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2011

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Articles 241 - 270 of 7739

Full-Text Articles in Physical Sciences and Mathematics

Acknowledgements, The Mcnair Team Dec 2011

Acknowledgements, The Mcnair Team

McNair Scholars Research Journal

No abstract provided.


Mcnair Scholars Program, The Mcnair Team Dec 2011

Mcnair Scholars Program, The Mcnair Team

McNair Scholars Research Journal

No abstract provided.


Review Of Teaching Children Science: Hands-On Nature Study In North America, 1890-1930 By Sally Kohlstedt, Meena M. Balgopal Dec 2011

Review Of Teaching Children Science: Hands-On Nature Study In North America, 1890-1930 By Sally Kohlstedt, Meena M. Balgopal

The Prairie Naturalist

Many scientists and educators agree that the goal of science education is to prepare students "to know, use and interpret scientific explanations of the natural world," as cited in the National Research Council publication, Taking Science to School: Learning and Teaching Science in Grades K-8 (DuschI et al. 2007). Yet, many science instructors of K-12 and post-secondary students often rely on teacher-telling modes of pedagogy and neglect to engage their students in natural inquiry and scientific study that model the research methods used by scientists. As a result, many young people are not aware of how scientists make discoveries about …


Review Of Sandhill And Whooping Cranes: Ancient Voices Over America's Wetlands\ By Paul Johnsgard, Jane Austin Dec 2011

Review Of Sandhill And Whooping Cranes: Ancient Voices Over America's Wetlands\ By Paul Johnsgard, Jane Austin

The Prairie Naturalist

Paul Johnsgard has long been captivated by wild cranes and their unique vocalizations, courtship dances, and wide-ranging migrations. As a scientist and an admirer, Johnsgard has watched their migrations and behaviors for decades as hundreds of thousands of cranes staged each spring by the central Platte River, not far from his home in Lincoln, Nebraska. As an artist, he has skillfully captured their courtship dances and other behaviors in his exceptional line drawings. And, as an author, he has written extensively on their ecology in three earlier books: Cranes of the World (1983), Those of the Gray Wind: The Sandhill …


Genetic Structure Of Grass Carp Populations In The Missouri And Mississippi River Basins, Usa, Bobbi M. Adams, Katie N. Bertrand, Michael L. Brown, Donald Auger Dec 2011

Genetic Structure Of Grass Carp Populations In The Missouri And Mississippi River Basins, Usa, Bobbi M. Adams, Katie N. Bertrand, Michael L. Brown, Donald Auger

The Prairie Naturalist

We provided an early characterization of the genetic structure of the grass carp (Ctenopharyngodon idella) population as it expands its distribution in both the Missouri and Mississippi River basins. Further, we provided initial comparisons of allelic richness at 17 polymorphic microsatellite markers between 56 grass carp from the USA, and six from the Yangtze River in China. The number of alleles per locus ranged from two to eight and size ranges of alleles for fish collected from the invaded and native ranges were similar (P ≤ 0.001; 107–226 bp) to those previously reported in the literature. Distance-based clustering …


Massasauga Repatriation On A Restored Wet Prairie, Francis E. Durbian, Brian N. Lomas, Jeff Briggler, Paul Mckenzie, Tom Nagel Dec 2011

Massasauga Repatriation On A Restored Wet Prairie, Francis E. Durbian, Brian N. Lomas, Jeff Briggler, Paul Mckenzie, Tom Nagel

The Prairie Naturalist

The massasauga (Sistrurus catenatus) is a small rattlesnake that occurs from Texas to New York (Schmidt and Davis 1941, Conant and Collins 1991, Szymanski 1998). In Missouri, the Eastern massasauga rattlesnake (EMR; S. c. catenatus), a subspecies of the massasauga, occurs north and east of the Missouri River, is a former candidate for listing under the United States Endangered Species Act (Code of Federal Regulations 64 FR 57534; Szymanski 1998), and is listed as a state endangered species (Missouri Natural Heritage Program 2011). Missouri currently harbors five extant EMR populations (Johnson 2000, Durbian et al., unpublished report, …


Book Review Of Encyclopedia Of Biological Invasions, Edited By Daniel Simberloff And Marcel Rejmanek, Qinfeng Guo Dec 2011

Book Review Of Encyclopedia Of Biological Invasions, Edited By Daniel Simberloff And Marcel Rejmanek, Qinfeng Guo

The Prairie Naturalist

Book review of Encyclopedia of Biological Invasions, edited by Daniel Simberloff and Marcel Rejmanek.

Species introductions and consequent biotic invasions and homogenization are major components of global change that are drawing increasing concern and various levels of actions and reactions around the world. Invasion ecology has advanced rapidly during the last few decades, and the discipline is now increasingly integrated with the social and economic sciences. A better understanding of the invasion process and its effects is thus clearly needed. For basic research, invasion biology offers fascinating and sometimes unique opportunities for testing certain ecological or evolutionary theories and …


Depth And Littoral Habitat Association Of Age-0 Yellow Perch In Two South Dakota Glacial Lakes, Daniel J. Dembkowski, Melissa R. Wuellner, David W. Willis Dec 2011

Depth And Littoral Habitat Association Of Age-0 Yellow Perch In Two South Dakota Glacial Lakes, Daniel J. Dembkowski, Melissa R. Wuellner, David W. Willis

The Prairie Naturalist

Yellow perch (Perca flavescens) are a recreationally important species and represent a key ecological component of glacial lake littoral fish assemblages (Stone 1996, Blackwell et al. 1999). Research has shown a generalized pattern of juvenile (age-0) yellow perch spatial distribution wherein larvae hatch in near-shore areas, migrate to limnetic areas where they remain for approximately 40 d, and then return to demersal behaviors and within near-shore littoral habitats (Noble 1975, Whiteside et al. 1985). However, anomalous distribution and habitat use by age-0 yellow perch has been observed in South Dakota glacial lakes (Fisher and Willis 1997) and the …


Notes On The Distribution Of Eastern Woodrats And Hispid Cotton Rats In South-Central Nebraska, Heather D. Wills, Keith Geluso, Eric J. Smits, Joseph T. Springer, Wesley E. Newton Dec 2011

Notes On The Distribution Of Eastern Woodrats And Hispid Cotton Rats In South-Central Nebraska, Heather D. Wills, Keith Geluso, Eric J. Smits, Joseph T. Springer, Wesley E. Newton

The Prairie Naturalist

The eastern woodrat (Neotoma floridana) and hispid cotton rat (Sigmodon hispidus) reach distributional limits in southern Nebraska (Jones 1964, Farney 1975). In the last half-century, both species have expanded their distributional ranges in the region (Kugler and Geluso 2009, Wright et al. 2010). Herein, we report new localities of occurrence for both species that extend known distributional boundaries in south-central Nebraska beyond those reported by Kugler and Geluso (2009) and Wright et al. (2010).

Associated with other studies, we captured small mammals in Sherman live-traps in south-central Nebraska. Voucher specimens were deposited in collections at the …


Comparison Of Fish Communities In Recently Constructed Side-Channel Chutes With The Main Stem Missouri River, Kasey Whiteman, Vincent H. Travnichek, Darrick L. Garner, Brandon Eder, Kirk Steffensen Dec 2011

Comparison Of Fish Communities In Recently Constructed Side-Channel Chutes With The Main Stem Missouri River, Kasey Whiteman, Vincent H. Travnichek, Darrick L. Garner, Brandon Eder, Kirk Steffensen

The Prairie Naturalist

Two United States Army Corp of Engineers- (USACE) funded projects were conducted from 2006 to 2008 along the Missouri River to monitor fish communities in recently constructed side-channel chutes and to monitor pallid sturgeon (Scaphirhynchus albus) and the associated fish assemblage in the main stem Missouri River. Data from both monitoring projects were compared to evaluate fish assemblages among four mitigated habitats (e.g., constructed side-channel chutes) and the main-stem Missouri River. Chutes had a greater overall number of species (n = 59) and higher species richness (Margalef’s index = 5.81), but richness was not different (F1, 4 = …


Patterns Of Age-0 Gizzard Shad Abundance And Food Habits In A Nebraska Irrigation Reservoir, Christopher L. Sullivan, Casey W. Schoenebeck, Keith D. Koupal, W. Wyatt Hoback, Brian C. Peterson Dec 2011

Patterns Of Age-0 Gizzard Shad Abundance And Food Habits In A Nebraska Irrigation Reservoir, Christopher L. Sullivan, Casey W. Schoenebeck, Keith D. Koupal, W. Wyatt Hoback, Brian C. Peterson

The Prairie Naturalist

Gizzard shad (Dorosoma cepedianum) are prolific spawners that can influence reservoir communities. Larval gizzard shad may compete with larval recreational fish for zooplankton resources. Therefore, it is necessary to determine larval gizzard shad dynamics and food habits to better understand their potential for competition with larval recreational fish. Our study examined age-0 gizzard shad abundance in Harlan County Reservoir during late spring/summer from 2002–2010 and food habits and prey electivity of age-0 gizzard shad during late spring/summer 2008 and 2009. The annual peak age-0 gizzard shad density 3 from 2002–2010 ranged from 50 to 380/100 m , which …


Northern Harrier Hatches Mallard Nest, Jeffery W. Stackhouse, Benjamin A. Geaumont Dec 2011

Northern Harrier Hatches Mallard Nest, Jeffery W. Stackhouse, Benjamin A. Geaumont

The Prairie Naturalist

The northern harrier (Circus cyaneus) is a widespread raptor commonly found nesting throughout the Northern Great Plains. Northern harriers forage primarily on small mammals and passerines with the males providing the majority of prey to nestlings until 14–28 days of age (Redpath et al. 2006, Vukovich and Ritchison 2006). Although the genus Circus is known to predate eggs from nest of many nesting birds (Hiraldo et al. 1975, Donaszar et al. 1996, Opermanis et al. 2000), few have been recorded commandeering nests of different species (Laine 1928, Fleskes 1992). In June 2010, we observed a northern harrier that …


Late Seasonal Captures Of The Plains Pocket Mouse (Perognathus Flavescens) In Iowa, Hans W. Otto, Jeremy A. White Dec 2011

Late Seasonal Captures Of The Plains Pocket Mouse (Perognathus Flavescens) In Iowa, Hans W. Otto, Jeremy A. White

The Prairie Naturalist

The plains pocket mouse, Perognathus flavescens, is a nocturnal granivore that inhabits friable soils in sparsely vegetated areas (Monk and Jones 1996). In the United States, the distribution of the plains pocket mouse extends from Arizona, New Mexico, and Texas through the Great Plains to North Dakota and Minnesota (Hall 1981). This species reaches its easternmost limits in Iowa, where it has been documented from a limited number of grassland sites in eastern, central, and western parts of the state (Bowles 1975, Wilson et al. 1996). Due to loss of grassland habitat, the plains pocket mouse is currently listed …


Book Review: Effects Of Climate Change On Birds, Edited By Anders Pape Meller, Wolfgang Fiedler, And Peter Berthold, Brian J. Olsen Dec 2011

Book Review: Effects Of Climate Change On Birds, Edited By Anders Pape Meller, Wolfgang Fiedler, And Peter Berthold, Brian J. Olsen

The Prairie Naturalist

Book review of Effects of Climate Change on Birds, edited by Anders Pape Meller, Wolfgang Fiedler, and Peter Berthold.

Climate scientists from across the globe predict vast changes during the next century in the planet's temperatures, precipitation, storm intensities, fire regimes, hydrologic cycles, and atmospheric, water, and soil chemistries. The changes will be global, but their effects will be felt locally everywhere. To find a scientifically and socially engaging bellwether of these events, we need to look only through the lens of avian biology. Birds are found from pole to pole; their movements connect continents. They are loud, colorful …


Modeling Parental Provisioning By Red-Winged Blackbirds In North Dakota, George M. Linz, Richard S. Sawin, Mark W. Lutman, William J. Bleier Dec 2011

Modeling Parental Provisioning By Red-Winged Blackbirds In North Dakota, George M. Linz, Richard S. Sawin, Mark W. Lutman, William J. Bleier

The Prairie Naturalist

Male red-winged blackbirds (Agelaius phoeniceus) exhibit a difference in nest provisioning rates along an east-west gradient in North America. North Dakota is located in the center of North America and harbors a large population of breeding red-winged blackbirds (RWBL). This location provided an opportunity to compare provisioning rates in the central U.S. with those reported for the eastern and western populations. We placed video cameras at RWBL nests to record male and female feeding trips. Thirty-four nests were located on territories with original males and 30 were on territories where a replacement (floater) male had taken over a …


Manuscript Content: Where Does It Belong?, Christopher N. Jacques Dec 2011

Manuscript Content: Where Does It Belong?, Christopher N. Jacques

The Prairie Naturalist

One of the most common issues we address during content editing of papers for The Prairie Naturalist (journal) is the appropriate placement of content in the text body. Based on my experience with the editorial process, content placement also is one of the issues that authors are most resistant to suggestions or do not fully understand why we are so persistent about it (Thompson 2010). One of the primary objectives of scientific writing is to concisely and accurately disseminate information. Scientific papers are structured to help both the author and reader accomplish this objective. The material that belongs in each …


Rainbow: An R Package For Visualizing Functional Time Series, Han Lin Shang Dec 2011

Rainbow: An R Package For Visualizing Functional Time Series, Han Lin Shang

The R Journal

Recent advances in computer technology have tremendously increased the use of functional data, whose graphical representation can be infinite-dimensional curves, images or shapes. This article describes four methods for visualizing functional time series using an R add-on package. These methods are demonstrated using age-specific Australian fertility data from 1921 to 2006 and monthly sea surface temperatures from January 1950 to December 2006.


Using The Google Visualisation Api With R, Markus Gesmann, Diego De Castillo Dec 2011

Using The Google Visualisation Api With R, Markus Gesmann, Diego De Castillo

The R Journal

The googleVis package provides an interface between R and the Google Visualisation API to create interactive charts which can be embedded into web pages. The best known of these charts is probably the Motion Chart, popularised by Hans Rosling in his TED talks. With the googleVis package users can easily create web pages with interactive charts based on R data frames and display them either via the local R HTTPhelp server or within their own sites.


Ckmeans.1d.Dp: Optimal K-Means Clustering In One Dimension By Dynamic Programming, Haizhou Wang, Mingzhou Song Dec 2011

Ckmeans.1d.Dp: Optimal K-Means Clustering In One Dimension By Dynamic Programming, Haizhou Wang, Mingzhou Song

The R Journal

The heuristic k-means algorithm, widely used for cluster analysis, does not guarantee optimality. We developed a dynamic programming algorithm for optimal one-dimensional clustering. The algorithm is implemented as an R package called Ckmeans.1d.dp. We demonstrate its ad vantage in optimality and runtime over the standard iterative k-means algorithm.


Implementing The Compendium Concept With Sweave And Docstrip, Michael Lundholm Dec 2011

Implementing The Compendium Concept With Sweave And Docstrip, Michael Lundholm

The R Journal

This article suggests an implementation of the compendium concept by combining Sweave and the LATEX literate programming environment DOCSTRIP.


Content-Based Social Network Analysis Of Mailing Lists, Angela Bohn, Ingo Feinerer, Kurt Hornik, Patrick Mair Dec 2011

Content-Based Social Network Analysis Of Mailing Lists, Angela Bohn, Ingo Feinerer, Kurt Hornik, Patrick Mair

The R Journal

Social Network Analysis (SNA) provides tools to examine relationships between people. Text Mining (TM) allows capturing the text they produce in Web 2.0 applications, for example, however it neglects their social structure. This paper applies an approach to combine the two methods named “content-based SNA”. Using the R mailing lists, R-help and R-devel, we show how this combination can be used to describe people’s interests and to find out if authors who have similar interests actually communicate. We find that the expected positive relationship between sharing interests and communicating gets stronger as the centrality scores of authors in the communication …


Watch Your Spelling!, Kurt Hornik, Duncan Murdoch Dec 2011

Watch Your Spelling!, Kurt Hornik, Duncan Murdoch

The R Journal

We discuss the facilities in base R for spell checking via Aspell, Hunspell or Ispell, which are useful in particular for conveniently checking the spelling of natural language texts in package Rd files and vignettes. Spell checking performance is illustrated using the Rd files in package stats. This example clearly indicates the need for a domain-specific statistical dictionary. We analyze the results of spell checking all Rd files in all CRAN packages and show how these can be employed for building such a dictionary.


Nonparametric Goodness-Of-Fit Tests For Discrete Null Distributions, Taylor B. Arnold, John W. Emerson Dec 2011

Nonparametric Goodness-Of-Fit Tests For Discrete Null Distributions, Taylor B. Arnold, John W. Emerson

The R Journal

Methodology extending nonparametric goodness-of-fit tests to discrete null distributions has existed for several decades. However, modern statistical software has generally failed to provide this methodology to users. We offer a revision of R’s ks.test() function and a new cvm.test() function that fill this need in the R language for two of the most popular nonparametric goodness-of-fit tests. This paper describes these contributions and provides examples of their usage. Particular attention is given to various numerical issues that arise in their implementation.


Portable C++ For R Packages, Martyn Plummer Dec 2011

Portable C++ For R Packages, Martyn Plummer

The R Journal

Package checking errors are more common on Solaris than Linux. In many cases, these errors are due to non-portable C++ code. This article reviews some commonly recurring problems in C++ code found in R packages and suggests solutions.


Glm2: Fitting Generalized Linear Models With Convergence Problems, Ian C. Marschner Dec 2011

Glm2: Fitting Generalized Linear Models With Convergence Problems, Ian C. Marschner

The R Journal

The R function glm uses step-halving to deal with certain types of convergence problems when using iteratively reweighted least squares to fit a generalized linear model. This works well in some circumstances but non-convergence remains a possibility, particularly with a non standard link function. In some cases this is be cause step-halving is never invoked, despite a lack of convergence. In other cases step-halving is invoked but is unable to induce convergence. One remedy is to impose a stricter form of step halving than is currently available in glm, so that the deviance is forced to decrease in every iteration. …


Creating And Deploying An Application With (R)Excel And R, Thomas Baier, Erich Neuwirth, Michele De Meo Dec 2011

Creating And Deploying An Application With (R)Excel And R, Thomas Baier, Erich Neuwirth, Michele De Meo

The R Journal

We present some ways of using R in Excel and build an example application using the package rpart. Starting with simple interactive use of rpart in Excel, we eventually package the code into an Excel-based application, hiding all details (including R itself) from the end user. In the end, our application implements a service oriented architecture (SOA) with a clean separation of presentation and computation layer


Grapher: A Multiplatform Gui For Drawing Customizable Graphs In R, Maxime Hervé Dec 2011

Grapher: A Multiplatform Gui For Drawing Customizable Graphs In R, Maxime Hervé

The R Journal

This article presents GrapheR, a Graphical User Interface allowing the user to draw customizable and high-quality graphs without knowing any R commands. Six kinds of graph are available: histograms, box-and-whisker plots, bar plots, pie charts, curves and scatter plots. The complete process is described with the examples of a bar plot and a scatter plot illustrating the legendary puzzle of African and European swallows’ migrations.


Defining Conservation Priorities For Freshwater Fishes According To Taxonomic, Functional, And Phylogenetic Diversity, Angela L. Strecker, Julian D. Olden, Joanna B. Whittier, Craig Patrick Paukert Dec 2011

Defining Conservation Priorities For Freshwater Fishes According To Taxonomic, Functional, And Phylogenetic Diversity, Angela L. Strecker, Julian D. Olden, Joanna B. Whittier, Craig Patrick Paukert

Environmental Science and Management Faculty Publications and Presentations

To date, the predominant use of systematic conservation planning has been to evaluate and conserve areas of high terrestrial biodiversity. Although studies in freshwater ecosystems have received recent attention, research has rarely considered the potential trade-offs between protecting different dimensions of biodiversity and the ecological processes that maintain diversity. We provide the first systematic prioritization for freshwaters (focusing on the highly threatened and globally distinct fish fauna of the Lower Colorado River Basin, USA) simultaneously considering scenarios of: taxonomic, functional, and phylogenetic diversity; contemporary threats to biodiversity (including interactions with nonnative species); and future climate change and human population growth. …


Complex Dynamics Of Discrete Seis Models With Simple Demography, Hui Cao, Yicang Zhou, Baojun Song Dec 2011

Complex Dynamics Of Discrete Seis Models With Simple Demography, Hui Cao, Yicang Zhou, Baojun Song

Department of Applied Mathematics and Statistics Faculty Scholarship and Creative Works

We investigate bifurcations and dynamical behaviors of discrete SEIS models with exogenous reinfections and a variety of treatment strategies. Bifurcations identified from the models include period doubling, backward, forward-backward, and multiple backward bifurcations. Multiple attractors, such as bistability and tristability, are observed. We also estimate the ultimate boundary of the infected regardless of initial status. Our rigorously mathematical analysis together with numerical simulations show that epidemiological factors alone can generate complex dynamics, though demographic factors only support simple equilibrium dynamics. Our model analysis supports and urges to treat a fixed percentage of exposed individuals.


Electron Screening And Disorder-Induced Heating In Ultracold Neutral Plasmas, Mary Elizabeth Lyon Dec 2011

Electron Screening And Disorder-Induced Heating In Ultracold Neutral Plasmas, Mary Elizabeth Lyon

Theses and Dissertations

Disorder-induced heating (DIH) is a nonequilibrium, ultrafast relaxation process that occurs when laser-cooled atoms are photoionized to make an ultracold plasma. Its effects dominate the ion motion during the first 100 ns of the plasma evolution. Using tools of atomic physics we study DIH with ns time resolution for different plasma densities and temperatures. By changing the frequency of the laser beam we use to probe the ions, we map out the time evolution of the velocity distribution. We can compare this to a fluorescence simulation in order to more clearly determine the relationship between the fluorescence signal and the …