martin, A. P. Martinich, William L. McBride, David McCabe, Storrs McCall, Hugh J. McCann, Robert N. McCauley, John J. McDermott, Sarah McGrath, Ralph McInerny, Daniel J. McKaughan, Thomas McKay, Michael McKinsey, Brian P. McLaughlin, Ernan McMullin, Anthonie Meijers, Jack W. Meiland, William Jason Melanson, Alfred R. Mele, Joseph R. Mendola, Christopher Menzel, Michael J. Meyer, Christian B. Miller, David W. Miller, Peter Millican, Robert N. Minor, Phillip Mitsis, James A. Montmarquet, Michael S. Moore, Tim Moore, Benjamin Morison, Donald R. Morrison, Stephen J. Morse, Paul K. Moser, Alexander P. D. Mourelatos, Ian Mueller, James Bernard Murphy, Mark C. Murphy, Steven Nadler, Jan Narveson, Alan Nelson, Jerome Neu, Samuel Newlands, Kai Nielsen, Ilkka Niiniluoto, Carlos G. Noreña, Calvin G. Normore, David Fate Norton, Nikolaj Nottelmann, Donald Nute, David S. Oderberg, Steve Odin, Michael O’Rourke, Willard G. Oxtoby, Heinz Paetzold, George S. Pappas, Anthony J. Parel, Lydia Patton, R. P. Peerenboom, Francis Jeffry Pelletier, Adriaan T. Peperzak, Derk Pereboom, Jaroslav Peregrin, Glen Pettigrove, Philip Pettit, Edmund L. Pincoffs, Andrew Pinsent, Robert B. Pippin, Alvin Plantinga, Louis P. Pojman, Richard H. Popkin, John F. Post, Carl J. Posy, William J. Prior, Richard Purtill, Michael Quante, Philip L. Quinn, Philip L. Quinn, Elizabeth S. Radcliffe, Diana Raffman, Gerard Raulet, Stephen L. Read, Andrews Reath, Andrew Reisner, Nicholas Rescher, Henry S. Richardson, Robert C. Richardson, Thomas Ricketts, Wayne D. Riggs, Mark Roberts, Robert C. Roberts, Luke Robinson, Alexander Rosenberg, Gary Rosenkranz, Bernice Glatzer Rosenthal, Adina L. Roskies, William L. Rowe, T. M. Rudavsky, Michael Ruse, Bruce Russell, Lilly-Marlene Russow, Dan Ryder, R. M. Sainsbury, Joseph Salerno, Nathan Salmon, Wesley C. Salmon, Constantine Sandis, David H. Sanford, Marco Santambrogio, David Sapire, Ruth A. Saunders, Geoffrey Sayre-McCord, Charles Sayward, James P. Scanlan, Richard Schacht, Tamar Schapiro, Frederick F. Schmitt, Jerome B. Schneewind, Calvin O. Schrag, Alan D. Schrift, George F. Schumm, Jean-Loup Seban, David N. Sedley, Kenneth Seeskin, Krister Segerberg, Charlene Haddock Seigfried, Dennis M. Senchuk, James F. Sennett, William Lad Sessions, Stewart Shapiro, Tommie Shelby, Donald W. Sherburne, Christopher Shields, Roger A. Shiner, Sydney Shoemaker, Robert K. Shope, Kwong-loi Shun, Wilfried Sieg, A. John Simmons, Robert L. Simon, Marcus G. Singer, Georgette Sinkler, Walter Sinnott-Armstrong, Matti T. Sintonen, Lawrence Sklar, Brian Skyrms, Robert C. Sleigh, Michael Anthony Slote, Hans Sluga, Barry Smith, Michael Smith, Robin Smith, Robert Sokolowski, Robert C. Solomon, Marta Soniewicka, Philip Soper, Ernest Sosa, Nicholas Southwood, Paul Vincent Spade, T. L. S. Sprigge, Eric O. Springsted, George J. Stack, Rebecca Stangl, Jason Stanley, Florian Steinberger, Sören Stenlund, Christopher Stephens, James P. Sterba, Josef Stern, Matthias Steup, M. A. Stewart, Leopold Stubenberg, Edith Dudley Sulla, Frederick Suppe, Jere Paul Surber, David George Sussman, Sigrún Svavarsdóttir, Zeno G. Swijtink, Richard Swinburne, Charles C. Taliaferro, Robert B. Talisse, John Tasioulas, Paul Teller, Larry S. Temkin, Mark Textor, H. S. Thayer, Peter Thielke, Alan Thomas, Amie L. Thomasson, Katherine Thomson-Jones, Joshua C. Thurow, Vzalerie Tiberius, Terrence N. Tice, Paul Tidman, Mark C. Timmons, William Tolhurst, James E. Tomberlin, Rosemarie Tong, Lawrence Torcello, Kelly Trogdon, J. D. Trout, Robert E. Tully, Raimo Tuomela, John Turri, Martin M. Tweedale, Thomas Uebel, Jennifer Uleman, James Van Cleve, Harry van der Linden, Peter van Inwagen, Bryan W. Van Norden, René van Woudenberg, Donald Phillip Verene, Samantha Vice, Thomas Vinci, Donald Wayne Viney, Barbara Von Eckardt, Peter B. M. Vranas, Steven J. Wagner, William J. Wainwright, Paul E. Walker, Robert E. Wall, Craig Walton, Douglas Walton, Eric Watkins, Richard A. Watson, Michael V. Wedin, Rudolph H. Weingartner, Paul Weirich, Paul J. Weithman, Carl Wellman, Howard Wettstein, Samuel C. Wheeler, Stephen A. White, Jennifer Whiting, Edward R. Wierenga, Michael Williams, Fred Wilson, W. Kent Wilson, Kenneth P. Winkler, John F. Wippel, Jan Woleński, Allan B. Wolter, Nicholas P. Wolterstorff, Rega Wood, W. Jay Wood, Paul Woodruff, Alison Wylie, Gideon Yaffe, Takashi Yagisawa, Yutaka Yamamoto, Keith E. Yandell, Xiaomei Yang, Dean Zimmerman, Günter Zoller, Catherine Zuckert, Michael Zuckert, Jack A. Zupko (J.A.Z.)
- Edited by Robert Audi, University of Notre Dame, Indiana
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- Book:
- The Cambridge Dictionary of Philosophy
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- 05 August 2015
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- 27 April 2015, pp ix-xxx
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Contributors
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- By John A. Bargh, Lisa Feldman Barrett, Veronica Benet-Martínez, Elliot T. Berkman, Jim Blascovich, Marilynn B. Brewer, Heining Cham, Tanya L. Chartrand, Robert B. Cialdini, William D. Crano, William A. Cunningham, Rick Dale, Jan De Houwer, Alice H. Eagly, J. Mark Eddy, Craig K. Enders, Leandre R. Fabrigar, Susan T. Fiske, Shelly L. Gable, Bertram Gawronski, Kevin J. Grimm, K. Paige Harden, Richard E. Heyman, Oliver P. John, Blair T. Johnson, Charles M. Judd, Deborah A. Kashy, David A. Kenny, Norbert L. Kerr, Nuri Kim, Jon A. Krosnick, Paul J. Lavrakas, Matthew D. Lieberman, Kristen A. Lindquist, Todd D. Little, Yu Liu, Michael F. Lorber, Michael R. Maniaci, Kerry L. Marsh, Gina L. Mazza, Gary H. McClelland, Dominique Muller, Elizabeth Levy Paluck, Karen S. Quigley, Harry T. Reis, Mijke Rhemtulla, Michael J. Richardson, Ronald D. Rogge, Alexander M. Schoemann, Eliot R. Smith, R. Scott Tindale, Eric Turkheimer, Penny S. Visser, Duane T. Wegener, Stephen G. West, Tessa V. West, Keith F. Widaman, Vincent Y. Yzerbyt
- Edited by Harry T. Reis, University of Rochester, New York, Charles M. Judd, University of Colorado Boulder
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- Book:
- Handbook of Research Methods in Social and Personality Psychology
- Published online:
- 05 June 2014
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- 24 February 2014, pp vii-viii
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Notes on Contributors
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- By David Amigoni, Mark Asquith, Jane Bownas, Adelene Buckland, Carolyn Burdett, Pamela Dalziel, Christine DeVine, Tim Dolin, Roger Ebbatson, Trish Ferguson, Shanyn Fiske, Simon Gatrell, Sophie Gilmartin, William Greenslade, Ann Heilmann, Michael Herbert, John Hughes, Rena Jackson, Elizabeth Langland, Sarah E. Maier, Phillip Mallett, Francesco Marroni, Jane Mattisson, Andrew Nash, K. M. Newton, Francis O’Gorman, John Osborne, Patrick Parrinder, Andrew Radford, Fred Reid, Angelique Richardson, Mary Rimmer, Peter Robinson, Dennis Taylor, Jenny Bourne, Jane Thomas, Herbert F. Tucker, Norman Vance, Roger Webster, Rebecca Welshman, Glen Wickens, Melanie Williams, Keith Wilson, T. R. Wright
- Edited by Phillip Mallett, University of St Andrews, Scotland
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- Book:
- Thomas Hardy in Context
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- 05 February 2013
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- 18 March 2013, pp ix-xvi
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13 - Manus horribilis: the chicken wing skeleton
- Edited by Robert J. Asher, University of Cambridge, Johannes Müller
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- From Clone to Bone
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- 05 November 2012
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- 18 October 2012, pp 328-362
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Summary
Introduction
Evolution is a natural experiment that has been running for millions of years (Shubin 1991). Developmental biologists and palaeontologists can learn from this experiment (Zákány and Duboule 2007; see also chapters in this volume by Anthwal and Tucker; Buchholtz; Kuratani and Nagashima; Mitgutsch et al.; Schmid; Sears et al.; Smith and Johanson). A particular challenge is the homology of elements distal to the ulna and radius in modern birds. Developmental biologists differ on how many skeletal primordia actually develop in the embryonic wing bud, and the homologies of the permanent bones of the avian wrist are also uncertain.
Study of the avian wing is important for several reasons. First, the wing skeleton is an important issue in discussions about avian origins (Ostrom 1975; Müller 1991; Feduccia 2002; Prum 2002; Vargas and Fallon 2005b; Feduccia et al. 2007). Furthermore, the chicken is a key model species in developmental biology, and the development of its wing has been intensively studied in the context of pattern formation theory (Tickle 2004). Finally, the fact that the avian wing is studied by developmental biologists, palaeontologists, morphologists and others makes it a suitable subject of enquiry for the integrated discipline of evo devo (Galis et al. 2003).
12 - A molecular–morphological study of a peculiar limb morphology: the development and evolution of the mole's ‘thumb’
- Edited by Robert J. Asher, University of Cambridge, Johannes Müller
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- From Clone to Bone
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- 05 November 2012
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- 18 October 2012, pp 301-327
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Summary
Introduction
Few areas of evolutionary investigation have benefited so much from the integration of molecular and morphological studies as that of the evolution of limbs (e.g. Shubin et al. 2009). Much effort has been concentrated on understanding the transition from ‘fins to limbs’ (Westoll 1943; Coates 1995; Shubin 1995; Shubin et al. 1997, 2004, 2006; Coates et al. 2002; Johanson et al. 2007; Larsson 2007) – for a recent summary of different aspects see Hall (2007) – but also major advances have been made concerning the origin and development of particularly specialized limbs such as those of bats (Sears et al. 2006; Sears 2008), whales (Thewissen et al. 2006), or their absence in snakes (Cohn and Tickle 1999). In fact, tetrapod limbs exhibit a stunning morphological diversity, reflecting their recruitment for a wide variety of functions ranging from walking to watch-making, often deployed as multipurpose structures serving in locomotion and support, personal hygiene, fighting, mating, manipulation and communication.
The reconstructed ground pattern of extant tetrapods may be viewed as a limb with a proximal stylopod (humeral/femoral region), a zeugopod (radial and ulnar/tibial and fibular region) and a distal, pentadactylous autopod (carpal/tarsal region), which contains the proximal mesopodium (wrist and ankle bones) and the terminal acropodium (the digits). With the notable exception of limbless tetrapods, most tetrapod limbs conservatively retain this pattern (Goodwin and Trainor 1983; Holder 1983). Based on these components, the diversity of skeletal morphology in tetrapod limbs is generated largely by differential growth and proportional changes of the common elements. Regarding the acropodia, hypodactyly, hyperphalangy and modifications of branching patterns involve various developmental mechanisms (Motani 1999; Hamrick 2001b, 2002; Richardson and Oelschläger 2002; Fedak and Hall 2004; Sears et al. 2007; Rolian 2008; Weisbecker and Nilsson 2008; Cooper and Dawson 2009).
Contributors
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- By Avishek Adhikari, Susanne E. Ahmari, Anne Marie Albano, Carlos Blanco, Desiree K. Caban, Jonathan S. Comer, Jeremy D. Coplan, Ana Alicia De La Cruz, Emily R. Doherty, Bruce Dohrenwend, Amit Etkin, Brian A. Fallon, Michael B. First, Abby J. Fyer, Angela Ghesquiere, Jay A. Gingrich, Robert A. Glick, Joshua A. Gordon, Ethan E. Gorenstein, Marco A. Grados, James P. Hambrick, James Hanks, Kelli Jane K. Harding, Richard G. Heimberg, Rene Hen, Devon E. Hinton, Myron A. Hofer, Matthew J. Kaplowitz, Sharaf S. Khan, Donald F. Klein, Karestan C. Koenen, E. David Leonardo, Roberto Lewis-Fernández, Jeffrey A. Lieberman, Michael R. Liebowitz, Sarah H. Lisanby, Antonio Mantovani, John C. Markowitz, Patrick J. McGrath, Caitlin McOmish, Jeffrey M. Miller, Jan Mohlman, Elizabeth Sagurton Mulhare, Philip R. Muskin, Navin Arun Natarajan, Yuval Neria, Nicole R. Nugent, Mayumi Okuda, Mark Olfson, Laszlo A. Papp, Sapana R. Patel, Anthony Pinto, Kristin Pontoski, Jesse W. Richardson-Jones, Carolyn I. Rodriguez, Steven P. Roose, Moira A. Rynn, Franklin Schneier, M. Katherine Shear, Ranjeeb Shrestha, Helen Blair Simpson, Smit S. Sinha, Natalia Skritskaya, Jami Socha, Eun Jung Suh, Gregory M. Sullivan, Anthony J. Tranguch, Hilary B. Vidair, Tor D. Wager, Myrna M Weissman, Noelia V. Weisstaub
- Edited by Helen Blair Simpson, Columbia University, New York, Yuval Neria, Columbia University, New York, Roberto Lewis-Fernández, Columbia University, New York, Franklin Schneier, Columbia University, New York
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- Book:
- Anxiety Disorders
- Published online:
- 10 November 2010
- Print publication:
- 26 August 2010, pp vii-xii
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Contributors
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- By Fred Adams, Kenneth Aizawa, Varol Akman, Murat Aydede, Lawrence W. Barsalou, William Bechtel, Henry Brighton, Jerome R. Busemeyer, William J. Clancey, Andy Clark, Frederica R. Conrey, Eric Dimperio, Chris Eliasmith, Shaun Gallagher, James G. Greeno, Paul Griffiths, Ryan K. Jessup, Michael P. Kaschak, David Kirsh, Malcolm A. MacIver, Ruth Millikan, Erik Myin, J. Kevin O’Regan, Jesse Prinz, Daniel Richardson, Philip Robbins, Mark Rowlands, Robert Rupert, R. Keith Sawyer, Andrea Scarantino, Eliot R. Smith, Michael Spivey, John Sutton, Peter M. Todd, Michael Tomasello, Barbara Tversky, Felix Warneken, Robert A. Wilson, Rolf A. Zwaan
- Edited by Philip Robbins, Washington University, St Louis, Murat Aydede, University of Florida
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- Book:
- The Cambridge Handbook of Situated Cognition
- Published online:
- 05 June 2012
- Print publication:
- 03 November 2008, pp ix-xii
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Development of the human pulmonary vein and its incorporation in the morphologically left atrium
- Sandra Webb, Mazyar Kanani, Robert H. Anderson, Michael K. Richardson, Nigel A. Brown
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- Journal:
- Cardiology in the Young / Volume 11 / Issue 6 / November 2001
- Published online by Cambridge University Press:
- 15 August 2006, pp. 632-642
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Objective: Using a newly acquired archive of previously prepared material, we sought to re-examine the origin of the pulmonary vein in the human heart, aiming to determine whether it originates from the systemic venous sinus (“sinus venosus”), or appears as a new structure draining to the left atrium. In addition, we examined the temporal sequence of incorporation of the initially solitary pulmonary vein to the stage at which four venous orifices opened to the left atrium. Methods: We studied 26 normal human embryos, ranging from 3.8 mm to 112 mm crown-rump length, and representing the period from the 12th Carnegie stage to 15 weeks of gestation. Results: The pulmonary vein canalised as a solitary vessel within the mediastinal tissues so as to connect the intraparenchymal pulmonary venous networks to the heart, using the regressing dorsal mesocardium as its portal of cardiac entry. The vein was always distinct from the tributaries of the embryonic systemic venous sinus. The orifice of the solitary vein became committed to the left atrium by growth of the vestibular spine. During development, a marked disparity was seen between the temporal and morphological patterns of incorporation of the left-sided and right-sided veins into the left atrium. The pattern of the primary bifurcation was asymmetrical, a much longer tributary being formed on the left than on the right. Contact between the atrial wall and the venous tributary on the left initially produced a shelf, which became effaced with incorporation of the two left-sided veins into the atrium. Conclusions: The initial process of formation of the human pulmonary vein is very similar to that seen in animal models. The walls of the initially solitary vein in humans become incorporated by a morphologically asymmetric process so that four pulmonary veins eventually drain independently into the left atrium. Failure of incorporation on the left side may provide the substrate for congenital division of the left atrium.
Haeckel's ABC of evolution and development
- MICHAEL K. RICHARDSON, GERHARD KEUCK
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- Journal:
- Biological Reviews / Volume 77 / Issue 4 / November 2002
- Published online by Cambridge University Press:
- 11 December 2002, pp. 495-528
- Print publication:
- November 2002
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One of the central, unresolved controversies in biology concerns the distribution of primitive versus advanced characters at different stages of vertebrate development. This controversy has major implications for evolutionary developmental biology and phylogenetics. Ernst Haeckel addressed the issue with his Biogenetic Law, and his embryo drawings functioned as supporting data. We re-examine Haeckel's work and its significance for modern efforts to develop a rigorous comparative framework for developmental studies. Haeckel's comparative embryology was evolutionary but non-quantitative. It was based on developmental sequences, and treated heterochrony as a sequence change. It is not always clear whether he believed in recapitulation of single characters or entire stages. The Biogenetic Law is supported by several recent studies – if applied to single characters only. Haeckel's important but overlooked alphabetical analogy of evolution and development is an advance on von Baer. Haeckel recognized the evolutionary diversity in early embryonic stages, in line with modern thinking. He did not necessarily advocate the strict form of recapitulation and terminal addition commonly attributed to him. Haeckel's much-criticized embryo drawings are important as phylogenetic hypotheses, teaching aids, and evidence for evolution. While some criticisms of the drawings are legitimate, others are more tendentious. In opposition to Haeckel and his embryo drawings, Wilhelm His made major advances towards developing a quantitative comparative embryology based on morphometrics. Unfortunately His's work in this area is largely forgotten. Despite his obvious flaws, Haeckel can be seen as the father of a sequence-based phylogenetic embryology.
Exploring steric constraints on protein mutations using MAGE/PROBE
- J. MICHAEL WORD, ROBERT C. BATEMAN, BRENT K. PRESLEY, SIMON C. LOVELL, DAVID C. RICHARDSON
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- Journal:
- Protein Science / Volume 9 / Issue 11 / November 2000
- Published online by Cambridge University Press:
- 15 December 2000, pp. 2251-2259
- Print publication:
- November 2000
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When planning a mutation to test some hypothesis, one crucial question is whether the new side chain is compatible with the existing structure; only if it is compatible can the interpretation of mutational results be straightforward. This paper presents a simple way of using the sensitive geometry of all-atom contacts (including hydrogens) to answer that question. The interactive MAGE/PROBE system lets the biologist explore conformational space for the mutant side chain, with an interactively updated kinemage display of its all-atom contacts to the original structure. The Autobondrot function in PROBE systematically explores that same conformational space, outputting contact scores at each point, which are then contoured and displayed. These procedures are applied here in two types of test cases, with known mutant structures. In ricin A chain, the ability of a neighboring glutamate to rescue activity of an active-site mutant is modeled successfully. In T4 lysozyme, six mutations to Leu are analyzed within the wild-type background structure, and their Autobondrot score maps correctly predict whether or not their surroundings must shift significantly in the actual mutant structures; interactive examination of contacts for the conformations involved explains which clashes are relieved by the motions. These programs are easy to use, are available free for UNIX or Microsoft Windows operating systems, and should be of significant help in choosing good mutation experiments or in understanding puzzling results.
Limb development and evolution: a frog embryo with no apical ectodermal ridge (AER)
- MICHAEL K. RICHARDSON, TIMOTHY F. CARL, JAMES HANKEN, RICHARD P. ELINSON, CELIA COPE, PETER BAGLEY
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- Journal:
- The Journal of Anatomy / Volume 192 / Issue 3 / April 1998
- Published online by Cambridge University Press:
- 01 April 1998, pp. 379-390
- Print publication:
- April 1998
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The treefrog Eleutherodactylus coqui is a direct developer — it has no tadpole stage. The limb buds develop earlier than in metamorphosing species (indirect developers, such as Xenopus laevis). Previous molecular studies suggest that at least some mechanisms of limb development in E. coqui are similar to those of other vertebrates and we wished to see how limb morphogenesis in this species compares with that in other vertebrates. We found that the hind limb buds are larger and more advanced than the forelimbs at all stages examined, thus differing from the typical amniote pattern. The limb buds were also small compared to those in the chick. Scanning and transmission electron microscopy showed that although the apical ectoderm is thickened, there was no apical ectodermal ridge (AER). In addition, the limb buds lacked the dorsoventral flattening seen in many amniotes. These findings could suggest a mechanical function for the AER in maintaining dorsoventral flattening, although not all data are consistent with this view. Removal of distal ectoderm from E. coqui hindlimb buds does not stop outgrowth, although it does produce anterior defects in the skeletal pattern. The defects are less severe when the excisions are performed earlier. These results contrast with the chick, in which AER excision leads to loss of distal structures. We suggest that an AER was present in the common ancestor of anurans and amniotes and has been lost in at least some direct developers including E. coqui.
Symposium on Neural Crest Development
- MICHAEL K. RICHARDSON, DOROTHY C. BENNETT
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- Journal:
- The Journal of Anatomy / Volume 191 / Issue 4 / November 1997
- Published online by Cambridge University Press:
- 01 November 1997, p. 481
- Print publication:
- November 1997
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The following review articles are based on presentations given at a Symposium on Neural Crest Development, held in December 1996 at St George's Hospital Medical School, London. The Symposium formed part of the Winter Meeting of the Anatomical Society of Great Britain and Ireland. There were 6 invited speakers, 5 selected short presentations, and posters. The topics ranged widely, from autocrine regulation of Schwann cell development through clinical and animal disorders involving the melanocyte lineage, the heart and other organs, to the regulation of neural crest cell differentiation by cytokines.