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2007

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Articles 4141 - 4170 of 6758

Full-Text Articles in Physical Sciences and Mathematics

Oxidative Dna Damage In Mild Cognitive Impairment And Late-Stage Alzheimer's Disease, Mark A. Lovell, William R. Markesbery Jan 2007

Oxidative Dna Damage In Mild Cognitive Impairment And Late-Stage Alzheimer's Disease, Mark A. Lovell, William R. Markesbery

Chemistry Faculty Publications

Increasing evidence supports a role for oxidative DNA damage in aging and several neurodegenerative diseases including Alzheimer's disease (AD). Attack of DNA by reactive oxygen species (ROS), particularly hydroxyl radicals, can lead to strand breaks, DNA–DNA and DNA–protein cross-linking, and formation of at least 20 modified bases adducts. In addition, α,β-unsaturated aldehydic by-products of lipid peroxidation including 4-hydroxynonenal and acrolein can interact with DNA bases leading to the formation of bulky exocyclic adducts. Modification of DNA bases by direct interaction with ROS or aldehydes can lead to mutations and altered protein synthesis. Several studies of DNA base adducts in late-stage …


Overcoming Ideology: Why It Is Necessary To Create A Culture In Which The Ethical Review Of Protocols Can Flourish, Bernard E. Rollin Jan 2007

Overcoming Ideology: Why It Is Necessary To Create A Culture In Which The Ethical Review Of Protocols Can Flourish, Bernard E. Rollin

Experimentation Collection

My objective in this commentary is to describe and discuss a major threat to the continued thriving of science in our society, which is all the more insidious because it is largely unrecognized by those in the scientific community who are in a position to rectify the problem. Astute people in that community are well aware of many threats to science that include but are not limited to the following: appalling public scientific illiteracy; the unfortunate resurgence of “magic thinking”—reflected in turn in the reappearance of Creationism, which is hostile to evolution—and the billions of dollars spent on evidentially baseless …


The Convolution On Time Scales, Gusein Sh. Guseinov, Martin Bohner Jan 2007

The Convolution On Time Scales, Gusein Sh. Guseinov, Martin Bohner

Mathematics and Statistics Faculty Research & Creative Works

The main theme in this paper is an initial value problem containing a dynamic version of the transport equation. via this problem, the delay (or shift) of a function defined on a time scale is introduced, and the delay in turn is used to introduce the convolution of two functions defined on the time scale. In this paper, we give some elementary properties of the delay and of the convolution and we also prove the convolution theorem. Our investigation contains a study of the initial value problem under consideration as well as some results about power series on time scales. …


Trench's Perturbation Theorem For Dynamic Equations, Stevo Stevic, Martin Bohner Jan 2007

Trench's Perturbation Theorem For Dynamic Equations, Stevo Stevic, Martin Bohner

Mathematics and Statistics Faculty Research & Creative Works

We consider a nonoscillatory second-order linear dynamic equation on a time scale together with a linear perturbation of this equation and give conditions on the perturbation that guarantee that the perturbed equation is also nonoscillatory and has solutions that behave asymptotically like a recessive and dominant solutions of the unperturbed equation. As the theory of time scales unifies continuous and discrete analysis, our results contain as special cases results for corresponding differential and difference equations by William F. Trench.


Differentiability With Respect To Parameters Of Weak Solutions Of Linear Parabolic Equations, John R. Singler Jan 2007

Differentiability With Respect To Parameters Of Weak Solutions Of Linear Parabolic Equations, John R. Singler

Mathematics and Statistics Faculty Research & Creative Works

We consider the differentiability of weak solutions of linear parabolic equations with respect to parameters and initial data. under natural assumptions, it is shown that solutions possess as much differentiability with respect to the data as do the terms appearing in the equation. The derivatives are shown to satisfy the appropriate sensitivity equations. The theoretical results are illustrated with an example.


Oscillation And Nonoscillation Of Forced Second Order Dynamic Equations, Christopher C. Tisdell, Martin Bohner Jan 2007

Oscillation And Nonoscillation Of Forced Second Order Dynamic Equations, Christopher C. Tisdell, Martin Bohner

Mathematics and Statistics Faculty Research & Creative Works

Oscillation and nonoscillation properties of second order Sturm-Liouville dynamic equations on time scales — for example, second order self-adjoint differential equations and second order Sturm-Liouville difference equations — have attracted much interest. Here we consider a given homogeneous equation and a corresponding equation with forcing term. We give new conditions implying that the latter equation inherits the oscillatory behavior of the homogeneous equation. We also give new conditions that introduce oscillation of the inhomogeneous equation while the homogeneous equation is nonoscillatory. Finally, we explain a gap in a result given in the literature for the continuous and the discrete case. …


Oscillation Criteria For A Certain Class Of Second Order Emden-Fowler Dynamic Equations, Elvan Akin, S. H. Saker, Martin Bohner Jan 2007

Oscillation Criteria For A Certain Class Of Second Order Emden-Fowler Dynamic Equations, Elvan Akin, S. H. Saker, Martin Bohner

Mathematics and Statistics Faculty Research & Creative Works

By means of Riccati transformation techniques we establish some oscillation criteria for the second order Emden-Fowler dynamic equation on a time scale. Such equations contain the classical Emden-Fowler equation as well as their discrete counterparts. The classical oscillation results of Atkinson (in the superlinear case) and Belohorec (in the sublinear case) are extended in this paper to Emden-Fowler dynamic equations on any time scale.


The Dynamics And Interaction Of Quantized Vortices In The Ginzburg-Landau-Schrödinger Equation, Yanzhi Zhang, Weizhu Bao, Qiang Du Jan 2007

The Dynamics And Interaction Of Quantized Vortices In The Ginzburg-Landau-Schrödinger Equation, Yanzhi Zhang, Weizhu Bao, Qiang Du

Mathematics and Statistics Faculty Research & Creative Works

The dynamic laws of quantized vortex interactions in the Ginzburg-Landau-Schrödinger equation (GLSE) are analytically and numerically studied. A review of the reduced dynamic laws governing the motion of vortex centers in the GLSE is provided. The reduced dynamic laws are solved analytically for some special initial data. By directly simulating the GLSE with an efficient and accurate numerical method proposed recently in [Y. Zhang, W. Bao, and Q. Du, Numerical simulation of vortex dynamics in Ginzburg-Landau-Schrödinger equation, European J. Appl. Math., to appear], we can qualitatively and quantitatively compare quantized vortex interaction patterns of the GLSE with those from the …


On A Sub-Supersolution Method For The Prescribed Mean Curvature Problem, Vy Khoi Le Jan 2007

On A Sub-Supersolution Method For The Prescribed Mean Curvature Problem, Vy Khoi Le

Mathematics and Statistics Faculty Research & Creative Works

The paper is about a sub-supersolution method for the prescribed mean curvature problem. We formulate the problem as a variational inequality and propose appropriate concepts of sub- and supersolutions for such inequality. Existence and enclosure results for solutions and extremal solutions between sub- and supersolutions are established.


Creating And Presenting A Poster At The Undergraduate Student Symposium, Beatrix Aukszi, Christopher A. Blanar, Weylin Sternglanz Jan 2007

Creating And Presenting A Poster At The Undergraduate Student Symposium, Beatrix Aukszi, Christopher A. Blanar, Weylin Sternglanz

Chemistry and Physics Faculty Proceedings, Presentations, Speeches, Lectures

No abstract provided.


Post-Release Survival Of Sailfish (Istiophorus Platypterus) Captured On Commercial Pelagic Longline Gear In The Southern Gulf Of Mexico, David W. Kerstetter, John E. Graves Jan 2007

Post-Release Survival Of Sailfish (Istiophorus Platypterus) Captured On Commercial Pelagic Longline Gear In The Southern Gulf Of Mexico, David W. Kerstetter, John E. Graves

Marine & Environmental Sciences Faculty Reports

To estimate post-release survival of sailfish caught incidentally to regular commercial pelagic longline fishing operations in the southern Gulf of Mexico targeting mixed swordfish and tunas, ten pop-up satellite archival tags were deployed for ten days on incidentally captured animals. All ten tags transmitted following the full deployment period, transmitting 25-82% of the archived data. Repeated, short-duration movements at depth and horizontal displacement data from were consistent with survival of those nine of the ten animals for the ten-day deployment period. The results of this study indicate that sailfish can survive the trauma resulting from interaction with pelagic longline gear …


Preliminary Results Of Circle And J-Style Hook Comparisons In The Brazilian Pelagic Longline Fishery, David W. Kerstetter, J. C. Pacheco, Fabio H.V. Hazin, P. E. Travassos, John E. Graves Jan 2007

Preliminary Results Of Circle And J-Style Hook Comparisons In The Brazilian Pelagic Longline Fishery, David W. Kerstetter, J. C. Pacheco, Fabio H.V. Hazin, P. E. Travassos, John E. Graves

Marine & Environmental Sciences Faculty Reports

Preliminary studies in western North Atlantic pelagic longline fisheries indicate that a change in terminal gear from J-style hooks to circle hooks may reduce bycatch mortality. However, such studies have not examined the impact of this change in the equatorial fishery. Catch composition, catch rates, hooking location, and condition at haulback were monitored during 26 sets in the commercial longline fishery operating in the western equatorial South Atlantic where circle (size 18/0, non-offset) and J-style (size 9/0 and 10/0, 10° offset) hooks were deployed in an alternating fashion. Catch rates for yellowfin tuna, swordfish, and a composite “all fishes” category …


Joint United States-Brazil Billfish Research In The Western South Atlantic, David W. Kerstetter, Fabio H.V. Hazin, J. C. Pacheco, John E. Graves Jan 2007

Joint United States-Brazil Billfish Research In The Western South Atlantic, David W. Kerstetter, Fabio H.V. Hazin, J. C. Pacheco, John E. Graves

Marine & Environmental Sciences Faculty Reports

A joint research project between Brazilian and U.S. scientists was initiated in 2004 to investigate the interaction of istiophorid billfishes with pelagic longline fisheries in the western equatorial South Atlantic Ocean. This project incorporates two general themes (1) an investigation into several aspects of pelagic longline operations by comparing catch results between circle and “J” style hooks, time-of-capture with hook time recorders, and by direct monitoring of pelagic longline gear behavior, and (2) an additional evaluation of billfish trophic ecology using a combination of satellite tag technology and traditional analyses (e.g., gut contents and ageing). Data obtained from this research …


On The Complete Join Of Permutative Combinatorial Rees–Sushkevich Varieties, Edmond W. H. Lee Jan 2007

On The Complete Join Of Permutative Combinatorial Rees–Sushkevich Varieties, Edmond W. H. Lee

Mathematics Faculty Articles

A semigroup variety is a Rees–Sushkevich variety if it is contained in a periodic variety generated by 0-simple semigroups. The collection of all permutative combinatorial Rees–Sushkevich varieties constitutes an incomplete lattice that does not contain the complete join J of all its varieties. The objective of this article is to investigate the subvarieties of J. It is shown that J is locally finite, non-finitely generated, and contains only finitely based subvarieties. The subvarieties of J are precisely the combinatorial Rees–Sushkevich varieties that do not contain a certain semigroup of order four.


Winter 2007, Nsu Oceanographic Center Jan 2007

Winter 2007, Nsu Oceanographic Center

Currents

No abstract provided.


Triflic Acid Controlled Successive Annelation Of Aromatic Sulfonamides: An Efficient One-Pot Synthesis Of N-Sulfonyl Pyrroles, Indoles And Carbazoles, Abid Shaikh, Liliana Teixeira, Béla Török Jan 2007

Triflic Acid Controlled Successive Annelation Of Aromatic Sulfonamides: An Efficient One-Pot Synthesis Of N-Sulfonyl Pyrroles, Indoles And Carbazoles, Abid Shaikh, Liliana Teixeira, Béla Török

Abid Shaikh

A novel one-pot synthesis of N-substituted heterocycles via successive cyclization/annelation starting from primary sulfonamides is described. This process directly leads to N-sulfonyl pyrroles, indoles and carbazoles. The selection of an appropriate reactant/triflic acid ratio successfully controls the formation of the desired product.


Protein Arginine Methyltransferase 1: Positively Charged Residues In Substrate Peptides Distal To The Site Of Methylation Are Important For Substrate Binding And Catalysis, Tanesha C. Osborne, Obiamaka Obianyo, Xing Zhang, Xiadong Cheng, Paul R. Thompson Jan 2007

Protein Arginine Methyltransferase 1: Positively Charged Residues In Substrate Peptides Distal To The Site Of Methylation Are Important For Substrate Binding And Catalysis, Tanesha C. Osborne, Obiamaka Obianyo, Xing Zhang, Xiadong Cheng, Paul R. Thompson

Tanesha C. Osborne

Protein arginine methyltransferases (PRMTs) are a group of eukaryotic enzymes that catalyze the methylation of Arg residues in a variety of proteins (e.g., histones H3 and H4), and their activities influence a wide range of cellular processes, including cell growth, RNA splicing, differentiation, and transcriptional regulation. Dysregulation of these enzymes has been linked to heart disease and cancer, suggesting this enzyme family as a novel therapeutic target. To aid the development of PRMT inhibitors, we characterized the substrate specificity of both the rat and human PRMT1 orthologues using histone based peptide substrates. N- and C-terminal truncations to identify a minimal …


Using Gold Nanorods To Probe Cell-Induced Collagen Deformation, John W. Stone, Patrick N. Sisco, Edie C. Goldsmith, Sarah C. Baxter, Catherine J. Murphy Jan 2007

Using Gold Nanorods To Probe Cell-Induced Collagen Deformation, John W. Stone, Patrick N. Sisco, Edie C. Goldsmith, Sarah C. Baxter, Catherine J. Murphy

John W. Stone

In biological tissue, complex mechanisms of cellular response are closely linked to the mechanical environment that cells experience. The key to understanding these mechanisms may lie in measurement of local mechanical fields near living cells and between cells. We have developed a novel optical measurement technique which combines the light elastically scattered from gold nanorods with digital image analysis to track local deformations that occur in vitro between cells, in real time, under darkfield optical microscopy. We find that measurable tension and compression exist in the intercellular matrix at the length scale of micrometers, as the cells assess, adapt, and …


Spatial Ecology Of The Coachwhip, Masticophis Flagellum (Squamata: Colubridae), In Eastern Texas, Richard W. Johnson, Robert R. Fleet, Michael B. Keck, D. Craig Rudolph Jan 2007

Spatial Ecology Of The Coachwhip, Masticophis Flagellum (Squamata: Colubridae), In Eastern Texas, Richard W. Johnson, Robert R. Fleet, Michael B. Keck, D. Craig Rudolph

Faculty Publications

We radio-tracked nine Masticophis flagellum (Coachwhips) to determine home range, habitat use, and movements in eastern Texas from April to October 2000. Home ranges of Coachwhips contained more oak savanna macrohabitat than early-successional pine plantation or forested seep, based on the availability of these three macrohabitats in the study area. Likewise, within their individual home ranges, Coachwhips used oak savanna more than the other two macrohabitats, based on availability. An analysis of microhabitat use revealed that, relative to random sites within their home range, Coachwhips were found at sites with fewer pine trees and more herbaceous vegetation taller than 30 …


Symbolic Path Sensitization Analysis And Applications, Jian Kang, Sharad C. Seth, Shashank K. Mehta Jan 2007

Symbolic Path Sensitization Analysis And Applications, Jian Kang, Sharad C. Seth, Shashank K. Mehta

CSE Conference and Workshop Papers

A new symbolic approach models the sensitization paths to selected primary output(s) as Boolean equations, with satisfying solutions representing the set of all sources of single and multiple sensitizations in the circuit. The paper discusses two applications of this idea: model-free fault diagnosis and input sensitization analysis.


A Content Based Pattern Analysis System For A Biological Specimen Collection, Joyita Mallik, Ashok K. Samal, Scott L. Gardner Jan 2007

A Content Based Pattern Analysis System For A Biological Specimen Collection, Joyita Mallik, Ashok K. Samal, Scott L. Gardner

CSE Conference and Workshop Papers

Over the years many research collections of biological specimen have been developed for research in biological sciences. Number of specimens in some of these collections can be as high as several millions. There is a move to convert these physical specimens into digital images. This research is motivated by the need to develop techniques to mine useful information from these large collections of specimen images. Specific focus of this research is on the collection of parasites in the Harold W. Manter Laboratory (HWML) Parasite Collection, one of the top four parasite collections in the world. These parasites closely resemble in …


A Two-Phase Approach For Dynamic Lightpath Scheduling In Wdm Optical Networks, Lu Shen, Xi Yang, Ajay Todimala, Byrav Ramamurthy Jan 2007

A Two-Phase Approach For Dynamic Lightpath Scheduling In Wdm Optical Networks, Lu Shen, Xi Yang, Ajay Todimala, Byrav Ramamurthy

CSE Conference and Workshop Papers

Lightpath scheduling is an important capability in next-generation wavelength-division multiplexing (WDM) optical networks to reserve resources in advance for a specified time period while provisioning end-to-end lightpaths. In a dynamic environment, the end user requests for dynamic scheduled lightpath demands (D-SLDs) need to be serviced without the knowledge of future requests. Even though the starting time of the request may be hours or days from the current time, the end-user however expects a quick response as to whether the request could be satisfied. We propose a two-phase approach to dynamically schedule and provision D-SLDs. In the first phase, termed the …


Bandit-Based Algorithms For Budgeted Learning, Kun Deng, Chris Bourke, Stephen Scott, Julie Sunderman, Yaling Zheng Jan 2007

Bandit-Based Algorithms For Budgeted Learning, Kun Deng, Chris Bourke, Stephen Scott, Julie Sunderman, Yaling Zheng

CSE Conference and Workshop Papers

We explore the problem of budgeted machine learning, in which the learning algorithm has free access to the training examples’ labels but has to pay for each attribute that is specified. This learning model is appropriate in many areas, including medical applications. We present new algorithms for choosing which attributes to purchase of which examples in the budgeted learning model based on algorithms for the multi-armed bandit problem. All of our approaches outperformed the current state of the art. Furthermore, we present a new means for selecting an example to purchase after the attribute is selected, instead of selecting an …


Singlet Oxygen Generation Using New Fluorene-Based Photosensitizers Under One- And Two-Photon Excitation, Stephen James Andrasik Jan 2007

Singlet Oxygen Generation Using New Fluorene-Based Photosensitizers Under One- And Two-Photon Excitation, Stephen James Andrasik

Electronic Theses and Dissertations

Molecular oxygen in its lowest electronically excited state plays an important roll in the field of chemistry. This excited state is often referred to as singlet oxygen and can be generated in a photosensitized process under one- or two-photon excitation of a photosensitizer. It is particularly useful in the field of photodynamic cancer therapy (PDT) where singlet oxygen formation can be used to destroy cancerous tumors. The use of two-photon activated photosensitizers possesses great potential in the field of PDT since near-IR light is used to activate the sensitizer, resulting in deeper penetration of light into biological tissue, less photobleaching …


The Communicator, Volume [3], Issue [1], February 2007 Jan 2007

The Communicator, Volume [3], Issue [1], February 2007

The Communicator: News from the Nebraska Cooperative Fish and Wildlife Research Unit

Teaching and Training

New Faces (Chris Kelly; Justin Williams; Christopher Lewis; Dustin Martin)

Congratulations! (Donald Wardwell; Christopher Lewis; Aaron Lotz)

The Changing Faces of USGS

Current Research

Amphibian Monitoring Techniques (in Relation

to Wetland Qualities and the Surrounding

Landscape – Rainwater Basin Region)

Cross-Scale Structure in Ecosystems

An Adaptive Management Approach for Selecting

Habitat Improvement Targets in the Shortgrass

Prairie Ecosystem

Diversity and Ecological Functions

Impact of White Perch on Walleye; and

Predators of White Perch at Branched Oak and

Pawnee Reservoirs

Evaluation of Landowner Incentives Program

(LIP) for Species at Risk

Monitoring, Mapping and Risk Assessment for

Non-Indigenous Invasive …


Droughtscape- Winter 2007, Kelly Smith Jan 2007

Droughtscape- Winter 2007, Kelly Smith

Droughtscape, Quarterly Newsletter of NDMC, 2007-

Subscribe Now!

Policy Update: NIDIS is Law. What’s Next?

What Would You Like to See?

TX, OK, Plains, Southwest Hardest Hit in 2006

Climatologically Speaking, How Bad Was It?

State Spotlight: Arizona

Drought Decision-Support Tools Evolving


Review Of Skin: A Natural History By Nina G. Jablonski, Patrick Huff Jan 2007

Review Of Skin: A Natural History By Nina G. Jablonski, Patrick Huff

Ecological and Environmental Anthropology (University of Georgia)

In recent years, there seems to have been a wave of new books focused on mundane items of daily life. A list of the subjects of these books reads like a catalogue of commodities: coal, salt, cod, tobacco, coffee, cotton, not to mention various works dealing with commodities of the shadow economy such as cocaine, cannabis and heroin. These books seem to comprise a growing genre of popular non-fiction that might be called commodity biographies wherein the major narrative focus is on explicating the histories and everyday uses and abuses of perennially popular and ubiquitous items. Nina G. Jablonski’s Skin: …


Review Of The Organ Pipe Cactus By David Yetman, Geoff Kelley Jan 2007

Review Of The Organ Pipe Cactus By David Yetman, Geoff Kelley

Ecological and Environmental Anthropology (University of Georgia)

The Organ Pipe Cactus combines historical, interview, and field observation data to plea for greater awareness, appreciation, and conservation of the organ pipe cactus (Stenocereus thurberi) – pitaya as it is commonly known in the Sonoran Desert, Mexico. This short book (70 pages including excellent illustrations, glossary, references, and index) seeks to emphasize how (mostly impoverished) human communities have utilized and maintained the plant for centuries.
Yetman’s coverage of pitaya ecology is thorough and recognizes the roles humans have played in the plant’s distribution. Adaptations from cellular to landscape levels are explained with great clarity. Micro and macro …


Ipm And Iwdm: Is There A Difference?, Michael J. Bodenchuck Jan 2007

Ipm And Iwdm: Is There A Difference?, Michael J. Bodenchuck

Human–Wildlife Interactions

Integrated pest management (IPM) has been the model for pest management for more than half a century. IPM has been defined as “the process of integrating and applying practical methods of prevention and control to keep pest situations from reaching damaging levels while minimizing potentially harmful effects of pest control measures on humans, nontarget species and the environment” (USDA 1994). The IPM model taught in invertebrate pest management classes includes the concept of an economic threshold (a level at which the benefits of control exceed the costs of the damage plus the costs of control). The methods which are “integrated” …


Intrafield Patterns Of Wildlife Damage To Corn And Soybeans In Northern Indiana, Travis L. Devault, James C. Beasley, Lee A. Humberg, Brian J. Macgowan, Mónica I. Retamosa, Ollin E. Rhodes Jr. Jan 2007

Intrafield Patterns Of Wildlife Damage To Corn And Soybeans In Northern Indiana, Travis L. Devault, James C. Beasley, Lee A. Humberg, Brian J. Macgowan, Mónica I. Retamosa, Ollin E. Rhodes Jr.

Human–Wildlife Interactions

Management programs aimed at reducing wildlife damage to row crops rely on information concerning the spatial nature of wildlife damage at local and landscape scales. In this study we explored spatial patterns of wildlife damage within individual corn and soybean fields by describing relationships between specific locations where wildlife damage was recorded and distances from such locations to various habitat types that presumably influenced animal abundance and movements in our study area. Using stratified random sampling, we conducted depredation surveys of 100 corn fi elds and 60 soybean fields from May through October both in 2003 and 2004 and recorded …