The influence of tonality, tempo, and musical sophistication on the listener's time-duration estimates.

Music listening affects time perception, with previous studies suggesting that a variety of factors may influence this: musical, individual, and environmental. Two experiments investigated the effect of musical factors (tonality and musical tempo) and individual factors (a listener's level of musical sophistication) on subjective estimates of duration. Participants estimated the duration of different versions of newly composed instrumental music stimuli under retrospective and prospective conditions.

Cellular prion protein: from physiology to pathology.

The human cellular prion protein (PrP(C)) is a glycosylphosphatidylinositol (GPI) anchored membrane glycoprotein with two N-glycosylation sites at residues 181 and 197. This protein migrates in several bands by Western blot analysis (WB). Interestingly, PNGase F treatment of human brain homogenates prior to the WB, which is known to remove the N-glycosylations, unexpectedly gives rise to two dominant bands, which are now known as C-terminal (C1) and N-terminal (N1) fragments.

Follicular dendritic cells emerge from ubiquitous perivascular precursors.

The differentiation of follicular dendritic cells (FDC) is essential to the remarkable microanatomic plasticity of lymphoid follicles. Here we show that FDC arise from ubiquitous perivascular precursors (preFDC) expressing platelet-derived growth factor receptor β (PDGFRβ). PDGFRβ-Cre-driven reporter gene recombination resulted in FDC labeling, whereas conditional ablation of PDGFRβ(+)-derived cells abolished FDC, indicating that FDC originate from PDGFRβ(+) cells.

Unexpected tolerance of alpha-cleavage of the prion protein to sequence variations.

The cellular form of the prion protein, PrP(C), undergoes extensive proteolysis at the alpha site (109K [see text]H110). Expression of non-cleavable PrP(C) mutants in transgenic mice correlates with neurotoxicity, suggesting that alpha-cleavage is important for PrP(C) physiology. To gain insights into the mechanisms of alpha-cleavage, we generated a library of PrP(C) mutants with mutations in the region neighbouring the alpha-cleavage site.

The reinfection threshold regulates pathogen diversity: the case of influenza.

The awareness that pathogens can adapt and evolve over relatively short time-scales is changing our view of infectious disease epidemiology and control. Research on the transmission dynamics of antigenically diverse pathogens is progressing and there is increasing recognition for the need of new concepts and theories. Mathematical models have been developed considering the modelling unit in two extreme scales: either diversity is not explicitly represented or diversity is represented at the finest scale of single variants.