Physical Sciences and Mathematics Commons^™

Comparative Evolution Of Molecular Markers: An Analysis Of Genetic Variation Within The Blue Marlin (Makaira Nigricans), Vincent Patrick Buonaccorsi

Dissertations, Theses, and Masters Projects

Blue marlin diversity was assessed at mtDNA, scnDNA, microsatellite DNA, and allozyme molecular markers. Hierarchical analysis of molecular variance (AMOVA) revealed that most genetic variation was maintained within populations, with a non-significant fraction attributable to variation among temporal replicates and between locations within oceans. In contrast, inter-ocean divergence was highly significant for a majority of loci within each marker class. Previous studies of mitochondrial DNA (mtDNA; n = 104) genetic variation within the blue marlin revealed two distinct clades of haplotypes, one of which was present only in the Atlantic (the 'Atlantic clade'), at a frequency of 40% &(F\sb{lcub}st{rcub}& = …

Electroproduction Of The S(11)Meson(1535) Resonance At High Momentum Transfer, Christopher Stephen Armstrong

Dissertations, Theses, and Masters Projects

The amplitude of the $S\sb{11}$(1535) resonance at values of four-momentum transfer $Q\sp2 > 0$ is not explained by the nonrelativistic constituent quark model, and is currently a topic of theoretical interest; in addition, the large branching fraction of this resonance to the proton-$\eta$ decay channel is not well understood. There is also controversy concerning the $Q\sp2$ regime in which perturbative QCD becomes important in describing nucleon resonances such as the $S\sb{11}$. The $p(e, e\sp\prime p)\eta$ reaction is an excellent system in which to study this resonance and address the issue of possible perturbative effects: the $p\eta$ channel is not accessible to …

Exploiting Cache Locality At Run-Time, Yong Yan

Dissertations, Theses, and Masters Projects

With the increasing gap between the speeds of the processor and memory system, memory access has become a major performance bottleneck in modern computer systems. Recently, Symmetric Multi-Processor (SMP) systems have emerged as a major class of high-performance platforms. Improving the memory performance of Parallel applications with dynamic memory-access patterns on Symmetric Multi-Processors (SMP) is a hard problem. The solution to this problem is critical to the successful use of the SMP systems because dynamic memory-access patterns occur in many real-world applications. This dissertation is aimed at solving this problem.;Based on a rigorous analysis of cache-locality optimization, we propose a …

Platinized Tin Oxide: A Low-Temperature Oxidation Catalyst, Erik Joshua Kielin

Dissertations, Theses, and Masters Projects

Some combinations of noble metal and reducible metal oxide possess a synergistic level of activity for the catalytic oxidation of CO at lower temperatures and partial pressures of O2 than can be obtained by either component alone. The most promising candidates, Au on MnO2 and Pt on SnO 2, were investigated for the effects on activity of noble metal loading, of reductive pretreatment at elevated temperature, and of reaction gas mixture composition. Optimum activity was obtained at a noble metal loading of 28% Au/MnO2 and 17% Pt/SnO2. Both catalysts benefitted from reductive CO pretreatment at 125??C. Both catalysts showed enhanced …

Chincoteague Bay, Virginia, Effectiveness Of The Sav Sanctuary And Revegetation Of Sav Habitat Disturbed By Clam Dredging - Report To The Virginia Marine Resources Commission, Robert J. Orth, Ken Moore, David J. Wilcox, James R. Fishman

Reports

No abstract provided.

Storm Surges In The Region Of Western Alaska, Warren Blier, Stanley Keefe, Wilson Shaffer, Sung C. Kim

VIMS Articles

Within the period of the historical record there have been several occurrences of extensive damage from storm-surge-related coastal flooding in the region of Nome, Alaska. The most recent of these events, although by no means the most destructive, occurred in association with the storm of 5–6 October 1992. Despite the small population of Nome (approximately 4000 people), total damage costs exceeded $6 million. The research into the nature and causes of such flooding events has focused on this October 1992 case. The authors have, however, also examined a weaker, shorter-duration event that occurred on 20 August 1993 and, for contrast, …

Investigation Of Isolated Sand Shoals On The Inner Shelf Of Virginia Relative To The Potential For Aggregate Mining : Report On Study Of Possible Wave Force Alternations On The Proposed Dredging At Sandbridge Shoal, Va, Jerome Y.-P. Maa, Carl H. Hobbs Iii

Reports

The Virginia Institute of Marine Science, together with other state agencies, has a continuing interest in preserving the coastline of Virginia, particularly, the Atlantic coastline in the vicinity of the resort city of Virginia Beach. Because a well maintained beach can serve several purposes , e.g., ( 1) providing public recreational areas, (2) protecting valuable properties that are located near coastline , and (3) reducing the rate of land loss, a great deal of efforts has been devoted to understand the processes that affect the change of shoreline. Among several erosion forces , waves are especially important elements as they …

Comparisons Of Gears And Vessels Used In The Virginia Institute Of Marine Science Juvenile Finfish Trawl Survey, David Hata

Reports

The Virginia Institute of Marine Science (VIMS) currently conducts a monthly trawl survey in the three major Virginia rivers and the lower Chesapeake Bay to estimate the abundance of economically important finfish species, particularly at the juvenile stage .. VIM:S has conducted similar trawl surveys in various forms since 1955. Although this represents a 40 year period, variations in sampling design and gear have confounded efforts to produce a meaningful, continuous time series. Such variations include changes in stations occupied, sampling frequency, _vessels, and trawl gears. Much of the trawl survey sampling has been documented (Wojcik and Van Engel 1988a, …

The Virginia Wetlands Report Vol. 12, No. 3, Virginia Institute Of Marine Science

Virginia Wetlands Reports

• Barred Owl. Julie G. Bradshaw
• Yellow Perch. Lyle Varnell
• Targeting for Effective Wetlands Preservation. Marcia Berman and Lynn M. Dancy
• Chesapeake Bay Program Wetlands Initiative - New Approach Allows the Identification of Locally Important Wetlands. Carl Hershner
• Chesapeake Executive Council Directive
• Peat: Processing and Potential for Restoration. Pam Mason
• What is marsh toe protection and how does it protect a wetland? William Roberts

The Oldest Operating Wetland Mitigation Bank In The U.S. A Review Of The Goose Creek Wetland Bank In Chesapeake, Virginia; It's Development And Utilization, Thomas A. Barnard Jr., Carl Hershner, Megan Greiner, Virginia Institute Of Marine Science, Wetlands Program

Reports

No abstract provided.

Recurrence Spectroscopy Of A Time-Dependent System: A Rydberg Atom In An Oscillating Field, Neal Spellmeyer, Daniel Kleppner, M. R. Haggerty, V. Kondratovich, John B. Delos, J. Gao

Arts & Sciences Articles

We report the results of an experimental and theoretical investigation of the recurrence spectra of Rydberg atoms in a static plus weak oscillating electric field. Experiments reveal the systematic weakening of orbits in a recurrence spectrum as the oscillating field strength and frequency are changed. We describe a generalization of closed orbit theory to time-dependent systems and show that it provides a qualitative and quantitative description of the phenomena.

A Generalized Univariate Change-Of-Variable Transformation Technique, Andrew G. Glen, Lawrence Leemis, John H. Drew

Arts & Sciences Articles

We present a generalized version of the univariate change-of-variable technique for transforming continuous random variables. Extending a theorem from Casella and Berger [1990. Statistical Inference, Wadsworth and Brooks/Cole, Inc., Pacific Grove, CA] for many-to-1 transformations, we consider more general univariate transformations. Specifically, the transformation can range from 1-to-1 to many-to-1 on various subsets of the support of the random variable of interest. We also present an implementation of the theorem in a computer algebra system that automates the technique. Some examples demonstrate the theorem's application.

Sediments And Shallow Stratigraphy Of A Portion Of The Continental Shelf Of Southeastern Virginia, Carl H. Hobbs Iii

Reports

A network of high-resolution, seismic-reflection profiles and grab samples of the surficial sediments of the inner continental shelf of southeastern Virginia demonstrate that the Quaternary geology of the region is more complex than indicated by earlier studies. The spatial variability of the surficial sediments depicts active processes, such as outflow from Chesapeake Bay, as well as the underlying geology in outcrops of finer grained sediments near False Cape.

The complexity of the Quaternary geology results from large and small scale fluctuations in sea level. Individual, relatively large-scale, seismostratigraphic units are separated by erosional surfaces formed during the major changes in …

The Virginia Wetlands Report Vol. 12, No. 2, Virginia Institute Of Marine Science

Virginia Wetlands Reports

• Brown Pelican. Julie G. Bradshaw
• Spot. Lyle Varnell
• Fish Lesions, Pfiesteria and the Chesapeake Bay
• GIS as a Tool for Planning and Evaluating Wetland Mitigation Compensation Sites. Marcia Berman
• Wetlands Mitigation Banks: Creating Big Wetlands to Compensate for many Small Losses. Carl Hershner
• Wetlands Protection and Restoration Goals
• Peat: Use Through the Centuries. Pam Mason
• Does my erosion control structure affect my neighbor’s shoreline? William Roberts

Quantum Manifestations Of Bifurcations Of Closed Orbits In The Photodetachment Cross Section Of H- In Parallel Fields, Aaron D. Peters, Charles Jaffé, J. Gao, John B. Delos

Arts & Sciences Articles

In the preceding paper, we showed that the semiclassical approximation diverges at a bifurcation, and that this divergence coincides with the passage of a focused cusp through the origin. Here we obtain a wave function in the vicinity of this cusp, and we use that wave function to eliminate the divergences in the photodetachment cross section. To describe the focused cusp, we first discuss the wave function of an ordinary two-dimensional (nonfocused) cusp. This wave function is known as a Pearcey function, and it has been studied extensively. Then we show how the formulas that lead to the Pearcey function …

Semiclassical Formula For Oscillator Strengths In Atomic Spectra, V. Kondratovich, John B. Delos

Arts & Sciences Articles

A simple semiclassical formula is given for the oscillator strengths of high Rydberg states of a hydrogen atom in an electric field. The oscillator strength of a state is proportional to the square of the function representing the quantum angular distribution of outgoing waves, evaluated at the classical angle of ejection from the atom that sends the electron into a semiclassically quantized eigentrajectory. The formula gives an interpretation of the envelopes of Stark manifolds in photoabsorption spectra; it is in good agreement with quantum calculations. The formula may also be used for other integrable or near-integrable systems.

Closed-Orbit Theory And The Photodetachment Cross Section Of H- In Parallel Electric And Magnetic Fields, Aaron D. Peters, Charles Jaffé, J. B. Delos

Arts & Sciences Articles

In this paper we obtain a simple analytic formula for the photodetachment cross section of H− in parallel electric and magnetic fields. The three-dimensional semiclassical approximation predicts oscillations in the spectrum and correlates these oscillations with closed classical orbits. The cylindrical symmetry of the Hamiltonian produces some interesting effects. In particular, at boundary energies the semiclassical approximation fails as a focused cusp approaches the origin.

Quantum Manifestations Of Bifurcations Of Closed Orbits In The Photoabsorption Spectra Of Atoms In Electric Fields, J. Gao, John B. Delos

Arts & Sciences Articles

The methods developed in the preceding paper (paper II) are used to construct a wave function near a bifurcation of classical orbits of an atomic electron in an electric field. A formula for the recurrence strength near the bifurcation is derived and compared with experimental measurements.

Symmetry Breaking In Crossed Magnetic And Electric Fields, C. Neumann, R. Ubert, S. Freund, Et Al., John B. Delos

Arts & Sciences Articles

We present the first observations of cylindrical symmetry breaking in highly excited diamagnetic hydrogen with a small crossed electric field, and we give a semiclassical interpretation of this effect. As the small perpendicular electric field is added, the recurrence strengths of closed orbits decrease smoothly to a minimum, and revive again. This phenomenon, caused by interference among the electron waves that return to the nucleus, can be computed from the azimuthal dependence of the classical closed orbits.

Phenotypic Selection In An Intertidal Snail: Effects Of A Catastrophic Storm, G. Trussell

VIMS Articles

Littorina obtusata exhibits clear morphological variation (e.g. shell height, shell length, and aperture area) among shores differentially exposed to wave energies. Selection imposed by the hydrodynamic environment is often invoked to explain the correlation between morphology and wave exposure in intertidal organisms, but rarely is this hypothesis tested. I examined the effects of a catastrophic storm on the shell length and relative shell height and aperture area of L. obtusata populations on 2 protected and 1 wave-exposed share in New England (USA) to test this hypothesis. Snails sampled after the storm had relatively squatter shells than those sampled before the …

Geological And Geophysical Character Of The East China And Yellow Seas, John D. Milliman, Nicole D. Scott

Reports

The East China and Yellow seas represent one of the broadest shallow seas in the global ocean, with water depths generally less than 80 m and stretching nearly 750 km from the Shandong Peninsula to the Okinawa Trough (Fig. 1). This area is also unique in terms of the vast amount of sediment it receives from the Huanghe (Yellow River; presently discharging in the adjacent Gulf of Bohai) and the Changjigang (Yangtze River, which flows into the East China Sea). Together, this region receives about ten percent of the river-derived sediment reaching the ocean, and as such, the region has …

Status Of The Major Oyster Diseases In Virginia 1996 A Summary Of The Annual Monitoring Program, Lisa M. Ragone Calvo, Eugene M. Burreson

Reports

No abstract provided.

The Virginia Wetlands Report Vol. 12, No. 1, Virginia Institute Of Marine Science

Virginia Wetlands Reports

• Double-Crested Cormorant. Julie G. Bradshaw
• What is the Coastal Primary Sand Dune Protection Act? William Roberts
• Playing” Wetland Board is Excellent Learning Tool for Virginia Beach Students. Karla Schillinger
• Atlantic Silverside. Lyle Varnell
• GIS as an Educational Tool. Marcia Berman
• Medicinal Uses of Wetlands. Pam Mason

1997 Gloucester Point Station Tide Prediction Calendars, Virginia Institute Of Marine Science, David A. Evans

Miscellaneous

These calendars are produced monthly using David Evans' Tidecal.

Effects Of Seagrass Biology On Water Quality In Shallow Regions Of The Lower Chesapeake Bay : Final Report, Kenneth A. Moore

Reports

The changes in water quality within shallow water regions of the lower Chesapake Bay was compared seasonally from permanent stations located along transects across vegetated and unvegetated sites in shoal regions of the lower Chesapeake Bay. The effect of the seagrass bed on conditions inside compared to outside of the bed varied seasonally and could be related to bed biomass and develoment. During spring (April-June) the rapidly growing seagrass bed was a sink for nutrients, suspended inorganic particles and phytoplankton, while during the summer, as bed dieback progressed, resuspension and release of nutrients were observed. Reductions in suspended particle concentrations …

1997 Hampton Roads Station Tide Prediction Calendars, Virginia Institute Of Marine Science, David A. Evans

Miscellaneous

These calendars are produced monthly using David Evans' Tidecal.

Chesapeake Bay Hall Dedication, Virginia Institute Of Marine Science, School Of Marine Science, College Of William And Mary

Miscellaneous

Dedication: April 25, 1997. Invitation to dedication ceremony and program booklet. List of research laboratories provided.

1997 Wachapreague Station Tide Prediction Calendars, Virginia Institute Of Marine Science, David A. Evans

Miscellaneous

These calendars are produced monthly using David Evans' Tidecal.

The Selective Oxidation Of Beta-Cyclodextrin On The Secondary Face, Christine Evelyn Heath

Dissertations, Theses, and Masters Projects

No abstract provided.

Storm Surges In The Region Of Western Alaska, Warren Blier, Stanley Keefe, Wilson A. Shaffer, Sung C. Kim

VIMS Articles

Within the period of the historical record there have been several occurrences of extensive damage from storm-surge-related coastal flooding in the region of Nome, Alaska. The most recent of these events, although by no means the most destructive, occurred in association with the storm of 5–6 October 1992. Despite the small population of Nome (approximately 4000 people), total damage costs exceeded $6 million.

The research into the nature and causes of such flooding events has focused on this October 1992 case. The authors have, however, also examined a weaker, shorter-duration event that occurred on 20 August 1993 and, for contrast, …