An index of maternal and child health in the least developed countries of Asia

In this article, we propose a new index to measure maternal and child health in the least developed countries (LDCs) of Asia. This new index is applied to a group of countries particularly affected by poverty, which, in the terminology of the United Nations' Conference on Trade and Development, are the poorest of the poor. Our index has been designed by including the variables defined in the Goals of the Millennium Declaration. For this purpose, we used the P(2) distance method for 2008, the last year for which data were available. This index integrates variables of maternal and child health that allow territorial ordering of the LDCs in terms of these partial indicators. This analysis is particularly useful in a scenario such as the LDCs of Asia, which are beset by profound social and economic inequalities.     

Simultaneous backscatter and attenuation estimation using a least squares method with constraints

Backscatter and attenuation variations are essential contrast mechanisms in ultrasound B-mode imaging. Emerging quantitative ultrasound methods extract and display absolute values of these tissue properties. However, in clinical applications, backscatter and attenuation parameters sometimes are not easily measured because of tissues inhomogeneities above the region-of-interest (ROI). We describe a least squares method (LSM) that fits the echo signal power spectra from a ROI to a three-parameter tissue model that simultaneously yields estimates of attenuation losses and backscatter coefficients. To test the method, tissue-mimicking phantoms with backscatter and attenuation contrast as well as uniform phantoms were scanned with linear array transducers on a Siemens S2000. Attenuation and backscatter coefficients estimated by the LSM were compared with those derived using a reference phantom method (Yao et al. 1990). Results show that the LSM yields effective attenuation coefficients for uniform phantoms comparable to values derived using the reference phantom method. For layered phantoms exhibiting nonuniform backscatter, the LSM resulted in smaller attenuation estimation errors than the reference phantom method. Backscatter coefficients derived using the LSM were in excellent agreement with values obtained from laboratory measurements on test samples and with theory. The LSM is more immune to depth-dependent backscatter changes than commonly used reference phantom methods.     

George Chi's Discussion of the “Executive Summary of the PhRMA Working Group on Adaptive Designs in Clinical Drug Development” By Christy Chuang-Stein,Vladimir Dragalin,Brenda Gaydos,Michael Krams,and José Pinheiro

This paper discusses the selection of an appropriate statistical model for representing standard curve in assay development. This is an important issue in assay validation because the accuracy and reliability of the assay result depend on the selected standard curve. In this study, we propose a selection procedure, which is based on the R ² and the mean squared error of the estimation sample, to determine the “best” model. An example concerning an assay validation study is used to illustrate the application of the proposed procedure to discriminate among the five commonly used statistical models.     

Lonicera japonica Thunb.: ethnopharmacology, phytochemistry and pharmacology of an important traditional Chinese medicine

Ethnopharmacological relevance

Lonicera japonica Thunb. (Caprifoliaceae), a widely used traditional Chinese medicine, was known as Jin Yin Hua (Chinese: ), Ren Dong and Japanese honeysuckle. It was taken to treat the exopathogenic wind-heat, epidemic febrile diseases, sores, carbuncles and some infectious diseases. At the same time, Lonicera japonica could be used as healthy food, cosmetics, ornamental groundcover, and so on.

Aim of the review

The present paper reviewed the ethnopharmacology, the biological activities, toxicology and phytochemistry of Lonicera japonica.

Materials and methods

Information on Lonicera japonica was gathered via the Internet (using Google Scholar, Baidu Scholar, Elsevier, ACS, Medline Plus, CNKI and Web of Science) and libraries. Additionally, information also was obtained from some local books and brilliant scholars on ethnopharmacology.

Results

More than 140 chemical compounds have been isolated, and the main compositions are essential oils, organic acids and flavones, etc. Lonicera japonica and its active principles possess wide pharmacological actions, such as anti-inflammatory, antibacterial, antiviral, antioxidative and hepatoprotective activities.

Conclusions

As an important traditional Chinese medicine, further studies on Lonicera japonica can lead to the development of new drugs and therapeutics for various diseases, and how to utilize it better should be paid more attentions.     

基于遗传算法的威布尔溶出曲线参数估算方法研究

目的:利用遗传算法全局搜索能力的优势,进行威布尔溶出曲线参数估算。方法:以通脉丸中竹节香附素A的溶出数据为研究载体,利用Matlab软件中遗传算法优化工具箱实现威布尔溶出曲线参数估算,并与非线性最小二乘法估算结果进行统计学比较。结果:遗传算法与非线性最小二乘法估算的威布尔溶出曲线参数无显著性差异(P>0.05),而遗传算法估算参数的校正均方差小于非线性最小二乘法。结论:遗传算法适用于威布尔溶出曲线参数的估算。     

Subspace-based support vector machines for pattern classification

In this paper, we discuss subspace-based support vector machines (SS–SVMs), in which an input vector is classified into the class with the maximum similarity. Namely, for each class we define the weighted similarity measure using the vectors called dictionaries that represent the class, and optimize the weights so that the margin between classes is maximized. Because the similarity measure is defined for each class, for a data sample the similarity measure to which the data sample belongs needs to be the largest among all the similarity measures. Introducing slack variables, we define these constraints either by equality constraints or inequality constraints. As a result we obtain subspace-based least squares SVMs (SSLS–SVMs) and subspace-based linear programming SVMs (SSLP–SVMs). To speedup training of SSLS–SVMs, which are similar to LS–SVMs by all-at-once formulation, we also propose SSLS–SVMs by one-against-all formulation, which optimize each similarity measure separately. Using two-class problems, we clarify the difference of SSLS–SVMs and SSLP–SVMs and evaluate the effectiveness of the proposed methods over the conventional methods with equal weights and with weights equal to eigenvalues.     

辐射检测仪器时间常数的测量与探讨

目的 测定4种常用辐射检测仪器（6150AD6+6150AD-b型剂量仪、FH40G+FHZ672E-10型剂量仪、451P型电离室剂量仪和AT1123型剂量仪）的时间常数,探讨时间响应修正公式及应用。方法 在X射线机连续出束条件下,记录仪器显示的周围剂量当量率;根据电阻R电容C串联电路（RC电路）的时间响应修正公式对数据进行最小二乘法拟合,求出仪器的时间常数τ。结果 6150AD6+6150AD-b型剂量仪2次拟合的时间常数τ相对不确定度为8%,其他类型设备2次拟合时间常数τ相对不确定度均>20%。结论 6150AD6+6150AD-b型剂量仪、451P型电离室剂量仪、FH40G+FHZ672E-10型剂量仪和AT1123型剂量仪读数稳定所需时间分别为8、5、3和2 s,其上升趋势不完全符合RC电路时间响应修正公式。     

一元回归的影响分析

传统的最小二乘法对每个数据都给以相等的权重,因此,当数据中存在异常点、高杠杆点与强影响点时,回归方程的“稳健性”往往受到影响。本文就一元回归分析中这些点的探查与处理,结合实例予以讨论。     

简易判别分析

简易判别分析是以原始数据为基础进行判别分析,本方法的关键在于用黄金分割法确定每个变量在不同类别间的最佳分割点和最小错判数,以获得判定每个变量判别能力大小和变量取舍的最小错判率,进而选用最小错判率较低的一个或几个变量建立有效的判别函数。简易判别分析属准参数统计分析,本方法简便、实用,判别结果合理。     

Online parameter estimation and control of d-tubocurarine-induced muscle relaxation

An existing algorithm designed to control d-tubocurarine-induced muscle relaxation in humans has been evaluated in 38 clinical trials on patients undergoing upper and lower abdominal surgery. The data captured during these trials were used to perform offline analysis of the algorithm reported on here, by which the correct functioning of the algorthm was established and its efficacy rated. It is shown that, for practical purposes, the average controller performance is close to the theoretical limit which can be achieved for this drug. The use of online parameter estimation makes precise initialisation of the controller less critical than would be the case with a fixed control low. In the trials undertaken, an average time of 12 min was needed to reach the chosen set point and excessive overshoot was avoided in every case. With a setpoint for the single twitch response of 20 per cent of the control height, the average drug consumption for the first hour of operation was 0·38 mg kg⁻¹.