54 research outputs found

    Gravitational birefringence and an exotic formula for redshift

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    16 pages, 2 figuresInternational audienceWe compute the birefringence of light in curved Robertson-Walker spacetimes and propose an exotic formula for redshift based on the internal structure of the spinning photon. We then use the Hubble diagram of supernovae to test this formula

    SMEs entry mode decision making process: Rational or cybernetic?

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    Entry mode choice is a critical decision when a firm expends its business to foreign markets. By applying rational and cybernetic strategies to international strategic decision-making process, this paper investigates how small and medium sized firms (SMEs) decision makers decide their entry mode choices. By focusing on the entry decision making process, this research distinguishes the prior entry mode studies that emphasize the relationship between influencing factors and their impacts on entry mode choices. The results of this study show that SME managers normally adapt a combination of rational and cybernetic strategies in their international entry decision making process. This highlights that SMEs’ international entry decision making process is dynamic and complex

    Noticing Future Me: Reducing Egocentrism Through Mental Imagery.

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    People drastically overestimate how often others attend to them or notice their unusual features, a phenomenon termed the spotlight effect Despite the prevalence of this egocentric bias, little is known about how to reduce the tendency to see oneself as the object of others' attention. Here, we tested the hypothesis that a basic property of mental imagery-the visual perspective from which an event is viewed-may alleviate a future-oriented variant of the spotlight effect. The results of three experiments supported this prediction. Experiment 1 revealed a reduction in egocentric spotlighting when participants imagined an event in the far compared with near future. Experiments 2 and 3 demonstrated reduced spotlighting and feelings of embarrassment when participants viewed an impending event from a third-person (vs. first-person) vantage point. Simple changes in one's visual perspective may be sufficient to diminish the illusion of personal salience

    The identification of economically relevant health and social care services for mental disorders in the PECUNIA project

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    Background: Health economic research is still facing significant problems regarding the standardization and international comparability of health care services. As a result, comparative effectiveness studies and cost-effectiveness analyses are often not comparable. This study is part of the PECUNIA project, which aimed to improve the comparability of economic evaluations by developing instruments for the internationally standardized measurement and valuation of health care services for mental disorders. The aim of this study was to identify internationally relevant services in the health and social care sectors relevant for health economic studies for mental disorders. Methods: A systematic literature review on cost-of-illness studies and economic evaluations was conducted to identify relevant services, complemented by an additional grey literature search and a search of resource use measurement (RUM) questionnaires. A preliminary long-list of identified services was explored and reduced to a short-list by multiple consolidation rounds within the international research team and an external international expert survey in six European countries. Results: After duplicate removal, the systematic search yielded 15,218 hits. From these 295 potential services could be identified. The grey literature search led to 368 and the RUM search to 36 additional potential services. The consolidation process resulted in a preliminary list of 186 health and social care services which underwent an external expert survey. A final consolidation step led to a basic list of 56 services grouped into residential care, daycare, outpatient care, information for care, accessibility to care, and self-help and voluntary care. Conclusions: The initial literature searches led to an extensive number of potential service items for health and social care. Many of these items turned out to be procedures, interventions or providing professionals rather than services and were removed from further analysis. The resulting list was used as a basis for typological coding, the development of RUM questionnaires and corresponding unit costs for international mental health economic studies in the PECUNIA project.</p

    Eco-valuation of the Kniphofia uvaria plant : from the plant to the galenic form

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    À l’heure oĂč l’intĂ©gration des enjeux environnementaux dans le dĂ©veloppement de procĂ©dĂ©s Ă©co-efficients joue un rĂŽle essentiel dans le moteur de l’innovation responsable, la chimie verte est devenue l’un des sujets de prĂ©occupation majeure. Ainsi, le dĂ©veloppement de nouveaux procĂ©dĂ©s Ă©co-respectueux pour la production d’ingrĂ©dients naturels issus de matiĂšres premiĂšres vĂ©gĂ©tales renouvelables est devenu une dĂ©marche incontournable dans le modĂšle de recherche. L’objectif de cette thĂšse a consistĂ© au dĂ©veloppement d’une stratĂ©gie d’éco-valorisation innovante employant les fluides sub/supercritiques pour l’extraction, la caractĂ©risation, la production et l’imprĂ©gnation sur support cosmĂ©tique de produits naturels d’origine vĂ©gĂ©tale. Pour cela, nous avons utilisĂ© comme modĂšle vĂ©gĂ©tal : les graines olĂ©agineuses de la plante Kniphofia uvaria, sĂ©lectionnĂ©e pour des applications cosmĂ©tiques grĂące Ă  ses propriĂ©tĂ©s bioactives antioxydantes et anti-Ăąge. Dans un premier temps, le dĂ©veloppement de mĂ©thodes complĂ©mentaires en SFC ainsi que le dĂ©veloppement du couplage SFC-MS a Ă©tĂ© rĂ©alisĂ© Ă  l’aide de la source APCI afin d’identifier les molĂ©cules responsables des activitĂ©s bioactives des graines de Kniphofia uvaria. Ainsi, le dĂ©veloppement d’un systĂšme hybride (U)HPLC/SFC-HRMS a Ă©tĂ© rĂ©alisĂ© afin de mettre en place ce couplage. Des optimisations en termes de proportion et nature de solvant make-up ainsi qu’un travail au niveau des paramĂštres SFC et MS ont Ă©tĂ© faits afin de d’amĂ©liorer la sensibilitĂ© et la spĂ©cificitĂ© des analyses lipidiques. Dans un second temps, nous nous sommes attachĂ©s au dĂ©veloppement d’une stratĂ©gie d’enrichissement en composĂ©s bioactifs Ă  l’aide des mĂ©thodes : SFE et CPC. Ainsi, en SFE, des optimisations en termes de tempĂ©rature, pression, nature/proportions de co-solvant dans le fluide ont Ă©tĂ© rĂ©alisĂ©es alors qu’en CPC, des optimisations au niveau de l’injection ont Ă©tĂ© faites. Des conditions optimales pour le fractionnement sĂ©lectif des anthraquinones et des triglycĂ©rides ont Ă©tĂ© dĂ©terminĂ©es en SFE et CPC. Dans un dernier temps, ce travail a consistĂ© Ă  dĂ©velopper un couplage en-ligne pour extraire et imprĂ©gner sĂ©lectivement sur silice cosmĂ©tique : les anthraquinones. Le dĂ©veloppement et l’optimisation de ce procĂ©dĂ© en-ligne ont Ă©tĂ© rĂ©alisĂ©s Ă  l’échelle du laboratoire et ont dĂ©montrĂ© la faisabilitĂ© de ce couplage ainsi qu’un intĂ©rĂȘt certain pour l’obtention de produits naturels sous une premiĂšre forme galĂ©nique, destinĂ©e Ă  une future incorporation dans la formulation de cosmĂ©tiques.Nowadays, green chemistry is a great challenge. It seeks innovation in the development of eco-efficient processes. The production of natural products from renewable materials by these new environmentally friendly processes is more and more used. The aim of this Ph.D thesis is to develop an eco-valuation strategy to extract, characterize, produce and impregnate natural products onto a cosmetic support using sub/supercritical fluids. Consequently, we used oleaginous plant seeds from Kniphofia uvaria as a plant model, which was selected for its interesting cosmetic properties such as antioxidant or anti-ageing. Firstly, the SFC-MS hyphenation with the APCI as an ionization source was developed to screen bioactive molecules; responsible of cosmetic properties. This coupling was performed by the hybrid combination of (U)HPLC/SFC-HRMS. Various optimizations in terms of the solvent make-up (nature and proportion), modulation with SFC and MS parameters were carried out in order to improve sensitivity and selectivity of lipid analysis. Secondly, an enrichment strategy to concentrate bioactive compounds in the final extract was developed by SFE and CPC. Thus, in SFE, experimental parameters (temperature, pressure, nature/proportion of the modifier in the CO2 fluid) were optimized while in CPC, the injection optimization was realized. Methods for the selective fractionation of anthraquinones and triglycerides were obtained in CPC and SFE. Finally, an on-line sub/supercritical extraction-impregnation process was developed to extract and for simultaneously impregnating anthraquinones onto a cosmetic silica. Development and optimization of this process was realized on a laboratory scale. Consequently, this study demonstrated the feasibility of this concept and it presents a great interest to provide natural products as a galenic form, which could be used in the cosmetic formulation

    An adaptive procedure for Fourier estimators: illustration to deconvolution and decompounding

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    We introduce a new procedure to select the optimal cutoff parameter for Fourier density estimators that leads to adaptive rate optimal estimators, up to a logarithmic factor. This adaptive procedure applies for different inverse problems. We illustrate it on two classical examples: deconvolution and decompounding, i.e. non-parametric estimation of the jump density of a compound Poisson process from the observation of n increments of length ∆ > 0. For this latter example, we first build an estimator for which we provide an upper bound for its L 2-risk that is valid simultaneously for sampling rates ∆ that can vanish, ∆ := ∆ n → 0, can be fixed, ∆ n → ∆ 0 > 0 or can get large, ∆ n → ∞ slowly. This last result is new and presents interest on its own. Then, we show that the adaptive procedure we present leads to an adaptive and rate optimal (up to a logarithmic factor) estimator of the jump density
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