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Why should I comply with taxes if others don’t?: Social information and behavioral convergence: An experimental study
No full textInternational audienceThis experimental study investigates the impact of social information about others’ tax behavior on individuals’ subsequent tax decisions. Two types of social information are introduced: (i) the average income reported within the subject’s entire group, and (ii) the average income reported within a reference subgroup made of either peers or non-peers and chosen by the subject. Our results show that social information significantly affects subsequent tax decisions, with a change in reported income ranging from 15% to 30% of total income on average. Moreover, the influence of whole-group information on tax behavior appears to be stronger than that of chosen-group information. Quite strikingly, a majority of subjects show more interest in the tax behavior of non-peers than in that of peers. Finally, our data provide strong evidence of behavioral convergence towards the average tax behavior of others
Observation of emergent scaling of spin–charge correlations at the onset of the pseudogap
No full textInternational audienceIn strongly correlated materials, interacting electrons are entangled and form collective quantum states, resulting in rich low-temperature phase diagrams. Notable examples include cuprate superconductors, in which superconductivity emerges at low doping out of an unusual “pseudogap” metallic state above the critical temperature. The Fermi–Hubbard model, describing a wide range of phenomena associated with strong electron correlations, still offers major computational challenges despite its simple formulation. In this context, ultracold atoms quantum simulators have provided invaluable insights into the microscopic nature of correlated quantum states. Here, we use a quantum gas microscope Fermi–Hubbard simulator to explore a wide range of dopings and temperatures in a regime where a pseudogap is known to develop. By measuring multipoint correlation functions up to fifth order, we uncover a universal scaling behavior in magnetic and higher-order spin–charge correlations characterized by a doping-dependent temperature scale. Accurate comparisons with determinant Quantum Monte Carlo and Minimally Entangled Typical Thermal States simulations confirm that this temperature scale is comparable to the pseudogap temperature T ∗ . Our quantitative findings reveal a qualitative behavior of magnetic properties and spin–charge correlations in an emergent pseudogap and pave the way toward the exploration of charge pairing and collective phenomena expected at lower temperatures
Does Merging Small Bankruptcy Courts Increase Their Efficiency?
No full textWe estimate the impact of a 2009 reform that merged small bankruptcy courts on the qualityof their rulings. A conceptual framework enables us to link difference-in-difference estimatesto the impact of the reform on Type 1 errors (restructuring a non-viable firm) and Type 2errors (liquidating a viable firm). We apply this framework to an (almost) exhaustive sampleof 600,000 bankruptcy cases in France that started between 2000 and 2019. The reformunambiguously reduces Type 1 errors while having no impact on Type 2 errors. Post-mergercourt behavior is determined more by that of the absorbing court than by that of theabsorbed one
An angiosperm‐wide perspective on reproductive strategies and floral traits
No full textInternational audienceFlowering plants have many modes of sexual reproduction, notably varying from selfing to outcrossing, and from bisexual flowers to individuals with separate sexes (dioecy). These reproductive modes are associated with floral and life‐history traits that have evolved together, making it difficult to interpret correlations between traits. We analysed variation in 21 traits related to flowers, pollination, mating, sexual systems and life history from 361 species representative of flowering plant diversity. Outcrossing was mainly found among long‐lived, large‐stature plants, but hermaphroditic outcrossers and dioecious species appeared as largely nonoverlapping strategies in the trait space. Level of floral investment was the main difference between these strategies, with dioecious species having generally smaller, less rewarding flowers, a pattern that also occurred in biotically pollinated species. This multi‐trait study shows that pollination can be achieved in many, often contrasting, ways. Despite extensive variation in reproductive traits, dioecy stands out as being linked to floral traits primarily, while correlations with lifespan and dispersal traits appear spurious. We provide a conceptual framework based on lifespan, floral investment and sexual separation that can be used to integrate pollination, reproduction and plant growth in future research on plant evolution and ecology
The index of a pair of pure states and the interacting integer quantum Hall effect
No full textInternational audienceWe introduce the index of a pair of pure states on a unital C*-algebra, which is a generalization of the notion of the index of a pair of projections on a Hilbert space. We then show that the Hall conductance associated with an invertible state of a two-dimensional interacting electronic system which is symmetric under charge transformation may be written as the index , where is obtained from by inserting a unit of magnetic flux. This exhibits the integrality and continuity properties of the Hall conductance in the context of general topological features of
Les pouces des Néandertaliens de La Ferrassie : indices d’asymétrie et de spécialisation fonctionnelle
No full textInternational audienceLes premiers métacarpiens constituent des témoins privilégiés des comportements manuels, leur structure interne reflétant l’histoire mécanique des sollicitations auxquelles ils ont été soumis. Grâce à la plasticité du tissu osseux, ces éléments s’adaptent aux contraintes répétées au cours de la vie. L’étude de l’asymétrie bilatérale sur les premiers métacarpiens fournit ainsi des indices sur des préférences latérales et éclaire la nature des gestes techniques récurrents chez les hominines. Afin d’explorer cette question, nous avons examiné par micro-CT scans les premiers métacarpiens droits et gauches de La Ferrassie 1 et 2 (45-43 ka), comparés à un échantillon d’Homo sapiens actuels dont le profil biologique et les activités manuelles sont connus. Les analyses, menées avec le package MorphoMap sous R, permettent de caractériser finement la distribution et la rigidité de l’os cortical, en lien avec certains types d’activités manuelles.Les résultats révèlent un dimorphisme sexuel marqué : LF1 (mâle) présente une plus grande épaisseur corticale et une rigidité accrue par rapport à LF2 (femelle). De plus, une asymétrie directionnelle distincte est observée chez chaque individu : un net biais gaucher chez LF2, tandis que LF1 montre des indices compatibles avec une latéralisation droitière, bien que moins prononcés. Ces différences reflètent des sollicitations mécaniques distinctes : LF1 se rapproche des profils d’ouvriers spécialisés dans des tâches de précision, tandis que LF2 évoque un travail manuel plus intensif et répétitif.Ces observations suggèrent que les pouces des deux Néandertaliens de La Ferrassie semblent avoir été soumis à des sollicitations fonctionnelles différentes. L’étude ouvre ainsi de nouvelles perspectives sur l’articulation entre asymétrie bilatérale, contraintes fonctionnelles et comportements techniques chez les populations du Paléolithique
Appendix 1: Pönsé Khyungö Tsal and his identification with Rigdzin Gödem
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Integrating ethical, societal and environmental issues into algorithm design courses
No full textThis document, intended for computer science teachers, describes a case study that puts into practice a questioning of ethical, societal and environmental issues when designing or implementing a decision support system. This study is based on a very popular application, namely road navigation software that informs users of real-time traffic conditions and suggests routes between a starting point and a destination, taking these conditions into account (such as Waze). The approach proposes to intertwine technical considerations (optimal path algorithms, data needed for location, etc.) with a broader view of the ethical, environmental and societal issues raised by the tools studied. Based on the authors' experience conducting sessions with students over several years, this document discusses the context of such a study, suggests teaching resources for implementing it, describes ways to structure discussions, and shares scenarios in different teaching contexts
An ancient DNA perspective on the Russian conquest of Yakutia
No full textInternational audienceYakut communities from northeastern Siberia inhabit some of the coldest environments on Earth, preserving an extraordinary archaeological record. Their history was profoundly reshaped by the Russian conquest, which introduced cereals, pathogens and Christianity beginning in 1632 (refs. 1,2,3,4,5). However, the biological impact of these transformations remains unknown. Here we generated extensive ancient DNA data to elucidate contemporary changes in Yakut genomic diversity and oral microbiomes. We found Yakut origins tracing back to local populations that admixed with Trans-Baikal groups migrating as the Great Mongol Empire spread. Despite the Russian conquest, the Yakut gene pool and oral microbiomes appeared largely stable, although smallpox strains distinct from those documented in Europe by approximately 1650 circulated. Marital practices generally maintained low consanguinity, with the exception of one female bearing the latest markers of traditional shamanism, who was the daughter of second-degree relatives