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Image-Based Analysis of Weathered Slag for Calculation of Transport Properties and Passive Carbon Capture
- Faisal W. K. Khudhur, Alice Macente, John M. MacDonald, Luke Daly
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- Journal:
- Microscopy and Microanalysis / Volume 28 / Issue 5 / October 2022
- Published online by Cambridge University Press:
- 04 July 2022, pp. 1514-1525
- Print publication:
- October 2022
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Weathering of silicate-rich industrial wastes such as slag can reduce emissions from the steelmaking industry. During slag weathering, different minerals spontaneously react with atmospheric CO2 to produce calcite. Here, we evaluate the CO2 uptake during slag weathering using image-based analysis. The analysis was applied to an X-ray computed tomography (XCT) dataset of a slag sample associated with the former Ravenscraig steelworks in Lanarkshire, Scotland. The element distribution of the sample was studied using scanning electron microscopy (SEM), coupled with energy-dispersive spectroscopy (EDS). Two advanced image segmentation methods, namely trainable WEKA segmentation in the Fiji distribution of ImageJ and watershed segmentation in Avizo ® 9.3.0, were used to segment the XCT images into matrix, pore space, calcite, and other precipitates. Both methods yielded similar volume fractions of the segmented classes. However, WEKA segmentation performed better in segmenting smaller pores, while watershed segmentation was superior in overcoming the partial volume effect presented in the XCT data. We estimate that CO2 has been captured in the studied sample with an uptake between 20 and 17 kg CO2/1,000 kg slag for TWS and WS, respectively, through calcite precipitation.
4 - Water Budgets in Ecosystems
- from Part II - Transport Processes and Conservation Budgets in Biogeoscience
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- By John W. Pomeroy, University of Saskatchewan, Matthew K. MacDonald, University of Edinburgh, Pablo F. Dornes, Universidad Nacional de La Pampa, Robert Armstrong, University of Queensland
- Edited by Edward A. Johnson, University of Calgary, Yvonne E. Martin, University of Calgary
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- Book:
- A Biogeoscience Approach to Ecosystems
- Published online:
- 27 October 2016
- Print publication:
- 13 October 2016, pp 88-132
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Summary
Introduction
Water is the foundation of all ecosystems, whether terrestrial or aquatic. In terrestrial ecosystems freshwater not only provides critical water supply for transpiration during plant photosynthesis and drinking water for animals, but also transports, redistributes and stores energy, nutrients and contaminants. In aquatic and snow ecosystems, water is the medium in which the ecosystem functions and so its state mediates all transactions in these systems. Ecosystems are not passive responders to water but through their structure and function can manage water and associated microclimate – forests, grasslands, organic terrain wetlands, and beaver ponds being just a few examples.
This chapter will examine the surface water budget in terms of the water continuity equation as a manifestation of the hydrological cycle. To solve the continuity equation for water, the chapter will review hydrological processes and how they interact with vegetation, animals, soils, geomorphology and climate in the context of the catchment. The coupling of the mass and energy continuity equations in controlling hydrological processes will be discussed. How hydrological processes and their ecosystem interactions are managed by humans will be introduced. Then the chapter will review calculation schemes for the surface water budget via one-dimensional land surface schemes and catchment-based hydrological models, noting the data requirements, uncertainty and limitations of these models and the balance required between model complexity and physical representation of hydrology. This will give the conceptual ideas and basic mathematics of conservation laws and transport processes that form the basis of many models in the forthcoming chapters.
Hydrological Processes as a Fundamental Component of Aquatic and Terrestrial Ecosystems
Hydrological Cycle
The hydrological cycle is the flow and storage of water, as liquid, solid or vapor, on and near the Earth's surface. This cycling is a fundamental function of the Earth system and, through its associated latent energy transformations and other influences on land surface characteristics, ensures the habitability of the planet. A representation of the global hydrological cycle is found in Figure 4.1 where it can be seen that there are substantial flows between ocean and land – evaporation and river discharge from land transfer water directly to the oceans or through precipitation and ocean water is evaporated and then forms precipitation over land.
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
- Published online:
- 05 August 2015
- Print publication:
- 27 April 2015, pp ix-xxx
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Genetic ancestry modifies fatty acid concentrations in different adipose tissue depots and milk fat
- Susanne Meier, Gwyneth A Verkerk, Jane K Kay, Kevin A Macdonald, John R Roche
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- Journal:
- Journal of Dairy Research / Volume 80 / Issue 2 / May 2013
- Published online by Cambridge University Press:
- 28 February 2013, pp. 197-204
- Print publication:
- May 2013
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The objective of this study was to determine the effect of cow genetic strain on fatty acid (FA) profiles in adipose tissue and milk. Adipose samples from two subcutaneous (shoulder and tail-head) and three visceral (kidney channel, mesenteric and omental) depots were obtained post mortem from New Zealand (NZ; n = 8) and North American (NA; n = 8) Holstein–Friesian cows. At the time of slaughter cows were in similar body condition (NZ: 4·0 ± 0·03, NA: 4·0 ± 0·02; ±sd) and stage of lactation (NZ: 90 ± 11·2 d; NA: 83 ± 4·3 d; ±sd). Milk was collected during the a.m. milking prior to slaughter and milk fat was extracted. Adipose and milk fat FA were quantified using gas chromatography. NZ cows had a lower proportion of saturated FA in shoulder, tail-head and omental adipose tissue and a greater proportion of mono-unsaturated FA and an elevated Δ9-desaturase index in shoulder and tail-head adipose tissue. The proportions of individual FA differed between adipose depots, with proportions of de-novo FA greater in subcutaneous compared with visceral adipose depots. Milk from NZ cows contained greater concentrations of short chain FA (C8 : 0–12 : 0) and CLA, and less cis-9 18 : 1 than milk from NA cows. Regression analysis identified moderate associations between milk FA and shoulder adipose tissue FA for 18 : 2 (R2 = 0·24), 18 : 3 n − 3 (R2 = 0·39), and polyunsaturated fatty acids (R2 = 0·38). Results from this study support the hypothesis that genetic strain dictates FA profiles in adipose tissue and milk and may alter the metabolic status of the various adipose depots differently. The data further support the premise that genetic strain affects the metabolic status of the various adipose depots differently. Elucidating the mechanisms that regulate the different adipose depots in the NZ and NA strains will increase our understanding of tissue mobilization and replenishment.
Occupational Injuries and Exposures Among Canadian Dentists: The Results of a National Survey
- Gillian M. McCarthy, John J. Koval, John K. MacDonald
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- Journal:
- Infection Control & Hospital Epidemiology / Volume 20 / Issue 5 / May 1999
- Published online by Cambridge University Press:
- 02 January 2015, pp. 331-336
- Print publication:
- May 1999
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Objectives:
To measure the frequency of occupational exposures reported by dentists in Canada and to identify factors associated with occupational exposure.
Design:A national mailed survey of a stratified random sample of 6,444 dentists with three follow-up attempts. Weighted data were analyzed using t tests, analysis of variance, and multiple logistic regression.
Results:The response rate was approximately 66%. Occupational exposures, percutaneous injuries, and mucous membrane exposures in the last year were reported by 67%, 62%, and 29% of respondents, respectively. Fewer than 1% reported exposure to human immunodeficiency virus or hepatitis B virus (HBV). Respondents reported means of 1.5 mucous membrane and 3.0 percutaneous exposures per year. HBV immunization was reported by 91% of dentists, but of these 28% reported no post-immunization serology. Other reports of suboptimal compliance included use of a postexposure protocol by only 41% and HBV vaccination of all assistants or of hygienists by 74% and 77% of respondents, respectively. Factors associated with percutaneous exposure included non-use of postexposure protocol or puncture-proof containers for sharps disposal, treating ⩾20 patients per day, and male gender. Risk factors for mucous membrane exposure included non-use of eye protection or masks.
Conclusion:This study provides evidence of the protective effect of puncture-proof containers, eye protection, and masks and raises concerns related to HBV post-immunization serology and postexposure protocols. To reduce risk of infection, educational interventions are required to improve compliance with Universal Precautions, with emphasis on comprehensive HBV immunization and post-immunization serology, the use of barriers, puncture-proof containers for sharps disposal, and postexposure protocols.
The authors reply
- Gillian M. McCarthy, John K. MacDonald
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- Journal:
- Infection Control & Hospital Epidemiology / Volume 19 / Issue 12 / December 1998
- Published online by Cambridge University Press:
- 02 January 2015, pp. 888-889
- Print publication:
- December 1998
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The Infection Control Practices of General Dental Practitioners
- Gillian M. McCarthy, John K. MacDonald
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- Journal:
- Infection Control & Hospital Epidemiology / Volume 18 / Issue 10 / October 1997
- Published online by Cambridge University Press:
- 02 January 2015, pp. 699-703
- Print publication:
- October 1997
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Objectives:
To investigate the infection control practices of general dentists in Ontario in 1994.
Design:Confidential coded questionnaires were mailed to all general dental practitioners in Ontario (n=5,176), with three follow-up attempts. Data were analyzed using Pearson's chi-squared test and multiple logistic regression.
Setting:Offices of general dental practitioners in Ontario.
Participants:General dental practitioners actively involved in treating patients.
Results:The response rate adjusted for nondelivery was 70%. A high proportion of respondents reported using gloves (always, 91.8%; sometimes, 7.8%), masks (always, 74.8%; sometimes, 21.1%), or protective eyewear (always, 83.6%; sometimes, 13%); heat sterilization of hand-pieces (83.9%); and hepatitis B (HBV) vaccination of dentists (92.3%). However, only 61.4% of respondents reported HBV vaccination of all clinical staff, and 87.7% used additional precautions for patients with human immunodeficiency virus (HIV). Significant predictors of the use of recommended infection control procedures (ie, always using gloves, masks, and eye protection; heat sterilization of handpieces; HBV vaccination for dentist and staff; and no extra precautions for patients with HIV) were age ?40 years (odds ratio [OR], 2.6), lack of concern regarding increased personal risk (OR, 2.0) or costs of infection control procedures (OR, 1.5), and knowledge of the low infectivity of HIV after a needlestick injury (OR, 2.0) and that infection control procedures for HBV are adequate for HIV (OR, 2.7).
Conclusion:Additional education is required to promote a more realistic perception of risk of HIV transmission in the dental office and the use of all recommended infection control practices, including Universal Precautions.
The Scottish First Episode Schizophrenia Study: VI. Computerised Tomography Brain Scans in Patients and Controls
- H. L. MacDonald, J. J. K. Best, The Scottish Schizophrenia Research Group, Robin G. McCreadie, David H. Wiles, Stewart M. Grant, John W. Moore, George T. Crocket, Zahid Mahmood, Martin G. Livingston, James A. G. Watt, J. G. Greene, Peter W. Kershaw, Norman A. Todd, Angus M. Scott, James A. T. Dyer, John Loudon, Alistair E. Philip, David Batchelor
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- Journal:
- The British Journal of Psychiatry / Volume 154 / Issue 4 / April 1989
- Published online by Cambridge University Press:
- 02 January 2018, pp. 492-498
- Print publication:
- April 1989
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This is the initial report of a prospective study by computerised tomography brain scan of first episode schizophrenia. Twenty-seven patients who met Research Diagnostic Criteria for schizophrenia were compared with volunteer controls on ventricular: brain ratio, sulcal: brain volume ratio, and the widths of third ventricle and Sylvian and interhemispheric fissures. The results provide evidence that sulcal enlargement, but not ventricular abnormalities, may be detected at first admission for schizophrenic illness, and are discussed in relation to findings from other studies.