A RBA model for the chemostat modeling

A RBA model for the chemostat modeling. 58. Conference on Decision and Contro

Consistency and convergence rate of phylogenetic inference via regularization

It is common in phylogenetics to have some, perhaps partial, information about the overall evolutionary tree of a group of organisms and wish to find an evolutionary tree of a specific gene for those organisms. There may not be enough information in the gene sequences alone to accurately reconstruct the correct "gene tree." Although the gene tree may deviate from the "species tree" due to a variety of genetic processes, in the absence of evidence to the contrary it is parsimonious to assume that they agree. A common statistical approach in these situations is to develop a likelihood penalty to incorporate such additional information. Recent studies using simulation and empirical data suggest that a likelihood penalty quantifying concordance with a species tree can significantly improve the accuracy of gene tree reconstruction compared to using sequence data alone. However, the consistency of such an approach has not yet been established, nor have convergence rates been bounded. Because phylogenetics is a non-standard inference problem, the standard theory does not apply. In this paper, we propose a penalized maximum likelihood estimator for gene tree reconstruction, where the penalty is the square of the Billera-Holmes-Vogtmann geodesic distance from the gene tree to the species tree. We prove that this method is consistent, and derive its convergence rate for estimating the discrete gene tree structure and continuous edge lengths (representing the amount of evolution that has occurred on that branch) simultaneously. We find that the regularized estimator is "adaptive fast converging," meaning that it can reconstruct all edges of length greater than any given threshold from gene sequences of polynomial length. Our method does not require the species tree to be known exactly; in fact, our asymptotic theory holds for any such guide tree.Comment: 34 pages, 5 figures. To appear on The Annals of Statistic

On the convergence of the maximum likelihood estimator for the transition rate under a 2-state symmetric model

Maximum likelihood estimators are used extensively to estimate unknown parameters of stochastic trait evolution models on phylogenetic trees. Although the MLE has been proven to converge to the true value in the independent-sample case, we cannot appeal to this result because trait values of different species are correlated due to shared evolutionary history. In this paper, we consider a $2$-state symmetric model for a single binary trait and investigate the theoretical properties of the MLE for the transition rate in the large-tree limit. Here, the large-tree limit is a theoretical scenario where the number of taxa increases to infinity and we can observe the trait values for all species. Specifically, we prove that the MLE converges to the true value under some regularity conditions. These conditions ensure that the tree shape is not too irregular, and holds for many practical scenarios such as trees with bounded edges, trees generated from the Yule (pure birth) process, and trees generated from the coalescent point process. Our result also provides an upper bound for the distance between the MLE and the true value

Une méthode d'identification de la rhéologie du métal et du lubrifiant lors du tréfilage

National audienceNous montrons comment l'analyse thermomécanique élémentaire d'une passe de tréfilage et la mesure de la force et d'une température de filière pour divers lubrifiants permettent d'identifier le travail de déformation plastique lié à la réduction du fil, ainsi que les cissions de frottement relatives aux lubrifiants utilisés. Nous présentons le protocole expérimental et discutons la relation entre la formulation des lubrifiants et le frottement estimé

Non-thermal plasma abatement of trichloroethylene with DC corona discharges

The decomposition of trichloroethylene (TCE) in air by non-thermal plasma was investigated with a multi-pin-to-plate direct current (DC) discharge at atmospheric pressure and room temperature. The effects of various operating parameters on the removal efficiency (RE) were examined. The experiments indicated that for low energy densities higher removal could be obtained with positive corona. For negative corona and 10 % relative humidity (RH) a maximum RE of 99.5 % could be achieved at 1100 J L-1. Formation of by-products was qualitatively analyzed in detail with FT-IR spectroscopy and mass spectrometry. Detected by-products for negative corona operated at 300 J L-1 and 10 % RH include dichloroacetylchloride, trichloroacetaldehyde, phosgene, ozone, HCl, Cl2, CO and CO2. The highest RE for TCE was achieved with a relative humidity of 19 %

Knockdown resistance in Anopheles vagus, An. sinensis, An. paraliae and An. peditaeniatus populations of the Mekong region

BACKGROUND: In the Mekong region (Vietnam, Cambodia and Laos), a large investigation was conducted to assess the susceptibility of Anopheles species against DDT and pyrethroids. In this study, the resistance status of the potential malaria vectors An. vagus, An. sinensis, An. paraliae and An. peditaeniatus was assessed. METHODS: Bioassays were performed on field collected unfed female mosquitoes using the standard WHO susceptibility tests. In addition, the DIIS6 region of the para-type sodium channel gene was amplified and sequenced and four allele-specific PCR assays were developed to assess the kdr frequencies. RESULTS: In Southern Vietnam all species were DDT and pyrethroid resistant, which might suggest the presence of a kdr resistance mechanism. Sequence-analysis of the DIIS6 region of the para-type sodium channel gene revealed the presence of a L1014S kdr mutation in An. vagus, An. sinensis and An. paraliae. In An. peditaeniatus, a low frequency L1014S kdr mutation was found in combination with a high frequency L1014F kdr mutation. For pyrethroids and DDT, no genotypic differentiation was found between survivors and non-survivors for any of these species. In the two widespread species, An. vagus and An. sinensis, kdr was found only in southern Vietnam and in Cambodia near the Vietnamese border. CONCLUSIONS: Different levels of resistance were measured in Laos, Cambodia and Vietnam. The kdr mutation in different Anopheles species seems to occur in the same geographical area. These species breed in open agricultural lands where malaria endemicity is low or absent and vector control programs less intensive. It is therefore likely that the selection pressure occurred on the larval stages by insecticides used for agricultural purpose

Distribution of Anopheles in Vietnam, with particular attention to malaria vectors of the Anopheles minimus complex

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Dynamics of agriculture – rural of one commune in Red River Delta in period of economic transition from 1980 to present: case of Cam Hoang commune, Cam Giang, Hai Duong

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