Combined effects of temperature and salinity on development and survival of Atlantic halibut larvae     

Oddvar H. Ottesen  Sylvie Bolla 《Aquaculture International》1998,6(2):103-120

The effects of different combinations of temperature and salinity on development and survival of Atlantic halibut, Hippoglossus hippoglossus (L.), larvae were studied in two experiments. In the period from 57 to 120 d° post hatching, approximately 38% of the larvae died: in both experiments, mortality was significantly related to temperature, but there was no relationship to salinity.Cumulative, chronic mortality during the yolk-sac stage (until 210 d°) was related to salinity. High mortality was observed in both experiments when high salinity (>34%) was combined with incubation at either high (9 °C) or low (3 °C) temperature. The development of head lesions was significantly related to temperature, and for larvae kept at high salinity, increased mortality may have been a result of salinity stress in the injured larvae.Abnormal development of the caudal notochord, sometimes resulting in a 90-degree bend of the tail, occurred during incubation of early yolk-sac larvae in high-salinity water. The occurrence of larvae with locked jaws, and larvae with oedema in the yolk-sac sinus and pericardium, was significantly related to temperature. © Rapid Science Ltd. 1998  相似文献   

Elemental and Base Anions Deposition in the Snow Cover of North-Eastern Estonia     

Kaasik  Marko  Rõõm  Rein  Røyset  Oddvar  Vadset  Marit  Sõukand  Ülis  Tõugu  Kaire  Kaasik  Helle 《Water, air, and soil pollution》2000,121(1-4):349-366

Snow samples from 18 sites in Estonia were collected in February and March 1996 after 72–110 days of permanent snow cover. Three snow layers corresponding to different snow accumulation periods were separated in each sampling site. Snow water samples were analysed for sulphate (SO₄ ^2-), nitrate (NO₃ ^-), and chloride (Cl^-) ions and elemental composition. Deposition fluxes of 27 chemical species were used for factor, cluster and correlation analysis. The effects of cement dust, oil shale fly ash, sulphur dioxide and chlorine from emissions of thermal power plants were distinguished. A large number of trace metals are strongly correlated with each other (R > 0.8) and with macro-components (except NO₃ ^-), which refers to a common origin, identified as the mineral part of oil shale. Deposition fluxes of Ca, Mg, SO₄ ^2- and a number of mineral components exceed near the power plants 1–2 decimal orders the background value. The deposition fluxes in forested sites are up to 2 times higher than in open land sites. This difference may be caused by more efficient turbulent transfer over rougher surface. It is suggested, that NO₃ ^- and Zn originate mainly and Pb, Cd and Cu partially from non-local or diffuse sources (traffic, domestic heating, far transport). The results of this research could be used to evaluate the air pollution deposition models and for ecological impact estimations.  相似文献   

Mesenteric lymphography and ligation of the thoracic duct in a cat with chylothorax     

T W Fossum  S J Birchard  P A Arnold 《Journal of the American Veterinary Medical Association》1985,187(10):1036-1037

Mesenteric lymphography was used to identify and ligate the thoracic duct in a 1-year-old Himalayan cat with chylothorax. Lymphography revealed the thoracic duct to be intact; however, multiple dilated lymphatics, indicative of lymphangiectasia were evident in the cranial portion of the thorax. Hemostatic clips were used to ligate the thoracic duct. The effusion stopped, and 9 months after surgery, effusion has not recurred.  相似文献   

Irradiation of chicken egg white. I. Effect on proteinase inhibitors     

K Fossum  B Underdal 《Acta veterinaria Scandinavica》1973,14(1):118-128

Commercial ovomucoid trypsin inhibitors (OMTI) and egg white were exposed to various doses of gamma irradiation, using a cobalt-60 source. The inhibitory activity of non-irradiated and irradiated samples on bovine trypsin was tested by the Kunitz method (Kunitz 1947). The activity of the inhibitors was shown to decrease exponentially with increasing radiation dose. The D₁₀ for OMTI was 0.6 Mrad and for the trypsin inhibitors in the crude egg white diluted 1: 5 in saline 3.0 Mrad under the conditions used. The activity of the non-irradiated and irradiated inhibitors upon various animal, microbial and plant proteinases was also determined by using the crosswise casein precipitating inhibition test (crosswise CPI-test) (Fossum 1970a). By this method, which is more sensitive than the Kunitz method, trypsin inhibitory activity in egg white could be detected after exposure to an irradiation dose of 9 Mrad. No inhibitory activity could be found against any enzyme after an irradiation dose of 15 Mrad.Irradiation as a preservation method for egg and egg products is discussed.  相似文献   

Lymphangiographic evaluation of experimentally induced chylothorax after ligation of the cranial vena cava in dogs   总被引：2，自引：0，他引：2  

T W Fossum  S J Birchard 《American journal of veterinary research》1986,47(4):967-971

Ligation of the cranial vena cava (CrVC) distal to the entrance of the azygous vein resulted in chylothorax in 7 of 10 dogs. Of the remaining 3 dogs, 1 developed a serosanguineous effusion that did not become chylous, and 2 dogs did not develop pleural effusion. In 2 of the 7 dogs developing chylothorax, the pleural effusion became serosanguineous within 2.5 weeks after CrVC ligation. Mesenteric lymphangiography was performed 2 to 6 weeks after ligation of the CrVC. Lymphangiectasia was seen in 4 dogs with chylothorax, but was not seen in the 3 dogs with serosanguineous effusions or the 2 dogs that did not develop effusions. One dog with chylothorax died prior to repeat lymphangiography. Less dye entered the thoracic duct, and alternate lymphaticovenous communications to the caudal vena cava were evident in the dogs without chylothorax. Ligation of the thoracic duct at the lymphaticovenous junction was performed in 3 dogs. These dogs did not develop pleural effusion. Lymphangiography was performed immediately after ligation and indicated filling of abdominal lymphatics but not of the thoracic duct. Lymphangiographic findings 6 weeks after ligation also indicated filling of intestinal lymphatics. Results of the present study indicated that ligation of the CrVC causes chylothorax, and that thoracic lymphangiectasia is a consistent finding in animals with experimental chylothorax. Obstruction of the thoracic duct did not induce lymphangiectasia or chylothorax. Impedence of thoracic duct flow into the CrVC may be a cause of clinical chylothorax in the dog.  相似文献   

Gastrointestinal parasites in young cattle in Norway     

Oddvar Helle  Jorun Tharaldsen 《Veterinary parasitology》1976,1(4):345-357

Field experiments were carried out for three consecutive years to study the influence of gastrointestinal nematodes in young cattle during their first grazing season. Free-living stages of Ostertagia ostertagi and Cooperia oncophora were found to survive the winter in the pasture in sufficient numbers to cause reduced weight gain and clinical disease, including deaths, in the calves. The symptoms were most pronounced during the first half of the grazing season.The mean weight gain of calves on parasite-free pastures was 48.3, 15.5 and 31.2 kg above those on contaminated pastures during the 3 years.Calves grazing contaminated pasture from the spring onwards, treated with thiabendazole and moved to aftermath in July, showed significantly better weight gain during the last part of the grazing season than calves which remained on the same contaminated pasture. It was, however, suggested that the better grazing conditions were the main cause of the improved weight gain on aftermath.  相似文献   

Protein-losing enteropathy     

T W Fossum 《Seminars in veterinary medicine and surgery (small animal)》1989,4(3):219-225

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Evaluation of the prophylactic potential of an immunomodulator against respiratory disease in calves     

B. Larsson  C. Fossum  M. Trnquist  P. Matsson  S. Alenius 《Acta veterinaria Scandinavica》1985,26(2):262-272

The prophylatic effect against respiratory disease in feedlot calves of an immunomodulator, based on an inactivated avipox virus preparation, was evaluated in a double blind, placebo controlled field trial. The effect of the immunomodulator on phagocytosis and on the reactivity of the lymphocytes was also tested.On the day of arrival at the feedlots and 3 days later 257 calves were injected with either the immunomodulator or with placebo. All calves were then observed for respiratory disease and treatments were recorded. The immunomodulator did not reduce the frequency of disease, compared to the placebo. Thirty percent of the calves treated with the immunomodulator and 27 % of the controls were treated with antibiotics for respiratory disease.The cell mediated immune reactivity of 7 calves treated with the immunomodulator and of 7 untreated calves was tested. Monocytes isolated from the animals were examined for their ability to ingest latex beads and lymphocytes from the animals were examined for their response to different mitogens. Sera from each of the two groups were also investigated for the effect on phagocytosis. No difference in these parameters was observed between the two groups.  相似文献   

Scale-dependent importance of environment, land use and landscape structure for species richness and composition of SE Norwegian modern agricultural landscapes     

Rune H. Økland  Harald Bratli  Wenche E. Dramstad  Anette Edvardsen  Gunnar Engan  Wendy Fjellstad  Einar Heegaard  Oddvar Pedersen  Heidi Solstad 《Landscape Ecology》2006,21(7):969-987

Knowledge of variation in vascular plant species richness and species composition in modern agricultural landscapes is important for appropriate biodiversity management. From species lists for 2201 land-type patches in 16 1-km² plots five data sets differing in sampling-unit size from patch to plot were prepared. Variation in each data set was partitioned into seven sources: patch geometry, patch type, geographic location, plot affiliation, habitat diversity, ecological factors, and land-use intensity. Patch species richness was highly predictable (75% of variance explained) by patch area, within-patch heterogeneity and patch type. Plot species richness was, however, not predictable by any explanatory variable, most likely because all studied landscapes contained all main patch types – ploughed land, woodland, grassland and other open land – and hence had a large core of common species. Patch species composition was explained by variation along major environmental complex gradients but appeared nested to lower degrees in modern than in traditional agricultural landscapes because species-poor parts of the landscape do not contain well-defined subsets of the species pool of species-rich parts. Variation in species composition was scale dependent because the relative importance of specific complex gradients changed with increasing sampling-unit size, and because the amount of randomness in data sets decreased with increasing sampling-unit size. Our results indicate that broad landscape structural changes will have consequences for landscape-scale species richness that are hard or impossible to predict by simple surrogate variables.  相似文献   

Humoral immune responses to Mycoplasma hyopneumoniae in sows and offspring following an outbreak of mycoplasmosis     

Per Wallgren  Gran Blske  Stig Gustafsson  Sigbrit Mattsson  Caroline Fossum 《Veterinary microbiology》1998,60(2-4):193-205

Previously healthy sows, seropositive to Mycoplasma hyopneumoniae, developed clinical signs of mycoplasmosis, as well as increasing amounts of antibodies to M. hyopneumoniae during an outbreak of the disease in a herd. During the early phase of the outbreak, young piglets (2 weeks) with maternal antibodies remained healthy while older seronegative piglets (4–7 weeks) developed the disease. The duration of the maternal antibodies to M. hyopneumoniae varied between litters and was related to the amount of antibodies in the serum of the dam. In sows, the level of serum antibodies decreased continuously from 4 weeks ante partum to partus, and the level of antibodies in the whey of colostrum was comparable to that in serum 4 weeks ante partum. After loss of maternal antibodies to M. hyopneumoniae, seropositive animals were not found among piglets younger than 9 weeks. Therefore peripheral blood mononuclear cells (PBMC) were collected from various age categories of piglets in order to measure the ability to produce antibodies to M. hyopneumoniae in vitro. PBMC obtained from piglets aged 1 and 3 weeks produced few antibodies to M. hyopneumoniae. Significantly higher levels of antibodies to M. hyopneumoniae were produced by PBMC obtained from pigs aged 5–9 weeks. Thus, the ability of PBMC to produce antibodies to M. hyopneumoniae in vitro seemed to be age-dependent.  相似文献