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McClure, S. R., & Chaffin, M. K. (1993). Self-mutilative behavior in horses. J Am Vet Med Assoc, 202(2), 179–180.
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Povinelli DJ, Rulf AB, Landau KR, & Bierschwale DT. (1993). Self-recognition in chimpanzees (Pan troglodytes): distribution, ontogeny, and patterns of emergence. J. Comp. Psychol., 107, 347.
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Pickerel, T. M., Crowell-Davis, S. L., Caudle, A. B., & Estep, D. Q. (1993). Sexual preference of mares (Equus caballus) for individual stallions. Appl. Anim. Behav. Sci., 38(1), 1–13.
Abstract: Eight mares were tested to determine if they remained near one of two stallions longer than would be expected if association was random. Six stallions were paired in 30 combinations and each mare was tested 30 times. The mares (Equus caballus) demonstrated a definite preference for individual stallions throughout the breeding season. This preference was influenced by the estrous state of the mare. During estrus, mares' preferences for stallions were positively correlated with the rate at which a given stallion vocalized. During diestrus, mares spent significantly less time in the proximity of stallions and did not exhibit any preference for individual stallions.
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Chalmeau, R., & Gallo, A. (1993). Social constraints determine what is learned in the chimpanzee. Behav. Process., 28(3), 173–179.
Abstract: A group of six chimpanzees was placed in a social learning situation, without training. The learning task was an operant conditioning situation; that is, a subject had to pull two handles simultaneously to cause a piece of fruit to fall into the cage. Only three individuals acquired the operant behaviour. For the operant individuals, social influences on the expression of the learning task were then examined; the dominant chimpanzee during feeding had an inhibiting effect when close to the operant subjects. Depending on the subject, social factors may influence not only the specific expression of what is learnt, but also the nature of what is learnt. Chimpanzees appear to experience situations differently: they develop an individual problem-solving strategy according to their social relationships even if the experimental procedure is the same for all.
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Barton, R. A. (1993). Sociospatial mechanisms of feeding competition in female olive baboons, Papio anubis. Anim. Behav., 46(4), 791–802.
Abstract: Abstract. Social and spatial mechanisms of feeding competition among adult female olive baboons were studied in two free-ranging groups, one foraging for natural foods, and one that was being provisioned. Similar behavioural processes were found to underlie rank-related differences in food intake in the two situations. Dominance rank of females in the naturally foraging group was positively correlated with the rate at which other animals were supplanted from feeding sites, the ratio of supplants of others to supplants received, and the number of near neighbours while feeding on clumped foods. It is unlikely that the latter result was due to rank-related differences in matriline size, because no significant correlations between rank and neighbour density were found for non-feeding activities. Step-wise regression analysis indicated that both number of neighbours and the supplant ratio explained significant proportions of inter-individual variance in daily food intake, though only the supplant ratio contributed significantly to feeding rate. High-ranking females also had priority of access to feeding sites within trees, and competition was most intense for foods that were spatially clumped. Similarly, in the provisioned group, rank was correlated with the rate at which supplants were received, and with spatial indices estimating centrality and the area of unoccupied space around an individual. Over 99% of the inter-individual variance in feeding rate was explained in a step-wise regression with supplant rates and spatial indices as independent variables. It is concluded that both active supplanting and individuals' spatial positions within the group mediate rank-related differences in food intake.
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Herbert, T. B., & Cohen, S. (1993). Stress and immunity in humans: a meta-analytic review. Psychosomatic Medicine, 55(4).
Abstract: : This article presents a meta-analysis of the literature on stress and immunity in humans. The primary analyses include all relevant studies irrespective of the measure or manipulation of stress. The results of these analyses show substantial evidence for a relation between stress and decreases in functional immune measures (proliferative response to mitogens and natural killer cell activity). Stress is also related to numbers and percent of circulating white blood cells, immunoglobulin levels, and antibody titers to herpesviruses. Subsequent analyses suggest that objective stressful events are related to larger immune changes than subjective self-reports of stress, that immune response varies with stressor duration, and that interpersonal events are related to different immune outcomes than nonsocial events. We discuss the way neuroendocrine mechanisms and health practices might explain immune alteration following stress, and outline issues that need to be investigated in this area. Copyright (C) 1993 by American Psychosomatic Society
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McGlone, J. J., & Hicks, T. A. (1993). Teaching standard agricultural practices that are known to be painful. J. Anim Sci., 71(4), 1071–1074.
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Clayton, H. M. (1993). The extended canter: a comparison of some kinematic variables in horses trained for dressage and for racing. Acta Anat (Basel), 146(2-3), 183–187.
Abstract: This study was designed to test the hypothesis that there is no significant difference in selected temporal and linear stride variables of the extended canter in horses bred and trained for dressage or racing. Nine advanced-level dressage horses and 7 Thoroughbred racehorses were filmed at a frame rate of 200 Hz at an extended canter on a sand track. Two strides were recorded per trial, and each horse performed 6 or 7 trials. Temporal and linear data were determined from the films, and descriptive statistics (mean, SD) were calculated. Strides were selected for analysis on the basis of having a velocity in the range of 6.0-7.0 m/s, and multivariate analysis of variance was used to detect significant differences in the stride kinematics of horses trained for the two sports (p < or = 0.01). The average velocity of the dressage horses was 6.37 m/s, compared with 6.40 m/s for the racehorses. There were no significant differences between the two groups in velocity, stride duration, stride length or the distances between limb placements. The stance durations of all four limbs and the overlaps between them were longer, whereas the duration of the suspension phase was shorter in the dressage horses than in the racehorses (p < or = 0.01). The time between impacts of the diagonal limb pair was close to zero in both groups, with individual horses showing some variability in the order of placement of the diagonal limb pair. However, the sequence of footfalls was not significantly different between the two groups (p < or = 0.01).
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Beveridge, W. I. (1993). Unravelling the ecology of influenza A virus. Hist Philos Life Sci, 15(1), 23–32.
Abstract: For 20 years after the influenza A virus was discovered in the early 1930s, it was believed to be almost exclusively a human virus. But in the 1950s closely related viruses were discovered in diseases of horses, pigs and birds. Subsequently influenza A viruses were found to occur frequently in many species of birds, particularly ducks, usually without causing disease. Researchers showed that human and animal strains can hybridise thus producing new strains. Such hybrids may be the cause of pandemics in man. Most pandemics have started in China or eastern Russia where many people are in intimate association with animals. This situation provides a breeding ground for new strains of influenza A virus.
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Schuhmann K,. (1993). Untersuchung zur Sozialstruktur des persischen Wildesels. Doctoral thesis, , Freiburg.
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