Past and Present Forest Composition and Natural History of Deep Woods, Hocking County, Ohio

Author Institution: Department of Environmental and Plant Biology, Ohio UniversityDeep Woods, a 114-ha private preserve in Hocking County, OH, is the site of an all taxa biotic inventory (ATBI) coordinated by the Ohio Biological Survey. Here we describe the forest vegetation and natural history of the site and evaluate the role of human disturbance in structuring the regional landscape. Due to various abiotic factors, the area offers a diversity of habitats and species. The bedrock geology consists of sedimentary rock from the Mississippian and Pennsylvanian formations with alluvial deposits along a riparian corridor. At least three soil orders are represented: alfisols, inceptisols, and ultisols. As is typical of most of unglaciated Ohio, the forests here have been subjected to a long history of anthropogenic disturbance. The first inhabitants of the area were ancient moundbuilders (ca. 2500 YBP). During the 1700s, Shawnee and Delaware groups resided throughout the county. Anglo settlers drove all Native American groups out of the area by the early 1800s. The original land survey data (1801) suggested that the dominant vegetation at Deep Woods was composed of Quercus alba, Q. velutina, Carya spp., and Cornus florida (relative importance value, RIV = 34, 13, 12, 11%, respectively). Tax records show that Anglo-ownership of the property dates from the mid-1830s. County death records indicate occupations of 19th century landowners primarily as farmers. Dominant vegetation types include: hydric floodplain, mesic upland, and xeric ridgetop. Betula nigra, Carpinus caroliniana, Ulmus americana, andLiriodendron tulipifera (RIV = 16, 11, 11, 10%) dominate the floodplain. Whereas L. tulipifera, Acer saccharum, andB. alleghaniensis (RIV = 21, 15, 11%) and A rubrum, Q. prinus, and Q. alba (RIV= 27, 13, 9%) dominate the upland and ridgetop, respectively. Several other minor habitats also exist such as pasture fields, hemlock ravines, sandstone outcrops, and rockhouse formations. We conclude that the present species composition resembles the 1801 land survey, even though the post settlement disturbances were different than Native American disturbance regimes

Exclusive Photoproduction of the Cascade (Xi) Hyperons

We report on the first measurement of exclusive Xi-(1321) hyperon photoproduction in gamma p --> K+ K+ Xi- for 3.2 < E(gamma) < 3.9 GeV. The final state is identified by the missing mass in p(gamma,K+ K+)X measured with the CLAS detector at Jefferson Laboratory. We have detected a significant number of the ground-state Xi-(1321)1/2+, and have estimated the total cross section for its production. We have also observed the first excited state Xi-(1530)3/2+. Photoproduction provides a copious source of Xi's. We discuss the possibilities of a search for the recently proposed Xi5-- and Xi5+ pentaquarks.Comment: submitted to Phys. Rev.

The vascular flora of an old-growth mixed mesophytic forest in southeastern Kentucky

Because the goal of natural areas management is often the preservation of biodiversity, documenting botanical species richness is critically important. We con ducted a series of botanical surveys in Big Everidge Hollow, a 52 ha watershed containing old-growth forest, on the Cumberland Plateau of eastern Kentucky. We contrasted our findings with a floristic survey that included parts of our study area, conducted approximately 20 years prior. Our research, from 1999 through 2001, yielded 263 species from 176 genera and 82 families, including 19 species that were new records from the site. These new species may have been overlooked in the previous study because of their scarcity or highly cryptic taxonomy, or they may have established in the years between studies. Of the 263 species recorded in our surveys, only one is considered non-native. This remarkable absence of exotic species indicates the high levels of ecological integrity inherent the study site and suggests an increasingly vital role for old-growth forests as reference ecosystems

Genetic and cellular evidence of vascular inflammation in neurofibromin-deficient mice and humans

Neurofibromatosis type 1 (NF1) results from mutations in the NF1 tumor suppressor gene, which encodes the protein neurofibromin. NF1 patients display diverse clinical manifestations, including vascular disease, which results from neointima formation and vessel occlusion. However, the pathogenesis of NF1 vascular disease remains unclear. Vessel wall homeostasis is maintained by complex interactions between vascular and bone marrow–derived cells (BMDCs), and neurofibromin regulates the function of each cell type. Therefore, utilizing cre/lox techniques and hematopoietic stem cell transplantation to delete 1 allele of Nf1 in endothelial cells, vascular smooth muscle cells, and BMDCs alone, we determined which cell lineage is critical for neointima formation in vivo in mice. Here we demonstrate that heterozygous inactivation of Nf1 in BMDCs alone was necessary and sufficient for neointima formation after vascular injury and provide evidence of vascular inflammation in Nf1+/– mice. Further, analysis of peripheral blood from NF1 patients without overt vascular disease revealed increased concentrations of inflammatory cells and cytokines previously linked to vascular inflammation and vasoocclusive disease. These data provide genetic and cellular evidence of vascular inflammation in NF1 patients and Nf1+/– mice and provide a framework for understanding the pathogenesis of NF1 vasculopathy and potential therapeutic and diagnostic interventions

Exclusive Rho0 Meson Electroproduction from Hydrogen at CLAS

The longitudinal and transverse components of the cross section for the ep --> e' prho(0) reaction were measured in Hall B at Jefferson Laboratory using the CLAS detector. The data were taken with a 4.247 GeV electron beam and were analyzed in a range of x(B) from 0.2 to 0.6 and of Q(2) from 1.5 to 3.0 GeV2. The data are compared to a Regge model based on effective hadronic degrees of freedom and to a calculation based on Generalized Parton Distributions. It is found that, at our lowest x(B) values, the transverse part of the cross section is well described by the former approach while the longitudinal part can be reproduced by the latter

Survey of A_LT' Asymmetries in Semi-Exclusive Electron Scattering on 4He and 12C

Single spin azimuthal asymmetries A(LT') were measured at Jefferson Lab using 2.2 and 4.4 GeV longitudinally polarised electrons incident on He-4 and C-12 targets in the CLAS detector. ALT' is related to the imaginary part of the longitudinal-transverse interference and in quasifree nucleon knockout it provides an unambiguous signature for final state interactions (FSI). Experimental values of ALT' were found to be below 5 %, typically \A(LT')\ less than or equal to 3 % for data with good statistical precision. Optical model in eikonal approximation (OMEA) and relativistic multiple-scattering Glauber approximation (RMSGA) calculations are shown to be consistent with the measured asymmetries. (C) 2004 Elsevier B.V. All rights reserved

Onset of Asymptotic Scaling in Deuteron Photodisintegration

We investigate the transition from the nucleon-meson to the quark-gluon description of the strong interaction using the photon energy dependence of the d(gamma,p)n differential cross section for photon energies above 0.5 GeV and center-of-mass proton angles between 30degrees and 150degrees. A possible signature for this transition is the onset of cross-section s(-11) scaling with the total energy squared, s, at some proton transverse momentum P-T. The results show that the scaling has been reached for proton transverse momentum above about 1.1 GeV/c. This may indicate that the quark-gluon regime is reached above this momentum

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Measurement of two- and three-nucleon short-range correlation probabilities in nuclei

The ratios of inclusive electron scattering cross sections of 4He, 12C, and 56Fe to 3He have been measured at 1 \u3c xB \u3c. At Q2 \u3e 1.4 GeV2, the ratios exhibit two separate plateaus, at 1.5 \u3c xB \u3c 2 and at xB \u3e 2.25. This pattern is predicted by models that include 2- and 3-nucleon short-range correlations (SRC). Relative to A = 3, the per-nucleon probabilities of 3-nucleon SRC are 2.3, 3.1, and 4.4 times larger for A = 4, 12, and 56. This is the first measurement of 3-nucleon SRC probabilities in nuclei