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51.
通过对比中国黄土高原地区与俄罗斯欧洲部分东南部地区森林生长状况,分析了人工林系统的异同点,探索了可持续的人工造林策略.认为必须通过重新分配大气降水而补充林下土壤水分来改善人工林的生长状况和缓解土壤干化,在中国黄土高原地区可通过调节暴雨径流来实现,而在俄罗斯可通过集中降雪和调节融雪径流实现.  相似文献   
52.
The objective of this study is to evaluating the Brazilian biodiversity through physicochemical characterization and determination of antioxidant potential of three species from the Myrtaceae family, namely yellow guava (Psidium cattleyanum Sabine), guabiroba (Campomanesia xanthocarpa O. Berg), and uvaia ( Eugenia pyriformis Cambess). Guabiroba had the greater quantity of phenolic compounds (9033 mg chlorogenic acid/100 g) and vitamin C (30.58 mg/g) and showed the best TSS/TTA (total soluble solid/total titratable acid) ratio (45.12). For the ABTS (2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic) method, the guabiroba (507.49 μM Trolox/g) presented the highest antioxidant potential; however, in the DPPH (2,2-diphenyl-1-picrylhydrazyl) method, uvaia (170.26 g/g DPPH) and guabiroba (161.29 g/g DPPH) were not statistically different. The uvaia outranked the other fruits with respect to its high carotenoid (909.33 μg/g) and vitamin A (37.83 μg/g) contents, and the yellow guava, although showing a lower bioactive compound content and antioxidant activity, nevertheless presented much higher values than many traditionally consumed fruits.  相似文献   
53.
Hydropower plants on the lower river Sava, Slovenia, were developed without sealing the underground upstream. As a consequence, without the countermeasures of elevating and recultivating, the agricultural land on the river banks would be inundated because of the water‐table increase of the river. To remedy this, the fields were elevated and recultivated. The goal of this study was to assess soil quality and production potential after land raising and recultivation and to answer the question whether it is possible to recover soil quality and crop yield after large‐scale mass manipulation, such as land raising. After recultivation and after the second year of land reuse for the two cultures grass–clover mixture and corn on two sites, Middle Pijavsko and Lower Pijavsko, soil physical and chemical characteristics and crop yields were evaluated. Mixing of topsoil with the second horizon during removal and during backfill with filling material resulted in uneven soil fertility, plant growth and decreased yield. Driving on the refilled second layer with heavy machinery caused soil compaction in the Middle Pijavsko in spite of favourable soil texture (loam, 38·7% sand). On the areas with very high sand content (over 55%) and low clay content (10%), soil compaction was not as severe or persistent. Recultivation measures restored the agricultural land almost to the production potential prior to powerplant construction. Immediate intensive land use (corn) showed less favourable effect on soil characteristics. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   
54.

Purpose

The objective of this research is to find out the spatial distribution of different traffic-related contaminants in urban topsoils across a highway (125,000 vehicles per day) in the city of Moscow, Russia.

Materials and methods

The topsoils (0–3 cm depth) were sampled 1, 6, 10, 18, and 50 m perpendicular to the roadbed in three replicates 10 m apart. We analyzed total petroleum hydrocarbons (TPH), polycyclic aromatic hydrocarbons (PAH), heavy metals in total and phyto-available forms (HM; Cu, Zn, and Pb), and deicing salts (DS; Cl?). The TPH were extracted with carbon tetrachloride and detected by spectrometry and PAH were extracted with methylene chloride, separated by high-performance liquid chromatography, and determined by fluorescence detector. Total HM were extracted by microwave acid digestion with aqua regia and phyto-available forms were extracted by NH4OAc and determined by inductively coupled plasma mass spectrometry. The DS were analyzed using an ion liquid chromatograph with a conductometric detector.

Results and discussion

Heavy soil pollution was found within 1–6 m of the road. The TPH, B[a]P, and phyto-available HM concentrations exceeded permissible levels for Russia, while total HM and DS did not. The contaminant contents sharply decreased 10 m from the road. Within 10–50 m, they reached background levels, while PAH levels were elevated. We attribute this to the greater age of soils at 10–50 m than 1–6 m from the road. The different contaminant distribution patterns are attributed to their different transportation pathways: TPH, DS, and HM generally reach soils through road spray, splashes, melting snow moved from the road surface to roadsides, and aerosol sedimentation, whereas PAH are mainly transported as airborne particles and are thus able to reach more distant locations.

Conclusions

Traffic-related soil pollution creates ecotoxicological and human-health risks. Distribution patterns vary by type of soil contaminant. The influence of the road on soil contamination was greatest within 10 m from the roadbed for TPH, HM, and DS and within 50 m for PAH. The increased PAH concentration levels with increased distance from the road highlights the importance of PAH monitoring in roadside soils.
  相似文献   
55.
Protein fractions from transgenic Bt and non-transgenic maize varieties, extracted by the Osborne solvent fraction procedure, were characterized for the first time by perfusion and monolithic RP-HPLC in very short analysis times. Albumins and globulins from different transgenic Bt maizes as well as from their non-transgenic isogenic varieties were eluted in four peaks using perfusion RP-HPLC, whereas prolamins and glutelins were separated in seven peaks. Monolithic RP-HPLC enabled the separation of maize proteins in a large number of peaks showing 6 and 10 main peaks for albumins and globulins, respectively. Prolamins migrated at retention times higher than 5 min as seven peaks, whereas glutelins were separated in three main peaks appearing at retention times higher than 6.0 min. Moreover, chromatograms of the whole protein extracts showed 8 and 11 components for perfusion and monolithic RP-HPLC, respectively. A comparison of the chromatograms of the whole protein extracts relative to transgenic and non-transgenic varieties evidenced quantitative differences on the percentages of area, mainly for peaks 2 and 3 by perfusion RP-HPLC and for peaks 3 and 7 by monolithic RP-HPLC. A discriminant analysis based on these proteic profiles was carried out to classify and predict transgenic Bt maize lines, achieving 100% correct classification using perfusion RP-HPLC.  相似文献   
56.
This study assesses the impact of equine infectious anaemia virus (EIAV) infection on the oxidant/antioxidant equilibrium of horses. Blood samples from 96 Romanian horses aged 1-25 years, were divided into different groups according to their EIAV-infection status, age, and time post-seroconversion. The effect of infection on oxidative stress was estimated by measuring enzymatic antioxidants (superoxide dismutase [SOD], glutathione peroxidase [GPx] and catalase), non-enzymatic antioxidants (uric acid and carotenoids), and lipid peroxidation (malondialdehyde [MDA]). Infection modified the oxidant/antioxidant equilibrium in the horses, influencing GPx and uric acid levels (P<0.05). Time post-seroconversion also contributed to oxidative stress imbalance, exhibiting a significant influence on both SOD and MDA concentrations in the blood (P<0.05). Animal age did not have a significant influence on oxidative stress. Recently infected horses (<1 year following seroconversion), and horses >5 years old, represented the most vulnerable category in terms of oxidative stress, followed by recently infected animals <5 years old. The results of this study are novel in implicating EIAV infection in the development of oxidative stress in horses.  相似文献   
57.
To clarify whether a particular group of soils of Archangelsk region (European N Russia) with humus‐rich topsoils exceeding the plowing zone supports an anthropogenic formation, four exemplary profiles were investigated. The investigation sites are characterized by distinct elevated surfaces, and the soils show thick toplayers of up to 60 cm with enrichment of soil organic matter and artifacts like brick, charcoal, and peat fragments, all indicating an anthropogenic origin. Increased phytolith amounts and high P contents of up to 800 mg kg–1 citric acid–soluble P and up to 1,400 mg kg–1 total P in the top horizons support an anthropogenic influence. These properties are very similar to the Plagganthrepts of NW Europe. The same is true regarding the main management aims: increasing soil fertility and overcoming the need of bedding materials. Having the required depths of the anthropogenic topsoil, the properties of the soils of the Archangelsk region allow a classification as Agrozems (Russian classification), Plaggenesche (German classification), and Plagganthrepts (US taxonomy). Since the high base saturation of the topsoil excludes a designation as plaggic horizon, the topsoil has to be considered as terric horizon, which leads to a classification as Terric Anthrosol according to WRB.  相似文献   
58.
Oxidation of bovine serum albumin, casein, and lactalbumin and the effect of different procyanidins, anthocyanins, and their aglycons (10 and 20 microM) on lactalbumin oxidation were investigated in a liposome system. Samples were incubated in the dark at 37 degrees C with copper, and the extent of oxidation was measured by determining the loss of tryptophan fluorescence and the formation of protein carbonyls, conjugated diene hydroperoxides, and hexanal. The correlation between different protein and lipid oxidation measurements was good and statistically significant. Casein was the most stable protein in the liposome model, and it was also the best inhibitor of liposome oxidation. All tested anthocyanins and other phenolic compounds inhibited both lipid and protein oxidation. There were no systematic differences with anthocyanins and their aglycons in relation to the concentrations used or glycosylation with either glucose or rutinose. Procyanidins B1 and B2 and ellagic acid were potentially better antioxidants than anthocyanins due to their several hydroxyl groups as measured by both protein and lipid oxidation. In conclusion, oxidative deterioration of liposomes due to protein-lipid interaction is inhibited by anthocyanins, procyanidins, and ellagitannin present, for example, in berries.  相似文献   
59.
There are clear differences in the normal radiographic appearance of the abdominal organs between a left lateral vs. a right lateral view. While a few veterinary academic institutions have transitioned to a three‐view abdominal radiographic study protocol, obtaining only two views of the canine abdomen remains the current standard in veterinary medicine. In this combined retrospective and prospective, case‐controlled study, 48 canine patients presenting with signs of acute abdomen were recruited. Four board‐certified veterinary radiologists and four general practice veterinarians with greater than 3 years of experience in small animal practice were asked to determine if 10 predetermined findings were present within the set of images and if surgery was recommended based on those findings. Image readers were unaware of the clinical history. Three‐view studies did not yield statistically significantly greater accuracy than two‐view studies when evaluating all readers together. No statistically significant associations between the availability of the third view and increased accuracy or confidence were found in evaluations of general practitioners specifically. Evaluation of three‐view radiographic examination, as compared to two‐view examination, did not have perceived or statistically significantly increased diagnostic utility. Based on our findings, there is no statistically increased utility to justify a standard three‐view abdominal radiographic examination over a two‐view study for canines presenting with signs of acute abdomen.  相似文献   
60.
Control of lettuce downy mildew (Bremia lactucae) with phenylamide fungicides has failed in some intensive lettuce-producing areas in Northern Italy since Spring 1993. Before then, these chemicals and particularly metalaxyl, provided the best disease control. The sensitivity of Bremia lactucae isolates collected in such areas to metalaxyl was evaluated in the laboratory. These strains grew and sporulated profusely on lettuce seedlings treated with 100 and 200 ppm of metalaxyl, whereas sensitive control strains were completely inhibited when treated with fungicide concentrations ranging from 0.5–1 ppm. Thus in Italy occurrence of resistance to phenylamide fungicides in Bremia lactucae has also been demonstrated, as in almost all the countries where these chemicals were previously authorised. Subsequently, a demonstration of occurrence of resistance was made and the virulence pattern of several strains (resistant and sensitive to metalaxyl) was characterised using differential NL series containing the 13 DM resistant genes or R factors. The results suggest the occurrence of a new pathotype in Italy different from all the 16 NL Bremia lactucae races studied.  相似文献   
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