RESEARCH PAPER: Ultrasound‐guided nerve blocks of the pelvic limb in dogs

ObjectivesTo evaluate the efficacy of ultrasound‐guidance in nerve blockade of the sciatic and saphenous nerves in dogs and to determine if this technique could allow lower anaesthetic doses to be used with predictable onset and duration of effect.Study designProspective randomized (for dose and leg) blinded experimental crossover trial with 10 day washout period.AnimalsSix healthy female Hound dogs aged 12.3 ± 0.5 (mean ± SD) months and weighing 18.7 ± 0.8 (mean ± SD) kg.MethodsAn ultrasound‐guided, perineural injection was used with saline at 0.2 mL kg^?1 (Sal) or bupivacaine 0.5% at 0.05 (low dose; LD), 0.1 (medium dose; MD), or 0.2 (high dose; HD) mL kg^?1, divided 2/3 at the sciatic nerve and 1/3 at the saphenous nerve. Blocks were performed using dexmedetomidine sedation with atipamezole reversal immediately after completion of the injections. Motor/proprioceptive and sensory functions were scored using a 0–8 and a 0–2 scale, respectively. Clinically relevant blocks were defined as a motor score ≥2 and sensory score ≥1. Nonparametric methods were used for statistical analysis.ResultsNo adverse effects were noted. There was a significant difference between the treatments with bupivacaine and the saline control, but not between the three bupivacaine treatments. Success rates of clinically relevant sciatic and saphenous blocks were both 67% (CI 95% 0.22–0.96). Onset and duration of the blocks were variable; 20–160 and 20–540 minutes, respectively.Conclusion and clinical relevanceNone of the bupivacaine doses was significantly superior, though there was a tendency for a better block with the high bupivacaine dose. Either the technique or the doses used need further modification before this method will be useful in clinical practice.     

Altered Herbivore Distribution Associated With Focal Disturbance

Natural disturbances historically created structurally diverse patterns across the landscape, and large herbivores concentrated herbivory in areas where disturbance decreased standing senesced biomass that acted as a grazing deterrent through decreased palatability and overall forage quality. However, following European settlement, many natural large-scale disturbance regimes that influence vegetation and herbivore grazing selection were altered or removed and replaced with fine-scale anthropogenic disturbances. It is unclear how fine-scale focal disturbance and alteration of vegetation structure influences livestock distribution and grazing. Therefore we used a tracked vehicle as a disturbance agent in a mesic mixed-grass prairie to assess the influence of focal anthropogenic disturbance on livestock distribution and grazing. Track vehicle disturbance decreased the height of vegetation (P < 0.05) but did not alter plant species composition (P > 0.05). Cattle fecal pat density was greater (P ≤ 0.05) in locations with track vehicle disturbance. Little bluestem tiller height was shorter (P ≤ 0.05) in tracked locations than nontracked locations in grazed treatments, but was not different in nongrazed locations the first growing season following disturbance. Fecal pat density and tiller height were not different (P > 0.05) between tracked and nontracked locations following the second growing season. Therefore, we concluded that fine-scale focal anthropogenic disturbance alters herbivore distribution and defoliation and can maintain structural heterogeneity, but the effect is ephemeral and does not create long-lasting grazing lawns.     

Hybrids of <Emphasis Type="Italic">Avena sativa</Emphasis> with two diploid wild oats (CIav6956) and (CIav7233) resistant to crown rust

Two diploid accessions of wild oat, CIav6956 and CIav7233, were identified as carrying seedling resistance to oat crown rust (caused by Puccinia coronata f. sp. avenae; Pca). Two vigorous interploidy F₁ hybrids were generated from crosses involving the hexaploid oat cultivar Wintaroo and the diploid oat Avena strigosa Schreb. accession CIav6956. An additional interploidy F₁ hybrid, designated “F1-Aa1”, was produced from a cross of Wintaroo and the diploid oat accession CIav7233. All three hybrids were more vigorous and taller than the cultivated parent Wintaroo. The three F₁ hybrids contained full chromosome complements from both parents (2n = 4x = 28), but no seeds were obtained when the three F₁ hybrids were selfed. Meiotic analyses of the hybrids indicated that they exhibited a high degree of inter-genome and intra-genome pairing. Trivalent configurations were detected in 95–96% of meiotic cells and a minimum of three bivalents was present in all cells. An average chiasma frequency of 7.2–7.9 per cell was observed for the three F₁ hybrids. A fourth F₁ hybrid was subsequently generated from a cross between the diploid oat accession CIav7233 and Wintaroo. One octaploid (2n = 8x = 56) was generated from this hybrid and progeny were resistant to two Pca races. The chromosome number of the octaploid progeny varied between 51 and 54 chromosomes. Development of a chromosome addition line(s) with the crown rust resistance should be possible from these partial-octaploids.     

Evaluation of microsatellite instability in urine for the diagnosis of transitional cell carcinoma of the lower urinary tract in dogs

Background: The accumulation of frame‐shift mutations in microsatellites (MS), termed microsatellite instability (MSI), is associated with certain tumors. MSI and its detection in urine samples has been used to aid in the detection of human bladder cancer. Hypothesis: Evaluation of MSI in urine is a useful assay test for diagnosis of transitional cell carcinoma (TCC) in dogs and is more specific than the commercially available, veterinary bladder tumor analyte (V‐BTA) test. Animals: Seventy‐three dogs: healthy controls (n= 21), proteinuric (n= 12), lower urinary tract disease excluding TCC (n= 17), and TCC (n= 23). Methods: Prospective observational study. Urine samples collected from each animal were evaluated for MSI and using the V‐BTA. For MSI detection, 22 MS sequences were polymerase chain reaction amplified from urine and blood, subjected to capillary electrophoresis, and the MS genotypes were compared. Aberration in ≥15% of MS was considered indicative of MSI. Results: MSI was detected in 11 of 23 (48%) urine samples from dogs with TCC. MSI was also detected in 12 of 50 (24%) of the control animals, including 29, 16, and 24% of healthy, proteinuric, and lower urinary disease dogs, respectively. In this population, sensitivity and specificity of MSI analysis was 48 and 76%, respectively, compared with 83 and 64%, respectively, for the V‐BTA test. Conclusions: MS analysis as performed in this study is not useful in the diagnosis of TCC.     

Rate of gas phase association of hydroxyl radical and nitrogen dioxide

The reaction of OH and NO(2) to form gaseous nitric acid (HONO(2)) is among the most influential in atmospheric chemistry. Despite its importance, the rate coefficient remains poorly determined under tropospheric conditions because of difficulties in making laboratory rate measurements in air at 760 torr and uncertainties about a secondary channel producing peroxynitrous acid (HOONO). We combined two sensitive laser spectroscopy techniques to measure the overall rate of both channels and the partitioning between them at 25°C and 760 torr. The result is a significantly more precise value of the rate constant for the HONO(2) formation channel, 9.2 (±0.4) × 10(-12) cm(3) molecule(-1) s(-1) (1 SD) at 760 torr of air, which lies toward the lower end of the previously established range. We demonstrate the impact of the revised value on photochemical model predictions of ozone concentrations in the Los Angeles airshed.     

Benchmark stem densities for forests and woodlands in south-eastern Australia under conditions of relatively little modification by humans since European settlement

Estimates of forest and woodland structure prior to major periods of modification (e.g. prior to European settlement) are routinely used to inform decisions relating to biodiversity conservation, silviculture and carbon sequestration potential in natural forests and woodlands. The techniques used to derive these estimates often demand that data be collected from specific geographic locations (e.g. locations for which historic survey records exist, where pollen accumulates, or where there is little modification by humans since European settlement) and therefore are often inherently biased. In this study we predicted numbers of trees by diameter class for several widespread forest and woodland types in south-eastern Australia under conditions of relatively little modification by humans since European settlement. To do this we fitted Generalised Additive Models (GAMs) separately to counts of stems in eight diameter classes from 495 plots using explanatory variables representing human modification, environmental variation and natural disturbances. We predicted stem densities under conditions of relatively little modification by humans since European settlement from these models by holding the significant explanatory variables representing modification by humans at minimum observed values. We compared these predictions with published estimates of pre-European stem densities and estimates that we derived for stands at theoretical equilibrium using the quotient of diminution (q). Our mean predictions were broadly comparable with estimates derived from both of these sources; however, we appeared to over-estimate numbers of stems in the smaller diameter classes for some vegetation alliances. A key outcome of this research – and rarely reflected in other techniques used to predict pre-European forest structure – was the amount of variation in stem numbers even within a single diameter class and vegetation alliance. For example, in the white box vegetation alliance, flat parts of the landscape supported 5 times the number of large trees (>80 cm DBH) found on upper slopes under conditions of relatively little modification by humans since European settlement. Our results therefore suggest that these forests and woodlands are more structurally heterogeneous than typically reflected in pre-European estimates and vegetation alliance should not be the unit for managing these stands. The methodology we present is applicable in many forests where the objective is to predict forest structure under conditions of relatively little modification by humans.     

High incidence of glomerulonephritis associated with inclusion body hepatitis in broiler chickens: routine histopathology and histomorphometric studies

During the routine histologic evaluation of an outbreak of inclusion body hepatitis (IBH) in Mississippi broilers, a high incidence of renal enlargement and glomerulonephropathy was observed in the birds presenting classic hepatic pathology. Characteristic intranuclear adenoviral inclusion bodies were demonstrated in the livers of these birds, and fowl adenovirus was identified by viral isolation and by PCR. The glomerular lesions were consistent with proliferative or membranoproliferative forms of glomerulonephritis. Histomorphometric evaluations were performed to generate a more quantitative analysis of altered glomerular size and cellularity, to detect statistically significant borderline changes, and to get a clearer insight into the incidence of the glomerular alterations. Marked increases in both the average glomerular size (area) and the total glomerular cellularity were observed for the affected glomeruli relative to normal controls. The average glomerular area values for normal glomeruli in the peripheral subcapsular cortical and central cortical kidney regions were 1791 microm2 and 5302 microm2, respectively. In contrast, glomerular measurements for kidneys exhibiting glomerulonephritis by routine histopathology, had average values for the two regions of 4429 microm2 and 11,063 microm2. The average glomerular cell counts for the two regions in controls were 44 and 107 cells/ glomeruli, while averages for birds with glomerulonephritis were 85 and 193 cells/glomeruli. The proportion of IBH-associated glomeruli greater than two standard deviations above the mean glomerular size of the normal controls was 52% for the central region and 62% for the peripheral region.     

Allelic variation of polyphenol oxidase genes impacts on Chinese raw noodle color

Polyphenol oxidase (PPO) activity is a factor in time-dependent discoloration of Asian noodles. At least two major genes Ppo-A1 and Ppo-D1 control kernel PPO activity in wheat. The goal was to determine the relative importance of allelic variation for Ppo-A1 and Ppo-D1 on Chinese raw noodle color profile and kernel and flour characteristics using a winter wheat recombinant inbred population segregating for Ppo-A1 and Ppo-D1. Ppo-A1 allelic variation explained 80% and Ppo-D1 allelic variation explained 2% of the variation in kernel PPO activity. The low PPO allele at each locus gave noodles that were brighter (greater L*), more yellow (greater b*) and more red (greater a*) at 24 h, and noodles with less change in L* but more change in a* and b* with time (0-24 h). The two loci combined explained 27, 35, and 17% of variation in L*, a*, and b* at 24 h, and 51, 55, and 58% of the variation in change in L*, a*, and b* with time, respectively. Allelic variation at Ppo-D1 explained a larger percentage of variation than did Ppo-A1 in each case except b* at 24 h where the two loci explained equal amounts.     

Are changing diver characteristics important for coral reef conservation?

1. the 2012 industry has a higher proportion of low and medium specialization visitors that have lower expectations and lower overall satisfaction, yet remain willing to return;
2. the average per capita economic contribution of divers to the local economy and to dive companies declined by more than 30% by 2012;
3. Andaman coast diving continued to grow in 2012, dominated by mass ‐ market tourism that had diversified into several niches;
4. the results verify the use of the Wildlife Tourism Model as a tool to understand industry sustainability, and suggest further development of the model to capture the extension into specific, niche markets.

Changes to diver characteristics in 2012 restrict the ability of diving to fund conservation, provide alternative livelihoods, support environmental choices by operators, and control dive pressure exerted on reefs.

Results suggest the operationalization of Limits of Acceptable Change by both managers and dive operators to grow the conservation value of diving.

The results of this study suggest that the Wildlife Tourism Model can be used to inform management choices in emerging dive destinations. For instance, creating spatial zones that target the tourist composition most appropriate to meet the conservation goals of each reef system.

Copyright © 2015 John Wiley & Sons, Ltd.