912 research outputs found

    The Socio-economic and Religious Aspects in Robinson Crusoe

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    In the novel, Robinson Crusoe, Daniel Defoe examines a wide range of complex issues. Defoe takes the typical adventure theme and transforms it into a thought-provoking reflection of many issues involving society. A blending of economic and religious issues is created by first focusing on economy, then bringing the issue of religion in, and finally allowing for the portrayal of the interpenetration between each. Defoe proves that it is possible to live by economic practices and monetary values while still maintaining a good, moral character. The emphasis on economic issues is extremely apparent, as Defoe calls into question the concept of money and its value, as well as its place in society. Crusoe is first portrayed as a man defined by money and ruled by economic principles. Even when removed from society, he is impelled to practice many economic conventions, such as investment, moderation and the idea of profit. Defoe creates Crusoe to be so greatly influenced by money and the economy in the beginning so as to better emphasize the intertwining of his economic side with his religious side. The Christian values and morals of Crusoe dominate the latter part of the novel. He rediscovers the Bible and its teachings and learns the importance of repentance and giving thanks. The provocative progression in unveiling the many layers of Crusoe allows for the reader to see that the man they thought to be defined by money is rather a man trying to live by the Word of God

    Insights into the Chlamydial Niche: The Dynamic Roles of Inclusion Membrane (Inc) Proteins in Chlamydia trachomatis Development

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    Chlamydia trachomatis (Ctr) is the leading cause of bacterial sexually transmitted infections. Ctr, an obligate intracellular bacterium, develops within a membrane-bound vacuole called an inclusion. The inclusion membrane is modified by chlamydial inclusion membrane (Inc) proteins, the functions of which are poorly characterized. Bacterial two-hybrid analyses found some Incs (e.g., IncF) interacted with numerous Incs while others (e.g., IncA) did not. We hypothesize that some Incs organize the inclusion through Inc-Inc interactions whereas other Incs promote chlamydial-host interactions by binding eukaryotic proteins. To test our hypothesis, we implemented the ascorbate peroxidase proximity labeling system (APEX2), which labels proximal proteins with biotin in vivo. We transformed Ctr with inducible expression constructs containing incF-APEX2, incATM(transmembrane domain)-APEX2, incA-APEX2, and APEX2 alone. Affinity purification-mass spectrometry (AP-MS) of biotinylated proteins from chlamydial infected monolayers, followed by Significance Analysis of INTeractome (SAINT), was used to identify significant proteins that are proximal to the Inc-APEX2 constructs from five biological replicates. Consistent with our hypothesis, IncF-APEX2 biotinylated more chlamydial Inc proteins, whereas IncA-APEX2 biotinylated more unique eukaryotic proteins. We validated a SAINT significant eukaryotic protein, LRRF1, at the inclusion membrane by immunofluorescence and determined that the Inc CT226 interacts with LRRF1. Next, we compared our datasets with other AP-MS inclusion studies, finding only seven proteins that were similarly identified, likely a reflection of the different experimental approaches. Importantly, for the first time, we were able to directly compare two Inc-APEX2 studies, which also revealed fewer similarly identified proteins than expected. This led us to hypothesize that the overexpression of certain Incs may alter the organization of the inclusion membrane. Previously, we described defects in inclusion expansion and the production of progeny when IncF-APEX2 was expressed at high levels from transformed Ctr. To further investigate the role of Incs in chlamydial development, we transformed Ctr with inducible expression plasmids containing FLAG-tagged incF, ct813, and ct226. The expression of IncF and CT813, but not CT226, altered inclusion development, as observed by smaller inclusions and decreased IncE intensity in the inclusion membrane. These data suggest that coordinated Inc expression and insertion into the inclusion membrane is essential for optimal inclusion development

    A Study on the Parallelization of Terrain-Covering Ant Robots Simulations

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    Agent-based simulation is used as a tool for supporting (time-critical) decision making in differentiated contexts. Hence, techniques for speeding up the execution of agent-based models, such as Parallel Discrete Event Simulation (PDES), are of great relevance/benefit. On the other hand, parallelism entails that the final output provided by the simulator should closely match the one provided by a traditional sequential run. This is not obvious given that, for performance and efficiency reasons, parallel simulation engines do not allow the evaluation of global predicates on the simulation model evolution with arbitrary time-granularity along the simulation time-Axis. In this article we present a study on the effects of parallelization of agent-based simulations, focusing on complementary aspects such as performance and reliability of the provided simulation output. We target Terrain Covering Ant Robots (TCAR) simulations, which are useful in rescue scenarios to determine how many agents (i.e., robots) should be used to completely explore a certain terrain for possible victims within a given time. © 2014 Springer-Verlag Berlin Heidelberg

    Railway/Highway At-Grade Crossing Surface Rehabilitation Manual: Recommendations and Guides

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    This Railway/Highway At-Grade Crossing Surface Rehabilitation Manual offers guidance to engineers and project planners for designing, constructing, and managing railway/highway crossing rehabilitation projects. The manual includes information on pre-project administration, project execution, and post-project management and oversight. Suggestions are provided for determining the most cost-effective rehabilitation procedure, techniques to insure the appropriate installation procedures are followed onsite, and instructions for post-project administration and inspection procedures. The primary goal of this manual is to aid with the implementation of a crossing rehabilitation program; all of its guidance underscores the importance of achieving costeffective solutions through the use of best practices to build crossings that are safe and smooth, perform at a high level, and have a long service life, which benefits railroads as well the driving public

    Effects of zooplankton size and concentration and light intensity on the feeding behavior of Atlantic mackerel \u3cem\u3eScomber scombrus\u3c/em\u3e

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    Atlantic mackerel Scomber scombrus had low clearance rates when fed older stage copepodites of the copepod Calanus finmarchicus at high concentrations and high clearance rates at low concentrations. These rates were consistent with filter feeding at high concentrations and particulate feeding at low concentrations. Intermediate and small copepods presented together at high concentrations were cleared at lower rates than the large C. finmarchicus, suggesting lower filtration efficiencies. Intermediate and small copepods were presented over a range of light intensities (8.2 x 10-8 to 1.6 x 100 µE m-2 s-1). Feeding rate did not change significantly between 1.6 x 100 and 2.0 x 10-6 µE m-2 s-1, but decreased to nearly zero at 8.2 x 10-8 µE m-2 s-1, indicating a light intensity threshold for feeding of about 10-7 µE m-2 s-1. This threshold enables mackerel to feed throughout the night near the ocean surface. Swimming speed decreased to a lesser degree than feeding rate at the lowest light intensity, indicating that the change in filter-feeding rate is only partially due to the change in speed. The school dispersed in both low and high light levels, but spacing between fish did not appear to be related to feeding rate

    Recommendations for KYTC’s Railway/Highway At-Grade Crossing Surface Management Practices

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    An ideal Railway/Highway At-Grade Crossing Management program involves selecting costeffective practices when designing new crossings and rehabilitating existing crossings. This report outlines two strategies to enhance KYTC’s existing program. First, it describes a process that uses decision-option diagrams to optimize the assessment and implementation of engineering solutions in order to restore desired smoothness, minimize settlement in the postconstruction phase, and foster acceptable long-term performance of crossings following their rehabilitation. Decision-option diagrams rely on assessments that are site-specific and based on historical performance, the present observed performance and condition, and the measureable parameters specific to particular crossings. To supplement this process, the second strategy that this report proposes is the establishment of an effective managerial structure at KYTC that streamlines decision-making to ensure that the selected design is properly applied and implemented. Taken together, these proposals will significantly improve the state’s ability to systematically and cost-effectively repair deteriorated crossings

    CSM Testbed Development and Large-Scale Structural Applications

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    A research activity called Computational Structural Mechanics (CSM) conducted at the NASA Langley Research Center is described. This activity is developing advanced structural analysis and computational methods that exploit high-performance computers. Methods are developed in the framework of the CSM Testbed software system and applied to representative complex structural analysis problems from the aerospace industry. An overview of the CSM Testbed methods development environment is presented and some new numerical methods developed on a CRAY-2 are described. Selected application studies performed on the NAS CRAY-2 are also summarized
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