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1.
Ten isolates of Trichoderma harzianum were tested for their ability to control lettuce seedling damping-off caused by introduced Rhizoctonia solani. T. harzianum isolates TRC 9 and 28 both reduced damping-off. Dual culture experiments were used to select isolates for the study of antibiotic production and mycoparasitism. T. harzianum isolate TRC 12 produced volatile and non-volatile antibiotics, whilst TRC 33 produced only non-volatile antibiotics. T. harzianum isolates 018-2/Y and TRC 9,15 and 28 mycoparasitized R. solani by coiling around and lysing the host hyphae. It appeared that mycoparasitism was more important than antibiosis in the biological control of damping-off. 相似文献
2.
Shoulder Lameness in the Dog 总被引:1,自引:0,他引:1
J. R. CAMPBELL 《The Journal of small animal practice》1968,9(4):189-198
3.
An investigation into the bacterial aetiology of 'black patch necrosis' in Dover sole, Solea solea L. 总被引:2,自引:0,他引:2
Abstract. A recurring disease known as 'black patch necrosis' (BPN) has been the cause of severe mortalities in 0-group and 1-group Dover sole during the period 1974-1978 at the Sea Fish Industry Authority's Marine Cultivation Unit at Hunter-ston, Ayrshire, Scotland. Samples of diseased and healthy Dover sole tissue were examined microbiologically and a long thin filamentous Gram-negative organism, strongly resembling Flexibacter columnar's , was repeatedly isolated from diseased tissue but was not found in healthy tissue. This organism was pathogenic to Dover sole, producing 100% mortality in 96 h at 17.5°C (±2°C) and the organism was reisolated from all the infected fish. The pathogenic isolate and reisolate were examined and compared with reference strain NCMB 1038 of Flexibacter columnarts , formerly known as Chondrococcus columnaris or Cytophaga columnaris. The isolate, reisolate and type culture were identical with respect to cell morphology, oxidase test, catalase production, production of H2 S, casein hydrolysis, gelatin liquefaction, hydrolysis of Tween 20, degradation of tyrosine and starch hydrolysis. All bacterial types showed similar patterns of sensitivity to a range of antibiotics. It is proposed that a Flexibacter columnari's-like organism is associated with the condition in farmed Dover sole known as 'black patch necrosis'. 相似文献
4.
J. FONSECA-MADRIGAL V. KARALAZOS P.J. CAMPBELL J.G. BELL & D.R. TOCHER 《Aquaculture Nutrition》2005,11(4):241-250
This study aimed to investigate the effects of dietary crude palm oil (CPO) on fatty acid metabolism in liver and intestine of rainbow trout. Triplicate groups of rainbow trout for 10 weeks at 13 °C were fed on diets in which CPO replaced fish oil (FO) in a graded manner (0–100%). At the end of the trial, fatty acid compositions of flesh, liver and pyloric caeca were determined and highly unsaturated fatty acid (HUFA) synthesis and fatty acid oxidation were estimated in isolated hepatocytes and caecal enterocytes using [1‐14C]18:3n‐3 as substrate. Growth performance and feed efficiency were unaffected by dietary CPO. Fatty acid compositions of selected tissues reflected the dietary fatty acid composition with increasing CPO resulting in increased proportions of 18:1n‐9 and 18:2n‐6 and decreased proportions of n‐3HUFA, 20:5n‐3 and 22:6n‐3. Palmitic acid, 16:0, was also increased in flesh and pyloric caeca, but not in liver. The capacity of HUFA synthesis from 18:3n‐3 increased by up to threefold in both hepatocytes and enterocytes in response to graded increases in dietary CPO. In contrast, oxidation of 18:3n‐3 was unaffected by dietary CPO in hepatocytes and reduced by high levels of dietary CPO in enterocytes. The results of this study suggest that CPO can be used at least to partially replace FO in diets for rainbow trout in terms of permitting similar growth and feed conversion, and having no major detrimental effects on lipid and fatty acid metabolism, although flesh fatty acid compositions are significantly affected at an inclusion level above 50%, with n‐3HUFA reduced by up to 40%. 相似文献
5.
Abstract. The following extracellular enzymes have been readily detected in the culture filtrates from Aeromonas salmonicida: amylase, phospholipase, lysophospholipase and ribonuclease. Amylase and phospholipase have been partially characterized. Evidence suggests that glycogen may be the natural substrate for amylase, and that the role of the enzyme in natural infection is to digest glycogen present in fish muscle. The secretion of amylase activity is suppressed by the addition of glucose to the growth medium. The amounts of amylase, phospholipase and protease that can be detected in culture filtrates decreases with increase in the growth temperature from 25 to 32°C. This marked decrease in secretion of hydrolytic enzymes occurs although the initial growth rates at 25 and 32°C are similar. Free and membrane associated ribosomes have been isolated from cultures grown at 25 and 32°C. At 32°C there is a smaller proportion of membrane-associated ribosomes and this is consistent with the hypothesis that extracellular enzymes from Aeromonas salmonicida are secreted on membrane-bound polysomes. 相似文献
6.
Clinical and pathological findings of Babesia infection in dogs 总被引:1,自引:0,他引:1
The clinical and pathological findings of Babesia infection in 32 dogs in northern Australia are presented. Eleven different breed types were represented from 6 localities in north Queensland and one locality in northern Western Australia. Twenty three (72%) were males. Babesia-infected dogs were grouped by the degree of haematological disturbance and clinical severity: Acute babesiosis (25/32), all pups with severe haemolytic anaemia; subclinical carriers (5/32) with non-specific malaise, characterised haematologically by a normal erythrogram but marked leucopenia; chronic anaemia, observed in 2 adult dogs. Pups were azotaemic (serum urea greater than 6.6 mmol/l) and had elevated serum bilirubin levels (20.8 to 48.5 mmol/l). Total serum protein was usually within the normal range. Pups that died were also hypoglycaemic and severely hyperkalaemic (K+ greater than 10 mmol/l). Low parasitaemias in routine blood smears complicated diagnosis but smears made from ear or toe capillaries, or after haematocrit concentration, greatly enhanced finding parasitised cells. At necropsy, pallor and jaundice were the most consistent observations. Haemoglobinuric nephrosis, an active reticulo-endothelial system and capillaries packed with large numbers of infected erythrocytes were the main histopathological findings. A combination of imidocarb dipropionate at 5 mg/kg body weight, given intramuscularly, with fluid therapy and blood transfusion was the most successful treatment. 相似文献
7.
8.
The REMI and IMPLAN models are widely used approaches to estimating economic impacts for small regions. However, few benchmarks exist for assessing these estimates. This paper evaluates the relative performance of these models in terms of a given impact: the opening of an automobile assembly plant in central Illinois. Although our results are not conclusive and are limited by our application, we find that in terms of several indirect performance criteria, IMPLAN's outcomes, on balance, are somewhat more plausible than those for REMI. 相似文献
9.
D. J. CAMPBELL 《European Journal of Soil Science》1973,24(2):239-243
A flotation method for the rapid measurement of the wet bulk density of soil clods is described in which the clods are sprayed with a waterproof coating of a resin and then immersed sequentially in liquids of different specific gravity. It is compared with the wax coating method for a selection of soil textures and moisture contents and shown to be ten times as rapid when used to measure wet bulk density with an accuracy of ± 0.05 g cm-8. The flotation method was used to show that, for three contrasting soils, clod wet bulk density is independent of clod size. 相似文献
10.
192 sites covering the main soil types in Northern Ireland were analysed for numbers and effectiveness of clover and Lotus rhizobia, and chemical properties. Peat sites were generally highly acid (pH <5.5) and mineral sites near neutral (pH 5.5–7.8). Clover rhizobia were generally absent from peat sites and present in mineral sites as large populations (> 106 g?1 dry soil). 79% of isolates were effective on T. repens var. Grasslands Huia. Lotus rhizobia were generally absent from peat sites, less often present than clover rhizobia in mineral sites, and as smaller populations. They were mainly effective on L. pedunculatus var. G4705 and were all of the slow-growing type belonging to the genus Bradyrhizobium. Numbers of clover rhizobia were significantly correlated with soil pH, exchangeable Ca, base saturation and Al saturation, but effectiveness of clover rhizobia and numbers of Lotus rhizobia were not correlated with any soil chemical property. 相似文献