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Mancia A Romano TA Gefroh HA Chapman RW Middleton DL Warr GW Lundqvist ML 《Veterinary immunology and immunopathology》2007,118(3-4):304-309
Immunoglobulin constant region heavy chain genes of the dolphin (Tursiops truncatus) have been described for IgM and IgG but not for IgA. Here, the heavy chain sequence of dolphin IgA has been cloned and sequenced as cDNA. RT-PCR amplification from blood peripheral lymphocytes was carried out using degenerate primers and a single sequence was detected. The inferred heavy chain structure shows conserved features typical of mammalian IgA heavy chains, including three constant (C) regions, a hinge region between constant region domain 1 (C1) and constant region domain 2 (C2), and conserved residues for interaction with the Fc alpha R1 and N-glycosylation sites. Comparisons of the deduced amino acid sequences of the IgA heavy chain for the dolphin and the evolutionarily related artiodactyl species showed high similarity. In cattle and sheep, as in dolphins, a single IgA subclass has been identified. Southern blot analysis as well as genomic PCR confirmed the presence of multiple IGHA sequences suggesting that IGHA pseudogenes may be present in the dolphin genome. 相似文献
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The drainage basin, including the coastal zone, may be seen as a large-scale system of interlinked natural resources and ecosystem services which support human activities on land and in the sea. Social and economic activities in the drainage basin have to be consistent with the hydrological and ecological needs for human well-being. Proper attention must also be paid to the impacts of these factors on ecosystems further downstream. A macro-scale ecosystem approach to a basin has to consider: (1) direct uses of water both instream and after extraction when pollutants may be added to the return flow; and (2) indirect use of water for agriculture and forestry where the river may be depleted as a result of evapotranspiration from land surface, crops and trees. Both uses have repercussions on the quantitative flow and quality of water, which may damage water-based instream ecosystem services. The present paper addresses relationships between different types of human intervention in a drainage basin and their consequences. Two analytical models are introduced: (1) a conceptual model which distinguishes between urban and rural water uses, and their respective tools; and (2) a conceptual model for handling spatially ordered land/water use segments subject to different types of interference. Finally, the present paper comments on the need to develop methodologies for cross-disciplinary dialogue, and for balancing water needs, land use and fishery protection. 相似文献
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Arne Steffenrem Pekka Saranpää Sven-Olof Lundqvist Tore Skrøppa 《Annals of Forest Science》2007,64(8):799-806
Genetic- and environmental variation and correlation patterns were characterized for modulus of elasticity (MOE), modulus of rupture (MOR) and related wood traits: latewood proportion, wood density, spiral grain, microfibril angle and lignin content in five full-sib families of Norway spruce. The families were evaluated on the basis of clearwood specimens from the juvenile -mature wood transition zone of 93 sampled trees at age 30 year from seed. Family-means varied significantly (p < 0.05) for all wood traits studied except lignin content. MOE varied between 7.9–14.1 GPa among trees and 9.4–11.0 GPa among families. MOR varied between 47–87 MPa among trees and 61–71 MPa among families. Families remained significantly different in an analysis of specific MOE (MOE/density) and MOR (MOR/density). Hence, solely relying on wood density as a wood quality trait in tree breeding would not fully yield the potential genetic gain for MOE and MOR. Correlations between wood structural traits and specific MOE and MOR are presented and discussed. 相似文献
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Part-time ectoparasites on small mammals disperse via the habitat, while full-time parasites spread throughout the host population by direct contacts between host animals. It is therefore supposed that the effect of the natural environment is different for the two groups. This was studied as differences between observed and expected prevalence, the percentage of the infested host population, during different environmental conditions. Two possible mechanisms of such an effect were analysed, i.e. a) host selection and its change with host frequency and b) parasite migration and reproduction rates as reflected by the frequency distribution patterns on the hosts. As expected the prevalence of full-time ectoparasites (Anoplura and subfamily Laelapinae) could be predicted on the basis of host species frequencies during different environmental conditions, with the exception of one louse species (Hoplopleura acanthopus), because of its restricted distribution. Prediction was not possible for part-time ectoparasites (subfamily Hameogamasinae). Species of the subfamily Haemogamasinae were more catholic in host selection than species of Anoplura and subfamily Laelapinae. The haemogamasin mites changed host species to a greater extent than did Anoplura and Laelapinae. All haemogamasin mites had short-tailed frequency distribution patterns and all Anoplura and Laelapinae, except Hyperlaelaps microti, had long-tailed frequency distributions. 相似文献
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One-year-old hatchery brown trout, Salmo trutta L., ( n = 16 520) from a sea-run, local brood stock were marked and released (scatter-planted) into the River Laisälven in northern Sweden. Eight different groups were created using Alcian blue and Visible Implant Elastomer tags. Half the fish were kept in small enclosures in four stocking areas for 6 days before release. The other half were released just after transportation. To evaluate the effect of acclimatization on post-stocking performance, the areas were electric fished 2 months later. During the electric fishing survey, a higher number of the acclimatized hatchery fish were recaptured than those released immediately. The growth rate of stocked fish differed significantly between stocking areas and fish held in enclosures grew more than those released directly. The rate of recapture of hatchery fish varied between stocking areas (6.4–17.4%). Movements of juveniles within and between the stocking areas were low, and only 3.6% of the recaptured fish were found in an area not originally stocked. These results showed that acclimatization of fish before release increases the number and size at recapture within a stocking area. 相似文献
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The effects of year, size, sexual maturity and release date on the probability of recapture of tagged Atlantic salmon, Salmo salar L., released from a Swedish hatchery in the Baltic Sea were examined. The probability of recapture varied among years for individuals which were juvenile when released (1988, 13.5%; 1989, 4.4%; 1990, 1.2%) or previously mature males (1988, 1.9%; 1989, 0.5%; 1990, 0.4%). Body size was positively associated with the probability of recapture in each release year for both life-history types. Inter-annual changes in recapture rates were similar for both large and small smolts. There was a significant effect of life-history type on recapture rates in 1988 and 1989, but not in 1990. There was a significant effect of release date on recapture rates in 1988 and 1990, but not in 1989. The maximum recapture rates were associated with different release dates in each year, i.e. 27 May 1988, 6 June 1989 and 21 June 1990. 相似文献
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We tested hypotheses on the effect of growing space and biomechanics on tree growth, using data from two field experiments where Scots pine seedlings had been planted in a fixed but systematically irregular pattern. After 16 or 18 years, respectively, stem diameter was measured at 1.3 m (d1.3) and 0.3 m above ground (d0.3). Total tree height, length and diameter of the crown, and height to crown gravity point were also measured. Analyses were split in two parts: influence of growing space on tree and crown dimensions, and biomechanical influence of the crown on stem diameter. The results showed that crown size was closely related to tree height, and that there was a small but statistically significant effect of growing space on both crown size and shape. The biomechanical model explained about 85% of the variation in stem diameter, but growing space had no influence on this relationship, indicating that the wind load absorbed by a given crown size was not affected by growing space. The results were discussed in relation to future growth modelling and new ways of estimating site productivity. 相似文献