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Effectiveness and cost-effectiveness of a cardiovascular risk prediction algorithm for people with severe mental illness
- E. Zomer, D. Osborn, I. Nazareth, R. Blackburn, A. Burton, S. Hardoon, R.I.G. Holt, M. King, L. Marston, S. Morris, R. Omar, I. Petersen, K. Walters, R.M. Hunter
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- European Psychiatry / Volume 33 / Issue S1 / March 2016
- Published online by Cambridge University Press:
- 23 March 2020, p. S191
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Introduction
Cardiovascular risk prediction tools are important for cardiovascular disease (CVD) prevention, however, which algorithms are appropriate for people with severe mental illness (SMI) is unclear.
Objectives/aimsTo determine the cost-effectiveness using the net monetary benefit (NMB) approach of two bespoke SMI-specific risk algorithms compared to standard risk algorithms for primary CVD prevention in those with SMI, from an NHS perspective.
MethodsA microsimulation model was populated with 1000 individuals with SMI from The Health Improvement Network Database, aged 30–74 years without CVD. Four cardiovascular risk algorithms were assessed; (1) general population lipid, (2) general population BMI, (3) SMI-specific lipid and (4) SMI-specific BMI, compared against no algorithm. At baseline, each cardiovascular risk algorithm was applied and those high-risk (> 10%) were assumed to be prescribed statin therapy, others received usual care. Individuals entered the model in a ‘healthy’ free of CVD health state and with each year could retain their current health state, have cardiovascular events (non-fatal/fatal) or die from other causes according to transition probabilities.
ResultsThe SMI-specific BMI and general population lipid algorithms had the highest NMB of the four algorithms resulting in 12 additional QALYs and a cost saving of approximately £37,000 (US$ 58,000) per 1000 patients with SMI over 10 years.
ConclusionsThe general population lipid and SMI-specific BMI algorithms performed equally well. The ease and acceptability of use of a SMI-specific BMI algorithm (blood tests not required) makes it an attractive algorithm to implement in clinical settings.
Disclosure of interestThe authors have not supplied their declaration of competing interest.
Healthcare utilization and monetary costs associated with agitation in UK care home residents with advanced dementia: a prospective cohort study
- A. Buylova Gola, S. Morris, B. Candy, S. Davis, M. King, N. Kupeli, G. Leavey, K. Moore, I. Nazareth, R. Omar, V. Vickerstaff, L. Jones, E. L. Sampson
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- Journal:
- International Psychogeriatrics / Volume 32 / Issue 3 / March 2020
- Published online by Cambridge University Press:
- 17 January 2020, pp. 359-370
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Objective:
Nearly half of care home residents with advanced dementia have clinically significant agitation. Little is known about costs associated with these symptoms toward the end of life. We calculated monetary costs associated with agitation from UK National Health Service, personal social services, and societal perspectives.
Design:Prospective cohort study.
Setting:Thirteen nursing homes in London and the southeast of England.
Participants:Seventy-nine people with advanced dementia (Functional Assessment Staging Tool grade 6e and above) residing in nursing homes, and thirty-five of their informal carers.
Measurements:Data collected at study entry and monthly for up to 9 months, extrapolated for expression per annum. Agitation was assessed using the Cohen-Mansfield Agitation Inventory (CMAI). Health and social care costs of residing in care homes, and costs of contacts with health and social care services were calculated from national unit costs; for a societal perspective, costs of providing informal care were estimated using the resource utilization in dementia (RUD)-Lite scale.
Results:After adjustment, health and social care costs, and costs of providing informal care varied significantly by level of agitation as death approached, from £23,000 over a 1-year period with no agitation symptoms (CMAI agitation score 0–10) to £45,000 at the most severe level (CMAI agitation score >100). On average, agitation accounted for 30% of health and social care costs. Informal care costs were substantial, constituting 29% of total costs.
Conclusions:With the increasing prevalence of dementia, costs of care will impact on healthcare and social services systems, as well as informal carers. Agitation is a key driver of these costs in people with advanced dementia presenting complex challenges for symptom management, service planners, and providers.
Follow Up of GW170817 and Its Electromagnetic Counterpart by Australian-Led Observing Programmes
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- I. Andreoni, K. Ackley, J. Cooke, A. Acharyya, J. R. Allison, G. E. Anderson, M. C. B. Ashley, D. Baade, M. Bailes, K. Bannister, A. Beardsley, M. S. Bessell, F. Bian, P. A. Bland, M. Boer, T. Booler, A. Brandeker, I. S. Brown, D. A. H. Buckley, S.-W. Chang, D. M. Coward, S. Crawford, H. Crisp, B. Crosse, A. Cucchiara, M. Cupák, J. S. de Gois, A. Deller, H. A. R. Devillepoix, D. Dobie, E. Elmer, D. Emrich, W. Farah, T. J. Farrell, T. Franzen, B. M. Gaensler, D. K. Galloway, B. Gendre, T. Giblin, A. Goobar, J. Green, P. J. Hancock, B. A. D. Hartig, E. J. Howell, L. Horsley, A. Hotan, R. M. Howie, L. Hu, Y. Hu, C. W. James, S. Johnston, M. Johnston-Hollitt, D. L. Kaplan, M. Kasliwal, E. F. Keane, D. Kenney, A. Klotz, R. Lau, R. Laugier, E. Lenc, X. Li, E. Liang, C. Lidman, L. C. Luvaul, C. Lynch, B. Ma, D. Macpherson, J. Mao, D. E. McClelland, C. McCully, A. Möller, M. F. Morales, D. Morris, T. Murphy, K. Noysena, C. A. Onken, N. B. Orange, S. Osłowski, D. Pallot, J. Paxman, S. B. Potter, T. Pritchard, W. Raja, R. Ridden-Harper, E. Romero-Colmenero, E. M. Sadler, E. K. Sansom, R. A. Scalzo, B. P. Schmidt, S. M. Scott, N. Seghouani, Z. Shang, R. M. Shannon, L. Shao, M. M. Shara, R. Sharp, M. Sokolowski, J. Sollerman, J. Staff, K. Steele, T. Sun, N. B. Suntzeff, C. Tao, S. Tingay, M. C. Towner, P. Thierry, C. Trott, B. E. Tucker, P. Väisänen, V. Venkatraman Krishnan, M. Walker, L. Wang, X. Wang, R. Wayth, M. Whiting, A. Williams, T. Williams, C. Wolf, C. Wu, X. Wu, J. Yang, X. Yuan, H. Zhang, J. Zhou, H. Zovaro
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- Publications of the Astronomical Society of Australia / Volume 34 / 2017
- Published online by Cambridge University Press:
- 20 December 2017, e069
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The discovery of the first electromagnetic counterpart to a gravitational wave signal has generated follow-up observations by over 50 facilities world-wide, ushering in the new era of multi-messenger astronomy. In this paper, we present follow-up observations of the gravitational wave event GW170817 and its electromagnetic counterpart SSS17a/DLT17ck (IAU label AT2017gfo) by 14 Australian telescopes and partner observatories as part of Australian-based and Australian-led research programs. We report early- to late-time multi-wavelength observations, including optical imaging and spectroscopy, mid-infrared imaging, radio imaging, and searches for fast radio bursts. Our optical spectra reveal that the transient source emission cooled from approximately 6 400 K to 2 100 K over a 7-d period and produced no significant optical emission lines. The spectral profiles, cooling rate, and photometric light curves are consistent with the expected outburst and subsequent processes of a binary neutron star merger. Star formation in the host galaxy probably ceased at least a Gyr ago, although there is evidence for a galaxy merger. Binary pulsars with short (100 Myr) decay times are therefore unlikely progenitors, but pulsars like PSR B1534+12 with its 2.7 Gyr coalescence time could produce such a merger. The displacement (~2.2 kpc) of the binary star system from the centre of the main galaxy is not unusual for stars in the host galaxy or stars originating in the merging galaxy, and therefore any constraints on the kick velocity imparted to the progenitor are poor.
Mothers’ self-reported grocery shopping behaviours with their 2- to 7-year-old children: relationship between feeding practices and mothers’ willingness to purchase child-requested nutrient-poor, marketed foods, and fruits and vegetables
- Kathryn Lively, Oluborode Babawale, David M Thompson, Amanda S Morris, Jennifer L Harris, Susan B Sisson, Marshall K Cheney, Karina R Lora
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- Journal:
- Public Health Nutrition / Volume 20 / Issue 18 / December 2017
- Published online by Cambridge University Press:
- 07 September 2017, pp. 3343-3348
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Objective
To assess relationships between mothers’ feeding practices (food as a reward, food for emotion regulation, modelling of healthy eating) and mothers’ willingness to purchase child-marketed foods and fruits/vegetables (F&V) requested by their children during grocery co-shopping.
DesignCross-sectional. Mothers completed an online survey that included questions about feeding practices and willingness (i.e. intentions) to purchase child-requested foods during grocery co-shopping. Feeding practices scores were dichotomized at the median. Foods were grouped as nutrient-poor or nutrient-dense (F&V) based on national nutrition guidelines. Regression models compared mothers with above-the-median v. at-or-below-the-median feeding practices scores on their willingness to purchase child-requested food groupings, adjusting for demographic covariates.
SettingParticipants completed an online survey generated at a public university in the USA.
SubjectsMothers (n 318) of 2- to 7-year-old children.
ResultsMothers who scored above-the-median on using food as a reward were more willing to purchase nutrient-poor foods (β=0·60, P<0·0001), mothers who scored above-the-median on use of food for emotion regulation were more willing to purchase nutrient-poor foods (β=0·29, P<0·0031) and mothers who scored above-the-median on modelling of healthy eating were more willing to purchase nutrient-dense foods (β=0·22, P<0·001) than were mothers with at-or-below-the-median scores, adjusting for demographic covariates.
ConclusionsMothers who reported using food to control children’s behaviour were more willing to purchase child-requested, nutrient-poor foods. Parental feeding practices may facilitate or limit children’s foods requested in grocery stores. Parent–child food consumer behaviours should be investigated as a route that may contribute to children’s eating patterns.
D063 Pharmaceutical Tablet Mapping Using Parallel Beam X-ray Diffraction
- S. Bates, C. H. Russell, D. A. Engers, K. R. Morris
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- Powder Diffraction / Volume 18 / Issue 2 / June 2003
- Published online by Cambridge University Press:
- 20 May 2016, p. 181
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The Keplerian orbit of G2
- L. Meyer, A. M. Ghez, G. Witzel, T. Do, K. Phifer, B. N. Sitarski, M. R. Morris, A. Boehle, S. Yelda, J. R. Lu, E. Becklin
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- Journal:
- Proceedings of the International Astronomical Union / Volume 9 / Issue S303 / October 2013
- Published online by Cambridge University Press:
- 22 May 2014, pp. 264-268
- Print publication:
- October 2013
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We give an update of the observations and analysis of G2 – the gaseous red emission-line object that is on a very eccentric orbit around the Galaxy's central black hole and predicted to come within 2400 RS in early 2014. During 2013, the laser guide star adaptive optics systems on the W. M. Keck I and II telescopes were used to obtain three epochs of spectroscopy and imaging at the highest spatial resolution currently possible in the near-IR. The updated orbital solution derived from radial velocities in addition to Br-γ line astrometry is consistent with our earlier estimates. Strikingly, even ∼ 6 months before pericenter passage there is no perceptible deviation from a Keplerian orbit. We furthermore show that a proposed “tail” of G2 is likely not associated with it but is rather an independent gas structure. We also show that G2 does not seem to be unique, since several red emission-line objects can be found in the central arcsecond. Taken together, it seems more likely that G2 is ultimately stellar in nature, although there is clearly gas associated with it.
On the past activity of Sgr A*
- G. Ponti, M. R. Morris, M. Clavel, R. Terrier, A. Goldwurm, S. Soldi, R. Sturm, F. Haberl, K. Nandra
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- Journal:
- Proceedings of the International Astronomical Union / Volume 9 / Issue S303 / October 2013
- Published online by Cambridge University Press:
- 22 May 2014, pp. 333-343
- Print publication:
- October 2013
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Recent X-ray emission events in the Galactic center would be expected to generate an X-ray reflection response within the surrounding clouds of the central molecular zone, in the Galactic disk and even, if powerful enough, in clouds outside our Galaxy. We review here the current constraints on Sgr A*'s past activity obtained through this method, with particular emphasis on the strong evidence that has been gathered for multiple X-ray flashes during the past few hundred years.
Contributors
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- By Ghazi Al-Rawas, Vazken Andréassian, Tianqi Ao, Stacey A. Archfield, Berit Arheimer, András Bárdossy, Trent Biggs, Günter Blöschl, Theresa Blume, Marco Borga, Helge Bormann, Gianluca Botter, Tom Brown, Donald H. Burn, Sean K. Carey, Attilio Castellarin, Francis Chiew, François Colin, Paulin Coulibaly, Armand Crabit, Barry Croke, Siegfried Demuth, Qingyun Duan, Giuliano Di Baldassarre, Thomas Dunne, Ying Fan, Xing Fang, Boris Gartsman, Alexander Gelfan, Mikhail Georgievski, Nick van de Giesen, David C. Goodrich, Hoshin V. Gupta, Khaled Haddad, David M. Hannah, H. A. P. Hapuarachchi, Hege Hisdal, Kamila Hlavčová, Markus Hrachowitz, Denis A. Hughes, Günter Humer, Ruud Hurkmans, Vito Iacobellis, Elena Ilyichyova, Hiroshi Ishidaira, Graham Jewitt, Shaofeng Jia, Jeffrey R. Kennedy, Anthony S. Kiem, Robert Kirnbauer, Thomas R. Kjeldsen, Jürgen Komma, Leonid M. Korytny, Charles N. Kroll, George Kuczera, Gregor Laaha, Henny A. J. van Lanen, Hjalmar Laudon, Jens Liebe, Shijun Lin, Göran Lindström, Suxia Liu, Jun Magome, Danny G. Marks, Dominic Mazvimavi, Jeffrey J. McDonnell, Brian L. McGlynn, Kevin J. McGuire, Neil McIntyre, Thomas A. McMahon, Ralf Merz, Robert A. Metcalfe, Alberto Montanari, David Morris, Roger Moussa, Lakshman Nandagiri, Thomas Nester, Taha B. M. J. Ouarda, Ludovic Oudin, Juraj Parajka, Charles S. Pearson, Murray C. Peel, Charles Perrin, John W. Pomeroy, David A. Post, Ataur Rahman, Liliang Ren, Magdalena Rogger, Dan Rosbjerg, José Luis Salinas, Jos Samuel, Eric Sauquet, Hubert H. G. Savenije, Takahiro Sayama, John C. Schaake, Kevin Shook, Murugesu Sivapalan, Jon Olav Skøien, Chris Soulsby, Christopher Spence, R. ‘Sri’ Srikanthan, Tammo S. Steenhuis, Jan Szolgay, Yasuto Tachikawa, Kuniyoshi Takeuchi, Lena M. Tallaksen, Dörthe Tetzlaff, Sally E. Thompson, Elena Toth, Peter A. Troch, Remko Uijlenhoet, Carl L. Unkrich, Alberto Viglione, Neil R. Viney, Richard M. Vogel, Thorsten Wagener, M. Todd Walter, Guoqiang Wang, Markus Weiler, Rolf Weingartner, Erwin Weinmann, Hessel Winsemius, Ross A. Woods, Dawen Yang, Chihiro Yoshimura, Andy Young, Gordon Young, Erwin Zehe, Yongqiang Zhang, Maichun C. Zhou
- Edited by Günter Blöschl, Technische Universität Wien, Austria, Murugesu Sivapalan, University of Illinois, Urbana-Champaign, Thorsten Wagener, University of Bristol, Alberto Viglione, Technische Universität Wien, Austria, Hubert Savenije, Technische Universiteit Delft, The Netherlands
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- Runoff Prediction in Ungauged Basins
- Published online:
- 05 April 2013
- Print publication:
- 18 April 2013, pp ix-xiv
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Unstable Richtmyer–Meshkov growth of solid and liquid metals in vacuum
- W. T. Buttler, D. M. Oró, D. L. Preston, K. O. Mikaelian, F. J. Cherne, R. S. Hixson, F. G. Mariam, C. Morris, J. B. Stone, G. Terrones, D. Tupa
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- Journal of Fluid Mechanics / Volume 703 / 25 July 2012
- Published online by Cambridge University Press:
- 13 June 2012, pp. 60-84
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We present experimental results supporting physics-based ejecta model development, where our main assumption is that ejecta form as a special limiting case of a Richtmyer–Meshkov (RM) instability at a metal–vacuum interface. From this assumption, we test established theory of unstable spike and bubble growth rates, rates that link to the wavelength and amplitudes of surface perturbations. We evaluate the rate theory through novel application of modern laser Doppler velocimetry (LDV) techniques, where we coincidentally measure bubble and spike velocities from explosively shocked solid and liquid metals with a single LDV probe. We also explore the relationship of ejecta formation from a solid material to the plastic flow stress it experiences at high-strain rates () and high strains (700 %) as the fundamental link to the onset of ejecta formation. Our experimental observations allow us to approximate the strength of Cu at high strains and strain rates, revealing a unique diagnostic method for use at these extreme conditions.
Contributors
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- By Charles E. Argoff, Gerard A. Banez, Samantha Boris-Karpel, Barbara K. Bruce, Alexandra S. Bullough, Annmarie Cano, Victor T. Chang, Elizabeth A. Clark, Daniel J. Clauw, June L. Dahl, Tam K. Dao, Amber M. Davis, Courtney L. Dixon, Michael H. Ebert, Robin M. Gallagher, Gerald W. Grass, Carmen R. Green, Jay Gunkelman, Bradford D. Hare, Jennifer A. Haythornthwaite, Jaclyn Heller Issner, W. Michael Hooten, Mark P. Jensen, Mark E. Jones, Robert D. Kerns, Raphael J. Leo, Morris Maizels, Mary E. Murawski, Brooke Myers-Sorger, Akiko Okifuji, Renata Okonkwo, John D. Otis, Stacy C. Parenteau, Laura E. Pence, Donald B. Penzien, Donna B. Pincus, Ellyn Poltrock Stein, Wendy J. Quinton, Jeanetta C. Rains, M. Carrington Reid, Thomas J. Romano, Jeffrey D. Rome, Robert L. Ruff, Suzanne S. Ruff, Steven H. Sanders, Ingra Schellenberg, John J. Sellinger, Howard S. Smith, Brenda Stoelb, Jon Streltzer, Mark D. Sullivan, Kimberly S. Swanson, Gabriel Tan, Stephen Thielke, Beverly E. Thorn, Cynthia O. Townsend, Dennis C. Turk, Stephanie C. Wallio, Lawrence J. Weinberger, David A. Williams, Hilary Wilson
- Edited by Michael H. Ebert, Yale University, Connecticut, Robert D. Kerns, Yale University, Connecticut
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- Behavioral and Psychopharmacologic Pain Management
- Published online:
- 10 January 2011
- Print publication:
- 25 November 2010, pp ix-xii
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Can maternal iodine supplementation improve twin- and triplet-born lamb plasma thyroid hormone concentrations and thermoregulation capabilities in the first 24–36 h of life?
- J. I. KERSLAKE, P. R. KENYON, K. J. STAFFORD, S. T. MORRIS, P. C. H. MOREL
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- The Journal of Agricultural Science / Volume 148 / Issue 4 / August 2010
- Published online by Cambridge University Press:
- 20 May 2010, pp. 453-463
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The present study investigated the effects of maternal plasma iodine concentration on twin- and triplet-born lamb plasma thyroid hormone concentrations, rectal temperature and maximal heat production. On pregnancy day 68 (P68), 16 twin- and 14 triplet-bearing ewes were randomly chosen from ewes that were injected intramuscularly with 1·5 ml of iodized peanut oil and ewes that were not. Selected ewes were grazed on ad libitum pasture from P68 until parturition. After parturition, lamb blood samples were collected within 5 min of birth and at 3, 12 and 24–36 h after birth. Lamb rectal temperatures were measured within 5 min of birth and at 1, 3 and 12 h after birth. Lamb body weight, crown–rump length and thoracic-girth circumference were recorded at 3 h of age, and the capability of the lamb to produce heat at 24–36 h of age was measured using indirect open-circuit calorimetry. Maternal iodine supplementation successfully increased plasma iodine concentrations of twin- and triplet-bearing ewes throughout pregnancy, but had no effect on the rectal temperature, thyroid hormone concentration and maximal heat production of twin- or triplet-born lambs. Compared with twin-born lambs, triplet-born lambs had lower birth weights, rectal temperatures and plasma T4 and T3 concentrations within 5 min of birth. Overall, under the conditions of the present study, maternal iodine supplementation offered no benefit in improving lamb heat production.
The effects of pasture availability for twin- and triplet-bearing ewes in mid and late pregnancy on ewe and lamb behaviour 12 to 24 h after birth
- R. A. Corner, P. R. Kenyon, K. J. Stafford, D. M. West, S. T. Morris, M. H. Oliver
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This experiment was conducted to evaluate the effect of offering ewes two different feeding levels, during mid and late pregnancy, on ewe and lamb behaviour 12 to 24 h after birth. Romney ewes, bearing twin (n = 80) or triplet foetuses (n = 56), were allocated to a pasture sward height of 2 or 4 cm between 70 and 107 days of pregnancy. In late pregnancy (day 107 to 147), half of the ewes were reallocated the alternate sward height, which produced four treatments: 2-2, 2-4, 4-2 and 4-4. Ewes were weighed on days 65, 92, 107 and 130 of pregnancy and lamb live weights were recorded 12 to 24 h after birth. Twelve to 24 h after birth the maternal behaviour score (MBS) of the ewes were determined, whilst their lambs were tagged. After the lambs were released, the behaviour of each ewe and her lambs was observed for 5 min. Ewe treatment and litter size had no effect on ewe MBS. However, as MBS increased (ewes stayed closer to lambs during tagging), ewes bleated less in a high-pitch and were quicker to make contact with their lamb. During the observation period, ewes in the 4-4 treatment had a greater percentage of their bleats in a low pitch (P < 0.05) than ewes in the 2-2 and 4-2 treatment (61.3% v. 41.3% and 38.8% low bleats, respectively) and more lambs born to 4-4 ewes (95%) bleated than lambs born to 2-2 ewes (84%; P < 0.05). However, lambs born to ewes in the 2-2 treatment bleated earlier than lambs in all other treatments (P < 0.05). Lambs born to 4-4 ewes were less likely (P < 0.05) to move towards their dam in order to make contact than lambs born to 2-2 or 4-2 ewes (3.1% v. 16.9% and 16.7%, respectively). These findings suggest that under the conditions of the present study, ewe nutrition had little effect on maternal behaviour. However, lambs born to ewes offered 2 cm pasture sward heights during mid and/or late pregnancy (2-2, 2-4 and 4-2 treatments) displayed behaviour that demonstrated greater ‘need’ whereas lambs born to ewes offered 4 cm during mid and late pregnancy sought less attention from their dam.
Brain anatomy and ageing in non-demented adults with Down's syndrome: an in vivo MRI study
- F. Beacher, E. Daly, A. Simmons, V. Prasher, R. Morris, C. Robinson, S. Lovestone, K. Murphy, D. G. M. Murphy
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- Journal:
- Psychological Medicine / Volume 40 / Issue 4 / April 2010
- Published online by Cambridge University Press:
- 12 August 2009, pp. 611-619
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Background
People with Down's syndrome (DS) are at high risk for developing dementia in middle age. The biological basis for this is unknown. It has been proposed that non-demented adults with DS may undergo accelerated brain ageing.
MethodWe used volumetric magnetic resonance imaging (MRI) and manual tracing to compare brain anatomy and ageing in 39 non-demented adults with DS and 42 healthy controls.
ResultsIndividuals with DS had significant differences in brain anatomy. Furthermore, individuals with DS had a significantly greater age-related reduction in volume of frontal, temporal and parietal lobes, and a significantly greater age-related increase in volume of peripheral cerebrospinal fluid (CSF).
ConclusionsNon-demented adults with DS have differences in brain anatomy and ‘accelerated’ ageing of some brain regions. This may increase their risk for age-related cognitive decline and Alzheimer's disease (AD).
The diversity, distribution and host-parasite associations of trypanosomes in Western Australian wildlife
- S. AVERIS, R. C. A. THOMPSON, A. J. LYMBERY, A. F. WAYNE, K. D. MORRIS, A. SMITH
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- Parasitology / Volume 136 / Issue 11 / September 2009
- Published online by Cambridge University Press:
- 07 August 2009, pp. 1269-1279
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Little is known regarding the diversity, distribution or host-parasite associations of Trypanosoma spp. in Australian wildlife. Here we report on an investigation based on divergence of the 18S rRNA gene of trypanosomes isolated from a range of hosts and varied geographical locations. A total of 371 individuals representing 19 species of native animals from 14 different locations were screened. In total, 32 individuals from 9 different species tested positive for the parasite. Phylogenetic analysis revealed considerable parasite diversity with no clear geographical distribution and no evidence of host specificity. In general, it appears that Australian Trypanosoma spp. are widespread, with several genotypes appearing in multiple host species and in varied locations including both mainland areas and offshore islands. Some host species were found to be susceptible to multiple genotypes, but no individuals were infected with more than a single isolate.
The use of Traps against Tsetse in West Africa
- K. R. S. Morris, M. G. Morris
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- Journal:
- Bulletin of Entomological Research / Volume 39 / Issue 4 / March 1949
- Published online by Cambridge University Press:
- 10 July 2009, pp. 491-528
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From 1940 up to the time of writing, experiments have been carried out in the savanna country in the north of the Gold Coast on the trapping of Glossina palpalis and G. tachinoides, which are the most important vectors of sleeping sickness in West Africa.
The habitat of these tsetse is described, with special reference to their feeding grounds, since those are the places where, trapping can be most effective and control of the flies is most desirable.
A new type of trap, the Animal trap, was designed to meet the feeding habits of the two species of tsetse whose main hosts in the country where sleeping sickness is prevalent are man and domestic animals.
The construction and maintenance of the Animal trap are described, the essential feature of which is a barrel-shaped body standing out well under good lighting and easily visible from all angles.
Traps with a standardised 2-feet-long body raised 1 foot from the ground combined optimum catching with convenience in construction and portability.
Light brown or khaki covering was slightly better than black, and rough material was decidedly better than smooth. Under poor lighting conditions these differences were less marked.
Comparisons over long periods showed that the Animal trap caught over 20 times as many flies as the Harris trap which was not at all suitable for G. palpalis; about 10 times as many flies as Swynnerton's A.S.B. trap; and about seven times as many flies as Chorley's Crinoline trap.
The correct siting of traps is of the greatest importance.
Traps catch well anywhere in fly-belt but are most effective in open feeding grounds such as ferries, fords, waterholes and animals' drinking places.
The regular presence of an abundance of hosts is the, most important single factor for good siting, and the nearer the traps can be placed to natural hosts the more effective they will prove.
Traps should be placed if possible with their axes at right angles to the regular lines of movement of the flies.
Good visibility of the trap from as wide an angle as possible is of great importance. Traps about five yards from the edge of the fly-belt catch twice as well as traps right at the margin of the bushes and considerably better than traps 40-50 yards out.
Good lighting, especially from overhead, is an advantage but by no means essential.
Good sites remain consistently good as long as the environment is unchanged, and bad sites remain bad.
There is a tendency for the numbers of flies caught to fall by as much as 70 per cent, during the first few weeks when traps are placed in undisturbed fly-belt. This is the effect of skimming off a part of the fly population in the immediate vicinity of the traps and does not represent a real reduction in population.
Comparison of tsetse catches by groups of five traps operating continuously, and by flyboys at the rate of 20 flyboy-days a month from parallel series of observations, gave the following facts for which explanations are offered.
Traps relative to flyboys are more efficient in taking G. tachinoides and less efficient in the cases of G. palpalis and G. morsitans. Flyboys, however, catch a higher proportion of female G. tachinoides but a lower proportion of females of the other two species.
It is considered that Animal traps represent the regular hosts of G. tachinoides and so attract non-feeding males as well as hungry flies of both sexes, whereas in the cases of G. palpalis and G. morsitans the traps represent something outside the range of their preferred hosts arid so attract only hungry flies bent on obtaining a meal.
Traps appear to have a greater efficiency relative to flyboys in groves and clearings where the numbers of flies are small, than in sites in or near heavy and extensive fly-belt with high fly populations. This is possibly the result of competition which would be most evident in small tsetse populations and which would act in favour of the continuously present traps.
There is a striking difference in the annual rhythms of catches by flyboys and by traps; the former showing a double-peaked curve with maxima at the beginning and in the middle of the wet season, the latter with a single peak towards the end of the dry season and a minimum during the rains.
The efficiency of traps relative to flyboys is greatest in January and least in September. In an estimate based on all the available data and comparing 150 trap-days with 20 flyboy-days monthly, the traps at their best were 10 times as good as the flyboys, and at their other extreme were as low as one-fourth of the flyboys' catches.
It is considered that this maximum efficiency in the dry season is not due to the flies' attraction to shade but that it is a complex result of the circumstances which bring about optimum conditions for trapping in the dry season, when the weather frequently puts flyboys at a disadvantage, and the most adverse conditions for trapping in the wet season when they enjoy certain advantages of mobility.
The seasonal rhythm of trap catches has demonstrated the presence of a considerably greater fly population in the height of the dry season than is suggested by the magnitude of boys' catches.
Three possibilities of trapping in the control of sleeping sickness are examined : (1) for extermination of the tsetse; (2) for reduction of the fly population; (3) for destruction of feeding flies in contact with people.
Regarding the first possibility it had been found that continuous catching by teams of four flyboys could eliminate G. palpalis and G. tachinoides from small groves after 8–12 weeks' continuous catching but that, since none of these groves was completely isolated, repopulation took place by immigration, especially in the wet season. Small numbers of traps, 5–7 to the acre, made no apparent difference to limited tsetse populations but concentrations of traps up to 20 to the acre brought about considerable reductions and checked the effects of immigration, but with no approach to extermination of the flies.
Eradication of the tsetse by traps is impossible but reduction of fly populations, if it can be effected over the main area of an epidemic, should, in theory, result in a partial control of trypanosomiasis.
Small groups of traps well sited in feeding grounds bring about considerable reductions in the numbers of active, hungry flies in contact with their hosts although hardly affecting the main fly community. This, in theory, will have a definite protective value to the community, enhanced by the fact that traps show increased catching powers when in close proximity to man and animals and that there is a tendency for people and tsetse to concentrate around waterholes (thus coming into the most intimate contact), during the dry season, the very time when traps are working at maximum efficiency.
It is in this protective role that traps seem to show their greatest possibilities for use in the control of sleeping sickness. The measure is applicable anywhere. It needs only small numbers of traps at each place where infection is being transmitted so that a reasonably big area could be covered economically. It might be a useful adjunct to clearings which fail to exclude the tsetse sufficiently. Traps so used might prove a valuable supplementary control-medium in places, such as the forest, where clearing is unlikely to be easy or cheap. Finally, experiment has shown that the retention of toxicity to Glossina of DDT-impregnated hessian exposed to the weather is sufficient to justify the application of DDT to the material covering the traps in order to increase their killing power.
The Biology of Microplectron fuscipennis, Zett. (Chalcid.), a Parasite of the Pine Sawfly (Diprion sertifer, Geoff.)
- K. R. S. Morris, E. Cameron
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- Journal:
- Bulletin of Entomological Research / Volume 26 / Issue 3 / September 1935
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- 10 July 2009, pp. 407-418
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Cocoons of Diprion sertifer, Geoffr., containing nearly eight millions Microplectron fuscipennis, Zett., were collected in Europe in 1934 and despatched to Canada for the control of the Spruce Sawfly, Diprion polytomum, Htg.
This parasite is widely distributed throughout Europe as a primary parasite of several species of pine sawflies of the genus Diprion.
A full account of the biology and a detailed description of the various stages is given.
In the laboratory it was reared in large numbers on the cocoons of D. polytomum from Canada.
Its chances of success in Canada depend on its acclimatisation and the accessibility and quantity of host material. Its tremendous fecundity and rapid rate of increase are greatly in its favour.
The Ecology of epidemic Sleeping Sickness. I.—The Significance of Location
- K. R. S. Morris
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- Bulletin of Entomological Research / Volume 42 / Issue 2 / September 1951
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- 10 July 2009, pp. 427-443
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A combination of historical, geographical, and epidemiological studies has given sufficient insight into the ecology of sleeping sickness to enable the main factors influencing the development and spread of an epidemic to be traced.
The evidence shows that in West Africa sleeping sickness is not primarily a disease of the forest, where tsetse flies are most abundant, but belongs essentially to the dry country in the north of the savanna woodland zone, where the earliest occurrences and severest outbreaks have been located.
The first mention of sleeping sickness comes from the upper Niger and dates back to the 14th century. By the beginning of the present century intense though localised epidemics were devastating parts of the Mossi, Grounsi and Lobi country of the upper Volta rivers. At this time the disease was unknown on the coast and of sporadic occurrence only in the forest. A severe trans-Volta epidemic covering 60,000 square miles, developed between 1924 and 1940, but was confined to the north of the inland savanna zone with nothing comparable in the forest.
The epidemic spread in three principal ways : (1) Outwards from original foci of infection because of the dynamic nature of the disease. This produced a concentration of infection around headwaters, a feature characteristic of advanced epidemics. (2) Through the agency of travellers, originally from north to south but subsequently in both directions : a rapid method of spread producing linear distribution of infection along trade routes. The tempo was greatly increased on the pacification and development of West Africa after 1900. (3) A gradual southward shift in the main epidemic zone appears to be resulting from a long-term change in the African climate which is combining with man's activities to produce a southerly extension of xerophytic vegetation types and a regression of forest.
The most important spread was that caused by the trading caravans, more especially the cola traders, who have been coming down to the cola-nut areas in the Ashanti forest from the big markets on the Niger and Upper Volta since the 11th century. The caravans were formerly very large, up to one or two thousand strong, and were frequently made up of Mossi and Grounsi from the territory that was so heavily infected by the beginning of the present century. It is certain that a continuous introduction of infection would have been taking place into the forest ever since trypanosomiasis was prevalent in the north, that is for 100 years at least. And infection has been known in the forest for about that period, yet always to a mild degree, never reaching epidemic form. It has been sought for, because conditions in the forest, with the vector Glossina palpalis in contact with every village and path, appeared to be ideal for the transmission of infection and this drew the particular attention of the early workers from 1908 onwards. But the most that could be found was a threatened epidemic in north-west Ashanti, very significantly centering on the big cola markets which formed the termini for the northern traders.
This historical evidence and the reasoning from epidemiology lead to the conclusion that conditions in the forest are not conducive to the development of epidemic sleeping sickness and that the low state of endemicity found there is maintained by the constant introduction of infection from the true epidemic areas in northern savanna.
From this conclusion arises a practical point of the greatest importance. If the sources from which infection is introduced into the forest could be eliminated the disease there should eventually die out and the tsetse, from the human point of view, would be harmless. Tsetse control in the forest may prove difficult and expensive, and if it is attempted by clearing this might end in the literal destruction of the forest. Such measures would be hard to justify, so many other factors of possibly greater importance than trypanosomiasis are involved, both the intrinsic value of a forest for its products and the wider value through its influence on climate, soil and water.
In formulating a plan for the control of sleeping sickness, the habits of both vectors, human as well as insect, should be considered. The tsetse plays a major role in the development of the high infection rates characterising the epidemic outbreaks in northern savanna ; the human vector distributes infection from these sources along trade routes and into the forest. The elimination of the disease at its source, in true epidemic centres, which can be most effectively accomplished by eradication of the tsetse, will check the distribution of infections to the secondary areas of lighter infection which could then be cleared up by quite minor control measures or might even disappear spontaneously.
This plan is now in operation in the Gold Coast. The validity of the arguments on which it was based is being shown by the results that are already apparent : the high rates of reduction in the epidemic areas and the pronounced lowering of infection in neighbouring, uncontrolled areas, more particularly in the forest region of north-west Ashanti where it is entered by a trade route coming from the previously heavily infected country.
The Bionomics and Importance of Glossina Longipalpis, Wied., in the Gold Coast
- K. R. S. Morris
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- Journal:
- Bulletin of Entomological Research / Volume 25 / Issue 3 / September 1934
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- 10 July 2009, pp. 309-335
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A detailed study of the bionomics of Glossina longipalpis, Wied., was undertaken at Takoradi, the principal port of the Gold Coast in West Africa, and lasted from February to September 1931.
The topography of this country is undulating; the vegetation is of Transition Forest type, intermediate in character between Rain Forest and Savannah Forest, and of an exceedingly dense, homogeneous nature, with a few small glades in the forest, and interrupted by large open marshes on the lower and flatter ground.
The climate is remarkably equable, with a low mean annual rainfall between 40 and 45 inches, but constantly high humidities, owing to the moisture-laden sea-winds. There is a double rainy season, the main rains from April to July, and a second shorter period of rainfall in October and November.
There is a rich mammalian fauna, with the exception of the larger game animals.
Three species of Glossina occur: G. longipalpis, Wied., the commonest, evenly distributed throughout the bush, and the only species dealt with in this paper; G. palpalis, R.-D., confined to water-courses and the edges of lagoons; and G. medicorum, Aust., rarely met with.
Two isolated fly-belts, identical in every way, were studied. In one, section A, flies were caught and killed daily; in the other, section B, the control area, the flies were liberated after noting the catches. By September, the tsetse population of A had been reduced to less than one-third of that of B, presumably the effects of catching and killing.
The main food hosts of this species were the bushbuck and duiker, ubiquitous in this forest. When these small game animals were driven out of a third fly-belt, section C, by farming and wood-cutting, the fly quickly and completely disappeared. This species was never found to feed on reptiles, although they were common in the fly-belts.
Meteorological observations in the open country and in the fly-belts showed a consistently lower temperature and higher humidity in the latter, as well as its greater equity in these factors. The movement of the fly into the open was apparently governed by humidity, the greatest movement taking place when the humidity of the open was within the normal range of fly-belt humidity.
By statistical methods, coefficients of correlation were determined for the fly's density-activity and various climatic factors of the fly-belt. The fly showed a high positive correlation with temperature, and a lower correlation with humidity, of which saturation deficit was a better index than atmometer evaporation. There was a significant correlation with sunshine, but none with rainfall. This correlation with humidity was mainly a temperature effect, as was also the correlation with sunshine. Temperature was evidently of major importance. There was a significant negative correlation between fly and relative humidity, measured with a wet and dry bulb hygrometer in a screen in the open.
All correlations were greatest when considered direct, the fly catches with simultaneous climatic readings, indicating that these factors influence the activity of the fly in this way, rather than its density. The fly was found to be inactive at temperatures below 74°F., with high humidities of 80 or 90 per cent. or over. This explains the major influence of temperature, shown by the methods of correlations. The temperature range in the fly-belt, during the period of observations, was close to the temperature significant for the fly's activity, and therefore variations produced marked reactions; the humidity range was much closer to the fly's optimum and therefore better tolerated.
There is marked daily rhythm in the fly's activity, which is only influenced by climate under extremely unfavourable conditions of temperature or humidity.
The distribution of G. longipalpis in the Gold Coast is dependent upon the humidity of the ecoclimate, rather than upon temperature. It occurs in three main vegetational types—Transition Forest, Inland Savannah Forest, and Coastal Savannah— where the range of humidities is between 50 and 80 per cent. R.H., and temperature between 75° and 85°F. It does not occur in the Rain Forest, where the relative humidity is constantly above 80 per cent., or in northern Savannah, where the humidity is as low as 30 per cent, in the dry season.
The main breeding season was from March to July with its maximum in May, at the height of the rains.
This species was found infected with Trypanosoma gambiense, T. congolense, and T. vivax at Takoradi, and is probably second in importance to G. palpalis as a vector of sleeping sickness in the Gold Coast, but at present of less importance than G. palpalis or G. tachinoides in the transmission of trypanosomiasis of stock.
The receding of the Ashanti forest and the present development of the Colony may cause even greater contact between this species of tsetse and man. The main policy for control should lie in improving and controlling the natives' methods of cultivating the bush. Farms should be as close to the village as possible, contiguous, and kept under cultivation, if possible, permanently. Clearings should be made of at least 100 yards width round bush villages, and of at least 200 yards width round important towns. Small clearings and isolated farms are considered a danger.
Problems in the Assessment of Tsetse Populations
- K. R. S. Morris
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- Journal:
- Bulletin of Entomological Research / Volume 52 / Issue 2 / June 1961
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- 10 July 2009, pp. 239-256
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A detailed tsetse-fly survey of 41,000 sq. miles in the inland savannah zone of the Gold Coast (Ghana) was completed in five years using an entirely African staff and working only six months each year.
This undertaking was made possible because studies of the species of Glossina concerned, G. palpalis (R.-D.), G. tachinoides Westw. and G. morsitans sub-morsitans Newst., had provided knowledge of their habitat, food-hosts and activity rhythm, on which could be based a standard yet simple survey technique, within the compass of independent native teams.
The restricted activity rhythm of the flies, subject to both daily and seasonal variations, meant that nothing less than a ‘day’ of eight hours of observation could be accepted as a valid sampling unit.
With tsetse flies at low densities, a day's search was inadequate, giving only 40 per cent, reliability compared with 6-day observations. Four days' search gave 90 per cent, reliability and was adopted as the minimum period of search.
Each survey team was under the charge of a Kecorder or Field Assistant, with fly-boys devoting the whole of their time to catching. Comparability of survey data was ensured by keeping teams to the same size, two fly-boys being the optimum, since it was found that the size of the catch was not always proportionate to the number of boys, the relationship varying according to a variety of factors.
In surveying G. palpalis and G. tachinoides the ‘picket’ system of more or less stationary teams, measuring their catches by the ‘day ’, was found overwhelmingly superior to the ‘fly-round’ technique.
The survey procedure described for savannah woodland country was not effective in sampling G. nigrofusca Newst. in the Ashanti forest or G. longipalpis Wied. in the coastal savannah, but Morris's ‘animal’ traps were found to take both species readily in places where they had not been detected or only occasionally caught by fly-boys. Experiments showed that trap catches were superior, both numerically and in giving a more representative sample of the tsetse population present. It was also shown that trapping could be a valuable means of studying the biology of these two ‘man-shy’ species of Glossina. Traps were also effective in taking G. pallicera Big. and G. medicorum Aust.
The greater value of traps compared with fly-boys as a means of sampling various species of tsetse fly is discussed, and suggestions are put forward for developing trapping as a method of survey.
The type of trap employed is regularly catching insects of several other families, including a number of species among the Tabanidae, and of several other orders.
The Ecology of Epidemic Sleeping Sickness II.—The Effects of an Epidemic.
- K. R. S. Morris
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- Journal:
- Bulletin of Entomological Research / Volume 43 / Issue 2 / July 1952
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- 10 July 2009, pp. 375-396
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The most obvious effect of sleeping sickness is depopulation, which can be occasioned directly, through mortality from the disease, and indirectly, through a lowering of the reproductive rate of a community because of induced sterility and increased infant mortality.
The problem was studied in the north of the Gold Coast and the neighbouring French Upper Volta Territory, where severe epidemics have occurred, in localised form since at least the middle of last century, and in widespread form during the past 30 years. The vectors have been the riverine tsetse Glossina palpalis and G.tachinoides.
A close correlation was found to exist between the incidence of sleeping sickness and the population trend with a marked depopulating effect coming in at infection rates above 3 per cent. It was also found that both the rates of trypanosomiasis infection and the extent of depopulation showed closely similar relationships to the proximity of affected villages to the nearest flybelt.