Physical Sciences and Mathematics Commons^™

Learning From Lionfish: Modeling Marine Invaded Systems, Matthew Johnston

Mathematics Colloquium Series

Simulating marine invaded systems requires broad consideration of physical oceanographic processes, such as ocean circulation patterns and temperature, and biological traits of the invader, such as their reproductive strategy and tolerances to their environment. Through this understanding of baseline biological and oceanographic function, models can be developed in order to forecast the incursion patterns of marine invasive species - helpful both to predict their spread as well as forewarn of impacts. To facilitate this understanding, computer simulation is useful in order to quickly and efficiently assimilate large biological and oceanographic datasets into digestible products. Data derived from such simulations are …

The Quasi-Static Deformation, Failure, And Fracture Behavior Of Titanium Alloy Gusset Plates Containing Bolt Holes, Therese Hurtuk, Craig Menzemer, Anil Patnaik, Tirumalai Srivatsan, Kannan Manigandan, T. Quick

Craig Menzemer

In this article, the influence of bolt holes, specifically their number and layout on strength, deformation, and final fracture behavior of titanium alloy gusset plates under the influence of an external load is presented and discussed. Several plates having differences in both the number and layout of the bolt holes were precision machined and then deformed under quasi-static loading. The specific influence of number of bolt holes and their layout on maximum load-carrying capability and even fracture load was determined. The conjoint influence of bolt number, bolt layout pattern, nature of loading, contribution from local stress concentration, and intrinsic microstructural …

Cave Monitoring And The Potential For Palaeoclimate Reconstruction From Cueva De Asiul, Cantabria (N. Spain), Andrew C. Smith, Peter M. Wynn, Philip A. Barker, Melanie J. Leng, Steve R. Noble, Andrew Stott

International Journal of Speleology

Palaeoclimate records from northern Iberia are becoming increasingly sought after as this region is one of the most southerly terrestrial locations in Europe to have its climate dictated principally by the North Atlantic. Terrestrial records therefore have the potential to offer insights into changing oceanic and atmospheric circulation in the wider North Atlantic region. Cave speleothems offer one of the most promising archives from northern Iberia due to their wide geographic distribution and potential for accurately dated climate reconstruction. Cueva de Asiul, situated in Cantabria (N. Iberia; 43°19'0.63''N, 3°35'28.32''W; 285 m.a.s.l) within the Matienzo karst depression is one such site …

Two Distinct Modes Of Metal Ion Binding In The Nuclease Active Site Of A Viral Dna-Packaging Terminase: Insight Into The Two-Metal-Ion Catalytic Mechanism, Haiyan Zhao, Zihan Lin, Anna Y. Lynn, Brittany Varnado, John A. Beutler, Ryan P. Murelli, Stuart F.J. Le Grice, Liang Tang

Publications and Research

Many dsDNA viruses encode DNA-packaging terminases, each containing a nuclease domain that resolves concatemeric DNA into genome-length units. Terminase nucleases resemble the RNase H-superfamily nucleotidyltransferases in folds, and share a two-metal-ion catalytic mechanism. Here we show that residue K428 of a bacteriophage terminase gp2 nuclease domain mediates binding of the metal cofactor Mg2+. A K428A mutation allows visualization, at high resolution, of a metal ion binding mode with a coupled-octahedral configuration at the active site, exhibiting an unusually short metal-metal distance of 2.42 A° . Such proximity of the two metal ions may play an essential role in catalysis by …

Analyzing And Organizing The Sonic Space Of Vocal Imitation, Davide Andrea Mauro Phd, D. Rocchesso

Computer Sciences and Electrical Engineering Faculty Research

The sonic space that can be spanned with the voice is vast and complex and, therefore, it is difficult to organize and explore. In order to devise tools that facilitate sound design by vocal sketching we attempt at organizing a database of short excerpts of vocal imitations. By clustering the sound samples on a space whose dimensionality has been reduced to the two principal components, it is experimentally checked how meaningful the resulting clusters are for humans. Eventually, a representative of each cluster, chosen to be close to its centroid, may serve as a landmark in the exploration of the …

Relativistic Elastic Differential Cross Sections For Equal Mass Nuclei, Charles M. Werneth, Khin M. Maung, W.P. Ford

Faculty Publications

The effects of relativistic kinematics are studied for nuclear collisions of equal mass nuclei. It is found that the relativistic and non-relativistic elastic scattering amplitudes are nearly indistinguishable, and, hence, the relativistic and non-relativistic differential cross sections become indistinguishable. These results are explained by analyzing the Lippmann–Schwinger equation with the first order optical potential that was employed in the calculation.

Disorder Influences The Quantum Critical Transport At A Superconductor-To-Insulator Transition, H Q. Nguyen, Shawna M. Hollen, J M. Valles Jr., J Shainline, J. M. Xu

Physics & Astronomy

We isolated flux disorder effects on the transport at the critical point of the quantum magnetic field tuned superconductor-to-insulator transition (BSIT). The experiments employed films patterned into geometrically disordered hexagonal arrays. Spatial variations in the flux per unit cell, which grow in a perpendicular magnetic field, constitute flux disorder. The growth of flux disorder with magnetic field limited the number of BSITs exhibited by a single film due to flux matching effects. The critical metallic resistance at successive BSITs grew with flux disorder contrary to predictions of its universality. These results open the door for controlled studies of disorder effects …

Chemistry And Biochemistry News, Georgia Southern University

Department of Chemistry and Biochemistry News (2015-2023)

• Faculty members from Chemistry and Biology Department Recived a Sustainability Fee Grant
• Teaching Scholarship

• CEMITURE 2015- Research Experience for Undergraduates

A Generalized Force-Modified Potential Energy Surface For Mechanochemical Simulations, Gopinath Subramanian, Nithin Mathew, Jeff Leiding

Faculty Publications

We describe the modifications that a spatially varying external load produces on a Born-Oppenheimer potential energy surface (PES) by calculating static quantities of interest. The effects of the external loads are exemplified using electronic structure calculations (at the HF/6-31G- level) of two different molecules: ethane and hexahydro-1,3,5-trinitro-s-triazine (RDX). The calculated transition states and Hessian matrices of stationary points show that spatially varying external loads shift the stationary points and modify the curvature of the PES, thereby affecting the harmonic transition rates by altering both the energy barrier as well as the prefactor. The harmonic spectra of both molecules are blueshifted …

Formal Models Of The Extension Activity Of Dna Polymerase Enzymes, Srujan Kumar Enaganti

Electronic Thesis and Dissertation Repository

The study of formal language operations inspired by enzymatic actions on DNA is part of ongoing efforts to provide a formal framework and rigorous treatment of DNA-based information and DNA-based computation. Other studies along these lines include theoretical explorations of splicing systems, insertion-deletion systems, substitution, hairpin extension, hairpin reduction, superposition, overlapping concatenation, conditional concatenation, contextual intra- and intermolecular recombinations, as well as template-guided recombination.

First, a formal language operation is proposed and investigated, inspired by the naturally occurring phenomenon of DNA primer extension by a DNA-template-directed DNA polymerase enzyme. Given two DNA strings u and v, where the shorter …

High Resolution Tropospheric Studies With An Mst Type Radar, Marcial Garbanzo-Salas

Electronic Thesis and Dissertation Repository

Applications and results of a variety of studies carried out with the Costa Rican VHF profiler radar are included. This radar is unique because of the wide frequency bandwidth available (5 MHz). During the developing stages of the wind profiler radar new techniques of processing and radar engineering were used.

A thorough analysis of a data-dependent method (Capon's) commonly used in radar was carried out. This method is analyzed based on a reference established by Fourier theory. Disadvantages of using data-dependent methods with small filters were found. A small filter size will cause Capon's method to underestimate the number of …

(Under)Mining The Seabed? Between The International Seabed Authority Mining Code And Sustainable Bioprospecting Of Hydrothermal Vent Ecosystems In The Seabed Area: Taking Precaution Seriously, Ikechi Mgbeoji

Ikechi Mgbeoji

Rapid developments in marine biotechnology and the prospect of sea-bed mining have exposed the inadequacy of legal frameworks to regulation the exploration exploitation, and sharing of the benefits that arise from such marine endeavors. The fact of the matter is that despite the giant strides made in and the huge financial stakes involved in bioprospecting of hydro-thermal vent ecosystems, legal issues raised by profitable biotechnology development through marine scientific research (MSR) are still at an infant and underdeveloped stage. This article evaluates the extent to which the present legal order for the mining of seabed polymetallic nodules with its tangential …

U.S. Drought Monitor, October 6, 2015, David Miskus

United States Agricultural Commodities in Drought Archive

Drought map of U.S. for October 6, 2015 (10/6/15) plus: U.S. crop areas experiencing drought (map), Approximate percentage of crop located in drought, by state (bar graph), Percent of crop area located in drought, past 52 weeks (line graph) for: Corn, Soybeans, Hay, Cattle, Winter wheat.

Highly Selective Hydrogenation And Hydrogenolysis Using A Copper-Doped Porous Metal Oxide Catalyst, Laurene Petitjean, Raphael Gagne, Evan Beach, Dequan Xiao, Paul Anastas

Chemistry and Chemical Engineering Faculty Publications

A copper-doped porous metal oxide catalyst in combination with hydrogen shows selective and quantitative hydrogenolysis of benzyl ketones and aldehydes, and hydrogenation of alkenes. The approach provides an alternative to noble-metal catalysed reductions and stoichiometric Wolff-Kishner and Clemmensen methods.

Discovery Of An Apparent High Latitude Galactic Supernova Remnant, Robert A. Fesen, Jack M. M. Neustadt, Christine S. Black, Ari H. D. Koeppel

Dartmouth Scholarship

Deep Hα images of a faint emission complex 4.0 x 5.5 degrees in angular extent and located far off the Galactic plane at l = 70.0 degrees, b=-21.5 degrees reveal numerous thin filaments suggestive of a supernova remnant's shock emission. Low dispersion optical spectra covering the wavelength range 4500 - 7500 A show only Balmer line emissions for one filament while three others show a Balmer dominated spectrum along with weak [N I] 5198, 5200 A, [O I] 6300, 6364 A, [N II] 6583 A, [S II] 6716, 6731 A and in one case [O III] 5007 A line emission. …

A Coordinated Study Of 1-H Mesoscale Gravity Waves Propagating From Logan To Boulder With Crrl Na Doppler Lidars And Temperature Mapper, Xian Liu, Cao Chen, Wentao Huang, John A. Smith, Xinzhao Chu, Tao Yuan, Pierre-Dominique Pautet, Michael J. Taylor, Jie Gong, Chihoko Y. Cullens

Publications

We present the first coordinated study using two lidars at two separate locations to characterize a 1 h mesoscale gravity wave event in the mesopause region. The simultaneous observations were made with the Student Training and Atmospheric Research (STAR) Na Doppler lidar at Boulder, CO, and the Utah State University Na Doppler lidar and temperature mapper at Logan, UT, on 27 November 2013. The high precision possessed by the STAR lidar enabled these waves to be detected in vertical wind. The mean wave amplitudes are ~0.44 m/s in vertical wind and ~1% in relative temperature at altitudes of 82–107 km. …

Geometric Approach To Convex Subdifferential Calculus, Boris S. Mordukhovich, Nguyen Mau Nam

Mathematics and Statistics Faculty Publications and Presentations

In this paper, we develop a geometric approach to convex subdifferential calculus in finite dimensions with employing some ideas of modern variational analysis. This approach allows us to obtain natural and rather easy proofs of basic results of convex subdifferential calculus in full generality and also derive new results of convex analysis concerning optimal value/marginal functions, normals to inverse images of sets under set-valued mappings, calculus rules for coderivatives of single-valued and set-valued mappings, and calculating coderivatives of solution maps to parameterized generalized equations governed by set-valued mappings with convex graphs.

Using Future Benefits To Set Conservation Priorities For Wetlands, Samuel B. Merrill

Journal of Ocean and Coastal Economics

In an era of rising sea levels, costal land managers including land trust representatives, municipal planners, and others contributing to decisions about whether to develop or protect coastal parcels do not have viable means of evaluating future values on wetlands that will be created when sea levels rise. This project develops and tests a software modeling approach to help address this issue, in combination with a novel, expert-opinion driven benefit-cost framework. The beta test used three parcels in Scarborough, Maine: Hampton Circle, Maine Audubon, and Pine Point. It used a group of experts to 1) allocate initial values to these …

Artificial Reef Attributes And The Relationship With Natural Reefs: Evidence From The Florida Keys, William L. Huth, O. Ashton Morgan, Paul Hindsley

Journal of Ocean and Coastal Economics

Natural or coral reefs represent extremely valuable ecosystems supporting an estimated 25 percent of all marine life, yet recent reports suggest that 75 percent of the world’s natural reefs are under threat from both natural and human stressors. In areas such as the Florida Keys that boasts an expansive mix of natural and artificial reefs, recreational diving on the system provides an important economic contribution to the local community but also potentially contributes to the stress of the existing natural reef system. We develop a revealed and stated preference modeling framework of diver behavior and find that deployment of an …

Economic Valuation Of Marine And Coastal Ecosystems: Is It Currently Fit For Purpose?, Nick Hanley, Stephen Hynes, David Patterson, Niels Jobstvogt

Journal of Ocean and Coastal Economics

In this paper, we consider whether the current “state of the art” of environmental valuation is suitable for producing policy-relevant estimates of the benefits or costs of changes in marine and coastal ecosystems. We review recent changes in European legislation which has meant an increasing demand for economic valuation from the policy and regulatory community. The next section considers, at a more conceptual level, whether the economic “toolbox” and scientific evidence is up to the task of meeting the demand for more evidence-based policy. Finally, three case studies are used to explore the nature of the valuation task and review …

Simulation Experiment Of Disaster Response Organizational Structures With Alternative Optimization Techniques, Geun Lee, Jang Bae, Namkyung Oh, Jeong Hong, Il-Chul Mood

Namkyung Oh

Disaster response operations are critical for decreasing the devastating impacts that result in casualties and property damages. Since these operations require cooperation in dynamic and complex situations, the responding organizations require a solid organizational structure collectively. This article introduces computational designs and evaluations of alternative organizational structures for disaster responses to resolve the disconnections between resource demands and supplies. In particular, this research consists of (1) organizational structure designs with two optimization techniques, (2) agent-based simulations that virtually replicate disaster response contexts, and (3) social network analysis to interpret the relations between the structures and the performances from the network …

Cave Development In An Uplifting Fold-And-Thrust Belt Of The Tatra Mountains, Poland, Jacek Szczygieł

International Journal of Speleology

Detailed structural analysis and geomorphological observations supplemented by the analysis of the distribution of karst conduit directions have been performed in 23 morphologically diverse caves in the Tatra Mountains. Based on these studies, a development scheme of vadose cave passages has been proposed for the most common geological settings in the fold-and-thrust-belt: (1) single-plain faults, (2) multiple fault cores, (3) bedding plane fractures and (4) hinge zones of recumbent folds. Results indicate that the dynamics of the massif (local gravity sliding in the nearby slope zone and regional stress fields), along with the structural pattern, influences the predisposition of structural …

Fluctuating Fire Regimes And Their Historical Effects On Genetic Variation In An Endangered Shrubland Specialist, Hernan Vázquez-Miranda, Kelly R. Barr, C. Craig Farquhar, Robert M. Zink

School of Natural Resources: Faculty Publications

The Pleistocene was characterized by worldwide shifts in community compositions. Some of these shifts were a result of changes in fire regimes, which influenced the distribution of species belonging to fire-dependent communities. We studied an endangered juniper–oak shrubland specialist, the black-capped vireo (Vireo atricapilla). This species was locally extirpated in parts of Texas and Oklahoma by the end of the 1980s as a result of habitat change and loss, predation, brood parasitism, and anthropogenic fire suppression. We sequenced multiple nuclear loci and used coalescence methods to obtain a deeper understanding of historical population trends than that typically available …

Sun-Like Magnetic Cycles In The Rapidly Rotating Young Solar Analog Hd 30495, Ricky Egeland, Travis S. Metcalfe, Jeffrey C. Hall, Gregory W. Henry

Information Systems and Engineering Management Research Publications

A growing body of evidence suggests that multiple dynamo mechanisms can drive magnetic variability on different timescales, not only in the Sun but also in other stars. Many solar activity proxies exhibit a quasi-biennial (∼2 year) variation, which is superimposed upon the dominant 11 year cycle. A well-characterized stellar sample suggests at least two different relationships between rotation period and cycle period, with some stars exhibiting long and short cycles simultaneously. Within this sample, the solar cycle periods are typical of a more rapidly rotating star, implying that the Sun might be in a transitional state or that it has …

Initiatives In Using Crowdsourcing, Satellite Derived Bathymetry, And Other Non-Traditional Hydrographic/Bathymetric Measurements, Anthony Klemm, Shachak Pe'eri, John Nyberg

Center for Coastal and Ocean Mapping

No abstract provided.

Stress Granules Modulate Syk To Cause Microglial Cell Dysfunction In Alzheimer's Disease, Soumira Ghosh, Robert Geahlen

Department of Medicinal Chemistry and Molecular Pharmacology Faculty Publications

Microglial cells in the brains of Alzheimer's patients are known to be recruited to amyloid-beta (Aβ) plaques where they exhibit an activated phenotype, but are defective for plaque removal by phagocytosis. In this study, we show that microglia stressed by exposure to sodium arsenite or Aβ(1–42) peptides or fibrils form ex- tensive stress granules (SGs) to which the tyrosine kinase, SYK, is recruited. SYK enhances the formation of SGs, is active within the resulting SGs and stimulates the production of reactive oxygen and nitrogen species that are toxic to neuronal cells. This sequestration of SYK inhibits the ability of microglial …

Information Security Newsletter

Information Security Newsletter

No abstract provided.

Temporal Variation In Optical Properties Of Chromophoric Dissolved Organic Matter (Cdom) In Southern California Coastal Waters With Nearshore Kelp And Seagrass, Catherine D. Clark, Warren J. De Bruyn, Paige Aiona

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Optical properties of chromophoric dissolved organic matter (CDOM) were measured in surf zone waters in diurnal field studies at a Southern California beach with nearshore kelp and seagrass beds and intertidal plant wrack. Absorption coefficients (aCDOM(300 nm)) ranged from 0.35 m21 to 3.7 m21 with short-term variability<1 h, increases at ebb and flood tides and higher values (6 m21) during an offshore storm event. Spectral slopes (S) ranged from 0.0028 nm21 to 0.017 nm21, with higher values after the storm; S was generally inversely correlated with aCDOM(300 nm). 3-D excitation–emission matrix spectra (EEMs) for samples with lower S values had humic-type peaks associated with terrestrial material (A, C), marine microbial material (M) and protein peaks, characteristic of freshly produced organic material. Samples with high S values had no or reduced protein peaks, consistent with aged material. Fluorescent indexes (f450/f500 >2.5, BIX>1.1) were consistent with microbial aquatic sources. Leachates of senescent kelp and seagrass had protein and humic-type EEM peaks. After solar simulator irradiation (4 h), protein peaks rapidly photochemically degraded, humic-type peak C increased in intensity and peak M disappeared. Optical characteristics of kelp leachates were most similar to field samples, …

Isotopic Abundance Analysis Of Biofield Treated Benzene, Toluene And P-Xylene Using Gas Chromatography-Mass Spectrometry (Gc-Ms), Mahendra Trivedi, Alice Branton, Dahryn Trivedi, Gopal Nayak, Gunin Saikia, Snehasis Jana

Mahendra Kumar Trivedi

Using An Agent-Based Model To Study The Effect Of Reproductive Skew On Mongoose Populations, Stacy Lee Mowry

Theses and Dissertations

Reproductive skew is the name given to the unequal partitioning of breeding

within social groups. Within these groups a mating hierarchy emerges wherein one dominant mating pair holds an unproportional majority of the group's reproductive benefit, while other members mate infrequently, yet allocate energy and resources toward the offspring of the dominant group members. In this paper, we use an agent-based model, which mimics dwarf and banded mongoose populations, to investigate how reproductive skew aftects the speed natural selection, and thus how reproductive skew affects fitness. The results of the model show that due to the geometric structure of skewed …