| |
Records |
Links |
|
Author |
Jonsson, H.; Egenvall, A. |
|
| |
Title |
Prevalence of gastric ulceration in Swedish Standardbreds in race training |
Type |
Journal Article |
| |
Year |
2006 |
Publication |
Equine Veterinary Journal |
Abbreviated Journal |
Equine Vet J |
|
| |
Volume |
38 |
Issue |
3 |
Pages |
209-213 |
|
| |
Keywords |
Age Factors; Animal Feed; Animals; Cross-Sectional Studies; Female; Gastric Mucosa/pathology; Gastroscopy/methods/veterinary; Horse Diseases/*epidemiology/etiology/pathology; Horses; Male; Physical Conditioning, Animal/*adverse effects; Prevalence; Questionnaires; Severity of Illness Index; Sex Factors; Sports; Stomach Ulcer/epidemiology/etiology/pathology/*veterinary; Sweden/epidemiology |
|
| |
Abstract |
REASONS FOR PERFORMING STUDY: There is little information about the prevalence of gastric ulcers in Standardbred trotters and potential correlations between ulcers and various traits, e.g. age, sex, performance, temperament and feeding regimens, need further elucidation. OBJECTIVES: The prevalence of ulcers in the gastric squamous mucosa of Swedish Standardbreds was estimated and the associations between ulcer score and age, sex, performance, temperament and feeding regimens were determined. METHODS: Eighty Swedish Standardbreds in active race training, trained by 9 different trainers, underwent gastroscopy. Information on age, gender, status of training, performance over the last 4 months compared with the trainer's expectations before that period, behaviour, eating habits, feed type, bedding type, time spent outdoors per day and medical treatment during the last month was collected. Gastroscopy was performed and lesions in the squamous gastric mucosa were scored from 0 to 4 (0 = no lesions; 4 = > 5 lesions with haemorrhage, > 10 lesions with no haemorrhage, or a large area of diffuse loss of surface epithelium). RESULTS: Twenty-four (30%) of the horses had no lesions in the squamous mucosa, 22 (27.5%) had a score of 1; 21 (26.2%) score 2; 9 (11.2%) score 3; and 4 (5%) score 4. Horses that were in preparatory training and those that had raced during the last month were significantly more affected than horses that were fit for racing but had not raced during the last month, using a logistic regression model with trainer incorporated as a random effect. CONCLUSIONS: The study confirmed a high prevalence of ulcers in the gastric squamous mucosa of Standardbreds in race training. Of the studied parameters only status of training showed a significant association with gastric ulcers of the squamous mucosa. POTENTIAL RELEVANCE: Gastric ulceration is a common disease and diagnosis should be made by endoscopic examination of the gastric mucosa, since parameters such as age, gender, performance, behaviour, eating habits provide only weak clues as to which horses might be affected. Further studies are needed to determine the aetiology of the syndrome and to find ways to reduce, if possible, the frequency of gastric ulcers. |
|
| |
Address |
ATG:s Hastsjukhus Farjestad, Norra Infarten 82, SE-654 65 Karlstad, Sweden |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN  |
0425-1644 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
PMID:16706273 |
Approved |
no |
|
| |
Call Number |
|
Serial |
1870 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Robertson, S. |
|
| |
Title |
The importance of assessing pain in horses and donkeys |
Type |
Journal Article |
| |
Year |
2006 |
Publication |
Equine Veterinary Journal |
Abbreviated Journal |
Equine Vet J |
|
| |
Volume |
38 |
Issue |
1 |
Pages |
5-6 |
|
| |
Keywords |
Animals; *Behavior, Animal/physiology; Equidae/*physiology; Horses/physiology; Pain/diagnosis/prevention & control/*veterinary; Pain Measurement/methods/*veterinary; Veterinary Medicine/*methods |
|
| |
Abstract |
|
|
| |
Address |
Section of Anaesthesia and Pain Management, College of Veterinary of Medicine, University of Florida, Gainesville 32610-0136, USA |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0425-1644 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
PMID:16411578 |
Approved |
no |
|
| |
Call Number |
|
Serial |
1881 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Boden, L.A.; Anderson, G.A.; Charles, J.A.; Morgan, K.L.; Morton, J.M.; Parkin, T.D.H.; Slocombe, R.F.; Clarke, A.F. |
|
| |
Title |
Risk of fatality and causes of death of Thoroughbred horses associated with racing in Victoria, Australia: 1989-2004 |
Type |
Journal Article |
| |
Year |
2006 |
Publication |
Equine Veterinary Journal |
Abbreviated Journal |
Equine Vet J |
|
| |
Volume |
38 |
Issue |
4 |
Pages |
312-318 |
|
| |
Keywords |
Animals; Athletic Injuries/epidemiology/mortality/*veterinary; *Cause of Death; Female; *Floors and Floorcoverings; Horses/*injuries; Male; Physical Conditioning, Animal/*adverse effects; Risk Factors; Running/injuries; Safety; Sports; Victoria |
|
| |
Abstract |
REASONS FOR PERFORMING STUDY: Determining the risk of fatality of Thoroughbred horses while racing is essential to assess the impact of intervention measures designed to minimise such fatalities. OBJECTIVES: To measure the risk of racehorse fatality in jump and flat starts on racecourses in Victoria, Australia, over a 15 year period and to determine proportional mortality rates for specific causes of death. METHODS: All fatalities of Thoroughbred horses that occurred during or within 24 h of a race were identified from a database. The risk of a start resulting in a racehorse fatality in all races and within flat and jump races, proportional mortality rates, population attributable risk, population attributable fraction and risk ratios were calculated along with 95% confidence intervals. Poisson regression was also performed to estimate risk ratios. RESULTS: There were 514 fatalities over the 15 year period; 316 in flat races and 198 in jump races. The risk of fatality was 0.44 per 1000 flat starts and 8.3 per 1000 jump starts (18.9 x greater). The risk of fatality on city tracks was 1.1 per 1000 starts whereas on country tracks it was 0.57 per 1000 starts. Of the 316 fatalities in flat races, 73.4% were due to limb injury, 2.5% to cranial or vertebral injury and 19.0% were sudden deaths. Of the 198 fatalities in jump races, 68.7% were due to limb injury, 16.2% to cranial or vertebral injury and 3.5% were sudden deaths. The risk of fatality in flat starts increased between 1989 and 2004 but the risk in jump starts remained unchanged over the 15 year period. CONCLUSIONS: The risk of fatality in flat starts was lower in Victoria than North America and the UK but the risk in jump starts was greater. Catastrophic limb injury was the major reason for racehorse fatality in Victoria but there was a larger percentage of sudden deaths than has been reported overseas. The risk of fatality in jump starts remained constant over the study period despite jump racing reviews that recommended changes to hurdle and steeple races to improve safety. POTENTIAL RELEVANCE: This study provides important benchmarks for the racing industry to monitor racetrack fatalities and evaluate intervention strategies. |
|
| |
Address |
Department of Veterinary Science, The University of Melbourne, Werribee, Victoria, Australia |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0425-1644 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
PMID:16866197 |
Approved |
no |
|
| |
Call Number |
Equine Behaviour @ team @ |
Serial |
3761 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Murray, J.K.; Singer, E.R.; Morgan, K.L.; Proudman, C.J.; French, N.P. |
|
| |
Title |
The risk of a horse-and-rider partnership falling on the cross-country phase of eventing competitions |
Type |
Journal Article |
| |
Year |
2006 |
Publication |
Equine Veterinary Journal |
Abbreviated Journal |
Equine Vet J |
|
| |
Volume |
38 |
Issue |
2 |
Pages |
158-163 |
|
| |
Keywords |
*Accidental Falls; Animals; Athletic Injuries/epidemiology/*veterinary; Case-Control Studies; Horses/*injuries; Humans; Logistic Models; Physical Conditioning, Animal; Prospective Studies; Risk Factors; Safety; Sports; Time Factors |
|
| |
Abstract |
REASONS FOR PERFORMING STUDY: Fatalities resulting from horse falls occurring during the cross-country phase of eventing competitions initiated epidemiological investigation of the risk factors associated with horse falls. OBJECTIVES: To identify variables that increased or decreased the risk of a horse fall during the cross-country phase of an eventing competition. METHODS: Data were collected from randomly selected British Eventing competitions held in Great Britain during 2001 and 2002. Data were obtained for 173 cases (jumping efforts resulting in a fall of the horse-and-rider partnership) and 503 matched controls (jumping efforts not resulting in a fall). The risk of falling was modelled using conditional logistic regression. RESULTS: An increased risk of a horse fall was associated with jumping into or out of water; taking off from good-to-soft, soft or heavy ground; fences with a drop landing; nonangled fences with a spread > or =2 m; and angled fences. Other risk factors included riders who knew that they were in the lead within the competition before the cross-country phase; an inappropriate speed of approach to the fence (too fast or too slow); horse-and-rider partnerships that had not incurred refusals at earlier fences; and riders who received cross-country tuition. CONCLUSIONS: This study has identified modifiable course- and fence-level risk factors for horse falls during the cross-country phase of eventing competitions. The risk of horse and rider injury at eventing competitions should be reduced by 3 simple measures; maintaining good to firm take-off surfaces at fences, reducing the base spread of fences to <2 m and reducing the use of fences at which horses are required to jump into or out of water. Risk reduction arising from course and fence modification needs to be confirmed by intervention studies. Potential relevance: Knowledge of factors that increase or decrease the risk of a horse fall can be used by UK governing bodies of the sport to reduce the risk of horse falls on the cross-country phase of eventing competitions, and reduce the risk of horse and rider injuries and fatalities. As one in 3 horses that fall injure themselves and one in 100 horse falls results in fatality to the horse, we suggest that immediate consideration is given to these recommendations. |
|
| |
Address |
Epidemiology Group, Faculty of Veterinary Science, University of Liverpool, Leahurst, Chester High Road, Neston, South Wirral CH64 7TE, UK |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0425-1644 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
PMID:16536386 |
Approved |
no |
|
| |
Call Number |
Equine Behaviour @ team @ |
Serial |
3765 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Parsons, K.J.; Wilson, A.M. |
|
| |
Title |
The use of MP3 recorders to log data from equine hoof mounted accelerometers |
Type |
Journal Article |
| |
Year |
2006 |
Publication |
Equine Veterinary Journal |
Abbreviated Journal |
Equine Vet J |
|
| |
Volume |
38 |
Issue |
7 |
Pages |
675-680 |
|
| |
Keywords |
Acceleration; Animals; Equipment and Supplies/standards/*veterinary; Hoof and Claw/*physiology; Horses/*physiology; Locomotion/*physiology; Physical Conditioning, Animal/*physiology; Reproducibility of Results; Running/physiology; Sensitivity and Specificity |
|
| |
Abstract |
REASONS FOR PERFORMING STUDy: MP3 recorders are readily available, small, lightweight and low cost, providing the potential for logging analogue hoof mounted accelerometer signals for the characterisation of equine locomotion. These, however, require testing in practice. OBJECTIVES: To test whether 1) multiple MP3 recorders can maintain synchronisation, giving the ability to synchronise independent recorders for the logging of multiple limbs simultaneously; and 2) features of a foot mounted accelerometer signal attributable to foot-on and foot-off can be accurately identified from horse foot mounted accelerometers logged directly into an MP3 recorder. METHODS: Three experiments were performed: 1) Maintenance of synchronisation was assessed by counting the number of samples recorded by each of 4 MP3 recorders while mounted on a trotting horse and over 2 consecutive 30 min periods in 8 recorders on a bench. 2) Foot-on and foot-off times obtained from manual transcription of MP3 logged data and directly logged accelerometer signal were compared. 3) MP3/accelerometer acquisition units were used to log accelerometer signals from racehorses during extended training sessions. RESULTS: Mean absolute error of synchronisation between MP3 recorders was 10 samples per million (compared to mean number of samples, range 1-32 samples per million). Error accumulation showed a linear correlation with time. Features attributable to foot on and foot off were equally identifiable from the MP3 recorded signal over a range of equine gaits. CONCLUSIONS: Multiple MP3 recorders can be synchronised and used as a relatively cheap, robust, reliable and accurate logging system when combined with an accelerometer and external battery for the specific application of the measurement of stride timing variables across the range of equine gaits during field locomotion. POTENTIAL RELEVANCE: Footfall timings can be used to identify intervals between the fore and hind contacts, the identification of diagonal advanced placement and to calculate stride timing variables (stance time, protraction time and stride time). These parameters are invaluable for the characterisation and assessment of equine locomotion. |
|
| |
Address |
Structure and Motion Laboratory, The Royal Veterinary College, North Mymms, Hatfield, Hertfordshire AL9 7TA, UK |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0425-1644 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
PMID:17228585 |
Approved |
no |
|
| |
Call Number |
Equine Behaviour @ team @ |
Serial |
4022 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Ryan, C.T.; Schaer, B.L.D.; Nunamaker, D.M. |
|
| |
Title |
A novel wireless data acquisition system for the measurement of hoof accelerations in the exercising horse |
Type |
Journal Article |
| |
Year |
2006 |
Publication |
Equine Veterinary Journal |
Abbreviated Journal |
Equine Vet J |
|
| |
Volume |
38 |
Issue |
7 |
Pages |
671-674 |
|
| |
Keywords |
*Acceleration; Animals; Biomechanics; Equipment and Supplies/*veterinary; Hoof and Claw/*physiology; Horses/*physiology; Kinetics; Musculoskeletal Physiology; Physical Conditioning, Animal/*physiology; Running/physiology |
|
| |
Abstract |
REASONS FOR PERFORMING STUDY: A device is needed to safely and wirelessly evaluate accelerations experienced by the horse hoof under a variety of surface conditions with the horse exercising at training or racing speeds. OBJECTIVES: To develop a miniaturised wireless data acquisition system (WDAS) which reliably records hoof accelerations and the times over which they occur in a minimally invasive manner in the exercising Thoroughbred. METHODS: The following criteria were set for device development: production of a lightweight and minimally invasive system, which provides an adequate acceleration range, appropriate frequency response to capture high speed events, and compatibility with a low power wireless telemetry system. Following device development, the WDAS was calibrated, and tested in 6 Thoroughbred horses over a variety of surfaces. RESULTS: Collection of acceleration in seven trials using 6 horses over a variety of surfaces resulted in repeatable acceleration data with respect to the overall characteristic shape of the impact profile. Impact accelerations varied with surface, ranging 34.8-191.7 g. Accelerations on take off were in a similar range, although higher in some trials. Peak impact accelerations tended to larger over the grass paddock surface, than either the indoor arena or the dirt track. During dirt track trials, accelerations on take-off were often comparably larger than those observed on impact within the same footfall. CONCLUSIONS: This study reports the development of a wireless system that successfully measures hoof acceleration in a minimally invasive manner over a variety of surface and exercise conditions. POTENTIAL RELEVANCE: The WDAS will be used in further studies to evaluate various components of the horse-racetrack interface, in an attempt to identify risk factors for musculoskeletal injury in the Thoroughbred racehorse. |
|
| |
Address |
Richard S. Reynolds, Jr. Comparative Orthopedic Research Laboratory, Department of Clinical Studies, New Bolton Center, School of Veterinary Medicine, University of Pennsylvania, Kennett Square, Pennsylvania 19348, USA |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0425-1644 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
PMID:17228584 |
Approved |
no |
|
| |
Call Number |
Equine Behaviour @ team @ |
Serial |
4023 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Schaer, B.L.D.; Ryan, C.T.; Boston, R.C.; Nunamaker, D.M. |
|
| |
Title |
The horse-racetrack interface: a preliminary study on the effect of shoeing on impact trauma using a novel wireless data acquisition system |
Type |
Journal Article |
| |
Year |
2006 |
Publication |
Equine Veterinary Journal |
Abbreviated Journal |
Equine Vet J |
|
| |
Volume |
38 |
Issue |
7 |
Pages |
664-670 |
|
| |
Keywords |
Animals; Equipment and Supplies/veterinary; Forelimb/injuries/physiology; Hindlimb/injuries/physiology; Hoof and Claw/*physiology; Horses/*injuries/*physiology; Locomotion/physiology; Muscle, Skeletal/injuries/*physiology; *Musculoskeletal Physiology; Musculoskeletal System/*injuries; Physical Conditioning, Animal/*physiology; Risk Factors; Running/physiology; Shoes |
|
| |
Abstract |
REASONS FOR PERFORMING STUDY: There is a need to determine accelerations acting on the equine hoof under field conditions in order to better assess the risks for orthopaedic health associated with shoeing practices and/or surface conditions. OBJECTIVES: To measure the acceleration profiles generated in Thoroughbred racehorses exercising at high speeds over dirt racetracks and specifically to evaluate the effect of a toe grab shoe compared to a flat racing plate, using a newly developed wireless data acquisition system (WDAS). METHODS: Four Thoroughbred racehorses in training and racing were used. Based on previous trials, each horse served as its own control for speed trials, with shoe type as variable. Horses were evaluated at speeds ranging from 12.0-17.3 m/sec. Impact accelerations, acceleration on break over and take-off, and temporal stride parameters were calculated. Impact injury scores were also determined, using peak accelerations and the time over which they occurred. RESULTS: Recorded accelerations for the resultant vector (all horses all speeds) calculated from triaxial accelerometers ranged 96.3-251.1 g, depending on the phase of the impact event. An association was observed between shoe type and change in acceleration in individual horses, with 2 horses having increased g on initial impact with toe grab shoes in place. In the final impact phase, one horse had an increase of 110 g while wearing toe grab shoes. Increased accelerations were also observed on break over in 2 horses while wearing toe grab shoes. CONCLUSIONS: Shoe type may change impact accelerations significantly in an individual horse and could represent increased risk for injury. Further work is needed to determine if trends exist across a population. POTENTIAL RELEVANCE: The WDAS could be used for performance evaluation in individual horses to evaluate any component of the horse-performance surface interface, with the goal of minimising risk and optimising performance. |
|
| |
Address |
Richard S. Reynolds Jr. Comparative Orthopedic Research Laboratory, New Bolton Center, University of Pennsylvania School of Veterinary Medicine, Kennett Square, Pennsylvania 19348, USA |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0425-1644 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
PMID:17228583 |
Approved |
no |
|
| |
Call Number |
Equine Behaviour @ team @ |
Serial |
4024 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Zentall, T.R. |
|
| |
Title |
Mental time travel in animals: a challenging question |
Type |
Journal Article |
| |
Year |
2006 |
Publication |
Behavioural processes |
Abbreviated Journal |
Behav. Process. |
|
| |
Volume |
72 |
Issue |
2 |
Pages |
173-183 |
|
| |
Keywords |
Animals; *Behavior, Animal; Columbidae; Concept Formation; Conditioning, Operant; *Imagination; *Memory; Mental Recall; Planning Techniques; Rats; *Time Perception; Transfer (Psychology) |
|
| |
Abstract |
Humans have the ability to mentally recreate past events (using episodic memory) and imagine future events (by planning). The best evidence for such mental time travel is personal and thus subjective. For this reason, it is particularly difficult to study such behavior in animals. There is some indirect evidence, however, that animals have both episodic memory and the ability to plan for the future. When unexpectedly asked to do so, animals can report about their recent past experiences (episodic memory) and they also appear to be able to use the anticipation of a future event as the basis for a present action (planning). Thus, the ability to imagine past and future events may not be uniquely human. |
|
| |
Address |
Department of Psychology, University of Kentucky, Lexington, KY 40506-0044, USA. zentall@uky.edu |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0376-6357 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
PMID:16466863 |
Approved |
no |
|
| |
Call Number |
refbase @ user @ |
Serial |
218 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Zentall, T.R. |
|
| |
Title |
Timing, memory for intervals, and memory for untimed stimuli: The role of instructional ambiguity |
Type |
Journal Article |
| |
Year |
2006 |
Publication |
Behavioural processes |
Abbreviated Journal |
Behav. Process. |
|
| |
Volume |
71 |
Issue |
2-3 |
Pages |
88-97 |
|
| |
Keywords |
|
|
| |
Abstract |
Theories of animal timing have had to account for findings that the memory for the duration of a timed interval appears to be dramatically shorted within a short time of its termination. This finding has led to the subjective shortening hypothesis and it has been proposed to account for the poor memory that animals appear to have for the initial portion of a timed interval when a gap is inserted in the to-be-timed signal. It has also been proposed to account for the poor memory for a relatively long interval that has been discriminated from a shorter interval. I suggest here a simpler account in which ambiguity between the gap or retention interval and the intertrial interval results in resetting the clock, rather than forgetting the interval. The ambiguity hypothesis, together with a signal salience mechanism that determines how quickly the clock is reset at the start of the intertrial interval can account for the results of the reported timing experiments that have used the peak procedure. Furthermore, instructional ambiguity rather than memory loss may account for the results of many animal memory experiments that do not involve memory for time. |
|
| |
Address |
Department of Psychology, University of Kentucky, 202B Kastle Hall, Lexington, KY 40506-0044, USA. zentall@uky.edu |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0376-6357 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
PMID:16406373 |
Approved |
no |
|
| |
Call Number |
refbase @ user @ |
Serial |
219 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Heitor, F.; do Mar Oom, M.; Vicente, L. |
|
| |
Title |
Social relationships in a herd of Sorraia horses Part I. Correlates of social dominance and contexts of aggression |
Type |
Journal Article |
| |
Year |
2006 |
Publication |
Behavioural Processes |
Abbreviated Journal |
Behav. Process. |
|
| |
Volume |
73 |
Issue |
2 |
Pages |
170-177 |
|
| |
Keywords |
Age Factors; *Aggression; Animals; Female; *Hierarchy, Social; Horses/*psychology; Male; Sex Factors; *Social Dominance; *Social Environment; Statistics, Nonparametric |
|
| |
Abstract |
Factors related to dominance rank and the functions of aggression were studied in a herd of Sorraia horses, Equus caballus, under extensive management. Subjects were 10 adult mares 5-18 years old and a stallion introduced into the group for breeding. Dominance relationships among mares were clear, irrespective of rank difference, and remained stable after introduction of the stallion. The dominance hierarchy was significantly linear and rank was positively correlated with age and total aggressiveness. Higher-ranking mares received lower frequency and intensity of agonistic interactions. Nevertheless, higher-ranking dominants were not more likely to elicit submission from their subordinates than lower-ranking dominants. Neither close-ranking mares nor mares with less clear dominance relationships were more aggressive towards each other. Agonistic interactions seemed to be used more importantly in regulation of space than to obtain access to food or to reassert dominance relationships. Contexts of aggression were related to mare rank. The results suggest that dominance relationships based on age as a conventional criterion were established to reduce aggressiveness in a herd where the costs of aggression are likely to outweigh the benefits. |
|
| |
Address |
Centro de Biologia Ambiental, Faculdade de Ciencias da Universidade de Lisboa, Campo Grande, Edificio C2, 1749-016 Lisboa, Portugal |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0376-6357 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
PMID:16815645 |
Approved |
no |
|
| |
Call Number |
refbase @ user @ |
Serial |
292 |
|
| Permanent link to this record |
