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991.
The fecundity and oocyte diameter of 70 female capelin (Mallotus villosus) from the Barents Sea were investigated. The average fecundity (±SE) was 11 542 (±261). Oocyte diameter and fecundity increased with increasing weight and length of the capelin. Interannual variation in capelin fecundity is large, and corresponds to differences in body weight as revealed by a comparison with previous studies. Received: 10 May 1997 / Accepted: 1 August 1997  相似文献   
992.
The authors present a global overview on the issue of drugs and driving covering four major areas: (1) Epidemiology and Prevalence--which reviews epidemiological research, summarizes available information, discusses the methodological shortcomings of extant studies, and makes recommendations for future research to better define prevalence and epidemiology; (2) Effects of Medicinal and Illegal Drugs on Driving Performance--focuses on the six classes of drugs most often found in impaired and injured drivers, draws conclusions regarding the risk of these drugs to traffic safety and discusses the need for additional research; (3) Toxicological Issues--discusses ways to identify drug users via behavioral testing and analytical techniques, reviews the approaches used by different countries, screening and confirmation techniques, alternative specimens (e.g., urine, oral fluid, sweat), and how rapid roadside testing could be coupled with behavioral and laboratory testing in an effective approach to identifying and prosecuting drugged drivers; (4) Driving Under the Influence of Drugs [DUID] Laws--provides an overview of DUID laws in the United States and Europe, discusses the basic tenets of these laws, the various types of DUID statutes, the reasons why many existing laws hinder the prosecution of drugged drivers and the rationale for developing per se legislation as a strategy to more effectively manage the drugged driver problem.  相似文献   
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Knowledge and documentation of the levels of radioactive contamination in fish stocks important to Norwegian fisheries is of major importance to Norwegian consumers and fish export industry. In the present study, the bioaccumulation of caesium-137 ((137)Cs) has been investigated in marine food webs in the Barents and Norwegian Seas. The contents of (137)Cs in the different organisms were generally low (<1 Bq kg(-1) wet weight), but a marked bioaccumulation was apparent: The concentration of (137)Cs was about 10-fold higher in the harbour porpoise Phocoena phocoena, representing the upper level of the food web, than in the amphipod Themisto sp., representing the lower level of the food web. The Concentration Factors (CF=Bq kg(-1) wet weight/Bq l(-1) seawater) increased from 10+/-3 for a mixed sample of krill and amphipods to 165+/-5 for harbour porpoises.  相似文献   
995.
The distribution of moisture, degradable C, and N after direct injection of slurry can affect the turnover and plant availability of slurry N. This study examined effects of injection method, soil conditions, and slurry properties on the infiltration of several slurry components under practical conditions. The water retention capacity of 22 pig and cattle slurries was quantified by dialysis at -0.016, -0.047, and -0.100 MPa. All slurries followed the relationship: relative water loss = 1/(1 + aVS[volatile solids]), indicating that retention of liquids in the slurry injection zone can be predicted from slurry VS and soil water potential. Two-disc injection and harrow tine injection were simulated (no slurry applied) in five trials. Two trials indicated that disc injection resulted in higher permeability compared with harrow tine injection. In a separate experiment, soil moisture and dissolved ions were monitored in and around injection slits amended with pig or cattle slurry. Moisture gradients, which were recorded with small printed-circuit-board (PCB) time-domain-reflectometry (TDR) probes, were temporally stable and reestablished following rainfall. Slit sections with pig and cattle slurry containing 13C-acetate and 15N-ammonium showed a shift in the 13C to 15N ratio of the injection zone within 24 h, which was explained by removal of dissolved C and/or retention of NH4+. Cattle slurry was more concentrated around the injection slit than pig slurry, and greater contact between slurry and soil was obtained with harrow tine injection. The heterogeneity of slurry C and N distribution after direct injection should be accounted for in models describing slurry N turnover.  相似文献   
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