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294 serum samples from five Norwegian reindeer herds were examined for antibodies against Hypoderma tarandi L. The first and second larval instars of H. tarandi were tested as antigens in immunodiffusion tests, passive haemagglutination and an Enzyme-Linked Immunosorbent Assay (ELISA). The latter technique, using first instar antigens, produced the best results. A significant difference (P less than 0.1%) was observed between the antibody value of naive reindeer bred in France and those from infected Norwegian herds. No correlation was observed between the antibody titre and the number of warbles recovered at necropsy from the 294 Norwegian reindeer. 相似文献
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SABINE STÖHR CHANTAL CONAND EMILIE BOISSIN 《Zoological Journal of the Linnean Society》2008,153(3):545-560
The ophiuroid fauna of La Réunion, Indian Ocean, is still incompletely known. We report 13 different species from coral reefs, including five new records and a probably undescribed species of Amphioplus , which increases the number of ophiuroids known from La Réunion to 25. The most important find consists of three individuals of a previously unknown representative of the genus Ophiocanops . Originally placed in Ophiomyxidae, its systematic position has long been debated, with some authors advocating a placement with the otherwise extinct Palaeozoic Oegophiurida, based on the absence of several skeletal characters. The new species, O. multispina sp. nov. , shows intermediate characters between its previously only known congener, O. fugiens , and the ophiomyxid Renetheo felli . The three species appear to represent a line of taxa with progressively reduced skeleton instead of an ancient condition. We propose to transfer Ophiocanops back to the Ophiomyxidae, to synonymize Renetheo with Ophiocanops , and to invalidate the Ophiocanopidae, for which there is no autapomorphy-based support. © 2008 The Linnean Society of London, Zoological Journal of the Linnean Society , 2008, 153 , 545–560. 相似文献
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Inhibition by Interferon Preparations of a Solid Malignant Tumour and Pulmonary Metastases in Mice 总被引:2,自引:0,他引:2
WE have reported the efficacy of exogenous interferon preparations in inhibiting the development of several virus-induced leukaemias of mice. These are the Friend1,2 and Rauscher leukaemias3 as well as the spontaneously appearing lymphoid leukaemia of AKR mice4. Comparable interferon preparations also inhibited the growth of transplantable ascitic tumours (of viral and non-viral origin) and markedly increased the survival of tumour inoculated mice5,6. We thought it would be interesting to determine the effect of interferon on the growth of a solid metastasizing tumour. 相似文献
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CHANTAL HELM GWYNETH WILSON JEREMY MIDGLEY LAURENCE KRUGER E. T. F. WITKOWSKI 《Austral ecology》2011,36(8):964-973
Sclerocarya birrea ssp. caffra (marula), a typical savanna tree, is vulnerable to the effects of fire, herbivory and their combination. This paper investigated the relative importance of these agents of disturbance, at the level of the individual stem, by specifically focusing on the following questions: (i) What is the greatest cause of mortality in adult marula stems in conservation areas with both elephants and fire? (ii) Does fire interact with bark stripping to cause adult stem mortality and if so what is the dominant mechanism? (iii) At what stem diameter are marulas resistant to fire? Field surveys quantified the extent of damage in marula individuals in the Kruger National Park, South Africa, highlighting the high levels of extreme herbivory such as toppling (7%) and pollarding (8%), relative to bark stripping (only 6% with more than 50% of the circumference stripped). In addition to extreme herbivory, the progression from bark stripping through to invasion of the soft, exposed heartwood by wood borers, often facilitated by fire, through to toppling of the weakened stem after successive fires, appears to be the dominant mechanism by which fire interacts with herbivory to cause adult stem death. Bark stripping and fire manipulation experiments indicated that bark stripping failed to increase the vulnerability of stems to fire directly through transport tissue damage. However, the combination of bark stripping and fire reduced the ability of the stem to regrow bark, increasing the vulnerability of the exposed stem to boring insects and future fires. Fire manipulation experiments were used to identify the minimum stem diameter of resistance to fire. Marula resisted stem death when greater than 3.4 cm in basal diameter. This paper emphasizes the importance of both fire and herbivory in the development of woody plant population structure and by extension, the relative proportion of trees and grasses in savanna landscapes. 相似文献
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The adaptive significance of coloration in lagomorphs 总被引:3,自引:0,他引:3
CHANTAL J. STONER OLAF R. P. BININDA-EMONDS TIM CARO 《Biological journal of the Linnean Society. Linnean Society of London》2003,79(2):309-328
Lagomorph pelage coloration was matched to habitat type, geographical region, altitude and behaviour to explore the adaptive significance of coloration patterns in this little-studied order of mammals. Analyses were conducted with and without taking phylogeny into account. The former analyses were based on a weighted, phylogenetic supertree for all extant species of lagomorphs that we constructed using morphological and molecular data from 146 papers in the literature. Although our analyses represent an initial, somewhat crude investigation, several clear trends are evident. First, overall body coloration across lagomorphs tends to match the background as shown for pale and red coloration and perhaps seasonal pelage change. The case for countershading being a method of concealment is far less strong. Second, ear tips appear to have a communicative role since they are conspicuous in many different habitats. Third, hypotheses for tail tips having a communicative role, for extremities being dark for physiological reasons, and for Gloger's rule received only partial support. © 2003 The Linnean Society of London, Biological Journal of the Linnean Society , 2003, 79, 309–328. 相似文献