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Science Today In Verse, Hope Leman

Sci-Tech News

No abstract provided.

Chemistry Division, Marie Fraties-Block

Sci-Tech News

No abstract provided.

Engineering Division, Pam Enrici

Sci-Tech News

No abstract provided.

Sci-Tech Book News Reviews, Susan Fingerman

Sci-Tech News

No abstract provided.

Quantification Of Heterosubtypic Immunity Between Avian Influenza Subtypes H3n8 And H4n6 In Multiple Avian Host Species, Kim M. Pepin, Kaci K. Vandalen, N. L. Mooers, J. W. Ellis, H. J. Sullivan, J. Jeffrey Root, Colleen T. Webb, A. B. Franklin, Susan A. Shriner

United States Department of Agriculture Wildlife Services: Staff Publications

Low-pathogenicity avian influenza virus (LPAIV) can lead to epizootics that cause economic losses in poultry or the emergence of human-infectious strains. LPAIVs experience a complex immunity landscape as they are endemic in numerous host species, and many antigenically distinct strains cocirculate. Prevention and control of emergence of detrimental strains requires an understanding of infection/transmission characteristics of the various subtypes in different hosts, including interactions between subtypes. In order to develop analytical frameworks for examining control efficacy, quantification of heterosubtypic immunity interactions is fundamental. However, these data are scarce, especially for wild avian subtypes in natural hosts. Consequently, in this study, …

Optimal Advance Detector Location For Green Termination Systems On High-Speed Isolated Rural Intersections, Lili Du, Anuj Sharma, Srinivas Peeta

Department of Civil and Environmental Engineering: Faculty Publications

This study seeks to identify the optimal location of an advance point traffic detector (APTD) to support green termination algorithms for enhanced dilemma zone protection systems at high-speed isolated signalized rural intersections. This is done by developing a nonlinear optimization model with the objective to maximize the opportunities to predict empty dilemma zones during a look-ahead time period subject to the prediction accuracy which is manifested through prediction efficiency and safety constraints in the model. The distance of the APTD from the stop bar of the intersection represents the decision variable. The Golden-Section line search algorithm combined with numerical integration …

Standoff Laser Interferometric Photoacoustic Spectroscopy For The Detection Of Explosives, Logan Marcus

Electronic Theses and Dissertations

There will unfortunately always be a pressing need to detect and identify explosive materials. Performing detection at a standoff distance is much safer and this is the impetus for this work. Photoacoustic spectroscopy is well suited to the task of explosive detection at a standoff distance. A detailed theory of the standoff measurement of the physical response of a system to photoacoustic excitation with an interferometric sensor has been constructed and tested. The use of this methodology to measure the standoff photoacoustic spectrum of TNT with an interferometric sensor has clearly been demonstrated. This methodology and the tested theory can …

An Ssvep Brain-Computer Interface: A Machine Learning Approach, Fei Teng

Electronic Theses and Dissertations

A Brain-Computer Interface (BCI) provides a bidirectional communication path for a human to control an external device using brain signals. Among neurophysiological features in BCI systems, steady state visually evoked potentials (SSVEP), natural responses to visual stimulation at specific frequencies, has increasingly drawn attentions because of its high temporal resolution and minimal user training, which are two important parameters in evaluating a BCI system. The performance of a BCI can be improved by a properly selected neurophysiological signal, or by the introduction of machine learning techniques. With the help of machine learning methods, a BCI system can adapt to the …

Impacts Of Ventilation Ratio And Vent Balance On Cooling Load And Air Flow Of Naturally Ventilated Attics, Shimin Wang, Zhigang Shen

Durham School of Architectural Engineering and Construction: Faculty Publications

The impacts of ventilation ratio and vent balance on cooling load and air flow of naturally ventilated attics are studied in this paper using an unsteady computational fluid dynamics (CFD) model. Buoyancy-driven turbulent ventilations in attics of gable-roof residential buildings are simulated for typical summer conditions. Ventilation ratios from 1/400 to 1/25 combined with both balanced and unbalanced vent configurations are investigated. The modeling results show that the air flows in the attics are steady and exhibit a general streamline pattern that is qualitatively insensitive to the variations in ventilation ratio and vent configuration. The predicted temperature fields are characterized …

The Impact Of Roof Pitch And Ceiling Insulation On Cooling Load Of Naturally-Ventilated Attics, Shimin Wang, Zhigang Shen, Linxia Gu

Durham School of Architectural Engineering and Construction: Faculty Publications

A 2D unsteady computational fluid dynamics (CFD) model is employed to simulate buoyancy-driven turbulent ventilation in attics with different pitch values and ceiling insulation levels under summer conditions. The impacts of roof pitch and ceiling insulation on the cooling load of gable-roof residential buildings are investigated based on the simulation of turbulent air flow and natural convection heat transfer in attic spaces with roof pitches from 3/12 to 18/12 combined with ceiling insulation levels from R-1.2 to R-40. The modeling results show that the air flows in the attics are steady and exhibit a general streamline pattern that is qualitatively …

A Field Study Of Wind Erosion Following A Grass Fire On The Llano Estacado Of North America, J.E. Stout

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Interactions between earth, wind, and fire have always played an important role in the formation and evolution of the level plains of the Llano Estacado of North America. The uppermost sediments of this vast region are aeolian deposits, formed by aeolian deposition into grassland vegetation. Grass cover enhances aeolian deposition by slowing near-surface winds and vegetation secures sediments once they are deposited. The benefits of grass cover, however, are lost when occasional fires remove protective vegetation fromfields. After a fire, the underlying soil surface becomes exposed and susceptible to wind erosion until the vegetative cover is re-established. The purpose of …

Indirect Effects Of Parasites In Invasions, Alison M. Dunn, Mark E. Torchin, Melanie J. Hatcher, Peter M. Kotanen, Dana M. Blumenthal, James E. Byers, Courtney A.C. Coon, Victor M. Frankel, Robert D. Holt, Ruth A. Hufbauer, Andrew R. Kanarek, Kristina A. Schierenbeck, Lorne M. Wolfe, Sarah E. Perkins

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

1. Introduced species disrupt native communities and biodiversity worldwide. Parasitic infections (and at times, their absence) are thought to be a key component in the success and impact of biological invasions by plants and animals. They can facilitate or limit invasions, and positively or negatively impact native species.

2. Parasites have not only direct effects on their hosts, but also indirect effects on the species with which their hosts interact. Indirect effects include density-mediated effects (resulting from parasite-induced reduction in host reproduction and survival) as well as trait-mediated indirect effects (resulting from parasite-induced changes in host phenotype, behavior or life …

Identification Of A Response Regulator Involved In Surface Attachment, Cell–Cell Aggregation, Exopolysaccharide Production And Virulence In The Plant Pathogen Xylella Fastidiosa, Tanja M. Voegel, Harshavardhan Doddapaneni, Davis W. Cheng, Hong Lin, Drake C. Stenger, Bruce C. Kirkpatrick, M. Caroline Roper

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Xylella fastidiosa, the causal agent of Pierce’s disease of grapevine, possesses several two-component signal transduction systems that allow the bacterium to sense and respond to changes in its environment. Signals are perceived by sensor kinases that autophosphorylate and transfer the phosphate to response regulators (RRs), which direct an output response, usually by acting as transcriptional regulators. In the X. fastidiosa genome, 19 RRs were found. A site-directed knockout mutant in one unusual RR, designated XhpT, composed of a receiver domain and a histidine phosphotransferase output domain, was constructed. The resulting mutant strain was analysed for changes in phenotypic traits …

E-Photosynthesis: A Comprehensive Dynamic Mechanistic Model Of C3 Photosynthesis: From Light Capture To Sucrose Synthesis, Xin-Guang Zhu, Yu Wang, Donald R. Ort, Stephen P. Long

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Photosynthesis is arguably the most researched of all plant processes. A dynamic model of leaf photosynthesis that includes each discrete process from light capture to carbohydrate synthesis, e-photosynthesis, is described. It was developed by linking and extending our previous models of photosystem II (PSII) energy transfer and photosynthetic C3 carbon metabolism to include electron transfer processes around photosystem I (PSI), ion transfer between the lumen and stroma, ATP synthesis and NADP reduction to provide a complete representation. Different regulatory processes linking the light and dark reactions are also included: Rubisco activation via Rubisco activase, pH and xanthophyll cycle-dependent non-photochemical …

A Note On Acoustic Propagation In Power-Law Fluids: Compact Kinks, Mild Discontinuities, And A Connection To Finite-Scale Theory, Dongming Wei

Mathematics Faculty Publications

Acoustic traveling waves in a class of viscous, power-lawfluids are investigated. Both bi-directional and unidirectional versions of the one-dimensional (1D), weakly-nonlinear equation of motion are derived; traveling wave solutions (TWS)s, special cases of which take the form of compact and algebraic kinks, are determined; and the impact of the bulk viscosity on the structure/nature of the kinks is examined. Most significantly, we point out a connection that exists between the power-law model considered here and the recently introduced theory of finite-scale equations.

Influence Of Damping On Hyperbolic Equations With Parabolic Degeneracy, Katarzyna Saxton, Ralph Saxton

Mathematics Faculty Publications

This paper examines the effect of damping on a nonstrictly hyperbolic 2 x 2 system. It is shown that the growth of singularities is not restricted as in the strictly hyperbolic case where dissipation can be strong enough to preserve the smoothness of solutions globally in time. Here, irrespective of the stabilizing properties of damping, solutions are found to break down in finite time on a line where two eigenvalues coincide in state space.

An H1 Model For Inextensible Strings, Stephen C. Preston, Ralph Saxton

Mathematics Faculty Publications

We study geodesics of the H¹ Riemannian metric (see article for equation) on the space of inextensible curves (see article for equation). This metric is a regularization of the usual L² metric on curves, for which the submanifold geometry and geodesic equations have been analyzed already. The H¹ geodesic equation represents a limiting case of the Pochhammer-Chree equation from elasticity theory. We show the geodesic equation is C^∞ in the Banach topology C¹ ([0,1], R²), and thus there is a smooth Riemannian exponential map. Furthermore, if we hold one of the curves fixed, …

Blow-Up Of Solutions To The Generalized Inviscid Proudman-Johnson Equation, Alejandro Sarria, Ralph Saxton

Mathematics Faculty Publications

For arbitrary values of a parameter --- finite-time blowup of solutions to the generalized, inviscid Proudman Johnson equation is studied via a direct approach which involves the derivation of representation formulae for solutions to the problem.

Critical Buckling Loads Of The Perfect Hollomon’S Power-Law Columns, Dongming Wei, Alejandro Sarria, Mohamed Elgindi

Mathematics Faculty Publications

In this work, we present analytic formulas for calculating the critical buckling states of some plastic axial columns of constant cross-sections. The associated critical buckling loads are calculated by Euler-type analytic formulas and the associated deformed shapes are presented in terms of generalized trigonometric functions. The plasticity of the material is defined by the Holloman’s power-law equation. This is an extension of the Euler critical buckling loads of perfect elastic columns to perfect plastic columns. In particular, critical loads for perfect straight plastic columns with circular and rectangular cross-sections are calculated for a list of commonly used metals. Connections and …

Some Generalized Trigonometric Sine Functions And Their Applications, Dongming Wei, Yu Liu, Mohamed B. Elgindi

Mathematics Faculty Publications

In this paper, it is shown that D. Shelupsky's generalized sine function, and various general sine functions developed by P. Drabek, R. Manasevich and M. Otani, P. Lindqvist, including the generalized Jacobi elliptic sine function of S. Takeuchi can be defined by systems of first order nonlinear ordinary differential equations with initial conditions. The structure of the system of differential equations is shown to be related to the Hamilton System in Lagrangian Mechanics. Numerical solutions of the ODE systems are solved to demonstrate the sine functions graphically. It is also demonstrated that the some of the generalized sine functions can …

On The Global Solvability Of A Class Of Fourth-Order Nonlinear Boundary Value Problems, M.B.M. Elgindi, Dongming Wei

Mathematics Faculty Publications

In this paper we prove the global solvability of a class of fourth-order nonlinear boundary value problems that govern the deformation of a Hollomon’s power-law plastic beam subject to an axial compression and nonlinear lateral constrains. For certain ranges of the acting axial compression force, the solvability of the equations follows from the monotonicity of the fourth order nonlinear differential operator. Beyond these ranges the monotonicity of the operator is lost. It is shown that, in this case, the global solvability may be generated by the lower order nonlinear terms of the equations for a certain type of constrains.

Travelling Wave Solutions Of Burgers' Equation For Gee-Lyon Fluid Flows, Dongming Wei, Ken Holladay

Mathematics Faculty Publications

In this work we present some analytic and semi-analytic traveling wave solutions of generalized Burger' equation for isothermal unidirectional flow of viscous non-Newtonian fluids obeying Gee-Lyon nonlinear rheological equation. The solution of Burgers' equation for Newtonian flow as a special case. We also derive estimates of shock thickness for non-Newtonian flows.

Impaired Object Tracking In Children With Chromosome 22q11.2 Deletion Syndrome, Margarita H. Cabaral, Elliott A. Beaton, Joel Stoddard, Tony J. Simon

Psychology Faculty Publications

Background:

Chromosome 22q11.2 Deletion Syndrome (22q11.2DS) occurs in approximately 1:4,000 live births with a complex and variable presentation that includes medical, socioemotional and psychological symptoms with intellectual impairment. Cognitive impairments in spatiotemporal and visuospatial attention have also been reported. However, maintenance of selective attention to dynamic and interacting objects has not been systematically investigated in children with 22q11.2DS.

Methods:

We used a multiple object tracking task to assay capacity and resolution performance of children with 22q11.2DS aged 7 to 14 years versus age-matched typically developing (TD) peers.

Results:

Children with 22q11.2DS but not TD children demonstrated impaired performance when task …

Do Not Resuscitate And Other Imperatives, Stacy B. Harrison

All NMU Master's Theses

No abstract provided.

Classification Of Mental Illness In The 18th Century: A Comparison Of The Nosologies Of Carl Linnaeus, Francois Bossier De Sauvages, Rudolpho Vogel And William Cullen, Heather Ann Munsche

All NMU Master's Theses

No abstract provided.

The Legendre Transform Of The Holst Action, Caixia Gao

Electronic Theses and Dissertations

I start with a short introduction on 3+1 ADM form and the tetrad form of General Relativity, then I review the Legendre transform of the Einstein-Hilbert action and the Palatini action. The Holst action is a generalization of the Palatini action by including a topological term. I derive Ashtekar's connection form directly from this action by doing the Legendre transformation rather than by a canonical transformation in the usual phase space. This is done in both Remmanian signature with half-flat connection and Lorentz signature with general Barbero-Immirzi parameter.

Functional Morphology Of The Sphyrnid Shark Cephalofoil: An Assessment Of The Hydrodynamic Lift Hypothesis Using Computational Fluid Dynamics, Matthew K. Gaylord

Electronic Theses and Dissertations

The hammerhead sharks (Family: Sphyrnidae) are all characterized by a conspicuous lateral expansion and dorsoventral flattening of the head forming a structure known as a cephalofoil, however, there is substantial morphological variation within the clade. Many theories have been proposed regarding the functional aspects of this structure. One of these is that it may produce beneficial dynamic lift as the shark swims (in similar fashion to the cambered wings found on many modern-day aircraft). As sharks do not possess a swim bladder, part of their energy intake is expended on simply maintaining vertical station in the water column. If indeed …

The Impact Of The User-It Artifact Interaction On Technology Implementation And Value: Mobile Social Networking And Mobile Social Capital, Donghyun Kim

Electronic Theses and Dissertations

Despite investment and cutting-edge features, the majority of new mobile phone subscribers have adopted low-cost handsets instead of the latest mobile devices (Karjaluoto et al., 2005). According to the U.S. Census Bureau report, only 37% of cell phone users selected a smartphone in 2007. The Census Bureau forecasted the figure would increase by less than 10% in 2008. However, only 24% of cell phone users owned a smartphone in 2010, 27 % in 2011 and 30% in 2012. Therefore, the purpose of this study is to propose a conceptual model of the impact of mobile social capital on mobile networks …

Multi-Configurational Investigation Of Thermolytic Pathways Of Highly Strained Ring Systems, Jeffrey Dwayne Veals

Electronic Theses and Dissertations

The isomerization pathways of model high energy structures are of interest because of their relation to high energy density fuels. Electron resonance has been found to greatly affect the relative activation barriers for several isomerization pathways, and the major goal of this research is to accurately describe its role in determining the relative barriers for strain energy release pathways. This research is centered around the potential energy surfaces (PES's) for ? bond breaking and ? bond rotation in these highly strained structures. Of particular interest was how would resonance and or electronegativity affect the allowed/disallonature of the activation barriers in …

Stochastic Models For Evolutionary Genetic Problems, Wei Liao

Electronic Theses and Dissertations

Two stochastic models are designed for answering evolutionary genetic problems. The first study shows that inbreeding-environment interactions increase extinction risk. The second research demonstrates that 1) the carrying capacity and initial population growth rate is critical to determine the population persistence time; 2) increasing the advantageous mutation rate reduces the extinction risk although its effects are usually shadoby population size and fitness; 3) the new mutation correlation among environments rises during the evolution process, but it has compromised effects on population fate. Being able to accurately estimate the persistence time of populations of endangered plants and animals is central to …