数据挖掘在智能交通系统中的应用分析

介绍了数据挖掘的基本概念及应用背景;讨论了作为复杂巨系统的智能交通系统的信息特性及其不确定性;指出控制的实时性要求在交通流状态迅速变化条件下尽快求出最优或次优控制变量,传统的基于数学建模方法的局限性决定其无法解决这些难题;对应用数据挖掘技术处理智能交通系统的某些具体问题进行了分析。     

贵州传统小曲酵母菌分子指纹图谱分析

采用26S rRNA基因D1/D2区域序列分析方法将59株分离自贵州5个不同地区传统小曲的酵母菌鉴定为6个酵母菌种：1株阿萨丝孢酵母（Trichosporon asahii）、32株扣囊覆膜孢酵母（Saccharomycopsis fibuligera）、8株Saccharomycopsismalanga、4株伯顿丝孢毕赤酵母（Hyphopichia burtonii）、6株异常威克汉姆酵母（Wickerhamomyces anomalus）和8株酿酒酵母（Saccharomyces cerevisiae）。本研究展示了6个酵母菌种的WL培养基菌落特征和5.8S rRNA基因ITS区限制性片段长度多态性酶切图谱特征,为这6个菌种的快速鉴定提供依据。在菌种鉴定的基础上,本研究进一步采用串联重复-tRNA指纹图谱法分析酵母菌的种内差异,共展示了17个基因型,H. burtonii、W. anomalus与S. fibuligera分别鉴定出4、3种和8种基因型,其中S. fibuligera基因型10、11、12、15、16与17之间的遗传关系较近,而其余菌种内部基因型之间的遗传关系相对较...     

Bioaccumulation of silver in ectomycorrhizal and saprobic macrofungi from pristine and polluted areas

Macrofungi are effective accumulators of Ag. This study provides a comprehensive review of this phenomenon supported by original data on the Ag concentrations of macrofungi from pristine and Ag-polluted areas. In pristine areas, the median Ag concentrations of ectomycorrhizal (ECM) and saprobic (SAP) macrofungi were 0.79 and 2.94 mg kg^− 1, respectively. In these areas, hyperaccumulation thresholds for Ag in ECM and SAP macrofungi are proposed as 100 and 300 mg kg^− 1, respectively. In a Ag-polluted area, the Ag concentrations in macrofungi (ECM and SAP) were significantly elevated with the median value of 24.7 mg kg^− 1 and the highest concentrations in Amanita spp. of the section Vaginatae (304-692 mg kg^− 1). The intracellular speciation of Ag in fruit-bodies of the Ag-accumulator Amanita submembranacea was inspected by size exclusion chromatography followed by sulfhydryl-specific fluorimetric assays of ligands using reverse phase high-performance liquid chromatography and improved polyacrylamide gel electrophoresis. Virtually all Ag was found to be intracellular and sequestered in the major 7 kDa and minor 3.3 kDa complexes. The lack of glutathione and phytochelatins and the presence of a single 3 kDa sulfhydryl-containing peptide in the isolated Ag-complexes suggest that detoxification of Ag in A. submembranacea may rely on metallothionein. Vertical distribution of Ag in a polluted forest soil profile has shown substantial enrichment in organic horizons; in polluted technosol, the highest Ag concentrations were found in surface layers. Standardized EDTA extraction of Ag in both the investigated soil profiles showed relatively low Ag extractibility, generally within the range of 2.2-7.7% of total Ag content.     

Molecular Systematics of Polygonum minus Huds. Based on ITS Sequences

Plastid trnL-trnF and nuclear ribosomal ITS sequences were obtained from selected wild-type individuals of Polygonum minus Huds. in Peninsular Malaysia. The 380 bp trnL-trnF sequences of the Polygonum minus accessions were identical. Therefore, the trnL-trnF failed to distinguish between the Polygonum minus accessions. However, the divergence of ITS sequences (650 bp) among the Polygonum minus accessions was 1%, indicating that these accessions could be distinguished by the ITS sequences. A phylogenetic relationship based on the ITS sequences was inferred using neighbor-joining, maximum parsimony and Bayesian inference. All of the tree topologies indicated that Polygonum minus from Peninsular Malaysia is unique and different from the synonymous Persicaria minor (Huds.) Opiz and Polygonum kawagoeanum Makino.     

传统发酵香肠中菌种的分子生物学鉴定

为探究发酵香肠的微生物菌群的作用机理,利用传统的微生物学平板稀释分离法,分离出发酵香肠中酵母、大肠杆菌和乳酸菌等微生物,并提取其DNA,PCR扩增16S rDNA、ITS后测序,将测序结果与NCBI基因库中序列进行比对,MegAlign软件进行序列分析并构建系统发育树,结果表明,发酵香肠中富含德氏酵母、YSY1-6腐生葡萄球菌、德式乳酸乳杆菌亚种。     

车联网技术研究综述

针对严重的交通拥堵、交通事故与严峻的城市空气质量和能源问题,探讨了“车联网”和“智能交通系统”的内涵及关系,介绍了车联网基于感知层、网络层和应用层的“端—管—云”体系架构,重点分析了射频识别技术、智能传感技术、无线通信技术与配套标准研发等车联网关键技术的研究进展.在此基础上,分析展望了车联网发展的行业困境与未来的典型应用.分析结果表明,推动车联网配套标准开发、出台行业发展整体规划是车联网行业减少低水平重复、健康发展并走向深入整合应用的迫切要求.     

用ITS2鉴定芥辣类调味品中山葵、辣根和芥末组分

日式饮食中的芥辣类调味品主要以同属十字花科的山葵(Eutrema wasabi)、辣根(Armoracia rusticana)、芥末(mustard)做原料加工而成。利用核糖体DNA内部转录间隔区Ⅱ(Internal transcribed spacer 2,ITS2)技术快速、准确地鉴定出山葵、芥末和辣根,为该技术应用于芥辣类产品质量检测提供参考。以3种植物材料(山葵、辣根、白芥末)为实验材料,提取基因组DNA,通过引物ITS2_S2进行PCR扩增得到ITS2片段,测序结果通过生物信息学分析进行物种鉴定。MEGA7.0(Molecular evolutionary genetics analysis)分析ITS2序列结果表明,山葵、白芥末和辣根K2P(Kimura 2-parameter)遗传距离在0.088～0.171,均大于0.01,种间变异位点有36个,初步推断利用ITS2序列能将山葵、白芥末和辣根3物种区分开来。另外,GenBank中获得山葵以及近亲西北山嵛菜、辣根、芥末的ITS2序列,MEGA7.0进行种间序列分析,计算K2P,并用邻接法(Neighbor-joining,NJ)构建进化树,山葵与近亲西北山嵛菜聚为一支,棕芥末与白芥末、黑芥末聚为一大支,而辣根单独为一支。通过分析ITS2序列,发现山葵与近亲西北山嵛菜、辣根、芥末的种间K2P遗传距离在0.030～0.105,均大于0.01。研究表明,利用ITS2技术可以鉴别山葵、辣根和芥末等近缘物种,此技术可以用于芥辣类调味品特定原料成分鉴定及定量,为食品质量控制和食品安全提供科学依据。     

实时交通数据的筛选与恢复研究

实时交通数据的质量非常重要,因此本文全面地分析影响交通特性参数精度的因素,总结实时处理交通数据的必要性;探讨交通管理系统中筛选实时交通数据的四种方法;提出目前常用交通数据检测方法中存在的问题,对比分析后提出解决方案;并对未来信息采集和数据管理提出建议;研究实时交通数据问题诊断和恢复方法,即数据限定法和统计相关法,最后通过沪宁高速公路实例验证其可行性与科学性。     

A new putative Zygosaccharomyces yeast species isolated from traditional balsamic vinegar

The taxonomic status and species number of the genus Zygosaccharomyces have rapidly changed in the last years. In this study, two new osmotolerant Zygosaccharomyces strains isolated from traditional balsamic vinegar, viz. ABT301 and ABT601, were investigated to elucidate their taxonomic relationships with Zygosaccharomyces rouxii species. A multi-gene sequence approach was employed, including regions of the rDNA repeat [5.8S, two internal transcribed spacers (ITS) and the 26S D1/D2 domain], COX2 mitochondrial gene and two nuclear genes (SOD2 and HIS3). Cloning and sequence analysis of 5.8S-ITS rDNA revealed that these strains bear an unusual polymorphism for this region. Three highly divergent 5.8S-ITS sequences were detected, one identical to Z. rouxii, the other two showing some relatedness to Z. mellis. Sequence and gene number polymorphism was also observed for the protein-encoding nuclear genes SOD2 and HIS3, as two copies for each gene different from those found in Z. rouxii were detected. Analysis of the D1/D2 26S domain showed that ABT301 and ABT601 have only one type of D1/D2 sequence statistically different from that of Z. rouxii. The findings obtained in this work suggest that the genomic background of strains ABT301 and ABT601 is different from the other Zygosaccharomyces species. We speculated that they could belong to a new putative species related to Z. rouxii.     

Evaluation of ITS PCR and RFLP for Differentiation and Identification of Brewing Yeast and Brewery ‘Wild’ Yeast Contaminants

A reference library of ITS PCR/RFLP profiles was collated and augmented to evaluate its potential for routine identification of domestic brewing yeast and known ‘wild’ yeast contaminants associated with wort, beer and brewing processes. This library contains information on band sizes generated by restriction digestion of the ribosomal RNA‐encoding DNA (rDNA) internal transcribed spacer (ITS) region consisting of the 5.8 rRNA gene and two flanking regions (ITS1 and ITS2) with the endonucleases CfoI, HaeIII, HinfI and includes strains from 39 non‐Saccharomyces yeast species as well as for brewing and non‐brewing strains of Saccharomyces. The efficacy of the technique was assessed by isolation of 59 wild yeasts from industrial fermentation vessels and conditioning tanks and by matching their ITS amplicon sizes and RFLP profiles with those of the constructed library. Five separate, non‐introduced yeast taxa were putatively identified. These included Pichia species, which were associated with conditioning tanks and Saccharomyces species isolated from fermentation vessels. Strains of the lager yeast S. pastorianus could be reliably identified as belonging to either the Saaz or Frohberg hybrid group by restriction digestion of the ITS amplicon with the enzyme HaeIII. Frohberg group strains could be further sub‐grouped depending on restriction profiles generated with HinfI.