The Alaska Arctic Vegetation Archive (AVA-AK)

The Alaska Arctic Vegetation Archive (AVA-AK, GIVD-ID: NA-US-014) is a free, publically available database archive of vegetation-plot data from the Arctic tundra region of northern Alaska. The archive currently contains 24 datasets with 3,026 non-overlapping plots. Of these, 74% have geolocation data with 25-m or better precision. Species cover data and header data are stored in a Turboveg database. A standardized Pan Arctic Species List provides a consistent nomenclature for vascular plants, bryophytes, and lichens in the archive. A web-based online Alaska Arctic Geoecological Atlas (AGA-AK) allows viewing and downloading the species data in a variety of formats, and provides access to a wide variety of ancillary data. We conducted a preliminary cluster analysis of the first 16 datasets (1,613 plots) to examine how the spectrum of derived clusters is related to the suite of datasets, habitat types, and environmental gradients. We present the contents of the archive, assess its strengths and weaknesses, and provide three supplementary files that include the data dictionary, a list of habitat types, an overview of the datasets, and details of the cluster analysis

The Relationship between Working Conditions and Commercial Pilot Fatigue Development

Fatigue is an important factor in aviation accidents, and effective fatigue management requires understanding the relationship between working conditions and fatigue. Two studies were conducted to clarify the relationship between working conditions and fatigue. In the first study, 59 airline pilots completed a workload questionnaire and the Profile of Mood States (POMS) in the morning and at the completion of their final flight of the day. In the second study, 133 pilots completed a revised questionnaire and the POMS. In both samples, fatigue increased and vigor levels decreased. Regression of fatigue increase upon working conditions indicated that the number of takeoffs and landings during the day were related to fatigue development. Correlation of incident level with both weather and airport difficulty suggest that incident level is a function of weather conditions and airport difficulty. These results argue that fatigue management should be founded upon the demands of working conditions, not merely the simplistic assessment of hours of work

An investigation of the spin structure of the proton in deep inelastic scattering of polarised muons on polarised protons

Ashman J, Badelek B, Baum G, et al. An investigation of the spin structure of the proton in deep inelastic scattering of polarised muons on polarised protons. Nucl.Phys. B. 1989;328(1):1-35