Behavioral evaluation of 65 aggressive dogs following a reported bite event

Peer-reviewed scientific publications on the topic of dog bites are numerous. Montreal was one of the first municipalities in the province of Quebec to require mandatory assessment of aggressive dogs by veterinarians. In 2019, dogs reported as aggressive and considered a potential risk to public safety by city officials were scheduled for a mandatory behavioral assessment by a veterinarian. For the purpose of this study, only aggressive dogs that had bitten (N = 65) were included. The goals were to better describe the aggressive behavior of these dogs (behavioral sequence, type of aggression, and overall reactivity) and perhaps identify new possible risk factors related to severity of injury and dangerousness. The number of signs of increased arousal/reactivity was positively and significantly associated with the injury severity score. Dangerousness increased with size of dogs. Entire males were most dangerous despite absence of recognizable differences in body weight between neutered and unneutered males.     

Denitrification with different sizes of soil aggregates obtained from dry-sieving and from sieving with water

Summary The spatial variability of denitrification in soil was studied further by comparing dry-sieved and wetsieved aggregates of different sizes. It was observed that the denitrification rate generally decreased as the drysieved aggregate size increased. In contrast, the denitrification rate increased as the wet-sieved aggregate size increased. In both cases, however, the denitrification rate was positively related to aerobically mineralizable C. Oven-warming of the wet-sieved aggregates at 105°C for 30 min increased the denitrification rate, apparently due to the release of C substrate. Nevertheless, the positive relationship between the denitrification rate and the wetsieved aggregate size persisted. There was no clear relationship between water-soluble C and the denitrification rate. There may have been a contribution from C in microbial polysaccharides in aggregates of different sizes. The results demonstrated that there was a large spatial variability in denitrification over short distances in soil, which was associated with aggregates of different sizes and water stability.     

Restocking with broadleaved species during the conversion of Tsuga heterophylla plantations to native woodland using natural regeneration

The removal of conifers planted during the twentieth century on sites that had been woodland for many centuries, with the intention of restoring native broadleaved species, is an important aim of forestry policy in Great Britain. Current guidance generally advocates gradual removal of plantation trees using continuous cover silviculture and restocking by natural regeneration, but methods are largely untested. This study investigated natural regeneration of trees and shrubs at sites where western hemlock had been established either pure or in mixture with native broadleaved species. Western hemlock had been cleared from 70% of the sites. There were c. 10?C300 stems ha^?1 providing canopy cover of 10?C90%; the predominant broadleaved canopy trees were ash, beech, birch and oak. The ground flora of all sites was species poor; bramble was the predominant vegetation type overall, but grasses, rushes and shrubs were relatively more abundant on open sites. A total of 15 native tree species were regenerating, birch was most common and at most sites there were few valuable broadleaved timber species. Although combined numbers of seedlings and saplings varied from 200 to 20,000 ha^?1, large areas of most sites had few regenerating trees and <10% of their area was becoming restocked with timber species. Relationships between seedling numbers and site characteristics were complex and varied with species, but there was a consistent positive relationship between the presence of nearby parent trees and the frequency and abundance of seedlings. The results indicate that the current reliance on natural regeneration may be unwise especially for those broadleaved species such as oak and beech which are valued for their timber.     

Effects of continuous oral administration of phenylbutazone on biomarkers of cartilage and bone metabolism in horses

OBJECTIVE: To evaluate the effects of continuous oral administration of phenylbutazone on serum and synovial fluid biomarkers of skeletal matrix metabolism in horses. ANIMALS: 11 adult female horses without clinical or radiographic evidence of joint disease. PROCEDURES: Horses were randomly assigned to control or treatment groups. Phenylbutazone was administered orally twice daily at a dose of 4.4 mg/kg for 3 days to the treatment group and subsequently at a dose of 2.2 mg/kg for 7 days. Serum and radiocarpal synovial fluid samples were obtained at baseline and thereafter at regular intervals for 4 weeks. Biomarkers of cartilage aggrecan synthesis (chondroitin sulfate 846) and type II collagen synthesis (procollagen type II C-propeptide) and degradation (collagen type II cleavage) were assayed. Biomarkers of bone synthesis (osteocalcin) and resorption (C-terminal telopeptide of type I collagen) were also measured. RESULTS: No significant differences were found between control and treatment groups or temporally for the biomarkers chondroitin sulfate 846, procollagen type II C-propeptide, collagen type II cleavage, and C-terminal telopeptide of type I collagen in serum or synovial fluid. A significant increase in osteocalcin concentration occurred in synovial fluid during treatment in the treated group. No treatment effect was detected for serum osteocalcin concentration. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that continuous phenylbutazone administration at recommended doses altered some biomarkers in healthy equine joints after short periods of administration. Increased osteocalcin concentration may indicate an undetermined anabolic effect of phenylbutazone administration on periarticular bone or transient induction of osteogenesis in articular chondrocytes or a mesenchymal subpopulation of synoviocytes.     

Flock size and human disturbance affect vigilance of endangered red-crowned cranes (Grus japonensis)

Vigilance is used to detect predators and monitor rivals. We studied red-crowned cranes (Grus japonensis) in Yancheng Biosphere Reserve, China, to examine changes in the allocation of time to vigilance as a function of flock size in areas with different levels of human disturbance. There was low level of human activity in the core area of the reserve whereas more human activity occurred in the buffer zone. Vigilance decreased linearly with flock size but to significantly different extent in the two areas, with a more pronounced decrease in the more disturbed area. In smaller crane flocks, vigilance was higher in the more disturbed area. Vigilance also varied in a non-linear fashion with flock size first decreasing and then increasing in larger flocks. Increase in vigilance in larger flocks was accompanied by an increase in fighting suggesting that vigilance in large flocks was aimed partly at monitoring rivals. The effect of human disturbance on vigilance suggests that less time is available for foraging in more disturbed areas. Nevertheless, moving to less disturbed areas may not be an option for the cranes given the increase in vigilance that would probably occur in areas with more cranes.     

Reactions of 15N-labelled urea with jack pine forest-floor materials

Urea, labelled with¹⁵N, was applied, at rates equivalent to 0–400 kg N ha^?1, to mixed L + F horizon soil materials from a jack pine (Pinus banksiana Lamb.) forest. The L + F materials were held at 13°C and 33 kPa moisture in three experiments lasting from 6 to 128 days. In the first experiment the immobilization of fertilizer N was determined, in the second the stimulation of microbial activity was measured, and in the third urea reactions in a forest floor without microorganisms were examined. Urea stimulated microbial activity and microbial mineralization of soil N. Total amounts of N immobilized and recovered as organic N, after 128 days, increased with rate of application from 50 to 400 kg urea-N ha^?1. The pH and C contents of water extracts of soil increased with increasing rates of urea application. Organic matter in a forest floor treated with urea was shown to solubilize after microbial activity was inhibited by gamma radiation, and this suggests that chemical C release was brought on by the urea. Results from this study were consistent with the hypothesis that microbial activity in urea-treated soil is stimulated by increased availability of C in soil.