Sensitivity Analyses of the Economic and Economic Statistical Designs of the Multivariate Synthetic T2 Chart

This article performs a sensitivity analyses of the synthetic T² chart using fractional factorial design, which integrates the interaction effects. We are interested in the effects of the input parameters on the optimal cost, chart's parameters, and average run lengths. We also look at the input parameters responsible for the increase in cost and improvement in statistical performance under statistical constraints, and investigate how the input parameters influence the binding effect of the statistical constraints. The sensitivity analyses of the synthetic T² chart are compared with that of the Hotelling's T² chart, and parameters responsible for the cost advantage of the synthetic T² chart are identified.     

International Migration and the Demographic Transition: A Two‐Way Interaction

The paper explores the relationship between the demographic transition and international migration, that is, between population dynamics and direct connectivity between peoples. The first part examines how ideas conveyed by migrants to non‐migrants of their community of origin are susceptible to impact on practices that lead to the reduction of birth rates in source countries of migration and concludes that international migration may be one of the mechanisms through which demographic transition is disseminated. The second part shows that declining birth rates in origin countries generate a new profile of the migrant and suggests that future migrants will typically leave no spouses or children in the home country and therefore their objective will no longer be to improve the family’s standing at home for the mere reason that there is no longer such a family, but to increase opportunities for themselves. Migration policies of origin countries on remittances as well as those of destination countries on family reunification will have to be reconsidered.     

Voting under the threat of secession: accommodation versus repression

We build a simple model of secession crises where a majority of voters may wish to accommodate a minority in order to prevent a secession attempt. We first show the existence of a majority voting equilibrium, where the median voter is decisive and most prefers a government’s type that is biased in favor of the minority. We propose a measure of the secession risk at equilibrium, which depends upon the comparison of the willingness to secede by the minority and to accommodate by the majority. We show that focusing only on the willingness to secede, as previous literature has done, is misleading when studying the impact on the risk of secession of the size of the minority region, the probability that a secession attempt by the minority is successful, and the cultural heterogeneity in the country.     

Pride and popcorn: consuming the idea of community at film screenings in the Turkish diaspora

A range of studies have revealed the interrelatedness of identity construction, community formation and media among diasporas, mostly focusing on domestic contexts. Seeking to add further nuance to the understanding of the social lives of diasporas, we concentrate on media culture in the public environment of the film theatre. The significance of diasporic film consumption is investigated through a local audience study of Turkish film screenings in Antwerp. The phenomenon of the screenings was analysed through a multi-method approach, including 536 questionnaires among audiences, 19 in-depth interviews and 3 group interviews, along with previous findings (on distribution and exploitation) of the same project. The results show that Turkish films are almost exclusively attended by people with Turkish roots, creating a Turkish diasporic space within the boundaries of the urban and the public. The audience study shows that the screenings fulfil a major social role but also affect understandings of community.     

Ecological corridors also operate in an urban matrix: A test case with garden shrews

The fragmentation of landscapes, induced by the growing urbanisation, is a major cause of biodiversity loss. Ecological corridors are landscape elements that make up for the negative effects of habitat fragmentation in agricultural or natural landscapes. However, their effectiveness have been rarely assess in an urban context. To do so, we analysed shrews in woodlots, corridors and domestic gardens that are connected or disconnected from a corridor. Indeed, these mammals are very sensitive to fragmentation and could play an important ecological role even in small and isolated areas such as domestic gardens. Ninety-seven shrews, from three species were trapped. In our study, Sorex coronatus, Sorex minutus and Crocidura russula were not widely distributed and mainly occurred in woodlots, corridors and connected gardens. In gardens, shrew occurrences were mainly determined by landscape configuration with negative effects of the distance to the corridor and the distance to the woodlot, stronger for C.russula than Sorex species. At the local scale, garden management and vegetation showed a positive effect mainly for Sorex species. The quality of gardens seems good enough to permit the co-occurrence of several species of shrews and thus competition was not identified as a major process for determining the occurrence. We showed that, as in other ecosystems, ecological corridors in urban context can play an effective role for the distribution of organisms with low dispersal capabilities and should be develop in planning strategies.     

Inference of a hidden spatial tessellation from multivariate data: application to the delineation of homogeneous regions in an agricultural field

Summary.  In a precision farming context, differentiated management decisions regarding fertilization, application of lime and other cultivation activities may require the subdivision of the field into homogeneous regions with respect to the soil variables of main agronomic significance. The paper develops an approach that is aimed at delineating homogeneous regions on the basis of measurements of a categorical and quantitative nature, namely soil type and resistivity measurements at different soil layers. We propose a Bayesian multivariate spatial model and embed it in a Markov chain Monte Carlo inference scheme. Implementation is discussed using real data from a 15-ha field. Although applied to soil data, this model could be relevant in areas of spatial modelling as diverse as epidemiology, ecology or meteorology.     

Benchmark Dose Calculations for Methylmercury-Associated Delays on Evoked Potential Latencies in Two Cohorts of Children

Delays in evoked potential latencies were observed at increased exposures to methylmercury from seafood in two cohorts of children. Because this outcome parameter appeared to be virtually independent of confounders, including cultural differences, a joint analysis of benchmark doses was carried out. Comparable cohort members included 382 Faroese and 113 Madeiran children without middle ear infection or neurological disease at age seven years. Maternal hair-mercury concentrations at parturition in the Faroese cohort ranged from 0.6 to 39.1 microg/g (geometric average, 4.49 microg/g). In Madeira, mothers who had not changed their diet since pregnancy had current hair-mercury concentrations ranging from 1.1 to 54.4 microg/g (geometric average 10.14 microg/g). The mercury-associated delay in peak III latencies at two frequencies (20 and 40 Hz) showed similar regression equations in the two groups of children, and benchmark dose calculations were therefore carried out for the two groups separately and jointly. For a doubling of a 5% prevalence of abnormal results of the peak III latencies at 40 Hz in a linear dose-response model, the benchmark dose for the maternal hair-mercury concentration was 8.79 microg/g for the Faroese children; 8.04 microg/g for the Madeiran children; and 9.46 microg/g for both groups. Results were similar for the 20 Hz condition. Benchmark dose results were substantially lower using a logarithmic or square root curve function, although the difference in fit between the curves was far from statistically significant. The benchmark results using evoked potential latencies are in close agreement with results based on neuropsychological test performance.