Measuring the Effects of Stress and Social Networks on the Health of Canadians

We analyze the impact of networks and stress on the general and mental health of men and women aged 25 to 59 using data from the Canadian 2008 General Social Survey on Social Networks. Controlling for demographic and other variables, we examine the effects on health of social network types (family vs. friends), size, strength (frequency of contact) and diversity, and the interaction of these network variables with stress. We largely find the expected health benefits of network size, strength and diversity. Nonetheless, we also find diminishing health returns at higher levels of the network measures. The general health of men and women, for example, benefits from increasing size of family network, but such benefit decreases after a certain size. Likewise, increases in friend and family network sizes have positive but diminishing returns on men’s mental health. As expected, stress negatively impacts the general and mental health of men and women but social networks can buffer some of the negative effects. The negative effect of stress on men’s mental health is lessened with a more diverse network. Similarly, the negative effect of stress on women’s mental health decreases with larger network of friends. However, in the case of general health, men with higher stress have worsening health if they are in more diverse networks.     

Stable singular or negative stiffness systems in the presence of energy flux

We report stable systems which exhibit quasistatic stiffness that can be negative or tend to infinity without external constraint. They are based on coupled fields in the non-equilibrium presence of energy flux that is modulated by force. They evade thermodynamic restrictions by relaxing a restrictive assumption: equilibrium. Negative values of physical properties, including compressibility and heat capacity, are considered forbidden in classical thermodynamics; such analyses provide bounds on the stiffness and other properties of multiphase materials. Stable negative and singular stiffness is demonstrated experimentally in a piezoelectric system and in a thermoelastic granular material. Coupled fields occur naturally under a wide range of conditions and form the basis for many forms of technology including sensors, actuators, and electric coolers. Because all materials exhibit at least one coupled field effect, the concept is broadly general and is applicable to attaining extreme values of any physical property e.g. stiffness, permittivity, piezoelectricity.     

Social Capital and Economic Integration of Visible Minority Immigrants in Canada

On the basis of the 2002 Ethnic Diversity Survey, we study the role of human and social capital in explaining the personal earnings of foreign born persons working full-time, aged 25–64 years. The income differences associated with given visible minority categories are reduced after controls for human and social capital, but the differences remain significant, especially for men and for all but the Chinese category. Among the human capital factors, education and speaking English or French at home are positively related with earnings, while having the highest degree or diploma from outside of Canada is negative for all groups, although not statistically significant. Among the social capital considerations, trust was associated with higher income, while lack of participation in community organizations was an earnings disadvantage. Counter to expectations, individualization, or weak bonding and weak bridging ties, was associated with higher income, for men and for the other/multiple visible minorities and white immigrants.     

Parenting Intervention to Reduce Attention and Behavior Difficulties in Preschoolers: A CUIDAR Evaluation Study

In this study, we evaluated CUIDAR, a program that provides community-based 10-week parent training to reduce attention and behavior problems in preschool children. We recruited 154 predominantly low-income and Latino preschoolers and their parents to participate in this evaluation study. We collected data prior to and immediately following intervention and one year later. At the time of follow-up, we also recruited 15 parents who had initially enrolled, but never participated in the program to serve as a comparison group for a limited set of analyses. From pre to post intervention, we observed significant, positive changes in eight out of ten measured parenting behaviors. From pre intervention to follow-up, improvements in the use of transitional statements and planning ahead were significant. Children’s SDQ Total Difficulties scores significantly decreased from pre to post intervention (d = .36), and we observed significant, positive changes in all SDQ subscales. From pre intervention to follow-up, children’s SDQ Total Difficulties scores significantly decreased (d = .71) and all SDQ subscales reflected significant, positive changes. We observed no significant differences in reported barriers to participation between parents who participated in the program and those who enrolled, but never participated. Intervention gains were moderated by several factors, including history of out-of-home care and family structure. Our results should be interpreted cautiously because not all analyses included a comparison group, and a randomized trial of CUIDAR effectiveness is still needed.     

Fertility Behavior of Immigrants in Canada: Converging Trends

Using data from the 2002 Ethnic Diversity Survey, this paper compares fertility behavior across three immigrant generations: foreign born, second generation, the population of third or more generations. Several important findings emerge from this study. First, consistent with previous studies, we have documented higher fertility for the foreign born and lowest for the second generation, but these differences are no longer statistically significant after controls for sociodemographic factors. The differentials by age, with higher fertility for those who arrived after age 15, also disappear after controls. These findings support the hypothesis that it is the sociodemographic characteristics of the immigrant generations that matter rather than the generational status itself. The controls did not eliminate the differentials by visible minority status, which show highest fertility in the Black population and lowest in the Chinese population. Consistent with the finding that lowest fertility occurs among persons who are least acculturated, we suggest that the relative opportunity structures of given minority groups may be part of the explanation.     

Proof and Dialogue in Aristotle

Jan ?ukasiewicz’s analysis of Aristotle’s syllogism drew attention to the nature of syllogisms as conditionals rather than premise-conclusion arguments. His further idea that syllogisms should be understood as theorems of an axiom system seems a step too far for many logicians. But there is evidence to suggest that Aristotle’s syllogism was to regularise some of the steps made in ‘dialogue games.’ This way of seeing the syllogism is explored in the framework of modern formal dialogue systems. A modern formal syllogistic game, DLSyll, is set out and analysed in use.