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791.
A factor analytic study of attitudinal structure and its impact on rural landowners' access policies
Previous research has shown that rural landowners' hunter access policies are determined in large part by their attitudes
towards hunters, legal liability, conservation, and economic incentives. The results of this study support this research and
indicate that East Texas, USA, landowners' decisions to allow or restrict access are based, in part, on attitudes toward hunter
behavior, hunting as a social activity, leasing as a management practice, and a perceived obligation toward wildlife stewardship.
Attitude-based profiles of landowners who adopted one of four access policies are compared. 相似文献
792.
R. A. Schoney W. J. Brown S. N. Kulshreshtha 《Journal of the American Water Resources Association》1990,26(3):509-517
ABSTRACT: Irrigation development in Saskatchewan was initiated as an instrument to bring forth regional stability through drought proofing and diversification in the agricultural sector. This development has been surrounded by controversies. Particularly, some critics questioning its economic value to the farmer. In this study, irrigation on a farm is compared as a growth alternative to the expansion of dryland farming. Under relatively conservative machine replacement policies, modest family withdrawals, government subsidized irrigation loans, and relatively favorable gross operating margins, irrigation can be a profitable undertaking in the South Saskatchewan River Basin. 相似文献
793.
Bryan BA 《Environmental management》2006,37(1):126-140
The desire to capture natural regions in the landscape has been a goal of geographic and environmental classification and ecological land classification (ELC)
for decades. Since the increased adoption of data-centric, multivariate, computational methods, the search for natural regions
has become the search for the best classification that optimally trades off classification complexity for class homogeneity.
In this study, three techniques are investigated for their ability to find the best classification of the physical environments
of the Mt. Lofty Ranges in South Australia: AutoClass-C (a Bayesian classifier), a Kohonen Self-Organising Map neural network,
and a k-means classifier with homogeneity analysis. AutoClass-C is specifically designed to find the classification that optimally
trades off classification complexity for class homogeneity. However, AutoClass analysis was not found to be assumption-free
because it was very sensitive to the user-specified level of relative error of input data. The AutoClass results suggest that
there may be no way of finding the best classification without making critical assumptions as to the level of class heterogeneity
acceptable in the classification when using continuous environmental data. Therefore, rather than relying on adjusting abstract
parameters to arrive at a classification of suitable complexity, it is better to quantify and visualize the data structure
and the relationship between classification complexity and class homogeneity. Individually and when integrated, the Self-Organizing
Map and k-means classification with homogeneity analysis techniques also used in this study facilitate this and provide information
upon which the decision of the scale of classification can be made. It is argued that instead of searching for the elusive
classification of natural regions in the landscape, it is much better to understand and visualize the environmental structure
of the landscape and to use this knowledge to select the best ELC at the required scale of analysis. 相似文献
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799.
The mental health consequences of exposure to traumatic events and the risk factors for psychological morbidity among expatriate and Kosovar Albanian humanitarian aid workers have not been well studied. In June 2000, we used standardised screening tools to survey 285 (69.5%) of 410 expatriate aid workers and 325 (75.8%) of 429 Kosovar Albanian aid workers from 22 humanitarian organizations that were implementing health programmes in Kosovo. The mean number of trauma events experienced by expatriates was 2.8 (standard deviation: 2.7) and by Kosovar staff 3.2 (standard deviation: 2.8). Although only 1.1% of expatriate and 6.2% of Kosovar aid workers reported symptoms consistent with the diagnosis for post-traumatic stress disorder, 17.2% and 16.9%, respectively, reported symptoms satisfying the definition of depression. Regression analysis demonstrated that the number of trauma events experienced was significantly associated with depression for the two sets of workers. Organisational support services may be an important mediating factor and should be targeted at both groups. 相似文献
800.
P. A. Zadubrovskiy I. V. Zadubrovskaya M. A. Potapov O. F. Potapova V. I. Evsikov 《Russian Journal of Ecology》2016,47(1):82-87
Demographic structure and its seasonal dynamics have been studied in colonies of narrow-skulled voles (Lasiopodomys gregalis Pall.) in Northern Kulunda. Three types of colonies have been distinguished: (I) true colonies (large, complex families), (II) simple families (nuclear or incomplete), and (III) all-male colonies. Changes in their sex, age, and functional composition (based on animal migration activity) during the breeding season have been analyzed. 相似文献