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This paper examines the demand for hockey game trips among metropolitan and nonmetropolitan residents of Alberta, Canada. Using data on both revealed and stated preference game-trip behavior from a telephone survey conducted throughout Alberta, we estimate the effect of ticket prices, team quality, arena amenities, and capacity on the latent demand for National Hockey League hockey games. We find that lower ticket prices, higher team quality, and additional capacity encourage attendance. In the status quo scenario, consumer surplus per game is $50 for those who had attended hockey games and about 50% less for those who had not attended games. Exploiting the stated preference data, we develop a number of other consumer surplus estimates. We also include travel costs in the estimation of the demand function and estimate the full value of the game trip considering both ticket prices and travel costs. Sold-out arenas in Calgary and Edmonton generate annual consumption benefits of $40 and $35 million when only ticket prices are used to calculate consumer surplus (i.e., excluding travel costs). Considering the full-price consumer surplus for the Calgary Flames of $103 per game trip, the annual consumption benefits may be as high as $82 million. [ABSTRACT FROM AUTHOR]

Please cite this paper as: Krauss et al. (2012) Respiratory tract versus cloacal sampling of migratory ducks for influenza A viruses: are both ends relevant? Influenza and Other Respiratory Viruses DOI: . Background Early studies in dabbling ducks showed that cloacal swabs yielded a larger number of avian influenza virus (AIV) isolates than did respiratory tract swabs. Historically, AIV surveillance has been performed by collecting cloacal or environmental fecal samples only. Highly pathogenic avian influenza H5N1 virus emerged in 1996 and replicated to higher titers in the respiratory rather than the gastrointestinal tract of ducks, prompting the collection of respiratory samples in addition to cloacal swabs from wild birds. Studies confirmed that some virus subtypes, especially H9 and highly pathogenic H5, are shed primarily through the respiratory tract and may not be detected in cloacal swabs. Objectives To examine prevalence and subtype differences for AIV isolates from cloacal or respiratory swabs of wild ducks and to determine whether individual respiratory tract samples should be included in AIV surveillance studies in wild birds. Methods Individual respiratory tract and cloacal swabs were collected from each of 1036 wild ducks in Alberta, Canada, during the month of August from 2007 to 2010 in an ongoing surveillance study. Virus isolation in eggs and subtype identification by antigenic and molecular methods were performed. Results and conclusions Respiratory tract and cloacal swabs yielded ten influenza virus HA subtypes representing 28 HA-NA combinations. Three HA-NA subtype combinations were found exclusively in respiratory tract samples. Only four HA subtypes (H1, H3, H4, and H7) were recovered from respiratory samples, but respiratory shedding was associated with the dominance of 1 year's subtype. Might respiratory shedding provide a risk assessment indicator? [ABSTRACT FROM AUTHOR]

Aim The spatial extent of western Canada’s current epidemic of mountain pine beetle, Dendroctonus ponderosae Hopkins (Coleoptera: Curculionidae, Scolytinae), is increasing. The roles of the various dispersal processes acting as drivers of range expansion are poorly understood for most species. The aim of this paper is to characterize the movement patterns of the mountain pine beetle in areas where range expansion is occurring, in order to describe the fine-scale spatial dynamics of processes associated with mountain pine beetle range expansion. Location Three regions of Canada’s Rocky Mountains: Kicking Horse Pass, Yellowhead Pass and Pine Pass. Methods Data on locations of mountain pine beetle-attacked trees of predominantly lodgepole pine ( Pinus contorta var. latifolia) were obtained from annual fixed-wing aircraft surveys of forest health and helicopter-based GPS surveys of mountain pine beetle-damaged areas in British Columbia and Alberta. The annual (1999–2005) spatial extents of outbreak ranges were delineated from these data. Spatial analysis was conducted using the spatial–temporal analysis of moving polygons (STAMP), a recently developed pattern-based approach. Results We found that distant dispersal patterns (spot infestations) were most often associated with marginal increases in the areal size of mountain pine beetle range polygons. When the mountain pine beetle range size increased rapidly relative to the years examined, local dispersal patterns (adjacent infestation) were more common. In Pine Pass, long-range dispersal (> 2 km) markedly extended the north-east border of the mountain pine beetle range. In Yellowhead Pass and Kicking Horse Pass, the extension of the range occurred incrementally via ground-based spread. Main conclusions Dispersal of mountain pine beetle varies with geography as well as with host and beetle population dynamics. Although colonization is mediated by habitat connectivity, during periods of low overall habitat expansion, dispersal to new distant locations is common, whereas during periods of rapid invasion, locally connected spread is the dominant mode of dispersal. The propensity for long-range transport to establish new beetle populations, and thus to be considered a driver of range expansion, is likely to be determined by regional weather patterns, and influenced by local topography. We conclude that STAMP appears to be a useful approach for examining changes in biogeograpical ranges, with the potential to reveal both fine- and large-scale patterns. [ABSTRACT FROM AUTHOR]

This paper examines patterns of structure in the helminth communities of long-billed curlews collected on their breeding grounds in Alberta, Canada. The communities are neither large nor species rich but they do show evidence of having structure which is mediated by interactive mechanisms between some helminths. In particular, we focus on the role played by congeneric host-specialists in contributing to community patterns and suggest that even in low diversity systems, some species may set the stage around which other species must assort. [ABSTRACT FROM AUTHOR]