Epidemiological observations of pancreas disease of farmed Atlantic salmon, Salmo salar L., in Ireland

Epidemiological investigations into the pancreas disease (PD) of farmed salmon were conducted on populations of Atlantic salmon reared in Ireland during 2003 and 2004. The investigations surveyed all marine salmon farms operating in Ireland through a detailed questionnaire with follow-up farm visits. Information was gathered on 21 populations of fish in 2003 and 14 populations in 2004. Thirteen of the 21 populations suffered PD in 2003 and 12 of the 14 in 2004. The mean mortality due to PD on affected farms was 18.8% in 2003 and 14.8% in 2004 and the loss of growth due to PD was estimated at 11.4% over the 2-year period. The highest risk periods for outbreaks of PD were early summer and early autumn and the farms most seriously affected by PD mortality were in the western counties of Ireland. Factors which showed an indication of association with a PD outbreak or high mortality during a PD outbreak were: livestock movement to another sea site, high feeding rate prior to any PD outbreak, the presence of another PD positive farm in the same water body, greater than 250000 fish on a site, a previous history of PD on a site, a high sea lice burden, and sites located in the western regions of Ireland which reared a specific strain of salmon.     

Computed tomographic evaluation of canine radioulnar incongruence in vivo

OBJECTIVE: To compare radioulnar incongruence (RUI) of normal canine elbows and elbows with arthroscopically confirmed medial compartment disease in vivo using systematic computed tomography (CT) measurements. STUDY DESIGN: Prospective comparison of RUI measurements in normal and dysplastic canine elbows. SAMPLE POPULATION: Right elbows of 25 medium-large breed, adult dogs with medial compartment disease and 9 medium-large breed, adult dogs with no elbow disease. METHODS: Transverse CT images of proximal radioulnar articulation were reformatted to dorsal and sagittal planes. RUI in 3 locations of the forelimb's medial coronoid was measured. Arthroscopy confirmed diagnosis of medial compartment disease in the diseased group. RUI measurements of the diseased and normal elbows were compared. RESULTS: Cumulative statistical analysis of RUI in all planes revealed no significant difference between the normal and abnormal elbows (P = .61). The abnormal elbows had negative mean RUI at the mid (P = .56) and cranial (P = .24) coronoid regions that were not significantly different from normal elbows and mean positive RUI at the base coronoid that was significantly greater than in normal elbows (P = .00082). CONCLUSION: Canine elbows with established medial compartment disease do not have significant RUI at the medial coronoid region at the time of diagnosis when compared with normal elbows. CLINICAL RELEVANCE: If RUI is a significant factor in the pathophysiology of medial compartment elbow disease in the dog, it does not appear to be present at the time of diagnosis of disease. Ulnar or radial osteotomies do not appear to be indicated for restoration of normal radioulnar articular surface alignment.     

Galaxies, human eyes, and artificial neural networks

The quantitative morphological classification of galaxies is important for understanding the origin of type frequency and correlations with environment. However, galaxy morphological classification is still mainly done visually by dedicated individuals, in the spirit of Hubble's original scheme and its modifications. The rapid increase in data on galaxy images at low and high redshift calls for a re-examination of the classification schemes and for automatic methods. Here are shown results from a systematic comparison of the dispersion among human experts classifying a uniformly selected sample of more than 800 digitized galaxy images. These galaxy images were then classified by six of the authors independently. The human classifications are compared with each other and with an automatic classification by an artificial neural network, which replicates the classification by a human expert to the same degree of agreement as that between two human experts.     

Effects of a synthetic facial pheromone on behavior of cats

OBJECTIVE: TO evaluate the effects of a synthetic feline facial pheromone (FFP) on behavior and food intake of healthy versus clinically ill cats. DESIGN: Original study. ANIMALS: 20 cats were used in each of 2 studies. In each study, 7 cats were considered healthy, and 13 cats were determined to be clinically ill. PROCEDURE: In study 1, cats were assigned either to exposure to FFP (treated group; 4 healthy, 6 ill cats) or to exposure to the vehicle (70% ethanol solution; control group; 3 healthy, 7 ill cats). Cats were placed in a cage containing a small cotton towel that had been sprayed with FFP or vehicle 30 minutes previously. Cats were then videotaped for 125 minutes, and food intake was measured during this period. Videotapes were scored at 5-minute intervals for various behaviors. In study 2, cats were categorized in 1 of 2 groups; group 1 (2 healthy, 8 ill cats) had a cat carrier placed in their cages, and group 2 (5 healthy, 5 ill cats) did not. All cats were exposed to FFP, and 24-hour food intake was measured. RESULTS: Differences between behaviors of healthy versus clinically ill cats were not identified. In the first study, significant increases in grooming and interest in food were found in cats exposed to FFP compared with vehicle. For all cats, significant positive correlations were detected between grooming and facial rubbing, walking and facial rubbing, interest in food and facial rubbing, eating and facial rubbing, grooming and interest in food, and grooming and eating. In the second study, 24-hour food intake was significantly greater in cats exposed to FFP and the cat carrier, compared with cats exposed to FFP alone. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that exposure to FFP may be useful to increase food intake of hospitalized cats.     

Streptococcus suis in slaughter pigs and abattoir workers.

The detection and identification of Streptococcus suis type 2 in 8.1% of 347 pig herds of southwestern Ontario revealed that the infection is widespread in this area. A herd suspected to be infected showed a carrier rate of 9.7% among the 62 animals sampled. These subclinical carriers represent a potential source of infection for slaughterhouse workers. From studies of contamination of hands and knives, it was concluded that eviscerators involved in removing the larynx and lungs from the carcasses have a significantly higher (p less than or equal to 0.05) risk of exposure to Streptococcus suis than other abattoir workers.     

Effect of medicated feed on tracheal infection and population of Mycoplasma gallisepticum in chickens

Six-week-old broilers were fed 50 g tylosin/ton, 400 g chlortetracycline (CTC)/ton, or unmedicated feed and then challenged intratracheally with R strain Mycoplasma gallisepticum (MG). Feed-grade antibiotic medication did not prevent infection, but medication did lower the number of isolations from treated birds compared with controls. Only tylosin significantly lowered MG counts in the trachea. The log10 ID50 of birds receiving tylosin, CTC, or unmedicated feed were 5.8, 4.4, and 2.9, respectively. Six-week-old leghorns were placed on the three diets described previously and challenged with the R strain of MG. Birds were sacrificed at various times up to 10 weeks postchallenge (PC). Compared with the control diet, the tylosin-medicated diet significantly reduced the tracheal MG count from day 1 to 4 weeks PC, whereas the CTC-medicated diet significantly lowered the tracheal MG count only at 3 days PC. In all groups, the MG count gradually declined after 1 week PC; by 8 weeks PC it was essentially the same in all groups. It was concluded that continuous medication has the potential for reducing MG tracheal populations only during the initial phase of an outbreak.     

Comparative effectiveness of two alkylammonium compounds as wood preservatives

This study describes a laboratory evaluation of the efficacy of two alkylammonium compounds [didecyldimethylammonium tetrafluoroborate (DBF) and didecyldimethylammonium chloride (DDAC)] when applied via vacuum impregnation or superficial treatment. Treated wood specimens were tested for their termite and microbial resistance under controlled laboratory conditions. The higher chemical retentions were needed to suppress the feeding by Coptotermes formosanus ≦3% mass loss in the multichoice test than in the no-choice test. The DBF and DDAC retention levels necessary to meet the performance requirement ≦3% mass loss after 12-week fungal exposure varied with wood species. The retention level of 3 kg/m³ for DBF and DDAC was generally high to keep the nondurable wood species free of decay. Although there was no difference between DBF and DDAC in the efficacy against decay and termite attack, the former slightly outperformed the latter as an antimold and antisapstain agent.     

Adenohypophyseal function in bitches treated with medroxyprogesterone acetate

The aim of this study was to investigate the effects of treatment with medroxyprogesterone acetate (MPA) on canine adenohypophyseal function. Five Beagle bitches were treated with MPA (10mg/kg, every 4 weeks) and their adenohypophyseal function was assessed in a combined adenohypophyseal function test. Four hypophysiotropic hormones (CRH, GHRH, GnRH, and TRH) were administered before and 2, 5, 8, and 11 months after the start of MPA treatment, and blood samples for determination of the plasma concentrations of ACTH, cortisol, GH, IGF-1, LH, FSH, prolactin, alpha-MSH, and TSH were collected at -15, 0, 5, 10, 20, 30, and 45 min after suprapituitary stimulation. MPA successfully prevented the occurrence of estrus, ovulation, and a subsequent luteal phase. MPA treatment did not affect basal and GnRH-induced plasma LH concentrations. The basal plasma FSH concentration was significantly higher at 2 months after the start of MPA treatment than before or at 5, 8, and 11 months after the start of treatment. The maximal FSH increment and the AUC for FSH after suprapituitary stimulation were significantly higher before treatment than at 5, 8, and 11 months of MPA treatment. Differences in mean basal plasma GH concentrations before and during treatment were not significant, but MPA treatment resulted in significantly elevated basal plasma IGF-1 concentrations at 8 and 11 months. MPA treatment did not affect basal and stimulated plasma ACTH concentrations, with the exception of a decreased AUC for ACTH at 11 months. In contrast, the maximal cortisol increment and the AUC for cortisol after suprapituitary stimulation were significantly lower during MPA treatment than prior to treatment. MPA treatment did not affect basal plasma concentrations of prolactin, TSH, and alpha-MSH, with the exception of slightly increased basal plasma TSH concentrations at 8 months of treatment. MPA treatment did not affect TRH-induced plasma concentrations of prolactin and TSH. In conclusion, the effects of chronic MPA treatment on adenohypophyseal function included increased FSH secretion, unaffected LH secretion, activation of the mammary GH-induced IGF-I secretion, slightly activated TSH secretion, suppression of the hypothalamic-pituitary-adrenocortical axis, and unaffected secretion of prolactin and alpha-MSH.     

Estimating stand transpiration in a Eucalyptus populnea woodland with the heat pulse method: measurement errors and sampling strategies

Sap flow measurement techniques, such as the heat pulse (compensation) method, are practical means for estimating the water use of individual trees and are often the only reasonable alternative for measuring forest and woodland transpiration in complex heterogeneous terrain. The need to scale estimates of water use from a sample of individual stems to a stand (population) of known area may be satisfied by applying scalars of flux based on tree size or domain. We estimated the aggregate errors in applying the heat pulse technique to the estimation of stand transpiration in a poplar box (Eucalyptus populnea F.J. Muell.) woodland in southeastern Queensland, Australia, by a combination of precision analyses, experimental validation and Monte Carlo simulations of sampling errors. Errors in sap flux density measurements were approximately 13%. The potential error in the flux estimates for individual stems with stratified sampling of sap flux density with depth and bole quadrant based on four sensors was an additional 25%. Conducting wood area, diameter at 1.3 m, leaf area and domain based on Ecological Field Theory all proved excellent scalars of flux at the stand level. With a sample size of six trees stratified by diameter, coefficients of variation in scaling to the stand level were approximately 5% for any of these scalars. The greatest potential source of error in estimating stand transpiration by the heat pulse method was in the measurement of the fluxes of individual stems; scaling these measurements to a homogeneous stand of trees involved less uncertainty.