Digital Commons Network^™

Productivity-Diversity Relationships From Chemolithoautotrophically Based Sulfidic Karst Systems, Megan L. Porter, Annette Summers Engel, Thomas C. Kane, Brian K. Kinkle

International Journal of Speleology

Although ecosystems thriving in the absence of photosynthetic processes are no longer considered unique phenomena, we have yet to understand how these ecosystems are energetically sustained via chemosynthesis. Ecosystem energetics were measured in microbial mats from active sulfidic caves (Movile Cave, Romania; Frasassi Caves, Italy; Lower Kane Cave, Wyoming, USA; and Cesspool Cave, Virginia, USA) using radiotracer techniques. We also estimated bacterial diversity using 16S rRNA sequences to relate the productivity measurements to the composition of the microbial communities. All of the microbial communities investigated were dominated by chemolithoautotrophic productivity, with the highest rates from Movile Cave at 281 g …

Exploring The Secrets Of The Three-Dimensional Architecture Of Phototrophic Biofilms In Caves, Mònica Roldán, Mariona Hernández-Mariné

International Journal of Speleology

Caves with dim natural light, and lighted hypogean environments, have been found to host phototrophic microorganisms from various taxonomic groups. These microorganisms group themselves into assemblies known as communities or biofilms, which are associated with rock surfaces. In this work, the phototrophic biofilms that colonise speleothems, walls and floors in three tourist caves (Spain) were studied. Confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM) were used to study these organisms and acquire three-dimensional data on their biofilm structure. CLSM was used in a multi-channel mode whereby the different channels map individual biofilm components. Cyanobacteria, green microalgae, diatoms, mosses …

Lights And Shadows On The Conservation Of A Rock Art Cave: The Case Of Lascaux Cave, Fabiola Bastian, Claude Alabouvette

International Journal of Speleology

Lascaux Cave was discovered in 1940. Twenty years after the first microbial contamination signs appeared. In the last forty years the cave suffered different fungal invasions. Here we discuss the past, present and future of the cave and the conservation of its rock art paintings to the light of data obtained using culture-dependent and –independent methods.

Sediment Flushing In Mystic Cave, West Virginia, Usa, In Response To The 1985 Potomac Valley Flood, James J. Van Gundy, William B. White

International Journal of Speleology

The great November 5, 1985 Potomac Valley flood was responsible for the release of 1800 m³ of alluvial and colluvial sediment from the walls of the entrance doline of Mystic Cave. Flood waters were sufficiently powerful to flush the entire mass of sediment not only into the cave but through the cave. Remnants of the sediment mass in the form of sand bars and a few cobbles wedged in speleothems were the only evidence in the cave that the huge mass of sediment had moved through. The sediment moved as a suspended mass in water moving at peak velocities …

Cottonballs, A Unique Subaqeous Moonmilk, And Abundant Subaerial Moonmilk In Cataract Cave, Tongass National Forest, Alaska, Megan D. Curry, Penelope J. Boston, Mike N. Spilde, James F. Baichtal, Andrew R. Campbell

International Journal of Speleology

The Tongass National Forest is known for its world-class karst features and contains the largest concentration of dissolutional caves in Alaska. Within these karst systems exist unusual and possibly unique formations exhibiting possible biological origin or influence. Cataract Cave is an example of such a system. This cave hosts a unique depositional setting in which so-called “cottonballs” line two permanent pools. The cottonballs are a calcitic deposit heavily entwined within a mass of microbial filaments. They are juxtaposed with extensive subaerial calcitic moonmilk wall deposit of a more conventional nature but of an extraordinary thickness and abundance. Both the cottonballs …

Observations On The Cave-Associated Beetles (Coleoptera) Of Nova Scotia, Canada, Max Moseley

International Journal of Speleology

The cave-associated invertebrates of Nova Scotia constitute a fauna at a very early stage of post-glacial recolonization. The Coleoptera are characterized by low species diversity. A staphylinid Quedius spelaeus spelaeus, a predator, is the only regularly encountered beetle. Ten other terrestrial species registered from cave environments in the province are collected infrequently. They include three other rove-beetles: Brathinus nitidus, Gennadota canadensis and Atheta annexa. The latter two together with Catops gratiosus (Leiodidae) constitute a small group of cave-associated beetles found in decompositional situations. Quedius s. spelaeus and a small suite of other guanophiles live in accumulations of …

Electrodeposition Of Inorganic Materials With Tailored Shapes And Chiral Morphologies, Elizabeth A. Kulp

Doctoral Dissertations

"This dissertation investigates the electrodeposition of metal oxide films and biomaterial deposits on polycrystalline and single crystal substrates. Paper I describes the mechanisms and the characterization of an electrodeposited polycrystalline insulator, ceria (CeO₂), on Hastelloy substrates produced by the electrochemical oxidation of Ce(III) acetate complexes. In Paper II, epitaxial films of magnetite (Fe₃O₄) and ferrihydrite (Fe₁₀O₁₄(OH)₂) are deposited on gold single crystals. Paper III reports the electrodeposition of epitaxial Fe₃O₄ and zinc ferrite (ZnFe₂O₄) periodic nanostructures known as superlattices by pulsing between two potentials. Papers IV and V describe chiral electrodeposition. In Paper IV, epitaxial, chiral orientations of cupric oxide …

Rational Construction By Molecular Dynamics Modeling And Simulations Of Porous Adsorbent Media For Bioseparation, Enrico Riccardi

Doctoral Dissertations

"Ion-exchange chromatography employing porous adsorbent particles or monoliths in which charged ligands are immobilized onto polymeric extender molecules grafted on the pore surfaces of a base matrix has become a very important method for bioseparations. In this dissertation, a novel fundamental and systematic methodology has been developed that uses the molecular dynamics (MD) modeling and simulation approach to rationally design, construct, and characterize polymeric porous adsorbent media and study the transport and adsorption of a charged biomolecule (desmopressin) in a representative adsorbent medium. The MD results have also been utilized in a macroscopic model to study the large-scale dynamic behavior …

A Study Of The Beneficial Role Of Thiol Antioxidant Supplementation In Various Forms Of Glutathione Deficiency, Linu Sara Abraham

Doctoral Dissertations

"Oxidative stress plays a major role in the pathology of numerous disorders afflicting humans, ranging from neurodegenerative diseases, to cancer, and heavy metal toxicity. Scientists are on the constant lookout for new and better antioxidants that have the ability to slow, if not stop the harmful degenerative effects of free radicals in oxidative stress related disorders. Both synthetic and naturally occurring compounds are being constantly screened for their antioxidant properties. This study attempted to evaluate the abilities of a thiol antioxidant, N-Acetylcysteine amide (NACA), to protect cells from the harmful effects of glutathione depletion in two different models of oxidative …

Applications Of Sensor Arrays In Acoustic And Seismic Signal Processing, Peng Xie

Doctoral Dissertations

"This work investigates the applications of sensor arrays in the areas of acoustic and seismic signal processing. It comprises three papers.

The first paper explores the problem of blind source separation (BSS) for convolutive acoustic signals. It concentrates on the well known permutation and amplitude problems in frequency-domain BSS and proposes a new hybrid approach to solve them. This approach connects the separation processes across all frequency bins, and relies on a novel permutation control unit. This framework could greatly reduce computational load and improve separation performance. Synthesized and real-world experiments demonstrate its efficiency.

The second paper investigates a new …

On Unified Computational Intelligence: Neural Networks, Dynamic Programming, And Applications To Economics And Finance, John E. Seiffertt Iv

Doctoral Dissertations

"This dissertation introduces the concept of unified computational intelligence and encompasses algorithm design, applications, theoretical developments, and the identification of new frontiers for multidisciplinary research. It presents a new way to look at unified learning systems and presents a novel Adaptive Resonance Theory-based unified learning architecture. An application to robotic security and sensor fusion is given in detail.

Work on the theoretical developments of unified computational intelligence is also presented. A new theorem in the time scales calculus is proven and theorems on the Hamilton-Jacobi-Ballman equation of dynamic programming and the dynamic programming algorithm are presented, both for various general …

Systematic Functional And Object-Oriented Product Design Frameworks, Jen-Chi Wu

Doctoral Dissertations

"The existing co-design methods of mechatronic products focus on co-design of mechanical and electronic components or co-design of computer hardware and software components. There exist no effective co-design methods for mechanical, electronic and software components at the concept design stage. The research objective of this dissertation work is to develop more effective systematic product design approaches for co-design of mechatronic products. Three innovative functional and object-oriented integrated design frameworks and one virtual prototyping application, which leverages on these three design frameworks, have been developed for co-design of mechatronic products. The three frameworks are: I) Hierarchical Object-Oriented Functional Modeling Framework, 2) …

The Role Of Stochastic Resonance And Physical Constraints In The Evolution Of Foraging Strategy, Nathan Daniel Dees

Doctoral Dissertations

"This work represents a detailed study of the optimization of this process: foraging within a single, finite food patch for a limited amount of time. The work is an example of the computational algorithms of statistical physics being applied to the ecological field of foraging behavior. The analysis begins with an examination of the probability distributions observed in the movement parameters of the zooplankton, Daphnia. While foraging, these small aquatic organisms stochastically choose movement parameters with particular levels of variation, or noise, which are similar across several species. Here, related simulations consistently show that these noise levels may be adjusted …

Interference Effects Due To Projective-Target Nucleus Scattering In Single Ionization Of Molecular Hydrogen By 75 Kev Proton Impact, Jason S. Alexander

Doctoral Dissertations

"Doubly-differential cross-sections for the single ionization of molecular hydrogen by 75 keV proton impact have been measured as a function of the projectile scattering angle and energy loss and compared to available theoretical models. Interference structures are directly observed in the scattering angular dependence of the DDCS. The phase angle appears to be most sensitive to the projectile angle but not as sensitive to the electron energy, suggesting that the projectile - target nucleus interaction plays a central role in the interference. The large-angle structures disappear at electron speeds near the projectile speed. This may be due to a focusing …

A Phenomenographic Study Of Introductory Physics Students: Approaches To Problem Solving And Conceptualisation Of Knowledge., Laura Walsh

Doctoral

This phenomenographic study presents a description of the approaches to problem solving and conceptualisation of physics knowledge of introductory physics students, specifically in the context of the Irish higher education system. Much research has been carried out that has shown that physics students are not developing the conceptual knowledge necessary to become adept problem-solvers. This may be due to the traditional physics education assumption that students will develop an understanding of the conceptual nature of physics by repetitively solving quantitative problems. However, research has shown that this is not the case and that education and the curriculum needs to explicitly …

Holographic Liquid Crystal Devices, Kotakonda Pavani

Doctoral

Liquid crystals have become natural candidates for use in electro-optic devices for their ability to change the orientation of the director with the application of an electric field, and exhibiting large range of refractive index. The aim of the work presented in this thesis is to fabricate liquid crystal optoelectronic devices such as electrically switchable liquid crystal diffraction gratings and polarization rotators by exploiting the holographic surface relief effect in photopolymer and by developing novel polymer dispersed liquid crystals (PDLCs). Alignment of liquid crystals is commercially achieved by creating grooves on a conducting layer such as polyimide or indium tin …

Three-Dimensional Spatial Information Systems: State Of The Art Review, Bianca Schoen-Phelan, D. Laefer, S. W. Morrish, M. Bertolotto

Articles

A spatial information system (SIS) is critical to the hosting, querying, and analyzing of spatial data sets. The increasing availability of three-dimensional (3D) data (e.g. from aerial and terrestrial laser scanning) and the desire to use such data in large geo-spatial platforms have been dual drivers in the evolution of integrated SISs. Within this context, recent patents demonstrate efforts to handle large data sets, especially complex point clouds. While the development of feature-rich geo-systems has been well documented, the implementation of support for 3D capabilities is only now being addressed. This paper documents the underlying technologies implemented for the support …

Arrow's Theorem And The Exclusive Shareholder Franchise, Grant M. Hayden, Matthew T. Bodie

All Faculty Scholarship

In this essay, we contest one of the main arguments for restricting corporate board voting to shareholders. In justifying the limitation of the franchise to shareholders, scholars have repeatedly turned to social choice theory—specifically, Arrow’s theorem—to justify the exclusive shareholder franchise. Citing to the theorem, corporate law commentators have argued that lumping different groups of stakeholders together into the electorate would result in a lack of consensus and, ultimately, the lack of coherence that attends intransitive social choices, perhaps even leading the corporation to self-destruct. We contend that this argument is misguided. First, we argue that scholars have greatly overestimated …

Shareholders In The Jury Box: A Populist Check Against Corporate Mismanagement, Ann M. Scarlett

All Faculty Scholarship

The recent subprime mortgage disaster exposed corporate officers and directors who mismanaged their corporations, failed to exercise proper oversight, and acted in their self-interest. Two previous waves of corporate scandals in this decade revealed similar misconduct. After the initial scandals, Congress and the Securities and Exchange Commission attempted to prevent the next crisis in corporate governance through legislative and regulatory actions such as the Sarbanes-Oxley Act of 2002. Those attempts failed. Shareholder derivative litigation has also failed because judges accord corporate executives great deference and thus rarely impose liability for breaches of fiduciary duties.

To prevent the next crisis in …

Clawbacks: Prospective Contract Measures In An Era Of Excessive Executive Compensation And Ponzi Schemes, Miriam A. Cherry, Jarrod Wong

All Faculty Scholarship

In the spring of 2009, public outcry erupted over the multi-million dollar bonuses paid to AIG executives even as the company was receiving TARP funds. Various measures were proposed in response, including a 90% retroactive tax on the bonuses, which the media described as a "clawback." Separately, the term "clawback" was also used to refer to remedies potentially available to investors defrauded in the multi-billion dollar Ponzi scheme run by Bernard Madoff. While the media and legal commentators have used the term "clawback" reflexively, the concept has yet to be fully analyzed. In this article, we propose a doctrine of …