Physical Sciences and Mathematics Commons^™

Simultaneous Determination Of Pramoxine Hcl And Benzalkonium Chloride In Wound Care Solutions By Hplc, Panagiotis Tavlarakis, Jonine Greyling, Nicholas Snow

Nicholas A Snow

No abstract provided.

Complementary Spectroscopic Assays For Investigating Protein−Ligand Binding Activity: A Project For The Advanced Chemistry Laboratory, David Mascotti, Mark Waner

Mark J. Waner

A protein−ligand binding, guided-inquiry laboratory project with potential application across the advanced undergraduate curriculum is described. At the heart of the project are fluorescence and spectrophotometric assays utilizing biotin-4-fluorescein and streptavidin. The use of the same stock solutions for an assay that may be examined by two distinct spectroscopic techniques offers an opportunity to discuss not only protein−ligand binding but also to compare instrumental techniques and to discuss the underlying physical principles that are the origins of the assays. In addition to critically evaluating analytical techniques, students are pushed to develop quantitative pipetting, estimation, and experimental-design skills to collect and …

Partially Materialized Digest Scheme: An Efficient Verification Method For Outsourced Databases, Kyriakos Mouratidis, Dimitris Sacharidis, Hwee Hwa Pang

Kyriakos MOURATIDIS

In the outsourced database model, a data owner publishes her database through a third-party server; i.e., the server hosts the data and answers user queries on behalf of the owner. Since the server may not be trusted, or may be compromised, users need a means to verify that answers received are both authentic and complete, i.e., that the returned data have not been tampered with, and that no qualifying results have been omitted. We propose a result verification approach for one-dimensional queries, called Partially Materialized Digest scheme (PMD), that applies to both static and dynamic databases. PMD uses separate indexes …

Associative Search Network: A Reinforcement Learning Associative Memory, Andrew Barto, Richard Sutton, Peter Brouwer

Andrew G. Barto

An associative memory system is presented which does not require a "teacher" to provide the desired associations. For each input key it conducts a search for the output pattern which optimizes an external payoff or reinforcement signal. The associative search network (ASN) combines pattern recognition and function optimization capabilities in a simple and effective way. We define the associative search problem, discuss conditions under which the associative search network is capable of solving it, and present results from computer simulations. The synthesis of sensory-motor control surfaces is discussed as an example of the associative search problem.

Identifying Useful Subgoals In Reinforcement Learning By Local Graph Partitioning, Özgür Şimşek, Alicia Wolfe, Andrew Barto

Andrew G. Barto

We present a new subgoal-based method for automatically creating useful skills in reinforcement learning. Our method identifies subgoals by partitioning local state transition graphs—those that are constructed using only the most recent experiences of the agent. The local scope of our subgoal discovery method allows it to successfully identify the type of subgoals we seek—states that lie between two densely-connected regions of the state space—while producing an algorithm with low computational cost.

Linear Least-Squares Algorithms For Temporal Difference Learning, Steven Bradtke, Andrew Barto

Andrew G. Barto

We introduce two new temporal difference (TD) algorithms based on the theory of linear leastsquares function approximation. We define an algorithm we call Least-Squares TD (LS TD) for which we prove probability-one convergence when it is used with a function approximator linear in the adjustable parameters. We then define a recursive version of this algorithm, Recursive Least-Squares TD (RLS TD). Although these new TD algorithms require more computation per time-step than do Sutton's TD(A) algorithms, they are more efficient in a statistical sense because they extract more information from training experiences. We describe a simulation experiment showing the substantial improvement …

Air Shower Simulation Using Geant4 And Commodity Parallel Computing, L. Anchordoqui, G. Cooperman, V. Grinberg, T. Mccauley, T. Paul, S. Reucroft, J. Swain, G. Alverson

Gene D. Cooperman

We present an evaluation of a simulated cosmic ray shower, based on GEANT4 and TOP-C, which tracks all the particles in the shower. TOP-C (Task Oriented Parallel C) provides a framework for parallel algorithm development which makes tractable the problem of following each particle. This method is compared with a simulation program which employs the Hillas thinning algorithm.

Lego Rover Control, Gang-Ryung Uh

Gang-Ryung Uh

Book Review Of "Natural Climate Variability And Global Warming: A Holocene Perspective" Edited By Richard W. Battarbee And Heather A. Binney, Shaily Menon

Shaily Menon

No abstract provided.

Is Necessity The Mother Of Innovation? The Adoption And Use Of Web Technologies Among Congressional Offices, Kevin Esterling, David Lazer, Michael Neblo

David Lazer

From first paragraph: Communication between legislator and constituents is fundamental to effective democratic representation, and devising the institutional means for citizen/legislator communication stands as one of the core and persistent problems in the practice of democracy. A legislator needs information about the preferences, ideals, norms, and beliefs of her constituents in order to do her job well. Similarly, citizens need information about the actions and decisions of their representative in order to maintain appropriate accountability. But as national problems become more complex, and as the political process grows more and more dominated by experts and organized groups, it is becoming …

The Impact Of Quality Management Systems During A Pebble Bed Modular Reactor Project : A Case Study, Lwandiso Zamxaka

Lwandiso L Zamxaka

In the nuclear industry, Quality Management Systems are extremely important,especially if one wishes to improve public acceptance of radioactive solutions.There is normally minimum communication between the public and scientists,especially in nuclear science. People are not comfortable with nuclear technology,based on the past history of the Chernobyl catastrophe. Consequently, it is difficult to discuss important and sensitive issues like disposing of nuclear waste. Quality Management Systems can improve public confidence and communication. Integrated Management Systems in the project planning stage of the project can be a proactive step towards preventing unnecessary delays and costs. There is a perception that quality is …

Is Philosophy Dead? Far From It, Charles Weijer

Charles Weijer

No abstract provided.

Rotman Institute Opening, Joseph Rotman, Janice Deakin, Jane Maienschein, Charles Weijer, Philip Kitcher

Charles Weijer

No abstract provided.

Integrating Environmental Science And Management: The Role Of System Dynamics Modelling, Kristin Den Exter

Dr Kristin den Exter

Institutional and epistemological differences between science and management present a challenge to the implementation of sustainable environmental management. Environmental problems are complex and require at least multidisciplinary, but most effectively transdisciplinary approaches for learning, understanding, decision-making and problem solving. This means building bridges between institutional and epistemological differences. The role of system dynamics modelling in integrating environmental science and management is examined in this thesis. An action research methodology is adopted where, over cycles of case studies, the practical application of system dynamics modelling is evaluated. The role of system dynamics modelling in the management of coastal sand dunes, tourism, …

Assisting Stakeholder Decision Making Using System Dynamics Group Model-Building, Kristin Den Exter, Alison Specht

Dr Kristin den Exter

Stakeholder involvement in environmental management in Australia is increasingly participatory. A community-government partnership has been the central focus of the NSW program of water reforms since the inception of the Water Act 2000. Under the Act, it is the joint responsibility of the New South Wales Government and stakeholder-based Water Management Committees to develop Water Sharing Plans. Water Management Committees typically comprise government, environmental and agricultural representatives. This paper describes a System Dynamics group model-building workshop conducted with the Northern Rivers Water Management Committee. A role of the Committee was to determine the allocation of water between the water users …

The Protection Of Rights Management Information: Modernization Or Cup Half Full?, Mark Perry

Mark Perry

Many papers in this collection discuss the history and development of Bill C-32, An Act to Amend the Copyright Act, introduced into the Canadian Parliament on 2 June 2010, so that analysis will not be duplicated here. Among the failures of copyright reform has been the lack of addressing the required “balancing” of proprietary rights on the one hand, with user rights and the public domain on the other. Rights Management Information (RMI) can aid in this balancing. The RMI of a work is simply data that provide iden- tification of rights related to that work, either directly or indirectly. …

Characterizing Preservice Teachers’ Mathematical Understanding Of Algebraic Relationships, Leah A. Nillas

Leah A. Nillas

Remediation Of Coastal Acid Sulfate Soils By Tidal Inundation: Effectiveness And Geochemical Implications, Scott Johnston, Annabelle Keene, Richard Bush, Edward Burton, Leigh Sullivan

Associate Professor Edward D Burton

The effects of restoring marine tidal inundation to a severely degraded acid sulfate soil landscape were investigated. Five years of regular tidal inundation led to substantial improvements in a range of key parameters used to assess soil and water quality. The pH of estuarine creeks improved dramatically following reintroduction of tidal inundation. Time series water quality and climatic data indicate a substantial decrease in the magnitude of creek acidification per given quantity of antecedent rainfall. The soil pH also increased by 2–3 units and titratable actual acidity (TAA) decreased by ~40–50 μmol H+ g-1 within former sulfuric horizons. Tidal inundation …

A Web 2.0/Web3d Hybrid Platform For Engaging Students In E-Learning Environments, Penny De Byl, Janet Taylor

Penny de Byl

This paper explores the Web 2.0 ethos with respect to the application of pedagogy within 3D online virtual environments. 3D worlds can create a synthetic experience capturing the essence of being in a particular world or context. The AliveX3D platform adopts the Web 2.0 ethos and applies it to online 3D virtual environment forming a Web 2.0/Web3D hybrid that has wider usability than previous alternatives. This combined with the AliveX3D Scene Editor allows learning experiences, which are controlled by the learner, appear authentic and facilitate collaboration conversations to be developed simultaneously. This immersion enables learners to negotiate meaning based on …

Patterns In Rotating Rayleigh–Bénard Convection At High Rotation Rates, Janet Scheel, P. Mutyaba, T. Kimmel

Janet D. Scheel

We present the results from numerical and theoretical investigations of rotating Rayleigh–Bénard convection for relatively large dimensionless rotation rates, 170 < Ω < 274, and a Prandtl number of 6.4. Unexpected square patterns were found experimentally by Bajaj et al. (Phys. Rev. Lett., vol. 81, 1998, p. 806) in this parameter regime and near threshold for instability in the bulk. These square patterns have not yet been understood theoretically. Sánchez-Álvarez et al. (Phys. Rev. E, vol. 72, 2005, p. 036307) have found square patterns in numerical simulations for similar parameters when only the Coriolis force is included. We performed detailed numerical studies …

Frequency Dependence In The Initiation Of Laser-Induced Damage, Jeremy Gulley

Jeremy R. Gulley

Numerous studies have investigated the role of photoionization in ultrafast laser-induced damage of bulk dielectrics. This study examines the role of spectral width and instantaneous laser frequency in laser-induced damage using a frequency dependent multiphoton ionization model and numerical simulation of an 800 nm laser pulse propagating through fused silica. When the individual photon wavelengths are greater than 827 nm, an additional photon is required for photoionization, reducing the probability of the event by many orders of magnitude. Simulation results suggest that this frequency dependence may significantly affect the processes of laser-induced damage and filamentation.

Particulate Pictures And Kinetic-Molecular Theory Concepts: Seizing An Opportunity, Mark Waner

Mark J. Waner

This work examines commonly used particulate-level pictures meant to illustrate gases. These pictures are found throughout textbooks in the middle grades through the college level, as well as in questions frequently used to assess conceptual learning in students. This work uses the kinetic-molecular theory of gases to demonstrate the inaccuracies often present in these figures, which offers the opportunity to address model limitations to students and to develop better pictures. A basis for using these pictures to discuss models and ideas for ways these pictures can be used for inquiry activities based on analysis of scales is also discussed.

Kinetic And Mechanistic Studies Of The Deuterium Exchange In Classical Keto−Enol Tautomeric Equilibrium Reactions, Michael Nichols, Mark Waner

Mark J. Waner

An extension of the classic keto−enol tautomerization of β-dicarbonyl compounds into a kinetic analysis of deuterium exchange is presented. It is shown that acetylacetone and ethyl acetoacetate undergo nearly complete deuterium exchange of the α-methylene carbon when dissolved in methanol-d4. The extent of deuteration may be monitored via NMR spectroscopy as a function of time. A mechanism for deuterium exchange is presented and shown to be consistent with a consecutive first-order process. The data for acetylacetone are consistent with steady-state kinetics, whereas those of ethyl acetoacetate illustrate nonsteady-state behavior, offering an accessible example where students might collect and analyze real …

Fe And S K-Edge Xas Determination Of Iron-Sulfur Species Present In A Range Of Acid Sulfate Soils: Effects Of Particle Size And Concentration On Quantitative Xanes Determinations, Kate Morgan, Edward Burton, Perran Cook, Mark Raven, Robert Fitzpatrick, Richard Bush, Leigh Sullivan, Rosalie Hocking

Associate Professor Edward D Burton

Acid sulfate soils (ASS) are soils and soft sediments in which sulfuric acid may be produced from iron sulfides or have been produced leaving iron oxyhydroxysulfates in amounts that have a long lasting effect on soil characteristics. If soil material is exposed to rotting vegetation or other reducing material, the Fe-oxyhydroxysulfates can be bacterially reduced to sulfides including disulfides (pyrite and marcasite), and Monosulfidic Black Ooze (MBO) a poorly characterised material known to be a mixture of iron sulfides (especially mackinawite) and organic matter. The chemistry of these environments is strongly affected by Fe and S cycling processes and herein …

Use A Mobile Phone To Control Zigbee Enabled Harex Dynamic Natural Light Leds, Gang-Ryung Uh

Gang-Ryung Uh

Performance Analysis Of Real-Time Component Architectures: An Enhanced Model Interchange Approach, Gabriel Moreno, Connie Smith

Gabriel A. Moreno

Model interchange approaches support the analysis of software architecture and design by enabling a variety of tools to exchange performance models using a common schema. This paper builds on the Software Performance Model Interchange Format (S-PMIF), extending it to support the analysis of real-time systems and adapting it to be suitable for implementation with modeling frameworks such as MOF or EMF. This enhances the model interchange process by making it possible to define model-to-model transformations from design models into software performance models. The paper addresses real-time system designs expressed in CCL and their transformation into the S-PMIF for additional performance …

A Case History Of The Science And Management Collaboration In Understanding Hypoxia Events In Long Bay, South Carolina, Usa., Denise Sanger, Debra Hernandez, Susan Libes, George Voulgaris, Braxton Davis, Erik Smith, Rebecca Shufford, Dwayne Porter, Eric Koepfler, Joseph Bennet

George Voulgaris

Communication of knowledge between the scientific and management communities is a difficult process complicated by the distinctive nature of professional career goals of scientists and decision-makers. This article provides a case history highlighting a collaboration between the science and management communities that resulted from a response to a 2004 hypoxia, or low dissolved oxygen, event in Long Bay, off Myrtle Beach, South Carolina. A working group of scientists and decision-makers was established at the time of the event and has continued to interact to develop a firm understanding of the drivers responsible for hypoxia formation in Long Bay. Several factors …

Evolution Of The Kangmar Dome, Southern Tibet: Structural, Petrologic, And Thermochronologic Constraints, Jeffrey Lee, Bradley Hacker, William Dinklage, Yu Wang, Phillip Gans, Andrew Calvert, Ann Blythe, William Mcclelland

Ann Blythe

Structural, thermobarometric, and thermochronologic investigations of the Kangmar Dome, southern Tibet, suggest that both extensional and contractional deformational histories are preserved within the dome. The dome is cored by an orthogneiss which is mantled by staurolite + kyanite zone metasedimentary rocks; metamorphic grade dies out up section and is defined by a series of concentric kyanite-in, staurolite-in, garnet-in, and chloritoid-in isograds. Three major deformational events, two older penetrative events and a younger doming event, are preserved. The oldest event, D1, resulted in approximately E-W trending tight to isoclinal folds of bedding with an associated moderately to steeply north dipping axial …

Thanks To 2d And Maybe Even Beyond: 115 Gev And 140 Gev Almost Standard Model Higgs Without Problems, Marko Popovic

Marko B. Popovic

I address four key points: (1) dynamical, likely local Higgs mass generation (potentially in 2D) as resolution to the 4D hierarchy and vacuum energy problems, (2) possibility that top condensation may be explained by an interplay among the gluon and scalar sectors, (3) the Higgs Mass Zero Crossing (HMZC) scale, most likely equal to the electro-weak symmetry breaking scale, 􀢫􀡱􀢃􀡿􀡮 , in accord with standard cosmology or classic inflation, and (4) two preferred Higgs regions centered at 􀫚􀫚􀫟. 􀫞 􀡳􀢋􀢂and 􀫚􀫝􀫙. 􀫞 􀡳􀢋􀢂 with related high energy models. I show that the Standard Model (SM) in 2D could simultaneously satisfy …

Body Mass Index, Treatment Practices, And Mortality In Patients With Acute Heart Failure, Timothy Fitzgibbons, Olga Hardy, Darleen Lessard, Joel Gore, Jorge Yarzebski, Robert Goldberg

Jorge L. Yarzebski

OBJECTIVES: Obesity is associated with an increased risk of heart failure (HF). Among patients presenting with acute HF, however, differences in clinical characteristics, treatment regimens, and short-term prognosis of varying weights are largely unknown, particularly from a broader population-based perspective. METHODS: A total of 3722 patients admitted with acute HF to 11 greater Worcester (Massachusetts, USA) hospitals during 1995 and 2000 were categorized as being lean (n = 216), normal weight (n = 1465), overweight (n = 1007), or obese (n = 1034) at the time of hospitalization. RESULTS: Obese patients with decompensated HF were significantly younger (mean age = …