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2015

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Articles 661 - 690 of 12617

Full-Text Articles in Physical Sciences and Mathematics

Border-Collision Bifurcations Of Cardiac Calcium Cycling, Jacob Michael Kahle Dec 2015

Border-Collision Bifurcations Of Cardiac Calcium Cycling, Jacob Michael Kahle

Masters Theses

In this thesis, we study the nonlinear dynamics of calcium cycling within a cardiac cell. We develop piecewise smooth mapping models to describe intracellular calcium cycling in cardiac myocyte. Then, border-collision bifurcations that arise in these piecewise maps are investigated. These studies are carried out using both one-dimensional and two-dimensional models. Studies in this work lead to interesting insights on the stability of cardiac dynamics, suggesting possible mechanisms for cardiac alternans. Alternans is the precursor of sudden cardiac arrests, a leading cause of death in the United States.


Neutrino Signatures In Terrestrial Detectors From Two- And Three-Dimensional Core-Collapse Supernovae Simulations, Tanner Brooks Devotie Dec 2015

Neutrino Signatures In Terrestrial Detectors From Two- And Three-Dimensional Core-Collapse Supernovae Simulations, Tanner Brooks Devotie

Masters Theses

Core-collapse supernovae (CCSNe) are driven by neutrino emission and are the most prodigious sources of neutrinos in the Universe. Importantly, the neutrino radiation from CCSNe is emitted from deep in the explosion and can provide information about physical processes taking place in the newly-born neutron star at the heart of the event. We examine the four-flavor (i.e. νe, νe, νx and νx) [electron, muon and tau neutrinos along with their anti-matter counterparts] signature of CCSNe neutrino emission in various neutrino detector types. We use data from the multidimensional Chimera (Lentz et al., 2015) …


Extended Lindley Poisson Distribution, Mavis Pararai, Gayan Warahena-Liyanage, Broderick O. Oluyede Dec 2015

Extended Lindley Poisson Distribution, Mavis Pararai, Gayan Warahena-Liyanage, Broderick O. Oluyede

Department of Mathematical Sciences Faculty Publications

The Extended Lindley Poisson (ELP) distribution which is an extension of the extended Lindley distribution [2] is introduced and its properties are explored. This new distribution represents a more flexible model for the lifetime data. Some statistical properties of the proposed distribution including the shapes of the density, hazard rate functions, moments, Bonferroni and Lorenz curves are explored. Entropy measures and the distribution of the order statistics are given. The maximum likelihood estimation technique is used to estimate the model parameters and a simulation study is conducted to investigate the performance of the maximum likelihood estimates. Finally, we present applications …


Management's Perspective On Critical Success Factors Affecting Mobile Learning In Higher Education Institutions - An Empirical Study, Muasaad Alrasheedi, Luiz Fernando Capretz, Arif Raza Dec 2015

Management's Perspective On Critical Success Factors Affecting Mobile Learning In Higher Education Institutions - An Empirical Study, Muasaad Alrasheedi, Luiz Fernando Capretz, Arif Raza

Electrical and Computer Engineering Publications

Mobile learning (m-Learning) is considered to be one of the fastest growing learning platforms. The immense interest in m-Learning is attributed to the incredible rate of growth of mobile technology and its proliferation into every aspect of modern life. Despite this, m-Learning has not experienced a similar adoption rate in the education sector, chiefly higher education. Researchers have attempted to explain this anomaly by conducting several studies in the area. However, mostly the research in m-Learning is examined from the perspective of the students and educators. In this research, it is contended that there is a third important stakeholder group …


Remembering Paul B. Kannowski, Robert Seabloom Dec 2015

Remembering Paul B. Kannowski, Robert Seabloom

The Prairie Naturalist

I am saddened to report that Dr. Paul Kannowski passed away 3 September 2015, succumbing to cancer. He was 88. A native of Grand Forks, Paul attended the University of North Dakota for his B.S. and M.S. degrees, and the University of Michigan for his Ph.D. He joined the University of North Dakota Biology Department in 1957, retiring in 1990 after 33 years of service

Paul chaired UND’s Biology Department twice, totaling 13 years, considered to be a remarkable achievement by many of us who have been exposed to that task! His leadership was instrumental in the nearly exponential growth …


Notes: Woodpecker Forage Availability In Habi- Tat Disturbances Of The Black Hills, Brian E. Dickerson, Angie K. Ambourn, Mark A. Rumble, Kurt K. Allen, Chad P. Lehman Dec 2015

Notes: Woodpecker Forage Availability In Habi- Tat Disturbances Of The Black Hills, Brian E. Dickerson, Angie K. Ambourn, Mark A. Rumble, Kurt K. Allen, Chad P. Lehman

The Prairie Naturalist

Habitat disturbance events are critical to ecological systems in which some bird species have become specialized. The vegetation community, reduced competition, ability to avoid predators, nest-site characteristics, and forage opportunities within a disturbed ecosystem are all aspects that make it desirable for selection by particular species (Svärdson 1949, Cody 1981, Martin 1998). Specifically, avian species rely on the forest conditions created by fire, insects, and disease (Brawn et al. 2001, Hunter et al. 2001, Devictor et al. 2008). In the Black Hills National Forest (BHNF) of South Dakota,two major types of natural disturbances include wildfires and mountain pine beetle (Dendroctonus …


A Systematic Derivation Of Loop Specifications Using Patterns, Aditi Barua, Yoonsik Cheon Dec 2015

A Systematic Derivation Of Loop Specifications Using Patterns, Aditi Barua, Yoonsik Cheon

Departmental Technical Reports (CS)

Any non-trivial program contains loop control structures such as while, for and do statements. A formal correctness proof of code containing loop control structures is typically performed using an induction-based technique, and oftentimes the most challenging step of an inductive proof is formulating a correct induction hypothesis. An incorrectly-formulated induction hypothesis will surely lead to a failure of the proof. In this paper we propose a systematic approach for formulating and driving specifications of loop control structures for formal analysis and verification of programs. We explain our approach using while loops and a functional program verification technique in which a …


Interval Methods For Data Fitting Under Uncertainty: A Probabilistic Treatment, Vladik Kreinovich, Sergey P. Shary Dec 2015

Interval Methods For Data Fitting Under Uncertainty: A Probabilistic Treatment, Vladik Kreinovich, Sergey P. Shary

Departmental Technical Reports (CS)

How to estimate parameters from observations subject to errors and uncertainty? Very often, the measurement errors are random quantities that can be adequately described by the probability theory. When we know that the measurement errors are normally distributed with zero mean, then the (asymptotically optimal) Maximum Likelihood Method leads to the popular least squares estimates. In many situations, however, we do not know the shape of the error distribution, we only know that the measurement errors are located on a certain interval. Then the maximum entropy approach leads to a uniform distribution on this interval, and the Maximum Likelihood Method …


Fabrication, Characterization, And Application Of Carbon Nanoparticles For The Detection Of Heavy Metal Ions In Aqueous Media, Aaron Michael Simpson Dec 2015

Fabrication, Characterization, And Application Of Carbon Nanoparticles For The Detection Of Heavy Metal Ions In Aqueous Media, Aaron Michael Simpson

MSU Graduate Theses

This research set out to develop a method for producing Carbon nanoparticles (CNPs) from glycerol and use them to detect Cu2+, Hg2+, and Pb2+ ions in aqueous solution. Three synthesis methods were developed using the following mixtures: (1) glycerol and silica, (2) glycerol, silica, and H3PO4, and (3) glycerol with H3PO4. The structure of the particles was characterized using a variety of spectroscopic techniques. Size distributions were obtained from scanning electron microscopy images. The particles were spherical with average diameters of 66, 58, and 89 nm respectively and believed to consist of a carbon core with carboxylic acid and alcohol …


Aflatoxin Level In Selected Spices In Abu Dhabi Markets, Salma Ibrahim Al Hammadi Dec 2015

Aflatoxin Level In Selected Spices In Abu Dhabi Markets, Salma Ibrahim Al Hammadi

Theses

Aflatoxins (AF) are toxic secondary metabolites secreted by the fungi Aspergillus or Penicillium. Four aflatoxins (AFB1, AFB2, AFG1 and AFG2) are common in foods and feeds produced or stored under unfavorable conditions of humidity and temperature AFB1 is considered the most toxic.

Spices are significant ingredients in the UAE cuisine, used for the purpose of seasoning, coloring, and flavoring. In this research, 94 samples of spices (including pepper, chili, coriander, fennel seeds, paprika, turmeric, zataria, and mixed spices) purchased from different markets in the Emirate of Abu Dhabi, were analyzed for their contents of AF. Sample were analyzed using high-performance …


Constructions And Isomorphism Types Of Images, Jessica Luna Ramirez Dec 2015

Constructions And Isomorphism Types Of Images, Jessica Luna Ramirez

Electronic Theses, Projects, and Dissertations

In this thesis, we have presented our discovery of true finite homomorphic images of various permutation and monomial progenitors, such as 2*7: D14, 2*7 : (7 : 2), 2*6 : S3 x 2, 2*8: S4, 2*72: (32:(2S4)), and 11*2 :m D10. We have given delightful symmetric presentations and very nice permutation representations of these images which include, the Mathieu groups M11, M12, the 4-fold cover of the Mathieu group M22, 2 x …


River Restoration: Institutions, Boundaries, And Social Ecological Dynamics, Eileen Sylvan Johnson Dec 2015

River Restoration: Institutions, Boundaries, And Social Ecological Dynamics, Eileen Sylvan Johnson

Electronic Theses and Dissertations

This human dimensions research, consisting of three manuscripts, explores the social and ecological dimensions of river restoration through an examination of the restoration trajectories of the Androscoggin, an impaired system, and the Kennebec, a restored system. Manuscript one examines the influence of biophysical and community attributes and institutional rules on policy stakeholders goals and actions within the two watersheds. For manuscripts one and two, we conducted semi-structured interviews with key informants, assembled documents pertaining to restoration actions, and conducted participant observation at stakeholder meetings. We qualitatively analyzed transcripts and documents. Results suggest that policy stakeholders’ understandings of biophysical and community …


An Integrated Drought Index (Idi) Incorporating Physical And Social Aspects, Rebecca L. Lanier Dec 2015

An Integrated Drought Index (Idi) Incorporating Physical And Social Aspects, Rebecca L. Lanier

Master's Theses

The purpose of this research was to determine significant bio-physical (physical and environmental) and social variables that can be integrated into a drought index to predict areas susceptible to drought. Severe drought events are capable of causing millions of dollars in damage. The 1988 drought caused the United States approximately $40 billion in damage. Drought forecasting, modeling, and detection have, therefore, become imperative to understand the social, economic and environmental impacts of droughts, and also to explore how these impacts play a role in the occurrence of a drought. A number of drought indices widely used in the U.S. rely …


From Dye Sensitized Solar Cells To Organic Field Effect Transistors: A Computational Investigation Into The Structural And Electronic Properties Of Novel Phthalocyanines, Patrick J. Dwyer Dec 2015

From Dye Sensitized Solar Cells To Organic Field Effect Transistors: A Computational Investigation Into The Structural And Electronic Properties Of Novel Phthalocyanines, Patrick J. Dwyer

Seton Hall University Dissertations and Theses (ETDs)

Phthalocyanines (Pc) have gained intense research attention in many diverse application areas due to their highly tunable electronic and structural properties through modification of the molecular periphery and metal center. Throughout this work a series of novel perfluoro-isopropyl substituted MPc have been investigated through theoretical methods. First, the synthetic mechanisms of these Pcs will be explored to gain insight into the experimentally observed Pc product distribution. By examining the electronic structure and formation energies of the various Pc precursors, we explain the product distribution as well as propose the formation of additional Pcs, which were not currently believed to form. …


Rank Based Procedures For Ordered Alternative Models, Yuanyuan Shao Dec 2015

Rank Based Procedures For Ordered Alternative Models, Yuanyuan Shao

Dissertations

The ordered alternatives in a one-way layout with k ordered treatment levels are appropriate for many applications, especially in psychology and medicine. There is extensive literature in this area, and many parametric and nonparametric approaches have been introduced. Abelson-Tukey (AT) test is a frequently used parametric method. Its coefficients provide an ideal way of combining means for the purpose of detecting a monotonic relationship between the independent and dependent variables. The AT method, though, is not robust. Furthermore, our initial empirical studies show that it is not more powerful than the Jonckheere-Terpstra (JT) and the Hettmansperger- Norton (HN) nonparametric tests …


Period Change And Stellar Evolution Of Β Cephei Stars, Hilding R. Neilson, Richard Ignace Dec 2015

Period Change And Stellar Evolution Of Β Cephei Stars, Hilding R. Neilson, Richard Ignace

ETSU Faculty Works

The β Cephei stars represent an important class of massive star pulsators that probe the evolution of B-type stars and the transition from main sequence to hydrogen-shell burning evolution. By understanding β Cep stars, we gain insights into the detailed physics of massive star evolution, including rotational mixing, convective core overshooting, magnetic fields, and stellar winds, all of which play important roles. Similarly, modeling their pulsation provides additional information into their interior structures. Furthermore, measurements of the rate of change of pulsation period offer a direct measure of β Cephei stellar evolution. In this work, we compute state-of-the-art stellar evolution …


Umphlett Qci 2015, Natalie A. Umphlett Dec 2015

Umphlett Qci 2015, Natalie A. Umphlett

High Plains Regional Climate Center: Personnel Publications

Highlights for the Basin

Temperature and Precipitation Anomalies

Late Hard Freeze

Late Freezes Extended Growing Season

Warm Fall Delays Bird Migrations

Monitoring Water Resources Across the Basin

3-Month Precipitation and Temperature Outlooks


High Prevalence And Genetic Heterogeneity Of Rodent-Borne Bartonella Species On Heixiazi Island, China, Dong-Mei Li, Yong Hou, Xiu-Ping Song, Ying-Qun Fu, Gui-Chang Li, Ming Li, Marina E. Eremeeva, Hai-Xia Wu, Bo Pang, Yu-Juan Yue, Ying Huang, Liang Lu, Jun Wang, Qi-Yong Liu Dec 2015

High Prevalence And Genetic Heterogeneity Of Rodent-Borne Bartonella Species On Heixiazi Island, China, Dong-Mei Li, Yong Hou, Xiu-Ping Song, Ying-Qun Fu, Gui-Chang Li, Ming Li, Marina E. Eremeeva, Hai-Xia Wu, Bo Pang, Yu-Juan Yue, Ying Huang, Liang Lu, Jun Wang, Qi-Yong Liu

Environmental Health Sciences Faculty Publications

We performed genetic analysis of Bartonella isolates from rodent populations from Heixiazi Island in northeast China. Animals were captured at four sites representing grassland and brushwood habitats in 2011 and examined for the prevalence and genetic diversity of Bartonella species, their relationship to their hosts, and geographic distribution. A high prevalence (57.7%) and a high diversity (14 unique genotypes which belonged to 8 clades) of Bartonella spp. were detected from 71 rodents comprising 5 species and 4 genera from 3 rodent families. Forty-one Bartonella isolates were recovered and identified, including B. taylorii, B. japonica, B. coopersplainsensis, B. grahamii, B. washoensis …


Algorithm-Based Fault Tolerance For Two-Sided Dense Matrix Factorizations, Yulu Jia Dec 2015

Algorithm-Based Fault Tolerance For Two-Sided Dense Matrix Factorizations, Yulu Jia

Doctoral Dissertations

The mean time between failure (MTBF) of large supercomputers is decreasing, and future exascale computers are expected to have a MTBF of around 30 minutes. Therefore, it is urgent to prepare important algorithms for future machines with such a short MTBF. Eigenvalue problems (EVP) and singular value problems (SVP) are common in engineering and scientific research. Solving EVP and SVP numerically involves two-sided matrix factorizations: the Hessenberg reduction, the tridiagonal reduction, and the bidiagonal reduction. These three factorizations are computation intensive, and have long running times. They are prone to suffer from computer failures.

We designed algorithm-based fault tolerant (ABFT) …


Characteristics Of Kentucky’S Nursery And Greenhouse Industries [2015], Dewayne L. Ingram, Winston Dunwell, Alan Hodges Dec 2015

Characteristics Of Kentucky’S Nursery And Greenhouse Industries [2015], Dewayne L. Ingram, Winston Dunwell, Alan Hodges

Agriculture and Natural Resources Publications

The nursery and greenhouse industry in Kentucky is diverse and contributes significantly to the local and state economy. This industry represents the largest segment of Kentucky’s sales of horticultural products and is comprised almost completely of farm families. Nursery and greenhouse operations have historically been characterized as separate production systems and crops. However, today primary nurseries may also have greenhouses and/or produce herbaceous perennials and annuals to satisfy their customer base. On the other hand, many primary greenhouse firms that once grew mostly annuals and potted flowering crops have expanded their product line to include herbaceous perennials, often finished in …


Economic Impacts Of The Kentucky Green Industry [2015], Dewayne L. Ingram, Alan Hodges Dec 2015

Economic Impacts Of The Kentucky Green Industry [2015], Dewayne L. Ingram, Alan Hodges

Agriculture and Natural Resources Publications

The green industry, comprised of firms engaged in the production and use of landscape and floral crops and related supplies and equipment and the design, construction, and maintenance of landscapes, has a significant impact on Kentucky’s economy. Green-industry enterprise owners, managers, and employees should be aware of their economic impacts, and policy makers and other state leaders need to know the importance of this industry as potential laws, regulations and resource allocations are considered. This publication is intended to provide a brief summary of the 2013 economic impacts of the green industry in Kentucky.


Introduction To Wood Structure And Characteristics, Terry Conners Dec 2015

Introduction To Wood Structure And Characteristics, Terry Conners

Agriculture and Natural Resources Publications

Wood is identified using the features and tools that are appropriate to the size of the sample. Large timbers are identified by looking at the color, the appearance of the end and side grain, whether a saw cuts cleanly or leaves lots of splinters behind, whether the wood has straight or curly drying cracks, and so forth. The hardness and density provide valuable information as well. For smaller pieces of wood, it’s more practical to look directly at the wood cells with a 10X hand lens (also called a loupe). Different species have different characteristics and combinations of these features …


Distinguishing Softwoods From Hardwoods, Terry Conners Dec 2015

Distinguishing Softwoods From Hardwoods, Terry Conners

Agriculture and Natural Resources Publications

Softwood and hardwood trees are made up of different types of cells. With just a little magnification, it’s easy to see that softwood growth rings look different from hardwood growth rings. Additionally, growth rings don’t look the same for all of the trees, and the growth ring appearance is one of the things we will look at to identify wood.


Grain Patterns And Growth Rings, Terry Conners Dec 2015

Grain Patterns And Growth Rings, Terry Conners

Agriculture and Natural Resources Publications

The preceding article, "Identifying Wood–A Primer for Everyone, Part 3: Distinguishing Softwoods from Hardwoods" (FOR-125), described how to distinguish softwoods from hardwoods, and that’s the first step in identifying an unknown piece of wood. At this point, additional terminology is necessary to further distinguish between species, and I'll begin by talking about the different sides of a hypothetical piece of wood. Frequently you need to be able to observe wood cells from a particular perspective, and you will need to know where to look for different features on your sample. It’s also very helpful to develop a kind of “visual …


The First Separation Of Softwood Species, Terry Conners Dec 2015

The First Separation Of Softwood Species, Terry Conners

Agriculture and Natural Resources Publications

Just making the separation between softwoods and hardwoods doesn’t help much in identifying wood species; that would be sort of like identifying children by their hair color. Let’s look at the next level of wood features that you need to be able to recognize.


First Steps In Identifying Wood, Terry Conners Dec 2015

First Steps In Identifying Wood, Terry Conners

Agriculture and Natural Resources Publications

Wood samples need to be identified for all sorts of reasons, and they come in all shapes, sizes and conditions. I’ve received samples that were sound, samples that were waterlogged, samples that were rotted or otherwise degraded, painted samples, furniture samples, even samples containing wood preservatives. Most of the samples I receive have a North American origin, but I also receive pieces from art museums and antique dealers that can originate from just about anywhere. This sometimes means that identifying the sample by a common name alone doesn’t provide enough information.


Theoretical Investigation Of Interactions And Relaxation In Biological Macromolecules, Koki Yokoi Dec 2015

Theoretical Investigation Of Interactions And Relaxation In Biological Macromolecules, Koki Yokoi

Theses and Dissertations

One of the major challenges posed to our quantitative understanding of structure, dynamics, and function of biological macromolecules has been the high level of complexity of biological structures. In the present work, we studied interactions between G protein-coupled receptors (GPCRs), and also introduced a theoretical model of relaxation in complex systems, in order to help understand interactions and relaxation in biological macromolecules.

GPCRs are the largest and most diverse family of membrane receptors that play key roles in mediating signal transduction between outside and inside of a cell. Oligomerization of GPCRs and its possible role in function and signaling currently …


Positive Influence Dominating Set Generation In Social Networks, Akshaye Dhawan, Matthew Rink Dec 2015

Positive Influence Dominating Set Generation In Social Networks, Akshaye Dhawan, Matthew Rink

Mathematics and Computer Science Faculty Publications

Current algorithms in the Positive Influence Dominating Set (PIDS) problem domain are focused on a specific type of PIDS, the Total Positive Influence Dominating Set (TPIDS). We have developed an algorithm specifically targeted towards the non-total type of PIDS. In addition to our new algorithm, we adapted two existing TPIDS algorithms to generate PIDS. We ran simulations for all three algorithms, and our new algorithm consistently generates smaller PIDS than both existing algorithms, with our algorithm generating PIDS approximately 5% smaller than the better of the two existing algorithms.


Supporting Data For The Characterization Of Pna-Dna Four-Way Junctions, Douglas Van Iverson Ii, Crystal C. Serrano, Ann Marie Brahan, Arik Shams, Filbert Totsingan, Anthony J. Bell Jr. Dec 2015

Supporting Data For The Characterization Of Pna-Dna Four-Way Junctions, Douglas Van Iverson Ii, Crystal C. Serrano, Ann Marie Brahan, Arik Shams, Filbert Totsingan, Anthony J. Bell Jr.

Faculty Publications

Holliday or DNA four-way junctions (4WJs) are cruciform/bent structures composed of four DNA duplexes. 4WJs are key intermediates in homologous genetic recombination and double-strand break repair. To investigate 4WJs in vitro, junctions are assembled using four asymmetric DNA strands. The presence of four asymmetric strands about the junction branch point eliminates branch migration, and effectively immobilizes the resulting 4WJ. The purpose of these experiments is to show that immobile 4WJs composed of DNA and peptide nucleic acids (PNAs) can be distinguished from contaminating labile nucleic acid structures. These data compare the electrophoretic mobility of hybrid PNA–DNA junctions vs. …


Assessing The Physical Security Of Idfs With Psatool: A Case Study, Sulabh Bista Dec 2015

Assessing The Physical Security Of Idfs With Psatool: A Case Study, Sulabh Bista

Electronic Theses and Dissertations

PSATool is a checklist-based, web-based application for assessing the physical security of Intermediate Distribution Frameworks. IDFs, or wiring closets, are an integral if often neglected component of information security. Earlier work by Timbs (2013) identified 52 IDF-related security requirements based on federal and international standards for physical security. PSATool refines Timbs’ prototype application for IDF assessment, extending it with support for mobile-device-based data entry.

PSATool was used to assess 25 IDFs at a regional university, a college and a manufacturing corporation, with an average of 9 minutes per assessment. Network managers and assessors involved in the assessments characterized PSATool as …