La economía arrocera en la cuenca del Guayas, 1900-1950. Algunas notas al margen (Diálogo Crítico)

Presenta el debate en torno al recientemente publicado estudio, Desmemoria y olvido. La economía arrocera en la cuenca del Guayas, 1920-1950, del historiador ecuatoriano Roque Espinosa.

The Victoria Falls 1900-1940: Landscape, tourism and the geographical imagination

This article is about the politics of landscape ideas, and the relationship between landscape, identity and memory. It explores these themes through the history of the Victoria Falls, and the tourist resort that developed around the waterfall after 1900. Drawing on oral and archival sources, including popular natural history writing and tourist guides, it investigates African and European ideas about the waterfall, and the ways that these interacted and changed in the course of colonial appropriations of the Falls area. The tourist experience of the resort and the landscape ideas promoted through it were linked to Edwardian notions of Britishness and empire, ideas of whiteness and settler identities that transcended new colonial borders, and to the subject identities accommodated or excluded. Cultures of colonial authority did not develop by simply overriding local ideas, they involved fusions, exchanges and selective appropriations of them. The two main African groups I am concerned with here are the Leya, who lived in small groups around the Falls under a number of separate chiefs, and the powerful Lozi rulers, to whom they paid tribute in the nineteenth century. The article highlights colonial authorities' celebration of aspects of the Lozi aristocracy's relationship with the river, and their exclusion of the Leya people who had a longer and closer relationship with the waterfall. It also touches on the politics of recent attempts to reverse this exclusion, and the controversial rewriting of history this has involved.

Argon predissociation spectroscopy of the OH-center dot H2O and Cl-center dot H2O complexes in the 1000-1900 cm(-1) region: Intramolecular bending transitions and the search for the shared-proton fundamental in the hydroxide monohydrate

We present argon predissociation vibrational spectra of the OH-.H2O and Cl-.H2O complexes in the 1000-1900 cm(-1) energy range, far below the OH stretching region reported in previous studies. This extension allows us to explore the fundamental transitions of the intramolecular bending vibrations associated with the water molecule, as well as that of the shared proton inferred from previous assignments of overtones in the higher energy region. Although the water bending fundamental in the Cl-.H2O spectrum is in very good agreement with expectations, the OH-.H2O spectrum is quite different than anticipated, being dominated by a strong feature at 1090 cm(-1). New full-diniensionality calculations of the OH-.H2O vibrational level structure using diffusion Monte Carlo and the VSCF/CI methods indicate this band arises from excitation of the shared proton.

Comparison of results from several AOGCMs for global and regional sea-level change 1900-2100

Sea-level rise is an important aspect of climate change because of its impact on society and ecosystems. Here we present an intercomparison of results from ten coupled atmosphere-ocean general circulation models (AOGCMs) for sea-level changes simulated for the twentieth century and projected to occur during the twenty first century in experiments following scenario IS92a for greenhouse gases and sulphate aerosols. The model results suggest that the rate of sea-level rise due to thermal expansion of sea water has increased during the twentieth century, but the small set of tide gauges with long records might not be adequate to detect this acceleration. The rate of sea-level rise due to thermal expansion continues to increase throughout the twenty first century, and the projected total is consequently larger than in the twentieth century; for 1990-2090 it amounts to 0.20-0.37 in. This wide range results from systematic uncertainty in modelling of climate change and of heat uptake by the ocean. The AOGCMs agree that sea-level rise is expected to be geographically non-uniform, with some regions experiencing as much as twice the global average, and others practically zero, but they do not agree about the geographical pattern. The lack of agreement indicates that we cannot currently have confidence in projections of local sea- level changes, and reveals a need for detailed analysis and intercomparison in order to understand and reduce the disagreements.