Digital Commons Network^™

Specific Dynamic Action, Growth And Development In Larval Atlantic Cod, Gadus Morhua, Jessica A. Geubtner

Electronic Theses and Dissertations

The larval stage of marine fish is a period of rapid growth and development. Atlantic cod (Gadus morhua) are approximately 4-5 rnm in length upon hatch and feed endogenously from their yolk sac for the first week. After this time, larval cod must successfully capture live prey to survive and to fuel high growth rates of greater than 10%d". Previous studies have found that during exogenous feeding and at growth rates greater than 8%d1 larvae experience what appears to be cost free growth, where mass specific metabolic rate does not decrease with increasing mass. Due to size and condition constraints …

An Egocentric Spatial Data Model For Intelligent Mobile Geographic Information Systems, Christopher E. Frank

Electronic Theses and Dissertations

Individuals in unknown locations, such as utility workers in the field, soldiers on a mission, or sightseeing tourists, share the need for an answer to two basic questions: "Where am I?" and "What is in front of me?Because such information is not readily available in foreign locations, aids in the form of paper maps or mobile GISs, which give individuals an all-inclusive view of the environment, are often used. This panoptic view may hinder the positioning and orienteering process, since people perceive their surroundings perspectively from their current position. In this thesis, I describe a novel framework that resolves this …

Query-By-Pointing: Algorithms And Pointing Error Compensation, Farhan Faisal

Electronic Theses and Dissertations

People typically communicate by pointing, talking, sketching, writing, and typing. Pointing can be used to visualize or exchange information about an object when there is no other mutually understood way of communication. Despite its proven expressiveness, however, it has not yet become a frequently used modality to interact with computer systems. With the rapid move towards the adoption of mobile technologies, geographic information systems (GISs) have a particular need for advanced forms of interaction that enable users to query the geographic world directly. To enable pointing-based query system on a handheld device, a number of fundamental technical challenges have to …

The Role Of Larval Thermal Tolerance In The Distribution Of Blue Mussel Species Within The Gulf Of Maine, Susan J. Limbeck

Electronic Theses and Dissertations

Two species of blue mussel, Myrilus edulis and Myrilus trossulus, are sympatric throughout much of the Canadian Maritime Provinces and into the Gulf of Maine. While the distribution of M edulis extends south to the Mid-Atlantic, that of M. trossulus ends abruptly in the Gulf of Maine. I have hypothesized that these differences in adult distribution are the result of species-specific variation in larval thermal tolerances. Previously, it has been shown that when reared at 20 OC, from 36 hour post-fertilization through settlement, M. trossulus had significantly higher mortality rates than M. edulis. This study examined whether species-specific differences in …

Analysis Of The Spatial Dynamics Of The American Lobster (Homarus Americanus) Fishery Along The Coast Of Maine, Kevin M. Scheirer

Electronic Theses and Dissertations

The American lobster (Homarus americanus) supports the most valuable commercial fishery in the northeastern United States, thus the fishery is critical to Maine's economy. No systematic study has been done to collect information about, identify, and quantify the spatial dynamics of the Maine lobster fishery. This project helps to provide a better understanding of Maine's lobster fishery dynamics, and it will aid f'iture efforts to improve the stock assessment of Maine's lobster fishery. The analysis consists of three distinct parts: (1) comparison of data collected by two separate fishery dependent sampling programs; (2) spatial analysis of electronic logbook data; and …

Mechanistic Studies Of The Oxidation Of Lignin And Cellulose Models, Oh-Kyu Lee

Electronic Theses and Dissertations

Oxygen delignification is an environmentally friendly pulp bleaching system. To develop a selective delignification process that results in high DP retention of carbohydrate with lignin being removed, obtaining better knowledge of reactions occurring during oxygen delignification is essential.

In this work, mixtures of guaiacol (model lignin) and methyl-ß-D-glucoside (model cellulose) were reacted in a pressurized oxygen reaction system (pH 12,65 psi O₂, and 95°C in a glass reaction vessel). In the results, methyl-ß-D-glucoside degraded only in the presence of lignin. This indicates that hydroxyl radicals, that subsequently react with methyl-ß-D-glucoside, are generated in the system. Unfortunately, we could …

Development And Assessment Of A Spatial Decision Support System For Conservation Planning, Sean Murphy

Electronic Theses and Dissertations

Land conservation is frequently cited as the most effective means of limiting the detrimental effects of anthropogenic forces on natural resources. Because governmental entities can be hampered by fiscal and political concerns, land trusts are increasing relied on to protect habitat. However, these groups often lack the analysis and research tools necessary to meet their mission. Geographic Information System (GIs) technologies such as Spatial Decision Support Systems (SDSS) offer the promise of allowing decision makers to explore their decision space at a landscape level of analysis. But critics have charged that research in this arena is largely anecdotal in nature. …

Pond-Breeding Amphibian Species Distributions In A Beaver-Modified Landscape, Acadia National Park, Mount Desert Island, Maine, Jesse Cunningham

Electronic Theses and Dissertations

In order to maintain pond-breeding amphibian species richness, it is important to understand how both natural and anthropogenic disturbances affect species assemblages and individual species distributions both at the scale of individual ponds and at a larger landscape scale. The goal of this project was to investigate what characteristics of ponds and the surrounding wetland landscape were most effective in predicting pond-breeding species richness and the individual occurrence of wood frog (Rana sylvatica), bullfrog (Rana catesbeiana) and pickerel frog (Rana palustris) breeding sites in a beaver-modified landscape and how this landscape has changed over …

A Mass Balance Study Of The West Antarctic Ice Sheet, Vandy Blue Spikes

Electronic Theses and Dissertations

The present state of the West Antarctic ice sheet (WAIS) is a prime concern of science, but its large size and remote location have limited the amount of reliable data that are available for mass balance calculations. The spatial pattern of mass balance for a 100-km² portion of the WAIS is estimated by calculating the residual flux of ice through 1-km grid cells organized into a geographical information system (GIs). The input data used for this estimate include continent-scale compilations of ice thickness and snow accumulation rate measurements, and ground-based measurements of snow accumulation rate and ice velocity. The …

An Investigation Of The Cumulative Impacts Of Shrimp Trawling On Mud Bottom Fishing Grounds In The Gulf Of Maine: Effects On Habitat And Macrofaunal Community Structure, Anne W. Simpson

Electronic Theses and Dissertations

Despite the widespread occurrence of trawl fisheries on mud-bottoms, there is limited knowledge concerning the effects of trawling induced disturbance on these habitats and their resident macrofaunal communities. I investigated the cumulative impacts of seasonal commercial shrimp trawling on infaunal habitat and macrofaunal community structure on two mud-bottom fishing grounds in the Gulf of Maine from June 2000 - December 2001. One fishing ground located near the Outer Pumpkin Ledges (Pumpkin) experienced trawling activity during the 2000-2001 fishing season. In contrast, the other fishing ground near Monhegan Island was not trawled during the same period because shrimp abundances were low. …

A Comparison Of The Ecological Integrity Of Headwater Streams Draining Harvested And Un-Harvested Watersheds In The Western Mountains Of Maine, U.S.A., Darlene Siegel

Electronic Theses and Dissertations

Physical, chemical, and biological characteristics of four headwater streams draining forested watersheds were compared to determine the effectiveness of Riparian Management Zones (RMZs) in protecting aquatic ecological integrity from the effects of forest harvesting. Two of the watersheds were harvested with a 30% sheltenvood cut and a 75 foot buffer was left adjacent to the streams. The other two watersheds were un-harvested and were used as reference conditions for comparison with the harvested watersheds. General environmental conditions in these four headwater streams during the study period were characterized as follows. Each stream was located within a mixed- wood forest dominated …

The Effects Of The 2001-2002 Drought On Maine Surface Water Supplies, Catherine Schmitt

Electronic Theses and Dissertations

Maine lakes and streams serve as significant sources of public water supply, serving 40% of the population. Drought affects surface water resources by reducing water quantity and altering water quality, for example by reducing inputs of materials from the watershed and increasing water residence times. The 2001-2002 drought was the worst in Maine in over thirty years, and it exposed deficiencies in current water resources planning and management. In this study, I evaluated the effects of the 2001-2002 drought on Maine public water systems in order to identify characteristics of systems vulnerable to drought and determine appropriate indicators of drought …

Perceptual Sketch Interpretation, Markus Wuersch

Electronic Theses and Dissertations

Sketching is a creative form of describing a spatial scene. People perceive such a scene in a straight forward way and build a mental model of the objects contained in a sketch. Whereas these objects might be regions, a sketch only contains lines and, therefore, developing automated sketch interpretation means outlining a rationale to grouping lines according to the objects they belong to. Automated sketch interpretation allows efficient processing of sketches. Labor intensive manual extraction could be brought to a minimum and, therefore, spatial data in form of sketches and spatial information extracted from sketches would be available more readily. …

Public Commons For Geospatial Data: A Conceptual Model, Chakravarthy Namindi Sharad

Electronic Theses and Dissertations

A wide variety of spatial data collection efforts are ongoing throughout local, state and federal agencies, private firms and non-profit organizations. Each effort is established for a different purpose but organizations and individuals often collect and maintain the same or similar information. The United States federal government has undertaken many initiatives such as the National Spatial Data Infrastructure, the National Map and Geospatial One-Stop to reduce duplicative spatial data collection and promote the coordinated use, sharing, and dissemination of spatial data nationwide. A key premise in most of these initiatives is that no national government will be able to gather …

The Characteristics That Control The Stability Of Eroding Coastal Bluffs In Maine, Corinn C. Keblinsky

Electronic Theses and Dissertations

Bluffs of glacigenic sediment exist along 53% of the tidal shoreline of Maine. Under the current regime of rising sea level, waves, groundwater, and sub-aerial processes easily erode these materials. The hazardous nature of the bluffs is not widely recognized by the public, and new homeowners are often shocked to find out that their property is disappearing. To better educate the public, the Maine Geological Survey is mapping the stability of coastal bluffs. This report utilizes that database along with other available data to determine what controls the relative stability of bluffs. A geographic information system (GIs) was used to …

Resilience Of Green Sea Urchin (Strongylocentrotus Droebachiensis) Populations Following Fishing Mortality: Marine Protected Areas, Alternate Stable States, And Larval Ecology, John Vavrinec Iii

Electronic Theses and Dissertations

The green sea urchin Strongylocentrotus droebachiensis has been aggressively fished in Maine since 1986 resulting in severe population declines throughout portions of the state. This research used Marine Protected Areas (MPAs) to evaluate the potential for recovery in depleted sea urchin populations. It was necessary to not only look at the direct impacts of the MPAs, but also at larval transport / supply and community interactions to gain a better understanding of the system. We found that MPAs in the Gulf of ~a!ne were of varied utility to restoring depleted sea urchin populations depending on location and community structure. MPAs …

Effects Of Fiberimatiux Interactions On The Interfacial Deformation Micromechanics Of Cellulose-Fiberipolymer Composites, William Tai-Yin Tze

Electronic Theses and Dissertations

The overall objective of this dissertation was to gain an understanding of the relationship between interfacial chemistry and the micromechanics of the cellulose-fiber/polymer composites. Regenerated cellulose (lyocell) fibers were treated with amine-, phenylamine-, phenyl-, and octadecyl-silanes, and also styrene-maleic anhydride copolymer. Inverse gas chromatography was conducted to evaluate the modified surfaces and to examine the adsorption behavior of ethylbenzene, a model compound for polystyrene, onto the fibers. Micro-composites were formed by depositing micro-droplets of polystyrene onto single fibers. The fiber was subjected to a tensile strain, and Raman spectroscopy was employed to determine the point-to-point variation of the strain- and …

Synthesis Of Porous Monoclinic Tungsten Oxides And Their Application In Sensors, Anil Bhalchandra Waghe

Electronic Theses and Dissertations

Semiconducting metal oxide sensors are limited in their usage because of their poor detection selectivity. The current approach to achieve better selectivity in SMO detection uses prefiltering/preconcentration schemes to reduce the number of gases in contact with the sensor in combination with array-based detection. In this thesis we have investigated different materials and approaches for use as elements in an array based detection system.

One approach we have investigated involves the use of porous monoclinic WO₃ to obtain size selectivity in detection within the sensing element itself. In chapter 3 we describe the synthetic protocol used to generate high …

Effects Of Nitrogen Deposition And Flow Permanence On Stream Organic Matter Dynamics, Michael Andrew Joseph Chadwick

Electronic Theses and Dissertations

The objective of this study was to investigate the effects of N enrichment and flow permanence on stream organic matter dynamics at the Bear Brook Watershed in Maine (BBWM). BBWM is a paired-catchment manipulation of atmospheric (NH₄)₂SO₄ deposition, and the goal of the experiment is to understand how increased N affects forested catchments. The treatment has increased stream nitrate and foliar N concentrations in the treatment watershed. Because streams draining BBWM are intermittent, this investigation provided an opportunity to investigate the combined effects of stream flow permanence and human alteration of N cycling in a …

User Controlled Privacy Protection In Location-Based Services, Anuket Bhaduri

Electronic Theses and Dissertations

The rapid development of location-determining technologies has enabled tracking of people or objects more accurately than ever before and the volume and extent of tracking has increased dramatically over time. Within the broader domain of tracking technologies, location-based services (LBS) are a subset of capabilities that allow users to access information relative to their own physical location. However, the personal location information generated by such technologies is at risk of being misused or abused unless protection capabilities are built into the design of such systems. These concerns may ultimately prevent society from achieving the broad range of benefits that otherwise …

Hydroperiod Of Wetlands And Reproduction In Wood Frogs (Rana Sylvatica) And Spotted Salamanders (Ambystoma Maculatum), Mary Beth Kolozsvary

Electronic Theses and Dissertations

Many amphibians rely on wetlands for reproduction and the differential distribution of amphibian species along a gradient of wetland permanence is striking, yet not absolute. Wood frogs (Rana sylvatica) and spotted salamanders (Ambystoma maculatum) are thought to rely on seasonal wetlands for greatest breeding success, but there is little documentation of their reliance on these or other habitats. In my first chapter, I studied these species in wetlands across a hydrologic gradient from seasonal wetlands of short flood duration to permanently flooded sites. My results indicate that wood frogs have greatest reproductive effort and success in …