Physical Sciences and Mathematics Commons^™

Modulation Of Restriction Enzyme Pvuii Activity By Metal Ion Cofactors, Charulata Bhaskaran Prasannan

Dissertations

Metal ions like Ca2+, Mn2+, Tb3+, Eu3+ etc., can bind at the active site and have varying effects on the enzymatic activity. In a crystal structure with DNA, two Ca2+ ions were bound to the active site of each PvuII monomer, and the metals share the ligands. Ca2+ ions promote DNA binding and not cleavage in many nucleases. We explored the role of Mg2+ and Ca2+ binding at the metal binding sites of PvuII to elucidate the role of each metal site. We monitored the cleavage kinetics of PvuII in presence of mixed metals. The cleavage kinetics data for Ca2+ …

Replacing Hydrogen Bonds With Coordinate Covalent Bonds In Coordination Networks, Colin Stewart Rodger

Dissertations

The overall theme of the dissertation is that metal ions such as silver(I) can replace H+ in hydrogen bonded organic frameworks. Because organic solids have been extensively studied, we can insert metal ions into the supramolecular assemblies, thus creating predictable coordination solids of varying dimensions. One example of an organic solid tested involves the organic compounds terephthalic and isophthalic acids. These dicarboxylic acids have previously been shown to self-assemble into tape-like structures via hydrogen bonding, with neighboring dicarboxylic acids located at angles of 180° and 120° respectively. By substituting the hydrogen bonds with coordination metal-ligand bonds similar assemblies are formed. …

Theoretical Study Of Localized Surface Plasmons Of Metal Nanoparticles, Clusters And Embedded Metal Nanoparticles In Matrices, Masoud Shabani Nezhad Navrood

Dissertations

Localized surface plasmons resonances (LSPRs) in metallic nanoparticles (NPs) arise from the interactions between incident light and conduction electrons and have attracted enormous research interest in recent years both for their fundamental nature as well as applications in interdisciplinary areas of sciences such as biological imaging, plasmonic photo-thermal therapy, photovoltaics, and plasmonic sensors. LSPRs are strongly localized and depend on the shape, size, the composition of the NPs, the polarization direction of the incident light, refractive index (RI) of the surrounding medium as well as on the chemical environment that surrounded NPs. Although significant research has progressed both theoretically and …

The Program Evaluation Standards Applied For Metaevaluation Purposes: Investigating Interrater Reliabiity And Implications For Use, Lori A. Wingate

Dissertations

Metaevaluation is the evaluation of evaluation. Metaevaluation may focus particular evaluation cases, evaluation systems, or the discipline overall. Leading scholars within the discipline consider metaevaluation to be a professional imperative, demonstrating that evaluation is a reflexive enterprise. Various criteria have been set forth for what constitutes excellence in evaluation. In the context of educational program evaluation, the dominant criteria are the Program Evaluation Standards, developed by the developed by the Joint Committee on Standards for Educational Evaluation.

There has been widespread acceptance and application of the Program Evaluation Standards, and their use is advocated by major organizations and several of …

Anomaly Detection Techniques For Ad Hoc Networks, Chaoli Cai

Dissertations

Anomaly detection is an important and indispensable aspect of any computer security mechanism. Ad hoc and mobile networks consist of a number of peer mobile nodes that are capable of communicating with each other absent a fixed infrastructure. Arbitrary node movements and lack of centralized control make them vulnerable to a wide variety of unknown and known attacks from inside as well as from outside. In this dissertation we propose two efficient statistical techniques for anomaly detection for these networks.

In order to take into account incomplete testing samples and the interaction among multiple features, we present BANBAD •- a …

Kendall's Tau And Spearman's Rho For Zero-Inflated Data, Ronald Silva Pimentel

Dissertations

Zero-inflated continuous distributions have positive probability mass at zero in addition to a continuous distribution. Such type of data can be encountered, for example, in medical, environmental and financial research. The main focus of this research is to study the association of nonnegative random variables, both having a positive probability mass at zero. New estimators of the classical measures of association, Kendall's tau and Spearman's rho, appropriate for the zero-inflated distributions, are proposed and their asymptotic distributions are derived. Performance of the estimators is assessed by a Monte Carlo simulation study. New ideas are illustrated by a real data example.

A Two-Sample Adaptive Procedure Based On The Log-Rank And Peto And Peto's Wilcoxon Tests, Annie A. Tordilla

Dissertations

It has been shown that under a location-scale model y = μ + βz + σε at where y is right censored, the Log-Rank test is asymptotically efficient for the Extreme minimum value error distribution while Peto and Peto's Wilcoxon test is asymptotically efficient for the Logistic error distribution. We propose a two-sample adaptive test, which first selects between Extreme minimum value and Logistic error distribution as to which is a better fit to the data, then performs the asymptotically efficient test (Log-Rank or Peto and Peto's Wilcoxon test) for the selected distribution. The performance of the adaptive test is …

Metaevaluation Of Hiv/Aids Prevention Intervention Evaluations In Sub Saharan Africa With A Specific Emphasis On Implications For Women And Girls, Tererai Mafukidze Trent

Dissertations

Despite numerous attempts by international agencies to halt the spread of Human Immunodeficiency Virus (HIV) and Acquired Immunodeficiency Syndrome (AIDS), nowhere has the impact of HIV/AIDS been felt more acutely than among women and girls in Sub-Saharan Africa (SSA). SSA women account for 59% of adults over the age of 15 living with HIV/AIDS and 76% of those 15-24 who are infected (United Nations Joint Programme on HIV/AIDS [UNAIDS], 2007).

The evidence on gender disparities in infection rates is indisputable; there is an urgent need to identify what is missing in HIV/AIDS prevention interventions: What is the evidence based upon …

Investigation Of Novel Thiol "Click" Reactions, Justin William Chan

Dissertations

The thio-Michael addition reaction is traditionally considered a base catalyzed reaction which involves high catalyst concentrations and long reaction times. This reaction utilizes potent, simple nucleophiles to catalyze the reaction, decreases the catalyst concentration and greatly increases the reaction times. The free radical mediated thiol-ene click reaction uses light or heat and an initiator to catalyze the rapid and quantitative addition of thiols to most electron rich enes without the formation of side products and in the absence of solvent. Recently, the thiol-ene click reaction has been exploited for these reasons in materials science and organic synthesis. The research herein …

Reactor R&D: Synthesis And Optimization Of Metallic Nitride Fullerenes And The Introduction Of Two New Classes Of Endohedral Metallofullerenes, Metallic Nitride Azafullerenes And Oxo-Metallic Fullerenes, Curtis Earl Coumbe

Dissertations

Metallic nitride fullerenes (MNFs) were discovered in 1999. This class of endohedral fullerenes show promise in a new diverse range of useful applications. Since then, focus has shifted to the selective synthesis of these molecules with yields that would accommodate adequate sample distribution. Using the electric arc method, the traditional yield of these molecules has been very low (i.e. < 5 mg), and only a small percentage of the fullerene products (i.e. < 5%). This dissertation introduces the novel CAPTEAR (Chemically Adjusting Plasma Temperature, Energy, And Reactivity) method that allows the targeted synthesis of MNFs in high purity and yield. This method utilizes a nontraditional oxidizing method for fullerene synthesis that has not only provided optimization of MNFs, but also resulted in the discovery of two new classes of fullerenes: metallic nitride azafullerenes (MNAFs) and oxo-metallic fullerenes (OMFs). Evidence suggests that the nitrogen of the MNAF cage provides stability for the trimetallic nitride clusters, while the OMFs are the first fullerenes to encapsulate oxygen and incorporate a seven atom cluster inside a Cgo cage.

Other efforts to increase yields resulted from scaling up production of fullerenes by using larger quantities of starting materials. These larger quantities required energy (electrical current) beyond the capacity of the traditional electric arc generator. Therefore, a new electric arc generator …

Investigation Of The Relationship Between Polymer Structures And Thermal, Mechanical, Viscoelastic Properties, Ethem Kaya

Dissertations

The research presented in this dissertation involves four distinct areas: physical crosslinking systems, UV curable coatings for enhanced oxygen and carbon dioxide barrier properties, synthesis, and investigation of melting behavior/crystallinity relations of linear polyamides with long alkyl chains, and synthesis and characterization of cyclic diamides as precursors to linear polyamides 6 4.

The physical crosslinking section involves synthesis of monomers and polymers bearing cyclodextrin and adamantane pendent groups, and investigation of non-covalent interactions between these polymers (Chapter II). Two methacrylate monomers bearing cyclodextrin and adamantane were synthesized, and copolymerized with poly(ethylene glycol) methyl ether methacrylate. The specific interaction between copolymers …

Application Of Molecular Modeling In The Noncovalent Dispersion Of Carbon Nanomaterials, Praveen Kumar Madasu

Dissertations

Molecular modeling is a powerful tool to better understand the intermolecular interactions of carbon nanostructures. It provides structures and energies not easily obtainable from experiments and predicts properties that can be tested experimentally. Intermolecular interactions play an important role in the aggregation of various carbon nanomaterials. Three molecular modeling studies of carbon nanomaterial dispersions are presented in this dissertation, with an emphasis on illustrating how effective these theoretical techniques are in providing insight on the selection of dispersion additives. To achieve our goals, we employed molecular mechanics based methods, along with semi-empirical methods, and quantum mechanical methods, such as density …

Random And Block Copolymers Of Poly(Dodecamethyleneterephthalamide), Theodore Frank Novitsky Jr.

Dissertations

The following dissertation focuses on the synthesis and characterization of poly(dodecamethylene terephthalamide) (PA-12,T) and novel copolymers. Chapter I details the synthesis of PA-12,T homopolymer by melt condensation polymerization. A series of homopolymers with different molecular weights were obtained by adjusting the stoichiometry of the polymerization using 1,12-diaminododecane, terephthalic acid and benzoic acid. End group 13C NMR spectroscopy resonances were obtained by correlating peak intensities with intrinsic viscosity values. From the NMR data, total end group concentrations and molecular weights were determined for each sample. The data exhibited a linear trend when plotting log (IV) versus log (Mn), and previously unknown …

Preparation And Characterization Of Thiol Based Polymeric Materials, Junghwan Shin

Dissertations

The thiol click-type reaction is one of the most efficient chemical processes that can undergo at room temperature in the benign organic solvent providing excellent opportunity in the fabrication of new materials as well as development of new manufacturing processes. Moreover, the versatility of thiol click-type reactions with many different functional groups such as ene, yne, epoxy, isocyanate, and alkyl halide is the important aspect that should be differentiated from the classic azide-alkyne click chemistry. Although, there are tremendous studies on many areas using thiol click-type reactions, the efficiency and utilities for the material applications have been barely explored. Especially, …

Tuning Pig Liver Esterase Enantioselectivity For The Synthesis Of Unnatural Serine And Tyrosine Analogues, Dale Anthony Rosado Jr.

Dissertations

The synthesis of disubstituted and homologated unnatural amino acids and the development of a mass spectrometry based assay for enantioselectivity are presented here. Disubstituted and homologated unnatural amino acids have proven to be effective for the treatment of diseases and for use as imaging agents. Peptides that contain unnatural amino acids have also proven to be effective treatments for various disease states including cancer. The potential to evaluate such unnatural amino acids for pharmaceutical properties is limited by the available syntheses. No method currently exists that will allow for the synthesis of homochirally similar unnatural amino acids from a common …

Study Of Thermal Frontal Polymerization Utilizing Reactive And Non-Reactive Additives, Veronika Grace Viner

Dissertations

Thermal frontal polymerization is a process that involves a propagating front travelling through a monomer/initiator solution and converting monomer into polymer. The effects of different reactive and non-reactive additives on front temperature, front velocity, and pot life were studied in a thermal frontal polymerization system of multifunctional acrylates. One issue with thermal frontal polymerization of acrylate monomers is the amount of smoke and fumes produced due to high front temperatures. The effect of thermally-expandable microspheres was studied utilizing a variety of monomers. Solid additives including fillers, inert phase changer materials, and high thermal conductive fillers were investigated. The addition of …

Transcript Analysis Of The Cso Operon And Characterization Of Two Sets Of Conserved Bacterial Microcompartment Genes In The Model Organism Halothiobacillus Neapolitanus, Fei Cai

Dissertations

This study was designed to achieve better understanding of (1) how carboxysome genes are regulated and expressed to yield with precise relative ratios and (2) the in vivo roles of two sets of conserved bacterial microcompartment genes, namely the three csoSl and two csoS4 genes of H. neapolitanus, in the biogenesis and function of the carboxysome. For the first goal, a detailed transcriptional profile of carboxysomal genes in H. neapolitanus was established using absolute quantification real-time RT-PCR and transcript ends analysis. This transcriptional profile revealed that a single promoter, denoted cso promoter, was located upstream from the clustered carboxysomal genes. …

The Multilevel Structures Of Nurbs And Nurblets On Intervals, Weiwei Zhu

Dissertations

This dissertation is concerned with the problem of constructing biorthogonal wavelets based on non-uniform rational cubic B-Splines on intervals. We call non-uniform rational B-Splines ``NURBs", and such biorthogonal wavelets ``NURBlets". Constructing NURBlets is useful in designing and representing an arbitrary shape of an object in the industry, especially when exactness of the shape is critical such as the shape of an aircraft. As we know presently most popular wavelet models in the industry are approximated at boundaries. In this dissertation a new model is presented that is well suited for generating arbitrary shapes in the industry with mathematical exactness throughout …

Processing Techniques For Partial Tree-Pattern Queries On Xml Data, Pawel Placek

Dissertations

In recent years, eXtensible Markup Language (XML) has become a de facto standard for exporting and exchanging data on the Web. XML structures data as trees. Querying capabilities are provided through patterns matched against the XML trees. Research on the processing of XML queries has focused mainly on tree-pattern queries. Tree-pattern queries are not appropriate for querying XML data sources whose structure is not fully known to the user, or for querying multiple data sources which structure information differently. Recently, a class of queries, called Partial Tree-Pattern Queries (PTPQs) was identified. A central feature of PTPQs is that the structure …

In-Group / Out-Group Dynamics And Effectiveness In Partially Distributed Teams, Faina Privman

Dissertations

When organizations collaborate they often do so using partially distributed teams (PDTs). In a Partially Distributed Team there exist at least two distinct sub-groups. In addition, at least one of the sub-groups has two or more members that are geographically co-located. Co-located members can meet face to face; chat in the hallway; have lunch together; and otherwise socialize with one another. On the other hand, remote members must rely on technology to communicate and work together. This distinct characteristic of partially distributed teams makes them especially susceptible to the In-Group / Out Group dynamic (Huang and Ocker, 2006). This dynamic …

High Resolution Solar Observations From First Principles To Applications, Angelo P. Verdoni

Dissertations

The expression "high-resolution observations" in Solar Physics refers to the spatial, temporal and spectral domains in their entirety. High-resolution observations of solar fine structure are a necessity to answer many of the intriguing questions related to solar activity. However, a researcher building instruments for high-resolution observations has to cope with the fact that these three domains often have diametrically opposed boundary conditions. Many factors have to be considered in the design of a successful instrument. Modern post-focus instruments are more closely linked with the solar telescopes that they serve than in past. In principle, the quest for high-resolution observations already …

Design Development And Evaluation Of Collario, A Group Support System For Collaborative Scenario Creation, Xiang Yao

Dissertations

In the fields of Emergency Management and Business Continuity Planning, scenarios are a widely used tool for planning, training and knowledge sharing purposes. The ability to create and discuss emergency scenarios in virtual teams can lead to many potential applications, such as discussing emergency scenarios by world-wide experts, conducting on-line exercises, and creating Communities of Practices. Existing scenario creation systems, like NxMsel provided by FEMA, allow distributed groups to create scenarios together. However, collaborative support in these systems is generally limited.

This dissertation explores an innovative solution to provide various types of collaboration support around a knowledge structure and uses …

Reduced Order Models For Fluid-Structure Interaction Systems By Mixed Finite Element Formulation, Ye Yang

Dissertations

In this work, mixed finite element formulations are introduced for acoustoelastic fluid- structure interaction (FSI) systems. For acoustic fluid, in addition to displacement- pressure (u/p) mixed formulation, a three-field formulation, namely, displacement-pressure-vorticity moment formulation (u - p -Λ) is employed to eliminate some zero frequencies. This formulation is introduced in order to compute the coupled frequencies without the contamination of nonphysical spurious non-zero frequencies. Furthermore, gravitational forces are introduced to include the coupled sloshing mode. In addition, u/p mixed formulation is the first time employed in solid. The numerical examples will demonstrate that the mixed formulations are capable of predicted …

Carbon Nanotube Electronic Structures As Anti-Corrosion Coatings, Sreeya Sreevatsa

Dissertations

A new concept of corrosion prevention is considered in this study. Diode-like and transistor-like structures have been fabricated and analyzed in the study of ionic flow through the resulting potential barriers. The structures were made of functionalized carbon nanotubes. Carbon nanotubes are known for many remarkable properties among which is being chemically inert. Taking advantage of this property, a study of corrosion of steel was undertaken.

In the first case study, successive layers of functionalized carbon nanotubes were deposited to form p-n junctions on steel substrates. It was demonstrated that the corrosion was indeed impeded by the potential barrier formed …

Probing The Complex Magnetic, Electronic And Structural Properties In Correlated Manganese Oxides, Peng Gao

Dissertations

Rare-earth Manganese Oxides (RMnO₃) exhibit two distinct structural phases: the orthorhombic structure and the hexagonal structure. The doped orthorhombic phase exhibits a metal to insulator transition, charge ordering and a strong response of electron transport properties to magnetic fields (colossal magneto-resistance). At low temperatures, this system may also exhibit a finite polarization which couples to external magnetic fields. The hexagonal phase is known to have a large spontaneous polarization at high temperatures which couples to the low temperature magnetic order. These materials are important from the basic point of view of understanding strong electronic correlations and …

Photoionization Of Rare Gas Clusters, Huaizhen Zhang

Dissertations

This thesis concentrates on the study of photoionization of van der Waals clusters with different cluster sizes. The goal of the experimental investigation is to understand the electronic structure of van der Waals clusters and the electronic dynamics. These studies are fundamental to understand the interaction between UV-X rays and clusters. The experiments were performed at the Advanced Light Source at Lawrence Berkeley National Laboratory. The experimental method employs angle-resolved time-of-flight photoelectron spectrometry, one of the most powerful methods for probing the electronic structure of atoms, molecules, clusters and solids.

The van der Waals cluster photoionization studies are focused on …

Topology Control Using Joint Power And Beam-Width Control In Hybrid Rf/Fso Mesh Networks, Osama Awwad

Dissertations

Most wireless networks are deployed strictly in the radio frequency (RF) domain, since RF channels provide natural support for radial broadcast operations. However, the downside of RF channels is that they introduce many limiting externalities that make providing scalable quality of service (QoS) support difficult, if not intractable. These well-known technical challenges include bandwidth scarcity, lack of security, high interference, and high bit error rates.

Faced with such daunting obstacles to QoS, the use of Free Space Optics (FSO) for wireless communications has been proposed in which it has the potential to support higher link data rates compared to present …

Meta Analyses Of Multiple Baseline Time Series Design Intervention Models For Dependent And Independent Series, Oluwagbohunmi Adetunji Awosoga

Dissertations

Most wireless networks are deployed strictly in the radio frequency (RF) domain, since RF channels provide natural support for radial broadcast operations. However, the downside of RF channels is that they introduce many limiting externalities that make providing scalable quality of service (QoS) support difficult, if not intractable. These well-known technical challenges include bandwidth scarcity, lack of security, high interference, and high bit error rates.

Faced with such daunting obstacles to QoS, the use of Free Space Optics (FSO) for wireless communications has been proposed in which it has the potential to support higher link data rates compared to present …

Statistical Procedures For Bioequivalence Analysis, Srinand Ponnathapura Nandakumar

Dissertations

Applicants submitting a new drug application (NDA) or new animal drug application (NADA) under the Federal Food, Drug, and Cosmetic Act (FDC Act) are required to document bioavailability (BA). A sponsor of an abbreviated new drug application (ANDA) or abbreviated new animal drug application (ANADA) must document first pharmaceutical equivalence and then bioequivalence (BE) to be deemed therapeutically equivalent to a reference listed drug (RLD). The Average (ABE), Population (PBE) and Individual (IBE) bioequivalence have been used to establish the equivalence in the pharmaco-kinetics of drugs.

The current procedure of PBE uses Cornish Fisher's (CF) expansion on small samples. Since …

Test Procedures For Equality Of Two Variances In Delta Distributions, Jezaniah Kira Sarion Tena

Dissertations

Statistical literature on testing equality of variances is very broad, encompassing a great number of distributional variations. However, the case of a zero-inflated nonnegative continuous random variable has not yet been considered. Such distribution is specified by a positive probability that the variable assumes a true zero value, together with a conditional distribution for the positive values of the variable.

This study considers the special case, delta distribution, where the positive values come from the lognormal distribution. Test procedures were developed using a statistic based on Gini's Mean Difference. Since the asymptotic distribution of the test statistic was shown to …