Search results for " Populations"
showing 10 items of 173 documents
Time evolution of non-lethal infectious diseases: a semi-continuous approach.
2005
A model describing the dynamics related to the spreading of non-lethal infectious diseases in a fixed-size population is proposed. The model consists of a non-linear delay-differential equation describing the time evolution of the increment in the number of infectious individuals and depends upon a limited number of parameters. Predictions are in good qualitative agreement with data on influenza.
Identification of Replicator Mutator models
2006
The complexity of biology literally calls for quantitative tools in order to support and validate biologists intuition and traditional qualitative descriptions. In this paper, the Replicator-Mutator models for Evolutionary Dynamics are validated/invalidated in a worst-case deterministic setting. These models analyze the DNA and RNA evolution or describe the population dynamics of viruses and bacteria. We identify the Fitness and the Replication Probability parameters of a genetic sequences, subject to a set of stringent constraints to have physical meaning and to guarantee positiveness. The conditional central estimate is determined in order to validate/invalidate the model. The effectivene…
Transcriptional Rewiring, Adaptation, and the Role of Gene Duplication in the Metabolism of Ethanol of Saccharomyces cerevisiae
2020
Ethanol is the main by-product of yeast sugar fermentation that affects microbial growth parameters, being considered a dual molecule, a nutrient and a stressor. Previous works demonstrated that the budding yeast arose after an ancient hybridization process resulted in a tier of duplicated genes within its genome, many of them with implications in this ethanol “produce-accumulate-consume” strategy. The evolutionary link between ethanol production, consumption, and tolerance versus ploidy and stability of the hybrids is an ongoing debatable issue. The implication of ancestral duplicates in this metabolic rewiring, and how these duplicates differ transcriptionally, remains unsolved. Here, we …
Aborted quantitative study in the French music industry: the changes of music labels facing streaming
2020
International audience; This paper shows a failed case study of the impact of streaming on labels’ life through the exploitation of three quantitative databases. Streaming is a major external change for the music consumption and music producers. As labels are dealing with both producers and consumers, they may have been hardly impacted by this change. Yet there was a need to identify the changes that streaming brought and its impact for the organizations that decided not to adopt it. The ecology of population framework and the death vs dynamism dyad was supposed to give a clear reading of this phenomenon. In order to identify labels that did not adopt streaming, three databases were tested,…
Estimer des flux de navetteurs avec un modèle gravitaire
2019
Dans ce poster, nous présentons le modèle gravitaire sous différents modèles en mettant en évidence les effets de distance et les occasions interposées. Le modèle généralisé de Newton est utilisé et donne des estimations relativement correctes des flux intercommunaux en région PACA.
Hybridization, developmental stability, and functionality of morphological traits in the ground beetle Carabus solieri (Coleoptera, Carabidae).
2006
Correspondance.: stephane.garnier@u-bourgogne.fr; International audience; The assessment of developmental stability in hybrids can provide valuable information in the study of species formation because it allows an evaluation of the degree of incompatibility of genetic systems that control developmental processes. The present study assessed the impact of two hybridization events, assumed to have occurred at different times, on developmental instability in the ground beetle Carabus solieri . Developmental instability was estimated in 678 individuals from 27 populations from the fluctuating asymmetry (FA) levels of four morphological traits: the tibia length of middle and hind legs, which are…
Recurrent domestication by Lepidoptera of genes from their parasites mediated by Bracoviruses
2015
Bracoviruses are symbiotic viruses associated with tens of thousands of species of parasitic wasps that develop within the body of lepidopteran hosts and that collectively parasitize caterpillars of virtually every lepidopteran species. Viral particles are produced in the wasp ovaries and injected into host larvae with the wasp eggs. Once in the host body, the viral DNA circles enclosed in the particles integrate into lepidopteran host cell DNA. Here we show that bracovirus DNA sequences have been inserted repeatedly into lepidopteran genomes, indicating this viral DNA can also enter germline cells. The original mode of Horizontal Gene Transfer (HGT) unveiled here is based on the integrativ…
A Combined Multi-Cohort Approach Reveals Novel and Known Genome-Wide Selection Signatures for Wool Traits in Merino and Merino-Derived Sheep Breeds.
2019
Merino sheep represents a valuable genetic resource worldwide. In this study, we investigated selection signatures in Merino (and Merino-derived) sheep breeds using genome-wide SNP data and two different approaches: a classical F-ST-outlier method and an approach based on the analysis of local ancestry in admixed populations. In order to capture the most reliable signals, we adopted a combined, multi-cohort approach. In particular, scenarios involving four Merino breeds (Spanish Merino, Australian Merino, Chinese Merino, and Sopravissana) were tested via the local ancestry approach, while nine pair-wise breed comparisons contrasting the above breeds, as well as the Gentile di Puglia breed, …
Learning to read with Graphogame, an ethnography in a Peruvian rural school
2015
The purpose of the present ethnographic case study is to examine what happens when the literacy learning software Graphogame, designed in Finland, is introduced in a new and radically different context, that of a poor rural school in the Peruvian Andes. The research attempts to complement the quantitative approach which has dominated the research on Graphogame. It also aims to take into consideration the unique circumstances and challenges of rural Peru and how they can affect the use and implementation of the software. I spent two months in the rural school of Quilcas, where nine struggling readers used Graphogame for daily 20 minutes remedial sessions. In this research setting, I conducte…
Data from: Temporal relationship between genetic and warning signal variation in the aposematic wood tiger moth (Parasemia plantaginis)
2014
Many plants and animals advertise unpalatability through warning signals in the form of colour and shape. Variation in warning signals within local populations is not expected because they are subject to directional selection. However, mounting evidence of warning signal variation within local populations suggests that other selective forces may be acting. Moreover, different selective pressures may act on the individual components of a warning signal. At present, we have a limited understanding about how multiple selection processes operate simultaneously on warning signal components, and even less about their temporal and spatial dynamics. Here, we examined temporal variation of several w…