An exact approach for the balanced <Emphasis Type="Italic">k</Emphasis>-way partitioning problem with weight constraints and its application to sports team realignment

In this work a balanced k-way partitioning problem with weight constraints is defined to model the sports team realignment. Sports teams must be partitioned into a fixed number of groups according to some regulations, where the total distance of the road trips that all teams must travel to play a double round robin tournament in each group is minimized. Two integer programming formulations for this problem are introduced, and the validity of three families of inequalities associated to the polytope of these formulations is proved. The performance of a tabu search procedure and a branch and cut algorithm, which uses the valid inequalities as cuts, is evaluated over simulated and real-world instances. In particular, an optimal solution for the realignment of the Ecuadorian football league is reported and the methodology can be suitable adapted for the realignment of other sports leagues.     

Perceived Corruption and Individuals’ Life Satisfaction: The Mediating Role of Institutional Trust

Social Indicators Research - Corruption degrades the quality of institutions, increases economic inequality and limits growth. Recent studies indicate that corruption is also associated with lower...     

Whither the evolution of the contemporary social fabric? New technologies and old socio‐economic trends

This article considers whether societies are witnessing another industrial revolution in the light of an assessment of the impact of technological change on today's socio‐economic fabric, especially with respect to employment, income distribution, working conditions and labour relations. The authors argue that the processes of innovation and the spread of what they term “intelligent automation” are likely to exacerbate incumbent patterns of uneven income distribution and power, some of which existed well before the arrival of the technologies concerned, while others have emerged over the past 30 to 40 years. They venture to consider policy implications on the basis of such developments.     

Parental Linguistic Input and Its Relation to Toddlers’ Visual Attention in Joint Object Play: A Comparison Between Children with Normal Hearing and Children With Hearing Loss

Parent–child interactions are multimodal, often involving coordinated exchanges of visual and auditory information between the two partners. The current work focuses on the effect of children's hearing loss on parent–child interactions when parents and their toddlers jointly played with a set of toy objects. We compared the linguistic input received by toddlers with hearing loss (HL) and their chronological age‐matched (CA) and hearing age‐matched (HA) normal‐hearing peers. Moreover, we used head‐mounted eye trackers to examine how different parental linguistic input affected children's visual attention on objects when parents either led or followed children's attention during joint object play. Overall, parents of children with HL provided comparable amount of linguistic input as parents of the two normal‐hearing groups. However, the types of linguistic input produced by parents of children with HL were similar to the CA group in some ways and similar to the HA group in other ways. Interestingly, the effects of different types of linguistic input on extending the attention of children with HL qualitatively resembled the patterns seen in the CA group, even though the effects were less pronounced in the HL group. We discuss the implications of these results for our understanding of the reciprocal, dynamic, and multi‐factored nature of parent–child interactions.     

A Bayesian model for cross-study differential gene expression

In this paper we define a hierarchical Bayesian model for microarray expression data collected from several studies and use it to identify genes that show differential expression between two conditions. Key features include shrinkage across both genes and studies, and flexible modeling that allows for interactions between platforms and the estimated effect, as well as concordant and discordant differential expression across studies. We evaluated the performance of our model in a comprehensive fashion, using both artificial data, and a "split-study" validation approach that provides an agnostic assessment of the model's behavior not only under the null hypothesis, but also under a realistic alternative. The simulation results from the artificial data demonstrate the advantages of the Bayesian model. The 1 - AUC values for the Bayesian model are roughly half of the corresponding values for a direct combination of t- and SAM-statistics. Furthermore, the simulations provide guidelines for when the Bayesian model is most likely to be useful. Most noticeably, in small studies the Bayesian model generally outperforms other methods when evaluated by AUC, FDR, and MDR across a range of simulation parameters, and this difference diminishes for larger sample sizes in the individual studies. The split-study validation illustrates appropriate shrinkage of the Bayesian model in the absence of platform-, sample-, and annotation-differences that otherwise complicate experimental data analyses. Finally, we fit our model to four breast cancer studies employing different technologies (cDNA and Affymetrix) to estimate differential expression in estrogen receptor positive tumors versus negative ones. Software and data for reproducing our analysis are publicly available.     

2MTO,a new mapping tool to achieve lean benefits in high-variety low-volume job shops

This paper proposes the ‘Mapping Tool for Make-To-Order companies’ (2MTO), a new approach to map, analyse and achieve lean benefits in high-variety-low-volume job shops. The focus is, mainly, on the transitional phase from push to pull, when there is a compelling need to acquire a deep understanding of the current state of the system under analysis. Sometimes, in this initial phase, a pure pull approach cannot be developed and a job shop configuration must be maintained. If so, 2MTO allows selecting a suitable hybrid Production Planning and Control system to control Work-In-Process and to limit lead times, so as to quickly achieve lean benefits, without significantly altering the original layout. 2MTO is fully explained making reference to an Italian precision mechanic company, where the application of the method led to a successful implementation of a Workload Control system.     

Education,reputation or network? Evidence on migrant workers employability

The strong adverse selection that immigrants face in hosting labour markets may induce them to adopt some behaviours or signals to modify employers’ beliefs. Relevant mechanisms for reaching this purpose are personal reputation; exploiting ethnic networks deeply rooted in the hosting country; and high educational levels used as an indirect signal of productivity. On this last point, the immigrant status needs a stronger signal compared to that necessary for a native worker, and this may lead the immigrant to accept job qualifications which are lower than those achievable through the embodied educational level.The aim of the paper is to investigate whether the above mentioned mechanisms are adopted by immigrants in Italy, a crucial country for EU immigration flows, and if they are useful in increasing immigrants’ likelihood of employment. The empirical analysis has been conducted using the dataset from a national Labour Force Survey which provides information on thousands of documented immigrants. We estimate a logit model for immigrants’ likelihood of being employed, focusing on the above mentioned mechanisms: reputation, ethnic networks and educational level. Moreover we concentrate on the interaction effects of the mechanisms and investigate whether one of them wins on the others. Results show that each of the three mechanisms is statistically and economically significant and exerts positive influence: all factors contribute to increase the immigrant's probability of being employed. Anyway, a high level of education increases the probability of being employed more than the belonging to ethnic networks deeply rooted in Italy. The specific embodied capital of workers matter relatively more. This is relevant for labour public policies in this specific realm since the human capital lever is a possible direct target in various public policies and private human capital investments.     

Surveiller en éradiquant : l’importance des « médiateurs de la surveillance » et des réseaux informels dans la surveillance des risques sanitaires et environnementaux

Surveillance measures, now a major form of public action in relation to health and environmental risks, often rely on cooperation among parties with contradictory interests. This cooperation is analyzed in cases when neither coercion nor incentives suffice to obtain it. A study of an attack by a virus on crops has brought to light arrangements that contrast with the formal setup for surveillance. These arrangements made it possible for health-related information to circulate. They were facilitated by the activity of “surveillance mediators” who were able — thanks to their durable local roots and their technical qualifications — to relate to different social worlds. Light is thus shed on the need both to take into account the political nature of the data collected during surveillance activities and to examine the many forms they take — forms that are the very conditions for data collection.