45 results
Physiological and biochemical processes underlying the differential sucrose yield and biomass production in sugarcane varieties
- Tamires Da Silva Martins, José R. Magalhães Filho, Larissa Prado Cruz, Daniela F. S. P. Machado, Norma M. Erismann, Rose M. A. Gondim-Tomaz, Paulo E. R. Marchiori, André L. B. O. Silva, Eduardo Caruso Machado, Rafael Vasconcelos Ribeiro
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- Journal:
- Experimental Agriculture / Volume 60 / 2024
- Published online by Cambridge University Press:
- 14 May 2024, e13
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Sucrose yield in sugarcane is a complex process regulated by both environmental and endogenous factors. However, the metabolic balance driving vegetative growth and sucrose accumulation remains poorly understood. Herein, we carried out a comprehensive assessment of carbohydrate dynamics throughout the crop cycle in two sugarcane varieties varying in biomass production, evaluating the carbon metabolism in both leaves and stalks. Our data revealed that the decline in photosynthetic rates during sugarcane maturation is associated not only to accumulation of sugars in leaves but also due to stomatal and non-stomatal limitations. We found that metabolic processes in leaves and stalks were intrinsically linked. While IACSP94-2094 had higher stalk sucrose concentration than IACSP95-5000, this latter produced more biomass. Compared to IACSP95-5000, IACSP94-2094 showed higher sucrose phosphate synthase (SPS) activity in leaves and stalks, along with lower soluble acid invertase (SAI) activity in leaves during the maximum growth stage. Interestingly, IACSP94-2094 also exhibited higher stalk SPS activity and lower stalk SAI activity than IACSP95-5000 during maturation. High biomass production by IACSP95-5000 was associated with higher sucrose synthase (SuSy) and SAI activity in leaves and higher SuSy and soluble neutral invertase (SNI) activity in stalks when compared to IACSP94-2094 during the maximum growth. Despite the contrasting strategies, both varieties displayed similar total sucrose yield, a balance between sucrose concentration and biomass production. This phenomenon implies the presence of a compensatory mechanism in sugarcane, with high biomass production compensating low sucrose accumulation and vice versa.
Comparison of two electronic hand hygiene systems using real-time feedback via wireless technology to improve hand hygiene compliance in an intensive care unit
- José R. Generoso, Jr, Eduardo Casaroto, Ary Serpa Neto, Marcelo Prado, Guilherme M. Gagliardi, Fernando Gatti de Menezes, Priscila Gonçalves, Fábio Barlem Hohmann, Guilherme Benfatti Olivato, Gustavo Potratz Gonçalves, Andréa Marques Pereira, Nathalia Xavier, Marcelo Fernandes Miguel, Elivane da Silva Victor, Michael B. Edmond, Alexandre R. Marra
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- Journal:
- Antimicrobial Stewardship & Healthcare Epidemiology / Volume 2 / Issue 1 / 2022
- Published online by Cambridge University Press:
- 25 July 2022, e127
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Background:
Most hand hygiene (HH) intervention studies use a quasi-experimental design, are primarily uncontrolled before-and-after studies, or are controlled before-and-after studies with a nonequivalent control group. Well-funded studies with improved designs and HH interventions are needed.
Objectives:To evaluate healthcare worker (HCW) HH compliance with alcohol-based hand rub (ABHR) through direct observation (human observer), 2 electronic technologies, a radio frequency identification (RFID) badge system, and an invasive device sensor.
Methods:In our controlled experimental study, 2,269 observations were made over a 6-month period from July 1 to December 30, 2020, in a 4-bed intensive care unit. We compared HH compliance between a basic feedback loop system with RFID badges and an enhanced feedback loop system that utilized sensors on invasive devices.
Results:Real-time feedback by wireless technology connected to a patient’s invasive device (enhanced feedback loop) resulted in a significant increase in HH compliance (69.5% in the enhanced group vs 59.1% in the basic group; P = .0001).
Conclusion:An enhanced feedback loop system connected to invasive devices, providing real-time alerts to HCWs, is effective in improving HH compliance.
An immunoproteomics approach to identify Leishmania infantum proteins to be applied for the diagnosis of visceral leishmaniasis and human immunodeficiency virus co-infection
- Amanda S. Machado, Fernanda F. Ramos, João A. Oliveira-da-Silva, Thaís T. O. Santos, Grasiele S. V. Tavares, Lourena E. Costa, Daniela P. Lage, André Teixeira-Ferreira, Jonas Perales, Ana Paula Fernandes, Ricardo L. F. Moreira, Mariana C. Duarte, Unaí Tupinambás, Rachel B. Caligiorne, Gláucia F. Cota, Eduardo A. F. Coelho, Fernanda Ludolf
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- Journal:
- Parasitology / Volume 147 / Issue 9 / August 2020
- Published online by Cambridge University Press:
- 20 April 2020, pp. 932-939
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The co-infection between visceral leishmaniasis (VL) and human immunodeficiency virus (HIV) has increased in several countries in the world. The current serological tests are not suitable since they present low sensitivity to detect the most of VL/HIV cases, and a more precise diagnosis should be performed. In this context, in the present study, an immunoproteomics approach was performed using Leishmania infantum antigenic extracts and VL, HIV and VL/HIV patients sera, besides healthy subjects samples; aiming to identify antigenic markers for these clinical conditions. Results showed that 43 spots were recognized by antibodies in VL and VL/HIV sera, and 26 proteins were identified by mass spectrometry. Between them, β-tubulin was expressed, purified and tested in ELISA experiments as a proof of concept for validation of our immunoproteomics findings and results showed high sensitivity and specificity values to detect VL and VL/HIV patients. In conclusion, the identified proteins in the present work could be considered as candidates for future studies aiming to improvement of the diagnosis of VL and VL/HIV co-infection.
Contributors
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- By Krista Adamek, Ana Luisa K. Albernaz, J. Marcio Ayres†, Andrew J. Baker, Karen L. Bales, Adrian A. Barnett, Christopher Barton, John M. Bates, Jennie Becker, Bruna M. Bezerra, Júlio César Bicca-Marques, Richard Bodmer, Jean P. Boubli, Mark Bowler, Sarah A. Boyle, Christini Barbosa Caselli, Janice Chism, Elena P. Cunningham, José Maria C. da Silva, Lesa C. Davies, Nayara de Alcântara Cardoso, Manuella A. de Souza, Stella de la Torre, Ana Gabriela de Luna, Thomas R. Defler, Anthony Di Fiore, Eduardo Fernandez-Duque, Stephen F. Ferrari, Wilsea M.B. Figueiredo-Ready, Tracy Frampton, Paul A. Garber, Brian W. Grafton, L. Tremaine Gregory, Maria L. Harada, Amy Harrison-Levine, Walter C. Hartwig, Stefanie Heiduck, Eckhard W. Heymann, André Hirsch, Leandro Jerusalinsky, Gareth Jones, Richard F. Kay, Martin M. Kowalewski, Shawn M. Lehman, Laura Marsh, Jesús Martinez, William A. Mason, Hope Matthews, Wynlyn McBride, Shona McCann-Wood, W. Scott McGraw, D. Jeffrey Meldrum, Sally P. Mendoza, Nohelia Mercado, Russell A. Mittermeier, Mirjam N. Nadjafzadeh, Marilyn A. Norconk, Robert Gary Norman, Marcela Oliveira, Marcelo M. Oliveira, Maria Juliana Ospina Rodríguez, Erwin Palacios, Suzanne Palminteri, Liliam P. Pinto, Marcio Port-Carvalho, Leila Porter, Carlos Portillo-Quintero, George Powell, Ghillean T. Prance, Rodrigo C. Printes, Pablo Puertas, P. Kirsten Pullen, Helder L. Queiroz, Luis Reginaldo R. Rodrigues, Adriana Rodríguez, Alfred L. Rosenberger, Anthony B. Rylands, Ricardo R. Santos, Horacio Schneider, Eleonore Z.F. Setz, Suleima S.B. Silva, José S. Silva Júnior, Andrew T. Smith, Marcelo C. Sousa, Antonio S. Souto, Wilson R. Spironello, Masanaru Takai, Marcelo F. Tejedor, Cynthia L. Thompson, Diego G. Tirira, Raul Tupayachi, Bernardo Urbani, Liza M. Veiga, Marianela Velilla, João Valsecchi, Jean-Christophe Vié, Tatiana M. Vieira, Suzanne E. Walker-Pacheco, Rob Wallace, Patricia C. Wright, Charles E. Zartman
- Edited by Liza M. Veiga, Universidade Federal do Pará, Brazil, Adrian A. Barnett, Roehampton University, London, Stephen F. Ferrari, Universidade Federal de Sergipe, Brazil, Marilyn A. Norconk, Kent State University, Ohio
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- Book:
- Evolutionary Biology and Conservation of Titis, Sakis and Uacaris
- Published online:
- 05 April 2013
- Print publication:
- 11 April 2013, pp xii-xv
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What Darwin did not see: Pleistocene fossil assemblages on a high-energy coast at Ponta das Bicudas, Santiago, Cape Verde Islands
- B. GUDVEIG BAARLI, ANA G. SANTOS, EDUARDO J. MAYORAL, JORGE LEDESMA-VÁZQUEZ, MARKES E. JOHNSON, CARLOS M. DA SILVA, MÁRIO CACHÃO
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- Journal:
- Geological Magazine / Volume 150 / Issue 1 / January 2013
- Published online by Cambridge University Press:
- 28 September 2012, pp. 183-189
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Two distinct Pleistocene assemblages from SE Santiago Island are comparable to modern analogues elsewhere in the Cape Verde Islands. A low-diversity Siderastrea radians assemblage lived atop basalt knobs surrounded by sand on a slope below a cliff. A Millepora alcicornis–Megabalanus azoricus assemblage occupied the cliff. The latter was a typical rocky-shore assemblage from a high-energy setting below the tidal zone. Bioerosion structures in basalt produced by Circolites kotoncensis and Gastrochaenolites isp. also occur there. Despite extensive studies on local limestone deposits in 1832 and 1836, lack of exposure prevented Darwin from seeing these fossils.
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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. Douglas Meeks, Monica Jyotsna Melanchthon, Ilie Melniciuc-Puica, Everett Mendoza, Raymond A. Mentzer, William W. Menzies, Ina Merdjanova, Franziska Metzger, Constant J. Mews, Marvin Meyer, Carol Meyers, Vasile Mihoc, Gunner Bjerg Mikkelsen, Maria Inêz de Castro Millen, Clyde Lee Miller, Bonnie J. Miller-McLemore, Alexander Mirkovic, Paul Misner, Nozomu Miyahira, R. W. L. Moberly, Gerald Moede, Aloo Osotsi Mojola, Sunanda Mongia, Rebeca Montemayor, James Moore, Roger E. Moore, Craig E. Morrison O.Carm, Jeffry H. Morrison, Keith Morrison, Wilson J. Moses, Tefetso Henry Mothibe, Mokgethi Motlhabi, Fulata Moyo, Henry Mugabe, Jesse Ndwiga Kanyua Mugambi, Peggy Mulambya-Kabonde, Robert Bruce Mullin, Pamela Mullins Reaves, Saskia Murk Jansen, Heleen L. Murre-Van den Berg, Augustine Musopole, Isaac M. T. Mwase, Philomena Mwaura, Cecilia Nahnfeldt, Anne Nasimiyu Wasike, Carmiña Navia Velasco, Thulani Ndlazi, Alexander Negrov, James B. Nelson, David G. Newcombe, Carol Newsom, Helen J. 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. Phan, Isabel Apawo Phiri, William S. F. Pickering, Derrick G. Pitard, William Elvis Plata, Zlatko Plese, John Plummer, James Newton Poling, Ronald Popivchak, Andrew Porter, Ute Possekel, James M. Powell, Enos Das Pradhan, Devadasan Premnath, Jaime Adrían Prieto Valladares, Anne Primavesi, Randall Prior, María Alicia Puente Lutteroth, Eduardo Guzmão Quadros, Albert Rabil, Laurent William Ramambason, Apolonio M. Ranche, Vololona Randriamanantena Andriamitandrina, Lawrence R. Rast, Paul L. Redditt, Adele Reinhartz, Rolf Rendtorff, Pål Repstad, James N. Rhodes, John K. Riches, Joerg Rieger, Sharon H. Ringe, Sandra Rios, Tyler Roberts, David M. Robinson, James M. Robinson, Joanne Maguire Robinson, Richard A. H. Robinson, Roy R. Robson, Jack B. Rogers, Maria Roginska, Sidney Rooy, Rev. Garnett Roper, Maria José Fontelas Rosado-Nunes, Andrew C. Ross, Stefan Rossbach, François Rossier, John D. Roth, John K. Roth, Phillip Rothwell, Richard E. Rubenstein, Rosemary Radford Ruether, Markku Ruotsila, John E. Rybolt, Risto Saarinen, John Saillant, Juan Sanchez, Wagner Lopes Sanchez, Hugo N. Santos, Gerhard Sauter, Gloria L. Schaab, Sandra M. Schneiders, Quentin J. Schultze, Fernando F. Segovia, Turid Karlsen Seim, Carsten Selch Jensen, Alan P. F. Sell, Frank C. Senn, Kent Davis Sensenig, Damían Setton, Bal Krishna Sharma, Carolyn J. Sharp, Thomas Sheehan, N. Gerald Shenk, Christian Sheppard, Charles Sherlock, Tabona Shoko, Walter B. Shurden, Marguerite Shuster, B. Mark Sietsema, Batara Sihombing, Neil Silberman, Clodomiro Siller, Samuel Silva-Gotay, Heikki Silvet, John K. Simmons, Hagith Sivan, James C. Skedros, Abraham Smith, Ashley A. Smith, Ted A. Smith, Daud Soesilo, Pia Søltoft, Choan-Seng (C. S.) Song, Kathryn Spink, Bryan Spinks, Eric O. Springsted, Nicolas Standaert, Brian Stanley, Glen H. Stassen, Karel Steenbrink, Stephen J. Stein, Andrea Sterk, Gregory E. Sterling, Columba Stewart, Jacques Stewart, Robert B. Stewart, Cynthia Stokes Brown, Ken Stone, Anne Stott, Elizabeth Stuart, Monya Stubbs, Marjorie Hewitt Suchocki, David Kwang-sun Suh, Scott W. Sunquist, Keith Suter, Douglas Sweeney, Charles H. Talbert, Shawqi N. Talia, Elsa Tamez, Joseph B. Tamney, Jonathan Y. Tan, Yak-Hwee Tan, Kathryn Tanner, Feiya Tao, Elizabeth S. Tapia, Aquiline Tarimo, Claire Taylor, Mark Lewis Taylor, Bishop Abba Samuel Wolde Tekestebirhan, Eugene TeSelle, M. Thomas Thangaraj, David R. Thomas, Andrew Thornley, Scott Thumma, Marcelo Timotheo da Costa, George E. “Tink” Tinker, Ola Tjørhom, Karen Jo Torjesen, Iain R. Torrance, Fernando Torres-Londoño, Archbishop Demetrios [Trakatellis], Marit Trelstad, Christine Trevett, Phyllis Trible, Johannes Tromp, Paul Turner, Robert G. Tuttle, Archbishop Desmond Tutu, Peter Tyler, Anders Tyrberg, Justin Ukpong, Javier Ulloa, Camillus Umoh, Kristi Upson-Saia, Martina Urban, Monica Uribe, Elochukwu Eugene Uzukwu, Richard Vaggione, Gabriel Vahanian, Paul Valliere, T. J. Van Bavel, Steven Vanderputten, Peter Van der Veer, Huub Van de Sandt, Louis Van Tongeren, Luke A. Veronis, Noel Villalba, Ramón Vinke, Tim Vivian, David Voas, Elena Volkova, Katharina von Kellenbach, Elina Vuola, Timothy Wadkins, Elaine M. Wainwright, Randi Jones Walker, Dewey D. Wallace, Jerry Walls, Michael J. Walsh, Philip Walters, Janet Walton, Jonathan L. Walton, Wang Xiaochao, Patricia A. Ward, David Harrington Watt, Herold D. Weiss, Laurence L. Welborn, Sharon D. Welch, Timothy Wengert, Traci C. West, Merold Westphal, David Wetherell, Barbara Wheeler, Carolinne White, Jean-Paul Wiest, Frans Wijsen, Terry L. Wilder, Felix Wilfred, Rebecca Wilkin, Daniel H. Williams, D. Newell Williams, Michael A. Williams, Vincent L. Wimbush, Gabriele Winkler, Anders Winroth, Lauri Emílio Wirth, James A. Wiseman, Ebba Witt-Brattström, Teofil Wojciechowski, John Wolffe, Kenman L. Wong, Wong Wai Ching, Linda Woodhead, Wendy M. Wright, Rose Wu, Keith E. Yandell, Gale A. 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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- The Cambridge Dictionary of Christianity
- Published online:
- 05 August 2012
- Print publication:
- 20 September 2010, pp xi-xliv
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Contents
- Paulo S. R. Diniz, Universidade Federal do Rio de Janeiro, Eduardo A. B. da Silva, Universidade Federal do Rio de Janeiro, Sergio L. Netto, Universidade Federal do Rio de Janeiro
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- Digital Signal Processing
- Published online:
- 05 June 2012
- Print publication:
- 02 September 2010, pp vii-xv
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6 - IIR filter approximations
- Paulo S. R. Diniz, Universidade Federal do Rio de Janeiro, Eduardo A. B. da Silva, Universidade Federal do Rio de Janeiro, Sergio L. Netto, Universidade Federal do Rio de Janeiro
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- Digital Signal Processing
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- 05 June 2012
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- 02 September 2010, pp 349-408
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Summary
Introduction
This chapter deals with the design methods in which a desired frequency response is approximated by a transfer function consisting of a ratio of polynomials. In general, this type of transfer function yields an impulse response of infinite duration. Therefore, the systems approximated in this chapter are commonly referred to as IIR filters.
In general, IIR filters are able to approximate a prescribed frequency response with fewer multiplications than FIR filters. For that matter, IIR filters can be more suitable for some practical applications, especially those involving real-time signal processing.
In Section 6.2 we study the classical methods of analog filter approximation, namely the Butterworth, Chebyshev, and elliptic approximations. These methods are the most widely used for approximations meeting prescribed magnitude specifications. They originated in the continuous-time domain and their use in the discrete-time domain requires an appropriate transformation.
We then address, in Section 6.3, two approaches that transform a continuous-time transfer function into a discrete-time transfer function, namely the impulse-invariance and bilinear transformation methods.
Section 6.4 deals with frequency transformation methods in the discrete-time domain. These methods allow the mapping of a given filter type to another; for example, the transformation of a given lowpass filter into a desired bandpass filter.
In applications where magnitude and phase specifications are imposed, we can approximate the desired magnitude specifications by one of the classical transfer functions and design a phase equalizer to meet the phase specifications.
8 - Multirate systems
- Paulo S. R. Diniz, Universidade Federal do Rio de Janeiro, Eduardo A. B. da Silva, Universidade Federal do Rio de Janeiro, Sergio L. Netto, Universidade Federal do Rio de Janeiro
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Summary
Introduction
In many applications of digital signal processing, it is necessary for different sampling rates to coexist within a given system. One common example is when two subsystems working at different sampling rates have to communicate and the sampling rates must be made compatible. Another case is when a wideband digital signal is decomposed into several nonoverlapping narrowband channels in order to be transmitted. In such a case, each narrowband channel may have its sampling rate decreased until its Nyquist limit is reached, thereby saving transmission bandwidth.
Here, we describe such systems which are generally referred to as multirate systems. Multirate systems are used in several applications, ranging from digital filter design to signal coding and compression, and have been increasingly present in modern digital systems.
First, we study the basic operations of decimation and interpolation, and show how arbitrary rational sampling-rate changes can be implemented with them. Then, we describe properties pertaining to the multirate systems, namely their valid inverse operations and the noble identities. With these properties introduced, the next step is to present the polyphase decompositions and the commutator models, which are key tools in multirate systems. The design of decimation and interpolation filters is also addressed. A step further is to deal with filter design techniques which use decimation and interpolation in order to achieve a prescribed set of filter specifications.
9 - Filter banks
- Paulo S. R. Diniz, Universidade Federal do Rio de Janeiro, Eduardo A. B. da Silva, Universidade Federal do Rio de Janeiro, Sergio L. Netto, Universidade Federal do Rio de Janeiro
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Summary
Introduction
In Chapter 8 we dealt with multirate systems in general; that is, systems in which more than one sampling rate coexist. Operations of decimation, interpolation, and sampling-rate changes were studied, as well as some filter design techniques using multirate concepts.
In a number of applications, it is necessary to split a digital signal into several frequency bands. After such decomposition, the signal is represented by more samples than in the original stage. However, we can attempt to decimate each band, ending up with a digital signal decomposed into several frequency bands without increasing the overall number of samples. The question is whether it is possible to recover the original signal exactly from the decimated bands. Systems which decompose and reassemble the signals are generally called filter banks.
In this chapter, we deal with filter banks, showing several ways in which a signal can be decomposed into critically decimated frequency bands, and recovered from them with minimum error. We start with an analysis of M-band filter banks, giving conditions for perfect reconstruction. Then we perform both frequency- and time-domain analyses of filter banks, followed by a discussion on orthogonality. We also treat two-band perfect reconstruction filter banks, and present the special designs for quadrature mirror filters (QMFs) and conjugate quadrature filters (CQFs). In addition, we shift to M-band filter banks, analyzing block transforms, cosine-modulated filter banks, and lapped transforms.
References
- Paulo S. R. Diniz, Universidade Federal do Rio de Janeiro, Eduardo A. B. da Silva, Universidade Federal do Rio de Janeiro, Sergio L. Netto, Universidade Federal do Rio de Janeiro
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4 - Digital filters
- Paulo S. R. Diniz, Universidade Federal do Rio de Janeiro, Eduardo A. B. da Silva, Universidade Federal do Rio de Janeiro, Sergio L. Netto, Universidade Federal do Rio de Janeiro
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7 - Spectral estimation
- Paulo S. R. Diniz, Universidade Federal do Rio de Janeiro, Eduardo A. B. da Silva, Universidade Federal do Rio de Janeiro, Sergio L. Netto, Universidade Federal do Rio de Janeiro
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Summary
Introduction
In previous chapters we were introduced to some design techniques for FIR and IIR digital filters. Some of these techniques can also be used in other applications related to the general field of digital signal processing. In the present chapter we consider the very practical problem of estimating the power spectral density (PSD) of a given discrete-time signal y(n). This problem appears in several applications, such as radar/sonar systems, music transcription, speech modeling, and so on. In general, the problem is often solved by first estimating the autocorrelation function associated with the data at hand, followed by a Fourier transform to obtain the desired spectral description of the process, as suggested by the Wiener–Khinchin theorem to be described in this chapter.
There are several algorithms for performing spectral estimation. Each one has different characteristics with respect to computational complexity, precision, frequency resolution, or other statistical aspects. We may classify all algorithms as nonparametric or parametric methods. Nonparametric methods do not assume any particular structure behind the available data, whereas parametric schemes consider that the process follows some pattern characterized by a specific set of parameters pertaining to a given model. In general, parametric approaches tend to be simpler and more accurate, but they depend on some a priori information regarding the problem at hand.
10 - Wavelet transforms
- Paulo S. R. Diniz, Universidade Federal do Rio de Janeiro, Eduardo A. B. da Silva, Universidade Federal do Rio de Janeiro, Sergio L. Netto, Universidade Federal do Rio de Janeiro
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- Digital Signal Processing
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Introduction
In Chapter 9 we dealt with filter banks, which are important in several applications. In this chapter, wavelet transforms are considered. They come from the area of functional analysis and generate great interest in the signal processing community, because of their ability to represent and analyze signals with varying time and frequency resolutions. Their digital implementation can be regarded as a special case of critically decimated filter banks. Multiresolution decompositions are then presented as an application of wavelet transforms. The concepts of regularity and number of vanishing moments of a wavelet transform are then explored. Two-dimensional wavelet transforms are introduced, with emphasis on image processing. Wavelet transforms of finite-length signals are also dealt with. We wrap up the chapter with a Do-it-yourself section followed by a brief description of functions from the Matlab Wavelet Toolbox which are useful for wavelets implementation.
Wavelet transforms
Wavelet transforms are a relatively recent development in functional analysis that have attracted a great deal of attention from the signal processing community (Daubechies, 1991). The wavelet transform of a function belonging to ℒ2{ℝ}, the space of the square integrable functions, is its decomposition in a base formed by expansions, compressions, and translations of a single mother function ψ(t), called a wavelet.
The applications of wavelet transforms range from quantum physics to signal coding. It can be shown that for digital signals the wavelet transform is a special case of critically decimated filter banks (Vetterli & Herley, 1992).
11 - Finite-precision digital signal processing
- Paulo S. R. Diniz, Universidade Federal do Rio de Janeiro, Eduardo A. B. da Silva, Universidade Federal do Rio de Janeiro, Sergio L. Netto, Universidade Federal do Rio de Janeiro
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Summary
Introduction
This chapter starts by addressing some implementation methods for digital filtering algorithms and structures. The implementation of any building block of digital signal processing can be performed using a software routine on a simple personal computer. In this case, the designer's main concern becomes the description of the desired filter as an efficient algorithm that can be easily converted into a piece of software. In such cases, the hardware concerns tend to be noncritical, except for some details such as memory size, processing speed, and data input/output.
Another implementation strategy is based on specific hardware, especially suitable for the application at hand. In such cases, the system architecture must be designed within the speed constraints at a minimal cost. This form of implementation is mainly justified in applications that require high processing speed or in large-scale production. The four main forms of appropriate hardware for implementing a given system are:
The development of a specific architecture using basic commercial electronic components and integrated circuits (Jackson et al., 1968; Peled & Liu, 1974, 1985; Freeny, 1975; Rabiner & Gold, 1975;Wanhammar, 1981).
The use of programmable logic devices (PLDs), such as field-programmable gate arrays (FPGAs), which represent an intermediate integrated stage between discrete hardware and full-custom integrated circuits or digital signal processors (DSPs) (Skahill, 1996).
The design of a dedicated integrated circuit for the application at hand using computer-automated tools for a very large scale integration (VLSI) design.
[…]
Frontmatter
- Paulo S. R. Diniz, Universidade Federal do Rio de Janeiro, Eduardo A. B. da Silva, Universidade Federal do Rio de Janeiro, Sergio L. Netto, Universidade Federal do Rio de Janeiro
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13 - Efficient IIR structures
- Paulo S. R. Diniz, Universidade Federal do Rio de Janeiro, Eduardo A. B. da Silva, Universidade Federal do Rio de Janeiro, Sergio L. Netto, Universidade Federal do Rio de Janeiro
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Summary
Introduction
The most widely used realizations for IIR filters are the cascade and parallel forms of second-order, and, sometimes, first-order, sections. The main advantages of these realizations come from their inherent modularity, which leads to efficient VLSI implementations, to simplified noise and sensitivity analyses, and to simple limit-cycle control. This chapter presents high-performance second-order structures, which are used as building blocks in high-order realizations. The concept of section ordering for the cascade form, which can reduce roundoff noise in the filter output, is introduced. Then we present a technique to reduce the output roundoff-noise effect known as error spectrum shaping. This is followed by consideration of some closed-form equations for the scaling coefficients of second-order sections for the design of parallel-form filters.
We also deal with other interesting realizations, such as the doubly complementary filters, made from allpass blocks, and IIR lattice structures, whose synthesis method is presented. Arelated class of realizations is the wave digital filters, which have very low sensitivity and also allow the elimination of zero-input and overflow limit cycles. The wave digital filters are derived from analog filter prototypes, employing the concepts of incident and reflected waves. The detailed design of these structures is presented in this chapter.
IIR parallel and cascade filters
The Nth-order direct forms seen in Chapter 4, Figures 4.11–4.13, have roundoff-noise transfer functions Gi(z) (see Figure 11.16) and scaling transfer functions Fi(z) (see Figure 11.20) whose L2 or L∞ norms assume significantly high values.
Index
- Paulo S. R. Diniz, Universidade Federal do Rio de Janeiro, Eduardo A. B. da Silva, Universidade Federal do Rio de Janeiro, Sergio L. Netto, Universidade Federal do Rio de Janeiro
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1 - Discrete-time signals and systems
- Paulo S. R. Diniz, Universidade Federal do Rio de Janeiro, Eduardo A. B. da Silva, Universidade Federal do Rio de Janeiro, Sergio L. Netto, Universidade Federal do Rio de Janeiro
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3 - Discrete transforms
- Paulo S. R. Diniz, Universidade Federal do Rio de Janeiro, Eduardo A. B. da Silva, Universidade Federal do Rio de Janeiro, Sergio L. Netto, Universidade Federal do Rio de Janeiro
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- 02 September 2010, pp 143-221
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