37 research outputs found
India-China: Intersecting Universalities
This collection of articles is mainly the result of an international conference organised by the Chair of Chinese Intellectual History at the CollĂšge de France in June 2017. Entitled âIndia-China: Intersecting Universalitiesâ, it brought together scholars from Asia, America and Europe who have been interested in one aspect or other of the cultural interactions between India and China. The diversity of the topics testifies to the lively interest raised by the intersection of two heavyweights of area and cultural studies. What makes the relationship between âChinaâ and âIndiaâ so remarkably interesting is that one can hardly imagine two civilisational worlds as radically different from each other, which yet managed somehow to come into contact and to interact. The aim of the present volume is to look at various aspects of the cultural exchanges between India and China at different points of history. It is to try and remedy a certain indifference and mutual ignorance in our day and age that we bring forward this collective venture with the hope of offering to our readers alternative approaches to the connections between these two âgiants of Asiaâ, other than the merely geopolitical ones that fill our media today
The Role of Diagenesis at Vera Rubin Ridge in Gale Crater, Mars, and the Chemostratigraphy of the Murray Formation as Observed by the Chemcam Instrument
The Mars Science Laboratory (MSL) Curiosity rover explored Vera Rubin ridge (VRR) in Gale crater, Mars, for almost 500 sols (Mars days) between arriving at the ridge on sol 1809 of the mission in September 2017 and leaving it on sol 2302 upon entering the Glen Torridon area south of the ridge. VRR is a topographic ridge on the central mound, Aeolis Mons (Mt. Sharp), in Gale crater that displays a strong hematite spectral signature from orbit. In-situ observations on the ridge led to the recognition that the ridge-forming rocks belong to the Murray formation, the lowermost exposed stratigraphic unit of the Mt. Sharp group, that was first encountered at the Pahrump Hills location. Including VRR rocks, the Murray formation, interpreted to be primarily deposited in an ancient lacustrine environment in Gale crater, is more than 300 m thick. VRR itself is composed of two stratigraphic members within the Murray formation, the Pettegrove Point member overlain by the Jura member. The Pettegrove Point member overlies the Blunts Point member of the Murray formation. Areas of gray coloration are observed in the Jura member predominantly, but also in the Pettegrove Point member. Generally, gray areas are found in local topographic depressions, but contacts between red and gray rocks crosscut stratigraphy. Additionally, cm-scale dark concretions with very high iron-content are commonly observed in gray rocks, typically surrounded by a lighttoned zone that is conversely depleted in iron. A key goal for the VRR campaign was to characterize geochemical variations in the ridge-forming rocks to investigate the role of primary and diagenetic controls on the geochemistry and morphology of VRR. Here, we present observations by the ChemCam instrument on VRR and compare these to the full Murray formation chemostratigraphy. This work was recently submitted to a special issue of JGRPlanets that detail the full VRR campaign
Iron Mobility during Diagenesis at Vera Rubin ridge, Gale Crater, Mars
The Curiosity rover investigated a topographic structure known as Vera Rubin ridge, associated with a hematite signature in orbital spectra. There, Curiosity encountered mudstones interpreted as lacustrine deposits, conformably overlying the 300 mâthick underlying sedimentary rocks of the Murray formation at the base of Mount Sharp. While the presence of hematite (αâFe2O3) was confirmed inâsitu by both Mastcam and ChemCam spectral observations and by the CheMin instrument, neither ChemCam nor APXS observed any significant increase in FeOT (total iron oxide) abundances compared to the rest of the Murray formation. Instead, Curiosity discovered darkâtoned diagenetic features displaying anomalously high FeOT abundances, commonly observed in association with lightâtoned Caâsulfate veins but also as crystal pseudomorphs in the host rock. These ironârich diagenetic features are predominantly observed in âgreyâ outcrops on the upper part of the ridge, which lack the telltale ferric signature of other Vera Rubin ridge outcrops. Their composition is consistent with anhydrous Feâoxide, as the enrichment in iron is not associated with enrichment in any other elements, nor with detections of volatiles. The lack of ferric absorption features in the ChemCam reflectance spectra and the hexagonal crystalline structure associated with darkâtoned crystals points toward coarse âgreyâ hematite. In addition, the host rock adjacent to these features appears bleached and show lowâFeOT content as well as depletion in Mn, indicating mobilization of these redoxâsensitive elements during diagenesis. Thus, groundwater fluid circulations could account for the remobilization of iron and recrystallization as crystalline hematite during diagenesis on Vera Rubin ridge
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Accommodating stake effects under prospect theory
One of the stylized facts underlying prospect theory is a four-fold pattern of risk preferences. People have been shown to be risk seeking for small probability gains and large probability losses, while being risk averse for large probability gains and small probability losses. Another fourfold pattern of risk preferences over outcomes, postulated by Harry Markowitz in 1952, has received much less attention and is
currently not integrated into prospect theory. In two experiments, we show that risk preferences may change over outcomes. While we find people to be risk seeking for small outcomes, this turns to risk neutrality and later risk aversion as stakes increase. We then show how a one-parameter logarithmic utility function fits such stake effects significantly better under prospect theory than the power or exponential functions mostly used when fitting prospect theory models. We further investigate the extent to which the use of ill-suited functional forms to represent utility may result in violations of prospect theory, and whether such violations disappear when using logarithmic utility
Measuring loss aversion under ambiguity: a method to make prospect theory completely observable
We propose a simple, parameter-free method that, for the first time, makes it possible to completely observe Tversky and Kahnemanâs (1992) prospect theory. While methods exist to measure event weighting and the utility for gains and losses separately, there was no method to measure loss aversion under ambiguity. Our method allows this and thereby it can measure prospect theoryâs entire utility function. Consequently, we can properly identify properties of utility and perform new tests of prospect theory. We implemented our method in an experiment and obtained support for prospect theory. Utility was concave for gains and convex for losses and there was substantial loss aversion. Both utility and loss aversion were the same for risk and ambiguity, as assumed by prospect theory, and sign-comonotonic trade-off consistency, the central condition of prospect theory, held
Deltaproteobacteria (Pelobacter) and Methanococcoides are responsible for choline-dependent methanogenesis in a coastal saltmarsh sediment
Coastal saltmarsh sediments represent an important source of natural methane emissions, much of which originates from quaternary and methylated amines, such as choline and trimethylamine. In this study, we combine DNA stable isotope probing with high throughput sequencing of 16S rRNA genes and 13C2-choline enriched metagenomes, followed by metagenome data assembly, to identify the key microbes responsible for methanogenesis from choline. Microcosm incubation with 13C2-choline leads to the formation of trimethylamine and subsequent methane production, suggesting that choline-dependent methanogenesis is a two-step process involving trimethylamine as the key intermediate. Amplicon sequencing analysis identifies Deltaproteobacteria of the genera Pelobacter as the major choline utilizers. Methanogenic Archaea of the genera Methanococcoides become enriched in choline-amended microcosms, indicating their role in methane formation from trimethylamine. The binning of metagenomic DNA results in the identification of bins classified as Pelobacter and Methanococcoides. Analyses of these bins reveal that Pelobacter have the genetic potential to degrade choline to trimethylamine using the choline-trimethylamine lyase pathway, whereas Methanococcoides are capable of methanogenesis using the pyrrolysine-containing trimethylamine methyltransferase pathway. Together, our data provide a new insight on the diversity of choline utilizing organisms in coastal sediments and support a syntrophic relationship between Bacteria and Archaea as the dominant route for methanogenesis from choline in this environment
Culture dependent and independent analyses of 16S rRNA and ATP citrate lyase genes : a comparison of microbial communities from different black smoker chimneys on the Mid-Atlantic Ridge
Author Posting. © Springer, 2008. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Extremophiles 12 (2008): 627-640, doi:10.1007/s00792-008-0167-5.The bacterial and archaeal communities of three deep-sea hydrothermal vent systems
located on the Mid-Atlantic Ridge (MAR; Rainbow, Logatchev and Broken Spur) were
investigated using an integrated culture-dependent and independent approach.
Comparative molecular phylogenetic analyses, using the 16S rRNA gene and the deduced
amino acid sequences of the alpha and beta subunits of the ATP citrate lyase encoding
genes were carried out on natural microbial communities, on an enrichment culture
obtained from the Broken Spur chimney, and on novel chemolithoautotrophic bacteria
and reference strains originally isolated from several different deep-sea vents. Our data
showed that the three MAR hydrothermal vent chimneys investigated in this study host
very different microbial assemblages. The microbial community of the Rainbow chimney
was dominated by thermophilic, autotrophic, hydrogen-oxidizing, sulfur- and nitrate
reducing Epsilonproteobacteria related to the genus Caminibacter. The detection of
sequences related to sulfur-reducing bacteria and archaea (Archaeoglobus) indicated that
thermophilic sulfate reduction might also be occurring at this site. The Logatchev
bacterial community included several sequences related to mesophilic sulfur-oxidizing
bacteria, while the archaeal component of this chimney was dominated by sequences
related to the ANME-2 lineage, suggesting that anaerobic oxidation of methane may be
occurring at this site. Comparative analyses of the ATP citrate lyase encoding genes from
natural microbial communities suggested that Epsilonproteobacteria were the dominant
primary producers using the reverse TCA cycle (rTCA) at Rainbow, while Aquificales of
the genera Desulfurobacterium and Persephonella were prevalent in the Broken Spur
chimney.This research was supported by NSF grants MCB 04-56676 (C.V.), OCE 03-27353 (C.V.), MCB 04-56689 (S.M.S.), a grant from the New Jersey Agricultural Experiment Station to C.V., and a NIH Ph.D. Training
Program in Biotechnology Fellowship (NIH NIGMS 5 T32 GM08339) to J.V. M.H. was
supported through a postdoctoral scholarship from the Woods Hole Oceanographic
Institution
Relationship between self-organization and size of InAs islands on InP(001) grown by gas-source molecular beam epitaxy
Using the strained-induced 2Dâ3D transition, InAs dots have been grown on InP(001) and examined by transmission electron microscopy. Two different modes of island size and spatial distribution have been identified. For deposit of 1.5 and 1.8 monolayers, the islands are about 7 nm high and randomly distributed. Above 2 monolayers, they are about five times smaller in volume and locally self-organized, with a typical distance of 40 nm independent of the island density. It is suggested that the strong dependence of the island size on the total amount of deposited InAs is mainly due to long range interactions through the substrate