Physical Sciences and Mathematics Commons^™

Acrb Trimer Stability And Efflux Activity, Insight From Mutagenesis Studies, Linliang Yu, Wei Lu, Yinan Wei

Chemistry Faculty Publications

The multidrug transporter AcrB in Escherichia coli exists and functions as a homo-trimer. The assembly process of obligate membrane protein oligomers, including AcrB, remains poorly understood. In a previous study, we have shown that individual AcrB subunit is capable of folding independently, suggesting that trimerization of AcrB follows a three-stage pathway in which monomers first fold, and then assemble. Here we destabilized the AcrB trimer through mutating a single Pro (P223) in the protruding loop of AcrB, which drastically reduced the protein activity. We replaced P223 separately with five residues, including Ala, Val, Tyr, Asn, and Gly, and found that …

Exploration And Comparison Of Methods For Combining Population- And Family-Based Genetic Association Using The Genetic Analysis Workshop 17 Mini-Exome, David W. Fardo, Anthony R. Druen, Jinze Liu, Lucia Mirea, Claire Infante-Rivard, Patrick Breheny

Biostatistics Faculty Publications

We examine the performance of various methods for combining family- and population-based genetic association data. Several approaches have been proposed for situations in which information is collected from both a subset of unrelated subjects and a subset of family members. Analyzing these samples separately is known to be inefficient, and it is important to determine the scenarios for which differing methods perform well. Others have investigated this question; however, no extensive simulations have been conducted, nor have these methods been applied to mini-exome-style data such as that provided by Genetic Analysis Workshop 17. We quantify the empirical power and false-positive …

Organometallic Acene Complexes For Electronics Applications, Ilya Vinogradov

Kaleidoscope

No abstract provided.

Taking “Grazing” To The Next Level, Edward N. Ballard

Kentucky Grazing Conference

Since the late 1980’s, producer awareness of pasture management has been increasing. A number of factors have brought this about. Mainly, economic conditions have forced producers to look at their bottom line and this has reflected the low returns from mismanagement of forages and pastures. Also, advancements in the technology of pasture management and improvement have made more intensive utilization of the forage resource more economically viable. Advances in equipment, especially fencing and water equipment, have also helped bring about the increased interest in better grassland management.

My Grazing Experience: Reflections And Observations, Russell C. Hackley

Kentucky Grazing Conference

My pastures are utilized by a beef operation consisting primarily of a small cow/calf herd (30 cows), and a stocker operation numbering from 300-350 head annually, which are grazed only, from spring until fall. These stockers are purchased, continental breed calves, weighing from 500-550 pounds. In the fall, they are sold to Laura’s Lean Beef, usually at a forward contracted price after adding 300 pounds of gain. Occasionally, the stocking includes calves not eligible for Laura’s Lean which are then sold in truckload lots through internet sales.

Options For Getting Water In Every Paddock, Kevin Laurent

Kentucky Grazing Conference

Whether you call it rotational grazing, intensive grazing or management intensive grazing, the economic benefits of controlling how and where your cattle graze are well documented. Increased forage utilization, greater stocking rates, greater legume persistence, reduced hay feeding and more uniform nutrient recycling are just some of the many benefits producers can take advantage of when practicing some form of controlled grazing. However, one of the greatest challenges to implementing a controlled grazing system is the delivery of stock water to the grazing animal.

Stockpiling Tall Fescue: Cost & Return, Greg S. Halich

Kentucky Grazing Conference

An opportunity that Kentucky cattle farmers have in reducing their hay requirements is to apply nitrogen on select pastures to stockpile for fall and winter grazing. By increasing the total pasture production during this time period, the grazing season can be extended and the amount of hay required can be reduced.

Ryzup Smartgrass: Growth Promotion For Forages, S. Ray Smith

Kentucky Grazing Conference

Whenever we discuss grazing management we emphasize how proper grazing will produce the maximum amount of plant growth. Giving forage plants an adequate rest period after each grazing event is essential to allow growth and storage of carbohydrates for the next growth cycle. With grasses, leaving leaf area after grazing allows the plant to maintain photosynthesis and regrow faster. On a more basic level though, all plants regulate growth with hormones. These hormones are termed “plant growth regulators.” Auxin controls cell division and the direction of plant growth. Gibberellic acid (abbrev. GA) has three main functions in plants: 1) stimulate …

Benefits Of "Improved" Grazing--More Important Now Than Ever!, Garry D. Lacefield

Kentucky Grazing Conference

At this Conference twelve years ago I talked about the “Benefits of Improved Grazing”. We have had aspects of that theme at every Kentucky Grazing Conference since and also emphasized that message at 10 Heart of America Grazing Conferences and three National Grazing Conferences. With all that emphasis, why do I bring this up again and even have the nerve to say “More Important Now than Ever”? Well, the short answer is “things are different now!”

Foreword And Kfgc Award Winners [2011], Garry D. Lacefield, Christi L. Forsythe

Kentucky Grazing Conference

No abstract provided.

Critical Differences And Clues In Eta Car's 2009 Event, Andrea Mehner, Kris Davidson, John C. Martin, Roberta M. Humphreys, Kazunori Ishibashi, Gary J. Ferland

Physics and Astronomy Faculty Publications

We monitored Eta Carinae with the Hubble Space Telescope WFPC2 and Gemini GMOS throughout the 2009 spectroscopic event, which was expected to differ from its predecessor in 2003. Here we report major observed differences between events and their implications. Some of these results were quite unexpected. (1) The UV brightness minimum was much deeper in 2009. This suggests that physical conditions in the early stages of an event depend on different parameters than the "normal" inter-event wind. Extra mass ejection from the primary star is one possible cause. (2) The expected He II λ4687 brightness maximum was followed several weeks …

Bankfull Hydraulic Geometry Relationships For The Inner And Outer Bluegrass Regions Of Kentucky, Carmen Agouridis, Ruth Roseann Brockman, Stephen R. Workman, Lindell E. Ormsbee, Alex Fogle

Biosystems and Agricultural Engineering Faculty Publications

Bankfull hydraulic geometry relationships relate bankfull stream dimensions, such as cross-sectional area, width, mean depth, mean velocity, width to depth ratio, and slope to bankfull discharge. These relationships can assist in determining a design discharge for stream restoration and management projects. This study assessed 27 stable streams located in the Inner Bluegrass and Outer Bluegrass regions of Kentucky. Reaches were selected based on the presence of a U.S. Geological Survey gage, as well as other conditions such as presence of readily identifiable bankfull indicators, stability indices, and site accessibility. Bankfull channel dimensions and discharges were determined, and hydraulic geometry relationships …

Rna Oxidation Adducts 8-Ohg And 8-Oha Change With Aβ42 Levels In Late-Stage Alzheimer's Disease, Adam M. Weidner, Melissa A. Bradley, Tina L. Beckett, Dana M. Niedowicz, Amy L.S. Dowling, Sergey V. Matveev, Harry Levine, Mark A. Lovell, M. Paul Murphy

Sanders-Brown Center on Aging Faculty Publications

While research supports amyloid-β (Aβ) as the etiologic agent of Alzheimer's disease (AD), the mechanism of action remains unclear. Evidence indicates that adducts of RNA caused by oxidation also represent an early phenomenon in AD. It is currently unknown what type of influence these two observations have on each other, if any. We quantified five RNA adducts by gas chromatography/mass spectroscopy across five brain regions from AD cases and age-matched controls. We then used a reductive directed analysis to compare the RNA adducts to common indices of AD neuropathology and various pools of Aβ. Using data from four disease-affected brain …

Star Formation In Self-Gravitating Disks In Active Galactic Nuclei. I. Metallicity Gradients In Broad-Line Regions, Jian-Min Wang, Jun-Qiang Ge, Chen Hu, Jack A. Baldwin, Yan-Rong Li, Gary J. Ferland, Fei Xiang, Chang-Shuo Yan, Shu Zhang

Physics and Astronomy Faculty Publications

It has been suggested that the high metallicity generally observed in active galactic nuclei (AGNs) and quasars originates from ongoing star formation in the self-gravitating part of accretion disks around supermassive black holes (SMBHs). We designate this region as the star-forming (SF) disk, in which metals are produced from supernova explosions (SNexp) while at the same time inflows are driven by SNexp-excited turbulent viscosity to accrete onto the SMBHs. In this paper, an equation of metallicity governed by SNexp and radial advection is established to describe the metal distribution and evolution in the SF disk. We find that the metal …

Galaxy Formation In Heavily Overdense Regions At Z ~ 10: The Prevalence Of Disks In Massive Halos, Emilio Romano-Díaz, Jun-Hwan Choi, Isaac Shlosman, Michele Trenti

Physics and Astronomy Faculty Publications

Using a high-resolution cosmological numerical simulation, we have analyzed the evolution of galaxies at z ~ 10 in a highly overdense region of the universe. These objects could represent the high-redshift galaxies recently observed by the Hubble's Wide Field Camera 3 and could as well be possible precursors of QSOs at z ~ 6-7. To overcome the sampling and resolution problems in cosmological simulations of these rare regions, we have used the constrained realizations method. Our main result for z ~ 10 shows the high-resolution central region of 3.5 h^–1 Mpc radius in comoving coordinates being completely dominated by …

Structure And Feedback In 30 Doradus. Ii. Structure And Chemical Abundances, E. W. Pellegrini, J. A. Baldwin, Gary J. Ferland

Physics and Astronomy Faculty Publications

We use our new optical-imaging and spectrophotometric survey of key diagnostic emission lines in 30 Doradus, together with CLOUDY photoionization models, to study the physical conditions and ionization mechanisms along over 4000 individual lines of sight at points spread across the face of the extended nebula, out to a projected radius 75 pc from R136 at the center of the ionizing cluster NGC 2070. We focus on the physical conditions, geometry, and importance of radiation pressure on a point-by-point basis, with the aim of setting observational constraints on important feedback processes. We find that the dynamics and large-scale structure of …

N Ii Λλ5668−5712: A New Class Of Spectral Features In Eta Carinae, Andrea Mehner, Kris Davidson, Gary J. Ferland

Physics and Astronomy Faculty Publications

We report on the N II λλ5668-5712 emission and absorption lines in the spectrum of η Carinae. Spectral lines of the stellar wind regions can be classified into four physically distinct categories: (1) low-excitation emission such as H I and Fe II, (2) higher-excitation He I features, (3) the N II lines discussed in this paper, and (4) He II emission. These categories have different combinations of radial velocity behavior, excitation processes, and dependences on the secondary star. The N II lines are the only known features that originate in "normal" undisturbed zones of the primary wind but depend primarily …

Follow-Up Testing In Functional Anova, Olga A. Vsevolozhskaya, Mark C. Greenwood

Olga A. Vsevolozhskaya

Functional analysis of variance involves testing for differences in functional means across k groups in n functional responses. If a significant overall difference in the mean curves is detected, one may want to identify the location of these differences. Two different follow-up testing methods are discussed and contrasted. A point-wise test proposed by Cox and Lee (2008) is compared to a test based on regions of the functional domain. The methods are contrasted in terms of weak control of the family-wise error rate, strong control of the family-wise error rate, and power.

Torus And Active Galactic Nucleus Properties Of Nearby Seyfert Galaxies: Results From Fitting Infrared Spectral Energy Distributions And Spectroscopy, Almudena Alonso-Herrero, Almeida Cristina Ramos, Rachel Mason, Ramos Andrés Asensio, Patrick F. Roche, Nancy A. Levenson, Moshe Elitzur, Christopher Packham, José Miguel Rodríguez Espinosa, Stuart Young, Tanio Díaz-Santos, Ana M. Pérez-García

Physics and Astronomy Faculty Publications

We used the CLUMPY torus models and a Bayesian approach to fit the infrared spectral energy distributions and ground-based high angular resolution mid-infrared spectroscopy of 13 nearby Seyfert galaxies. This allowed us to put tight constraints on torus model parameters such as the viewing angle i, the radial thickness of the torus Y, the angular size of the cloud distribution σ_torus, and the average number of clouds along radial equatorial rays N₀. We found that the viewing angle i is not the only parameter controlling the classification of a galaxy into type 1 or …

The Dark Side Of Qso Formation At High Redshifts, Emilio Romano-Díaz, Isaac Shlosman, Michele Trenti, Yehuda Hoffman

Physics and Astronomy Faculty Publications

Observed high-redshift QSOs, at z ~ 6, may reside in massive dark matter (DM) halos of more than 10¹² M_☉ and are thus expected to be surrounded by overdense regions. In a series of 10 constrained simulations, we have tested the environment of such QSOs. The usage of constrained realizations has enabled us to address the issue of cosmic variance and to study the statistical properties of the QSO host halos. Comparing the computed overdensities with respect to the unconstrained simulations of regions empty of QSOs, assuming there is no bias between the DM and baryon distributions, and …

Gene Set Analysis For Longitudinal Gene Expression Data, Ke Zhang, Haiyan Wang, Arne C. Bathke, Solomon W. Harrar, Hans-Peter Piepho, Youping Deng

Statistics Faculty Publications

BACKGROUND: Gene set analysis (GSA) has become a successful tool to interpret gene expression profiles in terms of biological functions, molecular pathways, or genomic locations. GSA performs statistical tests for independent microarray samples at the level of gene sets rather than individual genes. Nowadays, an increasing number of microarray studies are conducted to explore the dynamic changes of gene expression in a variety of species and biological scenarios. In these longitudinal studies, gene expression is repeatedly measured over time such that a GSA needs to take into account the within-gene correlations in addition to possible between-gene correlations.

RESULTS: We provide …

Biofilter Media Characterization Using Water Sorption Isotherms, Guilherme Del Nero Maia, George B. Day, Richard S. Gates, Joseph L. Taraba

Biosystems and Agricultural Engineering Faculty Publications

Compost material has been used extensively as a gas‐phase biofilter media for contaminant gas treatment in recent years. One of the biggest challenges in the use of this type of material is adequate control of compost moisture content and understanding its effect on the biofiltration process. The present work provides a methodology for characterization of biofilter media under low moisture conditions. Results indicated that low levels of equilibrium moisture content (EMC) were obtained for high levels of equilibrium relative humidity (ERH), i.e., 99% ERH produced EMC of approximately 20% (dry basis) at 25° C. Most bacteria struggle to survive in …

Numerical Modeling Of The Cn Spectral Emission Of The Stardust Re-Entry Vehicle, Alexandre Martin, Erin D. Farbar, Iain D. Boyd

Mechanical Engineering Faculty Publications

Re-entry vehicles designed for space exploration are usually equipped with thermal protection systems made of ablative material. In order to properly model and predict the aerothermal environment of the vehicle, it is imperative to account for the gases produced by ablation processes. In the case of charring ablators, where an inner resin is pyrolyzed at a relatively low temperature, the composition of the gas expelled into the boundary layer is complex and may lead to thermal chemical reactions that cannot be captured with simple ow chemistry models. In order to obtain better predictions, an appropriate gas ow chemistry model needs …

A Survey Of Molecular Hydrogen In The Crab Nebula, E. D. Loh, J. A. Baldwin, Z. K. Curtis, Gary J. Ferland, C. R. O'Dell, A. C. Fabian, Philippe Salomé

Physics and Astronomy Faculty Publications

We have carried out a near-infrared, narrowband imaging survey of the Crab Nebula, in the H₂ 2.12 μm and Brγ 2.17 μm lines, using the Spartan Infrared camera on the SOAR Telescope. Over a 2.8 × 5'.1 area that encompasses about 2/3 of the full visible extent of the Crab, we detect 55 knots that emit strongly in the H₂ line. We catalog the observed properties of these knots. We show that they are in or next to the filaments that are seen in optical-passband emission lines. Comparison to Hubble Space Telescope [S …

Physical Conditions In Barnard's Loop, Components Of The Orion-Eridanus Bubble, And Implications For The Warm Ionized Medium Component Of The Interstellar Medium, C. R. O'Dell, Gary J. Ferland, R. L. Porter, P. A. M. Vanhoof

Physics and Astronomy Faculty Publications

We have supplemented existing spectra of Barnard's Loop with high accuracy spectrophotometry of one new position. Cloudy photoionization models were calculated for a variety of ionization parameters and stellar temperatures and compared with the observations. After testing the procedure with recent observations of M43, we establish that Barnard's Loop is photoionized by four candidate ionizing stars, but agreement between the models and observations is only possible if Barnard's Loop is enhanced in heavy elements by about a factor of 1.4. Barnard's Loop is very similar in properties to the brightest components of the Orion-Eridanus Bubble and the warm ionized medium …

Emission From Hot Dust In The Infrared Spectra Of Gamma-Ray Bright Blazars, Michael P. Malmrose, Alan P. Marscher, Svetlana G. Jorstad, Robert Nikutta, Moshe Elitzur

Physics and Astronomy Faculty Publications

A possible source of γ-ray photons observed from the jets of blazars is inverse Compton scattering by relativistic electrons of infrared seed photons from a hot, dusty torus in the nucleus. We use observations from the Spitzer Space Telescope to search for signatures of such dust in the infrared spectra of four γ-ray bright blazars, the quasars 4C 21.35, CTA102, and PKS 1510-089, and the BL Lacertae object ON231. The spectral energy distribution (SED) of 4C 21.35 contains a prominent infrared excess indicative of dust emission. After subtracting a non-thermal component with a power-law spectrum, we fit a …

Poster Session, Kentucky Water Resources Research Institute, University Of Kentucky

Kentucky Water Resources Annual Symposium

• Fate of Stable Isotope Label During Predation of 15N-Tagged Wild-Type Escherichia coli by Protozoa, Ashley Barton and Alan Fryar, Dept Earth and Environmental Sciences, UK
• Cane Run Watershed Assessment and Restoration – Phase One Accomplishments, Amanda Gumbert and others, UK Cooperative Extension Service
• Improving Water Quality: Riparian Edge versus River Channel, Renee Kirtman and Kristy Hopfensperger, Biological Sciences, Northern Kentucky University
• Microscopic Population Dynamics and their Relationships to the Activated Sludge Process in a 30 MGD Wastewater Treatment Plant, Maria Lundin and David Price, LFUCG Division of Water Quality
• Southern Region Down-Well Camera Project, Glynn …

Session 2d, Kentucky Water Resources Research Institute, University Of Kentucky

Kentucky Water Resources Annual Symposium

• Water Quality Credit Trading Feasibilities for Kentucky, Marie Pelton and others, Dept of Agricultural Economics, UK
• Participation in Agricultural Governmental Cost Share Programs in the Kentucky River Watershed in the Context of Water Quality Trading, Pedro Fernandes da Costa and others, Dept of Agricultural Economics, UK
• Point Source Polluters in the Kentucky River Watershed and the Potential for Water Quality Trading, Ron Childress and others, Dept of Agricultural Economics, UK
• Nonpoint Source Abatement Costs in the Kentucky River Watershed, Zheng Liu and others, Dept of Agricultural Economics, UK

Session 2c, Kentucky Water Resources Research Institute, University Of Kentucky

Kentucky Water Resources Annual Symposium

• Comparing the Kentucky Phosphorus Index with the P Loss Calculated with a Process-Based Model, Carl Bolster, USDA-ARS, AWMRU, Bowling Green, KY
• Kentucky Nutrient Criteria Development and Reduction Strategy, Clark Dorman, Water Quality Branch, KY DOW
• Genotypic Diversity of Escherichia coli Isolates from Environmental Sources and the Influence on Transport Behavior, Kimberly Cook and others, USDA-ARS, AWMRU, Bowling Green, KY
• A Multiparameter Approach for the Identification of Leaking and Overflowing Sanitary Sewers in the Wolf Run Watershed, Tricia Coakley and Gail Brion, Depts of Earth and Environmental Sciences and Civil Engineering, UK

Session 2b, Kentucky Water Resources Research Institute, University Of Kentucky

Kentucky Water Resources Annual Symposium

• Building Support for Protecting and Restoring Plain, Frumpy, Dowdy Streams, Barry Tonning, Tetra Tech, Mt. Sterling, KY
• Monitoring Water Quality in Hinkston Creek: Providing Information for Action, Brian Reeder and April Haight, Center for Environmental Education, Morehead State University
• The Story of the Hinkston Creek Watershed Data, Gregory Sousa and others, Tetra Tech
• Implementation of Watershed Based Plans in the Dix River Watershed, Caroline Walz and Malissa McAlister, OSM/VISTA Dix River Watershed Coordinator and KWRRI