Life Sciences Commons^™

Farmer's Adaptive Capacity And Adoption Of Strategies To Climate Change Among Mountain Communities In Nepal, Tanvir Hossain

LSU Master's Theses

Climate change presents significant challenges to agriculture worldwide, particularly where farming is central to livelihoods. This phenomenon has been linked to decreasing crop yields due to rising temperatures and reduced rainfall, particularly affecting low-income countries with limited adaptive capabilities. Grasping how farmers perceive climate change is essential for developing effective adaptation strategies to lessen its adverse impacts. This study concentrated on investigating the perceptions and adaptive strategies employed by smallholder farmers in Nepal's Mustang district, utilizing primary data sources. Data from 131 randomly selected households were gathered through structured interviews, while focus group discussions provided qualitative insights into farmers' views …

The Influence Of Stage Of Ripeness On Consumer Perceptions Regarding Selected Aspects Of Non-Astringent Asian Persimmons (Diospyros Kaki Thunb), Robert A. Mirabello Jr

LSU Doctoral Dissertations

Asian Persimmon (Diospyros kaki Thunb.) is an important fruit crop in Asia and in recent decades has experienced expanding production around the world. Non-astringent cultivars are highly desirable in world markets. In the United States the Asian Persimmon is lesser known and consumed although it can be successfully grown in California and the Southeastern United States.This novel study examined the physical/chemical properties of the non-astringent Asian Persimmon ‘Jiro’ grown in Southern Louisiana at three distinct stages of ripeness described as Green (mid-September harvest), Light Orange (mid-October harvest) and Dark Orange (mid-November harvest). Data collected included color, weight, size, soluble …

Optics Design And Fabrication For A Lung Interferometry-Radiography System, Rachael Lyn Blair

LSU Master's Theses

Purpose: High prevalence of lung diseases leads to many people worldwide needing spirometry and imaging testing. The typical imaging done uses chest radiography and/or low-dose CT. Lung tissue is difficult to visualize, making them substandard for monitoring lung disease progression. An improvement on these systems is x-ray interferometry which produces additional images that provide better visualization of changes in the lung tissue. The set-up of x-ray interferometry builds upon other imaging systems in that it includes diffraction gratings.

Materials: This thesis focused on implementing the fabrication processes to create diffraction gratings for a lung imager prototype that is currently under …

Impact Of Early-Season Postemergence Co-Applications Of Foliar And Residual Herbicides On Crop Injury, Growth, And Yield In 2,4-D- And Dicamba-Tolerant Cotton (Gossypium Hirsutum L.), Logan N. Vallee

LSU Master's Theses

Studies were conducted in 2021 through 2023 at the LSU AgCenter Dean Lee Research and Extension Center near Alexandria, LA to determine the sensitivity of 2,4-D- or dicamba- tolerant cotton (Gossypium hirsutum L.) to an early season application of a Group 15 and foliar-only herbicides. Both studies were randomized complete block designs with a two-factorial arrangement of treatments with four replications. In the dicamba-tolerant cotton study, Factor A consisted of no foliar-herbicide, dicamba alone, glyphosate alone, or dicamba plus glyphosate. Factor B consisted of either no Group 15 residual herbicide, acetochlor, or S-metolachlor. In the 2,4-D- tolerant cotton …

Ammonium Chemotaxis In Chlamydomonas Reinhardtii, Gabela Nelson

LSU Doctoral Dissertations

Analysis of ammonium chemotaxis in Chlamydomonas reinhardtii is largely hindered, compared to that of phototaxis, despite equal importance on flagellated microalgal physiology. A major contribution of this shortfall is the lack of proper assay method. We developed a simple Petri dish assay method in which light is homogenously exposed while patterns of the cellular migration are tracked with a function of time. Using the method, new findings were revealed. First, this research presented that a strain lacking the eyespot organelle required for light gradient-sensing exhibits similar chemotactic behavior compared to a wild-type strain, suggesting Chlamydomonas sense an ammonium gradient not …

Spatial Mapping Of The Benthic Community And How It Is Used To Research Effects Of Dredging In Louisiana's Lake Borgne., Meghan Johnson

LSU Master's Theses

Benthic communities are vitally important for healthy aquatic ecosystems across Louisiana’s coast. Specifically in Lake Borgne, ecologically important species of fish like the Gulf Sturgeon (Acipenser oxyrinchus desotoi) rely on benthic macrofauna as their main food source. The purpose of this study was to determine the spatial landscape of biodiversity and abundance of the benthic macrofauna community in Lake Borgne. Environmental conditions played a key role in community structure during the study period (fall 2021 through summer 2023) with a major drought occurring in 2023. In 2023, the decline in the abundance of most benthic invertebrates and in …

A Novel Goat Model To Characterize Male Fertility Following Paternal Cannabidiol Exposure, Ashlyn N. Brewer, Kenneth R. Bondioli, Cathleen Williams, Clare Scully

LSU Master's Theses

Despite the increasing use of cannabidiol, both for medical and social purposes, the effect of cannabidiol on male fertility is poorly understood. Previous studies have been carried out in rodent models, but a large animal model does not exist at this time. This experiment proposes chronic cannabidiol (CBD) exposure using a goat model to understand the impact CBD has on male reproductive performance. The purpose of this project is to determine if daily exposure to CBD in male goats would impact reproductive parameters such as sperm quality and testosterone levels.

Two studies were conducted to determine the effects of CBD …

Addition And Subtraction: Coral Reproduction And Disease In A Changing Ocean, Ashley Rossin

LSU Doctoral Dissertations

Marine diseases are changing the landscapes of coral reefs particularly throughout the Western Atlantic. Stony coral tissue loss disease (SCTLD) swept through this region impacting at least 22 stony coral species. White plague (WP) is a more ephemeral disease, but still has a significant impact on coral reef health and perseverance, especially under a changing ocean. While these impacts are seen on the reef-scale, we can zoom into the tissue-level to identify disease markers for both diseases and identify their differences. This has ramifications for disease intervention, as well as mitigation strategies. Despite continuous disease outbreaks, healthy corals persist and …

The Use Of Duddingtonia Flagrans Aged In Mineral For Gastrointestinal Parasitic Nematode Control In Small Ruminants, Elisa M. Preston

LSU Master's Theses

Gastrointestinal nematodes (GIN) are a major constraint to small ruminant health and production throughout the world. Haemonchus contortus commonly known as the “barber pole worm” is a major concern for producers and veterinarians because of the severe anemia, and other clinical symptoms these worms cause. For decades, anthelmintics have been used to control the GIN burden small ruminants face. Katahdin (n=36) and Hampshire sheep (n=12) were used in a randomized block design experiment over a 30-day period. The objective of this study was to evaluate the effectiveness of Duddingtonia flagrans spores, the active ingredient in a commercial product, Bioworma® (International …

Prescribed Fire Effects On Microbial Communities And Functions In Managed Ecosystems, Viet Dao

LSU Doctoral Dissertations

Microbes (both fungi and bacteria) serve important ecosystem functional roles in nutrient cycling and decomposition, which affect ecosystem response following disturbances such as prescribed fire. A multitude of abiotic and biotic factors influence microbial community compositions, which then drive microbial ecosystem functions. The factors driving microbial communities further change due to fire disturbances and progression with time. Although prescribed fire is commonly used as a technique for ecosystem management, the effects of fire on microbial communities or their functions are simply understudied. Ecosystem management decisions tend to focus on plant and ecosystem post-fire responses. Thus, incorporation of fire effects on …

Halosulfuron Plus Prosulfuron And Propanil Interactions For Weed Control In Louisiana Rice Production, John A. Williams

LSU Master's Theses

A greenhouse study was conducted on November 18, and December 2, 2020 at Louisiana State University in Baton Rouge, Louisiana to evaluate the interaction between a pre-packaged mixture of halosulfuron plus prosulfuron mixed with propanil for alligatorweed control. Antagonism occurred when halosulfuron plus prosulfuron at 55 g ha-1 was mixed with propanil at 2,242 g ha-1 at all evaluation dates and antagonism was also observed with halosulfuron plus prosulfuron at 83 g ha-1 mixed with propanil at 2,242 g ha-1 at all evaluation dates except 14 DAT with observed controls of 69 to 77% compared with expected controls of 94 …

The Ecological Responses To Hydroperiod Of Wetland Plant Species Determined By Manipulated Soil Surface Elevation (Marsh Organs), Brandon Wolff

LSU Master's Theses

As sea level rise, subsidence, and abandonment of natural deltaic processes due to a highly engineered Mississippi River continue to threaten Louisiana’s coastal wetlands, the need for a system-wide understanding of natural wetland land-building and preservation processes has never been greater. A key component of any wetland is the ever-changing water environment that periodically floods and dries the marsh platforms. The flooding depth, duration, and frequency, known as the hydroperiod, along with salinity and soil fertility are key determining factors of vegetation and marsh types at a particular location. Different types of vegetation will have different growth characteristics such as …

Machine Learning-Based Soybean Yield Prediction And Optimizing Lidar-Mounted Uav Efficiency, Leticia Santos

LSU Master's Theses

The first chapter of this thesis explores the predictive capabilities of random forests algorithm on datasets obtained from field plot experiments on crop management systems in soybean. Furthermore, the chapter presents a complementary analysis of model performance according to dataset sizes and two techniques on how to impute and deal with missing data. Random forests are being compared with standard statistical techniques such as linear regression on a well-structured, information-rich agronomic experiment. The key findings of this chapter includes the best hyperparameters adjustment and the identification of the dataset threshold for optimal algorithms performance. The second chapter has a research …

Diving At High Altitude: O2 Transport And Utilization In The Ruddy Duck And Torrent Duck In The Andes, Kevin G. Mccracken, Graham R. Scott, Luis Alza, Andrea Astie, Ciska Bakkeren, Emil Bautista, Mariana Bulgarella, Rebecca Cheek G. Cheek, Beverly A. Chua, Neal J. Dawson, Alexis Diaz, Catherine M. Ivy, Peter B. Frappell, Cecilia Kopuchian, Sabine L. Laguë, John N. Maina, Violeta Muñoz-Fuentes, Elizabeth R. Schell, Matthew M. Smith, Ryan J. Sprenger, Pablo L. Tubaro, Elizabeth R. Schell, Matthew M. Smith, Ryan J. Sprenger, Pablo L. Tubaro, Thomas Valqui, Roy E. Weber, Daniela Wilner, Robert E. Wilson, Julia M. York, William K. Milsom

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

Hypoxia and cold temperatures create unique physiological challenges for high-altitude organisms that can vary depending on lifestyle. While nearly all studies of air-breathing animals at high altitude are from terrestrial species, species that breath-hold dive underwater at high altitude encounter a very different set of selective pressures influencing their phenotype. The goal of this publication is to highlight the changes in O2 transport and utilization in high-altitude diving birds relative to divers at sea level, and the extent to which these changes are qualitatively distinct from phenotypic changes in non-diving species at high altitude. For example, while high capacities for …

Louisiana Agriculture Magazine, Winter 2024, Lsu Agcenter

Louisiana Agriculture

Research at the LSU AgCenter extends well beyond the farm gate. Across 150 acres at the Hammond Research Station, experts in landscape horticulture test the best ways to grow ornamental plants and trees. In Baton Rouge, researchers study how to protect homes in the path of a hurricane. Across the state the AgCenter Healthy Communities team works to empower food pantries and improve sidewalks and other pedestrian infrastructure in rural areas.

This issue of Louisiana Agriculture focuses on these topics along with new research on soil health and high-tech delivery systems for sugarcane ripening agents. Other articles focus on the …