Digital Commons Network^™

On The Relative Importance Of Offshelf/Onshelf Drivers Of Variability In Mcdw Inventory On The Amundsen Shelf, Antarctica, Pierre St-Laurent, S. E. Stammerjohn, T. Maksym, R. M. Sherrell

Presentations

Ice shelves in the Amundsen Sea (west Antarctica) are melting rapidly and may raise global sea levels substantially over the coming century through reduced buttressing. The high basal melt rates are associated with the presence of warm modified Circumpolar Deep Water (mCDW) that intrudes across the continental shelf and melts the floating portion of the ice sheet from its base near the grounding zone. How much mCDW is present on the continental shelf (its volume inventory) is thus thought to be a key proxy for the year-to-year variability in ice shelf melt rates. Over the past decade, the literature has …

Voting Rules And Properties, Zhuorong Mao

Undergraduate Honors Theses

This thesis composes of two chapters. Chapter one considers the higher order of Borda Rules (Bp) and the Perron Rule (P) as extensions of the classic Borda Rule. We study the properties of those vector-valued voting rules and compare them with Simple Majority Voting (SMV). Using simulation, we found that SMV can yield different results from B1, B2, and P even when it is transitive. We also give a new condition that forces SMV to be transitive, and then quantify the frequency of transitivity when it fails.

In chapter two, we study the `protocol paradox' of approval voting. In approval …

Increasing Use Of Natural And Nature-Based Features To Build Resilience To Storm-Driven Flooding, Final Report, Center For Coastal Resources Management, Virginia Institute Of Marine Science, Pamela Mason, Jessica Hendricks, Julie Herman, Karen Duhring, Carl Hershner

Reports

In coastal Virginia today, local governments are dealing with recurrent flooding driven by coastal storms, exacerbated by rising sea level and increased frequency of intense rain events. At the same time, they are confronted with increasing demands on limited resources to address issues coastal flooding in concert with water quality, wetlands management, shoreline erosion, habitat, and community needs such as infrastructure, flood insurance and open space. One solution is to maximize the protection of existing and implement new natural and nature-based features (NNBFs) to capitalize on the provision of multiple benefits to address many of these coastal issues.

There are …

New Guidance To Build Resiliency And Mitigate For Sea Level Rise As Elements Of The Chesapeake Bay Preservation Act, Pamela Mason, Julie Herman, Christine Tombleson, Jessica Hendricks, Karen Duhring

Reports

The Center for Coastal Resources Management (CCRM), Virginia Institute of Marine Science (VIMS), worked in collaboration with the Virginia Department of Environmental Quality (DEQ) and the Virginia Coastal Policy Center (VCPC) to develop guidance to inform the implementation of Chesapeake Bay Preservation Act (CBPA) regulations promulgated in 2021. The 2021 regulations added provisions to require local governments to consider climate changes, specifically flooding, sea level rise and storms, and the preservation of mature trees in the administration of the CBPA program. Specifically, CCRM developed analytical data using criteria specified in the CBPA regulations, of the National Oceanic and Atmospheric Administration …

'Flux+Mutability': A Conditional Generative Approach To One-Class Classification And Anomaly Detection, Cristiano Fanelli, James Giroux, Z. Papandreou

Arts & Sciences Articles

Anomaly Detection is becoming increasingly popular within the experimental physics community. At experiments such as the Large Hadron Collider, anomaly detection is growing in interest for finding new physics beyond the Standard Model. This paper details the implementation of a novel Machine Learning architecture, called Flux+Mutability, which combines cutting-edge conditional generative models with clustering algorithms. In the 'flux' stage we learn the distribution of a reference class. The 'mutability' stage at inference addresses if data significantly deviates from the reference class. We demonstrate the validity of our approach and its connection to multiple problems spanning from one-class classification to anomaly …

Norfolk, Virginia Federal Flood Risk Management Study, Jian Shen, Rico Wang, Mac Sisson

Reports

The City of Norfolk and Norfolk District, U.S. Army Corps of Engineers (USACE), are partnering to conduct a Coastal Storm Risk Management Study (CSRM) study to determine the Federal interest and feasibility of alternatives to mitigate coastal flooding risk in the City. The CSRM is in the Feasibility Study (FS) phase in which alternatives are proposed and developed to conceptual/preliminary design level, benefit/cost analyses are conducted, and environmental studies are completed to comply with the National Environmental Policy Act (NEPA). The magnitude of the feasibility study will require an Environmental Impact Statement (EIS).

A component of the FS/EIS is the …

Deep Learning Fusion Of Satellite And Social Information To Estimate Human Migratory Flows, Daniel Runfola, Heather Baier, Laura Mills, Maeve Naughton-Rockwell, Anthony Stefanidis

Arts & Sciences Articles

Human migratory decisions are driven by a wide range of factors, including economic and environmental condi-tions, conflict, and evolving social dynamics. These factors are reflected in disparate data sources, including house-hold surveys, satellite imagery, and even news and social media. Here, we present a deep learning- based data fusion technique integrating satellite and census data to estimate migratory flows from Mexico to the United States. We leverage a three-stage approach, in which we (1) construct a matrix- based representation of socioeconomic information for each municipality in Mexico, (2) implement a convolutional neural network with both satellite imagery and the constructed …

Influence Of Oyster Genetic Background On Levels Of Human-Pathogenic Vibrio Spp., Corinne Audemard, Kimberly S. Reece, Robert J. Latour, Lydia M. Bienlien, Ryan B. Carnegie

VIMS Articles

Human-pathogenic Vibrio bacteria are common inhabitants of oyster tissues, but our understanding of factors driving the wide range of concentrations found in individual oysters is extremely limited. We examined the influence of oyster sex and parasitism in light of their profound effects on oyster tissues against a backdrop of eastern oysters, Crassostrea virginica, from two diploid and two triploid aquacultured lines. This allowed us to examine not only the effect of oyster ploidy but also of oyster genetics, a factor never investigated with regard to human-pathogenic Vibrio species. We measured levels of total Vibrio vulnificus (vvhA), and of …

Chesapeake Bay National Estuarine Research Reserve In Virginia Management Plan: 2022-2027, W. G. Reay, J. Baber, H. Brooks, A. Demeo, C. T. Friedrichs, C. Gonzales, J. Kuriawa, T. Hooper, S. Lerberg, E. J. Miles, B. Neikirk, S. Nuss, L. Ott, D. Parrish, T. Rudo, E C. Shields, S. Snyder, S. Wood

Reports

Established through the Coastal Zone Management Act, the National Estuarine Research Reserve System (NERRS) represents a partnership program between the National Oceanic and Atmospheric Administration (NOAA) and the coastal states to promote informed management of the Nation’s estuaries and habitats. Designated in 1991, and administered by the Virginia Institute of Marine Science (VIMS) of William & Mary, the Chesapeake Bay National Estuarine Research Reserve in Virginia (CBNERR-VA or Reserve) is one of 30 protected areas, which encompass over 1.3 million acres and make up the NERRS.

As the nation's largest estuary, the Chesapeake Bay contains a diverse collection of habitats …

Shear Turbulence In The High-Wind Southern Ocean Using Direct Measurements, Laur Ferris, Carole Anne Clayson, Donglai Gong, Et Al

VIMS Articles

The ocean surface boundary layer is a gateway of energy transfer into the ocean. Wind-driven shear and meteorologically forced convection inject turbulent kinetic energy into the surface boundary layer, mixing the upper ocean and transforming its density structure. In the absence of direct observations or the capability to resolve sub-grid scale 3D turbulence in operational ocean models, the oceanography community relies on surface boundary layer similarity scalings (BLS) of shear and convective turbulence to represent this mixing. Despite their importance, near-surface mixing processes (and ubiquitous BLS representations of these processes) have been under-sampled in high energy forcing regimes such as …

Precision Determination Of The Neutral Weak Form Factor Of ^48ca, D. Adhikari, (...), David S. Armstrong, Et Al.

Arts & Sciences Articles

We report a precise measurement of the parity-violating (PV) asymmetry APV in the elastic scattering of longitudinally polarized electrons from 48Ca. We measure APV=2668±106(stat)±40(syst) parts per billion, leading to an extraction of the neutral weak form factor FW(q=0.8733  fm−1)=0.1304±0.0052(stat)±0.0020(syst) and the charge minus the weak form factor Fch−FW=0.0277±0.0055. The resulting neutron skin thickness Rn−Rp=0.121±0.026(exp)±0.024(model)  fm is relatively thin yet consistent with many model calculations. The combined CREX and PREX results will have implications for future energy density functional calculations and on the density dependence of the symmetry energy of nuclear matter.

Beyond The Petermann Limit: Prospect Of Increasing Sensor Precision Near Exceptional Points, David D. Smith, Hongrok Chang, Eugeniy E. Mikhailov, Selim M. Shahriar

Arts & Sciences Articles

Experiments near the lock-in region in maximally dissipative non-Hermitian systems, e.g., conventional laser gyroscopes near the deadband, have run up against the Petermann limit, where excess noise exactly cancels any scale-factor enhancement resulting in no overall enhancement in precision. As a result, one might be tempted to conclude that exceptional points (EPs) generally cannot be used to increase the precision of laser sensors. Indeed, using a linear eigenmode analysis we show that the Petermann limit applies not just to maximally dissipative systems, but for any type of EP, owing to the fact that EPs are rotationally invariant. It turns out, …

Population Genetics Of Transposable Element Load: A Mechanistic Account Of Observed Overdispersion, Gregory Conradi Smith, Ron D. Smith, Joshua Puzey

Arts & Sciences Articles

In an empirical analysis of transposable element (TE) abundance within natural populations of Mimulus guttatus and Drosophila melanogaster, we found a surprisingly high variance of TE count (e.g., variance-to-mean ratio on the order of 10 to 300). To obtain insight regarding the evolutionary genetic mechanisms that underlie the overdispersed population distributions of TE abundance, we developed a mathematical model of TE population genetics that includes the dynamics of element proliferation and purifying selection on TE load. The modeling approach begins with a master equation for a birth-death process and extends the predictions of the classical theory of TE dynamics in …

Campus Nature Rx: How Investing In Nature Interventions Benefits College Students, Donald A. Rakow, Dorothy C. Ibes

Arts & Sciences Articles

Excerpt from article: "The college experience is a time of discovery, learning, and personal growth. However, many U.S. college students report unprecedentedly high levels of mental health problems during these formative years. According to the 2021 National Collegiate Health Assessment, over 30 percent of students received psychological or mental health services in the previous 12 months..."

Wind-Modulated Western Maine Coastal Current And Its Connectivity With The Eastern Maine Coastal Current, Denghui Li, Zhengui Wang, Huijie Xue, Andrew C. Thomas, Ron J. Etter

VIMS Articles

Using a high-resolution circulation model and an offline particle tracking model, we investigated variations of the Western Maine Coastal Current (WMCC) and its connectivity with the Eastern Maine Coastal Current (EMCC). The models showed that the weak, broad, and sinuous WMCC is generally southwestward with an offshore and a nearshore core, fed by the extension of the EMCC and runoff from the Penobscot and Kennebec–Androscoggin Rivers, respectively. A sea-level dome can form offshore of Casco Bay in late fall and early winter as the northeastward alongshore wind sets up a seaward sea-level gradient from the coast to meet the shoreward …

Vims Marine Science Day, Virginia Institute Of Marine Science

Miscellaneous

Brochure describing demonstrations and activities on this day of community outreach.

Town Of Colonial Beach Survey Of Central And Castlewood Beaches, Donna A. Milligan, C. Scott Hardaway Jr., Cameron W. Green, Alexander R. Milligan

Reports

The Town of Colonial Beach occupies a peninsula between the Potomac River and Monroe Bay. Approximately 2.5 miles of the shoreline is publicly-owned. Two areas on the Potomac River have been enhanced as recreational beaches for swimming and sunbathing. Central Beach is located just south of the Town Pier and is the main recreational beach. Castlewood Beach is south of Central Beach near the entrance to Monroe Bay.

Orbital-Selective Metallicity In The Valence-Bond Liquid Phase Of Li2 Ruo3, Patrick Mcardle, Fei-Ting Huang, Junjie Yang, (...), M. M. Qazilbash

Arts & Sciences Articles

Li2RuO3 (LRO) forms a valence bond crystal at room temperature. It undergoes a high temperature phase transition that involves structural, magnetic, and electronic changes leading to an exotic valence bond liquid state. The orbital degrees of freedom are thought to be fundamental to the evolution of LRO properties across the phase transition. We report temperature dependent broadband (100–26000cm–1) reflectance measurements on single crystals of LRO to elucidate structural and transport properties. Specifically, the phonon and electronic properties of LRO were investigated through the phase transition. We report that above the transition temperature (Tc≈500K), the optical band gap closes for electrons …

The Probability Mass Function Of The Kaplan-Meier Product-Limit Estimator, Yuxin Qin, Heather Sasinowska, Lawrence Leemis

Arts & Sciences Articles

Kaplan andMeier’s 1958 article developed a nonparametric estimator of the survivor function from a right censored dataset. Determining the size of the support of the estimator as a function of the sample size provides a challenging exercise for students in an advanced course in mathematical statistics. We devise two algorithms for calculating the support size and calculate the associated probability mass function for small sample sizes and particular probability distributions for the failure and censoring times.

Alkali Linewidths Under High Temperatures And Pressures Of 3he, Michael Parker

Undergraduate Honors Theses

Current research at Thomas Jefferson National Accelerator Facility is being conducted to study the spin structure of the neutron through collisions with polarized 3He nuclei. The helium is contained in high pressure glass vessels (called cells) along with nitrogen, rubidium, and potassium. To deduce the spin structure from collisions, we need to know the precise number density of 3He in the cell. The process of polarizing 3He through spin-exchange optical pumping requires nitrogen and alkali metal. We can use the absorption linewidths of rubidium and potassium to more accurately determine the density of helium. Throughout my research, I collected absorption …

Using A Machine Learning Model To Predict Plant Inflorescences Based Upon Its Soil Microbiome, Luke Denoncourt

Undergraduate Honors Theses

The UN estimates that the global population could reach 9.7 billion by 2050 (United Nations). As a result, the amount of food required to feed humanity is thought to double by 2050 (Ray et al., 2012). Humanity must find a way to increase crop production without increasing fertilizer usage and eutrophication, which can be done using the soil microbiome. Using potted plants with soils inoculated with Pseudomonas alcaligenes, Pseudomonas denitrificans, Bacillus polymyxa, and Mycobacterium phlei, both the shoot and root growth of pea and cotton plants was significantly increased (Egamberdieva & Höflich, 2004). In this study, utilizing a random forest …

Quantum Federated Learning: Training Hybrid Neural Networks Collaboratively, Anneliese Brei

Undergraduate Honors Theses

This thesis explores basic concepts of machine learning, neural networks, federated learning, and quantum computing in an effort to better understand Quantum Machine Learning, an emerging field of research. We propose Quantum Federated Learning (QFL), a schema for collaborative distributed learning that maintains privacy and low communication costs. We demonstrate the QFL framework and local and global update algorithms with implementations that utilize TensorFlow Quantum libraries. Our experiments test the effectiveness of frameworks of different sizes. We also test the effect of changing the number of training cycles and changing distribution of training data. This thesis serves as a synoptic …

Using Deep Learning With Satellite Imagery To Estimate Deforestation Rates, Maeve Naughton-Rockwell

Undergraduate Honors Theses

Previous studies have used Convolutional Neural Networks for regional detection of deforestation breaks. However, there is limited research into the capability of deep neural networks to identify sudden shifts in global forest cover from satellite imagery. Additionally, many deforestation detection models are trained on region specific data and need manual input thresholds. In this work, we develop a deep learning model to predict the percent of deforestation in a region between two points in time, trained on globally sourced data. Using the before and after satellite images of a deforestation event as inputs, we implemented a two input Convolutional Neural …

Bayesian Spatial Model Development Of Soil Core Organic Matter As A Proxy For Blue Carbon Stocks Within The Chesapeake Bay, Christian Longo

Undergraduate Honors Theses

Blue carbon is carbon captured and stored within bodies of water and their ecosystems. Blue carbon stocks are very important due to their ability to store carbon away from the atmosphere. The destruction of these stocks can accelerate climate change. In particular, we wish to assess blue carbon stock within the Chesapeake Bay. Previous studies have only used geographical features to predict blue carbon stock levels. The big picture question this thesis was meant to answer is: What is the best approach for building a statistical model that factors in both spatial parameters and geographical features to predict blue carbon …

Differential Protein Expression In Bacteriophages Crimd And Larva, Daria Moody

Undergraduate Honors Theses

Proteomics studies allow us to answer questions about differential protein expression across different systems. Mass spectrometry is a powerful tool in these studies due to the distinct masses of the amino acids that compose proteins. In our experiment, we used a bottom-up approach and focused on two bacteriophages found on the William & Mary campus, CrimD and Larva. The infection of Mycobacterium smegmatis, a nonpathogenic model for tuberculosis, by these two bacteriophages was frozen at five different timepoints, and our goal was to compare the differential protein expression across the samples in order to gain a greater understanding of …

An Atomic Magnetometer Based On Nonlinear Magneto-Optical Polarization Rotation, Jiahui Li

Undergraduate Honors Theses

Magnetometers with high precision and accuracy have wide applications across various areas. We are developing an atomic magnetometer based on nonlinear magneto-optical rotation (NMOR). The magnetometer measures the polarization rotation of a light field, which is proportional to the magnetic field strength. However, such a magnetometer usually has a limited operation range and stops working for fields stronger than the Earth's magnetic field. To overcome this shortage, we implement frequency and amplitude modulation that induces side frequencies in the Fourier space which allows us to measure strong magnetic fields, up to 200 mG. We have achieved 60 pT sensitivity for …

Development Of A Vector Magnetometer Based On Electromagnetically Induced Transparency In 87rb Atomic Vapor, Alexander Toyryla

Undergraduate Honors Theses

We present progress towards the development of an atomic magnetometer capable of accurate scalar and vector magnetic field measurements with high sensitivity and no need for external calibration. The proposed device will use the interaction between a bi-chromatic laser field and rubidium vapor to derive magnetic field magnitude and direction from measured amplitudes of Electromagnetically Induced Transparency (EIT) resonances. Since the proposed method requires precision control of light polarization, we observe the performance capabilities of a liquid crystal device to dynamically rotate the polarization of the laser field. Another goal in this project is to establish a polarization locking mechanism …

Machicomoco State Park Shoreline Management Plan, Cameron W. Green, Donna A. Milligan, C. Scott Hardaway Jr., Christine A. Wilcox

Reports

Machicomoco State Park (MSP) is located along the York River in Gloucester County, Virginia, between Cedarbush Creek and Timberneck Creek. Figures are shown in Appendix A. Archaeological evidence dating to the Middle and Late Woodland Periods (200 BCE – 1000 CE) strongly suggests that the area is associated with Tsenacommacah and the Powhatan’s chiefdom (DCR, 2021).

The site was primarily used as a base for hunting, fishing, and oystering activities. The area was later settled by English colonists around 1639, and was eventually sold to John Catlett in 1792, where it remained in the Catlett family’s possession for over 200 …

Gas-Phase Proton Affinities For Twenty Of The Proline-Containing Dipeptides, Henry Cardwell

Undergraduate Honors Theses

Peptide fragmentation plays a crucial role in the analysis of proteins through mass spectrometry-based proteomics. Most proteomics experiments take place in the low-energy regime and are governed by the mobile proton model which predicts random cleavages along the peptide backbone; however, there sometimes arise circumstances where the mobile proton model fails causing sequencing algorithms to misidentify peptides. One such example is noted in the “proline effect” wherein proline-containing peptides preferentially fragment N-terminal. While it has been established that the “proline effect” is due to the rigidity and basicity of the proline N-terminus, a further understanding of the factors influencing the …

Co-Planar Waveguides For Microwave Atom Chips, Morgan Logsdon

Undergraduate Honors Theses

This thesis describes research to develop co-planar waveguides (CPW) for coupling microwaves from mm-scale coaxial cables into 50 μm-scale microstrip transmission lines of a microwave atom chip. This new atom chip confines and manipulates atoms using spin-specific microwave AC Zeeman potentials and is particularly well suited for trapped atom interferometry. The coaxial-to-microstrip coupler scheme uses a focused CPW (FCPW) that shrinks the microwave field mode while maintaining a constant 50 Ω impedance for optimal power coupling. The FCPW development includes the simulation, design, fabrication, and testing of multiple CPW and microstrip prototypes using aluminum nitride substrates. Notably, the FCPW approach …