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Evaluation of wildlife‐habitat relationships at the landscape level provides insight into how habitat connectivity, fragmentation and land‐use changes may affect wildlife populations. Although previous studies have demonstrated that habitat composition and configuration at large scales may affect the presence, survival and movement of carnivore species, no such analyses have been conducted for the gray fox Urocyon cinereoargenteus. We used a generalized correlative mapping approach to investigate the relationship of gray fox relative abundance to landscape variables at the county scale in Illinois, USA. Relative abundance of gray foxes was high in 37 of 102 (36%) counties. Four models were competitive based on ΔAICc scores, and these models indicated that standard deviation of the perimeter‐area ratio of agricultural patches, interspersion and juxtaposition index of grassland patches, coefficent of variation of the proximity index of forest patches and relative patch richness of the landscape affected gray fox relative abundance. The variables occurring in our competing models indicate that the relative abundance of the gray fox is higher in counties containing a high level of fragmentation of preferred habitat types (i.e. forests and grasslands) and lower dispersion of less preferred habitat types (i.e. agriculture). Our results reflect gray fox habitat use at smaller scales, and at the landscape scale, gray fox abundance is influenced by how cover‐type patches are configured.

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A practical approach to the problem of ion track radial energy distribution has been developed in a computer calculation. This approach uses an existing theory that analytically describes the spatial energy deposition by delta rays. The results agree favorably with a Monte Carlo calculation that is more realistic but much less practical. Several cases of incident ions in silicon have been calculated and results presented. The information is useful as input to problems requiring initial track structure for charge transport in semiconductor applications.

SEUs in the CRRES MEP showed a dramatic increase during a solar flare, the influence of the flare varied widely among device types, and a GaAs RAM showed a different response to the proton belts than some Si RAMS. Corrections to the SEU rate to account for orbital dwell time emphasize the dramatic difference between the rate in the proton belts and the rate due to cosmic ray ions above the belts. In the case of one device, apparent total dose damage resulted in a large increase in upsets due to unreliable device operation.

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