Chemical Variability of the Needle Oil of Juniperus communis ssp. alpina from Corsica

The composition of 109 samples of essential oil isolated from the needles of Juniperus communis ssp. alpina growing wild in Corsica was investigated by GC (in combination with retention indices), GC/MS, and ¹³C‐NMR. Forty‐four compounds accounting for 86.7–96.7% of the oil were identified. The oils consisted mainly of monoterpene hydrocarbons, in particular, limonene (9.2–53.9%), β‐phellandrene (3.7–25.2%), α‐pinene (1.4–33.7%), and sabinene (0.1–33.6%). The 109 oil compositions were submitted to k‐means partitioning and principal component analysis, which allowed the distinction of two groups within the oil samples. The composition of the major group (92% of the samples) was dominated by limonene and β‐phellandrene, while the second group contained mainly sabinene beside limonene and β‐phellandrene.     

Catechin and Catechin Fractions as Biochemical Markers to Study the Diversity of Indian Tea (Camellia sinensis (L.) O. Kuntze) Germplasm

The heterogeneous Indian tea germplasm includes ‘China’, ‘Assam’, ‘Cambod’, and their hybrids which were evaluated using biochemical markers viz., total catechin and their fractions, for varietal identification and characterization. Principal component analysis (PCA) of biochemical characters showed that the total catechin and trihydroxylated catechin has higher eigenvalues. The first two principal components (PCs) could differentiate more than 90% of the clones studied. This grouping based on first two principal component matrices differentiated ‘China’, and their hybrids with ‘Assam’ and ‘Cambod’ variety. Morphologically indistinct large‐leaved ‘Cambod’ variety and ‘Assam’ varieties could not be differentiated using biochemical markers, since both varietal types taxonomically belong to a single species. Clones of ‘China’ type showed low total catechin content and catechin ratio which are distinctly grouped. The ‘China–Assam’ and ‘China–Cambod’ hybrids formed intermediate groups between ‘China’ PC group and ‘Cambod’/‘Assam’ PC groups, providing evidence for genetic control of catechin ratio variation. Tea clones which are differentially positioned in the PC group could be explained based on the genetic contribution by other varietal type as parents. This biochemical characterization will be a useful tool in the development of quality‐tea clones with different proportion of total catechin and their fractions.     

基于独立元分析和非线性指数分析的脑电信号中伪迹分量的自动去除

脑电(electroencephalography,EEG)信号中不可避免地存在着眼动、心跳、肌电信号以及线性噪声等伪迹干扰,这些伪迹的存在极大地影响了脑电信号分析的准确性,因此在进行脑电信号分析前需要去除伪迹干扰。为了有效地去除伪迹,结合独立元分析和非线性指数分析,提出一种自动识别并去除脑电信号中伪迹分量的方法。该方法还可同时用于提取脑电信号中的基本节律如!波等。相应的模拟与实际脑电数据的实验结果表明所提议的方法具有很好的识别和去除脑电信号伪迹分量的性能。     

基于独立元分析的脑磁图源定位

在脑磁图源定位问题中,通常感兴趣的是脑内众多神经活动源中的一个或几个,而传统源定位方法,如多信号分类方法,需要将所有源的位置都确定后,通过重组信号波形才能获得所感兴趣源的位置信息。为了提高定位效率,文章作者提出了一种结合独立元分析的脑磁图源定位方法。实验结果表明,该方法能加快定位的速度,同时能够在一定程度上克服噪声的影响,具有更强的抗噪声能力。     

地区农业耕作模式的综合评价优化法

提出一种系统的综合评价方法对广东三水市种植业18种耕作模式进行综合评价．该法克服了仅用一种方法在评价中的片面性,使评价结果更加全面、客观,同时解决了评价结果总存在差异的现象．此外,还提出用指标客观权重进行综合评价更合理、更可靠．     

主成分分析法用于西洋参样品分类研究

建立西洋参药材分类方法;采用电感耦合等离子体质谱(ICP-MS)法对12个西洋参样品中的15种无机元素的含量进行测定,用高效液相色谱(HPLC)法测定上述样品中的7种人参皂苷的含量,用蒽酮-硫酸法测定其中多糖的含量;进而采用主成分分析法(PCA)对所测得的西洋参样品的23个变量进行分类研究;12个西洋参样品能得到合理的分类,而各人参皂苷的含量是决定西洋参样品分类的第1关键因素,元素Mn、Cu、As、Ni、Mo以及多糖的含量是第2关键因素;主成分分析法是西洋参分析分类的有效方法。     

基于主成分分析的古树土壤肥力综合评价

以广州市海珠区登记在册的40株古树为研究对象,调查其生长状况,采集土壤测定pH、EC值、容重、通气度、有机质、全N、全P、全K、水解N、有效P、速效K含量等11项理化指标,采用主成分分析和聚类分析对古树土壤肥力进行综合评价.结果表明:海珠区大多数古树土壤EC值偏低(<0.35 mS·cm-1),表现为强变异;土壤有机质...     

Combining mitochondrial and nuclear evidences: a refined evolutionary history of Erebia medusa (Lepidoptera: Nymphalidae: Satyrinae) in Central Europe based on the COI gene

We aim to infer a combined scenario for the evolution of the Woodland Ringlet, Erebia medusa, in Central Europe based on analyses of part of the mitochondrial cytochrome oxydase subunit I (COI) and a published allozyme data set. We sequenced 529 bp of COI for 158 butterflies from 32 populations from almost the entire western distribution range of the species. We applied population genetic [spatial analysis of molecular variance (samova )] and phylogeographical analyses as well as coalescence simulation to test if the published allozyme scenario supports or contradicts the observed haplotype distribution. We recorded 16 haplotypes of which four represent a total of 82%. samova grouped the 32 populations into four geographically coherent groups: (1) western Central Europe, (2) Central Europe, (3) eastern Central Europe and (iv) western Pannonia. Mismatch distribution analyses and haplotype networks are in coincidence with constant population growth and reveal a relatively shallow phylogeographical structure. We evaluated the level of discordance between population histories and gene trees using Slatkins s and the deep coalescence statistics based on our mtDNA data. These estimators decline the previously published allozyme scenario of survival in different extra‐Mediterranean refugia in Europe with an onset of differentiation at the beginning of the last ice age some 70 000 years ago. However, it supports a refined scenario if we assume an onset of vicariance driven differentiation in these refugia after the end of the middle Würm interstadials some 30 000 years ago. Therefore, the general evolutionary history of this species in Europe apparently is very recent. Most probably, areas adjoining the high mountain regions as Alps and northern Carpathians were of great importance for the late Würm glacial survival of species like Erebia medusa.     

不同人工代花粉对蜂群群势和生产性能的影响

早春将群势、蜂王年龄和质量基本一致的25群意大利蜜蜂Apis melliferaL.,随机分为5个处理,分别饲喂纯花粉和4种不同的人工代用花粉,观测它们对蜂群群势和生产性能的影响。结果表明,含有添加剂的各代用花粉组与纯花粉组的蜂群的蜂子数量差异均不显著,但均显著高于纯豆粕组(P<0.01);各组产蜜量随着纯花粉所占比例的减少而呈现递减的趋势,但饲喂含有60%花粉+40%豆粕+添加剂1组与纯花粉组没有明显的差异;含有添加剂的各代用花粉组的王台接受率均显著高于纯花粉组(P<0.01);饲喂含有添加剂的各代用花粉组与饲喂纯花粉组相比,王浆产量及蜂王浆中的10-HDA、水分、蛋白质的含量及酸度均没有差异。     

Association Tests for a Censored Quantitative Trait and Candidate Genes in Structured Populations with Multilevel Genetic Relatedness

Summary Several statistical methods for detecting associations between quantitative traits and candidate genes in structured populations have been developed for fully observed phenotypes. However, many experiments are concerned with failure‐time phenotypes, which are usually subject to censoring. In this article, we propose statistical methods for detecting associations between a censored quantitative trait and candidate genes in structured populations with complex multiple levels of genetic relatedness among sampled individuals. The proposed methods correct for continuous population stratification using both population structure variables as covariates and the frailty terms attributable to kinship. The relationship between the time‐at‐onset data and genotypic scores at a candidate marker is modeled via a parametric Weibull frailty accelerated failure time (AFT) model as well as a semiparametric frailty AFT model, where the baseline survival function is flexibly modeled as a mixture of Polya trees centered around a family of Weibull distributions. For both parametric and semiparametric models, the frailties are modeled via an intrinsic Gaussian conditional autoregressive prior distribution with the kinship matrix being the adjacency matrix connecting subjects. Simulation studies and applications to the Arabidopsis thaliana line flowering time data sets demonstrated the advantage of the new proposals over existing approaches.