Forest Decline and Tree Mortality in a Southeastern Ohio Oak-Hickory Forest

Author Institution: Department of Environmental and Plant Biology, Ohio UniversityMany forests throughout the central Appalachians have been suspected, or observed, to be in declining health. Few studies have examined the vitality of southeastern Ohio's forests. The purpose of our study was to evaluate the health of a representative southeastern Ohio oak-hickory forest. Thirty-two 0.1 ha plots were sampled in August 1995 on the 550 ha Waterloo Wildlife Experiment Station (ODNR) in Athens County, OH. Data were collected for all living and dead stems with a DBH >10 cm (1,891 stems sampled). For living trees, a decline index (DI) was determined to evaluate the percentage of branch dieback, undersized leaves, and chlorosis. Dead trees were identified and categorized by mortality class (log vs. snag). Quercus spp. and Carya spp. accounted for 68% of all stems sampled (83% living). Among the live trees, only three species (Juglans nigra, Sassafras albidum, and Cornus florida) exhibited nonhealthy DI values. All other species were observed to be healthy or exhibiting only trace symptoms of decline. In contrast to decline, high mortality was observed for S. albidum (29.1%), Liriodendron tulipifera (21.7%), and Prunus serotina (21.6%). Quercus spp. (17.0%), and Carya spp. (16.2%) exhibited moderate mortality. Acer spp. had the highest vitality among the dominant species. Most of the observed patterns can be explained by successional dynamics and known pathogenic processes. Various incongruities emphasize the need for long-term studies of forest dynamics and forest health monitoring

Server-based and server-less BYOD solutions to support electronic learning

Over the past 10 years, bring your own device has become an emerging practice across the commercial landscape and has empowered employees to conduct work-related business from the comfort of their own phone, tablet, or other personal electronic device. Currently in the Department of Defense, and specifically the Department of the Navy, no viable solution exists for the delivery of eLearning content to a service member's personal device that satisfy existing policies. The purpose of this thesis is to explore two potential solutions: a server-based method and a server-less method, both of which would allow Marines and Sailors to access eLearning course material by way of their personal devices. This thesis will test the feasibility and functionality of our server-based and server-less solutions by implementing a basic proof of concept for each. The intent is to provide a baseline from which further research and development can be conducted, and to demonstrate how these solutions present a low-risk environment that preserves government network security while still serving as a professional military education force multiplier. Both solutions, while demonstrated with limited prototypes, have the potential to finally introduce bring your own device into the Department of the Navy's eLearning realm.http://archive.org/details/serverbasedndser1094549343Captain, United States Marine CorpsCaptain, United States Marine CorpsApproved for public release; distribution is unlimited

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

Effect of Salinity and Waterlogging on Growth and Survival of Salicornia europaea L., and Inland Halophyte

Author Institution: Department of Environmental and Plant Biology, Ohio UniversitySalicornia europaea seedlings were exposed to various salinity and water depths for 11 weeks under controlled, growth chamber conditions. Weekly measurements were made of height, number of nodes, and number of branches per plant. Growth and survival of plants grown with the addition of NaCl were significantly greater (P 0.05) growth differences among plants under different water level conditions within the salt treatment group, plants which were grown without NaCl demonstrated significant decreases in growth in higher water levels, with the greatest growth occurring in the low water treatment group. All plants given a salt treatment survived until the end of the experiment. However, high mortality occurred among the plants that were not salt-treated, with all plants grown under waterlogged conditions dying by week six. The high mortality exhibited by this treatment group indicates that Salicornia, which is typically found in low marsh or inland salt marsh situations, was unable to overcome the combined stress of being continuously waterlogged in a freshwater environment

Chlamydophila (Chlamydia) pneumoniae promotes Ab 1-42 amyloid processing in Neuronal Cells: A Pathogenic Trigger for Alzheimer\u27s Disease

Background: Previously, our laboratory identified Chlamydophila (Chlamydia) pneumoniae (Cpn) in autopsied sporadic AD brains. Furthermore, we have developed a BALB/c mouse model that demonstrated infection-induced amyloid plaques similar to those found in AD, and demonstrated that Cpn infection of neuronal cells inhibited apoptotic pathways of cell death. Hypothesis: Our current studies address whether infection with Cpn in neuronal cells triggers abnormal cleavage of the beta amyloid precursor protein (bAPP) into Ab1-42, thereby contributing to amyloid plaque formation characteristic of the pathology identified in AD. Materials and Methods: Human neuroblastoma cells were infected with the respiratory strain AR39 Cpn in vitro, then amyloid processing was analyzed and quantitated using immunocytochemistry, Western blotting and ELISA assays. Results: Cpn was shown to infect neuronal cells and induce intracellular amyloid processing. Cpn infection yielded cytoplasmic labeling of Ab 1-42 that was increased relative to uninfected cells. The ELISA assay revealed that in neuronal cell lysates, Ab 1-42 in the infected cells was increased 3 to 16-fold over the uninfected cells, from 24 to 72hr post infection. Western blot analysis confirmed an increase in Ab 1-42 in the infected neuronal cell lysates. Conclusions: These data suggest that infection of neuronal cells with Chlamydophila (Chlamydia) pneumoniae alters the processing of bAPP, thereby producing Ab1-42. Therefore, these studies and previous research reported by our laboratory support the implication of Cpn as a pathogenic agent in perpetuating the hallmark amyloid plaque formations observed in AD. This concept holds major therapeutic considerations for future studies.https://digitalcommons.pcom.edu/posters/1004/thumbnail.jp

Electrically Conductive CNT Composites at Loadings below Theoretical Percolation Values

The article of record as published may be found at https://doi.org/10.3390/nano9040491It is well established that dramatic increases in conductivity occur upon the addition of conductive filler materials to highly resistive polymeric matrices in experimental settings. However, the mechanisms responsible for the observed behavior at low filler loadings, below theoretical percolation limits, of even high aspect ratio fillers such as carbon nanotubes (CNT) are not completely understood. In this study, conductive composites were fabricated using CNT bundles dispersed in epoxy resins at diverse loadings, using different dispersion and curing protocols. Based on electron microscopy observation of the CNTs strands distribution in the polymeric matrices and the corresponding electrical conductivities of those specimens, we concluded that no single electron transfer model can accurately explain the conductive behavior for all the loading values. We propose the existence of two different conductive mechanisms; one that exists close to the percolation limit, from ‘low loadings’ to higher CNT contents (CNT % wt > 0.1) and a second for ‘extremely low loadings’, near the percolation threshold (CNT % wt < 0.1). The high conductivity observed for composites at low CNT loading values can be explained by the existence of a percolative CNT network that coexists with micron size regions of non-conductive material. In contrast, samples with extremely low CNT loading values, which present no connectivity or close proximity between CNT bundles, show an electrical conductivity characterized by a current/voltage dependence. Data suggests that at these loadings, conduction may occur via a material breakdown mechanism, similar to dielectric breakdown in a capacitor. The lessons learned from the data gathered in here could guide future experimental research aimed to control the conductivity of CNT composites

Increasing Invasive Plant Pest Early Detection Through Interagency First Detector Education

The Collaborative and Enhanced First Detector Training program has expanded invasive species detection efforts by teaching participants to scout for, identify, and submit suspect exotic species samples. Workshops were delivered to agriculture professionals, master gardeners, and other Extension audiences. Topics included introduction pathways, regulatory agency procedures, identification of invasive pests or pathogens, monitoring procedures, and sample submission. Survey data indicated the intent of participants to augment detection efforts and the efficacy of Extension workshops in improving participants\u27 perceptions of government agencies. Respondents perceived increases in knowledge related to particular invasive species, identification of potential future invaders, and sample submission. Other implications related to Extension programming on invasive species education are discussed

A Photometric Metallicity Estimate of the Virgo Stellar Overdensity

We determine photometric metal abundance estimates for individual main-sequence stars in the Virgo Overdensity (VOD), which covers almost 1000 deg^2 on the sky, based on a calibration of the metallicity sensitivity of stellar isochrones in the gri filter passbands using field stars with well-determined spectroscopic metal abundances. Despite the low precision of the method for individual stars, we derive [Fe/H] = -2.0 +/-0.1 (internal) +/-0.5 (systematic) for the metal abundance of the VOD from photometric measurements of 0.7 million stars in the Northern Galactic hemisphere with heliocentric distances from ~10 kpc to ~20 kpc. The metallicity of the VOD is indistinguishable, within Delta [Fe/H] < 0.2, from that of field halo stars covering the same distance range. This initial application suggests that the SDSS gri passbands can be used to probe the properties of main-sequence stars beyond ~10 kpc, complementing studies of nearby stars from more metallicity-sensitive color indices that involve the u passband.Comment: 5 pages, 3 figures, Accepted for publication in ApJ Letter

The SEGUE Stellar Parameter Pipeline. IV. Validation with an Extended Sample of Galactic Globular and Open Clusters

Spectroscopic and photometric data for likely member stars of five Galactic globular clusters (M3, M53, M71, M92, and NGC 5053) and three open clusters (M35, NGC 2158, and NGC 6791) are processed by the current version of the SEGUE Stellar Parameter Pipeline (SSPP), in order to determine estimates of metallicities and radial velocities for the clusters. These results are then compared to values from the literature. We find that the mean metallicity () and mean radial velocity () estimates for each cluster are almost all within 2{\sigma} of the adopted literature values; most are within 1{\sigma}. We also demonstrate that the new version of the SSPP achieves small, but noteworthy, improvements in estimates at the extrema of the cluster metallicity range, as compared to a previous version of the pipeline software. These results provide additional confidence in the application of the SSPP for studies of the abundances and kinematics of stellar populations in the Galaxy.Comment: 98 pages, 31 figures; accepted for publication in A

The Case for the Dual Halo of the Milky Way

Carollo et al. have recently resolved the stellar population of the Milky Way halo into at least two distinct components, an inner halo and an outer halo. This result has been criticized by Schoenrich et al., who claim that the retrograde signature associated with the outer halo is due to the adoption of faulty distances. We refute this claim, and demonstrate that the Schoenrich et al. photometric distances are themselves flawed because they adopted an incorrect main-sequence absolute magnitude relationship from the work of Ivezi\'c et al. When compared to the recommended relation from Ivezi\'c et al., which is tied to a Milky Way globular cluster distance scale and accounts for age and metallicity effects, the relation adopted by Schoenrich et al. yields up to 18% shorter distances for stars near the main-sequence turnoff (TO). Use of the correct relationship yields agreement between the distances assigned by Carollo et al. and Ivezi\'{c} et al. for low-metallicity dwarfs to within 6-10%. Schoenrich et al. also point out that intermediate-gravity stars (3.5 <= log g <= 4.0) with colors redder than the TO region are likely misclassified, with which we concur. We implement a new procedure to reassign luminosity classifications for the TO stars that require it. New derivations of the rotational behavior demonstrate that the retrograde signature and high velocity dispersion of the outer-halo population remains. We summarize additional lines of evidence for a dual halo, including a test of the retrograde signature based on proper motions alone, and conclude that the preponderance of evidence strongly rejects the single-halo interpretation.Comment: 46 pages, 2 tables, 15 figures, Accepted for publication in the Astrophysical Journa