鄱阳湖生态经济区生态系统服务价值预测与驱动力

鄱阳湖生态经济区是我国第一个上升到国家战略的生态经济区。利用鄱阳湖生态经济区2004、2008、2012、2016年的MODIS数据,获得4个对应期的土地利用/覆盖数据,参照修订的单位面积生态系统服务价值当量表与灰色GM(1,1)模型,预测了2016-2024年(间隔2 a)的生态系统服务价值数据,并对引起生态服系统务价值变化的驱动力进行了分析。结果表明,鄱阳湖生态经济区在2004-2016年间,草地、建设用地和未利用地面积增加,耕地、林地、水域面积减少,但2016-2024年的预测值变化率仅为-0.17%,表明该研究区生态系统服务价值即将进入一个相对稳定的状态;驱动力分析表明,人为综合干扰在空间分布上以中等影响强度干扰为主,城镇化率是区域总生态系统服务价值降低的首要驱动力,其次分别为非农业人口、人口密度、第一产业GDP、第二产业GDP、固定资产投资额、总GDP及第三产业GDP。建议加强土地利用规划与调控,控制城镇化建设用地扩展,调整产业结构、降低污染,促进鄱阳湖生态经济区总生态系统服务价值的提升。     

Control of glyphosate uptake and metabolism in Pseudomonas sp. 4ASW

Abstract The tandem mini-exon gene repeat is an ideal diagnostic target for trypanosomatids because it includes sequences that are conserved absolutely coupled with regions of extreme variability. We have exploited these features and the polymerase chain reaction to differentiate Phytomonas strains isolated from phloem, fruit or latex of various host plants. While the transcribed regions are nearly identical, the intergenic sequences are variable in size and content (130–332 base pairs). The mini-exon genes of these phytomonads can therefore be distinguished from each other and from the corresponding genes in insect trypanosomes, with which they are oft confused.     

Construction and characterisation of a yeast artificial chromosome library containing five haploid sugarbeet (Beta vulgaris L.) genome equivalents

A yeast artificial chromosome (YAC) genomic library of Beta vulgaris was constructed in the pYAC4 vector. High-molecular-weight DNA was prepared from agarose-embedded leaf protoplasts from a triploid cultivar. The library was found to contain 33,500 clones in an ordered array of microtiter plates. Mean size of the inserts was estimated to be 135 kb, and the library should therefore represent the equivalent of five haploid genomes. The library was characterised for the presence of highly repetitive, chloroplast and single-copy sequences. In order to isolate single-copy sequences, 18 pools of DNA, each from 1920 individual YAC clones, were prepared for rapid screening of the library by the polymerase chain reaction. The results of these screenings showed that the number of isolated clones was at or near the frequency expected.     

基于农业生态服务价值的农业绿色GDP核算——以安塞县为例

将传统GDP绿色化,也就是“绿色GDP”是国民经济核算研究和探索的热点。从微观层面对农业生产进行绿色GDP核算,认为农业绿色GDP不仅包含传统的产品价值,还应包括农业对人类社会经济系统的生态服务价值,并以基于生态系统服务价值的“农业绿色GDP=农业常规GDP＋农业生态GDP”的公式核算了安塞县的绿色GDP。结果表明：（1）安塞县2000年的农业生产总值为29187万元,减去中间消耗为18972万元;（2）若考虑农业生态环境代价,则农业生产产值仅为6272．30万元,是农业常规GDP的33．06％,农业常规GDP背后至少隐含着66．94％的农业生态环境代价;（3）应用市场价值法、机会成本法、替代工程法、影子价格法等核算农业生态系统服务价值结果为504218．37万元,把农业生态系统服务价值作为农业系统的间接产出,则该县2000年的农业绿色GDP为510490．67万元。安塞县农业经济的获得背后至少有66．94％生态环境代价是依靠其农业生态系统的服务来提供和补偿的。     

Respiratory chain composition and activity in some thermotolerant streptomycetes

The cytochrome composition of membrane preparations from 3 thermotolerant species of Streptomyces was determined from difference spectra. All contained b, c and a-type haemoproteins and in addition, 2 species (Streptomyces thermoviolaceus and Streptomyces thermoflavus) possessed cytochrome oxidase d. A CO-reacting b cytochrome similar to cytochrome oxidase o could also be detected in all 3 organisms. Thermotolerance of the respiratory chains showed no correlation with cytochrome composition. In general, Streptomyces thermonitrificans had the most thermostable activities, whilst those of S. thermoviolaceus were the most thermolabile. Growth temperature exerted no qualitative effects on respiratory chain composition but did affect the thermostability of some substrate-supported oxidase activities.     

The Association of Phytoplasma with Stunting, Leaf Necrosis and Witches' Broom Symptoms in Magnolia Plants

In 1999–2000 a severe disease was observed on plants of four Magnolia spp. cultivated in a commercial nursery in Poland. Affected plants showed a progressive loss of vigour, were stunted, and had severely malformed leaves, leaf necrosis and witches' broom. Phytoplasma was detected in magnolias with severe symptoms and in dodder-inoculated Catharanthus roseus seedlings by nested polymerase chain reaction (PCR) assay with primer pair R16F1/R0 followed by universal (rA/fA) and group specific (R16(I)F1/R1) primer pairs which amplified a fragment of phytoplasma 16S rDNA. The PCR products (560 bp or 1.1 kb) of all samples used for restriction fragment length polymorphism analysis after digestion with endonuclease enzymes Alu I and Mse I produced the same profile which corresponded to that of an aster yellows phytoplasma reference strain. Phytoplasma DNA was detected throughout the growing season in roots, stems and young but not mature leaves. Electron microscope examination of the ultra-thin sections of the leaf and stem of diseased magnolias showed collapsed and degenerated sieve tube elements with wall thickening. The reduced lumen of these sieve elements contained numerous vesicles and membrane-bound structures, but no typical phytoplasma cells. This is the first report of aster yellows phytoplasma in magnolia identified by molecular assays.     

Functional intracellular antibody fragments do not require invariant intra-domain disulfide bonds

Intracellular antibody fragments that interfere with molecular interactions inside cells are valuable in investigation of interactomes and in therapeutics, but their application demands that they function in the reducing cellular milieu. We show here a 2.7-Å crystal structure of intracellular antibody folds based on scaffolds developed from intracellular antibody capture technology, and we reveal that there is no structural or functional difference with or without the intra-domain disulfide bond of the variable domain of heavy chain or the variable domain of light chain. The data indicate that, in the reducing in vivo environment, the absence of the intra-domain disulfide bond is not an impediment to correction of antibody folding or to interaction with antigen. Thus, the structural constraints for in-cell function are intrinsic to variable single-domain framework sequences, providing a generic scaffold for isolation of functional intracellular antibody single domains.     

Mitogenomic phylogeny of the Percichthyidae and Centrarchiformes (Percomorphaceae): comparison with recent nuclear gene-based studies and simultaneous analysis

Delineation of the fish family Percichthyidae (Percomorphaceae) has a long and convoluted history, with recent morphological-based studies restricting species members to South American and Australian freshwater and catadromous temperate perches. Four recent nuclear gene-based phylogenetic studies, however, found that the Percichthyidae was not monophyletic and was nested within a newly discovered inter-familial clade of Percomorphaceae, the Centrarchiformes, which comprises the Centrarchidae and 12 other families. Here, we reexamined the systematics of the Percichthyidae and Centrarchiformes based on new mitogenomic information. Our mitogenomic results are globally congruent with the recent nuclear gene-based studies although the overall amount of phylogenetic signal of the mitogenome is lower. They do not support the monophyly of the Percichthyidae, because the catadromous genus Percalates is not exclusively related to the freshwater percichthyids. The Percichthyidae (minus Percalates) and Percalates belong to a larger clade, equivalent to the Centrarchiformes, but their respective sister groups are unresolved. Because all recent analyses recover a monophyletic Centrarchiformes but with substantially different intra-relationships, we performed a simultaneous analysis for a character set combining the mitogenome and 19 nuclear genes previously published, for 22 centrarchiform taxa. This analysis furthermore indicates that the Centrarchiformes are divided into three lineages and the superfamily Cirrhitoidea is monophyletic as well as the temperate and freshwater centrarchiform perch-like fishes. It also clarifies some of the relationships within the freshwater Percichthyidae.     

血清Irisin、SOST、H2S与膝骨关节炎合并骨质疏松症患者骨密度、骨代谢标志物的相关性及其预测价值

摘要 目的：探讨血清鸢尾素（Irisin）、骨硬化蛋白（SOST）、硫化氢（H₂S）与膝骨关节炎（KOA）合并骨质疏松症（OP）患者骨密度、骨代谢标志物的相关性,分析Irisin、SOST、H₂S预测KOA合并OP的价值。方法：选取2020年4月至2023年4月我院收治的179例KOA患者,根据是否合并OP将其分为OP组（68例）和非OP组（111例）。检测血清Irisin、SOST、H₂S和骨代谢标志物骨钙素（OC）、骨碱性磷酸酶（BALP）、Ⅰ型原胶原N-端前肽（PINP）、抗酒石酸酸性磷酸酶异体（TRACP5b）水平,股骨颈、腰椎L1～4骨密度。Pearson分析血清Irisin、SOST、H₂S与股骨颈、腰椎L1～4骨密度和血清骨代谢标志物的相关性,受试者工作特征（ROC）曲线分析血清Irisin、SOST、H₂S对KOA合并OP的预测价值。结果：OP组血清Irisin、H₂S、OC、BALP、PINP水平,股骨颈、腰椎L1～4骨密度低于非OP组（P＜0.05）,TRACP、SOST水平高于非OP组（P＜0.05）。OP组血清Irisin、H₂S水平与股骨颈、腰椎L1～4骨密度,血清OC、BALP、PINP水平呈正相关（P＜0.05）,与血清TRACP水平呈负相关（P＜0.05）;SOST水平与股骨颈、腰椎L1～4骨密度,血清OC、BALP、PINP水平呈负相关（P＜0.05）,与血清TRACP水平呈正相关（P＜0.05）。Irisin、SOST、H₂S预测KOA合并OP的曲线下面积为0.784、0.773、0.755,联合预测KOA合并OP的曲线下面积为0.908,高于单独预测。结论：KOA合并OP患者血清Irisin、H₂S水平降低、SOST水平增高,低水平Irisin、H₂S和高水平SOST与骨密度降低、骨代谢异常有关,可用于预测KOA合并OP患者骨代谢异常状态和骨质流失风险。