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

Physical Sciences and Mathematics Commons

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

2002

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 781 - 810 of 3435

Full-Text Articles in Physical Sciences and Mathematics

Examination Of Small Mammal Diversity In The Riparian Areas Of Walden, Tennessee, Forrest Brown Vanderbilt Aug 2002

Examination Of Small Mammal Diversity In The Riparian Areas Of Walden, Tennessee, Forrest Brown Vanderbilt

Masters Theses and Doctoral Dissertations

Vanderbilt, Forrest B. Examination of Small Mammal Diversity in the Riparian Areas of Walden, Tennessee Thesis under the direction of Robert D. Keller, Ph.D., Assistant Professor of Biology It has been hypothesized that riparian zones are prime conservation habitats and can be used as indicators of general ecosystem health (Montgomery 1996). Riparian zones, comprising a range of habitat types, typically exhibit higher biotic diversity when compared to adjacent upland hardwood forests (Batzli 1977, Cross 1985a, Cross 1985b, Doyle 1985, Knopf et al. 1988, Doyle 1990, Naiman and Decamps 1997, Ellison and van Riper III 1998, Olson and Knopf 1998). Therefore …


Effects Of Roadway-Related Physical And Chemical Habitat Alterations On Stream Ecosystems, Thomas Stuart Woodcock Aug 2002

Effects Of Roadway-Related Physical And Chemical Habitat Alterations On Stream Ecosystems, Thomas Stuart Woodcock

Electronic Theses and Dissertations

Roadways are an important feature of both rural and urban landscapes, and disturbances associated with them have a variety of effects on stream ecosystems. Organisms may be differentially affected by toxic substances, depending on such factors as sediment and water chemistry, toxin bioavailability, uptake and elimination processes, and tolerance mechanisms. The effects of heavy metal pollution and habitat alteration related to urbanization and industry were examined along a gradient of impact in Goosefare Brook, a small stream in southern Maine with a history of water quality impahlent. The structure of invertebrate assemblages changed significantly along the gradient, and were related …


Late Holocene Sea-Level Change Around Newfoundland, Julia Daly Aug 2002

Late Holocene Sea-Level Change Around Newfoundland, Julia Daly

Electronic Theses and Dissertations

Analysis of basal salt-marsh peats and tide-gauge data from several locations around Newfoundland yield high-resolution late Holocene sea-level reconstructions and constrain differential sea-level change. The transition between rising and falling local sea levels and the influence of glacioisostasy on relative sea-level change around Newfoundland through the late Holocene are not well known fiom previous research. The patterns of local relative sea-level change during this time have important implications for constraining numerical models of sea-level change, and therefore inferences about ice sheet thickness and the response of the lithosphere to deglaciation. I investigated the stratigraphy of salt marshes at four locations …


Metal Abundances And Kinematics Of Bright Metal-Poor Giants Selected From The Lse Survey: Implications For The Metal-Weak Thick Disk, Timothy C. Beers, John S. Drilling, Silvia Rossi, Masashi Chiba, Jaehyon Rhee, Birgit Fṻhrmeister, John E. Norris, Ted Von Hippel Aug 2002

Metal Abundances And Kinematics Of Bright Metal-Poor Giants Selected From The Lse Survey: Implications For The Metal-Weak Thick Disk, Timothy C. Beers, John S. Drilling, Silvia Rossi, Masashi Chiba, Jaehyon Rhee, Birgit Fṻhrmeister, John E. Norris, Ted Von Hippel

Publications

We report medium-resolution (1–2A ˚ ) spectroscopy and broadband (UBV) photometry for a sample of 39 bright stars (the majority of which are likely to be giants) selected as metal-deficient candidates from an objective-prism survey concentrating on Galactic latitudes below |b| = 30, the Luminous Stars Extension (LSE) survey of Drilling & Bergeron. Although the primary purpose of the LSE survey was to select OB stars (hence the concentration on low latitudes), the small number of bright metal-deficient giant candidates noted during this survey provide interesting information on the metal-weak thick disk (MWTD) population. Metal abundance estimates are obtained from …


The Biophysical Basis Of Triplet Repeat Dna Expansion In Genetic Disease, Anthony M. Paiva Aug 2002

The Biophysical Basis Of Triplet Repeat Dna Expansion In Genetic Disease, Anthony M. Paiva

Seton Hall University Dissertations and Theses (ETDs)

.


Groundwater Study Of The Wandering Townsite, S Ghauri Aug 2002

Groundwater Study Of The Wandering Townsite, S Ghauri

Resource management technical reports

A groundwater study was carried out in the townsite of Wandering, Western Australia. This report describes the town and its catchment, the hydrogeological investigation characterising groundwater flow systems within the townsite, and recommends actions for managing salinity risk.


The 1.20 Å Resolution Crystal Structure Of The Aminopeptidase From Aeromonas Proteolytica Complexed With Tris: A Tale Of Buffer Inhibition, William Desmarais, David L. Bienvenue, Krzysztof P. Bzymek, Richard C. Holz, Gregory A. Petsko, Dagmar Ringe Aug 2002

The 1.20 Å Resolution Crystal Structure Of The Aminopeptidase From Aeromonas Proteolytica Complexed With Tris: A Tale Of Buffer Inhibition, William Desmarais, David L. Bienvenue, Krzysztof P. Bzymek, Richard C. Holz, Gregory A. Petsko, Dagmar Ringe

Chemistry Faculty Research and Publications

The aminopeptidase from Aeromonas proteolytica (AAP) is a bridged bimetallic enzyme that removes the N-terminal amino acid from a peptide chain. To fully understand the metal roles in the reaction pathway of AAP we have solved the 1.20 Å resolution crystal structure of native AAP (PDB ID = 1LOK). The high-quality electron density maps showed a single Tris molecule chelated to the active site Zn2+, alternate side chain conformations for some side chains, a sodium ion that mediates a crystal contact, a surface thiocyanate ion, and several potential hydrogen atoms. In addition, the high precision of the atomic …


Stabilization Of Rutile-Related Thin Film On Tio2 Substrates, Youngnam Cho Aug 2002

Stabilization Of Rutile-Related Thin Film On Tio2 Substrates, Youngnam Cho

Electronic Theses and Dissertations

Conducting metal oxide thin films are of broad interest because they have a wide variety of magnetic and electronic properties. Materials exist that range from superconducting to insulating, are ferromagnetic and are ferroelectric. These properties make thin conducting oxide films attractive for many industrial applications. A class of metal oxides exists that adapt the rutile crystal structure; the structure of the mineral rutile, TiO2. These metal oxides have the general formula MO2 where M is a metal cation of valence +4. Metal oxides crystallizing in the rutile structure also display a wide variety of physical properties. The …


Design And Analysis For Melt Casting Metallic Fuel Pins Incorporating Volatile Actinides, Xiaolong Wu Aug 2002

Design And Analysis For Melt Casting Metallic Fuel Pins Incorporating Volatile Actinides, Xiaolong Wu

UNLV Theses, Dissertations, Professional Papers, and Capstones

Fundamental issues related to the selection of a metallic fuel casting furnace design are presented and discussed including heating mechanisms, casting issues, crucible design, and issues related to the mass transport of americium. The process of evaluating all of these different criteria is undertaken to select a concept that would have the greatest chance of success for casting americium in a metallic fuel rod. Based on this evaluation process, a concept for the casting of metallic fuel pins containing high vapor pressure materials is selected and discussed. The important physics of this concept include mass transport of americium from the …


Hcl: A Specification Language For Hierarchical Text Classification, Aixin Sun, Ee Peng Lim, Wee-Keong Ng Aug 2002

Hcl: A Specification Language For Hierarchical Text Classification, Aixin Sun, Ee Peng Lim, Wee-Keong Ng

Research Collection School Of Computing and Information Systems

Hierarchical text classification refers to assigning text documents to the categories in a given category tree based on their content. With large number of categories organized as a tree, hierarchical text classification helps users to find information more quickly and accurately. Nevertheless, hierarchical text classification methods in the past have often been constructed in a proprietary manner. The construction steps often involve human efforts and are not completely automated. In this paper, we therefore propose a specification language known as HCL (Hierarchical Classification Language) . HCL is designed to describe a hierarchical classification method including the definition of a category …


Il-10 And Alveolar Bone Loss, Abdulaziz Saud Al-Rasheed Aug 2002

Il-10 And Alveolar Bone Loss, Abdulaziz Saud Al-Rasheed

Loma Linda University Electronic Theses, Dissertations & Projects

Interleukin-10 (IL-10) is a cytokine with anti-inflammatory activities. IL-10 knockout (KO) mice exhibit severe intestinal inflammation in the presence of normal gut flora. We hypothesized that IL-10 KO mice would also be susceptible to inflammatory periodontal disease resulting in alveolar bone loss (ABL). The purpose of this study was to compare naturally occurring ABL in IL-10 KO and wild type (WT) mice. Twelve IL-10 KO and 12 WT mice, age-(7 months) and sex-(male) matched, were used. Half of the mice were on 129/SvEv and half on C57BL/6J background. Animal heads were defleshed and treated to remove all organic material. ABL …


Studies Towards Anti-Bredt Ring Systems Of Natural Products, Ulf Peters Aug 2002

Studies Towards Anti-Bredt Ring Systems Of Natural Products, Ulf Peters

Masters Theses

Different ways for the synthesis of anti-Bredt ring systems of natural products have been explored.

An intended Favorskii rearrangement-divinylcyclopropane rearrangement to lead to the bicyclo[4.3.1] decadiene ring system was not accomplished. An envisioned tandem cyclopropanation-divinycyclopropane rearrangement of 2,3-divinyhex-2-enol did not furnish the desired bicyclo[4.4.1]undecadiene system, either, because cyclopropane occurred on the exocyclic double bond.

In the course of cyclopropanation studies on various cyclohexenols, an α-silyl-α-diazoethyl acetate was employed as tether. It could be removed by protodesilylation or oxidative cleavage to give a 1-(carboxylic ester)-cyclopropane or a 1-(carboxylic easter)-1-hydroxy cyclopropane derivative, respectively. Cyclopropanation general occurred on the less substituted more …


Single-Molecule Imaging With A Custom-Built Fluorescence Microscope, David Allan Ball Aug 2002

Single-Molecule Imaging With A Custom-Built Fluorescence Microscope, David Allan Ball

Masters Theses

An apparatus for single-molecule imaging was constructed and used to examine nanomolar solutions of Bodipy Texas Red in water. The illumination source for this microscope is a synchronously pumped dye laser operating at a wavelength of 585 nm. The beam can easily be switched to give total internal reflection or wide field epi-illumination excitation of the sample. The instrument also has the capability of being used for single-molecule detection by confocal epiillumination and for fluorescence correlation spectroscopy. Movies of single molecules were analyzed using custom software written in Matlab. Molecules stuck to the surface revealed fluctuations in intensity, or blinking, …


Clinically Relevant Aspects Of Chronic Pain: Normal Personality Predictors, Stephen Ray Nitch Aug 2002

Clinically Relevant Aspects Of Chronic Pain: Normal Personality Predictors, Stephen Ray Nitch

Loma Linda University Electronic Theses, Dissertations & Projects

This study examined the normal personality characteristics of chronic pain patients using cluster analysis. To date, much of the research involving chronic pain and personality has assumed that signs of psychopathology are likely to be present (Jay, Grove, and Grove, 1987; Love and Peck, 1987). There have been some exceptions to this trend by researchers who sought to measure the normal personality structure of individuals with chronic pain (see Wade, Dougherty, Hart, and Cook, 1992). One of central aims of the current study was to further refine the psychosocial taxonomy of chronic pain patients by paying more attention to individual …


Weir River Area Of Critical Environmental Concern: Natural Resources Inventory, Urban Harbors Institute, University Of Massachusetts Boston Aug 2002

Weir River Area Of Critical Environmental Concern: Natural Resources Inventory, Urban Harbors Institute, University Of Massachusetts Boston

Urban Harbors Institute Publications

The Weir River Area of Critical Environmental Concern (ACEC) was designated by the Massachusetts Secretary of Environmental Affairs in 1986 in recognition of one of the largest and most productive salt marsh ecosystems in the Boston Harbor area. As an ACEC, the region is afforded additional attention and protection from state agencies in order to achieve the goals of designation--to restore, enhance, and manage the resources. The region was nominated by residents of the abutting communities of Hull, Hingham, and Cohasset who took the opportunity to call attention to the uniqueness of the environment and to their concerns that development …


A Formal Method To Analyze Framework-Based Software, Trent N. Larson Aug 2002

A Formal Method To Analyze Framework-Based Software, Trent N. Larson

Theses and Dissertations

Software systems are frequently designed using abstractions that make software verification tractable. Specifically, by choosing meaningful, formal abstractions for interfaces and then designing according to those interfaces, one can verify entire systems according to behavioral predicates. While impractical for systems in general, framework-based software architectures are a type of system for which formal analysis can be beneficial and practical over the life of the system. We present a method to formally analyze behavioral properties of framework-based software with higher-order logic and then demonstrate its utility for a significant, modern system.


Separable Preference Orders, Jonathan K. Hodge Aug 2002

Separable Preference Orders, Jonathan K. Hodge

Dissertations

Whenever a decision-maker must express simultaneously his or her preferences on several possibly related issues, the existence of interdependence among these preferences can lead to collective decisions that are unsatisfactory or even paradoxical. Intuitively, an individual’s preferences are said to be separable on a subset of issues if they do not depend on the choice of alternatives for issues outside the subset. Here we explore from a mathematical standpoint the properties of separable and nonseparable preference orders. We begin by formulating a general model of multidimensional preferences and we formally introduce the notions of separability and noninfluentiality. We study the …


Organizing And Personalizing Intelligence Gathering From The Web, Hwee-Leng Ong, Ah-Hwee Tan, Jamie Ng, Pan Hong, Qiu-Xiang Li Aug 2002

Organizing And Personalizing Intelligence Gathering From The Web, Hwee-Leng Ong, Ah-Hwee Tan, Jamie Ng, Pan Hong, Qiu-Xiang Li

Research Collection School Of Computing and Information Systems

In this paper, we describe how an integrated web‐based application, code‐named FOCI (Flexible Organizer for Competitive Intelligence), can help the knowledge worker in the gathering, organizing, tracking and dissemination of competitive intelligence (CI). It combines the use of a novel user‐configurable clustering, trend analysis and visualization techniques to manage information gathered from the web. FOCI allows its users to define and personalize the organization of the information clusters according to their needs and preferences into portfolios. These personalized portfolios created are saved and can be subsequently tracked and shared with other users. The paper runs through an example to show …


Suspended Alexandrium Spp. Hypnozygote Cysts In The Gulf Of Maine, Sarah L. Kirn Aug 2002

Suspended Alexandrium Spp. Hypnozygote Cysts In The Gulf Of Maine, Sarah L. Kirn

Electronic Theses and Dissertations

Hypnozygote cysts are a known stage in the life cycle of Alexandrium spp. Negatively buoyant cysts purportedly fall ,to the benthos where they undergo mandatory quiescence until their endogenous clock makes germination possible. If oxygen is present and the endogenous clock allows, germination will occur at a rate proportional to light and temperature. Offshore in the Gulf of Maine, where Alexandrium blooms are well documented, the paradigm of benthic cysts is problematic. Sediment surveys have found wide distribution of cysts, with highest cyst concentrations below 100 m in areas where deposition is favored. Germination at these depths is likely slow …


Simulation Of Structure, Dynamics And Electron Diffraction Patterns Of Heterogeneous Clusters Armn2N, W. H. Jinasena Aug 2002

Simulation Of Structure, Dynamics And Electron Diffraction Patterns Of Heterogeneous Clusters Armn2N, W. H. Jinasena

Electronic Theses and Dissertations

The nitrogen-argon system provides a useful paradigm for studying segregation and mixing behavior in heterogeneous clusters. Using three realistic pair potentials corresponding to argon-argon, nitrogen-nitrogen and argon-nitrogen interactions, the structures and thermodynamics of Arm(N2)n, clusters are investigated. Comparison of these results to previous simulation results on neat argon and nitrogen clusters is made. The initial focus of the study is the series of thirteen particle clusters of Arm(N2)13-m (0 ≤ m ≤ 13); molecular dynamics in the microcanonical ensemble is the principle simulation tool. The icosahedral nitrogen-argon clusters …


Arsenic In Drinking Water And Public Opinion On Wildlife Management As Case Studies Illustrating Natural Resource Policy, Jessica Sargent-Michaud Aug 2002

Arsenic In Drinking Water And Public Opinion On Wildlife Management As Case Studies Illustrating Natural Resource Policy, Jessica Sargent-Michaud

Electronic Theses and Dissertations

There are various ways to approach policy planning. This thesis consists of two Maine natural resource issue case studies illustrating different approaches to policy analysis. The first, a case study of arsenic contamination, is an example of a study that assembles information and provides that information to the public to influence public behavior. The second, a case study of wildlife management, is an example of a study that surveys the public to collect information on the public's opinions and attitudes to influence agency behavior towards the public. Arsenic in drinking water in Maine is a public health concern. There may …


Relationships Between Stream Geomorphology And Fish Community Structure And Diversity In Maine, Emily Gaenzle Aug 2002

Relationships Between Stream Geomorphology And Fish Community Structure And Diversity In Maine, Emily Gaenzle

Electronic Theses and Dissertations

Predicting patterns in species distribution and abundance for resource management and conservation is a major focus of applied ecology. The primary objective of this study was to determine if there is a predictable relationship between stream geomorphology and fish community structure, native species richness, and native salmonid abundance in Maine. Specifically, I examined relationships between fish assemblages and geomorphic stream types, as delineated by the Rosgen classification system (Rosgen 1996). Fifty-three stream reaches in Maine were classified, and fish communities within the reaches were characterized using backpack electrofishing. Species richness was lowest in A-type streams (i.e., steep, entrenched, confined), which …


The Enthalpy Of Vaporization And Sublimation Of Corannulene, Coronene, And Perylene At T = 298.15 K, James S. Chickos, Paul Webb, Gary Nichols, Tetsu Kiyobayashi, Pei-Chao Cheng, Lawrence Scott Jul 2002

The Enthalpy Of Vaporization And Sublimation Of Corannulene, Coronene, And Perylene At T = 298.15 K, James S. Chickos, Paul Webb, Gary Nichols, Tetsu Kiyobayashi, Pei-Chao Cheng, Lawrence Scott

James Chickos

No abstract provided.


Determination Of Barbituric Acid, Utilizing A Rapid And Simple Colorimetric Assay, Ronald Bartzatt Jul 2002

Determination Of Barbituric Acid, Utilizing A Rapid And Simple Colorimetric Assay, Ronald Bartzatt

Chemistry Faculty Publications

Barbituric acid is widely used in the manufacturing of plastics, textiles, polymers, and pharmaceuticals. Three assay methods are presented, which can utilize either aqueous or solid samples. The detection of as little as 10 μg of barbituric acid can be accomplished, either as an aqueous or solid sample, when using micro reaction tubes. The red–violet endpoint is easily discerned and results upon the formation of a violuric acid derivative. A Spot Test protocol is described which allows for a positive/negative indication of barbituric acid presence. The Spot Test is sensitive to as little as 18.75 μg/ml of barbituric acid. The …


Developing A Sensing System For The Measurement Of Oxygen Concentration In Liquid Pb-Bi Eutectic: Quarterly Progress Report (May 01 – July 31, 2002), Yingtao Jiang, Bingmei Fu, Woosoon Yim Jul 2002

Developing A Sensing System For The Measurement Of Oxygen Concentration In Liquid Pb-Bi Eutectic: Quarterly Progress Report (May 01 – July 31, 2002), Yingtao Jiang, Bingmei Fu, Woosoon Yim

Transmutation Sciences Materials (TRP)

Accurate measurement of the oxygen concentration in liquid Lead-Bismuth Eutectic (LBE) cooling system is critical in the active control of the corrosion at the interface between LBE and the stainless steel of transport tubes. Currently, LANL (Los Alamos National Laboratory) scientists have employed an automobile-style YSZ (Yttria Stabilized Zirconia) oxygen sensor unit to measure oxygen levels in an engineeringscaled LBE test system. Although the theoretical model for calculating oxygen concentration based on voltage measurement of YSZ sensor in static conditions is well understood, there is an urgent and strong need to obtain a complete set of calibration curves for YSZ …


Use Of Sensory Cues By Fish Crows Corvus Ossifragus Preying On Artificial Bird Nests, Leonard Santisteban, Kathryn E. Sieving, Michael L. Avery Jul 2002

Use Of Sensory Cues By Fish Crows Corvus Ossifragus Preying On Artificial Bird Nests, Leonard Santisteban, Kathryn E. Sieving, Michael L. Avery

United States Department of Agriculture Wildlife Services: Staff Publications

How predators locate avian nests is poorly understood and has been subjected to little experimental inquiry. We examined which sensory stimuli were important in the nest-finding behavior of fish crowsCorvus ossifragus, a common nest predator in the southeastern United States. Using an array of potted trees in a large enclosure, we presented artificial nests to captive crows and quantified responses to visual, auditory, and olfactory nest cues, and nest position. Partial ranks of nest-treatment preferences were analyzed using log-linear models. Nest visibility significantly increased the likelihood of predation by fish crows and increasing nest height was a marginally significant influence …


Field Trip Guide (For The Nebraska Well Drillers Association) Southwestern Nebraska Geology, Duane Eversoll, Jim Goeke Jul 2002

Field Trip Guide (For The Nebraska Well Drillers Association) Southwestern Nebraska Geology, Duane Eversoll, Jim Goeke

Conservation and Survey Division

No abstract provided.


Context Building Information-Centric Decision-Support Systems, Steven J. Gollery, Jens G. Pohl Jul 2002

Context Building Information-Centric Decision-Support Systems, Steven J. Gollery, Jens G. Pohl

Collaborative Agent Design (CAD) Research Center

As the volume of data and human-centered information available to decision-makers continues to increase at an ever-accelerating rate, the need to represent information in software-processable formats becomes more apparent. At the same time, the availability of information from diverse sources through the World Wide Web provides the opportunity to widen the scope of input to decision-support systems, if this information can be made accessible through automated means. Past approaches to information-centric interoperability have been based on the use of a shared static object model, but this becomes impractical when we consider the loosely-coupled decentralized nature of the Web.

This paper …


Some Thoughts On Human Nature: A Discussion Of Human Strenghts And Weaknesses, Jens G. Pohl Jul 2002

Some Thoughts On Human Nature: A Discussion Of Human Strenghts And Weaknesses, Jens G. Pohl

Collaborative Agent Design (CAD) Research Center

This paper attempts to explore the behavioral characteristics of human beings from a point of view that is not based on inter-human comparisons, but on an examination of the intrinsic physical, biological, intellectual, emotional, and social characteristics of this species. It is argued that the experience-based nature of the human cognitive system greatly reduces our ability to adapt to changes in our environment, exploit opportunities, and create new knowledge. A fundamental biological survival instinct drives the human being to seek a level of certainty and security that is irreconcilable with a continuously changing and largely unpredictable environment. The symptoms of …


The Underlying Design Principles Of The Icdm Development Toolkit, Kym J. Pohl, Jens G. Pohl Jul 2002

The Underlying Design Principles Of The Icdm Development Toolkit, Kym J. Pohl, Jens G. Pohl

Collaborative Agent Design (CAD) Research Center

For the past sixteen years the Collaborative Agent Design Research Center (CADRC) at the California Polytechnic State University (Cal Poly), San Luis Obispo has pursued the design and development of agent-based decision-support systems. Throughout this journey the CADRC has relied on a suite of development tools that greatly assist in the creation and management of such systems. This suite of tools is known as the Integrated Cooperative Decision-Making (ICDM) software development toolkit.

Not only does ICDM function as an accelerator (i.e., rapid development) and stabilizer (i.e., built-in robustness and fault tolerance) in the development of decision-support systems, but it also …