Reduction of deer browsing of Douglas-fir (Pseudotsuga menziesii) seedlings by quadrivalent selenium     

G.G. Allan  D.I. Gustafson  R.A. Mikels  J.M. Miller  S. Neogi 《Forest Ecology and Management》1984,7(3):163-181

The feasibility of using selenite ion as a systemic deer repellent for the protection of Douglas-fir (Pseudotsuga menziesii) seedlings is evaluated. When applied to the soil, the selenite ion is absorbed by the seedling roots, transported to the foliage, and thereafter volatilized. Acute phytotoxicity is observed only when selenium foliar concentrations exceed 100 ppm, while animal repellency is demonstrated at concentrations as low as 1–2 ppm. The design of a slow release device, based on a sparingly soluble salt of selenious acid, is reported, and its evaluation in a series of field trials is described. Preliminary results indicate that statistically significant reduction of browse damage can be achieved.  相似文献   

Distribution and population genetic structure of river- and sea-type sockeye salmon in western North America     

R. G. Gustafson  G. A. Winans 《Ecology of Freshwater Fish》1999,8(3):181-193

Abstract– In contrast to the well-known "lake-type" sockeye salmon, two additional anadromous life-history types have been recognized within the species: 'river-type' sockeye salmon whose juveniles spend 1 or 2 years in off-channel river habitats prior to migrating to sea, and "sea-type" sockeye salmon that initially rear in similar river habitats yet migrate to sea as underyearlings. Persistent populations of river-/sea-type sockeye salmon occur in small numbers throughout the species'range in North America but are usually associated with glacier-fed rivers. We found published and unpublished records showing that riverine-spawning sockeye salmon occur in 11 rivers in western Washington, USA, that don't have access to juvenile lake-rearing habitat. Evidence of persistent spawning was strongest for the Nooksack and Skagit rivers in northern Puget Sound. We analyzed allozyme frequency differentiation in 26 laketype and 12 river-/sea-type populations of sockeye salmon in North America, ranging from northern Puget Sound, Washington (including 3 in the Nooksack and Skagit rivers) to northern Southeast Alaska. Across this 2000 km range, river-/sea-type sockeye salmon showed very little genetic differentiation between populations, much less than that displayed by the highly divergent lake-type sockeye salmon. Genetic similarity among river-/sea-type sockeye salmon in this study is likely a result of common ancestry and a high level of historical gene flow among river-/sea-type sockeye salmon populations.  相似文献   

Host perception and signal transduction studies in wild-type Blumeria graminis f. sp. hordei and a quinoxyfen-resistant mutant implicate quinoxyfen in the inhibition of serine esterase activity     

Lee S  Gustafson G  Skamnioti P  Baloch R  Gurr S 《Pest management science》2008,64(5):544-555

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Conservative management of uroperitoneum in a gelding.     

K T Gibson  G W Trotter  S B Gustafson 《Journal of the American Veterinary Medical Association》1992,200(11):1692-1694

Uroperitoneum as a sequela to urethral calculus in an adult gelding was successfully managed by use of subischial urethrotomy and abdominal drainage. Necrosis of bladder mucosa was seen endoscopically, but a tear or rupture was never identified. Peritonitis developed but was controlled with antibacterial treatment. Although uroperitoneum is usually a sequela to bladder rupture and the ideal treatment is surgical repair, conservative management may be warranted in selected cases.  相似文献   

Skeletal muscle perfusion during prolonged 2.03% end-tidal isoflurane-O2 anesthesia in isocapnic ponies     

M Manohar  R Gustafson  D Nganwa 《American journal of veterinary research》1987,48(6):946-951

Effects of 1.55 minimum alveolar concentration isoflurane O2 anesthesia (2.03% end-tidal isoflurane) on blood flow in the up-(nondependent) and down-(dependent) positioned skeletal muscles were studied at 60, 120, and 180 minutes in 6 healthy isocapnic ponies in right lateral recumbency on a nonpadded hardwood floor. Measurements were made, using 15-micron diameter radionuclide-labeled microspheres injected into the left ventricle, and comparisons were made with data obtained from ponies in the conscious state. Isoflurane administration caused a sharp reduction in cardiac output and systemic pressure (P less than 0.01), but total peripheral resistance did not change significantly. In the triceps brachii, gluteus medius, biceps femoris, and vastus lateralis of both sides, blood flow decreased significantly during 1.55 minimum alveolar concentration isoflurane anesthesia (P less than 0.01), and fluctuations did not occur with increasing duration of anesthesia. In masseter muscles, perfusion values during the 3 hours of anesthesia were not significantly different from values in awake ponies. Despite the fact that 4 ponies developed marked edema of the dependent masseter muscle, 1 pony without masseter edema developed postanesthetic forelimb lameness and 2 of the 4 ponies with masseter edema had generalized hind limb weakness after anesthesia; significant differences in blood flow between up- and down-positioned muscles were not observed. During isoflurane-O2 anesthesia in ponies, a sharp significant decrease in skeletal muscle blood flow was observed (P less than 0.01). Decreased equine skeletal muscle perfusion during isoflurane anesthesia also may be accompanied by accentuated O2 loss from the arterial blood via the countercurrent O2 exchange between large arterioles and venules.  相似文献   

Further investigations into the potentiation of infection by intra-articular injection of polysulfated glycosaminoglycan and the effect of filtration and intra-articular injection of amikacin     

S B Gustafson  C W McIlwraith  R L Jones  H E Dixon-White 《American journal of veterinary research》1989,50(12):2018-2022

Polysulfated glycosaminoglycan (PSGAG) recently have been reported to potentiate the infectivity of Staphylococcus aureus in horses with experimentally induced septic arthritis. Four groups of 8 horses each had 1 midcarpal joint injected with approximately 33 viable colony-forming units (CFU) of S aureus plus either 1 ml of saline solution (group 1), 250 mg of PSGAG (group 2), 250 mg of PSGAG passed through a 0.6-microns filter (group 3), or 250 mg of PSGAG plus 125 mg of amikacin (group 4). Horses that developed clinical signs consistent with sepsis were euthanatized, and samples were collected at necropsy. Horses that survived had samples obtained by use of arthroscopy at days 13 and 14 after injection. Staphylococcus aureus was isolated from 1 group-1 horse, 8 group-2 horses, and 7 of 7 group-3 horses that met protocol, but was not isolated from any group-4 horses. All 16 aforementioned horses had clinical signs, results of synovial fluid analysis, and gross pathologic and synovial membrane histopathologic findings that were consistent with septic arthritis. Polysulfated glycosaminoglycan (250 mg) increased the infectivity of 33 CFU of S aureus (P = 0.001); filtering the PSGAG had no effect. Intra-articular injection of 125 mg of amikacin immediately after inoculating the joint with 33 CFU of S aureus significantly (P = 0.001) decreased potentiation of infection by the PSGAG.  相似文献   

Effects of daily exercise on the health of tied dairy cows     

G. M. Gustafson 《Preventive veterinary medicine》1993,17(3-4):209-223

The effect of daily exercise on tied dairy cows was ied in 65 initially first and second calvers of the Swedish Red and White dual-purpose breed in a 4 year experiment, starting in July 1985. Half of the group walked outdoors for 2–3 km day⁻¹ from May to October and 400–800 m day⁻¹ from November to April. The rest of the cows were constantly tied. Health in general was significantly and positively influenced by exercise, reducing the need for veterinary treatments. Analysis over time, within lactations, showed that the difference in the number of veterinary treatments occured entirely in Weeks 0–2 of lactation. During those weeks, non-exercised (NE) cows were more affected by calving-related diseases, mastitis and leg problems than the exercised (E) cows. The difference between groups increased with increasing lactation number. In addition, somatic cell count in the milk was higher for the NE cows in their first month of lactation. Among feeding-related diseases, the cases of bloat were notably more frequent among NE cows, whereas exercise did not influence the occurence of clinical or subclinical ketosis. Cases of non-infectious leg and hoof disorders were also notably more frequent in the NE group, which also showed a significantly more serious score for skin lesions on the hocks, measured on one occasion. Scores for sole ulcer were significantly higher for the E cows on one occasion of four, at which there were problems with the surface of the exercise area. The causes of exclusions strengthened the differences mentioned for treatments.  相似文献   

Procedures for the elimination of pseudorabies virus from herds of swine   总被引：2，自引：0，他引：2  

D G Thawley  D P Gustafson  G W Beran 《Journal of the American Veterinary Medical Association》1982,181(12):1513-1518

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Resistance of porcine preimplantation embryos to pseudorabies virus   总被引：1，自引：0，他引：1  

S R Bolin  L J Runnels  C A Sawyer  K J Atcheson  D P Gustafson 《American journal of veterinary research》1981,42(10):1711-1712

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PHARMACOKINETICS OF SINGLE-DOSE BUPRENORPHINE,BUTORPHANOL, AND HYDROMORPHONE IN THE DOMESTIC FERRET (MUSTELA PUTORIUS FURO)     

Julia E. Katzenbach  Luke A. Wittenburg  Sandra I. Allweiler  Daniel L. Gustafson  Matthew S. Johnston 《Journal of Exotic Pet Medicine》2018,27(2):95-102

The objective of this study was to establish the clinical pharmacokinetic profile of 4 different opioid drugs (buprenorphine, butorphanol, hydromorphone, and morphine) in the domestic ferret (Mustela putorius furo). Twenty-four, approximately 1-year-old, male neutered purpose-bred domestic ferrets were used for this study. The ferrets were divided into 4 groups of 6, with a different opioid drug used for each group. A preopioid venous blood sample was obtained via cranial vena cava venipuncture. Following the initial blood collection, a single injection of opioid (hydromorphone 0.1 mg/kg, buprenorphine 0.04 mg/kg, butorphanol 0.3 mg/kg, and morphine 1 mg/kg) was given to each ferret, dependent on assigned drug group, intramuscularly (buprenorphine) or subcutaneously (hydromorphone, butorphanol, and morphine). Intramuscular injections were administered in the semimembranosis and semitendinosis muscles, whereas the subcutaneous injections were delivered in the intrascapular subcutaneous space. A venous blood sample was obtained at 5, 15, 30, 60, 120, 240, 360, 480, and 720 minutes postinjection from the ferrets in the buprenorphine, butorphanol, and hydromorphone groups. Mass spectrometry and liquid chromatography was performed to obtain plasma concentrations of the administered drugs. The mean maximum concentration of buprenorphine was 6.96 ng/mL, butorphanol was 48.6 ng/mL, and hydromorphone was 17.3 ng/mL. Maximum concentrations were achieved at a mean of 9 minutes after administration for buprenorphine, 13.3 minutes for butorphanol, and 8.33 minutes for hydromorphone. The mean half-life of buprenorphine was 219.1 minutes, butorphanol was 91.1 minutes, and hydromorphone was 24.7 minutes. Owing to severe complications arising within the morphine group, including hypersalivation and vomiting, the morphine study was discontinued prior to blood sample collection. Intramuscular injections of buprenorphine and subcutaneous injections of butorphanol or hydromorphone appeared to be well tolerated by all ferrets. The pharmacokinetics of buprenorphine, butorphanol, and hydromorphone of a single equipotent dose of each drug have been established through this research investigation and may be useful for further studies.  相似文献