124 results on '"R. Aitken"'
Search Results
2. Fixed-intensity exercise tests to measure exertional dyspnoea in chronic heart and lung populations: a systematic review
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Tanya Palmer, Steven J. Obst, Craig R. Aitken, James Walsh, Surendran Sabapathy, Lewis Adams, and Norman R. Morris
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Diseases of the respiratory system ,RC705-779 - Abstract
Introduction Exertional dyspnoea is the primary diagnostic symptom for chronic cardiopulmonary disease populations. Whilst a number of exercise tests are used, there remains no gold standard clinical measure of exertional dyspnoea. The aim of this review was to comprehensively describe and evaluate all types of fixed-intensity exercise tests used to assess exertional dyspnoea in chronic cardiopulmonary populations and, where possible, report the reliability and responsiveness of the tests. Methods A systematic search of five electronic databases identified papers that examined 1) fixed-intensity exercise tests and measured exertional dyspnoea, 2) chronic cardiopulmonary populations, 3) exertional dyspnoea reported at isotime or upon completion of fixed-duration exercise tests, and 4) published in English. Results Searches identified 8785 papers. 123 papers were included, covering exercise tests using a variety of fixed-intensity protocols. Three modes were identified, as follows: 1) cycling (n=87), 2) walking (n=31) and 3) other (step test (n=8) and arm exercise (n=2)). Most studies (98%) were performed on chronic respiratory disease patients. Nearly all studies (88%) used an incremental exercise test. 34% of studies used a fixed duration for the exercise test, with the remaining 66% using an exhaustion protocol recording exertional dyspnoea at isotime. Exertional dyspnoea was measured using the Borg scale (89%). 7% of studies reported reliability. Most studies (72%) examined the change in exertional dyspnoea in response to different interventions. Conclusion Considerable methodological variety of fixed-intensity exercise tests exists to assess exertional dyspnoea and most test protocols require incremental exercise tests. There does not appear to be a simple, universal test for measuring exertional dyspnoea in the clinical setting. more...
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- 2023
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Catalog
3. Simultaneous Optimization of <scp> MP2RAGE T 1 </scp> ‐weighted ( <scp>UNI</scp> ) and FLuid And White matter Suppression ( <scp>FLAWS</scp> ) brain images at <scp>7T</scp> using Extended Phase Graph ( <scp>EPG</scp> ) Simulations
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Ayşe Sıla Dokumacı, Fraser R. Aitken, Jan Sedlacik, Pip Bridgen, Raphael Tomi‐Tricot, Ronald Mooiweer, Katy Vecchiato, Tom Wilkinson, Chiara Casella, Sharon Giles, Joseph V. Hajnal, Shaihan J. Malik, Jonathan O'Muircheartaigh, and David W. Carmichael more...
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Radiology, Nuclear Medicine and imaging - Published
- 2022
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4. Environmental, social and reproductive factors influence the risk–reward trade-off in a group-living fish
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Marian Y. L. Wong, Leigha R. Aitken, Amanda L. Beasley, Stephen G. Morris, and Anna Scott
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Aquatic Science - Abstract
Animals are faced with a fundamental risk-reward trade-off when making decisions about foraging in the presence of predation, yet little is known about how social, reproductive and environmental factors mediate this trade-off. In the marine environment, anemonefishes provide a model system for investigating the determinants of risk–reward trade-offs, because they live in size- and sex-structured groups within protective sea anemones tentacles, yet feed predominantly in the water column where they are at risk of predation. Furthermore, exposure to changing tides means the availability of planktonic food covaries with their risk of predation. Therefore, we examined how tide, sex and status, and the presence of eggs influenced the time that Amphiprion mccullochi spent at different distances from their anemone, a proxy for foraging effort and predation risk. We found that individuals significantly adjusted their time spent far and close to the anemone depending on the tide, status and the presence of eggs, and that these adjustments can be explained in light of threat sensitive behaviour. This study illustrates the relative importance of environmental and social factors on intraspecific variation in foraging and antipredator behaviour and bolsters our understanding of the decision’s individuals make to balance the costs and benefits of foraging over temporal and spatial scales. more...
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- 2022
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5. Risk factors for laminitis and nonsurvival in acute colitis: Retrospective study of 85 hospitalized horses (2011‐2019)
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Daniela Luethy, Darko Stefanovski, Maia R. Aitken, and Rose Feldman
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medicine.medical_specialty ,salmonellosis ,040301 veterinary sciences ,Veterinary medicine ,coronavirus ,Standard Article ,030204 cardiovascular system & hematology ,Gastroenterology ,0403 veterinary science ,Foot Diseases ,03 medical and health sciences ,0302 clinical medicine ,Risk Factors ,Internal medicine ,SF600-1100 ,medicine ,Odds Ratio ,neorickettsiosis ,Animals ,Horses ,Colitis ,Acute colitis ,Retrospective Studies ,General Veterinary ,business.industry ,Proportional hazards model ,Hazard ratio ,Retrospective cohort study ,04 agricultural and veterinary sciences ,Odds ratio ,Laminitis ,medicine.disease ,Confidence interval ,Standard Articles ,EQUINE ,Horse Diseases ,business - Abstract
Background Acute colitis is a serious cause of morbidity and death in horses. Recent studies have compared clinical features of coronavirus and salmonellosis, but no study has compared clinical features of enteric salmonellosis, coronavirus, and neorickettsiosis. Hypothesis/Objectives To identify risk factors for laminitis and nonsurvival to discharge in horses with enteric salmonellosis, coronavirus, or neorickettsiosis. Animals Eighty‐five horses hospitalized for acute colitis from 2011 to 2019. Methods Retrospective case series. Medical record review (2011‐2019) of adult (≥2 years) horses with colitis. Primary outcomes were laminitis and survival to discharge. Multivariable logistic regression was performed to assess association between variables and the development of laminitis. Stepwise Cox regression was performed to assess association between variables and survival. Results Seventeen of 85 (20%) horses developed laminitis during hospitalization. Neorickettsiosis cases (11/26, 42%) were more likely to develop laminitis than coronavirus (0/16, 0%) cases (odds ratio [OR] 24.48; 95% confidence interval [CI]: 1.33‐451.74, P = .03). There was no significant difference in laminitis between salmonellosis and neorickettsiosis cases (OR 0.27; 95% CI: 0.07‐1.07, P = .06). Admission heart rate (OR 1.08; 95% CI: 1.02‐1.15, P = .01), total solids (OR 0.17; 95% CI: 0.06‐0.54, P = .003), band neutrophils (OR 1248.47; 95% CI: 6.62‐235 540, P = .008), and bicarbonate concentration (OR 0.68; 95% CI: 0.5‐0.92, P = .01) were predictive of development of laminitis during hospitalization. Sixty‐three of 85 (74%) horses survived to discharge: 16/16 (100%) coronavirus cases, 17/26 (65%) neorickettsiosis cases, 14/20 (70%) salmonellosis cases, and 16/23 (70%) unknown cases. Packed cell volume (hazard ratio [HR] 1.17; 95% CI: 1.09‐1.26, P more...
- Published
- 2021
6. Multi-Institutional Retrospective Case-Control Study Evaluating Clinical Outcomes of Foals with Small Intestinal Strangulating Obstruction: 2000–2020
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Sara J. Erwin, Marley E. Clark, Julie E. Dechant, Maia R. Aitken, Diana M. Hassel, Anthony T. Blikslager, and Amanda L. Ziegler
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General Veterinary ,animal diseases ,parasitic diseases ,horse ,colic ,foal ,ischemia ,small intestinal strangulating obstruction ,surgery ,Animal Science and Zoology - Abstract
Lower survival has been reported in foals than adults with small intestinal strangulating obstruction (SISO), but age-dependent outcomes have not been examined directly. Hospital records were collected from five US academic referral hospitals. It was hypothesized that foals would exhibit lower survival than case-matched adults. Foal cases 6-months-of-age or younger, and adult cases between 2- and 20-years-of-age were collected. Data revealed 24 of 25 (96.0%) foals and 66 of 75 (88.0%) adults that were recovered from surgery for SISO survived to hospital discharge. Sixteen of the total 41 (39.0%) foals studied were euthanized intraoperatively, whereas 30 of 105 (28.6%) adults were euthanized intraoperatively. Common lesions in foals that were recovered from surgery were volvulus (n = 13) and intussusception (n = 5), whereas common lesions in adults were volvulus (n = 25) and strangulating lipoma (n = 23). This study was limited by incomplete medical records, relatively small sample size, and lack of long-term follow-up. Unexpectedly, short-term survival tended to be higher in foals than adults and may have been partly driven by case selection prior to referral or surgery or decision-making intraoperatively. More optimism toward surgical treatment of foals with SISO may be warranted. more...
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- 2022
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7. Aitken's seeds, 1943
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Chas. R. Aitken (Firm), Henry G. Gilbert Nursery and Seed Trade Catalog Collection, U.S. Department of Agriculture, National Agricultural Library, Chas. R. Aitken (Firm), and Henry G. Gilbert Nursery and Seed Trade Catalog Collection more...
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Catalogs ,Delhi ,New York (State) ,Seed industry and trade ,Seeds ,Vegetables - Published
- 1943
8. Aitken's seeds, 1942
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Chas. R. Aitken (Firm), Henry G. Gilbert Nursery and Seed Trade Catalog Collection, U.S. Department of Agriculture, National Agricultural Library, Chas. R. Aitken (Firm), and Henry G. Gilbert Nursery and Seed Trade Catalog Collection more...
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Catalogs ,Delhi ,New York (State) ,Seed industry and trade ,Seeds ,Vegetables - Published
- 1942
9. Aitken's seeds, 1941
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Chas. R. Aitken (Firm), Henry G. Gilbert Nursery and Seed Trade Catalog Collection, U.S. Department of Agriculture, National Agricultural Library, Chas. R. Aitken (Firm), and Henry G. Gilbert Nursery and Seed Trade Catalog Collection more...
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Catalogs ,Delhi ,New York (State) ,Seed industry and trade ,Seeds ,Vegetables - Published
- 1941
10. Aitken's seeds, 1940
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Chas. R. Aitken (Firm), Henry G. Gilbert Nursery and Seed Trade Catalog Collection, U.S. Department of Agriculture, National Agricultural Library, Chas. R. Aitken (Firm), and Henry G. Gilbert Nursery and Seed Trade Catalog Collection more...
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Catalogs ,Delhi ,New York (State) ,Nursery stock ,Seeds - Published
- 1940
11. Special Section on Emerging Trends and Design Paradigms for Memory Systems and Storage
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R. Aitken, Cecilia Metra, and 75. R. Aitken, C. Metra
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Random access memory ,Computer science ,business.industry ,Memory systems ,Computer security ,computer.software_genre ,Computer Science Applications ,Human-Computer Interaction ,N/A ,Computer Science (miscellaneous) ,Special section ,Resilience (network) ,Internet of Things ,business ,computer ,Information Systems - Abstract
Welcome to all readers of this special section addressingchallenges and innovative design and implementation strate-gies for memory systems and storage.As is well-known, the continued scaling of silicon-basedmicroelectronics technology, as well as the emergence ofnew, non-silicon-based technologies, enable increasingsystem complexity and performance, paving the way forapplications that had been unthinkable a few years ago. Atthe same time, increasingly diverse Internet of Things (IoT)applications and Autonomous Intelligent Systems demandthat an ever-increasing amount of data be correctly and rap-idly stored and accessed, posing new challenges to memorysystems and storage elements.In this special section we address issues related to design,test, reliability, resilience and availability of memory systemsand storage. more...
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- 2019
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12. Epiglottic abnormalities in mature nonracehorses: 23 cases (1990–2009)
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Eric J. Parente and Maia R. Aitken
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medicine.medical_specialty ,General Veterinary ,Soft palate ,medicine.diagnostic_test ,Medical treatment ,business.industry ,medicine.disease ,Epiglottis ,Endoscopy ,Surgery ,Laryngeal Diseases ,Chronic cough ,medicine.anatomical_structure ,Granuloma ,medicine ,Animals ,Horse Diseases ,Cyst ,Horses ,medicine.symptom ,business ,Airway ,Retrospective Studies ,Recurrent airway obstruction - Abstract
Objective—To identify history, clinical signs, endoscopic findings, treatment, and outcome of mature (> 8 years old) nonracehorses with epiglottic abnormalities. Design—Retrospective case series. Animals—23 horses with an epiglottic abnormality. Procedures—Medical records of horses examined between 1990 and 2009 because of an epiglottic abnormality were reviewed to obtain information on signalment, history, clinical signs, clinical examination findings, upper airway endoscopic findings, diagnosis, surgical procedure, clinical management, postoperative care, and outcome. Results—Mean ± SD age was 16 ± 6 years (range, 9 to 30 years). Sixteen of the 23 (70%) horses had a primary complaint of a chronic cough. Thirteen (57%) horses had epiglottic entrapment, 7 (30%) had a subepiglottic granuloma, and 3 (13%) had a subepiglottic cyst. All 23 horses were treated surgically, with 1 (4%) requiring further surgical treatment. Follow-up examinations and conversations with owners indicated resolution of the primary complaint in 17 of the 23 (74%) horses, with 4 (24%) requiring prolonged medical treatment because of postoperative subepiglottic inflammation. Of the 6 horses without complete resolution, 4 (67%) had signs of recurrent airway obstruction and 2 (33%) developed persistent dorsal displacement of the soft palate following laryngotomy and subepiglottic membrane resection. Conclusions and Clinical Relevance—Results suggested that coughing is a common complaint in mature nonracehorses with epiglottic abnormalities. Therefore, upper airway endoscopy is recommended in the evaluation of older horses with a cough. Surgical treatment can be beneficial in most horses, with some requiring further postoperative medical treatment. more...
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- 2011
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13. The aerobic microflora of the Scotch haggis
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N. A. Halls, Katherine H. R. Aitken, and D. Henry
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biology ,Food spoilage ,Bacillus ,biology.organism_classification ,medicine.disease_cause ,Industrial and Manufacturing Engineering ,Microbiology ,Lactic acid ,chemistry.chemical_compound ,chemistry ,Lactobacillus ,medicine ,Food science ,Staphylococcus ,Bacteria ,Food Science - Abstract
Summary The aerobic microflora of freshly purchased Scotch haggis was dominated by organisms identified with Bacillus. Lactobacillus, Staphylococcus, yeasts and moulds were also detected in significant numbers. On storage at 5,30 or 37°C for 3 weeks, spoilage of the haggis was accompanied by a drop in pH and a tenfold increase in numbers of general contaminants and lactic acid bacteria. more...
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- 2007
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14. Abstracts of the 28th Annual Meeting of the United Kingdom Environmental Mutagen Soceity, August 3–5, 2005 at the University of Bradford, UK
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R. Aitken, Shaun D. Roman, and John E. Schjenken
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Gene expression profiling ,Health, Toxicology and Mutagenesis ,Genetics ,Biology ,Toxicology ,Molecular biology ,Genetics (clinical) ,Germline - Published
- 2005
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15. Review Article
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R Aitken
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Geography, Planning and Development ,Development - Published
- 2000
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16. Non-operative management of non-destructive extra-peritoneal rectal injury
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M F, Harry, J M, Plummer, M, Stubbs, R, Aitken, and P, Williams
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Male ,Rectum ,Humans ,Wounds, Gunshot ,Middle Aged - Abstract
This is a case report of extra-peritoneal rectal injury, secondary to a gunshot, that was managed non-operatively. A 57-year old male presented with a single gunshot to the right buttock and had blood per rectum. Extra-peritoneal rectal injuries were seen on proctoscopy and he had no genitourinary injury. He was managed successfully without rectal injury repair orfaecal stream diversion. more...
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- 2012
17. Generation of native bovine mAbs by phage display
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B. W. O’Neil, P. M. O’Brien, R. Aitken, and M. S. Campo
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Phage display ,Genetic Vectors ,Molecular Sequence Data ,Enzyme-Linked Immunosorbent Assay ,Biology ,Polymerase Chain Reaction ,Molecular Immunology ,Immunoglobulin Fab Fragments ,Immune system ,Antigen ,Immunity ,Animals ,Genomic library ,Bacteriophages ,Amino Acid Sequence ,Pathogen ,Gene Library ,Glutathione Transferase ,Multidisciplinary ,Antibodies, Monoclonal ,Sequence Analysis, DNA ,Biological Sciences ,Virology ,biology.protein ,Cattle ,Lymph Nodes ,Antibody ,Sequence Alignment - Abstract
Modeling of disease pathogenesis and immunity often is carried out in large animals that are natural targets for pathogens of human or economic relevance. Although murine mAbs are a valuable tool in identifying certain host/pathogen interactions, progress in comparative immunology would be enhanced by the use of mAbs isolated from the host species. Such antibodies would reflect an authentic host immune response to infection or vaccination, and as they are host derived, would allow the application ofin vivoexperiments that previously have been unrealizable in large animals because of induction of an antispecies immune response. The advent of antibody phage display technology provides a way of producing host-derived mAbs in animals where the molecular genetics of Ig formation are known. Exploiting recent advances in the molecular immunology of cattle, we report here the design of an optimized phage display vector, pComBov, for the construction of combinatorial libraries of bovine Ig antigen-binding fragments (Fab) of native sequence. By using this system, we initially have generated and characterized a panel of bovine mAbs against a model antigen glutathioneS-transferase. The isolated mAbs showed features typical of bovine Igs and recognized glutathioneS-transferase with high specificity in ELISA and by Western blotting. The pComBov expression system can be readily adapted for the preparation of libraries from related ruminant species and advances the use of monoclonal reagents derived in this way for comparative studies in animals of economic importance. more...
- Published
- 1999
18. The Rapunzel syndrome. Report of a case and review of the literature
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N D, Duncan, R, Aitken, S, Venugopal, W, West, and R, Carpenter
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Bezoars ,Ileum ,Child, Preschool ,Humans ,Female ,Intussusception - Abstract
The Rapunzel Syndrome, a rare manifestation of trichobezoar, occurs when bolus gastrointestinal obstruction is produced by an unusual trichobezoar with a long tail that extends to or beyond the ileocaecal valve. A five-year-old Jamaican girl presented with this abnormality and was found at laparotomy also to have an ileo-ileal intussusception. For the Rapunzel Syndrome, we recommend bezoar extraction at laparotomy via multiple enterotomies. In addition, psychiatric evaluation and therapy is essential due to the commonly associated finding of underlying emotional stress. more...
- Published
- 1994
19. A COLLABORATIVE EUROPEAN STUDY OF PERSONAL INHALABLE AEROSOL SAMPLER PERFORMANCE.
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Kenny, L. C., R., Aitken, C., Chalmers, Fabriès, J. F., Gonzalez-Fernandez, E., Kromhout, H., Lidén, G., Mark, D., Riediger, G., and Prodi, V.
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AEROSOL sampling ,AEROSOLS ,WORK environment ,PERFORMANCE standards ,SAFETY - Abstract
Following the adoption of new international sampling conventions for inhalable, thoracic and respirable aerosol fractions, a working group of Comité Européen de Normalisation (CEN) drafted a standard for the performance of workplace aerosol sampling instruments. The present study was set up to verify the experimental, statistical and mathematical procedures recommended in the draft performance standard and to check that they could be applied to inhalable aerosol samplers. This was achieved by applying the tests to eight types of personal inhalable aerosol sampler commonly used for workplace monitoring throughout Europe. The study led to recommendations for revising the CEN draft standard, in order to simplify the tests and reduce their cost. However, some further work will be needed to develop simpler test facilities and methods. Several of the samplers tested were found to perform adequately with respect to the inhalable sampling convention, at least over a limited range of typical workplace conditions. In general the samplers were found to perform best in low external wind speeds, which are the test conditions thought to be closest to those normally found in indoor workplaces. The practical implementation of the CEN aerosol sampling conventions requires decisions on which sampling instruments to use, estimation of the likely impact that changing sampling methods could have on apparent exposures, and adjustment where necessary of exposure limit values. The sampler performance data obtained in this project were affected by large experimental errors, but are nevertheless a useful input to decisions on how to incorporate the CEN inhalable sampling convention into regulation, guidance and occupational hygiene practice. Crown Copyright © 1997 Published by Elsevier Science Ltd. [ABSTRACT FROM AUTHOR] more...
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- 1997
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20. FLAVOR ASSOCIATED WITH FISH MEAL IN DIETS FED TO BROILER CHICKENS
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W. F. Lamoreux, J. R. Aitken, F. G. Proudfoot, and Paul Dean
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Taste ,Fish meal ,Seasoning ,Food Animals ,Broiler ,food and beverages ,Animal Science and Zoology ,Food science ,Biology ,Flavor - Abstract
Diets containing varying levels of fish meal (3–19%) were fed to broiler chickens representing male and female birds of four different genotypes. After slaughter and processing, sample birds were roasted without seasoning, and portions of skin, breast meat and thigh meat were submitted to a taste panel of nine judges. Each portion was tested by asking one of the judges to identify it when it was presented along with two comparable portions taken from a control bird. There were 720 such triangle tests, comprised of six replicate tests within each of the 120 subclasses denned by genotype, sex, nutritional treatment and type of tissue.Flavor differences between birds fed 3% and 9% fish meal were detected with a frequency which was highly significant in skin and breast meat, but in thigh meat there was no significant effect on flavor until the level of fish meal reached 14%. Neither sex nor genotype had any influence on the detection of flavor differences. The practical significance of these findings is discussed. more...
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- 1969
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21. Studies on the Influence of Ascorbic Acid on Shell Quality
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J. R. Hunt and J. R. Aitken
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food.ingredient ,chemistry.chemical_element ,General Medicine ,Calcium ,Ascorbic acid ,Oxygen ,Fish meal ,food ,chemistry ,Skimmed milk ,Animal Science and Zoology ,Composition (visual arts) ,Food science ,Eggshell ,Thyroid function - Abstract
CURRENT interest in the inclusion of ascorbic acid in laying rations was stimulated by the report of Thornton and Moreng (1958) that dietary ascorbic acid reduced the decline of egg shell quality experienced under high environmental temperatures. The earlier negative results of Heywang and Kemmerer (1955) might be explained by their higher (20 times) level of ascorbic acid supplementation. That high environmental temperature is detrimental to egg shell quality has been demonstrated frequently (Bennion and Warren, 1933; Warren and Schnepel, 1940; Wilhelm, 1940; and others). Why this is so has not been clearly indicated. Conrad (1939) and later Mueller (1959), demonstrated that high temperatures depressed serum calcium but Mueller also found a negative correlation between egg shell thickness and serum calcium level. Thornton and Moreng (1959) believe thyroid function is depressed by high temperatures and stimulated by ascorbic acid as they observed that oxygen consumption increased and egg shell quality … more...
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- 1962
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22. Performance of Commercial Broiler Genotypes on Fish Meal Diets with a Charcoal Supplement
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J. R. Aitken, W. F. Lamoreux, and F. G. Proudfoot
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Protein fish ,Meal ,digestive, oral, and skin physiology ,Broiler ,food and beverages ,General Medicine ,Biology ,Body weight ,Protein content ,Fish meal ,visual_art ,visual_art.visual_art_medium ,PROTEIN SUPPLEMENT ,Animal Science and Zoology ,Food science ,Charcoal - Abstract
IN maritime areas where fish meal is the cheapest source of protein, it would be desirable to use it exclusively as the protein supplement in poultry rations. This is quite feasible in laying diets (Smith and Chancey, 1967) where the high mineral content of the fish meal is an advantage and the level required is not high enough to cause concern about off flavors in the edible products. Broiler diets require much higher levels of protein than laying diets. The exclusive use of fish meal to supply this extra protein can bring mineral levels well above optimum, and cause concern about the possibility of undesirable flavors in the meat. Hardin et al. (1964) fed diets containing 5, 10 and 15% of a solvent extracted 70% protein fish meal to broilers. They found no significant differences in growth rate on the three diets. Waldroup et al. (1965) replaced 25, 50, 75… more...
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- 1971
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23. Protein Energy Relationships in the Diet of the Chick
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A. R. Robblee, G.C. Hodgson, J. Biely, J. B. O’Neil, and J. R. Aitken
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High energy ,animal structures ,Calorie ,Protein–energy malnutrition ,General Medicine ,Biology ,medicine.disease ,Body weight ,Feed conversion ratio ,Protein content ,Normal growth ,medicine ,Animal Science and Zoology ,Growth rate ,Food science - Abstract
THE REPORT of Scott et al. (1947) has stimulated a great deal of work on the utilization of high energy rations for the production of broilers. Hill and Dansky (1950) indicated a relationship between the level of protein and productive energy in the diet of chicks. These authors observed a reduced growth rate in chicks fed a diet containing less than 20% protein but high in productive energy. Normal growth was obtained when the level of productive energy was reduced. Combs and Romoser (1955) concluded that the growth rate in broilers to 7 weeks of age was not affected until more than 41.5–42.0 Calories of productive energy per pound of feed were supplied for each pound of protein. The influence of different productive energy to protein ratios upon the growth and feed efficiency of chicks has been reported by many workers. Among these, Vondell et al. (1958) concluded that … more...
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- 1962
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24. THE PROTEIN REQUIREMENTS OF LAYING HENS IN FLOOR PENS AND INDIVIDUAL CAGES
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J. R. Aitken and T. M. MacIntyre
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Protein content ,Animal science ,Low protein ,Dietary protein ,Calorie ,Food Animals ,Animal Science and Zoology ,Biology ,Eggshell ,Cage ,Body weight ,Laying - Abstract
Diets varying in protein content from 10.9 to 16.7 per cent were fed over a 336-day laying period to hens in both floor pens and individual laying cages. All rations were approximately iso-caloric, the mean productive energy value being 825 Calories per pound. Each ration was fed to 200–240 hens in four floor pens and to 90–96 hens in individual cages.A crude protein level of 13 per cent of the diet proved adequate for egg production, but egg weights and body weights were improved when the dietary protein was increased. Egg shell quality was highest on low protein diets. Interior egg quality was not affected by the protein level in the diet.On comparable diets, birds in individual laying cages laid fewer eggs and consumed less feed than birds in floor pens. Caged birds were heavier in body weight and laid heavier eggs with thicker shells than their counterparts in floor pens. The criteria employed in the measurement of interior egg quality showed no differences between the cage and pen environments, nor did there appear to be any differences in protein requirements between the two environments. more...
- Published
- 1959
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25. DISCUSSION. THE HOOGHLY FLOATING BRIDGE
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J Wood, Sir S Fleming, H Wakefield, H M Brunel, C Greaves, Bramwell, R Aitken, Benedict, E Matheson, Leslie, H N Maynard, G Turnbull, J Dixon, Sir G Campbell, A Macdougall, and W B Lewis
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Engineering ,business.industry ,General Medicine ,Pontoon bridge ,business ,Civil engineering - Published
- 1877
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26. THE PERFORMANCE OF LAYING HENS REARED ON RESTRICTED AND FULL FEEDING PROGRAMS
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J. R. Aitken and T. M. MacIntyre
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Animal science ,Food Animals ,Sexual maturity ,Animal Science and Zoology ,Biology ,Body weight ,Laying - Abstract
Experiments were conducted in 3 successive years to measure the effect on the performance of laying hens of restricting feed during the rearing period on range. About 1100 birds were reared and carried through a laying year in each experiment. Feed restriction was 72, 76 and 63 per cent of full feed for the test groups in Experiments 1, 2, and 3 respectively. All birds were full-fed in the laying house.Feed restriction changed the pattern of egg production, in that the restricted birds came into production later but subsequently laid at a higher rate than their full-fed counterparts. After 318 and 322 days in production the restricted birds in Experiments 1 and 2 respectively had overcome the disadvantage of a late start (7 and 14 days) and produced as many eggs as the full-fed birds. In Experiment 3, the restricted birds were held back 20 days, and after 315 days in production were still significantly behind in number of eggs produced.The restricted birds in the three experiments consumed an average of 0.17 pounds less feed per dozen eggs over the combined rearing and laying periods This amounts to a saving of 3 pounds of feed per bird, since the mean egg production of the restricted groups was 18 dozen eggs per bird.Early egg size was markedly increased by feed restriction and egg weights taken later in the year (after 3 months in production) remained slightly higher for the restricted groups. Albumin score for eggs from the restricted birds was better in all tests, but not significantly so in any given experiment. Specific gravity of the eggs was not influenced by feed restriction.Mortality on range and in the laying house was not affected by feed restriction on range. Body weight at housing time was much lower for the restricted birds but was not significantly lower at the end of the laying year. more...
- Published
- 1959
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27. Amino Acid Composition of Food Proteins: Inter- and Intralaboratory Variation
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B E McDonald, J R Aitken, J E Knipfel, B D Owen, and D C Hill
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Variation (linguistics) ,Amino acid composition ,Intralaboratory ,Chemistry ,General Chemistry ,Food science - Abstract
Inter- and intralaboratory variation in amino acid composition of casein, soy flour, and fish flour was examined for 5 cooperating laboratories, utilizing ion exchange chromatographic analyses for amino acids. Duplicate analyses within laboratories exhibited coefficients of variation of 3.7 to 4.4%. Hydrolysis was observed to affect amino acid recoveries to a significant degree, with some amino acids affected to greater extents than others. Laboratories utilizing Moore-Stein type analytical procedures did not appear to be more precise than those using the Piez-Morris method. Adjustment of data to constant total recovery values reduced interlaboratory variation considerably and suggested that recovery constants may be of value in comparing data from different laboratories. Results indicated that different laboratories employing varying analytical procedures may produce practically identical results from a standard sample, although variation may be observed due to characteristics of a specific system. Most variation in results was likely due to sample manipulations rather than to analysis per se. more...
- Published
- 1971
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28. The hydraulic characteristics of two-phase co-current flow through glass fibres
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A. R. Aitken and D. J. Gunn
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Mass flow meter ,Chemistry ,General Chemical Engineering ,Mass flow ,Isothermal flow ,Analytical chemistry ,Mechanics ,Slug flow ,Open-channel flow ,Condensed Matter::Soft Condensed Matter ,Physics::Fluid Dynamics ,Flow coefficient ,Wet gas ,Two-phase flow - Abstract
The mechanism of flow of air and water through packed glass fibres has been studied. Pressure drops and liquid hold ups were measured as a function of gas and liquid flow rates and the packing characteristics. It has been found that the pressure difference measured is dependent upon the history of previous gas and liquid flow rates in the bed. The liquid hold up is defined entirely by the gas and liquid flow rates. An analysis of the flow mechanism shows that the capillary forces interact with the fluid pressures in the bed. For example an increase in gas flow rate followed by a reduction to the same flow rate has been shown to reduce the resistance of the bed to gas flow even though the liquid flow rate is unchanged. A measure of the irreversibility of the flow operation is suggested. more...
- Published
- 1961
- Full Text
- View/download PDF
29. THE EFFECT OF FEEDING DIETS CONTAINING WHITE FISHMEAL ON ACCEPTABILITY AND FLAVOR INTENSITY OF ROASTED BROILER CHICKENS
- Author
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J. R. Aitken, Elizabeth Larmond, Paul Dean, and F. G. Proudfoot
- Subjects
Fish meal ,Food Animals ,White meat ,Animal production ,Flavour ,Broiler ,food and beverages ,Animal Science and Zoology ,Food science ,Biology ,equipment and supplies ,Flavor - Abstract
Diets containing 0, 3, 9, 14 and 19% white fishmeal and a diet containing 15% high-fat fishmeal were fed to the females of a commercial strain of broilers. Activated charcoal at the 0.5% level was added to the six finisher diets for one-half of the birds. The effect of starving birds for 24 and 72 hours after being fed the 19% fishmeal finisher diet was also evaluated; the starved birds were fed a ration containing 0% fishmeal from 63 to 72 days of age. The broilers were roasted without seasonings. A piece of dark meat and white meat with its skin from each of the diets was presented to 10 judges. This was repeated 10 times. Each judge was asked to state if the sample was acceptable or not, and to rate its flavor from no off-flavor to extreme fishy flavor. Tests were also run on cooking losses, color, moisture, texture and ether extract. Significant differences were found between the control (0% fishmeal) and the 15% high-fat and 19% fishmeal broilers for acceptability and flavor intensity. There were no significant differences found between birds fed charcoal and those not fed charcoal, nor were there any between the days of cooking for acceptability or flavor intensity. Cooking loss, color, percent fat, percent moisture and texture were not significantly affected by diets or charcoal. Starving the birds for 24 hours did not affect the acceptability or flavor intensity. Starving them for 72 hours did have a significant, favorable effect on the acceptability and flavor intensity. more...
- Published
- 1971
- Full Text
- View/download PDF
30. The Effect of Ammonium and Chloride Ions in the Diet of Hens on Egg Shell Quality
- Author
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J. R. Hunt and J. R. Aitken
- Subjects
Chemistry ,General Medicine ,Chloride ,chemistry.chemical_compound ,Bone ash ,Dietary treatment ,medicine ,Animal Science and Zoology ,Ammonium ,Composition (visual arts) ,Food science ,Eggshell ,Completely randomized design ,medicine.drug ,Specific gravity - Abstract
HALL and Helbacka (1959) demonstrated that feeding NH4C1 or HC1 to layers induced the production of thin shelled eggs. This laboratory obtained similar results with feeding NH4CI (Hunt and Aitken, 1961), and further noted an increase in bone ash. The experiment reported herein was designed to investigate the mode of action of NH4CI on shell formation, and to establish the dietary level of this salt necessary to induce a change in shell quality. PROCEDURE Two hundred and fifty pullets which had been in production for approximately two months and housed in individual cages were divided into 10 lots of 25 birds each in a completely randomized design. Each lot received the basal diet for a two-week period during which time pretest values were obtained for egg weight, specific gravity and albumen quality. A different dietary treatment was then fed to each lot. The basal diet (Table 1) was supplemented with … more...
- Published
- 1962
- Full Text
- View/download PDF
31. EXPERIMENTAL ERRORS IN EGG PRODUCTION EXPERIMENTS
- Author
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E. S. Merritt, Irene J. Stewart, and J. R. Aitken
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Efficiency ,Food Animals ,Basis (linear algebra) ,Design of experiments ,Coefficient of variation ,Statistics ,Randomized block design ,Production (economics) ,Animal Science and Zoology ,Sampling error ,Biology - Abstract
Data from 14 egg production experiments, which had replicated pens and individual trapnest records, were analysed to obtain estimates of experimental error from which to determine pen effects. The experiments were all nutrition experiments and were conducted at four experimental stations.Analyses were carried out on both a hen-housed and survivor basis. For all experiments the sampling error (individuals) underestimated the experimental error (individuals + pens) by about 20 per cent on a hen-housed basis. On a survivor basis there was no evidence of pen effects, that is, the sampling error did not underestimate the experimental error.The coefficient of variation for all experiments was 40 per cent on a hen-housed basis and 25 per cent on a survivor basis.The relative efficiency of two experimental designs, randomized block and completely randomized, was calculated for 11 of the experiments (on a hen-housed basis only). With the exception of 2 experiments, there was an increased efficiency of up to 500 per cent in utilizing a randomized block design. The data further indicate that the increase in efficiency obtained with a randomized block design is much more marked when the blocks represent different houses than when the blocks consist of different locations within a house. more...
- Published
- 1957
- Full Text
- View/download PDF
32. PERFORMANCE OF HEAVY-TYPE LAYERS ON A LOW ENERGY RATION
- Author
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E. S. Merritt, J. R. Aitken, L. Griesbach, and H. E. W. Meyer
- Subjects
Strain (chemistry) ,High mortality ,food and beverages ,Biology ,medicine.disease ,Body weight ,Obesity ,Low energy ,Animal science ,Medium energy ,Food Animals ,Energy density ,medicine ,Oat hulls ,Animal Science and Zoology ,Food science - Abstract
Three replicate trials were conducted to test the possibility that high mortality of non-specific origin being encountered in a genetic control strain of meat-type laying hens might be due to excessive energy intake. In each trial, the medium energy laying ration on which this strain of birds has been maintained for a number of years was compared with the same ration diluted with 20 per cent pulverized oat hulls, for a period in excess of 330 days.Mortality was not influenced by the energy content of the ration, nor was rate of egg production. The low energy ration reduced final body weight by only 0.1 to 0.2 pounds, suggesting that the birds on the control diet were not unduly fat. Comparison of these results with others reported in the literature leads to the speculation that mortality due to obesity may be a problem only in heavier and faster-growing strains than the strain used in this study. more...
- Published
- 1963
- Full Text
- View/download PDF
33. The Influence of Method of Crumbling Diets Containing Different Levels of Protein and Lysine on Chick Performance
- Author
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J. B. O’Neil, J. R. Aitken, A. R. Robblee, J. Biely, H. S. Bayley, S. J. Slinger, J. L. Sell, and D. R. Clandinin
- Subjects
Protein content ,Bran ,digestive, oral, and skin physiology ,Physical form ,Lysine ,Pellet ,food and beverages ,Animal Science and Zoology ,General Medicine ,Food science ,Biology ,humanities - Abstract
IT IS standard practice to pellet and crumble chick diets before feeding. Such processing alters not only the physical form of the feed but often alters the performance of the birds receiving the processed feeds. The nature and extent of these changes depend on the type of feed and on the processing conditions used. Bearse et al. (1952) found that pelleting improved the nutritional value of feeds, particularly those with a high fibre level. Cave et al. (1965) found that the performance of chicks receiving a diet containing wheat bran was increased when the diets were pelleted. However, Jensen et al. (1965) found different effects of pelleting turkey grower rations depending on the protein content of the feed. Steam pelleting improved the performance on a diet with adequate protein levels but for diets with only marginal protein or lysine levels steam pelleting reduced performance. They suggested that pelleting had increased . . . more...
- Published
- 1968
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34. The Effect of High Levels of Dietary Energy and Protein on the Performance of Laying Hens
- Author
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J. R. Aitken and T. M. MacIntyre
- Subjects
High energy ,Animal science ,Fish meal ,Calorie ,Energy density ,Animal Science and Zoology ,Composition (visual arts) ,General Medicine ,Food science ,Biology ,Feed conversion ratio ,Laying ,Dozen - Abstract
IN RECENT years the use of high energy rations for laying hens has become increasingly popular. The advantages claimed for such rations are a reduction in the amount of feed consumed per dozen eggs and an increase in egg production. The improvement in feed efficiency on high energy diets is now well established, but the evidence for an increase in the rate of egg production is not nearly as conclusive. Hill et al. (1956) found that rate of egg production was influenced by the energy content of the diet (740–1025 Calories per pound) only during the cold winter months, but not at other times of the year. Gerry (1954) reported that high energy laying rations had no appreciable effect on rate of egg production. On the other hand Singsen et al. (1952) and Skinner et al. (1951) reported higher egg production on high energy diets than on the standard . . . more...
- Published
- 1957
- Full Text
- View/download PDF
35. Influence of Environment on the Response of Chicks to Growth Stimulants
- Author
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A. B. Morrison, W. G. Hunsaker, and J. R. Aitken
- Subjects
animal structures ,Arsanilic acid ,medicine.drug_class ,media_common.quotation_subject ,Antibiotics ,Appetite ,General Medicine ,Biology ,Penicillin ,Procaine ,chemistry.chemical_compound ,Animal science ,chemistry ,medicine ,Animal Science and Zoology ,Food science ,media_common ,medicine.drug ,Beta lactam antibiotics - Abstract
RECENTLY, several reports have appeared indicating the important influence of environment on the growth response of chicks to antibiotics (Coates et al., 1951, 1952; Bird et al., 1952; Hill et al., 1952, 1953; Lillie et al., 1953). In the experiment reported herein, the work was extended to include studies on the influence of environment on the response of chicks to other growth stimulants in addition to an antibiotic. EXPERIMENTAL Four growth stimulants, procaine penicillin, 3-nitro-4-hydroxyphenylarsonic acid, arsanilic acid, and ethomid C/15, were tested on day-old N.H.×B.P.R. chicks in both an old and a new environment. The new environment consisted of a building, which, although it had housed chicks in previous years, had been empty for approximately six months. In addition, the interior of the building had been painted, and the floor disinfected four times two months before the experiment was started. The chicks were brooded in new starting batteries with … more...
- Published
- 1954
- Full Text
- View/download PDF
36. DISCUSSION. ON THE PRACTICE AND RESULTS OF IRRIGATION IN NORTHERN INDIA
- Author
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Hawksley, Brunlees, Barlow, W H Greathed, W Shelford, J G C C Godsman, B Latham, J F Bateman, Parkes, Smith, R Aitken, Medley, C B Vignoles, and G B Bruce
- Subjects
Irrigation ,business.industry ,Agriculture ,Water supply ,Environmental science ,Sewage ,General Medicine ,business ,Water resource management - Published
- 1872
- Full Text
- View/download PDF
37. THE NUTRITIVE VALUE OF CANADIAN MEAT MEALS FOR CHICKS
- Author
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D. C. Hill, J. T. Sell, J. Biely, J. R. Aitken, and A. R. Robblee
- Subjects
Meal ,Protein–energy malnutrition ,digestive, oral, and skin physiology ,Soybean meal ,Broiler ,food and beverages ,Biology ,medicine.disease ,Fish meal ,Starter ,Food Animals ,medicine ,Animal Science and Zoology ,Food science - Abstract
Chick growth trials were conducted by five cooperating laboratories on five meat meals obtained from widely separated sources across Canada. The meat meals were tested by feeding them individually at a level of 12% in a broiler starter diet. There were three battery brooder pens of 15 male chicks each per ration at each of five locations, in two successive trials.Mean body weights at 4 weeks of age over all locations combined were in all cases lower on the meat meal diets than on a control diet containing no meat meal but using soybean meal as a primary source of protein. Growth on the meat meal diets ranged from 88% to 96% of that on the control diet in trial 1, and from 92% to 98% in trial 2. At the individual locations, there were 5 instances out of 50 in which growth on a meat meal diet exceeded that on a control diet. more...
- Published
- 1966
- Full Text
- View/download PDF
38. Performance of Laying Hens Subjected to Restricted Feeding During Rearing and Laying Periods
- Author
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E. D. Walter and J. R. Aitken
- Subjects
Animal science ,Feed consumption ,media_common.quotation_subject ,Sexual maturity ,Animal Science and Zoology ,Appetite ,General Medicine ,Nutrient intake ,Biology ,Body weight ,Laying ,media_common - Abstract
IN RECENT years there has been considerable controversy concerning the merits of rearing replacement stock pullets on a low plane of nutrition. Research reports practically all indicate a delay in sexual maturity when nutrient intake is limited but there is much less agreement as to the effect on subsequent laying-house performance. This can be attributed, at least in part, to different methods and severity of restriction and also to variations in length of restriction periods. Tests concerned with an actual restriction in feed intake were reported by Milby and Sherwood (1953), Singsen et al. (1954), and Milby and Sherwood (1956). Other than delaying sexual maturity from 10 to 26 days, restricted feeding had no real influence on subsequent egg production, mortality, over-all feed consumption, final body weight or average egg weight. Similar results were obtained by Sunde et al. (1954), when comparing a complete growing diet with a diet containing … more...
- Published
- 1961
- Full Text
- View/download PDF
39. Anaesthesia for intracranial aneurysms with hypotension and spontaneous respiration
- Author
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C. G. Drake, R. R. Aitken, and Gordon R. Sellery
- Subjects
Adult ,Male ,medicine.medical_specialty ,Brachial Artery ,Intracranial Pressure ,Pain medicine ,Blood Pressure ,Arterial spasm ,Anesthesiology ,Internal medicine ,Respiration ,Methods ,Humans ,Medicine ,Anesthesia ,Spontaneous respiration ,Cerebral perfusion pressure ,business.industry ,fungi ,food and beverages ,Intracranial Aneurysm ,Arteries ,General Medicine ,Carbon Dioxide ,Hydrogen-Ion Concentration ,Oxygen ,Radiography ,Anesthesiology and Pain Medicine ,Cerebral blood flow ,Basilar Artery ,Cardiology ,business ,Perfusion - Abstract
In the surgical treatment of cerebral aneurysms spontaneous respiration is advantageous, especially during hypotension, if the blood gases can be maintained near normal. Hypocarbia is prevented, to avoid its possibly harmful effects on cerebral blood flow and its contribution to postoperative arterial spasm. The pattern of respiration can be utilized as a useful monitor of the perfusion of vital centres. more...
- Published
- 1973
- Full Text
- View/download PDF
40. DISCUSSION ON THE GEOLOGICAL CONDITIONS AFFECTING THE CONSTRUCTION OF A TUNNEL BETWEEN ENGLAND AND FRANCE
- Author
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W Smyth, Prestwich, Homersham, F W Sheilds, H Willett, Bazalgette, J Evans, Tyler, E Low, Bateman, R Aitken, Rawlinson, Sir J Hawkshaw, E Hull, Ramsay, and W Topley
- Subjects
Mining engineering ,business.industry ,Greensand ,Submarine ,Channel tunnel ,Coal ,Geotechnical engineering ,business ,Geology - Published
- 1873
- Full Text
- View/download PDF
41. Influence of Dietary Tallow on the Utilization of Calcium by the Laying Hen
- Author
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W. G. Hunsaker, J. R. Aitken, and J. R. Hunt
- Subjects
Chemistry ,Tallow ,Pepper ,chemistry.chemical_element ,Animal Science and Zoology ,Composition (visual arts) ,Yellow grease ,General Medicine ,Food science ,Calcium ,Eggshell ,Laying ,Dietary fat - Abstract
THE use of tallow in laying rations has prompted some concern over its possible effect on calcium utilization, as reflected in egg shell quality. The possibility that fat in the feed ma y adversely affect calcium utilization is suggested by the results of published experiments with laying hens, chicks and rats. Hochreich et al. (1958) observed a decrease in shell thickness when 6.6% yellow grease was incorporated in a laying ration fed to hens receiving oyster shell ad libitum. Using chicks, Pepper et al. (1955) and Edwards el al. (1958) demonstrate d an increase in calcium requirement when fat was incorporated in the diet. There are also reports that calcium utilization in rats decreases with increasing levels of dietary fat (French, 1942; and French and Elliot, 1943). On the other hand, Boyd et al. (1932) noted that dietary fats increased calcium utilization in rats through its acidifying effect on the… more...
- Published
- 1961
- Full Text
- View/download PDF
42. Effect of Intake and Source of Protein on Laying Performance of Seven Strains under Single and Double Cage Housing
- Author
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R. S. Gowe, G. E. Dickerson, and J. R. Aitken
- Subjects
Animal science ,Nutrient ,Dietary protein ,Feed consumption ,Albumin ,Animal Science and Zoology ,General Medicine ,Biology ,Body weight ,Cage ,Feed conversion ratio ,Specific gravity - Abstract
An experiment was conducted to compare the laying house performance of 7 strains of White Leghorns, housed at two different densities (1 and 2 birds per 8″ × 16″ cage) when fed 7 diets differing in protein and energy levels. The test started with 2366 pullets, and lasted for 336 days. Performance criteria were egg production, egg weight, body weight, feed consumption, mortality and egg quality. There were large real differences among strains in all performance traits. Compared to birds housed 1 per cage, those housed 2 in a cage laid 9% fewer eggs per hen housed, suffered 1.5 times as much mortality, gained 130 g. less weight from 20 to 64 weeks of age, consumed 3% more feed and required 8% more feed per unit weight of eggs produced, but eggs did not differ in size, specific gravity, albumin quality, shell shape or blood spots. Shells were slightly whiter at 225 days of age and rougher at 450 days of age in the 2 bird cages. Protein intake was the dietary factor most closely associated with large effects of diet on gains in body weight, egg production, egg size, feed conversion and albumin height. Average daily crude protein intake of 17 g. for the laying year appeared adequate and there were no significant strain differences in dietary effects. Strains differed markedly in voluntary nutrient intakes but not in sensitivity to the range of dietary protein and energy levels investigated. Housing birds at 2 versus 1 bird per cage reduced egg production and feed conversion significantly more at lower protein intake levels; its effects also differed appreciably among genetic stocks for feed consumption, egg weight and body weight but not for net efficiency of feed conversion. more...
- Published
- 1973
- Full Text
- View/download PDF
43. CORRESPONDENCE. AMSTERDAM SHIP CANAL
- Author
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W J Doherty, G H Phipps, P J Messent, L F V Harcourt, H Hayter, I Bell, R Aitken, and W D Cay
- Subjects
Dredging ,Engineering ,symbols.namesake ,business.industry ,Breakwater ,symbols ,business ,Titan (rocket family) ,Cofferdam ,Civil engineering - Abstract
n/a
- Published
- 1879
- Full Text
- View/download PDF
44. Genotype × Dietary Protein Level Interactions in Egg Production Stocks
- Author
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J. R. Aitken, J. D. Summers, N. Nikolaiczuk, W. K. Barr, A. R. Robblee, and J. Biely
- Subjects
Animal science ,Dietary protein ,Feed consumption ,Low-protein diet ,medicine.medical_treatment ,embryonic structures ,Genotype ,medicine ,Albumin ,Animal Science and Zoology ,General Medicine ,Biology ,Body weight - Abstract
Two diets, one adequate in protein (17.0%) and one marginal (14.5%), were fed to the 17 egg production strains entered in the Canadian Random Sample Test. The purpose was to test for the presence of genotype × dietary protein level interactions, using egg production, egg weight, final body weight, feed consumption, mortality and egg quality as performance criteria. There were two floor pens totalling approximately 120 birds per strain on each diet. Duration of the test was 350 days. The low protein diet resulted in lower egg production, mean egg weight, final body weight and albumin quality. Significant genotype × dietary protein level interactions were observed for egg weight, albumin quality and feed consumption. The significance of these findings is discussed. more...
- Published
- 1972
- Full Text
- View/download PDF
45. A Feeding Trial Conducted at Six Different Locations
- Author
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J. B. O’Neill, J. T. Sell, J. R. Aitken, D. C. Hill, J. Biely, and A. R. Robblee
- Subjects
business.industry ,Statistics ,food and beverages ,Animal Science and Zoology ,General Medicine ,Biology ,business ,Breed ,Test (assessment) ,Biotechnology - Abstract
OVER the past two decades, the random sample test has become a widely used tool in assessing the relative merits of commercial breeds and strains of poultry. For a number of reasons, random sample tests of commercial poultry rations have not been organized on an extensive scale, but comparisons of commercial rations are nevertheless made locally by a variety of organizations and individuals. Poultry rations are continually being compared by numerous research institutions, and results of these feeding trials, frequently conducted with a single breed or strain in a single environment, are used to recommend one formula over another for general use under a wide variety of conditions. In accepting such recommendations, we must assume that the order in which the rations rank under the test conditions can be used to predict the relative levels of performance when they are fed to other strains of birds in other environments, i.e… more...
- Published
- 1964
- Full Text
- View/download PDF
46. Phosphorus Requirements of Laying Hens Confined to Cages
- Author
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J. R. Aitken and E. D. Walter
- Subjects
Animal science ,chemistry ,Phosphorus ,chemistry.chemical_element ,Animal Science and Zoology ,Composition (visual arts) ,General Medicine ,Calcium ,Body weight ,Laying - Abstract
INTRODUCTION INFORMATION on the phosphorus requirements of laying hens is limited and there is a lack of unanimity in the results reported by various investigators. Norris et al. (1934) reported that the 0.75 percent level of phosphorus was adequate for normal egg production but found that a 0.5 percent level was inadequate. Miller and Bearse (1934) found that 0.80 percent phosphorus was required for optimum production when the calcium level in the ration was 2.23 or 3.00 percent. The need for additional phosphorus as the calcium level of a ration is increased was suggested by the results of Evans and Carver (1942) who observed that 0.6 percent phosphorus was adequate in laying rations containing 1.5 percent calcium but 0.8 percent phosphorus was necessary in rations containing 2.5 percent calcium. Further, when 3.0 percent calcium was included in the diet, 1.0 percent phosphorus was more satisfactory than 0.8 percent. In more … more...
- Published
- 1962
- Full Text
- View/download PDF
47. THE SEWAGE QUESTION. (CONTRIBUTIONS RECEIVED BY THE SECRETARY, i.e. CORRESPONDENCE)
- Author
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L Flower, C N Bazalgette, J Mansergh, J Newton, J Hassard, W Atkinson, H Tanner, H Robinson, W Donaldson, R Aitken, R W P Birch, J B Alliott, Eachus, B S Brundell, Voelcker, M Millie, J Wrightson, R Jacob, T W Keates, J C Melliss, and C F Gower more...
- Subjects
business.industry ,Law ,Sewage ,Environmental science ,Sanitary sewer ,business ,Water resource management - Published
- 1876
- Full Text
- View/download PDF
48. Hydrogenation of a coker distillate derived from Athabasca bitumen
- Author
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A. R. Aitken, W. H. Merrill, and M. P. Pleet
- Subjects
Coker unit ,Fixed bed ,General Chemical Engineering ,Analytical chemistry ,Mineralogy ,chemistry.chemical_element ,law.invention ,Catalysis ,chemistry ,law ,Asphalt ,Distillation ,Cobalt ,Specific gravity ,Space velocity - Abstract
A coker distillate of Athabasca bitumen was hydrogenated over a fixed bed of cobalt molybdate on alumina catalyst. The effect of reaction pressure on the rate of catalyst deactivation was investigated at 896°F., an hourly space velocity of 2.0 and pressures from 1,000 to 3,000 p.s.i. The following expression was derived from the results of these experiments which relates reaction pressures and the hourly increase of the oil product specific gravity at these conditions. The yield and quality of the hydrogenated oil products and the relative hydrogen consumptions were determined at the following operating conditions: 1. Pressure—1,000–10,000 p.s.i.; Temperature—797–896°F. Space velocity—2.0 hr.−1. 2. Pressure—3,000 p.s.i.; Temperature—797–896°F. Space velocity—1.0–4.0 hr.−1. On a hydrogene le distillat provenant de la cokefaction du bitume d'Athabasca au moyen d'un lit fixe de molybdate de cobalt sur L'alumine. L'influence de la pression entre 1000 et 3000 psi sur le taux de desactivation du catalyseur a ete etudiee pour une temperature de 896°F. et une vitesse volumetrique horaire de 2 volumes de distillat par unite de volume de reacteur par heure. A L'aide des valeurs experimentales obtenues on derive une correlation entre la pression de reaction et L'augmentation horaire de la densite du produit. Le rendement et la qualite des produits hydrogenes ainsi qui la consommation d'hydrogene ont determines aux conditions suivantes: 1. Pression—1,000–10,000 psi; Temperature—797–896°F.; Vitesse volumetrique—2.0 hr−1. 2. Pression—3,000 psi; Temperature—797–896°F; Vitesse volumetrique—1.0–4.0 hr−2. more...
- Published
- 1964
- Full Text
- View/download PDF
49. DISCUSSION. SPEED ON CANALS. (INCLUDES WOODCUTS)
- Author
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A Grothe, J R Ravenhill, F R Conder, J H Taunton, J E Williams, E J Lloyd, H J Marten, R Aitken, J I Thornycroft, Sir Jw Bazalgette, Sir C Hartley, R Gordon, H Maudslay, Sir R Rawlinson, W Stroudley, L F V Harcourt, A Giles, J H Latham, J D A Samuda, W Shelford, P Williams, and J B Redman more...
- Subjects
Engineering drawing ,Geography ,Suez canal ,Marine engineering - Published
- 1884
- Full Text
- View/download PDF
50. The Fertilizing Capacity of Fowl Semen as Affected by Time and Temperature of Storage
- Author
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G. S. Lindblad, J. R. Aitken, and W. G. Hunsaker
- Subjects
endocrine system ,animal structures ,urogenital system ,Fowl ,Semen ,General Medicine ,Biology ,urologic and male genital diseases ,biology.organism_classification ,Freezing point ,fluids and secretions ,Animal science ,Human fertilization ,Animal Science and Zoology - Abstract
A CONSIDERABLE amount of research has been done on the problem of storage of fowl semen at very low temperatures. While the results have not been entirely successful, some fertility has been reported (Shaffner, 1942), and chicks have been hatched (Smith and Polge, 1950) after fertilization with semen held at −70°C. Chicks have also been hatched from eggs fertilized with semen that had been frozen at −6°C. for 30 seconds and then thawed (Shaffner et al., 1941). On the other hand, only a limited number of studies have been reported on the fertilizing capacity of semen held at temperatures above the freezing point. These reports indicated the least decline in fertilizing power to occur when the semen was held at 10° to 20°C. (Burrows and Quinn, 1939; Warren and Gish, 1943; Garren and Shaffner, 1952). Holding the semen at or near 0°C. or at a temperature of 30°C. or above, resulted … more...
- Published
- 1956
- Full Text
- View/download PDF
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