Population sizes and frequency of staphylococci at mucocutaneous sites on healthy dogs.     

R P Allaker  D H Lloyd  R M Bailey 《The Veterinary record》1992,130(14):303-304

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Development of a computerized systems model for health management decision support in growing hogs     

James W. Lloyd  Stephen B. Harsh  John B. Kaneene  Gerald D. Schwab  Brad J. Thacker  Andrew J. Thulin 《Preventive veterinary medicine》1994,19(3-4):249-265

A study was designed to provide decision support for health management in growing hogs. A dynamic, stochastic systems model for a confinement, continuous production hog growing enterprise (including nursery, grower and finisher phases) was developed to simulate the economic effects of disease, available floor space and feed additives using farm- specific data. Modeling techniques included: discrete and distributed (continuous) delays; triangular probability density functions; autocorrelation; table look-up functions; an alpha-beta tracker; non-linear, constrained optimization. The model was designed to be initialized with the system's current status, using an accompanying production/financial database to achieve individual-farm specificity. Initialization of rate variables required ‘reverse optimization’ of historical system performance. Model predictions are based on an adjustment approach, where changes in current performance are dictated by changes in disease rates, available floor space and feed additive use. These effects vary randomly, but are autocorrelated between production phases, between similar diseases and over time.  相似文献   

Fenvalerate residues in milk following topical treatments to dairy cows     

Richard Frank  Heinz E. Braun  Lloyd A. Miller  George W. Allan 《Pest management science》1984,15(6):600-604

Two mature Holstein cows were treated with 0.1g of fenvalerate each, in six consecutive topical treatments at intervals of 3 or 4 days. Neither of the diastereoisomers of fenvalerate was detected in the milk 6h after the application. After 3 days, the mean fenvalerate residue was 0.46μg litre⁻¹; by day 4, this residue had declined below the detection limit of 0.1μg litre⁻¹ for each of the diastereoisomers. Two Holstein cows were also treated with 0.5g of fenvalerate per cow in three consecutive topical treatments at intervals of 14 days. Residues in whole milk were at a maximum 6h after treatment and declined to less than 0.2μg litre⁻¹ over 21 days. Only 0.03 to 0.06% of the applied fenvalerate appeared in the milk as the intact insecticide.  相似文献   

A method for assessing the relative importance of seabird breeding colonies     

C.S. Lloyd 《Biological conservation》1984,28(2):155-172

Evaluating the importance of seabird breeding colonies in a national or international context is an essential part of conservation planning. A method for assesiing seabird sites, and for selecting a series of key colonies, is described, following Ratcliffe's (1977) guidelines. The present study uses seabirds in the Republic of Ireland and data recently collected for a breeding seabird inventory. The method is suitable for use on seabird populations elsewhere. The inventory listed over 400 sites, of which 133 were identified by this study to be of national importance to conservation. Among these were 11 internationally important colonies. Thirty-one of the colonies were selected as key sites of special importance.  相似文献   

Methicillin-resistant Staphylococcus aureus isolates from companion animals     

Boag A  Loeffler A  Lloyd DH 《The Veterinary record》2004,154(13):411

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Confirmation of reduced toxicity of deoxynivalenol in extrusion-processed corn grits by the MTT bioassay     

Cetin Y  Bullerman LB 《Journal of agricultural and food chemistry》2006,54(5):1949-1955

The objective of this study was to determine the loss of toxicity of deoxynivalenol in extruded cereal-based products by the tetrazolium salt (MTT) bioassay using a sensitive Chinese hamster ovary (CHO-K1) cell line and to compare the results to chemical (high-performance liquid chromatography, HPLC) and biochemical (enzyme-linked immunosorbant assay, ELISA) methods of analysis. A split-split plot design was used for the extrusion process experiments at temperatures of 150, 175, and 200 degrees C and screw speeds of 70 and 140 rpm. The initial mean deoxynivalenol concentration in the corn grits artificially contaminated with Fusarium graminearum was found to be 23.5 mug/g as measured by HPLC. The percent reductions of deoxynivalenol in the contaminated corn grits upon extrusion processing ranged from 22 to 35%, from 21 to 34%, and from 21 to 37% as measured by HPLC, ELISA, and MTT bioassay, respectively. The MTT bioassay results were more closely correlated with HPLC (r = 0.90) results than with ELISA results (r = 0.78). The MTT bioassay, using a sensitive mammalian cell line, was demonstrated to be a useful method for quantification of deoxynivalenol as well as a potential toxicity screening method for contaminated extruded cereal-based products.  相似文献   

Plant science. Microtubules make tracks for cellulose     

Lloyd C 《Science (New York, N.Y.)》2006,312(5779):1482-1483

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Efficient and sensitive method for quantitative analysis of alkaloids in hardinggrass (Phalaris aquatica L.)     

Zhou L  Hopkins AA  Huhman DV  Sumner LW 《Journal of agricultural and food chemistry》2006,54(25):9287-9291

An efficient high-performance thin-layer chromatography (HPTLC) method for the analysis of alkaloids in hardinggrass (Phalaris aquatica L.) was developed. The method employed HPTLC glass plates precoated with silica gel 60F-254 as the stationary phase. The solvent system consisted of ethyl acetate/chloroform/7 N NH4OH in methanol (8:2:1, v/v/v). Using unidimensional double-development, bands were well separated for 10 alkaloid standards as well as alkaloids observed in hardinggrass plant extracts. Identities of compounds observed using HPTLC were validated by high-performance liquid chromatography-mass spectrometry (HPLC-MS). Software was used to quantify individual alkaloids in plant samples based on HPTLC retention factors and intensities relative to standards of known concentration. Correlation coefficients of 0.99 were obtained between estimated and actual concentrations for four standards (methyltyramine, hordenine, gramine, and 5-methoxydimethyltryptamine), with linearity in the range of 120-3840 ng/spot. The HPTLC method is repeatable and specific for beta-carboline, tryptamine, gramine, and tyramine type alkaloids in mixed standard and plant extracts. Initial results indicate substantial variation in alkaloid composition among and within hardinggrass populations.  相似文献   

Total and relative deficiency of gut mucosal IgA in German shepherd dogs demonstrated by faecal analysis     

Littler RM  Batt RM  Lloyd DH 《The Veterinary record》2006,158(10):334-341

The concentration of immunoglobulins in faecal extracts was investigated as a method of assessing the production of immunoglobulins by the gut mucosa of 137 dogs. There were significant correlations between the concentrations in faecal extracts and the concentrations produced in duodenal organ cultures. Seventy-six German shepherd dogs had significantly lower median immunoglobulin A (IgA) concentrations in their faecal extracts than 63 controls of various breeds. Sixteen of the German shepherd dogs had IgA concentrations below the 95 per cent confidence limit of the control population and six had no demonstrable faecal IgA. The faecal concentrations of immunoglobulin G and albumin were significantly higher in the German shepherd dogs than in the controls, but their immunoglobulin M concentrations were similar.  相似文献   

Aerosol delivery of trail pheromone disrupts the foraging of the red imported fire ant,Solenopsis invicta     

David Maxwell Suckling  Lloyd D Stringer  Joshua E Corn  Barry Bunn  Ashraf M El‐Sayed  Robert K Vander Meer 《Pest management science》2012,68(12):1572-1578

BACKGROUND: The fire ant, Solenopsis invicta, is one of the most aggressive and invasive species in the world. The trail pheromone Z,E‐α‐farnesene (91% purity) was prepared, and disruption of worker trail orientation was tested using an ethanol‐based aerosol formulation presenting a single puff of this compound by airbrush and compressed air. Trail‐following behaviour was recorded by overhead webcam and ants digitised before and after presentation of the aerosol treatment at four rates (1.6, 16, 160 and 1600 ng cm^?2). RESULTS: Ants preferred 110 ng cm^?1 over 11, 1.1 and 0.11 ng cm^?1 for trail following. Within seconds of presentation of 1600 ng cm^?2, the highest dose tested, trail disruption was observed. Disruption was evident as reduced arrival success and reduction in the trail integrity statistic (r²), as well as increased deviation from the trail (deg). The distribution of walking track angles was also flattened. CONCLUSIONS: The feasibility of using aerosol for delivery of trail pheromone was demonstrated, but the need for high purity combined with the difficulty of commercial supply makes this technique impractical. However, the commercial production of Z,E‐α‐farnesene of high purity by industrial biotechnology or from (E)‐nerolidol may be possible in future, which would facilitate further development of trail pheromone disruption of S. invicta. Copyright © 2012 Society of Chemical Industry  相似文献