Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

2010

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 4681 - 4710 of 8620

Full-Text Articles in Physical Sciences and Mathematics

Nmr Dynamics Investigation Of Ligand-Induced Changes Of Main And Side-Chain Arginine N-H’S In Human Phosphomevalonate Kinase, Andrew L. Olson, Sheng Cai, Timothy J. Herdendorf, Henry M. Miziorko, Daniel S. Sem Feb 2010

Nmr Dynamics Investigation Of Ligand-Induced Changes Of Main And Side-Chain Arginine N-H’S In Human Phosphomevalonate Kinase, Andrew L. Olson, Sheng Cai, Timothy J. Herdendorf, Henry M. Miziorko, Daniel S. Sem

Chemistry Faculty Research and Publications

Phosphomevalonate kinase (PMK) catalyzes phosphoryl transfer from adenosine triphosphate (ATP) to mevalonate 5-phosphate (M5P) on the pathway for synthesizing cholesterol and other isoprenoids. To permit this reaction, its substrates must be brought proximal, which would result in a significant and repulsive buildup of negative charge. To facilitate this difficult task, PMK contains 17 arginines and eight lysines. However, the way in which this charge neutralization and binding is achieved, from a structural and dynamics perspective, is not known. More broadly, the role of arginine side-chain dynamics in binding of charged substrates has not been experimentally defined for any protein to …


On The Anomalous Balmer Line Strengths In Globular Clusters, Violet Poole, Guy Worthey, Hyun Chul Lee, Jedidiah Serven Feb 2010

On The Anomalous Balmer Line Strengths In Globular Clusters, Violet Poole, Guy Worthey, Hyun Chul Lee, Jedidiah Serven

Physics and Astronomy Faculty Publications and Presentations

Spectral feature index diagrams with integrated globular clusters and simple stellar population models often show that some clusters have weak Hβ, so weak that even the oldest models cannot match the observed feature depths. In this work, we rule out the possibility that abundance mixture effects are responsible for the weak indices unless such changes operate to cool the entire isochrone. We discuss this result in the context of other explanations, including horizontal branch morphology, blue straggler populations, and nebular or stellar emission fill-in, finding a preference for flaring in M giants as an explanation for the Hβ anomaly. © …


Remarkable Iodine-Catalyzed Synthesis Of Novel Pyrrole- Bearing N-Polyaromatic B-Lactams, Debasish Bandyopadhyay, Gildardo Rivera, Isabel Salinas, Hector Aguilar, Bimal K. Banik Feb 2010

Remarkable Iodine-Catalyzed Synthesis Of Novel Pyrrole- Bearing N-Polyaromatic B-Lactams, Debasish Bandyopadhyay, Gildardo Rivera, Isabel Salinas, Hector Aguilar, Bimal K. Banik

Chemistry Faculty Publications and Presentations

Because of their interesting biological properties various methods for the synthesis of substituted pyrroles are described in the literature. However, synthesis of pyrroles fused with a β-lactam ring has not been reported. Our group has demonstrated synthesis and biological evaluation of various β-lactams as anticancer agents. The anticancer activities of these compounds have prompted us to study the synthesis of pyrroles bound to the β-lactams. We have identified an expeditious synthetic method for the preparation of pyrroles fused with β-lactams by reacting 3-amino β-lactams with acetonylacetone in the presence of catalytic amounts (5 mol%) of molecular iodine at room temperature. …


Empirical Probability Distribution Of Journal Impact Factor And Over-The-Samples Stability In Its Estimated Parameters, Sudhanshu K. Mishra Feb 2010

Empirical Probability Distribution Of Journal Impact Factor And Over-The-Samples Stability In Its Estimated Parameters, Sudhanshu K. Mishra

Sudhanshu K Mishra

The data on JIFs provided by Thomson Scientific can only be considered as a sample since they do not cover the entire universe of those documents that cite an intellectual output (paper, article, etc) or are cited by others. Then, questions arise if the empirical distribution (best fit to the JIF data for any particular year) really represents the true or universal distribution, are its estimated parameters stable over the samples and do they have some scientific interpretation? It may be noted that if the estimated parameters do not exhibit stability over the samples (while the sample size is large …


Design And Implementation Of A Podcast Recording Studio For Business Communications, Timothy W. Mclaughlin Feb 2010

Design And Implementation Of A Podcast Recording Studio For Business Communications, Timothy W. Mclaughlin

Regis University Student Publications (comprehensive collection)

Podcasting is the creation of recorded information and its delivery over the Internet, using web syndication technology. Businesses around the world are increasing their use of podcasts as a means for delivering information to their customers and employees. The purpose of this project paper is to examine the business need for podcasting, and to demonstrate that businesses can assemble an inexpensive recording studio to create podcasts. The review of previous literature included an examination of why podcasting has become important to business communications; how some businesses are currently using podcasting as a communications tool; the technology involved in podcasting; and …


Battle For The Arctic/The Tipping Point, Thomas A. Ipri Feb 2010

Battle For The Arctic/The Tipping Point, Thomas A. Ipri

Library Faculty Publications

Although The Tipping Point: Global Warming at the Arctic Circle and The Battle for the Arctic come from different filmmakers and different distributors, they work well together as companion films. Both films are under 50 minutes each, making them a good fit for many classroom settings.


Estimating The Proportion Of Equivalently Expressed Genes In Microarray Data Based On Transformed Test Statistics, Shuo Jiao, Shunpu Zhang Feb 2010

Estimating The Proportion Of Equivalently Expressed Genes In Microarray Data Based On Transformed Test Statistics, Shuo Jiao, Shunpu Zhang

Shuo Jiao

In microarray data analysis, false discovery rate (FDR) is now widely accepted as the control criterion to account for multiple hypothesis testing. The proportion of equivalently expressed genes (π0) is a key component to be estimated in the estimation of FDR. Some commonly used π0 estimators (BUM, SPLOSH, QVALUE, and LBE ) are all based on p-values, and they are essentially upper bounds of π0. The simulations we carried out show that these four methods significantly overestimate the true π0 when differentially expressed genes and equivalently expressed genes are not well separated. To solve this problem, we first introduce a …


Develop Best Practices For Designing Internal Business Database-Driven Web Applications, Stephen C. Rash Feb 2010

Develop Best Practices For Designing Internal Business Database-Driven Web Applications, Stephen C. Rash

Regis University Student Publications (comprehensive collection)

When developing using newer technology, it is important for smaller information technology organizations to have universally accepted set of best practices to be able to successfully complete that type of endeavor. How can these universally accepted set of best practices be developed? Conducting research on accepted best practices can build the basis for your theories and assumptions. Next, in the context of your applications, develop an example application in the newer technology to test your theories and assumptions. Build the application like a construction project, the initial design is the blueprint, the database is the foundation and the user interface …


Sdss J1254+0846: A Binary Quasar Caught In The Act Of Merging, Paul J. Green, Adam D. Myers, Wayne A. Barkhouse, John S. Mulchaey, Vardha N. Bennert, Thomas J. Cox, Thomas L. Aldcroft Feb 2010

Sdss J1254+0846: A Binary Quasar Caught In The Act Of Merging, Paul J. Green, Adam D. Myers, Wayne A. Barkhouse, John S. Mulchaey, Vardha N. Bennert, Thomas J. Cox, Thomas L. Aldcroft

Physics

We present the first luminous, spatially resolved binary quasar that clearly inhabits an ongoing galaxy merger. SDSS J125455.09+084653.9 and SDSS J125454.87+084652.1 (SDSS J1254+0846 hereafter) are two luminous z = 0.44 radio-quiet quasars, with a radial velocity difference of just 215 km s–1, separated on the sky by 21 kpc in a disturbed host galaxy merger showing obvious tidal tails. The pair was targeted as part of a complete sample of binary quasar candidates with small transverse separations drawn from SDSS DR6 photometry. We present follow-up optical imaging which shows broad, symmetrical tidal arm features spanning some 75 kpc …


Interview With Darrell Sanders, Cully Community Garden, 2010 (Audio), Darrell Sanders Feb 2010

Interview With Darrell Sanders, Cully Community Garden, 2010 (Audio), Darrell Sanders

All Sustainability History Project Oral Histories

Interview of Darrell Sanders by Jeremy Cohen in Portland, Oregon on February 20th, 2010.

The interview index is available for download.


Core Gas Sloshing In Abell 1644, Ryan E. Johnson, Maxim Markevitch, Gary A. Wegner, Christine Jones, William R. Forman Feb 2010

Core Gas Sloshing In Abell 1644, Ryan E. Johnson, Maxim Markevitch, Gary A. Wegner, Christine Jones, William R. Forman

Dartmouth Scholarship

We present an analysis of a 72 ks Chandra observation of the double cluster Abell 1644 (z = 0.047). The X-ray temperatures indicate that the masses are M 500 = (2.6 ± 0.4) × 1014 h –1 M for the northern sub-cluster and M 500 = (3.1 ± 0.4) × 1014 h –1 M for the southern, main cluster. We identify a sharp edge in the radial X-ray surface brightness of the main cluster, which we find to be a cold front, with a jump in temperature of a factor of ~3. This edge possesses …


Nonequilibrium Statistical Mechanics Of Self-Propelled Hard Rods, Aparna Baskaran, M. Cristina Marchetti Feb 2010

Nonequilibrium Statistical Mechanics Of Self-Propelled Hard Rods, Aparna Baskaran, M. Cristina Marchetti

Physics - All Scholarship

Using tools of nonequilibirum mechanics, we study a model of self-propelled hard rods on a substrate in two dimensions to quantify the interplay of self-propulsion and excluded-volume effects. We derive of a Smoluchowski equation for the configurational probability density of self-propelled rods that contains several modifications as compared to the familiar Smoluchowski equation for thermal rods. As a side-product of out work, we also present a purely dynamical derivation of the Onsager form of the mean field excluded volume interaction among thermal hard rods.


Participatory Action Research In Learning Commons Design Planning, Margaret Brown-Sica, Karen Sobel, Erika Rogers Feb 2010

Participatory Action Research In Learning Commons Design Planning, Margaret Brown-Sica, Karen Sobel, Erika Rogers

Computer Science and Software Engineering

Purpose – The purpose of this paper is to document the process the Auraria Library went through to plan research methods to produce information for their learning commons project.

Design/methodology/approach – The paper provides an overview and the results of one library’s planning methods using user-centered and participatory action research (PAR) principles. It includes a literature review and data gathered from several information gathering sessions. It also discusses useful resources and ideologies found outside the field of library science, such as “placemaking” and the concept of “third place.”

Findings – Adopting values that honor user-centered, evidence-based decision making is a …


Targeting The Optimal Design In Randomized Clinical Trials With Binary Outcomes And No Covariate, Antoine Chambaz, Mark J. Van Der Laan Feb 2010

Targeting The Optimal Design In Randomized Clinical Trials With Binary Outcomes And No Covariate, Antoine Chambaz, Mark J. Van Der Laan

U.C. Berkeley Division of Biostatistics Working Paper Series

This article is devoted to the asymptotic study of adaptive group sequential designs in the case of randomized clinical trials with binary treatment, binary outcome and no covariate. By adaptive design, we mean in this setting a clinical trial design that allows the investigator to dynamically modify its course through data-driven adjustment of the randomization probability based on data accrued so far, without negatively impacting on the statistical integrity of the trial. By adaptive group sequential design, we refer to the fact that group sequential testing methods can be equally well applied on top of adaptive designs. Prior to collection …


Targeted Maximum Likelihood Based Causal Inference, Mark J. Van Der Laan Feb 2010

Targeted Maximum Likelihood Based Causal Inference, Mark J. Van Der Laan

U.C. Berkeley Division of Biostatistics Working Paper Series

Given causal graph assumptions, intervention-specific counterfactual distributions of the data can be defined by the so called G-computation formula, which is obtained by carrying out these interventions on the likelihood of the data factorized according to the causal graph. The obtained G-computation formula represents the counterfactual distribution the data would have had if this intervention would have been enforced on the system generating the data. A causal effect of interest can now be defined as some difference between these counterfactual distributions indexed by different interventions. For example, the interventions can represent static treatment regimens or individualized treatment rules that assign …


Infrared Spectroscopy Of Symbiotic Stars. Viii. Orbits For Three S-Type Systems: Ae Arae, Y Coronae Australis, And Ss 73-147, Francis C. Fekel, Kenneth H. Hinkle, Richard R. Joyce, Peter R. Wood Feb 2010

Infrared Spectroscopy Of Symbiotic Stars. Viii. Orbits For Three S-Type Systems: Ae Arae, Y Coronae Australis, And Ss 73-147, Francis C. Fekel, Kenneth H. Hinkle, Richard R. Joyce, Peter R. Wood

Information Systems and Engineering Management Research Publications

With new infrared radial velocities we have computed orbits of the M giants in three southern S-type symbiotic systems. AE Ara and SS 73-147 have circular orbits with periods of 803 and 820 days, respectively. The eccentric orbit of Y CrA has a period that is about twice as long, 1619 days. Except for CH Cyg it is currently the S-type symbiotic system with the longest period for which a spectroscopic orbit has been determined. The Paschen δ emission line velocities of AE Ara are nearly in antiphase with the M giant absorption feature velocities and result in a mass …


Agenda: Us-Mexico Negotiations On Improved Colorado River Management: An Update, University Of Colorado Boulder. Natural Resources Law Center, Western Water Policy Program, Colorado Water Conservation Board Feb 2010

Agenda: Us-Mexico Negotiations On Improved Colorado River Management: An Update, University Of Colorado Boulder. Natural Resources Law Center, Western Water Policy Program, Colorado Water Conservation Board

US-Mexico Negotiations on Improved Colorado River Management: An Update (February 19)

The United States and Mexico are currently negotiating an international accord on a variety of Colorado River water matters, including the prospects for new water projects, conservation efforts, and operational improvements. Participants are invited to hear an update on these efforts from individuals directly involved in the negotiations, including Mario López Pérez, Engineering and Technical Standards Manager in the National Water Commission of México, who is responsible for binational water issues with the USA, Guatemala and Belize.


Colorado River Water: Mexico's Perspective On The Ongoing Negotiations, Mario López Pérez Feb 2010

Colorado River Water: Mexico's Perspective On The Ongoing Negotiations, Mario López Pérez

US-Mexico Negotiations on Improved Colorado River Management: An Update (February 19)

Presenter: Mario López, Engineering and Technical Standards Manager, National Water Commission of México

53 slides


Selective Recursive Kernel Learning For Online Identification Of Nonlinear Systems With Narx Form, Yi Liu, Haiqing Wang, Jiang Yu, Ping Li Feb 2010

Selective Recursive Kernel Learning For Online Identification Of Nonlinear Systems With Narx Form, Yi Liu, Haiqing Wang, Jiang Yu, Ping Li

Dr. Yi Liu

Online identification of nonlinear systems is still an important while difficult task in practice. A general and simple online identification method, namely Selective Recursive Kernel Learning (SRKL), is proposed for multi-input–multi-output (MIMO) systems with the nonlinear autoregressive with exogenous input form. A two-stage RKL online identification framework is first formulated, where the information contained by a sample (i.e., the new arriving or old useless one) can be introduced into and/or deleted from the model, recursively. Then, a sparsification strategy to restrict the model complexity is developed to guarantee all the output channels of the MIMO model accurate simultaneously. Specially, a …


Recognition Mediated Encapsulation And Isolation Of Flavin-Polymer Conjugates Using Dendritic Guest Moieties, C Subramani, G Yesilbag, Bj Jordan, Xn Li, A Khorasani, G Cooke, A Sanyal, Vm Rotello Feb 2010

Recognition Mediated Encapsulation And Isolation Of Flavin-Polymer Conjugates Using Dendritic Guest Moieties, C Subramani, G Yesilbag, Bj Jordan, Xn Li, A Khorasani, G Cooke, A Sanyal, Vm Rotello

Vincent Rotello

Diaminopyridine dendritic scaffolds encapsulate polymeric flavin via non-covalent interactions and demonstrate isolation of the redox moiety.


Positron And Electron Impact Double Ionization Of Argon: How 1st- And 2nd-Order Mechanisms Influence The Differential Electron Emission, Robert D. Dubois, O. G. De Lucio, J. Gavin Feb 2010

Positron And Electron Impact Double Ionization Of Argon: How 1st- And 2nd-Order Mechanisms Influence The Differential Electron Emission, Robert D. Dubois, O. G. De Lucio, J. Gavin

Physics Faculty Research & Creative Works

Double-to-single-ionization ratios for electron emission as a function of the angle are measured for 200, 500, and 1000 eV positron and electron impact on argon. Both the sign of the projectile charge and the impact energy are shown to influence the angular dependences. by combining these ratios for positron and electron impact, information about how first- and second-order double-ionization mechanisms interfere and contribute to the total differential electron emission at different collision velocities is obtained. © 2010 EPLA.


Long-Term And Seasonal Trends In Phytoplankton Production And Biomass In Tampa Bay, Florida., J.O. R. Johansson Feb 2010

Long-Term And Seasonal Trends In Phytoplankton Production And Biomass In Tampa Bay, Florida., J.O. R. Johansson

Reports

Phytoplankton production is a basic process in aquatic ecosystems that converts inorganic carbon into organic matter and provides an important indicator of trophic state. The City of Tampa Bay Study Group maintains a 32 year long monthly record of phytoplankton production rates and biomass (chlorophyll-a) in Hillsborough Bay (HB) and Middle Tampa Bay (MTB), and a recent record during the last nine years for Old Tampa Bay (OTB). Production is measured using the classic in situ 14C method with samples incubated vertically in the water column. Annual production rates during the most recent decade are about 410gCm-2 for HB, 350gCm-2 …


Analytical Beam Propagation Model For Clipped Focused-Gaussian Beams Using Vector Diffraction Theory, Glen D. Gillen, Christopher M. Seck, Shekhar Guha Feb 2010

Analytical Beam Propagation Model For Clipped Focused-Gaussian Beams Using Vector Diffraction Theory, Glen D. Gillen, Christopher M. Seck, Shekhar Guha

Physics

Vector diffraction theory is applied to the case of focused TEM00 Gaussian beams passing through a spatially limiting aperture in order to investigate the propagation of these clipped focused-Gaussian beams. Beam distributions at different axial distances show that a traditional M2 propagation model cannot be used for the propagation of clipped focus-Gaussian beams. Using Luneberg’s vector diffraction theory and Fresnel approximations, an analytical model for the on-axis transverse and longitudinal electric fields and intensity distributions is presented including predictions of the maximum obtainable intensity. In addition, an analytical expression is provided for the longitudinal component of the electric …


Chemically Directed Immobilization Of Nanoparticles Onto Gold Substrates For Orthogonal Assembly Using Dithiocarbamate Bond Formation, Mh Park, Xx Duan, Y Ofir, B Creran, D Patra, Xy Ling, J Huskens, Vm Rotello Feb 2010

Chemically Directed Immobilization Of Nanoparticles Onto Gold Substrates For Orthogonal Assembly Using Dithiocarbamate Bond Formation, Mh Park, Xx Duan, Y Ofir, B Creran, D Patra, Xy Ling, J Huskens, Vm Rotello

Vincent Rotello

Dithiocarbamate-mediated bond formation combined with soft lithography was used for the selective immobilization of amine-functionalized silica nanoparticles on gold substrates. The available amine groups on the upper surface of the immobilized silica nanoparticles were further utilized for postdeposition of additional materials including particles, dyes, and biomolecules. The robustness of dithiocarbamate-mediated immobilization enables orthogonal assembly on surfaces via selective removal of the masking thiol ligands using iodine vapor etching followed by further functionalization.


Coset: Cooperative Set Last Level Caches, Dongyuan Zhan, Hong Jiang, Sharad Seth Feb 2010

Coset: Cooperative Set Last Level Caches, Dongyuan Zhan, Hong Jiang, Sharad Seth

CSE Technical Reports

The speed gap between processors and DRAM remains a crit-ical performance bottleneck for contemporary computer systems, which necessitates an effective management of last level caches (LLC) to minimize expensive off-chip accesses. However, because all sets in a conventional set-associative cache design are statically assigned an equal number of blocks, the LLC capacity utilization can drastically diminish when the cache actually exhibits non-uniform capacity demands across the sets. To reveal the wide exis-tence of set-level non-uniformity of capacity demand in real appli-cations, this technical report first establishes an accurate metric for measuring individual sets’ capacity demands by developing a group of …


A Unified Theory Of Function Spaces And Hyperspaces: Local Properties, Szymon Dolecki, Frédéric D. Mynard Feb 2010

A Unified Theory Of Function Spaces And Hyperspaces: Local Properties, Szymon Dolecki, Frédéric D. Mynard

Department of Mathematical Sciences Faculty Publications

Many classically used function space structures (including the topology of pointwise convergence, the compact-open topology, the Isbell topology and the continuous convergence) are induced by a hyperspace structure counterpart. This scheme is used to study local properties of function space structures on C(X,R), such as character, tighntess, fan-tightness, strong fan-tightness, the Fr{\'e}chet property and some of its variants. Under mild conditions, local properties of C(X,R) at the zero function correspond to the same property of the associated hyperspace structure at X. The latter is often easy to characterize in terms of covering properties …


Doubly Connected Minimal Surfaces And Extremal Harmonic Mappings, Tadeusz Iwaniec, Leonid V. Kovalev, Jani Onninen Feb 2010

Doubly Connected Minimal Surfaces And Extremal Harmonic Mappings, Tadeusz Iwaniec, Leonid V. Kovalev, Jani Onninen

Mathematics - All Scholarship

The concept of a conformal deformation has two natural extensions: quasiconformal and harmonic mappings. Both classes do not preserve the conformal type of the domain, however they cannot change it in an arbitrary way. Doubly connected domains are where one first observes nontrivial conformal invariants. Herbert Groetzsch and Johannes C. C. Nitsche addressed this issue for quasiconformal and harmonic mappings, respectively. Combining these concepts we obtain sharp estimates for quasiconformal harmonic mappings between doubly connected domains. We then apply our results to the Cauchy problem for minimal surfaces, also known as the Bjorling problem. Specifically, we obtain a sharp estimate …


Water-Soluble Soa From Alkene Ozonolysis: Composition And Droplet Activation Kinetics Inferences From Analysis Of Ccn Activity, A. Asa-Awuku, A. Nenes, Song Gao, R. C. Flagan, John H. Seinfeld Feb 2010

Water-Soluble Soa From Alkene Ozonolysis: Composition And Droplet Activation Kinetics Inferences From Analysis Of Ccn Activity, A. Asa-Awuku, A. Nenes, Song Gao, R. C. Flagan, John H. Seinfeld

Chemistry and Physics Faculty Articles

Cloud formation characteristics of the water-soluble organic fraction (WSOC) of secondary organic aerosol (SOA) formed from the ozonolysis of alkene hydrocarbons (terpinolene, 1-methlycycloheptene and cycloheptene) are studied. Based on size-resolved measurements of CCN activity (of the pure and salted WSOC samples) we estimate the average molar volume and surface tension depression associated with the WSOC using Köhler Theory Analysis (KTA). Consistent with known speciation, the results suggest that the WSOC are composed of low molecular weight species, with an effective molar mass below 200 g mol−1. The water-soluble carbon is also surface-active, depressing surface tension 10–15% from that of pure …


Thermal Degradation Of High-Temperature Fluorinated Polyimide And Its Carbon Fiber Composite, Andrea D. Adamczak, Adam A. Spriggs, Danielle M. Fitch, Walid Awad, Charles A. Wilkie, Jaime C. Grunlan Feb 2010

Thermal Degradation Of High-Temperature Fluorinated Polyimide And Its Carbon Fiber Composite, Andrea D. Adamczak, Adam A. Spriggs, Danielle M. Fitch, Walid Awad, Charles A. Wilkie, Jaime C. Grunlan

Chemistry Faculty Research and Publications

No abstract provided.


Mathematical Sciences News, Georgia Southern University Feb 2010

Mathematical Sciences News, Georgia Southern University

Department of Mathematical Sciences News (2007-2021)

  • Mathematical Modeling Competition