1,659 research outputs found
Phemeranthus rugospermus (Holz.) Kiger
https://thekeep.eiu.edu/herbarium_specimens_byname/20846/thumbnail.jp
Viola pedata L.
https://thekeep.eiu.edu/herbarium_specimens_byname/20708/thumbnail.jp
Direction-dependent turning leads to anisotropic diffusion and persistence
Cells and organisms follow aligned structures in their environment, a process that can generate persistent migration paths. Kinetic transport equations are a popular modelling tool for describing biological movements at the mesoscopic level, yet their formulations usually assume a constant turning rate. Here we relax this simplification, extending to include a turning rate that varies according to the anisotropy of a heterogeneous environment. We extend known methods of parabolic and hyperbolic scaling and apply the results to cell movement on micropatterned domains. We show that inclusion of orientation dependence in the turning rate can lead to persistence of motion in an otherwise fully symmetric environment and generate enhanced diffusion in structured domains
Vegetation and Flora of the Sand Deposits of the Mississippi River Valley in Northwestern Illinois
This study was undertaken to determine vascular plant species composition, vegetation structure,
and floristic quality of the major plant communities in the windblown sand deposits of northwestern
Illinois during the growing seasons of 2002 through 2005. The major plant communities of
the Ayers Sand Prairie Nature Preserve in Carroll County, Big River State Forest in Henderson
County, Lost Mound Unit of the Upper Mississippi River Wildlife and Fish Refuge in Carroll and
Jo Daviess counties, and the Thomson-Fulton Sand Prairie Nature Preserve located in Whiteside
County were examined and the importance values determined for the plant species present. Located
on broad terraces of the Mississippi River, these nature preserves and natural areas are remnants
of a larger grassland/savanna/forest complex that contained extensive marsh; wet, mesic, and dry
sand prairie; sand savanna; and sand forest communities. Most of the sand deposits are now cultivated
and the original vegetation is found only in protected remnants, some of which are relatively
large. The mature dry sand prairies were dominated by Schizachyrium scoparium; other important
species were Opuntia macrorhiza, Dichanthelium villosissimum, Ambrosia psilostachya, and
Tephrosia virginiana. Other assemblages of prairie and exotic species were encountered in successional
sand prairie communities. Generally, the mature prairie communities in these preserves and
natural areas had 35 or more species present in the study plots. Savanna and closed canopy forest
communities were also examined. The dry sand savannas were dominated by Quercus velutina and
Q. marilandica, dry sand forests were dominated by Q. velutina, and dry-mesic sand forests were
dominated by Q. alba and Q. velutina.Illinois Department of Natural Resources; Illinois Nature Preserves Commissionpublished or submitted for publicationis peer reviewe
Vascular Flora of Hooper Branch Savanna Nature Preserve, Iroquois County, Illinois
INHS Technical Report prepared for Illinois Department of Natural Resources, Division of
Natural Heritag
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