Digital Commons Network^™

Climate And Plant Trait Strategies Determine Tree Carbon Allocation To Leaves And Mediate Future Forest Productivity, Anna T. Trugman, Leander D.L. Anderegg, Brett T. Wolfe, Benjamin Birami, Nadine K. Ruehr, Matteo Detto, Megan K. Bartlett, William R.L. Anderegg

Faculty Publications

Forest leaf area has enormous leverage on the carbon cycle because it mediates both forest productivity and resilience to climate extremes. Despite widespread evidence that trees are capable of adjusting to changes in environment across both space and time through modifying carbon allocation to leaves, many vegetation models use fixed carbon allocation schemes independent of environment, which introduces large uncertainties into predictions of future forest responses to atmospheric CO2 fertilization and anthropogenic climate change. Here, we develop an optimization-based model, whereby tree carbon allocation to leaves is an emergent property of environment and plant hydraulic traits. Using a combination of …

Wetland Biomass And Productivity In Coastal Louisiana: Base Line Data (1976-2015) And Knowledge Gaps For The Development Of Spatially Explicit Models For Ecosystem Restoration And Rehabilitation Initiatives, Victor H. Rivera-Monroy, Courtney Elliton, Siddhartha Narra, Ehab Meselhe, Xiaochen Zhao, Eric White, Charles E. Sasser, Jenneke M. Visser, Xuelian Meng, Hongqing Wang, Zuo Xue, Fernando Jaramillo

Faculty Publications

Coastal Louisiana hosts 37% of the coastal wetland area in the conterminous US, including one of the deltaic coastal regions more susceptible to the synergy of human and natural impacts causing wetland loss. As a result of the construction of flood protection infrastructure, dredging of channels across wetlands for oil/gas exploration and maritime transport activities, coastal Louisiana has lost approximately 4900 km2 of wetland area since the early 1930s. Despite the economic relevance of both wetland biomass and net primary productivity (NPP) as ecosystem services, there is a lack of vegetation simulation models to forecast the trends of those functional …

Crafting Identity: Language, Gender, And The Internet In The Arab World, Connor C. Rouillier

Honors Capstones

No abstract provided.

Social Determinants Of Health Inequality: Predictors Of Hiv Transmission Among African Americans In The Deep South, Kayla Allison

LSU Doctoral Dissertations

HIV/AIDS has become an epidemic in Black communities in the Deep South, which poses a major public health crisis. Unfortunately, the lack of attention from health officials has resulted in African Americans experiencing the greatest burden of the disease as compared to any other racial/ethnic group. Thus, this cross-sectional, correlational study examined predictors of HIV transmission with an emphasis on the course of the disease among African Americans in the Deep South region of the United States given the legacy of slavery, historical racism, and plight of African Americans in this geographical area. The institution of slavery was not isolated …

Deciphering Public Transit Ridership In Baton Rouge: Spatial Disaggregation Approaches, Xuan Kuai

LSU Doctoral Dissertations

Background: Surveys across the U.S. reveal that commuters driving personal vehicles spend a significant amount of time in traffic, while public transit, as an efficient commuting mode, has been largely underutilized.

Purpose: What causes a low public transit ridership? How could public transit ridership be explained by demographic, socio-economic and spatial characteristics of neighborhood? This study answers these questions by deciphering the relationships between public transit ridership and various factors in a medium-size city in southern U.S. – Baton Rouge, Louisiana.

Methods: Non-spatial and spatial data in a larger areal unit (e.g., block group) are used to infer demographic, socio-economic …

The Importance Of Landscape Position Information And Elevation Uncertainty For Barrier Island Habitat Mapping And Modeling, Nicholas Matthew Enwright

LSU Doctoral Dissertations

Barrier islands provide important ecosystem services, including storm protection and erosion control to the mainland, habitat for fish and wildlife, and tourism. As a result, natural resource managers are concerned with monitoring changes to these islands and modeling future states of these environments. Landscape position, such as elevation and distance from shore, influences habitat coverage on barrier islands by regulating exposure to abiotic factors, including waves, tides, and salt spray. Geographers commonly use aerial topographic lidar data for extracting landscape position information. However, researchers rarely consider lidar elevation uncertainty when using automated processes for extracting elevation-dependent habitats from lidar data. …

Nonmonotonic Postdeglacial Relative Sea Level Changes At The Aftermath Of Marinoan (635 Ma) Snowball Earth Meltdown, Yoshiya Irie, Masao Nakada, Jun'ichi Okuno, Huiming Bao

Faculty Publications

© 2019. American Geophysical Union. All Rights Reserved. Marinoan snowball Earth offers us a set of sedimentary and geochemical records for exploring glacial isostatic adjustment (GIA) associated with one of the most severe glaciations in Earth history. An accurate prediction of GIA-based relative sea level (RSL) change associated with a snowball Earth meltdown will help to explore sedimentary records for RSL changes and to place independent constraints on mantle viscosity and on the durations of syndeglaciation (Td) and cap carbonate deposition. Here we mainly examine postdeglacial RSL change characterized by an RSL drop and a resumed transgression inferred from the …

Flood Protection Ecosystem Services In The Coast Of Puerto Rico: Associations Between Extreme Weather, Flood Hazard Mitigation And Gastrointestinal Illness, R. De Jesus Crespo, J. Wu, M. Myer, S. Yee, R. Fulford

Faculty Publications

No abstract provided.

Bluebills And Bayou Bivalves: Hurricane-Driven Trophic Cascades Affect Wintering Abundance Of Lesser Scaup In Louisiana, Clay M. Stroud, Claire E. Caputo, Michael A. Poirrier, Larry A. Reynolds, Kevin M. Ringelman

Faculty Publications

The estuaries of coastal Louisiana overwinter a continentally significant proportion of Lesser Scaup (Aythya affinis; colloquially, “bluebills”), a migratory bird species of conservation concern since population declines began in the 1980s. Thirty-eight years of aerial waterfowl surveys of Lake Pontchartrain—an oligohaline estuarine lagoon in southeast Louisiana—show that scaup abundance fluctuates between 0 and 1,194,907 birds, though the mechanisms driving this variation are unknown. Previous studies have shown that scaup feed primarily on mollusks, and so changes in the benthic prey community have the potential to strongly influence scaup dynamics on the Lake. Benthic communities are in turn shaped by both …

Climatology And Trends In Hourly Precipitation For The Southeast United States, Vincent M. Brown, Barry D. Keim, Alan W. Black

Faculty Publications

This research introduces a climatology of hourly precipitation characteristics, investigates trends in precipitation hours (PH) and hourly accumulation, and uses four different time series to determine if precipitation intensity is changing across the southeastern United States from 1960 to 2017. Results indicate hourly intensity significantly increased at 44% (22/50) of the stations, accompanied by an increase in average hourly accumulation at 40% of the sites analyzed (20/50). The average duration of precipitation events decreased at 82% (41/50) of the stations. However, the frequency of 90th percentile hourly events and events above station-specific average hourly totals did not show a broad …

Investigation Of Spectral Variation Of Pine Needles As An Indicator Of Arsenic Content In Soils, Ji Hye Shin, Jaehyung Yu, Lei Wang, Jieun Kim, Sang Mo Koh

Faculty Publications

The spectral response to arsenic (As) stress of pine needles (Pinus densiflora Siebold and Zucc.) from an abandoned lead (Pb)–zinc (Zn) mine was investigated based on chemical and spectroscopic analyses. The correlation analysis between the content of As in needle samples and that of soils and spectral parameters of the needle samples were conducted. The results showed very high correlation between As content in pine needles and soils. The major spectral response of pine needles to the As stress were characterized by the increase in the green and red color reflectance, the decrease in the first derivatives at 1648 nm, …

Nonmonotonic Postdeglacial Relative Sea Level Changes At The Aftermath Of Marinoan (635 Ma) Snowball Earth Meltdown, Yoshiya Irie, Masao Nakada, Jun'ichi Okuno, Huiming Bao

Faculty Publications

© 2019. American Geophysical Union. All Rights Reserved. Marinoan snowball Earth offers us a set of sedimentary and geochemical records for exploring glacial isostatic adjustment (GIA) associated with one of the most severe glaciations in Earth history. An accurate prediction of GIA-based relative sea level (RSL) change associated with a snowball Earth meltdown will help to explore sedimentary records for RSL changes and to place independent constraints on mantle viscosity and on the durations of syndeglaciation (Td) and cap carbonate deposition. Here we mainly examine postdeglacial RSL change characterized by an RSL drop and a resumed transgression inferred from the …

Augmented Reality Enhancing The Inspections Of Transportation Infrastructure: Research, Education, And Industry Implementation, Fernando Moreu, Chris Lippitt, Dilendra Maharjan, Marlon Aguero, Xinxing Yuan

Publications

Transportation infrastructure needs continuous monitoring that is conducted by field inspectors regularly in the field. Currently, infrastructure inspectors climb, measure, and photograph structures annually to inform repair needs and prioritize decisions. In order to promote and accelerate early learner's expertise in decision-making capabilities during infrastructure inspections, this research project developed various software applications using augmented reality (AR) as an inspection tool for bridges and bridge management, more specifically. By objectively quantifying infrastructure field inspections, inspectors can make more accurate field assessments and managers can make better-informed decisions. This project collaborated with stakeholders, national laboratories, DOT agencies such as NCHRP and …

Scale Effects On Land Loss Modeling In The Mississippi River Delta, Nina S.-N. Lam, Heng Cai, Lei Zou, Kam-Biu Liu

Faculty Publications

No abstract provided.

Characterization Of Bunyamwera, Batai, And Ngari Viruses: Unrecognized Arboviruses Of One Health Importance In Rwanda, Marie Fausta Dutuze

LSU Doctoral Dissertations

Bunyamwera (BUNV), Batai (BATV), and Ngari (NRIV) are mosquito-borne viruses (Genus: Orthobunyavirus, Family: Peribunyaviridae, Order: Bunyavirales). They have an RNA tripartite genome consisting of small (S), medium (M), and large (L) segments. NRIV is a natural reassortant of BUNV and BATV, with the genome: S_BUNV, M_BATV, L_BUNV. All three viruses have been associated with disease of varying severity in domestic ruminants and humans. In livestock, infection with these viruses is associated with abortions, while humans may present a mild febrile illness or severe disease such as hemorrhagic fever or meningoencephalitis. In East Africa, …

Agricultural Education Teachers' Perceptions And Use Of Environmental Education In Louisiana Schools, Olivia M. Soler

LSU Master's Theses

The purpose of this study was to describe the status of environmental education (EE) in Louisiana high school agriculture classrooms. A census of Louisiana Agriscience Teacher Association (LATA) members was conducted to understand their perceptions, attitudes, and barriers regarding EE implementation. Icek Ajzen’s Theory of Planned Behavior was utilized as the theoretical framework. Data were collected through an online survey research method and analyzed using descriptive statistics. Results suggest that most LATA members incorporate EE into their curriculum relatively sparingly, perceive EE to be beneficial for students, and are in need of funding to incorporate EE into their curriculum as …

Improving The Transferability Of Suspended Solid Estimation In Wetland And Deltaic Waters With An Empirical Hyperspectral Approach, Daniel Jensen, Marc Simard, Kyle Cavanaugh, Yongwei Sheng, Cédric G. Fichot, Tamlin Pavelsky, Robert Twilley

Faculty Publications

The deposition of suspended sediment is an important process that helps wetlands accrete surface material and maintain elevation in the face of sea level rise. Optical remote sensing is often employed to map total suspended solids (TSS), though algorithms typically have limited transferability in space and time due to variability in water constituent compositions, mixtures, and inherent optical properties. This study used in situ spectral reflectances and their first derivatives to compare empirical algorithms for estimating TSS using hyperspectral and multispectral data. These algorithms were applied to imagery collected by NASA’s Airborne Visible/Infrared Imaging Spectrometer-Next Generation (AVIRIS-NG) over coastal Louisiana, …

Temporal And Spatial Dynamics Of Competitive Parapatry In Chewing Lice, Mark S. Hafner

Faculty Publications

We synthesize observations from 1979 to 2016 of a contact zone involving two subspecies of pocket gophers (Thomomys bottae connectens and T. b. opulentus) and their respective chewing lice (Geomydoecus aurei and G. centralis) along the Rio Grande Valley in New Mexico, U.S.A., to test predictions about the dynamics of the zone. Historically, the natural flood cycle of the Rio Grande prevented contact between the two subspecies of pocket gophers. Flood control measures completed in the 1930s permitted contact, thus establishing the hybrid zone between the pocket gophers and the contact zone between their lice (without hybridization). Since that time, …

Exploring The Link Between Students’ Usage Of Aleks And Their Performance On State Benchmark Assessments In Mathematics, Verna Marie Richard

LSU Doctoral Dissertations

The purpose of this mixed methods study was to investigate relationships between students’ ALEKS usage, teachers’ implementation of ALEKS, and student performance on the 2017 – 2018 LEAP 2025 mathematics assessment. The quantitative portion of the study involved district-level analyses and teacher-level analyses that explored relationships between students’ ALEKS usage and LEAP performance. The qualitative portion of the study took into consideration previous research findings that have reported associations between program implementation and student achievement. This portion of the study included thematic analyses that examined the following relationships: ALEKS implementation in relation to teacher groups (i.e., RtI 8, Math 8, …

The Religion Of Policing: Race, Riots, And The Killing Of Alton Sterling, Landon Jay Douglas

LSU Doctoral Dissertations

Deadly force encounters with black people and law enforcement officials are far too numerous and encounters that result in the death of civilians do not always result in disciplinary actions against officers, many of whom are white. The high-profile killings of black people in America require an in-depth analysis of race, policing, and the origins of tactics used by law enforcement against black people, which is not merely data-driven, but also theory driven. In trying to understand the disparate treatment experienced by black people at the hands of law enforcement officials, and the extent to which many Americans, mostly white …

Hourly Precipitation Climatology Of The Southeast United States, Vincent Brown

LSU Doctoral Dissertations

Precipitation changes are one of the most important potential outcomes of a warming climate because of how essential it is to society and ecosystems. Sub-daily precipitation time series provide more information on precipitation characteristics, particularly frequency, intensity, and duration compared to daily data. In a series of four peer-reviewed manuscripts, this research investigates sub-daily precipitation characteristics from a climatological perspective. The first study introduces a climatology of hourly precipitation for four first-order weather stations across Louisiana, explores possible changes in the hourly precipitation distribution, and links winter Gulf of Mexico sea surface temperatures to the frequency of hours with precipitation. …

Habitat Preference Modulates Transoceanic Dispersal In A Terrestrial Vertebrate, Mozes P.K. Blom, Nicholas J. Matzke, Jason G. Bragg, Evy Arida, Christopher C. Austin, Adam R. Backlin, Miguel A. Carretero, Robert N. Fisher, Frank Glaw, Stacie A. Hathaway, Djoko T. Iskandar, Jimmy A. Mcguire, Benjamin R. Karin, Sean B. Reilly, Eric N. Rittmeyer, Sara Rocha, Mickaël Sanchez, Alexander L. Stubbs, Miguel Vences, Craig Moritz

Faculty Publications

© 2019 The Author(s) Published by the Royal Society. All rights reserved. The importance of long-distance dispersal (LDD) in shaping geographical distributions has been debated since the nineteenth century. In terrestrial vertebrates, LDD events across large water bodies are considered highly improbable, but organismal traits affecting dispersal capacity are generally not taken into account. Here, we focus on a recent lizard radiation and combine a summary-coalescent species tree based on 1225 exons with a probabilistic model that links dispersal capacity to an evolving trait, to investigate whether ecological specialization has influenced the probability of trans-oceanic dispersal. Cryptoblepharus species that occur …

Mapping Soil Moisture From Remotely Sensed And In-Situ Data With Statistical Methods, Yaping Xu

LSU Doctoral Dissertations

Soil moisture is an important factor for accurate prediction of agricultural productivity and rainfall runoff with hydrological models. Remote sensing satellites such as Soil Moisture Active Passive (SMAP) offer synoptic views of soil moisture distribution at a regional-to-global scale. To use the soil moisture product from these satellites, however, requires a downscaling of the data from an usually large instantaneous field of view (i.e. 36 km) to the watershed analysis scales ranging from 30 m to 1 km. In addition, validation of the soil moisture products using the ground station observations without an upscaling treatment would lead to cross-level fallacy. …

Sediment Identification Using Machine Learning Classifiers In A Mixed-Texture Dredge Pit Of Louisiana Shelf For Coastal Restoration, Haoran Liu, Kehui Xu, Bin Li, Ya Han, Guandong Li

Faculty Publications

No abstract provided.

Contrasting Latitudinal Gradients Of Body Size In Helminth Parasites And Their Hosts, Tad Dallas, Alyssa Lois M. Gehman, A. Alonso Aguirre, Sarah A. Budischak, John M. Drake, Maxwell J. Farrell, Ria Ghai, Shan Huang, Ignacio Morales-Castilla

Faculty Publications

© 2019 John Wiley & Sons Ltd Aim: We examined body size scaling relationships for two developmental life stages of parasitic helminths (egg and adult) separately in relationship to latitude (i.e. Bergmann's rule), temperature and temperature seasonality. Given that helminth eggs experience environmental conditions more directly, whereas adults live inside infected host individuals, we predict stronger environmentally driven gradients of body size for eggs than for adults. Location: Global. Time period: Present day. Major taxa studied: Parasitic helminths. Methods: We compiled egg size and adult body size data (both minimum and maximum) for 265 parasitic helminth species from the literature, …

Predicting Climate Types For The Continental United States Using Unsupervised Clustering Techniques, D. Sathiaraj, X. Huang, J. Chen

Faculty Publications

The problem of clustering climate data observation sites and grouping them by their climate types is considered. Machine learning–based clustering algorithms are used in analyzing climate data time series from more than 3,000 climate observation sites in the United States, with the objective of classifying climate type for regions across the United States. Understanding the climate type of a region has applications in public health, environment, actuarial science, insurance, agriculture, and engineering. In this study, daily climate data measurements for temperature and precipitation from the time period 1946–2015 have been used. The daily data observations were grouped into three derived …

The Use Of Geospatial Modeling And Novel Diagnostics To Detect And Map Risk Factors Of Soil-Transmitted Helminths In Feira De Santana, Brazil, Ryan Harry Avery

LSU Doctoral Dissertations

Soil-transmitted helminth (STH) infections impact billions of people worldwide. The traditional STH control approach is a morbidity control strategy implementing mass drug administration (MDA) programs targeting school-aged children (SAC). In Brazil, this control strategy has decreased STH prevalence to less than 20% in most of the country and providing an opportunity to transition from the morbidity control program and towards a surveillance and response system geared towards STH elimination. Surveillance and response systems geared towards elimination require the implementation higher accuracy diagnostics to detect infection in low-transmission communities, surveillance of entire households, high-resolution modeling at the household-habitat scale, and targeted …

Designing And Composing For Interdependent Collaborative Performance With Physics-Based Virtual Instruments, Eric Sheffield

LSU Doctoral Dissertations

Interdependent collaboration is a system of live musical performance in which performers can directly manipulate each other’s musical outcomes. While most collaborative musical systems implement electronic communication channels between players that allow for parameter mappings, remote transmissions of actions and intentions, or exchanges of musical fragments, they interrupt the energy continuum between gesture and sound, breaking our cognitive representation of gesture to sound dynamics.

Physics-based virtual instruments allow for acoustically and physically plausible behaviors that are related to (and can be extended beyond) our experience of the physical world. They inherently maintain and respect a representation of the gesture to …

A Case-Study Approach To Investigate Transmission, Co-Infection, And Clinical Sequelae During Epidemics Of Dengue And Ebola Virus Disease, Jennifer Elizabeth Giovanni

LSU Doctoral Dissertations

From within their ecologic niches, zoonotic viruses emerge from animal reservoirs into the edges and centers of human habitation to exploit opportunities for unabated transmission within immunologically–naïve populations. Our understanding of where, in whom, and how these viruses emerge is under direct challenge, driving the evolution of modern infectious disease epidemiology within a rapidly-connected global community. The studies presented herein are based on analyses of both aggregate and case-level data, which, we argue, provide unique insight into the complexities of transmission, co-infection, and clinical sequelae occurring within, and arising from, epidemics of emerging zoonotic viruses. In Chapter II, we investigate …

Global-Mindedness In National Geographic Certified Educators, Amy Pan

LSU Doctoral Dissertations

ABSTRACT

The purpose of this mixed methods study is to investigate the global-mindedness among National Geographic Certified Educators. The triangulation of data includes quantitative data, which is the Global-Mindedness Scale (Hett, 1993), and qualitative data, which is the questionnaire, and sample lesson plans. The survey results were based on 485 participants, with 286 National Geographic Certified Educators and 199 non-National Geographic Certified Educators. The survey was conducted through Qualtrics© with privacy protection and the Statistical Package of Social Science (SPSS) was used for a two-tailed independent sample t-test and Repeated Measures ANOVA to analyze the data. Google Forms was …