Exact estimation of multiple directed acyclic graphs

This paper considers structure learning for multiple related directed acyclic graph (DAG) models. Building on recent developments in exact estimation of DAGs using integer linear programming (ILP), we present an ILP approach for joint estimation over multiple DAGs. Unlike previous work, we do not require that the vertices in each DAG share a common ordering. Furthermore, we allow for (potentially unknown) dependency structure between the DAGs. Results are presented on both simulated data and fMRI data obtained from multiple subjects.     

The Effect of Mask Use on the Spread of Influenza During a Pandemic

Face masks have traditionally been used in general infection control, but their efficacy at the population level in preventing transmission of influenza viruses has not been studied in detail. Data from published clinical studies indicate that the infectivity of influenza A virus is probably very high, so that transmission of infection may involve low doses of virus. At low doses, the relation between dose and the probability of infection is approximately linear, so that the reduction in infection risk is proportional to the reduction in exposure due to particle retention of the mask. A population transmission model was set up to explore the impact of population‐wide mask use, allowing estimation of the effects of mask efficacy and coverage (fraction of the population wearing masks) on the basic reproduction number and the infection attack rate. We conclude that population‐wide use of face masks could make an important contribution in delaying an influenza pandemic. Mask use also reduces the reproduction number, possibly even to levels sufficient for containing an influenza outbreak.     

On the Correspondence Between Physiological and Nonverbal Responses: Nonverbal Behavior Accompanying Challenge and Threat

Little is known regarding the covariance between physiological and nonverbal responses to “stressful” situations. We argue that physiological markers are especially likely to be accompanied by psychologically-meaningful nonverbal behavior. Within “stressful” motivated performance situations, complex patterns of cardiovascular (CV) reactivity mark challenge and threat motivational states relevant to confidence. We expected the CV challenge and threat markers to be distinguished on the basis of facial and vocal confidence. In a test of this hypothesis, participants’ cardiovascular (CV) responses were recorded during a videotaped social interaction. As expected, the CV challenge marker was associated with more vocal confidence and less facial confidence than the CV threat marker. These findings are related to the complexity of human responses to motivated performances.     

The resource recovery level decision for end-of-life products

Resource recovery from end-of-life (EOL) products is becoming increasingly engaged in by companies as a response to customer, consumer, government and social pressures, the electronics industry cites competitor pressures as being the main driver of EOL product take-back and recovery. Recovery can occur at three levels; i.e. product, part and material. Each of these options has economic and environmental advantages and disadvantages depending on the product type and a host of other influencing factors. The work described in this paper supports the decision as to the most favourable route from a cost and value perspective, a software model that provides such support is also described.     

Modelling end-of-life product recovery chains - a case study

European Union legislation, and existing national legislation of many European countries, mandates that manufacturers take back and recover their electronic and electrical equipment. If manufacturers are to comply with legislation, models need to be developed for these activities. Whilst infrastructural and technological deficits exist and must be addressed, so too must the organization of recovery, from a business perspective. In this paper, models of resource recovery are presented and a case study described.     

Firm-level social returns to education

Do workers benefit from the education of their co-workers? We examine this question first by introducing a model of learning, which argues that educated workers may transfer part of their general skills to uneducated workers, and then by examining detailed matched employer–employee panel data from Portugal. We find evidence of large firm-level social returns (between 14% and 23%), much larger than standard estimates of private returns, and of significant returns accruing to less educated workers but not to their more educated colleagues.     

Using critical social theory to develop a conceptual framework for comparative social work

This paper sets out a conceptual framework for comparing and contrasting social work within nation-states and across international boundaries. The framework is "situated" theoretically within a (late)modernist understanding of events within advanced capitalism and draws primarily on Habermas' critical social theory. The authors apply this framework to explicate the development of social work in Northern Ireland, a region in which high levels of political conflict mark it out as a site of local, national and international interest. It is suggested that the ideas developed from the case study have relevance for the social professions in other countries, particularly where social conflict is in evidence.