Digital Commons Network^™

Interspecific Variation In Hypoxia Tolerance And Hypoxia Acclimation Responses In Killifish From The Family Fundulidae, Brittney G. Borowiec, Ryan D. Hoffman, Chelsea D. Hess, Fernando Galvez, Graham R. Scott

Faculty Publications

© 2020. Published by The Company of Biologists Ltd Hypoxia is a pervasive stressor in aquatic environments, and both phenotypic plasticity and evolutionary adaptation could shape the ability to cope with hypoxia. We investigated evolved variation in hypoxia tolerance and the hypoxia acclimation response across fundulid killifishes that naturally experience different patterns of hypoxia exposure. We compared resting O2 consumption rate (M O2), and various indices of hypoxia tolerance [critical O2 tension (Pcrit), regulation index (RI), O2 tension (PO2) at loss of equilibrium (PLOE) and time to LOE (tLOE) at 0.6 kPa O2] in Fundulus confluentus, Fundulus diaphanus, Fundulus heteroclitus, …

Averages Along The Primes: Improving And Sparse Bounds, Rui Han, Ben Krause, Michael T. Lacey, Fan Yang

Faculty Publications

Consider averages along the prime integers P given by ANf(x)=N-1 p:p≤N(logp)f(x-p). A N f(x) = {N-1*∑ ∈ P:p ≤ N} (p)f(x-p).} These averages satisfy a uniform scale-free p-improving estimate. For all 1 < p < 2, there is a constant Cp so that for all integer N and functions f supported on [0, N], there holds N-1/p′-ANf-p′≤CpN-1/p-f-p. {N-1/p'ANf |ℓ p'≤ C_p N-1p| f |ℓ p. The maximal function A∗f = supN|AN f | satisfies (p, p) sparse bounds for all 1 < p < 2. The latter are the natural variants of the scale-free bounds. As a corollary, A∗ is bounded on Ap(w), for all weights w in the Muckenhoupt Ap class. No prior weighted inequalities for A∗ were known.

A Higher-Dimensional Bourgain-Dyatlov Fractal Uncertainty Principle, Rui Han, Wilhelm Schlag

Faculty Publications

We establish a version of the fractal uncertainty principle, obtained by Bourgain and Dyatlov in 2016, in higher dimensions. The Fourier support is limited to sets Y ⊂ Rd which can be covered by finitely many products of δ-regular sets in one dimension, but relative to arbitrary axes. Our results remain true if Y is distorted by diffeomorphisms. Our method combines the original approach by Bourgain and Dyatlov, in the more quantitative 2017 rendition by Jin and Zhang, with Cartan set techniques.

The 2-Factor Polynomial Detects Even Perfect Matchings, Scott Baldridge, Adam M. Lowrance, Ben Mccarty

Faculty Publications

In this paper, we prove that the 2-factor polynomial, an invariant of a planar trivalent graph with a perfect matching, counts the number of 2-factors that contain the perfect matching as a subgraph. Consequently, we show that the polynomial detects even perfect matchings.

Minimal Flag Triangulations Of Lower-Dimensional Manifolds, Christin Bibby, Andrew Odesky, Mengmeng Wang, Shuyang Wang, Ziyi Zhang, Hailun Zheng

Faculty Publications

We prove the following results on flag triangulations of 2-and 3-manifolds. In dimension 2, we prove that the vertex-minimal flag triangulations of ℝP and S × S have 11 and 12 vertices, respectively. In general, we show that 8 + 3k (resp. 8+4k) vertices suffice to obtain a flag triangulation of the connected sum of k copies of ℝP (resp. S × S ). In dimension 3, we describe an algorithm based on the Lutz–Nevo theorem which provides supporting computational evidence for the following generalization of the Charney–Davis conjecture: for any flag 3-manifold, γ := f −5 f +16 ≥ …

Some Numeric Hypergeometric Supercongruences, Ling Long

Faculty Publications

In this article, we list a few hypergeometric supercongruence conjectures based on two evaluation formulas of Whipple and numeric data computed using Magma and Sagemath.

Circuit-Difference Matroids, George Drummond, James Oxley, Kevin Grace, Tara Fife

Faculty Publications

One characterization of binary matroids is that the symmetric difference of every pair of intersecting circuits is a disjoint union of circuits. This paper considers circuit-difference matroids, that is, those matroids in which the symmetric difference of every pair of intersecting circuits is a single circuit. Our main result shows that a connected regular matroid is circuit-difference if and only if it contains no pair of skew circuits. Using a result of Pfeil, this enables us to explicitly determine all regular circuit-difference matroids. The class of circuit-difference matroids is not closed under minors, but it is closed under series minors. …

On Density-Critical Matroids, Rutger Campbell, Kevin Grace, James Oxley, Geoff Whittle

Faculty Publications

For a matroid M having m rank-one flats, the density d(M) isr(M)m unless m = 0, in which case d(M) = 0. A matroid is density-critical if all of its proper minors of non-zero rank have lower density. By a 1965 theorem of Edmonds, a matroid that is minor-minimal among simple matroids that cannot be covered by k independent sets is density-critical. It is straightforward to show that U1,k+1 is the only minor-minimal loopless matroid with no covering by k independent sets. We prove that there are exactly ten minor-minimal simple obstructions to a matroid being able to be covered …

Excluded Minors Are Almost Fragile, Nick Brettell, Ben Clark, James Oxley, Charles Semple, Geoff Whittle

Faculty Publications

Let M be an excluded minor for the class of P-representable matroids for some partial field P, and let N be a 3-connected strong P-stabilizer that is non-binary. We prove that either M is bounded relative to N, or, up to replacing M by a Δ-Y-equivalent excluded minor, we can choose a pair of elements {a,b} such that either M\{a,b} is N-fragile, or M⁎\{a,b} is N⁎-fragile.

Context-Aware Design Of Cyber-Physical Human Systems (Cphs), Supratik Mukhopadhyay, Subhajit Sidhanta, Arnab Ganguly, Qun Liu, Edward Collier, Yimin Zhu, Ravindra Gudishala, Chanachok Chokwitthaya, Robert Dibiano, Alimire Nabijiang, Sanaz Saeidi

Faculty Publications

Recently, it has been widely accepted by the research community that interactions between humans and cyber-physical infrastructures have played a significant role in determining the performance of the latter. The existing paradigm for designing cyber-physical systems for optimal performance focuses on developing models based on historical data. The impacts of context factors driving human system interaction are challenging and are difficult to capture and replicate in existing design models. As a result, many existing models do not or only partially address those context factors of a new design owing to the lack of capabilities to capture the context factors. This …

Exhibition "Louisiana's Natural Treasure: Margaret Stones, Botanical Artist", Leah Wood Jewett, John D. Miles, Christina Riquelmy

Special Collections

In 2020, LSU Libraries Special Collections presented the exhibition “Louisiana’s Natural Treasure: Margaret Stones, Botanical Artist” at Hill Memorial Library, featuring selected original watercolor paintings and archival materials related to the Native Flora of Louisiana project.

A native of Australia, Margaret Stones (1920-2018) achieved an acclaimed international career that spanned three continents. Commissioned by LSU and funded by private donations, more than 200 watercolor drawings of Louisiana plants produced by Stones during the 1970s and 1980s are among the most treasured holdings of LSU Libraries Special Collections.

The Native Flora of Louisiana project was grounded in a long historical tradition …

Additive Schwarz Preconditioners For A State Constrained Elliptic Distributed Optimal Control Problem Discretized By A Partition Of Unity Method, Susanne C. Brenner, Christopher B. Davis, Li Yeng Sung

Faculty Publications

The minimization problem (2) is discretized in [4] by a partition of unity method (PUM). The goal of this paper is to use the ideas in [5] for an obstacle problem of clamped Kirchhoff plates to develop preconditioners for the discrete problems in [4].

A Balancing Domain Decomposition By Constraints Preconditioner For A C0 Interior Penalty Method, Susanne C. Brenner, Eun Hee Park, Li Yeng Sung, Kening Wang

Faculty Publications

Consider the following weak formulation of a fourth order problem on a bounded polygonal domain Ω in R : 2

Finite Element Methods For One Dimensional Elliptic Distributed Optimal Control Problems With Pointwise Constraints On The Derivative Of The State, S. C. Brenner, L. Y. Sung, W. Wollner

Faculty Publications

We investigate C finite element methods for one dimensional elliptic distributed optimal control problems with pointwise constraints on the derivative of the state formulated as fourth order variational inequalities for the state variable. For the problem with Dirichlet boundary conditions, we use an existing H52-ϵ regularity result for the optimal state to derive O(h12-ϵ) convergence for the approximation of the optimal state in the H norm. For the problem with mixed Dirichlet and Neumann boundary conditions, we show that the optimal state belongs to H under appropriate assumptions on the data and obtain O(h) convergence for the approximation of the …

Additive Schwarz Preconditioners For A Localized Orthogonal Decomposition Method, Susanne C. Brenner, José C. Garay, Li Yeng Sung

Faculty Publications

We investigate a variant of the localized orthogonal decomposition method (Henning and Peterseim, [Multiscale Model. Simul., 11 (2013), pp. 1149 1175] and Malqvist and Peterseim, [Math. Comp., 83 (2014), pp. 2583 2603]) for elliptic problems with rough coefficients. The construction of the basis of the multiscale finite element space is based on domain decomposition techniques, which is motivated by the recent work of Kornhuber, Peterseim, and Yserentant [Math. Comp., 87 (2018), pp. 2765 2774]. We also design and analyze additive Schwarz domain decomposition preconditioners for the resulting discrete problems.

P 1 Finite Element Methods For An Elliptic Optimal Control Problem With Pointwise State Constraints, Susanne C. Brenner, Li Yeng Sung, Joscha Gedicke

Faculty Publications

We present theoretical and numerical results for two P finite element methods for an elliptic distributed optimal control problem on general polygonal/polyhedral domains with pointwise state constraints. 1

Extremal Khovanov Homology Of Turaev Genus One Links, Oliver T. Dasbach, Adam M. Lowrance

Faculty Publications

The Turaev genus of a link can be thought of as a way of measuring how nonalternating a link is. A link is Turaev genus zero if and only if it is alternating, and in this viewpoint, links with large Turaev genus are very nonalternating. In this paper, we study Turaev genus one links, a class of links which includes almost alternating links. We prove that the Khovanov homology of a Turaev genus one link is isomorphic to Z in at least one of its extremal quantum gradings. As an application, we compute or nearly compute the maximal Thurston Bennequin …

Stabilization For A Chain Of Saturating Integrators Arising In The Visual Landing Of Aircraft With Sampling, Laurent Burlion, Michael Malisoff, Frédéric Mazenc

Faculty Publications

We provide a new output feedback control design for a chain of saturating integrators with imprecise output measurements where the outputs can also contain delays and sampling. Using a backstepping approach that leads to pointwise delays in the control and a dynamic extension, we prove input-to-state stability using a new dynamic extension approach. We utilize our main result to solve a problem in the visual landing of aircraft in the glide phase in the presence of delayed and sampled image processing.

Delayed Newton-Based Multivariable Extremum Seeking With Sequential Predictors, Michael Malisoff, Miroslav Krstic

Faculty Publications

We provide a new method for Newton-based multivariable extremum seeking which allows different delays in each of the input channels. We allow arbitrarily long input delays. Our sequential predictor delay compensation method eliminates the need for the distributed terms that were required in earlier methods. We illustrate our method in a source seeking example.

A New Spectroscopic Analysis Of The Massive O + O Type Binary Hd54662ab, R. H. Barba, C. Sabin-Sanjulian, J. I. Arias, R. C. Gamen, N. I. Morrell, G. Ferrero, J. Maiz Apellaniz, C. Putkuri, S. Simon Diaz, T. S. Boyajian, A. W. Fullerton, M. V. Mcswain

Faculty Publications

HD54662AB is one of the three O + OB binaries known so far with orbital period longer than 1000 d, offering the opportunity to test scenarios of massive star formation and models of single stellar evolution. Here, we present a detailed study of this system based on new high-resolution spectra and data. A disentangling method is used to recover the individual spectra of the primary and secondary components, which are classified as O6.5 V(n)z and O7.5 Vz, respectively. Combining radial velocity measurements and astrometric data, a new absolute orbit with a period of 2113 ± 9 d and an eccentricity …

Potential Predictability Of Net Primary Production In The Ocean, K.M. Krumhardt, N.S. Lovenduski, M.C. Long, J.Y. Luo, K. Lindsay, S. Yeager, C. Harrison

Faculty Publications

No abstract provided.

Marine Wild-Capture Fisheries After Nuclear War, K.J.N. Scherrer, C.S. Harrison, R.F. Heneghan, E. Galbraith, C.G. Bardeen, J. Coupe, J. Jägermeyr, N.S. Lovenduski, A. Luna, A. Robock, J. Stevens, S. Stevenson, O.B. Toon, L. Xia

Faculty Publications

No abstract provided.

Eddy-Modified Iron, Light, And Phytoplankton Cell Division Rates In The Simulated Southern Ocean, T. Rohr, C. Harrison, M.C. Long, P. Gaube, S.C. Doney

Faculty Publications

No abstract provided.

2020 Louisiana Summary: Agriculture & Natural Resources, Lsu Agcenter

Louisiana Summary: Agriculture and Natural Resources

This publication tabulates the value of Louisiana agriculture in 2020. Agents and specialists of the Louisiana Cooperative Extension Service, as well as other agencies – both private and public – compiled the data. Their analysis focuses on the animal, forestry, fisheries, plant and wildlife commodities that comprise our vital agricultural industry. Agricultural and natural resource industries contribute significantly to our state’s economy with the potential for increased economic benefits and job creation through value-added processing in urban and rural communities throughout Louisiana.

The food and fiber sector faced a significant number of issues and challenges during the 2020 calendar year. …

New Ab Initio Approach To Nuclear Reactions Based On The Symmetry-Adapted No-Core Shell Model, Alexis Mercenne, Kristina D. Launey, Jutta E. Escher, Tomas Dytrych, Jerry P. Draayer

Faculty Publications

We present the current development of a new ab initio approach for nuclear reactions that takes advantage of SU(3) symmetry and its relevant dynamics combined with the resonating group method. In this model, the structure of the clusters is based on the ab initio symmetry-adapted no-core shell model, which enables the description of spatially enhanced nuclear configurations. We will present the formalism that involves the expression of the norm kernels in the SU(3) symmetry-adapted basis, in addition to first results for the p-(formula presented), p-(formula presented)O and p-(formula presented)Ne scattering reactions.

The Influence Of Language Background And Second Language Phonetics Training On The Perception Of Lexical Stress In A Second Language, Todd A. Gibson, Carolina Bernales

Faculty Publications

Language background and second language (L2) training both have been found to contribute to L2 lexical stress perception. To explore their relative contributions, a lexical stress perception task was administered to a total of 129 university students of different language backgrounds. A group of 62 monolingual English-speaking students in the U.S.A. and 67 English-as-a-foreign-language students in Chile were asked to identify lexical stress in trochees and iambs. Chileans with previous phonetics training performed better than Chileans without the training and performed as well as their U.S. peers. U.S. participants and those Chileans without previous phonetics training performed better with trochees …

Vowel Acoustic Characteristics Of Southern American English Variation In Louisiana, Hyunju Chung

Faculty Publications

This study examined acoustic characteristics of vowels produced by speakers from Louisiana, one of the states in the Southern English dialect region. First, how Louisiana vowels differ from or are similar to the reported patterns of Southern dialect were examined. Then, within-dialect differences across regions in Louisiana were examined. Thirty-four female adult monolingual speakers of American English from Louisiana, ranging in age from 18 to 23, produced English monosyllabic words containing 11 vowels/i, É, e, É, æ, E, u, ÊŠ, o, É, É/. The first two formant frequencies at the midpoint of the vowel nucleus, direction, and amount of formant …

Rates And Predictors Of Co-Occurring Autism Spectrum Disorder In Boys With Fragile X Syndrome, Eileen Haebig, Audra Sterling, Andrea Barton-Hulsey, Laura Friedman

Faculty Publications

Background and aims: Males with fragile X syndrome display many behavioral features of autism spectrum disorder. Despite this overlap, our understanding of autism spectrum disorder symptoms and severity in fragile X syndrome is limited due to variation in assessment methods in the literature. Furthermore, the relationship between autism spectrum disorder symptoms and child characteristics, like age, language, and cognitive abilities, are not well understood in individuals with fragile X syndrome. Therefore, the first research aim was to compare the rates of autism spectrum disorder classifications from three commonly reported autism spectrum disorder assessments in the literature. Our second research aim …

Expressive Language Abilities Of Boys With Idiopathic Autism Spectrum Disorder And Boys With Fragile X Syndrome + Autism Spectrum Disorder: Cross-Context Comparisons, Elizabeth Hilvert, Audra Sterling, Eileen Haebig, Laura Friedman

Faculty Publications

Background and aims: Understanding the unique expressive language profiles of children with phenotypically similar, but distinct neurodevelopmental disorders, such as idiopathic autism spectrum disorder and fragile X syndrome with a co-diagnosis of autism spectrum disorder (fragile X syndrome + autism spectrum disorder), has both clinical and theoretical implications. However, comparative studies of these two clinical groups have been limited, and results have been inconsistent, partially as a result of different assessment methods being utilized. Thus, the current study compared the expressive language profiles of boys with idiopathic autism spectrum disorder and boys with fragile X syndrome + autism spectrum disorder …

Determination Of Clinical Parameters Sensitive To Functional Voice Disorders Applying Boosted Decision Stumps, Patrick Schlegel, Andreas M. Kist, Marion Semmler, Michael Dollinger, Melda Kunduk, Stephan Durr, Anne Schutzenberger

Faculty Publications

Background: Various voice assessment tools, such as questionnaires and aerodynamic voice characteristics, can be used to assess vocal function of individuals. However, not much is known about the best combinations of these parameters in identification of functional dysphonia in clinical settings. Methods: This study investigated six scores from clinically commonly used questionnaires and seven acoustic parameters. 514 females and 277 males were analyzed. The subjects were divided into three groups: one healthy group (N01) (49 females, 50 males) and two disordered groups with perceptually hoarse (FD23) (220 females, 96 males) and perceptually not hoarse (FD01) (245 females, 131 males) sounding …