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Full-Text Articles in Life Sciences

'Eve' In Africa: Human Evolution Meets Molecular Biology, Robert D. Seager Mar 1990

'Eve' In Africa: Human Evolution Meets Molecular Biology, Robert D. Seager

Faculty Publications

Recent advances in the study of human origins have increased our understanding of our ancestors. There have been new, major fossil finds. WT 17000, a 2.5 million-year-old robust Australopithecus found in Kenya (Walker et al. 1986), led to a revision of early hominid phylogeny (Delson 1986; 1987). Existing fossil materials have been reassessed. For example, Tattersall (1986) maintains that at least two unrecog­- nized hominid species (Homo neanderthalensis, H. hei­ delbergensis and possibly H. steinheimensis ) existed be­ tween the times of H . erectus and fully modern H . sapiens.


Anatomical Characterization Of Western Corn Rootworm Damage In Adventitious Roots Of Maize, Walter E. Riedell, Alice Y. Kim Jan 1990

Anatomical Characterization Of Western Corn Rootworm Damage In Adventitious Roots Of Maize, Walter E. Riedell, Alice Y. Kim

Journal of the Iowa Academy of Science: JIAS

Corn rootworms are one of the most economically damaging insect pests of maize, yet little is known about the feeding behavior of the larvae. This study was conducted to determine which tissues of the adventitious roots of maize are damaged by western corn rootworm (Diabrotica virgifera virgifera LeConte) larval feeding. Root axes (10 cm long) were removed from the fifth node of greenhouse-grown maize plants. Root segments 2 cm long, excised 4 or 6 cm from the root tip, were infested with second or third stage larvae, respectively, (0, 1, 3, or 6 larvae per segment) for a period of ...


Bibliography Of The Natural And Cultural History Of The Loess Hills Of Iowa, Dean M. Roosa, Darwin D. Koenig Jan 1990

Bibliography Of The Natural And Cultural History Of The Loess Hills Of Iowa, Dean M. Roosa, Darwin D. Koenig

Journal of the Iowa Academy of Science: JIAS

A bibliography of literature on Iowa's Loess Hills includes references containing information on the cultural or natural history of chis western Iowa landform region. The bibliography is divided into six parts: general, archaeological, botanical, geological, historical, and zoological. Annotations are included only where necessary to clarify contents. Because of their rugged topography, the Loess Hills of western Iowa have resisted large-scale conversion to agriculture. This has permitted noteworthy persistence of native prairies and woodlands, along with their associated species. This bibliography complements two special issues of the Proceedings of the Iowa Academy of Science devoted to Iowa's Loess ...


Journal Of The Iowa Academy Of Science Submission Form And Instruction Sheet Jan 1990

Journal Of The Iowa Academy Of Science Submission Form And Instruction Sheet

Journal of the Iowa Academy of Science: JIAS

No abstract provided.


Back Cover Jan 1990

Back Cover

Journal of the Iowa Academy of Science: JIAS

No abstract provided.


Back Cover Jan 1990

Back Cover

Journal of the Iowa Academy of Science: JIAS

No abstract provided.


Cover - Table Of Contents Jan 1990

Cover - Table Of Contents

Journal of the Iowa Academy of Science: JIAS

No abstract provided.


Index For Volume 97 Jan 1990

Index For Volume 97

Journal of the Iowa Academy of Science: JIAS

No abstract provided.


Editorial Board & Iowa Academy Of Science Officers And Directors Jan 1990

Editorial Board & Iowa Academy Of Science Officers And Directors

Journal of the Iowa Academy of Science: JIAS

No abstract provided.


Front Matter Jan 1990

Front Matter

Journal of the Iowa Academy of Science: JIAS

No abstract provided.


Back Cover Jan 1990

Back Cover

Journal of the Iowa Academy of Science: JIAS

No abstract provided.


Cover - Table Of Contents Jan 1990

Cover - Table Of Contents

Journal of the Iowa Academy of Science: JIAS

No abstract provided.


Atmospheric Response To 1988 Drought Conditions And Future Climate Implications, Michael D. Mccorcle Jan 1990

Atmospheric Response To 1988 Drought Conditions And Future Climate Implications, Michael D. Mccorcle

Journal of the Iowa Academy of Science: JIAS

Plentiful precipitation in the central United States is one of the basic components of the successful agricultural industry in the Corn Belt. A combination of moisture, wind, and topographic factors creates an ideal condition for rainfall over most of the region during the late spring and early summer. In 1988, many ingredients necessary for wet weather were absent. The region experienced a drought unequalled since the 1930's. The drought of 1988 demonstrated chat the symptom of drought, namely, dry soils, can exacerbate and even perpetuate drought conditions by decreasing available moisture, altering circulation patterns vital to storm development, and ...


Editorial Board & Iowa Academy Of Science Officers And Directors Jan 1990

Editorial Board & Iowa Academy Of Science Officers And Directors

Journal of the Iowa Academy of Science: JIAS

No abstract provided.


Climate Change And The Potential Impact On The Soil Resource, J. L. Hatfield Jan 1990

Climate Change And The Potential Impact On The Soil Resource, J. L. Hatfield

Journal of the Iowa Academy of Science: JIAS

Climatic change will lead to changes in the carbon dioxide C02, temperature, and precipitation. There have been many predictions of the effect of climatic change on plant growth but none on the soil parameters or water use. To fully understand the implications on soil management from climate change the expected changes in soil temperature, water use, and water and nutrient use efficiency need quantification.


Population Estimates And Geographic Distribution Of The Yellow Mud Turtle (Kinosternon Flavescens) In Iowa, James L. Christiansen, Benny J. Gallaway, John W. Bickham Jan 1990

Population Estimates And Geographic Distribution Of The Yellow Mud Turtle (Kinosternon Flavescens) In Iowa, James L. Christiansen, Benny J. Gallaway, John W. Bickham

Journal of the Iowa Academy of Science: JIAS

The yellow mud turtle (Kinosternon flavescens) is an endangered species in Iowa known from six localities in the stare. The only large population is located on a private preserve on Big Sand Mound in Muscatine and Louisa Countries and is estimated to consist of 2,000 to 3,000 individuals. Following the removal of predators in 1979, density estimates have tripled as estimated by the Sequential Bayes Algorithm of mark-recapture data. Assuming the Big Sand Mound population was nor severely damaged by the drought of 1988, it is judged sufficiently large to serve as a source to enrich certain of ...


Book Review: Fragile Giants: A Natural History Of The Loess Hills, Kenneth D. Carlander Jan 1990

Book Review: Fragile Giants: A Natural History Of The Loess Hills, Kenneth D. Carlander

Journal of the Iowa Academy of Science: JIAS

The Loess Hills, which are a special feature of the eastern bank of the Missouri River in Iowa and northern Missouri, have been cited by Dean Roosa, Iowa's State Ecologist, as a "world treasure and ... our best-kept secret." These Hills are mounds of finely ground soil, "glacial flour," deposited by dust storms after the glaciers receded 31 to 12 thousand years ago. Loess is rather widely distributed in Iowa, but the extensive deposits (often over 200 feet deep) on and against the eastern wall of the valley left a rolling, wave-like, terrain which on erosion leaves vertical banks of ...


Impact Of Global Warming And Cooling On Midwestern Agriculture, Louis M. Thompson Jan 1990

Impact Of Global Warming And Cooling On Midwestern Agriculture, Louis M. Thompson

Journal of the Iowa Academy of Science: JIAS

The global warming since 1980 has been greater than it was during the warming trend from 1880 to 1940. This has caused concern that the very warm years of 1987 and 1988 might have been associated with greenhouse warming. However, the cooling trend from 1940 to 1980 occurred during a rapid buildup in greenhouse gases in the atmosphere. Although there may have been some greenhouse warming since 1880, the unusual warmth of 1987 and 1988 may have been caused by changes in the temperature of the equatorial Pacific Ocean, and changes in transparency of the atmosphere or ocher phenomena acting ...


Characteristics Of Channel Catfish Populations In Streams And Rivers Of Iowa With Varying Habitats, Vaughn L. Paragamian Jan 1990

Characteristics Of Channel Catfish Populations In Streams And Rivers Of Iowa With Varying Habitats, Vaughn L. Paragamian

Journal of the Iowa Academy of Science: JIAS

From 1983 co 1985, more than 1,000 channel catfish (Icatalurus punctatus) were sampled with rotenone from 50 streams and rivers in Iowa to assess differences in population densities, standing stocks, viral statistics, age and growth, and habitat use Catfish densities ranged from 5 fish/ha in sites on the South Skunk and Upper Iowa Rivers to more than 4,400 fish/ha at a site on the Thompson Fork of the Grand River. Standing stocks ranged from a low of 0.1 kg/ha on a site on the South Skunk River to a high of 467 kg/ha ...


Computed Normal Range Of Iowa Statewide July Precipitation, H. C. Vaughan, D. S. Sheets, G. R. White Jan 1990

Computed Normal Range Of Iowa Statewide July Precipitation, H. C. Vaughan, D. S. Sheets, G. R. White

Journal of the Iowa Academy of Science: JIAS

Iowa summer rainfall distributions are examined to identify small-scale anomalies. Examination of extremely wet and dry summer months shows that large rain amounts fall mainly in small, cellular areas for both extremely wet and dry months. These configurations result from individual rainfall events. Analysis of the distribution of mean July rainfall across the state reveals significant anomalous wet and dry regions that contrast with the background, east-west rainfall gradient. Because of the skewed nature of summer rainfall distributions, the median value is used to represent a more realistic expected rainfall amount for any given year. Some parts of the stare ...


A Survey Of The Benthic Macroinvertebrates Of The Big Spring Basin, Iowa, Jack O. Kennedy, John G. Miller Iii Jan 1990

A Survey Of The Benthic Macroinvertebrates Of The Big Spring Basin, Iowa, Jack O. Kennedy, John G. Miller Iii

Journal of the Iowa Academy of Science: JIAS

Benthic macroinvertebrates were collected in the Big Spring Basin, located in northeastern Iowa, from May through October 1988. The purpose of the study was to develop baseline information on the benthic organisms present in the basin. A total of 167 taxa including seven species of leeches, five genera of snails, three genera of clams, one crayfish genus and over 150 taxa of aquatic insects were identified with the majority of the organisms having been reported in Iowa previously. Benthic organisms not usually encountered in Iowa include the planarian, Cura formanii; the isopod, Lirceus; the beedes, Enrxhrus, Hydrophilus, and llybius; the ...


Gene Transfer In Crop Improvement - An Introduction And Overview, Robert M. Goodman Jan 1990

Gene Transfer In Crop Improvement - An Introduction And Overview, Robert M. Goodman

Journal of the Iowa Academy of Science: JIAS

The application of recombinant DNA technology to plant breeding promises important applications in agriculture and advances in many plant science disciplines. Gene transfer at the molecular level can be routinely accomplished in an increasing number of plant species. For many of the world's important crops, new methods or refinements of proven methods will be needed and are being developed. Experience with gene regulation in transgenic plants is accumulating in many laboratories around the world. The action of any particular gene cannot be predicted precisely without reference to the genetic background in which it acts, but, qualitatively speaking, the cis-acting ...


Front Matter Jan 1990

Front Matter

Journal of the Iowa Academy of Science: JIAS

No abstract provided.


Cover - Table Of Contents Jan 1990

Cover - Table Of Contents

Journal of the Iowa Academy of Science: JIAS

No abstract provided.


Climate Trends In Iowa, Richard E. Carlson Jan 1990

Climate Trends In Iowa, Richard E. Carlson

Journal of the Iowa Academy of Science: JIAS

Long-term trends for various weather elements are presented for the period 1900-1988. Summer and winter season, and annual air temperature patterns are statistically weak because of large inrerannual variability, but trends are evident. There was a general warming from 1900 until the 40's, with a leveling or slight cooling following. Since the mid-70's, a warming trend seems to be taking place, but this cannot be confirmed. Spring season air temperatures showed no trend except that the most recent 4 years (1985-1988) were decidedly warmer than normal. Winter season air temperatures showed a change in trend in the 30 ...


The Effect Of Harvesting On Macrophyte Regrowth And Water Quality In Ladue Reservoir, Ohio, G. Dennis Cooke, Angela B. Martin, Robert E. Carlson Jan 1990

The Effect Of Harvesting On Macrophyte Regrowth And Water Quality In Ladue Reservoir, Ohio, G. Dennis Cooke, Angela B. Martin, Robert E. Carlson

Journal of the Iowa Academy of Science: JIAS

Two experiments in a bay of LaDue Reservoir (Geauga Co., northeastern Ohio) during summer, 1985 demonstrated that removal of Eurasian watermilfoil (Myriophyllum spicatum L.) root crowns with an aquatic weed harvester retarded plant regrowth to quantities well below nuisance levels for 28 days. Nearly summer-long control was achieved following a "touch-up" harvest on day 42. In contrast, the harvester was used in this bay in 1982 to "mow" milfoil, leaving intact "stumps." The mowed plants regrew to preharvest and control area biomass levels within 23 days. The difference in plant regrowth between these two methods strongly suggests that user dissatisfaction ...


Front Matter Jan 1990

Front Matter

Journal of the Iowa Academy of Science: JIAS

No abstract provided.


Back Cover Jan 1990

Back Cover

Journal of the Iowa Academy of Science: JIAS

No abstract provided.


Holocene Vegetational Changes In Eastern Iowa, R. G. Baker, C. A. Chumbley, P. M. Witinok, H. K. Kim Jan 1990

Holocene Vegetational Changes In Eastern Iowa, R. G. Baker, C. A. Chumbley, P. M. Witinok, H. K. Kim

Journal of the Iowa Academy of Science: JIAS

Pollen and plant macrofossil analysis from three sites along an east-west transect in southeastern Iowa provide evidence for Holocene vegetational development. Colo Marsh at the west end of the transect is relatively complete, with a late-glacial spruce zone ending about 11,500 yr B.P.; a deciduous forest zone from about 11,500 to 8300; a prairie zone from 8300 to 4500, and prairie with oak from 4500 to presettlement times.

Sediments from the site at the Indian Creek Nature Center, midway in the transect, date only from about 6000 to 1600 yrs B. P. This site also was dominantly ...


Engineering Proteinase Inihibitor Genes For Plant Defense Against Predators, Clarence A. Ryan, Thomas Moloshok, Gregory Pearce, Gynhueng An, Robert W. Thornburg, Gerald Hall, Russell Johnson, Edward E. Farmer, Curtis Palm Jan 1990

Engineering Proteinase Inihibitor Genes For Plant Defense Against Predators, Clarence A. Ryan, Thomas Moloshok, Gregory Pearce, Gynhueng An, Robert W. Thornburg, Gerald Hall, Russell Johnson, Edward E. Farmer, Curtis Palm

Journal of the Iowa Academy of Science: JIAS

Small proteinaceous inhibitors (Mr<20,000) of the digestive serine proteinases of animals and microorganisms are found as moderately abundant proteins in storage organs and leaves of many plant genera. The proteins are powerful inhibitors of the digestive enzymes of plant predators and therefore are considered to be part of the array of defensive chemicals of plants. Proteinase inhibitor genes show excellent promise, using DNA technology, to manipulate plant genomes to express these biologically active proteins in order to improve natural defense systems. Members of two unrelated families of serine proteinase inhibitors found in tomato and potato plants, called Inhibitor I (monomer Mr 8000) and Inhibitor II (monomer Mr 12,300), are under both environmental and developmental regulation in different tissues of the plants. Genes coding for wound-inducible Inhibitors I and II have been isolated from both tomato and potato genomes and characterized. Tobacco plants have been transformed with the chimeric genes containing wound-inducible promoters fused with the reporter gene, chloramphenicol acetyl transferase, to assess promoter function and signal transmission. Transacting factors that regulate their expression in response to wounding are also being identified and purified. Intact genes are being employed to transform agriculturally important crop plants to determine their potential usefulness to enhance defensive capabilities of plants against herbivores and pathogens.