Burrow building in seabird colonies: a soil-forming process in island ecosystems   总被引：2，自引：0，他引：2  

Wesley J. Bancroft  Mark J. Garkaklis  J. Dale Roberts 《Pedobiologia》2005,49(2):149-165

Soil modification via biopedturbation by burrow-building seabirds was examined in a Mediterranean, island ecosystem. Physical and chemical soil properties were compared between a colony of Wedge-tailed Shearwaters (Puffinus pacificus) and adjacent heath across a 14-month period. When compared to heath soil, the biopedturbated soil was 28% drier (6.04±5.40 vol%), had increased bulk density (by 29% to 1.30±0.11 g cm⁻³, 51% porosity), wetting capacity (by 83% to 0.55±0.83 molarity of ethanol droplet), hydraulic conductivity (by 266% to 398.91±252.04 mm h⁻¹), and a greater range in soil surface temperature (31.7±6.2 °C diurnally to 18.3±3.2 °C nocturnally). Soil penetration resistance was reduced by 26% at a depth of 0–100 mm (326.5±122.4 kPa) and by 55% at 500–600 mm (1116.8±465.0 kPa). Colony soil also had increased levels of nitrate (by 470%), phosphorous (118%), ammonium (102%), sulphur (69%), and potassium (34%), decreased levels of iron (by 50%) and organic carbon (61%), was more alkaline, and had a 78% greater conductivity. Shearwaters deposited guano at a rate of 234.4 kg ha⁻¹ yr⁻¹ (dry mass). Chemical analysis of guano equated this to 50.9, 5.7, 5.5, and 3.6 kg ha⁻¹ yr⁻¹ of nitrogen, potassium, sulphur, and phosphorous, respectively. Experimentally constructed burrows demonstrated that digging alone can alter physical and chemical soil factors, but that changes in the nutrient profile of colony soils are predominantly guano-driven. We argue that the physical impact of seabirds on soil should not be overlooked as a soil-forming and ecosystem-shaping factor in island ecosystems, and that biopedturbation can exert major bottom-up influences on insular plant and animal communities.  相似文献   

Letters to the Editor ◆ Lettres À La Rédaction: Dr. Mark Lawrence          下载免费PDF全文

Dale M. Paley 《The Canadian veterinary journal. La revue veterinaire canadienne》2001,42(4):255

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Implications of biotechnology, risk assessment, and communications for the safety of foods of animal origin.     

G R Acuff  R A Albanese  C A Batt  D L Berndt  F M Byers  B E Dale  J H Denton  R L Fuchs  B Gastel  N D Heidelbaugh 《Journal of the American Veterinary Medical Association》1991,199(12):1714-1721

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Fertility-mycorrhizal-isolate interactions in production of containerized pin oak seedlings     

Dale M. Maronek  James W. Hendrix  Cathy D. Stevens 《Scientia Horticulturae》1981,15(3):283-289

Slow-release fertilizer rates (0, 1.1 and 4.5 kg/m³ of 14 N-6 P-11.6 K Osmocote) and isolates of the ectomycorrhizal fungus Pisolithus tinctorius (Pers.) Coker and Couch affected growth and mycorrhizal development on pin oak (Quercus palustris Meunchh.) seedlings. Mycorrhizae developed on all inoculated seedlings after 8 weeks regardless of fertility regime. Through the first 14 weeks, the best mycorrhizal development occurred on all inoculated seedlings fertilized at the lower fertilizer rate. The higher fertilizer rate delayed mycorrhizal development. However, after 18 weeks there were no significant differences in mycorrhizae on inoculated seedlings receiving fertilizer. Inoculated, non-fertilized seedlings had significantly less mycorrhizae than fertilized seedlings throughout the experiment. Only one isolate increased seedling growth, and only at the higher fertilizer rate. No differences in plant height were found among non-inoculated control and inoculated seedlings at the low fertilizer rate.  相似文献   

Liquoid-induced disseminated intravascular coagulation in the blue fox     

B Lium  J Dale  A O Aasen 《Acta veterinaria Scandinavica》1982,23(4):570-580

The present experiments were performed to study the effects of a single high intravenous dose of Liquoid (10 mg/kg body weight) upon platelets, coagulation activities and hematocrit in blue foxes, and their correlation with the survival time. Both “short-living” (< 9 h) and “long-living” (24 h or more) blue foxes showed a marked consumption of coagulation factors, initial fall in fibrinogen, positive ethanol gel test and a gradual decrease in platelet counts. In addition “short-living” animals developed a marked rise in hematocrit, reflecting a considerable increase in vascular permeability. We conclude that activation of plasma proteases has as one of its effects increased permeability in microvasculatory vessels and that this may play a central role for the course and outcome of Liquoid-induced disseminated intravascular coagulation.  相似文献   

Effect of Ampicillin on E. Coli of Swine Origin   总被引：1，自引：1，他引：0       下载免费PDF全文

S. L. Chopra  D. G. Dale    A. G. Blackwood 《Canadian journal of veterinary research》1963,27(9):223-227

The in vitro susceptibility of 103 cultures of E. coli isolated from scouring and nonscouring pigs, and four cultures of Salmonella isolated from a case of necrotic enteritis was tested against Ampicillin contained in nutrient broth at concentrations of 0, 0.1, 1.0 and 5.0 uG per ml. of the medium. All but three cultures of E. coli were found to be susceptible to 5.0 uG/ml., all Salmonella isolates were also susceptible to this concentration of the antibiotic. Susceptibility of E. coli was also tested by plating dilutions of fecal samples obtained from either a scouring or a nonscouring pig, with E.M.B. agar containing 0, 0.1, 1.0, 2.5, 5.0 and 10.0 uG Ampicillin per ml. of the medium. No difference in the growth of E. coli was observed at 0, 0.1 and 1.0 uG concentrations. The three higher concentrations of the antibiotic inhibited the growth of E. coli proportional to the amount of Ampicillin in each concentration.

Ampicillin proved very effective in alleviating the symptoms of hemorrhagic enteritis in a 11-week old pig. The disappearance of scours was associated with the replacement of the previously existing sero-biotypes of fecal E. coliwith another aberrant type of E.coli which produced H₂S. No Ampicillin resistant strains of E. coli emerged following treatment of the animal with this antibiotic.

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The Effect of Selenium Treatment on the Weight Gains of Lambs          下载免费PDF全文

D. G. Dale  L. E. Lloyd    J. E. Moxley 《Canadian journal of veterinary research》1962,26(5):103-106

Two trials were conducted with lambs to evaluate the growth promoting effects of selenium administered orally at a level of 5 mg per month during the pasture season.

No statistically significant effect on weight gains was found to be attributable to selenium administration in either the single lamb or the twin lamb experiment. In both trials there was a trend in the data that suggested a deleterious effect of selenium on weight gains.

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Delayed-type skin hypersensitivity and in vitro lymphocyte immunostimulation responses of swine following inoculation with Mycobacterium avium cell walls and a mycobacterial immunopotentiating glycolipid     

Harland W. Renshaw  John W. Gessner  Lynn F. Woodard  Dale O. Everson 《Veterinary microbiology》1983,8(3):281-291

Miniature swine (n = 5 per group) were inoculated intradermally with mineral oil-in-water emulsions containing either 150 μg of mycobacterial immunopotentiating glyco-lipid P3 (EP3), 150 μg of lyophilized Mycobacterium avium (serotype 8) cell walls (E-MaCW), or 150 μg P3 and 150 μg M. avium cell walls (EP3-MaCW). Swine vaccinated with E-MaCW and EP3-MaCW developed antigen-sensitive lymphocytes detectable with delayed-type hypersensitivity (DTH) skin tests and lymphocyte transformation assay. Swine injected with EP3 were not sensitized. In general EP3-MaCW evoked a more pronounced in vivo DTH tuberculin skin test and in vitro lymphocyte transformation responses than E-MaCW. Time-course studies indicated a more persistent response in swine injected with EP3-MaCW than in those given E-MaCW. Commercial type Yorkshire swine (n = 5) inoculated intradermally with EP3-MaCW developed cell-mediated immune (CMI) responses to avian tuberculin detectable in vivo with delayed-type skin hypersensitivity and in vitro with lymphocyte immunostimulation responses.  相似文献   

Imidazolinone-tolerant crops: history, current status and future   总被引：15，自引：0，他引：15  

Tan S  Evans RR  Dahmer ML  Singh BK  Shaner DL 《Pest management science》2005,61(3):246-257

Imidazolinone herbicides, which include imazapyr, imazapic, imazethapyr, imazamox, imazamethabenz and imazaquin, control weeds by inhibiting the enzyme acetohydroxyacid synthase (AHAS), also called acetolactate synthase (ALS). AHAS is a critical enzyme for the biosynthesis of branched-chain amino acids in plants. Several variant AHAS genes conferring imidazolinone tolerance were discovered in plants through mutagenesis and selection, and were used to create imidazolinone-tolerant maize (Zea mays L), wheat (Triticum aestivum L), rice (Oryza sativa L), oilseed rape (Brassica napus L) and sunflower (Helianthus annuus L). These crops were developed using conventional breeding methods and commercialized as Clearfield* crops from 1992 to the present. Imidazolinone herbicides control a broad spectrum of grass and broadleaf weeds in imidazolinone-tolerant crops, including weeds that are closely related to the crop itself and some key parasitic weeds. Imidazolinone-tolerant crops may also prevent rotational crop injury and injury caused by interaction between AHAS-inhibiting herbicides and insecticides. A single target-site mutation in the AHAS gene may confer tolerance to AHAS-inhibiting herbicides, so that it is technically possible to develop the imidazolinone-tolerance trait in many crops. Activities are currently directed toward the continued improvement of imidazolinone tolerance and development of new Clearfield* crops. Management of herbicide-resistant weeds and gene flow from crops to weeds are issues that must be considered with the development of any herbicide-resistant crop. Thus extensive stewardship programs have been developed to address these issues for Clearfield* crops.  相似文献   

Strongyloidiasis In A Dog          下载免费PDF全文

D. G. Dale 《Canadian journal of veterinary research》1954,18(4):138-140

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