Rumors of Mass Poisoning in Biafra

Many rumors of mass poisoning circulated in Biafra during therecent Nigerian civil war. The author describes the conditionsthat bred the rumors and the Biafran customs and beliefs thatshaped them     

Dynamics of buried seed population and seedling cohorts of two dominant weeds in a hill agroecosystem of the humid subtropics of India

Dynamics of the buried seeds and plant population of two dominant weeds, viz.,Emilia sonchifolia (Linn.) DC. andRichardsonia pilosa HBK were studied in the crop fields of Meghalaya, north-east India during radish and maize cropping and intervening fallow periods. The total buried seed population ofR. pilosa was always larger than that ofE. sonchifolia, but the germinable fraction was invariably greater in the latter. A major portion (39–41%) of the viable (germinable+dormant) seed population in both weeds was confined to the surface soil layer (0–5 cm). The viable seed population ofE. sonchifolia peaked during April, while that ofR. pilosa showed two peaks (during August and December). The survival pattern and half-lives of seedling cohorts showed, some differences in the two weed species, but both being summer annuals, their populations behaved in a similar manner by showing higher seedling recruitment (K) and survivorship (p) rates in the summer crop (maize) than in the winter crop (radish). However, the density of plants that could attain adulthood was significantly higher inE. sonchifolia thanR. pilosa which might have resulted in greater seed input of the former to the soil leading to its greater abundance in the crop fields. Supported by the University Grants Commission, New Delhi (Grants No. F. 3-37/87 SR II)     

Migration and Elderly Africans in the United States

Although population movements and migration across national borders have occurred throughout human history, the accelerated pace of human migration from Africa to the United States in recent decades is unprecedented. A distinct phenomenon of this trend is that in addition to young African immigrants, an increasing number of elderly Africans are joining the ranks of immigrants in the United States. This article explores prevailing factors that may explain migration among elderly Africans in late adult life. The article addresses the unique experience of African-born elders as they age in the United States. Implications for policy and practice are also discussed.     

大型工程建设项目组织综合集成模式

针对大型工程项目组织现状,应用系统论和综合集成方法,提出了工程项目组织基本原理图。构建了项目组织的十元组模型和十纬度集成理论,并对维度进行分析和归约。在此基础上,建立了工程项目组织集成的逻辑框架、结构框架、运作机制和运作框架,以及集成的组织中人力资源的配置方案,进而提出了宜组织的概念。最后将其应用于工程项目实践中,验证证实取得较好效果。这一大型工程项目组织综合集成模式同样也适合特大型工程项目的组织构造,具有较强的理论先进性和使用价值。     

Estimation of Parameters of a Mixed Failure Time Distribution Which is a Mixture of Degenerate (Degenerate at Zero) and I. G. Distribution

The problem of estimation of parameters of a mixture of degenerate (at zero) and exponential distribution is considered by Jayade and Prasad (1990). The sampling scheme proposed in it is extended in this paper to a mixture of degenerate and Inverse Gaussian distribution. The Inverse Gaussian distribution is very relevant for studying reliability and life-testing problems. The inverse Gaussian being the first passage time distribution for Wiener process makes it particularly appropriate for failure or reaction time data analysis.     

On Projection‐type Estimators of Multivariate Isotonic Functions

Abstract. Let M be an isotonic real‐valued function on a compact subset of and let be an unconstrained estimator of M. A feasible monotonizing technique is to take the largest (smallest) monotone function that lies below (above) the estimator or any convex combination of these two envelope estimators. When the process is asymptotically equicontinuous for some sequence r_n→∞, we show that these projection‐type estimators are r_n‐equivalent in probability to the original unrestricted estimator. Our first motivating application involves a monotone estimator of the conditional distribution function that has the distributional properties of the local linear regression estimator. Applications also include the estimation of econometric (probability‐weighted moment, quantile) and biometric (mean remaining lifetime) functions.     

Estimating the density of a possibly missing response variable in nonlinear regression

This paper considers linear and nonlinear regression with a response variable that is allowed to be “missing at random”. The only structural assumptions on the distribution of the variables are that the errors have mean zero and are independent of the covariates. The independence assumption is important. It enables us to construct an estimator for the response density that uses all the observed data, in contrast to the usual local smoothing techniques, and which therefore permits a faster rate of convergence. The idea is to write the response density as a convolution integral which can be estimated by an empirical version, with a weighted residual-based kernel estimator plugged in for the error density. For an appropriate class of regression functions, and a suitably chosen bandwidth, this estimator is consistent and converges with the optimal parametric rate n^1/2. Moreover, the estimator is proved to be efficient (in the sense of Hájek and Le Cam) if an efficient estimator is used for the regression parameter.     

南宋巴蜀散文(上)

南宋巴蜀散文作家林立 ,著述颇丰 ,体裁上以奏疏政论为主体 ,内容上以忧国忧民、救亡图存为旨归 ,文风通俗质朴 ,犀利简明 ,沉郁悲愤。字里行间 ,忧心如焚 ,忠心可鉴 ,全面展现了四川乃至全国军民抗击强虏的英雄史、腐败朝廷苟且偷安的衰亡史 ,体现了中国知识分子及广大军民的民族魂、爱国心和亡国痛     

压强和温度对薄膜折射率的影响模型

基于膜分子和气相分子在沉积时竞争的观点,得到压强和温度对薄膜折射率影响的理论模型.模型的研究表明,薄膜折射率随真空压强的增加而降低;并随沉积温度的增加而增加.在不同真空压强和不同沉积温度下制备了氧化锆薄膜,计算了样品的折射率,结果显示的规律和理论模型的规律基本一致.