Further development of equipment to measure nociceptive thresholds in large animals

Existing methods of assessing pain and analgesia in large animals leave much to be desired. Equipment capable of measuring pain thresholds to a gradually increasing mechanical stimulus was developed. The device was pneumatically powered and controlled by a computer. It was used to assess pain thresholds in sheep, thoroughbred horses and human volunteers. All three species had very similar thresholds, about 5 N. The distribution of thresholds in both healthy and lame sheep was normal; the mean threshold in lame sheep was slightly but significantly lower than that in healthy sheep. Injection of saline had no effect on thresholds over six hours, but the analgesic detomidine significantly raised thresholds in both sheep and horses. The device was able to differentiate analgesia and sedation however, as acepromazine did not raise the thresholds of either species. The equipment proved robust and simple to use.     

The inhibitory effect of bovine rumen fluid on Salmonella typhimurium.

The possible fate of Salmonella typhimurium in the rumen was investigated by monitoring rumen volatile fatty acids (VFA), lactate concentrations and pH over periods which included regular feeding and 48 h starvation. Preparations were made containing 50 per cent rumen fluid from the cow or VFA solutions, and then inoculated with S typhimurium. Viable counts before and after incubation for 24 h at 37 degrees C were compared. Incubation in broths with high concentrations of VFA and low pH resulted in a marked decrease in salmonella numbers, while lower VFA concentrations had little or no inhibitory effect on growth.     

Effects of spreading species‐rich green hay on the botanical composition of an agriculturally improved hay meadow in northern England

The technique of enhancing species diversity by spreading species‐rich green hay following turf scarification was tested in a semi‐improved meadow site in Cumbria, UK. Botanical assessments were carried out in May 2008 (prior to treatment), May and October 2009, and May 2010. Both total species‐richness (number of species per m²) and the richness and aggregate cover of positive indicator species were enhanced by hay spreading, with an average of 21·8 species per m² compared with 17·0–18·7 species per m² for other treatments by May 2010. Significant increases in all three variables occurred by May 2009, with even greater increases between this assessment and May 2010. Hay spreading introduced seven new species, most of which subsequently increased over time, and enhanced the frequency of a further seven. All these species together accounted for only about 5% of vegetation cover in 2010, but the level of species‐richness achieved was equivalent to that of good quality semi‐improved grassland and also equivalent to that achieved in studies where the technique was developed. Results are discussed in detail in relation to the seeding phenology of species at the donor site, as are other factors affecting the technique's potential and possible means of enhancing it.     

The impact of boreal forest fire on climate warming

We report measurements and analysis of a boreal forest fire, integrating the effects of greenhouse gases, aerosols, black carbon deposition on snow and sea ice, and postfire changes in surface albedo. The net effect of all agents was to increase radiative forcing during the first year (34 +/- 31 Watts per square meter of burned area), but to decrease radiative forcing when averaged over an 80-year fire cycle (-2.3 +/- 2.2 Watts per square meter) because multidecadal increases in surface albedo had a larger impact than fire-emitted greenhouse gases. This result implies that future increases in boreal fire may not accelerate climate warming.     

New predators for biocontrol under glass

Several species ofOrius are under investigation in the UK, Europe and North America for the biological control of thrips, especially western flower thrips(Frankliniella occidentalis). The available species are briefly compared and findings on effectiveness and oviposition ofO. laevigatus are reported.     

Pharmacokinetics and therapeutic efficacy of rimantadine in horses experimentally infected with influenza virus A2.

OBJECTIVE: To determine pharmacokinetics of single and multiple doses of rimantadine hydrochloride in horses and to evaluate prophylactic efficacy of rimantadine in influenza virus-infected horses. ANIMALS: 5 clinically normal horses and 8 horses seronegative to influenza A. PROCEDURE: Horses were given rimantadine (7 mg/kg of body weight, i.v., once; 15 mg/kg, p.o., once; 30 mg/kg, p.o., once; and 30 mg/kg, p.o., q 12 h for 4 days) to determine disposition kinetics. Efficacy in induced infections was determined in horses seronegative to influenza virus A2. Rimantadine was administered (30 mg/kg, p.o., q 12 h for 7 days) beginning 12 hours before challenge-exposure to the virus. RESULTS: Estimated mean peak plasma concentration of rimantadine after i.v. administration was 2.0 micrograms/ml, volume of distribution (mean +/- SD) at steady-state (Vdss) was 7.1 +/- 1.7 L/kg, plasma clearance after i.v. administration was 51 +/- 7 ml/min/kg, and beta-phase half-life was 2.0 +/- 0.4 hours. Oral administration of 15 mg of rimantadine/kg yielded peak plasma concentrations of < 50 ng/ml after 3 hours; a single oral administration of 30 mg/kg yielded mean peak plasma concentrations of 500 ng/ml with mean bioavailability (F) of 25%, beta-phase half-life of 2.2 +/- 0.3 hours, and clearance of 340 +/- 255 ml/min/kg. Multiple doses of rimantadine provided steady-state concentrations in plasma with peak and trough concentrations (mean +/- SEM) of 811 +/- 97 and 161 +/- 12 ng/ml, respectively. Rimantadine used prophylactically for induced influenza virus A2 infection was associated with significant decreases in rectal temperature and lung sounds. CONCLUSIONS AND CLINICAL RELEVANCE: Oral administration of rimantadine to horses can safely ameliorate clinical signs of influenza virus infection.