ASVCP quality assurance guidelines: control of general analytical factors in veterinary laboratories

Owing to lack of governmental regulation of veterinary laboratory performance, veterinarians ideally should demonstrate a commitment to self-monitoring and regulation of laboratory performance from within the profession. In response to member concerns about quality management in veterinary laboratories, the American Society for Veterinary Clinical Pathology (ASVCP) formed a Quality Assurance and Laboratory Standards (QAS) committee in 1996. This committee recently published updated and peer-reviewed Quality Assurance Guidelines on the ASVCP website. The Quality Assurance Guidelines are intended for use by veterinary diagnostic laboratories and veterinary research laboratories that are not covered by the US Food and Drug Administration Good Laboratory Practice standards (Code of Federal Regulations Title 21, Chapter 58). The guidelines have been divided into 3 reports on 1) general analytic factors for veterinary laboratory performance and comparisons, 2) hematology and hemostasis, and 3) clinical chemistry, endocrine assessment, and urinalysis. This report documents recommendations for control of general analytical factors within veterinary clinical laboratories and is based on section 2.1 (Analytical Factors Important In Veterinary Clinical Pathology, General) of the newly revised ASVCP QAS Guidelines. These guidelines are not intended to be all-inclusive; rather, they provide minimum guidelines for quality assurance and quality control for veterinary laboratory testing. It is hoped that these guidelines will provide a basis for laboratories to assess their current practices, determine areas for improvement, and guide continuing professional development and education efforts.     

Motivating factors and facilitating conditions explaining women's participation in co-management of Sri Lankan forests

Among South Asian countries, Sri Lanka has only recently ventured into community management of its forests. This paper focuses on a qualitative exploration of two communities in a rainforest conservation project in Sri Lanka. The high level of women's participation is attributed to motivating factors and facilitating conditions. Obstacles to forest co-management outcomes include reduced forest dependency and top–down decision making. Adaptive implementation strategies compensate for these obstacles by establishing strong networks and structural organizations in forest boundary communities. This suggests that an intervention addressing the actual needs of stakeholders, rather than focusing on perceived problems, would allow for increased participation.     

Characterisation of target-site resistance to ACCase-inhibiting herbicides in the weed Alopecurus myosuroides (black-grass)

Resistance to aryloxyphenoxypropionate (AOPP), cyclohexanedione (CHD) and phenylurea herbicides was determined in UK populations of Alopecurus myosuroides Huds. Two populations (Oxford AA1, Notts. A1) were highly resistant (Resistance indices 13-->1000) to the AOPP and CHD herbicides fenoxaprop, diclofop, fluazifop-P and sethoxydim, but only marginally resistant to the phenylurea, chlorotoluron. Analyses of acetyl coenzyme A carboxylase (ACCase) activity showed that an insensitive ACCase conferred resistance to all the AOPP/CHD herbicides investigated. Another population, Oxford S1, showed no resistance to sethoxydim at the population level, but contained a small proportion of plants (<10%) with an insensitive ACCase. Genetic studies on the Notts A1 and Oxford S1 populations demonstrated that target site resistance conferred by an insensitive ACCase is monogenic, nuclearly inherited with the resistant allele showing complete dominance. Investigations of the molecular basis of resistance in the Notts A1 population showed that sethoxydim resistance in A myosuroides was associated with the substitution of an isoleucine in susceptible with a leucine in resistant plants, which has also been found in three other resistant grass-weed species (Setaria viridis (L) Beauv, Avena fatua L, Lolium rigidum Gaud).     

Amplified esterase genes and their relationship with other insecticide resistance mechanisms in English field populations of the aphid,Myzus persicae (Sulzer)

Myzus persicae samples were collected from populations present on a range of field crops between 1997 and 2000. A combination of biochemical, DNA-based diagnostics and bioassays was used to assess the presence of three insecticide resistance mechanisms: elevated carboxylesterase (E4 or FE4), insensitive acetylcholinesterase and insensitive sodium channels (knockdown resistance, kdr). For the carboxylesterases, both the levels of enzyme and the type of gene present (E4 or FE4) were determined. The results showed that during the time period studied there was a dramatic reduction in the proportion of aphids with very high levels of E4 and an increase in those with lower levels of FE4. There was also a slightly different E4 gene present in a limited number of samples. The change in esterase genes was accompanied by a virtual loss of the insensitive AChE variant and a maintenance of aphids with kdr. The selection pressures and other factors leading to these changes in field populations of M persicae are discussed.