Ohio Journal of Science: Volume 104, Issue 4 (September, 2004)

Permanent URI for this collection

Front Matter
pp. 0
Article description | Article Full Text PDF (63KB)

Description of Vegetation of the Oak Openings of Northwestern Ohio at the Time of Euro-American Settlement
Brewer, Lawrence G.; Vankat, John L. pp. 76-85
Article description | Article Full Text PDF (107KB)

Gastropods and Rostroconchs (Mollusca) from the Maxville Limestone (Upper Mississippian) in Ohio
Hoare, Richard D. pp. 86-92
Article description | Article Full Text PDF (89KB)

Ultrastructure of the Chorion of Echthistus cognatus (Loew, 1849) (Diptera, Asilidae)
Candan, Selami; Suludere, Zekiye; Kalender, Yusuf; Eryilmaz, Ozlem pp. 93-96
Article description | Article Full Text PDF (85KB)

Economic Performance of Ohio's 88 Counties
Janson, Richard W.; Krishna, Lala B.; Steiner, Richard P. pp. 97-100
Article description | Article Full Text PDF (23KB)

Paleomagnetic Determination of the Age of the Serpent Mound Structure
Watts, D. R. pp. 101-108
Article description | Article Full Text PDF (75KB)

Browse

Recent Submissions

Now showing 1 - 6 of 6
  • Item
    Paleomagnetic Determination of the Age of the Serpent Mound Structure
    (2004-09) Watts, D. R.
    The Serpent Mound structure is a deeply eroded ancient impact in south central Ohio, about 8.0 km across. The age of the structure is poorly constrained by the geology. It post-dates the Lower Mississippian (ca.330 Ma) Cuyahoga Formation and predates Illinoisian glacial deposits. We analyzed the directions of magnetization of 60 rock samples taken from borehole cores drilled within and in the vicinity of the structure using thermal and alternating field demagnetization. The samples were not oriented in azimuth but bedding planes were prominent allowing magnetic inclinations to be determined before and after a tilt correction. Silurian and Ordovician carbonates yielded random results. Lower Silurian Brassfield Formation samples typically have two components of magnetization. A low temperature magnetization with steep inclination that is likely a recent magnetization parallel to the present field is removed from a subset of samples at the earliest stages of treatment. Assuming the low temperature magnetization is parallel to the present field, we can show for these samples that the high temperature magnetization is of reversed polarity. A high unblocking temperature, reversed polarity magnetization has lowest dispersion (k = 138, mean inclination = -1° ± 6.3°) prior to tilt correction, and greatest dispersion (k = 35) after tilt correction, indicating that it was acquired after the structure was formed. From the inclination alone, we estimate the age of magnetization as 256 + 15/-12 Ma. This means the impact responsible for the Serpent Mound structure most likely occurred prior to 256 Ma and after 330 Ma.
  • Item
    Economic Performance of Ohio’s 88 Counties
    (2004-09) Janson, Richard W.; Krishna, Lala B.; Steiner, Richard P.
    The value added by the work force varies greatly among Ohio’s 88 counties. In the aggregate, the value added equals the gross domestic products (GDP) of the county. With an adjustment for depreciation, the value added by the county production system is equivalent to the aggregated real income (Y) of the county, the best measure of county economic performance. Measuring GDP or Y by aggregating all production of a region is a labor-intensive procedure. The purpose of this paper was to see if data on investment in real capital resources within the county and investment in human resources within the county (education) could be used to estimate domestic income without requiring a production census. Aggregated county income in Ohio was predicted reliably using county-specific data on the current value of taxable real property (investment in non-human resources), and the estimated value of the investment in educational attainment by the non-degreed work force of the county (human resources). A data vector for investment in the degreed work force was also used in the analysis. All vectors include values for the exhaustive set of Ohio’s 88 counties. A total of 9 regressions were computed using various combinations of the data. Using established statistical criteria the regression equation that uses investment in real capital and investment in the non-degreed work force was selected as the best method. These criteria included an R-square in excess of 0.99 and a mean square error that was smallest among the alternative regressions.
  • Item
    Ultrastructure of the Chorion of Echthistus cognatus (Loew, 1849) (Diptera, Asilidae)
    (2004-09) Candan, Selami; Suludere, Zekiye; Kalender, Yusuf; Eryilmaz, Ozlem
    The fine structure of the Echthistus cognatus (Loew 1849) chorion was studied using both transmission (TEM) and scanning electron microscopes (SEM). Females were collected in the field and kept under laboratory conditions. Eggs were individually deposited in cotton batting. They were a light yellow color and elongated in shape after the deposition, with an average length of 1.5 mm and an average width of 0.4 mm. Except for the micropylar region, ridges extend all over the surface of the chorion. Aeropyles with different size and shape were present between ridges. There is a single micropylar opening at one pole of the egg. In the thin section, chorion forms a single layer. Chorionic ridges and sunken area are seen in the section.
  • Item
    Gastropods and Rostroconchs (Mollusca) from the Maxville Limestone (Upper Mississippian) in Ohio
    (2004-09) Hoare, Richard D.
    The gastropod fauna is abundant and more diverse in the Upper Mississippian Maxville Limestone than previously described. Seventeen species, including 6 reported for the first time, are known and fragments of several others indicate a still larger fauna is present. A taxonomic update of earlier work includes the new species Platyceras (Orthonychia) morsei, Stegocoelia (Hypergonia)? jonathanensis, and Acteonina hanseni. Small, poorly preserved specimens of rostroconchs represent the genus Oxyprora.
  • Item
    Description of Vegetation of the Oak Openings of Northwestern Ohio at the Time of Euro-American Settlement
    (2004-09) Brewer, Lawrence G.; Vankat, John L.
    Original land survey notes were used to produce a map of the Oak Openings of northwestern Ohio showing the vegetation at the time of Euro-American settlement (1817-1832). For that period, the area of the Oak Openings was 43% Oak Savanna, 27% Wet Prairie, 23% Oak Woodland, 7% Oak Barrens, and <1% Floodplain Forest. The composition of the tree layer was determined from analysis of records of bearing and line trees recorded by the land surveyors. The tree layer of each of the four major vegetation types was dominated by Quercus alba, with Q. velutina as a subdominant. Quercus palustris was also a subdominant in Oak Barrens and Wet Prairie. Tree density averaged 90 trees/ha in Oak Woodland, 14 in Oak Savanna, 2 in Oak Barrens, and <1 in Wet Prairie. The composition of the shrub and herb layers was estimated based primarily on the literature of the region and our own field research. Today most stands of the four major vegetation types have been eliminated by urbanization and agriculture, or have changed to forests as tree densities increased with the absence of fire and increased soil drainage. Extant Oak Savannas and Oak Woodlands are different in composition from those present at Euro-American settlement.
  • Item
    Front Matter
    (2004-09)