Digital Commons Network^™

Evolution Of Pycnogonid Life History Traits, Eric Carl Lovely

Doctoral Dissertations

The Pycnogonida is a class of arthropods with interesting life histories. Pycnogonids prey on hydroids and some invade hydranths while larvae. Males brood the eggs and larvae hatch as protonymphons. Questions relating to the evolution of life history characteristics were addressed. Evolutionary relationships were poorly understood. It was necessary to determine the relationships within the Pycnogonida and compared to other arthropods.

Twenty-four morphological characters were coded for twenty-three pycnogonid genera and one fossil ancestor, Palaeoisopus problematicus. A branch and bound analysis resulted in fifteen most parsimonious trees. The Nymphonidae were found to be basal. The Ammotheidae were paraphyletic and led …

The Effect Of Physical And Biological Site Characteristics On The Survival And Expansion Of Transplanted Eelgrass (Zostera Marina L), Ryan Clark Davis

Doctoral Dissertations

Eelgrass (Zostera marina L.) was transplanted at seven sites along the New Hampshire side of the Piscataqua River in 1993 and 1994. The eelgrass transplanting was one component of the New Hampshire Port Authority Mitigation Project, designed to mitigate for impacts to natural resources associated with the expansion of the port facility. Over 2.5 hectares of eelgrass were transplanted using a newly developed transplanting technique, the horizontal rhizome method, and ultimately created eelgrass habitat at several sites. However, transplants did not survive at any of the intertidal areas planted and were greatly reduced at several subtidal sites. The intertidal transplants …

Effects Of Intralaminar Thalamic Nuclei, Prefrontal Cortical, And Hippocampal Lesions On A Seven-Choice Serial Reaction Time Task, Joshua Alan Burk

Doctoral Dissertations

Slow response speed has been associated with several neuropsychological disorders including Korsakoff's disease. The ability to respond to brief stimuli can be tested to assess whether slow response speed is due to slow stimulus processing. A seven choice serial reaction time task was developed to test the ability to respond to brief stimuli. Distractibility and stimulus discriminability were manipulated to challenge performance and cues were presented to enhance performance. In Experiment 1, six unlesioned rats were tested on this task. As expected, significant deficits were found when (1) stimulus duration was decreased, (2) bright distractor light was briefly presented, (3) …

Isolation And Characterization Of A Caenorhabditis Elegans Src Loss-Of-Function Allele Using Reverse Genetics, Jennifer Dignan Hogan

Doctoral Dissertations

The vertebrate proto-oncogene Src is a protein-tyrosine kinase that has been implicated as a component of receptor-mediated signal transduction pathways important for cell growth and differentiation. Consistent with this notion, overexpression or activation of Src by mutation induces neoplastic transformation in cell culture, leads to tumorigenesis in laboratory animals, and has been observed in a number of human tumors. Despite years of intensive investigation, neither its role in oncogenesis nor its normal, biological role is understood.

To diminish the issue of redundancy that has complicated analysis of Src function in vertebrates and Drosophila, I have chosen to study Src function …

The Role Of Cytokines In The Pathogenesis Of Experimental Legionella Pneumophila Infections, Corinna Mary Krinos

Doctoral Dissertations

Legionnaires' disease is an acute lobar pneumonia caused, primarily by the facultative intracellular pathogen Legionella pneumophila. This organism when inhaled by humans descends into the lower respiratory tract and parasitizes alveolar macrophages. L. pneumophila adhered to U-937 cells, A549 cells and peritoneal macrophages from A/J mice in an opsonin-independent fashion. Following attachment, the organism penetrated the cell membrane, replicated within these cells eventually inducing lysis. To better define the adhesion of L. pneumophila to host cells, an E. coli clone (LP 116), expressing the 25 kDa major outer membrane protein (MOMP) of L. pneumophila was used in binding studies. This …

The Long-Term Effects Of Disturbance On Nitrogen Cycling And Loss In The White Mountains, New Hampshire, Christine Lynn Goodale

Doctoral Dissertations

Theories of nitrogen retention suggest that N cycling and loss should increase with ecosystem successional age and with chronic N deposition over time (N saturation). These factors both affect northeastern U.S. forests, most of which receive elevated rates of N deposition and have experienced past disturbances by wind, logging, fire, or agriculture. This work examined the long-term (80--110 year) effects of land-use history on nitrogen cycling and loss in the White Mountains, New Hampshire. Historical land-use maps were used to identify a network of watersheds and plots containing burned, logged, or old-growth forests. Nitrate-N fluxes from old-growth watersheds exceeded those …

Behavioral And Physiological Responses Of The Lobster, Homarus Americanus, To Temperature: A New Synthesis, Steven Harold Jury

Doctoral Dissertations

Temperature has a pervasive influence on lobster behavior, physiology and ecology and affects their subsequent distribution in thermally variable habitats such as estuaries and coastal areas. A multidisciplinary approach, including field and laboratory studies, was used to show: (1) that lobsters sense temperature with warm and cool thresholds as small as 0.1--0.2°C; (2) the relationship between temperature and activity is not linear, but instead switches between a high activity level in warmer months (10--20°C) and a lower level in colder months (<10°C) with transition periods in the spring and fall; (3) Parallel studies in the lab and field show that daily levels of activity are not greatly influenced by small temperature variations (i.e. tidally induced changes of 14°C), but activity levels are significantly higher in the field (249 +/- 55.1 m/d) than in the laboratory (88 +/- 12.0 m/d); (4) lobsters prefer a narrow range of temperatures over others available in a thermal gradient and avoid temperatures >23.5 +/- 0.4°C, suggesting that they behaviorally thermoregulate. While this preferred temperature shifts seasonally, the final preferred temperature …

Controls On Spatial And Temporal Variability In Nitrous Oxide Fluxes Across A Tropical Rainforest Ecosystem In The Luquillo Experimental Forest, Puerto Rico, Claire Patricia Mcswiney

Doctoral Dissertations

Nitrous oxide (N2O) is a trace gas that contributes to the greenhouse effect and participates in the reactions that destroy stratospheric ozone. Soil microbial processes are significant producers of this trace gas, particularly in tropical areas, which are considered major sources in the global N2O budget. Nitrous oxide fluxes to the atmosphere are variable in space and time. In this study, spatial and temporal variability in surface N2O fluxes were assessed as well as the major environmental controls on N2O production for a tropical rainforest watershed in northeastern Puerto Rico. A static chamber technique was used to assess surface fluxes …

Functional Characterization Of The Ccr4-Not Transcriptional Regulatory Complex, Vasudeo Badarinarayana

Doctoral Dissertations

The CCR4-NOT transcriptional regulatory complex affects expression of a number of genes both positively and negatively. This study demonstrates that the CCR4-NOT complex functionally and physically interacts with TBP and TAFs. Firstly, mutations in CCR4, NOT4, and NOT5 suppressed the his4-912 delta insertion by a mechanism similar to that observed for the defective TBP allele spt15-122. This mechanism appeared to involve stabilization of TBP binding to a specific non-consensus TATA sequence, CATAAA, in the his4-912 delta element. Secondly, using modified HIS3 promoter derivatives containing specific mutations within the TATA sequence, it was found that the NOT proteins were general repressors …

The Mut-2 Mutator Of Caenorhabditis Elegans, Kathrine Queta Flint Boese

Doctoral Dissertations

The mut-2 mutator plays multiple regulatory roles in the germ line of C. elegans. In addition to regulating germ line transposition of at least four distinct transposon families (Tc1, Tc3, Tc4 and Tc5) mut-2 is implicated in chromosome segregation. Animals that harbor the mut-2 mutator produce broods with a higher incidence of males phenotype (Him) as a result of an increase in X chromosome non-disjunction during meiosis.

Using the Him phenotype conferred by mut-2(r459), I mapped the gene to the dpy-14 sem-4 interval on LGI. However, efforts to identify a molecular clone of the gene were hampered because the available …

The Development Of Rna Probe And Rt-Pcr Assays For The Detection Of Enteroviruses In Sludge, Amy Elisabeth Moore

Doctoral Dissertations

Many wastewater treatment plants generate more sludge than can be disposed of by conventional means. The United States Environmental Protection Agency (USEPA) has encouraged communities to dispose of sludge by land application. Sludge may contain enteric viruses that are known to survive for long periods of time in sludge-amended soil and can travel great distances, potentially contaminating surface and ground water.

Standard cell culture methods for the detection of enteric viruses are costly and results are not obtained for 30 or more days. The development of methods that provide results more quickly and with lower cost are needed.

A 32P …

Viability And Spatial Assessment Of Ecological Communities In The Northern Appalachian Ecoregion, Mark Gustav Anderson

Doctoral Dissertations

My objective was to design a conservation reserve system that included multiple viable examples of all ecological community types within one specific ecoregion---the Northern Appalachians. I developed and defined the boundaries of the ecoregion, constructed a comprehensive list of the ecological communities and determined their scale of occurrence and distribution patterns. I also assessed the types and distributions of biophysical features within the ecoregion and developed a hierarchical scheme to partition the region into biophysical subregions. Subsequently, I assessed 1500 occurrences of ecological communities in the region compiled from state Natural Heritage databases and an analysis of roadless areas. Each …