176,653 research outputs found
Unoriented geometric functors
Farrell and Hsiang noticed that the geometric surgery groups defined By Wall,
Chapter 9, do not have the naturality Wall claims for them. They were able to
fix the problem by augmenting Wall's definitions to keep track of a line
bundle.
The definition of geometric Wall groups involves homology with local
coefficients and these also lack Wall's claimed naturality.
One would hope that a geometric bordism theory involving non-orientable
manifolds would enjoy the same naturality as that enjoyed by homology with
local coefficients. A setting for this naturality entirely in terms of local
coefficients is presented in this paper.
Applying this theory to the example of non-orientable Wall groups restores
much of the elegance of Wall's original approach. Furthermore, a geometric
determination of the map induced by conjugation by a group element is given.Comment: 12 pages, LaTe
Social-ecological soundscapes: examining aircraft-harvester-caribou conflict in Arctic Alaska
Thesis (M.S.) University of Alaska Fairbanks, 2017As human development expands across the Arctic, it is crucial to carefully assess the impacts to remote natural ecosystems and to indigenous communities that rely on wild resources for nutritional and cultural wellbeing. Because indigenous communities and wildlife populations are interdependent, assessing how human activities impact traditional harvest practices can advance our understanding of the human dimensions of wildlife management. Indigenous communities across Arctic Alaska have expressed concern over the last four decades that low-flying aircraft interfere with their traditional harvest practices. For example, communities often have testified that aircraft disturb caribou (Rangifer tarandus) and thereby reduce harvest opportunities. Despite this longstanding concern, little research exists on the extent of aircraft activity in Arctic Alaska and on how aircraft affect the behavior and perceptions of harvesters. Therefore, the overarching goal of my research was to highlight the importance of aircraft-harvester conflict in Arctic Alaska and begin to address the issue using a scientific and community-driven approach. In Chapter 1, I demonstrated that conflict between aircraft and indigenous harvesters in Arctic Alaska is a widespread, understudied, and complex issue. By conducting a meta-analysis of the available literature, I quantified the deficiency of scientific knowledge about the impacts of aircraft on rural communities and traditional harvest practices in the Arctic. My results indicated that no peer-reviewed literature has addressed the conflict between low-flying aircraft and traditional harvesters in Arctic Alaska. I speculated that the scale over which aircraft, rural communities, and wildlife interact limits scientists' ability to determine causal relationships and therefore detracts from their interest in researching the human dimension of this social-ecological system. Innovative research approaches like soundscape ecology could begin to quantify interactions and provide baseline data that may foster mitigation discourses among stakeholders. In Chapter 2, I employed a soundscape-ecology approach to address concerns about aircraft activity expressed by the Alaska Native community of Nuiqsut. Nuiqsut faces the greatest volume of aircraft activity of any community in Arctic Alaska because of its proximity to intensive oil and gas activity. However, information on when and where these aircraft are flying is unavailable to residents, managers, and researchers. I worked closely with Nuiqsut residents to deploy acoustic monitoring systems along important caribou harvest corridors during the peak of caribou harvest, from early June through late August 2016. This method successfully captured aircraft sound and the community embraced my science for addressing local priorities. I found aircraft activity levels near Nuiqsut and surrounding oil developments (12 daily events) to be approximately six times greater than in areas over 30 km from the village (two daily events). Aircraft sound disturbance was 26 times lower in undeveloped areas (Noise Free Interval =13 hrs) than near human development (NFI = 0.5 hrs). My study provided baseline data on aircraft activity and noise levels. My research could be used by stakeholders and managers to develop conflict avoidance agreements and minimize interference with traditional harvest practices. Soundscape methods could be adapted to rural regions across Alaska that may be experiencing conflict with aircraft or other sources of noise that disrupt human-wildlife interactions. By quantifying aircraft activity using a soundscape approach, I demonstrated a novel application of an emerging field in ecology and provided the first scientific data on one dimension of a larger social-ecological system. Future soundscape studies should be integrated with research on both harvester and caribou behaviors to understand how the components within this system are interacting over space and time. Understanding the long-term impacts to traditional harvest practices will require integrated, cross-disciplinary efforts that collaborate with communities and other relevant stakeholders. Finally, my research will likely spark efforts to monitor and mitigate aircraft impacts to wildlife populations and traditional harvest practices across Alaska, helping to inform a decision-making process currently hindered by an absence of objective data
Polarization diversity monopulse tracking receiver Patent
Polarization diversity monopulse tracking receiver design without radio frequency switche
Gravitational Mediation of Supersymmetry Breaking in Superstring Theory
SUSY breaking and its mediation are among the most important problems of
supersymmetric generalizations of the standard model. The idea of
gravity-mediated SUSY breaking, proposed in 1982 by Arnowitt, Chamseddine and
Nath, and independently by Barbieri, Ferrara and Savoy, fits naturally into
superstring theory, where it can be realized at both classical as well as
quantum levels. This talk is dedicated to Pran Nath on his 65th birthday.Comment: 8 pages. Dedicated to Pran Nath on his 65th birthda
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