Concentrations of Pb, Cd, As, Sb, and Se in peat from 21 ombrotrophic bogs in Norway are discussed with respect to air pollution and compared to other evidence from studies of trace element deposition in Norway. In general the data support conclusions from studies of atmospheric deposition based on moss analysis, and they also confirm specific trends previously observed for the contamination of natural surface soils with these elements. Lead, Cd, As, and Sb all are strongly enriched in the surface peat layers, indicating significant atmospheric input all over the country. In the south the concentrations in the surface peat are about 10 times higher than in the central and northern part of the country, supporting previous evidence of substantial input from source regions in other European countries. For Se there is also a component of anthropogenic input in the south, but this contribution from long range transport is superimposed on a very distinct coast - inland gradient all along the west coast, strongly suggesting atmospheric supply of Se from the marine environment. 相似文献
The effects of head position on internal carotid artery (ICA) and external carotid artery (ECA) pressures in standing sedated horses were evaluated in this study. The common carotid artery (CCA) was catheterized in 6 horses using an ultrasound-guided technique to facilitate placement of a pressure transducer within the ICA and ECA at the level of the guttural pouch. Transducer position was confirmed by endoscopic visualization. Mean arterial pressure (MAP) was measured with horses in both a head-up and head-down position. The dorsal metatarsal artery was catheterized as a control. Maintaining a head-up position decreased MAP in both the ICA (median: 75.21 mmHg) and ECA (median: 79.43 mmHg), relative to the head-down position (ICA median: 104.65 mmHg; ECA median: 102.26 mmHg). Mean arterial pressure in the dorsal metatarsal artery was not affected by head position. The head-up position resulted in lower arterial pressures in both the ICA and ECA (P = 0.03) compared with the head-down position in standing sedated horses. 相似文献
Seed buyers desire a conservatively low field certification rate (to better protect their industry). In contrast, seed growers want a relatively higher field certification rate (to reduce their costs in cultural practices which protect against disease). Sampling error requires 1) the grower’s “aimed-for” disease rate to be lower than 2) the agency specified field certification rate, which in turn must be lower than 3) the disease rate which the buyer would find “utterly” unacceptable. Since sample size determines sampling error, it also determines the amount by which the grower must aim to set rate 1) below that of rate 3) to reach reasonable likeliness for his field to be accepted. That is, in a sense, sample size determines the spread between rates 1) and 3). Formula, tables and graphs herein, for given probabilities of error, illustrate the relation between sample size and the required spread in disease rates 1) and 3) where spread is treated as the ratio of rate 1) to rate 3). Such can be useful to certification agencies in making decisions upon sample size requirements for determining field certification. 相似文献
Changes in the Hounsfield Unit value of adipose tissue and of non-adipose soft tissue during growth are poorly documented. This study examines the HU of these tissues in growing pigs. Computer tomography scans were made in nine growing pigs on three occasions, approximately four weeks apart. Average body weight was 51, 94, and 121 kg for each successive scan. Images from the level of the diaphragm to the hips were analyzed. The mean HU and its standard deviation, for adipose tissue and for non-adipose soft tissues was determined for each pig. The mean adipose tissue HU for all pigs was -90, -98 and -101 on the first, middle and last scans, respectively. Corresponding HU values for non-adipose soft tissues were, 52, 51 and 49. There was a significant difference (p<0.01) between HU at each scan time for each set of tissues. 相似文献
Florfenicol, a drug effective against several bacterial diseases of fish, was tested for possible immunomodulatory effects. The aim of the study was to follow the kinetics of the immune response after vaccination with simultaneous oral antibiotic treatment. The fish were immunised with a commercial oil-based divalent (furunculosis/vibriosis) vaccine and were simultaneously given oral antibiotic treatment. The specific immune response was monitored by analysing the levels of specific antibodies with ELISA. As an indicator of the non-specific immune response the phagocytic activity of circulating leucocytes was measured by a chemiluminescence assay. Total circulating leucocyte counts and differentials were also monitored. The disease resistance was evaluated by challenge tests at the end of the experiment. The results showed that florfenicol did not have any significant effect on antibody production and circulating leucocyte levels but caused a suppression in chemiluminescence response/phagocytic cell 5-6 weeks after vaccination. The survival after challenge was slightly suppressed by the florfenicol treatment. The RPS-value for the vaccinated group was 98% and for the florfenicol-treated group was 88%. 相似文献
1. The performance of the scoring in the Danish footpad dermatitis (FPD) surveillance system was evaluated by determining inter-rater agreement in visual inspection of FPD in broilers between two independent raters (R1 and R2) and the official scoring at a Danish slaughterhouse.
2. FPD scores were evaluated in 1599 chicken feet. The two raters and the slaughterhouse scored equal proportions of score 0. So did R1 and R2 when assessing score 1 and the more severe lesion score 2, whereas the slaughterhouse scored a markedly higher proportion of score 1 and a lower proportion of score 2. Aggregated FPD flock scores ranged from 5 to 163 (R1 and R2) and from 8 to 107 (slaughterhouse).
3. The level of agreement between the two raters was high for scores 0, 1 and 2 and for flock scores. Agreement between raters and the slaughterhouse was lower when R1 and R2 recorded score 2 than when they recorded scores 0 and 1.
4. This study indicates that the occurrence and severity of lesions are underestimated in the official Danish FPD scoring system. 相似文献
Fur quality and skin size are integral qualities in the mink industry and are main determinants of sales price and subsequent income for mink fur producers. Parental animals of future generations are selected based on quality grading from live animals, but selection response is obtained from dried skins sold after pelting. In this study, we evaluated traits assessed during live grading and pelt traits examined on dried skins to determine correlation between live and pelt traits. Grading traits and body weight were measured during live animal grading for 9,539 Brown American mink, and pelt quality traits and skin size were evaluated on 8,385 dried mink skins after pelting. Data were sampled from 2 yearly production cycles. Genetic parameters were estimated using the REML method implemented in the DMU package. Heritabilities and proportions of litter variance were calculated from estimated variance components for all traits, and genetic and phenotypic correlations between all traits were estimated in a series of bivariate analyses. Heritability estimates for live grading traits ranged from 0.06 to 0.28, heritability estimates for pelt quality traits ranged from 0.20 to 0.30, and finally heritability estimates for body size traits ranged from 0.43 to 0.48. Skin size and body weight were regarded as different traits for the two sexes and were therefore analysed for each sex separately. Genetic correlations between grading traits exhibited a range of 0.30–0.99 and genetic correlations between pelt quality traits ranged from 0.38 to 0.86. Genetic correlations between quality, wool density and silky appearance evaluated during live animal grading and on dried skin after pelting were 0.74, 0.41 and 0.33, respectively. Skin size and body weight were negatively correlated with pelt quality traits and ranged from −0.55 to −0.25. Using standard selection index theory and combined information from both live grading and skin evaluation increase of reliability of selection ranged from 0.6% to 14%. Due to moderate genetic correlations between traits evaluated during live grading and on dried skins, and negative correlations between pelt quality traits and body size, we concluded that traits should be selected simultaneously. 相似文献
Protection against lipid oxidation and formation of unpleasant fishy and rancid off-flavors in oil-in-water food emulsions, such as fish oil enriched mayonnaise, is difficult to achieve. Volatile profiles from stored mayonnaises with different oil phase compositions were collected using a developed dynamic headspace sampling technique, in which interfering acetic acid was removed in situ with potassium hydroxide, and subsequently 148 volatiles were characterized and monitored by gas chromatography/mass spectrometry. Multivariate statistics showed correlation between the concentration of 62 volatiles and the fish oil and storage parameters, indicating the formation of lipid oxidation products, which impose fishy off-flavors. Further verification was obtained by gas chromatography/olfactometry, by which, among 78 odors, cis-4-heptenal and trans,cis-2,4-heptadienal were detected as distinct fishy notes. In total, 27 volatiles, including 1-penten-3-one, cis-2-penten-1-ol, cis-3-hexenal, cis-4-heptenal, 1-octen-3-one, 1,cis-5-octadien-3-one, 1-octen-3-ol, trans,cis-2, 4-heptadienal, and trans,cis-2,6-nonadienal, were suggested to contribute to the developed unpleasant fishy and rancid off-flavors. 相似文献