Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network™

Open Access. Powered by Scholars. Published by Universities.®

Old Dominion University

Discipline
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 1111 - 1140 of 14981

Full-Text Articles in Entire DC Network

A Trust-By-Learning Framework For Secure 6g Wireless Networks Under Native Generative Ai Attacks, Md Shirajum Munir, Sravanthi Proddatoori, Manjushree Muralidhara, Trinidad Mario Dena, Walid Saad, Zhu Han, Sachin Shetty Jan 2025

A Trust-By-Learning Framework For Secure 6g Wireless Networks Under Native Generative Ai Attacks, Md Shirajum Munir, Sravanthi Proddatoori, Manjushree Muralidhara, Trinidad Mario Dena, Walid Saad, Zhu Han, Sachin Shetty

Center for Secure and Intelligent Critical Systems (CSICS) Publications

Sixth-generation (6G) wireless networks will become vulnerable due to native generative AI (GenAI)-driven intelligent poisoning attacks in both the radio unit and the core network. In particular, network parameters and metrics in cross-layer design pose fundamentally uncertain conditions and can be compromised through the native GenAI mechanism, which leverages data augmentation and reconstruction capabilities. This work investigates the capabilities of native GenAI to create novel poisoning attacks in wireless networks, while investigating their impact through uncertainty-informed root analysis. Then, detected attacks are mitigated by developing a trustworthy service aggregation in the wireless network. First, a joint decision problem is formulated …

Go to article

Examining Non-Traditional Online Learners' Ownership Of Learning In The Context Of Chatgpt-Facilitated Design, Mohan Yang, Tian Luo, Kristin Herman, Belle Li, Shanan Chappell Moots, Noah Glaser, Shiyan Jiang Jan 2025

Examining Non-Traditional Online Learners' Ownership Of Learning In The Context Of Chatgpt-Facilitated Design, Mohan Yang, Tian Luo, Kristin Herman, Belle Li, Shanan Chappell Moots, Noah Glaser, Shiyan Jiang

STEMPS Faculty Publications

Generative artificial intelligence (GenAI) offers potential solutions to educational challenges by personalizing learning experiences for diverse learners. However, it also introduces complexities around issues of ownership of learning. As an indicator of empowered learning, ownership is a multifaceted but underexplored concept. In this study, the authors adopted a mixed-methods multiple-case study design to explore non-traditional online students’ perceived ownership of learning when using ChatGPT for instructional design. The authors adopted the psychology ownership construct consisting of self-efficacy, accountability, belongingness, and self-identity as the theoretical framework. Findings revealed students’ prior AI experiences and educational levels played a significant role in their …

Go to article

Socially Shared Regulation Of Learning And Artificial Intelligence: Opportunities To Support Socially Shared Regulation, Jinhee Kim, Rita Detrick, Seongryeong Yu, Yukyeong Song, Linda Bol, Na Li Jan 2025

Socially Shared Regulation Of Learning And Artificial Intelligence: Opportunities To Support Socially Shared Regulation, Jinhee Kim, Rita Detrick, Seongryeong Yu, Yukyeong Song, Linda Bol, Na Li

STEMPS Faculty Publications

Supporting learners in achieving high-level socially shared regulation of learning (SSRL) in the online collaborative learning (OCL) context presents challenges that the utilization of artificial intelligence (AI) technologies may help solve. However, the effective uses of AI to support multifaceted areas (cognition, metacognition, and motivation) and phases (forethought, performance, and reflection) of SSRL remain elusive. Furthermore, research on developing an educational AI and what pedagogical attributes and elements are required for AI to support students' SSRL effectively is limited. This study, therefore, aims to investigate students' perceptions of AI applications in enhancing SSRL and to explore the essential pedagogical elements …

Go to article

Leveraging Custom Gpts For Formative Assessment And Feedback, Nari Kim, Jason Vickers, Shaimaa Alyehaibi, Chikezie Ozuzu, Xinyue Ren, Suhasini Kotcherlakota Jan 2025

Leveraging Custom Gpts For Formative Assessment And Feedback, Nari Kim, Jason Vickers, Shaimaa Alyehaibi, Chikezie Ozuzu, Xinyue Ren, Suhasini Kotcherlakota

STEMPS Faculty Publications

As artificial intelligence (AI) advances, the use of custom generative pre-trained transformers (Custom GPTs) in formative assessments opens new opportunities for improving student learning and engagement. Custom GPTs increase cognitive and emotional engagement by providing timely, context-sensitive, and tailored responses based on unique learner profiles. This paper aims to investigate how custom GPT-driven formative feedback can enhance individualized learning experiences and improve student performance. This paper will discuss the promise of this AI tool, the challenges associated with its application, and recommendations for educators and academics looking to use these technologies for formative assessments.

Go to article

The Integration Of Artificial Intelligence And Ontologies: Transformations In Knowledge Representation And Application, Grazia Serratore, Julaine Clunis Jan 2025

The Integration Of Artificial Intelligence And Ontologies: Transformations In Knowledge Representation And Application, Grazia Serratore, Julaine Clunis

STEMPS Faculty Publications

Artificial Intelligence (AI) is reshaping the landscape of knowledge representation. There is an increasingly strong bidirectional relationship, between AI techniques and ontologies. AI techniques revolutionized traditional, manual ontology development and contribute to automated ontology construction, while ontologies enhance the performance of AI systems and their semantic accuracy. Through a comprehensive review of current literature, this paper aims to examine: i) how Machine Learning (ML) techniques contribute to the automated construction, refinement, and validation of ontologies; ii) the most widely used and effective ML approaches for ontology construction; iii) how domain-specific requirements influence the selection and adaptation of AI techniques for …

Go to article

Exploring The Impact Of Generative Ai Chatgpt On Critical Thinking In Higher Education: Passive Ai-Directed Use Or Human-Ai Supported Collaboration?, Nesma Ragab Nasr, Chih-Hsiung Tu, Jennifer Werner, Tonia Bauer, Cherng-Jyh Yen, Laura Sujo-Montes Jan 2025

Exploring The Impact Of Generative Ai Chatgpt On Critical Thinking In Higher Education: Passive Ai-Directed Use Or Human-Ai Supported Collaboration?, Nesma Ragab Nasr, Chih-Hsiung Tu, Jennifer Werner, Tonia Bauer, Cherng-Jyh Yen, Laura Sujo-Montes

STEMPS Faculty Publications

Generative AI is weaving into the fabric of many human aspects through its transformative power to mimic human-generated content. It is not a mere technology; it functions as a generative virtual assistant, raising concerns about its impact on cognition and critical thinking. This mixed-methods study investigates how GenAI ChatGPT affects critical thinking across cognitive presence (CP) phases. Forty students from a four-year university in the southwestern United States completed a survey; six provided their ChatGPT scripts, and two engaged in semi-structured interviews. Students’ self-reported survey responses suggested that GenAI ChatGPT improved triggering events (M = 3.60), exploration (M = 3.70), …

Go to article

Designing Ai-Powered Learning: Adult Learners' Expectations For Curriculum And Human-Ai Interaction, Jinhee Kim, Seongryeong Yu, Rita Detrick, Xi Lin, Na Li Jan 2025

Designing Ai-Powered Learning: Adult Learners' Expectations For Curriculum And Human-Ai Interaction, Jinhee Kim, Seongryeong Yu, Rita Detrick, Xi Lin, Na Li

STEMPS Faculty Publications

Despite the potential benefits offered by GenAI technologies to provide innovative solutions to address distinct challenges faced by working adult learners (ALs) in higher education and beyond, there is limited understanding of how best to structure AI-powered learning for this population while ensuring their distinct needs and perspectives are considered. Hence, this study aimed to determine what curriculum and student-AI interaction would be required by situating ALs’ views. Through analyzing 48 e-portfolios and in-depth interviews with 20 ALs from diverse educational and professional backgrounds, the study found that ALs perceived content mastery and developing a lifelong habit of learning as …

Go to article

Artificial Intelligence In Cancer-Related Malnutrition And Cachexia: A Transformative Tool In Clinical Nutrition, Salvatore Carbone Jan 2025

Artificial Intelligence In Cancer-Related Malnutrition And Cachexia: A Transformative Tool In Clinical Nutrition, Salvatore Carbone

EVMS School of Health Professions Faculty Publications

[Introduction] Malnutrition and cachexia are common complications in cancer patients, and they negatively influence prognosis, treatment efficacy, and tolerability as well as quality of life [[1], [2], [3]]. Accurately identifying and effectively managing malnutrition and cachexia in this population remains a clinical challenge. Conventional validated screening tools may lack the sensitivity and specificity required for early detection and personalized intervention in diverse cancer types and treatment settings [4,5]. Over the last decade, the use of artificial intelligence (AI), including machine learning (ML) and deep learning (DL) strategies, has shown promising results in clinical nutrition, with the potential to revolutionize nutritional …

Go to article

Diverticulitis—New Evidence To Share With Patients, Nicholas B. D'Alessandro, Tarun Vippa, Edward C. Oldfield Iv, David A. Johnson Jan 2025

Diverticulitis—New Evidence To Share With Patients, Nicholas B. D'Alessandro, Tarun Vippa, Edward C. Oldfield Iv, David A. Johnson

Department of Medicine Faculty Publications

Diverticulitis is one of the most common gastrointestinal causes of hospitalization in Western society. While previously characterized as a disease of older patients, new literature highlights an increasing incidence among the younger population. Over the past few decades, the understanding of etiology and management of diverticulitis has changed drastically. New data refute past beliefs while promoting other novel recommendations to mitigate incidence and subsequent complications. Data now confirms the safety and possible protective benefit of particulate food, while highlighting evidence-based approaches for the use of diagnostic imaging and antibiotics. We recognize modifiable and non-modifiable risk factors that are commonly seen …

Go to article

Automation To Autonomy: Temporal Dynamics Of Trust And Visual Attention Allocation Did Not Evolve, Tetsuya Sato, Eric Chancey, Yusuke Yamani Jan 2025

Automation To Autonomy: Temporal Dynamics Of Trust And Visual Attention Allocation Did Not Evolve, Tetsuya Sato, Eric Chancey, Yusuke Yamani

Psychology Faculty Publications

Emerging work environments are expected to implement autonomy that performs various functions without human input. Previous works has shown that trust in automation is negatively correlated with visual attention allocation, indicating that trust is a dynamic construct. Moreover, trust in automation and trust in autonomy appears to evolve in similar ways. However, recent work has demonstrated differences between trust in automation and trust in autonomy within Kaber’s (2018) theoretical framework (Sato et al., 2023b). Yet, it is uncertain whether the development of trust and visual attention allocation differs between automation and autonomy. The present study examined the temporal dynamics of …

Go to article

The Short And Sweet On Sodium-Glucose Cotransporter Inhibitors And Glucagon-Like Peptide-1 Receptor Agonists In Heart Failure, Jose L. Batista, Tracy Makuvire, Jonathan D. Davis, Salvatore Carbone Jan 2025

The Short And Sweet On Sodium-Glucose Cotransporter Inhibitors And Glucagon-Like Peptide-1 Receptor Agonists In Heart Failure, Jose L. Batista, Tracy Makuvire, Jonathan D. Davis, Salvatore Carbone

EVMS School of Health Professions Faculty Publications

Heart failure (HF) affects 6 million people in the US, and type 2 diabetes (T2D) is a significant risk factor for HF. Since 2008, regulatory agencies have required cardiovascular safety trials for new T2D therapies, and these have consistently demonstrated the cardiovascular benefits of glucose-lowering drugs. Sodium-glucose cotransporter inhibitors (SGLTi) and glucagon-like peptide-1 (GLP-1) receptor agonists (RAs)/glucose-dependent insulinotropic polypeptide (GIP) reduce major adverse cardiovascular events and deaths, regardless of diabetes status, and improve cardiorespiratory fitness. SGLTis, such as dapagliflozin and empagliflozin, benefit patients with reduced and preserved ejection fraction, significantly reducing HF hospitalizations and cardiovascular deaths. The DAPA-HF and EMPEROR-Reduced …

Go to article

Analyzing Visual Attention In Virtual Crime Scene Investigations Using Eye-Tracking And Vr: Insights For Cognitive Modeling, Wen-Chao Yang, Chih-Hung Shih, Jiajun Jiang, Sergio Pallas Enguita, Chung-Hao Chen Jan 2025

Analyzing Visual Attention In Virtual Crime Scene Investigations Using Eye-Tracking And Vr: Insights For Cognitive Modeling, Wen-Chao Yang, Chih-Hung Shih, Jiajun Jiang, Sergio Pallas Enguita, Chung-Hao Chen

Electrical & Computer Engineering Faculty Publications

Understanding human perceptual strategies in high-stakes environments, such as crime scene investigations, is essential for developing cognitive models that reflect expert decision-making. This study presents an immersive experimental framework that utilizes virtual reality (VR) and eye-tracking technologies to capture and analyze visual attention during simulated forensic tasks. A 360° panoramic crime scene, constructed using the Nikon KeyMission 360 camera, was integrated into a VR system with HTC Vive and Tobii Pro eye-tracking components. A total of 46 undergraduate students aged 19 to 24–23, from the National University of Singapore in Singapore and 23 from the Central Police University in Taiwan—participated …

Go to article

Development Of 2d Microfluidics Surface With Low-Frequency Electric Fields For Cell Separation Applications, Madushan Wickramasinghe, Dharmakeerthi Nawarathna Jan 2025

Development Of 2d Microfluidics Surface With Low-Frequency Electric Fields For Cell Separation Applications, Madushan Wickramasinghe, Dharmakeerthi Nawarathna

Electrical & Computer Engineering Faculty Publications

Cell separation techniques are widely used in many biomedical and clinical applications for the development of screening, diagnosis and therapeutic tests. Current 3D microfluidics-based cell separation methods have limited applications in part due to low throughput and technical complexity. To address these critical needs, we have developed a 2D microfluidics surface which is the miniaturized version of a 3D microfluids cell separation device. Using low-frequency electric fields (1–10 Vpp and 1 kHz–20 MHz), we have first studied dielectrophoresis, AC electro-osmosis and capillary flow within a sessile drop, and finally utilized the results to develop the 2D cell separation surface. Our …

Go to article

Flux-Weakening Control Methods For Permanent Magnet Synchronous Machines In Electric Vehicles At High Speed, Samer Alwaqfi, Mohamad Alzayed, Hicham Chaoui Jan 2025

Flux-Weakening Control Methods For Permanent Magnet Synchronous Machines In Electric Vehicles At High Speed, Samer Alwaqfi, Mohamad Alzayed, Hicham Chaoui

Electrical & Computer Engineering Faculty Publications

Permanent magnet synchronous motors (PMSMs) are widely favored by manufacturers for use in electric vehicles (EVs) because of their many benefits, which include high power density at high speeds, ruggedness, potential for high efficiency, and reduced control complexity. However, since the Back Electromotive Force (EMF) increases proportionally with the motor’s rotational speed, it must be carefully controlled at high speeds. Flux-weakening (FW) control is required to avoid excessive electromagnetic flux beyond the power source and inverter’s voltage restrictions. This paper aims to compare various FW control strategies and analyze their effectiveness in maximizing the speed of PMSMs in EV applications …

Go to article

Tidal Flooding Contributes To Eutrophication: Constraining Nonpoint Source Inputs To An Urban Estuary Using A Data Driven Statistical Model, Alfonso Macías-Tapia, Margaret R. Mulholland, Corday R. Selden, Sophie Clayton, Peter W. Bernhardt, Thomas R. Allen Jan 2025

Tidal Flooding Contributes To Eutrophication: Constraining Nonpoint Source Inputs To An Urban Estuary Using A Data Driven Statistical Model, Alfonso Macías-Tapia, Margaret R. Mulholland, Corday R. Selden, Sophie Clayton, Peter W. Bernhardt, Thomas R. Allen

OES Faculty Publications

In coastal urban areas, tidal flooding brings water carrying nutrients and particles back from land to estuarine and coastal waters. A statistical model to predict nutrient loads during tidal flooding events can help estimate nutrient loading from previous and future flooding events and adapt nutrient reduction strategies. We measured concentrations of dissolved inorganic nitrogen and phosphorus in floodwater at seven sentinel sites during 15 tidal flooding events from January 2019 to September 2020. The study area was the Lafayette River watershed in Norfolk, VA, USA, which is prone to tidal flooding and is predicted to experience more frequent and intense …

Go to article

Organic Carbon Decay Mediated By A Mesopelagic Microbial Community: The Relevance Of Carbon Pools And Broad Biochemical Composition, Noah J. Craft, Alexander B. Bochdansky Jan 2025

Organic Carbon Decay Mediated By A Mesopelagic Microbial Community: The Relevance Of Carbon Pools And Broad Biochemical Composition, Noah J. Craft, Alexander B. Bochdansky

OES Faculty Publications

The mesopelagic zone is a site of strong microbially driven particle attenuation with depth and thus plays a crucial role in controlling the transfer efficiency of the ocean's biological pump. However, little quantitative information exists on the dependency of decay processes on the source material. Here we followed the decay of ¹⁴C-labeled dead particulate organic carbon (POC) and dissolved organic carbon (DOC) from three different phytoplankton species, and two incubations of live diatoms, in mesopelagic water over 3 months. Commonly used first-order kinetics failed to adequately describe the decay of organic material as rate constants varied from day to day. …

Go to article

Sandy Subterranean Estuaries Minimize Groundwater Nitrogen Pollution Impacts On Coastal Waters, Xiaogang Chen, Isaac R. Santos, Jinzhou Du, Bochao Xu, Joseph J. Tamborski, Ding He, Neven Cukrov, Christian J. Sanders, Jianan Liu, Peiyuan Zhu, Yan Zhang, Ling Li Jan 2025

Sandy Subterranean Estuaries Minimize Groundwater Nitrogen Pollution Impacts On Coastal Waters, Xiaogang Chen, Isaac R. Santos, Jinzhou Du, Bochao Xu, Joseph J. Tamborski, Ding He, Neven Cukrov, Christian J. Sanders, Jianan Liu, Peiyuan Zhu, Yan Zhang, Ling Li

OES Faculty Publications

Widespread anthropogenic activities pollute groundwater that eventually seeps out to the coastal ocean. Here, we resolve nutrient transformations and fluxes in 11 sandy subterranean estuaries (STEs) with contrasting nutrient sources and development trajectories. Coastal groundwater nitrogen pollution stems from sewage discharge and land use change. Anthropogenically derived groundwater nutrient fluxes with high N/P ratios (∼170) accounted for 22%–61% of riverine inputs into China's coastal waters, providing an additional source of nutrients that can fuel coastal eutrophication and algal blooms. Sandy STEs remarkably attenuated ∼84% of nitrogen pollution, minimizing the impact of submarine groundwater discharge (SGD) on coastal water quality. Hence, …

Go to article

Dust Deposition To The Sargasso Sea: A Comparison Of Estimates Using Aluminum In The Surface Ocean Versus Aerosols And Rainwater, T. E. Williams, P. N. Sedwick, B. M. Sohst, K. N. Buck, S. Caprara, R. J. Johnson, D. C. Ohnemus, J. A. Resing, L. E. Sofen, A. Tagliabue, B. S. Twining Jan 2025

Dust Deposition To The Sargasso Sea: A Comparison Of Estimates Using Aluminum In The Surface Ocean Versus Aerosols And Rainwater, T. E. Williams, P. N. Sedwick, B. M. Sohst, K. N. Buck, S. Caprara, R. J. Johnson, D. C. Ohnemus, J. A. Resing, L. E. Sofen, A. Tagliabue, B. S. Twining

OES Faculty Publications

As a major component of mineral aerosol that partially dissolves in seawater, aluminum (Al) has been used to estimate time-averaged dust fluxes to the ocean, based on dissolved aluminum (DAl) concentrations and an assumed replacement time of DAl (tau DAl) in the surface mixed layer, along with the fractional solubility (Als) and mass abundance of Al in dust. We apply this method in the Bermuda region using seasonal water-column DAl concentrations, and compare our results with fluxes estimated from Al measured in Bermuda aerosols and rain. Inventories of DAl over the maximum mixed-layer depth of 200 m and empirically derived …

Go to article

Evidence Of Mineral Alteration In A Salt Marsh Subterranean Estuary: Implications For Carbon And Trace Element Cycling, J. J. Tamborski, M. J. Eagle, M. T. Thorpe, M. A. Charette, B. L. Kurylyk, S. Rahman, K. D. Kroeger, J. O'Keefe Suttles, A. G. Mann, T. W. Brooks, Z. A. Wang Jan 2025

Evidence Of Mineral Alteration In A Salt Marsh Subterranean Estuary: Implications For Carbon And Trace Element Cycling, J. J. Tamborski, M. J. Eagle, M. T. Thorpe, M. A. Charette, B. L. Kurylyk, S. Rahman, K. D. Kroeger, J. O'Keefe Suttles, A. G. Mann, T. W. Brooks, Z. A. Wang

OES Faculty Publications

Subterranean estuaries (STE) in salt marshes are biogeochemically active zones where interactions between terrestrial groundwater and seawater drive complex cycling of carbon and trace elements, influenced by mineral dissolution. These systems, characterized by fine-grained organic-rich peat overlying permeable coastal aquifers, play a crucial role as a blue carbon sink, yet their geochemical dynamics remain poorly understood. We investigated dissolved trace elements, carbon, silica, and radium isotopes in a salt marsh STE (Sage Lot Pond, Waquoit Bay, MA) over seasonal and annual cycles. Our results reveal that groundwater and estuarine water circulation through marsh peat and aquifer sediments leads to enrichments …

Go to article

The Δ¹³C Signature Of Dissolved Organic And Inorganic Carbon Reveals Complex Carbon Transformations Within A Salt Marsh, Meagan J. Eagle, Kevin D. Kroeger, John W. Pohlman, Joseph J. Tamborski, Zhaohui Aleck Wang, T. W. Brooks, Jennifer O. Keefe Suttles, Adrian Mann Jan 2025

The Δ¹³C Signature Of Dissolved Organic And Inorganic Carbon Reveals Complex Carbon Transformations Within A Salt Marsh, Meagan J. Eagle, Kevin D. Kroeger, John W. Pohlman, Joseph J. Tamborski, Zhaohui Aleck Wang, T. W. Brooks, Jennifer O. Keefe Suttles, Adrian Mann

OES Faculty Publications

Coastal wetlands have high rates of atmospheric CO₂ uptake, which is subsequently respired back to the atmosphere, stored as organic matter within flooded, anoxic soils, or exported to the coastal ocean. Transformation of fixed carbon occurs through a variety of subsurface aerobic and anaerobic microbial processes, and results in a large inventory of dissolved carbon. Carbon source and the roles of aerobic respiration, sulfate reduction, and methane cycling were evaluated within salt marsh peat and the underlying sandy subterranean estuary. There is a large increase in dissolved inorganic carbon (DIC, 7,350 ± 3,900 μmol L-¹), dissolved organic carbon …

Go to article

Characterization Of Microbial Biofilms On Marine Plastics: Community Development And Density Implications For Vertical Transport Dynamics, Gregory M. Joern, Rut Pedrosa-Pàmies, Xiangtao Jiang, Zhanfei Liu, Alexander B. Bochdansky Jan 2025

Characterization Of Microbial Biofilms On Marine Plastics: Community Development And Density Implications For Vertical Transport Dynamics, Gregory M. Joern, Rut Pedrosa-Pàmies, Xiangtao Jiang, Zhanfei Liu, Alexander B. Bochdansky

OES Faculty Publications

Marine plastic pollution poses a significant and escalating threat to ocean ecosystems, with microbial colonization on plastics playing a critical role in determining their environmental fate. Despite the recognized importance of microbial biofilms, their composition, dynamics, and functional contributions on buoyant plastics remain poorly understood. In this study, we leveraged a novel integrative approach by simultaneously employing 16S, 18S, and ITS sequencing alongside microscopy, lipidomics, pigment analysis, adenosine triphosphate and biogenic silica quantification. This comprehensive methodology allowed for a thorough characterization of microbial growth and community dynamics on plastic debris in a mid-latitude, tidal sub-estuary. Our analyses consistently identified diatoms, …

Go to article

The Effect Of Temperature And Salinity On Margalefidinium Polykrikoides Group Iii Va, Usa Strain Growth, Eduardo Pérez-Vega, Margaret R. Mulholland, Katherine E. Crider, Kimberly E. Powell, P. Dreux Chappell, Alexander Bochdansky Jan 2025

The Effect Of Temperature And Salinity On Margalefidinium Polykrikoides Group Iii Va, Usa Strain Growth, Eduardo Pérez-Vega, Margaret R. Mulholland, Katherine E. Crider, Kimberly E. Powell, P. Dreux Chappell, Alexander Bochdansky

OES Faculty Publications

Margalefidinium polykrikoides is a cosmopolitan dinoflagellate that blooms in coastal waters. Despite genomic evidence that it belongs to Group III and so closely related to isolates from Puerto Rico, Malaysia, North America, and Central America, M. polykrikoides blooms in the Chesapeake Bay at warmer temperatures and lower salinities than in coastal ecosystems occupied by its closest relatives. In this study, the effect of temperature and salinity on the growth rate and total cell yield of an M. polykrikoides VA culture isolate were examined and compared with environmental observations made during M. polykrikoides blooms in the Chesapeake Bay. M. polykrikoides group …

Go to article

Seasonality Of Submarine Groundwater Discharge Pathways In A Coastal Lagoon Revealed By Radium Isotopes: The Importance Of Porewater Exchange In Summer, Júlia Rodriguez-Puig, Valentí Rodellas, Marc Diego-Feliu, Andres Alcolea, Joaquín Jiménez-Martínez, Irene Alorda-Montiel, Aaron Alorda-Kleinglass, Francisco Pereira, Marisol Manzano, Javier Gilabert, Jordi Garcia-Orellana Jan 2025

Seasonality Of Submarine Groundwater Discharge Pathways In A Coastal Lagoon Revealed By Radium Isotopes: The Importance Of Porewater Exchange In Summer, Júlia Rodriguez-Puig, Valentí Rodellas, Marc Diego-Feliu, Andres Alcolea, Joaquín Jiménez-Martínez, Irene Alorda-Montiel, Aaron Alorda-Kleinglass, Francisco Pereira, Marisol Manzano, Javier Gilabert, Jordi Garcia-Orellana

OES Faculty Publications

Chemical fluxes supplied by Submarine Groundwater Discharge (SGD) can be relevant for coastal ecosystems, particularly lagoonal environments. An appropriate understanding of SGD requires constraining the magnitude and composition of its different pathways. However, the evaluation of SGD pathways is often limited to independent estimations, lacking a comprehensive understanding of the groundwater processes at play. In this study, we combined a Ra mass balance and hydrogeological modeling to simultaneously estimate different SGD pathways flowing into a coastal lagoon. We assessed water fluxes derived from fresh SGD, long-scale recirculation of seawater, and porewater exchange (PEX) into Mar Menor, a highly anthropized coastal …

Go to article

Optimizing An Image Analysis Protocol For Ocean Particles In Focused Shadowgraph Imaging Systems, Huanqing Huang, Alexander B. Bochdansky Jan 2025

Optimizing An Image Analysis Protocol For Ocean Particles In Focused Shadowgraph Imaging Systems, Huanqing Huang, Alexander B. Bochdansky

OES Faculty Publications

A variety of imaging systems are in use in oceanographic surveys, and the opto-mechanical configurations have become highly sophisticated. However, much less consideration has been given to the accurate reconstruction of imaging data. To improve reconstruction of particles captured by Focused Shadowgraph Imaging (FoSI)—a system that excels at visualizing low-optical-density objects, we developed a novel object detection algorithm to process images with a resolution of ~ 12 μm per pixel. Suggested improvements to conventional edge-detection methods are relatively simple and time-efficient, and more accurately render the sizes and shapes of small particles ranging from 24 to 500 μm. In addition, …

Go to article

From Wind To Whales: Potential Hydrodynamic Impacts Of Offshore Wind Energy On Nantucket Shoals Regional Ecology, Eileen E. Hofmann, Jeffrey R. Carpenter, Qin J. Chen, Josh T. Kohut, Richard L. Merrick, Erin L. Meyer-Gutbrod, Douglas P. Nowacek, Kaustubha Raghukumar, Nicholas R. Record, Kelly Oskvig Jan 2025

From Wind To Whales: Potential Hydrodynamic Impacts Of Offshore Wind Energy On Nantucket Shoals Regional Ecology, Eileen E. Hofmann, Jeffrey R. Carpenter, Qin J. Chen, Josh T. Kohut, Richard L. Merrick, Erin L. Meyer-Gutbrod, Douglas P. Nowacek, Kaustubha Raghukumar, Nicholas R. Record, Kelly Oskvig

OES Faculty Publications

The National Academy of Sciences, Engineering, and Medicine convened a committee in June 2023 to assess the potential hydrodynamic and ecological impacts from offshore wind energy development in the Nantucket Shoals region, with particular attention to impacts on the critically endangered North Atlantic right whale (Eubalaena glacialis) that forages on zooplankton aggregations in the region. The assessment suggested that the effects of offshore wind energy development will be difficult to distinguish from the effects of natural variability and climate change in this region. The Consensus Study Report recommendations highlight observational and modeling studies that will advance understanding of …

Go to article

A Century Of Sediment Metal Contamination Of Mar Menor, Europe's Largest Saltwater Lagoon, Irene Alorda-Montiel, Valentí Rodellas, Ariane Arias-Ortiz, Albert Palanques, Andrea G. Bravo, Júlia Rodriguez-Puig, Aaron Alorda-Kleinglass, Carlos Green-Ruiz, Marc Diego-Feliu, Pere Masqué, Javier Gilabert, Jordi Garcia-Orellana Jan 2025

A Century Of Sediment Metal Contamination Of Mar Menor, Europe's Largest Saltwater Lagoon, Irene Alorda-Montiel, Valentí Rodellas, Ariane Arias-Ortiz, Albert Palanques, Andrea G. Bravo, Júlia Rodriguez-Puig, Aaron Alorda-Kleinglass, Carlos Green-Ruiz, Marc Diego-Feliu, Pere Masqué, Javier Gilabert, Jordi Garcia-Orellana

OES Faculty Publications

Coastal enclosed ecosystems, such as lagoons, are vulnerable to anthropogenic impacts because they favor the accumulation of contaminants from the surrounding watersheds, particularly in their sediments. Europe's largest saltwater lagoon, the Mar Menor (SE, Iberian Peninsula), is a highly impacted ecosystem and the first in the continent to be granted personhood rights. Based on a high-resolution spatial and temporal dataset, we present the historical reconstruction of metal contamination in this ecosystem during the last century. Our results highlight that sediment metal contamination has been mainly driven by the development of the mining industry in the nearby Sierra Minera de Cartagena-La …

Go to article

Radon And Radium Isotope Signatures On A Massive Ice- And Permafrost-Rich Coastline, Lauren Kipp, Gwénaëlle Chaillou, Markus Kienast, Joseph Tamborski, Dustin Whalen Jan 2025

Radon And Radium Isotope Signatures On A Massive Ice- And Permafrost-Rich Coastline, Lauren Kipp, Gwénaëlle Chaillou, Markus Kienast, Joseph Tamborski, Dustin Whalen

OES Faculty Publications

Rapid warming in the Arctic is degrading permafrost and massive ice deposits, which releases solutes previously trapped in ice and frozen soils into groundwater, rivers, and the coastal ocean. Radium and radon isotopes are enriched in groundwaters and may therefore have utility as tracers for the delivery of permafrost-derived solutes to the ocean, particularly if massive ice- or permafrost-derived meltwaters have a distinct isotopic ratio. The ratio of radium isotopes within massive ice deposits can also be used to constrain timescales of ice segregation, as the four isotopes will decay with known rates once removed from contact with sediments. Here …

Go to article

Ensemble Machine Learning Approaches For Bathymetry Estimation In Multi-Spectral Images, Kazi A. Islam, Omar Abdul-Hassan, Hongfang Zhang, Victoria Hill, Blake Schaeffer, Richard Zimmerman, Jiang Li Jan 2025

Ensemble Machine Learning Approaches For Bathymetry Estimation In Multi-Spectral Images, Kazi A. Islam, Omar Abdul-Hassan, Hongfang Zhang, Victoria Hill, Blake Schaeffer, Richard Zimmerman, Jiang Li

OES Faculty Publications

Traditional bathymetry measures require a large number of human hours, and many bathymetry records are obsolete or missing. Automated measures of bathymetry would reduce costs and increase accessibility for research and applications. In this paper, we optimized a recent machine learning model, named CatBoostOpt, to estimate bathymetry based on high-resolution WorldView-2 (WV-2) multi-spectral optical satellite images. CatBoostOpt was demonstrated across the Florida Big Bend coastline, where the model learned correlations between in situ sound Navigation and Ranging (Sonar) bathymetry measurements and the corresponding multi-spectral reflectance values in WV-2 images to map bathymetry. We evaluated three different feature transformations as inputs …

Go to article

Millennial Pulses Of African Dust And Itcz Shifts In The Eastern Equatorial Pacific, Danielle E. Schimmenti, Franco Marcantonio, M. Roxana Sierra Hernández, Matthew W. Schmidt Jan 2025

Millennial Pulses Of African Dust And Itcz Shifts In The Eastern Equatorial Pacific, Danielle E. Schimmenti, Franco Marcantonio, M. Roxana Sierra Hernández, Matthew W. Schmidt

OES Faculty Publications

We present high-resolution records of detrital Pb and Nd isotopes from marine core site MV1014-02-17JC (00° 10.8297’S, 85° 52.0042’W) in the Eastern Equatorial Pacific (EEP) and use a Bayesian isotope mixing model, MixSIAR, to quantify global dust source contributions since the onset of the last glaciation 30,000 yr ago. We find that in addition to South American dust from the Andean margin, North African dust from the Saharan desert makes up significant proportions of the EEP dust delivered to the site of study. The proportion of North African dust was significantly enhanced during the cold Northern Hemisphere stadials, Heinrich Stadial …

Go to article

Successful Eastern Oyster (Crassostrea Virginica) Recruitment On Intertidal Artificial Substrates In Virginia, Usa, Rochelle D. Seitz, Kathleen E. Knick, Emily Suchonic, Amanda Pysher Jan 2025

Successful Eastern Oyster (Crassostrea Virginica) Recruitment On Intertidal Artificial Substrates In Virginia, Usa, Rochelle D. Seitz, Kathleen E. Knick, Emily Suchonic, Amanda Pysher

OES Faculty Publications

Declines of eastern oyster (Crassostrea virginica) populations and scarcity of natural oyster shell necessitate quantifying the effectiveness of artificial oyster reef substrates over varying environmental conditions. Oyster castles are often used in intertidal areas with moderate wave energy; however, new concrete, natural-looking substrates, GROW Reef Tiles, are now available. Eastern oyster recruitment and size on oyster castles (OC) and GROW Reef Tiles (GT), with 27% higher surface area on OC, were assessed three times over 25 months in locations with varying salinity. Four sites in the Chesapeake Bay region were examined: Cherrystone Inlet, Mockhorn Bay, Elizabeth River, and …

Go to article

First Prev Next Last