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MAGNUS AUNE WIEDMANN OLE‐PETTER PEDERSEN EINAR MAGNUS NILSSEN 《Fisheries Oceanography》2012,21(6):379-392
Oceanographic and predation processes are important modulators of fish larvae survival and mortality. This study addresses the hypothesis that immature Norwegian spring‐spawning herring (Clupea harengus), when abundant in the Barents Sea, determine the capelin reproduction success through consumption of Barents Sea capelin (Mallotus villosus) larvae. Combining a hydrodynamic model and particle‐tracking individual‐based model, a realistic spatio‐temporal overlap between capelin larvae and predatory immature herring was modelled for the summer seasons of 2001–2003. Capelin larvae originating from western spawning grounds became widely dispersed during the summer season, whereas those originating from eastern spawning grounds experienced a rapid drift into the southeastern Barents Sea. Herring caused a 3% mortality of the capelin larvae population in 2001 and a 16% mortality in 2003, but the effect of predation from herring on capelin larvae was negligible in 2002. Despite a strong capelin larvae cohort and a virtual absence of predatory herring, the recruitment from the capelin 2002 year class was relatively poor from a long‐term perspective. We show that the choice of capelin spawning grounds has a major impact on the subsequent capelin larvae drift patterns, constituting an important modulator of the capelin larvae survival. Variation in drift patterns during the summer season is likely to expose the capelin larvae to a wide range of hazards, including predation from young cod, sandeel and other predators. Such alternative predators might thus have contributed to the poor capelin recruitment during 2001–2003, leading to the collapse of the capelin stock in the subsequent years. 相似文献
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PPP is a data program that facilitates the recording and handling of plant samples sent to a diagnostic laboratory. The program can be used to retrieve help information from earlier advisory work to produce written replies to the sender. The letters are written both to files and to printers. The program may be used as a single user program or as a network program applying an internal communication program. A decision support system designed to help in advisory work may be used together with the PPP or as a stand-alone module (CaSK Aid). 相似文献
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The infection efficiency and severity of leaf blotch on spring barley inoculated with three pathotypes of Rhynchosporium secalis from central Norway were studied under different temperature and humidity regimes. Seedlings of the cultivar Arve were subjected to two constant temperatures, 13° or 18°C. Dry periods of 8 h or longer before or after a wet period of 4 h, carried out in the first 48 h postinoculation, reduced disease severity assessed 16 days after inoculation. The effect of dry periods of up to 24 h was nullified when plants were subjected to high humidity for 48 h after the dry treatment. The disease developed most rapidly when the wet period was 48 h and the temperature 18°C. At or near the optimum temperature for R. secalis (18°C), leaf wetness duration as short as 2 h resulted in considerable disease. Isolates reacted differently to temperature. The most aggressive isolate caused severe disease irrespective of temperature (56–70% of the leaf area infected); however, disease severity caused by the least aggressive isolate was significantly higher at the optimum temperature compared with a lower temperature (13°C). This information can facilitate evaluation of weather data in relation to predicting leaf blotch for advisory purposes. 相似文献
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There may be a great potential in the use of diagnostic "markers" of osteoarthritis in synovial fluid to diagnose the disease in an earlier stage and perhaps assess the severity of the disease and monitor the effect of a treatment. In the present study, potential markers are characterized, discussed, and grouped according to the latest knowledge on the etiology, pathogenesis, and pathology of osteoarthritis. They are grouped according to their origin as either cartilage degradation products, or related to the mechanisms of cartilage degradation, or related to chron-drocytic anabolic activity during disease, or related to genetic disorders. Also potential markers that have not yet been studied clinically or experimentally are discussed. Examples of the progress that has been made in human medicine approaching reliable diagnostic markers that should also be tried in veterinary medicine are described. 相似文献
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BERNDT STROMBERG STEN–ERIK OLSSON MAGNUS LUNDGREN 《The Journal of small animal practice》1978,19(1-12):689-696
Radiation dose to personnel and low capacity X–ray equipment are obstacles to the optimal use of veterinary radiology. In order to find means to lower radiation dose and improve the quality of the radiographic image in veterinary radiology the authors have tested the so–called rare earth intensifying screens under experimental and clinical conditions. Of the basis of their findings they recommend the use of predominantly green light–emitting screen with lanthanum oxysulphide crystals activated with terbium, in combination with orthochromatic film. This combination was shown to give the best ratio image–screen noise. Considerable dose reduction was obtained with this system, and the image quality improved due to less blurring by motion. 相似文献
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As part of a national project set up in 1988 to incorporate all pest warning activities in Norway into one information system, NORPRE provides warnings for cereal growers. The system is based on growers' observations and on meteorological data. It can be accessed by an audiotex system TELEWISE, which also provides weather reports and forecasts. 相似文献
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Data collected at weather stations are usually used to represent the environmental conditions over the surrounding area (often in the order of 10s or 100s of km2), in spite of differences in elevation, terrain, and other major geophysical factors. We report a method of extending the useful domain of weather data by incorporation of digital terrain data into a model that distributes recorded data over the area surrounding a recording location. Temperature was estimated for each 0.1 km2 witnin a 320 km2 study area comprising Vestfold county in southern Norway. Estimates were based on correlation analysis and models resulting from comparisons of temperature data from 16 farm locations and temperature recorded at three automatic weather stations, elevation, slope, aspect, proximity to the ocean, and proximity to automatic weather stations. Analysis revealed that local weather could be estimated with greater accuracy than by simply using the values recorded at the automatic stations. Calculation and presentation of the model output can be accomplished with a geographic information system (GIS). 相似文献
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