Fumigation as a Means of Eradicating Colorado Beetle in Imports of Potatoes, Grain and Timber     

D.F. POWELL  K.A. MILLS 《EPPO Bulletin》1981,11(3):371-376

Colorado beetle is not indigenous to the United Kingdom, but is often found in imported produce and is a serious pest of potato crops. The efficacy at 10°C of five fumigants was tested against diapausing beetles in the laboratory. Phosphine was the most effective giving 100 % kill in tests with a concentration time product of 6.7 g.h/m³; 100 % kill was also achieved in tests with: methyl bromide at 166 g.h/m³; carbon tetrachloride at 4000 g.h/m3; ethylene dichloride at 6240 g.h/m³; and 1,1,1-trichloroethane at 11600 g.h/m³. A set of practical dosage schedules is given.  相似文献   

The spread of Corynebacterium pseudotuberculosis infection to unvaccinated and vaccinated sheep     

MW PATON  SS SUTHERLAND†  IR ROSE  RA HART†  AR MERCY†  TM ELLIS† 《Australian veterinary journal》1995,72(7):266-269

SUMMARY The decrease in the prevalence of Corynebacterium pseudotuberculosis after two generations of vaccination against the disease it causes, was used to estimate the rate of control of caseous lymphadenitis (CLA). Three groups of 150 sheep, of which 50 in each group were artificially infected with C pseudotuberculosis and 100 in each group were uninfected sheep, were run separately for 40 months and shorn 5 times to promote the spread of CLA. One lot of 50 infected sheep and 2 lots of 100 uninfected sheep were vaccinated against CLA. The rate of spread of CLA was recorded. Sheep vaccinated against CLA and naturally exposed to infection had a 74% lower infection rate than unvaccinated sheep. Sheep vaccinated against CLA and exposed to only vaccinated infected sheep had a 97% lower infection rate. Unvaccinated sheep had a 76% infection rate, with 77% of the transmission occurring at the 4th and 5th shearings, without any discharging CLA abscesses being observed. This study supports the view that in Australian wool producing flocks, CLA spreads mainly from sheep with discharging lung abscesses to sheep with shearing cuts. Vaccinated sheep infected with CLA have 96% fewer lung abscesses compared with unvaccinated infected sheep and are therefore less likely to spread this disease to other sheep .  相似文献   

Fumigation of Field Beans against Ditylenchus dipsaci   总被引：1，自引：1，他引：0  

D. F. POWELL 《Plant pathology》1974,23(3):110-113

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New infection with Corynebacterium pseudotuberculosis reduces wool production   总被引：1，自引：0，他引：1  

MW PATON  IR ROSE  RA HART†  SS SUTHERLAND†  AR MERCY†  TM ELLIS†  JA DHALIWAL‡ 《Australian veterinary journal》1994,71(2):47-49

SUMMARY The effect of natural Corynebacterium pseudotuberculosis infection on wool production and quality in sheep was examined in light of evidence that artificial C pseudotuberculosis infection causes wool production loss. A toxin ELISA was used to identify sheep that had been infected with C pseudo tuberculosis. Greasy and clean fleece weights and fibre diameter were compared in infected and uninfected sheep. C pseudotuberculosis infection caused a 3.8 to 4.8% decrease in greasy wool production and a 4.1 to 6.6% decrease in clean wool production. C pseudotuberculosis infection did not affect fibre diameter. The effects of caseous lymphadenitis (the disease caused by C pseudotuberculosis infection) cause an annual loss of about $17 million in wool production to the Australian wool industry.  相似文献   

A sensitive,inexpensive light meter for photomicrography     

MACHOWICZ P  POWELL EW 《Science (New York, N.Y.)》1954,120(3114):394-395

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In-transit control of Liriomyza trifolii in chrysanthemum cuttings1     

E. A. MORTIMER  D. F. POWELL 《EPPO Bulletin》1985,15(1):23-24

Individual cuttings and leaves of chrysanthemum infested with eggs and larvae of the alien leaf miner Liriomyza trifolii (Burgess) and batches of pupae, were treated in the laboratory in order to find an effective quarantine treatment to control the pest in imported cuttings. Cold treatment for 2 days at 1–2°C followed by methyl bromide fumigation at 15°C with a range of concentration time products (CTPs) was used to obtain accurate dose-response lines and estimate the LD99 and LD99.9 for each stage of the insect. The largest estimates of the LD99 for eggs, larvae and pupae up to 3 days old were less than the CTP specified in the existing (as at September 1983) United Kingdom statutory fumigation treatment designed to prevent the entry of Spodoptera littoralis (Boisd.). This statutory schedule for unrooted cuttings consists of cold storage for 2 days at 1–2°C and then fumigation with methyl bromide at a CTP of not less than 54 g·h/m³ with a minimum treatment period of 4 h at a minimum air temperature of 15°C. Our results indicate that the Spodoptera treatment should give high levels of kill for most stages of L. trifolii provided a CTP of 54 g·h/m³ and a temperature of 15°C (throughout the fumigation) arc achieved uniformly within packs of cuttings when they are fumigated in their transit boxes in commercial practice. The practicality of the technique will depend on whether it is possible to achieve this without causing unacceptable phytotoxicity. The LD99 values for pupae more than 3 days old were greater than those for eggs, larvae and young pupae. Therefore, if this treatment were adopted as a quarantine measure against L. trifolii, good prophylactic treatments and rigorous prc-packing inspections in exporting countries would still need to be maintained, to minimize any risk of importing pupae. The results are presented in full by Mortimer E.A. & Powell, D.F. (1984). Development of a combined cold storage and methyl bromide fumigation treatment to control the American serpentine leaf miner Liriomyza trifolii (Diptera: Agromyzidae) in imported chrysanthemum cuttings. Annals of Applied Biology 105 , (3), 443–454.  相似文献   

The Role of Oestradiol in the Uterine Peristalsis in the Perfused Swine Uterus     

T Maltaris  R Dittrich  W Widjaja  C Sindhuwinata  I Hoffmann  MW Beckmann  A Mueller 《Reproduction in domestic animals》2006,41(6):522-526

This study was designed to examine the effects of oestradiol (E2) on sperm transport in the swine uterus. The bicornuate swine uterus is optimal for the study of the uterine transport and peristalsis because the influence of various factors can be examined on each uterine horn independently. Forty swine uteri (with or without ovarectomy) were perfused for a period of up to 7 h. Two different E2 concentrations (3 or 30 pg/ml) in the perfusion medium were administered for 30 min unilaterally. Through an intracervical catheter 1 ml of a high concentrated dextran blue solution was administered directly in the upper part of the cervix. After bilateral perfusion of the swine uterus with a bolus of 0.3 IU oxytocin the distribution of coloured particles was assessed macroscopically before and after incision of the uterine horns. Coloration was evaluated by two observers blinded to the site-specific administration of E2. In the 10 ovarectomized uteri with the 3 pg/ml E2 concentration a unilateral distribution towards the side of oestradiol administration was observed in six uteri, in four it was a bilateral distribution. In the 10 non-ovarectomized uteri with the 3 pg/ml E2 concentration a uni- and ipsilateral coloration was observed in five uteri, in five it was a bilateral distribution. In the 20 uteri with 30 pg/ml E2, a unilateral coloration of the uterus horns was observed in all uteri. Oestradiol is one of the main factors, which influences the direction of the sperm transport in a dose-dependent manner, in the perfused swine uterus.  相似文献   

Acid pyrophosphate extraction of soil fulvic acids     

J. E. GREGOR  H. K. J. POWELL 《European Journal of Soil Science》1986,37(4):577-585

A simple three step method is described for isolation of soil fulvic acids in high yield. The complexing agent H₂P₂O₇^2? (at pH 2) is used to release soil-bound fulvic acids. Extraction of humic acids is minimal. Selective separation of the protonated fulvic acids from the ionic extractant is achieved on a non-ionic polyacrylate resin (Amberlite XAD-7); after washing the resin, fulvic acids were retrieved in >98% yield by adjusting the pH to 6.5. Two problems associated with the classical alkali extraction method are avoided: possible alkaline oxidation of phenolic components, and their oxidation by Fe³⁺ under the acidic conditions employed to precipitate humic acids. The product typically has an ash weight of <0.6% after one XAD treatment. The method has been applied to three soils and one IHSS peat sample.  相似文献   

Colliding beam fusion reactor     

N Rostoker  MW Binderbauer  HJ Monkhorst 《Science (New York, N.Y.)》1997,278(5342):1419-1422

Recent results with Tokamak experiments provide insights into the problem of magnetic confinement. They demonstrate how to avoid anomalous transport and thus solve the major problems of Tokamak reactors: size, the production of 14-megaelectron volt neutrons, and maintenance. An alternate confinement system, the field-reversed configuration, confines beams of protons and boron-11. For the proton-boron-11 fusion reaction, the fusion products are all charged particles for which direct conversion is feasible and neutron flux is negligible.  相似文献