Western Canada is experiencing an unprecedented outbreak of the mountain pine beetle (MPB). The MPB has the potential to impact some of Canada's national parks by affecting park ecosystems and the visitor experience. Controls have been initiated in some parks to lessen the impacts and to prevent the beetle from spreading beyond park boundaries. We examine the perception of ecological risk associated with MPB in two of Canada's national parks, the factors affecting perceptions of risk, and the influence of risk judgments on support for controlling MPB outbreaks in national parks. Data were collected using two studies of park visitors: a mail survey in 2003 and an onsite survey in 2005. The MPB was rated as posing a greater risk to the health and productivity of park ecosystems than anthropogenic hazards and other natural disturbance agents. Visitors who were familiar with MPB rated the ecological and visitor experience impacts as negative, unacceptable, and eliciting negative emotion. Knowledge and residency were the most consistent predictors of risk judgments. Of knowledge, risk, and demographic variables, only sex and risk to ecosystem domains influenced support for controlling the MPB in national parks. Implications for managing MPB in national parks, visitor education, and ecological integrity are discussed. 相似文献
In the paper we present a new method of calculating sampling intervals, so-called windows, allowing an experimenter some flexibility in timing the sample collection, while a minimum required design efficiency for parameter estimation is assured. The method is based on the Equivalence Theorem for D-optimality what makes the length of each window related to the parameter sensitivities. An example of calculating the windows in a pharmacokinetic study is presented. Some other methods of calculating efficient sampling windows are briefly discussed. 相似文献
The Emerson (1968, Biometrics 24 , 695–701) recurrence relation has many important applications in statistics. However, the original derivation applied only to discrete distributions. In the following, a simple derivation is given that generalizes the Emerson recurrence relation to any distribution for which the necessary expectations exist. A modern application is outlined. 相似文献
The study investigated the relationship between objective and subjective indicators of economic well-being within different age, race, and sex groups over time. Stratification theory and an accommodation hypothesis were used to predict differential subjective responses to objective conditions within subgroups. Findings supported the hypothesis that the relationship would be weakest among the oldest age group compared to other age groups. Support was found for the hypothesis that predicted smaller coefficients among subgroups characterized as older, female, and nonwhite. Relationships were found to remain stable within all subgroups over time. 相似文献
The lack of attention in academic discourse to representations of disability in films from the Middle East has led to an incomplete picture of representations of disability in global cinema. For instance, the diverse meanings of disability in Iranian cinema and the influence of disability on the emergence of Iranian New Wave cinema have been almost completely ignored by scholars. A number of award-winning films from Iran have featured disability as central to their narratives – such as The House is Black (1963), Taste of Cherry (1997), The Color of Paradise (1999), The Willow Tree (2005), and The Painting Pool (2013). Disability in these films serves alternatively as a symbol of spiritual possibility, a mark of marginalization, and a covert social critique. These films examine the emotional, physical, and social implications of disability, while celebrating the cultural power of film to challenge social, religious, and artistic barriers. 相似文献
This paper explores how second-generation Tamil-Canadian university students have modified their ‘cultural heritage’ in the period after the defeat of the Liberation Tigers of Tamil Eelam (LTTE) in May 2009. Using a generational framework suggested by the work of Karl Mannheim, I show that the events of May 2009 situated second-generation Tamil-Canadian political activism as a response to the ambivalence of their parents to the conflict in Sri Lanka. Second-generation Tamil-Canadians are also shown to have altered the key LTTE symbol of the Maaveerar (great hero) to better fit a transnational social field that is framed by the new realities of post-LTTE Sri Lanka and by intolerance to imported conflict in Canada. I argue that the Tamil second generation is highly engaged with the politics of their cultural identity, and that this engagement may have a lasting influence on transnational Tamil identity and on the political status of the Tamil community within Canada. 相似文献
In this paper we introduce a new three-parameter exponential-type distribution. The new distribution is quite flexible and can be used effectively in modeling survival data and reliability problems. It can have constant, decreasing, increasing, upside-down bathtub and bathtub-shaped hazard rate functions. It also generalizes some well-known distributions. We discuss maximum likelihood estimation of the model parameters for complete sample and for censored sample. Additionally, we formulate a new cure rate survival model by assuming that the number of competing causes of the event of interest has the Poisson distribution and the time to this event follows the proposed distribution. Maximum likelihood estimation of the model parameters of the new cure rate survival model is discussed for complete sample and censored sample. Two applications to real data are provided to illustrate the flexibility of the new model in practice. 相似文献
This paper compares the monetary and living standards approaches to poverty using Australian data for the period 2006–2017. The aim is to highlight the conceptual and empirical strengths and weaknesses of the two approaches and identify the similarities and differences that emerge when both are applied to examine what happened over the period and to a limited degree, why. The acknowledged limitations of estimating poverty rates by comparing household income with a poverty line have to a degree been addressed by developments in deprivation research that have generated estimates that are more directly related to living standards, more democratic and more credible. But this approach also has limitations, so its growing popularity need not signify the end of poverty line studies. This paper compares the two approaches, with specific attention paid to ensuring that the estimates are internally consistent over time and comparable at a point in time. Both show a consistent pattern of modest improvement in social disadvantage over the period examined, but they reveal different aspects of change. The monetary approach highlights the role of housing costs in driving changes in poverty, while the more nuanced explanation generated by estimates of deprivation provides detailed insights. The results suggest that each has a positive role to play in better understanding the nature of poverty and identifying the factors driving change over time.