Life Sciences Commons^™

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. …

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 …

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. …

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 …

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 …

Immunohistochemical Localization Of Kisspeptin And Its Receptor In The Equine Ovary, Bryce M. Gilbert

LSU Master's Theses

Kisspeptin is recognized for its role as the gatekeeper of reproduction in most mammalian species. However, its role in regulation of reproduction at the ovarian level is poorly understood in the horse. In this study, ovaries from follicular phase, luteal phase, anestrous period, and mares treated with ECP-sulpiride were subjected to immunohistochemistry to characterize kisspeptin-10 (Kp10) and its receptor (Kiss1r) protein expression throughout each reproductive stage and follicle type. Kisspeptin and receptor staining was detected in all follicle types (primordial, preantral, and antral) throughout all reproductive stages, as well as oocytes, corpora lutea, and ovulation fossa. The pattern of Kp10 …

Understanding Motivations Among Sustained Cooperative Extension Partners For Obesity Prevention In Rural Louisiana, Catherine R. Losavio

LSU Master's Theses

Louisiana consistently has one of the highest rates of obesity in the nation with higher concentrations of obesity in many rural parishes (i.e., counties). Due to over a century of visibility and engagement in rural communities, Cooperative Extension (Extension) is uniquely poised to reach remote rural communities disproportionately impacted by obesity. As Extension increases its use of community coalitions and implements its new National Framework for Health Equity and Well-Being, understanding motivations and communication preferences among long-term rural coalition partners for obesity prevention and health promotion has become essential for duplicating successful local-level policy, system, and environmental (PSE) changes. This …

Louisiana Agriculture Fall, 2022

Louisiana Agriculture

Livestock industries contribute $2.5 billion to the state’s economy, and beef cattle production is one of the most important sectors of the state’s agricultural enterprise. LSU AgCenter researchers study how to improve cattle production at research stations across the state. AgCenter Extension agents in every parish connect producers with their findings.

In this issue of Louisiana Agriculture magazine, livestock agents and research faculty describe the many programs they have developed to educate cattle producers and help 4-H’ers raise and show animals. Producers discuss what they have learned from Master Cattleman classes, and writer V. Todd Miller details how some cattle …

Effects Of Sensory Cues On Product Acceptability And Consumer Perceptions, Emotions, And Behavior, Cristhiam Gurdian Curran

LSU Doctoral Dissertations

Visual and cognitive cues can affect overall liking (OL) and consumer perceptions, emotions, and behavior. The first study explored the effect of product color difference on the liking, perception, and purchase intent (PI) of cheese-flavored-tortilla chips (CFTC) formulations (A and B) on serving plates (plastic, foam, and paper). Color differences between formulations influenced crunchiness and saltiness liking and perception, which together with overall flavor liking and formulation, mainly determined CFTC OL. Although having similar fracturability (N) and sodium content, formulation A had higher crunchiness and saltiness likings. PI was influenced by crunchiness, saltiness, and OF liking with 37, 49, and …

Role Of Nucleobindin-2/Nesfatin-1 In The Regulation Of Energetic Status And Maternal Mouthbrooding In The Cichlid Fish, Astatotilapia Burtoni, Saachi Chugh

LSU Master's Theses

Feeding and energetics are fundamental processes in all species that must also be balanced with reproductive investment. The peptide hormone nesfatin-1 is encoded by the nucleobindin-2(nucb2) gene and has recently emerged as a key player involved in both feeding and reproduction across vertebrates. How nesfatin-1 might help regulate trade-offs between feeding and reproduction, however, are relatively unexplored. The female cichlid fish Astatotilapia burtoniis an ideal system to examine the role of nesfatin-1 in regulating metabolic and reproductive functions because this species cycles between a gravid feeding state while preparing to mate, followed by a forced starvation …

The Effects Of Drought And Shade On Bottomland Hardwood Regeneration, Charles Joseph Pell

LSU Doctoral Dissertations

Floodplain forests support a high diversity of tree species adapted to regenerate under fluctuating water and light availability. Regeneration regulates species composition, and shade and flood tolerance influence the likelihood of regeneration. Regeneration failure of shade-intolerant and flood-tolerant tree species commonly occurs in southcentral and southeastern floodplain forests of the United States, also known as bottomland hardwoods (BLHs). In many BLHs reduced flooding has resulted in a dryer floodplain. These changes in flooding are linked to recent shifts in species composition. The mechanisms controlling regeneration in BLHs and these composition shifts are poorly understood. In a controlled germination experiment, I …

Application Of Organic Fertilizers For Lawn Establishment And Maintenance In Louisiana, Matthew Lambert

LSU Master's Theses

Landscape contractors are increasingly interested in organic products for Louisiana's residential and commercial turfgrass areas. However, the use, motivations, and barriers to adopting organic practices in the commercial turfgrass and landscape industry are undocumented. A survey with Louisiana Turfgrass Association (LTA) members to gauge their perceptions on current and future use of organic products in Louisiana was performed; and a field trial was conducted to evaluate organic fertilizers during turfgrass establishment. Substantial majorities of turfgrass professionals are currently applying organic fertilizers and believe organic product use will increase due to consumer demands, potential governmental regulation, and the belief that they …

Qualifying Factors That Predict Weight Loss Success Within Diet Interventions, Jordan Losavio

LSU Master's Theses

Evidence-based diet strategies lead to weight loss for some, while for others, the same diet approach could result in trivial weight loss or even in weight gain. This prompts the underlying research question: what factors predict that a given diet strategy will be efficacious for some, but not for others? This research was a secondary analysis of clinical weight loss studies to determine which factors influence an individual’s weight loss success for three diet intervention strategies: low-carbohydrate, low-fat, and low-calorie. A combination of physiological, psychological, behavioral, and dietary factors was evaluated for each diet study. Multiple linear regression and logistic …

Integration Of Remote Sensing Approaches For In-Season Nitrogen Management, Murilo De Santana Martins

LSU Doctoral Dissertations

Nitrogen (N) management is being conducted at flat rate in Louisiana due to practicality and convenience, but the price of N fertilizer and high breakeven costs are forcing producers to find ways to reduce costs and optimize N application. In this scenario, precision agriculture technologies, specifically the use of optical sensors on board of unmanned aerial systems (UAS) to variable rate N application on farm is showing a promising approach to save inputs and reduce environmental impacts. However, the general goal of this research was to develop and evaluate in-season N management approaches for N recommendation in corn (Zea …

Developmental Competence Of Oocytes Derived From Seasonally Anovulatory Mares Treated With Estradiol And Sulpiride, Michelle O. Vetter

LSU Master's Theses

Over the course of two years (2021-2022), two experiments were conducted during the nonbreeding seasons to evaluate the in vitro developmental potential of oocytes derived from seasonally anovulatory mares treated with ECP-sulpiride. The objective of experiments 1 and 2 were to compare pooled recovery and maturation rates of oocytes from mares treated with estradiol cypionate (ECP) and sulpiride with oocytes collected from naturally transitional mares (controls). Cleavage rates of oocytes subjected to intracytoplasmic sperm injection (ICSI) were compared only in experiment 2. In experiments 1 and 2, a total of 36 light horse and pony-cross anovulatory mares were used. Treatment …

Understanding The Horse Fly Species And Species Relations Of The Tabanus Nigrovittatus Complex Along Coastal Louisiana, Darrius M. Davis

LSU Master's Theses

The Dipteran family Tabanidae is among the most diverse families of insects that is comprised of approximately 144 genera with 4455 described species (Pape et al. 2011). Members of the family Tabanidae have been studied for well over 100 years in Louisiana. Hine (1906, 1907) conducted the first surveys of the members of the tabanid family and noted the presence of 14 species. Jones and Bradley (1923) supplemented Hine’s observations with their own inventory of horse flies across four parishes and found an additional 14 species that were not recorded by Hine. Subsequently, Tidwell (1970, 1973) conducted a survey of …

Soil Moisture Mediated Behavioral And Physiological Alterations Of Coptotermes Formosanus And Reticulitermes Flavipes (Blattodea: Rhinotermitidae), Steven J. Richardson

LSU Master's Theses

Substrate moisture is a critical environmental factor for the survival and behavior of subterranean termites (Blattodea: Rhinotermitidae). The invasive Formosan subterranean termite (Coptotermes formosanus) and the native eastern subterranean termite (Reticulitermes flavipes) co-occur in the southeastern United States, but C. formosanus is predominant in subtropical and R. flavipes is more common in temperate regions. The difference in their geographic distributions is largely attributed to their different behavioral and physiological ecology. While ample research has been done on foraging behavior of the two species, there was no empirical evidence for the effects of constant soil moisture on …

Analysis Of Geographic Variability Of Fecal Microbiomes Of Fratercula Arctica And Cross-Comparison Of Fecal Microbiomes Of Different Avian Feeding Types, Eric Jose Ramon Martinez

LSU Master's Theses

Gastrointestinal (gut) microbiota have a multitude of effects on their host, from aiding in digestion, to facilitating nutrient uptake, detoxification, and interactions with the immune system. Multiple factors have been identified that influence the composition of vertebrate microbiomes; these include host genetics, environmental conditions, diet and age, sex, and geography. However, broad inferences about wild avian gut microbial diversity and function under natural conditions are limited. Most knowledge on avian microbiomes is derived from studies on domestic poultry. Information on non-model taxa may provide important contextual information about vertebrate host-microbiome interactions and aid in future management of vulnerable species. Here, …

Cover Cropping: Sensor-Based Estimations Of Biomass Yield And Nutrient Uptake And Its Impact On Sugarcane Productivity, Hector H. Fajardo Duran

LSU Master's Theses

Sugarcane in Louisiana can be harvested for up to three years from one planting. Soil cultivation along sides of established beds is done for weed control and improve fertilizer use efficiency which increases the risk of soil degradation and yield decline. Planting cover crops (CC) is a soil conservation practice and an effective strategy to improve soil health and nutrient recycling. Limited work has been done on remote sensor-based evaluation of the potential nutrient benefits from cover crops and its effect on nutrient cycling on sugarcane systems. This study was conducted to evaluate the effect of two planting methods (broadcast …

The Importance Of Co2 Recapture In The Co2 Concentrating Mechanism Of Chlamydomonas Reinhardtii, Ashwani Rai

LSU Doctoral Dissertations

The aim of this thesis is to investigate the CO₂ concentrating mechanism (CCM) of Chlamydomonas reinhardtii and to develop a quick method for estimating the activity of carbonic anhydrases (CAs). The first project demonstrates that there are two almost identical mitochondrial CAs in C. reinhardtii, CAH4 and CAH5, that help to maintain photosynthesis and minimize the leak of CO₂ generated by respiration and photorespiration. We used an RNAi approach to reduce the expression of CAH4 and CAH5 so that their physiological functions could be studied. RNAi mutants with low expression of CAH4 and CAH5 have impaired rates …

Breeding Ecology Of Mottled Ducks In Southwestern Louisiana, Elizabeth Sophia Bonczek

LSU Doctoral Dissertations

Mottled ducks are a resident species found in the southern United States that rely on coastal marsh and associated habitat to fulfill the needs of the entirety of their annual cycle. Population monitoring has revealed declines in western Gulf Coast (WGC) mottled ducks since 2008. Mottled duck populations are influenced by survival and recruitment, and changes in these factors may contribute to population declines. The overarching goal of this project was to identify the mechanisms potentially limiting WGC mottled ducks.

I captured adult female mottled ducks during molt on Rockefeller Wildlife Refuge and adjacent lands in southwestern Louisiana from 2017–2019. …

Chloride Channels That Mediate A Transient Nitric Oxide-Dependent Synaptic Polarity Switch In Retinal Amacrine Cells., Tyler Christopher Rodriguez

LSU Doctoral Dissertations

Cytosolic chloride (Cl^-) concentration determines whether GABAergic and glycinergic synapses are inhibitory or excitatory. Ionotropic GABA and glycine receptors passively conduct Cl­^- leading to membrane depolarization or hyperpolarization depending on the Cl^- equilibrium potential. Accordingly, the distribution of Cl^- across the plasma membrane has the potential to determine the properties of networks of retinal amacrine cells (ACs) and their postsynaptic partners. Ion channels are responsible for establishing Cl^- reversal potential. Nitric oxide (NO) is a signaling molecule that can be generated in the inner retina where ACs form synapses. We have shown that NO …

Louisiana Agriculture Summer, 2022

Louisiana Agriculture

LSU AgCenter researchers constantly search for ways to improve Louisiana agriculture by increasing yields and profitability. They also seek to understand new and less popular crops that could thrive in our region. Professor Yan Chen is helping develop the tea industry along the Gulf Coast, working closely with producers to understand how to grow tea (Camellia sinensis) in the region, and her work is featured in the latest issue of Louisiana Agriculture magazine. The magazine also includes a look into Grow Louisiana and Growing Farmers, two programs designed to help beginning farmers learn the business. Researchers from the …

A New Insight Into Fungal Cell Wall Architecture By Functional Genomics And Solid-State Nmr Along With Recent Advancements In Dynamic Nuclear Polarization For Analyzing Biomolecules, Arnab Chakraborty

LSU Master's Theses

This dissertation summarizes the findings related to the way by which supramolecular architecture of fungal cell wall changes with genetic mutation, dispensing genes responsible for biosynthesis of cell wall polysaccharides. This is necessary because without perfect picture of how supramolecular assembly changes with genetic mutation it is hard to assess new anti-fungal targets. Alongside this we have highlighted how recent advancement into Dynamic Nuclear Polarization (DNP) methods improved characterization of biomolecules both in case of labeled and unlabeled samples.

First study utilized Solid-state NMR (SSNMR) which is a non-destructive technique hence enabled us for the first time to deduce how …

Evaluating The Effect Of Coated Urea And Urea-Ammonium-Nitrate Solution On Cane Tonnage, Sugar Yield, And Leaf-Soil Nitrogen Content Under Louisiana Sugarcane Production System, Hector J. Mendoza Lagos

LSU Master's Theses

Nitrogen (N) is a crucial nutrient for proper plant growth and development. N deficiency results in poor tillering and thin, short internode stem production for sugarcane production, thus resulting in low cane tonnage. Therefore, proper N fertilizer management is essential for a sustainable sugarcane production system. This research was conducted at the LSU AgCenter Sugar Research Station in St. Gabriel, LA, from 2019 to 2020 at three Sites (Site 1, 2, and 3). The treatments consisted of different N rates (0, 45, 90, and 135 kg N ha^-1) and sources (urea-ammonium-nitrate solution [UAN]-32%, 30-day [Coated Urea 1], 45-day …

Examination Of Pre-Emergence Control Of Johnsongrass In Sugarcane Seedlings, Carleton Baucum

LSU Master's Theses

Sugarcane is susceptible to many diseases and insect pests; therefore, to maintain high sugar yield new varieties must be developed. Producing new varieties contributes to the overall crop success through enhanced yield, insect and/or disease resistance, cold tolerance, and ratooning ability. However, unlike conventional sugarcane, which is vegetatively propagated, new sugarcane varieties are produced from true seed. These seedlings are more susceptible to herbicidal injury and weed competition than conventional sugarcane. For sugarcane seedlings to succeed, weeds must be controlled therefore, the most effective herbicide program with regards to seedling safety must be implemented. The objectives of this research were …

Experts’ Views On Issues Affecting Egg Labeling In The United States: A Delphi Study, Rexanna Powers

LSU Doctoral Dissertations

When purchasing food, many consumers have reported they question the ethical and humane treatment of products derived from animals at the point of purchase. To complicate this issue further, many U.S. consumers lack exposure, interaction, and involvement with the agricultural industry. As a result, they have reported a willingness to pay premium prices for meats, dairy, and eggs whose packaging suggests quality welfare practices. Therefore, the purpose of this investigation was three-fold: (1) establish operational definitions for poorly understood poultry industry terms, i.e., cage-free, free-range, pasture-raised, and organic; (2) describe experts’ perceptions of the strengths, weaknesses, opportunities, and threats (SWOT) …

The Adoption Of Conservation Practices And Program Participation Among Socially Disadvantaged Agricultural Producers: A Meta-Analysis, Myles A. Brown

LSU Master's Theses

As climate change has become undeniable in recent years, it has become increasingly important for the agriculture industry to address conservation. Within the agriculture industry, small farmers are usually the ones who take on this burden on a daily basis. However, some socially disadvantaged agricultural producers face unique challenges compared to the average farmer, which may impede their ability to adopt the necessary conservation practices or participate in conservation programs. This review sought to provide a definitive economic analysis on the possible effect of race on conservation adoption and program participation, as there is not much research on this topic. …

Louisiana Agriculture Spring, 2022, Lsu Agcenter

Louisiana Agriculture

LSU AgCenter researchers and extension agents are well known for their contributions to rice breeding, horticulture and helping the seafood industry, and examples of this important work are featured in the Louisiana Agriculture spring issue. Another AgCenter program, the Healthy Communities initiative, works throughout the state to improve the healthfulness and well-being of Louisiana residents. The initiative aims to make Louisiana towns healthier places to live, work, learn and play. Three articles in this issue of the magazine detail the activities of the researchers and agents involved in this important work.