Investigating the perception of soundscapes through acoustic scene simulation.

This paper introduces a new experimental protocol for studying mental representations of urban soundscapes through a simulation process. Subjects are asked to create a full soundscape by means of a dedicated software tool, coupled with a structured sound data set. This paradigm is used to characterize urban sound environment representations by analyzing the sound classes that were used to simulate the auditory scenes. A rating experiment of the soundscape pleasantness using a seven-point bipolar semantic scale is conducted to further refine the analysis of the simulated urban acoustic scenes. Results show that (1) a semantic characterization in terms of presence/absence of sound sources is an effective way to characterize urban soundscape pleasantness, and (2) acoustic pressure levels computed for specific sound sources better characterize the appraisal than the acoustic pressure level computed over the overall soundscape.

Genomic diversity of natural killer cell receptor genes in three populations.

We report the distribution of genes encoding 11 killer cell immunoglobulin-like receptors (KIR) and 2 CD94:NKG2 receptors, in 32 Caucasians, 67 Australian Aborigines and 59 Vietnamese. The inhibitory and the activating KIR genes were found at different frequency in the three populations. No correlation was found between the polymorphism of the KIR genes and the HLA specificities of the tested samples. The most significant KIR associations were 2DL2 with 2DS2; 2DL2 with 2DS3 and 3DL1 with 2DS4 in all three study groups. In Caucasians and Vietnamese 2DS2 was associated with 2DS3 and 2DS1with 3DS1. KIR 2DL1 was strongly associated with three other KIRs: 2DL3, 3DL1 and 2DS4 in Aborigines. The distribution of the KIR phenotypes was different in the three populations. The AA1 phenotype was frequent in Vietnamese (42.4%) and Caucasians (31.2%), but very rare in Aborigines (1.5%). In contrast, the BB7 phenotype was very common for Aborigines (22.4%) and was absent in the two other groups. Our data demonstrate that different associations and putative KIR haplotypes could be distinguished in different populations.