Prescribed burning effects on summer elk forage availability in the subalpine zone, Banff National Park, Canada.

The effects of prescribed burning on forage abundance and suitability for elk (Cervus elaphus) during the snow-free season was evaluated in east-central Banff National Park, Canada. Six coniferous forest and mixed shrub-herb plant communities (n=144 plots), and 5223ha of burned (n=131) vegetation <12 years old were sampled using a stratified semi-random design. Sampling units represented various combinations of vegetation, terrain conditions, and stand ages that were derived from digital biophysical data, with plant communities the basic unit of analysis. Burning coniferous forest stands reduced woody biomass, and increased herbaceous forage from 146 to 790 kg/ha. Increases commonly occurred in the percent cover of hairy wild rye (Leymus innovatus (Beal) Pigler) and fireweed (Chamerion angustifolium (L.) Holub.). The herbaceous components of mixed shrub-herb communities increased from 336-747 kg/ha to 517-1104 kg/ha in response to burning (P<0.025, Mann-Whitney U-test). Browse biomass (mostly Salix spp. and Betula nana L.) increased >or=220% (P

Investigation, control and epizootiology of anthrax in a geographically isolated, free-roaming bison population in northern Canada.

In July 1993 anthrax caused significant mortality in an isolated, free-ranging population of bison (Bos bison athabascae) west of Great Slave Lake in the Northwest Territories. There was no previous record of anthrax in this area. An emergency response was undertaken to reduce the scale of environmental contamination and dissemination of anthrax spores and hence to reduce the likelihood of future outbreaks. One-hundred-and-seventy-two bison, 3 moose (Alces alces), and 3 black bear (Ursus americanus) carcasses were found. Visual detection of carcasses was enhanced with the use of an airborne, remote infrared sensing camera mounted externally on a helicopter. Fifty-five percent of the carcasses were located in forested or shrub-covered sites where detection would not have been likely without the thermal imaging equipment. Carcasses were disposed of by incineration and the sites were decontaminated with formaldehyde. Application of formaldehyde to carcasses prevented scavenging. The outbreak occurred after a prolonged period of drying between April and mid-July 1993 which followed several successive years of flooding of bison habitat. The "spore concentration hypothesis" provides the most conservative explanation for the occurrence of anthrax under the observed conditions.

Capture of wood bison (Bison bison athabascae) using carfentanil-based mixtures.

Between 1986 and 1991, 155 wood bison (Bison bison athabascae) (33 adult females, 92 adult males, twelve 6 mo-old calves, eighteen 1 to 2 mo-old calves) in the Mackenzie Bison Sanctuary, Northwest Territories, Canada, and adjacent area were captured by dart immobilization. Initial trials with carfentanil, xylazine and R51163 as immobilizing agents were conducted. Subsequently, carfentanil alone, or in combination with xylazine, was used. Small doses of xylazine were used when required to control head and hind limb movement of recumbent bison. The mean dose of carfentanil used was 7.0 micrograms/kg. Narcotic antagonists used were naltrexone, naloxone and M5050. Narcotic recycling was seen in animals treated with naloxone and low doses of naltrexone. Furthermore recycling was suspected in the deaths of several animals treated with these antagonist regimes. No recycling was seen when doses of naltrexone in excess of 90:1 naltrexone:carfentanil were used. We recommend using a naltrexone:carfentanil dose in excess of 125:1 to ensure uneventful recovery.

The brucellosis and tuberculosis status of wood bison in the Mackenzie Bison Sanctuary, Northwest Territories, Canada.

Postmortem examinations were done on 51 wood bison (Bison bison athabascae) killed as part of a multidisciplinary research project in the Mackenzie Bison Sanctuary, Northwest Territories, Canada, between 1986 and 1988. There was no gross, histological or bacteriological evidence of brucellosis or tuberculosis in these bison. Traumatic lesions were seen in one calf that had been attacked by wolves and a second calf that had been gored. Antibody titers to Brucella abortus were not found in sera from these 51 animals or an additional 112 wood bison that were chemically-immobilized or killed in the Sanctuary between 1986 and 1990. The combined prevalence of the diseases in the population could not have exceeded 5.95% for the necropsy survey to have missed finding at least one infected animal, and the prevalence of brucellosis in the population would have had to be less than 1.95% for the broader serological survey to have failed to find at least one reactor animal on the battery of tests. These results, and the cumulative epidemiological information on brucellosis and tuberculosis in bison, indicate that bovine brucellosis and tuberculosis are not enzootic in the wood bison population in and around the Mackenzie Bison Sanctuary, and suggest that the population is free of these diseases. However, this expanding population is at risk of contracting both diseases from the infected bison population in and around nearby Wood Buffalo National Park.

The "most-significant-other" in the care of the breast cancer patient.

Most-significant-others can play a major role in helping breast cancer patients live stable, productive, and esteemed lives. Physicians are urged to respect and exercise their clinical judgment on the emotional makeup of the patient, the most-significant-other, and their relationship, and to instruct them according to their needs and capacities. Supportive roles include mobilizing social support; monitoring the patient's return to daily living; being with her during treatments, both physically and emotionally; and understanding her instinctive requests for assistance through double-bind and other difficult communication. Most-significant-others can be an extension of the physician's common sense and clinical care to the degree that they are able and willing to perform this important role.

Prenatal infection of the Rocky Mountain bighorn sheep (Ovis c. canadensis) of Alberta with the lungworm Protostrongylus spp.

First- and third-stage (infective) larvae of Protostrongylus spp. were recovered from the livers of four fetuses of the Rocky Mountain bighorn sheep of Alberta. This record suggests a more cosmopolitan distribution of prenatal infection with lungworms in bighorn sheep than suspected previously.