Physical Sciences and Mathematics Commons^™

Bunching Effect In Single-Molecule T4 Lysozyme Nonequilibrium Conformational Dynamics Under Enzymatic Reactions, Yuanmin Wang, H. Peter Lu

Chemistry Faculty Publications

The bunching effect, implying that conformational motion times tend to bunch in a finite and narrow time window, is observed and identified to be associated with substrate enzyme complex formation in T4 lysozyme conformational dynamics under enzymatic reactions. Using single-molecule fluorescence spectroscopy, we have probed T4 lysozyme conformational motions under the hydrolysis reaction of polysaccharide of E. coli 13 cell walls by monitoring the fluorescence resonant energy transfer (FRET) between a donor acceptor probe pair tethered to T4 lysozyme domains involving open close hinge-bending motions. On the basis of the single-molecule spectroscopic results, molecular dynamics simulation, and a random walk …

Highly Visible Light Active Tio2-Xnx Heterojunction Photocatalysts, Vinodkumar Etacheri, Michael Seery, Steven Hinder, Suresh Pillai

Articles

Nitrogen doped anatase-rutile heterojunctions are successfully synthesized through an ethylene-diaminetetraacetic acid (EDTA) modified sol-gel process.An FT-IR study of EDTA modified TiO2 gel confirms the existence of an ionic intermediate (as indicated by a Δν value of 233 cm-1).Differential scanning calorimetry (DSC), X-ray diffraction (XRD), and Raman spectroscopy are employed to study the phase evolution, phase purity, and crystallite size of samples. Formations of O-Ti-N and N-Ti-N bonds in calcined samples are confirmed using XPS and FT-IR spectro- scopy. AllEDTAmodified samples show significantly higher visible light photocatalytic activity than the unmodified sample. The most active nitrogen doped heterojunction obtained at 400C …

Σary, Minnesota State University Moorhead, Mathematics Department

Math Department Newsletters

No abstract provided.

Focused Multi-Document Summarization: Human Summarization Activity Vs. Automated Systems Techniques, Quinsulon L. Israel, Hyoil Han, Il-Yeol Song

Computer Sciences and Electrical Engineering Faculty Research

Focused Multi-Document Summarization (MDS) is concerned with summarizing documents in a collection with a concentration toward a particular external request (i.e. query, question, topic, etc.), or focus. Although the current state-of-the-art provides somewhat decent performance for DUC/TAC-like evaluations (i.e. government and news concerns), other considerations need to be explored. This paper not only briefly explores the state-of-the-art in automatic systems techniques, but also a comparison with human summarization activity.

Cluster Solver For Dynamical Mean-Field Theory With Linear Scaling In Inverse Temperature, Ehsan Khatami, C. Lee, Z. Bai, R. Scalettar, M. Jarrell

Faculty Publications

Dynamical mean-field theory and its cluster extensions provide a very useful approach for examining phase transitions in model Hamiltonians and, in combination with electronic structure theory, constitute powerful methods to treat strongly correlated materials. The key advantage to the technique is that, unlike competing real-space methods, the sign problem is well controlled in the Hirsch-Fye (HF) quantum Monte Carlo used as an exact cluster solver. However, an important computational bottleneck remains; the HF method scales as the cube of the inverse temperature, β. This often makes simulations at low temperatures extremely challenging. We present here a method based on determinant …

Quantum Criticality Due To Incipient Phase Separation In The Two-Dimensional Hubbard Model, Ehsan Khatami, K. Mikelsons, D. Galanakis, A. Macridin, J. Moreno, R. Scalettar, M. Jarrell

Faculty Publications

We investigate the two-dimensional Hubbard model with next-nearest-neighbor hopping, t′, using the dynamical cluster approximation. We confirm the existence of a first-order phase-separation transition terminating at a second-order critical point at filling nc(t′) and temperature Tps(t′). We find that as t′ approaches zero, Tps(t′) vanishes and nc(t′) approaches the filling associated with the quantum critical point separating the Fermi liquid from the pseudogap phase. We propose that the quantum critical point under the superconducting dome is the zero-temperature limit of the line of second-order critical points.

Strength And Failure Of Fibrin Fiber Branch Points, Christine C. Helms, E. A. Sparks, C. Der Laughian, Martin Guthold

Physics Faculty Publications

Blood clots form rapidly in the event of vascular injury, to prevent blood loss. They may also form in undesired places, causing heart attacks, strokes, and other diseases. Blood clots can rupture, and fragments of the clotmay lodge in distal blood vessels, causing, for example, ischemic strokes or embolisms. Thus, there has been great interest in understanding the mechanical behavior and failure mechanisms of blood clots and their constituents. To develop a mechanically realistic model of a blood clot, knowledge of the mechanical properties of its constituents is required. The major structural component providing mechanical strength to the clot is …

The Mechanical Properties Of Single Fibrin Fibers, W. Liu, Christine C. Helms, E. A. Sparks, Martin Guthold

Physics Faculty Publications

Background:

Blood clots perform the mechanical task of stemming the flow of blood.

Objectives:

To advance understanding and realistic modeling of blood clot behavior we determined the mechanical properties of the major structural component of blood clots, fibrin fibers.

Methods:

We used a combined atomic force microscopy (AFM)/fluorescence microscopy technique to determine key mechanical properties of single crosslinked and uncrosslinked fibrin fibers.

Results and conclusions:

Overall, full crosslinking renders fibers less extensible, stiffer, and less elastic than their uncrosslinked counterparts. All fibers showed stress relaxation behavior (time-dependent weakening) with a fast and a slow relaxation time, 2 and 52 s. …

Compassion-Focused Reappraisal, Benefit-Focused Reappraisal, And Rumination After An Interpersonal Offense: Emotion-Regulation Implications For Subjective Emotion, Linguistic Responses, And Physiology, Charlotte Vanoyen-Witvliet, Ross W. Knoll, Nova G. Hinman, Paul Deyoung

Faculty Publications

This repeated measures psychophysiology experiment studied three responses to a past interpersonal offense (38 females and 33 males). We compared rumination with two offense reappraisal strategies. Compassion-focused reappraisal emphasized the offender's humanity, and interpreted the transgression as evidence of the offender's need for positive transformation. Benefit-focused reappraisal emphasized insights gained or strengths shown in facing the offense. Supporting the manipulations, compassion-focused reappraisal stimulated the most empathy and forgiveness, whereas benefit-focused reappraisal prompted the most benefit language and gratitude. Both reappraisals decreased aroused, negative emotion, and related facial muscle tension at the brow (corrugator). Both reappraisals increased happiness and positive emotion …

On Probing Human Fingertips In Vivo Using Near-Infrared Light: Model Calculations, Jerry Goodisman, Joseph Chaiken

Chemistry - All Scholarship

We probe volar-side fingertip capillary beds with nearinfrared laser light and collect Raman, Rayleigh, and Mie scattered light and fluorescence. The results are interpreted using radiation transfer theory in the single-scattering approximation. The surface topography of the skin is modeled using the Fresnel equations. The skin is treated as a three-layer material, with a mean-field treatment of tissue composition and related optical properties. The model, with a reasonable choice of tissue parameters, gives a remarkably accurate account of the features of actual measurements. It predicts the optimal values for the incident angle of the laser beam and the distance between …

A Targeted Modeling Study Of The Interaction Between A Supercell And A Preexisting Airmass Boundary, Jennifer M. Laflin

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

It is theorized that supercell thunderstorms account for the majority of significantly severe convective weather which occurs in the United States, and as a result, it is necessary that the mechanisms which tend to produce supercells are recognized and investigated. Airmass boundaries have been identified as a preferred location for supercell development due to the enhanced horizontal vorticity and forced ascent that are found along the boundary. This study examines the specific influence of a preexisting airmass boundary on supercell development through a set of idealized simulations. These simulations are based on a supercell which formed along an outflow boundary …

Distance-Based Measures Of Inconsistency And Incoherency For Description Logics, Yue Ma, Pascal Hitzler

Computer Science and Engineering Faculty Publications

Inconsistency and incoherency are two sorts of erroneous information in a DL ontology which have been widely discussed in ontology-based applications. For example, they have been used to detect modeling errors during ontology construction. To provide more informative metrics which can tell the differences between inconsistent ontologies and between incoherent terminologies, there has been some work on measuring inconsistency of an ontology and on measuring incoherency of a terminology. However, most of them merely focus either on measuring inconsistency or on measuring incoherency and no clear ideas of how to extend them to allow for the other. In this paper, …

Capacity-Driven Pricing Mechanism In Special Service Industries, Lijian Chen, Suraj M. Alexander

MIS/OM/DS Faculty Publications

We propose a capacity driven pricing mechanism for several service industries in which the customer behavior, the price demand relationship, and the competition are significantly distinct from other industries. According our observation, we found that the price demand relationship in these industries cannot be modeled by fitted curves; the customers would neither plan in advance nor purchase the service strategically; and the competition would be largely local. We analyze both risk neutral and risk aversion pricing models and conclude the proposed capacity driven model would be the optimal solution under mild assumptions. The resulting pricing mechanism has been implemented at …

A 3-D Photo Forensic Analysis Of The Lee Harvey Oswald Backyard Photo, Hany Farid

Computer Science Technical Reports

More than forty-five years after the assassination of U.S. President Kennedy theories continue to circulate suggesting that the accused assassin, Lee Harvey Oswald, acted as part of a larger conspiracy. It has been argued, for example, that incriminating photographs of Oswald were manipulated, and hence evidence of a broader plot. We describe a detailed 3-D analysis of the Oswald photos to determine if such claims of tampering are warranted.

A Note On Randomized Streaming Space Bounds For The Longest Increasing Subsequence Problem, Amit Chakrabarti

Computer Science Technical Reports

The deterministic space complexity of approximating the length of the longest increasing subsequence of a stream of N integers is known to be Theta~(sqrt N). However, the randomized complexity is wide open. We show that the technique used in earlier work to establish the Omega(sqrt N) deterministic lower bound fails strongly under randomization: specifically, we show that the communication problems on which the lower bound is based have very efficient randomized protocols. The purpose of this note is to guide and alert future researchers working on this very interesting problem.

Some Trust Issues In Social Networks And Sensor Networks, Krishnaprasad Thirunarayan, Pramod Anantharam, Cory Andrew Henson, Amit P. Sheth

Kno.e.sis Publications

Trust and reputation are becoming increasingly important in diverse areas such as search, e-commerce, social media, semantic sensor networks, etc. We review past work and explore future research issues relevant to trust in social/sensor networks and interactions. We advocate a balanced, iterative approach to trust that marries both theory and practice. On the theoretical side, we investigate models of trust to analyze and specify the nature of trust and trust computation. On the practical side, we propose to uncover aspects that provide a basis for trust formation and techniques to extract trust information from concrete social/sensor networks and interactions. We …

Wind Energy Deployment Issue Brief - May 2010, Erik Edward Nordman

Technical Reports

Wind energy projects have been proposed all over the world. West Michigan coastal communities, like other communities worldwide, are in the midst of assessing the benefits and challenges of siting wind energy farms. These wind energy projects reflect Michigan’s changing mix of potential energy sources; changes that are requiring the attention of all West Michigan communities.

Michigan’s electricity providers consider wind energy to be the most cost effective, scalable means of meeting the state’s 10 percent renewable energy standard [1]. Wind energy enjoys broad support in general, but specific projects can draw opposition [2]. Understanding the factors that influence wind …

Development Of A Discrete Mathematics Textbook And Guide For High School Teachers, Rebecca A. Stokes

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

This project was to create the beginnings a textbook for teacher's to supplement instruction of a discrete mathematics course at the high school level. The development of the text was guided by past and current efforts to place discrete mathematics in high school curriculum. A review of the literature and experiences of instructors were viewed and analyzed to guide the construction of the textbook. The text was written with the goal to give teachers information about the topics of discrete mathematics, extra resources, lesson ideas , and optional worksheets for students. Several lessons were created and one was implemented in …

Results From The April 2009 Gulf Of Alaska Line Transect Survey (Goals) In The Navy Training Exercise Area, B. K. Rone, A. B. Douglas, A. N. Zerbini, L. Morse, A. Martinez, P. J. Clapham, J. Calambokidis

United States Department of Commerce: Staff Publications

Little is known about the present-day occurrence of cetaceans found in offshore waters in the Gulf of Alaska; however, whaling records and a few recent surveys have shown this area to be important habitat. The U.S. Navy maintains a maritime training area in the central Gulf of Alaska, east of Kodiak Island, and has requested additional information on marine mammal presence and use of this area. To describe the occurrence and distribution of marine mammals in and around the U.S. Navy training area, a line transect visual and acoustic survey was conducted 10-20 April 2009 from the NOAA ship Oscar …

A Study Of The Sustainability Of Wild Capture Salmon In The Pacific Northwest, Justin D. Hansen

Social Sciences

No abstract provided.

Ranked Set Sampling Using Auxiliary Variables Of A Randomized Response Procedure For Estimating The Mean Of A Sensitive Quantitative Character, Carlos N. Bouza

Journal of Modern Applied Statistical Methods

The analysis of the behavior of estimators of the mean of a sensitive variable is considered when a randomized response procedure is used. The results deal with the inference based on simple random sampling with replacement study design. A study of the behavior of the procedures for a ranked set sampling design is developed. A gain in accuracy is generally associated with the proposed alternative model.

Derivation Of Mass Independent Quantum Treatment Of Phenomenon, David Parker

Journal of Modern Applied Statistical Methods

The derivation and applications is presented of a spatial variable or spatial radius which is related to the inertia or mass-energy of any quantum body by a Lorentz invariant relation. Mass independent DeBroglie and Schroedinger equations are derived and applied to the resolution of the linguistic incompatibility between quantum theory and the geometrical weak equivalence principle. The equivalence principle is restated in terms of the spatial radius. The gravitational attraction between bodies and the relativistic energy are both presented in terms of the spatial radius follows. The ratio of the gravitational force to the Coulomb force at the Planck scale …

Two-Loop Resummations For Qcd Hard Scattering, Nikolaos Kidonakis

Faculty Articles

I present results for the resummation of soft and collinear gluon contributions to QCD hardscattering cross sections at two loops. This requires the calculation of UV and IR divergences through two loops and the construction of soft anomalous dimensions that control resummation at NNLL. Explicit results are provided for processes that involve massless and/or massive quarks, including single top and top pair production.

Single Top Quark Production And Cross Section At Hadron Colliders, Nikolaos Kidonakis

Faculty Articles

I present results for the theoretical cross section of single top quark production in the s channel and also via associated production with a W boson or a charged Higgs. The calculations include higher-order corrections at NNLL accuracy. Detailed numerical results are provided for Tevatron and LHC energies.

Refuge Update – May/June 2010, Volume 7, Number 3

RefugeUpdate (USFWS-NWRS)

Table of Contents:

After Rehab, Vessel Starts Over in Alaska The latest addition to the Refuge System’s fleet of vessels in Alaska spent much of its life on the wrong side of the law.

In Arizona, Refuges Are Oases for Fish Fish in the desert? Yes. At San Bernardino and Leslie Canyon National Wildlife Refuges, protecting fish is in the establishing mission.

FOCUS: Marine National Monuments The four marine national monuments are among the Refuge System’s most distinctive components. As such, they present special challenges, rare opportunities and unparalleled beauty.

Can You Hear Me Now? Looking for a low-cost way …

Magnetic Transition In The Rare Earth Intermetallic Compound [Formula Omitted]: Heat Capacity And Neutron Diffraction Studies, R. Nirmala, A. V. Morozkin, Jagat Lamsal, William B. Yelon, S. K. Malik

Physics Faculty Research & Creative Works

Polycrystalline Ce₅Ge₄ compound (orthorhombic Sm₅Ge₄ -type structure, space group Pnma, No. 62) orders ferromagnetically at ~12 K (Tc). Low field dc magnetization and ac magnetic susceptibility data reveal presence of competing magnetic interactions below Tc. Heat capacity of Ce₅Ge₄ in zero applied field indicates a second order transition with a peak centered at 11 K. Powder neutron diffraction studies confirm the existence of a commensurate magnetic order in this compound at 10 K without a change of crystal structure. the Ce moments lie in the ab plane and the moment …

Diffusion Monte Carlo Studies Of Quantum Solvation: Finding Nodal Functions Of Wavefunctions Using A Genetic Algorithm, Christina Hansen Howell

Undergraduate Honors Capstone Projects

Solvation is important in many chemical reactions since most reactions occur in solution. Recently, progress has been made using helium-4 nanodroplets as the solvent at temperatures close to absolute zero. Because helium-4 is a superfluid it solvates dissolved molecules much differently that does a conventional solvent. This opens up the possibility of performing new types of chemistry in the superfluid environment. However, the nature of the interaction of the dissolved species with the solvent remains poorly understood. The basic question to be answered in this project is: how does the quantum solvent perturb the rotational dynamics of the solute particles? …

Bracketing The Age Of The Great Gallery Rock Art Panel In Horseshoe Canyon, Utah By Osl Dating Of Associated Alluvial Terraces, Melissa S. Jackson

Undergraduate Honors Capstone Projects

Barrier Canyon Style rock art (BCS) is a unique rock art style indigenous to the middle Colorado Plateau that is of an unknown age and formed by a combination of wall preparation, rock pecking, and application of multiple pigments. It is characterized by broad-shouldered, mummy-like figures that commonly lack limbs and facial details but are accompanied by animated and realistic representations of animals. The age of BCS art remains unknown in spite of attempts to radiocarbon date accessory brush fibers in the mineral-based pigment. Yet a range of age hypotheses exist, from as young as 1600 AD to as old …

Investigating Two-Photon Double Ionization Of D₂ By Xuv-Pump-Xuv-Probe Experiments, Yuhai Jiang, Artem Rudenko, Jhon Fredy Perez-Torres, Oliver Herrwerth, Lutz M. Foucar, Moritz Kurka, Kai Uwe Kuhnel, M. Toppin, Etienne Plesiat, Felipe Morales, Fernando Javier Martin, Matthias Lezius, Matthias F. Kling, Till Jahnke, Reinhard Dorner, Jose Luis Sanz-Vicario, Jeroen Van Tilborg, Ali Belkacem, Michael Schulz, Kiyoshi Ueda, Stefan Dusterer, Rolf Treusch, Claus Dieter Schroter, Robert Moshammer, Joachim Hermann Ullrich

Physics Faculty Research & Creative Works

We used a split-mirror setup attached to a reaction microscope at the free-electron laser in Hamburg (FLASH) to perform an XUV-pump-XUV-probe experiment by tracing the ultrafast nuclear wave-packet motion in the D2 ⁺(1sσg) with <10 fs time resolution. Comparison with time-dependent calculations shows excellent agreement with the measured vibrational period of 22±4 fs in D2⁺, points to the importance of accurately knowing the internuclear distance-dependent ionization probability, and paves the way to control sequential and nonsequential two-photon double-ionization contributions.

Investigation Of Novel Quasiliving Polyisobutylene Chain-End Functionalization (Quenching) Methods, David Lee Morgan

Dissertations

This volume recounts efforts toward the development and understanding of chain functionalization techniques involving the direct addition of nucleophiles to quasiliving polyisobutylene (PIB). Nucleophiles included in the study were sterically hindered organic bases, (di)sulfides, N-substituted pyrroles, and alkoxybenzenes. A kinetic investigation of the end-quenching of TiCl4-catalyzed quasiliving PIB with sterically hindered amines was used to determine the mode of interaction with TiCl4 and the active species responsible for -proton abstraction. 2,5-disubstituted-N-hydropyrroles formed pyrrole-TiCl3 adducts that were active in formation of exo-olefin chain ends; whereas, with other sterically hindered amines, only an equilibrium fraction of the amine that did not complex …