Physical Sciences and Mathematics Commons^™

Anomalous Stranski-Krastanov Growth Of (111)-Oriented Quantum Dots With Tunable Wetting Layer Thickness, Christopher F. Schuck, Simon K. Roy, Trent Garrett, Paul J. Simmonds

Materials Science and Engineering Faculty Publications and Presentations

Driven by tensile strain, GaAs quantum dots (QDs) self-assemble on In_0.52Al_0.48As(111)A surfaces lattice-matched to InP substrates. In this study, we show that the tensile-strained self-assembly process for these GaAs(111)A QDs unexpectedly deviates from the well-known Stranski-Krastanov (SK) growth mode. Traditionally, QDs formed via the SK growth mode form on top of a flat wetting layer (WL) whose thickness is fixed. The inability to tune WL thickness has inhibited researchers’ attempts to fully control QD-WL interactions in these hybrid 0D-2D quantum systems. In contrast, using microscopy, spectroscopy, and computational modeling, we demonstrate that for GaAs(111)A QDs, we …

Comprehensive Investigation Of Bioactive Steroidal Alkaloids In Veratrum Californicum, Matthew West Turner

Boise State University Theses and Dissertations

Veratrum californicum, commonly referred to as corn lily or Californian false hellebore, grows in high mountain meadows and produces bioactive steroidal alkaloids, including cyclopamine. Cyclopamine is a potent inhibitor of the Hedgehog (Hh) signaling pathway. Our lab has optimized methods to extract cyclopamine and related steroidal alkaloids from V. californicum, and implemented in-house Hh signaling bioactivity evaluation of these steroidal alkaloids using a Shh-Light II cell assay. A survey of extraction methods and solvents resulted in the identification of conditions most favorable for alkaloid extraction yield and antagonist activity in the Shh-Light II cell assay. The highest amount …

The Spatial Distribution Of Elevated Uranium In The Treasure Valley Aquifer System, Southwest Idaho, Lloyd A. Womeldorph

Boise State University Theses and Dissertations

The Treasure Valley Aquifer System (TVAS) in southwestern Idaho contains well-documented uranium concentrations over the U.S. Environmental Protection Agency maximum contaminant level of 30 µg/L. With a population in the Treasure Valley projected to reach 1.6 million by 2065, in-depth horizontal and vertical spatial knowledge of the contaminant is needed. This study evaluates the horizontal and vertical spatial nature of uranium in the TVAS and interprets those observations to provide both a conceptual model of uranium behavior, and recommendations for water resource management. A large water quality dataset was compiled, and supplemented by data collected during a field sampling campaign, …

Informing Field Management Decisions To Enhance Alfalfa Seed Production Using Remote Sensing, Thomas V. Van Der Weide

Boise State University Theses and Dissertations

The development rate of alfalfa seed crop depends on both environmental conditions and management decisions. Crop management decisions, such as determining when to release pollinators to optimize pollination, can be informed by the identification of plant development stages from remote sensing data. I first identify what electromagnetic wavelengths are sensitive to alfalfa plant development stages using hyperspectral data. A Random Forest regression is used to determine the best Vegetation Index (VI) to monitor how much of the plant is covered in flower. The results indicate that Blue, Green, and Near-Infrared are the important electromagnetic wavelengths for the VI. Imagery collected …

Geomorphology And Geochronology Of Sand Ramps Adjoining The Coral Pink Sand Dunes, Kane County, Utah, Kerri E. Spuller

Boise State University Theses and Dissertations

Projected climate change is expected to have widespread impacts on arid regions of the world. Inland, continental dune fields are sensitive to changes in climate and the surrounding environment and are an important source for understanding interactions between Earth’s surface, atmosphere, and biosphere in drylands. Reconstructing past periods of aeolian activity from dune fields can provide insights into how landscapes have responded to previous changes in climate. However, the nature of aeolian systems to recycle older deposits leads to a preservation bias towards only the youngest deposits. Targeting geomorphic settings that are conducive to preserving older records is critical to …

Characterizing Dryland Ecosystems Using Remote Sensing And Dynamic Global Vegetation Modeling, Abdolhamid Dashtiahangar

Boise State University Theses and Dissertations

Drylands include all terrestrial regions where the production of crops, forage, wood and other ecosystem services are limited by water. These ecosystems cover approximately 40% of the earth terrestrial surface and accommodate more than 2 billion people (Millennium Ecosystem Assessment, 2005). Moreover, the interannual variability of the global carbon budget is strongly regulated by vegetation dynamics in drylands. Understanding the dynamics of such ecosystems is significant for assessing the potential for and impacts of natural or anthropogenic disturbances and mitigation planning, and a necessary step toward enhancing the economic and social well-being of dryland communities in a sustainable manner (Global …

Multilingual Information Retrieval: A Representation Building Perspective, Ion Madrazo

Boise State University Theses and Dissertations

Information Retrieval (IR) has changed the way we access digital resources and satisfy our daily information needs. Popular IR tools like Search Engines, Recommendation Systems, and Automatic Question Answering sites, act as a deterrent for information overload while fostering (at least in theory) the democratization of access to resources. Yet, in their majority, IR tools are built with a traditional user in mind. This causes users who deviate from the norm, e.g., users with low educational background, visually-impaired users, or users who speak different languages, to be undeserved and thus struggle to find the information they require. In this manuscript, …

Falcon: Framework For Anomaly Detection In Industrial Control Systems, Subin Sapkota

Boise State University Theses and Dissertations

Industrial Control Systems (ICS) are used to control physical processes in the nation's critical infrastructures. They are composed of subsystems that control physical processes by analyzing the information received from the sensors. Based on the state of the process, the controller issues control commands to the actuators. These systems are utilized in a wide variety of operations such as water treatment plants, power, and manufacturing, etc. While the safety and security of these systems are of high concern, recent reports have shown an increase in targeted attacks that are aimed at manipulating the physical processes to cause catastrophic consequences. This …

Ribbon Α-Conotoxin Ktm Exhibits Potent Inhibition Of Nicotinic Acetylcholine Receptors, Leanna A. Marquart, Matthew W. Turner, Lisa R. Warner, Matthew D. King, James R. Groome, Owen M. Mcdougal

Chemistry and Biochemistry Faculty Publications and Presentations

KTM is a 16 amino acid peptide with the sequence WCCSYPGCYWSSSKWC. Here, we present the nuclear magnetic resonance (NMR) structure and bioactivity of this rationally designed α-conotoxin (α-CTx) that demonstrates potent inhibition of rat α3β2-nicotinic acetylcholine receptors (rα3β2-nAChRs). Two bioassays were used to test the efficacy of KTM. First, a qualitative PC12 cell-based assay confirmed that KTM acts as a nAChR antagonist. Second, bioactivity evaluation by two-electrode voltage clamp electrophysiology was used to measure the inhibition of rα3β2-nAChRs by KTM (IC₅₀ = 0.19 ± 0.02 nM), and inhibition of the same nAChR isoform by α-CTx MII (IC₅₀ = …

The Community Outreach Model Of Service-Learning: A Case Study Of Active Learning And Service-Learning In A Natural Hazards, Vulnerability, And Risk Class, Brittany D. Brand, Kara Brascia, Margaret Sass

Geosciences Faculty Publications and Presentations

The popularity of service learning is increasing, especially at a time when college students want to make a greater impact in their communities. However, service learning has not been extensively assessed in courses based in science, technology, engineering, and mathematics. This article provides a case study of how incorporating service learning through a community outreach project can increase student engagement, enhance the depth of understanding of a given topic, build communication and teamwork skills, and contribute meaningfully to the students' community. This article shares how the instructor of a natural hazards, vulnerability, and risk course implements service-learning through a community …

Qualitative Assay To Detect Dopamine Release By Ligand Action On Nicotinic Acetylcholine Receptors, Leanna A. Marquart, Matthew W. Turner, Owen M. Mcdougal

Chemistry and Biochemistry Faculty Publications and Presentations

A pheochromocytoma of the rat adrenal medulla derived (a.k.a. PC12) cell-based assay for dopamine measurement by luminescence detection was customized for the qualitative evaluation of agonists and antagonists of nicotinic acetylcholine receptors (nAChRs). The assay mechanism begins with ligand binding to transmembrane nAChRs, altering ion flow into the cell and inducing dopamine release from the cell. Following release, dopamine is oxidized by monoamine oxidase generating hydrogen peroxide that catalyzes a chemiluminescence reaction involving luminol and horseradish peroxidase, thus producing a detectable response. Results are presented for the action of nAChR agonists (acetylcholine, nicotine, and cytisine), and antagonists (α-conotoxins (α-CTxs) MII, …

Detection And Countermeasure Of Saturation Attacks In Software-Defined Networks, Samer Yousef Khamaiseh

Boise State University Theses and Dissertations

The decoupling of control and data planes in software-defined networking (SDN) facilitates orchestrating the network traffic. However, SDN suffers from critical security issues, such as DoS saturation attacks on the data plane. These attacks can exhaust the SDN component resources, including the computational resources of the control plane, create a high packet loss rate and a long delay in delivering the OpenFlow messages due to the bandwidth consumption of the OpenFlow connection channel, and exhausting the buffer memory of the data plane.

Currently, most of the existing machine learning detection methods rely on a predefined time-window to start analyzing the …

Bullynet: Unmasking Cyberbullies On Social Networks, Aparna Sankaran

Boise State University Theses and Dissertations

Social media has changed the way people communicate with each other, and consecutively affected people's ability to empathize in both positive and negative ways. One of the most harmful consequences of social media is the rise of cyberbullying, which tends to be more sinister than traditional bullying given that online records typically live on the internet for quite a long time and are hard to control. In this thesis, we present a three-phase algorithm, called BullyNet, for detecting cyberbullies on Twitter social network. We exploit bullying tendencies by proposing a robust method for constructing a cyberbullying signed network. BullyNet analyzes …

Crevasse Initiation And History Within The Mcmurdo Shear Zone, Antarctica, Lynn Kaluzienski, Peter Koons, Ellyn Enderlin, Gordon Hamilton, Zoe Courville, Steven Arcone

Geosciences Faculty Publications and Presentations

While large-scale observations of intensified fracture and rifting can be observed through remote-sensing observations, understanding crevasse initiation may best be achieved with small-scale observations in which crevasses can be directly observed. Here we investigate the kinematic drivers of crevasse initiation in the McMurdo Shear Zone (MSZ), Antarctica. We delineated 420 crevasses from ∼95 km of 400 MHz frequency ground-penetrating radar data and compared these data with kinematic outputs derived from remotely-sensed ice surface velocities to develop a statistical method to estimate crevasse initiation threshold strain rate values. We found the MSZ to be dominated by simple shear and that surface …

Data Set For An Empirical Analysis Of Search Engines’ Response To Web Search Queries Associated With The Classroom Setting, Oghenemaro Anuyah, Ashlee Milton, Michael Green, Maria Soledad Pera

Computer Science Faculty Scripts and Data

This archive contains queries that capture information in different search contexts. The first file includes those written by children between the 3rd - 6th grade levels, while performing search tasks. We collected and archived this data between the April 2017 -- December 2018, based on Boise State University's IRB approval. We also include simulated queries we extracted from children's reviews. Additional columns in this dataset are children's grade levels, the query source, and the query type (i.e., if it is a keyword, phrase, or question query). The other files are comprised of queries that are meant to lead to the …

Developing And Optimizing Shrub Parameters Representing Sagebrush (Artemisia Spp.) Ecosystems In The Northern Great Basin Using The Ecosystem Demography (Edv2.2) Model, Karun Pandit, Hamid Dashti, Nancy F. Glenn, Alejandro N. Flores

Geosciences Faculty Publications and Presentations

Ecosystem dynamic models are useful for understanding ecosystem characteristics over time and space because of their efficiency over direct field measurements and applicability to broad spatial extents. Their application, however, is challenging due to internal model uncertainties and complexities arising from distinct qualities of the ecosystems being analyzed. The sagebrush-steppe ecosystem in western North America, for example, has substantial spatial and temporal heterogeneity as well as variability due to anthropogenic disturbance, invasive species, climate change, and altered fire regimes, which collectively make modeling dynamic ecosystem processes difficult. Ecosystem Demography (EDv2.2) is a robust ecosystem dynamic model, initially developed for tropical …

Recent Precipitation Decrease Across The Western Greenland Ice Sheet Percolation Zone, Hans-Peter Marshall, Tate Meehan

Geosciences Faculty Publications and Presentations

The mass balance of the Greenland Ice Sheet (GrIS) in a warming climate is of critical interest in the context of future sea level rise. Increased melting in the GrIS percolation zone due to atmospheric warming over the past several decades has led to increased mass loss at lower elevations. Previous studies have hypothesized that this warming is accompanied by a precipitation increase, as would be expected from the Clausius–Clapeyron relationship, compensating for some of the melt-induced mass loss throughout the western GrIS. This study tests that hypothesis by calculating snow accumulation rates and trends across the western GrIS percolation …

Exploring The Law Of Detrital Zircon: La-Icp-Ms And Ca-Tims Geochronology Of Jurassic Forearc Strata, Cook Inlet, Alaska, Usa, Trystan M. Herriott, James L. Crowley, Mark D. Schmitz, Marwan A. Wartes, Robert J. Gillis

Geosciences Faculty Publications and Presentations

Uranium-lead (U-Pb) geochronology studies commonly employ the law of detrital zircon: A sedimentary rock cannot be older than its youngest zircon. This premise permits maximum depositional ages (MDAs) to be applied in chronostratigraphy, but geochronologic dates are complicated by uncertainty. We conducted laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) and chemical abrasion-thermal ionization mass spectrometry (CA-TIMS) of detrital zircon in forearc strata of southern Alaska (USA) to assess the accuracy of several MDA approaches. Six samples from Middle–Upper Jurassic units are generally replete with youthful zircon and underwent three rounds of analysis: (1) LA-ICP-MS of ∼115 grains, with one date per …

Spatially Extensive Ground‐Penetrating Radar Snow Depth Observations During Nasa's 2017 Snowex Campaign: Comparison With In Situ, Airborne, And Satellite Observations, Hans-Peter Marshall

Geosciences Faculty Publications and Presentations

Seasonal snow is an important component of Earth's hydrologic cycle and climate system, yet it remains challenging to consistently and accurately measure snow depth and snow water equivalent (SWE) across the range of diverse snowpack conditions that exist on Earth. The NASA SnowEx campaign is focused on addressing the primary gaps in snow remote sensing in order to gain an improved spatiotemporal understanding of this important resource and to further efforts toward a future satellite‐based snow remote sensing mission. Ground‐penetrating radar (GPR) is an efficient and mature approach for measuring snow depth and SWE. We collected ~1.3 million GPR snow …

Snow Depth Variability In The Northern Hemisphere Mountains Observed From Space, Hans-Peter Marshall

Geosciences Faculty Publications and Presentations

Accurate snow depth observations are critical to assess water resources. More than a billion people rely on water from snow, most of which originates in the Northern Hemisphere mountain ranges. Yet, remote sensing observations of mountain snow depth are still lacking at the large scale. Here, we show the ability of Sentinel-1 to map snow depth in the Northern Hemisphere mountains at 1 km² resolution using an empirical change detection approach. An evaluation with measurements from ~4000 sites and reanalysis data demonstrates that the Sentinel-1 retrievals capture the spatial variability between and within mountain ranges, as well as their inter-annual …

The Convergence Of Financial And Esg Materiality: Taking Sustainability Mainstream, Ruth Jebe

Management Faculty Publications and Presentations

Sustainability reporting can be seen as an attempt to bring improved environmental, social, and governance (ESG) practices to mainstream business. However, this movement to mainstream is hampered by the disconnect between financial and ESG information. Both reporting streams use the concept of materiality to shape firms’ disclosure obligations, but the term carries different meanings for different organizations. One sustainability organization, the Sustainability Accounting Standards Board (SASB), has developed reporting standards to merge sustainability and financial information by leveraging the definition of materiality for financial reporting purposes. This use of financial materiality positions the SASB to collide with the Security and …

The Alleghanian Isthmus As The Trigger Of The Onset Of The Bashkirian Glaciation: Constraints From Warm-Water Benthic Foraminifera, Vladimir I. Davydov, Pedro Cózar

Geosciences Faculty Publications and Presentations

The timing of the final collision and particularly the disappearance of the gateway between the Rheic and Tethyan oceans is quite controversial and poorly established. The accurate timing on the gateway closure is vitally important for the understanding of global sea-level fluctuations, ocean circulation, regional and global environments, salinity and reorganization of the thermohaline circulation, enhanced deep water organic carbon production in the western Tethys and the overall decline of atmospheric CO₂ concentrations. Here we present a new approach by applying warm-water benthic foraminifera (WWBF) data to precisely constraint the Rheic-Tethys gateway (RTG) closure, utilizing taxonomic and statistical methods. …

Melpf Version 1: Modeling Error Learning Based Post-Processor Framework For Hydrologic Models Accuracy Improvement, Rui Wu, Lei Yang, Chao Chen, Sajjad Ahmad, Sergiu M. Dascalu, Frederick C. Harris Jr.

Geosciences Faculty Publications and Presentations

This paper studies how to improve the accuracy of hydrologic models using machine-learning models as post-processors and presents possibilities to reduce the workload to create an accurate hydrologic model by removing the calibration step. It is often challenging to develop an accurate hydrologic model due to the time-consuming model calibration procedure and the nonstationarity of hydrologic data. Our findings show that the errors of hydrologic models are correlated with model inputs. Thus motivated, we propose a modeling-error-learning-based post-processor framework by leveraging this correlation to improve the accuracy of a hydrologic model. The key idea is to predict the differences (errors) …

Regional Scale Dryland Vegetation Classification With An Integrated Lidar-Hyperspectral Approach, Hamid Dashti, Nancy F. Glenn, Nayani Ilangakoon, Josh Enterkine, Alejandro N. Flores

Geosciences Faculty Publications and Presentations

The sparse canopy cover and large contribution of bright background soil, along with the heterogeneous vegetation types in close proximity, are common challenges for mapping dryland vegetation with remote sensing. Consequently, the results of a single classification algorithm or one type of sensor to characterize dryland vegetation typically show low accuracy and lack robustness. In our study, we improved classification accuracy in a semi-arid ecosystem based on the use of vegetation optical (hyperspectral) and structural (lidar) information combined with the environmental characteristics of the landscape. To accomplish this goal, we used both spectral angle mapper (SAM) and multiple endmember spectral …

Steroidal Alkaloid Variation In Veratrum Californicum As Determined By Modern Methods Of Analytical Analysis, Matthew W. Turner, Meagan Rossi, Vannessa Campfield, John French, Ellie Hunt, Emily Wade, Owen M. Mcdougal

Chemistry and Biochemistry Faculty Publications and Presentations

Veratrum californicum is a rich source of steroidal alkaloids, many of which have proven to be antagonists of the Hedgehog (Hh) signaling pathway that becomes aberrant in over twenty types of cancer. These alkaloids first became known in the 1950's due to their teratogenic properties, which resulted in newborn and fetal lambs developing cyclopia as a result of pregnant ewes consuming Veratrum californicum. It was discovered that the alkaloids in V. californicum were concentrated in the root and rhizome of the plant with much lower amounts of the most active alkaloid, cyclopamine, present in the aerial plant, especially in …

An Effective Electric Dipole Model For Voltage-Induced Gating Mechanism Of Lysenin, Eric Krueger, Daniel Fologea

Physics Faculty Publications and Presentations

Lysenin is a pore-forming toxin, which self-inserts open channels into sphingomyelin containing membranes and is known to be voltage regulated. The mechanistic details of its voltage gating mechanism, however, remains elusive despite much recent efforts. Here, we have employed a novel combination of experimental and computational techniques to examine a model for voltage gating, that is based on the existence of an “effective electric dipole” inspired by recent reported structures of lysenin. We support this mechanism by the observations that (i) the charge-reversal and neutralization substitutions in lysenin result in changing its electrical gating properties by modifying the strength of …

On The Classification Of Vertex-Transitive Structures, John Clemens, Samuel Coskey, Stephanie Potter

Mathematics Faculty Publications and Presentations

We consider the classification problem for several classes of countable structures which are “vertex-transitive”, meaning that the automorphism group acts transitively on the elements. (This is sometimes called homogeneous.) We show that the classification of countable vertex-transitive digraphs and partial orders are Borel complete. We identify the complexity of the classification of countable vertex-transitive linear orders. Finally we show that the classification of vertex-transitive countable tournaments is properly above E₀ in complexity.

Ionoseis: A Package To Model Coseismic Ionospheric Disturbances, Thomas Dylan Mikesell, Lucie Rolland, Rebekah F. Lee, Florian Zedek, Pierdavide Coïsson, Jean-Xavier Dessa

CGISS Publications and Presentations

We present the framework of the modeling package IonoSeis. This software models Global Navigation Satellite System (GNSS) derived slant total electron content (sTEC) perturbations in the ionosphere due to the interaction of the neutral atmosphere and charged particles in the ionosphere. We use a simplified model to couple the neutral particle momentum into the ionosphere and reconstruct time series of sTEC perturbations that match observed data in both arrival time and perturbation shape. We propagate neutral atmosphere disturbances to ionospheric heights using a three-dimensional ray-tracing code in spherical coordinates called Windy Atmospheric Sonic Propagation (WASP3D), which works for a …

A Foundational Study Of A New Synthetic Method Of Metal Carbonyl Clusters, Miles Shaun Millard

Boise State University Theses and Dissertations

“Traditional” Metal Carbonyl Clusters (MCCs) contain a framework of multiple metal atoms bound together through formal metal-metal (M-M) bonds. Current methods of synthesis result in different cluster sizes and lack a method to control growth. This project proposes a new method of MCC synthesis to build larger structures utilizing secondary non-covalent interactions to develop “non-traditional” MCCs. The N,N’-diarylurea moiety is a strong hydrogen bond donor/acceptor that can induce self-assembly into larger secondary structures. The union of metal carbonyl and urea chemistry provides a potential method of “non-traditional” MCC synthesis. This proof of concept experiment will elucidate foundational information such …

Insights Into The Evolution Of The Galápagos Archipelago And Its Mantle Source From Monogenetic Near-Island Seamounts, Darin M. Schwartz

Boise State University Theses and Dissertations

Lavas erupted at ocean island volcanoes are classically used as probes of the deep Earth, with ultimate goals of discerning the compositional heterogeneity, structure and dynamics of the Earth’s mantle. However, sampling restricted to volcanic islands and large, submarine volcanic constructs alone likely results in limited spatial resolution of the mantle’s composition and structure, owing to homogenization in sub-island magma reservoirs. Further, islands provide poor temporal resolution given that their multigenetic construction can overprint any time progressive chemical variations and they subside with age making detailed sampling difficult. For my dissertation I investigate whether seamounts surrounding islands in the Galápagos …