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97 Exploring Urban-Rural Disparities in Alzheimer’s disease: Clinical characterization of a southern Nevada cohort
- Justin B Miller, Christina Wong, Jessica ZK Caldwell, Jeffrey L Cummings, Samantha E John, Jayde Powell, Kaley Brouwers, Jessica Rodrigues, Kimberly Cobos, Raelynn de la Cruz, Aaron Ritter
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- Journal:
- Journal of the International Neuropsychological Society / Volume 29 / Issue s1 / November 2023
- Published online by Cambridge University Press:
- 21 December 2023, pp. 397-399
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Objective:
As the US population ages, the prevalence of Alzheimer’s disease and related dementias (AD/RD) is on the rise. This is especially true in rural America, where mortality rates due to AD/RD are rising faster than in metropolitan areas. To date, however, people living in rural communities are severely underrepresented in aging research. The Nevada Exploratory Alzheimer’s Disease Research Center (NVeADRC) seeks to address this gap. Here, we present preliminary cognitive data from our rural-dwelling cohort, as well as relevant demographic and clinical characteristics.
Participants and Methods:Individuals with normal cognition (NC), mild cognitive impairment (MCI), and dementia due to Alzheimer’s disease (AD) living in rural communities, defined as a rural-urban commuting area (RUCA) code of 4 or higher, were enrolled through either clinic or community outreach. Eligibility for the observational cohort required: age >55 years, primarily English-speaking, primary residence in a rural community, and availability of a study partner. Measures included the Uniform Data Set (v3), blood-based biomarkers, structural brain MRI, and portions of the PhenX Social Determinants of Health toolkit. Participants are seen at baseline and followed annually, with interim remote visits every 6 months. A multidisciplinary consensus diagnosis is rendered after each visit. Where feasible, a harmonized urban cohort followed by the Nevada Center for Neurodegeneration and Translational Neuroscience (CNTN) was used for comparison.
Results:Fifty-six rural-dwelling (age=70.4±7.1 years; edu=15.2±2.6 years; 61% female) and 148 urban-dwelling (age=72.9±6.8 years; edu=15.8±2.7 years; 46% female) older adults were included; age significantly differed between cohorts but education did not. The rural cohort was 46% NC (MoCA=26.8±2.3; CDRsob=0.3±0.6), 32% MCI (MoCA=22.8±3.1; CDRsob=1.2±1.0), and 22% AD (MoCA=16.9±5.5; CDRsob=5.2±3.0). The urban cohort was 39% NC (MoCA=26.4±2.6; CDRsob=0.3±0.8), 44% MCI (MoCA=22.3±3.1; CDRsob=2.0±1.5) and 17% AD (MoCA=18.6±3.9; CDRsob=4.7±2.3). Rural communities were significantly more disadvantaged, as measured by the Area Deprivation Index (ADI), than urban communities (rural ADI=6.3±2.6; urban ADI=3.4±2.3; p<.001). Fifty-percent of the rural cohort lives in a moderate to severely disadvantaged neighborhood (ADI Decile>7) compared to 12% of the urban cohort, and 11% of individuals in the rural cohort reported living more than 30 miles from the nearest medical facility. Across the combined cohort, education was significantly correlated with ADI deciles (r=-.30, p<.001), with people in the areas of highest disadvantage having the lowest education. Verbal memory was also inversely associated with ADI. There were no differences in clinical diagnosis as a function of ADI rank.
Conclusions:Living in a rural community conveys a multifaceted array of risks and benefits, some of which differ from urban settings. The literature to date suggests that older adults living in rural communities are at significantly increased risk for morbidity and mortality due to AD/RD, though it is unclear why. Preliminary data from the NVeADRC show that increasing levels of neighborhood disadvantage were associated with lower levels of education and worse verbal memory in this convenience sample. The combined effect of low education and increased disadvantage account for some of the urban-rural differences in mortality that have been reported, though additional research on representative samples in this underrepresented population is critical.
Ethnic and Immigrant Variations in the Time Trends of Dementia and Parkinsonism
- Jessica J. Wong, Jeffrey C. Kwong, Karen Tu, Debra A. Butt, Andrew S. Wilton, Baiju R. Shah, Brian J. Murray, Alexander Kopp, Hong Chen
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- Journal:
- Canadian Journal of Neurological Sciences / Volume 48 / Issue 6 / November 2021
- Published online by Cambridge University Press:
- 12 January 2021, pp. 779-790
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Objective:
We assessed long-term incidence and prevalence trends of dementia and parkinsonism across major ethnic and immigrant groups in Ontario.
Methods:Linking administrative databases, we established two cohorts (dementia 2001–2014 and parkinsonism 2001–2015) of all residents aged 20 to 100 years with incident diagnosis of dementia (N = 387,937) or parkinsonism (N = 59,617). We calculated age- and sex-standardized incidence and prevalence of dementia and parkinsonism by immigrant status and ethnic groups (Chinese, South Asian, and the General Population). We assessed incidence and prevalence trends using Poisson regression and Cochran–Armitage trend tests.
Results:Across selected ethnic groups, dementia incidence and prevalence were higher in long-term residents than recent or longer-term immigrants from 2001 to 2014. During this period, age- and sex-standardized incidence of dementia in Chinese, South Asian, and the General Population increased, respectively, among longer-term immigrants (by 41%, 58%, and 42%) and long-term residents (28%, 7%, and 4%), and to a lesser degree among recent immigrants. The small number of cases precluded us from assessing parkinsonism incidence trends. For Chinese, South Asian, and the General Population, respectively, prevalence of dementia and parkinsonism modestly increased over time among recent immigrants but significantly increased among longer-term immigrants (dementia: 134%, 217%, and 117%; parkinsonism: 55%, 54%, and 43%) and long-term residents (dementia: 97%, 132%, and 71%; parkinsonism: 18%, 30%, and 29%). Adjustment for pre-existing conditions did not appear to explain incidence trends, except for stroke and coronary artery disease as potential drivers of dementia incidence.
Conclusion:Recent immigrants across major ethnic groups in Ontario had considerably lower rates of dementia and parkinsonism than long-term residents, but this difference diminished with longer-term immigrants.
Fast equilibration dynamics of viscous particle-laden flow in an inclined channel
- Jeffrey Wong, Michael Lindstrom, Andrea L. Bertozzi
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- Journal:
- Journal of Fluid Mechanics / Volume 879 / 25 November 2019
- Published online by Cambridge University Press:
- 19 September 2019, pp. 28-53
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A viscous suspension of negatively buoyant particles released into a wide, open channel on an incline will stratify in the normal direction as it flows. We model the early dynamics of this stratification under the effects of sedimentation and shear-induced migration. Prior work focuses on the behaviour after equilibration where the bulk suspension either separates into two distinct fronts (settled) or forms a single, particle-laden front (ridged), depending on whether the initial concentration of particles exceeds a critical threshold. From past experiments, it is also clear that this equilibration time scale grows considerably near the critical concentration. This paper models the approach to equilibrium. We present a theory of the dramatic growth in this equilibration time when the mixture concentration is near the critical value, where the balance between settling and shear-induced resuspension reverses.
Time Trends of the Incidence, Prevalence, and Mortality of Parkinsonism
- Jessica J. Wong, Jeffrey C. Kwong, Karen Tu, Debra A. Butt, Ray Copes, Andrew S. Wilton, Brian J. Murray, Alexander Kopp, Hong Chen
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- Journal:
- Canadian Journal of Neurological Sciences / Volume 46 / Issue 2 / March 2019
- Published online by Cambridge University Press:
- 28 January 2019, pp. 184-191
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Objectives: We assessed trends in the incidence, prevalence, and post-diagnosis mortality of parkinsonism in Ontario, Canada over 18 years. We also explored the influence of a range of risk factors for brain health on the trend of incident parkinsonism. Methods: We established an open cohort by linking population-based health administrative databases from 1996 to 2014 in Ontario. The study population comprised residents aged 20–100 years with an incident diagnosis of parkinsonism ascertained using a validated algorithm. We calculated age- and sex-standardized incidence, prevalence, and mortality of parkinsonism, stratified by young onset (20–39 years) and mid/late onset (≥40 years). We assessed trends in incidence using Poisson regression, mortality using negative binomial regression, and prevalence of parkinsonism and pre-existing conditions (e.g., head injury) using the Cochran–Armitage trend test. To better understand trends in the incidence of mid/late-onset parkinsonism, we adjusted for various pre-existing conditions in the Poisson regression model. Results: From 1996 to 2014, we identified 73,129 incident cases of parkinsonism (source population of ∼10.5 million), of whom 56% were male, mean age at diagnosis was 72.6 years, and 99% had mid/late-onset parkinsonism. Over 18 years, the age- and sex-standardized incidence decreased by 13.0% for mid/late-onset parkinsonism but remained unchanged for young-onset parkinsonism. The age- and sex-standardized prevalence increased by 22.8%, while post-diagnosis mortality decreased by 5.5%. Adjustment for pre-existing conditions did not appreciably explain the declining incidence of mid/late-onset parkinsonism. Conclusion: Young-onset and mid/late-onset parkinsonism exhibited differing trends in incidence over 18 years in Ontario. Further research to identify other factors that may appreciably explain trends in incident parkinsonism is warranted.
2052: Empirical assessment of a theatrical performance on attitudes and behavior intentions toward research: The informed consent play
- Erin Rothwell, Gretchen Case, Sydney Cheek-O’Donnell, Bob Wong, Erin Johnson, Trent Matheson, Alena Wilson, Nicole R. Robinson, Jared Rawlings, Brooke Horejsi, Jeffrey R. Botkin, Carrie L. Byington
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- Journal:
- Journal of Clinical and Translational Science / Volume 1 / Issue S1 / September 2017
- Published online by Cambridge University Press:
- 10 May 2018, p. 53
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OBJECTIVES/SPECIFIC AIMS: Exposure to theatrical performances holds promise for addressing bioethical issues, but there has been little empirical examination of the impact of dramatic presentation on audiences’ attitudes. This study assessed the short-term impact of the play, Informed Consent, on perceptions of trust, willingness to donate biospecimens, attitudes toward harm and privacy among the general public and in faculty, medical and undergraduate students within an academic medical center in the intermountain west. METHODS/STUDY POPULATION: Surveys were administered before and after a staged reading of the play by professional actors. Pre and post survey responses were linked for each participant. Survey items included the short form Trust in Medical Researchers, and single item questions about group identity, of genetic testing in children, and willingness to donate biospecimens. In total, 3 additional questions about harm, consent, and ethical investigator behavior as represented in the play were asked in the post survey. In addition, respondents were given the option to answer open-ended questions through email. RESULTS/ANTICIPATED RESULTS: Out of the 481 who attended the play, 421 completed both the pre and post surveys, and 166 participants completed open-ended questions online ~1 week after the play. Across all participants, there were significant declines for Trust in Medical Researchers and for the survey item “is it ethical for genetic testing in children for adult onset conditions,” (p<0.001 for both) following the play. There was a significant increase in agreement to improve group identity protections (p<0.001) and no differences on willingness to donate biospecimens to research (p=0.777). When differences were analyzed by race of the participant, non-White participants (n=68) compared with White participants (n=344) were less willing to donate biospecimens in general (p<0.001). Further, non-White participants’ willingness to donate biospecimens decreased (p=0.049) after viewing the play while the white participants’ willingness to donate was unchanged. Qualitative data provided extensive contextual data supporting these perspectives. DISCUSSION/SIGNIFICANCE OF IMPACT: This is one of the first studies to empirically examine the impact of a theatrical performance on both attitudes and behavioral intentions toward research and clinical research participation. Some attitudes changed following the play performance, but there were no significant differences on intention to donate biospecimens for research overall. Future research can further address the value and impact of theatrical performances and other creative arts as tools to engage the public and investigators in dialogue about the ethical issues and complexities in clinical research and further evaluation of the impact of performances on attitudes about research and ethics. Creative arts may be used to motivate investigators and study participants to confront fundamental questions about research participation and trust.
Randomized controlled trial of emergency department initiated smoking cessation counselling and referral to a community counselling service
- Ka Wai Cheung, Ian WH. Wong, Warren Fingrut, Amy Po Yu Tsai, Sally R. Ke, Shayan Shojaie, Jeffrey R. Brubacher, Lauren C. Stewart, Shannon Erdelyi
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- Journal:
- Canadian Journal of Emergency Medicine / Volume 20 / Issue 4 / July 2018
- Published online by Cambridge University Press:
- 11 July 2017, pp. 556-564
- Print publication:
- July 2018
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Objective
Worldwide, tobacco smoke is still the leading cause of preventable morbidity and mortality. Many smokers develop chronic smoking-related conditions that require emergency department (ED) visits. However, best practices for ED smoking cessation counselling are still unclear.
MethodsA randomized controlled trial was conducted to determine whether an “ask, advise, and refer” approach increases 12-month, 30-day quit rates in the stable adult ED smoking population compared to usual care. Patients in the intervention group were referred to a community counselling service that offers a quitline, a text-based program, and a Web-based program. Longitudinal intention-to-treat analyses were performed.
ResultsFrom November 2011 to March 2013, 1,295 patients were enrolled from one academic tertiary care ED. Six hundred thirty-five were allocated to usual care, and 660 were allocated to intervention. Follow-up data were available for 70% of all patients at 12 months. There was no statistically significant difference in 12-month, 30-day quit rates between the two groups. However, there was a trend towards higher 7-day quit attempts, 7-day quit rates, and 30-day quit rates at 3, 6, and 12 months in the intervention group.
ConclusionIn this study, there was a trend towards increased smoking cessation following referral to a community counselling service. There was no statistically significant difference. However, if ED smoking cessation efforts were to provide even a small positive effect, such an intervention may have a significant public health impact given the extensive reach of emergency physicians.
Contributors
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- By Jeremy Atack, Alain Bresson, José Luís Cardoso, Ann M. Carlos, Oscar Gelderblom, Karl Gunnar Persson, C. Knick Harley, Morten Jerven, Willem M. Jongman, Joost Jonker, Étienne de la Vaissière, Michael Jursa, Frank D. Lewis, Larry Neal, Patrick Karl O’Brien, Şevket Pamuk, Luciano Pezzolo, Tirthankar Roy, Richard Salvucci, Jeffrey G. Williamson, R. B. Wong
- Edited by Larry Neal, University of Illinois, Urbana-Champaign, Jeffrey G. Williamson, Harvard University, Massachusetts
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- The Cambridge History of Capitalism
- Published online:
- 05 March 2014
- Print publication:
- 23 January 2014, pp xi-xii
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- By Robert S. Anderson, (Mary) Colleen Bhalla, Michelle Blanda, Christopher Carpenter, Chris Chauhan, Paul L. DeSandre, Maura Dickinson, Jonathan A. Edlow, Dany Elsayegh, Kara Iskyan Geren, Peter J. Gruber, Jin H. Han, Marianne Haughey, Teresita M. Hogan, Ula Hwang, Lindsay Jin, Michael P. Jones, Joseph H. Kahn, Keli M. Kwok, Denise Law, Megan M. Leo, Stephen Y. Liang, Judith A. Linden, Brendan G. Magauran Jr, Joseph P. Martinez, Amal Mattu, Karen M. May, Aileen McCabe, Kerry K. McCabe, Jolion McGreevy, Ron Medzon, Ravi K. Murthy, Aneesh T. Narang, Lauren M. Nentwich, David E. Newman-Toker, Jonathan S. Olshaker, Joseph R. Pare, Thomas Perera, Joanna Piechniczek-Buczek, Jesse M. Pines, Timothy Platts-Mills, Suzanne Michelle Rhodes, Lynne Rosenberg, Mark Rosenberg, Todd C. Rothenhaus, Kristine Samson, Arthur B. Sanders, Jeffrey I. Schneider, Rishi Sikka, Kirk A. Stiffler, Morsal R. Tahouni, Mary E. Tanski, Abel Wakai, Scott T. Wilber, Deborah R. Wong
- Edited by Joseph H. Kahn, Brendan G. Magauran, Jr, Jonathan S. Olshaker
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- Book:
- Geriatric Emergency Medicine
- Published online:
- 05 January 2014
- Print publication:
- 16 January 2014, pp vii-x
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- By Syed S. Ali, Nathan Allen, John E. Arbo, Elizabeth Arrington, Ani Aydin, Kenneth R. L. Bernard, Amy Caggiula, Nolan Caldwell, Jennifer L. Carey, Jennifer Carnell, Jayaram Chelluri, Michael N. Cocchi, Cristal Cristia, Vishal Demla, Bram Dolcourt, Andrew Eyre, Shawn Fagan, Brandy Ferguson, Sarah Fisher, Jonathan Friedstat, Brian C. Geyer, Brandon Godbout, Jeremy Gonda, Jeremy Goverman, Ashley L. Greiner, Casey Grover, Carla Haack, Abigail Hankin, John W. Hardin, Katrina L. Harper, Gregory Hayward, Stephen Hendriksen, Daniel Herbert-Cohen, Nadine Himelfarb, Calvin E. Hwang, Jacob D. Isserman, Joshua Jauregui, Joshua W. Joseph, Elena Kapilevich, Feras H. Khan, Sarvotham Kini, Karen A. Kinnaman, Ruth Lamm, Calvin Lee, Jarone Lee, Charles Lei, John Lemos, Daniel J. Lepp, Elisabeth Lessenich, Brandon Maughan, Julie Mayglothling, Kevin McConnell, Laura Medford-Davis, Kamal Medlej, Heather Meissen, Payal Modi, Joel Moll, Jolene H. Nakao, Matthew Nicholls, Lindsay Oelze, Carolyn Maher Overman, Viral Patel, Timothy C. Peck, Jeffrey Pepin, Candace Pettigrew, Byron Pitts, Zubaid Rafique, Chanu Rhee, Jonathan C. Roberts, Daniel Rolston, Steven C. Rougas, Benjamin Schnapp, Kathryn A. Seal, Raghu Seethala, Todd A. Seigel, Navdeep Sekhon, Kaushal Shah, Robert L. Sherwin, Kirill Shishlov, Ashley Shreves, Sebastian Siadecki, Jeffrey N. Siegelman, Liza Gonen Smith, Ted Stettner, Marie Carmelle Tabuteau, Joseph E. Tonna, N. Seth Trueger, Chad Van Ginkel, Bina Vasantharam, Graham Walker, Susan Wilcox, Sandra J. Williams, Matthew L. Wong, Nelson Wong, Samantha Wood, John Woodruff, Benjamin Zabar
- Edited by Kaushal Shah, Jarone Lee, Kamal Medlej, American University of Beirut, Scott D. Weingart
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- Book:
- Practical Emergency Resuscitation and Critical Care
- Published online:
- 05 November 2013
- Print publication:
- 24 October 2013, pp xi-xx
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- By Luis G. Acevedo, Schahram Akbarian, Ioanna Andreou, Krishnarao Appasani, Raghu K. Appasani, Julia Arand, David M. Ashley, Alexander R. Ball, Yehudit Bergman, Marina Bibikova, Angela Bithell, Francesca Bonafè, Eric E. Bouhassira, Victoria L. Boyd, Noel J. Buckley, Lars Olov Bygren, Claudio M. Caldarera, Gemma Carvill, James W. F. Catto, Sarah Derks, Ewa Dudziec, Jeffrey D. Falk, Jian-Bing Fan, Joseph M. Fernandez, David E. Fisher, Emanuela Fiumana, Tamara B. Franklin, Fei Gao, Arkadiusz Gertych, Emanuele Giordano, David Goldman, Markus Grammel, Carlo Guarnieri, Kevin L. Gunderson, Victoria (Fatemeh) G. Haghighi, Xu Han, Yong-Mahn Han, Howard C. Hang, Aditi Hazra, Laura B.K. Herzing, Norbert Hochstein, Robin Holliday, Dorothee Honsel, Mary A. Jelinek, Guanyu Ji, Yan Jiang, Atsushi Kaneda, Richard A. Katz, Hyemin Kim, Richard Kroon, Tapas K. Kundu, Benoit Labonté, Daeyoup Lee, Konstantin Lepikhov, Andrea Linnemann-Florl, Dirk Loeffert, Dylan Maixner, Isabelle M. Mansuy, Andreas Missel, D. V. Mohankrishna, Joana Carvalho Moreira de Mello, Paolo G. Morselli, Rituparna Mukhopadhyay, Claudio Muscari, Takashi Nagano, Frank Narz, Shuji Ogino, Carlo M. Oranges, Shari Orlanski, Alice Pasini, Ralf Peist, Lygia V. Pereira, Andrey Poleshko, Claire Rougeulle, Thea Rütjes, Ana Sanz, Benjamin G. Schroeder, Gerald Schock, Kornel Schuebel, B. Ruthrotha Selvi, Hogyu Seo, Natalia Shalginskikh, Andrew Sharp, Jun S. Song, Lennart Suckau, Azim Surani, Jian Tajbakhsh, Gustavo Turecki, Céline Vallot, Manon van Engeland, Jörn Walter, Nicholas C. Wong, Mark Wossidlo, Honglong Wu, Yurong Xin, Zhixiang Yan, Yu-Ying Yang, Mingzhi Ye, Kyoko Yokomori, Sephorah Zaman, Weihua Zeng, Gerald Zon
- Edited by Krishnarao Appasani
- Foreword by Azim Surani, University of Cambridge
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- Book:
- Epigenomics
- Published online:
- 05 August 2012
- Print publication:
- 02 August 2012, pp x-xxiv
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- By Rose Teteki Abbey, K. C. Abraham, David Tuesday Adamo, LeRoy H. Aden, Efrain Agosto, Victor Aguilan, Gillian T. W. Ahlgren, Charanjit Kaur AjitSingh, Dorothy B E A Akoto, Giuseppe Alberigo, Daniel E. Albrecht, Ruth Albrecht, Daniel O. Aleshire, Urs Altermatt, Anand Amaladass, Michael Amaladoss, James N. Amanze, Lesley G. Anderson, Thomas C. Anderson, Victor Anderson, Hope S. Antone, María Pilar Aquino, Paula Arai, Victorio Araya Guillén, S. Wesley Ariarajah, Ellen T. Armour, Brett Gregory Armstrong, Atsuhiro Asano, Naim Stifan Ateek, Mahmoud Ayoub, John Alembillah Azumah, Mercedes L. García Bachmann, Irena Backus, J. Wayne Baker, Mieke Bal, Lewis V. Baldwin, William Barbieri, António Barbosa da Silva, David Basinger, Bolaji Olukemi Bateye, Oswald Bayer, Daniel H. Bays, Rosalie Beck, Nancy Elizabeth Bedford, Guy-Thomas Bedouelle, Chorbishop Seely Beggiani, Wolfgang Behringer, Christopher M. Bellitto, Byard Bennett, Harold V. Bennett, Teresa Berger, Miguel A. Bernad, Henley Bernard, Alan E. Bernstein, Jon L. Berquist, Johannes Beutler, Ana María Bidegain, Matthew P. Binkewicz, Jennifer Bird, Joseph Blenkinsopp, Dmytro Bondarenko, Paulo Bonfatti, Riet en Pim Bons-Storm, Jessica A. Boon, Marcus J. Borg, Mark Bosco, Peter C. Bouteneff, François Bovon, William D. Bowman, Paul S. Boyer, David Brakke, Richard E. Brantley, Marcus Braybrooke, Ian Breward, Ênio José da Costa Brito, Jewel Spears Brooker, Johannes Brosseder, Nicholas Canfield Read Brown, Robert F. Brown, Pamela K. Brubaker, Walter Brueggemann, Bishop Colin O. Buchanan, Stanley M. Burgess, Amy Nelson Burnett, J. Patout Burns, David B. Burrell, David Buttrick, James P. Byrd, Lavinia Byrne, Gerado Caetano, Marcos Caldas, Alkiviadis Calivas, William J. Callahan, Salvatore Calomino, Euan K. Cameron, William S. Campbell, Marcelo Ayres Camurça, Daniel F. Caner, Paul E. Capetz, Carlos F. Cardoza-Orlandi, Patrick W. Carey, Barbara Carvill, Hal Cauthron, Subhadra Mitra Channa, Mark D. Chapman, James H. Charlesworth, Kenneth R. Chase, Chen Zemin, Luciano Chianeque, Philip Chia Phin Yin, Francisca H. Chimhanda, Daniel Chiquete, John T. Chirban, Soobin Choi, Robert Choquette, Mita Choudhury, Gerald Christianson, John Chryssavgis, Sejong Chun, Esther Chung-Kim, Charles M. A. Clark, Elizabeth A. Clark, Sathianathan Clarke, Fred Cloud, John B. Cobb, W. Owen Cole, John A Coleman, John J. Collins, Sylvia Collins-Mayo, Paul K. Conkin, Beth A. Conklin, Sean Connolly, Demetrios J. Constantelos, Michael A. Conway, Paula M. Cooey, Austin Cooper, Michael L. Cooper-White, Pamela Cooper-White, L. William Countryman, Sérgio Coutinho, Pamela Couture, Shannon Craigo-Snell, James L. Crenshaw, David Crowner, Humberto Horacio Cucchetti, Lawrence S. Cunningham, Elizabeth Mason Currier, Emmanuel Cutrone, Mary L. Daniel, David D. Daniels, Robert Darden, Rolf Darge, Isaiah Dau, Jeffry C. Davis, Jane Dawson, Valentin Dedji, John W. de Gruchy, Paul DeHart, Wendy J. Deichmann Edwards, Miguel A. De La Torre, George E. Demacopoulos, Thomas de Mayo, Leah DeVun, Beatriz de Vasconcellos Dias, Dennis C. Dickerson, John M. Dillon, Luis Miguel Donatello, Igor Dorfmann-Lazarev, Susanna Drake, Jonathan A. Draper, N. Dreher Martin, Otto Dreydoppel, Angelyn Dries, A. J. Droge, Francis X. D'Sa, Marilyn Dunn, Nicole Wilkinson Duran, Rifaat Ebied, Mark J. Edwards, William H. Edwards, Leonard H. Ehrlich, Nancy L. Eiesland, Martin Elbel, J. Harold Ellens, Stephen Ellingson, Marvin M. Ellison, Robert Ellsberg, Jean Bethke Elshtain, Eldon Jay Epp, Peter C. Erb, Tassilo Erhardt, Maria Erling, Noel Leo Erskine, Gillian R. Evans, Virginia Fabella, Michael A. Fahey, Edward Farley, Margaret A. Farley, Wendy Farley, Robert Fastiggi, Seena Fazel, Duncan S. Ferguson, Helwar Figueroa, Paul Corby Finney, Kyriaki Karidoyanes FitzGerald, Thomas E. FitzGerald, John R. Fitzmier, Marie Therese Flanagan, Sabina Flanagan, Claude Flipo, Ronald B. Flowers, Carole Fontaine, David Ford, Mary Ford, Stephanie A. Ford, Jim Forest, William Franke, Robert M. Franklin, Ruth Franzén, Edward H. Friedman, Samuel Frouisou, Lorelei F. Fuchs, Jojo M. Fung, Inger Furseth, Richard R. Gaillardetz, Brandon Gallaher, China Galland, Mark Galli, Ismael García, Tharscisse Gatwa, Jean-Marie Gaudeul, Luis María Gavilanes del Castillo, Pavel L. Gavrilyuk, Volney P. Gay, Metropolitan Athanasios Geevargis, Kondothra M. George, Mary Gerhart, Simon Gikandi, Maurice Gilbert, Michael J. Gillgannon, Verónica Giménez Beliveau, Terryl Givens, Beth Glazier-McDonald, Philip Gleason, Menghun Goh, Brian Golding, Bishop Hilario M. Gomez, Michelle A. Gonzalez, Donald K. Gorrell, Roy Gottfried, Tamara Grdzelidze, Joel B. Green, Niels Henrik Gregersen, Cristina Grenholm, Herbert Griffiths, Eric W. Gritsch, Erich S. Gruen, Christoffer H. Grundmann, Paul H. Gundani, Jon P. Gunnemann, Petre Guran, Vidar L. Haanes, Jeremiah M. Hackett, Getatchew Haile, Douglas John Hall, Nicholas Hammond, Daphne Hampson, Jehu J. Hanciles, Barry Hankins, Jennifer Haraguchi, Stanley S. Harakas, Anthony John Harding, Conrad L. Harkins, J. William Harmless, Marjory Harper, Amir Harrak, Joel F. Harrington, Mark W. Harris, Susan Ashbrook Harvey, Van A. Harvey, R. Chris Hassel, Jione Havea, Daniel Hawk, Diana L. Hayes, Leslie Hayes, Priscilla Hayner, S. Mark Heim, Simo Heininen, Richard P. Heitzenrater, Eila Helander, David Hempton, Scott H. Hendrix, Jan-Olav Henriksen, Gina Hens-Piazza, Carter Heyward, Nicholas J. Higham, David Hilliard, Norman A. Hjelm, Peter C. Hodgson, Arthur Holder, M. Jan Holton, Dwight N. Hopkins, Ronnie Po-chia Hsia, Po-Ho Huang, James Hudnut-Beumler, Jennifer S. Hughes, Leonard M. Hummel, Mary E. Hunt, Laennec Hurbon, Mark Hutchinson, Susan E. Hylen, Mary Beth Ingham, H. Larry Ingle, Dale T. Irvin, Jon Isaak, Paul John Isaak, Ada María Isasi-Díaz, Hans Raun Iversen, Margaret C. Jacob, Arthur James, Maria Jansdotter-Samuelsson, David Jasper, Werner G. Jeanrond, Renée Jeffery, David Lyle Jeffrey, Theodore W. Jennings, David H. Jensen, Robin Margaret Jensen, David Jobling, Dale A. Johnson, Elizabeth A. Johnson, Maxwell E. Johnson, Sarah Johnson, Mark D. Johnston, F. Stanley Jones, James William Jones, John R. Jones, Alissa Jones Nelson, Inge Jonsson, Jan Joosten, Elizabeth Judd, Mulambya Peggy Kabonde, Robert Kaggwa, Sylvester Kahakwa, Isaac Kalimi, Ogbu U. Kalu, Eunice Kamaara, Wayne C. Kannaday, Musimbi Kanyoro, Veli-Matti Kärkkäinen, Frank Kaufmann, Léon Nguapitshi Kayongo, Richard Kearney, Alice A. Keefe, Ralph Keen, Catherine Keller, Anthony J. Kelly, Karen Kennelly, Kathi Lynn Kern, Fergus Kerr, Edward Kessler, George Kilcourse, Heup Young Kim, Kim Sung-Hae, Kim Yong-Bock, Kim Yung Suk, Richard King, Thomas M. King, Robert M. Kingdon, Ross Kinsler, Hans G. Kippenberg, Cheryl A. Kirk-Duggan, Clifton Kirkpatrick, Leonid Kishkovsky, Nadieszda Kizenko, Jeffrey Klaiber, Hans-Josef Klauck, Sidney Knight, Samuel Kobia, Robert Kolb, Karla Ann Koll, Heikki Kotila, Donald Kraybill, Philip D. W. Krey, Yves Krumenacker, Jeffrey Kah-Jin Kuan, Simanga R. Kumalo, Peter Kuzmic, Simon Shui-Man Kwan, Kwok Pui-lan, André LaCocque, Stephen E. Lahey, John Tsz Pang Lai, Emiel Lamberts, Armando Lampe, Craig Lampe, Beverly J. Lanzetta, Eve LaPlante, Lizette Larson-Miller, Ariel Bybee Laughton, Leonard Lawlor, Bentley Layton, Robin A. Leaver, Karen Lebacqz, Archie Chi Chung Lee, Marilyn J. Legge, Hervé LeGrand, D. L. LeMahieu, Raymond Lemieux, Bill J. Leonard, Ellen M. Leonard, Outi Leppä, Jean Lesaulnier, Nantawan Boonprasat Lewis, Henrietta Leyser, Alexei Lidov, Bernard Lightman, Paul Chang-Ha Lim, Carter Lindberg, Mark R. Lindsay, James R. Linville, James C. Livingston, Ann Loades, David Loades, Jean-Claude Loba-Mkole, Lo Lung Kwong, Wati Longchar, Eleazar López, David W. Lotz, Andrew Louth, Robin W. Lovin, William Luis, Frank D. Macchia, Diarmaid N. J. MacCulloch, Kirk R. MacGregor, Marjory A. MacLean, Donald MacLeod, Tomas S. Maddela, Inge Mager, Laurenti Magesa, David G. Maillu, Fortunato Mallimaci, Philip Mamalakis, Kä Mana, Ukachukwu Chris Manus, Herbert Robinson Marbury, Reuel Norman Marigza, Jacqueline Mariña, Antti Marjanen, Luiz C. L. Marques, Madipoane Masenya (ngwan'a Mphahlele), Caleb J. D. Maskell, Steve Mason, Thomas Massaro, Fernando Matamoros Ponce, András Máté-Tóth, Odair Pedroso Mateus, Dinis Matsolo, Fumitaka Matsuoka, John D'Arcy May, Yelena Mazour-Matusevich, Theodore Mbazumutima, John S. McClure, Christian McConnell, Lee Martin McDonald, Gary B. McGee, Thomas McGowan, Alister E. McGrath, Richard J. McGregor, John A. McGuckin, Maud Burnett McInerney, Elsie Anne McKee, Mary B. McKinley, James F. McMillan, Ernan McMullin, Kathleen E. McVey, M. 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Nicholson, George W. E. Nickelsburg, Tatyana Nikolskaya, Damayanthi M. A. Niles, Bertil Nilsson, Nyambura Njoroge, Fidelis Nkomazana, Mary Beth Norton, Christian Nottmeier, Sonene Nyawo, Anthère Nzabatsinda, Edward T. Oakes, Gerald O'Collins, Daniel O'Connell, David W. Odell-Scott, Mercy Amba Oduyoye, Kathleen O'Grady, Oyeronke Olajubu, Thomas O'Loughlin, Dennis T. Olson, J. Steven O'Malley, Cephas N. Omenyo, Muriel Orevillo-Montenegro, César Augusto Ornellas Ramos, Agbonkhianmeghe E. Orobator, Kenan B. Osborne, Carolyn Osiek, Javier Otaola Montagne, Douglas F. Ottati, Anna May Say Pa, Irina Paert, Jerry G. Pankhurst, Aristotle Papanikolaou, Samuele F. Pardini, Stefano Parenti, Peter Paris, Sung Bae Park, Cristián G. Parker, Raquel Pastor, Joseph Pathrapankal, Daniel Patte, W. Brown Patterson, Clive Pearson, Keith F. Pecklers, Nancy Cardoso Pereira, David Horace Perkins, Pheme Perkins, Edward N. Peters, Rebecca Todd Peters, Bishop Yeznik Petrossian, Raymond Pfister, Peter C. 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Yee, Viktor Yelensky, Yeo Khiok-Khng, Gustav K. K. Yeung, Angela Yiu, Amos Yong, Yong Ting Jin, You Bin, Youhanna Nessim Youssef, Eliana Yunes, Robert Michael Zaller, Valarie H. Ziegler, Barbara Brown Zikmund, Joyce Ann Zimmerman, Aurora Zlotnik, Zhuo Xinping
- Edited by Daniel Patte, Vanderbilt University, Tennessee
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- Book:
- The Cambridge Dictionary of Christianity
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- 05 August 2012
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- 20 September 2010, pp xi-xliv
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Evaluation of Copper Penetration in Low-κ Polymer Dielectrics by Bias-Temperature Stress
- Alvin L. S. Loke, S. Simon Wong, Niranjan A. Talwalkar, Jeffrey T. Wetzel, Paul H. Townsend, Tsuneaki Tanabe, Raymond N. Vrtis, Melvin P. Zussman, Devendra Kumar
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- Journal:
- MRS Online Proceedings Library Archive / Volume 565 / 1999
- Published online by Cambridge University Press:
- 10 February 2011, 173
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- 1999
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The industry is strongly interested in integrating low-κ dielectrics with Damascene copper. Otherwise, with conventional materials, interconnects cannot continue to scale without limiting circuit performance. Integration of copper wiring with silicon dioxide (oxide) requires barrier encapsulation since copper drifts readily in oxide. An important aspect of integrating copper wiring with low-κ dielectrics is the drift behavior of copper ions in these dielectrics, which will directly impact the barrier requirements and hence integration complexity.
This work evaluates and compares the copper drift properties in six low-κ organic polymer dielectrics: parylene-F; benzocyclobutene; fluorinated polyimide; an aromatic hydrocarbon; and two varieties of poly(arylene ether). Copper/oxide/polymer/oxide/silicon capacitors are subjected to bias-temperature stress to accelerate penetration of copper from the gate electrode into the polymer. The oxide-sandwiched dielectric stack is used to overcome interface instabilities occurring when a low-κ dielectric is in direct contact with either the gate metal or silicon substrate. The copper drift rates in the various polymers are estimated by electrical techniques, including capacitance-voltage, current-voltage, and current-time measurements. Results correlate well with timeto-breakdown obtained by stressing the capacitor dielectrics. Our study shows that copper ions drift readily into fluorinated polyimide and poly(arylene ether), more slowly into parylene-F, and even more slowly into benzocyclobutene. A qualitative comparison of the chemical structures of the polymers suggests that copper drift in these polymers may possibly be retarded by increased crosslinking and enhanced by polarity in the polymer.
Evaluation of Copper Penetration in Low-κ Polymer Dielectrics by Bias-Temperature Stress
- Alvin L. S. Loke, S. Simon Wong, Niranjan A. Talwalkar, Jeffrey T. Wetzel, Paul H. Townsend, Tsuneaki Tanabe, Raymond N. Vrtis, Melvin P. Zussman, Devendra Kumar
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- Journal:
- MRS Online Proceedings Library Archive / Volume 564 / 1999
- Published online by Cambridge University Press:
- 10 February 2011, 535
- Print publication:
- 1999
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The industry is strongly interested in integrating low–κ dielectrics with Damascene copper. Otherwise, with conventional materials, interconnects cannot continue to scale without limiting circuit performance. Integration of copper wiring with silicon dioxide (oxide) requires barrier encapsulation since copper drifts readily in oxide. An important aspect of integrating copper wiring with low-K dielectrics is the drift behavior of copper ions in these dielectrics, which will directly impact the barrier requirements and hence integration complexity.
This work evaluates and compares the copper drift properties in six low-κ organic polymer dielectrics: parylene-F; benzocyclobutene; fluorinated polyimide; an aromatic hydrocarbon; and two varieties of poly(arylene ether). Copper/oxide/polymer/oxide/silicon capacitors are subjected to bias-temperature stress to accelerate penetration of copper from the gate electrode into the polymer. The oxide-sandwiched dielectric stack is used to overcome interface instabilities occurring when a low-κ dielectric is in direct contact with either the gate metal or silicon substrate. The copper drift rates in the various polymers are estimated by electrical techniques, including capacitance- voltage, current-voltage, and current-time measurements. Results correlate well with timeto- breakdown obtained by stressing the capacitor dielectrics. Our study shows that copper ions drift readily into fluorinated polyimide and poly(arylene ether), more slowly into parylene-F, and even more slowly into benzocyclobutene. A qualitative comparison of the chemical structures of the polymers suggests that copper drift in these polymers may possibly be retarded by increased crosslinking and enhanced by polarity in the polymer.
Electrical Reliability of Cu and Low-K Dielectric Integration
- S. Simon Wong, Alvin L. S. Loke, Jeffrey T. Wetzel, Paul H. Townsend, Raymond N. Vrtis, Melvin P. Zussman
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- Journal:
- MRS Online Proceedings Library Archive / Volume 511 / 1998
- Published online by Cambridge University Press:
- 10 February 2011, 317
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- 1998
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The recent demonstrations of manufacturable multilevel Cu metallization have heightened interest to integrate Cu and low-K dielectrics for future integrated circuits. For reliable integration of both materials, Cu may need to be encapsulated by barrier materials since Cu ions (Cu+) might drift through low-K dielectrics to degrade interconnect and device integrity. This paper addresses the use of electrical testing techniques to evaluate the Cu+ drift behavior of low-K polymer dielectrics. Specifically, bias-temperature stress and capacitance-voltage measurements are employed as their high sensitivities are well-suited for examining charge instabilities in dielectrics. Charge instabilities other than Cu+ drift also exist. For example, when low-K polymers come into direct contact with either a metal or Si, interface-related instabilities attributed to electron/hole injection are observed. To overcome these issues, a planar Cu/oxide/polymer/oxide/Si capacitor test structure is developed for Cu+ drift evaluation. Our study shows that Cu+ ions drift readily into poly(arylene ether) and fluorinated polyimide, but much more slowly into benzocyclobutene. A thin nitride cap layer can prevent the penetration.
Electrical Extraction of The in-Plane Dielectric Constant of Fluorinated Polyimide
- Alvin L.S. Loke, Jeffrey T. Wetzel, John J. Stankus, S. Simon Wong
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- Journal:
- MRS Online Proceedings Library Archive / Volume 476 / 1997
- Published online by Cambridge University Press:
- 15 February 2011, 129
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- 1997
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Fluorinated polyimide can potentially replace TEOS as an interlevel dielectric in future ULSI interconnect technologies because its lower dielectric constant offers reduced crosstalk, signal propagation delay, and dynamic power dissipation. One issue associated with polyimides is the anisotropy in dielectric constant, where the smaller out-of-plane dielectric constant, typically measured using parallel-plate capacitors, can misleadingly exaggerate the advantage in reducing crosstalk. In this paper, we present a novel electrical technique to estimate the in-plane dielectric constant of DuPont FPI-136M fluorinated polyimide without requiring dielectric gapfill.
A blanket FPI-136M film is deposited over interdigitated inlaid Al(0.5%Cu) structures and the crosstalk capacitance is measured. Identical inlaid structures with air and TEOS passivations are also measured for capacitance calibration. Differences in measured capacitances reflect electric fields fringing in the various passivation dielectrics above the inlaid metal. With the known dielectric constants of air and TEOS, the effective dielectric constant of FPI-136M is interpolated to be 2.8. Interconnect simulations confirm that the effective dielectric constant extraction technique is valid and accurate provided that the passivation layer is sufficiently thick to contain the fringing fields.
To estimate the in-plane dielectric constant, we use simulations to determine the combination of in-plane and out-of-plane dielectric constants that is equivalent to the extracted effective dielectric constant. With an out-of-plane dielectric constant of 2.6, the in-plane dielectric constant of FPI-136M is estimated to be 3.0. This technique is applicable to other dieletrics.
Numerical Modeling of Radiative Properties of Patterned Wafers with Sub-Micron Features
- Jeffrey B. Hoppert, Ioannis N. Miaoulis, Peter Y. Wong
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- Journal:
- MRS Online Proceedings Library Archive / Volume 429 / 1996
- Published online by Cambridge University Press:
- 10 February 2011, 51
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- 1996
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Decreasing feature sizes in the microelectronics industry have led to numerous processing problems with thin film semiconductors. Non-uniform temperature distributions, due to microscale radiation effects on the radiative properties of the thin film structures, are responsible for wafer defects. These microscale radiation effects become significant as pattern spacing and film thicknesses reach the same order of magnitude as the wavelengths of the heat-source radiation. A numerical model has been developed in which normal emissivities for patterned wafers are calculated, using an effective index of refraction technique. In this study various patterns at temperatures critical to the thermal processing are examined.
Modification of Proteases for Peptide Synthesis
- Jeffrey A. Bibbs, Ziyang Zhong, Chi-Huey Wong
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- Journal:
- MRS Online Proceedings Library Archive / Volume 174 / 1989
- Published online by Cambridge University Press:
- 21 February 2011, 223
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- 1989
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Polypeptides with well defined structures have the potential for the development for novel materials [1]. Synthesis of polypeptides suffer from racemization and protection-deprotection problems and has been dependent on the anhydride method using phosgene. There is definitely a need for a milder, stereoselective, and racemization-free procedure and it appears that enzyme-catalyzed synthesis can provide most of these features. Although proteases have been used in peptide synthesis with the above mentioned advantages, these enzymes have their own inherent catalytic properties which are disadvantageous, that is, they tend to cdeave peptide bonds. Two strategies presented here have been developed to overcome these problems.