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Tim E. Carpenter Victor L. Coggins Clinton McCarthy Chans S. O’Brien Joshua M. O’Brien Timothy J. Schommer 《Preventive veterinary medicine》2014
Bighorn sheep currently occupy just 30% of their historic distribution, and persist in populations less than 5% as abundant overall as their early 19th century counterparts. Present-day recovery of bighorn sheep populations is in large part limited by periodic outbreaks of respiratory disease, which can be transmitted to bighorn sheep via contact with domestic sheep grazing in their vicinity. In order to assess the viability of bighorn sheep populations on the Payette National Forest (PNF) under several alternative proposals for domestic sheep grazing, we developed a series of interlinked models. Using telemetry and habitat data, we characterized herd home ranges and foray movements of bighorn sheep from their home ranges. Combining foray model movement estimates with known domestic sheep grazing areas (allotments), a Risk of Contact Model estimated bighorn sheep contact rates with domestic sheep allotments. Finally, we used demographic and epidemiologic data to construct population and disease transmission models (Disease Model), which we used to estimate bighorn sheep persistence under each alternative grazing scenario. Depending on the probability of disease transmission following interspecies contact, extirpation probabilities for the seven bighorn sheep herds examined here ranged from 20% to 100%. The Disease Model allowed us to assess the probabilities that varied domestic sheep management scenarios would support persistent populations of free-ranging bighorn sheep. 相似文献
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Muma JB Samui KL Siamudaala VM Oloya J Matop G Omer MK Munyeme M Mubita C Skjerve E 《Tropical animal health and production》2006,38(3):195-206
A cross-sectional study was performed in the livestock–wildlife interface areas of Lochinvar and Blue Lagoon National Parks
and the non-interface area of Kazungula to determine the prevalence of antibodies to Brucella spp. in domestic ruminants and identify individual animal risk factors of infection. A total of 1245 cattle from 124 herds
and 280 goats and sheep from 29 flocks were tested sequentially for Brucella antibodies using the Rose Bengal test (RBT) and competitive ELISA. In cattle, individual seroprevalence ranged from 14.1%
to 28.1%, while herd sero–prevalence ranged from 46.2% to 74.0% in the three study areas. No goat or sheep tested positive
for Brucella antibodies. Three types of cattle grazing strategies were encountered: locally grazed herds (LGH), transhumantly grazed herds
(TGH) and river flood plain grazed herds (FGH). Brucella seroprevalence was seen to vary according to area and grazing strategy: Lochinvar and transhumant grazed herds recorded the
highest figures, respectively. Age, sex and history of abortion were found to have independent effects on individual seroprevalence.
This study establishes that brucellosis is endemic in domestic animals in the livestock–wildlife interface areas of Blue Lagoon
and Lochinvar national parks and the disease is also present in Kazungula. We observed that type of grazing strategy had significant
impact on cattle Brucella seroprevalence and that transhumant herds were at high risk of being infected. 相似文献
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莫莫格湿地干-湿界面优势植物种群动态分析 总被引:1,自引:0,他引:1
莫莫格湿地从高河漫滩底端到顶端选取有代表性的植物群落片断作为固定观测样带,并设置6个观测样方,生长季5月、7月、9月3次观测结果表明,小叶章优势种群5月份密度最高达1154-1594株/平方米,7月种群数量下降,9月有所升高;踏头苔草优势种群5-7月份密度在3 414-7 193株/平方米,9月份种群数量大幅度下降;土壤相对含水量低地段小叶章种群相对优势度大,土壤相对含水量高地段踏头苔草种群相对优势度大,局部地段生长季内有相对优势度相互替代过程,莫莫格湿地干-湿界面上小叶章和踏头苔草两个种群可以共存。 相似文献
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M. Pruvot D. Seidel M.S. Boyce M. Musiani A. Massolo S. Kutz K. Orsel 《Preventive veterinary medicine》2014
In Southwest Alberta, beef cattle and wild elk (Cervus elaphus) have similar habitat preferences. Understanding their inter-species contact structure is important for assessing the risk of pathogen transmission between them. These spatio-temporal patterns of interactions are shaped, in part, by range management and environmental factors affecting elk distribution. In this study, resource selection modeling was used to identify factors influencing elk presence on cattle pasture and elk selection of foraging patches; furthermore, consequences for inter-species disease transmission were discussed. 相似文献
6.
Multi-attribute evaluation of landscape-level fuel management to reduce wildfire risk 总被引:1,自引:0,他引:1
Dan W. Ohlson Trent M. Berry Robert W. Gray Bruce A. Blackwell Brad C. Hawkes 《Forest Policy and Economics》2006,8(8):824-837
This paper provides an example of the practical application of multi-attribute trade-off analysis (MATA) to wildfire management. The MATA approach supports more informed decision-making because it exposes important trade-offs among competing management objectives (requiring value-based choices), helps guide and structure necessary technical judgements, explicitly represents uncertainty (i.e., not just expected outcomes but risk profiles around outcomes) and addresses temporal trade-offs. MATA promotes critical thinking about what analysis is required for decision-making. A MATA approach can be applied for all types of forest and fire management decisions. In this paper, we provide a sample application of MATA to an evaluation of landscape-level fuel treatments for managing wildfire risk. The study area is located in southeastern British Columbia, Canada where historical fire suppression policies and expanding development in wildland urban interface areas have resulted in an increase in both the probability and the consequences of stand replacement fires. We specify management objectives and develop measurable attributes for fire management costs, timber supply, property damage, landscape-level biodiversity, local air quality and climate change. We then simulate the effects on these attributes of four alternative fuel management strategies that include combinations of mechanical treatments and prescribed burning over a 100-year period. The evaluation illustrates the key features of MATA while highlighting the benefits and challenges of implementing the approach. 相似文献
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According to a new trend of telerobot control, some key techniues are researched to solve the Internet telerobotics , such as distributed intelligent computation on the Internet, human-computer interface,and Internet-robot interface etc.The current development status of the Internet telerobotics is reviewed. Based on the new directions of the network software development, the authors discuss that the middleware technique CORBA plays an important role in solving the problems of the Internet telerobotics,and it is an effective way to use Java language to control the telerobot and improve its system performance. The application perspective of the Internet telerobotics is investigated.It is indicated that the development trend of the telerobot control is a human-centred collaboration mechanism of mutual reinforce and coordination in human-machine intelligent. 相似文献
10.
In order to implement the security management of management information system (MIS), a target-based security management architecture is proposed. For MIS users, the user interface (UI) is the only way to interact with the MIS system, so all the objects (targets) which need to be managed on UI is registered first, thus for every target the state such as enabled, not enabled, visible, not visible, readonly etc., is assigned. For some users, a set of targets with some state is assigned so that the management granularity in MIS can reach any degree. This approach provides a very flexible way to the security management in MIS. 相似文献