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1998

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Articles 1711 - 1740 of 2574

Full-Text Articles in Physical Sciences and Mathematics

Back Cover Jan 1998

Back Cover

Journal of the Iowa Academy of Science: JIAS

No abstract provided.


Iowa's Wetlands, Present And Future With A Focus On Prairie Potholes, R. A. Bishop, J. Joens, J. Zohrer Jan 1998

Iowa's Wetlands, Present And Future With A Focus On Prairie Potholes, R. A. Bishop, J. Joens, J. Zohrer

Journal of the Iowa Academy of Science: JIAS

The vast prairie marsh-pothole complex that historically covered approximately 7 .6 millions acres in Iowa was reduced to less than 30,000 acres by 1980 when it was estimated that only 5,000 acres of prairie marsh and pothole habitat remained in private ownership. A bleak outlook for the future of wetlands was presented by Bishop (1981)." This outlook changed with the development of the North American Waterfowl Management Plan and the passage of two important pieces of legislation: the North American Wetlands Conservation Act and the Food Security Act of 1985. Protection of existing wetlands was afforded through the Swampbuster provision …


Front Matter Jan 1998

Front Matter

Journal of the Iowa Academy of Science: JIAS

No abstract provided.


Checklist Of Instructions For Authors Jan 1998

Checklist Of Instructions For Authors

Journal of the Iowa Academy of Science: JIAS

No abstract provided.


Iowa's Declining Flora And Fauna: A Review Of Changes Since 1980 And An Outlook For The Future, Neil P. Bernstein Jan 1998

Iowa's Declining Flora And Fauna: A Review Of Changes Since 1980 And An Outlook For The Future, Neil P. Bernstein

Journal of the Iowa Academy of Science: JIAS

The status of Iowa's biodiversity was first summarized at a 1980 Iowa Academy of Science (IAS) symposium that was published in The Proceedings of the Iowa Academy of Science (Vol. 88, No. 1) in 1981. The 1980 symposium was updated in a recent IAS symposium, and the proceedings from this symposium are published, for the most part, in volume 105 of this journal. Most of the authors noted some positive trends, but, overall, species declines and habitat destruction remained a concern.


Editorial Board & Iowa Academy Of Science Officers And Directors Jan 1998

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 1998

Cover - Table Of Contents

Journal of the Iowa Academy of Science: JIAS

No abstract provided.


Lithologic And Structural Interpretation Of Gravity Data, Northeastern Iowa, Curtiss J. Hella, Richard L. Kellogg Jan 1998

Lithologic And Structural Interpretation Of Gravity Data, Northeastern Iowa, Curtiss J. Hella, Richard L. Kellogg

Journal of the Iowa Academy of Science: JIAS

A gravity survey was conducted over approximately 4600 square km of northeast Iowa. It was undertaken to provide detailed gravity coverage at approximately 1.6 km intervals and to model the source of several significant gravity and magnetic anomalies. 1,460 gravity stations were occupied in the survey area. Bouguer gravity and residual gravity anomaly maps were prepared, the latter using band-pass filter and trend-surface analysis techniques. The residual maps reveal that the large oval Bouguer gravity anomaly centered beneath Decorah can be traced to the southern border of the survey. Profiles crossing this feature were prepared from the Bouguer map and …


Awards And Recognition, Iowa Academy Of Science, 1998 Jan 1998

Awards And Recognition, Iowa Academy Of Science, 1998

Journal of the Iowa Academy of Science: JIAS

No abstract provided.


Back Cover Jan 1998

Back Cover

Journal of the Iowa Academy of Science: JIAS

No abstract provided.


Continuous Monitoring Of Star's Main Time Projection Chamber, Wilfred J. Braithwaite, Edwin S. Braithwaite Jan 1998

Continuous Monitoring Of Star's Main Time Projection Chamber, Wilfred J. Braithwaite, Edwin S. Braithwaite

Journal of the Arkansas Academy of Science

STAR refers to the Solenoidal Tracking instrument At RHIC (the Relativistic Heavy Ion Collider). For momenta above 500 MeV/c charged kaons are not separated from pions within STAR's Main TPC (Time Projection Chamber) by track density alone and they are poorly separated below 500 MeV/c, even when using information from other sources like the vertex tracker. Within the TPC large numbers of kaons and pions decay into muons (and undetected neutrinos). Earlier work has shown parent pions and kaons whose decays are detected within a TPC may be distinguished uniquely from each other in a two-dimensional plot of muon-emission angle …


The Occurrence Of Pcbs And Chlorinated Pesticide Contaminants In Bottlenose Dolphins (Tursiops Truncatus) In A Resident Community: Comparison With Age, Gender And Birth Order, Kathleen M. Kuss Jan 1998

The Occurrence Of Pcbs And Chlorinated Pesticide Contaminants In Bottlenose Dolphins (Tursiops Truncatus) In A Resident Community: Comparison With Age, Gender And Birth Order, Kathleen M. Kuss

HCNSO Student Theses and Dissertations

Tissue samples from twenty bottlenose dolphins from a stable, residential community of coastal dolphins in the western Gulf of Mexico were analyzed for toxic PCB congeners and chlorinated pesticides. The tissues analyzed (blubber and melon) were from known individuals in a long-term (27+ y) study that stranded and were recovered for necropsy. Substantial demographic data were available on these individuals and utilized in the analysis of maternal transfer of organochlorines to young.

The male dolphins in this study were shown to accumulate organochlorine contaminants with age. In female dolphins the organochlorine levels were found to decline with age. These …


Variability In Copepod Hatching Success: Observations On Natural Populations And Experiments On The Role Of Maternal Diet, Carol A. Burkart Jan 1998

Variability In Copepod Hatching Success: Observations On Natural Populations And Experiments On The Role Of Maternal Diet, Carol A. Burkart

HCNSO Student Theses and Dissertations

The objectives of this study were (1) to survey the percent hatching success of eggs produced by calanoid copepod species from a variety of ecosystems (i.e., polar, temperate, and sub-tropical), (2) to describe the relationship between egg production, hatching success of Acartia tonsa and the physical and food environments of Florida Bay, and (3) to describe the relationships between hatching success and maternal diet. In order to fulfill the first objective, an incubation system was designed to allow the monitoring of eggs at sea for extended periods of time. The second objective was addressed with a series of egg production …


Determination Of Bioavailable Contaminants In The Lower Missouri River Following The Flood Of 1993, Jimmie Petty, Barry Poulton, Colette Charbonneau, James Huckins, Susan Jones, Jennifer Cameron, Harry Prest Jan 1998

Determination Of Bioavailable Contaminants In The Lower Missouri River Following The Flood Of 1993, Jimmie Petty, Barry Poulton, Colette Charbonneau, James Huckins, Susan Jones, Jennifer Cameron, Harry Prest

United States Geological Survey: Staff Publications

The semipermeable membrane device (SPMD) technology was employed to determine the presence of bioavailable organochlorine pesticides (OCs), polychlorinated biphenyls (PCBs), and polyaromatic hydrocarbons (PAHs) in the water of the main stem of the lower Missouri River and three of its tributaries. The SPMDs were deployed in 1994 following the extensive flood of 1993. Specifically, the SPMDs were deployed for 28 days at Wilson State Park, IA; Nebraska City, NE; Parkville, MO; the Kansas River in Kansas City, KS; Napoleon, MO; the Grand River; Glasgow, MO; the Missouri River upstream from the confluence of the Gasconade River; the Gasconade River; and …


Continuous Lake-Sediment Records Of Glaciation In The Sierra Nevada Between 52,600 And 12,500 14c Yr B.P., Larry Benson, Howard M. May, Ronald C. Antweiler, Terry I. Brinton, Michaele Kashgarian, Joseph P. Smoot, Steve P. Lund Jan 1998

Continuous Lake-Sediment Records Of Glaciation In The Sierra Nevada Between 52,600 And 12,500 14c Yr B.P., Larry Benson, Howard M. May, Ronald C. Antweiler, Terry I. Brinton, Michaele Kashgarian, Joseph P. Smoot, Steve P. Lund

United States Geological Survey: Staff Publications

The chemistry of the carbonate-free clay-size fraction of Owens Lake sediments supports the use of total organic carbon and magnetic susceptibility as indicators of stadial-interstadial oscillations, Owens Lake records of total organic carbon, magnetic susceptibility, and chemical composition of the carbonate-free, clay-size fraction indicate that Tioga glaciation began ~24,500 and ended by ~13,600 14C yr B.P. Many of the components of glacial rock flour (e.g., TiO2 , MnO, BaO) found in Owens Lake sediments achieved maximum values during the Tioga glaciation when valley glaciers reached their greatest extent. Total organic carbon and Si02 (amorphous) concentrations reached minimum values …


Stable Isotopes And Sediments From Pickerel Lake, South Dakota, Usa: A 12ky Record Of Environmental Changes, Antje Schwalb, Walter E. Dean Jan 1998

Stable Isotopes And Sediments From Pickerel Lake, South Dakota, Usa: A 12ky Record Of Environmental Changes, Antje Schwalb, Walter E. Dean

United States Geological Survey: Staff Publications

Sedimentological parameters and stable O- and C-isotopic composition of marl and ostracode calcite selected from a 17.7 m long core from the 8 m deep center of Pickerel Lake, northeastern South Dakota, provide one of the longest (ca. 12ky) paleoenvironmental records from the northern Great Plains. The late Glacial to early Holocene climate in the northern Great Plains was characterized by changes from cold and wet to cold and dry, and back to cold and wet conditions. These climatic changes were controlled by fluctuations in the positions of the Laurentide ice sheet and the extent of glacial Lake Agassiz. We …


An Evaluation Of Methods For Identifying And Interpreting Buried Soils In Late Quaternary Loess In Alaska, Daniel R. Muhs, Thomas A. Ager, Josh M. Been, Joseph G. Rosenbaum, Richard L. Reynolds Jan 1998

An Evaluation Of Methods For Identifying And Interpreting Buried Soils In Late Quaternary Loess In Alaska, Daniel R. Muhs, Thomas A. Ager, Josh M. Been, Joseph G. Rosenbaum, Richard L. Reynolds

United States Geological Survey: Staff Publications

The presence of buried soils in Alaskan loess is controversial, and therefore criteria for identifying buried soils in these deposits need to be evaluated. In this paper, morphologic and chemical criteria for identifying buried soils are evaluated by studying modern soils developed mostly in Holocene loess under tundra, boreal forest, and transitional coastal-boreal forest vegetation in different parts of Alaska. Data from modern Alaskan soils that developed under vegetation similar to that of the present indicate that soil morphology, organic-matter concentrations, and P concentrations can be useful diagnostic tools for identifying buried soils. Soil morphologic criteria, particularly horizon colors and …


Use Of Algal And Macroinvertebrate Indicators To Assess The Impact Of Agricultural Practices On Surface Water Quality In The Mammoth Cave National Park Region, Kentucky, Jeffrey D. Jack Jan 1998

Use Of Algal And Macroinvertebrate Indicators To Assess The Impact Of Agricultural Practices On Surface Water Quality In The Mammoth Cave National Park Region, Kentucky, Jeffrey D. Jack

KWRRI Research Reports

The karst aquifer underlying the Mammoth Cave area supports a unique and diverse cave aquatic ecosystem as well as providing the principal source of drinking water for many local residents of the region. This unique and fragile ecosystem is surrounded by one of the most intensively used agricultural areas in the Commonwealth with more than 80% of the surrounding region used in beef, dairy, burley tobacco and alfalfa production. Agricultural practices resulting in run-off of pollutants into the aquifer via sinkholes and sinking streams have a pronounced impact on an important drinking water source and on the cave ecosystem. The …


Cahit Arf's Contribution To Algebraic Number Theory And Related Fields, Masatoshi G. İkeda Jan 1998

Cahit Arf's Contribution To Algebraic Number Theory And Related Fields, Masatoshi G. İkeda

Turkish Journal of Mathematics

No abstract provided.


Timelike Ruled Surfaces In The Minkowski 3-Space-Ii, A. Turgut, H. H. Hacisali̇oğlu Jan 1998

Timelike Ruled Surfaces In The Minkowski 3-Space-Ii, A. Turgut, H. H. Hacisali̇oğlu

Turkish Journal of Mathematics

This paper is devoted to a study of timelike ruled surfaces in three dimensional Minkowski space obtained by a spacelike straight line moving along a timelike curve. The central point, the curve of striction and the distribution parameter of a timelike ruled surface in Minkowski 3-space are considered, and some theorems relating to their structure are obtained. In addition, some results about developable timelike ruled surfaces are also given.


A Berry-Esseen Bound For Empty Boxes Statistic On The Scheme An Allocations Of Several Type Balls, S.A. Mirakhmedov, O. Saidova Jan 1998

A Berry-Esseen Bound For Empty Boxes Statistic On The Scheme An Allocations Of Several Type Balls, S.A. Mirakhmedov, O. Saidova

Turkish Journal of Mathematics

A Berry-Esseen bound for the number of empty cells in the scheme of independent and random allocation of balls of $s$ type into different cells is obtained.


Weighted Ergodic Averages, M.D. Ha Jan 1998

Weighted Ergodic Averages, M.D. Ha

Turkish Journal of Mathematics

Let $(X, {\cal F}, \lambda)$ be the unit circle $\Bbb S^1 = \{z \in \Bbb C : z = 1\}$ with the usual $\sigma$-algebra ${\cal F}$ of Lebesgue measurable subsets and the normalized Lebesgue measure $\lambda$. Consider a sequence $\nu_n: \Bbb N \ra \Bbb R, \;\; \nu_n(k) \geq 0, \;\; \Sigma^{\infty}_{k=1} \nu_n(k) = 1$. For any measure-preserving $\tau : X \ra X$, this sequence induces a sequence $(T_n)^{\infty}_1$ of bounded, linear operators on $L^p(X), \;\; 1 \leq p \leq \infty$, by defining \[ T_n f = \sum^{\infty}_{k=1} \nu_n(k) \; f \circ \tau^k, \quad n = 1, 2, \ldots . \] …


Generalized Inverse Estimator And Comparison With Least Squares Estimator, S. Sakallıoğlu, F. Akdeniz Jan 1998

Generalized Inverse Estimator And Comparison With Least Squares Estimator, S. Sakallıoğlu, F. Akdeniz

Turkish Journal of Mathematics

Trenkler [13] described an iteration estimator. This estimator is defined as follows: for $0 < \gamma < 1/\lambda_i \max$ \[ \hat{\beta}_{m, \gamma} = \gamma \sum^m_{i=0} (1-\gamma X'X)^i X'y , \] where $\lambda_i$ are eigenvalues of $X'X$. In this paper a new estimator (generalized inverse estimator) is introduced based on the results of Tewarson [11]. A sufficient condition for the difference of mean square error matrices of least squares estimator and generalized inverse estimator to be positive definite (p.d.) is derived.


Direct Sums And The Schur Property, Betül Tanbay Jan 1998

Direct Sums And The Schur Property, Betül Tanbay

Turkish Journal of Mathematics

It is a known fact that $\ell^1$, the dual space of the null sequences $c_0$, has the Schur property, that is, weakly convergent sequences in $\ell^1$ are norm convergent. In this paper, we prove that if $(X_{\alpha})_{\alpha\in I}$ are Banach spaces and $X=(\oplus_{\alpha\in I}X_{\alpha})_1$ their $l_1$-sum, then the space $X$ has the Schur property iff each factor $X_{\alpha}$ has it.


Splitting In Locally Compact Abelian Groups, Peter Loth Jan 1998

Splitting In Locally Compact Abelian Groups, Peter Loth

Mathematics Faculty Publications

No abstract provided.


Stress And Structure Of Ni Monolayers On W(110): The Importance Of Lattice Mismatch, D. Sander, C. Schmidthals, Axel Enders, J. Kirschner Jan 1998

Stress And Structure Of Ni Monolayers On W(110): The Importance Of Lattice Mismatch, D. Sander, C. Schmidthals, Axel Enders, J. Kirschner

Axel Enders Publications

The combination of in situ stress measurements, low-energy electron diffraction, and scanning tunneling microscopy reveals the intimate relation between film structure and film stress for epitaxial growth of Ni on W(110) in the monolayer range. In contradiction to lattice mismatch considerations, we measure tremendous compressive stress in the pseudomorphic Ni film, where tensile film stress is expected from strain arguments. Surface stress of the film-substrate composite is proposed to be much more relevant for the description of film stress in the submonolayer range than lattice mismatch arguments are.


1998 File Geodatabase Containing Photo Point Locations, Aerial Photos, And Flight Maps, City Of Tampa Department Of Sanitary Sewers Bay Study Group, Pete Reehling, Richard Mckenzie Jan 1998

1998 File Geodatabase Containing Photo Point Locations, Aerial Photos, And Flight Maps, City Of Tampa Department Of Sanitary Sewers Bay Study Group, Pete Reehling, Richard Mckenzie

Data Sets

The Bay Study Group was created by the City of Tampa in 1976 to monitor the effects of pollution abatement that occurred in Hillsborough Bay when the city’s wastewater treatment plant was upgraded from primary to advanced treatment in 1979. The Bay Study Group documented a remarkable restoration of water quality parameters and biological indicators in Hillsborough Bay from the mid 1980s until 2009, when it was disbanded. This zip Geodatabase file contains the photo point locations, aerial photos, and flight maps for the year 1998.


Unrelieved Pain And Distress In Animals: An Analysis Of Usda Data On Experimental Procedures, Martin Stephens, Philip Mendoza, Adrianna Weaver, Tamara Hamilton Jan 1998

Unrelieved Pain And Distress In Animals: An Analysis Of Usda Data On Experimental Procedures, Martin Stephens, Philip Mendoza, Adrianna Weaver, Tamara Hamilton

Experimentation Collection

Pain and distress are core issues in the field of animal experimentation and in the controversy that surrounds it. We sought to add to the empirical base of the literature on pain and distress by examining government data on experimental procedures that caused unrelieved pain and distress (UPAD) in animals. Of the species regulated by the U.S. Department of Agriculture (USDA), most of the approximately 100,000 animals subjected to UP AD during the year analyzed (1992) were guinea pigs and hamsters. Most of these animals were used in industry laboratories for various testing procedures, primarily vaccine potency testing. We discuss …


Overview Of The 8th International Symposium On Vulcanospeleology, William R. Halliday Jan 1998

Overview Of The 8th International Symposium On Vulcanospeleology, William R. Halliday

International Journal of Speleology

In February 1998 the 8h International Symposium on Vulcanospeleology was hosted by CEGEA (Cave Exploration Group of East Africa) in Nairobi, Kenya: it was attended by 16 scientists coming from 4 continents. Pre- and Post- Symposium excursions allowed the participants to have an overview on the most important and famous volcanic cave of that area.


Volcanic Caves Of East Africa - An Overview, Jim W. Simons Jan 1998

Volcanic Caves Of East Africa - An Overview, Jim W. Simons

International Journal of Speleology

Numerous Tertiary to recent volcanoes are located in East Africa. Thus, much of the region is made up volcanic rock, which hosts the largest and greatest variety of East Africas caves. Exploration of volcanic caves has preoccupied members of Cave Exploration Group of East Africa (CEGEA) for the past 30 years. The various publications edited by CEGEA are in this respect a treasure troves of speleological information. In the present paper an overview on the most important volcanic caves and areas are shortly reported.