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51.
Murray RC Walters J Snart H Dyson S Parkin T 《Veterinary journal (London, England : 1997)》2010,186(2):172-179
Results from a previous study indicated that there are specific arena surface characteristics that are associated with an increased likelihood of lameness in dressage horses. It is important to understand what modifiable arena factors lead to these detrimental surface characteristics. The aim of this study was to describe the use of training surfaces and arenas for United Kingdom dressage horses and to investigate any relationships between arena/surface variables and detrimental surface characteristics. Data from a questionnaire returned by 22.5% of all 11,363 registered members of British Dressage were used for the study. Univariate and multivariable logistic regression models were developed with each of the previously identified surface characteristics as dependent variables. Respondents reported that the majority of arenas were privately owned, sized 20 × 40 m and had a sand and rubber surface. The results indicated that wax-coated and sand and rubber surfaces were associated with less detrimental surface properties than sand, sand and PVC, woodchips or grass. Woodchips were most strongly associated with the detrimental characteristic of slipping, and sand with tripping. The findings indicated that any arena surface should have a base, with limestone the recommended surface, and that crushed concrete was best avoided. This information supported previous studies in racehorses that indicated that surface maintenance is essential, especially when many horses are using an arena daily. Problems were less likely if an arena was privately owned. 相似文献
52.
A world-wide need to use water resources efficiently necessitates more effective approaches to study water and contaminant
transport in soil. This study examined the effectiveness of a multi-receiver electromagnetic induction probe (Geonics EM31-3RT)
and modeling software (EMIGMA) to delineate hydrological regimes at field scale. The site consisted of 20 (15 m × 15 m) tile-drained
plots in Southern Ontario, Canada. Measurements of apparent soil electrical conductivity (ECa) and magnetic susceptibility were obtained using the EM31-3RT in each plot at four distances (0, 2.25, 4.5 and 7.5 m) from
the tile drain, and on three occasions (August 22, 26 and 29) in 2003. The EMIGMA was used to simulate a depth profile of
electrical conductivity (ECs) from EM31-3RT readings. The near-surface soil showed significantly (p < 0.01) smaller ECa values than at greater depth. The ECa measurements made directly over the tile drains were smaller than those observed further away due to the presence of the
drains. Cluster analysis indicated that the largest ECa values were at the lower elevations of the site related to the redistribution of moisture from higher elevations. The effect
of tile drains and rainfall events on ECa was simulated well by EMIGMA, with smaller ECs values above the drains compared to further away, and showing an increase in ECs in the near-surface soil after rain. This study suggests that EM31-3RT measurements combined with EMIGMA simulation of electrical
conductivity can provide valuable information on depth profiles of ECa and water dynamics in soil. 相似文献
53.
DNA- and RNA-derived assessments of fungal community composition in soil amended with sewage sludge rich in cadmium, copper and zinc 总被引:2,自引:0,他引:2
Current UK legislation permits the application of sewage sludge to agricultural land provided concentrations of heavy metals in soil do not increase above maximum permissible limits. However, even within the defined limits, we do not know how an increase in soil heavy metal concentrations is likely to affect biological diversity and activity. Here we report on the effects of sewage sludge addition, including sludge rich in the metals cadmium, copper and zinc, on soil fungal community composition using both an rDNA and rRNA DGGE approach. Sewage sludge addition altered fungal ITS-DGGE banding patterns, however, there were no additional effects of an increase in soil heavy metal concentrations. Similar results were obtained for the full range of copper rich sludge treatments even when copper concentrations were well above the maximum permissible limits. Our data therefore demonstrate that although an increase in soil organic matter content alters soil fungal community diversity and composition, increasing soil concentrations of cadmium, copper and zinc up to current legislative limits had little additional effect regardless of whether rRNA or rDNA was analysed. This suggests that current UK limits for these three heavy metals are within a concentration range that the dominant soil fungi at this field site can tolerate. 相似文献
54.
55.
Reardon RJ Fraser BS Heller J Lischer C Parkin T Bladon BM 《Equine veterinary journal》2008,40(5):508-513
REASONS FOR PERFORMING THE STUDY: There have been no reports of the efficacy of thermocautery of the soft palate (TSP) assessed objectively as a treatment of intermittent dorsal displacement of the soft palate (DDSP). OBJECTIVE: To compare: racing performance of horses that underwent thermocautery of the soft palate with matched controls; and 'Racing Post ratings' (RPR) with prize money won (RE) and a performance index (PI) for each of the horses in the study. HYPOTHESIS: Thermocautery of the soft palate has no beneficial effect on racing performance and the 3 measures of performance are significantly related. METHODS: The inclusion criteria were fulfilled by 110 horses and each was matched with 2 controls. Changes in performance were compared statistically. RPR, RE and PI were analysed using a regression model. RESULTS: The percentage of horses that improved in performance following the procedure was 28-51% for the 3 measures of performance, compared to 21-53% for the matched controls. There was no significant effect of the procedure on the changes in RPR or RE. There was a significant effect of the procedure on the change in PI (P=0.015) with more treated horses achieving an improved PI and fewer acquiring a worse PI than matched control horses. The measures of performance showed significant correlation. CONCLUSIONS: Thermocautery of the soft palate alone may not be the most efficacious treatment of DDSP. POTENTIAL RELEVANCE: Production of a reliable measure of racehorse performance may be possible. 相似文献
56.
57.
A murine hepatoma (Hepa 1c1c7) cellular bioassay was used to guide the isolation of phase II enzyme inducers from fermented soy sauce, using quinone reductase (QR) as a biomarker. A crude ethyl acetate extract, accounting for 8.7% of nonsalt soluble solids of soy sauce, was found to double relative QR specific activity at 25 μg/mL (concentration required to double was defined as a "CD value"). Further silica gel column fractionation yielded 17 fractions, 16 of which exhibited CD values for QR induction of <100 μg/mL. The four most potent fractions were subfractionated by column and preparative thin layer chromatography, leading to the isolation and identification of two phenolic compounds (catechol and daidzein) and two β-carbolines (flazin and perlolyrin), with respective CD values of 8, 35, 42, and 2 μM. Western blots confirmed that the increases in QR activity corresponded to dose-dependent increases in cellular levels of NAD[P]H:quinone oxidoreductase 1 protein by these four QR inducers. To the authors' knowledge, this is the first report on the ability of β-carboline-derived alkaloids to induce phase II enzymes. 相似文献
58.
59.
Valasia Iakovoglou Timothy B. Parkin Richard B. Hall Manjit K. Misra 《Scandinavian Journal of Forest Research》2014,29(5):415-420
Storage of recalcitrant seeds remains an unsolved problem. The study of gaseous atmospheres could provide insights in understanding the metabolism of recalcitrant seeds and their potential in being used as means for storage. This study investigated the metabolism of the recalcitrant Quercus alba seeds when subjected under nitrous oxide (N2O) and air atmospheres. Seeds were placed in sealed atmospheric flasks of 98/2% N2O/O2. Three experiments were conducted to determine N2O uptake in relation to oxygen (O2) and carbon dioxide (CO2) levels. For the first experiment, “non-renewed” closed atmospheric systems with 98/2% N2O/O2 and air were used. Two more experiments were also conducted for the 98/2% N2O/O2 atmosphere to determine how rate of gas renewal (two and seven days) affects the N2O, O2, and CO2 gases quantitatively. Cumulative results on non-renewed flasks with 98/2% N2O/O2 showed that as time progressed, N2O uptake increased with variation in the magnitude of N2O utilization throughout the 37 experimental days, while seeds ceased O2 utilization by the 11th day. However, CO2 levels did not decrease, suggesting a shift toward fermentation processes. Finally, the two experiments for the 98/2% N2O/O2 indicated that the O2 levels did not deplete under a two-day gas renewal, suggesting a frequent gas renewal under low O2 storage conditions. 相似文献
60.
Parkin TD Clegg PD French NP Proudman CJ Riggs CM Singer ER Webbon PM Morgan KL 《Veterinary journal (London, England : 1997)》2006,171(1):157-165
The characteristics of, and pre-existing pathology associated with 75 cases of fatal lateral condylar fracture sustained by Thoroughbreds while racing in the UK were described. Cases were identified from 220 cases of fatal distal limb fracture submitted as part of studies designed to identify risk factors for all fatal distal limb fractures. Fractures were most common in hurdle races and affected the right forelimb twice as often as the left forelimb. Fracture dimensions were similar to previous reports, however there was a much greater prevalence of articular and diaphyseal comminution and of concurrent fractures in the current report. Pre-existing pathology was particularly common in the medial and lateral parasagittal grooves of the distal articular surfaces of the third metacarpus/metatarsus. The degree of this pathology was not associated with horse age, length of career or number of career starts. 相似文献