Genetic analysis of Lolium. I. Identification of linkage groups and the establishment of a genetic map

A genetic map of Lolium has been produced using isozyme, restriction fragment length polymorphism (RFLP) and random amplified polymorphic DNA (RAPD) markers applied to a segregating family derived from an F₁ hybrid plant of L. perenne × L. multiflorum provenance, crossed on to a doubled haploid L. perenne. A total of 106 markers, out of a total of 160 polymorphic loci analysed, have been ascribed to seven linkage groups covering a map distance of 692cM, Two of these groups may be allocated to chromosomes 2 and 6 of the Lolium genome. The remaining unallocated markers, the majority of which showed severe segregation distortion, could be associated into small groups of two or three markers which showed no linkage with the main groups at a LOD of 2.8 or, if associated, could not be mapped in a satisfactory manner. This high incidence of disturbed segregations could be accounted for by the use of an interspecific hybrid between two species of differing genome size, with consequent cytological imbalance.     

Double-stocking for overcoming damage to conifer seedlings by pocket gophers

A 5-yr study was conducted on national forests in Idaho and Oregon to evaluate how doubling the seedling stocking rate of lodgepole pine (Pinus contorta) would relate to 5-year survival and the uniformity of distribution of seedlings in the presence of northern pocket gopher (Thomomys talpoides) damage. Either 4 or 8 seedlings were planted in 40-m² subplots (1000 or 2000 seedlings/ha) and monitored for gopher damage. We found that the number of seedlings attacked by gophers, and consequently, the number of seedlings surviving for 5 years, were directly proportional to the stocking rate, but the consistency of seedling distribution within each site (as measured by the proportion of 40-m² subplots with ≥ 2 surviving seedlings) did not double with stocking rate. In some situations, increasing the stocking rate should be considered as a method for overcoming pocket gopher damage.     

A steroid anaesthetic for cats

Extract

Hans Selye, at McGill University, Montreal, was the first to demonstrate the anaesthetic activity of steroids — in 1941. While investigating the effects of overdosage of several steroid hormones in rats, he discovered that large amounts injected intraperitoneally induced anaesthesia. His observations have led to the development, some 30 years later, of a new steroid anaesthetic. The preparation was investigated under the provisional name CT 1341, and clinical trials in animals and man have shown that it possesses many useful properties. This preparation is now available under the trade name “Saffan” (Glaxo).     

The concept of rural community practice (RCP)

The need to devote more human resources to veterinary public practice to cope with escalating threats to biological security, public health, and economic prosperity, while also addressing societal value changes, has been widely recognized and supported. Most envisage increasing the numbers of veterinarians in government employment. Why not at least combine this initiative, wherever possible, with far greater involvement of rural practitioners to deliver contractual public-practice services and provide an enhanced community interface? This could make the difference between having a local practice in a community or none at all, as well as promising to be more cost effective. The concept of rural community practice (RCP) envisages combining traditional services provided in a "mixed-animal" veterinary practice with an expanded portfolio of public-practice and communication services that meet the emerging animal, public, and ecosystem health needs of the collective community, not just those of animal owners. These services could include those involving active sentinel surveillance programs for both domestic animal and wildlife diseases; on-farm food safety; bio-security; traceability and export certification and audit programs; disease investigation, including foreign animal diseases; surge capacity emergency response; managing for ecosystem health; and client and community education. An expanded practice team of animal-health professionals and technologists, led by veterinarians, would deliver these services. This RCP approach should have the potential to make rural practice more attractive from economic, lifestyle, and job-satisfaction perspectives; to enhance the visibility and recognition of the profession; and to respond to changing and new societal needs. It also promises to maintain a stable network of veterinary practices in rural communities. In addition, the recognition of veterinary medicine as a public good should provide for consideration of increased investment by levels of government. At the same time, this new model could help meet the demands of animal and public-health government agencies that face expanding responsibilities during a sustained climate of reduced budgetary resources.     

Risk factors associated with the salmonella status of dairy farms in England and Wales

Between October 1999 and February 2001 the salmonella status of 449 dairy farms in England and Wales was determined by environmental sampling on up to four occasions. Data were collected through interview-based questionnaires, and multivariable analyses were used to identify risk factors associated with the farms either being Salmonella positive (prevalence data) or becoming Salmonella positive (incidence data). Region, herd size, month of visit and the lack of a clean visitor parking area were significantly associated with the prevalence of Salmonella species, and there was a significant trend towards an increased risk in late summer and autumn. The introduction of six- to 24-month-old cattle into a herd was associated with a reduced prevalence, but the introduction of adult cattle only, or calves with other cattle, was associated with an increased (but not significant) risk of farms being Salmonella positive. Month of visit, the lack of a clean visitor parking area, the use of part-time workers and not feeding calves whole milk, but not region or herd size, were associated with an increased incidence of salmonella.     

Plasma concentrations of parathyroid hormone-related protein in dogs with potential disorders of calcium metabolism

The plasma concentrations of total calcium, ionised calcium, albumin, parathyroid hormone and parathyroid hormone-related protein (PTHrp) were measured in 25 dogs with lymphoma, nine dogs with primary hyperparathyroidism and seven dogs with adenocarcinoma of the apocrine gland of the anal sac. Plasma total calcium, ionised calcium, albumin and parathyroid hormone-related protein were measured in 18 clinically normal control dogs. The concentration of PTHrp was high in 12 of the 14 dogs that were hypercalcaemic because of an underlying malignancy but was within the reference range in all the control dogs, in the 17 normocalcaemic dogs with lymphoma and in the seven dogs which were hypercalcaemic because of a parathyroid adenoma.     

Synthesis and characterization of the nitrides of platinum and iridium

Transition metal nitrides are of great technological and fundamental importance because of their strength and durability and because of their useful optical, electronic, and magnetic properties. We have evaluated a recently synthesized platinum nitride (PtN) that was shown to have a large bulk modulus, and we propose a structure that is isostructural with pyrite and has the stoichiometry PtN2. We have also synthesized a recoverable nitride of iridium under nearly the same conditions of pressure and temperature as PtN2. Although it has the same stoichiometry, it exhibits much lower structural symmetry. Preliminary results suggest that the bulk modulus of this material is also very large.     

Growth and Infestation by Hemlock Woolly Adelgid of Two Exotic Hemlock Species in a New England Forest

ABSTRACT

The hemlock woolly adelgid (HWA, Adelges tsugae Annand) an invasive exotic insect, may extirpate eastern hemlock (Tsuga canadensis (L.) Carrière) trees from native forests, but other hemlock species could be planted to occupy their ecological niche. This study tests two of the most likely replacement species candidates: western hemlock (T. heterophylla (Raf.) Sargent) and Chinese hemlock (T. chinensis (Franchet) Pritzel). Low survival rates, slow growth, and infestation by HWA of western hemlock in eastern hemlock forests shows that the western hemlock is not a likely candidate for planting in the northern portion of eastern hemlock's range. In contrast, Chinese hemlock grew at rates similar to eastern hemlock and did not show any signs of HWA infestation. In this study, damage from deer was a much bigger problem than growth reductions from HWA.