Traffic volume and highway permeability for a mammalian community in the Canadian Rocky Mountains

We examined whether highway traffic volume changed the rates of movement (habitat permeability) for ten mammalian species in the central Canadian Rocky Mountains. Winter track count data were collected on four highways of varying traffic volume: the Trans-Canada Highway (TCH) (14,000 annual average daily traffic [AADT]) and 1A Highway (3,000 AADT) in Banff National Park and the Highway 40 (5,000 AADT) and Smith Dorrien Trail in Kananaskis Country (2,000 AADT). Permeability represented the ratio of road crossing tracks/km to tracks/km on transects adjacent to roads. We compared permeability at the community level and for carnivore and ungulate guilds, using a Kruskal–Wallis H -test. Traffic volume significantly reduced habitat permeability for the community ( P  < 0.05). Pair-wise Kruskal–Wallis tests showed that habitat permeability was significantly reduced for carnivores at high traffic volume ( P  = 0.008) and for ungulates at very high traffic volume ( P  < 0.043). Cross-referencing with winter traffic counts, we found movement was impaired for carnivores when traffic ranged from 300 to 500 vehicles per day (VPD) and for ungulates between 500 and 5,000 VPD. Our results indicated that the TCH requires mitigation to restore habitat permeability for all species and yielded strong evidence that the Highway 40 is a priority for mitigation.     

Intensities of Feeling: Towards a Spatial Politics of Affect

Abstract This paper attempts to take the politics of affect as not just incidental but central to the life of cities, given that cities are thought of as inhuman or transhuman entities and that politics is understood as a process of community without unity. It is in three main parts. The first part sets out the main approaches to affect that conform with this approach. The second part considers the ways in which the systematic engineering of affect has become central to the political life of Euro‐American cities, and why. The third part then sets out the different kinds of progressive politics that might become possible once affect is taken into account. There are some brief conclusions.     

The origins of two purportedly pre-Columbian Mexican crystal skulls

The well-known life-size rock crystal skull in the British Museum was purchased in 1897 as an example of genuine pre-Columbian workmanship, but its authenticity has been the subject of increasing speculation since the 1930s. This paper is concerned with the history, technology and material of the skull and another larger white quartz skull, donated recently to the Smithsonian Institution. Manufacturing techniques were investigated, using scanning electron microscopy to examine tool marks on the artefacts, and compared with Mesoamerican material from secure contexts. A Mixtec rock crystal goblet and a group of Aztec/Mixtec rock crystal beads show no evidence of lapidary wheels. They were probably worked with stone and wood tools charged with abrasives, some of which may have been as hard as corundum. Textual evidence for Mexican lapidary techniques during the early colonial period, supported by limited archaeological evidence, also indicates a technology without the wheel, probably based on natural tool materials. In contrast, the two skulls under consideration were carved with rotary wheels. The British Museum skull was worked with hard abrasives such as corundum or diamond, whereas X-ray diffraction revealed traces of carborundum (SiC), a hard modern synthetic abrasive, on the Smithsonian skull. Investigation of fluid and solid inclusions in the quartz of the British Museum skull, using microscopy and Raman spectroscopy, shows that the material formed in a mesothermal metamorphic environment equivalent to greenschist facies. This suggests that the quartz was obtained from Brazil or Madagascar, areas far outside pre-Columbian trade networks. Recent archival research revealed that the British Museum skull was rejected as a modern artefact by the Museo Nacional de Mexico in 1885, when offered for sale by the collector and dealer, Eugène Boban. These findings led to the conclusion that the British Museum skull was worked in Europe during the nineteenth century. The Smithsonian Institution skull was probably manufactured shortly before it was bought in Mexico City in 1960; large blocks of white quartz would have been available from deposits in Mexico and the USA.     

Provenance of Coals Recovered from the Wreck of HMAV Bounty

Coal samples from HMAV Bounty were analysed using standard techniques to shed light on their provenance. Petrographic analysis indicated they were Carboniferous, with high vitrinite and liptinite content and a mean random reflectance of vitrinite of 0.99%. Palynological analysis indicated the samples were derived from the Middle Coal Measures, Westphalian B. Combining coal rank (vitrinite reflectance), age, knowledge of seam distributions and coalfield history indicates the most like source to be the Durham Coalfield, possibly the Hutton or Low Main Seams. These coals were mined along the valley of the Weir in the latter part of the 18th century.
© 2007 The Authors