Oceanographic investigation of the American Samoa albacore (Thunnus alalunga) habitat and longline fishing grounds   总被引：1，自引：0，他引：1  

RÉKA DOMOKOS  MICHAEL P. SEKI  JEFFREY J. POLOVINA  DONALD R. HAWN 《Fisheries Oceanography》2007,16(6):555-572

The American Samoa fishing ground is a dynamic region with strong mesoscale eddy activity and temporal variability on scales of <1 week. Seasonal and interannual variability in eddy activity, induced by baroclinic instability that is fueled by horizontal shear between the eastward‐flowing South Equatorial Counter Current (SECC) and the westward‐flowing South Equatorial Current (SEC), seems to play an important role in the performance of the longline fishery for albacore. Mesoscale eddy variability in the American Samoa Exclusive Economic Zone (EEZ) peaks from March to April, when the kinetic energy of the SECC is at its strongest. Longline albacore catch tends to be highest at the eddy edges, while albacore catch per effort (CPUE) shows intra‐annual variability with high CPUE that lags the periods of peak eddy activity by about 2 months. When CPUE is highest, the values are distributed toward the northern half of the EEZ, the region affected most by the SECC. Further indication of the possible importance of the SECC for longline performance is the significant drop in eddy variability in 2004 when compared with that observed in 2003 – resulting from a weak SECC – which was accompanied by a substantial drop in albacore CPUE rates and a lack of northward intensification of CPUE. From an ecosystem perspective, evidence to support higher micronekton biomass in the upper 200 m at eddy boundaries is inconclusive. Albacore's vertical distribution seems to be governed by the presence of prey. Albacore spend most of their time between 150 and 250 m, away from the deep daytime and shallow nighttime sonic scattering layers, at depths coinciding with those of small local maxima in micronekton biomass whose backscattering properties are consistent with those of albacore's preferred prey. Settling depths of longline sets during periods of decreased eddy activity correspond to those most occupied by albacore, possibly contributing to the lower CPUE by reducing catchability through rendering bait less attractive to albacore in the presence of prey.  相似文献   

The significance of a major outbreak of quarantinable disease to the Australian horse industries     

RF CLEMENT  KA DOYLE  JG MURRAY 《Australian veterinary journal》1990,67(2):77-78

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Blood pressure, electrocardiogram and echocardiogram measurements in the growing pony foal     

C W Lombard  M Evans  L Martin  J Tehrani 《Equine veterinary journal》1984,16(4):342-347

Twelve newborn pony foals underwent cardiovascular examinations (auscultation, arterial blood pressure measurements, electrocardiograms and M-mode echocardiograms) on their first day of life and then on Days 7, 14, 21, 30, 60 and 90. An age dependent, statistically significant, rapid increase of the arterial blood pressure in the first month was documented together with a slower decrease of the resting heart rate after two and three months of life. Innocent soft systolic murmurs were audible over the left heart base in a large number of the foals. The electrocardiograms showed age dependent increases of the PR-, QRS- and QT- intervals and a trend of the mean electrical axis in the frontal plane to rotate towards the left side. The ventricular dimensions, measured by M-mode echocardiography, increased with the growth of the pony foals. Linear regression equations were calculated for the right and left ventricular internal dimensions in relation to body weight (bwt). The other echocardiographic parameter had low correlations with bwt.  相似文献   

Duration of the persistent activity of moxidectin against Haemonchus contortus in sheep     

KA ABBOTT  RM COBB†  M HOLM GLASS† 《Australian veterinary journal》1995,72(11):408-410

SUMMARY Weaned lambs were infected with Haemonchus contortus 35,28,21,14 and 7 days after treatment with moxidectin at 0.2 mg/kg and 35 and 14 days after treatment with ivermectin at the same dose rate. Worm counts 14 days after infection showed that moxidectin prevented the establishment of over 99% of infective larvae for 28 days and reduced the establishment rate at 35 days by 96%, relative to ivermectin. There was no difference in the protective efficacy of ivermectin at 14 or 35 days. The persistence of moxidectin is likely to provide advantages in nematode control, particularly when used as a strategic early summer treatment or as a pre-lambing treatment to ewes. Implications of the persistent activity of moxidectin for the development of resistance during the decay phase are discussed.  相似文献   

The effect of monensin on the chemotactic function of bovine neutrophils     

KA STEPHENSON  IJ LEAN  TJ O'MEARA 《Australian veterinary journal》1996,74(4):315-317

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Evaluation of gastric motility in nine dogs before and after prophylactic laparoscopic gastropexy: a pilot study     

KA Coleman  P Boscan  L Ferguson  D Twedt  E Monnet 《Australian veterinary journal》2019,97(7):225-230

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Stabilisation of periarticular fractures and osteotomies with a notched head locking T‐plate          下载免费PDF全文

CJ Tan  KA Johnson 《Australian veterinary journal》2016,94(10):377-383

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Fire cycle of the Canada's boreal region and its potential response to global change     

ZHANG Quan-fa  CHEN Wen-jun .Wuhan Botanical Garden  Chinese Academy of Sciences  Wuhan  P. R. China .Applications Division  Canada Centre for Remote Sensing  Booth Street  Ottawa  Ontario KA Y  Canada 《林业研究》2007,(1)

Interactions of fire cycle and plant species' reproductive characteristics could determine vegetation distribution pattern of a landscape. In Canada's boreal region, fire cycles before the Little Ice Age (c. 1850s) ranged from 30-130 years and 25-234 years afterwards until the settlement period (c. 1930s) when longer fire cycles occurred in response to climatic change and human interference. Analysis indi-cated that fire cycles were correlated with growing season (April-October) temperature and precipitation departure from the 1961-1990 nor-mal, varying by regions. Assuming that wildfires will respond to future warming similar to the manner during the past century, an assess-ment using climatic change scenarios CGCM1, CGCM2 and HadCM2 indicates fire cycles would divert to a range of 80-140 years in the west taiga shield, more than 700 years for the east boreal shield and east taiga shield, and 300-400 years for the boreal plains in 2050.  相似文献   

The persistence of foot-and-mouth disease virus on wool   总被引：1，自引：0，他引：1  

KA McCOLL  HA WESTBURY  RP KITCHING†  VM LEWIS 《Australian veterinary journal》1995,72(8):286-292

SUMMARY Five Suffolk sheep, held in a high-security isolation room, were exposed for 2 hours to the aerosol of 3 mature pigs that had been infected with foot-and-mouth disease virus (FMDV), strain O₁-BFS. The fleeces of 3 of the sheep were contaminated with FMDV at 2 days post exposure (dpe), while at 5 dpe the fleeces of all 5 sheep were more extensively, and more heavily, contaminated. The persistence of FMDV on contaminated wool was examined in vitro using multiple 0.5 g samples of Merino wool that were each contaminated with one of 3 strains of FMDV in tissue-culture medium: O₁-BFS, O-Morocco (O-MOR 9/91) or an Asia 1 strain (TAI 1/90). Wool samples were held at either 4°C, 18°C or 37°C, and decay curves were established for each virus at each temperature. These curves predicted that O₁-BFS, O-MOR 9/91 and TAI 1/90 would fall below detect-able levels at 72, 70 and 48 days post contamination (pc), respectively, for wool stored at 4°C; at 11, 12 and 12 days pc, respectively, for wool stored at 18°C; and at 57, 68 and 33 hours pc, respectively, for wool stored at 37°C. For wool contaminated with O₁-BFS-infected sheep faeces, urine or blood, or with O₁-BFS-infected cattle saliva, decay curves predicted virus to persist for 5 to 11 days pc at 18°C. We demonstrated that the simulated scouring of FMDV-contaminated wool at 60° to 70°C would usually reduce virus to below detectable levels. The detergent component of the scouring process had little, if any, antiviral activity, and scouring at 20°C or 50°C had limited impact on FMDV titres . We recommend that either (1) simple storage of FMDV-contaminated wool for 4 weeks at temperatures of 18°C or higher, or (2) scouring of contaminated wool at 60° to 70°C would be sufficient to remove the threat of FMDV-contaminated wool being infectious to other animals .  相似文献   

盐胁迫下粪产碱菌在水稻根表的定殖(英文)     

伍红  平淑珍  KA Malik  林敏 《核农学报》2000,14(5):305-310

粪产碱菌A1 5 0 1能在氯化钠浓度高达 4%的固体和液体介质中良好生长 ,合成IAA和固定空气中的氮素。当氯化钠浓度超过 3 %时 ,A1 5 0 1丧失运动和趋化能力。一定盐浓度胁迫下A1 5 0 1能定殖在水稻根表和根毛区和侧根伸出部位 ,表现出较高的联合固氮活性。0 5 %的氯化钠能促进A1 5 0 1在水稻根表的定殖能力。A1 5 0 1能通过侧根伸出部位侵入根内。  相似文献