Hydrology influences breeding time in the white-throated dipper     

Nilsson  Anna L. K.  Skaugen  Thomas  Reitan  Trond  L’Abée-Lund  Jan Henning  Gamelon  Marlène  Jerstad  Kurt  Røstad  Ole Wiggo  Slagsvold  Tore  Stenseth  Nils C.  Vøllestad  L. Asbjørn  Walseng  Bjørn 《BMC ecology》2020,20(1):1-12

While nitrogen and carbon stable isotope values can reflect ecological segregation, prey choice and spatial distribution in seabirds, the interpretation of bulk stable isotope values is frequently hampered by a lack of isotopic baseline data. In this study, we used compound-specific isotope analyses of amino acids (CSIA-AA) to overcome this constraint and to study interspecific differences, seasonal and historical changes in trophic positions of five seabird species, three penguins and two petrels, from a sub-Antarctic seabird community. CSIA-AA allowed comparing trophic positions of seabirds with temperate and polar distributions. Gentoo and Magellanic penguins had the highest trophic positions during the breeding season (3.7 and 3.9), but decreased these (2.9 and 3.3) during the feed-up for moult. Intra-specific differences were also detected in Thin-billed prions, where carbon isotope values clearly separated individuals with polar and temperate distributions, both in the breeding and interbreeding periods. Thin-billed prions that foraged in polar waters had lower trophic positions (3.2) than conspecifics foraging in temperate waters (3.8). We further investigated historical changes by comparing museum samples with samples collected recently. Our pilot study suggests that Rockhopper penguins, Magellanic penguins and Thin-billed prions with temperate non-breeding distributions had retained their trophic levels over a 90–100 year period, while Gentoo penguins and Thin-billed prions with polar non-breeding distributions had decreased trophic levels compared to historical samples. In contrast, Wilson’s storm-petrels had slightly increased trophic levels compared to samples taken in 1924–1930. We applied compound-specific stable isotope analyses across a range of contexts, from intra-specific comparisons between stages of the breeding cycle to inter-specific seabird community analysis that would not have been possible using bulk stable isotope analyses alone due to differences in isotopic baselines.  相似文献   

Seroprevalence of and agroecological risk factors for Mycobacterium avium subspecies paratuberculosis and neospora caninum infection among adult beef cattle in cow-calf herds in Alberta, Canada     

Scott HM  Sorensen O  Wu JT  Chow EY  Manninen K 《The Canadian veterinary journal. La revue veterinaire canadienne》2007,48(4):397-406

A province-wide cross-sectional seroprevalence and agroecological risk factor study of Mycobacterium avium subspecies paratuberculosis (MAP) and Neospora caninum (NC) infection among cattle in 100 cow-calf herds in Alberta was conducted. The seroprevalence of MAP in adult cattle was 1.5% across all herds. Using a widely accepted herd test cutpoint of 2 or more seropositive cows out of 30 animals tested, 7.9% of herds were estimated to be infected (95% confidence interval (CI): 2.3-23.4%). Seroprevalence of MAP differed by agroecological region; specifically, cattle and herds in areas with high soil pH (> 7.0), southern latitudes, and arid climates had a moderately reduced risk of infection (P < 0.10). Seroprevalence of NC infection was 9.7% among adult beef cattle province-wide--these levels also varied by agroecological region--with 91.0% of herds infected overall.  相似文献   

Will the veterinary profession flourish in the future?     

Nielsen NO 《Journal of veterinary medical education》2003,30(4):301-307

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Vegetational changes in the Galápagos Islands during the period 1966–1973     

Ole Hamann 《Biological conservation》1975,7(1):37-59

Analysis of 12 permanent sample plots established in the Galápagos showed that introduced mammals have had a destructive influence on the vegetation; closed forest and scrub have been changed into open vegetation. The plots provide information on the regeneration ability of various types of vegetation. Scalesia forest, dominated by the endemic Scalesia pedunculata Hook. f., might under certain circumstances regenerate rapidly. Miconia scrub, dominated by the endemic Miconia robinsoniana Cogn., regenerates slowly and is consequently more vulnerable to the activities of man and introduced mammals. Arid zone vegetation, characterised especially by endemic species of Opuntia, is able to regenerate, but it is still too early to estimate how the regeneration will proceed. The suggested conservation measures include a continuation of the programme for elimination or control of introduced mammals, and a stronger control with the National Park areas on inhabited islands. Financial support is needed for the Galápagos National Park Service and the Charles Darwin Research Station to continue and enlarge the activities necessary to preserve the unique wildlife of the Galápagos Islands.  相似文献   

Economic utility of 3D remote sensing data for estimation of site index in Nordic commercial forest inventories: a comparison of airborne laser scanning,digital aerial photogrammetry and conventional practices     

Lennart Noordermeer  Terje Gobakken  Erik Næsset  Ole Martin Bollandsås 《Scandinavian Journal of Forest Research》2021,36(1):55-67

ABSTRACT

Forest productivity is a crucial variable in forest planning, usually expressed as site index (SI). In Nordic commercial forest inventories, SI is commonly estimated by a combination of aerial image interpretation, field assessment and information obtained from previous inventories. Airborne laser scanning (ALS) and digital aerial photogrammetry (DAP) data can alternatively be used for SI estimation, however the economic utilities of the inventory methods have not been compared. We compared seven methods of SI estimation in a cost-plus-loss analysis, by which we added the expected economic losses due to sub-optimal treatment decisions to the inventory costs. The methods comprised direct and indirect estimation from combinations of ALS, DAP and stand register data, and manual interpretation from aerial imagery supported by field assessment and information from previous inventories (conventional practices). The choice of method had great impact on both the accuracy and the economic value of the produced estimates. Direct methods using bitemporal ALS and DAP data gave the best accuracy and the smallest total cost. DAP was a suitable and low-cost data source for SI estimation. Estimation from single-date ALS and DAP data and age obtained from the stand register provided practical alternatives when applied to even-aged stands.  相似文献   

Remembering Robert Hugh Dunlop: A Canadian giant in veterinary medicine     

N. Ole Nielsen 《The Canadian veterinary journal. La revue veterinaire canadienne》2015,56(5):516-518

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Behavior Observation During Conformation Evaluation at a Field Test for Danish Warmblood Horses and Associations with Rideability and Performance Traits     

Janne Rothmann  Ole F. Christensen  Eva Søndergaard  Jan Ladewig 《Journal of Equine Veterinary Science》2014

Reactivity in horses, defined as a state of high arousal, has an impact on the daily handling and welfare of horses and can have an impact on the risk of causing human injuries. Behavior tests have been developed to assess reactivity, but these tests are difficult to apply in practice. The objectives of this study were to investigate how reactivity measured in a practical situation associates with rideability and performance and to explore the association between the measured reactivity and reactivity assessed by the horse's owner. A total of 234 Danish Warmblood females, 3 years of age, were videotaped and scored for reactivity during the evaluation of their conformation, and a questionnaire was completed by the owners. Associations between reactivity and performance traits were investigated by computing partial correlations (Pearson, r_p). A low negative correlation was found between rideability and reactivity (r_p = −0.16, P = .02) and between reactivity and free jumping (r_p = −0.14, P = .03). These results suggest that highly reactive horses received lower grades in rideability and free jumping. However, no association with performance traits in dressage was found. Likewise, low but significant association was found between reactivity and ratings from owners (r_p = 0.15, P = .02), indicating that horses considered to be nervous by their owners also were scored as reactive. In conclusion, it appears possible to measure reactivity in a practical situation. This study also concluded low negative associations between reactivity and the two performance traits rideability and free jumping.  相似文献   

The effect of slaughtering procedures on blood spotting in rainbow trout (Oncorhynchus mykiss) and Atlantic salmon (Salmo salar)     

Bjorn Roth  Ole Johan Torrissen  Erik Slinde 《Aquaculture (Amsterdam, Netherlands)》2005,250(3-4):796-803

Rainbow trout (Oncorhynchus mykiss) and Atlantic salmon (Salmo salar) were submitted for various slaughter and bleeding procedures to see what effect this would have on blood drainage of the muscles. Results show that the bleeding method is of less importance, while it is the timing that is important. No significant difference in bloodspotting was observed between fish that were bled live by a gill cut or percussive killed and bled by gutting. Most of the drainage of blood in the fish muscle seems to occur within the first hours postmortem, so rigor mortis is of little importance. The visual appearance of the fillet was influenced by number and size of the bloodstains. Colour measurements with Hunter L*, a*, b* did not reveal this. We conclude that a gill cut is not necessarily to obtain bleeding, so the industry can omit this phase and go directly to gutting.  相似文献   

Treatment of the early life stages of scallop (Pecten maximus) with antimicrobial agents; searching for an alternative to chloramphenicol     

Lise Torkildsen  Rosie Coyne  Ole Bent Samuelsen  Thorolf Magnesen  Øivind Bergh 《Aquaculture International》2002,10(5):399-409

High mortality rates are often observed in rearing the early stages of the great scallop, Pecten maximus. The addition of antibacterial agents has been necessary to improve larval survival. However, as one antibacterial agent, chloramphenicol, is banned in Norway and Europe the aim of this study is to investigate alternative antibacterial agents. The therapeutic agents investigated in this study were florfenicol, oxytetracycline, oxolinic acid, neomycin and Pyceze. The mean minimum inhibitory concentration (MIC) values were determined for oxytetracycline, oxolinic acid and Pyceze against bacteria isolated from scallop larvae. Two types of treatment regime were investigated on an intermediate scale (20 L). One regime involved continuous exposure of scallop larvae to the therapeutic agent while the other involved a short exposure lasting two hours. All intermediate scale treatments were performed in parallel to large-scale production (800 L) treatment with chloramphenicol. Of the therapeutants investigated, oxolinic acid was the most effective, although only at high concentrations. The short exposure of two hours was ineffective for all therapeutics.  相似文献   

The efficacy of a single intraperitoneal injection of either flumequine or oxytetracycline hydrochloride in prevention of outbreaks of atypical Aeromonas salmonicida infection in goldsinny wrasse, Ctenolabrus rupestris L., following stress.     

Ole Bent Samuelsen  Arne Ervik  Lise Torkildsen  Øivind Bergh 《Aquaculture International》2002,10(3):257-264

In this investigation, the efficacy of a single intraperitonealinjection of either flumequine or oxytetracycline hydrochloride to preventoutbreak of atypical Aeromonas salmonicida infection ingoldsinny wrasse, Ctenolabrus rupestris, following stresswas studied. Six groups of goldsinny wrasse, each of 50 individuals, weretreated with an intraperitoneal injection of either propylene glycol : saline(50 : 50), 200 mg kg^–1 of oxytetracycline or 50mg kg^–1 of flumequine dissolved in propyleneglycol : saline (50 : 50). Three days following medication the fish in allgroups were stressed by an intraperitoneal injection of prednisolone acetate(0.05 ml) and a rise in seawater temperature from 9 to 11°C. Mortality was observed daily for 21 days. Flumequine wasthe more effective with a mean cumulative mortality of 5% compared tooxytetracycline with 54%. The mean cumulative mortality in the unmedicatedcontrol groups was 84%. Bacterial examination of kidneys from dead fishconfirmed the presence of atypical A. salmonicida as theprobable cause of death. Minimum inhibitory concentration (MIC) values forflumequine and oxytetracycline against the isolated A.salmonicida were determined to 0.13 gml^–1, and 2.0 g ml^–1,respectively.  相似文献