Maintain and Regain Well Clear: Maneuver Guidance Designs for Pilots Performing the Detect-and-Avoid Task

NASA Technical Reports Server (NTRS)

Monk, Kevin J.; Roberts, Zachary

2017-01-01

In order to support the future expansion and integration of Unmanned Aircraft Systems (UAS), ongoing research efforts have sought to produce findings that inform the minimum display information elements required for acceptable UAS pilot response times and traffic avoidance. Previous simulations have revealed performance benefits associated with DAA displays containing predictive information and suggestive maneuver guidance tools in the form of banding. The present study investigated the impact of various maneuver guidance display configurations on detect-and-avoid (DAA) task performance in a simulated airspace environment. UAS pilots ability to maintain DAA well clear was compared between displays with either the presence or absence of green DAA bands, which indicated conflict-free flight regions. Additional display comparisons assessed pilots ability to regain DAA well clear with two different guidance presentations designed to aid in DAA well clear recovery during critical encounters. Performance implications and display considerations for future UAS DAA systems are discussed.

An Evaluation of Detect and Avoid (DAA) Displays for Unmanned Aircraft Systems: The Effect of Information Level and Display Location on Pilot Performance

NASA Technical Reports Server (NTRS)

Fern, Lisa; Rorie, R. Conrad; Pack, Jessica S.; Shively, R. Jay; Draper, Mark H.

2015-01-01

A consortium of government, industry and academia is currently working to establish minimum operational performance standards for Detect and Avoid (DAA) and Control and Communications (C2) systems in order to enable broader integration of Unmanned Aircraft Systems (UAS) into the National Airspace System (NAS). One subset of these performance standards will need to address the DAA display requirements that support an acceptable level of pilot performance. From a pilot's perspective, the DAA task is the maintenance of self separation and collision avoidance from other aircraft, utilizing the available information and controls within the Ground Control Station (GCS), including the DAA display. The pilot-in-the-loop DAA task requires the pilot to carry out three major functions: 1) detect a potential threat, 2) determine an appropriate resolution maneuver, and 3) execute that resolution maneuver via the GCS control and navigation interface(s). The purpose of the present study was to examine two main questions with respect to DAA display considerations that could impact pilots' ability to maintain well clear from other aircraft. First, what is the effect of a minimum (or basic) information display compared to an advanced information display on pilot performance? Second, what is the effect of display location on UAS pilot performance? Two levels of information level (basic, advanced) were compared across two levels of display location (standalone, integrated), for a total of four displays. The authors propose an eight-stage pilot-DAA interaction timeline from which several pilot response time metrics can be extracted. These metrics were compared across the four display conditions. The results indicate that the advanced displays had faster overall response times compared to the basic displays, however, there were no significant differences between the standalone and integrated displays. Implications of the findings on understanding pilot performance on the DAA task, the development of DAA display performance standards, as well as the need for future research are discussed.

IEEE/AIAA/NASA Digital Avionics Systems Conference, 9th, Virginia Beach, VA, Oct. 15-18, 1990, Proceedings

NASA Technical Reports Server (NTRS)

1990-01-01

The present conference on digital avionics discusses vehicle-management systems, spacecraft avionics, special vehicle avionics, communication/navigation/identification systems, software qualification and quality assurance, launch-vehicle avionics, Ada applications, sensor and signal processing, general aviation avionics, automated software development, design-for-testability techniques, and avionics-software engineering. Also discussed are optical technology and systems, modular avionics, fault-tolerant avionics, commercial avionics, space systems, data buses, crew-station technology, embedded processors and operating systems, AI and expert systems, data links, and pilot/vehicle interfaces.

UAS in the NAS Flight Test Series 4 Overview

NASA Technical Reports Server (NTRS)

Murphy, Jim

2016-01-01

Flight Test Series 4 (FT4) provides the researchers with an opportunity to expand on the data collected during the first flight tests. Following Flight Test Series 3, additional scripted encounters with different aircraft performance and sensors will be conducted. FT4 is presently planned for Spring of 2016 to ensure collection of data to support the validation of the final RTCA Phase 1 DAA (Detect and Avoid) Minimum Operational Performance Standards (MOPS). There are three research objectives associated with this goal: Evaluate the performance of the DAA system against cooperative and non-cooperative aircraft encounters Evaluate UAS (Unmanned Aircraft Systems) pilot performance in response to DAA maneuver guidance and alerting with live intruder encounters Evaluate TCAS/DAA (Traffic Alert and Collision Avoidance System/Detect and Avoid) interoperability. This flight test series will focus on only the Scripted Encounters configuration, supporting the collection of data to validate the interoperability of DAA and collision avoidance algorithms.

The Generic Resolution Advisor and Conflict Evaluator (GRACE) for Detect-And-Avoid Systems

NASA Technical Reports Server (NTRS)

Abramson, Michael; Refai, Mohamad; Santiago, Confesor

2017-01-01

Java Architecture for Detect-And-Avoid (DAA) Extensibility and Modeling (JADEM) was developed at NASA Ames Research Center as a research and modeling tool for Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS). UAS will be required to have DAA systems in order to fulfill the regulatory requirement to remain well clear'' of other traffic. JADEM supports research on technological requirements and Minimum Operational Performance Standards (MOPS) for UAS DAA systems by providing a flexible and extensible software platform that includes models and algorithms for all major DAA functions. This paper describes one of these algorithms, the Generic Resolution Advisor and Conflict Evaluator (GRACE). GRACE supports two core DAA functions: threat evaluation and guidance. GRACE is generic in the sense that it is designed to work with any aircraft or sensor type (both cooperative and non-cooperative), and to be used in various applications and DAA guidance concepts, thus supporting evolving MOPS requirements and research. GRACE combines flexibility, robustness, and computational efficiency. It has modest memory requirements and can handle multiple cooperative and noncooperative intruders. GRACE has been used as a core JADEM component in several real-time and fast-time experiments, including human-in-the-loop simulations and live flight tests.

Piloted "Well Clear" Performance Evaluation of Detect-and-Avoid Systems with Suggestive Guidance

NASA Technical Reports Server (NTRS)

Mueller, Eric R.; Santiago, Confesor; Watza, Spencer

2016-01-01

This study evaluated the performance of four prototype unmanned aircraft detect-and-avoid (DAA) display configurations, each with different informational elements driven by alerting and guidance algorithms. Sixteen unmanned aircraft pilots flew each combination of the display configurations, with half being given zero DAA surveillance sensor uncertainty and the other half experiencing errors that were comparable, and in some cases slightly better than, errors that were measured in DAA system flight tests. The displays that showed intruder alert information in altitude and heading bands had significantly fewer losses of well clear compared with alternative displays that lacked that information. This difference was significant from a statistical and practical perspective: those losses that did occur lasted for shorter periods and did not penetrate as far into the geometric "separation cylinder" as those in the non-banded displays. A modest level of DAA surveillance sensor uncertainty did not affect the proportion of losses of well clear or their severity. It is recommended that DAA traffic displays implement a band-type display in order to improve the safety of UAS operations in the National Airspace System. Finally, this report provides pilot response time distributions for responding to DAA alerts.

DAIDALUS Observations From UAS Integration in the NAS Project Flight Test 4

NASA Technical Reports Server (NTRS)

Vincent, Michael J.; Tsakpinis, Dimitrios

2016-01-01

In order to validate the Unmanned Aerial System (UAS) Detect-and-Avoid (DAA) solution proposed by standards body RTCA Inc., the National Aeronautics and Space Administration (NASA) UAS Integration in the NAS project, alongside industry members General Atomics and Honeywell, conducted the fourth flight test in a series at Armstrong Flight Research Center in Edwards, California. Flight Test 4 (FT4) investigated problems of interoperability with the TCAS collision avoidance system with a DAA system as well as problems associated with sensor uncertainty. A series of scripted flight encounters between the NASA Ikhana UAS and various "intruder" aircraft were flown while alerting and guidance from the DAA algorithm were recorded to investigate the timeliness of the alerts and correctness of the guidance triggered by the DAA system. The results found that alerts were triggered in a timely manner in most instances. Cases where the alerting and guidance was incorrect were investigated further.

Unmanned Aircraft Systems Minimum Operations Performance Standards End-to-End Verification and Validation (E2-V2) Simulation

NASA Technical Reports Server (NTRS)

Ghatas, Rania W.; Jack, Devin P.; Tsakpinis, Dimitrios; Vincent, Michael J.; Sturdy, James L.; Munoz, Cesar A.; Hoffler, Keith D.; Dutle, Aaron M.; Myer, Robert R.; Dehaven, Anna M.;

Digital avionics systems - Principles and practices (2nd revised and enlarged edition)

NASA Technical Reports Server (NTRS)

Spitzer, Cary R.

1993-01-01

The state of the art in digital avionics systems is surveyed. The general topics addressed include: establishing avionics system requirements; avionics systems essentials in data bases, crew interfaces, and power; fault tolerance, maintainability, and reliability; architectures; packaging and fitting the system into the aircraft; hardware assessment and validation; software design, assessment, and validation; determining the costs of avionics.

Warning Alert HITL Experiment Results

NASA Technical Reports Server (NTRS)

Monk, Kevin J.; Ferm, Lisa; Roberts, Zach

2018-01-01

Minimum Operational Performance Standards (MOPS) are being developed to support the integration of Unmanned Aircraft Systems (UAS) in the National Airspace (NAS). Input from subject matter experts and multiple research studies have informed display requirements for Detect-and-Avoid (DAA) systems aimed at supporting timely and appropriate pilot responses to collision hazards. Phase 1 DAA MOPS alerting is designed to inform pilots if an avoidance maneuver is necessary; the two highest alert levels - caution and warning - indicate how soon pilot action is required and whether there is adequate time to coordinate with the air traffic controller (ATC). Additional empirical support is needed to clarify the extent to which warning-level alerting impacts DAA task performance. The present study explores the differential effects of the auditory and visual cues provided by the DAA Warning alert, and performance implications compared to caution-only alerting are discussed.

AIAA Aviation UAS DAA Demonstration-Mini HITL Week 2 Stats

NASA Technical Reports Server (NTRS)

Fern, Lisa Carolynn; Murphy, James R.; Jovic, Srboljub

2016-01-01

The UAS-NAS Project demo will showcase recent research efforts to ensure the interoperability between proposed UAS detect and avoid (DAA) human machine interface requirements (developed within RTCA SC-228) and existing collision avoidance displays. Attendees will be able to view the current state of the art of the DAA pilot traffic, alerting and guidance displays integrated with Traffic advisory and Collision Avoidance (TCAS) II in the UAS-NAS Project's research UAS ground control station (developed in partnership with the Air Force Research Laboratory). In addition, attendees will have the opportunity to interact with the research UAS ground control station and "fly" encounters, using the DAA and TCAS II displays to avoid simulated aircraft. The display of the advisories will be hosted on a laptop with an external 30" monitor, running the Vigilant Spririt system. DAA advisories will be generated by the JADEM software tool, connected to the system via the LVC Gateway. A repeater of the primary flight display will be shown on a 55" tv/monitor mounted on a stand at the back of the booth to show the pilot interaction to the passersby.

SSI-ARC Flight Test 3 Data Review

NASA Technical Reports Server (NTRS)

Gong, Chester; Wu, Minghong G.

2015-01-01

The "Unmanned Aircraft System (UAS) Integration into the National Airspace System (NAS)" Project conducted flight test program, referred to as Flight Test 3, at Armstrong Flight Research Center from June - August 2015. Four flight test days were dedicated to the NASA Ames-developed Detect and Avoid (DAA) System referred to as Autoresolver. The encounter scenarios, which involved NASA's Ikhana UAS and a manned intruder aircraft, were designed to collect data on DAA system performance in real-world conditions and uncertainties with four different surveillance sensor systems. Resulting flight test data and analysis results will be used to evaluate the DAA system performance (e.g., trajectory prediction accuracy, threat detection) and to add fidelity to simulation models used to inform Minimum Operating Performance Standards (MOPS) for integrating UAS into routine NAS operations.

Future mobile access for open-data platforms and the BBC-DaaS system

NASA Astrophysics Data System (ADS)

Edlich, Stefan; Singh, Sonam; Pfennigstorf, Ingo

2013-03-01

In this paper, we develop an open data platform on multimedia devices to act as marketplace of data for information seekers and data providers. We explore the important aspects of Data-as-a-Service (DaaS) service in the cloud with a mobile access point. The basis of the DaaS service is to act as a marketplace for information, utilizing new technologies and recent new scalable polyglot architectures based on NoSql databases. Whereas Open-Data platforms are beginning to be widely accepted, its mobile use is not. We compare similar products, their approach and a possible mobile usage. We discuss several approaches to address the mobile access as a native app, html5 and a mobile first approach together with the several frontend presentation techniques. Big data visualization itself is in the early days and we explore some possibilities to get big data / open data accessed by mobile users.

Ensuring Interoperability between UAS Detect-and-Avoid and Manned Aircraft Collision Avoidance

NASA Technical Reports Server (NTRS)

Thipphavong, David; Cone, Andrew; Lee, Seung Man; Santiago, Confesor

2017-01-01

The UAS community in the United States has identified the need for a collision avoidance region in which UAS Detect-and-Avoid (DAA) vertical guidance is restricted to preclude interoperability issues with manned aircraft collision avoidance system vertical resolution advisories (RAs). This paper documents the process by which the collision avoidance region was defined. Three candidate definitions were evaluated on 1.3 million simulated pairwise encounters between UAS and manned aircraft covering a wide range of horizontal and vertical closure rates, angles, and miss distances. They were evaluated with regard to UAS DAA interoperability with manned aircraft collision avoidance systems in terms of: 1) the primary objective of restricting DAA vertical guidance before RAs when the aircraft are close, and 2) the secondary objective of avoiding unnecessary restrictions of DAA vertical guidance at a DAA alert when the aircraft are further apart. The collision avoidance region definition that fully achieves the primary objective and best achieves the secondary objective was recommended to and accepted by the UAS community in the United States. By this definition, UAS and manned aircraft are in the collision avoidance region--during which DAA vertical guidance is restricted--when the time to closest point of approach is less than 50 seconds and either the time to co-altitude is less than 50 seconds or the current vertical separation is less than 800 feet.

Ensuring Interoperability Between Unmanned Aircraft Detect-and-Avoid and Manned Aircraft Collision Avoidance

NASA Technical Reports Server (NTRS)

Thipphavong, David; Cone, Andrew; Lee, Seungman

2017-01-01

The Unmanned Aircraft Systems (UAS) community in the United States has identified the need for a collision avoidance region in which UAS Detect-and-Avoid (DAA) vertical guidance is restricted to preclude interoperability issues with manned aircraft collision avoidance system vertical resolution advisories (RAs). This paper documents the process by which the collision avoidance region was defined. Three candidate definitions were evaluated on 1.3 million simulated pairwise encounters between UAS and manned aircraft covering a wide range of horizontal and vertical closure rates, angles, and miss distances. Each definition was evaluated with regard to UAS DAA interoperability with manned aircraft collision avoidance in terms of how well it achieved: 1) the primary objective of restricting DAA vertical guidance prior to RAs when the aircraft are close, and 2) the secondary objective of avoiding unnecessary restrictions of DAA vertical guidance at DAA alerts when the aircraft are further apart. The collision avoidance region definition that fully achieves the primary objective and best achieves the secondary objective was recommended to and accepted by the UAS community in the United States. By this definition, UAS and manned aircraft are in the collision avoidance region where DAA vertical guidance is restricted when the time to closest point of approach (CPA) is less than 50 seconds and either the time to co-altitude is less than 50 seconds or the current vertical separation is less than 800 feet.

Space shuttle engineering and operations support. Avionics system engineering

NASA Technical Reports Server (NTRS)

Broome, P. A.; Neubaur, R. J.; Welsh, R. T.

1976-01-01

The shuttle avionics integration laboratory (SAIL) requirements for supporting the Spacelab/orbiter avionics verification process are defined. The principal topics are a Spacelab avionics hardware assessment, test operations center/electronic systems test laboratory (TOC/ESL) data processing requirements definition, SAIL (Building 16) payload accommodations study, and projected funding and test scheduling. Because of the complex nature of the Spacelab/orbiter computer systems, the PCM data link, and the high rate digital data system hardware/software relationships, early avionics interface verification is required. The SAIL is a prime candidate test location to accomplish this early avionics verification.

Hepatitis B Virus Reactivation Associated With Direct-Acting Antiviral Therapy for Chronic Hepatitis C Virus: A Review of Cases Reported to the U.S. Food and Drug Administration Adverse Event Reporting System.

PubMed

Bersoff-Matcha, Susan J; Cao, Kelly; Jason, Mihaela; Ajao, Adebola; Jones, S Christopher; Meyer, Tamra; Brinker, Allen

2017-06-06

Direct-acting antiviral agents (DAAs) are used increasingly to treat hepatitis C virus (HCV) infection. Reports were published recently on hepatitis B virus (HBV) reactivation (HBV-R) in patients with HBV-HCV co-infection. Hepatitis B virus reactivation, defined as an abrupt increase in HBV replication in patients with inactive or resolved HBV infection, may result in clinically significant hepatitis. To assess whether HBV-R is a safety concern in patients receiving HCV DAAs. Descriptive case series. U.S. Food and Drug Administration (FDA) Adverse Event Reporting System (FAERS). 29 patients with HBV-R receiving HCV DAAs. Clinical and laboratory data. The FDA identified 29 unique reports of HBV-R in patients receiving DAAs from 22 November 2013 to 15 October 2016. Two cases resulted in death and 1 case in liver transplantation. Patients in whom HBV-R developed were heterogeneous regarding HCV genotype, DAAs received, and baseline HBV characteristics. At baseline, 9 patients had a detectable HBV viral load, 7 had positive results on hepatitis B surface antigen (HBsAg) testing and had an undetectable HBV viral load, and 3 had negative results on HBsAg testing and had an undetectable HBV viral load. For the remaining 10 patients, data points were not reported or the data were uninterpretable. Despite provider knowledge of baseline HBV, HBV-R diagnosis and treatment were delayed in 7 cases and possibly 7 others. The quality of information varied among reports. Because reporting is voluntary, HBV-R associated with DAAs likely is underreported. Hepatitis B virus reactivation is a newly identified safety concern in patients with HBV-HCV co-infection treated with DAAs. Patients with a history of HBV require clinical monitoring while receiving DAA therapy. Studies would help determine the risk factors for HBV-R, define monitoring frequency, and identify patients who may benefit from HBV prophylaxis and treatment. DAAs remain a safe and highly effective treatment for the management of HCV infection. None.

Unmanned Aircraft Systems Detect and Avoid System: End-to-End Verification and Validation Simulation Study of Minimum Operations Performance Standards for Integrating Unmanned Aircraft into the National Airspace System

NASA Technical Reports Server (NTRS)

Ghatas, Rania W.; Jack, Devin P.; Tsakpinis, Dimitrios; Sturdy, James L.; Vincent, Michael J.; Hoffler, Keith D.; Myer, Robert R.; DeHaven, Anna M.

2017-01-01

As Unmanned Aircraft Systems (UAS) make their way to mainstream aviation operations within the National Airspace System (NAS), research efforts are underway to develop a safe and effective environment for their integration into the NAS. Detect and Avoid (DAA) systems are required to account for the lack of "eyes in the sky" due to having no human on-board the aircraft. The technique, results, and lessons learned from a detailed End-to-End Verification and Validation (E2-V2) simulation study of a DAA system representative of RTCA SC-228's proposed Phase I DAA Minimum Operational Performance Standards (MOPS), based on specific test vectors and encounter cases, will be presented in this paper.

Avionics System Architecture for NASA Orion Vehicle

NASA Technical Reports Server (NTRS)

Baggerman, Clint

2010-01-01

This viewgraph presentation reviews the Orion Crew Exploration Vehicle avionics architecture. The contents include: 1) What is Orion?; 2) Orion Concept of Operations; 3) Orion Subsystems; 4) Orion Avionics Architecture; 5) Orion Avionics-Network; 6) Orion Network Unification; 7) Orion Avionics-Integrity; 8) Orion Avionics-Partitioning; and 9) Orion Avionics-Redundancy.

Cost-effectiveness analysis of two treatment strategies for chronic hepatitis C before and after access to direct-acting antivirals in Spain.

PubMed

Turnes, Juan; Domínguez-Hernández, Raquel; Casado, Miguel Ángel

To evaluate the cost-effectiveness of a strategy based on direct-acting antivirals (DAAs) following the marketing of simeprevir and sofosbuvir (post-DAA) versus a pre-direct-acting antiviral strategy (pre-DAA) in patients with chronic hepatitis C, from the perspective of the Spanish National Health System. A decision tree combined with a Markov model was used to estimate the direct health costs (€, 2016) and health outcomes (quality-adjusted life years, QALYs) throughout the patient's life, with an annual discount rate of 3%. The sustained virological response, percentage of patients treated or not treated in each strategy, clinical characteristics of the patients, annual likelihood of transition, costs of treating and managing the disease, and utilities were obtained from the literature. The cost-effectiveness analysis was expressed as an incremental cost-effectiveness ratio (incremental cost per QALY gained). A deterministic sensitivity analysis and a probabilistic sensitivity analysis were performed. The post-DAA strategy showed higher health costs per patient (€30,944 vs. €23,707) than the pre-DAA strategy. However, it was associated with an increase of QALYs gained (15.79 vs. 12.83), showing an incremental cost-effectiveness ratio of €2,439 per QALY. The deterministic sensitivity analysis and the probabilistic sensitivity analysis showed the robustness of the results, with the post-DAA strategy being cost-effective in 99% of cases compared to the pre-DAA strategy. Compared to the pre-DAA strategy, the post-DAA strategy is efficient for the treatment of chronic hepatitis C in Spain, resulting in a much lower cost per QALY than the efficiency threshold used in Spain (€30,000 per QALY). Copyright © 2017 Elsevier España, S.L.U., AEEH y AEG. All rights reserved.

Alternate concepts study extension. Volume 2: Part 4: Avionics

NASA Technical Reports Server (NTRS)

1971-01-01

A recommended baseline system is presented along with alternate avionics systems, Mark 2 avionics, booster avionics, and a cost summary. Analyses and discussions are included on the Mark 1 orbiter avionics subsystems, electrical ground support equipment, and the computer programs. Results indicate a need to define all subsystems of the baseline system, an installation study to determine the impact on the crew station, and a study on access for maintenance.

Design of an Ada expert system shell for the VHSIC avionic modular flight processor

NASA Technical Reports Server (NTRS)

Fanning, F. Jesse

1992-01-01

The Embedded Computer System Expert System Shell (ES Shell) is an Ada-based expert system shell developed at the Avionics Laboratory for use on the VHSIC Avionic Modular Processor (VAMP) running under the Ada Avionics Real-Time Software (AARTS) Operating System. The ES Shell provides the interface between the expert system and the avionics environment, and controls execution of the expert system. Testing of the ES Shell in the Avionics Laboratory's Integrated Test Bed (ITB) has demonstrated its ability to control a non-deterministic software application executing on the VAMP's which can control the ITB's real-time closed-loop aircraft simulation. The results of these tests and the conclusions reached in the design and development of the ES Shell have played an important role in the formulation of the requirements for a production-quality expert system inference engine, an ingredient necessary for the successful use of expert systems on the VAMP embedded avionic flight processor.

A study of compositional verification based IMA integration method

NASA Astrophysics Data System (ADS)

Huang, Hui; Zhang, Guoquan; Xu, Wanmeng

2018-03-01

The rapid development of avionics systems is driving the application of integrated modular avionics (IMA) systems. But meanwhile it is improving avionics system integration, complexity of system test. Then we need simplify the method of IMA system test. The IMA system supports a module platform that runs multiple applications, and shares processing resources. Compared with federated avionics system, IMA system is difficult to isolate failure. Therefore, IMA system verification will face the critical problem is how to test shared resources of multiple application. For a simple avionics system, traditional test methods are easily realizing to test a whole system. But for a complex system, it is hard completed to totally test a huge and integrated avionics system. Then this paper provides using compositional-verification theory in IMA system test, so that reducing processes of test and improving efficiency, consequently economizing costs of IMA system integration.

Avionics System Architecture Tool

NASA Technical Reports Server (NTRS)

Chau, Savio; Hall, Ronald; Traylor, marcus; Whitfield, Adrian

2005-01-01

Avionics System Architecture Tool (ASAT) is a computer program intended for use during the avionics-system-architecture- design phase of the process of designing a spacecraft for a specific mission. ASAT enables simulation of the dynamics of the command-and-data-handling functions of the spacecraft avionics in the scenarios in which the spacecraft is expected to operate. ASAT is built upon I-Logix Statemate MAGNUM, providing a complement of dynamic system modeling tools, including a graphical user interface (GUI), modeling checking capabilities, and a simulation engine. ASAT augments this with a library of predefined avionics components and additional software to support building and analyzing avionics hardware architectures using these components.

ISHM-oriented adaptive fault diagnostics for avionics based on a distributed intelligent agent system

NASA Astrophysics Data System (ADS)

Xu, Jiuping; Zhong, Zhengqiang; Xu, Lei

2015-10-01

In this paper, an integrated system health management-oriented adaptive fault diagnostics and model for avionics is proposed. With avionics becoming increasingly complicated, precise and comprehensive avionics fault diagnostics has become an extremely complicated task. For the proposed fault diagnostic system, specific approaches, such as the artificial immune system, the intelligent agents system and the Dempster-Shafer evidence theory, are used to conduct deep fault avionics diagnostics. Through this proposed fault diagnostic system, efficient and accurate diagnostics can be achieved. A numerical example is conducted to apply the proposed hybrid diagnostics to a set of radar transmitters on an avionics system and to illustrate that the proposed system and model have the ability to achieve efficient and accurate fault diagnostics. By analyzing the diagnostic system's feasibility and pragmatics, the advantages of this system are demonstrated.

ACES M and S: Unmitigated Factorial Encounter Study on DAA/TCAS Interoperability

NASA Technical Reports Server (NTRS)

Thipphavong, David; Cone, Andrew; Park, Chunki; Lee, Seung Man; Santiago, Confesor

2016-01-01

Realization of the expected proliferation of Unmanned Aircraft System (UAS) operations in the National Airspace System (NAS) depends on the development and validation of standards for UAS Detect and Avoid (DAA) Systems. The RTCA Special Committee 228 is charged with leading the development of draft Minimum Operational Performance Standards (MOPS) for UAS DAA Systems. NASA, as a participating member of RTCA SC-228 is committed to supporting the development and validation of draft requirements for DAA alerting and guidance systems. This presentation contains the results of two combinatorial encounter analysis studies using NASA's SAA Control fast-time simulation capability for this purpose. In these studies, encounters between two aircraft were simulated one at a time for the full factorial combination of encounter geometries (e.g., encounter angle, CPA offset) and aircraft performance (e.g., ownership and intruder ground speeds and vertical rates). The first study analyzes the relationships (e.g., timeline) between the different alerting-safety regions in the SC-228 MOPS (in order of increasing severity): 1) DAA warning alert, 2) well clear recovery (WCR) guidance, 3) DAA-Collision Avoidance (CA), and 4) TCAS RA. This study will focus primarily on encounter situations in which TCAS RA occurs prior to any of the other alerting-safety boundaries. In particular, this study will investigate whether using vertical distance or vertical distance at closest point of approach (i.e., vertical miss distance or VMD) is more appropriate for the definition of the DAA-CA region. In addition, cases where transitions between different regions skip an intermediate region will be analyzed. The second study in this presentation explores a proposal to use an altitude rate error threshold to determine if vertical maneuvers are acceptable for DAA WCR guidance against non-cooperative intruders. This study incorporates the radar from the Honeywell sensor model and examines a series of pairwise encounters between a non-cooperative intruder and a UAS ownship, with different combinations of intruder states and ownship performance levels. The study uses SAA Control as a simulation platform and pilot model, and Omnibands to provide DWC recovery guidance. Two simulation sets, one that allows vertical DWC recovery guidance and one that does not, are compared to determine if encounters with altitude rate errors above 250 feet-per-minute are more likely to have more severe losses of well clear, as determined by the Loss of Well-Clear Severity metric.

The relationship between an advanced avionic system architecture and the elimination of the need for an Avionics Intermediate Shop (AIS)

NASA Astrophysics Data System (ADS)

Abraham, S. J.

While Avionics Intermediate Shops (AISs) have in the past been required for military aircraft, the emerging VLSI/VHSIC technology has given rise to the possibility of novel, well partitioned avionics system architectures that obviate the high spare parts costs that formerly prompted and justified the existence of an AIS. Future avionics may therefore be adequately and economically supported by a two-level maintenance system. Algebraic generalizations are presented for the analysis of the spares costs implications of alternative design partitioning schemes for future avionics.

NASA UAS Integration into the NAS Project: Human Systems Integration

NASA Technical Reports Server (NTRS)

Shively, Jay

2016-01-01

This presentation provides an overview of the work the Human Systems Integration (HSI) sub-project has done on detect and avoid (DAA) displays while working on the UAS (Unmanned Aircraft System) Integration into the NAS project. The most recent simulation on DAA interoperability with Traffic Collision Avoidance System (TCAS) is discussed in the most detail. The relationship of the work to the larger UAS community and next steps are also detailed.

UAS Integration in the NAS Project: Flight Test 3 Data Analysis of JADEM-Autoresolver Detect and Avoid System

NASA Technical Reports Server (NTRS)

Gong, Chester; Wu, Minghong G.; Santiago, Confesor

2016-01-01

The Unmanned Aircraft Systems Integration in the National Airspace System project, or UAS Integration in the NAS, aims to reduce technical barriers related to safety and operational challenges associated with enabling routine UAS access to the NAS. The UAS Integration in the NAS Project conducted a flight test activity, referred to as Flight Test 3 (FT3), involving several Detect-and-Avoid (DAA) research prototype systems between June 15, 2015 and August 12, 2015 at the Armstrong Flight Research Center (AFRC). This report documents the flight testing and analysis results for the NASA Ames-developed JADEM-Autoresolver DAA system, referred to as 'Autoresolver' herein. Four flight test days (June 17, 18, 22, and July 22) were dedicated to Autoresolver testing. The objectives of this test were as follows: 1. Validate CPA prediction accuracy and detect-and-avoid (DAA, formerly known as self-separation) alerting logic in realistic flight conditions. 2. Validate DAA trajectory model including maneuvers. 3. Evaluate TCAS/DAA interoperability. 4. Inform final Minimum Operating Performance Standards (MOPS). Flight test scenarios were designed to collect data to directly address the objectives 1-3. Objective 4, inform final MOPS, was a general objective applicable to the UAS in the NAS project as a whole, of which flight test is a subset. This report presents analysis results completed in support of the UAS in the NAS project FT3 data review conducted on October 20, 2015. Due to time constraints and, to a lesser extent, TCAS data collection issues, objective 3 was not evaluated in this analysis.

NAS-Wide Fast-Time Simulation Study for Evaluating Performance of UAS Detect-and-Avoid Alerting and Guidance Systems

NASA Technical Reports Server (NTRS)

Lee, Seung Man; Park, Chunki; Cone, Andrew Clayton; Thipphavong, David P.; Santiago, Confesor

2016-01-01

This presentation contains the analysis results of NAS-wide fast-time simulations with UAS and VFR traffic for a single day for evaluating the performance of Detect-and-Avoid (DAA) alerting and guidance systems. This purpose of this study was to help refine and validate MOPS alerting and guidance requirements. In this study, we generated plots of all performance metrics that are specified by RTCA SC-228 Minimum Operational Performance Standards (MOPS): 1) to evaluate the sensitivity of alerting parameters on the performance metrics of each DAA alert type: Preventive, Corrective, and Warning alerts and 2) to evaluate the effect of sensor uncertainty on DAA alerting and guidance performance.

Avionics systems integration technology

NASA Technical Reports Server (NTRS)

Stech, George; Williams, James R.

1988-01-01

A very dramatic and continuing explosion in digital electronics technology has been taking place in the last decade. The prudent and timely application of this technology will provide Army aviation the capability to prevail against a numerically superior enemy threat. The Army and NASA have exploited this technology explosion in the development and application of avionics systems integration technology for new and future aviation systems. A few selected Army avionics integration technology base efforts are discussed. Also discussed is the Avionics Integration Research Laboratory (AIRLAB) that NASA has established at Langley for research into the integration and validation of avionics systems, and evaluation of advanced technology in a total systems context.

Roles of d-Amino Acids on the Bioactivity of Host Defense Peptides

PubMed Central

Li, Hao; Anuwongcharoen, Nuttapat; Malik, Aijaz Ahmad; Prachayasittikul, Virapong; Wikberg, Jarl E. S.; Nantasenamat, Chanin

2016-01-01

Host defense peptides (HDPs) are positively-charged and amphipathic components of the innate immune system that have demonstrated great potential to become the next generation of broad spectrum therapeutic agents effective against a vast array of pathogens and tumor. As such, many approaches have been taken to improve the therapeutic efficacy of HDPs. Amongst these methods, the incorporation of d-amino acids (d-AA) is an approach that has demonstrated consistent success in improving HDPs. Although, virtually all HDP review articles briefly mentioned about the role of d-AA, however it is rather surprising that no systematic review specifically dedicated to this topic exists. Given the impact that d-AA incorporation has on HDPs, this review aims to fill that void with a systematic discussion of the impact of d-AA on HDPs. PMID:27376281

Implementing the space shuttle data processing system with the space generic open avionics architecture

NASA Technical Reports Server (NTRS)

Wray, Richard B.; Stovall, John R.

1993-01-01

This paper presents an overview of the application of the Space Generic Open Avionics Architecture (SGOAA) to the Space Shuttle Data Processing System (DPS) architecture design. This application has been performed to validate the SGOAA, and its potential use in flight critical systems. The paper summarizes key elements of the Space Shuttle avionics architecture, data processing system requirements and software architecture as currently implemented. It then summarizes the SGOAA architecture and describes a tailoring of the SGOAA to the Space Shuttle. The SGOAA consists of a generic system architecture for the entities in spacecraft avionics, a generic processing external and internal hardware architecture, a six class model of interfaces and functional subsystem architectures for data services and operations control capabilities. It has been proposed as an avionics architecture standard with the National Aeronautics and Space Administration (NASA), through its Strategic Avionics Technology Working Group, and is being considered by the Society of Aeronautic Engineers (SAE) as an SAE Avionics Standard. This architecture was developed for the Flight Data Systems Division of JSC by the Lockheed Engineering and Sciences Company, Houston, Texas.

An avionics scenario and command model description for Space Generic Open Avionics Architecture (SGOAA)

NASA Technical Reports Server (NTRS)

Stovall, John R.; Wray, Richard B.

1994-01-01

This paper presents a description of a model for a space vehicle operational scenario and the commands for avionics. This model will be used in developing a dynamic architecture simulation model using the Statemate CASE tool for validation of the Space Generic Open Avionics Architecture (SGOAA). The SGOAA has been proposed as an avionics architecture standard to NASA through its Strategic Avionics Technology Working Group (SATWG) and has been accepted by the Society of Automotive Engineers (SAE) for conversion into an SAE Avionics Standard. This architecture was developed for the Flight Data Systems Division (FDSD) of the NASA Johnson Space Center (JSC) by the Lockheed Engineering and Sciences Company (LESC), Houston, Texas. This SGOAA includes a generic system architecture for the entities in spacecraft avionics, a generic processing external and internal hardware architecture, and a nine class model of interfaces. The SGOAA is both scalable and recursive and can be applied to any hierarchical level of hardware/software processing systems.

UAS Integration into the NAS: iHTL: DAA Display Evaluation Preliminary Results

NASA Technical Reports Server (NTRS)

Fern, Lisa; Rorie, Conrad; Shively, Jay

2014-01-01

The integrated human-in-the-loop (iHITL) simulation examined the effect of four different Detect-and-Avoid (DAA) display concepts on unmanned aircraft system (UAS) pilots' ability to maintain safe separation. The displays varied in the type and amount of guidance they provided to pilots. The study's background and methodology are discussed, followed by a presentation of the preliminary 'measured response' data (i.e., pilots' end-to-end response time in reacting to traffic alerts on their DAA display). Results indicate that display type had moderate to no affect on pilot measured response times.

Space Tug avionics definition study. Volume 2: Avionics functional requirements

NASA Technical Reports Server (NTRS)

1975-01-01

Flight and ground operational phases of the tug/shuttle system are analyzed to determine the general avionics support functions that are needed during each of the mission phases and sub-phases. Each of these general support functions is then expanded into specific avionics system requirements, which are then allocated to the appropriate avionics subsystems. This process is then repeated at the next lower level of detail where these subsystem requirements are allocated to each of the major components that comprise a subsystem.

UAS-NAS Project Demo - Mini HITL Week 2 Stats

NASA Technical Reports Server (NTRS)

Murphy, James R.; Fern, Lisa C.; Rorie, Robert C.; Shively, Robert; Jovic, Srboljub

2016-01-01

The UAS-NAS Project demo will showcase recent research efforts to ensure the interoperability between proposed UAS detect and avoid (DAA) human machine interface requirements (developed within RTCA SC-228) and existing collision avoidance displays. Attendees will be able to view the current state of the art of the DAA pilot traffic, alerting and guidance displays integrated with Traffic advisory and Collision Avoidance (TCAS) II in the UAS-NAS Project's research UAS ground control station (developed in partnership with the Air Force Research Laboratory). In addition, attendees will have the opportunity to interact with the research UAS ground control station and "fly" encounters, using the DAA and TCAS II displays to avoid simulated aircraft. The display of the advisories will be hosted on a laptop with an external 30" monitor, running the Vigilant Spirit system. DAA advisories will be generated by the JADEM software tool, connected to the system via the LVC Gateway. A repeater of the primary flight display will be shown on a 55" monitor mounted on a stand at the back of the booth to show the pilot interaction to the passersby.

Trends in transport aircraft avionics

NASA Technical Reports Server (NTRS)

Berkstresser, B. K.

1973-01-01

A survey of avionics onboard present commercial transport aircraft was conducted to identify trends in avionics systems characteristics and to determine the impact of technology advances on equipment weight, cost, reliability, and maintainability. Transport aircraft avionics systems are described under the headings of communication, navigation, flight control, and instrumentation. The equipment included in each section is described functionally. However, since more detailed descriptions of the equipment can be found in other sources, the description is limited and emphasis is put on configuration requirements. Since airborne avionics systems must interface with ground facilities, certain ground facilities are described as they relate to the airborne systems, with special emphasis on air traffic control and all-weather landing capability.

Reuse and Interoperability of Avionics for Space Systems

NASA Technical Reports Server (NTRS)

Hodson, Robert F.

2007-01-01

The space environment presents unique challenges for avionics. Launch survivability, thermal management, radiation protection, and other factors are important for successful space designs. Many existing avionics designs use custom hardware and software to meet the requirements of space systems. Although some space vendors have moved more towards a standard product line approach to avionics, the space industry still lacks similar standards and common practices for avionics development. This lack of commonality manifests itself in limited reuse and a lack of interoperability. To address NASA s need for interoperable avionics that facilitate reuse, several hardware and software approaches are discussed. Experiences with existing space boards and the application of terrestrial standards is outlined. Enhancements and extensions to these standards are considered. A modular stack-based approach to space avionics is presented. Software and reconfigurable logic cores are considered for extending interoperability and reuse. Finally, some of the issues associated with the design of reusable interoperable avionics are discussed.

Effectiveness of direct-acting antiviral therapy for hepatitis C in difficult-to-treat patients in a safety-net health system: a retrospective cohort study.

PubMed

Yek, Christina; de la Flor, Carolina; Marshall, John; Zoellner, Cindy; Thompson, Grace; Quirk, Lisa; Mayorga, Christian; Turner, Barbara J; Singal, Amit G; Jain, Mamta K

2017-11-20

Direct-acting antivirals (DAAs) have revolutionized chronic hepatitis C (HCV) treatment, but real-world effectiveness among vulnerable populations, including uninsured patients, is lacking. This study was conducted to characterize the effectiveness of DAAs in a socioeconomically disadvantaged and underinsured patient cohort. This retrospective observational study included all patients undergoing HCV treatment with DAA-based therapy between April 2014 and June 2016 at a large urban safety-net health system (Parkland Health and Hospital System, Dallas, TX, USA). The primary outcome was sustained virologic response (SVR), with secondary outcomes including treatment discontinuation, treatment relapse, and loss to follow-up. DAA-based therapy was initiated in 512 patients. The cohort was socioeconomically disadvantaged (56% uninsured and 13% Medicaid), with high historic rates of alcohol (41%) and substance (50%) use, and mental health disorders (38%). SVR was achieved in 90% of patients (n = 459); 26 patients (5%) were lost to follow-up. SVR was significantly lower in patients with decompensated cirrhosis (82% SVR; OR 0.37, 95% CI 0.16-0.85) but did not differ by insurance status (P = 0.98) or alcohol/substance use (P = 0.34). Reasons for treatment failure included loss to follow-up (n = 26, 5%), viral relapse (n = 16, 3%), non-treatment-related death (n = 7, 1%), and treatment discontinuation (n = 4, 1%). Of patients with viral relapse, 6 reported non-compliance and have not been retreated, 5 have been retreated and achieved SVR, 4 have undergone resistance testing but not yet initiated retreatment, and 1 was lost to follow-up. Effective outcomes with DAA-based therapy can be achieved in difficult-to-treat underinsured populations followed in resource-constrained safety-net health systems.

Avionics System Architecture for the NASA Orion Vehicle

NASA Technical Reports Server (NTRS)

Baggerman, Clint; McCabe, Mary; Verma, Dinesh

2009-01-01

It has been 30 years since the National Aeronautics and Space Administration (NASA) last developed a crewed spacecraft capable of launch, on-orbit operations, and landing. During that time, aerospace avionics technologies have greatly advanced in capability, and these technologies have enabled integrated avionics architectures for aerospace applications. The inception of NASA s Orion Crew Exploration Vehicle (CEV) spacecraft offers the opportunity to leverage the latest integrated avionics technologies into crewed space vehicle architecture. The outstanding question is to what extent to implement these advances in avionics while still meeting the unique crewed spaceflight requirements for safety, reliability and maintainability. Historically, aircraft and spacecraft have very similar avionics requirements. Both aircraft and spacecraft must have high reliability. They also must have as much computing power as possible and provide low latency between user control and effecter response while minimizing weight, volume, and power. However, there are several key differences between aircraft and spacecraft avionics. Typically, the overall spacecraft operational time is much shorter than aircraft operation time, but the typical mission time (and hence, the time between preventive maintenance) is longer for a spacecraft than an aircraft. Also, the radiation environment is typically more severe for spacecraft than aircraft. A "loss of mission" scenario (i.e. - the mission is not a success, but there are no casualties) arguably has a greater impact on a multi-million dollar spaceflight mission than a typical commercial flight. Such differences need to be weighted when determining if an aircraft-like integrated modular avionics (IMA) system is suitable for a crewed spacecraft. This paper will explore the preliminary design process of the Orion vehicle avionics system by first identifying the Orion driving requirements and the difference between Orion requirements and those of other previous crewed spacecraft avionics systems. Common systems engineering methods will be used to evaluate the value propositions, or the factors that weight most heavily in design consideration, of Orion and other aerospace systems. Then, the current Orion avionics architecture will be presented and evaluated.

Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) Project: Detect and Avoid Display Evaluations in Support of SC-228 Minimum Operational Performance Standards Development

NASA Technical Reports Server (NTRS)

Fern, Lisa Carolynn

2017-01-01

The primary activity for the UAS-NAS Human Systems Integration (HSI) sub-project in Phase 1 was support of RTCA Special Committee 228 Minimum Operational Performance Standards (MOPS). We provide data on the effect of various Detect and Avoid (DAA) display features with respect to pilot performance of the remain well clear function in order to determine the minimum requirements for DAA displays.

STS-2: SAIL non-avionics subsystems math model requirements

NASA Technical Reports Server (NTRS)

Bennett, W. P.; Herold, R. W.

1980-01-01

Simulation of the STS-2 Shuttle nonavionics subsystems in the shuttle avionics integration laboratory (SAIL) is necessary for verification of the integrated shuttle avionics system. The math model (simulation) requirements for each of the nonavionics subsystems that interfaces with the Shuttle avionics system is documented and a single source document for controlling approved changes (by the SAIL change control panel) to the math models is provided.

Enabling Data-as- a-Service (DaaS) - Biggest Challenge of Geoscience Australia

NASA Astrophysics Data System (ADS)

Bastrakova, I.; Kemp, C.; Car, N. J.

2016-12-01

Geoscience Australia (GA) is recognised and respected as the national repository and steward of multiple national significance data collections that provides geoscience information, services and capability to the Australian Government, industry and stakeholders. Provision of Data-as-a-Service is both GA's key responsibility and core business. Through the Science First Transformation Program GA is undergoing a significant rethinking of its data architecture, curation and access to support the Digital Science capability for which DaaS forms both a dependency and underpins its implementation. DaaS, being a service, means we can deliver its outputs in multiple ways thus providing users with data on demand in ready-for-consumption forms. We can then to reuse prebuilt data constructions to allow self-serviced integration of data underpinned by dynamic query tools. In GA's context examples of DaaS are the Australian Geoscience Data Cube, the Foundation Spatial Data Framework and data served through several Virtual Laboratories. We have implemented a three-layered architecture for DaaS in order to store and manage the data while honouring the semantics of Scientific Data Models defined by subject matter experts and GA's Enterprise Data Architecture as well as retain that delivery flexibility. The foundation layer of DaaS is Canonical Datasets, which are optimised for a long-term data stewardship and curation. Data is well structured, standardised, described and audited. All data creation and editing happen within this layer. The middle Data Transformation layer assists with transformation of data from Canonical Datasets to data integration layer. It provides mechanisms for multi-format and multi-technology data transformation. The top Data Integration layer is optimised for data access. Data can be easily reused and repurposed; data formats made available are optimised for scientific computing and adjusted for access by multiple applications, tools and libraries. Moving to DaaS enables GA to increase data alertness, generate new capabilities and be prepared for emerging technological challengers.

Avionic architecture requirements for Space Exploration Initiative systems

NASA Technical Reports Server (NTRS)

Herbella, C. G.; Brown, D. C.

1991-01-01

The authors discuss NASA's Strategic Avionics Technology Working Group (SATWG) and the results of the first study commissioned by the SATWG, the Space Avionics Requirements Study (SARS). The goal of the SARS task was to show that an open avionics architecture, using modular, standardized components, could be applied across the wide range of systems that comprise the Space Exploration Initiative. The study addressed systems ranging from expendable launch vehicles and the space station to surface systems such as Mars or lunar rovers and habitats. Top-level avionics requirements were derived from characterizations of each of the systems considered. Then a set of avionics subsystems were identified, along with estimates of the numbers and types of modules needed to meet the requirements. Applicability of these results across the infrastructure was then illustrated. In addition to these tasks, critical technologies were identified, characterized, and assessed in terms of their criticality and impact on the program. Design, development, test, and evaluation methods were addressed to identify potential areas of improvement.

The Core Avionics System for the DLR Compact-Satellite Series

NASA Astrophysics Data System (ADS)

Montenegro, S.; Dittrich, L.

2008-08-01

The Standard Satellite Bus's core avionics system is a further step in the development line of the software and hardware architecture which was first used in the bispectral infrared detector mission (BIRD). The next step improves dependability, flexibility and simplicity of the whole core avionics system. Important aspects of this concept were already implemented, simulated and tested in other ESA and industrial projects. Therefore we can say the basic concept is proven. This paper deals with different aspects of core avionics development and proposes an extension to the existing core avionics system of BIRD to meet current and future requirements regarding flexibility, availability, reliability of small satellite and the continuous increasing demand of mass memory and computational power.

System Engineering Issues for Avionics Survival in the Space Environment

NASA Technical Reports Server (NTRS)

Pavelitz, Steven

1999-01-01

This paper examines how the system engineering process influences the design of a spacecraft's avionics by considering the space environment. Avionics are susceptible to the thermal, radiation, plasma, and meteoroids/orbital debris environments. The environment definitions for various spacecraft mission orbits (LEO/low inclination, LEO/Polar, MEO, HEO, GTO, GEO and High ApogeeElliptical) are discussed. NASA models and commercial software used for environment analysis are reviewed. Applicability of technical references, such as NASA TM-4527 "Natural Orbital Environment Guidelines for Use in Aerospace Vehicle Development" is discussed. System engineering references, such as the MSFC System Engineering Handbook, are reviewed to determine how the environments are accounted for in the system engineering process. Tools and databases to assist the system engineer and avionics designer in addressing space environment effects on avionics are described and usefulness assessed.

Space Generic Open Avionics Architecture (SGOAA) reference model technical guide

NASA Technical Reports Server (NTRS)

Wray, Richard B.; Stovall, John R.

1993-01-01

This report presents a full description of the Space Generic Open Avionics Architecture (SGOAA). The SGOAA consists of a generic system architecture for the entities in spacecraft avionics, a generic processing architecture, and a six class model of interfaces in a hardware/software system. The purpose of the SGOAA is to provide an umbrella set of requirements for applying the generic architecture interface model to the design of specific avionics hardware/software systems. The SGOAA defines a generic set of system interface points to facilitate identification of critical interfaces and establishes the requirements for applying appropriate low level detailed implementation standards to those interface points. The generic core avionics system and processing architecture models provided herein are robustly tailorable to specific system applications and provide a platform upon which the interface model is to be applied.

Digital Avionics Information System (DAIS): Development and Demonstration.

DTIC Science & Technology

1981-09-01

advances in technology. The DAIS architecture results in improved reliability and availability of avionics systems while at the same time reducing life ...DAIS) represents a significant advance in the technology of avionics system architecture. DAIS is a total systems concept, exploiting standardization...configurations and fully capable of accommodating new advances in technology. These fundamental system charac- teristics are described in this report; the

Perspective on intelligent avionics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jones, H.L.

1987-01-01

Technical issues which could potentially limit the capability and acceptibility of expert systems decision-making for avionics applications are addressed. These issues are: real-time AI, mission-critical software, conventional algorithms, pilot interface, knowledge acquisition, and distributed expert systems. Examples from on-going expert system development programs are presented to illustrate likely architectures and applications of future intelligent avionic systems. 13 references.

[A new challenge in clinical practice: resistance to directly acting antivirals in hepatitis C treatment].

PubMed

Chen, Z W; Hu, P; Ren, H

2016-03-20

Directly acting antivirals (DAAs) is a major treatment of hepatitis C virus (HCV) overseas. But DAAs resistance is getting more and more clinicians' attention. DAAs have not been approved in China to date, even though some of them are in clinical trials. However, a good knowledge of DAAs resistance is important on optimizing HCV treatment regimens, increasing sustained virological response (SVR) and decreasing treatment failure in clinical. In this review, DAAs resistance mechanism and virologic barrier to resistance, the prevalence of pre-existing DAAs resistance-associated variants (RAVs), the impact of RAVs on treatment outcome, the options of treatment regimens after resistance and drug resistance testing are discussed, hoping to provide some help for DAAs' standardized treatment in China in the future.

Basic avionics module design for general aviation aircraft

NASA Technical Reports Server (NTRS)

Smyth, R. K.; Smyth, D. E.

1978-01-01

The design of an advanced digital avionics system (basic avionics module) for general aviation aircraft operated with a single pilot under IFR conditions is described. The microprocessor based system provided all avionic functions, including flight management, navigation, and lateral flight control. The mode selection was interactive with the pilot. The system used a navigation map data base to provide operation in the current and planned air traffic control environment. The system design included software design listings for some of the required modules. The distributed microcomputer uses the IEEE 488 bus for interconnecting the microcomputer and sensors.

Mitigating the Impact of Sensor Uncertainty on Unmanned Aircraft Operations

NASA Technical Reports Server (NTRS)

Jack, Devin P.; Hoffler, Keith D.; Sturdy, James L.

2017-01-01

Without a pilot onboard an aircraft, a Detect-and-Avoid (DAA) system, in conjunction with surveillance sensors, must be used to provide the remotely-located Pilot-in-Command sufficient situational awareness in order to keep the Unmanned Aircraft (UA) safely separated from other aircraft. To facilitate safe operations of UA within the U.S.' National Airspace System, the uncertainty associated with surveillance sensors must be accounted for. An approach to mitigating the impact of sensor uncertainty on achievable separation has been developed to support technical requirements for DAA systems.

Digital Avionics Information System (DAIS): Impact of DAIS Concept on Life Cycle Cost. Final Report.

ERIC Educational Resources Information Center

Goclowski, John C.; And Others

Designed to identify and quantify the potential impacts of the Digital Avionics Information System (DAIS) on weapon system personnel requirements and life cycle cost (LCC), this study postulated a typical close-air-support (CAS) mission avionics suite to serve as a basis for comparing present day and DAIS configuration specifications. The purpose…

NASA Ares I Crew Launch Vehicle Upper Stage Avionics and Software Overview

NASA Technical Reports Server (NTRS)

Nola, Charles L.; Blue, Lisa

2008-01-01

Building on the heritage of the Saturn and Space Shuttle Programs for the Design, Development, Test, and Evaluation (DDT and E) of avionics and software for NASA's Ares I Crew Launch Vehicle (CLV), the Ares I Upper Stage Element is a vital part of the Constellation Program's transportation system. The Upper Stage Element's Avionics Subsystem is actively proceeding toward its objective of delivering a flight-certified Upper Stage Avionics System for the Ares I CLV.

Modular standards for emerging avionics technologies

NASA Astrophysics Data System (ADS)

Radcliffe, B.; Boaz, J.

The present investigation is concerned with modular standards for the integration of new avionics technologies into production aircraft, taking into account also major retrofit programs. It is pointed out that avionics systems are about to undergo drastic changes in the partitioning of functions and judicious sharing of resources. These changes have the potential to significantly improve reliability and maintainability, and to reduce costs. Attention is given to a definition of the modular avionics concept, the existing module program, the development approach, development progress on the modular avionics standard, and the future of avionics installation standards.

Space Generic Open Avionics Architecture (SGOAA) standard specification

NASA Technical Reports Server (NTRS)

Wray, Richard B.; Stovall, John R.

1994-01-01

This standard establishes the Space Generic Open Avionics Architecture (SGOAA). The SGOAA includes a generic functional model, processing structural model, and an architecture interface model. This standard defines the requirements for applying these models to the development of spacecraft core avionics systems. The purpose of this standard is to provide an umbrella set of requirements for applying the generic architecture models to the design of a specific avionics hardware/software processing system. This standard defines a generic set of system interface points to facilitate identification of critical services and interfaces. It establishes the requirement for applying appropriate low level detailed implementation standards to those interfaces points. The generic core avionics functions and processing structural models provided herein are robustly tailorable to specific system applications and provide a platform upon which the interface model is to be applied.

Modular avionics packaging standardization

NASA Astrophysics Data System (ADS)

Austin, M.; McNichols, J. K.

The Modular Avionics Packaging (MAP) Program for packaging future military avionics systems with the objective of improving reliability, maintainability, and supportability, and reducing equipment life cycle costs is addressed. The basic MAP packaging concepts called the Standard Avionics Module, the Standard Enclosure, and the Integrated Rack are summarized, and the benefits of modular avionics packaging, including low risk design, technology independence with common functions, improved maintainability and life cycle costs are discussed. Progress made in MAP is briefly reviewed.

DANTi: Detect and Avoid iN The Cockpit

NASA Technical Reports Server (NTRS)

Chamberlain, James; Consiglio, Maria; Munoz, Cesar

2017-01-01

Mid-air collision risk continues to be a concern for manned aircraft operations, especially near busy non-towered airports. The use of Detect and Avoid (DAA) technologies and draft standards developed for unmanned aircraft systems (UAS), either alone or in combination with other collision avoidance technologies, may be useful in mitigating this collision risk for manned aircraft. This paper describes a NASA research effort known as DANTi (DAA iN The Cockpit), including the initial development of the concept of use, a software prototype, and results from initial flight tests conducted with this prototype. The prototype used a single Automatic Dependent Surveillance - Broadcast (ADS-B) traffic sensor and the own aircraft's position, track, heading and air data information, along with NASA-developed DAA software to display traffic alerts and maneuver guidance to manned aircraft pilots on a portable tablet device. Initial flight tests with the prototype showed a successful DANTi proof-of-concept, but also demonstrated that the traffic separation parameter set specified in the RTCA SC-228 Phase I DAA MOPS may generate excessive false alerts during traffic pattern operations. Several parameter sets with smaller separation values were also tested in flight, one of which yielded more timely alerts for the maneuvers tested. Results from this study may further inform future DANTi efforts as well as Phase II DAA MOPS development.

Requirements analysis notebook for the flight data systems definition in the Real-Time Systems Engineering Laboratory (RSEL)

NASA Astrophysics Data System (ADS)

Wray, Richard B.

1991-12-01

A hybrid requirements analysis methodology was developed, based on the practices actually used in developing a Space Generic Open Avionics Architecture. During the development of this avionics architecture, a method of analysis able to effectively define the requirements for this space avionics architecture was developed. In this methodology, external interfaces and relationships are defined, a static analysis resulting in a static avionics model was developed, operating concepts for simulating the requirements were put together, and a dynamic analysis of the execution needs for the dynamic model operation was planned. The systems engineering approach was used to perform a top down modified structured analysis of a generic space avionics system and to convert actual program results into generic requirements. CASE tools were used to model the analyzed system and automatically generate specifications describing the model's requirements. Lessons learned in the use of CASE tools, the architecture, and the design of the Space Generic Avionics model were established, and a methodology notebook was prepared for NASA. The weaknesses of standard real-time methodologies for practicing systems engineering, such as Structured Analysis and Object Oriented Analysis, were identified.

Requirements analysis notebook for the flight data systems definition in the Real-Time Systems Engineering Laboratory (RSEL)

NASA Technical Reports Server (NTRS)

Wray, Richard B.

1991-01-01

A hybrid requirements analysis methodology was developed, based on the practices actually used in developing a Space Generic Open Avionics Architecture. During the development of this avionics architecture, a method of analysis able to effectively define the requirements for this space avionics architecture was developed. In this methodology, external interfaces and relationships are defined, a static analysis resulting in a static avionics model was developed, operating concepts for simulating the requirements were put together, and a dynamic analysis of the execution needs for the dynamic model operation was planned. The systems engineering approach was used to perform a top down modified structured analysis of a generic space avionics system and to convert actual program results into generic requirements. CASE tools were used to model the analyzed system and automatically generate specifications describing the model's requirements. Lessons learned in the use of CASE tools, the architecture, and the design of the Space Generic Avionics model were established, and a methodology notebook was prepared for NASA. The weaknesses of standard real-time methodologies for practicing systems engineering, such as Structured Analysis and Object Oriented Analysis, were identified.

Applying Ada to Beech Starship avionics

NASA Technical Reports Server (NTRS)

Funk, David W.

1986-01-01

As Ada solidified in its development, it became evident that it offered advantages for avionics systems because of it support for modern software engineering principles and real time applications. An Ada programming support environment was developed for two major avionics subsystems in the Beech Starship. The two subsystems include electronic flight instrument displays and the flight management computer system. Both of these systems use multiple Intel 80186 microprocessors. The flight management computer provides flight planning, navigation displays, primary flight display of checklists and other pilot advisory information. Together these systems represent nearly 80,000 lines of Ada source code and to date approximately 30 man years of effort. The Beech Starship avionics systems are in flight testing.

The impact of direct-acting antiviral agents on liver and kidney transplant costs and outcomes.

PubMed

Axelrod, D A; Schnitzler, M A; Alhamad, T; Gordon, F; Bloom, R D; Hess, G P; Xiao, H; Nazzal, M; Segev, D L; Dharnidharka, V R; Naik, A S; Lam, N N; Ouseph, R; Kasiske, B L; Durand, C M; Lentine, K L

2018-04-27

Direct-acting antiviral medications (DAAs) have revolutionized care for hepatitis C positive (HCV+) liver (LT) and kidney (KT) transplant recipients. Scientific Registry of Transplant Recipients registry data were integrated with national pharmaceutical claims (2007-2016) to identify HCV treatments before January 2014 (pre-DAA) and after (post-DAA), stratified by donor (D) and recipient (R) serostatus and payer. Pre-DAA, 18% of HCV+ LT recipients were treated within 3 years and without differences by donor serostatus or payer. Post-DAA, only 6% of D-/R+ recipients, 19.8% of D+/R+ recipients with public insurance, and 11.3% with private insurance were treated within 3 years (P < .0001). LT recipients treated for HCV pre-DAA experienced higher rates of graft loss (adjusted hazard ratio [aHR] 1.34 1.85 2.10 , P < .0001) and death (aHR 1.47 1.68 1.91 , P < .0001). Post-DAA, HCV treatment was not associated with death (aHR 0.34 0.67 1.32 , P = .25) or graft failure (aHR 0.32 0.64 1.26 , P = .20) in D+R+ LT recipients. Treatment increased in D+R+ KT recipients (5.5% pre-DAA vs 12.9% post-DAA), but did not differ by payer status. DAAs reduced the risk of death after D+/R+ KT by 57% ( 0.19 0.43 0.95 , P = .04) and graft loss by 46% ( 0.27 0.54 1.07 , P = .08). HCV treatment with DAAs appears to improve HCV+ LT and KT outcomes; however, access to these medications appears limited in both LT and KT recipients. © 2018 The American Society of Transplantation and the American Society of Transplant Surgeons.

Systematic review with meta-analysis: recurrence of hepatocellular carcinoma following direct-acting antiviral therapy.

PubMed

Saraiya, N; Yopp, A C; Rich, N E; Odewole, M; Parikh, N D; Singal, A G

2018-05-30

Although studies suggest decreased incident hepatocellular carcinoma (HCC) after direct-acting antivirals (DAA), data are conflicting regarding HCC recurrence and aggressiveness in patients who have a history of HCC with complete response. Characterize HCC recurrence patterns after DAA therapy. Two reviewers searched MEDLINE and SCOPUS from January 2015 to December 2017 and identified studies evaluating HCC recurrence patterns following DAA therapy. A pooled estimate was calculated using the DerSimonian and Laird method for a random effects model. The study was conducted in accordance with PRISMA guidelines. Among 24 studies (n = 1820 patients), the proportion of patients with HCC recurrence following DAA therapy ranged from 0% to 59% (pooled estimate 24.4%; 95% CI: 18.4%-30.4%). Among 11 full text manuscripts, pooled HCC recurrence was 21.9% (95% CI: 16.2%-28.3%). Factors associated with recurrence included history of prior HCC recurrence and a shorter interval between HCC complete response and DAA initiation. Nine studies comparing DAA-treated and interferon-treated or untreated patients found similar recurrence among DAA-treated patients. Most (77.8%) patients with HCC recurrence were detected at an early tumour stage, of whom 64.7% received curative treatment. Study limitations included heterogeneous cohorts, potential misclassification of HCC absence prior to DAA, ascertainment bias for recurrence, and short durations of follow-up. Current data suggest acceptable HCC recurrence rates after DAA therapy, particularly if DAA therapy is delayed at least 6 months after HCC complete response. However, data characterising HCC recurrence after DAA therapy are of limited quality, highlighting the need for high quality prospective studies. © 2018 John Wiley & Sons Ltd.

Estimation of Airline Benefits from Avionics Upgrade under Preferential Merge Re-sequence Scheduling

NASA Technical Reports Server (NTRS)

Kotegawa, Tatsuya; Cayabyab, Charlene Anne; Almog, Noam

2013-01-01

Modernization of the airline fleet avionics is essential to fully enable future technologies and procedures for increasing national airspace system capacity. However in the current national airspace system, system-wide benefits gained by avionics upgrade are not fully directed to aircraft/airlines that upgrade, resulting in slow fleet modernization rate. Preferential merge re-sequence scheduling is a best-equipped-best-served concept designed to incentivize avionics upgrade among airlines by allowing aircraft with new avionics (high-equipped) to be re-sequenced ahead of aircraft without the upgrades (low-equipped) at enroute merge waypoints. The goal of this study is to investigate the potential benefits gained or lost by airlines under a high or low-equipped fleet scenario if preferential merge resequence scheduling is implemented.

Customer Avionics Interface Development and Analysis (CAIDA): Software Developer for Avionics Systems

NASA Technical Reports Server (NTRS)

Mitchell, Sherry L.

2018-01-01

The Customer Avionics Interface Development and Analysis (CAIDA) supports the testing of the Launch Control System (LCS), NASA's command and control system for the Space Launch System (SLS), Orion Multi-Purpose Crew Vehicle (MPCV), and ground support equipment. The objective of the semester-long internship was to support day-to-day operations of CAIDA and help prepare for verification and validation of CAIDA software.

An engineering approach to the use of expert systems technology in avionics applications

NASA Technical Reports Server (NTRS)

Duke, E. L.; Regenie, V. A.; Brazee, M.; Brumbaugh, R. W.

1986-01-01

The concept of using a knowledge compiler to transform the knowledge base and inference mechanism of an expert system into a conventional program is presented. The need to accommodate real-time systems requirements in applications such as embedded avionics is outlined. Expert systems and a brief comparison of expert systems and conventional programs are reviewed. Avionics applications of expert systems are discussed before the discussions of applying the proposed concept to example systems using forward and backward chaining.

Software fault tolerance for real-time avionics systems

NASA Technical Reports Server (NTRS)

Anderson, T.; Knight, J. C.

1983-01-01

Avionics systems have very high reliability requirements and are therefore prime candidates for the inclusion of fault tolerance techniques. In order to provide tolerance to software faults, some form of state restoration is usually advocated as a means of recovery. State restoration can be very expensive for systems which utilize concurrent processes. The concurrency present in most avionics systems and the further difficulties introduced by timing constraints imply that providing tolerance for software faults may be inordinately expensive or complex. A straightforward pragmatic approach to software fault tolerance which is believed to be applicable to many real-time avionics systems is proposed. A classification system for software errors is presented together with approaches to recovery and continued service for each error type.

SC-228 Inclusion of DAA Warning Alert for TCAS Interoperability

NASA Technical Reports Server (NTRS)

Fern, Lisa

2016-01-01

This white paper summarizes NASA research results that have informed Special Committee 228 (SC-228) discussions and decisions regarding the inclusion of a warning-level alert within the detect and avoid (DAA) alerting structure for unmanned aircraft systems (UAS). For UAS, the removal of the pilot from onboard the aircraft has eliminated the ability of the ground-based pilot in command (PIC) to use out-the-window visual information to make judgments about a potential threat of a loss of well clear with another aircraft. As a result, the DAA traffic display will be the primary source of information that the PIC can use to execute the three primary well clear functions: 1) detect a potential loss of well clear, 2) determine a resolution maneuver, and 3) upload that maneuver to the aircraft via the ground control station (GCS). In addition, pilots are required to coordinate with air traffic control (ATC) prior to maneuvering off of their approved flight plan. In determining an appropriate resolution maneuver to avoid a loss of well clear, the PIC must decide both when and how to maneuver, and both the timeliness and the accuracy (i.e., correctness) of the maneuver are critical to reducing the likelihood and/or severity of a loss of well clear. Alerting information is one of three critical components of the DAA display, along with traffic information elements (e.g., relative heading, speed and altitude) and maneuver guidance. Alerting information and maneuver guidance, in particular, have been found to have a significant impact, both statistically and practically, on pilots' ability to avoid and minimize the severity of losses of well clear While all three display components are key to pilots performing the traffic avoidance task of remaining well clear, in general, alerting information provides crucial information about when a resolution maneuver is required while maneuver guidance assists the pilot in determining how best to maneuver. A fundamental task of the DAA alerting system is to provide critical timing information to the pilot about the potential for a loss of well clear with another aircraft. This is done by employing both temporal and spatial thresholds that indicate to the pilot the likelihood and imminence of a loss of well clear. The design of the DAA alerting thresholds is a balancing act between eliciting the desired pilot response in real loss of well clear threat events and reducing excessive, unnecessary, and/or uncoordinated UAS maneuvering within the air traffic environment; larger thresholds, both spatially and temporally, may increase the likelihood of a pilot avoiding a loss of well clear, but it can also increase the frequency of maneuvering - especially in cases where a maneuver is not actually needed to maintain well clear. A series of human in the loop (HITL) simulations have been conducted as part of NASA's Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) project. The purpose of these HITLs has been to provide empirical results in order to inform development of the minimum human-machine interface requirements for the DAA system. This white paper will present those results which provide evidence of a human performance benefit (in terms of response times and ability to remain well clear of other aircraft) of the DAA warning alert both with and without a collision avoidance system on board the aircraft.

The Design, Development and Testing of Complex Avionics Systems: Conference Proceedings Held at the Avionics Panel Symposium in Las Vegas, Nevada on 27 April-1 May 1987

DTIC Science & Technology

1987-12-01

Normally, the system is decomposed into manageable parts with accurately defined interfaces. By rigidly controlling this process, aerospace companies have...Reference A CHANGE IN SYSTEM DESIGN EMPHASIS: FROM MACHINE TO MAN by M.L.Metersky and J.L.Ryder 16 SESSION I1 - MANAGING THE FUl URE SYSTEM DESIGN...PROCESS MANAGING ADVANCED AVIONIC SYSTEM DESIGN by P.Simons 17 ERGONOMIE PSYCHOSENSORIELLE DES COCKPITS, INTERET DES SYSTEMES INFORMATIQUES INTELLIGENTS

Space Shuttle Program Primary Avionics Software System (PASS) Success Legacy - Quality and Reliability Date

NASA Technical Reports Server (NTRS)

Orr, James K.; Peltier, Daryl

2010-01-01

Thsi slide presentation reviews the avionics software system on board the space shuttle, with particular emphasis on the quality and reliability. The Primary Avionics Software System (PASS) provides automatic and fly-by-wire control of critical shuttle systems which executes in redundant computers. Charts given show the number of space shuttle flights vs time, PASS's development history, and other charts that point to the reliability of the system's development. The reliability of the system is also compared to predicted reliability.

Migrating To The Cloud: Preparing The USMC CDET For MCEITS

DTIC Science & Technology

2016-03-01

Service SAAR System Authorization Access Request SaaS Software as a... Service (IaaS), Platform as a Service (PaaS), Software as a Service ( SaaS ), and Data as a Service (DaaS) (Takai, 2012). A closer examination of each...8 3. Software as a Service NIST described SaaS as a model of cloud computing where the service provider offers its customers fee-based access

Portable Automated Test Station: Using Engineering-Design Partnerships to Replace Obsolete Test Systems

DTIC Science & Technology

2015-04-01

troubleshooting avionics system faults while the aircraft is on the ground. The core component of the PATS-30, the ruggedized laptop, is no longer sustainable...as well as trouble shooting avionics system faults while the aircraft is on the ground. The PATS-70 utilizes up-to-date, sustainable technology for...Operational Flight Program (OFP) software loading and diagnostic avionics system testing and includes additional TPSs to enhance its capability

Rapid and large-scale implementation of HCV treatment advances in France, 2007-2015.

PubMed

Brouard, Cécile; Boussac-Zarebska, Marjorie; Silvain, Christine; Durand, Julien; de Lédinghen, Victor; Pillonel, Josiane; Delarocque-Astagneau, Elisabeth

2017-12-20

The last decade was marked by major advances in HCV treatment with the introduction of first wave protease inhibitors (1st-wave PIs, telaprevir or boceprevir) in 2011 and second direct-acting antivirals (2nd-wave DAAs) in 2014, that followed low effective pegylated interferon α / ribavirin bitherapy. We estimated the number of patients initiating HCV treatment in France between 2007 and 2015 according to the type of therapy, described their demographical characteristics, and estimated how many were cured with 2nd-wave DAAs in 2014-2015. Individual data from the national health insurance information system were analysed. HCV treatment initiation was defined as a drug reimbursement in the absence of any reimbursement for the same drug in the previous six weeks. Between 2007 and 2015, 72,277 patients initiated at least one HCV treatment. The annual number of patients initiating treatment decreased from 2007 (~13,300) to 2010 (~10,000). It then increased with the introduction of 1st-wave PIs (~12,500 in 2012), before decreasing again in 2013 (~8400). A marked increase followed upon the approval of 2nd-wave DAAs in 2014 (~11,600). Approximately, 8700 and 14,700 patients initiated 2nd-wave DAAs in 2014 and 2015, respectively, corresponding to an estimated 20,300 cured patients in 2014-2015. Patients initiating HCV treatment were mostly male (~65% throughout the 9-year period). Women were older than men (mean age: 55.0 vs. 48.9). Increasing age was associated with more advanced treatment. Among patients initiating 2nd-wave DAAs, the proportions of those under 40 and over 79 years old increased between 2014 and 2015, whereas the proportion of those previously treated for HCV 2007 onwards declined. Successive advances in HCV treatment have been rapidly and widely implemented in France. With the announcement of universal access to DAAs in mid-2016 and price reductions, access to 2nd-wave DAAs is expected to expand even more.

Hepatitis C virus protease inhibitor-resistance mutations: our experience and review.

PubMed

Wu, Shuang; Kanda, Tatsuo; Nakamoto, Shingo; Imazeki, Fumio; Yokosuka, Osamu

2013-12-21

Direct-acting antiviral agents (DAAs) for hepatitis C virus (HCV) infection are one of the major advances in its medical treatment. The HCV protease inhibitors boceprevir and telaprevir were the first approved DAAs in the United States, Europe, and Japan. When combined with peginterferon plus ribavirin, these agents increase sustained virologic response rates to 70%-80% in treatment-naïve patients and previous-treatment relapsers with chronic HCV genotype 1 infection. Without peginterferon plus ribavirin, DAA mono-therapies increased DAA-resistance mutations. Several new DAAs for HCV are now in clinical development and are likely to be approved in the near future. However, it has been reported that the use of these drugs also led to the emergence of DAA-resistance mutations in certain cases. Furthermore, these mutations exhibit cross-resistance to multiple drugs. The prevalence of DAA-resistance mutations in HCV-infected patients who were not treated with DAAs is unknown, and it is as yet uncertain whether such variants are sensitive to DAAs. We performed a population sequence analysis to assess the frequency of such variants in the sera of HCV genotype 1-infected patients not treated with HCV protease inhibitors. Here, we reviewed the literature on resistance variants of HCV protease inhibitors in treatment naïve patients with chronic HCV genotype 1, as well as our experience.

HH-65A Dolphin digital integrated avionics

NASA Technical Reports Server (NTRS)

Huntoon, R. B.

1984-01-01

Communication, navigation, flight control, and search sensor management are avionics functions which constitute every Search and Rescue (SAR) operation. Routine cockpit duties monopolize crew attention during SAR operations and thus impair crew effectiveness. The United States Coast Guard challenged industry to build an avionics system that automates routine tasks and frees the crew to focus on the mission tasks. The HH-64A SAR avionics systems of communication, navigation, search sensors, and flight control have existed independently. On the SRR helicopter, the flight management system (FMS) was introduced. H coordinates or integrates these functions. The pilot interacts with the FMS rather than the individual subsystems, using simple, straightforward procedures to address distinct mission tasks and the flight management system, in turn, orchestrates integrated system response.

Advanced Avionics Architecture and Technology Review. Executive Summary and Volume 1, Avionics Technology. Volume 2. Avionics Systems Engineering

DTIC Science & Technology

1993-08-06

JIAWG core avionics are described in the section below. The JIAWO architecture standard (187-01) describes an open. system architeture which provides...0.35 microns (pRm). Present technology is in the 0.8 npm to 0.5 pm range for aggressive producers. Since the area of a die is approximately proportional ...analog (D/A) converters. The I A/D converter is a device or circuit that examines an analog voltage or current and converts it to a proportional binary

Space Generic Open Avionics Architecture (SGOAA): Overview

NASA Technical Reports Server (NTRS)

Wray, Richard B.; Stovall, John R.

1992-01-01

A space generic open avionics architecture created for NASA is described. It will serve as the basis for entities in spacecraft core avionics, capable of being tailored by NASA for future space program avionics ranging from small vehicles such as Moon ascent/descent vehicles to large ones such as Mars transfer vehicles or orbiting stations. The standard consists of: (1) a system architecture; (2) a generic processing hardware architecture; (3) a six class architecture interface model; (4) a system services functional subsystem architectural model; and (5) an operations control functional subsystem architectural model.

Automatic design of IMA systems

NASA Astrophysics Data System (ADS)

Salomon, U.; Reichel, R.

During the last years, the integrated modular avionics (IMA) design philosophy became widely established at aircraft manufacturers, giving rise to a series of new design challenges, most notably the allocation of avionics functions to the various IMA components and the placement of this equipment in the aircraft. This paper presents a modelling approach for avionics that allows automation of some steps of the design process by applying an optimisation algorithm which searches for system configurations that fulfil the safety requirements and have low costs. The algorithm was implemented as a quite sophisticated software prototype, therefore we will also present detailed results of its application to actual avionics systems.

AFTI/F16 Automated Maneuvering Attack System Test Reports/Special Technologies and Outlook.

DTIC Science & Technology

1986-07-11

Multiplex Data Bus A-A Air-To-Air A-S Air-to-Surface AFTI Advanced Fighter Technology Integration SYSTEM DESIGN AGL Above-Ground-Level AMAS Automated...Maneuvering Attack System Design requirements for the AFTI/F-16 are driven AMUX Avionics Multiplex Data Bus by realistic air combat scenarios and are...the avionics subsystem IFIM and avionics systems are single-thread, much of the sensed various flight control sensors. Additionally, along with data

Avionic Architecture for Model Predictive Control Application in Mars Sample & Return Rendezvous Scenario

NASA Astrophysics Data System (ADS)

Saponara, M.; Tramutola, A.; Creten, P.; Hardy, J.; Philippe, C.

2013-08-01

Optimization-based control techniques such as Model Predictive Control (MPC) are considered extremely attractive for space rendezvous, proximity operations and capture applications that require high level of autonomy, optimal path planning and dynamic safety margins. Such control techniques require high-performance computational needs for solving large optimization problems. The development and implementation in a flight representative avionic architecture of a MPC based Guidance, Navigation and Control system has been investigated in the ESA R&T study “On-line Reconfiguration Control System and Avionics Architecture” (ORCSAT) of the Aurora programme. The paper presents the baseline HW and SW avionic architectures, and verification test results obtained with a customised RASTA spacecraft avionics development platform from Aeroflex Gaisler.

Space shuttle avionics system

NASA Technical Reports Server (NTRS)

Hanaway, John F.; Moorehead, Robert W.

1989-01-01

The Space Shuttle avionics system, which was conceived in the early 1970's and became operational in the 1980's represents a significant advancement of avionics system technology in the areas of systems and redundacy management, digital data base technology, flight software, flight control integration, digital fly-by-wire technology, crew display interface, and operational concepts. The origins and the evolution of the system are traced; the requirements, the constraints, and other factors which led to the final configuration are outlined; and the functional operation of the system is described. An overall system block diagram is included.

Hepatitis C Virus Cell-Cell Transmission and Resistance to Direct-Acting Antiviral Agents

PubMed Central

Heydmann, Laura; Barth, Heidi; Soulier, Eric; Habersetzer, François; Doffoël, Michel; Bukh, Jens; Patel, Arvind H.; Zeisel, Mirjam B.; Baumert, Thomas F.

2014-01-01

Hepatitis C virus (HCV) is transmitted between hepatocytes via classical cell entry but also uses direct cell-cell transfer to infect neighboring hepatocytes. Viral cell-cell transmission has been shown to play an important role in viral persistence allowing evasion from neutralizing antibodies. In contrast, the role of HCV cell-cell transmission for antiviral resistance is unknown. Aiming to address this question we investigated the phenotype of HCV strains exhibiting resistance to direct-acting antivirals (DAAs) in state-of-the-art model systems for cell-cell transmission and spread. Using HCV genotype 2 as a model virus, we show that cell-cell transmission is the main route of viral spread of DAA-resistant HCV. Cell-cell transmission of DAA-resistant viruses results in viral persistence and thus hampers viral eradication. We also show that blocking cell-cell transmission using host-targeting entry inhibitors (HTEIs) was highly effective in inhibiting viral dissemination of resistant genotype 2 viruses. Combining HTEIs with DAAs prevented antiviral resistance and led to rapid elimination of the virus in cell culture model. In conclusion, our work provides evidence that cell-cell transmission plays an important role in dissemination and maintenance of resistant variants in cell culture models. Blocking virus cell-cell transmission prevents emergence of drug resistance in persistent viral infection including resistance to HCV DAAs. PMID:24830295

The single event upset environment for avionics at high latitude

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sims, A.J.; Dyer, C.S.; Peerless, C.L.

1994-12-01

Modern avionic systems for civil and military applications are becoming increasingly reliant upon embedded microprocessors and associated memory devices. The phenomenon of single event upset (SEU) is well known in space systems and designers have generally been careful to use SEU tolerant devices or to implement error detection and correction (EDAC) techniques where appropriate. In the past, avionics designers have had no reason to consider SEU effects but is clear that the more prevalent use of memory devices combined with increasing levels of IC integration will make SEU mitigation an important design consideration for future avionic systems. To this end,more » it is necessary to work towards producing models of the avionics SEU environment which will permit system designers to choose components and EDAC techniques which are based on predictions of SEU rates correct to much better than an order of magnitude. Measurements of the high latitude SEU environment at avionics altitude have been made on board a commercial airliner. Results are compared with models of primary and secondary cosmic rays and atmospheric neutrons. Ground based SEU tests of static RAMs are used to predict rates in flight.« less

Wireless avionics for space applications of fundamental physics

NASA Astrophysics Data System (ADS)

Wang, Linna; Zeng, Guiming

2016-07-01

Fundamental physics (FP) research in space relies on a strong support of spacecraft. New types of spacecraft including reusable launch vehicles, reentry space vehicles, long-term on-orbit spacecraft or other new type of spacecraft will pave the way for FP missions. In order to test FP theories in space, flight conditions have to be controlled to a very high precision, data collection and handling abilities have to be improved, real-time and reliable communications in critical environments are needed. These challenge the existing avionics of spacecraft. Avionics consists of guidance, navigation & control, TT&C, the vehicle management, etc. Wireless avionics is one of the enabling technologies to address the challenges. Reasons are expatiated of why it is of great advantage. This paper analyses the demands for wireless avionics by reviewing the FP missions and on-board wireless systems worldwide. Main types of wireless communication are presented. Preliminary system structure of wireless avionics are given. The characteristics of wireless network protocols and wireless sensors are introduced. Key technologies and design considerations for wireless avionics in space applications are discussed.

Advanced Information Processing System (AIPS)-based fault tolerant avionics architecture for launch vehicles

NASA Technical Reports Server (NTRS)

Lala, Jaynarayan H.; Harper, Richard E.; Jaskowiak, Kenneth R.; Rosch, Gene; Alger, Linda S.; Schor, Andrei L.

1990-01-01

An avionics architecture for the advanced launch system (ALS) that uses validated hardware and software building blocks developed under the advanced information processing system program is presented. The AIPS for ALS architecture defined is preliminary, and reliability requirements can be met by the AIPS hardware and software building blocks that are built using the state-of-the-art technology available in the 1992-93 time frame. The level of detail in the architecture definition reflects the level of detail available in the ALS requirements. As the avionics requirements are refined, the architecture can also be refined and defined in greater detail with the help of analysis and simulation tools. A useful methodology is demonstrated for investigating the impact of the avionics suite to the recurring cost of the ALS. It is shown that allowing the vehicle to launch with selected detected failures can potentially reduce the recurring launch costs. A comparative analysis shows that validated fault-tolerant avionics built out of Class B parts can result in lower life-cycle-cost in comparison to simplex avionics built out of Class S parts or other redundant architectures.

The New Era of Interferon-Free Treatment of Chronic Hepatitis C

PubMed Central

Solbach, Philipp; Wedemeyer, Heiner

2015-01-01

Summary Background Within the development and approval of several new direct-acting antivirals (DAA) against hepatitis C virus (HCV), a new era of hepatitis C therapy has begun. Even more treatment options are likely to become available during the next 1-2 years. Methods A summary of the current phase II and III trials investigating DAA and a review of the recent HCV guidelines was conducted. Results With the development of new potent DAA and the approval of different DAA combinations, cure rates of HCV infection of >90% are achievable for almost all HCV genotypes and stages of liver disease. Currently available DAA target different steps in the HCV replication cycle, in particular the NS3/4A protease, the NS5B polymerase, and the NS5A replication complex. Treatment duration varies between 8 and 24 weeks depending on the stage of fibrosis, prior treatment, HCV viral load, and HCV genotype. Ribavirin is required only for some treatment regimens and may be particularly beneficial in patients with cirrhosis. DAA resistance influences treatment outcome only marginally; thus, drug resistance testing is not routinely recommended before treatment. In the case of treatment failure, however, resistance testing should be performed before re-treatment with other DAA is initiated. Conclusion With the new, almost side effect-free DAA treatment options chronic HCV infection became a curable disease. The clinical benefit of DAA combination therapies in patients with advanced cirrhosis and the effects on incidence rates of hepatocellular carcinoma remain to be determined. PMID:26557839

The implementation of fail-operative functions in integrated digital avionics systems

NASA Technical Reports Server (NTRS)

Osoer, S. S.

1976-01-01

System architectures which incorporate fail operative flight guidance functions within a total integrated avionics complex are described. It is shown that the mixture of flight critical and nonflight critical functions within a common computer complex is an efficient solution to the integration of navigation, guidance, flight control, display, and flight management. Interfacing subsystems retain autonomous capability to avoid vulnerability to total avionics system shutdown as a result of only a few failures.

Functional design to support CDTI/DABS flight experiments

NASA Technical Reports Server (NTRS)

Goka, T.

1982-01-01

The objectives of this project are to: (1) provide a generalized functional design of CDTI avionics using the FAA developd DABS/ATARS ground system as the 'traffic sensor', (2) specify software modifications and/or additions to the existing DABS/ATARS ground system to support CDTI avionics, (3) assess the existing avionics of a NASA research aircraft in terms of CDTI applications, and (4) apply the generalized functional design to provide research flight experiment capability. DABS Data Link Formats are first specified for CDTI flight experiments. The set of CDTI/DABS Format specifications becomes a vehicle to coordinate the CDTI avionics and ground system designs, and hence, to develop overall system requirements. The report is the first iteration of a system design and development effort to support eventual CDTI flight test experiments.

Definition of avionics concepts for a heavy lift cargo vehicle. Volume 1: Executive summary

NASA Technical Reports Server (NTRS)

1989-01-01

A cost effective, multiuser simulation, test, and demonstration facility to support the development of avionics systems for future space vehicles is examined. The technology needs and requirements of future Heavy Lift Cargo Vehicles (HLCVs) are analyzed and serve as the basis for sizing of the avionics facility, although the lab is not limited in use to support of HLCVs. Volume 1 provides a summary of the vehicle avionics trade studies, the avionics lab objectives, a summary of the lab's functional requirements and design, physical facility considerations, and cost estimates.

Avionics test bed development plan

NASA Technical Reports Server (NTRS)

Harris, L. H.; Parks, J. M.; Murdock, C. R.

1981-01-01

A development plan for a proposed avionics test bed facility for the early investigation and evaluation of new concepts for the control of large space structures, orbiter attached flex body experiments, and orbiter enhancements is presented. A distributed data processing facility that utilizes the current laboratory resources for the test bed development is outlined. Future studies required for implementation, the management system for project control, and the baseline system configuration are defined. A background analysis of the specific hardware system for the preliminary baseline avionics test bed system is included.

Advanced Launch System Multi-Path Redundant Avionics Architecture Analysis and Characterization

NASA Technical Reports Server (NTRS)

Baker, Robert L.

1993-01-01

The objective of the Multi-Path Redundant Avionics Suite (MPRAS) program is the development of a set of avionic architectural modules which will be applicable to the family of launch vehicles required to support the Advanced Launch System (ALS). To enable ALS cost/performance requirements to be met, the MPRAS must support autonomy, maintenance, and testability capabilities which exceed those present in conventional launch vehicles. The multi-path redundant or fault tolerance characteristics of the MPRAS are necessary to offset a reduction in avionics reliability due to the increased complexity needed to support these new cost reduction and performance capabilities and to meet avionics reliability requirements which will provide cost-effective reductions in overall ALS recurring costs. A complex, real-time distributed computing system is needed to meet the ALS avionics system requirements. General Dynamics, Boeing Aerospace, and C.S. Draper Laboratory have proposed system architectures as candidates for the ALS MPRAS. The purpose of this document is to report the results of independent performance and reliability characterization and assessment analyses of each proposed candidate architecture and qualitative assessments of testability, maintainability, and fault tolerance mechanisms. These independent analyses were conducted as part of the MPRAS Part 2 program and were carried under NASA Langley Research Contract NAS1-17964, Task Assignment 28.

Crew Exploration Vehicle (CEV) Avionics Integration Laboratory (CAIL) Independent Analysis

NASA Technical Reports Server (NTRS)

Davis, Mitchell L.; Aguilar, Michael L.; Mora, Victor D.; Regenie, Victoria A.; Ritz, William F.

2009-01-01

Two approaches were compared to the Crew Exploration Vehicle (CEV) Avionics Integration Laboratory (CAIL) approach: the Flat-Sat and Shuttle Avionics Integration Laboratory (SAIL). The Flat-Sat and CAIL/SAIL approaches are two different tools designed to mitigate different risks. Flat-Sat approach is designed to develop a mission concept into a flight avionics system and associated ground controller. The SAIL approach is designed to aid in the flight readiness verification of the flight avionics system. The approaches are complimentary in addressing both the system development risks and mission verification risks. The following NESC team findings were identified: The CAIL assumption is that the flight subsystems will be matured for the system level verification; The Flat-Sat and SAIL approaches are two different tools designed to mitigate different risks. The following NESC team recommendation was provided: Define, document, and manage a detailed interface between the design and development (EDL and other integration labs) to the verification laboratory (CAIL).

Assessment of avionics technology in European aerospace organizations

NASA Technical Reports Server (NTRS)

Martinec, D. A.; Baumbick, Robert; Hitt, Ellis; Leondes, Cornelius; Mayton, Monica; Schwind, Joseph; Traybar, Joseph

1992-01-01

This report provides a summary of the observations and recommendations made by a technical panel formed by the National Aeronautics and Space Administration (NASA). The panel, comprising prominent experts in the avionics field, was tasked to visit various organizations in Europe to assess the level of technology planned for use in manufactured civil avionics in the future. The primary purpose of the study was to assess avionics systems planned for implementation or already employed on civil aircraft and to evaluate future research, development, and engineering (RD&E) programs, address avionic systems and aircraft programs. The ultimate goal is to ensure that the technology addressed by NASa programs is commensurate with the needs of the aerospace industry at an international level. The panel focused on specific technologies, including guidance and control systems, advanced cockpit displays, sensors and data networks, and fly-by-wire/fly-by-light systems. However, discussions the panel had with the European organizations were not limited to these topics.

Alternate avionics system study and phase B extension

NASA Technical Reports Server (NTRS)

1971-01-01

Results of alternate avionics system studies for the space shuttle are presented that reduce the cost of vehicle avionics without incurring major off-setting costs on the ground. A comprehensive summary is provided of all configurations defined since the completion of the basic Phase B contract and a complete description of the optimized avionics baseline is given. In the new baseline, inflight redundancy management is performed onboard without ground support; utilization of off-the-shelf hardware reduces the cost figure substantially less than for the Phase B baseline. The only functional capability sacrificed in the new approach is automatic landing.

Spacelab system analysis: A study of the Marshall Avionics System Testbed (MAST)

NASA Astrophysics Data System (ADS)

Ingels, Frank M.; Owens, John K.; Daniel, Steven P.; Ahmad, F.; Couvillion, W.

1988-09-01

An analysis of the Marshall Avionics Systems Testbed (MAST) communications requirements is presented. The average offered load for typical nodes is estimated. Suitable local area networks are determined.

Spacelab system analysis: A study of the Marshall Avionics System Testbed (MAST)

NASA Technical Reports Server (NTRS)

Ingels, Frank M.; Owens, John K.; Daniel, Steven P.; Ahmad, F.; Couvillion, W.

1988-01-01

An analysis of the Marshall Avionics Systems Testbed (MAST) communications requirements is presented. The average offered load for typical nodes is estimated. Suitable local area networks are determined.

Integrated Test and Evaluation (ITE) Flight Test Series 4

NASA Technical Reports Server (NTRS)

Marston, Michael

2016-01-01

The integrated Flight Test 4 (FT4) will gather data for the UAS researchers Sense and Avoid systems (referred to as Detect and Avoid in the RTCA SC 228 ToR) algorithms and pilot displays for candidate UAS systems in a relevant environment. The technical goals of FT4 are to: 1) perform end-to-end traffic encounter test of pilot guidance generated by DAA algorithms; 2) collect data to inform the initial Minimum Operational Performance Standards (MOPS) for Detect and Avoid systems. FT4 objectives and test infrastructure builds from previous UAS project simulations and flight tests. NASA Ames (ARC), NASA Armstrong (AFRC), and NASA Langley (LaRC) Research Centers will share responsibility for conducting the tests, each providing a test lab and critical functionality. UAS-NAS project support and participation on the 2014 flight test of ACAS Xu and DAA Self Separation (SS) significantly contributed to building up infrastructure and procedures for FT3 as well. The DAA Scripted flight test (FT4) will be conducted out of NASA Armstrong over an eight-week period beginning in April 2016.

Definition, analysis and development of an optical data distribution network for integrated avionics and control systems. Part 2: Component development and system integration

NASA Technical Reports Server (NTRS)

Yen, H. W.; Morrison, R. J.

1984-01-01

Fiber optic transmission is emerging as an attractive concept in data distribution onboard civil aircraft. Development of an Optical Data Distribution Network for Integrated Avionics and Control Systems for commercial aircraft will provide a data distribution network that gives freedom from EMI-RFI and ground loop problems, eliminates crosstalk and short circuits, provides protection and immunity from lightning induced transients and give a large bandwidth data transmission capability. In addition there is a potential for significantly reducing the weight and increasing the reliability over conventional data distribution networks. Wavelength Division Multiplexing (WDM) is a candidate method for data communication between the various avionic subsystems. With WDM all systems could conceptually communicate with each other without time sharing and requiring complicated coding schemes for each computer and subsystem to recognize a message. However, the state of the art of optical technology limits the application of fiber optics in advanced integrated avionics and control systems. Therefore, it is necessary to address the architecture for a fiber optics data distribution system for integrated avionics and control systems as well as develop prototype components and systems.

Advanced software integration: The case for ITV facilities

NASA Technical Reports Server (NTRS)

Garman, John R.

1990-01-01

The array of technologies and methodologies involved in the development and integration of avionics software has moved almost as rapidly as computer technology itself. Future avionics systems involve major advances and risks in the following areas: (1) Complexity; (2) Connectivity; (3) Security; (4) Duration; and (5) Software engineering. From an architectural standpoint, the systems will be much more distributed, involve session-based user interfaces, and have the layered architectures typified in the layers of abstraction concepts popular in networking. Typified in the NASA Space Station Freedom will be the highly distributed nature of software development itself. Systems composed of independent components developed in parallel must be bound by rigid standards and interfaces, the clean requirements and specifications. Avionics software provides a challenge in that it can not be flight tested until the first time it literally flies. It is the binding of requirements for such an integration environment into the advances and risks of future avionics systems that form the basis of the presented concept and the basic Integration, Test, and Verification concept within the development and integration life cycle of Space Station Mission and Avionics systems.

Fiber optic interconnect and optoelectronic packaging challenges for future generation avionics

NASA Astrophysics Data System (ADS)

Beranek, Mark W.

2007-02-01

Forecasting avionics industry fiber optic interconnect and optoelectronic packaging challenges that lie ahead first requires an assumption that military avionics architectures will evolve from today's centralized/unified concept based on gigabit laser, optical-to-electrical-to-optical switching and optical backplane technology, to a future federated/distributed or centralized/unified concept based on gigabit tunable laser, electro-optical switch and add-drop wavelength division multiplexing (WDM) technology. The requirement to incorporate avionics optical built-in test (BIT) in military avionics fiber optic systems is also assumed to be correct. Taking these assumptions further indicates that future avionics systems engineering will use WDM technology combined with photonic circuit integration and advanced packaging to form the technical basis of the next generation military avionics onboard local area network (LAN). Following this theme, fiber optic cable plants will evolve from today's multimode interconnect solution to a single mode interconnect solution that is highly installable, maintainable, reliable and supportable. Ultimately optical BIT for fiber optic fault detection and isolation will be incorporated as an integral part of a total WDM-based avionics LAN solution. Cost-efficient single mode active and passive photonic component integration and packaging integration is needed to enable reliable operation in the harsh military avionics application environment. Rugged multimode fiber-based transmitters and receivers (transceivers) with in-package optical BIT capability are also needed to enable fully BIT capable single-wavelength fiber optic links on both legacy and future aerospace platforms.

Definition of avionics concepts for a heavy lift cargo vehicle, volume 2

NASA Technical Reports Server (NTRS)

1989-01-01

A cost effective, multiuser simulation, test, and demonstration facility to support the development of avionics systems for future space vehicles is defined. The technology needs and requirements of future Heavy Lift Cargo Vehicles (HLCVs) are analyzed and serve as the basis for sizing of the avionics facility although the lab is not limited in use to support of HLCVs. Volume 2 is the technical volume and provides the results of the vehicle avionics trade studies, the avionics lab objectives, the lab's functional requirements and design, physical facility considerations, and a summary cost estimate.

Organization and use of a Software/Hardware Avionics Research Program (SHARP)

NASA Technical Reports Server (NTRS)

Karmarkar, J. S.; Kareemi, M. N.

1975-01-01

The organization and use is described of the software/hardware avionics research program (SHARP) developed to duplicate the automatic portion of the STOLAND simulator system, on a general-purpose computer system (i.e., IBM 360). The program's uses are: (1) to conduct comparative evaluation studies of current and proposed airborne and ground system concepts via single run or Monte Carlo simulation techniques, and (2) to provide a software tool for efficient algorithm evaluation and development for the STOLAND avionics computer.

Unmanned Aircraft Systems Human-in-the-Loop Controller and Pilot Acceptability Study: Collision Avoidance, Self-Separation, and Alerting Times (CASSAT)

NASA Technical Reports Server (NTRS)

Comstock, James R., Jr.; Ghatas, Rania W.; Vincent, Michael J.; Consiglio, Maria C.; Munoz, Cesar; Chamberlain, James P.; Volk, Paul; Arthur, Keith E.

2016-01-01

The Federal Aviation Administration (FAA) has been mandated by the Congressional funding bill of 2012 to open the National Airspace System (NAS) to Unmanned Aircraft Systems (UAS). With the growing use of unmanned systems, NASA has established a multi-center "UAS Integration in the NAS" Project, in collaboration with the FAA and industry, and is guiding its research efforts to look at and examine crucial safety concerns regarding the integration of UAS into the NAS. Key research efforts are addressing requirements for detect-and-avoid (DAA), self-separation (SS), and collision avoidance (CA) technologies. In one of a series of human-in-the-loop experiments, NASA Langley Research Center set up a study known as Collision Avoidance, Self-Separation, and Alerting Times (CASSAT). The first phase assessed active air traffic controller interactions with DAA systems and the second phase examined reactions to the DAA system and displays by UAS Pilots at a simulated ground control station (GCS). Analyses of the test results from Phase I and Phase II are presented in this paper. Results from the CASSAT study and previous human-in-the-loop experiments will play a crucial role in the FAA's establishment of rules, regulations, and procedures to safely, efficiently, and effectively integrate UAS into the NAS.

Space Generic Open Avionics Architecture (SGOAA) standard specification

NASA Technical Reports Server (NTRS)

Wray, Richard B.; Stovall, John R.

1993-01-01

The purpose of this standard is to provide an umbrella set of requirements for applying the generic architecture interface model to the design of a specific avionics hardware/software system. This standard defines a generic set of system interface points to facilitate identification of critical interfaces and establishes the requirements for applying appropriate low level detailed implementation standards to those interface points. The generic core avionics system and processing architecture models provided herein are robustly tailorable to specific system applications and provide a platform upon which the interface model is to be applied.

Comparison of custom versus COTS AMLCDs for military and avionic applications

NASA Astrophysics Data System (ADS)

Angelo, Van

1997-07-01

AMLCD's are currently the flat panel technology of choice for military systems and civil transport avionic applications, both new and retrofit. Historically, military and avionic displays have ben custom designed and have generally been specific to each application. Two recent developments have given display system designers a choice between a custom military/avionic solution or a ruggedized commercial off-the-shelf (COTS) implementation. The first development is the widespread availability of various consumer and automotive AMLCD panels at low prices. The second is the change in the policy of defense departments, notably the US Department of Defense, to procure COTS components instead of developing custom solutions. This paper assesses and analyzes the key differences in characteristics, performance and logistical supportability of military and avionic AMLCD's and presents the tradeoffs involved in making the optimum choice between custom and COTS.

Cost-effectiveness of hepatitis C treatment using generic direct-acting antivirals available in India

PubMed Central

Aggarwal, Rakesh; Chen, Qiushi; Goel, Amit; Seguy, Nicole; Pendse, Razia; Ayer, Turgay

2017-01-01

Background & aims Availability of directly-acting antivirals (DAAs) has changed the treatment landscape of hepatitis C virus (HCV) infection. The high price of DAAs has restricted their use in several countries. However, in some countries such as India, generic DAAs are available at much cheaper price. This study examined whether generic DAAs could be cost-saving and how long it would take for the treatment to become cost-saving/effective. Methods A previously-validated, mathematical model was adapted to the HCV-infected population in India to compare the outcomes of no treatment versus treatment with DAAs. Model parameters were estimated from published studies. Cost-effectiveness of HCV treatment using available DAAs was calculated, using a payer’s perspective. We estimated quality-adjusted life years (QALYs), disability-adjusted life years (DALYs), total costs, and incremental cost-effectiveness ratio of DAAs versus no treatment. One-way and probabilistic sensitivity analyses were conducted. Results Compared with no treatment, the use of generic DAAs in Indian HCV patients would increase the life expectancy by 8.02 years, increase QALYs by 3.89, avert 19.07 DALYs, and reduce the lifetime healthcare costs by $1,309 per-person treated. Treatment became cost-effective within 2 years, and cost-saving within 10 years of its initiation overall and within 5 years in persons with cirrhosis. Treating 10,000 HCV-infected persons could prevent 3400–3850 decompensated cirrhosis, 1800–2500 HCC, and 4000–4550 liver-related deaths. The results were sensitive to the costs of DAAs, pre- and post-treatment diagnostic tests and management of cirrhosis, and quality of life after sustained virologic response. Conclusions Treatment with generic DAAs available in India will improve patient outcomes, provide a good value for money within 2 years, and be ultimately cost-saving. Therefore, in this and similar settings, HCV treatment should be a priority from a public health as well an economic perspective. PMID:28520728

Cost-effectiveness of hepatitis C treatment using generic direct-acting antivirals available in India.

PubMed

Aggarwal, Rakesh; Chen, Qiushi; Goel, Amit; Seguy, Nicole; Pendse, Razia; Ayer, Turgay; Chhatwal, Jagpreet

2017-01-01

Availability of directly-acting antivirals (DAAs) has changed the treatment landscape of hepatitis C virus (HCV) infection. The high price of DAAs has restricted their use in several countries. However, in some countries such as India, generic DAAs are available at much cheaper price. This study examined whether generic DAAs could be cost-saving and how long it would take for the treatment to become cost-saving/effective. A previously-validated, mathematical model was adapted to the HCV-infected population in India to compare the outcomes of no treatment versus treatment with DAAs. Model parameters were estimated from published studies. Cost-effectiveness of HCV treatment using available DAAs was calculated, using a payer's perspective. We estimated quality-adjusted life years (QALYs), disability-adjusted life years (DALYs), total costs, and incremental cost-effectiveness ratio of DAAs versus no treatment. One-way and probabilistic sensitivity analyses were conducted. Compared with no treatment, the use of generic DAAs in Indian HCV patients would increase the life expectancy by 8.02 years, increase QALYs by 3.89, avert 19.07 DALYs, and reduce the lifetime healthcare costs by $1,309 per-person treated. Treatment became cost-effective within 2 years, and cost-saving within 10 years of its initiation overall and within 5 years in persons with cirrhosis. Treating 10,000 HCV-infected persons could prevent 3400-3850 decompensated cirrhosis, 1800-2500 HCC, and 4000-4550 liver-related deaths. The results were sensitive to the costs of DAAs, pre- and post-treatment diagnostic tests and management of cirrhosis, and quality of life after sustained virologic response. Treatment with generic DAAs available in India will improve patient outcomes, provide a good value for money within 2 years, and be ultimately cost-saving. Therefore, in this and similar settings, HCV treatment should be a priority from a public health as well an economic perspective.

Effects of lead and cadmium nitrate on biomass and substrate utilization pattern of soil microbial communities.

PubMed

Muhammad, Akmal; Xu, Jianming; Li, Zhaojun; Wang, Haizhen; Yao, Huaiying

2005-07-01

A study was conducted to evaluate the effects of different concentrations of lead (Pb) and cadmium (Cd) applied as their nitrates on soil microbial biomass carbon (C(mic)) and nitrogen (N(mic)), and substrate utilization pattern of soil microbial communities. The C(mic) and N(mic) contents were determined at 0, 14, 28, 42 and 56 days after heavy metal application (DAA). The results showed a significant decline in the C(mic) for all Pb and Cd amended soils from the start to 28 DAA. From 28 to 56 DAA, C(mic) contents changed non-significantly for all other treatments except for 600 mgkg(-1) Pb and 100 mgkg(-1) Cd in which it declined significantly from 42 to 56 DAA. The N(mic) contents also decreased significantly from start to 28 DAA for all other Pb and Cd treatments except for 200 mgkg(-1) Pb which did not show significant difference from the control. Control and 200 mgkg(-1) Pb had significantly lower soil microbial biomass C:N ratio as compared with other Pb treatments from 14 to 42 DAA, however at 56 DAA, only 1000 mgkg(-1) Pb showed significantly higher C:N ratio compared with other treatments. No significant difference in C:N ratio for all Cd treated soils was seen from start to 28 DAA, however from 42 to 56 DAA, 100 mgkg(-1) Pb showed significantly higher C:N ratio compared with other treatments. On 56 DAA, substrate utilization pattern of soil microbial communities was determined by inoculating Biolog ECO plates. The results indicated that Pb and Cd addition inhibited the functional activity of soil microbial communities as indicated by the intensity of average well color development (AWCD) during 168 h of incubation. Multivariate analysis of sole carbon source utilization pattern demonstrated that higher levels of heavy metal application had significantly affected soil microbial community structure.

Stage-Specific Fatty Acid Fluxes Play a Regulatory Role in Glycerolipid Metabolism during Seed Development in Jatropha curcas L.

PubMed

Chaitanya, Bharatula Sri Krishna; Kumar, Sumit; Kaki, Shiva Shanker; Balakrishna, Marrapu; Karuna, Mallampalli Sri Lakshmi; Prasad, Rachapudi Badari Narayana; Sastry, Pidaparty Seshadri; Reddy, Attipalli Ramachandra

2015-12-23

The present study describes the changes in lipid profile as well as fatty acid fluxes during seed development in Jatropha curcas L. Endosperm from 34, 37, and 40 days after anthesis (DAA), incubated with [(14)C]acetate, showed significant synthesis of phosphatidylcholine (PC) at seed maturation. The fatty acid methyl ester profile showed PC from 34 DAA was rich in palmitic acid (16:0), whereas PC from 37 and 40 DAA was rich in oleic acid (18:1n-9). Molecular species analysis of diacylglycerol (DAG) indicated DAG (16:0/18:2n-6) was in abundance at 34 DAA, whereas DAG (18:1n-9/18:2n-6) was significantly high at 40 DAA. Triacylglycerol (TAG) analysis revealed TAG (16:0/18:2n-6/16:0) was abundant at 34 DAA, whereas TAG (18:1n-9/18:2n-6/18:1n-9) formed the majority at 40 DAA. Expression of two types of diacylglycerol acyltransferases varied with seed maturation. These data demonstrate stage-specific distinct pools of PC and DAG synthesis during storage TAG accumulation in Jatropha seed.

In vivo antioxidant activity of deacetylasperulosidic Acid in noni.

PubMed

Ma, De-Lu; Chen, Mai; Su, Chen X; West, Brett J

2013-01-01

Deacetylasperulosidic acid (DAA) is a major phytochemical constituent of Morinda citrifolia (noni) fruit. Noni juice has demonstrated antioxidant activity in vivo and in human trials. To evaluate the role of DAA in this antioxidant activity, Wistar rats were fed 0 (control group), 15, 30, or 60 mg/kg body weight per day for 7 days. Afterwards, serum malondialdehyde concentration and superoxide dismutase and glutathione peroxidase activities were measured and compared among groups. A dose-dependent reduction in malondialdehyde was evident as well as a dose-dependent increase in superoxide dismutase activity. DAA ingestion did not influence serum glutathione peroxidase activity. These results suggest that DAA contributes to the antioxidant activity of noni juice by increasing superoxide dismutase activity. The fact that malondialdehyde concentrations declined with increased DAA dose, despite the lack of glutathione peroxidase-inducing activity, suggests that DAA may also increase catalase activity. It has been previously reported that noni juice increases catalase activity in vivo but additional research is required to confirm the effect of DAA on catalase. Even so, the current findings do explain a possible mechanism of action for the antioxidant properties of noni juice that have been observed in human clinical trials.

In Vivo Antioxidant Activity of Deacetylasperulosidic Acid in Noni

PubMed Central

Ma, De-Lu; Chen, Mai; Su, Chen X.; West, Brett J.

2013-01-01

Deacetylasperulosidic acid (DAA) is a major phytochemical constituent of Morinda citrifolia (noni) fruit. Noni juice has demonstrated antioxidant activity in vivo and in human trials. To evaluate the role of DAA in this antioxidant activity, Wistar rats were fed 0 (control group), 15, 30, or 60 mg/kg body weight per day for 7 days. Afterwards, serum malondialdehyde concentration and superoxide dismutase and glutathione peroxidase activities were measured and compared among groups. A dose-dependent reduction in malondialdehyde was evident as well as a dose-dependent increase in superoxide dismutase activity. DAA ingestion did not influence serum glutathione peroxidase activity. These results suggest that DAA contributes to the antioxidant activity of noni juice by increasing superoxide dismutase activity. The fact that malondialdehyde concentrations declined with increased DAA dose, despite the lack of glutathione peroxidase-inducing activity, suggests that DAA may also increase catalase activity. It has been previously reported that noni juice increases catalase activity in vivo but additional research is required to confirm the effect of DAA on catalase. Even so, the current findings do explain a possible mechanism of action for the antioxidant properties of noni juice that have been observed in human clinical trials. PMID:24371540

Fault tolerant testbed evaluation, phase 1

NASA Technical Reports Server (NTRS)

Caluori, V., Jr.; Newberry, T.

1993-01-01

In recent years, avionics systems development costs have become the driving factor in the development of space systems, military aircraft, and commercial aircraft. A method of reducing avionics development costs is to utilize state-of-the-art software application generator (autocode) tools and methods. The recent maturity of application generator technology has the potential to dramatically reduce development costs by eliminating software development steps that have historically introduced errors and the need for re-work. Application generator tools have been demonstrated to be an effective method for autocoding non-redundant, relatively low-rate input/output (I/O) applications on the Space Station Freedom (SSF) program; however, they have not been demonstrated for fault tolerant, high-rate I/O, flight critical environments. This contract will evaluate the use of application generators in these harsh environments. Using Boeing's quad-redundant avionics system controller as the target system, Space Shuttle Guidance, Navigation, and Control (GN&C) software will be autocoded, tested, and evaluated in the Johnson (Space Center) Avionics Engineering Laboratory (JAEL). The response of the autocoded system will be shown to match the response of the existing Shuttle General Purpose Computers (GPC's), thereby demonstrating the viability of using autocode techniques in the development of future avionics systems.

Increased recurrence rates of hepatocellular carcinoma after DAA therapy in a hepatitis C-infected Egyptian cohort: A comparative analysis.

PubMed

El Kassas, M; Funk, A L; Salaheldin, M; Shimakawa, Y; Eltabbakh, M; Jean, K; El Tahan, A; Sweedy, A T; Afify, S; Youssef, N F; Esmat, G; Fontanet, A

2018-06-01

In Egypt, hepatocellular carcinoma (HCC) is the most common form of cancer and direct-acting antivirals (DAA) are administered on a large scale to patients with chronic HCV infection to reduce the risk. In this unique setting, we aimed to determine the association of DAA exposure with early-phase HCC recurrence in patients with a history of HCV-related liver cancer. This was a prospective cohort study of an HCV-infected population from one Egyptian specialized HCC management centre starting from the time of successful HCC intervention. The incidence rates of HCC recurrence between DAA-exposed and nonexposed patients were compared, starting from date of HCC complete radiological response and censoring after 2 years. DAA exposure was treated as time varying. Two Poisson regressions models were used to control for potential differences in the exposed and nonexposed group; multivariable adjustment and balancing using inverse probability of treatment weighting (IPTW). We included 116 patients: 53 treated with DAAs and 63 not treated with DAAs. There was 37.7% and 25.4% recurrence in each group after a median of 16.0 and 23.0 months of follow-up, respectively. Poisson regression using IPTW demonstrated an association between DAAs and HCC recurrence with an incidence rate ratio of 3.83 (95% CI: 2.02-7.25), which was similar in the multivariable-adjusted model and various sensitivity analyses. These results add important evidence towards the possible role of DAAs in HCC recurrence and stress the need for further mechanistic studies and clinical trials to accurately confirm this role and to identify patient characteristics that may be associated with this event. © 2017 John Wiley & Sons Ltd.

On-treatment decrease of NKG2D correlates to early emergence of clinically evident hepatocellular carcinoma after interferon-free therapy for chronic hepatitis C.

PubMed

Chu, Po-Sung; Nakamoto, Nobuhiro; Taniki, Nobuhito; Ojiro, Keisuke; Amiya, Takeru; Makita, Yuko; Murata, Hiroko; Yamaguchi, Akihiro; Shiba, Shunsuke; Miyake, Rei; Katayama, Tadashi; Ugamura, Aya; Ikura, Akihiko; Takeda, Karin; Ebinuma, Hirotoshi; Saito, Hidetsugu; Kanai, Takanori

2017-01-01

Interferon (IFN)- free direct antiviral agents (DAAs) with rapid HCV eradication might evoke immunological reconstitutions, and some early recurrences of HCC after IFN-free DAAs have been reported. This study aimed to investigate whether natural killer group 2, member D (NKG2D) predicts early emergence of HCC after IFN-free DAAs. We conducted a clinical practice-based observational study of 101 patients infected with genotype 1 HCV who received IFN-free (DAAs), and stratified them into those who did or did not develop early (i.e., during the 6-month surveillance period following treatment.) recurrence or occurrence of clinically evident HCC. We also analyzed the peripheral blood mononuclear cells, both before treatment and at end of treatment (EOT), of 24 of the patients who received IFN-free DAAs, and 16 who received IFN-combined protease inhibitor. We found early emergence of clinically evident HCC after IFN-free DAAs in 12 (12%) patients. Higher pre-treatment NKG2D expression, higher FIB-4 score, previous HCC history and failure to achieve sustained viral response were significant factors correlating to early HCC emergence. After IFN-free DAAs, a rapid decrease of NKG2D at EOT correlated with early HCC emergence in the IFN-free DAA-treated patients, but not in patients treated with the IFN-combined regimen. The decrease of NKG2D until EOT was predictive of early HCC emergence at a cut-off of -52% (AUC = 0.92). On-treatment decrease of NKG2D may be a useful predictor of early emerging HCC in patients treated with IFN-free DAAs.

Cost-Effectiveness of Direct-Acting Anti-viral Treatment in Hepatitis C-infected Liver Transplant Candidates with Compensated Cirrhosis and Hepatocellular Carcinoma

PubMed Central

Salazar, James; Saxena, Varun; Kahn, James G.; Roberts, John P.; Mehta, Neil; Volk, Michael; Lai, Jennifer C.

2016-01-01

Background HCV(+) donors represent an effective strategy to increase liver donor availability to HCV-infected recipients. However, many HCV(+) transplant candidates are now receiving treatment with direct acting anti-virals (DAA) that lower the risk of posttransplant HCV recurrence but could make the patient ineligible for HCV(+) livers. Methods We compared pretransplant DAA treatment versus deferred DAA treatment using a cost-effectiveness decision analysis model to estimate incremental cost-effectiveness ratios (ICERs; cost per quality-adjusted life year [QALY] gained) from the societal perspective across a range of HCV(+) liver availability rates. For practical considerations, the population modelled was restricted to well-compensated HCV(+) cirrhotics listed for liver transplantation with HCC MELD exception points. Results Under base case conditions, the deferred DAA treatment strategy was found to be the “dominant” strategy. That is, it provided superior health outcomes at cost savings compared to the pretransplant DAA treatment strategy. The pretransplant DAA treatment strategy trended towards cost-effectiveness as HCV(+) donor liver availability declined. However, only in 1 scenario that was highly optimized for favorable outcomes in the pretransplant DAA treatment arm (low availability of HCV(+) organs, low cost of DAA treatment, high cost of HCV recurrence) was the ICER associated with HCV DAA treatment before transplant <$150,000/QALY gained. Conclusions Deferring HCV treatment until after liver transplant and maintaining access to the expanded pool of HCV(+) donors appears to be the most cost-effective strategy for well-compensated HCV-infected cirrhotics listed for liver transplantation with HCC, even in geographic areas of relatively low HCV(+) donor availability. PMID:27926593

Cost-Effectiveness of Direct-Acting Antiviral Treatment in Hepatitis C-Infected Liver Transplant Candidates With Compensated Cirrhosis and Hepatocellular Carcinoma.

PubMed

Salazar, James; Saxena, Varun; Kahn, James G; Roberts, John P; Mehta, Neil; Volk, Michael; Lai, Jennifer C

2017-05-01

Hepatitis C virus (HCV)(+) donors represent an effective strategy to increase liver donor availability to HCV-infected recipients. However, many HCV(+) transplant candidates are now receiving treatment with direct-acting anti-viral (DAA) agents that lower the risk of posttransplant HCV recurrence but could make the patient ineligible for HCV(+) livers. We compared pretransplant DAA treatment versus deferred DAA treatment using a cost-effectiveness decision analysis model to estimate incremental cost-effectiveness ratios (cost per quality-adjusted life year gained) from the societal perspective across a range of HCV(+) liver availability rates. For practical considerations, the population modeled was restricted to well-compensated HCV(+) cirrhotics listed for liver transplantation with hepatocellular carcinoma MELD exception points. Under base case conditions, the deferred DAA treatment strategy was found to be the "dominant" strategy. That is, it provided superior health outcomes at cost savings compared to the pretransplant DAA treatment strategy. The pretransplant DAA treatment strategy trended towards cost-effectiveness as HCV(+) donor liver availability declined. However, only in 1 scenario that was highly optimized for favorable outcomes in the pretransplant DAA treatment arm (low availability of HCV(+) organs, low cost of DAA treatment, high cost of HCV recurrence) was the incremental cost-effectiveness ratio associated with HCV DAA treatment before transplant less than US $150 000/quality-adjusted life-year gained. Deferring HCV treatment until after liver transplant and maintaining access to the expanded pool of HCV(+) donors appears to be the most cost-effective strategy for well-compensated HCV-infected cirrhotics listed for liver transplantation with hepatocellular carcinoma, even in geographic areas of relatively low HCV(+) donor availability.

Guidelines for application of fluorescent lamps in high-performance avionic backlight systems

NASA Astrophysics Data System (ADS)

Syroid, Daniel D.

1997-07-01

Fluorescent lamps have proven to be well suited for use in high performance avionic backlight systems as demonstrated by numerous production applications for both commercial and military cockpit displays. Cockpit display applications include: Boeing 777, new 737s, F-15, F-16, F-18, F-22, C- 130, Navy P3, NASA Space Shuttle and many others. Fluorescent lamp based backlights provide high luminance, high lumen efficiency, precision chromaticity and long life for avionic active matrix liquid crystal display applications. Lamps have been produced in many sizes and shapes. Lamp diameters range from 2.6 mm to over 20 mm and lengths for the larger diameter lamps range to over one meter. Highly convoluted serpentine lamp configurations are common as are both hot and cold cathode electrode designs. This paper will review fluorescent lamp operating principles, discuss typical requirements for avionic grade lamps, compare avionic and laptop backlight designs and provide guidelines for the proper application of lamps and performance choices that must be made to attain optimum system performance considering high luminance output, system efficiency, dimming range and cost.

Animal model for hepatitis C virus infection.

PubMed

Tsukiyama-Kohara, Kyoko; Kohara, Michinori

2015-01-01

Hepatitis C virus (HCV) infects more than 170 million people in the world and chronic HCV infection develops into cirrhosis and hepatocellular carcinoma (HCC). Recently, the effective compounds have been approved for HCV treatment, the protease inhibitor and polymerase inhibitor (direct acting antivirals; DAA). DAA-based therapy enabled to cure from HCV infection. However, development of new drug and vaccine is still required because of the generation of HCV escape mutants from DAA, development of HCC after treatment of DAA, and the high cost of DAA. In order to develop new anti-HCV drug and vaccine, animal infection model of HCV is essential. In this manuscript, we would like to introduce the history and the current status of the development of HCV animal infection model.

Investigation of an advanced fault tolerant integrated avionics system

NASA Technical Reports Server (NTRS)

Dunn, W. R.; Cottrell, D.; Flanders, J.; Javornik, A.; Rusovick, M.

1986-01-01

Presented is an advanced, fault-tolerant multiprocessor avionics architecture as could be employed in an advanced rotorcraft such as LHX. The processor structure is designed to interface with existing digital avionics systems and concepts including the Army Digital Avionics System (ADAS) cockpit/display system, navaid and communications suites, integrated sensing suite, and the Advanced Digital Optical Control System (ADOCS). The report defines mission, maintenance and safety-of-flight reliability goals as might be expected for an operational LHX aircraft. Based on use of a modular, compact (16-bit) microprocessor card family, results of a preliminary study examining simplex, dual and standby-sparing architectures is presented. Given the stated constraints, it is shown that the dual architecture is best suited to meet reliability goals with minimum hardware and software overhead. The report presents hardware and software design considerations for realizing the architecture including redundancy management requirements and techniques as well as verification and validation needs and methods.

Next generation space interconnect research and development in space communications

NASA Astrophysics Data System (ADS)

Collier, Charles Patrick

2017-11-01

Interconnect or "bus" is one of the critical technologies in design of spacecraft avionics systems that dictates its architecture and complexity. MIL-STD-1553B has long been used as the avionics backbone technology. As avionics systems become more and more capable and complex, however, limitations of MIL-STD-1553B such as insufficient 1 Mbps bandwidth and separability have forced current avionics architects and designers to use combination of different interconnect technologies in order to meet various requirements: CompactPCI is used for backplane interconnect; LVDS or RS422 is used for low and high-speed direct point-to-point interconnect; and some proprietary interconnect standards are designed for custom interfaces. This results in a very complicated system that consumes significant spacecraft mass and power and requires extensive resources in design, integration and testing of spacecraft systems.

Direct Acting Anti-hepatitis C Virus Drugs: Clinical Pharmacology and Future Direction

PubMed Central

Geddawy, Ayman; Ibrahim, Yasmine F.; Elbahie, Nabil M.; Ibrahim, Mohammad A.

2017-01-01

Abstract Chronic hepatitis C virus (HCV) infection is a leading cause of chronic liver disease. The introduction of direct acting antiviral agents (DAAs) for its treatment represents a major advance in terms of sustained virologic response (SVR) rates and adverse effect profiles. Mechanistically, DAAs inhibit specific HCV non-structural proteins (NS) that are vital for its replication. Boceprevir, telaprevir, simeprevir, asunaprevir, grazoprevir and paritaprevir are NS3/4A inhibitors. Ombitasvir, ledipasvir, daclatasvir, elbasvir and velpatasvir are NS5A inhibitors. Sofosbuvir and dasabuvir are NS5B inhibitors. Currently, a combination of two or more DAAs is the corner stone for the treatment of HCV infection. However, the success of DAA therapy is facing several challenges, including the potential of drug-drug interactions and resistant variance. Moreover, the shortage of relevant clinical pharmacological data and drug interaction regarding DAA is a clinical concern. The present review discusses the clinical pharmacology of DAAs with special emphasis on drug-drug interaction. PMID:28680834

KSC-08pd3868

NASA Image and Video Library

2008-11-07

CAPE CANAVERAL, Fla. -- In Building 1555 at Vandenberg Air Force Base in California, workers do a fit check on the mating of the Stage 1 to Stage 2 motors for the Taurus XL rocket that will launch NASA's Orbiting Carbon Observatory, or OCO, spacecraft. At right can be seen the avionics shelf. The avionics skirt, a graphite/epoxy structure, supports the avionics shelf and carries the primary structural loads from the fairing and payload cone. The aluminum avionics shelf supports the third stage avionics. The OCO is a new Earth-orbiting mission sponsored by NASA's Earth System Science Pathfinder Program. The launch of OCO is targeted for January. Photo credit: NASA/Randy Beaudoin, VAFB

Advanced software techniques for data management systems. Volume 1: Study of software aspects of the phase B space shuttle avionics system

NASA Technical Reports Server (NTRS)

Martin, F. H.

1972-01-01

An overview of the executive system design task is presented. The flight software executive system, software verification, phase B baseline avionics system review, higher order languages and compilers, and computer hardware features are also discussed.

An overview of autonomous rendezvous and docking system technology development at General Dynamics

NASA Technical Reports Server (NTRS)

Kuenzel, Fred

1991-01-01

The Centaur avionics suite is undergoing a dramatic modernization for the commercial, DoD Atlas and Titan programs. The system has been upgraded to the current state-of-the-art in ring laser gyro inertial sensors and Mil-Std-1750A processor technology. The Cruise Missile avionic system has similarly been evolving for many years. Integration of GPS into both systems has been underway for over five years with a follow-on cruise missile system currently in flight test. Rendezvous and Docking related studies have been conducted for over five years in support of OMV, CTV, and Advanced Upper Stages, as well as several other internal IR&D's. The avionics system and AR&D simulator demonstrated to the SATWG in November 1990 has been upgraded considerably under two IR&D programs in 1991. The Centaur modern avionics system is being flown in block upgrades which started in July of 1990. The Inertial Navigation Unit will fly in November of 1991. The Cruise Missile avionics systems have been fully tested and operationally validated in combat. The integrated AR&D system for space vehicle applications has been under development and testing since 1990. A Joint NASA / GD ARD&L System Test Program is currently being planned to validate several aspects of system performance in three different NASA test facilities in 1992.

VCSEL optical subassembly for avionics fiber optic modules

NASA Astrophysics Data System (ADS)

Hager, Harold E.; Chan, Eric Y.; Beranek, Mark W.; Hong, Chi-Shain

1996-04-01

With the growing maturation of vertical cavity surface emitting laser (VCSEL) technology as a source of commercial off-the-shelf components, the question of VCSEL suitability for use in avionics-qualifiable fiber-optic systems naturally follows. This paper addresses avionics suitability from two perspectives. First, measured performance and burn-in reliability results, determined from characterization of Honeywell VCSELs, are compared with application-based military and commercial avionics environmental requirements. Second, design guidelines for developing a cost-effective VCSEL optical subassembly (VCSEL/OSA) are outlined.

Recovery of the Space Shuttle Columbia Avionics

NASA Technical Reports Server (NTRS)

Hames, Kevin L.

2003-01-01

Lessons Learned: a) Avionics data can playa critical role in the investigation of a "close call" or accident. b) Avionics designers should think about the role their systems might play in an investigation. c) Know your data, down to the bit level. d) Know your spacecraft - follow the data. e) Internal placement of circuit cards can affect their survivability. f) Think about how to reconstruct nonvolatile memory (e.g. serialize IC's, etc.) g) Use of external assets can aid in extracting data from avionics.

Reference Avionics Architecture for Lunar Surface Systems

NASA Technical Reports Server (NTRS)

Somervill, Kevin M.; Lapin, Jonathan C.; Schmidt, Oron L.

2010-01-01

Developing and delivering infrastructure capable of supporting long-term manned operations to the lunar surface has been a primary objective of the Constellation Program in the Exploration Systems Mission Directorate. Several concepts have been developed related to development and deployment lunar exploration vehicles and assets that provide critical functionality such as transportation, habitation, and communication, to name a few. Together, these systems perform complex safety-critical functions, largely dependent on avionics for control and behavior of system functions. These functions are implemented using interchangeable, modular avionics designed for lunar transit and lunar surface deployment. Systems are optimized towards reuse and commonality of form and interface and can be configured via software or component integration for special purpose applications. There are two core concepts in the reference avionics architecture described in this report. The first concept uses distributed, smart systems to manage complexity, simplify integration, and facilitate commonality. The second core concept is to employ extensive commonality between elements and subsystems. These two concepts are used in the context of developing reference designs for many lunar surface exploration vehicles and elements. These concepts are repeated constantly as architectural patterns in a conceptual architectural framework. This report describes the use of these architectural patterns in a reference avionics architecture for Lunar surface systems elements.

Avionics system design for requirements for the United States Coast Guard HH-65A Dolphin

NASA Technical Reports Server (NTRS)

Young, D. A.

1984-01-01

Aerospatiale Helicopter Corporation (AHC) was awarded a contract by the United States Coast Guard for a new Short Range Recovery (SRR) Helicopter on 14 June 1979. The award was based upon an overall evaluation of performance, cost, and technical suitability. In this last respect, the SRR helicopter was required to meet a wide variety of mission needs for which the integrated avionics system has a high importance. This paper illustrates the rationale for the avionics system requirements, the system architecture, its capabilities and reliability and its adaptability to a wide variety of military and commercial purposes.

A method of distributed avionics data processing based on SVM classifier

NASA Astrophysics Data System (ADS)

Guo, Hangyu; Wang, Jinyan; Kang, Minyang; Xu, Guojing

2018-03-01

Under the environment of system combat, in order to solve the problem on management and analysis of the massive heterogeneous data on multi-platform avionics system, this paper proposes a management solution which called avionics "resource cloud" based on big data technology, and designs an aided decision classifier based on SVM algorithm. We design an experiment with STK simulation, the result shows that this method has a high accuracy and a broad application prospect.

Vertical Guidance Performance Analysis of the L1–L5 Dual-Frequency GPS/WAAS User Avionics Sensor

PubMed Central

Jan, Shau-Shiun

2010-01-01

This paper investigates the potential vertical guidance performance of global positioning system (GPS)/wide area augmentation system (WAAS) user avionics sensor when the modernized GPS and Galileo are available. This paper will first investigate the airborne receiver code noise and multipath (CNMP) confidence (σair). The σair will be the dominant factor in the availability analysis of an L1–L5 dual-frequency GPS/WAAS user avionics sensor. This paper uses the MATLAB Algorithm Availability Simulation Tool (MAAST) to determine the required values for the σair, so that an L1–L5 dual-frequency GPS/WAAS user avionics sensor can meet the vertical guidance requirements of APproach with Vertical guidance (APV) II and CATegory (CAT) I over conterminous United States (CONUS). A modified MAAST that includes the Galileo satellite constellation is used to determine under what user configurations WAAS could be an APV II system or a CAT I system over CONUS. Furthermore, this paper examines the combinations of possible improvements in signal models and the addition of Galileo to determine if GPS/WAAS user avionics sensor could achieve 10 m Vertical Alert Limit (VAL) within the service volume. Finally, this paper presents the future vertical guidance performance of GPS user avionics sensor for the United States’ WAAS, Japanese MTSAT-based satellite augmentation system (MSAS) and European geostationary navigation overlay service (EGNOS). PMID:22319263

NASA Affordable Vehicle Avionics (AVA). Common Modular Avionics System for Nanolaunchers Offering Affordable Access to Space; [Space Technology: Game Changing Development

NASA Technical Reports Server (NTRS)

Aquilina, Rudy

2017-01-01

Small satellites are becoming ever more capable of performing valuable missions for both government and commercial customers. However, currently these satellites can be launched affordably only as secondary payloads. This makes it difficult for the small satellite mission to launch when needed, to the desired orbit, and with acceptable risk. What is needed is a class of low-cost launchers, so that launch costs to low-Earth orbit (LEO) are commensurate with payload costs. Several private and government-sponsored launch vehicle developers are working toward just that-the ability to affordably insert small payloads into LEO. But until now, cost of the complex avionics remained disproportionately high. AVA (Affordable Vehicle Avionics) solves this problem. Significant contributors to the cost of launching nanosatellites to orbit are the avionics and software systems that steer and control the launch vehicles, sequence stage separation, deploy payloads, and telemeter data. The high costs of these guidance, navigation and control (GNC) avionics systems are due in part to the current practice of developing unique, single-use hardware and software for each launch. High-performance, high-reliability inertial sensors components with heritage from legacy launchers also contribute to costs-but can low-cost commercial inertial sensors work just as well? NASA Ames Research Center has developed and tested a prototype low-cost avionics package for space launch vehicles that provides complete GNC functionality in a package smaller than a tissue box (100 millimeters by 120 millimeters by 69 millimeters; 4 inches by 4.7 inches by 2.7 inches), with a mass of less than 0.84 kilogram (2 pounds. AVA takes advantage of commercially available, low-cost, mass-produced, miniaturized sensors, filtering their more noisy inertial data with real-time GPS (Global Positioning Satellite) data. The goal of the AVA project is to produce and light-verify a common suite of avionics and software that deliver affordable, capable GNC and telemetry avionics with application to multiple nanolaunch vehicles at 1 percent of the cost of current state-of-the-art avionics.

Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) Project: Terminal Operations HITL 1B Primary Results

NASA Technical Reports Server (NTRS)

Rorie, Conrad; Monk, Kevin; Roberts, Zach; Brandt, Summer

2018-01-01

This presentation provides an overview of the primary results from the Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) Project's second Terminal Operations human-in-the-loop simulation. This talk covers the background of this follow-on experiment, which includes an overview of the first Terminal Operations HITL performed by the project. The primary results include a look at the number and durations of detect and avoid (DAA) alerts issued by the two DAA systems under test. It also includes response time metrics and metrics on the ability of the pilot-in-command (PIC) to maintain sufficient separation. Additional interoperability metrics are included to illustrate how pilots interact with the tower controller. Implications and conclusions are covered at the end.

Avionics Instrument Systems Specialist Career Ladder: AFSCs 32531, 32551, 31571, and 32591. Occupational Survey Report.

ERIC Educational Resources Information Center

Air Force Occupational Measurement Center, Lackland AFB, TX.

The Avionics Instrument Systems career ladder (AFSC 325X1) provides flight line and shop maintenance training on aircraft instrument systems, electromechancial instruments, components, and test equipment. Duties involve inspecting, removing, installing, repairing, operating, troubleshooting, overhauling, and modifying systems such as flight and…

KSC-08pd3866

NASA Image and Video Library

2008-11-07

CAPE CANAVERAL, Fla. -- In Building 1555 at Vandenberg Air Force Base in California, ssembly is underway for the Taurus XL rocket that will launch NASA's Orbiting Carbon Observatory, or OCO, spacecraft. Lined up left to right are the Stage 1 and Stage 2 motors, the boattail, the avionics shelf and the Stage 3 motor. The graphite/epoxy boattail structure provides the transition from the smaller diameter of the Stage 2 motor to the larger diameter of the avionics skirt. The avionics skirt, also a graphite/epoxy structure, supports the avionics shelf and carries the primary structural loads from the fairing and payload cone. The aluminum avionics shelf supports the third stage avionics. The OCO is a new Earth-orbiting mission sponsored by NASA's Earth System Science Pathfinder Program. The launch of OCO is targeted for January. Photo credit: NASA/Randy Beaudoin, VAFB

Value and innovation of direct-acting antivirals: long-term health outcomes of the strategic plan for the management of hepatitis C in Spain.

PubMed

Turnes, Juan; Domínguez-Hernández, Raquel; Casado, Miguel Ángel

2017-12-01

To assess the long-term healthcare costs and health outcomes in association with the access to new direct-acting antivirals (DAAs), during the first year of the National Strategic Plan for Chronic Hepatitis C (SPCHC) in patients with chronic hepatitis C (CHC) in Spain. A decision tree and a lifetime Markov model were developed to simulate the natural history, morbidity, and mortality of a cohort of 51,900 patients with CHC before (pre-DAA strategy) and after (post-DAA strategy) access to DAAs, following SPCHC approval. The percentage of patients treated, transition probabilities, disease management costs, health state utility values, sustained virologic response rates and treatment costs were obtained from the literature and published data from Spain. The results were expressed in terms of costs (€, 2016), quality-adjusted life years (QALYs) and prevention of clinical events, with an annual discount rate of 3%. The post-DAA strategy would prevent 8,667 cases of decompensated cirrhosis, 5,471 cases of hepatocellular carcinoma, 1,137 liver transplants and 9,608 liver-related deaths. The cohort of 51,900 patients would require investments of 1,606 and 1,230 million euros with the post-DAA and pre-DAA strategies, respectively. This would produce 819,674 and 665,703 QALYs. The use of new DAA-based treatments in CHC patients during the first year after the implementation of the SPCHC significantly reduced long-term morbidity and mortality and increased quality of life; demonstrating that this plan is an efficient use of public health resources.

NASA Affordable Vehicle Avionics (AVA): Common Modular Avionics System for Nano-Launchers Offering Affordable Access to Space

NASA Technical Reports Server (NTRS)

Cockrell, James

2015-01-01

Small satellites are becoming ever more capable of performing valuable missions for both government and commercial customers. However, currently these satellites can only be launched affordably as secondary payloads. This makes it difficult for the small satellite mission to launch when needed, to the desired orbit, and with acceptable risk. NASA Ames Research Center has developed and tested a prototype low-cost avionics package for space launch vehicles that provides complete GNC functionality in a package smaller than a tissue box with a mass less than 0.84 kg. AVA takes advantage of commercially available, low-cost, mass-produced, miniaturized sensors, filtering their more noisy inertial data with realtime GPS data. The goal of the Advanced Vehicle Avionics project is to produce and flight-verify a common suite of avionics and software that deliver affordable, capable GNC and telemetry avionics with application to multiple nano-launch vehicles at 1 the cost of current state-of-the-art avionics.

Definition of avionics concepts for a heavy lift cargo vehicle, appendix A

NASA Technical Reports Server (NTRS)

1989-01-01

The major objective of the study task was to define a cost effective, multiuser simulation, test, and demonstration facility to support the development of avionics systems for future space vehicles. This volume provides the results of the main simulation processor selection study and describes some proof-of-concept demonstrations for the avionics test bed facility.

B-1B Avionics/Automatic Test Equipment: Maintenance Queueing Analysis.

DTIC Science & Technology

1983-12-01

analysis (which is logistics terminology for an avionics/ATE queueing analysis). To allow each vendor the opportunity to perform such an analysis...for system performance measures may be found for the queueing system in Figure 7. This is due to the preemptive blocking caused by ATE failures. The...D-R14l1i75 B-iB AVIONICS/AUTOMPTIC TEST EQUIPMENT: MRINTENRNCE 1/2 QUEUEING RNRLYSIS(U) RIP FORCE INST OF TECH HRIGHT-PRTTERSON RFB OH SCHOOL OF

Current treatment of chronic hepatitis C in China: Dilemma and potential problems

PubMed Central

Han, Qun-Ying; Liu, Zheng-Wen

2016-01-01

Major advances have been made in the treatment of chronic hepatitis C virus (HCV) infection with the advent of direct-acting antiviral agents (DAAs). China has the most cases of HCV infection worldwide, but none of the DAAs has been approved in mainland China so far, and interferon (IFN)-α-based treatment remains the standard of care. HCV patients without response or with contraindications to IFN-based therapy have no alternative options. However, many patients buy DAAs, especially the generic forms of sofosbuvir, from other countries or areas. Under these circumstances, the use of these drugs may cause many predictable and unpredictable problems in ethics, law and medical practice. Given the obstacles of legal accessibility to DAAs and the potential problems of obtaining and using DAAs in China, the early launching of the DAAs in China or the legalization of buying drugs from areas outside China and using these drugs in China is an urgent issue and needs to be dealt with as soon as possible, in the interest of the patients. PMID:27217693

Current treatment of chronic hepatitis C in China: Dilemma and potential problems.

PubMed

Han, Qun-Ying; Liu, Zheng-Wen

2016-05-21

Major advances have been made in the treatment of chronic hepatitis C virus (HCV) infection with the advent of direct-acting antiviral agents (DAAs). China has the most cases of HCV infection worldwide, but none of the DAAs has been approved in mainland China so far, and interferon (IFN)-α-based treatment remains the standard of care. HCV patients without response or with contraindications to IFN-based therapy have no alternative options. However, many patients buy DAAs, especially the generic forms of sofosbuvir, from other countries or areas. Under these circumstances, the use of these drugs may cause many predictable and unpredictable problems in ethics, law and medical practice. Given the obstacles of legal accessibility to DAAs and the potential problems of obtaining and using DAAs in China, the early launching of the DAAs in China or the legalization of buying drugs from areas outside China and using these drugs in China is an urgent issue and needs to be dealt with as soon as possible, in the interest of the patients.

Transcription of the Workshop on General Aviation Advanced Avionics Systems

NASA Technical Reports Server (NTRS)

Tashker, M. (Editor)

1975-01-01

Papers are presented dealing with the design of reliable, low cost, advanced avionics systems applicable to general aviation in the 1980's and beyond. Sensors, displays, integrated circuits, microprocessors, and minicomputers are among the topics discussed.

Analysis of technology requirements and potential demand for general aviation avionics systems for operation in the 1980's

NASA Technical Reports Server (NTRS)

Cohn, D. M.; Kayser, J. H.; Senko, G. M.; Glenn, D. R.

1974-01-01

Avionics systems are identified which promise to reduce economic constraints and provide significant improvements in performance, operational capability and utility for general aviation aircraft in the 1980's.

Crew Launch Vehicle (CLV) Avionics and Software Integration Overview

NASA Technical Reports Server (NTRS)

Monell, Donald W.; Flynn, Kevin C.; Maroney, Johnny

2006-01-01

On January 14, 2004, the President of the United States announced a new plan to explore space and extend a human presence across our solar system. The National Aeronautics and Space Administration (NASA) established the Exploration Systems Mission Directorate (ESMD) to develop and field a Constellation Architecture that will bring the Space Exploration vision to fruition. The Constellation Architecture includes a human-rated Crew Launch Vehicle (CLV) segment, managed by the Marshall Space Flight Center (MSFC), comprised of the First Stage (FS), Upper Stage (US), and Upper Stage Engine (USE) elements. The CLV s purpose is to provide safe and reliable crew and cargo transportation into Low Earth Orbit (LEO), as well as insertion into trans-lunar trajectories. The architecture's Spacecraft segment includes, among other elements, the Crew Exploration Vehicle (CEV), managed by the Johnson Space Flight Center (JSC), which is launched atop the CLV. MSFC is also responsible for CLV and CEV stack integration. This paper provides an overview of the Avionics and Software integration approach (which includes the Integrated System Health Management (ISHM) functions), both within the CLV, and across the CEV interface; it addresses the requirements to be met, logistics of meeting those requirements, and the roles of the various groups. The Avionics Integration and Vehicle Systems Test (ANST) Office was established at the MSFC with system engineering responsibilities for defining and developing the integrated CLV Avionics and Software system. The AIVST Office has defined two Groups, the Avionics and Software Integration Group (AVSIG), and the Integrated System Simulation and Test Integration Group (ISSTIG), and four Panels which will direct trade studies and analyses to ensure the CLV avionics and software meet CLV system and CEV interface requirements. The four panels are: 1) Avionics Integration Panel (AIP), 2) Software Integration Panel, 3) EEE Panel, and 4) Systems Simulation and Test Panel. Membership on the groups and panels includes the MSFC representatives from the requisite engineering disciplines, the First Stage, the Upper Stage, the Upper Stage Engine projects, and key personnel from other NASA centers. The four panels will take the results of trade studies and analyses and develop documentation in support of Design Analysis Cycle Reviews and ultimately the System Requirements Review.

Preliminary Candidate Advanced Avionics System (PCAAS). [reduction in single pilot workload during instrument flight rules flight

NASA Technical Reports Server (NTRS)

Teper, G. L.; Hon, R. H.; Smyth, R. K.

1977-01-01

Specifications which define the system functional requirements, the subsystem and interface needs, and other requirements such as maintainability, modularity, and reliability are summarized. A design definition of all required avionics functions and a system risk analysis are presented.

V/STOLAND avionics system flight-test data on a UH-1H helicopter

NASA Technical Reports Server (NTRS)

Baker, F. A.; Jaynes, D. N.; Corliss, L. D.; Liden, S.; Merrick, R. B.; Dugan, D. C.

1980-01-01

The flight-acceptance test results obtained during the acceptance tests of the V/STOLAND (versatile simplex digital avionics system) digital avionics system on a Bell UH-1H helicopter in 1977 at Ames Research Center are presented. The system provides navigation, guidance, control, and display functions for NASA terminal area VTOL research programs and for the Army handling qualities research programs at Ames Research Center. The acceptance test verified system performance and contractual acceptability. The V/STOLAND hardware navigation, guidance, and control laws resident in the digital computers are described. Typical flight-test data are shown and discussed as documentation of the system performance at acceptance from the contractor.

Des-aspartate-angiotensin I causes specific release of PGE2 and PGI2 in HUVEC via the angiotensin AT1 receptor and biased agonism.

PubMed

Wen, Qiang; Lee, Kok-Onn; Sim, Sai-Zhen; Xu, Xiao-Guang; Sim, Meng-Kwoon

2015-12-05

DAA-I (des-aspartate-angiotensin I), an endogenous angiotensin, had been shown earlier to ameliorate animal models of cardiovascular diseases via the angiotensin AT1 receptor and prostaglandins. The present study investigated further the action of DAA-I on the release of PGE2, PGI2, PGF2α and TXA2 in HUVEC. 10(-11)-10(-8)M DAA-I and 15min incubation specifically released PGE2 and PGI2. The release was inhibited by losartan and indomethacin but not by PD123319 and NS398 indicating that the angiotensin AT1 receptor and COX-1 mediate the release. At concentrations higher than 10(-7)M, DAA-I mimics the action of angiotensin II by releasing TXA2 but had no effect on the production of PGF2α. At similar concentrations and 4h incubation, DAA-I increased the release of the 4 prostaglandins via the angiotensin AT1 receptor and COX-2, again mimicking the action of angiotensin II. HUVEC that were preincubated with DAA-I or angiotensin II, released similar profiles of prostaglandins when incubated with arachidonic acid after the angiotensin had been washed off. We postulate that the internalized DAA-I/receptor complex remains active and mediates the conversion of arachidonic acid to the respective prostaglandins. The release of PGE2 and PGI2 via the angiotensin AT1 receptor and COX-1 is a novel specific action of DAA-I and is likely responsible for its beneficial effects seen in earlier studies. This specific action is definable as a biased agonism of the angiotensin AT1 receptor, which identifies DAA-I as a novel biased agonist and potential therapeutic that is able to produce specific prostaglandins at nanomolar concentrations. Copyright © 2015 Elsevier B.V. All rights reserved.

Strategic avionics technology planning

NASA Technical Reports Server (NTRS)

Cox, Kenneth J.; Brown, Don C.

1991-01-01

NASA experience in development and insertion of technology into programs had led to a recognition that a Strategic Plan for Avionics is needed for space. In the fall of 1989 an Avionics Technology Symposium was held in Williamsburg, Virginia. In early 1990, as a followon, a NASA wide Strategic Avionics Technology Working Group was chartered by NASA Headquarters. This paper will describe the objectives of this working group, technology bridging, and approaches to incentivize both the federal and commercial sectors to move toward rapidly developed, simple, and reliable systems with low life cycle cost.

Digital avionics: A cornerstone of aviation

NASA Technical Reports Server (NTRS)

Spitzer, Cary R.

1990-01-01

Digital avionics is continually expanding its role in communication (HF and VHF, satellite, data links), navigation (ground-based systems, inertial and satellite-based systems), and flight-by-wire control. Examples of electronic flight control system architecture, pitch, roll, and yaw control are presented. Modeling of complex hardware systems, electromagnetic interference, and software are discussed.

Avionics system design for high energy fields: A guide for the designer and airworthiness specialist

NASA Technical Reports Server (NTRS)

Mcconnell, Roger A.

1987-01-01

Because of the significant differences in transient susceptibility, the use of digital electronics in flight critical systems, and the reduced shielding effects of composite materials, there is a definite need to define pracitices which will minimize electromagnetic susceptibility, to investigate the operational environment, and to develop appropriate testing methods for flight critical systems. The design practices which will lead to reduced electromagnetic susceptibility of avionics systems in high energy fields is described. The levels of emission that can be anticipated from generic digital devices. It is assumed that as data processing equipment becomes an ever larger part of the avionics package, the construction methods of the data processing industry will increasingly carry over into aircraft. In Appendix 1 tentative revisions to RTCA DO-160B, Environmental Conditions and Test Procedures for Airborne Equipment, are presented. These revisions are intended to safeguard flight critical systems from the effects of high energy electromagnetic fields. A very extensive and useful bibliography on both electromagnetic compatibility and avionics issues is included.

Quantifying antiviral activity optimizes drug combinations against hepatitis C virus infection.

PubMed

Koizumi, Yoshiki; Ohashi, Hirofumi; Nakajima, Syo; Tanaka, Yasuhito; Wakita, Takaji; Perelson, Alan S; Iwami, Shingo; Watashi, Koichi

2017-02-21

With the introduction of direct-acting antivirals (DAAs), treatment against hepatitis C virus (HCV) has significantly improved. To manage and control this worldwide infectious disease better, the "best" multidrug treatment is demanded based on scientific evidence. However, there is no method available that systematically quantifies and compares the antiviral efficacy and drug-resistance profiles of drug combinations. Based on experimental anti-HCV profiles in a cell culture system, we quantified the instantaneous inhibitory potential (IIP), which is the logarithm of the reduction in viral replication events, for both single drugs and multiple-drug combinations. From the calculated IIP of 15 anti-HCV drugs from different classes [telaprevir, danoprevir, asunaprevir, simeprevir, sofosbuvir (SOF), VX-222, dasabuvir, nesbuvir, tegobuvir, daclatasvir, ledipasvir, IFN-α, IFN-λ1, cyclosporin A, and SCY-635], we found that the nucleoside polymerase inhibitor SOF had one of the largest potentials to inhibit viral replication events. We also compared intrinsic antiviral activities of a panel of drug combinations. Our quantification analysis clearly indicated an advantage of triple-DAA treatments over double-DAA treatments, with triple-DAA treatments showing enhanced antiviral activity and a significantly lower probability for drug resistance to emerge at clinically relevant drug concentrations. Our framework provides quantitative information to consider in designing multidrug strategies before costly clinical trials.

First order reversal curve study of the dipolar interaction in Ni three-dimensional antidot arrays

NASA Astrophysics Data System (ADS)

Li, Bingqing; Chai, Xuzhao; Moeendarbari, Sina; Hao, Yaowu; Gilbert, Dustin A.; Liu, Kai; Zhang, Di; Feng, Gang; Han, Ping; Cheng, X. M.

2014-03-01

Three-dimensional antidot arrays (3DAAs) have attracted considerable attention due to potential applications in sensors, energy storage and transducers. Magnetic 3DAAs also provide an ideal system for studying the effect of dimensionality and morphology on magnetic properties. We report study of dipolar interactions in Ni 3DAAs using the first-order reversal curve (FORC) method. Ordered Ni 3DAAs were fabricated by electrochemical deposition into colloidal crystal templates of self-assembled polystyrene spheres. The samples have the same pore size of about 500 nm but different thicknesses, ranging from 0.3 μm to 1.2 μm, confirmed by scanning electron microscopy (SEM) and atomic force microscopy (AFM). FORCs of the samples with thicknesses of 0.3 μm, 0.8 μm, and 1.2 μm were measured by a vibrating sample magnetometer. The FORC diagram analysis reveals a demagnetizing magnetic dipolar interaction, and a decrease in the interaction strength with the increasing sample thickness, evidenced by a decrease in the spread of the irreversible peak in the bias distribution, as well as a decrease in the tilting of the FORC distribution from the local coercivity axis. Work at BMC and UCD is supported by NSF DMR-1207085 and DMR-1008791, respectively.

The natural phytochemical dehydroabietic acid is an anti-aging reagent that mediates the direct activation of SIRT1.

PubMed

Kim, Juewon; Kang, Young-Gyu; Lee, Jee-young; Choi, Dong-hwa; Cho, Young-uk; Shin, Jae-Min; Park, Jun Seong; Lee, John Hwan; Kim, Wan Gi; Seo, Dae Bang; Lee, Tae Ryong; Miyamoto, Yusei; No, Kyoung Tai

2015-09-05

Dehydroabietic acid (DAA) is a naturally occurring diterpene resin acid of confers, such as pinus species (P. densiflora, P. sylvestris) and grand fir (Abies grandis), and it induces various biological actions including antimicrobial, antiulcer, and cardiovascular activities. The cellular targets that mediate these actions are largely unknown yet. In this report, we suggest that DAA is an anti-aging reagent. DAA has lifespan extension effects in Caenorhabditis elegans, prevents lipofuscin accumulation, and prevents collagen secretion in human dermal fibroblasts. We found that these anti-aging effects are primarily mediated by SIRT1 activation. Lifespan extension effects by DAA were ameliorated in sir-2.1 mutants and SIRT1 protein expression was increased, resulting in the deacetylation of SIRT1 target protein PGC-1α. Moreover, DAA binds directly to the SIRT1 protein independent of the SIRT1 substrate NAD(+) levels. Through a molecular docking study, we also propose a binding model for DAA-SIRT1. Taken together, our results demonstrate that the anti-aging effects are the first identified biological property of DAA and that the direct activation of SIRT1 enzymatic activity suggests the potential use of this natural diterpene, or related compounds, in age-related diseases or as a preventive reagent against the aging process. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

The Generic Resolution Advisor and Conflict Evaluator (GRACE) for Unmanned Aircraft Detect-And-Avoid Systems

NASA Technical Reports Server (NTRS)

Abramson, Michael; Refai, Mohamad; Santiago, Confesor

2017-01-01

The paper describes the Generic Resolution Advisor and Conflict Evaluator (GRACE), a novel alerting and guidance algorithm that combines flexibility, robustness, and computational efficiency. GRACE is generic since it was designed without any assumptions regarding temporal or spatial scales, aircraft performance, or its sensor and communication systems. Therefore, GRACE was adopted as a core component of the Java Architecture for Detect-And-Avoid (DAA) Extensibility and Modeling, developed by NASA as a research and modeling tool for Unmanned Aerial Systems Integration in the National Airspace System (NAS). GRACE has been used in a number of real-time and fast-time experiments supporting evolving requirements of DAA research, including parametric studies, NAS-wide simulations, human-in-the-loop experiments, and live flight tests.

KSC-08pd3867

NASA Image and Video Library

2008-11-07

CAPE CANAVERAL, Fla. -- In Building 1555 at Vandenberg Air Force Base in California, assembly is underway for the Taurus XL rocket that will launch NASA's Orbiting Carbon Observatory, or OCO, spacecraft. In the foreground at left is the boattail; behind it is the Stage 0 Castor 120 motor. At right near the wall (from left) are the Stage 1 and Stage 2 motors, the avionics shelf and the Stage 3 motor. The graphite/epoxy boattail structure provides the transition from the smaller diameter of the Stage 2 motor to the larger diameter of the avionics skirt. The avionics skirt, also a graphite/epoxy structure, supports the avionics shelf and carries the primary structural loads from the fairing and payload cone. The aluminum avionics shelf supports the third stage avionics. The OCO is a new Earth-orbiting mission sponsored by NASA's Earth System Science Pathfinder Program. The launch of OCO is targeted for January. Photo credit: NASA/Randy Beaudoin, VAFB

Avionics Architectures for Exploration: Building a Better Approach for (Human) Spaceflight Avionics

NASA Technical Reports Server (NTRS)

Goforth, Montgomery B.; Ratliff, James E.; Hames, Kevin L.; Vitalpur, Sharada V.

2014-01-01

The field of Avionics is advancing far more rapidly in terrestrial applications than in space flight applications. Spaceflight Avionics are not keeping pace with expectations set by terrestrial experience, nor are they keeping pace with the need for increasingly complex automation and crew interfaces as we move beyond Low Earth Orbit. NASA must take advantage of the strides being made by both space-related and terrestrial industries to drive our development and sustaining costs down. This paper describes ongoing efforts by the Avionics Architectures for Exploration (AAE) project chartered by NASA's Advanced Exploration Systems (AES) Program to evaluate new avionic architectures and technologies, provide objective comparisons of them, and mature selected technologies for flight and for use by other AES projects. Results from the AAE project's FY13 efforts are discussed, along with the status of FY14 efforts and future plans.

Advanced information processing system for advanced launch system: Avionics architecture synthesis

NASA Technical Reports Server (NTRS)

Lala, Jaynarayan H.; Harper, Richard E.; Jaskowiak, Kenneth R.; Rosch, Gene; Alger, Linda S.; Schor, Andrei L.

1991-01-01

The Advanced Information Processing System (AIPS) is a fault-tolerant distributed computer system architecture that was developed to meet the real time computational needs of advanced aerospace vehicles. One such vehicle is the Advanced Launch System (ALS) being developed jointly by NASA and the Department of Defense to launch heavy payloads into low earth orbit at one tenth the cost (per pound of payload) of the current launch vehicles. An avionics architecture that utilizes the AIPS hardware and software building blocks was synthesized for ALS. The AIPS for ALS architecture synthesis process starting with the ALS mission requirements and ending with an analysis of the candidate ALS avionics architecture is described.

Systems engineering and integration: Advanced avionics laboratories

NASA Technical Reports Server (NTRS)

1990-01-01

In order to develop the new generation of avionics which will be necessary for upcoming programs such as the Lunar/Mars Initiative, Advanced Launch System, and the National Aerospace Plane, new Advanced Avionics Laboratories are required. To minimize costs and maximize benefits, these laboratories should be capable of supporting multiple avionics development efforts at a single location, and should be of a common design to support and encourage data sharing. Recent technological advances provide the capability of letting the designer or analyst perform simulations and testing in an environment similar to his engineering environment and these features should be incorporated into the new laboratories. Existing and emerging hardware and software standards must be incorporated wherever possible to provide additional cost savings and compatibility. Special care must be taken to design the laboratories such that real-time hardware-in-the-loop performance is not sacrificed in the pursuit of these goals. A special program-independent funding source should be identified for the development of Advanced Avionics Laboratories as resources supporting a wide range of upcoming NASA programs.

An integrated autonomous rendezvous and docking system architecture using Centaur modern avionics

NASA Technical Reports Server (NTRS)

Nelson, Kurt

1991-01-01

The avionics system for the Centaur upper stage is in the process of being modernized with the current state-of-the-art in strapdown inertial guidance equipment. This equipment includes an integrated flight control processor with a ring laser gyro based inertial guidance system. This inertial navigation unit (INU) uses two MIL-STD-1750A processors and communicates over the MIL-STD-1553B data bus. Commands are translated into load activation through a Remote Control Unit (RCU) which incorporates the use of solid state relays. Also, a programmable data acquisition system replaces separate multiplexer and signal conditioning units. This modern avionics suite is currently being enhanced through independent research and development programs to provide autonomous rendezvous and docking capability using advanced cruise missile image processing technology and integrated GPS navigational aids. A system concept was developed to combine these technologies in order to achieve a fully autonomous rendezvous, docking, and autoland capability. The current system architecture and the evolution of this architecture using advanced modular avionics concepts being pursued for the National Launch System are discussed.

The Generic Resolution Advisor and Conflict Evaluator (GRACE) for Detect-And-Avoid (DAA) Systems

NASA Technical Reports Server (NTRS)

Abramson, Michael; Refai, Mohamad; Santiago, Confesor

2017-01-01

The paper describes the Generic Resolution Advisor and Conflict Evaluator (GRACE), a novel alerting and guidance algorithm that combines flexibility, robustness, and computational efficiency. GRACE is "generic" in that it makes no assumptions regarding temporal or spatial scales, aircraft performance, or its sensor and communication systems. Accordingly, GRACE is well suited to research applications where alerting and guidance is a central feature and requirements are fluid involving a wide range of aviation technologies. GRACE has been used at NASA in a number of real-time and fast-time experiments supporting evolving requirements of DAA research, including parametric studies, NAS-wide simulations, human-in-the-loop experiments, and live flight tests.

Case Study of the Space Shuttle Cockpit Avionics Upgrade Software

NASA Technical Reports Server (NTRS)

Ferguson, Roscoe C.; Thompson, Hiram C.

2005-01-01

The purpose of the Space Shuttle Cockpit Avionics Upgrade project was to reduce crew workload and improve situational awareness. The upgrade was to augment the Shuttle avionics system with new hardware and software. An early version of this system was used to gather human factor statistics in the Space Shuttle Motion Simulator of the Johnson Space Center for one month by multiple teams of astronauts. The results were compiled by NASA Ames Research Center and it was was determined that the system provided a better than expected increase in situational awareness and reduction in crew workload. Even with all of the benefits nf the system, NASA cancelled the project towards the end of the development cycle. A major success of this project was the validation of the hardware architecture and software design. This was significant because the project incorporated new technology and approaches for the development of human rated space software. This paper serves as a case study to document knowledge gained and techniques that can be applied for future space avionics development efforts. The major technological advances were the use of reflective memory concepts for data acquisition and the incorporation of Commercial off the Shelf (COTS) products in a human rated space avionics system. The infused COTS products included a real time operating system, a resident linker and loader, a display generation tool set, and a network data manager. Some of the successful design concepts were the engineering of identical outputs in multiple avionics boxes using an event driven approach and inter-computer communication, a reconfigurable data acquisition engine, the use of a dynamic bus bandwidth allocation algorithm. Other significant experiences captured were the use of prototyping to reduce risk, and the correct balance between Object Oriented and Functional based programming.

Digital Avionics Information System (DAIS): Training Requirements Analysis Model (TRAMOD).

ERIC Educational Resources Information Center

Czuchry, Andrew J.; And Others

The training requirements analysis model (TRAMOD) described in this report represents an important portion of the larger effort called the Digital Avionics Information System (DAIS) Life Cycle Cost (LCC) Study. TRAMOD is the second of three models that comprise an LCC impact modeling system for use in the early stages of system development. As…

Content analysis of disease awareness advertisements in popular Australian women's magazines.

PubMed

Hall, Danika V; Jones, Sandra C; Iverson, Donald C

To examine the nature of disease awareness advertising (DAA). Therapeutic advertisements in six popular Australian women's magazines were monitored between April 2006 and March 2007. A subset of advertisements was included in the study based on criteria derived from a definition of DAA. Unique advertisements were analysed by four independent coders. Types of advertisements and their sponsors, the types of disease information present, and the persuasive techniques utilised. Of 711 advertisements identified, 60 met the inclusion criteria for DAA, and 30 of these were unique. Over one-third of the advertisements were classified as "unbranded product advertisements", which promote a product without referring directly to a brand. DAA sponsored by pharmaceutical companies most often provided treatment and prevalence information. Most (22/30) advertisements used emotional appeals; 15 of these used "happiness/healthiness/wellbeing". The educational value of industry-sponsored DAA could be improved if regulations and guidelines stipulated disease information requirements, such as inclusion of risk-factor and symptom information. Regulators should provide guidelines for "unbranded product advertisements" and the acceptability of other persuasive techniques. Further research into DAA is required and should consider advertisements in a range of media, and behavioural responses.

Payload accommodations. Avionics payload support architecture

NASA Technical Reports Server (NTRS)

Creasy, Susan L.; Levy, C. D.

1990-01-01

Concepts for vehicle and payload avionics architectures for future NASA programs, including the Assured Shuttle Access program, Space Station Freedom (SSF), Shuttle-C, Advanced Manned Launch System (AMLS), and the Lunar/Mars programs are discussed. Emphasis is on the potential available to increase payload services which will be required in the future, while decreasing the operational cost/complexity by utilizing state of the art advanced avionics systems and a distributed processing architecture. Also addressed are the trade studies required to determine the optimal degree of vehicle (NASA) to payload (customer) separation and the ramifications of these decisions.

A COTS-Based Replacement Strategy for Aging Avionics Computers

DTIC Science & Technology

2001-12-01

Communication Control Unit. A COTS-Based Replacement Strategy for Aging Avionics Computers COTS Microprocessor Real Time Operating System New Native Code...Native Code Objec ts Native Code Thread Real - Time Operating System Legacy Function x Virtual Component Environment Context Switch Thunk Add-in Replace

Effectiveness and security of chronic hepatitis C treatment in coinfected patients in real-world.

PubMed

Uriarte-Pinto, Moisés; Navarro-Aznarez, Herminia; De La Llama-Celis, Natalia; Arazo-Garcés, Piedad; Martínez-Sapiña, Ana María; Abad-Sazatornil, María Reyes

2018-06-01

Background HIV-HCV coinfection produces high morbi-mortality. Direct-acting antivirals (DAAs) have shown high efficacy, although special attention should be paid to the risk of drug interactions. However, due to the lack of representativeness of coinfected patients in clinical trials, it is important to know real-world results. Objective To evaluate DAA treatment effectiveness in coinfected patients. We also analyse safety profile of DAA treatment and drug interactions between HCV and HIV therapy. Setting Descriptive study carried in a tertiary hospital of Spain Method HIV-HCV coinfected patients treated with DAAs between November 2014 and June 2016 were included. Main outcome measure Efficacy was measured in terms of sustained virologic response at week 12 after the end of therapy. Adverse events that led to treatment discontinuation were registered to evaluate the safety profile, and also drug interactions between DAAs and antiretroviral treatment were evaluated. Results Main HCV genotypes were 1a (34.9%) and 4 (24.5%). 51.9% were HCV previously treated, 54.7% had grade 4 liver fibrosis. SVR12 was reported in 90.6%. HCV treatment was well tolerated and there were no discontinuations because of adverse events. 30.2% of HIV treatments had to be modified before DAA treatment was started due to interactions, HIV suppression was not compromised. Conclusion DAA treatment in coinfected patients seems to be highly effective and secure. Evaluation of drug interactions must be a priority in order to maximize effectiveness and avoid toxicity.

Preliminary candidate advanced avionics system for general aviation

NASA Technical Reports Server (NTRS)

Mccalla, T. M.; Grismore, F. L.; Greatline, S. E.; Birkhead, L. M.

1977-01-01

An integrated avionics system design was carried out to the level which indicates subsystem function, and the methods of overall system integration. Sufficient detail was included to allow identification of possible system component technologies, and to perform reliability, modularity, maintainability, cost, and risk analysis upon the system design. Retrofit to older aircraft, availability of this system to the single engine two place aircraft, was considered.

A framework for building real-time expert systems

NASA Technical Reports Server (NTRS)

Lee, S. Daniel

1991-01-01

The Space Station Freedom is an example of complex systems that require both traditional and artificial intelligence (AI) real-time methodologies. It was mandated that Ada should be used for all new software development projects. The station also requires distributed processing. Catastrophic failures on the station can cause the transmission system to malfunction for a long period of time, during which ground-based expert systems cannot provide any assistance to the crisis situation on the station. This is even more critical for other NASA projects that would have longer transmission delays (e.g., the lunar base, Mars missions, etc.). To address these issues, a distributed agent architecture (DAA) is proposed that can support a variety of paradigms based on both traditional real-time computing and AI. The proposed testbed for DAA is an autonomous power expert (APEX) which is a real-time monitoring and diagnosis expert system for the electrical power distribution system of the space station.

IgE binding to peanut allergens is inhibited by combined D-aspartic and D-glutamic acids

USDA-ARS?s Scientific Manuscript database

D-amino acids (D-aas) are reported to bind to IgE antibodies from people with allergy and asthma. The objectives of this study were to determine if D-aas bind or inhibit IgE binding to peanut allergens, and if they are more effective than L-amino acids (L-aas) in this respect. Several D-aa cocktails...

Sail GTS ground system analysis: Avionics system engineering

NASA Technical Reports Server (NTRS)

Lawton, R. M.

1977-01-01

A comparison of two different concepts for the guidance, navigation and control test set signal ground system is presented. The first is a concept utilizing a ground plate to which crew station, avionics racks, electrical power distribution system, master electrical common connection assembly and marshall mated elements system grounds are connected by 4/0 welding cable. An alternate approach has an aluminum sheet interconnecting the signal ground reference points between the crew station and avionics racks. The comparison analysis quantifies the differences between the two concepts in terms of dc resistance, ac resistance and inductive reactance. These parameters are figures of merit for ground system conductors in that the system with the lowest impedance is the most effective in minimizing noise voltage. Although the welding cable system is probably adequate, the aluminum sheet system provides a higher probability of a successful system design.

The pedagogical value of Disassemble/Analyze/Assemble (DAA) activities: Assessing the potential for motivation and transfer

NASA Astrophysics Data System (ADS)

Dalrymple, Odesma Onika

Undergraduate engineering institutions are currently seeking to improve recruiting practices and to retain engineering majors particularly by addressing what many studies document as a major challenge of poor instruction. There is an undisputed need for instructional practices that motivate students in addition to facilitating the transfer of learning beyond the classroom. Reverse engineering and product dissection, more broadly termed Disassemble/Analyze/Assemble (DAA) activities, have shown potential to address these concerns, based on the reviews of students and professors alike. DAA activities involve the systematic deconstruction of an artifact, the subsequent analysis and possible reconstruction of its components for the purpose of understanding the embodied fundamental concepts, design principles and developmental processes. These activities have been part of regular industry practice for some time; however, the systematic analysis of their benefits for learning and instruction is a relatively recent phenomenon. A number of studies have provided highly descriptive accounts of curricula and possible outcomes of DAA activities; but, relatively few have compared participants doing DAA activities to a control group doing more traditional activities. In this respect, two quasi-experiments were conducted as part of a first-year engineering laboratory, and it was hypothesized that students who engaged in the DAA activity would be more motivated and would demonstrate higher frequencies of transfer than the control. A DAA activity that required students to disassemble a single-use camera and analyze its components to discover how it works was compared to a step-by-step laboratory activity in the first experiment and a lecture method of instruction in the second experiment. In both experiments, over forty percent of the students that engaged in the DAA activity demonstrated the ability to transfer the knowledge gained about the functions of the camera's components and their interconnectedness and describe an approach for modifying the camera that involved the adaptation of a current mechanism to add new functionality. This exhibition of transfer was significantly greater than the frequency of transfer yielded by the comparative traditional activities. In addition, the post laboratory surveys indicated that the DAA activities elicited significantly higher levels of motivation than the step-by-step laboratory and the direct instructional method.

War-gaming application for future space systems acquisition

NASA Astrophysics Data System (ADS)

Nguyen, Tien M.; Guillen, Andy T.

2016-05-01

Recently the U.S. Department of Defense (DOD) released the Defense Innovation Initiative (DII) [1] to focus DOD on five key aspects; Aspect #1: Recruit talented and innovative people, Aspect #2: Reinvigorate war-gaming, Aspect #3: Initiate long-range research and development programs, Aspect #4: Make DOD practices more innovative, and Aspect #5: Advance technology and new operational concepts. Per DII instruction, this paper concentrates on Aspect #2 and Aspect #4 by reinvigorating the war-gaming effort with a focus on an innovative approach for developing the optimum Program and Technical Baselines (PTBs) and their corresponding optimum acquisition strategies for acquiring future space systems. The paper describes a unified approach for applying the war-gaming concept for future DOD acquisition of space systems. The proposed approach includes a Unified Game-based Acquisition Framework (UGAF) and an Advanced Game-Based Mathematical Framework (AGMF) using Bayesian war-gaming engines to optimize PTB solutions and select the corresponding optimum acquisition strategies for acquiring a space system. The framework defines the action space for all players with a complete description of the elements associated with the games, including Department of Defense Acquisition Authority (DAA), stakeholders, warfighters, and potential contractors, War-Gaming Engines (WGEs) played by DAA, WGEs played by Contractor (KTR), and the players' Payoff and Cost functions (PCFs). The AGMF presented here addresses both complete and incomplete information cases. The proposed framework provides a recipe for the DAA and USAF-Space and Missile Systems Center (SMC) to acquire future space systems optimally.

NextGen Avionics Roadmap Version 2.0

DTIC Science & Technology

2011-09-30

Avoid system (e.g. self -separation system) to be specifically authorized and delegated authority by the air traffic service provider in...provide any traffic flow management services within self -separation airspace. Aircraft must meet equi- page requirements to enter self -separation... traffic management systems and aircraft avionics systems. Aviation stakeholders will also benefit from reading this document because it provides a

Cockpit avionics integration and automation

NASA Technical Reports Server (NTRS)

Pischke, Keith M.

1990-01-01

Information on cockpit avionics integration and automation is given in viewgraph form, with a number of photographs. The benefits of cockpit integration are listed. The MD-11 flight guidance/flight deck system is illustrated.

An Analysis of the Modes and States for Generic Avionics

NASA Technical Reports Server (NTRS)

Wray, Richard B.

1993-01-01

The objective of this study was to develop a topology for describing the behavior of mission, vehicle and system/substem entities in new flight vehicle designs based on the use of open standards. It also had to define and describe the modes and states which may be used in generic avionics behavioral descriptions, describe their interrelationships, and establish a method for applying generic avionics to actual flight vehicle designs.

Highly Efficient Transmitter for High Peak to Average Power Ratio (PAPR) Waveforms

DTIC Science & Technology

2011-01-19

on the modulated signal topology. N00039-10-C-0071 Page 1 ACRONYM DESCRIPTION FREQUENCY Lower Upper MHz MHz ACAS Avionics Identification ...450 GSM Global Mobile Communications 380 921 HAVE QUICK Military Aircraft Radio 225 400 IFF Avionics Identification . Collision Avoidance and...Channel Ground Air Radio System 30 88 TCAS Avionics Identification , Collision Avoidance and Traffic Alert 1030 1090 VIII Air Traffic Control (Civilian

Digital Avionics Information System (DAIS): Mid-1980's Maintenance Task Analysis. Final Report.

ERIC Educational Resources Information Center

Czuchry, Andrew J.; And Others

The fundamental objective of the Digital Avionics Information System (DAIS) Life Cycle Cost (LCC) Study is to provide the Air Force with an enhanced in-house capability to incorporate LCC considerations during all stages of the system acquisition process. The purpose of this report is to describe the technical approach, results, and conclusions…

Digital Avionics Information System (DAIS): Impact of DAIS Concept on Life Cycle Cost--Supplement. Final Report.

ERIC Educational Resources Information Center

Goclowski, John C.; And Others

This supplement to a technical report providing the results of a preliminary investigation of the potential impact of the Digital Avionics Information System (DAIS) concept on system support personnel requirements and life cycle cost (LCC) includes: (1) additional details of the cost comparison of a hypothetical application of a conceptual…

Low-Cost Avionics Simulation for Aircrew Training.

ERIC Educational Resources Information Center

Edwards, Bernell J.

This report documents an experiment to determine the training effectiveness of a microcomputer-based avionics system trainer as a cost-effective alternative to training in the actual aircraft. Participants--26 operationally qualified C-141 pilots with no prior knowledge of the Fuel Saving Advisory System (FSAS), a computerized fuel management…

Avionics Instrument Systems Specialist (AFSC 32551).

ERIC Educational Resources Information Center

Miller, Lawrence B.; Crowcroft, Robert A.

This six-volume student text is designed for use by Air Force personnel enrolled in a self-study extension course for avionics instrument systems specialists. Covered in the individual volumes are career field familiarization (career field progression and training, security, occupational safety and health, and career field reference material);…

78 FR 70848 - Special Conditions: Boeing Model 777-200, -300, and -300ER Series Airplanes; Aircraft Electronic...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-27

... the EFB architecture and existing airplane network systems. The applicable airworthiness regulations..., software-configurable avionics, and fiber-optic avionics networks. The proposed Class 3 EFB architecture is... existing regulations and guidance material did not anticipate this type of system architecture or...

78 FR 70849 - Special Conditions: Boeing Model 777-200, -300, and -300ER Series Airplanes; Aircraft Electronic...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-27

... the EFB architecture and existing airplane network systems. The applicable airworthiness regulations..., software-configurable avionics, and fiber-optic avionics networks. The proposed Class 3 EFB architecture is... existing regulations and guidance material did not anticipate this type of system architecture or...

Prognostics for Electronics Components of Avionics Systems

NASA Technical Reports Server (NTRS)

Celaya, Jose R.; Saha, Bhaskar; Wysocki, Philip F.; Goebel, Kai F.

2009-01-01

Electronics components have and increasingly critical role in avionics systems and for the development of future aircraft systems. Prognostics of such components is becoming a very important research filed as a result of the need to provide aircraft systems with system level health management. This paper reports on a prognostics application for electronics components of avionics systems, in particular, its application to the Isolated Gate Bipolar Transistor (IGBT). The remaining useful life prediction for the IGBT is based on the particle filter framework, leveraging data from an accelerated aging tests on IGBTs. The accelerated aging test provided thermal-electrical overstress by applying thermal cycling to the device. In-situ state monitoring, including measurements of the steady-state voltages and currents, electrical transients, and thermal transients are recorded and used as potential precursors of failure.

Integrated Avionics System (IAS)

NASA Technical Reports Server (NTRS)

Hunter, D. J.

2001-01-01

As spacecraft designs converge toward miniaturization and with the volumetric and mass constraints placed on avionics, programs will continue to advance the 'state of the art' in spacecraft systems development with new challenges to reduce power, mass, and volume. Although new technologies have improved packaging densities, a total system packaging architecture is required that not only reduces spacecraft volume and mass budgets, but increase integration efficiencies, provide modularity and scalability to accommodate multiple missions. With these challenges in mind, a novel packaging approach incorporates solutions that provide broader environmental applications, more flexible system interconnectivity, scalability, and simplified assembly test and integration schemes. This paper will describe the fundamental elements of the Integrated Avionics System (IAS), Horizontally Mounted Cube (HMC) hardware design, system and environmental test results. Additional information is contained in the original extended abstract.

Towards a distributed information architecture for avionics data

NASA Technical Reports Server (NTRS)

Mattmann, Chris; Freeborn, Dana; Crichton, Dan

2003-01-01

Avionics data at the National Aeronautics and Space Administration's (NASA) Jet Propulsion Laboratory (JPL consists of distributed, unmanaged, and heterogeneous information that is hard for flight system design engineers to find and use on new NASA/JPL missions. The development of a systematic approach for capturing, accessing and sharing avionics data critical to the support of NASA/JPL missions and projects is required. We propose a general information architecture for managing the existing distributed avionics data sources and a method for querying and retrieving avionics data using the Object Oriented Data Technology (OODT) framework. OODT uses XML messaging infrastructure that profiles data products and their locations using the ISO-11179 data model for describing data products. Queries against a common data dictionary (which implements the ISO model) are translated to domain dependent source data models, and distributed data products are returned asynchronously through the OODT middleware. Further work will include the ability to 'plug and play' new manufacturer data sources, which are distributed at avionics component manufacturer locations throughout the United States.

Space shuttle low cost/risk avionics study

NASA Technical Reports Server (NTRS)

1971-01-01

All work breakdown structure elements containing any avionics related effort were examined for pricing the life cycle costs. The analytical, testing, and integration efforts are included for the basic onboard avionics and electrical power systems. The design and procurement of special test equipment and maintenance and repair equipment are considered. Program management associated with these efforts is described. Flight test spares and labor and materials associated with the operations and maintenance of the avionics systems throughout the horizontal flight test are examined. It was determined that cost savings can be achieved by using existing hardware, maximizing orbiter-booster commonality, specifying new equipments to MIL quality standards, basing redundancy on cost effective analysis, minimizing software complexity and reducing cross strapping and computer-managed functions, utilizing compilers and floating point computers, and evolving the design as dictated by the horizontal flight test schedules.

Rendezvous strategy impacts on CTV avionics design, system reliability requirements, and available collision avoidance maneuvers

NASA Technical Reports Server (NTRS)

Donovan, William J.; Davis, John E.

1991-01-01

Rockwell International is conducting an ongoing program to develop avionics architectures that provide high intrinsic value while meeting all mission objectives. Studies are being conducted to determine alternative configurations that have low life-cycle cost and minimum development risk, and that minimize launch delays while providing the reliability level to assure a successful mission. This effort is based on four decades of providing ballistic missile avionics to the United States Air Force and has focused on the requirements of the NASA Cargo Transfer Vehicle (CTV) program in 1991. During the development of architectural concepts it became apparent that rendezvous strategy issues have an impact on the architecture of the avionics system. This is in addition to the expected impact on propulsion and electrical power duration, flight profiles, and trajectory during approach.

SMART: The Future of Spaceflight Avionics

NASA Technical Reports Server (NTRS)

Alhorn, Dean C.; Howard, David E.

2010-01-01

A novel avionics approach is necessary to meet the future needs of low cost space and lunar missions that require low mass and low power electronics. The current state of the art for avionics systems are centralized electronic units that perform the required spacecraft functions. These electronic units are usually custom-designed for each application and the approach compels avionics designers to have in-depth system knowledge before design can commence. The overall design, development, test and evaluation (DDT&E) cycle for this conventional approach requires long delivery times for space flight electronics and is very expensive. The Small Multi-purpose Advanced Reconfigurable Technology (SMART) concept is currently being developed to overcome the limitations of traditional avionics design. The SMART concept is based upon two multi-functional modules that can be reconfigured to drive and sense a variety of mechanical and electrical components. The SMART units are key to a distributed avionics architecture whereby the modules are located close to or right at the desired application point. The drive module, SMART-D, receives commands from the main computer and controls the spacecraft mechanisms and devices with localized feedback. The sensor module, SMART-S, is used to sense the environmental sensors and offload local limit checking from the main computer. There are numerous benefits that are realized by implementing the SMART system. Localized sensor signal conditioning electronics reduces signal loss and overall wiring mass. Localized drive electronics increase control bandwidth and minimize time lags for critical functions. These benefits in-turn reduce the main processor overhead functions. Since SMART units are standard flight qualified units, DDT&E is reduced and system design can commence much earlier in the design cycle. Increased production scale lowers individual piece part cost and using standard modules also reduces non-recurring costs. The benefit list continues, but the overall message is already evident: the SMART concept is an evolution in spacecraft avionics. SMART devices have the potential to change the design paradigm for future satellites, spacecraft and even commercial applications.

Use of HCV+ Donors Does Not Affect HCV Clearance With Directly Acting Antiviral Therapy But Shortens the Wait Time to Kidney Transplantation.

PubMed

Sawinski, Deirdre; Patel, Nikunjkumar; Appolo, Brenda; Bloom, Roy

2017-05-01

Hepatitis C virus (HCV) infection is prevalent in the renal transplant population but direct acting antiviral agents (DAA) provide an effective cure of HCV infection without risk of allograft rejection. We report our experience treating 43 renal transplant recipients with 4 different DAA regimens. One hundred percent achieved a sustained viral response by 12 weeks after therapy, and DAA regimens were well tolerated. Recipients transplanted with a HCV+ donor responded equally well to DAA therapy those transplanted with a kidney from an HCV- donor, but recipients of HCV+ organs experienced significantly shorter wait times to transplantation, 485 days (interquartile range, 228-783) versus 969 days (interquartile range, 452-2008; P = 0.02). On this basis, we advocate for a strategy of early posttransplant HCV eradication to facilitate use of HCV+ organs whenever possible. Additional studies are needed to identify the optimal DAA regimen for kidney transplant recipients, accounting for efficacy, timing relative to transplant, posttransplant clinical outcomes, and cost.

Time Triggered Protocol (TTP) for Integrated Modular Avionics

NASA Technical Reports Server (NTRS)

Motzet, Guenter; Gwaltney, David A.; Bauer, Guenther; Jakovljevic, Mirko; Gagea, Leonard

2006-01-01

Traditional avionics computing systems are federated, with each system provided on a number of dedicated hardware units. Federated applications are physically separated from one another and analysis of the systems is undertaken individually. Integrated Modular Avionics (IMA) takes these federated functions and integrates them on a common computing platform in a tightly deterministic distributed real-time network of computing modules in which the different applications can run. IMA supports different levels of criticality in the same computing resource and provides a platform for implementation of fault tolerance through hardware and application redundancy. Modular implementation has distinct benefits in design, testing and system maintainability. This paper covers the requirements for fault tolerant bus systems used to provide reliable communication between IMA computing modules. An overview of the Time Triggered Protocol (TTP) specification and implementation as a reliable solution for IMA systems is presented. Application examples in aircraft avionics and a development system for future space application are covered. The commercially available TTP controller can be also be implemented in an FPGA and the results from implementation studies are covered. Finally future direction for the application of TTP and related development activities are presented.

Hypervelocity impact testing of the Space Station utility distribution system carrier

NASA Technical Reports Server (NTRS)

Lazaroff, Scott

1993-01-01

A two-phase, joint JSC and McDonnell Douglas Aerospace-Huntington Beach hypervelocity impact (HVI) test program was initiated to develop an improved understanding of how meteoroid and orbital debris (M/OD) impacts affect the Space Station Freedom (SSF) avionic and fluid lines routed in the Utility Distribution System (UDS) carrier. This report documents the first phase of the test program which covers nonpowered avionic line segment and pressurized fluid line segment HVI testing. From these tests, a better estimation of avionic line failures is approximately 15 failures per year and could very well drop to around 1 or 2 avionic line failures per year (depending upon the results of the second phase testing of the powered avionic line at White Sands). For the fluid lines, the initial McDonnell Douglas analysis calculated 1 to 2 line failures over a 30 year period. The data obtained from these tests indicate the number of predicted fluid line failures increased slightly to as many as 3 in the first 10 years and up to 15 for the entire 30 year life of SSF.

Description of a dual fail-operational redundant strapdown inertial measurement unit for integrated avionics systems research

NASA Technical Reports Server (NTRS)

Bryant, W. H.; Morrell, F. R.

1981-01-01

Attention is given to a redundant strapdown inertial measurement unit for integrated avionics. The system consists of four two-degree-of-freedom turned rotor gyros and four two-degree-of-freedom accelerometers in a skewed and separable semi-octahedral array. The unit is coupled through instrument electronics to two flight computers which compensate sensor errors. The flight computers are interfaced to the microprocessors and process failure detection, isolation, redundancy management and flight control/navigation algorithms. The unit provides dual fail-operational performance and has data processing frequencies consistent with integrated avionics concepts presently planned.

Advanced Avionics and Processor Systems for Space and Lunar Exploration

NASA Technical Reports Server (NTRS)

Keys, Andrew S.; Adams, James H.; Ray, Robert E.; Johnson, Michael A.; Cressler, John D.

2009-01-01

NASA's newly named Advanced Avionics and Processor Systems (AAPS) project, formerly known as the Radiation Hardened Electronics for Space Environments (RHESE) project, endeavors to mature and develop the avionic and processor technologies required to fulfill NASA's goals for future space and lunar exploration. Over the past year, multiple advancements have been made within each of the individual AAPS technology development tasks that will facilitate the success of the Constellation program elements. This paper provides a brief review of the project's recent technology advancements, discusses their application to Constellation projects, and addresses the project's plans for the coming year.

Automatic Implementation of Ttethernet-Based Time-Triggered Avionics Applications

NASA Astrophysics Data System (ADS)

Gorcitz, Raul Adrian; Carle, Thomas; Lesens, David; Monchaux, David; Potop-Butucaruy, Dumitru; Sorel, Yves

2015-09-01

The design of safety-critical embedded systems such as those used in avionics still involves largely manual phases. But in avionics the definition of standard interfaces embodied in standards such as ARINC 653 or TTEthernet should allow the definition of fully automatic code generation flows that reduce the costs while improving the quality of the generated code, much like compilers have done when replacing manual assembly coding. In this paper, we briefly present such a fully automatic implementation tool, called Lopht, for ARINC653-based time-triggered systems, and then explain how it is currently extended to include support for TTEthernet networks.

Cost-effectiveness of the highly effective direct-acting antivirals in the treatment of chronic hepatitis C in Hong Kong.

PubMed

Lo, Angeline Oi-Shan; Chan, Henry Lik-Yuen; Wong, Vincent Wai-Sun; Wong, Grace Lai-Hung

2017-05-01

In Asia-Pacific where cost is a major concern, peginterferon plus ribavirin (PR) often remain as the standard of care in chronic hepatitis C (CHC) treatment, while the direct-acting antivirals (DAAs) are commonly recommended as retreatment. Newer DAAs can achieve a sustained virological response (SVR) of nearly 100% with pan-genotypic coverage, that is "Highly Effective DAAs." We aimed to investigate the most desirable cost range for the Highly Effective DAAs using Hong Kong as an example. Markov modeling was performed using PR as the reference strategy. The cost-effectiveness of the Highly Effective DAAs was compared with sofosbuvir-PR (first-line and rescue) and boceprevir-PR therapies. A 50-year-old genotype 1b hepatitis C virus (HCV) infected treatment-naïve patient with METAVIR F3 was used as the base case scenario to reflect the commonest HCV genotype in Hong Kong. The use of PR would incur a lifetime cost of US$35,854 and effectiveness of 14.85 quality-adjusted life-year (QALY). Sofosbuvir-PR as first-line treatment was dominated by other regimes. If Sofosbuvir-PR rescue therapy was used, the drug cost of Highly Effective DAAs should be set below US$43,553, with a cost-effectiveness ratio (CER) of US$3035/QALY compared with PR. In regions where Boceprevir-PR was still used as first-line therapy, the desirable drug cost of Highly Effective DAAs would be below US$56,985 to achieve a CER of US$5427/QALY. The most desirable costs of the Highly Effective DAAs would be below US$43,553 if Sofosbuvir-PR rescue therapy is used and below US$56,985 if Boceprevir-PR therapy is used. © 2016 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.

Shift in disparities in hepatitis C treatment from interferon to DAA era: A population-based cohort study.

PubMed

Janjua, N Z; Islam, N; Wong, J; Yoshida, E M; Ramji, A; Samji, H; Butt, Z A; Chong, M; Cook, D; Alvarez, M; Darvishian, M; Tyndall, M; Krajden, M

2017-08-01

We evaluated the shift in the characteristics of people who received interferon-based hepatitis C virus (HCV) treatments and those who received recently introduced direct-acting antivirals (DAAs) in British Columbia (BC), Canada. The BC Hepatitis Testers Cohort includes 1.5 million individuals tested for HCV or HIV, or reported cases of hepatitis B and active tuberculosis in BC from 1990 to 2013 linked to medical visits, hospitalization, cancer, prescription drugs and mortality data. This analysis included all patients who filled at least one prescription for HCV treatment until 31 July 2015. HCV treatments were classified as older interferon-based treatments including pegylated interferon/ribavirin (PegIFN/RBV) with/without boceprevir or telaprevir, DAAs with RBV or PegIFN/RBV, and newer interferon-free DAAs. Of 11 886 people treated for HCV between 2000 and 2015, 1164 (9.8%) received interferon-free DAAs (ledipasvir/sofosbuvir: n=1075; 92.4%), while 452 (3.8%) received a combination of DAAs and RBV or PegIFN/RBV. Compared to those receiving interferon-based treatment, people with HIV co-infection (adjusted odds ratio [aOR]: 2.96, 95% CI: 2.31-3.81), cirrhosis (aOR: 1.77, 95% CI: 1.45-2.15), decompensated cirrhosis (aOR: 1.72, 95% CI: 1.31-2.28), diabetes (aOR: 1.30, 95% CI: 1.10-1.54), a history of injection drug use (aOR: 1.34, 95% CI: 1.09-1.65) and opioid substitution therapy (aOR: 1.30, 95% CI: 1.01-1.67) were more likely to receive interferon-free DAAs. Socio-economically marginalized individuals were significantly less likely (most deprived vs most privileged: aOR: 0.71, 95% CI: 0.58-0.87) to receive DAAs. In conclusion, there is a shift in prescription of new HCV treatments to previously excluded groups (eg HIV-co-infected), although gaps remain for the socio-economically marginalized populations. © 2017 John Wiley & Sons Ltd.

D-amino acids reduce Enterococcus faecalis biofilms in vitro and in the presence of antimicrobials used for root canal treatment.

PubMed

Zilm, Peter S; Butnejski, Victor; Rossi-Fedele, Giampiero; Kidd, Stephen P; Edwards, Suzanne; Vasilev, Krasimir

2017-01-01

Enterococcus faecalis is the most frequent species present in post-treatment disease and plays a significant role in persistent periapical infections following root canal treatment. Its ability to persist in stressful environments is inter alia, due to its ability to form biofilms. The presence of certain D-amino acids (DAAs) has previously been shown to reduce formation of Bacillus subtilis biofilms. The aims of this investigation were to determine if DAAs disrupt biofilms in early and late growth stages for clinical E. faecalis strains and to test their efficacy in disrupting E. faecalis biofilms grown in sub-minimum inhibitory concentrations of commonly used endodontic biocides. From thirty-seven E. faecalis strains, the ten "best" biofilm producers were used to test the ability of a mixture containing D-leucine, D-methionine, D-tyrosine and D-tryptophan to reduce biofilm growth over a period of 24, 72 and 144 hours and when compared to their cognate L-Amino Acids (LAAs). We have previously shown that sub-MIC levels of tetracycline and sodium hypochlorite promotes biofilm growth in clinical strains of E. faecalis. DAAs were therefore tested for their effectiveness to reduce biofilm growth in the presence of sub-minimal concentrations of sodium hypochlorite (NaOCl-0.031%) and Odontocide™ (0.25% w/v), and in the presence of Odontopaste™ (0.25% w/v). DAAs significantly reduced biofilm formation for all strains tested in vitro, while DAAs significantly reduced biofilm formation compared to LAAs. The inhibitory effect of DAAs on biofilm formation was concentration dependent. DAAs were also shown to be effective in reducing E. faecalis biofilms in the presence of Odontopaste™ and sub-MIC levels of NaOCl and Odontocide™. The results suggest that the inclusion of DAAs into current endodontic procedures may reduce E. faecalis biofilms.

Reduction in liver transplant wait-listing in the era of direct-acting antiviral therapy.

PubMed

Flemming, Jennifer A; Kim, W Ray; Brosgart, Carol L; Terrault, Norah A

2017-03-01

Direct-acting antiviral (DAA) therapy, recently approved for patients with decompensated cirrhosis (DC) secondary to hepatitis C virus (HCV), is associated with improved hepatic function. We analyzed trends in liver transplant (LT) wait-listing (WL) to explore potential impact of effective medical therapy on WL registration. This is a cohort study using the Scientific Registry of Transplant Recipients database from 2003 to 2015. A total of 47,591 adults wait-listed for LT from HCV, hepatitis B virus (HBV), and nonalcoholic steatohepatitis (NASH) were identified. LT indication was defined as DC if the Model for End-Stage Liver Disease (MELD) at WL was ≥15 or hepatocellular carcinoma (HCC). Era of listing was divided into interferon (IFN; 2003-2010), protease inhibitor (PI; 2011-2013), and direct-acting antiviral (DAA; 2014-2015). Annual standardized incidence rates of WL were analyzed using Poisson regression. Adjusted incidences of LT WL for DC in HCV patients decreased by 5% in the PI era (P = 0.004) and 32% in the DAA era (P < 0.001) compared to the IFN era. Listing for DC in HBV also decreased in the PI (-17%; P = 0.002) and DAA eras (-24%; P < 0.001). Conversely, WL for DC in NASH increased by 41% in the PI era (P < 0.001) and 81% in the DAA era (P < 0.001). WL for HCC in both the HCV and NASH populations increased in both the PI and DAA eras (P < 0.001 for all) whereas HCC WL in HBV remained stable (P > 0.05 for all). The rate of LT WL for HCV complicated by DC has decreased by over 30% in the era of DAA therapy. Further reductions in WL are anticipated with increased testing, linkage to care, and access to DAA therapy. (Hepatology 2017;65:804-812). © 2016 by the American Association for the Study of Liver Diseases.

Space Shuttle avionics upgrade - Issues and opportunities

NASA Astrophysics Data System (ADS)

Swaim, Richard A.; Wingert, William B.

An overview is conducted of existing Space Shuttle avionics and the possibilities for upgrading the cockpit to reduce costs and increase functionability. The current avionics include five general-purpose computers fitted with multifunction displays, dedicated switches and indicators, and dedicated flight instruments. The operational needs of the Shuttle are reviewed in the light of the avionics and potential upgrades in the form of microprocessors and display systems. The use of better processors can provide hardware support for multitasking and memory management and can reduce the life-cycle cost for software. Some limitations of the current technology are acknowledged including the Shuttle's power budget and structural configuration. A phased infusion of upgraded avionics is proposed that provides a functionally transparent replacement of crew-interface equipment as well as the addition of interface enhancements and the migration of selected functions.

Digital avionics susceptibility to high energy radio frequency fields

NASA Astrophysics Data System (ADS)

Larsen, William E.

Generally, noncritical avionic systems for transport category aircraft have been designed to meet radio frequency (RF) susceptibility requirements set forth in RTCA DO 160B, environmental conditions and test procedures for airborne equipment. Section 20 of this document controls the electromagnetic interference (EMI) hardening for avionics equipment to levels of 1 and 2 V/m. Currently, US equipment manufacturers are designing flight-critical fly-by-wire avionics to a much higher level. The US Federal Aviation Administration (FAA) has requested that the RTCA SC-135 high-energy radio frequency (HERF) working group develop appropriate testing procedures for section 20 of RTCA DO 160B for radiated and conducted susceptibility at the box and systems level. The FAA has also requested the SAE AE4R committee to address installed systems testing, airframe shielding effects and RF environment monitoring. Emitters of interest include radar (ground, ship, and aircraft) commercial broadcast and TV station, mobile communication, and other transmitters that could possibly affect commercial aircraft.

Experimental Studies of Ageing in Electrolytic Capacitors

DTIC Science & Technology

2010-10-01

mechanisms of electronic components critical avionics systems such as the GPS and INAV are of critical importance. Electrolytic capac- itors and...the Inertial Navigation ( INAV ) system, causing the aircraft to fly off course. In this paper, we present the details of our ageing methodology along...directed towards DC-DC convert- ers in Avionics systems. In these systems the power supply drives a Global Positioning System (GPS) and INAV unit, and

Java Architecture for Detect and Avoid Extensibility and Modeling

NASA Technical Reports Server (NTRS)

Santiago, Confesor; Mueller, Eric Richard; Johnson, Marcus A.; Abramson, Michael; Snow, James William

2015-01-01

Unmanned aircraft will equip with a detect-and-avoid (DAA) system that enables them to comply with the requirement to "see and avoid" other aircraft, an important layer in the overall set of procedural, strategic and tactical separation methods designed to prevent mid-air collisions. This paper describes a capability called Java Architecture for Detect and Avoid Extensibility and Modeling (JADEM), developed to prototype and help evaluate various DAA technological requirements by providing a flexible and extensible software platform that models all major detect-and-avoid functions. Figure 1 illustrates JADEM's architecture. The surveillance module can be actual equipment on the unmanned aircraft or simulators that model the process by which sensors on-board detect other aircraft and provide track data to the traffic display. The track evaluation function evaluates each detected aircraft and decides whether to provide an alert to the pilot and its severity. Guidance is a combination of intruder track information, alerting, and avoidance/advisory algorithms behind the tools shown on the traffic display to aid the pilot in determining a maneuver to avoid a loss of well clear. All these functions are designed with a common interface and configurable implementation, which is critical in exploring DAA requirements. To date, JADEM has been utilized in three computer simulations of the National Airspace System, three pilot-in-the-loop experiments using a total of 37 professional UAS pilots, and two flight tests using NASA's Predator-B unmanned aircraft, named Ikhana. The data collected has directly informed the quantitative separation standard for "well clear", safety case, requirements development, and the operational environment for the DAA minimum operational performance standards. This work was performed by the Separation Assurance/Sense and Avoid Interoperability team under NASA's UAS Integration in the NAS project.

Generalized Training Devices for Avionic Systems Maintenance.

ERIC Educational Resources Information Center

Parker, Edward L.

A research study was conducted to determine the feasibility and desirability of developing generalized training equipment for use in avionic systems maintenance training. The study consisted of a group of survey and analytic tasks to provide useful guidance to serve the needs of the Naval Aviation community in future years. The study had four…

EVA Communications Avionics and Informatics

NASA Technical Reports Server (NTRS)

Carek, David Andrew

2005-01-01

The Glenn Research Center is investigating and developing technologies for communications, avionics, and information systems that will significantly enhance extra vehicular activity capabilities to support the Vision for Space Exploration. Several of the ongoing research and development efforts are described within this presentation including system requirements formulation, technology development efforts, trade studies, and operational concept demonstrations.

Scheduling Independent Partitions in Integrated Modular Avionics Systems

PubMed Central

Du, Chenglie; Han, Pengcheng

2016-01-01

Recently the integrated modular avionics (IMA) architecture has been widely adopted by the avionics industry due to its strong partition mechanism. Although the IMA architecture can achieve effective cost reduction and reliability enhancement in the development of avionics systems, it results in a complex allocation and scheduling problem. All partitions in an IMA system should be integrated together according to a proper schedule such that their deadlines will be met even under the worst case situations. In order to help provide a proper scheduling table for all partitions in IMA systems, we study the schedulability of independent partitions on a multiprocessor platform in this paper. We firstly present an exact formulation to calculate the maximum scaling factor and determine whether all partitions are schedulable on a limited number of processors. Then with a Game Theory analogy, we design an approximation algorithm to solve the scheduling problem of partitions, by allowing each partition to optimize its own schedule according to the allocations of the others. Finally, simulation experiments are conducted to show the efficiency and reliability of the approach proposed in terms of time consumption and acceptance ratio. PMID:27942013

General Aviation Avionics Statistics : 1974

DOT National Transportation Integrated Search

1977-08-01

The primary objectives of this study were to (1) provide a framework for viewing the general aviation (GA) aircraft fleet, which would relate airborne avionics equipment to the capability for an aircraft to perform in the National Airspace System, an...

Cloud GIS Based Watershed Management

NASA Astrophysics Data System (ADS)

Bediroğlu, G.; Colak, H. E.

2017-11-01

In this study, we generated a Cloud GIS based watershed management system with using Cloud Computing architecture. Cloud GIS is used as SAAS (Software as a Service) and DAAS (Data as a Service). We applied GIS analysis on cloud in terms of testing SAAS and deployed GIS datasets on cloud in terms of DAAS. We used Hybrid cloud computing model in manner of using ready web based mapping services hosted on cloud (World Topology, Satellite Imageries). We uploaded to system after creating geodatabases including Hydrology (Rivers, Lakes), Soil Maps, Climate Maps, Rain Maps, Geology and Land Use. Watershed of study area has been determined on cloud using ready-hosted topology maps. After uploading all the datasets to systems, we have applied various GIS analysis and queries. Results shown that Cloud GIS technology brings velocity and efficiency for watershed management studies. Besides this, system can be easily implemented for similar land analysis and management studies.

HLLV avionics requirements study and electronic filing system database development

NASA Technical Reports Server (NTRS)

1994-01-01

This final report provides a summary of achievements and activities performed under Contract NAS8-39215. The contract's objective was to explore a new way of delivering, storing, accessing, and archiving study products and information and to define top level system requirements for Heavy Lift Launch Vehicle (HLLV) avionics that incorporate Vehicle Health Management (VHM). This report includes technical objectives, methods, assumptions, recommendations, sample data, and issues as specified by DPD No. 772, DR-3. The report is organized into two major subsections, one specific to each of the two tasks defined in the Statement of Work: the Index Database Task and the HLLV Avionics Requirements Task. The Index Database Task resulted in the selection and modification of a commercial database software tool to contain the data developed during the HLLV Avionics Requirements Task. All summary information is addressed within each task's section.

On-Board Fiber-Optic Network Architectures for Radar and Avionics Signal Distribution

NASA Technical Reports Server (NTRS)

Alam, Mohammad F.; Atiquzzaman, Mohammed; Duncan, Bradley B.; Nguyen, Hung; Kunath, Richard

2000-01-01

Continued progress in both civil and military avionics applications is overstressing the capabilities of existing radio-frequency (RF) communication networks based on coaxial cables on board modem aircrafts. Future avionics systems will require high-bandwidth on- board communication links that are lightweight, immune to electromagnetic interference, and highly reliable. Fiber optic communication technology can meet all these challenges in a cost-effective manner. Recently, digital fiber-optic communication systems, where a fiber-optic network acts like a local area network (LAN) for digital data communications, have become a topic of extensive research and development. Although a fiber-optic system can be designed to transport radio-frequency (RF) signals, the digital fiber-optic systems under development today are not capable of transporting microwave and millimeter-wave RF signals used in radar and avionics systems on board an aircraft. Recent advances in fiber optic technology, especially wavelength division multiplexing (WDM), has opened a number of possibilities for designing on-board fiber optic networks, including all-optical networks for radar and avionics RF signal distribution. In this paper, we investigate a number of different novel approaches for fiber-optic transmission of on-board VHF and UHF RF signals using commercial off-the-shelf (COTS) components. The relative merits and demerits of each architecture are discussed, and the suitability of each architecture for particular applications is pointed out. All-optical approaches show better performance than other traditional approaches in terms of signal-to-noise ratio, power consumption, and weight requirements.

Digital Systems Validation Handbook. Volume 2. Chapter 18. Avionic Data Bus Integration Technology

DTIC Science & Technology

1993-11-01

interaction between a digital data bus and an avionic system. Very Large Scale Integration (VLSI) ICs and multiversion software, which make up digital...1984, the Sperry Corporation developed a fault tolerant system which employed multiversion programming, voting, and monitoring for error detection and...formulate all the significant behavior of a system. MULTIVERSION PROGRAMMING. N-version programming. N-VERSION PROGRAMMING. The independent coding of a

Transitioning to the direct anterior approach in total hip arthroplasty. Is it a true muscle sparing approach when performed by a low volume hip replacement surgeon?

PubMed

Nistor, Dan-Viorel; Caterev, Sergiu; Bolboacă, Sorana-Daniela; Cosma, Dan; Lucaciu, Dan Osvald Gheorghe; Todor, Adrian

2017-11-01

We conducted this study to establish if the transition from a lateral approach (LA) to the direct anterior approach (DAA) for a low volume hip arthroplasty surgeon during the steep learning curve can be performed maintaining the muscle sparing approach of the DAA without increasing the complication rates. In this controlled, prospective, randomized clinical study we investigated 70 patients (35 DAA, 35 LA) with similar demographics that underwent a total hip arthroplasty. Assessment of the two approaches consisted of determining the invasiveness through serum markers for muscle damage (i.e. myoglobin, creatine kinase and lactate dehydrogenase), the operative parameters such as post-operative pain and rescue medication consumption, the component positioning and complication rates. Post-operative myoglobin levels were higher (p < 0.001) in the LA group (326.42 ± 84.91 ng/mL) as compared to the DAA group (242.80 ± 71.03 ng/mL), but with no differences regarding other biomarkers for muscle damage. Pain levels were overall lower in the DAA group, with a statistical and clinical difference during surgery day (p < 0.001) associated with lower (p < 0.001) rescue medication consumption (median 1 (1; 3) mg morphine vs. 3 (2; 4) mg morphine). Most patients in the LA group reported chronic post-operative pain throughout all three evaluated months, while the majority of patients in the DAA group reported no pain after week six. Component positioning did not differ significantly between groups and neither did complication rates. The DAA can be transitioned from the LA safely, without higher complication rates while maintaining its muscle spearing advantages when performed by a low volume hip arthroplasty surgeon.

Safety of Direct-Acting Antiviral Therapy Regarding Renal Function in Post-Liver Transplant Patients Infected with Hepatitis C Virus and a 100% 12-Week Sustained Virologic Response-A Single-Center Study.

PubMed

Peschel, G; Moleda, L; Baier, L; Selgrad, M; Schmid, S; Scherer, M N; Müller, M; Weigand, K

2018-06-01

Patients after liver transplantation (LT) with hepatitis C virus (HCV) infection often suffer from renal or hepatic impairment. Treating patients after LT with direct-acting antivirals (DAA) might result in decreasing renal function due to interaction of DAA and immunosuppressive therapy. In this single-center study we analyzed clinical parameters of 18 HCV-infected patients treated with DAA therapy after LT. The primary end points were change of renal function (glomerular filtration rate) and sustained virologic response 12 weeks after therapy (SVR12). For secondary end points, we investigated the influence of DAA therapy on transaminases, bilirubin, international normalized ratio, noninvasive fibrosis measurement, and Model for End-Stage Liver Disease (MELD) score. Five out of 18 patients treated with DAA suffered from renal impairment stage 2, and 7 patients of renal impairment stage 3. Renal function at SVR12 was not influenced by preexisting renal impairment (P > .5), type of immunosuppressant (P > .5), or type of DAA regimen (P > .5). All patients reached SVR12. The levels of transaminases and bilirubin declined rapidly, as expected. Ten out of 18 patients already suffered from cirrhosis or liver fibrosis >F3 according to noninvasive measurement before initiation of treatment. Single-point acoustic radiation force impulse imaging improved in 9 patients (P = .012). In 7 patients, MELD score improved owing to the decrease of bilirubin levels. In 6 patients it worsened. DAA therapy in LT patients was effective and safe in this single-center real-life cohort. Renal function was not influenced by the administered drug combinations, even in patients with preexisting renal impairment. Copyright © 2018. Published by Elsevier Inc.

Hepatocellular carcinoma risk assessment by the measurement of liver stiffness variations in HCV cirrhotics treated with direct acting antivirals.

PubMed

Ravaioli, Federico; Conti, Fabio; Brillanti, Stefano; Andreone, Pietro; Mazzella, Giuseppe; Buonfiglioli, Federica; Serio, Ilaria; Verrucchi, Gabriella; Bacchi Reggiani, Maria Letizia; Colli, Agostino; Marasco, Giovanni; Colecchia, Antonio; Festi, Davide

2018-06-01

Direct-acting antivirals (DAA) are an effective treatment for hepatitis C virus infection. However, sustained virologic response (SVR) after DAA treatment does not seem to reduce the risk of hepatocellular carcinoma (HCC) development in these patients. Liver stiffness measurement (LSM) may predict the risk of developing HCC in liver cirrhosis patients. The aim of our study was to evaluate the role of LSM variation as predictor of HCC development in patients treated with DAA. In 139 HCV-related cirrhotic patients, LSM and laboratory tests were carried out at baseline (BL) and at the end of DAA treatment (EOT). Patients were followed for at least 6 months after the EOT. LSM reduction was expressed as Delta LS (∆LS). Cox regression analysis was used to identify prognostic factors for HCC development after DAA. Median LSM values were significantly reduced from BL to EOT (from 18.6 to 13.8 kPa; p < 0.001). The median ∆LS was -26.7% (IQR: -38.4% -13.6%). During a median follow-up of 15 months after DAA treatment, 20 (14.4%) patients developed HCC. Significant LSM reduction was observed both in patients who developed HCC and in those who did not, but this was significantly lower in the patients who developed HCC (-18.0% vs -28.9% p = 0.005). At multivariate analysis, ∆LS lower than -30%, Child-Turcotte-Pugh-B and history of HCC were independently associated with HCC development. Our results indicate that ∆LS is a useful non-invasive marker for predicting HCC development after DAA treatment. Copyright © 2018 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

An overview of autonomous rendezvous and docking system technology development

NASA Astrophysics Data System (ADS)

Nelson, Kurt D.

The Centaur upper stage was selected for an airborne avionics modernization program. The parts used in the existing avionics units were obsolete. Continued use of existing hardware would require substantial redesign, yet would result in the use of outdated hardware. Out of date processes, with very expensive and labor intensive technologies, were being used for manufacturing. The Atlas/Centaur avionics were to be procured at a fairly high rate that demanded the use of modern components. The new avionics also reduce size, weight, power, and parts count with a dramatic improvement in reliability. Finally, the cost leverage derived from upgrading the avionics as opposed to any other subsystem for the existing Atlas/Centaur was a very large consideration in the upgrade decision. The upgrade program is a multiyear effort that began in 1989. It includes telemetry, guidance and navigation, control electronics, thrust vector control, and redundancy levels.

Retreatment of patients with treatment failure of direct-acting antivirals: Focus on hepatitis C virus genotype 1b.

PubMed

Kanda, Tatsuo; Nirei, Kazushige; Matsumoto, Naoki; Higuchi, Teruhisa; Nakamura, Hitomi; Yamagami, Hiroaki; Matsuoka, Shunichi; Moriyama, Mitsuhiko

2017-12-14

The recent development of direct-acting antiviral agents (DAAs) against hepatitis C virus (HCV) infection could lead to higher sustained virological response (SVR) rates, with shorter treatment durations and fewer adverse events compared with regimens that include interferon. However, a relatively small proportion of patients cannot achieve SVR in the first treatment, including DAAs with or without peginterferon and/or ribavirin. Although retreatment with a combination of DAAs should be conducted for these patients, it is more difficult to achieve SVR when retreating these patients because of resistance-associated substitutions (RASs) or treatment-emergent substitutions. In Japan, HCV genotype 1b (GT1b) is founded in 70% of HCV-infected individuals. In this minireview, we summarize the retreatment regimens and their SVR rates for HCV GT1b. It is important to avoid drugs that target the regions targeted by initial drugs, but next-generation combinations of DAAs, such as sofosbuvir/velpatasvir/voxilaprevir for 12 wk or glecaprevir/pibrentasvir for 12 wk, are proposed to be potential solution for the HCV GT1b-infected patients with treatment failure, mainly on a basis of targeting distinctive regions. Clinicians should follow the new information and resources for DAAs and select the proper combination of DAAs for the retreatment of HCV GT1b-infected patients with treatment failure.

Uptake and conversion of D-amino acids in Arabidopsis thaliana.

PubMed

Gördes, Dirk; Kolukisaoglu, Üner; Thurow, Kerstin

2011-02-01

The D-enantiomers of proteinogenic amino acids fulfill essential functions in bacteria, fungi and animals. Just in the plant kingdom, the metabolism and role of D-amino acids (D-AAs) still remains unclear, although plants have to cope with significant amounts of these compounds from microbial decay in the rhizosphere. To fill this gap of knowledge, we tested the inhibitory effects of D-AAs on plant growth and established a method to quantitate 16 out of 19 proteinogenic amino acids and their D-enantiomers in plant tissue extracts. Therefore, the amino acids in the extracts were derivatized with Marfey's reagent and separated by HPLC-MS. We used two ecotypes (Col-0 and C24) and a mutant (lht1) of the model plant Arabidopsis thaliana to determine the influence and fate of exogenously applied D-AAs. All of them were found in high concentrations in the plant extracts after application, even in lht1, which points to additional transporters facilitating the import of D-AAs. The addition of particular amino acids (D-Trp, D-Phe, D-Met and D-His) led to the accumulation of the corresponding L-amino acid. In almost all cases, the application of a D-AA resulted in the accumulation of D-Ala and D-Glu. The presented results indicate that soil borne D-AAs can actively be taken up and metabolized via central metabolic routes.

The Impact of Integrated Maneuver Guidance Information on UAS Pilots Performing the Detect and Avoid Task

NASA Technical Reports Server (NTRS)

Rorie, Conrad; Fern, Lisa

2015-01-01

The integrated human-in-the-loop (iHITL) simulation examined the effect of four different Detect-and-Avoid (DAA) display concepts on unmanned aircraft system (UAS) pilots' ability to maintain safe separation. The displays varied in the type and amount of guidance they provided to pilots. The study's background and methodology are discussed, followed by the 'measured response' data (i.e., pilots' end-to-end response time in reacting to traffic alerts on their DAA display). Results indicate that display type had a significant impact on how long pilot's spent interacting with the interface (i.e., edit times).

Methode de conception dirigee par les modeles pour les systemes avioniques modulaires integres basee sur une approche de cosimulation

NASA Astrophysics Data System (ADS)

Bao, Lin

In the aerospace industry, with the development of avionic systems becomes more and more complex, the integrated modular avionics (IMA) architecture was proposed to replace its predecessor - the federated architecture, in order to reduce the weight, power consumption and the dimension of the avionics equipment. The research work presented in this thesis, which is considered as a part of the research project AVIO509, aims to propose to the aviation industry a set of time-effective and cost-effective solutions for the development and the functional validation of IMA systems. The proposed methodologies mainly focus on two design flows that are based on: 1) the concept of model-driven engineering design and 2) a cosimulation platform. In the first design flow, the modeling language AADL is used to describe the IMA architecture. The environment OCARINA, a code generator initially designed for POK, was modified so that it can generate avionic applications from an AADL model for the simulator SIMA (an IMA simulator compliant to the ARINC653 standards). In the second design flow, Simulink is used to simulate the external world of IMA module thanks to the availability of avionic library that can offer lots of avionics sensors and actuators, and as well as its effectiveness in creating the Simulink models. The cosimulation platform is composed of two simulators: Simulink for the simulation of peripherals and SIMA for the simulation of IMA module, the latter is considered as an ideal alternative for the super expensive commercial development environment. In order to have a good portability, a SIMA partition is reserved as the role of " adapter " to synchronize the communication between these two simulators via the TCP/IP protocol. When the avionics applications are ported to the implementation platform (such as PikeOS) after the simulation, there is only the " adapter " to be modified because the internal communication and the system configuration are the same. An avionics application was developed as a case study, in order to demonstrate the validation of the proposed design flows. The research presented in this paper is a continuation of project of the AVIO509 research team, and parallelly may be extended in the future work.

Digital Avionics

NASA Technical Reports Server (NTRS)

Koelbl, Terry G.; Ponchak, Denise; Lamarche, Teresa

2003-01-01

Digital Avionics activities played an important role in the advancements made in civil aviation, military systems, and space applications. This document profiles advances made in each of these areas by the aerospace industry, NASA centers, and the U.S. military. Emerging communication technologies covered in this document include Internet connectivity onboard aircraft, wireless broadband communication for aircraft, and a mobile router for aircraft to communicate in multiple communication networks over the course of a flight. Military technologies covered in this document include avionics for unmanned combat air vehicles and microsatellites, and head-up displays. Other technologies covered in this document include an electronic flight bag for the Boeing 777, and surveillance systems for managing airport operations.

A Definition of STS Accommodations for Attached Payloads

NASA Technical Reports Server (NTRS)

Echols, F. L.; Broome, P. A.

1983-01-01

An input to a study conducted to define a set of carrier avionics for supporting large structures experiments attached to the Space Shuttle Orbiter is reported. The "baseline" Orbier interface used in developing the avionics concept for the Space Technology Experiments Platform, STEP, which Langley Research Center has proposed for supporting experiments of this sort is defined. Primarily, flight operations capabilities and considerations and the avionics systems capabilities that are available to a payload as a "mixed cargo" user of the Space Transportation System are addressed. Ground operations for payload integration at Kennedy Space Center, and ground operations for payload support during the mission are also discussed.

An overview of the F-117A avionics flight test program

DOE Office of Scientific and Technical Information (OSTI.GOV)

Silz, R.

1992-02-01

This paper is an overview of the history of the F-117A avionics flight test program. System design concepts and equipment selections are explored followed by a review of full scale development and full capability development testing. Flight testing the Weapon System Computational Subsystem upgrade and the Offensive Combat Improvement Program are reviewed. Current flight test programs and future system updates are highlighted.

The MGS Avionics System Architecture: Exploring the Limits of Inheritance

NASA Technical Reports Server (NTRS)

Bunker, R.

1994-01-01

Mars Global Surveyor (MGS) avionics system architecture comprises much of the electronics on board the spacecraft: electrical power, attitude and articulation control, command and data handling, telecommunications, and flight software. Schedule and cost constraints dictated a mix of new and inherited designs, especially hardware upgrades based on findings of the Mars Observer failure review boards.

MECHANIZATION STUDY OF THE TECHNICAL LIBRARY U.S. NAVAL AVIONICS FACILITY, INDIANAPOLIS, INDIANA.

ERIC Educational Resources Information Center

KERSHAW, G.A.; AND OTHERS

THE NAVAL AVIONICS FACILITY, INDIANAPOLIS (NAFI) TECHNICAL LIBRARY IS PLANNING A MECHANIZED SYSTEM TO PRODUCE A PERMUTED INDEX OF PERTINENT PERIODICAL REFERENCES AND PROCEEDINGS, WITH BOOKS AND DOCUMENTS TO BE ADDED LATER. INPUT TO THE SYSTEM IS PUNCHED PAPER TAPE PREPARED FROM THE SOURCE MATERIAL, AND THE PRIMARY PROGRAM IS A "CANNED"…

Hardware Implementation of COTS Avionics System on Unmanned Aerial Vehicle Platforms

NASA Technical Reports Server (NTRS)

Yeh, Yoo-Hsiu; Kumar, Parth; Ishihara, Abraham; Ippolito, Corey

2010-01-01

Unmanned Aerial Vehicles (UAVs) can serve as low cost and low risk platforms for flight testing in Aeronautics research. The NASA Exploration Aerial Vehicle (EAV) and Experimental Sensor-Controlled Aerial Vehicle (X-SCAV) UAVs were developed in support of control systems research at NASA Ames Research Center. The avionics hardware for both systems has been redesigned and updated, and the structure of the EAV has been further strengthened. Preliminary tests show the avionics operate properly in the new configuration. A linear model for the EAV also was estimated from flight data, and was verified in simulation. These modifications and results prepare the EAV and X-SCAV to be used in a wide variety of flight research projects.

Management of hepatitis C infection in the era of direct-acting antiviral therapy

NASA Astrophysics Data System (ADS)

Zain, L. H.; Sungkar, T.

2018-03-01

Hepatitis C viral infection globally affects millions of people and commonly results in debilitating complications and mortality. Initial mainstay therapy consisted of pegylated interferon α (pegIFNα) with additional ribavirin that showed unsatisfactory cure rate, common side effects and complicated dosing, contributing to high discontinuation rate. Over the last few years, newer antivirals have been extensively studied, that are Direct-Acting Antivirals (DAAs). Specifically targeting viral protein mainly during replication phase, DAAs showed greater cure rate (commonly measured as sustained virologic response), improved safety profile and shorter treatment duration compared to traditional interferon-ribavirin therapy. Current guidelines have also included Interferon-free, often ribavirin-free, DAAs combinations that suggest promising outcomes. The current review highlights development of rapidly growing hepatitis C treatment including DAAs recommendations.

The Digital Ageing Atlas: integrating the diversity of age-related changes into a unified resource.

PubMed

Craig, Thomas; Smelick, Chris; Tacutu, Robi; Wuttke, Daniel; Wood, Shona H; Stanley, Henry; Janssens, Georges; Savitskaya, Ekaterina; Moskalev, Alexey; Arking, Robert; de Magalhães, João Pedro

2015-01-01

Multiple studies characterizing the human ageing phenotype have been conducted for decades. However, there is no centralized resource in which data on multiple age-related changes are collated. Currently, researchers must consult several sources, including primary publications, in order to obtain age-related data at various levels. To address this and facilitate integrative, system-level studies of ageing we developed the Digital Ageing Atlas (DAA). The DAA is a one-stop collection of human age-related data covering different biological levels (molecular, cellular, physiological, psychological and pathological) that is freely available online (http://ageing-map.org/). Each of the >3000 age-related changes is associated with a specific tissue and has its own page displaying a variety of information, including at least one reference. Age-related changes can also be linked to each other in hierarchical trees to represent different types of relationships. In addition, we developed an intuitive and user-friendly interface that allows searching, browsing and retrieving information in an integrated and interactive fashion. Overall, the DAA offers a new approach to systemizing ageing resources, providing a manually-curated and readily accessible source of age-related changes. © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

UAS Well Clear Recovery Against Non-Cooperative Intruders Using Vertical Maneuvers

NASA Technical Reports Server (NTRS)

Cone, Andrew; Thipphavong, David; Lee, Seung Man; Santiago, Confesor

2017-01-01

This paper documents a study that drove the development of a mathematical expression in the minimum operational performance standards (MOPS) of detect-and-avoid (DAA) systems for unmanned aircraft systems (UAS). This equation describes the conditions under which vertical maneuver guidance could be provided during recovery of well clear separation with a non-cooperative VFR aircraft in addition to horizontal maneuver guidance. Although suppressing vertical maneuver guidance in these situations increased the minimum horizontal separation from 500 to 800 feet, the maximum severity of loss of well clear increased in about 35 of the encounters compared to when a vertical maneuver was preferred and allowed. Additionally, analysis of individual cases led to the identification of a class of encounter where vertical rate error had a large effect on horizontal maneuvers due to the difficulty of making the correct left-right turn decision: crossing conflict with intruder changing altitude. These results supported allowing vertical maneuvers when UAS vertical performance exceeds the relative vertical position and velocity accuracy of the DAA tracker given the current velocity of the UAS and the relative vertical position and velocity estimated by the DAA tracker. Looking ahead, these results indicate a need to improve guidance algorithms by utilizing maneuver stability and near mid-air collision risk when determining maneuver guidance to regain well clear separation.

Impact of DAAs on liver transplantation: major effects on the evolution of indications and results. An ELITA study based on the ELTR registry.

PubMed

Belli, Luca Saverio; Perricone, Giovanni; Adam, Rene; Cortesi, Paolo A; Strazzabosco, Mario; Facchetti, Rita; Karam, Vincent; Salizzoni, Mauro; Andujar, Rafael Lopez; Fondevila, Costantino; De Simone, Paolo; Morelli, Cristina; Fabregat-Prous, Joan; Samuel, Didier; Agarwaal, Kosh; Gonzales, Enrique Moreno; Charco, Ramon; Zieniewicz, Krzysztof; De Carlis, Luciano; Duvoux, Christophe

2018-06-22

Direct-acting antiviral drugs (DAAs) have dramatically improved the outcome of patients with hepatitis C virus (HCV) infection including those with decompensated cirrhosis (DC). We analysed the evolution of indications and results of liver transplantation (LT) in the past 10 years in Europe, focusing on the changes induced by the advent of the DAA. This is a cohort study based on data from the European Liver Transplant Registry (ELTR). Data of adult LTs performed between January 2007 to June 2017 for HCV, hepatitis B virus (HBV), alcohol (ETOH) and non-alcoholic steatohepatitis (NASH) was analysed. The period was divided into different eras: interferon (IFN/RBV; 2007-2010), protease inhibitor (PI; 2011-2013) and second generation DAA (DAA; 2014-June 2017). Out of a total number of 60,527 LTs, 36,382 were performed in patients with HCV, HBV, ETOH and NASH. The percentage of LTs due to HCV-related liver disease varied significantly over time (p<0.0001), decreasing from 22.8% in IFN/RBV era to 17.4% in the DAA era, while those performed for NASH increased significantly (p<0.0001). In the DAA era, the percentage of LTs for HCV decreased significantly (p<0.0001) from 21.1% (first semester 2014) to 10.6% (first semester 2017). This decline was more evident in patients with DC (HCV-DC, -58.0%) than in those with HCC associated to HCV (HCV-HCC, -41.2%). Conversely, three-year survival of LT recipients with HCV related liver disease improved from 65.1% in the IFN/RBV era to 76.9% in the DAA era, being currently comparable to the survival of recipients with HBV infection (p=0.3807). In Europe, the number of LTs due to HCV infection is rapidly declining for both HCV-DC and HCV-HCC indications and post-LT survival has dramatically improved over the last three years. This is the first comprehensive study of the overall impact of DAA treatment for HCV on liver transplantation in Europe. After the advent of DAAs in 2014, a dramatic decline in the number of LT performed both in patients with decompensated cirrhosis due to HCV, minus 60%, and in those with HCC associated to HCV, minus 41%, was observed. Furthermore, this is the first large scale study demonstrating that the survival of LT recipients with HCV related liver disease has dramatically improved over the last three years, being currently comparable to the survival of recipients with HBV infection. A positive result from decreased need of LT for HCV related indications is greater availability of livers, at least 6oo every year, which may be allocated to indications other than HCV. Copyright © 2018. Published by Elsevier B.V.

Space Transportation Avionics Technology Symposium. Volume 1: Executive summary

NASA Technical Reports Server (NTRS)

1990-01-01

The focus of the symposium was to examine existing and planned avionics technology processes and products and to recommend necessary changes for strengthening priorities and program emphases. Innovative changes in avionics technology development and design processes, identified during the symposium, are needed to support the increasingly complex, multi-vehicle, integrated, autonomous space-based systems. Key technology advances make such a major initiative viable at this time: digital processing capabilities, integrated on-board test/checkout methods, easily reconfigurable laboratories, and software design and production techniques.

Space Transportation Avionics Technology Symposium. Volume 2: Conference Proceedings

NASA Technical Reports Server (NTRS)

1990-01-01

The focus of the symposium was to examine existing and planned avionics technology processes and products and to recommend necessary changes for strengthening priorities and program emphases. Innovative changes in avionics technology development and design processes are needed to support the increasingly complex, multi-vehicle, integrated, autonomous space-based systems. Key technology advances make such a major initiative viable at this time: digital processing capabilities, integrated on-board test/checkout methods, easily reconfigurable laboratories, and software design and production techniques.

Avionics Reliability, Its Techniques and Related Disciplines.

DTIC Science & Technology

1979-10-01

USAF F-16s. C.J.P.Haynes, UK You said that if one of the 5 nations consumes more than its fair share of the combined spares pool then the item manager ... MANAGEMENT OF THE AVIONIC SYSTEM OF A MILITARY STRIKE AIRCRAFT by A.P.White and J.D.Pavier 29 SESSION IV - SOFTWARE RELIABILITY’ INTRODUCTION TO...ASPECT by D.J.Harris 37 SESSION V - AVIONICS LOGISTICS SUPPORT ASPECTS INTEGRATED LOGISTICS SUPPORT ADDS ANOTHER DIMENSION TO MATRIX MANAGEMENT by

Avionics Architectures for Exploration: Wireless Technologies and Human Spaceflight

NASA Technical Reports Server (NTRS)

Goforth, Montgomery B.; Ratliff, James E.; Barton, Richard J.; Wagner, Raymond S.; Lansdowne, Chatwin

2014-01-01

The authors describe ongoing efforts by the Avionics Architectures for Exploration (AAE) project chartered by NASA's Advanced Exploration Systems (AES) Program to evaluate new avionics architectures and technologies, provide objective comparisons of them, and mature selected technologies for flight and for use by other AES projects. The AAE project team includes members from most NASA centers and from industry. This paper provides an overview of recent AAE efforts, with particular emphasis on the wireless technologies being evaluated under AES to support human spaceflight.

Examining Hepatitis, A and B Vaccination, and HBV Reactivation Monitoring During Direct-Acting Antiviral Therapy for Hepatitis C.

PubMed

Davison, John; O'Shea, Amy; Waterbury, Nancee; Villalvazo, Yolanda

2018-05-30

The objective of this study was to examine Hepatitis A (HAV) and Hepatitis B (HBV) screening, and the risk of HBV reactivation during Hepatitis C (HCV) therapy with direct-acting antivirals (DAAs). A retrospective chart review was performed of patients treated with second generation DAA therapy from January 2014 to September 2016 at the Iowa City VA Healthcare System. In total 409 patients initiated HCV treatment, 308 (75%) and 241 (59%) were HAV and HBV vaccine eligible, respectively. Among those, 24 (8%) received a HAV vaccine, while only 20 (8%) received a HBV vaccine. Of these, 7 patients initiating an immunization in the clinic had record of completing the series. Further, 101 patients had a reactive Hepatitis B core Antibody indicating previous HBV infection, and 3 of these were tested for HBV reactivation during HCV therapy. Overall, the assessment found low rates of HAV and HBV vaccine administration, indicating missed opportunities for preventative care during HCV therapy. With the known risk of HBV reactivation with DAAs, the need for HAV and HBV screening is essential.

Liquid Rocket Booster (LRB) for the Space Transportion System (STS) systems study. Appendix D: Trade study summary for the liquid rocket booster

NASA Technical Reports Server (NTRS)

1989-01-01

Trade studies plans for a number of elements in the Liquid Rocket Booster (LRB) component of the Space Transportation System (STS) are given in viewgraph form. Some of the elements covered include: avionics/flight control; avionics architecture; thrust vector control studies; engine control electronics; liquid rocket propellants; propellant pressurization systems; recoverable spacecraft; cryogenic tanks; and spacecraft construction materials.

An autonomous rendezvous and docking system using cruise missile technology

NASA Technical Reports Server (NTRS)

Jones, ED; Nicholson, Bruce

1991-01-01

In November 1990 General Dynamics demonstrated an AR&D system for members of the Strategic Avionics Technology Working Group. This simulation utilized prototype hardware derived from the Cruise Missile and Centaur avionics systems. The object of this proof of concept demonstration was to show that all the accuracy, reliability, and operational requirements established for a spacecraft to dock with Space Station Freedom could be met by the proposed AR&D system.

Strategic bombers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1992-07-01

This paper reports on the questions: should Congress provide more funds for the Air Force's current plan---the CORE program---to upgrade the B-1B defense avionics system In GAO's view, more testing of the system is not necessary to determine whether to implement the CORE program. Flight testing has shown that the CORE modifications would provide similar operational capabilities to, and offer some survivability improvements over, the existing defense avionics system. The only reason for additional testing would be to prove that some problems with the maintenance diagnostic system has been resolved. Initial testing revealed that while some improvements were achieved, usermore » requirements were not met for such things as low false alarm rates and cannot duplicate rates. Even if the maintenance diagnostic capabilities were fully demonstrated, however, the CORE system should not be implemented until it is known whether the defense avionics system design can support the B-1B's new role as a conventional bomber.« less

Identification des parametres du moteur de l'avion Cessna Citation X pour la phase de croisiere a partir des tests en vol et a base des reseaux de neurones =

NASA Astrophysics Data System (ADS)

Zaag, Mahdi

La disponibilite des modeles precis des avions est parmi les elements cles permettant d'assurer leurs ameliorations. Ces modeles servent a ameliorer les commandes de vol et de concevoir de nouveaux systemes aerodynamiques pour la conception des ailes deformables des avions. Ce projet consiste a concevoir un systeme d'identification de certains parametres du modele du moteur de l'avion d'affaires americain Cessna Citation X pour la phase de croisiere a partir des essais en vol. Ces essais ont ete effectues sur le simulateur de vol concu et fabrique par CAE Inc. qui possede le niveau D de la dynamique de vol. En effet, le niveau D est le plus haut niveau de precision donne par l'autorite federale de reglementation FAA de l'aviation civile aux Etats-Unis. Une methodologie basee sur les reseaux de neurones optimises a l'aide d'un algorithme intitule le "grand deluge etendu" est utilisee dans la conception de ce systeme d'identification. Plusieurs tests de vol pour differentes altitudes et differents nombres de Mach ont ete realises afin de s'en servir comme bases de donnees pour l'apprentissage des reseaux de neurones. La validation de ce modele a ete realisee a l'aide des donnees du simulateur. Malgre la nonlinearite et la complexite du systeme, les parametres du moteur ont ete tres bien predits pour une enveloppe de vol determinee. Ce modele estime pourrait etre utilise pour des analyses de fonctionnement du moteur et pourrait assurer le controle de l'avion pendant cette phase de croisiere. L'identification des parametres du moteur pourrait etre realisee aussi pour les autres phases de montee et de descente afin d'obtenir son modele complet pour toute l'enveloppe du vol de l'avion Cessna Citation X (montee, croisiere, descente). Cette methode employee dans ce travail pourrait aussi etre efficace pour realiser un modele pour l'identification des coefficients aerodynamiques du meme avion a partir toujours des essais en vol. None None None

Validation of Digital Systems in Avionics and Flight Control Applications Handbook. Volume 1.

DTIC Science & Technology

1983-07-01

will also be available to Airways Facilities, Systems Research and Development Service, Air Traffic Control Service, and Flight Standards elements...2114, March 12-14, 1979. 3. Validation Methods Research for Fault-Tolerant Avionics and Control Systems-- *r Working Group Meeting II, NASA...command generation with the multiple methods becoming avail- able for closure of the outer control loop necessitates research on alternative integration

Avionics upgrade strategies for the Space Shuttle and derivatives

NASA Astrophysics Data System (ADS)

Swaim, Richard A.; Wingert, William B.

Some approaches aimed at providing a low-cost, low-risk strategy to upgrade the shuttle onboard avionics are described. These approaches allow migration to a shuttle-derived vehicle and provide commonality with Space Station Freedom avionics to the extent practical. Some goals of the Shuttle cockpit upgrade include: offloading of the main computers by distributing avionics display functions, reducing crew workload, reducing maintenance cost, and providing display reconfigurability and context sensitivity. These goals are being met by using a combination of off-the-shelf and newly developed software and hardware. The software will be developed using Ada. Advanced active matrix liquid crystal displays are being used to meet the tight space, weight, and power consumption requirements. Eventually, it is desirable to upgrade the current shuttle data processing system with a system that has more in common with the Space Station data management system. This will involve not only changes in Space Shuttle onboard hardware, but changes in the software. Possible approaches to maximizing the use of the existing software base while taking advantage of new language capabilities are discussed.

Avionic Data Bus Integration Technology

DTIC Science & Technology

1991-12-01

address the hardware-software interaction between a digital data bus and an avionic system. Very Large Scale Integration (VLSI) ICs and multiversion ...the SCP. In 1984, the Sperry Corporation developed a fault tolerant system which employed multiversion programming, voting, and monitoring for error... MULTIVERSION PROGRAMMING. N-version programming. 226 N-VERSION PROGRAMMING. The independent coding of a number, N, of redundant computer programs that

Digital Avionics Information System (DAIS): Reliability and Maintainability Model Users Guide. Final Report, May 1975-July 1977.

ERIC Educational Resources Information Center

Czuchry, Andrew J.; And Others

This report provides a complete guide to the stand alone mode operation of the reliability and maintenance (R&M) model, which was developed to facilitate the performance of design versus cost trade-offs within the digital avionics information system (DAIS) acquisition process. The features and structure of the model, its input data…

Advanced Avionic Systems for Multimission Applications. Volume I.

DTIC Science & Technology

1982-10-01

technical report are theoretical and in no way reflect Air Fortp-nwnpid qnftwRrp png ramc 19. KEY WORDS (Continue on reveree aide It neceeary and Identify...addressed (1) the Development & Evaluation of Advanced Digital Avionics System Architectures and (2) the Development of a Single Processor Synchronous...29 4.3.2 Memory Technologies . . . . . . . . . . . . . . . . . 30 4.3.3 BIU Technology . . . . . . . . . . . . . . . . . . . 33

Treatment of chronic hepatitis C with direct-acting antivirals: The role of resistance

PubMed Central

Jiménez-Pérez, Miguel; González-Grande, Rocío; España Contreras, Pilar; Pinazo Martínez, Isabel; de la Cruz Lombardo, Jesús; Olmedo Martín, Raúl

2016-01-01

The use of direct-acting antivirals (DAAs) to treat chronic hepatitis C has resulted in a significant increase in rates of sustained viral response (around 90%-95%) as compared with the standard treatment of peginterferon/ribavirin. Despite this, however, the rates of therapeutic failure in daily clinical practice range from 10%-15%. Most of these cases are due to the presence of resistant viral variants, resulting from mutations produced by substitutions of amino acids in the viral target protein that reduce viral sensitivity to DAAs, thus limiting the efficacy of these drugs. The high genetic diversity of hepatitis C virus has resulted in the existence of resistance-associated variants (RAVs), sometimes even before starting treatment with DAAs, though generally at low levels. These pre-existing RAVs do not appear to impact on the sustained viral response, whereas those that appear after DAA therapy could well be determinant in virological failure with future treatments. As well as the presence of RAVs, virological failure to treatment with DAAs is generally associated with other factors related with a poor response, such as the degree of fibrosis, the response to previous therapy, the viral load or the viral genotype. Nonetheless, viral breakthrough and relapse can still occur in the absence of detectable RAVs and after the use of highly effective DAAs, so that the true clinical impact of the presence of RAVs in therapeutic failure remains to be determined. PMID:27547001

Assessing anesthesiology residents' out-of-the-operating-room (OOOR) emergent airway management.

PubMed

Rochlen, Lauryn R; Housey, Michelle; Gannon, Ian; Mitchell, Shannon; Rooney, Deborah M; Tait, Alan R; Engoren, Milo

2017-07-15

At many academic institutions, anesthesiology residents are responsible for managing emergent intubations outside of the operating room (OOOR), with complications estimated to be as high as 39%. In order to create an OOOR training curriculum, we evaluated residents' familiarity with the content and correct adherence to the American Society of Anesthesiologists' Difficult Airway Algorithm (ASA DAA). Residents completed a pre-simulation multiple-choice survey measuring their understanding and use of the DAA. Residents then managed an emergent, difficult OOOR intubation in the simulation center, where two trained reviewers assessed performance using checklists. Post-simulation, the residents completed a survey rating their behaviors during the simulation. The primary outcome was comprehension and adherence to the DAA as assessed by survey responses and behavior in the simulation. Sixty-three residents completed both surveys and the simulation. Post-survey responses indicated a shift toward decreased self-perceived familiarity with the DAA content compared to pre-survey responses. During the simulation, 22 (35%) residents were unsuccessful with intubation. Of these, 46% placed an LMA and 46% prepared for cricothyroidotomy. Nineteen residents did not attempt intubation. Of these, only 31% considered LMA placement, and 26% initiated cricothyroidotomy. Many anesthesiology residency training programs permit resident autonomy in managing emergent intubations OOOR. Residents self-reported familiarity with the content of and adherence to the DAA was higher than that observed during the simulation. Curriculum focused on comprehension of the DAA, as well as improving communication with higher-level physicians and specialists, may improve outcomes during OOORs.

Increased incidence of liver cancer after successful DAA treatment of chronic hepatitis C: Fact or fiction?

PubMed

Alberti, Alfredo; Piovesan, Sara

2017-06-01

Therapy of hepatitis C has been revolutionized by Direct Antiviral Agents. These drugs are safe and efficacious in all infected patients, including those with advanced, or decompensated cirrhosis, and are currently largely used in such cases in clinical practice worldwide. It was therefore cause of great concern the publication of two reports suggesting that treatment with DAAs could increase the risk of hepatocellular carcinoma in cirrhotic patients, particularly in those receiving antiviral therapy after having been cured for an HCC. These reports have generated a great and controversial debate and have been followed by a series of other publications not confirming such increased risk. This article summarizes published studies assessing the relation between DAA therapy and HCC in two different clinical setting: HCC recurrence in patients with an history of cured HCC and "de novo" HCC occurrence in patients without previous HCC. Rates of HCC recurrence after DAAs were extremely variable in different studies, reflecting great heterogeneity of this clinical setting. Data on "de novo" HCC incidence were more homogeneous and suggest that treatment with DAAs is not modifying the risk of developing HCC in the first 6-12 months. The possibility that treatment with DAAs may favour tumour growth and spread in individual patients with active HCC foci is suggested by some observations but remains unproven. There is clearly a need for prospective studies designed to better define these issues. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Treatment of chronic hepatitis C with direct-acting antivirals: The role of resistance.

PubMed

Jiménez-Pérez, Miguel; González-Grande, Rocío; España Contreras, Pilar; Pinazo Martínez, Isabel; de la Cruz Lombardo, Jesús; Olmedo Martín, Raúl

2016-08-07

The use of direct-acting antivirals (DAAs) to treat chronic hepatitis C has resulted in a significant increase in rates of sustained viral response (around 90%-95%) as compared with the standard treatment of peginterferon/ribavirin. Despite this, however, the rates of therapeutic failure in daily clinical practice range from 10%-15%. Most of these cases are due to the presence of resistant viral variants, resulting from mutations produced by substitutions of amino acids in the viral target protein that reduce viral sensitivity to DAAs, thus limiting the efficacy of these drugs. The high genetic diversity of hepatitis C virus has resulted in the existence of resistance-associated variants (RAVs), sometimes even before starting treatment with DAAs, though generally at low levels. These pre-existing RAVs do not appear to impact on the sustained viral response, whereas those that appear after DAA therapy could well be determinant in virological failure with future treatments. As well as the presence of RAVs, virological failure to treatment with DAAs is generally associated with other factors related with a poor response, such as the degree of fibrosis, the response to previous therapy, the viral load or the viral genotype. Nonetheless, viral breakthrough and relapse can still occur in the absence of detectable RAVs and after the use of highly effective DAAs, so that the true clinical impact of the presence of RAVs in therapeutic failure remains to be determined.

Increased peripheral CD4+ regulatory T cells persist after successful direct-acting antiviral treatment of chronic hepatitis C.

PubMed

Langhans, Bettina; Nischalke, Hans Dieter; Krämer, Benjamin; Hausen, Annekristin; Dold, Leona; van Heteren, Peer; Hüneburg, Robert; Nattermann, Jacob; Strassburg, Christian P; Spengler, Ulrich

2017-05-01

CD4 + regulatory T cells (Tregs) expand during chronic hepatitis C virus (HCV) infection, inhibit antiviral immunity and promote fibrosis. Direct-acting antiviral agents (DAA) have revolutionized HCV therapy. However, it is unclear if Tregs are normalized after DAA-induced HCV elimination. We analyzed Tregs before (baseline), at end of therapy (EOT), 12 and 24weeks (SVR12, SVR24) and long-term (51±14weeks) after EOT in 26 genotype-1-infected patients who were successfully treated with sofosbuvir (SOF) plus interferon (IFN)/ribavirin (n=12) and IFN-free DAA regimens (SOF plus daclatasvir or simeprevir; n=14). Frequency, phenotype and suppressor function of peripheral Foxp3 + CD25 + CD4 + T cells were studied by multi-color flow cytometry and co-culture inhibition assays. Frequencies and activation status of Foxp3 + CD25 + CD4 + T cells remained elevated above those of normal controls in both treatment groups even long-term after HCV elimination. Co-culture assays indicated a dose-response relationship for functional inhibition of autologous CD4 + effector T cells and confirmed that activation of Tregs remained largely unchanged over the observation period. Unlike IFN-free regimens, SOF plus IFN/ribavirin induced a transiently increased frequency of Foxp3 + CD25 + CD4 + T cells at EOT (5.0% at baseline to 6.1% at EOT; p=0.001). These Foxp3 + CD25 + CD4 + T cells co-expressed the activation markers glycoprotein A repetitions predominant (GARP; p=0.012) and tumor necrosis factor receptor superfamily, member 4 (OX-40; p=0.001) but showed unchanged in vitro inhibitory activity. Although IFN-based DAA therapy induced transient expansion of activated Foxp3 + CD25 + CD4 + T cells, neither IFN-based nor IFN-free DAA regimens normalized frequencies and activation status of Tregs one year after viral elimination. Persistence of immunosuppressive Tregs may thus contribute to complications of liver disease even long-term after HCV cure. In chronic hepatitis C virus (HCV) infection, CD4 + regulatory T cells (Tregs) can reduce antiviral immune responses, promote liver fibrosis and may increase the risk for liver cancer, because they gradually expand during disease. Modern direct-acting antiviral agents (DAA) can "cure" hepatitis C in almost all treated patients. However, our study shows that DAA do not normalize the increased frequency and activation status of Tregs even long-term after HCV elimination. Tregs may persistently modulate functions of the immune system even after "cure" of hepatitis C. Copyright © 2016 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

A population approach to disease management: hepatitis C direct-acting antiviral use in a large health care system.

PubMed

Belperio, Pamela S; Backus, Lisa I; Ross, David; Neuhauser, Melinda M; Mole, Larry A

2014-06-01

The introduction of the first direct-acting antiviral agents (DAAs) for the treatment of hepatitis C virus (HCV), telaprevir and boceprevir, marked a unique event in which 2 disease-changing therapies received FDA approval at the same time. Comparative safety and effectiveness data in real-world populations upon which to make formulary decisions did not exist. To describe the implementation, measurement, and outcomes of an enduring population-based approach of surveillance of medication management for HCV. The foundation of the population approach to HCV medication management used by the Department of Veterans Affairs (VA) relied upon a basic framework of (a) providing data for effective regional and local management, (b) education and training, (c) real-time oversight and feedback from a higher organization level, and (d) prompt outcome sharing. These population-based processes spanned across the continuum of the direct-acting antiviral oversight process. We used the VA's HCV Clinical Case Registry-which includes pharmacy, laboratory, and diagnosis information for all HCV-infected veterans from all VA facilities-to assess DAA treatment eligibility, DAA uptake and timing, appropriate use of DAAs including HCV RNA monitoring and medication possession ratios (MPR), nonconcordance with guidance for adjunct erythropoiesis-stimulating agent (ESA) and granulocyte colony-stimulating factor (GCSF) use, hematologic adverse effects, discontinuation rates, and early and sustained virologic responses. Training impact was assessed via survey and change in pharmacist scope of practice. One year after FDA approval, DAAs had been prescribed at 120 of 130 VA facilities. Over 680 VA providers participated in live educational training programs including 380 pharmacists, and pharmacists with a scope of practice for HCV increased from 59 to 110 pharmacists (86%). HCV RNA futility testing improved such that only 1%-3% of veterans did not have appropriate testing compared with 15%-17% 6 months earlier. By facility, the median proportion of veterans with MPR ≥ 0.95 remained 80% for those prescribed boceprevir; for telaprevir, the median proportion was 75% and improved to 80% 6 months later. Nonconcordance with VA medication guidance was as follows: receipt of an ESA without dose reducing ribavirin, 30% boceprevir, 45% telaprevir; ESA initiated with a hemoglobin greater than 10 g/dL, 42% boceprevir, 25% telaprevir; receipt of GCSF with absolute neutrophil count above the criteria threshold, 84%. This clinically focused, comprehensive, population-based medication management approach affected real-time change in health services, practice, and outcomes evidenced by widespread and rapid DAA uptake, improved HCV RNA monitoring, attention to adherence, and more appropriate management of DAA-related anemia. Timely outcome sharing provided decision makers and clinicians evidence to support current HCV practices.

Systems Engineering and Integration (SE and I)

NASA Technical Reports Server (NTRS)

Chevers, ED; Haley, Sam

1990-01-01

The issue of technology advancement and future space transportation vehicles is addressed. The challenge is to develop systems which can be evolved and improved in small incremental steps where each increment reduces present cost, improves, reliability, or does neither but sets the stage for a second incremental upgrade that does. Future requirements are interface standards for commercial off the shelf products to aid in the development of integrated facilities; enhanced automated code generation system slightly coupled to specification and design documentation; modeling tools that support data flow analysis; and shared project data bases consisting of technical characteristics cast information, measurement parameters, and reusable software programs. Topics addressed include: advanced avionics development strategy; risk analysis and management; tool quality management; low cost avionics; cost estimation and benefits; computer aided software engineering; computer systems and software safety; system testability; and advanced avionics laboratories - and rapid prototyping. This presentation is represented by viewgraphs only.

Open-Loop HIRF Experiments Performed on a Fault Tolerant Flight Control Computer

NASA Technical Reports Server (NTRS)

Koppen, Daniel M.

1997-01-01

During the third quarter of 1996, the Closed-Loop Systems Laboratory was established at the NASA Langley Research Center (LaRC) to study the effects of High Intensity Radiated Fields on complex avionic systems and control system components. This new facility provided a link and expanded upon the existing capabilities of the High Intensity Radiated Fields Laboratory at LaRC that were constructed and certified during 1995-96. The scope of the Closed-Loop Systems Laboratory is to place highly integrated avionics instrumentation into a high intensity radiated field environment, interface the avionics to a real-time flight simulation that incorporates aircraft dynamics, engines, sensors, actuators and atmospheric turbulence, and collect, analyze, and model aircraft performance. This paper describes the layout and functionality of the Closed-Loop Systems Laboratory, and the open-loop calibration experiments that led up to the commencement of closed-loop real-time flight experiments.

High speed bus technology development

NASA Astrophysics Data System (ADS)

Modrow, Marlan B.; Hatfield, Donald W.

1989-09-01

The development and demonstration of the High Speed Data Bus system, a 50 Million bits per second (Mbps) local data network intended for avionics applications in advanced military aircraft is described. The Advanced System Avionics (ASA)/PAVE PILLAR program provided the avionics architecture concept and basic requirements. Designs for wire and fiber optic media were produced and hardware demonstrations were performed. An efficient, robust token-passing protocol was developed and partially demonstrated. The requirements specifications, the trade-offs made, and the resulting designs for both a coaxial wire media system and a fiber optics design are examined. Also, the development of a message-oriented media access protocol is described, from requirements definition through analysis, simulation and experimentation. Finally, the testing and demonstrations conducted on the breadboard and brassboard hardware is presented.

NextGen Avionics Roadmap Version 1.0

DTIC Science & Technology

2008-10-24

monetized benefit streams when available. Since the source analyses had been conducted at different times using a range of operational and economic...Mrkoci BAE Systems Dave Nakamura Boeing Rob Pappas FAA Dharmesh Patel Honeywell Art Politano FAA Jean- Claude Richard Thales Avionics Brian E. Smith

An Open Avionics and Software Architecture to Support Future NASA Exploration Missions

NASA Technical Reports Server (NTRS)

Schlesinger, Adam

2017-01-01

The presentation describes an avionics and software architecture that has been developed through NASAs Advanced Exploration Systems (AES) division. The architecture is open-source, highly reliable with fault tolerance, and utilizes standard capabilities and interfaces, which are scalable and customizable to support future exploration missions. Specific focus areas of discussion will include command and data handling, software, human interfaces, communication and wireless systems, and systems engineering and integration.

Application of industry-standard guidelines for the validation of avionics software

NASA Technical Reports Server (NTRS)

Hayhurst, Kelly J.; Shagnea, Anita M.

1990-01-01

The application of industry standards to the development of avionics software is discussed, focusing on verification and validation activities. It is pointed out that the procedures that guide the avionics software development and testing process are under increased scrutiny. The DO-178A guidelines, Software Considerations in Airborne Systems and Equipment Certification, are used by the FAA for certifying avionics software. To investigate the effectiveness of the DO-178A guidelines for improving the quality of avionics software, guidance and control software (GCS) is being developed according to the DO-178A development method. It is noted that, due to the extent of the data collection and configuration management procedures, any phase in the life cycle of a GCS implementation can be reconstructed. Hence, a fundamental development and testing platform has been established that is suitable for investigating the adequacy of various software development processes. In particular, the overall effectiveness and efficiency of the development method recommended by the DO-178A guidelines are being closely examined.

Military Curriculum Materials for Vocational and Technical Education. Avionics Instrument Systems Specialist. POI C3ABR32531 000. Classroom Course 2-7.

ERIC Educational Resources Information Center

Ohio State Univ., Columbus. National Center for Research in Vocational Education.

This high school-postsecondary-level course for avionics instrument systems specialist is one of a number of military-developed curriculum packages selected for adaptation to vocational instruction and curriculum development in a civilian setting. A plan of instruction outlines five blocks of instruction (281 hours of instruction). Block 1,…

Power, Avionics and Software Communication Network Architecture

NASA Technical Reports Server (NTRS)

Ivancic, William D.; Sands, Obed S.; Bakula, Casey J.; Oldham, Daniel R.; Wright, Ted; Bradish, Martin A.; Klebau, Joseph M.

2014-01-01

This document describes the communication architecture for the Power, Avionics and Software (PAS) 2.0 subsystem for the Advanced Extravehicular Mobile Unit (AEMU). The following systems are described in detail: Caution Warn- ing and Control System, Informatics, Storage, Video, Audio, Communication, and Monitoring Test and Validation. This document also provides some background as well as the purpose and goals of the PAS project at Glenn Research Center (GRC).

Software-Defined Avionics and Mission Systems in Future Vertical Lift Aircraft

DTIC Science & Technology

2015-03-01

military rotorcraft in the service of the United States Joint services have yet to benefit significantly from this technology. At long last, that may...Despite the demonstrated success of IMA systems in commercial airliners such as the Airbus A380 and the Boeing 787, military rotorcraft in the...8 4. Integrated Modular Avionics (IMA) – Generation One ..................9 5. Military IMA

Integrated Control Design Techniques

DTIC Science & Technology

1981-08-01

Avionics and Electronic Systems, " Presented at NAECON 󈨔, Dayton, Ohio, May 1980. 3 9 E. Louis Wienecke, III, Erasmus E. Feltus , and Daniel V. Ferens...34 Presented at NAECON 󈨔, Dayton, Ohio, May 1980. 39. Wienecke, E. Louis, III; Feltus , Erasmus E.; and Ferens, Daniel V. "The Avionics Laboratory

Critical issues regarding SEU in avionics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Normand, E.; McNulty, P.J.

1993-01-01

The energetic neutrons in the atmosphere cause microelectronics in avionic system to malfunction through a mechanism called single-event upsets (SEUs), and single-event latchup is a potential threat. Data from military and experimental flights as well as laboratory testing indicate that typical non-radiation-hardened 64K and 256K static random access memories (SRAMs) can experience a significant SEU rate at aircraft altitudes. Microelectronics in avionics systems have been demonstrated to be susceptible to SEU. Of all device types, RAMs are the most sensitive because they have the largest number of bits on a chip (e.g., an SRAM may have from 64K to 1Mmore » bits, a microprocessor 3K to 10K bits, and a logic device like an analog-to-digital converter, 12 bits). Avionics designers will need to take this susceptibility into account in current and future designs. A number of techniques are available for dealing with SEU: EDAC, redundancy, use of SEU-hard parts, reset and/or watchdog timer capability, etc. Specifications should be developed to guide avionics vendors in the analysis, prevention, and verification of neutron-induced SEU. Areas for additional research include better definition of the atmospheric neutrons and protons, development of better calculational models (e.g., those used for protons[sup 11]), and better characterization of neutron-induced latchup.« less

CrowdHEALTH: Holistic Health Records and Big Data Analytics for Health Policy Making and Personalized Health.

PubMed

Kyriazis, Dimosthenis; Autexier, Serge; Brondino, Iván; Boniface, Michael; Donat, Lucas; Engen, Vegard; Fernandez, Rafael; Jimenez-Peris, Ricardo; Jordan, Blanca; Jurak, Gregor; Kiourtis, Athanasios; Kosmidis, Thanos; Lustrek, Mitja; Maglogiannis, Ilias; Mantas, John; Martinez, Antonio; Mavrogiorgou, Argyro; Menychtas, Andreas; Montandon, Lydia; Nechifor, Cosmin-Septimiu; Nifakos, Sokratis; Papageorgiou, Alexandra; Patino-Martinez, Marta; Perez, Manuel; Plagianakos, Vassilis; Stanimirovic, Dalibor; Starc, Gregor; Tomson, Tanja; Torelli, Francesco; Traver-Salcedo, Vicente; Vassilacopoulos, George; Wajid, Usman

2017-01-01

Today's rich digital information environment is characterized by the multitude of data sources providing information that has not yet reached its full potential in eHealth. The aim of the presented approach, namely CrowdHEALTH, is to introduce a new paradigm of Holistic Health Records (HHRs) that include all health determinants. HHRs are transformed into HHRs clusters capturing the clinical, social and human context of population segments and as a result collective knowledge for different factors. The proposed approach also seamlessly integrates big data technologies across the complete data path, providing of Data as a Service (DaaS) to the health ecosystem stakeholders, as well as to policy makers towards a "health in all policies" approach. Cross-domain co-creation of policies is feasible through a rich toolkit, being provided on top of the DaaS, incorporating mechanisms for causal and risk analysis, and for the compilation of predictions.

Digital avionics systems - Overview of FAA/NASA/industry-wide briefing

NASA Technical Reports Server (NTRS)

Larsen, William E.; Carro, Anthony

1986-01-01

The effects of incorporating digital technology into the design of aircraft on the airworthiness criteria and certification procedures for aircraft are investigated. FAA research programs aimed at providing data for the functional assessment of aircraft which use digital systems for avionics and flight control functions are discussed. The need to establish testing, assurance assessment, and configuration management technologies to insure the reliability of digital systems is discussed; consideration is given to design verification, system performance/robustness, and validation technology.

Digital avionics design and reliability analyzer

NASA Technical Reports Server (NTRS)

1981-01-01

The description and specifications for a digital avionics design and reliability analyzer are given. Its basic function is to provide for the simulation and emulation of the various fault-tolerant digital avionic computer designs that are developed. It has been established that hardware emulation at the gate-level will be utilized. The primary benefit of emulation to reliability analysis is the fact that it provides the capability to model a system at a very detailed level. Emulation allows the direct insertion of faults into the system, rather than waiting for actual hardware failures to occur. This allows for controlled and accelerated testing of system reaction to hardware failures. There is a trade study which leads to the decision to specify a two-machine system, including an emulation computer connected to a general-purpose computer. There is also an evaluation of potential computers to serve as the emulation computer.

Fleet retrofit report

NASA Technical Reports Server (NTRS)

1973-01-01

Flight tests are evaluated of an avionics system which aids the pilot in making two-segment approaches for noise abatement. The implications are discussed of equipping United's fleet of Boeing 727-200 aircraft with two-segment avionics for use down to Category 2 weather operating minima. The experience is reported of incorporating two-segment approach avionics systems on two different aircraft. The cost of installing dual two-segment approach systems is estimated to be $37,015 per aircraft, including parts, labor, and spares. This is based on the assumption that incremental out-of-service and training costs could be minimized by incorporating the system at airframe overhaul cycle and including training in regular recurrent training. Accelerating the modification schedule could add up to 50 percent to the modification costs. Recurring costs of maintenance of the installation are estimated to be of about the same magnitude as the potential recurrent financial benefits due to fuel savings.

Heavy Lift Launch Vehicles for 1995 and Beyond

NASA Technical Reports Server (NTRS)

Toelle, R. (Compiler)

1985-01-01

A Heavy Lift Launch Vehicle (HLLV) designed to deliver 300,000 lb to a 540 n mi circular polar orbit may be required to meet national needs for 1995 and beyond. The vehicle described herein can accommodate payload envelopes up to 50 ft diameter by 200 ft in length. Design requirements include reusability for the more expensive components such as avionics and propulsion systems, rapid launch turnaround time, minimum hardware inventory, stage and component flexibility and commonality, and low operational costs. All ascent propulsion systems utilize liquid propellants, and overall launch vehicle stack height is minimized while maintaining a reasonable vehicle diameter. The ascent propulsion systems are based on the development of a new liquid oxygen/hydrocarbon booster engine and liquid oxygen/liquid hydrogen upper stage engine derived from today's SSME technology. Wherever possible, propulsion and avionics systems are contained in reusable propulsion/avionics modules that are recovered after each launch.

Comparative Analysis of ACAS-Xu and DAIDALUS Detect-and-Avoid Systems

NASA Technical Reports Server (NTRS)

Davies, Jason T.; Wu, Minghong G.

2018-01-01

The Detect and Avoid (DAA) capability of a recent version (Run 3) of the Airborne Collision Avoidance System-Xu (ACAS-Xu) is measured against that of the Detect and AvoID Alerting Logic for Unmanned Systems (DAIDALUS), a reference algorithm for the Phase 1 Minimum Operational Performance Standards (MOPS) for DAA. This comparative analysis of the two systems' alerting and horizontal guidance outcomes is conducted through the lens of the Detect and Avoid mission using flight data of scripted encounters from a recent flight test. Results indicate comparable timelines and outcomes between ACAS-Xu's Remain Well Clear alert and guidance and DAIDALUS's corrective alert and guidance, although ACAS-Xu's guidance appears to be more conservative. ACAS-Xu's Collision Avoidance alert and guidance occurs later than DAIDALUS's warning alert and guidance, and overlaps with DAIDALUS's timeline of maneuver to remain Well Clear. Interesting discrepancies between ACAS-Xu's directive guidance and DAIDALUS's "Regain Well Clear" guidance occur in some scenarios.

Considerations for RTCA Phase 2 Low Size, Weight, and Power (SWAP) Surveillance Requirements. UAS Integration in the NAS

NASA Technical Reports Server (NTRS)

Santiago, Confesor

2017-01-01

RTCA (Radio Technical Commission for Aeronautics) Special Committee 228 has initiated a second phase for the development of minimum operational performance standards (MOPS) for UAS (Unmanned Aircraft Systems) detect and avoid (DAA) systems. Technologies to enable UAS with less available Size, Weight, and Power (SWaP) will be considered. A white paper is in development for what topics and issues need to be addressed to develop DAA requirements for low SWAP surveillance systems. This briefing will document the issues to be investigated in SC-228. It will also serve as a review with the committee to get feedback so the white paper can be written and finalized. These topics and issues are not necessarily all the things that NASA will contribute to SC-228 during Phase 2, but what the overall committee needs to accomplish. A portion of the work will be in NASA's UAS in the NAS (National Airspace System) project plan.

Primary display latency criteria based on flying qualities and performance data

NASA Technical Reports Server (NTRS)

Funk, John D., Jr.; Beck, Corin P.; Johns, John B.

1993-01-01

With a pilots' increasing use of visual cue augmentation, much requiring extensive pre-processing, there is a need to establish criteria for new avionics/display design. The timeliness and synchronization of the augmented cues is vital to ensure the performance quality required for precision mission task elements (MTEs) where augmented cues are the primary source of information to the pilot. Processing delays incurred while transforming sensor-supplied flight information into visual cues are unavoidable. Relationships between maximum control system delays and associated flying qualities levels are documented in MIL-F-83300 and MIL-F-8785. While cues representing aircraft status may be just as vital to the pilot as prompt control response for operations in instrument meteorological conditions, presently, there are no specification requirements on avionics system latency. To produce data relating avionics system latency to degradations in flying qualities, the Navy conducted two simulation investigations. During the investigations, flying qualities and performance data were recorded as simulated avionics system latency was varied. Correlated results of the investigation indicates that there is a detrimental impact of latency on flying qualities. Analysis of these results and consideration of key factors influencing their application indicate that: (1) Task performance degrades and pilot workload increases as latency is increased. Inconsistency in task performance increases as latency increases. (2) Latency reduces the probability of achieving Level 1 handling qualities with avionics system latency as low as 70 ms. (3) The data suggest that the achievement of desired performance will be ensured only at display latency values below 120 ms. (4) These data also suggest that avoidance of inadequate performance will be ensured only at display latency values below 150 ms.

[Effects of shading at different phases of grain-filling on wheat grain protein components contents and processing quality].

PubMed

Shi, Yu; Chen, Mao-xue; Yu, Zhen-wen; Xu, Zhen-zhu

2011-10-01

Taking three wheat cultivars Jimai 20 (strong gluten), Taishan 23 (medium gluten), and Ningmai 9 (weak gluten) as test materials, a field experiment was conducted to examine the effects of shading at different phases of grain-filling on the grain protein components contents and processing quality. Four treatments were installed, i. e., no shading (S0), shading at early grain-filling phase (from 0 day after anthesis (DAA) to 11 DAA; S1), shading at medium grain-filling phase (from 12 DAA to 23 DAA; S2), and shading at late grain-filling phase (from 24 DAA to 35 DAA; S3). No significant differences were observed in the grain albumin+globulin contents of the three cultivars among the four treatments. Shading increased the grain HMW-GS, LMW-GS, gluten, glutenin, and total protein contents of Jimai 20 and Taishan 23 significantly, and the increments were higher in treatment S2 than in other shading treatments. Treatments S2 and S3 increased the grain protein components contents of Ningmai 9 significantly. Comparing with the control, shading decreased the grain yield significantly, but increased the dough development time, dough stability time, and sedimentation volume, especially for treatment S2, which suggested that the wheat grain quality had a close relationship with the light intensity at medium phase of grain-filling. Overall, the regulation effect of shading at grain-filling stage on the wheat grain yield, grain protein components contents, and indices values of grain processing quality for the test cultivars was in the order of Jimai 20 > Taishan 23 > Ningmai 9.

Using ARINC 818 Avionics Digital Video Bus (ADVB) for military displays

NASA Astrophysics Data System (ADS)

Alexander, Jon; Keller, Tim

2007-04-01

ARINC 818 Avionics Digital Video Bus (ADVB) is a new digital video interface and protocol standard developed especially for high bandwidth uncompressed digital video. The first draft of this standard, released in January of 2007, has been advanced by ARINC and the aerospace community to meet the acute needs of commercial aviation for higher performance digital video. This paper analyzes ARINC 818 for use in military display systems found in avionics, helicopters, and ground vehicles. The flexibility of ARINC 818 for the diverse resolutions, grayscales, pixel formats, and frame rates of military displays is analyzed as well as the suitability of ARINC 818 to support requirements for military video systems including bandwidth, latency, and reliability. Implementation issues relevant to military displays are presented.

Effectiveness evaluation of STOL transport operations

NASA Technical Reports Server (NTRS)

Hitt, E. F.; Bruckner, J. M. H.; Drago, V. J.; Brown, R. A.; Rea, F. G.; Porter, R. F.

1973-01-01

A short-takeoff and landing (STOL) systems simulation model has been developed and implemented in a computer code (known as STOL OPS) which permits evaluation of the operation of a STOL aircraft and its avionics in a commercial airline operating environment. STOL OPS concentrated on the avionics functions of navigation, guidance, control, communication, hazard aviodance, and systems management. External world factors influencing the operation of the STOL aircraft include each airport and its geometry, air traffic at each airport, air traffic control equipment and procedures, weather (including winds and visibility), and the flight path between each airport served by the route. The development of the STOL OPS program provides NASA a set of computer programs which can be used for detailed analysis of a STOL aircraft and its avionics and permit establishment of system requirements as a function of airline mission performance goals.

Spacecraft Avionics Software Development Then and Now: Different but the Same

NASA Technical Reports Server (NTRS)

Mangieri, Mark L.; Garman, John (Jack); Vice, Jason

2012-01-01

NASA has always been in the business of balancing new technologies and techniques to achieve human space travel objectives. NASA s historic Software Production Facility (SPF) was developed to serve complex avionics software solutions during an era dominated by mainframes, tape drives, and lower level programming languages. These systems have proven themselves resilient enough to serve the Shuttle Orbiter Avionics life cycle for decades. The SPF and its predecessor the Software Development Lab (SDL) at NASA s Johnson Space Center (JSC) hosted flight software (FSW) engineering, development, simulation, and test. It was active from the beginning of Shuttle Orbiter development in 1972 through the end of the shuttle program in the summer of 2011 almost 40 years. NASA s Kedalion engineering analysis lab is on the forefront of validating and using many contemporary avionics HW/SW development and integration techniques, which represent new paradigms to NASA s heritage culture in avionics software engineering. Kedalion has validated many of the Orion project s HW/SW engineering techniques borrowed from the adjacent commercial aircraft avionics environment, inserting new techniques and skills into the Multi-Purpose Crew Vehicle (MPCV) Orion program. Using contemporary agile techniques, COTS products, early rapid prototyping, in-house expertise and tools, and customer collaboration, NASA has adopted a cost effective paradigm that is currently serving Orion effectively. This paper will explore and contrast differences in technology employed over the years of NASA s space program, due largely to technological advances in hardware and software systems, while acknowledging that the basic software engineering and integration paradigms share many similarities.

Comparison of Communication Architectures for Spacecraft Modular Avionics Systems

NASA Technical Reports Server (NTRS)

Gwaltney, D. A.; Briscoe, J. M.

2006-01-01

This document is a survey of publicly available information concerning serial communication architectures used, or proposed to be used, in aeronautic and aerospace applications. It focuses on serial communication architectures that are suitable for low-latency or real-time communication between physically distributed nodes in a system. Candidates for the study have either extensive deployment in the field, or appear to be viable for near-term deployment. Eleven different serial communication architectures are considered, and a brief description of each is given with the salient features summarized in a table in appendix A. This survey is a product of the Propulsion High Impact Avionics Technology (PHIAT) Project at NASA Marshall Space Flight Center (MSFC). PHIAT was originally funded under the Next Generation Launch Technology (NGLT) Program to develop avionics technologies for control of next generation reusable rocket engines. After the announcement of the Space Exploration Initiative, the scope of the project was expanded to include vehicle systems control for human and robotics missions. As such, a section is included presenting the rationale used for selection of a time-triggered architecture for implementation of the avionics demonstration hardware developed by the project team

Validation Methods for Fault-Tolerant avionics and control systems, working group meeting 1

NASA Technical Reports Server (NTRS)

1979-01-01

The proceedings of the first working group meeting on validation methods for fault tolerant computer design are presented. The state of the art in fault tolerant computer validation was examined in order to provide a framework for future discussions concerning research issues for the validation of fault tolerant avionics and flight control systems. The development of positions concerning critical aspects of the validation process are given.

Avionics System Design for High Energy Fields

DTIC Science & Technology

1988-07-01

this report describes design practices which will lead to reducc electromagnetic susceptibility of avionics systems in high energy fields . A second...nuclear reactions. Tn most cases the radiation which causes electromagnetic interference Is completely harmless to humans . Many techniqteq are used in...variety of electromagnetic compatibility problems. 1,e fIrst use EMCad to preeict the field strength from a discharge. Next, we usc’e r. a second

Strategic avionics technology definition studies. Subtask 3-1A: Electrical Actuation (ELA) systems

NASA Technical Reports Server (NTRS)

Lum, Ben T. F.; Pond, Charles; Dermott, William

1993-01-01

This interim report presents the preliminary results of an electrical actuation (ELA) system study (subtask TA3-1A) to support the NASA strategic avionics technology definition studies. The final report of this ELA study is scheduled for September 30, 1993. The topics are presented in viewgraph form and include the following ELA technology demonstration testing; ELA system baseline; power and energy requirements for shuttle effector systems; power efficiency and losses of ELA effector systems; and power and energy requirements for ELA power sources.

Proceedings Papers of the AFSC (Air Force Systems Command) Avionics Standardization Conference (2nd) Held at Dayton, Ohio on 30 November-2 December 1982. Volume 1.

DTIC Science & Technology

1982-11-01

Avionic Systems Integration Facilities, Mark van den Broek 1113 and Paul M. Vicen, AFLC/LOE Planning of Operational Software Implementation Tool...classified as software tools, including: * o" Operating System " Language Processors (compilers, assem’blers, link editors) o Source Editors " Debug Systems ...o Data Base Systems o Utilities o Etc . This talk addresses itself to the current set of tools provided JOVIAL iJ73 1750A application programmners by

Avionics of the Cyclone Global Navigation Satellite System (CYGNSS) microsat constellation

NASA Astrophysics Data System (ADS)

Dickinson, John R.; Alvarez, Jennifer L.; Rose, Randall J.; Ruf, Christopher S.; Walls, Buddy J.

The Cyclone Global Navigation Satellite System (CYGNSS), which was recently selected as the Earth Venture-2 investigation by NASA's Earth Science System Pathfinder (ESSP) Program, measures the ocean surface wind field with unprecedented temporal resolution and spatial coverage, under all precipitating conditions, and over the full dynamic range of wind speeds experienced in a tropical cyclone (TC). The CYGNSS flight segment consists of 8 microsatellite-class observatories, which represent SwRI's first spacecraft bus design, installed on a Deployment Module for launch. They are identical in design but provide their own individual contribution to the CYGNSS science data set. Subsystems include the Attitude Determination and Control System (ADCS), the Communication and Data Subsystem (CDS), the Electrical Power Supply (EPS), and the Structure, Mechanisms, and Thermal Subsystem (SMT). This paper will present an overview of the mission and the avionics, including the ADCS, CDS, and EPS, in detail. Specifically, we will detail how off-the-shelf components can be utilized to do ADCS and will highlight how SwRI's existing avionics solutions will be adapted to meet the requirements and cost constraints of microsat applications. Avionics electronics provided by SwRI include a command and data handling computer, a transceiver radio, a low voltage power supply (LVPS), and a peak power tracker (PPT).

Geno2pheno[HCV] – A Web-based Interpretation System to Support Hepatitis C Treatment Decisions in the Era of Direct-Acting Antiviral Agents

PubMed Central

Kalaghatgi, Prabhav; Sikorski, Anna Maria; Knops, Elena; Rupp, Daniel; Sierra, Saleta; Heger, Eva; Neumann-Fraune, Maria; Beggel, Bastian; Walker, Andreas; Timm, Jörg; Walter, Hauke; Obermeier, Martin; Kaiser, Rolf; Bartenschlager, Ralf; Lengauer, Thomas

2016-01-01

The face of hepatitis C virus (HCV) therapy is changing dramatically. Direct-acting antiviral agents (DAAs) specifically targeting HCV proteins have been developed and entered clinical practice in 2011. However, despite high sustained viral response (SVR) rates of more than 90%, a fraction of patients do not eliminate the virus and in these cases treatment failure has been associated with the selection of drug resistance mutations (RAMs). RAMs may be prevalent prior to the start of treatment, or can be selected under therapy, and furthermore they can persist after cessation of treatment. Additionally, certain DAAs have been approved only for distinct HCV genotypes and may even have subtype specificity. Thus, sequence analysis before start of therapy is instrumental for managing DAA-based treatment strategies. We have created the interpretation system geno2pheno[HCV] (g2p[HCV]) to analyse HCV sequence data with respect to viral subtype and to predict drug resistance. Extensive reviewing and weighting of literature related to HCV drug resistance was performed to create a comprehensive list of drug resistance rules for inhibitors of the HCV protease in non-structural protein 3 (NS3-protease: Boceprevir, Paritaprevir, Simeprevir, Asunaprevir, Grazoprevir and Telaprevir), the NS5A replicase factor (Daclatasvir, Ledipasvir, Elbasvir and Ombitasvir), and the NS5B RNA-dependent RNA polymerase (Dasabuvir and Sofosbuvir). Upon submission of up to eight sequences, g2p[HCV] aligns the input sequences, identifies the genomic region(s), predicts the HCV geno- and subtypes, and generates for each DAA a drug resistance prediction report. g2p[HCV] offers easy-to-use and fast subtype and resistance analysis of HCV sequences, is continuously updated and freely accessible under http://hcv.geno2pheno.org/index.php. The system was partially validated with respect to the NS3-protease inhibitors Boceprevir, Telaprevir and Simeprevir by using data generated with recombinant, phenotypic cell culture assays obtained from patients’ virus variants. PMID:27196673

Current evidence in the stability of medicines in dose administration aids: implications for patient safety.

PubMed

García, Estela R; Thalhauser, Stefanie; Loscertales, Hèctor R; Modamio, Pilar; Lastra, Cecilia F; Mariño, Eduardo L

2018-06-01

As the elderly population and polypharmacy are increasing, it is predicted that interventions to enhance medication adherence, as dose administration aids (DAA), will grow. One of the limitations of repackaging medicines into DAA is to assure the stability of medicines, and, therefore, their quality, efficacy and safety. Area covered: This article collects and summarises data of all the stability studies of repackaged medicines into DAAs. Computerized search in databases: PubMed, Google Scholar, SciELO, and reference texts related to the field (keywords: drug stability, DAAs, compliance aids, and repackaging), open access databases and guidelines. Also, it provides recommendations on the suitability of repackaging and compares them with those established. Expert opinion: Since medicines are removed from primary package, their stability can be compromised due to psychochemical characteristics of the drug substance and product, the dosage form, the type of DAA selected, the co-storage and splitting, the repackaging conditions, and the conditions of storage. This review reflects the need of more standardized stability studies to guarantee the quality of repackaged medicines. In addition, the importance of them to support the pharmacist to make the best decisions in order to maximize outcomes and minimize risks related to patients' medication when repackaging it.

Projection display technology for avionics applications

NASA Astrophysics Data System (ADS)

Kalmanash, Michael H.; Tompkins, Richard D.

2000-08-01

Avionics displays often require custom image sources tailored to demanding program needs. Flat panel devices are attractive for cockpit installations, however recent history has shown that it is not possible to sustain a business manufacturing custom flat panels in small volume specialty runs. As the number of suppliers willing to undertake this effort shrinks, avionics programs unable to utilize commercial-off-the-shelf (COTS) flat panels are placed in serious jeopardy. Rear projection technology offers a new paradigm, enabling compact systems to be tailored to specific platform needs while using a complement of COTS components. Projection displays enable improved performance, lower cost and shorter development cycles based on inter-program commonality and the wide use of commercial components. This paper reviews the promise and challenges of projection technology and provides an overview of Kaiser Electronics' efforts in developing advanced avionics displays using this approach.

Validation Methods Research for Fault-Tolerant Avionics and Control Systems Sub-Working Group Meeting. CARE 3 peer review

NASA Technical Reports Server (NTRS)

Trivedi, K. S. (Editor); Clary, J. B. (Editor)

1980-01-01

A computer aided reliability estimation procedure (CARE 3), developed to model the behavior of ultrareliable systems required by flight-critical avionics and control systems, is evaluated. The mathematical models, numerical method, and fault-tolerant architecture modeling requirements are examined, and the testing and characterization procedures are discussed. Recommendations aimed at enhancing CARE 3 are presented; in particular, the need for a better exposition of the method and the user interface is emphasized.

Human Factors Assessment of the UH-60M Common Avionics Architecture System (CAAS) Crew Station During the Limited User Evaluation (LEUE)

DTIC Science & Technology

2005-12-01

weapon system evaluation as a high-level architecture and distributed interactive simulation 6 compliant, human-in-the-loop, virtual environment...Directorate to participate in the Limited Early User Evaluation (LEUE) of the Common Avionics Architecture System (CAAS) cockpit. ARL conducted a human...CAAS, the UH-60M PO conducted a limited early user evaluation (LEUE) to evaluate the integration of the CAAS in the UH-60M crew station. The

Modeling cost-effectiveness and health gains of a "universal" versus "prioritized" hepatitis C virus treatment policy in a real-life cohort.

PubMed

Kondili, Loreta A; Romano, Federica; Rolli, Francesca Romana; Ruggeri, Matteo; Rosato, Stefano; Brunetto, Maurizia Rossana; Zignego, Anna Linda; Ciancio, Alessia; Di Leo, Alfredo; Raimondo, Giovanni; Ferrari, Carlo; Taliani, Gloria; Borgia, Guglielmo; Santantonio, Teresa Antonia; Blanc, Pierluigi; Gaeta, Giovanni Battista; Gasbarrini, Antonio; Chessa, Luchino; Erne, Elke Maria; Villa, Erica; Ieluzzi, Donatella; Russo, Francesco Paolo; Andreone, Pietro; Vinci, Maria; Coppola, Carmine; Chemello, Liliana; Madonia, Salvatore; Verucchi, Gabriella; Persico, Marcello; Zuin, Massimo; Puoti, Massimo; Alberti, Alfredo; Nardone, Gerardo; Massari, Marco; Montalto, Giuseppe; Foti, Giuseppe; Rumi, Maria Grazia; Quaranta, Maria Giovanna; Cicchetti, Americo; Craxì, Antonio; Vella, Stefano

2017-12-01

We evaluated the cost-effectiveness of two alternative direct-acting antiviral (DAA) treatment policies in a real-life cohort of hepatitis C virus-infected patients: policy 1, "universal," treat all patients, regardless of fibrosis stage; policy 2, treat only "prioritized" patients, delay treatment of the remaining patients until reaching stage F3. A liver disease progression Markov model, which used a lifetime horizon and health care system perspective, was applied to the PITER cohort (representative of Italian hepatitis C virus-infected patients in care). Specifically, 8,125 patients naive to DAA treatment, without clinical, sociodemographic, or insurance restrictions, were used to evaluate the policies' cost-effectiveness. The patients' age and fibrosis stage, assumed DAA treatment cost of €15,000/patient, and the Italian liver disease costs were used to evaluate quality-adjusted life-years (QALY) and incremental cost-effectiveness ratios (ICER) of policy 1 versus policy 2. To generalize the results, a European scenario analysis was performed, resampling the study population, using the mean European country-specific health states costs and mean treatment cost of €30,000. For the Italian base-case analysis, the cost-effective ICER obtained using policy 1 was €8,775/QALY. ICERs remained cost-effective in 94%-97% of the 10,000 probabilistic simulations. For the European treatment scenario the ICER obtained using policy 1 was €19,541.75/QALY. ICER was sensitive to variations in DAA costs, in the utility value of patients in fibrosis stages F0-F3 post-sustained virological response, and in the transition probabilities from F0 to F3. The ICERs decrease with decreasing DAA prices, becoming cost-saving for the base price (€15,000) discounts of at least 75% applied in patients with F0-F2 fibrosis. Extending hepatitis C virus treatment to patients in any fibrosis stage improves health outcomes and is cost-effective; cost-effectiveness significantly increases when lowering treatment prices in early fibrosis stages. (Hepatology 2017;66:1814-1825). © 2017 The Authors. Hepatology published by Wiley Periodicals, Inc., on behalf of the American Association for the Study of Liver Diseases.

Disease-linked mutations in factor H reveal pivotal role of cofactor activity in self-surface-selective regulation of complement activation.

PubMed

Kerr, Heather; Wong, Edwin; Makou, Elisavet; Yang, Yi; Marchbank, Kevin; Kavanagh, David; Richards, Anna; Herbert, Andrew P; Barlow, Paul N

2017-08-11

Spontaneous activation enables the complement system to respond very rapidly to diverse threats. This activation is efficiently suppressed by complement factor H (CFH) on self-surfaces but not on foreign surfaces. The surface selectivity of CFH, a soluble protein containing 20 complement-control protein modules (CCPs 1-20), may be compromised by disease-linked mutations. However, which of the several functions of CFH drives this self-surface selectivity remains unknown. To address this, we expressed human CFH mutants in Pichia pastoris We found that recombinant I62-CFH (protective against age-related macular degeneration) and V62-CFH functioned equivalently, matching or outperforming plasma-derived CFH, whereas R53H-CFH, linked to atypical hemolytic uremic syndrome (aHUS), was defective in C3bBb decay-accelerating activity (DAA) and factor I cofactor activity (CA). The aHUS-linked CCP 19 mutant D1119G-CFH had virtually no CA on (self-like) sheep erythrocytes ( E S ) but retained DAA. The aHUS-linked CCP 20 mutant S1191L/V1197A-CFH (LA-CFH) had dramatically reduced CA on E S but was less compromised in DAA. D1119G-CFH and LA-CFH both performed poorly at preventing complement-mediated hemolysis of E S PspCN, a CFH-binding Streptococcus pneumoniae protein domain, binds CFH tightly and increases accessibility of CCPs 19 and 20. PspCN did not improve the DAA of any CFH variant on E S Conversely, PspCN boosted the CA, on E S , of I62-CFH, R53H-CFH, and LA-CFH and also enhanced hemolysis protection by I62-CFH and LA-CFH. We conclude that CCPs 19 and 20 are critical for efficient CA on self-surfaces but less important for DAA. Exposing CCPs 19 and 20 with PspCN and thus enhancing CA on self-surfaces may reverse deficiencies of some CFH variants. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Pendimethalin and oxyfluorfen degradation under two irrigation conditions over four years application.

PubMed

Alister, Claudio A; Gomez, Patricio A; Rojas, Sandra; Kogan, Marcelo

2009-05-01

A four-year field study was conducted to determine the effect of pluviometric conditions on pendimethalin and oxyfluorfen soil dynamics. Adsorption, dissipation and soil movement were studied in a sandy loam soil from 2003 to 2007. Pendimethalin and oxyfluorfen were applied every year on August at 1.33 and 0.75 kg ha(-1), respectively. Herbicide soil concentrations were determined at 0, 10, 20, 40, 90 and 340 days after application (DAA), under two pluviometric regimens, natural rainfall and irrigated (30 mm every 15 days during the first 90 DAA). More than 74% of the herbicide applied was detected at the top 2.5 cm layer for both herbicides, and none was detected at 10 cm or deeper. Pendimethalin soil half-life ranged from 10.5 to 31.5 days, and was affected mainly by the time interval between application and the first rain event. Pendimethalin soil residues at 90 DAA fluctuated from 2.5 to 13.8% of the initial amount applied, and it decreased to 2.4 and 8.6% at 340 DAA. Oxyfluorfen was more persistent than pendimethalin as indicated by its soil half-life which ranged from 34.3 to 52.3 days, affected primarily by the rain amount at the first rainfall after application. Oxyfluorfen soil residues at 90 DAA ranged from 16.7 to 34.8% and it decreased to 3.3 and 17.9% at 340 DAA. Based on half-life values, herbicide soil residues after one year, and soil depth reached by the herbicides, we conclude that both herbicides should be considered as low risk to contaminate groundwater. However, herbicide concentration at the top 2.5 cm layer should be considered in cases where runoff or soil erosion could occur, because of the potential for surface water contamination.

Availability of hepatitis C diagnostics and therapeutics in European and Eurasia countries.

PubMed

Leblebicioglu, Hakan; Arends, Joop E; Ozaras, Resat; Corti, Giampaolo; Santos, Lurdes; Boesecke, Christoph; Ustianowski, Andrew; Duberg, Ann-Sofi; Ruta, Simona; Salkic, Nermin N; Husa, Petr; Lazarevic, Ivana; Pineda, Juan A; Pshenichnaya, Natalia Yurievna; Tsertswadze, Tengiz; Matičič, Mojca; Puca, Edmond; Abuova, Gulzhan; Gervain, Judit; Bayramli, Ramin; Ahmeti, Salih; Koulentaki, Mairi; Kilani, Badreddine; Vince, Adriana; Negro, Francesco; Sunbul, Mustafa; Salmon, Dominique

2018-02-01

Treatment with direct acting antiviral agents (DAAs) has provided sustained virological response rates in >95% of patients with chronic hepatitis C virus (HCV) infection. However treatment is costly and market access, reimbursement and governmental restrictions differ among countries. We aimed to analyze these differences among European and Eurasian countries. A survey including 20-item questionnaire was sent to experts in viral hepatitis. Countries were evaluated according to their income categories by the World Bank stratification. Experts from 26 countries responded to the survey. As of May 2016, HCV prevalence was reported as low (≤1%) in Croatia, Czech Republic, Denmark, France, Germany, Hungary, the Netherlands, Portugal, Slovenia, Spain, Sweden, UK; intermediate (1-4%) in Azerbaijan, Bosnia and Herzegovina, Italy, Kosovo, Greece, Kazakhstan, Romania, Russia, Serbia and high in Georgia (6.7%). All countries had national guidelines except Albania, Kosovo, Serbia, Tunisia, and UK. Transient elastography was available in all countries, but reimbursed in 61%. HCV-RNA was reimbursed in 81%. PegIFN/RBV was reimbursed in 54% of the countries. No DAAs were available in four countries: Kazakhstan, Kosovo, Serbia, and Tunisia. In others, at least one DAA combination with either PegIFN/RBV or another DAA was available. In Germany and the Netherlands all DAAs were reimbursed without restrictions: Sofosbuvir and sofosbuvir/ledipasvir were free of charge in Georgia. Prevalence of HCV is relatively higher in lower-middle and upper-middle income countries. DAAs are not available or reimbursed in many Eurasia and European countries. Effective screening and access to care are essential for reducing liver-related morbidity and mortality. Copyright © 2017 Elsevier B.V. All rights reserved.

Curing Chronic Hepatitis C: A Cost Comparison of the Combination Simeprevir Plus Sofosbuvir vs. Protease-Inhibitor-Based Triple Therapy.

PubMed

Langness, Jacob A; Tabano, David; Wieland, Amanda; Tise, Sarah; Pratt, Lindsay; Harrington, Lauren Ayres; Lin, Sonia; Ghuschcyan, Vahram; Nair, Kavita V; Everson, Gregory T

Interferon-free, multi-direct acting antiviral (DAA) therapy for chronic hepatitis C virus (HCV) infection is highly effective and well tolerated, but costly. To gain perspective on the evolving economics of HCV therapy, we compared the cost per cure of a multi-DAA regimen with the prior standard of triple therapy. Patients infected with HCV genotype 1 who were treated through the University of Colorado Hepatology Clinic between May 2011 and December 2014 comprised the study population. The multi-DAA regimen of simeprevir plus sofosbuvir (SMV/SOF) was compared to the triple therapy regimen consisting of peginterferon and ribavirin, with either boceprevir or telaprevir (TT). Sustained-virologic response (SVR) rates, total costs per treatment and adverse events were recorded. Total cost per SVR were compared for the two treatments, controlling for patient demographics and clinical characteristics. One hundred eighty-three patients received SMV/SOF (n = 70) or TT (n = 113). Patients receiving SMV/SOF were older, more treatment experienced, and had a higher stage of fibrosis. SVRs were 86% and 59%, average total costs per patient were $152,775 and $95,943, and average total costs per SVR were $178,237 vs. $161,813.49 for SMV/SOF and TT groups, respectively. Medication costs accounted for 98% of SMV/SOF and 85% of TT treatment costs. The high cure rate of multi-DAA treatment of HCV is offset by the high costs of the DAAs, such that the cost per cure from TT to multi-DAA therapy has been relatively constant. In order to cure more patients, either additional financial resources will need to be allocated to the treatment of HCV or drug costs will need to be reduced.

Minimum target prices for production of direct-acting antivirals and associated diagnostics to combat hepatitis C virus

PubMed Central

van de Ven, Nikolien; Fortunak, Joe; Simmons, Bryony; Ford, Nathan; Cooke, Graham S; Khoo, Saye; Hill, Andrew

2015-01-01

Combinations of direct-acting antivirals (DAAs) can cure hepatitis C virus (HCV) in the majority of treatment-naïve patients. Mass treatment programs to cure HCV in developing countries are only feasible if the costs of treatment and laboratory diagnostics are very low. This analysis aimed to estimate minimum costs of DAA treatment and associated diagnostic monitoring. Clinical trials of HCV DAAs were reviewed to identify combinations with consistently high rates of sustained virological response across hepatitis C genotypes. For each DAA, molecular structures, doses, treatment duration, and components of retrosynthesis were used to estimate costs of large-scale, generic production. Manufacturing costs per gram of DAA were based upon treating at least 5 million patients per year and a 40% margin for formulation. Costs of diagnostic support were estimated based on published minimum prices of genotyping, HCV antigen tests plus full blood count/clinical chemistry tests. Predicted minimum costs for 12-week courses of combination DAAs with the most consistent efficacy results were: US$122 per person for sofosbuvir+daclatasvir; US$152 for sofosbuvir+ribavirin; US$192 for sofosbuvir+ledipasvir; and US$115 for MK-8742+MK-5172. Diagnostic testing costs were estimated at US$90 for genotyping US$34 for two HCV antigen tests and US$22 for two full blood count/clinical chemistry tests. Conclusions: Minimum costs of treatment and diagnostics to cure hepatitis C virus infection were estimated at US$171-360 per person without genotyping or US$261-450 per person with genotyping. These cost estimates assume that existing large-scale treatment programs can be established. (Hepatology 2015;61:1174–1182) PMID:25482139

Minimum target prices for production of direct-acting antivirals and associated diagnostics to combat hepatitis C virus.

PubMed

van de Ven, Nikolien; Fortunak, Joe; Simmons, Bryony; Ford, Nathan; Cooke, Graham S; Khoo, Saye; Hill, Andrew

2015-04-01

Combinations of direct-acting antivirals (DAAs) can cure hepatitis C virus (HCV) in the majority of treatment-naïve patients. Mass treatment programs to cure HCV in developing countries are only feasible if the costs of treatment and laboratory diagnostics are very low. This analysis aimed to estimate minimum costs of DAA treatment and associated diagnostic monitoring. Clinical trials of HCV DAAs were reviewed to identify combinations with consistently high rates of sustained virological response across hepatitis C genotypes. For each DAA, molecular structures, doses, treatment duration, and components of retrosynthesis were used to estimate costs of large-scale, generic production. Manufacturing costs per gram of DAA were based upon treating at least 5 million patients per year and a 40% margin for formulation. Costs of diagnostic support were estimated based on published minimum prices of genotyping, HCV antigen tests plus full blood count/clinical chemistry tests. Predicted minimum costs for 12-week courses of combination DAAs with the most consistent efficacy results were: US$122 per person for sofosbuvir+daclatasvir; US$152 for sofosbuvir+ribavirin; US$192 for sofosbuvir+ledipasvir; and US$115 for MK-8742+MK-5172. Diagnostic testing costs were estimated at US$90 for genotyping US$34 for two HCV antigen tests and US$22 for two full blood count/clinical chemistry tests. Minimum costs of treatment and diagnostics to cure hepatitis C virus infection were estimated at US$171-360 per person without genotyping or US$261-450 per person with genotyping. These cost estimates assume that existing large-scale treatment programs can be established. © 2014 The Authors. Hepatology published by Wiley Periodicals, Inc., on behalf of the American Association for the Study of Liver Diseases.

Extravehicular Activity (EVA) Power, Avionics, and Software (PAS) 101

NASA Technical Reports Server (NTRS)

Irimies, David

2011-01-01

EVA systems consist of a spacesuit or garment, a PLSS, a PAS system, and spacesuit interface hardware. The PAS system is responsible for providing power for the suit, communication of several types of data between the suit and other mission assets, avionics hardware to perform numerous data display and processing functions, and information systems that provide crewmembers data to perform their tasks with more autonomy and efficiency. Irimies discussed how technology development efforts have advanced the state-of-the-art in these areas and shared technology development challenges.

Space tug point design study. Volume 3: Design definition. Part 1: Propulsion and mechanical, avionics, thermal control and electrical power subsystems

NASA Technical Reports Server (NTRS)

1973-01-01

A study was conducted to determine the configuration and performance of a space tug. Details of the space tug systems are presented to include: (1) propulsion systems, (2) avionics, (3) thermal control, and (4) electric power subsystems. The data generated include engineering drawings, schematics, subsystem operation, and component description. Various options investigated and the rational for the point design selection are analyzed.

An independent review of the Multi-Path Redundant Avionics Suite (MPRAS) architecture assessment and characterization report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnson, M.R.

1991-02-01

In recent years the NASA Langley Research Center has funded several contractors to conduct conceptual designs defining architectures for fault tolerant computer systems. Such a system is referred to as a Multi-Path Redundant Avionics Suite (MPRAS), and would form the basis for avionics systems that would be used in future families of space vehicles in a variety of missions. The principal contractors were General Dynamics, Boeing, and Draper Laboratories. These contractors participated in a series of review meetings, and submitted final reports defining their candidate architectures. NASA then commissioned the Research Triangle Institute (RTI) to perform an assessment of thesemore » architectures to identify strengths and weaknesses of each. This report is a separate, independent review of the RTI assessment, done primarily to assure that the assessment was comprehensive and objective. The report also includes general recommendations relative to further MPRAS development.« less

A Database as a Service for the Healthcare System to Store Physiological Signal Data.

PubMed

Chang, Hsien-Tsung; Lin, Tsai-Huei

2016-01-01

Wearable devices that measure physiological signals to help develop self-health management habits have become increasingly popular in recent years. These records are conducive for follow-up health and medical care. In this study, based on the characteristics of the observed physiological signal records- 1) a large number of users, 2) a large amount of data, 3) low information variability, 4) data privacy authorization, and 5) data access by designated users-we wish to resolve physiological signal record-relevant issues utilizing the advantages of the Database as a Service (DaaS) model. Storing a large amount of data using file patterns can reduce database load, allowing users to access data efficiently; the privacy control settings allow users to store data securely. The results of the experiment show that the proposed system has better database access performance than a traditional relational database, with a small difference in database volume, thus proving that the proposed system can improve data storage performance.

Unmanned Aircraft Systems in the National Airspace System: A Formal Methods Perspective

NASA Technical Reports Server (NTRS)

Munoz, Cesar A.; Dutle, Aaron; Narkawicz, Anthony; Upchurch, Jason

2016-01-01

As the technological and operational capabilities of unmanned aircraft systems (UAS) have grown, so too have international efforts to integrate UAS into civil airspace. However, one of the major concerns that must be addressed in realizing this integration is that of safety. For example, UAS lack an on-board pilot to comply with the legal requirement that pilots see and avoid other aircraft. This requirement has motivated the development of a detect and avoid (DAA) capability for UAS that provides situational awareness and maneuver guidance to UAS operators to aid them in avoiding and remaining well clear of other aircraft in the airspace. The NASA Langley Research Center Formal Methods group has played a fundamental role in the development of this capability. This article gives a selected survey of the formal methods work conducted in support of the development of a DAA concept for UAS. This work includes specification of low-level and high-level functional requirements, formal verification of algorithms, and rigorous validation of software implementations.

A Database as a Service for the Healthcare System to Store Physiological Signal Data

PubMed Central

Lin, Tsai-Huei

2016-01-01

Wearable devices that measure physiological signals to help develop self-health management habits have become increasingly popular in recent years. These records are conducive for follow-up health and medical care. In this study, based on the characteristics of the observed physiological signal records– 1) a large number of users, 2) a large amount of data, 3) low information variability, 4) data privacy authorization, and 5) data access by designated users—we wish to resolve physiological signal record-relevant issues utilizing the advantages of the Database as a Service (DaaS) model. Storing a large amount of data using file patterns can reduce database load, allowing users to access data efficiently; the privacy control settings allow users to store data securely. The results of the experiment show that the proposed system has better database access performance than a traditional relational database, with a small difference in database volume, thus proving that the proposed system can improve data storage performance. PMID:28033415

Wheat seed weight and quality differ temporally in sensitivity to warm or cool conditions during seed development and maturation

PubMed Central

Nasehzadeh, M

2017-01-01

Abstract Background and aims Short periods of extreme temperature may affect wheat (Triticum aestivum) seed weight, but also quality. Temporal sensitivity to extreme temperature during seed development and maturation was investigated. Methods Plants of ‘Tybalt’ grown at ambient temperature were moved to growth cabinets at 29/20°C or 34/20°C (2010), or 15/10°C or 34/20°C (2011), for successive 7-d periods from 7 DAA (days after anthesis) onwards, and also 7–65 DAA in 2011. Seed samples were harvested serially and moisture content, weight, ability to germinate, subsequent longevity in air-dry storage and bread-making quality were determined. Key Results High temperature (34/20°C) reduced final seed weight, with greatest temporal sensitivity at 7–14 or 14–21 DAA. Several aspects of bread-making quality were also most sensitive to high temperature then, but whereas protein quality decreased protein and sulphur concentrations improved. Early exposure to high temperature provided earlier development of ability to germinate and tolerate desiccation, but had little effect on maximum germination capacity. All treatments at 15/10°C resulted in ability to germinate declining between 58 and 65 DAA. Early exposure to high temperature hastened improvement in seed storage longevity, but the subsequent decline in late maturation preceded that in the control. Long (7–65 DAA) exposure to 15/10°C disrupted the development of seed longevity, with no improvement after seed filling ended. Longevity improved during maturation drying in other treatments. Early (7–14 DAA) exposure to high temperature reduced and low temperature increased subsequent longevity at harvest maturity, whereas late (35 or 42–49 DAA) exposure to high temperature increased and low temperature reduced it. Conclusions Temporal sensitivity to extreme temperature was detected. It varied considerably amongst the contrasting seed variables investigated. Subsequent seed longevity at harvest maturity responded negatively to temperature early in development, but positively later in development and throughout maturation. PMID:28637252

Rapid reversal of innate immune dysregulation in blood of patients and livers of humanized mice with HCV following DAA therapy

PubMed Central

Burchill, Matthew A.; Roby, Justin A.; Crochet, Nanette; Wind-Rotolo, Megan; Stone, Amy E.; Edwards, Michael G.; Dran, Rachael J.; Kriss, Michael S.; Gale, Michael

2017-01-01

Chronic hepatitis C virus (HCV) infection results in sustained immune activation in both the periphery and hepatic tissue. HCV infection induces innate immune signaling that is responsible for recognition of dsRNA, leading to activation of transcription factors and production of Type I and III IFNs, as well as pro-inflammatory cytokines and chemokines. Continued activation of host-immune mediated inflammation is thought to contribute to pathologic changes that result in progressive hepatic fibrosis. The current standard treatment for chronic HCV infection is directly-acting antivirals (DAAs), which have provided the unique opportunity to determine whether successful, rapid treatment-induced eradication of viral RNA normalizes the dysregulated antiviral innate immune response in patients chronically infected with HCV. Results First, in patients receiving two different combinations of DAAs, we found that DAAs induced not only rapid viral clearance, but also a re-setting of antiviral immune responses in the peripheral blood. Specifically, we see a rapid decline in the expression of genes associated with chronic IFN stimulation (IFIT3, USP18, IFIT1) as well as a rapid decline in genes associated with inflammation (IL1β, CXCL10, CXCL11) in the peripheral blood that precedes the complete removal of virus from the blood. Interestingly, this rapid reversal of innate immune activation was not seen in patients who successfully clear chronic HCV infection using IFN-based therapy. Next, using a novel humanized mouse model (Fah-/-RAG2-/-IL2rgnull—FRG), we assessed the changes that occur in the hepatic tissue following DAA treatment. DAA-mediated rapid HCV clearance resulted in blunting of the expression of proinflammatory responses while functionally restoring the RIG-I/MAVS axis in the liver of humanized mice. Conclusions Collectively, our data demonstrate that the rapid viral clearance following treatment with DAAs results in the rebalancing of innate antiviral response in both the peripheral blood and the liver as well as enhanced antiviral signaling within previously infected hepatocytes. PMID:29040318

Hepatocellular carcinoma decreases the chance of successful hepatitis C virus therapy with direct-acting antivirals.

PubMed

Prenner, Stacey B; VanWagner, Lisa B; Flamm, Steven L; Salem, Riad; Lewandowski, Robert J; Kulik, Laura

2017-06-01

The approval of all-oral direct-acting antiviral (DAA) regimens for the treatment of hepatitis C virus (HCV) has led to the expansion of therapy to include patients with cirrhosis who have hepatocellular carcinoma (HCC). Data on the use of DAAs in HCV+ patients with HCC is limited. The aim of this study was to assess the efficacy of all-oral-DAA regimens in HCV+ cirrhotic patients who have or had HCC compared to those without HCC. A retrospective cohort study was conducted on all cirrhotic patients who were treated for HCV with DAAs at our institution between January 2014 and November 2015. A total of 421 HCV+ patients with cirrhosis were identified, of whom 33% had active or a history of HCC. Failure to achieve sustained virologic response (SVR) occurred in 21% of patients with HCC compared to 12% of patients without HCC (p=0.009). Of the 29 patients with HCC who did not achieve SVR, 27 (93%) occurred when an active tumor was present. DAA therapy in the presence of an inactive tumor or after removal of tumor (resection/transplant) resulted in excellent SVR rates, similar to those without HCC (p<0.0001). In multivariable analysis, the primary predictor of DAA treatment failure was the presence of active HCC at the time of HCV treatment initiation (adjusted odds ratio=8.5, 95% confidence interval=3.90-18.49). The presence of active HCC tumor at the initiation of HCV therapy is significantly associated with all-oral DAA treatment failure. HCV treatment after curative therapies for HCC resulted in excellent SVR. The new medications for hepatitis C have excellent cure rates. However, our study shows that in patients with both liver cancer and hepatitis C, they do not achieve these cure rates. Patients with liver cancer are almost 8 times more likely to fail hepatitis C treatment than patients without liver cancer. Copyright © 2017 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

UAS Well Clear Recovery Against Non-Cooperative Intruders Using Vertical Maneuvers

NASA Technical Reports Server (NTRS)

Cone, Andrew C.; Thipphavong, David; Lee, Seung Man; Santiago, Confesor

2017-01-01

This paper documents a study that drove the development of a mathematical expression in the detect-and-avoid (DAA) minimum operational performance standards (MOPS) for unmanned aircraft systems (UAS). This equation describes the conditions under which vertical maneuver guidance should be provided during recovery of DAA well clear separation with a non-cooperative VFR aircraft. Although the original hypothesis was that vertical maneuvers for DAA well clear recovery should only be offered when sensor vertical rate errors are small, this paper suggests that UAS climb and descent performance should be considered-in addition to sensor errors for vertical position and vertical rate-when determining whether to offer vertical guidance. A fast-time simulation study involving 108,000 encounters between a UAS and a non-cooperative visual-flight-rules aircraft was conducted. Results are presented showing that, when vertical maneuver guidance for DAA well clear recovery was suppressed, the minimum vertical separation increased by roughly 50 feet (or horizontal separation by 500 to 800 feet). However, the percentage of encounters that had a risk of collision when performing vertical well clear recovery maneuvers was reduced as UAS vertical rate performance increased and sensor vertical rate errors decreased. A class of encounter is identified for which vertical-rate error had a large effect on the efficacy of horizontal maneuvers due to the difficulty of making the correct left/right turn decision: crossing conflict with intruder changing altitude. Overall, these results support logic that would allow vertical maneuvers when UAS vertical performance is sufficient to avoid the intruder, based on the intruder's estimated vertical position and vertical rate, as well as the vertical rate error of the UAS' sensor.

Contribution of bacterial cells to lacustrine organic matter based on amino sugars and D-amino acids

NASA Astrophysics Data System (ADS)

Carstens, Dörte; Köllner, Krista E.; Bürgmann, Helmut; Wehrli, Bernhard; Schubert, Carsten J.

2012-07-01

Amino sugars (ASs), D-amino acids (D-AAs), and bacterial cell counts were measured in two Swiss lakes to study the contribution of bacterial cells to organic matter (OM) and the fate of ASs and bacterial amino biomarkers during OM degradation. Concentrations of individual ASs (glucosamine, galactosamine, muramic acid, and mannosamine) in the particulate and total OM pools were analyzed in water-column profiles of Lake Brienz (oligotrophic and oxic throughout the entire water column) and Lake Zug (eutrophic, stratified, and permanently anoxic below 170 m) in spring and in fall. Generally, carbon-normalized AS concentrations decreased with water depth, indicating the preferential decomposition of ASs. For Lake Brienz the relative loss of particulate ASs was higher than in Lake Zug, suggesting enhanced AS turnover in an oligotrophic environment. AS ratio changes in the water column revealed a replacement of plankton biomass with OM from heterotrophic microorganisms with increasing water depth. Similar to the ASs, highest carbon normalized D-AA concentrations were found in the upper water column with decreasing concentrations with depth and an increase close to the sediments. In Lake Zug, an increase in the percentage of D-AAs also showed the involvement of bacteria in OM degradation. Estimations of OM derived from bacterial cells using cell counts and the bacterial biomarkers muramic acid and D-AAs gave similar results. For Lake Brienz 0.2-14% of the organic carbon pool originated from bacterial cells, compared to only 0.1-5% in Lake Zug. Based on our estimates, muramic acid appeared primarily associated with bacterial biomass and not with refractory bacterial necromass. Our study underscores that bacteria are not only important drivers of OM degradation in lacustrine systems, they also represent a significant source of OM themselves, especially in oligotrophic lakes.

Interferon-free therapy in hepatitis C virus (HCV) monoinfected and HCV/HIV coinfected patients: effect on cognitive function, fatigue, and mental health.

PubMed

Kleefeld, Felix; Heller, Sophie; Ingiliz, Patrick; Jessen, Heiko; Petersen, Anders; Kopp, Ute; Kraft, Antje; Hahn, Katrin

2018-05-21

The efficacy and safety of interferon-free therapies for hepatitis C virus (HCV) infection have been reported. Considering the accumulating evidence for a direct central nervous system infection by HCV, we aim to evaluate the effect of direct acting antivirals (DAA) therapy on cognitive function in HCV patients. We conducted a longitudinal analysis of the cognitive performance of 22 patients (8 HCV+, 14 HCV+/HIV+) who completed neuropsychological testing at baseline and at week 12 after DAA therapy. In 20 patients, we analyzed specific attention parameters derived from an experimental testing based on the Theory of Visual Attention (TVA). Depression, fatigue, and mental health were assessed as patient reported outcomes. At baseline, 54.5% of the patients met the criteria for cognitive impairment and 40% showed impairment in TVA parameters. Follow-up analysis revealed significant improvements in the domains of visual memory/learning, executive functions, verbal fluency, processing speed, and motor skills but not in verbal learning and attention/working memory. We did not observe significant improvement in visual attention measured by TVA. Fatigue and mental health significantly improved at follow-up. Our findings indicate that successful DAA treatment leads to cognitive improvements in several domains measured by standard neuropsychological testing. The absence of improvement in TVA parameters and of significant improvement in the domain of attention/working memory might reflect the persistence of specific cognitive deficits after HCV eradication. In summary, DAA treatment seems to have a positive effect on some cognitive domains and leads to an improvement in mental health and fatigue in HCV-infected patients.

Introduction of the second-generation direct-acting antivirals (DAAs) in chronic hepatitis C: a register-based study in Sweden.

PubMed

Frisk, P; Aggefors, K; Cars, T; Feltelius, N; Loov, S A; Wettermark, B; Weiland, O

2018-07-01

Introduction of the direct-acting antivirals (DAAs) for treatment of chronic hepatitis C (CHC) infection has been challenging in all health systems. In Sweden, a national protocol for managed introduction was developed. It was optional, but all county councils agreed to implement and follow it. The purpose of this study was to study (a) cure rates among all patients initiated on treatment in 2014-2015, (b) prescribers' adherence to the drug recommendations and treatment eligibility criteria in the protocol, and (c) introduction rate in the six Swedish healthcare regions. A cross-sectional study where national data from the Prescribed Drug Register and the quality register InfCare Hepatitis defined the study population, and clinical data from the Patient Register and InfCare Hepatitis were used to monitor outcomes. Descriptive statistics were used. A total of 3447 patients were initiated on treatment during 2014-2015. The overall cure rate, based on data from 85% of the cohort, was 96%, with variation between genotypes. Adherence to drug recommendations increased over time and varied between 43.2 and 94.2%. Adherence to the treatment eligibility criteria was initially 80% and increased to 87% when treatment restrictions were widened. The introduction rate differed initially between the regions and reached stable levels 15-18 months after the launch of the first DAA. The estimated overall cure rate was 96%, with some variations between genotypes. A high level of adherence to the introduction protocol as well as similar introduction rates in the health care regions indicate that the introduction protocol, alongside with other measures taken, contributed considerably to a rapid uptake and equal distribution of DAAs in Sweden.

Curing the historically incurable: treatment success with ledipasvir/sofosbuvir for chronic hepatitis C virus in a heavily treatment-experienced individual.

PubMed

Johnson, S W; Davis, M M; Stever, L M; Priest, D H

2016-12-01

Significant progression in the treatment of chronic hepatitis C virus has been made with the introduction of direct-acting antivirals (DAAs). However, limited data are available for the retreatment of individuals who have failed multiple prior DAAs. We report a single case of an individual who was unsuccessfully treated with five prior hepatitis C virus treatment regimens including simeprevir plus sofosbuvir who was successfully cured after treatment with ledipasvir/sofosbuvir. Ledipasvir/sofosbuvir may be an option for treating patients who have failed multiple prior DAA regimens; however, further research is warranted. © 2016 John Wiley & Sons Ltd.

Air Force highly integrated photonics program: development and demonstration of an optically transparent fiber optic network for avionics applications

NASA Astrophysics Data System (ADS)

Whaley, Gregory J.; Karnopp, Roger J.

2010-04-01

The goal of the Air Force Highly Integrated Photonics (HIP) program is to develop and demonstrate single photonic chip components which support a single mode fiber network architecture for use on mobile military platforms. We propose an optically transparent, broadcast and select fiber optic network as the next generation interconnect on avionics platforms. In support of this network, we have developed three principal, single-chip photonic components: a tunable laser transmitter, a 32x32 port star coupler, and a 32 port multi-channel receiver which are all compatible with demanding avionics environmental and size requirements. The performance of the developed components will be presented as well as the results of a demonstration system which integrates the components into a functional network representative of the form factor used in advanced avionics computing and signal processing applications.

Human Exploration and Avionic Technology Challenges

NASA Technical Reports Server (NTRS)

Benjamin, Andrew L.

2005-01-01

For this workshop, I will identify critical avionic gaps, enabling technologies, high-pay off investment opportunities, promising capabilities, and space applications for human lunar and Mars exploration. Key technology disciplines encompass fault tolerance, miniaturized instrumentation sensors, MEMS-based guidance, navigation, and controls, surface communication networks, and rendezvous and docking. Furthermore, I will share bottom-up strategic planning relevant to manned mission -driven needs. Blending research expertise, facilities, and personnel with internal NASA is vital to stimulating collaborative technology solutions that achieve NASA grand vision. Retaining JSC expertise in unique and critical areas is paramount to our long-term success. Civil servants will maintain key roles in setting technology agenda, ensuring quality results, and integrating technologies into avionic systems and manned missions. Finally, I will present to NASA, academia, and the aerospace community some on -going and future advanced avionic technology programs and activities that are relevant to our mission goals and objectives.

Evaluating Data Abstraction Assistant, a novel software application for data abstraction during systematic reviews: protocol for a randomized controlled trial.

PubMed

Saldanha, Ian J; Schmid, Christopher H; Lau, Joseph; Dickersin, Kay; Berlin, Jesse A; Jap, Jens; Smith, Bryant T; Carini, Simona; Chan, Wiley; De Bruijn, Berry; Wallace, Byron C; Hutfless, Susan M; Sim, Ida; Murad, M Hassan; Walsh, Sandra A; Whamond, Elizabeth J; Li, Tianjing

2016-11-22

Data abstraction, a critical systematic review step, is time-consuming and prone to errors. Current standards for approaches to data abstraction rest on a weak evidence base. We developed the Data Abstraction Assistant (DAA), a novel software application designed to facilitate the abstraction process by allowing users to (1) view study article PDFs juxtaposed to electronic data abstraction forms linked to a data abstraction system, (2) highlight (or "pin") the location of the text in the PDF, and (3) copy relevant text from the PDF into the form. We describe the design of a randomized controlled trial (RCT) that compares the relative effectiveness of (A) DAA-facilitated single abstraction plus verification by a second person, (B) traditional (non-DAA-facilitated) single abstraction plus verification by a second person, and (C) traditional independent dual abstraction plus adjudication to ascertain the accuracy and efficiency of abstraction. This is an online, randomized, three-arm, crossover trial. We will enroll 24 pairs of abstractors (i.e., sample size is 48 participants), each pair comprising one less and one more experienced abstractor. Pairs will be randomized to abstract data from six articles, two under each of the three approaches. Abstractors will complete pre-tested data abstraction forms using the Systematic Review Data Repository (SRDR), an online data abstraction system. The primary outcomes are (1) proportion of data items abstracted that constitute an error (compared with an answer key) and (2) total time taken to complete abstraction (by two abstractors in the pair, including verification and/or adjudication). The DAA trial uses a practical design to test a novel software application as a tool to help improve the accuracy and efficiency of the data abstraction process during systematic reviews. Findings from the DAA trial will provide much-needed evidence to strengthen current recommendations for data abstraction approaches. The trial is registered at National Information Center on Health Services Research and Health Care Technology (NICHSR) under Registration # HSRP20152269: https://wwwcf.nlm.nih.gov/hsr_project/view_hsrproj_record.cfm?NLMUNIQUE_ID=20152269&SEARCH_FOR=Tianjing%20Li . All items from the World Health Organization Trial Registration Data Set are covered at various locations in this protocol. Protocol version and date: This is version 2.0 of the protocol, dated September 6, 2016. As needed, we will communicate any protocol amendments to the Institutional Review Boards (IRBs) of Johns Hopkins Bloomberg School of Public Health (JHBSPH) and Brown University. We also will make appropriate as-needed modifications to the NICHSR website in a timely fashion.

USAF Development Of Optical Correlation Missile Guidance

NASA Astrophysics Data System (ADS)

Kaehr, Ronald; Spector, Marvin

1980-12-01

In 1965, the Advanced Development Program (ADP)-679A of the Avionics Laboratory initiated development of guidance systems for stand-off tactical missiles. Employing project engineering support from the Aeronautical Systems Division, WPAFB, the Avionics Laboratory funded multiple terminal guidance concepts and related midcourse navigation technology. Optical correlation techniques which utilize prestored reference information for autonomous target acquisition offered the best near-term opportunity for meeting mission goals. From among the systems studied and flight tested, Aimpoint* optical area guidance provided the best and most consistent performance. Funded development by the Air Force ended in 1974 with a MK-84 guided bomb drop test demonstration at White Sands Missile Range and the subsequent transfer of the tactical missile guidance development charter to the Air Force Armament Laboratory, Eglin AFB. A historical review of optical correlation development within the Avionics Laboratory is presented. Evolution of the Aimpoint system is specifically addressed. Finally, a brief discussion of trends in scene matching technology is presented.

Flight elements: Advanced avionics systems architectures

NASA Technical Reports Server (NTRS)

1990-01-01

Space transportation objectives are associated with transporting material from Earth to orbit, interplanetary travel, and planetary landing. The objectives considered herein are associated with Earth to orbit transportation. Many good avionics architectural features will support all phases of space transportation, but interplanetary transportation poses significantly different problems such as long mission time with high reliability, unattended operation, and many different opportunities such as long nonoperational flight segments that can be used for equipment fault diagnosis and repair. Fault tolerance can be used to permit continued operation with faulty units, not only during launch but also, and perhaps with more impact, during prelaunch activities. Avionics systems are entering a phase of development where the traditional approaches to satisfactory systems based on engineering judgement and thorough testing will alone no longer be adequate to assure that the required system performance can be obtained. A deeper understanding will be required to make the effects of obscure design decisions clear at a level where their impact can be properly judged.

Preliminary design document: Ground based testbed for avionics systems

NASA Technical Reports Server (NTRS)

1989-01-01

The design and interface requirements for an avionics Ground Based Test bed (GBT) to support Heavy Lift Cargo Vehicles (HLCV) is presented. It also contains data on the vehicle subsystem configurations that are to be supported during their early, pre-PDR developmental phases. Several emerging technologies are also identified for support. A Preliminary Specification Tree is also presented.

Fiber-Optic Network Architectures for Onboard Avionics Applications Investigated

NASA Technical Reports Server (NTRS)

Nguyen, Hung D.; Ngo, Duc H.

2003-01-01

This project is part of a study within the Advanced Air Transportation Technologies program undertaken at the NASA Glenn Research Center. The main focus of the program is the improvement of air transportation, with particular emphasis on air transportation safety. Current and future advances in digital data communications between an aircraft and the outside world will require high-bandwidth onboard communication networks. Radiofrequency (RF) systems, with their interconnection network based on coaxial cables and waveguides, increase the complexity of communication systems onboard modern civil and military aircraft with respect to weight, power consumption, and safety. In addition, safety and reliability concerns from electromagnetic interference between the RF components embedded in these communication systems exist. A simple, reliable, and lightweight network that is free from the effects of electromagnetic interference and capable of supporting the broadband communications needs of future onboard digital avionics systems cannot be easily implemented using existing coaxial cable-based systems. Fiber-optical communication systems can meet all these challenges of modern avionics applications in an efficient, cost-effective manner. The objective of this project is to present a number of optical network architectures for onboard RF signal distribution. Because of the emergence of a number of digital avionics devices requiring high-bandwidth connectivity, fiber-optic RF networks onboard modern aircraft will play a vital role in ensuring a low-noise, highly reliable RF communication system. Two approaches are being used for network architectures for aircraft onboard fiber-optic distribution systems: a hybrid RF-optical network and an all-optical wavelength division multiplexing (WDM) network.

AVION: A detailed report on the preliminary design of a 79-passenger, high-efficiency, commercial transport aircraft

NASA Technical Reports Server (NTRS)

Mayfield, William; Perkins, Brett; Rogan, William; Schuessler, Randall; Stockert, Joe

1990-01-01

The Avion is the result of an investigation into the preliminary design for a high-efficiency commercial transport aircraft. The Avion is designed to carry 79 passengers and a crew of five through a range of 1,500 nm at 455 kts (M=0.78 at 32,000 ft). It has a gross take-off weight of 77,000 lb and an empty weight of 42,400 lb. Currently there are no American-built aircraft designed to fit the 60 to 90 passenger, short/medium range marketplace. The Avion gathers the premier engineering achievements of flight technology and integrates them into an aircraft which will challenge the current standards of flight efficiency, reliability, and performance. The Avion will increase flight efficiency through reduction of structural weight and the improvement of aerodynamic characteristics and propulsion systems. Its design departs from conventional aircraft design tradition with the incorporation of a three-lifting-surface (or tri-wing) configuration. Further aerodynamic improvements are obtained through modest main wing forward sweeping, variable incidence canards, aerodynamic coupling between the canard and main wing, leading edge extensions, winglets, an aerodynamic tailcone, and a T-tail empennage. The Avion is propelled by propfans, which are one of the most promising developments for raising propulsive efficiencies at high subsonic Mach numbers. Special attention is placed on overall configuration, fuselage layout, performance estimations, component weight estimations, and planform design. Leading U.S. technology promises highly efficient flight for the 21st century; the Avion will fulfill this promise to passenger transport aviation.

How the Navy Can Use Open Systems Architecture to Revolutionize Capability Acquisition: The Naval OSA Strategy Can Yield Multiple Benefits

DTIC Science & Technology

2015-04-30

and Data Rights Team, which supports the Better Buying Power initiatives. Robert Sweeney—is the Lead Avionics Architect for Naval Air Systems...open architecture strategies for naval aviation. Sweeney was previously employed by Rockwell Collins as a software engineer for avionics . He earned his...the rapid replacement and upgrade of capabilities to address warfighter needs (Assistant Secretary of the Navy for Research, Development, and

Regulatory Compliance in Multi-Tier Supplier Networks

NASA Technical Reports Server (NTRS)

Goossen, Emray R.; Buster, Duke A.

2014-01-01

Over the years, avionics systems have increased in complexity to the point where 1st tier suppliers to an aircraft OEM find it financially beneficial to outsource designs of subsystems to 2nd tier and at times to 3rd tier suppliers. Combined with challenging schedule and budgetary pressures, the environment in which safety-critical systems are being developed introduces new hurdles for regulatory agencies and industry. This new environment of both complex systems and tiered development has raised concerns in the ability of the designers to ensure safety considerations are fully addressed throughout the tier levels. This has also raised questions about the sufficiency of current regulatory guidance to ensure: proper flow down of safety awareness, avionics application understanding at the lower tiers, OEM and 1st tier oversight practices, and capabilities of lower tier suppliers. Therefore, NASA established a research project to address Regulatory Compliance in a Multi-tier Supplier Network. This research was divided into three major study efforts: 1. Describe Modern Multi-tier Avionics Development 2. Identify Current Issues in Achieving Safety and Regulatory Compliance 3. Short-term/Long-term Recommendations Toward Higher Assurance Confidence This report presents our findings of the risks, weaknesses, and our recommendations. It also includes a collection of industry-identified risks, an assessment of guideline weaknesses related to multi-tier development of complex avionics systems, and a postulation of potential modifications to guidelines to close the identified risks and weaknesses.

Orion FSW V and V and Kedalion Engineering Lab Insight

NASA Technical Reports Server (NTRS)

Mangieri, Mark L.

2010-01-01

NASA, along with its prime Orion contractor and its subcontractor s are adapting an avionics system paradigm borrowed from the manned commercial aircraft industry for use in manned space flight systems. Integrated Modular Avionics (IMA) techniques have been proven as a robust avionics solution for manned commercial aircraft (B737/777/787, MD 10/90). This presentation will outline current approaches to adapt IMA, along with its heritage FSW V&V paradigms, into NASA's manned space flight program for Orion. NASA's Kedalion engineering analysis lab is on the forefront of validating many of these contemporary IMA based techniques. Kedalion has already validated many of the proposed Orion FSW V&V paradigms using Orion's precursory Flight Test Article (FTA) Pad Abort 1 (PA-1) program. The Kedalion lab will evolve its architectures, tools, and techniques in parallel with the evolving Orion program.

Modeling and Simulation Plans in Support of Low Cost, Size, Weight, and Power Surveillance Systems for Detecting and Tracking Non-Cooperative Aircraft

NASA Technical Reports Server (NTRS)

Wu, Gilbert; Santiago, Confesor

2017-01-01

RTCA Special Committee (SC) 228 has initiated a second phase for the development of minimum operational performance standards (MOPS) for UAS detect and avoid (DAA) systems. Technologies to enable UAS with less available Size, Weight, and Power (SWaP) will be considered. RTCA SC-228 has established sub-working groups and one of the sub-working groups is focused on aligning modeling and simulations activities across all participating committee members. This briefing will describe NASAs modeling and simulation plans for the development of performance standards for low cost, size, weight, and power (C-SWaP) surveillance systems that detect and track non-cooperative aircraft. The briefing will also describe the simulation platform NASA intends to use to support end-to-end verification and validation for these DAA systems. Lastly, the briefing will highlight the experiment plan for our first simulation study, and provide a high-level description of our future flight test plans. This briefing does not contain any results or data.

Gender-Specific Barriers to Self-Sufficiency among Former Supplemental Security Income Drug Addiction and Alcoholism Beneficiaries: Implications for Welfare-To-Work Programs and Services

PubMed Central

Hogan, Sean R; Unick, George J.; Speiglman, Richard; Norris, Jean C.

2011-01-01

This study examines barriers to economic self-sufficiency among a panel of 219 former Supplemental Security Income (SSI) drug addiction and alcoholism (DA&A) recipients following elimination of DA&A as an eligibility category for SSI disability benefits. Study participants were comprehensively surveyed at six measurement points following the policy change. Generalized estimating equations were used to examine full-sample and gender-specific barriers to economic self-sufficiency. Results indicate that access to transportation, age, and time are the strongest predictors of achieving self-sufficiency for both men and women leaving the welfare system. Gender-specific barriers are also identified. Future research needs to assess the generalizability of these results to other public assistance recipients. PMID:21625301

System requirements for head down and helmet mounted displays in the military avionics environment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Flynn, M.F.; Kalmanash, M.; Sethna, V.

1996-12-31

The introduction of flat panel display technologies into the military avionics cockpit is a challenging proposition, due to the very difficult system level requirements which must be met. These relate to environmental extremes (temperature and vibrational), sever ambient lighting conditions (10,000 fL to nighttime viewing), night vision system compatibility, and wide viewing angle. At the same time, the display system must be packaged in minimal space and use minimal power. The authors will present details on the display system requirements for both head down and helmet mounted systems, as well as information on how these challenges may be overcome.

Requirements-Based Conformance Testing of ARINC 653 Real-Time Operating Systems

NASA Astrophysics Data System (ADS)

Maksimov, Andrey

2010-08-01

Requirements-based testing is emphasized in avionics certification documents because this strategy has been found to be the most effective at revealing errors. This paper describes the unified requirements-based approach to the creation of conformance test suites for mission-critical systems. The approach uses formal machine-readable specifications of requirements and finite state machine model for test sequences generation on-the-fly. The paper also presents the test system for automated test generation for ARINC 653 services built on this approach. Possible application of the presented approach to various areas of avionics embedded systems testing is discussed.

State-of-the-art cockpit design for the HH-65A helicopters

NASA Technical Reports Server (NTRS)

Castleberry, D. E.; Mcelreath, M. Y.

1982-01-01

In the design of a HH-65A helicopter cockpit, advanced integrated electronics systems technology was employed to achieve several important goals for this multimission aircraft. They were: (1) integrated systems operation with consistent and simplified cockpit procedures; (2) mission-task-related cockpit displays and controls, and (3) reduced pilot instrument scan effort with excellent outside visibility. The integrated avionics system was implemented to depend heavily upon distributed but complementary processing, multiplex digital bus technology, and multifunction CRT controls and displays. This avionics system was completely flight tested and will soon enter operational service with the Coast Guard.

Integrated Power, Avionics, and Software (iPAS) Space Telecommunications Radio System (STRS) Radio User's Guide -- Advanced Exploration Systems (AES)

NASA Technical Reports Server (NTRS)

Roche, Rigoberto; Shalkhauser, Mary Jo Windmille

2017-01-01

The Integrated Power, Avionics and Software (IPAS) software defined radio (SDR) was implemented on the Reconfigurable, Intelligently-Adaptive Communication System (RAICS) platform, for radio development at NASA Johnson Space Center. Software and hardware description language (HDL) code were delivered by NASA Glenn Research Center for use in the IPAS test bed and for development of their own Space Telecommunications Radio System (STRS) waveforms on the RAICS platform. The purpose of this document is to describe how to setup and operate the IPAS STRS Radio platform with its delivered test waveform.

System data communication structures for active-control transport aircraft, volume 2

NASA Technical Reports Server (NTRS)

Hopkins, A. L.; Martin, J. H.; Brock, L. D.; Jansson, D. G.; Serben, S.; Smith, T. B.; Hanley, L. D.

1981-01-01

The application of communication structures to advanced transport aircraft are addressed. First, a set of avionic functional requirements is established, and a baseline set of avionics equipment is defined that will meet the requirements. Three alternative configurations for this equipment are then identified that represent the evolution toward more dispersed systems. Candidate communication structures are proposed for each system configuration, and these are compared using trade off analyses; these analyses emphasize reliability but also address complexity. Multiplex buses are recognized as the likely near term choice with mesh networks being desirable for advanced, highly dispersed systems.

Advanced fighter technology integration (AFTI)/F-16 Automated Maneuvering Attack System final flight test results

NASA Technical Reports Server (NTRS)

Dowden, Donald J.; Bessette, Denis E.

1987-01-01

The AFTI F-16 Automated Maneuvering Attack System has undergone developmental and demonstration flight testing over a total of 347.3 flying hours in 237 sorties. The emphasis of this phase of the flight test program was on the development of automated guidance and control systems for air-to-air and air-to-ground weapons delivery, using a digital flight control system, dual avionics multiplex buses, an advanced FLIR sensor with laser ranger, integrated flight/fire-control software, advanced cockpit display and controls, and modified core Multinational Stage Improvement Program avionics.

Integrated Target Acquisition and Fire Control Systems: Avionics Panel Symposium Held in Ottawa, Canada on 7-10 October 1991 (Systemes Integres d’Acquisition d’Objectifs et de Conduite de Tir)

DTIC Science & Technology

1992-02-01

Designation with the CL-227 Sea Sentinel 31 byH SotadS.Joes SESSION V - LONGER TERM SYSTEMS Avionic System Improvement Proposal for the TORNADO...18’s fire control capability to deliver some types of smart munitions. Yet we also noted that while we lacked the target designators and control...source of lines came qystems designed to deny the information about the tactical enemy the use of height. Sophisticated situation they are facing. Enemy

Space shuttle orbiter avionics software: Post review report for the entry FACI (First Article Configuration Inspection). [including orbital flight tests integrated system

NASA Technical Reports Server (NTRS)

Markos, H.

1978-01-01

Status of the computer programs dealing with space shuttle orbiter avionics is reported. Specific topics covered include: delivery status; SSW software; SM software; DL software; GNC software; level 3/4 testing; level 5 testing; performance analysis, SDL readiness for entry first article configuration inspection; and verification assessment.

2000 Digital Avionics Highlights

NASA Technical Reports Server (NTRS)

Polites, Michael E.

2000-01-01

This article summarizes the highlights of recent events and developments in digital avionics in commercial aviation, military systems, and space. This article is about 1,200 words long. Information for the article was collected from other NASA centers, DoD, and industry. All information was previously cleared by the originating organizations. Information for the article was also gathered from Aviation Week and Space Technology and similar sources.

Hardware survey for the avionics test bed

NASA Technical Reports Server (NTRS)

Cobb, J. M.

1981-01-01

A survey of maor hardware items that could possibly be used in the development of an avionics test bed for space shuttle attached or autonomous large space structures was conducted in NASA Johnson Space Center building 16. The results of the survey are organized to show the hardware by laboratory usage. Computer systems in each laboratory are described in some detail.

Sofosbuvir treatment and hepatitis C virus infection

PubMed Central

Nakamura, Masato; Kanda, Tatsuo; Haga, Yuki; Sasaki, Reina; Wu, Shuang; Nakamoto, Shingo; Yasui, Shin; Arai, Makoto; Imazeki, Fumio; Yokosuka, Osamu

2016-01-01

Hepatitis C virus (HCV) infection is a serious problem worldwide. The use of interferon-based therapy has made HCV eradication challenging. The recent appearance of direct-acting antiviral agents (DAAs) has changed HCV therapy. Combining the use of DAAs with peginterferon and ribavirin has improved treatment efficacy. Furthermore, the combination of different orally administered DAAs has enabled interferon-free therapy with much higher efficacy and safety. In particular, sofosbuvir, a nucleotide-based NS5B inhibitor, prevents HCV RNA synthesis by acting as a “chain terminator”. Treatment with sofosbuvir has attained an extremely high rate of sustained virologic response. The current review summarizes the efficacy and safety of sofosbuvir therapy. PMID:26839641

The Design of Model-Based Training Programs

NASA Technical Reports Server (NTRS)

Polson, Peter; Sherry, Lance; Feary, Michael; Palmer, Everett; Alkin, Marty; McCrobie, Dan; Kelley, Jerry; Rosekind, Mark (Technical Monitor)

1997-01-01

This paper proposes a model-based training program for the skills necessary to operate advance avionics systems that incorporate advanced autopilots and fight management systems. The training model is based on a formalism, the operational procedure model, that represents the mission model, the rules, and the functions of a modem avionics system. This formalism has been defined such that it can be understood and shared by pilots, the avionics software, and design engineers. Each element of the software is defined in terms of its intent (What?), the rationale (Why?), and the resulting behavior (How?). The Advanced Computer Tutoring project at Carnegie Mellon University has developed a type of model-based, computer aided instructional technology called cognitive tutors. They summarize numerous studies showing that training times to a specified level of competence can be achieved in one third the time of conventional class room instruction. We are developing a similar model-based training program for the skills necessary to operation the avionics. The model underlying the instructional program and that simulates the effects of pilots entries and the behavior of the avionics is based on the operational procedure model. Pilots are given a series of vertical flightpath management problems. Entries that result in violations, such as failure to make a crossing restriction or violating the speed limits, result in error messages with instruction. At any time, the flightcrew can request suggestions on the appropriate set of actions. A similar and successful training program for basic skills for the FMS on the Boeing 737-300 was developed and evaluated. The results strongly support the claim that the training methodology can be adapted to the cockpit.

A Library of Rad Hard Mixed-Voltage/Mixed-Signal Building Blocks for Integration of Avionics Systems for Deep Space

NASA Technical Reports Server (NTRS)

Mojarradi, M. M.; Blaes, B.; Kolawa, E. A.; Blalock, B. J.; Li, H. W.; Buck, K.; Houge, D.

2001-01-01

To build the sensor intensive system-on-a-chip for the next generation spacecrafts for deep space, Center for Integration of Space Microsystems at JPL (CISM) takes advantage of the lower power rating and inherent radiation resistance of Silicon on Insulator technology (SOI). We are developing a suite of mixed-voltage and mixed-signal building blocks in Honeywell's SOI process that can enable the rapid integration of the next generation avionics systems with lower power rating, higher reliability, longer life, and enhanced radiation tolerance for spacecrafts such as the Europa Orbiter and Europa Lander. The mixed-voltage building blocks are predominantly for design of adaptive power management systems. Their design centers around an LDMOS structure that is being developed by Honeywell, Boeing Corp, and the University of Idaho. The mixed-signal building blocks are designed to meet the low power, extreme radiation requirement of deep space applications. These building blocks are predominantly used to interface analog sensors to the digital CPU of the next generation avionics system on a chip. Additional information is contained in the original extended abstract.

Discovery and preclinical development of dasabuvir for the treatment of hepatitis C infection.

PubMed

El Kassas, Mohamed; Elbaz, Tamer; Hafez, Enas; Wifi, Mohamed Naguib; Esmat, Gamal

2017-06-01

Hepatitis C virus (HCV) is a leading cause of liver-related morbidity and mortality. Positively, the introduction of new directly-acting antivirals (DAAs) have led to dramatic improvements in response rates to antiviral therapy. Furthermore, newer generations of DAAs have demonstrated better safety profiles as well as efficacy than older generations. Current treatment recommendations are based on different combinations of DAAs. Current combination therapies rely on agents that target the different steps of viral replication by using different molecules from various DAAs families. Areas covered: In this review, the authors summarize data from of one of the recently developed NS5B polymerase inhibitors, dasabuvir, formerly known as ABT-333. Herein, the authors discuss the drug discovery data for dasabuvir including data from preclinical, toxicological resistance studies. The authors also review dasabuvir's clinical efficacy across various clinical challenges, in addition to its limitations in clinical practice. Expert opinion: Dasabuvir represents an important medical advance when used as a combination therapy for HCV. Unfortunately, it does present limitations like low genotypic coverage and further research is still required to address some of the lingering issues.

Involvement of abscisic acid in correlative control of flower abscission in soybean

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yarrow, G.L.

1985-01-01

Studies were carried out in three parts: (1) analysis of endogenous abscisic acid (ABA) in abscising and non-abscising flowers, (2) partitioning of radio-labelled ABA and photoassimilates within the soybean raceme, and (3) shading experiments, wherein endogenous levels, metabolism and partitioning of ABA were determined. Endogenous concentrations of ABA failed to show any consistent relationship to abscission of soybean flowers. Partitioning of radiolabelled ABA and photoassimilates displayed consistently higher sink strengths (% DPM) for both /sup 3/H-ABA and /sup 14/C-photoassimilates for non-abscising flowers than for abscising flowers within control racemes. Shading flowers with aluminum foil, 48 hrs prior to sampling, resultedmore » in lowered endogenous ABA concentrations at 12, 17 and 22 days after anthesis (DAA), but not at 0 or 4 DAA. No differences were found in the catabolism of /sup 3/H-ABA between shaded (abscising) and non-shaded (non-abscising) flowers. Reduced partitioning of ABA and photoassimilates to shaded flowers resulted when shades were applied at 0, 4, 12, and 17 DAA, but not at 22 DAA.« less

Direct anti-HCV agents

PubMed Central

Zhang, Xingquan

2015-01-01

Unlike human immunodeficiency virus (HIV) and hepatitis B virus (HBV), hepatitis C virus (HCV) infection is a curable disease. Current direct antiviral agent (DAA) targets are focused on HCV NS3/4A protein (protease), NS5B protein (polymerase) and NS5A protein. The first generation of DAAs includes boceprevir and telaprevir, which are protease inhibitors and were approved for clinical use in 2011. The cure rate for genotype 1 patients increased from 45% to 70% when boceprevir or telaprevir was added to standard PEG-IFN/ribavirin. More effective and less toxic second generation DAAs supplanted these drugs by 2013. The second generation of DAAs includes sofosbuvir (Sovaldi), simeprevir (Olysio), and fixed combination medicines Harvoni and Viekira Pak. These drugs increase cure rates to over 90% without the need for interferon and effectively treat all HCV genotypes. With these drugs the “cure HCV” goal has become a reality. Concerns remain about drug resistance mutations and the high cost of these drugs. The investigation of new HCV drugs is progressing rapidly; fixed dose combination medicines in phase III clinical trials include Viekirax, asunaprevir+daclatasvir+beclabuvir, grazoprevir+elbasvir and others. PMID:26904396

On Board Data Acquisition System with Intelligent Transducers for Unmanned Aerial Vehicles

NASA Astrophysics Data System (ADS)

Rochala, Zdzisław

2012-02-01

This report presents conclusions from research project no. ON50900363 conducted at the Mechatronics Department, Military University of Technology in the years 2007-2010. As the main object of the study involved the preparation of a concept and the implementation of an avionics data acquisition system intended for research during flight of unmanned aerial vehicles of the mini class, this article presents a design of an avionics system and describes equipment solutions of a distributed measurement system intended for data acquisition consisting of intelligent transducers. The data collected during a flight controlled by an operator confirmed proper operation of the individual components of the data acquisition system.

Modeling pilot interaction with automated digital avionics systems: Guidance and control algorithms for contour and nap-of-the-Earth flight

NASA Technical Reports Server (NTRS)

Hess, Ronald A.

1990-01-01

A collection of technical papers are presented that cover modeling pilot interaction with automated digital avionics systems and guidance and control algorithms for contour and nap-of-the-earth flight. The titles of the papers presented are as follows: (1) Automation effects in a multiloop manual control system; (2) A qualitative model of human interaction with complex dynamic systems; (3) Generalized predictive control of dynamic systems; (4) An application of generalized predictive control to rotorcraft terrain-following flight; (5) Self-tuning generalized predictive control applied to terrain-following flight; and (6) Precise flight path control using a predictive algorithm.

Hepatitis C and liver transplantation.

PubMed

Martini, Silvia

2018-06-01

Hepatitis C virus (HCV)-related liver disease represents the leading indication for liver transplantation (LT) in the USA and Europe and HCV recurrence is universal in recipients who are viremic at LT. Until a few years ago, pegylated-interferon in association with ribavirin was the only therapeutic strategy, usable only in compensated cirrhotic patients, in order to prevent post-LT viral recurrence. The recent advent of direct-acting antiviral agents (DAAs) has dramatically increased the chances of curative treatment for the transplant population and the debate about which should be the best time for treating the infection is still open: whether to pursue HCV eradication 1) before LT, in order to improve liver function, delist some patients and prevent graft infection; or 2) as early as possible after LT, rather than 3) waiting for hepatitis C recurrence before starting treatment. In addition, in the DAA era, the use of HCV-positive donors may represent a potential approach to safely expanding the donor pool. As more HCV patients achieve cure with DAA regimens, the LT trend for HCV in the future would be expected to mimic the trend observed for hepatitis B virus in the past decade and in the United States, during the DAA-period 2014-2015, the rate of LT wait-listing for HCV complicated by decompensated cirrhosis has already decreased by 32%. This review summarizes the published data and emphasizes DAA treatment applicability to patients with decompensated cirrhosis and to liver transplant recipients.

Novel insights into the effect of nitrogen on storage protein biosynthesis and protein body development in wheat caryopsis.

PubMed

Yu, Xurun; Chen, Xinyu; Wang, Leilei; Yang, Yang; Zhu, Xiaowei; Shao, Shanshan; Cui, Wenxue; Xiong, Fei

2017-04-01

Molecular and cytological mechanisms concerning the effects of nitrogen on wheat (Triticum aestivum L.) storage protein biosynthesis and protein body development remain largely elusive. We used transcriptome sequencing, proteomics techniques, and light microscopy to investigate these issues. In total, 2585 differentially expressed genes (DEGs) and 57 differentially expressed proteins (DEPs) were found 7 days after anthesis (DAA), and 2456 DEGs and 64 DEPs were detected 18 DAA after nitrogen treatment. Gene ontology terms related to protein biosynthesis processes enriched these numbers by 678 and 582 DEGs at 7 and 18 DAA, respectively. Further, 25 Kyoto Encyclopedia of Genes and Genomes pathways were involved in protein biosynthesis at both 7 and 18 DAA. DEPs related to storage protein biosynthesis contained gliadin and glutenin subunits, most of which were up-regulated after nitrogen treatment. Quantitative real-time PCR analysis indicated that some gliadin and glutenin subunit encoding genes were differentially expressed at 18 DAA. Structural observation revealed that wheat endosperm accumulated more and larger protein bodies after nitrogen treatment. Collectively, our findings suggest that nitrogen treatment enhances storage protein content, endosperm protein body quantity, and partial processing quality by altering the expression levels of certain genes involved in protein biosynthesis pathways and storage protein expression at the proteomics level. © The Author 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Dissipation and runoff transport of metazachlor herbicide in rapeseed cultivated and uncultivated plots in field conditions.

PubMed

Mantzos, Nikolaos; Hela, Dimitra; Karakitsou, Anastasia; Antonopoulou, Maria; Konstantinou, Ioannis

2016-10-01

The environmental fate of metazachlor herbicide was investigated under field conditions in rapeseed cultivated and uncultivated plots, over a period of 225 days. The cultivation was carried out in silty clay soil plots with two surface slopes, 1 and 5 %. The herbicide was detectable in soil up to 170 days after application (DAA), while the dissipation rate was best described by first-order kinetics and its half-life ranged between 10.92 and 12.68 days. The herbicide was detected in the soil layer of 10-20 cm from 5 to 48 DAA, and its vertical movement can be described by the continuous stirred tank reactor (CSTR) in series model. Relatively low amounts of metazachlor (less than 0.31 % of the initial applied active ingredient) were transferred by runoff water. More than 80 % of the total losses were transferred at the first runoff event (12 DAA), with herbicide concentrations in runoff water ranging between 70.14 and 79.67 μg L -1 . Minor amounts of the herbicide (less than 0.07 % of the initial applied active ingredient) were transferred by the sediment, with a maximum concentration of 0.57 μg g -1 (12 DAA), in plots with 5 % inclination. Finally, in rapeseed plants, metazachlor was detected only in the first sampling (28 DAA) at concentrations slightly higher than the limit of quantification; when in seeds, no residues of the herbicide were detected.

The elderly and direct antiviral agents: Constraint or challenge?

PubMed

Fabrizio, Claudia; Saracino, Annalisa; Scudeller, Luigia; Milano, Eugenio; Dell'Acqua, Raffaele; Bruno, Giuseppe; Lo Caputo, Sergio; Monno, Laura; Milella, Michele; Angarano, Gioacchino

2017-09-01

Direct antiviral agents (DAAs) for chronic hepatitis C showed great effectiveness and good safety profile. So far, few data are available about their use in elderly subjects. To assess management, safety and outcome of DAAs treatments in the elderly. This retrospective, single-centre study enrolled all patients aged ≥65 years, compared by age (group A: 65-74 years, group B: ≥75 years), who completed DAAs between February 2015-November 2016. Variables potentially associated to adverse events (AEs) were analyzed. Sustained virological response (SVR) was evaluated at 12-weeks follow-up. DAAs were administered to 221 patients aged ≥65 years (males: 112; group A: 130, group B: 91). Prescribed regimens were: sofosbuvir-based: 44 patients (19.9%), simeprevir-based: 25 (15%), ledipasvir-based: 49 (22.2%), daclatasvir-based: 12 (5.4%), paritaprevir/ritonavir+ombitasvir±dasabuvir: 91 (41.2%). Ribavirin was used in 121 patients. In 58 subjects co-medications were adjusted due to drug interactions. At least one AE occurred in 130 patients, including 13 SAEs, mainly in older subjects (p=0.04). Female sex (p=0.04), liver stiffness (p=0.023), use of simeprevir (p=0.03) and ribavirin (p=0.009) were associated with AEs. SVR-12 was achieved in 96,9% of subjects. A careful baseline evaluation and a strict monitoring allow to optimise management and outcome of DAAs in elderly. Copyright © 2017 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

Cricothyrotomy training increases adherence to the ASA difficult airway algorithm in a simulated crisis: a randomized controlled trial.

PubMed

You-Ten, Kong Eric; Bould, M Dylan; Friedman, Zeev; Riem, Nicole; Sydor, Devin; Boet, Sylvain

2015-05-01

Non-adherence to airway guidelines in a 'cannot intubate-cannot oxygenate' (CICO) crisis situation is associated with adverse patient outcomes. This study investigated the effects of hands-on training in cricothyrotomy on adherence to the American Society of Anesthesiologists difficult airway algorithm (ASA-DAA) during a simulated CICO scenario. A total of 21 postgraduate second-year anesthesia residents completed a pre-test teaching session during which they reviewed the ASA-DAA, became familiarized with the Melker cricothyrotomy kit, and watched a video on cricothyrotomy. Participants were randomized to either the intervention 'Trained' group (n = 10) (taught and practiced cricothyrotomy) or the control 'Non-Trained' group (n = 11) (no extra training). After two to three weeks, performances of the groups were assessed in a simulated CICO scenario. The primary outcome measure was major deviation from the ASA-DAA. Secondary outcome measures were (1) performance of the four categories of non-technical behaviours using the validated Anaesthetists' Non-Technical Skills scale (ANTS) and (2) time to perform specific tasks. Significantly more non-trained than trained participants (6/11 vs 0/10, P = 0.012) committed at least one major ASA-DAA deviation, including failure to insert an oral airway, failure to call for help, bypassing the laryngeal mask airway, and attempting fibreoptic intubation. ANTS scores for all four categories of behaviours, however, were similar between the groups. Trained participants called for help faster [26 (2) vs 63 (48) sec, P = 0.012] but delayed opening of the cricothyrotomy kit [130 (50) vs 74 (36) sec, P = 0.014]. Hands-on training in cricothyrotomy resulted in fewer major ASA-DAA deviations in a simulated CICO scenario. Training in cricothyrotomy may play an important role in complying with the ASA-DAA in a CICO situation but does not appear to affect non-technical behaviours such as decision-making.

Anti-E1E2 antibodies status prior therapy favors direct-acting antiviral treatment efficacy.

PubMed

Virlogeux, Victor; Berthillon, Pascale; Bordes, Isabelle; Larrat, Sylvie; Crouy, Stéphanie; Scholtès, Caroline; Pradat, Pierre; Maynard, Marianne; Zoulim, Fabien; Leroy, Vincent; Chemin, Isabelle; Trépo, Christian; Petit, Marie-Anne

2018-03-15

Presence of anti-E1E2 antibodies was previously associated with spontaneous cure of hepatitis C virus (HCV) and predictive before treatment of a sustained virological response (SVR) to bi- or tri-therapy in naïve or experienced patients, regardless of HCV genotype. We investigated the impact of anti-E1E2 seroprevalence at baseline on treatment response in patients receiving direct-acting antiviral (DAA) therapy. We screened anti-E1E2 antibodies by ELISA in serum samples collected at treatment initiation for two groups of patients: 59 with SVR at the end of DAA treatment and 44 relapsers after DAA treatment. Nineteen patients received a combination of ribavirin (RBV) or PEG-interferon/ribavirin with sofosbuvir or daclatasvir and others received interferon-free treatment with DAA±RBV. HCV viral load was measured at different time points during treatment in a subgroup of patients. A significant association was observed between presence of anti-E1E2 and HCV viral load<6log10 prior treatment. Among patients with anti-E1E2 at baseline, 70% achieved SVR whereas among patients without anti-E1E2, only 45% achieved SVR. Conversely, 66% of patients experiencing DAA-failure were anti-E1E2 negative at baseline. In the multivariate analysis, presence of anti-E1E2 was significantly associated with SVR after adjustment on potential cofounders such as age, sex, fibrosis stage, prior HCV treatment and alanine aminotransferase (ALT) level. The presence of anti-E1E2 at treatment initiation is a predictive factor of SVR among patients treated with DAA and more likely among patients with low initial HCV viral load (<6log10). Absence of anti-E1E2 at baseline could predict DAA-treatment failure. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Decrease of Alpha-fetoprotein in Patients with Cirrhosis Treated with Direct-acting Antivirals.

PubMed

Nguyen, Kelvin; Jimenez, Melissa; Moghadam, Nima; Wu, Crystal; Farid, Alex; Grotts, Jonathan; Elashoff, David; Choi, Gina; Durazo, Francisco A; El-Kabany, Mohamed M; Han, Steven-Huy B; Saab, Sammy

2017-03-28

Background and Aims: The lack of specificity has limited the role of serum alpha-fetoprotein (AFP) for hepatocellular carcinoma (HCC) screening among patients with cirrhosis related to hepatitis C virus (HCV) infection. We sought to examine whether AFP may decrease after achieving a sustained virological response (SVR) in patients with HCV-related cirrhosis. Methods: We performed a retrospective study of patients with HCV-related cirrhosis who were cured with direct-acting antiviral (DAA) therapy at the University of California, Los Angeles. Laboratory values, including serum AFP, were measured before and after completing the DAA treatment. Results: Fifty-six patients met the inclusion criteria, with median (interquartile range [IQR]) age of 67 (58-69) years and with 51.8% being male. All patients received DAA therapy without interferon. AFP decreased from median (IQR) 7.2 (4.2-13.4) ng/mL before DAAs to 4.2 (2.7-6.3) ng/mL at the end of treatment and 4.2 (2.9-6.8) ng/mL at 12 weeks after treatment ( p < 0.001). Model for end-stage liver disease (MELD), fibrosis-4 (FIB4), and aspartate transaminase (AST) to platelet ratio index (APRI) scores at baseline were not significantly associated with AFP reduction. On multivariate analysis, platelet count, AST and total bilirubin at baseline were significantly correlated to AFP reduction ( p = 0.04, 0.009 and 0.04, respectively). The higher the baseline AFP, the greater the reduction in AFP. There was no statistically significant correlation between baseline AFP and MELD, FIB4 or APRI scores. Conclusion: There was a significant decrease in AFP in patients with cirrhosis who achieved a SVR with DAAs. Given a reduction in AFP after DAA treatment, AFP should be further studied as a screening modality for HCC in patients with cirrhosis.

Improvement of ALT decay kinetics by all-oral HCV treatment: Role of NS5A inhibitors and differences with IFN-based regimens

PubMed Central

Cento, Valeria; Nguyen, Thi Huyen Tram; Di Carlo, Domenico; Biliotti, Elisa; Gianserra, Laura; Lenci, Ilaria; Di Paolo, Daniele; Calvaruso, Vincenza; Teti, Elisabetta; Cerrone, Maddalena; Romagnoli, Dante; Melis, Michela; Danieli, Elena; Menzaghi, Barbara; Polilli, Ennio; Siciliano, Massimo; Nicolini, Laura Ambra; Di Biagio, Antonio; Magni, Carlo Federico; Bolis, Matteo; Antonucci, Francesco Paolo; Di Maio, Velia Chiara; Alfieri, Roberta; Sarmati, Loredana; Casalino, Paolo; Bernardini, Sergio; Micheli, Valeria; Rizzardini, Giuliano; Parruti, Giustino; Quirino, Tiziana; Puoti, Massimo; Babudieri, Sergio; D’Arminio Monforte, Antonella; Andreoni, Massimo; Craxì, Antonio; Angelico, Mario; Pasquazzi, Caterina; Taliani, Gloria; Guedj, Jeremie; Ceccherini-Silberstein, Francesca

2017-01-01

Background Intracellular HCV-RNA reduction is a proposed mechanism of action of direct-acting antivirals (DAAs), alternative to hepatocytes elimination by pegylated-interferon plus ribavirin (PR). We modeled ALT and HCV-RNA kinetics in cirrhotic patients treated with currently-used all-DAA combinations to evaluate their mode of action and cytotoxicity compared with telaprevir (TVR)+PR. Study design Mathematical modeling of ALT and HCV-RNA kinetics was performed in 111 HCV-1 cirrhotic patients, 81 treated with all-DAA regimens and 30 with TVR+PR. Kinetic-models and Cox-analysis were used to assess determinants of ALT-decay and normalization. Results HCV-RNA kinetics was biphasic, reflecting a mean effectiveness in blocking viral production >99.8%. The first-phase of viral-decline was faster in patients receiving NS5A-inhibitors compared to TVR+PR or sofosbuvir+simeprevir (p<0.001), reflecting higher efficacy in blocking assembly/secretion. The second-phase, noted δ and attributed to infected-cell loss, was faster in patients receiving TVR+PR or sofosbuvir+simeprevir compared to NS5A-inhibitors (0.27 vs 0.21 d-1, respectively, p = 0.0012). In contrast the rate of ALT-normalization, noted λ, was slower in patients receiving TVR+PR or sofosbuvir+simeprevir compared to NS5A-inhibitors (0.17 vs 0.27 d-1, respectively, p<0.001). There was no significant association between the second-phase of viral-decline and ALT normalization rate and, for a given level of viral reduction, ALT-normalization was more profound in patients receiving DAA, and NS5A in particular, than TVR+PR. Conclusions Our data support a process of HCV-clearance by all-DAA regimens potentiated by NS5A-inhibitor, and less relying upon hepatocyte death than IFN-containing regimens. This may underline a process of “cell-cure” by DAAs, leading to a fast improvement of liver homeostasis. PMID:28545127

Liquid cooled approaches for high density avionics

NASA Astrophysics Data System (ADS)

Levasseur, Robert

Next-generation aircraft will require avionics that provide greater system performance in a smaller volume, a process that requires highly developed thermal management techniques. To meet this need, a liquid-cooled approach has been developed to replace the conventional air-cooled approach for high-power applications. Liquid-cooled chassis and flow-through modules have been developed to limit junction temperatures to acceptable levels. Liquid cooling also permits emergency operation after loss of coolant for longer time intervals, which is desirable for flight-critical airborne applications. Activity to date has emphasized the development of chassis and modules that support the US Department of Defense's (DoD) two-level maintenance initiative as governed by the Joint Integrated Avionics Working Group (JIAWG).

Algorithmic support for graphic images rotation in avionics

NASA Astrophysics Data System (ADS)

Kniga, E. V.; Gurjanov, A. V.; Shukalov, A. V.; Zharinov, I. O.

2018-05-01

The avionics device designing has an actual problem of development and research algorithms to rotate the images which are being shown in the on-board display. The image rotation algorithms are a part of program software of avionics devices, which are parts of the on-board computers of the airplanes and helicopters. Images to be rotated have the flight location map fragments. The image rotation in the display system can be done as a part of software or mechanically. The program option is worse than the mechanic one in its rotation speed. The comparison of some test images of rotation several algorithms is shown which are being realized mechanically with the program environment Altera QuartusII.

The effect of requirements prioritization on avionics system conceptual design

NASA Astrophysics Data System (ADS)

Lorentz, John

This dissertation will provide a detailed approach and analysis of a new collaborative requirements prioritization methodology that has been used successfully on four Coast Guard avionics acquisition and development programs valued at $400M+. A statistical representation of participant study results will be discussed and analyzed in detail. Many technically compliant projects fail to deliver levels of performance and capability that the customer desires. Some of these systems completely meet "threshold" levels of performance; however, the distribution of resources in the process devoted to the development and management of the requirements does not always represent the voice of the customer. This is especially true for technically complex projects such as modern avionics systems. A simplified facilitated process for prioritization of system requirements will be described. The collaborative prioritization process, and resulting artifacts, aids the systems engineer during early conceptual design. All requirements are not the same in terms of customer priority. While there is a tendency to have many thresholds inside of a system design, there is usually a subset of requirements and system performance that is of the utmost importance to the design. These critical capabilities and critical levels of performance typically represent the reason the system is being built. The systems engineer needs processes to identify these critical capabilities, the associated desired levels of performance, and the risks associated with the specific requirements that define the critical capability. The facilitated prioritization exercise is designed to collaboratively draw out these critical capabilities and levels of performance so they can be emphasized in system design. Developing the purpose, scheduling and process for prioritization events are key elements of systems engineering and modern project management. The benefits of early collaborative prioritization flow throughout the project schedule, resulting in greater success during system deployment and operational testing. This dissertation will discuss the data and findings from participant studies, present a literature review of systems engineering and design processes, and test the hypothesis that the prioritization process had no effect on stakeholder sentiment related to the conceptual design. In addition, the "Requirements Rationalization" process will be discussed in detail. Avionics, like many other systems, has transitioned from a discrete electronics engineering, hard engineering discipline to incorporate software engineering as a core process of the technology development cycle. As with other software-based systems, avionics now has significant soft system attributes that must be considered in the design process. The boundless opportunities that exist in software design demand prioritization to focus effort onto the critical functions that the software must provide. This has been a well documented and understood phenomenon in the software development community for many years. This dissertation will attempt to link the effect of software integrated avionics to the benefits of prioritization of requirements in the problem space and demonstrate the sociological and technical benefits of early prioritization practices.

Automated Synthesis of Architecture of Avionic Systems

NASA Technical Reports Server (NTRS)

Chau, Savio; Xu, Joseph; Dang, Van; Lu, James F.

2006-01-01

The Architecture Synthesis Tool (AST) is software that automatically synthesizes software and hardware architectures of avionic systems. The AST is expected to be most helpful during initial formulation of an avionic-system design, when system requirements change frequently and manual modification of architecture is time-consuming and susceptible to error. The AST comprises two parts: (1) an architecture generator, which utilizes a genetic algorithm to create a multitude of architectures; and (2) a functionality evaluator, which analyzes the architectures for viability, rejecting most of the non-viable ones. The functionality evaluator generates and uses a viability tree a hierarchy representing functions and components that perform the functions such that the system as a whole performs system-level functions representing the requirements for the system as specified by a user. Architectures that survive the functionality evaluator are further evaluated by the selection process of the genetic algorithm. Architectures found to be most promising to satisfy the user s requirements and to perform optimally are selected as parents to the next generation of architectures. The foregoing process is iterated as many times as the user desires. The final output is one or a few viable architectures that satisfy the user s requirements.

Integrated Avionics System (IAS), Integrating 3-D Technology On A Spacecraft Panel

NASA Technical Reports Server (NTRS)

Hunter, Don J.; Halpert, Gerald

1999-01-01

As spacecraft designs converge toward miniaturization, and with the volumetric and mass challenges placed on avionics, programs will continue to advance the "state of the art" in spacecraft system development with new challenges to reduce power, mass and volume. Traditionally, the trend is to focus on high-density 3-D packaging technologies. Industry has made significant progress in 3-D technologies, and other related internal and external interconnection schemes. Although new technologies have improved packaging densities, a system packaging architecture is required that not only reduces spacecraft volume and mass budgets, but increase integration efficiencies, provide modularity and flexibility to accommodate multiple missions while maintaining a low recurring cost. With these challenges in mind, a novel system packaging approach incorporates solutions that provide broader environmental applications, more flexible system interconnectivity, scalability, and simplified assembly test and integration schemes. The Integrated Avionics System (IAS) provides for a low-mass, modular distributed or centralized packaging architecture which combines ridged-flex technologies, high-density COTS hardware and a new 3-D mechanical packaging approach, Horizontal Mounted Cube (HMC). This paper will describe the fundamental elements of the IAS, HMC hardware design, system integration and environmental test results.

A Comparison of Bus Architectures for Safety-Critical Embedded Systems

NASA Technical Reports Server (NTRS)

Rushby, John; Miner, Paul S. (Technical Monitor)

2003-01-01

We describe and compare the architectures of four fault-tolerant, safety-critical buses with a view to deducing principles common to all of them, the main differences in their design choices, and the tradeoffs made. Two of the buses come from an avionics heritage, and two from automobiles, though all four strive for similar levels of reliability and assurance. The avionics buses considered are the Honeywell SAFEbus (the backplane data bus used in the Boeing 777 Airplane Information Management System) and the NASA SPIDER (an architecture being developed as a demonstrator for certification under the new DO-254 guidelines); the automobile buses considered are the TTTech Time-Triggered Architecture (TTA), recently adopted by Audi for automobile applications, and by Honeywell for avionics and aircraft control functions, and FlexRay, which is being developed by a consortium of BMW, DaimlerChrysler, Motorola, and Philips.

Spacecraft guidance, navigation, and control requirements for an intelligent plug-n-play avionics (PAPA) architecture

NASA Technical Reports Server (NTRS)

Kulkarni, Nilesh; Krishnakumar, Kalmaje

2005-01-01

The objective of this research is to design an intelligent plug-n-play avionics system that provides a reconfigurable platform for supporting the guidance, navigation and control (GN&C) requirements for different elements of the space exploration mission. The focus of this study is to look at the specific requirements for a spacecraft that needs to go from earth to moon and back. In this regard we will identify the different GN&C problems in various phases of flight that need to be addressed for designing such a plug-n-play avionics system. The Apollo and the Space Shuttle programs provide rich literature in terms of understanding some of the general GN&C requirements for a space vehicle. The relevant literature is reviewed which helps in narrowing down the different GN&C algorithms that need to be supported along with their individual requirements.

Validation of fault-free behavior of a reliable multiprocessor system - FTMP: A case study. [Fault-Tolerant Multi-Processor avionics

NASA Technical Reports Server (NTRS)

Clune, E.; Segall, Z.; Siewiorek, D.

1984-01-01

A program of experiments has been conducted at NASA-Langley to test the fault-free performance of a Fault-Tolerant Multiprocessor (FTMP) avionics system for next-generation aircraft. Baseline measurements of an operating FTMP system were obtained with respect to the following parameters: instruction execution time, frame size, and the variation of clock ticks. The mechanisms of frame stretching were also investigated. The experimental results are summarized in a table. Areas of interest for future tests are identified, with emphasis given to the implementation of a synthetic workload generation mechanism on FTMP.

Customer Avionics Interface Development and Analysis (CAIDA) Lab DEWESoft Display Creation

NASA Technical Reports Server (NTRS)

Coffey, Connor

2015-01-01

The Customer Avionics Interface Development and Analysis (CAIDA) Lab supports the testing of the Launch Control System (LCS), NASA's command and control system for the Space Launch System (SLS), Orion Multi-Purpose Crew Vehicle (MPCV), and ground support equipment. The objectives of the year-long internship were to support day-to-day operations of the CAIDA Lab, create prelaunch and tracking displays for Orion's Exploration Flight Test 1 (EFT-1), and create a program to automate the creation of displays for SLS and MPCV to be used by CAIDA and the Record and Playback Subsystem (RPS).

KSC-2012-2891

NASA Image and Video Library

2011-07-20

LOUISVILLE, Colo. – During NASA's Commercial Crew Development Round 2 CCDev2) activities for the Commercial Crew Program CCP, Sierra Nevada Corp. SNC built a Simulator and Avionics Laboratory to help engineers evaluate the Dream Chaser's characteristics during the piloted phases of flight. Located at Sierra Nevada’s Space Systems facility in Louisville, Colo., it consists of a physical cockpit and integrated simulation hardware and software. The simulator is linked to the Vehicle Avionics Integration Laboratory, or VAIL, which serves as a platform for Dream Chaser avionics development, engineering testing and integration. VAIL also will also be used for verification and validation of avionics and software. Sierra Nevada is one of seven companies NASA entered into Space Act Agreements SAAs with during CCDev2 to aid in the innovation and development of American-led commercial capabilities for crew transportation and rescue services to and from the International Space Station and other low Earth orbit destinations. For information about CCP, visit www.nasa.gov/commercialcrew. Photo credit: Sierra Nevada Corp.

Panoramic projection avionics displays

NASA Astrophysics Data System (ADS)

Kalmanash, Michael H.

2003-09-01

Avionics projection displays are entering production in advanced tactical aircraft. Early adopters of this technology in the avionics community used projection displays to replace or upgrade earlier units incorporating direct-view CRT or AMLCD devices. Typical motivation for these upgrades were the alleviation of performance, cost and display device availability concerns. In these systems, the upgraded (projection) displays were one-for-one form / fit replacements for the earlier units. As projection technology has matured, this situation has begun to evolve. The Lockheed-Martin F-35 is the first program in which the cockpit has been specifically designed to take advantage of one of the more unique capabilities of rear projection display technology, namely the ability to replace multiple small screens with a single large conformal viewing surface in the form of a panoramic display. Other programs are expected to follow, since the panoramic formats enable increased mission effectiveness, reduced cost and greater information transfer to the pilot. Some of the advantages and technical challenges associated with panoramic projection displays for avionics applications are described below.

Network Extender for MIL-STD-1553 Bus

NASA Technical Reports Server (NTRS)

Marcus, Julius; Hanson, T. David

2003-01-01

An extender system for MIL-STD-1553 buses transparently couples bus components at multiple developer sites. The bus network extender is a relatively inexpensive system that minimizes the time and cost of integration of avionic systems by providing a convenient mechanism for early testing without the need to transport the usual test equipment and personnel to an integration facility. This bus network extender can thus alleviate overloading of the test facility while enabling the detection of interface problems that can occur during the integration of avionic systems. With this bus extender in place, developers can correct and adjust their own hardware and software before products leave a development site. Currently resident at Johnson Space Center, the bus network extender is used to test the functionality of equipment that, although remotely located, is connected through a MILSTD- 1553 bus. Inasmuch as the standard bus protocol for avionic equipment is that of MIL-STD-1553, companies that supply MIL-STD-1553-compliant equipment to government or industry and that need long-distance communication support might benefit from this network bus extender

Highly Survivable Avionics Systems for Long-Term Deep Space Exploration

NASA Technical Reports Server (NTRS)

Alkalai, L.; Chau, S.; Tai, A. T.

2001-01-01

The design of highly survivable avionics systems for long-term (> 10 years) exploration of space is an essential technology for all current and future missions in the Outer Planets roadmap. Long-term exposure to extreme environmental conditions such as high radiation and low-temperatures make survivability in space a major challenge. Moreover, current and future missions are increasingly using commercial technology such as deep sub-micron (0.25 microns) fabrication processes with specialized circuit designs, commercial interfaces, processors, memory, and other commercial off the shelf components that were not designed for long-term survivability in space. Therefore, the design of highly reliable, and available systems for the exploration of Europa, Pluto and other destinations in deep-space require a comprehensive and fresh approach to this problem. This paper summarizes work in progress in three different areas: a framework for the design of highly reliable and highly available space avionics systems, distributed reliable computing architecture, and Guarded Software Upgrading (GSU) techniques for software upgrading during long-term missions. Additional information is contained in the original extended abstract.

An autonomous rendezvous and docking system using cruise missile technologies

NASA Technical Reports Server (NTRS)

Jones, Ruel Edwin

1991-01-01

In November 1990 the Autonomous Rendezvous & Docking (AR&D) system was first demonstrated for members of NASA's Strategic Avionics Technology Working Group. This simulation utilized prototype hardware from the Cruise Missile and Advanced Centaur Avionics systems. The object was to show that all the accuracy, reliability and operational requirements established for a space craft to dock with Space Station Freedom could be met by the proposed system. The rapid prototyping capabilities of the Advanced Avionics Systems Development Laboratory were used to evaluate the proposed system in a real time, hardware in the loop simulation of the rendezvous and docking reference mission. The simulation permits manual, supervised automatic and fully autonomous operations to be evaluated. It is also being upgraded to be able to test an Autonomous Approach and Landing (AA&L) system. The AA&L and AR&D systems are very similar. Both use inertial guidance and control systems supplemented by GPS. Both use an Image Processing System (IPS), for target recognition and tracking. The IPS includes a general purpose multiprocessor computer and a selected suite of sensors that will provide the required relative position and orientation data. Graphic displays can also be generated by the computer, providing the astronaut / operator with real-time guidance and navigation data with enhanced video or sensor imagery.

Health management and controls for Earth-to-orbit propulsion systems

NASA Astrophysics Data System (ADS)

Bickford, R. L.

1995-03-01

Avionics and health management technologies increase the safety and reliability while decreasing the overall cost for Earth-to-orbit (ETO) propulsion systems. New ETO propulsion systems will depend on highly reliable fault tolerant flight avionics, advanced sensing systems and artificial intelligence aided software to ensure critical control, safety and maintenance requirements are met in a cost effective manner. Propulsion avionics consist of the engine controller, actuators, sensors, software and ground support elements. In addition to control and safety functions, these elements perform system monitoring for health management. Health management is enhanced by advanced sensing systems and algorithms which provide automated fault detection and enable adaptive control and/or maintenance approaches. Aerojet is developing advanced fault tolerant rocket engine controllers which provide very high levels of reliability. Smart sensors and software systems which significantly enhance fault coverage and enable automated operations are also under development. Smart sensing systems, such as flight capable plume spectrometers, have reached maturity in ground-based applications and are suitable for bridging to flight. Software to detect failed sensors has reached similar maturity. This paper will discuss fault detection and isolation for advanced rocket engine controllers as well as examples of advanced sensing systems and software which significantly improve component failure detection for engine system safety and health management.

Flight Avionics Hardware Roadmap

NASA Technical Reports Server (NTRS)

Hodson, Robert; McCabe, Mary; Paulick, Paul; Ruffner, Tim; Some, Rafi; Chen, Yuan; Vitalpur, Sharada; Hughes, Mark; Ling, Kuok; Redifer, Matt;

Development of STOLAND, a versatile navigation, guidance and control system

NASA Technical Reports Server (NTRS)

Young, L. S.; Hansen, Q. M.; Rouse, W. E.; Osder, S. S.

1972-01-01

STOLAND has been developed to perform navigation, guidance, control, and flight management experiments in advanced V/STOL aircraft. The experiments have broad requirements and have dictated that STOLAND be capable of providing performance that would be realistic and equivalent to a wide range of current and future avionics systems. An integrated digital concept using modern avionics components was selected as the simplest approach to maximizing versatility and growth potential. Unique flexibility has been obtained by use of a single, general-purpose digital computer for all navigation, guidance, control, and displays computation.

Common modular avionics - Partitioning and design philosophy

NASA Astrophysics Data System (ADS)

Scott, D. M.; Mulvaney, S. P.

The design objectives and definition criteria for common modular hardware that will perform digital processing functions in multiple avionic subsystems are examined. In particular, attention is given to weapon system-level objectives, such as increased supportability, reduced life cycle costs, and increased upgradability. These objectives dictate the following overall modular design goals: reduce test equipment requirements; have a large number of subsystem applications; design for architectural growth; and standardize for technology transparent implementations. Finally, specific partitioning criteria are derived on the basis of the weapon system-level objectives and overall design goals.

Aerospace and electronic systems - Advanced concepts and pioneering perspectives; Proceedings of the Sixth Symposium, Dayton, OH, November 14, 15, 1984

NASA Astrophysics Data System (ADS)

Among the topics discussed are: the PRAM approach to technology transfer; all-electric aircraft development; and electronic enhancements for the combat aircraft cockpit. Consideration is also given to application of AI systems to military aircraft; ECM and ECCM technology; and the history of monolithic ICs. Developments in the USAF Avionics Integrity Program (AVIP) are reviewed, with emphasis given to: preventive measures for electrostatic discharges; corrosion prevention to increase avionics integrity; and criteria for stress screening temperature levels.

Orion MPCV Service Module Avionics Ring Pallet Testing, Correlation, and Analysis

NASA Technical Reports Server (NTRS)

Staab, Lucas; Akers, James; Suarez, Vicente; Jones, Trevor

2012-01-01

The NASA Orion Multi-Purpose Crew Vehicle (MPCV) is being designed to replace the Space Shuttle as the main manned spacecraft for the agency. Based on the predicted environments in the Service Module avionics ring, an isolation system was deemed necessary to protect the avionics packages carried by the spacecraft. Impact, sinusoidal, and random vibration testing were conducted on a prototype Orion Service Module avionics pallet in March 2010 at the NASA Glenn Research Center Structural Dynamics Laboratory (SDL). The pallet design utilized wire rope isolators to reduce the vibration levels seen by the avionics packages. The current pallet design utilizes the same wire rope isolators (M6-120-10) that were tested in March 2010. In an effort to save cost and schedule, the Finite Element Models of the prototype pallet tested in March 2010 were correlated. Frequency Response Function (FRF) comparisons, mode shape and frequency were all part of the correlation process. The non-linear behavior and the modeling the wire rope isolators proved to be the most difficult part of the correlation process. The correlated models of the wire rope isolators were taken from the prototype design and integrated into the current design for future frequency response analysis and component environment specification.

A Comprehension Based Analysis of Autoflight System Interfaces

NASA Technical Reports Server (NTRS)

Palmer, Everett (Technical Monitor); Polson, Peter G.

2003-01-01

This cooperative agreement supported Dr. Peter Polson's participation in two interrelated research programs. The first was the development of the Situation-Goal-Behavior (SGB) Model that is both a formal description of an avionics system's logic and behavior and a representation of a system that can be understood by avionics designers, pilots, and training developers. The second was the development of a usability inspection method based on an approximate model, RAFIV, of pilot interactions with the Flight Management System (FMS). The main purpose of this report is to integrate the two models and provide a context in order to better characterize the accomplishments of this research program. A major focus of both the previous and this Cooperative Agreement was the development of usability evaluation methods that can be effectively utilized during all phases of the design, development, and certification process of modern avionics systems. The current efforts to validate these methods have involved showing that they generate useful analyses of known operational and training problems with the current generation of avionics systems in modern commercial airliners. This report is organized into seven sections. Following the overview, the second section describes the Goal-Situation-Behavior model and its applications. The next section summarizes the foundations of the RAFIV model and describes the model in some detail. The contents of both these sections are derived from previous reports referenced in footnotes. The fourth section integrates these two models into a complete design evaluation and training development framework. The fifth section contains conclusions and possible future directions for research. References are in Section 6. Section 7 contains the titles and abstracts of the papers paper describing in more detail the results of this research program.

Man-machine interface requirements - advanced technology

NASA Technical Reports Server (NTRS)

Remington, R. W.; Wiener, E. L.

1984-01-01

Research issues and areas are identified where increased understanding of the human operator and the interaction between the operator and the avionics could lead to improvements in the performance of current and proposed helicopters. Both current and advanced helicopter systems and avionics are considered. Areas critical to man-machine interface requirements include: (1) artificial intelligence; (2) visual displays; (3) voice technology; (4) cockpit integration; and (5) pilot work loads and performance.

Optical interconnection and packaging technologies for advanced avionics systems

NASA Astrophysics Data System (ADS)

Schroeder, J. E.; Christian, N. L.; Cotti, B.

1992-09-01

An optical backplane developed to demonstrate the advantages of high-performance optical interconnections and supporting technologies and designed to be compatible with standard avionics racks is described. The hardware demonstrates the three basic components of optical interconnects: optical sources, an optical signal distribution network, and optical receivers. Results from characterization and environmental tests, including a demonstration of the reliable transmission of serial data at a 1 Gb/s, are reported.

Reference Specifications for SAVOIR Avionics Elements

NASA Astrophysics Data System (ADS)

Hult, Torbjorn; Lindskog, Martin; Roques, Remi; Planche, Luc; Brunjes, Bernhard; Dellandrea, Brice; Terraillon, Jean-Loup

2012-08-01

Space industry and Agencies have been recognizing already for quite some time the need to raise the level of standardisation in the spacecraft avionics systems in order to increase efficiency and reduce development cost and schedule. This also includes the aspect of increasing competition in global space business, which is a challenge that European space companies are facing at all stages of involvement in the international markets.A number of initiatives towards this vision are driven both by the industry and ESA’s R&D programmes. However, today an intensified coordination of these activities is required in order to achieve the necessary synergy and to ensure they converge towards the shared vision. It has been proposed to federate these initiatives under the common Space Avionics Open Interface Architecture (SAVOIR) initiative. Within this initiative, the approach based on reference architectures and building blocks plays a key role.Following the principles outlined above, the overall goal of the SAVOIR is to establish a streamlined onboard architecture in order to standardize the development of avionics systems for space programmes. This reflects the need to increase efficiency and cost-effectiveness in the development process as well as account the trend towards more functionality implemented by the onboard building blocks, i.e. HW and SW components, and more complexity for the overall space mission objectives.

Direct-Acting Antivirals in Chronic Hepatitis C Genotype 4 Infection in Community Care Setting.

PubMed

Gayam, Vijay; Khalid, Mazin; Mandal, Amrendra Kumar; Hussain, Muhammad Rajib; Mukhtar, Osama; Gill, Arshpal; Garlapati, Pavani; Shrestha, Binav; Guss, Debra; Sherigar, Jagannath; Mansour, Mohammed; Mohanty, Smruti

2018-04-01

Limited data exists comparing the safety, tolerability, and efficacy of direct-acting antivirals (DAAs) in patients with chronic hepatitis C genotype 4 (HCV GT-4) in the community practice setting. We aim to evaluate the treatment response of DAAs in these patients. All the HCV GT-4 patients treated with DAAs between January 2014 and October 2017 in a community clinic setting were retrospectively analyzed. Pretreatment baseline patient characteristics, treatment efficacy with sustained virologic response (SVR) at 12 weeks post treatment (SVR12), and adverse reactions were assessed. Fifty-two patients of Middle Eastern (primarily Egyptian) descent were included in the study. Thirty-two patients were treated with ledipasvir/sofosbuvir (Harvoni ® ) ± ribavirin, 12 patients were treated with ombitasvir/paritaprevir/ritonavir/dasabuvir (ViekiraPak ® ) ± ribavirin, and eight patients were treated with sofosbuvir/Velpatasvir (Epclusa ® ). Ten patients (19.2%) had compensated cirrhosis. Overall, SVR at 12 weeks was achieved in 94% in patients who received one of the three DAA regimens (93.8% in Harvoni ® group, 91.7 % in ViekiraPak ® group and 100% in Epclusa ® group). Prior treatment status and type of regimen used in the presence of compensated cirrhosis had no statistical significance on overall SVR achievement (P value = 0.442 and P value = 0.091, respectively). The most common adverse effect was fatigue (27%). In the real-world setting, DAAs are effective and well tolerated in patients with chronic HCV GT-4 infection with a high overall SVR rate of 94%. Large-scale studies are needed to further assess this SVR in these groups.

Mathematical Modeling of Hepatitis C Prevalence Reduction with Antiviral Treatment Scale-Up in Persons Who Inject Drugs in Metropolitan Chicago

DOE PAGES

Echevarria, Desarae; Gutfraind, Alexander; Boodram, Basmattee; ...

2015-08-21

New direct-acting antivirals (DAAs) provide an opportunity to combat hepatitis C virus (HCV) infection in persons who inject drugs (PWID). In our paper, we use a mathematical model to predict the impact of a DAA-treatment scale-up on HCV prevalence among PWID and the estimated cost in metropolitan Chicago.

Mathematical Modeling of Hepatitis C Prevalence Reduction with Antiviral Treatment Scale-Up in Persons Who Inject Drugs in Metropolitan Chicago

DOE Office of Scientific and Technical Information (OSTI.GOV)

Echevarria, Desarae; Gutfraind, Alexander; Boodram, Basmattee

New direct-acting antivirals (DAAs) provide an opportunity to combat hepatitis C virus (HCV) infection in persons who inject drugs (PWID). In our paper, we use a mathematical model to predict the impact of a DAA-treatment scale-up on HCV prevalence among PWID and the estimated cost in metropolitan Chicago.

IgE binding to peanut allergens is inhibited by combined D-aspartic and D-glutamic acids.

PubMed

Chung, Si-Yin; Reed, Shawndrika

2015-01-01

The objective of this study was to determine if D-amino acids (D-aas) bind and inhibit immunoglobulin E (IgE) binding to peanut allergens. D-aas such as D-Asp (aspartic acid), D-Glu (glutamic acid), combined D-[Asp/Glu] and others were each prepared in a cocktail of 9 other D-aas, along with L-amino acids (L-aas) and controls. Each sample was mixed with a pooled plasma from peanut-allergic donors, and tested by ELISA (enzyme-linked immunosorbent assay) and Western blots for IgE binding to peanut allergens. Results showed that D-[Asp/Glu] (4 mg/ml) inhibited IgE binding (75%) while D-Glu, D-Asp and other D-aas had no inhibitory effect. A higher inhibition was seen with D-[Asp/Glu] than with L-[Asp/Glu]. We concluded that IgE was specific for D-[Asp/Glu], not D-Asp or D-Glu, and that D-[Asp/Glu] was more reactive than was L-[Asp/Glu] in IgE inhibition. The finding indicates that D-[Asp/Glu] may have the potential for removing IgE or reducing IgE binding to peanut allergens in vitro. Published by Elsevier Ltd.

Host-Targeting Agents to Prevent and Cure Hepatitis C Virus Infection.

PubMed

Zeisel, Mirjam B; Crouchet, Emilie; Baumert, Thomas F; Schuster, Catherine

2015-11-02

Chronic hepatitis C virus (HCV) infection is a major cause of liver cirrhosis and hepatocellular carcinoma (HCC) which are leading indications of liver transplantation (LT). To date, there is no vaccine to prevent HCV infection and LT is invariably followed by infection of the liver graft. Within the past years, direct-acting antivirals (DAAs) have had a major impact on the management of chronic hepatitis C, which has become a curable disease in the majority of DAA-treated patients. In contrast to DAAs that target viral proteins, host-targeting agents (HTAs) interfere with cellular factors involved in the viral life cycle. By acting through a complementary mechanism of action and by exhibiting a generally higher barrier to resistance, HTAs offer a prospective option to prevent and treat viral resistance. Indeed, given their complementary mechanism of action, HTAs and DAAs can act in a synergistic manner to reduce viral loads. This review summarizes the different classes of HTAs against HCV infection that are in preclinical or clinical development and highlights their potential to prevent HCV infection, e.g., following LT, and to tailor combination treatments to cure chronic HCV infection.

Hepatitis C virus resistance to the new direct-acting antivirals.

PubMed

Esposito, Isabella; Trinks, Julieta; Soriano, Vicente

2016-10-01

The treatment of hepatitis C virus (HCV) infection has dramatically improved in recent years with the widespread use of interferon-free combination regimens. Despite the high sustained virological response (SVR) rates (over 90%) obtained with direct-acting antivirals (DAAs), drug resistance has emerged as a potential challenge. The high replication rate of HCV and the low fidelity of its RNA polymerase result in a high degree of genetic variability in the HCV population, which ultimately explains the rapid selection of drug resistance associated variants (RAVs). Results from clinical trials and real-world experience have both provided important information on the rate and clinical significance of RAVs. They can be present in treatment-naive patients as natural polymorphisms although more frequently they are selected upon treatment failure. In patients engaged in high-risk behaviors, RAVs can be transmitted. Although DAA failures generally occur in less than 10% of treated chronic hepatitis C patients, selection of drug resistance is the rule in most cases. HCV re-treatment options are available, but first-line therapeutic strategies should be optimized to efficiently prevent DAA failure due to baseline HCV resistance. Considerable progress is being made and next-generation DAAs are coming with pangenotypic activity and higher resistance barrier.

2nd & 3rd Generation Vehicle Subsystems

NASA Technical Reports Server (NTRS)

2000-01-01

This paper contains viewgraph presentation on the "2nd & 3rd Generation Vehicle Subsystems" project. The objective behind this project is to design, develop and test advanced avionics, power systems, power control and distribution components and subsystems for insertion into a highly reliable and low-cost system for a Reusable Launch Vehicles (RLV). The project is divided into two sections: 3rd Generation Vehicle Subsystems and 2nd Generation Vehicle Subsystems. The following topics are discussed under the first section, 3rd Generation Vehicle Subsystems: supporting the NASA RLV program; high-performance guidance & control adaptation for future RLVs; Evolvable Hardware (EHW) for 3rd generation avionics description; Scaleable, Fault-tolerant Intelligent Network or X(trans)ducers (SFINIX); advance electric actuation devices and subsystem technology; hybrid power sources and regeneration technology for electric actuators; and intelligent internal thermal control. Topics discussed in the 2nd Generation Vehicle Subsystems program include: design, development and test of a robust, low-maintenance avionics with no active cooling requirements and autonomous rendezvous and docking systems; design and development of a low maintenance, high reliability, intelligent power systems (fuel cells and battery); and design of a low cost, low maintenance high horsepower actuation systems (actuators).

Impact of Thermal Annealing on Organic Photovoltaic Cells Using Regioisomeric Donor-Acceptor-Acceptor Molecules.

PubMed

Zhang, Tao; Han, Han; Zou, Yunlong; Lee, Ying-Chi; Oshima, Hiroya; Wong, Ken-Tsung; Holmes, Russell J

2017-08-02

We report a promising set of donor-acceptor-acceptor (D-A-A) electron-donor materials based on coplanar thieno[3,2-b]/[2,3-b]indole, benzo[c][1,2,5]thiadiazole, and dicyanovinylene, which are found to show broadband absorption with high extinction coefficients. The role of the regioisomeric electron-donating thienoindole moiety on the physical and structural properties is examined. Bulk heterojunction (BHJ) organic photovoltaic cells (OPVs) based on the thieno[2,3-b]indole-based electron donor NTU-2, using C 70 as an electron acceptor, show a champion power conversion efficiency of 5.2% under AM 1.5G solar simulated illumination. This efficiency is limited by a low fill factor (FF), as has previously been the case in D-A-A systems. In order to identify the origin of the limited FF, further insight into donor layer charge-transport behavior is realized by examining planar heterojunction OPVs, with emphasis on the evolution of film morphology with thermal annealing. Compared to as-deposited OPVs that exhibit insufficient donor crystallinity, crystalline OPVs based on annealed thin films show an increase in the short-circuit current density, FF, and power conversion efficiency. These results suggest that that the crystallization of D-A-A molecules might not be realized spontaneously at room temperature and that further processing is needed to realize efficient charge transport in these materials.

Synthesis and characterization of reduced graphite oxide-polymer composites and their application in adsorption of lead.

PubMed

Olanipekun, Opeyemi; Oyefusi, Adebola; Neelgund, Gururaj M; Oki, Aderemi

2015-01-01

Herein, we report the in situ polymerization of 1,5-diaminonaphthalene (15DAN) and 1,4-diaminoanthraquinone (14DAA) on the surface of reduced graphite oxide (RGO). Synthesized RGO-P15DAN and RGO-P14DAA were characterized by FTIR, Raman, SEM, TGA and XRD. The adsorption capacity and adsorptivity of the synthesized composites were investigated by Atomic Absorption Spectroscopy (AAS) using 100 ppm aqueous solution of Pb(2+) ions. Further, we compared the results of the composites with those of poly 1,5-(diaminonaphthalene) (P15DAN), poly 1,4-(diaminoanthraquinone) (P14DAA), RGO, graphite oxide (GO) and graphite. Among the tested adsorbents, RGO-P15DAN demonstrated the high adsorptivity. Copyright © 2015 Elsevier B.V. All rights reserved.

Hepatitis C Virus: Viral Quasispecies and Genotypes.

PubMed

Tsukiyama-Kohara, Kyoko; Kohara, Michinori

2017-12-22

Hepatitis C virus (HCV) mainly replicates in the cytoplasm, where it easily establishes persistent infection, resulting in chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma. Due to its high rate of mutation, HCV forms viral quasispecies, categorized based on the highly variable regions in the envelope protein and nonstructural 5A protein. HCV possesses seven major genotypes, among which genotype 1 is the most prevalent globally. The distribution of HCV genotypes varies based on geography, and each genotype has a different sensitivity to interferon treatment. Recently-developed direct-acting antivirals (DAAs), which target viral proteases or polymerases, mediate drastically better antiviral effects than previous therapeutics. Although treatment with DAAs has led to the development of drug-resistant HCV mutants, the most recently approved DAAs show improved pan-genomic activity, with a higher barrier to viral resistance.

Incidence of DAA failure and the clinical impact of retreatment in real-life patients treated in the advanced stage of liver disease: Interim evaluations from the PITER network

PubMed Central

Gaeta, Giovanni Battista; Brunetto, Maurizia Rossana; Di Leo, Alfredo; Iannone, Andrea; Santantonio, Teresa Antonia; Giammario, Adele; Raimondo, Giovanni; Filomia, Roberto; Coppola, Carmine; Amoruso, Daniela Caterina; Blanc, Pierluigi; Del Pin, Barbara; Chemello, Liliana; Cavalletto, Luisa; Morisco, Filomena; Donnarumma, Laura; Rumi, Maria Grazia; Gasbarrini, Antonio; Siciliano, Massimo; Massari, Marco; Corsini, Romina; Coco, Barbara; Madonia, Salvatore; Cannizzaro, Marco; Zignego, Anna Linda; Monti, Monica; Russo, Francesco Paolo; Zanetto, Alberto; Persico, Marcello; Masarone, Mario; Villa, Erica; Bernabucci, Veronica; Taliani, Gloria; Biliotti, Elisa; Chessa, Luchino; Pasetto, Maria Cristina; Andreone, Pietro; Margotti, Marzia; Brancaccio, Giuseppina; Ieluzzi, Donatella; Borgia, Guglielmo; Zappulo, Emanuela; Calvaruso, Vincenza; Petta, Salvatore; Falzano, Loredana; Quaranta, Maria Giovanna; Weimer, Liliana Elena; Rosato, Stefano; Vella, Stefano; Giannini, Edoardo Giovanni

2017-01-01

Background Few data are available on the virological and clinical outcomes of advanced liver disease patients retreated after first-line DAA failure. Aim To evaluate DAA failure incidence and the retreatment clinical impact in patients treated in the advanced liver disease stage. Methods Data on HCV genotype, liver disease severity, and first and second line DAA regimens were prospectively collected in consecutive patients who reached the 12-week post-treatment and retreatment evaluations from January 2015 to December 2016 in 23 of the PITER network centers. Results Among 3,830 patients with advanced fibrosis (F3) or cirrhosis, 139 (3.6%) failed to achieve SVR. Genotype 3, bilirubin levels >1.5mg/dl, platelet count <120,000/mm3 and the sofosbuvir+ribavirin regimen were independent predictors of failure by logistic regression analysis. The failure rate was 7.6% for patients treated with regimens that are no longer recommended or considered suboptimal (sofosbuvir+ribavirin or simeprevir+sofosbuvir±ribavirin), whereas 1.4% for regimens containing sofosbuvir combined with daclatasvir or ledipasvir or other DAAs. Of the patients who failed to achieve SVR, 72 (51.8%) were retreated with a second DAA regimen, specifically 38 (52.7%) with sofosbuvir+daclatasvir, 27 (37.5%) with sofosbuvir+ledipasvir, and 7 (9.7%) with other DAAs ±ribavirin. Among these, 69 (96%) patients achieved SVR12 and 3 (4%) failed. During a median time of 6 months (range: 5–14 months) between failure and the second DAA therapy, the Child-Pugh class worsened in 12 (16.7%) patients: from A to B in 10 patients (19.6%) and from B to C in 2 patients (10.5%), whereas it did not change in the remaining 60 patients. Following the retreatment SVR12 (median time of 6 months; range: 3–12 months), the Child-Pugh class improved in 17 (23.6%) patients: from B to A in 14 (19.4%) patients, from C to A in 1 patient (1.4%) and from C to B in 2 (2.9%) patients; it remained unchanged in 53 patients (73.6%) and worsened in 2 (2.8%) patients. Of patients who were retreated, 3 (4%) had undergone OLT before retreatment (all reached SVR12 following retreatment) and 2 (2.8%) underwent OLT after having achieved retreatment SVR12. Two (70%) of the 3 patients who failed to achieve SVR12 after retreatment, and 2 (2.8%) of the 69 patients who achieved retreatment SVR12 died from liver failure (Child-Pugh class deteriorated from B to C) or HCC complications. Conclusions Failure rate following the first DAA regimen in patients with advanced disease is similar to or lower than that reported in clinical trials, although the majority of patients were treated with suboptimal regimens. Interim findings showed that worsening of liver function after failure, in terms of Child Pugh class deterioration, was improved by successful retreatment in about one third of retreated patients within a short follow-up period; however, in some advanced liver disease patients, clinical outcomes (Child Pugh class, HCC development, liver failure and death) were independent of viral eradication. PMID:28977040

Incidence of DAA failure and the clinical impact of retreatment in real-life patients treated in the advanced stage of liver disease: Interim evaluations from the PITER network.

PubMed

Kondili, Loreta A; Gaeta, Giovanni Battista; Brunetto, Maurizia Rossana; Di Leo, Alfredo; Iannone, Andrea; Santantonio, Teresa Antonia; Giammario, Adele; Raimondo, Giovanni; Filomia, Roberto; Coppola, Carmine; Amoruso, Daniela Caterina; Blanc, Pierluigi; Del Pin, Barbara; Chemello, Liliana; Cavalletto, Luisa; Morisco, Filomena; Donnarumma, Laura; Rumi, Maria Grazia; Gasbarrini, Antonio; Siciliano, Massimo; Massari, Marco; Corsini, Romina; Coco, Barbara; Madonia, Salvatore; Cannizzaro, Marco; Zignego, Anna Linda; Monti, Monica; Russo, Francesco Paolo; Zanetto, Alberto; Persico, Marcello; Masarone, Mario; Villa, Erica; Bernabucci, Veronica; Taliani, Gloria; Biliotti, Elisa; Chessa, Luchino; Pasetto, Maria Cristina; Andreone, Pietro; Margotti, Marzia; Brancaccio, Giuseppina; Ieluzzi, Donatella; Borgia, Guglielmo; Zappulo, Emanuela; Calvaruso, Vincenza; Petta, Salvatore; Falzano, Loredana; Quaranta, Maria Giovanna; Weimer, Liliana Elena; Rosato, Stefano; Vella, Stefano; Giannini, Edoardo Giovanni

2017-01-01

Few data are available on the virological and clinical outcomes of advanced liver disease patients retreated after first-line DAA failure. To evaluate DAA failure incidence and the retreatment clinical impact in patients treated in the advanced liver disease stage. Data on HCV genotype, liver disease severity, and first and second line DAA regimens were prospectively collected in consecutive patients who reached the 12-week post-treatment and retreatment evaluations from January 2015 to December 2016 in 23 of the PITER network centers. Among 3,830 patients with advanced fibrosis (F3) or cirrhosis, 139 (3.6%) failed to achieve SVR. Genotype 3, bilirubin levels >1.5mg/dl, platelet count <120,000/mm3 and the sofosbuvir+ribavirin regimen were independent predictors of failure by logistic regression analysis. The failure rate was 7.6% for patients treated with regimens that are no longer recommended or considered suboptimal (sofosbuvir+ribavirin or simeprevir+sofosbuvir±ribavirin), whereas 1.4% for regimens containing sofosbuvir combined with daclatasvir or ledipasvir or other DAAs. Of the patients who failed to achieve SVR, 72 (51.8%) were retreated with a second DAA regimen, specifically 38 (52.7%) with sofosbuvir+daclatasvir, 27 (37.5%) with sofosbuvir+ledipasvir, and 7 (9.7%) with other DAAs ±ribavirin. Among these, 69 (96%) patients achieved SVR12 and 3 (4%) failed. During a median time of 6 months (range: 5-14 months) between failure and the second DAA therapy, the Child-Pugh class worsened in 12 (16.7%) patients: from A to B in 10 patients (19.6%) and from B to C in 2 patients (10.5%), whereas it did not change in the remaining 60 patients. Following the retreatment SVR12 (median time of 6 months; range: 3-12 months), the Child-Pugh class improved in 17 (23.6%) patients: from B to A in 14 (19.4%) patients, from C to A in 1 patient (1.4%) and from C to B in 2 (2.9%) patients; it remained unchanged in 53 patients (73.6%) and worsened in 2 (2.8%) patients. Of patients who were retreated, 3 (4%) had undergone OLT before retreatment (all reached SVR12 following retreatment) and 2 (2.8%) underwent OLT after having achieved retreatment SVR12. Two (70%) of the 3 patients who failed to achieve SVR12 after retreatment, and 2 (2.8%) of the 69 patients who achieved retreatment SVR12 died from liver failure (Child-Pugh class deteriorated from B to C) or HCC complications. Failure rate following the first DAA regimen in patients with advanced disease is similar to or lower than that reported in clinical trials, although the majority of patients were treated with suboptimal regimens. Interim findings showed that worsening of liver function after failure, in terms of Child Pugh class deterioration, was improved by successful retreatment in about one third of retreated patients within a short follow-up period; however, in some advanced liver disease patients, clinical outcomes (Child Pugh class, HCC development, liver failure and death) were independent of viral eradication.

Efficacy of Second Generation Direct-Acting Antiviral Agents for Treatment Naïve Hepatitis C Genotype 1: A Systematic Review and Network Meta-Analysis

PubMed Central

Sobhonslidsuk, Abhasnee; Thakkinstian, Ammarin; Teerawattananon, Yot

2015-01-01

Background The treatment of hepatitis C (HCV) infections has significantly changed in the past few years due to the introduction of direct-acting antiviral agents (DAAs). DAAs could improve the sustained virological response compared to pegylated interferon with ribavirin (PR). However, there has been no evidence from randomized controlled trials (RCTs) that directly compare the efficacy among the different regimens of DAAs. Aim Therefore, we performed a systematic review and network meta-analysis aiming to compare the treatment efficacy between different DAA regimens for treatment naïve HCV genotype 1. Methods Medline and Scopus were searched up to 25th May 2015. RCTs investigating the efficacy of second generation DAA regimens for treatment naïve HCV genotype 1 were eligible for the review. Due to the lower efficacy and more side effects of first generation DAAs, this review included only second generation DAAs approved by the US or EU Food and Drug Administration, that comprised of simeprevir (SMV), sofosbuvir (SOF), daclatasvir (DCV), ledipasvir (LDV), and paritaprevir/ritonavir/ombitasvir plus dasabuvir (PrOD). Primary outcomes were sustained virological response at weeks 12 (SVR12) and 24 (SVR24) after the end of treatment and adverse drug events (i.e. serious adverse events, anemia, and fatigue). Efficacy of all treatment regimens were compared by applying a multivariate random effect meta-analysis. Incidence rates of SVR12 and SVR24, and adverse drug events of each treatment regimen were pooled using ‘pmeta’ command in STATA program. Results Overall, 869 studies were reviewed and 16 studies were eligible for this study. Compared with the PR regimen, SOF plus PR, SMV plus PR, and DVC plus PR regimens yielded significantly higher probability of having SVR24 with pooled risk ratios (RR) of 1.98 (95% CI 1.24, 3.14), 1.46 (95% CI: 1.22, 1.75), and 1.68 (95% CI: 1.14, 2.46), respectively. Pooled incidence rates of SVR12 and SVR24 in all treatment regimens without PR, i.e. SOF plus LDV with/without ribavirin, SOF plus SMV with/without ribavirin, SOF plus DCV with/without ribavirin, and PrOD with/without ribavirin, (pooled incidence of SVR12 ranging from 93% to 100%, and pooled incidence of SVR24 ranging from 89% to 96%) were much higher than the pooled incidence rates of SVR12 (51%) and SVR24 (48%) in PR alone. In comparing SOF plus LDV with ribavirin and SOF plus LDV without ribavirin, the chance of having SVR12 was not significantly different between these two regimens, with the pooled RR of 0.99 (95% CI: 0.97, 1.01). Regarding adverse drug events, risk of serious adverse drug events, anemia and fatigue were relatively higher in treatment regimens with PR than the treatment regimens without PR. The main limitation of our study is that a subgroup analysis according to dosages and duration of treatment could not be performed. Therefore, the dose and duration of recommended treatment have been suggested in range and not in definite value. Conclusions Both DAA plus PR and dual DAA regimens should be included in the first line drug for treatment naïve HCV genotype 1 because of the significant clinical benefits over PR alone. However, due to high drug costs, an economic evaluation should be conducted in order to assess the value of the investment when making coverage decisions. PMID:26720298

Newly diagnosed hepatocellular carcinoma in patients with advanced hepatitis C treated with DAAs: A prospective population study.

PubMed

Romano, Antonietta; Angeli, Paolo; Piovesan, Sara; Noventa, Franco; Anastassopoulos, Georgios; Chemello, Liliana; Cavalletto, Luisa; Gambato, Martina; Russo, Francesco Paolo; Burra, Patrizia; Vincenzi, Valter; Scotton, Pier Giorgio; Panese, Sandro; Tempesta, Diego; Bertin, Tosca; Carrara, Maurizio; Carlotto, Antonio; Capra, Franco; Carolo, Giada; Scroccaro, Giovanna; Alberti, Alfredo

2018-03-16

Direct-acting antiviral agents (DAAs) are safe and effective in patients with hepatitis C. Conflicting data were reported on the risk of hepatocellular carcinoma (HCC) during/after therapy with DAAs. The aim of this study was to evaluate the incidence of newly diagnosed HCC and associated risk factors in patients with advanced hepatitis C treated with DAAs. The study is based on the NAVIGATORE platform, a prospectively recording database of all patients with hepatitis C receiving DAAs in the Veneto region of Italy. The inclusion criteria were: fibrosis stage ≥F3. The exclusion criteria were: Child-Turcotte-Pugh (CTP)-C, liver transplantation before DAAs, history or presence of HCC, follow-up <4 weeks after starting DAAs. A total of 3,917 out of 4,234 consecutive patients were included, with a mean follow-up of 536.2 ± 197.6 days. Overall, HCC was diagnosed in 55 patients. During the first year, HCC incidence was 0.46% (95% CI 0.12-1.17) in F3, 1.49% (1.03-2.08) in CTP-A and 3.61% (1.86-6.31) in CTP-B cirrhotics; in the second year, HCC incidences were 0%, 0.2%, and 0.69%, respectively. By multivariate analysis, HCC was significantly associated with an aspartate aminotransferase to platelet ratio ≥2.5 (hazard ratio [HR] 2.03; 95% CI 1.14-3.61; p = 0.016) and hepatitis B virus infection (HR 3.99; 1.24-12.91; p = 0.021). Failure to achieve a sustained virological response was strongly associated with development of HCC (HR 9.09; 5.2-16.1; p = 0.0001). A total of 29% of patients with HCC had an aggressive tumor, often seen in the early phase of treatment. These data, obtained in a large, prospective, population-based study, indicate that in patients with advanced hepatitis C receiving DAAs, the risk of "de novo" hepatocarcinoma during the first year is not higher, and might be lower, than that of untreated patients. The risk further declines thereafter. Early hepatocarcinoma appearance may reflect pre-existing, microscopic, undetectable tumors. Hepatocellular carcinoma is one of the complications of hepatitis C related cirrhosis. Treating patients with advanced hepatitis C with the new interferon-free direct-acting antiviral agents has been associated with improvement in liver function and survival, while more conflicting data have been reported regarding the risk of hepatocellular carcinoma. We report the results of a prospective population study on the incidence of newly diagnosed hepatocellular carcinoma in patients with advanced hepatitis C treated with direct-acting antiviral agents, clearly indicating that the residual hepatocellular carcinoma risk is reduced and declines progressively with time after a sustained virological response. Development of a liver tumor during/after therapy was associated with known risk factors and with virological failure. Copyright © 2018. Published by Elsevier B.V.

Investigation of RF Emissions From Wireless Networks as a Threat to Avionic Systems

NASA Technical Reports Server (NTRS)

Salud, Maria Theresa P.; Williams, Reuben A. (Technical Monitor)

2002-01-01

The paper focuses on understanding and obtaining preliminary measurements of radiated field (RF) emissions of laptop/wireless local area network (WLAN) systems. This work is part of a larger research project to measure radiated emissions of wireless devices to provide a better understanding for potential interference with crucial aircraft avionics systems. A reverberation chamber data collection process is included, as well as recommendations for additional tests. Analysis of measurements from devices under test (DUTs) proved inconclusive for addressing potential interference issues. Continued effort is expected to result in a complete easily reproducible test protocol. The data and protocol presented here are considered preliminary.

Non-functional Avionics Requirements

NASA Astrophysics Data System (ADS)

Paulitsch, Michael; Ruess, Harald; Sorea, Maria

Embedded systems in aerospace become more and more integrated in order to reduce weight, volume/size, and power of hardware for more fuel-effi ciency. Such integration tendencies change architectural approaches of system ar chi tec tures, which subsequently change non-functional requirements for plat forms. This paper provides some insight into state-of-the-practice of non-func tional requirements for developing ultra-critical embedded systems in the aero space industry, including recent changes and trends. In particular, formal requi re ment capture and formal analysis of non-functional requirements of avionic systems - including hard-real time, fault-tolerance, reliability, and per for mance - are exemplified by means of recent developments in SAL and HiLiTE.

Formal Methods in Air Traffic Management: The Case of Unmanned Aircraft Systems

NASA Technical Reports Server (NTRS)

Munoz, Cesar A.

2015-01-01

As the technological and operational capabilities of unmanned aircraft systems (UAS) continue to grow, so too does the need to introduce these systems into civil airspace. Unmanned Aircraft Systems Integration in the National Airspace System is a NASA research project that addresses the integration of civil UAS into non-segregated airspace operations. One of the major challenges of this integration is the lack of an onboard pilot to comply with the legal requirement that pilots see and avoid other aircraft. The need to provide an equivalent to this requirement for UAS has motivated the development of a detect and avoid (DAA) capability to provide the appropriate situational awareness and maneuver guidance in avoiding and remaining well clear of traffic aircraft. Formal methods has played a fundamental role in the development of this capability. This talk reports on the formal methods work conducted under NASA's Safe Autonomous System Operations project in support of the development of DAA for UAS. This work includes specification of low-level and high-level functional requirements, formal verification of algorithms, and rigorous validation of software implementations. The talk also discusses technical challenges in formal methods research in the context of the development and safety analysis of advanced air traffic management concepts.

Aerodynamics of the advanced launch system (ALS) propulsion and avionics (P/A) module

NASA Technical Reports Server (NTRS)

Ferguson, Stan; Savage, Dick

1992-01-01

This paper discusses the design and testing of candidate Advanced Launch System (ALS) Propulsion and Avionics (P/A) Module configurations. The P/A Module is a key element of future launch systems because it is essential to the recovery and reuse of high-value propulsion and avionics hardware. The ALS approach involves landing of first stage (booster) and/or second stage (core) P/A modules near the launch site to minimize logistics and refurbishment cost. The key issue addressed herein is the aerodynamic design of the P/A module, including the stability characteristics and the lift-to-drag (L/D) performance required to achieve the necessary landing guidance accuracy. The reference P/A module configuration was found to be statically stable for the desired flight regime, to provide adequate L/D for targeting, and to have effective modulation of the L/D performance using a body flap. The hypersonic aerodynamic trends for nose corner radius, boattail angle and body flap deflections were consistent with pretest predictions. However, the levels for the L/D and axial force for hypersonic Mach numbers were overpredicted by impact theories.

IXV avionics architecture: Design, qualification and mission results

NASA Astrophysics Data System (ADS)

Succa, Massimo; Boscolo, Ilario; Drocco, Alessandro; Malucchi, Giovanni; Dussy, Stephane

2016-07-01

The paper details the IXV avionics presenting the architecture and the constituting subsystems and equipment. It focuses on the novelties introduced, such as the Ethernet-based protocol for the experiment data acquisition system, and on the synergy with Ariane 5 and Vega equipment, pursued in order to comply with the design-to-cost requirement for the avionics system development. Emphasis is given to the adopted model philosophy in relation to OTS/COTS items heritage and identified activities necessary to extend the qualification level to be compliant with the IXV environment. Associated lessons learned are identified. Then, the paper provides the first results and interpretation from the flight recorders telemetry, covering the behavior of the Data Handling System, the quality of telemetry recording and real-time/delayed transmission, the performance of the batteries and the Power Protection and Distribution Unit, the ground segment coverage during visibility windows and the performance of the GNC sensors (IMU and GPS) and actuators. Finally, some preliminary tracks of the IXV follow on are given, introducing the objectives of the Innovative Space Vehicle and the necessary improvements to be developed in the frame of PRIDE.

The effects of d-aspartic acid supplementation in resistance-trained men over a three month training period: A randomised controlled trial.

PubMed

Melville, Geoffrey W; Siegler, Jason C; Marshall, Paul W M

2017-01-01

Research on d-aspartic acid (DAA) has demonstrated increases in total testosterone levels in untrained men, however research in resistance-trained men demonstrated no changes, and reductions in testosterone levels. The long-term consequences of DAA in a resistance trained population are currently unknown. To evaluate the effectiveness of DAA to alter basal testosterone levels over 3 months of resistance training in resistance-trained men. Randomised, double-blind, placebo controlled trial in healthy resistance-trained men, aged 18-36, had been performing regular resistance training exercise for at least 3 d.w-1 for the previous 2 years. Randomised participants were 22 men (d-aspartic acid n = 11; placebo n = 11) (age, 23.8±4.9 y, training age, 3.2±1.5 y). D-aspartic acid (6 g.d-1, DAA) versus equal-weight, visually-matched placebo (PLA). All participants performed 12 weeks of supervised, periodised resistance training (4 d.w-1), with a program focusing on all muscle groups. Basal hormones, total testosterone (TT), free testosterone (FT), estradiol (E2), sex-hormone-binding globulin (SHBG) and albumin (ALB); isometric strength; calf muscle cross-sectional area (CSA); calf muscle thickness; quadriceps muscle CSA; quadriceps muscle thickness; evoked V-wave and H-reflexes, were assessed at weeks zero (T1), after six weeks (T2) and after 12 weeks (T3). No change in basal TT or FT were observed after the intervention. DAA supplementation (n = 10) led to a 16%, 95% CI [-27%, -5%] reduction in E2 from T1-T3 (p<0.01). The placebo group (n = 9) demonstrated improvements in spinal responsiveness (gastrocnemius) at the level of the alpha motoneuron. Both groups exhibited increases in isometric strength of the plantar flexors by 17%, 95% CI [7%, 28%] (p<0.05) as well as similar increases in hypertrophy in the quadriceps and calf muscles. The results of this paper indicate that DAA supplementation is ineffective at changing testosterone levels, or positively affecting training outcomes. Reductions in estradiol and the blunting of peripheral excitability appear unrelated to improvements from resistance training. Australian New Zealand Clinical Trials Registry ACTRN12617000041358.

HCV Treatment Initiation in Patients with Chronic Kidney Disease: Results from ERCHIVES

PubMed Central

Butt, Adeel; Ren, Yanjie; Puenpatom, Amy; Arduino, Jean Marie; Kumar, Ritesh; Abou-Samra, Abdul-Badi

2017-01-01

Abstract Background Newer directing antiviral agents against HCV (DAAs) are safe and efficacious in persons with chronic kidney disease (CKD). Whether availability of these newer DAAs has resulted in more persons with CKD initiating HCV treatment remains unknown. Methods We identified HCV+ persons in ERCHIVES. We excluded HIV+ and HBsAg+ and those with missing HCV RNA and eGFR data. We determined the CKD stage according to National Kidney Foundation criteria. We determined the number of persons initiated on any of the approved DAA-regimen (defined as >14 days of DAA prescription). Logistic regression analyses was used to determine factors associated with treatment initiation. Results Among 76,513 evaluable persons, 21.1% initiated DAA treatment. Initiation rates differed significantly by CKD stage: 21.1% (15,136/68,469) for eGFR>90mL/minute/1.73m2 and CKD stage-2; 14.0% 9853/6,086) for CKD stage 3; and 7.6% (148/1,958) for CKD stage-4/5. Those with CKD stage-3 were 35% less likely and those with CKD stage-4/5 were 65% less likely to initiate treatment with a DAA compared with those with baseline eGFR>90mL/minute/1.73m2. Those with Body Mass Index (BMI)>30 were more likely to initiate treatment (OR 1.24, 95% CI 1.19,1.29). Treatment initiation was less likely in HCV genotype 2 or 3 and those with diabetes (OR 0.82, 95% CI 0.78,0.86), cardiovascular disease (OR 0.73, 95% CI 0.68,0.78), alcohol abuse or dependence (OR 0.75, 95% CI 0.72,0.78) or cirrhosis (OR 0.85, 95% CI 0.80,0.89) at baseline. Conclusion Persons with more advanced CKD are less likely to receive treatment for HCV. Strategies are needed to improve treatment rates in the HCV/CKD population. Disclosures A. Butt, Merck: Investigator, Grant recipient. A. Puenpatom, Merck: Employee, Salary. J. M. Arduino, Merck: Employee, Salary. R. Kumar, Merck: Employee, Salary

Impact of hepatitis C virus polymorphisms on direct-acting antiviral treatment efficacy: Regulatory analyses and perspectives.

PubMed

Harrington, Patrick R; Komatsu, Takashi E; Deming, Damon J; Donaldson, Eric F; O'Rear, Julian J; Naeger, Lisa K

2018-06-01

Several highly effective, interferon-free, direct-acting antiviral (DAA)-based regimens are available for the treatment of chronic hepatitis C virus (HCV) infection. Despite impressive efficacy overall, a small proportion of patients in registrational trials experienced treatment failure, which in some cases was associated with the detection of HCV resistance-associated substitutions (RASs) at baseline. In this article, we describe methods and key findings from independent regulatory analyses investigating the impact of baseline nonstructural (NS) 3 Q80K and NS5A RASs on the efficacy of current United States Food and Drug Administration (FDA)-approved regimens for patients with HCV genotype (GT) 1 or GT3 infection. These analyses focused on clinical trials that included patients who were previously naïve to the DAA class(es) in their investigational regimen and characterized the impact of baseline RASs that were enriched in the viral population as natural or transmitted polymorphisms (i.e., not drug-selected RASs). We used a consistent approach to optimize comparability of results across different DAA regimens and patient populations, including the use of a 15% sensitivity cutoff for next-generation sequencing results and standardized lists of NS5A RASs. These analyses confirmed that detection of NS3 Q80K or NS5A baseline RASs was associated with reduced treatment efficacy for multiple DAA regimens, but their impact was often minimized with the use of an intensified treatment regimen, such as a longer treatment duration and/or addition of ribavirin. We discuss the drug resistance-related considerations that contributed to pretreatment resistance testing and treatment recommendations in drug labeling for FDA-approved DAA regimens. Independent regulatory analyses confirmed that baseline HCV RASs can reduce the efficacy of certain DAA-based regimens in selected patient groups. However, highly effective treatment options are available for patients with or without baseline RASs. (Hepatology 2018;67:2430-2448). Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

Advanced Avionics and Processor Systems for a Flexible Space Exploration Architecture

NASA Technical Reports Server (NTRS)

Keys, Andrew S.; Adams, James H.; Smith, Leigh M.; Johnson, Michael A.; Cressler, John D.

2010-01-01

The Advanced Avionics and Processor Systems (AAPS) project, formerly known as the Radiation Hardened Electronics for Space Environments (RHESE) project, endeavors to develop advanced avionic and processor technologies anticipated to be used by NASA s currently evolving space exploration architectures. The AAPS project is a part of the Exploration Technology Development Program, which funds an entire suite of technologies that are aimed at enabling NASA s ability to explore beyond low earth orbit. NASA s Marshall Space Flight Center (MSFC) manages the AAPS project. AAPS uses a broad-scoped approach to developing avionic and processor systems. Investment areas include advanced electronic designs and technologies capable of providing environmental hardness, reconfigurable computing techniques, software tools for radiation effects assessment, and radiation environment modeling tools. Near-term emphasis within the multiple AAPS tasks focuses on developing prototype components using semiconductor processes and materials (such as Silicon-Germanium (SiGe)) to enhance a device s tolerance to radiation events and low temperature environments. As the SiGe technology will culminate in a delivered prototype this fiscal year, the project emphasis shifts its focus to developing low-power, high efficiency total processor hardening techniques. In addition to processor development, the project endeavors to demonstrate techniques applicable to reconfigurable computing and partially reconfigurable Field Programmable Gate Arrays (FPGAs). This capability enables avionic architectures the ability to develop FPGA-based, radiation tolerant processor boards that can serve in multiple physical locations throughout the spacecraft and perform multiple functions during the course of the mission. The individual tasks that comprise AAPS are diverse, yet united in the common endeavor to develop electronics capable of operating within the harsh environment of space. Specifically, the AAPS tasks for the Federal fiscal year of 2010 are: Silicon-Germanium (SiGe) Integrated Electronics for Extreme Environments, Modeling of Radiation Effects on Electronics, Radiation Hardened High Performance Processors (HPP), and and Reconfigurable Computing.

How to Extend the Capabilities of Space Systems for Long Duration Space Exploration Systems

NASA Technical Reports Server (NTRS)

Marzwell, Neville I.; Waterman, Robert D.; KrishnaKumar, Kalmanje; Waterman, Susan J.

2005-01-01

For sustainable Exploration Missions the need exists to assemble systems-of-systems in space, on the Moon or on other planetary surfaces. To fulfill this need new and innovative system architecture is needed that can be satisfied with the present lift capability of existing rocket technology without the added cost of developing a new heavy lift vehicle. To enable ultra-long life missions with minimum redundancy and lighter mass the need exists to develop system soft,i,are and hardware reconfigurability, which enables increasing functionality and multiple use of launched assets while at the same time overcoming any components failures. Also the need exists to develop the ability to dynamically demate and reassemble individual system elements during a mission in order to work around failed hardware or changed mission requirements. Therefore to meet the goals of Space Exploration Missions in hiteroperability and Reconfigurability, many challenges must be addressed to transform the traditional static avionics architecture into architecture with dynamic capabilities. The objective of this paper is to introduce concepts associated with reconfigurable computer systems; review the various needs and challenges associated with reconfigurable avionics space systems; provide an operational example that illustrates the needs applicable to either the Crew Exploration Vehicle or a collection of "Habot like" mobile surface elements; summarize the approaches that address key challenges to acceptance of a Flexible, Intelligent, Modular and Affordable reconfigurable avionics space system.

ARINC 818 specification revisions enable new avionics architectures

NASA Astrophysics Data System (ADS)

Grunwald, Paul

2014-06-01

The ARINC 818 Avionics Digital Video Bus is the standard for cockpit video that has gained wide acceptance in both the commercial and military cockpits. The Boeing 787, A350XWB, A400M, KC-46A, and many other aircraft use it. The ARINC 818 specification, which was initially release in 2006, has recently undergone a major update to address new avionics architectures and capabilities. Over the seven years since its release, projects have gone beyond the specification due to the complexity of new architectures and desired capabilities, such as video switching, bi-directional communication, data-only paths, and camera and sensor control provisions. The ARINC 818 specification was revised in 2013, and ARINC 818-2 was approved in November 2013. The revisions to the ARINC 818-2 specification enable switching, stereo and 3-D provisions, color sequential implementations, regions of interest, bi-directional communication, higher link rates, data-only transmission, and synchronization signals. This paper discusses each of the new capabilities and the impact on avionics and display architectures, especially when integrating large area displays, stereoscopic displays, multiple displays, and systems that include a large number of sensors.

Sunlight readable avionics displays

NASA Astrophysics Data System (ADS)

Visinski, Joseph R.

1998-09-01

The theme of the Cockpit Displays V Conference of 'Custom versus Consumer -- Grade Displays in Defense Applications' reflects the Raytheon Systems Company field emission display (FED) development effort. Raytheon chose to license commercial FED technology and subsequently participate in a commercial industry 'FED Alliance' to insert this technology into commercial and avionics defense applications. The unaffordability of custom military displays makes them an unfeasible choice to build a business upon. The major differences between consumer FEDs and those adapted for military/avionics installations are: (1) high brightness for sunlight visibility; (2) extended environmental range; (3) high resolution; (4) wider dimming range for sunlight to NVIS operation; (5) extended gray scales; (6) lifetime product support well beyond two year consumer market life. The transition to defense applications is further being accomplished via industry/government partnerships as the DARPA Technology Reinvestment Project (TRP) and BAA 97-31. FEDs combine cathode ray tube (CRT) and matrix addressed flat panel display technology, parts, manufacturing, and test equipment, plus open systems interfaces into a new display.

A Formal Model of Partitioning for Integrated Modular Avionics

NASA Technical Reports Server (NTRS)

DiVito, Ben L.

1998-01-01

The aviation industry is gradually moving toward the use of integrated modular avionics (IMA) for civilian transport aircraft. An important concern for IMA is ensuring that applications are safely partitioned so they cannot interfere with one another. We have investigated the problem of ensuring safe partitioning and logical non-interference among separate applications running on a shared Avionics Computer Resource (ACR). This research was performed in the context of ongoing standardization efforts, in particular, the work of RTCA committee SC-182, and the recently completed ARINC 653 application executive (APEX) interface standard. We have developed a formal model of partitioning suitable for evaluating the design of an ACR. The model draws from the mathematical modeling techniques developed by the computer security community. This report presents a formulation of partitioning requirements expressed first using conventional mathematical notation, then formalized using the language of SRI'S Prototype Verification System (PVS). The approach is demonstrated on three candidate designs, each an abstraction of features found in real systems.

On TTEthernet for Integrated Fault-Tolerant Spacecraft Networks

NASA Technical Reports Server (NTRS)

Loveless, Andrew

2015-01-01

There has recently been a push for adopting integrated modular avionics (IMA) principles in designing spacecraft architectures. This consolidation of multiple vehicle functions to shared computing platforms can significantly reduce spacecraft cost, weight, and de- sign complexity. Ethernet technology is attractive for inclusion in more integrated avionic systems due to its high speed, flexibility, and the availability of inexpensive commercial off-the-shelf (COTS) components. Furthermore, Ethernet can be augmented with a variety of quality of service (QoS) enhancements that enable its use for transmitting critical data. TTEthernet introduces a decentralized clock synchronization paradigm enabling the use of time-triggered Ethernet messaging appropriate for hard real-time applications. TTEthernet can also provide two forms of event-driven communication, therefore accommodating the full spectrum of traffic criticality levels required in IMA architectures. This paper explores the application of TTEthernet technology to future IMA spacecraft architectures as part of the Avionics and Software (A&S) project chartered by NASA's Advanced Exploration Systems (AES) program.

Light weight, high-speed, and self-powered wireless fiber optic sensor (WiFOS) structural health monitor system for avionics and aerospace environments

NASA Astrophysics Data System (ADS)

Mendoza, Edgar A.; Kempen, Cornelia; Sun, Sunjian; Esterkin, Yan

2014-09-01

This paper describes recent progress towards the development of an innovative light weight, high-speed, and selfpowered wireless fiber optic sensor (WiFOS™) structural health monitor system suitable for the onboard and in-flight unattended detection, localization, and classification of load, fatigue, and structural damage in advanced composite materials commonly used in avionics and aerospace systems. The WiFOS™ system is based on ROI's advancements on monolithic photonic integrated circuit microchip technology, integrated with smart power management, on-board data processing, wireless data transmission optoelectronics, and self-power using energy harvesting tools such as solar, vibration, thermoelectric, and magneto-electric. The self-powered, wireless WiFOS™ system offers a versatile and powerful SHM tool to enhance the reliability and safety of avionics platforms, jet fighters, helicopters, commercial aircraft that use lightweight composite material structures, by providing comprehensive information about the structural integrity of the structure from a large number of locations. Immediate SHM applications are found in rotorcraft and aircraft, ships, submarines, and in next generation weapon systems, and in commercial oil and petrochemical, aerospace industries, civil structures, power utilities, portable medical devices, and biotechnology, homeland security and a wide spectrum of other applications.

Virological patterns of HCV patients with failure to interferon-free regimens.

PubMed

Starace, Mario; Minichini, Carmine; De Pascalis, Stefania; Macera, Margherita; Occhiello, Laura; Messina, Vincenzo; Sangiovanni, Vincenzo; Adinolfi, Luigi E; Claar, Ernesto; Precone, Davide; Stornaiuolo, Gianfranca; Stanzione, Maria; Ascione, Tiziana; Caroprese, Mara; Zampino, Rosa; Parrilli, Gianpaolo; Gentile, Ivan; Brancaccio, Giuseppina; Iovinella, Vincenzo; Martini, Salvatore; Masarone, Mario; Fontanella, Luca; Masiello, Addolorata; Sagnelli, Evangelista; Punzi, Rodolfo; Salomone Megna, Angelo; Santoro, Renato; Gaeta, Giovanni B; Coppola, Nicola

2018-05-01

The study characterized the virological patterns and the resistance-associated substitutions (RASs) in patients with failure to IFN-free regimens enrolled in the real-life setting. All 87 consecutive HCV patients with failed IFN-free regimens, observed at the laboratory of the University of Campania, were enrolled. All patients had been treated with DAA regimens according to the HCV genotype, international guidelines, and local availability. Sanger sequencing of NS3, NS5A, and NS5B regions was performed at failure by home-made protocols. Of the 87 patients enrolled, 13 (14.9%) showed a misclassified HCV genotype, probably causing DAA failure, 16 had been treated with a sub-optimal DAA regimen, 19 with a simeprevir-based regimen and 39 with an optimal DAA regimen. A major RAS was identified more frequently in the simeprevir regimen group (68.4%) and in the optimal regimen group (74.4%) than in the sub-optimal regimen group (56.3%). The prevalence of RASs in NS3 was similar in the three groups (30.8-57.9%), that in NS5A higher in the optimal regimen group (71.8%) than in the sub-optimal regimen group (12.5%, P < 0.0001) and in the simeprevir regimen group (31.6%, P < 0.0005), and that in NS5B low in all groups (0-25%). RASs in two or more HCV regions were more frequently identified in the optimal regimen group (46.6%) than in the simeprevir-based regimen group (31.6%) and sub-optimal regimen group (18.7%). In our real-life population the prevalence of RASs was high, especially in NS3 and NS5A and in those treated with suitable DAA regimens. © 2018 Wiley Periodicals, Inc.

Muscle Damage After Total Hip Arthroplasty Through the Direct Anterior Approach for Developmental Dysplasia of the Hip.

PubMed

Kawasaki, Masashi; Hasegawa, Yukiharu; Okura, Toshiaki; Ochiai, Satoshi; Fujibayashi, Takayoshi

2017-08-01

Total hip arthroplasty (THA) through the direct anterior approach (DAA) is known to cause less muscle damage than other surgical approaches. However, more complex primary cases, such as developmental dysplasia of the hip (DDH), might often cause muscle damage. The objective of the present study was to clarify the muscle damage observed 1 year after THA through the DAA for DDH using magnetic resonance imaging. We prospectively compared the muscle cross-sectional area (M-CSA) and fatty atrophy (FA) in muscles by magnetic resonance imaging and the Harris hip score before and at 1-year follow-up after THA through the DAA in 3 groups: 37 patients with Crowe group 1 DDH (D1), 13 patients with Crowe group 2 and 3 DDH (D2 + 3), and 12 patients with osteonecrosis as a control. THA through the DAA for D1 displayed significantly decreased M-CSA and significantly increased FA in the gluteus minimus (Gmini), the tensor fasciae latae (TFL), and the obturator internus (OI). Patients with D2 + 3 group did not have decreased M-CSA in the TFL or increased FA in the Gmini. Postoperatively, a significant negative correlation was observed between the M-CSA and FA for the OI in patients with D1 and D2 + 3. THA through the DAA for DDH caused the damage in the Gmini, the TFL, and the OI; severe damage was observed in the OI, showing increased FA with decreased M-CSA in patients with both D1 and D2 + 3. Copyright © 2017 Elsevier Inc. All rights reserved.

Laboratory evaluation of the Design Analysis Associates DAA H-3613i radar water-level sensor—Results of temperature, distance, and SDI-12 tests

USGS Publications Warehouse

Carnley, Mark V.

2016-09-30

The Design Analysis Associates (DAA) DAA H-3613i radar water-level sensor (DAA H-3613i), manufactured by Xylem Incorporated, was evaluated by the U.S. Geological Survey (USGS) Hydrologic Instrumentation Facility (HIF) for conformance to manufacturer’s accuracy specifications for measuring a distance throughout the sensor’s operating temperature range, for measuring distances from 3 to 15 feet at ambient temperatures, and for compliance with the SDI-12 serial-to-digital interface at 1200-baud communication standard. The DAA H-3613i is a noncontact water-level sensor that uses pulsed radar to measure the distance between the radar and the water surface from 0.75 to 131 feet over a temperature range of −40 to 60 degrees Celsius (°C). Manufacturer accuracy specifications that were evaluated, the test procedures that followed, and the results obtained are described in this report. The sensor’s accuracy specification of ± 0.01 feet (± 3 millimeters) meets USGS requirements for a primary water-stage sensor used in the operation of a streamgage. The sensor met the manufacturer’s stated accuracy specifications for water-level measurements during temperature testing at a distance of 8 feet from the target over its temperature-compensated operating range of −40 to 60 °C, except at 60 °C. At 60 °C, about half the measurements exceeded the manufacturer’s accuracy specification by not more than 0.005 feet.The sensor met the manufacturer’s stated accuracy specifications for water-level measurements during distance-accuracy testing at the tested distances from 3 to 15 feet above the water surface at the HIF.

Treatment of Chronic HCV Infection with the New Direct Acting Antivirals (DAA): First Report of a Real World Experience in Southern Brazil.

PubMed

Cheinquer, Hugo; Sette, Hoel; Wolff, Fernando H; de Araujo, Alexandre; Coelho-Borges, Silvia; Soares, Silvia R P; Barros, Mauricio F A

2017-01-01

There is almost no data regarding the efficacy of direct acting antivirals (DAAs) therapy in Brazil. The aim of this historical cohort study is to describe the sustained virologic response (SVR) rate among real-world compensated chronic hepatitis C patients in three hepatology centers from Southern Brazil. Patients were included if they had at least 12 weeks follow-up after the end of therapy. Patients that were lost to follow-up or had treatment prematurely interrupted for any reason were considered treatment failure in this intention to treat analysis. 219 patients were analyzed. Mean age was 57.4 ± 10.9 years and 142/219 (64.8%) were male. Genotype 1 was present in 166 patients (75.8%; 1a 29.2%, 1b 46.6%); Genotypes 2, 3 and 4 in 8 (3.7%), 43 (19.6%) and 2 (0.9%), respectively. 96 (43.8%) were cirrhotic. 134 (59.5%) were treatment experienced. DAA therapies were: sofosbuvir (SOF) + ribavirin (RBV) in 10 patients; SOF + simeprevir (SMV) ± RBV in 73; SOF + pegylated interferon (PEG-IFN) + RBV in 6; SOF + daclatasvir (DCV) ± RBV in 51, SOF + ledipasvir (LDV) ± RBV in 61, and paritaprevir/ ritonavir + ombitasvir + dasabuvir (PTVr/OBV/DSV) ± RBV in 18 patients. SVR-12 was achieved in 208/219 (95%). Ten patients had virologic failure: 6 cirrhotic, 7 treatment experienced, and 6 either genotype 3 or 1a. No adverse event was attributed to the DAA therapy. Real world experience with DAA therapy in Southern Brazil showed a high rate of SVR and excellent tolerability. Failure to achieve SVR was mainly observed among patients with at least one negative predictor of response: cirrhosis and/or genotypes 1a or 3.

Low incidence of hepatitis B virus reactivation and subsequent hepatitis in patients with chronic hepatitis C receiving direct-acting antiviral therapy.

PubMed

Tamori, A; Abiru, S; Enomoto, H; Kioka, K; Korenaga, M; Tani, J; Enomoto, M; Sugiyama, M; Masaki, T; Kawada, N; Yatsuhashi, H; Nishiguchi, S; Mizokami, M

2018-05-01

To determine the clinical characteristics of hepatitis B virus (HBV) reactivation in patients undergoing interferon-free antihepatitis C virus (HCV) therapy, we examined HBV DNA in 25 HBV co-infected patients and 765 patients with resolved HBV infection during and after treatment with direct-acting antiviral agents (DAAs). Among those with HCV genotype 1, asunaprevir plus daclatasvir was administered to 160 patients, sofosbuvir (SOF) plus ledipasvir to 438 patients and paritaprevir plus ombitasvir and ritonavir to 25 patients. In total, 167 patients with genotype 2 were treated with SOF plus ribavirin. Three patients with an HBV DNA level ≥2000 IU/mL were treated with entecavir before anti-HCV therapy, without reactivation of HBV. In 3 of 22 (12%) HBV surface antigen (HBsAg)-positive patients with an HBV DNA level <2000 IU/mL, the viral load increased during treatment. However, hepatitis flare did not occur in these patients. There was no significant difference in clinical history between patients with and without HBV reactivation. Among 765 patients with resolved HBV infection, HBV reactivation occurred in 1 (0.1%) patient after initial resolution, whose HBV DNA level spontaneously decreased after DAA therapy. We compared anti-HBs titres at baseline with those at post-DAA therapy in 123 patients without HBsAg. There was no significant difference in anti-HBs levels between the two points (P = .79). In conclusion, HBV reactivation was rare in HBsAg-negative patients treated with DAA therapy. Additionally, hepatitis did not occur in HBV-reactivated patients with a baseline HBV DNA level <2000 IU/mL before DAA therapy. © 2017 John Wiley & Sons Ltd.

Vascular Function in Grape Berries across Development and Its Relevance to Apparent Hydraulic Isolation1[C

PubMed Central

Choat, Brendan; Gambetta, Greg A.; Shackel, Kenneth A.; Matthews, Mark A.

2009-01-01

During the latter stages of development in fleshy fruit, water flow through the xylem declines markedly and the requirements of transpiration and further expansion are fulfilled primarily by the phloem. We evaluated the hypothesis that cessation of water transport through the xylem results from disruption or occlusion of pedicel and berry xylem conduits (hydraulic isolation). Xylem hydraulic resistance (Rh) was measured in developing fruit of grape (Vitis vinifera ‘Chardonnay’) 20 to 100 d after anthesis (DAA) and compared with observations of xylem anatomy by light and cryo-scanning electron microscopy and expression of six plasma membrane intrinsic protein (PIP) aquaporin genes (VvPIP1;1, VvPIP1;2, VvPIP1;3, VvPIP2;1, VvPIP2;2, VvPIP2;3). There was a significant increase in whole berry Rh and receptacle Rh in the latter stages of ripening (80–100 DAA), which was associated with deposition of gels or solutes in many receptacle xylem conduits. Peaks in the expression of some aquaporin isoforms corresponded to lower whole berry Rh 60 to 80 DAA, and the increase in Rh beginning at 80 DAA correlated with decreases in the expression of the two most predominantly expressed PIP genes. Although significant, the increase in berry Rh was not great enough, and occurred too late in development, to explain the decline in xylem flow that occurs at 60 to 75 DAA. The evidence suggests that the fruit is not hydraulically isolated from the parent plant by xylem occlusion but, rather, is “hydraulically buffered” by water delivered via the phloem. PMID:19741048

Direct-Acting Antivirals in Chronic Hepatitis C Genotype 4 Infection in Community Care Setting

PubMed Central

Gayam, Vijay; Khalid, Mazin; Mandal, Amrendra Kumar; Hussain, Muhammad Rajib; Mukhtar, Osama; Gill, Arshpal; Garlapati, Pavani; Shrestha, Binav; Guss, Debra; Sherigar, Jagannath; Mansour, Mohammed; Mohanty, Smruti

2018-01-01

Background Limited data exists comparing the safety, tolerability, and efficacy of direct-acting antivirals (DAAs) in patients with chronic hepatitis C genotype 4 (HCV GT-4) in the community practice setting. We aim to evaluate the treatment response of DAAs in these patients. Methods All the HCV GT-4 patients treated with DAAs between January 2014 and October 2017 in a community clinic setting were retrospectively analyzed. Pretreatment baseline patient characteristics, treatment efficacy with sustained virologic response (SVR) at 12 weeks post treatment (SVR12), and adverse reactions were assessed. Results Fifty-two patients of Middle Eastern (primarily Egyptian) descent were included in the study. Thirty-two patients were treated with ledipasvir/sofosbuvir (Harvoni®) ± ribavirin, 12 patients were treated with ombitasvir/paritaprevir/ritonavir/dasabuvir (ViekiraPak®) ± ribavirin, and eight patients were treated with sofosbuvir/Velpatasvir (Epclusa®). Ten patients (19.2%) had compensated cirrhosis. Overall, SVR at 12 weeks was achieved in 94% in patients who received one of the three DAA regimens (93.8% in Harvoni® group, 91.7 % in ViekiraPak® group and 100% in Epclusa® group). Prior treatment status and type of regimen used in the presence of compensated cirrhosis had no statistical significance on overall SVR achievement (P value = 0.442 and P value = 0.091, respectively). The most common adverse effect was fatigue (27%). Conclusions In the real-world setting, DAAs are effective and well tolerated in patients with chronic HCV GT-4 infection with a high overall SVR rate of 94%. Large-scale studies are needed to further assess this SVR in these groups. PMID:29707080

Rate and predictors of treatment failure to all-oral HCV regimens outside clinical trials.

PubMed

Arias, Ana; Aguilera, Antonio; Soriano, Vicente; Benítez-Gutiérrez, Laura; Lledó, Gemma; Navarro, Daniel; Treviño, Ana; Otero, Esteban; Peña, José M; Cuervas-Mons, Valentín; de Mendoza, Carmen

2017-01-01

Cure rates above 90% have been reported in most Phase III clinical trials using distinct all-oral direct-acting antivirals (DAAs) in chronic hepatitis C patients. Preliminary results in real-world patients have confirmed this, although efficacy tends to be lower. All consecutive chronic hepatitis C patients treated with all-oral DAA regimens at three hepatitis clinics in Spain were retrospectively examined. Host and viral factors were tested as predictors of treatment failure. A total of 363 chronic hepatitis C patients had completed a course of all-oral DAA therapy outside clinical trials up to the end of 2015. All but 14 (4%) patients achieved sustained virological response. There were 10 failures that occurred after 12 weeks of sofosbuvir-ledipasvir, despite 5 of them being on ribavirin. All failures but one were relapses. The only patient with viral breakthrough selected NS5B L159F and NS5A Y93H. In multivariate analyses, only advanced liver fibrosis (Metavir F3-F4) and HIV coinfection were significantly associated with treatment failure. A trend towards lower response was seen for HCV genotype 4. Treatment failures outside clinical trials are roughly seen in 4% of chronic hepatitis C patients who complete a course of all-oral DAA therapy, resembling what is seen in registration trials. In our series, outcomes were not significantly influenced by ribavirin addition, IL28B polymorphisms, HCV genotype, high baseline HCV RNA or prior interferon failure. However, advanced liver fibrosis and HIV coinfection were significantly associated with treatment failure. Our findings support that there is still room for individualization of current DAA therapy.

Cross channel dependency requirements of the multi-path redundant avionics suite

NASA Astrophysics Data System (ADS)

Martin, Fred; Adams, Darryl

Requirements for cross channel dependencies in the multipath redundant avionics suite (MPRAS) architecture are described. MPRAS is a data synchronous avionics architecture for space launch vehicle applications. The MPRAS cross channel data link (CCDL) provides the mechanism, required by data synchronous architectures, to exchange data and maintain synchronization among redundant channels. MPRAS architectural requirements impose a variety of characteristics for cross channel dependencies which make traditional CCDL solutions unacceptable for MPRAS target applications. The MPRAS CCDL requirements have led to a CCDL design which maintains resilience to faults, does not introduce large cross channel bandwidth reductions, and meets the other established MPRAS CCDL requirements. A review of fault-tolerant system principles applicable to CCDL issues is presented as well as a top-level functional description of the MPRAS CCDL design.

Advanced Aircraft Interfaces: The Machine Side of the Man-Machine Interface (Les Interfaces sur les Avions de Pointe: L’Aspect Machine de l’Interface Homme-Machine)

DTIC Science & Technology

1992-10-01

Manager , Advanced Transport Operating Systems Program Office Langley Research Center Mail Stop 265 Hampton, VA 23665-5225 United States Programme Committee...J.H.Lind, and C.G.Burge Advanced Cockpit - Mission and Image Management 4 by J. Struck Aircrew Acceptance of Automation in the Cockpit 5 by M. Hicks and I...DESIGN CONCEPTS AND TOOLS A Systems Approach to the Advanced Aircraft Man-Machine Interface 23 by F. Armogida Management of Avionics Data in the Cockpit

Addressing System Reconfiguration and Incremental Integration within IMA Systems

NASA Astrophysics Data System (ADS)

Ferrero, F.; Rodríques, A. I.

2009-05-01

Recently space industry is paying special attention to Integrated Modular Avionics (IMA) systems due to the benefits that modular concepts could bring to the development of space applications, especially in terms of interoperability, flexibility and software reuse. Two important IMA goals to be highlighted are system reconfiguration, and incremental integration of new functionalities into a pre-existing system. The purpose of this paper is to show how system reconfiguration is conducted based on Allied Standard Avionics Architecture Council (ASAAC) concepts for IMA Systems. Besides, it aims to provide a proposal for addressing the incremental integration concept supported by our experience gained during European Technology Acquisition Program (ETAP) TDP1.7 programme. All these topics will be discussed taking into account safety issues and showing the blueprint as an appropriate technique to support these concepts.

Hepatitis C Virus: Viral Quasispecies and Genotypes

PubMed Central

Tsukiyama-Kohara, Kyoko; Kohara, Michinori

2017-01-01

Hepatitis C virus (HCV) mainly replicates in the cytoplasm, where it easily establishes persistent infection, resulting in chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma. Due to its high rate of mutation, HCV forms viral quasispecies, categorized based on the highly variable regions in the envelope protein and nonstructural 5A protein. HCV possesses seven major genotypes, among which genotype 1 is the most prevalent globally. The distribution of HCV genotypes varies based on geography, and each genotype has a different sensitivity to interferon treatment. Recently-developed direct-acting antivirals (DAAs), which target viral proteases or polymerases, mediate drastically better antiviral effects than previous therapeutics. Although treatment with DAAs has led to the development of drug-resistant HCV mutants, the most recently approved DAAs show improved pan-genomic activity, with a higher barrier to viral resistance. PMID:29271914

78 FR 65183 - Airworthiness Directives; ATR-GIE Avions de Transport Régional Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-31

... Airworthiness Directives; ATR--GIE Avions de Transport R[eacute]gional Airplanes AGENCY: Federal Aviation... airworthiness directive (AD) for certain ATR--GIE Avions de Transport R[eacute]gional Model ATR72-101, -201... service information identified in this AD, contact ATR--GIE Avions de Transport R[eacute]gional, 1, All...

Solving Autonomy Technology Gaps through Wireless Technology and Orion Avionics Architectural Principles

NASA Astrophysics Data System (ADS)

Black, Randy; Bai, Haowei; Michalicek, Andrew; Shelton, Blaine; Villela, Mark

2008-01-01

Currently, autonomy in space applications is limited by a variety of technology gaps. Innovative application of wireless technology and avionics architectural principles drawn from the Orion crew exploration vehicle provide solutions for several of these gaps. The Vision for Space Exploration envisions extensive use of autonomous systems. Economic realities preclude continuing the level of operator support currently required of autonomous systems in space. In order to decrease the number of operators, more autonomy must be afforded to automated systems. However, certification authorities have been notoriously reluctant to certify autonomous software in the presence of humans or when costly missions may be jeopardized. The Orion avionics architecture, drawn from advanced commercial aircraft avionics, is based upon several architectural principles including partitioning in software. Robust software partitioning provides "brick wall" separation between software applications executing on a single processor, along with controlled data movement between applications. Taking advantage of these attributes, non-deterministic applications can be placed in one partition and a "Safety" application created in a separate partition. This "Safety" partition can track the position of astronauts or critical equipment and prevent any unsafe command from executing. Only the Safety partition need be certified to a human rated level. As a proof-of-concept demonstration, Honeywell has teamed with the Ultra WideBand (UWB) Working Group at NASA Johnson Space Center to provide tracking of humans, autonomous systems, and critical equipment. Using UWB the NASA team can determine positioning to within less than one inch resolution, allowing a Safety partition to halt operation of autonomous systems in the event that an unplanned collision is imminent. Another challenge facing autonomous systems is the coordination of multiple autonomous agents. Current approaches address the issue as one of networking and coordination of multiple independent units, each with its own mission. As a proof-of-concept Honeywell is developing and testing various algorithms that lead to a deterministic, fault tolerant, reliable wireless backplane. Just as advanced avionics systems control several subsystems, actuators, sensors, displays, etc.; a single "master" autonomous agent (or base station computer) could control multiple autonomous systems. The problem is simplified to controlling a flexible body consisting of several sensors and actuators, rather than one of coordinating multiple independent units. By filling technology gaps associated with space based autonomous system, wireless technology and Orion architectural principles provide the means for decreasing operational costs and simplifying problems associated with collaboration of multiple autonomous systems.

Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) Project

NASA Technical Reports Server (NTRS)

Shively, Jay

2017-01-01

Over the past 5 years, the UAS integration into the NAS project has worked to reduce technical barriers to integration. A major focus of this work has been in support of RTCA SC-228. This committee has recently published the first UAS integration minimum performance standards (MOPS). This work has spanned detect and avoid (DAA) as well as command and control comm datalinks. I will discuss DAA efforts with focus on the human systems work. I will discuss how automation was discussed and addressed within this context. ICAO stood up a remotely piloted aircraft systems (RPAS) panel in 2014. They have developed an RPAS manual and are now working to revise existing annexes and standards and recommended practices. The Human In The System (HITS) has worked to infuse human factors guidelines into those documents. I will discuss that effort as well as how ICAO has defined and address autonomy. There is a great deal of interest in the control of multiple vehicles by a single operator. The UAS EXCOM Science and Research Panel (SARP) is holding a workshop on this topic in late June. I will discuss research performed on this topic when I worked for the Army and on-going work within the division and a NATO working group on Human-Autonomy Teaming.

An Evaluation of an Ada Implementation of the Rete Algorithm for Embedded Flight Processors

DTIC Science & Technology

1990-12-01

computers was desired. The VAX VMS operating system has many built-in methods for determining program performance (including VAX PCA), but these methods... overviev , of the target environment-- the MIL-STD-1750A VHSIC Avionic Modular Processor ( VA.IP, running under the Ada Avionics Real-Time Software (AARTS... computers . Mil-STD-1750A, the Air Force’s standard flight computer architecture, however, places severe constraints on applications software processing

Proteomic analysis of oil body membrane proteins accompanying the onset of desiccation phase during sunflower seed development

PubMed Central

Thakur, Anita; Bhatla, Satish C

2015-01-01

A noteworthy metabolic signature accompanying oil body (OB) biogenesis during oilseed development is associated with the modulation of the oil body membranes proteins. Present work focuses on 2-dimensional polyacrylamide gel electrophoresis (2-D PAGE)-based analysis of the temporal changes in the OB membrane proteins analyzed by LC-MS/MS accompanying the onset of desiccation (20–30 d after anthesis; DAA) in the developing seeds of sunflower (Helianthus annuus L.). Protein spots unique to 20–30 DAA stages were picked up from 2-D gels for identification and the identified proteins were categorized into 7 functional classes. These include proteins involved in energy metabolism, reactive oxygen scavenging, proteolysis and protein turnover, signaling, oleosin and oil body biogenesis-associated proteins, desiccation and cytoskeleton. At 30 DAA stage, exclusive expressions of enzymes belonging to energy metabolism, desiccation and cytoskeleton were evident which indicated an increase in the metabolic and enzymatic activity in the cells at this stage of seed development (seed filling). Increased expression of cruciferina-like protein and dehydrin at 30 DAA stage marks the onset of desiccation. The data has been analyzed and discussed to highlight desiccation stage-associated metabolic events during oilseed development. PMID:26786011

Restrictions for reimbursement of interferon-free direct-acting antiviral drugs for HCV infection in Europe.

PubMed

Marshall, Alison D; Cunningham, Evan B; Nielsen, Stine; Aghemo, Alessio; Alho, Hannu; Backmund, Markus; Bruggmann, Philip; Dalgard, Olav; Seguin-Devaux, Carole; Flisiak, Robert; Foster, Graham R; Gheorghe, Liana; Goldberg, David; Goulis, Ioannis; Hickman, Matthew; Hoffmann, Patrick; Jancorienė, Ligita; Jarcuska, Peter; Kåberg, Martin; Kostrikis, Leondios G; Makara, Mihály; Maimets, Matti; Marinho, Rui Tato; Matičič, Mojca; Norris, Suzanne; Ólafsson, Sigurður; Øvrehus, Anne; Pawlotsky, Jean-Michel; Pocock, James; Robaeys, Geert; Roncero, Carlos; Simonova, Marieta; Sperl, Jan; Tait, Michele; Tolmane, Ieva; Tomaselli, Stefan; van der Valk, Marc; Vince, Adriana; Dore, Gregory J; Lazarus, Jeffrey V; Grebely, Jason

2018-02-01

All-oral direct-acting antiviral drugs (DAAs) for hepatitis C virus, which have response rates of 95% or more, represent a major clinical advance. However, the high list price of DAAs has led many governments to restrict their reimbursement. We reviewed the availability of, and national criteria for, interferon-free DAA reimbursement among countries in the European Union and European Economic Area, and Switzerland. Reimbursement documentation was reviewed between Nov 18, 2016, and Aug 1, 2017. Primary outcomes were fibrosis stage, drug or alcohol use, prescriber type, and HIV co-infection restrictions. Among the 35 European countries and jurisdictions included, the most commonly reimbursed DAA was ombitasvir, paritaprevir, and ritonavir, with dasabuvir, and with or without ribavirin (33 [94%] countries and jurisdictions). 16 (46%) countries and jurisdictions required patients to have fibrosis at stage F2 or higher, 29 (83%) had no listed restrictions based on drug or alcohol use, 33 (94%) required a specialist prescriber, and 34 (97%) had no additional restrictions for people co-infected with HIV and hepatitis C virus. These findings have implications for meeting WHO targets, with evidence of some countries not following the 2016 hepatitis C virus treatment guidelines by the European Association for the Study of Liver. Copyright © 2018 Elsevier Ltd. All rights reserved.

How much of a problem is resistance in treating hepatitis C?

PubMed

Forton, Daniel M

2016-12-01

Directly acting antiviral drug (DAA) treatments represent a major advance in hepatitis C management, achieving virological cures in excess of 90%. When treatment failure occurs, it is mostly due to relapse with the emergence of resistance-associated variants. Data from in-vitro studies and clinical trials have enabled characterization of the amino acid substitutions in antiviral drug targets that confer reduced susceptibility to DAAs. These resistance-associated substitutions (RASs) may exist prior to treatment, and are associated with, but do not inevitably result in, treatment failure. The most important RASs with current regimens occur in the NS5A protein of viral variants, which may persist for years after treatment. The optimal strategy is to prevent resistance through administering the best treatment, appropriately matched to patient and virological characteristics, for example the presence of cirrhosis, prior exposure to interferon and so on. International treatment guidelines have been developed to select treatments, which may vary in duration and coadministration with ribavirin. Routine resistance testing prior to treatment of naive patients is not generally recommended. Next-generation DAAs will further reduce the emergence of RASs and, because of activity against RASs to currently used DAAs, will be used as rescue therapies for patients who have failed treatment.

Resistance Mechanisms in Hepatitis C Virus: implications for Direct-Acting Antiviral Use.

PubMed

Bagaglio, Sabrina; Uberti-Foppa, Caterina; Morsica, Giulia

2017-07-01

Multiple direct-acting antiviral (DAA)-based regimens are currently approved that provide one or more interferon-free treatment options for hepatitis C virus (HCV) genotypes (G) 1-6. The choice of a DAA regimen, duration of therapy, and use of ribavirin depends on multiple viral and host factors, including HCV genotype, the detection of resistance-associated amino acid (aa) substitutions (RASs), prior treatment experience, and presence of cirrhosis. In regard to viral factors that may guide the treatment choice, the most important is the infecting genotype because a number of DAAs are genotype-designed. The potency and the genetic barrier may also impact the choice of treatment. One important and debated possible virologic factor that may negatively influence the response to DAAs is the presence of baseline RASs. Baseline resistance testing is currently not routinely considered or recommended for initiating HCV treatment, due to the overall high response rates (sustained virological response >90%) obtained. Exceptions are patients infected by HCV G1a when initiating treatment with simeprevir and elbasvir/grazoprevir or in those with cirrhosis prior to daclatasvir/sofosbuvir treatment because of natural polymorphisms demonstrated in sites of resistance. On the basis of these observations, first-line strategies should be optimized to overcome treatment failure due to HCV resistance.

Real-world virological efficacy and safety of elbasvir and grazoprevir in patients with chronic hepatitis C virus genotype 1 infection in Japan.

PubMed

Toyoda, Hidenori; Atsukawa, Masanori; Takaguchi, Koichi; Senoh, Tomonori; Michitaka, Kojiro; Hiraoka, Atsushi; Fujioka, Shinichi; Kondo, Chisa; Okubo, Tomomi; Uojima, Haruki; Tada, Toshifumi; Yoneyama, Hirohito; Watanabe, Tsunamasa; Asano, Toru; Ishikawa, Toru; Tamai, Hideyuki; Abe, Hiroshi; Kato, Keizo; Tsuji, Kunihiko; Ogawa, Chikara; Shimada, Noritomo; Iio, Etsuko; Deguchi, Akihiro; Itobayashi, Ei; Mikami, Shigeru; Moriya, Akio; Okubo, Hironao; Tani, Joji; Tsubota, Akihito; Tanaka, Yasuhito; Masaki, Tsutomu; Iwakiri, Katsuhiko; Kumada, Takashi

2018-05-08

The real-world virological efficacy and safety of an interferon (IFN)-free direct-acting antiviral (DAA) therapy with elbasvir (EBR) and grazoprevir (GZR) were evaluated in Japanese patients chronically infected with hepatitis C virus (HCV) genotype 1. The rate of sustained virologic response (SVR) and safety were analyzed in patients who started the EBR/GZR regimen between November 2016 and July 2017. SVR rates were compared based on patient baseline characteristics. Overall, 371 of 381 patients (97.4%) achieved SVR. Multivariate analysis identified a history of failure to IFN-free DAA therapy and the presence of double resistance-associated substitutions (RASs) in HCV non-structural protein 5A (NS5A) as factors significantly associated with failure to EBR/GZR treatment. The SVR rates of patients with a history of IFN-free DAA therapy and those with double RASs were 55.6 and 63.6%, respectively. In all other subpopulations, the SVR rates were more than 90%. There were no severe adverse events associated with the treatment. The EBR/GZR regimen yielded high virological efficacy with acceptable safety. Patients with a history of failure to IFN-free DAA therapy or with double RASs in HCV-NS5A remained difficult to treat with this regimen.

Reactive Capture of Gold Nanoparticles by Strongly Physisorbed Monolayers on Graphite

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wei, Xiaoliang; Tong, Wenjun; Fidler, Vlastimil

2012-12-01

Anthracene Diels Alder adducts (DAa) bearing two long side chains (H-(CH2)22O(CH2)6OCH2-) at the 1- and 5-positions form self-assembled monolayers (SAMs) at the phenyloctane - highly oriented pyrolytic graphite (HOPG) interface. The long DAa side chains promote strong physisorption of the monolayer to HOPG and maintain the monolayer morphology upon rinsing or incubation in ethanol and air-drying of the substrate. Incorporating a carboxylic acid group on the DAa core enables capture of 1 - 4 nm diameter gold nanoparticles (AuNP) provided (i) the monolayer containing DAa-carboxylic acids is treated with Cu2+ ions and (ii) the organic coating on the AuNP containsmore » carboxylic acids (11-mercaptoundecanoic acid, MUA-AuNP). AuNP capture by the monolayer proceeds with formation of Cu2+ - carboxylate coordination complexes. The captured AuNP appear as mono- and multi-layered clusters at high coverage on HOPG. The surface density of the captured AuNPs can be adjusted from AuNP multi-layers to isolated AuNPs by varying incubation times, MUA-AuNP concentration, the number density of carboxylic acids in the monolayer, the number of MUA per AuNP, and the post-incubation treatments.« less

Directed Abelian algebras and their application to stochastic models.

PubMed

Alcaraz, F C; Rittenberg, V

2008-10-01

With each directed acyclic graph (this includes some D-dimensional lattices) one can associate some Abelian algebras that we call directed Abelian algebras (DAAs). On each site of the graph one attaches a generator of the algebra. These algebras depend on several parameters and are semisimple. Using any DAA, one can define a family of Hamiltonians which give the continuous time evolution of a stochastic process. The calculation of the spectra and ground-state wave functions (stationary state probability distributions) is an easy algebraic exercise. If one considers D-dimensional lattices and chooses Hamiltonians linear in the generators, in finite-size scaling the Hamiltonian spectrum is gapless with a critical dynamic exponent z=D. One possible application of the DAA is to sandpile models. In the paper we present this application, considering one- and two-dimensional lattices. In the one-dimensional case, when the DAA conserves the number of particles, the avalanches belong to the random walker universality class (critical exponent sigma_(tau)=32 ). We study the local density of particles inside large avalanches, showing a depletion of particles at the source of the avalanche and an enrichment at its end. In two dimensions we did extensive Monte-Carlo simulations and found sigma_(tau)=1.780+/-0.005 .

The Risky Business of Dopamine Agonists in Parkinson Disease and Impulse Control Disorders

PubMed Central

Claassen, Daniel O.; van den Wildenberg, Wery P.M.; Ridderinkhof, K. Richard; Jessup, Charles K.; Harrison, Madaline B.; Wooten, G. Frederick; Wylie, Scott A.

2011-01-01

Risk-taking behavior is characterized by pursuit of reward in spite of potential negative consequences. Dopamine neurotransmission along the mesocorticolimbic pathway is a potential modulator of risk behavior. In patients with Parkinson's Disease (PD), impulse control disorder (ICD) can result from dopaminergic medication use, particularly Dopamine Agonists (DAA). Behaviors associated with ICD include hypersexuality as well as compulsive gambling, shopping, and eating, and are potentially linked to alterations to risk processing. Using the Balloon Analogue Risk task, we assessed the role of agonist therapy on risk-taking behavior in PD patients with (n=22) and without (n=19) active ICD symptoms. Patients performed the task both ‘on’ and ‘off’ DAA. DAA increased risk-taking in PD patients with active ICD symptoms, but did not affect risk behavior of PD controls. DAA dose was also important in explaining risk behavior. Both groups similarly reduced their risk-taking in high compared to low risk conditions and following the occurrence of a negative consequence, suggesting that ICD patients do not necessarily differ in their ability to process and adjust to some aspects of negative consequences. Our findings suggest dopaminergic augmentation of risk-taking behavior as a potential contributing mechanism for the emergence of ICD in PD patients. PMID:21604834

Validation of multiprocessor systems

NASA Technical Reports Server (NTRS)

Siewiorek, D. P.; Segall, Z.; Kong, T.

1982-01-01

Experiments that can be used to validate fault free performance of multiprocessor systems in aerospace systems integrating flight controls and avionics are discussed. Engineering prototypes for two fault tolerant multiprocessors are tested.

Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) Project: Terminal Operations HITL 1: Primary Results

NASA Technical Reports Server (NTRS)

Rorie, Conrad; Fern, Lisa; Monk, Kevin; Roberts, Zach; Brandt, Summer

2017-01-01

This presentation covers the primary results of the Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) Project Terminal Operations Foundational Human-in-the-Loop (HITL) simulation. The study tasked 16 pilots (half with manned piloting experience, and the other half with unmanned piloting experience) with maintaining "well clear" from other traffic while performing three different types of approaches into the Santa Rosa airport. A detect and avoid (DAA) system was provided to pilots to assist their ability to manage separation. The DAA system used in this test conformed to the criteria defined by RTCA Special Committee 228 (SC-228) in their Phase 1 Minimum Operational Performance Standards (MOPS) for UAS intending to operate in the NAS. The Phase 1 system was not designed to account for terminal operations, focusing instead on en route operations. To account for this, three different alerting and guidance configurations were presently tested in order to determine their effect on pilots operating the system in the terminal area. Results indicated that pilots with the alerting and guidance condition that provided the least amount of assistance (fewer alert levels and guidance types) experienced slightly increased pilot response times and rates of losses of separation. Additional data is presented on the effects of approach type and descriptive data on pilot maneuver preferences and ATC interoperability.

A distributed agent architecture for real-time knowledge-based systems: Real-time expert systems project, phase 1

NASA Technical Reports Server (NTRS)

Lee, S. Daniel

1990-01-01

We propose a distributed agent architecture (DAA) that can support a variety of paradigms based on both traditional real-time computing and artificial intelligence. DAA consists of distributed agents that are classified into two categories: reactive and cognitive. Reactive agents can be implemented directly in Ada to meet hard real-time requirements and be deployed on on-board embedded processors. A traditional real-time computing methodology under consideration is the rate monotonic theory that can guarantee schedulability based on analytical methods. AI techniques under consideration for reactive agents are approximate or anytime reasoning that can be implemented using Bayesian belief networks as in Guardian. Cognitive agents are traditional expert systems that can be implemented in ART-Ada to meet soft real-time requirements. During the initial design of cognitive agents, it is critical to consider the migration path that would allow initial deployment on ground-based workstations with eventual deployment on on-board processors. ART-Ada technology enables this migration while Lisp-based technologies make it difficult if not impossible. In addition to reactive and cognitive agents, a meta-level agent would be needed to coordinate multiple agents and to provide meta-level control.

Avionics Architectures for Exploration: Ongoing Efforts in Human Spaceflight

NASA Technical Reports Server (NTRS)

Goforth, Montgomery B.; Ratliff, James E.; Hames, Kevin L.; Vitalpur, Sharada V.; Woodman, Keith L.

2014-01-01

The field of Avionics is advancing far more rapidly in terrestrial applications than in spaceflight applications. Spaceflight Avionics are not keeping pace with expectations set by terrestrial experience, nor are they keeping pace with the need for increasingly complex automation and crew interfaces as we move beyond Low Earth Orbit. NASA must take advantage of the strides being made by both space-related and terrestrial industries to drive our development and sustaining costs down. This paper describes ongoing efforts by the Avionics Architectures for Exploration (AAE) project chartered by NASA's Advanced Exploration Systems (AES) Program to evaluate new avionic architectures and technologies, provide objective comparisons of them, and mature selected technologies for flight and for use by other AES projects. The AAE project team includes members from most NASA centers, and from industry. It is our intent to develop a common core avionic system that has standard capabilities and interfaces, and contains the basic elements and functionality needed for any spacecraft. This common core will be scalable and tailored to specific missions. It will incorporate hardware and software from multiple vendors, and be upgradeable in order to infuse incremental capabilities and new technologies. It will maximize the use of reconfigurable open source software (e.g., Goddard Space Flight Center's (GSFC's) Core Flight Software (CFS)). Our long-term focus is on improving functionality, reliability, and autonomy, while reducing size, weight, and power. Where possible, we will leverage terrestrial commercial capabilities to drive down development and sustaining costs. We will select promising technologies for evaluation, compare them in an objective manner, and mature them to be available for future programs. The remainder of this paper describes our approach, technical areas of emphasis, integrated test experience and results as of mid-2014, and future plans. As a part of the AES Program, we are encouraged to set aggressive goals and fall short if necessary, rather than to set our sights too low. We are also asked to emphasize providing our personnel with hands-on experience in development, integration, and testing. That we have embraced both of these philosophies will be evident in the descriptions below.

Modular, Cost-Effective, Extensible Avionics Architecture for Secure, Mobile Communications

NASA Technical Reports Server (NTRS)

Ivancic, William D.

2006-01-01

Current onboard communication architectures are based upon an all-in-one communications management unit. This unit and associated radio systems has regularly been designed as a one-off, proprietary system. As such, it lacks flexibility and cannot adapt easily to new technology, new communication protocols, and new communication links. This paper describes the current avionics communication architecture and provides a historical perspective of the evolution of this system. A new onboard architecture is proposed that allows full use of commercial-off-the-shelf technologies to be integrated in a modular approach thereby enabling a flexible, cost-effective and fully deployable design that can take advantage of ongoing advances in the computer, cryptography, and telecommunications industries.

Modular, Cost-Effective, Extensible Avionics Architecture for Secure, Mobile Communications

NASA Technical Reports Server (NTRS)

Ivancic, William D.

2007-01-01

Current onboard communication architectures are based upon an all-in-one communications management unit. This unit and associated radio systems has regularly been designed as a one-off, proprietary system. As such, it lacks flexibility and cannot adapt easily to new technology, new communication protocols, and new communication links. This paper describes the current avionics communication architecture and provides a historical perspective of the evolution of this system. A new onboard architecture is proposed that allows full use of commercial-off-the-shelf technologies to be integrated in a modular approach thereby enabling a flexible, cost-effective and fully deployable design that can take advantage of ongoing advances in the computer, cryptography, and telecommunications industries.

Implementation of an optimum profile guidance system on STOLAND

NASA Technical Reports Server (NTRS)

Flanagan, P. F.

1978-01-01

The implementation on the STOLAND airborne digital computer of an optimum profile guidance system for the augmentor wing jet STOL research aircraft is described. Major tasks were to implement the guidance and control logic to airborne computer software and to integrate the module with the existing STOLAND navigation, display, and autopilot routines. The optimum profile guidance system comprises an algorithm for synthesizing mimimum fuel trajectories for a wide range of starting positions in the terminal area and a control law for flying the aircraft automatically along the trajectory. The avionics software developed is described along with a FORTRAN program that was constructed to reflect the modular nature and algorthms implemented in the avionics software.

Evolution of shuttle avionics redundancy management/fault tolerance

NASA Technical Reports Server (NTRS)

Boykin, J. C.; Thibodeau, J. R.; Schneider, H. E.

1985-01-01

The challenge of providing redundancy management (RM) and fault tolerance to meet the Shuttle Program requirements of fail operational/fail safe for the avionics systems was complicated by the critical program constraints of weight, cost, and schedule. The basic and sometimes false effectivity of less than pure RM designs is addressed. Evolution of the multiple input selection filter (the heart of the RM function) is discussed with emphasis on the subtle interactions of the flight control system that were found to be potentially catastrophic. Several other general RM development problems are discussed, with particular emphasis on the inertial measurement unit RM, indicative of the complexity of managing that three string system and its critical interfaces with the guidance and control systems.

Two designs for an orbital transfer vehicle

NASA Technical Reports Server (NTRS)

Davis, Richard; Duquette, Miles; Fredrick, Rebecca; Schumacher, Daniel; Somers, Schaeffer; Stafira, Stanley; Williams, James; Zelinka, Mark

1988-01-01

The Orbital Transfer Vehicle (OTV) and systems were researched in the following areas: avionics, crew systems, electrical power systems, environmental control/life support systems, navigation and orbital maneuvers, propulsion systems, reaction control systems (RCS), servicing systems, and structures.

Forecast of the general aviation air traffic control environment for the 1980's

NASA Technical Reports Server (NTRS)

Hoffman, W. C.; Hollister, W. M.

1976-01-01

The critical information required for the design of a reliable, low cost, advanced avionics system which would enhance the safety and utility of general aviation is stipulated. Sufficient data is accumulated upon which industry can base the design of a reasonably priced system having the capability required by general aviation in and beyond the 1980's. The key features of the Air Traffic Control (ATC) system are: a discrete address beacon system, a separation assurance system, area navigation, a microwave landing system, upgraded ATC automation, airport surface traffic control, a wake vortex avoidance system, flight service stations, and aeronautical satellites. The critical parameters that are necessary for component design are identified. The four primary functions of ATC (control, surveillance, navigation, and communication) and their impact on the onboard avionics system design are assessed.

The Legacy of Space Shuttle Flight Software

NASA Technical Reports Server (NTRS)

Hickey, Christopher J.; Loveall, James B.; Orr, James K.; Klausman, Andrew L.

2011-01-01

The initial goals of the Space Shuttle Program required that the avionics and software systems blaze new trails in advancing avionics system technology. Many of the requirements placed on avionics and software were accomplished for the first time on this program. Examples include comprehensive digital fly-by-wire technology, use of a digital databus for flight critical functions, fail operational/fail safe requirements, complex automated redundancy management, and the use of a high-order software language for flight software development. In order to meet the operational and safety goals of the program, the Space Shuttle software had to be extremely high quality, reliable, robust, reconfigurable and maintainable. To achieve this, the software development team evolved a software process focused on continuous process improvement and defect elimination that consistently produced highly predictable and top quality results, providing software managers the confidence needed to sign each Certificate of Flight Readiness (COFR). This process, which has been appraised at Capability Maturity Model (CMM)/Capability Maturity Model Integration (CMMI) Level 5, has resulted in one of the lowest software defect rates in the industry. This paper will present an overview of the evolution of the Primary Avionics Software System (PASS) project and processes over thirty years, an argument for strong statistical control of software processes with examples, an overview of the success story for identifying and driving out errors before flight, a case study of the few significant software issues and how they were either identified before flight or slipped through the process onto a flight vehicle, and identification of the valuable lessons learned over the life of the project.

Towards Prognostics for Electronics Components

NASA Technical Reports Server (NTRS)

Saha, Bhaskar; Celaya, Jose R.; Wysocki, Philip F.; Goebel, Kai F.

2013-01-01

Electronics components have an increasingly critical role in avionics systems and in the development of future aircraft systems. Prognostics of such components is becoming a very important research field as a result of the need to provide aircraft systems with system level health management information. This paper focuses on a prognostics application for electronics components within avionics systems, and in particular its application to an Isolated Gate Bipolar Transistor (IGBT). This application utilizes the remaining useful life prediction, accomplished by employing the particle filter framework, leveraging data from accelerated aging tests on IGBTs. These tests induced thermal-electrical overstresses by applying thermal cycling to the IGBT devices. In-situ state monitoring, including measurements of steady-state voltages and currents, electrical transients, and thermal transients are recorded and used as potential precursors of failure.

Analysis of Organic Acids, Deacetyl Asperulosidic Acid and Polyphenolic Compounds as a Potential Tool for Characterization of Noni (Morinda citrifolia) Products.

PubMed

Bittová, Miroslava; Hladůkova, Dita; Roblová, Vendula; Krácmar, Stanislav; Kubán, Petr; Kubán, Vlastimil

2015-11-01

Organic acids, deacetyl asperulosidic acid (DAA) and polyphenolic compounds in various noni (Morinda citrifolia L.) products (4 juices, 4 dry fruit powders and 2 capsules with dry fruit powder) were analyzed. Reversed-phase high-performance liquid chromatography (RP-HPLC) coupled with a variable wavelength detector (VWD) and electrospray ionization time-of-flight mass spectrometer (ESI-TOF MS) was applied for simultaneous analysis of organic acids (malic, lactic, citric and succinic acid) and DAA. An RP-HPLC method with diode-array detector (DAD) was developed for the analysis of polyphenolic compound content (rutin, catechin, quercitrin, kaempferol, gallic acid, caffeic acid and p-coumaric acid). The developed methods can contribute to better characterization of available noni products that is required from the consumers. In our study, we discovered significant dissimilarities in the content of DAA, citric acid and several phenolic compounds in some samples.

Sequencing of hepatitis C virus for detection of resistance to direct-acting antiviral therapy: A systematic review.

PubMed

Bartlett, Sofia R; Grebely, Jason; Eltahla, Auda A; Reeves, Jacqueline D; Howe, Anita Y M; Miller, Veronica; Ceccherini-Silberstein, Francesca; Bull, Rowena A; Douglas, Mark W; Dore, Gregory J; Harrington, Patrick; Lloyd, Andrew R; Jacka, Brendan; Matthews, Gail V; Wang, Gary P; Pawlotsky, Jean-Michel; Feld, Jordan J; Schinkel, Janke; Garcia, Federico; Lennerstrand, Johan; Applegate, Tanya L

2017-07-01

The significance of the clinical impact of direct-acting antiviral (DAA) resistance-associated substitutions (RASs) in hepatitis C virus (HCV) on treatment failure is unclear. No standardized methods or guidelines for detection of DAA RASs in HCV exist. To facilitate further evaluations of the impact of DAA RASs in HCV, we conducted a systematic review of RAS sequencing protocols, compiled a comprehensive public library of sequencing primers, and provided expert guidance on the most appropriate methods to screen and identify RASs. The development of standardized RAS sequencing protocols is complicated due to a high genetic variability and the need for genotype- and subtype-specific protocols for multiple regions. We have identified several limitations of the available methods and have highlighted areas requiring further research and development. The development, validation, and sharing of standardized methods for all genotypes and subtypes should be a priority. ( Hepatology Communications 2017;1:379-390).

Orion GN and C Mitigation Efforts for Van Allen Radiation

NASA Technical Reports Server (NTRS)

King, Ellis T.; Jackson, Mark

2013-01-01

The Orion Crew Module (CM) is NASA's next generation manned space vehicle, scheduled to return humans to lunar orbit in the coming decade. The Orion avionics and GN&C architectures have progressed through a number of project phases and are nearing completion of a major milestone. The first unmanned test mission, dubbed "Exploration Flight Test One" (EFT-1) is scheduled to launch from NASA Kennedy Space Center late next year and provides the first integrated test of all the vehicle systems, avionics and software.

Autonomous Flight Rules Concept: User Implementation Costs and Strategies

NASA Technical Reports Server (NTRS)

Cotton, William B.; Hilb, Robert

2014-01-01

The costs to implement Autonomous Flight Rules (AFR) were examined for estimates in acquisition, installation, training and operations. The user categories were airlines, fractional operators, general aviation and unmanned aircraft systems. Transition strategies to minimize costs while maximizing operational benefits were also analyzed. The primary cost category was found to be the avionics acquisition. Cost ranges for AFR equipment were given to reflect the uncertainty of the certification level for the equipment and the extent of existing compatible avionics in the aircraft to be modified.

SSTAC/ARTS review of the draft Integrated Technology Plan (ITP). Volume 6: Controls and guidance

NASA Technical Reports Server (NTRS)

1991-01-01

Viewgraphs of briefings from the Space Systems and Technology Advisory Committee (SSTAC)/ARTS review of the draft Integrated Technology Plan (ITP) on controls and guidance are included. Topics covered include: strategic avionics technology planning and bridging programs; avionics technology plan; vehicle health management; spacecraft guidance research; autonomous rendezvous and docking; autonomous landing; computational control; fiberoptic rotation sensors; precision instrument and telescope pointing; microsensors and microinstruments; micro guidance and control initiative; and earth-orbiting platforms controls-structures interaction.

Advanced Concepts for Avionics/Weapon System Design, Development and Integration: Conference Proceedings of the Avionics Panel Symposium (45th) Held at Ottawa, Canada on 18-22 April 1983.

DTIC Science & Technology

1983-10-01

BIT A,, M 115V ACBB N 270V DC RETURN p 115V ACCA R IW DC POWER S INTERLOCK RETURN T STRUCTURE GROUND U FIBER OPTICS BUS V ADDRESS BIT A,, w...Ontario Kl A 0K2 Canada FGAN- FFM , D-5307 Wachtberg-Werthhoven Germany Concordia University, 7141 Sherbrooke St. W. Montreal, QueH4BlRG Canada

Refractive Conditions of Amazon Environment and Its Effects on Ground and Airborne Radar and ESM Systems

DTIC Science & Technology

2003-09-01

superrefraction and trapping layers (the last one forming ducts) were investigated , as well as multiple layers. The multiple layers studied were made by 18...and Surveillance for the Amazon. Avionics Magazine of June 2002, from: http://www.aviationtoday.com/reports/avionics/previous/0602/0602sivam.htm...2003. Fisch, G., Marengo, J. A., & Nobre, C. A. Climate in Amazonia . From: http://www.mct.gov.br/clima/ingles/comunic_old/cinpe03.htm accessed in

NASA Controller Acceptability Study 1(CAS-1) Experiment Description and Initial Observations

NASA Technical Reports Server (NTRS)

Chamberlain, James P.; Consiglio, Maria C.; Comstock, James R., Jr.; Ghatas, Rania W.; Munoz, Cesar

2015-01-01

This paper describes the Controller Acceptability Study 1 (CAS-1) experiment that was conducted by NASA Langley Research Center personnel from January through March 2014 and presents partial CAS-1 results. CAS-1 employed 14 air traffic controller volunteers as research subjects to assess the viability of simulated future unmanned aircraft systems (UAS) operating alongside manned aircraft in moderate-density, moderate-complexity Class E airspace. These simulated UAS were equipped with a prototype pilot-in-the-loop (PITL) Detect and Avoid (DAA) system, specifically the Self-Separation (SS) function of such a system based on Stratway+ software to replace the see-and-avoid capabilities of manned aircraft pilots. A quantitative CAS-1 objective was to determine horizontal miss distance (HMD) values for SS encounters that were most acceptable to air traffic controllers, specifically HMD values that were assessed as neither unsafely small nor disruptively large. HMD values between 0.5 and 3.0 nautical miles (nmi) were assessed for a wide array of encounter geometries between UAS and manned aircraft. The paper includes brief introductory material about DAA systems and their SS functions, followed by descriptions of the CAS-1 simulation environment, prototype PITL SS capability, and experiment design, and concludes with presentation and discussion of partial CAS-1 data and results.

An ontology-based semantic configuration approach to constructing Data as a Service for enterprises

NASA Astrophysics Data System (ADS)

Cai, Hongming; Xie, Cheng; Jiang, Lihong; Fang, Lu; Huang, Chenxi

2016-03-01

To align business strategies with IT systems, enterprises should rapidly implement new applications based on existing information with complex associations to adapt to the continually changing external business environment. Thus, Data as a Service (DaaS) has become an enabling technology for enterprise through information integration and the configuration of existing distributed enterprise systems and heterogonous data sources. However, business modelling, system configuration and model alignment face challenges at the design and execution stages. To provide a comprehensive solution to facilitate data-centric application design in a highly complex and large-scale situation, a configurable ontology-based service integrated platform (COSIP) is proposed to support business modelling, system configuration and execution management. First, a meta-resource model is constructed and used to describe and encapsulate information resources by way of multi-view business modelling. Then, based on ontologies, three semantic configuration patterns, namely composite resource configuration, business scene configuration and runtime environment configuration, are designed to systematically connect business goals with executable applications. Finally, a software architecture based on model-view-controller (MVC) is provided and used to assemble components for software implementation. The result of the case study demonstrates that the proposed approach provides a flexible method of implementing data-centric applications.

General aviation avionics equipment maintenance

NASA Technical Reports Server (NTRS)

Parker, C. D.; Tommerdahl, J. B.

1978-01-01

Maintenance of general aviation avionics equipment was investigated with emphasis on single engine and light twin engine general aviation aircraft. Factors considered include the regulatory agencies, avionics manufacturers, avionics repair stations, the statistical character of the general aviation community, and owners and operators. The maintenance, environment, and performance, repair costs, and reliability of avionics were defined. It is concluded that a significant economic stratification is reflected in the maintenance problems encountered, that careful attention to installations and use practices can have a very positive impact on maintenance problems, and that new technologies and a general growth in general aviation will impact maintenance.

IVHM Framework for Intelligent Integration for Vehicle Health Management

NASA Technical Reports Server (NTRS)

Paris, Deidre; Trevino, Luis C.; Watson, Michael D.

2005-01-01

Integrated Vehicle Health Management (IVHM) systems for aerospace vehicles, is the process of assessing, preserving, and restoring system functionality across flight and techniques with sensor and communication technologies for spacecraft that can generate responses through detection, diagnosis, reasoning, and adapt to system faults in support of Integrated Intelligent Vehicle Management (IIVM). These real-time responses allow the IIVM to modify the affected vehicle subsystem(s) prior to a catastrophic event. Furthermore, this framework integrates technologies which can provide a continuous, intelligent, and adaptive health state of a vehicle and use this information to improve safety and reduce costs of operations. Recent investments in avionics, health management, and controls have been directed towards IIVM. As this concept has matured, it has become clear that IIVM requires the same sensors and processing capabilities as the real-time avionics functions to support diagnosis of subsystem problems. New sensors have been proposed, in addition to augment the avionics sensors to support better system monitoring and diagnostics. As the designs have been considered, a synergy has been realized where the real-time avionics can utilize sensors proposed for diagnostics and prognostics to make better real-time decisions in response to detected failures. IIVM provides for a single system allowing modularity of functions and hardware across the vehicle. The framework that supports IIVM consists of 11 major on-board functions necessary to fully manage a space vehicle maintaining crew safety and mission objectives. These systems include the following: Guidance and Navigation; Communications and Tracking; Vehicle Monitoring; Information Transport and Integration; Vehicle Diagnostics; Vehicle Prognostics; Vehicle Mission Planning, Automated Repair and Replacement; Vehicle Control; Human Computer Interface; and Onboard Verification and Validation. Furthermore, the presented framework provides complete vehicle management which not only allows for increased crew safety and mission success through new intelligence capabilities, but also yields a mechanism for more efficient vehicle operations.

Managing Complexity in the MSL/Curiosity Entry, Descent, and Landing Flight Software and Avionics Verification and Validation Campaign

NASA Technical Reports Server (NTRS)

Stehura, Aaron; Rozek, Matthew

2013-01-01

The complexity of the Mars Science Laboratory (MSL) mission presented the Entry, Descent, and Landing systems engineering team with many challenges in its Verification and Validation (V&V) campaign. This paper describes some of the logistical hurdles related to managing a complex set of requirements, test venues, test objectives, and analysis products in the implementation of a specific portion of the overall V&V program to test the interaction of flight software with the MSL avionics suite. Application-specific solutions to these problems are presented herein, which can be generalized to other space missions and to similar formidable systems engineering problems.

Advanced Software Techniques for Data Management Systems. Volume 2: Space Shuttle Flight Executive System: Functional Design

NASA Technical Reports Server (NTRS)

Pepe, J. T.

1972-01-01

A functional design of software executive system for the space shuttle avionics computer is presented. Three primary functions of the executive are emphasized in the design: task management, I/O management, and configuration management. The executive system organization is based on the applications software and configuration requirements established during the Phase B definition of the Space Shuttle program. Although the primary features of the executive system architecture were derived from Phase B requirements, it was specified for implementation with the IBM 4 Pi EP aerospace computer and is expected to be incorporated into a breadboard data management computer system at NASA Manned Spacecraft Center's Information system division. The executive system was structured for internal operation on the IBM 4 Pi EP system with its external configuration and applications software assumed to the characteristic of the centralized quad-redundant avionics systems defined in Phase B.

Custom avionics-grade AM LCDs for high performance military and avionics applications

NASA Astrophysics Data System (ADS)

Niemczyk, James

2003-09-01

American Panel Corporation in Alpharetta Georgia and LG-Philips-LCD in Seoul South Korea have a strategic alliance for the design and manufacture of custom AMLCD products targeted for the military vehicle and avionics sector. As part of this relationship, new innovations in AMLCD technology specifically aimed at the rugged and avionics applications have been developed and are now brought to the marketplace

Final Environmental Assessment: Installation of Digital Airport Surveillance Radar at Grand Forks Air Force Base, North Dakota

DTIC Science & Technology

2011-05-11

the installation of DOD Advanced Automation Systems (DAAS) and Voice Communications Switching Systems (VCSS) at DOD bases, was previously evaluated...utilities installed immediately next to the site. Operation of the DASR system is anticipated to have minimal long-term impacts to the natural and human ... humans at ground level and is not anticipated to pose ha1m to the general population. During operation of the DASR system, fuel will be stored in

CanOpen on RASTA: The Integration of the CanOpen IP Core in the Avionics Testbed

NASA Astrophysics Data System (ADS)

Furano, Gianluca; Guettache, Farid; Magistrati, Giorgio; Tiotto, Gabriele; Ortega, Carlos Urbina; Valverde, Alberto

2013-08-01

This paper presents the work done within the ESA Estec Data Systems Division, targeting the integration of the CanOpen IP Core with the existing Reference Architecture Test-bed for Avionics (RASTA). RASTA is the reference testbed system of the ESA Avionics Lab, designed to integrate the main elements of a typical Data Handling system. It aims at simulating a scenario where a Mission Control Center communicates with on-board computers and systems through a TM/TC link, thus providing the data management through qualified processors and interfaces such as Leon2 core processors, CAN bus controllers, MIL-STD-1553 and SpaceWire. This activity aims at the extension of the RASTA with two boards equipped with HurriCANe controller, acting as CANOpen slaves. CANOpen software modules have been ported on the RASTA system I/O boards equipped with Gaisler GR-CAN controller and acts as master communicating with the CCIPC boards. CanOpen serves as upper application layer for based on CAN defined within the CAN-in-Automation standard and can be regarded as the definitive standard for the implementation of CAN-based systems solutions. The development and integration of CCIPC performed by SITAEL S.p.A., is the first application that aims to bring the CANOpen standard for space applications. The definition of CANOpen within the European Cooperation for Space Standardization (ECSS) is under development.

IS INCREASED HCV CASE-FINDING COMBINED WITH CURRENT OR 8–12 WEEK DAA THERAPY COST-EFFECTIVE IN UK PRISONS? A PREVENTION BENEFIT ANALYSIS

PubMed Central

Martin, Natasha K; Vickerman, Peter; Brew, Iain F; Williamson, Joan; Miners, Alec; Irving, William L; Saksena, Sushma; Hutchinson, Sharon J; Mandal, Sema; O’Moore, Eamonn; Hickman, Matthew

2016-01-01

Background Prisoners have a high prevalence of Hepatitis C virus (HCV), but case-finding may not have been cost-effective because treatment often exceeded average prison stay combined with a lack of continuity-of-care. We assess the cost-effectiveness of increased HCV case-finding and treatment in UK prisons using short-course therapies. Methods A dynamic HCV transmission model assesses the cost-effectiveness of doubling HCV case-finding (achieved through introducing opt-out HCV testing in UK pilot prisons) and increasing treatment in UK prisons, compared to status-quo voluntary risk-based testing (6% prison entrants/year), using currently recommended therapies (8–24 weeks) or IFN-free DAAs (8–12 weeks, 95% SVR, £3300/wk). Costs (GBP£) and health utilities (quality-adjusted life-years, QALYs) were used to calculate mean incremental cost-effectiveness ratios (ICERs). We assume 56% referral and 2.5%/25% of referred people who inject drugs (PWID)/exPWID treated within 2 months of diagnosis in prison. PWID and ex/nonPWID are in prison an average 4/8 months, respectively. Results Doubling prison testing rates with existing treatments produces a mean ICER of £19,850/QALY gained compared to current testing/treatment, and is 45% likely to be cost-effective under a £20,000 willingness-to-pay (WTP) threshold. Switching to 8–12 week IFN-free DAAs in prisons could increase cost-effectiveness (ICER £15,090/QALY gained). Excluding prevention benefit decreases cost-effectiveness. If >10% referred PWID are treated in prison (2.5% base-case), either treatment could be highly cost-effective (ICER<£13,000). HCV case-finding and IFN-free DAAs could be highly cost-effective if DAA cost is 10% lower or 8 weeks duration. Conclusions Increased HCV testing in UK prisons (such as through opt-out testing) is borderline cost-effective compared to status-quo voluntary risk-based testing under a £20,000 WTP with current treatments, but likely to be cost-effective if short-course IFN-free DAAs are used, and could be highly cost-effective if PWID treatment rates were increased. PMID:26864802

An electronic flight bag for NextGen avionics

NASA Astrophysics Data System (ADS)

Zelazo, D. Eyton

2012-06-01

The introduction of the Next Generation Air Transportation System (NextGen) initiative by the Federal Aviation Administration (FAA) will impose new requirements for cockpit avionics. A similar program is also taking place in Europe by the European Organisation for the Safety of Air Navigation (Eurocontrol) called the Single European Sky Air Traffic Management Research (SESAR) initiative. NextGen will require aircraft to utilize Automatic Dependent Surveillance-Broadcast (ADS-B) in/out technology, requiring substantial changes to existing cockpit display systems. There are two ways that aircraft operators can upgrade their aircraft in order to utilize ADS-B technology. The first is to replace existing primary flight displays with new displays that are ADS-B compatible. The second, less costly approach is to install an advanced Class 3 Electronic Flight Bag (EFB) system. The installation of Class 3 EFBs in the cockpit will allow aircraft operators to utilize ADS-B technology in a lesser amount of time with a decreased cost of implementation and will provide additional benefits to the operator. This paper describes a Class 3 EFB, the NexisTM Flight-Intelligence System, which has been designed to allow users a direct interface with NextGen avionics sensors while additionally providing the pilot with all the necessary information to meet NextGen requirements.

14 CFR § 1215.114 - Service rates.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 5 2014-01-01 2014-01-01 false Service rates. § 1215.114 Section § 1215... SATELLITE SYSTEM (TDRSS) Use and Reimbursement Policy for Non-U.S. Government Users § 1215.114 Service rates. (a) Rates for TDRSS services will be established by the DAA for SCaN. (b) Per-minute rates will...

General Aviation Avionics Statistics : 1975

DOT National Transportation Integrated Search

1978-06-01

This report presents avionics statistics for the 1975 general aviation (GA) aircraft fleet and updates a previous publication, General Aviation Avionics Statistics: 1974. The statistics are presented in a capability group framework which enables one ...

Methodologie experimentale pour evaluer les caracteristiques des plateformes graphiques avioniques

NASA Astrophysics Data System (ADS)

Legault, Vincent

Within a context where the aviation industry intensifies the development of new visually appealing features and where time-to-market must be as short as possible, rapid graphics processing benchmarking in a certified avionics environment becomes an important issue. With this work we intend to demonstrate that it is possible to deploy a high-performance graphics application on an avionics platform that uses certified graphical COTS components. Moreover, we would like to bring to the avionics community a methodology which will allow developers to identify the needed elements for graphics system optimisation and provide them tools that can measure the complexity of this type of application and measure the amount of resources to properly scale a graphics system according to their needs. As far as we know, no graphics performance profiling tool dedicated to critical embedded architectures has been proposed. We thus had the idea of implementing a specialized benchmarking tool that would be an appropriate and effective solution to this problem. Our solution resides in the extraction of the key graphics specifications from an inherited application to use them afterwards in a 3D image generation application.

Avionics for a Small Robotic Inspection Spacecraft

NASA Technical Reports Server (NTRS)

Abbott, Larry; Shuler, Robert L., Jr.

2005-01-01

A report describes the tentative design of the avionics of the Mini-AERCam -- a proposed 7.5-in. (approximately 19-cm)-diameter spacecraft that would contain three digital video cameras to be used in visual inspection of the exterior of a larger spacecraft (a space shuttle or the International Space Station). The Mini-AERCam would maneuver by use of its own miniature thrusters under radio control by astronauts inside the larger spacecraft. The design of the Mini-AERCam avionics is subject to a number of constraints, most of which can be summarized as severely competing requirements to maximize radiation hardness and maneuvering, image-acquisition, and data-communication capabilities while minimizing cost, size, and power consumption. The report discusses the design constraints, the engineering approach to satisfying the constraints, and the resulting iterations of the design. The report places special emphasis on the design of a flight computer that would (1) acquire position and orientation data from a Global Positioning System receiver and a microelectromechanical gyroscope, respectively; (2) perform all flight-control (including thruster-control) computations in real time; and (3) control video, tracking, power, and illumination systems.

Treatment of chronic hepatitis C in patients with HIV/HCV coinfection

PubMed Central

Coppola, Nicola; Martini, Salvatore; Pisaturo, Mariantonietta; Sagnelli, Caterina; Filippini, Pietro; Sagnelli, Evangelista

2015-01-01

Hepatitis C virus (HCV) infection is one of the most frequent causes of comorbidity and mortality in the human immunodeficiency virus (HIV) population, and liver-related mortality is now the second highest cause of death in HIV-positive patients, so HCV infection should be countered with adequate antiviral therapy. In 2011 began the era of directly acting antivirals (DAAs) and the HCV NS3/4A protease inhibitors telaprevir and boceprevir were approved to treat HCV-genotype-1 infection, each one in combination with pegylated interferon alfa (Peg-IFN) + ribavirin (RBV). The addition of the first generation DAAs, strongly improved the efficacy of antiviral therapy in patients with HCV-genotype 1, both for the HCV-monoinfected and HIV/HCV coinfected, and the poor response to Peg-IFN + RBV in HCV/HIV coinfection was enhanced. These treatments showed higher rates of sustained virological response than Peg-IFN + RBV but reduced tolerability and adherence due to the high pill burden and the several pharmacokinetic interactions between HCV NS3/4A protease inhibitors and antiretroviral drugs. Then in 2013 a new wave of DAAs arrived, characterized by high efficacy, good tolerability, a low pill burden and shortened treatment duration. The second and third generation DAAs also comprised IFN-free regimens, which in small recent trials on HIV-positive patients have shown comforting preliminary results in terms of efficacy, tolerability and adherence. PMID:25674512

Temporal and Spatial Patterns of Accumulation of the Transcript of Myo-Inositol-1-Phosphate Synthase and Phytin-Containing Particles during Seed Development in Rice1

PubMed Central

Yoshida, Kaoru T.; Wada, Tomikichi; Koyama, Hiroshi; Mizobuchi-Fukuoka, Ritsuko; Naito, Satoshi

1999-01-01

Myo-inositol-1-phosphate (I[1]P) synthase (EC 5.5.1.4) catalyzes the reaction from glucose 6-phosphate to I(1)P, the first step of myo-inositol biosynthesis. Among the metabolites of I(1)P is inositol hexakisphosphate, which forms a mixed salt called phytin or phytate, a storage form of phosphate and cations in seeds. We have isolated a rice (Oryza sativa L.) cDNA clone, pRINO1, that is highly homologous to the I(1)P synthase from yeast and plants. Northern analysis of total RNA showed that the transcript accumulated to high levels in embryos but was undetectable in shoots, roots, and flowers. In situ hybridization of developing seeds showed that the transcript first appeared in the apical region of globular-stage embryos 2 d after anthesis (DAA). Strong signals were detected in the scutellum and aleurone layer after 4 DAA. The level of the transcript in these cells increased until 7 DAA, after which time it gradually decreased. Phytin-containing particles called globoids appeared 4 DAA in the scutellum and aleurone layer, coinciding with the localization of the RINO1 transcript. The temporal and spatial patterns of accumulation of the RINO1 transcript and globoids suggest that I(1)P synthase directs phytin biosynthesis in rice seeds. PMID:9880347

Deduced catalytic mechanism of d-amino acid amidase from Ochrobactrum anthropi SV3

PubMed Central

Okazaki, Seiji; Suzuki, Atsuo; Komeda, Hidenobu; Asano, Yasuhisa; Yamane, Takashi

2008-01-01

d-Amino acid amidase (DAA) from Ochrobactrum anthropi SV3 catalyzes d-stereospecific hydrolysis of amino acid amides. DAA has attracted attention as a catalyst for the stereospecific production of d-amino acids, although the mechanism that drives the reaction has not been clear. Previously, the structure of DAA was classified into two types, a substrate-bound state with an ordered Ω loop, and a ground state with a disordered Ω loop. Because the binding of the substrate facilitates ordering, this transition was regarded to be induced fit motion. The angles and distances of hydrogen bonds at Tyr149 Oη, Ser60 Oγ and Lys63 Nζ revealed that Tyr149 Oη donates an H atom to a water molecule in the substrate-bound state, and that Tyr149 Oη donates an H atom to Ser60 Oγ or Lys63 Nζ in the ground state. Taking into consideration the locations of the H atoms of Tyr149 Oη, Ser60 Oγ and Lys63 Nζ, a catalytic mechanism of DAA activity is presented, wherein a shift of an H atom at Tyr149 Oη in the substrate-bound versus the ground state plays a significant role in the reaction. This mechanism explains well why acylation proceeds and deacylation does not proceed in the substrate-bound state. PMID:18421151

Effects of salt and waterlogging stresses and their combination on leaf photosynthesis, chloroplast ATP synthesis, and antioxidant capacity in wheat.

PubMed

Zheng, Chunfang; Jiang, Dong; Liu, Fulai; Dai, Tingbo; Jing, Qi; Cao, Weixing

2009-04-01

The objective of this study was to investigate the effects of salt (ST) and waterlogging (WL) stresses and their combination (SW) on leaf photosynthesis, chloroplast ATP synthesis, and antioxidant capacity in wheat (Triticum aestivum L.). Two winter wheat cultivars, Huaimai 17 and Yangmai 12, differing in their tolerance to ST and WL stresses were used. The plants were grown in pots and were subjected to ST, WL, and SW from 7 days after anthesis (DAA). The WL and SW treatments lasted for 5 days, while the ST treatment was continuously imposed during the grain filling stage. Significant decrease in net photosynthetic rate (PN) of the flag leaf was observed under the ST and SW treatments from 10 DAA in Yangmai 12 and at 18 DAA in both cultivars, which could be stomatal closure related. At 18 DAA, clear reduction in PN under the ST and SW treatments was observed, which was associated with chlorosis, damages to the photosystem II (PSII), enhanced lipid peroxidation, and depressed ATP synthesis in the chloroplasts of the flag leaf. Whereas, WL treatment alone had slightly negative effect on PN, which was mainly attributed to leaf chlorosis and waste in harvested energy by the PSII reaction center dispersed via non-photochemical approaches. Copyright © 2009 Elsevier Ireland Ltd. All rights reserved.

Impact of different sofosbuvir based treatment regimens on the biochemical profile of chronic hepatitis C genotype 4 patients.

PubMed

Elsharkawy, Aisha; Eletreby, Rasha; Fouad, Rabab; Soliman, Zeinab; Abdallah, Mohamed; Negm, Mohamed; Mohey, Mohammad; Esmat, Gamal

2017-08-01

Huge efforts have been made to control chronic HCV in Egypt with introduction of Direct-Acting Antivirals (DAAs). Current study aims at evaluating effect of various DAA regimens on liver biochemical profile and haematological indices during treatment. 272 patients with chronic HCV genotype 4 treated by different DAA regimens (SOF/RBV, SOF/DAC ± RBV, SOF/SIM) for a duration of 12 or 24 weeks in Kasr Alainy Viral Hepatitis Center, Cairo University were followed up for serum bilirubin (BIL), albumin (ALB), alanine transaminase (ALT), aspartate aminotransferase (AST), prothrombin concentration, international normalized ratio (INR), and CBC at baseline, week-4 and end of treatment. Mean age was 54 years. Males comprised 64.7%, 72.4% were treatment-naïve, 39% were cirrhotic. Overall SVR12 rate was (93.4%). With all regimens, ALT and AST declined after treatment. In cirrhotics, there was a rise in BIL and INR; with no change in ALB and a decrease in White blood cells. Drop in Hemoglobin and platelets in cirrhotic patients were noted with SOF/RBV, while SOF/SIM showed rise in BIL. DAAs are safe and effective in genotype 4 chronic HCV patients. It improves liver necro-inflammatory markers in cirrhotics and non-cirrhotics. Cirrhotic patients require careful observation being more vulnerable for treatment related complications.

Reactivation of Herpesvirus in Patients With Hepatitis C Treated With Direct-Acting Antiviral Agents.

PubMed

Perelló M, Christie; Fernández-Carrillo, Carlos; Londoño, María-Carlota; Arias-Loste, Teresa; Hernández-Conde, Marta; Llerena, Susana; Crespo, Javier; Forns, Xavier; Calleja, José Luis

2016-11-01

We performed a case-series analysis of reactivation of herpesvirus in patients with hepatitis C virus (HCV) infection treated with direct-acting antiviral (DAA) agents. We collected data from 576 patients with HCV infection treated with DAA combinations at 3 hospitals in Spain, from November 2014 through November 2015. We also collected data from a control population (230 HCV-infected patients, matched for sex and age; 23 untreated and 213 treated with interferon-based regimens). Herpesvirus was reactivated in 10 patients who received DAA therapy (7 patients had cirrhosis and 3 patients had received liver transplants), a median of 8 weeks after the therapy was initiated. None of the controls had herpesvirus reactivation. Patients with herpesvirus reactivation were receiving the DAA agents sofosbuvir with ledipasvir (with or without ribavirin, 7/10), ombitasvir with paritaprevir and ritonavir plus dasabuvir (with or without ribavirin, 2/10), or sofosbuvir with simeprevir plus ribavirin (1/10). Two of the 10 patients developed postherpetic neuralgia and 1 patient developed kerato-uveitis. All 10 patients with herpesvirus reactivation achieved a sustained virologic response. Immune changes that follow clearance of HCV might lead to reactivation of other viruses, such as herpesvirus. Patients with HCV infection suspected of having herpesvirus infection should be treated immediately. Some groups also might be screened for herpesvirus infection. Copyright © 2016 AGA Institute. Published by Elsevier Inc. All rights reserved.

Real-World Clinical Efficacy and Tolerability of Direct-Acting Antivirals in Hepatitis C Monoinfection Compared to Hepatitis C/HIV Coinfection in a Community Care Setting.

PubMed

Vijay, Gayam; Rajib, Hossain Muhammad; Mazin, Khalid; Sandipan, Chakaraborty; Osama, Mukhtar; Sumit, Dahal; Amrendra Kumar, Mandal; Arshpal, Gill; Pavani, Garlapati; Ramakrishnaiah, Sreedevi; Khalid, Mowyad; Jagannath, Sherigar; Mohammed, Mansour; Smruti, Mohanty

2018-06-22

Limited data exist comparing the safety and efficacy of direct-acting antivirals (DAAs) in hepatitis C virus (HCV) monoinfected and HCV/human immunodeficiency virus (HIV) coinfected patients in the real-world clinic practice setting. All HCV monoinfected and HCV/HIV coinfected patients treated with DAAs between January 2014 and October 2017 in community clinic settings were retrospectively analyzed. Pretreatment baseline patient characteristics, treatment efficacy, factors affecting sustained virologic response at 12 weeks (SVR 12) after treatment, and adverse reactions were compared between the groups. A total of 327 patients were included in the study, of which 253 were HCV monoinfected, and 74 were HCV/HIV coinfected. There was a statistically significant difference observed in SVR 12 when comparing HCV monoinfection and HCV/HIV coinfection (94% and 84%, respectively, p=0.005). However, there were no significant factors identified as a predictor of a reduced response. The most common adverse effect was fatigue (27%). No significant drug interaction was observed between DAA and antiretroviral therapy. None of the patients discontinued the treatment due to adverse events. In a real-world setting, DAA regimens have lower SVR 12 in HCV/HIV coinfection than in HCV monoinfection. Further studies involving a higher number of HCV/HIV coinfected patients are needed to identify real predictors of a reduced response.

Generalized approach for identification and evaluation of technology-insertion options for military avionics systems

NASA Astrophysics Data System (ADS)

Harkness, Linda L.; Sjoberg, Eric S.

1996-06-01

The Georgia Tech Research Institute, sponsored by the Warner Robins Air Logistics Center, has developed an approach for efficiently postulating and evaluating methods for extending the life of radars and other avionics systems. The technique identified specific assemblies for potential replacement and evaluates the system level impact, including performance, reliability and life-cycle cost of each action. The initial impetus for this research was the increasing obsolescence of integrated circuits contained in the AN/APG-63 system. The operational life of military electronics is typically in excess of twenty years, which encompasses several generations of IC technology. GTRI has developed a systems approach to inserting modern technology components into older systems based upon identification of those functions which limit the system's performance or reliability and which are cost drivers. The presentation will discuss the above methodology and a technique for evaluating and ranking the different potential system upgrade options.

RATANA MEEKHAM, AN ELECTRICAL INTEGRATION TECHNICIAN FOR QUALIS CORP. OF HUNTSVILLE, ALABAMA, HELPS TEST AVIONICS -- COMPLEX VEHICLE SYSTEMS ENABLING NAVIGATION, COMMUNICATIONS AND OTHER FUNCTIONS CRITICAL TO HUMAN SPACEFLIGHT

NASA Image and Video Library

2015-01-08

RATANA MEEKHAM, AN ELECTRICAL INTEGRATION TECHNICIAN FOR QUALIS CORP. OF HUNTSVILLE, ALABAMA, HELPS TEST AVIONICS -- COMPLEX VEHICLE SYSTEMS ENABLING NAVIGATION, COMMUNICATIONS AND OTHER FUNCTIONS CRITICAL TO HUMAN SPACEFLIGHT -- FOR THE SPACE LAUNCH SYSTEM PROGRAM AT NASA’S MARSHALL SPACE FLIGHT CENTER IN HUNTSVILLE, ALABAMA. HER WORK SUPPORTS THE NASA ENGINEERING & SCIENCE SERVICES AND SKILLS AUGMENTATION CONTRACT LED BY JACOBS ENGINEERING OF HUNTSVILLE. MEEKHAM WORKS FULL-TIME AT MARSHALL WHILE FINISHING HER ASSOCIATE'S DEGREE IN MACHINE TOOL TECHNOLOGY AT CALHOUN COMMUNITY COLLEGE IN DECATUR, ALABAMA. THE SPACE LAUNCH SYSTEM, NASA’S NEXT HEAVY-LIFT LAUNCH VEHICLE, IS THE WORLD’S MOST POWERFUL ROCKET, SET TO FLY ITS FIRST UNCREWED LUNAR ORBITAL MISSION IN 2018. ITS FIRST.

Space Shuttle Program Primary Avionics Software System (PASS) Success Legacy - Major Accomplishments and Lessons Learned Detail Historical Timeline Analysis

NASA Technical Reports Server (NTRS)

Orr, James K.

2010-01-01

This presentation focuses on the Space Shuttle Primary Avionics Software System (PASS) and the people who developed and maintained this system. One theme is to provide quantitative data on software quality and reliability over a 30 year period. Consistent data relates to code break discrepancies. Requirements were supplied from external sources. Requirement inspections and measurements not implemented until later, beginning in 1985. Second theme is to focus on the people and organization of PASS. Many individuals have supported the PASS project over the entire period while transitioning from company to company and contract to contract. Major events and transitions have impacted morale (both positively and negatively) across the life of the project.

Next-generation avionics packaging and cooling 'test results from a prototype system'

NASA Astrophysics Data System (ADS)

Seals, J. D.

The author reports on the design, material characteristics, and test results obtained under the US Air Force's advanced aircraft avionics packaging technologies (AAAPT) program, whose charter is to investigate new designs and technologies for reliable packaging, interconnection, and thermal management. Under this program, AT&T Bell Laboratories has completed the preliminary testing of and is evaluating a number of promising materials and technologies, including conformal encapsulation, liquid flow-through cooling, and a cyanate ester backplane. A fifty-two module system incorporating these and and other technologies has undergone preliminary cooling efficiency, shock, sine and random vibration, and maintenance testing. One of the primary objectives was to evaluate the interaction compatibility of new materials and designs with other components in the system.

A fault-tolerant avionics suite for an entry research vehicle

NASA Technical Reports Server (NTRS)

Dzwonczyk, Mark; Stone, Howard

1988-01-01

A highly-reliable avionics suite has been designed for an Entry Research Vehicle. The autonomous spacecraft would be deployed from the Space Shuttle Orbiter and perform a variety of aerodynamic and propulsive maneuvers which may be required for future space transportation system vehicles. The flight electronics consist of a central fault-tolerant processor, which is resilient to all first failures, reliably cross-strapped to redundant and distributed sets of sensors and effectors. This paper describes the preliminary design and analysis of the architecture which resulted from a fifteen month study by the Charles Stark Draper Laboratory for the NASA Langley Research Center. After a brief introduction to the design task, the architecture of the central flight computer and its interface to the vehicle are discussed. Following this, the method and results of the baseline reliability study for the avionic suite are presented.

A fault-tolerant avionics suite for an entry research vehicle

NASA Astrophysics Data System (ADS)

Dzwonczyk, Mark; Stone, Howard

A highly-reliable avionics suite has been designed for an Entry Research Vehicle. The autonomous spacecraft would be deployed from the Space Shuttle Orbiter and perform a variety of aerodynamic and propulsive maneuvers which may be required for future space transportation system vehicles. The flight electronics consist of a central fault-tolerant processor, which is resilient to all first failures, reliably cross-strapped to redundant and distributed sets of sensors and effectors. This paper describes the preliminary design and analysis of the architecture which resulted from a fifteen month study by the Charles Stark Draper Laboratory for the NASA Langley Research Center. After a brief introduction to the design task, the architecture of the central flight computer and its interface to the vehicle are discussed. Following this, the method and results of the baseline reliability study for the avionic suite are presented.

Avionic technology testing by using a cognitive neurometric index: A study with professional helicopter pilots.

PubMed

Borghini, Gianluca; Aricò, Pietro; Di Flumeri, Gianluca; Salinari, Serenella; Colosimo, Alfredo; Bonelli, Stefano; Napoletano, Linda; Ferreira, Ana; Babiloni, Fabio

2015-01-01

In this study, we investigated the possibility to evaluate the impact of different avionic technologies on the mental workload of helicopter's pilots by measuring their brain activity with the EEG during a series of simulated missions carried out at AgustaWestland facilities in Yeovil (UK). The tested avionic technologies were: i) Head-Up Display (HUD); ii) Head-Mounted Display (HMD); iii) Full Conformal symbology (FC); iv) Flight Guidance (FG) symbology; v) Synthetic Vision System (SVS); and vi) Radar Obstacles (RO) detection system. It has been already demonstrated that in cognitive tasks, when the cerebral workload increases the EEG power spectral density (PSD) in theta band over frontal areas increases, and the EEG PSD in alpha band decreases over parietal areas. A mental workload index (MWL) has been here defined as the ratio between the frontal theta and parietal alpha EEG PSD values. Such index has been used for testing and comparing the different avionic technologies. Results suggested that the HUD provided a significant (p<;.05) workload reduction across all the flight scenarios with respect to the other technologies. In addition, the simultaneous use of FC and FG technologies (FC+FG) produced a significant decrement of the workload (p<;.01) with respect to the use of only the FC. Moreover, the use of the SVS technology provided on Head Down Display (HDD) with the simultaneous use of FC+FG and the RO seemed to produce a lower cerebral workload when compared with the use of only the FC. Interestingly, the workload estimation by means of subjective measures, provided by pilots through a NASA-TLX questionnaire, did not provide any significant differences among the different flight scenarios. These results suggested that the proposed MWL cognitive neurometrics could be used as a reliable measure of the user's mental workload, being a valid indicator for the comparison and the test of different avionic technologies.

Hepatitis C Virus in Kidney Transplant Recipients: A Problem on the Path to Eradication.

PubMed

Suarez Benjumea, A; Gonzalez-Corvillo, C; Sousa, J M; Bernal Blanco, G; Suñer Poblet, M; Perez Valdivia, M A; Gonzalez Roncero, F M; Acevedo, P; Gentil Govantez, M A

2016-11-01

Hepatitis C virus (HCV) still has significant prevalence in kidney transplant (KT) recipients and is related to poor recipient and graft survival. New direct-acting antivirals (DAA) are leading to a radical change in the problem. We studied HCV prevalence at the time of transplantation and in follow-up patients, the way cases are handled, and the results of DAA. A total of 2,001 KT had been performed in our center since 1978. Pre- or post-transplantation HCV serology was present in 1,880 cases and was positive in 13.4%. A total of 1,195 transplant recipients were still being monitored by us, with only 60 (5%) HCV+ and 45 (3.6%) RNA+ cases. Of these 45 HCV+/RNA+, 25 had been or were being treated, 7 were about to begin treatment, 1 was awaiting new DAA treatment owing to low glomerular filtration rate (GFR), 3 were being evaluated, 2 had been excluded owing to high comorbidity, 2 refused to be treated, 2 needed to return to hemodialysis, and 1 was lost to follow-up. Except 1 case where Viekira Pak was used because of low GFR, all cases included sofosbuvir as the main drug associated with either ledipasvir (70%) or daclatasvir (25%). Ribavirin was added as coadjuvant in 35% of cases. Twenty-one patients had completed treatment (84%). Two patients had to interrupt DAA therapy (8%), one because of hepatotoxicity and the other as a result of a liver transplantation. In every case, the graft maintained function and negativization of viral replication occurred. Side effects have been low, anemia related to ribavirin being the main one. Just one case needed to be interrupted at the 7th week of DAA therapy due to hepatotoxicity. It has frequently been necessary to adjust immunosuppression treatment with the use of higher doses of tacrolimus. Copyright © 2016 Elsevier Inc. All rights reserved.

Efficacy and Safety of Direct Acting Antivirals in Kidney Transplant Recipients with Chronic Hepatitis C Virus Infection.

PubMed

Lin, Ming V; Sise, Meghan E; Pavlakis, Martha; Amundsen, Beth M; Chute, Donald; Rutherford, Anna E; Chung, Raymond T; Curry, Michael P; Hanifi, Jasmine M; Gabardi, Steve; Chandraker, Anil; Heher, Eliot C; Elias, Nahel; Riella, Leonardo V

2016-01-01

The prevalence of Hepatitis C Virus (HCV) infection is significantly higher in patients with end-stage renal disease compared to the general population and poses important clinical challenges in patients who undergo kidney transplantation. Historically, interferon-based treatment options have been limited by low rates of efficacy and significant side effects, including risk of precipitating rejection. Limited data exist on the use of all-oral, interferon-free direct-acting antiviral (DAA) therapies in kidney transplant recipients. In this study, we performed a retrospective chart review with prospective clinical follow-up of post-kidney transplant patients treated with DAA therapies at three major hospitals in Boston, MA. A total of 24 kidney recipients with HCV infection received all-oral DAA therapy post-transplant. Patients were predominantly male (79%) with a median age of 60 years (range 34-70 years), median creatinine of 1.2 mg/dL (0.66-1.76), and 42% had advanced fibrosis or cirrhosis. The majority had HCV genotype 1a infection (58%). All patients received full-dose sofosbuvir; it was paired with simeprevir (9 patients without and 3 patients with ribavirin), ledipasvir (7 patients without and 1 patient with ribavirin) or ribavirin alone (4 patients). The overall sustained virologic response (SVR12) was 91% (21 out of 23 patients). One patient achieved SVR4 but demised prior to SVR12 check point due to treatment unrelated cause. Two treatment failures were successfully retreated with alternative DAA regimens and achieved SVR. Both initials failures occurred in patients with advanced fibrosis or cirrhosis, with genotype 1a infection, and prior HCV treatment failure. Adverse events were reported in 11 patients (46%) and were managed clinically without discontinuation of therapy. Calcineurin inhibitor trough levels did not significantly change during therapy. In this multi-center series of patients, all-oral DAA therapy appears to be safe and effective in post-kidney transplant patients with chronic HCV infection.

Efficacy and Safety of Direct Acting Antivirals in Kidney Transplant Recipients with Chronic Hepatitis C Virus Infection

PubMed Central

Lin, Ming V.; Sise, Meghan E.; Pavlakis, Martha; Amundsen, Beth M.; Chute, Donald; Rutherford, Anna E.; Chung, Raymond T.; Curry, Michael P.; Hanifi, Jasmine M.; Gabardi, Steve; Chandraker, Anil; Heher, Eliot C.; Elias, Nahel; Riella, Leonardo V.

2016-01-01

The prevalence of Hepatitis C Virus (HCV) infection is significantly higher in patients with end-stage renal disease compared to the general population and poses important clinical challenges in patients who undergo kidney transplantation. Historically, interferon-based treatment options have been limited by low rates of efficacy and significant side effects, including risk of precipitating rejection. Limited data exist on the use of all-oral, interferon-free direct-acting antiviral (DAA) therapies in kidney transplant recipients. In this study, we performed a retrospective chart review with prospective clinical follow-up of post-kidney transplant patients treated with DAA therapies at three major hospitals in Boston, MA. A total of 24 kidney recipients with HCV infection received all-oral DAA therapy post-transplant. Patients were predominantly male (79%) with a median age of 60 years (range 34–70 years), median creatinine of 1.2 mg/dL (0.66–1.76), and 42% had advanced fibrosis or cirrhosis. The majority had HCV genotype 1a infection (58%). All patients received full-dose sofosbuvir; it was paired with simeprevir (9 patients without and 3 patients with ribavirin), ledipasvir (7 patients without and 1 patient with ribavirin) or ribavirin alone (4 patients). The overall sustained virologic response (SVR12) was 91% (21 out of 23 patients). One patient achieved SVR4 but demised prior to SVR12 check point due to treatment unrelated cause. Two treatment failures were successfully retreated with alternative DAA regimens and achieved SVR. Both initials failures occurred in patients with advanced fibrosis or cirrhosis, with genotype 1a infection, and prior HCV treatment failure. Adverse events were reported in 11 patients (46%) and were managed clinically without discontinuation of therapy. Calcineurin inhibitor trough levels did not significantly change during therapy. In this multi-center series of patients, all-oral DAA therapy appears to be safe and effective in post-kidney transplant patients with chronic HCV infection. PMID:27415632

Antiviral therapy of hepatitis C in 2014: do we need resistance testing?

PubMed

Schneider, Maximilian David; Sarrazin, Christoph

2014-05-01

The treatment of chronic hepatitis C has fundamentally changed since the approval of the first direct-acting antivirals (DAA) in 2011. In addition to telaprevir and boceprevir, in 2014 two new NS3 protease inhibitors (simeprevir and faldaprevir), one non-nucleoside polymerase inhibitor (sofosbuvir) and one NS5a replication complex inhibitor (daclatasvir) have expanded the treatment options for chronic hepatitis C. Resistance-associated variants (RAV) are naturally produced during the HCV life cycle. The frequency of RAVs within HCV quasispecies mainly depends on their replicational fitness. Variants conferring resistance to nucleos(t)ide analogues have not been detected, and the majority of NS3 protease-resistant variants are present at low frequencies (0.1-3%) before initiation of DAA-based therapies. However, the Q80K variant conferring resistance to simeprevir has been observed in 9-48% of untreated HCV genotype 1a-infected patients, leading to reduced SVR rates. Resistant variants are detectable in the majority of patients with treatment failure to NS3 protease inhibitor- or NS5a inhibitor-based antiviral therapy. Long-term follow-up studies by population-based sequence analysis have shown the disappearance of resistant variants in the majority of patients, with median times to loss of mutations of 4-64weeks. For the nucleotide analogue sofosbuvir, the emergence of the S282T resistant variant has been observed only in single patients, with reversion to wild-type within several weeks. Data are sparse on retreatment of patients with the same DAA or the same class of DAAs. However, retreatment with a different class of DAAs after failure of NS3 protease inhibitor-based therapy has been successful in small studies. This article forms part of a symposium in Antiviral Research on "Hepatitis C: next steps toward global eradication." Copyright © 2014 Elsevier B.V. All rights reserved.

A translational study of resistance emergence using sequential direct-acting antiviral agents for hepatitis C using ultra-deep sequencing.

PubMed

Abe, Hiromi; Hayes, C Nelson; Hiraga, Nobuhiko; Imamura, Michio; Tsuge, Masataka; Miki, Daiki; Takahashi, Shoichi; Ochi, Hidenori; Chayama, Kazuaki

2013-09-01

Direct-acting antiviral agents (DAAs) against hepatitis C virus (HCV) have recently been developed and are ultimately hoped to replace interferon-based therapy. However, DAA monotherapy results in rapid emergence of resistant strains and DAAs must be used in combinations that present a high genetic barrier to resistance, although viral kinetics of multidrug-resistant strains remain poorly characterized. The aim of this study is to track the emergence and fitness of resistance using combinations of telaprevir and NS5A or NS5B inhibitors with genotype 1b clones. HCV-infected chimeric mice were treated with DAAs, and resistance was monitored using direct and ultra-deep sequencing. Combination therapy with telaprevir and BMS-788329 (NS5A inhibitor) reduced serum HCV RNA to undetectable levels. The presence of an NS3-V36A telaprevir resistance mutation resulted in poor response to telaprevir monotherapy but showed significant HCV reduction when telaprevir was combined with BMS-788329. However, a BMS-788329-resistant strain emerged at low frequency. Infection with a BMS-788329-resistant NS5A-L31V mutation rapidly resulted in gain of an additional NS5A-Y93A mutation that conferred telaprevir resistance during combination therapy. Infection with dual NS5AL31V/NS5AY93H mutations resulted in poor response to combination therapy and development of telaprevir resistance. Although HCV RNA became undetectable soon after the beginning of combination therapy with BMS-788329 and BMS-821095 (NS5B inhibitor), rebound with emergence of resistance against all three drugs occurred. Triple resistance also occurred following infection with the NS3V36A/NS5AL31V/NS5AY93H triple mutation. Resistant strains easily develop from cloned virus strains. Sequential use of DAAs should be avoided to prevent emergence of multidrug-resistant strains.

General Aviation Avionics Statistics : 1976

DOT National Transportation Integrated Search

1979-11-01

This report presents avionics statistics for the 1976 general aviation (GA) aircraft fleet and is the third in a series titled "General Aviation Avionics Statistics." The statistics are presented in a capability group framework which enables one to r...

General aviation avionics statistics : 1977.

DOT National Transportation Integrated Search

1980-06-01

This report presents avionics statistics for the 1977 general aviation (GA) aircraft fleet and is the fourth in a series. The statistics are presented in a capability group framework which enables one to relate airborne avionics equipment to the capa...

General Aviation Avionics Statistics : 1979 Data

DOT National Transportation Integrated Search

1981-04-01

This report presents avionics statistics for the 1979 general aviation (GA) aircraft fleet and is the sixth in a series titled General Aviation Avionics Statistics. The statistics preseneted in a capability group framework which enables one to relate...

Devising Mobile Sensing and Actuation Infrastructure with Drones.

PubMed

Bae, Mungyu; Yoo, Seungho; Jung, Jongtack; Park, Seongjoon; Kim, Kangho; Kim, Joon Yeop Lee; Kim, Hwangnam

2018-02-19

Vast applications and services have been enabled as the number of mobile or sensing devices with communication capabilities has grown. However, managing the devices, integrating networks or combining services across different networks has become a new problem since each network is not directly connected via back-end core networks or servers. The issue is and has been discussed especially in wireless sensor and actuator networks (WSAN). In such systems, sensors and actuators are tightly coupled, so when an independent WSAN needs to collaborate with other networks, it is difficult to adequately combine them into an integrated infrastructure. In this paper, we propose drone-as-a-gateway (DaaG), which uses drones as mobile gateways to interconnect isolated networks or combine independent services. Our system contains features that focus on the service being provided in the order of importance, different from an adaptive simple mobile sink system or delay-tolerant system. Our simulation results have shown that the proposed system is able to activate actuators in the order of importance of the service, which uses separate sensors' data, and it consumes almost the same time in comparison with other path-planning algorithms. Moreover, we have implemented DaaG and presented results in a field test to show that it can enable large-scale on-demand deployment of sensing and actuation infrastructure or the Internet of Things (IoT).

Devising Mobile Sensing and Actuation Infrastructure with Drones

PubMed Central

Jung, Jongtack; Park, Seongjoon; Kim, Kangho; Lee, Joon Yeop

2018-01-01

Vast applications and services have been enabled as the number of mobile or sensing devices with communication capabilities has grown. However, managing the devices, integrating networks or combining services across different networks has become a new problem since each network is not directly connected via back-end core networks or servers. The issue is and has been discussed especially in wireless sensor and actuator networks (WSAN). In such systems, sensors and actuators are tightly coupled, so when an independent WSAN needs to collaborate with other networks, it is difficult to adequately combine them into an integrated infrastructure. In this paper, we propose drone-as-a-gateway (DaaG), which uses drones as mobile gateways to interconnect isolated networks or combine independent services. Our system contains features that focus on the service being provided in the order of importance, different from an adaptive simple mobile sink system or delay-tolerant system. Our simulation results have shown that the proposed system is able to activate actuators in the order of importance of the service, which uses separate sensors’ data, and it consumes almost the same time in comparison with other path-planning algorithms. Moreover, we have implemented DaaG and presented results in a field test to show that it can enable large-scale on-demand deployment of sensing and actuation infrastructure or the Internet of Things (IoT). PMID:29463064

Outlook at the Future of the Airline Avionics Industry

DOT National Transportation Integrated Search

1998-01-01

The aviation industry is slowly but surely changing its character. As airlines restructure, what they ask of, and how they relate to their suppliers (including avionics manufacturers) will greatly change as well. The avionics industry is currently fa...

Micro-Scale Avionics Thermal Management

NASA Technical Reports Server (NTRS)

Moran, Matthew E.

2001-01-01

Trends in the thermal management of avionics and commercial ground-based microelectronics are converging, and facing the same dilemma: a shortfall in technology to meet near-term maximum junction temperature and package power projections. Micro-scale devices hold the key to significant advances in thermal management, particularly micro-refrigerators/coolers that can drive cooling temperatures below ambient. A microelectromechanical system (MEMS) Stirling cooler is currently under development at the NASA Glenn Research Center to meet this challenge with predicted efficiencies that are an order of magnitude better than current and future thermoelectric coolers.

Research in Functionally Distributed Computer Systems Development. Volume III. Evaluation of Conversion to a Back-End Data Base Management System.

DTIC Science & Technology

1976-03-01

RESEARCH IN FUNCTIONALLY DISTRIBUTED COMPUTER SYSTEMS DEVEI.OPME--ETClU) MAR 76 P S FISHER, F MARYANSKI DAA629-76-6-0108 UNCLASSIFIED CS-76-08AN...RESEARCH IN FUNCTIONALLY !DISTRIBUTED COMPUTER SYSTEMS DEVELOPMENT Kansas State University Virgil Wallentine Principal Investigator Approved for public...reme; disiribution unlimited DTIC \\4JWE III ELECTi"U ~E V0AI. Ill ~1ONTAUG 2 0 1981&EV .IAIN LiSP4 F U.S. ARMY COMPUTER SYSTEMS COMMAND FT BELVOIR, VA