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Université de Fribourg

Absolute cross sections for dissociative electron attachment to HCl, HBr, and their deuterated analogs

Fedor, Juraj ; May, Olivier ; Allan, Michael

In: Physical Review A, 2008, vol. 78, p. 032701

We have measured absolute dissociative electron attachment cross sections for HX and DX (X=Cl and Br) using a trochoidal electron spectrometer equipped with a total ion collection collision chamber, operated both in a field-free passive ion collection mode, and an active ion collection mode, with an extracting electric field. Our results for Br⁻ from HBr are in an excellent...

Université de Fribourg

Life-history variation in contrasting habitats: flowering decisions in a clonal perennial herb (Veratrum album)

Hesse, Elze ; Rees, Mark ; Müller-Schärer, Heinz

In: The American Naturalist, 2008, vol. 172, no. 5, p. E196–E213

Quantifying intraspecific demographic variation provides a powerful tool for exploring the diversity and evolution of life histories. We investigate how habitat-specific demographic variation and the production of multiple offspring types affect the population dynamics and evolution of delayed reproduction in a clonal perennial herb with monocarpic ramets (white hellebore). In this species,...

Université de Fribourg

Differential effects of flower feeding in an insect host–parasitoid system

Kehrli, Patrik ; Bacher, Sven

In: Basic and Applied Ecology, 2008, vol. 9, no. 6, p. 709-717

In many insect host–parasitoid systems, both the host and its parasitoids forage on shared floral resources. As a result of insect behaviour, morphology and physiology, flower species may act selectively at different levels of such systems, e.g., between the trophic levels of hosts and parasitoids, between species within a guild, between sexes or individuals within a species or between life...

Université de Fribourg

Marktzugang in der EU und in der Schweiz : Rechtsquellen, Tragweite der Grundfreiheiten und des Personenfreizügigkeitsabkommens

Epiney, Astrid ; Gammenthaler, Nina

In: Marktzugang in der EU und in der Schweiz. Zur grenzüberschreitenden Mobilität von Personen und Unternehmen im EU-Recht und dem Personenfreizügigkeitsabkommen, 2008, p. 1-44