元谋干热河谷植物功能性状组合的海拔梯度响应

植物功能性状能够显示对环境变化的响应,不同的适应对策呈现出不同的功能性状组合。干热河谷地区水分是最主要的限制性环境因子,之前的大部分研究都是集中关注于干热河谷局部地段,对于从垂直海拔上来研究不同植物在环境梯度下的变化的研究较少。干热河谷地区由于梵风效应,水分胁迫沿海拔梯度发生变化,一般表现为随海拔高度升高,气温降低,湿度和降水量增加,而蒸发量减小,辐射增强。以云南元谋干热河谷4个海拔梯度（1491.33、1730.20、1850.00、1925.57 m）中的植物为研究对象,选取叶片干物质含量（LDMC）、叶面积（LA）、比叶面积（SLA）、叶片厚度（LT）和叶密度（LD）5个功能性状,研究它们的相互关系,比较了海拔间的差异。结果表明：1）5个功能性状在不同海拔间均呈现出一定差异,变异系数由高到低为LD>LA>SLA>LT>LDMC（分别是101%、64%、56%、41%和19%）;方差分析结果也表明,5个功能性状在不同海拔之间差异显著（F=56.218,P<0.01;F=7.829,P<0.01;F=11.21,P<0.01;F=7.429,P<0.01;F=19.213,P<0.01）,尤其是在最低（1491.33 mm）和最高（1927.57 mm）海拔之间,各性状均具有极显著的差异;2）性状之间存在组合关系, LD与其他性状间相关性最为明显,除LDMC以外,LD与LA、SLA、LT均呈现出极显著负相关关系;LDMC与LA和LT呈极显著负相关;SLA与LA和LT呈正相关,而与LDMC显著负相关;LT与SLA显著正相关,与LA之间相关性不显著;3）在不同的海拔梯度之间,性状组合存在非同步变化现象。研究显示,元谋干热河谷地区,植物对水分环境的海拔梯度变化产生功能性状组合的响应,低海拔和高海拔物种对所处环境的适应策略不同,使得植物在海拔梯度上出现叶片功能性状组合的分化和差异。     

First Trimester Prenatal Diagnosis of Metabolic Diseases: A survey in countries from the European Community

This paper presents the collected data concerning First Trimester Prenatal Diagnosis of Metabolic Diseases performed in different countries of the European Community by enzymatic methods using chorionic villi. In all, 258 diagnoses were made for 38 different metabolic diseases and 56 (22 per cent) affected fetuses have been detected. Several difficulties were encountered with regard to chorionic villus material or enzyme expression in this tissue. We stress the conditions necessary for avoiding errors in diagnosis.     

The role of conjugation in the gene-individual-population relationships in increasing eco-exergy

The genotypic and phenotypic processes were incorporated into one system in the gene-individual-population relationships under the framework of Individual based models (IBMs). The gene types addressing different degrees of metabolic efficiency and toxin susceptibility were provided as attributes in the individuals. Subsequently ecological processes such as food competition and movement were allowed concurrently on the 2-D space to determine the suitable species adapted to the system. The integrative gene-individual-population model accordingly responded to gene exchanges between the neighboring individuals through conjugation. At a substantially low level of gene exchange, system heterogeneity increased to produce high levels of eco-exergy, being presented by species diversity and total population size in the system. The issues related to genetic and ecological effects in the integrative gene-individual-population relationships were further discussed.     

湖南省绥宁县黄桑坪自然保护区珍稀濒危植物长苞铁杉自然种群年龄结构及生态对策

通过对湖南省绥宁县黄桑坪自然保护区长苞铁杉的种群结构、特定时间生命表、生殖价分析、分布数量与环境因子的关系进行分析.结果表明:(1)种群结构数量具有"中间大,两头小"的特点,为衰退型种群,虽然种群有一定的幼龄个体,但死亡率高,35 a内长苞铁杉的年龄结构模型为:Age(a)=0.002 765(DBH)3-0.128 756(DBH)2+4.120 978(DBH)+13.439 846(R=0.991 2,F=2 654.48);(2)长苞铁杉种群既有r对策特征,又有K对策特征,该种群处于r对策→K对策的过渡阶段;(3)长苞铁杉的累积剩余生殖价(SRRV)和整个生活史的总生殖价(TRV)呈现出逐渐递减的趋势,而生殖投资策略(OREx)在整个生长过程中具有"n"型变化特征,说明长苞铁杉种群有实现生殖与恢复的可能,但能力有限.     

基于模糊集值理论的城市应急避难所应急适应能力评价方法研究

以层次分析法为基础,根据城市应急避难所的功能特点,从规划设计、内部硬件设施、外部软件环境3个方面出发,选定18个评价指标,构造了城市应急避难所应急适应能力影响因素的层次结构,建立了综合评价模型.基于模糊集值统计理论,求出了各指标的合成权重,并对其权值进行了可靠性分析.利用线性加权模型得出应急适应能力评价结果.最后,以北京市某应急避难所作为实例进行了计算.结果表明,该应急避难所应急适应能力处于良好状态.     

Insights into simultaneous anammox and denitrification system with short-term pyridine exposure: Process capability,inhibition kinetics and metabolic pathways

• Short-term effect of the pyridine exposure on the SAD process was investigated. • The SAA at 150 mg/L pyridine reduced by 56.7% of the maximum value. • Inhibition kinetics models and inhibitory parameters were indicated. • Collaboration of AnAOB, HDB and PDB promoted the SAD. • Possible metabolic pathways of nitrogen and pyridine were proposed. In-depth knowledge on the role of pyridine as a bottleneck restricting the successful application of anammox-based process treating refractory coking wastewater remains unknown. In this study, the effect of short-term pyridine addition on a simultaneous anammox and denitrification (SAD) system fed with 25–150 mg/L pyridine was explored. The short-term operation showed that the highest total nitrogen (TN) removal efficiency was achieved at 25–50 mg/L of pyridine. As the pyridine addition increased, the contribution of the anammox pathway in nitrogen removal decreased from 99.3% to 79.1%, while the denitrification capability gradually improved. The specific anammox activity (SAA) at 150 mg/L pyridine decreased by 56.7% of the maximum SAA. The modified non-competitive inhibition model indicated that the 50% inhibitory concentration (IC₅₀) of pyridine on anammox was 84.18 mg/L and the substrate inhibition constant (K_i) of pyridine for self-degradation was 135.19 mg/L according to the Haldane model. Moreover, high-throughput sequencing confirmed the abundance of Candidatus Kuenenia as the amount of anammox species decreased, while the amounts of denitrifiers and pyridine degraders significantly increased as the pyridine stress increased. Finally, the possible pathways of nitrogen bioconversion and pyridine biodegradation in the SAD system were elucidated through metagenomic analysis and gas chromatography/mass spectrometry results. The findings of this study enlarge the understanding of the removal mechanisms of complex nitrogenous pyridine-containing wastewater treated by the SAD process.     

Natural variability and correlations in the metabolic profile of healthy Eisenia fetida earthworms observed using ¹H NMR metabolomics

¹H NMR metabolomics can be used to assess the sub-lethal toxicity of contaminants to earthworms by identifying alterations in the metabolic profiles of contaminant- exposed earthworms in contrast to those of healthy (control) individuals. In support of this method this study sought to better characterize the baseline metabolic profile of healthy, mature earthworms of the species, Eisenia fetida, which is recommended for both acute and sub-lethal toxicity testing for soil contaminants. Profiles of D₂O-buffer extracted metabolites were determined using ¹H NMR spectroscopy and both inter-individual metabolic variability and pair-wise metabolic correlations were assessed. The control earthworm extracts exhibited low overall inter-individual metabolic variability, with a spectrum-wide median relative standard deviation (%RSD = standard deviation/mean × 100) of 14%, which suggests that the metabolic profile of E. fetida earthworms is well controlled in laboratory conditions and supports further use of this organism in environmental metabolomics research. In addition, strong positive correlations were detected between the levels of maltose, betaine, glycine, and glutamate as well as between the levels of lactate, valine, leucine, alanine, lysine, tyrosine, and phenylalanine which had not previously been reported. Since comparison of pair-wise metabolic correlations between control and treated organisms can reveal changes in the underlying pattern of biochemical relationships between the metabolites, identification of these significant metabolic correlations in control earthworms provides an additional characteristic that may be applied to delineate between control and treated earthworms in future NMR-based metabolomic studies.     

Critical review of EPS production, synthesis and composition for sludge flocculation

Extracellular polymeric substances(EPS) produced by microorganisms represent biological macromolecules with unfathomable potentials and they are required to be explored further for their potential application as a bioflocculant in various wastewater sludge treatment. Although several studies already exist on biosynthetic pathways of different classical biopolymers like alginate and xanthan, no dedicated studies are available for EPS in sludge. This review highlights the EPS composition, functionality, and biodegradability for its potential use as a carbon source for production of other metabolites. Furthermore, the effect of various extraction methods(physical and chemical) on compositional, structural, physical and functional properties of microbial EPS has been addressed. The vital knowledge of the effect of extraction method on various important attributes of EPS can help to choose the suitable extraction method depending upon the intended use of EPS. The possible use of different molecular biological techniques for enhanced production of desired EPS was summarized.     

Leaf metabolic influence of glyphosate and nanotubes on the Arabidopsis thaliana phyllosphere

Chemical exposure can indirectly affect leaf microbiota communities, but the mechanism driving this phenomenon remains largely unknown. Results revealed that the co-exposure of glyphosate and multi-carbon nanotubes (CNTs) caused a synergistic inhibitory effect on the growth and metabolism of Arabidopsis thaliana shoots. However, only a slight inhibitory effect was induced by nanotubes or glyphosate alone at the tested concentrations. Several intermediate metabolites of nitrogen metabolism and fatty acid synthesis pathways were upregulated under the combined treatment, which increased the amount of energy required to alleviate the disruption caused by the combined treatment. Additionally, compared with the two individual treatments, the glyphosate/nanotube combination treatment induced greater fluctuations in the phyllosphere bacterial community members with low abundance (relative abundance (RA) <1%) at both the family and genus levels, and among these bacteria some plant growth promotion and nutrient supplement related bacteria were markable increased. Strikingly, strong correlations between phyllosphere bacterial diversity and metabolites suggested a potential role of leaf metabolism, particularly nitrogen and carbohydrate metabolism, in restricting the range of leaf microbial taxa. These correlations between phyllosphere bacterial diversity and leaf metabolism will improve our understanding of plant-microbe interactions and the extent of their drivers of variation and the underlying causes of variability in bacterial community composition.