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The Exosporium of B.cereus Contains a Binding Site for gC1qR/p33: Implication in Spore Attachment and/or Entry (open access)

The Exosporium of B.cereus Contains a Binding Site for gC1qR/p33: Implication in Spore Attachment and/or Entry

B. cereus, is a member of a genus of aerobic, gram-positive, spore-forming rod-like bacilli, which includes the deadly, B. anthracis. Preliminary experiments have shown that gC1qR binds to B.cereus spores that have been attached to microtiter plates. The present studies were therefore undertaken, to examine if cell surface gC1qR plays a role in B.cereus spore attachment and/or entry. Monolayers of human colon carcinoma (Caco-2) and lung cells were grown to confluency on 6 mm coverslips in shell vials with gentle swirling in a shaker incubator. Then, 2 {micro}l of a suspension of strain SB460 B.cereus spores (3x10{sup 8}/ml, in sterile water), were added and incubated (1-4 h; 36{sup 0} C) in the presence or absence of anti-gC1qR mAb-carbon nanoloops. Examination of these cells by EM revealed that: (1) When B. cereus endospores contacted the apical Caco-2 cell surface, or lung cells, gClqR was simultaneously detectable, indicating upregulation of the molecule. (2) In areas showing spore contact with the cell surface, gClqR expression was often adjacent to the spores in association with microvilli (Caco-2 cells) or cytoskeletal projections (lung cells). (3) Furthermore, the exosporia of the activated and germinating spores were often decorated with mAb-nanoloops. These observations were further corroborated by …
Date: January 1, 2008
Creator: Ghebrehiwet, Berhane; Tantral, Lee; Titmus, Matthew A.; Panessa-Warren, Barbara J.; Tortora, George T.; Wong, Stanislaus S. et al.
System: The UNT Digital Library
Three-Dimensional Aberration-Corrected Scanning Transmission Electron Microscopy for Biology (open access)

Three-Dimensional Aberration-Corrected Scanning Transmission Electron Microscopy for Biology

Recent instrumental developments have enabled greatly improved resolution of scanning transmission electron microscopes (STEM) through aberration correction. An additional and previously unanticipated advantage of aberration correction is the greatly improved depth sensitivity that has led to the reconstruction of a three-dimensional (3D) image from a focal series. In this chapter the potential of aberration-corrected 3D STEM to provide major improvements in the imaging capabilities for biological samples will be discussed. This chapter contains a brief overview ofthe various high-resolution 3D imaging techniques, a historical perspective of the development of STEM, first estimates of the dose-limited axial and lateral resolution on biological samples and initial experiments on stained thin sections.
Date: January 1, 2007
Creator: De Jonge, Niels; Sougrat, Rachid; Pennycook, Stephen J; Peckys, Diana B & Lupini, Andrew R
System: The UNT Digital Library
POPULATION DISTRIBUTION DURING THE DAY (open access)

POPULATION DISTRIBUTION DURING THE DAY

Population distribution during the day can be defined as distribution of population in an area during the daytime hours. However, a precise definition of daytime hours is challenging given the geographic variability in the length of a day or daylight hours. The US Census Bureau used "normal business hours" as the span of time to describe daytime population. Given that Censuses typically estimates residential population, it represents a nighttime population distribution. In that respect, daytime population in an area may be broadly defined as distribution of population at times other than when they are expected to be at their residences at night which extends the duration from business hours to include the evening hours as well.
Date: January 1, 2008
Creator: Bhaduri, Budhendra L.
System: The UNT Digital Library
National Renewable Energy Laboratory Information Resources Catalog 2002 (open access)

National Renewable Energy Laboratory Information Resources Catalog 2002

NREL's ninth annual Information Resources Catalog can keep you up-to-date on the research, development, opportunities, and available technologies in energy efficiency and renewable energy. It includes five main sections with entries grouped according to subject area.
Date: January 1, 2003
Creator: unknown
System: The UNT Digital Library
Population Evacuations (open access)

Population Evacuations

Emergency evacuation is one of the most important protective action alternatives when facing a natural or a man-made disaster. The planning and implementation of a large-scale emergency evacuation is a difficult and complex problem that requires the interactions of many agencies and involves a large amount of information. This article focuses on the latter and discusses the models that are normally used in the planning phase to evaluate this type of protective action alternatives and the information requirements for their implementation. Although many advances have been achieved in this area, especially during the last few years, a considerable amount of work still remains incomplete. Some of the important areas that need attention, such as improvements in the demographic models, integration of traffic simulation and threat evolution models, and real-time information for the deployment phase, are also discussed in this paper.
Date: January 1, 2008
Creator: Franzese, Oscar
System: The UNT Digital Library
Industrial Applications Perspective of Nanodielectrics (open access)

Industrial Applications Perspective of Nanodielectrics

The field of nanodielectrics has had a significant impact on voltage endurance characteristics of electrical insulation. Improved time-to-breakdown behavior, resulting in reduced aging of insulation, and enhanced thermal stability are of considerable importance in industrial applications. This chapter discusses several specific aspects of nanodielectrics and their role in the future of electrical insulation and dielectric sciences.
Date: January 1, 2009
Creator: Tuncer, Enis & Sauers, Isidor
System: The UNT Digital Library
Genomics of Secondary Metabolism in Populus: Interactions With Biotic and Abiotic Environments (open access)

Genomics of Secondary Metabolism in Populus: Interactions With Biotic and Abiotic Environments

Populus trees face constant challenges from the environment during their life cycle. To ensure their survival and reproduction, Populus trees deploy various types of defenses, one of which is the production of a myriad of secondary metabolites. Compounds derived from the shikimate-phenylpropanoid pathway are the most abundant class of secondary metabolites synthesized in Populus. Among other major classes of secondary metabolites in Populus are terpenoids and fatty acid-derivatives. Some of the secondary metabolites made by Populus trees have been functionally characterized. Some others have been associated with certain biological/ecological processes, such as defense against insects and microbial pathogens or acclimation or adaptation to abiotic stresses. Functions of many Populus secondary metabolites remain unclear. The advent of various novel genomic tools will enable us to explore in greater detail the complexity of secondary metabolism in Populus. Detailed data mining of the Populus genome sequence can unveil candidate genes of secondary metabolism. Metabolomic analysis will continue to identify new metabolites synthesized in Populus. Integrated genomics that combines various omics tools will prove to be the most powerful approach in revealing the molecular and biochemical basis underlying the biosynthesis of secondary metabolites in Populus. Characterization of the biological/ecological functions of secondary metabolites as …
Date: January 1, 2009
Creator: Chen, Feng; Liu, Chang-Jun; Tschaplinski, Timothy J & Zhao, Nan
System: The UNT Digital Library
Proceedings of the 4th Annual Workshop on Cyber Security and Information Intelligence Research: Developing Strategies To Meet The Cyber Security And Information Intelligence Challenges Ahead (open access)

Proceedings of the 4th Annual Workshop on Cyber Security and Information Intelligence Research: Developing Strategies To Meet The Cyber Security And Information Intelligence Challenges Ahead

As our dependence on the cyber infrastructure grows ever larger, more complex and more distributed, the systems that compose it become more prone to failures and/or exploitation. Intelligence is information valued for its currency and relevance rather than its detail or accuracy. Information explosion describes the pervasive abundance of (public/private) information and the effects of such. Gathering, analyzing, and making use of information constitutes a business- / sociopolitical- / military-intelligence gathering activity and ultimately poses significant advantages and liabilities to the survivability of "our" society. The combination of increased vulnerability, increased stakes and increased threats make cyber security and information intelligence (CSII) one of the most important emerging challenges in the evolution of modern cyberspace "mechanization." The goal of the workshop was to challenge, establish and debate a far-reaching agenda that broadly and comprehensively outlined a strategy for cyber security and information intelligence that is founded on sound principles and technologies. We aimed to discuss novel theoretical and applied research focused on different aspects of software security/dependability, as software is at the heart of the cyber infrastructure.
Date: January 1, 2008
Creator: Sheldon, Frederick T; Krings, Axel; Abercrombie, Robert K & Mili, Ali
System: The UNT Digital Library
Quantitative Assessment of Robot-generated Maps (open access)

Quantitative Assessment of Robot-generated Maps

Mobile robotic mapping is now considered to be a sufficiently mature field with demonstrated successes in various domains. While much progress has been made in the development of computationally efficient and consistent mapping schemes, it is still murky, at best, on how these maps can be evaluated. We are motivated by the absence of an accepted standard for quantitatively measuring the performance of robotic mapping systems against user-defined requirements. It is our belief that the development of standardized methods for quantitatively evaluating existing robotic technologies will improve the utility of mobile robots in already established application areas, such as vacuum cleaning, robot surveillance, and bomb disposal. This approach will also enable the proliferation and acceptance of such technologies in emerging markets. This chapter summarizes our preliminary efforts by bringing together the research community towards addressing this important problem which has ramifications not only from researchers perspective but also from consumers, robot manufacturers, and developers viewpoints.
Date: January 1, 2009
Creator: Scrapper, Chris; Madhavan, Raj & Lakaemper, Rolf
System: The UNT Digital Library
Proteomic Insights: Cryoadaption of Permafrost Bacteria (open access)

Proteomic Insights: Cryoadaption of Permafrost Bacteria

The permafrost microbial community has been described as 'a community of survivors' (Friedman 1994). Because of the permanently cold condition and the long term isolation of the permafrost sediments, the permafrost microorganisms have acquired various adaptive features in the membrane, enzymes, and macromolecular synthesis. This chapter reviews the different adaptive mechanisms used by permafrost microorganisms with a focus on the proteomic level of cryoadaptation that have recently been identified during the low temperature growth in permafrost bacteria.
Date: January 1, 2009
Creator: Qiu, Yinghua; Vishnivetskaya, Tatiana A. & Lubman, David M.
System: The UNT Digital Library
Bacteria in Permafrost (open access)

Bacteria in Permafrost

Significant numbers of viable ancient microorganisms are known to be present within the permafrost. They have been isolated in both polar regions from the cores up to 400 m deep and ground temperatures of -27 C. The age of the cells corresponds to the longevity of the permanently frozen state of the soils, with the oldest cells dating back to {approx}3 million years in the Arctic, and {approx}5 million years in the Antarctic. They are the only life forms known to have retained viability over geological time. Thawing of the permafrost renews their physiological activity and exposes ancient life to modern ecosystems. Thus, the permafrost represents a stable and unique physicochemical complex, which maintains life incomparably longer than any other known habitats. If we take into account the depth of the permafrost layers, it is easy to conclude that they contain a total microbial biomass many times higher than that of the soil cover. This great mass of viable matter is peculiar to permafrost only.
Date: January 1, 2008
Creator: Gilichinsky, David A.; Vishnivetskaya, Tatiana A.; Petrova, Maya A.; Spirina, Elena V.; Mamikin, Vladimir & Rivkina, Elizaveta
System: The UNT Digital Library
Virtual Human Problem Solving Environments (open access)

Virtual Human Problem Solving Environments

Abstract. Interest in complex integrated digital or virtual human modeling has seen a significant increase over the last decade. Coincident with that increased interest, Oak Ridge National Laboratory (ORNL) initiated the development of a human simulation tool, the Virtual Human. The Virtual Human includes a problem-solving environment (PSE) for implementing the integration of physiological models in different programming languages and connecting physiological function to anatomy. The Virtual Human PSE (VHPSE) provides the computational framework with which to develop the concept of a "Virtual Human." Supporting the framework is a data definition for modeling parameters, PhysioML, a Virtual Human Database (VHDB), and a Web-based graphical user interface (GUI) developed using Java. Following description of the VHPSE, we discuss four example implementations of models within the framework. Further expansion of a human modeling environment was carried out in the Defense Advanced Research Projects Agency Virtual Soldier Project. SCIRun served as the Virtual Soldier problem solving environment (VSPSE). We review and compare specific developments in these projects that have significant potential for the future of Virtual Human modeling and simulation. We conclude with an evaluation of areas of future work that will provide important extensions to the VHPSE and VSPSE and make possible …
Date: January 1, 2008
Creator: Ward, Richard C.; Pouchard, Line Catherine; Munro, Nancy B. & Fischer, Sarah Kathleen
System: The UNT Digital Library
Viable Cyanobacteria and Green Algae from the Permafrost Darkness (open access)

Viable Cyanobacteria and Green Algae from the Permafrost Darkness

This review represents an overview of the existence, distribution and abundance of the photoautotrophic microorganisms in the deep subsurface permafrost of the Northeast Russia and McMurdo Dry Valleys, Antarctica. The morphology, growth rate, spectral properties, phylogenetic position of the viable permafrost green algae and cyanobacteria have been studied. Viable photoautotrophs were represented by unicellular green algae and filamentous cyanobacteria with low growth rate. Spectral studies of ancient cyanobacteria and green algae did not reveal any significant differences between them and their contemporary relatives. Phylogenetic analyses have shown that permafrost photoautotrophs were closely related to strains and more often to uncultured environmental clones from cold regions.
Date: January 1, 2009
Creator: Vishnivetskaya, Tatiana A.
System: The UNT Digital Library
Density Functional Theory/A Practical Introduction (open access)

Density Functional Theory/A Practical Introduction

None
Date: January 1, 2009
Creator: Sholl, D. S. & Steckel, J. A.
System: The UNT Digital Library
Electron Holography of Electromagnetic Fields - Recent Theoretical Advances. (open access)

Electron Holography of Electromagnetic Fields - Recent Theoretical Advances.

It has been shown in this work that the Fourier space approach can be fruitfully applied to the calculation of the fields and the associated electron optical phase shift of several magnetic and electrostatic structures, like superconducting vortices in conventional and high-T{sub c} superconductors, reverse biased p-n junctions, magnetic domains and nanoparticles. In all these cases, this novel approach has led to unexpected but extremely interesting results, very often expressed in analytical form, which allow the quantitative and reliable interpretation of the experimental data collected by means of electron holography or of more conventional Lorentz microscopy techniques. Moreover, it is worth recalling that whenever long-range electromagnetic fields are involved, a physical model of the object under investigation is necessary in order to take into account correctly the perturbation of the reference wave induced by the tail of the field protruding into the vacuum. For these reasons, we believe that the Fourier space approach for phase computations we have introduced and discussed in this chapter will represent an invaluable tool for the investigation of electromagnetic fields at the meso- and nano-scale.
Date: January 1, 2007
Creator: Beleggia, M.; Pozzi, G. & Tonomura, A.
System: The UNT Digital Library
Self-Organized Criticality and Cellular Automata (open access)

Self-Organized Criticality and Cellular Automata

Cellular automata provide a fascinating class of dynamical systems based on very simple rules of evolution yet capable of displaying highly complex behavior. These include simplified models for many phenomena seen in nature. Among other things, they provide insight into self-organized criticality, wherein dissipative systems naturally drive themselves to a critical state with important phenomena occurring over a wide range of length and the scales. This article begins with an overview of self-organized criticality. This is followed by a discussion of a few examples of simple cellular automaton systems, some of which may exhibit critical behavior. Finally, some of the fascinating exact mathematical properties of the Bak-Tang-Wiesenfeld sand-pile model [1] are discussed.
Date: January 1, 2007
Creator: Creutz, M.
System: The UNT Digital Library
Genome Sequence Databases (Overview): Sequencing and Assembly (open access)

Genome Sequence Databases (Overview): Sequencing and Assembly

From the date its role in heredity was discovered, DNA has been generating interest among scientists from different fields of knowledge: physicists have studied the three dimensional structure of the DNA molecule, biologists tried to decode the secrets of life hidden within these long molecules, and technologists invent and improve methods of DNA analysis. The analysis of the nucleotide sequence of DNA occupies a special place among the methods developed. Thanks to the variety of sequencing technologies available, the process of decoding the sequence of genomic DNA (or whole genome sequencing) has become robust and inexpensive. Meanwhile the assembly of whole genome sequences remains a challenging task. In addition to the need to assemble millions of DNA fragments of different length (from 35 bp (Solexa) to 800 bp (Sanger)), great interest in analysis of microbial communities (metagenomes) of different complexities raises new problems and pushes some new requirements for sequence assembly tools to the forefront. The genome assembly process can be divided into two steps: draft assembly and assembly improvement (finishing). Despite the fact that automatically performed assembly (or draft assembly) is capable of covering up to 98% of the genome, in most cases, it still contains incorrectly assembled reads. …
Date: January 1, 2009
Creator: Lapidus, Alla L.
System: The UNT Digital Library
Proceedings of the 5th Annual Workshop on Cyber Security and Information Intelligence Research: Cyber Security and Information Intelligence Challenges and Strategies (open access)

Proceedings of the 5th Annual Workshop on Cyber Security and Information Intelligence Research: Cyber Security and Information Intelligence Challenges and Strategies

Our reliance on the cyber infrastructure has further grown and the dependencies have become more complex. The infrastructure and applications running on it are not generally governed by the rules of bounded systems and inherit the properties of unbounded systems, such as the absence of global control, borders and barriers. Furthermore, the quest for increasing functionality and ease of operation is often at the cost of controllability, potentially opening up avenues for exploitation and failures. Intelligence is information valued for its currency and relevance rather than its detail or accuracy. In the presence of information explosion, i.e., the pervasive abundance of (public/private) information and the effects of such, intelligence has the potential to shift the advantages in the dynamic game of defense and attacks in cyber space. Gathering, analyzing, and making use of information constitutes a business-/sociopolitical-/military-intelligence gathering activity and ultimately poses significant advantages and liabilities to the survivability of "our" society. The combination of increased vulnerability, increased stakes and increased threats make cyber security and information intelligence (CSII) one of the most important emerging challenges in the evolution of modern cyberspace. The goal of the workshop is to establish, debate and challenge the far-reaching agenda that broadly and comprehensively …
Date: January 1, 2009
Creator: Sheldon, Frederick T; Peterson, Greg D; Krings, Axel; Abercrombie, Robert K & Mili, Ali
System: The UNT Digital Library
A Simple Distributed Particle Swarm Optimization for Dynamic and Noisy Environments (open access)

A Simple Distributed Particle Swarm Optimization for Dynamic and Noisy Environments

In this paper, we present a Simple Distributed Particle Swarm Optimization (SDPSO) algorithm that can be used to track the optimal solution in a dynamic and noisy environment. The classic PSO algorithm lacks the ability to track changing optimum in a dynamic environment. Several approaches have been investigated to enhance the PSO algorithm s ability in dynamic environments. However, in dealing with dynamic environments, these approaches have lost PSO s original strengths of decentralized control and ease of implementation. The SDPSO algorithm proposed in this paper maintains these classic PSO features as well as provides the optimum result tracking capability in dynamic environments. In this research, the DF1 multimodal dynamic environment generator proposed by Morrison and De Jong is used to evaluate the classic PSO, SDPSO and other two adaptive PSOs.
Date: January 1, 2009
Creator: Cui, Xiaohui & Potok, Thomas E
System: The UNT Digital Library
HIGH PERFORMANCE PLASMAS ON THE NATIONAL SPHERICAL TORUS EXPERIMENT (open access)

HIGH PERFORMANCE PLASMAS ON THE NATIONAL SPHERICAL TORUS EXPERIMENT

The National Spherical Torus Experiment has produced toroidal plasmas at low aspect ratio (A = R/a = 0.86d0.68m - 1.3, where R is the major radius and a is the minor radius of the torus) with plasma currents of 1.4MA. The rapid development of the machine has led to very exciting physics results during the first full year of physics operation. Pulse lengths in excess of 0.5s have been obtained with inductive current drive. Up to 4MW of High Harmonic Fast Wave (HHFW) heating power has been applied with 6MW planned. Using only 2MW of HHFW heating power clear evidence of electron heating is sden with HHFW, as observed by the multi point Thomson scattering diagnostic. A non-inductive current drive concept known as Coaxial Helicity Injection (CHI) has driven 260kA of toroidal current. Neutral beam heating power of 5MW has been injected. Plasmas with PI ( =2p0<p>/B2 = a measure of magnetic confinement efficiency) of 22% have been achieved, as calculated using the EFIT equilibrium reconstruction code. P limiting phenomena have been observed, and the maximum p, scales with I&z& High frequency (>MHz) magnetic fluctuations have been observed. H-mode plasmas are observed with confinement times of > 100ms. Beam heated …
Date: January 1, 2001
Creator: Gates, D. & Peng, Yueng Kay Martin
System: The UNT Digital Library
CFD Simulation of Airflow in Ventilated Wall System Report #9 (open access)

CFD Simulation of Airflow in Ventilated Wall System Report #9

The objective of this report was to examine air movements in vinyl and brick ventilation cavities in detail, using a state of the art CFD commercial modeling tool. The CFD activity was planned to proceed the other activities in order to develop insight on the important magnitudes of scales occurring during ventilation air flow. This information generated by the CFD model was to be used to modify (if necessary) and to validate the air flow dynamics already imbedded in the hygrothermal model for the computer-based air flow simulation procedures. A comprehensive program of advanced, state-of-the-art hygrothermal modeling was then envisaged mainly to extend the knowledge to other wall systems and at least six representative climatic areas. These data were then to be used to provide the basis for the development of design guidelines. CFD results provided timely and much needed answers to many of the concerns and questions related to ventilation flows due to thermal buoyancy and wind-driven flow scenarios. The relative strength between these two mechanisms. Simple correlations were developed and are presented in the report providing the overall pressure drop, and flow through various cavities under different exterior solar and temperature scenarios. Brick Rainscreen Wall: It was initially …
Date: January 1, 2004
Creator: Stovall, Therese K & Karagiozis, Achilles N
System: The UNT Digital Library
Energy Design Guidelines for High Performance Schools: Hot and Dry Climates (open access)

Energy Design Guidelines for High Performance Schools: Hot and Dry Climates

School districts around the country are finding that smart energy choices can help them save money and provide healthier, more effective learning environments. By incorporating energy improvements into their construction or renovation plans, schools can significantly reduce energy consumption and costs. These savings can be redirected to educational needs such as additional teachers, instructional materials, or new computers. These design guidelines outline high performance principles for the new or retrofit design of your K-12 school. By incorporating these principles, you can create an exemplary building that is both energy and resource efficient.
Date: January 1, 2002
Creator: unknown
System: The UNT Digital Library
Assessing the Potential for Renewable Energy on National Forest System Lands (open access)

Assessing the Potential for Renewable Energy on National Forest System Lands

This technical report and CD for the U.S. Department of Agriculture, Forest Service (USFS), evaluates the potential for renewable energy resource development on National Forest System (NFS) lands. USFS can use the report findings to consider potential for development of solar and wind energy resources on NFS lands, in land management decisions. The Geographical Information System (GIS) based analysis resulted in the following findings: (1) Ninety-nine National Forest Units have high potential for power production from one or more of these solar and wind energy sources; and (2) Twenty National Forest Units in nine states have high potential for power production from two or more of these solar and wind energy sources.
Date: January 1, 2005
Creator: unknown
System: The UNT Digital Library
State Energy Program Operations Manual (Revised) (open access)

State Energy Program Operations Manual (Revised)

This manual outlines and explains in detail, the procedures state energy offices need to follow to receive grants from the U.S. Department of Energy under its State Energy Program (SEP).
Date: January 1, 2003
Creator: unknown
System: The UNT Digital Library