Open Access. Powered by Scholars. Published by Universities.®
- Keyword
-
- Iowa (42)
- Climate change (10)
- Endangered species (9)
- Iowa flora (9)
- Habitat (8)
-
- Conservation (7)
- Amphibians (6)
- Corn (6)
- Distribution (6)
- Introduced species (6)
- Prairie (6)
- Tallgrass prairie (6)
- Agronomic traits (5)
- Biotechnology (5)
- Fens (5)
- Floristics (5)
- Malformations (5)
- Mussels (5)
- Atrazine (4)
- Biodiversity (4)
- Climate variability (4)
- Exotic species (4)
- Invertebrates (4)
- Mammals (4)
- Phasianus colchicus (4)
- Plant communities (4)
- Rana pipiens (4)
- Sorghum bicolor L. Moench (4)
- Zea mays L. (4)
- Alfalfa (3)
- Publication Year
Articles 421 - 450 of 701
Full-Text Articles in Anthropology
Paleokarst And Associated Mineralization At The Linwood Mine, Scott County Iowa, Paul L. Garvin
Paleokarst And Associated Mineralization At The Linwood Mine, Scott County Iowa, Paul L. Garvin
Journal of the Iowa Academy of Science: JIAS
Operations at the Linwood Mine in Scott County, Iowa, have exposed, on two working levels, extensive pre-Pennsylvanian paleokarst and associated sediment fillings and mineralization in Middle Devonian limestones. Cavities in Davenport-Spring Grove host rocks range up to 270 meters in length and are virtually all filled with fluviatile sediment. Cavities in Cedar Rapids host rocks, on average, are smaller and some are unfilled. Limestone dissolution was controlled by high-angle fractures with a wide variety of orientations and by bedding plane and stylolitic partings. Dissolutional features on both levels of the mine provide evidence for phreatic and vadose processes. Most of …
Editorial Board & Iowa Academy Of Science Officers And Directors
Editorial Board & Iowa Academy Of Science Officers And Directors
Journal of the Iowa Academy of Science: JIAS
No abstract provided.
Cover - Table Of Contents
Journal of the Iowa Academy of Science: JIAS
No abstract provided.
Inheritance And Number Of Genes Affecting Quantitative Traits Within F2 Maize Populations, D. H. Schmidt, A. R. Hallauer
Inheritance And Number Of Genes Affecting Quantitative Traits Within F2 Maize Populations, D. H. Schmidt, A. R. Hallauer
Journal of the Iowa Academy of Science: JIAS
Populations derived from crosses of elite genotypes are commonly used in plant breeding programs. Knowledge of the genetic variation among individuals and their progenies within F2 populations is essential for effective selection of important traits. The genetic variation and number of effective factors affecting the expression of quantitative traits within 30 F2 maize (Zea mays L.) populations were determined by different methods suggested for study of F2 populations. Estimates of heritability and number of effective factors varied among F2 populations for each trait, primarily because of the differences in trait expression between parents of crosses and the environmental effects upon …
Editorial Board & Iowa Academy Of Science Officers And Directors
Editorial Board & Iowa Academy Of Science Officers And Directors
Journal of the Iowa Academy of Science: JIAS
No abstract provided.
Selective Recovery Of Β-Galactosidase With Charged Fusion Tails Using Ion-Exchange Membranes, Erika A. Thiem, Meng H. Heng
Selective Recovery Of Β-Galactosidase With Charged Fusion Tails Using Ion-Exchange Membranes, Erika A. Thiem, Meng H. Heng
Journal of the Iowa Academy of Science: JIAS
We explored the feasibility of attaching charged tails to a target protein, in this case β-galactosidase, for selective recovery. In this process, an ion-exchange membrane was used for selective binding and release of β-galactosidase with the attached purification fusions. Strength of binding and purity of eluate increased with increasing tail length. In addition, activity yield was improved with the implementation of an intermediate partial elution recycle procedure.
Research Papers By 1992 And 1993 Interns In The Program For Women In Science And Engineering At Iowa State University, Mary Ann Evans, Krishna S. Athreya
Research Papers By 1992 And 1993 Interns In The Program For Women In Science And Engineering At Iowa State University, Mary Ann Evans, Krishna S. Athreya
Journal of the Iowa Academy of Science: JIAS
The papers in this volume offer a sampling of the outstanding work of high school and undergraduate interns who participated in the 1992 and 1993 Program for Women in Science and Engineering (PWSE) summer internship programs. From synthesis of materials to developing effective methods of hazardous waste disposal, from nondestructive structural studies at the macroscopic level to microstructural analyses of materials, from testing precision of sensors used as aids in agriculture to isolating effects of specific parameters on plant growth, to name a few, these papers span a wide range of scientific methods and disciplines. They serve as testimony to …
Cover - Table Of Contents
Journal of the Iowa Academy of Science: JIAS
No abstract provided.
Cover - Table Of Contents
Journal of the Iowa Academy of Science: JIAS
No abstract provided.
Effects Of Competition And Predation On Prothonotary Warblers And House Wrens Nesting In Eastern Iowa, Timothy Brush
Effects Of Competition And Predation On Prothonotary Warblers And House Wrens Nesting In Eastern Iowa, Timothy Brush
Journal of the Iowa Academy of Science: JIAS
In a fragmented midwestern floodplain forest, a small Prothonotary Warbler (Protonotaria citrea) population experienced high competition with House Wrens (Troglodytes aedon) and mammalian nest predation in 1988-89. Despite the provision of 3 types of nest boxes and higher water levels, Prothonotary Warblers did not nest successfully and decreased in the fragmented forest in 1990-91. House Wrens used >90% of the nest boxes in both years. Wren territories doubled within the nestbox area, while remaining constant on an unmanipulated area. In contrast, a larger warbler population had high nesting success during 1990-91 in a relatively unfragmented, wetter forest tract. Such forests, …
Use Of Ion Exchange Membranes For Selective Recovery Of Aspergillus Awamori Glucoamylase And Phage T4 Lysozyme, Deborah K. Stafslein, Jeff M. Hunter, Craig E. Forney
Use Of Ion Exchange Membranes For Selective Recovery Of Aspergillus Awamori Glucoamylase And Phage T4 Lysozyme, Deborah K. Stafslein, Jeff M. Hunter, Craig E. Forney
Journal of the Iowa Academy of Science: JIAS
Our research examined whether enhanced separation and purification of mutant enzymes could be obtained on ion-exchange membranes. Solutions of three mutants of Aspergillus awamori glucoamylase were passed through an anionic exchange membrane, as well as one mutant of T4 lysozyme through a cationic exchange membrane. The mutant enzymes were modified by adding "charged fusions'', polypeptides of either aspartic acid residues to increase the overall negative charge of the enzyme or arginine residues to increase the overall positive charge. The effect of the mutations on the purification of glucoamylase from a "modified" fermentation broth were examined at two different elution pHs, …
Age And Developmental History Of Iowa Fens, C. A. Thompson, E. A. Bettis Iii
Age And Developmental History Of Iowa Fens, C. A. Thompson, E. A. Bettis Iii
Journal of the Iowa Academy of Science: JIAS
Iowa fens are small, mineorotrophic peatlands maintained by shallow groundwater. Eighteen fen sites located across northern Iowa were mapped and radiocarbon dated to assess the timing of initial peat accumulation. The radiocarbon ages span the Holocene, ranging from 1,240 to 10,900 B.P.; however most fens postdate 5,000 yr B.P. The dominance of late-Holocene ages suggests that Holocene climatic change may have strongly influenced the record of peat accumulation. During the mid-Holocene Iowa was warmer and drier than at present, and peat was degraded or accumulated slowly in fens. The range of ages also implies that the commencement and subsequent rate …
Nomenclatural Changes For Some Diatoms Found In Iowa, David B. Czarnecki
Nomenclatural Changes For Some Diatoms Found In Iowa, David B. Czarnecki
Journal of the Iowa Academy of Science: JIAS
Nomenclatural revisions for four diatom taxa found in Iowa, two of which are presently maintained in the Loras College Freshwater Diatom Culture Collection (FDCC), are necessary because of systematic interpretations of the Division Bacillariophyta. Achnanthidium hauckianum (Grun.) Czarnecki comb. nov. was originally assigned to the genus Achnanthes Bory. Three taxa were previously assigned to the morphologically diverse genus Navicula Bory. These are Cavinula weinzierlii (Schimanski) Czarnecki comb. nov., Craticula cuspidata var. major [(Meist.) Czarnecki comb. nov. and] Craticula halophila var. subcapitata (0str.) Czarnecki comb. nov.
Ecoregions And Subregions Of Iowa: A Framework For Water Quality Assessment And Management, Glenn E. Griffith, James M. Omernik, Thomas F. Wilton, Suzanne M. Pierson
Ecoregions And Subregions Of Iowa: A Framework For Water Quality Assessment And Management, Glenn E. Griffith, James M. Omernik, Thomas F. Wilton, Suzanne M. Pierson
Journal of the Iowa Academy of Science: JIAS
Ecoregion frameworks are valuable tools for inventorying and assessing environmental resources, for setting resource management goals, and for developing biological criteria and water quality standards. In a collaborative project between the Iowa Department of Natural Resources (DNR) and the U.S. Environmental Protection Agency (EPA), we have refined boundaries of the EPA's five ecological regions of Iowa and defined six subregions of the Western Corn Belt Plains ecoregion within the state. Lists of candidate stream reference sites have been developed to date for the seven largest regions, and the sites were visited and evaluated by Iowa DNR and U.S. EPA personnel …
Removal Of Magnetic Impurities From Strontium Copper Oxychloride, Colleen B. Eads, Carol J. Kosmicke, Lance L. Miller
Removal Of Magnetic Impurities From Strontium Copper Oxychloride, Colleen B. Eads, Carol J. Kosmicke, Lance L. Miller
Journal of the Iowa Academy of Science: JIAS
Analyses of a copper-deficient series of Strontium Copper Oxychloride polycrystalline samples are reported. Magnetic susceptibility, X-ray powder diffraction, and differential thermal analyses show a small Curie-type magnetic signal correlates with =0.6% (excess) copper ions in the nominally stoichiometric material. The analyses also imply that the extra magnetic signal is from an impurity phase, possibly related to Strontium Copper Oxide. The concentration of the impurity phase can be controlled by varying the copper stoichiometry.
Nuclear Waste Into Glass: Viscosities Of Molten Analogs Of Radioactive Waste Disposal Media, Betty Pang, Kenneth E. Windom
Nuclear Waste Into Glass: Viscosities Of Molten Analogs Of Radioactive Waste Disposal Media, Betty Pang, Kenneth E. Windom
Journal of the Iowa Academy of Science: JIAS
Disposal of high-level radioactive wastes involves vitrification of a mixture of waste products and borosilicate glass frit. Monitoring the composition of the mixture is critical to the control of the vitrification process, bur is difficult because of the high levels or radioactive components in the mixture. Synthetic non-radioactive analogs of the products from nuclear reprocessing have been prepared and their viscosities measured over a wide range of temperature appropriate to those of the vitrification process. Preliminary results indicate that viscosity is a linear function of composition, under isothermal conditions, for a limited compositional range that encompasses the proportions of waste …
Influence Of Reduced Leaching On Growth Of Seedlings Of Black Locust Inoculated With Rhizobia, William R. Graves, Sandra R. Anfinson
Influence Of Reduced Leaching On Growth Of Seedlings Of Black Locust Inoculated With Rhizobia, William R. Graves, Sandra R. Anfinson
Journal of the Iowa Academy of Science: JIAS
Seedlings of black locust (Robinia pseudoacacia L.) were inoculated with compatible rhizobia and irrigated twice each week with solution containing either 50 or 150 mg nitrogen/L. Leaching fraction treatments of 0, 0.2, or 0.4 were maintained for 6 weeks. Seedlings supplied 50 mg nitrogen/L grew poorly compared co planes supplied 150 mg nitrogen/L regardless of leaching fraction. Dry masses of shoots and of entire planes were lower for seedlings in the 0 and 0.2 leaching fraction treatments compared with chose in the 0.4 treatment. Neither leaching fraction nor applied nitrogen concentration appeared co affect the number of nodules per plant, …
Parallel Algorithms For Solving Partial Differential Equations, Stacy Pschenica
Parallel Algorithms For Solving Partial Differential Equations, Stacy Pschenica
Journal of the Iowa Academy of Science: JIAS
This paper describes the use of a parallel computer system in applying a finite difference method to solve various types of partial differential equations. A sequential implementation of this method was made parallel by essentially spatially decomposing the problem domain into pieces that could be separately analyzed and assigning each piece to a processor in a large, multi-processor system. Although this approach is attractive in theory, it suffers in practice because of inter-processor interactions. Thus, particular emphasis was placed on developing efficient methods for the sharing of information among the processors.
Initially, a simple two-dimensional board game, life, was implemented …
Editorial Board & Iowa Academy Of Science Officers And Directors
Editorial Board & Iowa Academy Of Science Officers And Directors
Journal of the Iowa Academy of Science: JIAS
No abstract provided.
Annual Report Of The Iowa Academy Of Science, 1993-94, Paul E. Rider
Annual Report Of The Iowa Academy Of Science, 1993-94, Paul E. Rider
Journal of the Iowa Academy of Science: JIAS
Since 1976, annual reports have served as a continuing record of the activities of the Iowa Academy of Science and an archive for its history. These augment the 100 year IAS history written in the centennial year of 1975.
This report covers the period from July 1, 1993 to June 30, 1994. It is based on the official records of the Academy (committee reports, Board minutes, correspondence) as well as the recollections, impressions and thoughts of the author.
Editorial Board & Iowa Academy Of Science Officers And Directors
Editorial Board & Iowa Academy Of Science Officers And Directors
Journal of the Iowa Academy of Science: JIAS
No abstract provided.
The Iowa Academy Of Science Parish Farm: 1986-1992, David L. Dozark
The Iowa Academy Of Science Parish Farm: 1986-1992, David L. Dozark
Journal of the Iowa Academy of Science: JIAS
This article focuses on the Iowa Academy of Science Parish Farm and the progress made in the last seven years towards the goals set forth in the Model Farm Concept which was adopted by the Academy in 1970. Highlights of this article are a summary of the income and expenses associated with the farm's highly profitable crop production, the ground-water monitoring project being conducted by the Geological Survey Bureau, the woodlot rejuvenation project, soil and wildlife conservation improvements, and the prairie forbes exhibit area. The farm continues to serve as a primary source of income for the Academy and a …
Analysis Of An Iowa Aridity Index In Relationship To Climate And Crop Yield, Soumare Harouna, R. E. Carlson
Analysis Of An Iowa Aridity Index In Relationship To Climate And Crop Yield, Soumare Harouna, R. E. Carlson
Journal of the Iowa Academy of Science: JIAS
An aridity index and its components, temperature and precipitation, for the period from 1900 through April 1993 were defined and characterized. This index describes the anomalous behavior of both temperature and precipitation over time. Our intent was to examine climate variability in Iowa. Moving mean and standard deviations over various lengths of time were calculated from three time series. We found that these indices fluctuate considerably from year to year and from month to month. The lowest aridity index values occurred in the recent summer of 1992, and the highest occurred during the very drought-prone 1930s. The 12-month moving mean …