Dynamical Jahn-Teller Effect and Berry Phase in Positively Charged Fullerene I. Basic Considerations

We study the Jahn-Teller effect of positive fullerene ions $^2$C$_{60}^{+}$ and $^1$C$_{60}^{2+}$. The aim is to discover if this case, in analogy with the negative ion, possesses a Berry phase or not, and what are the consequences on dynamical Jahn-Teller quantization. Working in the linear and spherical approximation, we find no Berry phase in $^1$C$_{60}^{2+}$, and presence/absence of Berry phase for coupling of one $L=2$ hole to an $L=4$/$L=2$ vibration. We study in particular the special equal-coupling case ($g_2=g_4$), which is reduced to the motion of a particle on a 5-dimensional sphere. In the icosahedral molecule, the final outcome assesses the presence/absence of a Berry phase of $\pi$ for the $h_u$ hole coupled to $G_g$/$H_h$ vibrations. Some qualitative consequences on ground-state symmetry, low-lying excitations, and electron emission from C$_{60}$ are spelled out.Comment: 31 pages (RevTeX), 3 Postscript figures (uuencoded

Female chromosome X mosaicism is age-related and preferentially affects the inactivated X chromosome

To investigate large structural clonal mosaicism of chromosome X, we analysed the SNP microarray intensity data of 38,303 women from cancer genome-wide association studies (20,878 cases and 17,425 controls) and detected 124 mosaic X events42Mb in 97 (0.25%) women. Here we show rates for X-chromosome mosaicism are four times higher than mean autosomal rates; X mosaic events more often include the entire chromosome and participants with X events more likely harbour autosomal mosaic events. X mosaicism frequency increases with age (0.11% in 50-year olds; 0.45% in 75-year olds), as reported for Y and autosomes. Methylation array analyses of 33 women with X mosaicism indicate events preferentially involve the inactive X chromosome. Our results provide further evidence that the sex chromosomes undergo mosaic events more frequently than autosomes, which could have implications for understanding the underlying mechanisms of mosaic events and their possible contribution to risk for chronic diseases

Caracterização morfológica de germoplasma de alho por análises multivariada componentes principais e variáveis canônicas Morphological characterisation of garlic germplasm by cluster, principal components and canonic variables analysis

O Banco Ativo de Germoplasma (BAG) de alho, mantido pela Embrapa Hortaliças, possui 89 acessos representativos da diversidade genética da cultura no país. A presença de genótipos duplicados na coleção onera os custos de manutenção e dificulta a avaliação agronômica dos materiais. A identificação de duplicatas no BAG de alho foi feita com a utilização de 27 variáveis de caracteres morfológicos. Essa metodologia possibilitou a diferenciação de treze grupos de genótipos através de análise multivariada. As variáveis que mais contribuíram para a distinção morfológica dos grupos através de análise de componentes principais foram: altura de plantas com folhas levantadas aos 60 dias; altura de plantas com folhas normais aos 60 dias; ângulo de inserção de folhas aos 90 dias; cor dos bulbos; número de bulbilhos de peneiras um, dois e quatro; peso de bulbilhos da peneira dois; peso médio de bulbos na colheita e peso médio de bulbos na debulha. Os parâmetros mais importantes na distinção de representantes de grupos de genótipos, na análise de variáveis canônicas foram: altura de plantas com folhas levantadas aos 120 dias e altura de plantas com folhas normais aos 60 dias; ângulo de inserção de folhas aos 90 dias; número de folhas aos 60 e aos 90 dias; número de bulbos na colheita; número total de bulbos; peso médio de plantas no primeiro dia e aos 60 dias da colheita e peso médio total de bulbos. Os genótipos representativos de diferentes grupos foram distintamente caracterizados com base em 34 parâmetros, complementados pela análise de variáveis canônicas.<br>The garlic Germplasm Collection maintained by Embrapa Hortaliças comprises 89 accessions, representing the genetic diversity of this crop in the country. Duplicates of the same genotype increase the cost of maintaining the collection, as well as make difficult their agronomic evaluation. The identification of duplicated accessions of the garlic Germoplasm Active Bank was obtained through analysis of 27 variables of morphological characteristics. Genotypic differentiation among thirteen groups was achieved by cluster analysis. The most important features for distinction of these groups through principal components analysis were: plant height with erect leaves at 60 days; plant height with normal leaves at 60 days; leaf insertion angle at 90 days; bulb colour; number of bulblets from sieves one, two, and four; weight of bulblets from sieve two; average weight of bulbs at harvest time; and average bulb weight at threshing time. The most important features for the distinction of group genotype representatives by canonic variables analysis were: plant height with erect leaves at 120 days; plant height with normal leaves at 60 days; leaf insertion angle at 90 days; number of leaves at 60 and 90 days; number of bulbs at harvest time; total number of bulbs; average weight of plants at first day and at 60 days; and average weight of bulbs. Genotype representatives of different groups were distinctly characterised on the basis of 34 parameters, complemented by canonic variables analysis