Digital Commons Network^™

Analysis Of Arabidopsis Thaliana Protein Phosphatase 2a C Subunit Expression, Megan M. Thompson

Master's Theses and Capstones

Reversible protein phosphorylation is required for presumably most biological pathways. One of the major enzymes involved in eukaryotic dephosphorylation is Protein Phosphatase 2A (PP2A). PP2A is composed of three subunits: A (scaffolding), B (regulatory), and C (catalytic). Our lab is interested in determining the function of the five C subunits (C1, C2, C3, C4 and C5) in Arabidopsis thaliana. We have identified a Na+-induced altered root growth phenotype in c4 mutant plants. The goal of this project was to determine expression of the five C subunit genes throughout the life cycle of Arabidopsis with emphasis on correlating the location of …

Building And Deployment Of An Automated, In Situ Greenhouse Gas Gas Chromatographic System, Andrew H. Hart

Master's Theses and Capstones

High-precision, continuous monitoring of greenhouse gases, such as carbon dioxide (CO2), methane (CH4), nitrous oxide (N 2O), sulfur hexafluoride (SF6), and the criteria pollutant carbon monoxide (CO), is important for characterizing their regional sources and sinks and understanding how their ambient levels are changing with time and associated anthropogenic activities. For monitoring this suite of gases, a fully automated gas chromatographic based analytical system was built and deployed in the field at the UNH AIRMAP Observing Station at Thompson Farm in Durham, NH. The instrument consists of a Shimadzu 17A gas chromatograph (GC), equipped with a Flame Ionization Detector and …

Discovering Signaling Events In The Actinorhizal Symbiosis, Nicholas J. Beauchemin

Master's Theses and Capstones

Although the symbiosis between Frankia and actinorhizal host plants has been widely studied, very little is known about the initial molecular interactions. To address this issue, Casuarina cunninghamiana root exudates were collected and tested on Frankia Ccl3. Frankia growth yield was enhanced by root exudates but Frankia could not utilize them as a sole carbon and energy source. Exposure to root exudates caused Frankia hyphal curling and surface property changes in fatty acids and carbohydrates. Pre-exposure to root exudates also decreased the time required for nodule initiation. The results show that root exudates and Frankia physiological changes for symbiosis are …

Assessing Relationships Of Moose Populations, Winter Ticks, And Forest Regeneration In Northern New Hampshire, Daniel Henry Bergeron

Master's Theses and Capstones

This study examined relationships among winter ticks, weather, and the nutritional and reproductive status of moose, and the impact of moose on regeneration of commercial forests in northern New Hampshire. Three methods were evaluated to assess their usefulness as indices of relative winter tick abundance, and predictors of tick epizootics: tick counts on harvested moose and roadside, spring hair-loss surveys were considered time and cost effective to index winter tick abundance. Physical characteristics of harvested moose (1988--2009) indicated ovulation rates (∼20%), and mean body weight (<200 kg) of yearlings declined since 1988; because adult body weight and ovulation rates remained stable, habitat quality was unlikely related. Winter tick epizootics are likely influenced by abnormal large scale weather events, as evident in the widespread die-off in 2002 associated with warm snowless conditions into mid-December 2001 that extended tick transmission to moose. Spring and fall weather should be monitored for unusual conditions causing high tick abundance and tick loads, particularly warm and snowless conditions in April and December. Mean stocking rate of all age classes of commercial tree species was above the threshold in all regions (49--87%); forest regeneration was not considered a regional problem at any moose density.

Interactions Between Adaptive Mutations In The Environment And The Consequences For Adaptation In Escherichia Coli, Kenneth Mark Flynn

Master's Theses and Capstones

Phenotypic plasticity, epistasis or both are expected to influence the adaptive value of mutations and, by extension, how organisms adapt to new environments. We investigated interactions among five mutations that arose and fixed in a laboratory-evolved population of E. coli in a variety of different external environments. Overall, we found that positive pleiotropy tended to be positive rather than antagonistic and that epistatic interactions were common regardless of the external environment. The nature of the epistatic interactions depended strongly on the external environment and altered which adaptive paths were selectively accessible. Ultimately, achieving high fitness in a new environment was …

Herbage Mass Accumulation In An Intensive Rotational Grazing System At Unh's Organic Dairy Research Facility, Ashley Green

Master's Theses and Capstones

Pasture-based animal management in the Northeast U.S. relies on the ability to efficiently estimate pasture production and animal intake. Accuracy and precision of a rising plate meter, NDVI meter, and height measurements for estimating pasture biomass were compared relative to hand-clipped samples. Pasture measurements were used to describe biomass accumulation, lactating dairy herd intakes, and re-growth patterns for intensively rotated pastures. Pastures were measured from May-September, 2009 at the UNH Organic Dairy Research Facility in Lee, NH. The rising plate meter provided the most robust estimates of biomass (R²=0.58, SEE=2.73). Forty-seven paddocks were measured for 82 total grazing events; grazing …

The Effects Of Historic Earthen Barriers On Northern New England Tital Marshes, Jordan W. Mora

Master's Theses and Capstones

Berms, defined as historic earthen barriers, represent one type of hydrological modification introduced by humans in the tidal marshes of northern New England. Three different research approaches were applied to study the impact of berms on various tidal marsh dynamics. The descriptive study shows that restricted flooding from berm interference can result in significantly altered physical gradients in addition to landward subsidence and pool development. The results from the transplant experiment indicate that the altered landward structure affects the relative importance of biological interactions, namely herbivory, in controlling plant species distribution. The predictive GIS analyses illustrate the location of 34 …

Nonlinear Evaluation Of Stock Assessment And Marine Ecosystem Models, Laura Storch

Master's Theses and Capstones

In fisheries management, single-species stock assessment models use fisheries-dependent catch and landings data along with fishery-independent estimates of relative or absolute abundance to make estimates of species biomass for a given area. This output is used by the Atlantis marine ecosystem model as input. Atlantis uses an array of physical, biological, and anthropogenic factors to predict biomass for individual species or functional groups of species. Nonlinear analysis was used to assess the output for both the stock assessment, and Atlantis models for the marine ecosystem off the California coast. The number of time series displaying nonlinear characteristics decreases from raw …

The Spatial And Temporal Distribution, Population Growth Strategies And Options For The Removal Of The Invasive Shore Crab Carcinus Maenas In Two New Hampshire Estuaries, Beth Allison Fulton

Master's Theses and Capstones

The spatial and temporal distribution of the green crab, Carcinus maenas, along with various green crab population parameters, were studied in two New Hampshire estuaries over a one-year period from November 2009 to October 2010. Results show that foraging activity in Great Bay Estuary peaked in December and March, and in HSE, in April and November. Crabs in both estuaries experienced synchronous breeding periods. Males experienced two molts per year in April and November, while females molted synchronously in June. Embryogenesis was accomplished within the month of June. Minimum size at maturity for females in New Hampshire was larger than …

Effects Of Habitat Fragmentation And Water Quality On Wood Frog Population Genetic Structure In Vernal Pools, Charlotte Gabrielsen

Master's Theses and Capstones

Habitat fragmentation associated with suburbanization can have negative consequences on population persistence through the reduction of dispersal and concomitant gene flow. Using nine polymorphic microsatellite loci, I assessed the effects of forest fragmentation and water quality on the genetic structure of a vernal pool-breeding amphibian, the wood frog ( Lithobates sylvaticus), across 20 ponds in an unfragmented, forested landscape and 45 ponds in a fragmented landscape. Analyses were performed at the broad-scale of the study area and at a fine-scale, with spatially independent clusters of ponds selected within each landscape. Bayesian clustering approaches and AMOVA identified little population structure at …

A Two-Dimensional Hexagonal Network Model Of Alveolar Mechanics, Danielle Nangle

Master's Theses and Capstones

Pulmonary micromechanics (at the scale of alveoli) involves a delicate balance among tissue material properties, geometry, surface tension, pressure and stress distribution. To date, there is not a consensus among alveolar mechanics researchers about how these factors interact, in part because alveoli are so difficult to image and study in vivo. Here, we propose a basic mathematical model of a two-dimensional hexagonal network of mechanically coupled alveoli. We investigate equilibrium configurations of both dry and wet, internally pressurized elastic networks. Specifically, we compute pressure-area curves to quantify the differences among networks with different spring constants, internal pressures, network size and …

Effect Of Carex Rostrata Removal On Methane Emissions From A Temperate Peatland, Genevieve L. Noyce

Master's Theses and Capstones

Peatlands are a large natural source of atmospheric methane (CH4). Carex rostrata, a sedge species, has a critical role in the production, oxidation, and emission of CH4 from these systems. This study examined the changes in CH4 emissions from a temperate peatland after removing all aboveground C. rostrata biomass. Methane flux, dissolved CH4 concentration at various depths, C. rostrata green leaf area, temperature, and water table depth were measured from June 2008 to November 2010.

There is a strong positive correlation between C. rostrata green area and CH4 flux and the mean summer CH4 flux from the control plots was …

Saprotrophic Fungi As A Mechanism For Vertical Nitrogen Transport In A Chronically Fertilized Northern Hardwood Forest, Katharine M. Burnham

Master's Theses and Capstones

Decay studies often observe that plant litter increases in the amount of nitrogen within the first year of decomposition, yet sources are uncertain. The Harvard Forest Chronic Nitrogen Amendment Experiment, Petersham, MA, was utilized to quantify vertical N translocation from soil up into decomposing litter and determine if long-term, chronic N application has affected this process. Litter bags were designed to facilitate or restrict fungal hyphal connectivity between the soil-litter interface and placed in control, low N+S and high N plots. After five or 12 months, a 15N-(NH 4)2SO4 solution was horizontally injected into organic soil beneath bags. 15N enrichment …

Identification And Characterization Of Photorhabdus Temperata Mutants Altered In Hemolysis And Virulence, Christine A. Chapman

Master's Theses and Capstones

Photorhabdus temperata is an invertebrate pathogen and nematode symbiont that is commonly used as a biological control agent in the management of commercial crop pests. The focus of this study was to investigate the poorly understood molecular elements involved in the expression of hemolysis and virulence in this bacterium. A 10,000 transposant library was screened using a blood agar plate assay to identify mutants altered in hemolytic activity. A total of 74 mutants displaying defective, delayed, or early hemolysis were identified and subsequently tested for altered virulence in the Greater Waxmoth, Galleria mellonella, using an in vitro mortality assay. Ten …

Studies Of Net Community Productivity In A Near-Coastal Temperate Ecosystem, Olivia De Meo

Master's Theses and Capstones

Understanding the biological contribution to the carbon cycle is important to accurately calculate oceanic carbon budgets. The biological contribution to air-sea flux can be expressed as net community productivity (NCP), or the difference between gross primary production and community respiration. This study conducted two experiments to constrain NCP in a near-coastal region. The first experiment conducted in the western Gulf of Maine (GoM) sought to identify an indirect optical proxy for NCP that would allow for the determination of NCP remotely by satellite in the future. NCP results indicated that the GoM was near equilibrium during our study. Changes in …

Identification And Characterization Of Photorhabdus Temperata Mutants Altered In Cell Surface And Symbiosis, Cintia R. Felix

Master's Theses and Capstones

Photorhabdus temperata forms a mutualistic association with the entomopathogenic nematode Heterorhabditis bacteriophora. Nematode growth and development has an obligate requirement for the bacterial symbiont. The objective of this study was to identify and understand cell surface properties that are required for symbiosis. A previously generated library of 10,000 P. temperata transposon mutants was screened for altered surface properties via a calcofluor dye-binding assay. Seventeen mutants were identified and tested in vitro for symbiosis. Key mutants were tested for symbiosis and insect pathogenesis in vivo with Galleria mellonella larvae. Five mutants showed at least a 10-fold decrease of IJ yield. Four …

Optimized Identification Of Fecal Pollution Sources In A Rural Tidal Watershed In Coastal New Hampshire, Sana B. Hussain

Master's Theses and Capstones

Escherichia coli ribotyping was used to identify fecal contamination sources in Grommet Creek- a tidal creek that drains into Great Bay and contaminates shellfishing beds. Water samples were collected during late summer through late fall. Fecal samples were collected to establish a local source species database. Fecal indicator bacteria were enumerated from water samples and ribotyping was conducted by using EcoR1 restriction enzyme digestion and an automated RiboPrinter(c). There was consistent relative abundance between source types with wild animals and birds as the primary sources. An optimized approach for maximizing source identification involved using a 90% similarity threshold and prioritizing …

Assessing Innovative Zero-Valent Iron Separation Processes In An Arsenic Treatment Scheme, Nathan H. Little

Master's Theses and Capstones

Arsenic contamination in drinking water is a worldwide public health concern associated with serious acute and chronic health effects. Listed as a "Group A" human carcinogen, arsenic is regulated in drinking water at 0.010 mg/L by the U.S. Environmental Protection Agency (EPA). Arsenic contamination stems from both natural and anthropogenic sources, and areas with high levels of arsenic can be found in countries throughout the world, including the United States (Smedley and Kinniburgh 2002). In the past decade, interest in iron-based sorbents, particularly zero-valent iron (ZVI), has developed for their use as an arsenic-removal technique due to the lack of …

Net Resiliency: A Study Of Risk And Protective Factors In Single And Two-Parent Familes, Chad E. Depasquale

Master's Theses and Capstones

The main goal of this study was to discover how family makeup affects net resiliency scores of children. This quantitative study uses Two-Tailed t-tests, and Pearson correlation to uncover any relationships between net resiliency and living in a single or two-parent household. A sample of 91 children ranging from eleven to eighteen years old was utilized for the study's data collection. Their net resiliency scores, risk factors, protective factors, and family makeup were analyzed to discover any potential relationships between them. The analysis of these factors showed children living in single-parent families have: lower net resiliency scores, fewer protective factors, …

A Mentor Training Module Designed To Build Resiliency For Homeless Emerging Adults, Courtney J. Edwards

Master's Theses and Capstones

Homelessness in emerging adulthood is a problem that potentially creates a lifetime of extreme poverty and limits the ability to thrive in adulthood. The literature demonstrates a need for programs specific to the homeless emerging adult population. A mentoring program is beneficial because the relationship between the mentor and mentee can offset developmental and psychosocial shortfalls that impede the individual's transition to adulthood. The homeless emerging adult needs a sense of belonging and positive role models. The theories of Maslow and Bandura therefore become the foundation of the mentoring training manual. The Walk with Me mentoring program manual and training …

A Messenger Molecule Governs Interdependency In An Evolved Pseudomonas Aeruginosa Biofilm Community, Thomas Macelliott Johnson

Honors Theses and Capstones

Biofilm populations are known to harbor great diversity, but the importance of this diversity is not fully understood. A likely contributor to this variation is the second messenger molecule cyclic-di-GMP: low levels associate with a planktonic lifestyle while high levels favor biofilm formation. In ongoing studies of an evolving biofilm population of Pseudomonas aeruginosa (PA), we observed extensive ecological diversification that may relate to this lifestyle switch. In PA, the gene bifA encodes a phosphodiesterase that is known to degrade cyclic-di-GMP and reduce biofilm. This gene was cloned onto a plasmid under control of an inducible promoter and the plasmid …

Dispersants And Seafood Safety Assessment Of The Potential Impact Of Corexit® Oil Dispersants On Seafood Safety, Robert W. Dickey, Walton W. Dickhoff

Coastal Response Research Center

The April 20, 2010 explosion and subsequent sinking of the Deepwater Horizon oil production platform (DWH) resulted in the largest oil spill in U.S. history. On April 29th, a Spill of National Significance was declared as roughly 53 thousand barrels of oil per day flowed into the Gulf of Mexico (GOM). The U.S. Coast Guard estimated 4.9 million barrels of crude oil escaped before the damaged DWH wellhead was sealed on July 15, 2010 (National Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling 2010). Oil spill clean-up methods included skimming operations, burning of surface oil, siphoning oil …

The Frequency And Cause Of Shallow Winter Mixed Layers In The Gulf Of Maine, Michael Christensen

Master's Theses and Capstones

In the Gulf of Maine, regional differences in wintertime stratification have important biological and physical implications. Phytoplankton blooms linked with shallow stratification events during the winter are important because they can provide an additional food source for zooplankton and larval fish populations. Regional differences in stratification and mixed layer depth may also affect rates of air-sea gas exchange. On an annual basis, variability in wintertime air-sea CO2 exchange is significant since it can affect the entire region's role as a sink or source of atmospheric carbon. Before examining how patterns in stratification affect biological and physical systems in the Gulf …

Genes Differentially Expressed At 1 Day, 6 Weeks, And 6 Months Of Age In Aortas Of Spontaneously Atherosclerotic White Carneau Pigeons, Suzanne Lee Pearlman

Master's Theses and Capstones

Genetics is reported to be the primary causative factor for individuals diagnosed with atherosclerosis, in the absence of known risk factors. The development of atherosclerosis in White Carneau (WC) pigeons is of genetic origin, making it an excellent model to study genetic factors.

Representational Difference Analysis (RDA) was used to determine genes differentially upregulated between three ages, at the celiac bifurcation of the aorta in WC pigeons. Genes responsible for spontaneous initiation of atherosclerosis were hypothesized as being differentially expressed at 1 day, while those differentially expressed at 6 weeks and 6 months were related to progression.

Multiple candidate genes …

Synthesis Of Cadmium Selenide-Gold Hybrid Nanorods, Xiaoxiong Jia

Master's Theses and Capstones

In this work, we reported the synthesis of cadmium selenide-gold (CdSe-Au) hybrid nanorods. The growth substrates, CdSe nanorods, were synthesized using a simple mono-injection method. The growth models for CdSe with different morphologies were proposed, and validated by the experimental results. It can be briefly described as concentrated CdSe monomers were prone to forming isotropic CdSe nanoparticles; while diluted CdSe monomers were prone to forming anisotropic CdSe nanorods. The growth of Au nanoparticles on the surface of CdSe nanorods was achieved via galvanic replacement reactions between Au ions (AuCl3) and CdSe nanorods at room temperature. By adjusting the reaction times, …

New Media Use And Rural Youth Substance Use, William Meub

Master's Theses and Capstones

Data from the Coos county youth survey is used to examine new media use habits and explore the relationship between new media use and substance use among two cohorts of rural youth (N = 657). Specifically, I present descriptive information on new media usage, examine whether new media use is related to substance use and explore a possible moderation relationship between substance use and negative substance-use-related behavioral outcomes. Older adolescents reported more new media use than younger adolescents but there was no evidence of sex differences in usage. Greater new media use was found to be related to greater substance …

Goose Pond, Cooperative Extension

UNH Cooperative Extension

No abstract provided.

Naticook Lake, Cooperative Extension

UNH Cooperative Extension

No abstract provided.

Outreach And Citizen Engagement In The Winnicut River Watershed: A Participatory Action Study, Jillan Scahill Farrell

Master's Theses and Capstones

Recently, citizen initiated watershed management has seen a rise in popularity. Citizen watershed groups have been created across the country especially in New England. These groups advocate for protections and responsible watershed-wide management. Each watershed contains a certain set of unique ecological, social, regulatory and problem situations and therefore each watershed organization requires a full mapping process of the policy and social process as well as the ecological and problem situation before engaging the citizens. This research explores the Winnicut River watershed in southeastern New Hampshire. Covering three communities and representing a subwatershed of the Great Bay coastal watershed this …

Physical Transport And Chemical Behavior Of Dispersed Oil, James R. Payne, C. J. Beegle-Krause

Coastal Response Research Center

During response operations, scientific information is provided to decision makers, such as the Federal On-Scene Coordinator (FOSC), state and federal trustees, and the public. The decision to use chemical dispersants during a response is made among all these parties, and during the Deepwater Horizon (DWH) oil spill the dispersant discussion included both surface and subsurface application of chemical dispersants. This paper is intended to provide perspective on research needs considered pre- and post-DWH oil spill related to response modeling and data collection needs for decision support of dispersant application and its potential effects. Given time constraints for implementing models and …