Global assessment of organic contaminants in farmed salmon   总被引：1，自引：0，他引：1  

Hites RA  Foran JA  Carpenter DO  Hamilton MC  Knuth BA  Schwager SJ 《Science (New York, N.Y.)》2004,303(5655):226-229

The annual global production of farmed salmon has increased by a factor of 40 during the past two decades. Salmon from farms in northern Europe, North America, and Chile are now available widely year-round at relatively low prices. Salmon farms have been criticized for their ecological effects, but the potential human health risks of farmed salmon consumption have not been examined rigorously. Having analyzed over 2 metric tons of farmed and wild salmon from around the world for organochlorine contaminants, we show that concentrations of these contaminants are significantly higher in farmed salmon than in wild. European-raised salmon have significantly greater contaminant loads than those raised in North and South America, indicating the need for further investigation into the sources of contamination. Risk analysis indicates that consumption of farmed Atlantic salmon may pose health risks that detract from the beneficial effects of fish consumption.  相似文献   

Earth-Based Radio Tracking of the Galileo Probe for Jupiter Wind Estimation     

WM Folkner  RA Preston  JS Border  J Navarro  WE Wilson  M Oestreich 《Science (New York, N.Y.)》1997,275(5300):644-646

Although the Galileo probe was designed to communicate only to the orbiter, the probe radio signal was detected at two Earth-based radio observatories where the signal was a billion times weaker. The measured signal frequency was used to derive a vertical profile of the jovian zonal wind speed. Due to the mission geometry, the Earth-based wind estimates are less sensitive to descent trajectory errors than estimates based on probe-orbiter Doppler measurements. The two estimates of wind profiles agree qualitatively; both show high wind speeds at all depths sampled.  相似文献   

Chaotic Dynamics in an Insect Population     

RF Costantino  RA Desharnais  JM Cushing  B Dennis 《Science (New York, N.Y.)》1997,275(5298):389-391

A nonlinear demographic model was used to predict the population dynamics of the flour beetle Tribolium under laboratory conditions and to establish the experimental protocol that would reveal chaotic behavior. With the adult mortality rate experimentally set high, the dynamics of animal abundance changed from equilibrium to quasiperiodic cycles to chaos as adult-stage recruitment rates were experimentally manipulated. These transitions in dynamics corresponded to those predicted by the mathematical model. Phase-space graphs of the data together with the deterministic model attractors provide convincing evidence of transitions to chaos.  相似文献   

Effect of Three pFSH Doses on Superovulation and Embryo Quality in Goats During Two Breeding Seasons in North‐eastern Mexico     

F Sánchez‐Dávila  RA Ledezma‐Torres  G Padilla‐Rivas  AS del Bosque‐González  A González Gómez  H Bernal‐Barragán 《Reproduction in domestic animals》2014,49(4):e40-e43

The aim of this research was to evaluate the effectiveness of three pFSH doses (80 mg; 145 mg and 215 mg) on ovarian response and on quantity and quality of transferable embryos of goats during the breeding and the non‐breeding seasons. Ovary structures were exposed (laparatomy under general anaesthesia) and numbers of follicles and corpora lutea were registered. Surgical embryo flushing was conducted to count and classify embryos. There were more follicles (3.4 ± 1.1) in does administered 80 mg of pFSH (p < 0.05) than in goats administered 145 mg of pFSH (2.2 ± 1.1) and 215 mg of pFSH (0.9 ± 0.6). Numbers of corpora lutea, blastocysts, and recovered and transferable embryos of goats administered 145 mg pFSH (13.4 ± 3.7, 2.42 ± 1.0, 3.4 ± 1.2 and 3.2 ± 1.1, respectively) and those of goats administered 215 mg pFSH (11.6 ± 2.6, 3.2 ± 0.9, 5.7 ± 1.5, and 5.6 ± 1.5) were greater (p < 0.05) than values obtained from goats administered 80 mg pFSH (4.0 ± 1.5, 0.5 ± 0.3, 1.0 ± 0.5, and 0.8 ± 0.5). Numbers of morula of does administered 80 and 145 mg pFSH (0.4 ± 0.4 and 0.8 ± 0.3) were lower (p < 0.05) than those obtained from animals treated with 215 mg pFSH (2.4 ± 0.9). There was no effect of season upon the analyzed variables. In conclusion, under the prevalent conditions in north‐eastern Mexico, administration of 145 or 215 mg pFSH in a decreasing dose schedule over 3.5 days to bred goats provided a satisfactory superovulatory result.  相似文献   

Recent studies on the effects of tiamulin and monensin on hepatic cytochrome P450 activities in chickens and turkeys   总被引：1，自引：0，他引：1  

V. RÁTZ  P. LACZAY  ZS. MÓRA  GY. CSIKÓ  K. MONOSTORI  L. VERECZKEY  J. LEHEL  & G. SEMJÉN 《Journal of veterinary pharmacology and therapeutics》1997,20(5):415-418

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Digital dermatitis in a Friesian cow     

MW McLENNAN  RA McKENZIE 《Australian veterinary journal》1996,74(4):314-315

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A simplified fluorescence inhibition test for the serotype determination of Australian bluetongue viruses     

SD BLACKSELL  RA LUNT 《Australian veterinary journal》1996,73(1):33-34

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The PIRLA project (paleoecological investigation of recent lake acidification): Preliminary results for the Adirondacks,New England,N. Great Lakes states,and N. Florida     

Donald F. Charles  Donald R. Whitehead  Dennis S. Anderson  Raymond Bienert  Keith E. Camburn  Robert B. Cook  Thomas L. Crisman  Ronald B. Davis  Jesse Ford  Brian D. Fry  Ronald A. Hites  Jeffrey S. Kahl  John C. Kingston  Russell G. Kreis Jr.  Myron J. Mitchell  Stephen A. Norton  Linda A. Roll  John P. Smol  P. Roger Sweets  Allen J. Uutala  Jeffrey R. White  Mark C. Whiting  Robert J. Wise 《Water, air, and soil pollution》1986,30(1-2):355-365

The PIRLA project is an interdisciplinary paleoecological study designed to provide reconstructions of the recent acidification histories of a representative set of lakes in four acid-sensitive regions in North America. We are trying to determine if lakes in the study regions have acidified, and if so, to what extent, over what time period and why. Sediment cores from 5 to 15 lakes in each region are being analyzed for several characteristics. Diatoms and chrysophytes are being used to reconstruct lakewater pH. Results for three Adirondack lakes with current pH of 4.8 to 5.0 indicate a decrease in pH beginning in the 1930's–1950's. Increased atmospheric deposition of strong acids appears to be the primary factor responsible for the pH decline. Two lakes (pH 4.4 and 4.7) in New England show clear evidence of acidification probably due to acidic deposition. Preliminary reconstructions for two lakes in Michigan (pH 4.4 and 5.6), one in Wisconsin (pH 5.3), and one in Minnesota (pH 6.8) suggest no recent pH decrease. For, the one Florida lake (pH 4.4) analyzed, inferred pH decreases by about 0.5 unit, beginning in the 1950s; the cause has not been determined.  相似文献   

A survey of farmers'' attitudes to services provided by consulting veterinarians to the Western Australian sheep industry     

HM CHAPMAN  RS COPLAND†  RA SWAN  ID ROBERTSON 《Australian veterinary journal》1991,68(6):196-198

A postal survey was conducted of 80 sheep farmers in the Kojonup and Esperance districts of Western Australia to establish what they wanted from a veterinary service. Twenty five of the farmers surveyed used a sheep consultant, 25 did not, and 30 were interested in employing one. Farmers were asked questions about themselves and their attitudes to private veterinarians who provide specialist services to sheep farmers. Data reported here showed that farmers wanted a veterinarian who lived in the district, was well trained in sheep management and production, was enthusiastic and had good communication skills. The service provided should be whole-farm and available to members of the consultant's group only. Regular newsletters and field days were necessary, but the provision of contract services, such as mulesing, lamb-marking, drenching, pregnancy testing and sheep classing, and 'fire-brigade' services for sick animals, were not rated as important. Most farmers were unwilling or unable to give a dollar value for the likely benefits of a consultancy service. Non-financial benefits included keeping farmers up to date with new technical developments and information. The survey also showed that a veterinarian specialising in services to sheep farmers could be confident of employment.  相似文献   

Chronic cervical compressive myelopathy in horses: patterns of astrocytosis in the spinal cord     

JV YOVICH  DH GOULD†  RA LeCOUTEUR† 《Australian veterinary journal》1991,68(10):334-334

The distribution and morphology of fibrous astrocytes in the cervical spinal cord of normal horses and horses with chronic compressive myelopathy were demonstrated using immunohistochemical staining for glial fibrillary acidic protein. In the spinal cord from normal horses, astrocytes with stellate cell bodies and short processes were irregularly distributed in grey matter. In the white matter, their cell bodies were small and angular in areas adjacent to grey matter and larger and more stellate-shaped in the subpial area. Astrocyte processes were fine, and evenly distributed in a predominantly radial pattern in transverse sections of cord. Gliosis was marked in the spinal cords of horses with cervical compressive myelopathy. In the grey matter at the level of compression astrocytes were often enlarged and rounded, with short, blunt processes, but the gliosis was generally mild. In the white matter, gliosis was obvious in areas of nerve fibre swelling and degeneration at the level of compression and in areas of ascending and descending Wallerian degeneration. The fine radial pattern of astrocyte fibres was replaced by a dense, irregular arrangement. Gliosis persisted in the cords of chronically affected horses after active nerve fibre degeneration had subsided. The areas of gliosis coincided with the areas of Marchi staining for degenerating myelin and with areas of myelin loss in osmium tetroxide post-fixed tissue. Histological observations were consistent with astrocytes replacing areas of extracellular space that remained after nerve fibre degeneration. it is concluded that astrocytic gliosis is a prominent and persistent alteration of the spinal cord of horses with chronic cervical compressive myelopathy.  相似文献