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Université de Fribourg

Influence of connector groups on the interactions of substituents with carbon-centered radicals

Menon, Ambili S. ; Bally, Thomas ; Radom, Leo

In: The Journal of Physical Chemistry, 2012, vol. 116, no. 41, p. 10203–10208

High-level G3X(MP2)-RAD calculations have been carried out to examine the effect of interposing a “connector” group (W) on the interaction between a substituent (X) and the radical center in carbon-centered radicals (•CH₂–W–X). The connector groups include −CH₂–, −CH═CH–, −C≡C–, −p-C₆H₄–, −m-C₆H₄–, and −o-C₆H₄–,...

Université de Fribourg

Animal équivoque. De Lincoln à Paris via Cologne

König-Pralong, Catherine

In: Mots médiévaux offerts à Ruedi Imbach, 2011, p. 67-76

Université de Fribourg

Pathogen-Related Yeast (PRY) proteins and members of the CAP superfamily are secreted sterol-binding proteins

Choudhary, Vineet ; Schneiter, Roger

In: Proceedings of the National Academy of Sciences of the United States of America - PNAS, 2012, vol. 109, no. 42, p. 16882-16887

Sterols and related membrane-perturbing agents are subject to a quality control cycle. Compounds that fail to pass this control are acetylated and secreted into the culture media, whereas lipids that pass the cycle are deacetylated and retained within the cell. Here we describe the identification of a family of conserved proteins, the Pathogen-Related Yeast (PRY) proteins, as a class of...

Université de Fribourg

Synchronizing nuclear import of ribosomal proteins with ribosome assembly

Kressler, Dieter ; Bange, Gert ; Ogawa, Yutaka ; Stjepanovic, Goran ; Bradatsch, Bettina ; Pratte, Dagmar ; Amlacher, Stefan ; Strauß, Daniela ; Yoneda, Yoshihiro ; Katahira, Jun ; Sinning, Irmgard ; Hurt, Ed

In: Science, 2012, vol. 338, no. 6107, p. 666-671

Ribosomal proteins are synthesized in the cytoplasm, before nuclear import and assembly with ribosomal RNA (rRNA). Little is known about coordination of nucleocytoplasmic transport with ribosome assembly. Here, we identify a transport adaptor, symportin 1 (Syo1), that facilitates synchronized coimport of the two 5S-rRNA binding proteins Rpl5 and Rpl11. In vitro studies revealed that Syo1...

Université de Fribourg

The serotonergic central nervous system of the drosophila larva: anatomy and behavioral function

Huser, Annina ; Rohwedder, Astrid ; Apostolopoulou, Anthi A. ; Widmann, Annekathrin ; Pfitzenmaier, Johanna E. R. ; Maiolo, Elena M. ; Selcho, Mareike ; Pauls, Dennis ; Essen, Alina von ; Gupta, Tripti ; Sprecher, Simon G. ; Birman, Serge ; Riemensperger, Thomas ; Stocker, Reinhard F. ; Thum, Andreas S.

In: PLoS ONE, 2012, vol. 7, no. 10, p. e47518

The Drosophila larva has turned into a particularly simple model system for studying the neuronal basis of innate behaviors and higher brain functions. Neuronal networks involved in olfaction, gustation, vision and learning and memory have been described during the last decade, often up to the single-cell level. Thus, most of these sensory networks are substantially defined, from the sensory...

Université de Fribourg

Succession in the aquatic Sarracenia purpurea community : deterministic or driven by contingency?

Gray, Sarah M.

In: Aquatic Ecology, 2012, vol. 46, no. 4, p. 487-499

The development of a community through time, or succession, is generally described as the orderly replacement of species until a deterministic, stable endpoint is reached. However, stochastic factors, coupled with intrinsic biotic factors, such as herbivory or predation, can cause communities within the same habitat to become highly dissimilar in composition. Much research on the succession of...

Université de Fribourg

A novel pathway of ceramide metabolism in Saccharomyces cerevisiae

Voynova, Natalia S. ; Vionnet, Christine ; Ejsing, Christer S. ; Conzelmann, Andreas

In: Biochemical Journal, 2012, vol. 447, p. 103–114

The hydrolysis of ceramides in yeast is catalysed by the alkaline ceramidases Ypc1p and Ydc1p, two highly homologous membrane proteins localized to the ER (endoplasmic reticulum). As observed with many enzymes, Ypc1p can also catalyse the reverse reaction, i.e. condense a non-esterified fatty acid with PHS (phytosphingosine) or DHS (dihydrosphingosine) and thus synthesize ceramides. When...

Université de Fribourg

Hybrid recommendation algorithm based on two roles of social tags

Zhang, Zi-Ke ; Liu, Chuang

In: International Journal of Bifurcation and Chaos, 2012, vol. 22, no. 07, p. 1250166

The past few years have witnessed the great success of a new family of paradigms, social tagging networks, which allows users to freely associate social tags to items and efficiently manage them. Thus it provides us a promising way to effectively find useful and interesting information. In this paper, we consider two typical roles of social tags: (i) an accessorial tool helping users organize...

Université de Fribourg

Uncovering missing links with cold ends

Zhu, Yu-Xiao ; Lü, Linyuan ; Zhang, Qian-Ming ; Zhou, Tao

In: Physica A: Statistical Mechanics and its Applications, 2012, vol. 139, no. 22, p. 5769–5778

To evaluate the performance of prediction of missing links, the known data are randomly divided into two parts, the training set and the probe set. We argue that this straightforward and standard method may lead to terrible bias, since in real biological and information networks, missing links are more likely to be links connecting low-degree nodes. We therefore study how to uncover missing links...