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Life Sciences

1991

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Articles 151 - 180 of 182

Full-Text Articles in Education

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 Jan 1991

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 …


Food Habits Of The Northern Saw-Whet Owl In Central Iowa: Effects Of Roost Location, Stephen J. Dinsmore, William R. Clark Jan 1991

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 …


Editorial Board & Iowa Academy Of Science Officers And Directors Jan 1991

Editorial Board & Iowa Academy Of Science Officers And Directors

Journal of the Iowa Academy of Science: JIAS

No abstract provided.


Cover - Table Of Contents Jan 1991

Cover - Table Of Contents

Journal of the Iowa Academy of Science: JIAS

No abstract provided.


Annual Report Of The Iowa Academy Of Science, 1989-90, Paul E. Rider Jan 1991

Annual Report Of The Iowa Academy Of Science, 1989-90, 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, 1989 to June 30, 1990. 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.


Editorial Board & Iowa Academy Of Science Officers And Directors Jan 1991

Editorial Board & Iowa Academy Of Science Officers And Directors

Journal of the Iowa Academy of Science: JIAS

No abstract provided.


Cover - Table Of Contents Jan 1991

Cover - Table Of Contents

Journal of the Iowa Academy of Science: JIAS

No abstract provided.


Regulation Of Phytochrome Gene Expression, J. T. Colbert, S. A. Costigan, P. Avissar, Z. Zhao Jan 1991

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. …


Hormonal Regulation Of Gene Expression M The Aleurone Layers Of Cereal Grains, Tuan-Hua David Ho Jan 1991

Hormonal Regulation Of Gene Expression M The Aleurone Layers Of Cereal Grains, Tuan-Hua David Ho

Journal of the Iowa Academy of Science: JIAS

The aleurone layers of cereal grains offer a convenient system for studies of the molecular action of two plant hormones, gibberellins (GA) and abscisic acid (ABA). Gibberellins induce the synthesis of ix-amylase and several other hydrolytice enzymes. The action of GA is essentially at the transcriptional level, it enhances the level of steady-state levels of ix-amylase mRNAs, the rate of transcription of ᴕ-amylase genes and the activity of a trans-acting factor which interacts with specific regions of ix-amylase genes. Abscisic acid antagonizes the effect of GA by inhibiting the induction of hydrolytic enzymes, yet the effect of ABA itself is …


Editorial Board & Iowa Academy Of Science Officers And Directors Jan 1991

Editorial Board & Iowa Academy Of Science Officers And Directors

Journal of the Iowa Academy of Science: JIAS

No abstract provided.


Middle Woodland Field Camps In The Cedar Valley, Michael J. Perry Jan 1991

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, …


Area-Dependent Changes In Bird Densities In Iowa Marshes, Mike Brown, James J. Dinsmore Jan 1991

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 …


Comparison Of Mass Selection And S1 Testing Recurrent-Selection Methods In Sorghum, R. E. Secrist, R. E. Atkins Jan 1991

Comparison Of Mass Selection And S1 Testing Recurrent-Selection Methods In Sorghum, R. E. Secrist, R. E. Atkins

Journal of the Iowa Academy of Science: JIAS

Mass selection and S1 testing are often used for the improvement of sorghum [Sorghum bicolor (L.) Moench] populations. Both recurrent selection methods have a place in applied breeding programs and should be used where they are likely to be most advantageous. S1 families of a random-mating sorghum population mass selected three cycles (C3) for individual-panicle weight [IAP1R(M)C3] were compared with S1 families from a population (C3) advanced from the same base (CO) population by using replicated yield tests in each cycle [ IAP4R(S1)C3]. Our objectives were to compare the performance in C3 of families developed …


Back Cover Jan 1991

Back Cover

Journal of the Iowa Academy of Science: JIAS

No abstract provided.


Cover - Table Of Contents Jan 1991

Cover - Table Of Contents

Journal of the Iowa Academy of Science: JIAS

No abstract provided.


Front Matter Jan 1991

Front Matter

Journal of the Iowa Academy of Science: JIAS

No abstract provided.


Studies Of The Precambrian Geology Of Iowa: Part 3. Geochronologic Data For The Matlock Drill Holes, W. R. Van Schmus, E. T. Wallin Jan 1991

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 …


An Annotated Checklist Of The Vascular Plant Flora Of Guthrie County, Iowa, Dean M. Roosa, Lawrence J. Eilers, Scott Zager Jan 1991

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.


Journal Of The Iowa Academy Of Science Submission Form And Instruction Sheet Jan 1991

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 1991

Back Cover

Journal of the Iowa Academy of Science: JIAS

No abstract provided.


Part Ii - Regular Issue Jan 1991

Part Ii - Regular Issue

Journal of the Iowa Academy of Science: JIAS

No abstract provided.


The Role Of Mechanical Injury In An Experimental Transmission Of Flexibacter Columnaris To Fingerling Walleye, Manzoor Hussain, Robert C. Summerfelt Jan 1991

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 …


Estimates Of Quantitative Genetic Parameters M Iap2b(M) Random-Mating Sorghum Population, A. J. Maves, R. E. Atkins Jan 1991

Estimates Of Quantitative Genetic Parameters M Iap2b(M) Random-Mating Sorghum Population, A. J. Maves, R. E. Atkins

Journal of the Iowa Academy of Science: JIAS

Random-mating populations of sorghum [Sorghum bicolor (L.) Moench] are used extensively as germ plasm in the development of parental lines for hybrids. Populations improved by recurrent selection provide a useful source for the selection of superior parental lines. Our objective was to determine the effectiveness of mass selection for threshed-panicle weight by comparing the performance of lines (S1 families) chosen randomly from CO and C4 of sorghum population IAP2B. Sixty S1 families from each cycle were grown in five Iowa environments.

Four cycles of selection for panicle weight shifted the mean for grain yield favorably, and the range …


Editorial Board & Iowa Academy Of Science Officers And Directors Jan 1991

Editorial Board & Iowa Academy Of Science Officers And Directors

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 Jan 1991

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 …


Heating Degree Days In Iowa Relative To Home Natural Gas Consumption, Conservation Efforts, And Long-Term Trends, Richard E. Carlson Jan 1991

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, …


Studies Of The Precambrian Geology Of Iowa: Part 1. The Otter Creek Layered Igneous Complex, Kenneth E. Windom, Karl E. Seifert, Raymond R. Anderson Jan 1991

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 …


Studies Of The Precambrian Geology Of Iowa: Part 2. The Matlock Keratophyre, Kenneth E. Windom, Karl E. Seifert, Raymond R. Anderson Jan 1991

Studies Of The Precambrian Geology Of Iowa: Part 2. The Matlock Keratophyre, Kenneth E. Windom, Karl E. Seifert, Raymond R. Anderson

Journal of the Iowa Academy of Science: JIAS

Felsic pyroclastic rock occurs in the Precambrian basement in northwestern Iowa. This rock was recovered by drilling and originally logged as rhyolite; however it is severely depleted in K2O, Rb, Ba, Cs, and other mobile elements and is more properly called keratophyre. The volcanic unit lies atop a layered mafic/ultramafic complex and contains xenoliths of gabbro apparently derived from the layered body. These xenoliths are severely altered and are composed of secondary hydrated and carbonated minerals. The gabbros are enriched in incompatible trace elements, whose abundance patterns complement those of the keratophyre. Trace element abundance patterns for the …


Annual Report Of The Iowa Academy Of Science, 1990-91, Paul E. Rider Jan 1991

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.


Ua3/8/1 L.Y. Lancaster Professorship Report, Wku Ogden College Of Science & Technology Jan 1991

Ua3/8/1 L.Y. Lancaster Professorship Report, Wku Ogden College Of Science & Technology

WKU Archives Records

Report by Dr. Blaine Ferrell, L.Y. Lancaster Professor about activities for 1990-91 funded by the Ogden Foundation.