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Genetic Variation Among And Within S1 Progenies Of Maize, R. J. Getschman, A. R. Hallauer

Journal of the Iowa Academy of Science: JIAS

Inbred line development consumes a great portion of the breeder's time and resources in maize (Zea mays L.) breeding programs. Source populations for line development often are developed by selfing F2 populations developed from elite line crosses. Visual selection is practiced among and within selfed progenies during the selection process for one or two generations before evaluated in testcrosses for combining ability. Effective discrimination among and within inbred and testcross progenies depends on the amount of genetic variation present. The objective of this study was to determine the effectiveness of selection among and within S₁ progenies developed from crosses …

Area-Dependent Changes In Bird Densities In Iowa Marshes, Mike Brown, James J. Dinsmore

Journal of the Iowa Academy of Science: JIAS

Species richness and density of Iowa marsh birds were positively correlated with marsh area, but area accounted for 69% of the variation in species richness and only 19% of the variation in density. Although densities of five of nine species examined correlated with marsh area, total density was not significantly correlated with area when the effects of species richness were eliminated. Area was the most frequent significant variable in regression equations for species richness, total density, and the densities of nine individual species on six variables. Unlike species-area relationships, density-area relationships are relatively weak, and knowledge of other ecological factors …

Front Matter

Journal of the Iowa Academy of Science: JIAS

No abstract provided.

Heating Degree Days In Iowa Relative To Home Natural Gas Consumption, Conservation Efforts, And Long-Term Trends, Richard E. Carlson

Journal of the Iowa Academy of Science: JIAS

A methodology is presented to assess the effectiveness of conservation efforts relative to home heating. Billing period heating degree days and natural gas consumption relationships are established for a typical household for nineteen heating seasons using simple linear regression. Associated correlations (r² values) were greater than 0. 95 for nineteen different seasons. Regression coefficients (b₀ and b₁) were found to decrease with time indicating reduced natural gas consumption due to conservation efforts. Procedures are presented to illustrate dollar savings relative to conservation efforts using the regression relationships. Long-term trends for heating degree days at the Ames, …

Food Habits Of The Northern Saw-Whet Owl In Central Iowa: Effects Of Roost Location, Stephen J. Dinsmore, William R. Clark

Journal of the Iowa Academy of Science: JIAS

During the period 1979-89, 900 northern saw-whet owl (Aegolius acadicus) pellets with identifable remains of prey were collected at 18 central Iowa locations. Peromyscus were the most frequent prey consumed, comprising 81.2% of all prey items. Other prey species were voles (Microtus), western harvest mice (Reithrodontomys megalotis), shrews (Blarina brevicauda, Sorex cinereus, and Cryptotis parva), and a single unidentified bird. Peromyscus comprised the largest proportion of pellets from different successional stages. There were significant differences for four prey groups (Peromyscus, Microtus, Reithrodontomys, and shrews) among years. Peromyscus and R. megalotis showed significant differences among locations. Microtus and shrews were variable …

Studies Of The Precambrian Geology Of Iowa: Part 3. Geochronologic Data For The Matlock Drill Holes, W. R. Van Schmus, E. T. Wallin

Journal of the Iowa Academy of Science: JIAS

U-Pb ages have been determined for quartz monzodiorite (2,535 ± 5Ma) recovered from drill hole ClO and for keratophyre (1,782±10 Ma) recovered from drill hole C5 of the Matlock exploration project. Sm-Nd whole-rock analyses for several rock types from the Otter Creek layered mafic complex recovered from several drill holes of the Matlock project yield an isochron age of 2,890 ± 90 Ma, with an ϵNd(t) of -0.9 ± 2.4. These ages document crustal evolution in northwest Iowa, including the southern margin of the Superior Province, over more than one billion years from 2.9 to 1.8 Ga. Isotopic data also …

Comprehensive Examination In Physics, Timothy Cooney

Iowa Science Teachers Journal

The following exam has been developed over several years of physics teaching and research. It is designed to serve as the comprehensive final exam for graduating seniors completing physics at Northern University High School in Cedar Falls, Iowa.

Astronomy Bulletin - The 1991 Summer Sky, P. Steven Leiker

Iowa Science Teachers Journal

No abstract provided.

Science Notes - Program For Leadership In Earth Systems Education Workshops

Iowa Science Teachers Journal

The Program for Leadership in Earth Systems Education (PLESE) has announced its 1992 Summer Workshop program. The program will serve groups of teachers at two sites, Ohio State University in Columbus and the University of Northern Colorado in Greeley.

Science Notes - Scholarships Available To Minority Students, Stephanie A. Althof

Iowa Science Teachers Journal

The American Physical Society (APS) is once again offering "Corporate Sponsored Scholarships for Minority Undergraduate Students Who Major in Physics."

An Inexpensive And Collapsible Plant Growth Frame, Al Janulaw, Mat Keller

Iowa Science Teachers Journal

This plant growth frame was designed for use in second and fourth grade classrooms as a part of National Science Foundation Grant TEI 8751303, Materials and Assistance for Science Teaching (MAST). We needed frames that were relatively inexpensive, could be made from locally available materials and would be easy to store when not in use. The frame is made from PVC pipe. The light source is a 48-inch, two-bulb shop light, using ordinary fluorescent tubes. A plug-in timer is used to control the time of illumination. Our first models included a plywood base, but some teachers have omitted this. The …

The Iowa Science Teachers Fall Conference, 1991, Iowa Academy Of Science

Iowa Academy of Science Documents

Contents:

Speakers ... 4
Pre-conference Workshops ... 6
General Session ... 9
Concurrent Sessions 1 ... 9
Concurrent Sessions 2 ... 13
Application for Membership ... Centerfold
Registration Fonns ... Centerfold
Luncheon Information ... 17
Concurrent Sessions 3 ... 17
Concurrent Sessions 4 ... 21
Maps ... 25 & 26

Cover - Table Of Contents

Journal of the Iowa Academy of Science: JIAS

No abstract provided.

Back Cover

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.

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 …

Part Ii - Regular Issue

Journal of the Iowa Academy of Science: JIAS

No abstract provided.

Results Of The August Roadside Survey For Upland Wildlife In Iowa: 1963-1988, Willie J. Suchy, Ronald J. Munkel, James M. Kienzler

Journal of the Iowa Academy of Science: JIAS

Results of the August roadside survey collected from 1963 through 1988 were examined to determine if trends could be detected in the counts of ring-necked pheasants (Phasianus colchicus), northern bobwhite (Colinus virginianus), gray partridge (Perdix perdix), cottontail rabbits (Sylvilagus floridanus), and white-tailed jackrabbits (Lepus townsendii). The counts also were compared to harvest estimates co determine if correlations exist. Statistically significant linear trends were detected statewide for pheasants, gray partridge and jackrabbits during the 1963 co 1988 period. Trends were downward for all species except gray partridge. During the late 12 years (1977 through 1988), the only significant trend detected was …

The Role Of Mechanical Injury In An Experimental Transmission Of Flexibacter Columnaris To Fingerling Walleye, Manzoor Hussain, Robert C. Summerfelt

Journal of the Iowa Academy of Science: JIAS

The role of mechanical injury in transmission of Flexibacter columnaris to walleye fingerlings (Stizostedion vitreum vitreum) was investigated. Two groups (1 and 2) of 10 fish each, 7 to 9 cm total length, were exposed to a suspension of F lexibacter columnaris containing 3 X 105 cfu/ mL; fish in group 1 were injured with a scratch along their flank; fish in group 2 were not injured. Two control groups (3 and 4) of 5 fish each were exposed to a sterile broth; group 3 was injured with a scratch and group 4 was not. In 72 h, morbidity was …

Front Matter

Journal of the Iowa Academy of Science: JIAS

No abstract provided.

Middle Woodland Field Camps In The Cedar Valley, Michael J. Perry

Journal of the Iowa Academy of Science: JIAS

Archaeological survey and testing of two proposed road projects within the Cedar River valley resulted in the location of several prehistoric occupational sites. Ceramics recovered at three of the sites, 13LN226, 13LN236, and 13LN243, are identified as late Middle Woodland period specimens, dating to ca. A.D. 200. The three sites border Cedar River tributaries, occupying high terrace formations within the broad bottomlands of the Cedar valley. The type and distribution of artifacts suggest that 13LN236 and 13LN243 functioned as repeatedly utilized, short-term extractive and processing camps. Previous research at sites of similar age focused on small, protected rockshelters and large, …

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.

Cover - Table Of Contents

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 …

Studies Of The Precambrian Geology Of Iowa: Part 1. The Otter Creek Layered Igneous Complex, Kenneth E. Windom, Karl E. Seifert, Raymond R. Anderson

Journal of the Iowa Academy of Science: JIAS

Rocks from a buried igneous body, herein called the Otter Creek layered igneous complex, were recovered by drilling in Archean rocks in northwestern Iowa. This complex consists of layers of ultramafic and mafic cumulate rocks, including bronzitite, harzburgite, dunite, gabbro, and anorthosite. These rocks have been subjected to low-grade metamorphism with a patagenesis including serpentine, chlorite, talc, uralitic amphiboles, magnetite, albite, epidote, sericite, and minor quartz and calcite. During its intrusion, the magma which gave rise to the layered body engulfed a large block of rock consisting of banded iron formation and thin lamprophyre dikes. Both the iron formation and …