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The Influence Of Stochasticity, Landscape Structure And Species Traits On Abundant–Centre Relationships, Tad A. Dallas, Luca Santini

Faculty Publications

© 2020 The Authors. Ecography published by John Wiley & Sons Ltd on behalf of Nordic Society Oikos Species have been commonly hypothesized to have high population densities in geographic areas which correspond to either the centre of the species geographic range or climatic niche (abundant–centre hypothesis). However, there is mixed empirical support for this relationship, and little theoretical underpinning. We simulate a species spreading across a set of replicated artificial landscapes to examine the expected level of support for abundant–centre relationships in geographic and niche space. Species niche constraints were modeled as a single axis which was related directly …

Identification Of Pathways Associated With Placental Adaptation To Maternal Nutrient Restriction In Sheep, Ashley K. Edwards, Kathrin A. Dunlap, Thomas E. Spencer, M. Carey Satterfield

Faculty Publications

Maternal nutrient restriction impairs placental growth and development, but available evidence suggests that adaptive mechanisms exist, in a subset of nutrient restricted (NR) ewes, that support normal fetal growth and do not result in intrauterine growth restriction (IUGR). This study utilized Affymetrix GeneChip Bovine and Ovine Genome 1.0 ST Arrays to identify novel placental genes associated with differential fetal growth rates within NR ewes. Singleton pregnancies were generated by embryo transfer and, beginning on Day 35 of pregnancy, ewes received either a 100% NRC (control-fed group; n = 7) or 50% NRC (NR group; n = 24) diet until necropsy …

Synergisms In Science: Climate Change And Integrated Pest Management Through The Lens Of Communication-2019 Student Debates, Jocelyn R. Holt, Lina Bernaola, Kadie E. Britt, Chirs Mccullough, Morgan Roth, Jennie Wagner, Max Ragozzino, Leslie Aviles, Zhilin Li, Forest Huval, Manoj Pandey, Benjamin W. Lee, Megan Asche, Abigail Hayes, Abigail Cohen, Adrian Marshall, Hannah E. Quellhorst, Rachel V. Wilkins, Valerie Nguyen, Jacqueline Maille, Rachel K. Skinner, John J. Ternest, Sarah Anderson, Scott W. Gula, Kayleigh Hauri, Julius Eason, Megan Mulcahy, Scott Lee, James Michael Villegas, Patricia Shorter

Faculty Publications

Every year, the Student Debates Subcommittee (SDS) of the Student Affairs Committee (SAC) for the annual Entomological Society of America (ESA) meeting organizes the Student Debates. This year, the SAC selected topics based on their synergistic effect or ability to ignite exponential positive change when addressed as a whole. For the 2019 Student Debates, the SAC SDS identified these topic areas for teams to debate and unbiased introduction speakers to address: 1) how to better communicate science to engage the public, particularly in the area of integrated pest management (IPM), 2) the influential impacts of climate change on agriculturally and …

Multiple Decrement Life Tables Of Cephus Cinctus Norton (Hymenoptera: Cephidae) Across A Set Of Barley Cultivars: The Importance Of Plant Defense Versus Cannibalism, Buddhi B. Achhami, Robert K.D. Peterson, Jamie D. Sherman, Gadi V.P. Reddy, David K. Weaver

Faculty Publications

Accurately estimating cause-specific mortality for immature insect herbivores is usually difficult. The insects are exposed to abiotic and biotic mortality factors, causing cadavers to simply disappear before cause of mortality can be recorded. Also, insect herbivores are often highly mobile on hosts, making it difficult to follow patterns for individuals through time. In contrast, the wheat stem sawfly, Cephus cinctus Norton, spends its entire egg, larval, and pupal period inside a host stem. Therefore, with periodic sampling stage-specific causes of mortality can be ascertained. Consequently, we examined C. cinctus mortality in eight barley, Hordeum vulgare L., cultivars in two locations …

Antixenosis, Antibiosis, And Potential Yield Compensatory Response In Barley Cultivars Exposed To Wheat Stem Sawfly (Hymenoptera: Cephidae) Under Field Conditions, Buddhi B. Achhami, Gadi V.P. Reddy, Jamie D. Sherman, Robert K.D. Peterson, David K. Weaver

Faculty Publications

Wheat stem sawfly, Cephus cinctus Norton, is an economically serious pest of cereals grown in North America. Barley cultivars were previously planted as resistant crops in rotations to manage C. cinctus, but due to increasing levels of injury to this crop, this is no longer a valid management tactic in Montana. Therefore, we aimed to understand antixenosis (behavioral preference), antibiosis (mortality), and potential yield compensation (increased productivity in response to stem injuries) in barley exposed to C. cinctus. We examined these traits in eight barley cultivars. Antixenosis was assessed by counting number of eggs per stem and antibiosis was assessed …

Unpacking The Decline In Food Waste Measured In Chinese Households From 1991 To 2009, Danyi Qi, John W. Apolzan, Ran Li, Brian E. Roe

Faculty Publications

© 2020 Elsevier B.V. Food waste reduction is an explicit goal for many countries, yet a paucity of high-quality primary measurements of food waste are available to inform policy. We analyze repeated physical measurements of discarded food from more than 37,000 households enrolled in the China Health and Nutrition Survey (CHNS) from 1991 to 2009 and describe relevant food waste patterns and trends within households over a period of dramatic change. Over a period in which average real household incomes tripled, food discarded per person declined by about 20% on a quantity basis and by about 40% on a Calorie …

Electronic-Cigarette Vehicles And Flavoring Affect Lung Function And Immune Responses In A Murine Model, Brittany N. Szafran, Rakeysha Pinkston, Zakia Perveen, Matthew K. Ross, Timothy Morgan, Daniel B. Paulsen, Arthur L. Penn, Barbara L. F. Kaplan, Alexandra Noel

Faculty Publications

The use of electronic nicotine delivery systems (ENDS), also known as electronic-cigarettes (e-cigs), has raised serious public health concerns, especially in light of the 2019 outbreak of e-cig or vaping product use-associated acute lung injury (EVALI). While these cases have mostly been linked to ENDS that contain vitamin E acetate, there is limited research that has focused on the chronic pulmonary effects of the delivery vehicles (i.e., without nicotine and flavoring). Thus, we investigated lung function and immune responses in a mouse model following exposure to the nearly ubiquitous e-cig delivery vehicles, vegetable glycerin (VG) and propylene glycol (PG), used …

Formation Of Tubular Carbonates Within The Seabed Of The Northern South China Sea, Yuedong Sun, Jörn Peckmann, Yu Hu, Xudong Wang, Shanggui Gong, Yongbo Peng, Duofu Chen, Dong Feng

Faculty Publications

© 2020 by the authors. Licensee MDPI, Basel, Switzerland. A remarkable exposure of tubular authigenic carbonates was found on the seafloor in the Dongsha area of the South China Sea (SCS). The tubular carbonates, around 2–3 cm in diameter and usually less than 10 cm in length, represent broken fragments of once-larger pipes that now protrude from muddy sediments. The morphology, carbon and oxygen stable isotope compositions, and trace and rare earth element contents of the carbonates were analyzed to decipher the mode of carbonate formation. The tubular carbonates exhibit a dark brown coating of iron and manganese hydrous oxides, …

Obesity, Noncommunicable Diseases, And Covid-19: A Perfect Storm, Peter T. Katzmarzyk, J. Michael Salbaum, Steven B. Heymsfield

Division of Basic Science Faculty Publications

No abstract provided.

Assessment Of Energy Expenditure: Are Calories Measured Differently For Different Diets?, Guillermo Sanchez-Delgado, Eric Ravussin

Clinical Research Faculty Publications

Purpose of review The prevalence and burden of obesity has reached alarming levels. The assessment of human energy expenditure enables the identification of obesity-prone and obesity-resistant individuals and helps to explain the short and long-term success of weight loss treatments. In this review, we describe the state-of-the-art methods used in the assessment of human energy expenditure and the impact of dietary intake on the interpretation of the data. Recent findings The reference techniques to assess energy expenditure in humans have not significantly changed during the last century. Today, indirect calorimetry, either using a metabolic chamber or a metabolic cart, is …

Integrative And Quantitative Bioenergetics: Design Of A Study To Assess The Impact Of The Gut Microbiome On Host Energy Balance, Karen D. Corbin, Rosa Krajmalnik-Brown, Elvis A. Carnero, Christopher Bock, Rita Emerson, Bruce E. Rittmann, Andrew K. Marcus, Taylor Davis, Blake Dirks, Zehra Esra Ilhan, Catherine Champagne, Steven R. Smith

Population and Public Health Science Faculty Publications

The literature is replete with clinical studies that characterize the structure, diversity, and function of the gut microbiome and correlate the results to different disease states, including obesity. Whether the microbiome has a direct impact on obesity has not been established. To address this gap, we asked whether the gut microbiome and its bioenergetics quantitatively change host energy balance. This paper describes the design of a randomized crossover clinical trial that combines outpatient feeding with precisely controlled metabolic phenotyping in an inpatient metabolic ward. The target population was healthy, weight-stable individuals, age 18–45 and with a body mass index ≤30 …

Sgcg Rs679482 Associates With Weight Loss Success In Response To An Intensively Supervised Outpatient Program, Majid Nikpay, Paulina Lau, Sébastien Soubeyrand, Katey L. Whytock, Kaitlyn Beehler, Chantal Pileggi, Sujoy Ghosh, Mary Ellen Harper, Robert Dent, Ruth Mcpherson

Division of Basic Science Faculty Publications

Weight loss in response to energy restriction is highly vari-able, and identification of genetic contributors can provide insights into underlying biology. Leveraging 1000 Genomes imputed genotypes, we carried out genome-wide association study (GWAS) analysis in 551 unrelated obese subjects of European ancestry who participated in an intensively supervised weight loss program with replication of promising signals in an independent sample of 1,331 obese subjects who completed the program at a later date. By single nucleotide polymorphism–based and sib-pair analy-sis, we show that that weight loss is a heritable trait, with estimated heritability (h2 = 0.49) within the range reported for …

Obesity, The Most Common Comorbidity In Sars-Cov-2: Is Leptin The Link?, Candida J. Rebello, John P. Kirwan, Frank L. Greenway

Division of Basic Science Faculty Publications

Overweight and obesity are major risk factors for diabetes, cardiovascular disease, and lung disease. These diseases are the most commonly reported health conditions that predispose individuals with SARS-CoV-2 infection to require hospitalization including intensive care unit admissions. The innate immune response is the host’s first line of defense against a human coronavirus infection. However, most coronaviruses are armed with one strategy or another to overcome host antiviral defense, and the pathogenicity of the virus is related to its capacity to suppress host immunity. The multifaceted nature of obesity including its effects on immunity can fundamentally alter the pathogenesis of acute …

Effects Of Gastric Bypass Surgery On Expression Of Glucose Transporters And Fibrotic Biomarkers In Kidney Of Diabetic Fatty Rats, Roman Vangoitsenhoven, Anny Mulya, J. David Mosinski, Stacy A. Brethauer, Philip R. Schauer, John P. Kirwan, Ali Aminian

Division of Basic Science Faculty Publications

Background: Diabetic nephropathy is the leading cause of chronic kidney disease. Observational studies suggest Roux-en-Y gastric bypass (RYGB) reduces progression of diabetic nephropathy. Objectives: To unravel the mechanisms by which RYGB is beneficial and protective for diabetic nephropathy. Setting: Academic laboratories. Methods: Forty-eight Zucker diabetic fatty rats were randomized to RYGB, sham surgery (SHAM), or pair-fed (PF) groups. An oral glucose tolerance test was performed at 25 days post intervention and kidneys were harvested at 30 days. Primary outcome measures included expression of key genes and proteins in the glucose transport, oxidative stress, inflammation, and fibrosis pathways. Results: Thirty days …

Behavioral Strategies During Incubation Influence Nest And Female Survival Of Wild Turkeys, Ashley K. Lohr, James A. Martin, Gregory T. Wann, Bradley S. Cohen, Bret A. Collier, Michael J. Chamberlain

Faculty Publications

Females must balance physiological and behavioral demands of producing offspring with associated expenditures, such as resource acquisition and predator avoidance. Nest success is an important parameter underlying avian population dynamics. Galliforms are particularly susceptible to low nest success due to exposure of ground nests to multiple predator guilds, lengthy incubation periods, and substantive reliance on crypsis for survival. Hence, it is plausible that nesting individuals prioritize productivity and survival differently, resulting in a gradient of reproductive strategies. Fine-scale movement patterns during incubation are not well documented in ground-nesting birds, and the influence of reproductive movements on survival is largely unknown. …

Phyr: Anrpackage For Phylogenetic Species-Distribution Modelling In Ecological Communities, Daijiang Li, Russell Dinnage, Lucas A. Nell, Matthew R. Helmus, Anthony Ives

Faculty Publications

Model-based approaches are increasingly popular in ecological studies. A good example of this trend is the use of joint species distribution models to ask questions about ecological communities. However, most current applications of model-based methods do not include phylogenies despite the well-known importance of phylogenetic relationships in shaping species distributions and community composition. In part, this is due to a lack of accessible tools allowing ecologists to fit phylogenetic species distribution models easily. To fill this gap, therpackagephyr(pronounced fire) implements a suite of metrics, comparative methods and mixed models that use phylogenies to understand and predict community composition and other …

Process Controls Of The Live Root Zone And Carbon Sequestration Capacity Of The Sundarbans Mangrove Forest, Bangladesh, Edwin J. Bomer, Carol A. Wilson, Tracy Elsey-Quirk

Faculty Publications

The conservation of coastal wetland ecosystems, like mangrove forests and salt marshes, represents a critical strategy for mitigating atmospheric emissions and climate change in the 21st century. Yet the existence of these environments is threatened by human-induced disturbances, namely deforestation and accelerated sea-level rise. Coastal systems maintain surface elevation in response to sea-level rise through a combination of physical and biological processes both above and below the ground surface. The quantification and relative contribution of belowground process controls (e.g., seasonal water content, organic matter decomposition) on surface elevation change is largely unexplored but crucial for informing coastal ecosystem sustainability. To …

A Small-Volume, High-Throughput Approach For Surface Tension And Viscosity Measurements Of Liquid Fuels, Wanjun Dang, Wei Zhao, Ingmar Schoegl, Shyam Menon

Faculty Publications

An ongoing effort looking at bioblendstocks to function as drop-in replacements or blending components for gasoline has identified a large number of candidate fuels. This work documents an approach for rapid screening of candidate fuels using relatively small sample sizes (O(μ l)) that targets two key physical properties of liquid fuels - surface tension and viscosity. The approach utilizes shape oscillation dynamics of single droplets generated by a piezo-electric device and their decay over time. Strobed imaging of the oscillation process is used along with image processing, edge detection, and data analysis to capture the decay of the oscillation over …

Effects Of Coupled Consolidation And Overwash Processes On A Low-Lying Headland System, Brian D. Harris, Cody Johnson, Navid H. Jafari, Qin Chen, Celalettin E. Ozdemir

Faculty Publications

Coastal barrier islands serve as the first line of defense against storm-induced hazards and coastal erosion. Due to sea-level rise and more frequently occurring storms, barrier island restoration and rehabilitation have become more important for coastal protection. The current-state-of-the practice for simulation of barrier island restoration design mostly overlooks consolidation as one of the governing processes. However, low-lying barrier islands, especially those built on loose deltaic or estuarine deposits, may further lose elevation due to consolidation and become more vulnerable to erosion. This study investigates the impacts of consolidation without overwash, overwash without consolidation, and coupled consolidation and overwash in …

Fabrication And Application Of Flexible Sensors, Tallis Huther Da Costa

LSU Doctoral Dissertations

A transfer printing method was developed to transfer carbon nanotubes (CNTs) from polyethylene terephthalate (PET) film to poly(dimethyl siloxane) (PDMS) polymer. Carbon nanotubes are composed of carbon atoms arranged in a honeycomb lattice structure, which are electrically conducting. When embedded in a nonconducting polymer, carbon nanotubes impart electrical conductivity to the nanocomposite, thus forming a nanocomposite that has potential applications in highly sensitive strain and pressure sensors. Several printing methods have been studied to deposit carbon nanotubes onto PDMS, including inkjet printing. Inkjet printing is a desirable deposition method since it is low-cost, simple, and allows the processing of aqueous-based …

Hydrodynamics, Sediment Transport, And Water Quality Of Two Contrasting Dredge Pits On The Louisiana Shelf, Robert Bales

LSU Master's Theses

Sediment is needed for coastal restoration in Louisiana and is often excavated offshore from both mud-capped and sandy dredge pits. The mined sand from mud-capped pits, like Sandy Point which is west of modern Mississippi Delta of Louisiana, was originally from a paleo river channel and later covered by mud from modern coastal processes. Sandy pits, like Caminada pit in eastern Ship Shoal on Louisiana shelf, generally experience higher energy conditions. To better understand the post-dredging effects on hydrodynamics, sediment transport, and water quality, two tripods were deployed at Caminada and Sandy Point pits in summer 2018 and 2019, respectively, …

Louisiana Southern Flounder: Commercial And Recreational Trends, David Russell Smith

LSU Master's Theses

Southern Flounder (Paralichthys lethostigma) is a coastal flatfish species that supports recreational and commercial fisheries throughout Louisiana. The recreational and commercial sectors of the Southern Flounder fishery in Louisiana both lack current information that profiles the fishery’s ability to meet stakeholder interest. This project characterized the Louisiana Southern Flounder fishery through an evaluation of fishery-dependent data and a survey of coastal Louisiana anglers.

Fishery-dependent data was gathered to characterize the recreational and commercial Southern Flounder fisheries in Louisiana. This study had three objectives for this evaluation: 1) modeling landings data to evaluate any trends, 2) examine the seasonality of landings, …

Protein Discrimination Using A Fluorescence-Based Sensor Array Of Thiacarbocyanine-Gumbos, Rocio L. Perez, Mingyan Cong, Stephanie R. Vaughan, Caitlan E. Ayala, Waduge Indika S. Galpothdeniya, John K. Mathaga, Isiah M. Warner

Faculty Publications

Sensitive and selective detection of proteins from complex samples has gained substantial interest within the scientific community. Early and precise detection of key proteins plays an important role in potential clinical diagnosis, treatment of different diseases, and proteomic research. In the study reported here, six different compounds belonging to a group of uniform materials based on organic salts (GUMBOS) have been synthesized using three thiacarbocyanine (TC) dyes and employed as fluorescent sensors. Fluorescence properties of micro- and nanoaggregates of these TC-based GUMBOS formed in phosphate buffer solutions are studied in the absence and presence of seven proteins. Fluorescence response patterns …

The Effects Of Radical Containing Combustion Derived Particulate Matter In Adult Mouse Respiratory System, Jeffrey Harding

LSU Doctoral Dissertations

Epidemiological data associates high levels of combustion-derived particulate matter (PM) with deleterious respiratory outcomes, but the mechanism underlying those outcomes remains elusive. It has been acknowledged by the World Health Organization that PM exposure contributes to more than 4.2 million all-cause mortalities worldwide each year. Current literature demonstrates that PM exacerbates respiratory diseases, impairs lung function, results in chronic respiratory illnesses, and is associated with increased mortality. The proposed mechanisms revolve around oxidative stress and inflammation promoting pulmonary physiological remodeling. Our data demonstrate that environmentally persistent free radicals (EPFRs) stabilized on the surface of PM are capable of inducing oxidative …

The Roles Of Host Species, Geographic Scale And Environmental Stressors In Shaping The Composition Of Coral Microbiomes, Alicia Marie Riegel Parker

LSU Doctoral Dissertations

Reef-building corals are long-lived and may take many centuries to adapt, making them especially susceptible to climate change. However, corals host microbial symbionts that can change quickly, potentially speeding acclimation. My dissertation aimed to determine the degree of coevolution and flexibility between corals and their microbiomes among hosts, across space, and in response to stress.

Microbial communities are usually surveyed by sequencing the 16S rRNA gene, however the PCR primers used also amplify coral DNA, thereby limiting prokaryotic read coverage. To mitigate this contamination, I designed a peptide nucleic acid clamp that increased the recovery of bacterial reads by 2-11x …

Exploring The Fmn Binding Site In The Mitochondrial Outer Membrane Protein Mitoneet, Homyra Tasnim, Aaron P. Landry, Chelsey R. Fontenot, Huangen Ding

Faculty Publications

© 2020 Elsevier Inc. MitoNEET is a mitochondrial outer membrane protein that hosts a redox active [2Fe-2S] cluster in the C-terminal cytosolic domain. Increasing evidence has shown that mitoNEET has an essential role in regulating energy metabolism in human cells. Previously, we reported that the [2Fe-2S] clusters in mitoNEET can be reduced by the reduced flavin mononucleotide (FMNH2) and oxidized by oxygen or ubiquinone-2, suggesting that mitoNEET may act as a novel redox enzyme catalyzing electron transfer from FMNH2 to oxygen or ubiquinone. Here, we explore the FMN binding site in mitoNEET by using FMN analogs and find that lumiflavin, …

Influence Of External Nacl Salt On Membrane Rigidity Of Neutral Dopc Vesicles, Judith U. De Mel, Sudipta Gupta, Rasangi M. Perera, Ly Ngo, Piotr Zolnierczuk, Markus Bleuel, Sai Venkatesh Pingali, Gerald J. Schneider

Faculty Publications

Copyright © 2020 American Chemical Society. Sodium chloride (NaCl) is a very common molecule in biotic and abiotic aqueous environments. In both cases, variation of ionic strength is inevitable. In addition to the osmotic variation posed by such perturbations, the question of whether the interactions of monovalent ions Na+ and Cl-, especially with the neutral head groups of phospholipid membranes are impactful enough to change the membrane rigidity, is still not entirely understood. We investigated the dynamics of 1,2-di-(octadecenoyl)-sn-glycero-3-phosphocholine (DOPC) vesicles with zwitterionic neutral head groups in the fluid phase with increasing external salt concentration. At higher salt concentrations, we …

Using Stable Isotopes To Disentangle Marine Sedimentary Signals In Reactive Silicon Pools, Rebecca A. Pickering, Lucie Cassarino, Katharine R. Hendry, Xiangli L. Wang, Kanchan Maiti, Jeffrey W. Krause

Faculty Publications

Many studies use sedimentary biogenic silica (bSiO2) stable isotopes (e.g., δ³⁰Si) as paleoproxies but neglect signals from other sedimentary reactive SiO2 phases. We quantified δ³⁰Si for multiple reactive Si pools in coastal river-plume sediments, revealing up to −5‰ difference between acid-leachable and alkaline-digestible amorphous SiO2. Thus, previous studies have missed valuable information on early diagenetic products and, in cases where sediments were not cleaned, potentially biased bSiO2 δ³⁰Si values. Acid-leachable δ³⁰Si, that is, from authigenic products, are the result of either multistep fractionation from a bSiO2 source or an ~2‰ fractionation (consistent …

Do Ground Layer Microhabitats In Old-Growth Pine Savanna Influence Recruitment Of Longleaf Pine?, Matthew Blanchard

LSU Master's Theses

Savanna tree populations typically share two demographic characteristics, high mortality of juvenile stages and low mortality of established trees. Juvenile savanna tree species escape demographic bottlenecks when they reach a safe size and annual mortality becomes low. Longleaf pine (Pinus palustris Mill.) is the dominant tree species in pine savannas of the southeastern United States. The seeds and juvenile seedlings experience bottlenecks to recruitment to a safe size, the grass stage. Low intensity, frequent savanna fires facilitate establishment of seedlings, but also kill juvenile seedlings that have not grown sufficient above ground biomass. We hypothesized that juvenile seedlings escape the …

Development Of Artificial Intelligence Approach To Nowcasting And Forecasting Vibrio Prevalence In Coastal Waters, Peyman Hosseinzadeh Namadi

LSU Doctoral Dissertations

Vibrio parahaemolyticus (V.p) is an epidemiologically significant pathogen that poses high risks to the human health and shellfish industry, calling for predictive models for management interventions. This study presents an Artificial Intelligence(AI)-based approach to predicting and reducing the risks. The AI-based approach involves the identification of environmental indicators and their optimum variation ranges favoring V.p prevalence, the development of nowcasting and forecasting models for predicting V.p prevalence, and the creation of remote sensing algorithms for mapping concentrations of V.p and its environmental indicators by synergistically combining the Deep Neural Network (DNN) modeling technique, Genetic Programming (GP) method, R …