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Active Deformation And Plio-Pleistocene Fluvial Reorganization Of The Western Kura Fold-Thrust Belt, Georgia: Implications For The Evolution Of The Greater Caucasus Mountains, Lasha Sukhishvili, Adam M. Forte, Giorgi Merebashvili, Joel Leonard, Kelin X. Whipple, Zurab Javakhishvili, Arjun Heimsath, Tea Godoladze Jan 2020

Active Deformation And Plio-Pleistocene Fluvial Reorganization Of The Western Kura Fold-Thrust Belt, Georgia: Implications For The Evolution Of The Greater Caucasus Mountains, Lasha Sukhishvili, Adam M. Forte, Giorgi Merebashvili, Joel Leonard, Kelin X. Whipple, Zurab Javakhishvili, Arjun Heimsath, Tea Godoladze

Faculty Publications

© The Author(s), 2020. Published by Cambridge University Press. Since Plio-Pleistocene time, southward migration of shortening in the eastern part of the Greater Caucasus into the Kura foreland basin has progressively formed the Kura fold-thrust belt and Alazani piggyback basin, which separates the Kura fold-thrust belt from the Greater Caucasus. Previous work argued for an eastward propagation of the Kura fold-thrust belt, but this hypothesis was based on coarse geological maps and speculative ages for units within the Kura fold-thrust belt. Here we investigate the initiation of deformation within the Gombori range in the western Kura fold-thrust belt and evaluate …

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The Role Of Functional Strategies In Global Plant Distribution, Huixuan Liao, Daijiang Li, Ting Zhou, Bei Huang, Haijie Zhang, Baoming Chen, Shaolin Peng Jan 2020

The Role Of Functional Strategies In Global Plant Distribution, Huixuan Liao, Daijiang Li, Ting Zhou, Bei Huang, Haijie Zhang, Baoming Chen, Shaolin Peng

Faculty Publications

© 2020 The Authors. Ecography published by John Wiley & Sons Ltd on behalf of Nordic Society Oikos Understanding the determinants of species distributions is a central topic in ecology. Competition, stress tolerance and colonization, respectively represented by Grime's competitor (C), stress-tolerator (S) and ruderal (R) schemes, are three important functions that interactively influence plant distributions. In this study, we compiled a dataset of 2645 vascular plant species to explore the roles of the CSR strategies in global plant distribution. We analyzed the associations between the CSR scores and species range size with phylogenetic generalized least square (PGLS) models and …

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Female Reproductive State Is Associated With Changes In Distinct Arginine Vasotocin Cell Types In The Preoptic Area Of Astatotilapia Burtoni, Julie M. Butler, Chase M. Anselmo, Karen P. Maruska Jan 2020

Female Reproductive State Is Associated With Changes In Distinct Arginine Vasotocin Cell Types In The Preoptic Area Of Astatotilapia Burtoni, Julie M. Butler, Chase M. Anselmo, Karen P. Maruska

Faculty Publications

© 2020 Wiley Periodicals LLC Nonapeptides play a crucial role in mediating reproduction, aggression, and parental care across taxa. In fishes, arginine vasotocin (AVT) expression is related to social and/or reproductive status in most male fishes studied to date, and is linked to territorial defense, paternal care, and courtship. Despite a plethora of studies examining AVT in male fishes, relatively little is known about how AVT expression varies with female reproductive state or its role in female social behaviors. We used multiple methods for examining the AVT system in female African cichlid fish Astatotilapia burtoni, including immunohistochemistry for AVT, in …

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Halobacterium Bonnevillei Sp. Nov., Halobaculum Saliterrae Sp. Nov. And Halovenus Carboxidivorans Sp. Nov., Three Novel Carbon Monoxide-Oxidizing Halobacteria From Saline Crusts And Soils, Marisa R. Myers, G. M. King Jan 2020

Halobacterium Bonnevillei Sp. Nov., Halobaculum Saliterrae Sp. Nov. And Halovenus Carboxidivorans Sp. Nov., Three Novel Carbon Monoxide-Oxidizing Halobacteria From Saline Crusts And Soils, Marisa R. Myers, G. M. King

Faculty Publications

© 2020 The Authors. Three novel carbon monoxide-oxidizing Halobacteria were isolated from Bonneville Salt Flats (Utah, USA) salt crusts and nearby saline soils. Phylogenetic analysis of 16S rRNA gene sequences revealed that strains PCN9T, WSA2T and WSH3T belong to the genera Halobacterium, Halobaculum and Halovenus, respectively. Strains PCN9T, WSA2T and WSH3T grew optimally at 40 °C (PCN9T) or 50 °C (WSA2T, WSH3T). NaCl optima were 3 M (PCN9T, WSA2T) or 4 M NaCl (WSH3T). Carbon monoxide was oxidized by all isolates, each of which contained a molybdenum-dependent CO dehydrogenase. G+C contents for the three respective isolates were 66.75, 67.62, and …

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Speciation-By-Depth On Coral Reefs: Sympatric Divergence With Gene Flow Or Cryptic Transient Isolation?, Carlos Prada, Michael E. Hellberg Jan 2020

Speciation-By-Depth On Coral Reefs: Sympatric Divergence With Gene Flow Or Cryptic Transient Isolation?, Carlos Prada, Michael E. Hellberg

Faculty Publications

© 2020 The Authors. Journal of Evolutionary Biology published by John Wiley & Sons Ltd on behalf of European Society for Evolutionary Biology The distributions of many sister species in the sea overlap geographically but are partitioned along depth gradients. The genetic changes leading to depth segregation may evolve in geographic isolation as a prerequisite to coexistence or may emerge during primary divergence leading to new species. These alternatives can now be distinguished via the power endowed by the thousands of scorable loci provided by second-generation sequence data. Here, we revisit the case of two depth-segregated, genetically isolated ecotypes of …

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The Avr4 Effector Is Involved In Cercosporin Biosynthesis And Likely Affects The Virulence Of Cercospora Cf. Flagellaris On Soybean, Josielle Santos Rezende, Marija Zivanovic, Maria Izabel Costa De Novaes, Zhi Yuan Chen Jan 2020

The Avr4 Effector Is Involved In Cercosporin Biosynthesis And Likely Affects The Virulence Of Cercospora Cf. Flagellaris On Soybean, Josielle Santos Rezende, Marija Zivanovic, Maria Izabel Costa De Novaes, Zhi Yuan Chen

Faculty Publications

One of the most devastating fungal diseases of soybean in the southern USA is Cercospora leaf blight (CLB), which is caused mainly by Cercospora cf. flagellaris. Recent studies found that the fungal effector AVR4, originally identified in Cladosporium fulvum as a chitin-binding protein, is highly conserved among other Cercospora species. We wanted to determine whether it is present in C. cf. flagellaris and, if so, whether it plays a role in the pathogen infection of soybean. We cloned the Avr4 gene and created C. cf. flagellaris ∆avr4 mutants, which produced little cercosporin and significantly reduced expression of cercosporin biosynthesis genes. …

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Plant-Parasitic Nematodes Associated With The Root Zone Of Hop Cultivars Planted In A Florida Field Soil, Tristan T. Watson, Marco Suarez, Zhanao Deng, Johan A. Desaeger Jan 2020

Plant-Parasitic Nematodes Associated With The Root Zone Of Hop Cultivars Planted In A Florida Field Soil, Tristan T. Watson, Marco Suarez, Zhanao Deng, Johan A. Desaeger

Faculty Publications

In early 2016, hop plants were introduced into Florida. By late 2016, the hop plants were showing stunted growth and were heavily parasitized by Meloidogyne javanica. In this study, we determined host susceptibility of 14 hop cultivars to M. javanica in a greenhouse experiment and monitored population development of plant-parasitic nematode species in the root zone of 17 hop cultivars planted in three newly established hop yards in Florida. Plant-parasitic nematodes in the rooting zone soil of field grown hop plants included M. javanica, Pratylenchus brachyurus, Paratrichodorus minor, Belonolaimus longicaudatus, Xiphinema setariae/vulgare complex, Mesocriconema xenoplax, and Helicotylenchus dihystera; however, soil …

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Improving Health Behaviors Through Community Engagement: Challenge For A Healthier Louisiana, Stephanie T. Broyles, Elizabeth A. Gollub, Allison Tohme, Peter T. Katzmarzyk Jan 2020

Improving Health Behaviors Through Community Engagement: Challenge For A Healthier Louisiana, Stephanie T. Broyles, Elizabeth A. Gollub, Allison Tohme, Peter T. Katzmarzyk

Faculty Publications

There is increasing recognition that community-based approaches may have merit in improving physical activity and healthy eating behaviors. The “Challenge for a Healthier Louisiana” program supported twelve projects that addressed the root causes of obesity through integrated community-level changes. Partnerships provided community-based obesity prevention by promoting healthier eating and/or physical activity through enhanced infrastructure, policy changes, and programming. To evaluate whether the program resulted in changes in healthy eating and/or physical activity among adults, surveys were conducted pre- and postintervention among participants. Participants who were exposed to physical activity programs were more likely to adopt the consumption of fruits (odds …

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Assessing Salvinia Molesta Impact On Environmental Conditions In An Urban Lake: Case Study Of Lago Las Curias, Puerto Rico, Charles F. Wahl, Rodrigo Diaz, Jorge Ortiz-Zayas Jan 2020

Assessing Salvinia Molesta Impact On Environmental Conditions In An Urban Lake: Case Study Of Lago Las Curias, Puerto Rico, Charles F. Wahl, Rodrigo Diaz, Jorge Ortiz-Zayas

Faculty Publications

Giant salvinia (Salvinia molesta Mitchell, Salviniaceae) is a free-floating fern native to Brazil that alters natural processes in aquatic ecosystems, causing ecological problems for water resource managers. Due to its ease of dispersal through fragmentation and rapid growth, giant salvinia can quickly become problematic, requiring persistent management efforts. If left unmanaged, giant salvinia creates a thick mat of vegetation, which limits sunlight penetration, reducing aquatic macrophytes, lowering dissolved oxygen and stressing aquatic organisms. Giant salvinia was first reported in Lago Las Curias, Cupey, San Juan, Puerto Rico, USA, in 2016 and covered the entire 19 ha waterbody in 2018. In …

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Diverging Landscape Impacts On Macronutrient Status Despite Overlapping Diets In Managed (Apis Mellifera) And Native (Melissodes Desponsa) Bees, Christina L. Mogren, Mariá Soledad Benítez, Kevin Mccarter, Frédéric Boyer, Jonathan G. Lundgren Jan 2020

Diverging Landscape Impacts On Macronutrient Status Despite Overlapping Diets In Managed (Apis Mellifera) And Native (Melissodes Desponsa) Bees, Christina L. Mogren, Mariá Soledad Benítez, Kevin Mccarter, Frédéric Boyer, Jonathan G. Lundgren

Faculty Publications

Declining pollinator populations worldwide are attributed to multiple stressors, including the loss of quality forage. Habitat management in agricultural areas often targets honey bees (Apis mellifera L.) specifically, with the assumption that native bees will benefit from an 'umbrella species' strategy. We tested this theory using a conservation physiology approach to compare the effects of landscape composition and floral dietary composition on the physiological status of honey bees and Melissodes desponsa in eastern South Dakota, USA. The total glycogen, lipid and protein concentrations were quantified from field collected bees. Next-generation sequencing of the trnL chloroplast gene from bee guts was …

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The Association Between Selected Molecular Biomarkers And Ambulatory Blood Pressure Patterns In African Chronic Kidney Disease And Hypertensive Patients Compared With Normotensive Controls: Protocol For A Longitudinal Study, Abiodun Moshood Adeoye, Oladimeji Adebayo, Busayo Abiola, Bamidele Iwalokun, Bamidele Tayo, Fadi Charchar, Akinlolu Ojo, Richard Cooper Jan 2020

The Association Between Selected Molecular Biomarkers And Ambulatory Blood Pressure Patterns In African Chronic Kidney Disease And Hypertensive Patients Compared With Normotensive Controls: Protocol For A Longitudinal Study, Abiodun Moshood Adeoye, Oladimeji Adebayo, Busayo Abiola, Bamidele Iwalokun, Bamidele Tayo, Fadi Charchar, Akinlolu Ojo, Richard Cooper

Faculty Publications

Background: Chronic kidney disease (CKD) is a burgeoning epidemic in sub-Saharan Africa. Abnormal blood pressure variations are prevalent in CKD and potentiate the risk of cardiovascular morbidity and mortality. Certain genetic variants (angiotensin II receptor type 1 1166 A>C and angiotensin-converting enzyme insertion and deletion polymorphisms) and biomarkers such as interleukin-6, tumor necrosis factor, soluble (s) E-selectin, homocysteine, and highly sensitive C-reactive protein have been shown to affect blood pressure variability among non-African CKD, hypertensive. and nonhypertensive CKD population. However, the contributions of the pattern, genetic, and environmental determinants of ambulatory blood pressure in African CKD have not been …

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Educating For Whiteness: Applying Critical Race Theory’S Revisionist History In Library & Information Science Research, Suzanne Marie Stauffer Jan 2020

Educating For Whiteness: Applying Critical Race Theory’S Revisionist History In Library & Information Science Research, Suzanne Marie Stauffer

Faculty Publications

No abstract provided.

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The Buzz About Bee Campuses: Student Thoughts Regarding Pollinator Conservation, Hannah Penn, Jerrod Penn, Macy Hagan, Wuyang Hu Jan 2020

The Buzz About Bee Campuses: Student Thoughts Regarding Pollinator Conservation, Hannah Penn, Jerrod Penn, Macy Hagan, Wuyang Hu

Faculty Publications

No abstract provided.

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Evaluation Of Gene Flow In Structured And Seed Blend Refuge Systems Of Non-Bt And Bt Corn, Galen P. Dively, Fangneng Huang, Isaac Oyediran, Tony Burd, Shannon Morsello Jan 2020

Evaluation Of Gene Flow In Structured And Seed Blend Refuge Systems Of Non-Bt And Bt Corn, Galen P. Dively, Fangneng Huang, Isaac Oyediran, Tony Burd, Shannon Morsello

Faculty Publications

Gene flow between Bt and non-Bt plants can have implications for resistance management. In 2013 and 2014, field trials in Maryland and Louisiana measured gene flow in three refuge systems: (1) structured refuge stand of purple-seeded corn flanked on both sides by stands of yellow corn; (2) seed blend of yellow corn containing purple corn as refuges; and (3) seed blend of purple-seeded corn containing yellow corn as refuges. The presence of cross-pollinated purple kernels was used as a marker to quantify gene flow. In the structured refuge, cross-pollination between Bt and structured refuge plants averaged 5.4% on adjacent rows …

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Early Detection Of Parkinson's Disease Using Deep Learning And Machine Learning, Wu Wang, Junho Lee, Fouzi Harrou, Ying Sun Jan 2020

Early Detection Of Parkinson's Disease Using Deep Learning And Machine Learning, Wu Wang, Junho Lee, Fouzi Harrou, Ying Sun

Faculty Publications

Accurately detecting Parkinson's disease (PD) at an early stage is certainly indispensable for slowing down its progress and providing patients the possibility of accessing to disease-modifying therapy. Towards this end, the premotor stage in PD should be carefully monitored. An innovative deep-learning technique is introduced to early uncover whether an individual is affected with PD or not based on premotor features. Specifically, to uncover PD at an early stage, several indicators have been considered in this study, including Rapid Eye Movement and olfactory loss, Cerebrospinal fluid data, and dopaminergic imaging markers. A comparison between the proposed deep learning model and …

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Wind Power Prediction Using Ensemble Learning-Based Models, Junho Lee, Wu Wang, Fouzi Harrou, Ying Sun Jan 2020

Wind Power Prediction Using Ensemble Learning-Based Models, Junho Lee, Wu Wang, Fouzi Harrou, Ying Sun

Faculty Publications

Wind power is one of the most potential energies and the major available renewable energy sources. Precisely predicting wind power production is essential for the management and the integration of wind power in a smart grid. The goal of this study is to predict wind power production with sufficient accuracy based on various factors using ensemble learning-based methods that consider the time-dependent nature of the wind power measurements. Essentially, the ensemble learning methods combine multiple learners to obtain an enhanced prediction performance in comparison to conventional standalone learners. In addition, they reduce the overall prediction error and have the capacity …

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Do Microcredit Loans Do What They Are Intended To Do? A Case Study Of The Credit Village Microcredit Programme In China, Meishan Jiang, Krishna P. Paudel, Fan Zou Jan 2020

Do Microcredit Loans Do What They Are Intended To Do? A Case Study Of The Credit Village Microcredit Programme In China, Meishan Jiang, Krishna P. Paudel, Fan Zou

Faculty Publications

© 2020 John Wiley & Sons, Ltd. The purpose of this study is to assess if the credit village is an effective way to develop a microcredit programme in China from the perspective of poverty reduction policy and risk monitoring. Cross-sectional household survey data from three credit villages in the Yunan County of China are analysed using 3SLS and IV probit models. The major finding is that the credit village loosens credit restrictions to some extent. However, it has no impact on educational expenditures, medical expenditures, long-term assets, short-term assets and women's rights. It is our observation that the microcredit …

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Using Community Phylogenetics To Assess Phylogenetic Structure In The Fitzcarrald Region Of Western Amazonia, Jack M. Craig, Tiago P. Carvalho, Prosanta Chakrabarty, Valerie Derouen, Hernán Ortega, Paulo Petry, Roberto E. Reis, Victor A. Tagliacollo, James S. Albert Jan 2020

Using Community Phylogenetics To Assess Phylogenetic Structure In The Fitzcarrald Region Of Western Amazonia, Jack M. Craig, Tiago P. Carvalho, Prosanta Chakrabarty, Valerie Derouen, Hernán Ortega, Paulo Petry, Roberto E. Reis, Victor A. Tagliacollo, James S. Albert

Faculty Publications

© 2020 The Authors. Di versity and Distributions Published by SBI. Here we explore the use of community phylogenetics as a tool to document patterns of biodiversity in the Fitzcarrald region, a remote area in Southwestern Amazonia. For these analyses, we subdivide the region into basin-wide assemblages encompassing the headwaters of four Amazonian tributaries (Urubamba, Yuruá, Purús and Las Piedras basins), and habitat types: river channels, terra firme (non-floodplain) streams, and floodplain lakes. We present a robust, well-documented collection of fishes from the region including 272 species collected from 132 field sites over 63 field days and four years, comprising …

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Extensive Paraphyly In The Typical Owl Family (Strigidae), Jessie F. Salter, Carl H. Oliveros, Peter A. Hosner, Joseph D. Manthey, Mark B. Robbins, Robert G. Moyle, Robb T. Brumfield, Brant C. Faircloth Jan 2020

Extensive Paraphyly In The Typical Owl Family (Strigidae), Jessie F. Salter, Carl H. Oliveros, Peter A. Hosner, Joseph D. Manthey, Mark B. Robbins, Robert G. Moyle, Robb T. Brumfield, Brant C. Faircloth

Faculty Publications

© 2019 American Ornithological Society 2019. Published by Oxford University Press for the American Ornithological Society. The typical owl family (Strigidae) comprises 194 species in 28 genera, 14 of which are monotypic. Relationships within and among genera in the typical owls have been challenging to discern because mitochondrial data have produced equivocal results and because many monotypic genera have been omitted from previous molecular analyses. Here, we collected and analyzed DNA sequences of ultraconserved elements (UCEs) from 43 species of typical owls to produce concatenated and multispecies coalescent-based phylogenetic hypotheses for all but one genus in the typical owl family. …

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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 Jan 2020

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, …

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Averages Along The Primes: Improving And Sparse Bounds, Rui Han, Ben Krause, Michael T. Lacey, Fan Yang Jan 2020

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.

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A Higher-Dimensional Bourgain-Dyatlov Fractal Uncertainty Principle, Rui Han, Wilhelm Schlag Jan 2020

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.

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The 2-Factor Polynomial Detects Even Perfect Matchings, Scott Baldridge, Adam M. Lowrance, Ben Mccarty Jan 2020

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.

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Minimal Flag Triangulations Of Lower-Dimensional Manifolds, Christin Bibby, Andrew Odesky, Mengmeng Wang, Shuyang Wang, Ziyi Zhang, Hailun Zheng Jan 2020

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 ≥ …

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Some Numeric Hypergeometric Supercongruences, Ling Long Jan 2020

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.

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Circuit-Difference Matroids, George Drummond, James Oxley, Kevin Grace, Tara Fife Jan 2020

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. …

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On Density-Critical Matroids, Rutger Campbell, Kevin Grace, James Oxley, Geoff Whittle Jan 2020

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 …

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Excluded Minors Are Almost Fragile, Nick Brettell, Ben Clark, James Oxley, Charles Semple, Geoff Whittle Jan 2020

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.

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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 Jan 2020

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 …

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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 Jan 2020

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].

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