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Wagner, G. (1975). [Flight leadership in flocks of homing pigeons]. Z. Tierpsychol., (39), 61–74.
Abstract: Groups of 3-5 homing pigeons individually recognizable by different colours of their plumage were followed by helicopter on their way home. In most cases the animals flew together as a group with frequently changing leadership. Flight formations in terms of leadership were noted every minute. It was examined statistically whether the flight order varies at random or whether there are leading and led birds. In 6 out of 7 experiments with groups of 4-5 pigeons flight order was far from random, one or two pigeons proving to be leaders. In only one experiment leadership did not differ from a random distribution. No correlation could be found between the tendency to lead within a group and homing performance of the single pigeon when released individually.
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Belonje, P. C., & van Niekerk, C. H. (1975). A review of the influence of nutrition upon the oestrous cycle and early pregnancy in the mare. J Reprod Fertil Suppl, (23), 167–169.
Abstract: Attention is drawn to the beneficial effect of improved nutrition during winter and early spring on the ovarian activity of mares. Furthermore, the necessity of an adequate plane of nutrition during early pregnancy to prevent embryonic resorption is stressed.
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Wang, L. Y. (1975). Host preference of mosquito vectors of Japanese encephalitis. Zhonghua Min Guo Wei Sheng Wu Xue Za Zhi, 8(4), 274–279.
Abstract: The host preference of 4 Culex mosquito species collected in Miaoli and Pingtung counties, Taiwan was studied by capillary precipitin method. Antisera to alum-precipitated sera of man, bovine, swine, rabbit, horse, dog, cat, mouse, chicken, duck, and pigeon were produced in rabbits and reacted with 758 mosquito blood meals among which reactions to one or more antisera. Culex annulus and Culex tritaeniorhynchus summorosus showed a great avidity for pig, and Culex fuscocephala for bovine. Culex pipiens fatigans was ornithophilic. None of 110 C. t. summorosus and 2.4% of 223 C. annulus had fed on man. Among 66 samples of C.p. fatigans tested 10.3% had fed on man, while none of 359 C. fuscocephala did. It seems that the latter does not act as a primary vector of Japanese encephalitis.
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Makarov, V. V., & Bakulov, I. A. (1975). [Zoopathogenic arboviruses, their systematics and ecology]. Veterinariia, (11), 39–41.
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Nelson, W. A., Keirans, J. E., Bell, J. F., & Clifford, C. M. (1975). Host-ectoparasite relationships. J Med Entomol, 12(2), 143–166.
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Scherer, W. F., Madalengoitia, J., Flores, W., & Acosta, M. (1975). Ecologic studies of Venezuelan encephalitis virus in Peru during 1970-1971. Am J Epidemiol, 101(4), 347–355.
Abstract: Venezuelan encephalitis (VE) virus has intermittently produced epidemics and equine epizootics on the dry Pacific coastal plain of Peru since at least the 1930's. However, evidence that the virus exists in the Amazon region of Peru to the east of the Andes mountains was not obtained until antibodies were found in human sera collected in 1965, and 10 strains of the virus were isolated in a forest near the city of Iquitos, Peru during February and March 1971. Eight strains came from mosquitoes and two from dead sentinel hamsters. Three hamsters exposed in forests near Iquitos developed VE virus antibodies suggesting that hamster-benign strains also exist there. Antibody tests of equine sera revealed no evidence that VE virus was actively cycling during the late 1950's or 1960's in southern coastal Peru, where equine epizootics had occurred in the 1930's and 1940's. In northern coastal Peru bordering Ecuador, antibodies were present in equine sera, presumably residual from the 1969 outbreak caused by subtype I virus, since neutralizing antibody titers were higher to subtype I virus than to subtypes III or IV. No VE virus was detected in this northern region during the dry season of 1970 by use of sentinel hamsters. The possibility is considered that VE epidemics and equine epizootics on the Pacific coast of Peru are caused by movements of virus in infected vertebrates traversing Andean passes or in infected vertebrates or mosquitoes carried in airplanes from the Amazon region.
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Sudia, W. D., Fernandez, L., Newhouse, V. F., Sanz, R., & Calisher, C. H. (1975). Arbovirus vector ecology studies in Mexico during the 1972 Venezuelan equine encephalitis outbreak. Am J Epidemiol, 101(1), 51–58.
Abstract: Virus vector studies were conducted in the States of Durango, Chihuahua, and Tamaulipas, Mexico, in June and July 1972. Apparently only a low level of Venzuelan equine encephalitis (VEE) virus transmission to equines occured at the time of the study, and the infection was restricted to areas which had not experienced overt activity during the preceding year. The low level of infection was associated with a scarcity of mosquitoes. The IB (epidemic) strain of VEE virus was isolated from two pools of Anopheles pseudopunctipennis (Theo.) and the blood of one symptomatic equine. The low mosquito population, the relatively few equine cases observed, and the absence of reports of VEE human disease from the outbreak area suggested VEE virus persistence through a low-level mosquito-equine transmission cycle. Other studies have already indicated that wild vertebrates play no more than a minor role in outbreaks of epidemic VEE. Mosquito collections made in areas of the states of Durango, Chihuahua, and Tamaulipas, where considerable epidemic activity of VEE had occurred in 1971, failed to reveal evidence of VEE virus persistence. Twenty-nine ioslations of other arboviruses were also made in these studies: including 22 of St. Louis encephalitis virus (SLE), 2 of Flanders virus, 1 of Turlock virus, 1 of Trivittatus virus of the California Group, 1 of western equine encephalitis virus (VEE), and 2 (from Santa Rose) which possibly represent a hitherto unknown virus in the Bunyamwera Group. These are the first reports of SLE virus isolations from mosquitoes in Mexico, and the first demonstration of Trivittatus, VEE Turlock and Flanders viruses in Mexico from any source.
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Mitchell, D., Kirschbaum, E. H., & Perry, R. L. (1975). Effects of neophobia and habituation on the poison-induced avoidance of exteroceptive stimuli in the rat. J Exp Psychol Anim Behav Process, 1(1), 47–55.
Abstract: Two experiments on the role of neophobia in poison-induced aversions to exteroceptive stimuli are reported. In Experiment 1, rats were given either 10 or 25 days of habituation to the test situation prior to conditioning. Those animals with the longer habituation period avoided a complex of novel exteroceptive stimuli while those with the shorter habituation period did not. In Experiment 2 rats initially avoided the more novel of two containers, but gradually came to eat equal amounts from both. A single pairing of toxicosis with consumption from either the novel or the familiar container reinstated the avoidance of the novel container in both cases. The results were discussed in terms of an interaction between habituation and conditioning procedures. It was suggested that previously reported differences between interoceptive and exteroceptive conditioning effects may have been influenced by the differential novelty of the two classes of stimuli in the test situation. It was further suggested that non-contingently poisoned control groups should routinely be included in poison avoidance conditioning studies.
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Sivak, J. G., & Allen, D. B. (1975). An evaluation of the “ramp” retina of the horse eye. Vision Res, 15(12), 1353–1356.
Abstract: Using a rapid freezing and sectioning technique, the distance between the lens and retina of the horse eye was measured. There is no indication of a ramp retina that could serve accommodation. The pupil axis of the eye coincides with the maximum lens to retina distance. The changes in the lens-retina distance are greater below the axis than above it. Calculations were made of refractive power of the horse eye from measurements of curvature and refractive indices of the ocular tissues. These calculations agree both qualitatively and quantitatively with retinoscopic measurements on live horses. Both show that the refractive state shifts in the direction of hyperopia above and below the axis and that this shift is greater below the axis than above it. Some dynamic accommodative ability in the living eye was observed.
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Bayley, P., Martin, S., & Anson, M. (1975). Temperature-jump circular dichroism: observation of chiroptical relaxation processes at millisecond time resolution. Biochem Biophys Res Commun, 66(1), 303–308.
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