Seal distemper in Norway in 1988 and 1989     

J Krogsrud  O Evensen  G Holt  S H?ie  N H Markussen 《The Veterinary record》1990,126(18):460-461

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Growth of four tree species managed as hedgerows in response to liming on an acid soil in West Sumatra,Indonesia     

C. I. Evensen  T. S. Dierolf  R. S. Yost 《Agroforestry Systems》1994,27(3):207-222

A hedgerow intercropping study was conducted for 7 years in West Sumatra, Indonesia on an acid and highly Al-saturated soil to determine growth and yield responses of tree hedgerows and upland rice and cowpea intercrops. Three tree species,Paraserianthes falcataria, Calliandra calothyrsus, andGliricidia sepium and a no-tree control were planted at three lime rates with low annual fertilizer inputs of 20 kg P and 50 kg K ha^–1.Paraserianthes andCalliandra grew vigorously, whileGliricidia grew poorly and was replaced after four years withFlemingia macrophylla. After four years,Paraserianthes yields declined due to tree mortality, probably due to intensive pruning.Calliandra andFlemingia were well adapted to intensive pruning (4 to 6 times per year). Gliricidia growth was especially limited by low soil Ca availability and high soil acid saturation.Calliandra andFlemingia yields increased with liming only in the last several years of the study whileParaserianthes did not respond to lime. The species can be tentatively ranked in response to lime as:Gliricidia > Calliandra > Flemingia > Paraserianthes.  相似文献   

A sequential light microscopic study of the pulmonary lesions in porcine dermatosis vegetans     

O Evensen  B Bratberg 《Research in veterinary science》1990,49(1):50-55

The sequential pulmonary changes in dermatosis vegetans were studied in pigs aged one, seven, 14, 17, 21 and 28 days, and two and a half, four and 12 months. At one day old the lung tissues appeared normal. At seven days old there was a moderate infiltration of mononuclear inflammatory cells in the alveolar structures, and proliferation of type II pneumocytes was also observed. At 14 and 17 days old the alveolar structures were intensely infiltrated with mononuclear inflammatory cells. At 21 days old, loosely arranged epithelioid and multinucleate giant cell granulomas appeared, and there was a proliferation of alveolar epithelial cells. By four and 12 months old the inflammatory changes diminished, and small granulomas and moderate alveolar fibrosis were present. The initial lesions were characterised by an alveolitis, developing into loosely arranged granulomas by four months old, and persisting to the age of 12 months. These observations suggest that the interpretation of the lung changes and the disease in general should be revised.  相似文献   

Pulmonary multinucleate giant cells in dermatosis vegetans in swine: light microscopic and immunohistochemical investigations     

O Evensen  B Bratberg 《Acta veterinaria Scandinavica》1987,28(3-4):429-433

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Mycobacterium avium subsp. paratuberculosis enters the small intestinal mucosa of goat kids in areas with and without Peyer's patches as demonstrated with the everted sleeve method     

Sigurdardóttir OG  Bakke-McKellep AM  Djønne B  Evensen O 《Comparative immunology, microbiology and infectious diseases》2005,28(3):223-230

The main lesions of paratuberculosis in ruminants are in the small intestine. Previous studies have shown that the bacterium enters the small intestine through M cells found in the follicle-associated epithelium lining the domes of the Peyer's patches. The everted sleeve method, devised for the in vitro study of intestinal absorption, was used in this study to investigate the uptake of Mycobacterium avium subsp. paratuberculosis in goat intestine. Everted small intestinal sleeves of goat kids, prepared from areas with and without Peyer's patches, were incubated for 60 min in 3H-labeled bacterial solution. The results of this study imply that the bacteria can enter the intestinal mucosa of the jejunum, both in areas with and without Peyer's patches. These findings indicate, therefore, that M. avium subsp. paratuberculosis bacteria not only enter through M cells but also through enterocytes.  相似文献   

Holding wild Snow crab,Chionoecetes opilio: effects of stocking density and feeding on survival and injury          下载免费PDF全文

Sten Ivar Siikavuopio  Philip James  Bjørn Ronald Olsen  Tor Evensen  Atle Mortensen  Stein Harris Olsen 《Aquaculture Research》2017,48(4):1590-1595

In this study the effects of different stocking densities on survival, injury and weight of captive male snow crab were examined. The first experiment (I) was carried out in square plastic tanks (700 L) with stocking densities of 100 (L), 150 (M) and 200 kg m^?3 (H) for 30 days. In a second experiment (II) snow crabs were kept at a stocking density of 50 kg m^?3 and were either fed (F) or not fed (S) for the same period of 35 days. The last experiment (III), was carried out with stocking densities of 25 kg m^?3 for 21 days with two groups, one with inactivated claw and one without rubber bands, with three replicates per treatment. In the first experiment mortality (H = 27, M = 26 and L = 36%) and occurrence of injuries (H = 27, M = 20 and L = 16%) were high in all groups. The weight loss during the experimental period was; H = 15.3, M = 10.9 and L = 15.5 g, and was not significant different between the groups. In experiment II the mortality (F = 13% and S = 14%) and injuries were lower (F = 12% and S = 17%). The average weight increased in the fed treatment and decreased in the starved treatments. In the last experiment there was no mortality in any of the groups and the levels of injury were low (5% and 7%). The results show that adult male snow crab cannot be stored at densities equal to or higher than 25 kg m^?3 for 3 weeks without risk of mortality.  相似文献   

Effects of Feral Pig (Sus scrofa) Exclusion on Enterococci in Runoff from the Forested Headwaters of a Hawaiian Watershed     

Dunkell  Dashiell O.  Bruland  Gregory L.  Evensen  Carl I.  Walker  Mark J. 《Water, air, and soil pollution》2011,220(1-4):313-326

Water, Air, &; Soil Pollution - The role feral pigs (Sus scrofa) as a source of fecal contamination in Pacific Island ecosystems is not well understood. This study investigated the effects of...  相似文献   

A decision making scheme for potato quality     

Joseph M. Russo  Kathleen B. Evensen  Harriet L. Braun 《American Journal of Potato Research》1988,65(6):341-351

A decision making scheme is proposed for integrating and evaluating variables important for judging tuber quality in the potato industry. Within the scheme, variables affecting potato quality are grouped into categories according to their mutual association in a decision, and their values are rated according to a common linear scale. Expert opinions, as to which range of variable values ensure “commercially acceptable” and “ideal” potato quality, were superimposed as shaded areas over the numerical ratings. Observations of variables used in a decision can be compared to values delineated by experts to judge whether sampled potatoes would be acceptable for commercial use. The scheme is designed to be utilized at various points in the life cycle of a potato from field to market. It is demonstrated for one variety of sampled tubers that were being stored for chip processing.  相似文献   

Immunohistochemical detection of piscine reovirus (PRV) in hearts of Atlantic salmon coincide with the course of heart and skeletal muscle inflammation (HSMI)     

Finstad OW  Falk K  Løvoll M  Evensen O  Rimstad E 《Veterinary research》2012,43(1):27

ABSTRACT: Aquaculture is the fastest growing food production sector in the world. However, the increased production has been accompanied by the emergence of infectious diseases. Heart and skeletal muscle inflammation (HSMI) is one example of an emerging disease in farmed Atlantic salmon (Salmo salar L). Since the first recognition as a disease entity in 1999 it has become a widespread and economically important disease in Norway. The disease was recently found to be associated with infection with a novel reovirus, piscine reovirus (PRV). The load of PRV, examined by RT-qPCR, correlated with severity of HSMI in naturally and experimentally infected salmon. The disease is characterized by epi-, endo- and myocarditis, myocardial necrosis, myositis and necrosis of the red skeletal muscle. The aim of this study was to investigate the presence of PRV antigens in heart tissue of Atlantic salmon and monitor the virus distribution in the heart during the disease development. This included target cell specificity, viral load and tissue location during an HSMI outbreak. Rabbit polyclonal antisera were raised against putative PRV capsid proteins μ1C and σ1 and used in immunohistochemical analysis of archived salmon heart tissue from an experimental infection. The results are consistent with the histopathological changes of HSMI and showed a sequential staining pattern with PRV antigens initially present in leukocyte-like cells and subsequently in cardiomyocytes in the heart ventricle. Our results confirm the association between PRV and HSMI, and strengthen the hypothesis of PRV being the causative agent of HSMI. Immunohistochemical detection of PRV antigens will be beneficial for the understanding of the pathogenesis of HSMI as well as for diagnostic purposes.  相似文献   

Sequential pathology after experimental infection with marine viral hemorrhagic septicemia virus isolates of low and high virulence in turbot (Scophthalmus maximus L)     

Brudeseth BE  Raynard RS  King JA  Evensen O 《Veterinary pathology》2005,42(1):9-18

Three marine viral hemorrhagic septicemia virus isolates were used to bath challenge turbot with the purpose of studying mortality and the pathology and antigen distribution over time. Two high-virulence isolates, 860/94, 4p168 and a low-virulence isolate 1p3 from a Baltic Sea herring were used. Organ samples were collected sequentially at 2, 4, 7, 10, 15, 20, 25, and 45 days postinfection. Specimens were processed for virology, histopathology, and immunohistochemistry. Organs during the early stages of infection (from 2 to 7 days) had virus isolation from all three groups only on day 7. Virus titer in kidney and heart sampled at day 25 was higher for the two virulent isolates compared with the low-virulence isolate. The viral distribution in situ of the two more virulent isolates from turbot (860/94) and herring (4p168) resembled viral hemorrhagic septicemia in rainbow trout with regard to the target organs. Early infection of endothelial cells in both kidney and heart was observed. Accumulated mean mortality was 41.5% for the turbot isolate 860/94, 48% for the herring isolate 4p168, and 3.5% for the herring isolate 1p3. This study revealed that the isolates from turbot (860/94) and herring (4p168) induced significantly higher mortality compared with the virus-free control and the herring isolate (1p3). The onset of mortality is markedly later in turbot compared with what is seen in rainbow trout.  相似文献