Thyroid-stimulating hormone and total thyroxine concentrations in euthyroid, sick euthyroid and hypothyroid dogs

Canine thyroid-stimulating hormone (cTSH) was measured in a variety of clinical cases (n= 72). The cases were classified as euthyroid, sick euthyroid, hypothyroid or hypothyroid on non-thyroidal therapy on the basis of their history, clinical signs, laboratory results (including total thyroxine concentrations and, where indicated, thyroid-releasing hormone [TRH] stimulation tests) and response to appropriate therapy. Additional samples were taken during some of the TRH stimulation tests to measure the response of cTSH concentrations following TRH administration. A reference range (0 to 0–41 ng/ml) was calculated from the basal concentrations of cTSH in a group of 41 euthyroid dogs. Six of nine cases of confirmed hypothyroidism had basal cTSH concentrations above the reference range, whereas the remainder were within the normal range. One of these three remaining cases was a pituitary dwarf and did not show a rise in cTSH concentration following TRH stimulation. In contrast, only one of a group of six hypothyroid dogs that had been on non-thyroidal treatment within the previous four weeks had increased concentrations of basal cTSH. This study also found that five of a group of 16 dogs with sick euthyroid syndrome had increased cTSH concentrations. It was concluded that cTSH measurements are a useful additional diagnostic test in cases of suspected hypothyroidism in dogs but that dynamic testing is still required to confirm the diagnosis of hypothyroidism.     

Impeded drainage stimulates extracellular phenol oxidase activity in riparian peat cores

Peat drainage, a common land‐use practice in Europe, has been associated with habitat degradation and increased particulate and dissolved carbon release. In the UK, peatland drain blockage has been encouraged in recent years as a management practice to preserve peatland habitats and to reduce fluvial carbon loss and municipal water discoloration. Drain blockage has, however, been found to increase drain‐water dissolved organic carbon (DOC) concentrations and coloration in the short term. In order to investigate the contribution of changes in extracellular phenol oxidase activity to the increase in water coloration following peatland drain blockage, cores collected from a riparian peatland in North Wales were incubated under impeded drainage conditions. Impeded drainage resulted in the stimulation of peat extracellular phenol oxidase activity and heightened soluble phenolic concentrations, suggesting that changes in extracellular phenol oxidase activity may be a key driver of increases in DOC and water coloration following peatland drain blockage. An increase in peat pH with impeded drainage was also observed that may have contributed to the heightened soluble phenolic concentrations – directly (through effects on solubility) and/or indirectly as a driver of the elevated extracellular phenol oxidase activity.     

COMPARATIVE EVALUATION OF AN ULTRAVIOLET AND AN ORTHOCHROMATIC RARE-EARTH IMAGING SYSTEM FOR VETERINARY RADIOGRAPHY

The relative quality and speed of a new ultraviolet-emitting screen, ultraviolet-sensitive film rare-earth system (DuPont Ultra-Vision®) was compared to an orthochromatic rare-earth system (Kodak Lanex®) in a clinical trial. Seven different sets of radiographs of a human foot phantom, or actual canine anatomical structures (tarsus, pelvis, skull, chest, abdomen) were evaluated independently by radiologists, radiology residents and technicians who were unaware of the screen/film combinations used. The 400-speed, Ultra-Vision® Rapid/UVG screen/film combination produced supervisor image detail compared to blue/green emitting 400 and 200-speed screen/film combinations. The image detail of the Ultra-Vision® Rapid/UVG system was nearly equivalent to that produced using a 100-speed, fine-detail blue/green emitting screen/film combination. A 200-speed Ultra-Vision® system was also tested and produced thoracic and abdominal radiographs of equivalent to slightly supervisor quality than those produced using blue/green emitting system.     

Spatial and temporal analysis of wheat bulb fly (Delia coarctata,Fallén) oviposition: consequences for pest population monitoring

Journal of Pest Science - The soil dwelling larvae of the wheat bulb fly (Delia coarctata, Fallén) can cause damage to a number of cereal crops. Monitoring of the oviposition of this pest is...     

Does agricultural intensification cause tipping points in ecosystem services?

Landscape Ecology - Agricultural intensification is being widely pursued as a policy option to improve food security and human development. Yet, there is a need to understand the impact of...     

Evidence of a crossability barrier in diploid x hexaploid and diploid x octoploid crosses in the genus Fragaria

Summary A large number of diploid x hexaploid and diploid x octoploid crosses have been made by numerous workers with poor results. Crosses between synthetic tetraploids and species of higher levels of ploidy were successful. The success of these crosses and the high incidence of pentaploid progeny obtained by other workers from successful diploid x hexaploid crosses indicates that chromosomal or genetic imbalance in the endosperm or between zygote and endosperm is most likely the cause of failure to produce viable plants from 2x x 6x and 2x x 8x crosses.     

Alternative methods of interpreting measurements of resistance to the leafhopper Empoasca kraemeri Ross and Moore in the common bean,Phaseolus vulgaris L.

Summary Appropriate definitions of, and methods of measuring, resistance are sought using Phaseolus vulgaris, a major source of protein in Latin America, and its most important pest, Empoasca kraemeri. The concepts of general vigour and narrow-sense resistance are defined: these two components make up broad-sense resistance. The validity of these definitions, which depend on the inclusion of tolerance as a resistance mechanism, is discussed. In order to distinguish the components, 38 genotypes of P. vulgaris were grown with and without insecticidal proctection, in three replications in a split-plot design, with three planting dates. Seed yield per plant, and a visual score of damage symptoms or vigour, were measured. Three methods of estimating narrow sense resistance are considered: 1) the genotype × insecticide interaction effect in a split-plots analysis, 2) the yield of each genotype unprotected (Y_u) divided by its yield protected (Y_p). and 3) the deviation of each genotype from a regression of Y_u on Y_p. The third method overcomes some objections to the first two, and can be applied to damage and vigour scores as well as to yields. The 38 genotypes differed in narrow-sense resistance according to all three methods, and it appears that in practice Methods 2 and 3 were both valid. They also differed in general vigour. Breeders working with many pests and crops have found that low damage and high yield in the presence of the pest are effective selection criteria. The work reported here supports this view.