Even-odd alternation in mass spectrum of thymine and uracil clusters: Evidence of intracluster photodimerization

Multiphoton ionization of thymine and uracil clusters generated by a supersonic molecular beam gave rise to a remarkable alternation of mass spectral intensities between even- and odd-numbered clusters. Such alternation was observed in clusters of up to 30 molecules. Excitation to the two lowest electronically excited states seemed to be a strong prerequisite. In view of the well known photodimerization reaction of thymine and uracil in the bulk phase, it is proposed that such alternation in the mass spectral intensity resulted from formation of photodimer units within the cluster on intense UV irradiation. Several analogues of thymine with no known propensity for photodimerization in the bulk phase did not exhibit any sign of such alternation in the cluster mass spectrum. The intrinsic UV window for photodimerization, and hence photoinduced mammalian mutagenesis, was estimated to be approximately 210–280 nm, significantly narrower than the previously reported bulk values of 150–300 nm.

Tilted excitation implies odd periodic resonances

This work was supported by the Brazilian agencies FAPESP and CNPq. MSB also acknowledges the Engineering and Physical Sciences Research Council grant Ref. EP/I032606/1. GID thanks Felipe A. C. Pereira for fruitful discussions.

A nova família de distribuições odd log-logística: teoria e aplicações

Neste trabalho, foi proposta uma nova família de distribuições, a qual permite modelar dados de sobrevivência quando a função de risco tem formas unimodal e U (banheira). Ainda, foram consideradas as modificações das distribuições Weibull, Fréchet, half-normal generalizada, log-logística e lognormal. Tomando dados não-censurados e censurados, considerou-se os estimadores de máxima verossimilhança para o modelo proposto, a fim de verificar a flexibilidade da nova família. Além disso, um modelo de regressão locação-escala foi utilizado para verificar a influência de covariáveis nos tempos de sobrevida. Adicionalmente, conduziu-se uma análise de resíduos baseada nos resíduos deviance modificada. Estudos de simulação, utilizando-se de diferentes atribuições dos parâmetros, porcentagens de censura e tamanhos amostrais, foram conduzidos com o objetivo de verificar a distribuição empírica dos resíduos tipo martingale e deviance modificada. Para detectar observações influentes, foram utilizadas medidas de influência local, que são medidas de diagnóstico baseadas em pequenas perturbações nos dados ou no modelo proposto. Podem ocorrer situações em que a suposição de independência entre os tempos de falha e censura não seja válida. Assim, outro objetivo desse trabalho é considerar o mecanismo de censura informativa, baseado na verossimilhança marginal, considerando a distribuição log-odd log-logística Weibull na modelagem. Por fim, as metodologias descritas são aplicadas a conjuntos de dados reais.

A problem in form perception: odd shape detection.

"C00-2118-0027."

The programme : containing the arrangements for the demonstration in connection with laying the corner stone of the government buildings June 24, 1874, together with a full directory of the city lodges of the Masons, Odd Fellows, Knights of Pythias, and other societies.

Lawrence J. Gutter Collection of Chicagoana.

The Odd fellows' amulet: or, The principles of Odd fellowship defined ... With an address ...

added t.p. engraved.

Odd craft /

Mode of access: Internet.

Notes of an east coast naturalist : a series of observations made at odd times during a period of twenty-five years in the neighborhood of Great Yarmouth /

Advertisements: p. [1]-40 (last group).

The repository of wit and humor; comprising more than one thousand anecdotes, odd scraps, off-hand hits, and humorous sketches;

Mode of access: Internet.

The odd volume : a collection of odds and ends ; in prose and verse /

Part 1 printed in green ; pt. 2 printed in red.

The Gavel : a monthly periodical devoted to odd fellowship and general literature.

Description based on: vol. 2, no. 1, Sept. 1845; title from caption.

The Quarterly magazine of the Independent Order of Odd Fellows.

Title varies slightly.

The Odd fellow, or, The secret association, and Foraging Peter.

Mode of access: Internet.

Minutes, and other documents of the Grand committees of the Independent order of Odd fellows, connected with the Manchester unity, from January, 1814, to December, 1828, inclusive.

Preface signed: Isaac Hardman.

The Wit's miscellany, or A companion for the choice spirits; consisting of a great variety of odd and uncommon epigrams, facetious drolleries, whimsical mottos, merry tales, fables, &c. All calculated for the entertainment and diversion of good company, and to pass a winter-evening in mirth and good humour.

Latin and English.