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91.
Sandy‐textured Mediterranean soils are invariably depleted in organic matter and supply only small amounts of N to crops. To compensate for these deficiencies, we tested the N supply from six organic wastes applied to a Cambic Arenosol in pots growing ryegrass. The results showed that the behaviour of the wastes in supplying N to a ryegrass crop grown in this soil can be predicted by observing their performance in laboratory aerobic incubations. The N made available during these incubations fitted well to a one‐pool kinetic model. 相似文献
92.
N. Fenner D. J. Dowrick M. A. Lock C. R. Rafarel & C. Freeman 《Soil Use and Management》2006,22(3):267-273
The temperature dependence of chemical reaction rates and microbial metabolism mean that temperature is a key factor regulating soil trace gas emissions and hydrochemistry. Here we evaluated a novel approach for studying the thermal response of soils, by examining the effects of temperature on gas emissions and hydrochemistry in (a) peat and (b) soil from a Sitka spruce plantation. A thermal gradient was applied along an aluminium bar, allowing soil to be incubated contemporaneously from 2 to 18 °C. The approach demonstrated clear differences in the biogeochemical responses of the two soil types to warming. The peat showed no significant emission of CH4 at temperatures below 6 °C, while above 6 °C, a marked increase in the rate of release was apparent up to 15 °C (Q10 = 2.5) with emissions being similar between 15 and 18 °C. Conversely, CH4 emissions from the forest soil did not respond to warming. Nitrate availability in the peat decreased by 90% between 2 and 18 °C (P < 0.01), whereas concentrations in the forest soil did not respond. Sulphate availability in the peat decreased significantly with warming (60%, P < 0.01), while the forest soil showed the opposite response (a 30% increase, P < 0.01). Conventionally, thermal responses are studied by incubating individual soil samples at different temperatures, involving lengthy preparation and facilities to incubate samples at different temperatures simultaneously. Data collected on a given thermal response is usually limited and thus interpolated or extrapolated. The thermal gradient method overcomes these problems, is simple and flexible, and can be adapted for a wide range of sample types (not confined to soil). Such apparatus may prove useful in the optimization of management practices to mitigate the effects of climate change, as thermal responses will differ depending on land use and soil type. 相似文献
93.
Conrado M. Gempesaw J. Richard Bacon Ferdinand F. Wirth 《Journal of the World Aquaculture Society》1992,23(1):38-48
The objective of this study was to evaluate the relationship of pond size and hybrid striped bass growout profitability as an alternative source of farm income in the Mid-Atlantic region. A dynamic, whole farm, Montdarlo capital budgeting simulation model (AQUASIM) and stochastic dominance with respect to a function technique were used to analyze the economics of hybrid striped bass growout from phase II to market production stage for eight farms categorized by pond sizes. Three scenarios are assumed to examine the effects of pond-size dependent changes in feed conversion efficiency and fingerling survival rates on discounted after-tax net present values and probabilities of economic survival and success. Optimal pond sizes were found to be in the 2.5 acre to 10 acre range. 相似文献
94.
S Makimura M Sawaki 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》1992,54(1):63-67
Zymosan-induced and luminol-aided chemiluminescence (CL) of whole blood from beagle dogs was estimated for the function of polymorphonuclear leucocytes (PMNs). Whole blood (0.1 ml) was examined directly and results were obtained within 20 min. A phagocytic function of PMNs can be estimated from the peak CL counts and the number of PMNs in a specimen, and the opsonic activity can also be estimated by the peak time showing peak CL after the addition of non-opsonized zymosan. The optimal temperatures to keep diluted whole blood for the CL measurement was around 13 degrees C. Thus, this method offers information concerning the functions of phagocytic cells in whole blood. 相似文献
95.
G Plassiart J F Guelfi J P Ganiere B Wang G Andre-Fontaine M Wyers 《Zentralblatt für Veterin?rmedizin. Reihe B. Journal of veterinary medicine. Series B》1992,39(6):443-453
Twenty rabbits were inoculated with a suspension of Viral Hemorrhagic Disease virus. Hemostatic functions were assessed every sixth hour from 6 to 60 hours post-inoculation. Tissue samples obtained at the same intervals allowed the study of the development of lesions throughout the experiment. Biological signs of Disseminated Intravascular Coagulation (DIC) were detected on and after 30 h post-inoculation and consisted of prolonged One Stage Prothrombin Time and Activated Partial Thrombin Time, the decrease of factors V, VII, and X and high levels of soluble fibrin monomer complexes and D-dimers. A reduction of thrombocyte numbers, heterophils and lymphocytes was associated. The close association of DIC and necrotizing hepatitis lesions suggested the hepatic lesions to be the most important DIC triggering factor. Other mechanisms are discussed. 相似文献
96.
A rapid and low cost procedure, the carbon immunoassay (CIA) test, was evaluated for the diagnosis of Toxoplasma gondii infections. Using a closely related parasite (Besnoitia jellisoni) as antigen, and homologous or heterologous immune sera, it was demonstrated by light and electron microscopy that CIA is a very reliable and specific test. As it is neither expensive nor time-consuming, it can be recommended for general and routine laboratory use. 相似文献
97.
R M Bednarski 《Veterinary Clinics of North America: Small Animal Practice》1992,22(2):273-275
Opioids produce unpredictable anesthesia that is associated with poor muscle relaxation, prolonged onset, and relatively difficult intubation. They often induce bradycardia, which must be countered with atropine or glycopyrrolate, and hypoventilation, which requires ventilatory support. Return to consciousness is often delayed, making postoperative assessment of the patient's condition difficult. Finally opioid induction is relatively expensive compared with other anesthetic induction regimens. 相似文献
98.
W. E. HAWKINS J. W. FOURNIE R. M. OVERSTREET W. W. WALKER 《Journal of fish diseases》1988,11(3):259-266
Abstract. Three cases of skeletal muscle neoplasms occurring in two small fish species used in carcinogen tests are reported. The cases illustrated a wide range of histologic patterns, and consisted of a well-differentiated juvenile type, a well-differentiated pleomorphic type and a poorly differentiated pleomorphic type. A rhabdomyosarcoma with juvenile type features developed in the Japanese medaka, Oryzias latipes , exposed to 0·5 ml/1 of the solvent dimethylformamide. A pleomorphic type rhabdomyosarcoma occurred in one medaka and in one guppy, Poecilia reticulata , exposed to the carcinogen methylazoxymethanol acetate. These cases indicate the potential for skeletal muscle cells in medaka and guppy to become neoplastic but, because the tumours occurred at a low frequency, there may not necessarily be a chemical aetiology. 相似文献
99.
Tooth root and root trunk surface area measurements were taken from 20 first mandibular molar (M1) teeth obtained randomly from canine cadaver specimens. The mean root surface area for all teeth was 497.1 +/- 116.2 mm2. The cumulative surface areas of the mesial (MR) and distal (DR) roots were 251.4 +/- 70.2 mm2 and 211.7 +/- 51.9 mm2, respectively. The root trunk surface area was 34.0 +/- 21.4 mm2. Surface area measurements for individual roots and the root trunk were significantly different. Cumulative individual root surface area (MR + DR) was 93.2% of total root surface area. The MR surface area contributed most to total root surface area (50.6%) and cumulative individual root surface area (54.3%). The mean distance from the beginning of the root trunk to the furcation was 2.1 mm. On the basis of the linear variation of the percentage of root surface area of the M1, 44.6% of the total root surface area was 3 to 7 mm apical to the most coronal aspect of the cementoenamel junction. The MR was heart-shaped, compared with the more cylindrical shape of the DR. 相似文献
100.
D A Ward K S Latimer R M Askren 《Journal of the American Veterinary Medical Association》1992,200(10):1503-1506
Squamous cell carcinoma is an uncommon tumor of the cornea in dogs. A 12-year-old Shih Tzu with a history of chronic keratoconjunctivitis sicca was diagnosed as having squamous cell carcinoma of the corneoscleral limbus. The lesion was treated by surgical resection and cryotherapy. One year after surgery, multiple tumors, apparently unrelated to the first tumor, appeared on the same cornea. Keratoconjunctivitis sicca may have predisposed the dog to corneal squamous cell carcinoma development. 相似文献