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Concentrations, Distributions And Chemical Speciation Of Zinc And Cadmium In The Equatorial And South Atlantic Ocean, Gonzalo G. Carrasco 2010 Old Dominion University

Concentrations, Distributions And Chemical Speciation Of Zinc And Cadmium In The Equatorial And South Atlantic Ocean, Gonzalo G. Carrasco

OEAS Theses and Dissertations

Certain trace metals are important cofactors in enzymatic systems and are thus, essential for life in the world's oceans. Two of these metals, Zn and Cd, are required by phytoplankton for enzymes that facilitate carbon uptake (Morel and Price, 2003). In seawater the total dissolved concentration of a metal (MTD) is distributed among different chemical species and this chemical speciation dictates a metal's bioavailability. Strong organic metal-binding ligands greatly affect the metal's chemical speciation in the ocean, potentially limiting phytoplankton growth by reducing the concentrations of Zn2+ and Cd2+, the bioavailable forms of these two ...


Historical Vegetation Reconstruction Using Spatial Modeling On Pre-Euro-American Data To Inform Ecosystem Restoration In The Driftless Area Of The U.S. Midwest, Kumudan Grubh 2010 Iowa State University

Historical Vegetation Reconstruction Using Spatial Modeling On Pre-Euro-American Data To Inform Ecosystem Restoration In The Driftless Area Of The U.S. Midwest, Kumudan Grubh

Graduate Theses and Dissertations

The potential future outcomes of ecological restoration and management activities can be partially understood by investigating reference conditions and historical processes that contributed to the variability of past ecosystems. Reconstructing pre-Euro-American vegetation from Public Land Survey (PLS) records provides spatially precise and extensive reference information from which such variability estimates can be developed. We thus mapped pre-Euro-American vegetation cover within the Driftless Area of the U.S. Midwest using PLS records. Our mapping employed a four step process. First, trees ambiguously designated by the Public Land surveyors were identified to species using logistic regression models. Next, conditionally specified regression models ...


Identifying And Eliminating Inconsistencies In Mappings Across Hierarchical Ontologies, Bhavesh Sanghvi 2010 Iowa State University

Identifying And Eliminating Inconsistencies In Mappings Across Hierarchical Ontologies, Bhavesh Sanghvi

Graduate Theses and Dissertations

Recent years have seen a rapid proliferation of information sources e.g., on the World-wide Web, in virtually every area of human endeavor. Such autonomous information sources are based on different ontologies, i.e., conceptualizations of the entities, properties, and relationships in the respective domains of discourse. However, practical applications (e.g., building predictive models from disparate data sources, assembling composite web services using components from multiple repositories) call for mechanisms that bridge the semantic gaps between disparate ontologies using mappings that express terms (concepts, properties, and relationships) in a target ontology in terms of those in one or more ...


An Experimental Study Of Subglacial Clast-Bed Contact Forces, John Louis Byers 2010 Iowa State University

An Experimental Study Of Subglacial Clast-Bed Contact Forces, John Louis Byers

Graduate Theses and Dissertations

The basal ice of sliding glaciers contains rock debris that is held in contact with the rock bed, resulting in abrasion that erodes the bed and friction that slows sliding. Abrasion rates and the magnitude of this friction are controlled by contact forces that clasts exert normal to the bed surface. These contact forces are dependant on the drag exerted on clasts by ice as it flows toward the bed. Recent subglacial measurements indicate that debris-bed friction has been underestimated by at least an order of magnitude. This underestimate may be the result of enhanced drag on particles and associated ...


A Novel Principal Component Analysis Method For Identifying Differentially Expressed Gene Signatures, Ai-ling Teh 2010 Iowa State University

A Novel Principal Component Analysis Method For Identifying Differentially Expressed Gene Signatures, Ai-Ling Teh

Graduate Theses and Dissertations

Microarray data sets contain a wealth of information on the gene expression levels for thousands of genes for small number of different conditions called assays. But, the information is hidden by high noise levels, and low signal levels. Data mining techniques are used to extract the information of genes related to the assays. This work proposed a powerful principal component analysis (PCA) based method in extend of PCA approach of Rollins et. al. (2006). The proposed method is able to generate gene signatures that expressed the most differently between two assay groups in a microarray data set.

This work developed ...


Functionalized Mesoporous Silica Nanoparticles (Msns) For Applications In Drug Delivery And Catalysis, Wei Huang 2010 Iowa State University

Functionalized Mesoporous Silica Nanoparticles (Msns) For Applications In Drug Delivery And Catalysis, Wei Huang

Graduate Theses and Dissertations

Well-ordered mesoporous silica nanoparticles (MSNs) feature a great number of important characteristics including large surface area and pore volume, tunable pore diameter, uniform particle size, and good biocompatibility. The feasibility of selective functionalization on the exterior and interior surface of MSNs makes them applicable in areas as diverse as sorption, separation, sensing, drug delivery, and catalysis.

Poly(L-lysine) was immobilized onto the outer surface of amine functionalized MSN via ring-opening polymerization. The poly(L-lysine) coated MSN (PLL-MSN) could be internalized by human cervical cancer (HeLa) cells with extremely high efficiency, which made the delivery of a large amount of drugs ...


Metal Thin Film Growth On Multimetallic Surfaces: From Quaternary Metallic Glass To Binary Crystal, Dapeng Jing 2010 Iowa State University

Metal Thin Film Growth On Multimetallic Surfaces: From Quaternary Metallic Glass To Binary Crystal, Dapeng Jing

Graduate Theses and Dissertations

N/A


From Semantic Security To Chosen Ciphertext Security, Sahnghyun Cha 2010 Iowa State University

From Semantic Security To Chosen Ciphertext Security, Sahnghyun Cha

Graduate Theses and Dissertations

A chosen ciphertext attack against the RSA encryption standard PKCS#1 v1.5 was introduced by Daniel Bleichenbacher at Crypto '98. This attack was the first example where an adaptive chosen ciphertext attack is not just a theoretical concept but a practical method to crack a semantically secure encryption scheme.

This paper reviews the notion of the semantic security which was believed to be secure enough in reality and the reason for which this belief was denied. The paper also presents a demonstration of the Bleichenbacher's attack by using a simplified version of PKCS#1 v1.5 format.


Theoretical Studies Of H-Passivated Silicon Nanowires, Silicon Surface Systems And Si/Ge Core/Shell Nanowires, Ning Lu 2010 Iowa State University

Theoretical Studies Of H-Passivated Silicon Nanowires, Silicon Surface Systems And Si/Ge Core/Shell Nanowires, Ning Lu

Graduate Theses and Dissertations

Global structural optimization with Genetic Algorithm and first principle analysis have been performed on the Silicon nanowires, Ag induced Si surface reconstruction systems and Si/Ge core/shell nanowires. By using genetic algorithm combined with ab-initio calculation, we determined the atomic structures H-passivated <110> and <112> silicon nanowires. we found that at certain values of the hydrogen chemical potential the nanowires can take relatively stable structures in <112> SiNWs with rectangular cross sections bounded by monohydride {110} and {111} facets with dihydride wire edges. In <110> SiNWs cross section of the nanowire evolves from chains of six-atom rings to fused pairs of such chains ...


Universality In Algorithmic Self-Assembly, Scott Summers 2010 Iowa State University

Universality In Algorithmic Self-Assembly, Scott Summers

Graduate Theses and Dissertations

Tile-based self-assembly is a model of "algorithmic crystal growth" in which square "tiles" represent molecules that bind to each other via specific and variable-strength bonds on their four sides, driven by random mixing in solution but constrained by the local binding rules of the tile bonds. In the late 1990s, Erik Winfree introduced a discrete mathematical model of DNA tile assembly called the abstract Tile Assembly Mode. Winfree proved

that the Tile Assembly Model is computationally universal, i.e., that any Turing machine can be encoded into a finite set of tile types whose self-assembly simulates that Turing machine. In ...


Angle-Resolved Photoemission Spectroscopy (Arpes) Studies Of Cuprate Superconductors, Ari Deibert Palczewski 2010 Iowa State University

Angle-Resolved Photoemission Spectroscopy (Arpes) Studies Of Cuprate Superconductors, Ari Deibert Palczewski

Graduate Theses and Dissertations

This dissertation is comprised of three different angle-resolved photoemission spectroscopy (ARPES) studies on cuprate superconductors. The first study compares the band structure

from two different single layer cuprates Tl2Ba2CuO6+delta (Tl2201) Tc,max — 95 K and

(Bi1:35Pb0:85)(Sr1:47La0:38)CuO6+delta (Bi2201) Tc,max — 35 K. The aim of the study was to provide some insight into the reasons why single layer cuprate's maximum transition temperatures are so different. The study found two major differences in the band structure. First, the Fermi surface segments close to ...


Summer Food Habits And Gill Raker Morphology Of Seven Catostomid Species In Iowa Rivers, Jason Spiegel 2010 Iowa State University

Summer Food Habits And Gill Raker Morphology Of Seven Catostomid Species In Iowa Rivers, Jason Spiegel

Graduate Theses and Dissertations

Previous attempts to age Carpiodes spp. have focused on the use of scales or dorsal fin rays. Past studies indicate that obtaining age estimates from these structures in other species is difficult and inconsistent. We examined between reader precision of age estimates of scales and pectoral fin rays for 123 highfin carpsuckers Carpiodes velifer, 174 quillback carpsuckers C. cyprinus and 135 river carpsucker C. carpio. Precision of age estimates was assessed through measures of agreement, the coefficient of variation (CV), and a confidence rating. Exact agreement between readers was higher for fin rays (highfin carpsucker = 82.1%; quillback carpsucker = 75 ...


A Privacy-Preserving Authentication Protocol For Smart Tags, Michael Chih Huong Fong 2010 Iowa State University

A Privacy-Preserving Authentication Protocol For Smart Tags, Michael Chih Huong Fong

Graduate Theses and Dissertations

RFID system has become a technology that many companies would like to adopt as it provides convenience to our society. Increasing competitiveness in the industry has reduced the cost of the technology, but it also raises considerable privacy concerns. Among many RFID applications that have made major impacts on various industries, the RFID-based authentication system has become a solution to resolve a number of issues, for instances, theft, compromised brand, lack of inventory control, supply chain inefficiencies, and etc. Many authentication protocols based on symmetric challenge-response scheme have been developed in order to ensure preservation of privacy. However, many of ...


Understanding The J/Psi Production Mechanism At Phenix, Todd Kempel 2010 Iowa State University

Understanding The J/Psi Production Mechanism At Phenix, Todd Kempel

Graduate Theses and Dissertations

The large mass of the charm quark, along with the abundance of J/ψ mesons observed from proton-proton collisions at PHENIX, allow for new measurements which are sensitive to basic properties of QCD. Two measurements are presented in this document: a transverse single-spin asymmetry (SSA) of J/ψ production and the angular distribution for decay leptons in various reference frames. The decay distribution is directly sensitive to the J/ψ production mechanism, while the transverse SSA is also sensitive to the distribution of gluons in a transversely polarized proton. Taken together, the two measurements provide a wealth of information about ...


Development Of Fluorescence-Based Methods For Non-Invasive Measurement Of Integrin Microclustering, Deepak Dibya 2010 Iowa State University

Development Of Fluorescence-Based Methods For Non-Invasive Measurement Of Integrin Microclustering, Deepak Dibya

Graduate Theses and Dissertations

In order to better understand the cell signaling process, non-invasive methods to measure the integrin microclustering and examine the factors affecting the dynamics of these clusters are needed. This dissertation is focused on the development of non-invasive analytical tools to investigate the role of cytoplasmic proteins and cholesterol on the nanoscale dynamic localization of integrins using a technique called FRET, fluorescence resonance energy transfer. FRET is used to detect the proximity of molecules at nanometer distances (1-10 nm) and can be applied in diverse ways with various microscope configurations. FRET images obtained with such setups can be used to quantify ...


Virginia Game Fish Tagging Program Annual Report 2009, John A. Lucy, Lewis Gillingham 2010 Virginia Institute of Marine Science

Virginia Game Fish Tagging Program Annual Report 2009, John A. Lucy, Lewis Gillingham

Reports

Through 2009, the Virginia Game Fish Tagging Program has maintained a 15-year database for tagged and recaptured fish. The program is a cooperative project of the Virginia Saltwater Fishing Tournament (under the Virginia Marine Resources Commission/VMRC) and the Virginia Institute of Marine Science (VIMS) of the College of William and Mary (under VIMS Sea Grant Marine Extension Program).


Shallow Water Dredging, Center for Coastal Resources Management, Virginia Institute of Marine Science 2010 William & Mary

Shallow Water Dredging, Center For Coastal Resources Management, Virginia Institute Of Marine Science

Reports

Rivers & Coast is a periodic publication of the Center for Coastal Resources Management, Virginia Institute of Marine Science. The goal of Rivers & Coast is to keep readers well informed of current scientific understanding behind key environmental issues related to watershed rivers and coastal ecosystems of the Chesapeake Bay


A Mathematical Analysis Of Multiple-Target Selex, Yeon-jung Seo 2010 Iowa State University

A Mathematical Analysis Of Multiple-Target Selex, Yeon-Jung Seo

Graduate Theses and Dissertations

This thesis develops a mathematical model of the biological procedure SELEX (Systematic Evolution of Ligands by EXponential Enrichment). The procedure is an in vitro method for identifying nucleic acid (NA) molecules that have an ability to bind tightly and specifically to target species of interest, such as small organic molecules, peptides or proteins.

We explore two main algorithms: multiple target (positive) SELEX and alternate SELEX. The schemes are considered as discrete time dynamical systems, and the limiting (steady-state) behaviors of the processes are characterized by the initial parameters of each system: concentration of total targets, concentration of a pool of ...


Panorama - A Software Maintenance Tool, Naga Bhagvanth Ram Vattumalli 2010 Iowa State University

Panorama - A Software Maintenance Tool, Naga Bhagvanth Ram Vattumalli

Graduate Theses and Dissertations

Much of the effort in software maintenance is spent on finding relevant information and on program comprehension. Of the several challenges encountered during this process, some are: a) inadequate documentation, b) the developer doing the maintenance activity may not be the one who actually developed it and may be unfamiliar with the application domain (in addition to the unfamiliar code), c) information overload, and d) the relevant code may be scattered across multiple files of different types making it harder to find. Existing documentation in the form of Javadoc is inadequate in providing a global view of the working of ...


Mesoporous Metal Oxide Materials For Catalysis And Biotechnology Applications, Enruo Guo 2010 Iowa State University

Mesoporous Metal Oxide Materials For Catalysis And Biotechnology Applications, Enruo Guo

Graduate Theses and Dissertations

The research presented here involves the application of mesoporous silica nanoparticles in heterogeneous catalysis and biomedical study.

Since the discovery of mesoporous silica nanoparticle (MSN), it has been studied as solid catalyst support. We studied the catalytic activity of CO hydrogenation and the selectivity to C2 oxygenates by encapsulating monodispersed rhodium (Rh) nanoparticles during the synthesis of MSN in situ, and further modified by manganese oxide. The catalysts showed a higher reactivity in CO hydrogenation and a better selectivity to the desired product ethanol.

Structure directing agent plays a big role in mesophase structure, as well as affecting the distribution ...


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