Are measured school effects just sorting?: Causality and correlation in the National Education Longitudinal Survey

Youth who share a school and neighborhood often show similar levels of academic achievement, but some studies find all or most of this correlation is due to sorting (not causation). We analyze the National Education Longitudinal Survey (NELS) in three ways to decompose sorting versus causality: We first control for much richer measures of family background than other analysts have used. We next use characteristics of the students’ future high school as an instrument for family background (as future high school quality is correlated with unobserved family background but cannot cause junior high test scores). Finally, we use regression and semi-nonparametric matching methods to look at changes in test score when youth change schools. The results create a collage of evidence that a significant fraction of the correlation is causal.     

Representational Abilities and the Hearing Status of Child/Mother Dyads

Two representational abilities, expressive and receptive language and symbolic play, were assessed in multiple formats in hearing and deaf 2-year-old children of hearing and deaf mothers. Based on maternal report, hearing children of hearing and deaf mothers produced more words than deaf children of hearing mothers, hearing children of hearing mothers more words than deaf children of deaf mothers, and deaf children of deaf mothers more words than deaf children of hearing mothers. Based on experimenter assessments, hearing children in both groups produced and comprehended more words than deaf children in both groups. By contrast, no differences emerged among these groups in child solitary symbolic play or in child-initiated or mother-initiated child collaborative symbolic play; all groups also increased equivalently in symbolic play between solitary and collaborative play. Representational language and symbolic play were unrelated in hearing children of hearing mothers and in deaf children of deaf mothers, but the 2 abilities were associated in children in the 2 child/mother mismatched hearing status groups. These findings are placed in the context of a proposed developing modularity of verbal and nonverbal symbol systems, and the implications of hearing status in communicative exchanges between children and their mothers in diverse hearing and deaf dyads are explored.     

Cross-linguistic analysis of vocabulary in young children: spanish, dutch, French, hebrew, italian, korean, and american english

The composition of young children's vocabularies in 7 contrasting linguistic communities was investigated. Mothers of 269 twenty-month-olds in Argentina, Belgium, France, Israel, Italy, the Republic of Korea, and the United States completed comparable vocabulary checklists for their children. In each language and vocabulary size grouping (except for children just learning to talk), children's vocabularies contained relatively greater proportions of nouns than other word classes. Each word class was consistently positively correlated with every other class in each language and for children with smaller and larger vocabularies. Noun prevalence in the vocabularies of young children and the merits of several theories that may account for this pattern are discussed.     

The BASES expert statement on exercise therapy for people with chronic kidney disease

Chronic kidney disease (CKD) is becoming a serious health problem throughout the world and is one of the most potent known risk factors for cardiovascular disease, which is the leading cause of morbidity and mortality in this patient population. Physical inactivity has emerged as a significant and independent risk factor for accelerated deterioration of kidney function, physical function, cardiovascular function and quality of life in people in all stages of CKD. CKD specific research evidence, combined with the strong evidence on the multiple health benefits of regular and adequate amounts of PA in other cardiometabolic conditions, has resulted in physical inactivity being identified by national and international CKD clinical practice guidelines as one of the multiple risk factors that require simultaneous and early intervention for optimum prevention/management of CKD. Despite this realisation, physical inactivity is not systematically addressed by renal care teams. The purpose of this expert statement is therefore to inform exercise and renal care specialists about the clinical value of exercise therapy in CKD, as well as to provide some practical recommendations on how to more effectively translate the existing evidence into effective clinical practice.