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Implementation Of Unscented Kalman Filter-Based State Estimation For Multiple Spacecraft Using Global Positioning System Measurements, Bala Prenith Reddy Gopu May 2025

Implementation Of Unscented Kalman Filter-Based State Estimation For Multiple Spacecraft Using Global Positioning System Measurements, Bala Prenith Reddy Gopu

Theses and Dissertations

This study presents an implementation of state estimation for a drag-based rendezvous mission involving multiple chaser spacecraft and a single target, using Unscented Kalman Filtering (UKF) with Global Positioning System (GPS) measurements. The implemented method combines GPS navigation solutions with UKF to provide real- time state estimates of all spacecraft involved. Nonlinear least squares method is employed to process pseudorange and pseudorange rate measurements to determine receiver states, UKF utilizes these states as measurements to estimate absolute space- craft positions and velocities. This implementation also addresses practical challenges including raw GPS measurement processing, and varying GPS satellite geometries.


C-Band Air To Ground Communication System For Uav, Mubark Alghamdi May 2025

C-Band Air To Ground Communication System For Uav, Mubark Alghamdi

Theses and Dissertations

C band spectrum 5030-5091 MHz is allocated for command-and-control communication services with unmanned aircraft systems. This document evaluates the possibility of using 3GPP 5G standards for provisioning of such services. Channelization of the spectrum and major system parameters are proposed. The performance of the proposed system in channel fading environment is evaluated using MATLAB based simulations. The evaluations examine SINR, and average throughput of the proposed system at different altitudes of the unmanned aircraft system. MATLAB simulations are used to evaluate system performance in free-space environments. Signal-to-Interference-plus-Noise Ratio (SINR) and Reference Signal Received Power (RSRP) are predicted at different UAS …


The Impact Of System Transparency On Perceived System Reliability, Perceived System Usability, And Information Clarity In Self-Driving Car Systems, Uditkumar Nair May 2025

The Impact Of System Transparency On Perceived System Reliability, Perceived System Usability, And Information Clarity In Self-Driving Car Systems, Uditkumar Nair

Theses and Dissertations

In human-computer interaction (HCI), the development of autonomous vehicle (AV) technology has created new difficulties, especially in building user confidence as well as understanding of system functioning. The effect of system transparency on user- centered outcomes, such as perceived usability, perceived system reliability, and information clarity, is examined in this thesis. In order to evaluate their experiences in both ordinary and high-stakes driving situations, participants engaged with both system- transparent user interfaces (TUIs) and non-transparent user interfaces (NTUIs) across a number of experimental scenarios. In order to assess how well each interface conveyed system logic and actions, the study included …


Developing End-To-End Imitation Learning For Asteroid Proximity Operations, Patrick David Quinn May 2025

Developing End-To-End Imitation Learning For Asteroid Proximity Operations, Patrick David Quinn

Theses and Dissertations

Asteroid exploration remains a popular topic in the scientific community, however hurdles still exist for controlling spacecraft within the asteroid environment. Communication delays often require the usage of limited onboard computing hardware for navigation. Additionally, long mission timelines must be accommodated with highly efficient fuel use. Considering these issues, it is apparent that any guidance, navigation, and control (GNC) system in these spacecraft should emphasize both computational and fuel efficiency in its design. Furthermore, the integration of a robust state estimation system is necessary for the successful deployment of such systems. The development of a controller aiming to address these …


Patterns Of Fire History And Vegetation Changes In The Last 5000 Years: A Paleoecological Study Of Iquitos, Annabel Zwarts May 2025

Patterns Of Fire History And Vegetation Changes In The Last 5000 Years: A Paleoecological Study Of Iquitos, Annabel Zwarts

Theses and Dissertations

The vegetation of the Amazonian rainforest is hypothesized to have been shaped by pre-Columbian activities, such as burning and palm management to various extents. Management of palms is hypothesized to have caused some of the most useful species to become hyperdominant in Amazonia. This study investigated the extent to which human activities over the past 5000 years affected palm abundances in mature lowland rainforests near Iquitos, Peru. I used phytoliths and charcoal from soil cores to determine the history of local floras, and modern palm surveys to compare modern phytolith occurrence with modern vegetation. Because pre-Columbian activity clustered along the …


Towards Visual Inertial Navigation With Fixed Tetrahedral Targets, Joao Leonardo Silva Cotta May 2025

Towards Visual Inertial Navigation With Fixed Tetrahedral Targets, Joao Leonardo Silva Cotta

Theses and Dissertations

This dissertation presents a robust method for 6DoF position estimation under impaired visual conditions utilizing a minimum 4-point Perspective-n-Point (P4P) solver designed for tetrahedral targets. Using SO(3) × R 3 instead of SE(3), the method uses a Lie group-based formulation to discriminate between rotation and translation, thereby enabling computationally efficient, resource-conscious op- optimization while preserving correct geometric behavior. Designed using the contemporary C++17 library ShomerTarget, the solver is analytically formulated and assessed under pragmatic robotic conditions. Particularly in low-light and high-dynamic environments, experiments on embedded systems, UAVs, and NASA’s Astrobee show that the proposed solver attains enhanced accuracy compared to …


Mixed-Mode Fracture Analysis Of Additively Manufactured Periodic Orthotropic Functionally Graded Microcellular Materials, Behnam Shahbazian May 2025

Mixed-Mode Fracture Analysis Of Additively Manufactured Periodic Orthotropic Functionally Graded Microcellular Materials, Behnam Shahbazian

Theses and Dissertations

The quest for safety, efficiency, and innovation in aerospace engineering demands a relentless focus on understanding how materials and structures behave under extreme and complicated loading conditions. Among the many challenges faced by engineers in this field, predicting and preventing structural failure stands out as both a fundamental necessity and a complex problem. Fracture mechanics, the science of how materials fail under stress, is a cornerstone of this effort. Whether it is the fuselage of an aircraft enduring cyclic loading or the lightweight components of a spacecraft resisting impact, the ability to accurately predict fracture behavior directly influences the reliability …


Experimental And Theoretical Fracture Analysis Of Rift Manufactured Carbon Fiber-Vinyl Ester Lamina, Daniel Joseph Longo May 2025

Experimental And Theoretical Fracture Analysis Of Rift Manufactured Carbon Fiber-Vinyl Ester Lamina, Daniel Joseph Longo

Theses and Dissertations

This thesis investigates the fracture behavior of unidirectional carbon fiber-vinyl ester (CFVE) laminates manufactured using the Resin Infusion with Flexible Tooling (RIFT) process, a cost-effective alternative to autoclave-based fabrication methods. Composite materials like CFVE are increasingly adopted in high-performance applications due to their high strength-to-weight ratio and corrosion resistance; however, their anisotropic nature presents challenges in predicting crack initiation and propagation. To address this, a comprehensive approach combining experimental testing, finite element modeling (FEM), and classical fracture mechanics was employed. Orthotropic mechanical properties were first determined through tensile and shear tests, providing critical properties for FEM simulations. A series of …


Use Of Pushed-In Pencel Pressuremeter Test For Shallow Foundation Design In Florida Fine Sands, Brhane Weldeanenya Ygzaw May 2025

Use Of Pushed-In Pencel Pressuremeter Test For Shallow Foundation Design In Florida Fine Sands, Brhane Weldeanenya Ygzaw

Theses and Dissertations

A comprehensive evaluation was conducted on the performance, consistency, and practical application of various in-situ geotechnical testing methods for predicting the settlement and bearing capacity of shallow foundations in Florida’s fine sands. The methods assessed include the Standard Penetration Test (SPT), Cone Penetration Test (CPT), Dilatometer Test (DMT), pushed-in PENCEL Pressuremeter Test (PPMT), and the pre-bored TEXAM Pressuremeter Test. A dual approach controlled indoor testing at the FDOT State Materials Office (SMO) and field investigations at three representative sites (Kingsley, Trenton, and the UCF research site), formed the experimental foundation.

Over thirty settlement prediction techniques and thirteen bearing capacity estimation …


Effects Of Reflective Journaling And Nudges On Academic Motivation And Engagement, Lakshmi Satya Sai Veda Mahita Uppuluri May 2025

Effects Of Reflective Journaling And Nudges On Academic Motivation And Engagement, Lakshmi Satya Sai Veda Mahita Uppuluri

Theses and Dissertations

This study investigates the effects of reflective journaling and motivational nudges on academic motivation and engagement among college students. Grounded in Self- Determination Theory (SDT), the research examines how different interventions influence intrinsic motivation, and academic behaviors such as class attendance, participation, and preparation. The study employed a between-group experimental design with three conditions: a control group, a journaling group, and a journaling group that also received daily motivational nudges. Results showed that students in the journaling groups—particularly those who received nudges—experienced a significant increase in academic motivation. While changes in academic engagement were not significant, the effect size suggested …


Stochastic Analysis With Operational Calculus In Reliability, Hend Hamdan Al-Jahani May 2025

Stochastic Analysis With Operational Calculus In Reliability, Hend Hamdan Al-Jahani

Theses and Dissertations

Our dissertation models several reliability systems subject to occasional random shocks of random magnitudes W1,W2,..occurring at times tau0, tau2,..In Model 1, the underlying system becomes inoperational if it wears out due to aging specified by a monotone increasing continuous function Delta identifying system's wear at any time t>=0 . The system is deemed inoperational if delta crosses a sustainability threshold at some moment T=(delta )^-1(D). The precise time T is difficult to identify making the realistic failure time randomly delayed and thus identified at some opportune observation epoch. The system can also fail due to damages by external shocks, …


The Prototype Of A Fully Automated Pressuremeter For Various Geotechnical Applications, Anuar Akchurin May 2025

The Prototype Of A Fully Automated Pressuremeter For Various Geotechnical Applications, Anuar Akchurin

Theses and Dissertations

The geotechnical engineering field requires high-quality in-situ testing equipment that ensures consistency in the test execution. This research focuses on developing and testing a prototype of a fully automated pressuremeter control unit to allow the industry to obtain reliable and controlled stress-strain data, thereby improving efficiency and reducing testing time.

The objectives of this work are to design and develop a system with the necessary components to perform the pressuremeter test, integrate the testing procedure into the state machine design, enable automated testing, and validate the results by comparing the stress-strain data with that obtained from the existing hand-operated pressuremeter …


Alternative Robust Design Formulation And Exploration Strategies For Managing Uncertainties In The Realization Of Complex Engineering Systems, Pooja Mukundan May 2025

Alternative Robust Design Formulation And Exploration Strategies For Managing Uncertainties In The Realization Of Complex Engineering Systems, Pooja Mukundan

Theses and Dissertations

The design of complex engineered systems often relies on simulation-based models, which inherently introduce uncertainties. Managing these uncertainties is critical to ensure robust system performance. From a decision-based design (DBD) perspective, robust design metrics such as the Design Capability Index (DCI) and Error Margin Index (EMI) are employed to formulate and solve problems under uncertainty. However, existing formulations of these metrics rely on first-order Taylor series approximations for variance estimation, which are often inadequate in the presence of highly nonlinear or multimodal performance functions.

This thesis proposes alternate formulations of DCI and EMI, which use the multiple-point method of variance …


Trends In And Factors Associated With Science Achievement Among Fourth Graders In Saudi Arabia: A Secondary Analysis Of Timss Data, Reda Massawe May 2025

Trends In And Factors Associated With Science Achievement Among Fourth Graders In Saudi Arabia: A Secondary Analysis Of Timss Data, Reda Massawe

Theses and Dissertations

This secondary analysis examined trends and factors associated with science achievement among fourth-grade students in Saudi Arabia using data from the Trends in International Mathematics and Science Study (TIMSS). Between 2007 and 2019, Saudi students consistently scored below the international average in science, with female students outperforming males by more than 30 points. The study addressed two issues: (1) reasons behind Saudi students’ underperformance and (2) limited research on contributing factors. TIMSS data from 2011, 2015, and 2019 were analyzed using descriptive, correlational, and regression methods. While trends across the years were explored, only 2019 data were used for detailed …


Trends In And Factors Associated With Science Achievement Among Eighth Graders In Saudi Arabia: A Secondary Analysis Of Timss Data, Roba Alzahrani May 2025

Trends In And Factors Associated With Science Achievement Among Eighth Graders In Saudi Arabia: A Secondary Analysis Of Timss Data, Roba Alzahrani

Theses and Dissertations

This secondary analysis examined trends in and factors influencing science achievement among eighth-grade students in Saudi Arabia, using data from the Trends in International Mathematics and Science Study (TIMSS). However, Saudi Arabia's performance on the TIMSS science assessments fell below the international average, from 2003 through 2019. In addition, gender differences in science achievement have been observed, with female students outperforming male students by 30 or more points. This study addresses two problems: factors associated with the lower performance of Saudi students on TIMSS science assessments compared to global standards, and the small number of studies which explored factors which …


Exploratory Study On Factors That Impact Job Embeddedness For Northeast Government And Commercial Aerospace Procurement Specialists, Nicholas Alaimo May 2025

Exploratory Study On Factors That Impact Job Embeddedness For Northeast Government And Commercial Aerospace Procurement Specialists, Nicholas Alaimo

Theses and Dissertations

This qualitative study examined job embeddedness theory and its impact on commercial and government aerospace procurement professionals in the Northeast United States. The research sought to understand the factors that influence why these professionals remain in their positions and what elements contribute to improved job performance. Job embeddedness theory explains employee retention through three key factors: perceived fit within their role, perceived links to organizational culture, and perceived sacrifices that would result from leaving.

The study identified six main themes. First, the research found both similarities and differences in how aerospace procurement specialists connect with aerospace culture in government subcontracting …


Fpso Motion In Synthetic Environments: Stereo-Driven Deep Learning For Wavefield Reconstruction, Motion Analysis, And Mooring System Assessment, Omar Jebari May 2025

Fpso Motion In Synthetic Environments: Stereo-Driven Deep Learning For Wavefield Reconstruction, Motion Analysis, And Mooring System Assessment, Omar Jebari

Theses and Dissertations

This dissertation presents an integrated synthetic environment for simulating the motion and monitoring the integrity of a moored Floating Production Storage and Offloading (FPSO) vessel. The central hypothesis is that synthetic data-driven approaches can (1) accurately estimate spatio-temporal wave fields, (2) predict vessel motion, and (3) monitor the integrity of the mooring system—using stereo imagery of the wave field and structure motion, both of which can be acquired in real time. The first study develops a synthetic framework for estimating spatial wave fields using stereo images captured by dual cameras mounted on a moving FPSO. Dynamic sea states and vessel …


Co-Designing Manufacturing Systems For Robustness And Resilience: A Decision-Based Design Perspective, Mathew Baby May 2025

Co-Designing Manufacturing Systems For Robustness And Resilience: A Decision-Based Design Perspective, Mathew Baby

Theses and Dissertations

Manufacturing systems (MSs) comprise various stakeholders associated with the manufacture and supply of products required by customers and are interrelated by the flow of materials and information. The interrelated stakeholders make system-specific decisions and stakeholder-specific decisions across multiple levels of a decision hierarchy to satisfy many conflicting system-specific and stakeholder-specific requirements that define system and stakeholder performances. Given the stakeholder interrelations and conflicting nature of system-specific and stakeholder-specific requirements, system and stakeholder performances are correlated and conflicting.

In the Industry 5.0 era, there is an increased emphasis on the creation and equitable distribution of value among all the stakeholders in …


Personality Trait Recognition Through Deep Neural Temporal Modeling Of Non-Verbal Behavior, Kushal Vangara May 2025

Personality Trait Recognition Through Deep Neural Temporal Modeling Of Non-Verbal Behavior, Kushal Vangara

Theses and Dissertations

Personality research seeks to explain the wide range of human behaviors through stable, measurable traits. Human interactions are inherently rich and multidimensional, and analyzing behavioral data offers a promising path to uncover personality insights. The increasing convergence of psychology, computer science, and machine learning has fueled interest in computational approaches to personality assessment. Advances in sensing technologies have made it possible to capture fine-grained information about individuals’ behaviors and interactions in naturalistic and controlled environments. Automated audio-visual analysis techniques extract relevant behavioral cues, which machine learning models then interpret to infer underlying personality traits. This work provides a comprehensive overview …


How Will Artificial Intelligence Impact The Roles, Skills, And Design Processes Of Ux Professionals In The Next 5 Years?, Olivia Behan May 2025

How Will Artificial Intelligence Impact The Roles, Skills, And Design Processes Of Ux Professionals In The Next 5 Years?, Olivia Behan

Informatics

Artificial intelligence (AI) is changing the way we think about user experience (UX) design. This thesis explores how AI could impact the roles, skills, and design processes of UX professionals over the next five years. The research conducted consists of a mixed-methods approach, combining an online survey administered through Qualtrics to 50 survey respondents and a case study, which included individually interviewing 3 UX professionals over Zoom, to gather data and personal insights. The results show that while AI has the power and potential to make some parts of UX work faster, like research analysis, prototyping, and automating redundant tasks, …


Aircraft Water And Waste Systems Curriculum Alignment For Updated Airmen Certificate Standards (Acs), Myles Miller May 2025

Aircraft Water And Waste Systems Curriculum Alignment For Updated Airmen Certificate Standards (Acs), Myles Miller

All Graduate Reports and Creative Projects, Fall 2023 to Present

The purpose of this project was to create a curriculum that aligns with the updated Airmen Certificate Standards (ACS) related to aircraft water and waste systems. The curriculum was designed to align with the FAA standards outlined in the ACS section II. Airframe Subject O. Water and Waste Systems. The curriculum includes components, operation, inspection, and servicing requirements for potable water and lavatory waste systems. The curriculum should equip students with the ability to identify, assess, and mitigate risks associated with lavatory waste systems, and the ability to locate and explain the procedures for servicing water and waste systems. The …


Reflections On Teaching Language And Culture In The French Dual Language Immersion Classroom, Aminata Sylla May 2025

Reflections On Teaching Language And Culture In The French Dual Language Immersion Classroom, Aminata Sylla

All Graduate Reports and Creative Projects, Fall 2023 to Present

This portfolio is representative of the author’s work in the Masters in Second Language Teaching (MSLT) program and classroom experience. The reflection paper explores teaching French in the Dual Language Immersion (DLI) and Bridge secondary education context and evaluates specific examples of innovative teaching. The aims of this reflection are twofold: first, to reflect on how the author improved her teaching effectiveness through this experience and through the USU MSLT program; second, to suggest best practices in the French DLI classroom. Both practical and theoretical, the reflection focuses on the author’s own experiences teaching Bridge program intermediate and advanced-proficiency level …


Bomb Calorimeter As Proof Of Concept For Low-Cost Calorimeter To Measure Thermal Runaway In Pouch Cells To Facilitate Statistical Characterization, Mykell Johnson May 2025

Bomb Calorimeter As Proof Of Concept For Low-Cost Calorimeter To Measure Thermal Runaway In Pouch Cells To Facilitate Statistical Characterization, Mykell Johnson

All Graduate Reports and Creative Projects, Fall 2023 to Present

Transportation is becoming increasingly electrified, with the main energy storage system being lithium-ion (li-ion) batteries. Despite the widespread adoption of li-ion batteries, unique design abuse tolerance concerns need to be addressed, specifically regarding the catastrophic exothermic release of energy, called thermal runaway (TR). While TR is a major design consideration in all li-ion applications, it presents unique difficulties in the electric aviation industry. The Federal Aviation Administration (FAA) considers thermal runaway inevitable in a battery pack and requires containment of the event per DO311-A for certified aircraft. Due to the wide variability of TR, designing for this phenomenon can be …


“Floptok Is Not A Trend. It’S A Lifestyle”: Camp, Performativity, And Community Dynamics In An Adolescent Tiktok Subculture, Drake Hansen May 2025

“Floptok Is Not A Trend. It’S A Lifestyle”: Camp, Performativity, And Community Dynamics In An Adolescent Tiktok Subculture, Drake Hansen

All Graduate Reports and Creative Projects, Fall 2023 to Present

Floptok is an online meme-sharing community or subculture that began to take shape in 2021, united by a particular sensibility and set of memetic materials. To outsiders, Floptok is seen as a loud, brash, and often abrasive community whose memes, characterized by low-quality audio and video, often feature “icons”—a range of invented characters and real people—and audio of pop songs heavily edited to feature hypersexual lyrics from the rapper CupcakKe, as well as portions of the 2019 Chinese pop song “Yěhuāxiāng.” This thesis built on scholarship in digital and young people’s folklore in an ethnographic case study of Floptok’s humor …


Research Participant Interest In Learning Results Of Biomarker Tests For Alzheimer Disease, Spondita Goswami, Sarah M Hartz, Amy Oliver, Sacha Jackson, Tomi Ogungbenle, Alissa Evans, Erin Linnenbringer, Krista L Moulder, John C Morris, Jessica Mozersky May 2025

Research Participant Interest In Learning Results Of Biomarker Tests For Alzheimer Disease, Spondita Goswami, Sarah M Hartz, Amy Oliver, Sacha Jackson, Tomi Ogungbenle, Alissa Evans, Erin Linnenbringer, Krista L Moulder, John C Morris, Jessica Mozersky

2020-Current year OA Pubs

IMPORTANCE: While available evidence suggests there are not major psychosocial harms of return of research results, there are limited data on uptake of Alzheimer disease (AD) research results or reasons for declining to learn results among participants in AD research studies.

OBJECTIVES: To quantitatively and qualitatively evaluate who declines to learn individual AD biomarker research results and what factors are associated with the decision.

DESIGN, SETTING, AND PARTICIPANTS: This observational cohort study was conducted between November 1, 2020, and April 15, 2024, among participants aged 65 years or older with unimpaired cognition and available biomarker data (apolipoprotein E genotype and …


Brain Morphometry In Infants Later Diagnosed With Autism Is Related To Later Language Skills, Luke E Moraglia, Kelly N Botteron, Natasha Marrus, Et Al. May 2025

Brain Morphometry In Infants Later Diagnosed With Autism Is Related To Later Language Skills, Luke E Moraglia, Kelly N Botteron, Natasha Marrus, Et Al.

2020-Current year OA Pubs

Autism spectrum disorder (ASD) presents early in life with distinct social and language differences. This study explores the association between infant brain morphometry and language abilities using an infant-sibling design. Participants included infants who had an older sibling with autism (high likelihood, HL) who were later diagnosed with autism (HL-ASD; n = 31) and two non-autistic control groups: HL-Neg (HL infants not diagnosed with autism; n = 126) and LL-Neg (typically developing infants who did not have an older sibling with autism; n = 77). Using a whole-brain approach, we measured cortical thickness and surface area at 6 and 12 …


A Comparison Of Carbon Ions Versus Protons For Integrated Mode Ion Imaging, Mikaël Simard, Ryan Fullarton, Lennart Volz, Christoph Schuy, Daniel G Robertson, Colin Baker, Christian Graeff, Charles-Antoine Collins Fekete May 2025

A Comparison Of Carbon Ions Versus Protons For Integrated Mode Ion Imaging, Mikaël Simard, Ryan Fullarton, Lennart Volz, Christoph Schuy, Daniel G Robertson, Colin Baker, Christian Graeff, Charles-Antoine Collins Fekete

Faculty, Staff and Student Publications

Background: Incorporating image guidance into ion beam therapy is critical for minimizing beam range uncertainties and realizing the modality's potential. One promising avenue for image guidance is to capture transmission ion radiographs (iRads) before and/or during treatment. iRad image quality is typically maximized using a single-event imaging system, which involves tracking individual ions, albeit the approach is generally not suited to clinical beam settings. An alternative faster and clinically compatible method is integrated mode imaging, where individual pencil beam data is acquired, rather than single ion data. To evaluate the usefulness of transmission ion imaging for image guidance, it is …


From Epithelium To Therapy: Transitional Cells In Lung Fibrosis, Sarah Y Shin, Jichao Chen, Irit Milman Krentsis, Yair Reisner, Rodeo Abrencillo, Danielle Wu May 2025

From Epithelium To Therapy: Transitional Cells In Lung Fibrosis, Sarah Y Shin, Jichao Chen, Irit Milman Krentsis, Yair Reisner, Rodeo Abrencillo, Danielle Wu

Faculty, Staff and Student Publications

Patients with idiopathic pulmonary fibrosis and lung fibrosis secondary to infections such as influenza A and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have limited treatment options outside of supportive therapy and lung transplantation. Multiple lung stem cell populations have been implicated in the pathogenesis of lung fibrosis, and more progenitor cell populations continue to be discovered and characterized. In this review, we summarize the functions and differentiation pathways of various cells that constitute the lung epithelium. We then focus on two subpopulations of KRT5


Rna Sculpting By The Primordial Helix-Clasp-Helix-Strand-Loop (Hch-Sl) Motif Enforces Chemical Recognition Enabling Diverse Kh Domain Functions, John A Tainer, Susan E Tsutakawa May 2025

Rna Sculpting By The Primordial Helix-Clasp-Helix-Strand-Loop (Hch-Sl) Motif Enforces Chemical Recognition Enabling Diverse Kh Domain Functions, John A Tainer, Susan E Tsutakawa

Faculty, Staff and Student Publications

In all domains of life, the ancient K homology (KH) domain superfamily is central to RNA processes including splicing, transcription, posttranscriptional gene regulation, signaling, and translation. Proteins with 1 to 15 KH domains bind single-strand (ss) RNA or DNA with base sequence specificity. Here, we examine over 40 KH domain experimental structures in complex with nucleic acid (NA) and define a novel Helix-clasp-Helix-Strand-Loop (HcH-SL) NA recognition motif binding 4 to 5 nucleotides using 10 to 18 residues. HcH-SL includes and extends the Gly-X-X-Gly (GXXG) signature sequence "clasp" that brings together two helices as an ∼90° helical corner. The first helix …


Quantifying Photon Counting Detector (Pcd) Performance Using Pcd-Ct Images, Linying Zhan, Guang-Hong Chen, Ke Li May 2025

Quantifying Photon Counting Detector (Pcd) Performance Using Pcd-Ct Images, Linying Zhan, Guang-Hong Chen, Ke Li

Faculty, Staff and Student Publications

Background: Photon counting detector CTs (PCD-CTs) have recently been introduced to clinical imaging. This development creates a new need for end-users to quantify and monitor the physical performance of PCDs. Traditionally, the characterization of PCD performance relied on detector counts, which are typically accessible to the manufacturer but are not usually available to clinical end-users.

Purpose: The goal of this work was to develop a new method for quantifying PCD performance using reconstructed PCD-CT images, without requiring access to the PCD counts.

Methods: The proposed method is based on a set of closed-form relationships that connect PCD-CT image noise, the …