HAL Université des Antilles
Not a member yet
25497 research outputs found
Sort by
Immunological surveillance using gSG6-P1 biomarker reveals spatio-temporal dynamics of Anopheles exposure and gaps in malaria risk assessment
No full textInternational audienceMalaria risk assessment often relies on the entomological inoculation rate (EIR), which quantifies infectious bites per person over time. However, this approach does not account for human behavioral variability, limiting its effectiveness in accurately reflecting malaria risk at the population level. Recent studies have attempted to estimate mosquito-bite risk through the measurement of antibody responses to Anopheles salivary peptides. However, this approach has yet to be applied to evaluate malaria transmission risks along the Thailand-Cambodia border. This study aims to employ an immune biomarker for Anopheles salivary peptide (anti-gSG6-P1) to identify key risk factors associated with exposure to Anopheles mosquitoes in Sisaket Province, a region bordering Thailand and Cambodia. Blood samples from the same set of 184 participants were collected via finger prick during each season: rainy (August 2022), cool-dry (December 2022), and hot-dry (April 2023). Anti-gSG6-P1 antibody levels were quantified using enzyme-linked immunosorbent assay (ELISA). Factor Analysis of Mixed Data (FAMD) revealed that seasonality exerts the strongest influence on antibody levels. This pattern was likely driven by human activities, particularly the frequency of rubber tapping activity in the rubber plantation area where Anopheles species, especially Anopheles dirus, are present. While this study successfully identifies seasonality and human factors as critical influences on antibody responses, it also highlights gaps in understanding the kinetics of anti-salivary peptide responses to Anopheles bites, particularly in species with low salivary peptides sequence similarity to that of Anopheles gambiae. These findings emphasize the need for the development of new serological tools tailored to malaria vectors in the Greater Mekong Subregion to enhance malaria risk assessment and improve vector control strategies
Une nouvelle espèce du genre Archaeoananteroides Lourenço, 2016, scorpion fossile de l’ambre Crétacé de Myanmar (Scorpiones: Buthoidea: Ananteridae)
No full textInternational audienceA second species of fossil scorpion belonging to the rare genus ArchaeoananteroidesLourenço, 2016, is described from the Cretaceous amber of Myanmar (Burma). The genusArchaeoananteroides was the first fossil scorpion to be described from Burmite which showed some clearly relationships with extant buthoids and, in particular with the extant genus Ananteroides Borelli, 1911. The genus Archaeoananteroides appeared to be in a less basal position than that of the elements of the family Palaeoburmesebuthidae Lourenço. The description of a second species for this genus brings further evidence to the validity of the genus Archaeoananteroides and once again confirms the high degree of diversity present in the Burmese amber-producing forests.Une deuxième espèce de scorpion fossile appartenant au rare genre Archaeoananteroides Lourenço, 2016, est décrite de l’ambre Crétacé du Myanmar. Le genre Archaeoananteroides a été le premier scorpion fossile décrit de ce type d’ambre, présentant des claires affinitésavec les Buthoidea modernes, et en particulier avec le genre Ananteroides Borelli, 1911. Le genre Archaeoananteroides semble être situé dans une position moins basale que celle des éléments de la famille des Palaeoburmesebuthidae Lourenço. La description d’unedeuxième espèce pour ce genre apporte un argument supplémentaire à la validité des Archaeoananteroides et une fois de plus confirme la très grande diversité scorpionique présente dans les forêts Crétacés productrices d’ambre
Century-old herbarium specimen provides insights into Pierce’s disease of grapevines emergence in the Americas
No full textInternational audienceFossils and other preserved specimens are integral for informing timing and evolutionary history in every biological system. By isolating a plant pathogen genome from herbarium-preserved diseased grapevine material from 1906 (Herb_1906), we were able to answer questions about an enigmatic system. The emergence of Pierce’s disease (PD) of grapevine has shaped viticultural production in North America; yet, there are uncertainties about the geographic origin of the pathogen (Xylella fastidiosa subsp. fastidiosa, Xff) and the timing and route of its introduction. We produced a high-quality, de novo genome assembly of this historical plant pathogen and confirmed degradation patterns unique to ancient DNA. Due to the inclusion of the Herb_1906 sample, we were able to generate a significant temporal signal in the genomic data. This allowed us to build a time-calibrated phylogeny, where we estimate the introduction of Xff into the US between 1734 and 1741 CE, an earlier time frame than previously inferred. In a large collection of >300 Xff genomes, the Herb_1906 sample was genetically most similar to a small population from Northern California but not basal to the entire Xff California clade. Based on phylogenetic placement and a phylogeographic reconstruction, our data support a single introduction of Xff into the Southeastern US from Central America, with multiple subsequent introductions into California
Infirmiers en pratique avancée : un levier de santé publique pour l'accès, la qualité et l'efficience des soins : une revue parapluie
No full textInternational audienc
Des parasites découverts chez les vers plats envahissants, enfin une piste de lutte ?
No full textInternational audienc
Evaluating topological variability in Neodermata phylogenies using mitochondrial and ribosomal gene markers
No full textInternational audienceThe Neodermata is a group of parasitic flatworms that includes the classes Trematoda, Cestoda, and Monogenea. Understanding the phylogenetic relationships within the Neodermata has been a longstanding challenge. Molecular studies utilizing different datasets have produced variable results, leading to differing evolutionary hypotheses. Resolving the phylogenetic relationships requires careful consideration of the molecular targets and sequences used. In this study, our objective was to investigate the topological variability of phylogenetic trees by examining different mitochondrial genes, molecular datasets (nucleotides and amino acids), as well as the 18S and 28S nuclear rRNA genes, and three software packages used for phylogenetic analysis. To evaluate the utility of different markers, we constructed 96 unilocus trees and nine multilocus trees. Our findings revealed that each gene provided unique information and resulted in different topologies depending on the sequences used, with only few mitochondrial genes indicating the monophyly of the Monogenea. Multilocus analyses mitochondrial and mitochondrial + 18S + 28S produced a consistent topology, supporting the monophyly of each of the four major neodermatan lineages (Cestoda, Trematoda, Monopisthocotylea, and Polyopisthocotylea). Notably, the monophyly of the Polyopisthocotylea and Cestoda consistently appeared in the different analyses. Conversely, we observed discrepancies between results obtained from mitochondrial genes and nuclear genes. This study contributes to our understanding of the phylogeny of the Neodermata by examining the topological variability of phylogenetic trees using both mitochondrial and nuclear genes. Our results emphasize that carefully selected molecular markers and multilocus approaches are crucial for illuminating the complex evolutionary history within the Neodermata
Identification of new antimicrobial peptides in Armadillidium vulgare using PepTraq.
No full textInternational audienceSeveral antimicrobial peptides have been discovered in the model organisms, the common woodlouse Armadillidium vulgare. More generally, The EBI team has already identified 110 ALFs (anti-lipopolysaccharide factors), 73 crustins and 18 armadillidins in the Armadillidiidae and Porcellionidae1. Nevertheless, although important, this repertoire is still far from reflecting the diversity and abundance of peptides that can be found in a given species, as shown by the literature on other less conventional Arthropod models such as the tobacco sphinx2 or the black soldier fly3. In order to establish a more exhaustive repertoire of the defence molecules present in A. vulgare, we have developed two complementary methodologies as part of the PHARMA project. The first is a targeted in-silico approach consisting of searching for PAMs in the A. vulgare genome using the PepTraq4 software developed at the University of Caen https://peptraq.greyc.fr/. The second approach consisted in studying the evolution of the proteome of A. vulgare hemolymph in the presence of salmonella. In both approaches, precursors ranging from 50 to 200 amino acids in length were targeted, presenting a signal peptide and characteristics common to certain categories of crustacean PAMs, such as a high proline, glycine or cysteine content. Several promising sequences were identified, including a double β-defensin and a scorpin-related peptide.Références :1.Becking T, Delaunay C, Cordaux R, Berjeaud JM, Braquart-Varnier C, Verdon J. . (2020)Shedding Light on the Antimicrobial Peptide Arsenal of Terrestrial Isopods: Focus on Armadillidins, a New Crustacean AMP Family. Genes (Basel). 14;11(1):93. doi: 10.3390/genes11010092.He Y, Cao X, Li K, Hu Y, Chen YR, Blissard G, Kanost MR, Jiang H. (2015)A genome-wide analysis of antimicrobial effector genes and their transcript
Political Corruption and Family Businesses: An Empirical Study of Bribery Payments in Tunisia
No full textInternational audienceThis research examines the impact of family involvement in firms on their propensity to engage in corrupt practices, specifically through the payment of bribes to public officials or politicians. The influence of the weakness of the institutional context on this relationship was also tested. This framework was tested using data from 459 family firms in Tunisia that participated in the European Bank for Reconstruction and Development, the European Investment Bank and the World Bank Group Enterprise Survey conducted between September 2019 and July 2020. The results show mixed effects of family involvement on the propensity to pay bribes. While family ownership has a negative impact on political corruption, family involvement in management has a positive impact. Furthermore, in an environment where institutional frameworks are weak, strong family involvement in management seems to be associated with a lower propensity for political corruption
LPM·Net. Deux réseaux denses de suivi long terme de la pression lumineuse à La Réunion et en Brière
No full textNational audienceLes réseaux denses de capteurs photométriques fournissent des données à haute fréquence et haute résolution, à des échelles spatiales inédites. Ils permettent de détecter les variations lumineuses sur des périodes allant de la minute à plusieurs années, offrant ainsi des évaluations fines à court comme à long terme, tout en améliorant les modèles de halo lumineux et de transfert radiatif. Ils rendent possible une analyse détaillée des politiques d’éclairage — qu’il s’agisse de transitions vers les LED ou de mesures de gradation — en suivant leurs effets sur la luminosité du ciel. Ces systèmes assurent également une surveillance quasi continue des variations de l’ALAN en lien avec les conditions atmosphériques, notamment les aérosols et la couverture nuageuse, et contribuent à la validation des données satellitaires ainsi qu’à l’évaluation des impacts écologiques et sanitaires. Cette contribution présente des jeux de données haute résolution issus de deux réseaux denses de capteurs TESS-W déployés pour un suivi à long terme de l’ALAN : (1) à La Réunion, territoire volcanique de l’océan Indien, caractérisé par une forte biodiversité et un littoral en urbanisation rapide ; et (2) dans la région de la Brière, vaste zone humide de la façade atlantique française, intégrée dans un parc naturel régional et abritant des écosystèmes nocturnes sensibles. Ces réseaux produisent des mesures continues et pluriannuelles de la luminosité du ciel nocturne, à des résolutions spatiales de l’ordre du kilomètre et temporelles de l’ordre de la minute. Nous décrivons l’architecture des réseaux, les procédures d’étalonnage, la chaîne de traitement des données et les modalités d’accès. En rendant ces jeux de données ouverts, ce travail renforce les capacités de suivi de la pollution lumineuse et l’évaluation de l’efficacité des stratégies de réduction. Conçus dans le cadre de l’Observatoire de l’environnement nocturne du CNRS, ces dispositifs offrent une base empirique solide pour analyser les dynamiques multiples de la pollution lumineuse dans leurs dimensions atmosphériques, écologiques, socioculturelles et territoriales. Ils contribuent également aux démarches d’éducation à l’environnement, favorisant une prise de conscience élargie et une mobilisation collective en faveur de la préservation de l’environnement nocturne
Better to be bitten by a wolf or a dog? A quantitative comparative study of the jaw adductors architecture in wild and domestic canids
No full textInternational audienceVariability in the jaw musculature of canids has been studied in various species, including domestic dogs. Previous research suggests that despite significant morphological variation due to artificial selection, muscle architecture remains relatively stable in domestic dogs. However, the variability in the jaw musculature of wild grey wolves remains unexplored, primarily due to the difficulty of obtaining fresh cadavers. Here, we compare the muscle architecture (mass and physiological cross-sectional area) of a large sample of domestic dogs (n = 83) with that of French wolves (n = 91) and Alaskan wolves (n = 14). Our results reveal that wolves have a greater proportion of masseter muscle PCSA relative to total jaw adductors musculature, with values overlapping those observed in dog breeds selected for defense or attack (e.g., Mastiffs, Pit Bulls, and Dobermans). This adaptation likely enhances their ability to generate greater bite force at low jaw-opening angles, which is crucial for wolves when cracking the bones of large prey-deer constituting 55% and 75% of the diet in French and Alaskan wolves, respectively. Similarly, attack dogs benefit from this trait for capturing and restraining prey or threats. This study provides new insights into how natural selection shapes the jaw apparatus of wild canids and highlights the impact of artificial selection on domestic breeds