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Articles 1 - 30 of 3132

Full-Text Articles in Physical Sciences and Mathematics

The Interwoven Dynamics Of Climate, Fire, Resilience And Orangutan Survival In Central Kalimantan’S Peat Swamp Forest, Putu Pujiantari Jul 2026

The Interwoven Dynamics Of Climate, Fire, Resilience And Orangutan Survival In Central Kalimantan’S Peat Swamp Forest, Putu Pujiantari

Graduate Theses and Dissertations

Tropical peat swamp forests are globally significant carbon reservoirs and biodiversity strongholds, yet they face escalating threats from climate change, fire, and anthropogenic disturbances. This dissertation investigates the interwoven dynamics of climate, fire, forest resilience, and orangutan survival in Central Kalimantan, Indonesia, a region which was transformed by the failed Mega Rice Project and recurrent catastrophic wildfires for decades. Using a multi-scale approach that integrates remote sensing time-series analysis (2001–2024),nlandscape-scale disturbance mapping (2005–2025), and fine-scale movement ecology, this research tests three core hypotheses: (1) moisture availability is the dominant climatic driver of wildfire activity, operating through non-linear thresholds; (2) post-fire …

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Establishing Ferromagnetism In Van Der Waals Antiferromagnets Mps3, Dinesh Upreti Jul 2026

Establishing Ferromagnetism In Van Der Waals Antiferromagnets Mps3, Dinesh Upreti

Graduate Theses and Dissertations

Recent discoveries of magnetism in low dimensions not only have gained fundamental scientific interest but also holds significant potential in numerous technological applications, such as spintronics. This has led to a wide range of efforts in the synthesis of new layered materials or tuning their existing magnetic properties, which has been instrumental in understanding the novel physical concept and development of new technological frontiers. Transition metal thiophosphate, MPS3, is a class of layered antiferromagnet family. The rich magnetic/crystal structure with delicate choice of transition metal (M) together with intriguing optical, electronic, and ferroelectric properties have placed them as a model …

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Chaotropic And Kosmotropic Effects Of Brines On Protein Structure: Habitability Across The Solar System, Shelby Dawn Osborne Jul 2026

Chaotropic And Kosmotropic Effects Of Brines On Protein Structure: Habitability Across The Solar System, Shelby Dawn Osborne

Graduate Theses and Dissertations

Salts exhibit unique and specific effects on biomolecular structure depending on the physical nature of the salt (ion density, formation of hydration shells, direct binding to protein). This thesis implements biochemical, thermodynamic, and computational methods to investigate how the nature of the salt effects protein structure, which aids in defining the habitability of various brine solutions. By using simple proteins and solar system relevant salts, we inspect the physical reactions of proteins to these saltwater environments to understand which salts stabilize or destabilize protein structure. Several methods of experimentation are utilized to provide an understanding of the interaction relevant to …

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Automated Machine Learning And Satellite Image Data Fusion For Monitoring Water Quality In Mosaicked Landscapes, Sahar Rezaei Jul 2026

Automated Machine Learning And Satellite Image Data Fusion For Monitoring Water Quality In Mosaicked Landscapes, Sahar Rezaei

Graduate Theses and Dissertations

Despite the ecological, economic, and social importance of inland water bodies, they are increasingly impacted by human and natural drivers. Harmful algal blooms (HABs) and total suspended solids (TSS) are key indicators of water quality, and elevated concentrations pose significant ecological and public health risks. The spatiotemporal dynamics of these variables remain insufficiently understood in major river systems, including the Upper Mississippi River (UMR) and the Illinois River Basin (IRB). While in situ measurements provide accurate observations, they are costly and offer limited spatial and temporal coverage, restricting basin-scale monitoring. Remote sensing offers a powerful alternative; however, single-sensor approaches are …

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Advancing Social Media Analytics And Personalized Generation Via Transfer Learning, Discourse-Aware Modeling, And Collaborative Modeling, Gibson Nkhata Jul 2026

Advancing Social Media Analytics And Personalized Generation Via Transfer Learning, Discourse-Aware Modeling, And Collaborative Modeling, Gibson Nkhata

Graduate Theses and Dissertations

Social media platforms have become central to information exchange, shaping public opinion across social, political, and economic domains. However, the massive volume of user-generated content, combined with its informal, nuanced, and often noisy nature, presents significant challenges for automated analysis and generation. Tasks such as stance detection, rumor verification, and personalized content generation are further complicated by sarcasm, evolving discourse structures, and diverse user preferences. Addressing these challenges requires models that can effectively leverage linguistic nuance, conversational dynamics, and collaborative user signals. Transfer learning has emerged as a powerful paradigm for improving performance in low-resource and complex language understanding tasks. …

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Towards Audio-Driven Photorealistic Avatars For Teleconsultation: A Development And Evaluation Framework Under Constrained Bandwidth Environments, Fnu Himanshu Jul 2026

Towards Audio-Driven Photorealistic Avatars For Teleconsultation: A Development And Evaluation Framework Under Constrained Bandwidth Environments, Fnu Himanshu

Graduate Theses and Dissertations

Telehealth can improve access to healthcare services, especially for patients in rural and underserved areas. Many telehealth services use video communication to provide real-time interaction and a visible connection between patients and healthcare providers. However, video communication requires continuous transmission of audio and video data. When network conditions are limited or unreliable, audio and video interruptions can reduce communication quality. This thesis explores an audio-driven photorealistic avatar as a possible visual communication layer for teleconsultation without requiring continuous webcam video transmission. It develops two connected frameworks: the Audio-Driven Photorealistic Avatar Communication Framework and the Evaluation Framework. The Audio-Driven Photorealistic Avatar …

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Investigation Of Early To Late Cretaceous North American Ecosystems And Paleoclimate Using Geochemical Proxies, Clayton William Forster Jul 2026

Investigation Of Early To Late Cretaceous North American Ecosystems And Paleoclimate Using Geochemical Proxies, Clayton William Forster

Graduate Theses and Dissertations

The relationships between the environment and an organism can be traced through stable isotope and trace element geochemistry. This thesis explores the stable oxygen and carbon isotopic composition of fossil vertebrate assemblages in pursuit of revealing the relationships between dinosaurs and their archosaur relatives with the environment in which they lived during the Cretaceous. The Cretaceous Period of North America experienced some of the hottest intervals in the Phanerozoic Eon and the continental vertebrate taxa that existed during this time recorded these periods within the stable isotopic composition of their skeletal bioapatite. Oxygen isotopes in the bioapatite of vertebrates reflect …

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Item Response Theory Evaluation Of Mental Health Sentiment Scales, Muhammad Amzad Hossain Jul 2026

Item Response Theory Evaluation Of Mental Health Sentiment Scales, Muhammad Amzad Hossain

Graduate Theses and Dissertations

Mental health is an essential part of overall well-being. Accurate measurement of constructs such as loneliness, anxiety, depression, and life satisfaction is extremely important in research and practice. Traditional approaches based on Classical Test Theory (CTT) are limited. They rely on total test scores and assume constant measurement error across individuals. They may not reflect true variability in measurement precision (Zein & Akhtar, 2025; Marvianto, 2023). In contrast, Item Response Theory (IRT) provides an advanced approach by examining item-level performance. It models the relationship between latent traits and responses (Zein & Akhtar, 2025 ). To address these limitations, this study …

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Univariate And Bivariate Binary Spatial Regression Models With Application To Plant Abundance Data, Amir Hamza Akash Jul 2026

Univariate And Bivariate Binary Spatial Regression Models With Application To Plant Abundance Data, Amir Hamza Akash

Graduate Theses and Dissertations

Analyzing species distributions is of prime interest in ecological research. Prevalence of a species usually depends on several environmental and topographic features not all of which can be quantified or measured. Spatial random effects play an important role as a surrogate for missing features that can explain similarity in species prevalence patterns between neighboring locations. In this thesis, we focus on a dataset on abundance of plants in the southern part of South Africa. First, we build a hierarchical Bayesian model for binary regression, using the probit link, on presence/ absence of a species based on available covariates. Since the …

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Cosmic Chirps: Studies In The Evolution And Detection Of Gravitational Waves From Compact Binary Systems, Calla Irene Bassett Bigg Jul 2026

Cosmic Chirps: Studies In The Evolution And Detection Of Gravitational Waves From Compact Binary Systems, Calla Irene Bassett Bigg

Graduate Theses and Dissertations

This dissertation will go over three projects that have to do with gravitational wave mechanics and history. The first project is about investigating computationally cheaper approximation methods for modeling EMRI (extreme mass ratio inspiral) orbits using interpolation. Two codes are interpolated together for full coverage of the parameter space. This interpolation has yet to be tested for accuracy but the preliminary outlook is positive. This may well be a useful tool for studying EMRIs. The second project is investigating the origins of the term “chirp mass”, where chirp mass is a combination of the two masses in a binary that …

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Beyond Semantic Matching: Integrating Graph Structures, Boolean Logic, And Interactive Aggregation In Modern Retrieval, Quan Mai Jul 2026

Beyond Semantic Matching: Integrating Graph Structures, Boolean Logic, And Interactive Aggregation In Modern Retrieval, Quan Mai

Graduate Theses and Dissertations

Modern Natural Language Processing (NLP) and Information Retrieval (IR) systems have achieved remarkable success in semantic understanding; however, they continue to struggle with complex logical reasoning, structural interactions, and dynamic aggregation. This dissertation presents a comprehensive framework to enhance the structural, logical, and interactive capabilities of language models and retrieval systems across four progressive studies. First, we address the challenge of modeling dynamic conversational logic in online debates. We introduce a Sequence Graph Network (SGN) that captures the temporal and interactive exchange of ideas—such as counterarguments and reinforcements—by updating node features sequentially through a novel Sequence Graph Attention (SGA) layer. …

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Soil Moisture Regime Effects On Greenhouse Gas Emissions In A Native Tallgrass Prairie In The Ozark Highlands, Thomas William Dockery Jul 2026

Soil Moisture Regime Effects On Greenhouse Gas Emissions In A Native Tallgrass Prairie In The Ozark Highlands, Thomas William Dockery

Graduate Theses and Dissertations

The Ozark Highlands is an ecoregion in the mid-southern portion of the United States that is characterized by a mosaic of tallgrass prairies, oak (Quercus spp.) savannas, and oak-hickory (Carya spp.) forests, which represents a unique biophysical transition zone between the relatively dry grasslands of the west and the humid forests of the southeast. Quantifying greenhouse gas (GHG) emissions, namely carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O), from natural, undisturbed ecosystems is critical to understanding atmospheric warming and climate-change implications. The objective of this study was to simultaneously evaluate CO2, CH4, and N2O emissions in an aquic and …

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Potassium Fertilization Timing And Critical Stalk Potassium Concentration As Tools To Improve Corn Production, Gabriela Andrade Leite Mengez Jul 2026

Potassium Fertilization Timing And Critical Stalk Potassium Concentration As Tools To Improve Corn Production, Gabriela Andrade Leite Mengez

Graduate Theses and Dissertations

Potassium (K) is a common yield-limiting nutrient in Mid-Southern U.S. corn (Zea mays L.) production, emphasizing the importance of effective diagnostic tools to support fertilizer decision-making. This study integrated two approaches to improve K management in irrigated corn systems: (i) evaluating K fertilization timing to identify in-season opportunities for correcting K deficiency, and (ii) developing a corn stalk-based diagnostic test to assess end-of-season K and nitrate-nitrogen (NO₃-N) status and fertilizer adequacy. Seven (2024-2025) and eight (2023-2024) field trials were conducted across Arkansas for the K application timing and stalk testing studies, respectively. For the K timing study, fertilizer-K (112 kg …

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Physics-Informed Machine Learning For Predictive Digital Twins In Greenhouses, Hoang Kim Tran Jul 2026

Physics-Informed Machine Learning For Predictive Digital Twins In Greenhouses, Hoang Kim Tran

Graduate Theses and Dissertations

Greenhouses are widely used to create controlled environments for crop production, where indoor climate variables such as air temperature, relative humidity, CO2 concentration, radiation, and soil or substrate conditions directly affect plant growth, yield, energy consumption, and resource use. However, greenhouse climates are highly dynamic because they are influenced by complex interactions among outdoor weather, greenhouse structure, crop transpiration, heating systems, ventilation, screens, fans, irrigation, and other actuators. Building digital twins for greenhouses provides a powerful way to represent, monitor, and predict these climate dynamics. A predictive digital twin can simulate future indoor climate states based on current greenhouse conditions, …

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Benchmarking Current Progress In 3d Content Generation, Vuong Ho Jul 2026

Benchmarking Current Progress In 3d Content Generation, Vuong Ho

Graduate Theses and Dissertations

In recent years, 3D generation has rapidly advanced with the development of powerful generative AI models capable of producing high-quality 3D content from various modalities, including text, images, and multi-view inputs. These advancements have significantly accelerated progress in applications such as gaming, virtual reality, robotics, and digital content creation. Despite this progress, there is still a lack of standardized and fair benchmarking protocols for evaluating 3D generation methods. Existing approaches are often assessed under inconsistent experimental settings, using different datasets, evaluation metrics, and processing pipelines. Such inconsistencies make reliable and objective comparisons difficult, limiting our understanding of the strengths and …

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Localizing And Repairing Backdoor-Sensitive Layers In Pre-Trained Language Models For Secure Fine-Tuning, Sunanda Das Jul 2026

Localizing And Repairing Backdoor-Sensitive Layers In Pre-Trained Language Models For Secure Fine-Tuning, Sunanda Das

Graduate Theses and Dissertations

Task-agnostic backdoor attacks can contaminate pre-trained language models (PLMs) in a way that survives downstream adaptation, even under full fine-tuning, making it difficult for practitioners to trust third-party checkpoints. Existing defenses often rely on privileged assumptions (e.g., access to poisoned data or trigger/target knowledge), thereby limiting their applicability in realistic settings. We present DiSec (Disentanglement of potentially adversarial weights for Secure fine-tuning), a robust and label-efficient purification framework that uses only clean auxiliary text and does not rely on downstream supervision or attack signatures. DiSec elicits model-internal signals from this clean data to separate suspicious parameter components that are inconsistent …

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Iterative Generation Of Feature-Based Cad Models Using An Llm With Domain Specific Constraints, Ammon I. Hepworth Jul 2026

Iterative Generation Of Feature-Based Cad Models Using An Llm With Domain Specific Constraints, Ammon I. Hepworth

Graduate Theses and Dissertations

This paper presents a method to generate feature-based parametric mechanical CAD models from text input. The method uses domain-specific constraints (DSCs) to guide a large language model (LLM) in the generation of scripts to build models from the CAD API. It also presents a framework for an iterative text-based system that produces parametric CAD models. The method was implemented by developing DSCs for FreeCAD and Open AI GPT-5.2 and incorporated into a web-based software application which generates models that can be visualized with an interactive viewer after each iteration. Tests were run comparing various models with and without this method. …

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Statistical Machine Learning For Calibrating Climate Model Wind Fields., Augustine Ouru Jul 2026

Statistical Machine Learning For Calibrating Climate Model Wind Fields., Augustine Ouru

Graduate Theses and Dissertations

This thesis investigates statistical calibration methods for wind data from Global Climate Models (GCMs), with emphasis on wind speed and wind direction. The analysis uses 30 years of daily observed and GCM wind records from 9 spatial locations in the South East USA. Wind is represented in polar coordinates, but also often modeled in Cartesian coordinates. Four calibration models are compared: a marginal wind speed model, an independent Cartesian model. The calibration models are based on semi-parametric quantile regression, a flexible conditional density estimator fitted using neural networks. The neural network objective functions are optimized using maximum likelihood estimation (MLE) …

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Instructions To Authors, Academy Editors Jun 2026

Instructions To Authors, Academy Editors

Journal of the Arkansas Academy of Science

No abstract provided.

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Journal Acknowledgements And Editorial Board, Academy Editors Jun 2026

Journal Acknowledgements And Editorial Board, Academy Editors

Journal of the Arkansas Academy of Science

No abstract provided.

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Keynote Address And Meeting Program, Academy Editors Jun 2026

Keynote Address And Meeting Program, Academy Editors

Journal of the Arkansas Academy of Science

No abstract provided.

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Business Meeting Report (Secretary's And Treasurer's Report), Academy Editors Jun 2026

Business Meeting Report (Secretary's And Treasurer's Report), Academy Editors

Journal of the Arkansas Academy of Science

No abstract provided.

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Artificial Food Colors Are Not Needed To Attract Ruby-Throated Hummingbirds (Archilochus Colubris) To Feeders, A. Siddiqui, R. Kannan Jun 2026

Artificial Food Colors Are Not Needed To Attract Ruby-Throated Hummingbirds (Archilochus Colubris) To Feeders, A. Siddiqui, R. Kannan

Journal of the Arkansas Academy of Science

No abstract provided.

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Noteworthy Natural History Notes From The Neotropics, R. Kannan Jun 2026

Noteworthy Natural History Notes From The Neotropics, R. Kannan

Journal of the Arkansas Academy of Science

I report some rarely observed, infrequently reported, or hitherto unrecorded ecological interactions from the neotropics. These anecdotal observations were made opportunistically during nature tours or tropical biology classes in Belize, Panama, Costa Rica, and Trinidad & Tobago, between 2014 and 2024.

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Sperm Morphology In The Eastern Narrow-Mouthed Frog, Gastrophryne Carolinensis (Anura: Microhylidae), S. E. Trauth Jun 2026

Sperm Morphology In The Eastern Narrow-Mouthed Frog, Gastrophryne Carolinensis (Anura: Microhylidae), S. E. Trauth

Journal of the Arkansas Academy of Science

Studies by Scheltinga et al. (2002) and Scheltinga and Jamieson (2003) provide the most comprehensive analysis and only review of sperm morphology in Narrow-Mouthed Frogs (family Microhylidae). Of the 490+ species known to occur in this anuran family (Vitt and Caldwell 2014), only 3 are distributed in the United States (Powell et al. 2016), and 2 of these occur in Arkansas (Trauth et al. 2004). Surprisingly, sperm studies on only 12 microhylid species have been conducted (Scheltinga and Jamieson 2003), and no sperm studies are available on any North American species.

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A Review Of Herpetofaunal Distributions In Arkansas With Special Emphasis On Contributions From Citizen Science: Part Ii – Turtles, Lizards, And Alligators, L. Hobbs, E. Kelley, J. Jackson, J.D. Willson, K. G. Roberts, R. Kannan Jun 2026

A Review Of Herpetofaunal Distributions In Arkansas With Special Emphasis On Contributions From Citizen Science: Part Ii – Turtles, Lizards, And Alligators, L. Hobbs, E. Kelley, J. Jackson, J.D. Willson, K. G. Roberts, R. Kannan

Journal of the Arkansas Academy of Science

We update and present a comprehensive review of the distributions of the species of lizards (14), alligators (1), and turtles (16) in Arkansas. We compare historical and current distributions with citizen science data uploaded and verified in iNaturalist, a leading online citizen science biodiversity monitoring database. The Arkansas Herpetological Atlas, an online resource maintaining species occurrence records, is also used and compared. We highlight the role played by iNaturalist in enhancing our knowledge of the distributions of these species in Arkansas. As of 13 February 2025, verified and vetted Research Grade (RG) iNaturalist observations from Arkansas include 7,462 observations of …

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History And Distribution Of The Dark Ibises (Glossy Ibis Plegadis Falcinellus And White-Faced Ibis P. Chihi) In Arkansas, R. Tumlison, P. D. Rodriguez Jun 2026

History And Distribution Of The Dark Ibises (Glossy Ibis Plegadis Falcinellus And White-Faced Ibis P. Chihi) In Arkansas, R. Tumlison, P. D. Rodriguez

Journal of the Arkansas Academy of Science

The Glossy Ibis (Plegadis falcinellus) and White-faced Ibis (P. chihi) sometimes are reported simply as Dark Ibises due to difficulty in identifying them when mature characters are not clearly visible. We evaluated reports verified on citizen science websites to examine the origins and distributions of these migratory species in Arkansas. The Glossy Ibis was first documented in Arkansas in 1956, has been reported in 21 of our 75 counties, and is found more commonly in eastern Arkansas. The White-faced Ibis was first reported in Arkansas in 1971, has been reported in 41 of our 75 counties, …

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History And Distribution Of Great-Tailed Grackles (Quiscalus Mexicanus) In Arkansas, R. Tumlison, V. Andersen Jun 2026

History And Distribution Of Great-Tailed Grackles (Quiscalus Mexicanus) In Arkansas, R. Tumlison, V. Andersen

Journal of the Arkansas Academy of Science

Great-tailed Grackles (Quiscalus mexicanus) were reported first in southwestern Arkansas in 1969, were nesting there in 1977, and established a resident population by 1980. Nesting was reported in far northwestern Arkansas in 1986. Presently, the species is known from 44 of Arkansas’s 75 counties, those mostly in the western and central counties. Most individuals appear to be migratory, with most reports occurring in April and May. However, breeding and now resident populations have been reported in the southwestern, northwestern, and central counties, particularly in urban areas. Birds are very commonly reported to forage at fast-food establishments and truck …

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Multiple Nuclear Configurations And Microtubular Arrangements In Spermatozoa Of The Western Siren, Siren Nettingi (Caudata: Sirenidae), S. E. Trauth Jun 2026

Multiple Nuclear Configurations And Microtubular Arrangements In Spermatozoa Of The Western Siren, Siren Nettingi (Caudata: Sirenidae), S. E. Trauth

Journal of the Arkansas Academy of Science

I examined the ultrastructure of spermatozoa of the Western Siren, Siren nettingi, using transmission electron microscopy. My primary objective in this study was to elucidate, for the first time, the unique morphological complexity of biflagellated sperm in this species. This study also represents my fifth addition in a series of investigations that highlight the novel nature of all aspects of spermatogenesis in this salamander I show the basic sperm transverse and sagittal design which includes a nucleus, 2 axial fibers supporting 2 undulating membranes which have 2 axonemes residing at their terminal ends, several circular mitochondria, and several electron-dense masses. …

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Binucleation And Seasonal Cycle Of Sertoli Cells In The Western Lesser Siren, Siren Nettingi (Caudata: Sirenidae), S. E. Trauth Jun 2026

Binucleation And Seasonal Cycle Of Sertoli Cells In The Western Lesser Siren, Siren Nettingi (Caudata: Sirenidae), S. E. Trauth

Journal of the Arkansas Academy of Science

I examined binucleation and the seasonal cycle of Sertoli cells in the Western Siren (Siren nettingi) using light microscopy and transmission electron microscopy. My primary objective in this study was to report, for the first time, the presence of double nuclei in Sertoli cells in a salamander. This study also represents the sixth contribution in a series of investigations that highlight the novel nature of all aspects of spermatogenesis in this unique salamander. My findings add to a growing list of extraordinary morphological and reproductive features that distinguish this salamander from all other vertebrates.

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