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31.
Watershed development may alter tributaries in ways that influence the growth and development of juvenile fish. For Rainbow Trout Oncorhynchus mykiss, the extent of land cover influence on the diet composition of stream‐residing juveniles is still an open but important question, particularly given their broad global distribution. Our study evaluated the effect of land cover on diet composition and condition metrics of juvenile Rainbow Trout in Lake Michigan tributaries. Juveniles were collected in the fall of 2014 and 2015 from 18 sampling locations across the Lake Michigan basin and included a wide variety of land cover types. Multivariate statistical procedures were used to quantitatively score sites along axes that maximized variation in land cover and diet composition. Subsequently, Spearman's rank correlations were used to test for significance of correlations between (a) land cover and diet composition, (b) land cover and fish condition, and (c) diet composition and fish condition. Our results indicated that land cover had an influence on the diet compositions of juvenile Rainbow Trout, but neither land cover nor diet composition had a significant influence on Rainbow Trout condition. These findings contrast with previously published work focusing on the growth responses of other fish species and provide insight into the plastic nature of Rainbow Trout. Further, we discuss potential ways in which fish may mitigate the effect of land cover changes as they are transmitted through stream food webs; however, the magnitude of the mitigation likely varies among fish species.  相似文献   
32.
Disseminated pulmonary and subcutaneous-muscular hemangiosarcoma at the left hemimandible was diagnosed postmortem in a 2-year-old Jersey bull that presented with a 7-day history of facial swelling from suspected traumatic injury. Hemangiosarcoma is uncommon in cattle and has never been reported to affect the bones of the skull.  相似文献   
33.
A number of anthelmintics are available for the control of gastrointestinal nematodes in cattle. In North America, O. ostertagi, Cooperia spp., lung worm, and F. hepatica probably cause the greatest losses in production. The older anthelmintics are often deficient in their action against some of these parasites. Recently, the Paratect morantel tartrate slow-release bolus has provided a mechanism for the prevention of infections with gastrointestinal nematodes and lung worm, to some extent, and this has been shown to produce considerable economic benefits. Fenbendazole removes arrested O. ostertagi larvae; thus, its availability is an important step in the prevention of type-2 ostertagiasis. It also has a very broad spectrum of activity that includes most other nematodes and tapeworms and is a very safe anthelmintic. Ivermectin is highly effective against almost all cattle nematodes and also has great value for the control of arthropod ectoparasites. In addition, it and levamisole are the only anti-nematode drugs that can be administered to cattle by injection. Clorsulon is a new, safe anthelmintic that provides good control of liver fluke and, thus, fills a gap in the control of helminths of cattle in North America. The efficient use of anthelmintics in association with management based on a knowledge of parasite epidemiology can ensure that cattle do not rapidly become re-infected. In this way, the benefits from the use of anthelmintics can be very considerable and far greater than the costs of control.  相似文献   
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35.
Data from the Global Oscillation Network Group (GONG) project and other helioseismic experiments provide a test for models of stellar interiors and for the thermodynamic and radiative properties, on which the models depend, of matter under the extreme conditions found in the sun. Current models are in agreement with the helioseismic inferences, which suggests, for example, that the disagreement between the predicted and observed fluxes of neutrinos from the sun is not caused by errors in the models. However, the GONG data reveal subtle errors in the models, such as an excess in sound speed just beneath the convection zone. These discrepancies indicate effects that have so far not been correctly accounted for; for example, it is plausible that the sound-speed differences reflect weak mixing in stellar interiors, of potential importance to the overall evolution of stars and ultimately to estimates of the age of the galaxy based on stellar evolution calculations.  相似文献   
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37.
The origin of the World Association for the Advancement of Veterinary Parasitology (WAAVP) African Foundation is described. The 16th WAAVP Conference held in South Africa in 1997 generated a surplus of ZAR 430 460 (US$ 70 116). This was invested and a foundation established to manage the fund with the intention of using it to the mutual advantage of the WAAVP and African veterinary parasitologists. To date, more than 110 scholarship applications have been screened, and 51 full and partial scholarships awarded to young African veterinary parasitologists to attend subsequent biennial WAAVP Conferences. This investment has grown into a very successful endowment currently valued at US$ 206 553. This article is written in response to many queries across the globe about the origin of this fund and how it has been invested, managed, sustained and utilised.  相似文献   
38.
The influence of methimazole on the plasma disposition kinetics of fenbendazole, oxfendazole and their metabolites, was investigated in adult sheep. The two anthelmintics were administered by oral drench at 5 mg kg−1 either alone (control treatments) or together with methimazole given orally at 3 mg kg−1. Blood samples were taken serially for 144 hours. Fenbendazole parent drug and its sulphoxide and sulphone metabolites were the three analytes observed by high performance liquid chromatography ( ) after the administration of both anthelmintics. The disposition of each analyte followed a similar pattern after the administration of the two anthehnintics alone. Oxfendazole was the main component recovered in plasma between four and 120 to 144 hours after the administration of both anthelmintics either with or without methimazole. A modified pattern of disposition, with significantly higher Cmax and values for fenbendazole parent drug, and a delayed appearance in plasma with retarded Tmax values for the sulphoxide and sulphone metabolites, were the main pharmacokinetic changes observed when the drugs were administered with methimazole.  相似文献   
39.
Canine histiocytic ulcerative colitis   总被引:1,自引:0,他引:1  
Objective To assess prevalence, breed predilection, response to therapy and prognosis of canine histiocytic ulcerative colitis (CHUC).
Design A retrospective study of cases of CHUC seen at Sydney University Veterinary Teaching Hospital (SUVTH) over a 20-year period (1975 -1994).
Procedure Case records of all dogs in which colitis was suspected were reviewed. Dogs were diagnosed with CHUC based on colonorectal biopsy and histopathological examination.
Results CHUC was diagnosed in 8 of 57 dogs presented for colitis. All affected dogs were Boxers and six were female. Dogs with milder clinical signs showed moderately good response to therapy. Four dogs were still alive 1 to 7 years after diagnosis. Three dogs were euthanased, one for reasons other than CHUC, and one was lost to follow-up.
Conclusions Young boxer dogs with relatively mild signs of CHUC may respond moderately well to medical and dietary therapy with fair prognosis. Euthanasia early in the course of the disease may be unwarranted. Prevalence may be increasing within the SUVTH referral population.  相似文献   
40.
The effects of methimazole (MTZ), metyrapone (MTP) and quinine (QNE) on the pharmacokinetics and bioavailability of parenterally administered netobimin (NTB) and its major metabolites, albendazole sulphoxide (ABZSO) and albendazole sulphone (ABZSO2), were studied in sheep. NTB trisamine solution was first administered alone at 20 mg kg-1 by subcutaneous injection and then coadministered with either MTZ (1.5 mg kg-1 intramuscularly), MTP (20 mg kg-1 subcutaneously) or QNE (30 mg kg-1 intraruminally) in adult sheep. Blood samples were taken serially over a 120 hour period and plasma was analysed for NTB and its metabolites by high performance liquid chromatography. NTB parent drug showed a similar pharmacokinetic behaviour after all parenteral treatments. Both ABZSO AUCs (P less than 0.01) and Cmax (P less than 0.05) were significantly higher in the presence of MTZ and MTP than with the treatment with NTB alone. In the presence of each of the oxidation inhibitor compounds, the ratio of AUC ABZSO/ABZSO2 was significantly higher than with the NTB alone treatment. It has been demonstrated that the coadministration of substances which alter liver microsomal oxidation resulted in a modified pharmacokinetic pattern for the metabolites of NTB. Both NTB + MTZ and NTB + MTP treatments resulted in an improved pharmacokinetic profile for the anthelmintically active ABZSO metabolite.  相似文献   
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