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Invasion of new territories by insect vector species that can transmit pathogens is one of the most important threats for human health. The spread of the mosquito Aedes albopictus in Europe is emblematic, because of its major role in the emergence and transmission of arboviruses such as dengue or chikungunya. Here, we modeled the spread of this mosquito species in France through a statistical framework taking advantage of a long-term surveillance dataset going back to the first observation of Ae. albopictus in the Metropolitan area. After validating the model, we show that human activities are especially important for mosquito dispersion while land use is a major factor for mosquito establishment. More importantly, we show that Ae. albopictus invasion is accelerating through time in this area, resulting in a geographic range extending further and further year after year. We also show that sporadic \"jump\" of Ae. albopictus in a new location far from the colonized area did not succeed in starting a new invasion front so far. Finally, we discuss on a potential adaptation to cooler climate and the risk of invasion into Northern latitudes.

The purpose of the experiment described herein is the study of material deformation (here a cylinder) induced by explosives. During its expansion, the cylinder (initially 3 mm thick) is thinning until fracture appears. Some tens of microseconds before destruction, strain localizations occur and induce mechanical necking. To characterize the time of first localizations, 25 stereoscopic acquisitions at about 500,000 frames per second are used by resorting to a single ultra-high speed camera. The 3D reconstruction from stereoscopic movies is described. A special calibration procedure is followed, namely, the calibration target is imaged during the experiment itself. To characterize the performance of the present procedure, resolution and optical distortions are estimated. The principle of stereoscopic reconstruction of an object subjected to a high-speed experiment is then developed. This reconstruction is achieved by using a global image correlation code that exploits random markings on the object outer surface. The spatial resolution of the estimated surface is evaluated thanks to a realistic image pair synthesis. Last, the time evolution of surface roughness is estimated. It gives access to the onset of necking.

Background Colonization of large part of Europe by the Asian tiger mosquito Aedes albopictus is causing autochthonous transmission of chikungunya and dengue exotic arboviruses. While pyrethroids are recommended only to reduce/limit transmission, they are widely implemented to reduce biting nuisance and to control agricultural pests, increasing the risk of insurgence of resistance mechanisms. Worryingly, pyrethroid resistance (with mortality < 70%) was recently reported in Ae. albopictus populations from Italy and Spain and associated with the V1016G point mutation in the voltage-sensitive sodium channel gene conferring knockdown resistance ( kdr ). Genotyping pyrethroid resistance-associated kdr mutations in field mosquito samples represents a powerful approach to detect early signs of resistance without the need for carrying out phenotypic bioassays which require availability of live mosquitoes, dedicated facilities and appropriate expertise. Methods Here we report results on the PCR-genotyping of the V1016G mutation in 2530 Ae. albopictus specimens from 69 sampling sites in 19 European countries. Results The mutation was identified in 12 sites from nine countries (with allele frequencies ranging from 1 to 8%), mostly distributed in two geographical clusters. The western cluster includes Mediterranean coastal sites from Italy, France and Malta as well as single sites from both Spain and Switzerland. The eastern cluster includes sites on both sides of the Black Sea in Bulgaria, Turkey and Georgia as well as one site from Romania. These results are consistent with genomic data showing high connectivity and close genetic relationship among West European populations and a major barrier to gene flow between West European and Balkan populations. Conclusions The results of this first effort to map kdr mutations in Ae. albopictus on a continental scale show a widespread presence of the V1016G allele in Europe, although at lower frequencies than those previously reported from Italy. This represents a wake-up call for mosquito surveillance programs in Europe to include PCR-genotyping of pyrethroid resistance alleles, as well as phenotypic resistance assessments, in their routine activities. Graphical Abstract

Background With the worldwide spread of the Asian tiger mosquito, Aedes albopictus , the number of autochthonous cases of exotic arboviral diseases, such as dengue or chikungunya, is increasing in temperate regions. In Europe, pyrethroids are the only insecticides allowed for the abatement of adult mosquitoes and are thus crucial for limiting ongoing arbovirus transmission. Despite this and the report of resistance rising in vector populations worldwide, information on the pyrethroid resistance status of vector populations and knowledge on resistance mechanisms is widely lacking. Genotyping of knockdown resistance ( kdr ) mutations situated within the target site of pyrethroids, i.e., the voltage-gated sodium channel (VGSC), and associated with pyrethroid resistance, is a cost-effective approach to investigate the spread of resistance in a population. Herein, we describe the European-wide distribution of two kdr mutations, i.e., I1532T and F1534C, in Ae. albopictus and evaluate their co-occurrence with another well-characterized kdr mutation, V1016G. Methods Genotyping of the kdr mutation F1534C was performed by allele-specific PCR for 1732 Ae. albopictus specimens sampled in 19 European countries; for a subset of 419 specimens mutation I1532T was also genotyped by sequencing. For all samples, information on mutation V1016G was available, allowing evaluation of the co-occurrence of kdr alleles. Results Mutation 1534C was detected in nine sites from six countries at an overall frequency close to 5%. Highest frequencies per site were detected in Cyprus (84%) and Greece (45%). Allele 1532 T was identified in 11 sites from 7 countries at frequencies ranging from 4% to 25% per site. Co-occurrence of different kdr alleles (1534C, 1532 T and 1016G) was observed in nine sampling sites from seven countries. Conclusions The present study offers the first map of the occurrence of the major Ae. albopictus kdr alleles across Europe and highlights a differential distribution of the two alleles most strongly associated with pyrethroid resistance, 1016G and 1534C. Our findings also point to the need for enhancing resistance monitoring in the Eastern Mediterranean region, where the two mutations are shown to exist in geographically close areas, with the risk of emergence of highly resistant double mutants. Graphical Abstract

The Asian tiger mosquito, Aedes albopictus, is currently the most widespread invasive mosquito species in the world. It poses a significant threat to human health, as it is a vector for several arboviruses. We used a SNP chip to genotype 748 Ae. albopictus mosquitoes from 41 localities across Europe, 28 localities in the native range in Asia, and 4 in the Americas. Using multiple algorithms, we examined population genetic structure and differentiation within Europe and across our global dataset to gain insight into the origin of the invasive European populations. We also compared results from our SNP data to those obtained using genotypes from 11 microsatellite loci (N = 637 mosquitoes from 25 European localities) to explore how sampling effort and the type of genetic marker used may influence conclusions about Ae. albopictus population structure. While some analyses detected more than 20 clusters worldwide, we found mosquitoes could be grouped into 7 distinct genetic clusters, with most European populations originating in East Asia (Japan or China). Interestingly, some populations in Eastern Europe did not share genetic ancestry with any populations from the native range or Americas, indicating that these populations originated from areas not sampled in this study. The SNP and microsatellite datasets found similar patterns of genetic differentiation in Europe, but the microsatellite dataset could not detect the more subtle genetic structure revealed using SNPs. Overall, data from the SNP chip offered a higher resolution for detecting the genetic structure and the potential origins of invasions. The Asian tiger mosquito, Aedes albopictus, is currently the most widespread invasive mosquito species in the world and poses a significant threat to human health. We genotyped 748 Ae. albopictus mosquitoes from locations across Europe and Asia (the native range) to examine population genetic structure and found evidence for multiple independent invasions into Europe from both the native region and other areas of the invasive range. SNP and microsatellite datasets found similar patterns of genetic differentiation in Europe, but the microsatellite dataset could not detect the more subtle genetic structure revealed using SNPs.

Sprays of commercial preparations of the bacterium Bacillus thuringiensis subsp. israelensis are widely used for the control of mosquito larvae. Despite an abundant literature on B. thuringiensis subsp. israelensis field efficiency on mosquito control, few studies have evaluated the fate of spores in the environment after treatments. In the present article, two complementary experiments were conducted to study the effect of different parameters on B. thuringiensis subsp. israelensis persistence and recycling, in field conditions and in the laboratory. First, we monitored B. thuringiensis subsp. israelensis persistence in the field in two contrasting regions in France: the Rhône-Alpes region, where mosquito breeding sites are temporary ponds under forest cover with large amounts of decaying leaf matter on the ground and the Mediterranean region characterized by open breeding sites such as brackish marshes. Viable B. thuringiensis subsp. israelensis spores can persist for months after a treatment, and their quantity is explained both by the vegetation type and by the number of local treatments. We found no evidence of B. thuringiensis subsp. israelensis recycling in the field. Then, we tested the effect of water level, substrate type, salinity and presence of mosquito larvae on the persistence/recycling of B. thuringiensis subsp. israelensis spores in controlled laboratory conditions (microcosms). We found no effect of change in water level or salinity on B. thuringiensis subsp. israelensis persistence over time (75 days). B. thuringiensis subsp. israelensis spores tended to persist longer in substrates containing organic matter compared to sand-only substrates. B. thuringiensis subsp. israelensis recycling only occurred in presence of mosquito larvae but was unrelated to the presence of organic matter.

Invasion of new territories by insect vector species that can transmit pathogens is one of the most important threats for human health. The spread of the mosquito Aedes albopictus in Europe is emblematic, because of its major role in the emergence and transmission of arboviruses such as dengue or chikungunya. Here, we modeled the spread of this mosquito species in France through a statistical framework taking advantage of a long-term surveillance dataset going back to the first observation of Ae. albopictus in the Metropolitan area. After validating the model, we show that human activities are especially important for mosquito dispersion while land use is a major factor for mosquito establishment. More importantly, we show that Ae. albopictus invasion is accelerating through time in this area, resulting in a geographic range extending further and further year after year. We also show that sporadic \"jump\" of Ae. albopictus in a new location far from the colonized area did not succeed in starting a new invasion front so far. Finally, we discuss on a potential adaptation to cooler climate and the risk of invasion into Northern latitudes.

The purpose of the experiment described herein is the study of material deformation (here a cylinder) induced by explosives. During its expansion, the cylinder (initially 3 mm thick) is thinning until fracture appears. Some tens of microseconds before destruction, strain localizations occur and induce mechanical necking. To characterize the time of first localizations, 25 stereoscopic acquisitions at about 500,000 frames per second are used by resorting to a single ultra-high speed camera. The 3D reconstruction from stereoscopic movies is described. A special calibration procedure is followed, namely, the calibration target is imaged during the experiment itself. To characterize the performance of the present procedure, resolution and optical distortions are estimated. The principle of stereoscopic reconstruction of an object subjected to a high-speed experiment is then developed. This reconstruction is achieved by using a global image correlation code that exploits random markings on the object outer surface. The spatial resolution of the estimated surface is evaluated thanks to a realistic image pair synthesis. Last, the time evolution of surface roughness is estimated. It gives access to the onset of necking.

Background Medical students often encounter challenges in maintaining healthy habits. The Preventive Remediation for Optimal MEdical StudentS (PROMESS) project seeks to support students to adopt healthier lifestyles throughout their curriculum by implementing a program focused on three modules (stress, sleep, and physical activity). Prior to implementation, it was essential to gain insights into students' needs. For this purpose, a comprehensive approach was adopted to ensure that the proposed program aligns with students’ needs, to identify barriers and facilitators for implementation, to propose adjustments, and to test the program. Methods A three-step study was conducted. First, two focus groups sessions, one involving students and the other involving university staff members were conducted to identify medical students' needs and obstacles to change regarding their health. After verbatim transcription, a framework thematic analysis was performed with the use of MAXQDA. Second, a co-construction workshop was conducted with participants from both groups to develop the PROMESS program. Third, some of the medical students who participated in the prior steps tested the co-constructed program. The study was conducted at the Lyon-Est Faculty of Medicine (France, IRB2023070404). Results (i) The medical students cited a heavy academic workload and demanding internships as the main factors that contribute to their limited selfcare, heightened stress levels and sleep disruptions, and reduced physical activity. The university staff members noted that students struggled to acknowledge their needs, accept limitations, and seek assistance. (ii) The participants provided advice for adapting PROMESS program to the students’ specific needs (e.g., individualized advice, one-on-one meetings, peer coaching, and signing a commitment contract). (iii) The students who tested the program reported being more aware of their health behaviors and reported improvement in stress levels, sleep, and physical activity. They believed that the changes could be long-lasting. Conclusion This study identified barriers to changes in medical students’ behaviors that affect their health. The co-construction workshop and the pilot study facilitated program development and enhanced its feasibility and acceptability for broader implementation. This three-step approach highlights the importance of engaging various stakeholders to craft complex health interventions for medical students.

Dozens of missed recessive loci affecting homozygous carriers' life expectancy were recently reported. This article details the clinical, biological and pathological manifestations of a new bovine genetic disorder caused by the ITGB7 p.G375S point mutation in the French Holstein cattle breed (BLIRD: OMIA:002872-9913). Our thorough study involved database analysis of genotyped cattle and a series of case-control investigations of forty individuals homozygous for the causative variant. These variant homozygotes had a significantly shorter lifespan (fewer than 64% surviving past three years vs. 87% in control), along with reduced body weight, daily weight gain, and dairy performance. The mutation did not affect most biochemical parameters, but a marked lymphocytic leucocytosis, moderate eosinophilia and differences in faecal microbiota were observed. Although non-pathognomonic symptoms may be confused with those of common environmental diseases, the blood profile effectively identified suspected carriers who developed ill-thrift and poor growth as heifers. Our research demonstrates that the bovine ITGB7 p.G375S substitution leads to reduced longevity, poor condition and production in most homozygous carriers. Furthermore, this spontaneous model may help to refine the functions of the integrin β7 (ITGB7) in immune homeostasis and defence.