Physical Sciences and Mathematics Commons^™

The Contribution Of Marine Aggregate-Associated Bacteria To The Accumulation Of Pathogenic Bacteria In Oysters: An Agent-Based Model, Andrew M. Kramer, J. Evan Ward, Fred C. Dobbs, Melissa L. Pierce

OES Faculty Publications

Bivalves process large volumes of water, leading to their accumulation of bacteria, including potential human pathogens (e.g., vibrios). These bacteria are captured at low efficiencies when freely suspended in the water column, but they also attach to marine aggregates, which are captured with near 100% efficiency. For this reason, and because they are often enriched with heterotrophic bacteria, marine aggregates have been hypothesized to function as important transporters of bacteria into bivalves. The relative contribution of aggregates and unattached bacteria to the accumulation of these cells, however, is unknown. We developed an agent-based model to simulate accumulation of vibrio-type bacteria …

Dynamics Of Plume-Triple Junction Interaction: Results From A Series Of Three-Dimensional Numerical Models And Implications For The Formation Of Oceanic Plateaus, Mladen Dordevic, Jennifer Georgen

OES Faculty Publications

Mantle plumes rising in the vicinity of mid-ocean ridges often generate anomalies in melt production and seafloor depth. This study investigates the dynamical interactions between a mantle plume and a ridge-ridge-ridge triple junction, using a parameter space approach and a suite of steady state, three-dimensional finite element numerical models. The top domain boundary is composed of three diverging plates, with each assigned half-spreading rates with respect to a fixed triple junction point. The bottom boundary is kept at a constant temperature of 1350°C except where a two-dimensional, Gaussian-shaped thermal anomaly simulating a plume is imposed. Models vary plume diameter, plume …

Effects Of Temperature, Irradiance And Pco2 On The Growth And Nitrogen Utilization Of Prorocentrum Donghaiense, Zhangxi Hu, Margaret R. Mulholland, Ning Xu, Shunshan Duan

OES Faculty Publications

Environmental factors such as temp erature, irradiance, and nitrogen (N) supply affect the growth of Prorocentrum donghaiense, but the interactive effects of these physical factors and the effects of atmospheric CO₂ (pCO₂) on growth and N uptake have not been examined. We compared growth kinetics of P. donghaiense grown on 4 different N substrates (nitrate [NO₃ -], ammonium [NH₄ +], urea, and glutamic acid [glu]) with respect to temperature, irradiance, and pCO₂. Temperature (15 to 30°C) had a positive effect on growth (max. growth rates: 0.17 to 0.65 d …

Siderophore-Based Microbial Adaptations To Iron Scarcity Across The Eastern Pacific Ocean, Rene M. Boiteau, Daniel R. Mende, Nicholas J. Hawco, Matthew R. Mcilvin, Jessica N. Fitzsimmons, Peter N. Sedwick

OES Faculty Publications

Nearly all iron dissolved in the ocean is complexed by strong organic ligands of unknown composition. The effect of ligand composition on microbial iron acquisition is poorly understood, but amendment experiments using model ligands show they can facilitate or impede iron uptake depending on their identity. Here we show that siderophores, organic compounds synthesized by microbes to facilitate iron uptake, are a dynamic component of the marine ligand pool in the eastern tropical Pacific Ocean. Siderophore concentrations in iron-deficient waters averaged 9 pM, up to fivefold higher than in iron-rich coastal and nutrient-depleted oligotrophic waters, and were dominated by amphibactins, …

An Alignment-Free "Metapeptide" Strategy For Metaproteomic Characterization Of Microbiome Samples Using Shotgun Metagenomic Sequencing, Damon H. May, Emma Timmins-Schiffman, Molly P. Mikan, H. Rodger Harvey, Elhanan Borenstein, Brook L. Nunn, William S. Noble

OES Faculty Publications

In principle, tandem mass spectrometry can be used to detect and quantify the peptides present in a microbiome sample, enabling functional and taxonomic insight into microbiome metabolic activity. However, the phylogenetic diversity constituting a particular microbiome is often unknown, and many of the organisms present may not have assembled genomes. In ocean microbiome samples, with particularly diverse and uncultured bacterial communities, it is difficult to construct protein databases that contain the bulk of the peptides in the sample without losing detection sensitivity due to the overwhelming number of candidate peptides for each tandem mass spectrum. We describe a method for …

The Synthesis And Characterization Of Ni(Ii) And Cu(Ii) Cyanoximates, Adedamola Abraham Opalade

Graduate Theses/Dissertations

The design of one-dimensional nickel wires were attempted. Metal complexes of hydrated Cu(II) and Ni(II) with several cyanoximates were synthesized and characterized by elemental analysis, thermal analysis, IR-, electronic- (solid state diffuse reflectance) spectroscopy, and the X-ray analysis (powder diffraction and single crystal studies). Hydrolysis of the HECO and HMeCO cyanoxime ligands leads to the formation of another dianionic cyanoxime – AACO2-, which forms multimetallic Cu(II) and Ni(II) complexes and oxamide as a side product. The crystal and molecular structures of 8 compounds were determined (6 metal complexes and 2 organic compounds). Two Ni metal complexes have distorted octahedral structures …

Systematic Errors In Intro Lab Video Analysis, John Zwart, Kayt E. Frisch, Tim Martin

Faculty Work Comprehensive List

In video analysis lab experiments, students frequently find large discrepancies between results based on self-filmed videos and expected values (e.g. for g determined by a fit to projectile motion data). These differences are frequently far larger than the uncertainty calculated from their fit. Using an inexpensive point-and-shoot camera with a 4x optical zoom to record video, we investigated two possible causes of this error: the effect of placing the reference meter stick at a different object-to-camera distance and the effect of the motion of interest being in a plane not perpendicular to the camera lens. When we observed these phenomena …

A Hierarchical Statistical Engineering Modeling Methodology, Teddy Steven Cotter

Engineering Management & Systems Engineering Faculty Publications

In the ASEM-IAC 2015, Cotter (2015) proposed a systemic joint deterministic-stochastic dynamic causal Bayesian statistical engineering model that addressed the knowledge gap needed to integrate deterministic mathematical engineering models within a stochastic framework. However, Cotter did not specify the modeling methodology through which statistical engineering models could be developed, diagnosed, and applied to predict systemic mission performance. This paper updates research into the development a hierarchical statistical engineering modeling methodology and sets forth the initial theoretical foundation for the methodology.

Valuing Natural Space And Landscape Fragmentation In Richmond, Va, Lee Wyatt Carpenter

Theses and Dissertations

Hedonic pricing methods and GIS (Geographic Information Systems) were used to evaluate relationships between sale price of single family homes and landscape fragmentation and natural land cover. Spatial regression analyses found that sale prices increase as landscapes become less fragmented and the amount of natural land cover around a home increases. The projected growth in population and employment in the Richmond, Virginia region and subsequent increases in land development and landscape fragmentation presents a challenge to sustaining intact healthy ecosystems in the Richmond region. Spatial regression analyses helped illuminate how land cover patterns influence sale prices and landscape patterns that …

Carbon Cycling In Santa Barbara Basin Sediments: A Modeling Study, David J. Burdige, Tomoko Komada, Cédric Magen, Jeffrey P. Chanton

OES Faculty Publications

The primary input of organic matter to almost all marine sediments comes from deposition at the sediment surface. However, in many continental margin settings, reduced carbon can also be added to sediments from below—for example, from “deep” geologic hydrocarbon reservoirs derived from ancient source rocks or from the decomposition of deeply buried gas hydrate deposits. To examine the impact of these two differing reduced carbon inputs on sediment biogeochemistry, a modified reaction-transport model for anoxic marine sediments is described here and applied to data from sediment cores in Santa Barbara Basin to a depth of 4.6 m. Excellent model fits …

Some Convergence Properties Of Minkowski Functionals Given By Polytopes, Jesse Moeller

Dissertations and Theses @ UNI

In this work we investigate the behavior of the Minkowski Functionals admitted by a sequence of sets which converge to the unit ball ‘from the inside’. We begin in R 2 and use this example to build intuition as we extend to the more general R n case. We prove, in the penultimate chapter, that convergence ‘from the inside’ in this setting is equivalent to two other characterizations of the convergence: a geometric characterization which has to do with the sizes of the faces of each polytope in the sequence converging to zero, and the convergence of the Minkowski functionals …

Results And Challenges In Visualizing Analytic Provenance Of Text Analysis Tasks Using Interaction Logs, Rhema Linder, Alyssa M. Peña, Sampath Jayarathna, Eric D. Ragan

Computer Science Faculty Publications

After data analysis, recalling and communicating the steps and rationale followed during the analysis can be difficult. This paper explores the use of interaction logs to generate summaries of an analyst's interest based on interactions with specific data items in a text analysis scenario. Our approach uses data-interaction events as a proxy for user interest in and experience of information. Logging can produce verbose logs that detail all available readable content, so the discussed approach uses topic modeling (LDA) over different time segments to summarize the verbose information and generate visualizations of the history of user interest. Our preliminary results …

The Effects Of Blended Learning On Critical Thinking In A High School Earth Science Class, Renee Nicole Borglum

Dissertations and Theses @ UNI

This study analyzed the effects of differing levels of technology use in a high school Earth Science class on student performance on the Classroom Test of Scientific Reasoning (CTSR). Blended learning manipulates the combination of hands-on activities, classroom discussions, online discussions, interactive simulations and a variety of assessments that engage, instruct and assess student learning. Critical thinking is the set of skills and dispositions that foster problem solving, reasoning ability and selfregulation. The increasing use of technology in the classroom and fluctuation of content standards prompted this research. The results have implications for the classroom teacher of a wide range …

Student Performance In Curricula Centered On Simulation-Based Inference: A Preliminary Report, Beth Chance, Jimmy Wong, Nathan L. Tintle

Faculty Work Comprehensive List

"Simulation-based inference"(e.g., bootstrapping and randomization tests) has been advocated recently with the goal of improving student understanding of statistical inference, as well as the statistical investigative process as a whole. Preliminary assessment data have been largely positive. This article describes the analysis of the first year of data from a multi-institution assessment effort by instructors using such an approach in a college-level introductory statistics course, some for the first time. We examine several pre-/post-measures of student attitudes and conceptual understanding of several topics in the introductory course. We highlight some patterns in the data, focusing on student level and instructor …

Anisotropic Thermodynamic And Transport Properties Of Single-Crystalline Cakfe4As4, W. R. Meier, T. Kong, U. S. Kaluarachchi, V. Taufour, N. H. Jo, G. Drachuck, A. E. Böhmer, S. M. Saunders, A. Sapkota, A. Kreyssig, M. A. Tanatar, R. Prozorov, A. I. Goldman, Fedor F. Balakirev, Alex Gurevich, S. L. Bud'ko, P. C. Canfield

Physics Faculty Publications

Single-crystalline, single-phase CaKFe₄As₄ has been grown out of a high-temperature, quaternary melt. Temperature-dependent measurements of x-ray diffraction, anisotropic electrical resistivity, elastoresistivity, thermoelectric power, Hall effect, magnetization, and specific heat, combined with field-dependent measurements of electrical resistivity and field and pressure-dependent measurements of magnetization indicate that CaKFe₄As₄ is an ordered, stoichiometric, Fe-based superconductor with a superconducting critical temperature, T_c = 35.0 ± 0.2 K. Other than superconductivity, there is no indication of any other phase transition for 1.8K ≤ T ≤ 300 K. All of these thermodynamic and transport data reveal striking similarities to …

Rapidity Evolution Of Gluon Tmd From Low To Moderate X, Ian Balitsky

Physics Faculty Publications

I discuss how the rapidity evolution of gluon transverse momentum dependent distribution changes from nonlinear evolution at small x ≪ 1 to linear evolution at moderate x ~ 1.

A Search For The Lhcb Charmed "Pentaquark" Using Photoproduction Of J/Ψ At Threshold In Hall C At Jefferson Lab, A. Asaturyan, H. Mkrtchyan, T. Tadevosyan, S. Zhamkochyan, J. Arrington, W. Armstrong, K. Hafidi, M. Hattawy, Z. Ye, K. Aniol, H. Gao, Z. Zhao, T. Liu, X. Yan, C. Gu, C. Peng, X. Li, W. Xiong, P. Markowitz, K. Adhikari, H. Bhatt, D. Bhetuwal, J. Dunne, D. Dutta, L. El-Fassi, L. Ye, F. R. Wesselmann, X. Chen, Q. Fu, R. Wang, Y. Zhang, F. Zhao, R. Dupré, G. M. Huber, W. Li, A. Zafar, S. Bae, H. Choi, S. Choi, H. Go, J. Ha, H. Atac, B. Duran, S. Joosten, Z.-E. Meziani, M. Paolone, M. Rehfuss, N. Sparveris, J.-P. Chen, E. Chudakov, M. Diefenthaler, O. Hansen, D. Higinbotham, M. Jones, D. Meekins, L. Pentchev, E. Pooser, S. Wood

Physics Faculty Publications

We propose to measure the photo-production cross section of J/Ψ near threshold in search of the recently observed LHCb hidden charm resonances Pc(4380) and Pc(4450) consistent with "pentaquarks." The observation of these resonances in photo-production is important to differentiate the true resonance nature of the LHCb states from kinematics enhancements. The bremsstrahlung photon beam produced with an 11 GeV electron beam at CEBAF enables us to cover the energy range of J/Ψ production from the threshold photo-production energy of 8.2 GeV to an energy beyond the presumed Pc(4450) resonance production. The proposed experiment will be carried out in Hall C …

Heavy Quark Production At An Electron-Ion Collider, E. Chudakov, D. Higinbotham, C. Hyde, S. Furletov, Yu Furletova, D. Nguyen, M. Stratmann, M. Strickman, C. Weiss

Physics Faculty Publications

An Electron-Ion Collider (EIC) with center-of-mass energies √seN ∼ 20-100 GeV and luminosity L ∼ 10³⁴ cm^-² s^-¹ would offer new opportunities to study heavy quark production in high-energy electron or photon scattering on protons and nuclei. We report about an R&D project exploring the feasibility of direct measurements of nuclear gluon densities at x >∼ 0.1 (gluonic EMC effect, antishadowing) using open charm production at EIC. We describe the charm production rates and angle-momentum distributions at large x and discuss methods of charm reconstruction using next-generation detector capabilities (π/K identification, vertex reconstruction). The results could be …

Probing Nuclear Gluons With Heavy Flavors At An Electron-Ion Collider, E. Chudakov, D. Higinbotham, C. Hyde, S. Furletov, Y. Furletova, D. Nguyen, M. Stratmann, M. Strikman, C. Weiss, R. Yoshida

Physics Faculty Publications

We explore the feasibility of direct measurements of nuclear gluon densities using heavy-quark production (open charm, beauty) at a future Electron-Ion Collider (EIC). We focus on the regions x> 0.3 (EMC effect) and x ~ 0.05-0.1 (antishadowing), where the nuclear modifications of the gluon density offer insight into non-nucleonic degrees of freedom and the QCD structure of nucleon-nucleon interactions. We describe the charm production rates and momentum distributions in nuclear deep-inelastic scattering (DIS) at Large XB, and comment on the possible methods for charm reconstruction using next-generation detectors at the EIC (π/K identification, tracking, vertex detection).

Relating Transverse-Momentum-Dependent And Collinear Factorization Theorems In A Generalized Formalism, J. Collins, L. Gamberg, A. Prokudin, T. C. Rogers, N. Sato, B. Wang

Physics Faculty Publications

We construct an improved implementation for combining transverse-momentum-dependent (TMD) factorization and collinear factorization. TMD factorization is suitable for low transverse momentum physics, while collinear factorization is suitable for high transverse momenta and for a cross section integrated over transverse momentum. The result is a modified version of the standard 𝑊 + 𝑌 prescription traditionally used in the Collins-Soper-Sterman (CSS) formalism and related approaches. We further argue that questions regarding the shape and 𝑄 dependence of the cross sections at lower 𝑄 are largely governed by the matching to the 𝑌 term.

Studies Of Light Nuclei In Χeft: A Status Report, R. Schiavilla

Physics Faculty Publications

A status report on χEFT studies of few-nucleon electroweak structure and dynamics is provided, including electromagnetic form factors of few nucleon systems, the pp weak fusion and muon weak captures on deuteron and ³He, an a number of parity-violating processes induced by hadronic weak interactions

A Usability And Learnability Case Study Of Glass Flight Deck Interfaces And Pilot Interactions Through Scenario-Based Training, Thomas James De Cino

CCAC Theses and Dissertations

In the aviation industry, digitally produced and presented flight, navigation, and aircraft information is commonly referred to as glass flight decks. Glass flight decks are driven by computer-based subsystems and have long been a part of military and commercial aviation sectors. Over the past 15 years, the General Aviation (GA) sector of the aviation industry has become a recent beneficiary of the rapid advancement of computer-based glass flight deck (GFD) systems.

While providing the GA pilot considerable enhancements in the quality of information about the status and operations of the aircraft, training pilots on the use of glass flight decks …

Blended Learning For Faculty Professional Development Incorporating Knowledge Management Principles, Julie E. Hewitt

CCAC Theses and Dissertations

Adjunct faculty comprise a large percentage of part-time faculty for many colleges and universities today. Adjunct faculty are hired because they are experts in their content areas; however, this does not guarantee that they are skilled in effective classroom management. These instructors can become bewildered and frustrated because they lack the knowledge and skills that are needed to run an effective classroom.

While educational organizations have adopted blended learning environments as an effective delivery method for their students, this method has not gained much traction as a way to deliver instruction to their own employees. Thus, there are opportunities to …

An Empirical Assessment Of Employee Cyberslacking In The Public Sector, Wilnelia Hernández

CCAC Theses and Dissertations

With the increasing use of the Internet, new challenges are presented to employees in the workplace. Employees spend time during work hours on non-work related activities including visiting e-commerce Websites, managing personal email accounts, and engaging in e-banking. These types of actions in the workplace are known as cyberslacking. Cyberslacking affects the employees’ productivity, presents legal concerns, and undermines the security of the organization’s network. This research study addressed the problem of cyberslacking in the public sector, by assessing the ethical severity of cyberslacking activities, as well as how employees perceived that the frequency of such activities occurred by their …

Automatically Defined Templates For Improved Prediction Of Non-Stationary, Nonlinear Time Series In Genetic Programming, David Moskowitz

CCAC Theses and Dissertations

Soft methods of artificial intelligence are often used in the prediction of non-deterministic time series that cannot be modeled using standard econometric methods. These series, such as occur in finance, often undergo changes to their underlying data generation process resulting in inaccurate approximations or requiring additional human judgment and input in the process, hindering the potential for automated solutions.

Genetic programming (GP) is a class of nature-inspired algorithms that aims to evolve a population of computer programs to solve a target problem. GP has been applied to time series prediction in finance and other domains. However, most GP-based approaches to …

Mutable Class Design Pattern, Nikolay Malitsky

CCAC Theses and Dissertations

The dissertation proposes, presents and analyzes a new design pattern, the Mutable Class pattern, to support the processing of large-scale heterogeneous data models with multiple families of algorithms. Handling data-algorithm associations represents an important topic across a variety of application domains. As a result, it has been addressed by multiple approaches, including the Visitor pattern and the aspect-oriented programming (AOP) paradigm. Existing solutions, however, bring additional constraints and issues. For example, the Visitor pattern freezes the class hierarchies of application models and the AOP-based projects, such as Spring AOP, introduce significant overhead for processing large-scale models with fine-grain objects. The …

An Experimental Study On The Role Of Password Strength And Cognitive Load On Employee Productivity, Stephen Mujeye

CCAC Theses and Dissertations

The proliferation of information systems (IS) over the past decades has increased the demand for system authentication. While the majority of system authentications are password-based, it is well documented that passwords have significant limitations. To address this issue, companies have been placing increased requirements on the user to ensure their passwords are more complex and consequently stronger. In addition to meeting a certain complexity threshold, the password must also be changed on a regular basis. As the cognitive load increases on the employees using complex passwords and changing them often, they may have difficulty recalling their passwords. As such, the …

An Investigation Of Socio-Technical Components Of Knowledge Management System (Kms) Usage, Noel Wint Jr.

CCAC Theses and Dissertations

Existing literature indicates that although both academics and practitioners recognize knowledge management (KM) as a source of competitive advantage, users are not always willing to use a knowledge management system (KMS). Because of the social nature of knowledge transfer, a KMS can be considered a socio-technical system. Many explanations have been presented for this failure to utilize the KMS. These explanations include a number of the socio-technical factors relating to people, processes, and technologies. While these factors may have significant explanatory power when examined independently, existing studies have not sufficiently addressed the interactions among all three socio-technical factors or their …

Evaluation Of Supervised Machine Learning For Classifying Video Traffic, Farrell R. Taylor

CCAC Theses and Dissertations

Operational deployment of machine learning based classifiers in real-world networks has become an important area of research to support automated real-time quality of service decisions by Internet service providers (ISPs) and more generally, network administrators. As the Internet has evolved, multimedia applications, such as voice over Internet protocol (VoIP), gaming, and video streaming, have become commonplace. These traffic types are sensitive to network perturbations, e.g. jitter and delay. Automated quality of service (QoS) capabilities offer a degree of relief by prioritizing network traffic without human intervention; however, they rely on the integration of real-time traffic classification to identify applications. Accordingly, …

The Effects Of Time-Compression And Learner-Control In Multimedia Instruction, Jason Alan Pittman

CCAC Theses and Dissertations

There is a significant gap in the body of knowledge concerning time-compressed multimedia instruction. Although research indicates that there is no loss in learning through well-designed multimedia instruction compressed at 25%, research is lacking that analyzes the effects of time-compression with learner-control included in the multimedia instruction. The aim of the study was to address this gap in the research by integrating learner-control into the interface of a time-compressed multimedia instructional lesson using similar methodologies from previous research.

Effects were analyzed of time-compressed learner-controlled multimedia instruction on learning and perceived cognitive load. Additionally, the researcher employed a participant population from …