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A biostratigraphic survey of 57 Late Ordovician marine shelly invertebrates from the Climacograptus manitoulinensis zone of eastern Canada supports suggestions that throughout the Early Phanerozoic benthic marine speciations occurred preferentially in marginal marine environments. The species subsequently spread onto the craton. There is no obvious positive correlation between the times of first appearance of new associations or novel communities along the continental margin and the first appearance on the craton of the species making up these communities. Taxonomic similarities between marine communities that occupied both marginal and cratonic regimes may reflect a more static local ecology than the evolutionary dynamics of a piecemeal species-by-species reassembly. 相似文献
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Pemphigus foliaceus of the footpads in three dogs 总被引:1,自引:0,他引:1
P J Ihrke A A Stannard A A Ardans C E Griffin A J Kallet 《Journal of the American Veterinary Medical Association》1985,186(1):67-69
Severe hyperkeratinization and villous hypertrophy of the footpads were seen in 3 middle-aged dogs. Peeling, fissuring, swelling, and ulcerations were noted on the margins of severely affected pads. Pain was evident in palpation and ambulation. Lesions were compatible with the traditional diagnosis of "hard pad disease". Histopathologic findings were diagnostic for canine pemphigus foliaceus in all 3 dogs, and direct immunofluorescence in an intercellular pattern was seen in both dogs that were tested. All 3 dogs responded to immunosuppressive dosages of corticosteroids. 相似文献
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Hurtig MB Farrow CS Fretz PB 《The Canadian veterinary journal. La revue veterinaire canadienne》1985,26(6):177-180
The radial carpal and intermediate carpal bones were found to be fused in a four year old Quarterhorse stallion having a subtle forelimb lameness. Clinical examination, diagnostic local anesthesia, radiography and arthroscopy were used to arrive at the diagnosis. A cause could not be established, although perinatal deformation of cartilagenous carpal bone templates is suspected. A similar case of carpal bone fusion was found among carpi collected for an anatomical study, indicating this condition may be more common than expected. Clinicians should carefully evaluate the flexed lateral view of the carpus for proximal movement of the intermediate and ulnar carpal bones in young horses presented for carpal lameness. The significance of this condition will remain uncertain until its incidence and relationship to lameness are better defined. 相似文献
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Evaluation of a Killed Vaccine Against Porcine Pleuropneumonia Due to Haemophilus pleuropneumoniae 总被引:20,自引:2,他引:18
Higgins R Larivière S Mittal KR Martineau GP Rousseau P Cameron J 《The Canadian veterinary journal. La revue veterinaire canadienne》1985,26(2):86-89
A bacterin containing serotypes 1 and 5 of Haemophilus pleuropneumoniae was developed for the prevention and the control of porcine pleuropneumonia. It was injected intramuscularly into three groups of ten piglets, the first group with one dose, the second one with two doses and the third one with three doses at two-week intervals. Another group of ten piglets did not receive the vaccine. All the piglets were then challenged by an aerosol of mixed suspensions of H. pleuropneumoniae serotypes 1 and 5. Two and three injections of vaccine completely prevented mortality, whereas half of the control piglets and of those receiving only one dose of vaccine died. All surviving piglets, both control and vaccinated, had severe signs of respiratory disease for at least 36 hours after exposure to challenge. Moreover, vaccination did not induce the production of antibodies at high titers. Local reactions were not noted after vaccination and at postmortem; ten weeks after the challenge, there were no signs of abscess formation or induration. 相似文献