Child Mortality and Socioeconomic Status: An Examination of Differentials by Migration Status in South Africa1

This study examines child mortality and socioeconomic status among migrants and nonmigrants. It also examines child mortality by migration status in all quintiles of socioeconomic status, comparing immigrants to the native‐born and internal migrants to nonmigrants. The results show that among migrants, child mortality decreased faster as socioeconomic status increased than among nonmigrants. The results also show a cross‐over in the likelihood of child mortality by immigration status as socioeconomic status increased. In the poorest socioeconomic quintiles immigrants had a greater likelihood of child mortality than the native‐born while in the wealthiest quintiles child mortality was greater among the native‐born.     

Estimating Contaminant Dose for Intermittent Dermal Contact: Model Development, Testing, and Application

Assessments of aggregate exposure to pesticides and other surface contamination in residential environments are often driven by assumptions about dermal contacts. Accurately predicting cumulative doses from realistic skin contact scenarios requires characterization of exposure scenarios, skin surface loading and unloading rates, and contaminant movement through the epidermis. In this article we (1) develop and test a finite-difference model of contaminant transport through the epidermis; (2) develop archetypal exposure scenarios based on behavioral data to estimate characteristic loading and unloading rates; and (3) quantify 24-hour accumulation below the epidermis by applying a Monte Carlo simulation of these archetypal exposure scenarios. The numerical model, called Transient Transport through the epiDERMis (TTDERM), allows us to account for variable exposure times and time between exposures, temporal and spatial variations in skin and compound properties, and uncertainty in model parameters. Using TTDERM we investigate the use of a macro-activity parameter (cumulative contact time) for predicting daily (24-hour) integrated uptake of pesticides during complex exposure scenarios. For characteristic child behaviors and hand loading and unloading rates, we find that a power law represents the relationship between cumulative contact time and cumulative mass transport through the skin. With almost no loss of reliability, this simple relationship can be used in place of the more complex micro-activity simulations that require activity data on one- to five-minute intervals. The methods developed in this study can be used to guide dermal exposure model refinements and exposure measurement study design.     

Markov bridges and enlarged filtrations

The semimartingale decomposition of a Markov chain, whose value at some future time is known, is obtained by considering an enlarged filtration.     

Autonomy,diversity, and dissent: Conceptions of power and sources of action in the Sejarah Melayu (Raffles MS 18)

This study is concerned with exploring pre-colonial Malay ideas about power— about relationships between people and those who sought authority over them — and about the sources of social action and identity in pre-colonial Malay political culture. It examines, as its principal source for information about these issues, the Sejarah Melayu (Raffles MS 18), identifying significant instances in the text of dissent and of pluralism in Malay political culture.     

Perception of Multisensory Gender Coherence in 6‐ and 9‐Month‐Old Infants

One of the most salient social categories conveyed by human faces and voices is gender. We investigated the developmental emergence of the ability to perceive the coherence of auditory and visual attributes of gender in 6‐ and 9‐month‐old infants. Infants viewed two side‐by‐side video clips of a man and a woman singing a nursery rhyme and heard a synchronous male or female sound track. Results showed that 6‐month‐old infants did not match the audible and visible attributes of gender, and 9‐month‐old infants matched only female faces and voices. These findings indicate that the ability to perceive the multisensory coherence of gender emerges relatively late in infancy and that it reflects the greater experience that most infants have with female faces and voices.     

Factors Associated With Substance Use Disorders Among Traumatized Homeless Youth

This study aimed to identify homeless youths’ lifestyle and trauma-related risk factors as well as protective factors associated with alcohol use disorder or no disorder and drug use disorder or no disorder. Youth receiving homeless services in Denver (n = 201), Austin (n = 200), and Los Angeles (n = 200; N = 601) completed quantitative interviews assessing demographic information, alcohol and drug use, homeless lifestyle risk factors, trauma-related risk factors, and protective factors. Findings showed differences in trauma-related risk factors between alcohol and drug use disorders, but not homeless lifestyle risks. Protective factors predicted substance use disorders beyond risk factors. Understanding trauma-related risk and protective factors associated with substance use disorders could improve interventions.