Digital Commons Network^™

Single-Cell Transcriptomics Of The Drosophila Ring Gland Identifies The Soxn–Vvl Complex As A Key Regulator Of Juvenile Hormone Biosynthesis, Yuhan Luo, Nan Chen, Yue Gao, Wei Luo, Shanshan Liu, Yang Li, Hanyue Wang, Xiangbin Gao, Jiawei Chen, Haosheng Ye, Kirst King-Jones, Subba Reddy Palli, Sheng Li, Suning Liu

Entomology Faculty Publications

Juvenile hormone (JH) is essential for maintaining juvenile status and promoting reproduction in insects, yet the transcriptional regulation of JH biosynthesis remains poorly understood. Previous transcriptomic studies of the Drosophila ring gland—which is composed of the corpus allatum (CA), prothoracic gland (PG), and corpora cardiaca (CC)—have treated the ring gland as a single tissue. As a result, these approaches lacked the resolution necessary to dissect JH biosynthesis and its regulation in a cell-type-specific manner. To overcome this limitation, we performed single-cell RNA sequencing (scRNA-seq) of 7,919 cells isolated from the larval ring glands. This analysis resolved distinct transcriptional profiles for …

Interannual Variation In Seed Traits Of Cedrela Species, Guadalupe Galíndez, Ana Álvarez, Diana Ceccato, Victoria Rivero, Gisela Malagrina, Tania Bertuzzi, Pablo Saravia, Stavros Nicolás Sola, Carol C. Baskin, Luis Fornes

Plant and Soil Sciences Faculty Publications

Climate change is altering temperature and precipitation regimes in Argentina, with potential consequences for regeneration and persistence of forest tree species, emphasizing the importance of ex situ seed conservation. We evaluated interannual variation in seed traits, desiccation tolerance, storage behavior, and longevity of Cedrela balansae C. DC. and C. fissilis Vell. (Meliaceae), two endangered native species of subtropical rainforests in Argentina. Both species produced desiccation-tolerant seeds, independently of collection year, seed traits, or climatic conditions. Depending on the species, seed traits and longevity varied across years and showed strong relationships with temperature and precipitation, particularly during seed development. Cedrela balansae …

Post-Translational Control Of Biotic Stress-Related Nicotine Biosynthesis By A Map Kinase Signaling Cascade, Yan Zhou, Yongliang Liu, Ruiqing Lyu, Sanjay Kumar Singh, Xueyi Sui, Xin Hou, Sitakanta Pattanaik, Ling Yuan

Plant and Soil Sciences Faculty Publications

The evolutionarily conserved mitogen-activated protein kinase (MAPK) cascades relay extracellular signals into cells, triggering a variety of cellular responses. We previously revealed NtMPK4 as a positive regulator of nicotine biosynthesis; however, its upstream regulation remains unclear. Here, we characterized a MAPK cascade, comprising NtMEKK1b, NtMPKK2a, and NtMPK4, that promotes nicotine biosynthesis. This signaling module transduces external cues, including jasmonate and pathogen elicitors such as flg22, into post-translational modifications that enhance transcriptional activity and pathway gene expression. NtMPKK2a physically interacts with and phosphorylates NtMPK4 in vivo, confirming its role as an upstream kinase. RNAi-mediated silencing of NtMPKK2a significantly reduced the expression …

Association Of Clinical Severity In Autism Spectrum Disorder With Biomolecules Involved In Lipid Metabolism, Inflammation And Mirnas, Maria Gevezova, Michael Maes, Iliana Pacheva, Nikolay Mehterov, Zdravko Ivanov, Elena Timova, Stefka Spassieva, Erhard Bieberich, Maria Kazakova, Ivan Ivanov, Victoria Sarafian

Markey Cancer Center Faculty Publications

Autism spectrum disorder (ASD) is a heterogeneous neurological condition with an unclear etiology and pathogenesis. In recent years, studies have identified changes in lipid metabolism, inflammation, mitochondrial dysfunction, and mitophagy in patients with ASD. However, the specific interactions between these molecular signatures and their clinical applications in ASD remain largely unexplored. The aim of our study is to search for correlations between changes in gene and miRNA expression and the clinical characteristics of ASD. The investigation included a cohort of children with idiopathic ASD and healthy controls (HC). Diagnosis was established based on ADOS assessment (autism diagnostic observation schedule). Gene …

The American College Of Radiology Diagnostic Fluoroscopy Dose Index Registry Pilot, Steve D. Mann, Donald L. Miller, Grant Fong, Allen R. Goode, Emily L. Marshall, Thomas Nishino, Pavlina Boxx, Liqiang Ren, Celalettin Topbas, Alan H. Schoenfeld, Vivek Singh, Jie Zhang

Radiology Faculty Publications

Background: The ACR Diagnostic Fluoroscopy Dose Index Registry (DIR-Fluoro) is expanding to include diagnostic fluoroscopy. Variations in dose reference points and overhead radiography events may introduce unique challenges for benchmarking. Purpose: To survey the technological status and dosimetric performance of fluoroscopes participating in the DIR-Fluoro pilot project, focusing on longitudinal stability and variability of fluoroscopic dose reporting accuracy across multiple institutions and vendors. Methods: Sixty-six fluoroscopic systems from nine institutions (24 facilities) were surveyed for facility type, fluoroscope type, image receptor type, age, dose reporting capabilities, and other key features. Of these, 56 were evaluable. Semi-annual measurements assessed reference air …

Toward An Emerging Public Health Paradigm, Rod Wallace, Katherine Frels, Maria Itria Ibba, Conrad Lyford, Devin Rose, David Baltensperger, Jan A. Delcour, Steven Greenspan, Alison Lovegrove, Barbara Schneeman, Peter Shewry, Edward Souza, William W. Wilson, Gary W. Yohe, Jim Anderson, George Annor, Jayne Bock, Claudia Carter, Brett Carver, Jianli Chen, Edward C. Deehan, Noah Dewitt, Lisa Diewald, Jason Donovan, Corrine K. Hanson, David Holding, Amir Ibrahim, Mariah Jackson

Animal and Food Sciences Faculty Publications

An emerging paradigm in public health focuses on enhancing nutrition in existing food staples to reduce chronic disease at the population scale, rather than relying on individuals to change their behavior. This paradigm leverages plant and animal breeding, production practices, and processing to enhance nutrition, whereby foods consumed by millions can be improved at low incremental cost. This article supports and operationalizes this paradigm, illustrating the potential to improve diets through a case study that increases the arabinoxylan fiber content of commodity wheat through classical plant breeding (a non-GMO technology). The approach described in this article proposes to link agricultural …

Kentucky Cdl Adjudication Pilot And Compliance Needs Study, Jeeyen Koo, Andrew Martin, Jennifer Walton

Kentucky Transportation Center Research Report

This report examines trends in how Kentucky District Courts have adjudicated charges related to commercial driver’s license (CDL) and commercial motor vehicles (CMVs). Using court data, researchers evaluated historical patterns in charge filing volumes as well as conviction, dismissal, amendment, and diversion rates. Between 2002 and 2024, conviction rates declined and dismissals increased. Convictions peaked in the mid-70% range in the early 2000s, but fell to the mid-50% range by 2024. Speeding and other serious traffic violations — many of which are advanceable offenses — were dismissed or amended at rates that could have substantively affected the integrity of CDL …

Sustained Increase In Extracellular Atp In The Lung Induced By Chronic Inhalation Exposure To Nitrogen Dioxide, Nai Ju Chan, Yueh Yin Chen, Chun Chun Hsu, You Shuei Lin, Maxwell Zakeri, Mehdi Khosravi, Lu Yuan Lee

Physiology Faculty Publications

Nitrogen dioxide (NO₂) is an environmental air pollutant and a potent oxidant. Epidemiological studies have revealed a close association between chronic cough and long-term inhalation exposure to NO₂. ATP can be released from airway/lung epithelial cells upon inhalation exposure to oxidants, and convincing evidence established in recent clinical studies indicated that extracellular ATP in the respiratory tract plays an important role in the pathogenesis of refractory chronic cough. However, whether inhalation exposure to NO₂ elevates the ATP release in the lung is not yet known. Results of this study showed: 1) in awake rats, acute …

Impact Of Grain Size On Low-Temperature Carrier Phase Coherence Length In Polycrystalline Halide Perovskite Films, Aungkan Sen, Liam J. Scanlon, Axel Melchor Gaona Carranza, Jose L. Mendoza-Cortes, Johannes Pollanen, Richard R. Lunt, William J. Gannon

Physics and Astronomy Faculty Publications

Halide perovskites are now being studied for a full range of optoelectronic devices due to their excellent electronic and optical properties. This work explores the impact of grain boundaries on low-temperature carrier transport in polycrystalline cesium tin iodide (CsSnI₃) within the quantum diffusive transport regime, comparing a range of polycrystalline samples with varying grain sizes with epitaxial counterparts. Low-temperature magnetoresistance measurements reveal the presence of weak anti-localization (spin-orbit effects) with a shorter coherence length (L_ϕ) than the epitaxial films. Surprisingly, L_ϕ is not found to be impacted by grain size, despite being nearly an order …

Study Of Clustering Technique And Communication Topologies For Cooperative Control-Based Volt-Var Optimization, Gaurav Yadav, Yuan Liao, Dan M. Ionel

Electrical and Computer Engineering Faculty Publications

Introducing renewable distributed generation (DG) in the power distribution system causes rapid voltage fluctuations due to its intermittency. This intermittency renders conventional voltage regulation devices such as on-load tap changers (OLTCs) and capacitor banks (CBs) inefficient to regulate rapid voltage changes and leads to reduced equipment lifetime and high operation and maintenance costs. Hence, this calls for non-conventional methods to mitigate such voltage fluctuations. This paper presents a cooperative control-based method aimed to optimally control the reactive power of DG inverters to mitigate the voltage deviations by establishing communication among the DG nodes, and between DG and non-DG nodes. This …

Electromagnetic Formation Flying Using Alternating Magnetic Field Forces And Control Barrier Functions For State And Input Constraints, Sumit Suryakant Kamat, Thomas Michael Seigler, Jesse B. Hoagg

Mechanical Engineering Faculty Publications

This article presents a feedback control algorithm for electromagnetic formation flying with constraints on the satellites’ states and control inputs. The algorithm combines several key techniques. First, we use alternating magnetic field forces to decouple the electromagnetic forces between each pair of satellites in the formation. Each satellite’s electromagnetic actuation system is driven by a sum of amplitude-modulated sinusoids, where amplitudes are controlled in order to prescribe the time-averaged force between each pair of satellites. Next, the desired time-averaged force is computed from an optimal control that satisfies state constraints (i.e., no collisions and an upper limit on intersatellite speeds) …

Leadership And Creative Placemaking In Central Appalachia: Morehead, Kentucky, Toni C. Hobbs

Theses and Dissertations--Arts Administration

In rural Appalachia, longstanding patterns of extractive economic development, coupled with limited public investment and uneven institutional support, have contributed to persistent economic stagnation and a diminished sense of pride among residents. These conditions reflect deeper structural challenges, including economies shaped by resource extraction and external control. Addressing these conditions is critical to fostering economic growth, promoting cultural heritage, and enhancing overall well-being in the region. By cultivating resilient communities, leaders can create environments in which both the economy and local pride can thrive, contributing to a more prosperous and unified Appalachian region.

This study investigates the organizational and leadership …

A Comparison Of Time-Dependent Cloudy Astrophysical Code Simulations With Experimental X-Ray Spectra From Kev Laser-Generated Argon Plasmas, N. Rathee, F. P. Keenan, R. J. R. Williams, Gary Ferland, S. J. Rose, S. White, D. Riley

Physics and Astronomy Faculty Publications

We have generated strongly photoionized Ar plasmas in experiments designed to use primarily X-ray l-shell line emission generated from Ag foils irradiated by the VULCAN high-power laser at the UK Central Laser Facility. The principle of the experiment is that use of line emission rather than the usual sub-keV quasi-blackbody source allows keV radiation to play a more dominant role compared to softer X-rays and thus mimic the effect of a blackbody with a higher effective spectral temperature. Our aim is to reproduce in the laboratory the extreme photoionization conditions found in accretion-powered astrophysical sources. In this paper, we compare …

Deep Learning-Based Quantification Of Tall Fescue Abundance In Pastures, Rose E. Binkley, Samuel R. Revolinski, Echo Elizabeth Gotsick, Ray Smith, Zeya Wang, Katsutoshi Mizuta

Plant and Soil Sciences Faculty Publications

Accurate and rapid measurement of tall fescue abundance is essential for efficient forage management and mitigating livestock exposure to potential endophyte-related toxicity. Traditional visual estimation methods are labor-intensive and are subject to change depending on the observer doing the calculations, which limits their scalability and consistency. This study explores the application of deep learning techniques to automate and improve the classification of tall fescue abundance across pasture systems in Kentucky. Ground-truth abundance classes were evaluated using one of the traditional methods with occupancy grid and compared against estimates derived from red-green-blue images. Two convolutional neural network architectures, YouOnlyLookOnce (YOLO) and …

The Association Between Personal Particulate Matter Exposures And Cognitive Function Among Stroke Patients, Kentucky, Usa, Nana Afua Ankomah Dei

Theses and Dissertations--Public Health (M.P.H. & Dr.P.H.)

Stroke, a major cause of long-term disability and cognitive problems in the U.S., significantly affects people’s quality of life. Exposure to particulate matter (PM_2.5) may result in systemic inflammation and oxidative stress, which can worsen the cognitive function of post-thrombectomy stroke patients. This project thus assessed the relationship between PM_2.5 exposure and its effect on the cognitive function of post-thrombectomy stroke patients. Fifteen stroke patients (9 non-Appalachian and 6 Appalachian) undergone thrombectomy were recruited. Personal PM_2.5 exposure was measured using wearable sensors for a week during the study period. Montreal Cognitive Assessment (MoCA) scores and covariates …

Philsongs: A Study Of Campfire Music Performed At Scouting America’S Philmont Scout Ranch (2014 To 2021), Ellyn Rager

Theses and Dissertations--Music

This dissertation focuses on Philmont Scout Ranch, a national Scouting America high adventure base in New Mexico and the largest youth camp in the world, arguing that music at Philmont serves as a cultural force that fosters an intensive communal bond among staff and campers by blending participatory and presentational music-making practices, while producing and reinforcing memories of Philmont through interpretive performances that negotiate the place’s historical narratives. Using surveys, interviews, and Thomas Turino’s framework of participatory and presentational music-making to interpret the author’s 100 hours of field recordings, this study examines aspects of Philmont’s musical habits between 2014 and …

Uncovering The Mechanism Of Reep2-Mediated Emt-Driven Membrane Trafficking In Lung Adenocarcinoma, Kevin Fulp

Theses and Dissertations--Toxicology and Cancer Biology

Membrane trafficking is frequently disrupted during cancer progression, and the underlying mechanisms remain largely unknown. Currently, no effective drugs target dysregulated membrane trafficking for cancer treatment. Recent evidence has demonstrated that epithelial-to-mesenchymal transition (EMT) in lung adenocarcinoma (LUAD) employs a membrane trafficking program to coordinate cancer cell invasion and immunosuppression. To further dissect the pro-tumorigenic membrane trafficking program, we initiated an in vivo CRISPRi screen to assess more than 2,000 membrane trafficking-related genes in a syngeneic mouse LUAD model. We identified REEP2, an endoplasmic reticulum (ER) shaping protein, as a novel regulator of EMT-driven membrane trafficking. High REEP2 expression is …

Psychosocial Strengths Associated With Higher Functioning After Interpersonal Adversity In The United Kingdom And Ireland, Matthew Brooks, Victoria Banyard, Xiafei Wang, Sherry Hamby

Social Work Faculty Publications

Objective: Over the past two decades, positive psychology research has identified correlates of resilience. Although a range of strengths have been explored, there is a need to identify specific strengths that best support individuals to thrive after interpersonal trauma and adversity. This study assessed the contribution of 24 strengths from the Values in Action (VIA) positive psychology survey, alongside five other measures of strengths identified from resilience research, to identify those that show most promise.

Method: In total, 1,440 adults from the United Kingdom and Ireland completed the online VIA survey, and questions on five psychosocial strengths (ecoconnections, …

Cross-Linking Peg Microgels With Mesoporous Organosilica Nanoparticles To Engineer Microporous Annealed Particle Scaffold Properties, Jonathan M. Zuidema, Alessandro Ajo, Marco Carofiglio, Luisa De Cola

Mechanical Engineering Faculty Publications

Microporous annealed particle (MAP) scaffolds composed of cross-linked microgels are emerging as important biomaterials due to their modular design, high porosity, and large surface area, which allow for highly tailored properties, cellular infiltration, nutrient and waste exchange, and improved drug release characteristics. To further expand on these technologies and enhance their modular design, thiolated mesoporous organosilica nanoparticles (ssMSN-SH), which degrade in response to glutathione, were first cross-linked inside of 4-arm poly(ethylene glycol) maleimide microgels. The microgel size, rheological properties, and payload release characteristics were determined. Hierarchical MAP scaffolds were then created by cross-linking 4-arm poly(ethylene glycol) maleimide microgels with ssMSN-SH. …

Coupling Liquid Chromatography To Orbitrap Isotope Ratio Mass Spectrometry: Overcoming Isotope Effects Of Chromatography And Amount-Dependency By Peak Homogenization, Aoife Canavan, Leonhard Prechtl, Habib Al-Ghoul, Nils Kuhlbusch, Andrea M. Erhardt, Martin Elsner

Earth and Environmental Sciences Faculty Publications

Electrospray ionization Orbitrap mass spectrometry (ESI-Orbitrap-MS) has recently proven to be a powerful tool for compound- and position-specific stable isotope analysis, targeting isotopologues of multiple elements (H, C, N, O, S) in polar analytes. However, studies have so far mainly focused on pure analyte solutions via direct infusion. Here, we present the online coupling of liquid chromatography (LC) to ESI-Orbitrap-MS for stable isotope analysis of sulfamethoxazole (SMX), a synthetic antimicrobial, used as a model compound. Our study explored the fidelity of isotope values with two strategies for capturing and broadening chromatographic peaks after LC. When capturing the target analyte in …

Implementing A “Naloxone Hub With Many Spokes” Model In Kentucky: Partner Agency Perspectives On Implementation Strategies, Hannah K. Knudsen, Michael Goetz, Shaquita Andrews-Higgins, Sandra Back-Haddix, Olivia A. Davis, Patricia R. Freeman, Douglas R. Oyler, Sharon L. Walsh

Behavioral Science Faculty Publications

Background: Overdose education and naloxone distribution (OEND) is a vitally important evidence-based practice for addressing the ongoing opioid epidemic. During the HEALing Communities Study in Kentucky, OEND was dramatically scaled up in eight counties using a “hub with many spokes” model and multifaceted implementation strategies. This aim of this manuscript is to describe qualitative perspectives of partner organizations regarding the utility of the implementation strategies used to expand OEND.   Method: Twenty small-group and 24 individual qualitative interviews were conducted with staff from 44 agencies that implemented OEND through partnerships with the study team. Interviews were conducted 6–8 months after the …

Knowledge Based Automated Planning For Non-Coplanar Vmat Stereotactic Radiosurgery In Ocular Malignancies, Chase Cochran, Shane Mccarthy, William St. Clair, Damodar Pokhrel

Radiation Medicine Faculty Publications

Background and Purpose: Stereotactic radiosurgery/radiotherapy (SRS/SRT) has emerged as a less invasive alternative to enucleation in the management of ocular malignancies. SRS/SRT planning is time-consuming, complex, and the plan quality depends on the experience of the treatment planner. We demonstrate the use of RapidPlan modeling in conjunction with HyperArc for the treatment of ocular diseases to improve planning efficiency, consistency, and quality.

Materials and Methods: A HyperArc-based RapidPlan (HARP) model was iteratively trained on 80 patient datasets that simulated ocular malignancies. Twenty additional patient datasets were reserved for model testing and comparison with manual plans. Each testing dataset was both …

Designing Theranostic Radiopharmaceutical Trials For Uterine Cervix Cancer, Denise Fabian, Molly E. Buffington, Brianna S. Cagle, Steve M. Keefe, Michael K. Schultz, Charles A. Kunos

Radiation Medicine Faculty Publications

Designing and interpreting early phase trials of theranostic radiopharmaceuticals remains challenging because it is difficult to isolate effective levels of activity in enriched patient populations that would be worth following up in later-phase development. This study explores the known challenges and emerging opportunities for clinical research on patients with uterine cervical cancer. We identified eight randomized combination trials for advanced-stage uterine cervix cancer that were activated between 2011 and 2022 and tabulated their results to determine whether combinations were better than individual constituents and which suitable study population is best situated for the study of a new theranostic agent. In …

Artificial Intelligence Methods For Circadian Rhythm Recovery And Disease Identification From High-Dimensional Omics Data, Aram Ansary Ogholbake

Theses and Dissertations--Computer Science

High-throughput transcriptomic and proteomic technologies have enabled opportunities for studying biological processes and disease mechanisms. However, extracting meaningful biological information from these high-dimensional datasets remains challenging due to limited sample sizes, biological heterogeneity, measurement noise, and the absence of biological annotations. In particular, many molecular datasets lack temporal information required for circadian analysis, making the study of circadian rhythms difficult. Moreover, disease diagnosis and biomarker discovery from transcriptomic data often rely on complex machine learning models whose predictions are difficult to interpret and may not generalize well across independent datasets and experimental platforms. These limitations motivate the development of artificial …

From Anxiety To Stewardship: An Autoethnographic Study Of Therapist Development, Christie Ellis

Theses and Dissertations--Family Sciences

Routine outcome monitoring (ROM) is recognized as an evidence-informed practice for supporting psychotherapy outcomes, yet limited research has examined how therapists-in-training experience integrating ROM into their clinical development. This autoethnographic study investigated the role of ROM in shaping therapist identity development within a university-based marriage and family therapy training clinic. Qualitative data included 34 reflective journal entries analyzed using reflexive thematic analysis, and quantitative data included multiple client outcome trajectories across several clinical measures compared descriptively with prototypical change trajectories derived from MFT-PRN datasets. Qualitative findings reflected a developmental progression from initial anxiety and performance concerns toward increased confidence, attunement, …

Goal-Driven Shared Control In Eeg-Based Brain Machine Interface For Freewill Reaching And Grasping With Movement Intention Detection And Goal Position Decoding, Bhoj Raj Thapa

Theses and Dissertations--Electrical and Computer Engineering

Upper limb motor impairments can severely limit a person’s ability to perform everyday reaching and grasping tasks. Electroencephalogram (EEG)-based brain machine interfaces (BMIs) offer a non-invasive approach for translating neural activity into control signals for assistive devices such as robotic arms. However, traditional EEG-based BMI studies have generally focused on externally cued paradigms, where both movement timing and target selection are specified by the experimenter rather than freely chosen by the user. In addition, shared control offers a practical framework for assistive BMI operation by dividing responsibility between the user and the intelligent robotic system. However, in many EEG-based shared …

Effect Of Environmental Conditions On German Cockroach (Blattella Germanica) Behavior And Survival, Allison Lopina

Theses and Dissertations--Entomology

German cockroaches (Blattella germanica L.) remain one of the most challenging indoor pests to manage, due to resistance to many commonly used insecticides, and necessary contact/interaction with common management tactics. As such, it is critical to fully understand their aggregation, movement, and longevity, such that treatments can be optimally placed to result in maximal efficacy. The first part of this study explored the effects of multiple factors (harborage width, harborage materials, heat, resource-harborage distance) on initial site selection, and how environmental modifications and infestation density impact harborage site switching. The second half of the study aimed to explore the …

Accelerator Based Fusion Reactor With Magnetic Mirror, Keh-Fei Liu

Physics and Astronomy Faculty Publications

We consider an implementation of the novel accelerator-based fusion reactor scheme using a setup in which ion and electron beams are injected into the end openings of an axisymmetric magnetic mirror. While the magnetic mirror ensures transverse confinement of the plasma, the injected beams contribute to axial confinement, thereby extending the overall plasma lifetime. The ion beam energy is initially set above the resonance region of the fusion reactions, allowing fusion to occur both via resonance and thermal mechanisms as the beam slows down to the plasma temperature. Beam energy loss (stopping power) contributes to plasma heating, offsetting radiative losses …

Dynamical Phases Of Higher Dimensional Floquet Cfts, Diptarka Das, Sumit R. Das, Arnab Kundu, Krishnendu Sengupta

Physics and Astronomy Faculty Publications

This paper investigates the dynamical phases of Floquet Conformal Field Theories (CFTs) in space-time dimensions greater than two. Building upon our previous work which introduced quaternionic representations for studying Floquet dynamics in higher-dimensional CFTs, we now explore more general square pulse drive protocols that go beyond a single SU(1,1) subgroup. We demonstrate that, for multi-step drive protocols, the system exhibits distinct dynamical phases characterized by the nature of the eigenvalues of the quaternionic matrix representing time evolution in a single cycle, leading to different stroboscopic responses. Our analysis establishes a fundamental geometric interpretation where these dynamical phases directly correspond to …

Emission-Line Diagnostics At Z ≳ 2: A Probe Of The Ionizing Spectrum And Α-Enhancement Beyond Cosmic Noon, Leonardo Clarke, Natalie Lam, Alice E. Shapley, Michael W. Topping, Gabriel B. Brammer, Ryan L. Sanders, Naveen Reddy, Shreya Karthikeyan

Physics and Astronomy Faculty Publications

We analyze several key rest-optical emission-line ratios in a sample of 828 galaxies as well as composite spectra from JADES DR3 in the range 1.4 <  z <  7. These emission-line ratios include: [O iii]λ5008/Hβ, [N ii]λ6585/Hα, [S ii]λλ6718, 6733/Hα, [O i]λ6302/Hα, O32, R23, Ne3O2, and RO2Ne3. We find evidence for a harder ionizing spectrum at z ∼ 3.5 compared to z ∼ 2 at fixed gas-phase metallicity, resulting in a pronounced shift in the star-forming galaxy locus on the [N ii]/Hα Baldwin-Phillips-Terlevich (BPT) diagram and the O32 versus R23 diagram. At …