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Kornblith, H. (2002). Knowledge and its Place in Nature. Oxford: Oxford University Press.
Abstract: Argues that conceptual analysis should be rejected in favour of a more naturalistic approach to epistemology. There is a robust natural phenomenon of knowledge; knowledge is a natural kind. An examination of the cognitive ethology literature reveals a category of knowledge that does both causal and explanatory work. It is argued that knowledge in this very sense is what philosophers have been talking about all along. Rival accounts of knowledge that are more demanding—requiring either that certain social conditions be met or that an agent engage in some sort of reflection—are discussed in detail, and it is argued that they are inadequate to the phenomenon. In addition, it is argued that the account of knowledge that emerges from the cognitive ethology literature can provide an explanation of the normative force of epistemic claims.
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Ratzlaff, M. H., Wilson, P. D., Hyde, M. L., Balch, O. K., & Grant, B. D. (1993). Relationship between locomotor forces, hoof position and joint motion during the support phase of the stride of galloping horses. Acta Anat (Basel), 146(2-3), 200–204.
Abstract: Three methods were used simultaneously to determine the relationships between the vertical forces exerted on the hooves and the positions of the limbs and hooves at the times of peak vertical forces from 2 horses galloping on a track straightaway. Vertical forces were recorded from an instrumented shoe, fetlock joint motion was measured with an electrogoniometer and the angles of the carpus, fetlock and hoof were determined from slow-motion films. At hoof contact, the mean angles of the carpus and fetlock were 181-182 degrees and 199-206 degrees, respectively. Peak vertical forces on the heel occurred at or near maximum extension of the carpal and fetlock joints. Peak forces on the toe occurred during flexion of the fetlock joint and at mean hoof angles of 28-31 degrees from the horizontal. The mean angles of the hoof from the horizontal at the time of heel contact were 6-7 degrees. Hoof lift occurred at mean carpal angles of 173-174 degrees and mean fetlock angles of 199-200 degrees.
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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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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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Argue, C. K., & Clayton, H. M. (1993). A preliminary study of transitions between the walk and trot in dressage horses. Acta Anat (Basel), 146(2-3), 179–182.
Abstract: The object of this study was to determine the limb support sequence during the transitions from walk to trot and from trot to walk in dressage horses under saddle and to test the null hypothesis that the limb support sequence during the transitions is not related to the level of training. Sixteen dressage horses training at novice to FEI Grand Prix level were videotaped performing an average of 9 transitions each from walk to trot and from trot to walk. The 30-Hz videotapes were viewed in slow motion, and based on the limb support sequence the transitions were categorized into two types. In type 1 transitions there were no intermediate steps between the walk and trot sequences. Type 2 transitions were characterized by intermediate steps, including a single support phase. The Kendall rank-order correlation coefficient showed that a higher level of training was positively associated with an increased percentage of type 1 transitions for both walk-to-trot transitions (p < or = 0.05) and trot-to-walk transitions (p < or = 0.01). No significant preference for initiating or completing the trot on the left or right diagonal was found using the binomial test for individual horses and the Wilcoxon signed-ranks test for the group.
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Czerlinski, G. H., Wagner, M., Erickson, J. O., & Theorell, H. (1975). Chemical relaxation studies on the system liver alcohol dehydrogenase, NADH and imidazole. Acta Chem Scand B, 29(8), 797–810.
Abstract: Several years ago, Theorell and Czerlinski conducted experiments on the system of horse liver alcohol dehydrogenase, reduced nicotinamide adenine dinucleotide and imidazole, using the first version of the temperature jump apparatus with detection of changes in fluorescence. These early experiments were repeated with improved instrumentation and confirmed the early experiments in general terms. However, the improved detection system allowed to measure a slight concentration dependence of the relaxation time of around 3 ms. Furthermore, the chemical relaxation time was smaller than the one determined earlier (by factor 2). The data were evaluated much more rigorously than before, allowing an appropriate interpretation of the results. The observed relaxation time is largely due to rate constants in an interconversion of ternary complexes, which are faster than three (of the four) dissociation rate constants, determined previously by Theorell and McKinley-McKee.1,2 This fact contributed to earlier difficulties of finding any concentration dependence. However, the binding of imidazole to the binary enzyme-coenzyme complex can be made to couple kinetically into the interconversion rate of the two ternary complexes. The observed signal derives largely from the ternary complex(es). A substantial fluorescence signal change is associated with the observed relaxation process, suggesting a relocation of the imidazole in reference to the nicotinamide moiety of the bound coenzyme. Nine models are considered with two types of coupling of pre-equilibria (none-all). Quantitative evaluations favor the model with two ternary complexes connected by an interconversion outside the four-step (bimolecular) cycle. The ternary complex outside the cycle has much higher fluorescence yield than the one inside. The interconversion equilibrium is near unity for imidazole. If it would be shifted very much to the side of the “dead-end” complex (as in isobutyramide?!), stimulating action could not take place.
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Levin, L. E., & Grillet, M. E. (1988). [Diversified leadership: a social solution of problems in schools of fish]. Acta Cient Venez, 39(2), 175–180. |
Yang, S. (2000). Melioidosis research in China. Acta Trop, 77(2), 157–165.
Abstract: Research on melioidosis and its pathogen has been ongoing in China for more than two decades. It has been demonstrated that the natural foci are located predominantly in Hainan, Guangdong and Guangxi province, where there is a good correlation between soil isolation and the serum prevalence of antibodies to Burkholderia pseudomallei. The cases of melioidosis reported up to now are concentrated in the Hainan and Zhanjiang peninsula. Investigations on serotype, virulence, ecology, antibiotic susceptibility, whole cell analysis by gas chromatography, and genetics have led to a new understanding of the pathology of the disease. Immunological cross reactions between Burkholderia mallei and B. pseudomallei and the difference between melioidosis and glanders in horses is discussed.
Keywords: Animals; Anti-Bacterial Agents/pharmacology; Burkholderia pseudomallei/drug effects/immunology/*pathogenicity; China/epidemiology; Cross Reactions; Glanders/immunology/microbiology; Horses; Humans; *Melioidosis/epidemiology/immunology/microbiology/veterinary; Seroepidemiologic Studies; Virulence
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Mejdell, C. M., Simensen, E., & Boe, K. E. (2005). Is snow a sufficient source of water for horses kept outdoors in winter? A case report. Acta Vet Scand, 46(1-2), 19–22.
Abstract: Due to extreme weather conditions, a flock of outwintered Icelandic horses had to manage for several days on snow as the source of free water. They were fed grass silage ad lib, and any change in feed consumption was not observed. After nine days, blood samples were taken and analysed for plasma osmolality, they were subjected to a simple clinical examination, and offered drinking water. Osmolality levels were within normal limits and mean value did not differ significantly from samples which previously were taken of the same individuals. The general condition of the horses was normal, with no signs of clinical dehydration or disease. The horses showed very little interest for the offered drinking water. This suggests that in cold winter weather, horses being fed grass silage and adjusted to eat snow, can manage for several days with snow substituting liquid water without their physiology and welfare being challenged.
Keywords: Animals; *Drinking Behavior; *Horses; Norway; Osmolar Concentration; Snow; *Thirst; *Water Supply
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Nelson, G. S. (1970). Onchocerciasis. Adv Parasitol, 8, 173–224.
Keywords: Africa; Animals; Anthelmintics/therapeutic use; Artiodactyla; Blindness/etiology; Cattle; Circadian Rhythm; Ddt; Diethylcarbamazine/therapeutic use; Diptera/anatomy & histology/growth & development; Dwarfism/etiology; Ecology; Eye/pathology; Feeding Behavior; Female; Geography; Haplorhini; Hernia, Femoral/etiology; Horses; Humans; Insect Vectors/growth & development; Larva/growth & development; Male; Onchocerca/classification/growth & development; *Onchocerciasis/diagnosis/drug therapy/epidemiology/immunology/pathology/prevention & control/veterinary; Primates; Serologic Tests; Skin/pathology; Skin Tests; Suramin/therapeutic use
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