Life Sciences Commons^™

Effects Of Plant Viruses On Vectors And Non-Vector Herbivores In Three Different Pathosystems, Sunil Paudel

LSU Doctoral Dissertations

Plant viruses are an important component of agro-ecosystems and the knowledge of impacts they can cause on their hosts, and on different vectors and non-vector herbivores associated with the hosts, is very crucial in devising sound management strategies for virus disease and vector control in the landscape. The interactions between these components, however, are difficult to predict and vary according to the system under investigation. In order to understand some of these interrelationships, different sets of experiments were carried out in three different pathosystems to look at the impacts of plant viruses on vector and non-vector herbivores. Firstly, in Sorghum …

The Generalization Of Fear Condition Between Viewed And Imagined Percepts, Lauryn Michelle Burleigh

LSU Master's Theses

Mental images can provoke intense emotional states (Holmes & Matthews, 2010). Imagery and perception have common neural and physiological mechanisms, including activation of the early visual areas (Albers et al., 2013). We tested the prediction that individuals can acquire fear to imagined percepts and if this fear transfers to viewing percepts, using fMRI and self-reported measures to determine participants’ fear. The participants completed a task in which they viewed and imagined two stimuli, and were fear conditioned when imagining the CS+. Participants are only told that mild electrical stimulation will be paired with one of the stimuli, but not which …

Productivity And Meat Quality With Meat Goat Management, Trent Drae Dugas

LSU Master's Theses

The growth of kid meat goats and their carcass and meat characteristics with monensin sodium or decoquinate coccidiostats in feed were studied. Seventy-three goats of various breeds were divided into six groups with the treatments of control, monensin and decoquinate. Half of the goats were harvested at day 45 and the rest at day 60. The second harvest monensin group had a larger percentage of the goat carcass as the hind leg (P

Supplementation of permanent pasture with sunn hemp forage or concentrate feed were compared for influences on growth, carcass traits, and meat properties of kid meat goats. Goats …

Strategies To Overcome Antagonism Of Quizalofop-P-Ethyl When Applied In Mixture With Other Herbicides, Lucas C. Webster

LSU Master's Theses

A field study was conducted in 2017 and 2018 at the LSU Agricultural Center H. Rouse Caffey Rice Research Station (RRS) near Crowley, LA. to evaluate the influence of different adjuvants in overcoming the antagonism of quizalofop when mixed with bispyribac in Louisiana rice production. The antagonism of quizalofop mixed with bispyribac plus HCOC at 14 DAIT was overcome with a neutral interaction observed at 28 DAIT for barnyardgrass control with an observed control of 91%, compared with an expected control of 97%. The addition of COC, SNS or HCOC into a mixture of quizalofop plus bispyribac provided synergistic or …

Ale Beer Containing Free And Immobilized Lactobacillus Brevis, A Potential Delivery System For Probiotics, Kriza Faye Albacite Calumba

LSU Master's Theses

Probiotic products can improve gastrointestinal health and probiotics in ale beer may be attractive to health-conscious consumers. However, the alcohol in beer may decrease probiotic viability. A powder produced from durian fruit (Durio zibethinus) rind, a by-product that is currently unutilized, contains large amounts of fiber which can be used to immobilize probiotics. The objective of this study was to produce ale beer with free Lactobacillus brevis (FLB) and immobilized cells (ILB) on durian rind powder (DRP) as a potential delivery system for probiotics. L. brevis was immobilized in DRP then the morphology of FLB and ILB was …

Efficacy Of Aqueous And Gaseous Chlorine Dioxide In Reducing Salmonella, E. Coli O157:H7, And Listeria Monocytogenes On Sweet Potatoes, Strawberries, And Blueberries, Phillip Luu

LSU Master's Theses

Chlorine dioxide, a stronger oxidizing agent, is effective against a broad spectrum of microorganisms. This study evaluated the efficacy of chlorine dioxide on reducing Salmonella, E. coli O157:H7, and Listeria monocytogenes on sweet potato (aqueous ClO₂), strawberries and blueberries (gaseous ClO₂). Sweet potatoes inoculated with multi-strain cocktails of each bacterial pathogen (10⁷ CFU/cm²) were treated with 5 ppm aqueous ClO₂ or water for 10, 20, and 30 minutes. Strawberries and blueberries spot inoculated with multi-strain cocktails of each bacterial pathogen (10⁷ CFU/g) were treated with gaseous ClO₂ sachets (63 mg/l for strawberry and 30 mg/l for blueberry) …

Mosquito Image Classification Using Convolutional Neural Networks, Sumanth Vissamsetty

LSU Master's Theses

Human life has always been affected by insects, especially mosquitoes, since it's early beginnings. This pesky insect acts as a vector that transmit pathogens through feeding on our blood, spreading life-threatening diseases like Zika Virus, Malaria, Dengue fever, Chikungunya and more. It is important to prevent these mosquitoes from harming humans and one way to do so is to control the mosquito population, or mosquito abatement as it is commonly known. It is important to note that not all mosquitoes are the same and each of them live, reproduce and attack in their own unique way. Hence it is crucial …

Investigating The Effects Of Cognitive Diversity On The Small Gasoline Engines Problem Solving Ability Of Undergraduate Students Enrolled In A Team-Based Learning Formatted Agricultural Mechanics Course, Whitney L. Figland

LSU Master's Theses

Perhaps the most challenging factor in teaching is being able to foster a learning environment that meets the needs of all learners, which is often achieved by utilizing a plethora of instructional methods that develop critical thinking and problem solving skills. These 21st century skills have been recurrently identified as a critical component of today’s workplace and employers are hiring individuals who can solve complex problems, especially within agriculture. However, students in todays educational classrooms are often not receiving the hands-on instruction that is needed in order to foster the development of critical thinking and problem solving skills. Further, problem …

Effects Of Dietary Sugars And Sugar Alcohols On Mortality And Thermal Tolerance In Culex Quinquefasciatus And Aedes Aegypti, Madeleine Chura

LSU Master's Theses

Aedes aegypti (L. 1762), the yellow fever mosquito, and Culex quinquefasciatus Say 1823, the southern house mosquito, are prevalent in tropical and subtropical areas worldwide and are responsible for the spread of a number of devastating diseases to humans and livestock. The development of new control methods, as well as continued study of mosquito biology, is vital for improving human health. This study aimed to examine the efficacy of sugar alcohols as a novel means for mosquito control, as well as how sugar alcohols and other factors are involved in thermal tolerance in mosquitoes.

No-choice tests with the sugar alcohols …

Environmental Controls On Dissolved Carbon Export And River Geochemistry - A Case Study In The Mississippi-Atchafalaya System, Jeremy Reiman

LSU Master's Theses

Rivers serve as an important medium for the exchange of elements between land, ocean, and atmosphere. This thesis consists of three interconnected studies with the overarching goal of analyzing the environmental factors influencing dissolved carbon dynamics and river geochemistry in large rivers. These studies utilized river water samples and in-stream measurements collected from the Mississippi and Atchafalaya Rivers at hourly to monthly intervals between 2013 to 2018, along with ambient river and meteorological data downloaded from public-access databases. Results indicate substantially higher dissolved organic carbon concentrations (DOC, 611 ±181 µmol L^-1) but lower concentrations of dissolved inorganic carbon …

Evaluation Of Reproductive Phenology And Ecology Of Eastern Wild Turkey (Meleagris Gallopavo Silvestris) Across The Southeastern United States, Nicholas W. Bakner

LSU Master's Theses

Avian reproduction is known to be a driver of population dynamics across species and systems. Behavioral decisions during incubation such as habitat selection and nest attentiveness are thought to affect nest success. The incubation process is a costly period during which individuals are sedentary and must balance survival with reproductive success and overall fitness. Current understanding of Eastern wild turkey incubation behavior provides a limited view of the incubation period. Using GPS data collected from Eastern wild turkeys (n = 220), I evaluated nest fate as it relates to recess frequency, distance travelled during recess, and habitat selection during …

Improving Coupled Enzyme Assays With Capillary Electrophoresis, Thu Hoai Nguyen

LSU Doctoral Dissertations

The goal of this project is to address limitations of coupled enzyme assays using capillary electrophoresis (CE). In some enzyme assays, it is ineffective to directly detect products and substrates spectroscopically (absorption or fluorescence). Coupling the enzyme-catalyzed reaction of interest with another enzyme-catalyzed reaction allows for indirect detection of product formation or substrate depletion for the target enzyme. While conventional coupled enzyme assays are facile for kinetic measurements, they can be problematic for inhibition screening due to spectral and inhibitor interferences. To address these limitations of coupled assays, CE has been used to develop enzyme assays for acetyl-coenzyme A carboxylase …

Effect Of Environmental Factors And Residual Sanitizers On Survival And Attachment Of Indicator Organism And Human Pathogens On Fresh Produce, Vijay Singh Chhetri

LSU Doctoral Dissertations

A comprehensive understanding of the behavior of microbial contaminants on produce surfaces in agricultural farms and during post-harvest activities is essential for the development of produce safety risk management strategies. Our studies investigated the survival and the attachment of E. coli on watermelon surfaces in agricultural settings with different levels of vegetation, and the effect of residual sanitizers on the survival and the attachment of E. coli O157: H7 and L. monocytogenes on spinach leaves. The attachment strength (S_R) of the E. coli cells on watermelon surfaces significantly increased (P<0.05) from 0.04 to 0.99 in the first 24 h, which was primarily due to the decrease in loosely attached population, given that the population of strongly attached cells was constant. The daily die-off rate of E. coli ranged from -0.12 …

Blueberry Pectin-Anthocyanin Binding Kinetics And Stability Under In Vitro Digestion, Jee Won Koh

LSU Doctoral Dissertations

Blueberry pectins were sequentially extracted from highbush blueberry powder and precipitated in alcohol to obtain water soluble fraction (WSF) and chelator soluble fraction (CSF). WSF was high methoxyl pectin (degree of esterification: 53), rich in in neutral sugars (40 mol%), and had less negative charge (-21 mV) whereas CSF was low methoxyl pectin (degree of esterification: 21), rich in uronic acids (92 mol%), and had lower negative charge ( -26 mV).

The stability of blueberry pectin-anthocyanin complex was investigated under simulated in vitro digestion. Binding of blueberry pectins with three anthocyanin standards (malvidin-3-glucoside; M3G, cyanidin-3-glucoside; C3G, and delphinidin-3-glucoside; D3G) and …

Sensory Analysis For Determining The Influence Of Visual Stimuli Upon Eating Experiences, Pitchayapat Chonpracha

LSU Doctoral Dissertations

Consumers are currently more conscious about salt and sugar intake than they were in the past. Visual cues have been shown to impact consumers’ cognitive and their taste perceptions. Current research information about visual cues enhancing human’s tastes expectation of saltiness and sweetness is limited. The sophisticated sensory analysis for products containing a reduced amount of salt and sugar is undoubtedly time–consuming and costly if the sensory experiment is designed with many samples. Therefore, the following three studies were achieved: I) an examination of how intrinsic and extrinsic visual cues affect the overall consumer eating experiences; II) a comparison of …

The Tripartite Interaction Between Arbuscular Mycorrhizal Fungi, Rice, And Insects, Lina Bernaola Alvarado

LSU Doctoral Dissertations

Losses caused by pests remain an important limitation to achieving high rice yields in the United States. Arbuscular mycorrhizal fungi (AM fungi) are able to modify plant physiology by increasing plant growth or inducing defense responses against insect herbivores. However, studies of the role of AM fungi in agroecological factors, including natural occurrence, plant resistance, soil dependency, and plant tolerance, with specific regards to pests that feed on rice plants have not been conducted before. A three-year study revealed natural occurring colonization by AM fungi on rice roots sampled in four rice-producing areas in the southern United States. Overall, rice-AM …

The Drosophila Neuroblasts: A Model System For Human Ribosomopathies, Sonu Shrestha Baral

LSU Doctoral Dissertations

This dissertation describes the use of Drosophila neuroblasts (NBs) to model human ribosomopathies; the overall goal is to understand why specific stem cell and progenitor cell populations are the primary targets in nucleolar stress as seen in the ribosomopathies. Chapter 1 provides an overview of relevant literature. Chapter 2 describes nucleolar stress in Drosophila neuroblasts as a model for human ribosomopathies. For this, we induce nucleolar stress by using the UAS-GAL4 system to express RNAi that depletes Nopp140 transcripts, and we also employ homozygous, CRISPR-Cas9-generated Nopp140 gene disruptions with a systemic null phenotype (Nopp140-/-). Embryonic lethality was observed …

Understanding Host-Fungus Interactions Between Soybean And Phakopsora Pachyrhizi To Enhance Soybean Resistance To Rust Disease, Dongfang Hu

LSU Doctoral Dissertations

Asian soybean rust (ASR) caused by Phakopsora pachyrhizi was first reported in Japan in 1902. In 2004, Asian soybean rust was first reported in Louisiana and other Southeastern US states. It is one of the most important soybean diseases worldwide. Even though fungicide application can offer some protection and prevent severe yield losses caused by ASR if applied promptly, it is not a viable option as a long-term disease control measure because it increases the growers’ operation costs and the risk of environmental pollution. In addition, it also increases the chances of developing fungicide resistance within a pathogen population. The …

Development Of Sheath Blight-Resistant Breeding Lines For Southern U.S. Environments And Morphological And Genetic Survey Of Giant Salvinia Populations In Louisiana And Texas, Dominique Clark Galam

LSU Doctoral Dissertations

The southern US environment is a very conducive environment for agriculture and fisheries. Rice farming, shrimping and water related activities help drive the local economy. However, there are several factors that impede the success of these activities. Sheath blight (SB) disease caused by Rhizoctonia solani is one of the major biotic constraints to high grain yield and quality for most commercial U.S. rice varieties. Although different breeding lines with high levels of "partial resistance" have been developed none has been used directly as a commercial variety. The first research objective of this research was to identify and develop advanced breeding …

Identification And Characterization Of Novel Transporters Involved In The Co2 Concentrating Mechanism Of Chlamydomonas Reinhardtii, Ananya Mukherjee

LSU Doctoral Dissertations

The green alga Chlamydomonas reinhardtii possesses a CO₂ concentrating mechanism (CCM) which helps in successful acclimation to low CO₂ conditions. One of the main aspects of the CCM is bringing in inorganic carbon (Ci) into the cell as bicarbonate using Ci transporters. Current models of the CCM postulate that a series of ion transporters bring HCO₃^- from outside the cell to the thylakoid lumen where the carbonic anhydrase, CAH3, dehydrates accumulated HCO₃^- to CO₂, raising the CO₂ concentration for Rubisco. Previously, HCO₃^- transporters have been identified at both the …

Mechanisms To Regulate Genes Encoding Clinically Relevant Multidrug Transporters At The Crossroads Of Antibiotic Resistance And Oxidative Stress Detection, Afsana Sabrin

LSU Doctoral Dissertations

Multiple Antibiotic Resistance Regulators (MarRs) are DNA binding proteins involved in bacterial survival and pathogenesis. My PhD dissertation focuses on a MarR homolog, OstR, which regulates genes encoding major multidrug transporters, a resistance-nodulation-division (RND) and an E. coli multidrug resistance B (EmrB) efflux pump homolog in Burkholderia thailandensis. The ostR gene is divergently oriented from genes encoding a hypothetical protein (Hyp) and an RND transporter and adjacent to a gene encoding an EmrB transporter. OstR binds to the promoters of each gene (K_d = 64.9 ± 8.0 nM, K_d = 126.1 ± 10.9 nM and K …

Phylogeny And Evolution Of Swallows (Hirundinidae) With A Transcriptomic Perspective On Seasonal Migration, Clare Elisabeth Brown

LSU Doctoral Dissertations

Evolutionary biology seeks to understand the forces that have generated and shaped patterns of diversity. In this dissertation, I investigated phylogenetic relationships and the evolution of three traits—migration, nest-type, and geographic distribution—in the swallow family (Hirundinidae), a globally distributed group of about 85 species of aerial insectivorous birds. I first applied a dataset of several thousand ultraconserved element (UCE) loci to reconstructing the phylogeny of the New World genus Tachycineta. Three methods of phylogenetic inference produced topologically discordant trees, but post-inference analyses provided evidence that the tree produced by maximum likelihood analysis of a concatenated data matrix is the most …

Population Dynamics And Demographics Of Spotted Seatrout, Cynoscion Nebulosus, Through Spatial Analysis: Towards An Integrative Management Approach, Ashley Melancon Baer

LSU Doctoral Dissertations

Spotted seatrout (Cynoscion nebulosus) is one of the most highly prized sportfish along the Gulf of Mexico coast, particularly in Louisiana. Although spotted seatrout are considered to be well managed and sustainably fished according to the state’s most recent stock assessment, the spatial ecology of this species is largely understudied in Louisiana waters. Acoustic telemetry is an innovative technology that is commonly used to assess the movements and behavior of aquatic species, and can be used as a tool to address the paucity of information on the spatial dynamics of spotted seatrout. The focus of this study was …

The Aqueous Environment As An Active Participant In The Protein Folding Process, Michal Brylinski

Faculty Publications

Existing computational models applied in the protein structure prediction process do not sufficiently account for the presence of the aqueous solvent. The solvent is usually represented by a predetermined number of H2O molecules in the bounding box which contains the target chain. The fuzzy oil drop (FOD) model, presented in this paper, follows an alternative approach, with the solvent assuming the form of a continuous external hydrophobic force field, with a Gaussian distribution. The effect of this force field is to guide hydrophobic residues towards the center of the protein body, while promoting exposure of hydrophilic residues on its surface. …

Genetic Analysis Of Drought Tolerance In Rice (Oryza Sativa L.), Uttam Bhattarai

LSU Doctoral Dissertations

Drought is a major challenge in rice production system worldwide. We conducted a phenotypic screening of the USA rice genotypes for drought tolerance and assessed genetic diversity using SSR markers. Identification of QTLs for drought tolerance during both vegetative and reproductive stage was done using genotyping by sequencing (GBS) based saturated SNP linkage map. The rice genotypes Jes, Leah, Roy J, Jazzman, and Madison were found to be drought tolerant. Population structure analysis grouped the USA rice genotypes into California, Louisiana, and Arkansas types. Marker-trait association showed that markers RM570 and RM351 were significantly associated with grain yield, spikelet fertility, …

Vegetation Phenology And Nest Survival: Diagnosing Heterogeneous Effects Through Time, Kevin M. Ringelman

Faculty Publications

bias; duck; grassland; mallard; prairie; Robel; waterfowl; WATERFOWL PRODUCTION; HABITAT SELECTION; ARTIFICIAL NESTS; MOTTLED DUCKS; WINTER-WHEAT; SUCCESS; NORTH; PREDATION; CONCEALMENT; FIELDS

Deepdrug3d: Classification Of Ligand-Binding Pockets In Proteins With A Convolutional Neural Network, Michal Brylinski, Limeng Pu, Rajiv Gandhi Govindaraj, Jeffrey Mitchell Lemoine

Faculty Publications

Comprehensive characterization of ligand-binding sites is invaluable to infer molecular functions of hypothetical proteins, trace evolutionary relationships between proteins, engineer enzymes to achieve a desired substrate specificity, and develop drugs with improved selectivity profiles. These research efforts pose significant challenges owing to the fact that similar pockets are commonly observed across different folds, leading to the high degree of promiscuity of ligand-protein interactions at the system-level. On that account, novel algorithms to accurately classify binding sites are needed. Deep learning is attracting a significant attention due to its successful applications in a wide range of disciplines. In this communication, we …

Host Sex, Size, And Hemoparasite Infection Influence The Effects Of Ectoparasitic Burdens On Free-Ranging Iguanas, Christine Lattin

Faculty Publications

Investigations focusing on host-ectoparasite interactions in animals have revealed asymptomatic to severe health and fitness consequences suggesting that species mobilize different interspecific response mechanisms. Fewer studies, however, have examined intraspecific responses to ectoparasitic burdens. In this study, we analyzed host health and fitness responses to increasing ectoparasite burdens along with the presence/absence of hemoparasites of free-ranging insular rock iguanas (Cyclura cychlura) in The Bahamas. Using hematology, plasma biochemistry, as well as body condition and growth rate comparisons, we failed to find significant associations of tick burdens with annual growth rate, corticosterone, packed cell volume, total white blood cell, and heterophil, …

Habitat Usage Patterns Of Bottlenose Dolphins (Tursiops Truncatus) In Terrebonne And Timbalier Bays, Louisiana, Mary Allison Manning

LSU Master's Theses

I coupled fine-scale environmental data with observed behavior and group composition data to examine overall distribution within the bay system and to characterize the habitat associated with foraging and the presence of calves. Semi-isolated populations of bottlenose dolphins (Tursiops truncatus) along Louisiana’s coast are undergoing increased risks from boat traffic, oil spills, land subsidence, and planned water diversions (CPRA 2017). Characterizing the habitat use of bottlenose dolphins in Terrebonne and Timbalier bays, Louisiana, is important given the likely high site fidelity, small home ranges, and low exchange of individuals with nearby coastal populations (Lane et al. 2015, McDonald …

Effects Of Red Raspberry Polyphenols And Metabolites On Biomarkers Of Inflammation And Insulin Resistance In Prediabetes And Type 2 Diabetes, Reynaldo Moreno Ucles

LSU Doctoral Dissertations

Berry fruits are rich sources of polyphenolic compounds (PCs), which can promote health benefits. Anthocyanin concentrations of red raspberry (RR)(Rubus idaeus) extracts were determined to be a total of 887.6 ± 262.8 μg/g cyanidin-3-sophoroside (C3S) equivalents with C3S being the most prevalent. Ellagitannin analysis by MALDI-TOF indicated sanguiin H-6 and lambertianin C were the major ellagitannins present in RR. To explore the efficacy of RR in modulating diabetes, seven type 2 diabetes mellitus (T2DM) and two pre-diabetic patients were given drinks delivering one RR serving (123 g) per day in a smoothie for two weeks. Blood samples were …