16 results
Referral patterns for specialist child and adolescent mental health services in the Republic of Ireland during the COVID-19 pandemic compared with 2019 and 2018
- Fiona McNicholas, Ian Kelleher, Elma Hedderman, Fionnuala Lynch, Elaine Healy, Therese Thornton, Edwina Barry, Lisa Kelly, James McDonald, Keith Holmes, Glenda Kavanagh, Maria Migone
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- Journal:
- BJPsych Open / Volume 7 / Issue 3 / May 2021
- Published online by Cambridge University Press:
- 03 May 2021, e91
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Background
Countries worldwide are experiencing a third wave of the coronavirus disease 2019 (COVID-19) pandemic. Government-imposed restrictive measures continue with undetermined effects on physical and mental health.
AimsTo compare child and adolescent mental health services (CAMHS) referrals over 11 months (January–November) in 2020, 2019 and 2018 and examine any impact the different phases of the COVID-19 restrictions might have on referral rates.
MethodMonthly CAMHS Health Service Executive data were examined, covering a catchment population of 260 560 or 12.7% of all youth (age group 0–18 years) in Ireland. The total number of urgent and routine referrals, appointments offered, rates of non-attendances and discharge outcome are presented.
ResultsThere was a significant drop in referrals in 2020, compared with prior years (χ2 = 10.3, d.f. = 2, P = 0.006). Referrals in 2020 dropped from March to May by 11% and from June to August by 10.3%. From September, both routine and urgent referrals increased by 50% compared with previous years (2018/2019), with the highest increase in November 2020 (180%). Clinic activity also increased from September, with double the number of out-patient appointments offered, compared with previous years (χ2 = 5171.72, d.f. = 3, P < 0.001) and lower (6.6%) rates of non-attendance (χ2 = 868.35, d.f. = 3, P < 0.001).
ConclusionsIn 2020, following an initial decline, referrals to CAMHS increased consistently from September. Such unprecedented increase in referrals places further strain on services that are already underresourced and underfunded, with the likelihood of increased waiting lists post COVID-19. It is envisaged that once the pandemic is over, resources will be even more constrained, and CAMHS will be urgently in need of additional ring-fenced funding.
Contributors
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- By Mitchell Aboulafia, Frederick Adams, Marilyn McCord Adams, Robert M. Adams, Laird Addis, James W. Allard, David Allison, William P. Alston, Karl Ameriks, C. Anthony Anderson, David Leech Anderson, Lanier Anderson, Roger Ariew, David Armstrong, Denis G. Arnold, E. J. Ashworth, Margaret Atherton, Robin Attfield, Bruce Aune, Edward Wilson Averill, Jody Azzouni, Kent Bach, Andrew Bailey, Lynne Rudder Baker, Thomas R. Baldwin, Jon Barwise, George Bealer, William Bechtel, Lawrence C. Becker, Mark A. Bedau, Ernst Behler, José A. Benardete, Ermanno Bencivenga, Jan Berg, Michael Bergmann, Robert L. Bernasconi, Sven Bernecker, Bernard Berofsky, Rod Bertolet, Charles J. Beyer, Christian Beyer, Joseph Bien, Joseph Bien, Peg Birmingham, Ivan Boh, James Bohman, Daniel Bonevac, Laurence BonJour, William J. Bouwsma, Raymond D. Bradley, Myles Brand, Richard B. Brandt, Michael E. Bratman, Stephen E. Braude, Daniel Breazeale, Angela Breitenbach, Jason Bridges, David O. Brink, Gordon G. Brittan, Justin Broackes, Dan W. Brock, Aaron Bronfman, Jeffrey E. Brower, Bartosz Brozek, Anthony Brueckner, Jeffrey Bub, Lara Buchak, Otavio Bueno, Ann E. Bumpus, Robert W. Burch, John Burgess, Arthur W. Burks, Panayot Butchvarov, Robert E. Butts, Marina Bykova, Patrick Byrne, David Carr, Noël Carroll, Edward S. Casey, Victor Caston, Victor Caston, Albert Casullo, Robert L. Causey, Alan K. L. Chan, Ruth Chang, Deen K. Chatterjee, Andrew Chignell, Roderick M. Chisholm, Kelly J. Clark, E. J. Coffman, Robin Collins, Brian P. Copenhaver, John Corcoran, John Cottingham, Roger Crisp, Frederick J. Crosson, Antonio S. Cua, Phillip D. Cummins, Martin Curd, Adam Cureton, Andrew Cutrofello, Stephen Darwall, Paul Sheldon Davies, Wayne A. Davis, Timothy Joseph Day, Claudio de Almeida, Mario De Caro, Mario De Caro, John Deigh, C. F. Delaney, Daniel C. Dennett, Michael R. DePaul, Michael Detlefsen, Daniel Trent Devereux, Philip E. Devine, John M. Dillon, Martin C. Dillon, Robert DiSalle, Mary Domski, Alan Donagan, Paul Draper, Fred Dretske, Mircea Dumitru, Wilhelm Dupré, Gerald Dworkin, John Earman, Ellery Eells, Catherine Z. Elgin, Berent Enç, Ronald P. Endicott, Edward Erwin, John Etchemendy, C. Stephen Evans, Susan L. Feagin, Solomon Feferman, Richard Feldman, Arthur Fine, Maurice A. Finocchiaro, William FitzPatrick, Richard E. Flathman, Gvozden Flego, Richard Foley, Graeme Forbes, Rainer Forst, Malcolm R. Forster, Daniel Fouke, Patrick Francken, Samuel Freeman, Elizabeth Fricker, Miranda Fricker, Michael Friedman, Michael Fuerstein, Richard A. Fumerton, Alan Gabbey, Pieranna Garavaso, Daniel Garber, Jorge L. A. Garcia, Robert K. Garcia, Don Garrett, Philip Gasper, Gerald Gaus, Berys Gaut, Bernard Gert, Roger F. Gibson, Cody Gilmore, Carl Ginet, Alan H. Goldman, Alvin I. Goldman, Alfonso Gömez-Lobo, Lenn E. Goodman, Robert M. Gordon, Stefan Gosepath, Jorge J. E. Gracia, Daniel W. Graham, George A. Graham, Peter J. Graham, Richard E. Grandy, I. Grattan-Guinness, John Greco, Philip T. Grier, Nicholas Griffin, Nicholas Griffin, David A. Griffiths, Paul J. Griffiths, Stephen R. Grimm, Charles L. Griswold, Charles B. Guignon, Pete A. Y. Gunter, Dimitri Gutas, Gary Gutting, Paul Guyer, Kwame Gyekye, Oscar A. Haac, Raul Hakli, Raul Hakli, Michael Hallett, Edward C. Halper, Jean Hampton, R. James Hankinson, K. R. Hanley, Russell Hardin, Robert M. Harnish, William Harper, David Harrah, Kevin Hart, Ali Hasan, William Hasker, John Haugeland, Roger Hausheer, William Heald, Peter Heath, Richard Heck, John F. Heil, Vincent F. Hendricks, Stephen Hetherington, Francis Heylighen, Kathleen Marie Higgins, Risto Hilpinen, Harold T. Hodes, Joshua Hoffman, Alan Holland, Robert L. Holmes, Richard Holton, Brad W. Hooker, Terence E. Horgan, Tamara Horowitz, Paul Horwich, Vittorio Hösle, Paul Hoβfeld, Daniel Howard-Snyder, Frances Howard-Snyder, Anne Hudson, Deal W. Hudson, Carl A. Huffman, David L. Hull, Patricia Huntington, Thomas Hurka, Paul Hurley, Rosalind Hursthouse, Guillermo Hurtado, Ronald E. Hustwit, Sarah Hutton, Jonathan Jenkins Ichikawa, Harry A. Ide, David Ingram, Philip J. Ivanhoe, Alfred L. Ivry, Frank Jackson, Dale Jacquette, Joseph Jedwab, Richard Jeffrey, David Alan Johnson, Edward Johnson, Mark D. Jordan, Richard Joyce, Hwa Yol Jung, Robert Hillary Kane, Tomis Kapitan, Jacquelyn Ann K. Kegley, James A. Keller, Ralph Kennedy, Sergei Khoruzhii, Jaegwon Kim, Yersu Kim, Nathan L. King, Patricia Kitcher, Peter D. Klein, E. D. Klemke, Virginia Klenk, George L. Kline, Christian Klotz, Simo Knuuttila, Joseph J. Kockelmans, Konstantin Kolenda, Sebastian Tomasz Kołodziejczyk, Isaac Kramnick, Richard Kraut, Fred Kroon, Manfred Kuehn, Steven T. Kuhn, Henry E. Kyburg, John Lachs, Jennifer Lackey, Stephen E. Lahey, Andrea Lavazza, Thomas H. Leahey, Joo Heung Lee, Keith Lehrer, Dorothy Leland, Noah M. Lemos, Ernest LePore, Sarah-Jane Leslie, Isaac Levi, Andrew Levine, Alan E. Lewis, Daniel E. Little, Shu-hsien Liu, Shu-hsien Liu, Alan K. L. Chan, Brian Loar, Lawrence B. Lombard, John Longeway, Dominic McIver Lopes, Michael J. Loux, E. J. Lowe, Steven Luper, Eugene C. Luschei, William G. Lycan, David Lyons, David Macarthur, Danielle Macbeth, Scott MacDonald, Jacob L. Mackey, Louis H. Mackey, Penelope Mackie, Edward H. Madden, Penelope Maddy, G. B. Madison, Bernd Magnus, Pekka Mäkelä, Rudolf A. Makkreel, David Manley, William E. Mann (W.E.M.), Vladimir Marchenkov, Peter Markie, Jean-Pierre Marquis, Ausonio Marras, Mike W. Martin, A. P. Martinich, William L. McBride, David McCabe, Storrs McCall, Hugh J. McCann, Robert N. McCauley, John J. McDermott, Sarah McGrath, Ralph McInerny, Daniel J. McKaughan, Thomas McKay, Michael McKinsey, Brian P. McLaughlin, Ernan McMullin, Anthonie Meijers, Jack W. Meiland, William Jason Melanson, Alfred R. Mele, Joseph R. Mendola, Christopher Menzel, Michael J. Meyer, Christian B. Miller, David W. Miller, Peter Millican, Robert N. Minor, Phillip Mitsis, James A. Montmarquet, Michael S. Moore, Tim Moore, Benjamin Morison, Donald R. Morrison, Stephen J. Morse, Paul K. Moser, Alexander P. D. Mourelatos, Ian Mueller, James Bernard Murphy, Mark C. Murphy, Steven Nadler, Jan Narveson, Alan Nelson, Jerome Neu, Samuel Newlands, Kai Nielsen, Ilkka Niiniluoto, Carlos G. Noreña, Calvin G. Normore, David Fate Norton, Nikolaj Nottelmann, Donald Nute, David S. Oderberg, Steve Odin, Michael O’Rourke, Willard G. Oxtoby, Heinz Paetzold, George S. Pappas, Anthony J. Parel, Lydia Patton, R. P. Peerenboom, Francis Jeffry Pelletier, Adriaan T. Peperzak, Derk Pereboom, Jaroslav Peregrin, Glen Pettigrove, Philip Pettit, Edmund L. Pincoffs, Andrew Pinsent, Robert B. Pippin, Alvin Plantinga, Louis P. Pojman, Richard H. Popkin, John F. Post, Carl J. Posy, William J. Prior, Richard Purtill, Michael Quante, Philip L. Quinn, Philip L. Quinn, Elizabeth S. Radcliffe, Diana Raffman, Gerard Raulet, Stephen L. Read, Andrews Reath, Andrew Reisner, Nicholas Rescher, Henry S. Richardson, Robert C. Richardson, Thomas Ricketts, Wayne D. Riggs, Mark Roberts, Robert C. Roberts, Luke Robinson, Alexander Rosenberg, Gary Rosenkranz, Bernice Glatzer Rosenthal, Adina L. Roskies, William L. Rowe, T. M. Rudavsky, Michael Ruse, Bruce Russell, Lilly-Marlene Russow, Dan Ryder, R. M. Sainsbury, Joseph Salerno, Nathan Salmon, Wesley C. Salmon, Constantine Sandis, David H. Sanford, Marco Santambrogio, David Sapire, Ruth A. Saunders, Geoffrey Sayre-McCord, Charles Sayward, James P. Scanlan, Richard Schacht, Tamar Schapiro, Frederick F. Schmitt, Jerome B. Schneewind, Calvin O. Schrag, Alan D. Schrift, George F. Schumm, Jean-Loup Seban, David N. Sedley, Kenneth Seeskin, Krister Segerberg, Charlene Haddock Seigfried, Dennis M. Senchuk, James F. Sennett, William Lad Sessions, Stewart Shapiro, Tommie Shelby, Donald W. Sherburne, Christopher Shields, Roger A. Shiner, Sydney Shoemaker, Robert K. Shope, Kwong-loi Shun, Wilfried Sieg, A. John Simmons, Robert L. Simon, Marcus G. Singer, Georgette Sinkler, Walter Sinnott-Armstrong, Matti T. Sintonen, Lawrence Sklar, Brian Skyrms, Robert C. Sleigh, Michael Anthony Slote, Hans Sluga, Barry Smith, Michael Smith, Robin Smith, Robert Sokolowski, Robert C. Solomon, Marta Soniewicka, Philip Soper, Ernest Sosa, Nicholas Southwood, Paul Vincent Spade, T. L. S. Sprigge, Eric O. Springsted, George J. Stack, Rebecca Stangl, Jason Stanley, Florian Steinberger, Sören Stenlund, Christopher Stephens, James P. Sterba, Josef Stern, Matthias Steup, M. A. Stewart, Leopold Stubenberg, Edith Dudley Sulla, Frederick Suppe, Jere Paul Surber, David George Sussman, Sigrún Svavarsdóttir, Zeno G. Swijtink, Richard Swinburne, Charles C. Taliaferro, Robert B. Talisse, John Tasioulas, Paul Teller, Larry S. Temkin, Mark Textor, H. S. Thayer, Peter Thielke, Alan Thomas, Amie L. Thomasson, Katherine Thomson-Jones, Joshua C. Thurow, Vzalerie Tiberius, Terrence N. Tice, Paul Tidman, Mark C. Timmons, William Tolhurst, James E. Tomberlin, Rosemarie Tong, Lawrence Torcello, Kelly Trogdon, J. D. Trout, Robert E. Tully, Raimo Tuomela, John Turri, Martin M. Tweedale, Thomas Uebel, Jennifer Uleman, James Van Cleve, Harry van der Linden, Peter van Inwagen, Bryan W. Van Norden, René van Woudenberg, Donald Phillip Verene, Samantha Vice, Thomas Vinci, Donald Wayne Viney, Barbara Von Eckardt, Peter B. M. Vranas, Steven J. Wagner, William J. Wainwright, Paul E. Walker, Robert E. Wall, Craig Walton, Douglas Walton, Eric Watkins, Richard A. Watson, Michael V. Wedin, Rudolph H. Weingartner, Paul Weirich, Paul J. Weithman, Carl Wellman, Howard Wettstein, Samuel C. Wheeler, Stephen A. White, Jennifer Whiting, Edward R. Wierenga, Michael Williams, Fred Wilson, W. Kent Wilson, Kenneth P. Winkler, John F. Wippel, Jan Woleński, Allan B. Wolter, Nicholas P. Wolterstorff, Rega Wood, W. Jay Wood, Paul Woodruff, Alison Wylie, Gideon Yaffe, Takashi Yagisawa, Yutaka Yamamoto, Keith E. Yandell, Xiaomei Yang, Dean Zimmerman, Günter Zoller, Catherine Zuckert, Michael Zuckert, Jack A. Zupko (J.A.Z.)
- Edited by Robert Audi, University of Notre Dame, Indiana
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- The Cambridge Dictionary of Philosophy
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- 05 August 2015
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- 27 April 2015, pp ix-xxx
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Characterization and optimization of ion implantation for high spatial resolution quantum well intermixing in GaAs/AlGaAs superlattices
- Usman Younis, Barry M. Holmes, David C. Hutchings
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- The European Physical Journal - Applied Physics / Volume 66 / Issue 1 / April 2014
- Published online by Cambridge University Press:
- 01 April 2014, 10101
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- April 2014
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Processes to achieve high spatial resolution ion implantation induced quantum well intermixing in GaAs/AlGaAs superlattices have been developed. Ion implantation has been carried out using various doses of 4 MeV As2+ ion beam, followed by rapid thermal annealing at various temperatures for 60 s. Low temperature photoluminescence measurements reveal a blue-shift up to 90 nm in the energy band-gap. Propagation losses have been characterized in the intermixed waveguides, and losses as low as 0.55 cm−1 have been observed for 0.5 × 1013 cm−2 implantation dose which gives a blue-shift of 68 nm when annealed at 775 °C. The spatial resolution of ~1.2 μm has been observed at the depth of 2 μm inside the epitaxial structure.
e-Dairy: a dynamic and stochastic whole-farm model that predicts biophysical and economic performance of grazing dairy systems
- J. Baudracco, N. Lopez-Villalobos, C. W. Holmes, E. A. Comeron, K. A. Macdonald, T. N. Barry
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A whole-farm, stochastic and dynamic simulation model was developed to predict biophysical and economic performance of grazing dairy systems. Several whole-farm models simulate grazing dairy systems, but most of them work at a herd level. This model, named e-Dairy, differs from the few models that work at an animal level, because it allows stochastic behaviour of the genetic merit of individual cows for several traits, namely, yields of milk, fat and protein, live weight (LW) and body condition score (BCS) within a whole-farm model. This model accounts for genetic differences between cows, is sensitive to genotype × environment interactions at an animal level and allows pasture growth, milk and supplements price to behave stochastically. The model includes an energy-based animal module that predicts intake at grazing, mammary gland functioning and body lipid change. This whole-farm model simulates a 365-day period for individual cows within a herd, with cow parameters randomly generated on the basis of the mean parameter values, defined as input and variance and co-variances from experimental data sets. The main inputs of e-Dairy are farm area, use of land, type of pasture, type of crops, monthly pasture growth rate, supplements offered, nutritional quality of feeds, herd description including herd size, age structure, calving pattern, BCS and LW at calving, probabilities of pregnancy, average genetic merit and economic values for items of income and costs. The model allows to set management policies to define: dry-off cows (ceasing of lactation), target pre- and post-grazing herbage mass and feed supplementation. The main outputs are herbage dry matter intake, annual pasture utilisation, milk yield, changes in BCS and LW, economic farm profit and return on assets. The model showed satisfactory accuracy of prediction when validated against two data sets from farmlet system experiments. Relative prediction errors were <10% for all variables, and concordance correlation coefficients over 0.80 for annual pasture utilisation, yields of milk and milk solids (MS; fat plus protein), and of 0.69 and 0.48 for LW and BCS, respectively. A simulation of two contrasting dairy systems is presented to show the practical use of the model. The model can be used to explore the effects of feeding level and genetic merit and their interactions for grazing dairy systems, evaluating the trade-offs between profit and the associated risk.
Development of Surface Marker System for the Observation of Microstructural Changes in Nuclear Graphite using Micro X-ray Tomography
- Rosemary A. Holmes, Abbie N. Jones, Lorraine McDermott, Barry Marsden
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- Journal:
- MRS Online Proceedings Library Archive / Volume 1475 / 2012
- Published online by Cambridge University Press:
- 23 March 2012, imrc11-1475-nw35-o09
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- 2012
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Current energy demands and future energy needs are a growing industry which at present attracts a large amount of research and investment of which nuclear energy is an integral part. Eight new nuclear stations are proposed to be developed in the UK over the next ten years to meet this demand. In order for nuclear energy to sustain growth and development, nuclear decommissioning of first and second generation power stations needs to be addressed in the U.K. and worldwide. Presently the UK has 36 graphite moderated reactors as a result of the UK military and civil programs, which over the next twenty years will close. This will result in ∼99’000 tonnes of irradiated graphite waste for which no current national decommissioning strategy exists. The main issues associated with this waste are the large volume and activation products associated. By far the greatest inventory is from 3H and 14C. An EU Euroatom FP7 Program; CARBOWASTE was established in 2008 with the aim of developing treatment and disposal options for graphite.
This research is based within CARBOWASTE, the main objectives are to understand the mechanisms involved in the production, location and removal of radioisotopes from nuclear graphite. Computed X-ray Tomography (CT) will be used in order to quantify the initial porosity in conjunction with thermal treatment (ex situ) in order to eventually identify the location of 14C within the matrix of irradiated graphite, through the preferential chemically controlled oxidation of graphite. Unirradiated Pile Grade A graphite samples have been laser and manually marked in order align the samples prior to and post thermal treatment to determine the degree of porosity changes and weight loss under a range of thermal oxidation parameters.
e-Cow: an animal model that predicts herbage intake, milk yield and live weight change in dairy cows grazing temperate pastures, with and without supplementary feeding
- J. Baudracco, N. Lopez-Villalobos, C. W. Holmes, E. A. Comeron, K. A. Macdonald, T. N. Barry, N. C. Friggens
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This animal simulation model, named e-Cow, represents a single dairy cow at grazing. The model integrates algorithms from three previously published models: a model that predicts herbage dry matter (DM) intake by grazing dairy cows, a mammary gland model that predicts potential milk yield and a body lipid model that predicts genetically driven live weight (LW) and body condition score (BCS). Both nutritional and genetic drives are accounted for in the prediction of energy intake and its partitioning. The main inputs are herbage allowance (HA; kg DM offered/cow per day), metabolisable energy and NDF concentrations in herbage and supplements, supplements offered (kg DM/cow per day), type of pasture (ryegrass or lucerne), days in milk, days pregnant, lactation number, BCS and LW at calving, breed or strain of cow and genetic merit, that is, potential yields of milk, fat and protein. Separate equations are used to predict herbage intake, depending on the cutting heights at which HA is expressed. The e-Cow model is written in Visual Basic programming language within Microsoft Excel®. The model predicts whole-lactation performance of dairy cows on a daily basis, and the main outputs are the daily and annual DM intake, milk yield and changes in BCS and LW. In the e-Cow model, neither herbage DM intake nor milk yield or LW change are needed as inputs; instead, they are predicted by the e-Cow model. The e-Cow model was validated against experimental data for Holstein–Friesian cows with both North American (NA) and New Zealand (NZ) genetics grazing ryegrass-based pastures, with or without supplementary feeding and for three complete lactations, divided into weekly periods. The model was able to predict animal performance with satisfactory accuracy, with concordance correlation coefficients of 0.81, 0.76 and 0.62 for herbage DM intake, milk yield and LW change, respectively. Simulations performed with the model showed that it is sensitive to genotype by feeding environment interactions. The e-Cow model tended to overestimate the milk yield of NA genotype cows at low milk yields, while it underestimated the milk yield of NZ genotype cows at high milk yields. The approach used to define the potential milk yield of the cow and equations used to predict herbage DM intake make the model applicable for predictions in countries with temperate pastures.
Quasi-Phase Matching Magneto-Optical Waveguides
- David C. Hutchings, Barry M. Holmes
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- Journal:
- MRS Online Proceedings Library Archive / Volume 1291 / 2011
- Published online by Cambridge University Press:
- 22 March 2011, mrsf10-1291-j03-04
- Print publication:
- 2011
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Photonic integration has proved remarkably successful in combining multiple optical devices onto a single chip with the benefits of added functionality, and reduction in costs, arising from the replacement of manual assembly and alignment of individual components with lithographic techniques. However, the incorporation of optical isolators and related non-reciprocal devices within standard optoelectronic wafer platforms is exceptionally challenging. Preferred magneto-optic materials cannot be exploited as waveguide core layers on semiconductor wafers due to a lower refractive index. Another difficulty is the phase velocity mismatch as a consequence of the inherent structural birefringence associated with waveguide geometries.
Our approach to the integration of an optical isolator with a III-V semiconductor laser involves combining a nonreciprocal mode converter with a reciprocal mode converter, based on an asymmetric profiled rib waveguide, fabricated by Reactive Ion Etching. We demonstrate that suitably tapered waveguides can be employed to connect the mode converter to other sections thereby avoiding problems caused by mode-matching and reflections from the section interfaces.
The nonreciprocal mode converter is formed from a continuation of the III-V semiconductor waveguide core with a magneto-optic upper cladding so that Faraday rotation occurs through the interaction of the evanescent tail. The phase velocity mismatch due to the waveguide birefringence is overcome using a quasi-phase-matching approach. Lithography is used to pattern the top cladding so that the film immediately on top of the waveguide core alternates between magnetooptic and a non-magneto-optic dielectric of a similar refractive index. Our first demonstrations used a dielectric (silica or silicon nitride) patterned by etching, or lift-off, on top of a GaAs rib waveguide, over which was deposited a magneto-optic film. This film was deposited by sputtering from a Ce:YIG target and demonstrated magnetic hysteresis, but, as it was not annealed, it was believed to consist of Ce:YIG and/or gamma iron oxide microcrystallites embedded in an amorphous matrix. With quasi-phase-matching periods of 110–160 μm and a waveguide length of 8 mm, we were able to demonstrate up to 12% non-reciprocal TE- to TM-mode conversion around a wavelength of 1.3 μm using the remanent magnetisation.
In order to enhance the magneto-optic effect it is desirable to anneal such films. However the mismatch in thermal expansion coefficients results in a catastrophic failure of samples with large area film coverage. This problem has been shown to be alleviated by patterning the YIG film. Unfortunately wet-etching of YIG also etches (Al)GaAs and, therefore, the development of a lift-off process for YIG deposition has been undertaken. Initial results are promising with ∼100 μm×2.5 μm YIG sections deposited on a GaAs layer which remain intact after an anneal in an oxygen atmosphere.
Effects of cold conditions on heat production by young sambar (Cervus unicolor) and red deer (Cervus elaphus)
- G. Semiadi, C. W. Holmes, T. N. Barry, P. D. Muir
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- Journal:
- The Journal of Agricultural Science / Volume 126 / Issue 2 / March 1996
- Published online by Cambridge University Press:
- 27 March 2009, pp. 221-226
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An experiment to measure the effects of cold conditions upon heat production in young sambar (Cervus unicolor) and red deer (Cervus elaphus) was conducted during winter 1994, at Massey University, Palmerston North, New Zealand (NZ), using four young animals of each species. Animals were fed a pelleted concentrated diet (total N 29g/kg DM; 11·9MJ metabolizable energy (ME)/kg DM) at approximately maintenance ME intake (MEI). Hair coat characteristics were measured on samples cut from a patch on the mid-side of the body. Pairs of animals (one sambar and one red deer) were confined in two open circuit calorimetry chambers (one deer in each chamber) for 18-day periods, and oxygen consumption was measured at 20 and 5 °C, with and without simulated wind (6 km/h). Heat production was calculated as 20·5 MJ/1 oxygen consumed.
Hair coats of sambar deer were less deep, lighter in weight (g/m2) and contained a lower proportion of undercoat than those of red deer. Fibre length of both guard hairs and undercoat were shorter in sambar deer than in red deer, whilst fibre diameter of both guard hairs and undercoat was greater in sambar deer. Heat production (HP) at 20 °C was lower in sambar than in red deer (P <0·05; 0·46 v. 0·48-0·53 MJ/kgW0·75 per day). Increases in HP from 20 to 5 °C and from 20 °C to 5 °C W (i.e. with wind effect) were greater in sambar than in red deer (P < 0·01; 34 v. 16% and 44 v. 20%, respectively). Calculated lower critical temperatures (LCT) were higher for sambar than for red deer (P < 0·10) both in the absence (0 km/h; 11·6 v. 8·9 °C) and in the presence of wind (6 km/h; 140 v. 11·1 °C). Under field conditions, young sambar deer are likely to require more shelter and better feeding during cold weather than do red deer.
Growth responses in red deer calves and hinds grazing red clover, chicory or perennial ryegrass/white clover swards during lactation
- J. H. Niezen, T. N. Barry, J. Hodgson, P. R. Wilson, A. M. Ataja, W. J. Parker, C. W. Holmes
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- Journal:
- The Journal of Agricultural Science / Volume 121 / Issue 2 / October 1993
- Published online by Cambridge University Press:
- 27 March 2009, pp. 255-263
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Two experiments were conducted at the Massey University Deer Unit, New Zealand in 1990 and 1991 to evaluate the performance of lactating red deer hinds and their calves grazing conventional perennial ryegrass-based pastures, red clover or chicory. In both experiments, hind and calf performance was evaluated from 1 month post-parturition over a 2½ month summer period to weaning at 3½ months of age.
In Expt 1, hinds and calves were grazed on low (5·4 kg dry matter (DM)/hd/day), medium (10·8) or high (16·4) allowances of red clover, or on a medium allowance of a conventional ryegrass/white clover sward (9·9 DM/hd/day). In Expt 2, hinds and calves grazed equal DM allowances (12 kg DM/hd/day) of perennial ryegrass/white clover, chicory or red clover.
Red clover generally had higher organic matter digestibility (OMD) and higher total N than ryegrass/white clover, and when grazed at equal DM allowances, promoted higher voluntary food intake in the hinds, increased calf growth (430 v. 330 g/day) and increased hind liveweight change. Although decreasing the red clover allowance in Expt 1 slightly but non-significantly decreased hind voluntary food intake and decreased both calf and hind liveweight change, all low red clover values were still consistently higher than all ryegrass/white clover values (P < 0·05). In Expt 2, chicory was of higher OMD and ash content than red clover but N content was lower and similar to ryegrass/white clover. Chicory promoted lower levels of calf liveweight change than red clover but higher than ryegrass/white clover. Hind liveweight change on chicory was lower than on red clover and was similar to ryegrass/white clover. It was concluded that red clover offers potential as a special purpose forage for deer production and that further experimental work is needed with chicory.
Crystallization of yttrium-iron garnet (YIG) in thin films: Nucleation and growth aspects
- Michael V. Zaezjev, Manda Chandra Sekhar, Marcello Ferrera, Luca Razzari, Barry M Holmes, Marc Sorel, David C Hutchings, Alain Pignolet, Roberto Morandotti
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- Journal:
- MRS Online Proceedings Library Archive / Volume 1036 / 2007
- Published online by Cambridge University Press:
- 01 February 2011, 1036-M04-19
- Print publication:
- 2007
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We have studied the crystallization of the yttrium - iron garnet (Y3Fe5O12, YIG) polycrystalline phase in thin films fabricated by means of pulsed laser deposition . Films were deposited on MgO substrates in vacuum, in argon, and in oxygen. A subsequent post-deposition heat treatment (annealing) was done at 800°C in air. We have shown that the crystallization of YIG was precluded by co-existent parasitic phases present in the as-deposited films. Specifically, the growth of the parasitic phase needs to be suppressed in order to get a single-phase polycrystalline YIG. Lowering the substrate temperature has been shown to be a simple and efficient way to suppress the growth of parasitic phase and to obtain good quality YIG films after thermal treatment. This procedure has been demonstrated to be successful even when the YIG films were grown in vacuum and their composition was significantly out of stoichiometry.
Experiments Towards the Realisation of a Monolithically-Integrated Optical Isolator Incorporating Quasi-Phase Matched Magneto-Optical Effects
- Barry. M. Holmes, David. C. Hutchings, Josef. J. Bregenzer
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- Journal:
- MRS Online Proceedings Library Archive / Volume 834 / 2004
- Published online by Cambridge University Press:
- 01 February 2011, J4.4
- Print publication:
- 2004
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Experiments towards the realisation of the necessary components for future integrated waveguide optical isolators have been conducted. The design, fabrication and characterisation of GaAs/AlGaAs reciprocal mode converters, realised through the use of three novel approaches, is reported. These devices have been tested at λ=0.9m and 1.3m, producing TE-TM conversion efficiencies up to 70%. Initial investigations into the inclusion of magneto optic materials with III-V semiconductor structures for non-reciprocal mode conversion are also discussed.
Methane emission by alpaca and sheep fed on lucerne hay or grazed on pastures of perennial ryegrass/white clover or birdsfoot trefoil
- C. S. PINARES-PATIÑO, M. J. ULYATT, G. C. WAGHORN, K. R. LASSEY, T. N. BARRY, C. W. HOLMES, D. E. JOHNSON
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- Journal:
- The Journal of Agricultural Science / Volume 140 / Issue 2 / March 2003
- Published online by Cambridge University Press:
- 20 May 2003, pp. 215-226
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Based on the knowledge that alpaca (Lama pacos) have a lower fractional outflow rate of feed particles (particulate FOR) from their forestomach than sheep (San Martin 1987), the current study measured methane (CH4) production and other digestion parameters in these species in three successive experiments (1, 2 and 3): Experiment 1, lucerne hay fed indoors; Experiment 2, grazed on perennial ryegrass/white clover pasture (PRG/WC); and Experiment 3, grazed on birdsfoot trefoil (Lotus corniculatus) pasture (Lotus). Six male alpaca and six castrated Romney sheep were simultaneously and successively fed on the forages either ad libitum or at generous herbage allowances (grazing). CH4 production (g/day) (using the sulphur hexafluoride tracer technique), voluntary feed intake (VFI), diet quality, and protozoa counts and volatile fatty acid concentrations in samples of forestomach contents were determined. In addition, feed digestibility, energy and nitrogen (N) balances and microbial N supply from the forestomach (using purine derivatives excretion) were measured in Experiment 1.
Diets selected by alpaca were of lower quality than those selected by sheep, and the voluntary gross energy intakes (GEI, MJ) per kg of liveweight0·75 were consistently lower (P<0·001) for the alpaca than for the sheep (0·74 v. 1·36, 0·61 v. 1·32 and 0·77 v. 2·53 on lucerne hay, PRG/WC and Lotus, respectively). Alpaca and sheep did not differ (P>0·05) in their CH4 yields (% GEI) when fed on lucerne hay (5·1 v. 4·7), but alpaca had a higher CH4 yield when fed on PRG/WC (9·4 v. 7·5, P<0·05) and Lotus (6·4 v. 2·7, P<0·001). When grazing on Lotus, the sheep had very high protozoa counts in their forestomach contents, compared with those with the other forages and those in the alpaca. On lucerne hay and Lotus, but not on PRG/WC, the alpaca had higher (P<0·01) acetate/propionate ratio in their forestomach fluid than sheep. When fed on lucerne hay, alpaca and sheep did not differ (P>0·05) in diet N partition or microbial N yield, but alpaca had higher (P<0·05) neutral detergent fibre digestibility (0·478 v. 0·461) and lower (P<0·01) urinary energy losses (5·2 v. 5·8 % GEI) than sheep. It is suggested that differences between these species in forestomach particulate FOR might have been the underlying physiological mechanism responsible for the differences in CH4 yield, although the between-species differences in VFI and diet quality also had a major effect on it.
Persistence of differences between sheep in methane emission under generous grazing conditions
- C. S. PINARES-PATIÑO, M. J. ULYATT, K. R. LASSEY, T. N. BARRY, C. W. HOLMES
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- Journal:
- The Journal of Agricultural Science / Volume 140 / Issue 2 / March 2003
- Published online by Cambridge University Press:
- 20 May 2003, pp. 227-233
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Four low and four high methane (CH4) emitters were selected from a flock of 20 Romney sheep on the basis of CH4 production rates per unit of intake, measured at grazing using the sulphur hexafluoride (SF6) tracer technique. Methane emissions from these sheep were monitored at grazing for four periods (P): October, November, January and February 1999/2000. All measurements were carried out on perennial ryegrass/white clover pasture under generous herbage allowance, and the sheep were maintained on similar pastures during non-measurement periods. The tracer technique was used for all the CH4 measurements and feed DM intake was calculated from total faecal collection and estimated DM digestibility. Data for liveweight (LW), gross energy intake (GEI) and CH4 emission were analysed using split-plot analysis of variance. In addition, a between-period rank order correlation analysis was carried out for CH4 emission data.
Low CH4 emitters were heavier (P<0·05) than the high emitters in all the periods, but they did not differ (P<0·05) in their gross energy intakes (GEI: MJ/kg LW0·75). Low and high CH4 emitters consistently maintained their initial rankings in CH4 yield (% GEI) throughout the subsequent periods and the correlation analysis of rank order for CH4 yield showed strong between-period correlation coefficients, although this was weaker in the last period. It is suggested that feeding conditions that maximize feed intake (e.g. generous allowance of good quality pasture under grazing) favour the expression and persistence of between-sheep differences in CH4 yield.
Rumen function and digestion parameters associated with differences between sheep in methane emissions when fed chaffed lucerne hay
- C. S. PINARES-PATIÑO, M. J. ULYATT, K. R. LASSEY, T. N. BARRY, C. W. HOLMES
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- Journal:
- The Journal of Agricultural Science / Volume 140 / Issue 2 / March 2003
- Published online by Cambridge University Press:
- 20 May 2003, pp. 205-214
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An indoor experiment involving 10 rumen-cannulated Romney sheep was conducted in May and June 1998 at AgResearch Grasslands, Palmerston North, New Zealand, under restricted feeding conditions, in order to test the hypothesis that animal factors, in particular rumen fractional outflow rate (FOR) and rumen volume, have an influence on the between-sheep variation in methane (CH4) emission. Sheep were fed 2-hourly on chaffed lucerne hay. Following an acclimatization period of 21 days, the experiment lasted 16 days. Energy and nitrogen (N) balances were measured on days 1–6. Cr-EDTA marker was continuously infused into the rumen from day 9 to 16, and rumen contents emptied and sampled on days 13 and 16. Particulate and fluid FOR were estimated using feed lignin and Cr-EDTA, respectively. Daily CH4 production was measured by the sulphur hexafluoride tracer technique on days 2, 5, 6, 12 and 15 of the experiment.
CH4 production (g/day) was positively correlated with the pool size of organic matter (OM) in the rumen (OM pool, g) (r=0·84, P=0·002), OM intake (OMI, g/day) (r=0·67, P=0·04), and the rumen fill (g, wet digesta) (r=0·76, P=0·01). Multiple regression analysis showed that CH4 production was best predicted (R2=0·88) as a function of OM pool and the molar % of butyrate; however, OM pool alone accounted for a large proportion (R2=0·71) of the variation in CH4 production.
CH4 yield (% gross energy intake, % GEI) was negatively correlated with the particulate FOR (%/h) (r=−0·75, P=0·01) and buffering capacity of rumen fluid (mmol HCl) (r=−0·72, P=0·02), but positively correlated with the digestibility of cellulose (r=0·66, P=0·04). Multiple regression analysis showed that CH4 yield was best predicted as a function of particulate FOR, OMI (g/kg liveweight0·75) and the molar % of butyrate (R2=0·88). Particulate FOR alone explained a large proportion (R2=0·57) of the variation in CH4 yield. Particulate FOR was negatively correlated with rumen fill (r=−0·69, P=0·03) and digestibility of cellulose (r=−0·65, P=0·04).
These results suggest that sheep with lower rumen particulate FOR (i.e. longer rumen retention times) had larger rumen fills and higher fibre digestibilities and CH4 yields. If rumen particulate FOR is to be used as a tool for CH4 mitigation, the repeatability of its relationship to CH4 emission must be assessed, preferably under grazing conditions.
The efficiency of utilization of energy and nitrogen in young sambar (Cervus unicolor) and red deer (Cervus elaphus)
- G. SEMIADI, C. W. HOLMES, T. N. BARRY, P. D. MUIR
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- The Journal of Agricultural Science / Volume 130 / Issue 2 / March 1998
- Published online by Cambridge University Press:
- 01 March 1998, pp. 193-198
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Two experiments each with two rates of feeding (maintenance and twice maintenance) were conducted during summer 1993/94 (Expt 1) and summer 1994/95 (Expt 2), at Massey University, New Zealand. Four sambar and four red deer, including stags and hinds aged 10–14 months, were used in each year. Animals were fed a pelleted diet (total N 30 g/kg DM; NDF 247 g/kg DM). Digestibility and nitrogen (N) balances were determined using deer metabolism cages, whilst methane production and heat production were determined using open circuit respiration calorimetry, with measurements made on each deer at both rates of feeding. Digestibility and metabolizability of energy were greater for sambar than for red deer in Expt 1 but not in Expt 2. Nitrogen retention, expressed as a proportion of N intake, was similar for sambar and red deer. Metabolizable energy required for maintenance (MEm) was 474 kJ kg W−0·75 d−1 for sambar deer and 567 kJ kg W−0·75 d−1 for red deer, whilst the efficiency of utilization of ME above maintenance (kg) was similar for sambar deer and red deer. These studies indicated that the sambar deer had lower rates of maintenance heat production than the red deer, which may explain the sambar's superior feed conversion measured in previous experiments. However, the two species utilized nitrogen with similar efficiency, when fed a high quality ration.
A Sustained Outbreak of Clostridium difficile in a General Hospital: Persistance of a Toxigenic Clone in Four Units
- Swapan K. Nath, James H. Thornley, Mary Kelly, Bernadette Kucera, Stephen L.W. On, Barry Holmes, Menelaos Costas
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- Journal:
- Infection Control & Hospital Epidemiology / Volume 15 / Issue 6 / June 1994
- Published online by Cambridge University Press:
- 02 January 2015, pp. 382-389
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- June 1994
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Objective:
To evaluate the endemicity and epidemiology of toxigenic Clostridium difficile in a sustained outbreak of antibiotic-associated diarrhea.
Setting:University-affiliated, 465-bed tertiary care teaching hospital with adjacent cancer clinic in Hamilton, Ontario.
Design:From August 8, 1991, through August 31, 1993, a total of 187 cases were investigated for epidemiologic analysis of toxigenic C difficile from stool cultures, to identify the endemic clone(s). To assess the nature of contamination, cultures of inanimate surfaces in the patient environment from the four most affected units (medical teaching, nonteaching medical, hematologic oncology, and the intensive care unit) were processed for C difficile. The 229 clinical strains and 24 environmental strains isolated were typed by numerical analysis of SDS-PAGE protein patterns.
Results:A majority (81%) of cases in the epidemiologic analysis were associated with a toxigenic electrophoretic (EP) type 1 C difficile that was identical to the strain first isolated from an index case that occurred 18 months before the start of this study. Culture and typing of the C difficile strains from the inanimate surfaces in the four most affected units showed that the patient environment was contaminated with the toxigenic EP type 1 organism. Six other strains that occurred infrequently among cases also were found in the environment.
Conclusions:A single predominant toxigenic clone has been implicated in a sustained outbreak of antibiotic-associated diarrhea that affected elderly patients. The “endemic” clone transmitted for the 25-month study period was linked to an index case shedding a toxigenic EP type 1 strain that occurred 21 months prior to the initial outbreak on the medical teaching unit. The patient environment in the affected units was found to be contaminated with the same clone, possibly due to shedding of organisms by fecally incontinent symptomatic patients. The extrinsic factors contributing to the endemic transmission of this one clone still are not well understood