Potential use of rare earth oxides as tracers of organic matter in grassland          下载免费PDF全文

Mehmet Senbayram  Roland Bol  Liz Dixon  Andrew Fisher  Carly Stevens  John Quinton  David Fangueiro 《植物养料与土壤学杂志》2015,178(2):288-296

Tracing organic matter (OM) in soil is challenging, because runoff and leaching processes are interrelated and have multiple sources. Therefore, multiple tracers with low background concentrations such as rare earth element oxides (REOs) are necessary to delineate the origin of sources of the organic materials in groundwater, rivers or in catchments. The main objective of this study was to examine the potential use of REOs as a tracer in various forms of OM (1) whole slurry, (2) solid, and (3) liquid phase of cattle slurry after mechanical separation. A laboratory experiment was carried out using five REOs (La, Gd, Sm, Pr, and Nd oxides) mixed directly into soil or mixed with various fractions of cattle slurry and then applied to the soil surface. In the additional grassland experiment, Gd oxide was spiked with soil and cattle slurry and then applied to the soil surface. The mineral N in the liquid phase (urine) of the slurry in the grassland experiment was labelled with ¹⁵N urea (16 atom%). In the laboratory experiment, results showed that the five REOs concentration of soil in 0–1 cm soil section after the rainfall simulation was still up to 20 times more than the background values. In 1–2 cm soil section, the concentration of only Gd (two fold higher) and La oxides (50% higher) were significantly higher than the soil background values. Therefore, we hypothesized that Gd and La oxides were associated also with relatively finer organic particles in slurry, thus 1–2 cm soil section were enriched with these oxides. The five REOs concentration below 2 cm soil depth were similar to the background values in all treatments. In line with the laboratory experiment, Gd concentrations in the deeper soil layers (2–4 and 4–8 cm) in the grassland experiment were not significantly affected by any treatment. Both in grassland and laboratory experiment, solid phase of the slurry (dung) was collected from the soil surface after rainfall simulation. Here, about 56% of REOs were measured on the solid phase of the slurry which indicates the strong binding potential of REOs on slurry OM. The present novel study, where REO tagged slurry was uniquely tested to study geochemical cycle of organic fertilizers, clearly highlighted the potential for their use as multiple‐tracers of (animal derived‐) OM in agricultural soils.  相似文献   

Ultrastructure of endometrial stromal cells in the ewe during the estrous cycle and early pregnancy   总被引：1，自引：0，他引：1  

T H Brinsfield  M Fisher  H W Hawk 《Journal of animal science》1974,39(3):565-574

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ULTRASONIC DETERMINATION OF KIDNEY VOLUME IN THE DOG     

Thomas G.  Nyland  DVM  Brett M.  Kantrowitz  DVM  †Paul  Fisher  Harvey J.  Olander  DVM  PHD‡  William J.  Hornof  DVM  MS 《Veterinary radiology & ultrasound》1989,30(4):174-180

Canine kidney measurements were obtained in vivo using ultrasound before and after anesthesia and were compared with direct caliper measurements at laparotomy. Following excision, the kidney dimensions were also measured ultrasonically in a water bath and the results were used to calculate kidney -volume by a modified parallel planimetric method and three variations of a prolate ellipsoid method. The calculated volume was compared with actual kidney volume determined by volume displacement. All methods were found to underestimate actual volume so that a linear correction of ultrasonically calculated volume was required to predict actual volume. The modified parallel planimetric method and a prolate ellipsoid method using height and width determinations cranial and caudal to the renal pelvis were the best models. The prolate ellipsoid model was chosen for subsequent kidney volume calculations because of its simplicity. The noninvasive calculation of kidney volume using ultrasound was sufficiently accurate to be clinically useful, particularly when serially evaluating kidney size changes in the same dog.  相似文献   

ESTIMATION OF PORTAL BLOOD FLOW USING DUPLEX REAL-TIME AND PULSED DOPPLER ULTRASOUND IMAGING IN THE DOG     

Brett M.  Kantrowitz  DVM  Thomas G.  Nyland  DVM  Paul  Fisher  BS 《Veterinary radiology & ultrasound》1989,30(5):222-226

A duplex ultrasound system incorporating a pulsed wave Doppler ultrasound probe with conventional B-mode real-time imaging was used to evaluate portal vein blood flow in eight normal dogs. Adequate visualization of the cranial abdominal vessels was obtained from the right lateral 11th or 12th intercostal space. Doppler spectral analysis showed non-pulsatile flow with a wide range of linear flow velocities across the vessel lumen typical of laminar blood flow. Results for portal vein blood flows were 49.8 ± 13.5 ml/min/kg body weight (mean ± SD) with a range of 37.8 - 76.8 ml/min/kg body weight. These values overestimate portal blood flow by approximately 2 times when compared with published studies using invasive techniques. This overestimation is primarily due to the use of the maximal flow velocity in the blood flow calculations.  相似文献   

Production of delayed ataxia by carbamate acid esters     

Susan W. Fisher  Robert L. Metcalf 《Pesticide biochemistry and physiology》1983,19(3):243-253

Thirty-eight carbamates and thiocarbamates were evaluated for the production of delayed neurotoxicity in the mature White Leghorn hen. Several thiocarbamates including phenyl-N-ethylthiocarbamate and s-2,3-dichloroallyl diisopropylthiocarbamate (diallate) produced symptoms of severe delayed neurotoxicity following repeated oral administration. The results of these experiments do not preclude the possibility that neurotoxic carbamates and organophosphorous compounds may share a common site of action.  相似文献   

Competition effects between fruit trusses of the tomato plant     

K.J. Fisher 《Scientia Horticulturae》1977,7(1):37-42

There were 6 treatments in each of 2 series covering the range from 1–6 fruit trusses per plant. The terminal growing-points were removed 2 leaves above the last inflorescence of each treatment in the “limited-stem” series, and 2 leaves above inflorescence 6 with inflorescences removed as necessary in the “full-stem” series.The yield of trusses 2–5 in the “full-stem” and of truss 2 in the “limited-stem” series was reduced by the presence of subsequent trusses. Similar trends were apparent with trusses 3–5 of the “limited-stem” series. It was suggested that the reduction in yield was due to competition between trusses for assimilates resulting in smaller and/or fewer fruit per truss.Data is presented to suggest that the net assimilation rate in the tomato plant can be reduced due to lack of fruit load and that fruit yield can be limited simultaneously by lack of both source and sink strength.  相似文献   

THE EFFECTS OF INTRA-ARTICULAR ANESTHESIA ON SOFT TISSUE-AND BONE-PHASE SCINTIGRAPHY IN THE HORSE     

Donald R.  Trout  DVM  PhD  William J.  Hornof  DVM  MS  Paul E.  Fisher  BS 《Veterinary radiology & ultrasound》1991,32(5):251-255

Soft tissue- and bone-phase scintigrams were acquired from 4 normal horses before and over a 14-day period after metacarpophalangeal, antebrachiocarpal, tarsocrural and tarsometatarsal joint blocks. Images were evaluated subjectively and quantitatively for increased activity in these regions. The antebrachiocarpal block resulted in obvious focal accumulation of activity on soft tissue-phase scintigrams. This increased activity was greatest 2 to 4 days postanesthesia and persisted up to 14 days postanesthesia. On quantitative analysis of soft tissue-phase images, similar trends were noted after the metacarpophalangeal and tarsocrural blocks, but these increases were relatively mild and were not evident on subjective evaluation of the images. Abnormal soft tissue-phase activity was not associated with the tarsometatarsal block. On bone-phase scintigrams, increased activity was not present following any of these joint blocks.  相似文献   

Improvement of the nutritional quality of Egyptian and Sudanese sorghum grains by the addition of phosphates     

S Ibrahim  C Fisher  H el Alaily  H Soliman  A Anwar 《British poultry science》1988,29(4):721-728

1. Male broilers (0 to 35 d) were given foods with two types of yellow sorghum substituted for maize in isonutrient diets. Sorghum-based foods were also supplemented with extra phosphorus, to provide a total P of about 8 g/kg; the P being from either orthophosphoric acid or food grade dicalcium phosphate. 2. Both sorghums depressed growth and food:gain ratio and increased the incidence of locomotor disorder to about 0.50 (maize control = 0). Sorghum from Sudan, with higher concentrations of both tannin and phytate, caused more severe anti-nutritive effects than sorghum from Egypt. 3. Within the limits of statistical significance the growth depressing effect of sorghum was completely reversed by extra P. With the more toxic Sudanese sorghum this amelioration was numerically less than complete (growth = 0.94, maize control = 1). Locomotor disorders were also virtually, but not completely, eliminated by phosphorus treatment. 4. Treatment of sorghum by dry-mixing with dicalcium phosphate could form the basis of a simple and economic method for extending the use of high-tannin sorghum in poultry foods. The mode of action of the treatment remains to be determined.  相似文献   

The determination of the methionine requirement of laying pullets by a diet dilution technique     

C. Fisher  T. R. Morris 《British poultry science》1970,11(1):67-82

A method for the determination of amino acid requirements of laying hens is described. This involves the dilution of a high protein “ summit” diet with an isocaloric nitrogen‐free mixture. By ensuring that the amino acid to be assayed is first‐limiting in the summit diet, the response to dilution can be interpreted as a response to a single amino acid.

The method is applied to the determination of methionine requirement and it is shown that the response to methionine obtained is virtually independent of the protein level of the diet and is not influenced by direct effects of the dilution mixture.

From the results of the present and other published experiments, the “ available “ methionine required for maximum egg yield of pullets in the early stages of lay is estimated to be 275 mg per bird per day.  相似文献   

Imbalancing of hemic calcium, magnesium, potassium, and sodium by rations and by perenteral injections of ethylenediaminetetraacetate dipotassium salt, potassium chloride, and aldosterone inhibitor. Comparison of cattle held at 2,745 and at 1,372 meters elevation     

J T Blake  D E Bailey  Y S Lu  E J Fisher  R Abaza  J W Call 《American journal of veterinary research》1969,30(2):171-181

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