MALIGNANT PERIPHERAL NERVE SHEATH TUMOR IN A CAT     

Barbara J.  Watrous  Thomas P.  Lipscomb  Jerry R.  Heidel  Lindsay M.  Normal 《Veterinary radiology & ultrasound》1999,40(6):638-640

A report of a cat with a cranial tumor of nerve sheath origin is presented. The cranial mass, with a cyst-like character on presentation to the referring veterinarian suggested a benign lesion, but the clinical course was rapid and indicative of central nervous system involvement. The tumor was poorly differentiated by histologic examination, but immunohistochemistry was consistent with Schwann cell origin. Features of peripheral nerve sheath tumors in cats and other species are briefly discussed.  相似文献   

COMMENT     

Barbara Horsfield 《Australian veterinary journal》1999,77(9):609-609

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VETERINARY AVA membership gives a wide range of benefits     

Barbara Horsfield 《Australian veterinary journal》2000,78(1):59-59

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Experimental deepwater culture of the Sydney rock oyster (Crassostrea commercialis = Saccostrea cucullata): II. Pontoon tray cultivation     

Baughan Wisely  John E. Holliday  Barbara L. Reid 《Aquaculture (Amsterdam, Netherlands)》1979,16(2):141-146

Pontoons made from plastic pipe were tested as an alternative to racks for deepwater culture of the Sydney rock oyster. The growth and mortality of oysters permanently suspended in water on trays beneath floating pontoons were compared with oysters on trays in an intertidal zone. For both culled spat (30–31 g whole oyster weight) and seconds oysters (37–39 g) beneath pontoons the growth rate, measured by weight increases, was three times that of oysters on intertidal racks over a 5-month period. Mortality (from unknown causes) was higher beneath the pontoons. The mean mortality of spat oysters was 40% compared with 24% on the intertidal trays, and for seconds oysters was 51% compared with 34%.  相似文献   

The colonisation by plants of calcareous wastes from the salt and alkali industry in Cheshire,England     

J.A. Lee  Barbara Greenwood 《Biological conservation》1976,10(2):131-149

Calcareous wastes from the salt industry occupy approximately 150ha of land in Cheshire, a county devoid of natural calcareous substrata. The wastes are pumped into lagoons and on drying put become colonised by plants. The resulting lime beds vary in the extent to which they are invaded by plants but a number of areas support rich and varied grassland communities. The Witton lime beds, Northwich, support large populations of a number of species of base-rich habitats, which are uncommon in Cheshire and are of restricted distribution in northwest England as a whole. These include a number of orchid species, of which Dactylorhiza praetermissa and Gymnadenia conopsea are the most abundant. Information analysis was used to analyse the vegetation of Witton lime beds and the vegetation groupings recognised were used to examine possible successional sequences. The edaphic factors limiting growth in lime wastes were examined and the effects of fertilizer additions on the growth of indigenous species at Witton are described. Phosphorus was the major element limiting growth but on older wastes, with a higher unreacted lime content, phosphorus only partially removed the infertility. The findings are discussed in terms of the conservation and management of Witton lime beds to ensure continued floristic diversity and the possible reclamation of other lime waste areas.  相似文献   

A principal components analysis of some biochemical activities in a climosequence of soils     

D.J. Ross  T.W. Speir  D.J. Giltrap  Barbara A. McNeilly  L.F. Molloy 《Soil biology & biochemistry》1975,7(6):349-355

Ten biochemical properties, comprising oxygen uptakes with and without added glucose, dehydrogenase, invertase, amylase. protease, urease, phosphatase, and sulphatase activities, and the invertase/amylase ratio, were measured in a climosequence of nine soils in tussock grasslands in New Zealand. Generally, these properties had no consistent distribution pattern. Some activities, however, were greater in the more developed soils of the sequence while others were lower in the “alpine” soil.The influence of 10 environmental and soil factors on the activities was assessed by principal components analysis. Nearly 90% of the total variance could be accounted for by only three components. The amounts of variance in individual activities accounted for by these components differed, but were usually high. The percentage of organic C, soil moisture regime, and mean annual temperature accounted for much of the variance in all three components; total N was unimportant. As a result of the principal components analysis, the soils could be grouped biochemically into arrangements that were consistent with either the pedological classification of the soils or the influence of a dominant environmental factor. The usefulness of principal components analysis for other ecological studies of soil biochemical properties is indicated.  相似文献   

Connecting phenological predictions with population growth rates for mountain pine beetle,an outbreak insect   总被引：1，自引：0，他引：1  

James A. Powell  Barbara J. Bentz 《Landscape Ecology》2009,24(5):657-672

It is expected that a significant impact of global warming will be disruption of phenology as environmental cues become disassociated from their selective impacts. However there are few, if any, models directly connecting phenology with population growth rates. In this paper we discuss connecting a distributional model describing mountain pine beetle phenology with a model of population success measured using annual growth rates derived from aerially detected counts of infested trees. This model bridges the gap between phenology predictions and population viability/growth rates for mountain pine beetle. The model is parameterized and compared with 8 years of data from a recent outbreak in central Idaho, and is driven using measured tree phloem temperatures from north and south bole aspects and cumulative forest area impacted. A model driven by observed south-side phloem temperatures and that includes a correction for forest area previously infested and killed is most predictive and generates realistic parameter values of mountain pine beetle fecundity and population growth. Given that observed phloem temperatures are not always available, we explore a variety of methods for using daily maximum and minimum ambient temperatures in model predictions.  相似文献   

Modelling multi-species response to landscape dynamics: mosaic cycles support urban biodiversity     

Mira Kattwinkel  Barbara Strauss  Robert Biedermann  Michael Kleyer 《Landscape Ecology》2009,24(7):929-941

The importance of the spatial as well as the temporal structure of habitat patches for urban biodiversity has been recognised, but rarely quantified. In dynamic environments the rate of habitat destruction and recreation (i.e. the landscape turnover rate), the minimum amount of potential habitat, its spatial configuration as well as the environmental conditions determining habitat quality are crucial factors for species occurrence. We analysed species responses to environmental parameters and to the spatio-temporal configuration of urban brownfield habitats in a multi-species approach (37 plant and 43 insect species). Species presence/absence data and soil parameters, site age, vegetation structure and landscape context were recorded by random stratified sampling at 133 study plots in industrial areas in the city of Bremen (Germany). Based on the field data, we predicted species occurrences by species distribution models using a multi-model inference approach. Predicted species communities were driven by successional age both at the scale of a single building lot and at the landscape scale. Minimum average succession time of brownfield habitats required to support all and especially regionally rare species depended on the proportion of available open space; the larger the potential habitat area the faster the acceptable turnover. Most plant, grasshopper, and leafhopper species modelled could be maintained at an intermediate turnover rate (mean age of 10–15 years) and a proportion of open sites of at least 40%. Our modelling approach provides the opportunity of inferring optimal spatio-temporal landscape configurations for urban conservation management from patch scale species-environment relationships. The results indicate that urban planning should incorporate land use dynamics into the management of urban biodiversity. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.  相似文献   

Washing agents from sewage sludge: efficiency of Cd removal from highly contaminated soils and effect on soil organic balance     

Klik  Barbara  Kulikowska  Dorota  Gusiatin  Zygmunt M.  Pasieczna-Patkowska  Sylwia 《Journal of Soils and Sediments》2020,20(1):284-296

Purpose

To compare Cd removal from different soils with three washing agents recovered from sewage sludge (dissolved organic matter (DOM), soluble humic-like substances (HLS), soluble humic substances (SHS)). Also, to investigate how washing with these agents changes soil organic-matter composition (OM).

Materials and methods

Sandy clay loam (S1) and clay (S2) highly contaminated with Cd (300 mg kg^?1) were washed with DOM, HLS, or SHS solutions at various pHs, and with various washing times and washing modes (single or double). Cd distribution and OM composition were determined (including content of humic substances (HS), fulvic fraction (FF), labile humic acids (L-HA), and stable humic acids (S-HA)).

Results and discussion

Cd removal proceeded with pseudo-second-order kinetics. Equilibrium was reached in 30 min (S1) and 60 min (S2). DOM, HLS, and SHS removed 75–82% of Cd from S1, and 80–87% from S2. The most mobile fraction of Cd was removed after one wash. S2 retained more OM, including HS, than S1. Although washing did not change the HA/FF ratio in most variants, washing with DOM and HLS increased the percentage of L-HA in both soils. Washing with SHS increased S-HA content in both soils, but the percent content of S-HA was similar to that in the unwashed soil.

Conclusions

DOM, HLS, and SHS derived from sewage sludge can effectively remediate clay and sandy clay soils highly contaminated with Cd. Washing with an SHS solution can increase the content of the most stable carbon forms (HA), which is beneficial for carbon sequestration in remediated soils.

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Spatial distribution pattern and physical – biological interactions in the larval notothenioid fish assemblages from the Bransfield Strait and adjacent waters          下载免费PDF全文

Mario La Mesa  Gabriele La Mesa  Barbara Catalano  Christopher D. Jones 《Fisheries Oceanography》2016,25(6):624-636

The Bransfield Strait and adjacent waters represent one of the most important areas of larval retention off the Antarctic Peninsula. The species composition of larval fish assemblages has been described in detail in previous surveys carried out in the area, but the role of environmental parameters influencing the spatial distribution of early life stages was poorly known. By applying generalized additive models and multivariate analyses, we evaluated the role of environmental variables in shaping the small‐scale distribution of larval fish and investigated the spatial structure of the larval assemblage. It consisted of a few dominant notothenioid species, such as Champsocephalus gunnari, Lepidonotothen squamifrons, Lepidonotothen larseni, Pleuragramma antarctica and Trematomus scotti, and several other rarely caught species. Sea water temperature, salinity and sampling depth were the most important factors determining the spatial distribution of fish with different relative contributions, together explaining more than 80% of total deviance observed. Species richness was mostly affected by salinity, probably due to the narrow range of salinity preference by the species. Cluster analysis of abundance and presence data identified six and five distinct groups, respectively, each of them with substantial contributions of single or rarely two species. Differences in reproductive strategies of adult populations and spatial distribution of early life stages driven by different larval behaviour in response to environmental factors contribute to maintaining a well‐structured larval fish assemblage, ensuring spatial and food niche partitioning.  相似文献