Comparison of tracheal aspirates before and after high-speed treadmill exercise in racehorses

OBJECTIVE: To determine whether percentages of neutrophils in tracheal aspirate (TA) samples collected from racehorses are increased after exercise and whether interpretation of results from TA samples taken before and after exercise agree. DESIGN: Case series of 40 young Thoroughbred and Standardbred racehorses in race training presented for evaluation of poor performance. PROCEDURE: TA samples were collected endoscopically from racehorses presented for poor performance 24 h before and 1 to 2 h after high speed treadmill exercise testing. Aliquots of the retrieved fluid were cytocentrifuged and smears were stained with Diff-Quik. Mean neutrophil counts were expressed as percentages of the total number of inflammatory cells counted and subsequently were categorised as either above or below an accepted cut-off of 20%. Comparisons between percentages of neutrophils before and after exercise were made. RESULTS: Percentage of neutrophils from TA samples obtained from racehorses after exercise was significantly higher than neutrophil percentages from TA samples collected from the same horse before exercise. In horses with TA specimens that were categorised as having < or = 20% neutrophils before treadmill exercise, the percentage of neutrophils in their TA specimens after exercise was, on average, significantly higher and was greater than the cut-off value of 20%. CONCLUSION: Recent strenuous exercise may change the proportion of neutrophils in lower airways of racehorses and practitioners should be aware of this when collecting and interpreting the results from TA samples. The most practical time for collection of a TA sample to obtain the most diagnostically useful information might be after a suitable washout period of at least 1 to 2 h post-exercise.     

The potential of mini-ridging for controlling intrarow weeds: estimating minimum lethal burial depth

Weed management using synthetic herbicides is undergoing a global decline, necessitating a re-evaluation of existing control measures and the development of novel weed management tools. ‘Mini-ridging’ is a non-discriminatory, physical weeding method that functions by burying weeds in the intrarow with a laterally shifted ridge of soil. In glasshouse trials using potted plants, we found that plant recovery after soil application was influenced by plant size, which in turn was influenced by plant species, developmental stage and/or age. The likelihood of plant recovery after soil application was negatively related to the depth of soil applied: very few plants survived total coverage by soil but, conversely, survival could be substantial if some parts of the plants were not covered. The results suggest that burial under a depth of 6 cm of soil would eliminate most plants regardless of species or growth stage. Larger plants would require the application of a greater total depth of soil to achieve this 6 cm of soil cover, and weed management would, therefore, tend to be more successful and more practical if weeds were targeted when still small. This research demonstrates the potential of plant burial as a simple and reliable means of non-chemical weed management, and re-emphasises that, for weed control to be effective, the applied soil layer must cover the whole plant.     

Rhynchosporium leaf scald disease incidence: seed source and spatial pattern

A programme of field trials for the study of the winter barley–Rhynchosporium commune pathosystem is reported. The associated seedborne disease rhynchosporium leaf scald is regarded as having an important impact on barley yields. The analysis in this study relates to the impact of the seed source (commercial or farm-saved seed) on disease incidence and to the spatial pattern of rhynchosporium leaf scald disease incidence. Disease incidence data were calculated from field data recorded as disease severity. Mean disease incidence was higher in the crops grown from farm-saved seed than in those grown from commercial seed, although great agronomic significance cannot be attached to this result. The spatial pattern of rhynchosporium leaf scald disease incidence was characterized in terms of the binary power law (BPL) and was indicative of an aggregated pattern. Programme-wide BPL results were described using a novel phytopathological application of a random coefficients model. These results have application in field sampling for rhynchosporium leaf scald disease.     

The DAWGPAWS pipeline for the annotation of genes and transposable elements in plant genomes

Background  

High quality annotation of the genes and transposable elements in complex genomes requires a human-curated integration of multiple sources of computational evidence. These evidences include results from a diversity of ab initio prediction programs as well as homology-based searches. Most of these programs operate on a single contiguous sequence at a time, and the results are generated in a diverse array of readable formats that must be translated to a standardized file format. These translated results must then be concatenated into a single source, and then presented in an integrated form for human curation.     

Radiographic evaluation of the Zurich cementless total hip acetabular component

OBJECTIVE: To radiographically evaluate the Zurich cementless total hip (ZCTH) cup and correlate lucency with clinical signs of implant instability, time since surgery, and implant generation, using zonal analysis. STUDY DESIGN: Retrospective study. ANIMALS: Client-owned dogs (n = 53). METHODS: Radiographs of dogs that had ZCTH arthroplasty (>1 year) were evaluated using zonal analysis, for lucency surrounding the cup-bone interface (number of zones, length, area). Dogs were examined for clinical signs of implant instability (lameness, hip pain). Lucency was correlated with lameness, time after surgery, and implant generation. RESULTS: Radiographs of 68 implants (18 generation I, 50 generation II) were evaluated. Eight dogs were lame (11.8%). Dogs with lameness were more likely to have lucency in > or =2 zones of analysis (per view), have >2 times the average curvilinear length of lucency, and have >4 times the average area of lucency surrounding the implant compared with non-lame dogs. A weak relationship was observed between time after surgery and implant generation; however, there was no relationship between time after surgery and lucency. CONCLUSIONS: Dogs with lameness after ZCTH arthroplasty were more likely to have lucency at the cup-bone interface. Lucency was better evaluated by radiographic projection than zonal analysis. Temporal progression of lucency was weakly correlated with implant generation. CLINICAL RELEVANCE: Dogs with lucency in > or =2 zones of analysis should be evaluated more frequently for clinical signs of implant loosening. Further investigation of serial radiographs after ZCTH arthroplasty is warranted.     

Book review

Poultry Health and Management: Chickens, Ducks, Turkeys, Geese, Quail, 3rd edn. By David Sainsbury, 1992. 214 pp., illustrated. Oxford, Blackwell Scientific Publications. £17.99. ISBN 0–632–03325–8.