Four‐Month‐Olds' Discrimination of Voice Changes in Multimodal Displays as a Function of Discrimination Protocol

Past studies have found equivocal support for the ability of young infants to discriminate infant‐directed (ID) speech information in the presence of auditory‐only versus auditory + visual displays (faces + voices). Generally, younger infants appear to have more difficulty discriminating a change in the vocal properties of ID speech when they are accompanied by faces. Forty 4‐month‐old infants were tested using either an infant‐controlled habituation procedure (Experiment 1) or a fixed‐trial habituation procedure (Experiment 2). The prediction was that the infant‐controlled habituation procedure would be a more sensitive measure of infant attention to complex displays. The results indicated that 4‐month‐old infants discriminated voice changes in dynamic face + voice displays depending on the order in which they were viewed during the infant‐controlled habituation procedure. In contrast, no evidence of discrimination was found in the fixed‐trial procedure. The findings suggest that the selection of experimental methodology plays a significant role in the empirical observations of infant perceptual abilities.     

A Numerical Solution to the Nonhomogeneous Two-Stage MVK Model of Cancer

In this article, we describe a straightforward method for solving the probability of at least one malignant cell by time t, and the associated hazard function, in the general (i.e., nonhomogeneous) two-stage Moolgavkar-Venzon-Knudson (MVK) model of cancer. The method consists of solving four coupled ordinary differential equations derived from the Kolmogorov backward equations for this process. The relationship of this method to previously proposed solutions is discussed.     

Joint impact of multiple observations on a subset of variables in multiple linear regression

In multiple linear regression analysis, each observation affects the fitted regression equation differently and has varying influences on the regression coefficients of the different variables. Chatterjee & Hadi (1988) have proposed some measures such as DSSE_ij (Impact on Residual Sum of Squares of simultaneously omitting the ith observation and the jth variable), F_j (Partial F-test for the jth variable) and F_j(i) (Partial F-test for the jth variable omitting the ith observation) to show the joint impact and the interrelationship that exists among a variable and an observation. In this paper we have proposed more extended form of those measures DSSE_IJ, F_J and F_J(I) to deal with the interrelationships that exist among the multiple observations and a subset of variables by monitoring the effects of the simultaneous omission of multiple variables and multiple observations.     

TOWARD A SYNTHESIS OF FEMINIST AND DEMOGRAPHIC PERSPECTIVES ON FERTILITY

In explaining fertility and reproduction and emerging patterns of childbearing, both demographers and feminists have centered their thinking on women's status (economic and social), women's changing roles and life experiences (increased labor force participation, increased availability of reproductive options, declining marriage rates in many parts of the industrialized world, and the centrality of women to development), and women as agents in micro- and macrolevel changes in family, fertility, and economic change. Although demography has recently begun to integrate feminist perspectives into fertility explanations, there is not yet a synthesis of feminist theoretical insights with demographic questions. Drawing from recent thinking on global and national political and policy challenges in the less and more developed worlds, to the epistemological shifts in knowledge of reproduction/mothering, to changes in the technologies of reproduction, this article moves toward an integration of feminist and demographic perspectives on fertility.
…far from the economic dependence of women working in the interests of motherhood, it is the steadily acting cause of a pathological maternity and a declining birthrate.
Charlotte Perkins Stetson, Women and Economics , 1899     

I'm Telling! The Content, Context, and Consequences of Children's Tattling on their Siblings

Tattling on siblings was observed in 40 families with 2- and 4-year-old children. All but 5 children reported sibling misbehaviour to parents with younger siblings tattling largely to recruit parental help in resolving conflict issues, and older siblings tattling both in the context of conflict and merely to inform parents of their siblings' misbehaviour. Parents rarely reprimanded children for tattling, but either ignored it, or responded to information in tattlers' reports regardless of context or whether older or younger children tattled. Children did not tattle equally on all sibling transgressions, but emphasized physical aggression and property damage, issues that also elicited parental discipline. Tattling is discussed in relation to children's understanding of the dynamics and moral standards of family life.     

Married women's retirement behavior

In this paper we examine the economic and family determinants of married women's retirement behavior. A life cycle model of wives' retirement decisions is tested empirically using data on working married women from the Longitudinal Retirement History Survey. This exploratory analysis indicates that family considerations are more important in wives' retirement decisions than own economic opportunities. These findings contrast with those obtained previously for male workers and if substantiated by other research could have important implications for policy questions regarding pension and Social Security reform.This research was funded by the 1986–7 Small Grants Program sponsored by the University of Wisconsin, Madison, Institute for Research on Poverty, the Cornell Institute of Social and Economic Research, and the New York State School of Industrial and Labor Relations. Excellent programming assistance was provided by Vivian Fields. We are grateful to Glen Cain and two anonymous referees for useful comments. Any opinions expressed herein are those of the authors and not those of the above-named persons or institutions.     

Physician-nurse migration to the United States: regional and health status origins in relation to legislation and policy

This article examines the origins of physicians and nurses who were admitted as permanent immigrants to the US from 1962-1979. Data are mainly from the Immigration and Naturalization Service. Countries used in the developmental analysis are only those whose population was estimated at 1 million or more as of mid-1979, encompassing 99% of the physicians and 97% of the nurses. Life expectancy at birth is the criterion used to differentiate origin countries by developmental dimension of health status. During the study period, health workers constituted about 30% of immigrants admitted to the US; of these, nurses and physicians constituted 72-82% throughout the study period. The period 1962-1979 has 4 distinct phases, marked by important legislative and/or policy changes; 1) 1962-1965, when the McCarran-Walter Act prevailed; 2) ending in 1968, the 2nd phase covers the transition mandated under the 1965 Immigration Act, which encouraged physician immigration; 3) the 3rd phase, 1969-1976, covers the transition to the 1976 Immigration and Nationality Act amendments; and 4) the 4th stage is 1977-1979. Results show that 1) under the McCarran-Walter Act, North America became the dominant physician source; 2) from 1966-1968, Asia attained dominance as the physician source and became even more predominant after 1968; 3) North America produced relatively few physicians in the early 1970s; 4) Europe produced substantially fewer physicians in the 1970s than in the 1960s; 5) South America, Africa, and Oceania were the lowest contributors of physicians; 6) during the McCarran-Walter years, North America and Europe produced almost 90% of nurses admitted into the US; 7) the 1965 Immigration Act and its aftermath resulted in Asia becoming the dominant source of nurses; 8) prior to the 1965 Immigration Act, Canada generated 20% of the aggregate number of physicians; 9) the Philippines surpassed Canada during the transition and India led after the transition; and 10) Canada supplied 30% of the nurses up through the transition, with the Philippines in the lead 1969-1979. Low health status countries were a relatively minor nurse source. Health status at the origin was a far less significant determinant of physician immigration than that of nurses. English language high and low health status country groups produced substantially more physician and nurse immigrants that their corresponding non-English language counterparts. The US attracted more physicians and nurses from less developed countries than more developed countries after 1968.