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Birch, H. G. (1945). The relation of previous experience to insightful problem-solving. J Comp Psychol, 38, 367–383.
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Vervaecke, H., de Vries, H., & van Elsacker, L. (2000). The Pivotal Role Of Rank In Grooming And Support Behavior In A Captive Group Of Bonobos (Pan Paniscus). Behaviour, 137(11), 1463–1485.
Abstract: We investigated dyadic grooming relationships in a captive group of bonobos (Pan paniscus) and questioned what social function grooming fulfils in the 'market of services and favors'. Hereto we examined which of two theoretical models – grooming for support (Seyfarth, 1977, 1980) or grooming according to the similarity principle (de Waal & Luttrell, 1986) – best accounted for the observed grooming distribution. Similarity in traits did not correlate with increased grooming or close proximity among the individuals. Therefore, the similarity hypothesis was rejected. Seyfarth's model of rank-related grooming was largely confirmed. The animals distributed their grooming according to the rank of the receivers. We found an exchange between grooming and receipt of support. There was more grooming up than down the hierarchy. However, not all predictions about rank-related competition over grooming were confirmed. We found that dyadic grooming reciprocity indeed increased with decreasing rank distance. Yet, there was no increase of grooming within the dyad with decreasing rank distance and high ranking individuals were not competed over at the highest rates. The observed correlation between grooming and support received represents an important fit with Seyfarth's prediction, but does not allow for conclusions about underlying causal processes. Other causal explanations, besides the 'groom to receive support' hypothesis, that could explain a similar correlation are discussed.
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Meester J, S. H., & W. Setzer, H. W. (Eds.). (1971). The mammals of Africa (Vol. Part 14). City of Washington: Smithsonian Press.
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Petter-Puchner, A. H., Froetscher, W., Krametter-Froetscher, R., Lorinson, D., Redl, H., & van Griensven, M. (2007). The long-term neurocompatibility of human fibrin sealant and equine collagen as biomatrices in experimental spinal cord injury. Exp Toxicol Pathol, 58(4), 237–245.
Abstract: INTRODUCTION: While fibrin sealant (FS) and equine collagen (EC) have been used as scaffold materials in experimental spinal cord injury (SCI), questions concerning neurocompatibility still remain. In this study, we assessed potential adverse effects, as well as functional and histological impact of FS and EC in subtotal hemisection of the thoracic spinal cord (SC) in rats. METHODS: 124 male rats were randomly assigned to four main groups (n=31): Sham (SH), Lesion only (L), fibrin sealant (GFS) and equine collagen group (GEC). SH animals received laminectomy only; all other animals underwent subtotal lateral hemisection at T9. Treatment consisted of application of FS or EC into the lesion gap in GFS and GEC, which was left empty in L. GFS, GEC, L and SH were each further divided into 4 subgroups: One subgroup, consisting of 10 rats was subjected to behavioural and reflex testing before surgery and followed up on days 1,7, 14, 21, 28 post op and then sacrificed. Haemalaun or cresyl violet (CV) was used to identify neutrophils in parasagittal cord sections which were obtained on day 1 (n=7). Sections stained for quantification of microglia/macrophages using ED-1 on day 3 (n=7), day 7 (n=7) and day 28 (n=7 out of 10). Additionally, neural filament (NF) staining was chosen to detect axonal regeneration and the length of ingrowth into FS and EC, Luxol blue for myelination, Von Willebrand factor for vascularisation, and glial fibrillary acidic protein (GFAP) staining for detection of astrocytes in glial scars on day 28. RESULTS: No adverse effects were observed in the treatment groups. Compared to L, GFS and GEC performed significantly better in the Basso, Beattie, Bresnahan (BBB) score and hopping responses. Proprioceptive placing was markedly improved in FS and EC compared to L. Axonal regrowth was found in GFS and GEC--the regrowth in the GFS was accompanied by myelination and vascularisation. Glial scarring occurred in all groups. Discussion Both biomatrices improved functional recovery compared to L and no adverse effects were perceived.
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Clutton-Brock, T. H., Albon, S. D., Gibson, R. M., & Guinness, F. E. (1979). The logical stag: Adaptive aspects of fighting in red deer (Cervus elaphus L.). Anim. Behav., 27(Part 1), 211–225.
Abstract: For red deer stags, fighting both has appreciable costs and yields considerable benefits. Up to 6% of rutting stags are permanently injured each year, while fighting success and reproductive success are closely related, within age groups as well as across them. Fighting behaviour is sensitive to changes in the potential benefits of fighting: stags fight most frequently and most intensely where potential benefits are high and tend to avoid fighting with individuals they are unlikely to beat. The relevance of these findings to theoretical models of fighting behaviour is discussed.
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Meschan, E. M., Peham, C., Schobesberger, H., & Licka, T. F. (2007). The influence of the width of the saddle tree on the forces and the pressure distribution under the saddle. The Veterinary Journal, 173(3), 578–584.
Abstract: As there is no statistical evidence that saddle fit influences the load exerted on a horse's back this study was performed to assess the hypothesis that the width of the tree significantly alters the pressure distribution on the back beneath the saddle. Nineteen sound horses were ridden at walk and trot on a treadmill with three saddles differing only in tree width. Kinetic data were recorded by a sensor mat. A minimum of 14 motion cycles were used in each trial. The saddles were classified into four groups depending on fit. For each horse, the saddle with the lowest overall force (LOF) was determined. Saddles were classified as “too-narrow” if they were one size (2 cm) narrower than the LOF saddle, and “too-wide” if they were one size (2 cm) wider than the LOF saddle. Saddles two sizes wider than LOF saddles were classified as “very-wide”. In the group of narrow saddles, the pressure in the caudal third (walk 0.63 N/cm2 +/- 0.10; trot 1.08 N/cm2 +/- 0.26) was significantly higher compared to the LOF saddles (walk 0.50 N/cm2 +/- 0.09; trot 0.86 N/cm2 +/- 0.28). In the middle transversal third, the pressure of the wide saddles (walk 0.73 N/cm2 +/- 0.06; trot 1.52 N/cm2 +/- 0.19) and very-wide saddles (walk 0.77 N/cm2 +/- 0.06; trot 1.57 N/cm2 +/- 0.19) was significantly higher compared to LOF saddles (walk 0.65 N/cm2 +/- 0.10/ 0.63 N/cm2 +/- 0.11; trot 1.33 N/cm2 +/- 0.22/1.27 N/cm2 +/- 0.20). This study demonstrates that the load under poorly fitting saddles is distributed over a smaller area than under properly fitting saddles, leading to potentially harmful pressures peaks.
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Stevens, J., Vervaecke, H., de Vries, H., & Van Elsacker, L. (2005). The influence of the steepness of dominance hierarchies on reciprocity and interchange in captive groups of bonobos (Pan paniscus). Behaviour, 142(7), 941–960.
Abstract: Biological market models explain variability in reciprocity and interchange between groups. In groups with a shallow dominance gradient, grooming will be mostly exchanged for itself (i.e. exchange will occur). In groups with steep dominance hierarchies, interchange is expected: individuals will groom higher ranking individuals to get access to limited resources or commodities such as support in conflicts, and grooming will be traded for these commodities. We examine patterns of reciprocity in grooming and support, and of interchange of grooming for support or for tolerance in six captive groups of bonobos. We test whether differences between groups in patterns of reciprocity and interchange can be attributed to differences in a measure of steepness of dominance hierarchies, which is based on dyadic agonistic interactions. We found that grooming was reciprocal in some, but not all groups. Support was highly reciprocal, but this was a side effect of dominance in most groups. Interchange between grooming and support was observed in some groups. Corroborating earlier findings, this was a side effect of individuals preferring high ranking individuals as grooming and support partners, possibly because these high-ranking individuals provide more efficient support in conflicts. There was no evidence for interchange of grooming for tolerance. Variability in grooming reciprocity was explained by differences in steepness of dominance hierarchies, as predicted by the biological market models. In groups with a shallow dominance hierarchy, grooming was more reciprocal. This was not true for reciprocity in support. There was some evidence that individuals groomed dominants more frequently in groups with a steep dominance hierarchy. The variation in interchange relations between grooming and support did not depend on the steepness of dominance hierarchies. We suggest that grooming in itself is a valuable commodity in bonobos, especially under captive conditions, which can be exchanged reciprocally. Bonobos may interchange grooming for another value equivalent, with food sharing as a very likely candidate. This interchange effects seem more dependent on potential to monopolise food than on steepness of dominance hierarchies per se.
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Nitschelm D, H. V. D. C. (1977). The influence of chlormadinone acetate treatment on the concentration of some stereoids in the blood, on the ovarian activity, and on the sexual behaviour of the.. Tijdschr Diergeneesk, 102, 61–872.
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Nitschelm D, H. V. D. C. (1977). The influence of chlormadinone acetate treatment on the concentration of some stereoids in the blood, on the ovarian activity and on.. Tijdschr Diergeneesk, 102, 861–872.
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Davis, H., & Balfour, D. (Eds.). (1992). The Inevitable Bond: Examining Scientist-Animal Interactions. Cambridge, Massachusetts: Cambridge University Press.
Abstract: Book Description
Although animals are widely employed as research subjects, it is only recently that we have acknowledged the bond that frequently, perhaps inevitably, develops between subject and researcher. Whatever the qualities of this relationship, an increasing body of evidence suggests that it may result in profound behavioural and physiological changes in the animal subject. Such effects are apparent in behavioural studies conducted in both laboratory and field settings. They also appear in physiological studies ranging from the biomedical (e.g. heart rate, blood pressure, immunological changes) to animal science (e.g. growth, reproduction). Such effects are not confined to obvious cases involving primates and dogs, but appear in unexpected animals like chickens, reptiles and even octopuses. Despite the fact that most researchers are trained to minimise or avoid such interactions, they continue to occur. This book, the first of its kind to address this issue systematically, describes many examples of this “inevitable bond” between scientist and animal. This discussion will allow researchers to anticipate these potentially confounding effects and take advantage of such relationships in designing more effective and humane environments for animal subjects.
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