Multiple Scale Den Site Selection by Swift Foxes, Vulpes velox, in Southeastern Colorado

Predation by Coyotes (Canis latrans) is a major source of mortality in Swift Fox (Vulpes velox) populations. Year-round den use by Swift Foxes is likely to be a predator avoidance strategy. Due to the importance of denning to Swift Fox ecology, we recorded den site selection of Swift Foxes in southeastern Colorado. Den site selection was recorded at two scales: microhabitat characteristics at the den and den placement within the home range. The number of den entrances, height and width of each entrance, aspect, hill position, slope, percent rock in soil, vegetative cover, and horizontal foliar density of 42 Swift Fox dens were examined during December 1999 – April 2000. This was compared to the same microhabitat characteristics at 42 random sites within Swift Fox home ranges to determine if Swift Foxes were using site characteristics according to their availability. Our results indicated that Swift Foxes were not highly selective of den sites based on the microhabitat characteristics evaluated in this study, although Swift Foxes selected areas of intermediate rock percentages. In addition, Swift Foxes were radio-tracked throughout the sample period and the location and frequency of use of known dens were recorded. Within the core area of home ranges, Swift Foxes used more dens (mean = 3.51 ± 1.70 (SD)), and had a higher frequency of use of dens (mean = 8.20 ± 6.01) than in the mid-range area (number of dens, mean = 0.90 ± 0.94; frequency, mean = 1.27 ± 2.12) and the boundary area (number of dens, mean = 0.34 ± 0.53; frequency, mean = 0.45 ± 0.93) of the home range. We discuss our results in terms of the importance of dens in facilitating escape from Coyotes. These results illustrate the need for examining den site selection at multiple scales to determine all selection factors, and to provide information useful for recovery and management efforts for this species

A Tabu-search-based Algorithm for Distribution Network Restoration to Improve Reliability and Resiliency

Fault restoration techniques have always been crucial for distribution system operators (DSOs). In the last decade, it started to gain more and more importance due to the introduction of output-based regulations where DSO performances are evaluated according to frequency and duration of energy supply interruptions. The paper presents a tabu-search-based algorithm able to assist distribution network operational engineers in identifying solutions to restore the energy supply after permanent faults. According to the network property, two objective functions are considered to optimize either reliability or resiliency. The mathematical formulation includes the traditional feeders, number of switching operation limit, and radiality constraints. Thanks to the DSO of Milan, Unareti, the proposed algorithm has been tested on a real distribution network to investigate its effectiveness

Theoretical study of the thermal behavior of free and alumina-supported Fe-C nanoparticles

The thermal behavior of free and alumina-supported iron-carbon nanoparticles is investigated via molecular dynamics simulations, in which the effect of the substrate is treated with a simple Morse potential fitted to ab initio data. We observe that the presence of the substrate raises the melting temperature of medium and large $Fe_{1-x}C_x$ nanoparticles ($x$ = 0-0.16, $N$ = 80-1000, non- magic numbers) by 40-60 K; it also plays an important role in defining the ground state of smaller Fe nanoparticles ($N$ = 50-80). The main focus of our study is the investigation of Fe-C phase diagrams as a function of the nanoparticle size. We find that as the cluster size decreases in the 1.1-1.6-nm-diameter range the eutectic point shifts significantly not only toward lower temperatures, as expected from the Gibbs-Thomson law, but also toward lower concentrations of C. The strong dependence of the maximum C solubility on the Fe-C cluster size may have important implications for the catalytic growth of carbon nanotubes by chemical vapor deposition.Comment: 13 pages, 11 figures, higher quality figures can be seen in article 9 at http://alpha.mems.duke.edu/wahyu

Take Action! The Past, Present, and Future of Sage-Grouse Conservation in Utah

Utah has a 10-year history of local conservation planning for sage-grouse populations. The San Juan County Gunnison Sage-Grouse Local Working Group (SWOG) was formed in 1996 and completed a local conservation plan in 2000; the Parker Mountain Adaptive Resource Management Local Working Group (PARM) was established in 1998 and has been a model for sagegrouse conservation planning throughout the state. In July 2006, most of Utah’s 12 adaptive resource management local working groups completed local conservation plans for sage-grouse that address the unique issues affecting their respective areas. Each local working group is made up of diverse stakeholders including landowners, state and federal agency personnel, and nongovernmental organizations. This effort was achieved through the use of neutral facilitation and coordination provided by Utah State University Extension and The Nature Conservancy’s Conservation Action Planning (CAP) process. We discuss how neutral facilitation and the CAP process contributed to the successes of local working group planning efforts and explore challenges faced along the way. Finally, we discuss the future of community-based conservation and Extension’s role in local conservation planning in the state of Utah

Network automation planning in distribution networks: A feeders coupling method to implement IEC 61850-based smart automation system logic

This paper presents a methodology for distribution networks automation planning. The presented methodology identifies the optimal location of intelligent protection devices for improving network reliability. The approach also analyzed the available back-feeding for implementing an IEC 61850-based smart automation system logic. The back-feeding routes of each feeder are evaluated by comparing suitable performance indexes identifying the more appropriate one able to resupply the considered feeder for most of the potential faults. Of course, topological and electrical constraints have to be fulfilled, and therefore the simulations consider feeder and substation constraints. Thanks to the data given by the local system operator Unareti, the methodology has been tested on a real distribution network located in the South-West area of Milan