Superconductivity in the SU(N) Anderson Lattice at U=\infty

We present a mean-field study of superconductivity in a generalized N-channel cubic Anderson lattice at U=\infty taking into account the effect of a nearest-neighbor attraction J. The condition U=\infty is implemented within the slave-boson formalism considering the slave bosons to be condensed. We consider the $f$-level occupancy ranging from the mixed valence regime to the Kondo limit and study the dependence of the critical temperature on the various model parameters for each of three possible Cooper pairing symmetries (extended s, d-wave and p-wave pairing) and find interesting crossovers. It is found that the d- and p- wave order parameters have, in general, very similar critical temperatures. The extended s-wave pairing seems to be relatively more stable for electronic densities per channel close to one and for large values of the superconducting interaction J.Comment: Seven Figures; one appendix. Accepted for publication in Phys. Rev.

A case-only study to identify genetic modifiers of breast cancer risk for BRCA1/BRCA2 mutation carriers

Breast cancer (BC) risk for BRCA1 and BRCA2 mutation carriers varies by genetic and familial factors. About 50 common variants have been shown to modify BC risk for mutation carriers. All but three, were identified in general population studies. Other mutation carrier-specific susceptibility variants may exist but studies of mutation carriers have so far been underpowered. We conduct a novel case-only genome-wide association study comparing genotype frequencies between 60,212 general population BC cases and 13,007 cases with BRCA1 or BRCA2 mutations. We identify robust novel associations for 2 variants with BC for BRCA1 and 3 for BRCA2 mutation carriers, P < 10−8, at 5 loci, which are not associated with risk in the general population. They include rs60882887 at 11p11.2 where MADD, SP11 and EIF1, genes previously implicated in BC biology, are predicted as potential targets. These findings will contribute towards customising BC polygenic risk scores for BRCA1 and BRCA2 mutation carriers

Mortalidade feminina no Brasil: sexo frágil ou sexo forte?

A população feminina brasileira tem chegado à velhice de maneira mais significativa que a masculina. Este fenômeno tem sido também observado em países industrializados centrais onde é freqüente a sobremortalidade masculina. A análise dos diferenciais por causas específicas pode ajudar a compreender os determinantes do padrão brasileiro e a antecipar algumas tendências futuras, especialmente tendo-se em conta as profundas mudanças no papel social da mulher em nossa realidade. Assim, foi feito estudo de mortalidade em dez capitais brasileiras, em 1985, com taxas geral e específicas por cinco principais grupos de causas segundo sexo e padronizadas por idade pelo método direto. Como medida dos diferenciais, usou-se razões e diferenças entre os sexos. Os resultados revelam que o perfil regional relaciona-se ao padrão de urbanização e industrialização, com os maiores diferenciais por sexo nas capitais mais desenvolvidas do país. A sobremortalidade masculina explica-se basicamente pela magnitude das causas externas e das doenças do aparelho circulatório, sendo peculiar a especial importância das mortes violentas, que são as principais responsáveis pelos diferenciais por sexo. Acredita-se que a atual tendência venha a se manter, embora a longo prazo as diferenças entre os sexos possam se reduzir. De qualquer modo, o prolongamento da vida, sem adequadas condições de subsistência, não parece estar significando exatamente uma vantagem para a mulher brasileira.<br>Population ageing in Brazil has been more rapid and more intense among women. This phenomenon is well described in developed countries where mortality rates are higher for men than women. In this regard, the analysis of mortality patterns by cause contributes to elucidate the determinant factors of the present situation in Brazil and provides indications of some future trends in female mortality. This is especially important due to the fact that in Brazil the social role of women has experienced great changes. This study presents data on mortality from ten capital cities in 1985, showing age-standardized overall and cause-specific mortality rates for five of the main groups of causes by sex. Ratios and differences effect estimators were used. The results revealed that regional patterns are associated with the urban and industrial processes with greater differences by sex in more developed regions. External causes and cardiovascular diseases are the main factors responsible for higher mortality among men with special emphasis on violent deaths. It is inferred that the present trend will be maintained, though it is possible that mortality differences by sex could decrease in the near future. The authors discuss that longer survival among women in Brazil does not reveal better life conditions