Digital Commons Network^™

Interval Graphs, Joyce C. Yang

HMC Senior Theses

We examine the problem of counting interval graphs. We answer the question posed by Hanlon, of whether the formal power series generating function of the number of interval graphs on n vertices has a positive radius of convergence. We have found that it is zero. We have obtained a lower bound and an upper bound on the number of interval graphs on n vertices. We also study the application of interval graphs to the dynamic storage allocation problem. Dynamic storage allocation has been shown to be NP-complete by Stockmeyer. Coloring interval graphs on-line has applications to dynamic storage allocation. The …

Hopper Bands: Locust Aggregation, Ryan C. Jones

HMC Senior Theses

Locust swarms cause famine and hunger in parts of Sub-Saharan Africa as they travel across croplands and eat vegetation. Current models start with biological properties of locusts and analyze the macroscopic behavior of the system. These models exhibit the desired migratory behavior, but do so with too many parameters. To account for this, a new model, the Alignment and Intermittent Motion (AIM) model, is derived with minimal assumptions. AIM is constructed with regards to locust biology, allowing it to elicit biologically correct locust behavior: the most noteworthy being the fingering of hopper bands. A Particle-in-Cell method is used to optimize …

Differences In Rhodococcus Equi Infections Based On Immune Status And Antibiotic Susceptibility Of Clinical Isolates In A Case Series Of 12 Patients And Cases In The Literature, Praveen Gundelly, Yasuhiro Suzuki, Julie A. Ribes, Alice C. Thornton

Internal Medicine Faculty Publications

Rhodococcus equi is an unusual zoonotic pathogen that can cause life-threatening diseases in susceptible hosts. Twelve patients with R. equi infection in Kentucky were compared to 137 cases reported in the literature. Although lungs were the primary sites of infection in immunocompromised patients, extrapulmonary involvement only was more common in immunocompetent patients (P > 0.0001). Mortality in R. equi-infected HIV patients was lower in the HAART era (8%) than in pre-HAART era (56%) (P > 0.0001), suggesting that HAART improves prognosis in these patients. Most (85–100%) of clinical isolates were susceptible to vancomycin, clarithromycin, rifampin, aminoglycosides, ciprofloxacin, and imipenem. …

The Role Of Renal Replacement Therapy In The Management Of Pharmacologic Poisonings, Aibek E. Mirrakhimov, Aram Barbaryan, Adam Gray, Taha Ayach

Internal Medicine Faculty Publications

Pharmacologic toxicities are common and range from mild to life-threatening. The aim of this study is to review and update the data on the role of renal replacement therapy (RRT) in the management of various pharmacologic poisonings. We aim to provide a focused review on the role of RRT in the management of pharmacological toxicities. Relevant publications were searched in MEDLINE with the following search terms alone or in combination: pharmacologic toxicity, hemodialysis, hemofiltration, renal replacement therapy, toxicology, poisonings, critical illness, and intensive care. The studies showed that a pharmacologic substance should meet several prerequisites to be deemed dialyzable. These …

Prediction Of Metal Remobilization From Sediments Under Various Physical/ Chemical Conditions “Design Of Experiments Cd, Co And Pb”, Eid A. Alkhatib, Trey Chabot, Danielle Grunzke

Chemistry & Physics Faculty Publications

The metal partition coefficient Kd (L/kg) is the ratio of sorbed metal concentration on the solid phase m (mg/kg) to the dissolved metal concentration at equilibrium. The behavior of metals in surface water is complex and their partition coefficients can be impacted by many factors. Organic matter (OM) content in sediments, pH and salinity, are factors that may influence speciation and partitioning of metals. In this study, the partitioning coefficient of three metals (Cd, Co and Pb) under different levels of salinity, pH, and OM content were examined. A series of factorial experiments were evaluated in which three levels of …

Emerson On Plato: Literary Philosophy, Dialectic, And The Temporality Of Thought, Jesse I. Bailey

Philosophy, Theology and Religious Studies Faculty Publications

For Emerson, Plato is the quintessential philosopher. I will argue that, to the extent that Emerson wanted his essays to have philosophical depth, he considered his work to be an extension of the work found in Plato’s dialogues.

Temporal Trends And Spatial Variabilities Of Pcb Concentrations In Lake Trout From Lake Superior From 1995 To 2013, Hongyi Lin

Dissertations, Master's Theses and Master's Reports

It has been frequently reported that concentrations of PCBs in the Great Lakes fish have declined dramatically since their ban on production and use in 1979 in the United States, although some studies suggested that recent rates of decline are leveling off. In order to examine the temporal trends and spatial variabilities of PCB concentrations in lake trout (Salvelinus namaycush) from Lake Superior during the past two decades, statistical analyses were performed on fish sample data collected by two national agencies (U.S. EPA, Environment and Climate Change Canada) and three state agencies (Michigan Department of Environmental Quality, Minnesota …

Predictive Control Of Power Grid-Connected Energy Systems Based On Energy And Exergy Metrics, Meysam Razmara

Dissertations, Master's Theses and Master's Reports

Building and transportation sectors account for 41% and 27% of total energy consumption in the US, respectively. Designing smart controllers for Heating, Ventilation and Air-Conditioning (HVAC) systems and Internal Combustion Engines (ICEs) can play a key role in reducing energy consumption. Exergy or availability is based on the First and Second Laws of Thermodynamics and is a more precise metric to evaluate energy systems including HVAC and ICE systems. This dissertation centers on development of exergy models and design of model-based controllers based on exergy and energy metrics for grid-connected energy systems including HVAC and ICEs.

In this PhD dissertation, …

Promoting Metacognitive Reflection In Music Theory Instruction, Anna Ferenc

Journal of Music Theory Pedagogy

Since 1976 when John Flavell coined the term metacognition, a significant body of literature has emerged in psychology and education research documenting the importance of it to the process of learning and advocating its development through reflection to promote deeper, more thoughtful, and self-regulated learning. In the domain of music, discussions of reflection and/or metacognition appear particularly in literature on teacher training, music teaching at primary and secondary levels, and performance, but these topics are hardly addressed in research on music theory pedagogy. This article begins to redress this situation. It presents a theoretical overview of metacognition and reflection, describes …

Spring/Summer 2016

University of Richmond Magazine

No abstract provided.

2016 Diversity Climate Survey, Illinois Mathematics And Science Academy

Diversity, Equity, and Inclusion: Resources

A survey about diversity and school climate, based off of the National Climate Survey used by the Gay, Lesbian and Straight Education Network (GLSEN), was distributed to students electronically in 2015. In all, 536 students took the survey. Those who did not finish the survey (29 students), or who marked all possible choices for sexual orientation or gender (implying inauthentic responses, 7 students) were removed from the sample. This report covers some of the major results from the study.

Effects Of Mountaintop Removal Mining On Population Dynamics Of Stream Salamanders, Sara B. Freytag

Theses and Dissertations--Forestry and Natural Resources

Mountaintop removal mining (MTR) is a notorious stressor of stream ecosystems in the Central Appalachians. Valley fills (VF) lead to reduced occupancy, abundance, and species richness of stream salamanders. Multiple factors may be responsible for these reductions, but specifically habitat fragmentation and degradation may reduce colonization rates and increase local extinction rates. From 2013-2015, repeated counts of salamanders were conducted in stream reaches impacted by MTR/VF and compared to counts in reference reaches to answer the question: do stream salamander population dynamics differ between stream reaches impacted by MTR/VF and reference stream reaches? I also investigated dynamics of stream habitat …

Automated Solid-Substrate Cultivation Of The Anaerobic Bacterium Clostridium Thermocellum, Mathew J. Ruwaya

Theses and Dissertations--Biosystems and Agricultural Engineering

The organism Clostridium thermocellum grows on cellulosic substrates and produces ethanol, acetate, lactate, formic acid, and CO₂. The organic acids produced alter the growth environment in which the bacteria grows and ultimately inhibit bacterial growth. One method which has been used successfully to maintain the system at acceptable growth conditions is to intermittently flush out the spent media and metabolic products and replace with new fermentation media. Our goal was to design and build an automated system that will automatically flush the spent media from the growing culture and resupply new media without manual intervention. An automated control …

Separator Reconnection At The Magnetopause For Predominantly Northward And Southward Imf: Techniques And Results, A. Glocer, J. Dorelli, G. Toth, C. M. Komar, P. A. Cassak

Faculty & Staff Scholarship

In this work, we demonstrate how to track magnetic separators in three-dimensional simulated magnetic fields with or without magnetic nulls, apply these techniques to enhance our understanding of reconnection at the magnetopause. We present three methods for locating magnetic separators and apply them to 3-D resistive MHD simulations of the Earth's magnetosphere using the Block-Adaptive-Tree Solar-wind Roe-type Upwind Scheme code. The techniques for finding separators and determining the reconnection rate are insensitive to interplanetary magnetic field (IMF) clock angle and can in principle be applied to any magnetospheric model. Moreover, the techniques have a number of advantages over prior separator …

Writing About Shakespeare: 1960–2010, Dominic Klyve, Laura Estill

Mathematics Faculty Scholarship

This dataset quantifi es writing (in number of articles, books, dissertations, and monographs) about each of Shakespeare’s plays during each year in the period 1960–2010. The information was extracted from the World Shakespeare Bibliography (www.worldshakesbib.org).

The Bourgain Spaces And Recovery Of Magnetic And Electric Potentials Of Schrödinger Operators, Yaowei Zhang

Theses and Dissertations--Mathematics

We consider the inverse problem for the magnetic Schrödinger operator with the assumption that the magnetic potential is in C^λ and the electric potential is of the form p₁ + div p₂ with p₁, p₂ ∈ C^λ. We use semiclassical pseudodifferential operators on semiclassical Sobolev spaces and Bourgain type spaces. The Bourgain type spaces are defined using the symbol of the operator h²Δ + hμ ⋅ D. Our main result gives a procedure for recovering the curl of the magnetic field and the electric potential from the Dirichlet to Neumann …

Who Has The Final Word In Assessing Language Teacher Readiness?: Corporate Standardization Versus Local Expertise, Susan A. Hildebrandt

Faculty Publications – Languages, Literatures, and Cultures

No abstract provided.

Contact Improvisation: Concepts Of Physics Transformed Into Art, Gianna F. Todisco

Dance Department Best Student Papers

No abstract provided.

Efficient Image Processing Via Compressive Sensing Of Integrate-And-Fire Neuronal Network Dynamics, Victor J. Barranca, G. Kovačič, D. Zhou, D. Cai

Mathematics & Statistics Faculty Works

Integrate-and-fire (I&F) neuronal networks are ubiquitous in diverse image processing applications, including image segmentation and visual perception. While conventional I&F network image processing requires the number of nodes composing the network to be equal to the number of image pixels driving the network, we determine whether I&F dynamics can accurately transmit image information when there are significantly fewer nodes than network input-signal components. Although compressive sensing (CS) theory facilitates the recovery of images using very few samples through linear signal processing, it does not address whether similar signal recovery techniques facilitate reconstructions through measurement of the nonlinear dynamics of an …

Grief And Gratitude, Lynne Steuerle Schofield

Mathematics & Statistics Faculty Works

No abstract provided.

A Cross-Linguistic Preference For Torso Stability In The Lexicon: Evidence From 24 Sign Languages, N. Sanders, Donna Jo Napoli

Linguistics Faculty Works

When the arms move in certain ways, they can cause the torso to twist or rock. Such extraneous torso movement is undesirable, especially during sign language communication, when torso position may carry linguistic significance, so we expend effort to resist it when it is not intended. This so-called “reactive effort” has only recently been identified by Sanders and Napoli (2016), but their preliminary work on three genetically unrelated languages suggests that the effects of reactive effort can be observed cross-linguistically by examination of sign language lexicons. In particular, the frequency of different kinds of manual movements in the lexicon correlates …

Choline Diet And Its Gut Microbe–Derived Metabolite, Trimethylamine N-Oxide, Exacerbate Pressure Overload–Induced Heart Failure, Chelsea L. Organ, Hiroyuki Otsuka, Shashi Bhushan, Zeneng Wang, Jessica Bradley, Rishi Trivedi, David J. Polhemus, W.H. Wilson Tang, Yuping Wu, Stanley L. Hazen, David J. Lefer

Mathematics and Statistics Faculty Publications

Background—Trimethylamine N-oxide (TMAO), a gut microbe–dependent metabolite of dietary choline and other trimethylamine-containing nutrients, is both elevated in the circulation of patients having heart failure and heralds worse overall prognosis. In animal studies, dietary choline or TMAO significantly accelerates atherosclerotic lesion development in ApoE-deficient mice, and reduction in TMAO levels inhibits atherosclerosis development in the low-density lipoprotein receptor knockout mouse. Methods and Results—C57BL6/J mice were fed either a control diet, a diet containing choline (1.2%) or a diet containing TMAO (0.12%) starting 3 weeks before surgical transverse aortic constriction. Mice were studied for 12 weeks after transverse aortic constriction. Cardiac …

Elevated Soluble Fms-Like Tyrosine Kinase-1 And Placental-Like Growth Factor Levels Are Associated With Development And Mortality Risk In Heart Failure, Muhammad Hammadah, Vasiliki V. Georgiopoulou, Andreas P. Kalogeropoulos, Malory Weber, Xi Wang, Michael A. Samara, Yuping Wu, Javed Butler, W.H. Wilson Tang

Mathematics and Statistics Faculty Publications

Background—Vascular endothelial dysfunction may play an important role in the progression of heart failure (HF). We hypothesize that elevated levels of vascular markers, placental-like growth factor, and soluble Fms-like tyrosine kinase-1 (sFlt-1) are associated with adverse outcomes in patients with HF. We also assessed possible triggers of sFlt-1 elevation in animal HF models. Methods and Results—We measured plasma placental-like growth factor and sFlt-1 in 791 HF patients undergoing elective coronary angiogram. Median (interquartile range) placental-like growth factor and sFlt-1 levels were 24 (20–29) and 382 (277–953) pg/mL, respectively. After 5 years of follow-up, and after using receiver operator characteristic curves …

Modeling Cross-Contamination During Poultry Processing: Dynamics In The Chiller Tank, Daniel Munther, Xiaodan Sun, Yanni Xiao, Sanyi Tang, Helio Shimozako, Jianhong Wu, Ben A. Smith, Aamir Fazil

Mathematics and Statistics Faculty Publications

Understanding mechanisms of cross-contamination during poultry processing is vital for effective pathogen control. As an initial step toward this goal, we develop a mathematical model of the chilling process in a typical high speed Canadian processing plant. An important attribute of our model is that it provides quantifiable links between processing control parameters and microbial levels, simplifying the complexity of these relationships for implementation into risk assessment models. We apply our model to generic, non-pathogenic Escherichia coli contamination on broiler carcasses, connecting microbial control with chlorine sanitization, organic load in the water, and pre-chiller E. coli levels on broiler carcasses. …

Prognostic Value Of Baseline And Changes In Circulating Soluble St2 Levels And The Effects Of Nesiritide In Acute Decompensated Heart Failure, W.H. Wilson Tang, Yuping Wu, Justin L. Grodin, Amy P. Hsu, Adrian F. Hernandez, Javed Butler, Marco Metra, Adriaan A. Voors, Michael G. Felker, Richard W. Troughton, Roger M. Mills, John J. Mcmurray, Paul W. Armstrong, Christopher M. O'Connor, Randall C. Starling

Mathematics and Statistics Faculty Publications

Objectives: The study sought to investigate the association between soluble growth stimulation expressed gene 2 (sST2) level and adverse outcomes in acute heart failure (HF). Background: Several studies have demonstrated the prognostic utility of sST2 levels in HF.Methods: sST2 levels were measured in sequential baseline and follow-up (48 to 72 h and 30 days) plasma samples from 858 acute HF subjects enrolled in the ASCEND-HF (Acute Study of Clinical Effectiveness of Nesiritide in Decompensated Heart Failure) trial biomarker substudy and were related to in-hospital and post-discharge clinical outcomes. Results: Higher sST2 levels were associated with increased death risk at 180 …

Curvature-Driven Foam Coarsening On A Sphere: A Computer Simulation, Shawn D. Ryan, Xiaoyu Zheng, Peter Palffy-Muhoray

Mathematics and Statistics Faculty Publications

The von Neumann-Mullins law for the area evolution of a cell in the plane describes how a dry foam coarsens in time. Recent theory and experiment suggest that the dynamics are different on the surface of a three-dimensional object such as a sphere. This work considers the dynamics of dry foams on the surface of a sphere. Starting from first principles, we use computer simulation to show that curvature-driven motion of the cell boundaries leads to exponential growth and decay of the areas of cells, in contrast to the planar case where the growth is linear. We describe the evolution …

Unraveling The Dose-Response Puzzle Of L. Monocytogenes: A Mechanistic Approach, S. M.Ashrafur Rahman, Daniel Munther, Aamir Fazil, Ben Smith, Jianhong Wu

Mathematics and Statistics Faculty Publications

Food-borne disease outbreaks caused by Listeria monocytogenes continue to impose heavy burdens on public health in North America and globally. To explore the threat L. monocytogenes presents to the elderly, pregnant woman and immuno-compromised individuals, many studies have focused on in-host infection mechanisms and risk evaluation in terms of dose-response outcomes. However, the connection of these two foci has received little attention, leaving risk prediction with an insufficient mechanistic basis. Consequently, there is a critical need to quantifiably link in-host infection pathways with the dose-response paradigm. To better understand these relationships, we propose a new mathematical model to describe the …

Delaying Child Marriage Through Community-Based Skills-Development Programs For Girls: Results From A Randomized Controlled Study In Rural Bangladesh, Sajeda Amin, Johana Ahmed, Jyotirmoy Saha, Md. Irfan Hossain, Eashita Haque

Poverty, Gender, and Youth

In Bangladesh, where efforts to prevent child marriage have focused on the enforcement of laws and policies, little research exists on what approaches work best to delay marriage and why. To help fill this evidence gap, in 2012 the Population Council and partners embarked on a four-year study to understand whether skills-building approaches to empower girls can delay marriage in three districts in southern Bangladesh where child marriage rates are high. The BALIKA project reported here is the first rigorously evaluated study to provide evidence on approaches to delay child marriage in Bangladesh. BALIKA results show that programs that educate …

Mathematics Learning Support Across A Multi-Campus Institution: A Prototype Of Virtual Support, Cormac Breen, Ciaran O'Sullivan, Damian Cox

Articles

In this paper, a study on Mathematics Learning Support (MLS) that was undertaken across three institutes intending to form the Technological University for Dublin is outlined. This study consisted of a survey that was circulated to both staff and students in each of the three institutes. The survey had two objectives. Firstly it sought to identify the students’ needs for MLS in each of the three institutes. Secondly, it sought to ascertain the preferred method of provision of MLS, on a scale ranging from exclusively online, to exclusively in person. Following on the results of this survey it was decided …

Development Of Advanced, Clinically Feasible Neuroimaging Methodology With Diffusional Kurtosis Imaging, G. Russell Glenn

MUSC Theses and Dissertations

Diffusion MRI (dMRI) is a powerful, non-invasive tool for probing the structural organization of the human brain. Quantitative dMRI analyses provide unique capabilities for the characterization of tissue microstructure as well as imaging contrast that is not available to other modalities. White matter tractography relies on dMRI and is currently the only non-invasive technique for mapping structural connections in the human brain. In this chapter, we will describe diffusional kurtosis imaging, an effective and versatile dMRI technique, and discuss a clinical problem in temporal lobe epilepsy (TLE) which is insurmountable with current diagnostic approaches. Subsequent chapters will further develop the …