Role of chaos for the validity of statistical mechanics laws: diffusion and conduction

Several years after the pioneering work by Fermi Pasta and Ulam, fundamental questions about the link between dynamical and statistical properties remain still open in modern statistical mechanics. Particularly controversial is the role of deterministic chaos for the validity and consistency of statistical approaches. This contribution reexamines such a debated issue taking inspiration from the problem of diffusion and heat conduction in deterministic systems. Is microscopic chaos a necessary ingredient to observe such macroscopic phenomena?Comment: Latex, 27 pages, 10 eps-figures. Proceedings of the Conference "FPU 50 years since" Rome 7-8 May 200

Genome-Wide Association Study in BRCA1 Mutation Carriers Identifies Novel Loci Associated with Breast and Ovarian Cancer Risk

BRCA1-associated breast and ovarian cancer risks can be modified by common genetic variants. To identify further cancer risk-modifying loci, we performed a multi-stage GWAS of 11,705 BRCA1 carriers (of whom 5,920 were diagnosed with breast and 1,839 were diagnosed with ovarian cancer), with a further replication in an additional sample of 2,646 BRCA1 carriers. We identified a novel breast cancer risk modifier locus at 1q32 for BRCA1 carriers (rs2290854, P = 2.7×10-8, HR = 1.14, 95% CI: 1.09-1.20). In addition, we identified two novel ovarian cancer risk modifier loci: 17q21.31 (rs17631303, P = 1.4×10-8, HR = 1.27, 95% CI: 1.17-1.38) and 4q32.3 (rs4691139, P = 3.4×10-8, HR = 1.20, 95% CI: 1.17-1.38). The 4q32.3 locus was not associated with ovarian cancer risk in the general population or BRCA2 carriers, suggesting a BRCA1-specific associat

Comportamento e composi\ue7\ue3o de um grupo de Callithrix jacchus Erxleben (Primates, Callitrichidae) na mata de Dois Irm\ue3os, Recife, Pernambuco, Brasil

<abstract language="eng">The objective of this study was to determine the size and composition of a group of wild Callithrix jacchus Erxleben, 1777, a small neotropical primate from the North East Brazil. The study was carried out in Dois Irmãos Forest, Recife, Pernambuco, Brazil, in an area of 6ha where this social group of marmosets had its home range. A graded transects system was cut to provide the access and moving during the observation period. To provide an individual identification for the members of the marmosets group and to achieve the objective of this study, two captures were made, with a six month interval between them in a 50x50m² area at the nuclear range of the group's area. The animals were realeased after a maximum period of 24h after traping. We made, during the whole study period, direct observations of the social group which wasn't limited only to count and identification of the marmosets, but expanded in consideration on the ecology and behavior of the Callithrix jacchus group. The results show us that the size and composition of the study group was similar to others descriptions for the Callitrichidae. The group composition suffered a 30% "turnover" in a six month interval, and the adults particulary, had a big frequency of change. One pair of infants was seen in December 1986 - in the middle of the dry season - and another infant appeared in the study group in 1987, just after the end of the wet season. Some dietary items were fruits, leaf buds and also exudate from the trunks and branchs of some tree's species. Intergroup agonistic interactions were recorded during February 1987