Prospective Cohort Study of Emergency Department Visit Frequency and Diagnoses Before and During COVID-19 Pandemic in Urban, Low-Income, US- and Foreign-Born Mothers in Boston, MA.

Background: The coronavirus 2019 (COVID-19) pandemic fundamentally changed how populations interface with the healthcare system. Despite historical spikes in US mortality during the pandemic, emergency department (ED) visits were paradoxically low. This is a concerning phenomenon that raises a red flag regarding access to care, especially among vulnerable populations.

Gender difference in "second-shift" physical activity: New insights from analyzing accelerometry data in a nationally representative sample.

The gendered organization of daily activities results in differential contexts of physical activity (PA) for the working population, especially during the "second shift" - a time window dominated by household-based activities. Existing research predominantly relies on self-reported leisure-time activities, yielding a partial understanding of gender difference in the source, timing, and accumulation pattern of PA. To address these limitations, this study draws on the interplay between work and family to understand how they shape gender difference in household-based PA across occupational groups.

Occupational determinants of physical activity at work: Evidence from wearable accelerometer in 2005-2006 NHANES.

Occupation determines workers' physical activity (PA) in the workplace, an important health behavior contributing to health outcomes. However, self-reported measure limits our understanding of how occupational tasks differentiate workers' PA in terms of the type, frequency, intensity, and duration. In addition, accurate estimation of occupation-based PA during workers' actual working hours requires precise work schedule information.

Residential racial segregation and social distancing in the United States during COVID-19.

Background: Our objective is to examine whether residential racial segregation may be constraining capacities for social distancing thus leaving African Americans potentially more exposed to contracting COVID-19. We hypothesized that residential racial segregation constrains African Americans' spatial mobility when the whole population is locked down but increases their need for moving under reopening orders.

Methods: We employ a Black/White dissimilarity index as our independent variable and county-level mobility ratios as our dependent variable.

Adolescents' Patterns of Well-Care Use Over Time: Who Stays Connected.

Introduction: Well-care use can positively impact adolescents' current and future health. Understanding adolescents' longitudinal well-care use is critical to determine to whom and when to target engagement strategies to improve healthcare access. This study describes prospective well-care use patterns from childhood through adolescence stratified by sex.

China's College Expansion and the Timing of College-to-Work Transition: A Natural Experiment.

This paper examines the causal effect of China's 1999 accelerated expansion of higher education on the timing of finding a first skilled job among college graduates. To test hypotheses derived from applying relevant theories to the China case, we use a natural experiment. The analysis exploits the unique education and work history data of a nationally representative survey and estimates a causal inference model.

Genome-wide association study identifies a novel maternal gene × stress interaction associated with spontaneous preterm birth.

Background: Maternal stress is potentially a modifiable risk factor for spontaneous preterm birth (sPTB). However, epidemiologic findings on the maternal stress-sPTB relationship have been inconsistent.

Methods: To investigate whether the maternal stress-sPTB associations may be modified by genetic susceptibility, we performed genome-wide gene × stress interaction analyses in 1490 African-American women from the Boston Birth cohort who delivered term (n = 1033) or preterm (n = 457) infants.

Prenatal, Perinatal, and Early Childhood Factors Associated with Childhood Obstructive Sleep Apnea.

Objectives: To investigate prenatal, perinatal, and early childhood factors, including cord and early childhood plasma leptin, on a clinical diagnosis of obstructive sleep apnea (OSA) among children in the Boston Birth Cohort.

Study Design: We conducted a secondary analysis of 2867 mother-child pairs from the Boston Birth Cohort who were enrolled between 1998 and 2014 at Boston Medical Center and followed from birth to age 16 years. Child's OSA was defined based on clinical diagnoses documented in the medical record.

Maternal postpartum plasma folate status and preterm birth in a high-risk US population.

Objective: While maternal folate deficiency has been linked to poor pregnancy outcomes such as neural tube defects, anaemia and low birth weight, the relationship between folate and preterm birth (PTB) in the context of the US post-folic acid fortification era is inconclusive. We sought to explore the relationship between maternal folate status and PTB and its subtypes, i.e.

Adolescents' and Young Adults' Routine Care Use: The Role of Their Mothers' Care Use Behaviors.

Purpose: Little is known whether mothers' own care use is differentially associated with their adolescents' routine care use by gender. The main purpose of this study is to examine whether mothers' healthcare use prospectively predicts their adolescents' routine care use stratified by gender, after controlling for predisposing (child's age, race/ethnicity, region of residence, urbanicity, and mother's age at child's birth), enabling (mother's education, adolescent and mother health insurance), and need (child health status) factors.

Methods: In 2018, a prospective analysis was conducted using data from 5,040 adolescents aged 9-24 and their mothers who completed the two-generation National Longitudinal Survey of Youth in 2006 (first interview) and 2008 (second interview).

Agent-Based Modeling of China's Rural-Urban Migration and Social Network Structure.

We analyze China's rural-urban migration and endogenous social network structures using agent-based modeling. The agents from census micro data are located in their rural origin with an empirical-estimated prior propensity to move. The population-scale social network is a hybrid one, combining observed family ties and locations of the origin with a parameter space calibrated from census, survey and aggregate data and sampled using a stepwise Latin Hypercube Sampling method.

Uneven Hedging of Economic Risks for a Skilled Workforce: Are Immigrants Disadvantaged?

Skilled immigration to the United States has been multi-channeled via legislations on permanent and temporary visa programs. This paper argues that skilled immigrants were not disadvantaged during the Great Recession because of a new hedging mechanism, which starts with the federal legislations that admit skilled nonimmigrants, proceeds to vest authority in employers, who perform rigorous screening and selection of temporary workers for future permanency, and ends with greater protection of those selected. To test this mechanism, the paper examines skilled immigrants' spatial mobility out of the country and their domestic labor market outcomes.

The Spatial and Career Mobility of China's Urban and Rural Labor Force.

This paper provides a comprehensive examination of the spatial and career mobility of China's labor population. The paper integrates theories on stratification and social change and exploits the innovative design and measurement of the China Labor-force Dynamics Survey to minimize the under-coverage problem of the rural-urban migratory experience. Our analysis provides several fresh findings: (1) at-birth rural household registration (hukou) status leads to a greater probability of spatial mobility and career advancement than at-birth urban hukou status does; (2) education and gender differentiates rural-origin people, increasing the heterogeneity of urban labor and decreasing the heterogeneity of rural labor; (3) hukou policy relaxation favors later cohorts over earlier cohorts; and (4) among demographically comparable people, having experienced spatial mobility is correlated with having career advancement experience.

Two Aspects of the Rural-Urban Divide and Educational Stratification in China: A Trajectory Analysis.

Contextualized in China's social change of the past half-century, this paper develops the notion of dichotomous inequality to conceptualize the two aspects of China's rural-urban divide in educational inequality-the household registration system () assigns people to a top-bottom hierarchy, and the rural-urban schooling system institutionalizes unequal resource distribution and diverse school mission. Based on this conceptualization, we formulate a Chinese version of the maximally maintained inequality (MMI) hypothesis. We capitalize on individual educational history data from the China General Social Survey (CGSS) 2008 and conduct a trajectory analysis using the generalized mixture modeling to estimate the differential effects of the two aspects of rural-urban divide on educational inequality in China.

Parental Spending on School-Age Children: Structural Stratification and Parental Expectation.

As consumption expenditures are increasingly recognized as direct measures of children's material well-being, they provide new insights into the process of intergenerational transfers from parents to children. Little is known, however, about how parents allocate financial resources to individual children. To fill this gap, we develop a conceptual framework based on stratification theory, human capital theory, and the child-development perspective; exploit unique child-level expenditure data from Child Supplements of the PSID; and employ quantile regression to model the distribution of parental spending on children.

Rural Panel Surveys in Developing Countries: A Selective Review.

Rural panel surveys are the most appropriate means to provide data for studying the unprecedented rapid migration and urbanization currently taking place in China and other developing countries. To maximize heterogeneity in urbanization and development over the last three decades, we selected rural panel surveys from five Asian countries, including India, Indonesia, Nepal, Thailand, and China. This paper provides a selective review, focusing on their panel survey methodology, which is organized based on our proposed four basics of panel surveys - representativeness, retrospect-prospect, multilevel tracking, and temporality.

Admission-Group Salary Differentials in the United States: The Significance of Labor Market Institutional Selection of High-Skilled Workers.

In 1990 a temporary-to-permanent pathway was established for highly skilled workers admitted to the United States under nonimmigrant programs. The paper argues that this policy shift has allowed employers to play a crucial role in the immigration of highly skilled workers, thereby creating labor-market institutional selection that gives a salary advantage to highly skilled temporary-admitted workers retained in the United States. Through analyses of the salary differentials among admission-category groups, the paper finds that the salary advantage is based on recruitment from Western countries, adjustment from temporary to permanent status after a second employer screening, working in the information technology sector and the private sector, holding a supervisory position, or having a skill-matched job, all of which are consequences of institutional selection rather than individual self-selection.

Distinct trajectories in the transition to adulthood: are children of immigrants advantaged?

Studies on children of immigrants have generally ignored distinct developmental trajectories during adolescence and their role in the transition to adulthood. This study identifies distinct trajectories in cognitive, sociobehavioral, and psychological domains and estimates their consequences for young adults. Drawing data from a nationally representative sample of 10,795 adolescents aged 13-17 who were followed up to ages 25-32, the study uses growth mixture modeling to test advantages for children of immigrants.

Cumulative Causation of Rural Migration and Initial Peri-Urbanization in China.

This paper posits that rural migration feeds the high demand for cheap labor in peri-urbanization, which is driven by globalization, flows of foreign capital, and entrepreneurial local governments. While the gravity model and push/pull perspective ignore the dynamics of migratory course, we use the cumulative causation of migration theory to conceptualize social expectations for outmigration and social resources from migrant networks in destinations. Four major findings are drawn from this demographic analysis based on micro data from China's 2000 Census.

Linking Dichotomous Segregation with Multi-group Segregation: Weighted Segregation Ratios in Selected U. S. Metropolitan Areas.

The U. S. residential landscape is increasingly multi-racial and multi-ethnic, giving rise to the question of how to compare dichotomous segregation among multiple groups living in the same area.

Immigration and The American Obesity Epidemic.

Immigration is an important population dynamic at work in the U.S. but we know little about its impact on American obesity.

The Role of School in the Upward Mobility of Disadvantaged Immigrants' Children.

How can we explain exceptional advancement by disadvantaged immigrants' children? Extending segmented assimilation theory, this article traces the structural and relational attributes of high schools attended by young adults who reached their late twenties in 2000. Hypotheses are derived from theories in sociology of education and tested with four waves of data from the National Educational Longitudinal Study (NELS). The authors offer three major findings.

Games Parents and Adolescents Play: Risky Behaviors, Parental Reputation, and Strategic Transfers.

This paper examines parental reputation formation in intra-familial interactions. In a repeated two-stage game, children decide whether to drop out of high school or daughters decide whether to have births as teens and parents then decide whether to provide support to their children beyond age 18. Drawing on Milgrom and Roberts (1982) and Kreps and Wilson (1982), we show that, under certain conditions, parents have the incentive to penalize older children for their adolescent risk-taking behaviours in order to dissuade their younger children from such behaviours when reaching adolescence.

HIV status and union dissolution in sub-Saharan Africa: the case of Rakai, Uganda.

Little is known about the impact of HIV infection on the disruption of families through separation, divorce, and widowhood. Using life tables and multinomial logistic regression, this research examined the influence of HIV status on the risk of separation or divorce and widowhood among women in Rakai, Uganda. The multivariate results revealed that dissolution is more common among HIV-infected women and that infected women in HIV-discordant couples are especially likely to face separation or divorce than women in other HIV-status couples.

The schooling of children of immigrants: contextual effects on the educational attainment of the second generation.

We supplement earlier published findings on the academic achievement of the immigrant second generation with an analysis of school contextual effects based on the same large data set used by the best-known prior analyses, the Children of Immigrants Longitudinal Study. A hierarchical model of contextual and individual-level effects on academic achievement and school attrition reveals patterns that reproduce those found in national student surveys but also others that are unique to the second generation. Among the latter are the resilient negative effect of length of U.