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Articles 59791 - 59820 of 302576

Full-Text Articles in Physical Sciences and Mathematics

Synthesis Of Bulky And Polar Galactonoamidines For The Inhibition Of The Human Α-Galactosidase, Ifedi Orizu May 2021

Synthesis Of Bulky And Polar Galactonoamidines For The Inhibition Of The Human Α-Galactosidase, Ifedi Orizu

Graduate Theses and Dissertations

Glycosidases are amongst the most abundant enzymes in nature. This is due to their role in the degradation of carbohydrates which are the major source of carbon or earth. The absence or malfunction of glycosidases is implicated in numerous diseases such as cancers, diabetes, and lysosomal storage disorders, which make them important drug targets for study in medicinal chemistry. The seminal work by Pauling and Wolfenden showed that enzymes bind to their substrate at the transition state with very strong affinity. Wolfenden estimated the dissociation constant to be around 10-22M. This encouraged the design of glycosidase inhibitors which mimicked one …


Climate Change Frames And Emotional Responses On Reddit, Isabel Iruani Villanueva May 2021

Climate Change Frames And Emotional Responses On Reddit, Isabel Iruani Villanueva

Graduate Theses and Dissertations

Climate change remains a highly polarized topic in the United States. Research suggests that the divide in climate change beliefs is partly a result of news media’s representation of select aspects of the problem, or framing. Frames influence individuals’ attitudes, emotions, and behaviors towards climate change. Overwhelming representation of certain climate change frames has led to a lack of emotional connection to the issue, resulting in inaction or dismissal. Climate change researchers have investigated the presence and effects of frames on both news media and select social media sites, particularly Twitter. However, little research has investigated the climate change conversation …


Effects Of The Triassic-Jurassic Central Atlantic Magmatic Event Recorded In Continental Strata In Western Pangea: The Δ13c Record Of Warner Valley & Zion National Park, Dennis Mmasa May 2021

Effects Of The Triassic-Jurassic Central Atlantic Magmatic Event Recorded In Continental Strata In Western Pangea: The Δ13c Record Of Warner Valley & Zion National Park, Dennis Mmasa

Graduate Theses and Dissertations

The Triassic is a period of abrupt climate change bracketed by mass extinctions including one driven by the eruption of the Central Atlantic Magmatic Province (CAMP) in the Late Triassic. The Moenave Formation (MF) of Utah and Arizona is ideal to investigate effects of the CAMP on continental strata distal to the eruptive center. This study focuses on the C-isotopic composition of bulk carbonate C from two localities, Blacks Canyon, Zion National Park, UT and Olsen Canyon within Warner Valley, UT. The data collected was used to document a chemostratigraphic record to compare to globally established records and bulk organic …


Climate-Driven Impacts On Himalayan Aquatic Biodiversity: A Case Study Involving Snowtrout (Cyprinidae: Schizothorax), Riri Wiyanti Retnaningtyas May 2021

Climate-Driven Impacts On Himalayan Aquatic Biodiversity: A Case Study Involving Snowtrout (Cyprinidae: Schizothorax), Riri Wiyanti Retnaningtyas

Graduate Theses and Dissertations

Monitoring biodiversity, to include its relative dispersal and contraction, has become a conservation task of great importance, particularly given the catastrophic and ongoing loss of habitat due to climate change. However, the timing, direction, and magnitude of these rates vary across taxa and ecosystems. Predicting specific impacts of climate change can thus be difficult and this, in turn, hampers management action. Metrics are needed to not only quantify contemporary requirements of species, but also predict potential distributions that fluctuate in lockstep with climate.

Montane ecosystems in the Himalayas are highly impacted by climate change, yet remain largely understudied due to …


The Influence Of Peer Irrigators On The Extensive And Intensive Margin Of Irrigation Techniques, Victoria Bailey May 2021

The Influence Of Peer Irrigators On The Extensive And Intensive Margin Of Irrigation Techniques, Victoria Bailey

Graduate Theses and Dissertations

We examine how irrigation techniques in use by family and friends influence the use and share of land utilizing different irrigation techniques by Arkansas producers. A bivariate sample selection model simultaneously estimates how farm characteristics determine the use and explain the share of a farm that utilizes an irrigation technique. We find that the irrigation techniques in use by family and friends do affect the irrigation techniques a producer uses and the share of acres utilizing different irrigation techniques. A producer with a family or friend that uses end-blocking irrigation is 41% more likely to use end-blocking themselves. Having a …


Electrochemical Oxidation Of Individual Silver Nanoparticles: Exploring The Effect Of Particle Shape, Capping Ligand, Electrolyte, And Potential On The Signal, Jazlynn Sikes May 2021

Electrochemical Oxidation Of Individual Silver Nanoparticles: Exploring The Effect Of Particle Shape, Capping Ligand, Electrolyte, And Potential On The Signal, Jazlynn Sikes

Graduate Theses and Dissertations

Nanomaterials have revolutionized science and technology. Their unique properties can be exploited, and nanoparticles are being used as catalysts, antimicrobials, drug delivery vehicles, sensors, and more. However, the fundamental properties of nanomaterials and their interactions with their surrounding environments are still poorly understood. In this work, a single-particle approach was used to observe the effects of capping ligand, surrounding solution, and particle shape on the oxidative process to gain deeper understanding of silver nanoparticle properties. When allowed the opportunity, the particles will adsorb to the electrode surface then oxidize in rapid succession upon electrode activation, regardless of capping ligand as …


Characterization Of Problematic Red Clay Soils In Arkansas For The Purpose Of Onsite Wastewater System Placement, Bailey Darnell May 2021

Characterization Of Problematic Red Clay Soils In Arkansas For The Purpose Of Onsite Wastewater System Placement, Bailey Darnell

Graduate Theses and Dissertations

Distinguishing between red-clay soils that are non-expansive and can reduce and red-clay soils developing in problematic red parent material, which are expansive, but also non-reducing, is key for proper on-site wastewater system placement. The Arkansas Department of Health allows for the placement of on-site wastewater systems in certain red-clay soils that have the potential to reduce, but only in the Ozark Highlands [Major Land Resource Area (MLRA) 116A], which is referred to as the red-soil exception. There is currently little scientific data to support the geographic restriction of the red-soil exception. The objectives of this study were to: i) confirm …


Carbon-Isotope Chemostratigraphy And Fluvial Sedimentology Of The Moenave Formation, Utah, Jordan Oefinger May 2021

Carbon-Isotope Chemostratigraphy And Fluvial Sedimentology Of The Moenave Formation, Utah, Jordan Oefinger

Graduate Theses and Dissertations

The end Triassic extinction (ETE) is one of the largest mass extinction events of the Phanerozoic, and it has been hypothesized that this event, as well as the Triassic-Jurassic (TJ) boundary, are preserved within the Moenave Formation of the Colorado Plateau. Identification of this boundary within southwest Utah sections of the Colorado Plateau region is critical for better understanding the relationship between climate change and the ETE in terrestrial, low latitude paleoenvironments. The Moenave Formation is well exposed in Blacks Canyon of Zion National Park and in the nearby Warner Valley, where detailed sedimentologic observations and carbon isotope sampling have …


Autonomous Aerial Vehicle Vision And Sensor Guided Landing, Gabriel Bitencourt, Elijah J. Brown, Cedric Bleimling, Gilbert Lai, Arman Molki, Tolga Kaya May 2021

Autonomous Aerial Vehicle Vision And Sensor Guided Landing, Gabriel Bitencourt, Elijah J. Brown, Cedric Bleimling, Gilbert Lai, Arman Molki, Tolga Kaya

School of Computer Science & Engineering Faculty Publications

The use of autonomous landing of aerial vehicles is increasing in demand. Applications of this ability can range from simple drone delivery to unmanned military missions. To be able to land at a spot identified by local information, such as a visual marker, creates an efficient and versatile solution. This allows for a more user/consumer friendly device overall. To achieve this goal the use of computer vision and an array of ranging sensors will be explored. In our approach we utilized an April Tag as our location identifier and point of reference. MATLAB/Simulink interface was used to develop the platform …


Ship-Gan: Generative Modeling Based Maritime Traffic Simulator, Chaithanya Basrur, Arambam James Singh, Arunesh Sinha, Akshat Kumar May 2021

Ship-Gan: Generative Modeling Based Maritime Traffic Simulator, Chaithanya Basrur, Arambam James Singh, Arunesh Sinha, Akshat Kumar

Research Collection School Of Computing and Information Systems

Modeling vessel movement in a maritime environment is an extremely challenging task given the complex nature of vessel behavior. Several existing multiagent maritime decision making frameworks require access to an accurate traffic simulator. We develop a system using electronic navigation charts to generate realistic and high fidelity vessel traffic data using Generative Adversarial Networks (GANs). Our proposed Ship-GAN uses a conditional Wasserstein GAN to model a vessel's behavior. The generator can simulate the travel time of vessels across different maritime zones conditioned on vessels' speeds and traffic intensity. Furthermore, it can be used as an accurate simulator for prior decision …


Thruster Communication For Subsurface Environments; Turning Waste Noise Into Useful Data, Stephen Cronin May 2021

Thruster Communication For Subsurface Environments; Turning Waste Noise Into Useful Data, Stephen Cronin

Doctoral Dissertations and Master's Theses

Acoustic communication serves as one of the primary means of wirelessly communicating underwater. Whereas much of the developments in the field of wireless communication have focused on radio frequency technology, water highly absorbs radio waves rendering the link not feasible for most all subsurface operations. While acoustic links have enabled new capabilities for systems operating in this challenging environment, it has yet to reach the commodity availability of radio systems, meaning that an entire class of small, low-cost systems have been unable to make use of these links. The systems in question are primarily autonomous underwater vehicles (AUVs), as they …


Mathematical Models In Medicine: The Immune Response Of Celiac Disease And The Environmental Transmission Of Clostridioides Difficile In Healthcare Settings, Cara Jill Sulyok May 2021

Mathematical Models In Medicine: The Immune Response Of Celiac Disease And The Environmental Transmission Of Clostridioides Difficile In Healthcare Settings, Cara Jill Sulyok

Doctoral Dissertations

Mathematical modeling is a useful technique to describe dynamics happening within events and allows one to address questions and test hypotheses that may be not be feasible to study in reality. This work uses mathematical models to describe two such phenomena, one relating to immunology and the other to the spread of infectious diseases.

Celiac disease is a hereditary autoimmune disease that affects approximately 1 in 133 Americans. It is caused by a reaction to the protein gluten found in wheat, rye, and barley. After ingesting gluten, a patient with celiac disease may experience a range of unpleasant symptoms while …


Object Detection And Recognition Using Yolo: Detect And Recognize Url(S) In An Image Scene, John Ajala May 2021

Object Detection And Recognition Using Yolo: Detect And Recognize Url(S) In An Image Scene, John Ajala

Culminating Projects in Computer Science and Information Technology

The world in the 21st century is ever evolving towards automation. This upsurge seemingly has no decline in the foreseeable future. Image recognition is at the forefront of this charge which seeks to revolutionize the way of living of the average man. If robotics can be likened to the creation of a body for computers to live in, then image processing is the development of the part of its brain which deal with identification and recognition of images.

To accomplish this task, we developed an object detection algorithm using YOLO, and acronym for “You Only Look Once”. Our algorithm was …


Approximate Difference Rewards For Scalable Multigent Reinforcement Learning, Arambam James Singh, Akshat Kumar, Hoong Chuin Lau May 2021

Approximate Difference Rewards For Scalable Multigent Reinforcement Learning, Arambam James Singh, Akshat Kumar, Hoong Chuin Lau

Research Collection School Of Computing and Information Systems

We address the problem ofmultiagent credit assignment in a large scale multiagent system. Difference rewards (DRs) are an effective tool to tackle this problem, but their exact computation is known to be challenging even for small number of agents. We propose a scalable method to compute difference rewards based on aggregate information in a multiagent system with large number of agents by exploiting the symmetry present in several practical applications. Empirical evaluation on two multiagent domains - air-traffic control and cooperative navigation, shows better solution quality than previous approaches.


Simulation Of The Interaction Between Striated Muscle Unc-45 And Transcription Factor Gata-4, Drake Alexander Duncan May 2021

Simulation Of The Interaction Between Striated Muscle Unc-45 And Transcription Factor Gata-4, Drake Alexander Duncan

Electronic Theses and Dissertations

Striated Muscle UNC-45, also known as UNC-45b, is an important protein that acts as a chaperone for myosin in cardiac and skeletal muscles, binding to myosin at its C-terminal UCS domain and regulating its assembly into thick filaments and sarcomeric structures. The UCS domain contains a large loop that is believed to be the first point of interaction between myosin and UNC-45b. GATA-4 is an essential transcription factor that facilitates transcription of several genes in cardiac development, particularly alpha-heavy chain myosin in heart tissue. Recently, studies have shown that there is interaction of GATA-4 with UNC-45b and that GATA-4 binds …


A Multifunctional Solution Composed Of Tmpyp, 1,5-Dhn, And Fe(Iii) Ions That Produces Reactive Oxygen Species (Ros) In Aerobic, Anaerobic, And H2o2 Environments, Aqeeb Ali May 2021

A Multifunctional Solution Composed Of Tmpyp, 1,5-Dhn, And Fe(Iii) Ions That Produces Reactive Oxygen Species (Ros) In Aerobic, Anaerobic, And H2o2 Environments, Aqeeb Ali

Electronic Theses and Dissertations

Photodynamic therapy (PDT) has become a widely popular therapeutic approach for treating various types of cancer over the past several decades. PDT utilizes a photosensitizer, visible light, and oxygen, to produce reactive oxygen species (ROS) which can be used to treat cancer and inhibit growth of bacteria. In this study, a multifunctional solution that is comprised of Fe(III) ions, cationic meso-tetra(N-methyl-4-pyridyl)porphine tetrachloride (TMPyP), and 1,5-dihydroxynapthalene (1,5-DHN), was shown to produce reactive oxygen species (ROS) such as singlet oxygen (1O2) or hydroxyl radicals (ȮH) in aerobic or anaerobic environments, respectively, and in both environments, 1,5-DHN was oxidized …


Lc-Ms/Ms Method Development And Analysis Of Tricyclic Antidepressants In Human Plasma, Shahbaz Gul May 2021

Lc-Ms/Ms Method Development And Analysis Of Tricyclic Antidepressants In Human Plasma, Shahbaz Gul

Honors Theses

Depression has become one of the most prominent problems in society, disrupting both personal and social lives. Tricyclic antidepressants (TCAs) were first developed in the 1950’s and became some of the leading anti-depressant medications on the market later that decade. Today, newer anti-depressants have risen to the forefront, being safer and having a lower side-effect probability. Nonetheless, TCAs continue to be prescribed for severe depression, especially in cases where the newer anti-depressants have failed. However, TCAs are still highly potent, the toxicity associated with these compounds cannot be ignored. They have considerable cardiovascular and neurological toxicity, and in the event …


Spectroscopic Analysis Of Potential Astromolecules Via Quantum Chemical Quartic Force Fields, Mason Gardner May 2021

Spectroscopic Analysis Of Potential Astromolecules Via Quantum Chemical Quartic Force Fields, Mason Gardner

Honors Theses

Astrochemistry has been substantially aided by computational techniques, particularly through the use of Quartic Force Field (QFF) analysis. Several methods have proven useful at correlating computed spectroscopic data with experimental observations. The F12-TZ QFF correlated well with experimental data for silicon oxide compounds, particularly those potentially involved in development from rocky bodies to planetary masses [27]. Compared to argon matrix experimental data, the vibrational frequencies for the molecules SiO2, SiO3, Si2O3, and Si2O4 become less accurate as the complexity of the molecules increases but should still be predictive of infrared characteristics of silicon oxides as they form clusters in space …


Determination Of Metals In Whey And Vegan Protein Supplements Using Inductively Coupled Plasma Mass Spectrometry, Megan Lofaso May 2021

Determination Of Metals In Whey And Vegan Protein Supplements Using Inductively Coupled Plasma Mass Spectrometry, Megan Lofaso

Honors Theses

Driven by a demand for health and wellness products worldwide, the dietary supplement industry continues to expand with an economic impact >$100 billion in the USA alone. However, the industry is plagued by a lack of regulation and incidents of contamination, including with toxic heavy metals that can put consumers at potential risk. In this study, eight trace elements (Cd, Pb, Fe, Co, Mn, V, Cu, and Cr), including heavy metals (Cd and Pb), were determined in whey and vegan protein powder by inductively coupled plasma mass spectrometry (ICP-MS) after microwave-assisted digestion using nitric acid and hydrogen peroxide. Samples were …


A Weighted Version Of Erdős-Kac Theorem, Unique Subedi May 2021

A Weighted Version Of Erdős-Kac Theorem, Unique Subedi

Honors Theses

Let $\omega(n)$ denote the number of distinct prime factors of a natural number $n$. A celebrated result of Erd{\H o}s and Kac states that $\omega(n)$ as a Gaussian distribution. In this thesis, we establish a weighted version of Erd{\H o}s-Kac Theorem. Specifically, we show that the Gaussian limiting distribution is preserved, but shifted, when $\omega(n)$ is weighted by the $k-$fold divisor function $\tau_k(n)$. We establish this result by computing all positive integral moments of $\omega(n)$ weighted by $\tau_k(n)$.

We also provide a proof of the classical identity of $\zeta(2n)$ for $n \in \mathbb{N}$ using Dirichlet's kernel.


Soil Inhomogeneity Effects On Seismic Wind Noise, Bipin Koirala May 2021

Soil Inhomogeneity Effects On Seismic Wind Noise, Bipin Koirala

Honors Theses

Wind causes local pressure fluctuations over the ground. The pressure waves couples with the ground and transmits into the ground as seismic waves. The seismic wave, in turn, causes ground motion. Naderyan et al. [9] developed a prediction of the ground displacements spectra from the measured ground properties and predicted pressure and shear stress at the ground surface. Naderyan modeled the ground as a linearly elastic half space bounded by an infinite plane on one side. The quasi-static model for predicting displacement components in the ground is effective for the vertical component of the displacement response, but the model significantly …


Curved Spacetime In The Causal Set Approach To Quantum Gravity, Ayush Dhital May 2021

Curved Spacetime In The Causal Set Approach To Quantum Gravity, Ayush Dhital

Honors Theses

Causal Set theory is an approach to quantum gravity. In this approach, the spacetime continuum is assumed to be discrete rather than continuous. The discrete points in a causal set can be seen as a continuum spacetime if they can be embedded in a manifold such that the causal structure is preserved. In this regard, a manifold can be constructed by embedding a causal set preserving causal information between the neighboring points. In this thesis, some of the fundamental properties of causal sets are discussed and the curvature and dimension information of Minkowski, de Sitter, and Anti-de Sitter spaces is …


Use Of Linear Discriminant Analysis In Song Classification: Modeling Based On Wilco Albums, Caroline Pollard May 2021

Use Of Linear Discriminant Analysis In Song Classification: Modeling Based On Wilco Albums, Caroline Pollard

Honors Theses

The study of music recommender algorithms is a relatively new area of study. Although these algorithms serve a variety of functions, they primarily help advertise and suggest music to users on music streaming services. This thesis explores the use of linear discriminant analysis in music categorization for the purpose of serving as a cheaper and simpler content-based recommender algorithm. The use of linear discriminant analysis was tested by creating lineardiscriminant functions that classify Wilco’s songs into their respective albums, specifically A.M., Yankee Hotel Foxtrot, and Sky Blue Sky. 4 sample songs were chosen from each album, and song data was …


Incorporating Demographic Structure And Variable Interaction Types Into Community Assembly Models, Akhil Reddy Alasandagutti, Nayan Chawla May 2021

Incorporating Demographic Structure And Variable Interaction Types Into Community Assembly Models, Akhil Reddy Alasandagutti, Nayan Chawla

Honors Theses

Theoretical studies of ecological food webs have allowed ecologists to remove the constraints of specific location and timescales from their study of ecological communities; food webs are generally complex and thus empirical study is difficult. Further, this theoretical approach allows ecologists to compare ecological processes and outcomes across any possible food web structures. However, these simulated communities are only as useful as the model from which they were constructed. Modifying existing considerations in these models, and generating new ones, are the jobs of theoretical ecologists that seek to achieve the shared goal of a majority of simulations: representation of real …


Using Deep Learning To Automate The Diagnosis Of Skin Melanoma, Akhil Reddy Alasandagutti May 2021

Using Deep Learning To Automate The Diagnosis Of Skin Melanoma, Akhil Reddy Alasandagutti

Honors Theses

Machine learning and image processing techniques have been widely implemented in the field of medicine to help accurately diagnose a multitude of medical conditions. The automated diagnosis of skin melanoma is one such instance. However, a majority of the successful machine learning models that have been implemented in the past have used deep learning approaches where only raw image data has been utilized to train machine learning models, such as neural networks. While they have been quite effective at predicting the condition of these lesions, they lack key information about the images, such as clinical data, and features that medical …


Analysis Of Theoretical And Applied Machine Learning Models For Network Intrusion Detection, Jonah Baron May 2021

Analysis Of Theoretical And Applied Machine Learning Models For Network Intrusion Detection, Jonah Baron

Masters Theses & Doctoral Dissertations

Network Intrusion Detection System (IDS) devices play a crucial role in the realm of network security. These systems generate alerts for security analysts by performing signature-based and anomaly-based detection on malicious network traffic. However, there are several challenges when configuring and fine-tuning these IDS devices for high accuracy and precision. Machine learning utilizes a variety of algorithms and unique dataset input to generate models for effective classification. These machine learning techniques can be applied to IDS devices to classify and filter anomalous network traffic. This combination of machine learning and network security provides improved automated network defense by developing highly-optimized …


Evaluating Urban Parks Accessibility And Equity: A Case Study Of Hartford, Ct And New Haven, Ct, Natalie Roach, Mara Tu May 2021

Evaluating Urban Parks Accessibility And Equity: A Case Study Of Hartford, Ct And New Haven, Ct, Natalie Roach, Mara Tu

Honors Scholar Theses

Public parks provide cities with environmental benefits, positive health effects, recreational opportunities, community building, educational spaces, and public amenities. However, certain populations have been systematically denied their fair share of these benefits because of unjust practices in the creation and maintenance of urban parks. With a lens of environmental justice, the goal of this research was to assess park quality and accessibility of two Connecticut cities, Hartford and New Haven, by gathering publicly available information as well as using GIS tools.

The Trust for Public Land (TPL) has an existing ParkScore rating system that evaluates the quality of a city’s …


Climate Change Preparedness In The Insurance Sector, Daniel Fischler May 2021

Climate Change Preparedness In The Insurance Sector, Daniel Fischler

Honors Scholar Theses

Climate change is the inevitable consequence of human activity since the industrial revolution began centuries ago. Assuming humanity survives and adapts to this scenario, there will be significant impacts on the economy and business. Under these circumstances, the insurance sector in particular will face challenges as the frequency and severity of losses increase due to climate change related events. This paper aims to analyze various options for allowing insurance to maintain viability in this changing environment. The general issue for the future is premiums must be commensurate with climate change related risk in affected areas. As a result, certain coastal …


Assessing The Impact Of Vaccination And Behavior Change On Outbreaks Of Emerging Respiratory Diseases, Mohammed Hameed Alharbi May 2021

Assessing The Impact Of Vaccination And Behavior Change On Outbreaks Of Emerging Respiratory Diseases, Mohammed Hameed Alharbi

Mathematics Dissertations

The purpose of this dissertation is to use mathematical models to evaluate the impact of characteristics of respiratory diseases like influenza and COVID-19 either alone or co-circulating and how might influenza vaccine affect this interplay. First, we assess the effects of matching and mismatching between vaccine strains and circulating strains during the Hajj. Then we evaluate the impact of the proportion of asymptomatic COVID- 19 infections on the magnitude of an epidemic under three different behavior change scenarios. Finally, we model the co-circulation of influenza and COVID-19 to investigate whether the influenza vaccine increases the combined disease burden of influenza …


Some Quadratic Quantum P³S With A Linear One-Dimensional Line Scheme, Ian Christopher Lim May 2021

Some Quadratic Quantum P³S With A Linear One-Dimensional Line Scheme, Ian Christopher Lim

Mathematics Dissertations

It is believed that quadratic Artin-Shelter regular (AS-regular) algebras of global dimension four (sometimes called quadratic quantum P3s can be classified using a geometry similar to that developed in the 1980’s by Artin, Tate, and Van den Bergh. Their geometry involved studying a scheme (later called the point scheme) that parametrizes the point modules over a graded algebra. The notion of line scheme (which parametrizes line modules) was introduced later by Shelton and Vancliff. It is known that “generic” quadratic quantum P3s have a finite point scheme and one-dimensional line scheme. A family of algebras with these properties is presented …