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Evolution And Adaptation To Temperature In Thermotogota, Anne Amelia Farrell

Dartmouth College Ph.D Dissertations

Life thrives across incredibly diverse environmental conditions, yet most organisms are restricted to growing within a narrow range around their optimum growth temperature (OGT). The evolutionary events leading to changes in OGT are poorly understood, and it is uncertain if specific genes are required to thrive at a particular temperature. The bacterial phylum Thermotogota is an excellent model for the evolution of OGT. It comprises mesophilic, thermophilic, and hyperthermophilic members that collectively grow between 20°C and 90°C.

In this work, I analyze the history of OGT in the Thermotogota phylum and show how horizontal gene transfer contributes to the evolution …

Advances In Computational And Statistical Inverse Problems, Dylan Green

Dartmouth College Ph.D Dissertations

Inverse problems are prevalent in many fields of science and engineering, such as signal processing and medical imaging. In such problems, indirect data are used to recover information regarding some unknown parameters of interest. When these problems fail to be well-posed, the original problems must be modified to include additional constraints or optimization terms, giving rise to so-called regularization techniques. Classical methods for solving inverse problems are often deterministic and focus on finding point estimates for the unknowns. Some newer methods approach the solving of inverse problems by instead casting them in a statistical framework, allowing for novel point estimate …

Agronomic And Economic Productivity Of Summer Annual Forage Systems Under Different Poultry Litter Application Methods, Ivanelle Meyer, Michael P. Popp, Christine C. Nieman, Amanda J. Ashworth, Phillip R. Owens

Agricultural Economics and Agribusiness Faculty Publications and Presentations

Poultry litter (litter) is a nutrient dense fertilizer that increases nutritive value and yield in pastures in the mid-southern US. Nutrient losses due to runoff and nitrogen volatilization are common when broadcasting litter. As such, incorporating litter below the soil surface (subsurface) was evaluated in comparison to broadcasting in 2021 and 2022 by quantifying yield and nutritive value of annual forages. The study was a randomized complete block design with three forage treatments—sorghum-sudangrass only (Sorghum bicolor L.), cowpea only (Vigna unguiculata L.), and their mixture, and three litter application methods (broadcast, subsurface, and a no litter control). Litter …

Emerging Diseases, Abiotic Disorders, And Macrophomina Root Rot Management Of California Strawberry, Cooper Calvin

Master's Theses

Strawberry is an economically important crop in California, with an estimated value of $2.68 billion in 2023. In California strawberry production, mitigation of low plant health and yield often focuses on major soilborne pathogens, while the contribution of minor pathogens and abiotic disorders to production shortcomings are often overlooked. The objectives of the first project in this thesis are to determine the pathogenicity of multiple minor pathogens and quantify other biotic and abiotic factors that can reduce plant health such as viruses and soil salinity. Two pathogens of the black root rot complex, Pythium spp. and Rhizoctonia spp. as well …

Red Raspberries Attenuate Blood Glucose Spike Of A High Glycemic Load Breakfast Cereal, Dante J. Martin

Master's Theses

Blood glucose (BG) spikes increase chronic disease risk in those with and without diabetes. The fiber and phytonutrient content of fruit, such as raspberries has the potential to attenuate the BG spike of a high glycemic load (HGL) meal. We examined the effect of red raspberries (RRs) on the BG spike when added to a HGL meal. In this randomized cross-over trial, 16 university students were given breakfast cereal and almond milk (control), the control breakfast with 140g added RRs, and the control breakfast with sugar equivalent to the sugar content of the RRs (50% sugar increase from control). Meals …

Non-Linear Modeling Of Hysteresis In Piezoelectric Actuated Cantilever Beam Using The Bouc-Wen Model, Andrew Donald Maas

Master's Theses

Piezoelectric actuators frequently exhibit a time-dependent behavioral phenomenon known as hysteresis, resulting in a lag in the deformation of the actuator compared to linear models. The presence of hysteresis complicates control systems involving piezoelectric actuators. However, traditional modeling methods for piezoelectric actuated smart structures often treat the piezoelectric patches as linear actuators without considering hysteresis, leading to suboptimal controller performance.

This thesis aims to establish a comprehensive model by integrating the Euler-Bernoulli beam bending model with the hysteresis dynamics induced by two opposing piezoelectric patches attached to a beam. A model expansion method is employed to transform the partial differential …

Providing Cadence Feedback In Real-Time To Guide Cardiovascular Workouts, Levi O. Rash

Master's Theses

Cardiovascular workouts offer numerous health benefits, yet beginners often find it challenging to initiate them. Existing wearable technologies, although providing valuable feedback such as heart rate zones, often disrupt the workout flow and distract users due to the need for interaction with the wearable display. In response, we propose an alternative feedback mechanism: cadence, measured in steps per minute. This feedback mechanism uses multiplicative control to produce the correct cadence for the user’s target heart rate (HR). To model the HR and cadence relationship, a first-order system was used. The prototype implementation of this system was completed in Arduino, using …

The Effect Of Probiotic Supplementation On Serum Metabolite Concentrations In Young Holstein Heifers, Emily G. Meissner

Master's Theses

The objective of this trial was to evaluate the effect of a multi-strain probiotic on serum concentrations of selected metabolites in young calves. Holstein heifers (n = 112) from a commercial dairy were enrolled within 48 h of birth and placed into individual hutches. Calves were weaned at 60 d of age and remained in their hutches until 90 d of age, when they were moved to group housing. Calves were placed into 2 treatment groups: 1) control and 2) B. subtilis, B. lichenformis, L. animalis, and P. freudenreichii probiotic (Bovamine Dairy Plus, Chr. Hansen, Milwaukee, WI). Control calves received …

Deciphering The Contribution Of Microglia To Neurodegeneration In Friedreich's Ataxia, Sydney N. Gillette

Master's Theses

Friedreich's ataxia (FRDA) is the most prevalent inherited ataxia, affecting one in every 50,000 individuals in the United States. This hereditary condition is caused by an abnormal GAA trinucleotide repeat expansion within the first intron of the frataxin gene resulting in decreased levels of the frataxin protein (FXN). Insufficient cellular frataxin levels results in iron accumulation, increased reactive oxygen species production and mitochondrial dysfunction. Tissues most heavily impacted are those most dependent on oxidative phosphorylation as an energy source and include the nervous system and muscle tissue. This is evident in the clinical phenotype which includes muscle weakness, ataxia, neurodegeneration …

Hydrological Analysis Of Post-Fire Responses Within The Little Creek Watershed Of Swanton Pacific Ranch, Alexander Jeffrey Wiens

Master's Theses

Climate change and a growing wildland-urban interface are associated with an increase in the number and severity of wildfires. While severe wildfires do cause a costly and dangerous impact on the environment and the public, their after-effects comprise important subjects of study. In post-fire hydrologic studies, the reduced infiltration and plant cover that results from wildfires can commonly be associated with increased peakflows and erosion. Phenomena such as the flooding and debris flows in Montecito after the Thomas Fire in late 2017 can have important implications on infrastructure and human lives. Quantifying post-fire peak flows and flooding volumes has therefore …

Pain Points: Cluster Analysis In Chronic Pain Networks, Iris W. Ho

Master's Theses

Chronic pain is a pervasive health issue, affecting a significant portion of the population and posing complex challenges due to its diverse etiology and individualized impact. To address this complexity, there is a growing interest in grouping chronic pain patients based on their unique treatment needs. While various methodologies for patient grouping have emerged, leveraging graph-based approaches to produce and evaluate such groupings remains largely unexplored. Recent studies have shown promise in integrating knowledge graphs into exploring patient similarity across different biological domains, indicating potential avenues for research. Additionally, there is a growing interest in investigating patient similarity networks, highlighting …

Sequential Memory Generation For Cognitive Models, Eben Miles Sherwood

Master's Theses

Understanding the process of memory formation in neural systems is of great interest in the field of neuroscience. Valiant’s Neuroidal Model poses a plausible theory for how memories are created within a computational context. Previously, the algorithm JOIN has been used to show how the brain could perform conjunctive and disjunctive coding to store memories. A limitation of JOIN is that it does not consider the coding of temporal information in a meaningful manner. We propose SeqMem, a similar algorithmic primitive that is designed to encode a series of items within a random graph model. We investigate the feasibility of …

Scalable Hybrid Neuromorphic Accelerator & Hybrid Neural Networks, Joshua Nardone

Master's Theses

With machine learning workloads currently at very large scales, models are distributed across large compute systems. On distributed systems, the performance of these models are limited by the bandwidth limitations of chip-to-chip communication. To relieve this bottleneck, spiking neural networks (SNNs) can be utilized to reduce inter-chip communication traffic utilizing inherit network sparsity. However, in comparison to traditional artificial neural networks (ANNs), SNNs can have significant degradation in performance with increased network scale and complexity.

This research proposes a hybrid neural network accelerator that uses the best of both spiking and non-spiking layers by allocating a majority of resources to …

Exploring Gender Disparities In Collaboration Networks: An Analysis Of H-Indices And Collaborator Proximity, Andrew R. Estrada

Master's Theses

Research is crucial for expanding the boundaries of what is known, driving innovation, and solving problems faced by communities. It is carried out across all sectors of society by all matter of institutions. Academic research is one such sector that contributes to a plethora of disciplines. Research often compels collaboration among researchers, and as with any team, the dynamics and outcomes are affected by the individuals who contribute to the research. For instance, researchers can be from different institutions; therefore research teams can differ in collaboration distance -- the geographic distance between the organizations of authors. In a similar vein, …

Using Plankton Edna To Estimate Whale Abundances Off The California Coast: Data Integration And Statistical Modeling, Katherine Chan

Master's Theses

Understanding marine mammal populations and how they are affected by human activity and ocean conditions is vital, especially in tracking population declines and monitoring endangered species. However, tracking marine mammal populations and their distribution is challenging due to difficulties in observation and costs. Using surrounding plankton environmental DNA (eDNA) has the potential to provide an indirect measure of monitoring cetacean abundances based on ecological associations. This project aims to apply statistical methods to assess the relationship of visual abundances of common species of baleen whales with amplicon sequence variants (ASV) of plankton eDNA samples from the NOAA-CalCOFI Ocean Genomics (NCOG) …

Identification Of Downy Mildew Resistance In Wild Arugula And Evaluation Of Downy Mildew Causing Pathogens And Management Practices, Reilly B. Blair

Master's Theses

Downy mildew has been a potentially devastating constraint to crop production within the Brassicaceae family worldwide (CABI, 2022) and on the Central Coast of California (Smukler, et al, 2008; Koike, et al. 2007). Downy mildew is a foliar disease, caused by the pathogens in the Hyaloperonospora genus on plants within the Brassicaceae family (Goker, et al, 2009). Downy mildew is a disease that is common in region of the world with Coastal climates that provide humidity and moderate temperatures (Sarahan, et al, 2017). Crops within the Brassicaceae family maintain a predominant role in agricultural systems worldwide (Cartea, et al, 2011) …

Soil Profile Distribution Of Nutrients In Contrasting Soils Amended With Struvite And Other Conventional Phosphorus Fertilizers, Tatum Simms, Kristofor R. Brye, Trenton L. Roberts, Lauren F. Greenlee

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Phosphorus (P) can be recovered from wastewater and used as an alternative fertilizer, namely, struvite [MgNH₄PO₄·6(H₂O)]. However, the soil mobility of wastewater-derived P and other nutrients needs to be evaluated. The objective of this study was to compare the vertical distribution of water-soluble (WS) soil P and other nutrients from a synthetic-wastewater-derived electrochemically precipitated struvite (ECST) to that from a chemically precipitated struvite (CPST), triple superphosphate (TSP), monoammonium phosphate (MAP), and a control in six soils from Arkansas (AR; loam [L] and silt loam [SiL]), Missouri (MO; SiL 1 and SiL 2), and Nebraska …

Weed Control And Rice Response To Microencapsulated Acetochlor And A Fenclorim Seed Treatment On A Clay Soil, Tristen H. Avent, Jason K. Norsworthy

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Recent research has demonstrated the ability of a fenclorim seed treatment to reduce rice (Oryza sativa L.) injury to acetochlor. However, all studies were conducted on silt loam soils and have not evaluated rice tolerance or weed control on clay soils. Experiments were initiated in 2021 and 2022 at the Northeast Research and Extension Center near Keiser, AR, to determine rice response and the effectiveness of delayed-preemergence (DPRE)-applied microencapsulated (ME) acetochlor (1.1, 1.7, and 2.3 lb ai acre⁻¹) when applied to a clay soil with and without a fenclorim seed treatment at 0 or 2.5 lb ai …

Preference Of Dhurrin-Free Sorghum By Ewes, Shelby M. Gruss, Keith D. Johnson, John Scott Radcliffe, Ronald P. Lemenager, Mitchell R. Tuinstra

Animal and Food Sciences Faculty Publications

Sorghum [Sorghum bicolor (L.) Moench] is a resilient forage crop due to its drought tolerance and adaptation to low-N environments. Sorghum produces a cyanogenic glucoside called dhurrin. The breakdown of dhurrin leads to the release of hydrogen cyanide (HCN), which can cause cyanide toxicity in livestock. Dhurrin-free sorghum lines have been developed through chemical mutagenesis by mutagenizing the gene for the first enzyme, CYP79A1, in the biosynthetic pathway. The CYP79A1 mutation was bred into sorghum lines to create a dhurrin-free experimental hybrid. Grazing preference of ewes was assessed when allocated to the dhurrin-free hybrid and three commercial hybrids. Near isogenic …

Development Of Quercetin-Loaded Nanostructured Lipid Carrier For The Protection Of Dna Damage Induced By Particulate Matter, Suwisit Manmuan, Nattaya Chaothanaphat, Yotsanan Weerapol, Sukannika Tubtimsri

The Thai Journal of Pharmaceutical Sciences

Quercetin (QE) is a flavonoid found in several fruits and vegetables such as shallot, onion, and apple with proven antioxidant and anti-inflammatory properties that protect against and treat airway inflammation induced by particulate matter. Nanostructured lipid carriers (NLCs) with various liquid lipid types were employed to deliver QE into the respiratory tract. Physical properties of NLC formulations including particle size, stability, and entrapment efficiency were compared. Particle size of B_VCO and B_OLO formulations was 308.0 ± 0.4 nm and 104.8 ± 1.5 nm, respectively. After the temperature cycling test, particle size of B_OLO increased, while B_VCO was not significantly different. …

Design, Development, And Evaluation Of Doxorubicin Hydrochloride-Loaded Transfersomes For Transdermal Drug Delivery, Smriti Adhikari, Preethi Sudheer, Bindu Mohana, Poornachandra Somwarpet Manjunatha

The Thai Journal of Pharmaceutical Sciences

Background and Objectives: Doxorubicin hydrochloride (DOX-HCl), a potent and extensively utilized anticancer medication, faces limitations in skin penetration, resulting in confined effectiveness. Frequent administration leads to resistance at the site of application. This study aims to strike a balance between precision and selectivity to enhance DOX-HCl’s permeation. The goal is to achieve non-invasive drug delivery that avoids issues linked with conventional therapies. This will be achieved through the utilization of patches loaded with transfersomes for drug delivery. Materials and Methods: Transferosomes were prepared through the rotary evaporation technique and optimized by Box-Behnken experimental design. The impact of phospholipid, cholesterol, and …

Unraveling The Potential Of Natural Anti-Obesity Agents: An Insight, Naveen Kumar, Pranav Shah, Shweta Agarwal

The Thai Journal of Pharmaceutical Sciences

This review delves into the contemporary advancements and research on anti-obesity agents sourced from natural origins. Obesity, a pressing global health concern, necessitates effective interventions due to its association with various comorbidities such as hypertension and diabetes. Scientific data gathered from databases including PubMed and Scopus, as well as search engines such as Google and Google Scholar, focused on keywords such as “anti-obesity agents,” “herbal anti-obesity agents,” and “mechanism of action of anti-obesity agents.” The review highlights the escalating research efforts toward formulating safe and efficient dosage forms to combat obesity, with synthetic agents often linked to adverse effects. Natural …

Naturify 2300, Yarina Yiwei Dai

Masters Theses

In my art practice, I explore the interplay between human desires to manipulate and anthropomorphize nature, as seen in the technological augmentation of plants and living entities. This investigation delves into how this intersection, alongside empathy towards these creations, contributes to fears of uncontrollability and the risks of addiction and excessive dependence on technology.

Bioengineering and genetic modification have cultivated unprecedented developments, allowing humans to manipulate the fundamental building blocks of life. My research speculates on this technology further, modifying the genetic code of organisms and creating bioengineered wearable entities with enhanced traits or entirely new functionalities. The primary objective …

Architecture As A Carbon-Based Practice, Qixin Yu

Masters Theses

Carbon serves as both a silent protagonist and a looming antagonist in the narrative of architecture, shaping not only the physical structures we inhabit but also the ecological legacy we leave behind.

Centuries of human exploitation of the environment have led to climate and material crises. Shifting this dynamic requires action at micro (matter), meso (material), and macro (materiality) levels. Biogenic materials offer significant potential for carbon sequestration and present opportunities for the building industry to collaborate with nature rather than merely extract from it.

This thesis establishes a research and manufacturing practice that prioritizes material innovation, carbon sequestration, environmental …

Living Surfaces, Ryan R. Sotelo

Masters Theses

This thesis examines the role of architectural surfaces as a staging ground for personal objects that carry with them aspects of memory, narrative, and personal histories. The lived experience within architecture is often dismissed with the architect’s role in a building’s life ending at its physical conception. Architectural representations are often devoid of time, motion and personal histories in sake for spatial clarities. With precedent representations such as period room drawings, motion studies, and photographic guns, there was an interest in developing a representation to better examine the lived experience within our architecture.

By incorporating personal testimonies, accurate bedroom documentations …

Unconditioning Air, Weijia Deng

Masters Theses

Unconditioning Air rethinks the boundaries contrived through environmental control. For more than a century, HVAC (heating, ventilation, and air conditioning) defined the boundaries of interior air. The regime and tools of mechanical conditioning promise stability and manageability of indoor air quality at the expense of external phenomena, and by extension, any complexity or fluctuation in the environment. As a result, air conditioning premises that ideal interior comfort is “bubble-like”, requiring increasingly standardized and highly regimented regulatory tools. The plethora of patent drawings, duct specifications, and ASHRAE comfort codes produce an oppressively tightening grip over indoor air and comfort, rendering both …

Searching For The Hyperobject: Crystals As Transscalar Vehicles, Jay Costello

Masters Theses

When I touch the street outside my house, I'm touching Los Angeles—a contiguous vector of material bisecting a continent. A slab, a stone, dust and oil, a googolplex of tightly packed anisotropic particles... At nightfall, I sneak to the edge of the highway and break off a piece. 'What does it mean for a worm to be aware of the scale of the planet?' Bruno Latour's evocative questioning of scalar jumps prompts an existentialism that places me somewhere between the hyperlocal and the massively distributed. Like a cosmic traveler floating through the universe, I feel adrift. I look around, grasping …

Memory And Experiential Lab, Yufan Xu

Masters Theses

In the tapestry of our lives, there exist moments and places that we can never revisit, scenes etched into our memories that fade with the passage of time. These experiences and memories are treasures, provide us with an anchor to our past. Unfortunately, many of these moments are like fireflies in the night, here one moment and gone the next. Yet, they remain invaluable, forever etched in our hearts and minds. I wonder if it is possible to trigger cherished past experiences and memories in our daily lives, allowing individuals to re-experience similar moments, thereby nourishing the spiritual world. Therefore, …

Untitled, Lucia Steele

Masters Theses

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Homeward Bound: Moving Homes, Moving Home, Ella Nadeau

Masters Theses

The built environment has a powerful way of showing where our human attention and care is, a magic trick of emphasis and deemphasis. We proudly display our assets, wrapping them in light and gold while we shun the background people and places, choosing ubiquitous skins of plastic or brick in an effort to remove them from our visual language. Since we have had people we have had spaces to place them in but where some spaces relay the message that the person inside is a gift to the world, the majority chant a tired monotony of oppressive apathy: you do …