Digital Commons Network^™

Prevalence And Associated Factors Of Excessive Recreational Screen Time Among Colombian Children And Adolescents, Silvia A. González, Olga L. Sarmiento, Alberto Florez-Pregonero, Peter T. Katzmarzyk, Jean Philippe Chaput, Mark S. Tremblay

Population and Public Health Science Faculty Publications

Objectives: Excessive recreational screen time (RST) is associated with detrimental effects for physical, psychological and cognitive development. This article aims to describe the prevalence of excessive RST among Colombian preschoolers, children and adolescents and explore its factors associated. Methods: We analyzed data from the National Survey of Nutrition 2015. The sample included 4,503 preschoolers, 5,333 school-aged children and 6,623 adolescents. Poisson regression models with robust variance were conducted to estimate prevalence ratios and determine associated factors of excessive RST. Results: Fifty percent of preschoolers, 61% of school-aged children and 73% of adolescents in Colombia had excessive RST. Positive associations were …

New Limit Theorems For Increments Of Birth-And-Death Processes With Linear Rates, Alexander Ya. Kreinin, Vladimir V. Vinogradov

Journal of Stochastic Analysis

No abstract provided.

Backward Stochastic Differential Equations With No Driving Martingale And Pseudo-Pdes, Adrien Barrasso, Francesco Russo

Journal of Stochastic Analysis

No abstract provided.

Analysis And Simulation Of Energy Performances Of Additive Manufacturing Systems, Mohammad Hassan

LSU Doctoral Dissertations

Additive manufacturing (AM) is an evolving technology that offers distinct advantages over conventional subtractive manufacturing by fabricating a variety of complex-shaped parts with mass customization. Selective laser melting (SLM), electron beam melting (EBM), and fused filament fabrication (FFF) are popular AM processes. A recent growing trend in AM suggests the necessity of an energy study to explore energy performance measures. In this research, a comprehensive energy study is performed for various AM processes with three objectives. The first objective of this study is to assess relationships between energy performance measures and two key process parameters (infill patterns and infill percentages) …

Infrared Investigation Of Lithium Ion Electrolytes: Characterization Of Structure And Dynamics Via Linear And Nonlinear Spectroscopy, Jeramie Christopher Rushing

LSU Doctoral Dissertations

Lithium ion batteries are widely employed in energy storage, but the connection between the molecular interactions in their electrolytes and the macroscopic properties remains elusive. Across three vastly different electrolytes, speciation and dynamics were studied via linear and nonlinear infrared spectroscopy to shed light on this relationship. The impact of mixed solvation on ionic speciation was studied from the perspective of the anion, which revealed a significant energetic favorability for the formation of contact ion pairs in linear carbonate solvents over cyclic carbonates. Infrared spectroscopy and density functional theory calculations described a complete inversion of the speciation due to solvent …

Exploring The Effects Of Genetic Variation On Gene Regulation In Cancer In The Context Of 3d Genome Structure, N Osman, A M. Shawky, M Brylinski

Faculty Publications

Background Numerous genome-wide association studies (GWAS) conducted to date revealed genetic variants associated with various diseases, including breast and prostate cancers. Despite the availability of these large-scale data, relatively few variants have been functionally characterized, mainly because the majority of single-nucleotide polymorphisms (SNPs) map to the non-coding regions of the human genome. The functional characterization of these non-coding variants and the identification of their target genes remain challenging. Results In this communication, we explore the potential functional mechanisms of non-coding SNPs by integrating GWAS with the high-resolution chromosome conformation capture (Hi-C) data for breast and prostate cancers. We show that …

Promotion Denied! How Promotion Denial Impacts Turnover For Nonpromoted Employees, Michael Mordechai Hay

LSU Doctoral Dissertations

Research into the effects of promotion decisions has primarily focused on the outcomes for promoted individuals without much concern about employees who were denied a promotion. Additionally, there has been a lack of research about the factors which lead promoted individuals to turnover within the public sector when looking at actual turnover. The present study looked at what effect promotion decisions have on employees regarding their turnover behavior by looking at a longitudinal governmental dataset. In total, 1570 promotion decisions were analyzed, looking at 1570 employees, of which 107 ended up turning over within two years of the initial promotion …

Caloric Restriction In Humans Reveals Immunometabolic Regulators Of Health Span, O. Spadaro, Y. Youm, I. Shchukina, S. Ryu, S. Sidorov, A. Ravussin, K. Nguyen, E. Aladyeva, A. N. Predeus, S. R. Smith, E. Ravussin, C. Galban, M. N. Artyomov, V. D. Dixit

Clinical Research Faculty Publications

The extension of life span driven by 40% caloric restriction (CR) in rodents causes trade-offs in growth, reproduction, and immune defense that make it difficult to identify therapeutically relevant CR-mimetic targets. We report that about 14% CR for 2 years in healthy humans improved thymopoiesis and was correlated with mobilization of intrathymic ectopic lipid. CR-induced transcriptional reprogramming in adipose tissue implicated pathways regulating mitochondrial bioenergetics, anti-inflammatory responses, and longevity. Expression of the gene Pla2g7 encoding platelet activating factor acetyl hydrolase (PLA2G7) is inhibited in humans undergoing CR. Deletion of Pla2g7 in mice showed decreased thymic lipoatrophy, protection against age-related inflammation, …

Social Media: Good Or Evil?, Prosanta Chakrabarty

Faculty Publications

No abstract provided.

Hydrological Seasonality And Nutrient Stoichiometry Control Dissolved Organic Matter Characterization In A Headwater Stream, Siyue Li, Jiachen Luo, Y. Jun Xu, Liuqing Zhang, Chen Ye

Faculty Publications

Dissolved organic matter (DOM) is a diverse and highly complex mixture of organic macromolecules, and thus plays a central role in aquatic ecosystems. However, responses of components and sources of DOM to hydrological processes and trophic levels (nutrient stoichiometric ratios) are poorly understood, particularly in monsoonal headwater streams of Asia that are vulnerable to catchment physical characteristics. In this study, the excitation - emission matrix florescence spectroscopy coupled with parallel factor analysis (EEM-PARAFAC) was used to explore the DOM characters in a headwater stream, where seasonal rainfalls and nutrient levels vary largely. The EEM-PARAFAC modelling identified one autochthonous protein-like fluorescence …

Caregiver Treatment Consumption In An Experimental Treatment Marketplace, Delaney J. Darragh

LSU Master's Theses

Behavioral economics is an approach to understanding consumer behavior by integrating behavioral science with economic principles. Behavioral economics incorporates traditional economic principles with operant learning approaches. There is limited research examining how individuals consume psychological and behavioral treatments. This is especially the case for treatments designed for children. The current study used data from a previously collected sample to explore gender differences in an experimental treatment marketplace (ETM). Experimental treatment marketplaces are generally used to evaluate choices between goods and services (e.g., types of behavior interventions). An ETM was developed to evaluate treatment consumption when levels of evidence differed between …

Connecting The Dots: Transmission Of Stony Coral Tissue Loss Disease From The Marquesas To The Dry Tortugas, Thomas Dobbelaere, Daniel M. Holstein, Erinn M. Muller, Lewis J. Gramer, Lucas Mceachron, Sara D. Williams, Emmanuel Hanert

Faculty Publications

For the last 7 years, Florida's Coral Reef (FCR) has suffered from widespread and severe coral loss caused by stony coral tissue loss disease (SCTLD). First observed off the coast of Miami-Dade county in 2014, the outbreak has since spread throughout the entirety of FCR and some areas of the Caribbean. However, the propagation of the disease through FCR seemed to slow down when it reached the western end of the Marquesas in August 2020. Despite being present about 30 km (similar to 20 miles) from the Dry Tortugas (DRTO), SCTLD was not reported in this area before May 2021. …

The Number Of Tree Species On Earth, Roberto Cazzolla Gatti, Peter B. Reich, Javier G.P. Gamarra, Tom Crowther, Cang Hui, Albert Morera, Jean Francois Bastin, Sergio De-Miguel, Gert Jan Nabuurs, Jens Christian Svenning, Josep M. Serra-Diaz, Cory Merow, Brian Enquist, Maria Kamenetsky, Junho Lee, Jun Zhu, Jinyun Fang, Douglass F. Jacobs, Bryan Pijanowski, Arindam Banerjee, Robert A. Giaquinto, Giorgio Alberti, Angelica Maria Almeyda Zambrano, Esteban Alvarez-Davila, Alejandro Araujo-Murakami, Valerio Avitabile, Gerardo A. Aymard, Radomir Balazy, Chris Baraloto, Jorcely G. Barroso, Meredith L. Bastian, Philippe Birnbaum, Robert Bitariho

Faculty Publications

One of the most fundamental questions in ecology is how many species inhabit the Earth. However, due to massive logistical and financial challenges and taxonomic difficulties connected to the species concept definition, the global numbers of species, including those of important and well-studied life forms such as trees, still remain largely unknown. Here, based on global ground-sourced data, we estimate the total tree species richness at global, continental, and biome levels. Our results indicate that there are ∼73,000 tree species globally, among which ∼9,000 tree species are yet to be discovered. Roughly 40% of undiscovered tree species are in South …

Inhibition Of Biotin Carboxylase By Three Antibacterial Compounds, Matt Craft

LSU Doctoral Dissertations

The rise of antibacterial resistant bacteria is a major problem in the United States of America and around the world. Millions of patients are infected with antimicrobial resistant bacteria each year. Novel antibacterial agents are needed to combat the growing and present crisis. Acetyl-CoA carboxylase (ACC), the multi-subunit complex which catalyses the first committed step in fatty acid synthesis, is a validated target for antibacterial agents. However, there are at present, no commercially available antibiotics that target ACC. Ethyl 4-[[2-chloro-5-(phenylcarbamoyl)phenyl]sulfonylamino]benzoate (SABA1) is a compound that has been shown to have antibacterial properties against Pseudomonas aeruginosa and Escherichia coli. SABA1 inhibits …

Association Between Time In Range And Cancer Mortality Among Patients With Type 2 Diabetes: A Prospective Cohort Study, Yun Shen, Chunfang Wang, Yaxin Wang, Jingyi Lu, Lei Chen, Lei Zhang, Wei Lu, Wei Zhu, Gang Hu, Tian Xia, Jian Zhou

Population and Public Health Science Faculty Publications

Background:Little was known about the association among time in range (TIR), time above range (TAR), time below range (TBR), and cancer mortality among patients with type 2 diabetes. We aimed to investigate the association among TIR, TAR, TBR, and the risk of cancer mortality among patients with type 2 diabetes.Methods:A total of 6225 patients with type 2 diabetes were prospectively recruited in Shanghai, China. TIR was measured with continuous glucose monitoring at baseline and was defined as the average percentage of time in the target glucose range during a 24 h period. Cox proportion hazard regression analysis was used to …

Search Full Text Options Here 2 Of 4 Kmt-2021-Blg-0912lb: A Microlensing Super Earth Around A K-Type Star, Cheongho Han, Ian A. Bond, Jennifer C. Yee, Weicheng Zang, Michael D. Albrow

Faculty Publications

Aims. The light curve of the microlensing event KMT-2021-BLG-0912 exhibits a very short anomaly relative to a single-lens single-source form. We investigate the light curve for the purpose of identifying the origin of the anomaly.

Methods. We model the light curve under various interpretations. From this, we find four solutions, in which three solutions are found under the assumption that the lens is composed of two masses (2L1S models), and the other solution is found under the assumption that the source is comprised of binary stars (1L2S model). The 1L2S model is ruled out based on the contradiction that the …

Tale Of A Non-Interacting Additive In A Lithium-Ion Electrolyte: Effect On Ionic Speciation And Electrochemical Properties, J C. Rushing, C M. Stern, N Elgrishi, D G. Kuroda, J C. Rushing

Faculty Publications

New lithium electrolytes compatible with high energy density cells are critical for lithium metal battery applications, but dendrite formation associated with the use of dilute organic electrolytes complicates their realization. High-concentration electrolytes mitigate some of the issues of the electrolytes but introduce additional problems, such as low conductivity and high cost. Hence, pseudo-concentrated electrolytes, wherein a co-solvent is added to a dilute electrolyte, have been presented as a possible alternative to both dilute and concentrated electrolytes. However, the effect that the co-solvent has on the electrolyte properties at both macroscopic and microscopic levels is unknown. Here, a study of the …

Tale Of A Non-Interacting Additive In A Lithium-Ion Electrolyte: Effect On Ionic Speciation And Electrochemical Properties, J C. Rushing, C M. Stern, N Elgrishi, D G. Kuroda, J C. Rushing

Faculty Publications

New lithium electrolytes compatible with high energy density cells are critical for lithium metal battery applications, but dendrite formation associated with the use of dilute organic electrolytes complicates their realization. High-concentration electrolytes mitigate some of the issues of the electrolytes but introduce additional problems, such as low conductivity and high cost. Hence, pseudo-concentrated electrolytes, wherein a co-solvent is added to a dilute electrolyte, have been presented as a possible alternative to both dilute and concentrated electrolytes. However, the effect that the co-solvent has on the electrolyte properties at both macroscopic and microscopic levels is unknown. Here, a study of the …

Extreme Water Level Simulation And Component Analysis In Delaware Estuary During Hurricane Isabel, Dongxiao Yin, David F. Muñoz, Roham Bakhtyar, Z. George Xue, Hamed Moftakhari, Celso Ferreira, Kyle Mandli

Faculty Publications

Sea level rise and intense hurricane events make the East and Gulf Coasts of the United States increasingly vulnerable to flooding, which necessitates the development of computational models for accurate water level simulation in these areas to safeguard the coastal wellbeing. With this regard, a model framework for water level simulation over coastal transition zone during hurricane events is built in this study. The model takes advantage of the National Water Model’s strength in simulating rainfall–runoff process, and D-Flow Flexible Mesh’s ability to support unstructured grid in hydrodynamic processes simulation with storm surges/tides information from the Advanced CIRCulation model. We …

Mass Removal Efficiencies In Water And Consequences After A River Diversion Into Coastal Wetlands: Second Thoughts, R. Eugene Turner, Erik M. Swenson, James M. Lee, Charles S. Milan

Faculty Publications

Salinity control, nutrient additions, and sediment supply were directly or indirectly the rationale for a $220 million coastal wetland restoration project (Davis Pond River Diversion) that began in 2002. We sampled Mississippi River water going in and out of the receiving basin from 1999 to 2018 to understand why wetland loss increased after it began. There was a reduction in inorganic sediments, nitrogen (N), and phosphorus (P) concentrations within the ponding area of 77%, 39% and 34%, respectively, which is similar to that in other wetlands. But the average sediment accumulation of 0.6 mm year(-1) inadequately balances the present-day 5.6 …

Alluvial Connectivity In Multi‐Channel Networks In Rivers And Estuaries, Willem Sonke, Maarten G. Kleinhans, Bettina Speckmann, Wout M. Dijk, Matthew Hiatt

Faculty Publications

No abstract provided.

Phytoplankton Dynamics In Louisiana Estuaries: Building A Baseline To Understand Current And Future Change, Julia A. Sweet, Sibel Bargu, Wendy L. Morrison, Michael Parsons, Mrunmayee G. Pathare, Brian J. Roberts, Thomas M. Soniat, Beth A. Stauffer

Faculty Publications

Louisiana estuaries are important habitats in the northern Gulf of Mexico, a region undergoing significant and sustained human- and climate-driven changes. This paper synthesizes data collected over multiple years from four Louisiana estuaries – Breton Sound, Terrebonne Bay, the Atchafalaya River Delta Estuary, and Vermilion Bay – to characterize trends in phytoplankton biomass, community composition, and the environmental factors influencing them. Results highlight similarities in timing and composition of maximum chlorophyll, with salinity variability often explaining biomass trends. Distinct drivers for biomass versus community structure were observed in all four estuarine systems. Systems shared a lack of significant correlation between …

A Bayesian Phase I/Ii Biomarker-Based Design For Identifying Subgroup-Specific Optimal Dose For Immunotherapy, Beibei Guo, Yong Zang

Faculty Publications

Immunotherapy is an innovative treatment that enlists the patient's immune system to battle tumors. The optimal dose for treating patients with an immunotherapeutic agent may differ according to their biomarker status. In this article, we propose a biomarker-based phase I/II dose-finding design for identifying subgroup-specific optimal dose for immunotherapy (BSOI) that jointly models the immune response, toxicity, and efficacy outcomes. We propose parsimonious yet flexible models to borrow information across different types of outcomes and subgroups. We quantify the desirability of the dose using a utility function and adopt a two-stage dose-finding algorithm to find the optimal dose for each …

Singing Strategies Are Linked To Perch Use On Foraging Territories In Heart-Nosed Bats, Grace C. Smarsh, Ashley M. Long, Michael Smotherman

Faculty Publications

Acoustic communication allows animals to coordinate and optimize resource utilization in space. Cardioderma cor, the heart-nosed bat, is one of the few species of bats known to sing during nighttime foraging. Previous research found that heart-nosed bats react aggressively to song playback, supporting the territorial defense hypothesis of singing in this species. We further investigated the territorial defense hypothesis from an ecological standpoint, which predicts that singing should be associated with exclusive areas containing a resource, by tracking 14 individuals nightly during the dry seasons in Tanzania. We quantified the singing behavior of individuals at all perches used throughout the …

A Comparative Review Of Peridynamics And Phase-Field Models For Engineering Fracture Mechanics, Patrick Diehl, Robert Lipton, Thomas Wick, Mayank Tyagi

Faculty Publications

Computational modeling of the initiation and propagation of complex fracture is central to the discipline of engineering fracture mechanics. This review focuses on two promising approaches: phase-field (PF) and peridynamic (PD) models applied to this class of problems. The basic concepts consisting of constitutive models, failure criteria, discretization schemes, and numerical analysis are briefly summarized for both models. Validation against experimental data is essential for all computational methods to demonstrate predictive accuracy. To that end, the Sandia Fracture Challenge and similar experimental data sets where both models could be benchmarked against are showcased. Emphasis is made to converge on common …

Strict Lyapunov Functions And Feedback Controls For Sir Models With Quarantine And Vaccination, Hiroshi Ito, Michael Malisoff, Frederic Mazenc

Faculty Publications

We provide a new global strict Lyapunov function construction for a susceptible, infected, and recovered (or SIR) disease dynamics that includes quarantine of infected individuals and mass vaccination. We use the Lyapunov function to design feedback controls to asymptotically stabilize a desired endemic equilibrium, and to prove input-to-state stability for the dynamics with a suitable restriction on the disturbances. Our simulations illustrate the potential of our feedback controls to reduce peak levels of infected individuals.

Intact, Commercial Lithium-Polymer Batteries: Spatially Resolved Grating-Based Interferometry Imaging, Bragg Edge Imaging, And Neutron Diffraction, A J. Brooks, D S. Hussey, K Ham, D L. Jacobson, A J. Brooks, N Kardjilov, L G. Butler

Faculty Publications

We survey several neutron imaging and diffraction methods for non-destructive testing and evaluation of intact, commercial lithium-ion batteries. Specifically, far-field interferometry was explored as an option to probe a wide range of autocorrelation lengths within the batteries via neutron imaging. The dark-field interferometry images change remarkably from fresh to worn batteries, and from charged to discharged batteries. When attempting to search for visual evidence of battery degradation, neutron Talbot-Lau grating interferometry exposed battery layering and particle scattering through dark-field imaging. Bragg edge imaging also reveals battery wear and state of charge. Neutron diffraction observed chemical changes between fresh and worn, …

Predator-Pest Dynamics Of Arthropods Residing In Louisiana Soybean Agroecosystems, Scott T. Lee, Chaoyang Li, Jeffrey A. Davis

Faculty Publications

Over the past two decades, management practices within Louisiana soybean production have shifted. Successful application of an integrated pest management (IPM) strategy requires an understanding of how these changes have affected predator-pest dynamics. Surveys monitoring foliage-foraging arthropod populations in soybean took place across six locations within Louisiana over six years (2012–2014 and 2015–2018). Temporal associations of pest groups, defoliating and piercing-sucking, and predator groups relating to soybean phenology were observed. Additionally, soybean maturity groups (III, IV, and V) were also evaluated to delineate potential differences. Results indicated higher abundances of piercing-sucking pests compared to defoliating pests across both datasets (2012–2014 …

Optimizing Chemical Control For Diatraea Saccharalis (Lepidoptera: Crambidae) In Sugarcane, B. E. Wilson, L. D. Salgado, J. M. Villegas

Faculty Publications

The sugarcane borer, Diatraea saccharalis (Lepidoptera: Crambidae), is the primary pest of sugarcane, Saccharum spp., in much of North and South America. Control of D. saccharalis can be obtained through judicious application of insecticides, but more research is needed to optimize chemical control strategies. A series of field trials evaluated the duration of protection and influence of application water volume on D. saccharalis control in Louisiana sugarcane from 2018 to 2020. Results across trials demonstrated superior control was achieved with chlorantraniliprole over novaluron and tebufenozide. Analysis of insecticide concentrations present in leaf sheath tissue of the target internode suggests chlorantraniliprole …

Nudging Away From Plastic Bags With Charitable Donations, Jerrod Penn, Sapana Bastola, Wuyang Hu

Faculty Publications

To respond to the environmental problems posed by disposable plastic bags, several mechanisms exist, such as bag taxes and bans, but such policies are infeasible in several U.S. states and municipalities. This study uses a social quasi-experiment to examine the effect of a voluntary token-donation program, which reduces disposable plastic bag use by providing a small charitable donation incentive. We find that the token-donation program reduces the probability of disposable bag use by 11.4–12.9 percentage points, representing about 30%–34% decrease in bag use. Our results demonstrate effective mechanisms to reduce plastic bags exist without government-mandated policy.