A new dissimilarity measure and a new optimality criterion in phytosociological classification

A new dissimilarity measure, Uppsala dissimilarity, is proposed. It is a Manhattan-type measure in between the Canberra and Gower measures, based on the differences between scores in relevés compared, but it also takes both the sums of scores and the difference between maximum and minimum score into account. The measure is considered realistic for phytosociological material.A new optimality criterion has been developed after unsatisfactory results had been obtained with the DOL criterion (Popma et al. 1983) which was developed previously by our group. Problems with DOL were especially met when the criterion was applied to the distribution of only one species over the cluster array obtained. The new criterion takes both internal cluster homogeneity and between-cluster dissimilarity into account. Between-cluster dissimilarity is calculated for all other clusters and not only for the nearest neighbour, as in DOL. The new criterion has both an unweighted form: SOM, and a form with weighting for cluster size: SWOM.This new criterion was successfully applied to the evaluation of the sharpness of distribution of individual species over cluster arrays, under the name of SIM: species indication measure and SWIM, species weighted indication measure.The measures were applied to some test data. Differences between the unweighted and weighted forms were found which could not be easily interpreted.Some remarks are made on the coherence of d-SAHN and h-SAHN approaches in agglomerative clustering within the new strategy proposed.Abbreviations DOL = Detection of Optimal Level - S(W)IM = Species (Weighted) Indication Measure - S(W)OM = Standardized (Weighted) Optimality Measure - UD = Uppsala Dissimilarity measure - WPGMA = Weighted Pair-Group Method Average linking clustering - SAHN = Sequential Agglomerative Hierarchical Non-overlapping clustering     

Reliability and stability of dream recall frequency.

Although a large number of studies investigating factors affecting dream recall frequency (DRF) have been carried out, research investigating the reliability and stability of DRF is scarce. Dream diaries of 196 participants kept over at least 28 days were analyzed. The results of the present study indicate that a time period of 2 weeks was sufficient to obtain reliable measurements of interindividual differences in DRF. Despite the high day-to-day fluctuations of dream recall, the stability of this variable was very high. Studies that investigate the stability of DRF by means of other methodological approaches (e.g., questionnaire scales, laboratory awakenings) and over longer time periods (e.g., 1 year) should be carried out to complement the present findings. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Performance of the Peto odds ratio compared to the usual odds ratio estimator in the case of rare events

For the calculation of relative measures such as risk ratio (RR) and odds ratio (OR) in a single study, additional approaches are required for the case of zero events. In the case of zero events in one treatment arm, the Peto odds ratio (POR) can be calculated without continuity correction, and is currently the relative effect estimation method of choice for binary data with rare events. The aim of this simulation study is a variegated comparison of the estimated OR and estimated POR with the true OR in a single study with two parallel groups without confounders in data situations where the POR is currently recommended. This comparison was performed by means of several performance measures, that is the coverage, confidence interval (CI) width, mean squared error (MSE), and mean percentage error (MPE). We demonstrated that the estimator for the POR does not outperform the estimator for the OR for all the performance measures investigated. In the case of rare events, small treatment effects and similar group sizes, we demonstrated that the estimator for the POR performed better than the estimator for the OR only regarding the coverage and MPE, but not the CI width and MSE. For larger effects and unbalanced group size ratios, the coverage and MPE of the estimator for the POR were inappropriate. As in practice the true effect is unknown, the POR method should be applied only with the utmost caution.     

海南岛腰果角盲蝽的研究

腰果角盲蝽(Helopeltis sp.)为我国腰果树的新害虫,在海南岛严重为害腰果树嫩梢、花枝、嫩叶、幼坚果及果梨.据1982年调查,坚果被害率最高可达100%,其中被害至干枯的达7%.腰果角盲蝽广布于海南岛,除为害腰果树外还为害可可、胡椒、芒果、番石榴、茶树等多种经济作物.此虫年发生12代,一代需16—80天.建议对腰果植株进行合理修枝、及时除去带卵枝条及在梢期、花期和座果期各喷药一次对其进行防治.     

Shannon's Measure and its Use in the Analysis of Cancer Data

In this paper, Shannon's measure of uncertainty is explored in the analysis of cancer data. The term ‘cancer diversity’ is defined and its potential application is illustrated.     

Positive implicit attitudes toward odor words

Associations between certain odors and for instance health effects may lead to positive or negative attitudes toward these odors. However, in experiments we conducted using the Implicit Association Test (IAT), we encountered attitudes even to odor "words." The IAT is based on the principle that reaction times measuring the association between words from a target dimension (in this case, odor vs. a neutral reference category) and an attribute dimension (i.e., positive or negative words) reflect the attitude to the target, where attitude-congruent associations between target and attribute are reflected by shorter reaction times. In a first experiment, we found distinctly positive attitudes to the concept odor in a student sample, which was replicated in a second experiment. In the main experiment, subjects in the aromatherapy group, who prefer using scented consumer products for relaxation purposes, showed a significantly more positive attitude toward odor words in the IAT than a control group, who did not have such a preference. The fact that results from the implicit test were not always associated with explicitly stated attitudes toward the odor words attests to the fact that the IAT measures the attitude of interest in a different way. As such, the IAT has added value in circumstances where explicit tests can be biased.     

心电信号的计算机分析—特征检测

心电信号的特征检测是心电计算机分析的核心内容,本文报导了作者采用的方法,包括Ｒ波定位,ＱＲＳ波群区分点检测,Ｐ波,Ｔ波区发点的检测,Ｕ波的检测以及Ｐ－Ｑ,Ｓ－Ｔ段的分析,测试结果表明这些方法的优越性和可靠性,在ＳＴ段分析上有较大突破。     

Measurement of the Relation of Two Characteristics

The four-field table measure K (appearing as K₁, K₂), which is only a coefficient-measure, can, by means of a useful transformation, be transformed into a real measure k by means of a graduated scale. The measure k can be compared with other k-values and, futhermore, reveals directly, by how many per cent the one characteristic can be looked upon as being determined by the other characteristic of the two characteristics under review.     

A simple and species-independent coding measure

We present a coding measure which is based on the statistical properties of the stop codons, and that is able to estimate accurately the variation of coding content along an anonymous sequence. As the stop codons play the same role in all the genomes (with very few exceptions) the measure turns out to be species-independent. We show results both for prokaryotic and for eukaryotic genomes, indicating, first, the accuracy of the measure, and, second, that better prediction is achieved if the measure is applied on homogeneous, isochore-like sequences than if it is applied following the standard moving window approach. Finally, we discuss on some of the possible applications of the measure.     

基于复杂性度量的表面肌电信号分类方法

提取表面肌电信号的复杂性测度信息,利用原始数据的复杂度指标构造特征矢量对四种前臂动作进行分类,取得了较好的识别效果.通过比较,发现基于原始数据的复杂度指标在分类性能上要优于基于重构序列的复杂度.肌电信号的复杂度算法简单,适合短数据运算,能够满足实时处理的要求.作为一种新的肌电信号特征,复杂性测度也为生理与病理分析提供了新的思路.     

佛山市2004—2009年麻疹流行病学分析和防治措施探讨

通过分析近年来佛山市麻疹流行病学特征,为探讨麻疹控制措施提供理论依据。对2004—2009年麻疹发病情况进行描述性流行病学分析。结果显示,佛山市2004—2009年共报告麻疹病例3 599例,年平均发病率为10.19/10万;发病数前3位的区为顺德区、南海区、禅城区,占全市病例数的94.50%;4～8月为高发季节,占总病例数的66.60%;6岁以下儿童及15岁以上人群是麻疹发病主要人群,分别占总病例数的62.86%、31.54%;8月龄以下儿童发病数占14.48%;病例以流动人口为主,占总病例数的94.78%;有明确免疫史病例仅占总病例数10.22%。佛山市麻疹发病有回升趋势,疫情形势严峻。实施麻疹疫苗强化免疫和查漏补种是控制麻疹的有效措施;同时应采取加强流动人口管理,提高麻疹疫苗常规免疫接种率和及时率,加强麻疹监测和入学、入托查验证管理,控制医院内感染,强化疫区处理等综合防控措施。     

Timing matters

Cells are entities in space and time. Systems biology strives to understand their composition, structural organization as well as dynamic behavior under different conditions. Here, measures for dynamic properties such as characteristic times, time hierarchy and time-dependent response are reviewed. Using a number of examples from yeast and micro-organism systems biology, the importance of considering the timing in experimental and theoretical research is discussed.     

温带臭虫生活史中各龄若虫及成虫形态的进一步描述

本通过对温带臭虫生活史中各龄若虫及成虫形态的进一步描述,首次提出臭虫度量的长度随虫龄的成熟而逐步增大。身长与体宽之比基本保持在1：1.8左右,前胸宽及前胸长之比在3：1左右;除一龄若虫外,其基本基缘毛丛的数量。每增加一龄,其毛从根数也增加一根,即n 1,这在臭虫形态分类及对臭虫的进一步研究和防治有着重要的意义。     

美国医生信息公开的指标遴选及内容研究

医生质量信息公开具有改善患者选择,促进医生质量提升以及缓解医患纠纷的重要意义。其中质量指标遴选及测量的科学性直接影响公开的社会认同度和效果。以美国医疗保险和救助中心的医生比较网站为例,介绍了医生信息公开的内容,包含患者安全、糖尿病、心脏病及预防保健多个维度指标及公开指标的遴选过程;重点探讨借鉴其多元及规范的公开内容、通过多种渠道与利益集团合作制定最佳公开质量指标,公开前测试指标的稳定性和科学性,开发疾病模块级综合指标等科学的指标遴选举措,为我国公开医生质量信息提供循证依据。     

Relational diversity

In biology, the measurement of diversity traditionally focusses on reporting number of unambiguously distinguishable types, thus referring to qualitative (discontinuously varying) traits. Inclusion of frequencies or other weights has produced a large variety of diversity indices. Quantitative (continuously varying) traits do not readily fit into this perspective. In fact, in the context of quantitative traits, the concept of diversity is not always clearly distinguished from the (statistical) notion of dispersion. In many cases the ambiguity even extends to qualitative traits. This is at variance with the broad spectrum of diversity issues ranging, e.g., from ecological and genetic aspects of diversity to functional, structural, systematic, or evolutionary (including phylogenetic) aspects. In view of the urgent need for a more consistent perspective, it is called to attention that all of these aspects, whether of qualitative or quantitative nature, can be gathered under the common roof of binary relations (for qualitative traits two objects are related, for example, if they share the same trait state). A comprehensive concept of (relational) diversity can be developed in two steps: (1) determine the number of unrelated pairs of objects among all admissible pairs as a measure of implicit (relative) diversity, (2) invoke the concept of effective number to transform the implicit measure of diversity into an explicit (absolute) measure. The transformation operates by equating the observed implicit diversity to the implicit diversity obtained for the ideal model of an equivalence relation with classes of equal size. The number of these classes specifies the effective number as an explicit measure of diversity. The wealth of problems that can be treated from this unified perspective is briefly addressed by classifying and interpreting established diversity indices in the light of relational diversity. Desirable applications to the above-mentioned aspects are specified with the help of types of relations such as order, hierarchical, and tree relations. Corresponding biological issues including taxonomic community diversity, mating system, food web, sociological, cladistic and phylogenetic, or hypercycle diversity are suggested for future consideration.     

高寒嵩草草甸植物群落数量特征对不同利用强度的短期响应

以时空转换的方法确定典型高寒嵩草草甸演替过程的4个关键阶段,以此为研究对象,探讨冬春放牧对高寒草甸生态系统植物功能群数量特征的影响,及在现有放牧制度下不同退化程度草甸植物群落数量特征对禁牧和减牧的响应。结果表明:当禾本科功能群在群落中的地位大于等于莎草科功能群时,减牧可以提高禾本科和莎草科功能群而降低杂类草功能群在群落中的地位;禁牧可以提高禾本科和杂类草功能群而降低莎草科功能群在群落中的地位。当莎草科功能群在群落中的地位大于禾本科功能群,且莎草科功能群以根茎密丛型植物为优势种时,放牧强度降低可以提升禾本科功能群但降低莎草科功能群在群落中地位;而莎草科功能群以密丛型植物为优势种时,放牧强度降低可增加莎草科功能群在群落中的地位,而禾本科功能群在群落中地位的变化取决于草地中裂缝的性质,一定强度的裂缝可以增加禾本科功能群在群落中的地位。因此,退化高寒嵩草草甸自我恢复方式的选择取决于可食性牧草组分、地表特征及恢复目标。当可食性牧草以禾本科功能群为优势种(或禾本科同莎草科功能群为共优种)时,减牧容易提高草地的牧用价值,而禁牧容易增加草地中杂类草功能群的比例,不利于畜牧业生产;当高寒嵩草草甸可食性牧草以莎草科功能群为优势种时,禁牧较减牧更容易加快其牧用性的恢复。小嵩草草甸草毡表层开裂期为该演替系列的激变期,而由于冻融交替形成的裂缝是草地恢复的新生带,如加以利用可以加速草地恢复。     

Markowitz模型与局势决策

本文论证了局势决策乃是随机优势原则下的Markowitz模型的一种特殊情况和局势决策所具有的优良性质,证实了局势决策的可行性,从而获得了一种简便易行的实用决策方法。     

生物多样性评价软件BiodiversityMapping的设计与实现

针对目前国内生物多样性相关软件缺乏的情况,利用可视化开发方法和地理信息系统组件包shape Viewer Objects开发了一个综合性的生物多样性评价软件BiodiversityMapping。该软件运行于Windows98／NT操作系统下,是一个32位Windows应用软件;可以计算8类37种d、D生物多样性测度并能利用地理信息系统技术将结果空间化表达。利用该软件计算了北京东灵山地区3个研究区域(小龙门、梨园岭和东灵山主峰)内11个生境中大步甲属(Carabus)昆虫的Shannon-Wiener多样性指数并制图,然后对这3个地区进行了右尾和排序。结果表明,BiodjversityMapping软件能够准确方便地计算多种生物多样性测度,是生物多样性评价的一个有力工具。     

广州市城市生态环境问题与防治对策

本文分析了广州市城市生态环境的大气、水、噪声、固体废物,园林绿化等问题,提出了做好城市生态规划,加强城市生态环境管理,扩大城市园林绿化,以森林包围城市,运用政策法令调控城市生态环境等防治对策。     

不同施肥对退化稻田土壤肥力恢复的影响

为了探明不同施肥修复措施对退化水稻土壤肥力的修复作用,自2005年起采用盆栽试验连续3年对长期缺肥退化水稻土进行了土壤肥力培肥试验研究。结果表明:6种施肥修复措施均可以显著地改善退化水稻土的肥力特征,土壤有机质含量最多提高了14.0%,土壤有效磷显著增加,最高增加量达到39.0mg.kg-1,土壤速效钾均恢复到中等水平(80mg.kg-1)以上,但土壤碱解氮除水稻专用复合肥(ZY)处理基本维持试验前水平外,其他施肥措施均有所下降;不同施肥修复措施均可明显地提高土壤微生物数量、微生物活性以及微生物生物量C、N、P含量,但以有机无机肥配合效果最佳;有机无机肥配合还可以促进稻谷产量和显著提高肥料农学效率;对于长期不施肥导致的退化稻田土壤肥力的修复以在施用水稻专用复合肥的基础上配施有机肥的效果最佳。