The mission of the United States (US) National Park Service (NPS) is to “conserve the scenery and the natural and historic objects and the wild life therein and to provide for the enjoyment of the same in such manner and by such means as will leave them unimpaired for the enjoyment of future generations” (NPS, 1916). NPS currently manages 397 parks covering about 358,200 km2, or approximately 4...

The National Center on Accessibility sponsored this study to identify the perceptions and attitudes of people with physical disabilities toward their experiences related to physical accessibility in the Great Smoky Mountains National Park. A total of 300 questionnaires were distributed to individuals with disabilities onsite. Of these questionnaires, 122 completed and usable questionnaires were...

a Physics Department, Stony Brook University, Stony Brook, NY 11794, United States b Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, United States c Stanford Institute for Materials and Energy Science, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, United States d National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, N...

Water quality and freshwater fish diversity from nine waterfalls at Khao Luang National Park, Thailand was examined. Streams were shallow, fast flowing with clear water and rocky and sandy substrate. The mean water quality of waterfalls at Khao Luang National Park were as following pH 7.50, air temperature 24.27 °C, water temperature 26.37 °C, dissolved oxygen 7.88 mg/l, hardness 4.44-21.33 mg/...

We conduct long-term amphibian monitoring in Yellowstone National Park (YNP) (1) and read McMenamin et al.’s article (2) with interest. This study documents decline in the extent of seasonal wetlands in the Lamar Valley of YNP during extended drought, but the conclusion, widely reported in the media, of ‘‘severe declines in 4 once-common amphibian species,’’ is unsupported. This study wrongly d...

Water-soluble ions such as sulfate may have great impacts on atmospheric pollution. To determine the deposition effect of PM2.5 sulfates, the major PM2.5 constituents, in the forest canopy in Beijing, China, an investigation was carried out in an urban forest, Olympic Forest Park, and a suburban forest, Jiufeng National Forest Park. We measured the vertical distributions of sulfate by using mon...

As software systems grow in size and complexity, so does the di culty of understanding and maintaining them. Research in software understanding attempts to mitigate this problem by making various aspects of software development more visible, accessible, and comprehensible. In this paper we propose a hypertext-based approach to software visualization in which navigation in software-space is mode...