104 research outputs found

    The early socioeconomic effects of teenage childbearing

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    A large body of literature has documented a negative correlation between teenage childbearing and teen mothersā€™ socioeconomic outcomes, yet researchers continue to disagree as to whether the association represents a true causal effect. This article extends the extant literature by employing propensity score matching with a sensitivity analysis using Rosenbaum bounds. The analysis of recent cohort data from the National Longitudinal Study of Adolescent Health shows that (1) teenage childbearing has modest but significant negative effects on early socioeconomic outcomes and (2) unobserved covariates would have to be more powerful than known covariates to nullify the propensity score matching estimates. The author concludes by suggesting that more research should be done to address unobserved heterogeneity and the long-term effects of teenage childbearing for this young cohort.propensity score matching, Rosenbaum Bounds, selection bias, teen childbearing

    Three essays on the micro basis of socioeconomic inequality: the role of cognitive and noncognitive skills

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    This dissertation explores the effect of cognitive and noncognitive skills on three socioeconomic outcomes: wage differentials, individual patterns of educational assortative mating, and the socioeconomic consequences of teen motherhood. Although research has been keen on identifying early predictors of socioeconomic attainment, a systematic view of the linkages between individualsā€™ own attributes formed in childhood and adolescence and subsequent outcomes has yet to come. In this project, I seek to fill this gap by identifying cognitive and noncognitive skills as a micro basis of socioeconomic inequality. Correlated but distinct from cognitive skills, noncognitive skills are conceptualized as enduring dispositions that represent a form of cultural capital. Because both types of skills are highly dependent on socioeconomic background, I hypothesized that individual-level skill differences function as a key channel through which intergenerational mobility is associated with various forms of socioeconomic inequality. This study begins by examining the impact of both cognitive and noncognitive skills on between- and within-education group wage inequality, using data from the National Longitudinal Survey of Youth 1979 (NLSY79) and quantile regressions. While the economic return to education has been proposed as a parsimonious explanation for rising wage inequality and its currently high level, this account focuses mainly on between-education group wage inequality and the demand for cognitive skills. Results from my analysis shows that 1) while the economic return to education is the robust explanation for wage inequality, both cognitive and noncognitive skills contribute significantly to reducing the college wage premium and wage dispersions within college graduates; 2) noncogntive skills play a more pronounced role in wage inequality among college graduates; and 3) the wage effect of both skills as an early predictor of earnings strengthens as workers reach their prime ages in the labor market. These findings suggest that the family may be an important institutional actor responsible for wage inequality. In the subsequent chapter, I use data from the National Longitudinal Study of Adolescent Health (Add Health) and the NLSY79 to investigate the role of cognitive and noncognitive skills in individual patterns of educational assortative mating in adolescence and adulthood. This paper argues that to the extent that skill differences are associated with education-based mate selection, intergenerational mobility operates at an intimate level of the mate selection process. Multinomial logistic regression results show that cognitive and noncognitive skills are positively associated with the probability of transitioning into marrying college graduates and, to a lesser degree, with that of dating college-bound partners. I also find a gender difference in the role of skill differences: noncognitive skills play a more salient role in education-based mate sorting for women, whereas it is cognitive skills that primarily do so for men, indicating a normative attitude toward mate selection that regards "smartness" as more attractive to women than to men. These findings imply that the intergenerational transmission of familial resources affects childrenā€™s mate selection by not simply investing in their educational attainment but also strengthening their cognitive and noncognitive skills. Finally, I reevaluate the socioeconomic effect of teenage childbearing. Despite a 30-year debate about the consequences of adolescent fertility, finding its "true" effect still has been elusive. This concern stems from 1) theoretical considerations of early motherhood as a harmful event and/or its higher likelihood among disadvantaged young women and 2) methodological challenges against selection bias. Alternative models have been developed, but tend to rely on strong assumptions and unrepresentative samples. This paper extends the extant literature by taking a counterfactual approach using propensity score matching, conducting a sensitivity analysis employing the Rosenbaum bounds to address selection bias on unobserved covariates, and using data from Add Health. Results show that while teen mothersā€™ preexisting socioeconomic disadvantages and their lower level of cognitive and noncognitive skills play a nontrivial role, teen motherhood has significantly negative effects on early socioeconomic outcomes with the exception of public assistance receipt. The sensitivity analysis suggests that selection bias due to unobserved covariates would have to be very powerful to nullify these findings

    SPGP: Structure Prototype Guided Graph Pooling

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    While graph neural networks (GNNs) have been successful for node classification tasks and link prediction tasks in graph, learning graph-level representations still remains a challenge. For the graph-level representation, it is important to learn both representation of neighboring nodes, i.e., aggregation, and graph structural information. A number of graph pooling methods have been developed for this goal. However, most of the existing pooling methods utilize k-hop neighborhood without considering explicit structural information in a graph. In this paper, we propose Structure Prototype Guided Pooling (SPGP) that utilizes prior graph structures to overcome the limitation. SPGP formulates graph structures as learnable prototype vectors and computes the affinity between nodes and prototype vectors. This leads to a novel node scoring scheme that prioritizes informative nodes while encapsulating the useful structures of the graph. Our experimental results show that SPGP outperforms state-of-the-art graph pooling methods on graph classification benchmark datasets in both accuracy and scalability.Comment: 18 pages, 6 figure

    Trends in Body Mass Index in Adolescence and Young Adulthood in the United States: 1959ā€“2002

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    AbstractPurposeThis study examined trends in body mass index (BMI) during the transition from adolescence to young adulthood by gender and race, using national data from the United States spanning for >40 years from 1959 and 2002. Although past research has investigated BMI trends separately in childhood/adolescence and adulthood, this study uniquely focused on the transition to adulthood (12ā€“26 years) to identify the emergence of the obesity epidemic during this critical life-stage.MethodsLongitudinal and cross-sectional data were obtained from four nationally representative surveys: National Health and Nutrition Examination Survey, National Longitudinal Study of Adolescent Health, National Health Interview Survey, and National Longitudinal Surveys of Youth (NLSY79 and NLSY97). The analysis tracked age trends in BMI by time, which allowed for the examination of how BMI changed during the transition to adulthood and whether the patterns of change varied by period. Data best suited for trend analysis were identified. Age trends in BMI by gender and race were graphed and regression analysis was used to test for significant differences in the trends using the National Health and Nutrition Examination Survey and National Longitudinal Study of Adolescent Health.ResultsBMI increased sharply in the adolescent ages, beginning in the 1990s and among young adults around 2000. This age pattern of BMI increase was more dramatic among females and blacks, particularly black females.ConclusionsBMI increased during the transition to adulthood and these increases have grown larger over time. Obesity prevention efforts should focus on this high-risk transition period, particularly among minority populations

    Obesity in the Transition to Adulthood: Predictions Across Race/Ethnicity, Immigrant Generation, and Sex

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    With longitudinal data we traced how race, ethnic, and immigrant disparities in body mass index (BMI) change over time as adolescents (ages 11ā€“19) transition to young adulthood (ages 20ā€“28)

    xCT-Driven Expression of GPX4 Determines Sensitivity of Breast Cancer Cells to Ferroptosis Inducers

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    Inducers of ferroptosis such as the glutathione depleting agent Erastin and the GPX4 inhibitor Rsl-3 are being actively explored as potential therapeutics in various cancers, but the factors that determine their sensitivity are poorly understood. Here, we show that expression levels of both subunits of the cystine/glutamate antiporter xCT determine the expression of GPX4 in breast cancer, and that upregulation of the xCT/selenocysteine biosynthesis/GPX4 production axis paradoxically renders the cancer cells more sensitive to certain types of ferroptotic stimuli. We find that GPX4 is strongly upregulated in a subset of breast cancer tissues compared to matched normal samples, and that this is tightly correlated with the increased expression of the xCT subunits SLC7A11 and SLC3A2. Erastin depletes levels of the antioxidant selenoproteins GPX4 and GPX1 in breast cancer cells by inhibiting xCT-dependent extracellular reduction which is required for selenium uptake and selenocysteine biosynthesis. Unexpectedly, while breast cancer cells are resistant compared to nontransformed cells against oxidative stress inducing drugs, at the same time they are hypersensitive to lipid peroxidation and ferroptosis induced by Erastin or Rsl-3, indicating that they are \u27addicted\u27 to the xCT/GPX4 axis. Our findings provide a strategic basis for targeting the anti-ferroptotic machinery of breast cancer cells depending on their xCT status, which can be further explored

    Gypsum-Dependent Effect of NaCl on Strength Enhancement of CaO-Activated Slag Binders

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    This study explores the combined effect of NaCl and gypsum on the strength of the CaO-activated ground-granulated blast furnace slag (GGBFS) binder system. In the CaO-activated GGBFS system, the incorporation of NaCl without gypsum did not improve the strength of the system. However, with the presence of gypsum, the use of NaCl yielded significantly greater strength than the use of either gypsum or NaCl alone. The presence of NaCl largely increases the solubility of gypsum in a solution, leading to a higher concentration of sulfate ions, which is essential for generating more and faster formations of ettringite in a fresh mixture of paste. The significant strength enhancement of gypsum was likely due to the accelerated and increased formation of ettringite, accompanied by more efficient filling of pores in the system

    Recognition of Transmembrane Protein 39A as a Tumor-Specific Marker in Brain Tumor

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    Transmembrane protein 39A (TMEM39A) belongs to the TMEM39 family. TMEM39A gene is a susceptibility locus for multiple sclerosis. In addition, TMEM39A seems to be implicated in systemic lupus erythematosus. However, any possible involvement of TMEM39A in cancer remains largely unknown. In the present report, we provide evidence that TMEM39A may play a role in brain tumors. Western blotting using an anti-TMEM39A antibody indicated that TMEM39A was overexpressed in glioblastoma cell lines, including U87-MG and U251-MG. Deep-sequencing transcriptomic profiling of U87-MG and U251-MG cells revealed that TMEM39A transcripts were upregulated in such cells compared with those of the cerebral cortex. Confocal microscopic analysis of U251-MG cells stained with anti-TMEM39A antibody showed that TMEM39A was located in dot-like structures lying close to the nucleus. TMEM39A probably located to mitochondria or to endosomes. Immunohistochemical analysis of glioma tissue specimens indicated that TMEM39A was markedly upregulated in such samples. Bioinformatic analysis of the Rembrandt knowledge base also supported upregulation of TMEM39A mRNA levels in glioma patients. Together, the results afford strong evidence that TMEM39A is upregulated in glioma cell lines and glioma tissue specimens. Therefore, TMEM39A may serve as a novel diagnostic marker of, and a therapeutic target for, gliomas and other cancers

    Values of harmonic weak Maass forms on Hecke orbits

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    Let q:=e2Ļ€izq:=e^{2 \pi iz}, where zāˆˆHz \in \mathbb{H}. For an even integer kk, let f(z):=qhāˆm=1āˆž(1āˆ’qm)c(m)f(z):=q^h\prod_{m=1}^{\infty}(1-q^m)^{c(m)} be a meromorphic modular form of weight kk on Ī“0(N)\Gamma_0(N). For a positive integer mm, let TmT_m be the mmth Hecke operator and DD be a divisor of a modular curve with level NN. Both subjects, the exponents c(m)c(m) of a modular form and the distribution of the points in the support of Tm.DT_m. D, have been widely investigated. When the level NN is one, Bruinier, Kohnen, and Ono obtained, in terms of the values of jj-invariant function, identities between the exponents c(m)c(m) of a modular form and the points in the support of Tm.DT_m.D. In this paper, we extend this result to general Ī“0(N)\Gamma_0(N) in terms of values of harmonic weak Maass forms of weight 00. By the distribution of Hecke points, this applies to obtain an asymptotic behaviour of convolutions of sums of divisors of an integer and sums of exponents of a modular form

    Anti-Biofouling Features of Eco-Friendly Oleamide-PDMS Copolymers

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    The biofouling of marine organisms on a surface induces serious economic damage. One of the conventional anti-biofouling strategies is the use of toxic chemicals. In this study, a new eco-friendly oleamide-PDMS copolymer (OPC) is proposed for sustainable anti-biofouling and effective drag reduction. The anti-biofouling characteristics of the OPC are investigated using algal spores and mussels. The proposed OPC is found to inhibit the adhesion of algal spores and mussels. The slippery features of the fabricated OPC surfaces are examined by direct measurement of pressure drops in channel flows. The proposed OPC surface would be utilized in various industrial applications including marine vehicles and biomedical devices. Ā© Copyright Ā© 2020 American Chemical Society.1
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