Physical Sciences and Mathematics Commons^™

Winter Survival And Physiology Of Contrasting Fall Dormancy Selections Of Alfalfa, J J. Volenec, S M. Cunningham, L R. Teuber

IGC Proceedings (1993-2023)

Our objective was to determine the physiological changes that accompany selection from within a germplasm for contrasting fall dormancy reaction. Selection for greater fall dormancy improved winter survival of CUF 101 from 1 to 93%. The more fall dormant CUF 101 had higher sugar concentrations in buds and roots. Roots of the more fall dormant CUF 101 also contained higher soluble protein concentrations when compared to the other CUF 101 germplasms. Root protein extracts obtained in Dec. from the more fall dormant CUF 101 contained at least one polypeptide not found in protein extracts of the other CUF 101 germplasms. …

Root Nitrogen Cycling And Alfalfa Stress Tolerance, J J. Volenec, B C. Joern, L D. Barber, S M. Cunningham, A Ourry

IGC Proceedings (1993-2023)

Our hypothesis is that certain root N pools are utilized preferentially during the early shoot regrowth. Our objective was to determine the relative contribution of crown N, root N, and specific root N pools to shoot regrowth after defoliation. We used 15N to follow N into and out of crowns, roots, and specific root N pools, to regrowing shoots after defoliation. The low molecular weight N pool (amino acids, inorganic N,...) acquired 15N rapidly within 2 d of N application. Movement of 15N into the protein-N and insoluble-N pools was delayed initially, but continued until 8 d after N application. …

Phyllochron Development In Cool-Season Forage Grasses, A B. Frank, J D. Berdahl, J F. Karn

IGC Proceedings (1993-2023)

The purpose of this study was to evaluate the relationship between grass leaf insertion rate and accumulated growing degree-days, and determine the phyllochron for five perennial forage grass species and two cultivars of each species. Species field seeded in solid stands were crested wheatgrass [Agropyron desertorum (Fisch. ex. Link) Schult.], intermediate wheatgrass, [Thinopyrum intermedium Barkw. & Dewey:Syn:A. intermedium (Host) Brauv], western wheatgrass [Pascopyrum smithii (Rybd) L ve], green needlegrass (Stipa viridula Trin.), and smooth bromegrass (Bromus inermis Leyss). Species phyllochron differences ranged from 77 GDD for Mandan 404 smooth bromegrass to 114 GDD for Lodorm …

Response To Drought Of White Clover Lines Selected For Different Stolon Morphologies, H D. Karsten, J R. Caradus, D R. Woodfield

IGC Proceedings (1993-2023)

White clover (Trifolium repens L.) lines were selected from within large and small-leaved cultivars of Grasslands Kopu and Grasslands Tahora, respectively, for long or short internodes, and for high or low branching frequency from plants grown in sun and shade (50% full sunlight). Lines were compared for drought tolerance in a perennial ryegrass (Lolium perenne L.) sward in boxes. Prior to imposing drought branching frequency selections did not differ in branching frequency, although the low branching frequency selection had a higher percentage of rooted nodes. After an imposed drought treatment sun-selected lines grew better than shade-selected lines relative …

Kentucky Bluegrass Floral Induction And Cultivar Response To Mechanical Removal Of Harvest Residue, G A. Murray, J B. Swensen

IGC Proceedings (1993-2023)

Open-field burning of post-harvest residue from Kentucky bluegrass (Poa pratensis L.) seed fields is being phased out in Washington, USA and may be banned in Idaho. Burning encourages early fall regrowth and timely completion of fall floral induction. Cultivars have different floral induction requirements and respond differently to mechanical residue removal. Our objective was to determine if length of fall floral induction requirement was related to seed yield when post-harvest residue was removed by crewcut vacuum sweeping. Floral induction requirements were not related to first-or second-year seed yields. Third-year seed yield of cultivars with long floral induction requirements declined …

The Influence Of Intensity Of Tree Thinning On The Redistribution Of Soil Water In Southern African Mopani Veld, G N. Smit, N F.G. Rethman, A Moore, A Le Roux, J S. Swart

IGC Proceedings (1993-2023)

The investigation was conducted on a densely wooded area in the Mopani veld of South Africa. Six plots were subjected to different intensities of tree thinning, ranging from a totally cleared plot (0 %) to plots thinned to the equivalent of 10%, 20%, 35%, 50% and 75% of the leaf biomass of a control plot (100%). Soil water measurements were taken at six different depths to a depth of 825 mm. The infiltration of rain water and redistribution within the soil profile exhibited marked differences between experimental plots. The soil water was predominantly held at a very shallow depth ( …

Relationship Of Visual And Quantitative Methods Of Grass Sward Development, R B. Mitchell, L E. Moser, K J. Moore

IGC Proceedings (1993-2023)

The objective of this study was to determine the relationship between visual and quantitative estimates of the morphological development of perennial grass swards. Pure stands of intermediate wheatgrass [Thinopyrum intermedium (Host) Barkw. & D.R. Dewey] and switchgrass (Panicum virgatum L.) were hand-clipped to ground level at 2-wk intervals in 1991 at Mead, NE, morphologically classified as mean stage count (MSC), and visually estimated for sward development. Visual estimations of sward development for both species were representative of quantitative measurements during vegetative growth. However, as sward development advanced to the elongation and heading stages, visual methods over-estimated the population …

Morphological Development Rates Of Perennial Forage Grasses, R B. Mitchell, L E. Moser, K J. Moore, D D. Redfearn

IGC Proceedings (1993-2023)

The objective of this study was to determine the rate of change in the morphological development of switchgrass (Panicum virgatum L.) and big bluestem (Andropogon gerardii Vitman). Pure stands of each species were sampled at weekly intervals in 1990 and 1991 at Mead, NE, and morphologically classified as mean stage count (MSC) and mean stage weight (MSW). Linear day of the year equations accounted for 94% of the variation in switchgrass MSC and MSW. Switchgrass MSC and MSW increased at an average rate of 0.0204 and 0.0234 units per day, respectively. Linear day of the year equations accounted …

Fertilizer Nitrogen And Morphogenetic Response In Avena Sativa And Lolium Multiflorum, F Lattanzi, M A. Marino, A Mazzanti

IGC Proceedings (1993-2023)

A field experiment was carried out at the EEA Balcarce, INTA, Argentina (37° 45’LS, 58° 18’LW) to determine whether Leaf Appearance Rate (LAR) was affected by N fertilization in Italian ryegrass (Lolium multiflorum Lam.) and forage oats (Avena sativa). N treatments (0, 50, 100, 150, 200 and 250 kg N ha-1) were applied in winter 1995, after a defoliation. Subsequently, number of leaves per tiller was determined on 45 labelled tillers in each treatment twice a week. LAR was calculated as the slope of the linear regression of number of leaves on thermal time (air temperature, base …

Allocation Of Carbon-14 To Roots Of Different Ages In Perennial Ryegrass (Lolium Perenne L.), C Matthew, W D. Kemball

IGC Proceedings (1993-2023)

The objective of this study was to provide information on how current photosynthate allocated to the root system in perennial ryegrass (Lolium perenne L.) is distributed among individual roots at differing nodal positions. Mature single ryegrass tillers were transplanted in September 1993 to glass house pots and three months later four of the plants were supplied with 14CO2. Individual roots from these radioactively-labeled plants were identified according to their nodal position on the tiller axis and amount of radiocarbon in each root quantified for root tip segments and for the remainder of the root axis. Similar plants were destructively …

The Analysis Of Dynamic Interaction In Legume Binary Mixture Under Controlled Conditions Of Irrigation And Clipping, M S. Vrahnakis, B Noitsakis, Z Koukoura

IGC Proceedings (1993-2023)

The objective of this study was to analyse the type of interference that occurred between the annual legume species, purple clover (Trifolium purpureum L.) and narrow leaved crimson clover (Trifolium angustifolium Loisel. ), growing in mixed conditions under two different watering regimes and two different clipping treatments. A replacement series experiment was conducted in pots placed in the field. The above ground biomass (gr/plant) were measured. The recently proposed Inverse Linear Model was implied in order to analyse the competitive interaction between the above species. The results suggest that Tr. purpureum was the superior competitor to Tr. angustifolium …

Estimating Crustal Thickness In Northwest Louisiana Using The Receiver Function Method, Delton Samuel

LSU Master's Theses

I aim to constrain the crustal thickness of the Sabine Block in the Sabine Uplift region of northwest Louisiana, using the frequency domain receiver function deconvolution technique followed by H-κ stacking. The passive margin on the southern edge of the North American continent experienced an active tectonic history, including the spreading events that led to the formation of the Gulf of Mexico. A previous study proposed the Sabine Block is a residual fragment of Proterozoic orogenic origin; however, its full extent and geometry are up for debate. It is now overlain by thick sedimentary sequences ranging from ~4-6 km deposited …

Visual Analytics In Explaining Neural Networks With Neuron Clustering, Gulsum Alicioglu, Bo Sun

College of Science & Mathematics Departmental Research

Deep learning (DL) models have achieved state-of-the-art performance in many domains. The interpretation of their working mechanisms and decision-making process is essential because of their complex structure and black-box nature, especially for sensitive domains such as healthcare. Visual analytics (VA) combined with DL methods have been widely used to discover data insights, but they often encounter visual clutter (VC) issues. This study presents a compact neural network (NN) view design to reduce the visual clutter in explaining the DL model components for domain experts and end users. We utilized clustering algorithms to group hidden neurons based on their activation similarities. …

Predicting The Potential Distribution Of Pseudococcus Longispinus (Targioni-Tozzetti) (Hemiptera: Pseudococcidae) In South Korea Using A Climex Model, Su Bin Kim, Soo-Jung Suh

Insecta Mundi

Pseudococcus longispinus (Targioni-Tozzetti) (Hemiptera: Pseudococcidae) is a widely-distributed pest that feeds on many economically important hosts, particularly tropical fruits and ornamentals. The potential distribution of this mealybug pest in South Korea remains a primary concern because of its high incidence of interceptions screened during inspection. Hence, this species prompted a modelling effort to assess its potential risk of introduction. Potential risk maps were developed for this pest with a CLIMEX model based on occurrence records under environmental data. The potential distribution of these pests in South Korea in the 2020s, 2050s and 2090s was projected based on the RCP 8.5 …

An Integrated Architecture For A Global Clean Energy Transition, Alice Kaswan

Journal of Interdisciplinary Perspectives and Scholarship

No abstract provided.

Changes In Reef Tourism’S Adaptive Capacity After Severe Climate Disturbances, Henry Bartelet, Michele Barnes, Lalu Bakti, Graeme S. Cumming

Quantitative Methods and Information Technology Faculty Publications

Knowledge about adaptive capacity and its determinants has increased significantly over the last decade. However, most research on adaptive capacity has been static, not considering how adaptive capacity might change over time, particularly after severe disturbances. We studied the adaptive capacity dynamics of Asian-Pacific reef tourism operators affected by coral bleaching and tropical cyclones compared with a control group with non-affected operators. We found that impacts from tropical cyclones were associated with frequent changes in adaptive capacity. Notably, we found a reduction in tangible attributes (assets and flexibility) of adaptive capacity, whereas intangible attributes (agency and social organization) increased. Our …

Reducibility Of Schrödinger Operators On Multilayer Graphs, Jorge Villalobos Alvarado

LSU Doctoral Dissertations

A local defect in an atomic structure can engender embedded eigenvalues when the associated Schrödinger operator is either block reducible or Fermi reducible, and having multilayer structures appears to be typically necessary for obtaining such types of reducibility. Discrete and quantum graph models are commonly used in this context as they often capture the relevant features of the physical system in consideration.

This dissertation lays out the framework for studying different types of multilayer discrete and quantum graphs that enjoy block or Fermi reducibility. Schrödinger operators with both electric and magnetic potentials are considered. We go on to construct a …

Finite Monodromy And Artin Representations, Emma Lien

LSU Doctoral Dissertations

Artin representations, which are complex representations of finite Galois groups, appear in many contexts in number theory. The Langlands program predicts that Galois representations like these should arise from automorphic representations and many examples of this correspondence have been found such as in the proof of Fermat's Last Theorem. This dissertation aims to make an analysis of explicitly computable examples of Artin representations from both sides of this correspondence. On the automorphic side, certain weight 1 modular forms have been shown to be related to Artin representations and an explicit analysis of their Fourier coefficients allows us to identify the …

Supply, Demand, And Fiscal Sustainability Of Outdoor Recreation In Utah, Jordan W. Smith, Chris Monz

Environment and Society Faculty Publications

Because Utah's outdoor recreation destinations are managed by several different federal and state agencies, there is no comprehensive and consistent information on the amount and types of outdoor recreation resources available within the state. Additionally, there has been no research to date on how state programs whose revenues are dependent on outdoor recreation activity, are likely to fare in the coming years. This report begins to address these limitations by: 1) compiling and synthesizing data that characterize the amount and location of outdoor recreation resources throughout the state; and 2) presenting the results of a suite of econometric forecasting models …

Structural, Spectroscopic, And Computational Insights From Canavanine-Bound And Two Catalytically Compromised Variants Of The Ethylene-Forming Enzyme, Shramana Chatterjee, Matthias Fellner, Joel A. Rankin, Midhun George Thomas, Simahudeen Bathir Jaber Sathik Rifayee, Christo Christov, Jian Hu, Robert P. Hausinger

Michigan Tech Publications, Part 2

The ethylene-forming enzyme (EFE) is an Fe(II), 2-oxoglutarate (2OG), and l-arginine (l-Arg)-dependent oxygenase that either forms ethylene and three CO2/bicarbonate from 2OG or couples the decarboxylation of 2OG to C5 hydroxylation of l-Arg. l-Arg binds with C5 toward the metal center, causing 2OG to change from monodentate to chelate metal interaction and OD1 to OD2 switch of D191 metal coordination. We applied anaerobic UV-visible spectroscopy, X-ray crystallography, and computational approaches to three EFE systems with high-resolution structures. The ineffective l-Arg analogue l-canavanine binds to the EFE with O5 pointing away from the metal center while promoting chelate formation by 2OG …

Assessing The Spatial Variability Of Soil Physical Properties Under A Corn Field In Kentucky, Usa, Sai Neela Kesumala

Scholars Week

Analyzing soil physical properties is crucial for advancing sustainable and precision agricultural practices in today's world. Sustainable agriculture emphasizes responsible resource utilization and preservation. Precision agriculture utilizes technology, data, and targeted decision-making to optimize resource usage and minimize environmental impacts. Assessing soil property variability aids in efficient input application, irrigation adjustment, nutrient runoff reduction, and fertilizer management. This approach prioritizes soil conservation, boosts sustainability, and supports long-term agricultural productivity. This study aimed to evaluate the spatial distribution of specific soil physical properties across the four border rows, central corn field area, and sod area. Seventy-two soil samples were collected from …

The Modular Generalized Springer Correspondence For The Symplectic Group, Joseph Dorta

LSU Doctoral Dissertations

The Modular Generalized Springer Correspondence (MGSC), as developed by Achar, Juteau, Henderson, and Riche, stands as a significant extension of the early groundwork laid by Lusztig's Springer Correspondence in characteristic zero which provided crucial insights into the representation theory of finite groups of Lie type. Building upon Lusztig's work, a generalized version of the Springer Correspondence was later formulated to encompass broader contexts.

In the realm of modular representation theory, Juteau's efforts gave rise to the Modular Springer Correspondence, offering a framework to explore the interplay between algebraic geometry and representation theory in positive characteristic. Achar, Juteau, Henderson, and Riche …

Exploration Of Characteristic Curve In Fox Float 3 Shock Dampers To Expedite Shock Damp Tuning., Joshua R. Moore

Honors College Theses

The shock absorber is an integral part of a vehicle suspension system and has a strong influence on its performance, especially in the case of motorsports. It is important to study the force versus velocity relationship, commonly known as the characteristic curve of the shock absorber both during compression and rebound. Vendor-supplied characteristics often reflect the behavior of the shock absorber in a particular setting. However, during the installation, the settings inside the shock absorber are adjusted to increase the human comfort level and performance of the vehicle. This may change the characteristic curve of the shock. The available data …

2024 April 4 - Tennessee Weekly Drought Summary, Tennessee Climate Office, East Tennessee State University

Tennessee Climate Office Weekly Drought Summaries

No abstract provided.

Non-Destructive Thickness Uniformity Measurement Of Photosensitive Gelatin Film, Clayton Halper

Physics Capstone Projects

Volume phase holographic gratings (VPHG’s) depend on dichromate gelatin of which uniform thickness is vital. The photosensitive nature of the film makes current thin film measurement devices not viable for production means. This project attempts to create a non-destructive measurement of photosensitive gelatin film used in VPHG production. Application of thin film interference at chosen wavelengths enable analysis of uniformity by comparison between the thin film inference patterns at different wavelengths. An initial proof of concept was established and a path towards a production ready device is outlined.

Globe-Lfmc 2.0, An Enhanced And Updated Dataset For Live Fuel Moisture Content Research, Marta Yebra, Gianluca Scortechini, Karine Adeline, Nursema Aktepe, Turkia Almoustafa, Avi Bar-Massada, María Eugenia Beget, Matthias Boer, Ross Bradstock, Tegan Brown, Francesc Xavier Castro, Rui Chen, Emilio Chuvieco, Mark Danson, Cihan Ünal Değirmenci, Ruth Delgado-Dávila, Philip Dennison, Carlos Di Bella, Oriol Domenech, Jean-Baptiste Féret, Greg Forsyth, Eva Gabriel, Zisis Gagkas, Fatma Gharbi, Elena Granda, Anne Griebel, Binbin He, Matt Jolly, Ivan Kotzur, Tineke Kraaij, Agnes Kristina, Pınar Kütküt, Jean-Marc Limousin, M. Pilar Martín, Antonio T. Monteiro, Marco Morais, Bruno Moreira, Florent Mouillot, Samukelisiwe Msweli, Rachael H. Nolan, Grazia Pellizzaro, Yi Qi, Xingwen Quan, Victor Esco De Dios, Dar Roberts, Çağatay Tavşanoğlu, Andy F. S. Taylor, Jackson Taylor, İrem Tüfekcioğlu, Andrea Ventura, Nicolas Younes Cardenas

School of Natural Resources: Faculty Publications

Globe-LFMC 2.0, an updated version of Globe-LFMC, is a comprehensive dataset of over 280,000 Live Fuel Moisture Content (LFMC) measurements. These measurements were gathered through field campaigns conducted in 15 countries spanning 47 years. In contrast to its prior version, Globe-LFMC 2.0 incorporates over 120,000 additional data entries, introduces more than 800 new sampling sites, and comprises LFMC values obtained from samples collected until the calendar year 2023. Each entry within the dataset provides essential information, including date, geographical coordinates, plant species, functional type, and, where available, topographical details. Moreover, the dataset encompasses insights into the sampling and weighing procedures, …

Beach Processes Controlling Erosional Hotspots And Their Influences On Beach Nourishment Performances: A Case Study Along West-Central Florida Barrier Island Beaches, Sophia Gutierrez

USF Tampa Graduate Theses and Dissertations

This study examines the long-term performance of repeated beach nourishment over an approximately 35-year period at two barrier islands, Sand Key and Treasure Island along the west-central Florida coast, USA. Five cycles of beach nourishment on Sand Key and six on Treasure Island were conducted during the study period. Three erosional hotspots were identified along a combined 14-km stretch of the nourished beach. The processes that cause the erosional hotspot were examined through numerical modeling of nearshore wave and current fields.

The most recent three nourishments since 2006 were monitored systematically by this study. Beach profiles were surveyed bimonthly to …

Subroups Of Coxeter Groups And Stallings Foldings, Jake A. Murphy

LSU Doctoral Dissertations

For each finitely generated subgroup of a Coxeter group, we define a cell complex called a completion. We show that these completions characterizes the index and normality of the subgroup. We construct a completion corresponding to the intersection of two subgroups and use this construction to characterize malnormality of subgroups of right-angled Coxeter groups. Finally, we show that if a completion of a subgroup is finite, then the subgroup is quasiconvex. Using this, we show that certain reflection subgroups of a Coxeter are quasiconvex.

Comparative Analysis Of Time Series Models On U.S. Stock And Exchange Rates: Bayesian Estimation Of Time Series Error Term Model Versus Machine Learning Approaches, Young Keun Yang

USF Tampa Graduate Theses and Dissertations

This study presents a comparative analysis of contemporary applications of time series models, focusing on the Bayesian approach. In contrast to many nonparametric studies, the Bayesian approach circumvents the common issue of bandwidth selection by offering systematic estimation and avoiding ad hoc methods. Specifically, we delve into the Bayesian approach for estimating the autocovariance function of a time series model’s error term. Traditional time series models often make the unrealistic assumption of a constant error term. Furthermore, models such as autoregressive conditional heteroskedasticity (ARCH) and general autoregressive conditional heteroskedasticity (GARCH) address the limitation of constant variance by assuming an autoregressive …

Analytic Wavefront Sets Of Spherical Distributions On The De Sitter Space, Iswarya Sitiraju

LSU Doctoral Dissertations

In this work, we determine the wavefront set of certain eigendistributions of the Laplace-Beltrami operator on the de Sitter space. Let G′ = O_1,n(R) be the Lorentz group, and let H′ = O_1,n−1(R) ⊂ G′ be its subset. The de Sitter space dSⁿ is a one-sheeted hyperboloid in R^1,n isomorphic to G′/H′. A spherical distribution is an H′-invariant eigendistribution of the Laplace-Beltrami operator on dSⁿ. The space of spherical distributions with eigenvalue λ, denoted by D_λ^H'(dSⁿ), has dimension 2. We construct a basis for the space of …