Life Sciences Commons^™

Effect Of Uv-C Light Against Listeria Monocytogenes On Hydroponically Grown Lettuce And Its Effect On Quality, Ivannova Lituma

LSU Master's Theses

Controlled agriculture environments like hydroponic systems are a growing industry. However, studies have shown potential of microbial growth in hydroponic systems, highlighting the need for decontamination techniques to prevent the risk of foodborne diseases. This study evaluated the effect of UV-C light against Listeria monocytogenes on hydroponically grown lettuce and seeds. Lettuce leaves were spot inoculated (100μL) with Listeria monocytogenes cocktail and exposed to UV-C light (0.28mW/cm2) for 10 to 50 seconds in 10-second increments and 1 to 5 minutes in 1- minute increments. UV treated leaves were stored at 4C° and visually inspected for 5 days. Additionally, the smooth …

The Function Of Transport Protein Mfl1 In Arabidopsis Thaliana, Joseph Qian

LSU Master's Theses

Photosynthesis serves as the primary process for plants to synthesize ATP and sugar molecules, however, this reaction requires many cofactors such as heme, plastoquinone, and iron-sulfur clusters to assist in energy gathering and electron transfer steps. Many of these require trace metals, such as iron, to cross across the chloroplast membranes and be incorporated into proteins and other organic molecules to form useable cofactors. The light-independent reactions of photosynthesis are also inefficient, with up to 25% of the photosynthetic energy wasted to metabolize the toxic waste product glycolate. The cellular logistics of both photorespiration and iron transport have been studied, …

Recombinant Dna Vaccine Design As A Potential Strategy Against Bovine Foot And Mouth Disease Virus (Fmdv), Taylor Haynie

LSU Master's Theses

Foot-and-mouth disease virus (FMDV) is the causative agent for foot-and-mouth disease (FMD) that infects primarily cloven-hoofed animals, the majority of which are domesticated cattle and other important livestock. FMD is highly transmissible and found in all secretions and excretions of infected animals. North America, Europe, and Australia have successfully eradicated the virus with the help of a well-defined fiscal infrastructure and access to successful control measures. Less developed regions, including many Asian and African countries, have maintained an endemic status for decades. African territories are of particular concern because of the indigenous African Buffalo population that serves as an important …

Effect Of Type Of Mulch And Biological Soil Amendments Of Animal Origin (Bsaao) On Microbial Food Safety Risk On Cucumbers And Carrots Irrigated With Contaminated Or Chlorinated Water, Juan Fernando Moreira Calix

LSU Doctoral Dissertations

A comprehensive understanding of the effect biological soil amendments of animal origin and physical soil amendments have on produce contamination is important for developing strategies to mitigate this risk. Our studies investigated the persistence of generic E. coli, E. coli O157:H7 and Salmonella spp. in soil and produce surfaces with different BSAAO and mulch applications, as well as the effectiveness of chlorine treatments in reducing enteric bacteria in the field. Cucumbers harvested from plots with paper mulch had the highest levels of E. coli (3.76 Log CFU/cm²) while samples from maize mulch had the lowest levels (1.68 …

Evaluating Sensory Quality, Willingness To Try, Risk And Product Appropriateness Of Seafood Byproducts, Silvia Jessenia Murillo Miguez

LSU Master's Theses

Valorization of food wastes/byproducts has become a major subject of research to increase sustainability of the global food supply chain. Seafood industries generate a substantial quantity of byproducts. An online survey was used to evaluate Willingness-to-try (WTT), the effect of a Consumer Safety Statement (CSS) on WTT, perceived risks and product appropriateness associated with seafood byproducts in food as influenced by gender and race. Based on the finding from this survey, a clean label catfish bone powder (CBP) was developed and used for breaded catfish sticks which were evaluated for sensory liking, emotional profile, and purchase intent. Previous consumers of …

Investigating The Potential Role Of Termites As Pathogen Vectors In The Decline Of Ironwood Trees (Casuarina Equisetifolia) In Guam, Garima Setia

LSU Master's Theses

Termites have been found associated with the decline of Casuarina equisetifolia (ironwood), an important agro-forestry species in Guam. While the ironwood tree decline (IWTD) was first reported in 2002, its association with termites as well as with bacteria Ralstonia solanacearum and Klebsiella species (K. oxytoca and K. variicola) was determined in 2010 and 2012 respectively. In 2019, the termite species attacking the ironwood trees were identified as Nasutitermes takasagoensis, Coptotermes gestroi, and Microcerotermes crassus. However, the role of termites in IWTD is not known. Since termites are repositories of bacteria and consume wood, termite foragers might …

Effect Od Different Sources And Application Rates Of Sulfur On Corn And Soybean Production Systems In Louisiana, Diego Mayorga Valladares

LSU Master's Theses

Sulfur (S) is a structural component of amino acids such as cysteine and methionine and is involved in important functions within the plant like photosynthesis, carbon and nitrogen metabolism, protein synthesis of oils, and detoxification mechanisms. Sulfur deficiency in crops has intensified around the world. Some of the reasons are improvement in controlling SO₂ emissions from industries, growing usage of high analysis S-free fertilizers and augmented cropping intensity. Sulfur fertilization has become an important factor in crop production systems and fertilization guidelines for S need to be up-to-date to improve use efficiency and compensate for rising prices of fertilizers. …

The Impacts Of Immune Challenges On Fish Behavior And Physiology, Teisha King

LSU Doctoral Dissertations

For species living in dominance hierarchies, social rank dictates access to resources and often contributes to reproductive success. To ensure survival, individuals constantly evaluate trade- offs between crucial biological systems, like the reproductive and immune systems, depending on their social rank and physiological state. Little is known about how social species balance interactions between immune system function, fluctuations in social status and reproductive fitness, and the performance of behaviors necessary for maintaining social status when sick, particularly in fishes, the largest and most diverse group of vertebrates. My dissertation research uses a whole animal approach to examine how physiological profiles …

Controls Of Physical Drivers On The Formation And Toxicity Of Harmful Cyanobacteria Blooms (Cyanohabs), Courtney N. Hammond

LSU Master's Theses

Estuaries within the Gulf of Mexico are exhibiting profound alterations due to climatic changes and the implementation of coastal restoration activities. These changes are attributed to the increasing frequency of harmful cyanobacteria blooms (cyanoHABs) within Lake Pontchartrain, an estuary located in southeastern Louisiana, USA. There is a better understanding into how the opening of the Bonnet Carré Spillway (BCS) impacts cyanoHAB formations compared to the effect of other physical drivers when the spillway doesn’t dominate the system. The goal of this study is to provide a greater understanding of the baseline conditions when the BCS is closed and determine what …

Characterization Of Antiviral Immunity, Host Virus Interactions, And Toxicity Of Agrochemical Residues In The Western Honey Bee, Christopher Fellows

LSU Doctoral Dissertations

Honey bee colonies have perished at an alarming rate for over 15 years. Among the multitude of threats to bee health, virus infections and agrochemical exposure appear to be major drivers of colony loss. As virus infection is among the most damaging influences on bee health, we first investigated a putative target for antiviral immunity, termed K_ATP channels. We previously demonstrated that pharmacologically activating K_ATP channels induces the production of reactive oxygen species and increases survival during infection with Israeli Acute Paralysis Virus. Here, we demonstrate that K_ATP modulation and ROS induction reduce virus replication and enhance …

History, Annotated Gazetteer, And Bibliography Of Sarawak Ornithology, Frederick H. Sheldon, Dency F. Gawain, Daisy G. S. Kho, Rosalina Regai, Subir B. Shakya, Chin Aik Yeap

Occasional Papers of the Museum of Natural Science, Louisiana State University

Sarawak is Malaysia’s largest state, covering most of northern Borneo. It has a remarkable history of scientific bird study, starting in the 1840s and growing ever since. To set the stage for the gazetteer, which is the core of this paper, we start with a review of this history and discuss various forces that have influenced the direction of bird research in the state. Following this introduction comes the gazetteer, which is an annotated list of c. 865 sites in Sarawak where birds have been collected, studied, or regularly observed. The gazetteer provides the latitude, longitude, and elevation of each …

Louisiana Agriculture Magazine, Winter 2023

Louisiana Agriculture

Agricultural best management practices are measures that producers can take to reduce — or eliminate — farming byproducts that enter streams and groundwater. Many of these practices address fertilizer and irrigation management and the handling of pesticides and animal waste. LSU AgCenter research has helped establish these practices, and extension agents assist producers in implementing them.

This issue of Louisiana Agriculture highlights the best management practices for many of the state’s most production areas. Aquaculture specialists detail how crawfish farms can save money while meeting best management practices, and sugarcane experts tell how the AgCenter is developing new varieties to …

Effects Of Riverine Barriers On Avian Evolution In The Amazon Basin, Andre Eugene Moncrieff

LSU Doctoral Dissertations

The high biodiversity found in the Amazon Basin has long captivated the attention of naturalists and evolutionary biologists seeking to explain its origins. Early observations by Alfred Wallace highlighted the role of rivers in delimiting the geographic ranges of many species; furthermore, where rivers narrow towards their headwaters, he noted that some species cross rivers freely. A major goal of this dissertation is to investigate how these and other observations about riverine barriers might inform our understanding of how speciation unfolds in Amazonia. My approach involved generating genomic data with dense geographic sampling for manakins in the genus Lepidothrix, …

Genetic Characterization Of Resitance To Frogeye Leaf Spot Of Soybean, Gabriel D. Munoz Herrera

LSU Master's Theses

Cercospora sojina is the causal agent of the fungal disease frogeye leaf spot (FLS) in soybeans. Management of this disease consists of foliar application of fungicides and the use of resistant cultivars. However, fungicide resistance has been detected in C. sojina populations and characterization of host resistance genes is relatively limited. To overcome the latter obstacle, we aimed to identify novel resistance genes using quantitative image analysis of the SoyNAM population. Two image analysis workflows using ImageJ and PlantCV were optimized and implemented to increase reproducibility and reduce subjectivity. The quantitative measurements included disease severity, lesion count, and average lesion …

Development Of Functional Markers For Resistance To Smut And Identification Of Genes Differentially Expressed In Response To Brown Rust In Sugarcane, Jose David Cortes

LSU Doctoral Dissertations

Smut, caused by Sporisorium scitamineum and brown rust, caused by Puccinia melanocephala, are two of the most important diseases that affect sugarcane production in Louisiana and worldwide. Smut continues to cause losses in the breeding program in Louisiana. Therefore, a QTL analysis was conducted to identify molecular markers associated with resistance in F₁ progeny (162) of a biparental cross between susceptible cultivar L 99-233 and resistant HoCP 96-540. Using 1,574 single-dose SNP markers, a total of 253 linkage groups (LG) were obtained with a genome coverage of 24,580.15 cM. Six QTLs were localized on five LGs. The highest …

A Subspecies-Level Database Of Amazonian Bird Distributions, With Inferences On Suture Zones And Conservation, Marco Antonio Rego

LSU Doctoral Dissertations

Amazonia has the largest and most biodiverse tropical forest on the planet. However, the distributions of its species are still poorly understood, even for well-studied vertebrates such as birds. Available distribution maps for Amazonian birds often lack accuracy in delimiting the area where species occur. Existing distributional information for Amazonian birds is often limited to species-level level taxonomy, even though many Amazonian bird subspecies represent biological species. Here, I investigate the geographic distributions of 4,148 bird taxa (species and subspecies) using museum scientific specimens as the primary source of data. To build the data base I use more than 600,000 …

Evaluating The Viscoelastic Properties Of Alligator Skin Gelatin, Alligel, Compared To Mammalian And Fish Gelatins, Sarah E. Jimenez

Honors Capstones

No abstract provided.

Examining The Symbioses Between Bioluminescent Vibrio Species And Ponyfishes In The Indian Ocean And Between Vibrio Species And Crassostrea Virginica In The Gulf Of Mexico, Alexandra Chauvin

Honors Capstones

No abstract provided.

The Effects Of Tillage And Cover Crops On Crop Yield And Soil Properties In Wheat Double-Cropping Systems, Peters E. Egbedi

LSU Doctoral Dissertations

This three-year study was conducted on a commerce silt loam soil at the Northeast Research and Experiment Station near St. Joseph, Louisiana to evaluate the following objectives: 1) evaluate crop yield response to tillage, winter, and summer cover crops in wheat double-cropping systems. 2) evaluate the effects of tillage, winter and summer cover crops on soil properties under different cropping systems. 3) quantify the economic benefits of double-cropping, cover cropping and monoculture systems under conventional and no tillage practices. A winter cover crop (WCC) mix (winter wheat (Triticum aestivum and Austrian winter pea (Pisum sativum) and summer …

Spatiotemporal Transcriptome Diversity And Responses To Salinity Tolerance In The Extremophyte Schrenkiella Parvula, Chathura Wijesinghege

LSU Doctoral Dissertations

Schrenkiella parvula is an extremophyte model related to the most widely studied plant model, Arabidopsis thaliana and Brassica crops in the mustard family (Brassicaceae). It can thrive in highly saline environments where the soil is enriched in Na⁺, K⁺, Li⁺, borates, and chlorides. Understanding how this extremophyte can survive high salinity with genomic adaptations can provide insight into developing stress resilient crops in the future. Gene expression of S. parvula in response to salt has been investigated using shoot and root tissue from mature vegetative-phase plants. However, prior studies have not examined the transcript …

Population Genomic Characterization Of Cercospora Janseana On Rice In The Southern United States, Jacob Searight

LSU Master's Theses

Cercospora janseana is the causative agent of narrow brown leaf spot (NBLS). Effort had been undertaken since the 1940’s to control this disease through resistance breeding in the Southern United States. However, a severe epidemic of NBLS in 2006 inspired renewed focus on managing this disease. One tool for managing this disease has been identified among resistant cultivars, the CRSP-2.1 resistance locus to NBLS. One thing limiting the investment and deployment of CRSP-2.1, and other unknown resistance genes, is the historical observation that resistance to NBLS rapidly breaks-down in the field. Together, the rapid breakdown of resistance to NBLS …

Defining Understudied Mechanisms Of Potassium Ion Flux In The Insect Nervous System, Rui Chen

LSU Doctoral Dissertations

To identify novel insecticide target sites that can address the evolution of insecticide resistance, our group has tested the insecticidal potential of two potassium flux pathways: potassium-chloride (K+/Cl−) cotransporter (KCC) and inward rectifier potassium (Kir) channels. GABAergic signaling is the cornerstone of fast synaptic inhibition for neural signaling in arthropods; thus, the γ-aminobutyric acid (GABA)-receptor-chloride-channel (GRCC) complex has been a longstanding target for insecticides. Despite the importance to neuronal homeostasis, the upstream mechanisms enabling GRCC function are poorly defined. The data presented in this dissertation provide strong support that KCC is an essential ion transport system for proper neural function …

The Applied Use Of Zein Nanoparticles In Agriculture, Colin Bonser

LSU Doctoral Dissertations

Nanotechnology is a multifaceted and a promising strategy in agricultural pest management for the development of insecticides or insecticide carriers. Research has shown that nanoparticles increase stability and efficacy of entrapped chemical pesticides to prevent active ingredient degradation while improving chemical stability and solubility. The following work evaluated nanoparticles synthesized from biopolymers, materials that originate from renewable sources also have an increased biodegradability.
Work was conducted under laboratory, greenhouse, and field conditions to test the biopoloymers as possible insecticide and insecticide carriers. The primary biopolymer evaluated in the following studies was zein, although lignin and chitosan were also evaluated. Overall, …

Paraquat-Resistant Italian Ryegrass (Lolium Multiflorum) Confirmed In Louisiana, Alphonse B. Coco Iii

LSU Master's Theses

Paraquat is the only herbicide labeled for postemergence control of Italian ryegrass in sugarcane. In 2017, sugarcane farmers in Louisiana reported Italian ryegrass control failures with paraquat applications. Seeds were collected from sugarcane fields in White Castle, St. Gabriel, and Bunkie, Louisiana where control was not achieved (reduced susceptibility). Additionally, Italian ryegrass seeds were collected from a sugarcane field in Welcome, LA with a history of paraquat use and with no reported control issues (susceptible population). A dose-response study was conducted at the Louisiana State University Agricultural Center’s Sugar Research Station in February 2021 and was repeated in November 2021. …

Role Of Cd38 In Pulmonary Host Defense Against Gram-Negative Pneumonia, Xiaoqian Shan

LSU Master's Theses

The Gram-negative bacterium, Klebsiella pneumoniae, is a major cause of hospital-acquired pneumonia in the U.S. In particular, the dramatic increase in carbapenem-resistant K. pneumoniae infections poses a serious threat to the public health both in the United States and worldwide. Clearance of bacteria in the lungs depends on effective pulmonary immune response. It may be possible to design improved therapies that augment host immune responses while attenuating excessive pulmonary inflammation through modulation of key innate immunity molecules during pneumonic infections. Cluster differentiation CD38 (CD38) has been detected on the surface of many immune cells or intracellular compartments, acting as …

Impact Of Rma’S Projected Price On Prevent Planting Claims, Nicolas Enrique Alvarez Mena

LSU Master's Theses

This research studies the presence of ex-post moral hazard in the prevent planting provision from the crop insurance program in cotton, corn, and soybeans for the Plains Region and Southeast Regions of the U.S. Three fixed effect models are developed using the proportion of prevent plant acres as the dependent variable, as well as weather, input price, expected harvest price and a break-even point for the independent variables. In addition, a fourth fixed effect (FE) model is introduced using the logit transformation and the same variables as in previous models. The results show the number of PP claims has been …

Searching For The Soldier Pheromone: Behavioral Effects Of Soldiers And Soldier-Produced Chemicals In The Formosan Subterranean Termite, Coptotermes Formosanus (Blattodea: Rhinotermitidae)), Joseph Mccarthy

LSU Master's Theses

The Formosan subterranean termite, Coptotermes formosanus, is a eusocial insect and an invasive urban pest. Colonies function through a division of labor among castes (i.e., queens and kings, workers, and soldiers). Though soldiers are energetically expensive to maintain, C. formosanus has a relatively large soldier caste (~10% of the colony). Soldiers are physically unable to collect food or build tunnels but are regularly found with foraging workers. In some species, soldiers influence the worker foraging behavior. In C. formosanus, aside from defense, the roles soldiers play remains unknown. In this study, we determined if soldiers influence …

Effect Of Canopy Competition On Tree Growth And Development In Pine Hardwood Mixtures, Jacob Alexander Olichney

LSU Master's Theses

Mixed species forests may benefit from the reduction in intraspecific competition, although the benefit of species mixing has been shown to vary depending on mixture composition and environmental conditions. This study sought to test the effect of species composition in mixed forest stands on canopy development and growth of loblolly pine (Pinus taeda), cherrybark oak (Quercus pagoda), and sweetgum (Liquidambar styraciflua). Even-aged, grid planted monoculture and mixed species forest plots were established with hardwood monoculture plots at a 741 Trees Per Hectare (TPH), and pine monoculture and mixed species plots established at 1482 TPH. …

Assessing Turgor Loss Point In Bottomland Hardwood Trees Using Leaf Spectroscopy, Alexandra M. Eisley

LSU Master's Theses

Climate change is expected to radically alter our planet’s forests, with higher frequencies of drought- and flood-induced mortality events posing a challenge for forest managers and biologists. Research into the factors underlying plant tolerance to environmental stressors is therefore gaining popularity for incorporation into projective and earth system modeling using remote sensing measures. Leaf turgor loss point (TLP) is a key trait associated with drought tolerance among plants and is defined as the water potential at which leaf turgor pressure reaches zero, causing wilting. Here, I investigated patterns of TLP across the landscape and its role as an indicator of …

Esterase Mediated Insecticide Resistance In The Southern House Mosquito, Culex Quinquefasciatus, Vivek Pokhrel

LSU Doctoral Dissertations

Much is known about the development of insecticide resistance associated with targeted application against insect populations. However, off-target selection by applications of insecticides in agricultural and residential sites also impacts development of insecticide resistance and is understudied. Similarly, the impact of selecting one life stage of mosquitoes on the insecticide susceptibility of different life stages is largely unknown. The first part of this study shows that susceptibility to chlorantraniliprole, which is applied in rice and sugarcane fields in LA, decreased (5.7 to12-fold) in populations of Culex quinquefasciatus collected from near these fields compared to a reference field strain. In addition, …