Foxes and food subsidies: anthropogenic food use by red and Arctic foxes, and effects on Arctic fox survival, on the Arctic Coastal Plain of Alaska

Thesis (M.S.) University of Alaska Fairbanks, 2013Food subsidies have the potential to impact wildlife on the Arctic Coastal Plain of Alaska. Red foxes (Vulpes vulpes (L., 1758)) expanded their range into Arctic regions during the 20th century, and the availability of anthropogenic foods may have contributed to their success and persistence in the Arctic. Arctic foxes (Vulpes lagopus (L., 1758)) are also known to forage on anthropogenic foods in Prudhoe Bay and to forage on marine mammals on the sea ice, but it is unknown whether these strategies benefit survival of Arctic foxes. This thesis examined: 1) the importance of anthropogenic foods to the diets of red and Arctic foxes in Prudhoe Bay, and 2) the factors with the greatest effect on Arctic fox survival, including access to food subsidies in Prudhoe Bay and on the sea ice. For the first study, stable isotopes of red and Arctic fox tissues were used to infer late summer, late winter, and lifetime (for red fox only) diets. The contribution of anthropogenic foods to the diets of both species was low in late summer (~10%) but high in late winter (49%, 95% credible interval = 38-57%, of red fox diets and 37%, 95% credible interval = 29-44%, of Arctic fox diets). Estimates of lifetime diet in red foxes revealed high levels of anthropogenic food use, similar to the winter diet. To characterize the extent of competition for food resources, dietary niche overlap was examined between both species by comparing isotopic niche space. Both fox species had little isotopic niche overlap but may have greater overlap between their ecological dietary niches. Availability and consumption of anthropogenic foods by red foxes, particularly in winter, may partially explain their year-round presence in Prudhoe Bay. For the second study, nest survival models and satellite collar data were used to evaluate whether multiple factors affected survival of adult and juvenile foxes. Site and sea ice use had two times more support than the other factors. Three groups of foxes were identified based on capture location and sea ice use, which corresponded to different survival rates: Prudhoe Bay foxes, NPR-A foxes that used sea ice during more than eight 2-week periods during the winter (seven 2-week periods for juveniles), and NPR-A foxes that did not use sea ice. Both adult and juvenile foxes at Prudhoe Bay had modestly higher annual survival rates, 0.50 (90% CI 0.31-0.69) and 0.04 (90% CI 0.0-0.08) respectively, than foxes at NPR-A that did not use sea ice, 0.40 (90% CI 0.18-0.62) and 0.01 (90% CI 0.0-0.04) respectively. NPR-A foxes that used sea ice extensively had the highest survival rates. Food subsidies may have far-reaching effects on red and arctic foxes on the Arctic Coastal Plain of Alaska

Building Systemic Practice Into Evaluation Of Knowledge Management Tools

In the absence of any truly systemic approach to IS evaluation, an approach to evaluation of knowledge management tools is described. This uses co-operative inquiry as a participatory action research framework. Evaluation of knowledge management tools is seen as problematic due to the close coupling between the technology and the social system that is attempting to manage its knowledge. The paper first explains the rationale for why co-operative inquiry may be a useful framework for structuring a systemic evaluation. Finally several barriers to implementing the framework at the level of the individual and the group are discussed

Co-Operative Inquiry as a basis for Evaluation of Knowledge Management Tools

This paper highlights the changes needed in the practice of IT evaluation when directed towards IT used to support knowledge management. The paper addresses the need for evaluation to recognise the increased emphasis on IT supporting the work of communities of practice in contrast to simply automating organisational processes. A framework that uses a form of action research (co-operative inquiry) is suggested that attempts to widen participation within the evaluation process and to enrich the purpose to which evaluation is put, especially in regard to the IS practitioner and IS users

Spatial Electron-hole Separation in a One Dimensional Hybrid Organic-Inorganic Lead Iodide.

The increasing efficiency of the inorganic-organic hybrid halides has revolutionised photovoltaic research. Despite this rapid progress, the significant issues of poor stability and toxicity have yet to be suitably overcome. In this article, we use Density Functional Theory to examine (Pb2I6) · (H2DPNDI) · (H2O) · (NMP), an alternative lead-based hybrid inorganic-organic solar absorber based on a photoactive organic cation. Our results demonstrate that optical properties suitable for photovoltaic applications, in addition to spatial electron-hole separation, are possible but efficient charge transport may be a limiting factor

Blind adaptive equalization of polarization-switched QPSK modulation

Coherent detection in combination with digital signal processing has recently enabled significant progress in the capacity of optical communications systems. This improvement has enabled detection of optimum constellations for optical signals in four dimensions. In this paper, we propose and investigate an algorithm for the blind adaptive equalization of one such modulation format: polarization-switched quaternary phase shift keying (PS-QPSK). The proposed algorithm, which includes both blind initialization and adaptation of the equalizer, is found to be insensitive to the input polarization state and demonstrates highly robust convergence in the presence of PDL, DGD and polarization rotation. (C)2011 Optical Society of Americ