Digital Commons Network^™

Why Are There So Many Definitions Of Eutrophication?, Alexandrine Pannard, Philippe Souchu, Christian Chauvin, Monique Delabuis, Chantal Gascuel-Odoux, Erik Jeppesen, Morgane Le Moal, Alain Ménesguen, Gilles Pinay, Nancy N. Rabalais, Yves Souchon, Elisabeth M. Gross

Faculty Publications

Because of the first observations in the 1900s of the oligotrophic and eutrophic states of lakes, researchers have been interested in the process that makes lakes become turbid because of high phytoplankton biomass. Definitions of eutrophication have multiplied and diversified since the mid-20th century, more than for any other ecological process. Reasons for the high number of definitions might be that the former ones did not sufficiently describe their causes and/or consequences. Global change is bringing eutrophication more into the spotlight than ever, highlighting the need to find consensus on a common definition, or at least to explain and clarify …

Key Uncertainties And Modeling Needs For Managing Living Marine Resources In The Future Arctic Ocean, Julia G. Mason, Andrea Bryndum-Buchholz, Juliano Palacios-Abrantes, Renuka Badhe, Isabella Morgante, Daniele Bianchi, Julia L. Blanchard, Jason D. Everett, Cheryl S. Harrison, Ryan F. Heneghan, Camilla Novaglio, Colleen M. Petrik

Faculty Publications

Emerging fishing activity due to melting ice and poleward species distribution shifts in the rapidly-warming Arctic Ocean challenges transboundary management and requires proactive governance. A 2021 moratorium on commercial fishing in the Arctic high seas provides a 16-year runway for improved scientific understanding. Given substantial knowledge gaps, characterizing areas of highest uncertainty is a key first step. Marine ecosystem model ensembles that project future fish distributions could inform management of future Arctic fisheries, but Arctic-specific variation has not yet been examined for global ensembles. We use the Fisheries and Marine Ecosystem Intercomparison Project ensemble driven by two Earth System Models …

Solubilization Of Paclitaxel With Natural Compound Rubusoside Toward Improving Oral Bioavailability In A Rodent Model, Jian Zhang, Jicheng Shu, Rhett W. Stout, Paul S. Russo, Zhijun Liu

Faculty Publications

Paclitaxel, which features low water solubility and permeability, is an efflux pump substrate. The current paclitaxel drugs are given intravenously after resolving the solubility issue. Yet, oral delivery to achieve therapeutic bioavailability is not effective due to low absorption. This study evaluated a natural compound, rubusoside, to improve oral bioavailability in an animal model. Free paclitaxel molecules were processed into nano-micelles formed in water with rubusoside. The particle size of the nano-micelles in water was determined using dynamic light scattering. The oral bioavailability of paclitaxel in nano-micelles was determined against Cremophor/alcohol-solubilized Taxol after oral and intravenous administration to pre-cannulated Sprague …

Youth's Political Identity And Fertility Desires, Heather M. Rackin, Christina M. Gibson-Davis

Faculty Publications

Objective: This study examines the association between political identity and young adults' fertility desires from 1989 to 2019. Background: Understanding the factors that shape fertility preferences is important because these preferences are the critical bridge between social forces and fertility. Identity is a theorized, but understudied, predictor of fertility desires. The increasing salience of political identity suggests that the association between political identity and fertility desires has strengthened over time. Method: Data come from the 1989–2019 waves of Monitoring the Future, a nationally representative study of 12th graders (N = 67,557). Regression models examined how political identity (measured by Republican …

Response Of A Terrestrial Polar Ecosystem To The March 2022 Antarctic Weather Anomaly, J. E. Barrett, Byron J. Adams, Peter T. Doran, Hilary A. Dugan, Krista F. Myers, Mark R. Salvatore, Sarah N. Power, Meredith D. Snyder, Anna T. Wright, Michael N. Gooseff

Faculty Publications

Record high temperatures were documented in the McMurdo Dry Valleys, Antarctica, on 18 March 2022, exceeding average temperatures for that day by nearly 30°C. Satellite imagery and stream gage measurements indicate that surface wetting coincided with this warming more than 2 months after peak summer thaw and likely exceeded thresholds for rehydration and activation of resident organisms that typically survive the cold and dry conditions of the polar fall in a freeze-dried state. This weather event is notable in both the timing and magnitude of the warming and wetting when temperatures exceeded 0°C at a time when biological communities and …

Effects Of Exercise Or Metformin On Myokine Concentrations In Patients With Breast And Colorectal Cancer: A Phase Ii Multi-Centre Factorial Randomized Trial, Justin C. Brown, Guillaume Spielmann, Shengping Yang, Stephanie L.E. Compton, Lee W. Jones, Melinda L. Irwin, Jennifer A. Ligibel, Jeffrey A. Meyerhardt

Faculty Publications

Background: Physical activity and metformin pharmacotherapy are associated with improved clinical outcomes in breast and colorectal cancer survivors. Myokines are cytokines secreted from skeletal muscle that may mediate these associations. Methods: This hypothesis-generating analysis used biospecimens collected from a multi-centre 2 × 2 factorial randomized design of 116 patients with stage I–III breast and colorectal cancer who were randomized to 12 weeks of (1) aerobic exercise (moderate intensity titrated to 220 min/week); (2) metformin (850 mg daily for 2 weeks and then titrated to 850 mg twice per day); (3) aerobic exercise and metformin; or (4) control. Fourteen myokines were …

Boron Neutron Capture Therapy Of Cancer: Where Do We Stand Now?, Rolf F. Barth, Gong Wu, Maria Da Graca H. Vicente, John C. Grecula, Nilendu Gupta

Faculty Publications

No abstract provided.

Acute Pancreatitis In Individuals With Sickle Cell Disease: A Systematic Review, Chinenye R. Dike, Adefunke Dadematthews, Oluwagbemiga Dadematthews, Maisam Abu-El-Haija, Jeffrey Lebensburger, Abigail Smith, Aamer Imdad

Faculty Publications

Background/Objectives: Sickle cell disease (SCD) impacts about 100,000 people in the US. SCD increases the risk of cholelithiasis and microvascular ischemia, which could increase the risk of acute pancreatitis (AP). Abdominal pain is a common presenting symptom of AP and sickle cell vaso-occlusive crisis. The purpose of our systematic review is to estimate the prevalence and determine the severity of AP in individuals with SCD compared to the general population. Methods: Multiple electronic databases were searched. We included studies that included children and adults (population) and addressed the association of SCD (exposure) with AP (outcome) compared to the same population …

Learning Nonlinear Dynamics In Synchronization Of Knowledge-Based Leader-Following Networks, Shimin Wang, Xiangyu Meng, Hongwei Zhang, Frank L. Lewis

Faculty Publications

Knowledge-based leader-following synchronization of heterogeneous nonlinear multi-agent systems is a challenging problem since the leader's dynamic information is unknown to any follower node. This paper proposes a learning-based fully distributed observer for a class of nonlinear leader systems, which can simultaneously learn the leader's dynamics and states. This class of leader dynamics is rather general and does not require a bounded Jacobian matrix. Based on this learning-based distributed observer, we further synthesize an adaptive distributed control law for solving the leader-following synchronization problem of multiple Euler–Lagrange systems subject to an uncertain nonlinear leader system. The results are illustrated by a …

Lipids To The Rescue In Pulmonary Fibrosis: Biosynthesis, Bioenergetics, Or Epigenetics?, Manas Ranjan Gartia, Victor J. Thannickal

Faculty Publications

No abstract provided.

Hyperpolarized Magnetic Resonance Imaging, Nuclear Magnetic Resonance Metabolomics, And Artificial Intelligence To Interrogate The Metabolic Evolution Of Glioblastoma, Kang Lin Hsieh, Qing Chen, Travis C. Salzillo, Jian Zhang, Xiaoqian Jiang, Pratip K. Bhattacharya, Shyan Shams

Faculty Publications

Glioblastoma (GBM) is a malignant Grade VI cancer type with a median survival duration of only 8–16 months. Earlier detection of GBM could enable more effective treatment. Hyperpolarized magnetic resonance spectroscopy (HPMRS) could detect GBM earlier than conventional anatomical MRI in glioblastoma murine models. We further investigated whether artificial intelligence (A.I.) could detect GBM earlier than HPMRS. We developed a deep learning model that combines multiple modalities of cancer data to predict tumor progression, assess treatment effects, and to reconstruct in vivo metabolomic information from ex vivo data. Our model can detect GBM progression two weeks earlier than conventional MRIs …

The Impact Of Lutein-Loaded Poly(Lactic-Coglycolic Acid) Nanoparticles Following Topical Application: An In Vitro And In Vivo Study, Renee T. Carter, Sean Swetledge, Sara Navarro, Chin C. Liu, Nikole Ineck, Andrew C. Lewin, Fabrizio Donnarumma, Ede Bodoki, Rhett W. Stout, Carlos Astete, Jangwook P. Jung, Cristina M. Sabliov

Faculty Publications

Antioxidant therapies are of interest in the prevention and management of ocular disorders such as cataracts. Although an active area of interest, topical therapy with antioxidants for the treatment of cataracts is complicated by multiple ocular anatomical barriers, product stability, and solubility. Entrapment and delivery of antioxidants with poly(lactic-co-glycolic acid) nanoparticles is a possible solution to these challenges, however, little is known regarding their effects in vitro or in vivo. Our first aim was to investigate the impact of blank and lutein loaded PLGA nanoparticles on viability and development of reactive oxygen species in lens epithelial cells in vitro. Photo-oxidative …

Impact Of Aureobasidium Species Strain Improvement On The Production Of The Polysaccharide Pullulan, Thomas P. West

Faculty Publications

This review explores the production of the fungal polysaccharide pullulan by mutants and natural isolates of Aureobasidium species using strain improvement. Pullulan is a neutral polysaccharide gum whose structure is a maltotriose-containing glucan. This polysaccharide gum has applications in the fields of food, pharmaceuticals, biomedical and wastewater treatment. The strain improvement of Aureobasidium species has focused on the pullulan production process, including the isolation of strains exhibiting reduced pigmentation, polysaccharide overproduction, the production of pullulan with variable molecular weight, and increased osmotolerant strains promoting pullulan production at high carbon source concentrations and pullulan production on hemicellulosic substrates. The majority of …

Development And Validity Of The 'Modified Mediterranean Prime Screen' To Assess Dietary Intake Among Women Of Reproductive Age In Lebanon, Mariam Assaad, Sara Ajjour, Maya Rahme, Laila Al-Shaar, May Sakr, Hala Ghattas Ph.D., Ghada El-Hajj Fuleihan, Jana Jabbour

Faculty Publications

The Mediterranean Region registers an increasing prevalence of obesity. The region lacks a diet screener to assess obesogenic nutrients. This study aimed to evaluate the reproducibility and validity of the Modified Mediterranean Prime Screen (MMPS) in estimating obesogenic nutrients' intake among women of reproductive age, as compared with a culturally validated Food Frequency Questionnaire (FFQ), in Lebanon. We developed the MMPS consisting of thirty-two food/beverage items specific to the Lebanese Mediterranean culture. The MMPS and FFQ were administered in two visits (2 weeks-6 months apart), face to face and via telephone during the coronavirus disease 2019 pandemic. The reproducibility and …

The Role Of Biological Plasticity In Model-Based Translational Research, Jessica A. Bolker

Faculty Publications

Reports of low replicability and translatability of biomedical research have called the value of animal models into question. The problems are real, but abandoning animal research is not the solution. Rather, improving the translatability of model-based research requires attention to relevant differences between humans and models, and to attributes of the models themselves that are essential to both robust science and effective translation. One is biological plasticity, the responsiveness of individual organisms to complex and variable environments. Though under-represented in model systems (for both historical and practical reasons), plasticity is central to human biology. While there are good reasons to …

Ion-Mediated Structural Discontinuities In Phospholipid Vesicles, Judith U. De Mel, Stefanie Klisch, Sudipta Gupta, Gerald J. Schneider

Faculty Publications

Despite intense research, methods for controlling soft matter’s spontaneous self-assembly into well-defined layers remain a significant challenge. We observed ion-induced structural discontinuities of phospholipid vesicles that can be exploited for controlled self-assembly of soft materials, using DOPC and NaCl as a model system. The observations were made for the 0.25 wt % lipid concentration. We used dynamic light scattering, zeta-potential measurement, cryo-electron microscopy, small-angle X-ray, and small-angle neutron scattering to understand the reason for the discontinuities. For salt concentrations below 8 mM, we observed a decrease in the liposome diameter with increased NaCl concentration. Above 8 mM, we measured a …

The Radiative And Geometric Properties Of Melting First-Year Landfast Sea Ice In The Arctic, Nathan J. M. Laxague, Christopher J. Zappa, Andrew R. Mahoney, John Goodwin, Cyrus Harris, Robert E. Schaeffer, Roswell Schaeffer, Sarah Betcher, Donna D W Hauser, Carson R. Witte, Jessica M. Lindsay, Ajit Subramaniam, Kate E. Turner, Alex Whiting

Faculty Publications

In polar regions, sea ice is a crucial mediator of the interaction between Earth's atmosphere and oceans. Its formation and breakup is intimately connected with large-scale climatic processes, local weather patterns, and the use of sea ice in coastal Arctic regions by Indigenous people. In order to investigate the physical phenomena at the heart of this process, a set of targeted, intensive observations were made over spring sea ice melt and breakup in Kotzebue Sound, Alaska. These observations were planned and executed through a collaborative effort in which an Indigenous Elder advisory council from Kotzebue and scientists participated in co-production …

Effect Of Local Chain Stiffness On Oligomer Crystallization From A Melt, Pierre Kawak, Christopher Akiki, Douglas R. Tree

Faculty Publications

While the process by which a polymer crystal nucleates from the melt has been extensively studied via molecular simulation, differences in polymer models and simulated crystallization conditions have led to seemingly contradictory results. We make steps to resolve this controversy by computing low-temperature phase diagrams of oligomer melts using Wang-Landau Monte Carlo simulations. Two qualitatively different crystallization mechanisms are possible depending on the local bending stiffness potential. Polymers with a discrete bending potential crystallize via a single-step mechanism, whereas polymers with a continuous bending potential can crystallize via a two-step mechanism that includes an intermediate nematic phase. Other model differences …

A Model-Based Reverse System Engineering Methodology For Analyzing Complex Biological Systems With A Case Study In Glycolysis, Gerald L. Fudge, Emily Brown Reeves

Faculty Publications

We propose a model-based reverse systems engineering (MBRSE) methodology for biological systems that relies on requirements analysis in conjunction with model-based systems engineering (MBSE). The goal of this methodology is to better understand complex multiscale biological systems, discover knowledge gaps, and make testable predictions. The similarities between human-engineered and biological systems motivate this approach. Furthermore, traditional reductionist paradigms in biology have proven insufficient for understanding and accurately predicting complex biological systems, as opposed to systems engineering approaches that have proven effective in supporting the design and analysis of complex engineered systems spanning multiple spatiotemporal scales. We employ our MBRSE methodology …

Revisiting The Preparation And Catalytic Performance Of A Phosphine-Modified Co(Ii) Hydroformylation Precatalyst, David R. Holzknecht, Alexandra K. Van Alstine, Brandon P. Russell, David J. Vinyard, Fabrizio Donnarumma, Matthew B. Chambers

Faculty Publications

In light of recent conflicting reports regarding the hydroformylation catalytic activity derived from cationic Co(II) precatalysts of the form [Co(acac)(bis(phosphine))]BF4, the synthetic procedures and characterization of [Co(acac)(dppBz)]BF4, 1, are evaluated. Leveraging calibrated ESI-TOF MS methodologies, substantial quantities of Co(acac)2(dppBz), 2, were observed within samples of 1. The source of the impurity, 2, is determined to derive from incomplete protonolysis of the Co(acac)2 precursor and ligand scrambling occurring during the synthesis of 1. Revised synthetic procedures using lower temperature conditions and longer reaction times afford analytically pure samples of 1 based on ESI-TOF MS and NMR spectroscopic analysis. Complex 1 is …

Unveiling Competitive Adsorption In Tio2 Photocatalysis Through Machine-Learning-Accelerated Molecular Dynamics, Dft, And Experimental Methods, Omar Allam, Mostafa Maghsoodi, Seung Soon Jang, Samuel D. Snow

Faculty Publications

The efficient harnessing of solar power for water treatment via photocatalytic processes has long been constrained by the challenge of understanding and optimizing the interactions at the photocatalyst surface, particularly in the presence of nontarget cosolutes. The adsorption of these cosolutes, such as natural organic matter, onto photocatalysts can inhibit the degradation of pollutants, drastically decreasing the photocatalytic efficiency. In the present work, computational methods are employed to predict the inhibitory action of a suite of small organic molecules during TiO2 photocatalytic degradation of para-chlorobenzoic acid (pCBA). Specifically, tryptophan, coniferyl alcohol, succinic acid, gallic acid, and trimesic acid were selected …

Exploring The Role Of Disciplinary Knowledge In Students' Covariational Reasoning During Graphical Interpretation, Nigar Altindis, Kathleen A. Bowe, Brock Couch, Christopher F. Bauer, Melissa L. Aikens

Faculty Publications

Background: This study investigates undergraduate STEM students’ interpretation of quantities and quantitative relationships on graphical representations in biology (population growth) and chemistry (titration) contexts. Interviews (n = 15) were conducted to explore the interplay between students’ covariational reasoning skills and their use of disciplinary knowledge to form mental images during graphical interpretation.

Results: Our findings suggest that disciplinary knowledge plays an important role in students’ ability to interpret scientific graphs. Interviews revealed that using disciplinary knowledge to form mental images of represented quantities may enhance students’ covariational reasoning abilities, while lacking it may hinder more sophisticated covariational reasoning. Detailed descriptions …

Ready, Set, Grow: From Micelles To Giant Vesicles Via Biocatalytic Activation, Nicholas P. Bair, Qinyu Zhu, Bryon A. Staynings, Douglas R. Tree, Walter F. Paxton

Faculty Publications

Controlling physicochemical processes that drive changes in supramolecular aggregates is an important objective toward creating artificial soft micro- and nanomachines. Previous research explored the morphology control of membrane-based materials subjected to externally imposed chemical stimuli. Here, we modulate the microscale morphology of pH-responsive assemblies by using biocatalysis to internally generate changes in global pH. Catalytic reactions offer flexibility in the mechanism and rate at which stimuli are introduced to responsive assemblies, ultimately enabling precision and control over size and morphology. We observed, by dynamic light scattering and fluorescence microscopy, substantial microscale differences between assemblies subjected to manually titrated pH changes …