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Weishaupt, M. A., Wiestner, T., von Peinen, K., Waldern, N., Roepstorff, L., van Weeren, R., et al. (2006). Effect of head and neck position on vertical ground reaction forces and interlimb coordination in the dressage horse ridden at walk and trot on a treadmill. Equine Vet J Suppl, (36), 387–392.
Abstract: REASONS FOR PERFORMING STUDY: Little is known in quantitative terms about the influence of different head-neck positions (HNPs) on the loading pattern of the locomotor apparatus. Therefore it is difficult to predict whether a specific riding technique is beneficial for the horse or if it may increase the risk for injury. OBJECTIVE: To improve the understanding of forelimb-hindlimb balance and its underlying temporal changes in relation to different head and neck positions. METHODS: Vertical ground reaction force and time parameters of each limb were measured in 7 high level dressage horses while being ridden at walk and trot on an instrumented treadmill in 6 predetermined HNPs: HNP1 – free, unrestrained with loose reins; HNP2 – neck raised, bridge of the nose in front of the vertical; HNP3 – neck raised, bridge of the nose behind the vertical; HNP4 – neck lowered and flexed, bridge of the nose considerably behind the vertical; HNP5 – neck extremely elevated and bridge of the nose considerably in front of the vertical; HNP6 – neck and head extended forward and downward. Positions were judged by a qualified dressage judge. HNPs were assessed by comparing the data to a velocity-matched reference HNP (HNP2). Differences were tested using paired t test or Wilcoxon signed rank test (P<0.05). RESULTS: At the walk, stride duration and overreach distance increased in HNP1, but decreased in HNP3 and HNP5. Stride impulse was shifted to the forehand in HNP1 and HNP6, but shifted to the hindquarters in HNP5. At the trot, stride duration increased in HNP4 and HNP5. Overreach distance was shorter in HNP4. Stride impulse shifted to the hindquarters in HNP5. In HNP1 peak forces decreased in the forelimbs; in HNP5 peak forces increased in fore- and hindlimbs. CONCLUSIONS: HNP5 had the biggest impact on limb timing and load distribution and behaved inversely to HNP1 and HNP6. Shortening of forelimb stance duration in HNP5 increased peak forces although the percentage of stride impulse carried by the forelimbs decreased. POTENTIAL RELEVANCE: An extremely high HNP affects functionality much more than an extremely low neck.
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Weik, H., Lingk, W., & Altmann, H. J. (1972). [Behavior of individual fatty acids during in-vitro lipolysis and resynthesis in equine depot fat]. Zentralbl Veterinarmed A, 19(8), 677–685.
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Weik, H., & Altmann, J. (1972). The effect of L(+)-lactate on rat and horse adipose tissue in vitro. Zentralbl Veterinarmed A, 19(6), 514–518.
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Weik, H., & Altmann, H. J. (1971). [Behavior of blood lipids during fasting in the horse]. Zentralbl Veterinarmed A, 18(2), 131–138.
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Weed M.R., Taffe M.A., Polis I., Roberts A.C., Robbins T.W., Koob G.F., et al. (1999). Performance norms for a rhesus monkey neuropsychological testing battery: acquisition and long-term performance. Cognitive Brain Research, 8, 185–201.
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Watts, D. J., & Strogatz, S. H. (1998). Collective dynamics of /`small-world/' networks. Nature, 393(6684), 440–442.
Abstract: Networks of coupled dynamical systems have been used to model biological oscillators Josephson junction arrays excitable media, neural networks spatial games11, genetic control networks12 and many other self-organizing systems. Ordinarily, the connection topology is assumed to be either completely regular or completely random. But many biological, technological and social networks lie somewhere between these two extremes. Here we explore simple models of networks that can be tuned through this middle ground: regular networks 'rewired' to introduce increasing amounts of disorder. We find that these systems can be highly clustered, like regular lattices, yet have small characteristic path lengths, like random graphs. We call them 'small-world' networks, by analogy with the small-world phenomenon (popularly known as six degrees of separation). The neural network of the worm Caenorhabditis elegans, the power grid of the western United States, and the collaboration graph of film actors are shown to be small-world networks. Models of dynamical systems with small-world coupling display enhanced signal-propagation speed, computational power, and synchronizability. In particular, infectious diseases spread more easily in small-world networks than in regular lattices.
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Watson, L. H., Odendaal, H. E., Barry, T. J., & Pietersen, J. (2005). Population viability of Cape mountain zebra in Gamka Mountain Nature Reserve, South Africa: the influence of habitat and fire. Biol. Conserva., 122(2), 173–180.
Abstract: The small Cape mountain zebra population in Gamka Mountain Nature Reserve represents a third of the entire gene pool of this endangered species and is thus vital for it's conservation. Presently, management of this population is largely hands off, with the belief that it will grow to levels which will allow it to form a source for the mixing of mountain zebra stocks in the future. The growth of this population however, has been slow and we investigated the influence of habitat and fire on this growth. Firstly, we used a diffusion model to perform a population viability analysis. This analysis indicated that the population had a low probability of attaining quasi-extinction in the next 50 years (G = 0.0032). However, our findings indicated that less than 30% of the reserve was suitable for mountain zebra and that the preferred habitat would have to be burnt at unnaturally short intervals to sustain the present growth. We therefore argue that the risk of quasi-extinction to this population is greater than predicted and suggest that management options need to be implemented to reduce this risk. These options include; translocation to another protected area; acquisition of adjacent land; burning preferred habitat at unnaturally short intervals; forming a conservancy with adjacent landowners; leasing cultivated land for pasture. We suggest that only the latter two options are likely to stimulate mountain zebra population growth in the short term and that these should receive immediate attention.
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Washino, R. K., & Tempelis, C. H. (1967). Host-feeding patterns of Anopheles freeborni in the Sacramento Valley, California. J Med Entomol, 4(3), 311–314.
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Warmuth, V., Eriksson, A., Bower, M. A., Cañon, J., Cothran, G., Distl, O., et al. (2011). European Domestic Horses Originated in Two Holocene Refugia. PLoS ONE, 6(3), e18194 EP -.
Abstract: <p>The role of European wild horses in horse domestication is poorly understood. While the fossil record for wild horses in Europe prior to horse domestication is scarce, there have been suggestions that wild populations from various European regions might have contributed to the gene pool of domestic horses. To distinguish between regions where domestic populations are mainly descended from local wild stock and those where horses were largely imported, we investigated patterns of genetic diversity in 24 European horse breeds typed at 12 microsatellite loci. The distribution of high levels of genetic diversity in Europe coincides with the distribution of predominantly open landscapes prior to domestication, as suggested by simulation-based vegetation reconstructions, with breeds from Iberia and the Caspian Sea region having significantly higher genetic diversity than breeds from central Europe and the UK, which were largely forested at the time the first domestic horses appear there. Our results suggest that not only the Eastern steppes, but also the Iberian Peninsula provided refugia for wild horses in the Holocene, and that the genetic contribution of these wild populations to local domestic stock may have been considerable. In contrast, the consistently low levels of diversity in central Europe and the UK suggest that domestic horses in these regions largely derive from horses that were imported from the Eastern refugium, the Iberian refugium, or both.</p>
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Waring, G. H. (Ed.). (2002). Horse Behavior: The Behavioral Traits and Adaptations of Domestic and Wild Horses, Including Ponies. Nrowich, NY: Noyes Publications.
Abstract: Reviews
Synopsis
The second edition of this informative book remains the most comprehensive and current overview of the behavioral traits and adaptations of horses. The book integrates findings from hundreds of international researchers to provide the reader with a factual synthesis of the behaviour of domestic and feral horses. Building on the strengths of the first edition, the author has thoroughly updated coverage of horse ancestry, development, perception, learning, play, social behavioral manipulation, maintenance activities, and sexual behaviour. Throughout these and other chapters, more emphasis has been given to animal husbandry and management. Additionally, the second edition includes an all-new section on ecological influences on activity patterns, habitat utilization, social behaviour and reproduction. An expanded section on applied ethnology provides behavioral considerations or management and insight regarding the behavioral indicators of horse health and well being. This is followed with an updated appendix listing behavioral symptoms and possible causes. The text contains numerous tables and nearly 100 illustrations and photos. Interesting Facts: Rich with international data, incorporated into text, tables, and figures Two new chapters on ecological influences dealing with interactions between environment feeding, ranging, shelter seeking, reproductive and social behavior, among other topics New chapter on behavioral considerations in horse management, plus updated material on health and well being, surveys atypical symptoms ranging from posture to social behaviour Update appendix provides an extensive listing of behavioral symptoms, with identifications of possible associated problems.
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