Dugatkin, L. A., & Godin, J. G. (1992). Reversal of female mate choice by copying in the guppy (Poecilia reticulata). Proc Biol Sci, 249(1325), 179–184.
Abstract: Ever since Fisher (1958) formalized models of sexual selection, female mate choice has been assumed to be a genetically determined trait. Females, however, may also use social cues to select mates. One such cue might be the mate choice of conspecifics. Here we report the first direct evidence that a female's preference for a particular male can in fact be reversed by social cues. In our experiments using the Trinidadian guppy (Poecilia reticulata), this reversal was mediated by mate-copying opportunities, such that a female (the 'focal' female) is given the opportunity to choose between two males, followed by a period in which she observes a second female (the 'model' female) displaying a preference for the male she herself did not prefer initially. When allowed to choose between the same males a second time, compared with control tests, a significant proportion of focal females reversed their mate choice and copied the preference of the model female. These results provide strong evidence for the role of non-genetic factors in sexual selection and underlie the need for new models of sexual selection that explicitly incorporate both genetic and cultural aspects of mate choice.
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Harkins, J. D., Kamerling, S. G., & Church, G. (1992). Effect of competition on performance of thoroughbred racehorses. J Appl Physiol, 72(3), 836–841.
Abstract: The effect of competition and the influence of age and sex on performance were examined in a study of 18 Thoroughbred racehorses. The horses performed two solo and two competitive runs at 1,200 and 1,600 m for a total of eight runs. No group ran faster during competition, which may have been a reflection of the quality of horses used for this study and their susceptibility to stress-induced impairment of performance. Males showed no significant difference between competitive and solo run times, whereas females were consistently slower during competition. Males ran significantly faster than females in all runs. There was no difference in run times due to age, which may have been due to the high mean age (5.9 yr) of the group. The slower competitive run times may have occurred because of an earlier onset of fatigue when compared with solo runs. Plasma lactate was significantly greater for the 1,200-m competitive than for the solo runs.
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Dvoinos, G. M., Kharchenko, V. A., & Zviagnitsova, N. S. (1992). The characteristics of the helminth community in the Turkmen kulan (Equus hemionus). Parazitologiia, 26(3), 246–251.
Abstract: The helminth fauna of 24 kulans from Askaniya-Nova and Badkhyz was studied. 42 species of helminths were found, 34 of which belong to strongylids. The helminth species composition of kulan is similar to that of other species of horses. This is a result of an intensive parasite exchange in the historical past when numerous populations of different Equidae species made long seasonal migrations over steppe inter-river lands of Asia and grazed for some time on common pastures.
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Eisgruber, H., & Stolle, F. A. (1992). [Clostridia in carcasses and fresh meat--a literature review]. Zentralbl Veterinarmed B, 39(10), 746–754.
Abstract: Clostridia are of large clinical importance as well as in the field of food hygiene, where they are responsible for spoilage but they also have a certain significance as food poisoning organisms. Information on the ecology of Clostridia in samples of deep muscle tissue of slaughtered animals is insufficient. This article is intended to increase the knowledge on the occurrence of different Clostridia species in slaughtered animals. The main emphasis is put on the significance of clostridia in meat hygiene. The theoretical basis of the so called original content of microorganisms (intrinsic bacteria), the factors and pathways of Clostridia spreading in muscles and organs are demonstrated.
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Bazovska, S., Awad-Masalmeh, M., Kmety, E., & Spalekova, M. (1992). [Legionella antibodies in domestic animals]. Cesk Epidemiol Mikrobiol Imunol, 41(5), 268–273.
Abstract: Serological examination of 420 domestic animals for the presence of antilegionella antibodies indicates their high exposure to legionellae. On examination by the microagglutination reaction with a serum dilution of 1:64 or more the highest positive values were recorded in horses which reacted with antigens of L. pneumophila 1-14 in 36.2% and with antigens of another 19 types of legionellae in 47.8%. In pigs positive values recorded in 16.2% and in 21.1%; in cattle in 3.8% and 29.5%, in sheep in 7.5% and 11.3% and laboratory rabbits were quite negative. The importance of these findings with regard to the possible role of animals in the ecology of legionellae is obscure.
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Novacek, M. J. (1992). Mammalian phylogeny: shaking the tree. Nature, 356(6365), 121–125.
Abstract: Recent palaeontological discoveries and the correspondence between molecular and morphological results provide fresh insight on the deep structure of mammalian phylogeny. This new wave of research, however, has yet to resolve some important issues.
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Dart, A. J., Snyder, J. R., Pascoe, J. R., Meagher, D. M., & Wilson, W. D. (1992). Prepurchase evaluation of horses: 134 cases (1988-1990). J Am Vet Med Assoc, 201(7), 1061–1067.
Abstract: To quantify some components of prepurchase evaluations in horses, records from 134 evaluations performed during a 2-year period were reviewed and the outcome was determined via telephone follow-up interview. Sixty-two percent of the prepurchase evaluations had been performed at the clinic and 38% had been performed in the field by the ambulatory service. All evaluations included physical and lameness examinations, whereas radiography (49%), endoscopy (15%), nerve blocking (5%), transrectal palpation (3%), hematologic analysis (2%), electrocardiography (2%), drug testing for analgesic agents (2%), and ultrasonography of the flexor tendons (1%) were not always performed. Fifty-nine percent of horses evaluated at the clinic were radiographed, compared with 33% of horses evaluated in the field (P less than 0.05). Thirty-seven percent of horses evaluated were judged serviceable for their intended use. Thirty-five percent of horses evaluated at the clinic were assessed to be serviceable, compared with 41% of those evaluated in the field (P less than 0.05). Horses used for pleasure riding (48%) tended to be considered serviceable more often than horses used for more athletic endeavors (3-day eventing, 33%; hunter/jumper, 24%; show, 31%; dressage, 30%). The most common basis for finding a horse unserviceable was lameness (88%).(ABSTRACT TRUNCATED AT 250 WORDS)
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Gutierrez Rincon, J. A., Vives Turco, J., Muro Martinez, I., & Casas Vaque, I. (1992). A comparative study of the metabolic effort expended by horse riders during a jumping competition. Br J Sports Med, 26(1), 33–35.
Abstract: The three main Olympic horse riding disciplines are dressage, jumping, and three-day eventing (including dressage, cross country and jumping). In the jumping discipline (obstacle race), the 'team' (horse rider) is judged under the different conditions that might take place in a varied run. The horse is expected to show power and ability; the rider must show riding skill and good physical condition. However, the different conditions encountered by the rider during competition (duration of event, continuous isometric working level, especially in the inferior trunk, lead us to consider the need for a rider to develop different metabolic pathways to meet the high energy requirements of the competition.
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Hertsch, B. (1992). [The appearance of stress on the movement apparatus in dressage, jumping and versatility horses]. Dtsch Tierarztl Wochenschr, 99(1), 36–39.
Abstract: Jumping and military (three days events) horses are exposed, during sports activities, to a particularly high stress especially in the region of the extremities (limbs). The genesis of tendon, joint and bone diseases are traced in accordance to the centers of the load during movement sequence. A special statistics on injuries concerning the German competition horses does not exist yet. Out of the available statistics about the German competition horses it is not obvious that as a result of its use as sports horses a particular high loss occur among these horses.
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Steinhoff, H. J., Schrader, J., & Schlitter, J. (1992). Temperature-jump studies and polarized absorption spectroscopy of methemoglobin-thiocyanate single crystals. Biochim Biophys Acta, 1121(3), 269–278.
Abstract: Association equilibria and association kinetics of the thiocyanate binding reaction to methemoglobin in single crystals and solution are studied using temperature-jump technique and polarized absorption spectroscopy. Different kinetic constants are found for the reaction in solution and crystal phase for the alpha- and beta-subunits of the methemoglobin tetramer. The reduction of the reactivity of the alpha- and beta-subunits in crystalline phase is 6-fold and 2.4-fold, respectively, compared to the values found in solution. The intramolecular binding reaction of the N epsilon of the distal histidine E7 which is observed in methemoglobin in solution cannot be detected in single crystals. Our results suggest that crystallization of hemoglobin has little influence on small-scale structural fluctuations which are necessary for ligands to get to the binding sites and large-scale structural motions are suppressed.
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