Physical Sciences and Mathematics Commons^™

The Classification Of Basket Neural Cells In The Mammalian Neocortex, Sreya Pudi

Senior Theses

Basket neuronal cells of the mammalian neocortex have been classically categorized into two or more groups. Originally, it was thought that the large and small types are the naturally occurring groups that emerge from reasons that relate to neurobiological function and anatomical position. Later, a study based on anatomical and physiological features of these neurons introduced a third type, the net basket cell which is intermediate in size as compared to the large and small types. In this study, multivariate analysis was used to test the hypothesis that the large and small types are morphologically distinct groups. The results of …

Sampling And Robustness In Multi-Robot Visibility-Based Pursuit-Evasion, Trevor Vincent Olsen

Theses and Dissertations

Given a two-dimensional polygonal space, the multi-robot visibility-based pursuit-evasion problem tasks several pursuer robots with the goal of establishing visibility with an arbitrarily fast evader. The best-known complete algorithm for this problem takes time doubly exponential in the number of robots. However, sampling-based techniques have shown promise in generating feasible solutions in these scenarios.

Existing sampling-based algorithms have long execution times and high failure rates for complex environments. We first address that limitation by proposing a new algorithm that takes an environment as its input and returns a joint motion strategy which ensures that the evader is captured by one …

Crest Or Trough? How Research Libraries Used Emerging Technologies To Survive The Pandemic, So Far, Scout Calvert

UNL Libraries: Faculty Publications

Introduction

In the first months of the COVID-19 pandemic, it was impossible to tell if we were at the crest of a wave of new transmissions, or a trough of a much larger wave, still yet to peak. As of this writing, as colleges and universities prepare for mostly in-person fall 2021 semesters, case counts in the United States are increasing again after a decline that coincided with easier access to the COVID vaccine. Plans for a return to campus made with confidence this spring may be in doubt, as we climb the curve of what is already the second …

Bird Diversity In The Ecuadorian Chocó: A Proposal For Avitourism In Villaflora And Manduriacu Reserve, Elizabeth Kroger

Independent Study Project (ISP) Collection

Ecuador is rich in avifauna, and the Chocó bioregion of Northwestern Ecuador is a hotspot for bird endemism and diversity. However, many rare and beautiful species are threatened by human activities such as logging and mining. It is essential that communities are able to find alternative solutions that bring economic benefits and improve public health. Avitourism is an economically beneficial and environmentally friendly solution. This study examined avifaunal biodiversity in Villaflora and Manduriacu Reserve, a small town in the cloud forest of the Chocó region. Point counts on pre-existing trails were used to assess bird communities as well as search …

Retrato De Una Economía En Movimiento: Retos De La Economía Sustentable En San Francisco De Borja, Quijos, Napo, Meghan Mary Edwards

Independent Study Project (ISP) Collection

Esta monografía presenta la situación económica actual en el Valle Quijos, en la parte occidental de la provincia de Napo, Ecuador. La mayoría de los residentes son gente campesina, que se dedica a la ganadería y la lechería. Se encuentran en la zona de amortiguamiento de dos parques nacionales, y mientras la población está creciendo, la gente tiene cada vez menos espacio entre las áreas protegidas, que ha generado conflictos sociales y conflictos ambientales, que incluyen la deforestación, la caza ilegal, y la erosión de las áreas pendientes. La monografía investiga el turismo y la ganadería tecnificada como algunos posibles …

Infinitely Many Radial Solutions For A P-Laplacian Problem With Indefinite Weight, Alfonso Castro, Jorge Cossio, Sigifredo Herrón, Carlos Vélez

All HMC Faculty Publications and Research

We prove the existence of infinitely many sign changing radial solutions for a p-Laplacian Dirichlet problem in a ball. Our problem involves a weight function that is positive at the center of the unit ball and negative in its boundary. Standard initial value problems-phase plane analysis arguments do not apply here because solutions to the corresponding initial value problem may blow up near the boundary due to the fact that our weight function is negative at the boundary. We overcome this difficulty by connecting the solutions to a singular initial value problem with those of a regular initial value problem …

A Neural Network Ensemble Approach To System Identification, Elisa Negrini, Giovanna Citti, Luca Capogna

Mathematics Sciences: Faculty Publications

We present a new algorithm for learning unknown governing equations from trajectory data, using and ensemble of neural networks. Given samples of solutions x(t) to an unknown dynamical system x˙(t) = f(t, x(t)), we approximate the function f using an ensemble of neural networks. We express the equation in integral form and use Euler method to predict the solution at every successive time step using at each iteration a different neural network as a prior for f. This procedure yields M-1 time-independent networks, where M is the number of time steps at which x(t) is observed. Finally, we obtain a …

Enhancing The Weather: Governance Of Weather Modification Activities Of The United States, Manon Simon

William & Mary Environmental Law and Policy Review

In the context of climate change, weather modification by cloud seeding, and in particular, precipitation enhancement techniques, has gained a renewed attention from governments. In the United States, several states run weather modification programs to secure freshwater resources and increase both crop and hydroelectricity production. Weather modification techniques were developed post–World War II, and so were the legal arrangements that govern them. Since then, weather modification law has undergone little to no reform. California and Texas are two active users of cloud-seeding technologies but employ very different governance frameworks. This Article assesses the effectiveness of weather modification governance in these …

Thin Safety Margin: The Sefor Super-Prompt-Critical Transient Experiments, Ozark Mountains, Arkansas 1970–1971, Jerry Havens, Collis Geren

Arkansas Scholarly Editions

Thin Safety Margin charts the history of SEFOR, a twenty-megawatt reactor that operated for three years in the rural Ozark Mountains of Arkansas as part of an internationally sponsored program designed to demonstrate the Doppler effect in plutonium-oxide-fueled fast reactors. Authors Jerry Havens and Collis Geren draw upon this history to assess the accidental explosion risk inherent in using fast reactors to reduce the energy industry’s carbon dioxide emissions.

If a sufficiently powerful fast-neutron explosion were to cause the containment of a reactor such as SEFOR’s to fail, the reactor’s radiotoxic plutonium fuel could vaporize and escape into the surrounding …

Calibration Of Gas Flow Meters Using Choked Flow And An Evacuated Vessel, Max B. Trueblood, Otmar Schmid, Nicholas Altese, Christian J. Hurst, Wenyan Liu, Teresa Gelles, Steven C. Achterberg, Philip D. Whitefield, Donald E. Hagen

Chemistry Faculty Research & Creative Works

The measurement of gas flow rates is of great importance in a wide range of modern technologies. This paper introduces a simple, yet accurate technique for in-house calibration of gas FMs (mass and volumetric) even under harsh environmental conditions such as encountered during field measurement campaigns. The method requires only readily available, low cost components: a vessel of known volume, an air pump, a pressure sensor and a metal plate orifice or a needle valve to act as a CO. The unique property of choked flow in the CO is used here for flow calibration. In the method presented here …

Experimental Data On Water Soluble Polymers Thermal And Hydrolytic Stability, Reactivity Ratios Of Monomers And Frr Calculation For Thermally Stable Preformed Particle Gels Therefrom, Buddhabhushan Salunkhe, Thomas P. Schuman, Ali Al Brahim, Baojun Bai

Chemistry Faculty Research & Creative Works

Experimental data on water soluble polymer thermal and hydrolytic stability in acidic, neutral and basic pH conditions in aqueous solution is presented. Thermal and hydrolytic stability of polymer aqueous solutions were monitored in variable pH medium by aging at 130 °C temperature for different aging time. Polymer viscosity measurements were performed periodically for 3 months. Furthermore, this data can serve as a basis of monomer selection for thermally stable hydrogels for applications like oil recovery, hydrogel coatings for steam sterilized medical devices and other applications. Reactivity ratios were determined for monomers associated to the most stable polymers using ¹H …

Preparation And Pharmacokinetic Characterization Of An Anti-Virulence Compound Nanosuspensions, Nan Wang, Feng Qi, Xiaolong He, Honglan Shi, David W. Anderson, Hao Li, Hongmin Sun

Chemistry Faculty Research & Creative Works

Antibiotic resistance has become a worldwide public health threat due to the rapid evolu-tion and spread of antibiotic-resistant bacteria. CCG-211790 is a novel anti-virulence compound that does not kill bacteria but could ameliorate human diseases by inhibiting expression of virulence factors, thereby applying less selection pressure for antibiotic resistance. However, its potential clinical use is restricted because of its poor aqueous solubility, resulting in formulation challenges. Nanosuspension technology is an effective way to circumvent this problem. Nanosuspensions of CCG-211790 with two different particle sizes, NanoA (315 ± 6 nm) and NanoB (915 ± 24 nm), were prepared using an antisolvent …

Approaches For Eye-Tracking While Reading, Xiaohao Sun

Electronic Theses and Dissertations

In this thesis, we developed an algorithm to detect the correct line being read by participants. The comparisons of the reading line classification algorithms are demonstrated using eye-tracking data collected from a realistic reading experiment in front of a low-cost desktop-mounted eye-tracker. With the development of eye-tracking techniques, research begins to aim at trying to understand information from the eyes. However, state of the art in eye-tracking applications is affected by a large amount of measurement noise. Even the expensive eye-trackers still suffer significant noise. In addition, the inherent characteristics of gaze movement increase the difficulty of obtaining valuable information …

Tracking Induced Seismicity In The Fort Worth Basin, Texas And Northern Oklahoma Using Local And Large-N Style Arrays, Louis Quinones

Earth Sciences Theses and Dissertations

Since 2008, earthquake sequences within the Fort Worth Basin (FWB), north Texas, have been linked to wastewater disposal activities related to unconventional shale gas production. Here, I present my work analyzing and cataloging a complete record of the seismicity occurring within the basin over a period of more than a decade (2008-2020). Analysis of the catalog reveals that the earthquakes generally occur within the Precambrian basement along steeply dipping normal faults, and while overall seismicity rates have decreased since 2016, new faults have become active. I observe strong spatial and temporal correlations between the earthquake locations and wastewater disposal well …

Solar Cell Brdf Measurement And Modeling With Out-Of-Plane Data, Todd V. Small, Samuel D. Butler, Michael A. Marciniak

Faculty Publications

In this work, a CCD-augmented complete angle scatter instrument (CASI) with a visible red laser source was used to measure the BRDF of a commercially available solar cell designed for small satellites, simultaneously capturing both in-plane and out-of-plane data with high angular resolution surrounding the specular direction. The measurements exhibited three distinct scatter features: a central specular peak, an offset specular peak, and a diffraction pattern. The two peaks were caused by different material surfaces with slightly different normal directions, and the diffraction pattern arose from periodically-spaced metal conducting bars running in one direction across the solar cell surface. The …

Oxygen-Induced Surface Reconstructions On Curved Ag(111), Marie Turano, Ludo B. F. Juurlink, Maxwell Z. Gillum, Elizabeth A. Jamka, George Hildebrandt, Faith J. Lewis, Daniel Killelea

Chemistry: Faculty Publications and Other Works

The adsorption of oxygen and the resultant O-induced surface reconstructions are key components in heterogeneously catalyzed reactions on silver metal surfaces. O uptake and reconstructions on planar Ag(111) are well-characterized, and in this paper, we show that curved Ag(111) features similar O adsorption and reconstructions. Through a systematic scanning tunneling microscope study of a curved Ag(111) single crystal exposed to gas-phase atomic oxygen at a temperature of 525 K, we observed Oad and, upon higher coverages, saw p(4 4) and p(4 5 p3) reconstructions form on both the A-type and B-type steps. Exposures at low temperatures (< 500 K) resulted in the formation of subsurface oxygen and the appearance of a stripe pattern and amorphous phase on the surface. Upon heating, stable surface reconstructions were formed. Although the geometric arrangement of atoms along the steps were different, A-type and B-type steps formed the same reconstructions. In addition, the B-type steps also saw the formation of several different features atop the oxygen reconstructions.

Influence Of Salinity On Sav Distribution In A Series Of Intermittently Connected Coastal Lakes, A. Challen Hyman, Rom Lipcius, R. Gray, D. B. Stephens

VIMS Articles

Intermittently closed and open lakes and lagoons (ICOLLs) are coastal lakes that intermittently exchange water with the sea and experience saline intrusions. Understanding effects of seawater exchange on local biota is important to preserve ecosystem functioning and ecological integrity. Coastal dune lakes of northwest Florida are an understudied group of ICOLLs in close geographic proximity and with entrance regimes operating along a frequency continuum. We exploited this natural continuum and corresponding water chemistry gradient to determine effects of water chemistry on resident submersed aquatic vegetation (SAV) distributions in these ecosystems. SAV distribution decreased with increases in salinity, but was unaffected …

Estimation Of Odds Ratio In 2 X 2 Contingency Tables With Small Cell Counts, Guohao Zhu

Dissertations

This study is focusing on properties of estimators of odds ratio or its logarithm in case of 2x2 tables with small counts. The odds ratio represents the odds that an outcome of interest will occur given a particular exposure, compared to the odds of the outcome occurring in the absence of that exposure. Both parameters are often used to quantify the strength of association of two binary variables and are common measurements reported in case-control, cohort, and cross-sectional studies.

Because of their wide applicability, both parameters, odds ratio, and its logarithm, have been intensively studied in the literature. However, most …

Effects Of Translocation On Survival Of Nuisance Bears, Javan Bauder, D. Ruid, N. M. Roberts, B. Kohn, M. L. Allen

United States Department of Agriculture Wildlife Services: Staff Publications

Effective mitigation of human–wildlife conflict should aim to reduce conflicts while also minimizing wildlife mortality. Translocation is often used to mitigate human–wildlife conflict but translocated individuals may have reduced survival, which could negatively affect population growth and social acceptance of translocation as a management tool. Yet, non-translocated nuisance individuals may also have low survival due to inherent risks associated with nuisance behavior. We used a 38-year dataset of 1233 marked and translocated nuisance American black bears (Ursus americanus) as a model system with which to evaluate the impacts of translocation on nuisance bear survival. We used multi-state mark-recapture models to …

The Morphology And Evolution Of Transverse Aeolian Ridges On Mars, Timothy Paul Nagle-Mcnaughton

Earth and Planetary Sciences ETDs

Transverse aeolian ridges (TARs) are enigmatic and largely relict bedforms on the surface of Mars. TARs are sparsely distributed but common on Mars, but their history, preservation, and past role in the sediment cycle is not well understood. First described in 2003, and detailed extensively in 2008, our study of TARs has been narrowly focused in the last decade, with more and more research noting their presence, but little investigation of the features themselves. Recent work has mostly focused on identifying Terran analogues for TARs, but TARs remain largely a unique Martian feature. In this manuscript, I clarify and refine …

Murrells Inlet Assessment 2021, Bailie Willis, Amanda Giambi, Anastasia Gluth, Julia Angell, Cain Rullo

Goal 11: Sustainable Cities and Communities

No abstract provided.

Identification Of Factors Associated With Fume Events Using Text Mining And Data Mining Methods, Mary B. O'Connor

Doctoral Dissertations and Master's Theses

Pilots, flight attendants, and passengers can be exposed to toxic compounds when the bleed air that supplies the cabin and flight deck is contaminated with pyrolyzed hydraulic fluid or oil from turbine jet engines. These fume events occur sporadically and can result in acute or chronic exposure in air crews and can have catastrophic consequences if flight crew members become impaired or incapacitated. The purpose of this research was to explore unstructured textual data and identify important factors associated with these events. Models using machine learning algorithms were developed and tested using variables gleaned from the text mining process and …

(2021 Revision) Chapter 4: Essential Aspects Of Physical Design And Implementation Of Relational Databases, Tatiana Malyuta, Ashwin Satyanarayana

Open Educational Resources

No abstract provided.

(2021 Revision) Chapter 5: Essential Aspects Of Physical Design And Implementation Of Relational Databases, Tatiana Malyuta, Ashwin Satyanarayana

Open Educational Resources

No abstract provided.

(2021 Revision) Chapter 1: Essential Aspects Of Physical Design And Implementation Of Relational Databases, Tatiana Malyuta, Ashwin Satyanarayana

Open Educational Resources

No abstract provided.

(2021 Revision) Chapter 3: Essential Aspects Of Physical Design And Implementation Of Relational Databases, Tatiana Malyuta, Ashwin Satyanarayana

Open Educational Resources

No abstract provided.

(2021 Revision) Chapter 6: Essential Aspects Of Physical Design And Implementation Of Relational Databases, Tatiana Malyuta, Ashwin Satyanarayana

Open Educational Resources

No abstract provided.

(2021 Revision) Chapter 2: Essential Aspects Of Physical Design And Implementation Of Relational Databases, Tatiana Malyuta, Ashwin Satyanarayana

Open Educational Resources

No abstract provided.

(2021 Revision) Chapter 7: Essential Aspects Of Physical Design And Implementation Of Relational Databases, Tatiana Malyuta, Ashwin Satyanarayana

Open Educational Resources

No abstract provided.

Replicating Analyses Of Item Response Curves Using Data From The Force And Motion Conceptual Evaluation, Connor J. Richardson, Trevor Smith, Paul J. Walter

College of Science & Mathematics Departmental Research

Ishimoto, Davenport, and Wittmann have previously reported analyses of data from student responses to the Force and Motion Conceptual Evaluation (FMCE), in which they used item response curves (IRCs) to make claims about American and Japanese students’ relative likelihood to choose certain incorrect responses to some questions. We have used an independent dataset of over 6,500 American students’ responses to the FMCE to generate IRCs to test their claims. Converting the IRCs to vectors, we used dot product analysis to compare each response item quantitatively. For most questions, our analyses are consistent with Ishimoto, Davenport, and Wittmann, with some results …