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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
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
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
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
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
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