878 research outputs found

    Modeling and Analysis of Multiple Engine Aircraft Configurations for Fault Tolerant Control

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    A formal framework is presented that allows for the analysis of the potential for using engine thrust control for aircraft actuator failure accommodation. Three sets of parameters have been identified as critical: number of engines and their position, engine thrust and throttle dynamics, and type and severity of the actuator failure. A mathematical model was developed that allows for the determination of the values of some of the parameters when the others are imposed such as determining the thrust control authority when the engine locations and Euler angles are known. Additionally, the engine locations can be determined when the thrust control authority and engine Euler angles are known and the engine Euler angles can be determined when the engine locations and thrust control authority are known. A MATLAB/Simulink simulation environment was built around a model of a large transport that can accommodate up to ten engines at different locations. A fuzzy logic controller was designed and employed for failure accommodation. The fuzzy logic controller utilizes the pilot lateral, longitudinal, and directional commands as well as the aircraft\u27s pitch attitude, roll attitude, yaw attitude and respective angular rates as the inputs to the system and provides throttle commands for each engine based on its location with respect to the aircraft\u27s center of mass. Failures of varying severity on the rudder, left or right aileron, and left or right elevator were implemented. The controller was capable of accommodating an extremely severe aileron failure and moderately severe rudder failure without additional pilot input. The controller was capable of mitigating some of the pilot command required for a moderate elevator failure. The simulation environment was used to verify the analytical results and to demonstrate the fault tolerant capabilities of multiple engine configurations. It proved to be a flexible and efficient tool for analysis and control system development

    Judicial Recusal: On the Brink of Constitutional Change

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    Recusal, or judicial disqualification, occurs when a judge abstains from a particular legal proceeding because of a personal conflict of interest. All levels of the judicial system and some administrative agencies in the United States apply the concept of recusal, but this study focuses on the United States Supreme Court. Title 28 of the United States Code provides standards (not obligatory by legal means) on when Supreme Court Justices should recuse themselves. But Supreme Court Justices are themselves the arbiters of their own recusal and often these substantive standards are not met. The method of study applied is theoretical, using both quantitative and qualitative data from past Supreme Court cases

    Juvenile salmon density on marsh surfaces versus within tidal channels

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    Use of tidal marsh surfaces by juvenile salmon in Pacific Northwest estuaries has generally been ignored by ecologists, engineers and planners involved in salmon habitat restoration. In contrast, fish use of marsh plains has been documented in many other parts of the world. Are Pacific Northwest marshes an exception to the pattern of fish use that is so common elsewhere? For three consecutive years, fish were sampled bi-monthly in tidal channels and on tidal marsh plains of the Skagit Delta to answer this question. Juvenile Chinook and chum salmon, as well as sticklebacks were the most consistently caught and abundant fish in channels and on the marsh surface, but eight other fish species were also found on the marsh surface. While fish densities were much higher in tidal channels than on marsh surfaces, marsh surface area was much greater than channel area, so sticklebacks and juvenile chum were potentially 50% more numerous on the marsh surface than in channels. However, due to their high channel densities, juvenile Chinook were nevertheless more abundant in tidal channels than on the marsh surface; those on the marsh surface amounted to 40% of those in tidal channels. The ratio of marsh surface to channel fish density peaks late in the season for all three fish species, which may be a response to increased prey production over the marsh plain. The substantial use of the marsh surface by juvenile salmon that we observed suggests estuarine habitat restoration for salmon recovery should not neglect the direct value of vegetated marsh plains to juvenile salmon. Tidal marsh habitat for juvenile salmon is more than just tidal channels. Partial habitat restoration that only restores tidal flow to channels and not to adjacent marshes, e.g., using self-regulating tide gates (SRTs), has a direct impact on juvenile salmon habitat use

    A tetraspecific VHH-based neutralizing antibody modifies disease outcome in three animal models of Clostridium difficile infection

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    Clostridium difficile infection (CDI), a leading cause of nosocomial infection, is a serious disease in North America, Europe, and Asia. CDI varies greatly from asymptomatic carriage to life-threatening diarrhea, toxic megacolon, and toxemia. The incidence of community-acquired infection has increased due to the emergence of hypervirulent antibiotic-resistant strains. These new strains contribute to the frequent occurrence of disease relapse, complicating treatment, increasing hospital stays, and increasing morbidity and mortality among patients. Therefore, it is critical to develop new therapeutic approaches that bypass the development of antimicrobial resistance and avoid disruption of gut microflora. Here, we describe the construction of a single heteromultimeric VHH-based neutralizing agent (VNA) that targets the two primary virulence factors of Clostridium difficile, toxins A (TcdA) and B (TcdB). Designated VNA2-Tcd, this agent has subnanomolar toxin neutralization potencies for both C. difficile toxins in cell assays. When given systemically by parenteral administration, VNA2-Tcd protected against CDI in gnotobiotic piglets and mice and to a lesser extent in hamsters. Protection from CDI was also observed in gnotobiotic piglets treated by gene therapy with an adenovirus that promoted the expression of VNA2-Tcd

    Sympathy, empathy, and compassion: A grounded theory study of palliative care patientsā€™ understandings, experiences, and preferences

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    Background: Compassion is considered an essential element in quality patient care. One of the conceptual challenges in healthcare literature is that compassion is often confused with sympathy and empathy. Studies comparing and contrasting patientsā€™ perspectives of sympathy, empathy, and compassion are largely absent. Aim: The aim of this study was to investigate advanced cancer patientsā€™ understandings, experiences, and preferences of ā€œsympathy,ā€ ā€œempathy,ā€ and ā€œcompassionā€ in order to develop conceptual clarity for future research and to inform clinical practice. Design: Data were collected via semi-structured interviews and then independently analyzed by the research team using the three stages and principles of Straussian grounded theory. Setting/participants: Data were collected from 53 advanced cancer inpatients in a large urban hospital. Results: Constructs of sympathy, empathy, and compassion contain distinct themes and sub-themes. Sympathy was described as an unwanted, pity-based response to a distressing situation, characterized by a lack of understanding and self-preservation of the observer. Empathy was experienced as an affective response that acknowledges and attempts to understand individualā€™s suffering through emotional resonance. Compassion enhanced the key facets of empathy while adding distinct features of being motivated by love, the altruistic role of the responder, action, and small, supererogatory acts of kindness. Patients reported that unlike sympathy, empathy and compassion were beneficial, with compassion being the most preferred and impactful. Conclusion: Although sympathy, empathy, and compassion are used interchangeably and frequently conflated in healthcare literature, patients distinguish and experience them uniquely. Understanding patientsā€™ perspectives is important and can guide practice, policy reform, and future research

    Fine map of the Gct1 spontaneous ovarian granulosa cell tumor locus

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    The spontaneous development of juvenile-onset, ovarian granulosa cell (GC) tumors in the SWR/Bm (SWR) inbred mouse strain is a model for juvenile-type GC tumors that appear in infants and young girls. GC tumor susceptibility is supported by multiple Granulosa cell tumor (Gct) loci, but the Gct1 locus on Chr 4 derived from SWR strain background is fundamental for GC tumor development and uniquely responsive to the androgenic precursor dehydroepiandrosterone (DHEA). To resolve the location of Gct1 independently from other susceptibility loci, Gct1 was isolated in a congenic strain that replaces the distal segment of Chr 4 in SWR mice with a 47Ā Ć—Ā 10(6)-bp genomic segment from the Castaneus/Ei (CAST) strain. SWR females homozygous for the CAST donor segment were confirmed to be resistant to DHEA- and testosterone-induced GC tumorigenesis, indicating successful exchange of CAST alleles (Gct1(CA)) for SWR alleles (Gct1(SW)) at this tumor susceptibility locus. A series of nested, overlapping, congenic sublines was created to fine-map Gct1 based on GC tumor susceptibility under the influence of pubertal DHEA treatment. Twelve informative lines have resolved the Gct1 locus to a 1.31Ā Ć—Ā 10(6)-bp interval on mouse Chr 4, a region orthologous to human Chr 1p36.22. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00335-012-9439-6) contains supplementary material, which is available to authorized users

    Density-dependent and landscape effects upon estuary rearing in Chinook salmon: insights from long-term monitoring in four Puget Sound estuaries

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    Juvenile Chinook salmon are well known for utilizing estuarine habitats within the tidal delta for rearing during outmigration. Several studies have linked population responses to availability of estuary habitat, and support the hypothesis that estuarine habitats are vital rearing areas for juvenile Chinook salmon. However, these coarse-scale studies provide little insight on how specific estuarine habitats contribute to rearing potential for salmon. We integrate long-term monitoring data from four estuaries of Puget Sound (Nooksack, Skagit, Snohomish, and Nisqually) to examine whether 1) Chinook populations in these rivers are limited by restricted estuary habitat, 2) hatchery releases can influence density dependent relationships in estuaries, 3) highly connected sites support higher densities of salmon, and 4) different habitat types support higher rearing densities of Chinook salmon. Across sampling locations within estuary systems, average annual rearing densities varied over four orders of magnitude. We found strong support for density dependence, habitat type, landscape connectivity, and hatchery release numbers influencing rearing densities, although all factors were not necessarily as important within each system, and effects of habitat type were particularly variable. Further work using bioenergetics models suggest that habitat-dependent variation in temperature can strongly influence growth in different systems, and that multiple habitats are likely important to provide suitable habitat for extended estuary rearing. These analyses are useful for determining the relative contribution of connectivity, cohort population size, and local habitat conditions for growth potential of Chinook salmon using estuarine habitats at early life stages, and shed light on likely impacts of climate change upon rearing conditions

    The Vehicle, Fall 1988

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    Table of Contents Cover LetterBob Zordanipage 3 Letter to Harrington StreetBob Zordanipage 4 The Only TruthBob Zordanipage 5 They\u27d Gone to a MovieMatt Mansfieldpage 6 The LocketMonica Grothpage 6 The Sleep of BabesMonica Grothpage 7 Techni-Color Characters in a Black and White TownMonica Grothpage 8 The HorseRodger Patiencepage 9 ValaciaRobyn Kerrpage 10 Gatsby\u27s LightJim Reedpage 11 Millions of MeJim Reedpage 12 View from the StreetsSteven M. Beamerpage 13 When Headlights on the HighwayMichael Salempage 23 Concrete AffairsMichael Salempage 24 The Middle of the StreetMichael Salempage 25 Scent of a StormMichael Salempage 26 The FishermanAngie Geraldpage 27 OrgansPatrick Peterspage 33 CarpentryPatrick Peterspage 34 FishingPatrick Peterspage 35 Autumn Poem for a Friend In a Printing PlantPatrick Peterspage 36https://thekeep.eiu.edu/vehicle/1051/thumbnail.jp

    The Vehicle, Fall 1988

    Get PDF
    Table of Contents Cover LetterBob Zordanipage 3 Letter to Harrington StreetBob Zordanipage 4 The Only TruthBob Zordanipage 5 They\u27d Gone to a MovieMatt Mansfieldpage 6 The LocketMonica Grothpage 6 The Sleep of BabesMonica Grothpage 7 Techni-Color Characters in a Black and White TownMonica Grothpage 8 The HorseRodger Patiencepage 9 ValaciaRobyn Kerrpage 10 Gatsby\u27s LightJim Reedpage 11 Millions of MeJim Reedpage 12 View from the StreetsSteven M. Beamerpage 13 When Headlights on the HighwayMichael Salempage 23 Concrete AffairsMichael Salempage 24 The Middle of the StreetMichael Salempage 25 Scent of a StormMichael Salempage 26 The FishermanAngie Geraldpage 27 OrgansPatrick Peterspage 33 CarpentryPatrick Peterspage 34 FishingPatrick Peterspage 35 Autumn Poem for a Friend In a Printing PlantPatrick Peterspage 36https://thekeep.eiu.edu/vehicle/1051/thumbnail.jp
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