471 research outputs found

    How agency models inspire large scale participatory planning and its evaluation

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    International audienceWe describe how three models, for sustainable change, human agency in collective resource management, and socio-environmental systems, have been used to design a protocol and the tools for a large scale (1500 participants, 35 villages) multi-level participatory process held in Africa for Integrated Natural Resource Management, through the European Project Afromaison. The process especially combines a common action model to support proposals by stakeholders, an integration matrix to build coherent plans, a role playing game design process, and a method to combine planning and playing to engage into the plans. It has also inspired the design of the attached monitoring and evaluation process. We describe the process in two countries, Ethiopia and Uganda, present the theoretical bases of the evaluation framework using the ENCORE paradigm and the implemented methodology transferred to local evaluators. We introduce some results and propose comments on potential learning back to the modelling community

    Light-Induced Activation of a Molybdenum Oxotransferase Model within a Ru(II)-Mo(VI) Dyad

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    Nature uses molybdenum-containing enzymes to catalyze oxygen atom transfer (OAT) from water to organic substrates. In these enzymes, the two electrons that are released during the reaction are rapidly removed, one at a time, by spatially separated electron transfer units. Inspired by this design, a Ru(II)-Mo(VI) dyad was synthesized and characterized, with the aim of accelerating the rate-determining step in the cis-dioxo molybdenum-catalyzed OAT cycle, the transfer of an oxo ligand to triphenyl phosphine, via a photo-oxidation process. The dyad consists of a photoactive bis(bipyridyl)-phenanthroline ruthenium moiety that is covalently linked to a bioinspired cis-dioxo molybdenum thiosemicarbazone complex. The quantum yield and luminescence lifetimes of the dyad [Ru(bpy)2(L(2))MoO2(solv)](2+) were determined. The major component of the luminescence decay in MeCN solution (τ = 1149 ± 2 ns, 67%) corresponds closely to the lifetime of excited [Ru(bpy)2(phen-NH2)](2+), while the minor component (τ = 320 ± 1 ns, 31%) matches that of [Ru(bpy)2(H2-L(2))](2+). In addition, the (spectro)electrochemical properties of the system were investigated. Catalytic tests showed that the dyad-catalyzed OAT from dimethyl sulfoxide to triphenyl phosphine proceeds significantly faster upon irradiation with visible light than in the dark. Methylviologen acts as a mediator in the photoredox cycle, but it is regenerated and hence only required in stoichiometric amounts with respect to the catalyst rather than sacrificial amounts. It is proposed that oxidative quenching of the photoexcited Ru unit, followed by intramolecular electron transfer, leads to the production of a reactive one-electron oxidized catalyst, which is not accessible by electrochemical methods. A significant, but less pronounced, rate enhancement was observed when an analogous bimolecular system was tested, indicating that intramolecular electron transfer between the photosensitizer and the catalytic center is more efficient than intermolecular electron transfer between the separate components

    Rationality and the experimental study of reasoning

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    A survey of the results obtained during the past three decades in some of the most widely used tasks and paradigms in the experimental study of reasoning is presented. It is shown that, at first sight, human performance suffers from serious shortcomings. However, after the problems of communication between experimenter and subject are taken into account, which leads to clarify the subject's representation of the tasks, one observes a better performance, although still far from perfect. Current theories of reasoning, of which the two most prominent are very briefly outlined, agree in identifying the load in working memory as the main source of limitation in performance. Finally, a recent view on human rationality prompted by the foregoing results is described

    Accumulating discursive capital, valuating subject positions. From Marx to Foucault

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    Whenever people use language, they participate in valuation practices, i.e. they give value to themselves as well as to others. To account for the construction of social inequality through discursive valuation practices, discourse theorists need Marxist theory and Marxists need discourse theory. By going from the early Marx to the late Foucault, I will revisit Marx?s value theory in light of practice-oriented approaches to social inequality. I will discuss examples from two distinct arenas, the monopolization of attention by populist leaders and the academic star system, both of which are accounted for in terms of the accumulation of discursive capital. This perspective asks how the value of subject positions is constructed and hierarchies between them are established in discursive practices. Investigating the construction of valuable subject positions in discourse communities, this perspective attempts to overcome the traditional division between language, the economic and the social. Discourse not only represents value and the social order but, through representation, it also contributes to constituting the social as a hierarchical world of more or less valued subject positions

    Development of the SPECULOOS exoplanet search project

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    SPECULOOS (Search for habitable Planets EClipsing ULtra-cOOl Stars) aims to perform a transit search on the nearest (<40<40pc) ultracool (<3000<3000K) dwarf stars. The project's main motivation is to discover potentially habitable planets well-suited for detailed atmospheric characterisation with upcoming giant telescopes, like the James Webb Space Telescope (JWST) and European Large Telescope (ELT). The project is based on a network of 1m robotic telescopes, namely the four ones of the SPECULOOS-Southern Observatory (SSO) in Cerro Paranal, Chile, one telescope of the SPECULOOS-Northern Observatory (SNO) in Tenerife, and the SAINT-Ex telescope in San Pedro M\'artir, Mexico. The prototype survey of the SPECULOOS project on the 60~cm TRAPPIST telescope (Chile) discovered the TRAPPIST-1 system, composed of seven temperate Earth-sized planets orbiting a nearby (12~pc) Jupiter-sized star. In this paper, we review the current status of SPECULOOS, its first results, the plans for its development, and its connection to the Transiting Exoplanet Survey Satellite (TESS) and JWST

    TOI-2257 b: A highly eccentric long-period sub-Neptune transiting a nearby M dwarf

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    Context. Thanks to the relative ease of finding and characterizing small planets around M-dwarf stars, these objects have become cornerstones in the field of exoplanet studies. The current paucity of planets in long-period orbits around M dwarfs makes such objects particularly compelling as they provide clues about the formation and evolution of these systems. Aims. In this study we present the discovery of TOI-2257 b (TIC 198485881), a long-period (35 d) sub-Neptune orbiting an M3 star at 57.8 pc. Its transit depth is about 0.4%, large enough to be detected with medium-size, ground-based telescopes. The long transit duration suggests the planet is in a highly eccentric orbit (e ∌ 0.5), which would make it the most eccentric planet known to be transiting an M-dwarf star. Methods. We combined TESS and ground-based data obtained with the 1.0-meter SAINT-EX, 0.60-meter TRAPPIST-North, and 1.2-meter FLWO telescopes to find a planetary size of 2.2 R⊕ and an orbital period of 35.19 days. In addition, we make use of archival data, high-resolution imaging, and vetting packages to support our planetary interpretation. Results. With its long period and high eccentricity, TOI-2257 b falls into a novel slice of parameter space. Despite the planet’s low equilibrium temperature (∌256 K), its host star’s small size (R∗ = 0.311 ± 0.015) and relative infrared brightness (Kmag = 10.7) make it a suitable candidate for atmospheric exploration via transmission spectroscopy.Fil: Schanche, N.. University of Bern; SuizaFil: Pozuelos, F. J.. UniversitĂ© de LiĂšge; BĂ©lgicaFil: GĂŒnther, M. N.. Massachusetts Institute of Technology; Estados Unidos. Agencia Espacial Europea. European Space Research And Technology Centre.; PaĂ­ses BajosFil: Wells, R. D.. University of Bern; SuizaFil: Burgasser, A. J.. University of California at San Diego; Estados UnidosFil: Chinchilla, P.. UniversitĂ© de LiĂšge; BĂ©lgica. Instituto de AstrofĂ­sica de Canarias; EspañaFil: Delrez, L.. UniversitĂ© de LiĂšge; BĂ©lgicaFil: Ducrot, E.. UniversitĂ© de LiĂšge; BĂ©lgicaFil: Garcia, L. J.. UniversitĂ© de LiĂšge; BĂ©lgicaFil: GĂłmez Maqueo Chew, Y.. Universidad Nacional AutĂłnoma de MĂ©xico. Instituto de AstronomĂ­a; MĂ©xicoFil: Jofre, Jorge Emiliano. Universidad Nacional AutĂłnoma de MĂ©xico. Instituto de AstronomĂ­a; MĂ©xico. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - CĂłrdoba. Instituto de AstronomĂ­a TeĂłrica y Experimental. Universidad Nacional de CĂłrdoba. Observatorio AstronĂłmico de CĂłrdoba. Instituto de AstronomĂ­a TeĂłrica y Experimental; ArgentinaFil: Rackham, B. V.. Massachusetts Institute of Technology; Estados UnidosFil: Sebastian, D.. University of Birmingham; Reino UnidoFil: Stassun, K. G.. Vanderbilt University; Estados UnidosFil: Stern, D.. California Instituto Of Technology. Departament Of Mechanical And Civil Engineering; Estados UnidosFil: Timmermans, M.. UniversitĂ© de LiĂšge; BĂ©lgicaFil: Barkaoui, K.. UniversitĂ© de LiĂšge; BĂ©lgica. Cadi Ayyad University; MarruecosFil: Belinski, A.. Moscow State University; RusiaFil: Benkhaldoun, Z.. Cadi Ayyad University; MarruecosFil: Benz, W.. University of Bern; SuizaFil: Bieryla, A.. Harvard-Smithsonian Center for Astrophysics; Estados UnidosFil: Bouchy, F.. Observatorio de Ginebra; SuizaFil: Burdanov, A.. Massachusetts Institute of Technology; Estados UnidosFil: Charbonneau, D.. Harvard-Smithsonian Center for Astrophysics; Estados UnidosFil: Christiansen, J. L.. Centro de AnĂĄlisis y Procesamiento Infrarrojo; Estados Unidos. National Aeronautics and Space Administration; Estados UnidosFil: Collins, K. A.. Harvard-Smithsonian Center for Astrophysics; Estados UnidosFil: Demory, Brice Olivier. University of Bern; SuizaFil: DĂ©vora Pajares, M.. Universidad de Granada; EspañaFil: De Wit, J.. Massachusetts Institute of Technology; Estados UnidosFil: Dragomir, D.. University of New Mexico; Estados Unido

    First narrow-band search for continuous gravitational waves from known pulsars in advanced detector data

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    Spinning neutron stars asymmetric with respect to their rotation axis are potential sources of continuous gravitational waves for ground-based interferometric detectors. In the case of known pulsars a fully coherent search, based on matched filtering, which uses the position and rotational parameters obtained from electromagnetic observations, can be carried out. Matched filtering maximizes the signalto- noise (SNR) ratio, but a large sensitivity loss is expected in case of even a very small mismatch between the assumed and the true signal parameters. For this reason, narrow-band analysis methods have been developed, allowing a fully coherent search for gravitational waves from known pulsars over a fraction of a hertz and several spin-down values. In this paper we describe a narrow-band search of 11 pulsars using data from Advanced LIGO’s first observing run. Although we have found several initial outliers, further studies show no significant evidence for the presence of a gravitational wave signal. Finally, we have placed upper limits on the signal strain amplitude lower than the spin-down limit for 5 of the 11 targets over the bands searched; in the case of J1813-1749 the spin-down limit has been beaten for the first time. For an additional 3 targets, the median upper limit across the search bands is below the spin-down limit. This is the most sensitive narrow-band search for continuous gravitational waves carried out so far
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