Joint Attention,Self‐Recognition,and Neurocognitive Function in Toddlers

Recent studies have attempted to understand the processes involved in joint attention because of its relevance to both atypical and normal development. Data from a recent study of young children with autism suggests that performance on a delay nonmatch to sample (DNMS) task associated with ventromedial prefrontal functions, but not an A‐not‐B/delayed response task associated with dorsolateral prefrontal cortex, was related to joint attention skills (Dawson et al., 2002). Recent research also suggests that joint attention is associated with dorsalmedial brain systems linked to self‐monitoring (Mundy, 2003). This study investigated the relations among joint attention, DNMS, and self‐recognition performance in a longitudinal study of 39 normally developing toddlers from 14 to 18 months. The results indicated that development on the DNMS and self‐recognition tasks, but not a means end task, predicted joint attention at 18 months. Further analysis showed that the model was only significant for initiating joint attention (IJA). The implications of these results for the neuro‐development of IJA are discussed.     

Seven ways of causing the less developed countries' population problem to disappear—in theory

The ways to minimize the difficulties due to population and its growth to be found in current literature have been grouped under seven heads in a far from exhaustive listing:

1. Apply the perspective of rates rather than absolute numbers.
2. Annul the direct negative effects of population with surprising positive indirect effects.
3. Show that neither land nor physical capital is important for development; only labour and human capital count.
4. Exhibit past record of zero correlation between income increase and population increase.
5. Calculate net externality of population increase, but underestimate the externalities falling on women and especially on later generations.
6. Make models of the economy omitting the environment, i.e. implicitly assume the environment is infinite.
7. When all else fails declare that population growth is not bad in itself, but that all evils are due to bad policies—economic, ecological, or urban. Marx thought population growth damaging only under capitalism; now population growth is said to be made innocuous by capitalism.

     

Economic integration and labor flows: stage migration in farm labor markets in Mexico and the United States

"This article examines the probable effects of the North American Free Trade Agreement (NAFTA) on migration from Mexico to the United States, disputing the view that expansion of jobs in Mexico could rapidly reduce undocumented migration. To the extent that NAFTA causes Mexican export agriculture to expand, migration to the United States will increase rather than decrease in the short run. Data collected in both California and the Mexican State of Baja California show that indigenous migrants from southern Mexico typically first undertake internal migration, which lowers the costs and risks of U.S. migration. Two features of employment in export agriculture were found to be specially significant in lowering the costs of U.S. migration: first, working in export agriculture exposes migrants to more diverse social networks and information about U.S. migration; second, agro-export employment in northern Mexico provides stable employment, albeit low-wage employment, for some members of the family close to the border (especially women and children) while allowing other members of the family to assume the risks of U.S. migration."     

Who killed change management?

A story is told here of an investigation into change management's apparent death, provoked by the dubious business novel Who Killed Change [Blanchard, K., J. Britt, P. Zigarmi, and J. Hoekstra. 2009. Who Killed Change? Solving the Mystery of Leading People Through Change. London: Harper Collins Publishers]. The story is told over eight chapters inviting you to investigate competing explanations for the death of change management using the structure of the story arc: stasis, trigger, quest, surprise, critical choice, climax, reversal and resolution. An annoying voice (sometimes interior monologue and at other times dialogue) of another reader keen to inform and frame your understanding of the status of change management remains ever present. The case is solved with the story's resolution providing insights into advantages of investigating over literature reviewing, the problematic/masculine nature of murder metaphors, the academic potential of story arcs and the mystery which characterises organizational change.     

Disruption in Parental Co-habitation and its Effects on Short-Term,Medium-Term,and Long-Term Outcomes of Adolescents

In this paper the relationships between a disruption in parental co-habitation and various categories of adolescent outcomes over multiple time horizons are explored. Using data from the National Longitudinal Study of Adolescent Health (Add Health), we estimated the effects of a change from living with both parents to just one, on academic and employment outcomes, the likelihood to indulge in risky behaviors, mental health outcomes and body mass index measures, from less than 1 year to over 14 years after the change. Propensity score matching methods were used to control for individual characteristics and pre-existing differences in the family environment that may increase the chances of separation, and the results are compared to those obtained using ordinary least squares or probit methods. Results showed evidence of adverse effects of living with one parent in the short term, medium term and long term. Adolescents living with one parent had lower academic achievement in all term lengths, poor mental health in the short to medium term, and were more likely to engage in risky behaviors in the medium to long term.     

Using a “child's‐eye view” of social success to understand the importance of school readiness at the transition to formal schooling

Recent research into school readiness has highlighted the importance of not only children's cognitive and socio‐emotional skills, but also the degree to which they have family support in the home. The current study examines the association between social success upon school entry and teacher‐ratings of school readiness as assessed by the Brief Early Skills and Support Index (BESSI), controlling for language ability. Importantly, social success was assessed using a “child's‐eye view” with peer‐reported assessments of both social preference and reciprocated friendships. A total of 244 children (131 boys, M_age = 61 months, SD = 4.78 months) in their first year of formal schooling participated. Child school readiness was found to be important for social preference, with the association being more marked for boys versus girls. Family support was the only independent predictor of children's reciprocated friendships. The use of the BESSI, with its broad scope compared to other measures of school readiness, highlights the importance of focusing both on a child's cognitive and socio‐emotional skills at school entry and their family support when exploring the association of school readiness to children's social success at the transition to formal schooling.     

Estimation of the cumulative incidence function under multiple dependent and independent censoring mechanisms

Competing risks occur in a time-to-event analysis in which a patient can experience one of several types of events. Traditional methods for handling competing risks data presuppose one censoring process, which is assumed to be independent. In a controlled clinical trial, censoring can occur for several reasons: some independent, others dependent. We propose an estimator of the cumulative incidence function in the presence of both independent and dependent censoring mechanisms. We rely on semi-parametric theory to derive an augmented inverse probability of censoring weighted (AIPCW) estimator. We demonstrate the efficiency gained when using the AIPCW estimator compared to a non-augmented estimator via simulations. We then apply our method to evaluate the safety and efficacy of three anti-HIV regimens in a randomized trial conducted by the AIDS Clinical Trial Group, ACTG A5095.