Welfare Cost of Mobile Spectrum (Mis)allocation

Conditions under which spectrum is allocated are significant in determining the market structure in the telecom sector which in turn affects the prices and the quality of mobile services. In a more concentrated market, the quantity of spectrum is less diluted, and operators can offer higher quality to their customers; In a more competitive market, consumers can benefit from a lower price but at the expense of less quality for each operator. To address this trade-off, we first fit a demand model of mobile telecommunications services on a unique panel database of 23 European MNOs; we then conduct counterfactual simulations to measure the effect on consumer surplus of different schemes of spectrum allocation in Germany. Reallocating additional spectrum to three instead of four operators is consumer welfare improving as increasing prices is compensated by larger improvement in quality

Synthesis and Characterization of Advanced Carbon-Based Nanowires – Study of Composites Actuation Capabilities Containing These Nanowires as Fillers

International audienc

Pollutants in pet dogs: a model for environmental links to breast cancer

PURPOSE: Invasive breast carcinoma is the most common cancer in women as in non-ovariectomised pet dogs, which are already identified as a valuable spontaneous preclinical model for that disease. Geographical and time trends suggest that environmental factors may play an important role in the etiology and pathogenesis of breast cancer. Persistent organic pollutants (POPs) fit perfectly with these trends and are known to interact with hormonal receptors implicated in breast cancer subtyping. The aim of this innovating study was to evaluate the interest of the companion dog model in assessing chemical exposure and breast cancer associations, in order to identify common etiological features with the human disease in a context of comparative oncology. METHODS: We monitored a hundred of molecules belonging to a large panel of POPs (dioxins, dioxin-like and non dioxin-like polychlorobisphenyls, organochlorine pesticides, brominated flame retardants, perfluorinated alkylated substances) in companion dogs diagnosed for mammary adenocarcinoma (n = 54) and non cancer controls (n = 47). RESULTS: All targeted chemical families were able to be detected in canine samples. We identified pollutants associated with mammary cancer belonging to the dioxin like-PCB family (notably PCB-118, -156, -105, -114) that were already pointed out in human epidemiological studies on breast cancer, and that fit with the fundamental role of the Aryl Hydrocarbon Receptor in the promotion of breast cancer. CONCLUSIONS: Similarities observed in the spontaneous dog model are very helpful to progress in interpretation of human breast cancer-environment relationships. This study provides a new insight focusing on this discrete but recurrent signature

In vivo comparison of the proangiogenic properties of chlordecone and three of its dechlorinated derivatives formed by in situ chemical reduction

In situ chemical reduction (ISCR) has been identified as a possible way for the remediation of soils contaminated by chlordecone (CLD). Evidences provided by the literature indicate an association between the development of prostate cancer and CLD exposure (Multigner et al. 2010). In a previous in vitro study, we demonstrated that the two main dechlorinated CLD derivatives formed by ISCR, CLD-1Cl, and CLD-3Cl have lower cytotoxicity and proangiogenic properties than CLD itself (Legeay et al. 2017). By contrast, nothing is known on the in vivo proangiogenic effect of these dechlorinated derivatives. Based on in vitro data, the aims of this study were therefore to evaluate the in vivo influence of CLD and three of its dechlorinated metabolites in the control of neovascularization in a mice model of prostate cancer. The proangiogenic effect of CLD and three of its dechlorinated derivatives, CLD-1Cl, CLD-3Cl, and CLD-4Cl, was evaluated on a murine model of human prostate tumor (PC-3) treated, at two exposure levels: 33 μg/kg and 1.7 μg/kg respectively reflecting acute and chronic toxic exposure in human. The results of serum measurements show that, for the same ingested dose, the three metabolite concentrations were significantly lower than that of CLD. Dechlorination of CLD lead therefore to molecules that are biologically absorbed or metabolized, or both, faster than the parent molecule. Prostate tumor growth was lower in the groups treated by the three metabolites compared to the one treated by CLD. The vascularization measured on the tumor sections was inversely proportional to the rate of dechlorination, the treatment with CLD-4Cl showing no difference with control animals treated with only the vehicle oil used for all substances tested. We can therefore conclude that the proangiogenic effect of CLD is significantly decreased following the ISCR-resulting dechlorination. Further investigations are needed to elucidate the molecular mechanisms by which dechlorination of CLD reduces proangiogenic effects in prostate tumor

Electrical and Piezoelectric Behavior of Polyamide/PZT/CNT Multifunctional Nanocomposites

Three-phase polyamide 11 (PA 11)/lead zirconate titanate (PZT)/carbon nanotubes (CNT) composites are elaborated by extrusion. The influence of inorganic particles on the electrical properties of conductive composites and the influence of conductive particles on the ferroelectric properties of organic/inorganic composites are both studied. Inorganic particles do not modify the establishment of the electrical percolation path of CNTs either regarding the percolation threshold value or the conductivity reached above this insulator–conductive transition. The dielectric permittivity of twophase PA 11/PZT composites is improved with the addition of only 0.2% in volume of CNTs. This three-phase composite could be proposed for actuation, energy harvesting and damping performances enhancement