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951.
There is now a strong consensus that during the 20th century, and especially during recent decades, the earth has experienced a significant warming trend with projections suggesting additional further warming during the 21st century. Associated with this warming trend are changes in climate that are expected to show substantial spatial variability across the earth's surface. Globally, fish production has continued to increase during recent years at a rate exceeding that of human population growth. However, the contribution from capture fisheries has remained largely static since the late 1980s with the increase in production being accounted for by dramatic growth in the aquaculture sector. In this study, the distribution of vulnerability of aquaculture‐related livelihoods to climate change was assessed at the global scale based on the concept of vulnerability as a function of sensitivity to climate change, exposure to climate change and adaptive capacity. Use was made of national‐level statistics along with gridded climate and population data. Climate change scenarios were supplied using the MAGICC/SCENGEN climate modelling tools. Analysis was conducted for aquaculture in freshwater, brackish and marine environments with outputs represented as a series of raster images. A number of Asian countries (Vietnam, Bangladesh, Laos and China) were indicated as most vulnerable to impacts on freshwater production. Vietnam, Thailand, Egypt and Ecuador stood out in terms of brackish water production. Norway and Chile were considered most vulnerable to impacts on marine production while a number of Asian countries (China, Vietnam and the Philippines) also ranked highly. 相似文献
952.
B J Shreeve J G Matthews G A Wells D S Patterson H M Ross R D Watson W J Smith 《The Veterinary record》1983,113(5):102-104
The introduction of a new batch of feed to 400 pigs aged five to eight weeks resulted in 38 deaths and further morbidity associated with multiple haemorrhages. Signs abated within two days of withdrawal of the feed. Widespread haemorrhages were present in many tissues including the pancreas. Additional pancreatic lesions comprised focal necrosis, atrophy and fibrosis of exocrine tissue. The condition was reproduced experimentally in pigs and vitamin K protected mice against the injurious effects of the feed. The cause was not determined but it is speculated that more than one toxic factor and an imbalance of nutritional factors may have been present in the diet. 相似文献
953.
954.
Modelling mould growth on coated modified and unmodified wood substrates exposed outdoors 总被引:2,自引:0,他引:2
Mould growth on coated wood is today a genuine challenge for house owners. Environmentally sound wooden facades with long
service lives and acceptable appearance are desired. The objective in this study was to investigate the accumulated mould
growth on 13 different wood substrates with 3 surface coating systems by identifying the factors that contribute to the variation
and to predict future performance. A generalized linear mixed model was fit to the data with the analysis showing that coating
and exposure time both had highly significant influences on mould growth. Further, wood substrate was significant, but comparatively
less than coating and exposure time. A smaller coefficient for mould coverage in the beginning of the exposure period gave
the panels with one of the coating systems, BAP, a delay in mould growth, and the extrapolated values for years 6–12 indicate
a longer aesthetic service life than panels with the two other coating systems. Coated heartwood as wood type was less susceptible
to mould growth than coated mixed wood and coated sapwood. Acetylated pine as wood substrate and aspen as wood species had
lower resistance to mould growth than the other wood substrates and wood species, respectively. 相似文献
955.
Ross MW Ducharme NG Power HT 《The Canadian veterinary journal. La revue veterinaire canadienne》1983,24(5):150-151
An acute intestinal obstruction caused by a torsion of the descending colon with incarceration and strangulation of the apex of the cecum was diagnosed in a mature Holstein cow. The clinical signs manifested were acute anorexia, depression, signs of abdominal pain, and absence of feces. Rectal examination revealed a sharp decrease in luminal size of the descending colon and taut bands at that level. The final diagnosis was obtained by exploratory celiotomy. Although surgical correction was attempted, the cow died of acute fecal peritonitis 18 hours postoperatively.
Acute intestinal obstruction caused by torsion of the descending colon in the cow has not been reported in the literature.
相似文献956.
Colin Cameron Richard Gurure Konda Reddy Richard Moccia & John Leatherland 《Aquaculture Research》2002,33(6):383-394
Sexually immature Arctic charr, Salvelinus alpinus (Linnaeus), were fed one of five isoenergetic practical diets of differing lipid:protein ratios (0.98, 0.67, 0.41, 0.26, 0.19) for an 84‐day period to examine the influence of diet composition on growth, and growth hormone (GH) and thyroid hormone physiology. All five diets supported growth at approximately the same rate, but the diet with a lipid:protein ratio of 0.98 had the lowest weight gain and highest food conversion ratios. A GH enzyme‐linked immunosorbent assay (ELISA), developed for use with oncorhynchid fishes, was validated for use with Arctic charr. Plasma GH concentrations were significantly higher in fish fed the diet with a lipid:protein ratio of 0.98, and there were significant direct and inverse correlations between plasma GH levels and dietary lipid and protein content respectively. There were no significant differences in pre‐ and post‐prandial plasma GH concentrations for any group. There were significant post‐prandial elevations of plasma triiodothyronine (T3) and thyroxine (T4) for fish fed the lower lipid:protein ratio diets, but there were no differences related to the diets. The results are discussed in terms of GH as a factor in the regulation of lipid and protein homeostasis in fishes. 相似文献
957.
958.
Objective— To determine if the clinically practiced method of radiographic femoral varus angle (R-FVA) measurement is repeatable, reproducible, and accurate.
Study Design— Radiographic and anatomic study.
Animals/Sample Population— Normal Walker hound cadavers (n=5) and femora (n=10).
Methods— Cadavers were held in dorsally-recumbent and torso-elevated positions as 3 craniocaudal radiographs were made of each femur, by each of 2 different technicians. Femora were then harvested for direct measurement of anatomic femoral varus angle (A-FVA). R-FVA was measured on each radiograph by each of 3 examiners on 3 separate occasions. Intra-observer (repeatability) and inter-observer (reproducibility) variance in R-FVA measurement and the strength of relationship between R-FVA and A-FVA (accuracy) were determined.
Results— Mean (±SD) A-FVA was 5.2±2.1° (range, 2.4–8.2°). Mean (±SD) R-FVA was 5.8±1.0° (range, 2.7–9.6°). Intra-observer variance (range: 11–16%) and inter-observer variance (16%) were acceptable. The strength of relationship between measured R-FVA and A-FVA (maximum adjusted R2 <0) was unacceptably low regardless of observer, patient position, or radiographic technician.
Conclusion— R-FVA measurement was repeatable and reproducible, but not statistically accurate in predicting A-FVA in these 5 normal Walker hounds. The detected inaccuracy may be real or the result of a selection bias for normal dogs obscuring the true relationship.
Clinical Relevance— R-FVA may not be an accurate method of femoral varus measurement in dogs with A-FVA<10°. Using Slocum's criteria for distal femoral osteotomy (R-FVA>10°), the procedure would not have been erroneously performed in any of the normal dogs of this study. 相似文献
Study Design— Radiographic and anatomic study.
Animals/Sample Population— Normal Walker hound cadavers (n=5) and femora (n=10).
Methods— Cadavers were held in dorsally-recumbent and torso-elevated positions as 3 craniocaudal radiographs were made of each femur, by each of 2 different technicians. Femora were then harvested for direct measurement of anatomic femoral varus angle (A-FVA). R-FVA was measured on each radiograph by each of 3 examiners on 3 separate occasions. Intra-observer (repeatability) and inter-observer (reproducibility) variance in R-FVA measurement and the strength of relationship between R-FVA and A-FVA (accuracy) were determined.
Results— Mean (±SD) A-FVA was 5.2±2.1° (range, 2.4–8.2°). Mean (±SD) R-FVA was 5.8±1.0° (range, 2.7–9.6°). Intra-observer variance (range: 11–16%) and inter-observer variance (16%) were acceptable. The strength of relationship between measured R-FVA and A-FVA (maximum adjusted R
Conclusion— R-FVA measurement was repeatable and reproducible, but not statistically accurate in predicting A-FVA in these 5 normal Walker hounds. The detected inaccuracy may be real or the result of a selection bias for normal dogs obscuring the true relationship.
Clinical Relevance— R-FVA may not be an accurate method of femoral varus measurement in dogs with A-FVA<10°. Using Slocum's criteria for distal femoral osteotomy (R-FVA>10°), the procedure would not have been erroneously performed in any of the normal dogs of this study. 相似文献
959.
Nitrous oxide (N2O) is a potent greenhouse gas, which is mainly produced from agricultural soils. Ammonia oxidation is the rate‐determining step in N2O production, and the process is carried out by ammonia oxidizers, bacteria and archaea. Soil aggregate size has been shown to alter soil properties, which affect N2O emissions and bacterial communities. However, the effect of aggregate size on temporal and total N2O emissions and ammonia‐oxidizing bacteria (AOB) and archaea (AOA) is not fully understood. This incubation study investigated the effect of three different soil aggregate sizes on N2O emissions and ammonia oxidizer abundance under high urine‐N concentrations and the effectiveness of a nitrification inhibitor, dicyandiamide (DCD), at reducing N2O emissions in different aggregate soils. It was found that temporal patterns of N2O emissions were affected by aggregate size with higher peak emissions in the large and medium aggregates. However, the total emissions were the same due to a ‘switch’ in emissions at day 66, after which smaller aggregates produced higher N2O emissions. It is suggested that the switch was caused by an increase in aggregate disruption in the small aggregates, following the urine application, due to their higher surface area to volume ratio. AOB and AOA abundances were not significantly affected by aggregate size. DCD was effective in reducing N2O emissions in all aggregate sizes by an average of 79%. These results suggest that similar ammonia oxidizer abundance is found in soils of different aggregate sizes, and the efficacy of DCD in reducing N2O emissions was not affected by aggregate size of the soil. 相似文献
960.