| 1. |
- l'Haridon, O., et al.
(författare)
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Off the Charts: Massive Unexplained Heterogeneity in a Global Study of Ambiguity Attitudes
- 2018
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Ingår i: Review of Economics and Statistics. - : MIT Press - Journals. - 0034-6535 .- 1530-9142. ; 100:4, s. 664-677
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Tidskriftsartikel (refereegranskat)abstract
- Ambiguity attitudes have been prominently used in economic models, but we still know little about their demographic correlates or their generalizability beyond the West. We analyze the ambiguity attitudes of almost 3,000 students across thirty countries. For gains, we find ambiguity aversion everywhere, while ambiguity aversion is much weaker for losses. Ambiguity attitudes change systematically with probabilities for both gains and losses. Much of the between-country variation can be explained through a few macroeconomic characteristics. In contrast, we find massive unexplained variation at the individual level. We also find much unexplained heterogeneity in individual responses to different decision tasks.
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| 2. |
- Olivain, C, et al.
(författare)
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Colonization of tomato root by pathogenic and nonpathogenic Fusarium oxysporum strains inoculated together and separately into the soil
- 2006
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Ingår i: Applied and Environmental Microbiology. - 0099-2240 .- 1098-5336. ; 72:2, s. 1523-1531
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Tidskriftsartikel (refereegranskat)abstract
- In soil, fungal colonization of plant roots has been traditionally studied by indirect methods such as microbial isolation that do not enable direct observation of infection sites or of interactions between fungal pathogens and their antagonists. Confocal laser scanning microscopy was used to visualize the colonization of tomato roots in heat-treated soil and to observe the interactions between a nonpathogenic strain, Fo47, and a pathogenic strain, Fo18, inoculated onto tomato roots in soil. When inoculated separately, both fungi colonized the entire root surface, with the exception of the apical zone. When both strains were introduced together, they both colonized the root surface and were observed at the same locations. When Fo47 was introduced at a higher concentration than Fo18, it colonized much of the root surface, but hyphae of Fo18 could still be observed at the same location on the root. There was no exclusion of the pathogenic strain by the presence of the nonpathogenic strain. These results are not consistent with the hypothesis that specific infection sites exist on the root for Fusarium oxysporum and instead support the hypothesis that competition occurs for nutrients rather than for infection sites.
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