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We present a comprehensive non-perturbative study of the phase structure ofthe asymptotically safe Standard Model. The physics scales included range fromthe asymptotically safe trans-Planckian regime in the ultraviolet, theintermediate high-energy regime with electroweak symmetry breaking to stronglycorrelated QCD in the infrared. All flows are computed with a self-consistentfunctional renormalisation group approach, using a vertex expansion in thefluctuation fields. In particular, this approach takes care of all physicalthreshold effects and the respective decoupling of ultraviolet degrees offreedom. Standard Model and gravity couplings and masses are fixed by theirexperimental low energy values. Importantly, we accommodate for the differencebetween the top pole mass and its Euclidean analogue. Both, the correct massdetermination and the threshold effects have a significant impact on thequalitative properties, and in particular on the stability properties of thespecific ultraviolet-infrared trajectory with experimental Standard Modelphysics in the infrared. We show that in the present rather advancedapproximation the matter part of the asymptotically safe Standard Model has thesame number of relevant parameters as the Standard Model, and is asymptoticallyfree. This result is based on the novel UV fixed point found in the presentwork: the fixed point Higgs potential is flat but has two relevant directions.These results and their analysis are accompanied by a thorough discussion ofthe systematic error of the present truncation, also important for systematicimprovements.

Bioindication has become an indispensable part of water quality monitoring in most countries of the world, with the presence and abundance of bioindicator taxa, mostly multicellular eukaryotes, used for biotic indices. In contrast, microbes (bacteria, archaea and protists) are seldom used as bioindicators in routine assessments, although they have been recognized for their importance in environmental processes. Recently, the use of molecular methods has revealed unexpected diversity within known functional groups and novel metabolic pathways that are particularly important in energy and nutrient cycling. In various habitats, microbial communities respond to eutrophication, metals, and natural or anthropogenic organic pollutants through changes in diversity and function. In this review, we evaluated the common trends in these changes, documenting that they have value as bioindicators and can be used not only for monitoring but also for improving our understanding of the major processes in lotic and lentic environments. Current knowledge provides a solid foundation for exploiting microbial taxa, community structures and diversity, as well as functional genes, in novel monitoring programs. These microbial community measures can also be combined into biotic indices, improving the resolution of individual bioindicators. Here, we assess particular molecular approaches complemented by advanced bioinformatic analysis, as these are the most promising with respect to detailed bioindication value. We conclude that microbial community dynamics are a missing link important for our understanding of rapid changes in the structure and function of aquatic ecosystems, and should be addressed in the future environmental monitoring of freshwater ecosystems.

Scientific studies have demonstrated the usefulness of benthic foraminifera as bioindicators to assess the health of marine, coastal, and transitional ecosystems. Similar to macrofauna, these organisms are reliable proxies for biomonitoring. Despite recent scientific advances, Brazilian official monitoring plans using biotic indices on coastal and ocean environments with soft sediment areas remain mostly restricted to a few types of organisms. Therefore, to include benthic foraminifera in Brazilian biomonitoring routines regulated by national environmental guidelines and standards, the paper presents the challenges, which must be overcome, some recommendations and steps to move forward to implement foraminifera as bioindicators in biomonitoring routines. In light of it, it is essential to consider the contribution of the Brazilian foraminiferal research in this implementation process, improving ecological quality indices, adapting methods, and applying genetics tools. This paper is a step in this direction, which aims to strengthen the role of benthic foraminifera as a reliable tool in Brazilian biomonitoring.

National audience; Dans les écosystèmes lacustres, les sédiments et les organismes benthiques jouent un rôle important dans les cycles biogéochimiques et contribuent aux réseaux trophiques. L'évaluation des risques et des effets écotoxicologiques sur les organismes du sédiment repose essentiellement sur l'utilisation de populations modèles (tests de toxicité au laboratoire ou encagement in situ). Compléter ces approches par l'étude des réponses aux contaminants à l'échelle de communautés naturelles permettrait de renforcer la dimension écologique de l'évaluation des risques en considérant les effets sur les diversités phylogénétique et fonctionnelle. Cela ouvrirait de nombreuses perspectives pour mieux évaluer l'impact des contaminants sur les communautés benthiques et leurs conséquences sur le fonctionnement des écosystèmes lacustres. Afin d'évaluer in situ les impacts écotoxicologiques à l'échelle des communautés, une étude collaborative internationale combinant des approches complémentaires d'écologie, d'écotoxicologie et de chimie a été menée sur le lac Léman. La variabilité spatio-temporelle des communautés de sédiment de surface a été étudiée pour huit stations d'échantillonnage réparties sur le lac et exposées à une large gamme de contamination par des métaux et des composés organiques. Les caractéristiques structurelles et fonctionnelles des communautés bactériennes étudiées sont relativement stables dans le temps au sein de chaque site mais diffèrent selon les sites considérés. Pour les communautés bactériennes hétérotrophes, une acquisition de tolérance au cuivre a été mise en évidence suivant le concept du PICT (pollution-induced community tolerance) pour les sites présentant les plus fortes concentrations de cuivre. Pour les communautés d'invertébrés, la distribution relative des espèces sensibles et tolérantes était corrélée aux niveaux de contamination. Ces résultats mettent en évidence la pertinence d'étudier les effets de contaminants à l'échelle des communautés et la complémentarité des différentes mesures de structure et de fonctions déployées pour évaluer la qualité des sédiments dans les lacs et plus généralement pour les sédiments des écosystèmes aquatiques continentaux.

Large discoidal soritid foraminiferans (Soritinae) are abundant in coral reef ecosystems. As with the many cnidarian invertebrates that inhabit these systems, they also depend on symbiotic dinoflagellates (Symbiodinium) for their growth and survival. Several particular Symbiodinium sub-genera or clades inhabit these soritids. One of these groups, referred to as cladeC, dominates corals and their relatives throughout the tropical Indo-Pacific. In contrast, the distributions of Symbiodinium spp. from cladesA, B, and C are more evenly apportioned across Caribbean invertebrate communities. To explore the possibility that a similar biogeographic break exists in the symbionts harbored by soritids, we surveyed the Symbiodinium spp. from the soritid genus Sorites, collected from the Pacific and Caribbean coasts of Panama as well as from Florida. Characterization of Symbiodinium obtained from foraminiferal and cnidarian samples was conducted using restriction fragment length polymorphism and phylogenetic analyses of the nuclear internal transcribed spacer region2 (ITS2) and a portion of the large subunit ribosomal DNA sequences. A distinctive biogeographic break between the kinds of symbionts found in Sorites from the East Pacific and Caribbean was clearly evident. Differences between cnidarian and foraminferan symbioses in each ocean may be explained by the subjection of Caribbean communities to severer environmental conditions during the early Quarternary. Caribbean Sorites spp. harbored symbionts described from cladeF (specifically sub-cladeFr4) and cladeH (formally referred to as Fr1), while Sorites spp. from the eastern Pacific were dominated by a single Symbiodinium haplotype in cladeC. An ITS2 phylogeny determined that most cladeC "types” recovered from Indo-Pacific soritids form a monophyletic sub-lineage with other cladeC symbionts typically found in Pacific corals from the genus Porites. The existence of multiple Symbiodinium lineages at various taxonomic levels associated specifically with soritids indicates that symbioses with these hosts are important in driving Symbiodinium spp. evolution

International audience; Sediments play a crucial role in biogeochemical cycles and food-webs in lakes. Studying impacts of contaminants on sediment-associated communities would allow to take into consideration specific and functional biodiversity in effect-based studies and monitoring programs, thus opening prospects to evaluate resulting effects on benthic ecological functioning. However, the lack of adequate strategies and methods in sediment-ecotoxicology limits the in situ evaluation of such impacts. To pave the way for implementing relevant sediment ecotoxicological approaches at community level, we initiated a collaborative study combining concepts of ecology, ecotoxicology and chemistry. We examined the spatiotemporal variations in benthic communities collected in surface sediments from eight sampling stations in Lake Geneva, which covered a large range of contamination levels by metals and organic compounds. Structural and functional characteristics of the bacterial communities varied according to the sampling dates and location. Based on the pollution-induced community tolerance (PICT) concept, bacterial tolerance and resistance potential to copper were positively correlated to copper concentrations in sediments. Relative distribution of sensitive/tolerant species in invertebrate communities was also related to the contamination conditions. Overall, our results evidenced the relevance of using benthic communities for the evaluation of sediment quality in lakes, and fresh waters in general.

Heavy metals such as mercury (Hg) occur in ecosystems from both natural sources and human activities, with large variations in concentrations and pose a significant health hazard through bioaccumulation and biomagnification. The aim of this experimental study is to assess the impact of different concentrations of Hg through time on the diversity of cultured benthic foraminifera. Tanks with concentrations of Hg up to 100 ppm were considered. Mesocosms containing 1-cm-thick sediment from each tank were subsampled at pre-established time intervals for geochemical (Hg content), morphological and molecular analyses. Morphological analyses were based on both Rose Bengal and the CellTracker Green (CTG) techniques. Molecular analyses comprised high-throughput sequencing (HTS) of foraminiferal DNA. A total of 6 datasets were generated: two from Rose Bengal morphological analysis (fraction> 63 μm and fraction >125 μm), one from CTG morphological analysis (fraction>125 μm), three from HTS run (one for each considered filter: Filter1, Filter10, Filter100). Species richness, Shannon and Fisher α alpha indices were all negatively correlated with the Hg concentrations both in water and sediment regardless the considered datasets. Since the strongest correlations were observed among diversity indices and normalized fourth-root transformed HTS data (Filter1), the multivariate analyses (nMDS and Cluster Analysis) were based on this dataset only. The nMDS highlights the negative effect of Hg pollution on the benthic foraminiferal assemblages at the highest concentrations, namely 10 ppm after three weeks and 100 ppm after two weeks of treatment. This experiment demonstrates the huge potential of metabarcoding for unraveling the impact of pollution on benthic foraminiferal assemblages.