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1998

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Articles 1831 - 1860 of 2574

Full-Text Articles in Physical Sciences and Mathematics

Introduction To The 1997 Symposium On Iowa's Declining Flora And Fauna, Cornelia F. Mutel Jan 1998

Introduction To The 1997 Symposium On Iowa's Declining Flora And Fauna, Cornelia F. Mutel

Journal of the Iowa Academy of Science: JIAS

In 1980, Iowa's biologists and ecologists gathered at the 92nd annual meeting of the Iowa Academy of Science to present a symposium on the state's declining flora and fauna. Papers were published a year later in a single issue of The Proceedings of The Iowa Academy of Science (Vol. 88, No. 1), which has since been widely cited and much used as a baseline for research efforts. The symposium was a noble undertaking, for although the highly altered composition of Iowa's presettlement ecology had been widely recognized throughout the previous century, no single publication or gathering to that date …

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The Status Of Iowa's Lepidoptera, Dennis W. Schlicht, Timothy T. Orwig Jan 1998

The Status Of Iowa's Lepidoptera, Dennis W. Schlicht, Timothy T. Orwig

Journal of the Iowa Academy of Science: JIAS

Including strays, 122 species of butterflies have been confirmed in Iowa. However, since European settlement the populations of taxa of Iowa Lepidoptera have declined. While certain generalist species have experienced declines, species with life cycles that include native habitats, especially prairies and wetlands, have been particularly vulnerable. In a 1994 revision of the Iowa endangered and threatened species list, the Natural Resource Commission (NRC) listed two species of butterflies as endangered, five as threatened, and 25 as special concern, using general legal definitions of those rankings (NRC 1994). But after examining recent records, we have revised that list, using numbers …

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Cover - Perspectives On The Declining Flora And Fauna Of Iowa: A Symposium, Part 2 Jan 1998

Cover - Perspectives On The Declining Flora And Fauna Of Iowa: A Symposium, Part 2

Journal of the Iowa Academy of Science: JIAS

No abstract provided.

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Perspectives On Iowa's Declining Amphibians And Reptiles, James L. Christiansen Jan 1998

Perspectives On Iowa's Declining Amphibians And Reptiles, James L. Christiansen

Journal of the Iowa Academy of Science: JIAS

Changes in range and abundance of Iowa's amphibians and reptiles can be deduced by comparing records from recent studies with excellent collections from Iowa by Professor R. M. Bailey made from 1938-1943 in addition to museum records accumulated before 1950. Additional recent data make necessary this updating of a similar study conducted in 1980. The current study finds many of our frogs to be in decline, some in a pattern from north to south, but most as a diffused loss of populations, probably as a result of habitat destruction. The crawfish frog, one of the two frogs considered threatened in …

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Mammals Of Iowa: Holocene To The End Of The 20th Century, John B. Bowles, Daryl L. Howell, Richard P. Lampe, Howard P. Whidden Jan 1998

Mammals Of Iowa: Holocene To The End Of The 20th Century, John B. Bowles, Daryl L. Howell, Richard P. Lampe, Howard P. Whidden

Journal of the Iowa Academy of Science: JIAS

This review of Iowa's mammal fauna at the close of the 20th century summarizes changes in distributional patterns following Euroamerican settlement in the early 1800s. Data from historical records, museum specimens, and presettlement late Holocene fossils indicate presence of 69 resident mammals at that time. Hunting pressures and the conversion of prairie and forest to agricultural fields reduced the populations and ranges of many state mammals, and 14 species were extirpated by 1900. An additional 15 species are either uncommon or rare today, and the Iowa Department of Natural Resources lists four species as endangered, three as threatened and one …

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Back Cover Jan 1998

Back Cover

Journal of the Iowa Academy of Science: JIAS

No abstract provided.

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Carrion Beetles (Coleoptera: Silphidae) Of Northeastern Iowa: A Comparison Of Baits For Sampling, David R. Coyle, Kirk J. Larsen Jan 1998

Carrion Beetles (Coleoptera: Silphidae) Of Northeastern Iowa: A Comparison Of Baits For Sampling, David R. Coyle, Kirk J. Larsen

Journal of the Iowa Academy of Science: JIAS

Carrion beetles (Coleoptera: Silphidae) were inventoried over a 8-week period from June into August of 1996 at 10 sites in 4 counties of extreme northeastern Iowa. Carrion preference and relative abundance of carrion beetles were studied by use of non-lethal pitfall traps constructed from large plastic plant pots and baited with aged fish, beef liver, chicken, or piglets. A total of 3,183 carrion beetles were collected, representing 11 different species. The most commonly encountered species of carrion beetles in northeastern Iowa included Necrophila americana (71.5%) and Oiceoptoma novaboracense (18.5%). When comparing baits, chicken and fish attracted the greatest number of …

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Decline Of Iowa Populations Of The Regal Fritillary (Speyeria Idalia) Drury, Diane M. Debinskl, Liesl Kelly Jan 1998

Decline Of Iowa Populations Of The Regal Fritillary (Speyeria Idalia) Drury, Diane M. Debinskl, Liesl Kelly

Journal of the Iowa Academy of Science: JIAS

The Regal Fritillary butterfly, Speyeria idalia Drury (Lepidoptera: Nymphalidae, Argynninae), is a prairie endemic species which has exhibited a dramatic decline in Iowa during the last few decades. Tallgrass prairie is the primary habitat of S. idalia and the butterfly's presence is correlated with the presence of violets (Violaceae). Due to the extensive habitat fragmentation of Iowa prairies, both the butterfly and its host plant populations are limited primarily to unplowed, relatively pristine prairies. Thus, S. idalia is an excellent case study of a prairie endemic species. Here, we report on the results of a two-year survey of the insect …

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Front Matter Jan 1998

Front Matter

Journal of the Iowa Academy of Science: JIAS

No abstract provided.

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The Fungi, Lichens, And Myxomycetes Of Iowa: A Literature Review And Evaluation, Lois H. Tiffany, George Knaphus Jan 1998

The Fungi, Lichens, And Myxomycetes Of Iowa: A Literature Review And Evaluation, Lois H. Tiffany, George Knaphus

Journal of the Iowa Academy of Science: JIAS

The fungi have been, and continue to be, a poorly documented portion of Iowa’s biological inheritance. Although many are perennially present in soil and plant debris and are crucially involved in the release and recycling of materials from organic residues or are partners with plant roots as mycorrhizae, they are not obvious until they produce fruiting structures such as mushrooms, boletes, brackets, puffballs, etc. The fungi causing plant disease are more obvious because of the reactions of their host plants; thus the earliest records of Iowa fungi are of ones causing plant diseases commonly referred to as mildews, rusts, and …

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Iowa's Avifauna: Recent Changes And Prospects For The Future, James J. Dinsmore Jan 1998

Iowa's Avifauna: Recent Changes And Prospects For The Future, James J. Dinsmore

Journal of the Iowa Academy of Science: JIAS

Iowa's avifauna has changed dramatically since 1980. The state list now has 40 additional species and totals 398 species, the most of any vertebrate group. Four species that had not previously nested in Iowa (Ring-billed Gull, Great-tailed Grackle, House Finch, Eurasian Tree Sparrow) and four whose nesting populations had disappeared (Double-crested Cormorant, Sandhill Crane, Piping Plover, Least Tern) now breed regularly here. Little Blue Heron, Cattle Egret, White-faced Ibis, Mississippi Kite, Prairie Warbler, and Red Crossbill nested for the first time but do not have established nesting populations. Trumpeter Swan, Peregrine Falcon, Greater Prairie Chicken, and Sharp-tailed Grouse have been …

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Front Matter Jan 1998

Front Matter

Journal of the Iowa Academy of Science: JIAS

No abstract provided.

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Safety Issues And Iowa Science Teachers, Jack A. Gerlovich, Ed Wilson, Rahul Parsa Jan 1998

Safety Issues And Iowa Science Teachers, Jack A. Gerlovich, Ed Wilson, Rahul Parsa

Journal of the Iowa Academy of Science: JIAS

The National Science Education Standards are providing an excellent blue print for improving science teaching for all students. However, the Standards are placing serious demands on teachers attempts to make science activities inquiry-based, real-life, open-ended, and directly applicable to today's students. This situation is further aggravated when teachers do not know essential science safety information from both federal and state governing agencies, as well as professional organizations. With proper training and tools, however, this problem can be positively addressed.

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Index For Volume 105 - Notice Of Rate Increase Jan 1998

Index For Volume 105 - Notice Of Rate Increase

Journal of the Iowa Academy of Science: JIAS

No abstract provided.

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Book Review Of Paleolimnology Of Europeanmaar Lakes By J. F.W. Negendank & B. Zolitschka (Eds)., J. Platt Bradbury Jan 1998

Book Review Of Paleolimnology Of Europeanmaar Lakes By J. F.W. Negendank & B. Zolitschka (Eds)., J. Platt Bradbury

United States Geological Survey: Staff Publications

This book represents a collection of papers presented at a symposium in May, 1991 on the formation and paleolimnology of European maar lakes. Paleolimnological discussions embrace maar lake deposits of late Quaternary to early Tertiary age in Germany, France and Italy. The goal of the symposium and its outgrowth, this book, is to develop a funding initiative to study, core and analyze the deposits of these remarkable depositional systems.

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Early Life History Stages Of Gulf Sturgeon In The Suwannee River, Florida, Kenneth J. Sulak, James P. Clugston Jan 1998

Early Life History Stages Of Gulf Sturgeon In The Suwannee River, Florida, Kenneth J. Sulak, James P. Clugston

United States Geological Survey: Staff Publications

Egg sampling confirmed that Suwannee River Gulf sturgeon Acipenser ozyrinchus desotoi, a subspecies of Atlantic sturgeon A. o. oxyrinchus use the same spawning site at river kilometer (rkm) 215 from the mouth of the river each year. Forty-nine eggs were recorded in 1995, and 368 were recorded in 1996. Spawning began 4-7 d after the March new moon in both years and lasted 10-11 d; in 1996, a second 10-d spawning round began on the April new moon. Developmental synchrony among eggs recovered suggested serval discrete spawning events in both years. Total eggs deposited for three 1996 sampling days …

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Submarine Sand Resources, Southeastern Virginia - Contributions From Year Nine And Year Ten Of Virginia’S Continental Margins Program, Carl Hobbs Iii, C. Scott Hardaway Jr., C. R. Berquist Jan 1998

Submarine Sand Resources, Southeastern Virginia - Contributions From Year Nine And Year Ten Of Virginia’S Continental Margins Program, Carl Hobbs Iii, C. Scott Hardaway Jr., C. R. Berquist

VIMS Books and Book Chapters

Virginia’s Year-Nine and Year-Ten funds from the Continental Shelf Program were used to supplement other work funded by the Minerals Management Service in an ongoing Cooperative Agreement focused on the area offshore of southeastern Virginia. Year-Nine and Year-Ten funds facilitated interpretation of subbottom profiles and the analysis of sediment samples from cores and grabs. On Virginia’s sediment-starved continental shelf, deposits of material potentially suitable for use as beach nourishment or, perhaps, as construction aggregate occur in three stratigraphic settings, each with specific characteristics of morphology, grain-size gradients, likelihood of discovery, and physical ease of exploitation. All must be verified with …

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Algorithms For Message Delivery In A Micromobility Environment, Amy L. Murphy, Gruia-Catalin Roman, George Varghese Jan 1998

Algorithms For Message Delivery In A Micromobility Environment, Amy L. Murphy, Gruia-Catalin Roman, George Varghese

All Computer Science and Engineering Research

As computing components get smaller and people become accustomed to having computational power at their disposal at any time, mobile computing is developing as an important research area. One of the fundamental problems in mobility is maintaining connectivity through message passing as the user moves through the network. This is usually accomplished in one of two ways: search or tracking. In search, an algorithm hunts the mobile unit through the network each time a message is to be delivered, while in tracking, a specific home keeps up to date information about the current location of the mobile unit. Our paper …

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Application Development And Management In The Programmers' Playground, T. Paul Mccartney, E.F. Berkley Shands, Kenneth J. Goldman, William M. Shapiro Jan 1998

Application Development And Management In The Programmers' Playground, T. Paul Mccartney, E.F. Berkley Shands, Kenneth J. Goldman, William M. Shapiro

All Computer Science and Engineering Research

Application management refers to the process of making software applications available to end-users and providing automated mechanisms for launching and joining such applications. The Programmers' Playground is a computing environment for creating distributed applications from modular, reusable components. This paper discusses a set of tools that enable application developers to: (1) design and debug Playground distributed applications from existing "off-the-shelf" components using a visual configuration tool, (2) make new application components available on the Internet through a "launcher" service, and (3) make complete distributed applications available via a World Wide Web interface, enabling end-users to launch and join the applications …

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On-Line Scheduling With Hard Deadlines, Sally A. Goldman, Jyoti Parwatikar, Subhash Suri Jan 1998

On-Line Scheduling With Hard Deadlines, Sally A. Goldman, Jyoti Parwatikar, Subhash Suri

All Computer Science and Engineering Research

We study non-preemptive, online admission control in the hard deadline model: each job must be either serviced prior to its deadline, or be rejected. Our setting consists of a single resource that services an online sequence of jobs; each job has a length indicating the length of time for which it needs the resource, and a delay indicating the maximum time it can wait for the service to be started. The goal is to maximize total resource utilization. The jobs are non-preemptive and exclusive, meaning once a job begins, it runs to completion, and at most one job can use …

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Agnostic Learning Of Geometric Patterns, Sally A. Goldman, Stephen S. Kwek, Stephen D. Scott Jan 1998

Agnostic Learning Of Geometric Patterns, Sally A. Goldman, Stephen S. Kwek, Stephen D. Scott

All Computer Science and Engineering Research

Goldberg, Goldman, and Scott demonstrated how the problem of recognizing a landmark from a one-dimensional visual image can be mapped to that of learning a one-dimensional geometric pattern and gave a PAC algorithm to learn that class. In this paper, we present an efficient on-line agnostic learning algorithm for learning the class of constant-dimension geometric patterns. Our algorithm can tolerate both classification and attribute noise. By working in higher dimensional spaces we can represent more features from the visual image in the geometric pattern. Our mapping of the data to a geometric pattern, and hence our learning algorithm, is applicable …

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Comparison Of Recent Coral Life And Death Assemblages To Pleistocene Reef Communities: Implications For Rapid Faunal Replacement On Recent Reefs, Benjamin J. Greenstein, Lora A. Harris, H. Allen Curran Jan 1998

Comparison Of Recent Coral Life And Death Assemblages To Pleistocene Reef Communities: Implications For Rapid Faunal Replacement On Recent Reefs, Benjamin J. Greenstein, Lora A. Harris, H. Allen Curran

Geosciences: Faculty Publications

Marine ecologists and paleoecologists are increasingly recognizing that the Pleistocene and Holocene fossil record of coral reefs is the exclusive database from which an assessment of the long-term responses of reef communities to environmental perturbations may be obtained. The apparent persistence of coral communities in the face of intense fluctuations in sea level and sea surface temperature during glacial and interglacial stages of Pleistocene time is in marked contrast to dramatic fluctuations in reef community structure documented by short-term monitoring studies. We compared the taxonomic structure of live and dead coral communities on a modem patch reef currently undergoing a …

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Ophiomorpha Nodosa In Estuarine Sands Of The Lower Miocene Calvert Formation At The Pollack Farm Site, Delaware, Molly F. Miller, H. Allen Curran, Ronald L. Martino Jan 1998

Ophiomorpha Nodosa In Estuarine Sands Of The Lower Miocene Calvert Formation At The Pollack Farm Site, Delaware, Molly F. Miller, H. Allen Curran, Ronald L. Martino

Geosciences: Faculty Publications

No abstract provided.

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Measurement Of Thin Liquid Film Drainage Using A Novel High-Speed Impedance Analyzer, K. O. Hool, R. C. Saunders, Harry J. Ploehn Jan 1998

Measurement Of Thin Liquid Film Drainage Using A Novel High-Speed Impedance Analyzer, K. O. Hool, R. C. Saunders, Harry J. Ploehn

Faculty Publications

This work describes the design and implementation of a new instrument, called the thin film impedance analyzer, which measures the rate of drainage of thin oil films. The instrument forms an oil film by elevating a planar oil–water interface into a water drop hanging from a stainless steel capillary tube immersed in the oil. The instrument measures the magnitude of the impedance of the matter between the capillary tube and a screen electrode immersed in the lower water phase. Under appropriate conditions, the capacitance of the oil film dominates the impedance. The instrument records the increase in the magnitude of …

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Π-Systems As Lithium/Hydrogen Bond Acceptors: Some Theoretical Observations, Salai Cheettu Ammal, P. Venuvanalingam Jan 1998

Π-Systems As Lithium/Hydrogen Bond Acceptors: Some Theoretical Observations, Salai Cheettu Ammal, P. Venuvanalingam

Faculty Publications

Ab initio calculations at the Hartree–Fock and correlated levels and density functional theory calculations have been performed with 6-31++G(d,p) and 6-311++G(d,p)basis sets on LiF and HF complexes of benzene, ethylene, and acetylene. Complex binding energies have been corrected for basis set superposition error, and zero point energy corrections have been done on Hartree–Fock binding energies. Computed results indicate that the complexes exist in different conformations and among them those with π-lithium and π-hydrogen bonds are the most stable. π-lithium bonds are stronger than π-hydrogen bonds. The computed binding energies and geometry of HF complexes correlate well with the available experimental …

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Ab Initio And Dft Investigations Of Lithium/Hydrogen Bonded Complexes Of Trimethylamine, Dimethyl Ether And Dimethyl Sulfide, Salai Cheettu Ammal, P. Venuvanalingam Jan 1998

Ab Initio And Dft Investigations Of Lithium/Hydrogen Bonded Complexes Of Trimethylamine, Dimethyl Ether And Dimethyl Sulfide, Salai Cheettu Ammal, P. Venuvanalingam

Faculty Publications

Ab initio and DFT computations have been carried out on LiF and HF complexes of a set of n-donors viz. trimethylamine, dimethyl ether and dimethyl sulfide with a 6-31++G(d,p) basis set. The effect of correlation has been included with MP2, MP4 and DFT calculations. NBO analyses of the wavefunctions have been performed to examine the intermolecular interaction at the orbital level. Calculations reveal that these donors form strong n→σ* complexes and computed binding energies of the (CH3)2O···HF complex agree very well with the experimental binding energies from IR spectroscopy. LiF forms stronger complexes than HF, …

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Ab Initio Study Of Formazan And 3-Nitroformazan, G. Buemi, F. Zuccarello, P. Venuvanalingam, M. Ramalingam, Salai Cheettu Ammal Jan 1998

Ab Initio Study Of Formazan And 3-Nitroformazan, G. Buemi, F. Zuccarello, P. Venuvanalingam, M. Ramalingam, Salai Cheettu Ammal

Faculty Publications

Formazan and 3-nitroformazan have been investigated at abinitio level (MP2/6-31G** and B3LYP/6-31G**) in all their possible conformations, for studying the various possibilities of intramolecular hydrogen bonding formation. The trans-syn-s-cis (TSSC), known also asyellowform, has been found to be the most stable conformer (at least in the gas phase) in both compounds. This particular structure is strongly stabilized by a N–H···N hydrogen bridge, which gives rise to a hexatomic chelate ring, with the possibility of a proton transfer process.This closely resembles that of malondialdehyde, previously studied, in the evolution of the …

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Analysis Of Experimental Designs Used In Bioassays, Vidyadhar Kshirsagar Jan 1998

Analysis Of Experimental Designs Used In Bioassays, Vidyadhar Kshirsagar

Master's Theses and Doctoral Dissertations

No abstract provided.

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Well Characteristics Influencing Microscopic Particulate Analysis Risk Index, Robert Christopher Sharek Jan 1998

Well Characteristics Influencing Microscopic Particulate Analysis Risk Index, Robert Christopher Sharek

Retrospective Theses and Dissertations

Cryptosporidium parvum is a common surface water contaminant that can cause illness in human beings. The presence of this etiological agent in groundwater identifies the groundwater as under the direct influence (GWUDI) of surface water. Currently the determination of GWUDI water sources requires an expensive, labor-intensive laboratory procedure called the Microscopic Particulate Analysis (MPA). The results of the MPA provide a risk index that rates the degree of surface water contamination. The objective of this study is to identify other methods of identifying GWUDI of surface waters, such as well characteristics and hydrogeologic factors which may contribute to higher MPA …

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Characterization And Improvement Of Eos Land Products Using Measurements At Ameriflux Grassland And Wheat Sites In The Arm/Cart Region: Research Annual Performance Report For Period March 1, 1998- January 8, 1999, E. A. Walter-Shea, S. B. Verma Jan 1998

Characterization And Improvement Of Eos Land Products Using Measurements At Ameriflux Grassland And Wheat Sites In The Arm/Cart Region: Research Annual Performance Report For Period March 1, 1998- January 8, 1999, E. A. Walter-Shea, S. B. Verma

School of Natural Resources: Documents and Reviews

No abstract provided.

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