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  • image/svg+xml art designer at PLoS, modified by Wikipedia users Nina, Beao, JakobVoss, and AnonMoos Open Access logo, converted into svg, designed by PLoS. This version with transparent background. http://commons.wikimedia.org/wiki/File:Open_Access_logo_PLoS_white.svg art designer at PLoS, modified by Wikipedia users Nina, Beao, JakobVoss, and AnonMoos http://www.plos.org/
    Authors: Avignon, Rémi;

    Cette thèse vise à approfondir la compréhension des relations commerciales entre fournisseurs et acheteurs au sein des chaînes de valeurs. Ce travail de recherche appliquée se concentre sur le secteur agroalimentaire, il mobilise à la fois des outils théoriques et empiriques. La thèse se découpe en trois chapitres présentés d’aval en amont de la chaîne de valeur.Le premier chapitre est un modèle théorique visant à analyser l’impact des centrales d’achat sur la variété des produits vendus par la grande distribution. L’écriture de ce chapitre est motivée par les deux vagues de créations de centrales d’achats en France de 2014 et 2018. Ces centrales sont mises en place par les distributeurs afin de négocier en commun leurs approvisionnements auprès de leurs fournisseurs. Les centrales créées en 2014 consistent en une coopération à l’achat, limitée aux marques de fournisseurs qui sont généralement offertes par des entreprises de grande taille. Les centrales créées en 2018 ont un champ d’application élargi aux produits de marques de distributeurs. Ceci questionne les autorités de régulation qui craignent un accroissement du déséquilibre des relations commerciales entre producteurs et distributeurs. Sous les hypothèses du modèle considéré dans ce chapitre, il peut être profitable pour des distributeurs de former une centrale consistant à s’engager à un référencement commun de produits même si cela conduit à une réduction du profit total de l’industrie. Le résultat le plus frappant est que la réduction du champ d’application des centrales ne protège pas les petits fournisseurs contre l'exclusion ou la baisse de leur de revenus. Par ailleurs, il n’est pas toujours profitable pour les distributeurs de chercher à étendre leur coopération sur l’ensemble des produits.Le deuxième chapitre est un modèle structurel qui vise à quantifier le pouvoir de marché des industriels producteurs de produits laitiers en France. Ce modèle permet de distinguer les deux origines du pouvoir de marché. En amont, le « markdown » est la capacité à acheter du lait cru en dessus du prix concurrentiel. En aval, le « markup » est la capacité à vendre des produits au-dessus du prix concurrentiel. L'analyse s'appuie sur une base de données exhaustive couvrant la période 2003-2018. Cette base contient les quantités et les prix des produits vendus et du lait cru par département d’origine. L’analyse est basée sur les coûts et exploite la relation technique entre le lait cru et les produits laitiers pour estimer les marges des fabricants. En utilisant l’existence de marchés concurrentiels, on distingue les deux sources de pouvoir de marché de chaque entreprise : le « markdown » estimé au niveau du département d’origine du lait et le « markup » estimé au niveau du produit. Les résultats indiquent que les entreprises laitières achètent le lait cru en moyenne avec un « markdown » de 15 % et vendent leur produit avec un « markup » de 45 %.Le troisième chapitre est une analyse empirique de la restructuration de la production laitière en France entre 1996 et 2019. Cette production a été libéralisée en Europe avec la fin des quotas laitiers qui avaient été instaurées en 1984. Ces quotas, qui visaient à éviter la surproduction de lait, ont été progressivement augmentés à partir de 2008 avant d’être complétement retirés en 2015. L'analyse s'appuie sur une base de données exhaustive fournissant la production (ou quota) de lait de chacune des fermes françaises entre 1996 et 2019. Entre 1996 et 2007, la dynamique de restructuration de la production laitière est homogène sur l’ensemble des territoires. A partir de 2008, suite à l’augmentation des droits à produire, la quantité totale produite a fortement augmenté. Les dynamiques sont devenues très hétérogènes entre les territoires, avec une concentration de la production dans les territoires les plus productifs. Ce chapitre documente l’hétérogénéité de l’impact de la fin des quotas entre les territoires et entreprises. This dissertation aims to understand commercial relationships between suppliers and buyers within value chains. This applied research focuses on the agri-food sector using theoretical and empirical tools. The three chapters analyze value chain relations from downstream to upstream.The first chapter is a theoretical model which analyzes the impact of purchasing alliances on the variety of products sold by supermarkets. The two waves of purchasing alliance creation in France in 2014 and 2018 have motivated the writing of this chapter. These purchasing alliances are set up by retailers to negotiate their supplies with their suppliers jointly. Alliances created in 2014 consist of purchasing cooperation limited to national brands generally offered by large companies. Alliances created in 2018 have an extended scope; they include private label products generally offered by small firms. This questions the regulatory authorities, who fear an increase of unbalanced commercial relations between producers and distributors. Under the model's assumptions, it may be profitable for retailers to commit to joint product listing decisions even if this reduces the industry profit. The most striking result is that reducing the scope of alliances does not protect small suppliers from being excluded or suffering profit losses. Moreover, it is not always profitable for retailers to expand their cooperation to all products.The second chapter is a structural model that aims to quantify the market power of firms processing dairy products in France. This model allows distinguishing the two origins of market power. Upstream, the "markdown" is the ability to buy raw milk above the competitive price. Downstream, the "markup" is the ability to sell products above the competitive price. The exhaustive database covers the period 2003-2018. It provides quantities and prices of products sold and raw milk by origin. The analysis is cost-based and exploits the technical relationship between raw milk and dairy products to estimate manufacturers' margins. The two sources of market power of each firm are distinguished thanks to the existence of a competitive product. The markdown is estimated at the firm-origin level and the markup at the firm-product level. Results indicate that dairy firms purchase raw milk on average with a markdown of 15% and sell their product with a markup of 45%.The third chapter is an empirical analysis of the restructuring of milk production in France between 1996 and 2019. Milk production has been liberalized in Europe with the end of the milk quotas introduced in 1984. Quotas, which aimed to avoid overproduction of milk in Europe, have been gradually increased from 2008 before being completely withdrawn in 2015. The database is exhaustive and provides each French dairy farm's production between 1996 and 2019. Between 1996 and 2007, the restructuring dynamics of milk production are homogeneous across all territories. From 2008, following the increase in production rights, the total quantity produced increased significantly. The dynamics became very heterogeneous between territories, with a concentration of production in the most productive territories. This chapter documents the heterogeneous impact of the end of quotas across territories and firms.

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  • Authors: Urso, Riccardo Giovanni; Vuitton, Veronique; Le Sergeant d’Hendecourt, L.; Flandinet, Laurene; +7 Authors

    International audience; Context. Near-and mid-infrared observations have revealed the presence of organic refractory materials in the solar system, in cometary nuclei and on the surface of centaurs, Kuiper-belt and trans-neptunian objects. In these astrophysical environments, organic materials can be formed because of the interaction of frozen volatile compounds with cosmic rays, stellar/solar particles, and favoured by thermal processing. The analysis of laboratory analogues of such materials gives information on their properties, complementary to observations. Aims. We present new experiments to contribute in the understanding of the chemical composition of organic refractory materials in space. Methods. We bombard frozen water, methanol and ammonia mixtures with 40 keV H + and we warm the by-products up to 300 K. The experiments allow the production of organic residues that we analyse by means of infrared spectroscopy and by Very High Resolution Mass Spectrometry to study their chemical composition and their high molecular diversity, including the presence of hexamethylenetetramine and its derivatives. Results. We find that the accumulated irradiation dose plays a role in determining the residue's composition. Conclusions. Based on the laboratory doses, we estimate the astrophysical timescales to be short enough to induce an efficient formation of organic refractory materials at the surface of icy bodies in the outer solar system.

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  • Authors: Bart, Sylvain; Amosse, Joel; Lowe, Christopher Nathan; Mougin, Christian; +2 Authors

    Ecotoxicological tests with earthworms are widely used and are mandatory for the risk assessment of pesticides prior to registration and commercial use. The current model species for standardized tests is Eisenia fetida or Eisenia andrei. However, these species are absent from agricultural soils and often less sensitive to pesticides than other earthworm species found in mineral soils. To move towards a better assessment of pesticide effects on non-target organisms, there is a need to perform a posteriori tests using relevant species. The endogeic species Aporrectodea caliginosa (Savigny, 1826) is representative of cultivated fields in temperate regions and is suggested as a relevant model test species. After providing information on its taxonomy, biology, and ecology, we reviewed current knowledge concerning its sensitivity towards pesticides. Moreover, we highlighted research gaps and promising perspectives. Finally, advice and recommendations are given for the establishment of laboratory cultures and experiments using this soil-dwelling earthworm species.

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  • Authors: Berger, Loïc; Berger, Nicolas; Bosetti, Valentina; Gilboa, Itzhak; +4 Authors

    Policymaking during a pandemic can be extremely challenging. As COVID-19 is a new disease and its global impacts are unprecedented, decisions need to be made in a highly uncertain, complex and rapidly changing environment. In such a context, in which human lives and the economy are at stake, we argue that using ideas and constructs from modern decision theory, even informally, will make policymaking more a responsible and transparent process.

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    Authors: Dawei, Liu; Wang, Zhenyu; Valérie, Nicolas; Martha, Lindner; +4 Authors

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  • Authors: Cho, Da-Jung; Han, Yo-Sub; Kim, Hwee; Salomaa, Kai;

    International audience; We introduce a new bio-inspired operation called a site-directed deletion motivated from site-directed mutagenesis performed by enzymatic activity of DNA polymerase: Given two strings x and y, a site-directed deletion partially deletes a substring of x guided by the string y that specifies which part of a substring can be deleted. We study a few decision problems with respect to the new operation and examine the closure properties of the (iterated) site-directed deletion operations. We, then, define a site-directed deletion-closed (and-free) language L and investigate its decidability properties when L is regular or context-free.

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  • Authors: Goasduff, A.; Ljungvall, J.; Rodríguez, T.R.; Bello Garrote, F.L.; +10 Authors

    International audience; Background: The neutron-deficient osmium isotopic chain provides a great laboratory for the study of shape evolution, with the transition from the soft triaxial rotor in Os168 to the well-deformed prolate rotor in Os180, while shape coexistence appears around N=96 in Os172. Therefore, the study of the Os isotopic chain should provide a better understanding of shape changes in nuclei and a detailed scrutiny of nuclear structure calculations. In this paper, the lifetimes of the low-lying yrast states of Os170 have been measured for the first time to investigate the shape evolution with neutron number. Purpose: Lifetimes of excited states in the ground-state band of Os170 are measured to investigate the shape evolution with neutron number in osmium isotopes and compare with state-of-the-art calculations. Methods: The states of interest were populated via the fusion-evaporation reaction Nd142(S32,4n) at a bombarding energy of 170 MeV at the ALTO facility from IPN (Orsay, France). Lifetimes of the 21+ and 41+ states in Os170 were measured with the recoil-distance Doppler-shift method using the Orsay universal plunger system. Results: Lifetimes of the two first excited states in Os170 were measured for the first time. A very small B(E2;41+→21+)/B(E2;21+→01+)=0.38(11) was found, which is very uncharacteristic for collective nuclei. These results were compared to state-of-the-art beyond-mean-field calculations. Conclusions: Although theoretical results give satisfactory results for the energy of the first few excited states in Os170 and the B(E2;21+→01+) they fail to reproduce the very small B(E2;41+→21+), which remains a puzzle.

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  • Authors: Rubino, S.; Leroux, H.; Aleon-Toppani, A.; Lantz, C.; +5 Authors

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  • Authors: Grouin, Cyril;

    Dans cet article, nous comparons l'impact de la simplification d'un schéma d'annotation sur un système de repérage d'entités nommées (REN). Une simplification consiste à rassembler les types d'entités nommées (EN) sous deux types génériques (personne et lieu), l'autre revient à mieux définir chaque type d'EN. Nous observons une amélioration des résultats sur les deux versions simplifiées. Nous étudions également la possibilité de retrouver le niveau de détail des types d'EN du schéma d'origine à partir des versions simplifiées. L'utilisation de règles de conversion permet de recouvrer les types d'EN d'origine, mais il reste une forme d'ambiguïté contextuelle qu'il est impossible de lever au moyen de règles. ABSTRACT Annotation scheme simplification : a one way trip with no return ? In this paper, we study the impact of annotation scheme simplification on named entity recognition (NER) performances. One simplification consists in merging all named entity (NE) types into two main types (person and location), while the other simplification relies on a better definition of all NE types. We achieved better results on the two simplified versions of the annotation scheme. We also study the ability to recover the original NE types from the simplified versions. The use of post-processing rules allows to recover a few original NE types. Nevertheless, we faced with a kind of contextual ambiguity which seems hard to process using rules.

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  • image/svg+xml art designer at PLoS, modified by Wikipedia users Nina, Beao, JakobVoss, and AnonMoos Open Access logo, converted into svg, designed by PLoS. This version with transparent background. http://commons.wikimedia.org/wiki/File:Open_Access_logo_PLoS_white.svg art designer at PLoS, modified by Wikipedia users Nina, Beao, JakobVoss, and AnonMoos http://www.plos.org/
    Authors: Honkanen, Pekka;

    Cette thèse se compose de trois articles. Les deux premiers articles étudient les flux d'informations sur les marchés financiers, et le troisième étudie comment les familles de fonds communs de placement peuvent utiliser des sources de revenus relativement discrétionnaires pour canaliser des bénéfices vers des fonds spécifiques au sein de la famille. Le premier article, rédigé en collaboration avec Daniel Schmidt, étudie les retombées de prix et de liquidité sur les marchés financiers. En utilisant une expérience quasi-naturelle, nous montrons que les investisseurs observent les prix des actions pour en extraire des signaux, et les utilisent pour effectuer des transactions. Dans le deuxième article, je montre que les fonds d'investissement acquièrent des informations par le marché des prêts de titres. Je montre que les fonds communs de placement actifs vendent les actions qui leur sont empruntées par des vendeurs à découvert, alors que les fonds indiciels - qui sont interdits de négociation - ne le font pas. D'un autre côté, les fonds indiciels sont en mesure de facturer des frais de prêt de titres plus élevés aux emprunteurs. Je leur attribue le fait qu'ils sont de meilleurs prêteurs dans le sens où ils ne peuvent pas utiliser les informations qu'ils obtiennent pour négocier, et donc tirer des bénéfices des informations des vendeurs à découvert. Le troisième article, également avec Daniel Schmidt, étudie les politiques des familles de fonds en matière de répartition des prêts de titres et des revenus de prêts entre les fonds membres. Nous montrons que les familles de fonds s'écartent de l'allocation équitable revendiquée, en dirigeant davantage de prêts de titres et de bénéfices de prêts vers les fonds indiciels. Cette conclusion est conforme à la substitution par les fonds des frais de gestion plus faibles par des revenus de prêts de titres plus élevés. This thesis consists of three articles. The two first articles study information flows in the financial markets, and the third one studies how mutual fund families may use relatively discretionary income sources to channel profits to specific funds within the family. The first article, joint with Daniel Schmidt, studies price and liquidity spillovers in financial markets. Using a quasi-natural experiment, we show that investors look at stock prices to extract signals, and use these to trade. In the second article, I show that mutual fund acquire information through the securities lending market. I show that active mutual funds start selling the stocks that are borrowed from them by short sellers, whereas index funds — that are prohibited from trading — do not. One the other hand, index funds are able to charge higher stock lending fees from the borrowers. I attribute this to them being better lenders in the sense that they can not use the information they gain to trade, and thereby extract profits from the short sellers’ information. The third article, also with Daniel Schmidt, studies fund family level policies in allocating securities loans and lending revenues between member funds. We show that fund families deviate from the claimed fair allocation, directing more securities loans and lending profits to index funds. The finding is in line with with funds substituting a lower expense ratio with higher securities lending income.

    image/svg+xml art designer at PLoS, modified by Wikipedia users Nina, Beao, JakobVoss, and AnonMoos Open Access logo, converted into svg, designed by PLoS. This version with transparent background. http://commons.wikimedia.org/wiki/File:Open_Access_logo_PLoS_white.svg art designer at PLoS, modified by Wikipedia users Nina, Beao, JakobVoss, and AnonMoos http://www.plos.org/ Hyper Article en Lig...arrow_drop_down
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  • image/svg+xml art designer at PLoS, modified by Wikipedia users Nina, Beao, JakobVoss, and AnonMoos Open Access logo, converted into svg, designed by PLoS. This version with transparent background. http://commons.wikimedia.org/wiki/File:Open_Access_logo_PLoS_white.svg art designer at PLoS, modified by Wikipedia users Nina, Beao, JakobVoss, and AnonMoos http://www.plos.org/
    Authors: Avignon, Rémi;

    Cette thèse vise à approfondir la compréhension des relations commerciales entre fournisseurs et acheteurs au sein des chaînes de valeurs. Ce travail de recherche appliquée se concentre sur le secteur agroalimentaire, il mobilise à la fois des outils théoriques et empiriques. La thèse se découpe en trois chapitres présentés d’aval en amont de la chaîne de valeur.Le premier chapitre est un modèle théorique visant à analyser l’impact des centrales d’achat sur la variété des produits vendus par la grande distribution. L’écriture de ce chapitre est motivée par les deux vagues de créations de centrales d’achats en France de 2014 et 2018. Ces centrales sont mises en place par les distributeurs afin de négocier en commun leurs approvisionnements auprès de leurs fournisseurs. Les centrales créées en 2014 consistent en une coopération à l’achat, limitée aux marques de fournisseurs qui sont généralement offertes par des entreprises de grande taille. Les centrales créées en 2018 ont un champ d’application élargi aux produits de marques de distributeurs. Ceci questionne les autorités de régulation qui craignent un accroissement du déséquilibre des relations commerciales entre producteurs et distributeurs. Sous les hypothèses du modèle considéré dans ce chapitre, il peut être profitable pour des distributeurs de former une centrale consistant à s’engager à un référencement commun de produits même si cela conduit à une réduction du profit total de l’industrie. Le résultat le plus frappant est que la réduction du champ d’application des centrales ne protège pas les petits fournisseurs contre l'exclusion ou la baisse de leur de revenus. Par ailleurs, il n’est pas toujours profitable pour les distributeurs de chercher à étendre leur coopération sur l’ensemble des produits.Le deuxième chapitre est un modèle structurel qui vise à quantifier le pouvoir de marché des industriels producteurs de produits laitiers en France. Ce modèle permet de distinguer les deux origines du pouvoir de marché. En amont, le « markdown » est la capacité à acheter du lait cru en dessus du prix concurrentiel. En aval, le « markup » est la capacité à vendre des produits au-dessus du prix concurrentiel. L'analyse s'appuie sur une base de données exhaustive couvrant la période 2003-2018. Cette base contient les quantités et les prix des produits vendus et du lait cru par département d’origine. L’analyse est basée sur les coûts et exploite la relation technique entre le lait cru et les produits laitiers pour estimer les marges des fabricants. En utilisant l’existence de marchés concurrentiels, on distingue les deux sources de pouvoir de marché de chaque entreprise : le « markdown » estimé au niveau du département d’origine du lait et le « markup » estimé au niveau du produit. Les résultats indiquent que les entreprises laitières achètent le lait cru en moyenne avec un « markdown » de 15 % et vendent leur produit avec un « markup » de 45 %.Le troisième chapitre est une analyse empirique de la restructuration de la production laitière en France entre 1996 et 2019. Cette production a été libéralisée en Europe avec la fin des quotas laitiers qui avaient été instaurées en 1984. Ces quotas, qui visaient à éviter la surproduction de lait, ont été progressivement augmentés à partir de 2008 avant d’être complétement retirés en 2015. L'analyse s'appuie sur une base de données exhaustive fournissant la production (ou quota) de lait de chacune des fermes françaises entre 1996 et 2019. Entre 1996 et 2007, la dynamique de restructuration de la production laitière est homogène sur l’ensemble des territoires. A partir de 2008, suite à l’augmentation des droits à produire, la quantité totale produite a fortement augmenté. Les dynamiques sont devenues très hétérogènes entre les territoires, avec une concentration de la production dans les territoires les plus productifs. Ce chapitre documente l’hétérogénéité de l’impact de la fin des quotas entre les territoires et entreprises. This dissertation aims to understand commercial relationships between suppliers and buyers within value chains. This applied research focuses on the agri-food sector using theoretical and empirical tools. The three chapters analyze value chain relations from downstream to upstream.The first chapter is a theoretical model which analyzes the impact of purchasing alliances on the variety of products sold by supermarkets. The two waves of purchasing alliance creation in France in 2014 and 2018 have motivated the writing of this chapter. These purchasing alliances are set up by retailers to negotiate their supplies with their suppliers jointly. Alliances created in 2014 consist of purchasing cooperation limited to national brands generally offered by large companies. Alliances created in 2018 have an extended scope; they include private label products generally offered by small firms. This questions the regulatory authorities, who fear an increase of unbalanced commercial relations between producers and distributors. Under the model's assumptions, it may be profitable for retailers to commit to joint product listing decisions even if this reduces the industry profit. The most striking result is that reducing the scope of alliances does not protect small suppliers from being excluded or suffering profit losses. Moreover, it is not always profitable for retailers to expand their cooperation to all products.The second chapter is a structural model that aims to quantify the market power of firms processing dairy products in France. This model allows distinguishing the two origins of market power. Upstream, the "markdown" is the ability to buy raw milk above the competitive price. Downstream, the "markup" is the ability to sell products above the competitive price. The exhaustive database covers the period 2003-2018. It provides quantities and prices of products sold and raw milk by origin. The analysis is cost-based and exploits the technical relationship between raw milk and dairy products to estimate manufacturers' margins. The two sources of market power of each firm are distinguished thanks to the existence of a competitive product. The markdown is estimated at the firm-origin level and the markup at the firm-product level. Results indicate that dairy firms purchase raw milk on average with a markdown of 15% and sell their product with a markup of 45%.The third chapter is an empirical analysis of the restructuring of milk production in France between 1996 and 2019. Milk production has been liberalized in Europe with the end of the milk quotas introduced in 1984. Quotas, which aimed to avoid overproduction of milk in Europe, have been gradually increased from 2008 before being completely withdrawn in 2015. The database is exhaustive and provides each French dairy farm's production between 1996 and 2019. Between 1996 and 2007, the restructuring dynamics of milk production are homogeneous across all territories. From 2008, following the increase in production rights, the total quantity produced increased significantly. The dynamics became very heterogeneous between territories, with a concentration of production in the most productive territories. This chapter documents the heterogeneous impact of the end of quotas across territories and firms.

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  • Authors: Urso, Riccardo Giovanni; Vuitton, Veronique; Le Sergeant d’Hendecourt, L.; Flandinet, Laurene; +7 Authors

    International audience; Context. Near-and mid-infrared observations have revealed the presence of organic refractory materials in the solar system, in cometary nuclei and on the surface of centaurs, Kuiper-belt and trans-neptunian objects. In these astrophysical environments, organic materials can be formed because of the interaction of frozen volatile compounds with cosmic rays, stellar/solar particles, and favoured by thermal processing. The analysis of laboratory analogues of such materials gives information on their properties, complementary to observations. Aims. We present new experiments to contribute in the understanding of the chemical composition of organic refractory materials in space. Methods. We bombard frozen water, methanol and ammonia mixtures with 40 keV H + and we warm the by-products up to 300 K. The experiments allow the production of organic residues that we analyse by means of infrared spectroscopy and by Very High Resolution Mass Spectrometry to study their chemical composition and their high molecular diversity, including the presence of hexamethylenetetramine and its derivatives. Results. We find that the accumulated irradiation dose plays a role in determining the residue's composition. Conclusions. Based on the laboratory doses, we estimate the astrophysical timescales to be short enough to induce an efficient formation of organic refractory materials at the surface of icy bodies in the outer solar system.

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  • Authors: Bart, Sylvain; Amosse, Joel; Lowe, Christopher Nathan; Mougin, Christian; +2 Authors

    Ecotoxicological tests with earthworms are widely used and are mandatory for the risk assessment of pesticides prior to registration and commercial use. The current model species for standardized tests is Eisenia fetida or Eisenia andrei. However, these species are absent from agricultural soils and often less sensitive to pesticides than other earthworm species found in mineral soils. To move towards a better assessment of pesticide effects on non-target organisms, there is a need to perform a posteriori tests using relevant species. The endogeic species Aporrectodea caliginosa (Savigny, 1826) is representative of cultivated fields in temperate regions and is suggested as a relevant model test species. After providing information on its taxonomy, biology, and ecology, we reviewed current knowledge concerning its sensitivity towards pesticides. Moreover, we highlighted research gaps and promising perspectives. Finally, advice and recommendations are given for the establishment of laboratory cultures and experiments using this soil-dwelling earthworm species.

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  • Authors: Berger, Loïc; Berger, Nicolas; Bosetti, Valentina; Gilboa, Itzhak; +4 Authors

    Policymaking during a pandemic can be extremely challenging. As COVID-19 is a new disease and its global impacts are unprecedented, decisions need to be made in a highly uncertain, complex and rapidly changing environment. In such a context, in which human lives and the economy are at stake, we argue that using ideas and constructs from modern decision theory, even informally, will make policymaking more a responsible and transparent process.

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    Authors: Dawei, Liu; Wang, Zhenyu; Valérie, Nicolas; Martha, Lindner; +4 Authors

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  • Authors: Cho, Da-Jung; Han, Yo-Sub; Kim, Hwee; Salomaa, Kai;

    International audience; We introduce a new bio-inspired operation called a site-directed deletion motivated from site-directed mutagenesis performed by enzymatic activity of DNA polymerase: Given two strings x and y, a site-directed deletion partially deletes a substring of x guided by the string y that specifies which part of a substring can be deleted. We study a few decision problems with respect to the new operation and examine the closure properties of the (iterated) site-directed deletion operations. We, then, define a site-directed deletion-closed (and-free) language L and investigate its decidability properties when L is regular or context-free.

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  • Authors: Goasduff, A.; Ljungvall, J.; Rodríguez, T.R.; Bello Garrote, F.L.; +10 Authors

    International audience; Background: The neutron-deficient osmium isotopic chain provides a great laboratory for the study of shape evolution, with the transition from the soft triaxial rotor in Os168 to the well-deformed prolate rotor in Os180, while shape coexistence appears around N=96 in Os172. Therefore, the study of the Os isotopic chain should provide a better understanding of shape changes in nuclei and a detailed scrutiny of nuclear structure calculations. In this paper, the lifetimes of the low-lying yrast states of Os170 have been measured for the first time to investigate the shape evolution with neutron number. Purpose: Lifetimes of excited states in the ground-state band of Os170 are measured to investigate the shape evolution with neutron number in osmium isotopes and compare with state-of-the-art calculations. Methods: The states of interest were populated via the fusion-evaporation reaction Nd142(S32,4n) at a bombarding energy of 170 MeV at the ALTO facility from IPN (Orsay, France). Lifetimes of the 21+ and 41+ states in Os170 were measured with the recoil-distance Doppler-shift method using the Orsay universal plunger system. Results: Lifetimes of the two first excited states in Os170 were measured for the first time. A very small B(E2;41+→21+)/B(E2;21+→01+)=0.38(11) was found, which is very uncharacteristic for collective nuclei. These results were compared to state-of-the-art beyond-mean-field calculations. Conclusions: Although theoretical results give satisfactory results for the energy of the first few excited states in Os170 and the B(E2;21+→01+) they fail to reproduce the very small B(E2;41+→21+), which remains a puzzle.

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  • Authors: Rubino, S.; Leroux, H.; Aleon-Toppani, A.; Lantz, C.; +5 Authors

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  • Authors: Grouin, Cyril;

    Dans cet article, nous comparons l'impact de la simplification d'un schéma d'annotation sur un système de repérage d'entités nommées (REN). Une simplification consiste à rassembler les types d'entités nommées (EN) sous deux types génériques (personne et lieu), l'autre revient à mieux définir chaque type d'EN. Nous observons une amélioration des résultats sur les deux versions simplifiées. Nous étudions également la possibilité de retrouver le niveau de détail des types d'EN du schéma d'origine à partir des versions simplifiées. L'utilisation de règles de conversion permet de recouvrer les types d'EN d'origine, mais il reste une forme d'ambiguïté contextuelle qu'il est impossible de lever au moyen de règles. ABSTRACT Annotation scheme simplification : a one way trip with no return ? In this paper, we study the impact of annotation scheme simplification on named entity recognition (NER) performances. One simplification consists in merging all named entity (NE) types into two main types (person and location), while the other simplification relies on a better definition of all NE types. We achieved better results on the two simplified versions of the annotation scheme. We also study the ability to recover the original NE types from the simplified versions. The use of post-processing rules allows to recover a few original NE types. Nevertheless, we faced with a kind of contextual ambiguity which seems hard to process using rules.

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