Getting cosy in freshwater: Assumed to be brackish pike are not so brackish after all     

Kim Birnie‐Gauvin  Lasse Birch Hjrup  Theis Kragh  Lene Jacobsen  Kim Aarestrup 《Ecology of Freshwater Fish》2019,28(3):376-384

Pike (Esox lucius) occupy coastal streams and rivers of the Baltic Sea, where they attain large sizes (>5 kg). These large sizes are perhaps due to the fact that they can tolerate relatively high salinities and can thus forage in the nearby more productive brackish environments. In an attempt to quantify the extent to which pike utilise brackish environments, and to provide some insight into the underlying causes for brackish water migrations, we tagged 30 pike from a western Baltic river with acoustic transmitters and were able to track 21 individuals for 1 year. Based on experienced from local anglers, this population was assumed to be brackish in nature, where individuals underwent freshwater migrations to spawn. Our findings however suggest that the smallest and most active individuals make short exits into brackish waters and do so on rare occasions. Our results further indicate that neither sex nor size is related to activity level. We suggest that these patterns reflect two distinct behaviours—active and passive—and that large pike can be supported by the food availability in the river, without the need to venture into coastal zones, thus defying the conventional view that Baltic pike are all brackish in nature.  相似文献   

Effects of phenylbutazone and indomethacin on the post-operative course following experimental orthopaedic surgery in dogs     

Susan W. Mbugua  Lasse A. Skoglund  Per Lkken 《Acta veterinaria Scandinavica》1989,30(1):27-35

Randomized placebo-controlled crossover studies were carried out in dogs to evaluate how two non-steroidal anti-inflammatory drugs (NSAID) might modulate an acute post-traumatic inflammatory reaction. Two "identical" surgical interventions were performed on the forelimbs of each animal with an interval of 28 days, to enable a paired comparison of the inflammatory signs and the wound/bone healing processes. At one operation 8 dogs received 300 mg phenylbutazone twice daily for 8 days starting on the day before surgery, and at the other operation matching placebo tablets were given. In a similar placebo-controlled trial another group of 8 dogs received 5 mg indomethacin twice daily. With phenylbutazone the post-operative swelling was not significantly reduced compared to placebo, but there was less pain and limping. With indomethacin the swelling was somewhat reduced, but there was no consistent difference to placebo in the pain and limping assessments. None of the drugs appeared to distinctly effect the wound or fracture healing, as evaluated by clinical inspection, comparison of radiographs and comparison of bone sections from the sites of surgery. It proved difficult to select an appropriate dosage of indomethacin due to its high potential to induce GI ulceration and bleeding in dogs. In this experimental surgical model with an acute inflammation, neither phenylbutazone nor indomethacin showed impressive anti-inflammatory or analgesic properties. In the same model paracetamol has proved to significantly and more efficiently, reduce both swelling and pain without any noticeable adverse effects, and appears to be a better alternative than the two presently tested NSAID.  相似文献   

The effect of sowing date, stale seedbed, row width and mechanical weed control on weeds and yields of organic winter wheat   总被引：1，自引：0，他引：1  

I A Rasmussen 《Weed Research》2004,44(1):12-20

Three field experiments were carried out in organically grown winter wheat in Denmark. The treatments were sowing time (normal or late sowing) and false seedbed, row width (12 and 24 cm) and weed control method [untreated; mechanical weed control (weed harrowing at 12 cm supplemented with inter‐row hoeing at 24 cm); and herbicide weed control]. Weed biomass in midsummer was greatest on plots sown at the normal sowing time (compared with delayed sowing) and was reduced by mechanical or chemical weed control (compared with untreated plots). Row width alone had no influence on weed biomass, but in the experiment with high weed pressure, the more intensive mechanical weed control used at a row width of 24 cm reduced weed biomass. Normal sowing time tended to give higher yields, but this was only statistically significant in one of the three experiments. Wide rows gave a yield decrease in the experiment with low weed pressure. The effect of weed control on yield was dependent on the weed pressure. At low weed pressure, mechanical weed control caused a yield decrease compared with untreated or herbicide treated. At intermediate weed levels there were no differences, whereas at high weed pressure, mechanical weed control and herbicide treatment caused a yield increase compared with untreated. False seedbeds were shown to contribute to a decrease in the soil seed reserve.  相似文献   

Skin lesions in Aubrac cows strongly associated with fly bites (Haematobia irritans)          下载免费PDF全文

Marion Mosca  Murielle Vabret  Pia Randleff‐Rasmussen  Didier Pin 《Veterinary dermatology》2018,29(3):254-e94

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Effects of cultural methods and physical weed control on intrarow weed numbers, manual weeding and marketable yield in direct-sown leek and bulb onion     

B Melander  & G Rasmussen 《Weed Research》2001,41(6):491-508

Manual weeding of intrarow weeds in direct-sown leek and bulb onion crops grown organically can be very labour-intensive. Four field experiments, two in direct-sown leek and two in direct-sown bulb onion were made in this investigation to study the effects of physical and cultural methods on intrarow weed numbers, time consumption for hand-weeding and marketable yield parameters. The physical methods considered were: pre-emergence flaming and harrowing, and post-emergence hoeing close to the row (only leek) and vertical brush weeding. The cultural methods were: seed priming, slurry placement and cultivar choice (only leek). Generally, flaming plus brush weeding gave the highest intrarow weed control at 92% and 87%, respectively, in the two leek experiments and 39% (only brush weeding was effective) and 74%, respectively, in the two onion experiments. Time consumption for hand-weeding after the different treatments was linearly related to the remaining numbers of intrarow weeds, with no significant influences of the experimental factors on the general relationship. Generally, the cultural methods had no significant influence on the effects of physical weeding in terms of their effect against intrarow weeds. They did not affect the tolerance or robustness of the crop plants against negative impact from the physical control methods. However, generally, seed priming and cultivar choice did improve yield in the leek experiments and seed priming also did so in the one experiment with onion.  相似文献   

Vaccination experiments on pregnant mice with E. coli vaccines prepared from septicaemic and enteropathogenic strains of E. coli     

A Dam 《Acta veterinaria Scandinavica》1973,14(5):691-699

Experiments have been carried out with vaccination of pregnant mice against E. coli, followed by i.p. challenge of the offspring at one week of age.With a septicaemic strain the results were highly significant, and the method is therefore recommendable for testing of vaccines against such strains of E. coli.Results were less clear-cut with enteropathogenic strains of E. coli. However, with mortality rates of 40 to 45 % in baby mice born by non-vaccinated mothers and less than 15 % in baby mice born by vaccinated mothers, the difference in percentage mortality seems sufficient to warrant the use of the method also in the control of vaccines against enteropathogenic E. coli strains.  相似文献   

Concentrations of trimethoprim and sulphadoxine in tissues from goats and a cow.     

P Nielsen  F Rasmussen 《Acta veterinaria Scandinavica》1975,16(3):405-410

The concentration of trimethoprim and sulphadoxine in plasma and tissue from goats and a cow have been determined after a single intravenous injection. Furthermore, the concentration of the two drugs and their metabolites in plasma and tissues have been determined after continuous intravenous infusion for 2½–3 hrs. Trimethoprim was present in all tissues but brain at higher concentrations than in plasma while the concentration of sulphadoxine in the different tissues were lower than in plasma. The highest concentration of the 2 drugs and their metabolites was found in the kidney. The distribution pattern of trimethoprim and sulphadoxine was similar in cow and goats.  相似文献   

Active mammary excretion of N4-acetylated p-aminohippuric acid     

F Rasmussen 《Acta veterinaria Scandinavica》1969,10(2):193-194

Different excretion patterns were observed for p-amino- hippuric acid and its acetylated metabolite in mammary excretion experiments in goats and cows. The excretion of p-aminohippuric acid conformed to passive diffusion of the non-protein bound and un-ionized fraction (Rasmussen 1958, 1966) as described by Miller et al. (1967). Thus, the p-aminohippuric acid (pK_a 3.8) appeared in ultrafiltrates of milk in concentrations 1/4—1/10 of the concentrations in ultrafiltrates of blood plasma. The concentrations of acetylated p-aminohippuric acid (pK_a 3.9) in ultrafiltrates of milk were on the other hand equal to or higher than in ultrafiltrates of blood plasma.  相似文献   

Svend Dalgaard-Mikkelsen     

Rasmussen F 《Historia medicinae veterinariae》2002,27(5-6):329-332

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Reaction of Ptr ToxA-Insensitive Wheat Mutants to Pyrenophora tritici-repentis Race 1     

Friesen TL  Rasmussen JB  Kwon CY  Francl LJ  Meinhardt SW 《Phytopathology》2002,92(1):38-42

ABSTRACT The host-selective toxin Ptr ToxA is produced by races 1 and 2 of Pyrenophora tritici-repentis, causal agent of tan spot of wheat. Ptr ToxA has been causally associated with pathogenicity by the race 2 phenotype in this system. However, the role of toxin in disease caused by race 1, the most prevalent form of the fungus in the central and northern Great Plains of North America, has not been rigorously investigated. Three independent wheat lines harboring mutations for insensitivity to Ptr ToxA were derived from ethylmethane sulfonate treatment of the hard red spring wheat cv. Kulm, possessing the single dominant gene for toxin sensitivity. Each of the three mutants was insensitive to Ptr ToxA in bioassays based on necrosis development and electrolyte leakage. Each mutant was crossed to each of the other mutants and to the wild-type Kulm. Segregation data indicate that each mutant line harbors a single recessive mutation for toxin insensitivity that maps to or near the same locus, possibly the toxin-sensitivity gene. Each toxin-insensitive mutant line was susceptible to two isolates of race 1 of P. tritici-repentis. F(2) and F(3) generations derived from crosses between Kulm and each mutant segregated for toxin reaction. However, segregation for fungal reaction was not evident, and all F(3) families were tan spot susceptible regardless of toxin reaction. Host insensitivity to Ptr ToxA is not necessarily equivalent to resistance to race 1. Ptr ToxA should not be used alone as a proxy for fungal inoculations by breeding programs aimed at developing tan spot-resistant wheat.  相似文献