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1.
在丘陵红壤橘园上．经过3年6种地面管理措施的经济生态效益研究。结果表明：（1）水土流失，以清耕法作对照，生草法、克无踪、草甘膦、草草克、克克草的地表径流量可显著减少分别为38．8％．42．5％．18，7％，28．7％和37．5％；土壤侵蚀量可显著减少分别为55．5‰，51．7％．39．9％．46．8％和50．0％；流失的氮磷钾养分总量可分别减少60．3％．50．2％，37．0％．41．8％和45．4％。（2）杂草再生率，以生草法做对照，则处理中的清耕法、克无踪、草甘膦、草草克和克克草分别是生草法的55．1%．67．2％．30．3％．36．8％和51．2％。（3）土壤肥力，以土壤OM，N,P2O3,K2O总量增减率看，清耕法为-4．4%,生草法7．1％，克无踪6．9％，草甘膦5．3％．克克草6．2％．草草克6．6％。（4）柑橘的产量和品质，以清耕法作对照，除生草法外，克无踪、草甘膦、草草克、克克草均增产7％～10％；可溶性固形物、总糖量、总酸度、糖酸比以及单果重均达到显著差异水平。克无踪调控杂草效果显著．可作为丘陵红壤丘陵园地水保与培肥兼得的有效地面管理措施。 相似文献
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MIN SU LEE JEFF KO AH RA LEE IN HYE LEE MI AE JUNG BRENDA AUSTIN HYUNWOO CHUNG SANGSOEP NAHM KIDONG EOM 《Veterinary radiology & ultrasound》2010,51(2):130-135
The purpose of this study was to assess the effects of four anesthetic protocols on normal canine brain uptake of 2‐deoxy‐2‐[18F]fluoro‐d ‐glucose (FDG) using positron emission tomography/computed tomography (PET/CT). Five clinically normal beagle dogs were anesthetized with (1) propofol/isoflurane, (2) medetomidine/pentobarbital, (3) xylazine/ketamine, and (4) medetomidine/tiletamine–zolazepam in a randomized cross‐over design. The standard uptake value (SUV) of FDG was obtained in the frontal, parietal, temporal and occipital lobes, cerebellum, brainstem and whole brain, and compared within and between anesthetic protocols using the Friedman test with significance set at P<0.05. Significant differences in SUVs were observed in various part of the brain associated with each anesthetic protocol. The SUV for the frontal and occipital lobes was significantly higher than in the brainstem in all dogs. Dogs receiving medetomidine/tiletamine–zolazepam also had significantly higher whole brain SUVs than the propofol/isoflurane group. We concluded that each anesthetic protocol exerted a different regional brain glucose uptake pattern. As a result, when comparing brain glucose uptake using PET/CT, one should consider the effects of anesthetic protocols on different regions of the glucose uptake in the dog's brain. 相似文献
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KENT E. SULLIVAN vmd JACK R. SNYDER dvm PhD Dipiomate ACVS JOHN E. MADIGAN DVM MS Dipiomate ACVIM JOHN R. PASCOE BVSc PhD Dipiomate ACVS THOMAS B. FARVER PhD MARK C. THURMOND dvm PhD JEFF W. ANDRESEN PhD 《Veterinary surgery : VS》1993,22(5):343-350
Granulocyte colony-stimulating factor (G-CSF) is a glycoprotein that regulates the proliferation and maturation of hematopoietic progenitor cells and modulates the function of mature neu-trophils. The responses to administration of G-CSF alone, and in combination with antimicrobials, were studied in an equine model of ascending colon ischemia. Complete segmental colonic ischemia (3.75 hours) with pelvic flexure enterotomy was created in four treatment groups. Group 1 horses received recombinant canine G-CSF (10 μg/kg, every 24 hours, intramuscularly), gentamicin sulfate (2.2 mg/kg, every 8 hours, intravenously), and potassium penicillin G (40,000 lU/kg, every 6 hours, intravenously). Group 2 horses were treated with the G-CSF vehicle and antimicrobials as for group 1. Group 3 horses received G-CSF and the antimicrobial drug vehicles, and group 4 horses served as the untreated control receiving G-CSF vehicle and antimicrobial vehicles. The results for 20 horses, five horses in each group, were compared. Treatment with G-CSF was associated with an increased concentration of white blood cells, band neutrophils, neutrophils, lymphocytes, and monocytes in the peripheral blood after surgery. Antimicrobial administration had no detectable effect on cell concentrations after surgery. Administration of G-CSF was associated with an increased concentration of nucleated cells in the peritoneal fluid including neutrophils, small mononuclear cells and large mononuclear cells. Horses that developed incisional infections had lower neutrophil concentrations in the peripheral blood on postoperative day 2 than horses without infected incisions. These results suggested that the prophylactic administration of G-CSF may be useful in the treatment of patients at risk for developing neutropenia after surgery. 相似文献
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IRINA POLLARD SUSAN WILLIAMSON JEFF DOWNING REX SCARAMUZZI† 《Journal of veterinary pharmacology and therapeutics》1996,19(2):113-117
The disposition kinetics of caffeine and its metabolites theophylline, theobro-mine and paraxanthine in the oestrogen-implanted ovariectomized ewe following single intravenous doses of 5, 10, 15 or 20 mg/kg caffeine are described in this paper. Blood was collected at 5, 30 and 60 min, and at 3, 6, 8, 12, 24, 48, 72, 96, 120, 144, 192 and 240 h after dosing. Caffeine concentrations peaked within 30 min of administration but remained in a plateau phase for 3-6 h before declining over a prolonged period of time. For caffeine the mean elimination half-life was calculated to be 47 h. Detectable caffeine concentrations remained for 10 days after administration in all groups. The area under the plasma concentration-time curve ( AUC ) values were used to compare tissue caffeine exposure and were, approximately, linearly related to dose. Metabolite concentrations were maintained at peak and near peak concentrations for 6-24 h after caffeine administration followed by prolonged elimination. Because of significant species differences in drug elimination rates, it is concluded that the ewe is not a suitable animal model in the clinical context. However, the sheep may well provide insights into caffeine's mechanism of action of relevance to veterinary drug research. 相似文献
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The PROFILE model is used extensively in the European Critical Loads programme as an aid to international negotiations on SO2 emission abatement. PROFILE calculates the rates of cation release by mineral weathering and it then uses these data to calculate soil solution and runoff chemistry. No independent assessment of the underlying assumptions and data in the model has been published and this paper reports such an assessment. The rate equations, which are the key to the PROFILE model require rate coefficients and constants. These have been derived from the literature but more work is required to produce a consistent set of constants. Manipulation of these rates to take into account the exposed reactive surface area of the minerals is fraught with problems. Calculation of exposed mineral surface area from soil textural data results in under-estimates and the requirement to determine the surface area fraction of the different minerals in the soil to be known is extremely difficult if not impossible. Further uncertainty is introduced by adjustment of the rates to take into account temperature differences and by the use of a default mineralogy which is compositionally unrealistic. Despite its flaws PROFILE usually predicts similar weathering rates to other methods of calculation. It is argued that the unrealistic constraints imposed by the use of the surface area equation may be responsible for limiting calculated weathering rate to a fixed range which coincides with characteristically determined values for weathering rates. 相似文献
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HANWEN WU STEVE WALKER MICHAEL JONATHAN ROLLIN DANIEL KEAN YUEN TAN GEOFF ROBINSON JEFF WERTH 《Weed Biology and Management》2007,7(3):192-199
Flaxleaf fleabane ( Conyza bonariensis [L.] Cronquist) is a difficult-to-control weed in dryland minimum tillage farming systems in the northern grains region of Australia. Experiments under field and controlled environments were conducted to study the seed germination, emergence, and persistence of C. bonariensis . The base, optimum, and maximum temperatures for seedling germination were estimated at 4.2, 20, and 35°C, respectively, with light stimulating germination. The soil types and burial depths had significant effects on seed persistence and emergence. The persistence pattern showed an initial rapid drop, followed by a slow but steady decline over time. After 3 years of burial, there were ≈ 7.5%, 9.7%, and 1.3% viable seeds at 10, 5, and 0–2 cm soil depths, respectively. Conyza bonariensis predominantly emerged from the soil surface or from the burial depth of 0.5 cm. Very few seeds emerged from a depth of 1 cm and none emerged from ≥ 2 cm. The emergence was greater in lighter soils. On-farm monitoring of the field emergence over time in a light sandy loam soil showed that 99% emergence occurred in late autumn, early and late winter, and a small fraction of 1% emerged in mid-spring. The predominant emergence from the soil surface suggests that the fleabane problem is a result of weed species shift toward the minimum tillage systems that provide moist conditions for better emergence compared to conventional tillage systems. The seed longevity of at least 3 years in the soil and the prolonged emergence patterns between autumn and spring have posed great difficulties for the long-term management of C. bonariensis . 相似文献
7.
JEFF I. WEINSTEIN SARAH PAYNE JEAN M. POULSON CHIEKO AZUMA 《Veterinary radiology & ultrasound》2009,50(6):673-678
A standard of therapy for osteosarcoma includes amputation with or without adjuvant chemotherapy. There is a subset of dogs with osteosarcoma that are unsuitable for amputation. We evaluated kinetic variables in dogs with appendicular osteosarcoma treated with a single 8 Gy dose of radiation. Eighteen pet dogs with appendicular osteosarcoma received one 8 Gy fraction of palliative radiation on day 0. Force plate measurements and clinical assessments were made on days 0, 7, 14, and 21. Peak vertical forces ( F z ) were recorded for each limb and a symmetric index (SI) was calculated. There were no significant changes in kinetic parameters after one 8 Gy dose of radiation therapy. Nine of these 18 dogs exhibited increased limb function at day 21 based on force plate analysis. Significant factors affecting F z included gender and tumor location. There was a significant correlation between F z and response to therapy based on SI at day 21. SI seems to be useful to objectively assess response in this mixed population of dogs. One 8 Gy fraction of radiation therapy alone did not reduce lameness associated with appendicular osteosarcoma, but a subset of dogs did have improved limb function after a single dose. 相似文献
8.
RICHARD B. PAGE PETER V. SCRIVANI NATHAN L. DYKES HOLLIS N. ERB JEFF M. HOBBS 《Veterinary radiology & ultrasound》2006,47(2):206-211
Our purpose was to determine the accuracy of increased thyroid activity for diagnosing hyperthyroidism in cats suspected of having that disease during pertechnetate scintigraphy using subcutaneous rather than intravenous radioisotope administration. Increased thyroid activity was determined by two methods: the thyroid:salivary ratio (T:S) and visual inspection. These assessments were made on the ventral scintigram of the head and neck. Scintigraphy was performed by injecting sodium pertechnetate (111 MBq, SQ) in the right-dorsal-lumbar region; static-acquisition images were obtained 20 min after injection. We used 49 cats; 34 (69%) had hyperthyroidism based on serum-chemistry analysis. Using a Wilcoxon's rank-sum test, a significant difference (P < 0.0001) was detected in the T:S between cats with and without hyperthyroidism. Using a decision criterion of 2.0 for the T:S, the test accurately predicted hyperthyroidism in 32/34 cats (sensitivity, 94%; 95% confidence interval (CI), 85-100%) and correctly predicted that hyperthyroidism was absent in 15/15 cats (specificity, 100%; CI, 97-100%). Using visual inspection, the test accurately predicted hyperthyroidism in 34/34 cats (sensitivity, 100%; CI, 99-100%) and correctly predicted that hyperthyroidism was absent in 12/15 cats (specificity, 80%; CI, 56-100%). The positive and negative predictive values were high for a wide range of prevalence of hyperthyroidism. And, the test had excellent agreement within and between examiners. Therefore, detecting increased thyroid activity during pertechnetate scintigraphy by subcutaneous injection is an accurate and reproducible test for feline hyperthyroidism. 相似文献
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Sequential applications of glyphosate followed by another postemergent herbicide, known as the "double knock" technique, were trialled for their effectiveness in controlling Conyza bonariensis . Combinations of glyphosate with and without 2,4-D followed by paraquat plus diquat, paraquat, or 2,4-D were tested at a range of follow-up application times in two field and two pot experiments. The results showed that paraquat plus diquat or paraquat following glyphosate or glyphosate plus 2,4-D provided highly effective weed control compared to glyphosate alone. The optimum timing for follow-up applications of paraquat or paraquat plus diquat was between 5 and 7 days after the initial glyphosate application. Combined applications of glyphosate and 2,4-D, compared to split applications, were not significantly different. However, following glyphosate application with 2,4-D >1 day later considerably reduced the level of control. This study showed that the double knock technique is highly effective in controlling C. bonariensis and is rapidly becoming an important tool in the management of this problem weed. 相似文献