Records |
Author |
Wilson, A.M.; McGuigan, M.P.; Su, A.; van Den Bogert, A.J. |
Title |
Horses damp the spring in their step |
Type |
Journal Article |
Year |
2001 |
Publication |
Nature |
Abbreviated Journal |
Nature |
Volume |
414 |
Issue |
6866 |
Pages |
895-899 |
Keywords |
Animals; Biomechanics; Elasticity; Forelimb; Gait; Horses/anatomy & histology/*physiology; Leg Bones/*physiology; Locomotion; Models, Biological; Muscle Fibers/physiology; Muscle, Skeletal/anatomy & histology/*physiology; Tendons/anatomy & histology/*physiology; Vibration |
Abstract |
The muscular work of galloping in horses is halved by storing and returning elastic strain energy in spring-like muscle-tendon units.These make the legs act like a child's pogo stick that is tuned to stretch and recoil at 2.5 strides per second. This mechanism is optimized by unique musculoskeletal adaptations: the digital flexor muscles have extremely short fibres and significant passive properties, whereas the tendons are very long and span several joints. Length change occurs by a stretching of the spring-like digital flexor tendons rather than through energetically expensive length changes in the muscle. Despite being apparently redundant for such a mechanism, the muscle fibres in the digital flexors are well developed. Here we show that the mechanical arrangement of the elastic leg permits it to vibrate at a higher frequency of 30-40 Hz that could cause fatigue damage to tendon and bone. Furthermore, we show that the digital flexor muscles have minimal ability to contribute to or regulate significantly the 2.5-Hz cycle of movement, but are ideally arranged to damp these high-frequency oscillations in the limb. |
Address |
Department of Veterinary Basic Sciences, The Royal Veterinary College, Hatfield, Herts AL9 7TA, UK. awilson@rvc.ac.uk |
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English |
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Series Issue |
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Edition |
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ISSN |
0028-0836 |
ISBN |
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Conference |
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Notes |
PMID:11780059 |
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no |
Call Number |
Equine Behaviour @ team @ |
Serial |
2300 |
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Author |
Whiten, A. |
Title |
Social complexity and social intelligence |
Type |
Conference Article |
Year |
2000 |
Publication |
Novartis Foundation Symposium |
Abbreviated Journal |
Novartis Found Symp |
Volume |
233 |
Issue |
|
Pages |
185-96; discussion 196-201 |
Keywords |
Animals; Brain/anatomy & histology/*physiology; Humans; *Intelligence/physiology; Learning; Models, Psychological; Primates; *Social Behavior; Social Problems |
Abstract |
When we talk of the 'nature of intelligence', or any other attribute, we may be referring to its essential structure, or to its place in nature, particularly the function it has evolved to serve. Here I examine both, from the perspective of the evolution of intelligence in primates. Over the last 20 years, the Social (or 'Machiavellian') Intelligence Hypothesis has gained empirical support. Its core claim is that the intelligence of primates is primarily an adaptation to the special complexities of primate social life. In addition to this hypothesis about the function of intellect, a secondary claim is that the very structure of intelligence has been moulded to be 'social' in character, an idea that presents a challenge to orthodox views of intelligence as a general-purpose capacity. I shall outline the principal components of social intelligence and the environment of social complexity it engages with. This raises the question of whether domain specificity is an appropriate characterization of social intelligence and its subcomponents, like theory of mind. As a counter-argument to such specificity I consider the hypothesis that great apes exhibit a cluster of advanced cognitive abilities that rest on a shared capacity for second-order mental representation. |
Address |
School of Psychology, University of St Andrews, St Andrews, Fife KY16 9JU, UK |
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English |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1528-2511 |
ISBN |
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Conference |
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Notes |
PMID:11276903 |
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no |
Call Number |
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Serial |
2084 |
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Author |
Wennerstrand, J.; Johnston, C.; Roethlisberger-Holm, K.; Erichsen, C.; Eksell, P.; Drevemo, S. |
Title |
Kinematic evaluation of the back in the sport horse with back pain |
Type |
Journal Article |
Year |
2004 |
Publication |
Equine Veterinary Journal |
Abbreviated Journal |
Equine Vet J |
Volume |
36 |
Issue |
8 |
Pages |
707-711 |
Keywords |
Animals; Back/*physiology; Back Pain/diagnosis/physiopathology/*veterinary; Biomechanics; Exercise Test/veterinary; Gait/*physiology; Horse Diseases/diagnosis/*physiopathology; Horses/anatomy & histology/*physiology; Locomotion/physiology; Lumbar Vertebrae/physiology; Range of Motion, Articular; Stress, Mechanical; Thoracic Vertebrae/physiology; Weight-Bearing |
Abstract |
REASONS FOR PERFORMING STUDY: Earlier studies have developed a clinical tool to evaluate objectively the function of the equine back. The ability to differentiate horses with back pain from asymptomatic, fully functioning horses using kinematic measures from this tool has not been evaluated. OBJECTIVES: To compare the kinematics of the back at walk and trot in riding horses with back dysfunction to the same parameters in asymptomatic sport horses. METHODS: The kinematics of the back in 12 horses with impaired performance and back pain were studied at walk and trot on a treadmill. Data were captured for 10 sees at 240 Hz. Range of movement (ROM) and intravertebral pattern symmetry of movement for flexion and extension (FE), lateral bending (LB) and axial rotation (AR) were derived from angular motion pattern data and the results compared to an earlier established database on asymptomatic riding horses. RESULTS: At walk, horses with back dysfunction had a ROM smaller for dorsoventral FE in the caudal thoracic region (T13 = 7.50 degrees, T17 = 7.71 degrees; P<0.05), greater for LB at T13 (8.13 degrees; P<0.001) and smaller for AR of the pelvis (10.97 degrees; P<0.05) compared to asymptomatic horses (FE-T13 = 8.28 degrees, FE-T17 = 8.49 degrees, LB-T13 = 6.34 degrees, AR-pelvis = 12.77 degrees). At trot, dysfunctional horses had a smaller (P<0.05) ROM for FE at the thoracic lumbar junction (T17 = 2.46 degrees, L1 = 2.60 degrees) compared to asymptomatic horses (FE-T17 = 3.07 degrees, FE-L1 = 3.12 degrees). CONCLUSIONS: The objective measurement technique can detect differences between back kinematics in riding horses with signs of back dysfunction and asymptomatic horses. The clinical manifestation of back pain results in diminished flexion/extension movement at or near the thoracic lumbar junction. However, before applying the method more extensively in practice it is necessary to evaluate it further, including measurements of patients whose diagnoses can be confirmed and long-term follow-ups of back patients after treatment. POTENTIAL RELEVANCE: Since the objective measurement technique can detect small movement differences in back kinematics, it should help to clinically describe and, importantly, objectively detect horses with back pain and dysfunction. |
Address |
Department of Anatomy and Physiology, Swedish University of Agricultural Sciences, SE-750 07 Uppsala, Sweden |
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English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0425-1644 |
ISBN |
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Area |
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Conference |
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Notes |
PMID:15656501 |
Approved |
no |
Call Number |
Equine Behaviour @ team @ |
Serial |
3656 |
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Author |
Vollmerhaus, B.; Roos, H.; Gerhards, H.; Knospe, C. |
Title |
[Phylogeny, form and function of canine teeth in the horse] |
Type |
Journal Article |
Year |
2003 |
Publication |
Anatomia, histologia, embryologia |
Abbreviated Journal |
Anat Histol Embryol |
Volume |
32 |
Issue |
4 |
Pages |
212-217 |
Keywords |
Animals; Cuspid/*anatomy & histology/radiography; Evolution; Horses/*anatomy & histology; Male; Phylogeny; *Social Dominance |
Abstract |
The canine teeth of the horse developed phylogenically from the simple, pointed, short-rooted tooth form of the leaf eating, in pairs living, Eocene horse Hyracotherium and served up to the Oligocene as a means of defense (self preservation). In the Miocene the living conditions of the Merychippus changed and they took to eating grass and adopted as a new behavior the life in a herd. The canine teeth possibly played an important role in fights for social ranking; they changed from a crown form to knife-like shape. In the Pliohippus the canine tooth usually remained in male horses and since the Pliocene, it contributed to the fights between stallions, to ensure that the offspring only came from the strongest animals (preservation of the species). Form and construction of the canine tooth are described and discussed in detail under the above mentioned phylogenic and ethologic aspects. |
Address |
Institut fur Tieranatomie und Chirurgische Tierklinik der Universitat Munchen, Veterinarstrasse 13, D 80539 Munchen, Deutschland. c-neumueller@anat.vetmed.uni-muenchen.de |
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Place of Publication |
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Editor |
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Language |
German |
Summary Language |
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Original Title |
[Zur Phylogenie, Form und Funktion der Dentes canini des Pferdes] |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0340-2096 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
PMID:12919071 |
Approved |
no |
Call Number |
refbase @ user @ |
Serial |
672 |
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Author |
van Heel, M.C.V.; Kroekenstoel, A.M.; van Dierendonck, M.C.; van Weeren, P.R.; Back, W. |
Title |
Uneven feet in a foal may develop as a consequence of lateral grazing behaviour induced by conformational traits |
Type |
Journal Article |
Year |
2006 |
Publication |
Equine veterinary journal |
Abbreviated Journal |
Equine. Vet. J. |
Volume |
38 |
Issue |
7 |
Pages |
646-651 |
Keywords |
Aging/*physiology; Animals; Animals, Newborn/anatomy & histology/growth & development/physiology; Feeding Behavior/*physiology; Female; Forelimb/*anatomy & histology/*physiology; *Horses/anatomy & histology/growth & development/physiology; Male |
Abstract |
REASONS FOR PERFORMING STUDY: Conformational traits are important in breeding, since they may be indicative for performance ability and susceptibility to injuries. OBJECTIVES: To study whether certain desired conformational traits of foals are related to lateralised behaviour while foraging and to the development of uneven feet. METHODS: Twenty-four Warmblood foals, born and raised at the same location, were studied for a year. Foraging behaviour was observed by means of weekly 10 min scan-sampling for 8 h. A preference test (PT) was developed to serve as a standardised tool to determine laterality. The foals were evaluated at age 3, 15, 27 and 55 weeks. The PT and distal limb conformation were used to study the relation between overall body conformation, laterality and the development of uneven feet. Pressure measurements were used to determine the loading patterns under the feet. RESULTS: About 50% of the foals developed a significant preference to protract the same limb systematically while grazing, which resulted in uneven feet and subsequently uneven loading patterns. Foals with relatively long limbs and small heads were predisposed to develop laterality and, consequently unevenness. CONCLUSIONS: Conformational traits may stimulate the development of laterality and therefore indirectly cause uneven feet. |
Address |
Derona Equine Performance Laboratory, Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 12, NL-3584 CM Utrecht, The Netherlands |
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English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0425-1644 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
PMID:17228580 |
Approved |
no |
Call Number |
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Serial |
1774 |
Permanent link to this record |
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Author |
Staniar, W.B.; Kronfeld, D.S.; Hoffman, R.M.; Wilson, J.A.; Harris, P.A. |
Title |
Weight prediction from linear measures of growing Thoroughbreds |
Type |
Journal Article |
Year |
2004 |
Publication |
Equine veterinary journal |
Abbreviated Journal |
Equine Vet J |
Volume |
36 |
Issue |
2 |
Pages |
149-154 |
Keywords |
Animal Nutrition Physiology; Animals; Biometry; Body Weight/*physiology; Female; Horses/*anatomy & histology/*growth & development; Male; Mathematics; Predictive Value of Tests; Reproducibility of Results; Sensitivity and Specificity |
Abstract |
REASON FOR PERFORMING STUDY: Monitoring weight of foals is a useful management practice to aid in maximising athletic potential while minimising risks associated with deviations from normal growth. OBJECTIVE: To develop predictive equations for weight, based on linear measurements of growing Thoroughbreds (TBs). METHODS: Morphometric equations predicting weight from measurements of the trunk and legs were developed from data of 153 foals. The accuracy, precision and bias of the best fitting equation were compared to published equations using a naive data set of 22 foals. RESULTS: Accuracy and precision were maximised with a broken line relating calculated volumes (V(t + l)) to measured weights. Use of the broken line is a 2 step process. V(t + l) is calculated from linear measures (m) of girth (G), carpus circumference (C), and length of body (B) and left forelimb (F). V(t + I) = ([G2 x B] + 4[C2 x F]) 4pi. If V(t + l) < 0.27 m3, weight is estimated: Weight (kg) = V(t + l) x 1093. If V(t + l) > or = 0.27 m3: Weight (kg) = V(t + l) x 984 + 24. The broken line was more accurate and precise than 3 published equations predicting the weight of young TBs. CONCLUSIONS: Estimation of weight using morphometric equations requires attention to temporal changes in body shape and density; hence, a broken line is needed. Including calculated leg volume in the broken line model is another contributing factor to improvement in predictive capability. POTENTIAL RELEVANCE: The broken line maximises its value to equine professionals through its accuracy, precision and convenience. |
Address |
Department of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061-0306, USA |
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English |
Summary Language |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0425-1644 |
ISBN |
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Area |
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Notes |
PMID:15038438 |
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no |
Call Number |
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Serial |
1806 |
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Author |
Stadler, P.; Rewel, A.; Deegen, E. |
Title |
[M-mode echocardiography in dressage horses, class S jumping horses and untrained horses] |
Type |
Journal Article |
Year |
1993 |
Publication |
Zentralblatt fur Veterinarmedizin. Reihe A |
Abbreviated Journal |
Zentralbl Veterinarmed A |
Volume |
40 |
Issue |
4 |
Pages |
292-306 |
Keywords |
Animals; Echocardiography/*veterinary; Female; Heart Septum/ultrasonography; Heart Ventricles/ultrasonography; Horses/*anatomy & histology; Male; *Physical Conditioning, Animal; Reference Values |
Abstract |
Heart structures of 45 warmblooded horses were measured by M-mode-echocardiography. The current training level of 15 dressage horses (group I) and 15 show-jumping horses (group II) was category “S”. In the third group were 15 untrained horses. Four standardized transducer positions were determined for the m-mode echobeam, calibrated according to the two-dimensional real time technique. End systolic and end diastolic diameters of left ventricle, right ventricle, aortic root, interventricular septum and left ventricular wall, as well as motion pattern of heart wall, mitral valve and aortic valve of all horses were measured. The dressage horses showed a significant thickening of interventricular septum and left-ventricular wall compared with the show-jumping horses and the untrained horses. The end diastolic left ventricle diameter of the show-jumping horses was significantly larger than in the other groups. Compared to the untrained horses the show-jumping horses showed a significantly larger end systolic left ventricular wall diameter measured at the level of papillary muscle. It can be concluded, that an increase in heart mass in category “S” sport horses is attributed to their level of training. |
Address |
Klinik fur Pferde der Tierarztlichen Hochschule Hannover |
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Language |
German |
Summary Language |
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Original Title |
Die M-mode-Echokardiographie bei S-Dressur-, S-Springpferden und bei untrainierten Pferden |
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Edition |
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ISSN |
0514-7158 |
ISBN |
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Medium |
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Notes |
PMID:8342361 |
Approved |
no |
Call Number |
Equine Behaviour @ team @ |
Serial |
3749 |
Permanent link to this record |
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Author |
Sivak, J.G.; Allen, D.B. |
Title |
An evaluation of the “ramp” retina of the horse eye |
Type |
Journal Article |
Year |
1975 |
Publication |
Vision Research |
Abbreviated Journal |
Vision Res |
Volume |
15 |
Issue |
12 |
Pages |
1353-1356 |
Keywords |
Accommodation, Ocular; Animals; Aqueous Humor/physiology; Cornea/physiology; Freezing; Horses/*anatomy & histology; Lens, Crystalline/anatomy & histology/physiology; Refraction, Ocular; Retina/*anatomy & histology; Vitreous Body/physiology |
Abstract |
Using a rapid freezing and sectioning technique, the distance between the lens and retina of the horse eye was measured. There is no indication of a ramp retina that could serve accommodation. The pupil axis of the eye coincides with the maximum lens to retina distance. The changes in the lens-retina distance are greater below the axis than above it. Calculations were made of refractive power of the horse eye from measurements of curvature and refractive indices of the ocular tissues. These calculations agree both qualitatively and quantitatively with retinoscopic measurements on live horses. Both show that the refractive state shifts in the direction of hyperopia above and below the axis and that this shift is greater below the axis than above it. Some dynamic accommodative ability in the living eye was observed. |
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English |
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Edition |
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ISSN |
0042-6989 |
ISBN |
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Medium |
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Notes |
PMID:1210017 |
Approved |
no |
Call Number |
Equine Behaviour @ team @ |
Serial |
3647 |
Permanent link to this record |
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Author |
Shultz, S.; Dunbar, R.I.M. |
Title |
Both social and ecological factors predict ungulate brain size |
Type |
Journal Article |
Year |
2006 |
Publication |
Proceedings. Biological Sciences / The Royal Society |
Abbreviated Journal |
Proc Biol Sci |
Volume |
273 |
Issue |
1583 |
Pages |
207-215 |
Keywords |
Animals; Artiodactyla/*anatomy & histology/*physiology; Brain/*anatomy & histology/physiology; *Ecosystem; Organ Size; Perissodactyla/*anatomy & histology/*physiology; *Social Behavior |
Abstract |
Among mammals, the members of some Orders have relatively large brains. Alternative explanations for this have emphasized either social or ecological selection pressures favouring greater information-processing capacities, including large group size, greater foraging efficiency, higher innovation rates, better invasion success and complex problem solving. However, the focal taxa for these analyses (primates, carnivores and birds) often show both varied ecological competence and social complexity. Here, we focus on the specific relationship between social complexity and brain size in ungulates, a group with relatively simple patterns of resource use, but extremely varied social behaviours. The statistical approach we used, phylogenetic generalized least squares, showed that relative brain size was independently associated with sociality and social complexity as well as with habitat use, while relative neocortex size is associated with social but not ecological factors. A simple index of sociality was a better predictor of both total brain and neocortex size than group size, which may indicate that the cognitive demands of sociality depend on the nature of social relationships as well as the total number of individuals in a group. |
Address |
School of Biological Sciences, University of Liverpool, Biosciences Building, Crown Street, Liverpool L69 7ZB, UK. susanne.shultz@liv.ac.uk |
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English |
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ISSN |
0962-8452 |
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Notes |
PMID:16555789 |
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no |
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Serial |
2098 |
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Author |
Shoshani, J.; Kupsky, W.J.; Marchant, G.H. |
Title |
Elephant brain. Part I: gross morphology, functions, comparative anatomy, and evolution |
Type |
Journal Article |
Year |
2006 |
Publication |
Brain Research Bulletin |
Abbreviated Journal |
Brain Res Bull |
Volume |
70 |
Issue |
2 |
Pages |
124-157 |
Keywords |
Animals; Brain/*anatomy & histology/blood supply/*physiology; Cats; Chinchilla; Elephants/*anatomy & histology/*physiology; Equidae; *Evolution; Female; Guinea Pigs; Haplorhini; Humans; Hyraxes; Male; Pan troglodytes; Sheep; Wolves |
Abstract |
We report morphological data on brains of four African, Loxodonta africana, and three Asian elephants, Elephas maximus, and compare findings to literature. Brains exhibit a gyral pattern more complex and with more numerous gyri than in primates, humans included, and in carnivores, but less complex than in cetaceans. Cerebral frontal, parietal, temporal, limbic, and insular lobes are well developed, whereas the occipital lobe is relatively small. The insula is not as opercularized as in man. The temporal lobe is disproportionately large and expands laterally. Humans and elephants have three parallel temporal gyri: superior, middle, and inferior. Hippocampal sizes in elephants and humans are comparable, but proportionally smaller in elephant. A possible carotid rete was observed at the base of the brain. Brain size appears to be related to body size, ecology, sociality, and longevity. Elephant adult brain averages 4783 g, the largest among living and extinct terrestrial mammals; elephant neonate brain averages 50% of its adult brain weight (25% in humans). Cerebellar weight averages 18.6% of brain (1.8 times larger than in humans). During evolution, encephalization quotient has increased by 10-fold (0.2 for extinct Moeritherium, approximately 2.0 for extant elephants). We present 20 figures of the elephant brain, 16 of which contain new material. Similarities between human and elephant brains could be due to convergent evolution; both display mosaic characters and are highly derived mammals. Humans and elephants use and make tools and show a range of complex learning skills and behaviors. In elephants, the large amount of cerebral cortex, especially in the temporal lobe, and the well-developed olfactory system, structures associated with complex learning and behavioral functions in humans, may provide the substrate for such complex skills and behavior. |
Address |
Department of Biology, University of Asmara, P.O. Box 1220, Asmara, Eritrea (Horn of Africa). hezy@bio.uoa.edu.er |
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English |
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Series Volume |
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Edition |
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ISSN |
0361-9230 |
ISBN |
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Notes |
PMID:16782503 |
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no |
Call Number |
Equine Behaviour @ team @ |
Serial |
2623 |
Permanent link to this record |