FA旱地龙对温室辣椒节水效应及产量品质的影响

通过抗早节水剂FA早地龙在辣椒应用中的温室小区试验，分析抗早节水剂对土壤含水率、辣椒产量、辣椒品质的影响。试验设置5个处理区，早地龙喷施浓度分别为250和350倍液，早地龙随水浇灌量为30kg／hm^2和60kg／hm^2。结果表明：早地龙起到了蓄水保墒的作用，随着早地龙喷施浓度增加，土壤含水率提高0．38％～2．12％，土壤含水量变化幅度减小；施用早地龙的辣椒产量明显增加，产量增幅为5．0％～11．7％，同时叶面喷施FA早地龙能明显优化辣椒单果性状，平均单果质量增加7．6％～24．3％；辣椒的Vc和辣椒寨含量均随施用早地龙的浓度增大而增加，果实品质得到显著改善。早地龙对提高土壤含水率及辣椒的品质和产量起着积极作用。     

不同草甸植被类型下土壤腐殖质及有机磷类型探讨

采用熊田法和Bowman-Cole法研究了不同草甸植被类型下的土壤中的腐殖质类型及土壤中的有机磷组分，结果表明，各类土壤总有机质含量变化在7.00%-12.28%之间，游离胡敏酸（fHA）的比率为51.67%-60.10%游离富啡酸（fFA）的比率为80.01%-86.46%；在可提取腐殖质中胡酶酸所占比率为47.99%－56.98%。此外，土壤中腐殖质的相对色度（RF）和E4也都有明显的差异。在土壤的有机磷组分方面，活性有机磷的含量比较低，变化在2.35%-6.01%之间；中等活性有机磷的含量在高海拔寒冷地区较低，变化在32.58%－34.66%之间，在低海拔谷地地区较高，变化在41.97%-52.18％之间；低温有利于中等活性有机磷向中等稳定性有机磷转化；而各类高度稳定性有机磷含量较低，仅高于活性有机磷，均在15％左右。有机碳／有机磷（Co/Po）比值均大于100，有机质中的相对含磷量较低。藏嵩草＋华偏穗草草甸土壤中全磷含量高，其中又以无机磷为主，是该植被类型下土壤的主要特性。     

海口市冬季大气颗粒物PM2.5中多环芳烃源解析

于2014年冬季在海口市两个采样点采集大气PMz5样品,采用超声萃取和GC/MS分析了PM2.5中16种PAHs,探讨了其含量分布特征,并运用因子分析/多元线性回归对PAHs来源进行定性和定量源解析.结果表明,冬季PM2.5中PAHs质量浓度为3.191～15.539ng/m3,两个采样点平均质量浓度为6.771 ng/m3;高温热解和交通污染混合源、生物质燃烧、天然气是PM25中PAHs的3类主要来源,其贡献率分别为74％、10％、16％.     

一株荧蒽降解菌Herbaspirillum chlorophenolicum strain FA1的固定化及其优化

对草螺菌属荧蒽降解菌Herbaspirillum chlorophenolicum strain FA1以不同材料和方法进行固定化,考察固定化后菌株对土水系统中荧蒽的降解性能。结果表明:聚乙烯醇(PVA)-硅藻土载体(硼酸法)固定的菌株对荧蒽的降解效率最高,对荧蒽的25-d降解率达97.74%;硼酸法制备的PVA-硅藻土载体和PVA-活性炭载体对荧蒽的降解效果优于相应冷冻-解冻法制得的载体;硅藻土的添加比活性炭更能够提高固定在PVA复合载体中的菌株FA1对荧蒽的降解率。在此基础上,对PVA-硅藻土载体(硼酸法)进行响应曲面法优化,采用4水平的Box-Behnken设计安排实验,对结果进行拟合和分析,建立二次回归模型并求解,获得最佳固定化条件为:菌浓度9.6%、PVA浓度11.2%、硅藻土浓度4.5%、粒径4 mm。据此优化后,PVA-硅藻土载体(硼酸法)对荧蒽的20-d降解率即达99.46%。     

Evaluation of normal appearing spinal cord by diffusion tensor imaging,fiber tracking,fractional anisotropy,and apparent diffusion coefficient measurement in 13 dogs

Background

Functional magnetic resonance (fMR) imaging offers plenty of new opportunities in the diagnosis of central nervous system diseases. Diffusion tensor imaging (DTI) is a technique sensitive to the random motion of water providing information about tissue architecture. We applied DTI to normal appearing spinal cords of 13 dogs of different breeds and body weights in a 3.0 T magnetic resonance (MR) scanner. The aim was to study fiber tracking (FT) patterns by tractography and the variations of the fractional anisotropy (FA) and the apparent diffusion coefficient (ADC) observed in the spinal cords of dogs with different sizes and at different locations (cervical and thoracolumbar). For that reason we added a DTI sequence to the standard clinical MR protocol. The values of FA and ADC were calculated by means of three regions of interest defined on the cervical or the thoracolumbar spinal cord (ROI 1, 2, and 3).

Results

The shape of the spinal cord fiber tracts was well illustrated following tractography and the exiting nerve roots could be differentiated from the spinal cord fiber tracts. Routine MR scanning times were extended for 8 to 12 min, depending on the size of the field of view (FOV), the slice thickness, and the size of the interslice gaps. In small breed dogs (< 15 kg body weight) the fibers could be tracked over a length of approximately 10 vertebral bodies with scanning times of about 8 min, whereas in large breed dogs (> 25 kg body weight) the traceable fiber length was about 5 vertebral bodies which took 10 to 12 min scanning time. FA and ADC values showed mean values of 0.447 (FA), and 0.560 × 10^-3 mm²/s (ADC), respectively without any differences detected with regard to different dog sizes and spinal cord 45 segments examined.

Conclusion

FT is suitable for the graphical depiction of the canine spinal cord and the exiting nerve roots. The FA and ADC values offer an objective measure for evaluation of the spinal cord fiber integrity in dogs.     

Adipose tissue and muscle fatty acid profiles of steers fed red clover silage with and without flaxseed

The current study examined the effects of inclusion of flaxseed in a red clover silage diet on growth, carcass quality, adipose tissue and muscle fatty acid (FA) profiles of beef steers. Twelve British×Continental crossbred steers (363±26.5 kg) were randomly assigned to two pens and fed diets containing 70% red clover silage, 15% steam rolled barley/vitamin–mineral supplement and either additional 15% steam rolled barley or 15% triple rolled flaxseed (all DM basis) for 215 d. Diet had no effect (P>0.05) on average daily gain or carcass quality atributes. Overall, FA profiles in all tissues followed similar trends when flaxseed was added to the diet but intramuscular fat had the highest proportions of n-3 and n-6 polyunsaturated FA (PUFA) while subcutaneous fat had largest proportions of conjugated linoleic acids (CLA) and perirenal fat had the highest proportions of trans-18:1 isomers, particularly vaccenic acid (VA). Feeding flaxseed increased (P<0.05) percentages of α-linolenic acid (ALA; 1.1–1.6% of total FA), total n-3 PUFA, conjugated linolenic acids, non-conjugated linoleic acids (mostly t11,c15-18:2), and led to unprecedented increases in CLA (mainly rumenic acid, RA; 1.1–2.9%), and trans-18:1 isomers (chiefly VA; 5.9–9.5%) in muscle and adipose tissues. Flaxseed also reduced individual and total n-6 PUFA, cis-monounsaturated FA, branched-chain FA and saturated FA (mainly 16:0) in beef lipids. Overall, feeding flaxseed in a red clover silage diet enhanced the levels of FA with a positive health image (ALA, 2-fold; RA, 3 to 4-fold and VA, 4 to 5-fold) and reduced the levels of less desirable FA (n-6 PUFA; 14:0, 16:0) in muscle and adipose tissues without adverse effects on growth and carcass quality. Differences in tissue FA composition were also noted, and high levels of VA in perirenal fat in particular have potential for use in testing for health effects and development of value added beef and other food products.     

TFA and EPA productivities of Nannochloropsis salina influenced by temperature and nitrate stimuli in turbidostatic controlled experiments

The influence of different nitrate concentrations in combination with three cultivation temperatures on the total fatty acids (TFA) and eicosapentaenoic acid (EPA) content of Nannochloropsis salina was investigated. This was done by virtue of turbidostatic controlled cultures. This control mode enables the cultivation of microalgae under defined conditions and, therefore, the influence of single parameters on the fatty acid synthesis of Nannochloropsis salina can be investigated. Generally, growth rates decreased under low nitrate concentrations. This effect was reinforced when cells were exposed to lower temperatures (from 26 °C down to 17 °C). Considering the cellular TFA concentration, nitrate provoked an increase of TFA under nitrate limitation up to 70% of the biological dry mass (BDM). In contrast to this finding, the EPA content decreased under low nitrate concentrations. Nevertheless, both TFA and EPA contents increased under a low culture temperature (17 °C) compared to moderate temperatures of 21 °C and 26 °C. In terms of biotechnological production, the growth rate has to be taken into account. Therefore, for both TFA and EPA production, a temperature of 17 °C and a nitrate concentration of 1800 μmol L⁻¹ afforded the highest productivities. Temperatures of 21 °C and 26 °C in combination with 1800 μmol L⁻¹ nitrate showed slightly lower TFA and EPA productivities.     

An appraisal of Miscanthus x giganteus cultivation for fly ash revegetation and soil restoration

The objective of this study was to investigate the potential of Miscanthus x giganteus (MxG) for fly ash (FA) revegetation and soil restoration. To evaluate its growth ability on FA, plant development during pot experiments was compared to that obtain in a reference soil. Several physico-chemical parameters (pH, conductivity, dissolved organic carbon, ammonium, nitrite, nitrate, phosphate and potassium contents) and microbiological parameters (enumeration of total, ammonia oxidising and nitrite oxidising culturable bacteria and community diversity analysis) were investigated after plant growth. Plants demonstrated an adaptation to the FA substrate, with an average stem length and biomass production that was half of that observed in the reference soil. Lower chlorophyll contents were measured but the absence of necrosis symptom and hydration rates of aerial parts above 70% suggested physiological adaptation of plants to the FA substrate. Moreover, significant organic carbon inputs could be measured in FA leachates after 17 weeks of laboratory cultivation, which could be related to the establishment of MxG rhizosphere. Besides, the emergence of specific bacterial phylotype could be reported at the FA-root interface. Analysis of FA leachates in planted pots also showed marked decreases of nitrate but increases of nitrite contents, indicating a nitrogen cycle restart. Field trials confirmed the growth potential of MxG directly on FA, without any requirement of additional landfill soil amendment. Finally, we believe that fly ash revegetation with MxG could be an effective strategy for cost effective and long term FA disposal site rehabilitation.     

Influence of the cultivar,environment and management on the grain yield and bread-making quality in winter wheat

The genotype, environment and their interaction play an important role in the grain yielding and grain quality attributes. The main aim of this study was to determine the contributions of the genotype, environment and their interaction to the variation in bread-making traits. The data that were used for the analyses performed in this study were obtained from 3 locations in Poland from post-registration multi-environment trials with winter wheat in 2009 and 2010. The experimental factors were the cultivar (7 cultivars) and the crop management level (low input and high input). In the multi-environment trials, 17 traits were investigated that characterize grain, flour and dough quality. Most of the traits were affected much more strongly by environmental factors (i.e., year and location) than by genotype. The variance components revealed an especially strong effect of the year on the baking score, loaf volume and water absorption, as well a strong effect of the location on dough development and protein content. The obtained results demonstrate that the grain quality as measured by the parameters based on the protein content and quality may be substantially improved by crop management practices, especially by N fertilization level.     

富啡酸对石灰性潮土中磷吸附-解吸及其对锌次级吸附-解吸的影响

通过吸附和解吸试验,研究了富啡酸(Fulvic acid,FA)对石灰性潮土中磷吸附-解吸的影响,并进行了吸附富啡酸和磷后对锌次级吸附-解吸的影响.结果表明:同时吸附不同磷和富啡酸后,土壤对磷的吸附量随磷初始浓度的增加而增加,而随富啡酸吸附初始浓度的增加而降低;石灰性潮土磷等温吸附曲线用Langumir方程式描述时,土壤对磷的吸附反应常数K、最大吸附量Xm、最大缓冲容量K×Xm均随富啡酸初始浓度的增加而降低;KNO3、KOH、HCl对吸附磷的解吸量所占比例及磷的总解吸量均随富啡酸浓度的增加而增加.土壤对Zn2+的吸附率随磷和富啡酸吸附初始浓度的增加而降低;而其解吸率随磷和富啡酸吸附浓度的增加而增加,说明磷和富啡酸减少了土壤对Zn2+的吸附,且增加了其在土壤中的解吸量.所以,石灰性潮土中富啡酸提高了土壤中磷的有效性,而且磷和富啡酸提高石灰性土壤中锌的有效性.