Family Complexity and Children's Behavior Problems over Two U.S. Cohorts.

OBJECTIVE: We consider the prevalence of family complexity and its association with children's externalizing behavior problems over children's life course and over historical time. BACKGROUND: A growing literature has demonstrated the prevalence and multidimensional nature of family complexity and its association with child behavior. The nature/strength of this association may have changed in recent cohorts as family complexity has become more common. METHOD: Data are from the 1997 and 2014 cohorts of the Panel Study of Income Dynamics Child Development Supplement. Samples represent U.S. children ages 0-12 years born since 1985 (N=5,030). Ordinary least squares regression estimated change in the association between family complexity and behavior between cohorts. Difference-in-difference models estimated baseline and longitudinal differences in children's behavior as linked to family complexity. RESULTS: The prevalence of family complexity has stabilized over the last two decades, and the antecedents to parental repartnering and complex sibship organization remain similar. The expectation that increasing family complexity contributes to elevated behavior problem scores was not supported. Instead, children who eventually acquired a step- or half-sibling or who experienced parents' union dissolution had elevated behavior problems prior to those changes. CONCLUSION: The prevalence of and precursors to complex family organization were stable across recent child cohorts. The observed association between family complexity and child behavior problems may be attributable to selection mechanisms linked to both parents' family formation trajectories and to children's behavior, rather than to family change itself.

Race/Ethnic Differences in Nonresident Fathers' Involvement after a Nonmarital Birth.

OBJECTIVES: This article examines how the levels of nonresidential father involvement (over child ages 1 to 9) differ by race/ethnicity (comparing White, Black and Hispanic fathers), and then considers how individual and couple characteristics may 'account for' any observed differences. METHOD: Data from the Fragile Families and Child Wellbeing Study (N = 2,447) and random effects models were used to examine how nonresidential father involvement (with respect to time, engagement, shared responsibility, and coparenting with mothers) is differentiated by race and ethnicity. RESULTS: Overall, Black nonresident fathers were significantly more likely to spend time and engage in activities with their children as compared to Hispanic fathers-but not White fathers. Black fathers also shared responsibilities more frequently and displayed more effective coparenting than Hispanic and White fathers. CONCLUSIONS: Fathers' involvement with children is shown to differ across major race/ethnic groups, with implications for children as well as for future research and public policy.

Endotoxin reduction in protein solutions using octyl ß-D-1-thioglucopyranoside wash on chromatography media.

Endotoxins are complex molecules and one of the most challenging impurities requiring separation in biopharmaceutical protein purification processes. Usually these contaminants are cleared during the downstream process, but if endotoxin interacts with the target protein it becomes difficult to remove. In the present study we identified a detergent, octyl-ß-D-1-thioglucopyranoside (OTG), that disrupted endotoxin-protein interactions. The integration of this detergent into washes on several chromatography media was demonstrated to provide a separation tool for decreasing endotoxin from target proteins. This study also examined the mechanism of OTG endotoxin-protein disruption through phase modification incubation and chromatographic studies. The non-ionic OTG wash was shown to break both hydrophobic and electrostatic interactions between the endotoxin and protein. This mechanism contrasts with the breaking of hydrophobic interactions by washing with known endotoxin decreasing Triton X-100 detergent. The difference in mechanisms likely results in the ability of OTG to decrease endotoxin to levels less than those resulting from a detergent wash such as Triton X-100. Finally, we show the impact of the OTG endotoxin removal tool on the biopharmaceutical industry. While maintaining monomer purity and activity levels, endotoxin removal from a fusion protein allowed for decreased background levels in a T cell functional assay. The lowered baseline of T cell responses allowed for more effective detection of molecular interaction with the cells. The detergent wash can be used to both decrease the overall level of endotoxin in a purified protein solution and to enable more effective screening of lead candidate molecules.

Trajectories of relationship supportiveness after childbirth: Does marriage matter?

Relationship quality for married couples typically declines after the birth of a (first) child, as parenthood brings new identities, stresses, and responsibilities for mothers and fathers. Yet, it is less clear whether nonmarital relationship quality follows a similar trajectory, particularly given the greater selectivity of nonmarital relationships that persist over time. This paper uses data from the Fragile Families and Child Wellbeing Study (N = 3,459) with latent growth curve models to examine relationship quality (measured by mothers' perceived supportiveness about fathers) for married and unmarried couples over nine years after a child's birth. Findings suggest that marriage at birth is protective for relationship supportiveness over time, net of various individual characteristics associated with marriage, compared to all unmarried couples at birth; however, marriage does not differentiate supportiveness compared to the subset of unmarried couples who remain stably together. Also, unmarried couples who get married after the birth have more supportive relationships compared to all unmarried couples who do not marry-though less so when compared to couples who remain stably together.

Fathers' Investments of Money and Time Across Residential Contexts.

Fathers' roles in family life have changed dramatically over the past 50 years. In addition to ongoing breadwinning responsibilities, many fathers are now involved in direct caregiving and engagement with children. Yet there is considerable variation in what fathers do, especially depending on whether they live with or away from their child. In this article, the authors use data from the Fragile Families and Child Wellbeing Study (N = 3,869) to describe how fathers' economic capacities (money) and direct involvement with children (time) are associated over child ages 1 to 9 for resident versus nonresident fathers, net of confounding factors. They found suggestive evidence that money and time investments operate differently across residential contexts: Resident fathers experience a trade-off between market work and time involved with children. In contrast, nonresident fathers' higher economic capacities are associated with more time involvement, underscoring the greater challenge for such fathers to remain actively involved.

Development of Electrochemiluminescent Serology Assays to Measure the Humoral Response to Antigens of Respiratory Syncytial Virus.

Sensitive and precise serology assays are needed to measure the humoral response to antigens of respiratory syncytial virus (RSV) following natural infection or vaccination. We developed and evaluated a collection of electrochemiluminescent (ECL) serology assays using four RSV antigens (F, N, Ga and Gb). To assess the merits of ECL technology, the four ECL serology assays were evaluated using a well-characterized "gold standard" panel of acute and convalescent serum samples from fifty-nine RSV-positive and thirty RSV-negative elderly subjects (≥65 years old). The combined results from the four ECL assays demonstrated good concordance to the "gold standard" diagnosis, reaching 95% diagnostic sensitivity and 100% diagnostic specificity. Additionally, a combination of ECL assays provided higher diagnostic sensitivity than a commercially available diagnostic ELISA or cell-based microneutralization assay. In summary, these data demonstrate the advantages of using ECL-based serology assays and highlight their use as a sensitive diagnostic approach to detect recent RSV infection in an elderly population.

Interfacial dilatational deformation accelerates particle formation in monoclonal antibody solutions.

Protein molecules are amphiphilic moieties that spontaneously adsorb at the air/solution (A/S) interface to lower the surface energy. Previous studies have shown that hydrodynamic disruptions to these A/S interfaces can result in the formation of protein aggregates that are of concern to the pharmaceutical industry. Interfacial hydrodynamic stresses encountered by protein therapeutic solutions under typical manufacturing, filling, and shipping conditions will impact protein stability, prompting a need to characterize the contribution of basic fluid kinematics to monoclonal antibody (mAb) destabilization. We demonstrate that dilatational surface deformations are more important to antibody stability when compared to constant-area shear of the A/S interface. We have constructed a dilatational interfacial rheometer that utilizes simultaneous pressure and bubble shape measurements to study the mechanical stability of mAbs under interfacial aging. It has a distinct advantage over methods utilizing the Young-Laplace equation, which incorrectly describes viscoelastic interfaces. We provide visual evidence of particle ejection from dilatated A/S interfaces and spectroscopic data of ejected mAb particles. These rheological studies frame a molecular understanding of the protein-protein interactions at the complex-fluid interface.

Patterns and predictors of coparenting after unmarried parents part.

Nonmarital childbearing has increased dramatically during the past several decades, and the majority of unmarried couples will break up while their child is still young. As a result, many children will be raised by their biological parents living apart, ideally working together as effective coparents. In this article, we use data from the Fragile Families and Child Wellbeing Study (N = 1,193) to describe the trajectories of coparenting over 6 years following the end of a nonmarital relationship and to identify individual and interpersonal characteristics associated with better coparenting over time. Results from growth mixture models (GMMs) suggest that there are 4 primary trajectories of coparenting over time, and results from multinomial logit models show that couples' race/ethnicity, maternal health, and parents' relationship and fertility characteristics are the most salient predictors of coparenting trajectories. These results highlight the heterogeneity of parents' interaction vis-à-vis their common child after a nonmarital union dissolves and point to the challenges of supporting families and children amid high instability.

Improving target cell specificity using a novel monovalent bispecific IgG design.

Monovalent bispecific IgGs cater to a distinct set of mechanisms of action but are difficult to engineer and manufacture because of complexities associated with correct heavy and light chain pairing. We have created a novel design, "DuetMab," for efficient production of these molecules. The platform uses knobs-into-holes (KIH) technology for heterodimerization of 2 distinct heavy chains and increases the efficiency of cognate heavy and light chain pairing by replacing the native disulfide bond in one of the CH1-CL interfaces with an engineered disulfide bond. Using two pairs of antibodies, cetuximab (anti-EGFR) and trastuzumab (anti-HER2), and anti-CD40 and anti-CD70 antibodies, we demonstrate that DuetMab antibodies can be produced in a highly purified and active form, and show for the first time that monovalent bispecific IgGs can concurrently bind both antigens on the same cell. This last property compensates for the loss of avidity brought about by monovalency and improves selectivity toward the target cell.

Educational differences in early childbearing: A cross-national comparative study.

BACKGROUND: Recent research on fertility in industrialized countries focuses primarily on delayed childbearing, despite the facts that large numbers of women continue to enter parenthood at relatively young ages and that early childbearing has been linked to economic disadvantage. OBJECTIVE: This cross-national comparative study describes relationships between women's educational attainment and young age at first birth and evaluates the extent to which these differences have changed over time for women born 1955-1981. METHODS: Defining 'early' childbearing as the age by which 20% of first births have occurred to women in a given birth cohort and country, we describe differences in early childbearing by educational attainment across three cohorts of women in 20 countries. RESULTS: We find a strong negative educational gradient in early childbearing across all 20 countries and some evidence of an increase in the relative prevalence of early childbearing among the least-educated women. In 10 countries, the relative prevalence of early childbearing among women with low education is significantly higher for one or both of the more recent birth cohorts compared to the earliest cohort. However, many countries show no significant change, and in one country (Poland) there is modest evidence of a decreasing educational gap. CONCLUSIONS: Evidence that educational differences in early childbearing have grown in some countries is generally consistent with the notion of family bifurcation and 'diverging destinies' by socioeconomic status. However, the pattern is not universal and future work should examine the various factors that shape these patterns, including the role of public policies.

Parents' Relationship Quality and Children's Behavior in Stable Married and Cohabiting Families.

Although an extensive literature has shown that family structure is linked with child well-being, less well understood is how the dynamics within families affect children, in particular the extent to which positive mother-father relationship quality is linked with children's outcomes. In this study the authors used data from the Fragile Families and Child Wellbeing Study (N = 773) to examine how couple supportiveness in stable coresident families is related to children's externalizing and internalizing behavioral problems over ages 3 through 9. Using latent growth curve and fixed effects models, they found that parents' greater supportiveness has a slight association with lower levels of children's behavioral problems. Using cross-lagged structural equation models to examine the direction of the association, they also found some evidence that parents' relationship quality and children's behavioral problems are reciprocally related. Overall, this study suggests that more positive couple interactions are beneficial for children residing with both of their biological parents.

Childbearing across partnerships in Australia, the United States, Norway, and Sweden.

This article compares mothers' experience of having children with more than one partner in two liberal welfare regimes (the United States and Australia) and two social democratic regimes (Sweden and Norway). We use survey-based union and birth histories in Australia and the United States and data from national population registers in Norway and Sweden to estimate the likelihood of experiencing childbearing across partnerships at any point in the childbearing career. We find that births with new partners constitute a substantial proportion of all births in each country we study. Despite quite different arrangements for social welfare, the determinants of childbearing across partnerships are very similar. Women who had their first birth at a very young age or who are less well-educated are most likely to have children with different partners. The educational gradient in childbearing across partnerships is also consistently negative across countries, particularly in contrast to educational gradients in childbearing with the same partner. The risk of childbearing across partnerships increased dramatically in all countries from the 1980s to the 2000s, and educational differences also increased, again, in both liberal and social democratic welfare regimes.

Examining the antecedents of U.S. nonmarital fatherhood.

Despite the dramatic rise in U.S. nonmarital childbearing in recent decades, limited attention has been paid to factors affecting nonmarital fatherhood (beyond studies of young fathers). In this article, we use data from the 2002 National Survey of Family Growth and the National Longitudinal Survey of Youth 1979 cohort to examine the antecedents of nonmarital fatherhood, as compared to marital fatherhood. Overall, we find the strongest support across both data sets for education and race/ethnicity as key predictors of having a nonmarital first birth, consistent with prior literature about women's nonmarital childbearing and about men's early/teenage fatherhood. Education is inversely related to the risk of nonmarital fatherhood, and minority (especially black) men are much more likely to have a child outside of marriage than white men. We find little evidence that employment predicts nonmarital fertility, although it does strongly (and positively) predict marital fertility. High predicted earnings are also associated with a greater likelihood of marital childbearing but with a lower likelihood of nonmarital childbearing. Given the socioeconomic disadvantage associated with nonmarital fatherhood, this research suggests that nonmarital fatherhood may be an important aspect of growing U.S. inequality and stratification both within and across generations.

What Kids Get from Parents: Packages of Parental Involvement across Complex Family Forms.

While demographers have continued to document the notable family changes that have occurred in recent decades, the nature of family functioning across diverse family forms is less well understood. In particular, we know little about the level and quality of parental investment that children receive across a range of contemporary family types. In this paper, we use data from a recent U.S. urban birth cohort to examine the 'package' of parental involvement that young children receive in two key domains across family types. We aggregate parent-child engagement across three potential parent(-figures)-biological mothers, biological fathers (resident or non-resident), and resident social fathers-and also assess the child's household income. We examine parental investments at child age 5 and changes in investments between child ages 1 and 5 by family structure categories. Overall, we find that children living with both of their married biological parents are advantaged with respect to both economic resources and parental engagement, while children living with single mothers-or their mother and a cohabiting social father-fare especially poorly in both domains; children in married social-father families receive higher overall levels of parental engagement than those in biological-father families but are much less economically advantaged. Our research sheds light on how changing family demography is related to parental investments in children, which may have implications for public policies designed to support disadvantaged families.

Mothers' Repartnering after a Nonmarital Birth.

This paper examines the prevalence, predictors and outcomes of unmarried mothers' repartnering patterns following a nonmarital birth. Results indicate that, within five years after a birth, approximately two-thirds of unmarried mothers ended their relationship with the focal child's biological father, and over half of these mothers entered new partnerships. Among those who repartnered, 60 percent of mothers formed unions with men with higher economic capabilities than their former partners, 20 percent formed unions with men with similar capabilities, and 20 percent formed unions with men with lower capabilities. This pattern holds for both nonresidential and coresidential unions. Our findings are consistent with marriage market, learning, and evolutionary biology theories about union formation, and they provide support for qualitative evidence that unmarried mothers have high standards for new partners. While many mothers are able to successfully find new partners with better economic capabilities, many other mothers remain unpartnered, likely due (at least in part) to the limited pool of potential partners with relatively high levels of economic capabilities.

"Like Parent, Like Child?": The intergenerational transmission of nonmarital childbearing.

Data from the 2002 National Survey of Family Growth (N=11,180) are used to examine the intergenerational transmission of nonmarital childbearing for US men and women. Findings suggest that being born to unmarried parents increases the risk of offspring having a nonmarital first birth, net of various confounding characteristics. This intergenerational link appears to particularly operate via parents' breaking up before offspring are age 14 and offspring's young age at first sex. While the link across two generations in nonmarital childbearing is not accounted for by parents' socioeconomic status (measured as fathers' education), several mediating factors vary by socioeconomic background. Gender and race/ethnicity also moderate the intergenerational transmission of nonmarital childbearing. This research sheds light on the prevalence of, and process by which, nonmarital childbearing is repeated across generations, which has important implications for long-term social stratification and inequality.

Multipartnered Fertility and Depression among Fragile Families.

We used data from the Fragile Families and Child Wellbeing Study to examine the association between multipartnered fertility (MPF)-when parents have children with more than one partner-and depression. Random effects models suggested that MPF is associated with a greater likelihood of depression, net of family structure and other covariates. However, these associations disappeared in more conservative fixed effects models that estimated changes in MPF as a function of changes in depression. Results also suggested that social selection may account for the link between MPF and depression for fathers (but not mothers), as depressed fathers with no MPF were more likely to have a child by a new partner four years later. Ultimately, MPF and depression may be reciprocally related and part of broader processes of social disadvantage.

"Couples as Partners and Parents over Children's Early Years"

We used data from the Fragile Families and Child Wellbeing Study to examine how couple relationship quality and parental engagement are linked over children's early years-when they are infants, toddlers, and preschoolers. Our sample included 1,630 couples that were coresident over years 1 to 3 and 1,376 couples that were coresident over years 3 to 5 (1,196 over both periods). Overall, we found that better relationship quality predicted greater parental engagement for both mothers and fathers-especially in the infant to toddler years; in contrast, we found little evidence that parental engagement predicted future relationship quality. Married and cohabiting couples were generally similar in how relationship quality and parenting were linked.