Adaptive estimation of the conditional cumulative distribution function from current status data

Consider a positive random variable of interest Y depending on a covariate X, and a random observation time T independent of Y given X. Assume that the only knowledge available about Y is its current status at time T  : δ=_I{Y≤T}$\delta ={\mathbb{I}}_{\{Y\le T\}}$ with I$\mathbb{I}$ the indicator function. This paper presents a procedure to estimate the conditional cumulative distribution function F of Y given X   from an independent identically distributed sample of (X,T,δ)$(X,T,\delta )$.     

Dynamic factor models

Summary Factor models can cope with many variables without running into scarce degrees of freedom problems often faced in a regression-based analysis. In this article we review recent work on dynamic factor models that have become popular in macroeconomic policy analysis and forecasting. By means of an empirical application we demonstrate that these models turn out to be usefu in investigating macroeconomic problems.     

Childhood innocence and experience: Memory,discourse and practice

This article examines how childhood innocence is taken up in (92) memories of undergraduate students across four sites in the US and Canada. Drawing from Foucault's theory of discourse, we examine how three themes—innocence as not knowing, innocence as being provided for, and loss of innocence as exposure to adversity—construct childhood as the absence of conflict, which perpetuates the myth of an innocence/experience binary and encourages a deficit perspective of childhood. These findings contribute to teacher education and childhood studies by highlighting the importance of interrogating adult memories in order to disrupt normative assumptions about children.     

Long-term economic consequences for women of delayed childbearing and reduced family size

Using data from the Panel Study of Income Dynamics, this study explored the association among delayed childbearing, completed family size and several measures of the economic well-being of women age 60 and older in 1976. By retirement age women who bore their first child at age 30 or older are significantly better off economically than either average-age childbearers or the childless. Economic well-being also appears to be related to family size among late childbearers. At retirement age the delayed childbearer with only one or two children appears better off than all other women. Thus, late childbearing and small family size appear associated with the highest standard of living for these women. This study also relates the experience of this early cohort of women to that of more recent birth cohorts.     

Vacant land conversion to community gardens: influences on generalist arthropod predators and biocontrol services in urban greenspaces

Due to economic decline and the recent rise in home foreclosure, many U.S. cities are faced with managing large acreages of vacant land. Interest in local food production on this land has the potential to dramatically reshape the composition of greenspace found within urban landscapes. This study examined how the conversion of vacant land to urban gardens and farms influenced arthropod generalist predator populations and their ability to support biocontrol services. We found that the abundance of Coccinellidae and Syrphidae, and the activity density of Carabidae, Formicidae, and Lycosidae were equivalent among vacant lot and urban garden sites. Dolichopodidae abundance and the activity density of Linyphiidae and Opiliones were reduced in urban gardens whereas Anthocoridae abundance and the activity density of Staphylinidae were greater within urban gardens relative to vacant lots. The biocontrol service supplied by generalist predators was measured using sentinel eggs (Helicoverpa zea (Noctuiidae)) and pupae (Sarcophaga bullata (Sarcophagidae) and Musca domestica (Muscidae)). We found no difference in the biocontrol of H. zea eggs or M. domestica pupae among the focal greenspaces. We found no difference in the removal of S. bullata pupae by predators in June 2010, whereas in August 2010 a greater proportion of pupae were removed in urban garden sites relative to vacant lots. Based on these findings, we discuss the potential of the urban landscape to support generalist predators and sustainable urban gardening and farming.     

Empowering Community-Based Programs for Youth Development

This article discusses the need for community-based programs for youth and their families and urges the social work profession to resume its historical leadership in such programs while incorporating recent theory and practice. The authors describe the reasons why social workers abandoned neighborhood-based youth development services, the intended outcomes of such services, and current societal and professional trends that support a revival of social work’s involvement in youth development. They discuss one school of social work’s current participation in a youth agency partnership and examine implications of the suggested revival for social work education. Collaboration among families, schools, diverse community services, agencies, and educators is emphasized.