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Author Hemelrijk, C.K.; Wantia, J. doi  openurl
  Title Individual variation by self-organisation Type Journal Article
  Year 2005 Publication Neuroscience and biobehavioral reviews Abbreviated Journal Neurosci Biobehav Rev  
  Volume 29 Issue 1 Pages 125-136  
  Keywords Aggression; Animals; Behavior, Animal/*physiology; Competitive Behavior/*physiology; Female; Humans; *Individuality; Male; Models, Psychological; Sex Characteristics; *Social Dominance; Time Factors  
  Abstract In this paper, we show that differences in dominance and spatial centrality of individuals in a group may arise through self-organisation. Our instrument is a model, called DomWorld, that represents two traits that are often found in animals, namely grouping and competing. In this model individual differences grow under the following conditions: (1) when the intensity of aggression increases and grouping becomes denser, (2) when the degree of sexual dimorphism in fighting power increases. In this case the differences among females compared to males grow too, (3) when, upon encountering another individual, the tendency to attack is 'obligate' and not conditional, namely 'sensitive to risks'. Results resemble phenomena described for societies of primates, mice, birds and pigs.  
  Address Theoretical Biology, University of Groningen, NN Haren, The Netherlands. hemelrij@ifi.unizh.ch  
  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 0149-7634 ISBN Medium  
  Area (up) Expedition Conference  
  Notes PMID:15652260 Approved no  
  Call Number refbase @ user @ Serial 443  
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Author Rapin, V.; Poncet, P.A.; Burger, D.; Mermod, C.; Richard, M.A. doi  openurl
  Title [Measurement of the attention time in the horse] Type Journal Article
  Year 2007 Publication Schweizer Archiv fur Tierheilkunde Abbreviated Journal Schweiz Arch Tierheilkd  
  Volume 149 Issue 2 Pages 77-83  
  Keywords Age Factors; Animals; *Attention/physiology; Conditioning, Operant; Cross-Over Studies; Female; Horses/*physiology; Learning/*physiology; Male; Memory/*physiology; Time Factors  
  Abstract A study carried out on 49 horses showed that it is possible to measure the attention time by operant conditioning. After teaching horses an instrumental task using a signal, we were then able to test their attention time by asking them to prolong it increasingly while setting success and failure criteria. Two tests were performed 3 weeks apart. The 2nd test was feasible without relearning, a proof of memory, and was repeatable, a proof of consistency in the attention time. A significant difference was observed between the 3 age groups. Young horses often performed very well during the 1st test but their attention dropped in the 2nd test while older horses were more stable with respect to attention and even increased it slightly. The study shows that there are individual differences but it was not possible to prove a significant influence of breed, gender and paternal influence. Consequently, learning appears to be one of the most interesting approaches for evaluating the attention of horses and for observing their behaviour.  
  Address Laboratoire d'Ecoethologie, Universite de Neuchatel, Suisse. veronique.rapin@unine.ch  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language French Summary Language Original Title Mesure de la duree d'attention chez le cheval  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0036-7281 ISBN Medium  
  Area (up) Expedition Conference  
  Notes PMID:17343134 Approved no  
  Call Number Serial 1770  
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Author Bobbert, M.F.; Santamaria, S. doi  openurl
  Title Contribution of the forelimbs and hindlimbs of the horse to mechanical energy changes in jumping Type Journal Article
  Year 2005 Publication The Journal of Experimental Biology Abbreviated Journal J Exp Biol  
  Volume 208 Issue 2 Pages 249-260  
  Keywords Animals; Biomechanics; Forelimb/*physiology; Hindlimb/*physiology; Horses/*physiology; Locomotion/*physiology; Muscle, Skeletal/*physiology; Time Factors  
  Abstract The purpose of the present study was to gain more insight into the contribution of the forelimbs and hindlimbs of the horse to energy changes during the push-off for a jump. For this purpose, we collected kinematic data at 240 Hz from 23 5-year-old Warmbloods (average mass: 595 kg) performing free jumps over a 1.15 m high fence. From these data, we calculated the changes in mechanical energy and the changes in limb length and joint angles. The force carried by the forelimbs and the amount of energy stored was estimated from the distance between elbow and hoof, assuming that this part of the leg behaved as a linear spring. During the forelimb push, the total energy first decreased by 3.2 J kg(-1) and then increased again by 4.2 J kg(-1) to the end of the forelimb push. At the end of the forelimb push, the kinetic energy due to horizontal velocity of the centre of mass was 1.6 J kg(-1) less than at the start, while the effective energy (energy contributing to jump height) was 2.3 J kg(-1) greater. It was investigated to what extent these changes could involve passive spring-like behaviour of the forelimbs. The amount of energy stored and re-utilized in the distal tendons during the forelimb push was estimated to be on average 0.4 J kg(-1) in the trailing forelimb and 0.23 J kg(-1) in the leading forelimb. This means that a considerable amount of energy was first dissipated and subsequently regenerated by muscles, with triceps brachii probably being the most important contributor. During the hindlimb push, the muscles of the leg were primarily producing energy. The total increase in energy was 2.5 J kg(-1) and the peak power output amounted to 71 W kg(-1).  
  Address Institute for Fundamental and Clinical Human Movement Sciences, Vrije Universiteit, van der Boechorstraat 9, NL-1081 BT Amsterdam, The Netherlands. MFBobbert@fbw.vu.nl  
  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 0022-0949 ISBN Medium  
  Area (up) Expedition Conference  
  Notes PMID:15634844 Approved no  
  Call Number Serial 1895  
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Author Donnelly, J.; Phipps, L.P.; Watkins, K.L. doi  openurl
  Title Evidence of maternal antibodies to Babesia equi and B caballi in foals of seropositive mares Type Journal Article
  Year 1982 Publication Equine Veterinary Journal Abbreviated Journal Equine Vet J  
  Volume 14 Issue 2 Pages 126-128  
  Keywords Animals; Antibodies/*analysis; Babesia/*immunology; Complement Fixation Tests; Female; Horses/*immunology; Immunity, Maternally-Acquired; Male; Time Factors  
  Abstract  
  Address  
  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 (up) Expedition Conference  
  Notes PMID:7084196 Approved no  
  Call Number Equine Behaviour @ team @ Serial 2280  
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Author Reichmuth Kastak, C.; Schusterman, R.J. doi  openurl
  Title Long-term memory for concepts in a California sea lion ( Zalophus californianus) Type Journal Article
  Year 2002 Publication Animal Cognition Abbreviated Journal Anim. Cogn.  
  Volume 5 Issue 4 Pages 225-232  
  Keywords Animals; Concept Formation; Female; Memory/*physiology; Mental Processes; Sea Lions/physiology/*psychology; Time Factors  
  Abstract An adult California sea lion ( Zalophus californianus) with extensive experience in performing discrimination learning tasks was tested to evaluate her long-term memory for two previously learned concepts. An associative concept, that of equivalence classification, was retested after a retention interval of approximately 1 year. The sea lion had originally shown emergent equivalence classification with nonsimilarity-based classes of stimuli in a simple discrimination repeated-reversal procedure as well as in a matching-to-sample procedure. The 1-year memory test revealed no decrement in classification performance in either procedure. A relational concept, that of generalized identity matching, was retested after approximately 10 years. The sea lion had originally received trial-and-error exemplar training with identity matching-to-sample problems prior to transferring the concept to novel stimulus configurations. In the 10-year memory test, the sea lion immediately and reliably applied the previously established identity concept to familiar and novel sets of matching problems. These are the first reports of long-term conceptual memory in a nonprimate species. The experimental findings are consistent with a variety of observations of sea lions in natural settings, which indicate that natal sites, feeding areas, and individuals may be remembered over long periods of time.  
  Address Long Marine Laboratory, University of California at Santa Cruz, 100 Shaffer Road, Santa Cruz, CA 95060, USA. coll@cats.ucsc.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 1435-9448 ISBN Medium  
  Area (up) Expedition Conference  
  Notes PMID:12461600 Approved no  
  Call Number Equine Behaviour @ team @ Serial 2590  
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Author Waite, T.A. doi  openurl
  Title Interruptions improve choice performance in gray jays: prolonged information processing versus minimization of costly errors Type Journal Article
  Year 2002 Publication Animal Cognition Abbreviated Journal Anim. Cogn.  
  Volume 5 Issue 4 Pages 209-214  
  Keywords Animals; *Behavior, Animal; *Choice Behavior; Female; Learning; Male; Models, Biological; Motivation; Reinforcement Schedule; Songbirds/*physiology; Time Factors  
  Abstract Under the assumption that selection favors minimization of costly errors, erroneous choice may be common when its fitness cost is low. According to an adaptive-choice model, this cost depends on the rate at which an animal encounters the choice: the higher this rate, the smaller the cost of choosing a less valuable option. Errors should thus be more common when interruptions to foraging are shorter. A previous experiment supported this prediction: gray jays, Perisoreus canadensis, were more error prone when subjected to shorter delays to access to food rewards. This pattern, though, is also predicted by an attentional-constraints model. Because the subjects were able to inspect the rewards during delays, their improved performance when subjected to longer delays could have been a byproduct of the experimentally prolonged opportunity for information processing. To evaluate this possibility, a follow-up experiment manipulated both delay to access and whether rewards could be inspected during delays. Depriving jays of the opportunity to inspect rewards (using opaque lids) induced only a small, nonsignificant increase in error rate. This effect was independent of length of delay and so the jays' improved performance when subjected to longer delays was not simply a byproduct of prolonged information processing. More definitively, even when the jays were prevented from inspecting rewards during delays, their performance improved when subjected to longer delays. The findings are thus consistent with the adaptive-choice model.  
  Address Department of Evolution, Ecology, and Organismal Biology, Ohio State University, 1735 Neil Avenue, Columbus, OH 43210-1293, USA. waite.1@osu.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 1435-9448 ISBN Medium  
  Area (up) Expedition Conference  
  Notes PMID:12461598 Approved no  
  Call Number Equine Behaviour @ team @ Serial 2592  
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Author Bottoms, G.D.; Roesel, O.F.; Rausch, F.D.; Akins, E.L. openurl 
  Title Circadian variation in plasma cortisol and corticosterone in pigs and mares Type Journal Article
  Year 1972 Publication American Journal of Veterinary Research Abbreviated Journal Am J Vet Res  
  Volume 33 Issue 4 Pages 785-790  
  Keywords Animals; *Circadian Rhythm; Corticosterone/*blood; Female; Horses/*metabolism; Hydrocortisone/*blood; Methods; Swine/*metabolism; Time Factors  
  Abstract  
  Address  
  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 0002-9645 ISBN Medium  
  Area (up) Expedition Conference  
  Notes PMID:5017871 Approved no  
  Call Number Equine Behaviour @ team @ Serial 4074  
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Author Touma, C.; Sachser, N.; Mostl, E.; Palme, R. openurl 
  Title Effects of sex and time of day on metabolism and excretion of corticosterone in urine and feces of mice Type Journal Article
  Year 2003 Publication General and Comparative Endocrinology Abbreviated Journal Gen Comp Endocrinol  
  Volume 130 Issue 3 Pages 267-278  
  Keywords Animals; Chromatography, High Pressure Liquid; Circadian Rhythm/*physiology; Corticosterone/*metabolism/urine; Feces/*chemistry; Female; Immunoenzyme Techniques; Kinetics; Male; Mice; Mice, Inbred C57BL; Reference Values; Sex Factors; Stress/metabolism; Time Factors; Tritium  
  Abstract Non-invasive techniques to monitor stress hormones in small animals like mice offer several advantages and are highly demanded in laboratory as well as in field research. Since knowledge about the species-specific metabolism and excretion of glucocorticoids is essential to develop such a technique, we conducted radiometabolism studies in mice (Mus musculus f. domesticus, strain C57BL/6J). Each mouse was injected intraperitoneally with 740 kBq of 3H-labelled corticosterone and all voided urine and fecal samples were collected for five days. In a first experiment 16 animals (eight of each sex) received the injection at 9 a.m., while eight mice (four of each sex) were injected at 9 p.m. in a second experiment. In both experiments radioactive metabolites were recovered predominantly in the feces, although males excreted significantly higher proportions via the feces (about 73%) than females (about 53%). Peak radioactivity in the urine was detected within about 2h after injection, while in the feces peak concentrations were observed later (depending on the time of injection: about 10h postinjection in experiment 1 and about 4h postinjection in experiment 2, thus proving an effect of the time of day). The number and relative abundance of fecal [3H]corticosterone metabolites was determined by high performance liquid chromatography (HPLC). The HPLC separations revealed that corticosterone was extensively metabolized mainly to more polar substances. Regarding the types of metabolites formed, significant differences were found between males and females, but not between the experiments. Additionally, the immunoreactivity of these metabolites was assessed by screening the HPLC fractions with four enzyme immunoassays (EIA). However, only a newly established EIA for 5alpha-pregnane-3beta,11beta,21-triol-20-one (measuring corticosterone metabolites with a 5alpha-3beta,11beta-diol structure) detected several peaks of radioactive metabolites with high intensity in both sexes, while the other EIAs showed only minor immunoreactivity. Thus, our study for the first time provides substantial information about metabolism and excretion of corticosterone in urine and feces of mice and is the first demonstrating a significant impact of the animals' sex and the time of day. Based on these data it should be possible to monitor adrenocortical activity non-invasively in this species by measuring fecal corticosterone metabolites with the newly developed EIA. Since mice are extensively used in research world-wide, this could open new perspectives in various fields from ecology to behavioral endocrinology.  
  Address Department of Behavioral Biology, Institute of Neuro and Behavioral Biology, University of Muenster, Badestrasse 9, D-48149 Muenster, Germany. touma@uni-muenster.de  
  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 0016-6480 ISBN Medium  
  Area (up) Expedition Conference  
  Notes PMID:12606269 Approved no  
  Call Number Equine Behaviour @ team @ Serial 4086  
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Author Steiner, M. openurl 
  Title Biomechanics of tendon healing Type Journal Article
  Year 1982 Publication Journal of Biomechanics Abbreviated Journal J Biomech  
  Volume 15 Issue 12 Pages 951-958  
  Keywords Achilles Tendon/injuries; Animals; Biomechanics; Rats; Tendon Injuries/pathology/*physiopathology; Tensile Strength; Time Factors; *Wound Healing  
  Abstract The biomechanics of tendon healing was investigated with unsutured rat achilles tendons. After two, three, and four weeks of healing tensile parameters were assayed with a bone-muscle-tendon-bone preparation elongated to failure at a controlled physiological strain rate. In the third week of healing, stiffness, strength, and energy absorbing capacity all increased approximately 50%. These changes correlated with early fibroplasia. In the fourth week of healing, strength, energy absorbing capacity and elongation to failure all increased relatively more than stiffness. Histologically, larger fibers with better longitudinal alignment developed during this period. At the end of four weeks the tendon's strength was approximately 25% of normal. To summarize, the return of stiffness in a healing tendon preparation correlated with the presence of fibroplasia and the return of other tensile parameters was a function of the amount and organization of the fibroplasia.  
  Address  
  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 0021-9290 ISBN Medium  
  Area (up) Expedition Conference  
  Notes PMID:7166555 Approved no  
  Call Number Equine Behaviour @ team @ Serial 4448  
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Author Rands, S.A.; Cowlishaw, G.; Pettifor, R.A.; Rowcliffe, J.M.; Johnstone, R.A. url  doi
openurl 
  Title Spontaneous emergence of leaders and followers in foraging pairs Type Journal Article
  Year 2003 Publication Nature Abbreviated Journal Nature  
  Volume 423 Issue 6938 Pages 432-434  
  Keywords Animals; *Energy Metabolism; Food; *Food Chain; *Models, Biological; Motor Activity; *Social Behavior; Time Factors  
  Abstract Animals that forage socially often stand to gain from coordination of their behaviour. Yet it is not known how group members reach a consensus on the timing of foraging bouts. Here we demonstrate a simple process by which this may occur. We develop a state-dependent, dynamic game model of foraging by a pair of animals, in which each individual chooses between resting or foraging during a series of consecutive periods, so as to maximize its own individual chances of survival. We find that, if there is an advantage to foraging together, the equilibrium behaviour of both individuals becomes highly synchronized. As a result of this synchronization, differences in the energetic reserves of the two players spontaneously develop, leading them to adopt different behavioural roles. The individual with lower reserves emerges as the 'pace-maker' who determines when the pair should forage, providing a straightforward resolution to the problem of group coordination. Moreover, the strategy that gives rise to this behaviour can be implemented by a simple 'rule of thumb' that requires no detailed knowledge of the state of other individuals.  
  Address Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK. s.rands@zoo.cam.ac.uk  
  Corporate Author Thesis  
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  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0028-0836 ISBN Medium  
  Area (up) Expedition Conference  
  Notes PMID:12761547 Approved no  
  Call Number Equine Behaviour @ team @ Serial 5138  
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