Do perceptions of their partners’ childbearing desires affect young women’s pregnancy risk? Further study of ambivalence

We explore whether young women’s perceptions of their sexual partners’ childbearing desires contribute to their risk of pregnancy. We used weekly journal data collected from 787 young women to measure their childbearing desires and their perceptions of their partners’ childbearing desires. We then conducted hazard modelling to predict pregnancy risk with variables based on interactions between the women’s desires and their perceived partners’ desires. Models that include perceived partners’ desires perform better than one based on women’s desires alone. The best model contains three significant predictors: one confirms the importance of pronatal, ambivalent, and indifferent desires for pregnancy risk; one indicates that the perceived partners’ antinatal desires reduce women’s pregnancy risk; and one suggests that women who both perceive their partners accurately and are in agreement with them have a lower pregnancy risk. The results indicate that perceived partner data can improve prediction and enhance our understanding of pregnancy risk.     

基于步进电机控制的伺服钻孔机设计

采用高性能的STC89C516RD+单片机,控制步进电机完成点动、快进、工进以及精确定位的任务。定位系统是通过设定原点和精确控制脉冲数来实现的。解决了钻头在刚性材料表面上不能精确定位以及金属屑不易排出去的难题。与传统的手动钻孔机相比,该伺服钻孔机控制方便、精度高、生产效率高。     

Unraveling the Source of African American Children's Positively Biased Perceptions of Peer Acceptance

The present study investigated possible ethnic contributions to overly positive self‐perceptions in middle childhood. The goals of this study were threefold. First, the present study sought to replicate the intriguing findings reported by Zakriski and Coie that African American children overestimate their acceptance, and European American children underestimate acceptance by other‐ethnicity peers. Second, this study examined possible explanations for ethnic differences in the pattern of perceptual bias. Finally, this study extended prior research by examining ethnic differences in the accuracy of children's perceived peer acceptance. Archival data consisting of 826 children in third (N = 284), fourth (N = 241), and fifth grades (N = 301) were used in the present investigation; 237 of which were African American children, and 589 were European American children. Results of this study replicated the findings of Zakriski and Coie . Moreover, African Americans' overestimation and European Americans' underestimation of acceptance by other‐ethnicity peers was found to be attributable to more positive views of self and others among African American children relative to European American children. Finally, children were found to be more accurate about judging their acceptance by peers of the same ethnicity than those of a different ethnicity. Possible explanations of what causes African American children to have more positive views of self and others than European American children are discussed.     

江浦县1:5万30m空间分辨率DEM的制作

本文主要介绍了建立在G IS软件的基础上,以江浦县为例,利用1:5万的国家基本地形图作为基础底图资料,根据国家DEM的制作精度要求,制作1:5万、30m空间分辨率数字高程模型(DEM)的方法及过程。同时对生成的DEM做了精度和质量上的检验。     

Brief Report: Thin Slices of Racial Bias

The present work examined the detection of racial bias through thin slices of nonverbal behavior. Thirty Black and 30 White American judges rated the nonverbal behavior displayed by White individuals from 20-seconds of silent videotape of an interaction with either a Black or a White confederate. Correlations between judges nonverbal ratings and targets scores on a response latency measure of racial bias (i.e., Implicit Association Test, IAT) as well as on a self-report racial bias measure (i.e., Affective Prejudice Scale) were obtained. Results revealed that relative to White judges, Black judges nonverbal behavioral ratings were better predictors of both White individuals IAT and explicit racial bias scores, but only if those targets were engaged in an interracial dyad. The results are consistent with recent research finding that subtle forms of racial bias leak through nonverbal behavior, as well as with work noting the predictive accuracy of judgments made from thin-slices of nonverbal behavior.Jennifer A. Richeson and J. Nicole Shelton. Jennifer A. Richeson, Dartmouth College; J. Nicole Shelton, Princeton University. This research was supported by a Rockefeller Center Faculty Fellowship from Dartmouth College awarded to JR, as well as a research grant from Princeton University awarded to JNS. We thank Sue Paik, Lisa Pugh, Kurt Peters, and Leigh Poretzky for help with data collection and stimulus preparation.     

Status Roles and Recall of Nonverbal Cues

In two experiments, interpersonal status was experimentally manipulated by assigning one dyad member to be the owner of a mock art gallery and the other to be the owner's assistant. Without forewarning, participants were asked immediately following the interaction to recall their partner's hand gestures, self-touch, gazing, smiling, and nodding. Accuracy of recall was determined by comparing these ratings to their partners' behavior as coded from the videotape. In both experiments, assistants were more accurate at recalling the amount of owners' self-touch than vice versa, but there was little evidence of an accuracy difference in recall of the other nonverbal cues. When accuracy was defined as the correlation between a participant's ratings of the partner's behaviors and the partner's actual behaviors, there was evidence that assistants were more accurate than owners when a combined p-value was calculated across both studies.     

On the Optimal Use of Suboptimal Forecasts of Explanatory Variables

Ashley (1983) gave a simple condition for determining when a forecast of an explanatory variable (X_t ) is sufficiently inaccurate that direct replacement of X_t by the forecast yields worse forecasts of the dependent variable than does respecification of the equation to omit X_t . Many available macroeconomic forecasts were shown to be of limited usefulness in direct replacement. Direct replacement, however, is not optimal if the forecast's distribution is known. Here optimal linear forms in commercial forecasts of several macroeconomic variables are obtained by using estimates of their distributions. Although they are an improvement on the raw forecasts (direct replacement), these optimal forms are still too inaccurate to be useful in replacing the actual explanatory variables in forecasting models. The results strongly indicate that optimal forms involving several commercial forecasts will not be very useful either. Thus Ashley's (1983) sufficient condition retains its value in gauging the usefulness of a forecast of an explanatory variable in a forecasting model, even though it focuses on direct replacement.     

SOME RESAMPLING PROCEDURES UNDER SYMMETRY

This paper investigates the properties of bootstrap and related methods assuming that the underlying distribution is symmetric but otherwise unknown. In particular it studies the percentile-t, nonparametric tilting and empirical likelihood and finds that the performance of percentile-t and non-parametric tilting methods can be improved by incorporating the symmetry into the resampling procedure. However, for symmetric empirical likelihood, the Bartlett correctability no longer holds, although use of bootstrap calibration restores the good coverage properties typically associated with Bartlett correction. This surprising result shows that Bartlett correctability is a very delicate property.     

关于误差理论若干基本问题的探讨

本文对于不确定度等若干误差理论中的基本问题进行了探讨,提出了一些新的见解与观点,希望能达到加深对这些问题的理解,统一有关名词术语及其定义,并改善它们的应用之目的。     

测试发音的准确程度--一个必须回归的话题

目前越来越多的EFL教师普遍重视学生的语言交际能力的培养与测试 ,但是却忽视或不重视发音准确程度的测试与评估。尽管这一现象的形成有诸多原因 ,但是发音准确程度的测试与评估却绝对不可忽视或不重视 ,本文以‘听’与‘写’的结合为切入点 ,从测试音素这个角度简要的介绍了几种常用的测试发音准确程度的方法。