Search results for "figuration"
showing 10 items of 615 documents
Economies d'agglomération et configurations spatiales dans les espaces ruraux
1997
The question to be addressed here is that of the agglomeration/dispersion forces that are likely to account for the location of people and jobs in rural areas and the way they explain spatial patterns in rural areas depending on urban influence. Economic geography models may provide suitable tools with which to investigate the organization of rural areas. We first review these models, focusing on dispersion forces, which rest basically on land consumption and transport costs. We suggest then a set of hypotheses concerning the main forces at work in rural areas. Intensity of agglomeration economies is hypothesized to be related to the urban size, which in turn induces increasing land rents a…
Significations, figures, formes et traces : penser les interactions à travers l’écriture d’une communauté d’alumni en ligne
2015
National audience; Ce chapitre examine les interactions en ligne entre des membres d’une communauté d’alumni. Il considère que ces interactions, qui se manifestent sous l’unique forme de traces écrites, permettent aux membres d’un groupe de participer à la performance d’une culture et d’une identité collectives, mais aussi à tout un chacun de se démarquer sur le plan identitaire. Sur le plan théorique, le chapitre met en relation le modèle sémiopragmatique des interactions (Frame et Boutaud), l’approche ventriloque de François Cooren, inspiré de la théorie de l’Acteur-réseau (Latour), et le paradigme de l’Homme trace. Ce paradigme nous aide à mieux comprendre le rôle des objets à côté des a…
Neighborhood resources associated with active travel in older adults: A cohort study in six European Countries
2020
Objectives: To study associations between perceived neighborhood resources and time spent by older adults in active travel. Methods: Respondents in six European countries, aged 65–85 years, reported on the perceived presence of neighborhood resources (parks, places to sit, public transportation, and facilities) with response options “a lot,” “some,” and “not at all.” Daily active travel time (total minutes of transport-related walking and cycling) was self-reported at the baseline (n = 2,695) and 12–18 months later (n = 2,189). Results: Reporting a lot of any of the separate resources (range B’s = 0.19–0.29) and some or a lot for all four resources (B = 0.22, 95% confidence interval [0.09, …
De-excitation of the strongly coupled band in 177Au and implications for core intruder configurations in the light Hg isotopes
2017
International audience; Excited states in the proton-unbound nuclide $^{177}$Au were populated in the $^92}$Mo($^{88}$Sr, p2n) reaction and identified using the Jurogam-II and GREAT spectrometers in conjunction with the RITU gas-filled separator at the University of Jyväskylä Accelerator Laboratory. A strongly coupled band and its decay path to the 11/2−α-decaying isomer have been identified using recoil-decay tagging. Comparisons with cranked Hartree-Fock-Bogoliubov (HFB) calculations based on Skyrme energy functionals suggest that the band has a prolate deformation and is based upon coupling the odd 1h11/2 proton hole to the excited 02+ configuration in the $^{178}$Hg core. Although these…
Targeted solid phase fermentation of the soil dwelling fungus Gymnascella dankaliensis yields new brominated tyrosine-derived alkaloids
2016
Seven new brominated tyrosine-derived alkaloids, gymnastatins T–Y (1–6) and dankastatin D (7), together with three known likewise brominated analogues gymnastatins I–K (8–10) were isolated from the soil fungus Gymnascella dankaliensis through fermentation on solid rice medium following addition of NaBr. None of these compounds were detected when the fungus was cultured on rice that either lacked NaBr or that contained NaCl instead, indicating a remarkable plasticity of the fungal secondary metabolism. All structures were elucidated on the basis of one and two dimensional NMR spectroscopic analyses and MS data. The absolute configuration of the new gymnastatin T (1) was determined by X-ray c…
Xanthones and sesquiterpene derivatives from a marine-derived fungus Scopulariopsis sp.
2016
Abstract Two new xanthone derivatives, 12-dimethoxypinselin ( 1 ) and 12- O -acetyl-AGI-B4 ( 2 ), as well as two new phenolic bisabolane-type sesquiterpenes, 11,12-dihydroxysydonic acid ( 15 ) and 1-hydroxyboivinianic acid ( 16 ), together with one new alkaloid, scopulamide ( 21 ) and one new α-pyrone derivative, scopupyrone ( 26 ), in addition to twenty-three known compounds ( 3 – 14 , 17 – 20 , 22 – 25 , 27 – 29 ) were isolated from solid rice cultures of the marine-derived fungus Scopulariopsis sp. obtained from the Red Sea hard coral Stylophora sp. All compounds were unambiguously identified through extensive NMR spectroscopic analyses, and by comparison with the literature. Marfey's re…
Secondary metabolites of the lichen-associated fungus Apiospora montagnei
2017
Abstract The endolichenic fungus Apiospora montagnei isolated from the lichen Cladonia sp. was cultured on solid rice medium, yielding the new diterpenoid libertellenone L (1), the new pyridine alkaloid, 23-O-acetyl-N-hydroxyapiosporamide (2) and the new xanthone derivative 8-hydroxy-3-hydroxymethyl-9-oxo-9H-xanthene-1-carboxylic acid methyl ether (3) together with 19 known compounds (4–22). The structures of the new compounds were elucidated by 1D and 2D NMR spectra as well as by HRESIMS data. The absolute configuration of the new 6,7-seco-libertellenone derivative 1 was determined by single-crystal X-ray diffraction. Four additional known compounds 23–26 were isolated when NaCl or NH4Cl w…
New oxygenated eudesmanolides from artemisia herba-alba
1990
Abstract The aerial parts of Artemisia herba-alba Asso subsp.valentina Lam. (Asteraceae) yielded the new eudesmanolides 1-11 and the new sesquiterpene-monoterpene adducts 12-13. The absolute configuration of compound 6 was confirmed with the aid of X-ray diffraction analysis. Some aspects of the thermal and photochemical reactivity of 2,4-cyclohexadienones are discussed.
Two new metabolites from the endophytic fungus Xylaria sp. isolated from the medicinal plant Curcuma xanthorrhiza
2015
Abstract The endophytic fungus Xylaria sp. was isolated from healthy leaves of Curcuma xanthorrhiza, collected on the island of Timor, Indonesia. Two new compounds (1 and 2), together with the known resacetophenone (3), were isolated and their structures were elucidated on the basis of comprehensive NMR and mass spectral analyses. The enantiomers of rac-1 were separated by chiral HPLC and their HPLC-ECD spectra were recorded to determine the absolute configuration on the basis of TDDFT-ECD calculations. The (3R,3aR, 9aR) absolute configuration of the optically active 2 was established by comparing the experimental solution ECD spectrum with the TDDFT ones computed for the gas phase and solu…
Expanding the chemical diversity of an endophytic fungus Bulgaria inquinans, an ascomycete associated with mistletoe, through an OSMAC approach
2019
An endophytic fungus Bulgaria inquinans (isolate MSp3-1), isolated from mistletoe (Viscum album), was subjected to fermentation on solid Czapek medium. Chromatographic workup of the crude EtOAc extract yielded five new natural products (1–5). Subsequent application of the “One Strain, MAny Compounds” (OSMAC) strategy on this strain by the addition of a mixture of salts (MgSO4, NaNO3 and NaCl) to solid Czapek medium induced the accumulation of nine additional new secondary metabolites (6–13, 16), with most of them (8, 10–12) not detectable in cultures lacking the salt mixture. The structures of the new compounds were established on the basis of the 1D/2D NMR and HRESIMS data. The TDDFT-ECD m…