Assessing the impacts of mountain biking and hiking on subalpine grassland in Australia using an experimental protocol.

Mountain biking is an increasingly popular, but sometimes controversial, activity in protected areas. Limited research on its impacts, including studies comparing biking with hiking, contributes to the challenges for mangers in assessing its appropriateness. The impacts of mountain bike riding off trail were compared to those of hiking on subalpine grassland in Australia using a modification of a common trampling experimental methodology. Vegetation and soil parameters were measured immediately and two weeks after different intensities of mountain biking (none, 25, 75, 200 and 500 passes across slope, 200 pass up and down slope) and hiking (200 and 500 passes across slope). There were reductions in vegetation height, cover and species richness, as well as changes in species composition and increases in litter and soil compaction with riding. Riding up and down a moderate slope had a greater impact than riding across the slope. Hiking also affected vegetation height, cover and composition. Mountain biking caused more damage than hiking but only at high use (500 passes). Further research including other ecosystems, topography, styles of riding, and weather conditions are required, but under the conditions tested here, hiking and mountain biking appear to be similar in their environmental impacts.

Using social media images to assess ecosystem services in a remote protected area in the Argentinean Andes.

Social media images are a novel source of data to assess how people view and value the environment. Access to these images is often free, the volume and spread of images is expanding rapidly and hence they are an increasingly valuable source of data complementing and expanding on other data. Recently, coding images has been used to assess sociocultural values relating to ecosystem services including those provided by national parks. To further explore the use of social media images, including for remote environments, we analysed the content of images posted to Flickr by people visiting a national park that contains the highest mountain in the southern hemisphere, Mt. Aconcagua, in Argentina, South America. The saliency of aesthetic landscapes, recreation, social relations and fresh-water provisioning was high across the 334 images posted to Flickr by 104 visitors to the Park, but location mattered. Images from visitors in easily accessible day-use areas were significantly more likely to include content that reflects biodiversity-existence, geology, culture and education services, while the content of images from remote areas was more likely to reflect social relations and fresh-water provision services. Comparisons of the content of images from Mt. Aconcagua with other studies in Europe, South America, Asia, Africa and Australia highlight similarities and differences in people's views of the diversity of locations, but also the benefits and limitations of user-generated social media content when assessing environmental and management issues.

A multicopy suppressor screening approach as a means to identify antibiotic resistance determinant candidates in Yersinia pestis.

BACKGROUND: Yersinia pestis is the causative agent of plague and a potential agent of bioterrorism and biowarfare. The plague biothreat and the emergence of multidrug-resistant plague underscore the need to increase our understanding of the intrinsic potential of Y. pestis for developing antimicrobial resistance and to anticipate the mechanisms of resistance that may emerge in Y. pestis. Identification of Y. pestis genes that, when overexpressed, are capable of reducing antibiotic susceptibility is a useful strategy to expose genes that this pathogen may rely upon to evolve antibiotic resistance via a vertical modality. In this study, we explored the use of a multicopy suppressor, Escherichia coli host-based screening approach as a means to expose antibiotic resistance determinant candidates in Y. pestis. RESULTS: We constructed a multicopy plasmid-based, Y. pestis genome-wide expression library of nearly 16,000 clones in E. coli and screened the library for suppressors of the antimicrobial activity of ofloxacin, a fluoroquinolone antibiotic. The screen permitted the identification of a transcriptional regulator-encoding gene (robAYp) that increased the MIC99 of ofloxacin by 23-fold when overexpressed from a multicopy plasmid in Y. pestis. Additionally, we found that robAYp overexpression in Y. pestis conferred low-level resistance to many other antibiotics and increased organic solvent tolerance. Overexpression of robAYp also upregulated the expression of several efflux pumps in Y. pestis. CONCLUSION: Our study provides proof of principle for the use of multicopy suppressor screening based on the tractable and easy-to-manipulate E. coli host as a means to identify antibiotic resistance determinant candidates of Y. pestis.

Using crowd-sourced photos to assess seasonal patterns of visitor use in mountain-protected areas.

Managing protected areas effectively requires information about patterns of visitor use, but these data are often limited. We explore how geotagged photos on Flickr, a popular photo-sharing social-media site, can generate hotspot maps and distribution models of temporal and spatial patterns of use in two mountain-protected areas of high conservation value. In Aconcagua Provincial Park (Argentina), two routes to the summit of Aconcagua were used in summer, but most visitors stayed close to the main road, using formal and informal walking trails and the Visitor Centre, while in winter, there was very limited visitation. In Kosciuszko National Park (Australia), alpine walking trails were popular in summer, but in winter, most visitors stayed in the lower altitude ski resorts and ski trails. Results demonstrate the usefulness of social-media data alone as well as a complement for visitor monitoring, providing spatial and temporal information for site-specific and park-level management of visitors and potential impacts in conservation areas.