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2001

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Articles 2821 - 2850 of 3030

Full-Text Articles in Physical Sciences and Mathematics

Diagonal Lift In The Cotangent Bundle And Its Applications, Sezgi̇n Akbulut, Murat Özdemi̇r, Ari̇f A. Salimov Jan 2001

Diagonal Lift In The Cotangent Bundle And Its Applications, Sezgi̇n Akbulut, Murat Özdemi̇r, Ari̇f A. Salimov

Turkish Journal of Mathematics

The purpose of this paper is to define a diagonal lift ^{\mathcal{D }}g of a Riemannian metric g of a manifold M_{n} to the cotangent bundle T^{*}(M_{n}) of M_{n}, to associate with ^{\mathcal{D}}g an Levi-Civita connection of T^{*}(M_{n}) in a natural way and to investigate applications of the diagonal lifts.

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Lithospheric Flexure Of The Devils Lake Basin, North Dakota, Erica M. Peterson Jan 2001

Lithospheric Flexure Of The Devils Lake Basin, North Dakota, Erica M. Peterson

Theses and Dissertations

Devils Lake is the largest lake in a chain of approximately 20 interconnected lakes in east central North Dakota. The Devils Lake drainage basin of approximately 8,600 km2, lies in a bowl sculpted by glaciation; thus it is closed and receives and loses water only through precipitation and evapotranspiration. Since 1940, the lake level has risen 14.4 m due to increased precipitation. Geological data show that in the past 10,000 years the lake has alternately dried up and filled due to climate fluctuations (Murphy et al., 1997). During this time it has reached its spill elevation of 444. 7 m …

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Incorporating Window-Based Passage-Level Evidence In Document Retrieval, Wensi Xi, Richard Xu-Rong, Christopher Soo Guan Khoo, Ee Peng Lim Jan 2001

Incorporating Window-Based Passage-Level Evidence In Document Retrieval, Wensi Xi, Richard Xu-Rong, Christopher Soo Guan Khoo, Ee Peng Lim

Research Collection School Of Computing and Information Systems

This study investigated whether document retrieval can be improved if documents are divided into smaller sub-documents or passages and the retrieval score for these passages are incorporated in the final retrieval score for the whole document. The documents were segmented by sliding a window of a certain size across the document and extracting the words displayed each time the window stopped. A retrieval score was calculated for each of the passages extracted and the highest score obtained by a passage of that size was taken as the document’s passage-level score for that window size. A range of window sizes was …

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Accurate Parameter Estimation For An Articulatory Speech Synthesizer With An Improved Neural Network Mapping, Hali̇s Altun, Tankut Yalçinöz, K. Mervyn Curtis Jan 2001

Accurate Parameter Estimation For An Articulatory Speech Synthesizer With An Improved Neural Network Mapping, Hali̇s Altun, Tankut Yalçinöz, K. Mervyn Curtis

Turkish Journal of Electrical Engineering and Computer Sciences

Neural network (NN) applications have recently been employed to extract the parameters of an articulatory speech synthesizer from a given speech signal. Results from these attempts showed that a single NN is insufficient to cover all of the possible configurations uniquely. Moreover, apart from their computational advantages, NN mapping is so far not superior to the other mapping techniques [1]. Thus there is a clear need to improve NN solution to the inverse problem. Results from our earlier experiments with an articulatory speech synthesizer have shown that the statistical characteristic of the articulatory target pattern vectors can be exploited for …

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Ota-C Based Proportional-Integral-Derivative (Pid) Controller And Calculating Optimum Parameter Tolerances, Cevat Erdal, Ali̇ Toker, Cevdet Acar Jan 2001

Ota-C Based Proportional-Integral-Derivative (Pid) Controller And Calculating Optimum Parameter Tolerances, Cevat Erdal, Ali̇ Toker, Cevdet Acar

Turkish Journal of Electrical Engineering and Computer Sciences

Proportional-integral-derivative (PID) controllers are one of the most important control elements used in the process control industry. In practice, operational amplifiers are generally used in analog controllers. On the other hand, the operational transconductance amplifiers recently developed, which have some positive properties compared to operational amplifiers, are not used in analog controller design at present. Furthermore, the optimum parameter tolerances for the proposed PID circuit by the use of parameter sensitivities are determined. These tolerances keep the relative error at the output of the controller due to parameter variations in the tolerance region.

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Isolated Ramp Metering Feedback Control Utilizing Mixed Sensitivity For Desired Mainline Density And The Ramp Queues, Pushkin Kachroo, Kaan Ozbay, Donald E. Grove Jan 2001

Isolated Ramp Metering Feedback Control Utilizing Mixed Sensitivity For Desired Mainline Density And The Ramp Queues, Pushkin Kachroo, Kaan Ozbay, Donald E. Grove

Electrical & Computer Engineering Faculty Research

This paper presents a feedback control design for isolated ramp metering control. This feedback control design, unlike the existing isolated feedback ramp controllers, also takes into account the ramp queue length. Using a nonlinear H∞ control design methodology, we formulate the problem in the desired setting to be able to utilize the results of the methodology.

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On-Road Remote Sensing Of Automobile Emissions In The Chicago Area: Year 4, Sajal S. Pokharel, Gary A. Bishop, Donald H. Stedman Jan 2001

On-Road Remote Sensing Of Automobile Emissions In The Chicago Area: Year 4, Sajal S. Pokharel, Gary A. Bishop, Donald H. Stedman

Fuel Efficiency Automobile Test Publications

No abstract provided.

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On-Road Remote Sensing Of Automobile Emissions In The Los Angeles Area: Year 2, Sajal S. Pokharel, Gary A. Bishop, Donald H. Stedman Jan 2001

On-Road Remote Sensing Of Automobile Emissions In The Los Angeles Area: Year 2, Sajal S. Pokharel, Gary A. Bishop, Donald H. Stedman

Fuel Efficiency Automobile Test Publications

No abstract provided.

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Fuel-Based On-Road Motor Vehicle Emissions Inventory For The Denver Metropolitan Area, Sajal S. Pokharel, Gary A. Bishop, Donald H. Stedman Jan 2001

Fuel-Based On-Road Motor Vehicle Emissions Inventory For The Denver Metropolitan Area, Sajal S. Pokharel, Gary A. Bishop, Donald H. Stedman

Fuel Efficiency Automobile Test Publications

No abstract provided.

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Fuel-Based On-Road Motor Vehicle Emissions Inventory For The Denver Metropolitan Area (Presentation), Sajal S. Pokharel, Gary A. Bishop, Donald H. Stedman Jan 2001

Fuel-Based On-Road Motor Vehicle Emissions Inventory For The Denver Metropolitan Area (Presentation), Sajal S. Pokharel, Gary A. Bishop, Donald H. Stedman

Fuel Efficiency Automobile Test Publications

No abstract provided.

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Learning Recursive Functions Refutably, Sanjay Jain, Efim Kinber, Rolf Wiehagen, Thomas Zeugmann Jan 2001

Learning Recursive Functions Refutably, Sanjay Jain, Efim Kinber, Rolf Wiehagen, Thomas Zeugmann

School of Computer Science & Engineering Faculty Publications

Learning of recursive functions refutably means that for every recursive function, the learning machine has either to learn this function or to refute it, i.e., to signal that it is not able to learn it. Three modi of making precise the notion of refuting are considered. We show that the corresponding types of learning refutably are of strictly increasing power, where already the most stringent of them turns out to be of remarkable topological and algorithmical richness. All these types are closed under union, though in different strengths. Also, these types are shown to be different with respect to their …

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Local And Systemic Controls On Fish And Fish Habitat In South Dakota Rivers And Streams: Implications For Management, Craig L. Milewski Jan 2001

Local And Systemic Controls On Fish And Fish Habitat In South Dakota Rivers And Streams: Implications For Management, Craig L. Milewski

Electronic Theses and Dissertations

Assessments of the health of rivers and streams in prairie environments would improve if the role of systemic patterns and processes among geologic-climatic settings in controlling physical habitat and fish communities were better defined. My research approach was based on a premise that assessments of the health of rivers and streams in prairie environments would benefit from studies that 1) examine the moderating effects of systemic patterns and processes by comparing physical habitat continua and fish communities among geologic-climatic settings, 2) determine the relative influence of locally interacting variables (e .g., channel shape and riparian vegetation) and systemic processes in …

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Verification Of A Distortion In The Microstructure Of Gan Detected By Exafs Using Ab Initio Density Functional Theory Calculations, N. Dimakis, Grant Bunker, M. Katsikini, E. C. Paloura Jan 2001

Verification Of A Distortion In The Microstructure Of Gan Detected By Exafs Using Ab Initio Density Functional Theory Calculations, N. Dimakis, Grant Bunker, M. Katsikini, E. C. Paloura

Physics and Astronomy Faculty Publications and Presentations

X-ray absorption fine structure (XAFS) measurements on a series of epitaxially grown GaN samples have shown a distortion in the microstructure of GaN. More specifically the central N atom is 4-fold coordinated but the four Ga atoms are not equidistant. It has been shown that 2.9 to 3.5 of them (depending on the growth conditions) are found in the expected from XRD distance of 1.94 A and the remaining are at a distance longer by approximately 15%. Second derivative calculation of the conformation energy using the Density Functional Theory (DFT) is used to investigate if the symmetric GaN cluster as …

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Probing The Strong Boundary Shape Dependence Of The Casimir Force, Thorsten Emig, Andreas Hanke, Ramin Golestanian, Mehran Kardar Jan 2001

Probing The Strong Boundary Shape Dependence Of The Casimir Force, Thorsten Emig, Andreas Hanke, Ramin Golestanian, Mehran Kardar

Physics and Astronomy Faculty Publications and Presentations

We study the geometry dependence of the Casimir energy for deformed metal plates by a path integral quantization of the electromagnetic field. For the first time, we give a complete analytical result for the deformation induced change in Casimir energy δE in an experimentally testable, nontrivial geometry, consisting of a flat and a corrugated plate. Our results show an interesting crossover for δE as a function of the ratio of the mean plate distance H, to the corrugation length λ: For λ≪H we find a slower decay ∼H−4, compared to the H−5 behavior predicted by the commonly used pairwise summation …

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Polymer Depletion Interaction Between Two Parallel Repulsive Walls, F. Schlesener, Andreas Hanke, R. Kimpel, S. Dietrich Jan 2001

Polymer Depletion Interaction Between Two Parallel Repulsive Walls, F. Schlesener, Andreas Hanke, R. Kimpel, S. Dietrich

Physics and Astronomy Faculty Publications and Presentations

The depletion interaction between two parallel repulsive walls confining a dilute solution of long and flexible polymer chains is studied by field-theoretic methods. Special attention is paid to self-avoidance between chain monomers relevant for polymers in a good solvent. Our direct approach avoids the mapping of the actual polymer chains on effective hard or soft spheres. We compare our results with recent Monte Carlo simulations [A. Milchev and K. Binder, Eur. Phys. J. B 3, 477 (1998)] and with experimental results for the depletion interaction between a spherical colloidal particle and a planar wall in a dilute solution of nonionic …

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Proceedings Of The First International Conference On Neutrosophy, Neutrosophic Logic, Neutrosophic Set, Neutrosophic Probability And Statistics, Florentin Smarandache Jan 2001

Proceedings Of The First International Conference On Neutrosophy, Neutrosophic Logic, Neutrosophic Set, Neutrosophic Probability And Statistics, Florentin Smarandache

Branch Mathematics and Statistics Faculty and Staff Publications

In 1960s Abraham Robinson has developed the non-standard analysis, a formalization of analysis and a branch of mathematical logic, that rigorously defines the infinitesimals. Informally, an infinitesimal is an infinitely small number. Formally, x is said to be infinitesimal if and only if for all positive integers n one has xxx < 1/n. Let &>0 be a such infinitesimal number. The hyper-real number set is an extension of the real number set, which includes classes of infinite numbers and classes of infinitesimal numbers. Let’s consider the non-standard finite numbers 1+ = 1+&, where “1” is its standard part and “&” its non-standard part, …

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Adaptive Web Sites By Web Usage Mining, Mario Rodney Creado Jan 2001

Adaptive Web Sites By Web Usage Mining, Mario Rodney Creado

Masters Theses

The World Wide Web has become a very popular marketing medium during the recent years. Many businesses use it extensively to publicize their products. Initially it began with static web sites. However as web sites got bigger and better, their maintenance became problematic. Just as business strategies change, so also will the orgainization of their web sites change. Hence the need of the hour is an adaptive web site (i.e. a web site that can organize itself based upon its usage). For this purpose, web usage mining techniques are used. The characteristics of the user's activity on the web site …

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Constraining The Crystallization And Post-Crystallization History Of The Wallamatogus Pluton, Maine, Using Compositional Data From Garnet, Biotite And Muscovite, Joy Kathleen Drake Jan 2001

Constraining The Crystallization And Post-Crystallization History Of The Wallamatogus Pluton, Maine, Using Compositional Data From Garnet, Biotite And Muscovite, Joy Kathleen Drake

Masters Theses

"The Wallamatogus Pluton, Maine, exhibits systematic variation in grain size, mineralogy, and phenocryst abundance (alkali-feldspar) from the margin to the center of the pluton. Three facies are recognized: 1) outermost, seriate, coarse-grained (Owe), 2) porphyritic medium- to fine-grained (Dwp ), 3) innermost, fine-grained equigranular (Dwf). These facies are concentrically arranged and their contacts are gradational. Muscovite and biotite occur in all facies; the outer two facies contain garnet, and tourmaline. Muscovite and biotite grains within micaceous enclaves compositionally overlap primary muscovite, suggesting that they are early-crystallized accumulations. Muscovite in multiphase clusters and secondary muscovite compositionally overlap, suggesting formation during post-crystallization …

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Population Characteristics And Sampling Methods Of Catfish For The James And Big Sioux Rivers, John E. Aterburn Jan 2001

Population Characteristics And Sampling Methods Of Catfish For The James And Big Sioux Rivers, John E. Aterburn

Electronic Theses and Dissertations

Concerns about the sustainability of catfish populations that produce large fish have increased because of abundant media images of large catfish and improvements in specialized fishing equipment. This study will help biologists address these concerns by providing important information about the channel catfish lctalurus punctarus and flathead catfish Pylodictis olivaris populations of the James and Big Sioux rivers and by assessing the effectiveness of various gears used to sample catfish. I compared the number of channel catfish and flathead catfish caught on trotlines by riverine habitat type, hook type, and bait type along with electrofishing and different hoop net combinations. …

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Utility Of Walleyes And Saugeyes As Secondary Predators In Small South Dakota Impoundments, Mark J. Ermer Jan 2001

Utility Of Walleyes And Saugeyes As Secondary Predators In Small South Dakota Impoundments, Mark J. Ermer

Electronic Theses and Dissertations

Walleye Stizostedion vitreum and saugeye (walleye x sauger S. canadense) fingerlings were concurrently stocked at equal densities into five small impoundments in 1997, 1988, and 1999 to evaluate relative survival, growth and their ability to restructure existing panfish communities. Prior to stocking, fish were differentially marked on the right or left side with freeze brands or with 700 ppm oxytetracycline hydrochloride (OTC) to allow accurate identification of each fish as a walleye (fry mark) or a saugeye (fingerling mark). Spring and fall night electrofishing was used to sample the stocked percids, as well as potential competing species such as largemouth …

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Measures Of Denitrification In Selected South Dakota Semi-Permanent Prairie Pothole Wetlands, Beverly S. Klein Jan 2001

Measures Of Denitrification In Selected South Dakota Semi-Permanent Prairie Pothole Wetlands, Beverly S. Klein

Electronic Theses and Dissertations

Wetlands are an integral part of agricultural systems in the prairie pothole regions of the North Central United States and Canadian Provinces. Little research has been done on denitrification in prairie potholes, and a better understanding of their denitrifying capability could aide in optimizing management practices near pothole areas. Most probable number (MPN) and denitrifying enzyme activity (DEA or Phase I) assays were conducted. Most probable number (MPN) measures were used to give an estimate of dissimilatory nitrate reduction to ammonia (DNRA) and denitrifying populations present in the wetlands. This study involved 3 selected semi-permanent prairie pothole wetlands near Madison, …

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Invertebrate Egg And Plant Seed Banks In Natural, Restored, And Drained Wetlands In The Prairie Pothole Region (Usa) And Potential Effects Of Sedimentation On Recolonization Of Hydrophytes And Aquatic Invertebrates, Robert Andrew Gleason Jan 2001

Invertebrate Egg And Plant Seed Banks In Natural, Restored, And Drained Wetlands In The Prairie Pothole Region (Usa) And Potential Effects Of Sedimentation On Recolonization Of Hydrophytes And Aquatic Invertebrates, Robert Andrew Gleason

Electronic Theses and Dissertations

Sediment is the major pollutant of wetlands, lakes, rivers, and estuaries in the United States and it poses unique threats to wetlands of the Prairie Pothole Region (PPR). Sediment may impact the success of wetland restorations because burial of invertebrate and plant propagules may impact hatching and germination success, and hence, may hamper successional changes throughout interannual climate cycles. Sedimentation also reduces the pool depth and volume, further exacerbating the recovery of hydrophyte communities in restored wetlands. I evaluated the potential impacts of sedimentation on prairie wetlands from several perspectives. First, I evaluated the effects of sedimentation on loss of …

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Wholes And Parts In General Systems Methodology, Martin Zwick Jan 2001

Wholes And Parts In General Systems Methodology, Martin Zwick

Systems Science Faculty Publications and Presentations

Reconstructability analysis (RA) decomposes wholes, namely data in the form either of set-theoretic relations or multivariate probability distributions, into parts, namely relations or distributions involving subsets of variables. Data is modeled and compressed by variablebased decomposition, by more general state-based decomposition, or by the use of latent variables. Models, which specify the interdependencies among the variables, are selected to minimize error and complexity.

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Phenomenology Of The Su(2)(L) X Su(2)(I) X U(1)(Y) X U(1)(Y') Model, Shuquan Nie Jan 2001

Phenomenology Of The Su(2)(L) X Su(2)(I) X U(1)(Y) X U(1)(Y') Model, Shuquan Nie

Dissertations, Theses, and Masters Projects

We consider the effective low-energy SU(2) L x SU(2)I x U(1)Y x U(1)Y' model, which is based on the E6 grand unification theory. SU(2)I is a subgroup of SU(3) R and commutes with the electric charge operator.;Higgs bosons in the Standard Model and two-Higgs doublet models are reviewed and studied first. The flavor-changing neutral currents and their effects on the anomalous magnetic moment of the muon are discussed. Bounds on masses of Higgs bosons are obtained by requiring that the vacuum is stable and perturbation theory is valid up to a large scale. We introduce Higgs multiplets including two neutral …

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Sub-Pixel Techniques To Improve Spatial Resolution, Mark Robert Idema Jan 2001

Sub-Pixel Techniques To Improve Spatial Resolution, Mark Robert Idema

Dissertations, Theses, and Masters Projects

Image acquisition using a scene sampling device generally results in a loss of fidelity in the acquired image, particularly if the scene contains high frequency features. Acquired images are also degraded by the blurring effects of acquisition filtering, image reconstruction, and additive noise effects. to compensate for these degradations, a digital restoration filter that attempts to partially eliminate the blurring while avoiding amplification of the noise effects is needed. In addition, to compensate for undersampling, a subpixel technique known as microscanning is required. This dissertation provides research into the spatial resolution enhancement of digital images based on subpixel techniques that …

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Preparation And Characterization Of Molecular Imprinting Polymer With (S)-Naproxen, Yue Hu Jan 2001

Preparation And Characterization Of Molecular Imprinting Polymer With (S)-Naproxen, Yue Hu

Dissertations, Theses, and Masters Projects

No abstract provided.

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Heat Shock Protein (Hsp70) Response In The Eastern Oyster, Crassostrea Virginica, Exposed To Various Contaminants (Pahs, Pcbs And Cadmium), Luis A. Cruz Rodriguez Jan 2001

Heat Shock Protein (Hsp70) Response In The Eastern Oyster, Crassostrea Virginica, Exposed To Various Contaminants (Pahs, Pcbs And Cadmium), Luis A. Cruz Rodriguez

Dissertations, Theses, and Masters Projects

The stress protein response has been proposed as a general indicator of exposure to stress as their expression might integrate overall biological impact and interactions among multiple stressors. as a marker of contaminant effects, a major advantage is the premise of higher sensitivity over other indices such as condition index, scope for growth and survival. Laboratory exposure to suspended field contaminated sediments (SFCS) elicited a stress protein response (HSP70) in the eastern oyster, ( Crassostrea virginica). The stress response probably resulted from the combined effect of various contaminants including PAHs, metals and PCBs. Exposure to 1--2g suspended clay particles spiked …

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Application Of The Genetic Algorithm To An Ecological Simulation, William J. Seufzer Jan 2001

Application Of The Genetic Algorithm To An Ecological Simulation, William J. Seufzer

Dissertations, Theses, and Masters Projects

A computational framework is built and demonstrated which is capable of testing plant growth strategies. The framework consists of Vgrass, a carbon based simulation model of a single Zostera marina plant, and the genetic algorithm (GA). Vgrass is based on published seagrass models, published photosynthetic data, and general plant physiology information. The model grows individual leaves whose initiation times are based on degree-day intervals. Leaf size is computed and combined with shoot density to compute population self shading. Leaf length is an emergent property since leaf growth is limited by light attenuation caused by self shading. The model is able …

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Vitellogenin -- A Biomarker Of Exposure To Environmental Estrogens For Mummichog (Fundulus Heteroclitus) From A Creosote-Contaminated Site?, Sara Mirabilio Jan 2001

Vitellogenin -- A Biomarker Of Exposure To Environmental Estrogens For Mummichog (Fundulus Heteroclitus) From A Creosote-Contaminated Site?, Sara Mirabilio

Dissertations, Theses, and Masters Projects

Vitellogenin (VTG) is widely used as a biomarker for environmental estrogens and reproductive disruption in fish. Vitellogenesis is the process by which yolk is formed. The endpoint is most sensitive in male fish where vitellogenesis is an abnormal process. Research examining effects of environmental mixtures of chemicals (e.g. creosote) on vitellogenesis is limited. This study examines plasma VTG expression in both male and female mummichog, Fundulus heteroclitus, collected from a creosote-contaminated site and two reference sites in lower Chesapeake Bay, USA, and in wild-caught male reference fish exposed in the laboratory to creosote-contaminated sediment. Further, this study uses tissue somatic …

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Growth Patterns Of Three Species Of Catfish (Ictaluridae) From Three Virginia Tributaries Of The Chesapeake Bay, William J. Connelly Jan 2001

Growth Patterns Of Three Species Of Catfish (Ictaluridae) From Three Virginia Tributaries Of The Chesapeake Bay, William J. Connelly

Dissertations, Theses, and Masters Projects

No abstract provided.

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