Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

2001

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 121 - 150 of 3067

Full-Text Articles in Physical Sciences and Mathematics

Introduced Fungi: Some Cause Significant Plant Disease Problems, Lois H. Tiffany Dec 2001

Introduced Fungi: Some Cause Significant Plant Disease Problems, Lois H. Tiffany

Journal of the Iowa Academy of Science: JIAS

Species of the three groups of fungi characterized here on the basis of their energy source acquisition have differing potentials for becoming problem organisms following introduction as alien fungi new to Iowa. The decomposer group of fungi that obtain an energy supply by action of extracellular enzyme activity on dead plant tissues typically have perennial mycelium, are cosmopolitan in distribution, and are unlikely to become problems even if established. The second group, the mycorrhizal/lichen group are highly specific in their relationships. The mycorrhizal fungus group have a potential for being introduced as mycorrhiza already established with the roots of particular …


More Than A Century Of Change In The Ames, Iowa Flora (1859-2000), William R. Norris, Mark P. Widrlechner, Deborah Q. Lewis, Jimmie D. Thompson, Richard O. Pope Dec 2001

More Than A Century Of Change In The Ames, Iowa Flora (1859-2000), William R. Norris, Mark P. Widrlechner, Deborah Q. Lewis, Jimmie D. Thompson, Richard O. Pope

Journal of the Iowa Academy of Science: JIAS

We compared two floras compiled in Ames, Iowa: (1) an "historic" flora based on two published floras (1871, 1890) and on 1450 herbarium voucher specimens of plants collected in Ames between 1859 and 1899, and (2) a "current" flora compiled by us during recent fieldwork (1990-2000). Our goals were to determine 1) long-term changes in composition (i.e., the proportion of native species) over time, 2) long-term changes in the abundance of individual plant species over time, and 3) the extent of gains and losses of native and non-native plant species. We found that the proportion of native species declined over …


Exotic And Invasive Woody Plant Species In Iowa, Donald R. Farrar Dec 2001

Exotic And Invasive Woody Plant Species In Iowa, Donald R. Farrar

Journal of the Iowa Academy of Science: JIAS

Seventy species and hybrids of exotic woody trees, shrubs, and vines have naturalized in Iowa. Nearly half of these species (31) have become invasive pests in parts of the state or have potential do so. Most of the seriously invasive species are spread by bird ingestion of whole fruits. Widespread dispersal by birds hinders eradication efforts and should be considered a trait indicative of potential invasiveness. The economic and ecological values of Iowa forests are seriously compromised by exotic invasive woody species, especially where forests recovering from cropland and pasture are dominated by exotic species. Thus, a simple measure of …


Forest Invasives In Iowa: Current Problems And Future Issues, John Walkowiak, John Haanstad Dec 2001

Forest Invasives In Iowa: Current Problems And Future Issues, John Walkowiak, John Haanstad

Journal of the Iowa Academy of Science: JIAS

Iowa's forest resources of primarily deciduous trees covers over 0.8 million hectares (2 million acres) of upland and floodplain sites too steep or too wet for traditional row crop agriculture. These limited natural forests along with urban trees and shelterbelts plantings of trees are critical for environmental and economic enhancement in the state. Although not yet established in the state, exotic insects, such as gypsy moth, Asian longhorned beetle, and pine shoot beetle, threaten native tree vitality. Established exotic diseases such as oak wilt and Dutch elm disease continue to plague the survival of Iowa's oak and elm resources, respectively. …


Back Cover Dec 2001

Back Cover

Journal of the Iowa Academy of Science: JIAS

No abstract provided.


Cover - Table Of Contents Dec 2001

Cover - Table Of Contents

Journal of the Iowa Academy of Science: JIAS

No abstract provided.


Purple Loosestrife: History, Management, And Biological Control In Iowa, Amy P. Wiebe, John J. Obrycki Dec 2001

Purple Loosestrife: History, Management, And Biological Control In Iowa, Amy P. Wiebe, John J. Obrycki

Journal of the Iowa Academy of Science: JIAS

Purple loosestrife (Lythrum salicaria) is an invasive plant species infesting wetlands in North America. Biodiversity and wetland habitat quality are reduced following purple loosestrife establishment. Several management tactics, including cultural, mechanical, and chemical controls, have had limited success in reducing the spread of purple loosestrife. Beginning in the 1990s, a biological control program has introduced several species of natural enemies from Europe that feed on purple loosestrife. Since 1994, Iowa State University has reared and released two species of beetles that feed on purple loosestrife, Galerucella calmariensis and G. pusilla. Biological control is one component of an integrated purple loosestrife …


History And Development Of The Eurasian Watermilfoil Program In Iowa, Gary S. Phillips Dec 2001

History And Development Of The Eurasian Watermilfoil Program In Iowa, Gary S. Phillips

Journal of the Iowa Academy of Science: JIAS

Following a concerted effort by citizens of the Iowa Great Lakes area to address the threat posed by Eurasian watermilfoil (Myriophyllum spicatum L.) to waterbodies in Iowa, the Iowa Eurasian Watermilfoil Law was passed in 1996 by the Iowa legislature. Passage of this law led to the establishment of the Eurasian Watermilfoil Program in July 1996 to address the requirements specified by this legislation. Since establishment of the Eurasian Watermilfoil Program, numerous activities have been carried out to address the threat posed to aquatic ecosystems by Eurasian watermilfoil. These include public awareness and education, boat access monitoring, aquatic vegetation monitoring, …


Ecological Problems With Iowa's Invasive And Introduced Fishes, Neil P. Bernstein, John R. Olson Dec 2001

Ecological Problems With Iowa's Invasive And Introduced Fishes, Neil P. Bernstein, John R. Olson

Journal of the Iowa Academy of Science: JIAS

Since the time of European settlement, at least 59 non-indigenous fish species have been introduced, reached, or moved within Iowa waters. At least 28 nonnative fish species have been introduced into, or reported from Iowa waters since settlement. Of that number, 10 are established at this time through natural reproduction. In addition, many species of native fishes have been translocated within the state, and we provide documentation for 31 of these species. Two translocated species, gizzard shad (Dorosoma cepedianum) and yellow bass (Marone mississippiensis), have had adverse impacts on Iowa's aquatic ecosystems. While many introductions are thought to be benign, …


Invasive Birds In Iowa: Status, Problems, And Threats, James J. Dinsmore Dec 2001

Invasive Birds In Iowa: Status, Problems, And Threats, James J. Dinsmore

Journal of the Iowa Academy of Science: JIAS

A total of 18 invasive bird species has been introduced into or have expanded their range to include Iowa. These include ten non-North American species, one North American species that has been displaced and now is established in Iowa, and seven native species that have been released to reestablish Iowa populations. Twelve of those are regularly occurring species in Iowa, and they comprise 3.0% (12 of 404) of the species known from Iowa and 5% (10 of 199) of Iowa's nesting avifauna. These percentages are similar to those found in neighboring states. Several more species are likely to become established …


Anthropogenic Influences And Meteorological Effects: How They Are Changing The Sand Beaches In Southern Maine, Heather W. Heinze Dec 2001

Anthropogenic Influences And Meteorological Effects: How They Are Changing The Sand Beaches In Southern Maine, Heather W. Heinze

Electronic Theses and Dissertations

Although sand beaches in southern Maine comprise only a small segment of the coastline, they are economically important to the state. From September 1999-March 2001, volunteers made monthly topographic profiles along nine beaches in southern Maine to monitor changes. The volunteers used the Emery Method of beach profiling to take simultaneous measurements at spring low tide. The beaches are significantly different with respect to physiography, incident wave energy and direction, available sediment supply and extent of development. An average of the profiles for each category demonstrates that the undeveloped beaches experienced regular seasonal fluctuations and a consistent berm elevation from …


Existence Of Solutions Of The Classical Yang-Baxter Equation For A Real Lie Algebra, Jorg Feldvoss Dec 2001

Existence Of Solutions Of The Classical Yang-Baxter Equation For A Real Lie Algebra, Jorg Feldvoss

University Faculty and Staff Publications

We characterize finite-dimensional Lie algebras over the real numbers for which the classical Yang-Baxter equation has a non-trivial skew-symmetric solution (resp. a non-trivial solution with invariant symmetric part). Equivalently, we obtain a characterization of those finite-dimensional real Lie algebras which admit a non-trivial (quasi-) triangular Lie bialgebra structure.


Effects Of A Large Mesospheric Temperature Enhancement On The Hydroxyl Rotational Temperature As Observedfrom The Ground, S. M.L. Melo, R. P. Lowe, W. R. Pendleton Jr., Michael J. Taylor, B. Williams, C. Y. She Dec 2001

Effects Of A Large Mesospheric Temperature Enhancement On The Hydroxyl Rotational Temperature As Observedfrom The Ground, S. M.L. Melo, R. P. Lowe, W. R. Pendleton Jr., Michael J. Taylor, B. Williams, C. Y. She

All Physics Faculty Publications

The rotational temperature obtained from the rotational population distribution in the bands of the hydroxyl airglow has been shown to be a suitable proxy for the temperature at a height of 87 km [She and Lowe, 1998]. In this paper we examine in detail simultaneous observations on November 2–3, 1997, at Fort Collins, Colorado (41°N, 105°W), with both a sodium temperature lidar and the Coupling, Energetics, and Dynamics of Atmospheric Regions (CEDAR) OH mesospheric temperature mapper during which significant differences between the hydroxyl and lidar temperatures occur. The large differences are associated with a major temperature enhancement in the region …


Meeting Medical Terminology Needs: The Ontology-Enhanced Medical Concept Mapper, Gondy Leroy, Hsinchun Chen Dec 2001

Meeting Medical Terminology Needs: The Ontology-Enhanced Medical Concept Mapper, Gondy Leroy, Hsinchun Chen

CGU Faculty Publications and Research

This paper describes the development and testing of the Medical Concept Mapper, a tool designed to facilitate access to online medical information sources by providing users with appropriate medical search terms for their personal queries. Our system is valuable for patients whose knowledge of medical vocabularies is inadequate to find the desired information, and for medical experts who search for information outside their field of expertise. The Medical Concept Mapper maps synonyms and semantically related concepts to a user's query. The system is unique because it integrates our natural language processing tool, i.e., the Arizona (AZ) Noun Phraser, with human-created …


Meeting Medical Terminology Needs: The Ontology-Enhanced Medical Concept Mapper, Gondy Leroy, Hsinchun Chen Dec 2001

Meeting Medical Terminology Needs: The Ontology-Enhanced Medical Concept Mapper, Gondy Leroy, Hsinchun Chen

CGU Faculty Publications and Research

This paper describes the development and testing of the Medical Concept Mapper, a tool designed to facilitate access to online medical information sources by providing users with appropriate medical search terms for their personal queries. Our system is valuable for patients whose knowledge of medical vocabularies is inadequate to find the desired information, and for medical experts who search for information outside their field of expertise. The Medical Concept Mapper maps synonyms and semantically related concepts to a user's query. The system is unique because it integrates our natural language processing tool, i.e., the Arizona (AZ) Noun Phraser, with human-created …


Three Dimensional Hydrodynamic Modeling Study, Craney Island Eastward Expansion, Lower James River And Elizabeth River, Virginia, Harry V. Wang, S. C. Kim, John D. Boon, A. Y. Kuo, G. M. Sisson, J. M. Brubaker, J. P-Y. Maa Dec 2001

Three Dimensional Hydrodynamic Modeling Study, Craney Island Eastward Expansion, Lower James River And Elizabeth River, Virginia, Harry V. Wang, S. C. Kim, John D. Boon, A. Y. Kuo, G. M. Sisson, J. M. Brubaker, J. P-Y. Maa

Reports

The Craney Island Eastward Expansion Hydrodynamic Model Study was conducted in three phases: 1) model calibration and verification for the Elizabeth River, 2) model testing of four Craney Island expansion options using single variable runs (using a single variable, tidal range, for model input), 3) model testing of two expansion options using historical runs (using multiple variables in real time for model input). The expansion option designs were evaluated for both global and local hydrodynamic change through simulation comparisons with the Base Case condition.


Prediction Of The Crystal Structures Of Perovskites Using The Software Program Spuds, Michael W. Lufaso, Patrick M. Woodward Dec 2001

Prediction Of The Crystal Structures Of Perovskites Using The Software Program Spuds, Michael W. Lufaso, Patrick M. Woodward

Chemistry Faculty Research and Scholarship

The software program SPuDS has been developed to predict the crystal structures of perovskites, including those distorted by tilting of the octahedra. The user inputs the composition and SPuDS calculates the optimal structure in ten different Glazer tilt systems. This is performed by distorting the structure to minimize the global instability index, while maintaining rigid octahedra. The location of the A-site cation is chosen so as to maximize the symmetry of its coordination environment. In its current form SPuDS can handle up to four different A-site cations in the same structure, but only one octahedral ion. Structures predicted …


Effect Of Rare Locally Ordered Regions On A Disordered Itinerant Quantum Antiferromagnet With Cubic Anisotropy, Rajesh S. Narayanan, Thomas Vojta Dec 2001

Effect Of Rare Locally Ordered Regions On A Disordered Itinerant Quantum Antiferromagnet With Cubic Anisotropy, Rajesh S. Narayanan, Thomas Vojta

Physics Faculty Research & Creative Works

We study the quantum phase transition of an itinerant antiferromagnet with cubic anisotropy in the presence of quenched disorder, paying particular attention to the locally ordered spatial regions that form in the Griffiths region. We derive an effective action where these rare regions are described in terms of static annealed disorder. A one-loop renormalization-group analysis of the effective action shows that for order-parameter dimensions p<4, the rare regions destroy the conventional critical behavior, and the renormalized disorder flows to infinity. For order-parameter dimensions p>4, the critical behavior is not influenced by the rare regions; it is described by the conventional dirty cubic fixed point. We also discuss the influence of the rare regions on the fluctuation-driven first-order transition …


Lort And Young Rivers Catchment : Catchment Appraisal 2001, Jamie Bowyer, Esperance Catchment Support Team (Wa) Dec 2001

Lort And Young Rivers Catchment : Catchment Appraisal 2001, Jamie Bowyer, Esperance Catchment Support Team (Wa)

Resource management technical reports

Using the Rapid Catchment Appraisal process, this report summarises current information for the Lort and Young Rivers Catchment, 75 kilometres west of Esperance in Western Australia. The Rapid Catchment Appraisal (RCA) process is one of the processes included in the strategy to tackle salinity and its management in Western Australia. The RCA process provides a 'snap shot' of information on the risk and impact to agricultural production and natural resources within regional geographic catchments.


Yarra Yarra Catchment : Rapid Catchment Appraisal Report 2001, M Clarke Dec 2001

Yarra Yarra Catchment : Rapid Catchment Appraisal Report 2001, M Clarke

Resource management technical reports

Using the Rapid Catchment Appraisal process, this report summarises current information for the Yarra Yarra Catchment, Northern Agricultural Region in Western Australia. The Rapid Catchment Appraisal (RCA) process is one of the processes included in the strategy to tackle salinity and its management in Western Australia. The RCA process provides a 'snap shot' of information on the risk and impact to agricultural production and natural resources within regional geographic catchments.


The Effects Of Temperature On The Survival, Growth And Development Of Larvae Of Two Blue Mussel Species (Mytilus Edulis And Mytilus Trossulus), Susan Hayhurst Dec 2001

The Effects Of Temperature On The Survival, Growth And Development Of Larvae Of Two Blue Mussel Species (Mytilus Edulis And Mytilus Trossulus), Susan Hayhurst

Electronic Theses and Dissertations

Factors affecting the distribution of Mytilus edulis and Mytilus trossulus in the Gulf of Maine are of great interest because of the blue mussel's economic and ecological importance. Genetic surveys of blue mussel populations indicate that eastern Maine represents the southern distributional limit for M. trossulus but that M. edulis is common throughout the Gulf of Maine. Because hydrographic features in the Gulf of Maine confound temperature variation and larval dispersal patterns, the relative importance of these potential range-limiting mechanisms cannot be ascertained from the distribution of adult mussels. Given that larvae are more vulnerable than adults to temperature extremes, …


The Role Of Water Motion In Algal Reproduction, Richard Gordon Dec 2001

The Role Of Water Motion In Algal Reproduction, Richard Gordon

Electronic Theses and Dissertations

Environmental conditions, such as water motion, can influence fertilization success and spore dispersal in marine algae. Previous studies on fucoid algae showed that gamete release is restricted to, or enhanced by, periods of low water motion. Few other algal taxa have been investigated, however, including species with an alternation of generations. I investigated gamete and spore release in the macroalgae Alaria esculenta and Ulva lactuca, as well as in the diatom Pseudo-nitachia multiseries to determine if water motion is inhibitory or stimulates propagule production and release. I used orbital shakers to simulate water motion; these were interspersed with stationary platforms …


Gametogenic Cycles Of Marine Mussels, Mytilus Edulis And Mytilus Trossulus, In Cobscook Bay, Maine, Aaron P. Maloy Dec 2001

Gametogenic Cycles Of Marine Mussels, Mytilus Edulis And Mytilus Trossulus, In Cobscook Bay, Maine, Aaron P. Maloy

Electronic Theses and Dissertations

The Mytilus edulis species complex includes three smooth-shelled blue mussels, M. edulis (Linnaeus 1 75 8), M trossulus (Gould 1 850), and M galloprovincialis (Lamarck 18 19). When any two of theses species occur sympatrically, hybridization and backcrossing of hybrid and parental genotypes is evident. Despite introgression of genes between taxa their genetic integrity is maintained. To test the hypothesis that a temporal variation in species-specific spawning times is the mechanism limiting hybridization and maintaining genetic integrity in a M edulis and M. trossulus hybrid zone in eastern Maine, mussels were sampled on monthly to semi-monthly intervals throughout 2000 from …


Solid Waste Management In Oil And Gas Pipelines Application To Asab Field, Abdulqader M Alkamali Dec 2001

Solid Waste Management In Oil And Gas Pipelines Application To Asab Field, Abdulqader M Alkamali

Theses

Managing solid waste, and any other wastes in general, is an environmental need, an economical choice and a legal requirement. Preserving the environment while lowering the cost becomes a necessity when liabilities are of concern.

Solid wastes generated from oil and gas industrial activities are very diverse in their characteristics, large in their amounts and many of which are hazardous in nature. Thus, the need to manage these wastes is an obvious mandate. Oil and gas industrial activities include exploration, drilling, production, processing, refining, manufacturing and exporting. Associated with these activities, other supporting services; such as, maintenance, civil, transportation, storage, …


Petrological And Geochemical Analyses And Economic Potential Of Some Milestones And Siliceous Rocks In Northern United Arab Emirates., Mohammed Ahmed A. Ibrahim Dec 2001

Petrological And Geochemical Analyses And Economic Potential Of Some Milestones And Siliceous Rocks In Northern United Arab Emirates., Mohammed Ahmed A. Ibrahim

Theses

Combined microscopic, heavy mineral, X-ray diffraction and chemical analyses have been carried out on the Jurassic limestone, the upper cretaceous Hawasina cherts and the coastal and inland sand dunes in several localities in the Ras Al Khaimah Emirate. The obtained results revealed that a number of represents cherts subfacies; namely: ferruginous radiolarian ribbon chert, carbonaceous radiolarian ribbon chert, colloform ribbon chert, calcareous chert and siliceous mud stone. These rocks consist of (in order of decreasing abundance): quartz, calcite, dolomite and hematite. The carbonate rocks are made up of lime mudstone, wackestone; pack stone and, rarely, crystalline limestone. Various types of …


Hazardous Materials Transportation Flow Survey: An Evaluation Of Hazardous Materials Transported In Washington County., Daniel John O'Brien Dec 2001

Hazardous Materials Transportation Flow Survey: An Evaluation Of Hazardous Materials Transported In Washington County., Daniel John O'Brien

Electronic Theses and Dissertations

This study examines the transportation of hazardous materials through Washington County, Tennessee. This study incorporates federal, state, and local data in assessing current transportation trends. Data gathering activities included local chemical inventories, hazardous materials transportation flow surveys, hazardous materials rail transportation trends, and hazardous materials incident data.

All data were compiled and then analyzed to identify hazardous materials transportation trends in Washington County, Tennessee. This information is pertinent to emergency planners for the preparation of hazardous materials transportation incidents. The data gathered further revealed the need for this type of study to identify changing trends in the transportation of hazardous …


A Meta-Analysis And Risk Assessment Of Heavy Metal Uptake In Common Garden Vegetables., Trent David Lecoultre Dec 2001

A Meta-Analysis And Risk Assessment Of Heavy Metal Uptake In Common Garden Vegetables., Trent David Lecoultre

Electronic Theses and Dissertations

Peer reviewed literature was searched to identify research pertaining to the uptake of heavy metals (As, Cd, Pb and Zn) by vegetables (cabbage, carrot, lettuce, and radish). The objectives of this research were to 1) determine the relationship between heavy metal concentrations in the soil and heavy metal concentrations in vegetables, and 2) determine the level of risk associated with exposure to heavy metals through ingestion of contaminated vegetables. Highly variable estimates and biologically implausible regression equations resulted from this meta-analysis. Exposure to arsenic through the ingestion of lettuce grown on contaminated soil significantly increases cancer risk, especially in children. …


Ecological Characterization Of Stormwater Detention Ponds In Virginia's Coastal Plain, Rebecca Jo Thomas, Carl H. Hershner Dec 2001

Ecological Characterization Of Stormwater Detention Ponds In Virginia's Coastal Plain, Rebecca Jo Thomas, Carl H. Hershner

Reports

No abstract provided.


The Suitability Of Reclaimed Agricultural Lands Along The Lower Colorado River For Native Riparian Habitat Restoration, Patti Aaron Dec 2001

The Suitability Of Reclaimed Agricultural Lands Along The Lower Colorado River For Native Riparian Habitat Restoration, Patti Aaron

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this paper is to determine the suitability of agricultural lands for use in native riparian restoration efforts under development for the Lower Colorado River Multi-Species Conservation Program. Assuming these fields are productive for crops, would they be productive for cottonwood-willow restoration? There are two aspects to consider: (1) the edaphic conditions required for three major LCR agricultural crops; alfalfa, cotton, and wheat, and (2) whether those conditions are consistent with the conditions required for the restoration of native LCR riparian habitat, primarily Fremont cottonwood (Populus fremontii) and Goodding willow (Salix gooddingii). Using the case study research approach …


Dark Production: A Significant Source Of Oceanic Cos, M. Von Hobe, Gregory A. Cutter, A. J. Kettle, M. O. Andreae Dec 2001

Dark Production: A Significant Source Of Oceanic Cos, M. Von Hobe, Gregory A. Cutter, A. J. Kettle, M. O. Andreae

OES Faculty Publications

Carbonyl sulfide (COS) in air and dissolved in seawater was determined during a cruise in August 1999 in the Sargasso Sea in the northwest Atlantic Ocean. Dissolved concentrations at the sea surface displayed only a weak diel cycle with a mean of 8.6 ± 2.8 pmol dm−3 owing to low abundance of photochemical precursors and high temperatures causing rapid hydrolysis. Depth profiles measured over the oceanic mixed layer revealed significant vertical gradients of COS concentration with higher values at the surface, suggesting that the rate of photochemical production at the surface exceeds the rate of vertical mixing. The mean …