Observatoires du développement, observatoires pour le développement

Le cas des migrations clandestines internationales éclaire le conflit entre les définitions de l'espace et du temps des acteurs et des analystes. La relativité des distinctions spatiales officielles s'allie à la relativité de la durée ou de la récurrence des migrations pour faire que mesurer les migrations et retrouver les migrants constituent des tâches distinctes. On retrouve donc ici la richesse du contraste entre les définitions objectives et subjectives du continuum spatio-temporel et la nécessité d'adapter l'instrument aux propriétés spécifiques du phénomène dont on veut rendre compte. De là, la complexité de la distinction entre les notions de territoire et de réseau, ou encore entre les notions de temps universel et de cycle de vie. Il en résulte qu'une analyse ne peut donner des résultats précis que si elle repose sur des modes différenciés, les uns privilégiant les inventaires, les autres les flux et que si elle implique le mélange de données venant de sources distinctes. L'adaptation d'instruments de mesure aux variations de durée, de direction, d'étapes intermédiaires et de taille des unités migrantes représente une innovation susceptible d'être généralisée à d'autres contextes. (Résumé d'auteur

Effective multi-tier supply chain management for sustainability

Sustainability issues pervade the supply chain deep into the recesses of various global regions and resources. Supply chains can become quite complex as they form multiple tiers of organizations and across networks. Solving anthropocentric pressures on the environment and human society means compelling supply chains to alleviate their environmental and social burdens. The strategic and operational complexities of multi-tier supply chain sustainability are transcendent. Addressing these concerns is still in its relative infancy amongst business, engineering, and production economics solutions. It is within this environment that this special issue in the International Journal of Production Economics advances this important research stream. Twenty-three articles using multiple methodologies, theories, and developments provide insights, clarifications and potential solutions to some of the most pernicious problems of multi-tier sustainable supply chains. This editorial overviews the various contentions, study interrelationships, whilst providing some future research directions

In Silico analysis of Gastric carcinoma Serial Analysis of Gene Expression libraries reveals different profiles associated with ethnicity

Worldwide gastric carcinoma has marked geographical variations and worse outcome in patients from the West compared to the East. Although these differences has been explained by better diagnostic criteria, improved staging methods and more radical surgery, emerging evidence supports the concept that gene expression differences associated to ethnicity might contribute to this disparate outcome. Here, we collected datasets from 4 normal and 11 gastric carcinoma Serial Gene Expression Analysis (SAGE) libraries from two different ethnicities. All normal SAGE libraries as well as 7 tumor libraries were from the West and 4 tumor libraries were from the East. These datasets we compare by Correspondence Analysis and Support Tree analysis and specific differences in tags expression were identified by Significance Analysis for Microarray. Tags to gene assignments were performed by CGAP-SAGE Genie or TAGmapper. The analysis of global transcriptome shows a clear separation between normal and tumor libraries with 90 tags differentially expressed. A clear separation was also found between the West and the East tumor libraries with 54 tags differentially expressed. Tags to gene assignments identified 15 genes, 5 of them with significant higher expression in the West libraries in comparison to the East libraries. qRT-PCR in cell lines from west and east origin confirmed these differences. Interestingly, two of these genes have been associated to aggressiveness (COL1A1 and KLK10). In conclusion we found that in silico analysis of SAGE libraries from two different ethnicities reveal differences in gene expression profile. These expression differences might contribute to explain the disparate outcome between the West and the East

STK39 polymorphisms and blood pressure: an association study in British Caucasians and assessment of cis-acting influences on gene expression

<p>Abstract</p> <p>Background</p> <p>Blood pressure (BP) has significant heritability, but the genes responsible remain largely unknown. Single nucleotide polymorphisms (SNPs) at the <it>STK39 </it>locus were recently associated with hypertension by genome-wide association in an Amish population; <it>in vitro </it>data from transient transfection experiments using reporter constructs suggested that altered <it>STK39 </it>expression might mediate the effect. However, other large studies have not implicated <it>STK39 </it>in hypertension. We determined whether reported SNPs influenced <it>STK39 </it>expression <it>in vivo</it>, or were associated with BP in a large British Caucasian cohort.</p> <p>Methods</p> <p>1372 members of 247 Caucasian families ascertained through a hypertensive proband were genotyped for reported risk variants in <it>STK39 </it>(rs6749447, rs3754777, rs35929607) using Sequenom technology. MERLIN software was used for family-based association testing. <it>Cis</it>-acting influences on expression were assessed <it>in vivo </it>using allelic expression ratios in cDNA from peripheral blood cells in 35 South African individuals heterozygous for a transcribed SNP in <it>STK39 </it>(rs1061471) and quantified by mass spectrometry (Sequenom).</p> <p>Results</p> <p>No significant association was seen between the SNPs tested and systolic or diastolic BP in clinic or ambulatory measurements (all p > 0.05). The tested SNPs were all associated with allelic expression differences in peripheral blood cells (p < 0.05), with the most significant association for the intronic SNP rs6749447 (P = 9.9 × 10^-4). In individuals who were heterozygous for this SNP, on average the G allele showed 13% overexpression compared to the T allele.</p> <p>Conclusions</p> <p><it>STK39 </it>expression is modified by polymorphisms acting in <it>cis </it>and the typed SNPs are associated with allelic expression of this gene, but there is no evidence for an association with BP in a British Caucasian cohort.</p

Human Tra2 proteins jointly control a CHEK1 splicing switch among alternative and constitutive target exons

Alternative splicing—the production of multiple messenger RNA isoforms from a single gene—is regulated in part by RNA binding proteins. While the RBPs transformer2 alpha (Tra2α) and Tra2β have both been implicated in the regulation of alternative splicing, their relative contributions to this process are not well understood. Here we find simultaneous—but not individual—depletion of Tra2α and Tra2β induces substantial shifts in splicing of endogenous Tra2β target exons, and that both constitutive and alternative target exons are under dual Tra2α–Tra2β control. Target exons are enriched in genes associated with chromosome biology including CHEK1, which encodes a key DNA damage response protein. Dual Tra2 protein depletion reduces expression of full-length CHK1 protein, results in the accumulation of the DNA damage marker γH2AX and decreased cell viability. We conclude Tra2 proteins jointly control constitutive and alternative splicing patterns via paralog compensation to control pathways essential to the maintenance of cell viability

Interpreting changes in measles genotype: the contribution of chance, migration and vaccine coverage

<p>Abstract</p> <p>Background</p> <p>In some populations, complete shifts in the genotype of the strain of measles circulating in the population have been observed, with given genotypes being replaced by new genotypes. Studies have postulated that such shifts may be attributable to differences between the fitness of the new and the old genotypes.</p> <p>Methods</p> <p>We developed a stochastic model of the transmission dynamics of measles, simulating the effects of different levels of migration, vaccination coverage and importation of new genotypes on patterns in the persistence and replacement of indigenous genotypes.</p> <p>Results</p> <p>The analyses illustrate that complete replacement in the genotype of the strain circulating in populations may occur because of chance. This occurred in >50% of model simulations, for levels of vaccination coverage and numbers of imported cases per year which are compatible with those observed in several Western European populations (>80% and >3 per million per year respectively) and for the given assumptions in the model.</p> <p>Conclusion</p> <p>The interpretation of genotypic data, which are increasingly being collected in surveillance programmes, needs to take account of the underlying vaccination coverage and the level of the importation rate of measles cases into the population.</p