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2010

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Articles 481 - 510 of 6945

Full-Text Articles in Physical Sciences and Mathematics

Large Group Delay In A Microwave Metamaterial Analog Of Electromagnetically Induced Transparency, Lei Zhang, Philippe Tassin, Thomas Koschny, Cihan Kurter, Steven M. Anlage, C. M. Soukoulis Dec 2010

Large Group Delay In A Microwave Metamaterial Analog Of Electromagnetically Induced Transparency, Lei Zhang, Philippe Tassin, Thomas Koschny, Cihan Kurter, Steven M. Anlage, C. M. Soukoulis

Physics Faculty Research & Creative Works

We report on our experimental work concerning a planar metamaterial exhibiting classical electromagnetically induced transparency (EIT). Using a structure with two mirrored split-ring resonators as the dark element and a cut wire as the radiative element, we demonstrate that an EIT-like resonance can be achieved without breaking the symmetry of the structure. The mirror symmetry of the metamaterial's structural element results in a selection rule inhibiting magnetic dipole radiation for the dark element, and the increased quality factor leads to low absorption (<10%) and large group index (of the order of 30).


Reaction Dynamics In Double Ionization Of Helium By Electron Impact, Marcelo F. Ciappina, Michael Schulz, Tom Kirchner Dec 2010

Reaction Dynamics In Double Ionization Of Helium By Electron Impact, Marcelo F. Ciappina, Michael Schulz, Tom Kirchner

Physics Faculty Research & Creative Works

We present theoretical fully differential cross sections (FDCS) for double ionization of helium by 500 eV and 2 keV electron impact. Contributions from various reaction mechanisms to the FDCS were calculated separately and compared to experimental data. Our theoretical methods are based on the first Born approximation. Higher-order effects are incorporated using the Monte Carlo event generator technique. Earlier, we successfully applied this approach to double ionization by ion impact, and in the work reported here it is extended to electron impact. We demonstrate that at 500 eV impact energy, double ionization is dominated by higher-order mechanisms. Even at 2 …


Xpath-Based Template Language For Describing The Placement Of Metadata Within A Document, Vijay Kumar Musham Dec 2010

Xpath-Based Template Language For Describing The Placement Of Metadata Within A Document, Vijay Kumar Musham

Computer Science Theses & Dissertations

In the recent years, there has been a tremendous growth in Internet and online resources that had previously been restricted to paper archives. OCR (Optical Character Recognition) tools can be used for digitalizing an existing corpus and making it available online. A number of federal agencies, universities, laboratories, and companies are placing their collections online and making them searchable via metadata fields such as author, title, and publishing organization. Manually creating metadata for a large collection is an extremely time-consuming task, and is difficult to automate, particularly for collections consisting of documents with diverse layout and structure. The Extract project …


Chosen-Ciphertext Secure Bidirectional Proxy Re-Encryption Schemes Without Pairings, Jian Weng, Huijie, Robert Deng, Shengli Liu, Kefei Chen Dec 2010

Chosen-Ciphertext Secure Bidirectional Proxy Re-Encryption Schemes Without Pairings, Jian Weng, Huijie, Robert Deng, Shengli Liu, Kefei Chen

Research Collection School Of Computing and Information Systems

Proxy re-encryption realizes delegation of decryption rights, enabling a proxy holding a re-encryption key to convert a ciphertext originally intended for Alice into an encryption of the same message for Bob. Proxy re-encryption is a very useful primitive, having many applications in distributed file systems, outsourced filtering of encrypted spam, access control over network storage, and so on. Lately, Weng et al. proposed the first unidirectional proxy re-encryption scheme without using bilinear pairs. However, Weng et al.'s construction does not possess collusion resilience, in the sense that a coalition of the proxy and the delegatee can recover the delegator's private …


The Determinants Of Colorectal Cancer Survival Disparities In Nevada, Lucas N. Wassira Dec 2010

The Determinants Of Colorectal Cancer Survival Disparities In Nevada, Lucas N. Wassira

UNLV Theses, Dissertations, Professional Papers, and Capstones

Different population groups across Nevada and throughout the United States suffer disproportionately from colorectal cancer and its after-effects. Overcoming cancer health disparities is important for lessening the burden of cancer. There has been an overall decline in the incidence of and mortality from colorectal cancer (CRC). This is likely due, in part, to the increasing use of screening procedures such as Fecal Occult Blood Test (FOBT) and/or endoscopy, which can reduce the risk of CRC mortality by fifty percent. Nevertheless, screening procedures are routinely used by only fifty percent of Americans aged fifty years and older. Despite overall mortality decreasing …


Removal Of Arsenic And Strontium From Aqueous Solution Using Ironoxide Coated Zeolitized Tuff, Nataliya V. Kasimtseva Dec 2010

Removal Of Arsenic And Strontium From Aqueous Solution Using Ironoxide Coated Zeolitized Tuff, Nataliya V. Kasimtseva

UNLV Theses, Dissertations, Professional Papers, and Capstones

As world population grows so does the demand for safe drinking water. Meanwhile water resources become increasingly scarce and quality of natural water decreases due to a combination of natural and anthropogenic factors. Industry and agriculture have become a premiere source of hazardous constituents, along with natural processes such as rock weathering and volcanic eruptions. Our ability to remove hazardous constituents from water depends on chosen technology and nature of contaminant. Sorption and ion-exchange have been widely applied for water purification. Natural zeolites have been widely applied in water and waste water treatment as ion-exchangers for removal of harmful contaminants …


Population And Diet Assessment Of White Bass In Lake Sharpe, South Dakota, Andrew E. Ahrens, Travis W. Schaeffer, Melissa R. Wuellner, David W. Willis Dec 2010

Population And Diet Assessment Of White Bass In Lake Sharpe, South Dakota, Andrew E. Ahrens, Travis W. Schaeffer, Melissa R. Wuellner, David W. Willis

The Prairie Naturalist

White bass (Morone chrysops) have been introduced into all 4 South Dakota Missouri River reservoirs and compose a substantial proportion of the annual recreational harvest. To date, limited studies have examined white bass population dynamics and food habits in South Dakota Missouri River reservoirs. Our objective was to examine population dynamics and food habits of white bass in Lake Sharpe, a South Dakota mainstem Missouri River reservoir. White bass consistently consumed invertebrates during May but switched to a more piscivorous diet later in the growing season; most of the fish consumed were gizzard shad (Dorosoma cepedianum). …


Correlation Of Mature Walleye Relative Abundance To Egg Density, Jordan D. Katt, Casey W. Schoenebeck, Keith D. Koupal, Brian C. Peterson, W. Wyatt Hoback Dec 2010

Correlation Of Mature Walleye Relative Abundance To Egg Density, Jordan D. Katt, Casey W. Schoenebeck, Keith D. Koupal, Brian C. Peterson, W. Wyatt Hoback

The Prairie Naturalist

Knowledge of spawning areas can benefit fisheries management (Marsden et al. 1991). Identification of spawning areas allows managers to protect, enhance, and/or restore critical habitat (Gunn et al. 1996, Thompson 2009), examine important biotic and abiotic conditions necessary for reproduction (Quist et al. 2003), and to efficiently collect broodstock for production (Satterfield and Flickinger 1996). The most effective method to directly identify spawning areas of fish with demersal eggs is to sample the substrate for eggs (Marsden et al. 1991). This method has been used to locate spawning areas of several species (Michaletz 1984, Zorn et al. 1998, Martin 2008). …


The Prairie Naturalist, Vol. 42, Issue 3/4, December 2010, The Great Plains Natural Science Society Dec 2010

The Prairie Naturalist, Vol. 42, Issue 3/4, December 2010, The Great Plains Natural Science Society

The Prairie Naturalist

EDITOR'S NOTE: REPORTING RESULTS OF DATA ANALYSIS, PREPARING SCIENTIFIC MANUSCRIPTS, AND WEBSITE DEVELOPMENT EFFORTS • Christopher N. Jacques

Current Distribution of Rare Fishes in Eastern Wyoming Prairie Streams • Christina E. Barrineau, Elizabeth A. Bear, and Anna C. Senecal

Diets of Nesting Swainson's Hawks in Relation to Land Cover in Northwestern North Dakota • Robert K. Murphy

Resource Selection of Greater Prairie-Chicken and and Sharp-Tailed Grouse Broods in Central South Dakota • Mark A. Norton, Kent C. Jensen, Anthony P. Leif, Thomas R. Kirschenmann, and Gregory A. Wolbrink

Population Characteristics of Central Stonerollers in Iowa Streams • Scott M Bisping, …


Population Characteristics Of Central Stonerollers In Iowa Streams, Scott M. Bisping, Jesse R. Fischer, Michael C. Quist, Andrew J. Schaefer Dec 2010

Population Characteristics Of Central Stonerollers In Iowa Streams, Scott M. Bisping, Jesse R. Fischer, Michael C. Quist, Andrew J. Schaefer

The Prairie Naturalist

The central stoneroller (Campostoma anomalum) is a herbivore that can have substantial effects on algal communities, nutrient dynamics, and energy flow in streams. Despite its importance in lotic ecosystems, little is known about its population dynamics in streams of the Great Plains. Our objective was to describe age structure, age-specific mortality, and growth rates of central stonerollers in three Iowa streams. We sampled fish from 41 reaches during June-August 2007. We sampled 466 central stonerollers, of which we aged 192. Fish varied in length from 32 to 130 mm and in age from age 0 to 4 years. …


The Recordlinkage Package: Detecting Errors In Data, Murat Sariyar, Andreas Borg Dec 2010

The Recordlinkage Package: Detecting Errors In Data, Murat Sariyar, Andreas Borg

The R Journal

Record linkage deals with detecting homonyms and mainly synonyms in data. The package RecordLinkage provides means to per form and evaluate different record linkage methods. A stochastic framework is implemented which calculates weights through an EM algorithm. The determination of the necessary thresholds in this model can be achieved by tools of extreme value theory. Furthermore, machine learning methods are utilized, including decision trees (rpart), bootstrap aggregating (bagging), ada boost (ada), neural nets (nnet) and support vector machines (svm). The generation of record pairs and comparison patterns from single data …


Stringr: Modern, Consistent String Processing, Hadley Wickham Dec 2010

Stringr: Modern, Consistent String Processing, Hadley Wickham

The R Journal

String processing is not glamorous, but it is frequently used in data cleaning and preparation. The existing string functions in R are powerful, but not friendly. To remedy this, the stringr package provides string functions that are simpler and more consistent, and also fixes some functionality that R is missing compared to other programming languages.


Solving Differential Equations In R, Karline Soetaert, Thomas Petzoldt, R. Woodrow Setzer Dec 2010

Solving Differential Equations In R, Karline Soetaert, Thomas Petzoldt, R. Woodrow Setzer

The R Journal

Although R is still predominantly applied for statistical analysis and graphical representation, it is rapidly becoming more suitable for mathematical computing. One of the fields where considerable progress has been made recently is the solution of differential equations. Here we give a brief overview of differential equations that can now be solved by R.


Online Reproducible Research: An Application To Multivariate Analysis Of Bacterial Dna Fingerprint Data, Jean Thioulouse, Claire Valiente-Moro, Lionel Zenner Dec 2010

Online Reproducible Research: An Application To Multivariate Analysis Of Bacterial Dna Fingerprint Data, Jean Thioulouse, Claire Valiente-Moro, Lionel Zenner

The R Journal

This paper presents an example of online reproducible multivariate data analysis. This example is based on a web page providing an online computing facility on a server. HTML forms contain editable R code snippets that can be executed in any web browser thanks to the Rweb software. The example is based on the multivariate analysis of DNA fingerprints of the internal bacterial flora of the poultry red mite Dermanyssus gallinae. Several multivariate data analysis methods from the ade4 package are used to compare the fingerprints of mite pools coming from various poultry farms. All the computations and graphical displays …


Mapping And Measuring Country Shapes, Nils B. Weidmann, Kristian Skrede Gleditsch Dec 2010

Mapping And Measuring Country Shapes, Nils B. Weidmann, Kristian Skrede Gleditsch

The R Journal

The article introduces the cshapes R package, which includes our CShapes dataset of contemporary and historical country boundaries, as well as computational tools for computing geographical measures from these maps. We provide an overview of the need for considering spatial dependence in comparative re search, how this requires appropriate historical maps, and detail how the cshapes associated R package cshapes can contribute to these ends. We illustrate the use of the package for drawing maps, computing spatial variables for countries, and generating weights matrices for spatial statistics.


A Concise Synthesis Of Β-Sitosterol And Other Phytosterols, Jiliang Hang, Patrick Dussault Dec 2010

A Concise Synthesis Of Β-Sitosterol And Other Phytosterols, Jiliang Hang, Patrick Dussault

Patrick Dussault Publications

A convenient synthesis of sidechain-modified phytosterols is achieved via a temporary masking of the stigmasterol 5,6-alkene as an epoxide. Following performance of the desired modification, the alkene is regenerated through a mild deoxygenation. The approach is applied to the syntheses of β-sitosterol and campesterol acetate, and suggests a facile route to the (Z)-isomers of Δ22–23 phytosterols.

Includes Supplementary Data.


Does Socio/Economic Status Affect Environmental Awareness In Elementary School Children Interacting With School Gardens?, Grady C. Erickson Dec 2010

Does Socio/Economic Status Affect Environmental Awareness In Elementary School Children Interacting With School Gardens?, Grady C. Erickson

Department of Environmental Studies: Undergraduate Student Theses

This is a case study involving three elementary schools in the greater Lincoln, Nebraska area. These schools were chosen to provide insight to three different economic backgrounds. Saratoga and Randolph from Lincoln Public Schools, and Norris Elementary part of Norris Public Schools 160 was the third school involved in the study. This case study focused on seeing whether socio/economic background had any effect on environmental awareness. To do so, surveys were handed out to each school to help measure environmental awareness. These surveys also helped determine where the environmental literacy standards were in the elementary schools of Lincoln, Nebraska. The …


Recent Legislation To Promote Wind Energy In Nebraska, Ryan Lemke Dec 2010

Recent Legislation To Promote Wind Energy In Nebraska, Ryan Lemke

Department of Environmental Studies: Undergraduate Student Theses

Nebraska is currently ranked 4th in the nation for wind energy potential, but ranks low in actual wind power production. The lack of wind energy production could be the result of Nebraska’s unique public power districts that have eminent domain of distribution and retail sales of electricity in the State. Public Power districts are prohibited from receiving benefits of state and federal tax incentives for the development of wind farms, however some Nebraska power districts still pursue wind energy as a renewable source of energy.

Recent legislation changes, including the passing of laws LB629 and LB1048, have provided the State …


Educators' Attitudes Toward Outdoor Classrooms And The Cognitive Benefits In Children, Carlie Speedlin Dec 2010

Educators' Attitudes Toward Outdoor Classrooms And The Cognitive Benefits In Children, Carlie Speedlin

Department of Environmental Studies: Undergraduate Student Theses

A case study was organized at a K-5 elementary school in Lincoln, Nebraksa. This school is Saratoga Elementary School and is a United States Title I Distinguished School1 under No Child Left Behind. It has a population of 266 students, with 47% being minority, 1% gifted, and 28% special education (LPS School Profile Brochure). 80% of the student population is eligible for free/reduced meals, implying that it’s a school with a lower socioeconomic status. At this school a garden space was constructed and an after school garden club was implemented for this case study. The club had been running since …


How Are The Torres Strait Islander's Traditional Hunting Practices Affected By The Current Rate Of Decline In Dugong And Sea Turtle Populations And The Australian Government's Co-Management Policies On Marine Preservation?, Katilyn Price Dec 2010

How Are The Torres Strait Islander's Traditional Hunting Practices Affected By The Current Rate Of Decline In Dugong And Sea Turtle Populations And The Australian Government's Co-Management Policies On Marine Preservation?, Katilyn Price

Department of Environmental Studies: Undergraduate Student Theses

This paper will attempt to identify the extent to which the Torres Strait Islanders traditional hunting practices have been disrupted by the overall decline in dugong and sea turtle populations, which has directly correlated to an increase in hunting restrictions put in place by the Australian Government. The traditional hunting of dugongs and sea turtles provides not only a food source, but brings prestige to the men who catch them and serves as an educational platform to teach the younger generations about their culture. There are many environmental threats that impact the populations of sea turtles and dugongs though the …


The Cohomology Of Modules Over A Complete Intersection Ring, Jesse Burke Dec 2010

The Cohomology Of Modules Over A Complete Intersection Ring, Jesse Burke

Department of Mathematics: Dissertations, Theses, and Student Research

We investigate the cohomology of modules over commutative complete intersection rings. The first main result is that if M is an arbitrary module over a complete intersection ring R, and if one even self-extension module of M vanishes then M has finite projective dimension. The second main result gives a new proof of the fact that the support variety of a Cohen-Macaulay module whose completion is indecomposable is projectively connected.


An Investigation Of Sustainable Environmental Practices And Consumer Attitudes & Behaviors Toward Hotel Bathroom Amenities, Edward James Bobbett Dec 2010

An Investigation Of Sustainable Environmental Practices And Consumer Attitudes & Behaviors Toward Hotel Bathroom Amenities, Edward James Bobbett

UNLV Theses, Dissertations, Professional Papers, and Capstones

In the 1980s hotel operators became concerned with greening and sustainability. It was at this time the hospitality industry began focusing on energy efficiency and the sustainable development of tourism (Chan & Lam, 2001; Welford, Ytterhus, & Eligh, 1999). Since then, a global trend has emerged as hotels introduce programs to reduce the amount of resources used and the overall environmental impact they have on the planet, or their carbon footprint. The hospitality industry has introduced programs such as recycling in both the front and back of the house, energy-efficient lighting, towel re-use programs, linen exchange programs, Green Certifications, and …


Electrochemical Investigation Of Azurin Thermodynamic And Adsorption Properties At Monolayer-Protected Cluster Film Assemblies – Evidence For A More Homogeneous Adsorption Interface, Tran Doan, Morgan Lynn Vargo, John K. Gerig, Chris P. Gulka, Matthew L. Trawick, Jonathan D. Dattelbaum, Michael C. Leopold Dec 2010

Electrochemical Investigation Of Azurin Thermodynamic And Adsorption Properties At Monolayer-Protected Cluster Film Assemblies – Evidence For A More Homogeneous Adsorption Interface, Tran Doan, Morgan Lynn Vargo, John K. Gerig, Chris P. Gulka, Matthew L. Trawick, Jonathan D. Dattelbaum, Michael C. Leopold

Chemistry Faculty Publications

Thermodynamic and adsorption properties of protein monolayer electrochemistry (PME) are examined for Pseudomonas aeruginosa azurin (AZ) immobilized at an electrode modified with a networked film of monolayer-protected clusters (MPCs) to assess if nanoparticle films of this nature offer a more homogeneous adsorption interface compared to traditional self-assembled monolayer (SAM) modified electrodes. Specifically, electrochemistry is used to assess properties of surface coverage, formal potential, peak broadening, and electron transfer (ET) kinetics as a function of film thickness. The modification of a surface with dithiol-linked films of MPCs (Au225C675) provides a more uniform binding interface for AZ that results in voltammetry with …


Revisiting Address Space Randomization, Zhi Wang, Renquan Cheng, Debin Gao Dec 2010

Revisiting Address Space Randomization, Zhi Wang, Renquan Cheng, Debin Gao

Research Collection School Of Computing and Information Systems

Address space randomization is believed to be a strong defense against memory error exploits. Many code and data objects in a potentially vulnerable program and the system could be randomized, including those on the stack and heap, base address of code, order of functions, PLT, GOT, etc. Randomizing these code and data objects is believed to be effective in obfuscating the addresses in memory to obscure locations of code and data objects. However, attacking techniques have advanced since the introduction of address space randomization. In particular, return-oriented programming has made attacks without injected code much more powerful than what they …


Sequence Alignment Based Analysis Of Player Behavior In Massively Multiplayer Online Role-Playing Games (Mmorpgs), Kyong Jin Shim, Jaideep Srivastava Dec 2010

Sequence Alignment Based Analysis Of Player Behavior In Massively Multiplayer Online Role-Playing Games (Mmorpgs), Kyong Jin Shim, Jaideep Srivastava

Research Collection School Of Computing and Information Systems

This study proposes a sequence alignment-based behavior analysis framework (SABAF) developed for predicting inactive game players that either leave the game permanently or stop playing the game for a long period of time. Sequence similarity scores and derived statistics form profile databases of inactive players and active players from the past. SABAF uses global and local sequence alignment algorithms and a unique scoring scheme to measure similarity between activity sequences. SABAF is tested on the game player activity data of Ever Quest II, a popular massively multiplayer online role-playing game developed by Sony Online Entertainment. SABAF consists of the following …


Evaluation Of Protein Backbone Alphabets : Using Predicted Local Structure For Fold Recognition, Kyong Jin Shim Dec 2010

Evaluation Of Protein Backbone Alphabets : Using Predicted Local Structure For Fold Recognition, Kyong Jin Shim

Research Collection School Of Computing and Information Systems

Optimally combining available information is one of the key challenges in knowledge-driven prediction techniques. In this study, we evaluate six Phi and Psi-based backbone alphabets. We show that the addition of predicted backbone conformations to SVM classifiers can improve fold recognition. Our experimental results show that the inclusion of predicted backbone conformations in our feature representation leads to higher overall accuracy compared to when using amino acid residues alone.


2-D Path Planning For Direct Laser Deposition Process, Swathi Routhu, Divya Kanakanala, Jianzhong Ruan, Xiaoqing Frank Liu, Frank Liou Dec 2010

2-D Path Planning For Direct Laser Deposition Process, Swathi Routhu, Divya Kanakanala, Jianzhong Ruan, Xiaoqing Frank Liu, Frank Liou

Computer Science Faculty Research & Creative Works

The zigzag and offset path have been the two most popular path patterns for tool movement in machining process. Different from the traditional machining processes, the quality of parts produced by the metal deposition process is much more dependent upon the choice of deposition paths. Due to the nature of the metal deposition processes, various tool path patterns not only change the efficiency but also affect the deposition height, a critical quality for metal deposition process. This paper presents the research conducted on calculating zigzag pattern to improve efficiency by minimizing the idle path. the deposition height is highly dependent …


A Comprehensive Rocket And Radar Study Of Midlatitude Spread F, G.D. Earle, P. Bhaneja, P.A. Roddy, C.M. Swenson, A. Barjatya, R. L. Bishop, Et. Al Dec 2010

A Comprehensive Rocket And Radar Study Of Midlatitude Spread F, G.D. Earle, P. Bhaneja, P.A. Roddy, C.M. Swenson, A. Barjatya, R. L. Bishop, Et. Al

Publications

An instrumented sounding rocket launched from Wallops Island Virginia has flown through a midlatitude spread F (MSF) event in conjunction with simultaneous ionosonde, HF radar, and 244 MHz scintillation observations from the ground. The in situ measurements include the electric field, horizontal neutral wind, and plasma density within the spread F region. The ground‐based HF radar measurements of wave signatures in the bottomside F region ledge reveal the presence of waves propagating to the north and northwest prior to and during the spreading event. The periods of these bottomside waves range from 16 to 60 min, and they are shown …


Lsuhsc Facilities Daily Update: December 2010, Lsuhsc Property And Facilities Management Dec 2010

Lsuhsc Facilities Daily Update: December 2010, Lsuhsc Property And Facilities Management

LSUHSC Facilities Daily Updates: 2010

LSUHSC Facilities Daily Updates from December 2010.

On the original documents, the daily update for Thursday, December 2, 2010 is misdated as Thursday, November 2, 2010; and the daily update for Thursday, December 9, 2010 is misdated as Thursday, December 10, 2010.

These updates describe damage and a timeline of repairs at the LSU Health Sciences Center - New Orleans campus due to Hurricane Katrina which made landfall August 29, 2005.


Lsuhsc Facilities Biweekly Update: December 2010, Lsuhsc Property And Facilities Management Dec 2010

Lsuhsc Facilities Biweekly Update: December 2010, Lsuhsc Property And Facilities Management

LSUHSC Facilities Biweekly Updates: 2010

LSUHSC Facilities Biweekly Updates from December 3 and 17, 2010.

These updates describe damage and a timeline of repairs at the LSU Health Sciences Center - New Orleans campus due to Hurricane Katrina which made landfall August 29, 2005.