A Test of Positive Association for Detecting Heterogeneity in Capture for Capture–Recapture Data     

Anita Jeyam  Rachel S. McCrea  Thomas Bregnballe  Morten Frederiksen  Roger Pradel 《Journal of Agricultural, Biological & Environmental Statistics》2018,23(1):1-19

The Cormack–Jolly–Seber (CJS) model assumes that all marked animals have equal recapture probabilities at each sampling occasion, but heterogeneity in capture often occurs and should be taken into account to avoid biases in parameter estimates. Although diagnostic tests are generally used to detect trap-dependence or transience and assess the overall fit of the model, heterogeneity in capture is not routinely tested for. In order to detect and identify this phenomenon in a CJS framework, we propose a test of positive association between previous and future encounters using Goodman–Kruskal’s gamma. This test is based solely on the raw capture histories and makes no assumption on model structure. The development of the test is motivated by a dataset of Sandwich terns (Thalasseus sandvicensis), and we use the test to formally show that they exhibit heterogeneity in capture. We use simulation to assess the performance of the test in the detection of heterogeneity in capture, compared to existing and corrected diagnostic goodness-of-fit tests, Leslie’s test of equal catchability and Carothers’ extension of the Leslie test. The test of positive association is easy to use and produces good results, demonstrating high power to detect heterogeneity in capture. We recommend using this new test prior to model fitting as the outcome will guide the model-building process and help draw more accurate biological conclusions. Supplementary materials accompanying this paper appear online.  相似文献   

Mortality,fecundity and development among bed bugs (Cimex lectularius) exposed to prolonged,intermediate cold stress          下载免费PDF全文

Bjørn A Rukke  Morten Hage  Anders Aak 《Pest management science》2017,73(5):838-843

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Manual geo-rectification to improve the spatial accuracy of ortho-mosaics based on images from consumer-grade unmanned aerial vehicles (UAVs)     

Azim  Saiful  Rasmussen  Jesper  Nielsen  Jon  Gislum  René  Laursen  Morten Stigaard  Christensen  Svend 《Precision Agriculture》2019,20(6):1199-1210

Precision Agriculture - The global spatial accuracy of ortho-mosaics based on images from consumer-grade unmanned aerial vehicles (UAVs) is relatively low. The use of ground control points (GCPs)...  相似文献   

Evaluation of skin erythema by use of chromametry and image analysis of digital photographs after intradermal administration of histamine in dogs     

Boysen L  Sørensen P  Larsen M  Serup J  Kristensen F 《American journal of veterinary research》2002,63(4):565-569

OBJECTIVE: To investigate whether the degree of erythema during an induced erythematous reaction, the histamine skin test reaction, can be assessed objectively by use of chromametry and image analysis of digital photographs. ANIMALS: 9 pet dogs (6 Golden Retrievers and 3 yellow Labrador Retrievers). PROCEDURE: Histamine phosphate was injected intradermally, and erythema of the wheal reaction was evaluated during the hour that followed. This was done by use of clinical scores, chromametry, and image analysis of digital photographs. Method reproducibility was tested for visual evaluation of printouts of digital photographs and for image analysis of the same photographs. RESULTS: The coefficient of variation of the technically derived erythema values was < 10%. The reproducibility of image analysis was high and the range of agreement between observers narrow. Using chromametry, it was not possible to differentiate between various degrees of erythema intensity as visually perceived. In contrast, use of image analysis of digital photographs enabled discrimination of slight erythema from moderate and marked erythema. The dynamics of reaction measured by chromametry followed the clinical observation. CONCLUSIONS AND CLINICAL RELEVANCE: Chromametric values are comparable to those obtained by visual inspection. As the result of standardized conditions, chromametry is preferred over digital photography.  相似文献   

Characterization of avipoxviruses from wild birds in Norway   总被引：1，自引：0，他引：1       下载免费PDF全文

Simon Chioma Weli  Malachy Ifeanyi Okeke  Morten Tryland  ?ivind Nilssen    Terje Traavik 《Canadian journal of veterinary research》2004,68(2):140-145

Avipoxviruses from different geographic regions of the world have been characterized to study their genetic and biological properties, but so far, no such work has been performed on Norwegian isolates. Lesions suggestive of avian pox, found on a Norwegian wild sparrow (Passer domesticus) and wood pigeon (Palumbus palumbus), were obtained in 1972 and 1996, respectively. Histologically, these lesions were demonstrated to be characteristic of poxvirus infections and the poxvirus was observed using an electron microscope. The resulting viruses were propagated in chicken embryo fibroblast cells. Restriction fragment length polymorphism of genomes from 2 Norwegian isolates and fowl pox vaccine strain, generated by BamHI, revealed a high degree of heterogeneity among the isolates. The profiles of avipoxviruses isolated from wild birds were clearly distinct from each other and also to the fowl poxvirus strain. Furthermore, chickens experimentally infected with pigeon poxvirus had higher antibody titers and extensive lesions compared to other isolates. This may suggest that pigeon poxvirus is more virulent than the other isolates.  相似文献   

Porcine salmonellosis. II. Production of the generalized Shwartzman reaction by intravenous injections of disintegrated cells of salmonella cholerae-suis     

Knut Nordstoga  Morten Fjlstad 《Acta veterinaria Scandinavica》1970,11(3):370-379

Three pigs were given intravenous injections of disintegrated cells of Salmonella cholerae-suis. One of these pigs developed macroscopic bilateral renal cortical necrosis. Histologic examination revealed, besides total cortical parenchymal necrosis, also severe vascular injury, characterized with fibrinoid necrosis of the vessel walls and fibrin thrombi within their lumina. These findings were interpreted as a result of a generalized Shwartzman reaction, provoked by the action of bacterial endotoxin.  相似文献   

Regional differences in harvesting levels and wood-based employment in Norway     

Ståle Størdal  Kristian Lein  Morten Ørbeck  Svein Erik Hagen 《Small-Scale Forestry》2004,3(1):35-47

In this paper, a statistical framework based upon shift-share analysis is employed to analyse regional differences in Norway regarding changes in harvesting levels and number of full-time equivalent employees in wood processing. Changes in harvesting levels and employment differ between regions. A tendency found is that there has been a moderate centralisation in the period 1990–2000 with respect to harvesting levels. The analysis indicates that remote municipalities harvest relatively more in periods with a high harvesting intensity, while the harvesting level is more evenly distributed among the regions in other periods. There is, however, no clear picture whether there has been a centralisation or decentralisation regarding woodbased employment. Differences between regions may therefore be explained by structural factors, for example the degree to which firms in a particular region concentrate on production of bulky commodities or more customeroriented niche production.  相似文献   

Prevalence of Brucella pinnipediae in healthy hooded seals (Cystophora cristata) from the North Atlantic Ocean and ringed seals (Phoca hispida) from Svalbard     

Tryland M  Sørensen KK  Godfroid J 《Veterinary microbiology》2005,105(2):103-111

Investigations for Brucella-infections were conducted in 29 hooded seals (Cystophora cristata) caught between Svalbard and Greenland (North Atlantic Ocean; Greenland Sea) autumn 2002, and from 20 ringed seals (Phoca hispida) caught in Billefjord, Svalbard, spring 2003. All animals were apparently healthy and were caught in their natural habitat. Bacteriology on tissue samples from ringed seals was negative, whereas Brucella sp. were recovered in tissues from 11 of the 29 hooded seals (38%), with the highest tissue prevalence in spleen (9/29) and lung lymph nodes (9/24). Anti-Brucella antibodies were detected in sera from 9 hooded seals (31%) (EDTA-modified Slow Agglutination test of Wright, Rose Bengal test, Complement Fixation Test, and Protein-A ELISA). The bacterial isolates all belonged to the genus Brucella according to classical biotyping and PCR analysis based on Insertion Sequence IS711, and were shown to be typical marine mammal strains, based on the occurrence of an IS711 element downstream of the bp26 gene. Their dependency on CO2 for growth, and the presence of one copy each of the omp2a and omp2b gene finally classified them as Brucella pinnipediae. Furthermore, all the hooded seal isolates showed an A+ M+ agglutination profile, which is different from the profile of reference seal strain 2/94 (harbour seal, Phoca vitulina). Thus, these results indicate that B. pinnipediae may contain different biovars. The present results suggest that infection with B. pinnipediae is enzootic in this population. Since the hooded seal is commercially hunted and consumed in Norway, the pathological impact of such infections and their zoonotic potential should be further addressed.  相似文献   

Activity patterns of free-ranging beef cattle in Norway     

Morten Tofastrud  Hilde Hegnes  Olivier Devineau  Barbara Zimmermann 《Acta Agriculturae Scandinavica, Section A - Animal Sciences》2018,68(1):39-47

The aims of this study were to: 1) build a model to classify cattle activities based on locomotion and neck movement data and 2) study the daily time budget of non-native beef cattle in the boreal forest of southeastern Norway. We used GPS collars programmed to take positions and activity measures every five minutes on 18 cows during the grazing seasons 2015–17, together with behavioural observations in the field. The model classified the collar data into Grazing, Low (resting behaviours) and High (other active behaviours) activity with an accuracy of 79.4%. The cows spent 8.1?±?0.5 (mean?±?SD) hours per day grazing, corresponding to 34%?±?0.5% of their daily time budget. Daily grazing time increased during summer and was longer for lactating than dry cows and at low compared to high stocking density.  相似文献   

dl‐methionine enrichment in diets fed to Atlantic salmon increases apparent digestibility     

Marit Espe  Bjørn Liaset  Ernst Morten Hevrøy  Adel El‐Mowafi 《Aquaculture Research》2011,42(8):1123-1130

In the current study, we tested whether the addition of a small amount of crystalline dl ‐methionine to a fishmeal‐based diet would affect general sulphur metabolism and apparent digestibility in Atlantic salmon (Salmo salar). Triplicate tanks of salmon with mean BW of half a kilo were fed a control diet or the control diet supplemented with 0.2 wt%dl ‐methionine (+17% methionine relative to control diet) for a period of 3 months. Feed intake and thus nutrient intake did not differ significantly between treatments. Fish fed the diet supplemented with dl ‐methionine had 18% higher mean intake of methionine. The apparent energy digestibility was significantly improved in the salmon fed the methionine‐enriched diet as was the methionine digestibility. Salmon fed the methionine‐supplemented diet had about 32% higher plasma‐free methionine concentration and 25% more total homocysteine 5 h post prandial. No difference was observed in hepatic‐free methionine, but hepatic cystathionine (～62%) and taurine (～20%) were significantly higher in fish fed the methionine‐enriched diet due to a higher transsulphuration. In the liver, taurine might be conjugated to bile acids (BAs), and conjugation of BAs increases their solubility and enhances their biliary secretion affecting the digestibility. Both faecal and plasma BA concentrations were elevated in fish fed the methionine‐enriched diet, although the differences did not reach statistical significance. Taken together, our data show that feeding salmon a fishmeal‐based diet supplemented with a small amount of crystalline dl ‐methionine increased the apparent energy digestibility, possibly through an increased liver transsulphuration and taurine production, which might enhance BA conjugation and biliary secretion.  相似文献