Estimation of low back moments from video analysis: a validation study

This study aimed to develop, compare and validate two versions of a video analysis method for assessment of low back moments during occupational lifting tasks since for epidemiological studies and ergonomic practice relatively cheap and easily applicable methods to assess low back loads are needed. Ten healthy subjects participated in a protocol comprising 12 lifting conditions. Low back moments were assessed using two variants of a video analysis method and a lab-based reference method. Repeated measures ANOVAs showed no overall differences in peak moments between the two versions of the video analysis method and the reference method. However, two conditions showed a minor overestimation of one of the video analysis method moments. Standard deviations were considerable suggesting that errors in the video analysis were random. Furthermore, there was a small underestimation of dynamic components and overestimation of the static components of the moments. Intraclass correlations coefficients for peak moments showed high correspondence (>0.85) of the video analyses with the reference method. It is concluded that, when a sufficient number of measurements can be taken, the video analysis method for assessment of low back loads during lifting tasks provides valid estimates of low back moments in ergonomic practice and epidemiological studies for lifts up to a moderate level of asymmetry.     

应用模糊聚类分析方法划分贵州含笑属植物区系地理成分

本文通过贵州含笑属Michelia植物介绍了植物区系地理成分划分的模糊聚类分析方法和步骤。这种方法较常规分析更能反映其本质特征,结果比较理想;此外,还能准确地反映各类地理成分之间的关系。     

脑磁图神经活动源数目的估计

在脑磁图信号的分析中,正确估计出脑磁图神经活动源的数目是进一步分析脑磁图信号的前提。目前广泛采用的信息论方法和主成分分析方法都是根据特征值来确定源的数目,这两种方法在源数目较多、噪声较强的情况下,会导致误判。该文提出了一种噪声调节自动阈值的脑磁图源数目判断方法,利用基于噪声调节的主成分分析并结合聂曼- 皮尔逊准则对脑磁图源数目进行估计。同时,该方法采用了基于小波的噪声方差估计,实现了脑磁图信号中噪声方差的精确估计。通过对基于信息论方法、主成分分析方法以及该文所提议方法的实验结果的比较,表明该文所提议方法能更准确地估计脑磁图源数目,特别是在源数目较多、信噪比较小的情况下,仍能准确地估计脑磁图源数目,具有较大的实际意义。     

A new method for robust quantitative and qualitative analysis of real-time PCR

An automated data analysis method for real-time PCR needs to exhibit robustness to the factors that routinely impact the measurement and analysis of real-time PCR data. Robust analysis is paramount to providing the same interpretation for results regardless of the skill of the operator performing or reviewing the work. We present a new method for analysis of real-time PCR data, the maxRatio method, which identifies a consistent point within or very near the exponential region of the PCR signal without requiring user intervention. Compared to other analytical techniques that generate only a cycle number, maxRatio generates several measurements of amplification including cycle numbers and relative measures of amplification efficiency and curve shape. By using these values, the maxRatio method can make highly reliable reactive/nonreactive determination along with quantitative evaluation. Application of the maxRatio method to the analysis of quantitative and qualitative real-time PCR assays is shown along with examples of method robustness to, and detection of, amplification response anomalies.     

The generalized torque approach for analyzing the results of pedaling tests

This paper deals with the analysis of experimental data obtained using an ergometer apparatus. A straightforward analysis method based on the power equation and the concept of generalized torques is presented. This method makes it possible to study the influence of the net muscle joint torques and gravity and inertia forces on the crank torque. The assumptions and limitations of the proposed method are discussed and this method is compared with the methods of analysis proposed by other researchers. In order to assess the validity of the method, some experimental data are elaborated. Results show that the method can highlight the effect of training and the pedaling technique of an athlete.     

MTT法检测细菌细胞数的主要影响因素分析

MTT法是生物活细胞计数的灵敏、快速和便捷方法。报告对MTT法应用于细菌细胞数定量分析时的分析前培养时间、MTT反应时间、MTT剂量和检测波长等主要影响因素的分析结果,同时报告MTT反应产物溶解检测与直接检测,以及MTT法与平板菌落计数法定量检测的结果比较。结果如下：Formazan生成量与细菌活细胞数呈正相关,对数生长期变化最明显;MTT为0.25 mg/mL,反应2 h时吸光值与菌落数具有良好的线性关系（r=0.999 8）;Formazan的最大吸收波长为570～580 nm;MTT反应产物溶解检测和直接检测结果经统计学分析无显著性差异（P〉0.05）;细菌细胞数在107～109 cfu/mL范围内,MTT法与菌落计数法定量结果呈现良好的线性关系（r≥0.991 7）。     

The use of image analysis for morphological measurements on filamentous microorganisms

Characterization of mycelial morphology is important for the design and operation of filamentous fermentations. Initial investigations have been made of semiautomated image analysis as a replacement for a digitizing-table method. It was shown that the image analysis method was more precise than the digitizing-table method used, although this extra precision is unimportant in this application. On average, image analysis gave mean hyphal lengths 6% greater than digitizing, because the latter used chord lengths to represent are lengths. For short branches image analysis was less accurate. In time and convenience the image analysis method had an overwhelming advantage, and this advantage might be enhanced by full automation. The resulting ability to characterize mycelial morphology rapidly would permit such characterization to be used routinely in studies of filamentous fermentations.     

Determination of plant species cover by means of image analysis

Abstract. A method is described for the determination of plant species cover in herbaceous plant communities by means of image analysis. It is a computerized extension of the quadrat-charting method. The method was tested with four different computer systems for three different vegetation types, a shady lawn, a pioneer vegetation and a forest floor. We compared the results with vertical point-intercept analyses of the same stands. Image analysis revealed a high accuracy of the method ranging from < ± 1 to about ± 2% cover depending on the dominance of the species being analysed. The method is particularly suitable for the analysis of low herbaceous or unsaturated vegetation, dominance stands of broad-leaved plant species and for the analysis of cover changes in permanent plots.     

Analysis of ligand-receptor binding by the difference method

A new method has been proposed for analysis of experimental data on ligand-receptor binding at equilibrium. This method makes it possible to detect heterogeneity of a receptor system in cases where the contribution of the high-affinity site to total binding is rather small and the problem of graphic discrimination of a model cannot be solved unambiguously by other methods. The difference method permits us to exclude experiments on measuring nonspecific binding. A computer program for analysis of ligand-receptor binding has been worked out in which the difference method and traditional methods of binding isotherm analysis are realized. Numerical modeling has shown that the best strategy in experimental data processing is the treatment of total binding isotherms by both the difference method and regression analysis, including the nonspecific binding constant as one of the regression parameters.     

混合家系遗传参数估计方法研究

针对混合家系遗传参数估计,本文在假定公畜方差组分和母畜方差组分相等这一理论基础上,通过对方差分析的期望均方组成分析,提出了新的遗传力估计方法,以及某些特殊情况下的近似估计方法。通过一个估测实例比较了几种遗传力估计方法,结果表明,本文方法与全同胞组分估计最为接近,而且遗传力标准误最小,本文近似估计方法的效果也较好。对各种方法而言,资料越不平衡其差异越大。本文方法可以在一定程度上弥补全同胞分析时,因实际资料的公母畜方差组分差异过大的缺陷,具有实际可行性。此外,由于本文方法是用单因方差分析解决二因方差分析问题,计算更为简便,并可免于计算混合家系平均亲缘相关系数。     

Incorporating single-locus tests into haplotype cladistic analysis in case-control studies

In case-control studies, genetic associations for complex diseases may be probed either with single-locus tests or with haplotype-based tests. Although there are different views on the relative merits and preferences of the two test strategies, haplotype-based analyses are generally believed to be more powerful to detect genes with modest effects. However, a main drawback of haplotype-based association tests is the large number of distinct haplotypes, which increases the degrees of freedom for corresponding test statistics and thus reduces the statistical power. To decrease the degrees of freedom and enhance the efficiency and power of haplotype analysis, we propose an improved haplotype clustering method that is based on the haplotype cladistic analysis developed by Durrant et al. In our method, we attempt to combine the strengths of single-locus analysis and haplotype-based analysis into one single test framework. Novel in our method is that we develop a more informative haplotype similarity measurement by using p-values obtained from single-locus association tests to construct a measure of weight, which to some extent incorporates the information of disease outcomes. The weights are then used in computation of similarity measures to construct distance metrics between haplotype pairs in haplotype cladistic analysis. To assess our proposed new method, we performed simulation analyses to compare the relative performances of (1) conventional haplotype-based analysis using original haplotype, (2) single-locus allele-based analysis, (3) original haplotype cladistic analysis (CLADHC) by Durrant et al., and (4) our weighted haplotype cladistic analysis method, under different scenarios. Our weighted cladistic analysis method shows an increased statistical power and robustness, compared with the methods of haplotype cladistic analysis, single-locus test, and the traditional haplotype-based analyses. The real data analyses also show that our proposed method has practical significance in the human genetics field.     

Brain signal analysis based on recurrences

The EEG is one of the most commonly used tools in brain research. Though of high relevance in research, the data obtained is very noisy and nonstationary. In the present article we investigate the applicability of a nonlinear data analysis method, the recurrence quantification analysis (RQA), to such data. The method solely rests on the natural property of recurrence which is a phenomenon inherent to complex systems, such as the brain. We show that this method is indeed suitable for the analysis of EEG data and that it might improve contemporary EEG analysis.     

A noncomputerized scanning method for determining relative protein quantities and synthesis rates on two-dimensional electrophoretic gels

A densitometric method that permits the determination of relative amounts and synthesis rates of proteins separated by two-dimensional gel electrophoresis is presented. The method is applicable to proteins that have been stained by Coomassie blue or proteins that have been radiolabeled. The analysis is achieved by scanning selected spots with an ordinary densitometer in the horizontal and vertical direction and relating the response to the volume of an ellipsoid. A linear dependence is observed between the amount of protein or incorporated radioactivity and the measured optical density. The advantage of this method is that specialized scanning instruments and computer analysis are not required. The method is most useful for the analysis of a few specific proteins which change in their relative amount or specific activity due to experimental manipulations. Difficulties in the analysis of protein spots derived from the twodimensional gel electrophoresis technique are discussed and compared to an analysis of bands from the one-dimensional electrophoresis technique.     

Identification of the aph IV gene from protoplast-derived maize plants by a simple nonradioactive DNA hybridization method

Summary Protoplast-derived, transformed maize plants were evaluated by Southern analysis for the presence of the aph IV gene which codes for resistance to the antibiotic, hygromycin B. This gene was used as a selectable marker for the transformation of maize protoplasts. Southern analysis was performed with fluorescein-labeled probe DNA. A new method for labeling molecular weight markers with fluorescein-N⁶ is presented. The nonradioactive Southern analysis method is compared to the radioactive method and the results show that the nonradioactive method is as sensitive as the radioactive method.     

The Use of Canonical Correlation Analysis in the Investigation of Relationships Between Plant Growth and Environmental Factors

The relationship between environmental factors and growth inImpatiens parviflora was analysed by the method of canonicalcorrelation analysis. The method was able to identify the majorrelationships which had been detected by conventional methodsof analysis. The method was also able to detect relationshipsnot identified by conventional methods. The canonical correlationanalysis also clearly showed that relationships between growthand environment detected at a plant dry weight of 100 mg couldalso be detected at 300 mg despite masking due to ontogeneticdrift and confusion by different patterns of adaptation. Itis concluded that the method of canonical correlation analysisis most useful for the analysis of considerable bodies of datarelating plant growth to environmental factors. Marked effectsof spectral composition on growth and development of both leavesand stems were demonstrated. Different spectral compositioneffects on hypocotyl and internode elongation exist. Impatiens parviflora, growth analysis, canonical correlation analysis, spectral composition, stemelongation     

Determination of the association constants and maximum binding capacities between estradiol and cytosol of the uterus by the least-squares analysis of the Scatchard plot.

The association constants and the binding capacities of association of small molecules with macromolecules have been determined by the tangent analysis, the graphical analysis, and the computer data analysis, by trial and convergence of the Scatchard plot. The analytical method for the calculation of the binding parameters based on the Scatchard plot was derived and the optimum values of the binding parameters were obtained by the least squares calculation based on the analytical method. The errors by the analytical method were smaller than those by the graphical method in the equilibrium system between 3H-estradiol and some cytosols of uterus.     

Comparison of methods for measuring soil microbial activity using cotton strips and a respirometer

In order to develop a method of measuring the level of microbial activity in soil that is suitable for use by farmers, land managers, and other non-scientists, a simple method for determining soil microbial activity was evaluated and compared with two standard techniques. Soils sampled from vegetable farms in south east Queensland were incubated in the laboratory under controlled moisture and temperature conditions. Three methods were used to measure soil microbial activity, a respirometry method and two methods using the cotton strip assay (CSA) technique (image analysis and tensometer). The standard CSA method measured loss of tensile strength over a 35 day incubation period of buried cotton strips using a tensometer. The new CSA technique measured the intensity of staining by microbes using a flatbed scanner to create an image of the cotton strip whose staining percentage was determined using Photoshop software. The respirometry method used the substrate induced respiration rate (SIR) to determine microbial biomass in the soil at day 12 of incubation. The strong correlation between the image analysis method and the tensometer method (r(2)=0.81), a technique used by scientific researchers, suggests that the image analysis method could be used to monitor aspects of soil biological health by general community land-care groups and farmers. The image analysis method uses equipment which is readily available and, while not strongly correlated with more precise measurements of soil biological activity such as microbial biomass (r(2)=0.26), it can detect gross trends in biological health in a soil monitoring program. The CSA method using image analysis was the cheapest technique to measure soil microbial activity. CSA using image analysis can be a valuable tool in conjunction with other simple indicators of soil physical and chemical health such as slaking and pH to monitor soil amelioration or rehabilitation programs.     

随机配对法在亚高山草甸优势种群格局分析中的应用

随机配对法是植物种群格局分析的主要方法之一,理论上讲它是最好的方法,因为他改进了等级方差法的所有缺点.但该方法还没有在我国研究实践中应用过.本文将随机配对法应用于芦芽山亚高山草甸群落优势种群的格局研究.结果较好地反映了种群的空间特征.该方法分辨力较强,可以揭示各种格局规模.     

Information quantification of empirical mode decomposition and applications to field potentials

The empirical mode decomposition (EMD) method can adaptively decompose a non-stationary time series into a number of amplitude or frequency modulated functions known as intrinsic mode functions. This paper combines the EMD method with information analysis and presents a framework of information-preserving EMD. The enhanced EMD method has been exploited in the analysis of neural recordings. It decomposes a signal and extracts only the most informative oscillations contained in the non-stationary signal. Information analysis has shown that the extracted components retain the information content of the signal. More importantly, a limited number of components reveal the main oscillations presented in the signal and their instantaneous frequencies, which are not often obvious from the original signal. This information-coupled EMD method has been tested on several field potential datasets for the analysis of stimulus coding in visual cortex, from single and multiple channels, and for finding information connectivity among channels. The results demonstrate the usefulness of the method in extracting relevant responses from the recorded signals. An investigation is also conducted on utilizing the Hilbert phase for cases where phase information can further improve information analysis and stimulus discrimination. The components of the proposed method have been integrated into a toolbox and the initial implementation is also described.