Explanation of the intriguing quantum phenomenon of the off-resonant cavity mode emission

We theoretically investigate the unexpected occurrence of an extra emission peak that has been experimentally observed in off-resonant studies of cavity QED systems. Our results within the Markovian master equation approach successfully explain why the central peak arises, and how it reveals that the system is suffering a dynamical phase transition induced by the phonon-mediated coupling. Our findings are in perfect agreement with previous reported experimental results and for the first time the fundamental physics behind this quantum phenomenon is understood

Population trends and priority conservation sites for Mexican Duck Anas diazi

Little is known about Mexican Duck Anas diazi biology and populations. We analyse long-term (1960–2000) trends of Mexican Duck numbers in Mexico and employ contemporary count data (1991–2000) from the U.S. Fish and Wildlife Service midwinter surveys to identify key sites for conservation using a complementarity approach. The overall Mexican Duck population showed a significant long-term increase of 2.5% per year, with large fluctuations throughout the study period. The Northern highlands population increased at an annual rate of 7.7%, while the Central highlands population showed no significant long-term trend. During the last decade, counts in both the Northern and Central highlands exhibited no significant change. At the site level, significant long-term increases occurred in four localities in the Northern highlands (Laguna Babícora +13.9% annually, Laguna Bustillos +25.9%, Laguna Mexicanos +20.4% and Laguna Santiaguillo +16.9%) and in three localities in the Central highlands (Languillo +15.3% annually, Presa Solís +8.9%, Zacapu +13.4%). Two sites in the Central highlands showed significant declines, in the long term (Lago de Chapala, -5.2% per year) and during the last decade (Lerma, -11.8% per year). The Northern highlands held 16% and the Central highlands 84% of the Mexican Duck population in the period 1960–2000; during the last decade, these figures were 31% and 69%, respectively. A set of priority sites for conservation of the Mexican Duck was identified, consisting of 15 sites holding more than 70% of the midwinter Mexican Duck counts in Mexico. Ten sites from the priority set also qualify for designation as wetlands of international importance under the Ramsar Convention on Wetlands, by holding [greater-than-or-equal] 1% of the estimated population. Four of the priority sites are in the Northern highlands and 11 in the Central highlands, of which eight are distributed along the Rio Lerma drainage. The most urgent actions that need to be undertaken are to estimate the current minimum population size in Mexico; to establish a programme for monitoring populations in the priority sites, especially those located within the highly degraded Rio Lerma drainage; and to determine the most feasible management actions for the species, concentrating efforts around the priority sites

Diversificación de las estructuras familiares: Caracterización de las convivencias en Chile

As part of the debate about different types of families in modern societies, this article aims to describe relationships through the analysis of survey data from Casen 2006, which is the latest and most comprehensive source that can inquire into this aspect at the national level. In general, in recent years it is possible to establish an increase of “premarital relations” at the expense of formal unions and an extension of such form of union in other social groups to the traditionally observed –impoverished sectors–. Furthermore, the research explores how socio-demographic variables (age, years of schooling, quintile, urban or rural area and activity status) affect the probability of establishing premarital relationships on a sex-differentiated way.Enmarcado en el debate acerca de las distintas modalidades de familias en las sociedades contemporáneas, el presente artículo busca caracterizar las convivencias a partir de un análisis de los datos de la encuesta Casen 2006, que es la fuente más reciente y completa que permite indagar en dicho aspecto a nivel nacional. En términos generales, es posible establecer un aumento de las convivencias en desmedro de las uniones formales en los últimos años y una ampliación de dicha modalidad de unión en otros grupos sociales a los tradicionalmente observados –sectores más empobrecidos–. Asimismo, en el trabajo exploramos en algunas variables (edad, años de escolaridad, quintil, zona urbana o rural y condición de actividad) que inciden en la probabilidad de establecer la convivencia, de manera diferenciada por sexo

Optimizing the design of timber components under decay and climate variations

International audienceThe durability of timber structures can be affected by the isolated or combined actions of loading, moisture content, temperature, biological activity, etc. This work focuses on the optimal design of new timber structures subjected to deterioration. Since the deterioration processes and the structural behavior of timber structures are complex, nowadays the deterioration models are not able to account for all influencing factors. Consequently, this study is based on an empirical model that was derived based in-lab experimental studies for the decay growth of brown rot in pine sapwood under variant climate conditions. Such a model is divided into two processes: (i) activation process and (ii) mass loss process. On the other hand, there are significant uncertainties involved in the problem. The uncertainties inherent to materials properties, models and climate are considered throughout a time-dependent reliability based-design optimization (TD-RBDO) approach. The TD-RBDO aims to ensure a target reliability level during the operational life. This approach is applied to design optimization of a new timber component subjected to different French climates. The performance of the optimized solution is compared with a traditional cross-section designed according to the Eurocode 5 in terms of safety. The overall results indicate that an optimized solution ensures a target reliability level during the whole structural lifetime