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981.
《Ostrich》2013,84(1):75-76
Recent largely unexplained deaths in African flamingos have prompted the need for standard, reproducible methods for the post-mortem examination of these birds, for the taking of samples and for the recording of findings. Here we describe suitable techniques and present three distinct protocols for field-based post-mortem examination of flamingos that can be employed flexibly, depending on the circumstances, by veterinarians and non-professionals alike. The adoption of these protocols is strongly recommended to improve standardisation of data and sample collection, which will ultimately enhance our understanding of the causes of mortality in African flamingos. 相似文献
982.
ZHI-GAO ZENG ANDREW K. SKIDMORE YAN-LING SONG TIE-JUN WANG HUI-SHENG GONG 《The Journal of wildlife management》2008,72(3):611-617
Abstract: We studied seasonal movements of golden takin (Budorcas taxicolor bedfordi), a large, social, forest-dwelling ungulate, by radiotracking and field surveys during 1995–1996 and 2002–2005 at Foping National Nature Reserve on the southern slope of the Qinling Mountains, China. Takins inhabited forests and subalpine meadows at an altitudinal range from 1,360 m to 2,890 m. Our results showed that golden takins had a complicated seasonal movement pattern and underwent altitudinal migration 4 times each year. Takins occupied a high-altitude range during summer, stayed at low-altitude ranges for short periods during spring and autumn, and resided at an intermediate-altitude range during winter. Changes in plant phenology may have caused seasonal movements. Reserves for takin conservation should incorporate lower altitude habitats than those takins use in spring and autumn, and seasonal movements by takins should be protected from disturbance by human activities. (JOURNAL OF WILDLIFE MANAGEMENT 72(3):611–617; 2008) 相似文献
983.
Dendrogeomorphology has been recognized as a useful tool to reconstruct past snow avalanche chronologies, especially in remote areas where archives are non-existent. In recent years, there have been a multiplicity of snow avalanche studies based on tree-ring analysis. Yet, the dendrogeomorphic procedure applied to snow avalanches still lacks consensus within the scientific community. This paper illustrates four issues regarding this method encountered on a dataset encompassing 293 trees sampled from 4 sites in the White Mountains (New Hampshire, United States). (1) Separating a sample in an upslope and downslope subgroup allowed to reconstruct a more thorough avalanche chronology. (2) On the other hand, a strong response at a site sheltered from any avalanche track was attributed to extreme snow loadings with a return period well above 100 years. (3) In addition to climatic disturbances, ecological disturbances such as windthrows can cause an anatomical response in the trees similar to snow avalanches. An avalanche track might act as a wind tunnel, making the underlying runout zone a suitable site to windfalls. Sampling in transects can assist in determining the limit between avalanche-related and wind-related disturbances. (4) Early-spring torrential floods and avalanche activities at a multi-process site exhibit distinct spatial patterns in the dendrogeomorphological response that allow discrimination between the two processes in the reconstruction of past chronologies. While the dendrogeomorphologist should be cautious of these issues, their acknowledgement is an opportunity to understand the interactions between the different ecological, climatic and geomorphological processes operating on the forested slopes in the alpine–subalpine environment. 相似文献
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Rainstorm hazards seriously affect the lives of residents and activities of tourists in rainstorm harder-hit scenic areas. The assessment of rainstorm hazard risk has a great significance in the area. Based on the disciplines of geography and tourism, an assessment system has been constructed by using the Entropy Weight-Analytic Hierarchy Process and exponential model. Finally, the Huayang Ancient Town Scenic Area in China has been taken as study area, and its rainstorm hazard risk and spatial distribution have been evaluated. The results indicate the following: The rainstorm hazard risk areas are mainly concentrated along rivers, valleys, or roads; The specific spatial distributions are: rainstorm hazard risk of the Huayang Old Streets is high, that of the Red Cliff Valley and both sides of the Mandarin Duck River are higher, that of the Golden Monkey Valley and the Macaque Park are lower, that of the Tangluo Ancient Road is low, and the risks of other areas are medium; The main influencing factors of rainstorm hazard risk are elevation, terrain, gap and width of river, distance to river, building density, tourist flow and tourism activity; People's awareness, system of monitoring and early warning, emergency plan, facilities and equipment for rainstorm hazard prevention and mitigation need to be continuously improved. 相似文献
987.
《Cell calcium》2018
In mammals, the sense of hearing arises through a complex sequence of morphogenetic events that drive the sculpting of the auditory sensory epithelium into its terminally functional three-dimensional shape. While the majority of the underlying mechanisms remain unknown, it has become increasingly clear that Ca2+ signaling is at center stage and plays numerous fundamental roles both in the sensory hair cells and in the matrix of non-sensory, epithelial and supporting cells, which embed them and are tightly interconnected by a dense network of gap junctions formed by connexin 26 (Cx26) and connexin 30 (Cx30) protein subunits. In this review, we discuss the intricate interplay between Ca2+ signaling, connexin expression and function, apoptosis and autophagy in the crucial steps that lead to hearing acquisition. 相似文献
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Elevational patterns of non‐volant small mammal species richness in Gyirong Valley,Central Himalaya: Evaluating multiple spatial and environmental drivers 下载免费PDF全文
Yiming Hu Kun Jin Zhiwen Huang Zhifeng Ding Jianchao Liang Xinyuan Pan Huijian Hu Zhigang Jiang 《Journal of Biogeography》2017,44(12):2764-2777