Malgré tous les signaux négatifs quant à son avenir, l’Europe a retrouvé des raisons d’espérer grâce au refus français de s’aligner sur les populismes. L’intégration politique de l’Europe dans un fédéralisme qui permet de décider à une majorité qualifiée, au lieu de s’enliser dans l’unanimité actuelle, est indispensable pour sortir de l’austérité budgétaire, faire converger les fiscalités, et trouver de nouvelles ressources à investir. La revendication d’un revenu décent par les Gilets jaunes sera satisfaite par la mise en place d’un (...) revenu universel à l’échelle de l’Europe. (shrink)

This article will explore the processes and concepts embedded within Dennis Doty’s fine arts studio practice, giving examples of how the work has developed from traditional paintings into its current interdisciplinary form. It examines why it is important to integrate traditional art-making skills with contemporary new media software and approaches. The article aims to illuminate some of the complex interdisciplinary processes that Doty employs to develop multiple bodies of work, including stereoscopic video paintings and projection-mapping artworks. His work explores ideas (...) of spatial perception and the changes that have been happening to our understanding of both physical and digital environments since the invention of the Internet. Doty’s processes demonstrate ways of finding connections between different mediums, analysing and unifying components in a way that can be helpful and inspiring for various professional fields. (shrink)

This article draws on insights of young people learning to make natural pigments and traditional paintings in acute climate vulnerable areas. Why do they paint during ongoing crises and how do they voice their future concerns? Critical realism is applied as a meta-theory in this field-based study in a slum area in Kolkata and the Sundarbans mangrove forest. Methods comprise focus groups, semi-structured interviews, and participant observation. Analysis was done in an abductive process, applying Roy Bhaskar’s model of ‘four-planar social (...) being’. The analysis demonstrates how painting with natural pigments leads the young ones towards: (a) discovering beauty in nature (b) transcendence of borders (c) transformation and responsible action (d) discovering one’s own dignity. Findings are discussed considering the key concepts co-presence and crisis system. I reflect upon how this local effort can inspire a new economy, with the signposts: becoming co-present with the natural world and the necessity of beauty. (shrink)

Caste : Groupe qui se distingue par ses privilèges et son esprit d’exclusive à l’égard de toute personne qui n’appartient pas au groupe. Larousse -/- La hausse des prix des carburants proposée pour lutter contre le changement climatique et mettre en œuvre les principes de la « transition écologique » adoptés par la France lors de la COP21, a fait naître le mouvement des gilets jaunes. Plus globalement c’est une bonne partie des français qui se trouve concernée, celle qui vit (...) dans des zones excentrées et qui ne bénéficie pas d'un réseau de transports très efficient tel celui qui émaille par exemple le territoire parisien. Ainsi, augmenter les prix des carburants, en particulier le diesel, a été perçu comme un contresens économique anti-populaire. Pendant des en, les producteurs d’automobiles, avec le support des politiques publiques, ont présenté le diesel comme le carburant le moins polluant. Mais aujourd’hui devenu le carburant « satanique », les consommateurs qui l’ont choisi, en toute bonne conscience, se sentent manipulés. La reconversion vers l’achat d’une voiture électrique est hors de la portée de la plupart de ceux qui aujourd’hui manifestent. Les aides du gouvernement ne changent pas cette réalité socioéconomique. Sous quel angle, les média ont-ils restitué le mouvement des gilets jaunes ? Alors qu’on voit émerger au sein de ce mouvement des revendications pour plus de justice sociale, qu’en est-il de la justice environnementale ? Peut-on dire qu’il s’agit d’une révolte sociale anti-écologique ? Ou autrement dit, les gilets jaunes sont-ils un mouvement anti-écologique ? (shrink)

Many pigmented heterokonts are able to synthesize elements of their cell walls (the frustules) of dense biogenic silica. These include diatom algae, which occupy a significant place in the biosphere. The siliceous frustules of diatoms have species‐specific patterns of surface structures between 10 and a few hundred nanometers. The present review considers possible mechanisms of uptake of silicic acid from the aquatic environment, its transport across the plasmalemma, and intracellular transport and deposition of silica inside the specialized Silica Deposition Vesicle (...) (SDV) where elements of the new frustule are formed. It is proposed that a complex of silicic acid with positively charged proteins silaffins and polypropylamines remains a homogeneous solution during the intracellular transport to SDV, where biogenic silica precipitates. The high density of the deposited biogenic silica may be due to removal of water from the SDV by aquaporins followed by syneresis—a process during which pore water is expelled from the network of the contracting gel. The pattern of aquaporins in the silicalemma, the membrane embracing the SDV, can determine the pattern of species‐specific siliceous nanostructures. BioEssays 30:328–337, 2008. © 2008 Wiley Periodicals, Inc. (shrink)

Au tournant du siècle, les syndicats américains tendent à présenter les immigrants chinois comme la principale menace contre les travailleurs syndiqués blancs. Par une analyse des discours sur le danger racial, la santé publique et les rôles sexués qui permettent la sécurité familiale, cet article examine la façon dont l'image de la menace sanitaire représentée par les Chinois a fini par être partie intégrante des campagnes en direction des consommateurs orchestrées par les syndicats américains.

Au tournant du siècle, les syndicats américains tendent à présenter les immigrants chinois comme la principale menace contre les travailleurs syndiqués blancs. Par une analyse des discours sur le danger racial, la santé publique et les rôles sexués qui permettent la sécurité familiale, cet article examine la façon dont l'image de la menace sanitaire représentée par les Chinois a fini par être partie intégrante des campagnes en direction des consommateurs orchestrées par les syndicats américains.

Il n'est pas habituel de considérer un philosophe comme un ogre. Mais que faire si l'on entend la voix d'un ogre dans la voix d'un philosophe? Et quel sens donner à ce phénomène oratoire saisissant quand on le perçoit non seulement dans la voix de Gilles Deleuze, mais aussi dans celles de Michel Foucault ou de Vladimir Jankélévitch? La philosophie se présente à son public comme forme raisonnante par excellence. Mais l'archivage sonore des séminaires de Gilles Deleuze nous oblige à (...) un tout autre portrait du philosophe et de l'activité philosophique elle-même. (shrink)

The retina pigment epithelium (RPE) is a highly specialised epithelium that serves as a multifunctional and indispensable component of the vertebrate eye. Although a great deal of attention has been paid to its transdifferentiation capabilities and its ancillary functions in neural retina development, little is known about the molecular mechanisms that specify the RPE itself. Recent advances in our understanding of the genetic network that controls the progressive specification of the eye anlage in vertebrates have provided some of the (...) initial cues to the mechanisms responsible for RPE patterning. Here, we have outlined many recent findings that suggest that a limited number of transcription factors, including Otx2, Mitf and Pax6 and a few signalling cascades, are the elements required for the onset of RPE specification in vertebrates. Furthermore, using this information and the data available on the specification of the pigmented cells of primitive chordates, we have ventured some hypotheses on the origin of RPE cells during evolution. BioEssays 26:766–777, 2004. © 2004 Wiley Periodicals, Inc. (shrink)

Darwin1 introduced the idea that ornamental secondary sexual traits have evolved in response to female preferences for showy males. Among such traits, yellow and red carotenoid‐based ornaments have been considered as particularly good candidates for explaining why and how females would benefit from mating with showy partners. Because carotenoids can be used for promotion of both health and appearance, colourful male ornaments should honestly reveal the vigour of the bearers. Two recent experiments with birds2,3 now show how allocation of bodily (...) carotenoids to sexual signalling is traded off against the use of carotenoids for boosting immune function. BioEssays 25:746–747, 2003. © 2003 Wiley Periodicals, Inc. (shrink)

Melanin, and other pigments have recently been shown to preserve over geologic time scales, and are found in several different organisms. This opens up the possibility of inferring colours and colour patterns ranging from invertebrates to feathered dinosaurs and mammals. An emerging discipline is palaeo colour: colour plays an important role in display and camouflage as well as in integumental strengthening and protection, which makes possible the hitherto difficult task of doing inferences about past ecologies, behaviours, and organismal appearance. Several (...) studies and techniques have been presented in the last couple of years that have described ways to characterize pigment patterns. Here, I will review the available methods and the likely applications to understand past ecologies. A golden age of colourized dinosaurs and other animals is now dawning upon us, which may elucidate the nature of ancient predator prey interactions and display structures.Also watch the Video Abstract. (shrink)

In this essay, the hypothesis that biliverdin pigment plays an antioxidant role in the avian eggshell is proposed. Due to its ability to scavenge free radical species and to reduce mutation, biliverdin potentially counteracts the oxidative action of pathogens that penetrate the eggshell and/or protects the shell membrane from oxidation, thus promoting the proven antioxidant and antimicrobial capacities of the shell membrane itself. Additionally, biliverdin may be able to inhibit viral replication in the eggshell due to its ascribed antiviral (...) properties. Moreover, previous results in other taxa leave open the question of whether biliverdin can be absorbed by the embryo from the eggshell and play a role in embryogenesis. These mechanisms of antioxidant action of eggshell biliverdin remain totally unexplored in birds and in other oviparous animals. The main assumptions and predictions of the antioxidant hypothesis are developed, and directions for future research are proposed. (shrink)

Pour saisir les enjeux de la lutte au quotidien des Gilets jaunes et la transformation des identifications qu’elle opère, nous proposons d’analyser la manière dont les temporalités de l’événement en jaune structurent la vie quotidienne des protagonistes et scandent les temporalités familiales comme celles liées au travail et au loisir. Nous suivrons les mutations profondes de leurs formes d’engagement, l’appropriation des pratiques militantes au fil des semaines de cette séquence de protestation, ainsi que les processus de désagrégation longs du (...) mouvement qui mèneront à la disparition de certaines _configurations sociales localisées_. L’article s’appuie sur une recherche localisée qui dure depuis le 17 novembre 2018. À partir d’une lecture « par le bas », nous resserrons particulièrement la focale sur les trajectoires militantes de quelques Gilets jaunes. Ces protagonistes présentent trois caractéristiques : une mobilisation qui s’inscrit dans la durée ; la centralité de certains d’en... (shrink)

Recently, we reported that melanoma risk in redheads is linked not only to pale skin, but also to the synthesis of the pigment – called pheomelanin – that gives red hair its color. We demonstrated that pheomelanin synthesis is associated with increased oxidative stress in the skin, yet we have not uncovered the chemical pathway between the molecule pheomelanin and the DNA damage that drives melanoma formation. Here, we hypothesize two possible pathways. On one hand, pheomelanin might generate reactive (...) oxygen species (ROS) that directly or indirectly cause oxidative DNA damage. On the other hand, pheomelanin synthesis might consume cellular antioxidant stores and make the cell nucleus more vulnerable to other endogenous ROS. Uncovering the mechanistic pathway between pheomelanin and oxidative DNA damage will be an important step in developing strategies to lower melanoma risk in redheads. (shrink)

How can a work of art give us clues about scientific aspects? How can chemistry help a painter enhance his creativity and, above all, preserve the original characteristics of his work? Does an artist require scientific knowledge to innovate or, at least, not to be faked? Other symbiotic fields between art and science are: tattoos, as body art with physical and chemical consequences; pigments, as basic materials with interesting historiographical preparations; spectroscopy diagnosis, as very broad and thorough method of analysis (...) ; biosensors, as one of the applications of new pigments. Note also the interconnection between the several possible paths of science and art, which reflect new challenges with enormous potential investigated through a literature review and the application as a case study in an educational inquiry module. (shrink)

The pigment melanin is found in all living kingdoms and in many different structures and forms. When its various functions are examined separately, its behaviors seem disparate and conflicting. It has a clear role in camouflage and sexual display. Other major roles are examined critically. It can act as a sun screen but is not a very effective one. It can also scavenge active chemical species, but this, too, is not done very effectively. It produces active radicals that can (...) damage DNA. It binds to drugs in ways that are either beneficial or deleterious. Aside from camouflage, its other roles can be brought together by a unifying hypothesis as first proposed by Proctor and McGinness nearly 20 years ago. Melanin is envisaged as an energy transducer with the properties of an amorphous semiconductor. It can absorb many different types of energy and dissipate them in the form of heat. However, if the energy input is too great, the output can be expressed in the form of activated chemical species that can damage cellular macromolecules resulting in cell death, mutations and cancer. The protective aspect of melanin in dark skin is seen as resulting from its high concentration and its confinement to ellipsoidal and densely packed organelles that can effectively shield the nucleus. In light skin, its radical nature is seen as potentially participating in the carcinogenic process, particularly when overwhelmed by intense episodes of sunburn. (shrink)

Variations in human skin pigmentation are obvious, but how have skin colour differences evolved? Although clearly a polymorphic trait, the number and identity of key variants has remained unclear. Investigation of pigmentation phenotypes in model organisms provides a route to identify these genes and showed MC1R to be one key locus. Now, cloning of a classic zebrafish mutant, golden, identifies slc24a5 as a gene involved in fish skin pigmentation.1 Strikingly this study identifies the human orthologue, SLC24A5, as likely to make (...) a major contribution to the pale skin colouration of Western Europeans. BioEssays 28: 578–582, 2006. © 2006 Wiley Periodicals, Inc. (shrink)

The discovery of traces of a blood meal in the abdomen of a 50‐million‐year‐old mosquito reminds us of the insights that the chemistry of fossils can provide. Ancient DNA is the best known fossil molecule. It is less well known that new fossil targets and a growing database of ancient gene sequences are paralleled by discoveries on other classes of organic molecules. New analytical tools, such as the synchrotron, reveal traces of the original composition of arthropod cuticles that are more (...) than 400 my old. Pigments such as melanin are readily fossilized, surviving virtually unaltered for ∼200 my. Other biomarkers provide evidence of microbial processes in ancient sediments, and have been used to reveal the presence of demosponges, for example, more than 635 mya, long before their spicules appear in the fossil record. Ancient biomolecules are a powerful complement to fossil remains in revealing the history of life. (shrink)

Are colors relational or non-relational properties of their bearers? Is red a property that is instantiated by all and only the objects with a certain intrinsic (/non-relational) nature? Or does an object with a particular intrinsic (/non-relational) nature count as red only in virtue of standing in certain relations - for example, only when it looks a certain way to a certain perceiver, or only in certain circumstances of observation? In this paper I shall argue for the view that color (...) properties are relational (henceforth, relationalism), and against the view that colors are not relational (henceforth, anti- or non-relationalism). (shrink)

This chapter discusses color blindness and how it can be considered a guide and test for theories of normal vision. There are a multitude of stories to be told about the physiology of the receptor pigments of the eye and the genes that code for them, about the various kinds of cells in the retina and elsewhere in the visual system, and about color processing in the brain. It is a topic on which psychologists, physicists, biologists, and neurophysiologists have reason (...) to be proud and glad of the convergence of interests and views. Color blindness might, at first, seem just a peripheral abnormality, but it has often been both a guide to the nature of normal color vision and a test application for theories of it. It has the potential to provide cases where the various components of a complex process that are either hard or impossible to separate artificially are found already separated in nature. (shrink)