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排序方式: 共有85条查询结果,搜索用时 31 毫秒
1.
Iversen LL 《Science (New York, N.Y.)》1984,225(4669):1468
2.
Christopher Marlowe A Caipang Monica F Brinchmann Ingvild Berg Martin Iversen Robert Eliassen Viswanath Kiron 《Aquaculture Research》2008,39(14):1533-1540
Using Atlantic cod, Gadus morhua, as a model for the stress response in gadoid fish, the changes in the expression of some stress and immune genes as well as the profiles of plasma cortisol were examined. Adult fish were kept at a density of ca. 100 kg m?3 by lowering the water level in the rearing tank for 1 h and this short‐term crowding stress was repeated thrice over a 12‐h interval period. Blood samples were collected before exposure and at 2, 24 and 72 h post crowding. Plasma cortisol level significantly increased at 2 h post crowding but returned to pre‐crowding levels 24 h after exposure. The relative expression of the stress response genes, glucose transporter‐3 and a putative heat shock protein 70 significantly increased at 2 and 24 h post crowding respectively. Significant up‐regulation of the pro‐inflammatory cytokines, interleukin (IL)‐1β and IL‐8, as well as anti‐bacterial genes, g‐type lysozyme and bactericidal permeability‐increasing protein/lipopolysaccharide‐binding protein (BPI/LBP) was also observed at 2 h and the levels were maintained until 72 h post exposure, except for BPI/LBP which had maximum up‐regulation at 24 h. The present observations have implications with respect to fish welfare and assessment of the health status of the farmed fish. 相似文献
3.
Pedersen HD Häggström J Falk T Mow T Olsen LH Iversen L Jensen AL 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》1999,13(1):56-64
Observer variation in diagnosing mild mitral regurgitation in dogs by cardiac auscultation was assessed by having 6 veterinarians with different levels of experience examine 57 Cavalier King Charles Spaniels. Comparisons with color Doppler echocardiography and phonocardiography were made, and the effects of 2 physical maneuvers on the auscultatory findings were evaluated. Using mildly diseased dogs, interobserver agreement in diagnosing the presence or absence of left-sided murmurs ranged from 63% to 88%. The agreement with phonocardiography (range, 53-91%) increased with the amount of observer experience. The 2 most experienced observers could discern soft ejection murmurs from regurgitant murmurs and were able to diagnose 89% of the dogs with regurgitant jets larger than 30% of the left atrial area. In general, less experienced observers diagnosed most jets larger than 50%. In many dogs with small jets, no murmur was found by auscultation and phonocardiography. The audibility of mild regurgitation was significantly reduced in dogs that were difficult to auscultate. Early systolic murmurs were typical of mild regurgitation, whereas holosystolic murmurs typified severe regurgitation. In a few dogs, late systolic murmurs alternated with holosystolic murmurs. Systolic clicks were found phonocardiographically in 18 dogs with mild to moderate regurgitation, but the audibility apparently was low. In many mildly affected dogs, physical maneuvers increased murmur intensity. Thus, some form of dynamic auscultation might facilitate the diagnosis of mild regurgitation. Auscultatory findings in mild regurgitation appear to depend on observer experience, circulatory status, and how difficult the dog is to auscultate. 相似文献
4.
Rohloff J Skagen EB Steen AH Iversen TH 《Journal of agricultural and food chemistry》2000,48(12):6205-6209
In 1996, the production of Achillea millefolium L. at different locations in Norway was investigated with regard to the developmental stage. The oil content differed greatly between the vegetative stage (0.13%) and the stage of full bloom (0.34%). Changes in the composition of yarrow essential oil were found to be related to maturation of the plant, with increasing amounts of monoterpenes in relation to the sesquiterpene. However, a clear trend could be detected only for the monoterpenic compounds with increasing levels of alpha- and beta-pinene and alpha-thujone and decreasing levels of sabinene, borneol, and bornyl acetate. Previously reported as major compounds, chamazulene and germacrene D could be found only in insignificant amounts. A solid-phase microextraction (SPME) procedure was applied for screening of the terpenic composition. Sesquiterpenic compounds such as beta-bisabolene, alpha-bisabolol, and delta-cadinene were detected in substantial amounts by SPME in contrast to the steam-distilled samples. 相似文献
5.
L Iversen A.L Jensen R Høier M Skydsgaard F Kristensen 《Domestic animal endocrinology》1998,15(6):525-536
An enzyme-linked immunosorbent assay to detect thyroglobulin autoantibodies (TGAB) in canine serum was developed and validated. The test result for each sample was derived from the optical density readings (OD) and expressed as an Ab-score(%) calculated from three in-house calibrators. The assay specifically detected TGAB as judged from lack of response in the assay after samples had been incubated with specific antigen. Intra- and interassay coefficients of variation ranged from 2.0–4.9% and 4.6–9.9%, respectively. The detection limit, an Ab-score of 5.6%, was close to the median Ab-score of 10% observed in healthy dogs (n = 132). The median Ab-score of dogs with primary hypothyroidism and lymphocytic thyroiditis (n = 11), skin diseases (n = 35), and non-thyroidal diseases (n = 63) was 340%, 12%, and 8%, respectively. The prevalence of TGAB in hypothyroid dogs with lymphocytic thyroiditis (sensitivity) was 91% (95% confidence limits: 59%–99%). In dogs with dermatological diseases without lymphocytic thyroiditis the prevalence of TGAB was 3% corresponding to a specificity of 97% (95% confidence limit: 85%–100%). In dogs with non-thyroidal diseases and healthy dogs the prevalence of TGAB was 5% and 6%, respectively. The diagnostic accuracy of serum TGAB was evaluated by subjecting the data from 11 dogs with lymphocytic thyroiditis and 35 control dogs without lymphocytic thyroiditis to receiver-operating characteristic curve analysis. The area under the receiver-operating characteristic curve (W = 0.966; 95% confidence limit 87%–100%) was significantly higher than that of a worthless test (0.5) (P < 0.0001), thereby indicating that serum TGAB measurements distinguished between dogs with and without lymphocytic thyroiditis. 相似文献
6.
鳀鱼的生物量、渔业及其生物学特征 总被引:1,自引:0,他引:1
Svein A. Iversen Arne Johannessen Jin Xianshi Li Fuguo Zhao Xianyong Institute of Marine Research Bergen Institutes of Fisheries Marine Biology University of Bergen Yellow Sea Fisheries Research Instit 《海洋水产研究》2001,22(4)
IntroductionThe Yellow Sea is characterized by a shallow continental shelf. High tides and seasonally varying mon-soons,freshwater discharge from surrounding landmasses and large amounts of sediments transported intothe sea as well as the effect of the Kuroshio current have strong effects on the environment in these areas.Productivity of an ecosystem may be measured in terms of abundance of the adult population and recruitmentof new year classes.Japanese anchovy(Engraulis jap onicus) is cons… 相似文献
7.
[目的]考察浸矿剂硫酸铵(NH4)2SO4胁迫下稀土离子钇的毒性研究。[方法]选择蚯蚓作为土壤生态环境污染指示生物,采用滤纸接触法研究硫酸铵胁迫下稀土钇( Y)对蚯蚓的急性毒性效应。[结果]①稀土钇单一染毒,蚯蚓的48 h 半致死率浓度为 LC50=213.41 mg/L、24 h半致死率浓度为 LC50=322.63 mg/L。②硫酸铵单一染毒下,蚯蚓的48 h半致死率浓度为 LC50=13.89 g/L、24 h半致死率浓度为LC50=15.05 g/L。③低浓度10 g/L的硫酸铵与稀土钇复合染毒,蚯蚓的48 h半致死率浓度LC50=198.65 g/L、24 h 半致死率浓度 LC50=399.85 g/L;中浓度14 g/L的硫酸铵与稀土钇复合染毒,蚯蚓的48 h半致死率浓度 LC50=167.3 mg/L、24 h半致死率浓度 LC50=256.73 mg/L;高浓度20 g/L的硫酸铵与稀土钇复合染毒,蚯蚓的48 h半致死率浓度 LC50=31.03 mg/L、24 h的LC50=127.65 mg/L。[结论]低浓度的硫酸铵降低稀土钇对蚯蚓的毒性,产生一定的拮抗作用。中浓度的硫酸铵增加稀土钇对蚯蚓的毒性,产生较明显的协同作用。高浓度硫酸铵显著增加了稀土钇对蚯蚓的毒性。稀土钇染毒下蚯蚓死体更易断裂,而活体对针刺反应相对不灵敏。 相似文献
8.
A. L. Jensen L. Iversen J. Koch R. Høier† † T. K. Petersen 《The Journal of small animal practice》1997,38(3):99-102
The diagnostic accuracy of the urinary cortisol:creatinine ratio (CCR), with the cortisol being measured by ELISA, was evaluated by subjecting data from 18 dogs with and 20 dogs without hyperadrenocorticism to recelver operating characteristic (ROC) curve analysis. The area under the ROC curve (W 0–93, SEw 0–044) was much higher than 045, indicating that the CCR did distinguish between dogs with and without hyperadrenocorticism.A cutoff value of about 60 × 10-6 was assoclated with the highest sensitivity (1.0)and speciflcity (0–85). At the disease prevalence rate of the present study (0 47), the positive and negative predictive values were 0–87 and 1.0, respectively. These numbers indicate that canine hyperadrenocorticism may be safely excluded when the CCR Is below 60 × 10-6 but that a test of higher specificlty (eg, the ACTH stimulation test) should be used to confirm the diagnosis of canine hyperadrenocorticism when the CCR Is above 60 × 10-6 . 相似文献
9.
Wind tunnel experiments have revealed a characteristic flow field pattern over raised-rim craters which causes distinctive zones of aeolian erosion and deposition. Comparisons of the results with Mariner 9 images of Mars show that some crater-associated dark zones result from wind erosion and that some crater-associated light streaks are depositional. 相似文献
10.
Iversen M Kirychuk S Drost H Jacobson L 《Journal of agricultural safety and health》2000,6(4):283-288
Work in swine and poultry units is associated with exposure to significant levels of organic dust and endotoxins with the highest concentrations found in poultry houses, whereas values found in dairy and in cattle farming are much lower. Corresponding to this is an excess of work-related respiratory symptoms in swine farmers. A dose-response relationship exists between symptoms and number of working hours. Longitudinal studies have demonstrated an accelerated decline of lung function in swine farmers large enough to cause clinically significant disease in some farmers. Because of the large number of people needed in swine farming and the long working hours, swine farming has emerged as the major respiratory problem in farming. Experimental studies indicate that exposure has to be lowered substantially to avoid acute effects and longitudinal studies demonstrate that loss of lung function occurs in non-smoking swine farmers without respiratory symptoms and that accelerated decline in lung function occurs below endotoxin concentrations in dust (100 ng/m3) proposed as a safe threshold. 相似文献