Physical Sciences and Mathematics Commons^™

Laser-Induced Photon-Branched Chain Reaction In A Chemically-Active Gas-Dispersed Medium, Thomas F. George, Renat R. Letfullin, Galen C. Duree

Thomas George

Giant Sequoia Insect, Disease, And Ecosystem Interactions, Douglas D. Piirto

Douglas D. Piirto

Individual trees of giant sequoia (Sequoia gigantea [Lindl.] Decne.) have demonstrated a capacity to attain both a long life and very large size. It is not uncommon to find old-growth giant sequoia trees in their native range that are 1,500 years old and over 15 feet in diameter at breast height. The ability of individual giant sequoia trees to survive over such long periods of time has often been attributed to the species high resistance to disease, insect, and fire damage. Such a statement, however, is a gross oversimplification, given broader ecosystem and temporal interactions. For example, why isn't there …

Efficacy Of Herbicide Application Methods Used To Control Tanoak (Lithocarpus Densiflorus) In An Uneven-Aged Coast Redwood Management Context, Douglas D. Piirto, Brenda Smith, Eric K. Huff, Scott T. Robinson

Douglas D. Piirto

Three methods of tanoak (Lithocarpus densiflorus [Hook. & Arn.] Rehd.) control involving the application of the amine or ester form of triclopyr were evaluated in this coast redwood uneven-aged forest management study of herbicides. A cut-stump application with the amine form of triclopyr (Garlon 3A), frill cut with the amine form of triclopyr, basal-bark (outer surface) with the ester form of triclopyr (Garlon 4), and an untreated control were replicated three times. The tanoak control results in Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) and/ or coast redwood (Sequoia sempervirens [D. Don] Endl.) predominated stands obtained in earlier studies …

Cost-Effective Fire Management For Southern California's Chaparral Wilderness: An Analytical Procedure, Chris A. Childers, Douglas D. Piirto

Douglas D. Piirto

Fire management has always meant fire suppression to the managers of the chaparral covered southern California National Forests. Today, Forest Service fire management programs must be cost effective, while wilderness fire management objectives are aimed at recreating natural fire regimes. A cost-effectiveness analysis has been developed to compare fire management options for meeting these objectives in California's chaparral wilderness. This paper describes the analytical procedure using examples from a study currently being conducted for the Los Padres National Forest, and discusses some preliminary results.

Leading Firms As Knowledge Gatekeepers In A Networked Environment, Deogratias Harorimana Mr

Dr Deogratias Harorimana

This chapter introduces the role of the knowledge gatekeeper as a mechanism by which knowledge is created and transferred in a networked environment. Knowledge creation and transfer are essential for building a knowledge based economy. The chapter considers obstacles that inhibit this process and argues that leading firms create a shared socio-cultural context that enables the condivision of tacit meanings and codification of knowledge. Leading firms act as gatekeepers of knowledge through the creation of shared virtual platforms. There will be a leading firm that connects several networks of clients and suppliers may not interact directly with one another, but …

Word Sense Disambiguation In Biomedical Ontologies With Term Co-Occurrence Analysis And Document Clustering, Bill Andreopoulos, Dimitra Alexopoulou, Michael Schroeder

William B. Andreopoulos

Protection Of Retinal Cells From Ischemia By A Novel Gap Junction Inhibitor, Satyabrata Das, Dingo Lin, Snehalata Jena, Aibin Shi, Srinivas Battina, Duy H. Hua, Rachel A. Allbaugh, Dolores J. Takemoto

Rachel A. Allbaugh

Retinal cells which become ischemic will pass apoptotic signal to adjacent cells, resulting in the spread of damage. This occurs through open gap junctions. A class of novel drugs, based on primaquine (PQ), was tested for binding to connexin 43 using simulated docking studies. A novel drug has been synthesized and tested for inhibition of gap junction activity using R28 neuro-retinal cells in culture. Four drugs were initially compared to mefloquine, a known gap junction inhibitor. The drug with optimal inhibitory activity, PQ1, was tested for inhibition and was found to inhibit dye transfer by 70% at 10 μM. Retinal …

Improved Uses And Values For The Byproducts Of The Developing Biofuels Industry, Kurt A. Rosentrater

Kurt A. Rosentrater

No abstract provided.

Simultaneous Confidence Bands For The Coefficient Function In Functional Regression, Philip T. Reiss

Philip T. Reiss

No abstract provided.

Inferring Group Differences In Brain Connectivity From Functional Magnetic Resonance Images, Philip T. Reiss

Philip T. Reiss

No abstract provided.

Unraveling Protein Networks With Power Graph Analysis, Loïc Royer, Matthias Reimann, Bill Andreopoulos, Michael Schroeder

William B. Andreopoulos

Reliability Of Functional Connectivity Networks: How Can We Assess It?, Philip T. Reiss

Philip T. Reiss

No abstract provided.

Polypyrrole Based Switchable Filter System, Yanzhe Wu, Lorrain Nolan, Shirley Coyle, King Tong Lau, Gordon G. Wallace, Dermot Diamond

Gordon Wallace

BioTex is an EU funded project aiming to develop textile-based sensors for monitoring biological fluids. In the context of the project, there is a need to develop an effective sample delivery strategy for the wearable biomedical devices. A compact, electroactive switchable membrane would be useful as a valve to control the sample delivery within such devices. A method that employed inherently conducting polymers deposited onto a permeable substrate to form a switchable membrane was investigated [1, 2, 3]. By application of specific voltages, the permeability (pore size) of the membrane can be switched to swollen (expand) and contracted forms, which …

Conducting Polymer-Carbon Nanotubes Composites, May Tahhan, N. Barisci, Gordon G. Wallace

Gordon Wallace

During the course of this work, three different approaches to the formation of conducting polymer/carbon nanotube (CP/CNT) composites were investigated. The first approach involved the preparation of CNT dispersions using Poly methoxy aniline-5-sulfonic acid (PMAS) as a stabilizer. The second approach investigated involved the use of CNT as the dopant in the electropolymerization of CPs. The third approach involved the electrochemical deposition of a thin polymer film onto the surface of CNT paper. These CNT/CP composites were characterized to determine capacitance, conductivity and mechanical strength.

Writing Research Proposal: Literature Review And Database Search, Mamoudou H. Dicko Prof.

Pr. Mamoudou H. DICKO, PhD

Repellent Properties Of Δ-Octalactone Against The Tsetse Fly, Glossina Morsitans Morsitans, Martin T. Mwangi, Nicholas K. Gikonyo, Isaiah O. Ndiege

Martin M. Thuo

δ-octalactone, produced by several Bovidae, has been suggested as a potential repellant of tsetse fly attack. Racemic δ-octalactone was synthesized via an abbreviated route. The product was assayed against 3-day old starved teneral female tsetse flies, Glossina morsitans morsitans Wiedemann (Diptera: Glossinidae), in a choice wind tunnel and found to be a potent tsetse repellent at doses ≥0.05 mg in 200 μl of paraffin oil (0.05 >p >0.01).

Dioxidobis(2-Oxo-1,2-Dihydropyridin-3-Olato)­Molybdenum(Vi), Manoj Trivedi, Daya Shankar Pandey, Nigam P. Rath

Nigam Rath

Diethyl 2-[(4-Nitro­Phen­Yl)(4-Phenyl-1,2,3-Selenadiazol-5-Yl)Meth­Yl]Malonate, A. Marx, S. Saravanan, S. Muthusubramanian, V. Manivannan, Nigam P. Rath

Nigam Rath

Modeling The Effects Of Value-Added Processing And Logistics Using Arena, Kurt A. Rosentrater, Elif Kongar

Kurt A. Rosentrater

Scarcity and cost of nonrenewable fossil fuels have been a growing focus of many energy-dependent nations, including the U.S., for the past couple of decades. There are mainly two ways to approach these problems: (1) reducing the energy dependency and/or (2) developing alternative means of energy production. Utilizing biofuels, which are renewable sources of energy, is a promising way to produce energy. But, as this industry grows, so too does the quantity of byproducts, which are known as DDGS. This paper discusses a model that has been developed to analyze the economic viability of DDGS processing, and includes both deterministic …

Second-Sphere Amino Acids Contribute To Transition-State Structure In Bovine Purine Nucleoside Phosphorylase, Lei Li, Minkui Luo, Mahmoud Ghanem, Erika A. Taylor, Vern L. Schramm

Erika A. Taylor, Ph.D.

Transition-state structures of human and bovine of purine nucleoside phosphorylases differ, despite 87% homologous amino acid sequences. Human PNP (HsPNP) has a fully dissociated transition state, while that for bovine PNP (BtPNP) has early SN1 character. Crystal structures and sequence alignment indicate that the active sites of these enzymes are the same within crystallographic analysis, but residues in the second-sphere from the active sites differ significantly. Residues in BtPNP have been mutated toward HsPNP, resulting in double (Asn123Lys; Arg210Gln) and triple mutant PNPs (Val39Thr; Asn123Lys; Arg210Gln). Steady-state kinetic studies indicated unchanged catalytic activity, while pre-steady-state studies indicate that the chemical …

4-(4-Chlorophenyl)-5-[1-(4-Chlorophenyl)-2-Methyl-2-Nitropropyl]-1,2,3-Selenadiazole, A. Marx, S. Saravanan, S. Muthusubramanian, V. Manivannan, Nigam P. Rath

Nigam Rath

Microproteomics: Analysis Of Protein Diversity In Small Samples, Howard B. Gutstein, Jeffrey S. Morris, Suresh P. Annangudi, Jonathan V. Sweedler

Jeffrey S. Morris

Proteomics, the large-scale study of protein expression in organisms, offers the potential to evaluate global changes in protein expression and their post-translational modifications that take place in response to normal or pathological stimuli. One challenge has been the requirement for substantial amounts of tissue in order to perform comprehensive proteomic characterization. In heterogeneous tissues, such as brain, this has limited the application of proteomic methodologies. Efforts to adapt standard methods of tissue sampling, protein extraction, arraying, and identification are reviewed, with an emphasis on those appropriate to smaller samples ranging in size from several microliters down to single cells. The …

Optimal Switching Control For Microbial Fed-Batch Culture, Chongyang Liu, Zhaohua Gong, Enmin Feng, Hongchao Yin

Chongyang Liu

In fed-batch culture of glycerol bio-dissimilation to 1,3-propanediol (1,3-PD), the aim of adding glycerol is to obtain as much 1,3-PD as possible. Hence, a proper feed strategy is required during the process. In this paper, we present an optimal switching control model based on our proposed controlled switching system. Some properties of the controlled switching system are obtained. Subsequently, we prove the existence of optimal control. In order to deduce the optimality conditions, we transcribe the optimal switching control model into an equivalent one with fixed switching instants and parameters. Finally, the optimality conditions of the equivalent problem are investigated …

Identification Of Intracellular Kinetic Parameters In Continuous Bioconversion Of Glycerol By Klebsiella Pneumoniae, Enmin Feng, Chongyang Liu, Zhaohua Gong, Yaqin Sun

Chongyang Liu

In this paper, we propose a hybrid nonlinear dynamical system to describe the concentration changes of extracellular and intracellular substances of glycerol bioconversion to 1,3- propanedol (1,3-PD) in microbial continuous cultures. It is proved that the solution to the system exists and is continuous with respect to kinetic parameters. Subsequently, a novel quantitative definition of biological robustness is investigated. We present a performance index based on experiment data of extracellular concentrations and biological robustness. Taking the proposed hybrid nonlinear dynamical system as a constraint, we establish an identification model to determine the most reasonable metabolic pathway and optimal kinetic parameters. …

Climate Change And Freshwater Resources, Noah D. Hall, Bret B. Stuntz, Robert H. Abrams

Noah D Hall

The Earth’s climate is warming. This is the unequivocal conclusion of climate scientists. Despite the complexities of climatology, certain consistent trends emerge with implications for water availability: as the world gets warmer, it will experience increased regional variability in precipitation, with more frequent heavy precipitation events and more susceptibility to drought. These simple facts will have a profound impact on freshwater resources throughout the United States, as the warmer climate will reduce available water supplies and increase water demand. Unfortunately, current water law and policy are not up to the new challenges of climate change and resulting pressures on freshwater …

Stoichiometric Network Analysis And Associated Dimensionless Kinetic Equations. Application To A Model Of The Bray-Liebhafsky Reaction, Zeljko D. Cupic

Zeljko D Cupic

No abstract provided.

When Fairness Bends Rationality: Ernst Fehr Meets John Nash, Alessandro Tavoni

Alessandro Tavoni

No abstract provided.

Using The Estimated Penetrances To Determine The Range Of The Underlying Genetic Model In Case-Control Design, Mark J. Meyer, Neal Jeffries, Gang Zheng

Mark J Meyer

It is well known that the penetrance cannot be estimated using the retrospective case- control samples without making additional assumptions. In the literature the estimation of the penetrance is based on the assumptions that either the disease is rare or the disease prevalence is known. We propose an alternative approach to estimate the penetrance by assuming an underlying genetic model even though it is unknown. With this assumption, we can obtain the point estimates of the penetrances as functions of the genetic model, from which the range of underlying genetic models can be determined. We examine the performance of our …

Climate Change And Carbon Sequestration: Assessing A Liability Regime For Long-Term Storage Of Carbon Dioxide, Alexandra B. Klass, Elizabeth J. Wilson

Alexandra B. Klass

As the nation struggles with how to address climate change, one of the most significant questions is how to reduce increasing levels of carbon dioxide in the atmosphere. One promising technology is carbon capture and sequestration (“CCS”), which consists of capturing carbon dioxide emissions from power plants and industrial sources and sequestering them in deep geologic formations for long periods of time. Areas for potential CO2 sequestration include oil and gas fields, saline aquifers, and coal seams. As Congress and the private sector begin to spend billions of dollars to research and deploy this technology, there has been insufficient attention …

Application Of Genomics To Regulatory Ecological Risk Assessments For Pesticides, Steven P. Bradbury, Sigmund J. Degitz, Robert A. Hoke, Richard Brennan, Lee Ferguson, Rebecca Klaper, Laszlo Orban, David Spurgeon, Susan Tilton

Steven P. Bradbury

Substantial advances in human health and ecological risk assessment have been achieved by the risk assessment community; however, challenges remain, such as providing credible scientific information on a timely, efficient basis to support decisions for industrial chemicals and pesticides. Current risk assessment data generation requirements-including animal welfare concerns and the volume, appropriateness, and cost of required data-and the large number of chemicals requiring evaluation are a challenge confronting the chemical industry, national and international regulatory agencies, and associated stakeholders (Bradbury et al. 2004). The lack of hazard data for many chemicals and the need to improve the efficiency and quality …