Digital Commons Network^™

Continental Divide(S), Carmela Lanza

Comparative Woman

No abstract provided.

Grand Mothers, Lizzie Nova

Comparative Woman

No abstract provided.

Intraguild Predation: Interactions Between Predators, Pathogens, And Their Shared Resources In Crop Pest Communities, Andrew Jason Flick

LSU Doctoral Dissertations

Crop pest management requires an understanding of the complex interactions among pest species that potentially damage crop yield and species that may be crucial for controlling pest species outbreaks. For example, predators, parasitoids, and pathogens are constantly interacting via their shared prey or hosts. Predators may prefer infected prey, which can be easier to catch; however, infected prey may be less nutritious or even lethal for predators. These interactions then dictate the short-term dynamics of host and pathogen as well as between prey and predator. "How these dynamics change as the species in the system change either empirically or theoretically?" …

Phenotypic And Transcriptomic Characterization Of Colonial Phase Variation In The Cholera Pathogen Reveals A Novel Smooth Biofilm-Defective Form, Bliss Nicole Lambert

LSU Doctoral Dissertations

Biofilm formation, through the production of Vibrio polysaccharide (VPS), greatly enhances the environmental fitness and pathogenic success of Vibrio cholerae. As a result of phase variation, V. cholerae can switch from a smooth form to rugose, whose cells produce excess VPS, resulting in highly structured biofilms and greater resistance to stress. To further characterize the reversible process of phase variation, we isolated three colonial lineages. Each lineage began with a smooth parent, N16961, and contained a rugose variant derived from the parent, N16961R, as well as a smooth revertant of the rugose, N16961SD. We found clear phenotypic and transcriptomic …

Physicochemical And Ecotoxicological Assessment Of Biochar For Environmental Application, Maria Guillermina Cantou

LSU Doctoral Dissertations

Multiple benefits of biochar conversion and utilization, including soil carbon sequestration and environmental remediation, have been proposed by researchers. Biochar may be produced from a wide array of feedstocks and pyrolytic process conditions. This influences the final biochar composition, which includes the presence of potential pollutants that could ultimately result in detrimental environmental impacts. The major purpose of this research was to improve our understanding of potential unintended effects of biochar addition to the environment either as a potential source of toxicity towards organisms or as a material influencing availabilities of other soil contaminants. Biochars were produced from ten different …

A Poetics Of Temperance: Gender, Genre, And Meaning-Making In Early Modern England, Cristina Maria Rosell

LSU Doctoral Dissertations

For several hundred years, the scholarly discussion of temperance was dominated by the legacy of classical models. This dissertation, titled A Poetics of Temperance: Gender, Genre, and Meaning-Making in Early Modern England, develops said discussion in a new way by forging a language about ethics and aesthetics into a poetics of temperance. The term poiesis derives from Greek and signifies “to make, create, produce” (OED). Accordingly, Aristotle uses the Greek poietes, “from which our word ‘poet’ derives,” to denote a “maker” (Murray xxxii). In brief, this project understands the role of women in emergent genres as …

Pixel-Level Reconstruction And Classification For Noisy Handwritten Bangla Characters, Manohar Karki, Qun Liu, Robert Dibiano, Saikat Basu, Supratik Mukhopadhyay

Faculty Publications

Classification techniques for images of handwritten characters are susceptible to noise. Quadtrees can be an efficient representation for learning from sparse features. In this paper, we improve the effectiveness of probabilistic quadtrees by using a pixel level classifier to extract the character pixels and remove noise from handwritten character images. The pixel level denoiser (a deep belief network) uses the map responses obtained from a pretrained CNN as features for reconstructing the characters eliminating noise. We experimentally demonstrate the effectiveness of our approach by reconstructing and classifying a noisy version of handwritten Bangla Numeral and Basic Character datasets.

Homogenization Of Species Composition And Species Association Networks Are Decoupled, Daijiang Li, Timothée Poisot, Donald M. Waller, Benjamin Baiser

Faculty Publications

© 2018 John Wiley & Sons Ltd Aim: Ecological communities are composed of both species and the biotic relationships (interactions or spatial associations) among them. Biotic homogenization in species composition (i.e., increased site-to-site similarity) is recognized as a common consequence of global change, but less is known about how the similarity of species relationships changes over space and time. Does homogenization of species composition lead to homogenization of species relationships or are the dynamics of species relationships decoupled from changes in species composition?. Location: Wisconsin, USA. Time period: 1950–2012. Major taxa studied: Vascular plants. Methods: We used long-term resurvey data …

Neural And Behavioural Correlates Of Repeated Social Defeat, Julie M. Butler, Sarah M. Whitlow, David A. Roberts, Karen P. Maruska

Faculty Publications

© 2018 The Author(s). Dominance hierarchies are common across the animal kingdom and have important consequences for reproduction and survival. Animals of lower social status cope with repeated social defeat using proactive and reactive behaviours. However, there remains a paucity of information on how an individual's coping behaviours changes over time or what neural mechanisms are involved. We used a resident-intruder paradigm in the African cichlid fish Astatotilapia burtoni to investigate the neural correlates of these two opposing behaviour groups. Fish initially used both proactive and reactive behaviours, but had a dramatic increase in use of proactive behaviours during the …

Gauging Support For Macroecological Patterns In Helminth Parasites, Tad A. Dallas, A. Alonso Aguirre, Sarah Budischak, Colin Carlson, Vanessa Ezenwa, Barbara Han, Shan Huang, Patrick R. Stephens

Faculty Publications

© 2018 John Wiley & Sons Ltd Aim: To explore spatial patterns of helminth parasite diversity, and to investigate three main macroecological patterns – (a) latitude–diversity relationships, (b) positive scaling between parasite and host diversity, and (c) species–area relationships – using a largely underutilized global database of helminth parasite occurrence records. Location: Global. Methods: We examined the London Natural History Museum’s collection of helminth parasite occurrence records, consisting of over 18,000 unique host species and 27,000 unique helminth parasite species distributed across over 350 distinct terrestrial and aquatic localities. Results: We find support for latitudinal gradients in parasite diversity and …

Limitations In Predicting The Space Radiation Health Risk For Exploration Astronauts, Jeffery C. Chancellor, Rebecca S. Blue, Keith A. Cengel, Serena M. Auñón-Chancellor, Kathleen H. Rubins, Helmut G. Katzgraber, Ann R. Kennedy

Faculty Publications

Despite years of research, understanding of the space radiation environment and the risk it poses to long-duration astronauts remains limited. There is a disparity between research results and observed empirical effects seen in human astronaut crews, likely due to the numerous factors that limit terrestrial simulation of the complex space environment and extrapolation of human clinical consequences from varied animal models. Given the intended future of human spaceflight, with efforts now to rapidly expand capabilities for human missions to the moon and Mars, there is a pressing need to improve upon the understanding of the space radiation risk, predict likely …

Challenges During Diapause And Anhydrobiosis: Mitochondrial Bioenergetics And Desiccation Tolerance, Steven C. Hand, Daniel S. Moore, Yuvraj Patil

Faculty Publications

© 2018 International Union of Biochemistry and Molecular Biology In preparation for the onset of environmental challenges like overwintering, food limitation, anoxia, or water stress, many invertebrates and certain killifish enter diapause. Diapause is a developmentally-programed dormancy characterized by suppression of development and metabolism. For embryos of Artemia franciscana (brine shrimp), the metabolic arrest is profound. These gastrula-stage embryos depress oxidative metabolism by ~99% during diapause and survive years of severe desiccation in a state termed anhydrobiosis. Trehalose is the sole fuel source for this developmental stage. Mitochondrial function during diapause is downregulated primarily by restricting substrate supply, as a …

Habitat Suitability Estimated By Niche Models Is Largely Unrelated To Species Abundance, Tad A. Dallas, Alan Hastings

Faculty Publications

© 2018 John Wiley & Sons Ltd Aim: Data on species occurrences are far more common than data on species abundances. However, a central goal of large-scale ecology is to understand the spatial distribution of abundance. It has been proposed that species distribution models trained on species occurrence records may capture variation in species abundance. Here, we gauge support for relationships between species abundance and predicted climatic suitability from species distribution models, and relate the slope of this relationship to species traits, evolutionary relationships and sampling completeness. Location: USA. Time period: 1658–2017. Major taxa studied: Mammal and tree species. Methods, …

Multidimensional Relationships Of Herbicides With Insect-Crop Food Webs, Anamika Sharma, Prashant Jha, Gadi V.P. Reddy

Faculty Publications

Controlling weeds is critical for improving the yield and quality of crops. Herbicides are the most commonly applied pesticides in agro-ecosystems. Herbicides affect insects directly as contact damage and indirectly by influencing food supplies. The innate susceptibility, life stages, and mode of feeding of insects can affect the herbicide–insect interaction. Interaction of herbicides with insect pest and beneficial insects is mainly indirect and absence of weeds either can reduce the insect population or causes switching of host plant and hence can also increase the population. The direct effect of herbicides depends on carrier or surfactant used. Presence of herbicides also …

Adoption Of Sustainable Agriculture Practices Among Farmers In Kentucky, Usa, Bijesh Mishra, Buddhi R. Gyawali, Krishna P. Paudel, Neelam C. Poudyal, Marion F. Simon, Siddhartha Dasgupta, George Antonious

Faculty Publications

© 2018, Springer Science+Business Media, LLC, part of Springer Nature. Promoting the sustainable agricultural practices at an individual farm level is essential to ensure agricultural sustainability. This study analyzed whether and how various factors related to farm or farmers’ characteristics influence the adoption intensity of sustainable agriculture practices. We used a negative binomial regression model to fit the data collected from a mail survey of farmers in Kentucky, USA. Our results showed that the adoption intensity of sustainable agriculture practices varied significantly among agricultural districts in Kentucky. Farmers who grew row crops, had irrigation facilities, and were in favor of …

Gobbling Activity Of Eastern Wild Turkeys Relative To Male Movements And Female Nesting Phenology In South Carolina, Michael J. Chamberlain, Patrick H. Wightman, Bradley S. Cohen, Bret A. Collier

Faculty Publications

Wild turkeys (Meleagris gallopavo) use a polygynous mating system, and males must balance fitness benefits of courtship displays against costs of their reproductive strategies. Wild turkeys are the only gamebird species in the contiguous United States hunted primarily during their reproductive period. Managers attempt to implement seasons that allow for hunter satisfaction while limiting effects to reproduction and ensuring sustainable populations. To minimize illegal harvest, managers often attempt to set spring hunting seasons when gobbling activity is high and females are actively incubating nests. Gobbling activity varies significantly both temporally and spatially, and relationships between gobbling activity and reproductive phenology …

The Effect Of Exogenous Glucose Infusion On Early Embryonic Development In Lactating Dairy Cows, S. Leane, M. M. Herlihy, F. Curran, J. Kenneally, N. Forde, C. A. Simintiras, R. G. Sturmey, M. C. Lucy, P. Lonergan, S. T. Butler

Faculty Publications

The objective of this study was to examine the effect of intravenous infusion of glucose on early embryonic development in lactating dairy cows. Nonpregnant, lactating dairy cows (n = 12) were enrolled in the study (276 ± 17 d in milk). On d 7 after a synchronized estrus, cows were randomly assigned to receive an intravenous infusion of either 750 g/d of exogenous glucose (GLUC; 78 mL/h of 40% glucose wt/vol) or saline (CTRL; 78 mL/h of 0.9% saline solution). The infusion period lasted 7 d and cows were confined to metabolism stalls for the duration of the study. Coincident …

Effect Of Surrounding Vegetation On Microbial Survival Or Die-Off On Watermelon Surface In An Agriculture Setting, Vijay Singh Chhetri, Kathryn Fontenot, Ronald Strahan, Veerachandra K. Yemmireddy, Katheryn J. Parraga Estrada, Achyut Adhikari

Faculty Publications

Preharvest contamination of produce with food borne pathogens has been a major food safety issue. In this study, we investigated the effect of surrounding vegetation on the survival of natural and inoculated generic Escherichia coli on watermelon rinds in an agricultural field setting. There was no significant difference (p >.05) on the populations of natural generic E. coli (1–1.46 log Most Probable Number (MPN)/sample) and coliforms (<3.99 log CFU/cm2) on watermelons harvested from low, medium, and high levels of vegetation. However, the survival rate of generic E. coli inoculated on watermelon rind discs was variable with the level of vegetation. A significant reduction in generic E. coli count was observed within 12 hr at all vegetation levels. After 108 hr, discs placed at low vegetation level had a highest die-off reduction (3 log Colony Forming Units (CFU)/cm2) compared to medium and high vegetation levels. Practical applications: To ensure preharvest produce safety, the Food Safety Modernization Act (FSMA) produce safety rule has suggested a time interval between last irrigation and harvest for potentially contaminating microorganisms to die-off. However, a knowledge gap exists regarding the influence of surrounding vegetation on microbial die-off rates on produce in the agricultural field. The findings of this study emphasize the importance of considering the surrounding vegetation while making decisions for developing preharvest risk management strategies based on microbial die-off rate calculations.

Development Of Nanocomposite Adsorbents For Heavy Metal Removal From Wastewater, Bin Wang, Tingting Wu, Subramania Angaiah, Vignesh Murugadoss, Jong Eun Ryu, Evan K. Wujcik, Na Lu, David P. Young, Qiang Gao, Zhanhu Guo

Faculty Publications

Development of highly efficient, low cost adsorbents for heavy metal ion removal from wastewater is an enduring undertaking. Two major groups of nanocomposite adsorbents are reviewed here. The magnetic carbon family is first discussed including the preparation of such materials. Various carbon sources have been used in the preparation, and the structural characteristics have been analyzed. Cr(VI) removal studies unveil a wide range of performance. The second group adsorbents is polymer functionalized nanocomposites. One notable polymer is polyaniline which is a redox polymer. The redox nature allows the composite materials to facilitate Cr(VI) reduction to Cr(III) which is prone to …

Discussion Forum: The Vanishing Nineteenth Century In European History?, David Blackbourn, James M. Brophy, Pieter M. Judson, Alexander M. Martin, Lloyd S. Kramer, Alex Chase-Levenson, Roger Chickering, Simone Lässig, Suzanne Marchand, Karen Hagemann, Sebastian Conrad, Birgit Aschmann, Insa Kummer, Jürgen Osterhammel, Andrew Zimmerman

Faculty Publications

No abstract provided.

Design And Characterization Of A Triple-Input Microfluidic Droplet Trapping Array Towards Multiplexed And Dynamic Single Cell Analysis, Riad Elkhanoufi

Honors Capstones

No abstract provided.

High-Throughput Assessment Of A Novel, Thiol-Acrylate Hydrogel For Tumor Spheroid Synthesis In A Microfluidic Device, Nathan Daniel Kersker

LSU Master's Theses

The extracellular environment plays an important role in regulating cell behavior. The mechanical, structural, and compositional properties of the extracellular matrix can determine the fate of the growing cells. Standard two-dimensional culturing in a flask fails to represent a native cellular environment. To create the native environment suitable for cells, hydrogels were previously studied. One of the most extensively studied synthetic hydrogels was a poly(ethylene glycol diacrylate) (PEGDA) hydrogel. However, the need for UV polymerization may introduce unwanted changes in cell morphology and viability. The hydrogel being proposed was a form of a thiol-acrylate hydrogel that can eliminate this problem …

Sexually-Relevant Visual And Chemosensory Signals Induce Distinct Behaviors And Neural Activation Patterns In The Social African Cichlid, Astatotilapia Burtoni, Karen E. Field, Christopher T. Mcvicker, Karen P. Maruska

Faculty Publications

© 2018 Field, McVicker and Maruska. Across vertebrates, the use of multimodal (multiple sensory modalities) signals has evolved to convey important information to receivers. Information content of multimodal signals can be the same as or different from information in each unimodal signal, and are classified as redundant or non-redundant, respectively, based on receivers’ behavioral responses. Despite the prevalence and importance of multimodal signaling across taxa, relatively little is known about how and where these signals are processed in the brains of receivers. We used the social African cichlid fish, Astatotilapia burtoni, to investigate how sexually-relevant visual and chemosensory uni- and …

Mindfulness And Teen Behavior: Teenagers' Perceptions Of Behavior That Led To Expulsion, Michelle L. Lee

LSU Master's Theses

The purpose of this study was to examine the effects of teaching specific mindfulness techniques to teens who have difficulty functioning in the classroom, using the Mindful Schools Curricula; the course includes 18 lessons on being mindful of sound, breath, movement, thoughts, and emotions. Specifically, the study was designed to determine whether a mindfulness course would be beneficial for South Parish High School teens who are expelled. The study design was mixed methods. Participants were administered pre- and post- scientific validated survey scales that measure mindfulness characteristics as one data source. Participants’ parents were given a questionnaire to return and …

A Comparison Of Machine Learning Techniques For Taxonomic Classification Of Teeth From The Family Bovidae, Gregory J. Matthews, Juliet K. Brophy, Maxwell Luetkemeier, Hongie Gu, George K. Thiruvathukal

Faculty Publications

This study explores the performance of machine learning algorithms on the classification of fossil teeth in the Family Bovidae. Isolated bovid teeth are typically the most common fossils found in southern Africa and they often constitute the basis for paleoenvironmental reconstructions. Taxonomic identification of fossil bovid teeth, however, is often imprecise and subjective. Using modern teeth with known taxons, machine learning algorithms can be trained to classify fossils. Previous work by Brophy et al. [Quantitative morphological analysis of bovid teeth and implications for paleoenvironmental reconstruction of plovers lake, Gauteng Province, South Africa, J. Archaeol. Sci. 41 (2014), pp. 376–388] uses …

Neonatal Vitamin A Injection Promotes Cattle Muscle Growth And Increases Oxidative Muscle Fibers, Bo Wang, Wei Nie, Xing Fu, Jeanene M. De Avila, Yannan Ma, Mei Jun Zhu, Martin Maquivar, Steven M. Parish, Jan R. Busboom, Mark L. Nelson, Min Du

Faculty Publications

© 2018 The Author(s). Background: Vitamin A and its metabolite, retinoic acid (RA), are important regulators of cell differentiation and organ morphogenesis. Its impact on beef cattle muscle growth remains undefined. Method: Angus steer calves were administrated with 0 (control) or 150,000IU vitamin A (retinyl palmitate in glycerol, i.m.) per calf at birth and 1 month of age. At 2 months of age, a biopsy of the Biceps femoris muscle was obtained to analyze the immediate effects of vitamin A injection on myogenic capacity of muscle cells. The resulting steers were harvested at 14months of age. Results: Vitamin A administration …

Rats Fed Dietary Bioactive Components (Resistant Starch, Whole Grains, And Fat) Undergo Altered Biometrics And Gene Expression As A Result Of Gut Fermentation, Justin Lamont Guice

LSU Doctoral Dissertations

The whole grain and fat content of the diet have been previously shown to affect intestinal fermentation and phenotype conferred by high–amylose maize resistant starch (HAMRS), a form of fermentable dietary fiber. The current studies were designed to compare rodent gut health following consumption of whole grain and non–whole grain prebiotics on moderate fat (MF) and high fat (HF) diets, and to optimize health effect based on dosage of whole grain resistant starch prebiotics.

Study 1: Diets were prepared to contain the following factors RS (Present/Absent), WG (Present/Absent), and Fat (HF/MF). A three–way ANOVA was performed with statistical slice …

Speciation And Hybridization In Jamaican-Endemic Streamertail Hummingbirds (Trochilus Polytmus And T. Scitulus), Caroline D. Judy

LSU Doctoral Dissertations

Streamertails hummingbirds (Trochilus polytmus and T. scitulus) are recently diverged sister taxa that appear to have speciated in situ on the island of Jamaica. They are distinguished by male bill color, a secondary sexual trait that is coral red in T. polytmus and jet black in T. scitulus. They hybridize in a narrow zone where their ranges meet in eastern Jamaica. In Chapter 2, I performed a formal population survey of T. scitulus to determine the size of the population, which was unknown. I determined that the total population contains well over 100,000 individuals despite its limited …

A Systematic Investigation Of Condensation Heat Transfer Using Asymmetric Micro-Scale Surfaces, Emily Brown

LSU Master's Theses

Asymmetric surfaces been shown to inducing unidirectional motion in the Leidenfrost regime; however, very minimal research has been conducted to investigate whether these surface can enhance condensation through the same means. The investigation of heat transfer of ratchets in condensation is a relatively untapped area of study, specifically ratchets with superhydrophobic properties. Anticipated difficulty lies in creating surfaces features or coatings that retain the ratchets and can adequately sustain optimal wetting state of Cassie-Baxter required to improve heat transfer performance during condensation. This study serves to investigate whether ratchets are a feasible surface feature to enhance condensation heat transfer. First, …

Transforming Lives In Coastal Communities Through Economic Development: Breeding Crassostrea Virginica For Alternative Oyster Culture, Brian Randall Callam

LSU Doctoral Dissertations

This dissertation helped address the commercialization of triploid Crassostrea virginica production and develop tetraploid C. virginica broodstock in Louisiana by addressing triploid commercialization and tetraploid broodstock development. This was done by: 1) developing regional breeding plans for diploid and tetraploid C. virginica targeted at the Gulf Coastal Region, 2) assessing the effect of chromosome set manipulation on gonadal development in diploid, triploid, and tetraploid C. virginica, 3) quantifying the variation of commercially important hatchery traits in triploid C. virginica larvae from different tetraploid parents, 4) developing an up-to-date remote setting manual for the Gulf Coastal Region for industry use, …