Thermoluminescence as a technique for determining the nature and history of small solar system particles

The thermoluminescence phenomenon has been used for pottery dating and radiation dosimetry for sixty years and for forty years has been applied to the study of meteorites, being successful in quantifying metamorphic histories and providing new insights into terrestrial age and orbits. Here we review some of the fundamental properties of thermoluminescence with particular focus on the study of small extraterrestrial particles. We suggest that natural TL data can be used to identify the burial and release history of cometary particles and that induced TL measurements can provide in-sights into the mineralogy of particles (even when largely amorphous) and the metamorphic history of those particles. We illustrate the use of TL to study small particles by describing recent studies on micrometeorites and 10–100 μm fragments taken from the matrix of a meteorite Semarkona which is type 3.0 ordinary chondrite.     

Freedom Isn't Free: Free Will in La vida es sueño Revisited

This article analyzes the structural composition of the chicana/o novel …y no se lo tragó la tierra, by Tomás Rivera, a book that has become a collective point of reference for chicana/o culture and community. Its structure will be explained, including the importance of personal and collective memory as elements that evolve every chapter as a fragmentary part of a whole. The classical concept of "art of memory" joined to the rhetoric of discourse opens a new perspective to analyze this fragmentation and helps the reader to understand the connection of its elements. Finally, the idea of "theater of memory" may be applied to the novel's chicana/o universe as a dramatic device for structuring the narrator's personal memories, achieving a final literary composition similar to a memorable, collective altarpiece full of impressive images from this community's daily struggle in the 1960s.     

Forest Policy Reform and the Organization of Logging in Peruvian Amazonia

Reform in the forest sector in Peru resulted in a new forestry law, developed with substantial input from international conservation and donor organizations. While it incorporates the principles of sustainable forest management, biodiversity conservation and livelihood improvement, inconsistencies remain between the regulatory mechanisms and actual practices and outcomes in the field, leading some to consider the legal framework a failure. This article suggests that problems in the sector persist because the legal and regulatory frameworks do not incorporate existing local institutions, norms and practices — all of which are rooted in complex historical social, political and economic relationships. Based on information from interviews, data on movement of timber and analysis of secondary information, the authors examine the local structure, actors and dynamics of the concession forestry system in the Peruvian Amazon. The article focuses on how financial, social and political relationships in the network of actors, and particularly the patronage system, have helped actors in the sector adapt to the new policy framework. It is proposed that any further reform in the forest sector must be based on a keen understanding and appreciation of the praxis of timber extraction in the region.     

The thermoluminescence of meteorites: A brief 2010 perspective

Early work on meteorite thermoluminescence, influenced by pottery dating and dosimetry applications, demonstrated a relationship between natural thermoluminescence and (1) the orbital perihelion of a meteorite and (2) the terrestrial age (time since fall) of a meteorite. For 14 years natural TL measurements were routinely made on newly recovered Antarctic meteorites to help identify unusual thermal and radiation histories, and to sort them by terrestrial age and perihelion. Two examples of the value of such data are presented, an Antarctic meteorite that underwent a major orbit change prior to fall and the collection mechanics of meteorites at the Lewis Cliff collection site. A second major area of focus for meteorite TL, that has no non-meteorite heritage, is the use of their induced TL to provide an extraordinarily sensitive and quantitative means of exploring metamorphic intensity and palaeothermometry. While especially valuable for unequilibrated ordinary chondrites, these types of measurement have proved useful with virtually every major class of meteorite, asteroidal and planetary. The challenge now is to extend the technique to small particles, micrometeorites, interplanetary dust particles, and cometary particles.