Dynamic gait stability index based on plantar pressures and fuzzy logic

Stability during locomotion, or dynamic stability, is critical to ensure safe locomotion and a high quality of life. A dynamic stability measure should be easily applied in a clinical setting and must provide a quantitative index that can be used for comparisons over a range of tasks and environments. Plantar foot pressure data acquired by shoe-insole sensors have potential to provide such a measure. To generate a quantitative dynamic gait stability index, six gait parameters were extracted from a commercial plantar pressure measurement system (F-Scan): anterior–posterior (A/P) center of force (CoF) motion, medial–lateral (M/L) CoF motion, maximum lateral position, cell triggering, stride time (ST), and double support time (DST). A fuzzy logic controller combined these six parameters and generated the index. To validate the stability index, 15 healthy subjects performed four tasks intended to induce increasing levels of instability. Fifty-seven gait parameter combinations were assessed to determine the most effective index. A combination of A/P motion, M/L motion, maximum lateral position, and cell triggering parameters was the most consistently effective index across all subjects. However, small changes in ST and DST for able-bodied subjects may have reduced the effectiveness of these measures in the index calculation. The index combining all six parameters should be investigated further with populations with disabilities or pathological gait.     

Retrospective approach to investigating the early life history of a diadromous fish: allis shad Alosa alosa (L.) in the Gironde–Garonne–Dordogne watershed

In this study, the identification of major ontogenetic events and the duration of the fresh water and estuarine phases before the seaward exit of young allis shad Alosa alosa were investigated retrospectively, using the otoliths of spawners. Daily growth increment periodicity in the otoliths was validated with an accuracy of 4 days (9·4%) for fish >30 days. The specific limits of the Sr:Ca ratios in the otoliths, indicating fish movements between salinity 'compartments', were up to 1·1 ×10⁻³ for the freshwater phase, 1·1 to 1·9 × 10⁻³ for the estuarine phase and 1·9 × 10⁻³ for the marine phase. In early life history, a major event occured at 22 days, which was marked on the otoliths by a change in the direction of the otolith growth axis. This event was related to a change in larval swimming behaviour. Juvenile freshwater residence time was between 58 and 123 days, with a median duration of 88 days. Contrary to what has been estimated in previous studies, the present study showed that the estuarine phase lasted from 4 to 36 days, with a median value of 11 days. Seaward exit occurred in fish aged from 63 to 150 days, with a median age of 99 days. These results have important implications for the sustainable management of this species.     

长白山阔叶红松林的零平面位移和粗糙度

根据长白山阔叶红松林气象观测塔上 16个月的风速、温度、湿度及气压的连续观测资料 ,根据中性层结条件下风速随高度的对数变化规律 ,利用廓线法中的牛顿迭代法计算了该森林的零平面位移d和粗糙度z0 ,结果表明 ,d和z0 均存在着较明显的季节变化 ,在生长季d较大 ,z0 较小 ,而非生长季恰好相反 ,标准化的零平面位移d/h和粗糙度z0 /h在生长季和非生长季平均分别为 0 86 7,0 76 4和 4 4 7× 10 -2 ,3 5 9× 10 -2 。与叶面积指数对比分析发现 ,d/h和z0 /h与叶面积指数分别存在正相关和负相关的关系。敏感性分析表明 ,牛顿迭代法求d和z0对风速的精度要求较高 ,需要精度高的仪器和长期的数据积累。     

我国西部地区两个重要生态功能保护区建设的要点分析

分析了我国西部两个重要生态功能区———黄河源生态功能保护区和塔里木河流域生态功能保护区建设中应把握的要点。强调了生态系统的多视角描述方法 ,分析了两个重要生态功能区存在的生态环境问题和引起生态环境退化的可能原因 ,确定了两个生态功能区的主导生态功能 ,并对生态功能保护区建设提出了建议     

A Simulation-Assessment Modeling Approach for Analyzing Environmental Risks of Groundwater Contamination at Waste Landfill Sites

An integrated simulation-assessment modeling approach for analyzing environmental risks of groundwater contamination is proposed in this paper. It incorporates an analytical groundwater solute transport model, an exposure dose model, and a fuzzy risk assessment model within a general framework. The transport model is used for predicting contaminant concentrations in subsurface, and the exposure dose model is used for calculating contaminant ingestion during the exposure period under given exposure pathways. Both models are solved through the Monte Carlo simulation technique to reflect the associated uncertainties. Based on consideration of fuzzy relationships between exposure doses and cancer risks, risk levels of different exposure doses for each contaminant can be calculated to form a fuzzy relation matrix. The overall risks can then be quantified through further fuzzy synthesizing operations. Thus, probabilistic quantification of different risk levels (possibilities) can be realized. Results of the case study indicate that environmental risks at the waste landfill site can be effectively analyzed through the developed methodology. They are useful for supporting the related risk-management and remediation decisions.     

Multiple genetic variants along candidate pathways influence plasma high-density lipoprotein cholesterol concentrations

The known genetic variants determining plasma HDL cholesterol (HDL-C) levels explain only part of its variation. Three hundred eighty-four single nucleotide polymorphisms (SNPs) across 251 genes based on pathways potentially relevant to HDL-C metabolism were selected and genotyped in 3,575 subjects from the Doetinchem cohort, which was examined thrice over 11 years. Three hundred fifty-three SNPs in 239 genes passed the quality-control criteria. Seven SNPs [rs1800777 and rs5882 in cholesteryl ester transfer protein (CETP); rs3208305, rs328, and rs268 in LPL; rs1800588 in LIPC; rs2229741 in NRIP1] were associated with plasma HDL-C levels with false discovery rate (FDR) adjusted q values (FDR_q) < 0.05. Five other SNPs (rs17585739 in SC4MOL, rs11066322 in PTPN11, rs4961 in ADD1, rs6060717 near SCAND1, and rs3213451 in MBTPS2 in women) were associated with plasma HDL-C levels with FDR_q between 0.05 and 0.2. Two less well replicated associations (rs3135506 in APOA5 and rs1800961 in HNF4A) known from the literature were also observed, but their significance disappeared after adjustment for multiple testing (P = 0.008, FDR_q = 0.221 for rs3135506; P = 0.018, FDR_q = 0.338 for rs1800961, respectively). In addition to replication of previous results for candidate genes (CETP, LPL, LIPC, HNF4A, and APOA5), we found interesting new candidate SNPs (rs2229741 in NRIP1, rs3213451 in MBTPS2, rs17585739 in SC4MOL, rs11066322 in PTPN11, rs4961 in ADD1, and rs6060717 near SCAND1) for plasma HDL-C levels that should be evaluated further.     

Interval estimation of the mean difference in the analysis of over‐dispersed count data

This paper focuses on the development and study of the confidence interval procedures for mean difference between two treatments in the analysis of over‐dispersed count data in order to measure the efficacy of the experimental treatment over the standard treatment in clinical trials. In this study, two simple methods are proposed. One is based on a sandwich estimator of the variance of the regression estimator using the generalized estimating equations (GEEs) approach of Zeger and Liang (1986) and the other is based on an estimator of the variance of a ratio estimator (1977). We also develop three other procedures following the procedures studied by Newcombe (1998) and the procedure studied by Beal (1987). As assessed by Monte Carlo simulations, all the procedures have reasonably well coverage properties. Moreover, the interval procedure based on GEEs outperforms other interval procedures in the sense that it maintains the coverage very close to the nominal coverage level and that it has the shortest interval length, a satisfactory location property, and a very simple form, which can be easily implemented in the applied fields. Illustrative applications in the biological studies for these confidence interval procedures are also presented.     

Assessment of river health based on an improved entropy-based fuzzy matter-element model in the Taihu Plain,China

Rivers are valuable to human beings because of their various functions. Unfortunately, ecological integrity of rivers has been seriously threatened by human activities, resulting in poor river functions. It is thus necessary to evaluate and maintain river health. Meanwhile, it is challenging to comprehensively assess river health with a single method alone. It is therefore relevant to combine the advantages of multiple methods in river health assessment. By classifying and characterizing river functions, we first established an indicator system for river health assessment in plain river network regions. We then assessed the health status of the Taihu Plain in terms of an improved entropy-based fuzzy matter-element model. We found that the overall health status of the Taihu Plain is below “good”. In particular, the health status of Yang-Cheng-Dian-Mao and Hang-Jia-Hu Region is “moderate”; the Wu-Cheng-Xi-Yu Region displays the poorest natural and social river functions. We also found that flood control is the most important influential factor in river health. Our findings suggest that rivers in the Taihu Plain must be restored to maintain their health, with the Wu-Cheng-Xi-Yu Region that must be restored preferentially, and that the river function of flood control must be improved at the scale of whole watershed. Comparing with other four commonly used comprehensive assessment methods, our improved entropy-based fuzzy matter-element model outperforms in reflecting objective fact and can be applied to river health assessment. Our results are generally consistent with existing studies, confirming that the proposed method for river health assessment is effective and feasible. Therefore, it provides a useful reference for river health assessment in other plain river network regions.