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176 result(s) for "Bourmaud, A."
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Naturally occurring fire coral clones demonstrate a genetic and environmental basis of microbiome composition
Coral microbiomes are critical to holobiont functioning, but much remains to be understood about how prevailing environment and host genotype affect microbial communities in ecosystems. Resembling human identical twin studies, we examined bacterial community differences of naturally occurring fire coral clones within and between contrasting reef habitats to assess the relative contribution of host genotype and environment to microbiome structure. Bacterial community composition of coral clones differed between reef habitats, highlighting the contribution of the environment. Similarly, but to a lesser extent, microbiomes varied across different genotypes in identical habitats, denoting the influence of host genotype. Predictions of genomic function based on taxonomic profiles suggest that environmentally determined taxa supported a functional restructuring of the microbial metabolic network. In contrast, bacteria determined by host genotype seemed to be functionally redundant. Our study suggests microbiome flexibility as a mechanism of environmental adaptation with association of different bacterial taxa partially dependent on host genotype. The microbiomes associated with reef corals are complex and diverse. Here, the authors investigate fire coral clones naturally occurring in distinct habitats as a model system to disentangle the contribution of host genotype and environment on their microbiome, and predict genomic functions based on taxonomic profiles.
Cryptic diversity, low connectivity and suspected human-mediated dispersal among 17 widespread Indo-Pacific hydroid species of the south-western Indian Ocean
Aim: To investigate whether the populations of 17 widespread hydroid species are connected on a demographic level (one to few generations) or are mostly connected on evolutionary timescales. Location: Coral reefs of the South-western Indian Ocean. Taxon: 17 widespread hydroid species (Cnidaria, Hydrozoa). Methods: Using mitochondrial (16S) and nuclear (Calmodulin) sequences, we analysed 17 co-distributed hydroid species with contrasting life history traits (with or without a pelagic life history phase). We used DNA-based species delimitation methods, haplotype networks, analysis of molecular variance, and Bayesian skyline plots to investigate diversification and connectivity patterns in the region. Results: Putative cryptic species were revealed in half of the species and the 17 species resulted in 54 cryptic lineages. The high isolation of hydroid populations in the region is underlined by the rarity of shared haplotypes among localities in most of the species studied. In contrast, haplotypes shared between specimens collected in different ocean basins were found in three species and suggest recent introductions via human activities. The presence of a short pelagic dispersal phase did not seem to increase the connectivity levels of the studied populations, as no significant differences in genetic structure were detected between species with contrasting life history traits. Main conclusions: These results highlight once again our incomplete knowledge of the marine invertebrate fauna, as we might be underestimating hydroid diversity by two-thirds, and are discussed in terms of diversification processes, dynamics of the Indo-Pacific biodiversity and the role of its peripheral marine provinces.
Cryptic Diversity and Genetic Differentiation of Mesophotic Hydroids in the Southwestern Indian Ocean
The western Indian Ocean (WIO) is recognized as a marine biodiversity hotspot with complex oceanographic circulation resulting in limited connectivity between remote islands. This ocean region comprises several subregions of varying biodiversity, with the northern Mozambique Channel standing out as the core of this hotspot. Although the hydroids in this region are known to include cryptic species and show contrasting connectivity patterns, the mesophotic depths remain largely unexplored. The Deep Reef Refuge Hypothesis suggests that mesophotic coral ecosystems may act as refuges. However, this hypothesis is based on several prerequisites that could be affected by the presence of cryptic species. We investigated the genetic diversity and connectivity of seven hydroid species by collecting samples at euphotic and mesophotic depths around the islands of Mayotte and Reunion. Population genetic patterns were investigated using multivariate analyses and Bayesian clustering, with 8–18 microsatellite markers per species. The results revealed greater genetic diversity in Mayotte than in Reunion, even though fewer samples were collected there. This is in line with the location of the heart of the hotspot in the northern part of the WIO. In addition, all species exhibited strong genetic differentiation between samples from the two islands, supporting the “one island, one species” hypothesis previously proposed for hydroids in the region. However, contrasting values were obtained among depths depending on the species and the island, demonstrating the importance of a multi‐species approach. The inclusion of mesophotic samples from the Taxella eximia/gracilicaulis and Macrorhynchia phoenicea species complexes provides new insights into the true biodiversity of these genera, revealing additional cryptic species and putative hybridization. Furthermore, the genetic connectivity estimation performed here among depths highlights several species that could be evaluated in terms of the vertical connectivity prerequisite of the Deep Reef Refuge Hypothesis in Mayotte and Reunion. To assess whether hydroids (Cnidaria, Hydrozoa) are good candidates to test the Deep Reef Refuge Hypothesis and particularly the vertical connectivity component, we analysed the genetic diversity and structure of seven species sampled across euphotic and mesophotic depths around Mayotte and Reunion in the southwestern Indian Ocean. Consistent with the position of the western Indian Ocean's biodiversity hotspot, genetic diversity was higher in Mayotte than in Reunion, while all species showed strong genetic differentiation between islands. Incorporating mesophotic samples not only uncovered additional cryptic lineages, but also revealed depth‐related genetic patterns that varied sharply among species and between islands.
Medusae (Cnidaria) of Reunion Island (South West Indian Ocean): Diversity, Abundance and Distribution
Numerous studies have been conducted on the benthic stages of Medusozoa in Reunion Island, but none on the pelagic stages. This study is the first to investigate the shallow waters of the island for the diversity, abundance, and spatio-temporal distribution of jellyfish. During a one-year survey, samples were collected with a plankton net weekly or biweekly at four sites (two reef/two non-reef) and two depths (10/50 m). Of the 267 samples, 3450 medusae were sorted and 56 species identified. The meroplanktonic Hydroidolina (Antho- and Leptomedusae) were the most diverse (38 species), while the holoplanktonic Trachylinae (13 species) were the most abundant. Hydromedusa species richness was higher at coastal stations than offshore, but similar between reef and non-reef sites. There was no significant variation in species richness or abundance between months or seasons. Including some other catches, the total number of species reached 62. Eight species are new records for the Indian Ocean (all Anthomedusae). Indian Ocean literature references are given in the species list, and some photographs are provided. This initial study, which greatly expands the local hydrozoan fauna knowledge, will serve as a reference for future research, especially regarding climate change and coastal management in Reunion Island.
Patient navigation for colorectal cancer screening in deprived areas: the COLONAV cluster randomized controlled trial
Background The objective of this study was to assess the effectiveness of a Patient Navigation Intervention targeting deprived patients for Colo-Rectal Cancer (CRC) screening participation. Methods A cluster randomized controlled trial was conducted in 5 districts. Peer Lay Patient Navigators were recruited to operate in deprived areas. Eligible participants had to be between 50 and 74 years old, live in these deprived areas and receive an invitation to the nationally organized Colo-Rectal Cancer (CRC) screening during the study period. The theory-driven navigation intervention was deployed for 18 months. A population Health Intervention Research assessment method was used to assess effectiveness and context interaction. The primary criterion was screening participation at 12 months. Results Twenty-four thousand two hundred eighty-one individuals were included inside 40 clusters. The increase in participation in the intervention group was estimated at 23%, (ORa = 1.23, CI95% [1.07–1.41], p  = 0.003). For the subgroup of individuals who participated, the time delay to participating was reduced by 26% (ORa = 0.74, CI95% [0.57–0.96], p  = 0.021). Main factors modulating the effect of the intervention were: closeness of navigator profiles to the targeted population, navigators’ abilities to adapt their modus operandi, and facilitating attachment structure. Conclusion The ColoNav Intervention succeeded in demonstrating its effectiveness, for CRC screening. Patient Navigation should be disseminate with broader health promotion goals in order to achieve equity in health care. Trial registration clinicaltrials.gov NCT02369757 24/02/2015.
Morpho-molecular delineation of structurally important reef species, the fire corals, Millepora spp., at Réunion Island, Southwestern Indian Ocean
Looking at taxa that could dominate Anthropocene reefs, the fire corals, Millepora spp., represent compelling alternative because of their similar role than scleractinian corals. However, species identification has been the subject of much debate over the past 150 years. As they may turn as among the last refuges for reef biodiversity, it is critical to accurately delimit their species boundaries to appreciate better their resilience to future environmental conditions. Combining morphological and molecular approaches, we investigated Millepora species delimitation in Réunion Island where three species co-occur: Millepora exaesa, Millepora platyphylla and Millepora tenera. Our results showed that both pore characters and polyp morphologies successfully distinguished species. Gastropore and dactylopore numbers and diameters should be used as standard traits in Millepora. Regarding molecular delineation, the mitochondrial gene clearly segregated the species, whereas the nuclear gene showed shared haplotypes between species, likely influenced by ancestral polymorphism. Confirming the results of a recent study on Red Sea fire corals showing their distinction from the Indo-Pacific ones, we emphasize that formal re-descriptions of the Indo-Pacific M. cf. platyphylla and M. cf. exaesa are needed. Our study highlights the importance of a trait-based qualitative and quantitative approach coupled to molecular delineation, especially for structurally important reef species.
Cancer-related fatigue management: evaluation of a patient education program with a large-scale randomised controlled trial, the PEPs fatigue study
Background: To assess the efficacy of a patient educational program built according to guidelines that aims at reducing cancer-related fatigue (CRF). Methods: Randomised controlled trial, multicentre, comparing a patient education program, vs the standard of care. Patients were adult cancer outpatients with any tumour site. The primary outcome was fatigue severity assessed with a visual analogical scale (VAS), between the day of randomisation and week 7. Secondary outcomes were fatigue assessed with other scales, health-related quality of life, anxiety and depression. The time to fatigue severity deterioration was assessed. Analyses were performed in a modified intent-to-treat way, that is, including all patients with at least one baseline and 1 week 7 score. Results: A total of 212 patients were included. Fatigue severity assessment was made on 79 patients in the experimental group and 65 in the control group. Between randomisation and week 7, the fatigue (VAS) improved by 0.96 (2.85) points in the experimental group vs 1.63 (2.63) points in the control group ( P =0.15). No differences with the secondary outcomes were highlighted between two groups. No other factors were found to be associated with fatigue severity deterioration. Conclusions: Despite rigorous methodology, this study failed to highlight the program efficacy in fatigue reduction for cancer patients. Other assessment tools should be developed to measure the effect of the program on CRF and behaviour. The implementation of the program should also be explored in order to identify its mechanisms and longer-term impact.
Thermomechanical properties of virgin and recycled polypropylene impact copolymer/CaCO3 nanocomposites
The effect of successive injection moldings on the thermal, rheological, and mechanical properties of a polypropylene impact copolymer (PP) was investigated. The crystal content decreased as the molecular weight decreased due to chain scission with repeated injection molding. The Young modulus and the yield stress remained constant, despite a drop in the strain to break. Virgin and recycled PP matrix were filled with nanosized calcium carbonate (CaCO3) particles. The effect of morphology on the thermal and mechanical properties of nanocomposites of virgin and recycled PP filled with nanosized CaCO3 particles was also studied. The mechanical properties of the nanocomposites were strongly influenced by the intrinsic toughness of the matrix and the concentration and dispersion of the filler. The yield strength and strain of virgin PP decreased gradually, while its Young's modulus increased slightly with increasing CaCO3 loading. These phenomena were less pronounced for the recycled matrix. Incorporation of nanoparticles to virgin matrix produced an increase in tensile stiffness and ductility, when good dispersion of the filler was achieved. However, the impact strength dropped dramatically for high filler contents. A significant increase in impact strength was observed for the recycled PP. POLYM. ENG. SCI., 50:1904–1913, 2010. © 2010 Society of Plastics Engineers
ColoNav: patient navigation for colorectal cancer screening in deprived areas – Study protocol
Background The mass colorectal cancer screening program was implemented in 2008 in France, targeting 16 million French people aged between 50 and 74. The current adhesion is insufficient and the participation rate is even lower among the underserved population, increasing health inequalities within our health care system. Patient Navigation programs have proved their efficiency to promote the access to cancer screening and diagnosis. Methods/Design The purpose of the study is to assess the implementation of a patient navigation intervention that has been described in another cultural environment and another health care system. The main objective of the program is to increase the colorectal cancer screening participation rate among the deprived population through the intervention of a navigator to promote the Fecal Occult Blood Test (FOBT) and complementary exams. We performed a multisite cluster randomized controlled trial, with three groups (one experimental group and two control groups) for 18 months. Discussion The study attempts to give a better understanding of the adhesion barriers to colorectal cancer screening among underserved populations. If this project is cost-effective, it could create a dynamic based on peer approaches that could be developed for other cancer screening programs and other chronic diseases. Trial registration NCT02369757
Isolation and characterisation of 16 microsatellite loci from a widespread tropical hydrozoan, Lytocarpia brevirostris (Busk, 1852)
We isolated and characterized 16 polymorphic microsatellite loci for Lytocarpia brevirostris (Aglaopheniidae), a hydrozoan common in the tropical Indo-Pacific region. Four to 34 alleles per locus were detected at the Indo-Pacific scale. At the population level, observed ( H o ) and expected ( H e ) heterozygosities ranged across 0.100–0.625 and 0.097–0.597, respectively. Three markers showed significant deviation from Hardy–Weinberg equilibrium, all of them presenting null alleles. Linkage disequilibrium was detected in three pairs of loci among 120. These primers provide powerful tools for studying population genetic diversity and the implication of life cycle strategies on population differentiation in tropical hydrozoans. This will be valuable for the conservation of coral reefs biodiversity and the design of marine protected areas.