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Spectral Properties Of A Non-Compact Operator In Ecology, Matthew Reichenbach

Department of Mathematics: Dissertations, Theses, and Student Research

Ecologists have used integral projection models (IPMs) to study fish and other animals which continue to grow throughout their lives. Such animals cannot shrink, since they have bony skeletons; a mathematical consequence of this is that the kernel of the integral projection operator T is unbounded, and the operator is not compact. A priori, it is unclear whether these IPMs have an asymptotic growth rate λ, or a stable-stage distribution ψ. In the case of a compact operator, these quantities are its spectral radius and the associated eigenvector, respectively. Under biologically reasonable assumptions, we prove that the non-compact operators in …

Sestrins: Emerging Dynamic Stress-Sensors In Metabolic And Environmental Health, Seung Hyun Ro, Julianne Fay, Cesar I. Cyuzuzo, Yura Jang, Naeun Lee, Hyun Seob Song, Edward N. Harris

Department of Biochemistry: Faculty Publications

Proper timely management of various external and internal stresses is critical for metabolic and redox homeostasis in mammals. In particular, dysregulation of mechanistic target of rapamycin complex (mTORC) triggered from metabolic stress and accumulation of reactive oxygen species (ROS) generated from environmental and genotoxic stress are well-known culprits leading to chronic metabolic disease conditions in humans. Sestrins are one of the metabolic and environmental stress-responsive groups of proteins, which solely have the ability to regulate both mTORC activity and ROS levels in cells, tissues and organs. While Sestrins are originally reported as one of several p53 target genes, recent studies …

Open Access: “Information Wants To Be Free”?, Richard Poynder

Copyright, Fair Use, Scholarly Communication, etc.

The main points made in this document:

- Internet mantras like information wants to be free misled OA advocates about what is possible in an online world. Amongst other things, these mantras led to the mistaken belief that publishing would be very much cheaper on the internet.

- BOAI was intended to achieve three things: to resolve the longstanding problems of affordability, accessibility, and equity that have long dogged scholarly communication.

- It now seems unlikely that the affordability and equity problems will be resolved, which will impact disproportionately negatively on those in the Global South. And if the geopolitical …

The R Journal (December 2020) 12(2): Complete Issue, The R Foundation

The R Journal

Editorial, Michael J. Kane

Contributed Research Articles

The biglasso Package: A Memory- and Computation-Efficient Solver for Lasso Model Fitting with Big Data in R, Yaohui Zeng and Patrick Breheny

Comparing Multiple Survival Functions with Crossing Hazards in R, Hsin-wen Chang, Pei-Yuan Tsai, Jen-Tse Kao, and Guo-You Lan

A Unified Algorithm for the Non-Convex Penalized Estimation: The ncpen Package, Dongshin Kim, Sangin Lee, and Sunghoon Kwon

TULIP: A Toolbox for Linear Discriminant Analysis with Penalties, Yuqing Pan, Qing Mai, and Xin Zhang

fitzRoy: An R Package to Encourage Reproducible Sports Analysis, Robert Nguyen, James Day, David Warton, and Oscar Lane

Assembling …

The Sea Will Rise, Barbuda Will Survive: Environment And Time Consciousness, Sophia Perdikaris

School of Global Integrative Studies: Faculty Publications

In this article, we examine the link between environmental consciousnesses and time consciousness. We argue that the way people think about time shapes their experience of climate change threats. We contrast western hegemonic concepts of time—the Gregorian Calendar, the Dooms Day Clock, linear time—with the way Barbudans of Antigua and Barbuda, an island nation in the Caribbean experience time—cyclical, through boom and bust cycles. We found that this boom and bust framework was indeed supported by climate change and weather experiences on the island—hurricanes, droughts, changes in the lagoons—as well as economic experiences—cargo boat delays bringing supplies, paycheck delays. By …

The Nebraska Bird Review, Volume 88 December 2020 Number 4

Nebraska Bird Review

Fall Field Report, August - November 2020, by W. Ross Silcock …13.8

History of the Seward - Branched Oak Christmas Bird Count, 1993-2020, by Joseph Gubanyi …162

Index to Volume 88 … 173

Subscription and Organization Information …187

Fall Field Report, August-November 2020, W. Ross Silcock

Nebraska Bird Review

Two issues were of concern this fall, and both appeared to have consequences or at least similarities in Nebraska. A major die-off in New Mexico made national news: https://www.aba.org/the-data-behind-mysterious-bird-deaths-in-new-mexico/. On Sep 9, 2020, the temperature dropped from 96°F to 40°F in the Albuquerque area, a record low, winds reached 70 mph, and several inches of snow fell, killing large numbers of birds directly. Over the next few days, hundreds more dead birds were picked up. Some have linked this high mortality to birds displaced from the mountains due to fire and unfortunately being caught in the severe weather. While fire …

History Of The Seward-Branched Oak Lake Christmas Bird Count, 1993-2020, Joseph A. Gubanyi

Nebraska Bird Review

The Seward-Branched Oak Lake Christmas Bird Count (Seward-BOL CBC) began in 1993 and has been conducted every year since then except for 2010 for a total of 27 counts. Weather conditions prevented the count on the selected date in 2010 and a backup date could not be set up. The count was started for several reasons. The area west of Lincoln has a diversity of habitats including all or part of four public lakes (Branched Oak, Pawnee, Twin Lakes, and Meadowlark) as well as a diversity of terrestrial habitats on both public and private land. The circle is close to …

Index To Volume 88

Nebraska Bird Review

Index to The Nebraska Bird Review, Volume 88 (2020)

From: Aden, Scott 95

to: Zonotrichia leucophrys gambelii 158 leucophrys 70, 158 oriantha 70

Analyzing Basket Trials Under Multisource Exchangeability Assumptions, Michael J. Kane, Nan Chen, Alexander M. Kaizer, Xun Jiang, H Amy Xia, Brian P. Hobbs

The R Journal

Basket designs are prospective clinical trials that are devised with the hypothesis that the presence of selected molecular features determine a patient’s subsequent response to a particular “targeted” treatment strategy. Basket trials are designed to enroll multiple clinical subpopulations to which it is assumed that the therapy in question offers beneficial efficacy in the presence of the targeted molecular profile. The treatment, however, may not offer acceptable efficacy to all subpopulations enrolled. Moreover, for rare disease settings, such as oncology wherein these trials have become popular, marginal measures of statistical evidence are difficult to interpret for sparsely enrolled subpopulations. Consequently, …

A Fast And Scalable Implementation Method For Competing Risks Data With The R Package Fastcmprsk, Eric S. Kawaguchi, Jenny I. Shen, Gang Li, Marc A. Suchard

The R Journal

Advancements in medical informatics tools and high-throughput biological experimentation make large-scale biomedical data routinely accessible to researchers. Competing risks data are typical in biomedical studies where individuals are at risk to more than one cause (type of event) which can preclude the others from happening. The Fine and Gray (1999) proportional subdistribution hazards model is a popular and well-appreciated model for competing risks data and is currently implemented in a number of statistical software packages. However, current implementations are not computationally scalable for large-scale competing risks data. We have developed an R package, fastcmprsk, that uses a novel forward-backward scan …

Six Years Of Shiny In Research: Collaborative Development Of Web Tools In R, Peter Kasprzak, Lachlan Mitchell, Olena Kravchuk, Andy Timmins

The R Journal

The use of Shiny in research publications is investigated over the six and a half years since the appearance of this popular web application framework for R, which has been utilised in many varied research areas. While it is demonstrated that the complexity of Shiny applications is limited by the background architecture, and real security concerns exist for novice app developers, the collaborative benefits are worth attention from the wider research community. Shiny simplifies the use of complex methodologies for people of different specialities, at the level of proficiency appropriate for the end user. This enables a diverse community of …

Assembling Pharmacometric Datasets In R: The Puzzle Package, Mario González-Sales, Olivier Barrière, Pierre Olivier Tremblay, Guillaume Bonnefois, Julie Desrochers, Fahima Nekka

The R Journal

Pharmacometric analyses are integral components of the drug development process. The core of each pharmacometric analysis is a dataset. The time required to construct a pharmacometrics dataset can sometimes be higher than the effort required for the modeling per se. To simplify the process, the puzzle R package has been developed aimed at simplifying and facilitating the time consuming and error prone task of assembling pharmacometrics datasets.

Puzzle consist of a series of functions written in R. These functions create, from tabulated files, datasets that are compatible with the formatting requirements of the gold standard non-linear mixed effects modeling …

The Biglasso Package: A Memory- And Computation-Efficient Solver For Lasso Model Fitting With Big Data In R, Yaohui Zeng, Patrick Breheny

The R Journal

Penalized regression models such as the lasso have been extensively applied to analyzing high-dimensional data sets. However, due to memory limitations, existing R packages like glmnet and ncvreg are not capable of fitting lasso-type models for ultrahigh-dimensional, multi-gigabyte data sets that are increasingly seen in many areas such as genetics, genomics, biomedical imaging, and high-frequency finance. In this research, we implement an R package called biglasso that tackles this challenge. biglasso utilizes memory-mapped files to store the massive data on the disk, only reading data into memory when necessary during model fitting, and is thus able to handle out-of-core computation …

The Prairie Naturalist, Vol. 52, Issue 2, December 2020

The Prairie Naturalist

Comparing Native Bee Communities on Reconstructed and Remnant Prairie in Missouri • Joseph LaRose, Elisabeth B. Webb, and Deborah Finke

Patterns and Potential Causes of Changing Winter Bird Distributions in South Dakota • David L. Swanson, Reza Goljani Amipkhiz, and Mark D. Dixon

Greater prairie-chickens and sharp-tailed grouse have similarly high nest survival in the Nebraska Sandhills • Larkin A. Powell, Walter H. Schacht, Julia P. Ewalt, and Katie R. McCollum

Captive Ring-necked Pheasant Response to Very High Experimental Doses of Lead • Travis J. Runia and Alex J. Solem

Trends in a Greater Prairie Chicken Population Established by Translocation …

Rngforgpd: An R Package For Generation Of Univariate And Multivariate Generalized Poisson Data, Hesen Li, Hakan Demirtas, Ruizhe Chen

The R Journal

This article describes the R package RNGforGPD, which is designed for the generation of univariate and multivariate generalized Poisson data. Some illustrative examples are given, the utility and functionality of the package are demonstrated; and its performance is assessed via simulations that are devised around both artificial and real data.

Tulip: A Toolbox For Linear Discriminant Analysis With Penalties, Yuqing Pan, Qing Mai, Xin Zhang

The R Journal

Linear discriminant analysis (LDA) is a powerful tool in building classifiers with easy computation and interpretation. Recent advancements in science technology have led to the popularity of datasets with high dimensions, high orders and complicated structure. Such datasetes motivate the generalization of LDA in various research directions. The R package TULIP integrates several popular high-dimensional LDA-based methods and provides a comprehensive and user-friendly toolbox for linear, semi-parametric and tensor-variate classification. Functions are included for model fitting, cross validation and prediction. In addition, motivated by datasets with diverse sources of predictors, we further include functions for covariate adjustment. Our package is …

News From The Bioconductor Project, Bioconductor Core Team

The R Journal

Bioconductor provides tools for the analysis and comprehension of high-throughput genomic data. Bioconductor 3.12 was released on 28 October, 2020. It is compatible with R 4.0.3 and consists of 1974 software packages, 398 experiment data packages, 968 up-to-date annotation packages, and 28 workflows. Books are a new addition, built regularly from source and therefore fully reproducible; an example is the community-developed Orchestrating Single-Cell Analysis with Bioconductor.

A Unified Algorithm For The Non-Convex Penalized Estimation: The Ncpen Package, Dongshin Kim, Sangin Lee, Sunghoon Kwon

The R Journal

Various R packages have been developed for the non-convex penalized estimation but they can only be applied to the smoothly clipped absolute deviation (SCAD) or minimax concave penalty (MCP). We develop an R package, entitled ncpen, for the non-convex penalized estimation in order to make data analysts to experience other non-convex penalties. The package ncpen implements a unified algorithm based on the convex concave procedure and modified local quadratic approximation algorithm, which can be applied to a broader range of non-convex penalties, including the SCAD and MCP as special examples. Many user-friendly functionalities such as generalized information criteria, cross-validation …

Farmtest: An R Package For Factor-Adjusted Robust Multiple Testing, Koushiki Bose, Jianqing Fan, Yuan Ke, Xiaoou Pan, Wen-Xin Zhou

The R Journal

We provide a publicly available library FarmTest in the R programming system. This library implements a factor-adjusted robust multiple testing principle proposed by Fan et al. (2019) for large-scale simultaneous inference on mean effects. We use a multi-factor model to explicitly capture the dependence among a large pool of variables. Three types of factors are considered: observable, latent, and a mixture of observable and latent factors. The non-factor case, which corresponds to standard multiple mean testing under weak dependence, is also included. The library implements a series of adaptive Huber methods integrated with fast data-driven tuning schemes to estimate model …

Genomic Selection Of Forage Agronomic Traits In Winter Wheat, Frank Maulana, Ki-Seung Kim, Joshua D. Anderson, Mark E. Sorrells, Twain J. Butler, Shuyu Liu, P. Stephen Baenziger, Patrick Byrne, Xue-Feng Ma

Department of Agronomy and Horticulture: Faculty Publications

Genomic selection (GS) can improve genetic gain of complex traits in plant breeding. Phenotyping agronomic traits of winter wheat (Triticum aestivum L.) for dualpurpose use is expensive and time-consuming. In this study, we compared the prediction accuracies of four GS models (RR-BLUP, GBLUP, GAUSS, and BL) for forage yield (FY), plant height (PH) and heading date (HD) of the hard winter wheat diversity panel (n = 298) using random and stratified sampling methods. In addition, we determined the appropriate training population (TP) size and marker density for GS of the traits. Moderate to high prediction accuracies ranging from 0.66 …

Shedding Of Marburg Virus In Naturally Infected Egyptian Rousette Bats, South Africa, 2017, Janusz T. Pawęska, Nadia Storm, Wanda Markotter, Nicholas Di Paola, Michael R. Wiley, Gustavo Palacios, Petrus Jansen Van Vuren

University of Nebraska's National Strategic Research Institute: Publications

We detected Marburg virus RNA in rectal swab samples from Egyptian rousette bats in South Africa in 2017. This finding signifies that fecal contamination of natural bat habitats is a potential source of infection for humans. Identified genetic sequences are closely related to Ravn virus, implying wider distribution of Marburg virus in Africa.

The genus Marburgvirus, family Filoviridae, comprises 1 species, Marburg marburgvirus, which comprises 2 marburgviruses, Marburg virus (MARV) and Ravn virus (RAVV) (1). Marburgviruses cause sporadic but often fatal MARV disease in humans and nonhuman primates (2). The Egyptian rousette bat (Rousettus aegyptiacus) …

Reducing Mowing Requirements In Home Lawn And Golf Course Turfgrass, Mark A. Keck

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Turfgrass systems are routinely managed by frequent mowing to increase aesthetics and function. Mowing is resource intensive with a high labor and energy demand. Reducing the number of mowings events in a growing season will decrease the labor and energy but may reduce quality as well. Previous work has looked at reducing mowing by changing the frequency and by using a plant growth regulator (PGR). Limited information is available about how to reduce mowing while maintaining acceptable quality. We looked at two different management practices to reduce mowing and maintain quality. The first study evaluated seven different mowing frequencies at …

Evaluating The Impact Of Grafting On Local Tomato Production In Nebraska, Raihanah Hassim

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Vegetable grafting has been known to improve plant production under both biotic and abiotic stresses. With an increase in interest among local growers towards grafting production, it is important to provide enough vegetable grafting information. Therefore, the objective of this study is to assess the impact of grafting, rootstock cultivar, and local conditions and management on the yield and quality of tomato across the diverse growing and environmental conditions, specifically in Nebraska. Three open-field and one limited growing condition study were conducted between 2018 and 2019 across Nebraska. In the open-field trial, two determinant fresh market tomatoes, ‘Nebraska Wedding’ and …

Evolutionary Theory In Applied Problem-Solving, Lawrence C. Scharmann

Department of Teaching, Learning, and Teacher Education: Faculty Publications

Biology’s quest to be considered a mature science was initiated by Charles Darwin with the publication of On the Origin of Species2 in 1859. Naturalists quickly endorsed Darwin’s explanation for the relationships between similar species (i.e., common ancestry). Nonetheless, one of the arguments posed against evolution was that its supposed mechanism of action – namely natural selection – was considered conjecture at best since Darwin provided little in the way of evidence to support how natural selection might actually work. It was not until the 1930s when geneticists T.H. Morgan, Theodosius Dobzhansky, Ernst Mayr, and G. Gaylord Simpson noted that …

Relationship Between Personal Distress And Aggression Is Moderated By Nucleus Accumbens Volume, Yuan Ta Poh

College of Education and Human Sciences: Dissertations, Theses, and Student Research

Studies into the relationship between empathy and aggression has found that the effect is weak (Vachon et al., 2014). This weak relationship is observed through aspects of empathy interacting with aspects of aggression in different ways depending on the types of empathy and aggression being measured. The present study utilized neuroimaging approach to examine the relationship among empathy, aggression and nucleus accumbens (NAc) volume. Forty nine college students underwent magnetic resonance imaging scans and completed the Interpersonal Reactivity Index as well as the Reactive-Proactive Questionnaire. Using FreeSurfer, bilateral NAc volumes were obtained for statistical analysis. Hierarchal regression analyses were utilized …

The Influence Of Proximal And Distal Familial Factors On Preschool Children's Inhibitory Control And Social Emotional Skills, Amy Encinger

College of Education and Human Sciences: Dissertations, Theses, and Student Research

Children in the United States experience higher rates of poverty than any other age group, including elderly adults and the poverty rate of young children (0-5 years) is considerably higher than that of older children (Proctor et al., 2016). There is an extensive body of research examining familial socioeconomic status (SES) and the influence on the skills and behaviors of young children; however, common key indicators of family SES may not fully depict the ways in which children living in poverty/low-income homes are influenced by economic disadvantage. The focus of the current study is to explore the ways in which …

Assessment Of Grain Safety In Developing Nations, Jose R. Mendoza

Department of Food Science and Technology: Dissertations, Theses, and Student Research

Grains are the most widely consumed foods worldwide, with maize (Zea mays) being frequently consumed in developing countries where it feeds approximately 900 million people under the poverty line of 2 USD per day. While grain handling practices are acceptable in most developed nations, many developing nations still face challenges such as inadequate field management, drying, and storage. Faulty grain handling along with unavoidably humid climates result in recurrent fungal growth and spoilage, which compromises both the end-quality and safety of the harvest. This becomes particularly problematic where there is little awareness about health risks associated with poor …

Population Demographics, Distribution, And Environmental History Of Asian Carp In A Great Plains River, Jake Werner

School of Natural Resources: Dissertations, Theses, and Student Research

Silver Carp Hypophthalmichthys molitrix, Bighead Carp H. nobilis, and Black Carp Mylopharyngodon piceus, collectively known as Asian carp, are a group of invasive fishes in the U.S.A. that have garnered much attention over the last couple decades. Most research devoted to this group of fishes has been focused in the Mississippi River basin with little investigation in the Missouri River drainage, particularly in tributary systems. The Kansas River is a major tributary to the Missouri River that has multiple anthropogenic barriers creating varying levels of connectivity within the Kansas River itself, and with the Missouri River. Information …

The Application And Development Of Metabolomics Methodologies For The Profiling Of Food And Cellular Toxicity, Jade Woods

Department of Chemistry: Dissertations, Theses, and Student Research

Metabolomics is a rapidly growing field of study. Its growth reflects advancements in technology and an improved understanding of the impact of the environment on metabolism. As a result, metabolomics is now commonly employed to investigate and characterize human and plant metabolism. The first chapter of this thesis provides an introduction to metabolomics and an overview of the protocols for sample preparation, data collection and statistical analysis. The second thesis chapter describes in explicit detail the step-by-step process of extracting and analyzing metabolites collected from mammalian cells, specifically brain tissue with a focus on Parkinson’s disease. The chapter highlights important …