The effects of stubble burning and tillage on soil carbon sequestration and crop productivity in southeastern Australia     

K.Y. Chan  D.P. Heenan 《Soil Use and Management》2005,21(4):427-431

Abstract. In Australia, stubble burning and tillage are two of the major processes responsible for the decline of soil organic carbon concentration in cropped soils, and the resulting soil degradation. However, the relative importance of these two practices in influencing the soil organic carbon concentration and the long-term impact on soil quality and productivity are not clear. The effects of stubble burning as practised by farmers in southeastern Australia were evaluated in two field trials, one of 19 years duration, the other of 5 years. Conventional tillage (three tillage passes) led to greater loss of soil organic carbon than stubble burning. Loss of total soil organic carbon attributed to stubble burning in the 0–10 cm layer was estimated to be 1.75 t C ha⁻¹ over the period of the 19-year trial, equivalent to 29% of that lost due to tillage. In the 5-year trial, no change in soil organic carbon due to stubble burning was detectable. Changes in soil quality associated with stubble burning detected in the longer trial included a reduction in macro-aggregate stability, and increases in pH and exchangeable K⁺. Only the latter two were detected in the shorter trial. A higher mean wheat yield (average 0.15 t ha⁻¹) following stubble burning was observed in the 19-year trial but not in the 5-year trial. Research to monitor the longer term effects of stubble burning is needed, and to identify conditions where loss of soil organic carbon is minimized.  相似文献   

Experience with Cyclosporin-A After Renal Allografting in Two Dogs Research Note     

C. R. GREGORY dvm  I. M. GOURLEY dvm  PhD  Diplomateacvs  N. J. TAYLOR bs  J. M. CULLEN vmd  A. EVANS dvm  L. J. ISAAC aht  L. D. COWGILL dvm 《Veterinary surgery : VS》1986,15(6):441-443

After renal allografting, cyclosporin-A was administered to one partially nonmatched dog that was followed for 79 days. Cyclosporin-A and prednisolone were administered to one nonmatched dog that was followed for 805 days. Side effects encountered with cyclosporin-A included lymphocytic dermatitis, papillomatosis, bacterial and fungal infections, and B lymphocyte hyperplasia.  相似文献   

A practical method for determining the susceptibility of aquatic Vibrio and Aeromonas spp. to antibacterial agents     

A. Colorni 《Aquaculture (Amsterdam, Netherlands)》1985,46(3):263-266

A practical dilution method for determining the degree of susceptibility of aquatic Vibrio and Aeromonas spp. to antibacterial agents is described. The method utilizes the differential ability of these two genera to ferment glucose. Acidification produced by the bacterial metabolism is demonstrated by the color change of an indicator (bromthymol blue) from blue-green to bright yellow. Where bacteria are inhibited by a sufficient concentration of the antibacterial drug tested, no color change occurs. The accurate quantitative results obtained with this method facilitate proper therapy for diseased fish, shrimps and oysters. The same method can in principle be applied to any other glucose-fermenting bacteria, when challenged with non-acidic antibacterial agents.  相似文献   

Serologic response and lesions in goats experimentally infected with Corynebacterium pseudotuberculosis of caprine and equine origins   总被引：2，自引：0，他引：2  

C C Brown  H J Olander  E L Biberstein  D Moreno 《American journal of veterinary research》1985,46(11):2322-2326

Fifteen goat kids were experimentally inoculated with Corynebacterium pseudotuberculosis. Five were given a strain of caprine origin (nitrate-negative biotype) intradermally, 5 were given a strain of equine origin (nitrate-positive biotype) intradermally, and 5 were inoculated intranasally with the caprine-origin strain. Animals were monitored for 127 days. The goats given the inocula intradermally developed abscesses; those given caprine-origin strain had multiple lesions both peripherally and in visceral locations (primarily endothoracic abscesses), whereas those given the equine-origin strain had abscesses only at injection sites and draining nodes. The difference in extent of lesions could be due to biotypic bacterial differences or to the individual strains used. Intranasally inoculated goats did not develop abscesses and were essentially no different from controls. The cranial part of the respiratory tract may not be an important portal of entry for C pseudotuberculosis. Serum samples obtained monthly from all animals were subjected to the synergistic hemolysis-inhibition test, which measures antibodies to the exotoxin of C pseudotuberculosis. Animals with abscesses developed titers within 1 month of inoculation. Animals without abscesses remained seronegative. The synergistic hemolysis-inhibition test may be a reliable diagnostic assay for caseous lymphadenitis in goats.  相似文献   

High frequency ventilation of the lungs: A Review     

Christopher J. Seymour 《Veterinary anaesthesia and analgesia》1986,14(1):169-176

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Canine liposarcoma   总被引：1，自引：0，他引：1  

A R Doster  M J Tomlinson  E A Mahaffey  C W Jordan 《Veterinary pathology》1986,23(1):84-87

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The Quality of Education,Educational Institutions,and Cross‐Country Differences in Human Capital Accumulation     

SHAWN D. KNABB  CHRISTIANA STODDARD 《Growth and change》2005,36(3):354-373

ABSTRACT Cross‐country studies of education and economic prosperity often reach conflicting results when using growth rates as the measure of economic development. However, growth rates lack persistence over time and may not accurately measure long‐term economic success over relatively short economic horizons. To overcome this potential specification problem, we estimate the relationship between key education variables and the capital to physical labor ratio. Using both cross‐sectional and panel specifications, we find that both the primary‐pupil–teacher ratio and decentralized education finance are associated with a larger capital to physical labor ratio. The relationship between human capital and expenditures, private education, and test scores are less robust.  相似文献   

Detection and significance of tetracycline residues in eggs     

J Frieser  W Gedek  P Dorn 《DTW. Deutsche tier?rztliche Wochenschrift》1986,93(1):17-20

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Pharmacokinetic and Phase I Evaluation of Carboplatin in Dogs   总被引：1，自引：1，他引：0  

Rodney L. Page DVM  MS    Margaret C. McEntee DVM    Steven L. George PhD    Patrick L. Williams PhD    Greta L. Heidner DVM    Carol A. Novotney DVM    Jim E. Riviere DVM  PhD    Mark W. Dewhirst DVM  PhD  Donald E. Thrall DVM  PhD 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》1993,7(4):235-240

Thirty dogs with spontaneously occurring malignant neoplasms were treated monthly with carboplatin (CBDCA) given as a 30-minute intravenous infusion in a dose escalation study. Twenty-eight dogs were considered evaluable for toxicity. The maximally tolerated dose of CBDCA was conceptually defined as that dose, determined by logistic regression analyses of toxicity data, resulting in a 50% incidence of moderate toxicity (MOD₅₀) or a 5% incidence of severe toxicity (SEV₅). Each designated maximally tolerated dose was calculated for the first course of treatment only and for the first and second courses of treatment combined to estimate cumulative drug toxicity. The MOD₅₀ and SEV₅ for the first treatment course were 340 and 278 mg/M², respectively. MOD₅₀ and SEV₅ values for the first plus second treatment courses were 327 and 231 mg/M², respectively. The nadir of neutrophil and platelet counts occurred approximately 14 days after treatment. The mean neutrophil and platelet values for all dogs experiencing myelosuppression during the first two treatment courses were 1541/μL and 62,600/μL, respectively. Nonparametric pharmacokinetic analysis of plasma CBDCA values suggested that half-life (T_1/2), area-under-the-curve and total body clearance (CL_b) were not dose dependent. Volume of distribution (VD_ss) significantly increased with dose only between 100 and 150 mg/M², not between 150 and 300 mg/M². Dose-independent serum CBDCA pharmacokinetic disposition indicates that detailed investigation of tissue CBDCA distribution would be warranted and may identify novel dosing strategies that could improve the therapeutic index of CBDCA by minimizing toxicity. (Journal of Veterinary Internal Medicine 1993; 7:235–240. Copyright © 1993 by the American College of Veterinary Internal Medicine.)  相似文献   

“无我”的宁静与“有我”的振动——陶渊明与华兹华斯诗歌中“自然”观比较     

成丽芳  李冠杰 《山西农业大学学报(自然科学版)》2001,21(4):358-360

陶渊明和华兹华斯同出于对各自现实政治不满的目的 ,返始归根回到了自然。由于诗人分属于东西方完全不同的文化系统 ,且在各自的文学土壤上滋生、发展 ,因此在自然之中呈现出“无我”与“有我”的明显差异。  相似文献