Physical Sciences and Mathematics Commons^™

Alzheimer's Biomarkers Are Correlated With Brain Connectivity In Older Adults Differentially During Resting And Task States, Yang Jiang, Haiqing Huang, Erin Abner, Lucas S. Broster, Gregory A. Jicha, Frederick A. Schmitt, Richard Kryscio, Anders H. Andersen, David Powell, Linda J. Van Eldik, Brian T. Gold, Peter T. Nelson, Charles D. Smith, Mingzhou Ding

Behavioral Science Faculty Publications

β-amyloid (Aβ) plaques and tau-related neurodegeneration are pathologic hallmarks of Alzheimer’s disease (AD). The utility of AD biomarkers, including those measured in cerebrospinal fluid (CSF), in predicting future AD risk and cognitive decline is still being refined. Here, we explored potential relationships between functional connectivity (FC) patterns within the default-mode network (DMN), age, CSF biomarkers (Aβ₄₂ and pTau₁₈₁), and cognitive status in older adults. Multiple measures of FC were explored, including a novel time series-based measure [total interdependence (TI)]. In our sample of 27 cognitively normal older adults, no significant associations were found between levels of Aβ …

A Note On The Γ-Coefficients Of The Tree Eulerian Polynomial, Rafael S. González D'León

Mathematics Faculty Publications

We consider the generating polynomial of the number of rooted trees on the set {1,2,...,n} counted by the number of descending edges (a parent with a greater label than a child). This polynomial is an extension of the descent generating polynomial of the set of permutations of a totally ordered n-set, known as the Eulerian polynomial. We show how this extension shares some of the properties of the classical one. A classical product formula shows that this polynomial factors completely over the integers. From this product formula it can be concluded that this polynomial has positive coefficients …

First-Order Superfluid To Valence-Bond Solid Phase Transitions In Easy-Plane Su(N) Magnets For Small N, Jonathan D'Emidio, Ribhu K. Kaul

Physics and Astronomy Faculty Publications

We consider the easy-plane limit of bipartite SU(N) Heisenberg Hamiltonians, which have a fundamental representation on one sublattice and the conjugate to fundamental on the other sublattice. For N = 2 the easy plane limit of the SU(2) Heisenberg model is the well-known quantum XY model of a lattice superfluid. We introduce a logical method to generalize the quantum XY model to arbitrary N, which keeps the Hamiltonian sign-free. We show that these quantum Hamiltonians have a world-line representation as the statistical mechanics of certain tightly packed loop models of N colors in which neighboring loops are …

Long-Term Trend Analysis Of Precipitation And Air Temperature For Kentucky, United States, Somsubhra Chattopadhyay, Dwayne R. Edwards

Biosystems and Agricultural Engineering Faculty Publications

Variation in quantities such as precipitation and temperature is often assessed by detecting and characterizing trends in available meteorological data. The objective of this study was to determine the long-term trends in annual precipitation and mean annual air temperature for the state of Kentucky. Non-parametric statistical tests were applied to homogenized and (as needed) pre-whitened annual series of precipitation and mean air temperature during 1950–2010. Significant trends in annual precipitation were detected (both positive, averaging 4.1 mm/year) for only two of the 60 precipitation-homogenous weather stations (Calloway and Carlisle counties in rural western Kentucky). Only three of the 42 temperature-homogenous …

Graphene Oxide Quantum Dots Covalently Functionalized Pvdf Membrane With Significantly-Enhanced Bactericidal And Antibiofouling Performances, Zhiping Zeng, Dingshan Yu, Ziming He, Jing Liu, Fang-Xing Xiao, Yan Zhang, Rong Wang, Dibakar Bhattacharyya, Timothy Thatt Yang Tan

Chemical and Materials Engineering Faculty Publications

Covalent bonding of graphene oxide quantum dots (GOQDs) onto amino modified polyvinylidene fluoride (PVDF) membrane has generated a new type of nano-carbon functionalized membrane with significantly enhanced antibacterial and antibiofouling properties. A continuous filtration test using E. coli containing feedwater shows that the relative flux drop over GOQDs modified PVDF is 23%, which is significantly lower than those over pristine PVDF (86%) and GO-sheet modified PVDF (62%) after 10 h of filtration. The presence of GOQD coating layer effectively inactivates E. coli and S. aureus cells, and prevents the biofilm formation on the membrane surface, producing excellent antimicrobial activity and …

Ν = 1/2 Landau Level: Half-Empty Versus Half-Full, Ganpathy Murthy, R. Shankar

Physics and Astronomy Faculty Publications

We show here that an extension of the Hamiltonian theory developed by us over the years furnishes a composite fermion (CF) description of the ν = 1/2 state that is particle-hole (PH) symmetric, has a charge density that obeys the magnetic translation algebra of the lowest Landau level (LLL), and exhibits cherished ideas from highly successful wave functions, such as a neutral quasiparticle with a certain dipole moment related to its momentum. We also a provide an extension away from ν = 1/2, which has the features from ν = 1/2 and implements the PH transformation on the LLL as …

Strain Effects On The Work Function Of An Organic Semiconductor, Yanfei Wu, Annabel R. Chew, Geoffrey A. Rojas, Gjergji Sini, Greg Haugstad, Alex Belianinov, Sergei V. Kalinin, Hong Li, Chad Risko, Jean-Luc Brédas, Alberto Salleo, C. Daniel Frisbie

Chemistry Faculty Publications

Establishing fundamental relationships between strain and work function (WF) in organic semiconductors is important not only for understanding electrical properties of organic thin films, which are subject to both intrinsic and extrinsic strains, but also for developing flexible electronic devices. Here we investigate tensile and compressive strain effects on the WF of rubrene single crystals. Mechanical strain induced by thermal expansion mismatch between the substrate and rubrene is quantified by X-ray diffraction. The corresponding WF change is measured by scanning Kelvin probe microscopy. The WF of rubrene increases (decreases) significantly with in-plane tensile (compressive) strain, which agrees qualitatively with density …

Hydrologic Models, Tyler Mahoney, Carmen T. Agouridis, Richard C. Warner

Agriculture and Natural Resources Publications

Water is a vital part of our everyday lives. Water is necessary for domestic activities such as drinking, cooking and cleaning; agricultural practices such as growing crops and livestock; and industrial uses such as manufacturing and transporting products (Figure 1). Some of our water use is seen, such as when we take a shower. However, most of our water use is hidden, meaning that water was used to make a product although little to no water may be in the product itself. Because water is so important, a branch of science is devoted to its study.

Sediment Fingerprinting, Somsubhra Chattopadhyay, Carmen T. Agouridis, James F. Fox

Agriculture and Natural Resources Publications

Sediment is one of the most common pollutants in waterbodies such as streams, rivers and lakes. Sources of sediment include upland areas, meaning lands above the floodplain, as well as the waterbodies themselves (Figure 1). Human activities that reduce or remove vegetation increase the amount of soil eroded. In the uplands, examples of sediment sources include tilled crop fields, grazed pastures, construction sites, and timber harvesting areas. Along water bodies, the beds and banks erode due to the force of moving water. Streambank erosion, for instance, contributes anywhere from 15 to 90% of the suspended sediment load in streams.

Drought Risk Management For Beef Cattle Farms, Stephen F. Higgins, Lee Moser, Kylie Schmidt

Agriculture and Natural Resources Publications

One of the most challenging aspects of owning and operating any farming operation is dealing with uncertainty. Uncertainty on the farm comes in many forms; livestock health, feed prices, fuel prices, market prices, and weather to name a few. Over the past decade, the prevalence and impact of drought on agriculture has dramatically increased, thus adding further uncertainty to farmers’ decision-making processes. Drought and the associated loss of productivity is a real risk scenario that all farmers must face. With this inherent risk, one must protect their farm and the environment it impacts through a sound decision-making process that factors …

Measuring Discharge In Wadeable Streams, Whitney Cole Blackburn-Lynch, Carmen T. Agouridis, Tyler M. Sanderson

Agriculture and Natural Resources Publications

Streams and rivers are plentiful in Kentucky from small mountain brooks to large rivers such as the Mississippi River along the Commonwealth’s western border and the Ohio River along its northern border (Figure 1). Kentucky has more than 90,000 miles of streams and contains more navigable water than any other state except Alaska. These streams provide important ecological services such as transporting water, sediment and nutrients and providing habitats to aquatic organisms such as fish and macroinvertebrates and terrestrial ones such as deer and birds. Streams also provide societal services, including drinking water, transportation and recreation. Careful management of these …

Grain Sorghum (Milo) Production In Kentucky, Carrie Ann Knott, Edwin L. Ritchey, James R. Martin, Chad Lee, Doug Johnson, Carl Bradley, Sam Mcneill

Agriculture and Natural Resources Publications

Grain sorghum (Sorghum bicolor) (Figure 1) can be used for a variety of purposes including animal feed, unleavened breads, cakes, wallboard, starch, dextrose, brooms, ethanol, high quality wax, and alcoholic beverages. Grain sorghum produced in Kentucky is most commonly used for animal feed and was first grown here in the 1920s. Although acreage in Kentucky has fluctuated considerably over the years, yields have generally exceeded the national average since the 1970s (Figure 2), indicating that grain sorghum is an option for producers interested in diversifying grain crop operations.

Growth Control Of Oxygen Stoichiometry In Homoepitaxial Srtio3 Films By Pulsed Laser Epitaxy In High Vacuum, Ho Nyung Lee, Sung S. Ambrose Seo, Woo Seok Choi, Christopher M. Rouleau

Physics and Astronomy Faculty Publications

In many transition metal oxides, oxygen stoichiometry is one of the most critical parameters that plays a key role in determining the structural, physical, optical, and electrochemical properties of the material. However, controlling the growth to obtain high quality single crystal films having the right oxygen stoichiometry, especially in a high vacuum environment, has been viewed as a challenge. In this work, we show that, through proper control of the plume kinetic energy, stoichiometric crystalline films can be synthesized without generating oxygen defects even in high vacuum. We use a model homoepitaxial system of SrTiO₃ (STO) thin films on …

Photo Highlights Of The 14th Heart Of America Grazing Conference, Heart Of America Grazing Conference

Kentucky Grazing Conference

No abstract provided.

Picking Apples Off The Grazing Tree: How Far Can We Extend The Grazing Season Profitably?, Greg S. Halich

Kentucky Grazing Conference

Will grazing more and feeding less hay always increase profitability? There are many cases where cattle farmers could graze more days profitably. I would guess that more than half the cattlemen in Kentucky and the region could find ways to do so. But the statement is not universally correct and we need to evaluate the specific situation to determine if increasing grazing days will pay off.

Grazing Corn To Maximize Late Summer And Fall Gains, Jeff Lehmkuhler, Eric Vanzant

Kentucky Grazing Conference

Corn is a warm-season grass with a growth pattern dependent on temperatures. Warmer temperatures accelerate growth while cooler temperatures slow maturation. Thermal time is often referred to as Growing Degree Days (GGD) and calculated as GGD = ((Max Temp – Min Temp)/2) – 50 when calculating in Fahrenheit (Nielsen, 2012). In the upper transition zone, corn thrives and is the major planted crop. The warmer temperatures of the summer months combined with adequate precipitation allows this crop to be a potentially high yielding crop.

Native Warm-Season Grasses: Naturally Adapted Productive Pastures, Pat Keyser

Kentucky Grazing Conference

The series of severe droughts between 2007 and 2012 resulted in substantial decreases in cattle numbers – and enterprises – in our region. Some of the impact of these droughts may have been offset if producers in the region had reliable, drought-resilient summer forages. For all of the benefits of tall fescue, it was never meant to provide our summer forage. After all, it is a cool-season grass. What we have been learning about toxicosis in recent years further emphasizes the value of having alternative forages available during summer months.

How Diversity Extends The Grazing Season At Dogwood Farm, Debby Dulworth

Kentucky Grazing Conference

This article was previously published in Cow Country News.

Cattle are a valuable resource these days, in ways that most people, consumers and producers alike, haven’t yet realized. Putting some other resources into making the change for a better grazing system makes sense, especially here in Kentucky, where grass has, in the past, been the basis of a healthy and expansive economy. Grass can once again be the basis for a healthy economy, if enough people with the vision to see its possibilities get involved and make it happen. A truly healthy economy begins with good human health and …

Putting Some Pop Back In Your Crop: Alfalfa In Crop Rotations, Ben M. Goff

Kentucky Grazing Conference

While alfalfa is often recognized as the “Queen of the Forages”, corn may be considered “King of the Crops” and currently ranks as the nation’s largest acreage crop with over 87 million acres. The corn acreage U.S. has continued to increase in recent years for various reasons including greater market demand, a shift towards larger farms that focus on a fewer number of crops, and the development of improved varieties and management practices. According to the U.S. Census of Agriculture, the acreage devoted to corn and soybeans has risen by 64 and 255%, respectively, over the last 30 years, while …

Reduced Or Low Lignin Alfalfa: Advantages For Hay And Grazing, S. Ray Smith

Kentucky Grazing Conference

Lignin is an essential structural component of all land plants. It fills spaces in the cell wall between cellulose, hemicellulose, and pectin. Lignin provides the strength to plants from giant Sequoia trees to alfalfa growing in hay fields. A good analogy is that lignin is like the steel reinforcing rods in concrete. Life on earth would not be possible without lignin to allow plants to grow upright. The limitation for livestock is that lignin is indigestible. Forage breeders have long realized that the quickest way to improve forage quality would be to reduce lignin concentration, but if lignin is reduced …

Grazing Alfalfa: Producer Perspective, Bob Hall

Kentucky Grazing Conference

Scott County native Robert (Bob) Hall, Jr. is a man of many hats. He and his wife Bonnie have embarked on many ventures on their farm including sheep, hogs and tobacco. Hall was born and raised on the farm outside of Georgetown, where he currently resides and operates a stocker operation. Some may recognize Hall for the feed mill he purchased in the 1960’s known as Hallway Feeds. Early in the Mill’s history over 90 percent of their sales were to dairy producers. Now 95 percent of company’s sales go to the equine industry. Hallway Feed is sold and distributed …

'Lacefield Maxqll' Novel Tall Fescue, Timothy D. Phillips

Kentucky Grazing Conference

The goal of deploying novel endophyte strains in tall fescue varieties has been to achieve forage yields, stress tolerance, and persistence similar to toxic endophyte tall fescue varieties (mainly ‘Kentucky 31’ endophyte infected with the common toxic endophyte strain), but with the superior animal performance results seen with endophyte-free tall fescue varieties or other non-toxic forage species (orchardgrass, alfalfa, etc.). In addition to better stand persistence, less weed encroachment has been reported in novel endophyte (and toxic endophyte) tall fescue varieties compared to their endophyte-free versions (Rudgers et al., 2010; Bouton et al., 2002). The improved competitive ability of endophyte-containing …

Soy Hulls: More Than Just A Feed Supplement, Glen E. Aiken, Michael Flythe

Kentucky Grazing Conference

There is approximately 35 million acres of tall fescue in the USA, with most of this acreage being utilized in hay meadows and grazed pastures in a region between the temperate northeast and subtropical southeast and commonly referred to as the Fescue Belt. Popularity of the grass is due to its productivity, persistence, and low cost of management. Unfortunately, a fungal endophyte that infects most plants of tall fescue produces ergot alkaloid toxins that cause a toxicosis in cattle and other grazing livestock. Fescue toxicosis may reduce reproductive performance of cow herds and weaning weights, and reduce post-weaning weight gain …

The Secret Ingredients Of Clover: Biochanin A And Isoflavonoids, Michael Flythe, Glen Aiken, Isabelle Kagan

Kentucky Grazing Conference

It is well known that the value of clover is in nitrogen. Clovers fix their own nitrogen so that an input of nitrate fertilizer is not required. Furthermore, they are rich in protein-nitrogen, and can be used to meet the protein requirements of ruminants. Clovers also contain a class of chemicals called isoflavones, and we have recently discovered evidence that the isoflavones positively influence the way that ruminants digest protein.

Foreword And Conference Information [2016], S. Ray Smith, Krista Lea

Kentucky Grazing Conference

No abstract provided.

Hyperfine Rather Than Spin Splittings Dominate The Fine Structure Of The B 4Σ-–X 4Σ- Bands Of Aic, Dennis J. Clouthier, Aimable Kalume

Chemistry Faculty Publications

Laser-induced fluorescence and wavelength resolved emission spectra of the B ⁴Σ⁻–X ⁴Σ⁻ band system of the gas phase cold aluminum carbide free radical have been obtained using the pulsed discharge jet technique. The radical was produced by electron bombardment of a precursor mixture of trimethylaluminum in high pressure argon. High resolution spectra show that each rotational line of the 0-0 and 1-1 bands of AlC is split into at least three components, with very similar splittings and intensities in both the P- and R-branches. The observed structure was reproduced by assuming b …

Centrality Dependence Of Identified Particle Elliptic Flow In Relativistic Heavy Ion Collisions At √SNn = 7.7–62.4 Gev, L. Adamczyk, James K. Adkins, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, I. Alekseev, A. Aparin, D. Arkhipkin, E. C. Aschenauer, G. S. Averichev, X. Bai, V. Bairathi, A. Banerjee, R. Bellwied, A. Bhasin, A. K. Bhati, P. Bhattarai, J. Bielcik, J. Bielcikova, L. C. Bland, I. G. Bordyuzhin, J. Bouchet, J. D. Brandenburg, A. V. Brandin, I. Bunzarov, J. Butterworth, H. Caines, M. Calderón De La Barca Sánchez, J. M. Campbell, D. Cebra, Renee H. Fatemi, Suvarna Ramachandran

Physics and Astronomy Faculty Publications

Elliptic flow (υ₂) values for identified particles at midrapidity in Au + Au collisions measured by the STAR experiment in the Beam Energy Scan at the Relativistic Heavy Ion Collider at √^s_NN = 7.7– 62.4 GeV are presented for three centrality classes. The centrality dependence and the data at √^s_NN = 14.5 GeV are new. Except at the lowest beam energies, we observe a similar relative υ₂ baryon-meson splitting for all centrality classes which is in agreement within 15% with the number-of-constituent quark scaling. The larger υ₂ for most particles relative …

The Effect Of Root Exudate 7,4'-Dihydroxyflavone And Naringenin On Soil Bacterial Community Structure, Márton Szoboszlay, Alison White-Monsant, Luke A. Moe

Plant and Soil Sciences Faculty Publications

Our goal was to investigate how root exudate flavonoids influence the soil bacterial community structure and to identify members of the community that change their relative abundance in response to flavonoid exudation. Using a model system that approximates flavonoid exudation of Medicago sativa roots, we treated a soil with 7,4′-dihydroxyflavone and naringenin in two separate experiments using three different rates: medium (equivalent to the exudation rate of 7,4′-dihydroxyflavone from M. sativa seedlings), high (10× the medium rate), and low (0.1× the medium rate). Controls received no flavonoid. Soil samples were subjected to ATP assays and 16S rRNA gene amplicon …

Isotropic And Anisotropic Regimes Of The Field-Dependent Spin Dynamics In Sr2Iro4: Raman Scattering Studies, Y. Gim, A. Sethi, Q. Zhao, J. F. Mitchell, Gang Cao, S. L. Cooper

Physics and Astronomy Faculty Publications

A major focus of experimental interest in Sr₂IrO₄ has been to clarify how the magnetic excitations of this strongly spin-orbit coupled system differ from the predictions of an isotropic 2D spin-1/2 Heisenberg model and to explore the extent to which strong spin-orbit coupling affects the magnetic properties of iridates. Here, we present a high-resolution inelastic light (Raman) scattering study of the low-energy magnetic excitation spectrum of Sr₂IrO₄ and Eu-doped Sr₂IrO₄ as functions of both temperature and applied magnetic field. We show that the high-field (H > 1.5 T) in-plane spin dynamics …

The Jcmt Nearby Galaxies Legacy Survey – X. Environmental Effects On The Molecular Gas And Star Formation Properties Of Spiral Galaxies, Angus Mok, C. D. Wilson, J. Golding, B. E. Warren, F. P. Israel, S. Serjeant, J. H. Knapen, José R. Sánchez-Gallego, P. Barmby, G. J. Bendo, E. Rosolowsky, P. Van Der Werf

Physics and Astronomy Faculty Publications

We present a study of the molecular gas properties in a sample of 98 H I – flux selected spiral galaxies within ∼25 Mpc, using the CO J = 3 − 2 line observed with the James Clerk Maxwell Telescope. We use the technique of survival analysis to incorporate galaxies with CO upper limits into our results. Comparing the group and Virgo samples, we find a larger mean H₂ mass in the Virgo galaxies, despite their lower mean H I mass. This leads to a significantly higher H₂ to H I ratio for Virgo galaxies. Combining our data …