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2005

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Articles 991 - 1020 of 5573

Full-Text Articles in Physical Sciences and Mathematics

A Comparison Of Diets And Water Agitation Methods For Larval Culture Of The Edible Sea Urchin, Tripneustes Ventricosus (Echinodermata: Echinoidea), Ray Wolcott, Charles G. Messing Sep 2005

A Comparison Of Diets And Water Agitation Methods For Larval Culture Of The Edible Sea Urchin, Tripneustes Ventricosus (Echinodermata: Echinoidea), Ray Wolcott, Charles G. Messing

Marine & Environmental Sciences Faculty Articles

Tripneustes ventricosus (Lamarck, 1816) has been harvested for human consumption in the Caribbean for centuries, where harvest rates occasionally exceed sustainability. Historically a backreef and grass-bed urchin, the species has recently been observed on the forereef where it appears to control macroalgal growth in the absence of Diadema antillarum (Philippi, 1845) (Woodley and Gayle, 1999). Large-scale culturing has the potential to produce T. ventricosus in sufficient numbers for remediation of degraded coral reefs, restocking of nearshore habitats, and development of an aquaculture industry for one or more Caribbean islands. We report the first successful culturing of T. ventricosus from fertilization …


A New Pathway For Communicating The 11-Year Solar Cycle Signal To The Qbo, Eugene C. Cordero, Terrence R. Nathan Sep 2005

A New Pathway For Communicating The 11-Year Solar Cycle Signal To The Qbo, Eugene C. Cordero, Terrence R. Nathan

Eugene C. Cordero

[1] The response of the equatorial quasi-biennial oscillation (QBO) to zonal-mean ozone perturbations consistent with the 11-year solar cycle is examined using a 2 1/2 dimensional model of the tropical stratosphere. Unique to this model are wave-ozone feedbacks, which provide a new, nonlinear pathway for communicating solar variability effects to the QBO. Model simulations show that for zonal-mean ozone perturbations representative of solar maximum (minimum), the diabatic heating due to the wave-ozone feedbacks is primarily responsible for driving a slightly stronger (weaker) QBO circulation and producing a slightly shorter (longer) QBO period. These results, which are explained via an analytical …


Refuge Update – September/October 2005, Volume 2, Number 5 Sep 2005

Refuge Update – September/October 2005, Volume 2, Number 5

RefugeUpdate (USFWS-NWRS)

Ravaged by Nature, page 3 Hurricanes Katrina and Rita left millions of dollars of damage in their wake.

Focus on…Comprehensive Conservation Planning, pages 10-14 What does it take to draft a first-rate CCP? How does a refuge reach out and communicate with partners and community?

Baby Switch in High Places, page 21 Refuge biologists in California successfully swap a fertile for an infertile egg and the condor parents are none the wiser.

Invasive Plant Mapping, page 9 Volunteers using state-of-the-arttechnology are helping to map and control invasive plants.


Charge-Exchange-Produced K -Shell X-Ray Emission From Ar¹⁶⁺ In A Tokamak Plasma With Neutral-Beam Injection, P. Beiersdorfer, M. Bitter, M. Marion, Ronald E. Olson Sep 2005

Charge-Exchange-Produced K -Shell X-Ray Emission From Ar¹⁶⁺ In A Tokamak Plasma With Neutral-Beam Injection, P. Beiersdorfer, M. Bitter, M. Marion, Ronald E. Olson

Physics Faculty Research & Creative Works

High-resolution spectroscopy of a hot tokamak plasma seeded with argon ions and interacting with an energetic, short-pulse neutral hydrogen beam was used to obtain a high-resolution K -shell x-ray spectrum formed solely by charge exchange. The observed K -shell emission of Ar16+ is dominated by the intercombination and forbidden lines, providing clear signatures of charge exchange. Results from an ab initio atomic cascade model provide excellent agreement, validating a semiclassical approach for calculating charge-exchange cross sections.


Simultaneous Elastic And Electromechanical Imaging By Scanning Probe Microscopy: Theory And Applications To Ferroelectric And Biological Materials, J. Shin, B. J. Rodriguez, Arthur P. Baddorf, T. Thundat, E. Karapetian, M. Kachanov, Alexei Gruverman, Sergei V. Kalinin Sep 2005

Simultaneous Elastic And Electromechanical Imaging By Scanning Probe Microscopy: Theory And Applications To Ferroelectric And Biological Materials, J. Shin, B. J. Rodriguez, Arthur P. Baddorf, T. Thundat, E. Karapetian, M. Kachanov, Alexei Gruverman, Sergei V. Kalinin

Alexei Gruverman Publications

An approach for combined imaging of elastic and electromechanical properties of materials, referred to as piezoacoustic scanning probe microscopy (PA-SPM), is presented. Applicability of this technique for elastic and electromechanical imaging with nanoscale resolution in such dissimilar materials as ferroelectrics and biological tissues is demonstrated. The PA-SPM signal formation is analyzed based on the theory of nanoelectromechanics of piezoelectric indentation and signal sensitivity to materials properties and imaging conditions. It is shown that simultaneous measurements of local indentation stiffness and indentation piezocoefficient provide the most complete description of the local electroelastic properties for transversally isotropic materials, thus making piezoacoustic SPM …


Using Incongruent Equilibrium Hydration Reactions To Model Latter-Stage Crystallization In Plutons: Examples From The Bell Island Tonalite, Alaska, J. S. Beard, P. C. Ragland, Maria Luisa Crawford Sep 2005

Using Incongruent Equilibrium Hydration Reactions To Model Latter-Stage Crystallization In Plutons: Examples From The Bell Island Tonalite, Alaska, J. S. Beard, P. C. Ragland, Maria Luisa Crawford

Geology Faculty Research and Scholarship

Models using hydration crystallization reactions (the reverse of dehydration melting reactions such as amph + qtz = px + melt) for the Bell Island pluton define incongruent equilibrium crystallization paths from hydrous + melt + pyroxene + Fe-Ti oxides + calcic andesine (30%-50% solid) to a solid tonalite consisting mostly of hornblende, lower temperature end of Bowen's discontinuous reaction series and apply it to natural samples. Hydration crystallization provides an alternative to crystal fractionation for explaining variations in pluton chemistry, especially the compositions of late plutonic melts. Another characteristic of hydration crystallization is that the reactions have the potential to …


Comparison Of Affymetrix Genechip Expression Measures, Rafael A. Irizarry, Zhijin Wu, Harris A. Jaffee Sep 2005

Comparison Of Affymetrix Genechip Expression Measures, Rafael A. Irizarry, Zhijin Wu, Harris A. Jaffee

Johns Hopkins University, Dept. of Biostatistics Working Papers

Affymetrix GeneChip expression array technology has become a standard tool in medical science and basic biology research. In this system, preprocessing occurs before one obtains expression level measurements. Because the number of competing preprocessing methods was large and growing, in the summer of 2003 we developed a benchmark to help users of the technology identify the best method for their application. In conjunction with the release of a Bioconductor R package (affycomp), a webtool was made available for developers of preprocessing methods to submit them to a benchmark for comparison. There have now been over 30 methods compared via the …


Hyperpycnal Discharge Of Fluvial Sediment To The Ocean: Impact Of Super‐Typhoon Herb (1996) On Taiwanese Rivers, John D. Milliman, Shuh-Ji Kao Sep 2005

Hyperpycnal Discharge Of Fluvial Sediment To The Ocean: Impact Of Super‐Typhoon Herb (1996) On Taiwanese Rivers, John D. Milliman, Shuh-Ji Kao

VIMS Articles

Hyperpycnal events (when suspended sediment concentrations exceed 40 g/L) occur in small‐ and medium‐sized rivers throughout the world but are particularly common in Taiwan; they are often related to landslides or debris flows initiated and transported by typhoon floods. Super‐Typhoon Herb, which swept across Taiwan on July 31–August 2, 1996, triggered floods and landslides throughout the southern part of the island. Sediment concentrations in at least seven rivers (Taan, Choshui, Pachang, Erhjen, Tsengwen, Kaoping, and Peinan) approached or exceeded 40 g/L. Calculated sediment discharged from nine rivers (these seven as well as the Wu and Houlung, neither of which apparently …


The Prairie Naturalist, Volume 37, Number 3, September 2005 Sep 2005

The Prairie Naturalist, Volume 37, Number 3, September 2005

The Prairie Naturalist

Landscape Compostiona and Greater Prairie Chicken Lek Attendance: Implications for Management by N. D. Niemuth

Helminthic Parasites in Ring-necked Pheasant from Southwestern Kansas by R. J. Robel, T. L. Walker, Jr., R. K. Ridley, K. E. Kemp, and R. D. Applegate

Seasonal Migration and Home Ranges of Female Elk in the Black Hills of South Dakota and Wyoming by L. Benkobi, M. A. Rumble, C. H. Stubblefield, R. S. Garno, and J. J. Millspaugh

Ring-necked Pheasant Survive with Broken Wings by R. D. Applegate and L. Scott

First Nebraska Nest Record for Henslow's Sparrow by D. H. Kim

RangeE Extension …


Analysis Of Per Capita Expenditures Of Suburbanizing Communities In Maine, New England Environmental Finance Center Sep 2005

Analysis Of Per Capita Expenditures Of Suburbanizing Communities In Maine, New England Environmental Finance Center

Economics and Finance

This study analyzes per capita expenditure trends among selected fast-growing Maine towns from 1970-2004. The ten communities studied are termed as “suburbanizing” towns. This term is used to describe towns that over the past 30-40 years have been in the process of transition from rural to suburban – in terms of their population and housing densities, their forms of government, and the services they provide, as well as other characteristics.1 Such towns are of particular interest because they have been absorbing a healthy percentage of the state’s population growth during this time period, often at the expense of Maine’s service …


Normal Hematologic And Biochemical Values For Prelaying Greater Sage Grouse (Centrocercus Urophasianus) And Their Influence On Chick Survival, Mike R. Dunbar, Michael A. Gregg, John A. Crawford, Mark R. Giordano, Susan J. Tornquist Sep 2005

Normal Hematologic And Biochemical Values For Prelaying Greater Sage Grouse (Centrocercus Urophasianus) And Their Influence On Chick Survival, Mike R. Dunbar, Michael A. Gregg, John A. Crawford, Mark R. Giordano, Susan J. Tornquist

United States Department of Agriculture Wildlife Services: Staff Publications

Declines in greater sage grouse (Centrocercus urophasianus) productivity and population numbers throughout their range demand a better understanding of how nutrition influences sage grouse populations. During March and April 1999–2001, blood samples were collected from 158 female (73 adult, 85 yearling), free-ranging, prelaying, greater sage grouse from an area in northwestern Nevada, USA, and southeastern Oregon, USA. These blood samples were evaluated to establish normal blood values for sage grouse and ascertain if certain blood parameters, as indices of nutrition, are useful for predicting if sage grouse hens would raise at least one chick to 1 August. Results of logistic …


Monomethyl Histone H3 Lysine 4 As An Epigenetic Mark For Silenced Euchromatin In Chlamydomonas, Karin V. Van Dijk, Katherine E. Marley, Byeong-Ryool Jeong, Jianping Xu, Jennifer Hesson, Ronald Cerny, Jakob H. Waterborg, Heriberto D. Cerutti Sep 2005

Monomethyl Histone H3 Lysine 4 As An Epigenetic Mark For Silenced Euchromatin In Chlamydomonas, Karin V. Van Dijk, Katherine E. Marley, Byeong-Ryool Jeong, Jianping Xu, Jennifer Hesson, Ronald Cerny, Jakob H. Waterborg, Heriberto D. Cerutti

Ronald Cerny Publications

Histone Lys methylation plays an important role in determining chromatin states and is mostly catalyzed by SET domain– containing proteins. The outcome, transcriptional repression or activation, depends on the methylated histone residue, the degree of methylation, and the chromatin context. Dimethylation or trimethylation of histone H3 Lys 4 (H3K4me2 or H3K4me3) has been correlated with transcriptionally competent/active genes. However, H3K4 methylation has also been implicated in gene silencing. This dualistic nature of the H3K4 methyl mark has thus far remained unresolved. In the green alga Chlamydomonas reinhardtii, Mut11p, related to a subunit of trithorax-like methyltransferase complexes, is required for transcriptional …


Ga-Facilitated Knn Classifier Optimization With Varying Similarity Measures, Michael R. Peterson, Travis E. Doom, Michael L. Raymer Sep 2005

Ga-Facilitated Knn Classifier Optimization With Varying Similarity Measures, Michael R. Peterson, Travis E. Doom, Michael L. Raymer

Kno.e.sis Publications

Genetic algorithms are powerful tools for k-nearest neighbors classifier optimization. While traditional knn classification techniques typically employ Euclidian distance to assess pattern similarity, other measures may also be utilized. Previous research demonstrates that GAs can improve predictive accuracy by searching for optimal feature weights and offsets for a cosine similarity-based knn classifier. GA-selected weights determine the classification relevance of each feature, while offsets provide alternative points of reference when assessing angular similarity. Such optimized classifiers perform competitively with other contemporary classification techniques. This paper explores the effectiveness of GA weight and offset optimization for knowledge discovery using knn classifiers with …


The Outcome Of Mta As A Root End Filling Material: A Long Term Evaluation, Christopher M. Sechrist Sep 2005

The Outcome Of Mta As A Root End Filling Material: A Long Term Evaluation, Christopher M. Sechrist

Loma Linda University Electronic Theses, Dissertations & Projects

Periradicular surgery is a viable option to save natural teeth when non-surgical treatment fails or when endodontic retreatment is not feasible or contraindicated. Laboratory and animal studies have demonstrated that MTA is biocompatible, provides an excellent seal against penetrating bacteria, and promotes hard tissue healing. The purpose of this study was to provide long term (>3 years) clinical evidence for its use as a root-end filling material in endodontics. The clinical records of 294 patients who had MTA used during endodontic treatment from 1996 to 2001 were reviewed. From these, 75 patients whose root end cavities had been filled …


Cooperative Reinforcement Learning Using An Expert-Measuring Weighted Strategy With Wolf, Kevin Cousin, Gilbert L. Peterson Sep 2005

Cooperative Reinforcement Learning Using An Expert-Measuring Weighted Strategy With Wolf, Kevin Cousin, Gilbert L. Peterson

Faculty Publications

Gradient descent learning algorithms have proven effective in solving mixed strategy games. The policy hill climbing (PHC) variants of WoLF (Win or Learn Fast) and PDWoLF (Policy Dynamics based WoLF) have both shown rapid convergence to equilibrium solutions by increasing the accuracy of their gradient parameters over standard Q-learning. Likewise, cooperative learning techniques using weighted strategy sharing (WSS) and expertness measurements improve agent performance when multiple agents are solving a common goal. By combining these cooperative techniques with fast gradient descent learning, an agent’s performance converges to a solution at an even faster rate. This statement is verified in a …


Von Neumann And Computers, Steve Humble Sep 2005

Von Neumann And Computers, Steve Humble

The Mathematics Enthusiast

The title of this paper should not be Von Neumann and computers, but Von Neumann and the Von Neumann machine. Von Neumann may be famous for many things but humility was not one of them. Yet no one had anything bad to say about 'good time' Johnny Von Neumann; he just was too likeable. He gave massive parties and loved women, fast cars, jokes, noise, Mexican food, fine wine, and, most of all, mathematics. 'Unbelievable', said one of Von Neumann's old friends, 'He knew how to have a good time. His parties were once if not twice a week at …


Instrumented Techniques And Reflective Thinking In Analytic Geometry, Nurit Zehavi, Giora Mann Sep 2005

Instrumented Techniques And Reflective Thinking In Analytic Geometry, Nurit Zehavi, Giora Mann

The Mathematics Enthusiast

In a previous study that explored epistemological perspectives on solving problems with Computer Algebra Systems (CAS) we concluded that awareness of the special ways that the software utilizes symbols in algebraic manipulations and in implicit plotting should be encouraged (Zehavi, 2004). Such awareness is required for, and encouraged by treating geometry analytically with a symbolic-graphical system. In this paper we compare a traditional solution of a problem in analytic geometry with CAS-based solutions to the same problem. The discussion will focus on the role of reflective thinking, namely selection of techniques, monitoring of the solution process, insight, and conceptualization, play …


A Comparison Of The Danish And The Virginia Secondary Teacher Education System: Their Values And Emphasis On Mathematics Content Knowledge, Bettina Dahl Sep 2005

A Comparison Of The Danish And The Virginia Secondary Teacher Education System: Their Values And Emphasis On Mathematics Content Knowledge, Bettina Dahl

The Mathematics Enthusiast

In this paper I will first examine an example of secondary mathematics teacher education in the USA, namely Virginia, then compare it with the secondary teacher education in Denmark. The purpose is both to investigate how much mathematics the students get in the respective systems and secondly to see what this type of teacher education communicates about the values emphasized in the various countries’ education systems. I spent more time on explaining the Danish education system than that of the USA and the single states since it is assumed that the reader is familiar with these systems. One cannot necessarily …


Problem Solving And Problem Posing In A Dynamic Geometry Environment, Constantinos Christou, Nicholas Mousoulides, Marios Pittalis, Demetra Pitta-Pantazi Sep 2005

Problem Solving And Problem Posing In A Dynamic Geometry Environment, Constantinos Christou, Nicholas Mousoulides, Marios Pittalis, Demetra Pitta-Pantazi

The Mathematics Enthusiast

In this study, we considered dynamic geometry software (DGS) as the tool that mediates students’ strategies in solving and posing problems. The purpose of the present study was twofold. First, to understand the way in which students can solve problems in the setting of a dynamic geometry environment, and second, to investigate how DGS provides opportunities for posing new problems. Two mathematical problems were presented to six pre-service teachers with prior experience in dynamic geometry. Each student participated in two interview sessions which were video recorded. The results of the study showed that DGS, as a mediation tool, encouraged students …


Call For Papers Sep 2005

Call For Papers

The Mathematics Enthusiast

No abstract provided.


Tme Statistics Sep 2005

Tme Statistics

The Mathematics Enthusiast

No abstract provided.


The Ultrasonic/Shear-Force Microscope: Integrating Ultrasonic Sensing Into A Near-Field Scanning Optical Microscope, Andres H. La Rosa, Xiquan Cui, J. Mccollum, Nan Li, Richard Nordstrom Sep 2005

The Ultrasonic/Shear-Force Microscope: Integrating Ultrasonic Sensing Into A Near-Field Scanning Optical Microscope, Andres H. La Rosa, Xiquan Cui, J. Mccollum, Nan Li, Richard Nordstrom

Physics Faculty Publications and Presentations

An ultrasonic transducer is incorporated into a near-field scanning optical microscope (NSOM) to augment its versatility to characterize the properties of layers adsorbed to a sample's surface. Working under typical NSOM operation conditions, the ultrasonic transducer--attached underneath the sample--demonstrates sufficient sensitivity to monitor the waves generated by the tapered NSOM probe that oscillates in the proximity of, and parallel to, the sample's top surface. This capability makes the newly integrated ultrasonic/shear-force microscope a valuable diagnostic tool in the study of sliding friction and surface phenomena in general. Here, it is used to concurrently and independently monitor the effects that probe-sample …


General Brochure, University Of North Dakota. Energy And Environmental Research Center Sep 2005

General Brochure, University Of North Dakota. Energy And Environmental Research Center

EERC Brochures and Fact Sheets

Brochure about the Energy & Environmental Research Center (EERC), including its philosophy, program areas, and Centers of Excellence.


Guide To Nebraska’S Wetlands And Their Conservation Needs: Second Edition, 2005, Ted Lagrange Sep 2005

Guide To Nebraska’S Wetlands And Their Conservation Needs: Second Edition, 2005, Ted Lagrange

Nebraska Game and Parks Commission: Publications

Wetlands — a source of great interest, and at times conflict. Wetlands represent different things to different people. At times they’re viewed as shallow, muddy nuisances while at other times they’re viewed as wonderful, varied and productive assets. This is because wetlands take on many roles as part of a complex and dynamic system. Understanding wetlands and wetland issues requires understanding the complex and varying roles that wetlands can play. To aid in this understanding, this guide defines wetlands, discusses their importance and dynamics, identifies threats and losses, describes conservation programs, and takes an in-depth look at Nebraska’s regional wetland …


Electron-Impact Ionization Of Hydrogen And Lithiumlike Systems, M A. Uddin, Abul Kalam Fazlul Haque, A K. Basak, Khondkar R. Karim, B C. Saha Sep 2005

Electron-Impact Ionization Of Hydrogen And Lithiumlike Systems, M A. Uddin, Abul Kalam Fazlul Haque, A K. Basak, Khondkar R. Karim, B C. Saha

Faculty publications – Physics

The electron impact single ionization cross sections on a number of targets with atomic number Z=1-92 in the H and Li isoelectronic sequences are calculated using a modified version of the recently propounded relativisitic improved binary-encounter dipole (MRIBED) model [M. A. Uddin , Phys. Rev. A 70, 032706 (2004); 71, 032715 (2005)]. The modified RQIBED (MRIBED) model along with a Z-dependent factor in it is found remarkably successful in the applications to H- and Li-like systems and also valid for the ionization of a filled s orbit including the He-like targets.


Laser And Led Effects On The Proliferation Rate Of Periodontal Ligament Fibroblasts, Allen J. Job Sep 2005

Laser And Led Effects On The Proliferation Rate Of Periodontal Ligament Fibroblasts, Allen J. Job

Loma Linda University Electronic Theses, Dissertations & Projects

PURPOSE: To compare the effectiveness of a Gallium Aluminum Arsenide (GaAlAs) diode laser and a light emitting diode (LED) on periodontal ligament fibroblast cell proliferative rates.

METHODS and MATERIALS: PDLF obtained from freshly extracted permanent teeth were cultured under standard conditions until a subconfluent monolayer was present. The next section took 5 days to complete. On day 1, the initial cell concentration of 700 uL/cm2 was plated on 96-well assay plates and placed in a CO2 incubator at 37° C for 24 hours. On day 2, cell counts were first verified using hemocytometry then were irradiated using an …


Meet The Authors Sep 2005

Meet The Authors

The Mathematics Enthusiast

No abstract provided.


Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 22, Number 1, September 2005, College Of Engineering And Computer Science, Wright State University Sep 2005

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 22, Number 1, September 2005, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

A ten page newsletter created by the Wright State University College of Engineering and Computer Science that addresses the current affairs of the college.


Improving Large-Scale Network Traffic Simulation With Multi-Resolution Models, Guanhua Yan Sep 2005

Improving Large-Scale Network Traffic Simulation With Multi-Resolution Models, Guanhua Yan

Dartmouth College Ph.D Dissertations

Simulating a large-scale network like the Internet is a challenging undertaking because of the sheer volume of its traffic. Packet-oriented representation provides high-fidelity details but is computationally expensive; fluid-oriented representation offers high simulation efficiency at the price of losing packet-level details. Multi-resolution modeling techniques exploit the advantages of both representations by integrating them in the same simulation framework. This dissertation presents solutions to the problems regarding the efficiency, accuracy, and scalability of the traffic simulation models in this framework. The ``ripple effect'' is a well-known problem inherent in event-driven fluid-oriented traffic simulation, causing explosion of fluid rate changes. Integrating multi-resolution …


Editorial: Globalization, History, Technology And Mathematics Education, Bharath Sriraman Sep 2005

Editorial: Globalization, History, Technology And Mathematics Education, Bharath Sriraman

The Mathematics Enthusiast

No abstract provided.