Digital Commons Network^™

Computational Study Of A Novel Dinuclear Metal Complex, Dragos Seghete

Inquiry: The University of Arkansas Undergraduate Research Journal

The first compound containing an M-H-M was recently reported by Vicic et al. With recent availability of large computational resources, molecular modeling has become a reliable tool for confirming experimental results. The novel dinuclear Ni complex [( dippm)2Ni2Br2]( 0 -H) was investigated in this work from a theoretical perspective. Full geometry optimization was carried on the dinuclear Ni complex at the DFT/B3LYP with the 6-31G* basis set. The result verifies the linear Ni-H-Ni bond. Two different starting structures that converged to the same geometry confirm that a global minimum was reached. The computed structure differs from the experimentally determined one …

Foreword, Murray Smart Jr.

Inquiry: The University of Arkansas Undergraduate Research Journal

No abstract provided.

Milestone 2005, Hope College

Milestone

Milestone, the Hope College yearbook, is an annual publication of Hope College. The first yearbook was published in 1905 as a single edition and was titled The Hope College Annual. The yearbooks became an annual publication in 1916, which was also when it was titled Milestone.

Stress Enhancement Of Craving During Sobriety: A Risk For Relapse, Laura O'Dell

Departmental Papers (Psych)

No abstract provided.

Lady Razorbacks 20th Anniversary, 2005, University Of Arkansas, Fayetteville. Athletics Media Relations, University Of Arkansas, Fayetteville. Women's Athletics Department. Women's Communications Office, University Of Arkansas, Fayetteville. Women's Athletics Department. Women's Sports Information Office

Arkansas Soccer

No abstract provided.

Illusions Of Liberty And Equality: An "Alien's" View Of Tiered Scrutiny, Ad Hoc Balancing, Governmental Power, And Judicial Imperialism, Michael A. Scaperlanda

Catholic University Law Review

No abstract provided.

Phenylalanine Ammooia-Lyase, Buchholz Brown Jr.

Opportunities for Undergraduate Research Experience Program (OURE)

Phenylalanine ammonia-lyase (PAL), the first enzyme in the phenylpropanoid pathway, acts a key control point in this complex pathway and is known to consist of a gene family. The goal of this study was to isolate members of the PAL gene family using gene specific primers. But before this could be accomplished, controls had to be prepared using previously made primers and known PAL gene family members. The plasmid control, at approximately 500 base pairs, has been created and the genomic DNA control is still in the process of being worked out. Once the genomic DNA control has been finalized, …

Effects Of Nitric Oxide Inhibitors And Scavengers On Gravitropism In Arabidopsis Thaliana, Kristin Russell, Jennifer Jacobi, Jacob Elmore

Opportunities for Undergraduate Research Experience Program (OURE)

No abstract provided.

A Hydrogen Economy, Jeremy Snyder

Opportunities for Undergraduate Research Experience Program (OURE)

In 2003, MIT released "The Future of Nuclear Power," a study of the energy needs for now and the future. The report suggested several subsidies and a new "carbon tax." Also in 2003, President Bush made a State of the Union address that pledged more than a billion dollars towards hydrogen research and a move towards a hydrogen-based economy. This report strives to tie together several hydrogen production methods and possible solutions for moving towards a hydrogen-based economy. Background, production methods, and finally a revised carbon tax idea specifically aimed at jumpstarting hydrogen production are addressed in this report.

Bioactive Glass Coatings For Adherence To Bone Tissue, Wesley Trueblood

Opportunities for Undergraduate Research Experience Program (OURE)

The purpose of the experiments for this research project was to determine whether certain compositions of borate-based glasses are bioactive and can be used to bond titanium pins to bone. Two different major experiments were done. The first experiment was done to determine the bioactivity of the glass. The second experiment was done to simultaneously determine the bioactivity of the glass and determine whether or not the glass would bind to titanium and bone.

The majority of the research consisted of working with different compositions of borate-based glass, making glass pins, and coating titanium pins with the glass. The making …

Exploration Of Various Techniques For Quantitative Detection Of Antibodies In Solution, Tom Fennewald

Opportunities for Undergraduate Research Experience Program (OURE)

We have continued our development of a biosensor and are developing new methods of antigen detection. A fluorometer was previously constructed and was shown to have the ability of quantitatively detecting the amount of fluorescence of fluorescent beads purchased from Molecular Probes. This ability thus corresponds to an ability to quantitate the amount of fluorescent beads which are in solution. Difficulties arose in attaching protein to these beads by the method given by molecular probes and this problem was examined using UV-Vis spectroscopy. Amongst other proposed approaches to antigen detection, one most attachment of antibody lo gold so that antigen …

Effect Of Phosphodiesterase Inhibitors And Dibutyryl Cgmp On Gravitropism In Arabidopsis Thaliana, Jacob James Elmer, Jen Jacobi, Kristine Russell

Opportunities for Undergraduate Research Experience Program (OURE)

Plant roots always orient themselves in the direction of the force of gravity. When reoriented 90 degrees, seedling roots were observed to respond by reorienting their root tips in the same fashion and then growing in that direction. The mechanism for this response, as suggested by Pagnussat et al. (2003)¹, is initiated by nitric oxide and results in cGMP production. When we exposed A. thaliana seedling roots to cGMP, those roots reoriented quicker than control roots. The roots were also exposed to phosphodiesterase inhibitors (drugs that prevent the natural degradation of cGMP), which sensitized the roots to the …

Lead Tolerant Bacteria Could Be The Future Of Bioremediation, Kendra Waltermire

Opportunities for Undergraduate Research Experience Program (OURE)

The contamination of soil, sediment, and water by toxic metals is a major problem worldwide, both environmentally, and economically. Microorganisms that are resistant to lead are rare in nature. Lead is toxic to most microorganisms and only a few have developed mechanisms to survive in this toxic environment In this study, bacteria found in soil and water with high concentrations of soluble lead are isolated and characterized. I grew and isolated bacteria that are resistant to the lead found in the solid medium. A gram stain was used to characteristically determine the bacteria that were isolated. Four isolated bacteria were …

Deep Western Boundary Current East Of Abaco: Mean Structure And Transport, Harry L. Bryden, William E. Johns, Peter M. Saunders

Journal of Marine Research

To assess whether the southward deep water flow of the Atlantic meridional overturning circulation can be monitored by measuring the deep western boundary current, the structure and transport of the time-averaged deep western boundary current at 26.5N are estimated from long current meter records deployed in a series of 7 mooring deployments over 11 years from March 1986 to June 1997 east of Abaco Island in the Bahamas. Time-averaged meridional velocities for each current meter record are combined into estimates of mean velocity at 3 to 10 depths at 10 mooring locations extending eastward from the continental slope out to …

Interannual Variations In Upper-Ocean Transport By The Gulf Stream And Adjacent Waters Between New Jersey And Bermuda, T. Rossby, C. N. Flagg, K. Donohue

Journal of Marine Research

Since the fall of 1992, an acoustic Doppler current profiler mounted on a freighter, the CMV Oleander, has been measuring upper-ocean currents between New Jersey and Bermuda on a weekly basis. The extensive database that results from the frequent, systematic, and sustained sampling enables the exploration of a number of questions regarding currents in the northwest Atlantic. This paper reports on interannual variations in transport in the Gulf Stream and adjacent waters. The repeat sampling greatly increases the ability to discern even rather subtle variations in near-surface transport and explore their possible causes. The transect is divided into three subregions: …

Decadal Changes In The Canary Upwelling System As Revealed By Satellite Observations: Their Impact On Productivity, A. Miguel P. Santos, Alexander S. Kazmin, Álvaro Peliz

Journal of Marine Research

Satellite-derived sea-surface temperature (SST) data were used to study the variability of the Canary Upwelling Ecosystem-CUE (12 to 43N) over the last two decades of the 20^th century. The analysis reveals well known patterns of climatology and seasonal variability in this upwelling system. In contrast to quasi-regular decadal oscillations of SST anomalies observed in the open ocean, the coastal variability during the 1980s–1990s was better described as a decadal scale shift of the upwelling regime intensity. The analysis of the upwelling index and coastal zonal gradient of SST showed that this shift occurred earlier (∼1992) in the northern part …

Recruitment Responses Of Benthic Infauna To Manipulated Sediment Geochemical Properties In Natural Flows, Steven J. Engstrom, Roberta L. Marinelli

Journal of Marine Research

Recent studies have shown that local variation in surface sediment geochemistry can have significant effects on recruitment rates of benthic invertebrates. Experiments presented here tested (1) the utility of manipulating surface porewater concentrations using spiked polyacrylamide gels and (2) the recruitment responses of the polychaete Arenicola cristata and the bivalve Mercenaria mercenaria to manipulated ammonium concentrations in realistic flows provided by a straight flume and an annular flume. Data show that successful manipulation of sediment porewater ammonium concentration is feasible in flowing waters, i.e., overlying waters remained relatively free of ammonium while manipulated concentration levels were maintained within the upper …

The Physics Of Blue Crab Larval Recruitment In Delaware Bay: A Model Study, Charles E. Tillburg, John T. Reager, Michael M. Whitney

Journal of Marine Research

Recent studies have shown that the tidal-, wind- and buoyancy-driven surface currents govern the transport of blue crab (Callinectes sapidus) larvae within the coastal ocean and estuaries. Here, we develop a model of larval transport within Delaware Bay and the adjoining coastal ocean using a particle advection scheme coupled to a previously validated physical circulation model which includes realistic tidal forcing, bottom bathymetry, wind stress and river discharge. The coupled model is then used to quantify the effects of several mechanisms on larval transport and recruitment in this region and hindcast actual larval settlement for a four-year period.The …

Mixing Within The Interior Of The Faeroe-Shetland Channel, Phil Hosegood, Hans Van Haren, Cornelis Veth

Journal of Marine Research

Observations of the distribution of the density field, the dissipation rate of turbulent kinetic energy, ε, the vertical diffusivity, K_z, and optical backscatter over a repeated cross-section of the Faeroe-Shetland Channel (FSC) are presented within the context of ocean mixing. Turbulence in the permanent pycnocline occurs in discrete vertical patches of thickness 20–50 m coincident with layers of elevated vertical current shear magnitude, |S| > 10⁻² s⁻¹. The layers of elevated shear result from high-wavenumber internal waves which may break through shear instabilities as indicated by critical Richardson numbers, Ri < 1. The internal waves are ubiquitous features of strong boundary currents flowing along continental shelves and are likely generated here by geostrophic adjustment of the pycnocline in response to lateral excursions of the boundary current over the Shetland slope or by the scattering of internal tide energy. The pycnocline as a whole exhibits K_z > 10^−4.5 m^{2 …}

Statistical Inversion Of South Atlantic Circulation In An Abyssal Neutral Density Layer, Ian W. Mckeague, Geoff Nicholls, Kevin Speer, Radu Herbei

Journal of Marine Research

This paper introduces a Bayesian inversion approach to estimating steady state ocean circulation and tracer fields. It is based on a quasi-horizontal flow model and a PDE solver for the forward problem of computing solutions to the tracer field advection-diffusion equations. A typical feature of existing ocean circulation inverse methods is a preprocessing stage in which the tracer data are interpolated over a regular grid and the interpolation error is ignored in the subsequent inversion. Our approach only uses interpolated data at those grid points that have neighboring hydrographic stations. By exploiting physically-based models in an integrated fashion, the method …

Buoyancy-Forced Circulations In Shallow Marginal Seas, Michael A. Spall

Journal of Marine Research

The properties of water mass transformation and the thermohaline circulation in shallow marginal seas with topography and subject to surface cooling are discussed in the context of an eddy-resolving primitive equation model and an analytic planetary geostrophic model. A unique and important aspect of the model configuration is that the geostrophic contours, or characteristics of the system, extend from a region where temperature is restored toward a uniform value, providing a source of heat, through the cooling region. This removes a degree of symmetry that has often been imposed in previous studies of deep convection. The heat loss within the …

Lagrangian Spin Parameter And Coherent Structures From Trajectories Released In A High-Resolution Ocean Model, Milena Veneziani, Annalisa Griffa, Zulema D. Garraffo, Eric P. Chassignet

Journal of Marine Research

A study of the mesoscale eddy field in the presence of coherent vortices, by means of Lagrangian trajectories released in a high-resolution ocean model, is presented in this paper. The investigation confirms previous results drawn from real float data statistics (Veneziani et al., 2004) that the eddy field characteristics are due to the superposition of two distinct regimes associated with strong coherent vortices and with a typically more quiescent background eddy flow. The former gives rise to looping trajectories characterized by subdiffusivity properties due to the trapping effect of the vortices, while the latter produces nonlooping floats characterized by simple …

Two Coastal Upwelling Domains In The Northern California Current System, Adriana Huyer, Jane H. Fleischbein, Julie Keister, P. Michael Kosro, Natalie Perlin, Robert L. Smith, Patricia A. Wheeler

Journal of Marine Research

A pair of hydrographic sections, one north and one south of Cape Blanco at 42.9N, was sampled in five summers (1998–2000 and 2002–2003). The NH line at 44.6N lies about 130 km south of the Columbia River, and spans a relatively wide shelf off Newport, Oregon. The CR line at 41.9N off Crescent City, California, lies 300 km farther south and spans a narrower shelf. Summer winds are predominantly southward in both locations but the southward winds are stronger on the CR line. Sampling included CTD/rosette casts (to measure temperature, salinity, dissolved oxygen, nutrients, chlorophyll), zooplankton net tows and continuous …

Growth Rates Of Interface-Feeding Spionid Polychaetes In Simulated Tidal Currents, Brian T. Hentschel, Brenda S. Herrick

Journal of Marine Research

Most spionid polychaetes switch from surface deposit feeding to suspension feeding as current speed and the flux of suspended food increase. Previous experiments testing the effects of flow on the growth of facultative, interface feeders have been limited to very simplified flow regimes such as constant, unidirectional currents. To measure the growth of interface-feeding spionids in more realistic currents, we programmed two identical counter-rotating annular flumes to simulate two different semidiurnal tidal currents. Each regime included four speeds that varied in hourly steps. At 5 mm above bottom, speeds in the slower flow regime were 0, 2.5, 5, and 7.5 …

Analytical Solutions For The Acc And Its Overturning Circulation, Timour Radko

Journal of Marine Research

An explicit analytical model of the Antarctic Circumpolar Current (ACC) is presented in which the key feature is the balance between the Eulerian circulation acting to overturn the isopycnals and geostrophic eddies which tend to flatten them. Solutions for the stratification and overturning circulation are obtained by expanding the governing residual mean equations of motion in a small parameter (ε) which measures the relative strength of the surface buoyancy flux and mechanical forcing by winds. Our balanced asymptotic model extends and reconciles the earlier views on the dynamics of the (streamwise-averaged) ACC by demonstrating that the zero order balance between …

Parameterizations Of Lagrangian Spin Statistics And Particle Dispersion In The Presence Of Coherent Vortices, Milena Veneziani, Annalisa Griffa, Andy M. Reynolds, Zulema D. Garraffo, Eric P. Chassignet

Journal of Marine Research

Coherent vortices are known to play an important role in transport processes of ideal flows such as two-dimensional and quasi-geostrophic turbulent flows. In this paper, their effect on eddy dispersion and diffusivity is studied in a realistic oceanic flow, using synthetic Lagrangian data simulated within a high-resolution ocean general circulation model in the Gulf Stream recirculation region. The possibility of using a Lagrangian Stochastic Model (LSM) with nonzero mean spin statistic, Ω, to parameterize the observed characteristics is considered. The probability distribution of the Ω parameter (which is representative of the looping behavior of trajectories embedded inside the coherent vortices) …

Sex Offenders: Pariahs Of The 21st Century?, Luis Rosell

William Mitchell Law Review

No abstract provided.

Early Assessment And Intervention In Educational Disadvantage, Laura Hanlon

Reports

Research report commissioned by the Centre for Early Childhood Development and Education, October, 2005.

Design Of Mobile Phone Applications For Point-Of-Care Test Result Validation., John Mcgrory, Owen Lynch, Eugene Coyle

Conference Papers

Patients with many different conditions are required to take the management of their condition into their own hands and perform Point of Care Testing (POCT) at home. However, this raises quality control issues that would not arise in a clinical setting, since the sample acquisition and testing procedures are not overseen by professional hospital staff. Another major issue, the main focus of this research, is that results from such tests are not clinically validated to ensure that they are plausible for that patient at the time of testing. In hospital, tests taken by clinicians are validated by hi-tech computerised validation …

320-Channel Dual Phase Lock-In Optical Spectrometer, Petru S. Fodor, S. Rothenberger, J. Levy

Physics Faculty Publications

The development of a multiple-channel lock-in optical spectrometer (LIOS) is presented, which enables parallel phase-sensitive detection at the output of an optical spectrometer. The light intensity from a spectrally broad source is modulated at the reference frequency, and focused into a high-resolution imaging spectrometer. The height at which the light enters the spectrometer is controlled by an acousto-optic deflector, and the height information is preserved at the output focal plane. A two-dimensional InGaAs focal plane array collects light that has been dispersed in wavelength along the horizontal direction, and in time along the vertical direction. The data is demodulated using …