Physical Sciences and Mathematics Commons^™

On Searching Compressed String Collections Cache-Obliviously, Ankur Gupta, Paolo Ferragina, Roberto Grossi, Rahul Shah, Jeffrey Vitter

Ankur Gupta

The Development Of Novel Therapeutics For Sickle-Cell Disease, Brian Brennan, Sara Costello, '10, Steven Sturlis, '10

Brian B. Brennan

No abstract provided.

The Expression Of Recombinant Hemoglobin In Escherichia Coli, Brian Brennan, Christopher Miedema, '10, Evan Mason, '10

Brian B. Brennan

No abstract provided.

Constant-Time Query Processing, Vijayshankar Raman, Garret Swart, Lin Qiao, Frederick Reiss, Vijay Dialani, Donald Kossmann, Inderpal Narang, Richard Sidle

Vijay Dialani

Query performance in current systems depends significantly on tuning: how well the query matches the available indexes, materialized views etc. Even in a well tuned system, there are always some queries that take much longer than others. This frustrates users who increasingly want consistent response times to ad hoc queries. We argue that query processors should instead aim for constant response times for all queries, with no assumption about tuning. We present Blink, our first attempt at this goal, that runs every query as a table scan over a fully denormalized database, with hash group-by done along the way. …

How To Pick Out The Integers In The Rationals: An Application Of Number Theory To Logic, Daniel Flath, Stan Wagon

Stan Wagon, Retired

No abstract provided.

Selective Formation Of A Symmetric Sc3n@C78 Bisadduct:  Adduct Docking Controlled By An Internal Trimetallic Nitride Cluster, Ting Cai, Liaosa Xu, Chunying Shu, Hunter Champion, Jonathan Reid, Clemins Anklin, Mark Anderson, Harry Gibson, Harry Dorn

Mark R. Anderson

In this paper we report a regioselective Bingel−Hirsch reaction of Sc3N@C78 yielding a single mono- and a dominate bis-ethyl malonate derivative for the first time. The Cs-symmetric monoadduct 1 and C2v-symmetric bisadduct 2 were isolated by HPLC and characterized by MS, UV−vis, and NMR spectroscopy. The symmetric bisadduct 2 clearly demonstrate the remarkable regioselectivity control exerted by the encapsulated Sc3N cluster. We have employed a LUMO electron density surface computational approach to predict multiadduct docking sites on the ellipsoidal fullerene cage surface.

Cracking And Crumbling: Exploring Mechanisms Of Dike Emplacement, Teaching Structural Geology In The 21st Century, Resources For Teaching Structural Geology, Phillip Resor

Phillip G Resor

No abstract provided.

'Partial Derivatives: Are You Kidding?': Teaching Thermodynamics Using Virtual Substance, Chrystal Bruce, Carribeth Bliem, John Papanikolas

Chrystal D. Bruce

No abstract provided.

Single-Cell Printing To Form Three-Dimensional Lines Of Olfactory Ensheathing Cells, Christina Othon, Xingjia Wu, Juanita Anders, Bradley Ringeisen

Christina M Othon

Biological laser printing (BioLP™) is a unique tool capable of printing high resolution two- and three-dimensional patterns of living mammalian cells, with greater than 95% viability. These results have been extended to primary cultured olfactory ensheathing cells (OECs), harvested from adult Sprague-Dawley rats. OECs have been found to provide stimulating environments for neurite outgrowth in spinal cord injury models. BioLP is unique in that small load volumes (~µLs) are required to achieve printing, enabling low numbers of OECs to be harvested, concentrated and printed. BioLP was used to form several 8 mm lines of OECs throughout a multilayer hydrogel scaffold. …

Highly Fluorous Bidentate Phosphines, Brad Berven, George Koutsantonis

Brad Berven

The reaction of tetrachlorodiphosphines [Cl2P(CH2)nPCl2; n = 2-4] with fluorous aromatic precursors 4-bromo(perfluorohexyl)benzene and 4-(perfluorohexyl)phenol gave a series of fluorous-tagged diphosphines [(p-C6F13C6H4)2P(CH2)nP(C6H4C6F13-p)2; n = 2-4] and a new diphosphonite [(p-C6F13C6H4O)2P(CH2)3P(OC6H4C6F13-p)2]. The improved synthesis of 1,3-bis(dichlorophosphino)propane (dcpp), involved the facile chlorination of the corresponding primary phosphine with triphosgene. Fluorinated diimines RN=C(CH3)C(CH3)=NR, where R = p-C6H4C6F13 or p-C6H4C8F17 have also been prepared, and were found to be air-stable alternatives to the highly air-sensitive phosphorus-containing ligands. All compounds were characterised by a variety of techniques including NMR, IR, MS and microanalysis. The successful reduction of the phosphine-oxides [(p-C6F13C6H4)2P(O)(CH2)nP(O)(C6H4C6F13-p)2; n = 2,3] with phenylsilane …

Evolution Of Higher-Order Gray Hirota Solitary Waves, Tim Marchant

Tim Marchant

The defocusing Hirota equation has dark and gray soliton solutions which are stable on a background of periodic waves of constant amplitude. In this paper, gray solitary wave evolution for a higher-order defocusing Hirota equation is examined. A direct analysis is used to identify families of higher-order gray Hirota solitary waves, which are embedded for certain parameter values. Soliton perturbation theory is used to detmine the detailed behavior of an evolving higher-order gray Hirota solitary wave. An integral expression for the first-order correction to the wave is found and analytical expressions for the steady-state and transient components of the solitary …

Effect Of Statins On Serum Apolipoprotein J And Paraoxonase-1 Levels In Patients With Ischemic Heart Disease Undergoing Coronary Angiography, Mark Wilson, Dimitri Mikhailidis, Maria Poulakou, Despina Perrea, Kosmas Paraskevas, Dimitrios Iliopoulos, Serafim Tsitsilonis, Ioannis Vlachos, Sonia-Athena Karabina

Mark R Wilson

No abstract provided.

Carotenoid Intake Does Not Mediate A Relationship Between Reactive Oxygen Species And Bright Colouration: Experimental Test In A Lizard, Mark Wilson, Mats Olsson, Tobias Uller, Caroline Isaksson, Beth Mott

Mark R Wilson

No abstract provided.

Free Radicals Run In Lizard Families, Mark Wilson, Mats Olsson, Tobias Uller, Caroline Isaksson, Beth Mott, Mo Healey, Wanger Thomas

Mark R Wilson

No abstract provided.

Mathematical Modelling Of Nematicons And Their Interactions, Prof. Tim Marchant

Tim Marchant

The mathematical modelling of guided wave (nematicon) propagation in liquid crystals is considered. Model equations are derived based on suitable trial functions in an averaged Lagrangian. These equations are used to model nematicon interactions.

Undular Bores And The Initial-Boundary Value Problem For The Modified Korteweg-De Vries Equation, Tim Marchant

Tim Marchant

Two types of analytical undular bore solutions, of the initial value problem for the modified Korteweg-de Vries (mKdV), are found. The first, an undular bore composed of cnoidal waves, is qualitatively similar to the bore found for the KdV equation, with solitons occurring at the leading edge and small amplitude linear waves occurring at the trailing edge. The second, a newly identified type of undular bore, consists of finite amplitude sinusiodal waves, which have a rational form. At the leading edge is the mKdV algebraic soliton, while, again, small amplitude linear waves occur at the trailing edge. The initial-boundary value …

Collisionless Shock Resolution In Nematic Liquid Crystals, Tim Marchant

Tim Marchant

The diffractive resolution on a collisionless shock formed along the spatial profile of a beam in a nematic liquid crystal is considered, this material being an example of a self-focusing, nonlocal medium. It is found that the shock is resolved through the formation of an undular bore structure which persists for experimentally relevant propagation distances due to nonlocality delaying the onset of modulational instability. Both 1+1 and 2+1 dimensional bores with circular symmetry are considered (termed line and circular bores, respectively). A semianalytical solution is developed for the line undular bore, approximating it as a train of uniform solitary waves. …

Semi-Analytical Solutions For A Gray-Scott Reaction-Diffusion Cell With An Applied Electric Field, Tim Marchant

Tim Marchant

An ionic version of the Gray–Scott chemical reaction scheme is considered in a reaction–diffusion cell, with an applied electric field, which causes migration of the reactant and autocatalyst in a preferred direction. The Galerkin method is used to reduce the governing partial differential equations to an approximate model consisting of ordinary differential equations. This is accomplished by approximating the spatial structure of the reactant and autocatalyst concentrations. Bifurcation analysis of the semi-analytical model is performed by using singularity theory to analyse the static multiplicity and a stability analysis to determine the dynamic multiplicity. The application of the electric field causes …

Environmentally Friendly Organic Synthesis Using Bismuth Compounds. Bismuth Trifluoromethanesulfonate-Catalyzed Allylation Of Dioxolanes, Ram Mohan, Matthew Spaffpord, James Christensen, Matthew Huddle, Joshua Lacey

Ram S. Mohan

A bismuth trifluoromethanesulfonate (triflate)-catalyzed (2.0 mol-%) multicomponent reaction involving the allylation of dioxolanes followed by in situ derivatization with anhydrides to generate highly functionalized esters has been developed under solvent-free conditions. Most reagents used to date for allylation of dioxolanes are highly corrosive and are often required in stoichiometric amounts. In contrast, the use of a relatively non-toxic and non-corrosive bismuth(iii)-based catalyst makes this methodology especially attractive for scale-up.

Intrinsic Linking And Knotting Are Arbitrarily Complex, Ramin Naimi, Erica Flapan, Blake Mellor

Ramin Naimi

We show that, given any $n$ and $\alpha$, every embedding of any sufficiently large complete graph in $\mathbb{R}^3$ contains an oriented link with components $Q_1$, ..., $Q_n$ such that for every $i\not =j$, $|\lk(Q_i,Q_j)|\geq\alpha$ and $|a_2(Q_i)|\geq\alpha$, where $a_{2}(Q_i)$ denotes the second coefficient of the Conway polynomial of $Q_i$.

Application Of A Square‐Wave Potential Program For Time‐Dependent Amperometric Detection In Capillary Electrophoresis, Stephanie Hooper, David Roach, Mark Anderson

Mark R. Anderson

Use of a square-wave potential program for time-dependent amperometric detection of analyte zones in capillary electrophoresis (CE) is described. Electrochemical detection for CE requires that the separation field be isolated from that of the electrochemical detection. This is generally done by physically separating the CE separation field from that of the detection. By applying a time variant potential program to the detection electrode, the detector current has a time dependence that can be used to help isolate the electrochemical detection current from that of the separation. When using a 20 μm inner-diameter capillary, we find that a square-wave potential program …

Nonlocal Validity Of An Asymptotic One-Dimensional Nematicon Solution, Tim Marchant

Tim Marchant

The propagation of coherent, polarized light in a nematic liquid crystal, governed by the nematicon equations, is considered. It is found that in the special case of 1 + 1 dimensions and the highly nonlocal limit, the nematicon equations have an asymptotic bulk solitary wave solution, termed a nematicon, which is given in terms of Bessel functions. This asymptotic solution gives both the ground state and the symmetric and antisymmetric excited states, which have multiple peaks. Numerical simulations of nematicon evolution, for parameters corresponding to experimental scenarios, are presented. It is found, for experimentally reasonable parameter choices, that the validity …

Nearly Tight Bounds On The Encoding Length Of The Burrows-Wheeler Transform., Roberto Grossi, Ankur Gupta, Jeffery Vitter

Ankur Gupta

Rounds, Levels, And Waves: The Early Evolution Of Gameplay Segmentation, Jose Zagal, Clara Fernandez-Vara, Michael Mateas

Jose P Zagal

This article explores the early evolution of the structure and management of gameplay in videogames. We introduce the notion of gameplay segmentation to capture the role that design elements like level, boss, and wave play in videogames, and identify three modes of segmentation. Temporal segmentation limits, synchronizes and/or coordinates player activity over time. Spatial segmentation breaks the game’s virtual space into sub-locations. Challenge segmentation presents the player with a sequence of self-contained challenges. We describe each mode, and additional sub-modes, by analyzing vintage arcade games. Our analyses illustrate how these games represent a “primordial soup” in which many current game …

Protease Activation Of A2-Macroglobulin Modulates A Chaperone-Like Action With Broad Specificity, Katie French, Justin Yerbury, Mark Wilson

Mark R Wilson

α2-Macroglobulin (α2M) is a major human blood glycoprotein best known for its ability to inhibit a broad spectrum of proteases by a unique trapping method. This action induces an “activated” conformation of α2M with an exposed binding site for the low density lipoprotein receptor, facilitating clearance of α2M-protease complexes from the body. This report establishes that protease activation also modulates a potent chaperone-like action of α2M which has broad specificity for proteins partly unfolded as a result of heat or oxidative stress. Protease-mediated activation of α2M abolishes its chaperone-like activity. However, native α2M is able to form soluble complexes with …

Dipole Soliton Formation In A Nematic Liquid Crystal In The Non-Local Limit, Tim Marchant

Tim Marchant

The interaction of two symmetric solitary waves, termed nematicons, in a liquid crystal is considered in the limit of nonlocal response of the liquid crystal. This nonlocal limit is the applicable limit for most experimentally available liquid crystals. In this nonlocal limit, two separate cases for the initial separation of the nematicons are considered, these being large and small separation. Both spinning and nonspinning nematicons are considered. It is found that in the case of large initial separation, the nematicons can form a spinning or nonspinning bound state with a finite steady separation, this being called a nematicon dipole, when …

Association-Based Image Retrieval, Arun D. Kulkarni, H. Gunturu, S. Datla

Arun Kulkarni

No abstract provided.

Association-Based Image Retrieval, Arun D. Kulkarni, Harikrisha Gunturu, Srikanth Datla

Arun Kulkarni

Characterization And Properties Of Matrices With K-Involutory Symmetries, William F. Trench

William F. Trench

No abstract provided.

Deformation Associated With A Continental Normal Fault System, Western Grand Canyon, Arizona, Phillip G. Resor

Phillip G Resor

Reverse-drag folds are often used to infer subsurface fault geometry in extended terrains, yet details of how these folds form in association with slip on normal fault systems are poorly understood. Detailed structural mapping and global positioning system (GPS) surveying of the Frog Fault and Lone Mountain Monocline in the western Grand Canyon demonstrate a systematic relationship between elements of the normal fault system and fold geometry. The Lone Mountain Monocline, which parallels the Frog Fault, is made up of two half-monoclinal flexures: a hanging-wall fold in which dips gradually increase toward the fault over ~1.5 km reaching a maximum …