7 results
Mg-Smectite Authigenesis in a Marine Evaporative Environment, Salina Ometepec, Baja California
- Victoria C. Hover, Lynn M. Walter, Donald R. Peacor, Anna M. Martini
-
- Journal:
- Clays and Clay Minerals / Volume 47 / Issue 3 / June 1999
- Published online by Cambridge University Press:
- 28 February 2024, pp. 252-268
-
- Article
- Export citation
-
Formation of authigenic trioctahedral Mg-rich smectite is common in evaporative lake sediments, but was not described previously in modern marine evaporative environments. This study documents formation of authigenic K-rich, Mg-smectite during very early diagenesis in the dominantly siliciclastic Salina Ometepec (Baja California), a large supratidal evaporative sabkha complex near the mouth of the Colorado River. Here, sediment pore waters are exceptionally Mg2+-rich relative to other marine evaporative environments due to suppressed sulfate reduction which limits production of carbonate alkalinity and, hence, carbonate (particularly dolomite) precipitation. Sediment cores were obtained along a five km transect seaward across the hypersaline mud flat to evaluate how these atypical geochemical conditions would affect the clay mineral compositions.
Scanning transmission electron microscopy (STEM) observations show that the smectite from the marine Inlet, near the sediment source, consists of grains of irregular shape that give selected area diffraction (SAED) patterns reflecting dominant turbostratic stacking. Analytical electron microscopy (AEM) analyses indicate that K+ is the dominant interlayer cation; the mean composition is approximately K0.7(Al3.3Fe(III)0.3Mg0.5)(Al0.5Si7.5)O20(OH)4. Such smectite is implied to be detrital in part because it is similar to smectite known to be deposited by the Colorado River.
Smectite from the hypersaline mud flat occurs as aggregates of small subhedral pseudohexagonal plate or lath-shaped crystals ≤250 nm in diameter, with thicknesses varying between three and ten layers. The SAED patterns reflect substantial turbostratic stacking, but with a greater frequency of interlayer coherency as compared with detrital smectite. Crystals from greater sediment depths are larger and more nearly euhedral. This smectite is dominantly trioctahedral, with mean composition approximately K0.7(Al0.7Fe(III)0.5Mg4.45)(Al1.2Si6.8)O20(OH)4 (saponitic). This smectite is inferred to be dominantly authigenic in origin.
The X-ray diffraction (XRD) and STEM/AEM data collectively imply that detrital aluminous dioctahedral smectite reacts to form authigenic Mg-rich trioctahedral smectite, driven in part by the high Mg2+/ Ca2+ ratio of pore waters. Such early-formed Mg-rich smectite may be the precursor for the trioctahedral mixed-layer smectite, corrensite, and chlorite assemblages found in ancient marine evaporative sequences. These results also add to the accumulating evidence that interlayer K+ in marine smectite is fixed during the earliest stages of marine diagenesis near the sediment water interface.
Neurodevelopmental assessment of infants born to mothers with hypertensive disorder of pregnancy at six months of age
- Marisa E. Sala, M. Florencia Romero, Anabella Romero, M. Victoria Fasano, Ana M. Varea, Patricia Carrera, Martín R. Salazar, Walter G. Espeche, Horacio F. González
-
- Journal:
- Journal of Developmental Origins of Health and Disease / Volume 13 / Issue 2 / April 2022
- Published online by Cambridge University Press:
- 20 May 2021, pp. 197-203
-
- Article
- Export citation
-
Infant neurodevelopment is a complex process which may be affected by different events during pregnancy, such as hypertensive disorders of pregnancy (HDP). We conducted a prospective cohort study to compare the prevalence of neurodevelopmental disorders in infants born to mothers with and without HDP at six months of age. Participants attended the Health Observatory of Instituto de Desarrollo e Investigaciones Pediátricas “Prof. Dr. Fernando E. Viteri” during 2018 and 2019. Infant neurodevelopment was assessed with the Bayley Scales of Infant and Toddler Development—Third Edition (Bayley-III). Data were analyzed using Chi-square, Student’s t-test and Mann–Whitney test. Of the 132 participating infants, 68 and 64 were born to mothers with and without HDP, respectively. At six months, the prevalence of risk of neurodevelopmental delay was significantly higher in infants born to mothers with than without HDP (27.9% vs. 9.4%; p = 0.008) (odds ratio, 3.71; 95% confidence interval, 1.30; 12.28). In conclusion, infants born to mothers with HDP had three times increased risk of neurodevelopmental delay at six months of age.
Ataxia and Parkinsonism in Metronidazole Neurotoxicity
- Ryan T. Muir, Marck Mercado, Victoria R. Walter, Nikhita Singhal, Priscilla Kwan, Walter Kucharczyk, Nathan M. Stall, Peter L. Carlen
-
- Journal:
- Canadian Journal of Neurological Sciences / Volume 48 / Issue 2 / March 2021
- Published online by Cambridge University Press:
- 20 July 2020, pp. 273-274
-
- Article
-
- You have access Access
- HTML
- Export citation
4 - Red-cockaded woodpeckers: Alternative pathways to breeding success
- Edited by Walter D. Koenig, Cornell University, New York, Janis L. Dickinson, Cornell University, New York
-
- Book:
- Cooperative Breeding in Vertebrates
- Published online:
- 18 December 2015
- Print publication:
- 07 January 2016, pp 58-76
-
- Chapter
- Export citation
Contributors
-
- By Rony A. Adam, Gloria Bachmann, Nichole M. Barker, Randall B. Barnes, John Bennett, Inbar Ben-Shachar, Jonathan S. Berek, Sarah L. Berga, Monica W. Best, Eric J. Bieber, Frank M. Biro, Shan Biscette, Anita K. Blanchard, Candace Brown, Ronald T. Burkman, Joseph Buscema, John E. Buster, Michael Byas-Smith, Sandra Ann Carson, Judy C. Chang, Annie N. Y. Cheung, Mindy S. Christianson, Karishma Circelli, Daniel L. Clarke-Pearson, Larry J. Copeland, Bryan D. Cowan, Navneet Dhillon, Michael P. Diamond, Conception Diaz-Arrastia, Nicole M. Donnellan, Michael L. Eisenberg, Eric Eisenhauer, Sebastian Faro, J. Stuart Ferriss, Lisa C. Flowers, Susan J. Freeman, Leda Gattoc, Claudine Marie Gayle, Timothy M. Geiger, Jennifer S. Gell, Alan N. Gordon, Victoria L. Green, Jon K. Hathaway, Enrique Hernandez, S. Paige Hertweck, Randall S. Hines, Ira R. Horowitz, Fred M. Howard, William W. Hurd, Fidan Israfilbayli, Denise J. Jamieson, Carolyn R. Jaslow, Erika B. Johnston-MacAnanny, Rohna M. Kearney, Namita Khanna, Caroline C. King, Jeremy A. King, Ira J. Kodner, Tamara Kolev, Athena P. Kourtis, S. Robert Kovac, Ertug Kovanci, William H. Kutteh, Eduardo Lara-Torre, Pallavi Latthe, Herschel W. Lawson, Ronald L. Levine, Frank W. Ling, Larry I. Lipshultz, Steven D. McCarus, Robert McLellan, Shruti Malik, Suketu M. Mansuria, Mohamed K. Mehasseb, Pamela J. Murray, Saloney Nazeer, Farr R. Nezhat, Hextan Y. S. Ngan, Gina M. Northington, Peggy A. Norton, Ruth M. O'Regan, Kristiina Parviainen, Resad P. Pasic, Tanja Pejovic, K. Ulrich Petry, Nancy A. Phillips, Ashish Pradhan, Elizabeth E. Puscheck, Suneetha Rachaneni, Devon M. Ramaeker, David B. Redwine, Robert L. Reid, Carla P. Roberts, Walter Romano, Peter G. Rose, Robert L. Rosenfield, Shon P. Rowan, Mack T. Ruffin, Janice M. Rymer, Evis Sala, Ritu Salani, Joseph S. Sanfilippo, Mahmood I. Shafi, Roger P. Smith, Meredith L. Snook, Thomas E. Snyder, Mary D. Stephenson, Thomas G. Stovall, Richard L. Sweet, Philip M. Toozs-Hobson, Togas Tulandi, Elizabeth R. Unger, Denise S. Uyar, Marion S. Verp, Rahi Victory, Tamara J. Vokes, Michelle J. Washington, Katharine O'Connell White, Paul E. Wise, Frank M. Wittmaack, Miya P. Yamamoto, Christine Yu, Howard A. Zacur
- Edited by Eric J. Bieber, Joseph S. Sanfilippo, University of Pittsburgh, Ira R. Horowitz, Emory University, Atlanta, Mahmood I. Shafi
-
- Book:
- Clinical Gynecology
- Published online:
- 05 April 2015
- Print publication:
- 23 April 2015, pp viii-xiv
-
- Chapter
- Export citation
Contributors
-
- By Lenard A. Adler, Pinky Agarwal, Rehan Ahmed, Jagga Rao Alluri, Fawaz Al-Mufti, Samuel Alperin, Michael Amoashiy, Michael Andary, David J. Anschel, Padmaja Aradhya, Vandana Aspen, Esther Baldinger, Jee Bang, George D. Baquis, John J. Barry, Jason J. S. Barton, Julius Bazan, Amanda R. Bedford, Marlene Behrmann, Lourdes Bello-Espinosa, Ajay Berdia, Alan R. Berger, Mark Beyer, Don C. Bienfang, Kevin M. Biglan, Thomas M. Boes, Paul W. Brazis, Jonathan L. Brisman, Jeffrey A. Brown, Scott E. Brown, Ryan R. Byrne, Rina Caprarella, Casey A. Chamberlain, Wan-Tsu W. Chang, Grace M. Charles, Jasvinder Chawla, David Clark, Todd J. Cohen, Joe Colombo, Howard Crystal, Vladimir Dadashev, Sarita B. Dave, Jean Robert Desrouleaux, Richard L. Doty, Robert Duarte, Jeffrey S. Durmer, Christyn M. Edmundson, Eric R. Eggenberger, Steven Ender, Noam Epstein, Alberto J. Espay, Alan B. Ettinger, Niloofar (Nelly) Faghani, Amtul Farheen, Edward Firouztale, Rod Foroozan, Anne L. Foundas, David Elliot Friedman, Deborah I. Friedman, Steven J. Frucht, Oded Gerber, Tal Gilboa, Martin Gizzi, Teneille G. Gofton, Louis J. Goodrich, Malcolm H. Gottesman, Varda Gross-Tsur, Deepak Grover, David A. Gudis, John J. Halperin, Maxim D. Hammer, Andrew R. Harrison, L. Anne Hayman, Galen V. Henderson, Steven Herskovitz, Caitlin Hoffman, Laryssa A. Huryn, Andres M. Kanner, Gary P. Kaplan, Bashar Katirji, Kenneth R. Kaufman, Annie Killoran, Nina Kirz, Gad E. Klein, Danielle G. Koby, Christopher P. Kogut, W. Curt LaFrance, Patrick J.M. Lavin, Susan W. Law, James L. Levenson, Richard B. Lipton, Glenn Lopate, Daniel J. Luciano, Reema Maindiratta, Robert M. Mallery, Georgios Manousakis, Alan Mazurek, Luis J. Mejico, Dragana Micic, Ali Mokhtarzadeh, Walter J. Molofsky, Heather E. Moss, Mark L. Moster, Manpreet Multani, Siddhartha Nadkarni, George C. Newman, Rolla Nuoman, Paul A. Nyquist, Gaia Donata Oggioni, Odi Oguh, Denis Ostrovskiy, Kristina Y. Pao, Juwen Park, Anastas F. Pass, Victoria S. Pelak, Jeffrey Peterson, John Pile-Spellman, Misha L. Pless, Gregory M. Pontone, Aparna M. Prabhu, Michael T. Pulley, Philip Ragone, Prajwal Rajappa, Venkat Ramani, Sindhu Ramchandren, Ritesh A. Ramdhani, Ramses Ribot, Heidi D. Riney, Diana Rojas-Soto, Michael Ronthal, Daniel M. Rosenbaum, David B. Rosenfield, Durga Roy, Michael J. Ruckenstein, Max C. Rudansky, Eva Sahay, Friedhelm Sandbrink, Jade S. Schiffman, Angela Scicutella, Maroun T. Semaan, Robert C. Sergott, Aashit K. Shah, David M. Shaw, Amit M. Shelat, Claire A. Sheldon, Anant M. Shenoy, Yelizaveta Sher, Jessica A. Shields, Tanya Simuni, Rajpaul Singh, Eric E. Smouha, David Solomon, Mehri Songhorian, Steven A. Sparr, Egilius L. H. Spierings, Eve G. Spratt, Beth Stein, S.H. Subramony, Rosa Ana Tang, Cara Tannenbaum, Hakan Tekeli, Amanda J. Thompson, Michael J. Thorpy, Matthew J. Thurtell, Pedro J. Torrico, Ira M. Turner, Scott Uretsky, Ruth H. Walker, Deborah M. Weisbrot, Michael A. Williams, Jacques Winter, Randall J. Wright, Jay Elliot Yasen, Shicong Ye, G. Bryan Young, Huiying Yu, Ryan J. Zehnder
- Edited by Alan B. Ettinger, Albert Einstein College of Medicine, New York, Deborah M. Weisbrot, State University of New York, Stony Brook
-
- Book:
- Neurologic Differential Diagnosis
- Published online:
- 05 June 2014
- Print publication:
- 17 April 2014, pp xi-xx
-
- Chapter
- Export citation
Contributors
-
- 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
-
- Book:
- Epigenomics
- Published online:
- 05 August 2012
- Print publication:
- 02 August 2012, pp x-xxiv
-
- Chapter
- Export citation