1,009 research outputs found
Climatic interpretation of high-resolution chemistry and dust data from East Antarctica
No full textClimate change has become real. Extreme weather events like floods, draughts and hurricanes have gripped peoples and the media’s attention and have been put in relation with rising greenhouse gas concentrations and deforestation. Desertification and extinction of species are now monitored and alternative energy production has become a profitablemarket. These signs show that people all over the world have accepted climate changeas a reality and are prepared to adapt. The question of how to adapt and what to do hasnaturally arisen. This year’s Intergovernmental Panel on Climate Change (IPCC) report predicts a global mean temperature rise of up to 4◦C until the end of the century [IPCC, 2007b] and describes the possible effects on human population, industry and geosphere [IPCC, 2007a]. These predictions are based on complex climate models that simulate the natural cycles on Earth. The phenomenal increase in computer power during these last twenty years has allowed more and more details and complexity in the simulation of the global climate. However, every climate model needs to be tested against observational data to validate its results. To this aim data from past climatic conditions need to be measured in various archives.
The reconstruction of past climatic conditions is a primary objective of climate sciences for two reasons. For one, to feed the climate models with data to check if the simulated results recreate the past climate evolution. Then we need to understand the mechanics of interaction between the different parts of the climate system, and to asses the effects of external forcing and internal feedback processes to improve these climate models and obtain more accurate results.
The positive radiative forcing feedback suggested by the IPCC [2007b] report is a sum of different factors, most prominently the greenhouse effect due to natural and anthropogenic emissions of greenhouse gases (fig. 1.1). Another factor are the atmospheric aerosols. These have a direct effect in the sense that they absorb and emit radiation, as well as an indirect effect as condensation nuclei that encourage cloud formation. Both aerosol effects have been found to be a net negative feedback forcing [IPCC, 2007b].
Thus, the reconstruction of past atmospheric aerosol concentration and finding the sources and sinks is an important part in the pursuit to improve our knowledge of the climate system. This work will focus on just one kind of aerosol, albeit arguably the most important: atmospheric dust.
Climate change is recorded in a variety of archives, amongst them ice cores. Dust in polar ice cores is an important source of information on atmospheric aspects of climate because the dust load in polar areas is exclusively of aeolian origin, and thus does not suffer from local disturbances. Microparticles that are deposited on the polar ice sheets originate from continental sources and travel polewards via the troposphere. They reveal information on source region climate and atmospheric conditions on their transport route.
The first introductory chapter provides an overview on the conditions that accompanied the collection of the data used in this work. The ice core that provided this dataset was drilled in the scope of the European Project for Ice Coring in Antarctica (EPICA) at Dome Concordia Station (Dome C) on the East Antarctic Plateau. Measurements were conducted by the means of a Continuous Flow Analysis (CFA) system [Röthlisberger et al., 2000].
The 3200 m of the Dome C ice core depict the climatic variations of the past 800 thousand years (800 ka). The high resolution dust record is presented in the two studies of chapter 3 and 4, along with the non-sea-salt soluble calcium (nssCa2+) in chapter 3, 4, and 6. The description of these datasets provides valuable information in unprecedented detail about past atmospheric climate in the Southern Hemisphere.
During the past 800 ka, glacial/interglacial cycles succeeded each other with an approximate 100 ka periodicity. In the earlier half of the record interglacials were cooler but lasted longer than in recent times. Dust flux to Antarctica and Antarctic temperature are increasingly correlated as climate becomes colder. This relationship is being interpreted as a progressive coupling between the Antarctic and the lower latitudes. Dust source strength and atmospheric particle life time played probably both a major role in the 25-fold glacial dust flux increase.
The high-resolution nssCa2+ and dust records are compared to asses the validity of nssCa2+ as a dust proxy in Antarctica. Results show that this assumption is valid for a first order approach. However, detailed analysis show that specific conclusions on the dust cycle based on nssCa2+ data should be avoided as the conversion is found to be more complex.
High-resolution Ca2+ and Na+ data from Dome C are examined to empirically estimate the marine and terrestrial Ca2+/Na+-ratio. Results diverge from literature values and the sea-salt and non-sea-salt contribution to both Ca2+ and Na+ is reassessed.
The sea-salt and mineral dust aerosol records of the two EPICA ice cores from two different parts of Antarctica are jointly used to estimate dust transport and emission efficiency, as well as to identify regional differences in sea-salt aerosol. A simple conceptual dust transport model is proposed that quantifies the glacial source strength and particle life-time increase. The higher glacial sea-salt aerosol fluxes are ascribed to larger sea-ice extent, perennial sea-ice being assumed to be the main source for sea-salt aerosols.
The interpretation of the two EPICA ice-cores can be understood as one big common task. The studies in chapters 3 to 6 are a contribution to the understanding of the big picture. To get a better overview, more related studies, that were the result of fruitful international collaborations, are detailed in the appendix
Moral Enhancement, Neuroessentialism, and Moral Content
No full textThe conceptualization of morality by some proponents of moral bioenhancement requires particular epistemological commitments and neuroessentialist assumptions. This chapter examines these assumptions and shows why such premises are problematic for the development of a sophisticated framework of morality at the intersection of neuroscience and moral philosophy and why these premises cannot support the possibility of moral enhancement. The author provides conceptual clarity on key concepts in the moral enhancement debate, including the distinction between psychopharmacology and neurotechnologies as means to cognitive enhancement, the meaning of moral enhancement, and the crucial distinction between moral capacity and moral content. Second, he critiques neuroessentialism, pointing to a danger to reduce human behavior to neurobiology and the potential to misconceptualize human moral psychology. Third, he expands his critique of neuroessentialism, particularly with regard to the concept of moral agency and offers a viable alternative based on social practices
Fabrice Mouthon, Le Sourire de Prométhée. L’homme et la nature au Moyen Âge
No full text“Man and Nature”: from a rather clichéd theme, Fabrice Mouthon, a medievalist specializing in rural alpine communities, provides an excellent object of historical study. The author studies the relationship that human societies from the fourth through the sixteenth centuries maintained with nature, the latter understood in the broadest sense of the word: animals, climate, resources, microbes, rivers, forests, landscapes, etc. He develops his analysis of this relationship to nature in three par..
J’ai pris mon père sur mes épaules de Fabrice Melquiot : l’épique du "petit geste"
No full textInternational audienceThe title of Fabrice Melquiot’s play, J’ai pris mon père sur mes épaules, refers to Aeneas’s gesture during the flight from Troy, an episode in which he runs away, carrying his dad Anchise on his back. In this contemporary counter-epic, no privileged relationship with the gods, no creation of a city, no res gestae : heroism as Fabrice Melquiot describes it, comes from this minor episode of the myth and this “small gesture”. The people gathered around Aeneas, residents of a district of Saint-Étienne, can’t aspire to big. This deserted population has nothing left but their bodies as their only means of action. The author then brings out the epic nature of how the destitute help even more deprived and the miraculous energy that moves them.Le titre de la pièce de Fabrice Melquiot J’ai pris mon père sur mes épaules fait référence au geste d’Énée lors de la fuite de Troie, épisode dans lequel celui-ci s’échappe en portant son père Anchise. Dans cette contre-épopée contemporaine, pas de relation privilégiée avec les dieux, pas de fondation de cité, pas de res gestae : l’héroïsme tel que le peint Fabrice Melquiot émane de cet épisode mineur du mythe et de ce « petit geste ». Le peuple réuni autour d’Énée, habitants d’une banlieue de Saint-Étienne, ne peuvent prétendre au « grand » et cette population délaissée est réduite au corps pour seule possession et seul moyen d’action. L’auteur fait alors surgir l’épique de l’aide apportée par les démunis aux encore plus démunis et de l’énergie miraculeuse avec laquelle ils sont mus
Sartre, « miroir critique » de Maupassant dans La Nausée : des « imaginations naturalistes » au fantastique en « trompe-l'œil »
No full textSartre, "Critical Mirror" of Maupassant in Nausea
The literary histories writers implicitly build in their fictions are particularly interesting in what they tell us about the way in which literary fields can or do shift. Sartre's relationship to Maupassant is such an example: that of an author coming of age in the late 1930s, through the 19th century.Thumerel Fabrice. Sartre, « miroir critique » de Maupassant dans La Nausée : des « imaginations naturalistes » au fantastique en « trompe-l'œil ». In: Littérature, n°124, 2001. Histoires littéraires. pp. 50-66
Kréol èk fransé La Rényon : In manir-war sosyolingwistik, épistémolozik, politik
No full textInternational audienceAkoz ékrir in liv linivérsité an kréol ? Fabrice Georger i réponn : akoz pa ? Akoz pa pous plis lwin lang-la dann bann plas lé an zénéral pou le fransé oubyin le langlé ? Pakapab lé mor san éséyé ! Alors, li propoz térla in liv i koz si bann késtyon lingwistik La Rényon, an kréol. San prétansyon, li tash manir rant anparmi le lékipman le lang pou bann dominn ankor tro nèv. Dann son manir-war, li poz le késtyon : kosa i koz La Rényon kan i prétan koz fransé oubyinsa kréol ? Bann « mélanz » i antann i ariv san in lorganizasyon ? Fabrice Georger i tash manir fé inn déskripsyon bann tandans zénéral i antann dann le répértwar kozé le mazorité bann Rényoné kréolofone. Li romark le sintaks i zwé pa le minm rol bann zéléman i konsèrne le fonolozi épisa le léksik. I giny fé osi le diférans rant dé-trwa manir kozé par rapor le sityasyon kominikasyon. Dann bann sityasyon toulézour, li tyinbo ansanm le konsèp le lintérlèk , son Profésér Lambert-Félix Prudent la téorizé. Dann bann sityasyon ousa i aprann, an zénéral dann lékol, bann zénonsé intérléktal partikilyé i kost plis sanm bann manir le lintérlang dé-trwa didaktisyin la dékrir. Li analiz alors térla le koabitasyon le kréol èk le fransé dann in manir intérlèktal épisa konplèks. Le lotér i partaz an gran son bann manirwar épistémolozik, Louis-Jean Calvet, Didier de Robillard èk Philippe Blanchet la bonpé infliansé. Bann trwa dérnyé mené i abord trwa sizé i rès ankor sho La Rényon : le politik lingwistik, le kréol dann lékol épisa son lékritir. Li propoz alors, san prétansyon, partaz son manir-war dann bann gran tinm le kréolistik rényoné
tapir_itsSap_uniq
No full textThis fasta file presents the number of occurrences of each sequence (the first internal transcribed spacer (ITS1) of nuclear ribosomal DNA, for the Sapotaceae ) in the different faecal samples from tapirs.The sequences have been generated by the Illumina technology (Illumina/Solexa Genome Analyzer IIx).The sequences are sorted starting with the most repeated ones among all the samples.
Data collection:
Fabrice Hibert, Pierre Taberlet, Jérôme Chave, Caroline Scotti-Saintagne, Daniel Sabatier , Cécile Richard-Hansen
Contact author:
Fabrice Hibert ([email protected]
tapir_gh_uniq
No full textThis file presents the number of occurrences of each sequence (the trnL P6 loop) in the different faecal samples from tapirs.The sequences have been generated by the Illumina technology (Illumina/Solexa Genome Analyzer IIx).The sequences are sorted starting with the most repeated ones among all the samples.
Data collection:
Fabrice Hibert, Pierre Taberlet, Jérôme Chave, Caroline Scotti-Saintagne, Daniel Sabatier , Cécile Richard-Hansen
Contact author:
Fabrice Hibert ([email protected]
Rencontres autour du Néolithique en Auvergne-Rhône-Alpes
No full textLe 28 juin 2024 se sont tenues au musée des Moulages à Lyon les rencontres autour du Néolithique en Auvergne-Rhône-Alpes (et alentours) (RENARAL-2024). Apolline Lambert a pu y présenter les résultats de ses travaux de Master 1 et 2 et cette journée a permis de faire les liens entre les équipes d'archéologues, d'archéomètres et bioarchéologues. Apolline Lambert, Robert C. Power, Laurent Bouby, Fabrice Bray, Ivy Thomson, Sylvie Saintot, Kerry Sayle, Domingo C. Salazar-García, Marie-France Degu..
Cameroonian medicinal plants belonging to Annonaceae family: radical scavenging and antifungal activities
No full textThe free-radical scavenging activity of ethanolic and methanolic extracts of leaves, stems and roots of Annona muricata, Monodora tenuifolia, Uvaria comperei, Uvaria muricata and Xylopia africana was evaluated using DPPH and ORAC assays. Further, phytochemical analysis, total phenolic and total flavonoid contents were also determined. Moreover, the antifungal activity of extracts was studied. The findings indicated that A. muricata and U. comperei extracts own antiradical activities and moderate antifungal properties
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