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1.
Utilizing a DUALEM‐421 and inversion modelling to map baseline soil salinity along toposequences in the Hunter Valley Wine district
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In the oldest commercial wine district of Australia, the Hunter Valley, there is the threat of soil salinization because marine sediments underlie the area. To understand the risk requires information about the spatial distribution of soil properties. Electromagnetic (EM) induction instruments have been used to identify and map the spatial variation of average soil salinity to a certain depth. However, soils vary with depth dependent on soil forming factors. We collected data from a single‐frequency and multiple‐coil DUALEM‐421 along a toposequence. We inverted this data using EM4Soil software and evaluated the resultant 2‐dimensional model of true electrical conductivity (σ – mS/m) with depth against electrical conductivity of saturated soil pastes (ECp – dS/m). Using a fitted linear regression (LR) model calibration approach and by varying the forward model (cumulative function‐CF and full solution‐FS), inversion algorithm (S1 and S2), damping factor (λ) and number of arrays, we determined a suitable electromagnetic conductivity image (EMCI), which was optimal (R2 = 0.82) when using the full solution, S2, λ = 3.6 and all six coil arrays. We conducted an uncertainty analysis of the LR model used to estimate the electrical conductivity of the saturated soil‐paste extract (ECe – dS/m). Our interpretation based on estimates of ECe suggests the approach can identify differences in salinity, how these vary with parent material and how topography influences salt distribution. The results provide information leading to insights into how soil forming factors and agricultural practices influence salinity down a toposequence and how this can guide soil management practices. 相似文献
2.
Romi Novriadi Elizabeth Spangler D. Allen Davis 《Journal of the World Aquaculture Society》2019,50(2):433-447
The present study was designed to investigate the effects of diets containing advanced soy products (enzyme‐treated soy and fermented soy) or corn protein concentrate (CPC) in combination with porcine meal (PM) to completely replace poultry byproduct meal (PBM) on growth performance, body composition, and distal intestine histology of Florida pompano, Trachinotus carolinus. Four experimental diets were formulated to be isonitrogenous and isolipidic, to contain 400 g/kg crude protein and 80 g/kg lipid. A reference diet (PBM diet [PBMD]) contained 150 g/kg PBM and 495 g/kg soybean meal (SBM), and three test diets were formulated replacing PBM with 15 g/kg of CPC (CPC diet [CPCD]) or replacing all SBM and PBM with 535 g/kg fermented soy (fermented soybean meal diet [FSBMD]) or 451.3 g/kg enzyme‐treated soy (enzyme‐treated soybean meal diet [ESBMD]). All three test diets were supplemented with 38 g/kg of PM. Diets were fed based on a percentage of bodyweight adjusted after sampling the fish every 2 weeks to triplicate groups of Florida pompano juveniles (mean weight 8.06 ± 0.22 g). After 8 weeks of feeding, fish fed CPCD and ESBMD performed equally well in terms of final body weight, thermal growth coefficient, and percentage weight gain in comparison to fish fed PBMD. In all cases, feeding FSBMD resulted in poor feed conversion and lower feed intake compared to other treatments. Protein retention efficiency, whole‐body proximate composition, phosphorus, sulfur, potassium, magnesium, calcium, sodium, and zinc contents were not significantly influenced by the dietary treatments. The results obtained in the present histological study showed no significant differences in the thickness of serous layer, muscular layer, and submucosal layer of the intestine among treatments. Fish fed CPCD showed a significant widening of the lamina propria with an increase of cellular infiltration and higher presence of goblet cells compared to other dietary treatment. Based on these results, 451 g/kg ESBM or combination of 150 g/kg of CPC and 495 g/kg SBM supplemented with 38 g/kg PM can be utilized to develop a practical diet for juvenile Florida pompano without impacting growth, nutritive parameters, and several distal intestine health parameters. 相似文献
3.
Fabio Soller Luke A. Roy D. Allen Davis 《Journal of the World Aquaculture Society》2019,50(1):186-203
Stearine fish oil (SFO) and palm oil (PO) have emerged as promising alternatives for the replacement of fish oil (FO) in aquafeeds. This study evaluated the replacement of FO with alternative oils in practical diets for Litopenaeus vannamei. In a clear brackish water study (14.1 g/L) utilizing shrimp (0.29 ± 0.02 g, initial weight), FO was replaced by SFO at inclusion ratios of 100:0, 75:25, 50:50, 25:75, and 0:100 (FO:SFO) and PO as 90% of FO. After 55 days, no significant differences (p < 0.05) in final weight, growth, or survival of shrimp were observed. A second trial (8 weeks) in low‐salinity water (2.1 g/L) with shrimp (0.92 ± 0.02 g, initial weight) evaluated diets with 100% FO, 100% SFO, 90% PO, 90% soybean oil (SO), or 90% flaxseed oil (FXO) as a replacement for FO and four commercially produced diets with 2% of FO, SO, PO, or FXO. One treatment received half rations of the commercial FO diet, and one treatment was based entirely on natural productivity. Results show that the fatty acid profiles of the tail muscle conformed to the lipids of the feed, and highly unsaturated fatty acids (HUFAs) were preserved. Following 8 weeks of culture, there were no significant differences in production performance. 相似文献
4.
《Soil Use and Management》2018,34(1):1-8
Cost‐effective strategies for using chemically amended organic fertilizers need to be developed to minimize nutrient losses in surface and groundwater. Coupling specific soil physical and chemical characteristics with amendment type could increase their effectiveness. This study investigated how water‐extractable phosphorus (P) was affected by chemical amendments added to pig slurry and how this effect varied with soil properties. A 3‐month incubation study was conducted on 18 different mineral soils, stored at 10 °C and 75% humidity and treated with unamended and amended slurry which was incorporated at a rate equivalent to 19 kg total P (TP )/ha. The amendments examined were commercial‐grade liquid alum, applied at a rate of 0.88:1 [Al:TP ], and commercial‐grade liquid poly‐aluminium chloride (PAC ), applied at a rate of 0.72:1 [Al:TP ]. These amendments were previously identified by the authors as being effective in reducing incidental losses of P. The efficacy of the amendments varied with the soil test P, the degree of P saturation (DPS ) and the Mehlich aluminium, iron and calcium, but not soil texture. Chemical amendments were most effective in soils with DPS over approximately 20%. Due to their high cost, the incorporation of amendments into existing management practices can only be justified as part of a holistic management plan where soils have high DPS . 相似文献
5.
6.
家用冰箱存在着不同程度的细菌污染,必需对冰箱进行定期或不定期的消毒。经用载体法和平皿法研究发现,用紫外线对冰箱进行消毒是可行的,其对大肠杆菌、金黄色葡萄球菌和枯草杆菌黑色变种芽胞有较强的杀灭作用,而且不会引起冰箱内温度升高。同时还可产生少量Q,除去冰箱内异味,因此具有杀菌、抑菌、除臭保鲜的作用。 相似文献
7.
PULMONARY MINERALIZATION IN FOUR DOGS WITH CUSHING'S SYNDROME 总被引:1,自引:0,他引:1
Clifford R. Berry DVM Norman Ackerman DVM Kevin Monce DVM 《Veterinary radiology & ultrasound》1994,35(1):10-16
The clinical and imaging features of four dogs with Cushing's syndrome and pulmonary mineralization are reviewed. Three dogs presented with a primary complaint of respiratory distress/dyspnea. Three dogs had pituitary dependent Cushing's syndrome, while the remaining one dog had iatrogenic Cushing's syndrome. Each dog had clinical features typical for Cushing's syndrome. Two of the dogs were euthanized due to progressive hypoxemia. In each dog, the serum calcium, phosphorous, blood urea nitrogen and creatinine were normal.
A generalized increase in unstructured interstitial pulmonary opacity with diffuse mineralization was noted on thoracic radiographs of all dogs. In one dog, an ill-defined nodular interstitial pattern of mineralization was present. Delayed bone phase scintigraphy using99m Technetium methylene diphosphonate documented generalized pulmonary uptake in two dogs. 99m Technetium labeled microaggregated albumin lung perfusion scans were normal in these two dogs. 99m Tc-MDP scintigraphy can provide useful information in diagnosing pulmonary mineralization in Cushingoid dogs. 相似文献
A generalized increase in unstructured interstitial pulmonary opacity with diffuse mineralization was noted on thoracic radiographs of all dogs. In one dog, an ill-defined nodular interstitial pattern of mineralization was present. Delayed bone phase scintigraphy using
8.
The absence or presence of metastases on thoracic radiographs in 55 female dogs with mammary gland tumors was assessed by comparing the results of a single radiographic examination, using dorsoventral and left lateral views, with clinical and histologic follow-up data. Radiographic abnormalities found in dogs with thoracic metastases were classified as well-defined pulmonary nodules, ill-defined pulmonary nodules, and involvement of pleural effusion. No obvious difference in the effect on the right or left lung lobes was found. The sensitivity, specificity and accuracy for the detection of thoracic metastases were 65%, 97%, and 87%, respectively. 相似文献
9.
Rapid Screening for Aluminum Tolerance in Cereals by Use of the Chlorophyll Fluorescence Test 总被引:1,自引:0,他引:1
The effects of aluminum on the photosynthetic apparatus were examined in cereals grown in nutrient solutions (pH 4.5) at two Al levels (0 and 148 μM). The chlorophyll fluorescence kinetics results confirmed that the soft wheat ‘BHG’ cultivar has the potential for growth on acid soils while triticale cultivars ‘Niovi’ and ‘Dada’ appeared to be relatively tolerant. The percentage decrease in Fv/Fm of the less tolerant cultivars after Al-treatment indicated a decrease in the efficiency of the primary photochemistry of PS II, while the decrease in the ratio FV/Fosuggested that exposure of the cultivars ‘Dio’ and ‘Appulo E’ to aluminum caused injury to the thylakoid structure. The percentage fluctuations of the ratio Fv/Fmwere shown to correlate very closely with the assessment of injury as evaluated by the relative top fresh weight. Measurements of chlorophyll fluorescence in vivo could be used to monitor injury caused by “Al-stress”, and thus they may serve as a rapid screening test for Al tolerance. 相似文献
10.
从驾驶员心理学和生理学角度探讨了汽车夜间会车时眩目的机理.由于传统的前照灯配光设计停留在二维的层面上,设计周期长,且配光效果差,很难达到防眩目的要求.本文通过Reflector CAD软件反求出了符合ECE法规配光要求的自由曲面前照灯反射镜的三维模型,该模型可以直接用于数控程序的编制,减小了前照灯的设计成本和设计周期,利用TracePro软件对模型进行近光配光的仿真实验,通过光线追踪的方法避免了实际配光实验时调整反射镜配光所需的反复制造过程,同时又保证了前照灯防眩目的效果。 相似文献