Search results for "Actor"
showing 10 items of 19159 documents
Field evidence of host size-dependent parasitism in two manipulative parasites.
2007
5 pages; International audience; The distribution of parasites within host natural populations has often been found to be host age-dependent. Host mortality induced by parasites is the commonest hypothesis proposed for explaining this pattern. Despite its potential importance in ecology, the parasitism intensity in relation with the host age has rarely been studied in the field. The 2 manipulative acanthocephalans, Polymorphus minutus and Pomphorhynchus laevis, use the amphipod Gammarus pulex as an intermediate host, and their infection intensity and incidence among G. pulex populations were examined by analyzing 2 large samples of hosts collected in eastern France. Both parasites had low p…
The challenge of habitat modelling for threatened low density species using heterogeneous data: The case of Cuvier’s beaked whales in the Mediterrane…
2018
We are grateful to the ACCOBAMS Secretariat for their support in this work, including a small grant for the analysis. The Mediterranean population of Cuvieŕs beaked whale (Ziphius cavirostris), a deep-diving cetacean, is genetically distinct from the Atlantic, and subject to a number of conservation threats, in particular underwater noise. It is also cryptic at the surface and relatively rare, so obtain robust knowledge on distribution and abundance presents unique challenges. Here we use multiplatform and multiyear survey data to analyse the distribution and abundance of this species across the Mediterranean Sea. We use a novel approach combining heterogeneous data gathered with different …
Environmental factors influencing the spatio-temporal distribution of Carybdea marsupialis (Lineo, 1978, Cubozoa) in South-Western Mediterranean coas…
2017
21 pages, 5 figures, 2 tables, supporting information 10.1371/journal.pone.0181611.s001, 10.1371/journal.pone.0181611.s002, 10.1371/journal.pone.0181611.s003, 10.1371/journal.pone.0181611.s004, 10.1371/journal.pone.0181611.s005, 10.1371/journal.pone.0181611.s006
Integrated Fixed Film Activated Sludge (IFAS) membrane BioReactor: The influence of the operational parameters
2020
Abstract The present paper investigated an Integrated Fixed Film Activated Sludge (IFAS) Membrane BioReactor (MBR) system monitored for 340 days. In particular, the short-term effects of some operational parameters variation was evaluated. Results showed a decrease of the removal rates under low C/N values. Respirometry results highlighted that activated sludge was more active in the organic carbon removal. Conversely, biofilm has a key role during nitrification. The major fouling mechanism was represented by the cake deposition (irreversible).
Functional and Pharmacological Analyses of the Role of Penicillium digitatum Proteases on Virulence
2019
© The Author(s).
Increasing temperature alters the within-host competition of viral strains and influences virus genetic variability
2021
Environmental conditions can affect viral accumulation, virulence and adaptation, which have implications in the disease outcomes and efficiency of control measures. Concurrently, mixed viral infections are relevant in plants, being their epidemiology shaped by within-host virus–virus interactions. However, the extent in which the combined effect of variations in abiotic components of the plant ecological niche and the prevalence of mixed infections affect the evolutionary dynamics of viral populations is not well understood. Here, we explore the interplay between ecological and evolutionary factors during viral infections and show that isolates of two strains of Pepino mosaic potexvirus co…
Natural Selection Fails to Optimize Mutation Rates for Long-Term Adaptation on Rugged Fitness Landscapes
2008
The rate of mutation is central to evolution. Mutations are required for adaptation, yet most mutations with phenotypic effects are deleterious. As a consequence, the mutation rate that maximizes adaptation will be some intermediate value. Here, we used digital organisms to investigate the ability of natural selection to adjust and optimize mutation rates. We assessed the optimal mutation rate by empirically determining what mutation rate produced the highest rate of adaptation. Then, we allowed mutation rates to evolve, and we evaluated the proximity to the optimum. Although we chose conditions favorable for mutation rate optimization, the evolved rates were invariably far below the optimu…
Integrated membrane bioreactors modelling: A review on new comprehensive modelling framework
2021
International audience; Integrated Membrane Bioreactor (MBR) models, combination of biological and physical models, have been representing powerful tools for the accomplishment of high environmental sustainability. This paper, produced by the International Water Association (IWA) Task Group on Membrane Modelling and Control, reviews the state-of-the-art, identifying gaps for future researches, and proposes a new integrated MBR modelling framework. In particular, the framework aims to guide researchers and managers in pursuing good performances of MBRs in terms of effluent quality, operating costs (such as membrane fouling, energy consumption due to aeration) and mitigation of greenhouse gas…
Interspecific variation in total phenolic content in temperate brown algae
2017
Marine algae synthesize secondary metabolites such as polyphenols that function as defense and protection mechanisms. Among brown algae, Fucales and Dictyotales (Phaeophyceae) contain the highest levels of phenolic compounds, mainly phlorotannins, that play multiple roles. Four temperate brown algae (Cystoseira amentacea, Cystoseira compressa, Dictyopteris polypodioides and Padina pavonica) were studied for total phenolic contents. Total phenolic content was determined colorimetrically with the Folin-Ciocalteu reagent. Significant differences in total phenolic content were observed between leathery and sheetlike algae and also within each morphological group. Among the four species, the she…
An STE12 gene identified in the mycorrhizal fungus Glomus intraradices restores infectivity of a hemibiotrophic plant pathogen
2009
International audience; * • Mechanisms of root penetration by arbuscular mycorrhizal (AM) fungi are unknown and investigations are hampered by the lack of transformation systems for these unculturable obligate biotrophs. Early steps of host infection by hemibiotrophic fungal phytopathogens, sharing common features with those of AM fungal colonization, depend on the transcription factor STE12. * • Using degenerated primers and rapid amplification of cDNA ends, we isolated the full-length cDNA of an STE12-like gene, GintSTE, from Glomus intraradices and profiled GintSTE expression by real-time and in situ RT-PCR. GintSTE activity and function were investigated by heterologous complementation …