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193,929 full-text articles. Page 5152 of 5158.

Association-Based Image Retrieval, Arun D. Kulkarni 2009 University of Texas at Tyler

Association-Based Image Retrieval, Arun D. Kulkarni

Arun Kulkarni

No abstract provided.


Phytoprotective Influence Of Bacteria On Growth And Cadmium Accumulation In The Aquatic Plant Lemna Minor, Julian Tyson, Lisa M. Stout, Elena N. Dodova, Klaus Nusslein 2009 University of Massachusetts - Amherst

Phytoprotective Influence Of Bacteria On Growth And Cadmium Accumulation In The Aquatic Plant Lemna Minor, Julian Tyson, Lisa M. Stout, Elena N. Dodova, Klaus Nusslein

Julian Tyson

Certain plants are known to accumulate heavy metals, and can be used in remediation of
polluted soil or water. Plant-associated bacteria, especially those that are metal tolerant,
may enhance the total amount of metal accumulated by the plant, but this process is still
unclear. In this study, we investigated metal enhancement vs. exclusion by plants, and the
phytoprotective role plant-associated bacteria might provide to plants exposed to heavy
metal. We isolated cadmium-tolerant bacteria from the roots of the aquatic plant Lemna
minor grown in heavy metal-polluted waters, and tested these isolates for tolerance to
cadmium. The efficiency of plants to ...


Thickness-Dependent Spontaneous Dewetting Morphology Of Ultrathin Ag Films, H Krishna, R Sachan, J Strader, C Favazza, Mikhail Khenner, Ramki Kalyanaraman 2009 Washington University in St Louis

Thickness-Dependent Spontaneous Dewetting Morphology Of Ultrathin Ag Films, H Krishna, R Sachan, J Strader, C Favazza, Mikhail Khenner, Ramki Kalyanaraman

Mikhail Khenner

We show here that the morphological pathway of spontaneous dewetting of ultrathin Ag films on SiO2 under nanosecond laser melting is found to be film thickness dependent. For films with thickness h between 2<=h<=9.5 nm, the intermediate stages of the morphology consisted of bicontinuous structures. For films 11.5<=h<=20 nm, the intermediate stages consisted of regularly-sized holes. Measurement of the characteristic length scales for different stages of dewetting as a function of film thickness showed a systematic increase, which is consistent with the spinodal dewetting instability over the entire thickness range investigated. This change in morphology with thickness is consistent with observations made previously for polymer films [A. Shama et al, Phys. Rev. Lett., v81, pp3463 (1998); R. Seemann et al, J. Phys. Cond. Matt., v13, pp4925, (2001)]. Based on the behavior of free energy curvature that incorporates intermolecular forces, we have estimated the morphological transition thickness for Ag on SiO2. The theory predictions agree well with observations for Ag. These results show that it is possible to form a variety of complex Ag nanomorphologies in a consistent manner, which could be useful in optical applications of Ag surfaces, such as in surface enhanced Raman sensing.


Instantaneous Velocities Of A Two Body Orbit, Eric Addison 2009 Utah State University

Instantaneous Velocities Of A Two Body Orbit, Eric Addison

Eric Addison

This short note will derive expressions for the instantaneous velocity of the components in a two-body elliptical Keplerian orbit.


Mid-Gap Electronic States In Zn1-Xmnxo., C. A. Johnson, Kevin R. Kittilstved, T. C. Kaspar, T. C. Droubay, S. A. Chambers, G. M. Salley, D. R. Gamelin 2009 University of Massachusetts - Amherst

Mid-Gap Electronic States In Zn1-Xmnxo., C. A. Johnson, Kevin R. Kittilstved, T. C. Kaspar, T. C. Droubay, S. A. Chambers, G. M. Salley, D. R. Gamelin

Kevin R. Kittilstved

Electronic absorption, magnetic circular dichroism (MCD), photoconductivity, and valence-band x-ray photoelectron (XPS) spectroscopic measurements were performed on epitaxial Zn1−xMnxO films to investigate the origin of the mid-gap band that appears upon introduction of Mn2+ into the ZnO lattice. Absorption and MCD spectroscopies reveal Mn2+-related intensity at energies below the first excitonic transition of ZnO, tailing well into the visible energy region, with an onset at ∼2.2 eV. Photoconductivity measurements show that excitation into this visible band generates mobile charge carriers, consistent with assignment as a Mn2+/3+ photoionization transition. XPS measurements reveal the presence of occupied Mn2 ...


Fast Function-On-Scalar Regression With Penalized Basis Expansions, Philip T. Reiss, Lei Huang, Maarten Mennes 2009 New York University

Fast Function-On-Scalar Regression With Penalized Basis Expansions, Philip T. Reiss, Lei Huang, Maarten Mennes

Lei Huang

Regression models for functional responses and scalar predictors are often fitted by means of basis functions, with quadratic roughness penalties applied to avoid overfitting. The fitting approach described by Ramsay and Silverman in the 1990s amounts to a penalized ordinary least squares (P-OLS) estimator of the coefficient functions. We recast this estimator as a generalized ridge regression estimator, and present a penalized generalized least squares (P-GLS) alternative. We describe algorithms by which both estimators can be implemented, with automatic selection of optimal smoothing parameters, in a more computationally efficient manner than has heretofore been available. We discuss pointwise confidence intervals ...


On K4 Of The Gaussian And Eisenstein Integers, Mathieu Dutour Sikiric, Herbert Gangl, Paul Gunnells, Jonathan Hanke, Achill Schürmann, Dan Yasaki 2009 University of Massachusetts - Amherst

On K4 Of The Gaussian And Eisenstein Integers, Mathieu Dutour Sikiric, Herbert Gangl, Paul Gunnells, Jonathan Hanke, Achill Schürmann, Dan Yasaki

Paul Gunnells

Abstract. In this paper we investigate the structure of the algebraic K-groups K4(Z[i]) and K4(Z[ρ]), where i := √ −1 and ρ := (1 + √ −3)/2. We exploit the close connection between homology groups of GLn(R) for n 6 5 and those of related classifying spaces, then compute the former using Voronoi’s reduction theory of positive definite quadratic and Hermitian forms to produce a very large finite cell complex on which GLn(R) acts. Our main results are (i) K4(Z[i]) is a finite abelian 3-group, and (ii) K4(Z[ρ]) is trivial.


Observation Of Long-Range Near-Side Angular Correlations In Proton-Proton Collisions At The Lhc, stefan spanier 2009 University of Tennessee - Knoxville

Observation Of Long-Range Near-Side Angular Correlations In Proton-Proton Collisions At The Lhc, Stefan Spanier

stefan spanier

Results on two-particle angular correlations for charged particles emitted in proton-proton collisions at center-of-mass energies of 0.9, 2.36, and 7 TeV are presented, using data collected with the CMS detector over a broad range of pseudorapidity (eta) and azimuthal angle (phi). Short-range correlations in Delta(eta), which are studied in minimum bias events, are characterized using a simple "independent cluster" parametrization in order to quantify their strength (cluster size) and their extent in eta (cluster decay width). Long-range azimuthal correlations are studied differentially as a function of charged particle multiplicity and particle transverse momentum using a 980 inverse ...


Derivation Of Initial Velocities For A Two-Body Orbit In The Barycenter Frame, Eric Addison 2009 Utah State University

Derivation Of Initial Velocities For A Two-Body Orbit In The Barycenter Frame, Eric Addison

Eric Addison

The readily available information for two body orbits generally refers to the one dimensional, reduced mass case. Information about initial conditions in the barycenter frame is not easily found. In order to derive the initial velocities required for a two-body orbit in the barycenter frame, the momentum of the reduced mass can be used.


Quantifying The Effect Of Performance-Enhancing Drug Use On Fastball Velocity In Major League Baseball, Vittorio Addona, J. Roth 2009 Macalester College

Quantifying The Effect Of Performance-Enhancing Drug Use On Fastball Velocity In Major League Baseball, Vittorio Addona, J. Roth

Vittorio Addona

No abstract provided.


A Categorical Semantics For Fuzzy Predicate Logic, Lawrence N. Stout 2009 Illinois Wesleyan University

A Categorical Semantics For Fuzzy Predicate Logic, Lawrence N. Stout

Lawrence N. Stout

The object of this study is to look at categorical approaches to many valued logic, both propositional and predicate, to see how different logical properties result from different parts of the situation. In particular, the relationship between the categorical fabric I introduced at Linz in 2004 and the Fuzzy Logics studied by Hajek (2003) [5], Esteva et al. (2003) [1], and Hajek (1998) [4], comes from restricting the kind of structures used for truth values. We see how the structure of the various kinds of algebras shows up in the categorical logic, giving a variant on natural deduction for these ...


Sonic Anemometer Calibrations, Michael Negale, David Cook 2009 Utah State University

Sonic Anemometer Calibrations, Michael Negale, David Cook

Michael Negale

Initial conditions and boundary conditions are important for climate and atmospheric modeling. In order to get correct initial and boundary conditions, correct measurements need to be made. The eddy correlation flux measurement system (ECOR) is one such system that measures fluxes in momentum, sensible heat, latent heat, and carbon dioxide (CO2). These fluxes are calculated using the eddy covariance technique, which involves wind components, air temperature, water vapor, and CO2 concentration. The ECOR uses a fast response three-dimensional wind sensor, sonic anemometer (SA), to measure wind components and speed of sound, which is used to derive the air temperature. The ...


Origins Of The Extragalactic Background At 1mm From A Combined Analysis Of The Aztec And Mambo Data In Goods-N, Kyle Penner, Alexandra Pope, Edward L. Chapin, Thomas R. Greve, Frank Bertoldi, Mark Brodwin, Ranga-Ram Chary, Christopher J, Conselice, Kristen Coppin, Mauro Giavalisco, David H. Hughes, Rob J. Ivison, Thushara Perera, Douglas Scott, Kimberly Scott, Grant Wilson 2009 University of Massachusetts - Amherst

Origins Of The Extragalactic Background At 1mm From A Combined Analysis Of The Aztec And Mambo Data In Goods-N, Kyle Penner, Alexandra Pope, Edward L. Chapin, Thomas R. Greve, Frank Bertoldi, Mark Brodwin, Ranga-Ram Chary, Christopher J, Conselice, Kristen Coppin, Mauro Giavalisco, David H. Hughes, Rob J. Ivison, Thushara Perera, Douglas Scott, Kimberly Scott, Grant Wilson

Thushara A. Perera

We present a study of the cosmic infrared background, which is a measure of the dust obscured activity in all galaxies in the Universe. We venture to isolate the galaxies responsible for the background at 1mm; with spectroscopic and photometric redshifts we constrain the redshift distribution of these galaxies. We create a deep 1.16mm map (sigma ~ 0.5mJy) by combining the AzTEC 1.1mm and MAMBO 1.2mm datasets in GOODS-N. This combined map contains 41 secure detections, 13 of which are new. By averaging the 1.16mm flux densities of individually undetected galaxies with 24um flux densities > 25uJy ...


Excited States In The Large Density Limit: A Variational Approach, MP Coles, DE Pelinovsky, PG Kevrekidis 2009 University of Massachusetts - Amherst

Excited States In The Large Density Limit: A Variational Approach, Mp Coles, De Pelinovsky, Pg Kevrekidis

Panos Kevrekidis

Excited states of Bose–Einstein condensates are considered in the large density limit of the Gross–Pitaevskii equation with repulsive inter-atomic interactions and a harmonic potential. The relative dynamics of dark solitons (density dips on the localized condensate) with respect to the harmonic potential and to each other is approximated using the averaged Lagrangian method. This permits a complete characterization of the equilibrium positions of the dark solitons as a function of the chemical potential. It also yields an analytical handle on the oscillation frequencies of dark solitons around such equilibria. The asymptotic predictions are generalized for an arbitrary number ...


Pleistocene To Present North Andean “Escape”, James N. Kellogg, Obi Egbue 2009 Dept. Earth & Ocean Sci. Univ. S. Carolina, SC 29208

Pleistocene To Present North Andean “Escape”, James N. Kellogg, Obi Egbue

James N Kellogg

This study compiles 20 published field geologic estimates of displacement rates for the northern Andes, such as displaced glacial moraines and offset pyroclastic flow, and compares them to published Global Positioning System (GPS) measurements. Dated displacements compiled in this study were obtained from the Gulf of Guayaquil, Pallatanga, Chingual-la Sofia, and Cayambe-Afiladores-Sibundoy fault systems in Ecuador and southern Colombia and the Boconó fault system in Venezuela. Right-lateral slip estimates on the individual fault segments range from 2 mm/a to 10 mm/a. The mean estimated geologic slip rate for the last 86,000 years is 7.6 mm/a ...


A Snapshot Of Results Of The Survey Study On Rfid Technology, S. F. Wamba 2009 University of Wollongong

A Snapshot Of Results Of The Survey Study On Rfid Technology, S. F. Wamba

Dr Samuel Fosso Wamba

No abstract provided.


The Construction And Analysis Of Marker Gene Libraries, S.M. Short, F. Chen, Steven Wilhelm 2009 University of Tennessee, Knoxville

The Construction And Analysis Of Marker Gene Libraries, S.M. Short, F. Chen, Steven Wilhelm

Steven Wilhelm

Marker genes for viruses are typically amplified from aquatic samples to determine whether specific viruses are present in the sample, or to examine the diversity of a group of related viruses. In this chapter, we will provide an overview of common methods used to amplify, clone, sequence, and analyze virus marker genes, and will focus our discussion on viruses infecting algae, bacteria, and heterotrophic flagellates. Within this chapter, we endeavor to highlight critical aspects and components of these methods. To this end, instead of providing a detailed experimental protocol for each of the steps involved in examining virus marker gene ...


A Prospective Cohort Study Of Modifiable Risk Factors For Gestational Diabetes Among Hispanic Women: Design And Baseline Characteristics, Lisa Chasen-Taber, R. T. Fortner, A. Gollenberg, John Buonaccorsi, N. Dole, G. Markenson 2009 University of Massachusetts - Amherst

A Prospective Cohort Study Of Modifiable Risk Factors For Gestational Diabetes Among Hispanic Women: Design And Baseline Characteristics, Lisa Chasen-Taber, R. T. Fortner, A. Gollenberg, John Buonaccorsi, N. Dole, G. Markenson

John Buonaccorsi

OBJECTIVES: Women diagnosed with gestational diabetes mellitus (GDM) are at high risk for future diabetes, with rates of GDM consistently higher in Hispanic than non-Hispanic white women. Currently recognized risk factors for GDM are absent in up to half of affected women, and studies addressing modifiable risk factors for GDM in Hispanic women are sparse. METHODS: Proyecto Buena Salud is an ongoing prospective cohort study of Hispanic women in Massachusetts designed to assess physical activity, psychosocial stress, and GDM risk. Bilingual interviewers recruit prenatal care patients early in pregnancy and assess activity, trait anxiety, perceived stress, and depressive symptoms using ...


Using Twitter To Demonstrate Basic Concepts From Network Analysis, Matt Bogard 2009 Western Kentucky University

Using Twitter To Demonstrate Basic Concepts From Network Analysis, Matt Bogard

Matt Bogard

Social network analysis focuses on finding patterns in interactions between people or entities. These patterns may be described in the form of a network. Network analysis in general has many applications including models of student integration and persistence, business to business supply chains, terrorist cells, or analysis of social media such as Facebook and Twitter. This presentation provides a reference for basic concepts from social network analysis with examples using tweets from Twitter.


Spectral Decomposition Of Kac-Murdock-Szego Matrices, William F. Trench 2009 Trinity University

Spectral Decomposition Of Kac-Murdock-Szego Matrices, William F. Trench

William F. Trench

No abstract provided.


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