Earnings and Percentage Female: A Longitudinal Study

Comparable worth is designed to raise the earnings of women assumed to be penalized for working in female-dominated occupations. Comparable worth advocates assume that the relation between earnings and percentage female in an occupation is due to crowding or other forms of discrimination. An alternative explanation is that the relation stems from women freely choosing different occupations. In other words, preferences are an omitted variable. In our study, we first replicate previous research that has used cross-sectional data to find a negative relation between earnings and percentage female (in an occupation) for both men and women. However, using longitudinal data to control for time-invariant omitted variables, we find that while men\u27s estimated penalty is not reduced, the percentage female penalty falls substantially for women and is not statistically significant. These results imply that estimates of the percentage female effect based on cross-sectional data may be inflated for women. An exception to this general finding is that women with intermittent labor force participation do experience a sizeable penalty for working in female-dominated occupations. Hence, this pattern of results suggests that a comparable worth policy would most likely benefit women with discontinuous employment--perhaps an unintended outcome

Spectrum Sensing of DVB-T2 Signals using a Low Computational Noise Power Estimation

© 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted ncomponent of this work in other works.Cognitive radio is a promising technology that answers the spectrum scarcity problem arising from the proliferation of wireless networks and mobile services. In this paper, spectrum sensing of digital video broadcasting-second generation terrestrial (DVB-T2) signals in AWGN, WRAN and COST207 multipath fading environment are considered. ED is known to achieve an increased performance among low computational complexity detectors, but it is susceptible to noise uncertainty. Taking into consideration the edge pilot and scattered pilot periodicity in DVB-T2 signals, a low computational noise power estimator is proposed. Analytical forms for the detector are derived. Simulation results show that with the noise power estimator, ED significantly outperforms the pilot correlation-based detectors. Simulation also show that the proposed scheme enables ED to obtain increased detection performance in multi-path fading environments. Moreover, based on this algorithm a practical sensing scheme for cognitive radio networks is proposed.Peer reviewedFinal Accepted Versio

Etude de l'interface milieu granulaire-paroi rugueuse par approches expérimentale et numérique - Application aux bétons

International audienceLa qualité des parements, les poussées et le pompage des bétons sont liés au frottement du béton contre la paroi. L'objectif de cette étude est de comprendre les phénomènes se produisant à l'interface béton frais-paroi à l'échelle des grains. L'étude de l'interface a été réalisée sur un modèle simplifié qui consiste à déplacer une paroi rugueuse sous un empilement monodisperse confiné. Des expériences sur un dispositif expérimental et des simulations sur un modèle numérique aux éléments discrets ont été menées. Les résultats expérimentaux montrent qu'à proximité de l'interface, les mouvements de billes dépendent de la rugosité de la paroi. De même, l'étude numérique montre que la force de frottement et l'état de cisaillement près de l'interface sont étroitement liés aux caractéristiques de la paroi rugueuse

Modeling circadian clock-cell cycle interaction effects on cell population growth rates

Accepted for publication in Journal of Theoretical Biology, post-print versionInternational audienceThe circadian clock and the cell cycle are two tightly coupled oscillators. Recent analytical studies have shown counter-intuitive effects of circadian gating of the cell cycle on growth rates of proliferating cells which cannot be explained by a molecular model or a population model alone. In this work, we present a combined molecular-population model that studies how coupling the circadian clock to the cell cycle, through the protein WEE1, affects a proliferating cell population. We show that the cell cycle can entrain to the circadian clock with different rational period ratios and characterize multiple domains of entrainment. We show that coupling increases the growth rate for autonomous periods of the cell cycle around 24 h and above 48 h. We study the effect of mutation of circadian genes on the growth rate of cells and show that disruption of the circadian clock can lead to abnormal proliferation. Particularly, we show that $\mathit{Cry1}$, $\mathit{Cry2}$ mutations decrease the growth rate of cells, $\mathit{Per2}$ mutation enhances it and $\mathit{Bmal1}$ knockout increases it for autonomous periods of the cell cycle less than 21 h and decreases it elsewhere. Combining a molecular model to a population model offers new insight on the influence of the circadian clock on the growth of a cell population. This can help chronotherapy which takes benefits of physiological rhythms to improve anti-cancer efficacy and tolerance to drugs by administering treatments at a specific time of the day

Une nouvelle approche pour la gestion de flux temps réels basée sur l'algorithme EDF

Pour répondre aux exigences temporelles de flux temps réels, beaucoup de techniques d'ordonnancement de paquets ont été proposées dans la littérature, pour être utilisées au niveau de routeurs IP. La technique utilisant l'algorithme EDF a attiré une attention particulière, car l'optimalité de cet algorithme a été prouvée pour un nombre important de critères. Cependant la complexité et le surcoût induits par l'algorithme EDF ont constitué toujours un handicap majeur empêchant son implémentation. Dans ce papier, nous proposons une nouvelle approche d'ordonnancement, dite hybride, qui permet de combiner la puissance de EDF et la simplicité de l'algorithme standard FIFO. l'approche proposée a une complexité beaucoup plus réduite que celle de EDF. Les résultats de simulation soulignent l'efficacité de cette approche hybride

Structure-property relationships for polycarboxylate ether superplasticizers by means of RAFT polymerization

Hypothesis: Polycarboxylate ether (PCE) comb-copolymers are widely used as water reducing agents in the concrete industry while maintaining a high fluidity via the polymer adsorption to the cement particles. PCE copolymers with a broad range of structures are well established by Free radical polymerization, however, understanding the structure-property relationship is still complex due to the high polydispersity of PCE copolymers prepared by conventional polymerization. The influence of different structural parameters using well-defined polymeric structures is yet to be explored. Experiments: In this study, two different types of comb-like random copolymers, namely polycarboxylate ether (PCE; poly(oligo(ethylene glycol) methyl ether methacrylate/methacrylic acid)) and polysulfonate ether (PSE; poly(oligo(ethylene glycol) methyl ether acrylate/sodium 4-styrenesulfonate)), were synthesized by RAFT polymerization to enable the synthesis of polymers with controlled features. The effect of charge types and side chain lengths on the adsorption, rheology, and dispersing ability of cement pastes have been studied. Findings: RAFT polymerization could be used to prepare PCE random copolymers with good control over the polymer molecular weight and narrow polydispersity (D < 1.3). Results revealed that the zeta-potential values depend on both the charge type and side chain lengths. Copolymers containing SO3- exhibited higher absolute negative zeta-potential values than COO- while PCE copolymers with shorter side chains developed higher absolute negative zeta-potential values. On the other hand, the adsorption study demonstrated that decreasing the side chain lengths lead to higher adsorption of PCE copolymers while Copolymers with COO- groups were found to be adsorbed more than SO3- counterparts. These results are further confirmed with the rheological studies and it is found that the shorter the side chain, the lower the yield stress and the higher the dispersion of cement pastes but to a limited effect. Additionally, the charge types have a major influence on the performance of superplasticizers. This study could make further progress in establishing superplasticizers with controlled architectures for better performance

Structural build-up of cementitious paste with nano-Fe3O4 under time-varying magnetic fields

The structural build-up of cementitious paste with nano-Fe3O4 under time-varying magnetic fields was experimentally investigated using small amplitude oscillatory shear (SAOS) technique. Several modes of magnetic fields, such as constant, sudden-changed and linearly-changed, were applied to the cementitious paste. Results showed that the structural build-up of the cementitious paste depended on the magnetizing time and magnetic field strength. Applying constant magnetic fields improved the liquid-like behavior during first minutes and afterwards the solid-like property was enhanced. Both the sudden-increased and sudden-decreased magnetic fields resulted in a sharp decrease in storage modulus. The linearly increasing magnetic field resulted in a slight increase in storage modulus but higher liquid-like behavior. When the magnetic field was linearly decreased from 0.5 T to approx. 0.25 T, the structural build-up was enhanced significantly, and with the continuously decreasing magnetic field from approx. 0.25 T to 0 T, a decrease in storage modulus was observed

Vector competence of Aedes vexans (Meigen), Culex poicilipes (Theobald) and Cx. quinquefasciatus Say from Senegal for West and East African lineages of Rift Valley fever virus

Background Rift Valley fever virus (RVFV; Phlebovirus, Bunyaviridae) is a mosquito–borne, zoonotic pathogen. In Senegal, RVFV was first isolated in 1974 from Aedes dalzieli (Theobald) and thereafter from Ae. fowleri (de Charmoy), Ae. ochraceus Theobald, Ae. vexans (Meigen), Culex poicilipes (Theobald), Mansonia africana (Theobald) and Ma. uniformis (Theobald). However, the vector competence of these local species has never been demonstrated making hypothetical the transmission cycle proposed for West Africa based on serological data and mosquito isolates. Methods Aedes vexans and Cx. poicilipes, two common mosquito species most frequently associated with RVFV in Senegal, and Cx. quinquefasciatus, the most common domestic species, were assessed after oral feeding with three RVFV strains of the West and East/central African lineages. Fully engorged mosquitoes (420 Ae. vexans, 563 Cx. quinquefasciatus and 380 Cx. poicilipes) were maintained at 27 ± 1 °C and 70–80 % relative humidity. The saliva, legs/wings and bodies were tested individually for the RVFV genome using real-time RT-PCR at 5, 10, 15 and 20 days post exposure (dpe) to estimate the infection, dissemination, and transmission rates. Genotypic characterisation of the 3 strains used were performed to identify factors underlying the different patterns of transmission. Results The infection rates varied between 30.0–85.0 % for Ae. vexans, 3.3–27 % for Cx. quinquefasciatus and 8.3–46.7 % for Cx. poicilipes, and the dissemination rates varied between 10.5–37 % for Ae. vexans, 9.5–28.6 % for Cx. quinquefasciatus and 3.0–40.9 % for Cx. poicilipes. However only the East African lineage was transmitted, with transmission rates varying between 13.3–33.3 % in Ae. vexans, 50 % in Cx. quinquefasciatus and 11.1 % in Cx. poicilipes. Culex mosquitoes were less susceptible to infection than Ae. vexans. Compared to other strains, amino acid variation in the NSs M segment proteins of the East African RVFV lineage human-derived strain SH172805, might explain the differences in transmission potential. Conclusion Our findings revealed that all the species tested were competent for RVFV with a significant more important role of Ae. vexans compared to Culex species and a highest potential of the East African lineage to be transmitted

CFD implementation of time-dependent behaviour : application for concrete pumping

Sorptivity describes the pore connectivity of cementitious materials. This property is widely used for the assessment of the resistance of concrete to the ingress of aggressive agents. However, anomalous behaviour of cementitious materials during water uptake is usually reported. This is possibly explained by the effect of the hygroscopic nature of cementitious materials on the dynamics of the process. Water affinity of C-S-H might turn it into an imbibant and cause swelling as the material is exposed to water. Development of swelling can cause a variable hydraulic diffusivity of the material with time, and this is consistent with the deviation from the progress of the water uptake with the square root of time in the short term usually reported in the literature for the particular case of cementitious materials. This paper provides experimental results in support of the occurrence of swelling during water uptake in mortar samples. Consequently, the term capillary imbibition instead of capillary absorption seems more appropriate for describing the water uptake by capillarity of cementitious materials, as imbibition is usually connected to swelling. The idea of cementitious materials as rigid materials during water uptake seems incomplete for a complete description of the process