Visual preferences of a forest trail environment

Recreation resource managers are becoming increasingly aware of the importance of the visual resource to recreationists. Hiking forest trails is an extremely popular recreational activity; however, little information exists concerning how visitors visually perceive forest trails and how resource managers might manage these environments to enhance the benefits derived from a hiking experience. The major objective of the study was to determine the visual preferences of visitors to a forest trail in Great Smoky Mountains National Park in Tennessee. Of particular interest was the relationship of preference and familiarity for various scenes along the trail. An environmental preference and visual information processing approach underlie the study. A total of 750 visitors were interviewed on-site during the summer of 1982. Although some of the visitors were asked to view photographs of the forest trail environment just prior to their hike, most were shown the photos only upon completing their hike. Visitors were asked to indicate their preference (depending on the treatment) or familiarity (on a 5-point Likert scale) for each photographed scene. Information was also obtained about visitors\u27 past and present hiking experience in addition to other background variables. Photographs for the study questionnaire included some taken by the researcher and some taken by visitors. Results indicate that although visitors rate most of the forest trail scenes fairly high, they do prefer certain scenes over others. Highly preferred are scenes containing water, the trail or ravines. In addition, scenes are preferred that contain an element of hidden, but promised information which entices one to enter the scene deeper and to explore it more fully. When the photos were grouped according to patterns of commonalities through factor analytic procedures, the factor that contained scenes of water was the most preferred, while the factor dominated by felled trees, tangled underbrush, or exposed roots in the foreground was least preferred. Four factors or forest trail scene dimensions, in total, were identified by the factor analysis. The information processing model used, in addition to the physical descriptions for interpreting the forest trail scene dimensions, showed complexity and mystery (the promise of more information) to be very important predictors of preference. Familiarity was shown to be an important component of preference. Scenes visitors rated most familiar were likely to be scenes that rated high on preference. Considerable visual information appears to enter memory as a result of on-site experiences. In addition, interpretive signs, located at certain scenes along the trail, significantly increased preference and familiarity ratings. Application of the research is directed toward trail planners and interpreters of the forest. Knowledge of which forest scenes and features visitors prefer permits the resource manager to locate trails on a basis other than intuition and geological site characteristics to better meet the needs of recreationists. It also provides a basis for managing the visual resources of forest environments

Do Antibiotic Intramedullary Dowels Assist in Eradicating Infection in Two-Stage Resection for Septic Total Knee Arthroplasty?

Background Evidence suggests approximately 40% of intramedullary (IM) canals are culture positive at resection for infected knee arthroplasty. While commonly utilized, no clinical data on the efficacy of antibiotic-eluding IM dowels exist. We quantified treatment success with and without the use of antibiotic-eluding IM dowels in two-stage treatment of periprosthetic knee infection using static and articulating antibiotic cement spacers. Methods 109 consecutive patients who underwent two-stage treatment for periprosthetic knee infection were reviewed. Treatment failure, defined as repeat resection before reimplantation or recurrent infection within 6 months of reimplantation, was evaluated based on spacer type and use of IM dowels, accounting for infection type and systemic host and local extremity grade. Results After exclusions for confounds, articulating spacers without IM dowels were used in 49 (57.7%) cases, articulating spacers with IM dowels in 14 cases (16.5%), and static spacers with IM dowels in 22 (25.9%) cases. Treatment success regardless of infection classification was 85.7% for articulating spacers with IM dowels, 89.8% for articulating spacers without IM dowels, and 68.2% for static spacers with IM dowels (P = .074). In chronically infected poor hosts with compromised extremities, treatment success remained highest in patients with articulating spacers with (90.9%) or without (92.9%) IM dowels compared with static spacers with IM dowels (68.4%) (P = .061). Conclusion Findings suggest that the use of IM dowels did not enhance infection eradication above and beyond that observed for articulating spacers alone, including in the worst cases involving chronically infected poor hosts with compromised extremities

Time correlation function and finite field approaches to the calculation of the fifth order Raman response in liquid xenon

The fifth order, two-dimensional Raman response in liquid xenon is calculated via a time correlation function (TCF) theory and the numerically exact finite field method. Both employ classical molecular dynamics simulations. The results are shown to be in excellent agreement, suggesting the efficacy of the TCF approach, in which the response function is written approximately in terms of a single classical multitime TCF. (c) 2006 American Institute of Physics

Formation of Ferroelectrically Defined Ag Nanoarray Patterns

In order to produce the most effective Ag nanoarrays for plasmon enhanced fluorescence and Raman scattering made using ferroelectric substrates, the optimum conditions for the creation of arrays must be identified. We study here Ag nanopattern arrays formed using ferroelectric lithography based on periodically proton exchanged (PPE) template methods. We examine different conditions in regard to deposition of Ag nanoparticles and analyze the plasmon enhanced signal from the resulting nanoarray. We apply FLIM (fluorescence lifetime imaging) to assess different Ag nanoarray preparation conditions on fluorescence emission from selected fluorphores. In addition, we apply Raman and luminescence spectroscopy with AFM (atomic force microscopy) to study the plasmon enhancement of luminescence and Raman from the Ag nanoarrays

The Science Performance of JWST as Characterized in Commissioning

This paper characterizes the actual science performance of the James Webb Space Telescope (JWST), as determined from the six month commissioning period. We summarize the performance of the spacecraft, telescope, science instruments, and ground system, with an emphasis on differences from pre-launch expectations. Commissioning has made clear that JWST is fully capable of achieving the discoveries for which it was built. Moreover, almost across the board, the science performance of JWST is better than expected; in most cases, JWST will go deeper faster than expected. The telescope and instrument suite have demonstrated the sensitivity, stability, image quality, and spectral range that are necessary to transform our understanding of the cosmos through observations spanning from near-earth asteroids to the most distant galaxies.Comment: 5th version as accepted to PASP; 31 pages, 18 figures; https://iopscience.iop.org/article/10.1088/1538-3873/acb29

The James Webb Space Telescope Mission

Twenty-six years ago a small committee report, building on earlier studies, expounded a compelling and poetic vision for the future of astronomy, calling for an infrared-optimized space telescope with an aperture of at least $4m$. With the support of their governments in the US, Europe, and Canada, 20,000 people realized that vision as the $6.5m$ James Webb Space Telescope. A generation of astronomers will celebrate their accomplishments for the life of the mission, potentially as long as 20 years, and beyond. This report and the scientific discoveries that follow are extended thank-you notes to the 20,000 team members. The telescope is working perfectly, with much better image quality than expected. In this and accompanying papers, we give a brief history, describe the observatory, outline its objectives and current observing program, and discuss the inventions and people who made it possible. We cite detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space Telescope Overview, 29 pages, 4 figure

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements