Self-Similarity in Random Collision Processes

Kinetics of collision processes with linear mixing rules are investigated analytically. The velocity distribution becomes self-similar in the long time limit and the similarity functions have algebraic or stretched exponential tails. The characteristic exponents are roots of transcendental equations and vary continuously with the mixing parameters. In the presence of conservation laws, the velocity distributions become universal.Comment: 4 pages, 4 figure

Effects of sleep deprivation on neural functioning: an integrative review

Sleep deprivation has a broad variety of effects on human performance and neural functioning that manifest themselves at different levels of description. On a macroscopic level, sleep deprivation mainly affects executive functions, especially in novel tasks. Macroscopic and mesoscopic effects of sleep deprivation on brain activity include reduced cortical responsiveness to incoming stimuli, reflecting reduced attention. On a microscopic level, sleep deprivation is associated with increased levels of adenosine, a neuromodulator that has a general inhibitory effect on neural activity. The inhibition of cholinergic nuclei appears particularly relevant, as the associated decrease in cortical acetylcholine seems to cause effects of sleep deprivation on macroscopic brain activity. In general, however, the relationships between the neural effects of sleep deprivation across observation scales are poorly understood and uncovering these relationships should be a primary target in future research

Pathways to teacher education for intercultural communicative competence: teachers’ perceptions

Intercultural and plurilingual encounters have become increasingly frequent due to Information and Communication Technologies (ICT) developments, mobility (real/ virtual) and migration. To face the challenges inherent in such encounters, the development of intercultural communicative competence (ICC) is crucial. ICC development may start in the home but should also be a commitment in school curricula, in particular in language classrooms. To facilitate this, language teachers require training in order to integrate the intercultural dimension into their professional practice. In such a context, we implemented a training programme entitled The Intercultural Teacher with an experimental group of language teachers from secondary schools in the Aveiro district (Portugal). In this article, we describe teachers’ social perceptions of ICC and explore the following questions: (a) what does ICC mean for language teachers?; and (b) what are teachers’ views on the development of ICC? The findings of this analysis enabled us, firstly, to design a heuristic model of ICC, based on teachers’ views and perceptions. We were then able to identify some pathways for developing ICC through teacher education, which were validated by teachers themselves

Assessing associations between the AURKAHMMR-TPX2-TUBG1 functional module and breast cancer risk in BRCA1/2 mutation carriers

While interplay between BRCA1 and AURKA-RHAMM-TPX2-TUBG1 regulates mammary epithelial polarization, common genetic variation in HMMR (gene product RHAMM) may be associated with risk of breast cancer in BRCA1 mutation carriers. Following on these observations, we further assessed the link between the AURKA-HMMR-TPX2-TUBG1 functional module and risk of breast cancer in BRCA1 or BRCA2 mutation carriers. Forty-one single nucleotide polymorphisms (SNPs) were genotyped in 15,252 BRCA1 and 8,211 BRCA2 mutation carriers and subsequently analyzed using a retrospective likelihood appr