Estimation of Benchmark Dose of Lifetime Cadmium Intake for Adverse Renal Effects Using Hybrid Approach in Inhabitants of an Environmentally Exposed River Basin in Japan

The aim of this study is to estimate the reference level of lifetime cadmium intake (LCd) as the benchmark doses (BMDs) and their 95% lower confidence limits (BMDLs) for various renal effects by applying a hybrid approach. The participants comprised 3,013 (1,362 men and 1,651 women) and 278 (129 men and 149 women) inhabitants of the Cd‐polluted and nonpolluted areas, respectively, in the environmentally exposed Kakehashi River basin. Glucose, protein, aminonitrogen, metallothionein, and β₂‐microglobulin in urine were measured as indicators of renal dysfunction. The BMD and BMDL that corresponded to an additional risk of 5% were calculated with background risk at zero exposure set at 5%. The obtained BMDLs of LCd were 3.7 g (glucose), 3.2 g (protein), 3.7 g (aminonitrogen), 1.7 g (metallothionein), and 1.8 g (β₂‐microglobulin) in men and 2.9 g (glucose), 2.5 g (protein), 2.0 g (aminonitrogen), 1.6 g (metallothionein), and 1.3 g (β₂‐microglobulin) in women. The lowest BMDL was 1.7 g (metallothionein) and 1.3 g (β₂‐microglobulin) in men and women, respectively. The lowest BMDL of LCd (1.3 g) was somewhat lower than the representative threshold LCd (2.0 g) calculated in the previous studies. The obtained BMDLs may contribute to further discussion on the health risk assessment of cadmium exposure.     

Spatial pattern changes of grazing cattle population I

Summary A cattle population presents three spatial patterns according to their behaviour. These patterns are as follows: the random spatial pattern which occurs when the cattle move during grazing (feeding), the aggregated spatial pattern which occurs when they rest, and the regular or quasi-regular spatial pattern which occurs when they separate into two or more subgroups. In this study, these three states of behaviour were represented by a mathematical model, and a method to test the pattern statistically was derived.     

Second‐order bias‐corrected AIC in multivariate normal linear models under non‐normality

This paper deals with a bias correction of Akaike's information criterion (AIC) for selecting variables in multivariate normal linear regression models when the true distribution of observation is an unknown non‐normal distribution. It is well known that the bias of AIC is $O(1)$ , and there are a number of the first‐order bias‐corrected AICs which improve the bias to $O(n^{-1})$ , where $n$ is the sample size. A new information criterion is proposed by slightly adjusting the first‐order bias‐corrected AIC. Although the adjustment is achieved by merely using constant coefficients, the bias of the new criterion is reduced to $O(n^{-2})$ . Then, a variance of the new criterion is also improved. Through numerical experiments, we verify that our criterion is superior to others. The Canadian Journal of Statistics 39: 126–146; 2011 © 2011 Statistical Society of Canada     

Unauthorized Status and Youth Development in the United States: Consensus Statement of the Society for Research on Adolescence

In the United States, 5.3 million children and adolescents are growing up either with unauthorized status or with at least one parent who has that status. Until recently, little in the way of research has informed federal, state, and local policy debates related to unauthorized status (e.g., border enforcement, deportation, and a pathway to citizenship) although these issues have important implications for youth development. This statement is a brief summary of the research evidence on multiple domains of development that may be affected by the child or parent's unauthorized status. We also describe the contextual and psychological mechanisms that may link this status to developmental outcomes. We summarize a range of policies and practices that could reduce the developmental harm to children, youth, and their families stemming from this status. Finally, we conclude with recommendations for policy, practice, and research that are based on the evidence reviewed.     

Person‐Environment Fit and Positive Youth Development in the Context of High School Gay–Straight Alliances

Drawing from a person‐environment fit framework, we identified profiles of youth in gay–straight alliances (GSAs) based on the extent to which they received information/resources, socializing/support, and advocacy opportunities in their GSAs and the extent to which this matched what they desired from their GSA along these three functions. Further, we examined profile differences in positive developmental competencies while accounting for community‐contextual factors. In a sample of 290 youth from 42 Massachusetts GSAs, latent profile analyses identified five subgroups. Overall, youth receiving less from their GSAs than they desired, particularly regarding opportunities for advocacy, reported lower levels of self‐reflection, bravery, civic engagement, and agency than youth who received information, socializing/support, and advocacy that matched or exceeded what they desired.     

Parents' Goals for Children: The Dynamic Coexistence of Individualism and Collectivism in Cultures and Individuals

Current scholarship on the cultural value systems of individualism and collectivism, and the associated developmental goals of autonomy and relatedness, has moved beyond grand divide theories to emphasize variation within individuals and cultures. We present a theoretical model on the dynamic coexistence of cultural value systems (at the macro level) and parents' developmental goals (at the micro level). We contend that cultural values and developmental goals that have largely been classified as polar opposites may be viewed as conflicting, additive, or functionally dependent. Parents may view the developmental goal of autonomy as interfering with the goal of relatedness (and vice versa); parents may endorse both autonomy and relatedness; and parents may consider the developmental goal of relatedness to be a path to the goal of autonomy and/or autonomy to be a path to relatedness. These forms of coexistence are themselves dynamic, changing across situations, developmental time, and in response to social, political, and economic contexts.     

Infants born preterm and infants born full-term generate more selective leg joint movement during the scaffolded mobile task

Infants born very preterm (PT), prior to 32 weeks gestation, are at increased risk of developing cerebral palsy. Children with spastic cerebral palsy have impaired selective leg joint movement, which contributes to lifelong walking limitations. We investigated whether infants born PT generated more selective hip–knee joint movement (e.g., hip flexes as knee extends) while participating in a scaffolded mobile task. Infants born PT and infants born full-term (FT) at 4 months corrected age participated in a scaffolded mobile task for 2–3 consecutive days. The scaffolded mobile task required infants to raise their legs vertically over a virtual threshold. Three threshold heights (low, middle, and high) were used to test whether the middle and high heights encourage infants to move their legs more selectively. Fifteen infants born FT learned the task and showed more selective hip–knee movement at each of the three threshold heights on the day that they learned, compared with their baseline spontaneous kicking. Thirteen infants born PT learned the task and showed more selective hip–knee movement on their learning day, but only when the middle and high thresholds were used. The results show that the scaffolded mobile task effectively encouraged infants to generate more selective hip–knee joint movement.