Physical Sciences and Mathematics Commons^™

Ssrn As An Initial Revolution In Academic Knowledge Aggregation And Dissemination, David Bray, Sascha Vitzthum, Benn Konsynski

Sascha Vitzthum

Within this paper we consider our results of using the Social Science Research Network (SSRN) over a period of 18 months to distribute our working papers to the research community. Our experiences have been quite positive, with SSRN serving as a platform both to inform our colleagues about our research as well as inform us about related research (through email and telephoned conversations of colleagues who discovered our paper on SSRN). We then discuss potential future directions for SSRN to consider, and how SSRN might well represent an initial revolution in 21st century academic knowledge aggregation and dissemination. Our paper …

Sub-Micron Parallel Laser Direct-Write, Christina Othon, Arnoldo Laracuente, H Ladoucuer, Bradley Ringeisen

Christina M Othon

We have developed a modified laser induced forward transfer (LIFT) technique which allows for the parallel deposition of hundreds of sub-micron features. The approach utilizes a self-assembled monolayer of monodisperse polystyrene microspheres as the focusing element. A monolayer of close-packed microspheres is formed on top of an ultra-thin quartz support (25 m thick), and a metallic thin film is then deposited on the underside of the quartz. This approach is different from previous parallel microsphere-assisted LIFT experiments that required the deposition of metal directly onto the surface of the periodic microsphere structure. For this study, an 800 nm, 130 fs …

An Aztec 1.1 Mm Survey Of The Goods-N Field – I. Maps, Catalogue And Source Statistics, Thushara Perera, E. Chapin, J. Austermann, K. Scott, G. Wilson, M. Halern, A. Pope, D. Scott, M. Yun, J. Lowenthal, G. Morrison, I. Aretxaga, J. Bock, K. Coppin, M. Crowe, L. Frey, D. Hughes, Y. Kang, S. Kim, P. Mauskopf

Thushara A. Perera

No abstract provided.

Towards Self-Organizing, Smart Business Networks: Let’S Create ‘Life’ From Inert Information, David Bray, Benn Konsynski

David A. Bray

We review three different theories that can inform how researchers can determine the performance of smart business networks, to include: (1) the Theory of Evolution, (2) the Knowledge-Based Theory of the Firm, and (3) research insights into computers and cognition. We suggest that each of these theories demonstrate that to be generally perceived as smart, an organism needs to be self-organizing, communicative, and tool-making. Consequentially, to determine the performance of a smart business network, we suggest that researchers need to determine the degree to which it is self-organizing, communicative, and tool-making. We then relate these findings to the Internet and …

Adhesion And Interfacial Fracture Toughness Between Hard And Soft Materials, Nima Rahbar, Kurt Wolf, Argjenta Orana, Roy Fennimore, Zong Zong, Juan Meng, George Papandreou, Cynthia Maryanoff, Wole Soboyejo

Nima Rahbar

This paper presents the results of a combined experimental and theoretical study of adhesion between hard and soft layers that are relevant to medical devices such as drug-eluting stents and semiconductor applications. Brazil disk specimens were used to measure the interfacial fracture energies between model parylene C and 316L stainless steel over a wide range of mode mixities. The trends in the overall fracture energies are predicted using a combination of adhesion theories and fracture mechanics concepts. The measured interfacial fracture energies are shown to be in good agreement with the predictions.

Potential Driven Deposition Of Poly(Diallyldimethylammonium Chloride) Onto The Surface Of 3-Mercaptopropionic Acid Monolayers Assembled On Gold, Wesley Sanders, Mark Anderson

Mark R. Anderson

Electrochemical impedance spectroscopy (EIS) and quartz crystal microbalance (QCM) measurements are used to examine the ability of applied potential to drive the ionic self-assembly of poly(diallyldimethylammonium) chloride (PDDA) onto a substrate modified with a monolayer of 3-mercaptopropionic acid (3-MPA). The potential of zero charge (PZC) of the gold electrode modified with a monolayer of 3-MPA was found by differential capacitance measurements to be −0.12 (±0.01) V versus Ag−AgCl. Changing the substrate potential to values positive (−0.01 V vs Ag−AgCl) of the PZC induces interfacial conditions that are favorable for the electrostatic deposition of cationic polymers onto the surface of 3-MPA …

The Role Of Science And Engineering In Water Regulation Over The Past 100 Years, James R. May, Patrick Clary

James R. May

This article explores how scientific and engineering principles are inexorably linked to the regulation of water. Scientists and engineers first discovered the link between disease and water sources in the mid-19th century. Over the years, scientists and engineers have led the way to identifying water quality problems and their causes. These discoveries have directly contributed to the scope of water regulation in the United States and elsewhere. In addition, changes in water quality regulation have dictated the need for increasingly sophisticated water treatment technologies and engineers have been at the forefront of the development of these water control technologies. This …

Sequence Specific And High Affinity Recognition Of 5′-Acgcgt-3′ By Rationally Designed Pyrrole-Imidazole H-Pin Polyamides: Thermodynamic And Structural Studies., Hilary Mackay, Toni Brown, Peter Uthe, Laura Westrate, Alan Sielaff, Justin Jones, James Lajiness, Jerome Kluza, Caroline O'Hare, Binh Nguyen, Zach Davis, Chrystal Bruce, W. Wilson, John Hartley, Moses Lee

Chrystal D. Bruce

Imidazole (Im) and Pyrrole (Py)-containing polyamides that can form stacked dimers can be programmed to target specific sequences in the minor groove of DNA and control gene expression. Even though various designs of polyamides have been thoroughly investigated for DNA sequence recognition, the use of H-pin polyamides (covalently cross-linked polyamides) has not received as much attention. Therefore, experiments were designed to systematically investigate the DNA recognition properties of two symmetrical H-pin polyamides composed of PyImPyIm (5) or f-ImPyIm (3e, f=formamido) tethered with an ethylene glycol linker. These compounds were created to recognize the cognate 5′-ACGCGT-3′ through an overlapped and staggered …

Spatio-Temporal Efficiency In A Taxi Dispatch System, Darshan Santani, Rajesh Krishna Balan, C. Jason Woodard

C. Jason Woodard

In this paper, we present an empirical analysis of the GPS-enabled taxi dispatch system used by the world’s second largest land transportation company. We first summarize the collective dynamics of the more than 6,000 taxicabs in this fleet. Next, we propose a simple method for evaluating the efficiency of the system over a given period of time and geographic zone. Our method yields valuable insights into system performance—in particular, revealing significant inefficiencies that should command the attention of the fleet operator. For example, despite the state of the art dispatching system employed by the company, we find imbalances in supply …

Intersecting Families And Definability, Andrés Caicedo

Andrés E. Caicedo

No abstract provided.

Significant Figures, Tony Badrick, Peter Hickman

Tony Badrick

For consistency of reporting the same number of significant figures should be used for results and reference intervals. The choice of the reporting interval should be based on analytical imprecision (measurement uncertainty).

A Symbolic Operator Approach To Power Series Transformation-Expansion Formulas, Tian-Xiao He

Tian-Xiao He

In this paper we discuss a kind of symbolic operator method by making use of the defined Sheffer-type polynomial sequences and their generalizations, which can be used to construct many power series transformation and expansion formulas. The convergence of the expansions are also discussed.

The Study Of Optogalvanic Effect Associated With The 1s States Of Neon, Naveed Piracha, K. Nesbett, S. Marotta

Naveed K. Piracha

We report on the temporal evolution of the optogalvanic signals in neon using a commercial hollow cathode lamp in conjunction with a Nd:YAG pumped dye laser system. We have recorded transitions excited from each of the neon 1s states over a range of discharge current to investigate the dominant physical processes responsible for the optogalvanic effect in neon discharges. The decay rates associated with the four 1s levels have been obtained using a mathematical rate equation model. A linear relationship between the decay rates and the discharge current has been found and the effective lifetimes and the electron collisional rate …

Characterization Of Carboxylic Acid-Terminated Self-Assembled Monolayers By Electrochemical Impedance Spectroscopy And Scanning Electrochemical Microscopy, Wesley Sanders, Ricardo Vargas, Mark Anderson

Mark R. Anderson

Electrochemical impedance spectroscopy (EIS) and scanning electrochemical microscopy (SECM) are used to monitor changes in the ionization of monolayers of 11-mercaptoundecanoic acid. When using an anionic redox probe, Fe(CN)6−4, the charge-transfer resistance of the 11-mercaptoundecanoic acid monolayer-modified interface increases in a sigmoidal fashion as the solution is made basic. The opposite effect is observed when using a cationic redox probe. The inflection points of these two titration curves, however, differ when using the different redox probes. This result is taken as being characteristic of the influence that applied potential has on the ionization of the monolayer. The role of substrate …

Locally Adaptive Nonparametric Binary Regression, Sally Wood, Martin Tanner, Wenxin Jiang, Robert Kohn, Remy Cottet

Sally Wood

No abstract provided.

A Self-Organizing Map For Adaptive Processing Of Structured Data, Markus Hagenbuchner, A. Sperduti, Ah Chung Tsoi

Ah Chung Tsoi

Recent developments in the area of neural networks produced models capable of dealing with structured data. Here, we propose the first fully unsupervised model, namely an extension of traditional self-organizing maps (SOMs), for the processing of labeled directed acyclic graphs (DAGs). The extension is obtained by using the unfolding procedure adopted in recurrent and recursive neural networks, with the replicated neurons in the unfolded network comprising of a full SOM. This approach enables the discovery of similarities among objects including vectors consisting of numerical data. The capabilities of the model are analyzed in detail by utilizing a relatively large data …

Simulation And Analysis Of Ultrafast-Laser-Pulse-Induced Plasma Generation In Fused Silica, Jeremy Gulley, Sebastian Winkler, W. M. Dennis

Jeremy R. Gulley

Recent experiments on optical damage by ultrashort laser pulses have demonstrated that the temporal pulse shape can dramatically influence plasma generation in fused silica. We use a modified 3+1D nonlinear Schrödinger equation for the pulse propagation coupled to a rate equation for the plasma density in the dielectric material to simulate pulse propagation and plasma formation in fused silica. We use these simulations to analyze the influence of pulse shape and beam geometry on the formation of the electron plasma and hence modification in the bulk material. In particular, we simulate the effect of pulses reconstructed from experimental data. It …

Modifying The N-Terminus Of Polyamides: Pyimpyim Has Improved Sequence Specificity Over F-Impyim, Toni Brown, Hilary Mackay, Mark Turlington, Arden Sutterfield, Traci Smith, Alan Sielaff, Laura Westrate, Chrystal Bruce, Jerome Kluza, Caroline O'Hare, Binh Nguyen, W. Wilson, John Hartley, Moses Lee

Chrystal D. Bruce

Seven N-terminus modified derivatives of a previously published minor-groove binding polyamide (f-ImPyIm, 1) were synthesized and the biochemical and biophysical chemistry evaluated. These compounds were synthesized with the aim of attaining a higher level of sequence selectivity over f-ImPyIm (1), a previously published strong minor-groove binder. Two compounds possessing a furan or a benzofuran moiety at the N-terminus showed a footprint of 0.5μM at the cognate ACGCGT site (determined by DNase I footprinting); however, the specificity of these compounds was not improved. In contrast, PyImPyIm (4) produced a footprint of 0.5μM but showed a superior specificity using the same technique. …

Simultaneous Determination Of Glucose And L‐Glutamate Using A Capillary Enzyme Reactor With Electrochemical Detection, Stephanie Hooper, Mark Anderson

Mark R. Anderson

An electrophoresis capillary that incorporates two enzymes for the simultaneous determination of glucose and l-glutamate is described. The enzymes deposited along the separation capillary walls react with their respective substrate as they are separated during the electrophoresis to produce hydrogen peroxide that is detected by amperometry as the hydrogen peroxide zone emerges from the end of the capillary. Even though both enzyme reactions produce a common product, hydrogen peroxide, the hydrogen peroxide produced by each enzyme reaction stays in narrow zones that migrate the length of the capillary at different rates. The rate of migration for the individual H2O2 zones …

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. …

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.