Sciences, Philosophie, Humanités

Experimentation and interpretation of cathodoluminescence (CL) microscopy and spectroscopy applied to the microcharacterization of material minerals are reviewed. The origins of the intrinsic (host lattice) and extrinsic (impurities) luminescence emissions in crystals are briefly discussed. Merits and limitations of the available techniques are illustrated. CL emission changes as a function of the incident electron dose are illustrated for the case of natural quartz and sphalerite (ZnS) crystals. These effects are discussed in terms of the development of bulk charging, production of heat, diffusion of impurities, and creation of lattice defects induced by the incident ionizing particles. Although CL emission is mostly extrinsic in origin there is no general rule for identifying the nature of impurities from the CL emission spectra of minerals. However there is potential for using CL spectroscopy for trace element analysis as presented for the case of minerals containing rare-earth luminescent ions. The CL emission is a signature of the crystal-chemistry properties of minerals and hence contains potential genetic information. Some of the applications of CL emissions in the geosciences are summarized.

We propose a toolkit for creating Tangible Out-of-Body Experiences: exposing the inner states of users using physiological signals such as heart rate or brain activity. Tobe can take the form of a tangible avatar displaying live physiological readings to reflect on ourselves and others. Such a toolkit could be used by researchers and designers to create a multitude of potential tangible applications, including (but not limited to) educational tools about Science Technologies Engineering and Mathematics (STEM) and cognitive science, medical applications or entertainment and social experiences with one or several users or Tobes involved. Through a co-design approach, we investigated how everyday people picture their physiology and we validated the acceptability of Tobe in a scientific museum. We also give a practical example where two users relax together, with insights on how Tobe helped them to synchronize their signals and share a moment.

Abstract In this paper, I present a general theory of topological explanations, and illustrate its fruitfulness by showing how it accounts for explanatory asymmetry. My argument is developed in three steps. In the first step, I show what it is for some topological property A to explain some physical or dynamical property B. Based on that, I derive three key criteria of successful topological explanations: a criterion concerning the facticity of topological explanations, i.e. what makes it true of a particular system; a criterion for describing counterfactual dependencies in two explanatory modes, i.e. the vertical and the horizontal and, finally, a third perspectival one that tells us when to use the vertical and when to use the horizontal mode. In the second step, I show how this general theory of topological explanations accounts for explanatory asymmetry in both the vertical and horizontal explanatory modes. Finally, in the third step, I argue that this theory is universally applicable across biological sciences, which helps in unifying essential concepts of biological networks. This article is part of the theme issue ‘Unifying the essential concepts of biological networks: biological insights and philosophical foundations'.

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This paper proposes an advanced statistical analysis method for results obtained by Laser-Induced Breakdown Spectroscopy on obsidian source samples from the Western Mediterranean area.

Cet article propose de considérer la notion de lieu de corpus comme une alternative numérique à celle de corpus. Le lieu de corpus est un espace numérique délimité dont les données possèdent trois caractéristiques incompatibles avec la notion de corpus : l’instabilité, la mixité et l’incomplétude. La définition de cette notion s’appuiera sur la description du compte Facebook « Ma Thèse Sdl », lieu de corpus constitué dans l’objectif d’observer le discours produit sur les réseaux sociaux numériques. Elle sera complétée par la proposition d’une méthodologie de représentation du lieu de corpus : la représentation arborescente. Enfin, les nouvelles perspectives d’interactivité ouvertes par cette notion permettront d’interroger la place des acteurs le constituant et la posture du chercheur.

This study presents test measurements on a Lexsyg luminescence reader, acquired by the Giessen luminescence group. The reader is of the type Standard, hence designed for routine determination of palaeodoses using quartz or K-feldspars. The tests include measurements of the stimulation powers, preheat temperatures, OSL- and TL-curves, as well as dose recovery tests and calibration measurements using highly sensitised calibration quartz. A comparison of D e values determined using a Lexsyg reader with single grain D e-values, which have been previously obtained on a Risø reader, is also presented. The results imply that the Lexsyg reader is a highly reliable measurement device with high reproducibility, yielding instrumental uncertainties of around 0.3%.

Abstract In 2013, in a Paris library, I found a long and interesting letter from Edith Wharton to Minnie Bourget. Among other things, Wharton discusses her reading—including Henry James's latest (but unnamed) novel—and her own writing. In this article I explain why I think the letter was written in 1896, and what new questions the date opens up.

Photonic technologies are often advertised as capable of revolutionizing our lives in the near future. However, the exact meaning of the word “photonics” as well as the scope of the field remain unclear. The term was born in the 1970s in both France and the Netherlands where various scholarly communities began research into the phenomenon. Some resulting technologies started circulating in industry and academia and the concept of photonics became very successful in the late 1980s when photons were supposed to replace electrons in every-day technologies. The failure of optical computing damaged the reputation of photonics in the 1990s but the term lived on as it merged with sister terms such as electro-optics and optoelectronics. The key problem with photonics is the breadth of its scope. Some argue it is the science of light, others consider it an economic category. Generally, photonics covers lasers, optical fibers as well as solar energy and LEDs. It seems that the only conceptual tool capable of addressing this complexity is that of technological paradigms, which Ernest Sternberg applied to photonics in 1992. Sternberg's approach can help to clarify the epistemological boundaries of the name “photonics,” even when addressing this complex area from a 21st century stand point.

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In the last couple of years a few seemingly independent debates on scientific explanation have emerged, with several key questions that take different forms in different areas. For example, the questions what makes an explanation distinctly mathematical and are there any non-causal explanations in sciences (i.e., explanations that don’t cite causes in the explanans) sometimes take a form of the question what makes mathematical models explanatory, especially whether highly idealized models in science can be explanatory and in virtue of what they are explanatory. These questions raise further issues about counterfactuals, modality, and explanatory asymmetries: i.e., do mathematical and non-causal explanations support counterfactuals, and how ought we to understand explanatory asymmetries in non-causal explanations? Even though these are very common issues in the philosophy of physics and mathematics, they can be found in different guises in the philosophy of biology where there is the statistical interpretation of the Modern Synthesis theory of evolution, according to which the post-Darwinian theory of natural selection explains evolutionary change by citing statistical properties of populations and not the causes of changes. These questions also arise in philosophy of ecology or neuroscience in regard to the nature of topological explanations. The question here is can the mathematical (or more precisely topological) properties in network models in biology, ecology, neuroscience, and computer science be explanatory of physical phenomena, or are they just different ways to represent causal structures.The aim of this special issue is to unify all these debates around several overlapping questions. These questions are: are there genuinely or distinctively mathematical and non-causal explanations?; are all distinctively mathematical explanations also non-causal; in virtue of what they are explanatory; does the instantiation, implementation, or in general, applicability of mathematical structures to a variety of phenomena and systems play any explanatory role? What makes them universally applicable: is it the genericity with generic and rudimentary features of particular types of mathematical explanations (such as topological) that makes them universally applicable, or is it because they explain by providing understanding of mathematical structure independently from being instantiated in any particular system? Or if they can be explanatory only when the details of instantiation are provided, is it then some ontological fact that makes them universally applicable to a variety of very diverse phenomena, e.g., is there some fundamental physical fact in virtue of which many real-world systems exhibit or instantiate certain topologies?This special issue provides a platform for unifying the debates around several key issues and thus opens up avenues for better understanding of mathematical and non-causal explanations in general, but also, it will enable even better understanding of key issues within each of the debates. The topic of mathematical and non-causal explanations is increasingly being discussed in the last couple of years (Bokulich 2008; Saatsi and Pexton 2013; Batterman and Rice 2014; Huneman [2010] 2015; Kostic 2016a, b; Lange [2013] 2016; Saatsi and Jansson 2016; Chirimuuta 2018). A growing literature on mathematical and non-causal explanations enquires into the general features of these explanations and their relation to some of the well understood accounts of causal explanation, such as the mechanistic account (Machamer et al. 2000; Craver 2007; Craver and Darden 2013), the deductive-nomological account (Hempel and Oppenheim 1948), or semantic account (Chalmers and Jackson 2001).However, not enough attention is devoted to the specific accounts of non-causal and mathematical explanations in their own right, without a comparative point of view of causal explanations. Even more importantly, the lack of discussions about the epistemic norms that specific scientific problems or areas of science impose on the structure of explanation has become increasingly apparent.The contributions in this special issue respond to these challenges in a very systematic and direct way. Bob Batterman argues that the notion of universality has been misunderstood in the recent philosophical literature. He argues that to explain how a phenomenon is universal requires recognizing that universality implies a kind of stability of behavior under perturbation. Furthermore, he argues that this stability itself requires explanation. He discusses how the renormalization group can provide the relevant explanation. The explanation of the stability characteristic of universality is then related to the autonomy of certain models or theories at continuum scales from those at scales of molecules or atoms.Marc Lange discusses the basis on which an explanation of a given phenomenon can be deemed causal or non-causal. When we use one rather than the other type of explanation to explain a phenomenon, we immediately face the question of whether the one we decided not to use is less explanatory, whether the two explain the same facts, and to what extent they are competitors or complementary. Lange discuses two explanations of rocket acceleration, one (which uses forces) that he deems causal-mechanical and the other (which uses conservation laws) that he deems non-causal. Lange argues that the causal explanation explains facts that the conservation-law explanation can’t, but also that the conservation-law explanation explains facts that the causal explanation can’t. Thus, they are not competitors. Furthermore, the conservation-law explanation has some virtues that the causal one lacks. For instance, the conservation-law explanation unifies various different propulsion mechanisms and that it would still have held even if the rocket’s propulsion mechanisms had been replaced. Moreover, it would still have held even if some of the laws governing molecular collisions had been radically different and even if the causal explanation had been different.Daniel Kostic argues that there are various trade-offs among the complexity in the structure of explanation, scientific understanding, and explanatory depth. The idea is that the level of complexity in the structure of explanation is inversely proportional to the level of intimacy between explanation and understanding, i.e., the more complexity the less intimacy. This further affects the explanatory depth, i.e., the less complexity the greater explanatory depth and vice versa. His account provides a framework for making sense of various levels of intimacy between the explanation and understanding; from the ones in which explanation and understanding are the most distinct, i.e., where there can’t be understanding without explanation (Strevens [2008] 2013; Khalifa [2012] 2017) to cases where the explanation has a minimal structure and it seems that scientific understanding is obtained without explanation (Lipton 2009). This is a gradual view of explanation, according to which the less structure it has the more understanding it provides, and vice versa. Thus, he concludes that the topological explanations and some other types of non-causal explanations indeed have a minimal structure by virtue of which they provide greater understanding and explanatory depth.In his contribution Hugh Desmond argues that it is puzzling why re-describing a phenomenon with different levels of detail should make a difference between whether causal or non-causal explanations are favored. Desmond argues that this particular situation creates a serious problem for the ontic approach to causal and non-causal explanations, and instead he proposes a pragmatic-modal account, which accounts for the relation between granularity and the causal nature of explanation in terms of how contextual factors affect the modal structure of an explanation. Desmond’s account has the additional advantage of dissolving some important disagreements concerning the status of non-causal explanation issues.In his contribution Luca Rivelli revisits Stuart Kaufman’s idea about ensemble explanations. Luca argues that in complex systems and evolutionary theory there is a hierarchy of non-mechanistic, non-causal explanations that form an explanatory chain in the hierarchy of levels of explanations, where explanantia at the higher level are recursively explained at the lower level. Such a hierarchical ensemble as a whole is grounded in some kind of a mechanistic explanation. The ensemble account of explanation has two very important features, it provides a framework for understanding the multilevel mechanistic explanations of certain aspects of weak emergence and it also provides a framework for thinking about the explanatory unification of non-causal explanations.Finally, Philippe Huneman argues that the post-genomic turn in evolutionary biology does lead to a greater diversity of explanations, including some of the recently introduced cases of non-causal and mathematical explanations, such as topological explanations and statistical explanations. Huneman argues that the shift in understanding the concepts of genes, variation, and inheritance in postgenomic science provides topological and statistical explanatory frameworks that focus on genomic networks of many sorts and nucleotide-focused statistical tools respectively. These new explanatory practices are difficult to translate into mechanistic frameworks of explanation. Thus, according to him, this situation indicates diversification of explanatory frameworks in postgenomic science and evolutionary biology, which should be a welcomed shift.The contributions in this special issue paint a clearer picture about the relation between mathematical and non-causal explanations. Not all mathematical explanations are equally non-causal, there are degrees of being non-causal which are reflected in the level of explanatoriness, unification, modal strength, and explanatory depth. For example, explanations of universality and minimal structure explanations seem to be further on the spectrum of being non-causal, and they seem to provide greater unification, whereas statistical explanations, pragmatic-modal explanations, and ensemble explanations work better when they are supplemented or combined with some kind of causal/mechanical explanation. This further implies that the level of unification, modal strength, and explanatory depth are mutually dependent concepts which follow the degrees of being non-causal, i.e., the more non-causal the explanation is, the more unification, modal strength, and explanatory depth it provides. The literature on mathematical and non-causal explanations continues to grow and diversify; that is why it requires an assessment from the unifying perspective. That is why this special issue aims at discussing the broad and converging set of ideas about mathematical and non-causal explanations that only recently started to emerge.

International audience

Color schemes ready for each type of data (qualitative, diverging or sequential), with colors that are distinct for all people, including color-blind readers. This package provides an implementation of Paul Tol (2018) and Fabio Crameri (2018) color schemes for use with 'graphics' or 'ggplot2'. It provides tools to simulate color-blindness and to test how well the colors of any palette are identifiable. Several scientific thematic schemes (geologic timescale, land cover, FAO soils, etc.) are also implemented.

ABSTRACT There are many ways to consider the philosophy of history. In this article, I claim that one of the most viable approaches to the philosophy of history today is that of critical theory of history, inspired by Reinhart Koselleck. Critical theory of history is based on what I call known history, history as it has been established and expounded by historians. What it contributes—its added value, so to speak—is a reflection on the categories employed to think about historical experience at its different levels, not only as a narrative but also as a series of events: their origins, contexts, terminology, functions (theoretical or practical), and, finally, eventual relevance.

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In the wake of the discovery of numerous large blade workshops at Le Grand-Pressigny site (Indre-et-Loire, France), which initially aroused great interest, the mid-Loire Valley region became central to studies of flint diffusion. Despite the quality of the initial work, the widely shared view now is that the capacity for this concept to continue to provide useful archaeological modelling has diminished. Establishing real and actual correlations between archaeological objects and geological samples remains difficult, making it almost impossible to determine the source of certain materials represented in an archaeological series. In response to this problem, the French collective research project "Réseau de lithothèque en région Centre-Val de Loire" assembled about 30 amateur and professional researchers from various European institutions to work on three strategic missions: Mission 1: establish a list of current lithotheques (“rock-libraries” or comparative collections), verify their contents and complete them if necessary; Mission 2: link the major types of depositional environments with the properties acquired by flint through its life; Mission 3: spread knowledge and information both within the project and to all interested persons. The project is closely associated with similar French programs already in place in Auvergne-Rhône-Alpes and Aquitaine regions. The ultimate objective is to build a national and international community around a common project, bringing participants together regularly to share knowledge and technical expertise.

Abstract News about the terrorist attack that shook Istanbul on 1 January 2017 spread like wildfire on old, new, and social media. HuffPost was quick to cover this developing story in all of its eighteen international editions. This chapter explores the professional routines and the journalistic rhetoric of three major editions of HuffPost – U.S., French, and Arabic – to evaluate the similarities and differences in their respective narratives about Islamist terrorism. It relies on semi-directed interviews and comparative content analysis of a trilingual corpus of forty full articles related to the Istanbul attack, to examine synergies and assess how each edition, depending on its social grounding, frames terrorism. Despite their shared brand affiliation, their conceptualization of terrorism is not unified. Not only do their editorial agendas differ, but so do their sources, their work routines, and the precautionary measures they take when disclosing sensitive or unverifiable information.

International audience

Cet article présente une étude des différentes transformations diagénétiques et de leur chronologie relative intervenues en milieu météorique et affectant le calcaire de la plate-forme carbonatée Oligocène supérieur au Nord du Bassin aquitain (France), en combinant des données de cathodoluminescence (imagerie et spectroscopie haute résolution) et de microsonde de Castaing. Plus de 128 analyses ponctuelles par la microsonde électronique (WDS) et plus de 60 analyses par cathodoluminescence (CL) ont été effectuées sur les différents ciments carbonatés identifiés préalablement par les méthodes classiques de microscopie optique. En fonction de l'intensité relative des bandes CL observées (350, 380, 430, 500 et 620 nm), il a été possible de classer les ciments en trois types. Grâce à ces investigations au sein de chaque ciment météorique, ce sont des successions de phases de croissance cristalline et de dissolution que l'on a pu identifier finement, et ainsi de proposer une séquence diagénétique météorique beaucoup plus réaliste exprimant les passages cycliques de la zone vadose (non saturée) à la zone météorique d'eau douce (saturée).

Nous partons de nos travaux autour des sites web organisationnels, dans une perspective stratégique, pour aller vers la notion d’identités numériques organisationnelles. La problématique de l’identité numérique mobilise de multiples logiques, données, acteurs, dispositifs et représentations. Si elle est souvent abordée sur le plan individuel, la modélisation proposée ici s’appuie sur un « soi » organisationnel, à partir duquel s’articulent trois plans : mise en scène de soi, mise en usages de soi et mise en évaluation de soi. Le recours à ce modèle, et à ses méthodologies associées, vise à montrer, dans une perspective systémique, la complexité des agencements numériques autour d’une organisation sur le web.