Neural mechanisms of language development in infancy

Understanding the neural processes underpinning individual differences in early language development is of increasing interest, as it is known to vary in typical development and to be quite heterogeneous in neurodevelopmental conditions. However, few studies to date have tested whether early brain measures are indicative of the developmental trajectory of language, as opposed to language outcomes at specific ages. We combined recordings from two longitudinal studies, including typically developing infants without a family history of autism, and infants with increased likelihood of developing autism (infant-siblings) (N = 191). Electroencephalograms (EEG) were recorded at 6 months, and behavioral assessments at 6, 12, 18, 24 and 36 months of age. Using a growth curve model, we tested whether absolute EEG spectral power at 6 months was associated with concurrent language abilities, and developmental change in language between 6 and 36 months. We found evidence of an association between 6-month alpha-band power and concurrent, but not developmental change in, expressive language ability in both infant-siblings and control infants. The observed association between 6-month alpha-band power and 6-month expressive language was not moderated by group status, suggesting some continuity in neural mechanisms.     

The status and factions theory of influence

We review a relatively new theoretical research program on the joint effects of status and the distribution of opinions on social influence. The status and factions theory of influence combines sociological insights about status generalization with psychological research on how the distribution of opinions promotes social influence. To date, several published studies support the logic of the theory, including how the effect of status varies with the distribution of opinions and the intervening theoretical mechanism. The former has been replicated a number of times, but only one study to date has truly tested the mechanism. Uncertainty reduction has been found to explain some of the joint effects of status and the distribution of opinions on social influence, but there is room for improvement. Consequently, after we discuss the existing literature, we identify additional mechanisms that may be worth pursuing in the future and also some applications of the theory's utility.     

Crossing over to cross-over trials

If you have never designed a cross-over trial before then Byron Jones and Scott Haughie give some helpful tips on how to do it.     

GRAPHICAL SENSITIVITY ANALYSIS WITH DIFFERENT METHODS OF IMPUTATION FOR A TRIAL WITH PROBABLE NON‐IGNORABLE MISSING DATA

Graphical sensitivity analyses have recently been recommended for clinical trials with non‐ignorable missing outcome. We demonstrate an adaptation of this methodology for a continuous outcome of a trial of three cognitive‐behavioural therapies for mild depression in primary care, in which one arm had unexpectedly high levels of missing data. Fixed‐value and multiple imputations from a normal distribution (assuming either varying mean and fixed standard deviation, or fixed mean and varying standard deviation) were used to obtain contour plots of the contrast estimates with their P‐values superimposed, their confidence intervals, and the root mean square errors. Imputation was based either on the outcome value alone, or on change from baseline. The plots showed fixed‐value imputation to be more sensitive than imputing from a normal distribution, but the normally distributed imputations were subject to sampling noise. The contours of the sensitivity plots were close to linear in appearance, with the slope approximately equal to the ratio of the proportions of subjects with missing data in each trial arm.     

Attitudes and beliefs about hepatitis B vaccination among gay men: the Birmingham Measurement Study

This study was designed to develop reliable and valid quantitative measures of the beliefs and attitudes toward hepatitis B virus (HBV) vaccination among gay men, using a community-based participatory research approach. A convenience sample of 358 gay men was recruited in two gay bars. Exploratory factor analysis performed on the first split-half sample was used to assess the factor structure from five scales measuring beliefs about HBV vaccination. The scales were based on constructs from the health belief model and the social cognitive theory. Confirmatory factor analysis was performed on the remaining half-sample using structural equation modeling. Multivariable analysis further validated the scales. These findings propose standardized measures that may be useful in assessing the beliefs and attitudes of gay men toward HBV vaccination to guide intervention design and evaluation.     

Housing Discrimination and Residential Mobility: Impacts for Blacks and Whites

We merge metropolitan-level measures of racial discrimination in housing markets derived from two national housing audit studies, along with tract-level 1980 census data, with the 1979-1985 waves of the Panel Study of Income Dynamics to examine the impact of housing discrimination on patterns of residential mobility between neighborhoods of varying racial composition. We find no evidence that housing discrimination in the metropolitan area impedes African Americans' mobility into whiter neighborhoods. Contrary to expectations, in multivariate analyses based on black movers, the level of housing discrimination is positively associated with the percentage of the population that is white in the tract of destination. Housing discrimination against African Americans is positively associated with the rate at which mobile white households move into whiter census tracts. These findings imply that eliminating racial discrimination by real estate and rental agents will fail to increase black residential mobility into racially-mixed and predominantly white neighborhoods. For both black and white households, life-cycle factors, such as age, children, and home ownership, impede mobility out of the current neighborhood. Conditional upon moving, socioeconomic resources, such as education and income, facilitate mobility into whiter neighborhoods.     

Immigration restrictions and the American worker: An examination of competing interpretations

This paper examines three competing interpretations of support for tougher immigration restrictions. One interpretation posits that tighter restrictions are favored by those in direct competition with immigrants for jobs, namely low or unskilled workers who toil in labor markets that are low-paying and often unstable. A second line of thought is that greater restrictions are favored by workers who perceive immigrants as potential competitors in labor markets, even though there may be no real basis for such perceptions. The third interpretation explaining support for tougher restrictions is rooted in a broad based cultural nativism or nationalism, and relies heavily on traditional theories of prejudice and discrimination. Data for the study are derived from the 1992 National Election Survey, Inter-University Consortium for Political and Social Research. Contrary to theoretical expectations, neither actual nor perceived economic insecurity explain variations in current levels of support for tougher immigration restrictions among American workers. The theoretical significance of the findings are discussed and elaborated. Suggestions are made for future research in this important area of inquiry.     

The obesity pay gap: gender,body size,and wage inequalities—a longitudinal study of Chinese adults, 1991–2011

Sociocultural values promoting Western body-type ideals have proliferated over the past 20 years. An important question is whether the same obesity wage penalties seen in the United States, such as wage reductions for obese individuals, are emerging in China as ideals of beauty change to reflect Western ones. We hypothesize that Westernisation will exacerbate the impact of body size on wages for years to come, particularly for urban non-manual workers whose workplaces call for extensive interpersonal relations with employers, colleagues, and customers. This study examines the economic outcomes for individuals aged 18–55, focusing on 6600 female and 8488 male participants in the longitudinal 1991–2011 China Health and Nutrition Survey. Linear fixed-effects regression models estimate the net effect of body mass index (BMI) on wages, as well as the marginal effect of BMI on wages, by survey year. All analyses control for demographic backgrounds and household fixed effects, and are stratified by gender. The results show that normal-weight women with non-manual jobs in 2011 made 2.79–2.95 times more than they had in 1991, while overweight women made 2.66–2.76 times more, and obese women made only 2.57–2.63 times more. The results also indicate that women with non-manual jobs have been subject to wage disparities since 2000. Specifically, the wage disparity for heavier women living in urban areas with non-manual jobs increased significantly after 2000, while current male obesity rates may have been propelled by social acceptance of larger body sizes among men, particularly for manual workers living in rural areas.