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Université de Fribourg

Amino acids in iron oxide mineralization: (incomplete) crystal phase selection is achieved even with single amino acids

Mantion, Alexandre ; Gozzo, Fabia ; Schmitt, Bernd ; Stern, Willem B. ; Gerber, Yvonne ; Robin, Adeline Y. ; Fromm, Katharina M. ; Painsi, Monika ; Taubert, Andreas

In: The Journal of Physical Chemistry C, 2008, vol. 112, no. 32, p. 12104–12110

Iron oxides are important minerals in biology and materials science. Using biomimetic synthesis, a variety of iron oxides have been fabricated. However, it is still not clear how growth modifiers like amino acids and peptides select different crystal phases of a complex material like iron oxide. The current paper shows that already with single amino acids, (incomplete) crystal phase selection is...

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