De Moraes Ferrari, E. A., & Todorov, J. C. (1980). Concurrent avoidance of shocks by pigeons pecking a key. J Exp Anal Behav., 30(3), 329–333.
Abstract: Three pigeons were studied on concurrent, unsignaled, avoidance schedules in a two-key procedure. Shock-shock intervals were two seconds in both schedules. The response-shock interval on one key was always 22 seconds, while the response-shock interval associated with the other key was varied from 7 to 52 seconds in different experimental conditions. Response rates on the key associated with the varied schedule tended to decrease when the response-shock interval length was increased. Responding on the key associated with the constant schedule was not systematically affected.
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Lewis, P., Gardner, E. T., & Lopatto, D. (1980). Shock-duration reduction as negative reinforcement. Psychol. Rec,, .
Abstract: In 2 experiments, 9 female Sprague-Dawley albino rats were shocked every 30 sec. Before the barpress response, shocks were long (2 sec); for 3 min after a response, shocks were short (0.1, 0.5, or 1 sec). When responding reduced shocks from 2 to 0.1 sec, barpressing was acquired, and the shorter the shocks the more time spent with the short-shock condition in effect. In another procedure, the duration of individual shocks following a response was controlled so that the 1st shock was as long as those before the response (2 sec), but the remaining shocks in the 3-min period were short (0.1 sec). Barpressing was maintained in some Ss and acquired in others showing that, even when delayed, a reduction in shock duration is reinforcing. These findings question the generality of a 2-factor, safety-signal interpretation of negative reinforcement. These results plus others imply that to predict responding in aversive situations it is necessary to integrate, for at least several minutes, the parameters of aversive events that follow a response. (27 ref) (PsycINFO Database Record (c) 2014 APA, all rights reserved)
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Hintz, R. L. (1980). Genetics of performance in the horse. J. Anim Sci., 51(3), 582–594.
Abstract: Criteria used to measure performance, environmental factors that influence performance and estimates of heritability are needed to estimate genetic differences. Published heritability estimates of various measures of performance in the horse are summarized. The average heritability estimates of pulling ability and cutting ability are .25 and .04, respectively. Heritability estimates are .18, .19 and .17 for log of earnings from jumping, 3-day event and dressage performance, respectively. Heritability estimates of performance rates, log of earnings, earnings, handicap weight, best handicap weight, time and best time for the Thoroughbred are .55, .49, .09, .49, .33, .15 and .23, respectively. Heritability estimates of log of earnings, earnings, time and best time for the trotter are .41, .20, .32, and .25, respectively. The heritability estimate of best time for the pacer is .23. The effectiveness of selection will depend on which performance trait is to be improved.
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Jeffcott, L. B., & Dalin, G. (1980). Natural rigaidity of the horse's backbone. Equine Vet J, 12(3), 101–108.
Abstract: The functional anatomy of the thoracolumbar (TL) spine is considered in relation to the horse's ability to perform at speed and to jump. The morphological features quite clearly show the relative inflexibility of the equine back and this was confirmed by some experimental studies. Fresh post mortem specimens from 5 Thoroughbreds were used to estimate the limits of dorsoventral movement of the TL spine from mid-thoracic to the cranial lumbar (T10-L2). The individual spinous processes could be moved a mean 1.1-6.0 mm on maximum ventroflexion and 0.8-3.8 mm on dorsiflexion. The overall flexibility of the back was found to be 53.1 mm. Caudal to the mid-point of the back (T13) there was virtually no lateral or rotatory movement of the spine possible. The pathogenesis of some of the common causes of back trouble are discussed including the so-called vertebral subluxation and its treatment by chiropractic manipulation. From an anatomical viewpoint, this condition appears to be a misnomer and may simply be attributable to muscular imbalance leading to aspastic scoliosis.
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Hasumi, H. (1980). Kinetic studies on isomerization of ferricytochrome c in alkaline and acid pH ranges by the circular dichroism stopped-flow method. Biochim Biophys Acta, 626(2), 265–276.
Abstract: The isomerization of horse-heart ferricytochrome c caused by varying pH was kinetically studied by using circular dichroism (CD) and optical absorption stopped-flow techniques. In the pH range of 7--13, the existence of the three different forms of ferricytochrome c (pH less than 10, pH 10--12, and pH greater than 12) was indicated from the statistical difference CD spectra. On the basis of analyses of the stopped-flow traces in the near-ultraviolet and Soret wavelength regions, the isomerization of ferricytochrome c from neutral form to the above three alkaline forms was interpreted as follows (1) below pH 10, the replacement of the intrinsic ligand of methionine residue by lysine residue occurs; (2) between pH 10 and 12, the uncoupling of the polypeptide chain from close proximity of the heme group occurs first, followed by the interconversion of the intrinsic ligands; and (3) above pH 12, hydroxide form of ferricytochrome c is formed, though the replacement of the intrinsic ligand by extrinsic ligands may occur via different routes from those below pH 12. The CD changes at 288 nm and in the Soret region caused by the pH-jump (down) from pH 6.0 to 1.6 were compared with the appearance of the 620-nm absorption band ascribed to the formation of the high-spin form of ferricytochrome c. Both CD and absorption changes indicated that the isomerization at pH 1.6 consisted of two processes: one proceeded within the dead-time (about 2 ms) of the stopped-flow apparatus and the other proceeded at a determinable rate with the apparatus. On the basis of these results, the isomerization of ferricytochrome c at pH 1.6 was explained as follows: (1) the transition from the low-spin form to the high-spin forms occurs within about 2 ms, the dead-time of the stopped-flow apparatus; and (2) the polypeptide chain is unfolded after the formation of the high-spin form.
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Bradley, B. L. (1980). Animal flavor types and their specific uses in compound feeds by species and age. Fortschr Tierphysiol Tierernahr, (11), 110–122.
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Karstens, H. (1980). Das Military Pferd.
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Parry, B. W., Gay, C. C., & McCarthy, M. A. (1980). Influence of head height on arterial blood pressure in standing horses. American Journal of Veterinary Research, 41(10), 1626–1631.
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Haag, E. L., Rudman, R., & Houpt, K. A. (1980). Avoidance, maze learning and social dominance in ponies. J. Anim. Sci., 50, 329–335.
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Appleby, M. C. (1980). Social Rank and Food Access in Red Deer Stags. Behaviour, 74, 294–309.
Abstract: The behaviour of a free-living group of male red deer (Cervus elaphus L.) on the Isle of Rhum, Scotland, was studied throughout the year to investigate the relations between social dominance and food access. The study is based on the collection of agonistic interactions between members of the study group outside the rutting season. Analysis of these confirmed that dyadic dominance relationships summate to a very clear agonistic hierarchy, while seasonal changes in frequency and type of interactions suggested that rank in the hierarchy may affect access to food through direct feeding interference. This would constitute a selective advantage of the acquisition of high rank. A behaviour pattern in which a stag displaces a subordinate and takes over his feeding-site is proposed as a mechanism of direct feeding interference. It occurs throughout the year, but with a frequency closely related to changes in food availability and quality. The proportion of such interactions that an individual wins is related to his rank, so advantages gained from this behaviour would primarily benefit high-ranking stags. These are likely to consist of improved body condition and winter survival. The importance of high rank in obtaining access to limited food was supported by the results of a simple experiment providing a small area of fertilized grass. Most of the grazing in the area was due to the highest-ranking stag present at any time.
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