Twicing Kernels and a Small Bias Property of Semiparametric Estimators

The purpose of this note is to show how semiparametric estimators with a small bias property can be constructed. The small bias property (SBP) of a semiparametric estimator is that its bias converges to zero faster than the pointwise and integrated bias of the nonparametric estimator on which it is based. We show that semiparametric estimators based on twicing kernels have the SBP. We also show that semiparametric estimators where nonparametric kernel estimation does not affect the asymptotic variance have the SBP. In addition we discuss an interpretation of series and sieve estimators as idempotent transformations of the empirical distribution that helps explain the known result that they lead to the SBP. In Monte Carlo experiments we find that estimators with the SBP have mean‐square error that is smaller and less sensitive to bandwidth than those that do not have the SBP.     

The effect of earthworms on roadway-derived Zn deposited as a surface layer in storm water retention basin soils

Increased urban development, including an increase in impervious surfaces has the potential to alter the biogeochemistry of surface systems due to storm water runoff contaminated with potentially toxic trace metals (e.g. Zn, Cu and Pb). A major source for urban metals is dust that accumulates on roadways. This roadway dust is derived from vehicle wear sources and tends to be enriched in trace metals such as Pb, Zn, Cu, Cd, Ni and Cr. This continuous source is then being transported via storm water runoff to receiving systems, such as storm water retention systems, which become important focusing environments for trace metal deposition. The fate of these roadway derived metals and their bioavailability once deposited in these urban ecosystems is not well understood. In this investigation we tested the hypothesis that the distribution and form of surface deposited roadway-derived Zn is a function of earthworm processes and is species dependent. The results of this investigation indicate that roadway dust derived Zn deposited as a surface layer on urban soils is readily removed from the surface in less than 30 days whether earthworms are present or not. However, after 90 days, the presence of earthworms and the life habit of the earthworm species present was found to have a significant impact on the physical and chemical cycling of roadway derived trace metals in storm water retention basin soils.     

Maternal substance abuse and disrupted parenting: Distinguishing mothers who keep their children from those who do not

Women with substance abuse disorders typically have psychosocial characteristics that put them at risk for disrupted parenting. Prior research indicates that comprehensive, accessible services tailored to the mothers' needs can contribute to family stability. This study further explores the complicated interplay of how maternal risk and protective characteristics and service elements are associated with reunification. The study contributes to existing literature by following mothers for three years; examining service needs as identified by the mother herself; using a summary proportion score to reflect the totality of services received to matched service needs identified; and using logistic regression to examine interactions of services received with critical maternal characteristics. The sample is comprised of 458 substance-abusing mothers enrolled during pregnancy or postpartum in the Washington State Parent-Child Assistance Program (PCAP), an evidence-based case management intervention. Participants' custody status was well distributed among four categories based on continuity of parenting. Findings indicate that at program exit 60% of the mothers were caring for their index child. These mothers had more treatment and mental health service needs met, had more time abstinent from alcohol and drugs, secure housing, higher income, and support for staying clean and sober. Among women with multiple psychiatric diagnoses, the odds of regaining custody were increased when they completed substance abuse treatment and also had a supportive partner. Mothers who lost and did not regain custody had more serious psychiatric problems and had fewer service needs met. We discuss implications of our findings for child welfare policy and practices.     

A population-based inquiry of homeless episode characteristics and early educational well-being

Child homelessness and educational well-being is an area of national research that requires more precise investigation to address mixed findings. The aim of this study was to extend the investigation of the relations between homelessness and educational well-being by determining if timing and frequency of homeless episodes are differentially associated with children's academic and classroom engagement outcomes. This investigation used a comprehensive research model to study the effects of these homeless episode characteristics within a large urban student cohort. Additionally, this study accounted for co-occurring early risk factors. Findings indicated that having a first homeless episode in early childhood was associated with non-proficiency in mathematics and academic engagement problems. Also more frequent homeless episodes were related to truancy in third grade. These results stress the importance of early intervention for homeless children and underscore the need to further understand the variation in young children's homeless experiences.     

The Dangerous Real: Queer Solo Performance in/as Active Disruption

Abstract

Like all radical community endeavours, queer performance in the United States has been shaped through resistance to restrictive ideologies. National insecurity over ‘indecent’ (read: queer) artistic expression in the US has been aimed at artists working in a variety of genres, and here I focus specifically on queer solo performance artists. This essay explores the dangerous realities that queer artists present to an imagined unified US national identity. I argue that queer solo performers operate as artistic activists, challenging homogenous fantasies about US culture through the queering of experience. Aesthetically disparate, their work is connected by common threads of vulnerability and precarity. The article asks how their work disrupts U.S. insecurities concerning intersections of sexuality, gender identity, race and religion.     

Earthquake Beliefs and Adoption of Seismic Hazard Adjustments

This study investigated the prevalence of both accurate and erroneous earthquake-related beliefs among a sample of Southern California college students and the relationship between their endorsement of earthquake beliefs and adoption of seismic hazard adjustments. In addition, the study examined the effects of an experimental earthquake education program and the impact of need for cognition on this program. The data revealed a significant degree of agreement with earthquake myths, a generally low level of correlation between earthquake beliefs and the level of hazard adjustments, and a significant effect of hazard information on the endorsement of accurate earthquake beliefs and increases in hazard adjustment. Compared with the "Earthquake Facts (Only)" format, an "Earthquake Myths versus Facts" format was slightly more useful for dispelling erroneous beliefs. Further, there was a tendency for those who were high in need for cognition to have higher levels of hazard adjustment. Finally, there was weak support for the hypothesis that those who were low in need for cognition would develop more accurate earthquake beliefs and higher levels of hazard adjustment in the "Earthquake Myths versus Facts" information condition.     

The acuity of echolocation: Spatial resolution in the sighted compared to expert performance

Compared with the echolocation performance of a blind expert, sighted novices rapidly learned size and position discrimination with surprising precision. We use a novel task to characterize the population distribution of echolocation skill in the sighted and report the highest known human echolocation acuity in our expert subject.     

Going Back Part-time: Family Leave Legislation and Women’s Return to Work

Using a multinomial logit model with data from the Survey of Income and Program Participation, this paper tests whether the implementation of the Family and Medical Leave Act (FMLA) is associated with an increase in return to work at part-time status among first-time mothers working full-time during their pregnancy. I find a statistically significant trend of increasingly higher odds of returning to work at part-time status relative to return at full-time status, beginning in 1993 (the year in which the FMLA is implemented). Furthermore, an additional week of either state or federal leave is significantly associated with a higher odds of return at part-time status. This article provides evidence that job protection and leave legislation may help facilitate higher levels of labor force participation among women with small children, through more flexible work arrangements.