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2014

Modeling

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Articles 1 - 12 of 12

Full-Text Articles in Life Sciences

Management Of Channel Catfish Ictalurus Punctatus In The Missouri River, Nebraska, Brandon L. Eder Dec 2014

Management Of Channel Catfish Ictalurus Punctatus In The Missouri River, Nebraska, Brandon L. Eder

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

The popularity of catfish Ictaluridae nationally as a sport fish is well documented and angling for catfish on the Missouri River in Nebraska (NMR) is especially popular. Catfish monitoring program by the Nebraska Game and Parks Commission (NGPC) began in 1974 and several short-term evaluations of Channel Catfish population dynamics have been performed. However, no long term analyses of population characteristics have been conducted since the early 1990s. The focus of this research was to summarize the status of Channel Catfish populations in the NMR and give recommendations for future management. I summarized population characteristics, modeled length limit regulations, and …

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An Activity Aimed At Improving Student Explanations Of Biological Mechanisms, Caleb M. Trujillo, Trevor R. Anderson, Nancy J. Pelaez Dec 2014

An Activity Aimed At Improving Student Explanations Of Biological Mechanisms, Caleb M. Trujillo, Trevor R. Anderson, Nancy J. Pelaez

PIBERG Instructional Innovation Materials

This document is intended for use by instructors and their students. The activity contains steps to introduce students to the MACH model involving analyzing and discussing explanations about biological mechanisms. Initially, students read modified articles about biological mechanisms during class, although instructors may prefer to assign readings outside of class before the activity. During the activity, students are required to analyze the readings for evidence of research methods, analogies, context, and mechanisms. In so doing, students learn how to integrate the information pertaining to each of the MACH model components into a coherent explanation about their biological mechanism. After performing …

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A Tetrahedral Version Of The Mach Model For Explaining Biological Mechanisms, Caleb M. Trujillo, Trevor R. Anderson, Nancy J. Pelaez Dec 2014

A Tetrahedral Version Of The Mach Model For Explaining Biological Mechanisms, Caleb M. Trujillo, Trevor R. Anderson, Nancy J. Pelaez

PIBERG Instructional Innovation Materials

This document is intended for both instructors and students. Modified from the original MACH model this version, once cut and folded, creates a tetrahedral model that can conveniently be used as a teaching and learning tool to inform and guide students on how to write expert quality explanations of biological mechanisms. Each vertex of the tetrahedron represents a component of the model namely, Methods, Analogy, Context, and How. For a coherent and complete explanation about molecular mechanisms, it is important to integrate information pertaining to all four components of the model. The tetrahedral MACH model has been tested in both …

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Physiological Models Of Geobacter Sulfurreducens And Desulfobacter Postgatei To Understand Uranium Remediation In Subsurface Systems, Roberto Orellana Nov 2014

Physiological Models Of Geobacter Sulfurreducens And Desulfobacter Postgatei To Understand Uranium Remediation In Subsurface Systems, Roberto Orellana

Doctoral Dissertations

Geobacter species are often the predominant Fe(III)-reducing microorganisms in many sedimentary environments due to their capacity for extracellular electron transfer. This exceptional physiological capability allows them to couple acetate oxidation to uranium (U(VI)) reduction, that is one of the most significant interactions between radionuclides and microorganisms that naturally takes place in uranium-contaminated environments. Although this process has been proposed as a promising strategy for the in situ bioremediation of uranium-contaminated groundwater, little is known about the molecular mechanisms involved in U(VI) reduction and the interaction between Geobacter and other microbial species. In the first two research chapters, this dissertation aim …

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Modeling Sleep And Wake Bouts In Drosophila Melanogaster, Gayla R. Olbricht, V. A. Samaranayake, Sahitya Injamuri, Luyang Wang, Courtney Fiebelman, Matthew S. Thimgan Apr 2014

Modeling Sleep And Wake Bouts In Drosophila Melanogaster, Gayla R. Olbricht, V. A. Samaranayake, Sahitya Injamuri, Luyang Wang, Courtney Fiebelman, Matthew S. Thimgan

Conference on Applied Statistics in Agriculture

Adequate sleep restores vital processes required for health and well-being; but the function and regulation of sleep is not well understood. Unfortunately, a definition of adequate sleep is unclear. On an hours-long timescale, consolidated and cycling sleep results in better health and performance outcomes. At shorter timescales, older studies report conflicting results regarding the relationship between sleep and wake bout durations. One approach to this problem has been to simply analyze the distribution of bout durations. While informative, this method eliminates the time relationship between bouts, which may be important. Here, we develop a model that describes the relationship between …

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Application Of An Imputation Method For Geospatial Inventory Of Forest Structural Attributes Across Multiple Spatial Scales In The Lake States, U.S.A., Ram K. Deo Jan 2014

Application Of An Imputation Method For Geospatial Inventory Of Forest Structural Attributes Across Multiple Spatial Scales In The Lake States, U.S.A., Ram K. Deo

Dissertations, Master's Theses and Master's Reports - Open

Credible spatial information characterizing the structure and site quality of forests is critical to sustainable forest management and planning, especially given the increasing demands and threats to forest products and services. Forest managers and planners are required to evaluate forest conditions over a broad range of scales, contingent on operational or reporting requirements. Traditionally, forest inventory estimates are generated via a design-based approach that involves generalizing sample plot measurements to characterize an unknown population across a larger area of interest. However, field plot measurements are costly and as a consequence spatial coverage is limited. Remote sensing technologies have shown remarkable …

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Numerical Algorithms For Solving A Generalized Cancer Chemotherapy Problem, Frank Nani, Mingxian Jin Jan 2014

Numerical Algorithms For Solving A Generalized Cancer Chemotherapy Problem, Frank Nani, Mingxian Jin

Math and Computer Science Faculty Working Papers

In this paper, two elaborate numerical algorithms are presented for solving the Nani- Oguztoreli functional differential equations associated with cell-cycle specific cancer chemotherapy. The generalized cell-cycle specific cancer chemotherapy model of Nani- Oguztoreli contains discrete time delays which represent the times that the cancer cells spend in each cell-cycle phase. The model also takes into account that inter-cell cycle phase transition rate constants, recruitment of resting cells from the GO phase, and effect of chemotherapy drug on cells in each phase. The algorithms utilize a modified version of the Method of Steps algorithms. The constructed numerical schemes can be implemented …

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On The Challenges Of Modeling The Net Radiative Forcing Of Wetlands: Reconsidering Mitsch Et Al. 2013, Scott C. Neubauer Jan 2014

On The Challenges Of Modeling The Net Radiative Forcing Of Wetlands: Reconsidering Mitsch Et Al. 2013, Scott C. Neubauer

Biology Publications

Wetlands play a role in regulating global climate by removing carbon dioxide (CO2) from the atmosphere and sequestering it as soil carbon, and by emitting methane (CH4) and nitrous oxide (N2O) to the atmosphere. In a recent article in this journal (Mitsch et al. Landscape Ecol 28:583–597, 2013), CO2 sequestration and CH4 emissions were modeled for several freshwater wetlands that vary in vegetation type, climate, and hydrology. The authors of that study made significant errors that caused them to underestimate the importance of wetland CH4 emissions on climate dynamics. Here, I reanalyze the Mitsch et al. dataset and show that …

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Methodological Advancements For Improving Performance And Generating Ensemble Ecological Niche Models, Robert Boria Jan 2014

Methodological Advancements For Improving Performance And Generating Ensemble Ecological Niche Models, Robert Boria

Dissertations and Theses

This study employs spatial filtering of occurrence data with the aim of reducing overfitting to sampling bias in ecological niche models (ENMs). Sampling bias in geographic space leads to localities that may also be biased in environmental space. If so, the model can overfit to those biases. As a preliminary test addressing this issue, we used Maxent, bioclimatic variables, and occurrence localities of a broadly distributed Malagasy tenrec, Microgale cowani (Family Tenrecidae: Subfamily Oryzorictinae). We modeled the abiotically suitable area of this species using three distinct datasets: unfiltered, spatially filtered, and rarefied unfiltered localities. To quantify overfitting and model performance, …

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Modeling Consumption Rates Of Atlantic Herring (Clupea Harengus), Mitchell Jones Jan 2014

Modeling Consumption Rates Of Atlantic Herring (Clupea Harengus), Mitchell Jones

Graduate College Dissertations and Theses

Pelagic forage fishes play critical roles in productive marine food webs by providing a link between zooplankton and piscivores and transferring energy from feeding grounds to other ecosystems. The amount of energy moved to higher trophic levels or new systems is directly linked to the consumption rate of pelagic forage fishes. In the Gulf of Maine, Atlantic herring (Clupea harengus) is the dominant forage fish; the purpose of this study is to determine their specific consumption rate (g prey/g fish/day). Using fish collected in autumn 2012 and spring 2013, we applied a mercury mass-balance model to estimate individual …

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Testing A Structural Equation Model Of Language-Based Cognitive Fitness, Elizabeth Ann Moxley-Paquette Jan 2014

Testing A Structural Equation Model Of Language-Based Cognitive Fitness, Elizabeth Ann Moxley-Paquette

Walden Dissertations and Doctoral Studies

The normative development of language is often taken for granted, yet problems with language development can result in stress for the individual and family. A challenge with these language development problems lies within the contemporary education system, which assumes that children have appropriate skills when they begin school. The purpose of the study was to test a theoretical model of language readiness known as language-based cognitive fitness, which includes measures associated with structural concepts of language involving receptive language, expressive language, spontaneous narrative speech, and writing fluency. The sample included children from a private school who received an extensive battery …

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Exploring How Middle School Students' Epistemologies In Practice Change Across Time With Varying Content Areas And Knowledge Product Contexts, Mackenzie Evan English Jan 2014

Exploring How Middle School Students' Epistemologies In Practice Change Across Time With Varying Content Areas And Knowledge Product Contexts, Mackenzie Evan English

Browse all Theses and Dissertations

Recently, the National Research Council developed A Framework for K-12 Science Education (NRC, 2012), to support a new vision of science education. The Framework (2012) focuses on three integrated dimensions--disciplinary core ideas, crosscutting concepts, and scientific and engineering practices which is different than traditional ways of learning science. I focused on students' engagement in scientific practices, attention to epistemological practices (EIP) that guide students' construction, evaluation and revision of knowledge products. I examined how students EIP's changed over time and across contexts with respect to different knowledge product types (models and explanations). I present data from 103, 6th grade students …

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