Digital Commons Network^™

New Evidence Suggests Southern China As A Common Source Of Multiple Clusters Of Highly Pathogenic H5n1 Avian Influenza Virus, Bin Wu, Chengmin Wang, Guoying Dong, Yunhai Guo, Dale L. Nolte, Thomas Jude Deliberto, Jianguo Xu, Mingxing Duan, Hongxuan He

United States Department of Agriculture Wildlife Services: Staff Publications

Highly pathogenic H5N1 avian influenza is considered an avian disease, although there is some evidence of limited human-to-human transmission of the virus. A global effort is underway to control or eradicate the highly pathogenic H5N1 avian influenza virus in poultry and prevent human exposure, both of which may also reduce the risk of pandemic emergence. Hemagglutinin gene sequences from 215 human H5N1 influenza viruses were used to trace the source and dispersal pattern of human H5N1 influenza viruses on a global scale. A mutation network and phylogenetic analyses of the hemagglutinin gene show that human H5N1 influenza viruses can be …

A Model Of Tuberculosis Transmission And Intervention Strategies In An Urban Residential Area, Elsje Pienaar, Aaron M. Fluitt, Scott E. Whitney, Alison G. Freifeld, Hendrik J. Viljoen

Department of Chemical and Biomolecular Engineering: Faculty Publications

The model herein aims to explore the dynamics of the spread of tuberculosis (TB) in an informal settlement or township. The population is divided into households of various sizes and also based on commuting status. The model dynamics distinguishes between three distinct social patterns: the exposure of commuters during travel, random diurnal interaction and familial exposure at night. Following the general SLIR models, the population is further segmented into susceptible (S), exposed/latently infected (L), active/infectious (I), and recovered (R) individuals. During the daytime, commuters travel on public transport, while non-commuters randomly interact in the community to mimic chance encounters with …

Effect Of Magnetron Frequency On Heating Pattern In Domestic Oven, Sohan Birla, Krishnamoorthy Pitchai, Jeyamkondan Subbiah, David D. Jones

Department of Agricultural and Biological Systems Engineering: Presentations and White Papers

In this study a computer model was developed to simulate microwave heating of a model food with a range of magnetron frequencies. The range was decided upon performing the frequency spectrum analysis of microwave leakage from the microwave oven. Simulation results showed that the magnetron input as sinusoidal frequency from 2.44 GHz to 2.48 GHz generates different heating profiles. The simulated heating profiles were compared with experimental heating profiles obtained by using an IR camera. None of simulations with individual frequency exactly matches with experimental temperature profile. The closet match between simulated and observed temperature profiles was found with 2.46 …

Modeling Changes In Biomass Composition During Microwave-Based Alkali Pretreatment Of Switchgrass, Deepak R. Keshwani, Jay J. Cheng

Department of Agricultural and Biological Systems Engineering: Faculty Publications

This study used two different approaches to model changes in biomass composition during microwave-based pretreatment of switchgrass: kinetic modeling using a time-dependent rate coefficient, and a Mamdani-type fuzzy inference system. In both modeling approaches, the dielectric loss tangent of the alkali reagent and pretreatment time were used as predictors for changes in amounts of lignin, cellulose, and xylan during the pretreatment. Training and testing data sets for development and validation of the models were obtained from pretreatment experiments conducted using 1–3% w/v NaOH (sodium hydroxide) and pretreatment times ranging from 5 to 20 minutes. The kinetic modeling approach for lignin …

Extrusion Systems: Design, Qi Fang, Milford Hanna

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Extrusion processing is applied widely because of its versatility and the fact that no waste streams, other than some heat, are generated. The versatility is a result of the way extruders are designed, in terms of the way preconditioning and postprocessing operations can be added with ease, and in terms of the wide range of processing conditions that can be generated through the selection of barrel, screw, and die options and operating conditions, such as temperature, screw speed, and feed moisture content.

Nonequilibrium Thermodynamics Modeling Of Coupled Biochemical Cycles In Living Cells, Yaşar Demirel

Yaşar Demirel Publications

Living cells represent open, nonequilibrium, self organizing, and dissipative systems maintained with the continuous supply of outside and inside material, energy, and information flows. The energy in the form of adenosine triphosphate is utilized in biochemical cycles, transport processes, protein synthesis, reproduction, and performing other biological work. The processes in molecular and cellular biological systems are stochastic in nature with varying spatial and time scales, and bounded with conservation laws, kinetic laws, and thermodynamic constraints, which should be taken into account by any approach for modeling biological systems. In component biology, this review focuses on the modeling of enzyme kinetics …

Incorporating Genomics And Bioinformatics Across The Life Sciences Curriculum, Jayna L. Ditty, Christopher A. Kvaal, Brad Goodner, Sharyn K. Freyermuth, Cheryl Bailey, Robert A. Britton, Stuart G. Gordon, Sabine Heinhorst, Kelynne Reed, Zhaohui Xu, Erin R. Sanders-Lorenz, Seth Axen, Edwin Kim, Mitrick Johns, Kathleen Scott, Cheryl A. Kerfeld

Department of Biochemistry: Faculty Publications

Undergraduate life sciences education needs an overhaul, as clearly described in the National Research Council of the National Academies’ publication BIO 2010: Transforming Undergraduate Education for Future Research Biologists. Among BIO 2010’s top recommendations is the need to involve students in working with real data and tools that reflect the nature of life sciences research in the 21st century [1]. Education research studies support the importance of utilizing primary literature, designing and implementing experiments, and analyzing results in the context of a bona fide scientific question [1–12] in cultivating the analytical skills necessary to become a scientist. Incorporating these …

Contributions Of Demography And Dispersal Parameters To The Spatial Spread Of A Stage-Structured Insect Invasion, Tom E. X. Miller, Brigitte Tenhumberg

School of Biological Sciences: Faculty Publications

Stage-structured models that integrate demography and dispersal can be used to identify points in the life cycle with large effects on rates of population spatial spread, information that is vital in the development of containment strategies for invasive species. Current challenges in the application of these tools include: (1) accounting for large uncertainty in model parameters, which may violate assumptions of ‘‘local’’ perturbation metrics such as sensitivities and elasticities, and (2) forecasting not only asymptotic rates of spatial spread, as is usually done, but also transient spatial dynamics in the early stages of invasion. We developed an invasion model for …

Ignoring Population Structure Can Lead To Erroneous Predictions Of Future Population Size, Brigitte Tenhumberg

School of Biological Sciences: Faculty Publications

Predictions of future population size often assume population structures are stable. Are we missing the boat if we ignore the occurrence of unstable or transient dynamics?

Agricultural crops are regularly infested with insect pests whose population size can reach outbreak densities in some years, causing considerable income loss to farmers. In general, the risk of pest outbreaks is highest when insects disperse to crop fields early in the growing season and the population growth rate is high. The population growth rate measures how much the population size (i.e., number of individuals of a species in a defined area) changes per …

Structured Population Dynamics: An Introduction To Integral Modeling, Joseph Briggs, Kathryn Dabbs, Michael Holm, Joan Lubben, Richard Rebarber, Brigitte Tenhumberg, Daniel Riser-Espinoza

School of Biological Sciences: Faculty Publications

In this article we illuminate the differences and similarities between matrix population models and integral population models for single-species stage structured populations. We illustrate the use of integral models with an application to Platte thistle, following Rose et al. [22], showing how the model is determined by basic life history functions. PPMs are ubiquitous in ecology, but for many purposes an IPM might be easier and/or more accurate to use. In TABLE 1 we summarize the similarities between PPMs and IPMs. In order to compare the predictions for PPMs and IPMs, enough data must be available to find the parameters …

Mate Choice And Learning, Eileen Hebets, Laura Sullivan-Beckers

Eileen Hebets Publications

While an individual’s genetic framework is a major contributor in determining its eventual mate choice, the role of the environment in further influencing mating decisions has long been recognized. Animals gather information from the environment throughout life, and in some cases, may apply this information to increase their odds of obtaining a high-quality mate. In short, these individuals learn. Moreover, such learning can have a social component. “Social learning” is a general term that describes any learning based on observing, interacting with, and/or imitating others in a social context. Social learning can transmit information vertically, generation to generation (e.g., parent …

Picosecond Electron Diffraction From Molecules Aligned By Dissociation, Martin Centurion, Peter Reckenthaeler, Ferenc Krausz, Ernst E. Fill

Martin Centurion Publications

In gas electron diffraction an averaging over statistical directions of the molecules takes place. This results in diffraction patterns in the form of isotropic rings which yield information only on the radial distribution function displaying the inter-atomic distances. We demonstrate that by dissociating molecules with linearly polarized light the pattern becomes anisotropic. In the experiments the iodide C₂F₄I₂ is dissociated and molecular difference intensities and difference radial distribution curves are measured for directions parallel and perpendicular to the direction of polarization. With picosecond temporal resolution the curves clearly demonstrate transient anisotropy and its decay by …

Dissociative Electron Attachment In Nonplanar Chlorocarbons With Π*/Σ*-Coupled Molecular Orbitals, Kayvan Aflatooni, Gordon A. Gallup, Paul Burrow

Paul Burrow Publications

Total absolute cross sections for the dissociative electron attachment (DEA) process are reported for a series of nonplanar ethylenic and phenylic compounds monosubstituted with (CH₂)_nCl groups, where n=1–4. Coupling between the local π^* molecular orbitals provided by the unsaturated moieties and the σ^* (C-Cl) orbital is thus examined as a function of the separation of these groups. In particular, the coupling is viewed from the perspective of the interacting temporary negative ions formed by short lived occupation of these orbitals and their decay into the DEA channel. A theoretical treatment of “remote” bond breaking, …

Vibrational Properties Of Ferroelectric Β-Vinylidene Fluoride Polymers And Oligomers, Serge M. Nakhmanson, Rafal Korlacki, J. Travis Johnston, Stephen Ducharme, Zhongxin Ge, James M. Takacs

Stephen Ducharme Publications

We utilize a plane-wave density-functional theory approach to investigate the vibrational properties of the all-trans ferroelectric phase of poly(vinylidene fluoride) (β-PVDF) showing that its stable state corresponds to the Ama2 structure with ordered dihedral tilting of the VDF monomers along the polymer chains. We then combine our theoretical analysis with IR spectroscopy to examine vibrations in oligomer crystals that are structurally related to the β-PVDF phase. We demonstrate that these materials—which can be grown in a highly crystalline form—exhibit IR activity similar to that of β-PVDF, making them an attractive choice for the studies of electroactive phenomena and phase transitions …

Why Ferroelectric Polyvinylidene Fluoride Is Special, Matt Poulsen, Stephen Ducharme

Stephen Ducharme Publications

Ferroelectric polymers entail a number of constraints, which together limit the useful compositional variations. These constraints include the following: a stable molecular dipole moment, compact crystal structure, conformational flexibility, and minimal steric hindrance. They are well satisfied by the prototype ferroelectric polymer, polyvinylidene fluoride, and yet almost every other conceivable molecular structure is limited by comparison.

Ab Initio Calculations And Ellipsometry Measurements Of The Optical Properties Of The Layered Semiconductor In4Se3, L. Makinistian, E. A. Albanesi, N. V. Gonzalez Lemus, A. G. Petukhov, D. Schmidt, Eva Schubert, M. Schubert, Yaroslav B. Losovyj, P. Galiy, Peter A. Dowben

Peter Dowben Publications

In this work, we present a thorough study of the optical properties of the layered orthorhombic compound In₄Se₃. The dielectric function—real and imaginary parts, the complex refraction index, the reflectivity, the absorption coefficient, and the conductivity of In₄Se₃ were calculated with the inclusion of the spin-orbit interaction, using an ab initio FP-LAPW method based on DFT. Also, generalized ellipsometry was employed for more precise measurement of the anisotropic dielectric functions for polarization along crystal a, b, and c axes of orthorhombic absorbing In₄Se₃ single crystals cut approximately parallel to …

The Local Structure Of Transition Metal Doped Semiconducting Boron Carbides, Jing Liu, Guangfu Luo, Wai-Ning Mei, Orhan Kizilkaya, Eric D. Shepherd, Jennifer I. Brand, Peter A. Dowben

Peter Dowben Publications

Transition metal doped boron carbides produced by plasma enhanced chemical vapour deposition of orthocarborane (closo-1,2-C₂B₁₀H₁₂) and 3d metal metallocenes were investigated by performing K-edge extended x-ray absorption fine structure and x-ray absorption near edge structure measurements. The 3d transition metal atom occupies one of the icosahedral boron or carbon atomic sites within the icosahedral cage. Good agreement was obtained between experiment and models for Mn, Fe and Co doping, based on the model structures of two adjoined vertex sharing carborane cages, each containing a transition metal. The local spin configurations of all …

Double Parton Interactions In Γ = 3 Jet Events In Pp Collisions At √S = 1.96 Tev, V. M. Abazov, Kenneth A. Bloom, Gregory Snow, D0 Collaboration

Kenneth Bloom Publications

We have used a sample of γ + 3 jets events collected by the D0 experiment with an integrated luminosity of about 1 fb^-1 to determine the fraction of events with double parton scattering (f_DP) in a single pp collision at √s = 1.96 TeV. The DP fraction and effective cross section (τ_eff ), a process-independent scale parameter related to the parton density inside the nucleon, are measured in three intervals of the second (ordered in p_T) jet transverse momentum p^jet2_T within the range 15 ≤ p^jet2_T ≤ …

Search For The Standard Model Higgs Boson In The Zh → ΝνBb Channel In 5.2 Fb-1 Of Pp Collisions At √S = 1.96 Tev, V. M. Abazov, Kenneth A. Bloom, Gregory Snow, D0 Collaboration

Kenneth Bloom Publications

A search is performed for the standard model Higgs boson in 5.2 fb^-1 of pp collisions at √s = 1.96 TeV, collected with the D0 detector at the Fermilab Tevatron Collider. The final state considered is a pair of b jets and large missing transverse energy, as expected from pp → ZH → ννbb production. The search is also sensitive to the WH → ℓνbb channel when the charged lepton is not identified. For a Higgs boson mass of 115 GeV, a limit is set at the 95% C.L. on the cross section multiplied by branching …

Search For The Associated Production Of A B Quark And A Neutral Supersymmetric Higgs Boson That Decays Into Τ Pairs, V. M. Abazov, Kenneth A. Bloom, Gregory Snow, D0 Collaboration

Kenneth Bloom Publications

We report results from a search for production of a neutral Higgs boson in association with a b quark. We search for Higgs decays to τ pairs with one τ subsequently decaying to a muon and the other to hadrons. The data correspond to 2.7 fb^-1 of pp collisions recorded by the D0 detector at √s = 1.96 TeV. The data are found to be consistent with background predictions. The result allows us to exclude a significant region of parameter space of the minimal supersymmetric model.

Combination Of Tevatron Searches For The Standard Model Higgs Boson In The W+W- Decay Mode, V. M. Abazov, Kenneth A. Bloom, Gregory Snow, D0 Collaboration

Kenneth Bloom Publications

We combine searches by the CDF and D0 Collaborations for a Higgs boson decaying to W⁺W^-. The data correspond to an integrated total luminosity of 4.8 (CDF) and 5.4 (D0) fb^-1 of pp collisions at √s = 1.96 TeV at the Fermilab Tevatron collider. No excess is observed above background expectation, and resulting limits on Higgs boson production exclude a standard model Higgs boson in the mass range 162–166 GeV at the 95% C.L.

Debugging Data Transfers In Cms, G. Gagliesi, S. J. Belforte, Kenneth A. Bloom, B. Bockelman, D. Bonacorsi, I. Fisk, J. Flix, J. Hernandez, J. D'Hondt, M. Kadastik, J. Klem, O. Kodolova, C.-M. Kuo, J. Letts, J. Maes, N. Magini, S. Metson, J. Piedra, N. Pukhaeva, L. Turra, S. Sõnajalg, Y. Wu, P. Van Mulders, I. Villella, F. Würthwein

Kenneth Bloom Publications

The CMS experiment at CERN is preparing for LHC data taking in several
computing preparation activities. In early 2007 a traffic load generator infrastructure for distributed data transfer tests was designed and deployed to equip the WLCG tiers which support the CMS virtual organization with a means for debugging, load-testing and commissioning data transfer routes among CMS computing centres. The LoadTest is based upon PhEDEx as a reliable, scalable data set replication system. The Debugging Data Transfers (DDT) task force was created to coordinate the debugging of the data transfer links. The task force aimed to commission most crucial transfer …

Soil-Transmitted Helminthiases: Implications Of Climate Change And Human Behavior, Haylee J. Weaver, John M. Hawdon, Eric P. Hoberg

Harold W. Manter Laboratory of Parasitology: Faculty Publications

Soil-transmitted helminthiases (STHs) collectively cause the highest global burden of parasitic disease after malaria and are most prevalent in the poorest communities, especially in sub-Saharan Africa. Climate change is predicted to alter the physical environment through cumulative impacts of warming and extreme fluctuations in temperature and precipitation, with cascading effects on human health and wellbeing, food security and socioeconomic infrastructure. Understanding how the spectrum of climate change effects will influence STHs is therefore of critical importance to the control of the global burden of human parasitic disease. Realistic progress in the global control of STH in a changing climate requires …

Probing Equilibrium By Nonequilibrium Dynamics: Aging In Co/Cr Superlattices, Tathagata Mukherjee, M. Pleimling, Christian Binek

Christian Binek Publications

Magnetization relaxation is investigated in a structurally ordered magnetic Co/Cr superlattice. Tailored nanoscale periodicity creates mesoscopic spatial magnetic correlations with slow relaxation dynamics when quenching the system into a nonequilibrium state. Magnetization transients are measured after exposing the heterostructure to a magnetic set field for various waiting times. Scaling analysis reveals an asymptotic powerlaw behavior in accordance with a full aging scenario. The temperature dependence of the relaxation exponent shows pronounced anomalies at the equilibrium phase transitions of the antiferromagnetic superstructure and the ferromagnetic to paramagnetic transition of the Co layers. The latter leaves only weak fingerprints in the equilibrium …

Isomer Identification And Resolution In Small Gold Clusters, Wei Huang, Rhitankar Pal, Lei-Ming Wang, Xiao Cheng Zeng, Lai-Sheng Wang

Xiao Cheng Zeng Publications

A variety of experimental techniques are used to resolve energetically close isomers of Au_{7 ⁻} and Au_{8 ⁻} by combining photoelectron spectroscopy and ab initio calculations. Two structurally distinct isomers are confirmed to exist in the cluster beam for both clusters. Populations of the different isomers in the cluster beam are tuned using Ar-tagging, O₂-titration, and isoelectronic atom substitution by Cu and Ag. A new isomer structure is found for Au_{7 ⁻}, which consists of a triangular Au₆ unit with a dangling Au atom. Isomer-specific photoelectron spectra of Au_{8 ⁻} are obtained …

V371 Per — A Thick-Disk, Short-Period F/1o Cepheid, P. Wils, A. A. Henden, S. Kleidis, Edward G. Schmidt, D. L. Welch

Edward Schmidt Publications

V371 Per was found to be a double-mode Cepheid with a fundamental mode period of 1.738 days, the shortest among Galactic beat Cepheids, and an unusually high period ratio of 0.731, while the other Galactic beat Cepheids have period ratios between 0.697 and 0.713. The latter suggests that the star has a metallicity [Fe/H] between −1 and −0.7. The derived distance from the Galactic plane places it in the thick disk or the Halo, while all other Galactic beat Cepheids belong to the thin disk. There are indications from historical data that both the fundamental and first overtone periods have …

Using Python To Program Lego Mindstorms Robots: The Pynxc Project, Brian S. Blais

Science and Technology Department Faculty Journal Articles

LEGO MINDSTORMS® NXT (Lego Group, 2006) is a perfect platform for introducing programming concepts, and is generally targeted toward children from age 8-14. The language which ships with the MINDSTORMS®, called NXTg, is a graphical language based on LabVIEW (Jeff Kodosky, 2010). Although there is much value in graphical languages, such as LabVIEW, a text-based alternative can be targeted at an older audiences and serve as part of a more general introduction to modern computing. Other languages, such as NXC (Not Exactly C) (Hansen, 2010) and PbLua (Hempel, 2010), fit this description. Here we introduce PyNXC, a subset of the …

Technological-Personal-Environmental (Tpe) Framework: A Conceptual Model For Technology Acceptance At The Individual Level, Yijun Jiang, Dongyu Chen, Fujun Lai

Journal of International Technology and Information Management

This paper describes the development of the Technological-Personal-Environmental (TPE) framework, which explains individuals’ behaviors of technology acceptance. We argue that existing individual-level technology acceptance theories provide a valuable, but incomplete, understanding of individuals’ technology acceptance. By synthesizing extant technology acceptance models and theories, the proposed TPE delineates the individual-level technology acceptance from technological, personal, and environmental aspects. The proposed framework provides a wider angle to investigate individual-level technology acceptance.

Leadership Characteristics And Team Outcomes In The Development Of A Marketing Web Page, Garry L. White, Karen H. Smith

Journal of International Technology and Information Management

Team structures are changing under the pressures of e-commerce and globalization. Today teams have to manage the challenges of working across functional boundaries, such as marketing and web development. In such an environment, research in the disciplines of management and psychology have found that shared leadership among team members may be superior to traditional leadership by a single team member, but this notion has not been tested in the contexts of marketing and web development. This paper presents the results of an empirical study showing that teams with shared leadership exhibited better performance and greater member satisfaction than teams with …

An Excel Planning And Teaching Decision Aid For Bonner's Conceptual Framework, Freddie Choo, Kim Tan

Journal of International Technology and Information Management

Bonner (1999, 2008) prescribes a conceptual framework entitled “Choosing teaching methods based on learning objectives: An integrative framework” to plan and teach accounting. Bonner’s conceptual framework involves a holistic-mapping-process in which an instructor holistically maps a set of accounting learning objectives (ALO), general learning objectives (GLO), necessary conditions (NC), and teaching methods (TM). The scope of this paper is aimed at developing an Excel planning and teaching decision aid (EDA) for Bonner’s holistic-mapping- process. This EDA neither replaces nor supplants the conventional judgment-based planning and teaching process. By presenting and making the EDA available, perhaps accounting information systems researchers will …