55 results
Infants with pulmonary atresia intact ventricular septum who require balloon atrial septostomy have significantly higher 18-month mortality
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- Nicole L Herrick, Asimina Courelli, Jesse W Lee, Kanishka Ratnayaka, Laith I Alshawabkeh, John W Moore, Howaida G El-Said
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- Journal:
- Cardiology in the Young / Volume 31 / Issue 10 / October 2021
- Published online by Cambridge University Press:
- 01 March 2021, pp. 1613-1618
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Introduction:
Many newborns with pulmonary atresia/intact ventricular septum require intervention to establish pulmonary flow and sufficient cardiac output. The resulting haemodynamic changes are not well characterised and may have unintended consequences.
Methods:This is a 30-year (1988–2018) retrospective study of patients with pulmonary atresia intact ventricular septum.
Results:Eighty-nine patients were included, and median follow-up was 8 years. Fifty-five per cent had coronary sinusoids and 27% had right ventricular-dependent coronary circulation. Most patients were managed with surgical aortopulmonary or modified Blalock–Taussig shunt (73%), and 12 patients underwent balloon atrial septostomy before surgical intervention. The remaining patients (27%) underwent only transcatheter interventions; 7 required an atrial septostomy and 17 required ductal stentings. All-cause mortality was 10%, most deaths (89%) occurred before 18 months of age. Of these early deaths, 87% required a balloon atrial septostomy and 85% had right ventricular-dependent coronary sinusoids. Eighteen-month mortality was significantly higher for patients who required a balloon atrial septostomy compared to those who did not (36% versus 1.4% p < 0.0001).
Discussion:Patients with pulmonary atresia/intact ventricular septum who require balloon atrial septostomy in the newborn period have significantly higher 18-month mortality. Quantifying the mortality difference may help guide prognostication and expectation setting. Infants who had septostomy and a surgical shunt in the newborn period fared better than those who only underwent septostomy (even when accompanied by ductal stenting). For infants with right ventricular-dependent circulation, atrial septostomy should only be performed on an urgent or emergent basis and these patients should be considered for early surgical intervention and neonatal transplant.
Socio-demographic and trauma-related predictors of depression within eight weeks of motor vehicle collision in the AURORA study
- Jutta Joormann, Samuel A. McLean, Francesca L. Beaudoin, Xinming An, Jennifer S. Stevens, Donglin Zeng, Thomas C. Neylan, Gari Clifford, Sarah D. Linnstaedt, Laura T. Germine, Scott L. Rauch, Paul I. Musey, Phyllis L. Hendry, Sophia Sheikh, Christopher W. Jones, Brittany E. Punches, Gregory Fermann, Lauren A. Hudak, Kamran Mohiuddin, Vishnu Murty, Meghan E. McGrath, John P. Haran, Jose Pascual, Mark Seamon, David A. Peak, Claire Pearson, Robert M. Domeier, Paulina Sergot, Roland Merchant, Leon D. Sanchez, Niels K. Rathlev, William F. Peacock, Steven E. Bruce, Deanna Barch, Diego A. Pizzagalli, Beatriz Luna, Steven E. Harte, Irving Hwang, Sue Lee, Nancy Sampson, Karestan C. Koenen, Kerry J. Ressler, Ronald C. Kessler
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- Journal:
- Psychological Medicine / Volume 52 / Issue 10 / July 2022
- Published online by Cambridge University Press:
- 29 October 2020, pp. 1934-1947
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Background
This is the first report on the association between trauma exposure and depression from the Advancing Understanding of RecOvery afteR traumA(AURORA) multisite longitudinal study of adverse post-traumatic neuropsychiatric sequelae (APNS) among participants seeking emergency department (ED) treatment in the aftermath of a traumatic life experience.
MethodsWe focus on participants presenting at EDs after a motor vehicle collision (MVC), which characterizes most AURORA participants, and examine associations of participant socio-demographics and MVC characteristics with 8-week depression as mediated through peritraumatic symptoms and 2-week depression.
ResultsEight-week depression prevalence was relatively high (27.8%) and associated with several MVC characteristics (being passenger v. driver; injuries to other people). Peritraumatic distress was associated with 2-week but not 8-week depression. Most of these associations held when controlling for peritraumatic symptoms and, to a lesser degree, depressive symptoms at 2-weeks post-trauma.
ConclusionsThese observations, coupled with substantial variation in the relative strength of the mediating pathways across predictors, raises the possibility of diverse and potentially complex underlying biological and psychological processes that remain to be elucidated in more in-depth analyses of the rich and evolving AURORA database to find new targets for intervention and new tools for risk-based stratification following trauma exposure.
Education in Twins and Their Parents Across Birth Cohorts Over 100 years: An Individual-Level Pooled Analysis of 42-Twin Cohorts
- Karri Silventoinen, Aline Jelenkovic, Antti Latvala, Reijo Sund, Yoshie Yokoyama, Vilhelmina Ullemar, Catarina Almqvist, Catherine A. Derom, Robert F. Vlietinck, Ruth J. F. Loos, Christian Kandler, Chika Honda, Fujio Inui, Yoshinori Iwatani, Mikio Watanabe, Esther Rebato, Maria A. Stazi, Corrado Fagnani, Sonia Brescianini, Yoon-Mi Hur, Hoe-Uk Jeong, Tessa L. Cutler, John L. Hopper, Andreas Busjahn, Kimberly J. Saudino, Fuling Ji, Feng Ning, Zengchang Pang, Richard J. Rose, Markku Koskenvuo, Kauko Heikkilä, Wendy Cozen, Amie E. Hwang, Thomas M. Mack, Sisira H. Siribaddana, Matthew Hotopf, Athula Sumathipala, Fruhling Rijsdijk, Joohon Sung, Jina Kim, Jooyeon Lee, Sooji Lee, Tracy L. Nelson, Keith E. Whitfield, Qihua Tan, Dongfeng Zhang, Clare H. Llewellyn, Abigail Fisher, S. Alexandra Burt, Kelly L. Klump, Ariel Knafo-Noam, David Mankuta, Lior Abramson, Sarah E. Medland, Nicholas G. Martin, Grant W. Montgomery, Patrik K. E. Magnusson, Nancy L. Pedersen, Anna K. Dahl Aslan, Robin P. Corley, Brooke M. Huibregtse, Sevgi Y. Öncel, Fazil Aliev, Robert F. Krueger, Matt McGue, Shandell Pahlen, Gonneke Willemsen, Meike Bartels, Catharina E. M. van Beijsterveldt, Judy L. Silberg, Lindon J. Eaves, Hermine H. Maes, Jennifer R. Harris, Ingunn Brandt, Thomas S. Nilsen, Finn Rasmussen, Per Tynelius, Laura A. Baker, Catherine Tuvblad, Juan R. Ordoñana, Juan F. Sánchez-Romera, Lucia Colodro-Conde, Margaret Gatz, David A. Butler, Paul Lichtenstein, Jack H. Goldberg, K. Paige Harden, Elliot M. Tucker-Drob, Glen E. Duncan, Dedra Buchwald, Adam D. Tarnoki, David L. Tarnoki, Carol E. Franz, William S. Kremen, Michael J. Lyons, José A. Maia, Duarte L. Freitas, Eric Turkheimer, Thorkild I. A. Sørensen, Dorret I. Boomsma, Jaakko Kaprio
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- Twin Research and Human Genetics / Volume 20 / Issue 5 / October 2017
- Published online by Cambridge University Press:
- 04 October 2017, pp. 395-405
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Whether monozygotic (MZ) and dizygotic (DZ) twins differ from each other in a variety of phenotypes is important for genetic twin modeling and for inferences made from twin studies in general. We analyzed whether there were differences in individual, maternal and paternal education between MZ and DZ twins in a large pooled dataset. Information was gathered on individual education for 218,362 adult twins from 27 twin cohorts (53% females; 39% MZ twins), and on maternal and paternal education for 147,315 and 143,056 twins respectively, from 28 twin cohorts (52% females; 38% MZ twins). Together, we had information on individual or parental education from 42 twin cohorts representing 19 countries. The original education classifications were transformed to education years and analyzed using linear regression models. Overall, MZ males had 0.26 (95% CI [0.21, 0.31]) years and MZ females 0.17 (95% CI [0.12, 0.21]) years longer education than DZ twins. The zygosity difference became smaller in more recent birth cohorts for both males and females. Parental education was somewhat longer for fathers of DZ twins in cohorts born in 1990–1999 (0.16 years, 95% CI [0.08, 0.25]) and 2000 or later (0.11 years, 95% CI [0.00, 0.22]), compared with fathers of MZ twins. The results show that the years of both individual and parental education are largely similar in MZ and DZ twins. We suggest that the socio-economic differences between MZ and DZ twins are so small that inferences based upon genetic modeling of twin data are not affected.
1 - Xenophon and his Times
- from Part I - Contexts
- Edited by Michael A. Flower, Princeton University, New Jersey
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- The Cambridge Companion to Xenophon
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- 12 January 2017
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- 15 December 2016, pp 15-36
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Twin's Birth-Order Differences in Height and Body Mass Index From Birth to Old Age: A Pooled Study of 26 Twin Cohorts Participating in the CODATwins Project
- Yoshie Yokoyama, Aline Jelenkovic, Reijo Sund, Joohon Sung, John L. Hopper, Syuichi Ooki, Kauko Heikkilä, Sari Aaltonen, Adam D. Tarnoki, David L. Tarnoki, Gonneke Willemsen, Meike Bartels, Toos C. E. M. van Beijsterveldt, Kimberly J. Saudino, Tessa L. Cutler, Tracy L. Nelson, Keith E. Whitfield, Jane Wardle, Clare H. Llewellyn, Abigail Fisher, Mingguang He, Xiaohu Ding, Morten Bjerregaard-Andersen, Henning Beck-Nielsen, Morten Sodemann, Yun-Mi Song, Sarah Yang, Kayoung Lee, Hoe-Uk Jeong, Ariel Knafo-Noam, David Mankuta, Lior Abramson, S. Alexandra Burt, Kelly L. Klump, Juan R. Ordoñana, Juan F. Sánchez-Romera, Lucia Colodro-Conde, Jennifer R. Harris, Ingunn Brandt, Thomas Sevenius Nilsen, Jeffrey M. Craig, Richard Saffery, Fuling Ji, Feng Ning, Zengchang Pang, Lise Dubois, Michel Boivin, Mara Brendgen, Ginette Dionne, Frank Vitaro, Nicholas G. Martin, Sarah E. Medland, Grant W. Montgomery, Patrik K. E. Magnusson, Nancy L. Pedersen, Anna K. Dahl Aslan, Per Tynelius, Claire M. A. Haworth, Robert Plomin, Esther Rebato, Richard J. Rose, Jack H. Goldberg, Finn Rasmussen, Yoon-Mi Hur, Thorkild I. A. Sørensen, Dorret I. Boomsma, Jaakko Kaprio, Karri Silventoinen
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- Twin Research and Human Genetics / Volume 19 / Issue 2 / April 2016
- Published online by Cambridge University Press:
- 09 March 2016, pp. 112-124
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We analyzed birth order differences in means and variances of height and body mass index (BMI) in monozygotic (MZ) and dizygotic (DZ) twins from infancy to old age. The data were derived from the international CODATwins database. The total number of height and BMI measures from 0.5 to 79.5 years of age was 397,466. As expected, first-born twins had greater birth weight than second-born twins. With respect to height, first-born twins were slightly taller than second-born twins in childhood. After adjusting the results for birth weight, the birth order differences decreased and were no longer statistically significant. First-born twins had greater BMI than the second-born twins over childhood and adolescence. After adjusting the results for birth weight, birth order was still associated with BMI until 12 years of age. No interaction effect between birth order and zygosity was found. Only limited evidence was found that birth order influenced variances of height or BMI. The results were similar among boys and girls and also in MZ and DZ twins. Overall, the differences in height and BMI between first- and second-born twins were modest even in early childhood, while adjustment for birth weight reduced the birth order differences but did not remove them for BMI.
Zygosity Differences in Height and Body Mass Index of Twins From Infancy to Old Age: A Study of the CODATwins Project
- Aline Jelenkovic, Yoshie Yokoyama, Reijo Sund, Chika Honda, Leonie H Bogl, Sari Aaltonen, Fuling Ji, Feng Ning, Zengchang Pang, Juan R. Ordoñana, Juan F. Sánchez-Romera, Lucia Colodro-Conde, S. Alexandra Burt, Kelly L. Klump, Sarah E. Medland, Grant W. Montgomery, Christian Kandler, Tom A. McAdams, Thalia C. Eley, Alice M. Gregory, Kimberly J. Saudino, Lise Dubois, Michel Boivin, Adam D. Tarnoki, David L. Tarnoki, Claire M. A. Haworth, Robert Plomin, Sevgi Y. Öncel, Fazil Aliev, Maria A. Stazi, Corrado Fagnani, Cristina D’Ippolito, Jeffrey M. Craig, Richard Saffery, Sisira H. Siribaddana, Matthew Hotopf, Athula Sumathipala, Fruhling Rijsdijk, Timothy Spector, Massimo Mangino, Genevieve Lachance, Margaret Gatz, David A. Butler, Gombojav Bayasgalan, Danshiitsoodol Narandalai, Duarte L Freitas, José Antonio Maia, K. Paige Harden, Elliot M. Tucker-Drob, Bia Kim, Youngsook Chong, Changhee Hong, Hyun Jung Shin, Kaare Christensen, Axel Skytthe, Kirsten O. Kyvik, Catherine A. Derom, Robert F. Vlietinck, Ruth J. F. Loos, Wendy Cozen, Amie E. Hwang, Thomas M. Mack, Mingguang He, Xiaohu Ding, Billy Chang, Judy L. Silberg, Lindon J. Eaves, Hermine H. Maes, Tessa L. Cutler, John L. Hopper, Kelly Aujard, Patrik K. E. Magnusson, Nancy L. Pedersen, Anna K. Dahl Aslan, Yun-Mi Song, Sarah Yang, Kayoung Lee, Laura A. Baker, Catherine Tuvblad, Morten Bjerregaard-Andersen, Henning Beck-Nielsen, Morten Sodemann, Kauko Heikkilä, Qihua Tan, Dongfeng Zhang, Gary E. Swan, Ruth Krasnow, Kerry L. Jang, Ariel Knafo-Noam, David Mankuta, Lior Abramson, Paul Lichtenstein, Robert F. Krueger, Matt McGue, Shandell Pahlen, Per Tynelius, Glen E. Duncan, Dedra Buchwald, Robin P. Corley, Brooke M. Huibregtse, Tracy L. Nelson, Keith E. Whitfield, Carol E. Franz, William S. Kremen, Michael J. Lyons, Syuichi Ooki, Ingunn Brandt, Thomas Sevenius Nilsen, Fujio Inui, Mikio Watanabe, Meike Bartels, Toos C. E. M. van Beijsterveldt, Jane Wardle, Clare H. Llewellyn, Abigail Fisher, Esther Rebato, Nicholas G. Martin, Yoshinori Iwatani, Kazuo Hayakawa, Joohon Sung, Jennifer R. Harris, Gonneke Willemsen, Andreas Busjahn, Jack H. Goldberg, Finn Rasmussen, Yoon-Mi Hur, Dorret I. Boomsma, Thorkild I. A. Sørensen, Jaakko Kaprio, Karri Silventoinen
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- Journal:
- Twin Research and Human Genetics / Volume 18 / Issue 5 / October 2015
- Published online by Cambridge University Press:
- 04 September 2015, pp. 557-570
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A trend toward greater body size in dizygotic (DZ) than in monozygotic (MZ) twins has been suggested by some but not all studies, and this difference may also vary by age. We analyzed zygosity differences in mean values and variances of height and body mass index (BMI) among male and female twins from infancy to old age. Data were derived from an international database of 54 twin cohorts participating in the COllaborative project of Development of Anthropometrical measures in Twins (CODATwins), and included 842,951 height and BMI measurements from twins aged 1 to 102 years. The results showed that DZ twins were consistently taller than MZ twins, with differences of up to 2.0 cm in childhood and adolescence and up to 0.9 cm in adulthood. Similarly, a greater mean BMI of up to 0.3 kg/m2 in childhood and adolescence and up to 0.2 kg/m2 in adulthood was observed in DZ twins, although the pattern was less consistent. DZ twins presented up to 1.7% greater height and 1.9% greater BMI than MZ twins; these percentage differences were largest in middle and late childhood and decreased with age in both sexes. The variance of height was similar in MZ and DZ twins at most ages. In contrast, the variance of BMI was significantly higher in DZ than in MZ twins, particularly in childhood. In conclusion, DZ twins were generally taller and had greater BMI than MZ twins, but the differences decreased with age in both sexes.
The CODATwins Project: The Cohort Description of Collaborative Project of Development of Anthropometrical Measures in Twins to Study Macro-Environmental Variation in Genetic and Environmental Effects on Anthropometric Traits
- Karri Silventoinen, Aline Jelenkovic, Reijo Sund, Chika Honda, Sari Aaltonen, Yoshie Yokoyama, Adam D. Tarnoki, David L. Tarnoki, Feng Ning, Fuling Ji, Zengchang Pang, Juan R. Ordoñana, Juan F. Sánchez-Romera, Lucia Colodro-Conde, S. Alexandra Burt, Kelly L. Klump, Sarah E. Medland, Grant W. Montgomery, Christian Kandler, Tom A. McAdams, Thalia C. Eley, Alice M. Gregory, Kimberly J. Saudino, Lise Dubois, Michel Boivin, Claire M. A. Haworth, Robert Plomin, Sevgi Y. Öncel, Fazil Aliev, Maria A. Stazi, Corrado Fagnani, Cristina D’Ippolito, Jeffrey M. Craig, Richard Saffery, Sisira H. Siribaddana, Matthew Hotopf, Athula Sumathipala, Timothy Spector, Massimo Mangino, Genevieve Lachance, Margaret Gatz, David A. Butler, Gombojav Bayasgalan, Danshiitsoodol Narandalai, Duarte L. Freitas, José Antonio Maia, K. Paige Harden, Elliot M. Tucker-Drob, Kaare Christensen, Axel Skytthe, Kirsten O. Kyvik, Changhee Hong, Youngsook Chong, Catherine A. Derom, Robert F. Vlietinck, Ruth J. F. Loos, Wendy Cozen, Amie E. Hwang, Thomas M. Mack, Mingguang He, Xiaohu Ding, Billy Chang, Judy L. Silberg, Lindon J. Eaves, Hermine H. Maes, Tessa L. Cutler, John L. Hopper, Kelly Aujard, Patrik K. E. Magnusson, Nancy L. Pedersen, Anna K. Dahl Aslan, Yun-Mi Song, Sarah Yang, Kayoung Lee, Laura A. Baker, Catherine Tuvblad, Morten Bjerregaard-Andersen, Henning Beck-Nielsen, Morten Sodemann, Kauko Heikkilä, Qihua Tan, Dongfeng Zhang, Gary E. Swan, Ruth Krasnow, Kerry L. Jang, Ariel Knafo-Noam, David Mankuta, Lior Abramson, Paul Lichtenstein, Robert F. Krueger, Matt McGue, Shandell Pahlen, Per Tynelius, Glen E. Duncan, Dedra Buchwald, Robin P. Corley, Brooke M. Huibregtse, Tracy L. Nelson, Keith E. Whitfield, Carol E. Franz, William S. Kremen, Michael J. Lyons, Syuichi Ooki, Ingunn Brandt, Thomas Sevenius Nilsen, Fujio Inui, Mikio Watanabe, Meike Bartels, Toos C. E. M. van Beijsterveldt, Jane Wardle, Clare H. Llewellyn, Abigail Fisher, Esther Rebato, Nicholas G. Martin, Yoshinori Iwatani, Kazuo Hayakawa, Finn Rasmussen, Joohon Sung, Jennifer R. Harris, Gonneke Willemsen, Andreas Busjahn, Jack H. Goldberg, Dorret I. Boomsma, Yoon-Mi Hur, Thorkild I. A. Sørensen, Jaakko Kaprio
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- Journal:
- Twin Research and Human Genetics / Volume 18 / Issue 4 / August 2015
- Published online by Cambridge University Press:
- 27 May 2015, pp. 348-360
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For over 100 years, the genetics of human anthropometric traits has attracted scientific interest. In particular, height and body mass index (BMI, calculated as kg/m2) have been under intensive genetic research. However, it is still largely unknown whether and how heritability estimates vary between human populations. Opportunities to address this question have increased recently because of the establishment of many new twin cohorts and the increasing accumulation of data in established twin cohorts. We started a new research project to analyze systematically (1) the variation of heritability estimates of height, BMI and their trajectories over the life course between birth cohorts, ethnicities and countries, and (2) to study the effects of birth-related factors, education and smoking on these anthropometric traits and whether these effects vary between twin cohorts. We identified 67 twin projects, including both monozygotic (MZ) and dizygotic (DZ) twins, using various sources. We asked for individual level data on height and weight including repeated measurements, birth related traits, background variables, education and smoking. By the end of 2014, 48 projects participated. Together, we have 893,458 height and weight measures (52% females) from 434,723 twin individuals, including 201,192 complete twin pairs (40% monozygotic, 40% same-sex dizygotic and 20% opposite-sex dizygotic) representing 22 countries. This project demonstrates that large-scale international twin studies are feasible and can promote the use of existing data for novel research purposes.
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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- 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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Psychoticism and Paranoid Ideation in Patients With Nonpsychotic Major Depressive Disorder: Prevalence, Response to Treatment, and Impact on Short- and Long-Term Treatment Outcome
- Christina M. Dording, David Mischoulon, Tracie M. Goodness, Lee Baer, Alisabet Clain, Jonathan W. Stewart, John D. Matthews, Patrick J. McGrath, Andrew A. Nierenberg, Maurizio Fava, George I. Papakostas
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- CNS Spectrums / Volume 15 / Issue 8 / August 2010
- Published online by Cambridge University Press:
- 07 November 2014, pp. 515-521
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Objective/Introduction: We sought to characterize the impact of the 90-item Symptom Checklist (SCL-90) subscales for paranoid ideation (PI) and psychoticism (P) in patients with major depressive disorder (MDD), on acute anti-depressant response and on relapse prevention.
Methods: Subjects with Structured Clinical Interview for DSM Disorders-diagnosed non-psychotic MDD were recruited into a clinical trial of open-label fluoxetine 10–60 mg/day for 12 weeks, followed by double-blind randomization of responders (n=262) to fluoxetine continuation or placebo for 12 months. PI and P were assessed with the patient-rated SCL-90. The association of these symptoms with response to treatment was assessed by logistic regression.
Results: We found significant decreases in PI and P during acute treatment phase for fluoxetine responders and nonresponders, although only 10.3% and 7.5% of patients experienced a ≥50% reduction in PI and P scores, respectively. Neither PI nor P scores significantly predicted time to relapse. P scores predicted a lower response rate to treatment with fluoxetine.
Discussion: The results of the present study suggest that there is a significant relationship between the presence of psychoticism in patients with nonpsychotic MDD, and the likelihood of overall depressive symptom improvement following a trial of monotherapy with fluoxetine.
Conclusion: An increased burden of psychoticism in depressed subjects may confer poorer response to fluoxetine, but not increased risk of relapse among fluoxetine responders.
Contributors
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- By Robert C. Basner, Carl Bazil, Lee J. Brooks, Sean M. Caples, Kelly A. Carden, Ronald D. Chervin, Christopher Cielo, David G. Davila, Katherine A. Dudley, Judy Fetterolf, W. Ward Flemons, Neil Freedman, Christian Guilleminault, Fauziya Hassan, Shelley Hershner, David M. Hiestand, Mithri Junna, Kristen Kelly-Pieper, Douglas Kirsch, Brian B. Koo, Carin Lamm, Raman Malhotra, Meghna P. Mansukhani, Carole L. Marcus, B. Marshall, Jean K. Matheson, Timothy I. Morgenthaler, Gökhan M. Mutlu, Irina Ok, Vidya Pai, Winnie C. Pao, Sairam Parthasarathy, Shalini Paruthi, Nimesh Patel, Sachin R. Pendharkar, Ravi K. Persaud, Bharati Prasad, Stuart F. Quan, Satish C. Rao, Patti Reed, Alcibiades Rodriguez, Dennis Rosen, Vijay Seelall, Anita Valanju Shelgikar, Jeffrey J. Stanley, Kingman Strohl, Shannon S. Sullivan, Kevin A. Thomas, Robert Thomas, John R. Wheatley, Lisa Wolfe, Peter J.-C. Wu, Motoo Yamauchi
- Edited by Robert C. Basner
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- Case Studies in Polysomnography Interpretation
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- 05 August 2015
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- 18 October 2012, pp x-xii
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Contributors
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- By Kumar Alagappan, Janet G. Alteveer, Kim Askew, Paul S. Auerbach, Katherine Bakes, Kip Benko, Paul D. Biddinger, Victoria Brazil, Anthony FT Brown, Andrew K. Chang, Alice Chiao, Wendy C. Coates, Jamie Collings, Gilbert Abou Dagher, Jonathan E. Davis, Peter DeBlieux, Alessandro Dellai, Emily Doelger, Pamela L. Dyne, Gino Farina, Robert Galli, Gus M. Garmel, Daniel Garza, Laleh Gharahbaghian, Gregory H. Gilbert, Michael A. Gisondi, Steven Go, Jeffrey M. Goodloe, Swaminatha V. Gurudevan, Micelle J. Haydel, Stephen R. Hayden, Corey R. Heitz, Gregory W. Hendey, Mel Herbert, Cherri Hobgood, Michelle Huston, Loretta Jackson-Williams, Anja K. Jaehne, Mary Beth Johnson, H. Brendan Kelleher, Peter G Kumasaka, Melissa J. Lamberson, Mary Lanctot-Herbert, Erik Laurin, Brian Lin, Michelle Lin, Douglas Lowery-North, Sharon E. Mace, S. V. Mahadevan, Thomas M. Mailhot, Diku Mandavia, David E. Manthey, Jorge A. Martinez, Amal Mattu, Lynne McCullough, Steve McLaughlin, Timothy Meyers, Gregory J. Moran, Randall T. Myers, Christopher R.H. Newton, Flavia Nobay, Robert L. Norris, Catherine Oliver, Jennifer A. Oman, Rita Oregon, Phillips Perera, Susan B. Promes, Emanuel P. Rivers, John S. Rose, Carolyn J. Sachs, Jairo I. Santanilla, Rawle A. Seupaul, Fred A. Severyn, Ghazala Q. Sharieff, Lee W. Shockley, Stefanie Simmons, Barry C. Simon, Shannon Sovndal, George Sternbach, Matthew Strehlow, Eustacia (Jo) Su, Stuart P. Swadron, Jeffrey A. Tabas, Sophie Terp, R. Jason Thurman, David A. Wald, Sarah R. Williams, Teresa S. Wu, Ken Zafren
- Edited by S. V. Mahadevan, Stanford University School of Medicine, California, Gus M. Garmel
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- An Introduction to Clinical Emergency Medicine
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- 05 May 2012
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- 10 April 2012, pp xi-xvi
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Contributors
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- By Yasir Abu-Omar, Matthew E. Atkins, Joseph E. Arrowsmith, Alan Ashworth, Rubia Baldassarri, Craig R. Bailey, David J. Barron, Christiana C. Burt, David Cardone, Coralie Carle, Jose Coddens, Alan M. Cohen, Simon Colah, Sarah Conolly, David J. Daly, Helen M. Daly, Stefan G. De Hert, Ravi J. De Silva, Mark Dougherty, John J. Dunning, Maros Elsik, Betsy Evans, Florian Falter, Nigel Farnum, Jens Fassl, Juliet E. Foweraker, Simon P. Fynn, Andrew I. Gardner, Margaret I. Gillham, Martin J. Goddard, Maximilien J. Gourdin, Jon Graham, Stephen J. Gray, Cameron Graydon, Fabio Guarracino, Roger M. O. Hall, Michael Haney, Charles W. Hogue, Ben W. Howes, Bevan Hughes, Siân I. Jaggar, David P. Jenkins, Jörn Karhausen, Todd Kiefer, Khalid Khan, Andrew A. Klein, John D. Kneeshaw, Andrew C. Knowles, Catherine V. Koffel, R. Clive Landis, Trevor W. R. Lee, Clive J. Lewis, Jonathan H. Mackay, Amod Manocha, Jonathan B. Mark, Sarah Marstin, William T. McBride, Kenneth H. McKinlay, Alan F. Merry, Berend Mets, Britta Millhoff, Kevin P. Morris, Samer A. M. Nashef, Andrew Neitzel, Stephane Noble, Rabi Panigrahi, Barbora Parizkova, J. M. Tom Pierce, Mihai V. Podgoreanu, Hans-Joachim Priebe, Paul Quinton, C. Ramaswamy Rajamohan, Doris M. Rassl, Tom Rawlings, Fiona E. Reynolds, Andrew J. Richardson, David Riddington, Andrew Roscoe, Paul H. M. Sadleir, Ving Yuen See Tho, Herve Schlotterbeck, Maura Screaton, Shitalkumar Shah, Harjot Singh, Jon H. Smith, M. L. Srikanth, Yeewei W. Teo, Kamen P. Valchanov, Jean-Pierre van Besouw, Isabeau A. Walker, Stephen T. Webb, Francis C. Wells, John Whitbread, Charles Willmott, Patrick Wouters
- Edited by Jonathan H. Mackay, Joseph E. Arrowsmith
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- Core Topics in Cardiac Anesthesia
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- 05 April 2012
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- 15 March 2012, pp x-xiii
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Acronyms
- Michael I. Friswell, Swansea University, John E. T. Penny, Aston University, Seamus D. Garvey, University of Nottingham, Arthur W. Lees, Swansea University
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- Dynamics of Rotating Machines
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- 05 February 2015
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- 31 March 2010, pp xv-xvi
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9 - Axial and Torsional Vibration
- Michael I. Friswell, Swansea University, John E. T. Penny, Aston University, Seamus D. Garvey, University of Nottingham, Arthur W. Lees, Swansea University
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- Dynamics of Rotating Machines
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- 05 February 2015
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- 31 March 2010, pp 383-419
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Summary
Introduction
In Chapter 1, it is noted that the dynamic behavior of many rotors can be divided into three different classes: lateral, axial, and torsional. This chapter addresses both the axial and torsional behaviors of rotors. Generally, these two categories of behavior do not interact with one another, except in worm drives and bevel gears. Treating axial and torsional behavior together is justifiable because, mathematically, they are close analogies of one another. For cyclically symmetrical rotors, the analysis of both axial and torsional behavior is relatively simple. Thus, it is possible to provide an overview treatment of both in the space of a single chapter.
The degree to which a single rotor can be analyzed in isolation is different for the three classes of vibration. Lateral vibrations of a rotor are usually strongly coupled to the vibrations of the supporting stator and structure. The only significant exception to this is where very flexible bearings are in use. Passive magnetic bearings often provide this condition. By contrast, there is usually little coupling between torsional or axial vibrations of a rotor and any motion of the stator, except in the case of a geared system. Although this fact is helpful in analyzing the rotor, it often has the undesirable effect that even very severe torsional or axial vibrations in a rotor easily may go undetected by vibration probes on the stator. The analysis of torsional behavior is often carried out for a complete shaft train, whereas it is sometimes possible to analyze separately the axial and lateral behavior of the individual rotors in a shaft train.
Frontmatter
- Michael I. Friswell, Swansea University, John E. T. Penny, Aston University, Seamus D. Garvey, University of Nottingham, Arthur W. Lees, Swansea University
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- Dynamics of Rotating Machines
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8 - Balancing
- Michael I. Friswell, Swansea University, John E. T. Penny, Aston University, Seamus D. Garvey, University of Nottingham, Arthur W. Lees, Swansea University
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- Dynamics of Rotating Machines
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- 05 February 2015
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- 31 March 2010, pp 339-382
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Summary
Introduction
In all rotating machinery, some degree of mass unbalance is always present. Chapter 6 shows that small deviations in mass symmetry about the axis of rotation can lead to significant unbalance forces being exerted on the bearings. It is imperative to minimize these forces because they can lead to damaging vibration levels in the rotor, bearings, supporting structure, and ancillary equipment. Mass unbalance also can cause large shaft responses, leading to rotor–stator rubs or high stresses in the rotor. This unbalance is controlled primarily by attention to tolerances in rotor manufacture, but this alone is rarely sufficient and some means of further reducing vibration levels on the complete machine is necessary.
In this chapter, we discuss methods to achieve a satisfactory state of balance for a machine by adjusting the distribution of mass on the rotor, by either adding or removing correction masses at specific locations. Here, we concentrate on how to determine which unbalance corrections are appropriate; we do not focus on how, practically, these corrections are achieved. There are several approaches to the balancing of a rotor and all are based on the assumption of system linearity. Occasionally, iteration is required in the case of machines the bearings of which exhibit some degree of nonlinearity. The fundamental concepts of balancing are to monitor the effect on the synchronous (i.e., 1X) response of the machine due to one or more small masses attached to the rotor and then to scale those influences to determine the extent of the unbalance present in the rotor.
Index
- Michael I. Friswell, Swansea University, John E. T. Penny, Aston University, Seamus D. Garvey, University of Nottingham, Arthur W. Lees, Swansea University
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- Dynamics of Rotating Machines
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- 05 February 2015
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- 31 March 2010, pp 519-526
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Dynamics of Rotating Machines
- Michael I. Friswell, John E. T. Penny, Seamus D. Garvey, Arthur W. Lees
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- Published online:
- 05 February 2015
- Print publication:
- 31 March 2010
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This book equips the reader to understand every important aspect of the dynamics of rotating machines. Will the vibration be large? What influences machine stability? How can the vibration be reduced? Which sorts of rotor vibration are the worst? The book develops this understanding initially using extremely simple models for each phenomenon, in which (at most) four equations capture the behavior. More detailed models are then developed based on finite element analysis, to enable the accurate simulation of the relevant phenomena for real machines. Analysis software (in MATLAB) is associated with this book, and novices to rotordynamics can expect to make good predictions of critical speeds and rotating mode shapes within days. The book is structured more as a learning guide than as a reference tome and provides readers with more than 100 worked examples and more than 100 problems and solutions.
3 - Free Lateral Response of Simple Rotor Models
- Michael I. Friswell, Swansea University, John E. T. Penny, Aston University, Seamus D. Garvey, University of Nottingham, Arthur W. Lees, Swansea University
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- Dynamics of Rotating Machines
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- 05 February 2015
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- 31 March 2010, pp 76-123
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Summary
Introduction
In this chapter, we consider the process of creating adequate models of simple rotor systems and examine their lateral vibration in the absence of any applied forces. By “simple,” we mean a rotor system that can be modeled in terms of a small number of degrees of freedom. These simple models consist of either a rigid rotor on flexible bearings and foundation or a flexible rotor on rigid bearings and foundation. Obviously, rotating machines are not designed specifically with these properties; the reality is that rotating machines are designed for a purpose. Shaft dimensions and inertias and the type and dimensions of the bearings are chosen appropriately for the machine function. It may be that the rotor is short with a large diameter, resulting in a shaft that is much stiffer than the bearing and foundations on which it is supported. In such circumstances, it might well be appropriate to model the system as a rigid rotor on flexible bearings and foundations. In these simple models, we assume that both the bearing and foundation can be represented by simple linear springs in the x and y directions. Therefore, the stiffness of the bearing and foundation can be combined and considered as a single entity, using the formula for the stiffness of springs in series, Equation (2.9). Conversely, a machine design might demand a long shaft supported on relatively stiff rolling-element bearings and a stiff foundation. In this case, the bearing and foundation stiffness relative to the shaft stiffness is very high and it may be acceptable to model the system as a flexible rotor on rigid supports. Both models are studied in this chapter.
1 - Introduction
- Michael I. Friswell, Swansea University, John E. T. Penny, Aston University, Seamus D. Garvey, University of Nottingham, Arthur W. Lees, Swansea University
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- Dynamics of Rotating Machines
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- 05 February 2015
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- 31 March 2010, pp 1-16
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Summary
Overview
The aim of this book is to introduce readers to modern methods of modeling and analyzing rotating machines to determine their dynamic behavior. This is usually referred to as rotordynamics. The text is suitable for final-year undergraduates, postgraduates, and practicing engineers who require both an understanding of modern techniques used to model and analyze rotating systems and an ability to interpret the results of such analyses.
Before presenting a text on the dynamics of rotating machines, it is appropriate to consider why one would wish to study this subject. Apart from academic interest, it is an important practical subject in industry, despite the forbidding appearance of some of the mathematics used. There are two important application areas for the techniques found in the following pages. First, when designing the rotating parts of a machine, it is clearly necessary to consider their dynamic characteristics. It is crucial that the design of a machine is such that while running up to and functioning at its operating speed(s), vibration does not exceed safe and acceptable levels. An unacceptably high level of rotor vibration can cause excessive wear on bearings and may cause seals to fail. Blades on a rotor may come into contact with the stationary housing with disastrous results. An unacceptable level of vibration might be transmitted to the supporting structure and high levels of vibration could generate an excessive noise level. The second aspect of importance is the understanding of a machine's behavior when circumstances change, implying that a fault has occurred in the rotating parts of the machine.