Physical Sciences and Mathematics Commons^™

The Influence Of Framing And Recent Experience On Farmer Choices In Experimental Games Depicting Risk-Reducing Agricultural Technologies, Ana Maria Ospina Tobar

Electronic Theses and Dissertations

Climate change is a major threat to food security, particularly in low and middle-income countries that are highly dependent on staple crops for subsistence. The vulnerability of staple crops, like maize, in the face of climate change, is increasing due to the increasing frequency of droughts. This thesis aims to evaluate two mechanisms through which farmers may be more willing to adopt new technologies that increase their resilience to climate change: First, I evaluate the effectiveness of a new virtual maize farming game as a learning tool to teach farmers about the outcomes they could obtain under different weather events …

Developing An Enhanced Forest Inventory In Maine Using Airborne Laser Scanning: The Role Of Calibration Plot Design And Data Quality, Stephanie Willsey

Electronic Theses and Dissertations

Forests provide essential ecosystem services such as carbon sequestration, clean water, lumber, and more. It is important that foresters be able to collect accurate forest inventories, especially in a changing climate. Foresters need to know what is in the forest not only to manage for the economic benefits, but also to manage for social acceptability and ecological soundness to prevent further degradation of these ecosystem services. One way to collect accurate and precise forest inventories is through the utilization of remote sensing products. These enhanced forest inventories (EFIs) can be done at varying resolutions that are contingent on the plot …

Factors Affecting Apothecia Production And Primary Infection By Monilinia Vaccinii-Corymbosi On Vaccinium Angustifolium, Ian Leonard

Electronic Theses and Dissertations

Mummy berry, caused by Monilinia vaccinii-corymbosi (MVC), is a prolific disease of Vaccinium angustifolium (wild blueberry) leading to decreased yield in wild blueberry fields throughout the Downeast (DE) and Midcoast (MC) regions of Maine (ME). This study aimed to identify factors affecting primary inoculum production and infection by MVC on wild blueberry, and what bud stages of wild blueberry are most susceptible to infection. Through common garden (CGE), field and incubation experiments conducted in 2021 and 2022, factors affecting carpogenic germination of MVC pseudosclerotia and relationships between susceptible wild blueberry buds and environmental factors were analyzed. The CGE conducted in …

An Analysis Of Changes In Seasonal Dynamics And Generational Differences In The Maine Lobster Fishery, Emily Fitting

Electronic Theses and Dissertations

The American lobster (Homarus americanus) supports the most valuable single species fishery in the US. Lobster landings have been increasing steadily for the last three decades, but before that landings were more variable. The high value of the lobster fishery combined with the decline of other commercially important species in this region has created increasing dependence on the resource, and previous research questions the resilience of the fishery in the face of social and environmental changes.

Important lobster life history processes, including migration patterns, growth rates, and reproduction, are driven by ocean bottom temperature, which creates a strong seasonal cycle …

First-Year Computer Science Students: Pathways And Perceptions In Introductory Computer Science Courses, Christina A. Leblanc

Electronic Theses and Dissertations

This study examined student perceptions and experiences of an introductory Computer Science course at the University of Maine; COS 125: Introduction to Problem Solving Using Computer Programs. It also explored the pathways that students pursue after taking COS 125, depending on their success in the course, and their motivation to persist. Through characterizing student populations and their performance in their first semester in the Computer Science program, they can be placed into one of three categories that explain their path; a “continuer” (passed COS 125 and decided to stay in the major), a “persister” (did not pass COS 125 and …

An Epidemiological Model With Simultaneous Recoveries, Ariel B. Farber

Electronic Theses and Dissertations

Epidemiological models are an essential tool in understanding how infection spreads throughout a population. Exploring the effects of varying parameters provides insight into the driving forces of an outbreak. In this thesis, an SIS (susceptible-infectious-susceptible) model is built partnering simulation methods, differential equations, and transition matrices with the intent to describe how simultaneous recoveries influence the spread of a disease in a well-mixed population. Individuals in the model transition between only two states; an individual is either susceptible — able to be infected, or infectious — able to infect others. Events in this model (infections and recoveries) occur by way …

Paper Structure Formation Simulation, Tyler R. Seekins

Electronic Theses and Dissertations

On the surface, paper appears simple, but closer inspection yields a rich collection of chaotic dynamics and random variables. Predictive simulation of paper product properties is desirable for screening candidate experiments and optimizing recipes but existing models are inadequate for practical use. We present a novel structure simulation and generation system designed to narrow the gap between mathematical model and practical prediction. Realistic inputs to the system are preserved as randomly distributed variables. Rapid fiber placement (~1 second/fiber) is achieved with probabilistic approximation of chaotic fluid dynamics and minimization of potential energy to determine flexible fiber conformations. Resulting digital packed …

Blacklegged Tick (Ixodes Scapularis) Distribution In Maine, Usa, As Related To Climate Change, White-Tailed Deer, And The Landscape, Susan P. Elias

Electronic Theses and Dissertations

Lyme disease is caused by the bacterial spirochete Borrelia burgdorferi, which is transmitted through the bite of an infected blacklegged (deer) tick (Ixodes scapularis). Geographic invasion of I. scapularis in North America has been attributed to causes including 20th century reforestation and suburbanization, burgeoning populations of the white-tailed deer (Odocoileus virginianus) which is the primary reproductive host of I. scapularis, tick-associated non-native plant invasions, and climate change. Maine, USA, is a high Lyme disease incidence state, with a history of increasing I. scapularis abundance and northward range expansion. This thesis addresses the question: “To …

Spatio-Temporal Dynamics Of Atlantic Cod Bycatch In The Maine Lobster Fishery And Its Impacts On Stock Assessment, Robert E. Boenish

Electronic Theses and Dissertations

Of the most iconic fish species in the world, the Atlantic cod (Gadus morhua, hereafter, cod) has been a mainstay in the North Atlantic for centuries. While many global fish stocks have received increased pressure with the advent of new, more efficient fishing technology in the mid-20^th century, exceptional pressure has been placed on this prized gadoid. Bycatch, or the unintended catch of organisms, is one of the biggest global fisheries issues. Directly resulting from the failed recovery of cod in the GoM, attention has been placed as to possible sources of unaccounted catch. Among the most …

Cellulose Nanofiber-Reinforced Impact Modified Polypropylene: Assessing Material Properties From Fused Layer Modeling And Injection Molding Processing, Jordan Elliott Sanders

Electronic Theses and Dissertations

The purpose of this research was to investigate the use of cellulose nanofibers (CNF) compounded into an impact modified polypropylene (IMPP) matrix. A IMPP was used because it shrinks less than a PP homopolymer during FLM processing. An assessment of material properties from fused layer modeling (FLM), an additive manufacturing (AM) method, and injection molding (IM) was conducted. Results showed that material property measurements in neat PP were statistically similar between IM and FLM for density, strain at yield and flexural stiffness. Additionally, PP plus the coupling agent maleic anhydride (MA) showed statistically similar results in comparison of IM and …

Using Hydroacoustics To Investigate Biological Responses In Fish Abundance To Restoration Efforts In The Penobscot River, Maine, Constantin C. Scherelis

Electronic Theses and Dissertations

Spatiotemporal advantages linked to hydroacoustic sampling techniques have caused a surge in the use of these techniques for fisheries monitoring studies applied over long periods of time in marine systems. Dynamic physical conditions such as tidal height, boat traffic, floating debris, and suspended particle concentrations result in unwanted noise signatures that vary in intensity and location within a hydroacoustic beam over time and can be mixed with the acoustic returns from intended targets (e.g., fish). Typical processing filters applied over long term datasets to minimize noise and maximize signals do not address spatiotemporal fluctuations of noise in dynamic systems. We …

Topographic Signatures Of Geodynamics, Samuel G. Roy

Electronic Theses and Dissertations

The surface of the Earth retains an imperfect memory of the diverse geodynamic, climatic, and surface transport processes that cooperatively drive the evolution of Earth. In this thesis I explore the potential of using topographic analysis and landscape evolution models to unlock past and/or present evidence for geodynamic activity. I explore the potential isolated effects of geodynamics on landscape evolution, particularly focusing on two byproducts of tectonic strain: rock displacement and damage. Field evidence supports a strong correlation between rock damage and erodibility, and a numerical sensitivity analysis supports the hypothesis that an order of magnitude weakening in rock, well …

Individual Tree Measurements From Three-Dimensional Point Clouds, Elias Ayrey

Electronic Theses and Dissertations

This study develops and tests novel methodologies for measuring the attributes of individual trees from three-dimensional point clouds generated from an aerial platform. Recently, advancements in technology have allowed for the acquisition of very high resolution three-dimensional point clouds that can be used to map the forest in a virtual environment. These point clouds can be interpreted to produce valuable forest attributes across entire landscapes with minimal field labor, which can then aid forest managers in their planning and decision making.

Biometrics derived from point clouds are often generated on a plot level, with estimates spanning many meters (rather than …

Application Of The Rasch Model To Measure Five Dimensions Of Wellness In Community-Dwelling Older Adults, Kelley A. Strout Dr

Nursing Faculty Scholarship

Background and Purpose: Nurse researchers and practicing nurses need reliable and valid instruments to measure key clinical concepts. The purpose of this research was to develop an innovative method to measure dimensions of wellness among older adults. Method: A sample of 5,604 community-dwelling older adults was drawn from members of the COLLAGE consortium. The Wellness Assessment Tool (WEL) of the COLLAGE assessment system provided the data used to create the scores. Application of the Rasch analysis and Masters' partial credit method resulted in logit values for each item within the five dimensions of wellness as well as logit values for …

Bayesian Analysis Of Data On Nest Success For Marsh Birds, Sean Hardy

Honors College

Bayesian methods are an increasingly popular form of statistical analysis which uses informative prior distributions to help calculate posterior distributions of models that represent different hypotheses. Frequentist methods are contrasting methods that are used more commonly and more well known, but have come under recent criticism. I examined data gathered by Ellen Robertson, who used information theoretic methods for a Masters’ Thesis in Ecology and Environmental Science at the University of Maine to analyze the daily survival probabilities of marsh birds with a Bayesian perspective in order to get a sense of the Bayesian analysis. Results were as expected; when …

Testing The Predictive Performance Of Distribution Models, Volker Bahn, Brian Mcgill

Publications

Distribution models are used to predict the likelihood of occurrence or abundance of a species at locations where census data are not available. An integral part of modelling is the testing of model performance. We compared different schemes and measures for testing model performance using 79 species from the North American Breeding Bird Survey. The four testing schemes we compared featured increasing independence between test and training data: resubstitution, random data hold-out and two spatially segregated data hold-out designs. The different testing measures also addressed different levels of information content in the dependent variable: regression R2 for absolute abundance, squared …

Mri: Acquisition Of Interactive Visualization Tools For Supercomputer Models, Bruce E. Segee, Huijie Xue, Kiran Bhaganagar, James Fastook, Peter O. Koons

University of Maine Office of Research Administration: Grant Reports

This project, acquiring a visualization facility (vizwall with high resolution display and high volume storage system to visualize large size data generated from diverse research activities), models polar ice sheets, oceans, atmospheric turbulent boundary layers, and geodynamics. The facility, whose main components consist of a visualization wall, a PRISM visualization server, and RAID storage disks, will be integrated to the university's existing supercomputer cluster.

Cmg Training In Spatio-Temporal Statistical Analysis Of Multi-Platform Ocean Optical Observations, Mary Jane Perry

University of Maine Office of Research Administration: Grant Reports

This project will be a five-week summer school on the topic of spatio-temporal statistical analysis and its application to multi-platform, multi-sensor bio-optical oceanic data. The summer school seeks to address some of the analysis challenges anticipated as the Integrated Ocean Observing System is established. These are associated with the very diverse range of spatial and temporal sampling afforded by the different components of such a system and contemporaneous process experiments. Statistical experts in spatial information engineering with experience in collaboration with ocean scientists will discuss some of the modern tools for statistical analysis of such data and associated challenges, while …

Discovering Properties Of Complex Numbers By Starting With Known Properties Of Real Numbers, Esther D. Hatch

Honors College

No abstract provided.

Estimation Of Standardized Mortality Ratio In Epidemiological Studies, Bingxia Wang

Electronic Theses and Dissertations

In epidemiological studies, we are often interested in comparing the mortality rate of a certain cohort to that of a standard population. A standard computational statistic in this regard is the Standardized Mortality Ratio (SMR) @reslow and Day, 1987), given by where 0 is the number of deaths observed in the study cohort from a specified cause, E is the expected number calculated from that population. In occupational epidemiology, the SMR is the most common measure of risk. It is a comparative statistic. It is frequently based on a comparison of the number0 in the cohort with the expected value …

Hierarchical Modeling For Integrated Environmental Assessments, Raymond O'Connor, Deidre Mageean

University of Maine Office of Research Administration: Grant Reports

The distribution of biotic resources over large spatial extents is often a function of climate, of land-use, and of the demographics of the human population but these different classes of independent variables have different spatial scales for their action. One approach to the integration of these effects across scales is to use hierarchical models that incorporate contingencies and constraints in effects. This project seeks to develop such a modeling paradigm by use of classification and regression trees (CART). The hexagonal grid of the U.S. Environmental Protection Agency's Environmental Monitoring and Assessment Program is used as the spatial grid, with about …

Reliability Studies Of The Skew Normal Distribution, Nicole Dawn Brown

Electronic Theses and Dissertations

It has been observed in various practical applications that data do not conform to the normal distribution, which is symmetric with no skewness. The skew normal distribution proposed by Azzalini(1985) is appropriate for the analysis of data which is unimodal but exhibits some skewness. The skew normal distribution includes the normal distribution as a special case where the skewness parameter is zero. In this thesis, we study the structural properties of the skew normal distribution, with an emphasis on the reliability properties of the model. More specifically, we obtain the failure rate, the mean residual life function, and the reliability …

Dickey-Lincoln School Lakes Project Environmental Impact Statement: Appendix F: Terrestrial Ecosystem Analysis (Supplement 2), University Of Maine At Orono, Maine, Cooperative Wildlife Research Unit, United States Army Engineer Division, New England Division

Dickey-Lincoln School Lakes Project

The overall study area encompassed the St. John River and its major tributaries; including the Little and Big Black Rivers (and their tributaries); and all lands extending 3.2 km (2 mi) beyond the maximum elevation of thv predicted impoundment of the Dickey Dam (1,560 km ). Research was concentra-ted in a portion of this area roughly bounded on the north by Chimenticook Stream, on the east by the St. John River, on the west by the United States-Canadian border, and on the south by a line drawn east-west through Seven Islands (Figure 1.0-1). Intensive marten studies were restricted to townships …

Dickey-Lincoln School Lakes Project At Dickey, Maine : Final Environmental Impact Statement, New England Division, United States Army Engineer Division

Dickey-Lincoln School Lakes Project

The Final Impact Statement is supported by all appendices from all drafts as well as supplementary information provided in Supplements to those Appendices. It comprises three volumes. Volume I is the statement volume. Volume II consists of two parts. Part I contains the comment and response portion of Section 9 for the 1977 Draft EIS. Part II contains comments and responses on the 1978 Revised Draft EIS, in addition to reproductions of the original comment letters received on the Draft Fish and Wildlife Mitigation Report and responses to these comments. Volume III, Part I contains reproductions of the original comment …

Dickey-Lincoln School Lakes Transmission Project: Final Environmental Impact Statement: Appendix L, New England Division, United States Army Corps Of Engineers, United States Department Of Energy

Dickey-Lincoln School Lakes Project

This draft EIS Supplement describes the environmental impacts of updated transmission plans of the Department of Energy (DOE) for the proposed Dickey-Lincoln School Lakes Project. Energy produced by the project is to be integrated into the New England electric system if the project is constructed.

Dickey-Lincoln School Lakes Project At Dickey, Maine : Final Environmental Statement, Volume 1-4, U. S. Army Engineer Division, New England

Dickey-Lincoln School Lakes Project

The proposed Dickey-Lincoln School Lakes Project in northern Maine is a multipurpose installation on the St.John River. The combination hydroelectric power and flood control project is located in Aroostook County, Maine, near the Canadian border. The two proposed earth fill dams located at Dickey are 10,200 feet in length with a maximum height of 335 feet. They would impound 7.7 million acre feet of water at a maximum pool elevation 910 feet mean sea level. A second earth filled dam located 11 miles downstream at Lincoln School would serve as a regulatory dam. It would be 2100 feet in lenqth, …

Dickey-Lincoln School Lakes Project Environmental Impact Statement: Appendix K: Fish & Wildlife Mitigation Plan & Impacts (Revised), New England Division, United States Army Engineer Division

Dickey-Lincoln School Lakes Project

The proposed plan is comprised of three major segments: terrestrial, fisheries and endangered species. Each segment is essentially a self-contained unit. All costs for the three segments including land acquisition, operation and maintenance and capital equipment, are to be charged to the project and allocated to the project purposes of hydroelectric generation and flood control.

Federal Water Pollution Control Act Section "404" Evaluation For Dickey-Lincoln School Lakes, New England Division, United States Army Engineer Division, United States Army Corps Of Engineers

Dickey-Lincoln School Lakes Project

The purpose of this report is to relate various aspects of the proposed Dickey-Lincoln School Lakes Hydroelectric Project to appropriate considerations defined by Section 404 of the Federal Water Pollution Control Act of 1972.

Dickey-Lincoln School Lakes Project Environmental Impact Statement: Appendix A: Geology And Seismology (Supplement), Walter A. Anderson, New England Division, United States Army Engineer Division

Dickey-Lincoln School Lakes Project

The plan was prepared for a close working relationship between the evaluation teams and the immediate availability of geochemical and geophysical data to the geologic mapping team. Those samples determined in the field to be anomalously high in heavy metals by cold extractable procedures were sent to North American Laboratories where metal content determinations were made through: atomic absorption and spectrophotometry after hot acid digestion techniques.

Fish And Wildlife Mitigation Report : Dickey-Lincoln School Lakes Project, Maine, New England Division, Corps Of Engineers, U. S. Army Engineer Division

Dickey-Lincoln School Lakes Project

The Dickey Lincoln School Lakes Project is a proposed multipurpose project located on the upper reaches of the St. John River in Aroostook County, Maine. Development would consist of two dams with associated reservoirs and hydroelectric generating facilities, five dikes and transmission lines. A more detailed description of the proposed project and its associated impacts is contained within the Revised Draft Environmental Impact Statement for the proposed project.