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  • Publications
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  • 2013-2022
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  • Hal-Diderot
  • Mémoires en Sciences de l'Information et de la Communication
  • COVID-19

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  • Open Access
    Authors: 
    Viktor K. Jirsa; Spase Petkoski; Huifang Wang; Michael Marmaduke Woodman; Jan Fousek; Cornelia Betsch; Lisa Felgendreff; Robert Böhm; Lau Lilleholt; Ingo Zettler; +3 more
    Publisher: Public Library of Science (PLoS)
    Country: France
    Project: EC | HBP SGA3 (945539)

    SummaryDuring the current COVID-19 pandemic, governments must make decisions based on a variety of information including estimations of infection spread, health care capacity, economic and psychosocial considerations. The disparate validity of current short-term forecasts of these factors is a major challenge to governments. By causally linking an established epidemiological spread model with dynamically evolving psychosocial variables, using Bayesian inference we estimate the strength and direction of these interactions for German and Danish data of disease spread, human mobility, and psychosocial factors based on the serial cross-sectional COVID-19 Snapshot Monitoring (COSMO;N= 16,981). We demonstrate that the strength of cumulative influence of psychosocial variables on infection rates is of a similar magnitude as the influence of physical distancing. We further show that the efficacy of political interventions to contain the disease strongly depends on societal diversity, in particular group-specific sensitivity to affective risk perception. As a consequence, the model may assist in quantifying the effect and timing of interventions, forecasting future scenarios, and differentiating the impact on diverse groups as a function of their societal organization. Importantly, the careful handling of societal factors, including support to the more vulnerable groups, adds another direct instrument to the battery of political interventions fighting epidemic spread.

  • Open Access English
    Authors: 
    Yuxin Song; Xuan-Nhi Nguyen; Anuj Kumar; Claire da Silva; Léa Picard; Lucie Etienne; Andrea Cimarelli;
    Publisher: HAL CCSD
    Country: France
    Project: ANR | ECOFECT (ANR-11-LABX-0048)

    ABSTRACTTo identify novel cellular modulators of HIV-1 infection in IFN-stimulated myeloid cells, we have carried out a screen that combines functional and evolutionary analyses in THP-1-PMA cells that led us to the Tripartite Motif Protein 69 (Trim69), a poorly studied member of the Trim family of innate immunity regulators. Trim69 inhibits HIV-1, primate lentiviruses and the negative and positive-strand RNA viruses VSV and SARS-CoV2, overall indicating it is a broad-spectrum antiviral factor. Trim69 binds directly to microtubules and its antiviral activity is intimately linked to its ability to promote the accumulation of stable MTs, a specialized subset of microtubules. By analyzing the behavior of primary blood cells, we provide evidence that a program of MT stabilization is commonly observed in response to IFN-I in cells of the myeloid lineage and Trim69 is the key factor behind this program.Overall, our study identifies Trim69 as the first antiviral innate defense factor that regulates the properties of microtubules to limit viral spread, highlighting the possibility that the cytoskeleton may be a novel unappreciated fighting ground in the host-pathogen interactions that underlie viral infections.

  • Open Access
    Authors: 
    Philippe Colson; Jérémy Delerce; Mamadou Beye; Anthony Levasseur; Céline Boschi; Linda Houhamdi; Hervé Tissot‐Dupont; Nouara Yahi; Matthieu Million; Bernard La Scola; +3 more
    Publisher: Wiley
    Country: France

    ABSTRACTThe SARS-CoV-2 21K/BA.1, 21L/BA.2, and BA.3 Omicron variants have recently emerged worldwide. To date, the 21L/BA.2 Omicron variant has remained very minority globally but became predominant in Denmark instead of the 21K/BA.1 variant. Here we describe the first cases diagnosed with this variant in south-eastern France. We identified thirteen cases using variant-specific qPCR and next-generation sequencing between 28/11/2021 and 31/01/2022, the first two cases being diagnosed in travellers returning from Tanzania. Overall, viral genomes displayed a mean (±standard deviation) number of 65.9±2.5 (range, 61-69) nucleotide substitutions and 31.0±8.3 (27-50) nucleotide deletions, resulting in 49.6±2.2 (45-52) amino acid substitutions (including 28 in the spike protein) and 12.4±1.1 (12-15) amino acid deletions. Phylogeny showed the distribution in three different clusters of these genomes, which were most closely related to genomes from England and South Africa, from Singapore and Nepal, or from France and Denmark. Structural predictions pointed out a significant enlargement and flattening of the 21L/BA.2 N-terminal domain surface compared with that of the 21K/BA.2 Omicron variant, which may facilitate initial viral interactions with lipid rafts. Close surveillance is needed at global, country and center scales to monitor the incidence and clinical outcome of the 21L/BA.2 Omicron variant.

  • Open Access
    Authors: 
    Ucheoma Nwaozuru; Chisom Obiezu-Umeh; Hassim Diallo; Danielle Graham; Guy-Lucien Whembolua; Marie Janeeca Bourgeau; Tiarney D. Ritchwood; LaRon E. Nelson; Thembekile Shato; Allison Mathews; +6 more
    Publisher: Research Square Platform LLC
    Country: France

    Abstract Background COVID-19 self-testing (ST) is an innovative strategy with the potential to increase the access and uptake of testing and ultimately to limit the spread of the virus. To maximize the uptake and reach of this promising strategy and inform intervention development and scale up, research is needed to understand the acceptability of and willingness to use this tool. This is vital to ensure that Black/African Americans are reached by the Biden-Harris Administration’s free national COVID-19 ST program. This study aimed to explore the acceptability and recommendations to promote and scale-up the uptake of COVID-19 ST among Black/African Americans. Methods We conducted a cross-sectional qualitative study using a semi-structured questionnaire to assess barriers and facilitators to the uptake of COVID-19 ST among a convenience sample of 28 self-identified Black/African Americans from schools, community centers, and faith-based institutions in Ohio and Maryland. Inductive content analysis was conducted to identify categories and subcategories related to acceptability and recommendations for implementing and scaling up COVID-19 ST in communities. Results Participants perceived COVID-19 self-testing as an acceptable tool that is beneficial to prevent transmission and address some of the barriers associated with health facility testing, such as transportation cost and human contact at the health facility. However, concerns were raised regarding the accurate use of the kits and costs. Recommendations for implementing and scaling up COVID-19 ST included engagement of community stakeholders to disseminate information about COVID-19 self-testing and creating culturally appropriate education tools to promote knowledge of and clear instructions about how to properly use COVID-19 ST kits. Based on these recommendations, the COVID-19 STEP (Self-Testing Education and Promotion) Project is being developed and will involve engaging community partners such as barbers, church leaders, and other community-based organizations to increase the uptake and use of free COVID-19 ST kits among Black/African Americans. Conclusion Findings showed that most participants considered COVID-19 ST valuable for encouraging COVID-19 testing. However, cost and accuracy concerns may pose barriers. Future work should consider implementing interventions that leverage the benefits of COVID-19 ST and further assess the extent to which these identified facilitators and barriers may influence COVID-19 ST uptake.

  • Open Access
    Authors: 
    Alban, Frederique; Sophie LEONARDI; Pascal, Le Floc H.;
    Country: France

    Les halles à marée, présentes sur tout le littoral métropolitain, sont les premiers marchés pour les produits de la mer débarqués par les flottilles de pêche. La question posée porte sur la capacité d’adaptation des halles à marée face aux fluctuations de l’offre et des cours du poisson provoquées par le premier confinement et amplifiées par le second en 2020. A l’échelle nationale, le chiffre d’affaires des premiers marchés a décliné de 18% par rapport à la moyenne des trois années précédentes. La méthode de décomposition du chiffre d’affaires démontre que la valeur des productions traduit une stratégie de quantité et plus rarement une action sur les prix. Des enquêtes auprès des responsables de halles à marée apportent une lecture complémentaire à celle des statistiques de vente, parfois même une lecture différente. La discussion des résultats soulève deux questions majeures. La première traite du biais informationnel quand on limite l’analyse à une approche quantitative des statistiques de production. La seconde pose la question de la menace potentielle des ventes directes sur les halles à marée. C’est l’occasion pour les responsables de criée de rappeler les garanties qu’ils offrent en termes de traçabilité des produits. The fish markets, which are present all along the coast of Metropolitan France, are the primary markets for the seafood products landed by the fishing fleets. The question raised concerns the capacity of the fish markets to adapt to the fluctuations in supply and fish prices caused by the first confinement and amplified by the second in 2020. On a domestic scale, the turnover of the first markets declined by 18% compared to the average of the previous three years. The method of breaking down turnover shows that the value of production reflects a strategy on quantity and more rarely a price policy. Surveys of fish market managers provide a complementary understanding to that of the sales statistics, sometimes even a different reading. The discussion of the results raises two major questions. The first deals with the informational bias when the analysis is limited to a quantitative approach to production statistics. The second is the question of the potential threat of direct sales to fish markets. This is an opportunity for the executives of the fish market to claim the guarantees they offer in terms of goods traceability.

  • Open Access English
    Authors: 
    Emma Hubert; Thibaut Mastrolia; Dylan Possamaï; Xavier Warin;
    Publisher: HAL CCSD
    Countries: United States, France
    Project: ANR | PACMAN (ANR-16-CE05-0027)

    In this work, we provide a general mathematical formalism to study the optimal control of an epidemic, such as the COVID-19 pandemic, via incentives to lockdown and testing. In particular, we model the interplay between the government and the population as a principal-agent problem with moral hazard, à la Cvitanić et al. (Finance Stoch 22(1):1-37, 2018), while an epidemic is spreading according to dynamics given by compartmental stochastic SIS or SIR models, as proposed respectively by Gray et al. (SIAM J Appl Math 71(3):876-902, 2011) and Tornatore et al. (Phys A Stat Mech Appl 354(15):111-126, 2005). More precisely, to limit the spread of a virus, the population can decrease the transmission rate of the disease by reducing interactions between individuals. However, this effort-which cannot be perfectly monitored by the government-comes at social and monetary cost for the population. To mitigate this cost, and thus encourage the lockdown of the population, the government can put in place an incentive policy, in the form of a tax or subsidy. In addition, the government may also implement a testing policy in order to know more precisely the spread of the epidemic within the country, and to isolate infected individuals. In terms of technical results, we demonstrate the optimal form of the tax, indexed on the proportion of infected individuals, as well as the optimal effort of the population, namely the transmission rate chosen in response to this tax. The government's optimisation problems then boils down to solving an Hamilton-Jacobi-Bellman equation. Numerical results confirm that if a tax policy is implemented, the population is encouraged to significantly reduce its interactions. If the government also adjusts its testing policy, less effort is required on the population side, individuals can interact almost as usual, and the epidemic is largely contained by the targeted isolation of positively-tested individuals.

  • Open Access English
    Authors: 
    Alexis Descatha; Grace Sembajwe; Fabien Gilbert; Marc Fadel;
    Publisher: Multidisciplinary Digital Publishing Institute
    Country: France

    Background. We aimed to assess the validity of the Mat-O-Covid Job Exposure Matrix (JEM) on SARS-CoV2 using compensation data from the French National Health Insurance compensation system for occupational-related COVID-19. Methods. Deidentified compensation data for occupational COVID-19 in France were obtained between August 2020 and August 2021. The acceptance was considered as the reference. Mat-O-Covid is an expert based French JEM on workplace exposure to SARS-CoV2. Bivariate and multivariate models were used to study the association between the exposure assessed by Mat-O-Covid and the reference, as well as the Area Under Curves (AUC), sensitivity, specificity, predictive values, and likelihood ratios. Results. In the 1140 cases included, there was a close association between the Mat-O-Covid index and the reference (p<0.0001). The overall predictivity was good, with an AUC of 0.78 and an optimal threshold at 13 per thousand. Using Youden’s J statistic resulted in 0.67 sensitivity and 0.87 specificity. Both positive and negative likelihood ratios were significant: respectively 4.9 [2.4-6.4] and 0.4 [0.3-0.4]. Discussion. It was possible to assess Mat-O-Covid’s validity using data from the national compensation system for occupational COVID-19. Though further studies are needed, Mat-O-Covid exposure assessment appears to be accurate enough to be used in research.

  • Open Access English
    Authors: 
    Houcemeddine Othman; Houcemeddine Othman; Haifa Ben Messaoud; Oussema Khamessi; Hazem Ben-Mabrouk; Kais Ghedira; Avani Bharuthram; Florette Treurnicht; Ikechukwu Achilonu; Yasien Sayed; +1 more
    Publisher: HAL CCSD
    Country: France
    Project: EC | PHINDaccess (811034)

    AbstractThe Receptor Binding Domain (RBD) of SARS-CoV-2 virus harbors a sequence of Arg-Gly-Asp tripeptide named RGD motif, which has also been identified in extracellular matrix proteins that bind integrins as well as other disintegrins and viruses. Accordingly, integrins have been proposed as host receptors for SARS-CoV-2. The hypothesis was supported by sequence and structural analysis. However, given that the microenvironment of the RGD motif imposes structural hindrance to the protein-protein association, the validity of this hypothesis is still uncertain. Here, we used normal mode analysis, accelerated molecular dynamics microscale simulation, and protein-protein docking to investigate the putative role of RGD motif of SARS-CoV-2 RBD for interacting with integrins. We found, by molecular dynamics, that neither RGD motif nore its microenvironment show any significant conformational shift in the RBD structure. Highly populated clusters were used to run a protein-protein docking against three RGD-binding integrin types, showing no capability of the RBD domain to interact with the RGD binding site. Moreover, the free energy landscape revealed that the RGD conformation within RBD could not acquire an optimal geometry to allow the interaction with integrins. Our results highlighted different structural features of the RGD motif that may prevent its involvement in the interaction with integrins. We, therefore, suggest, in the case where integrins are confirmed to be the direct host receptors for SARS-CoV-2, a possible involvement of other residues to stabilize the interaction.

  • Open Access English
    Authors: 
    Leonardo W Heyerdahl; Muriel Vray; Benedetta Lana; Nastassia Tvardik; Nina Gobat; Marta Wanat; Sarah Tonkin-Crine; Sibyl Anthierens; Herman Goossens; Tamara Giles-Vernick;
    Publisher: HAL CCSD
    Countries: Belgium, United Kingdom, France
    Project: EC | RECoVER (101003589)

    AbstractThe COVID-19 vaccine rollout in recent months offers a powerful preventive measure that may help control SARS-CoV-2 transmission. Nevertheless, long-standing public hesitation around vaccines has heightened public health concerns that vaccine coverage may not achieve desired public health impacts.This cross-sectional survey was conducted online in December 2020 among 7000 respondents (aged 18 to 65) in Belgium, France, Germany, Italy, Spain, Sweden, and Ukraine. The survey included open text boxes for fuller explanation of responses. Projected COVID-19 vaccine coverage varied and may not be sufficiently high among certain populations to achieve herd immunity. Overall, 56.9% would accept a COVID-19 vaccine, 19.0% would not, and 24.1% did not know or preferred not to say. By country, between 44% (France) and 66% (Italy) of respondents would accept a COVID-19 vaccine. Respondents expressed conditionality in open responses, voicing concerns about vaccine safety and mistrust of authorities. Public health campaigns must tackle these safety concerns.HighlightsMixed-method survey studied expected COVID vaccine uptake in 7 European countries.Projected COVID vaccine acceptance by country ranged from 44% to 66%.Explicit COVID vaccine acceptance or rejection was conditional.Study finds concerns about vaccine safety and authorities’ competence and honesty.Vaccine communications should address safety anxieties and target specific groups.

  • English
    Authors: 
    Shirish, Anuragini; O'Shanahan, John; Kumar, Anaya;
    Publisher: HAL CCSD
    Country: France

    Prix du meilleur second choix dans la catégorie recherche lors de la conférence UIIN.; International audience; To leverage the emerging potential of new technologies, digital transformation has been a clear priority for most large- and mid-sized organizations for over a decade now (Vial, 2019). However, COVID-19 pandemic has recently pushed several microbusinesses (MBs) to hurriedly initiate digital transformation (DT) efforts and keep their businesses afloat (Mandviwalla & Flanagan, 2021). MBs comprise a class of small and medium enterprise category (SMEs) that typically have fewer than 10 employees and lesser resources (OECD, 2021). They represent about 93 percent of all businesses in the Europe (European Commission, 2019). Their economic significance is also shown through ha survey which predicted that by 2024 small businesses through their DT efforts have the potential to add over 2.3 trillion USD to the global GDP, which would be key for the post pandemic economic recovery (CISCO, 2020). Prior research has shown that DT effectiveness varies significantly with firm size (Mandviwalla & Flanagan, 2021). Following these, the aim of our study is to examine to identify the enablers and inhibitors of digital transformation within the MB sector in Ireland.

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841 Research products, page 1 of 85
  • Open Access
    Authors: 
    Viktor K. Jirsa; Spase Petkoski; Huifang Wang; Michael Marmaduke Woodman; Jan Fousek; Cornelia Betsch; Lisa Felgendreff; Robert Böhm; Lau Lilleholt; Ingo Zettler; +3 more
    Publisher: Public Library of Science (PLoS)
    Country: France
    Project: EC | HBP SGA3 (945539)

    SummaryDuring the current COVID-19 pandemic, governments must make decisions based on a variety of information including estimations of infection spread, health care capacity, economic and psychosocial considerations. The disparate validity of current short-term forecasts of these factors is a major challenge to governments. By causally linking an established epidemiological spread model with dynamically evolving psychosocial variables, using Bayesian inference we estimate the strength and direction of these interactions for German and Danish data of disease spread, human mobility, and psychosocial factors based on the serial cross-sectional COVID-19 Snapshot Monitoring (COSMO;N= 16,981). We demonstrate that the strength of cumulative influence of psychosocial variables on infection rates is of a similar magnitude as the influence of physical distancing. We further show that the efficacy of political interventions to contain the disease strongly depends on societal diversity, in particular group-specific sensitivity to affective risk perception. As a consequence, the model may assist in quantifying the effect and timing of interventions, forecasting future scenarios, and differentiating the impact on diverse groups as a function of their societal organization. Importantly, the careful handling of societal factors, including support to the more vulnerable groups, adds another direct instrument to the battery of political interventions fighting epidemic spread.

  • Open Access English
    Authors: 
    Yuxin Song; Xuan-Nhi Nguyen; Anuj Kumar; Claire da Silva; Léa Picard; Lucie Etienne; Andrea Cimarelli;
    Publisher: HAL CCSD
    Country: France
    Project: ANR | ECOFECT (ANR-11-LABX-0048)

    ABSTRACTTo identify novel cellular modulators of HIV-1 infection in IFN-stimulated myeloid cells, we have carried out a screen that combines functional and evolutionary analyses in THP-1-PMA cells that led us to the Tripartite Motif Protein 69 (Trim69), a poorly studied member of the Trim family of innate immunity regulators. Trim69 inhibits HIV-1, primate lentiviruses and the negative and positive-strand RNA viruses VSV and SARS-CoV2, overall indicating it is a broad-spectrum antiviral factor. Trim69 binds directly to microtubules and its antiviral activity is intimately linked to its ability to promote the accumulation of stable MTs, a specialized subset of microtubules. By analyzing the behavior of primary blood cells, we provide evidence that a program of MT stabilization is commonly observed in response to IFN-I in cells of the myeloid lineage and Trim69 is the key factor behind this program.Overall, our study identifies Trim69 as the first antiviral innate defense factor that regulates the properties of microtubules to limit viral spread, highlighting the possibility that the cytoskeleton may be a novel unappreciated fighting ground in the host-pathogen interactions that underlie viral infections.

  • Open Access
    Authors: 
    Philippe Colson; Jérémy Delerce; Mamadou Beye; Anthony Levasseur; Céline Boschi; Linda Houhamdi; Hervé Tissot‐Dupont; Nouara Yahi; Matthieu Million; Bernard La Scola; +3 more
    Publisher: Wiley
    Country: France

    ABSTRACTThe SARS-CoV-2 21K/BA.1, 21L/BA.2, and BA.3 Omicron variants have recently emerged worldwide. To date, the 21L/BA.2 Omicron variant has remained very minority globally but became predominant in Denmark instead of the 21K/BA.1 variant. Here we describe the first cases diagnosed with this variant in south-eastern France. We identified thirteen cases using variant-specific qPCR and next-generation sequencing between 28/11/2021 and 31/01/2022, the first two cases being diagnosed in travellers returning from Tanzania. Overall, viral genomes displayed a mean (±standard deviation) number of 65.9±2.5 (range, 61-69) nucleotide substitutions and 31.0±8.3 (27-50) nucleotide deletions, resulting in 49.6±2.2 (45-52) amino acid substitutions (including 28 in the spike protein) and 12.4±1.1 (12-15) amino acid deletions. Phylogeny showed the distribution in three different clusters of these genomes, which were most closely related to genomes from England and South Africa, from Singapore and Nepal, or from France and Denmark. Structural predictions pointed out a significant enlargement and flattening of the 21L/BA.2 N-terminal domain surface compared with that of the 21K/BA.2 Omicron variant, which may facilitate initial viral interactions with lipid rafts. Close surveillance is needed at global, country and center scales to monitor the incidence and clinical outcome of the 21L/BA.2 Omicron variant.

  • Open Access
    Authors: 
    Ucheoma Nwaozuru; Chisom Obiezu-Umeh; Hassim Diallo; Danielle Graham; Guy-Lucien Whembolua; Marie Janeeca Bourgeau; Tiarney D. Ritchwood; LaRon E. Nelson; Thembekile Shato; Allison Mathews; +6 more
    Publisher: Research Square Platform LLC
    Country: France

    Abstract Background COVID-19 self-testing (ST) is an innovative strategy with the potential to increase the access and uptake of testing and ultimately to limit the spread of the virus. To maximize the uptake and reach of this promising strategy and inform intervention development and scale up, research is needed to understand the acceptability of and willingness to use this tool. This is vital to ensure that Black/African Americans are reached by the Biden-Harris Administration’s free national COVID-19 ST program. This study aimed to explore the acceptability and recommendations to promote and scale-up the uptake of COVID-19 ST among Black/African Americans. Methods We conducted a cross-sectional qualitative study using a semi-structured questionnaire to assess barriers and facilitators to the uptake of COVID-19 ST among a convenience sample of 28 self-identified Black/African Americans from schools, community centers, and faith-based institutions in Ohio and Maryland. Inductive content analysis was conducted to identify categories and subcategories related to acceptability and recommendations for implementing and scaling up COVID-19 ST in communities. Results Participants perceived COVID-19 self-testing as an acceptable tool that is beneficial to prevent transmission and address some of the barriers associated with health facility testing, such as transportation cost and human contact at the health facility. However, concerns were raised regarding the accurate use of the kits and costs. Recommendations for implementing and scaling up COVID-19 ST included engagement of community stakeholders to disseminate information about COVID-19 self-testing and creating culturally appropriate education tools to promote knowledge of and clear instructions about how to properly use COVID-19 ST kits. Based on these recommendations, the COVID-19 STEP (Self-Testing Education and Promotion) Project is being developed and will involve engaging community partners such as barbers, church leaders, and other community-based organizations to increase the uptake and use of free COVID-19 ST kits among Black/African Americans. Conclusion Findings showed that most participants considered COVID-19 ST valuable for encouraging COVID-19 testing. However, cost and accuracy concerns may pose barriers. Future work should consider implementing interventions that leverage the benefits of COVID-19 ST and further assess the extent to which these identified facilitators and barriers may influence COVID-19 ST uptake.

  • Open Access
    Authors: 
    Alban, Frederique; Sophie LEONARDI; Pascal, Le Floc H.;
    Country: France

    Les halles à marée, présentes sur tout le littoral métropolitain, sont les premiers marchés pour les produits de la mer débarqués par les flottilles de pêche. La question posée porte sur la capacité d’adaptation des halles à marée face aux fluctuations de l’offre et des cours du poisson provoquées par le premier confinement et amplifiées par le second en 2020. A l’échelle nationale, le chiffre d’affaires des premiers marchés a décliné de 18% par rapport à la moyenne des trois années précédentes. La méthode de décomposition du chiffre d’affaires démontre que la valeur des productions traduit une stratégie de quantité et plus rarement une action sur les prix. Des enquêtes auprès des responsables de halles à marée apportent une lecture complémentaire à celle des statistiques de vente, parfois même une lecture différente. La discussion des résultats soulève deux questions majeures. La première traite du biais informationnel quand on limite l’analyse à une approche quantitative des statistiques de production. La seconde pose la question de la menace potentielle des ventes directes sur les halles à marée. C’est l’occasion pour les responsables de criée de rappeler les garanties qu’ils offrent en termes de traçabilité des produits. The fish markets, which are present all along the coast of Metropolitan France, are the primary markets for the seafood products landed by the fishing fleets. The question raised concerns the capacity of the fish markets to adapt to the fluctuations in supply and fish prices caused by the first confinement and amplified by the second in 2020. On a domestic scale, the turnover of the first markets declined by 18% compared to the average of the previous three years. The method of breaking down turnover shows that the value of production reflects a strategy on quantity and more rarely a price policy. Surveys of fish market managers provide a complementary understanding to that of the sales statistics, sometimes even a different reading. The discussion of the results raises two major questions. The first deals with the informational bias when the analysis is limited to a quantitative approach to production statistics. The second is the question of the potential threat of direct sales to fish markets. This is an opportunity for the executives of the fish market to claim the guarantees they offer in terms of goods traceability.

  • Open Access English
    Authors: 
    Emma Hubert; Thibaut Mastrolia; Dylan Possamaï; Xavier Warin;
    Publisher: HAL CCSD
    Countries: United States, France
    Project: ANR | PACMAN (ANR-16-CE05-0027)

    In this work, we provide a general mathematical formalism to study the optimal control of an epidemic, such as the COVID-19 pandemic, via incentives to lockdown and testing. In particular, we model the interplay between the government and the population as a principal-agent problem with moral hazard, à la Cvitanić et al. (Finance Stoch 22(1):1-37, 2018), while an epidemic is spreading according to dynamics given by compartmental stochastic SIS or SIR models, as proposed respectively by Gray et al. (SIAM J Appl Math 71(3):876-902, 2011) and Tornatore et al. (Phys A Stat Mech Appl 354(15):111-126, 2005). More precisely, to limit the spread of a virus, the population can decrease the transmission rate of the disease by reducing interactions between individuals. However, this effort-which cannot be perfectly monitored by the government-comes at social and monetary cost for the population. To mitigate this cost, and thus encourage the lockdown of the population, the government can put in place an incentive policy, in the form of a tax or subsidy. In addition, the government may also implement a testing policy in order to know more precisely the spread of the epidemic within the country, and to isolate infected individuals. In terms of technical results, we demonstrate the optimal form of the tax, indexed on the proportion of infected individuals, as well as the optimal effort of the population, namely the transmission rate chosen in response to this tax. The government's optimisation problems then boils down to solving an Hamilton-Jacobi-Bellman equation. Numerical results confirm that if a tax policy is implemented, the population is encouraged to significantly reduce its interactions. If the government also adjusts its testing policy, less effort is required on the population side, individuals can interact almost as usual, and the epidemic is largely contained by the targeted isolation of positively-tested individuals.

  • Open Access English
    Authors: 
    Alexis Descatha; Grace Sembajwe; Fabien Gilbert; Marc Fadel;
    Publisher: Multidisciplinary Digital Publishing Institute
    Country: France

    Background. We aimed to assess the validity of the Mat-O-Covid Job Exposure Matrix (JEM) on SARS-CoV2 using compensation data from the French National Health Insurance compensation system for occupational-related COVID-19. Methods. Deidentified compensation data for occupational COVID-19 in France were obtained between August 2020 and August 2021. The acceptance was considered as the reference. Mat-O-Covid is an expert based French JEM on workplace exposure to SARS-CoV2. Bivariate and multivariate models were used to study the association between the exposure assessed by Mat-O-Covid and the reference, as well as the Area Under Curves (AUC), sensitivity, specificity, predictive values, and likelihood ratios. Results. In the 1140 cases included, there was a close association between the Mat-O-Covid index and the reference (p<0.0001). The overall predictivity was good, with an AUC of 0.78 and an optimal threshold at 13 per thousand. Using Youden’s J statistic resulted in 0.67 sensitivity and 0.87 specificity. Both positive and negative likelihood ratios were significant: respectively 4.9 [2.4-6.4] and 0.4 [0.3-0.4]. Discussion. It was possible to assess Mat-O-Covid’s validity using data from the national compensation system for occupational COVID-19. Though further studies are needed, Mat-O-Covid exposure assessment appears to be accurate enough to be used in research.

  • Open Access English
    Authors: 
    Houcemeddine Othman; Houcemeddine Othman; Haifa Ben Messaoud; Oussema Khamessi; Hazem Ben-Mabrouk; Kais Ghedira; Avani Bharuthram; Florette Treurnicht; Ikechukwu Achilonu; Yasien Sayed; +1 more
    Publisher: HAL CCSD
    Country: France
    Project: EC | PHINDaccess (811034)

    AbstractThe Receptor Binding Domain (RBD) of SARS-CoV-2 virus harbors a sequence of Arg-Gly-Asp tripeptide named RGD motif, which has also been identified in extracellular matrix proteins that bind integrins as well as other disintegrins and viruses. Accordingly, integrins have been proposed as host receptors for SARS-CoV-2. The hypothesis was supported by sequence and structural analysis. However, given that the microenvironment of the RGD motif imposes structural hindrance to the protein-protein association, the validity of this hypothesis is still uncertain. Here, we used normal mode analysis, accelerated molecular dynamics microscale simulation, and protein-protein docking to investigate the putative role of RGD motif of SARS-CoV-2 RBD for interacting with integrins. We found, by molecular dynamics, that neither RGD motif nore its microenvironment show any significant conformational shift in the RBD structure. Highly populated clusters were used to run a protein-protein docking against three RGD-binding integrin types, showing no capability of the RBD domain to interact with the RGD binding site. Moreover, the free energy landscape revealed that the RGD conformation within RBD could not acquire an optimal geometry to allow the interaction with integrins. Our results highlighted different structural features of the RGD motif that may prevent its involvement in the interaction with integrins. We, therefore, suggest, in the case where integrins are confirmed to be the direct host receptors for SARS-CoV-2, a possible involvement of other residues to stabilize the interaction.

  • Open Access English
    Authors: 
    Leonardo W Heyerdahl; Muriel Vray; Benedetta Lana; Nastassia Tvardik; Nina Gobat; Marta Wanat; Sarah Tonkin-Crine; Sibyl Anthierens; Herman Goossens; Tamara Giles-Vernick;
    Publisher: HAL CCSD
    Countries: Belgium, United Kingdom, France
    Project: EC | RECoVER (101003589)

    AbstractThe COVID-19 vaccine rollout in recent months offers a powerful preventive measure that may help control SARS-CoV-2 transmission. Nevertheless, long-standing public hesitation around vaccines has heightened public health concerns that vaccine coverage may not achieve desired public health impacts.This cross-sectional survey was conducted online in December 2020 among 7000 respondents (aged 18 to 65) in Belgium, France, Germany, Italy, Spain, Sweden, and Ukraine. The survey included open text boxes for fuller explanation of responses. Projected COVID-19 vaccine coverage varied and may not be sufficiently high among certain populations to achieve herd immunity. Overall, 56.9% would accept a COVID-19 vaccine, 19.0% would not, and 24.1% did not know or preferred not to say. By country, between 44% (France) and 66% (Italy) of respondents would accept a COVID-19 vaccine. Respondents expressed conditionality in open responses, voicing concerns about vaccine safety and mistrust of authorities. Public health campaigns must tackle these safety concerns.HighlightsMixed-method survey studied expected COVID vaccine uptake in 7 European countries.Projected COVID vaccine acceptance by country ranged from 44% to 66%.Explicit COVID vaccine acceptance or rejection was conditional.Study finds concerns about vaccine safety and authorities’ competence and honesty.Vaccine communications should address safety anxieties and target specific groups.

  • English
    Authors: 
    Shirish, Anuragini; O'Shanahan, John; Kumar, Anaya;
    Publisher: HAL CCSD
    Country: France

    Prix du meilleur second choix dans la catégorie recherche lors de la conférence UIIN.; International audience; To leverage the emerging potential of new technologies, digital transformation has been a clear priority for most large- and mid-sized organizations for over a decade now (Vial, 2019). However, COVID-19 pandemic has recently pushed several microbusinesses (MBs) to hurriedly initiate digital transformation (DT) efforts and keep their businesses afloat (Mandviwalla & Flanagan, 2021). MBs comprise a class of small and medium enterprise category (SMEs) that typically have fewer than 10 employees and lesser resources (OECD, 2021). They represent about 93 percent of all businesses in the Europe (European Commission, 2019). Their economic significance is also shown through ha survey which predicted that by 2024 small businesses through their DT efforts have the potential to add over 2.3 trillion USD to the global GDP, which would be key for the post pandemic economic recovery (CISCO, 2020). Prior research has shown that DT effectiveness varies significantly with firm size (Mandviwalla & Flanagan, 2021). Following these, the aim of our study is to examine to identify the enablers and inhibitors of digital transformation within the MB sector in Ireland.

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