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Natural Resource Economics Commons

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University of Nebraska - Lincoln

2001

Articles 1 - 2 of 2

Full-Text Articles in Natural Resource Economics

Intermediate Rings Between A Local Domain And Its Completion, Ii, William Heinzer, Christel Rotthaus, Sylvia Wiegand Oct 2001

Intermediate Rings Between A Local Domain And Its Completion, Ii, William Heinzer, Christel Rotthaus, Sylvia Wiegand

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

We present results connecting flatness of extension rings to the Noetherian property for certain intermediate rings between an excellent normal local domain and its completion. We consider conditions for these rings to have Cohen-Macaulay formal fibers. We also present several examples illustrating these results.


Yellow Jackets (Vespula Spp.) Disperse Trillium (Spp.) Seeds In Eastern North America, Jennifer A. Zettler, Timonthy P. Spira, Craig R. Allen Jan 2001

Yellow Jackets (Vespula Spp.) Disperse Trillium (Spp.) Seeds In Eastern North America, Jennifer A. Zettler, Timonthy P. Spira, Craig R. Allen

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Approximately 70 plant families worldwide have ant-dispersed seeds (myrmecochory). In this putative ant-plant mutualism, ants are attracted to and disperse seeds that have a lipid-rich elaiosome. We observed yellow jackets (Vespula spp.) dispersing seeds of three elaiosome-bearing species-Trillium cuneatum, T. undulatum and T catesbaei-in the Blue Ridge Mountains of North Carolina and South Carolina. Moreover, we estimated the mean distance yellow jackets dispersed seeds of T. cuneatum by placing intact fruits on index cards and recovering dispersed seeds on sheets placed on the ground surface. Of the seeds presented, 41% were recovered and the average dispersal distance …