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2005

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Articles 3061 - 3090 of 5573

Full-Text Articles in Physical Sciences and Mathematics

Basic Region Of Residues 228-231 Of Protein Kinase Ck1Α Is Involved In Its Interaction With Axin: Binding To Axin Does Not Affect The Kinase Activity, Pablo Sobrado, Ana Jedlicki, Victor H. Bustos, Catherine C. Allende, Jorge E. Allende Feb 2005

Basic Region Of Residues 228-231 Of Protein Kinase Ck1Α Is Involved In Its Interaction With Axin: Binding To Axin Does Not Affect The Kinase Activity, Pablo Sobrado, Ana Jedlicki, Victor H. Bustos, Catherine C. Allende, Jorge E. Allende

Chemistry Faculty Research & Creative Works

Protein kinase CK1, also known as casein kinase 1, participates in the phosphorylation of β-catenin, which regulates the functioning of the Wnt signaling cascade involved in embryogenesis and carcinogenesis. β-catenin phosphorylation occurs in a multiprotein complex assembled on the scaffold protein axin. The interaction of CK1α from Dani rerio with mouse-axin has been studied using a pull-down assay that uses fragments of axin fused to glutathione S transferase, which is bound to glutathione sepharose beads. The results indicate that the three lysines present in the basic region of residues 228-231 of CK1α are necessary for the binding of CK1 to …


Innovative Solutions To Human–Wildlife Conflicts Feb 2005

Innovative Solutions To Human–Wildlife Conflicts

United States Department of Agriculture Wildlife Services: Staff Publications

The mission of the U.S. Department of Agriculture’s (USDA) Wildlife Services (WS) Program is to provide Federal leadership in managing problems caused by wildlife. The National Wildlife Research Center (NWRC) functions as the research arm of WS by providing scientific information on the development of socially acceptable methods for wildlife damage management. As part of WS’ strategic plan to improve the coexistence of people and wildlife, NWRC has identified four strategic program goals: (1) developing methods, (2) providing wildlife services, (3) valuing and investing in people, and (4) enhancing information and communication. WS is dedicated to helping meet the wildlife …


Research Strategies Of The National Wildlife Research Center To Control Bovine Tuberculosis In Wildlife In Michigan, Usa, A. R. Berentsen, M. R. Dunbar, R. G. Mclean Feb 2005

Research Strategies Of The National Wildlife Research Center To Control Bovine Tuberculosis In Wildlife In Michigan, Usa, A. R. Berentsen, M. R. Dunbar, R. G. Mclean

United States Department of Agriculture Wildlife Services: Staff Publications

Bovine tuberculosis (bTB) is a zoonotic disease caused by Mycobaterium bovis and is transmissible to humans, wildlife, and domestic livestock. In the United Kingdom, the suspected wildlife reservoir of bTB is the badger (Meles meles) (HUTCHINGS and HARRIS, 1 997), and in New Zealand, the culprit is the brush-tailed possum (Trichosurus vulpecula) (MORRIS et al., 1994). In northern Michigan, USA, bovine tuberculosis is endemic in white-tailed deer (Odocoileus virginianus). In 1975 a hunter-killed white-tailed deer in Alpena County, Michigan, USA, was tested positive for bTB. Subsequent surveillance by the Michigan Department of Natural Resources …


Shape Invariance In Supersymmetric Quantum Mechanics And Its Application To Selected Special Functions Of Modern Physics, Chad Husko, Brenton Knuffman, Asim Gangopadhyaya, Jeffrey Mallow Feb 2005

Shape Invariance In Supersymmetric Quantum Mechanics And Its Application To Selected Special Functions Of Modern Physics, Chad Husko, Brenton Knuffman, Asim Gangopadhyaya, Jeffrey Mallow

Physics: Faculty Publications and Other Works

We applied the methods of supersymmetric quantum mechanics to differential equations that generate well-known special functions of modern physics. This application provides new insight into these functions and generates recursion relations among them. Some of these recursion relations are apparently new (or forgotten), as they are not available in commonly used texts and handbooks. This method can be easily extended to explore other special functions of modern physics.


Art Of The Astrolabe, Heather Suzanne Campbell Feb 2005

Art Of The Astrolabe, Heather Suzanne Campbell

Archived Theses and Dissertations

The astrolabe is a well known scientific instrument, commonly found in Islamic art collections. Despite its placement in art museums, it does not receive the same examination or discussion as other metalwork. This leads to errors in dating and place of origin when an instrument that lacks a dedication inscription or a signature.

This study places the astrolabe in an art historical context and not a scientific one.

Much literature has been written on this instrument concentrating on the scientific nature of the instrument or as part of a collection of scientific instruments. Its history, function, place in society and …


Reconstruction Of An Unknown Boundary Portion From Cauchy Data In N- Dimensions, Kurt Bryan, Lester Caudill Feb 2005

Reconstruction Of An Unknown Boundary Portion From Cauchy Data In N- Dimensions, Kurt Bryan, Lester Caudill

Department of Math & Statistics Faculty Publications

We consider the inverse problem of determining the shape of some inaccessible portion of the boundary of a region in n dimensions from Cauchy data for the heat equation on an accessible portion of the boundary. The inverse problem is quite ill-posed, and nonlinear. We develop a Newton-like algorithm for solving the problem, with a simple and efficient means for computing the required derivatives, develop methods for regularizing the process, and provide computational examples.


Muon Transfer From Muonic Hydrogen To Atomic Oxygen And Nitrogen, Anh-Thu Le, C. D. Lin Feb 2005

Muon Transfer From Muonic Hydrogen To Atomic Oxygen And Nitrogen, Anh-Thu Le, C. D. Lin

Physics Faculty Research & Creative Works

The results of diabatic hyperspherical close-coupling calculations are presented for the charge exchange of a negative muon from muonic hydrogen to oxygen and nitrogen for collision energies from 10-3 to 103 eV. It is shown that converged results can be obtained using a much smaller number of channels than in the traditional adiabatic approach. For the energy range below 10 eV our results for nitrogen are in good agreements with the available experimental data and the recent calculations within hyperspherical elliptic coordinates. However, discrepancies were found in the case of oxygen, where a p -wave shape resonance is …


Video Summarization And Scene Detection By Graph Modeling, Chong-Wah Ngo, Yu-Fei Ma, Hong-Jiang Zhang Feb 2005

Video Summarization And Scene Detection By Graph Modeling, Chong-Wah Ngo, Yu-Fei Ma, Hong-Jiang Zhang

Research Collection School Of Computing and Information Systems

In this paper, we propose a unified approach for video summarization based on the analysis of video structures and video highlights. Two major components in our approach are scene modeling and highlight detection. Scene modeling is achieved by normalized cut algorithm and temporal graph analysis, while highlight detection is accomplished by motion attention modeling. In our proposed approach, a video is represented as a complete undirected graph and the normalized cut algorithm is carried out to globally and optimally partition the graph into video clusters. The resulting clusters form a directed temporal graph and a shortest path algorithm is proposed …


Fast And Robust Incremental Action Prediction For Interactive Agents, Jonathan Dinerstein, Parris K. Egbert, Dan A. Ventura Feb 2005

Fast And Robust Incremental Action Prediction For Interactive Agents, Jonathan Dinerstein, Parris K. Egbert, Dan A. Ventura

Faculty Publications

The ability for a given agent to adapt on-line to better interact with another agent is a difficult and important problem. This problem becomes even more difficult when the agent to interact with is a human, since humans learn quickly and behave non-deterministically. In this paper we present a novel method whereby an agent can incrementally learn to predict the actions of another agent (even a human), and thereby can learn to better interact with that agent. We take a case-based approach, where the behavior of the other agent is learned in the form of state-action pairs. We generalize these …


Morphology Of Methane Hydrate Host Sediments, Keith W. Jones, Huan Feng, Stanmire Tomov, William J. Winters, Michael Eaton, Devinder Mahajan Feb 2005

Morphology Of Methane Hydrate Host Sediments, Keith W. Jones, Huan Feng, Stanmire Tomov, William J. Winters, Michael Eaton, Devinder Mahajan

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

The morphological features including porosity and grains of methane hydrate host sediments were investigated using synchrotron computed microtomography (CMT) technique. The sediment sample was obtained during Ocean Drilling Program Leg 164 on the Blake Ridge at water depth of 2278.5 m. The CMT experiment was performed at the Brookhaven National Synchrotron Light Source facility. The analysis gave ample porosity, specific surface area, mean particle size, and tortuosity. The method was found to be highly effective for the study of methane hydrate host sediments.


Synthesis Of Relatively Highly Magnetic Nano-Sized Nizn-Ferrite In Microemulsion At 45 Oc, Vuk Uskoković, Miha Drofenik Feb 2005

Synthesis Of Relatively Highly Magnetic Nano-Sized Nizn-Ferrite In Microemulsion At 45 Oc, Vuk Uskoković, Miha Drofenik

Pharmacy Faculty Articles and Research

The procedure for the preparation of NiZn-ferrite powder with average particle size of 10 nm and saturation magnetization of 50 emu/g by using precipitation reaction between acidified sulphate precursor salts and NH4OH as the precipitating agent in the water-in-oil domain of the microemulsion CTAB/1-hexanol/water at 45 oC is presented herein. TEM measurements have revealed relatively uniform morphology of the particles, which are associated in coral-like agglomerates. EDS measurements have been used for qualitative analysis of the sample, whereby FAAS measurement has been performed in order to reveal the proportion of the cations in the sample - Ni : Zn : …


Shemp: Secure Hardware Enhanced Myproxy, John Marchesini, Sean Smith Feb 2005

Shemp: Secure Hardware Enhanced Myproxy, John Marchesini, Sean Smith

Computer Science Technical Reports

While PKI applications differ in how they use keys, all applications share one assumption: users have keypairs. In previous work, we established that desktop keystores are not safe places to store private keys, because the TCB is too large. These keystores are also immobile, difficult to use, and make it impossible for relying parties to make reasonable trust judgments. Since we would like to use desktops as PKI clients and cannot realistically expect to redesign the entire desktop, this paper presents a system that works within the confines of modern desktops to shrink the TCB needed for PKI applications. Our …


Green Photoluminescence From Platinum(Ii) Complexes Bearing Silylacetylide Ligands, Fei Hua, Solen Kinayyigit, John R. Cable, Felix Castellano Feb 2005

Green Photoluminescence From Platinum(Ii) Complexes Bearing Silylacetylide Ligands, Fei Hua, Solen Kinayyigit, John R. Cable, Felix Castellano

Chemistry Faculty Publications

The synthesis, structural characterization, photoluminescence properties, and density functional theory analysis of three Pt(II) diimine complexes, Pt(dbbpy)(CdropCR)(2) [dbbpy = 4,4'-di(tert-butyl-2,2'-bipyridine; R = -SiMe3, -CdropC-SiMe3, or -t-Bu], are presented. The Pt(dbbpy)(CdropC-tBu)(2) complex serves as a carbon-based ligand structure for which the photophysical properties of the two silicon-bearing complexes are compared in dichloromethane. Pt(dbbpy)(CdropC-SiMe3)(2) and Pt(dbbpy)(CdropC-CdropC-SiMe3)(2) display visible absorptions with strong green emission (lambda(emmax) = 526 and 524 nm, respectively) while Pt(dbbpy)(CdropCt-Bu)(2) displays efficient, long-lived yellow emission (lambda(emmax) = 557 nm). Direct side by side comparisons of Pt(dbbpy)(CdropC-SiMe3)(2) and Pt(dbbpy)(CdropC-t-Bu)(2) suggest that the difference in excited state energy results from the relative …


Knowledge Transfer In Multi-Organizational Networks: Influence Of Causal And Outcome Ambiguities, Jennifer Priestley Jan 2005

Knowledge Transfer In Multi-Organizational Networks: Influence Of Causal And Outcome Ambiguities, Jennifer Priestley

Jennifer L. Priestley

Informed by the general concept of ambiguity related to knowledge transfer, we first identify and develop the concept of outcome ambiguity as to explain the ambiguity related to inter-organizational knowledge transfer among network firms, which, we argue, is not addressed by the well-established concept of causal ambiguity [34] [46]. Based upon this discussion, we develop the first two of our six hypotheses. Subsequently, we discuss two types of inter-organizational networks and how causal ambiguity and outcome ambiguity would be expected to behave within these network types. This discussion will form the basis for the remaining four of our six hypotheses. …


Finite-Difference Time-Domain Simulation Of A Liquid-Crystal Optical Phased Array, Xinghua Wang, Bin Wang, Philip Bos, James E. Anderson, John J. Pouch, Felix A. Miranda Jan 2005

Finite-Difference Time-Domain Simulation Of A Liquid-Crystal Optical Phased Array, Xinghua Wang, Bin Wang, Philip Bos, James E. Anderson, John J. Pouch, Felix A. Miranda

Philip J. Bos

Accurate modeling of a high-resolution, liquid-crystal-based, optical phased array (OPA) is demonstrated. The modeling method is extendable to cases where the array element size is close to the wavelength of light. This is accomplished through calculating an equilibrium liquid-crystal (LC) director field that takes into account the fringing electric fields in LC OPAs with small array elements and by calculating the light transmission with a finite-difference time-domain method that has been extended for use in birefringent materials. The diffraction efficiency for a test device is calculated and compared with the simulation.


Trustworthy Web Services: Actions For Now, Jia Zhang Jan 2005

Trustworthy Web Services: Actions For Now, Jia Zhang

Jia Zhang

For Web services to grow as predicted, researchers must not wait to address the challenges of software trustworthiness


Recovering Digital Evidence From Linux Systems, Philip Craiger Jan 2005

Recovering Digital Evidence From Linux Systems, Philip Craiger

J. Philip Craiger, Ph.D.

As Linux-kernel-based operating systems proliferate there will be an inevitable increase in Linux systems that law enforcement agents must process in criminal investigations. The skills and expertise required to recover evidence from Microsoft-Windows-based systems do not necessarily translate to Linux systems. This paper discusses digital forensic procedures for recovering evidence from Linux systems. In particular, it presents methods for identifying and recovering deleted files from disk and volatile memory, identifying notable and Trojan files, finding hidden files, and finding files with renamed extensions. All the procedures are accomplished using Linux command line utilities and require no special or commercial tools.


Hybrid Explicit-Implicit Fdtd-Fem Time-Domain Solver For Electromagnetic Problems, Kakhkhor Abdijalilov Jan 2005

Hybrid Explicit-Implicit Fdtd-Fem Time-Domain Solver For Electromagnetic Problems, Kakhkhor Abdijalilov

Dissertations

The Finite-Difference Time-Domain (FDTD) method and Finite-Element (FEM) method are numerical techniques used for solving Maxwell's electromagnetic equations. FDTD-FEM hybrid methods opt for combining the advantages of both FDTD and FEM. In this dissertation, signal processing techniques were used to analyze the FDTD stability condition. A procedure, which reduces time-sampling error yet preserves the stability of algorithm is proposed. Both explicit and implicit time-stepping schemes were treated in the framework of the developed method. An improved version of the implicit-explicit FEM-FDTD hybrid method was developed. The new method minimizes reflection from the interface between different types of grids. A class …


Characteristics Of Nanocomposites And Semiconductor Heterostructure Wafers Using Thz Spectroscopy, Hakan Altan Jan 2005

Characteristics Of Nanocomposites And Semiconductor Heterostructure Wafers Using Thz Spectroscopy, Hakan Altan

Dissertations

All optical, THz-Time Domain Spectroscopic (THz-TDS) methods were employed towards determining the electrical characteristics of Single Walled Carbon Nanotubes, Ion Implanted Si nanoclusters and Si1-xGex HFO2, SiO2 on p-type Si wafers.

For the nanoscale composite materials, Visible Pump/THz Probe spectroscopy measurements were performed after observing that the samples were not sensitive to the THz radiation alone. The results suggest that the photoexcited nanotubes exhibit localized transport due to Lorentz-type photo-induced localized states from 0.2 to 0.7THz. The THz transmission is modeled through the photoexcited layer with an effective dielectric constant described by a Drude …


Negotiation Of Software Requirements In An Asynchronous Collaborative Environment, Catherine Lowry Campbell Jan 2005

Negotiation Of Software Requirements In An Asynchronous Collaborative Environment, Catherine Lowry Campbell

Dissertations

The effect of task structure and negotiation sequence on collaborative software requirements negotiation is investigated. This work began with an extensive literature review that focused on current research in collaborative software engineering and, in particular, on the negotiation of software requirements and the requisite collaboration for the development of such requirements. A formal detailed experiment was then conducted to evaluate the effects of negotiation sequence and task structure in an asynchronous group meeting environment. The experiment tested the impact of these structures on groups negotiating the requirements for an emergency response information system. The results reported here show that these …


Characterizing The Evolution Of Operating Systems, Yi Peng Jan 2005

Characterizing The Evolution Of Operating Systems, Yi Peng

Dissertations

Examining the development and trends in software engineering technology is a huge undertaking. It is constantly evolving and affected by a large number of factors, which are themselves driven by a wide range of sub-factors. This dissertation is part of a long term project intended to analyze software engineering technology trends and how they evolve. This project is intended to analyze operating system trends and what are the factors that drive how they evolve. Basically, the following questions will be answered: "How to watch, predict, adapt to, and affect operating system's evolution trends?"

In previous research, YF Chen used statistical …


Live, Virtual, And Constructive Environments For Performance Support, John Michael Lacontora Jan 2005

Live, Virtual, And Constructive Environments For Performance Support, John Michael Lacontora

Dissertations

As military systems become more complex, the operation and support of these systems becomes intrinsically more difficult. The U.S. Army's current procurement process relies on industry to provide embedded training and performance support tools for the systems they produce. These tools are relatively new and in the early stages of development. As yet, they have failed to meet the needs of the technicians that are required to support these complex systems. Current efforts to provide enabling technologies that enhance the capabilities of automotive maintenance technicians are concentrated in three professional communities. First is the Performance Improvement community where work is …


Pattern Discovery In Structural Databases With Applications To Bioinformatics, Sen Zhang Jan 2005

Pattern Discovery In Structural Databases With Applications To Bioinformatics, Sen Zhang

Dissertations

Frequent structure mining (FSM) aims to discover and extract patterns frequently occurring in structural data such as trees and graphs. FSM finds many applications in bioinformatics, XML processing, Web log analysis, and so on. In this thesis, two new FSM techniques are proposed for finding patterns in unordered labeled trees. Such trees can be used to model evolutionary histories of different species, among others.

The first FSM technique finds cousin pairs in the trees. A cousin pair is a pair of nodes sharing the same parent, the same grandparent, or the same great-grandparent, etc. Given a tree T, our …


The Testing Of Semiconductor-Based Adsorption Modified Photosensitive Sensors For Their Response To A Volatile Organic Compound, Oxygen, Humidity, And Heating, Roberta Rosty Jan 2005

The Testing Of Semiconductor-Based Adsorption Modified Photosensitive Sensors For Their Response To A Volatile Organic Compound, Oxygen, Humidity, And Heating, Roberta Rosty

Dissertations

Two thin-film sensors, composed of different thicknesses (approximately 0.5 microns and 4.5 microns) of a cadmium sulfide layer coated with Rhodamine B fluorescent dye on a glass substrate, were tested for change in photoconductivity due to exposure to different concentrations of gaseous organic molecules in the parts-per-million (ppm) range.

It was theorized that the gaseous organic molecules would adsorb to the dyed semiconductor surface and that some energy would be transferred to the adsorbed analyte rather than to the cadmium sulfide semiconductor layer through the dye, thereby decreasing the photoconductivity of the surface in an amount proportional to the analyte …


Scattering Matrix Analysis Of Photonic Crystals, Valeriy Lukyanov Jan 2005

Scattering Matrix Analysis Of Photonic Crystals, Valeriy Lukyanov

Dissertations

Using a scattering matrix approach we analyze and study the scattering and transmission of waves through a two-dimensional photonic crystal which consists of a periodic array of parallel rods with circular cross sections. Without making any assumptions about normal incidence, single mode propagation, and sufficient inter-scatter separation in the direction of propagation, we show how to compute the transmission and reflection coefficients of these periodic structures. The method is based on the computation of a generalized scattering matrix for one column of the periodic structure.

We also develop an analytical method to analyze and to study the scattering and transmission …


An Optic Fiber Sensor For Partial Discharge Acoustic Detection, Xiaodong Wang Jan 2005

An Optic Fiber Sensor For Partial Discharge Acoustic Detection, Xiaodong Wang

Dissertations

Partial discharge (PD) is a very common problem in operating power transformers and is one of the factors that could lead to failure of power transformers, leading to power outage and expensive repairs. The acoustic wave induced by PD can be measured and used for monitoring, diagnosing, and locating potential failures in power transformers.

The effects of the temperature of the transformer and transformer oil are one of the very important parameters in PD and these effects are investigated in detail. The Fast Fourier Transform (FF1') is used to synthesize the measured data and results show that for periodic PD …


Presentation To Outside Las Vegas Foundation January 31, 2005, Public Lands Institute Jan 2005

Presentation To Outside Las Vegas Foundation January 31, 2005, Public Lands Institute

Presentations (PLI)

The Public Lands Institute is dedicated to strengthening the national fabric that is essential for the protection, conservation, and management of public lands.


Data Feed Management Automation : An Empirical Approach, Dibyendu Majumder Jan 2005

Data Feed Management Automation : An Empirical Approach, Dibyendu Majumder

Theses

This thesis proposes a framework for automation of data feed management and control. The framework can be classified into two broad areas i) building an ontology for a feed system and ii) developing a test suite, that is, a set of statistical models to analyze and diagnose feeds and formalize the results to feedback into the ontology. This thesis concentrates more on the latter and will only outline the course of action required for the former. Detailed descriptions of the statistical models that are part of the test suite are given and their strengths and weaknesses discussed. Practical results of …


2d Quantitative Structure Activity Relationship Modeling Of Methylphenidate Analogues Using Algorithm And Partial Least Square Regression, Noureen Wadhwaniya Jan 2005

2d Quantitative Structure Activity Relationship Modeling Of Methylphenidate Analogues Using Algorithm And Partial Least Square Regression, Noureen Wadhwaniya

Theses

Quantitative Structure-Activity Relationship (QSAR) analysis attempts to develop a predictive model of biological activity based on molecular descriptors. 2D QSAR uses descriptors, such as topological indices, that are independent of molecular conformation. A genetic algorithm - partial least squares (GA-PLS) approach was used to identify the molecular descriptors that correlate to the biological activity (binding affinity) of a set of 80 methylphenidate analogues and to construct a predictive model. The GA code was implemented using the fitness function (1-(n-1)(1-q2)/ (n - c)), where n is the number of compounds, c is the optimal number of components, and q …


The Role Of University Participation In Integrated Coastal Zone Management : A Case Study Of The Ria De Aviero, Amie Barbosa Figueiredo Jan 2005

The Role Of University Participation In Integrated Coastal Zone Management : A Case Study Of The Ria De Aviero, Amie Barbosa Figueiredo

Theses

The purpose of this investigation is to examine the efforts of the Universidade de Aveiro to create a public participation process and provide information for the management of the Ria de Aveiro, a lagoon system, in Portugal. This thesis examines whether universities are effective as coordinators and facilitators of Integrated Coastal Zone Management (ICZM). The Universidade de Aveiro, through the European Union-ICZM Demonstration Programme, spearheaded two projects, MARIA and ESGIRA-Maria, in efforts towards moving forward with ICZM in the area. A framework was created and then applied through a series of pilot-projects. Examination of the results of these pilot projects …