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Université de Fribourg

Variation in phenology, growth, and wood anatomy of Toona sinensis and Toona ciliata in relation to different environmental conditions

Heinrich, Ingo ; Banks, John Charles Gripper

In: International Journal of Plant Sciences, 2006, vol. 167, no. 4, p. 831-841

Tree-ring proxy data from subtropical to tropical Australasia are valuable though rare sources for climate reconstructions. Toona sinensis (A. Juss.) M. Roem. and Toona ciliata M. Roem. occurring naturally in this region are among the most promising tree species for future tree-ring research. However, little is known about their phenological behaviors and the influence of...

Université de Fribourg

Tree-ring anomalies in Toona ciliata

Heinrich, Ingo ; Banks, John Charles Gripper

In: IAWA Journal, 2006, vol. 27, no. 2, p. 213–231

New increment core samples of Toona ciliata collected in the Australian tropics and subtropics compared to already existing material from the Upper Kangaroo Valley, near Sydney exhibit distinct differences in tree-ring structures. This necessitated a closer examination of the wood anatomy, possible false rings and the species’ crossdating capacity in northeast Australia. During tree-ring...

Université de Fribourg

Sédimentologie, paléontologie et paléoenvironnements côtiers de la région de Porrentruy (Sud-Rhénan, Paléogène, Jura, Suisse): implications géodynamiques

Picot, Laurent ; Becker, Damien ; Lapaire, Frédéric ; Ustaszewski, Kamil ; Hug, Wolfgang A. ; Berger, Jean-Pierre

In: Eclogae Geologicae Helvetiae, 2005, vol. 98, no. 2, p. 281-296

Situés dans la partie la plus distale du bassin molassique suisse et dans le prolongement sud du fossé rhénan, les dépôts conglomératiques appartenant au groupe stratigraphique des Gompholithes & Conglomérats ont fait l’objet d’une étude sédimentologique et paléontologique détaillée. La multitude des affleurements réalisés lors des travaux de construction de l’autoroute...

Université de Fribourg

Energy gradients with respect to atomic positions and cell parameters for the Kohn-Sham density-functional theory at the Γ point

Weber, Valéry ; Tymczak, Christopher J. ; Callacombe, Matt

In: The Journal of Chemical Physics, 2006, vol. 124, p. 224107

The application of theoretical methods based on density-functional theory is known to provide atomic and cell parameters in very good agreement with experimental values. Recently, construction of the exact Hartree-Fock exchange gradients with respect to atomic positions and cell parameters within the Γ-point approximation has been introduced [V. Weber et al., J. Chem. Phys. 124, 214105...

Université de Fribourg

Synthesis of an unsymmetrically substituted, dithienylethene-containing 1,10-phenanthroline ligand and its ruthenium(ii) complex

Kühni, Joël ; Adamo, Vincent ; Belser, Peter

In: Synthesis, 2006, vol. 12, p. 1946-1948

The synthesis of an unsymmetrically substituted 1,10-phenanthroline ligand and its corresponding ruthenium(II) complex is reported. Suzuki coupling has been employed under different conditions to get the target ligand.

Université de Fribourg

Exchange energy gradients with respect to atomic positions and cell parameters within the Hartree-Fock Γ-point approximation

Weber, Valéry ; Daul, Claude A. ; Challacombe, Matt

In: The Journal of Chemical Physics, 2006, vol. 124, p. 214105

Recently, linear scaling construction of the periodic exact Hartree-Fock exchange matrix within the Γ-point approximation has been introduced [J. Chem. Phys. 122, 124105 (2005)]. In this article, a formalism for evaluation of analytical Hartree-Fock exchange energy gradients with respect to atomic positions and cell parameters at the Γ-point approximation is presented. While the...

Université de Fribourg

Photochromic switches incorporated in bridging ligands: a new tool to modulate energy-transfer

Belser, Peter ; Cola, Luisa De ; Hartl, F. ; Adamo, Vincenzo ; Bozic, Biljana ; Chriqui, Yoel ; Iyer, Vijay Mahadevan ; Jukes, R. T. F. ; Kühni, Joel ; Querol, Manel ; Roma, Silvia ; Salluce, Nunzio

In: Advanced Functional Materials, 2006, vol. 16, no. 2, p. 195-208

The thoughful construction of molecular switches has led to a gamut of supramolecular systems that can be used in molecular electronics. These include molecules based on thienylethenes, spiropyrans, fulgides, dithienylphenanthrolines, and diazafluorenes. This article reviews the recent developments made in the synthesis and characterization of all these systems, thereby allowing a comparative...

Université de Fribourg

Synthesis and structural analysis of palladium biscarbene complexes derived from bisimidazolium ligand precursors

Heckenroth, Marion ; Neels, Antonia ; Stoeckli-Evans, Helen ; Albrecht, Martin

In: Inorganica Chimica Acta, 2006, vol. 359, no. 6, p. 1929-1938

The palladation of potentially chelating bisimidazolium ligand precursors with palladium acetate gives bridging bimetallic, chelating monometallic, and homoleptic tetracarbene complexes. The coordination mode of the biscarbene ligand has been identified by spectroscopic analysis and crystallographic characterization of representative complexes, including the first example of a biscarbene A-frame...

Université de Fribourg

Catalytically active palladium pyridylidene complexes: pyridinium ionic liquids as N-heterocyclic carbene precursors

Albrecht, Martin ; Stoeckli-Evans, Helen

Pyridinium salts similar to those used as ionic liquid solvents readily undergo palladation in the presence of a base, thus giving palladium-pyridylidene N-heterocyclic carbene complexes that are active catalysts for Suzuki-type cross-coupling reactions.

Université de Fribourg

Ablation of the single dynamin of T. brucei blocks mitochondrial fission and endocytosis and leads to a precise cytokinesis arrest

Chanez, Anne-Laure ; Hehl, Adrian B. ; Engstler, Markus ; Schneider, André

In: Journal of Cell Science, 2006, vol. 119, p. 2968-2974

Mitochondrial fission is mediated by dynamin-like proteins (DLPs). Trypanosoma brucei contains a single DLP, which is the only member of the dynamin superfamily. We have previously shown that expression of the human proapoptotic Bax in T. brucei induces extensive mitochondrial fragmentation. Here we report that Baxinduced mitochondrial fission is abolished in cell lines lacking...