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Fleck C., & Eifler D. (2003). Deformation behaviour and damage accumulation of cortical bone specimens from the equine tibia under cyclic loading. Journal of Biomechanics, 36, 179–189.
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Baragli, P., Cozzi, A., Rugani, R., Sighieria, C., & Regolin, L. (2008). Delayed search for non-social goals by Equids (Equus caballus and Equus asinus). In IESM 2008.
Abstract: Delayed-responses have been traditionally employed to investigate the temporal characteristics of animals“ ability to represent and recall objects that have disappeared. In the typical condition, the animal, usually a mammal, observes the experimenter hiding an interesting goal (e.g. some food) in a certain location. A delayed-response task (DRT) was administered to 4 female Esperia pony (2 years old) coming from a free-range breed (Frosinone, Italy) and to 7 female Amiata donkeys (4.2±2 years old) coming from a conservation stock (University of Pisa, Italy). The DRT's apparatus was located in a square fence. A single ”U-shaped“ screen (330x160x140 cm) made by wood shavings blocks was positioned in the centre of the fence. A gap (40x50 cm) on the ground was in the middle of the central side of the U-shaped-screen and served to make the food-attractor disappear. The food-attractor consisted in cereal flakes and fresh grass for ponies and cereal flakes for donkeys. A bucket full of food was placed on a dolly tied on a rope which could be pulled by an experimenter. In a preliminary training each animal was allowed to eat food from the bucket and, while the animal was eating, the dolly was gently pulled away from the animal, and beyond the screen through the gap. The subjects needed to move around of the screen in order to retrieve the food. As a reinforcement, they were allowed to eat some food from the bucket once behind the screen. From trial to trial, the bucket was presented farther and farther (starting with a distance of 1 m in front of the screen to reach 7 m). Therefore subjects were tested in the DRT requiring them to rejoin the bucket with the goal-food disappearing behind the screen as in the preliminary training but following a 10 s delay. For the DRT, the bucket was placed 7 m in front of the screen, 3 m away from the animal's starting area. Then the dolly was pulled away from the animal. Ten seconds after the disappearance of the dolly behind the screen the animal was released from the starting area. The DRT ended when the subject had reached the attractor behind the screen on 3 consecutive trials. Results showed that all animals were able to rejoin the food behind the screen after 10 s delay. The mean time of the delayed-response (mean±sd, in s) in the ponies (1st: 19.8±8; 2nd: 10.8±2.2; 3rd: 12.8±2.8) and in the donkeys (1st: 28.4±10; 2nd: 26.9±13; 3rd: 24.3±16.6) showed a trend to decrease from first trial to third. These preliminary results suggest that like other mammals our ponies and donkeys can maintain a working memory trace of the location where biologically attractive objects have been seen to disappear. In conclusion, this study paves the way to set up a viable model system for the investigation of the more sophisticated aspects of Equids” cognitive abilities such as working memory.
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List, C. (2004). Democracy in animal groups: a political science perspective. Trends Ecol Evol, 19(4), 168–169.
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Stout, I. J., Clifford, C. M., Keirans, J. E., & Portman, R. W. (1971). Dermacentor variabilis (Say) (Acarina: Ixodidae) established in southeastern Washington and northern Idaho. J Med Entomol, 8(2), 143–147.
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Ecker, C., Marquand, A., Mourao-Miranda, J., Johnston, P., Daly, E. M., Brammer, M. J., et al. (2010). Describing the Brain in Autism in Five Dimensions--Magnetic Resonance Imaging-Assisted Diagnosis of Autism Spectrum Disorder Using a Multiparameter Classification Approach. J. Neurosci., 30(32), 10612–10623.
Abstract: Autism spectrum disorder (ASD) is a neurodevelopmental condition with multiple causes, comorbid conditions, and a wide range in the type and severity of symptoms expressed by different individuals. This makes the neuroanatomy of autism inherently difficult to describe. Here, we demonstrate how a multiparameter classification approach can be used to characterize the complex and subtle structural pattern of gray matter anatomy implicated in adults with ASD, and to reveal spatially distributed patterns of discriminating regions for a variety of parameters describing brain anatomy. A set of five morphological parameters including volumetric and geometric features at each spatial location on the cortical surface was used to discriminate between people with ASD and controls using a support vector machine (SVM) analytic approach, and to find a spatially distributed pattern of regions with maximal classification weights. On the basis of these patterns, SVM was able to identify individuals with ASD at a sensitivity and specificity of up to 90% and 80%, respectively. However, the ability of individual cortical features to discriminate between groups was highly variable, and the discriminating patterns of regions varied across parameters. The classification was specific to ASD rather than neurodevelopmental conditions in general (e.g., attention deficit hyperactivity disorder). Our results confirm the hypothesis that the neuroanatomy of autism is truly multidimensional, and affects multiple and most likely independent cortical features. The spatial patterns detected using SVM may help further exploration of the specific genetic and neuropathological underpinnings of ASD, and provide new insights into the most likely multifactorial etiology of the condition.
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Hemelrijk, C. K. (2002). Despotic societies, sexual attraction and the emergence of male 'tolerance': an agent-based model. Behaviour, 139(6), 729–747.
Abstract: During the period when females are sexually attractive – but only then – males of certain species of primates, such as chimpanzees, allow females access to resources. Because males are usually dominant over females, such male 'tolerance' is explained as a special, reproductive strategy to gain access to females. In this paper a simpler hypothesis is proposed on the basis of an individual-based model (called DomWorld): male 'tolerance' towards females arises in 'despotic' artificial societies as a kind of 'respectful timidity', because sexual attraction automatically increases female dominance over males as a side-effect. The model consists in a homogeneous, virtual world with agents that group and perform dominance-interactions in which the effects of victory and defeat are self-reinforcing. The artificial sexes differ in that VirtualMales have a higher intensity of aggression, they start with a greater capacity to win conflicts than VirtualFemales and they are especially attracted to the opposite sex during certain periods, whereas VirtualFemales are not. I shall explain how the introduction into DomWorld of the attraction of VirtualMales by VirtualFemales leads to female dominance, why it does so only in despotic, but not in egalitarian societies, and how it leads to other phenomena that are relevant to the study of primate behaviour.
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Dirikolu, L., Lehner, A. F., Karpiesiuk, W., Hughes, C., Woods, W. E., Boyles, J., et al. (2003). Detection, quantification, metabolism, and behavioral effects of selegiline in horses. Vet Ther, 4(3), 257–268.
Abstract: Selegiline ([R]-[-]N,alpha-dimethyl-N-2- propynylphenethylamine or l-deprenyl), an irreversible inhibitor of monoamine oxidase, is a classic antidyskinetic and antiparkinsonian agent widely used in human medicine both as monotherapy and as an adjunct to levodopa therapy. Selegiline is classified by the Association of Racing Commissioners International (ARCI) as a class 2 agent, and is considered to have high abuse potential in racing horses. A highly sensitive LC/MS/MS quantitative analytical method has been developed for selegiline and its potential metabolites amphetamine and methamphetamine using commercially available deuterated analogs of these compounds as internal standards. After administering 40 mg of selegiline orally to two horses, relatively low (<60 ng/ml) concentrations of parent selegiline, amphetamine, and methamphetamine were recovered in urine samples. However, relatively high urinary concentrations of another selegiline metabolite were found, tentatively identified as N- desmethylselegiline. This metabolite was synthesized and found to be indistinguishable from the new metabolite recovered from horse urine, thereby confirming the chemical identity of the equine metabolite. Additionally, analysis of urine samples from four horses dosed with 50 mg of selegiline confirmed that N-desmethylselegiline is the major urinary metabolite of selegiline in horses. In related behavior studies, p.o. and i.v. administration of 30 mg of selegiline produced no significant changes in either locomotor activities or heart rates.
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Colahan, P., Lindsey, E., & Nunier, C. (1993). Determination of the center of pressure of the hoofs of the forelimbs of horses standing on a flat level surface. Acta Anat (Basel), 146(2-3), 175–178.
Abstract: The pressure exerted on a flat level surface by recently trimmed, unshod hoofs of the front limbs of 23 sound, adult horses was measured using pressure-sensitive film and a specially built cassette. The horses were tranquilized and stood with one foot on the 2.9-cm-thick cassette and the other on a block of equal height. The hoofs were observed for motion during the measurement, and the developed film was examined for improper alignment of the film or slipping of the hoof. The center of pressure was located using the method of weighted proportions of Barrey. This static measurement system with a long measurement time and the number of measurements reduced the influence of variables inherent in the horses' behavior and the measuring system. The calculated point was recorded as falling medial to, lateral to or on a line bisecting the central sulcus of the frog. In the dorsal to palmar orientation the point was classified with reference to a line drawn halfway between the most dorsal and the most palmar mark on the film. Forty-six percent of the calculated centers of pressure were located in the medial heel area. Binomial analysis for large samples indicates that this was a significant variation from a random distribution. Seventy-six percent of the centers were located in or on the borders of the medial heel.
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Baragli, P., Vitale, V., Paoletti, E., Sighieri, C., & Reddon, A. R. (2011). Detour behaviour in horses (Equus caballus). J. Ethol., 29(2), 227–234.
Abstract: The objective of this study was to investigate the ability of horses (Equus caballus) to detour around symmetric and asymmetric obstacles. Ten female Italian saddle horses were each used in three detour tasks. In the first task, the ability to detour around a symmetrical obstacle was evaluated; in the second and third tasks subjects were required to perform a detour around an asymmetrical obstacle with two different degrees of asymmetry. The direction chosen to move around the obstacle and time required to make the detour were recorded. The results suggest that horses have the spatial abilities required to perform detour tasks with both symmetric and asymmetric obstacles. The strategy used to perform the task varied between subjects. For five horses, lateralized behaviour was observed when detouring the obstacle; this was consistently in one direction (three on the left and two on the right). For these horses, no evidence of spatial learning or reasoning was found. The other five horses did not solve this task in a lateralized manner, and a trend towards decreasing lateralization was observed as asymmetry, and hence task difficulty, increased. These non-lateralized horses may have higher spatial reasoning abilities.
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Bussières, G., Jacques, C., Lainay, O., Beauchamp, G., Leblond, A., Cadoré, J. - L., et al. (2008). Development of a composite orthopaedic pain scale in horses. Research in Veterinary Science, 85(2), 294–306.
Abstract: This study addresses development and validation of a composite multifactorial pain scale (CPS) in an experimental equine model of acute orthopaedic pain. Eighteen horses were allocated to control (sedation with/without epidural analgesia – mixture of morphine, ropivacaine, detomidine and ketamine) and experimental groups: amphotericin-B injection in the tarsocrural joint induced pain and analgesia was either i.v. phenylbutazone administered post-induction of synovitis, or pre-emptive epidural mixture, or a pre-emptive combination of the 2. Inter- and intra-observer reproducibility was good (0.8<K<1). The key specific and sensitive behavioural indices were response to palpation of the painful area, posture, and, of lesser value, pawing on the floor, kicking at abdomen and head movement. Of particular interest was the statistical correlation observed between the CPS and both non-invasive blood pressure (P<0.0001) and blood cortisol (P<0.002). This study established the value of some behavioural and physiological criteria in determining equine orthopaedic pain intensity and clearly demonstrated that pre-emptive, multimodal analgesia provided better management than the two other protocols tested.
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