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Part I - Papers Presented At The 1989 Plant Science Lecture Series

Journal of the Iowa Academy of Science: JIAS

The first six titles in this issue of the Journal of Iowa Academy of Science are papers presented at the 1989 edition of the Plant Science Lecture Series held annually at Iowa State University. This lecture series focuses each year on some aspect of plant biology, and each series is composed of six to eight seminars related to a theme that is selected to be timely and related to improvement of field, forage, forest and horticultural crops.

Regulation Of Phytochrome Gene Expression, J. T. Colbert, S. A. Costigan, P. Avissar, Z. Zhao

Journal of the Iowa Academy of Science: JIAS

In etiolated oat seedlings exposure to red light results in a decrease in the transcription of the phytochrome genes, the abundance of phytochrome mRNA, and the level of phytochrome protein. Phytochrome itself serves as the photoreceptor for the response of decreased mRNA and transcription levels. The decrease in phytochrome mRNA is sensitive to low levels of Pfr. Even green "safelight" is capable of inducing a decrease in phytochrome mRNA abundance. Barley phytochrome mRNA abundance is also dramatically down-regulated in response to red light but other plant species vary in their ability to decrease phytochrome mRNA abundance after red light treatment. …

The Axr1 Mutation Of Arabidopsis Is Expressed 10 Booth Roots And Shoots, Cythia Lincoln, Mark Estelle

Journal of the Iowa Academy of Science: JIAS

In order to identify genes involved in auxin action we have isolated a number of mutants of Arabidopsis thaliana which are resistant co exogenous application of either indole-3-acetic acid or 2, 4-dichlorophenoxyacecic acid. One of the genes identified in chis way is the Axr1 gene. Recessive mutations in this gene confer resistance co auxin as well as a number of morphological defects. In this report we describe the isolation of at least two new axr1 alleles. In addition, we show that the axr1 mutation affects gravitropic growth of the root, auxin-induced ethylene biosynthesis and growth in tissue culture. Our results …

A Study Of Sphacelotheca Occidentalis, Cause Of Kernel Smut Of Big Bluestem, Karen M. Snetselaar, Lois H. Tiffany

Journal of the Iowa Academy of Science: JIAS

Sphacelotheca occidentalis causes kernel smut disease of Andropogon gerardii, a prairie grass. The smut fungus is systemic, perennial, causes severe stunting, and sporulates in florets. Spores develop in gall-like sari composed of grass and fungal cells. Spores initiate in a meristematic area near the base of the sorus, and progressively more mature spores are found toward the sorus rip. The cylindrical sari have a central columella of host vascular tissue permeated by hyphae, sporogenous hyphae and developing teliospores that surround the columella, and a peridium of host and fungal cells. Sporogenous hyphae ramify in a gelatinous matrix that disappears as …

Editorial Board & Iowa Academy Of Science Officers And Directors

Journal of the Iowa Academy of Science: JIAS

No abstract provided.

Back Cover

Journal of the Iowa Academy of Science: JIAS

No abstract provided.

Iowa's Climate As Projected By The Global Climate Model Of The Goddard Institute For Space Studies For A Doubling Of Atmospheric Carbon Dioxide, E. S. Takle, S. Zhong

Journal of the Iowa Academy of Science: JIAS

Results of a global climate model that simulates climate under a doubling of atmospheric carbon dioxide (estimated to occur by the latter half of the twenty first century) have been interpolated to Iowa. Summer temperatures under such a doubling are projected to rise by 4 to 7°F (2.2 to 3.9°C) and winter temperatures by 10 to 11° (5.6 to 6.1°C). Estimates of space heating and cooling demands from these data suggest a 30 to 35% decrease in space heat demand and a 200 to 300% increase in space cooling demand. Temperature variability is projected to decrease. Precipitation estimates from global …

Comparison Of Dinitrogen Fixation And Nitrogen Transfer Potentials Of Four Red Clover Cultivars, D. E. Farnham, A. P. Mallarino, W. F. Wedin, I. T. Carlson

Journal of the Iowa Academy of Science: JIAS

The capacity to fix atmospheric N₂ and thus reduce the use of N fertilizer is an important reason for including legumes in forage mixtures. Selection for more efficient N₂ fixation could improve red clover (Trifolium prateme L.) (RC) production and its contribution to soil fertility. An isotope dilution study was conducted in two greenhouse experiments to compare the N₂ fixation and N transfer potentials of three commercial and one experimental RC cultivars. The experimental cultivar APR-8701 was selected for traits related to increased N₂ fixation (rate of acetylene reduction, root size and branch number, and nodule …

Annual Report Of The Iowa Academy Of Science, 1990-91, Paul E. Rider

Journal of the Iowa Academy of Science: JIAS

Starting in 1976, annual reports have served as a continuing record of the activities of the Iowa Academy of Science. These augment a 100 year history of the Academy which was written in the centennial year of 1975.

This report covers the period from July 1, 1990 to June 30, 1991. It is based on the official records of the Academy (committee reports, Board minutes, correspondence) as well as the recollections, impressions and musings of the author.

An Annotated Checklist Of The Vascular Plant Flora Of Guthrie County, Iowa, Dean M. Roosa, Lawrence J. Eilers, Scott Zager

Journal of the Iowa Academy of Science: JIAS

The known vascular plant flora of Guthrie County, Iowa, based on field, herbarium, and literature studies, consists of 748 taxa (species, varieties, and hybrids), 135 of which are naturalized. Species which appear on the state's list of endangered and threatened species, or are otherwise rare, are discussed.

There is an affinity of the plants of Guthrie County with those of the Ozark plateau, and with specialized habitats providing extensions of ranges for species normally found farther north or east.

Implementing A Neural Network In The Smalltalk Graphical Environment, John M. Damgaard

Presidential Scholars Theses (1990 – 2006)

Interest in artificial neural networks has grown rapidly over the past few years. The technology is intriguing and the potential applications of the technology are exciting and diverse. Another area of growing interest in the computer science field is that of object-oriented programming. The object-oriented paradigm is a very powerful tool which can improve software quality and streamline the development process. The most common object-oriented language is Smalltalk. I feel that Smalltalk is an excellent platform on which to implement artificial neural networks.

Spatial And Temporal Distribution Of Hydrogen Peroxide In The Equatorial Pacific Ocean, Renee Blanchard

Honors Theses

The concentration of hydrogen peroxide in the Equatorial Pacific was determined fluorometrically using the horseradish peroxidase catalyzed dimerization of (p-hydroxyphenyl)acetic acid. Vertical profiles were obtained between 9 ON and 3 oS on a longitudinal transect along 140 oW during June and July of 1990 on the RN Wecoma. Peroxide concentrations ranged from 25-80 nmol/L at the surface and decreased to the detection limit of 1 nmol/L at a depth of about 200 meters. Diel variations of hydrogen peroxide in the surface waters were observed over the period of 8 days. The variation in surface concentration may be attributed to the …

A Study Of Periphyton, Sediment And Diatom Community Structure As Monitors Of Heavy Metal Pollution In The Embarras River And Brushy Fork, David L. Vaultonburg

Masters Theses

The purpose of this study was to evaluate periphyton (diatom) and sediment heavy metal content and diatom community structure as potential monitors of heavy metal pollution in the upper reaches of the Embarras River system. The study was initiated due to recent industrialization in the area which could potentially contribute to the present heavy metal burden of Brushy Fork and the Embarras River. These streams are already subject to agricultural runoff, wastewater plant effluent, landfill leachate and other miscellaneous urban and highway runoff. The Embarras River system drains an area of approximately 2800 square miles in 11 east-central Illinois counties …

The Diet And Feeding Habits Of The Southern Stingray, Dasyatis Americana, In Tropical Shallow Marine Habitats, David S. Gilliam

HCNSO Student Theses and Dissertations

The diet and feeding habits of the southern stingray, Dasyatis americana, were investigated through aerial surveys, land-based observations, and quantitative analysis of stomach contents. The field research was conducted in the Exuma Cays Land and Sea Park, central Bahamas. Systematic aerial surveys and the land-based observations were made to determine population density and feeding periodicity in terms of time or tidal phase. In August, 1989, systematic surveys were flown over two cays in the Park; a 12 km² area around Waderick Wells Cay and a 21km² area around Shroud Cay. Both survey areas were flown three times …

Aspects Of Sporinite Chemistry, Michael A. Kruge, John C. Crelling, Edwin J. Hippo, Stephen R. Palmer

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

With the recent advent of the ability to separate coal into maceral concentrates of high purity, the individual constituents of coal can now be analyzed separately, without their mutual interference, giving a much better understanding of the macromolecular structure of coal. The sporinites from two Pennsylvanian age coal samples (Illinois Basin, U.S.A.) were studied, one from a vitrinite-rich high-volatile bituminous coal, the other from a liptinite-rich high-volatile bituminous coal of slightly higher rank. Sporinites were isolated from each coal by density gradient centrifugation. The sporinite of the vitrinite-rich coal was compared chemically and petrographically with the parent coal and with …

Winter 1991, Nsu Oceanographic Center

Currents

No abstract provided.

Spring 1991, Nsu Oceanographic Center

Currents

No abstract provided.

Summer 1991, Nsu Oceanographic Center

Currents

No abstract provided.

Fall 1991, Nsu Oceanographic Center

Currents

No abstract provided.

Vascular Flora Of Arend's Kettle, Freda Haffner Kettlehole State Preserve, Dickinson County, Iowa, Edwin L. Freese, William J. Platt

Journal of the Iowa Academy of Science: JIAS

Arend's Kettle is a 5 ha glacial landform in Dickinson County, Iowa. The flora of this kettle was studied over two years prior to acquisition by the Nature Conservancy in 1973. The known vascular flora of Arend's Kettle as of 1973 consisted of 299 species, representing 177 genera and 59 families. The vegetation ranged from xeric short grass prairie along the rims of the kettle to mesic prairie along the middle and lower slopes. In the bottom of the kettle, there was a marsh/seasonal pond community that varied greatly in the amount of water present, depending on rainfall within the …

Drop-Box Technique For Quantitative Sampling Of Macrofauna And Aquatic Plants At Restored And Natural Wetlands, J. Douglas Oliver, Andrew J. Leslie, William M. Bartodziej

Faculty Publications and Presentations

No abstract provided.

Slope Effects On Shortwave Radiation Components And Net Radiation: Interim Report For Period April 1, 1991- December 31, 1991, E. A. Walter-Shea, B. L. Blad, C. J. Hays, M. A. Mesarch

School of Natural Resources: Documents and Reviews

No abstract provided.

The Pangaean Megamonsoon- Evidence From The Upper Triassic Chinle Formation, Colorado Plateau, Russell F. Dubiel, Judith Totman Parrish, J. Michael Parrish, Steven C. Good

United States Geological Survey: Staff Publications

The Upper Triassic Chinle Formation was deposited at an exceptional time in Earth's paleogeographic and paleoclimatic history. During the Triassic, the supercontinent Pangaea was at its greatest size, in terms of both aggregated continental crust and exposed land area. Moreover, the exposed land was divided symmetrically about the paleoequator between the northern and south- ern hemispheres. These conditions were ideal for maximizing monsoonal circulation, as predicted from paleoclimate models. The Chinle was deposited between about 5° to 15° N paleolatitude in the western equatorial region of Pangaea, a key area for documenting the effects of the monsoonal climate. This study …

Observations Of The Phytoplankton Standing Crop At The Shelf Margin Of The Mid Atlantic Bight, Bruce B. Wagoner, Harold G. Marshall

Biological Sciences Faculty Publications

A comparison of the total percentage cell abundance and cell biovolume relationships of major phytoplankton categories was made between two station sets across the shelf margin. Diatom values for abundance and biovolume were greater at oceanic stations compared to the outer shelf stations, with dinoflagellates having the reverse pattern. The composite contributions to biovolume and abundance in the standing crop from other phytoplankton categories were greater over the outer shelf than beyond the shelf margin. The major source of biovolume (biomass) from the outer shelf and these oceanic stations came from the diatoms and dinoflagellates, with an average mean of …

Distribution Of Terrestrially Derived Dissolved Organic Matter On The Southeastern United States Continental Shelf, Mary Ann Moran, Lawrence R. Pomeroy, Edward S. Sheppard, Larry P. Atkinson, Robert E. Hodson

CCPO Publications

Dissolved lignin-derived compounds in seawater indicate the presence of organic matter originating from vascular plants and therefore from terrestrial (upland and coastal marsh) ecosystems. We used a hydrophobic resin to concentrate lignin-rich humic substances and to determine concentrations of lignin oxidation products (vanillyl lignin phenols) for waters of the continental shelf of the southeastern U.S. Lignin phenol concentrations ranged from 0.05 to 4.2µg liter‒1 and accounted for 0.002–0.13% of the total dissolved organic carbon (DOC) pool in continental shelf waters. Dissolved lignin concentrations were generally highest near the shore and in those areas receiving greatest river and marsh …

Nebraska Summary S111: Lamborghini 115v Dt Also White 6105c And 6105ca, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

Nebraska Summary: S125 Massey Ferguson 3670, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

Nebraska Summary: S120 Ford Versatile 946, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

Nebraska Summary: S111 Lamborghini 115 Vdt, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

Nebraska Summary: S103 Ford 3930 8x8, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …