Finding extraterrestrial life using ground-based high-resolution spectroscopy

Exoplanet observations promise one day to unveil the presence of extraterrestrial life. Atmospheric compounds in strong chemical disequilibrium would point to large-scale biological activity just as oxygen and methane do in the Earth's atmosphere. The cancellation of both the Terrestrial Planet Finder and Darwin missions means that it is unlikely that a dedicated space telescope to search for biomarker gases in exoplanet atmospheres will be launched within the next 25 years. Here we show that ground-based telescopes provide a strong alternative for finding biomarkers in exoplanet atmospheres through transit observations. Recent results on hot Jupiters show the enormous potential of high-dispersion spectroscopy to separate the extraterrestrial and telluric signals making use of the Doppler shift of the planet. The transmission signal of oxygen from an Earth-twin orbiting a small red dwarf star is only a factor 3 smaller than that of carbon monoxide recently detected in the hot Jupiter tau Bootis b, albeit such a star will be orders of magnitude fainter. We show that if Earth-like planets are common, the planned extremely large telescopes can detect oxygen within a few dozen transits. Ultimately, large arrays of dedicated flux collector telescopes equipped with high-dispersion spectrographs can provide the large collecting area needed to perform a statistical study of life-bearing planets in the solar neighborhood.Comment: 22 pages, 3 figures; published in Ap

Appellate Review of Legal but Excessive Sentences: A Comparative Study

Classical penology was conceived in France in the eighteenth century, and then eclipsed all over the world in the nineteenth, when Lombroso conjured up the picture of the born criminal. It was finally laid to rest in the United States in the twentieth century. Its basic tenet had been simple enough: the legislature in its infinite wisdom would seek and find the appropriate punishment for every crime.This can be accomplished if a crime is defined narrowly enough, perhaps by the creation of subcategories of that crime, so as to encompass all potential perpetrators who will each incur the same amount of criminal guilt. All perpetrators in the same subcategory are then entitled to the exact same amount of punishment in expiation of their criminal guilt. This system, so it was thought, ideally adjusts the punishment to achieve a balance between the crime and its harm and the criminal and his guilt, without going into undue subtleties of minute variations in the guilt of perpetrators in the same sub-category. Consequently the codes of the eighteenth and nineteenth centuries could satisfy themselves with defining and categorizing crimes in terms of the harm created and the specific mens rea inquestion

Modelação da circulação induzida por ondas na zona de arrebentação /

Dissertação (Mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico.É apresenta uma metodologia para determinar as correntes induzidas por ondas curtas (i.e. geradas pelo vento) na zona de arrebentação através de modelagem numérica, considerando o caso mais simples que é o da circulação(permanente) induzida por ondas monocromáticas. A modelagem foi organizada em três módulos: i)Cálculo do campo de ondas utilizando um modelo de refração-difração baseado na Aproximação Parabólica da Equação do Declive Suave (Kirby,1986); ii)Cálculo do campo de forças induzido pelas ondas na massa d'água a partir dos gradientes de tensão de radiação (Longuet-Higgins, 1970a, b); iii)Cálculo das correntes (médias na coluna d'água e no período) e da elevação (média) da superfície resultantes da ação do campo de forças determinado no item (ii) através de um modelo de circulação 2D-H (Martins,1992). Para testar a metodologia e avaliar a qualidade dos resultados comparou-se os dados de um experimento de laboratório realizado no Laboratoire d'Hidraulique de France-LHF no qual ondas monocromáticas incidem perpendicularmente sobre um quebra-mar localizado numa praia plana e uniforme, e que contemplou medições detalhadas dos parâmetros de interesse. Os resultados obtidos pela presente metodologia reproduziram de forma satisfatória as medições de laboratório bem aqueles apresentados por outros modelos

The stability paradox : why expansion of education for women has not delayed age at first union or childbearing in Latin America

Despite substantial improvements in women's education, the age atwhich Latin American women marry (cohabit) or become mothers for the first time has barely decreased over the past four decades. We refer to this as the "stability paradox." We examine the relationship between years of schooling and transitions to first union or child, analyzing retrospective information from 50 cohorts of women born between 1940 and 1989 in 12 Latin American countries. Absolute and relative measures of schooling are compared. Data is drawn from 38 Demographic Health Surveys (DHS) conducted between 1986 and 2012 in these countries. Results show that expected postponement in family transitions due to educational expansion was offset by a rise in union formation and childbearing within strata of absolute education, but stayed approximately constant within strata of relative education. The relative measure of education retains the stratifying power of education but neutralizes any effect attached to a specific number of years of schooling and the learning skills associated with them. This is consistent with the idea that access to education in Latin America reproduces existing patterns of socioeconomic advantage, rather than creating a more equitable distribution of learning opportunities and outcomes

Information measures based on Tsallis' entropy and geometric considerations for thermodynamic systems

An analysis of the thermodynamic behavior of quantum systems can be performed from a geometrical perspective investigating the structure of the state space. We have developed such an analysis for nonextensive thermostatistical frameworks, making use of the q-divergence derived from Tsallis' entropy. Generalized expressions for operator variance and covariance are considered, in terms of which the fundamental tensor is given.Comment: contribution to 3rd NEXT-SigmaPhi International Conference (August 2005, Kolymbari, Greece

First Order Vortex Dynamics

A non-dissipative model for vortex motion in thin superconductors is considered. The Lagrangian is a Galilean invariant version of the Ginzburg--Landau model for time-dependent fields, with kinetic terms linear in the first time derivatives of the fields. It is shown how, for certain values of the coupling constants, the field dynamics can be reduced to first order differential equations for the vortex positions. Two vortices circle around one another at constant speed and separation in this model.Comment: 22pages, no figures, tex fil

Keratinocytes Play a Role in Regulating Distribution Patterns of Recipient Melanosomes In Vitro

Melanosomes in keratinocytes of Black skin are larger and distributed individually whereas those within keratinocytes of Caucasian skin are smaller and distributed in clusters. This disparity contributes to differences in skin pigmentation and photoprotection, but the control of these innate distribution patterns is poorly understood. To investigate this process, cocultures were established using melanocytes and keratinocytes derived from different racial backgrounds and were examined by electron microscopy. Melanosomes transferred to keratinocytes were categorized as individual or in various clusters. Melanosome size was also determined for individual and clustered melanosomes. Results indicate that, in our model system, melanosomes in keratinocytes from different racial backgrounds show a combination of clustered and individual melanosomes. When keratinocytes from dark skin were cocultured with melanocytes from (i) dark skin or (ii) light skin, however, recipient melanosomes were individual versus clustered in (i) 77% vs 23% and (ii) 64% vs 36%, respectively. In contrast, when keratinocytes from light skin were cocultured with melanocytes from (iii) dark skin or (iv) light skin, recipient melanosomes were individual versus clustered in (iii) 34% vs 66% and (iv) 39% vs 61%, respectively. These results indicate that recipient melanosomes, regardless of origin, are predominantly distributed individually by keratinocytes from dark skin, and in membrane-bound clusters by those from light skin. There were also differences in melanosome size from dark or light donor melanocytes. Melanosome size was not related to whether the melanosomes were distributed individually or clustered, however, in cocultures. These results suggest that regulatory factor(s) within the keratinocyte determine recipient melanosome distribution patterns