Integrated Water Resources Management   总被引：1，自引：0，他引：1  

Per Stålnacke  Geoffrey D. Gooch 《Irrigation and Drainage Systems》2010,24(3-4):155-159

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Effect of pancreas disease caused by SAV 2 on protein and fat digestion in Atlantic salmon     

Magnus Vikan Rsg  Espen Rimstad  Arne Guttvik  Brd Skjelstad  Eldar sgard Bendiksen  se Helen Garseth 《Journal of fish diseases》2019,42(1):97-108

Salmonid alphavirus (SAV) causes pancreas disease (PD) in farmed Atlantic salmon (Salmo salar L.), and exocrine pancreas tissue is a primary target of the virus. Digestive enzymes secreted by the exocrine pancreas break down macromolecules in feed into smaller molecules that can be absorbed. The effect of SAV infection on digestion has been poorly studied. In this study, longitudinal observations of PD outbreaks caused by SAV subtype 2 (SAV2) in Atlantic salmon at two commercial sea sites were performed. The development of PD was assessed by measurement of SAV2 RNA load and evaluation of histopathological lesions typical of PD. Reduced digestion of both protein and fat co‐varied with the severity of PD lesions and viral load. Also, the study found that during a PD outbreak, the pen population comprise several subpopulations, with different likelihoods of being sampled. The body length of sampled fish deviated from the expected increase or steady state over time, and the infection status in sampled fish deviated from the expected course of infection in the population. Both conditions indicate that disease status of the individual fish influenced the likelihood of being sampled, which may cause sampling bias in population studies.  相似文献   

Time after seawater transfer influences immune cell abundance and responses to SAV3 infection in Atlantic salmon          下载免费PDF全文

J Jarungsriapisit  L J Moore  I U Fiksdal  H Bjørgen  A Tangerås  B Köllner  E O Koppang  S Patel 《Journal of fish diseases》2018,41(8):1269-1282

Pancreas disease (PD) caused by salmonid alphavirus (SAV) severely affects salmonid aquaculture during the seawater phase. To characterize immune cells in target tissues for SAV infection, heart, pancreas and pyloric caeca were analysed from two groups of fish adapted to seawater for 2 and 9 weeks. The sections were scored for the relative abundance of cells expressing MHC class II, IgM, CD3, CD8 or neutrophil/granulocyte markers using immuno‐histochemical techniques. In general, necrosis of tissue was more severe in fish infected at 2 weeks post‐seawater transfer (wpt) compared with those infected at 9 wpt. At 9 wpt, there were higher numbers of MHC II⁺ cells in heart, pancreas and pyloric caeca, IgM⁺ cells in heart and pancreas, and CD3⁺ cells in pancreas compared to those infected at 2 wpt. The majority of the immune cells infiltrating PD‐affected tissues were MHC II⁺ and CD3⁺ cells suggesting that antigen‐presenting cells and T lymphocytes are the main types of immune cells responding to SAV infection. All the investigated cell types were also observed in pyloric caeca of infected fish, suggesting that this tissue may play a role in the immune response to SAV.  相似文献   

Valuation of salmon farming companies     

Bård Misund 《Aquaculture Economics & Management (Blackwell Science)》2018,22(1):94-111

Financial statement information is important for evaluating a firm’s performance, and for forecasting its future cash flows. This paper studies the relationship between financial accounting information and market valuation for publicly listed salmon farming companies. Of special interest is the impact on market valuation, of a requirement for salmon farmers to disclose the effect on their financial numbers of the fair-value adjustment of biomass. The results suggest that the fair-value adjustment results in higher volatility of profits, and lower value relevance for investors.  相似文献   

Detection of live larvae in cocoons of Bathyplectes curculionis (Hymenoptera: Ichneumonidae) using visible/near‐infrared multispectral imaging          下载免费PDF全文

Santosh Shrestha  Henrik Bak Topbjerg  Nanna Karkov Ytting  Henrik Skovgård  Birte Boelt 《Pest management science》2018,74(9):2168-2175

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Phytotoxin produced by the netted scab pathogen, <Emphasis Type="Italic">Streptomyces turgidiscabies</Emphasis> strain 65, isolated in Sweden     

Masahiro Natsume  Asaho Nagagata  Marja Aittamaa  Naoko Okaniwa  Panu Somervuo  Hans-Peter Fiedler  Jan F. Kreuze  Veli-Matti Rokka  Hans Bång  Hiroshi Kawaide  Jari P. T. Valkonen 《Journal of General Plant Pathology》2018,84(2):108-117

Streptomyces spp. are a highly diverse group of bacteria most of which are soil-inhabiting saprophytes. A few are plant pathogens that produce a family of phytotoxins called thaxtomins and cause significant economic losses, e.g., by reducing the marketability of potato tubers (Solanum tuberosum). In northern Europe, S. scabies, S. turgidiscabies and S. europaeiscabiei are the most common plant pathogenic species. In this study, a Streptomyces strain isolated from a netted scab lesion on a tuber of potato cv. Bintje in northern Sweden was identified as S. turgidiscabies but was found to differ in the genomic region carrying genes required for thaxtomin biosynthesis. Our results showed that the strain did not produce thaxtomin but rather phytotoxin fridamycin E, which is an anthraquinone novel to plant pathogenic Streptomyces spp. Fridamycin E was shown to reduce or inhibit sprouting of potato microtubers in vitro. While fridamycin E is known to have antibiotic activity against Gram-positive bacteria, the inhibitory activity of fridamycin E on plant growth is a novel finding.  相似文献   

Genetic and phenotypic diversity within the Fusarium graminearum species complex in Norway     

Aamot  H. U.  Ward  T. J.  Brodal  G.  Vrålstad  T.  Larsen  G. B.  Klemsdal  S. S.  Elameen  A.  Uhlig  S.  Hofgaard  I. S. 《European journal of plant pathology / European Foundation for Plant Pathology》2015,142(3):501-519

European Journal of Plant Pathology - As has been observed in several European countries, the frequency of Fusarium head blight (FHB) caused by members of the Fusarium graminearum species complex...  相似文献   

Rotifers enriched with iodine,copper and manganese had no effect on larval cod (Gadus morhua) growth,mineral status or redox system gene mRNA levels          下载免费PDF全文

Sam Penglase  Kristin Hamre  Pål A Olsvik  Espen Grøtan  Andreas Nordgreen 《Aquaculture Research》2015,46(8):1793-1800

It currently remains unclear if rotifers contain sufficient mineral levels to meet larval fish requirements. In this study, rotifers were enriched with a commercial enrichment (control), or with additional iodine, iodine and copper, or iodine, copper and manganese, and the effects of feeding these rotifers to Atlantic cod (Gadus morhua) larvae from 3 to 18 days post hatch were investigated. Rotifer enrichment with minerals was successful, but Mn enrichment also increased rotifer zinc levels. No differences were observed between treatments in larval growth or survival, or in the mRNA levels in the majority of the redox system genes analysed. Only Zn levels increased in cod larvae in response to mineral enrichment of rotifers. Apart from Zn, little evidence was found to suggest that cod larvae require increased concentrations above the control rotifer levels of the essential elements studied here.  相似文献   

The “soil microbial loop” is not always needed to explain protozoan stimulation of plants     

Flemming Ekelund  Stephane Saj  Mette Vestergrd  Joanne Bertaux  Juha Mikola 《Soil biology & biochemistry》2009,41(11):2336-2342

Protozoa stimulate plant growth, but we do not completely understand the underlying mechanisms, and different hypotheses seek to explain this phenomenon. To test these hypotheses, we grew the grass Yorkshire fog (Holcus lanatus) in pots with soil, which contained either (1) no organisms but bacteria – or (2) bacteria and protozoa. Half of the pots received a glucose treatment so as to mimic an additional root exudation. We measured plant growth and plant nitrogen uptake, along with various microbial pools and processes that support plant growth. Protozoan presence significantly enhanced soil nitrogen mineralization, plant nitrogen uptake from organic nitrogen sources, plant nitrogen content, and plant growth. By contrast, we found no evidence that glucose addition, mimicking root exudation, increased soil nitrogen availability and plant nitrogen uptake. Moreover, although protozoan presence affected bacterial community structure, it did not affect the proportion of IAA-producing bacteria in the community or plant root morphology. These results refute the “soil microbial loop” hypotheses, which suggest that protozoan stimulation of plant growth results from complex interactions between plant roots, bacteria and protozoa. Our experiment thus favours the simple explanation that increased nitrogen availability is the key factor behind the positive protozoan effect on plant growth. To exploit natural resources in an efficient and environmentally friendly way, we need to understand in detail the functioning of ecosystems. This study stresses that to achieve this, it is still urgent, besides investigating intricate food-web and signal compound interactions, also to focus on the basic stoichiometric and energetic aspects of organisms.  相似文献   

Non-iterative variance component estimation in QTL analysis     

L. Rönnegård  R. Al-Sarraj  & D. von Rosen 《Zeitschrift für Tierzüchtung und Züchtungsbiologie》2009,126(2):110-116

In variance component quantitative trait loci (QTL) analysis, a mixed model is used to detect the most likely chromosome position of a QTL. The putative QTL is included as a random effect and a method is needed to estimate the QTL variance. The standard estimation method used is an iterative method based on the restricted maximum likelihood (REML). In this paper, we present a novel non-iterative variance component estimation method. This method is based on Henderson's method 3, but relaxes the condition of unbiasedness. Two similar estimators were compared, which were developed from two different partitions of the sum of squares in Henderson's method 3. The approach was compared with REML on data from a European wild boar × domestic pig intercross. A meat quality trait was studied on chromosome 6 where a functional gene was known to be located. Both partitions resulted in estimated QTL variances close to the REML estimates. From the non-iterative estimates, we could also compute good approximations of the likelihood ratio curve on the studied chromosome.  相似文献