Modeling connectivity of black bears in a desert sky island archipelago

Landscape features such as rivers, mountains, desert basins, roads, and impermeable man-made structures may influence dispersal and gene flow among populations, thereby creating spatial structure across the landscape. In the US–Mexico borderland, urbanization and construction of the border fence have the potential to increase genetic subdivision and vulnerability to isolation in large mammal populations by bisecting movement corridors that have enabled dispersal between adjacent Sky Island mountain ranges. We examined genetic variation in black bears (Ursus americanus) from three regions in central and southern Arizona, US, to assess genetic and landscape connectivity in the US–Mexico border Sky Islands. We found that the three regions grouped into two subpopulations: the east-central subpopulation comprised of individuals sampled in the central highland and high desert regions, and the border subpopulation comprised of individuals sampled in the southern Sky Islands. Occupancy for the border subpopulation of black bears was influenced by cover type and distance to water, and occupancy-based corridor models identified 14 potential corridors connecting border Sky Island habitat cores with the east-central subpopulation. Biological quality of corridors, defined as length:width ratio and proportions of suitable habitat within corridors, declined with Sky Island dispersion. Our results show that black bears in the border subpopulation are moderately isolated from the east-central subpopulation, the main population segment of black bears in Arizona, and that connectivity for border bears may be vulnerable to anthropogenic activities, such as those associated with urbanization and trans-border security.     

Some Factors Affecting the Balance of Phytophagous and Predacious Mites on Apple in South-East England

A study of the importance of predators of the Fruit Tree Red Spider Mite, Metatelranychus ulmi (Koch), in Nova Scotian orchards twenty years ago led Gilliatt (1935) to conclude that another mite, Seiulus pomi Parrott, predacious on M. ulmi, was a major factor in the control of the latter under suitable conditions. S. pomi, however, was found to be very susceptible to the winter oil and lime-sulphur sprays applied as a routine at that time, and was unable to prevent increases of M. ulmi in such orchards. Similar increases of M. ulmi in Ohio orchards receiving sulphur sprays were attributed by Cutright (1944) to the greater susceptibility of predacious mites to this chemical.     

The relationship between different spray combinations of certain fungicides with calcium nitrate and the incidence of bitter pit and fungal diseases of apple

Two apple cultivars, Cox’s Orange Pippin and Worcester Pearmain, were sprayed at high volume for scab control in two seasons with either captan or thiram, with dinocap to control mildew. On Worcester, it was confirmed that thiram reduced crop and increased fruit russet and bitter pit incidence; the proportion of misshapen fruits was also increased. On Cox, thiram reduced crop number, without any compensatory increase in weight, and provided inferior scab control as well as increasing fruit russet.

The application of commercial calcium nitrate (C.C.N.) four times between mid-June and mid-August led to a considerable reduction in the incidence of bitter pit and storage rots in fruits from trees sprayed with captan and dinocap; it also partially offset the greater incidence of bitter pit associated with thiram treatments. In contrast to this, the application of a similar total amount of calcium, either in the form of a standard lime sulphur programme or by adding C.C.N, to the organic fungicide programmes for scab control, i.e. from April to mid-July, failed to reduce the incidence of bitter pit on either cultivar. Neither C.C.N, programme affected cropping, fruit russeting or scab control on either cultivar.

The ratio of potassium to calcium was higher in leaves and fruits from Worcester trees receiving thiram than in those from trees receiving captan; the application of C.C.N, in the summer reduced this ratio in fruits from trees receiving captan but not in those from trees receiving thiram, although it reduced the incidence of bitter pit associated with both fungicide programmes.

Results on Cox show that fungicide deposition and control of scab were independent of fungicide formulation and of the presence or absence of C.C.N. ; mildew control was not affected when C.C.N, was applied as the recommended summer programme.     

Site of Intrauterine Artificial Insemination in the Bitch does not Affect Sperm Distribution within the Uterus

The aim of this study was to evaluate the distribution of frozen–thawed spermatozoa within the uterine lumen and oviducts following intrauterine laparoscopic deposition at two sites. Twelve bitches of unknown reproductive history were randomly distributed into two groups. Semen (3 ml containing 300 × 10⁶ frozen–thawed spermatozoa) was infused at the uterine body (UB group) or at the cranial tip of the left uterine horn. A 22‐G catheter was used to access the uterine lumen. Sperm cell distribution was evaluated after ovariohysterectomy performed 3 h after artificial insemination (AI). There was no difference between groups in mean time to perform AI. Spermatozoa were detected in all uterine segments, including the tip of both horns, but none was detected in the oviduct. The 22‐G catheter facilitated deposition of semen in the uterine lumen, particularly at the UB site. Sperm cell distribution occurred evenly along both horns, independent of the site of semen deposition.     

Evaluation of otoscope cone disinfection techniques and contamination level in small animal private practice

The objective of this study was to evaluate the level of bacterial contamination of otoscope cones in veterinary private practice, and to determine the most effective method of disinfection. Fifty small animal practices participated in this study, which included a detailed survey regarding otoscope cleaning, storage and usage and quantitative culture of the cleaned and stored otoscope cones. Using sterile technique, two cones from each of the 50 hospitals were swabbed and submitted for quantitative culture. Contamination was present in 29% of the samples and the following organisms were isolated: Flavobacterium brevis (10%), Pseudomonas aeruginosa (6%), Pseudomonas alcaligenes (4%), Staphylococcus intermedius (4%), Corynebacterium spp. (2%), Bacillus spp. (1%), Enterococcus faecalis (1%) Malassezia spp. (1%). There was no statistically significant difference between storage type (dry versus stored in solution) and for the instrumentation used to clean the cones (brush, cotton‐tipped applicator, both versus none). There was a statistically significant difference between the different cleaning solutions (P < 0.001) and between the storage solutions (P = 0.003). A single most effective cleaning solution was unable to be determined due to the large number of solutions utilized. Cetylcide G^® (Cetylite Industries, Inc., Pennsauken, NJ, USA) was the most effective of the three most commonly used storage solutions (Cetylcide G^®, Benz‐all^®, and 2% Chlorhexidine gluconate) when used as directed (P < 0.001). The level of contamination had a positive association with the frequency of cone use and a negative association with the frequency of storage solution replacement.