Mark McCann

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OpenGeoDa is the open source successor to GeoDa, a software package designed to introduce non-experts to spatial data analysis. GeoDa was developed under the auspices of the NSF funded Center for Spatially Integrated Social Science (CSISS) [4]. Since its release in 2003, "Legacy GeoDa" has gained over 40,000 individual users and has become a standard to(More)
As computational systems scale to arbitrarily large sizes, and as they are expected to function reliably for arbitrary lengths of time, there are certain realities of the physical world that can not be ignored in the design and modeling of computational systems. For example, considerations for the delivery of power and removal of heat seem to limit the(More)
A commonly used model for fault-tolerant computation is that of cellular automata. The essential difficulty of fault-tolerant computation is present in the special case of simply remembering a bit in the presence of faults, and that is the case we treat in this paper. We are concerned with the degree (the number of neighboring cells on which the state(More)
A high incidence of Tomato spotted wilt virus (TSWV) has occurred in crops in Virginia and other Mid-Atlantic states this season. Be on the lookout for this plant virus in tomatoes, peppers, peanuts, potatoes, and tobacco. The disease also affects numerous weed and ornamental plant species. The virus is vectored by at least 7 different species of thrips. In(More)
When growing vegetables and specialty crops, a soil high in organic matter is very desirable. When examining soils in Virginia, we struggle to find soils that are naturally high in organic matter. Soils with 3 to 5 % soil organic matter would need little additional fertilizer, if any, for producing some crops. Since our native soils don't come any where(More)
Editor's note: the following article was written as a class assignment for Dr. Greg Welbaum's Vegetable Production course at Virginia Tech. Emily provides some good history and information on the CSA marketing option for specialty crop growers. Community Supported Agriculture is a relatively new trend in agricultural production. As mid-sized farms are(More)
The European corn borer, Ostrinia nubilalis Hubner (Lepidoptera: Crambidae), is one of the most economically important pests of agricultural crops in much of the eastern and central United States. O. nubilalis is particularly damaging to sweet peppers (Capsicum annuum L.) because it causes direct injury to the fruit, premature fruit ripening, and fruit rot,(More)
Assoc. Editor's note: Consideration of family relationships, particularly between crops and weeds is important for disease and weed management, regardless of production methodology being used. Knowing which family a plant belongs to can be useful in making decisions about crop rotations for managing pests and soil fertility. Plants that are in a family are(More)
Asparagus will grow well on a sandy loam soil or a heavier soil, as long as it drains well. Try to enrich the soil as much as you can before planting by increasing the organic matter content. Sudax can be seeded and let grow throughout the summer and mowed several times to build up soil organic matter, and then plowed under in the fall. Asparagus should be(More)