Variation in water relations of black spruce stock types planted in Ontario

Upland, intermediate and lowland sites in northeastern Ontario were planted between May 28 and June 8 with three types of black spruce (Picea mariana (Mill.) BSP) nursery stock: (1) spring-lifted, 1.5 + 1.5 bareroot plants (BR); (2) 24-week-old, winter-sown, container stock (CWS); and (3) spring-sown, overwintered, container stock (CO). At the beginning of the growing season, the BR stock had the lowest xylem pressure potentials (Psi(x)), stomatal conductances (g(wv)), and net photosynthetic (P(n)) rates. By the end of the growing season, the BR stock still had lower g(wv)s than the container stock types, but had higher shoot Psi(x) values. In August, the turgor loss points for the BR, CO and CWS stock types were -2.8, -1.93 and -1.6 MPa, respectively, while the minimum observed shoot Psi(x) values were -1.4, -1.7 and -1.9 MPa, respectively. The BR stock produced the greatest dry weight of new shoots and unsuberized roots. No new shoots were produced by the CWS stock, but they produced a greater dry weight of unsuberized roots than the CO stock. As a percent of the dry weight of suberized roots, the greatest production of unsuberized roots was by the CWS stock, the least by the BR trees.     

A pulmonary granular cell tumour with associated hypertrophic osteopathy in a horse

Abstract Extract A 15-year-old pony mare developed firm irregular bony swellings on all four legs. These were most severe around the carpal and fetlock joints of the forelegs, restricting both flexion and extension. Over about 6 months the horse had periodic bouts of coughing. She showed moderate weight loss and a depressed demeanour.     

Veterinary students and their reported academic and personal experiences during the first year of veterinary school

Veterinary students completed an online survey regarding personal and academic concerns they experienced during their first year of veterinary school. Quantitative results showed a high degree of stress and anxiety among the study participants as well as concerns about time management and study skills. Quantitative analysis using chi-square tests revealed significant associations between concerns about study skills and the independent variables of relationship status and time since obtaining an undergraduate degree. Results of a thematic analysis undertaken with the qualitative data provide further insight into first-year experiences, indicating concerns about the intensity of the program and especially about time commitment, the amount of information students were expected to learn, and the amount of material they were expected to memorize. Another theme revealed that students did not feel academically prepared for some of their first-year courses, which led to their not liking those courses for which they lacked appropriate groundwork. Other themes highlighted the students' desire for more clinically relevant experiences during their first year as well as surprises regarding the maturity level of classmates and the level of support offered by professors. Given the results of this study, suggestions for counselors and others who work with veterinary students are provided.     

Potential for reintroduction of lake sturgeon in five northern Lake Michigan tributaries: a habitat suitability perspective

• 1. Conservation and rehabilitation efforts for lake sturgeon Acipenser fulvescens throughout the Great Lakes include the re‐establishment of self‐sustaining stocks in systems where they have been extirpated.
• 2. Information on the suitability of potential lake sturgeon habitat in tributaries is important for determining their capacity to support lake sturgeon stocking and to develop system‐specific rehabilitation strategies.
• 3. Geo‐referenced habitat information characterizing substrate composition, water depth, and stream gradient were applied to a life‐stage specific lake sturgeon habitat suitability index in a geographic information system to produce spatially explicit models of life‐stage specific habitat characteristics in five northern Lake Michigan tributaries from which lake sturgeon have been extirpated.
• 4. Habitat models indicated that high quality lake sturgeon spawning and staging habitat comprised 0 to 23% and 0 to 9% of the available habitat, respectively, whereas high quality juvenile lake sturgeon habitat was relatively ubiquitous throughout each river and comprised 39 to 99%.
• 5. Comparison of these data to lake sturgeon habitat availability in Lake Michigan tributaries currently supporting populations indicated that spawning and staging habitats may limit the ability of these systems to support spawning. Efforts to re‐establish lake sturgeon populations in these systems should consider the creation of spawning and staging habitat to increase reproductive and recruitment potential prior to the initiation of stocking efforts.

Copyright © 2007 John Wiley & Sons, Ltd.     

The(13)C-octanoic acid breath test for detection of effects of meal composition on the rate of solid-phase gastric emptying in ponies

The aim of this study was to apply the(13)C-octanoic acid breath test for detection of alterations in the rate of solid-phase gastric emptying, induced by changes in test meal composition, in ponies. After a 14 hour fast the ponies (n = 4) ingested a test meal with 0, 35 or 70 ml soya oil, and labelled with 250 mg(13)C-octanoic acid. Each pony was given each of the three test meals on three separate occasions, in a randomised order. Exhaled breath samples were collected for 12 hours after ingestion of the test meal. Breath samples were analysed by continuous flow isotope ratio mass spectrometry. Three indices of breath(13)C-enrichment were computed, half-dose recovery time (t 1/2), gastric emptying coefficient (GEC) and time to peak breath(13)C-excretion t(max). The(13)C-octanoic acid breath test was a reliable means of assessing the significantly decreased rate of gastric emptying in the pony, associated with addition of soya oil to the test meal.