Physical Sciences and Mathematics Commons^™

Factors Leading To Success Or Abandonment Of Open Source Commons: An Empirical Analysis Of Sourceforge.Net Projects, Charles M. Schweik, Robert English, Sandra Haire

Charles M. Schweik

Open source software is produced cooperatively by groups of people who work together via the Internet. The software produced usually becomes the “common property” of the group and is freely distributed to anyone in the world who wants to use it. Although it may seem unlikely, open source collaborations, or “commons,” have grown phenomenally to become economically and socially important. But what makes open source commons succeed at producing something useful, or alternatively, what makes them become abandoned before achieving success? This paper reviews the theoretical foundations for understanding open source commons and briefly describes our statistical analysis of over …

Optical Tomography For Media With Variable Index Of Refraction, Stephen R. Mcdowall

Mathematics Faculty Publications

Optical tomography is the use of near-infrared light to determine the optical absorption and scattering properties of a medium M ⊂ Rⁿ. If the refractive index is constant throughout the medium, the steady-state case is modeled by the stationary linear transport equation in terms of the Euclidean metric and photons which do not get absorbed or scatter travel along straight lines. In this expository article we consider the case of variable refractive index where the dynamics are modeled by writing the transport equation in terms of a Riemannian metric; in the absence of interaction, photons follow the geodesics …

Modulation Invariant Bilinear T(1) Theorem, Árpád Bényi, Ciprian Demeter, Andrea R. Nahmod, Christoph M. Thiele, Rodolfo H. (Rudolfo Humberto) Torres, Paco Villarroya

Mathematics Faculty Publications

We prove a T(1) theorem for bilinear singular integral operators (trilinear forms) with a one-dimensional modulation symmetry.

Local Well-Posedness Of Nonlinear Dispersive Equations On Modulation Spaces, Árpád Bényi, Kasso A. Okoudjou

Mathematics Faculty Publications

By using tools of time-frequency analysis, we obtain some improved local well-posedness results for the nonlinear Schrödinger, nonlinear wave and nonlinear Klein–Gordon equations with Cauchy data in modulation spaces ℳ_0,s^p,1.

A Critical Constant For The K Nearest-Neighbour Model, Paul Balister, Béla Bollobás, Amites Sarkar, Mark Walters

Mathematics Faculty Publications

Let P be a Poisson process of intensity 1 in a square S_n of area n. For a fixed integer k, join every point of P to its k nearest neighbours, creating an undirected random geometric graph G_n,k. We prove that there exists a critical constant c_crit such that, for c‹c_crit, G_{n,⌊clogn⌋} is disconnected with probability tending to 1 as n →∞ and, for c‹c_crit, G_{n,⌊clogn⌋} is connected with probability tending to 1 as n →∞. This answers a question …

Numerical Bifurcation Of Separable Parameterized Equations, Yun-Qiu Shen, Tjalling Ypma

Mathematics Faculty Publications

Many applications give rise to separable parameterized equations, which have the form A(y, µ)z + b(y, µ) = 0, where z ∈ R^N , y ∈ Rⁿ, µ ∈ R^s, and the (N + n) × N matrix A(y, µ) and (N + n) vector b(y, µ) are C² -Lipschitzian in (y, µ) ∈ Ω ⊂ Rⁿ × R^s. We present a technique which reduces the original equation to the form …

Violence On The Brain: A Critique Of Neuroscience In Criminal Law, Amanda C. Pustilnik

Faculty Scholarship

Is there such a thing as a criminally "violent brain"? Does it make sense to speak of "the neurobiology of violence" or the "psychopathology of crime"? Is it possible to answer on a physiological level what makes one person engage in criminal violence and another not, under similar circumstances?

This Article first demonstrates parallels between certain current claims about the neurobiology of criminal violence and past movements that were concerned with the law and neuroscience of violence: phrenology, Lombrosian biological criminology, and lobotomy. It then engages in a substantive review and critique of several current claims about the neurological bases …

Experimental Evidence Of Non-Linear Dissipation Using Acoustic Micro-Lapses, G. Quiroga-Goode, K. Van Wijk

Geosciences Faculty Publications and Presentations

Non-linear material behaviour is observed experimentally in a laboratory using a new method called Acoustic Micro-Lapses (AML). In this approach, the shooting of two waves is synchronised in a way that the second wave (TW) is to sense the fluctuations in material stiffness induced by the first (PW). The tests include four samples; twenty trials are performed for each sample by increasing time-delays between the waves. The recorded waves are decoupled and compared to determine spectral differences by computing a quantity proportional to the energy difference as function of the increasing time delay (). For a tight sandstone and aluminium …

The Macro-Structure Of Use Of Help, Oscar D. Andrade, David G. Novick, Nathaniel Bean

Departmental Papers (CS)

Users of help systems often complain that they do not find them useful; while they still use help at least occasionally, they resort to other problem-solving strategies. In this paper, we analyze audiovisual recordings of people using a computer application, to identify (1) transition patterns among problem-solving approaches, and (2)the frequency of these transitions. Our analysis indicates that people switch frequently between consulting help and exploring the interface. Switching between problem-solving approaches appears to be an effective way of succeeding in tasks. Applications and their help systems can be better designed to support users who switch between help and non-help …

Synthesis And Characterization Of Acetylenic Derivatives Of The Actinide Extractant (Aryl) N,N Di (Alkyl)Carbamoylmethylphosphine Oxide (Cmpo), Mario Ivan Baeza

Open Access Theses & Dissertations

We have used the reaction between the sodium salt of (diaryl)-N,N-di-(isobutyl)carbamoylmethylphosphine oxides {[Aryl)2P=O][iBu2NC=O]CH}-Na+ and chloromethylacetylenes to produce the first acetylenic derivatives of the carbamoylmethylphosphine oxide (CMPO) actinide extractants. The new compounds - CMPO-CH2C2H (1) {aryl = phenyl}, (2) {aryl = tBu-phenyl}; CMPO-CH2C2Me (3) {aryl = phenyl}; and CMPO-CH2C2CH2Cl (4) {aryl = phenyl}, (5) {aryl = tBu-phenyl} - have been characterized by spectroscopy (1H, 13C, 32P NMR) and also by single crystal X-ray diffraction. These new extractants lead the way to new derivatives aimed at using the materials as both optical and electrochemical actinide and other metal sensors.

Magnitude Of Right-Lateral Offset On The Southern Death Valley Fault Zone From Miocene Volcanic Assemblages, Sabrina Michelle Canalda

Open Access Theses & Dissertations

In this study correlation of Miocene volcanic and sedimentary rocks in southern Death Valley is used to constrain the total amount of slip on the southern Death Valley fault. The tertiary volcanic section near Ibex Pass is correlated to rocks ~35 km to the northwest, in the Wingate Wash region (Luckow et al., 2005). Geochronology by Luckow et al. (2005) in Wingate Wash and the Owlshead Mountains has the region divided into two basic periods: an early interval (~14-13.4Ma), and a later phase (~13-12.5Ma). One date from the volcanic sequence in Ibex Pass has been reported (Calzia, 2000) suggesting that …

High-Temperature Phase Transitions In Rbh2po4, Heber Jair Martinez

Open Access Theses & Dissertations

Recent studies have shown that the proton conductivity of MH2PO4 (M=Cs, Rb) solid-acids exhibits a sharp, several-order-of-magnitude increase upon heating above a certain temperature threshold [Boysen et al., Chem. Mater. 15, 727(2003), Boysen et al., Chem. Mater. 16, 693(2004)]. This so-called superprotonic behavior allows the above-mentioned compounds to function as fuel-cell electrolytes at intermediate temperatures [Boysen et al., Science 303, 68(2004)], a remarkable application that has attracted much interest. Yet, the crystal structures and microscopic mechanisms responsible for this heating-induced proton conductivity enhancement are not fully understood.

Our group has previously demonstrated [Botez et al., J. Chem. Phys. 127, 194701(2007)] …

The Isotopological Homodesmotic Reaction: A Further Refinement To The Quantification Of Aromaticity, Marco Olguin

Open Access Theses & Dissertations

Aromaticity imparts a significant energetic stabilization to various chemical systems as a result of cyclic pi-electron delocalization. One of the most widely used methods for the quantification of the Aromatic Stabilization Energy (ASE) of a molecule is the formulation of a Homodesmotic reaction. The following research employs a refined Homodesmotic approach based on previous work by Herndon and Mills which utilized Isotopological Homodesmotic Reactions (IHR) to determine the Aromatic Stabilization Energy (ASE) of a flourenyl cation. The advantage of employing an IHR for an ASE calculation is that the strain energy contribution from the sigma framework of reactant and product …

Geography Of Pestecide Exposure In The Lower Valley (El Paso County, Texas), Critina Solis Sanchez

Open Access Theses & Dissertations

Previous studies using GIS have been used to understand the demographics of particular areas of a city and the risks associated with living there. In the Lower Valley (Socorro, Clint, and San Elizario) area of El Paso County (TX), there has been a rapid growth in population. This increase in growth has led to this project about the types of pesticides used in farms and if they are creating possible health risks for people living in this area and which populations are most at risk. To determine population risk, I use existing GIS information, specifically a USDA aerial photograph taken …

Resistivity And Conductivity Studies Of The Rattlesnake Springs, New Mexico Watershed, Claudia Santiago

Open Access Theses & Dissertations

Rattlesnake Springs are a high-discharge artesian springs situated in the upper Black River Valley in southwestern Eddy Country, New Mexico. The aquifer that supplies the Rat- tlesnake Springs has been the main water source for domestic use by visitors of Carlsbad Caverns National Park and residents of neighboring ranches since the 1930s. Several ge- ological studies relying on surface geology and limited water wells had previously been conducted in the area to examine the trend of ground water flow. In this study I used con- ductivity and resistivity geophysical techniques to identify possible locations of fractures in the subsurface of …

Information Overload: Cctv, Your Networks, Communities And Crime, Vandra Harris, Crispin Harris

Australian Security and Intelligence Conference

Electronic surveillance continues to play a central but often unobserved role in contemporary Western societies and attempts to police them. This paper focuses on closed circuit television (CCTV) footage and its technological implications, particularly relating infrastructure and data storage and integrity. While CCTV might appear attractive in augmenting law enforcement systems, the authors argue that the debate on use of CCTV in crime prevention remains incomplete without an effective understanding of the diverse costs. This discussion reveals startling ICT resource needs and associated costs, together with very specific technological capacity. These contribute significantly to the costs of such systems, reinforcing …

Professional Intelligence Judgement Artistry: Some Early Observations, Jeff Corkill

Australian Security and Intelligence Conference

Intelligence analysis is critical national security and law enforcement function dependant on the intellectual capacity of individual analysts. The practice of intelligence is undertaken in an extremely complex environment often under a veil of secrecy, and where uncertain and deceptive information represents the norm. In order to develop as a profession appropriate constructs with which to explore and explain how analysts process intelligence, make decisions and reach judgements are needed. An improved understanding will offer opportunities to develop appropriate training and professional development for intelligence analysts. This paper introduces the construct of Professional Intelligence Judgement Artistry together with some very …

Security Decay: An Entropic Approach To Definition And Understanding, Michael Coole, David J. Brooks

Australian Security and Intelligence Conference

This article discusses the affect decay has within a systems approach used when implementing security strategies, in particular, the theory of defence in depth. Defence in depth is implemented within a risk management framework to reduce an organisation’s identified risks, which could lead to undesirable and unacceptable consequences. Defence in depth aims to link layered security elements into a system to ensure a holistic and functional security system, underpinned by the functions of; deter, detect, delay, response and recovery. For such a system to be commissioned and maintain its commissioning effectiveness, these functions must be performed in their sequential order …

Toward A New Sustainable Economy, Robert Costanza

Institute for Sustainable Solutions Publications and Presentations

The current financial meltdown is the result of under-regulated markets built on an ideology of free market capitalism and unlimited economic growth. The fundamental problem is that the underlying assumptions of this ideology are not consistent with what we now know about the real state of the world. The financial world is, in essence, a set of markers for goods, services, and risks in the real world and when those markers are allowed to deviate too far from reality, ?adjustments? must ultimately follow and crisis and panic can ensue. To solve this and future financial crisis requires that we reconnect …

Design, Synthesis And Study Of The Bridged And Cofacially-Arrayed Poly-P-Phenylene Molecular Wires, Matthew J. Modjewski

Master's Theses (2009 -)

Two novel series of bridged and cofacially-arrayed poly-p-phenylenes have been designed synthesized and studied. The bridged poly-p-phenylenes have been synthesized from a readily available diacetylenic precursor utilizing three high yielding steps, and their structures were determined by 1H/13C NMR spectroscopy as well as X-ray crystallography. The racemization barrier between the two atropoisomers was found to be ~12 Kcal mol-1; the versatility of the synthesis employed was extended to synthesis a triply bridged tetra-p-phenylene and a quadruply bridged penta-p-phenylene.

The cofacially-arrayed poly-p-phenylenes have shown that the X-ray crystal structures of the neutral compounds are largely dominated by C-H--π-interactions interactions while the …

In Step With Hiv Vaccines? A Content Analysis Of Local Recruitment Campaigns For An International Hiv Vaccine Study, Paula M. Frew, Wendy Macias, Kayshin Chan, Ashley Harding

Environmental & Occupational Health Faculty Publications

During the past two decades of the HIV/AIDS pandemic, several recruitment campaigns were designed to generate community involvement in preventive HIV vaccine clinical trials. These efforts utilized a blend of advertising and marketing strategies mixed with public relations and community education approaches to attract potential study participants to clinical trials (integrated marketing communications). Although more than 30,000 persons worldwide have participated in preventive HIV vaccine studies, no systematic analysis of recruitment campaigns exists. This content analysis study was conducted to examine several United States and Canadian recruitment campaigns for one of the largest-scale HIV vaccine trials to date (the “Step …

Synthesis And Evaluation Of Some Steroidal Oximes As Cytotoxic Agents: Structure/Activity Studies (I), Jianguo Cui, Lei Fan, Li Liang Huang, Hong Li Liu, Aimin Zhou

Chemistry Faculty Publications

The side chain of a compound plays an important role in its biological function. In our studies, we have found that hydroximinosteroid derivatives with different side chains and position of hydroximino on ring A and B displayed remarkable distinct cytotoxicities against a diversity of cancer cell types. Presence of an oxime group on ring B and a hydroxy on ring A or B resulted in a higher cytotoxicity than other structural motifs. In addition, a cholesterol-type side chain at position 17 was required for the biological activity. Our findings provide new evidence showing the relationship between the chemical structure and …

Nos-Based Biopolymers: Towards Novel Thromboresistant No-Release Materials, Charbel Abou Diwan

ETD Archive

Nitric Oxide releasing biopolymers have the potential to prolong vascular graft and stent potency without adverse systemic vasodilation. It was reported in literature that eNOS-overexpressing endothelial cell seeding of synthetic small diameter vascular grafts decreased human platelet aggregation by 46 and bovine aortic smooth muscle cell proliferation by 67.2 in vitro. We hypothesized that incorporating the enzyme nitric oxide synthase (NOS) in biocompatible polymeric matrix will provide a source of NO that utilizes endogenous compounds to maintain an unlimited supply of NO. To test this hypothesis, we have incorporated the enzyme nitric oxide synthase into a polyethyleneimine film using a …

Cofactor Control Of A Vital Enzymatic Reaction;The Effect Of Factor Va On Thrombin Formation During Blood Coagulation, Jamila Hirbawi

ETD Archive

The LONG-TERM goal of our research is to study and analyze the structure and function of the factor V molecule in order to understand its regulatory effects on the natural process of hemostasis and its role in the life-threatening development of deep venous thrombosis. The SHORT-TERM goal of our research is to identify the amino acid residue(s) of factor V that interact with prothrombin during the assembly and function of the prothrombinase complex in order to fully understand its particular role in maintaining the integrity of the blood coagulation cascade. The final goal of the coagulation cascade is the formation …

Hemoprotein-Mediated Activation Of Nitroalkanes, Ling Li

ETD Archive

Chemicals and drugs are known to be metabolized mostly by Cytochrome P450 xenobiotic metabolizing enzymes. However, the detailed mechanism of nitro-compounds metabolism is still unclear. The activation of nitro-xenobiotics by heme-P450 enzymes is a potential explanation for the origin of nitro-compound carcinogenesis. Investigating the interaction of simple nitro-compounds with redox activity of heme enzymes is therefore critical to explore the mechanism and products of activation. In this study, multiple analytical methods and instrumentations are employed and graphic and simulation software such as Origin┬« and Digisim┬« are utilized to quantitatively derive parameters from experimental raw data. This study shows that myoglobin, …

Structural Investigation Of The Complex Of Filamin A Repeat 21 With Integrin Αiib And Β3 Cytoplasmic Tails – A Potential “Transmission” To Regulate Cell Migration, Jianmin Liu

ETD Archive

Cell functions in multi-cellular organisms are strongly depend on the dynamic cooperation between cell adhesion and cytoskeleton reorganization. Integrins, the major cell adhesion receptors, bind to extracellular matrix (ECM) and soluble ligands on the cell surface and link to the actin cytoskeleton inside the cell membrane. In this manner, integrins integrate cell adhesion and cytoskeleton reorganization by acting as a mechanical force transducer and a biochemical signaling hub (Zamir and Geiger 2001). Consequently, integrins are vital for development, immune responses, leukocyte traffic and hemostasis, and a variety of other cellular and physiological processes. Integrins are also are the focal point …

Hemeproteins Bathed In Ionic Liquids;Examining The Role Of Water And Protons In Redox Behavior And Catalytic Function, John Joseph Moran

ETD Archive

We investigate the changing behaviors of myoglobin and nitric oxide synthase (NOS) in the near-absence of bulk water and/or protons by using ionic liquid butyl methyl imidazolium tetrafluoroborate as a non-aqueous milieu. Through direct charge transfer and metalloprotein-mediated catalytic reduction of oxygen and nitric oxide, we shed light on diverging aspects on how the two hemeproteins face the scarcity of water and/or protons in bulk. Isotopic effect investigations using D2O further elucidates kinetic aspects of proton transfer. Finally, in the case of NOS oxygenase, pterin cofactor binding and NOS-mediated catalytic oxidation of L-arginine in ionic liquids interrogates proton and water …

Development Of Quantitative Bioanalytical Methods For The Measurement Of Pharmaceutical Compounds Via Hplc-Uv And Hplc-Ms/Ms, Melissa A. Mcculloch

ETD Archive

Research in pharmaceutical treatments for illnesses and disease processes has rapidly grown in the past decade. The field is fueled by advances in our understanding of the molecular mechanics of the human body, coupled with the development of sophisticated scientific instruments which can efficiently generate massive amounts of important data. This has led to an ever-growing need for the development of quantitative bioanalytical methods to measure pharmaceutical compounds. In this work, the theory behind the analytical processes and instruments that make these investigations possible is discussed. Further, the development of two high performance liquid chromatographic (HPLC) methods with both ultra …

Fabricating New Miniaturized Biosensors For The Detection Of Dna Damage And Dna Mismatches, N. Indika Perera

ETD Archive

A large number of genetic diseases and genetic disorders are simply caused by base alterations in the genome. Therefore, developing efficient and cost effective techniques for routine detection of these alterations is of great importance. Different methods involving gel electrophoresis and Polymerase Chain Reaction have been widely employed, but majority of these methods are costly, time consuming, and lack throughput, creating a fundamental gap between the current state-of-the-art and desired characteristics of low-cost, high-speed, simplicity, versatility, and potential for miniaturization. In this study, we attempt to bridge this gap by developing new sensing platforms to detect DNA base mismatches and …

New Generation Of Electrochemical Sensors For Nitric Oxide;Ruthenium/Carbon-Based Nanostructures And Colloids As Electrocatalytic Platforms, W. Pubudu M. Peiris

ETD Archive

Nitric oxide (NO) is an important intercellular messenger that acts in many tissues to regulate a diverse range of physiological and pathological processes. The physiologically implications of NO function are far from being completely understood. The multifaceted reactivity of NO prompted the need for accurate determination of the concentration of this molecule. However, it is difficult to detect nitric oxide, particularly in biological media and near live cells due to its short half-life, a result of its reactivity and the low levels of NO produced in vivo. As a result, the accurate and reliable detection of NO under varying experimental …