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Sample records for acp multiprocessor system

  1. The ACP (Advanced Computer Program) Branch bus and real-time applications of the ACP multiprocessor system

    SciTech Connect

    Hance, R.; Areti, H.; Atac, R.; Biel, J.; Cook, A.; Fischler, M.; Gaines, I.; Husby, D.; Nash, T.; Zmuda, T.

    1987-05-08

    The ACP Branchbus, a high speed differential bus for data movement in multiprocessing and data acquisition environments, is described. This bus was designed as the central bus in the ACP multiprocessing system. In its full implementation with 16 branches and a bus switch, it will handle data rates of 160 MByte/sec and allow reliable data transmission over inter rack distances. We also summarize applications of the ACP system in experimental data acquisition, triggering and monitoring, with special attention paid to FASTBUS environments.

  2. Reproducibility in a multiprocessor system

    DOEpatents

    Bellofatto, Ralph A; Chen, Dong; Coteus, Paul W; Eisley, Noel A; Gara, Alan; Gooding, Thomas M; Haring, Rudolf A; Heidelberger, Philip; Kopcsay, Gerard V; Liebsch, Thomas A; Ohmacht, Martin; Reed, Don D; Senger, Robert M; Steinmacher-Burow, Burkhard; Sugawara, Yutaka

    2013-11-26

    Fixing a problem is usually greatly aided if the problem is reproducible. To ensure reproducibility of a multiprocessor system, the following aspects are proposed; a deterministic system start state, a single system clock, phase alignment of clocks in the system, system-wide synchronization events, reproducible execution of system components, deterministic chip interfaces, zero-impact communication with the system, precise stop of the system and a scan of the system state.

  3. A multiprocessor operating system simulator

    SciTech Connect

    Johnston, G.M.; Campbell, R.H. . Dept. of Computer Science)

    1988-01-01

    This paper describes a multiprocessor operating system simulator that was developed by the authors in the Fall of 1987. The simulator was built in response to the need to provide students with an environment in which to build and test operating system concepts as part of the coursework of a third-year undergraduate operating systems course. Written in C++, the simulator uses the co-routine style task package that is distributed with the AT and T C++ Translator to provide a hierarchy of classes that represents a broad range of operating system software and hardware components. The class hierarchy closely follows that of the Choices family of operating systems for loosely and tightly coupled multiprocessors. During an operating system course, these classes are refined and specialized by students in homework assignments to facilitate experimentation with different aspects of operating system design and policy decisions. The current implementation runs on the IBM RT PC under 4.3bsd UNIX.

  4. A Multiprocessor Operating System Simulator

    NASA Technical Reports Server (NTRS)

    Johnston, Gary M.; Campbell, Roy H.

    1988-01-01

    This paper describes a multiprocessor operating system simulator that was developed by the authors in the Fall semester of 1987. The simulator was built in response to the need to provide students with an environment in which to build and test operating system concepts as part of the coursework of a third-year undergraduate operating systems course. Written in C++, the simulator uses the co-routine style task package that is distributed with the AT&T C++ Translator to provide a hierarchy of classes that represents a broad range of operating system software and hardware components. The class hierarchy closely follows that of the 'Choices' family of operating systems for loosely- and tightly-coupled multiprocessors. During an operating system course, these classes are refined and specialized by students in homework assignments to facilitate experimentation with different aspects of operating system design and policy decisions. The current implementation runs on the IBM RT PC under 4.3bsd UNIX.

  5. Shared performance monitor in a multiprocessor system

    DOEpatents

    Chiu, George; Gara, Alan G; Salapura, Valentina

    2014-12-02

    A performance monitoring unit (PMU) and method for monitoring performance of events occurring in a multiprocessor system. The multiprocessor system comprises a plurality of processor devices units, each processor device for generating signals representing occurrences of events in the processor device, and, a single shared counter resource for performance monitoring. The performance monitor unit is shared by all processor cores in the multiprocessor system. The PMU is further programmed to monitor event signals issued from non-processor devices.

  6. Spaceborne VHSIC multiprocessor system for AI applications

    NASA Technical Reports Server (NTRS)

    Lum, Henry, Jr.; Shrobe, Howard E.; Aspinall, John G.

    1988-01-01

    A multiprocessor system, under design for space-station applications, makes use of the latest generation symbolic processor and packaging technology. The result will be a compact, space-qualified system two to three orders of magnitude more powerful than present-day symbolic processing systems.

  7. Rollback Hardware For Time Warp Multiprocessor Systems

    NASA Technical Reports Server (NTRS)

    Robb, Michael J.; Buzzell, Calvin A.

    1996-01-01

    Rollback Chip (RBC) module is computer circuit board containing special-purpose memory circuits for use in multiprocessor computer system. Designed to help realize speedup potential of parallel processing for simulation of discrete events by use of Time Warp operating system.

  8. Visual Tutoring System for Programming Multiprocessor Networks.

    ERIC Educational Resources Information Center

    Trichina, Elena

    1996-01-01

    Describes a visual tutoring system for programming distributive-memory multiprocessor networks. Highlights include difficulties of parallel programming, and three instructional modes in the system, including a hypertext-like lecture, a question-answer mode, and an expert aid mode. (Author/LRW)

  9. Shared performance monitor in a multiprocessor system

    DOEpatents

    Chiu, George; Gara, Alan G.; Salapura, Valentina

    2012-07-24

    A performance monitoring unit (PMU) and method for monitoring performance of events occurring in a multiprocessor system. The multiprocessor system comprises a plurality of processor devices units, each processor device for generating signals representing occurrences of events in the processor device, and, a single shared counter resource for performance monitoring. The performance monitor unit is shared by all processor cores in the multiprocessor system. The PMU comprises: a plurality of performance counters each for counting signals representing occurrences of events from one or more the plurality of processor units in the multiprocessor system; and, a plurality of input devices for receiving the event signals from one or more processor devices of the plurality of processor units, the plurality of input devices programmable to select event signals for receipt by one or more of the plurality of performance counters for counting, wherein the PMU is shared between multiple processing units, or within a group of processors in the multiprocessing system. The PMU is further programmed to monitor event signals issued from non-processor devices.

  10. Distributed parallel messaging for multiprocessor systems

    DOEpatents

    Chen, Dong; Heidelberger, Philip; Salapura, Valentina; Senger, Robert M; Steinmacher-Burrow, Burhard; Sugawara, Yutaka

    2013-06-04

    A method and apparatus for distributed parallel messaging in a parallel computing system. The apparatus includes, at each node of a multiprocessor network, multiple injection messaging engine units and reception messaging engine units, each implementing a DMA engine and each supporting both multiple packet injection into and multiple reception from a network, in parallel. The reception side of the messaging unit (MU) includes a switch interface enabling writing of data of a packet received from the network to the memory system. The transmission side of the messaging unit, includes switch interface for reading from the memory system when injecting packets into the network.

  11. A multiprocessor airborne lidar data system

    NASA Astrophysics Data System (ADS)

    Wright, C. W.; Bailey, S. A.; Heath, G. E.; Piazza, C. R.

    A new multiprocessor data acquisition system was developed for the existing Airborne Oceanographic Lidar (AOL). This implementation simultaneously utilizes five single board 68010 microcomputers, the UNIX system V operating system, and the real time executive VRTX. The original data acquisition system was implemented on a Hewlett Packard HP 21-MX 16 bit minicomputer using a multi-tasking real time operating system and a mixture of assembly and FORTRAN languages. The present collection of data sources produce data at widely varied rates and require varied amounts of burdensome real time processing and formatting. It was decided to replace the aging HP 21-MX minicomputer with a multiprocessor system. A new and flexible recording format was devised and implemented to accommodate the constantly changing sensor configuration. A central feature of this data system is the minimization of non-remote sensing bus traffic. Therefore, it is highly desirable that each micro be capable of functioning as much as possible on-card or via private peripherals. The bus is used primarily for the transfer of remote sensing data to or from the buffer queue.

  12. A multiprocessor airborne lidar data system

    NASA Technical Reports Server (NTRS)

    Wright, C. W.; Bailey, S. A.; Heath, G. E.; Piazza, C. R.

    1988-01-01

    A new multiprocessor data acquisition system was developed for the existing Airborne Oceanographic Lidar (AOL). This implementation simultaneously utilizes five single board 68010 microcomputers, the UNIX system V operating system, and the real time executive VRTX. The original data acquisition system was implemented on a Hewlett Packard HP 21-MX 16 bit minicomputer using a multi-tasking real time operating system and a mixture of assembly and FORTRAN languages. The present collection of data sources produce data at widely varied rates and require varied amounts of burdensome real time processing and formatting. It was decided to replace the aging HP 21-MX minicomputer with a multiprocessor system. A new and flexible recording format was devised and implemented to accommodate the constantly changing sensor configuration. A central feature of this data system is the minimization of non-remote sensing bus traffic. Therefore, it is highly desirable that each micro be capable of functioning as much as possible on-card or via private peripherals. The bus is used primarily for the transfer of remote sensing data to or from the buffer queue.

  13. Partitioning of regular computation on multiprocessor systems

    NASA Technical Reports Server (NTRS)

    Lee, Fung Fung

    1988-01-01

    Problem partitioning of regular computation over two dimensional meshes on multiprocessor systems is examined. The regular computation model considered involves repetitive evaluation of values at each mesh point with local communication. The computational workload and the communication pattern are the same at each mesh point. The regular computation model arises in numerical solutions of partial differential equations and simulations of cellular automata. Given a communication pattern, a systematic way to generate a family of partitions is presented. The influence of various partitioning schemes on performance is compared on the basis of computation to communication ratio.

  14. Allocation for the SANDAC multiprocessor system

    SciTech Connect

    Ravl, T.M.; Ercegovac, M.D.

    1986-01-01

    This report describes an algorithm for the static allocation of tasks in a general Dataflow Multiprocessor and the SANDAC IV system in particular. Initially a model of execution and the underlying assumptions about the architecture are outlined. The authors then discuss a Graph Reduction algorithm for preprocessing the computation graph. The Graph Reduction algorithm reduces a fine grain graph to an optimal grain graph. The heuristic allocation algorithm is presented and is based on giving precedence to critical paths and minimizing the communication time between tasks. The performance of the algorithm is analyzed and the effect of varying parameters is studied. Subsequently an alternative variation with better characteristics is proposed.

  15. Spaceborne application multiprocessor operating system

    NASA Astrophysics Data System (ADS)

    Grisbeck, Gary S.; Webber, Wesley D.

    1992-03-01

    The Operational Kernel (OK) system for the Spaceborne Processor Array-1 (SPA-1) software development environment is described. The OK system demonstration featured fully autonomous onboard control of data movement, fault detection, fault isolation, hardware reconfiguration, application restart, and load balancing. Random nodal or processing hardware was caused to fail by selection of switches on a fault injection panel. The SPA-1 based on the OK written in Ada detected that a failure had occurred, isolated it, redistributed the processing load, and continued with the application processing.

  16. Use of a multiprocessor for control of a robotic system

    NASA Technical Reports Server (NTRS)

    Klein, C. A.; Wahawisan, W.

    1982-01-01

    In the case of complex industrial operations, the use of a multiprocessor for the control of a robotic system has a number of potential advantages over an employment of a single-processor design. In addition to the increased speed of parallel computation, multiprocessors can provide greater reliability. However, the control of a system with a multiprocessor is much more complicated, and requires resolution of a number of design criteria. The degree of coupling, the processor interconnection configuration, and the method of fault detection and correction are factors in the design of a multiprocessor which need to be considered for each particular application. In connection with the present investigation, a five-unit multiprocessor was built to experiment with the multiprocessor control of a robotic system. While the primary application of the multiprocessor involves the control of the Ohio State University (OSU) Hexapod, an 18-degree-of-freedom, motor-driven walking machine, the multiprocessor was designed to be versatile enough for a numbr of other uses.

  17. Fault diagnosis in sparse multiprocessor systems

    NASA Technical Reports Server (NTRS)

    Blough, Douglas M.; Sullivan, Gregory F.; Masson, Gerald M.

    1988-01-01

    The problem of fault diagnosis in multiprocessor systems is considered under a uniformly probabilistic model in which processors are faulty with probability p. This work focuses on minimizing the number of tests that must be conducted in order to correctly diagnose the state of every processor in the system with high probability. A diagnosis algorithm that can correctly diagnose the state of every processor with probability approaching one in a class of systems performing slightly greater than a linear number of tests is presented. A nearly matching lower bound on the number of tests required to achieve correct diagnosis in arbitrary systems is also proven. The number of tests required under this probabilistic model is shown to be significantly less than under a bounded-size fault set model. Because the number of tests that must be conducted is a measure of the diagnosis overhead, these results represent a dramatic improvement in the performance of system-level diagnosis technique.

  18. Preliminary basic performance analysis of the Cedar multiprocessor memory system

    NASA Technical Reports Server (NTRS)

    Gallivan, K.; Jalby, W.; Turner, S.; Veidenbaum, A.; Wijshoff, H.

    1991-01-01

    Some preliminary basic results on the performance of the Cedar multiprocessor memory system are presented. Empirical results are presented and used to calibrate a memory system simulator which is then used to discuss the scalability of the system.

  19. Clocking and synchronization circuits in multiprocessor systems

    SciTech Connect

    Jeong, D.K.

    1989-01-01

    Microprocessors based on RISC (Reduced Instruction Set Computer) concepts have demonstrated an ability to provide more computing power at a given level of integration than conventional microprocessors. The next step is multiprocessors composed of RISC processing elements. Communication bandwidth among such microprocessors is critical in achieving efficient hardware utilization. This thesis focuses on the communication capability of VLSI circuits and presents new circuit techniques as a guide to build an interconnection network of VLSI microprocessors. Circuit techniques for PLL-based clock generation are described along with stability criteria. The main objective of the circuit is to realize a zero delay buffer. Experimental results show the feasibility of such circuits in VLSI. Synchronizer circuit configurations in both bipolar and MOS technology that best utilize each device, or overcome the technology limit using a bandwidth doubling technique are shown. Interface techniques including handshake mechanisms in such a system are also described.

  20. File-System Workload on a Scientific Multiprocessor

    NASA Technical Reports Server (NTRS)

    Kotz, David; Nieuwejaar, Nils

    1995-01-01

    Many scientific applications have intense computational and I/O requirements. Although multiprocessors have permitted astounding increases in computational performance, the formidable I/O needs of these applications cannot be met by current multiprocessors a their I/O subsystems. To prevent I/O subsystems from forever bottlenecking multiprocessors and limiting the range of feasible applications, new I/O subsystems must be designed. The successful design of computer systems (both hardware and software) depends on a thorough understanding of their intended use. A system designer optimizes the policies and mechanisms for the cases expected to most common in the user's workload. In the case of multiprocessor file systems, however, designers have been forced to build file systems based only on speculation about how they would be used, extrapolating from file-system characterizations of general-purpose workloads on uniprocessor and distributed systems or scientific workloads on vector supercomputers (see sidebar on related work). To help these system designers, in June 1993 we began the Charisma Project, so named because the project sought to characterize 1/0 in scientific multiprocessor applications from a variety of production parallel computing platforms and sites. The Charisma project is unique in recording individual read and write requests-in live, multiprogramming, parallel workloads (rather than from selected or nonparallel applications). In this article, we present the first results from the project: a characterization of the file-system workload an iPSC/860 multiprocessor running production, parallel scientific applications at NASA's Ames Research Center.

  1. VME rollback hardware for time warp multiprocessor systems

    NASA Technical Reports Server (NTRS)

    Robb, Michael J.; Buzzell, Calvin A.

    1992-01-01

    The purpose of the research effort is to develop and demonstrate innovative hardware to implement specific rollback and timing functions required for efficient queue management and precision timekeeping in multiprocessor discrete event simulations. The previously completed phase 1 effort demonstrated the technical feasibility of building hardware modules which eliminate the state saving overhead of the Time Warp paradigm used in distributed simulations on multiprocessor systems. The current phase 2 effort will build multiple pre-production rollback hardware modules integrated with a network of Sun workstations, and the integrated system will be tested by executing a Time Warp simulation. The rollback hardware will be designed to interface with the greatest number of multiprocessor systems possible. The authors believe that the rollback hardware will provide for significant speedup of large scale discrete event simulation problems and allow multiprocessors using Time Warp to dramatically increase performance.

  2. Interrupt handling in a multiprocessor computing system

    SciTech Connect

    D'Amico, L.W.; Guyer, J.M.

    1989-01-03

    A multiprocessor computing system is described comprising: a system bus, including an address bus for carrying an address phase of an instruction and a data bus for carrying a data phase of an instruction; a plurality of processing units connected to the system bus, each processing unit including means for generating broadcast interrupt origin request instructions on the system bus; asynchronous input/output channel controllers connected to the system bus, each of the input/output channel controllers including means for generating a synchronizing signal in response to completion of an address phase of a broadcast instruction on the system bus, and corresponding to a different one of the processing units connected through each of the input/output channel controllers, the input/output channel controllers being arranged on the priority lines in order of priority, the priority lines being gated in an input/output channel controller so that priority is asserted over all lower priority input/output channel controllers on a priority line by an input/output channel controller if the input/output channel controller has an interrupt pending in the input/output channel controller for the processing unit corresponding to the priority line.

  3. Prefetching in file systems for MIMD multiprocessors

    NASA Technical Reports Server (NTRS)

    Kotz, David F.; Ellis, Carla Schlatter

    1990-01-01

    The question of whether prefetching blocks on the file into the block cache can effectively reduce overall execution time of a parallel computation, even under favorable assumptions, is considered. Experiments have been conducted with an interleaved file system testbed on the Butterfly Plus multiprocessor. Results of these experiments suggest that (1) the hit ratio, the accepted measure in traditional caching studies, may not be an adequate measure of performance when the workload consists of parallel computations and parallel file access patterns, (2) caching with prefetching can significantly improve the hit ratio and the average time to perform an I/O (input/output) operation, and (3) an improvement in overall execution time has been observed in most cases. In spite of these gains, prefetching sometimes results in increased execution times (a negative result, given the optimistic nature of the study). The authors explore why it is not trivial to translate savings on individual I/O requests into consistently better overall performance and identify the key problems that need to be addressed in order to improve the potential of prefetching techniques in the environment.

  4. Clocking and synchronization circuits in multiprocessor systems

    SciTech Connect

    Jeong, Deog-Kyoon.

    1989-01-01

    Microprocessors based on RISC (Reduced Instruction Set Computer) concepts have demonstrated an ability to provide more computing power at a given level of integration than conventional microprocessors. The next step is multiprocessors composed of RISC processing elements. Communication bandwidth among such microprocessors is critical in achieving efficient hardware utilization. This thesis focuses on the communication capability of VLSI circuits and presents new circuit techniques as a guide to build an interconnection network of VLSI microprocessors. Two of the most prominent problems in a synchronous system, which most of the current computer systems are based on, have been clock skew and synchronization failure. A new concept called self-timed systems solves such problems but has not been accepted in microprocessor implementations yet because of its complex design procedure and increased overhead. With this in mind, this thesis concentrates on a system in which individual synchronous subsystems are connected asynchronously. Synchronous subsystems operate with a better control over clock skew using a phase locked loop (PLL) technique. Communication among subsystems is done asynchronously with a controlled synchronization failure rate. One advantage is that conventional VLSI design methodologies which are more efficient can still be applied. Circuit techniques for PLL-based clock generation are described along with stability criteria. The main objective of the circuit is to realize a zero delay buffer. Experimental results show the feasibility of such circuits in VLSI. Synchronizer circuit configurations in both bipolar and MOS technology that best utilize each device, or overcome the technology limit using a bandwidth doubling technique are shown. Interface techniques including handshake mechanisms in such a system are also described.

  5. VME multiprocessor system for data acquisition at OSIRIS

    SciTech Connect

    Ziem, P.; Kiehne, T.; Beschorner, C.; Drescher, B.; Zahn, J.

    1987-08-01

    A VME multiprocessor system for data acquisition and data display utilizing several MC68XXX based CPUs and VMEbuses is described. The design of the VME system was stimulated by the data handling requirements of experiments using the anti-Compton spectrometer OSIRIS, i.e. data storage on optical disks and on-line accumulation of large 2-dimensional histograms (4096 x 4096 channels). Due to the general approach the VME system is easily applicable for other nuclear physics experiments.

  6. C-MOS array design techniques: SUMC multiprocessor system study

    NASA Technical Reports Server (NTRS)

    Clapp, W. A.; Helbig, W. A.; Merriam, A. S.

    1972-01-01

    The current capabilities of LSI techniques for speed and reliability, plus the possibilities of assembling large configurations of LSI logic and storage elements, have demanded the study of multiprocessors and multiprocessing techniques, problems, and potentialities. Evaluated are three previous systems studies for a space ultrareliable modular computer multiprocessing system, and a new multiprocessing system is proposed that is flexibly configured with up to four central processors, four 1/0 processors, and 16 main memory units, plus auxiliary memory and peripheral devices. This multiprocessor system features a multilevel interrupt, qualified S/360 compatibility for ground-based generation of programs, virtual memory management of a storage hierarchy through 1/0 processors, and multiport access to multiple and shared memory units.

  7. An Or Processing Multiprocessor System For Artificial Intelligence

    NASA Astrophysics Data System (ADS)

    Fu, Hsin-Chia; Chiang, Cheng-Chin

    1989-03-01

    In this paper, an OR-Parallel Execution model based multiprocessor system is proposed. Our OR-parallel execution model addresses the following features: (1) Run-time Intelligent Backtracking, (2) Distributed process control and execution, (3) Minimization of data communication between processors, and (4) Minimization of parallel processing management overhead. Special hardware modules such as Intelligent Backtracking Controller, and Forward Execution Controller are designed to further enhance these features in run-time. A bus connected multiprocessor system is designed to experience the proposed OR-parallel execution model. Recent simulation results indicate that the OR-parallel execution model can be successfully used to conduct the parallel processing of most non-deterministic Prolog applications such as database systems, rule-based expert systems, natural language processing and theorem proving, etc.

  8. Rollback-recovery techniques and architectural support for multiprocessor systems

    SciTech Connect

    Chiang Chungyang.

    1991-01-01

    The author proposes efficient and robust fault diagnosis and rollback-recovery techniques to enhance system availability as well as performance in both distributed-memory and shared-bus shared-memory multiprocessor systems. Architectural support for the proposed rollback-recovery technique in a bus-based shared-memory multiprocessor system is also investigated to adaptively fine tune the proposed rollback-recovery technique in this type of system. A comparison of the performance of the proposed techniques with other existing techniques is made, a topic on which little quantitative information is available in the literature. New diagnosis concepts are introduced to show that the author's diagnosis technique yields higher diagnosis coverage and facilitates the performance evaluation of various fault-diagnosis techniques.

  9. Multiprocessor system with multiple concurrent modes of execution

    SciTech Connect

    Ahn, Daniel; Ceze, Luis H; Chen, Dong; Gara, Alan; Heidelberger, Philip; Ohmacht, Martin

    2013-12-31

    A multiprocessor system supports multiple concurrent modes of speculative execution. Speculation identification numbers (IDs) are allocated to speculative threads from a pool of available numbers. The pool is divided into domains, with each domain being assigned to a mode of speculation. Modes of speculation include TM, TLS, and rollback. Allocation of the IDs is carried out with respect to a central state table and using hardware pointers. The IDs are used for writing different versions of speculative results in different ways of a set in a cache memory.

  10. Programmable partitioning for high-performance coherence domains in a multiprocessor system

    DOEpatents

    Blumrich, Matthias A.; Salapura, Valentina

    2011-01-25

    A multiprocessor computing system and a method of logically partitioning a multiprocessor computing system are disclosed. The multiprocessor computing system comprises a multitude of processing units, and a multitude of snoop units. Each of the processing units includes a local cache, and the snoop units are provided for supporting cache coherency in the multiprocessor system. Each of the snoop units is connected to a respective one of the processing units and to all of the other snoop units. The multiprocessor computing system further includes a partitioning system for using the snoop units to partition the multitude of processing units into a plurality of independent, memory-consistent, adjustable-size processing groups. Preferably, when the processor units are partitioned into these processing groups, the partitioning system also configures the snoop units to maintain cache coherency within each of said groups.

  11. Operating system for a real-time multiprocessor propulsion system simulator. User's manual

    NASA Technical Reports Server (NTRS)

    Cole, G. L.

    1985-01-01

    The NASA Lewis Research Center is developing and evaluating experimental hardware and software systems to help meet future needs for real-time, high-fidelity simulations of air-breathing propulsion systems. Specifically, the real-time multiprocessor simulator project focuses on the use of multiple microprocessors to achieve the required computing speed and accuracy at relatively low cost. Operating systems for such hardware configurations are generally not available. A real time multiprocessor operating system (RTMPOS) that supports a variety of multiprocessor configurations was developed at Lewis. With some modification, RTMPOS can also support various microprocessors. RTMPOS, by means of menus and prompts, provides the user with a versatile, user-friendly environment for interactively loading, running, and obtaining results from a multiprocessor-based simulator. The menu functions are described and an example simulation session is included to demonstrate the steps required to go from the simulation loading phase to the execution phase.

  12. Multiprocessor system for Holter tape analysis (ECG)

    SciTech Connect

    Feldman, C.L.; Hubelbank, M.; Valvo, V.; Lane, B.

    1983-01-01

    Although techniques for recording and analyzing longterm ambulatory ECGS have been in existence for more than 20 years, the clinical usefulness and frequency of application of the technique continue to grow at an extraordinary rate. To meet the need for faster, more efficient processing of Holter tapes and the growing requirement that the analysis of the tape be quantitatively accurate, a new Holter analysis system has been developed. This system is built around two LSI11 microprocessors and a special purpose byte processor which incorporates an AMD 2903 bit slice chip. It includes 30 MB of mass storage and an impact printer with alphanumeric and graphic capabilities. In a test which included 55 separate readings of 34 12- or 24-hour tapes, correlations with hand counts of vpbs was greater than .99. The system processes either cassette or reel-to-reel tapes at 120* with simultaneous print/process capabilities, has a variety of user interactive displays to assure continuous operator validation, is remarkably nonfatiguing to operate, and automatically produces reports with tables, graphs, and sample ECG strips. 8 references.

  13. Quantifying fault recovery in multiprocessor systems

    NASA Technical Reports Server (NTRS)

    Malek, Miroslaw; Harary, Frank

    1990-01-01

    Various aspects of reliable computing are formalized and quantified with emphasis on efficient fault recovery. The mathematical model which proves to be most appropriate is provided by the theory of graphs. New measures for fault recovery are developed and the value of elements of the fault recovery vector are observed to depend not only on the computation graph H and the architecture graph G, but also on the specific location of a fault. In the examples, a hypercube is chosen as a representative of parallel computer architecture, and a pipeline as a typical configuration for program execution. Dependability qualities of such a system is defined with or without a fault. These qualities are determined by the resiliency triple defined by three parameters: multiplicity, robustness, and configurability. Parameters for measuring the recovery effectiveness are also introduced in terms of distance, time, and the number of new, used, and moved nodes and edges.

  14. A measurement-based performability model for a multiprocessor system

    NASA Technical Reports Server (NTRS)

    Ilsueh, M. C.; Iyer, Ravi K.; Trivedi, K. S.

    1987-01-01

    A measurement-based performability model based on real error-data collected on a multiprocessor system is described. Model development from the raw errror-data to the estimation of cumulative reward is described. Both normal and failure behavior of the system are characterized. The measured data show that the holding times in key operational and failure states are not simple exponential and that semi-Markov process is necessary to model the system behavior. A reward function, based on the service rate and the error rate in each state, is then defined in order to estimate the performability of the system and to depict the cost of different failure types and recovery procedures.

  15. A parallel multigrid method for data-driven multiprocessor systems

    SciTech Connect

    Lin, C.H.; Gaudiot, J.L.; Proskurowski, W.

    1989-12-31

    The multigrid algorithm (MG) is recognized as an efficient and rapidly converging method to solve a wide family of partial differential equations (PDE). When this method is implemented on a multiprocessor system, its major drawback is the low utilization of processors. Due to the sequentiality of the standard algorithm, the fine grid levels cannot start relaxation until the coarse grid levels complete their own relaxation. Indeed, of all processors active on the fine two dimensional grid level only one fourth will be active at the coarse grid level, leaving full 75% idle. In this paper, a novel parallel V-cycle multigrid (PVM) algorithm is proposed to cure the idle processors` problem. Highly programmable systems such as data-flow architectures are then applied to support this new algorithm. The experiments based on the proposed architecture show that the convergence rate of the new algorithm is about twice faster than that of the standard method and twice as efficient system utilization is achieved.

  16. Dynamically reconfigurable optical interconnect architecture for parallel multiprocessor systems

    NASA Astrophysics Data System (ADS)

    Girard, Mary M.; Husbands, Charles R.; Antoszewska, Reza

    1991-12-01

    The progress in parallel processing technology in recent years has resulted in increased requirements to process large amounts of data in real time. The massively parallel architectures proposed for these applications require the use of a high speed interconnect system to achieve processor-to-processor connectivity without incurring excessive delays. The characteristics of optical components permit high speed operation while the nonconductive nature of the optical medium eliminates ground loop and transmission line problems normally associated with a conductive medium. The MITRE Corp. is evaluating an optical wavelength division multiple access interconnect network design to improve interconnectivity within parallel processor systems and to allow reconfigurability of processor communication paths. This paper describes the architecture and control of and highlights the results from an 8- channel multiprocessor prototype with effective throughput of 3.2 Gigabits per second (Gbps).

  17. Fault-tolerant interconnection networks for multiprocessor systems

    SciTech Connect

    Nassar, H.M.

    1989-01-01

    Interconnection networks represent the backbone of multiprocessor systems. A failure in the network, therefore, could seriously degrade the system performance. For this reason, fault tolerance has been regarded as a major consideration in interconnection network design. This thesis presents two novel techniques to provide fault tolerance capabilities to three major networks: the Beneline network and the Clos network. First, the Simple Fault Tolerance Technique (SFT) is presented. The SFT technique is in fact the result of merging two widely known interconnection mechanisms: a normal interconnection network and a shared bus. This technique is most suitable for networks with small switches, such as the Baseline network and the Benes network. For the Clos network, whose switches may be large for the SFT, another technique is developed to produce the Fault-Tolerant Clos (FTC) network. In the FTC, one switch is added to each stage. The two techniques are described and thoroughly analyzed.

  18. Multiprocessor system with daisy-chained processor selection

    SciTech Connect

    Yamanaka, K.

    1988-09-27

    A multiprocessor system is described comprising: a bus, a master operation processing unit connected to the bus for generating on the bus data to be processes and a command for processing the data, slave operation processing units connected to the bus for receiving the data and the command from the master operation processing unit. The salve operation processing unit includes a priority discriminator which sequentially selects the slave operation processing units in a preset priority sequence. The priority discriminator also includes means for determining conditions of each of the slave operation processing units and means for initiating execution of the command in the first slave operation processing units selected in the preset priority sequence which has its determined conditions meeting preselected conditions. The initiated slave operation processing unit includes means for processing the data in accordance with the command.

  19. Method and apparatus for single-stepping coherence events in a multiprocessor system under software control

    DOEpatents

    Blumrich, Matthias A.; Salapura, Valentina

    2010-11-02

    An apparatus and method are disclosed for single-stepping coherence events in a multiprocessor system under software control in order to monitor the behavior of a memory coherence mechanism. Single-stepping coherence events in a multiprocessor system is made possible by adding one or more step registers. By accessing these step registers, one or more coherence requests are processed by the multiprocessor system. The step registers determine if the snoop unit will operate by proceeding in a normal execution mode, or operate in a single-step mode.

  20. An embedded multiprocessor computer for proof-of-principle testing of exploratory systems concepts

    SciTech Connect

    Borgman, C.R.; Dalton, L.J.

    1987-01-01

    This paper discusses the SANDAC V multiprocessor embedded computer hardware and software. Its expandable design provides adequate computing power for testing of various proof-of-principle (POP) exploratory system concepts. It is built from state-of-the-art integrated circuits with ASIC glue chips. A powerful software development system, multiprocessor on-board debugger, and a multitasking operating system kernel provide a user friendly software environment to complement the hardware.

  1. Efficient diagnosis of multiprocessor systems under probabilistic models

    NASA Technical Reports Server (NTRS)

    Blough, Douglas M.; Sullivan, Gregory F.; Masson, Gerald M.

    1989-01-01

    The problem of fault diagnosis in multiprocessor systems is considered under a probabilistic fault model. The focus is on minimizing the number of tests that must be conducted in order to correctly diagnose the state of every processor in the system with high probability. A diagnosis algorithm that can correctly diagnose the state of every processor with probability approaching one in a class of systems performing slightly greater than a linear number of tests is presented. A nearly matching lower bound on the number of tests required to achieve correct diagnosis in arbitrary systems is also proven. Lower and upper bounds on the number of tests required for regular systems are also presented. A class of regular systems which includes hypercubes is shown to be correctly diagnosable with high probability. In all cases, the number of tests required under this probabilistic model is shown to be significantly less than under a bounded-size fault set model. Because the number of tests that must be conducted is a measure of the diagnosis overhead, these results represent a dramatic improvement in the performance of system-level diagnosis techniques.

  2. Software Coherence in Multiprocessor Memory Systems. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Bolosky, William Joseph

    1993-01-01

    Processors are becoming faster and multiprocessor memory interconnection systems are not keeping up. Therefore, it is necessary to have threads and the memory they access as near one another as possible. Typically, this involves putting memory or caches with the processors, which gives rise to the problem of coherence: if one processor writes an address, any other processor reading that address must see the new value. This coherence can be maintained by the hardware or with software intervention. Systems of both types have been built in the past; the hardware-based systems tended to outperform the software ones. However, the ratio of processor to interconnect speed is now so high that the extra overhead of the software systems may no longer be significant. This issue is explored both by implementing a software maintained system and by introducing and using the technique of offline optimal analysis of memory reference traces. It finds that in properly built systems, software maintained coherence can perform comparably to or even better than hardware maintained coherence. The architectural features necessary for efficient software coherence to be profitable include a small page size, a fast trap mechanism, and the ability to execute instructions while remote memory references are outstanding.

  3. Program partitioning for NUMA multiprocessor computer systems. [Nonuniform memory access

    SciTech Connect

    Wolski, R.M.; Feo, J.T. )

    1993-11-01

    Program partitioning and scheduling are essential steps in programming non-shared-memory computer systems. Partitioning is the separation of program operations into sequential tasks, and scheduling is the assignment of tasks to processors. To be effective, automatic methods require an accurate representation of the model of computation and the target architecture. Current partitioning methods assume today's most prevalent models -- macro dataflow and a homogeneous/two-level multicomputer system. Based on communication channels, neither model represents well the emerging class of NUMA multiprocessor computer systems consisting of hierarchical read/write memories. Consequently, the partitions generated by extant methods do not execute well on these systems. In this paper, the authors extend the conventional graph representation of the macro-dataflow model to enable mapping heuristics to consider the complex communication options supported by NUMA architectures. They describe two such heuristics. Simulated execution times of program graphs show that the model and heuristics generate higher quality program mappings than current methods for NUMA architectures.

  4. MULTIPROCESSOR AND DISTRIBUTED PROCESSING BIBLIOGRAPHIC DATA BASE SOFTWARE SYSTEM

    NASA Technical Reports Server (NTRS)

    Miya, E. N.

    1994-01-01

    Multiprocessors and distributed processing are undergoing increased scientific scrutiny for many reasons. It is more and more difficult to keep track of the existing research in these fields. This package consists of a large machine-readable bibliographic data base which, in addition to the usual keyword searches, can be used for producing citations, indexes, and cross-references. The data base is compiled from smaller existing multiprocessing bibliographies, and tables of contents from journals and significant conferences. There are approximately 4,000 entries covering topics such as parallel and vector processing, networks, supercomputers, fault-tolerant computers, and cellular automata. Each entry is represented by 21 fields including keywords, author, referencing book or journal title, volume and page number, and date and city of publication. The data base contains UNIX 'refer' formatted ASCII data and can be implemented on any computer running under the UNIX operating system. The data base requires approximately one megabyte of secondary storage. The documentation for this program is included with the distribution tape, although it can be purchased for the price below. This bibliography was compiled in 1985 and updated in 1988.

  5. Clock synchronization of a large multiprocessor system in the presence of malicious faults

    NASA Technical Reports Server (NTRS)

    Shin, Kang G.; Ramanathan, P.

    1987-01-01

    An interconnection algorithm is presented for achieving clock synchronization in a multiprocessor system. The system is assumed to be maliciously faulty, i.e., some processors are out of synchronization and lie about their clock state to other intragroup or intergroup processors. A phase-locked clock network design is proposed which groups the clocks in the system into diverse clusters. The clusters are then treated as single clock units from the perspective of the network. The algorithm minimizes the number of interconnections while permitting synchronization of large multiprocessor systems controlling time-critical applications such as aircraft, nuclear reactors and industrial processes.

  6. A general model for memory interference in a multiprocessor system with memory hierarchy

    NASA Technical Reports Server (NTRS)

    Taha, Badie A.; Standley, Hilda M.

    1989-01-01

    The problem of memory interference in a multiprocessor system with a hierarchy of shared buses and memories is addressed. The behavior of the processors is represented by a sequence of memory requests with each followed by a determined amount of processing time. A statistical queuing network model for determining the extent of memory interference in multiprocessor systems with clusters of memory hierarchies is presented. The performance of the system is measured by the expected number of busy memory clusters. The results of the analytic model are compared with simulation results, and the correlation between them is found to be very high.

  7. Operating system for a real-time multiprocessor propulsion system simulator

    NASA Technical Reports Server (NTRS)

    Cole, G. L.

    1984-01-01

    The success of the Real Time Multiprocessor Operating System (RTMPOS) in the development and evaluation of experimental hardware and software systems for real time interactive simulation of air breathing propulsion systems was evaluated. The Real Time Multiprocessor Operating System (RTMPOS) provides the user with a versatile, interactive means for loading, running, debugging and obtaining results from a multiprocessor based simulator. A front end processor (FEP) serves as the simulator controller and interface between the user and the simulator. These functions are facilitated by the RTMPOS which resides on the FEP. The RTMPOS acts in conjunction with the FEP's manufacturer supplied disk operating system that provides typical utilities like an assembler, linkage editor, text editor, file handling services, etc. Once a simulation is formulated, the RTMPOS provides for engineering level, run time operations such as loading, modifying and specifying computation flow of programs, simulator mode control, data handling and run time monitoring. Run time monitoring is a powerful feature of RTMPOS that allows the user to record all actions taken during a simulation session and to receive advisories from the simulator via the FEP. The RTMPOS is programmed mainly in PASCAL along with some assembly language routines. The RTMPOS software is easily modified to be applicable to hardware from different manufacturers.

  8. Intercrate-communications controller for multicrate multiprocessor systems that use CAMAC-COMPEX protocol

    SciTech Connect

    Basiladze, S.G.; Kybnikov, V.M.

    1986-07-01

    This paper describes a controller for organization of intercrate communications in multicrate multiprocessor systems by means of an intercrate dataway that follows the structure of a COMEX dataway. The intercrate controller makes it possible to create multicrate multiprocessor systems with ordinary CAMAC slave modules. The crate-communications controller is implemented as an auxiliary crate controller and requires at the 25th station an EUR6500e-compatible device for communications between the main and auxiliary dataways. Two light-emitting diodes on the front panel indicate which of the dataways has been captured by the controller. The controller is designed for operation with intercrate dataway lines that are matched by means of one or two terminators. The matching network must have the equivalent circuit of a resistor of 110-130 ohm connected to a source of 3.5-4.5 V.

  9. High Performance, Dependable Multiprocessor

    NASA Technical Reports Server (NTRS)

    Ramos, Jeremy; Samson, John R.; Troxel, Ian; Subramaniyan, Rajagopal; Jacobs, Adam; Greco, James; Cieslewski, Grzegorz; Curreri, John; Fischer, Michael; Grobelny, Eric; George, Alan; Aggarwal, Vikas; Patel, Minesh; Some, Raphael

    2006-01-01

    With the ever increasing demand for higher bandwidth and processing capacity of today's space exploration, space science, and defense missions, the ability to efficiently apply commercial-off-the-shelf (COTS) processors for on-board computing is now a critical need. In response to this need, NASA's New Millennium Program office has commissioned the development of Dependable Multiprocessor (DM) technology for use in payload and robotic missions. The Dependable Multiprocessor technology is a COTS-based, power efficient, high performance, highly dependable, fault tolerant cluster computer. To date, Honeywell has successfully demonstrated a TRL4 prototype of the Dependable Multiprocessor [I], and is now working on the development of a TRLS prototype. For the present effort Honeywell has teamed up with the University of Florida's High-performance Computing and Simulation (HCS) Lab, and together the team has demonstrated major elements of the Dependable Multiprocessor TRLS system.

  10. 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.

  11. Energy-efficient fault tolerance in multiprocessor real-time systems

    NASA Astrophysics Data System (ADS)

    Guo, Yifeng

    The recent progress in the multiprocessor/multicore systems has important implications for real-time system design and operation. From vehicle navigation to space applications as well as industrial control systems, the trend is to deploy multiple processors in real-time systems: systems with 4 -- 8 processors are common, and it is expected that many-core systems with dozens of processing cores will be available in near future. For such systems, in addition to general temporal requirement common for all real-time systems, two additional operational objectives are seen as critical: energy efficiency and fault tolerance. An intriguing dimension of the problem is that energy efficiency and fault tolerance are typically conflicting objectives, due to the fact that tolerating faults (e.g., permanent/transient) often requires extra resources with high energy consumption potential. In this dissertation, various techniques for energy-efficient fault tolerance in multiprocessor real-time systems have been investigated. First, the Reliability-Aware Power Management (RAPM) framework, which can preserve the system reliability with respect to transient faults when Dynamic Voltage Scaling (DVS) is applied for energy savings, is extended to support parallel real-time applications with precedence constraints. Next, the traditional Standby-Sparing (SS) technique for dual processor systems, which takes both transient and permanent faults into consideration while saving energy, is generalized to support multiprocessor systems with arbitrary number of identical processors. Observing the inefficient usage of slack time in the SS technique, a Preference-Oriented Scheduling Framework is designed to address the problem where tasks are given preferences for being executed as soon as possible (ASAP) or as late as possible (ALAP). A preference-oriented earliest deadline (POED) scheduler is proposed and its application in multiprocessor systems for energy-efficient fault tolerance is

  12. A high speed multi-tasking, multi-processor telemetry system

    SciTech Connect

    Wu, Kung Chris

    1996-12-31

    This paper describes a small size, light weight, multitasking, multiprocessor telemetry system capable of collecting 32 channels of differential signals at a sampling rate of 6.25 kHz per channel. The system is designed to collect data from remote wind turbine research sites and transfer the data via wireless communication. A description of operational theory, hardware components, and itemized cost is provided. Synchronization with other data acquisition systems and test data on data transmission rates is also given. 11 refs., 7 figs., 4 tabs.

  13. ScalaBLAST 2.0: Rapid and robust BLAST calculations on multiprocessor systems

    SciTech Connect

    Oehmen, Christopher S.; Baxter, Douglas J.

    2013-03-15

    BLAST remains one of the most widely used tools in computational biology. The rate at which new sequence data is available continues to grow exponentially, driving the emergence of new fields of biological research. At the same time multicore systems and conventional clusters are more accessible. ScalaBLAST has been designed to run on conventional multiprocessor systems with an eye to extreme parallelism, enabling parallel BLAST calculations using over 16,000 processing cores with a portable, robust, fault-resilient design. ScalaBLAST 2.0 source code can be freely downloaded from http://omics.pnl.gov/software/ScalaBLAST.php.

  14. Architecture and applications of the HEP multiprocessor computer system

    SciTech Connect

    Smith, B.J.

    1981-01-01

    The HEP computer system is a large scale scientific parallel computer employing shared-resource MIMD architecture. The hardware and software facilities provided by the system are described, and techniques found useful in programming the system are discussed. 3 references.

  15. Embedded Multiprocessor Technology for VHSIC Insertion

    NASA Technical Reports Server (NTRS)

    Hayes, Paul J.

    1990-01-01

    Viewgraphs on embedded multiprocessor technology for VHSIC insertion are presented. The objective was to develop multiprocessor system technology providing user-selectable fault tolerance, increased throughput, and ease of application representation for concurrent operation. The approach was to develop graph management mapping theory for proper performance, model multiprocessor performance, and demonstrate performance in selected hardware systems.

  16. Generation-based memory synchronization in a multiprocessor system with weakly consistent memory accesses

    DOEpatents

    Ohmacht, Martin

    2014-09-09

    In a multiprocessor system, a central memory synchronization module coordinates memory synchronization requests responsive to memory access requests in flight, a generation counter, and a reclaim pointer. The central module communicates via point-to-point communication. The module includes a global OR reduce tree for each memory access requesting device, for detecting memory access requests in flight. An interface unit is implemented associated with each processor requesting synchronization. The interface unit includes multiple generation completion detectors. The generation count and reclaim pointer do not pass one another.

  17. Engineering study for the functional design of a multiprocessor system

    NASA Technical Reports Server (NTRS)

    Miller, J. S.; Vandever, W. H.; Stanten, S. F.; Avakian, A. E.; Kosmala, A. L.

    1972-01-01

    The results are presented of a study to generate a functional system design of a multiprocessing computer system capable of satisfying the computational requirements of a space station. These data management system requirements were specified to include: (1) real time control, (2) data processing and storage, (3) data retrieval, and (4) remote terminal servicing.

  18. Architecture and applications of the HEP multiprocessor computer system

    SciTech Connect

    Smith, B.J.; Fink, D.J.

    1982-01-01

    The HEP computer system is a large scale scientific parallel computer employing shared resource MIMD architecture. The hardware and software facilities provided by the system are described, and techniques found to be useful in programming the system are also discussed. 3 references.

  19. Parallel implementation of arbitrary-shaped MPEG-4 decoder for multiprocessor systems

    NASA Astrophysics Data System (ADS)

    Pastrnak, Milan; de With, Peter H. N.; Stuijk, Sander; van Meerbergen, Jef

    2006-01-01

    MPEG-4 is the first standard that combines synthetic objects, like 2D/3D graphics objects, with natural rectangular and non-rectangular video objects. The independent access to individual synthetic video objects for further manipulation creates a large space for future applications. This paper addresses the optimization of such complex multimedia algorithms for implementation on multiprocessor platforms. It is shown that when choosing the correct granularity of processing for enhanced parallelism and splitting time-critical tasks, a substantial improvement in processing efficiency can be obtained. In our work, we focus on non-rectangular (also called arbitrary-shaped) video objects decoder. In previous work, we motivated the use of a multiprocessor System-on-Chip(SoC) setup that satisfies the requirements on the overall computation capacity. We propose the optimization of the MPEG-4 algorithm to increase the decoding throughput and a more efficient usage of the multiprocessor architecture. First, we present a modification of the Repetitive Padding to increase the pipelining at block level. We identified the part of the padding algorithm that can be executed in parallel with the DCT-coefficient decoding and modified the original algorithm into two communicating tasks. Second, we introduce a synchronization mechanism that allows the processing for the Extended Padding and postprocessing (Deblocking & Deringing) filters at block level. The first optimization results in about 58% decrease of the original Repetitive-Padding task computational requirements. By introducing the previously proposed data-level parallelism and exploiting the inherent parallelism between the separated color components (Y, Cr, Cb), the computational savings are about 72% on the average. Moreover, the proposed optimizations marginalize the processing latency from frame size to slice order-of-magnitude.

  20. FPGA-Based Multiprocessor System for Injection Molding Control

    PubMed Central

    Muñoz-Barron, Benigno; Morales-Velazquez, Luis; Romero-Troncoso, Rene J.; Rodriguez-Donate, Carlos; Trejo-Hernandez, Miguel; Benitez-Rangel, Juan P.; Osornio-Rios, Roque A.

    2012-01-01

    The plastic industry is a very important manufacturing sector and injection molding is a widely used forming method in that industry. The contribution of this work is the development of a strategy to retrofit control of an injection molding machine based on an embedded system microprocessors sensor network on a field programmable gate array (FPGA) device. Six types of embedded processors are included in the system: a smart-sensor processor, a micro fuzzy logic controller, a programmable logic controller, a system manager, an IO processor and a communication processor. Temperature, pressure and position are controlled by the proposed system and experimentation results show its feasibility and robustness. As validation of the present work, a particular sample was successfully injected. PMID:23202036

  1. FPGA-based multiprocessor system for injection molding control.

    PubMed

    Muñoz-Barron, Benigno; Morales-Velazquez, Luis; Romero-Troncoso, Rene J; Rodriguez-Donate, Carlos; Trejo-Hernandez, Miguel; Benitez-Rangel, Juan P; Osornio-Rios, Roque A

    2012-01-01

    The plastic industry is a very important manufacturing sector and injection molding is a widely used forming method in that industry. The contribution of this work is the development of a strategy to retrofit control of an injection molding machine based on an embedded system microprocessors sensor network on a field programmable gate array (FPGA) device. Six types of embedded processors are included in the system: a smart-sensor processor, a micro fuzzy logic controller, a programmable logic controller, a system manager, an IO processor and a communication processor. Temperature, pressure and position are controlled by the proposed system and experimentation results show its feasibility and robustness. As validation of the present work, a particular sample was successfully injected. PMID:23202036

  2. Scheduler for multiprocessor system switch with selective pairing

    DOEpatents

    Gara, Alan; Gschwind, Michael Karl; Salapura, Valentina

    2015-01-06

    System, method and computer program product for scheduling threads in a multiprocessing system with selective pairing of processor cores for increased processing reliability. A selective pairing facility is provided that selectively connects, i.e., pairs, multiple microprocessor or processor cores to provide one highly reliable thread (or thread group). The method configures the selective pairing facility to use checking provide one highly reliable thread for high-reliability and allocate threads to corresponding processor cores indicating need for hardware checking. The method configures the selective pairing facility to provide multiple independent cores and allocate threads to corresponding processor cores indicating inherent resilience.

  3. A hybrid pyramid multiprocessor system for image processing. Volumes I and II

    SciTech Connect

    Chen, Inching.

    1989-01-01

    Various multiprocessor architectures have been considered by many researchers to handle the high computational requirements of image processing and analysis application. However, many of these architectures are efficient only for a small class of image processing algorithms. In this research, a multiprocessor system has been proposed, designed and constructed taking into consideration various input-output and other characteristics of image processing applications. It is a hybrid pyramid with five 68020-68881 based processor nodes in the top two layers and sixteen DSP56001 based processor nodes in the third layer. The DSP (RISC) processor nodes at the bottom level are optimized for low-level image processing operations and the CISC (68020) processor nodes handle high-level tasks more efficiently. Experiments using the algorithms that have operations on neighborhoods of different sizes have shown consistent improvement in performance if the FIFO cache is enabled. Larger neighborhoods result in greater saving in time. Preliminary test indicate that the top five processor nodes can execute five times as fast as a single node for many image processing tasks. Finally, the versatile image I/O with the MMU has created a simpler programming environment, while facilitating various I/O structures. The OSU pyramid is a general-purpose image processing system, utilizing pyramidal architecture of hybrid processors, with additional hardware to retain the advantageous features of array processors, as well as to overcome some of the inherent deficiencies of pipeline processors and cellular arrays.

  4. Common interface real-time multiprocessor operating system for embedded systems. Master's thesis

    SciTech Connect

    Rottman, M.S.

    1991-03-04

    Large real time applications such as aerospace avionics systems, battle management, and factory automation place many demands and constraints on the computing system not found in other applications. Software development is hindered by software dependence on the computer architecture and the lack of portability between systems. This thesis specifies and designs a real time multiprocessor operating system (RTMOS) that implements a consistent programming model, enabling the development of real time parallel software independent of the target architecture. The RTMOS defines the core functionality required to demonstrate the programming model. The RTMOS functional requirements are specified using Structured Analysis and Design Technique (SADT). A hybrid of the Design Approach for Real-Time Software (DARTS) is used to perform the preliminary and detailed designs. The preliminary design is architecture-independent; the detailed design phase maps the design to a specific parallel system, the Intel iPSC/2 hypercube. The modular RTMOS design partitions operating system operations and data structures from hardware-dependent functions for portability.

  5. Multiprocessor architectural study

    NASA Technical Reports Server (NTRS)

    Kosmala, A. L.; Stanten, S. F.; Vandever, W. H.

    1972-01-01

    An architectural design study was made of a multiprocessor computing system intended to meet functional and performance specifications appropriate to a manned space station application. Intermetrics, previous experience, and accumulated knowledge of the multiprocessor field is used to generate a baseline philosophy for the design of a future SUMC* multiprocessor. Interrupts are defined and the crucial questions of interrupt structure, such as processor selection and response time, are discussed. Memory hierarchy and performance is discussed extensively with particular attention to the design approach which utilizes a cache memory associated with each processor. The ability of an individual processor to approach its theoretical maximum performance is then analyzed in terms of a hit ratio. Memory management is envisioned as a virtual memory system implemented either through segmentation or paging. Addressing is discussed in terms of various register design adopted by current computers and those of advanced design.

  6. HyperForest: A high performance multi-processor architecture for real-time intelligent systems

    SciTech Connect

    Garcia, P. Jr.; Rebeil, J.P.; Pollard, H.

    1997-04-01

    Intelligent Systems are characterized by the intensive use of computer power. The computer revolution of the last few years is what has made possible the development of the first generation of Intelligent Systems. Software for second generation Intelligent Systems will be more complex and will require more powerful computing engines in order to meet real-time constraints imposed by new robots, sensors, and applications. A multiprocessor architecture was developed that merges the advantages of message-passing and shared-memory structures: expendability and real-time compliance. The HyperForest architecture will provide an expandable real-time computing platform for computationally intensive Intelligent Systems and open the doors for the application of these systems to more complex tasks in environmental restoration and cleanup projects, flexible manufacturing systems, and DOE`s own production and disassembly activities.

  7. Multiprocessor programming environment

    SciTech Connect

    Smith, M.B.; Fornaro, R.

    1988-12-01

    Programming tools and techniques have been well developed for traditional uniprocessor computer systems. The focus of this research project is on the development of a programming environment for a high speed real time heterogeneous multiprocessor system, with special emphasis on languages and compilers. The new tools and techniques will allow a smooth transition for programmers with experience only on single processor systems.

  8. Job-mix modeling and system analysis of an aerospace multiprocessor.

    NASA Technical Reports Server (NTRS)

    Mallach, E. G.

    1972-01-01

    An aerospace guidance computer organization, consisting of multiple processors and memory units attached to a central time-multiplexed data bus, is described. A job mix for this type of computer is obtained by analysis of Apollo mission programs. Multiprocessor performance is then analyzed using: 1) queuing theory, under certain 'limiting case' assumptions; 2) Markov process methods; and 3) system simulation. Results of the analyses indicate: 1) Markov process analysis is a useful and efficient predictor of simulation results; 2) efficient job execution is not seriously impaired even when the system is so overloaded that new jobs are inordinately delayed in starting; 3) job scheduling is significant in determining system performance; and 4) a system having many slow processors may or may not perform better than a system of equal power having few fast processors, but will not perform significantly worse.

  9. Commodity multi-processor systems in the ATLAS level-2 trigger

    SciTech Connect

    Abolins, M.; Blair, R.; Bock, R.; Bogaerts, A.; Dawson, J.; Ermoline, Y.; Hauser, R.; Kugel, A.; Lay, R.; Muller, M.; Noffz, K.-H.; Pope, B.; Schlereth, J.; Werner, P.

    2000-05-23

    Low cost SMP (Symmetric Multi-Processor) systems provide substantial CPU and I/O capacity. These features together with the ease of system integration make them an attractive and cost effective solution for a number of real-time applications in event selection. In ATLAS the authors consider them as intelligent input buffers (active ROB complex), as event flow supervisors or as powerful processing nodes. Measurements of the performance of one off-the-shelf commercial 4-processor PC with two PCI buses, equipped with commercial FPGA based data source cards (microEnable) and running commercial software are presented and mapped on such applications together with a long-term program of work. The SMP systems may be considered as an important building block in future data acquisition systems.

  10. Closed-form solutions of performability. [modeling of a degradable buffer/multiprocessor system

    NASA Technical Reports Server (NTRS)

    Meyer, J. F.

    1981-01-01

    Methods which yield closed form performability solutions for continuous valued variables are developed. The models are similar to those employed in performance modeling (i.e., Markovian queueing models) but are extended so as to account for variations in structure due to faults. In particular, the modeling of a degradable buffer/multiprocessor system is considered whose performance Y is the (normalized) average throughput rate realized during a bounded interval of time. To avoid known difficulties associated with exact transient solutions, an approximate decomposition of the model is employed permitting certain submodels to be solved in equilibrium. These solutions are then incorporated in a model with fewer transient states and by solving the latter, a closed form solution of the system's performability is obtained. In conclusion, some applications of this solution are discussed and illustrated, including an example of design optimization.

  11. Shared versus distributed memory multiprocessors

    NASA Technical Reports Server (NTRS)

    Jordan, Harry F.

    1991-01-01

    The question of whether multiprocessors should have shared or distributed memory has attracted a great deal of attention. Some researchers argue strongly for building distributed memory machines, while others argue just as strongly for programming shared memory multiprocessors. A great deal of research is underway on both types of parallel systems. Special emphasis is placed on systems with a very large number of processors for computation intensive tasks and considers research and implementation trends. It appears that the two types of systems will likely converge to a common form for large scale multiprocessors.

  12. Real-time aware rendering of scalable arbitrary-shaped MPEG-4 decoder for multiprocessor systems

    NASA Astrophysics Data System (ADS)

    Pastrnak, Milan; de With, Peter H. N.; van Meerbergen, Jef

    2007-02-01

    The MPEG-4 video standard extends the traditional frame-based processing with the option to compose several video objects (VO) superimposed on a background sprite image. In our previous work, we presented a distributed, multiprocessor based, scalable implementation of an MPEG-4 arbitrary-shaped decoder, which forms together with the background sprite decoder an essential part for further scene rendering. For control of the multiprocessor architecture, we have constructed a Quality-of-Service (QoS) management that monitors the availability of required data and distributes the processing of individual tasks with guaranteed or best-effort services of the platform. However, the proposed architecture with the combined guaranteed and best-effort services poses problems for real-time scene rendering. In this paper, we present a technique for proper run-time rendering of the final scene after decoding one VO Layer. The individual video-object monitors check the data availability and select the highest quality for the final scene rendering. The algorithm operates hierarchically both at the scene level and at the task level of the video object processing. Whereas the earlier work on scalable implementation concentrated only on guaranteed services, we now introduce a new element in the system architecture for the real-time control and fall back mechanism of the best-effort services. This element is based on first, controlling data availability at task level, and second, introducing the propagation service to QoS management. We present our simulation results in the comparison with the standard "frame-skipping" technique that is the only currently available solution to this type of rendering a scalable processing.

  13. Multiprocessor execution of functional programs

    SciTech Connect

    Goldberg, B. )

    1988-10-01

    Functional languages have recently gained attention as vehicles for programming in a concise and element manner. In addition, it has been suggested that functional programming provides a natural methodology for programming multiprocessor computers. This paper describes research that was performed to demonstrate that multiprocessor execution of functional programs on current multiprocessors is feasible, and results in a significant reduction in their execution times. Two implementations of the functional language ALFL were built on commercially available multiprocessors. Alfalfa is an implementation on the Intel iPSC hypercube multiprocessor, and Buckwheat is an implementation on the Encore Multimax shared-memory multiprocessor. Each implementation includes a compiler that performs automatic decomposition of ALFL programs and a run-time system that supports their execution. The compiler is responsible for detecting the inherent parallelism in a program, and decomposing the program into a collection of tasks, called serial combinators, that can be executed in parallel. The abstract machine model supported by Alfalfa and Buckwheat is called heterogeneous graph reduction, which is a hybrid of graph reduction and conventional stack-oriented execution. This model supports parallelism, lazy evaluation, and higher order functions while at the same time making efficient use of the processors in the system. The Alfalfa and Buckwheat runtime systems support dynamic load balancing, interprocessor communication (if required), and storage management. A large number of experiments were performed on Alfalfa and Buckwheat for a variety of programs. The results of these experiments, as well as the conclusions drawn from them, are presented.

  14. Fault-free behavior of reliable multiprocessor systems: FTMP experiments in AIRLAB

    NASA Technical Reports Server (NTRS)

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

    1985-01-01

    This report describes a set of experiments which were implemented on the Fault tolerant Multi-Processor (FTMP) at NASA/Langley's AIRLAB facility. These experiments are part of an effort to formulate and evaluate validation methodologies for fault-tolerant computers. This report deals with the measurement of single parameters (baselines) of a fault free system. The initial set of baseline experiments lead to the following conclusions: (1) The system clock is constant and independent of workload in the tested cases; (2) the instruction execution times are constant; (3) the R4 frame size is 40mS with some variation; (4) the frame stretching mechanism has some flaws in its implementation that allow the possibility of an infinite stretching of frame duration. Future experiments are planned. Some will broaden the results of these initial experiments. Others will measure the system more dynamically. The implementation of a synthetic workload generation mechanism for FTMP is planned to enhance the experimental environment of the system.

  15. MIMD (multiple instruction multiple data) multiprocessor system for real-time image processing

    NASA Astrophysics Data System (ADS)

    Pirsch, Peter; Jeschke, Hartwig

    1991-06-01

    Anovel MIMD (Multiple Instruction Multiple Data) based architecture consisting of multiple processing elements (PE) has been developed. This architecture is adapted to real-time processing of sequences of different tasks for local image segments. Each PE contains an arithmetic processing unit (APU), adapted to parallel processing of low level operations, and a high level and control processor (HLCP) for medium and high level operations and control of the PE. This HLCP can be a standard signal processor or a RISC processor. Because of the local control of each PE by the HLCP and a SIMD structure of the APU, the overall system architecture is characterized as MIMD based with a local SIMD structure for low level processing. Due to an overlapped computation and communication the multiprocessor system achieves a linear speedup compared to a single processing element. Main parts of the PE have been realized as two ASICs in a 1.5 jim CMOS-Process. With a system clock rate of 25MHz, each PE provides a peak performance of 400 Mega operations per second (MOPS).

  16. Data traffic reduction schemes for Cholesky factorization on asynchronous multiprocessor systems

    NASA Technical Reports Server (NTRS)

    Naik, Vijay K.; Patrick, Merrell L.

    1989-01-01

    Communication requirements of Cholesky factorization of dense and sparse symmetric, positive definite matrices are analyzed. The communication requirement is characterized by the data traffic generated on multiprocessor systems with local and shared memory. Lower bound proofs are given to show that when the load is uniformly distributed the data traffic associated with factoring an n x n dense matrix using n to the alpha power (alpha less than or equal 2) processors is omega(n to the 2 + alpha/2 power). For n x n sparse matrices representing a square root of n x square root of n regular grid graph the data traffic is shown to be omega(n to the 1 + alpha/2 power), alpha less than or equal 1. Partitioning schemes that are variations of block assignment scheme are described and it is shown that the data traffic generated by these schemes are asymptotically optimal. The schemes allow efficient use of up to O(n to the 2nd power) processors in the dense case and up to O(n) processors in the sparse case before the total data traffic reaches the maximum value of O(n to the 3rd power) and O(n to the 3/2 power), respectively. It is shown that the block based partitioning schemes allow a better utilization of the data accessed from shared memory and thus reduce the data traffic than those based on column-wise wrap around assignment schemes.

  17. The design of a high performance dataflow processor for multiprocessor systems

    SciTech Connect

    Luc, K.Q.

    1989-01-01

    The objective of this work is to design a high performance dynamic dataflow processor for multiprocessor systems. The performance of contemporary dataflow processors is limited due to the presence of a component, called a matching unit. The function of this unit is to match instruction tokens in order to detect the executability of instructions. Since activities within the matching unit are sequential in nature and require multiple memory accesses, the unit has been identified as a major performance bottleneck in a prototype processor. The author proposes a natural way to partition the set of tokens and present a new implementation for the matching unit, called an Instance-Based Matching Unit. The new unit requires tokens to be partitioned into blocks and allows matching of these blocks of tokens to proceed concurrently. With the new matching unit, substantial throughput enhancement for the unit is reported. He then analyzes the throughputs at various stages of a conventional dataflow processor. The results thus obtained direct us to propose an optimum configuration for an effective sub-processor. The maximum throughput of this sub-processor is determined by the throughput of a queue. With the sub-processor as a building block, a high performance dataflow processor is presented which consists of multiple copies of the sub-processor. Characteristics of the processor are studied with the Livermore Fortran Kernels as inputs. The performance of this processor is high, and the performance increases with the number of Sub-Processors.

  18. Reusing existing resources for testing a multi-processor system-on-chip

    NASA Astrophysics Data System (ADS)

    Lee, Seung Eun

    2013-03-01

    In this article, we propose a test strategy for a multi-processor system-on-chip and model the test time for distributed Intellectual Property (IP) cores. The proposed test methodology uses the existing on-chip resources, IP cores and network elements in network-on-chip. The use of embedded IP cores as a built- in self-test (BIST) module completes the test much faster than an external test and provides flexibility in the test program. Moreover, the reuse of the existing network resources as a test media eliminates additional test access mechanism (TAM) wires in the design and increases test parallelism, reducing the area and test time. Based on the proposed test methodology, we evaluate the test time for distributed IP cores. First, we define the model for a distributed IP core with four parameters in the context of test purposes. Next, the required test time is driven. Finally, we show the characteristics of IP cores for a parallel testing that provides useful information for the test scheduling.

  19. Multiprocessor computer system which includes n parallel-operating modules and an external apparatus, and computer module for use in such a system

    SciTech Connect

    Krol, T.; Van Gils, W.J.

    1989-11-28

    This patent describes a multiprocessor computer system. It includes a plurality of n parallel-operating computer modules, each of which is situated in its own fault isolation are. The computer system having a failure protection means for maintaining operability under failure of at most 1 {lt}e t {lt} n of the computer modules.

  20. Combinatorial reliability analysis of multiprocessor computers

    SciTech Connect

    Hwang, K.; Tian-Pong Chang

    1982-12-01

    The authors propose a combinatorial method to evaluate the reliability of multiprocessor computers. Multiprocessor structures are classified as crossbar switch, time-shared buses, and multiport memories. Closed-form reliability expressions are derived via combinatorial path enumeration on the probabilistic-graph representation of a multiprocessor system. The method can analyze the reliability performance of real systems like C.mmp, Tandem 16, and Univac 1100/80. User-oriented performance levels are defined for measuring the performability of degradable multiprocessor systems. For a regularly structured multiprocessor system, it is fast and easy to use this technique for evaluating system reliability with statistically independent component reliabilities. System availability can be also evaluated by this reliability study. 6 references.

  1. Efficient mapping algorithms for scheduling robot inverse dynamics computation on a multiprocessor system

    NASA Technical Reports Server (NTRS)

    Lee, C. S. G.; Chen, C. L.

    1989-01-01

    Two efficient mapping algorithms for scheduling the robot inverse dynamics computation consisting of m computational modules with precedence relationship to be executed on a multiprocessor system consisting of p identical homogeneous processors with processor and communication costs to achieve minimum computation time are presented. An objective function is defined in terms of the sum of the processor finishing time and the interprocessor communication time. The minimax optimization is performed on the objective function to obtain the best mapping. This mapping problem can be formulated as a combination of the graph partitioning and the scheduling problems; both have been known to be NP-complete. Thus, to speed up the searching for a solution, two heuristic algorithms were proposed to obtain fast but suboptimal mapping solutions. The first algorithm utilizes the level and the communication intensity of the task modules to construct an ordered priority list of ready modules and the module assignment is performed by a weighted bipartite matching algorithm. For a near-optimal mapping solution, the problem can be solved by the heuristic algorithm with simulated annealing. These proposed optimization algorithms can solve various large-scale problems within a reasonable time. Computer simulations were performed to evaluate and verify the performance and the validity of the proposed mapping algorithms. Finally, experiments for computing the inverse dynamics of a six-jointed PUMA-like manipulator based on the Newton-Euler dynamic equations were implemented on an NCUBE/ten hypercube computer to verify the proposed mapping algorithms. Computer simulation and experimental results are compared and discussed.

  2. Process Management and Exception Handling in Multiprocessor Operating Systems Using Object-Oriented Design Techniques. Revised Sep. 1988

    NASA Technical Reports Server (NTRS)

    Russo, Vincent; Johnston, Gary; Campbell, Roy

    1988-01-01

    The programming of the interrupt handling mechanisms, process switching primitives, scheduling mechanism, and synchronization primitives of an operating system for a multiprocessor require both efficient code in order to support the needs of high- performance or real-time applications and careful organization to facilitate maintenance. Although many advantages have been claimed for object-oriented class hierarchical languages and their corresponding design methodologies, the application of these techniques to the design of the primitives within an operating system has not been widely demonstrated. To investigate the role of class hierarchical design in systems programming, the authors have constructed the Choices multiprocessor operating system architecture the C++ programming language. During the implementation, it was found that many operating system design concerns can be represented advantageously using a class hierarchical approach, including: the separation of mechanism and policy; the organization of an operating system into layers, each of which represents an abstract machine; and the notions of process and exception management. In this paper, we discuss an implementation of the low-level primitives of this system and outline the strategy by which we developed our solution.

  3. Performance measures for multiprocessor controllers

    NASA Technical Reports Server (NTRS)

    Krishna, C. M.; Shin, K. G.

    1982-01-01

    Performance measures to characterize fault tolerant multiprocessors used in the control of critical processes are considered. Our performance indices are based on controller response time. By relating this to the needs of the application, we have been able to derive indices that faithfully reflect the performance of the multiprocessor in the context of the application, that permit the objective comparison of rival computer systems, and that can either be definitively estimated or objectively measured. An example of a controller in an idealized satellite application is provided.

  4. Parallel processing of real-time dynamic systems simulation on OSCAR (Optimally SCheduled Advanced multiprocessoR)

    NASA Technical Reports Server (NTRS)

    Kasahara, Hironori; Honda, Hiroki; Narita, Seinosuke

    1989-01-01

    Parallel processing of real-time dynamic systems simulation on a multiprocessor system named OSCAR is presented. In the simulation of dynamic systems, generally, the same calculation are repeated every time step. However, we cannot apply to Do-all or the Do-across techniques for parallel processing of the simulation since there exist data dependencies from the end of an iteration to the beginning of the next iteration and furthermore data-input and data-output are required every sampling time period. Therefore, parallelism inside the calculation required for a single time step, or a large basic block which consists of arithmetic assignment statements, must be used. In the proposed method, near fine grain tasks, each of which consists of one or more floating point operations, are generated to extract the parallelism from the calculation and assigned to processors by using optimal static scheduling at compile time in order to reduce large run time overhead caused by the use of near fine grain tasks. The practicality of the scheme is demonstrated on OSCAR (Optimally SCheduled Advanced multiprocessoR) which has been developed to extract advantageous features of static scheduling algorithms to the maximum extent.

  5. Parallel implementation and evaluation of motion estimation system algorithms on a distributed memory multiprocessor using knowledge based mappings

    NASA Technical Reports Server (NTRS)

    Choudhary, Alok Nidhi; Leung, Mun K.; Huang, Thomas S.; Patel, Janak H.

    1989-01-01

    Several techniques to perform static and dynamic load balancing techniques for vision systems are presented. These techniques are novel in the sense that they capture the computational requirements of a task by examining the data when it is produced. Furthermore, they can be applied to many vision systems because many algorithms in different systems are either the same, or have similar computational characteristics. These techniques are evaluated by applying them on a parallel implementation of the algorithms in a motion estimation system on a hypercube multiprocessor system. The motion estimation system consists of the following steps: (1) extraction of features; (2) stereo match of images in one time instant; (3) time match of images from different time instants; (4) stereo match to compute final unambiguous points; and (5) computation of motion parameters. It is shown that the performance gains when these data decomposition and load balancing techniques are used are significant and the overhead of using these techniques is minimal.

  6. Firefly: A multiprocessor workstation

    SciTech Connect

    Thacker, C.P.; Stewart, L.C.; Satterthwaite, E.H.

    1988-08-01

    Firefly is a shared memory multiprocessor workstation developed at the Digital Equipment Corporation Systems Research Center (SRC). A Firefly system consists of from one to nine VLSI VAX processors, each with a floating point accelerator and a cache. The caches are coherent, so that all processors see a consistent view of main memory. The Firefly runs a software system that emulates the Ultrix system call interface, and in addition provides support for multiprocessing through multiple threads of control in a single address space. Communication is provided uniformly through the use of remote procedure call. The authors describe the goals, hardware, software system, and performance of the Firefly, and discuss the extent to which SRC has been successful in providing software to take advantage of multi-processing.

  7. Multiprocessor execution of functional programs

    SciTech Connect

    Goldberg, B.F.

    1988-01-01

    Functional languages have recently gained attention as vehicles for programming in a concise and elegant manner. In addition, it has been suggested that functional programming provides a natural methodology for programming multiprocessor computers. This dissertation demonstrates that multiprocessor execution of functional programs is feasible, and results in a significant reduction in their execution times. Two implementations of the functional language ALFL were built on commercially available multiprocessors. ALFL is an implementation on the Intel iPSC hypercube multiprocessor, and Buckwheat is an implementation on the Encore Multimax shared-memory multiprocessor. Each implementation includes a compiler that performs automatic decomposition of ALFL programs. The compiler is responsible for detecting the inherent parallelism in a program, and decomposing the program into a collection of tasks, called serial combinators, that can be executed in parallel. One of the primary goals of the compiler is to generate serial combinators exhibiting the coarsest granularity possibly without sacrificing useful parallelism. This dissertation describes the algorithms used by the compiler to analyze, decompose, and optimize functional programs. The abstract machine model supported by Alfalfa and Buckwheat is called heterogeneous graph reduction, which is a hybrid of graph reduction and conventional stack-oriented execution. This model supports parallelism, lazy evaluation, and higher order functions while at the same time making efficient use of the processors in the system. The Alfalfa and Buckwheat run-time systems support dynamic load balancing, interprocessor communication (if required) and storage management. A large number of experiments were performed on Alfalfa and Buckwheat for a variety of programs. The results of these experiments, as well as the conclusions drawn from them, are presented.

  8. A design fix to supervisory control for fault-tolerant scheduling of real-time multiprocessor systems with aperiodic tasks

    NASA Astrophysics Data System (ADS)

    Devaraj, Rajesh; Sarkar, Arnab; Biswas, Santosh

    2015-11-01

    In the article 'Supervisory control for fault-tolerant scheduling of real-time multiprocessor systems with aperiodic tasks', Park and Cho presented a systematic way of computing a largest fault-tolerant and schedulable language that provides information on whether the scheduler (i.e., supervisor) should accept or reject a newly arrived aperiodic task. The computation of such a language is mainly dependent on the task execution model presented in their paper. However, the task execution model is unable to capture the situation when the fault of a processor occurs even before the task has arrived. Consequently, a task execution model that does not capture this fact may possibly be assigned for execution on a faulty processor. This problem has been illustrated with an appropriate example. Then, the task execution model of Park and Cho has been modified to strengthen the requirement that none of the tasks are assigned for execution on a faulty processor.

  9. Efficient multiprocessor architecture for digital signal processing

    SciTech Connect

    Auguin, M.; Boeri, F.

    1982-01-01

    There is a continuing pressure of better processing performances in numerical signal processing. Effective utilization of LSI semiconductor technology allows the consideration of multiprocessor architectures. The problem of interconnecting the components of the architecture arises. The authors describe a control algorithm of the Benes interconnection network in a asynchronous multiprocessor system. A simulation study of the time-shared bus, of the omega network, of the benes network and of the crossbar network gives a comparison of performances. 8 references.

  10. Multiprocessors and runtime compilation

    NASA Technical Reports Server (NTRS)

    Saltz, Joel; Berryman, Harry; Wu, Janet

    1990-01-01

    Runtime preprocessing plays a major role in many efficient algorithms in computer science, as well as playing an important role in exploiting multiprocessor architectures. Examples are given that elucidate the importance of runtime preprocessing and show how these optimizations can be integrated into compilers. To support the arguments, transformations implemented in prototype multiprocessor compilers are described and benchmarks from the iPSC2/860, the CM-2, and the Encore Multimax/320 are presented.

  11. Denelcor HEP multiprocessor simulator

    SciTech Connect

    Dunigan, T.H.

    1986-06-01

    The structure and use of a simulator for the Denelcor HEP multiprocessor are described. The simulator provides a multitasking environment for the development of parallel programs in C or FORTRAN using a library of subroutines that simulate the parallel programming constructs available on the HEP, a shared-memory multiprocessor. The simulator also provides a trace file that can be used for debugging, performance analysis, or graphical display. 7 refs., 4 figs.

  12. A fault-tolerant multiprocessor architecture for aircraft, volume 1. [autopilot configuration

    NASA Technical Reports Server (NTRS)

    Smith, T. B.; Hopkins, A. L.; Taylor, W.; Ausrotas, R. A.; Lala, J. H.; Hanley, L. D.; Martin, J. H.

    1978-01-01

    A fault-tolerant multiprocessor architecture is reported. This architecture, together with a comprehensive information system architecture, has important potential for future aircraft applications. A preliminary definition and assessment of a suitable multiprocessor architecture for such applications is developed.

  13. Multi-ring performance of the Kendall square multiprocessor

    SciTech Connect

    Dunigan, T.H.

    1994-03-01

    Performance of the hierarchical shared-memory system of the Kendall Square Research multiprocessor is measured and characterized. The performance of prefetch is measured. Latency, bandwidth, and contention are analyzed on a 4-ring, 128 processor system. Scalability comparisons are made with other shared-memory and distributed-memory multiprocessors.

  14. Multiprocessor smalltalk: Implementation, performance, and analysis

    SciTech Connect

    Pallas, J.I.

    1990-01-01

    Multiprocessor Smalltalk demonstrates the value of object-oriented programming on a multiprocessor. Its implementation and analysis shed light on three areas: concurrent programming in an object oriented language without special extensions, implementation techniques for adapting to multiprocessors, and performance factors in the resulting system. Adding parallelism to Smalltalk code is easy, because programs already use control abstractions like iterators. Smalltalk's basic control and concurrency primitives (lambda expressions, processes and semaphores) can be used to build parallel control abstractions, including parallel iterators, parallel objects, atomic objects, and futures. Language extensions for concurrency are not required. This implementation demonstrates that it is possible to build an efficient parallel object-oriented programming system and illustrates techniques for doing so. Three modification tools-serialization, replication, and reorganization-adapted the Berkeley Smalltalk interpreter to the Firefly multiprocessor. Multiprocessor Smalltalk's performance shows that the combination of multiprocessing and object-oriented programming can be effective: speedups (relative to the original serial version) exceed 2.0 for five processors on all the benchmarks; the median efficiency is 48%. Analysis shows both where performance is lost and how to improve and generalize the experimental results. Changes in the interpreter to support concurrency add at most 12% overhead; better access to per-process variables could eliminate much of that. Changes in the user code to express concurrency add as much as 70% overhead; this overhead could be reduced to 54% if blocks (lambda expressions) were reentrant. Performance is also lost when the program cannot keep all five processors busy.

  15. Experimenting With Multiprocessor Simulator Concepts

    NASA Technical Reports Server (NTRS)

    Blech, Richard A.; Williams, Anthony D.

    1989-01-01

    Multiple microcomputer system used to investigate application of parallel processing to real-time simulation. With dual-base architecture, each microcomputer communicates with corresponding microcomputer on opposite bus through dual-port interface memory. Transfers of data to and from front-end processor occur on interactive information bus. Transfers of data related to simulation calculations occur on real-time-information bus. System, called the real-time multiprocessor simulator (RTMPS), is tool for developing low-cost, portable, user-friendly simulators.

  16. Development of an ACP facility

    SciTech Connect

    Gil-Sung You; Won-Myung Choung; Jeong-Hoe Ku; il-Je Cho; Dong-Hak Kook; Kie-Chan Kwon; Eun-Pyo Lee; Ji-Sup Yoon; Seong-Won Park; Won-Kyung Lee

    2007-07-01

    KAERI has been developing an advanced spent fuel conditioning process (ACP). The ACP facility for a process demonstration consists of two air-sealed type hot cells. The safety analysis results showed that the facility was designed safely. The relevant integrated performance tests were also carried out successfully. (authors)

  17. Insertion of coherence requests for debugging a multiprocessor

    DOEpatents

    Blumrich, Matthias A.; Salapura, Valentina

    2010-02-23

    A method and system are disclosed to insert coherence events in a multiprocessor computer system, and to present those coherence events to the processors of the multiprocessor computer system for analysis and debugging purposes. The coherence events are inserted in the computer system by adding one or more special insert registers. By writing into the insert registers, coherence events are inserted in the multiprocessor system as if they were generated by the normal coherence protocol. Once these coherence events are processed, the processing of coherence events can continue in the normal operation mode.

  18. State recovery and lockstep execution restart in a system with multiprocessor pairing

    SciTech Connect

    Gara, Alan; Gschwind, Michael K; Salapura, Valentina

    2014-01-21

    System, method and computer program product for a multiprocessing system to offer selective pairing of processor cores for increased processing reliability. A selective pairing facility is provided that selectively connects, i.e., pairs, multiple microprocessor or processor cores to provide one highly reliable thread (or thread group). Each paired microprocessor or processor cores that provide one highly reliable thread for high-reliability connect with a system components such as a memory "nest" (or memory hierarchy), an optional system controller, and optional interrupt controller, optional I/O or peripheral devices, etc. The memory nest is attached to a selective pairing facility via a switch or a bus. Each selectively paired processor core is includes a transactional execution facility, whereing the system is configured to enable processor rollback to a previous state and reinitialize lockstep execution in order to recover from an incorrect execution when an incorrect execution has been detected by the selective pairing facility.

  19. Numerical Linear Algebra On The CEDAR Multiprocessor

    NASA Astrophysics Data System (ADS)

    Meier, Ulrike; Sameh, Ahmed

    1988-01-01

    In this paper we describe in some detail the architectural features of the CEDAR. multiprocessor. We also discuss strategies for implementation of dense matrix computations, and present performance results on one cluster for a variety of linear system solvers, eigenvalue problem solvers, as well as algorithms for solving linear least squares problems.

  20. Neural networks and MIMD-multiprocessors

    NASA Technical Reports Server (NTRS)

    Vanhala, Jukka; Kaski, Kimmo

    1990-01-01

    Two artificial neural network models are compared. They are the Hopfield Neural Network Model and the Sparse Distributed Memory model. Distributed algorithms for both of them are designed and implemented. The run time characteristics of the algorithms are analyzed theoretically and tested in practice. The storage capacities of the networks are compared. Implementations are done using a distributed multiprocessor system.

  1. The design, creation, and performance of the parallel multiprocessor nuclear physics data acquisition system, DAPHNE

    SciTech Connect

    Welch, L.C.; Moog, T.H.; Daly, R.T.; Videbaek, F.

    1986-01-01

    The ever increasing complexity of nuclear physics experiments places severe demands on computerized data acquisition systems. A natural evolution of these system, taking advantage of the independent nature of ''events'', is to use identical parallel microcomputers in a front end to simultaneously analyze separate events. Such a system has been developed at Argonne to serve the needs of the experimental program of ATLAS, a new superconducting heavy-ion accelerator and other on-going research. Using microcomputers based on the National Semiconductor 32016 microprocessor housed in a Multibus I cage, multi-VAX cpu power is obtained at a fraction of the cost of one VAX. The front end interfaces to a VAX 750 on which an extensive user friendly command language based on DCL resides. The whole system, known as DAPHNE, also provides the means to replay data using the same command language. Design concepts, data structures, performance, and experience to data are discussed. 5 refs., 2 figs.

  2. The design and performance of the parallel multiprocessor nuclear physics data acquisition system, DAPHNE

    SciTech Connect

    Welch, L.C.; Moog, T.H.; Daly, R.T.; Videbaek, F.

    1987-05-01

    The ever increasing complexity of nuclear physics experiments places severe demands on computerized data acquisition systems. A natural evolution of these systems, taking advantages of the independent nature of ''events,'' is to use identical parallel microcomputers in a front end to simultaneously analyze separate events. Such a system has been developed at Argonne to serve the needs of the experimental program of ATLAS, a new superconducting heavy-ion accelerator and other on-going research. Using microcomputers based on the National Semiconductor 32016 microprocessor housed in a Multibus I cage, CPU power equivalent to several VAXs is obtained at a fraction of the cost of one VAX. The front end interfacs to a VAX 11/750 on which an extensive user friendly command language based on DCL resides. The whole system, known as DAPHNE, also provides the means to reply data using the same command language. Design concepts, data structures, performance, and experience to data are discussed.

  3. Feedback control and beam diagnostic algorithms for a multiprocessor DSP system

    SciTech Connect

    Teytelman, D.; Claus, R.; Fox, J.; Hindi, H.; Linscott, I.; Prabhakar, S.; Drago, A.; Stover, G.

    1996-09-01

    The multibunch longitudinal feedback system developed for use by PEP-II, ALS and DA{Phi}NE uses a parallel array of digital signal processors to calculate the feedback signals from measurements of beam motion. The system is designed with general-purpose programmable elements which allow many feedback operating modes as well as system diagnostics, calibrations and accelerator measurements. The overall signal processing architecture of the system is illustrated. The real-time DSP algorithms and off-line postprocessing tools are presented. The problems in managing 320 K samples of data collected in one beam transient measurement are discussed and the solutions are presented. Example software structures are presented showing the beam feedback process, techniques for modal analysis of beam motion(used to quantify growth and damping rates of instabilities) and diagnostic functions (such as timing adjustment of beam pick-up and kicker components). These operating techniques are illustrated with example results obtained from the system installed at the Advanced Light Source at LBL.

  4. Feedback control and beam diagnostic algorithms for a multiprocessor DSP system

    SciTech Connect

    Teytelman, D.; Claus, R.; Fox, J.; Hindi, H.; Linscott, I.; Prabhakar, S.; Drago, A.; Stover, G.

    1997-01-01

    The multibunch longitudinal feedback system developed for use by PEP-II, ALS, and DA{Phi}NE uses a parallel array of digital signal processors (DSPs) to calculate the feedback signals from measurements of beam motion. The system is designed with general-purpose programmable elements which allow many feedback operating modes as well as system diagnostics, calibrations, and accelerator measurements. The overall signal processing architecture of the system is illustrated. The real-time DSP algorithms and off-line postprocessing tools are presented. The problems in managing 320k samples of data collected in one beam transient measurement are discussed and our solutions are presented. Example software structures are presented showing the beam feedback process, techniques for modal analysis of beam motion (used to quantify growth and damping rates of instabilities), and diagnostic functions (such as timing adjustment of beam pick-up and kicker components). These operating techniques are illustrated with example results obtained from the system installed at the Advanced Light Source at LBL. {copyright} {ital 1997 American Institute of Physics.}

  5. Considerations for Multiprocessor Topologies

    NASA Technical Reports Server (NTRS)

    Byrd, Gregory T.; Delagi, Bruce A.

    1987-01-01

    Choosing a multiprocessor interconnection topology may depend on high-level considerations, such as the intended application domain and the expected number of processors. It certainly depends on low-level implementation details, such as packaging and communications protocols. The authors first use rough measures of cost and performance to characterize several topologies. They then examine how implementation details can affect the realizable performance of a topology.

  6. Dedicated multiprocessor system for calculating Josephson-junction noise thermometer frequency variances at high speed

    SciTech Connect

    Cutkosky, R.D.

    1983-07-01

    A Josephson-junction noise thermometer produces a sequence of frequency readings from whose variations the temperature of the thermometer may be calculated. A preprocessor system has been constructed to collect the frequency readings delivered to an IEEE 488 bus by an ordinary counter operating at up to 1000 readings per second, perform the required calculations, and send summary information to a desk calculator or minicomputer on another 488 bus at a more convenient rate.

  7. Reader set encoding for directory of shared cache memory in multiprocessor system

    DOEpatents

    Ahn, Dnaiel; Ceze, Luis H.; Gara, Alan; Ohmacht, Martin; Xiaotong, Zhuang

    2014-06-10

    In a parallel processing system with speculative execution, conflict checking occurs in a directory lookup of a cache memory that is shared by all processors. In each case, the same physical memory address will map to the same set of that cache, no matter which processor originated that access. The directory includes a dynamic reader set encoding, indicating what speculative threads have read a particular line. This reader set encoding is used in conflict checking. A bitset encoding is used to specify particular threads that have read the line.

  8. Multiprocessor Neural Network in Healthcare.

    PubMed

    Godó, Zoltán Attila; Kiss, Gábor; Kocsis, Dénes

    2015-01-01

    A possible way of creating a multiprocessor artificial neural network is by the use of microcontrollers. The RISC processors' high performance and the large number of I/O ports mean they are greatly suitable for creating such a system. During our research, we wanted to see if it is possible to efficiently create interaction between the artifical neural network and the natural nervous system. To achieve as much analogy to the living nervous system as possible, we created a frequency-modulated analog connection between the units. Our system is connected to the living nervous system through 128 microelectrodes. Two-way communication is provided through A/D transformation, which is even capable of testing psychopharmacons. The microcontroller-based analog artificial neural network can play a great role in medical singal processing, such as ECG, EEG etc. PMID:26152990

  9. Shewanella oneidensis FabB: A β-ketoacyl-ACP Synthase That Works with C16:1-ACP

    PubMed Central

    Luo, Qixia; Li, Meng; Fu, Huihui; Meng, Qiu; Gao, Haichun

    2016-01-01

    It is established that Escherichia coli β-ketoacyl-ACP synthase (KAS) I (encoded by EcfabB) is the primary, if not exclusive, factor for elongation of the cis-3-decenoyl-ACP (C10:1-ACP) but not effective with C16:1- or longer-chain-ACPs. To test the extent to which these features apply to KAS I proteins in other species, in this study, we examined the physiological role of FabB in Shewanella oneidensis, an excellent model for researching type II fatty acid synthetic (FAS) system and its regulation. We showed that the loss of either FabA (the enzyme that introduces double bond) or FabB, in the absence of DesA which desaturizes C16 and C18 to generate respective C16:1 and C18:1, leads to a UFA auxotroph. However, fatty acid profiles of membrane phospholipid of the fabA and fabB mutants are significantly different, suggesting that FabB participates in steps beyond elongation of C10:1-ACP. Further analyses demonstrated that S. oneidensis FabB differs from EcFabB in that (i) it is not the only enzyme capable of catalyzing elongation of the cis-3-decenoyl-ACP produced by FabA, (ii) it plays a critical role in elongation of C16:1- and longer-chain-ACPs, and (iii) its overproduction is detrimental. PMID:27014246

  10. Hardware for a real-time multiprocessor simulator

    NASA Technical Reports Server (NTRS)

    Blech, R. A.; Arpasi, D. J.

    1984-01-01

    The hardware for a real time multiprocessor simulator (RTMPS) developed at the NASA Lewis Research Center is described. The RTMPS is a multiple microprocessor system used to investigate the application of parallel processing concepts to real time simulation. It is designed to provide flexible data exchange paths between processors by using off the shelf microcomputer boards and minimal customized interfacing. A dedicated operator interface allows easy setup of the simulator and quick interpreting of simulation data. Simulations for the RTMPS are coded in a NASA designed real time multiprocessor language (RTMPL). This language is high level and geared to the multiprocessor environment. A real time multiprocessor operating system (RTMPOS) has also been developed that provides a user friendly operator interface. The RTMPS and supporting software are currently operational and are being evaluated at Lewis. The results of this evaluation will be used to specify the design of an optimized parallel processing system for real time simulation of dynamic systems.

  11. Acyl-ACP thioesterases from castor (Ricinus communis L.): an enzymatic system appropriate for high rates of oil synthesis and accumulation.

    PubMed

    Sánchez-García, Alicia; Moreno-Pérez, Antonio J; Muro-Pastor, Alicia M; Salas, Joaquín J; Garcés, Rafael; Martínez-Force, Enrique

    2010-06-01

    Acyl-acyl carrier protein (ACP) thioesterases are enzymes that terminate the intraplastidial fatty acid synthesis in plants by hydrolyzing the acyl-ACP intermediates and releasing free fatty acids to be incorporated into glycerolipids. These enzymes are classified in two families, FatA and FatB, which differ in amino acid sequence and substrate specificity. In the present work, both FatA and FatB thioesterases were cloned, sequenced and characterized from castor (Ricinus communis) seeds, a crop of high interest in oleochemistry. Single copies of FatA and FatB were found in castor resulting to be closely related with those of Jatropha curcas. The corresponding mature proteins were heterologously expressed in Escherichia coli for biochemical characterization after purification, resulting in high catalytic efficiency of RcFatA on oleoyl-ACP and palmitoleoyl-ACP and high efficiencies of RcFatB for oleoyl-ACP and palmitoyl-ACP. The expression profile of these genes displayed the highest levels in expanding tissues that typically are very active in lipid biosynthesis such as developing seed endosperm and young expanding leaves. The contribution of these two enzymes to the synthesis of castor oil is discussed. PMID:20382402

  12. Multiprocessor performance modeling with ADAS

    NASA Technical Reports Server (NTRS)

    Hayes, Paul J.; Andrews, Asa M.

    1989-01-01

    A graph managing strategy referred to as the Algorithm to Architecture Mapping Model (ATAMM) appears useful for the time-optimized execution of application algorithm graphs in embedded multiprocessors and for the performance prediction of graph designs. This paper reports the modeling of ATAMM in the Architecture Design and Assessment System (ADAS) to make an independent verification of ATAMM's performance prediction capability and to provide a user framework for the evaluation of arbitrary algorithm graphs. Following an overview of ATAMM and its major functional rules are descriptions of the ADAS model of ATAMM, methods to enter an arbitrary graph into the model, and techniques to analyze the simulation results. The performance of a 7-node graph example is evaluated using the ADAS model and verifies the ATAMM concept by substantiating previously published performance results.

  13. Debugging in a multi-processor environment

    SciTech Connect

    Spann, J.M.

    1981-09-29

    The Supervisory Control and Diagnostic System (SCDS) for the Mirror Fusion Test Facility (MFTF) consists of nine 32-bit minicomputers arranged in a tightly coupled distributed computer system utilizing a share memory as the data exchange medium. Debugging of more than one program in the multi-processor environment is a difficult process. This paper describes what new tools were developed and how the testing of software is performed in the SCDS for the MFTF project.

  14. Evict on write, a management strategy for a prefetch unit and/or first level cache in a multiprocessor system with speculative execution

    DOEpatents

    Gara, Alan; Ohmacht, Martin

    2014-09-16

    In a multiprocessor system with at least two levels of cache, a speculative thread may run on a core processor in parallel with other threads. When the thread seeks to do a write to main memory, this access is to be written through the first level cache to the second level cache. After the write though, the corresponding line is deleted from the first level cache and/or prefetch unit, so that any further accesses to the same location in main memory have to be retrieved from the second level cache. The second level cache keeps track of multiple versions of data, where more than one speculative thread is running in parallel, while the first level cache does not have any of the versions during speculation. A switch allows choosing between modes of operation of a speculation blind first level cache.

  15. Aqueous Molecular Dynamics Simulations of the M. tuberculosis Enoyl-ACP Reductase-NADH System and Its Complex with a Substrate Mimic or Diphenyl Ethers Inhibitors

    PubMed Central

    da Silva Lima, Camilo Henrique; de Alencastro, Ricardo Bicca; Kaiser, Carlos Roland; de Souza, Marcus Vinícius Nora; Rodrigues, Carlos Rangel; Albuquerque, Magaly Girão

    2015-01-01

    Molecular dynamics (MD) simulations of 12 aqueous systems of the NADH-dependent enoyl-ACP reductase from Mycobacterium tuberculosis (InhA) were carried out for up to 20–40 ns using the GROMACS 4.5 package. Simulations of the holoenzyme, holoenzyme-substrate, and 10 holoenzyme-inhibitor complexes were conducted in order to gain more insight about the secondary structure motifs of the InhA substrate-binding pocket. We monitored the lifetime of the main intermolecular interactions: hydrogen bonds and hydrophobic contacts. Our MD simulations demonstrate the importance of evaluating the conformational changes that occur close to the active site of the enzyme-cofactor complex before and after binding of the ligand and the influence of the water molecules. Moreover, the protein-inhibitor total steric (ELJ) and electrostatic (EC) interaction energies, related to Gly96 and Tyr158, are able to explain 80% of the biological response variance according to the best linear equation, pKi = 7.772 − 0.1885 × Gly96 + 0.0517 × Tyr158 (R2 = 0.80; n = 10), where interactions with Gly96, mainly electrostatic, increase the biological response, while those with Tyr158 decrease. These results will help to understand the structure-activity relationships and to design new and more potent anti-TB drugs. PMID:26457706

  16. Queueing analysis of a canonical model of real-time multiprocessors

    NASA Technical Reports Server (NTRS)

    Krishna, C. M.; Shin, K. G.

    1983-01-01

    A logical classification of multiprocessor structures from the point of view of control applications is presented. A computation of the response time distribution for a canonical model of a real time multiprocessor is presented. The multiprocessor is approximated by a blocking model. Two separate models are derived: one created from the system's point of view, and the other from the point of view of an incoming task.

  17. The fault-tolerant multiprocessor computer

    NASA Technical Reports Server (NTRS)

    Smith, T. B., III (Editor); Lala, J. H. (Editor); Goldberg, J. (Editor); Kautz, W. H. (Editor); Melliar-Smith, P. M. (Editor); Green, M. W. (Editor); Levitt, K. N. (Editor); Schwartz, R. L. (Editor); Weinstock, C. B. (Editor); Palumbo, D. L. (Editor)

    1986-01-01

    The development and evaluation of fault-tolerant computer architectures and software-implemented fault tolerance (SIFT) for use in advanced NASA vehicles and potentially in flight-control systems are described in a collection of previously published reports prepared for NASA. Topics addressed include the principles of fault-tolerant multiprocessor (FTMP) operation; processor and slave regional designs; FTMP executive, facilities, acceptance-test/diagnostic, applications, and support software; FTM reliability and availability models; SIFT hardware design; and SIFT validation and verification.

  18. Modified acyl-ACP desaturase

    DOEpatents

    Cahoon, Edgar B.; Shanklin, John; Lindgvist, Ylva; Schneider, Gunter

    1998-01-06

    Disclosed is a methods for modifying the chain length and double bond positional specificities of a soluble plant fatty acid desaturase. More specifically, the method involves modifying amino acid contact residues in the substrate binding channel of the soluble fatty acid desaturase which contact the fatty acid. Specifically disclosed is the modification of an acyl-ACP desaturase. Amino acid contact residues which lie within the substrate binding channel are identified, and subsequently replaced with different residues to effect the modification of activity.

  19. Modified Acyl-ACP desaturase

    DOEpatents

    Cahoon, Edgar B.; Shanklin, John; Lindqvist, Ylva; Schneider, Gunter

    1999-03-30

    Disclosed is a method for modifying the chain length and double bond positional specificities of a soluble plant fatty acid desaturase. More specifically, the method involves modifying amino acid contact residues in the substrate binding channel of the soluble fatty acid desaturase which contact the fatty acid. Specifically disclosed is the modification of an acyl-ACP desaturase. Amino acid contact residues which lie within the substrate binding channel are identified, and subsequently replaced with different residues to effect the modification of activity.

  20. Mannose 6 Dephosphorylation of Lysosomal Proteins Mediated by Acid Phosphatases Acp2 and Acp5

    PubMed Central

    Makrypidi, Georgia; Damme, Markus; Müller-Loennies, Sven; Trusch, Maria; Schmidt, Bernhard; Schlüter, Hartmut; Heeren, Joerg; Lübke, Torben; Saftig, Paul

    2012-01-01

    Mannose 6-phosphate (Man6P) residues represent a recognition signal required for efficient receptor-dependent transport of soluble lysosomal proteins to lysosomes. Upon arrival, the proteins are rapidly dephosphorylated. We used mice deficient for the lysosomal acid phosphatase Acp2 or Acp5 or lacking both phosphatases (Acp2/Acp5−/−) to examine their role in dephosphorylation of Man6P-containing proteins. Two-dimensional (2D) Man6P immunoblot analyses of tyloxapol-purified lysosomal fractions revealed an important role of Acp5 acting in concert with Acp2 for complete dephosphorylation of lysosomal proteins. The most abundant lysosomal substrates of Acp2 and Acp5 were identified by Man6P affinity chromatography and mass spectrometry. Depending on the presence of Acp2 or Acp5, the isoelectric point of the lysosomal cholesterol-binding protein Npc2 ranged between 7.0 and 5.4 and may thus regulate its interaction with negatively charged lysosomal membranes at acidic pH. Correspondingly, unesterified cholesterol was found to accumulate in lysosomes of cultured hepatocytes of Acp2/Acp5−/− mice. The data demonstrate that dephosphorylation of Man6P-containing lysosomal proteins requires the concerted action of Acp2 and Acp5 and is needed for hydrolysis and removal of degradation products. PMID:22158965

  1. Linear solvers on multiprocessor machines

    SciTech Connect

    Kalogerakis, M.A.

    1986-01-01

    Two new methods are introduced for the parallel solution of banded linear systems on multiprocessor machines. Moreover, some new techniques are obtained as variations of the two methods that are applicable to special instances of the problem. Comparisons with the best known methods are performed, from which it is concluded that the two methods are superior, while their variations for special instances are, in general, competitive and in some cases best. In the process, some new results on the parallel prefix problem are obtained and a new design for this problem is presented that is suitable for VLSI implementation. Furthermore, a general model is introduced for the analysis and classification of methods that are based on row transformations of matrices. It is seen that most known methods are included in this model. It is demonstrated that this model may be used as a basis for the analysis as well as the generation of important aspects of those methods, such as their arithmetic complexity and interprocessor communication requirements.

  2. Modified Acyl-ACP desaturase

    DOEpatents

    Cahoon, E.B.; Shanklin, J.; Lindqvist, Y.; Schneider, G.

    1999-03-30

    Disclosed is a method for modifying the chain length and double bond positional specificities of a soluble plant fatty acid desaturase. More specifically, the method involves modifying amino acid contact residues in the substrate binding channel of the soluble fatty acid desaturase which contact the fatty acid. Specifically disclosed is the modification of an acyl-ACP desaturase. Amino acid contact residues which lie within the substrate binding channel are identified, and subsequently replaced with different residues to effect the modification of activity. 2 figs.

  3. Modified acyl-ACP desaturase

    DOEpatents

    Cahoon, E.B.; Shanklin, J.; Lindgvist, Y.; Schneider, G.

    1998-01-06

    Disclosed is a method for modifying the chain length and double bond positional specificities of a soluble plant fatty acid desaturase. More specifically, the method involves modifying amino acid contact residues in the substrate binding channel of the soluble fatty acid desaturase which contact the fatty acid. Specifically disclosed is the modification of an acyl-ACP desaturase. Amino acid contact residues which lie within the substrate binding channel are identified, and subsequently replaced with different residues to effect the modification of activity. 1 fig.

  4. Matrix factorization on a hypercube multiprocessor

    SciTech Connect

    Geist, G.A.; Heath, M.T.

    1985-08-01

    This paper is concerned with parallel algorithms for matrix factorization on distributed-memory, message-passing multiprocessors, with special emphasis on the hypercube. Both Cholesky factorization of symmetric positive definite matrices and LU factorization of nonsymmetric matrices using partial pivoting are considered. The use of the resulting triangular factors to solve systems of linear equations by forward and back substitutions is also considered. Efficiencies of various parallel computational approaches are compared in terms of empirical results obtained on an Intel iPSC hypercube. 19 refs., 6 figs., 2 tabs.

  5. Real-Time Multiprocessor Programming Language (RTMPL) user's manual

    NASA Technical Reports Server (NTRS)

    Arpasi, D. J.

    1985-01-01

    A real-time multiprocessor programming language (RTMPL) has been developed to provide for high-order programming of real-time simulations on systems of distributed computers. RTMPL is a structured, engineering-oriented language. The RTMPL utility supports a variety of multiprocessor configurations and types by generating assembly language programs according to user-specified targeting information. Many programming functions are assumed by the utility (e.g., data transfer and scaling) to reduce the programming chore. This manual describes RTMPL from a user's viewpoint. Source generation, applications, utility operation, and utility output are detailed. An example simulation is generated to illustrate many RTMPL features.

  6. A Community-oriented CEOS Atmospheric Composition Portal (ACP)

    NASA Astrophysics Data System (ADS)

    Bernonville, S.; Goussev, O.; Falke, S.; Lindsay, F.; Lynnes, C. S.; Yang, W.; Zhao, P.; Johnson, J.

    2012-04-01

    The Atmospheric Composition Constellation (ACC) and the Workgroup for Information Systems and Services (WGISS) within the Committee on Earth Observation Satellites (CEOS) is developing a portal to support interoperability among the atmospheric composition research and applications communities. The CEOS Atmospheric Composition Portal (ACP) is defining approaches for providing data access, tools and contextual guidance for an international suite of remote sensing datasets. An initial prototype provides access to data services and analysis tools hosted by the World Data Center for Remote Sensing of the Atmosphere (WDC-RSAT), NASA's Goddard Earth Sciences Data and Information Services Center (GES DISC) and DataFed. Distributed access to data is implemented via interoperability standards, including the Open Geospatial Consortium's (OGC) Web Map Service (WMS) and Web Coverage Service (WCS). A fundamental aspect to the design, implementation and evolution of the ACP is community collaboration. The portal is intended as a community resource that is created through collaboration across remotely sensed atmospheric composition data organizations and used by a variety of groups across the climate, air quality, and stratospheric ozone domains. The implementation of interoperability standards in the ACP has involved coordination on identifying the most applicable standards and the definition of community-specific conventions to ensure consistent adoption of standards. This presentation includes an overview of the ACP, its community oriented approach, and use of community-conventions in achieving standards-based interoperability.

  7. Fault tree models for fault tolerant hypercube multiprocessors

    NASA Technical Reports Server (NTRS)

    Boyd, Mark A.; Tuazon, Jezus O.

    1991-01-01

    Three candidate fault tolerant hypercube architectures are modeled, their reliability analyses are compared, and the resulting implications of these methods of incorporating fault tolerance into hypercube multiprocessors are discussed. In the course of performing the reliability analyses, the use of HARP and fault trees in modeling sequence dependent system behaviors is demonstrated.

  8. A simple modern correctness condition for a space-based high-performance multiprocessor

    NASA Technical Reports Server (NTRS)

    Probst, David K.; Li, Hon F.

    1992-01-01

    A number of U.S. national programs, including space-based detection of ballistic missile launches, envisage putting significant computing power into space. Given sufficient progress in low-power VLSI, multichip-module packaging and liquid-cooling technologies, we will see design of high-performance multiprocessors for individual satellites. In very high speed implementations, performance depends critically on tolerating large latencies in interprocessor communication; without latency tolerance, performance is limited by the vastly differing time scales in processor and data-memory modules, including interconnect times. The modern approach to tolerating remote-communication cost in scalable, shared-memory multiprocessors is to use a multithreaded architecture, and alter the semantics of shared memory slightly, at the price of forcing the programmer either to reason about program correctness in a relaxed consistency model or to agree to program in a constrained style. The literature on multiprocessor correctness conditions has become increasingly complex, and sometimes confusing, which may hinder its practical application. We propose a simple modern correctness condition for a high-performance, shared-memory multiprocessor; the correctness condition is based on a simple interface between the multiprocessor architecture and a high-performance, shared-memory multiprocessor; the correctness condition is based on a simple interface between the multiprocessor architecture and the parallel programming system.

  9. Kendall Square multiprocessor: Early experiences and performance

    SciTech Connect

    Dunigan, T.H.

    1992-04-01

    Initial performance results and early experiences are reported for the Kendall Square Research multiprocessor. The basic architecture of the shared-memory multiprocessor is described, and computational and I/O performance is measured for both serial and parallel programs. Experiences in porting various applications are described.

  10. Multiprocessor computer overset grid method and apparatus

    DOEpatents

    Barnette, Daniel W.; Ober, Curtis C.

    2003-01-01

    A multiprocessor computer overset grid method and apparatus comprises associating points in each overset grid with processors and using mapped interpolation transformations to communicate intermediate values between processors assigned base and target points of the interpolation transformations. The method allows a multiprocessor computer to operate with effective load balance on overset grid applications.

  11. Improved multiprocessor garbage collection algorithms

    SciTech Connect

    Newman, I.A.; Stallard, R.P.; Woodward, M.C.

    1983-01-01

    Outlines the results of an investigation of existing multiprocessor garbage collection algorithms and introduces two new algorithms which significantly improve some aspects of the performance of their predecessors. The two algorithms arise from different starting assumptions. One considers the case where the algorithm will terminate successfully whatever list structure is being processed and assumes that the extra data space should be minimised. The other seeks a very fast garbage collection time for list structures that do not contain loops. Results of both theoretical and experimental investigations are given to demonstrate the efficacy of the algorithms. 7 references.

  12. Parallel processing and medium-scale multiprocessors

    SciTech Connect

    Wouk, A.

    1989-01-01

    For some time, the community interested in large-scale scientific computing has been attempting to come to terms with parallel computation using a number of processors sufficient to make their concurrent utilization interesting, challenging, and, in the long run, beneficial. Unexpected consequences of parallelization have been discovered. It is possible to obtain reduced performance, both relative and absolute, from an increased number of processors, as a result of inappropriate use of resources in a multiprocessor environment. This exemplifies one of the paradoxes which result from our cultural bias towards sequential thought processes. As a consequence there is a bias for sequential styles of program development in a multiprocessor environment. The authors have learned that the problem of automatic optimization in compilation of parallel programs is computationally hard. Early hopes that automatic, optimal parallelization of sequentially conceived programs would be as achievable as earlier automatic vectorization had been, have been dashed. The authors lack the insights and folklore which are needed to develop useful methodologies and heuristics in the area of parallel computation. The authors are embarked on a voyage of exploration of this new territory, and the work described in this volume can provide helpful guidance. The authors have to explore fully the differences between distributed memory systems, shared memory systems, and combinations, as well as the relative applicability of SIMD and MIMD architectures. Based on the information obtained in such exploration, useful steps towards efficient utilization of many processors should become possible. This paper covers several areas: systems programming, parallel/language/programming systems, and applications programming.

  13. NoC emulation framework based on Arteris NoC solution for multiprocessor system-on-chip

    NASA Astrophysics Data System (ADS)

    Mori, José A.; Tobajas, Félix; de Armas, Valentín; Sarmiento, Roberto

    2011-05-01

    The growth of complexity and the requirements of on-chip technologies create the need for new architectures which generate solutions representing a compromise between complexity and power consumption, and Quality of Service (QoS) of the communications between the cores of a System-on-Chip (SoC). Network-on-Chip (NoC) arises as a solution to implement efficient interconnections in SoC. This new technology, due to its complexity, creates the need of specialized engineers who can design the intricate circuits that NoC requires. It is possible to reduce those specialization needs by using CAD tools. In this paper, one of this tools, called Arteris NoC Solution, is used for developing the proposed framework for NoC emulation. This software includes three different tools: NoCexplorer, for high-level simulation of an abstract model of the NoC, NoCcompiler, in which the NoC is defined and generated in HDL language, and NoCverifier, which performs simulations of the HDL code. Furthermore, a validation and characterization infrastructure was developed for the created NoC, which can be completely emulated in FPGA. This environment is composed by OCP traffic generators and receptors, which also can perform measurements over the created traffic, and a store and communication module, which is responsible for storing the results obtained from the emulation of the entire system in the FPGA, and send it to a PC. Once the data is stored in the PC, statistical analyses are performed, including a comparison of mean latency from high level simulations, RTL simulations and FPGA emulations. The analysis of the results is obtained from three scenarios with different NoC topologies for the same SoC design.

  14. Parallel language support on shared memory multiprocessors

    SciTech Connect

    Sah, A.

    1991-01-01

    The study of general purpose parallel computing requires efficient and inexpensive platforms for parallel program execution. This helps in ascertaining tradeoff choices between hardware complexity and software solutions for massively parallel systems design. In this paper, the authors present an implementation of an efficient parallel execution model on shared memory multiprocessors based on a Threaded Abstract Machine. The authors discuss a k-way generalized locking strategy suitable for our model. The authors study the performance gains obtained by a queuing strategy which uses multiple gueues with reduced access contention. The authors also present performance models in shared memory machines, related to lock contention and serialization in shared memory allocation. A bin-based memory management technique which reduces the serialization is presented. These issues are critical for obtaining an efficient parallel execution environment.

  15. The EPSILON-2 multiprocessor system

    SciTech Connect

    Grafe, V.G.; Hoch, J.E. )

    1990-12-01

    This paper reports on Epsilon-2 which is a general purpose parallel computer architecture that addresses the twin goals of high performance and programmability. Epsilon-2 implements a hybrid computation model that combines the fine-grain parallelism of dataflow computing with the sequential efficiency characteristic of von Neumann computing. It provides instruction-level synchronization, single-cycle context switches, and RISC-like sequential execution. The general parallel computing model and the architecture of Epsilon-2 are described. A sample code is also presented to illustrate Epsilon-2's operation.

  16. Acyl-ACP Substrate Recognition in Burkholderia mallei BmaI1 Acyl-Homoserine Lactone Synthase

    PubMed Central

    2015-01-01

    The acyl-homoserine lactone (AHL) autoinducer mediated quorum sensing regulates virulence in several pathogenic bacteria. The hallmark of an efficient quorum sensing system relies on the tight specificity in the signal generated by each bacterium. Since AHL signal specificity is derived from the acyl-chain of the acyl-ACP (ACP = acyl carrier protein) substrate, AHL synthase enzymes must recognize and react with the native acyl-ACP with high catalytic efficiency while keeping reaction rates with non-native acyl-ACPs low. The mechanism of acyl-ACP substrate recognition in these enzymes, however, remains elusive. In this study, we investigated differences in catalytic efficiencies for shorter and longer chain acyl-ACP substrates reacting with an octanoyl-homoserine lactone synthase Burkholderia mallei BmaI1. With the exception of two-carbon shorter hexanoyl-ACP, the catalytic efficiencies of butyryl-ACP, decanoyl-ACP, and octanoyl-CoA reacting with BmaI1 decreased by greater than 20-fold compared to the native octanoyl-ACP substrate. Furthermore, we also noticed kinetic cooperativity when BmaI1 reacted with non-native acyl-donor substrates. Our kinetic data suggest that non-native acyl-ACP substrates are unable to form a stable and productive BmaI1·acyl-ACP·SAM ternary complex and are thus effectively discriminated by the enzyme. These results offer insights into the molecular basis of substrate recognition for the BmaI1 enzyme. PMID:25215658

  17. Fault-free performance validation of fault-tolerant multiprocessors

    NASA Technical Reports Server (NTRS)

    Czeck, Edward W.; Feather, Frank E.; Grizzaffi, Ann Marie; Segall, Zary Z.; Siewiorek, Daniel P.

    1987-01-01

    A validation methodology for testing the performance of fault-tolerant computer systems was developed and applied to the Fault-Tolerant Multiprocessor (FTMP) at NASA-Langley's AIRLAB facility. This methodology was claimed to be general enough to apply to any ultrareliable computer system. The goal of this research was to extend the validation methodology and to demonstrate the robustness of the validation methodology by its more extensive application to NASA's Fault-Tolerant Multiprocessor System (FTMP) and to the Software Implemented Fault-Tolerance (SIFT) Computer System. Furthermore, the performance of these two multiprocessors was compared by conducting similar experiments. An analysis of the results shows high level language instruction execution times for both SIFT and FTMP were consistent and predictable, with SIFT having greater throughput. At the operating system level, FTMP consumes 60% of the throughput for its real-time dispatcher and 5% on fault-handling tasks. In contrast, SIFT consumes 16% of its throughput for the dispatcher, but consumes 66% in fault-handling software overhead.

  18. Modelling parallel programs and multiprocessor architectures with AXE

    NASA Technical Reports Server (NTRS)

    Yan, Jerry C.; Fineman, Charles E.

    1991-01-01

    AXE, An Experimental Environment for Parallel Systems, was designed to model and simulate for parallel systems at the process level. It provides an integrated environment for specifying computation models, multiprocessor architectures, data collection, and performance visualization. AXE is being used at NASA-Ames for developing resource management strategies, parallel problem formulation, multiprocessor architectures, and operating system issues related to the High Performance Computing and Communications Program. AXE's simple, structured user-interface enables the user to model parallel programs and machines precisely and efficiently. Its quick turn-around time keeps the user interested and productive. AXE models multicomputers. The user may easily modify various architectural parameters including the number of sites, connection topologies, and overhead for operating system activities. Parallel computations in AXE are represented as collections of autonomous computing objects known as players. Their use and behavior is described. Performance data of the multiprocessor model can be observed on a color screen. These include CPU and message routing bottlenecks, and the dynamic status of the software.

  19. ATAMM enhancement and multiprocessor performance evaluation

    NASA Technical Reports Server (NTRS)

    Stoughton, John W.; Mielke, Roland R.; Som, Sukhamoy; Obando, Rodrigo; Malekpour, Mahyar R.; Jones, Robert L., III; Mandala, Brij Mohan V.

    1991-01-01

    ATAMM (Algorithm To Architecture Mapping Model) enhancement and multiprocessor performance evaluation is discussed. The following topics are included: the ATAMM model; ATAMM enhancement; ADM (Advanced Development Model) implementation of ATAMM; and ATAMM support tools.

  20. Modeling and measurement of fault-tolerant multiprocessors

    NASA Technical Reports Server (NTRS)

    Shin, K. G.; Woodbury, M. H.; Lee, Y. H.

    1985-01-01

    The workload effects on computer performance are addressed first for a highly reliable unibus multiprocessor used in real-time control. As an approach to studing these effects, a modified Stochastic Petri Net (SPN) is used to describe the synchronous operation of the multiprocessor system. From this model the vital components affecting performance can be determined. However, because of the complexity in solving the modified SPN, a simpler model, i.e., a closed priority queuing network, is constructed that represents the same critical aspects. The use of this model for a specific application requires the partitioning of the workload into job classes. It is shown that the steady state solution of the queuing model directly produces useful results. The use of this model in evaluating an existing system, the Fault Tolerant Multiprocessor (FTMP) at the NASA AIRLAB, is outlined with some experimental results. Also addressed is the technique of measuring fault latency, an important microscopic system parameter. Most related works have assumed no or a negligible fault latency and then performed approximate analyses. To eliminate this deficiency, a new methodology for indirectly measuring fault latency is presented.

  1. FTMP - A highly reliable Fault-Tolerant Multiprocessor for aircraft

    NASA Technical Reports Server (NTRS)

    Hopkins, A. L., Jr.; Smith, T. B., III; Lala, J. H.

    1978-01-01

    The FTMP (Fault-Tolerant Multiprocessor) is a complex multiprocessor computer that employs a form of redundancy related to systems considered by Mathur (1971), in which each major module can substitute for any other module of the same type. Despite the conceptual simplicity of the redundancy form, the implementation has many intricacies owing partly to the low target failure rate, and partly to the difficulty of eliminating single-fault vulnerability. An extensive analysis of the computer through the use of such modeling techniques as Markov processes and combinatorial mathematics shows that for random hard faults the computer can meet its requirements. It is also shown that the maintenance scheduled at intervals of 200 hr or more can be adequate most of the time.

  2. 7 CFR 701.44 - Agricultural Conservation Program (ACP) contracts.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... be subject to, the regulations for ACP contracts and the ACP program that were contained in the 7 CFR... 7 Agriculture 7 2012-01-01 2012-01-01 false Agricultural Conservation Program (ACP) contracts. 701... AGENCY, DEPARTMENT OF AGRICULTURE AGRICULTURAL CONSERVATION PROGRAM EMERGENCY CONSERVATION...

  3. 7 CFR 701.44 - Agricultural Conservation Program (ACP) contracts.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... be subject to, the regulations for ACP contracts and the ACP program that were contained in the 7 CFR... 7 Agriculture 7 2014-01-01 2014-01-01 false Agricultural Conservation Program (ACP) contracts. 701... AGENCY, DEPARTMENT OF AGRICULTURE AGRICULTURAL CONSERVATION PROGRAM EMERGENCY CONSERVATION...

  4. 7 CFR 701.44 - Agricultural Conservation Program (ACP) contracts.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... be subject to, the regulations for ACP contracts and the ACP program that were contained in the 7 CFR... 7 Agriculture 7 2011-01-01 2011-01-01 false Agricultural Conservation Program (ACP) contracts. 701... AGENCY, DEPARTMENT OF AGRICULTURE AGRICULTURAL CONSERVATION PROGRAM EMERGENCY CONSERVATION...

  5. 7 CFR 701.44 - Agricultural Conservation Program (ACP) contracts.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... be subject to, the regulations for ACP contracts and the ACP program that were contained in the 7 CFR... 7 Agriculture 7 2013-01-01 2013-01-01 false Agricultural Conservation Program (ACP) contracts. 701... AGENCY, DEPARTMENT OF AGRICULTURE AGRICULTURAL CONSERVATION PROGRAM EMERGENCY CONSERVATION...

  6. 7 CFR 701.44 - Agricultural Conservation Program (ACP) contracts.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... regulations for ACP contracts and the ACP program that were contained in the 7 CFR, parts 700 to 899, edition... 7 Agriculture 7 2010-01-01 2010-01-01 false Agricultural Conservation Program (ACP) contracts. 701... AGENCY, DEPARTMENT OF AGRICULTURE AGRICULTURAL CONSERVATION PROGRAM EMERGENCY CONSERVATION PROGRAM...

  7. Interaction between infectious diseases and personality traits: ACP1*C as a potential mediator.

    PubMed

    Napolioni, Valerio; Murray, Damian R; Comings, David E; Peters, Warren R; Gade-Andavolu, Radhika; MacMurray, James

    2014-08-01

    In geographical regions characterized by high pathogen prevalence, it has been shown that human populations tend to be characterized by lower levels of extraversion (E) and openness to experience (OtE). According to the "behavioral immune system" hypothesis, the reduction of extraversion and openness levels represents a behavioral defense against infections. Like the 'classical' immune system, the "behavioral immune system" could also be shaped by its underlying genetic background. Previous studies have shown that the *C allele of the ACP1 gene confers increased susceptibility to infectious/parasitic diseases. We hypothesized that carriers of the ACP1*C allele should likewise be associated with reduced E and OtE. We tested this hypothesis using two samples comprised of 153 students from Southern California (Group 1), and 162 female subjects recruited from an executive health program (Group 2), genotyped for ACP1 polymorphism and evaluated by the NEO Five-Factor Inventory (NEO-FFI). ACP1 was significantly associated with E: we found that carriers of ACP1*C showed reduced scores for E (Group 1: β=-4.263, P=0.027; Group 2: β=-8.315, P=0.003; Group 1+Group 2: β=-5.366, P=0.001). Across groups, ACP1 was only marginally associated with OtE. In conclusion, the present study found that the ACP1*C allele, previously associated with an increased vulnerability to infectious/parasitic diseases may also be able to shape behavioral immune defenses by interaction with the level of E. PMID:24933463

  8. FTMP (Fault Tolerant Multiprocessor) programmer's manual

    NASA Technical Reports Server (NTRS)

    Feather, F. E.; Liceaga, C. A.; Padilla, P. A.

    1986-01-01

    The Fault Tolerant Multiprocessor (FTMP) computer system was constructed using the Rockwell/Collins CAPS-6 processor. It is installed in the Avionics Integration Research Laboratory (AIRLAB) of NASA Langley Research Center. It is hosted by AIRLAB's System 10, a VAX 11/750, for the loading of programs and experimentation. The FTMP support software includes a cross compiler for a high level language called Automated Engineering Design (AED) System, an assembler for the CAPS-6 processor assembly language, and a linker. Access to this support software is through an automated remote access facility on the VAX which relieves the user of the burden of learning how to use the IBM 4381. This manual is a compilation of information about the FTMP support environment. It explains the FTMP software and support environment along many of the finer points of running programs on FTMP. This will be helpful to the researcher trying to run an experiment on FTMP and even to the person probing FTMP with fault injections. Much of the information in this manual can be found in other sources; we are only attempting to bring together the basic points in a single source. If the reader should need points clarified, there is a list of support documentation in the back of this manual.

  9. Iterative algorithms for tridiagonal matrices on a WSI-multiprocessor

    NASA Astrophysics Data System (ADS)

    Gajski, D. D.; Sameh, A. H.; Wisniewski, J. A.

    With the rapid advances in semiconductor technology, the construction of Wafer Scale Integration (WSI)-multiprocessors consisting of a large number of processors is now feasible. The implementation of some basis linear algebra algorithms on such multiprocessors is illustrated.

  10. Mycolic acid biosynthesis and enzymic characterization of the beta-ketoacyl-ACP synthase A-condensing enzyme from Mycobacterium tuberculosis.

    PubMed

    Kremer, Laurent; Dover, Lynn G; Carrère, Séverine; Nampoothiri, K Madhavan; Lesjean, Sarah; Brown, Alistair K; Brennan, Patrick J; Minnikin, David E; Locht, Camille; Besra, Gurdyal S

    2002-06-01

    Mycolic acids consist of long-chain alpha-alkyl-beta-hydroxy fatty acids that are produced by successive rounds of elongation catalysed by a type II fatty acid synthase (FAS-II). A key feature in the elongation process is the condensation of a two-carbon unit from malonyl-acyl-carrier protein (ACP) to a growing acyl-ACP chain catalysed by a beta-ketoacyl-ACP synthase (Kas). In the present study, we provide evidence that kasA from Mycobacterium tuberculosis encodes an enzyme that elongates in vivo the meromycolate chain, in both Mycobacterium smegmatis and Mycobacterium chelonae. We demonstrate that KasA belongs to the FAS-II system, which utilizes primarily palmitoyl-ACP rather than short-chain acyl-ACP primers. Furthermore, in an in vitro condensing assay using purified recombinant KasA, palmitoyl-AcpM and malonyl-AcpM, KasA was found to express Kas activity. Also, mutated KasA proteins, with mutation of Cys(171), His(311), Lys(340) and His(345) to Ala abrogated the condensation activity of KasA in vitro completely. Finally, purified KasA was highly sensitive to cerulenin, a well-known inhibitor of Kas, which may lead to the development of novel anti-mycobacterial drugs targeting KasA. PMID:12023885

  11. Validation of a fault-tolerant multiprocessor: Baseline experiments and workload implementation

    NASA Technical Reports Server (NTRS)

    Feather, Frank; Siewiorek, Daniel; Segall, Zary

    1985-01-01

    In the future, aircraft must employ highly reliable multiprocessors in order to achieve flight safety. Such computers must be experimentally validated before they are deployed. This project outlines a methodology for validating reliable multiprocessors. The methodology begins with baseline experiments, which tests a single phenomenon. As experiments progress, tools for performance testing are developed. The methodology is used, in part, on the Fault Tolerant Multiprocessor (FTMP) at NASA-Langley's AIRLAB facility. Experiments are designed to evaluate the fault-free performance of the system. Presented are the results of interrupt baseline experiments performed on FTMP. Interrupt causing exception conditions were tested, and several were found to have unimplemented interrupt handling software while one had an unimplemented interrupt vector. A synthetic workload model for realtime multiprocessors is then developed as an application level performance analysis tool. Details of the workload implementation and calibration are presented. Both the experimental methodology and the synthetic workload model are general enough to be applicable to reliable multiprocessors beside FTMP.

  12. Development and evaluation of a fault-tolerant multiprocessor (FTMP) computer. Volume 1: FTMP principles of operation

    NASA Technical Reports Server (NTRS)

    Smith, T. B., Jr.; Lala, J. H.

    1983-01-01

    The basic organization of the fault tolerant multiprocessor, (FTMP) is that of a general purpose homogeneous multiprocessor. Three processors operate on a shared system (memory and I/O) bus. Replication and tight synchronization of all elements and hardware voting is employed to detect and correct any single fault. Reconfiguration is then employed to repair a fault. Multiple faults may be tolerated as a sequence of single faults with repair between fault occurrences.

  13. Simulating an aerospace multiprocessor. [for space guidance computers

    NASA Technical Reports Server (NTRS)

    Mallach, E. G.

    1976-01-01

    The paper describes a simulator which was used to evaluate the architecture of an aerospace multiprocessor. The simulator models interactions among the processors, memories, the central data bus, and a possible 'job stack'. Special features of the simulator are discussed, including the use of explicitly coded and individually distinguishable 'job models' instead of a statistically defined 'job mix' and a specialized Job Model Definition Language to automate the detailed coding of the models. Some results are presented which show that when the simulator was employed in conjunction with queuing theory and Markov-process analysis, more insight into system behavior was obtained than would have been with any one technique alone.

  14. A combined PLC and CPU approach to multiprocessor control

    SciTech Connect

    Harris, J.J.; Broesch, J.D.; Coon, R.M.

    1995-10-01

    A sophisticated multiprocessor control system has been developed for use in the E-Power Supply System Integrated Control (EPSSIC) on the DIII-D tokamak. EPSSIC provides control and interlocks for the ohmic heating coil power supply and its associated systems. Of particular interest is the architecture of this system: both a Programmable Logic Controller (PLC) and a Central Processor Unit (CPU) have been combined on a standard VME bus. The PLC and CPU input and output signals are routed through signal conditioning modules, which provide the necessary voltage and ground isolation. Additionally these modules adapt the signal levels to that of the VME I/O boards. One set of I/O signals is shared between the two processors. The resulting multiprocessor system provides a number of advantages: redundant operation for mission critical situations, flexible communications using conventional TCP/IP protocols, the simplicity of ladder logic programming for the majority of the control code, and an easily maintained and expandable non-proprietary system.

  15. Application of the Payload Data Processing and Storage System to MOSREM Multi-Processor On-Board System for Robotic Exploration Missions

    NASA Astrophysics Data System (ADS)

    Jameux, D.

    (TOS-MMA) section of the European Space Agency. Spacecraft autonomy requires massive processing power that is not available in nowadays space-qualified processors, nor will be for some time. On the other INTRODUCTION hand, leading civil/military processors and processing modules, though providing the numerical power needed To fulfil the growing needs of processing high for autonomy, cannot work reliably in the harsh space quantities of data on-board satellites, payload engineers environment. have come to a common approach. They design sets of data acquisition, storing and processing elements for on- ESA has defined in co-operation with Industry a board applications that form what ESA calls a Payload reference architecture for payload processing that Data Processing and Storage System (PDPSS). decomposes the global payload data processing system in nodes interconnected by high-speed serial links (SpaceWire). This architecture may easily integrate heterogeneous processors, thus providing the ideal framework for combining the environmental ruggedness of space processors (e.g. ERC32) with the shear computing power of industrial processors. This paper presents ESA's near future efforts for the development of an environmentally sound and high performance on-board computer system, composed of COTS and space-qualified hardware, in which the desired characteristics (high computing power and high Figure

  16. Efficient partitioning and assignment on programs for multiprocessor execution

    NASA Technical Reports Server (NTRS)

    Standley, Hilda M.

    1993-01-01

    The general problem studied is that of segmenting or partitioning programs for distribution across a multiprocessor system. Efficient partitioning and the assignment of program elements are of great importance since the time consumed in this overhead activity may easily dominate the computation, effectively eliminating any gains made by the use of the parallelism. In this study, the partitioning of sequentially structured programs (written in FORTRAN) is evaluated. Heuristics, developed for similar applications are examined. Finally, a model for queueing networks with finite queues is developed which may be used to analyze multiprocessor system architectures with a shared memory approach to the problem of partitioning. The properties of sequentially written programs form obstacles to large scale (at the procedure or subroutine level) parallelization. Data dependencies of even the minutest nature, reflecting the sequential development of the program, severely limit parallelism. The design of heuristic algorithms is tied to the experience gained in the parallel splitting. Parallelism obtained through the physical separation of data has seen some success, especially at the data element level. Data parallelism on a grander scale requires models that accurately reflect the effects of blocking caused by finite queues. A model for the approximation of the performance of finite queueing networks is developed. This model makes use of the decomposition approach combined with the efficiency of product form solutions.

  17. Evaluation of the impact chip multiprocessors have on SNL application performance.

    SciTech Connect

    Doerfler, Douglas W.

    2009-10-01

    This report describes trans-organizational efforts to investigate the impact of chip multiprocessors (CMPs) on the performance of important Sandia application codes. The impact of CMPs on the performance and applicability of Sandia's system software was also investigated. The goal of the investigation was to make algorithmic and architectural recommendations for next generation platform acquisitions.

  18. SIFT - Multiprocessor architecture for Software Implemented Fault Tolerance flight control and avionics computers

    NASA Technical Reports Server (NTRS)

    Forman, P.; Moses, K.

    1979-01-01

    A brief description of a SIFT (Software Implemented Fault Tolerance) Flight Control Computer with emphasis on implementation is presented. A multiprocessor system that relies on software-implemented fault detection and reconfiguration algorithms is described. A high level reliability and fault tolerance is achieved by the replication of computing tasks among processing units.

  19. Scheduling and process migration in partitioned multiprocessors

    SciTech Connect

    Gait, J. )

    1990-03-01

    A partitioned multiprocessor (PM) has a shared global bus and nonshared local memories. This paper studies a process scheduler, called the two-tier scheduler (TTS), for a PM. In a PM local scheduling amortizes the cost of loading processes in local memory. Global scheduling migrates processes to balance load. A tunable time quantum is adjusted so the average process completes execution on the processor on which it is first scheduled, and only relatively long lived processes are rescheduled globally.

  20. Scalable Multiprocessor for High-Speed Computing in Space

    NASA Technical Reports Server (NTRS)

    Lux, James; Lang, Minh; Nishimoto, Kouji; Clark, Douglas; Stosic, Dorothy; Bachmann, Alex; Wilkinson, William; Steffke, Richard

    2004-01-01

    A report discusses the continuing development of a scalable multiprocessor computing system for hard real-time applications aboard a spacecraft. "Hard realtime applications" signifies applications, like real-time radar signal processing, in which the data to be processed are generated at "hundreds" of pulses per second, each pulse "requiring" millions of arithmetic operations. In these applications, the digital processors must be tightly integrated with analog instrumentation (e.g., radar equipment), and data input/output must be synchronized with analog instrumentation, controlled to within fractions of a microsecond. The scalable multiprocessor is a cluster of identical commercial-off-the-shelf generic DSP (digital-signal-processing) computers plus generic interface circuits, including analog-to-digital converters, all controlled by software. The processors are computers interconnected by high-speed serial links. Performance can be increased by adding hardware modules and correspondingly modifying the software. Work is distributed among the processors in a parallel or pipeline fashion by means of a flexible master/slave control and timing scheme. Each processor operates under its own local clock; synchronization is achieved by broadcasting master time signals to all the processors, which compute offsets between the master clock and their local clocks.

  1. Fault-free performance validation of avionic multiprocessors

    NASA Technical Reports Server (NTRS)

    Czeck, Edward W.; Feather, Frank E.; Grizzaffi, Ann Marie; Segall, Zary Z.; Finelli, George B.

    1986-01-01

    This paper describes the application of a portion of a validation methodology to NASA's Fault-Tolerant Multiprocessor System (FTMP) and the Software Implemented Fault-Tolerance (SIFT) computer system. The methodology entails a building block approach, starting with simple baseline experiments and building to more complex experiments. The goal of the validation methodology is to thoroughly test and characterize the performance and behavior of ultrareliable computer systems. The validation methodology presented in this paper showed that the methodology is not machine specific and can be used in lieu of life testing approaches. By applying a building block approach at the systems level, the machine complexity was broken down to manageable levels independent of system implementation.

  2. Introducing an Absolute Cavity Pyrgeometer (ACP) for Improving the Atmospheric Longwave Irradiance Measurement (Poster)

    SciTech Connect

    Reda, I.; Stoffel, T.

    2012-03-01

    Advancing climate change research requires accurate and traceable measurement of the atmospheric longwave irradiance. Current measurement capabilities are limited to an estimated uncertainty of larger than +/- 4 W/m2 using the interim World Infrared Standard Group (WISG). WISG is traceable to the Systeme international d'unites (SI) through blackbody calibrations. An Absolute Cavity Pyrgeometer (ACP) is being developed to measure absolute outdoor longwave irradiance with traceability to SI using the temperature scale (ITS-90) and the sky as the reference source, instead of a blackbody. The ACP was designed by NREL and optically characterized by the National Institute of Standards and Technology (NIST). Under clear-sky and stable conditions, the responsivity of the ACP is determined by lowering the temperature of the cavity and calculating the rate of change of the thermopile output voltage versus the changing net irradiance. The absolute atmospheric longwave irradiance is then calculated with an uncertainty of +/- 3.96 W/m2 with traceability to SI. The measured irradiance by the ACP was compared with the irradiance measured by two pyrgeometers calibrated by the World Radiation Center with traceability to the WISG.

  3. Identification of Genes Required for Secretion of the Francisella Oxidative Burst-Inhibiting Acid Phosphatase AcpA.

    PubMed

    Hoang, Ky Van; Chen, Carolyn G; Koopman, Jacob; Moshiri, Jasmine; Adcox, Haley E; Gunn, John S

    2016-01-01

    Francisella tularensis is a Tier 1 bioterror threat and the intracellular pathogen responsible for tularemia in humans and animals. Upon entry into the host, Francisella uses multiple mechanisms to evade killing. Our previous studies have shown that after entering its primary cellular host, the macrophage, Francisella immediately suppresses the oxidative burst by secreting a series of acid phosphatases including AcpA-B-C and HapA, thereby evading the innate immune response of the macrophage and enhancing survival and further infection. However, the mechanism of acid phosphatase secretion by Francisella is still unknown. In this study, we screened for genes required for AcpA secretion in Francisella. We initially demonstrated that the known secretion systems, the putative Francisella-pathogenicity island (FPI)-encoded Type VI secretion system and the Type IV pili, do not secrete AcpA. Using random transposon mutagenesis in conjunction with ELISA, Western blotting and acid phosphatase enzymatic assays, a transposon library of 5450 mutants was screened for strains with a minimum 1.5-fold decrease in secreted (culture supernatant) AcpA, but no defect in cytosolic AcpA. Three mutants with decreased supernatant AcpA were identified. The transposon insertion sites of these mutants were revealed by direct genomic sequencing or inverse-PCR and sequencing. One of these mutants has a severe defect in AcpA secretion (at least 85% decrease) and is a predicted hypothetical inner membrane protein. Interestingly, this mutant also affected the secretion of the FPI-encoded protein, VgrG. Thus, this screen identified novel protein secretion factors involved in the subversion of host defenses. PMID:27199935

  4. Identification of Genes Required for Secretion of the Francisella Oxidative Burst-Inhibiting Acid Phosphatase AcpA

    PubMed Central

    Hoang, Ky Van; Chen, Carolyn G.; Koopman, Jacob; Moshiri, Jasmine; Adcox, Haley E.; Gunn, John S.

    2016-01-01

    Francisella tularensis is a Tier 1 bioterror threat and the intracellular pathogen responsible for tularemia in humans and animals. Upon entry into the host, Francisella uses multiple mechanisms to evade killing. Our previous studies have shown that after entering its primary cellular host, the macrophage, Francisella immediately suppresses the oxidative burst by secreting a series of acid phosphatases including AcpA-B-C and HapA, thereby evading the innate immune response of the macrophage and enhancing survival and further infection. However, the mechanism of acid phosphatase secretion by Francisella is still unknown. In this study, we screened for genes required for AcpA secretion in Francisella. We initially demonstrated that the known secretion systems, the putative Francisella-pathogenicity island (FPI)-encoded Type VI secretion system and the Type IV pili, do not secrete AcpA. Using random transposon mutagenesis in conjunction with ELISA, Western blotting and acid phosphatase enzymatic assays, a transposon library of 5450 mutants was screened for strains with a minimum 1.5-fold decrease in secreted (culture supernatant) AcpA, but no defect in cytosolic AcpA. Three mutants with decreased supernatant AcpA were identified. The transposon insertion sites of these mutants were revealed by direct genomic sequencing or inverse-PCR and sequencing. One of these mutants has a severe defect in AcpA secretion (at least 85% decrease) and is a predicted hypothetical inner membrane protein. Interestingly, this mutant also affected the secretion of the FPI-encoded protein, VgrG. Thus, this screen identified novel protein secretion factors involved in the subversion of host defenses. PMID:27199935

  5. Fault recovery characteristics of the fault tolerant multi-processor

    NASA Technical Reports Server (NTRS)

    Padilla, Peter A.

    1990-01-01

    The fault handling performance of the fault tolerant multiprocessor (FTMP) was investigated. Fault handling errors detected during fault injection experiments were characterized. In these fault injection experiments, the FTMP disabled a working unit instead of the faulted unit once every 500 faults, on the average. System design weaknesses allow active faults to exercise a part of the fault management software that handles byzantine or lying faults. It is pointed out that these weak areas in the FTMP's design increase the probability that, for any hardware fault, a good LRU (line replaceable unit) is mistakenly disabled by the fault management software. It is concluded that fault injection can help detect and analyze the behavior of a system in the ultra-reliable regime. Although fault injection testing cannot be exhaustive, it has been demonstrated that it provides a unique capability to unmask problems and to characterize the behavior of a fault-tolerant system.

  6. An Analysis of an Improved Bus-Based Multiprocessor Architecture

    NASA Technical Reports Server (NTRS)

    Ricks, Kenneth G.; Wells, B. Earl

    1998-01-01

    This paper analyses the effectiveness of a hybrid multiprocessing/multicomputing architecture that is based upon a single-board-computer multiprocessor (SBCM) architecture. Based upon empirical analysis using discrete event simulations and Monte Carlo techniques, this hybrid architecture, called the enhanced single-board-computer multiprocessor (ESBCM), is shown to have improved performance and scalability characteristics over current SBCM designs.

  7. The Interactions of CPP–ACP with Saliva

    PubMed Central

    Huq, Noorjahan Laila; Myroforidis, Helen; Cross, Keith J.; Stanton, David P.; Veith, Paul D.; Ward, Brent R.; Reynolds, Eric C.

    2016-01-01

    The repair of early dental caries lesions has been demonstrated by the application of the remineralisation technology based on casein phosphopeptide-stabilised amorphous calcium phosphate complexes (CPP–ACP). These complexes consist of an amorphous calcium phosphate mineral phase stabilised and encapsulated by the self-assembly of milk-derived phosphopeptides. During topical application of CPP–ACP complexes in the oral cavity, the CPP encounters the enamel pellicle consisting of salivary proteins and peptides. However the interactions of the CPP with the enamel salivary pellicle are not known. The studies presented here reveal that the predominant peptides of CPP–ACP complexes do interact with specific salivary proteins and peptides of the enamel pellicle, and provide a mechanism by which the CPP–ACP complexes are localised at the tooth surface to promote remineralisation. PMID:27294918

  8. The Interactions of CPP-ACP with Saliva.

    PubMed

    Huq, Noorjahan Laila; Myroforidis, Helen; Cross, Keith J; Stanton, David P; Veith, Paul D; Ward, Brent R; Reynolds, Eric C

    2016-01-01

    The repair of early dental caries lesions has been demonstrated by the application of the remineralisation technology based on casein phosphopeptide-stabilised amorphous calcium phosphate complexes (CPP-ACP). These complexes consist of an amorphous calcium phosphate mineral phase stabilised and encapsulated by the self-assembly of milk-derived phosphopeptides. During topical application of CPP-ACP complexes in the oral cavity, the CPP encounters the enamel pellicle consisting of salivary proteins and peptides. However the interactions of the CPP with the enamel salivary pellicle are not known. The studies presented here reveal that the predominant peptides of CPP-ACP complexes do interact with specific salivary proteins and peptides of the enamel pellicle, and provide a mechanism by which the CPP-ACP complexes are localised at the tooth surface to promote remineralisation. PMID:27294918

  9. Selection on the Drosophila seminal fluid protein Acp62F

    PubMed Central

    Wong, Alex; Rundle, Howard

    2013-01-01

    Sperm competition and sexual conflict are thought to underlie the rapid evolution of reproductive proteins in many taxa. While comparative data are generally consistent with these hypotheses, few manipulative tests have been conducted and those that have provided contradictory results in some cases. Here, we use both comparative and experimental techniques to investigate the evolution of the Drosophila melanogaster seminal fluid protein Acp62F, a protease inhibitor for which extensive functional tests have yielded ambiguous results. Using between-species sequence comparisons, we show that Acp62F has been subject to recurrent positive selection. In addition, we experimentally evolved populations polymorphic for an Acp62F null allele over eight generations, manipulating the opportunities for natural and sexual selection. We found that the Acp62F null allele increased in frequency in the presence of natural selection, with no effect of sexual selection. PMID:23919141

  10. Multiprocessor switch with selective pairing

    SciTech Connect

    Gara, Alan; Gschwind, Michael K; Salapura, Valentina

    2014-03-11

    System, method and computer program product for a multiprocessing system to offer selective pairing of processor cores for increased processing reliability. A selective pairing facility is provided that selectively connects, i.e., pairs, multiple microprocessor or processor cores to provide one highly reliable thread (or thread group). Each paired microprocessor or processor cores that provide one highly reliable thread for high-reliability connect with a system components such as a memory "nest" (or memory hierarchy), an optional system controller, and optional interrupt controller, optional I/O or peripheral devices, etc. The memory nest is attached to a selective pairing facility via a switch or a bus

  11. 26 CFR 1.401(m)-2 - ACP test.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... satisfy the ACP test, but not in excess of 100%. In this case, an increase in the match rate from 50% to... under the ACP test only to the extent they do not exceed 25.00% of compensation. In this case, all of... determined under § 1.401(m)-2(b)(2)(iv) (as it appeared in the April 1, 2007, edition of 26 CFR part 1)....

  12. A robot arm simulation with a shared memory multiprocessor machine

    NASA Technical Reports Server (NTRS)

    Kim, Sung-Soo; Chuang, Li-Ping

    1989-01-01

    A parallel processing scheme for a single chain robot arm is presented for high speed computation on a shared memory multiprocessor. A recursive formulation that is derived from a virtual work form of the d'Alembert equations of motion is utilized for robot arm dynamics. A joint drive system that consists of a motor rotor and gears is included in the arm dynamics model, in order to take into account gyroscopic effects due to the spinning of the rotor. The fine grain parallelism of mechanical and control subsystem models is exploited, based on independent computation associated with bodies, joint drive systems, and controllers. Efficiency and effectiveness of the parallel scheme are demonstrated through simulations of a telerobotic manipulator arm. Two different mechanical subsystem models, i.e., with and without gyroscopic effects, are compared, to show the trade-off between efficiency and accuracy.

  13. Safe and Efficient Support for Embeded Multi-Processors in ADA

    NASA Astrophysics Data System (ADS)

    Ruiz, Jose F.

    2010-08-01

    New software demands increasing processing power, and multi-processor platforms are spreading as the answer to achieve the required performance. Embedded real-time systems are also subject to this trend, but in the case of real-time mission-critical systems, the properties of reliability, predictability and analyzability are also paramount. The Ada 2005 language defined a subset of its tasking model, the Ravenscar profile, that provides the basis for the implementation of deterministic and time analyzable applications on top of a streamlined run-time system. This Ravenscar tasking profile, originally designed for single processors, has proven remarkably useful for modelling verifiable real-time single-processor systems. This paper proposes a simple extension to the Ravenscar profile to support multi-processor systems using a fully partitioned approach. The implementation of this scheme is simple, and it can be used to develop applications amenable to schedulability analysis.

  14. MPF: A portable message passing facility for shared memory multiprocessors

    NASA Technical Reports Server (NTRS)

    Malony, Allen D.; Reed, Daniel A.; Mcguire, Patrick J.

    1987-01-01

    The design, implementation, and performance evaluation of a message passing facility (MPF) for shared memory multiprocessors are presented. The MPF is based on a message passing model conceptually similar to conversations. Participants (parallel processors) can enter or leave a conversation at any time. The message passing primitives for this model are implemented as a portable library of C function calls. The MPF is currently operational on a Sequent Balance 21000, and several parallel applications were developed and tested. Several simple benchmark programs are presented to establish interprocess communication performance for common patterns of interprocess communication. Finally, performance figures are presented for two parallel applications, linear systems solution, and iterative solution of partial differential equations.

  15. Analysis of fork-join program response times on multiprocessors

    SciTech Connect

    Towsley, D.; Stankovic, J.A. . Dept. of Computer and Information Science); Rommel, C.G. )

    1990-07-01

    In this paper, the authors develop analytic models for a shared memory multiprocessor that executes fork-join parallel programs. Here a fork-join program is one that consists of a set of n {ge} 1 parallel tasks. All of the tasks of a program arrive simultaneously to the system and the job is assumed to complete when the last task completes. They develop and analyze models for two processor sharing policies, called task scheduling processor sharing and job scheduling processor sharing. The first policy schedules tasks independently of each other and allows parallel execution of an individual program, whereas the second policy schedules each job as a unit and thereby does not allow parallel execution of an individual program.

  16. Testing and operating a multiprocessor chip with processor redundancy

    DOEpatents

    Bellofatto, Ralph E; Douskey, Steven M; Haring, Rudolf A; McManus, Moyra K; Ohmacht, Martin; Schmunkamp, Dietmar; Sugavanam, Krishnan; Weatherford, Bryan J

    2014-10-21

    A system and method for improving the yield rate of a multiprocessor semiconductor chip that includes primary processor cores and one or more redundant processor cores. A first tester conducts a first test on one or more processor cores, and encodes results of the first test in an on-chip non-volatile memory. A second tester conducts a second test on the processor cores, and encodes results of the second test in an external non-volatile storage device. An override bit of a multiplexer is set if a processor core fails the second test. In response to the override bit, the multiplexer selects a physical-to-logical mapping of processor IDs according to one of: the encoded results in the memory device or the encoded results in the external storage device. On-chip logic configures the processor cores according to the selected physical-to-logical mapping.

  17. Substrate Recognition by β-Ketoacyl-ACP Synthases†

    PubMed Central

    Borgaro, Janine G.; Chang, Andrew; Machutta, Carl A.; Zhang, Xujie; Tonge, Peter J.

    2011-01-01

    β-Ketoacyl-ACP synthase (KAS) enzymes catalyze Claisen condensation reactions in the fatty acid biosynthesis pathway. These reactions follow a ping-pong mechanism in which a donor substrate acylates the active site cysteine residue after which the acyl group is condensed with the malonyl-ACP acceptor substrate to form a β-ketoacyl-ACP. In the priming KASIII enzymes the donor substrate is an acyl-CoA while in the elongating KASI and KASII enzymes the donor is an acyl-ACP. Although the KASIII enzyme in Escherichia coli (ecFabH) is essential, the corresponding enzyme in Mycobacterium tuberculosis (mtFabH) is not, suggesting that the KASI or II enzyme in M. tuberculosis (KasA or KasB, respectively) must be able to accept a CoA donor substrate. Since KasA is essential, the substrate specificity of this KASI enzyme has been explored using substrates based on phosphopantetheine, CoA, ACP and AcpM peptide mimics. This analysis has been extended to the KASI and KASII enzymes from E. coli (ecFabB and ecFabF) where we show that a 14 residue malonyl-phosphopantetheine peptide can efficiently replace malonyl-ecACP as the acceptor substrate in the ecFabF reaction. While ecFabF is able to catalyze the condensation reaction when CoA is the carrier for both substrates, the KASI enzymes ecFabB and KasA have an absolute requirement for an ACP substrate as the acyl donor. Provided that this requirement is met, variation in the acceptor carrier substrate has little impact on the kcat/Km for the KASI reaction. For the KASI enzymes we propose that the binding of ecACP (AcpM) results in a conformational change that leads to an open form of the enzyme to which the malonyl acceptor substrate binds. Finally, the substrate inhibition observed when palmitoyl-CoA is the donor substrate for the KasA reaction has implications for the importance of mtFabH in the mycobacterial FASII pathway. PMID:22017312

  18. Substrate recognition by β-ketoacyl-ACP synthases.

    PubMed

    Borgaro, Janine G; Chang, Andrew; Machutta, Carl A; Zhang, Xujie; Tonge, Peter J

    2011-12-13

    β-Ketoacyl-ACP synthase (KAS) enzymes catalyze Claisen condensation reactions in the fatty acid biosynthesis pathway. These reactions follow a ping-pong mechanism in which a donor substrate acylates the active site cysteine residue after which the acyl group is condensed with the malonyl-ACP acceptor substrate to form a β-ketoacyl-ACP. In the priming KASIII enzymes the donor substrate is an acyl-CoA while in the elongating KASI and KASII enzymes the donor is an acyl-ACP. Although the KASIII enzyme in Escherichia coli (ecFabH) is essential, the corresponding enzyme in Mycobacterium tuberculosis (mtFabH) is not, suggesting that the KASI or II enzyme in M. tuberculosis (KasA or KasB, respectively) must be able to accept a CoA donor substrate. Since KasA is essential, the substrate specificity of this KASI enzyme has been explored using substrates based on phosphopantetheine, CoA, ACP, and AcpM peptide mimics. This analysis has been extended to the KASI and KASII enzymes from E. coli (ecFabB and ecFabF) where we show that a 14-residue malonyl-phosphopantetheine peptide can efficiently replace malonyl-ecACP as the acceptor substrate in the ecFabF reaction. While ecFabF is able to catalyze the condensation reaction when CoA is the carrier for both substrates, the KASI enzymes ecFabB and KasA have an absolute requirement for an ACP substrate as the acyl donor. Provided that this requirement is met, variation in the acceptor carrier substrate has little impact on the k(cat)/K(m) for the KASI reaction. For the KASI enzymes we propose that the binding of ecACP (AcpM) results in a conformational change that leads to an open form of the enzyme to which the malonyl acceptor substrate binds. Finally, the substrate inhibition observed when palmitoyl-CoA is the donor substrate for the KasA reaction has implications for the importance of mtFabH in the mycobacterial FASII pathway. PMID:22017312

  19. Mode of action of anticancer peptides (ACPs) from amphibian origin.

    PubMed

    Oelkrug, Christopher; Hartke, Martin; Schubert, Andreas

    2015-02-01

    Although cancer belongs to one of the leading causes of death around the world, fortunately studies have shown that tumor cells have various targets that are susceptible to attack. Interestingly, tumor cells are comprised of cellular membranes, which are altered in chemical composition relative to non-neoplastic cells, giving them an increased net negative charge. These altered membranes are ideal targets for antimicrobial peptides (AMPs) shown to have additional tumoricidal properties and, hence, named anticancer peptides (ACPs). Several hundred ACPs have been explored in vitro and in vivo on various types of cancer. Novel anticancer agents are supposed not to cause serious side effects and the formation of multidrug-resistant tumor cells. During the quest for potent ACPs, promising candidates were isolated from skin secretions of amphibians, such as the granular glands of the Chinese brown frog, Rana chensinensis. ACPs have to be selective to cancer cells and should not induce strong immune responses or be cleared from the body rapidly. Several modifications can improve ACPs either by optimizing the primary structure rationally or randomly or even by introducing other chemical modifications. PMID:25667440

  20. Transition metal HE`s - VII ACP. Progress report, August 1971--October 1971

    SciTech Connect

    Clink, G.L.

    1998-12-31

    Physical and physicochemical properties of hexaamminechromium III perchlorate (ACP) were investigated to determine its potentiality for HE and/or HE component application. Physicochemical properties obtained through investigation of isothermally aged ACP under conditions of various system and boundary restrictions (open and closed; 50 and 80 C; 0.65 and 0.85 g/cc) show the material to be substantially stable under these simulated isothermal storage conditions from a standpoint of infrared and DTA thermal pattern behavior and chemical analysis of aged residues. Spark sensitivity was 0.25 joules at 5 kv (by LASL type test) and impact sensitivity was about 23 and 14 cm on sandpaper (12A) and steel (12B), respectively.

  1. RTMPL: A structured programming and documentation utility for real-time multiprocessor simulations

    NASA Technical Reports Server (NTRS)

    Arpasi, D. J.

    1984-01-01

    The NASA Lewis Research Center is developing and evaluating experimental hardware and software systems to help meet future needs for real time simulations of air-breathing propulsion systems. The Real Time Multiprocessor Simulator (RTMPS) project is aimed at developing a prototype simulator system that uses multiple microprocessors to achieve the desired computing speed and accuracy at relatively low cost. Software utilities are being developed to provide engineering-level programming and interactive operation of the simulator. Two major software development efforts were undertaken in the RTMPS project. A real time multiprocessor operating system was developed to provide for interactive operation of the simulator. The second effort was aimed at developing a structured, high-level, engineering-oriented programming language and translator that would facilitate the programming of the simulator. The Real Time Multiprocessor Programming Language (RTMPL) allows the user to describe simulation tasks for each processor in a straight-forward, structured manner. The RTMPL utility acts as an assembly language programmer, translating the high-level simulation description into time-efficient assembly language code for the processors. The utility sets up all of the interfaces between the simulator hardware, firmware, and operating system.

  2. Analysis and comparison of cache coherence protocols for a packet-switched multiprocessor

    SciTech Connect

    Yang, Q.; Bhuyan, L.N.; Liu, B.C.

    1989-08-01

    The use of private caches in a multiprocessor system causes inconsistency of the shared data among the caches and among caches and the main memory. A large number of protocols have been proposed to solve this coherence problem. In this paper, the authors develop analytical models for seven existing cache protocols, namely: Write-Once, Write-Through, Synapse, Berkeley, Illinois, Firefly, and Dragon. The protocols are implemented on a multiprocessor with a packet-switched shared bus. The models are based on queueing networks that consist of both open and closed classes of customers. The models incorporate the requests for invalidation signals, write-through, and write-back operations and the solution is based on the mean value analysis (MVA) algorithm. Performance comparison among these protocols under various system parameters is carried out based on our models.

  3. High throughput network for multiprocessor interconnections

    NASA Astrophysics Data System (ADS)

    Raatikainen, Pertti; Zidbeck, Juha

    1993-05-01

    Multiprocessor architectures are needed to support modern broadband applications, since traditional bus structures are not capable of providing high throughput. New bus structures are needed, especially in the area of network components and terminals. A study to find an efficient and cost effective interconnection topology for the future high speed products is presented. The most common bus topologies are introduced, and their characteristics are estimated to decide which one of them offers best performance and lowest implementation cost. The ring topology is chosen to be studied in more detail. Four competing bus access schemes for the high throughput ring are introduced as well as simulation models for each of them. Using transfer delay and throughput results, as well as keeping the implementation point of view in mind, the best candidate is selected to be studied and experimented in the succeeding research project.

  4. ACP research and scientific coordination: Annual performance report

    SciTech Connect

    Hales, J.M.

    1992-09-17

    This research grant addresses two primary objectives: 1. Conduct of specific research tasks under the DOE Atmospheric Chemistry Program (ACP), and 2. Provision of scientific coordination for the Atmospheric Chemistry Program. In summary, the project is progressing essentially as expected, with some minor exceptions. Higher than anticipated demands within Objective 2, associated primarily with the ACP Ozone Project and the recompetition of the National Laboratories protion of ACP, have resulted in a somewhat higher proportionate emphasis on the coordination activities associated with this objective. Also, the immediate need for pre-campaign modeling of the North Pacific has resulted in an acceleration of the Pacific modeling task relative to other tasks, particularly the Atlantic modeling task. Modeling activities in general have been delayed somewhat because of the noted Objective 2 demands and because of the extended time that was necessary to complete financial agreements for this grant.

  5. Palmitoyl-acyl carrier protein (ACP) thioesterase and the evolutionary origin of plant acyl-ACP thioesterases.

    PubMed Central

    Jones, A; Davies, H M; Voelker, T A

    1995-01-01

    Acyl-acyl carrier protein (ACP) thioesterases play an essential role in chain termination during de novo fatty acid synthesis and in the channeling of carbon flux between the two lipid biosynthesis pathways in plants. We have discovered that there are two distinct but related thioesterase gene classes in higher plants, termed FatA and FatB, whose evolutionary divergence appears to be ancient. FatA encodes the already described 18:1-ACP thioesterase. In contrast, FatB representatives encode thioesterases preferring acyl-ACPs having saturated acyl groups. We unexpectedly obtained a 16:0-ACP thioesterase cDNA from Cuphea hookeriana seed, which accumulate predominantly 8:0 and 10:0. The 16:0 thioesterase transcripts were found in non-seed tissues, and expression in transgenic Brassica napus led to the production of a 16:0-rich oil. We present evidence that this type of FatB gene is ancient and ubiquitous in plants and that specialized plant medium-chain thioesterases have evolved independently from such enzymes several times during angiosperm evolution. Also, the ubiquitous 18:1-ACP thioesterase appears to be a derivative of a 16:0 thioesterase. PMID:7734968

  6. Evolution of acyl-ACP-thioesterases and β-ketoacyl-ACP-synthases revealed by protein-protein interactions

    PubMed Central

    Beld, Joris; Blatti, Jillian L.; Behnke, Craig; Mendez, Michael; Burkart, Michael D.

    2014-01-01

    The fatty acid synthase (FAS) is a conserved primary metabolic enzyme complex capable of tolerating cross-species engineering of domains for the development of modified and overproduced fatty acids. In eukaryotes, acyl-acyl carrier protein thioesterases (TEs) off-load mature cargo from the acyl carrier protein (ACP), and plants have developed TEs for short/medium-chain fatty acids. We showed that engineering plant TEs into the green microalga Chlamydomonas reinhardtii does not result in the predicted shift in fatty acid profile. Since fatty acid biosynthesis relies on substrate recognition and protein-protein interactions between the ACP and its partner enzymes, we hypothesized that plant TEs and algal ACP do not functionally interact. Phylogenetic analysis revealed major evolutionary differences between FAS enzymes, including TEs and ketoacyl synthases (KSs), in which the former is present only in some species, whereas the latter is present in all, and has a common ancestor. In line with these results, TEs appeared to be selective towards their ACP partners whereas KSs showed promiscuous behavior across bacterial, plant and algal species. Based on phylogenetic analyses, in silico docking, in vitro mechanistic crosslinking and in vivo algal engineering, we propose that phylogeny can predict effective interactions between ACPs and partner enzymes. PMID:25110394

  7. Acalabrutinib (ACP-196): a selective second-generation BTK inhibitor.

    PubMed

    Wu, Jingjing; Zhang, Mingzhi; Liu, Delong

    2016-01-01

    More and more targeted agents become available for B cell malignancies with increasing precision and potency. The first-in-class Bruton's tyrosine kinase (BTK) inhibitor, ibrutinib, has been in clinical use for the treatment of chronic lymphocytic leukemia, mantle cell lymphoma, and Waldenstrom's macroglobulinemia. More selective BTK inhibitors (ACP-196, ONO/GS-4059, BGB-3111, CC-292) are being explored. Acalabrutinib (ACP-196) is a novel irreversible second-generation BTK inhibitor that was shown to be more potent and selective than ibrutinib. This review summarized the preclinical research and clinical data of acalabrutinib. PMID:26957112

  8. Effect of CPP-ACP Paste on Dental Caries in Primary Teeth

    PubMed Central

    Sitthisettapong, T.; Phantumvanit, P.; Huebner, C.; DeRouen, T.

    2012-01-01

    This clinical trial tested the effect of daily application of 10% w/v calcium phosphopeptide-amorphous calcium phosphate (CPP-ACP) paste for 1 yr when added to regular toothbrushing with fluoridated toothpaste to prevent dental caries in pre-school children. High-caries-risk children aged 2½ to 3½ yrs in a suburban area of central Thailand were assigned to receive either CPP-ACP (n = 150) or a placebo control (n = 146) in addition to fluoridated toothpaste. The International Caries Detection and Assessment System (ICDAS) was recorded at baseline, 6 mos, and 1 yr. At 1 yr, a significant increase in mean numbers of enamel and dentin caries lesions, as well as dmfs, was found in both groups (p < 0.001). No significant difference was observed between groups on these 3 outcome measures (p = 0.23, 0.84, and 0.91, respectively). The odds of enamel caries lesion transitions to a state of regression or stability, compared with progression from baseline, was also not different between groups [OR = 1.00, 95% CI (0.86, 1.17)]. This trial found that daily application of 10% w/v CPP-ACP paste on school days for 1 yr, when added to regular toothbrushing with a fluoride toothpaste, had no significant added effect in preventing caries in the primary dentition of these pre-school children (ClinicalTrials.gov number CT01 604109). PMID:22805294

  9. Effect of CPP-ACP paste on dental caries in primary teeth: a randomized trial.

    PubMed

    Sitthisettapong, T; Phantumvanit, P; Huebner, C; Derouen, T

    2012-09-01

    This clinical trial tested the effect of daily application of 10% w/v calcium phosphopeptide-amorphous calcium phosphate (CPP-ACP) paste for 1 yr when added to regular toothbrushing with fluoridated toothpaste to prevent dental caries in pre-school children. High-caries-risk children aged 2½ to 3½ yrs in a suburban area of central Thailand were assigned to receive either CPP-ACP (n = 150) or a placebo control (n = 146) in addition to fluoridated toothpaste. The International Caries Detection and Assessment System (ICDAS) was recorded at baseline, 6 mos, and 1 yr. At 1 yr, a significant increase in mean numbers of enamel and dentin caries lesions, as well as dmfs, was found in both groups (p < 0.001). No significant difference was observed between groups on these 3 outcome measures (p = 0.23, 0.84, and 0.91, respectively). The odds of enamel caries lesion transitions to a state of regression or stability, compared with progression from baseline, was also not different between groups [OR = 1.00, 95% CI (0.86, 1.17)]. This trial found that daily application of 10% w/v CPP-ACP paste on school days for 1 yr, when added to regular toothbrushing with a fluoride toothpaste, had no significant added effect in preventing caries in the primary dentition of these pre-school children (ClinicalTrials.gov number CT01 604109). PMID:22805294

  10. Performance modeling and measurement of real-time multiprocessors with time-shared buses

    SciTech Connect

    Woodbury, M.H.; Shin, K.G.

    1988-02-01

    A closed queueing network model is constructed to address workload effects on computer performance for a highly reliable unibus multiprocessor used in real-time control. The queueing model consists of multiserver nodes and a nonpreemptive priority queue. Use of this model requires partitioning the workload into task classes. The time average steady-state solution of the queuing model directly produces useful results that are necessary in performance evaluation. The model is experimentally justified with the Fault-Tolerant Multiprocessor (FTMP) located at the NASA AIRLAB. Extensive experiments are performed on FTMP with a synthetic workload generator (SWG) to directly measure performance parameters, such as processor idle time, system bus contention, and task processing times. These measurements determine values for parameters in the queueing model. Experimental and analytic results are then compared.

  11. Input/output system for multiprocessors

    SciTech Connect

    Bernick, D.L.; Chan, K.K.; Chan, W.M.; Dan, Y.F.; Hoang, D.M.; Hussain, Z.; Iswandhi, G.I.; Korpi, J.E.; Sanner, M.W.; Zwangerman, J.A.

    1989-04-11

    A device controller is described, comprising: a first port-input/output controller coupled to a first input/output channel bus; and a second port-input/output controlled coupled to a second input/output channel bus; each of the first and second port-input/output controllers having: a first ownership latch means for granting shared ownership of the device controller to a first host processor to provide a first data path on a first I/O channel through the first port I/O controller between the first host processor and any peripheral, and at least a second ownership latch means operative independently of the first ownership latch means for granting shared ownership of the device controller to a second host processor independently of the first port input/output controller to provide a second data path on a second I/O channel through the second port I/O controller between the second host processor and any peripheral devices coupled to the device controller.

  12. Specificities of the Acyl-Acyl Carrier Protein (ACP) Thioesterase and Glycerol-3-Phosphate Acyltransferase for Octadecenoyl-ACP Isomers (Identification of a Petroselinoyl-ACP Thioesterase in Umbelliferae).

    PubMed Central

    Dormann, P.; Frentzen, M.; Ohlrogge, J. B.

    1994-01-01

    This study was designed to address the question: How specific for double bond position and conformation are plant enzymes that act on oleoyl-acyl carrier protein (ACP)? Octadecenoyl-ACPs with cis double bonds at positions [delta]6, [delta]7, [delta]8, [delta]9, [delta]10, [delta]11, or [delta]12 and elaidyl (18:1[delta]9trans)-ACP were synthesized and used to characterize the substrate specificity of the acyl-ACP thioesterase and acyl-ACP:sn-glycerol-3-phosphate acyltransferase. The two enzymes were found to be specific for the [delta]9 position of the double bond. The thioesterase was highly specific for the [delta]9 cis conformation, but the transferase was almost equally active with the cis and the trans isomer of 18:1[delta]9-ACP. In plants such as the Umbelliferae species coriander (Coriandrum sativum L.) that accumulate petroselinic acid (18:1[delta]6cis) in their seed triacylglycerols, a high petroselinoyl-ACP thioesterase activity was found in addition to the oleoyl-ACP thioesterase. The two activities could be separated by anion-exchange chromatography, indicating that the petroselinoyl-ACP thioesterase is represented by a distinct polypeptide. PMID:12232130

  13. Development of markers for Delta9-Stearoyl-ACP-Desaturase (SAD) to screen for cold acclimation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Delta 9-Stearoyl-acyl carrier protein (ACP) desaturase (SAD) is an important enzyme of fatty acid biosynthesis in higher plants. Located in the plastid stroma, SAD catalyzes the desaturation of stearoyl-ACP to oleyl-ACP. SAD plays a key role in determining the ratio of saturated fatty acids to unsat...

  14. Modeling holo-ACP:DH and holo-ACP:KR complexes of modular polyketide synthases: a docking and molecular dynamics study

    PubMed Central

    2012-01-01

    Background Modular polyketide synthases are multifunctional megasynthases which biosynthesize a variety of secondary metabolites using various combinations of dehydratase (DH), ketoreductase (KR) and enoyl-reductase (ER) domains. During the catalysis of various reductive steps these domains act on a substrate moiety which is covalently attached to the phosphopantetheine (P-pant) group of the holo-Acyl Carrier Protein (holo-ACP) domain, thus necessitating the formation of holo-ACP:DH and holo-ACP:KR complexes. Even though three dimensional structures are available for DH, KR and ACP domains, no structures are available for DH or KR domains in complex with ACP or substrate moieties. Since Ser of holo-ACP is covalently attached to a large phosphopantetheine group, obtaining complexes involving holo-ACP by standard protein-protein docking has been a difficult task. Results We have modeled the holo-ACP:DH and holo-ACP:KR complexes for identifying specific residues on DH and KR domains which are involved in interaction with ACP, phosphopantetheine and substrate moiety. A novel combination of protein-protein and protein-ligand docking has been used to first model complexes involving apo-ACP and then dock the phosphopantetheine and substrate moieties using covalent connectivity between ACP, phosphopantetheine and substrate moiety as constraints. The holo-ACP:DH and holo-ACP:KR complexes obtained from docking have been further refined by restraint free explicit solvent MD simulations to incorporate effects of ligand and receptor flexibilities. The results from 50 ns MD simulations reveal that substrate enters into a deep tunnel in DH domain while in case of KR domain the substrate binds a shallow surface exposed cavity. Interestingly, in case of DH domain the predicted binding site overlapped with the binding site in the inhibitor bound crystal structure of FabZ, the DH domain from E.Coli FAS. In case of KR domain, the substrate binding site identified by our simulations

  15. Particle simulation in a multiprocessor environment

    NASA Technical Reports Server (NTRS)

    Mcdonald, Jeffrey D.

    1991-01-01

    A parallel implementation of a particle simulation method that is portable between a wide class of multiprocessor computers is presented. A fine grain spatial decomposition is utilized where several subdomains having a regular structure are computed at each processing node. This leads directly to an efficient and straightforward load balancing scheme if the number of subdomains at each processor is permitted to vary in an appropriate manner. Three dimensional simulations incorporating full thermochemical nonequilibrium are possible using the resulting code. Vectorizable algorithms are retained from earlier work allowing efficient use of deeply pipelined node processors where available. Performance results are presented from three different machine architectures demonstrating the portability of the code. On a 128-node Intel iPSC/860, performance is twice that of a single Cray-Y/MP CPU running a highly vectorized simulation code. Speedup is linear over the full range of number of processors on all target machines, indicating scalability of the method to higher degrees of parallelism.

  16. Coscheduling Technique for Symmetric Multiprocessor Clusters

    SciTech Connect

    Yoo, A B; Jette, M A

    2000-09-18

    Coscheduling is essential for obtaining good performance in a time-shared symmetric multiprocessor (SMP) cluster environment. However, the most common technique, gang scheduling, has limitations such as poor scalability and vulnerability to faults mainly due to explicit synchronization between its components. A decentralized approach called dynamic coscheduling (DCS) has been shown to be effective for network of workstations (NOW), but this technique is not suitable for the workloads on a very large SMP-cluster with thousands of processors. Furthermore, its implementation can be prohibitively expensive for such a large-scale machine. IN this paper, they propose a novel coscheduling technique based on the DCS approach which can achieve coscheduling on very large SMP-clusters in a scalable, efficient, and cost-effective way. In the proposed technique, each local scheduler achieves coscheduling based upon message traffic between the components of parallel jobs. Message trapping is carried out at the user-level, eliminating the need for unsupported hardware or device-level programming. A sending process attaches its status to outgoing messages so local schedulers on remote nodes can make more intelligent scheduling decisions. Once scheduled, processes are guaranteed some minimum period of time to execute. This provides an opportunity to synchronize the parallel job's components across all nodes and achieve good program performance. The results from a performance study reveal that the proposed technique is a promising approach that can reduce response time significantly over uncoordinated time-sharing and batch scheduling.

  17. Principles for problem aggregation and assignment in medium scale multiprocessors

    NASA Technical Reports Server (NTRS)

    Nicol, David M.; Saltz, Joel H.

    1987-01-01

    One of the most important issues in parallel processing is the mapping of workload to processors. This paper considers a large class of problems having a high degree of potential fine grained parallelism, and execution requirements that are either not predictable, or are too costly to predict. The main issues in mapping such a problem onto medium scale multiprocessors are those of aggregation and assignment. We study a method of parameterized aggregation that makes few assumptions about the workload. The mapping of aggregate units of work onto processors is uniform, and exploits locality of workload intensity to balance the unknown workload. In general, a finer aggregate granularity leads to a better balance at the price of increased communication/synchronization costs; the aggregation parameters can be adjusted to find a reasonable granularity. The effectiveness of this scheme is demonstrated on three model problems: an adaptive one-dimensional fluid dynamics problem with message passing, a sparse triangular linear system solver on both a shared memory and a message-passing machine, and a two-dimensional time-driven battlefield simulation employing message passing. Using the model problems, the tradeoffs are studied between balanced workload and the communication/synchronization costs. Finally, an analytical model is used to explain why the method balances workload and minimizes the variance in system behavior.

  18. Parallelization of NAS Benchmarks for Shared Memory Multiprocessors

    NASA Technical Reports Server (NTRS)

    Waheed, Abdul; Yan, Jerry C.; Saini, Subhash (Technical Monitor)

    1998-01-01

    This paper presents our experiences of parallelizing the sequential implementation of NAS benchmarks using compiler directives on SGI Origin2000 distributed shared memory (DSM) system. Porting existing applications to new high performance parallel and distributed computing platforms is a challenging task. Ideally, a user develops a sequential version of the application, leaving the task of porting to new generations of high performance computing systems to parallelization tools and compilers. Due to the simplicity of programming shared-memory multiprocessors, compiler developers have provided various facilities to allow the users to exploit parallelism. Native compilers on SGI Origin2000 support multiprocessing directives to allow users to exploit loop-level parallelism in their programs. Additionally, supporting tools can accomplish this process automatically and present the results of parallelization to the users. We experimented with these compiler directives and supporting tools by parallelizing sequential implementation of NAS benchmarks. Results reported in this paper indicate that with minimal effort, the performance gain is comparable with the hand-parallelized, carefully optimized, message-passing implementations of the same benchmarks.

  19. Multi-processor including data flow accelerator module

    DOEpatents

    Davidson, George S.; Pierce, Paul E.

    1990-01-01

    An accelerator module for a data flow computer includes an intelligent memory. The module is added to a multiprocessor arrangement and uses a shared tagged memory architecture in the data flow computer. The intelligent memory module assigns locations for holding data values in correspondence with arcs leading to a node in a data dependency graph. Each primitive computation is associated with a corresponding memory cell, including a number of slots for operands needed to execute a primitive computation, a primitive identifying pointer, and linking slots for distributing the result of the cell computation to other cells requiring that result as an operand. Circuitry is provided for utilizing tag bits to determine automatically when all operands required by a processor are available and for scheduling the primitive for execution in a queue. Each memory cell of the module may be associated with any of the primitives, and the particular primitive to be executed by the processor associated with the cell is identified by providing an index, such as the cell number for the primitive, to the primitive lookup table of starting addresses. The module thus serves to perform functions previously performed by a number of sections of data flow architectures and coexists with conventional shared memory therein. A multiprocessing system including the module operates in a hybrid mode, wherein the same processing modules are used to perform some processing in a sequential mode, under immediate control of an operating system, while performing other processing in a data flow mode.

  20. Efficient static scheduling of loops on synchronous multiprocessors

    SciTech Connect

    Zaky, A.M.

    1989-01-01

    This dissertation investigates efficient compile-time scheduling techniques for exploiting parallelism on synchronous multiprocessors. Synchronous multiprocessors, e.g. Very Long Instruction Word (VLIW) machines, are very effective in utilizing unstructured fine-grained parallelism in programs. The effectiveness of such machines is crucially dependent on the static compile-time analysis and detection of potential parallelism. The first part of the dissertation focuses on scheduling sequential loops on multiprocessors with multiple identical processor units. The problem of determining the maximal initiation rate for the execution of a sequential loop with uniform dependence distances on a synchronous multiprocessor is addressed and cast as an eigenvalue problem in a path algebra. A low-order polynomial algorithm for the determination of the optimal loop initiation rate is developed, and a schedule that exploits fine-grained parallelism and achieves the optimal initiation rate is developed under an idealized unbounded processor model. Next, the concepts developed above are extended to deal with perfectly-nested loops with uniform dependences. A strategy is developed to identify both the loop level and fine-grained expression level parallelism in nested loops, and to efficiently schedule such loops on synchronous multiprocessors. Loop scheduling techniques such as Do-Across, Wavefront scheduling, and fine-grained scheduling techniques such as loop unfolding are shown to be derivable within the presented framework.

  1. 26 CFR 1.401(m)-2 - ACP test.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... determined under § 1.401(m)-2(b)(2)(iv) (as it appeared in the April 1, 2007, edition of 26 CFR part 1). (E... determined under § 1.401(m)-2(b)(2)(vi) (as it appeared in the April 1, 2007, edition of 26 CFR Part 1). If... 26 Internal Revenue 5 2010-04-01 2010-04-01 false ACP test. 1.401(m)-2 Section 1.401(m)-2...

  2. Extended temperature range ACPS thruster investigation

    NASA Technical Reports Server (NTRS)

    Blubaugh, A. L.; Schoenman, L.

    1974-01-01

    The successful hot fire demonstration of a pulsing liquid hydrogen/liquid oxygen and gaseous hydrogen/liquid oxygen attitude control propulsion system thruster is described. The test was the result of research to develop a simple, lightweight, and high performance reaction control system without the traditional requirements for extensive periods of engine thermal conditioning, or the use of complex equipment to convert both liquid propellants to gas prior to delivery to the engine. Significant departures from conventional injector design practice were employed to achieve an operable design. The work discussed includes thermal and injector manifold priming analyses, subscale injector chilldown tests, and 168 full scale and 550 N (1250 lbF) rocket engine tests. Ignition experiments, at propellant temperatures ranging from cryogenic to ambient, led to the generation of a universal spark ignition system which can reliably ignite an engine when supplied with liquid, two phase, or gaseous propellants. Electrical power requirements for spark igniter are very low.

  3. Multi-objective two-stage multiprocessor flow shop scheduling - a subgroup particle swarm optimisation approach

    NASA Astrophysics Data System (ADS)

    Huang, Rong-Hwa; Yang, Chang-Lin; Hsu, Chun-Ting

    2015-12-01

    Flow shop production system - compared to other economically important production systems - is popular in real manufacturing environments. This study focuses on the flow shop with multiprocessor scheduling problem (FSMP), and develops an improved particle swarm optimisation heuristic to solve it. Additionally, this study designs an integer programming model to perform effectiveness and robustness testing on the proposed heuristic. Experimental results demonstrate a 10% to 50% improvement in the effectiveness of the proposed heuristic in small-scale problem tests, and a 10% to 40% improvement in the robustness of the heuristic in large-scale problem tests, indicating extremely satisfactory performance.

  4. The β-ketoacyl-ACP synthase from Mycobacterium tuberculosis as potential drug targets.

    PubMed

    Singh, V; Mani, I; Chaudhary, D K; Somvanshi, P

    2011-01-01

    The continuous preventive measures and control of tuberculosis are often hampered by re-emergence of multi-drug-resistant (MDR) strains of Mycobacterium tuberculosis. A novel drug approach is desperately needed to combat the global threat posed by MDR strains. In spite of current advancement in biological techniques viz. microarray and proteomics data for tuberculosis, no such potent drug has been developed in the past decades yet. Therefore, mycolic acid is an essential constituent which is involved in the formation of cell wall of Mycobacterium species. The biosynthesis of mycolic acid is involved in two fatty acid synthase systems, the multifunctional polypeptide fatty acid synthase I (FASI) which performs de novo fatty acid synthesis and dissociate FASII system. FASII system consists of monofunctional enzymes and acyl carrier protein (ACP), elongating FASI products to long chain mycolic acid precursor. In this review, the β-ketoacyl-ACP synthases (fadH, kasA and kasB) are distinct and play a vital role in mycolic acid synthesis, cell wall synthesis, biofilm formation and also pathogenesis. On the basis of substantial observation we suggest that these enzymes may be used as promising and attractive targets for novel anti-TB drugs designing and discovery. PMID:21370994

  5. Mapping of H.264 decoding on a multiprocessor architecture

    NASA Astrophysics Data System (ADS)

    van der Tol, Erik B.; Jaspers, Egbert G.; Gelderblom, Rob H.

    2003-05-01

    Due to the increasing significance of development costs in the competitive domain of high-volume consumer electronics, generic solutions are required to enable reuse of the design effort and to increase the potential market volume. As a result from this, Systems-on-Chip (SoCs) contain a growing amount of fully programmable media processing devices as opposed to application-specific systems, which offered the most attractive solutions due to a high performance density. The following motivates this trend. First, SoCs are increasingly dominated by their communication infrastructure and embedded memory, thereby making the cost of the functional units less significant. Moreover, the continuously growing design costs require generic solutions that can be applied over a broad product range. Hence, powerful programmable SoCs are becoming increasingly attractive. However, to enable power-efficient designs, that are also scalable over the advancing VLSI technology, parallelism should be fully exploited. Both task-level and instruction-level parallelism can be provided by means of e.g. a VLIW multiprocessor architecture. To provide the above-mentioned scalability, we propose to partition the data over the processors, instead of traditional functional partitioning. An advantage of this approach is the inherent locality of data, which is extremely important for communication-efficient software implementations. Consequently, a software implementation is discussed, enabling e.g. SD resolution H.264 decoding with a two-processor architecture, whereas High-Definition (HD) decoding can be achieved with an eight-processor system, executing the same software. Experimental results show that the data communication considerably reduces up to 65% directly improving the overall performance. Apart from considerable improvement in memory bandwidth, this novel concept of partitioning offers a natural approach for optimally balancing the load of all processors, thereby further improving the

  6. Biochemical and Structural Characterization of Germicidin Synthase: Analysis of a Type III Polyketide Synthase That Employs Acyl-ACP as a Starter Unit Donor

    SciTech Connect

    Chemler, Joseph A.; Buchholz, Tonia J.; Geders, Todd W.; Akey, David L.; Rath, Christopher M.; Chlipala, George E.; Smith, Janet L.; Sherman, David H.

    2012-08-10

    Germicidin synthase (Gcs) from Streptomyces coelicolor is a type III polyketide synthase (PKS) with broad substrate flexibility for acyl groups linked through a thioester bond to either coenzyme A (CoA) or acyl carrier protein (ACP). Germicidin synthesis was reconstituted in vitro by coupling Gcs with fatty acid biosynthesis. Since Gcs has broad substrate flexibility, we directly compared the kinetic properties of Gcs with both acyl-ACP and acyl-CoA. The catalytic efficiency of Gcs for acyl-ACP was 10-fold higher than for acyl-CoA, suggesting a strong preference toward carrier protein starter unit transfer. The 2.9 {angstrom} germicidin synthase crystal structure revealed canonical type III PKS architecture along with an unusual helical bundle of unknown function that appears to extend the dimerization interface. A pair of arginine residues adjacent to the active site affect catalytic activity but not ACP binding. This investigation provides new and surprising information about the interactions between type III PKSs and ACPs that will facilitate the construction of engineered systems for production of novel polyketides.

  7. Expression of Vibrio harveyi Acyl-ACP Synthetase Allows Efficient Entry of Exogenous Fatty Acids into the Escherichia coli Fatty Acid and Lipid A Synthetic Pathways

    PubMed Central

    Jiang, Yanfang; Morgan-Kiss, Rachael M.; Campbell, John W.; Chan, Chi Ho; Cronan, John E.

    2010-01-01

    Although the Escherichia coli fatty acid synthesis (FAS) pathway is the best studied type II fatty acid synthesis system, a major experimental limitation has been the inability to feed intermediates into the pathway in vivo because exogenously-supplied free fatty acids are not efficiently converted to the acyl-acyl carrier protein (ACP) thioesters required by the pathway. We report that expression of Vibrio harveyi acyl-ACP synthetase (AasS), a soluble cytosolic enzyme that ligates free fatty acids to ACP to form acyl-ACPs, allows exogenous fatty acids to enter the E. coli fatty acid synthesis pathway. The free fatty acids are incorporated intact and can be elongated or directly incorporated into complex lipids by acyltransferases specific for acyl-ACPs. Moreover, expression of AasS strains and supplementation with the appropriate fatty acid restored growth to E. coli mutant strains that lack essential fatty acid synthesis enzymes. Thus, this strategy provides a new tool for circumventing the loss of enzymes essential for FAS function. PMID:20028080

  8. Development and evaluation of a fault-tolerant multiprocessor (FTMP) computer. Volume 4: FTMP executive summary

    NASA Technical Reports Server (NTRS)

    Smith, T. B., III; Lala, J. H.

    1984-01-01

    The FTMP architecture is a high reliability computer concept modeled after a homogeneous multiprocessor architecture. Elements of the FTMP are operated in tight synchronism with one another and hardware fault-detection and fault-masking is provided which is transparent to the software. Operating system design and user software design is thus greatly simplified. Performance of the FTMP is also comparable to that of a simplex equivalent due to the efficiency of fault handling hardware. The FTMP project constructed an engineering module of the FTMP, programmed the machine and extensively tested the architecture through fault injection and other stress testing. This testing confirmed the soundness of the FTMP concepts.

  9. Implementation of two projection methods on a shared memory multiprocessor - DEC VAX 6240

    NASA Technical Reports Server (NTRS)

    Kamath, C.; Weeratunga, S.

    1990-01-01

    The relative performance of two iterative schemes, based on projection techniques, is compared on a shared memory multiprocessor - VAX 6240. The CG accelerated Block-SSOR method and the CG accelerated Symmetric-Kaczmarz method are considered for the solution of large sparse nonsymmetric systems of linear equations. It is shown that the regular structure of many matrices can be exploited by the CG-accelerated Block-SSOR method to provide good speedup in a multiprocessing environment. However, the CG accelerated Symmetric-Kaczmarz method, while being a viable alternative on a scalar machine, is unable to benefit from multiprocessing.

  10. Abnormal fault-recovery characteristics of the fault-tolerant multiprocessor uncovered using a new fault-injection methodology

    NASA Astrophysics Data System (ADS)

    Padilla, Peter A.

    1991-03-01

    An investigation was made in AIRLAB of the fault handling performance of the Fault Tolerant MultiProcessor (FTMP). Fault handling errors detected during fault injection experiments were characterized. In these fault injection experiments, the FTMP disabled a working unit instead of the faulted unit once in every 500 faults, on the average. System design weaknesses allow active faults to exercise a part of the fault management software that handles Byzantine or lying faults. Byzantine faults behave such that the faulted unit points to a working unit as the source of errors. The design's problems involve: (1) the design and interface between the simplex error detection hardware and the error processing software, (2) the functional capabilities of the FTMP system bus, and (3) the communication requirements of a multiprocessor architecture. These weak areas in the FTMP's design increase the probability that, for any hardware fault, a good line replacement unit (LRU) is mistakenly disabled by the fault management software.

  11. Abnormal fault-recovery characteristics of the fault-tolerant multiprocessor uncovered using a new fault-injection methodology

    NASA Technical Reports Server (NTRS)

    Padilla, Peter A.

    1991-01-01

    An investigation was made in AIRLAB of the fault handling performance of the Fault Tolerant MultiProcessor (FTMP). Fault handling errors detected during fault injection experiments were characterized. In these fault injection experiments, the FTMP disabled a working unit instead of the faulted unit once in every 500 faults, on the average. System design weaknesses allow active faults to exercise a part of the fault management software that handles Byzantine or lying faults. Byzantine faults behave such that the faulted unit points to a working unit as the source of errors. The design's problems involve: (1) the design and interface between the simplex error detection hardware and the error processing software, (2) the functional capabilities of the FTMP system bus, and (3) the communication requirements of a multiprocessor architecture. These weak areas in the FTMP's design increase the probability that, for any hardware fault, a good line replacement unit (LRU) is mistakenly disabled by the fault management software.

  12. BioThreads: a novel VLIW-based chip multiprocessor for accelerating biomedical image processing applications.

    PubMed

    Stevens, David; Chouliaras, Vassilios; Azorin-Peris, Vicente; Zheng, Jia; Echiadis, Angelos; Hu, Sijung

    2012-06-01

    We discuss BioThreads, a novel, configurable, extensible system-on-chip multiprocessor and its use in accelerating biomedical signal processing applications such as imaging photoplethysmography (IPPG). BioThreads is derived from the LE1 open-source VLIW chip multiprocessor and efficiently handles instruction, data and thread-level parallelism. In addition, it supports a novel mechanism for the dynamic creation, and allocation of software threads to uncommitted processor cores by implementing key POSIX Threads primitives directly in hardware, as custom instructions. In this study, the BioThreads core is used to accelerate the calculation of the oxygen saturation map of living tissue in an experimental setup consisting of a high speed image acquisition system, connected to an FPGA board and to a host system. Results demonstrate near-linear acceleration of the core kernels of the target blood perfusion assessment with increasing number of hardware threads. The BioThreads processor was implemented on both standard-cell and FPGA technologies; in the first case and for an issue width of two, full real-time performance is achieved with 4 cores whereas on a mid-range Xilinx Virtex6 device this is achieved with 10 dual-issue cores. An 8-core LE1 VLIW FPGA prototype of the system achieved 240 times faster execution time than the scalar Microblaze processor demonstrating the scalability of the proposed solution to a state-of-the-art FPGA vendor provided soft CPU core. PMID:23853147

  13. A multiprocessor computer simulation model employing a feedback scheduler/allocator for memory space and bandwidth matching and TMR processing

    NASA Technical Reports Server (NTRS)

    Bradley, D. B.; Irwin, J. D.

    1974-01-01

    A computer simulation model for a multiprocessor computer is developed that is useful for studying the problem of matching multiprocessor's memory space, memory bandwidth and numbers and speeds of processors with aggregate job set characteristics. The model assumes an input work load of a set of recurrent jobs. The model includes a feedback scheduler/allocator which attempts to improve system performance through higher memory bandwidth utilization by matching individual job requirements for space and bandwidth with space availability and estimates of bandwidth availability at the times of memory allocation. The simulation model includes provisions for specifying precedence relations among the jobs in a job set, and provisions for specifying precedence execution of TMR (Triple Modular Redundant and SIMPLEX (non redundant) jobs.

  14. Programmable Optoelectronic Multiprocessors: Design, Performance and CAD Development

    NASA Astrophysics Data System (ADS)

    Kiamilev, Fouad Eskender

    1992-01-01

    This thesis describes the development of Programmable Optoelectronic Multiprocessor (POEM) architectures and systems. POEM systems combine simple electronic processing elements with free-space optical interconnects to implement high-performance, massively-parallel computers. POEM architectures are fundamentally different from architectures used in conventional VLSI systems. Novel system partitioning and processing element design methods have been developed to ensure efficient implementation of POEM architectures with optoelectronic technology. The main contributions of this thesis are: architecture and software design for the POEM prototype built at UCSD; detailed technology design-tradeoff and comparison studies for POEM interconnection networks; and application of the VHSIC Hardware Description Language (VHDL) to the design, simulation, and synthesis of POEM computers. A general-purpose POEM SIMD parallel computer architecture has been designed for symbolic computing applications. A VHDL simulation of this architecture was written to test the POEM hardware running parallel programs prior to prototype fabrication. Detailed performance comparison of this architecture with all-optical computing, based on symbolic substitution, has also been carried out to show that POEMs offer higher computational efficiency. A detailed technological design of a packet-switched POEM multistage interconnection network system has been performed. This design uses optically interconnected stages of K x K electronic switching elements, where K is a variable parameter, called grain-size, that determines the ratio of optics to electronics in the system. A thorough cost and performance comparison between this design and existing VLSI implementations was undertaken to show that the POEM approach offers better scalability and higher performance. The grain-size was optimized, showing that switch sizes of 16 x 16 to 256 x 256 provide maximum performance/cost. The effects of varying

  15. Analysis of a Multiprocessor Guidance Computer. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Maltach, E. G.

    1969-01-01

    The design of the next generation of spaceborne digital computers is described. It analyzes a possible multiprocessor computer configuration. For the analysis, a set of representative space computing tasks was abstracted from the Lunar Module Guidance Computer programs as executed during the lunar landing, from the Apollo program. This computer performs at this time about 24 concurrent functions, with iteration rates from 10 times per second to once every two seconds. These jobs were tabulated in a machine-independent form, and statistics of the overall job set were obtained. It was concluded, based on a comparison of simulation and Markov results, that the Markov process analysis is accurate in predicting overall trends and in configuration comparisons, but does not provide useful detailed information in specific situations. Using both types of analysis, it was determined that the job scheduling function is a critical one for efficiency of the multiprocessor. It is recommended that research into the area of automatic job scheduling be performed.

  16. Using Pin as a Memory Reference Generator for Multiprocessor Simulation

    SciTech Connect

    McCurdy, C

    2005-10-22

    In this paper we describe how we have used Pin to generate a multithreaded reference stream for simulation of a multiprocessor on a uniprocessor. We have taken special care to model as accurately as possible the effects of cache coherence protocol state, and lock and barrier synchronization on the performance of multithreaded applications running on multiprocessor hardware. We first describe a simplified version of the algorithm, which uses semaphores to synchronize instrumented application threads and the simulator on every memory reference. We then describe modifications to that algorithm to model the microarchitectural features of the Itanium2 that affect the timing of memory reference issue. An experimental evaluation determines that while cycle-accurate multithreaded simulation is possible using our approach, the use of semaphores has a negative impact on the performance of the simulator.

  17. A single-assignment language in a distributed memory multiprocessor

    NASA Technical Reports Server (NTRS)

    Evripidou, P.; Najjar, W.; Gaudiot, J.-L.

    1989-01-01

    The implementation of the single-assignment programming language SISAL (McGraw et al., 1985) on a Symult 2010 parallel computer is described. The advantages of single-assignment languages over imperative languages in a multiprocessor environment are reviewed; the characteristics of SISAL are summarized; the program-graph generation and dynamic data partitioning procedures are explained; and the application of SISAL in constructing a concurrent iterative multigrid algorithm is discussed in detail and illustrated with diagrams.

  18. Phylogenetic and experimental characterization of an acyl-ACP thioesterase family reveals significant diversity in enzymatic specificity and activity

    PubMed Central

    2011-01-01

    Background Acyl-acyl carrier protein thioesterases (acyl-ACP TEs) catalyze the hydrolysis of the thioester bond that links the acyl chain to the sulfhydryl group of the phosphopantetheine prosthetic group of ACP. This reaction terminates acyl chain elongation of fatty acid biosynthesis, and in plant seeds it is the biochemical determinant of the fatty acid compositions of storage lipids. Results To explore acyl-ACP TE diversity and to identify novel acyl ACP-TEs, 31 acyl-ACP TEs from wide-ranging phylogenetic sources were characterized to ascertain their in vivo activities and substrate specificities. These acyl-ACP TEs were chosen by two different approaches: 1) 24 TEs were selected from public databases on the basis of phylogenetic analysis and fatty acid profile knowledge of their source organisms; and 2) seven TEs were molecularly cloned from oil palm (Elaeis guineensis), coconut (Cocos nucifera) and Cuphea viscosissima, organisms that produce medium-chain and short-chain fatty acids in their seeds. The in vivo substrate specificities of the acyl-ACP TEs were determined in E. coli. Based on their specificities, these enzymes were clustered into three classes: 1) Class I acyl-ACP TEs act primarily on 14- and 16-carbon acyl-ACP substrates; 2) Class II acyl-ACP TEs have broad substrate specificities, with major activities toward 8- and 14-carbon acyl-ACP substrates; and 3) Class III acyl-ACP TEs act predominantly on 8-carbon acyl-ACPs. Several novel acyl-ACP TEs act on short-chain and unsaturated acyl-ACP or 3-ketoacyl-ACP substrates, indicating the diversity of enzymatic specificity in this enzyme family. Conclusion These acyl-ACP TEs can potentially be used to diversify the fatty acid biosynthesis pathway to produce novel fatty acids. PMID:21831316

  19. Walking Together: A Narrative/Pastoral Approach to the ACPE Accreditation Site Visit

    ERIC Educational Resources Information Center

    Oertli, Karrie

    2010-01-01

    Walking together is a strong theme in religious literature: God companions persons, and persons companion one another. All share and hear stories in that action. The Association for Clinical Pastoral Education, Inc. (ACPE) began to walk together in 1967, as it gathered four organizations into one. ACPE has grown and changed, becoming world's…

  20. Solution of large nonlinear quasistatic structural mechanics problems on distributed-memory multiprocessor computers

    SciTech Connect

    Blanford, M.

    1997-12-31

    Most commercially-available quasistatic finite element programs assemble element stiffnesses into a global stiffness matrix, then use a direct linear equation solver to obtain nodal displacements. However, for large problems (greater than a few hundred thousand degrees of freedom), the memory size and computation time required for this approach becomes prohibitive. Moreover, direct solution does not lend itself to the parallel processing needed for today`s multiprocessor systems. This talk gives an overview of the iterative solution strategy of JAS3D, the nonlinear large-deformation quasistatic finite element program. Because its architecture is derived from an explicit transient-dynamics code, it does not ever assemble a global stiffness matrix. The author describes the approach he used to implement the solver on multiprocessor computers, and shows examples of problems run on hundreds of processors and more than a million degrees of freedom. Finally, he describes some of the work he is presently doing to address the challenges of iterative convergence for ill-conditioned problems.

  1. The mitochondrial acyl carrier protein (ACP) coordinates mitochondrial fatty acid synthesis with iron sulfur cluster biogenesis

    PubMed Central

    Van Vranken, Jonathan G; Jeong, Mi-Young; Wei, Peng; Chen, Yu-Chan; Gygi, Steven P; Winge, Dennis R; Rutter, Jared

    2016-01-01

    Mitochondrial fatty acid synthesis (FASII) and iron sulfur cluster (FeS) biogenesis are both vital biosynthetic processes within mitochondria. In this study, we demonstrate that the mitochondrial acyl carrier protein (ACP), which has a well-known role in FASII, plays an unexpected and evolutionarily conserved role in FeS biogenesis. ACP is a stable and essential subunit of the eukaryotic FeS biogenesis complex. In the absence of ACP, the complex is destabilized resulting in a profound depletion of FeS throughout the cell. This role of ACP depends upon its covalently bound 4’-phosphopantetheine (4-PP)-conjugated acyl chain to support maximal cysteine desulfurase activity. Thus, it is likely that ACP is not simply an obligate subunit but also exploits the 4-PP-conjugated acyl chain to coordinate mitochondrial fatty acid and FeS biogenesis. DOI: http://dx.doi.org/10.7554/eLife.17828.001 PMID:27540631

  2. The mitochondrial acyl carrier protein (ACP) coordinates mitochondrial fatty acid synthesis with iron sulfur cluster biogenesis.

    PubMed

    Van Vranken, Jonathan G; Jeong, Mi-Young; Wei, Peng; Chen, Yu-Chan; Gygi, Steven P; Winge, Dennis R; Rutter, Jared

    2016-01-01

    Mitochondrial fatty acid synthesis (FASII) and iron sulfur cluster (FeS) biogenesis are both vital biosynthetic processes within mitochondria. In this study, we demonstrate that the mitochondrial acyl carrier protein (ACP), which has a well-known role in FASII, plays an unexpected and evolutionarily conserved role in FeS biogenesis. ACP is a stable and essential subunit of the eukaryotic FeS biogenesis complex. In the absence of ACP, the complex is destabilized resulting in a profound depletion of FeS throughout the cell. This role of ACP depends upon its covalently bound 4'-phosphopantetheine (4-PP)-conjugated acyl chain to support maximal cysteine desulfurase activity. Thus, it is likely that ACP is not simply an obligate subunit but also exploits the 4-PP-conjugated acyl chain to coordinate mitochondrial fatty acid and FeS biogenesis. PMID:27540631

  3. Characterizing parallel file-access patterns on a large-scale multiprocessor

    NASA Technical Reports Server (NTRS)

    Purakayastha, A.; Ellis, Carla; Kotz, David; Nieuwejaar, Nils; Best, Michael L.

    1995-01-01

    High-performance parallel file systems are needed to satisfy tremendous I/O requirements of parallel scientific applications. The design of such high-performance parallel file systems depends on a comprehensive understanding of the expected workload, but so far there have been very few usage studies of multiprocessor file systems. This paper is part of the CHARISMA project, which intends to fill this void by measuring real file-system workloads on various production parallel machines. In particular, we present results from the CM-5 at the National Center for Supercomputing Applications. Our results are unique because we collect information about nearly every individual I/O request from the mix of jobs running on the machine. Analysis of the traces leads to various recommendations for parallel file-system design.

  4. Simulating a small turboshaft engine in real-time multiprocessor simulator (RTMPS) environment

    NASA Technical Reports Server (NTRS)

    Milner, E. J.; Arpasi, D. J.

    1986-01-01

    A Real-Time Multiprocessor Simulator (RTMPS) has been developed at NASA Lewis Research Center. The RTMPS uses parallel microprocessors to achieve computing speeds needed for real-time engine simulation. This report describes the use of the RTMPS system to simulate a small turboshaft engine. The process of programming the engine equations and distributing them over one, two, and four processors is discussed. Steady-state and transient results from the RTMPS simulation are compared with results from a main-frame-based simulation. Processor execution times and the associated execution time savings for the two and four processor cases are presented using actual data obtained from the RTMPS system. Included is a discussion of why the minimum achievable calculation time for the turboshaft engine model was attained using four processors. Finally, future enhancements to the RTMPS system are discussed including the development of a generalized partitioning algorithm to automatically distribute the system equations among the processors in optimum fashion.

  5. Evaluation of the remineralization capacity of CPP-ACP containing fluoride varnish by different quantitative methods

    PubMed Central

    SAVAS, Selcuk; KAVRÌK, Fevzi; KUCUKYÌLMAZ, Ebru

    2016-01-01

    ABSTRACT Objective The aim of this study was to evaluate the efficacy of CPP-ACP containing fluoride varnish for remineralizing white spot lesions (WSLs) with four different quantitative methods. Material and Methods Four windows (3x3 mm) were created on the enamel surfaces of bovine incisor teeth. A control window was covered with nail varnish, and WSLs were created on the other windows (after demineralization, first week and fourth week) in acidified gel system. The test material (MI Varnish) was applied on the demineralized areas, and the treated enamel samples were stored in artificial saliva. At the fourth week, the enamel surfaces were tested by surface microhardness (SMH), quantitative light-induced fluorescence-digital (QLF-D), energy-dispersive spectroscopy (EDS) and laser fluorescence (LF pen). The data were statistically analyzed (α=0.05). Results While the LF pen measurements showed significant differences at baseline, after demineralization, and after the one-week remineralization period (p<0.05), the difference between the 1- and 4-week was not significant (p>0.05). With regards to the SMH and QLF-D analyses, statistically significant differences were found among all the phases (p<0.05). After the 1- and 4-week treatment periods, the calcium (Ca) and phosphate (P) concentrations and Ca/P ratio were higher compared to those of the demineralization surfaces (p<0.05). Conclusion CPP-ACP containing fluoride varnish provides remineralization of WSLs after a single application and seems suitable for clinical use. PMID:27383699

  6. Characterizing parallel file-access patterns on a large-scale multiprocessor

    NASA Technical Reports Server (NTRS)

    Purakayastha, Apratim; Ellis, Carla Schlatter; Kotz, David; Nieuwejaar, Nils; Best, Michael

    1994-01-01

    Rapid increases in the computational speeds of multiprocessors have not been matched by corresponding performance enhancements in the I/O subsystem. To satisfy the large and growing I/O requirements of some parallel scientific applications, we need parallel file systems that can provide high-bandwidth and high-volume data transfer between the I/O subsystem and thousands of processors. Design of such high-performance parallel file systems depends on a thorough grasp of the expected workload. So far there have been no comprehensive usage studies of multiprocessor file systems. Our CHARISMA project intends to fill this void. The first results from our study involve an iPSC/860 at NASA Ames. This paper presents results from a different platform, the CM-5 at the National Center for Supercomputing Applications. The CHARISMA studies are unique because we collect information about every individual read and write request and about the entire mix of applications running on the machines. The results of our trace analysis lead to recommendations for parallel file system design. First the file system should support efficient concurrent access to many files, and I/O requests from many jobs under varying load conditions. Second, it must efficiently manage large files kept open for long periods. Third, it should expect to see small requests predominantly sequential access patterns, application-wide synchronous access, no concurrent file-sharing between jobs appreciable byte and block sharing between processes within jobs, and strong interprocess locality. Finally, the trace data suggest that node-level write caches and collective I/O request interfaces may be useful in certain environments.

  7. Development and evaluation of a Fault-Tolerant Multiprocessor (FTMP) computer. Volume 2: FTMP software

    NASA Technical Reports Server (NTRS)

    Lala, J. H.; Smith, T. B., III

    1983-01-01

    The software developed for the Fault-Tolerant Multiprocessor (FTMP) is described. The FTMP executive is a timer-interrupt driven dispatcher that schedules iterative tasks which run at 3.125, 12.5, and 25 Hz. Major tasks which run under the executive include system configuration control, flight control, and display. The flight control task includes autopilot and autoland functions for a jet transport aircraft. System Displays include status displays of all hardware elements (processors, memories, I/O ports, buses), failure log displays showing transient and hard faults, and an autopilot display. All software is in a higher order language (AED, an ALGOL derivative). The executive is a fully distributed general purpose executive which automatically balances the load among available processor triads. Provisions for graceful performance degradation under processing overload are an integral part of the scheduling algorithms.

  8. Sequoia: A fault-tolerant tightly coupled multiprocessor for transaction processing

    SciTech Connect

    Bernstein, P.A.

    1988-02-01

    The Sequoia computer is a tightly coupled multiprocessor, and thus attains the performance advantages of this style of architecture. It avoids most of the fault-tolerance disadvantages of tight coupling by using a new fault-tolerance design. The Sequoia architecture is similar to other multimicroprocessor architectures, such as those of Encore and Sequent, in that it gives dozens of microprocessors shared access to a large main memory. It resembles the Stratus architecture in its extensive use of hardware fault-detection techniques. It resembles Stratus and Auragen in its ability to quickly recover all processes after a single point failure, transparently to the user. However, Sequoia is unique in its combination of a large-scale tightly coupled architecture with a hardware approach to fault tolerance. This article gives an overview of how the hardware architecture and operating systems (OS) work together to provide a high degree of fault tolerance with good system performance.

  9. Fault-free validation of a fault-tolerant multiprocessor: Baseline experiments and workoad implementation

    NASA Technical Reports Server (NTRS)

    Feather, F.; Siewiorek, D.; Segall, Z.

    1986-01-01

    In the future, aircraft employing active control technology must use highly reliable multiprocessors in order to achieve flight safety. Such computers must be experimentally validated before they are deployed. This project outlines a methodology for doing fault-free validation of reliable multiprocessors. The methodology begins with baseline experiments, which test single phenomenon. As experiments progress, tools for performance testing are developed. This report presents the results of interrupt baseline experiments performed on the Fault-Tolerant Multiprocessor (FTMP) at NASA-Langley's AIRLAB. Interrupt-causing excepting conditions were tested, and several were found to have unimplemented interrupt handling software while one had an unimplemented interrupt vector. A synthetic workload model for realtime multiprocessors is then developed as an application level performance analysis tool. Details of the workload implementation and calibration are presented. Both the experimental methodology and the synthetic workload model are general enough to be applicable to reliable multi-processors besides FTMP.

  10. A reconfigurable optoelectronic interconnect technology for multi-processor networks

    SciTech Connect

    Lu, Y.C.; Cheng, J.; Zolper, J.C.; Klem, J.

    1995-05-01

    This paper describes a new optical interconnect architecture and the integrated optoelectronic circuit technology for implementing a parallel, reconfigurable, multiprocessor network. The technology consists of monolithic array`s of optoelectronic switches that integrate vertical-cavity surface-emitting lasers with three-terminal heterojunction phototransistors, which effectively combined the functions of an optical transceiver and an optical spatial routing switch. These switches have demonstrated optical switching at 200 Mb/s, and electrical-to-optical data conversion at > 500 Mb/s, with a small-signal electrical-to-optical modulation bandwidth of {approximately} 4 GHz.

  11. Multiprocessor data acquisition for NordBall

    NASA Astrophysics Data System (ADS)

    Jerrestam, Dan; Forycki, A.; Holm, A.; Høy-Christensen, P.; Jian Shen, T.

    1989-12-01

    For the NordBall multidetector system a versatile data acquisition system has been developed around the VME bus utilizing 68010 processors. The readout of the instrument is based on a generalized READER concept. READERs are CPU boards reading hardware in parallel for each event. In the FERA bus the final fast logical decision is made before an event is to be considered as being present for readout. Synchronization with the trigger for readout, coming from the FERA bus system, is performed by a special hardware unit. Synchronization on event level between the READERs is done by the same hardware unit monitored by a master CPU.

  12. Efficient ICCG on a shared memory multiprocessor

    NASA Technical Reports Server (NTRS)

    Hammond, Steven W.; Schreiber, Robert

    1989-01-01

    Different approaches are discussed for exploiting parallelism in the ICCG (Incomplete Cholesky Conjugate Gradient) method for solving large sparse symmetric positive definite systems of equations on a shared memory parallel computer. Techniques for efficiently solving triangular systems and computing sparse matrix-vector products are explored. Three methods for scheduling the tasks in solving triangular systems are implemented on the Sequent Balance 21000. Sample problems that are representative of a large class of problems solved using iterative methods are used. We show that a static analysis to determine data dependences in the triangular solve can greatly improve its parallel efficiency. We also show that ignoring symmetry and storing the whole matrix can reduce solution time substantially.

  13. A partitioning strategy for efficient nonlinear finite element dynamic analysis on multiprocessor computer

    NASA Technical Reports Server (NTRS)

    Noor, Ahmed K.; Peters, Jeanne M.

    1989-01-01

    A computational procedure is presented for the nonlinear dynamic analysis of unsymmetric structures on vector multiprocessor systems. The procedure is based on a novel hierarchical partitioning strategy in which the response of the unsymmetric and antisymmetric response vectors (modes), each obtained by using only a fraction of the degrees of freedom of the original finite element model. The three key elements of the procedure which result in high degree of concurrency throughout the solution process are: (1) mixed (or primitive variable) formulation with independent shape functions for the different fields; (2) operator splitting or restructuring of the discrete equations at each time step to delineate the symmetric and antisymmetric vectors constituting the response; and (3) two level iterative process for generating the response of the structure. An assessment is made of the effectiveness of the procedure on the CRAY X-MP/4 computers.

  14. Partitioning strategy for efficient nonlinear finite element dynamic analysis on multiprocessor computers

    NASA Technical Reports Server (NTRS)

    Noor, Ahmed K.; Peters, Jeanne M.

    1989-01-01

    A computational procedure is presented for the nonlinear dynamic analysis of unsymmetric structures on vector multiprocessor systems. The procedure is based on a novel hierarchical partitioning strategy in which the response of the unsymmetric and antisymmetric response vectors (modes), each obtained by using only a fraction of the degrees of freedom of the original finite element model. The three key elements of the procedure which result in high degree of concurrency throughout the solution process are: (1) mixed (or primitive variable) formulation with independent shape functions for the different fields; (2) operator splitting or restructuring of the discrete equations at each time step to delineate the symmetric and antisymmetric vectors constituting the response; and (3) two level iterative process for generating the response of the structure. An assessment is made of the effectiveness of the procedure on the CRAY X-MP/4 computers.

  15. Resource Management for Distributed Parallel Systems

    NASA Technical Reports Server (NTRS)

    Neuman, B. Clifford; Rao, Santosh

    1993-01-01

    Multiprocessor systems should exist in the the larger context of distributed systems, allowing multiprocessor resources to be shared by those that need them. Unfortunately, typical multiprocessor resource management techniques do not scale to large networks. The Prospero Resource Manager (PRM) is a scalable resource allocation system that supports the allocation of processing resources in large networks and multiprocessor systems. To manage resources in such distributed parallel systems, PRM employs three types of managers: system managers, job managers, and node managers. There exist multiple independent instances of each type of manager, reducing bottlenecks. The complexity of each manager is further reduced because each is designed to utilize information at an appropriate level of abstraction.

  16. Low latency messages on distributed memory multiprocessors

    NASA Technical Reports Server (NTRS)

    Rosing, Matthew; Saltz, Joel

    1993-01-01

    Many of the issues in developing an efficient interface for communication on distributed memory machines are described and a portable interface is proposed. Although the hardware component of message latency is less than one microsecond on many distributed memory machines, the software latency associated with sending and receiving typed messages is on the order of 50 microseconds. The reason for this imbalance is that the software interface does not match the hardware. By changing the interface to match the hardware more closely, applications with fine grained communication can be put on these machines. Based on several tests that were run on the iPSC/860, an interface that will better match current distributed memory machines is proposed. The model used in the proposed interface consists of a computation processor and a communication processor on each node. Communication between these processors and other nodes in the system is done through a buffered network. Information that is transmitted is either data or procedures to be executed on the remote processor. The dual processor system is better suited for efficiently handling asynchronous communications compared to a single processor system. The ability to send data or procedure is very flexible for minimizing message latency, based on the type of communication being performed. The test performed and the proposed interface are described.

  17. Experience with a Genetic Algorithm Implemented on a Multiprocessor Computer

    NASA Technical Reports Server (NTRS)

    Plassman, Gerald E.; Sobieszczanski-Sobieski, Jaroslaw

    2000-01-01

    Numerical experiments were conducted to find out the extent to which a Genetic Algorithm (GA) may benefit from a multiprocessor implementation, considering, on one hand, that analyses of individual designs in a population are independent of each other so that they may be executed concurrently on separate processors, and, on the other hand, that there are some operations in a GA that cannot be so distributed. The algorithm experimented with was based on a gaussian distribution rather than bit exchange in the GA reproductive mechanism, and the test case was a hub frame structure of up to 1080 design variables. The experimentation engaging up to 128 processors confirmed expectations of radical elapsed time reductions comparing to a conventional single processor implementation. It also demonstrated that the time spent in the non-distributable parts of the algorithm and the attendant cross-processor communication may have a very detrimental effect on the efficient utilization of the multiprocessor machine and on the number of processors that can be used effectively in a concurrent manner. Three techniques were devised and tested to mitigate that effect, resulting in efficiency increasing to exceed 99 percent.

  18. Expression and specificity profile of the major acetate transporter AcpA in Aspergillus nidulans.

    PubMed

    Sá-Pessoa, Joana; Amillis, Sotiris; Casal, Margarida; Diallinas, George

    2015-03-01

    AcpA has been previously characterized as a high-affinity transporter essential for the uptake and use of acetate as sole carbon source in Aspergillus nidulans. Here, we follow the expression profile of AcpA and define its substrate specificity. AcpA-mediated acetate transport is detected from the onset of conidiospore germination, peaks at the time of germ tube emergence, and drops to low basal levels in germlings and young mycelia, where a second acetate transporter is also becoming apparent. AcpA activity also responds to acetate presence in the growth medium, but is not subject to either carbon or nitrogen catabolite repression. Short-chain monocarboxylates (benzoate, formate, butyrate and propionate) inhibit AcpA-mediated acetate transport with apparent inhibition constants (Ki) of 16.89±2.12, 9.25±1.01, 12.06±3.29 and 1.44±0.13mM, respectively. AcpA is also shown not to be directly involved in ammonia export, as proposed for its Saccharomyces cerevisiae homologue Ady2p. In the second part of this work, we search for the unknown acetate transporter expressed in mycelia, and for other transporters that might contribute to acetate uptake. In silico analysis, genetic construction of relevant null mutants, and uptake assays, reveal that the closest AcpA homologue (AN1839), named AcpB, is the 'missing' secondary acetate transporter in mycelia. We also identify two major short-chain carboxylate (lactate, succinate, pyruvate and malate) transporters, named JenA (AN6095) and JenB (AN6703), which however are not involved in acetate uptake. This work establishes a framework for further exploiting acetate and carboxylate transport in filamentous ascomycetes. PMID:25708319

  19. Efficient free fatty acid production in Escherichia coli using plant acyl-ACP thioesterases.

    PubMed

    Zhang, Xiujun; Li, Mai; Agrawal, Arpita; San, Ka-Yiu

    2011-11-01

    Microbial biosynthesis of fatty acid-like chemicals from renewable carbon sources has attracted significant attention in recent years. Free fatty acids can be used as precursors for the production of fuels or chemicals. Free fatty acids can be produced by introducing an acyl-acyl carrier protein thioesterase gene into Escherichia coli. The presence of the acyl-ACP thioesterase will break the fatty acid elongation cycle and release free fatty acid. Depending on their sequence similarity and substrate specificity, class FatA thioesterase is active on unsaturated acyl-ACPs and class FatB prefers saturated acyl group. Different acyl-ACP thioesterases have different degrees of chain length specificity. Although some of these enzymes have been characterized from a number of sources, information on their ability to produce free fatty acid in microbial cells has not been extensively examined until recently. In this study, we examined the effect of the overexpression of acyl-ACP thioesterase genes from Diploknema butyracea, Gossypium hirsutum, Ricinus communis and Jatropha curcas on free fatty acid production. In particular, we are interested in studying the effect of different acyl-ACP thioesterase on the quantities and compositions of free fatty acid produced by an E. coli strain ML103 carrying these constructs. It is shown that the accumulation of free fatty acid depends on the acyl-ACP thioesterase used. The strain carrying the acyl-ACP thioesterase gene from D. butyracea produced approximately 0.2g/L of free fatty acid while the strains carrying the acyl-ACP thioesterase genes from R. communis and J. curcas produced the most free fatty acid at a high level of more than 2.0 g/L at 48 h. These two strains accumulated three major straight chain free fatty acids, C14, C16:1 and C16 at levels about 40%, 35% and 20%, respectively. PMID:22001432

  20. The chain-flipping mechanism of ACP (acyl carrier protein)-dependent enzymes appears universal.

    PubMed

    Cronan, John E

    2014-06-01

    ACPs (acyl carrier proteins) play essential roles in the synthesis of fatty acids, polyketides and non-ribosomal polypeptides. ACP function requires the modification of the protein by attachment of 4'-phosphopantetheine to a conserved serine residue. The phosphopantetheine thiol acts to tether the starting materials and intermediates as their thioesters. ACPs are small highly soluble proteins composed of four α-helices. The helices form a bundle that acts as a hydrophobic sleeve that sequesters the acyl chains and activated thioesters from solvent. However, in the synthesis of fatty acids and complex lipids the enzymes of the pathway must access the thioester and the proximal carbon atoms in order to perform the needed chemistry. How such access is provided without exposure of the acyl chains to solvent has been a longstanding question due to the lack of acyl-ACP-enzyme complexes, a situation generally attributed to the brevity of the interactions of acyl-ACPs with their cognate enzymes. As discussed in the present review the access question has now been answered by four recent crystal structures, each of which shows that the entire acyl chain plus the 4'-phosphopantetheine prosthetic group partitions from the ACP hydrophobic sleeve into a hydrophobic pocket or groove of the enzyme protein, a process termed chain flipping. PMID:24825445

  1. Solution of the Euler and Navier-Stokes equations on MIMD distributed memory multiprocessors using cyclic reduction

    SciTech Connect

    Curchitser, E.N.; Pelz, R.B.; Marconi, F. Grumman Aerospace Corp., Bethpage, NY )

    1992-01-01

    The Euler and Navier-Stokes equations are solved for the steady, two-dimensional flow over a NACA 0012 airfoil using a 1024 node nCUBE/2 multiprocessor. Second-order, upwind-discretized difference equations are solved implicitly using ADI factorization. Parallel cyclic reduction is employed to solve the block tridiagonal systems. For realistic problems, communication times are negligible compared to calculation times. The processors are tightly synchronized, and their loads are well balanced. When the flux Jacobians flux are frozen, the wall-clock time for one implicit timestep is about equal to that of a multistage explicit scheme. 10 refs.

  2. Characterization of soluble acyl-ACP desaturases from Camelina sativa, Macadamia tetraphylla and Dolichandra unguis-cati.

    PubMed

    Rodríguez, Manuel Fernando Rodríguez; Sánchez-García, Alicia; Salas, Joaquín J; Garcés, Rafael; Martínez-Force, Enrique

    2015-04-15

    Acyl-acyl carrier protein (ACP) desaturases (EC 1.14.19.2) are soluble enzymes that catalyse the insertion of a double bond into saturated fatty acid bound in saturated acyl chains bound to ACP in higher plants, producing cis-monounsaturated fatty acids. Three types of soluble acyl-ACP desaturases have been described: Δ(9)-acyl-ACP, Δ(6)-acyl-ACP and Δ(4)-acyl-ACP desaturases, which differ in the substrate specificity and the position in which the double bond is introduced. In the present work, Camelina sativa (CsSAD), Macadamia tetraphylla (MtSAD) and Dolichandra unguis-cati (DuSAD) desaturases were cloned, sequenced and characterized. Single copies of CsSAD, MtSAD and DuSAD with three, one and two different alleles, respectively, were found. The corresponding mature proteins were heterologously expressed in Escherichia coli for biochemical characterization in protein extracts. The recombinant CsSAD enzyme showed 300-fold higher specificity towards 18:0-ACP than 16:0-ACP. Similar profile exhibited MtSAD although the differences in the specificity were lower, around 170-fold higher for 18:0-ACP than 16:0-ACP. Furthermore, DuSAD presented a profile showing preference towards 16:0-ACP against 18:0-ACP, around twice more, being so a Δ(9) palmitoyl-ACP desaturase. Also, we reported the expression profile of CsSAD, which showed the highest levels of expression in expanding tissues that typically are very active in lipid biosynthesis such as developing seed endosperm. Moreover, the possibility to express a new desaturase in C. sativa (oilseed crop that store high levels of oil and is easy to transform) to create a new line rich in short monounsaturated fatty acid is discussed. PMID:25765361

  3. Parallel algorithm of VLBI software correlator under multiprocessor environment

    NASA Astrophysics Data System (ADS)

    Zheng, Weimin; Zhang, Dong

    2007-11-01

    The correlator is the key signal processing equipment of a Very Lone Baseline Interferometry (VLBI) synthetic aperture telescope. It receives the mass data collected by the VLBI observatories and produces the visibility function of the target, which can be used to spacecraft position, baseline length measurement, synthesis imaging, and other scientific applications. VLBI data correlation is a task of data intensive and computation intensive. This paper presents the algorithms of two parallel software correlators under multiprocessor environments. A near real-time correlator for spacecraft tracking adopts the pipelining and thread-parallel technology, and runs on the SMP (Symmetric Multiple Processor) servers. Another high speed prototype correlator using the mixed Pthreads and MPI (Massage Passing Interface) parallel algorithm is realized on a small Beowulf cluster platform. Both correlators have the characteristic of flexible structure, scalability, and with 10-station data correlating abilities.

  4. Discovery of an Allosteric Inhibitor Binding Site in 3-Oxo-acyl-ACP Reductase from Pseudomonas aeruginosa

    PubMed Central

    2013-01-01

    3-Oxo-acyl-acyl carrier protein (ACP) reductase (FabG) plays a key role in the bacterial fatty acid synthesis II system in pathogenic microorganisms, which has been recognized as a potential drug target. FabG catalyzes reduction of a 3-oxo-acyl-ACP intermediate during the elongation cycle of fatty acid biosynthesis. Here, we report gene deletion experiments that support the essentiality of this gene in P. aeruginosa and the identification of a number of small molecule FabG inhibitors with IC50 values in the nanomolar to low micromolar range and good physicochemical properties. Structural characterization of 16 FabG-inhibitor complexes by X-ray crystallography revealed that the compounds bind at a novel allosteric site located at the FabG subunit–subunit interface. Inhibitor binding relies primarily on hydrophobic interactions, but specific hydrogen bonds are also observed. Importantly, the binding cavity is formed upon complex formation and therefore would not be recognized by virtual screening approaches. The structure analysis further reveals that the inhibitors act by inducing conformational changes that propagate to the active site, resulting in a displacement of the catalytic triad and the inability to bind NADPH. PMID:24015914

  5. Effect of CPP/ACP on initial bioadhesion to enamel and dentin in situ.

    PubMed

    Grychtol, Susann; Basche, Sabine; Hannig, Matthias; Hannig, Christian

    2014-01-01

    The present in situ study investigated the influence of a preparation containing CPP/ACP (caseinphosphopeptide-amorphous calcium phosphate) (GC Tooth mousse) on initial bacterial colonization of enamel and dentin. Therefore, pellicle formation was performed in situ on bovine enamel and dentin specimens fixed to individual upper jaw splints worn by 8 subjects. After 1 min of pellicle formation GC Tooth mousse was used according to manufacturer's recommendations. Rinses with chlorhexidine served as positive controls. Specimens carried without any rinse served as negative controls. After 8 h overnight exposure of the splints, bacterial colonization was quantified by fluorescence microscopy (DAPI and BacLight live/dead staining). Additionally, the colony forming units (CFU) were determined after desorption. Furthermore, the effects on Streptococcus mutans bacteria were tested in vitro (BacLight). There was no significant impact of CPP/ACP on initial bacterial colonization proved with DAPI and BacLight. Determination of CFU showed statistical significance for CPP/ACP to reduce bacterial adherence on enamel. The in vitro investigation indicated no antimicrobial effects for CPP/ACP on Streptococcus mutans suspension. Under the chosen conditions, CPP/ACP (GC Tooth mousse) had no significant impact on initial biofilm formation on dental hard tissues. The tested preparation cannot be recommended for biofilm management. PMID:25386603

  6. Effect of CPP/ACP on Initial Bioadhesion to Enamel and Dentin In Situ

    PubMed Central

    2014-01-01

    The present in situ study investigated the influence of a preparation containing CPP/ACP (caseinphosphopeptide-amorphous calcium phosphate) (GC Tooth mousse) on initial bacterial colonization of enamel and dentin. Therefore, pellicle formation was performed in situ on bovine enamel and dentin specimens fixed to individual upper jaw splints worn by 8 subjects. After 1 min of pellicle formation GC Tooth mousse was used according to manufacturer's recommendations. Rinses with chlorhexidine served as positive controls. Specimens carried without any rinse served as negative controls. After 8 h overnight exposure of the splints, bacterial colonization was quantified by fluorescence microscopy (DAPI and BacLight live/dead staining). Additionally, the colony forming units (CFU) were determined after desorption. Furthermore, the effects on Streptococcus mutans bacteria were tested in vitro (BacLight). There was no significant impact of CPP/ACP on initial bacterial colonization proved with DAPI and BacLight. Determination of CFU showed statistical significance for CPP/ACP to reduce bacterial adherence on enamel. The in vitro investigation indicated no antimicrobial effects for CPP/ACP on Streptococcus mutans suspension. Under the chosen conditions, CPP/ACP (GC Tooth mousse) had no significant impact on initial biofilm formation on dental hard tissues. The tested preparation cannot be recommended for biofilm management. PMID:25386603

  7. Efficacious long-term cooling and freezing of Sapajus apella semen in ACP-118(®).

    PubMed

    Leão, D L; Miranda, S A; Brito, A B; Lima, J S; Santos, R R; Domingues, S F S

    2015-08-01

    The objectives of the present study were to test the effect of coconut water solution (CWS), TES-TRIS and ACP-118(®) on the seminal cooling and cryopreservation of semen from capuchin monkeys (Sapajus apella). Semen was collected from six males by electro-ejaculation, diluted in TES-TRIS, CWS or ACP-118(®), and maintained at 4°C for 28h. Semen was subsequently evaluated (Experiment I) or cryopreserved in the presence of different glycerol concentrations (3%, 5% or 7%) (Experiment II). ACP-118(®) was the preferred extender to preserve sperm motility and viability after 28h incubation at 4°C. Cooled sperm were successfully frozen-thawed in a medium containing 3% glycerol. After thawing, sperm retained the capacity to fertilize oocytes and zygotes were obtained. In conclusion, ACP-118(®) can be effectively and efficiently used as extender for the cooling of S. apella semen. Furthermore, cryopreservation using ACP-118(®) by adding 3% glycerol is suitable to maintain sperm morphology and the capacity of these cells to fertilize in vitro. PMID:26071650

  8. iACP: a sequence-based tool for identifying anticancer peptides

    PubMed Central

    Chen, Wei; Ding, Hui; Feng, Pengmian; Lin, Hao; Chou, Kuo-Chen

    2016-01-01

    Cancer remains a major killer worldwide. Traditional methods of cancer treatment are expensive and have some deleterious side effects on normal cells. Fortunately, the discovery of anticancer peptides (ACPs) has paved a new way for cancer treatment. With the explosive growth of peptide sequences generated in the post genomic age, it is highly desired to develop computational methods for rapidly and effectively identifying ACPs, so as to speed up their application in treating cancer. Here we report a sequence-based predictor called iACP developed by the approach of optimizing the g-gap dipeptide components. It was demonstrated by rigorous cross-validations that the new predictor remarkably outperformed the existing predictors for the same purpose in both overall accuracy and stability. For the convenience of most experimental scientists, a publicly accessible web-server for iACP has been established at http://lin.uestc.edu.cn/server/iACP, by which users can easily obtain their desired results. PMID:26942877

  9. [Constructing an ACP Simulation-Situation Communication Training Program for Patients With Chronic Kidney Disease].

    PubMed

    Chen, Jui-O; Lin, Chiu-Chu

    2016-06-01

    The aging population and changing lifestyles have lead to the increased general risk of chronic kidney disease. Taiwan currently has the highest incidence and prevalence of end-stage renal disease (ESRD) of any country or region in the world. Hemodialysis patients must endure comorbidities and face the uncertainties of death. The best way to achieve a good death is for patients to sign advance care planning (ACP). However, the key factors contributing to low ACP signature rates have been the lack of communication skills and related training among medical staffs. This article explores the dilemma of ACP using an example of chronic kidney disease (CKD) and proposes a theory-based approach to develop a theoretical framework for an ACP simulation-situation communication training program that integrates the simulation situation model, PREPARED model, and scaffolding theory. Readers may use this framework to design ACP simulation-situation communication training programs that conform to their own conditions and then test the effectiveness and feasibility of these programs in clinical settings. PMID:27250964

  10. Multi-processor developments in the United States for future high energy physics experiments and accelerators

    SciTech Connect

    Gaines, I.

    1988-03-01

    The use of multi-processors for analysis and high-level triggering in High Energy Physics experiments, pioneered by the early emulator systems, has reached maturity, in particular with the multiple microprocessor systems in use at Fermilab. It is widely acknowledged that such systems will fulfill the major portion of the computing needs of future large experiments. Recent developments at Fermilab's Advanced Computer Program will make such systems even more powerful, cost-effective, and easier to use than they are at present. The next generation of microprocessors, already available, will provide CPU power of about one VAX 780 equivalent/$300, while supporting most VMS FORTRAN extensions and large (>8MB) amounts of memory. Low cost high density mass storage devices (based on video tape cartridge technology) will allow parallel I/O to remove potential I/O bottlenecks in systems of over 1000 VAX equipment processors. New interconnection schemes and system software will allow more flexible topologies and extremely high data bandwidth, especially for on-line systems. This talk will summarize the work at the Advanced Computer Program and the rest of the US in this field. 3 refs., 4 figs.

  11. Exploring the use of I/O nodes for computation in a MIMD multiprocessor

    NASA Technical Reports Server (NTRS)

    Kotz, David; Cai, Ting

    1995-01-01

    As parallel systems move into the production scientific-computing world, the emphasis will be on cost-effective solutions that provide high throughput for a mix of applications. Cost effective solutions demand that a system make effective use of all of its resources. Many MIMD multiprocessors today, however, distinguish between 'compute' and 'I/O' nodes, the latter having attached disks and being dedicated to running the file-system server. This static division of responsibilities simplifies system management but does not necessarily lead to the best performance in workloads that need a different balance of computation and I/O. Of course, computational processes sharing a node with a file-system service may receive less CPU time, network bandwidth, and memory bandwidth than they would on a computation-only node. In this paper we begin to examine this issue experimentally. We found that high performance I/O does not necessarily require substantial CPU time, leaving plenty of time for application computation. There were some complex file-system requests, however, which left little CPU time available to the application. (The impact on network and memory bandwidth still needs to be determined.) For applications (or users) that cannot tolerate an occasional interruption, we recommend that they continue to use only compute nodes. For tolerant applications needing more cycles than those provided by the compute nodes, we recommend that they take full advantage of both compute and I/O nodes for computation, and that operating systems should make this possible.

  12. Radiosynthesis and biological evaluation of a novel enoyl-ACP reductase inhibitor for Staphylococcus aureus

    DOE PAGESBeta

    Wang, Hui; Lu, Yang; Liu, Li; Kim, Sung Won; Hooker, Jacob M.; Fowler, Joanna S.; Tonge, Peter J.

    2014-09-06

    Here we evaluated the pharmacokinetics (PK) and pharmacodynamics (PD) of PT119, a potent Staphylococcus aureus enoyl-ACP reductase (saFabI) inhibitor with a Ki value of 0.01 nM and a residence time of 750 min on the enzyme target in mice. PT119 was found to have promising antibacterial activity in two different S. aureus infection models: it caused a 3 log reduction in the CFU’s in a mouse thigh muscle infection model and increased the survival rate from 0% to 50% in a mouse systemic infection model. PT119 was then radiolabeled with carbon-11 to evaluate its biodistribution and PK in both healthymore » and S. aureus infected mice using positron emission tomography (PET). The biodistribution of [11C]PT119 and/or its labeled metabolites did not differ significantly between the healthy group and the infected group, and PT119 was found to distribute equally between serum and tissue during the ~1 h of analysis permitted by the carbon-11 half life. This approach provides important data for PK/PD modeling and is the first step in identifying radiotracers that can non-invasively image bacterial infection in vivo.« less

  13. Radiosynthesis and biological evaluation of a novel enoyl-ACP reductase inhibitor for Staphylococcus aureus

    SciTech Connect

    Wang, Hui; Lu, Yang; Liu, Li; Kim, Sung Won; Hooker, Jacob M.; Fowler, Joanna S.; Tonge, Peter J.

    2014-09-06

    Here we evaluated the pharmacokinetics (PK) and pharmacodynamics (PD) of PT119, a potent Staphylococcus aureus enoyl-ACP reductase (saFabI) inhibitor with a Ki value of 0.01 nM and a residence time of 750 min on the enzyme target in mice. PT119 was found to have promising antibacterial activity in two different S. aureus infection models: it caused a 3 log reduction in the CFU’s in a mouse thigh muscle infection model and increased the survival rate from 0% to 50% in a mouse systemic infection model. PT119 was then radiolabeled with carbon-11 to evaluate its biodistribution and PK in both healthy and S. aureus infected mice using positron emission tomography (PET). The biodistribution of [11C]PT119 and/or its labeled metabolites did not differ significantly between the healthy group and the infected group, and PT119 was found to distribute equally between serum and tissue during the ~1 h of analysis permitted by the carbon-11 half life. This approach provides important data for PK/PD modeling and is the first step in identifying radiotracers that can non-invasively image bacterial infection in vivo.

  14. Advanced spent fuel conditioning process (ACP) progress with respect to remote operation and maintenance

    SciTech Connect

    Lee, Hyo Jik; Lee, Jong Kwang; Park, Byung Suk; Yoon, Ji Sup

    2007-07-01

    Korea Atomic Energy Research Institute (KAERI) has been developing an Advanced Spent Fuel Conditioning Process (ACP) to reduce the volume of spent fuel, and the construction of the ACP facility (ACPF) for a demonstration of its technical feasibility has been completed. In 2006 two inactive demonstrations were performed with simulated fuels in the ACPF. Accompanied by process equipment performance tests, its remote operability and maintainability were also tested during that time. Procedures for remote operation tasks are well addressed in this study and evaluated thoroughly. Also, remote maintenance and repair tasks are addressed regarding some important modules with a high priority order. The above remote handling test's results provided a lot of information such as items to be revised to improve the efficiency of the remote handling tasks. This paper deals with the current status of ACP and the progress of remote handling of ACPF. (authors)

  15. Stacking of a stearoyl-ACP thioesterase with a dual-silenced palmitoyl-ACP thioesterase and ∆12 fatty acid desaturase in transgenic soybean.

    PubMed

    Park, Hyunwoo; Graef, George; Xu, Yixiang; Tenopir, Patrick; Clemente, Tom E

    2014-10-01

    Soybean (Glycine max (L.) Merr) is valued for both its protein and oil, whose seed is composed of 40% and 20% of each component, respectively. Given its high percentage of polyunsaturated fatty acids, linoleic acid and linolenic acid, soybean oil oxidative stability is relatively poor. Historically food processors have employed a partial hydrogenation process to soybean oil as a means to improve both the oxidative stability and functionality in end-use applications. However, the hydrogenation process leads to the formation of trans-fats, which are associated with negative cardiovascular health. As a means to circumvent the need for the hydrogenation process, genetic approaches are being pursued to improve oil quality in oilseeds. In this regard, we report here on the introduction of the mangosteen (Garcinia mangostana) stearoyl-ACP thioesterase into soybean and the subsequent stacking with an event that is dual-silenced in palmitoyl-ACP thioesterase and ∆12 fatty acid desaturase expression in a seed-specific fashion. Phenotypic analyses on transgenic soybean expressing the mangosteen stearoyl-ACP thioesterase revealed increases in seed stearic acid levels up to 17%. The subsequent stacked with a soybean event silenced in both palmitoyl-ACP thioesterase and ∆12 fatty acid desaturase activity, resulted in a seed lipid phenotype of approximately 11%-19% stearate and approximately 70% oleate. The oil profile created by the stack was maintained for four generations under greenhouse conditions and a fifth generation under a field environment. However, in generation six and seven under field conditions, the oleate levels decreased to 30%-40%, while the stearic level remained elevated. PMID:24909647

  16. USGS tethered ACP platforms: New design means more safety and accuracy

    USGS Publications Warehouse

    Morlock, S.E.; Stewart, J.A.; Rehmel, M.S.

    2004-01-01

    The US Geological Survey has developed an innovative tethered platform that supports an Acoustic Current Profiler (ACP) in making stream-flow measurements (use of the term ACP in this article refers to a class of instruments and not a specific brand name or model). The tethered platform reduces the hazards involved in conventional methods of stream-flow measurement. The use of the platform reduces or eliminates time spent by personnel in streams and boats or on bridges and cableway and stream-flow measurement accuracy is increased.

  17. Development and evaluation of a Fault-Tolerant Multiprocessor (FTMP) computer. Volume 3: FTMP test and evaluation

    NASA Technical Reports Server (NTRS)

    Lala, J. H.; Smith, T. B., III

    1983-01-01

    The experimental test and evaluation of the Fault-Tolerant Multiprocessor (FTMP) is described. Major objectives of this exercise include expanding validation envelope, building confidence in the system, revealing any weaknesses in the architectural concepts and in their execution in hardware and software, and in general, stressing the hardware and software. To this end, pin-level faults were injected into one LRU of the FTMP and the FTMP response was measured in terms of fault detection, isolation, and recovery times. A total of 21,055 stuck-at-0, stuck-at-1 and invert-signal faults were injected in the CPU, memory, bus interface circuits, Bus Guardian Units, and voters and error latches. Of these, 17,418 were detected. At least 80 percent of undetected faults are estimated to be on unused pins. The multiprocessor identified all detected faults correctly and recovered successfully in each case. Total recovery time for all faults averaged a little over one second. This can be reduced to half a second by including appropriate self-tests.

  18. Multiprocessor architecture to handle TJ-II VXI-based digitization channels

    NASA Astrophysics Data System (ADS)

    Crémy, C.; Vega, J.; Sánchez, E.; Dulya, C. M.; Portas, A.

    1999-01-01

    The data acquisition System (DAS) of the TJ-II stellerator provides up to 300 digitization channels integrated in register-based VXI modules designed in CIEMAT Laboratories. The modules are embedded into six 13-slot VXI chassis connected to the TJ-II DAS central computer by means of a dual LAN topology. During normal operation, remote control of the VXI systems and channel setup are accomplished through an Ethernet LAN, while two FDDI rings are dedicated to postdischarge fast data transfer. The former network link is performed by the bus controller whereas the latter one is provided through a FDDI node controller installed in the mainframe, thus creating a multiprocessor architecture. Dedicated software, running on the VxWorks operating system, has been developed to provide handling of the VXI systems including the following facilities: mainframe information readout, channel setup, real time digitization handling, and data transfer. This software, implemented in C++, is distributed over the two CPUs. Interprocessor communication for synchronization purposes is based on a backplane shared memory pool.

  19. Preparation of fatty-acylated derivatives of acyl carrier protein using Vibrio harveyi acyl-ACP synthetase.

    PubMed

    Shen, Z; Fice, D; Byers, D M

    1992-07-01

    A simple two-step purification of Vibrio harveyi fatty acyl-acyl carrier protein (acyl-ACP) synthetase, which is useful for the quantitative preparation and analysis of fatty-acylated derivatives of ACP, is described. Acyl-ACP synthetase can be partially purified from extracts of this bioluminescent bacterium by Cibacron blue chromatography and Sephacryl S-300 gel filtration and is stable for months at -20 degrees C in the presence of glycerol. Incubation of ACP from Escherichia coli with ATP and radiolabeled fatty acids (6 to 16 carbons in length) in the presence of the enzyme resulted in quantitative conversion to biologically active acylated derivatives. The enzyme reaction can be monitored by a filter disk assay to quantitate levels of ACP or by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and fluorography to detect ACP in cell extracts. With its broad fatty acid chain length specificity and optimal activity in mild nondenaturing buffers, the soluble V. harveyi acyl-ACP synthetase provides an attractive alternative to current chemical and enzymatic methods of acyl-ACP preparation and analysis. PMID:1514693

  20. Solutions and debugging for data consistency in multiprocessors with noncoherent caches

    SciTech Connect

    Bernstein, D.; Mendelson, B.; Breternitz, M. Jr.; Gheith, A.M.

    1995-02-01

    We analyze two important problems that arise in shared-memory multiprocessor systems. The stale data problem involves ensuring that data items in local memory of individual processors are current, independent of writes done by other processors. False sharing occurs when two processors have copies of the same shared data block but update different portions of the block. The false sharing problem involves guaranteeing that subsequent writes are properly combined. In modern architectures these problems are usually solved in hardware, by exploiting mechanisms for hardware controlled cache consistency. This leads to more expensive and nonscalable designs. Therefore, we are concentrating on software methods for ensuring cache consistency that would allow for affordable and scalable multiprocessing systems. Unfortunately, providing software control is nontrivial, both for the compiler writer and for the application programmer. For this reason we are developing a debugging environment that will facilitate the development of compiler-based techniques and will help the programmer to tune his or her application using explicit cache management mechanisms. We extend the notion of a race condition for IBM Shared Memory System POWER/4, taking into consideration its noncoherent caches, and propose techniques for detection of false sharing problems. Identification of the stale data problem is discussed as well, and solutions are suggested.

  1. Solution of open region electromagnetic scattering problems on hypercube multiprocessors

    SciTech Connect

    Gedney, S.D.

    1991-01-01

    This thesis focuses on development of parallel algorithms that exploit hypercube multiprocessor computers for the solution of the scattering of electromagnetic fields by bodies situated in an unbounded space. Initially, algorithms based on the method of moments are investigated for coarse-grained MIMD hypercubes as well as finite-grained MIMD and SIMD hypercubes. It is shown that by exploiting the architecture of each hypercube, supercomputer performance can be obtained using the JPL Mark III hypercube and the Thinking Machine's CM2. Second, the use of the finite-element method for solution of the scattering by bodies of composite materials is presented. For finite bodies situated in an unbounded space, use of an absorbing boundary condition is investigated. A method known as the mixed-{chi} formulation is presented, which reduces the mesh density in the regions away from the scatterer, enhancing the use of an absorbing boundary condition. The scattering by troughs or slots is also investigated using a combined FEM/MoM formulation. This method is extended to the problem of the diffraction of electromagnetic waves by thick conducting and/or dielectric gratings. Finally, the adaptation of the FEM method onto a coarse-grained hypercube is presented.

  2. A New coscheduling technique for a cluster of symmetric multiprocessors

    SciTech Connect

    Yoo, A B; Jette, M A

    2000-04-17

    Coscheduling is essential for obtaining good performance in a time-shared symmetric multiprocessor (SMP) cluster environment. However, the most common technique, gang scheduling, has limitations such as poor scalability and vulnerability to faults mainly due to explicit synchronization between its components. A decentralized approach called dynamic coscheduling (DCS) has been shown to be effective for network of workstations (NOW), but this technique is not suitable for the workloads on a very large SMP-cluster with thousands of processors. Furthermore, its implementation can be prohibitively expensive for such a large-scale machine. In this paper, we propose a novel coscheduling technique based on the DCS approach which can achieve coscheduling on very large SMP-clusters in a scalable, efficient, and cost-effective way. In the proposed technique, each local scheduler achieves coscheduling based upon message traffic between the components of parallel jobs. Message trapping is carried out at the user-level, eliminating the need for unsupported hardware or device-level programming. A sending process attaches its status to outgoing messages so local schedulers on remote nodes can make more intelligent scheduling decisions. Once scheduled, processes are guaranteed some minimum period of time to execute. This provides an opportunity to synchronize the parallel job's components across all nodes and achieve good program performance. The results from a performance study reveal that the proposed technique is a promising approach that can reduce response time significantly over uncoordinated scheduling.

  3. Performance and economy of a fault-tolerant multiprocessor

    NASA Technical Reports Server (NTRS)

    Lala, J. H.; Smith, C. J.

    1979-01-01

    The FTMP (Fault-Tolerant Multiprocessor) is one of two central aircraft fault-tolerant architectures now in the prototype phase under NASA sponsorship. The intended application of the computer includes such critical real-time tasks as 'fly-by-wire' active control and completely automatic Category III landings of commercial aircraft. The FTMP architecture is briefly described and it is shown that it is a viable solution to the multi-faceted problems of safety, speed, and cost. Three job dispatch strategies are described, and their results with respect to job-starting delay are presented. The first strategy is a simple First-Come-First-Serve (FCFS) job dispatch executive. The other two schedulers are an adaptive FCFS and an interrupt driven scheduler. Three failure modes are discussed, and the FTMP survival probability in the face of random hard failures is evaluated. It is noted that the hourly cost of operating two FTMPs in a transport aircraft can be as little as one-to-two percent of the total flight-hour cost of the aircraft.

  4. What's in a Number? Estimating numbers of viable Candidatus Liberibacter asiaticus cells in citrus and ACP

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Knowledge of CLas viability is critical for answering questions about how the organism is proliferating within citrus and ACP, what is the response to therapeutic treatments, and for understanding disease development. Because CLas cannot be grown in culture, estimating cell viability has not been po...

  5. Parallel Reduction of Large Radar Interferometry Scenes on a Mid-scale, Symmetric Multiprocessor Mainframe Computer

    NASA Astrophysics Data System (ADS)

    Harcke, L. J.; Zebker, H. A.

    2006-12-01

    We report on experiences in processing repeat-orbit interferometry data sets on a mid-scale multiprocessor mainframe computer. Newer applications of interferometric and polarimetric data processing, such as permanent scatterer deformation monitoring, require the generation of many tens of repeat-pass interferometry data pairs, perhaps 30 to 50, to provide sufficient input to the deformation model. Moving existing radar processing techniques toward massively parallel computation provides a path to coping with such large data sets, which can consist of 30 to 50 gigabytes (GB) of raw data. In June 2006, the Stanford School of Earth Sciences dedicated a new computation center for general research use. Two large machines compose the center: a single-node, symmetric multiprocessor (SMP) machine with 48 processor cores and a single 192~GB memory, and a 64 node distributed cluster containing 128 processor cores with at least 2~GB of memory per node. Distributed processing of the matched filter for synthetic aperture radar image formation requires a high communication-to-computation ratio. Experiments performed over a decade ago on distributed memory supercomputers, and repeated a half-decade ago on commodity workstation clusters, both demonstrated saturation of inter-node communication links. For this reason, we chose to parallelize the interferometric processor on the shared memory computer using the OpenMP programming standard. We find, not unexpectedly, that the input/output stage of processing standard 100-by-100~kilometer ERS-1 scenes quickly dominates the total computation time, and that only modest increases in processing time are achieved after 8 to 16 processor cores are brought to bear on a single data set. The input and output data sit in single, serially accessed disk files, creating a bottleneck for overall throughput. This points to a scheme for efficient partitioning of mid-size (24 to 48~core) machines for reducing large Earth science data sets, where 3 to

  6. Solving Partial Differential Equations in a data-driven multiprocessor environment

    SciTech Connect

    Gaudiot, J.L.; Lin, C.M.; Hosseiniyar, M.

    1988-12-31

    Partial differential equations can be found in a host of engineering and scientific problems. The emergence of new parallel architectures has spurred research in the definition of parallel PDE solvers. Concurrently, highly programmable systems such as data-how architectures have been proposed for the exploitation of large scale parallelism. The implementation of some Partial Differential Equation solvers (such as the Jacobi method) on a tagged token data-flow graph is demonstrated here. Asynchronous methods (chaotic relaxation) are studied and new scheduling approaches (the Token No-Labeling scheme) are introduced in order to support the implementation of the asychronous methods in a data-driven environment. New high-level data-flow language program constructs are introduced in order to handle chaotic operations. Finally, the performance of the program graphs is demonstrated by a deterministic simulation of a message passing data-flow multiprocessor. An analysis of the overhead in the data-flow graphs is undertaken to demonstrate the limits of parallel operations in dataflow PDE program graphs.

  7. Solution Structure of 4'-Phosphopantetheine - GmACP3 from Geobacter Metallireducens: A Specialized Acyl Carrier Protein with Atypical Structural Features and a Putative Role in Lipopolysaccharide Biosyntheses

    SciTech Connect

    Ramelot, Theresa A.; Smola, Matthew J.; Lee, Hsiau-Wei; Ciccosanti, Colleen; Hamilton, Keith; Acton, Thomas; Xiao, Rong; Everett, John K.; Prestegard, James H.; Montelione, Gaetano; Kennedy, Michael A.

    2011-03-08

    GmACP3 from Geobacter metallireducens is a specialized acyl carrier protein (ACP) whose gene, gmet_2339, is located near genes encoding many proteins involved in lipopolysaccharide (LPS) biosynthesis, indicating a likely function for GmACP3 in LPS production. By overexpression in Escherichia coli, about 50% holo-GmACP3 and 50% apo-GmACP3 were obtained. Apo-GmACP3 exhibited slow precipitation and non-monomeric behavior by 15NNMRrelaxation measurements. Addition of 4'-phosphopantetheine (4'-PP) via enzymatic conversion by E. coli holo-ACP synthase resulted in stable >95% holo-GmACP3 that was characterized as monomeric by 15N relaxation measurements and had no indication of conformational exchange. We have determined a high-resolution solution structure of holo-GmACP3 by standard NMR methods, including refinement with two sets of NH residual dipolar couplings, allowing for a detailed structural analysis of the interactions between 4'-PP and GmACP3. Whereas the overall four helix bundle topology is similar to previously solved ACP structures, this structure has unique characteristics, including an ordered 4'-PP conformation that places the thiol at the entrance to a central hydrophobic cavity near a conserved hydrogen-bonded Trp-His pair. These residues are part of a conservedWDSLxH/N motif found in GmACP3 and its orthologs. The helix locations and the large hydrophobic cavity are more similar tomediumand long-chain acyl-ACPs than to other apo- and holo-ACP structures. Taken together, structural characterization along with bioinformatic analysis of nearby genes suggests that GmACP3 is involved in lipid A acylation, possibly by atypical long-chain hydroxy fatty acids, and potentially is involved in synthesis of secondary metabolites.

  8. Optical RAM-enabled cache memory and optical routing for chip multiprocessors: technologies and architectures

    NASA Astrophysics Data System (ADS)

    Pleros, Nikos; Maniotis, Pavlos; Alexoudi, Theonitsa; Fitsios, Dimitris; Vagionas, Christos; Papaioannou, Sotiris; Vyrsokinos, K.; Kanellos, George T.

    2014-03-01

    The processor-memory performance gap, commonly referred to as "Memory Wall" problem, owes to the speed mismatch between processor and electronic RAM clock frequencies, forcing current Chip Multiprocessor (CMP) configurations to consume more than 50% of the chip real-estate for caching purposes. In this article, we present our recent work spanning from Si-based integrated optical RAM cell architectures up to complete optical cache memory architectures for Chip Multiprocessor configurations. Moreover, we discuss on e/o router subsystems with up to Tb/s routing capacity for cache interconnection purposes within CMP configurations, currently pursued within the FP7 PhoxTrot project.

  9. Results of First Outdoor Comparison Between Absolute Cavity Pyrgeometer (ACP) and Infrared Integrating Sphere (IRIS) Radiometer at PMOD (Presentation)

    SciTech Connect

    Reda, I.; Grobner, J.; Wacker, S.; Stoffel, T.

    2013-03-01

    The ACP and IRIS are developed to establish a world reference for calibrating pyrgeometers with traceability to SI units. The two radiometers are unwindowed with negligible spectral dependence, and traceable to SI units through the temperature scale (ITS-90). The first outdoor comparison between the two designs was held from January 28 to February 8, 2013 at the Physikalisch-Metorologisches Observatorium Davos (PMOD). The difference between the irradiance measured by ACP and that of IRIS was within 1 W/m2. A difference of 5 W/m2 was observed between the irradiance measured by ACP&IRIS and that of the interim World Infrared Standard Group (WISG).

  10. Effects of the addition of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) on mechanical properties of luting and lining glass ionomer cement

    NASA Astrophysics Data System (ADS)

    Heravi, Farzin; Bagheri, Hossein; Rangrazi, Abdolrasoul; Mojtaba Zebarjad, Seyed

    2016-07-01

    Recently, the addition of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) into glass ionomer cements (GICs) has attracted interest due to its remineralization of teeth and its antibacterial effects. However, it should be investigated to ensure that the incorporation of CPP-ACP does not have significant adverse effects on its mechanical properties. The purpose of this study was to evaluate the effects of the addition of CPP-ACP on the mechanical properties of luting and lining GIC. The first step was to synthesize the CPP-ACP. Then the CPP-ACP at concentrations of 1%, 1.56% and 2% of CPP-ACP was added into a luting and lining GIC. GIC without CPP-ACP was used as a control group. The results revealed that the incorporation of CPP-ACP up to 1.56%(w/w) increased the flexural strength (29%), diametral tensile strength (36%) and microhardness (18%), followed by a reduction in these mechanical properties at 2%(w/w) CPP-ACP. The wear rate was significantly decreased (23%) in 1.56%(w/w) concentration of CPP-ACP and it was increased in 2%(w/w). Accordingly, the addition of 1.56%(w/w) CPP-ACP into luting and lining GIC had no adverse effect on the mechanical properties of luting and lining GIC and could be used in clinical practice.

  11. Inhibition of a Mycobacterium tuberculosis beta-ketoacyl ACP synthase by isoniazid.

    PubMed

    Mdluli, K; Slayden, R A; Zhu, Y; Ramaswamy, S; Pan, X; Mead, D; Crane, D D; Musser, J M; Barry, C E

    1998-06-01

    Although isoniazid (isonicotinic acid hydrazide, INH) is widely used for the treatment of tuberculosis, its molecular target has remained elusive. In response to INH treatment, saturated hexacosanoic acid (C26:0) accumulated on a 12-kilodalton acyl carrier protein (AcpM) that normally carried mycolic acid precursors as long as C50. A protein species purified from INH-treated Mycobacterium tuberculosis was shown to consist of a covalent complex of INH, AcpM, and a beta-ketoacyl acyl carrier protein synthase, KasA. Amino acid-altering mutations in the KasA protein were identified in INH-resistant patient isolates that lacked other mutations associated with resistance to this drug. PMID:9616124

  12. Histochemical localization and characterization of AKP, ACP, NSE, and POD from cultured Apostichopus japonicus

    NASA Astrophysics Data System (ADS)

    Li, Jiye; Sun, Xiuqin; Zheng, Fengrong; Sun, Hushan

    2009-09-01

    We investigated the distribution of four enzymes involved in the immune response of Apostichopus japonicus. We collected samples of the tentacles, papillate podium, integument, respiratory tree, and digestive tract and stained them for acid phosphatase (ACP), alkaline phosphatase (AKP), non-specific esterase (NSE) and peroxidase (POD) activity. The distribution and content of ACP, AKP, NSE, and POD differed among the tissues. The coelomic epithelium of the tentacle, papillate podium, and integument and the mucous layer of respiratory tree were positive for ACP activity. The coelomic epithelium and cuticular layer of the tentacle, papillate podium, and integument and the mucous layer and tunica externa of the respiratory tree and digestive tract stained positive or weakly positive for AKP activity. Almost all the epithelial tissues stained positive, strongly positive, or very strongly positive for NSE activity. The cuticular layer of the tentacle and integument and the mucous layer, tunica submucosa, and tunica externa of the respiratory tree and digestive tract stained positive for POD activity. We hypothesize that these enzymes play a role in the immune response in A. japonicus.

  13. Acyl-ACP thioesterases from macadamia (Macadamia tetraphylla) nuts: cloning, characterization and their impact on oil composition.

    PubMed

    Moreno-Pérez, Antonio J; Sánchez-García, Alicia; Salas, Joaquín J; Garcés, Rafael; Martínez-Force, Enrique

    2011-01-01

    The mechanisms by which macadamia nuts accumulate the unusual palmitoleic and asclepic acyl moieties, which constitute up to 20% of the fatty acids in some varieties, are still unknown. Acyl-acyl carrier protein (ACP) thioesterases (EC 3.1.2.14) are intraplastidial enzymes that terminate the synthesis of fatty acids in plants and that facilitate the export of the acyl moieties to the endoplasmic reticulum where they can be used in the production of glycerolipids. Here, we have investigated the possible role of acyl-ACP thioesterase activity in the composition of macadamia kernel oil. Accordingly, two acyl-ACP thioesterases were cloned from developing macadamia kernels, one of the FatA type and the other of the FatB type. These enzymes were heterologously expressed in Escherichia coli, and the recombinant thioesterases were purified, characterized kinetically and assayed with a variety of substrates, demonstrating the high specificity of macadamia FatA towards 16:1-ACP. Acyl-ACP thioesterase activity was also characterized in crude extracts from two different varieties of macadamia, Cate and Beaumont, which accumulate different amounts of n-7 fatty acids. The impact of acyl-ACP thioesterase activities on the oil composition of these kernels is discussed in the light of these results. PMID:21071236

  14. Hydrogen-oxygen space shuttle ACPS thruster technology review

    NASA Technical Reports Server (NTRS)

    Gregory, J. W.; Herr, P. N.

    1972-01-01

    The generation of technology for injectors, cooled thrust chambers, valves, and ignition systems is discussed. The thrusters are designed to meet a unique and stringent set of requirements, including: long life for 100 mission reuses, high performance, light weight, ability to provide long duration firings as well as small impulse bits, ability to operate over wide ranges of propellant inlet conditions and to withstand reentry heating. The program has included evaluation of thrusters designed for ambient temperature and cold gaseous propellants at the vehicle interface.

  15. Enzymatic assembly of epothilones: the EpoC subunit and reconstitution of the EpoA-ACP/B/C polyketide and nonribosomal peptide interfaces.

    PubMed

    O'Connor, Sarah E; Chen, Huawei; Walsh, Christopher T

    2002-04-30

    The biosynthesis of epothilones, a family of hybrid polyketide (PK)/nonribosomal peptide (NRP) antitumor agents, provides an ideal system to study a hybrid PK/NRP natural product with significant biomedical value. Here the third enzyme involved in epothilone production, the five domain 195 kDa polyketide synthase (PKS) EpoC protein, has been expressed and purified from Escherichia coli. EpoC was combined with the first two enzymes of the epothilone biosynthesis pathway, the acyl carrier protein (ACP) domain of EpoA and EpoB, to reconstitute the early steps in epothilone biosynthesis. The acyltransferase (AT) domain of EpoC transfers the methylmalonyl moiety from methylmalonyl-CoA to the holo HS-acyl carrier protein (ACP) in an autoacylation reaction. The ketosynthase (KS) domain of EpoC decarboxylates the methylmalonyl-S-EpoC acyl enzyme to generate the carbon nucleophile that reacts with methylthiazolylcarboxyl-S-EpoB. The resulting condensation product can be reduced in the presence of NADPH by the ketoreductase (KR) domain of EpoC and then dehydrated by the dehydratase (DH) domain to produce the methylthiazolylmethylacrylyl-S-EpoC acyl enzyme intermediate that serves as the acyl donor for subsequent elongation of the epothilone chain. The acetyl-CoA donor can be replaced with propionyl-CoA, isobutyryl-CoA, and benzoyl-CoA and the acyl chains accepted by both EpoB and EpoC subunits to produce ethyl-, isopropyl-, and phenylthiazolylmethylacrylyl-S-EpoC acyl enzyme intermediates, suggesting that future combinatorial biosynthetic variations in epothilone assembly may be feasible. These results demonstrate in vitro reconstitution of both the PKS/NRPS interface (EpoA-ACP/B) and the NRPS/PKS interface (EpoB/C) in the assembly line for this antitumor natural product. PMID:11969430

  16. Isolation of Vibrio harveyi acyl carrier protein and the fabG, acpP, and fabF genes involved in fatty acid biosynthesis.

    PubMed Central

    Shen, Z; Byers, D M

    1996-01-01

    We report the isolation of Vibrio harveyi acyl carrier protein (ACP) and cloning of a 3,973-bp region containing the fabG (encoding 3-ketoacyl-ACP reductase, 25.5 kDa), acpP (encoding ACP, 8.7 kDa), fabF (encoding 3-ketoacyl-ACP synthase II, 43.1 kDa), and pabC (encoding aminodeoxychorismate lyase, 29.9 kDa) genes. Predicted amino acid sequences were, respectively, 78, 86, 76, and 35% identical to those of the corresponding Escherichia coli proteins. Five of the 11 sequence differences between V. harveyi and E. coli ACP were nonconservative amino acid differences concentrated in a loop region between helices I and II. PMID:8550484

  17. Development of the ACP safeguards neutron counter for PWR spent fuel rods

    NASA Astrophysics Data System (ADS)

    Lee, Tae-Hoon; Menlove, Howard O.; Lee, Sang-Yoon; Kim, Ho-Dong

    2008-04-01

    An advanced neutron multiplicity counter has been developed for measuring spent fuel in the Advanced spent fuel Conditioning Process (ACP) at the Korea Atomic Energy Research Institute (KAERI). The counter uses passive neutron multiplicity counting to measure the 244Cm content in spent fuel. The input to the ACP process is spent fuel from pressurized water reactors (PWRs), and the high intensity of the gamma-ray exposure from spent fuel requires a careful design of the counter to measure the neutrons without gamma-ray interference. The nuclear safeguards for the ACP facility requires the measurement of the spent fuel input to the process and the Cm/Pu ratio for the plutonium mass accounting. This paper describes the first neutron counter that has been used to measure the neutron multiplicity distribution from spent fuel rods. Using multiple samples of PWR spent fuel rod-cuts, the singles (S), doubles (D), and triples (T) rates of the neutron distribution for the 244Cm nuclide were measured and calibration curves were produced. MCNPX code simulations were also performed to obtain the three counting rates and to compare them with the measurement results. The neutron source term was evaluated by using the ORIGEN-ARP code. The results showed systematic difference of 21-24% in the calibration graphs between the measured and simulation results. A possible source of the difference is that the burnup codes have a 244Cm uncertainty greater than ±15% and it would be systematic for all of the calibration samples. The S/D and D/T ratios are almost constant with an increment of the 244Cm mass, and this indicates that the bias is in the 244Cm neutron source calculation using the ORIGEN-ARP source code. The graphs of S/D and D/T ratios show excellent agreement between measurement and MCNPX simulation results.

  18. Combining CPP-ACP with fluoride: a synergistic remineralization potential of artificially demineralized enamel or not?

    NASA Astrophysics Data System (ADS)

    El-Sayad, I. I.; Sakr, A. K.; Badr, Y. A.

    2008-08-01

    Background and objective: Minimal intervention dentistry (MID) calls for early detection and remineralization of initial demineralization. Laser fluorescence is efficient in detecting changes in mineral tooth content. Recaldent is a product of casein phosphopeptide-amorphous calcium phosphate (CPP- ACP) which delivers calcium and phosphate ions to enamel. A new product which also contains fluoride is launched in United States. The remineralizing potential of CPP- ACP per se, or when combined with 0.22% Fl supplied in an oral care gel on artificially demineralised enamel using laser fluorescence was investigated. Methods: Fifteen sound human molars were selected. Mesial surfaces were tested using He-Cd laser beam at 441.5nm with 18mW power as excitation source on a suitable set-up based on Spex 750 M monochromator provided with PMT for detection of collected auto-fluorescence from sound enamel. Mesial surfaces were subjected to demineralization for ten days. The spectra from demineralized enamel were measured. Teeth were then divided according to the remineralizing regimen into three groups: group I recaldent per se, group II recaldent combined with fluoride gel and group III artificial saliva as a positive control. After following these protocols for three weeks, the spectra from remineralized enamel from the three groups were measured. The spectra of enamel auto-fluorescence were recorded and normalized to peak intensity at about 540 nm to compare between spectra from sound, demineralized and remineralized enamel surfaces. Results: A slight red shift was noticed in spectra from demineralized enamel, while a blue shift may occur in remineralized enamel. Group II showed the highest remineralizing potential. Conclusions: Combining fluoride with CPP-ACP had a synergistic effect on enamel remineralization. In addition, laser auto-fluorescence is an accurate technique for assessment of changes in tooth enamel minerals.

  19. Thiolactomycin-Based Inhibitors of Bacterial β-Ketoacyl-ACP Synthases with in Vivo Activity.

    PubMed

    Bommineni, Gopal R; Kapilashrami, Kanishk; Cummings, Jason E; Lu, Yang; Knudson, Susan E; Gu, Chendi; Walker, Stephen G; Slayden, Richard A; Tonge, Peter J

    2016-06-01

    β-Ketoacyl-ACP synthases (KAS) are key enzymes involved in the type II bacterial fatty acid biosynthesis (FASII) pathway and are putative targets for antibacterial discovery. Several natural product KAS inhibitors have previously been reported, including thiolactomycin (TLM), which is produced by Nocardia spp. Here we describe the synthesis and characterization of optically pure 5R-thiolactomycin (TLM) analogues that show improved whole cell activity against bacterial strains including methicillin-resistant Staphylococcus aureus (MRSA) and priority pathogens such as Francisella tularensis and Burkholderia pseudomallei. In addition, we identify TLM analogues with in vivo efficacy against MRSA and Klebsiella pneumoniae in animal models of infection. PMID:27187871

  20. Experiences with Transitioning Science Data Production from a Symmetric Multiprocessor Platform to a Linux Cluster Environment

    NASA Astrophysics Data System (ADS)

    Walter, R. J.; Protack, S. P.; Harris, C. J.; Caruthers, C.; Kusterer, J. M.

    2008-12-01

    NASA's Atmospheric Science Data Center at the NASA Langley Research Center performs all of the science data processing for the Multi-angle Imaging SpectroRadiometer (MISR) instrument. MISR is one of the five remote sensing instruments flying aboard NASA's Terra spacecraft. From the time of Terra launch in December 1999 until February 2008, all MISR science data processing was performed on a Silicon Graphics, Inc. (SGI) platform. However, dramatic improvements in commodity computing technology coupled with steadily declining project budgets during that period eventually made transitioning MISR processing to a commodity computing environment both feasible and necessary. The Atmospheric Science Data Center has successfully ported the MISR science data processing environment from the SGI platform to a Linux cluster environment. There were a multitude of technical challenges associated with this transition. Even though the core architecture of the production system did not change, the manner in which it interacted with underlying hardware was fundamentally different. In addition, there are more potential throughput bottlenecks in a cluster environment than there are in a symmetric multiprocessor environment like the SGI platform and each of these had to be addressed. Once all the technical issues associated with the transition were resolved, the Atmospheric Science Data Center had a MISR science data processing system with significantly higher throughput than the SGI platform at a fraction of the cost. In addition to the commodity hardware, free and open source software such as S4PM, Sun Grid Engine, PostgreSQL and Ganglia play a significant role in the new system. Details of the technical challenges and resolutions, software systems, performance improvements, and cost savings associated with the transition will be discussed. The Atmospheric Science Data Center in Langley's Science Directorate leads NASA's program for the processing, archival and distribution of Earth

  1. Short-term storage of canine preantral ovarian follicles using a powdered coconut water (ACP)-based medium.

    PubMed

    Lima, G L; Costa, L L M; Cavalcanti, D M L P; Rodrigues, C M F; Freire, F A M; Fontenele-Neto, J D; Silva, A R

    2010-07-01

    The objective was to investigate the use of powdered coconut water (ACP)-based medium for short-term preservation of canine preantral follicles. Pairs of ovaries from mongrel bitches (n=9) were divided into fragments. One ovarian fragment, treated as a fresh control, was immediately fixed for histological analysis, whereas the other six ovarian fragments were stored either in phosphate-buffered saline (PBS; control group) or ACP medium in isothermal Styrofoam boxes containing biological ice packs. The boxes were sealed and opened only after 12, 24, or 36h. After opening each box, the ovarian fragments were submitted to histological analysis. In total, 12,302 preantral follicles were evaluated, with 64.5% primordial, 33.3% primary, and 2.3% secondary follicles. There were multiple oocytes in 1.3% of the follicles analyzed. At 24h, ACP was more efficient in preserving follicular morphology than PBS (P<0.05). Compared with the fresh control group, a significant reduction in the percentage of morphologically normal ovarian follicles was observed for PBS, starting at 24h; however, the decline started only at 36h for the ACP medium. During the experiment, the temperature inside the isothermal boxes increased from 3 to 9 degrees C (P<0.05), despite a constant room temperature. In conclusion, powdered coconut water (ACP) was an appropriate medium for short-term storage of canine preantral ovarian follicles. PMID:20207405

  2. Acyl-ACP thioesterases from Camelina sativa: cloning, enzymatic characterization and implication in seed oil fatty acid composition.

    PubMed

    Rodríguez-Rodríguez, Manuel Fernando; Salas, Joaquín J; Garcés, Rafael; Martínez-Force, Enrique

    2014-11-01

    Acyl-acyl carrier protein (ACP) thioesterases are intraplastidial enzymes that terminate de novo fatty acid biosynthesis in the plastids of higher plants by hydrolyzing the thioester bond between ACP and the fatty acid synthesized. Free fatty acids are then esterified with coenzyme A prior to being incorporated into the glycerolipids synthesized through the eukaryotic pathway. Acyl-ACP thioesterases belong to the TE14 family of thioester-active enzymes and can be classified as FatAs and FatBs, which differ in their amino acid sequence and substrate specificity. Here, the FatA and FatB thioesterases from Camelina sativa seeds, a crop of interest in plant biotechnology, were cloned, sequenced and characterized. The mature proteins encoded by these genes were characterized biochemically after they were heterologously expressed in Escherichia coli and purified. C. sativa contained three different alleles of both the FatA and FatB genes. These genes were expressed most strongly in expanding tissues in which lipids are very actively synthesized, such as developing seed endosperm. The CsFatA enzyme displayed high catalytic efficiency on oleoyl-ACP and CsFatB acted efficiently on palmitoyl-ACP. The contribution of these two enzymes to the synthesis of C. sativa oil was discussed in the light of these results. PMID:25212866

  3. Fault detection, isolation and reconfiguration in FTMP Methods and experimental results. [fault tolerant multiprocessor

    NASA Technical Reports Server (NTRS)

    Lala, J. H.

    1983-01-01

    The Fault-Tolerant Multiprocessor (FTMP) is a highly reliable computer designed to meet a goal of 10 to the -10th failures per hour and built with the objective of flying an active-control transport aircraft. Fault detection, identification, and recovery software is described, and experimental results obtained by injecting faults in the pin level in the FTMP are presented. Over 21,000 faults were injected in the CPU, memory, bus interface circuits, and error detection, masking, and error reporting circuits of one LRU of the multiprocessor. Detection, isolation, and reconfiguration times were recorded for each fault, and the results were found to agree well with earlier assumptions made in reliability modeling.

  4. Satisfiability Test with Synchronous Simulated Annealing on the Fujitsu AP1000 Massively-Parallel Multiprocessor

    NASA Technical Reports Server (NTRS)

    Sohn, Andrew; Biswas, Rupak

    1996-01-01

    Solving the hard Satisfiability Problem is time consuming even for modest-sized problem instances. Solving the Random L-SAT Problem is especially difficult due to the ratio of clauses to variables. This report presents a parallel synchronous simulated annealing method for solving the Random L-SAT Problem on a large-scale distributed-memory multiprocessor. In particular, we use a parallel synchronous simulated annealing procedure, called Generalized Speculative Computation, which guarantees the same decision sequence as sequential simulated annealing. To demonstrate the performance of the parallel method, we have selected problem instances varying in size from 100-variables/425-clauses to 5000-variables/21,250-clauses. Experimental results on the AP1000 multiprocessor indicate that our approach can satisfy 99.9 percent of the clauses while giving almost a 70-fold speedup on 500 processors.

  5. Method for wiring allocation and switch configuration in a multiprocessor environment

    DOEpatents

    Aridor, Yariv; Domany, Tamar; Frachtenberg, Eitan; Gal, Yoav; Shmueli, Edi; Stockmeyer, legal representative, Robert E.; Stockmeyer, Larry Joseph

    2008-07-15

    A method for wiring allocation and switch configuration in a multiprocessor computer, the method including employing depth-first tree traversal to determine a plurality of paths among a plurality of processing elements allocated to a job along a plurality of switches and wires in a plurality of D-lines, and selecting one of the paths in accordance with at least one selection criterion.

  6. The Galley Parallel File System

    NASA Technical Reports Server (NTRS)

    Nieuwejaar, Nils; Kotz, David

    1996-01-01

    Most current multiprocessor file systems are designed to use multiple disks in parallel, using the high aggregate bandwidth to meet the growing I/0 requirements of parallel scientific applications. Many multiprocessor file systems provide applications with a conventional Unix-like interface, allowing the application to access multiple disks transparently. This interface conceals the parallelism within the file system, increasing the ease of programmability, but making it difficult or impossible for sophisticated programmers and libraries to use knowledge about their I/O needs to exploit that parallelism. In addition to providing an insufficient interface, most current multiprocessor file systems are optimized for a different workload than they are being asked to support. We introduce Galley, a new parallel file system that is intended to efficiently support realistic scientific multiprocessor workloads. We discuss Galley's file structure and application interface, as well as the performance advantages offered by that interface.

  7. Fast, contention-free combining tree barriers for shared-memory multiprocessors

    SciTech Connect

    Scott, M.L. ); Mellor-Crummey, J.M. )

    1994-08-01

    In a previous article, Gupta and Hill introduced an adaptive combining tree algorithm for busy-wait barrier synchronization on shared-memory multiprocessors. The intent of the algorithm was to achieve a barrier in logarithmic time when processes arrive simultaneously, and in constant time after the last arrival when arrival times are skewed. A fuzzy version of the algorithm allows a process to perform useful work between the point at which it notifies other processes of its arrival and the point at which it waits for all other processes to arrive. Unfortunately, adaptive combining tree barriers as originally devised perform a large amount of work at each node of the tree, including the acquisition and release of locks. They also perform an unbounded number of accesses to nonlocal locations, inducing large amounts of memory and interconnect contention. We present new adaptive combining tree barriers that eliminate these problems. We compare the performance of the new algorithms to that of other fast barriers on a 64-node BBN Butterfly 1 multiprocessor, a 35-node BBN TC2000, and a 126-node KSR 1. The results reveal scenarios in which our algorithms outperform all known alternatives, and suggest that both adaptation and the combination of fuzziness with tree-style synchronization will be of increasing importance on future generations of shared-memory multiprocessors.

  8. A [32P]-NAD+-based method to identify and quantitate long residence time enoyl-ACP reductase inhibitors

    PubMed Central

    Yu, Weixuan; Neckles, Carla; Chang, Andrew; Bommineni, Gopal Reddy; Spagnuolo, Lauren; Zhang, Zhuo; Liu, Nina; Lai, Christina; Truglio, James; Tonge, Peter J.

    2015-01-01

    The classical methods for quantifying drug-target residence time (tR) use loss or regain of enzyme activity in progress curve kinetic assays. However, such methods become imprecise at very long residence times, mitigating the use of alternative strategies. Using the NAD(P)H-dependent FabI enoyl-ACP reductase as a model system, we developed a Penefsky column-based method for direct measurement of tR, where the off-rate of the drug was determined with radiolabeled [adenylate-32P] NAD(P+) cofactor. Twenty-three FabI inhibitors were analyzed and a mathematical model was used to estimate limits to the tR values of each inhibitor based on percent drug-target complex recovery following gel filtration. In general, this method showed good agreement with the classical steady state kinetic methods for compounds with tR values of 10-100 min. In addition, we were able to identify seven long tR inhibitors (100-1500 min) and to accurately determine their tR values. The method was then used to measure tR as a function of temperature, an analysis not previously possible using the standard kinetic approach due to decreased NAD(P)H stability at elevated temperatures. In general, a 4-fold difference in tR was observed when the temperature was increased from 25 °C to 37 °C . PMID:25684450

  9. Chaplain Documentation and the Electronic Medical Record: A Survey of ACPE Residency Programs.

    PubMed

    Tartaglia, Alexander; Dodd-McCue, Diane; Ford, Timothy; Demm, Charles; Hassell, Alma

    2016-01-01

    This study explores the extent to which chaplaincy departments at ACPE-accredited residency programs make use of the electronic medical record (EMR) for documentation and training. Survey data solicited from 219 programs with a 45% response rate and interview findings from 11 centers demonstrate a high level of usage of the EMR as well as an expectation that CPE residents document each patient/family encounter. Centers provided considerable initial training, but less ongoing monitoring of chaplain documentation. Centers used multiple sources to develop documentation tools for the EMR. One center was verified as having created the spiritual assessment component of the documentation tool from a peer reviewed published model. Interviews found intermittent use of the student chart notes for educational purposes. One center verified a structured manner of monitoring chart notes as a performance improvement activity. Findings suggested potential for the development of a standard documentation tool for chaplain charting and training. PMID:26168408

  10. A Project Management Approach to an ACPE Accreditation Self-study

    PubMed Central

    Iwanowicz, Susan L.; Bailie, George R.; Clarke, David W.; McGraw, Patrick S.

    2007-01-01

    In preparation for an on-site evaluation and accreditation by the American Council on Pharmaceutical Education (ACPE), the Albany College of Pharmacy employed project management techniques to complete a comprehensive self-study. A project lifecycle approach, including planning, production, and turnover phases, was used by the project's Self-Study Steering Committee. This approach, with minimal disruption to college operations, resulted in the completion of the self-study process on schedule. Throughout the project, the Steering Committee maintained a log of functions that either were executed successfully or in hindsight, could have been improved. To assess the effectiveness of the project management approach to the the self-study process, feedback was obtained from the College community through a poststudy survey. This feedback, coupled with the Steering Committee's data on possible improvements, form the basis for the lessons learned during this self-study process. PMID:17533432

  11. Rhamnolipid and poly (hydrozyalkanoate) biosynthesis in 3-hydrozyacyl-ACP:COA transacylase (phaG) - knockouts of pseudomonas chloroaphis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The 3-hydroxyacyl-ACP:CoA transacylase gene (phaG(Pc30761)) of P. chlororaphis NRRL B-30761 was cloned and analyzed. The nucleotide and translated amino-acid sequences of phaG(Pc30761) had 99% identities (at 100% query coverage) with the phaG gene of P. fluorescens O6. Two phaG-knockout strains of...

  12. Design and Synthesis of 2-Pyridones as Novel Inhibitors of the Bacillus Anthracis Enoyl–ACP Reductase

    PubMed Central

    Tipparaju, Suresh K.; Joyasawal, Sipak; Forrester, Sara; Mulhearn, Debbie C.; Pegan, Scott; Johnson, Michael E.; Mesecar, Andrew D.; Kozikowski, Alan P.

    2008-01-01

    Enoyl-ACP reductase (ENR), the product of the FabI gene, from Bacillus anthracis (BaENR) is responsible for catalyzing the final step of bacterial fatty acid biosynthesis. A number of novel 2-pyridone derivatives were synthesized and shown to be potent inhibitors of BaENR. PMID:18499454

  13. Nonpreemptive run-time scheduling issues on a multitasked, multiprogrammed multiprocessor with dependencies, bidimensional tasks, folding and dynamic graphs

    SciTech Connect

    Miller, Allan Ray

    1987-05-01

    Increases in high speed hardware have mandated studies in software techniques to exploit the parallel capabilities. This thesis examines the effects a run-time scheduler has on a multiprocessor. The model consists of directed, acyclic graphs, generated from serial FORTRAN benchmark programs by the parallel compiler Parafrase. A multitasked, multiprogrammed environment is created. Dependencies are generated by the compiler. Tasks are bidimensional, i.e., they may specify both time and processor requests. Processor requests may be folded into execution time by the scheduler. The graphs may arrive at arbitrary time intervals. The general case is NP-hard, thus, a variety of heuristics are examined by a simulator. Multiprogramming demonstrates a greater need for a run-time scheduler than does monoprogramming for a variety of reasons, e.g., greater stress on the processors, a larger number of independent control paths, more variety in the task parameters, etc. The dynamic critical path series of algorithms perform well. Dynamic critical volume did not add much. Unfortunately, dynamic critical path maximizes turnaround time as well as throughput. Two schedulers are presented which balance throughput and turnaround time. The first requires classification of jobs by type; the second requires selection of a ratio value which is dependent upon system parameters. 45 refs., 19 figs., 20 tabs.

  14. Microleakage of Three Types of Glass Ionomer Cement Restorations: Effect of CPP-ACP Paste Tooth Pretreatment

    PubMed Central

    Doozandeh, Maryam; Shafiei, Fereshteh; Alavi, Mostafa

    2015-01-01

    Statement of the Problem Casein phosphopeptide–amorphous calcium phosphate (CPP-ACP) increases the mineral content of tooth structure. This may enhance the chemical bonding of glass ionomer cements (GIC) and marginal sealing of their restorations. Purpose The aim of this study was to evaluate the effect of CPP-ACP paste pretreatment on the microleakage of three types of GIC. Materials and Method In this study, 72 Class V cavities were prepared on the buccal and lingual surfaces of molars with occlusal margins in enamel and gingival margins in root. The cavities were divided into 6 groups. Cavities in group 1 and 2 were restored with Fuji II, group 3 and 4 with Fuji II LC, and group 5 and 6 with Ketac N100 with respect to the manufacturers’ instructions. In groups 2, 4 and 6, CPP-ACP containing paste (MI paste) was placed into the cavities for 3 minutes before being filled with GIC. The teeth were thermocycled, stained with dye, sectioned, and scored for microleakage under stereomicroscope. Kruskall-Wallis and Chi-Square tests were used to analyze the data. Result There were no statistically significant differences between the control and the CPP-ACP pretreatment groups in enamel and dentin margins. In pairwise comparisons, there were no significant differences between the control and the experimental groups in enamel margin, and in dentin margins of G1 and 2, G5 and 6; however, a significant differences was detected in dentin margins between G3 and 4 (p= 0.041). Conclusion CPP-ACP paste pretreatment did not affect the microleakage of Fuji II and Ketac N100 in enamel or dentin, but decreased the microleakage in dentine margins of Fuji II LC when cavity conditioner was applied before surface treatment. PMID:26331147

  15. The Acid Phosphatase-Encoding Gene GmACP1 Contributes to Soybean Tolerance to Low-Phosphorus Stress

    PubMed Central

    Hao, Derong; Wang, Hui; Kan, Guizhen; Jin, Hangxia; Yu, Deyue

    2014-01-01

    Phosphorus (P) is essential for all living cells and organisms, and low-P stress is a major factor constraining plant growth and yield worldwide. In plants, P efficiency is a complex quantitative trait involving multiple genes, and the mechanisms underlying P efficiency are largely unknown. Combining linkage analysis, genome-wide and candidate-gene association analyses, and plant transformation, we identified a soybean gene related to P efficiency, determined its favorable haplotypes and developed valuable functional markers. First, six major genomic regions associated with P efficiency were detected by performing genome-wide associations (GWAs) in various environments. A highly significant region located on chromosome 8, qPE8, was identified by both GWAs and linkage mapping and explained 41% of the phenotypic variation. Then, a regional mapping study was performed with 40 surrounding markers in 192 diverse soybean accessions. A strongly associated haplotype (P = 10−7) consisting of the markers Sat_233 and BARC-039899-07603 was identified, and qPE8 was located in a region of approximately 250 kb, which contained a candidate gene GmACP1 that encoded an acid phosphatase. GmACP1 overexpression in soybean hairy roots increased P efficiency by 11–20% relative to the control. A candidate-gene association analysis indicated that six natural GmACP1 polymorphisms explained 33% of the phenotypic variation. The favorable alleles and haplotypes of GmACP1 associated with increased transcript expression correlated with higher enzyme activity. The discovery of the optimal haplotype of GmACP1 will now enable the accurate selection of soybeans with higher P efficiencies and improve our understanding of the molecular mechanisms underlying P efficiency in plants. PMID:24391523

  16. Benchmarking Ada tasking on tightly coupled multiprocessor architectures

    NASA Technical Reports Server (NTRS)

    Collard, Philippe; Goforth, Andre; Marquardt, Matthew

    1989-01-01

    The development of benchmarks and performance measures for parallel Ada tasking is reported with emphasis on the macroscopic behavior of the benchmark across a set of load parameters. The application chosen for the study was the NASREM model for telerobot control, relevant to many NASA missions. The results of the study demonstrate the potential of parallel Ada in accomplishing the task of developing a control system for a system such as the Flight Telerobotic Servicer using the NASREM framework.

  17. Biomimetic remineralization of demineralized dentine using scaffold of CMC/ACP nanocomplexes in an in vitro tooth model of deep caries.

    PubMed

    Chen, Zhen; Cao, Shansong; Wang, Haorong; Li, Yanqiu; Kishen, Anil; Deng, Xuliang; Yang, Xiaoping; Wang, Yinghui; Cong, Changhong; Wang, Huajun; Zhang, Xu

    2015-01-01

    Currently, it is still a tough task for dentists to remineralize dentine in deep caries. The aim of this study was to remineralize demineralized dentine in a tooth model of deep caries using nanocomplexes of carboxymethyl chitosan/amorphous calcium phosphate (CMC/ACP) based on mimicking the stabilizing effect of dentine matrix protein 1 (DMP1) on ACP in the biomineralization of dentine. The experimental results indicate that CMC can stabilize ACP to form nanocomplexes of CMC/ACP, which is able to be processed into scaffolds by lyophilization. In the single-layer collagen model, ACP nanoparticles are released from scaffolds of CMC/ACP nanocomplexes dissolved and then infiltrate into collagen fibrils via the gap zones (40 nm) to accomplish intrafibrillar mineralization of collagen. With this method, the completely demineralized dentine was partially remineralized in the tooth mode. This is a bottom-up remineralizing strategy based on non-classical crystallization theory. Since nanocomplexes of CMC/ACP show a promising effect of remineralization on demineralized dentine via biomimetic strategy, thereby preserving dentinal tissue to the maximum extent possible, it would be a potential indirect pulp capping (IPC) material for the management of deep caries during vital pulp therapy based on the concept of minimally invasive dentistry (MID). PMID:25587986

  18. Biomimetic Remineralization of Demineralized Dentine Using Scaffold of CMC/ACP Nanocomplexes in an In Vitro Tooth Model of Deep Caries

    PubMed Central

    Chen, Zhen; Cao, Shansong; Wang, Haorong; Li, Yanqiu; Kishen, Anil; Deng, Xuliang; Yang, Xiaoping; Wang, Yinghui; Cong, Changhong; Wang, Huajun; Zhang, Xu

    2015-01-01

    Currently, it is still a tough task for dentists to remineralize dentine in deep caries. The aim of this study was to remineralize demineralized dentine in a tooth model of deep caries using nanocomplexes of carboxymethyl chitosan/amorphous calcium phosphate (CMC/ACP) based on mimicking the stabilizing effect of dentine matrix protein 1 (DMP1) on ACP in the biomineralization of dentine. The experimental results indicate that CMC can stabilize ACP to form nanocomplexes of CMC/ACP, which is able to be processed into scaffolds by lyophilization. In the single-layer collagen model, ACP nanoparticles are released from scaffolds of CMC/ACP nanocomplexes dissolved and then infiltrate into collagen fibrils via the gap zones (40 nm) to accomplish intrafibrillar mineralization of collagen. With this method, the completely demineralized dentine was partially remineralized in the tooth mode. This is a bottom-up remineralizing strategy based on non-classical crystallization theory. Since nanocomplexes of CMC/ACP show a promising effect of remineralization on demineralized dentine via biomimetic strategy, thereby preserving dentinal tissue to the maximum extent possible, it would be a potential indirect pulp capping (IPC) material for the management of deep caries during vital pulp therapy based on the concept of minimally invasive dentistry (MID). PMID:25587986

  19. Overexpression of the olive acyl carrier protein gene (OeACP1) produces alterations in fatty acid composition of tobacco leaves.

    PubMed

    De Marchis, Francesca; Valeri, Maria Cristina; Pompa, Andrea; Bouveret, Emmanuelle; Alagna, Fiammetta; Grisan, Simone; Stanzione, Vitale; Mariotti, Roberto; Cultrera, Nicolò; Baldoni, Luciana; Bellucci, Michele

    2016-02-01

    Taking into account that fatty acid (FA) biosynthesis plays a crucial role in lipid accumulation in olive (Olea europaea L.) mesocarp, we investigated the effect of olive acyl carrier protein (ACP) on FA composition by overexpressing an olive ACP cDNA in tobacco plants. The OeACP1.1A cDNA was inserted in the nucleus or in the chloroplast DNA of different tobacco plants, resulting in extensive transcription of the transgenes. The transplastomic plants accumulated lower olive ACP levels in comparison to nuclear-transformed plants. Moreover, the phenotype of the former plants was characterized by pale green/white cotyledons with abnormal chloroplasts, delayed germination and reduced growth. We suggest that the transplastomic phenotype was likely caused by inefficient olive ACP mRNA translation in chloroplast stroma. Conversely, total lipids from leaves of nuclear transformants expressing high olive ACP levels showed a significant increase in oleic acid (18:1) and linolenic acid (18:3), and a concomitant significant reduction of hexadecadienoic acid (16:2) and hexadecatrienoic acid (16:3). This implies that in leaves of tobacco transformants, as likely in the mesocarp of olive fruit, olive ACP not only plays a general role in FA synthesis, but seems to be specifically involved in chain length regulation forwarding the elongation to C18 FAs and the subsequent desaturation to 18:1 and 18:3. PMID:26560313

  20. EMMA2, a high-performance hierarchical multiprocessor

    SciTech Connect

    Civera, P.; Piccinini, G.; Zamboni, M.

    1989-02-01

    The search for new products in the field of advanced automation pushes application of recent technology research. Most often, the unavailability of suitable computational structures stunts the possibility of turning research results into industrial applications. This fact is particularly true in advanced automation systems, those systems that emulate functions usually carried out by humans. Consider for example speech recognition, artificial vision, and pattern recognition applications. The high throughput required by these types of systems has often led to the design of dedicated architectures with low flexibility and narrow applicability. At Elsag we wanted to make a more-general approach that aimed at a wider diffusion of such systems for the industrial processes and services areas of advanced automation. A further constraint we considered is that our applications are often characterized by their needs for strong customization. This requirement entails a computational structure capable of a wide range of performances and modular in nature. The answer to the problems above, from our experience, lies in parallel processing, possibly supported by computer structures and development environments that match application requirements as closely as possible. The challenging problem, in an industrial context, is to develop a computer architecture capable of delivering enough computational power, with a high degree of modularity, provided at a reasonable cost and with an effective programming and development environment.

  1. Solution Structure of 4′-Phosphopantetheine - GmACP3 from Geobacter metallireducens: A Specialized Acyl Carrier Protein with Atypical Structural Features and a Putative Role in Lipopolysaccharide Biosynthesis†

    PubMed Central

    Ramelot, Theresa A.; Smola, Matthew J.; Lee, Hsiau-Wei; Ciccosanti, Colleen; Hamilton, Keith; Acton, Thomas B.; Xiao, Rong; Everett, John K.; Prestegard, James H.; Montelione, Gaetano T.; Kennedy, Michael A.

    2011-01-01

    GmACP3 from Geobacter metallireducens is a specialized acyl carrier protein (ACP) whose gene, gmet_2339, is located near genes encoding many proteins involved in lipopolysaccharide (LPS) biosynthesis, indicating a likely function for GmACP3 in LPS production. By overexpression in Escherichia coli, about 50% holo-GmACP3 and 50% apo-GmACP3 were obtained. Apo-GmACP3 exhibited slow precipitation and non-monomeric behavior by 15N NMR relaxation measurements. Addition of 4′-phosphopantetheine (4′-PP) via enzymatic conversion by E. coli holo-ACP synthase, resulted in stable >95% holo-GmACP3 that was characterized as monomeric by 15N relaxation measurements and had no indication of conformational exchange. We have determined a high-resolution solution structure of holo-GmACP3 by standard NMR methods, including refinement with two sets of NH residual dipolar couplings, allowing for a detailed structural analysis of the interactions between 4′-PP and GmACP3. Whereas the overall four helix bundle topology is similar to previously solved ACP structures, this structure has unique characteristics, including an ordered 4′-PP conformation that places the thiol at the entrance to a central hydrophobic cavity near a conserved hydrogen-bonded Trp-His pair. These residues are part of a conserved WDSLxH/N motif found in GmACP3 and it’s orthologs. The helix locations and the large hydrophobic cavity are more similar to medium- and long-chain acyl-ACPs than to other apo- and holo-ACP structures. Taken together, structural characterization along with bioinformatic analysis of nearby genes suggest that GmACP3 is involved in lipid A acylation, possibly by atypical long-chain hydroxy fatty acids, and potentially involved in synthesis of secondary metabolites. PMID:21235239

  2. Pipeline multiprocessor architecture for high speed cell image analysis

    SciTech Connect

    Castleman, K.R.; Price, K.H.; Eskenazi, R.; Ovadya, M.M.; Navon, M.A.

    1983-10-01

    A pipeline multiple-microprocessor architecture for high-speed digital image processing is being developed. The goal is a compact, fast, and low-cost pap smear analyzer for cervical cancer detection. Each processor communicates with one or two upstream processors and from one to 13 downstream processors via shared memory. Each of the identical pipeline modules (PC boards) has a Motorla MC6809 microprocessor with a 2 megabyte memory management unit, two 64kbyte dual-port image memories (shared with upstream processors) and one 64kbyte dual-port program memory (shared with a host computer). Intermodule communication is achieved by ribbon cables connected to connectors at the top of the boards. This allows considerable flexibility in configuring the system. This architecture should facilitate efficient (fast, low-cost) implementations of complex single-purpose image processing systems.

  3. Development of FPGA based NURBS interpolator and motion controller with multiprocessor technique

    NASA Astrophysics Data System (ADS)

    Zhao, Huan; Zhu, Limin; Xiong, Zhenhua; Ding, Han

    2013-09-01

    The high-speed computational performance is gained at the cost of huge hardware resource, which restricts the application of high-accuracy algorithms because of the limited hardware cost in practical use. To solve the problem, a novel method for designing the field programmable gate array(FPGA)-based non-uniform rational B-spline(NURBS) interpolator and motion controller, which adopts the embedded multiprocessor technique, is proposed in this study. The hardware and software design for the multiprocessor, one of which is for NURBS interpolation and the other for position servo control, is presented. Performance analysis and experiments on an X-Y table are carried out, hardware cost as well as consuming time for interpolation and motion control is compared with the existing methods. The experimental and comparing results indicate that, compared with the existing methods, the proposed method can reduce the hardware cost by 97.5% using higher-accuracy interpolation algorithm within the period of 0.5 ms. A method which ensures the real-time performance and interpolation accuracy, and reduces the hardware cost significantly is proposed, and it’s practical in the use of industrial application.

  4. Evaluation of the Cedar memory system: Configuration of 16 by 16

    NASA Technical Reports Server (NTRS)

    Gallivan, K.; Jalby, W.; Wijshoff, H.

    1991-01-01

    Some basic results on the performance of the Cedar multiprocessor system are presented. Empirical results on the 16 processor 16 memory bank system configuration, which show the behavior of the Cedar system under different modes of operation are presented.

  5. Paging tradeoffs in distributed-shared-memory multiprocessors

    SciTech Connect

    Burger, D.C.; Hyder, R.S.; Miller, B.P.; Wood, D.A.

    1994-12-31

    Massively parallel processors have begun using commodity operating systems that support demand-paged virtual memory. To evaluate the utility of virtual memory, the authors measured the behavior of seven shared memory parallel application programs on a simulated distributed-shared-memory machine. The results (1) confirm the importance of gang CPU scheduling, (2) show that a page-faulting processor should spin rather than invoke a parallel context switch, (3) show that the parallel programs frequently touch most of their data, and (4) indicate that memory, not just CPUs, must be ``gang scheduled``. Overall, the experiments demonstrate that demand paging has limited value on current parallel machines because of the applications` synchronization and memory reference patterns and the machines` high page-fault and parallel-context-switch overheads.

  6. Results of Second Outdoor Comparison Between Absolute Cavity Pyrgeometer (ACP) and Infrared Integrating Sphere (IRIS) Radiometer at PMOD (Presentation)

    SciTech Connect

    Reda, I.; Grobner, J.; Wacker, S.

    2014-01-01

    The Absolute Cavity Pyrgeometer (ACP) and InfraRed Integrating Sphere radiometer (IRIS) are developed to establish a world reference for calibrating pyrgeometers with traceability to SI units. The two radiometers are un-windowed with negligible spectral dependence, and traceable to SI units through the temperature scale (ITS-90). The second outdoor comparison between the two designs was held from September 30 to October 11, 2013 at the Physikalisch-Metorologisches Observatorium Davos (PMOD). The difference between the irradiance measured by ACP and that of the IRIS was within 1 W/m2 (3 IRISs: PMOD + Australia + Germany). From the first and second comparisons, a difference of 4-6 W/m2 was observed between the irradiance measured by ACP&IRIS and that of the interim World Infrared Standard Group (WISG). This presentation includes results from the first and second comparison in an effort to establish the world reference for pyrgeometer calibrations, a key deliverable for the World Meteorological Organization (WMO), and the DOE-ASR.

  7. Analysis of Photonic Networks for a Chip Multiprocessor Using Scientific Applications

    SciTech Connect

    Kamil, Shoaib A; Hendry, Gilbert; Biberman, Aleksandr; Chan, Johnnie; Lee, Benjamin G.; Mohiyuddin, Marghoob; Jain, Ankit; Bergman, Keren; Carloni, Luca; Kubiatowicz, John; Oliker, Leonid; Shalf, John

    2009-01-31

    As multiprocessors scale to unprecedented numbers of cores in order to sustain performance growth, it is vital that these gains are not nullified by high energy consumption from inter-core communication. With recent advances in 3D Integration CMOS technology, the possibility for realizing hybrid photonic-electronic networks-on-chip warrants investigating real application traces on functionally comparable photonic and electronic network designs. We present a comparative analysis using both synthetic benchmarks as well as real applications, run through detailed cycle accurate models implemented under the OMNeT++ discrete event simulation environment. Results show that when utilizing standard process-to-processor mapping methods, this hybrid network can achieve 75X improvement in energy efficiency for synthetic benchmarks and up to 37X improvement for real scientific applications, defined as network performance per energy spent, over an electronic mesh for large messages across a variety of communication patterns.

  8. Compiled execution of the reduce-or process model on multiprocessors

    SciTech Connect

    Ramkumar, B.; Kale, L.V. )

    1989-01-01

    In this paper, the authors describe the abstract machine developed for the reduce - or process model (ROPM) and its implementation on a variety of multiprocessors. In keeping with the objective behind the ROPM, the abstract machine is suitable for execution on both shared and nonshared memory machines. It uses structure sharing unlike most of the abstract machines based on the WAM. This is due to significant benefits in a nonshared memory context. It has currently been implemented on the Encore Multimax, the Sequent Symmetry, the Alliant, and the InteliPSC/2. The authors provide preliminary performance data of our implementations on these machines in this paper. The benchmarks chosen illustrate the range of programs which ROPM can parallelize - and, or, as well as and/or parallel programs are effectively parallelized and speeded up.

  9. Identification and expression of a stearoyl-ACP desaturase gene responsible for oleic acid accumulation in Xanthoceras sorbifolia seeds.

    PubMed

    Zhao, Na; Zhang, Yuan; Li, Qiuqi; Li, Rufang; Xia, Xinli; Qin, Xiaowei; Guo, Huihong

    2015-02-01

    Xanthoceras sorbifolia Bunge is an oilseed tree that grows well on barren lands in dry climate. Its seeds contain a large amount of oil rich in oleic acid (18:1(Δ9)) and linoleic acid (18:2(Δ9, 12)). However, the molecular regulation of oil biosynthesis in X. sorbifolia seeds is poorly understood. Stearoyl-ACP desaturase (SAD, EC 1.14.99.6) is a plastid-localized soluble desaturase that catalyzes the conversion of stearic acid (18:0) to oleic acid, which plays a key role in determining the ratio of saturated to unsaturated fatty acids. In this study, a full-length cDNA of XsSAD was isolated from developing X. sorbifolia embryos. The XsSAD open reading frame had 1194-bp, encoding a polypeptide of 397 amino acids. XsSAD expression in Escherichia coli cells resulted in increased 18:1(Δ9) level, confirming the biological activity of the enzyme encoded by XsSAD. XsSAD expression in Arabidopsis ssi2 mutants partially restored the morphological phenotype and effectively increased the 18:1(Δ9) level. The levels of other unsaturated fatty acids synthesized with 18:1(Δ9) as the substrate also increased to some degree. XsSAD in X. sorbifolia had a much higher expression in embryos than in leaves and petals. XsSAD expression also correlated well with the oleic acid, unsaturated fatty acid, and total fatty acid levels in developing embryos. These data suggested that XsSAD determined the synthesis of oleic acid and contributed to the accumulation of unsaturated fatty acid and total oil in X. sorbifolia seeds. A preliminary tobacco rattle virus-based virus-induced gene silencing system established in X. sorbifolia can also be helpful for further analyzing the functions of XsSAD and other oil synthesis-related genes in woody plants. PMID:25528221

  10. Can laboratory tholins mimic the chemistry producing Titan's aerosols? A review in light of ACP experimental results

    NASA Astrophysics Data System (ADS)

    Coll, P.; Navarro-González, R.; Szopa, C.; Poch, O.; Ramírez, S. I.; Coscia, D.; Raulin, F.; Cabane, M.; Buch, A.; Israël, G.

    2013-03-01

    The first results obtained by the ACP experiment onboard Huygens probe revealed that the main products obtained after thermolysis of Titan's collected aerosols, were ammonia (NH3) and hydrogen cyanide (HCN). Titan's aerosols, and their laboratory analogues named tholins, have been the subject of experimental or theoretical studies during the last four decades. These studies have been mainly devoted to understanding their origin and formation mechanisms, their physical, chemical and optical properties, and their role in the radiative equilibrium of the satellite. Before the arrival of the Cassini-Huygens mission, the dense layer of aerosols hid many aspects of the satellite's surface and precious information about its composition. If Titan's aerosols have been in the eye and mind of planetary scientists during such a long time, it is not surprising that a literature survey displays a good quantity of papers on aerosol analogues. With aerosol analogues we mean any material produced in a terrestrial laboratory under conditions that try to represent those of Titan's atmosphere. We present here a study aimed to understand the particularities of aerosol analogues synthesized in different laboratories around the world in order to determine some of their most representative chemical fingerprints and in some cases, to perform a direct comparison of the volatiles produced after a thermal treatment done in conditions similar to the ones used by the ACP experiment. From the information collected, we propose a broad classification of aerosol analogues highlighting the materials that can be more representative of Titan's aerosols in terms of their content of organic volatiles. We identify the laboratory analogs that best suit the ACP results; such identification is of prime importance to correctly predict the optical properties of Titan's aerosol and to accurately estimate their contribution in radiative equilibrium models and/or to assess their role in chemical reactions of

  11. Production of long chain alcohols and alkanes upon coexpression of an acyl-ACP reductase and aldehyde-deformylating oxgenase with a bacterial type-I fatty acid synthase in E. coli

    DOE PAGESBeta

    Coursolle, Dan; Shanklin, John; Lian, Jiazhang; Zhao, Huimin

    2015-06-23

    Microbial long chain alcohols and alkanes are renewable biofuels that could one day replace petroleum-derived fuels. Here we report a novel pathway for high efficiency production of these products in Escherichia coli strain BL21(DE3). We first identified the acyl-ACP reductase/aldehyde deformylase combinations with the highest activity in this strain. Next, we used catalase coexpression to remove toxic byproducts and increase the overall titer. Finally, by introducing the type-I fatty acid synthase from Corynebacterium ammoniagenes, we were able to bypass host regulatory mechanisms of fatty acid synthesis that have thus far hampered efforts to optimize the yield of acyl-ACP-derived products inmore » BL21(DE3). When all these engineering strategies were combined with subsequent optimization of fermentation conditions, we were able to achieve a final titer around 100 mg/L long chain alcohol/alkane products including a 57 mg/L titer of pentadecane, the highest titer reported in E. coli BL21(DE3) to date. The expression of prokaryotic type-I fatty acid synthases offer a unique strategy to produce fatty acid-derived products in E. coli that does not rely exclusively on the endogenous type-II fatty acid synthase system.« less

  12. Production of long chain alcohols and alkanes upon coexpression of an acyl-ACP reductase and aldehyde-deformylating oxgenase with a bacterial type-I fatty acid synthase in E. coli

    SciTech Connect

    Coursolle, Dan; Shanklin, John; Lian, Jiazhang; Zhao, Huimin

    2015-06-23

    Microbial long chain alcohols and alkanes are renewable biofuels that could one day replace petroleum-derived fuels. Here we report a novel pathway for high efficiency production of these products in Escherichia coli strain BL21(DE3). We first identified the acyl-ACP reductase/aldehyde deformylase combinations with the highest activity in this strain. Next, we used catalase coexpression to remove toxic byproducts and increase the overall titer. Finally, by introducing the type-I fatty acid synthase from Corynebacterium ammoniagenes, we were able to bypass host regulatory mechanisms of fatty acid synthesis that have thus far hampered efforts to optimize the yield of acyl-ACP-derived products in BL21(DE3). When all these engineering strategies were combined with subsequent optimization of fermentation conditions, we were able to achieve a final titer around 100 mg/L long chain alcohol/alkane products including a 57 mg/L titer of pentadecane, the highest titer reported in E. coli BL21(DE3) to date. The expression of prokaryotic type-I fatty acid synthases offer a unique strategy to produce fatty acid-derived products in E. coli that does not rely exclusively on the endogenous type-II fatty acid synthase system.

  13. Production of long chain alcohols and alkanes upon coexpression of an acyl-ACP reductase and aldehyde-deformylating oxygenase with a bacterial type-I fatty acid synthase in E. coli.

    PubMed

    Coursolle, Dan; Lian, Jiazhang; Shanklin, John; Zhao, Huimin

    2015-09-01

    Microbial long chain alcohols and alkanes are renewable biofuels that could one day replace petroleum-derived fuels. Here we report a novel pathway for high efficiency production of these products in Escherichia coli strain BL21(DE3). We first identified the acyl-ACP reductase/aldehyde deformylase combinations with the highest activity in this strain. Next, we used catalase coexpression to remove toxic byproducts and increase the overall titer. Finally, by introducing the type-I fatty acid synthase from Corynebacterium ammoniagenes, we were able to bypass host regulatory mechanisms of fatty acid synthesis that have thus far hampered efforts to optimize the yield of acyl-ACP-derived products in BL21(DE3). When all these engineering strategies were combined with subsequent optimization of fermentation conditions, we were able to achieve a final titer around 100 mg L(-1) long chain alcohol/alkane products including a 57 mg L(-1) titer of pentadecane, the highest titer reported in E. coli BL21(DE3) to date. The expression of prokaryotic type-I fatty acid synthases offer a unique strategy to produce fatty acid-derived products in E. coli that does not rely exclusively on the endogenous type-II fatty acid synthase system. PMID:26135500

  14. An intact cuticle in distal tissues is essential for the induction of systemic acquired resistance in plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Systemic acquired resistance (SAR) immunizes distal tissues of plants against secondary infections. We report that an acyl carrier protein, ACP4, is essential for perception but not generation of the SAR signal in Arabidopsis. A mutation in acp4 reduces the fatty acid flux, resulting in impaired cut...

  15. In silico analysis and modeling of ACP-MIP–PilQ chimeric antigen from Neisseria meningitidis serogroup B

    PubMed Central

    Gholami, Mehrdad; Salimi Chirani, Alireza; Moshiri, Mona; Sedighi, Mansour; Pournajaf, Abazar; Tohidfar, Masoud; Irajian, Gholamreza

    2015-01-01

    Background: Neisseria meningitidis, a life-threatening human pathogen with the potential to cause large epidemics, can be isolated from the nasopharynx of 5–15% of adults. The aim of the current study was to evaluate biophysical and biochemical properties and immunological aspects of chimeric acyl-carrier protein-macrophage infectivity potentiator protein-type IV pilus biogenesis protein antigen (ACP-MIP-PilQ) from N. meningitidis serogroup B strain. Methods: Biochemical properties and multiple alignments were predicted by appropriate web servers. Secondary molecular structures were predicted based on Chou and Fasman, Garnier-Osguthorpe-Robson, and Neural Network methods. Tertiary modeling elucidated conformational properties of the chimeric protein. Proteasome cleavage and transporter associated with antigen processing (TAP) binding sites, and T- and B-cell antigenic epitopes, were predicted using bioinformatic web servers. Results: Based on our in silico and immunoinformatics analyses, the ACP-MIP-PilQ protein (AMP) can induce high-level cross-strain bactericidal activity. In addition, several immune proteasomal cleavage sites were detected. The 22 epitopes associated with MHC class I and class II (DR) alleles were confirmed in the AMP. Thirty linear B-cell epitopes as antigenic regions were predicted from the full-length protein. Conclusion: All predicted properties of the AMP indicate it could be a good candidate for further immunological in vitro and in vivo studies. PMID:26989750

  16. Pushing away the communication bottleneck with optical interconnects in symmetric multiprocessors

    NASA Astrophysics Data System (ADS)

    Hlayhel, Wissam; Collet, Jacques H.; Rochange, Christine; Litaize, Daniel

    2000-05-01

    We analyze the bandwidth needed for transmitting the addresses in future symmetric multiprocessor machines (SMP), constructed around a shared bus due to the critical obligation to preserve the coherence of the memory hierarchy. We show that an address-transaction bandwidth as high as several hundreds of Gbit/s will be necessary not to slow down the execution of most applications in large SMP's. This communication bandwidth seems incompatible with the operation constraints of shared electrical busses, making necessary the search for other implementations of the address transmission network. We consider the introduction of optical interconnects (OI) in this context. We review several solutions, in the ascending order of complexity of the optical subsystems as one critical issue concerns the degree of sophistication of the optical solutions and their cost. We first consider simple point to point OI's for a SMP chipset. The interest for OI's comes from the low energy consumption and from the possibility, in the future, to integrate several thousands of optical input/outputs per electronic chip. The we consider the implementation of an optical bus that is a multipoint optical line involving more optical functionality. We discuss the possibility of multiple accesses to the bus, and the constraints related to the necessity to maintain the coherence of caches.

  17. Sparse Gaussian elimination with controlled fill-in on a shared memory multiprocessor

    NASA Technical Reports Server (NTRS)

    Alaghband, Gita; Jordan, Harry F.

    1989-01-01

    It is shown that in sparse matrices arising from electronic circuits, it is possible to do computations on many diagonal elements simultaneously. A technique for obtaining an ordered compatible set directly from the ordered incompatible table is given. The ordering is based on the Markowitz number of the pivot candidates. This technique generates a set of compatible pivots with the property of generating few fills. A novel heuristic algorithm is presented that combines the idea of an order-compatible set with a limited binary tree search to generate several sets of compatible pivots in linear time. An elimination set for reducing the matrix is generated and selected on the basis of a minimum Markowitz sum number. The parallel pivoting technique presented is a stepwise algorithm and can be applied to any submatrix of the original matrix. Thus, it is not a preordering of the sparse matrix and is applied dynamically as the decomposition proceeds. Parameters are suggested to obtain a balance between parallelism and fill-ins. Results of applying the proposed algorithms on several large application matrices using the HEP multiprocessor (Kowalik, 1985) are presented and analyzed.

  18. Systems analysis of the space shuttle. [communication systems, computer systems, and power distribution

    NASA Technical Reports Server (NTRS)

    Schilling, D. L.; Oh, S. J.; Thau, F.

    1975-01-01

    Developments in communications systems, computer systems, and power distribution systems for the space shuttle are described. The use of high speed delta modulation for bit rate compression in the transmission of television signals is discussed. Simultaneous Multiprocessor Organization, an approach to computer organization, is presented. Methods of computer simulation and automatic malfunction detection for the shuttle power distribution system are also described.

  19. Campylobacter jejuni fatty acid synthase II: Structural and functional analysis of [beta]-hydroxyacyl-ACP dehydratase (FabZ)

    SciTech Connect

    Kirkpatrick, Andrew S.; Yokoyama, Takeshi; Choi, Kyoung-Jae; Yeo, Hye-Jeong

    2009-08-14

    Fatty acid biosynthesis is crucial for all living cells. In contrast to higher organisms, bacteria use a type II fatty acid synthase (FAS II) composed of a series of individual proteins, making FAS II enzymes excellent targets for antibiotics discovery. The {beta}-hydroxyacyl-ACP dehydratase (FabZ) catalyzes an essential step in the FAS II pathway. Here, we report the structure of Campylobacter jejuni FabZ (CjFabZ), showing a hexamer both in crystals and solution, with each protomer adopting the characteristic hot dog fold. Together with biochemical analysis of CjFabZ, we define the first functional FAS II enzyme from this pathogen, and provide a framework for investigation on roles of FAS II in C. jejuni virulence

  20. Cloning of Acyl-ACP Thioesterase FatA from Arachis hypogaea L. and Its Expression in Escherichia coli

    PubMed Central

    Chen, Gao; Peng, Zhen-ying; Shan, Lei; Xuan, Ning; Tang, Gui-ying; Zhang, Yan; Li, Lan; He, Qing-fang; Bi, Yu-ping

    2012-01-01

    In this study, a full-length cDNA of the acyl-ACP thioesterase, AhFatA, was cloned from developing seeds of Arachis hypogaea L. by 3′-RACE. Sequence analysis showed that the open reading frame encodes a peptide of 372 amino acids and has 50–70% identity with FatA from other plants. Real-time quantitative PCR analysis revealed that AhFatA was expressed in all tissues of A. hypogaea L., but most strongly in the immature seeds harvested at 60 days after pegging. Heterologous expression of AhFatA in Escherichia coli affected bacterial growth and changed the fatty acid profiles of the membrane lipid, resulting in directed accumulation towards palmitoleic acid and oleic acid. These results indicate that AhFatA is at least partially responsible for determining the high palmitoleic acid and oleic acid composition of E. coli. PMID:23093853

  1. X-ray structure of putative acyl-ACP desaturase DesA2 from Mycobacterium tuberculosis H37Rv

    SciTech Connect

    Dyer, David H.; Lyle, Karen S.; Rayment, Ivan; Fox, Brian G.

    2010-07-13

    Genome sequencing showed that two proteins in Mycobacterium tuberculosis H37Rv contain the metal binding motif (D/E)X{sub 2}HX{sub {approx}100}(D/E)X{sub 2}H characteristic of the soluble diiron enzyme superfamily. These putative acyl-ACP desaturase genes desA1 and desA2 were cloned from genomic DNA and expressed in Escherichia coli BL21(DE3). DesA1 was found to be insoluble, but in contrast, DesA2 was a soluble protein amenable to biophysical characterization. Here, we report the 2.0 {angstrom} resolution X-ray structure of DesA2 determined by multiple anomalous dispersion (MAD) phasing from a Se-met derivative and refinement against diffraction data obtained on the native protein. The X-ray structure shows that DesA2 is a homodimeric protein with a four-helix bundle core flanked by five additional helices that overlay with 192 structurally equivalent amino acids in the structure of stearoyl-ACP {Delta}9 desaturase from castor plant with an rms difference 1.42 {angstrom}. In the DesA2 crystals, one metal (likely Mn from the crystallization buffer) was bound in high occupancy at the B-site of the conserved metal binding motif, while the A-site was not occupied by a metal ion. Instead, the amino group of Lys-76 occupied this position. The relationships between DesA2 and known diiron enzymes are discussed.

  2. Crystallization and preliminary X-ray crystallographic analysis of enoyl-ACP reductase III (FabL) from Bacillus subtilis

    SciTech Connect

    Kim, Kook-Han; Park, Joon Kyu; Ha, Byung Hak; Moon, Jin Ho; Kim, Eunice EunKyeong

    2007-03-01

    Enoyl-ACP reductase III (FabL) from B. subtilis has been overexpressed, purified and crystallized. The crystal belongs to space group P622, with unit-cell parameters a = b = 139.56, c = 62.75 Å, α = β = 90, γ = 120°, and data were collected to 2.5 Å resolution using synchrotron radiation. Enoyl-[acyl-carrier protein] reductase (enoyl-ACP reductase; ENR) is a key enzyme in type II fatty-acid synthase that catalyzes the last step in each elongation cycle. It has been considered as an antibiotic target since it is an essential enzyme in bacteria. However, recent studies indicate that some pathogens have more than one ENR. Bacillus subtilis is reported to have two ENRs, namely BsFabI and BsFabL. While BsFabI is similar to other FabIs, BsFabL shows very little sequence similarity and is NADPH-dependent instead of NADH-dependent as in the case of FabI. In order to understand these differences on a structural basis, BsFabL has been cloned, expressed and and crystallized. The crystal belongs to space group P622, with unit-cell parameters a = b = 139.56, c = 62.75 Å, α = β = 90, γ = 120° and one molecule of FabL in the asymmetric unit. Data were collected using synchrotron radiation (beamline 4A at the Pohang Light Source, Korea). The crystal diffracted to 2.5 Å resolution.

  3. Effect of a mutagenized acyl-ACP thioesterase FATA allele from sunflower with improved activity in tobacco leaves and Arabidopsis seeds.

    PubMed

    Moreno-Pérez, Antonio Javier; Venegas-Calerón, Mónica; Vaistij, Fabián E; Salas, Joaquin J; Larson, Tony R; Garcés, Rafael; Graham, Ian A; Martínez-Force, Enrique

    2014-03-01

    The substrate specificity of the acyl-acyl carrier protein (ACP) thioesterases significantly determines the type of fatty acids that are exported from plastids. Thus, designing acyl-ACP thioesterases with different substrate specificities or kinetic properties would be of interest for plant lipid biotechnology to produce oils enriched in specialty fatty acids. In the present work, the FatA thioesterase from Helianthus annuus was used to test the impact of changes in the amino acids present in the binding pocket on substrate specificity and catalytic efficiency. Amongst all the mutated enzymes studied, Q215W was especially interesting as it had higher specificity towards saturated acyl-ACP substrates and higher catalytic efficiency compared to wild-type H. annuus FatA. Null, wild type and high-efficiency alleles were transiently expressed in tobacco leaves to check their effect on lipid biosynthesis. Expression of active FatA thioesterases altered the composition of leaf triacylglycerols but did not alter total lipid content. However, the expression of the wild type and the high-efficiency alleles in Arabidopsis thaliana transgenic seeds resulted in a strong reduction in oil content and an increase in total saturated fatty acid content. The role and influence of acyl-ACP thioesterases in plant metabolism and their possible applications in lipid biotechnology are discussed. PMID:24327259

  4. Expanding Access and Increasing Success in Postsecondary Education for Arizonans. The Arizona Commission for Postsecondary Education (ACPE) 2007-2008 Annual Report

    ERIC Educational Resources Information Center

    Arizona Commission for Postsecondary Education, 2008

    2008-01-01

    The work of the Arizona Commission for Postsecondary Education (ACPE) is guided by a 5-year strategic plan. The purpose of the plan is to provide focus for the activity of this small agency and its nine staff members in order to increase productivity and impact in the areas of its statutory authority. The mission and goals were accepted by …

  5. A comparison of surface roughness after micro abrasion of enamel with and without using CPP-ACP: An in vitro study

    PubMed Central

    Mathias, Jones; Kavitha, S; Mahalaxmi, S

    2009-01-01

    Aim: The aim of this study was to evaluate the surface roughness of enamel after micro abrasion with and without using remineralization agent, CPP-ACP (Casein Phosphopeptide-Amorphous Calcium Phosphate). Materials and Methods: Thirty freshly extracted anterior teeth were collected. The samples were randomly assigned to two study and one control group. Group A (n = 10) containing teeth in which only micro abrasion was done, Group B (n = 10) containing teeth in which CPP-ACP (G C Tooth Mousse) was applied after micro abrasion for a period of 30 days, once daily for three minutes and Group C (n = 10) in which no preparation was done and which acted as the control group. The samples were stored in artificial saliva and evaluated after 30 days, using surface profilometer. The results were tabulated and statistically analyzed. Results: According to the results of this study, a combination of the micro abrasion procedure and CPP-ACP application reduced the enamel surface roughness significantly, when compared to micro abrasion done alone. Conclusion: Application of CPP-ACP after micro abrasion procedure significantly reduces the enamel surface roughness thereby decreasing the risk of caries. PMID:20379436

  6. Expanding Access and Increasing Success in Postsecondary Education for Arizonans. The Arizona Commission for Postsecondary Education (ACPE) 2008-2009 Annual Report

    ERIC Educational Resources Information Center

    Arizona Commission for Postsecondary Education, 2009

    2009-01-01

    The work of the Arizona Commission for Postsecondary Education (ACPE) is guided by a 5-year strategic plan. The purpose of the plan is to provide focus for the activity of this small agency and its eight staff members in order to increase productivity and impact in the areas of its statutory authority. The mission and goals were accepted by…

  7. Expanding Access and Increasing Success in Postsecondary Education for Arizonans. The Arizona Commission for Postsecondary Education (ACPE) 2009-2010 Annual Report

    ERIC Educational Resources Information Center

    Arizona Commission for Postsecondary Education, 2010

    2010-01-01

    The work of the Arizona Commission for Postsecondary Education (ACPE) is guided by a strategic plan. The purpose of the plan is to provide focus for the activity of this small agency and its five staff members in order to increase productivity and impact in the areas of its statutory authority. The mission and goals were accepted by Commissioners…

  8. Expanding Access and Increasing Success in Postsecondary Education for Arizonans. Arizona Commission for Postsecondary Education (ACPE) Fiscal Year 2005-2006 Annual Report

    ERIC Educational Resources Information Center

    Arizona Commission for Postsecondary Education, 2006

    2006-01-01

    The work of the Arizona Commission for Postsecondary Education (ACPE) is guided by a 5-year strategic plan. The purpose of the plan is to provide focus for the activity of this small agency and its seven staff members in order to increase productivity and impact in the areas of its statutory authority. The mission and goals were accepted by…

  9. Enhanced free fatty acid production by codon-optimized Lactococcus lactis acyl-ACP thioesterase gene expression in Escherichia coli using crude glycerol.

    PubMed

    Lee, Sunhee; Park, Soohyun; Park, Chulhwan; Pack, Seung Pil; Lee, Jinwon

    2014-12-01

    Fatty acid production and composition are determined by the type of acyl-acyl carrier protein thioesterases (acyl-ACP TEs) expressed in Escherichia coli. Bacterial acyl-ACP TEs from Lactococcus lactis (SGJS47), Enterococcus faecalis (SGJS49), and Burkholderia cepacia (SGJS50) were codon-optimized and expressed in E. coli for enhanced fatty acid production. Samples were extracted at the lag, log, and stationary phases of cell growth, and gene expression levels of the codon optimized acy-ACP TEs as well as fatty acid production were monitored. At 24h after initiation of gene expression, the OPLlTE expression level and fatty acid production in SGJS47 increased up to 15.8-fold and 3.2-fold compared to the control and other recombinant strains, respectively. Additionally, in SGJS47, improvement in free fatty acid (FFA) composition, high-specificity production of short-chain fatty acids (C8, C10) and unsaturated fatty acids (C16:1) was achieved in crude glycerol medium condition. Compared with control strain, the percentage of FFAs (C8 and C10) was enhanced by approximately 16- to 21-fold, C16:1 FFA ratio increased approximately 18-fold. Observation of codon-optimized acyl-ACP TE genes expression level in E. coli may be useful for understanding mechanisms towards improving fatty acid production. Engineered strains have the potential to overproduce specific FFAs and thereby reduce the cost of fatty acid production by using industrially inexpensive carbon sources. PMID:25442943

  10. Morphological and metabolic changes in transgenic wheat with altered glycerol-3-phosphate acyltransferase or acyl-acyl carrier protein (ACP) thioesterase activities.

    PubMed

    Edlin, D A; Kille, P; Wilkinson, M D; Jones, H D; Harwood, J L

    2000-12-01

    We have transformed varieties of wheat with a Pisum sativum glycerol-3-phosphate acyltransferase gene, and also with an Arabidopsis thaliana acyl-ACP thioesterase gene. Morphological (growth, organelle development) and metabolic changes (fatty acid labelling of chloroplast and non-chloroplast lipids) have been observed in transgenics with altered gene expression for either enzyme. PMID:11171169

  11. Expanding Access and Increasing Success in Postsecondary Education for Arizonans. The Arizona Commission for Postsecondary Education (ACPE) 2006-2007 Annual Report

    ERIC Educational Resources Information Center

    Arizona Commission for Postsecondary Education, 2007

    2007-01-01

    The work of the Arizona Commission for Postsecondary Education (ACPE) is guided by a 5 year strategic plan. The purpose of the plan is to provide focus for the activity of this small agency and its eight staff members in order to increase productivity and impact in the areas of its statutory authority. The mission and goals were accepted by…

  12. The hierarchical spatial decomposition of three-dimensional particle- in-cell plasma simulations on MIMD distributed memory multiprocessors

    SciTech Connect

    Walker, D.W.

    1992-07-01

    The hierarchical spatial decomposition method is a promising approach to decomposing the particles and computational grid in parallel particle-in-cell application codes, since it is able to maintain approximate dynamic load balance while keeping communication costs low. In this paper we investigate issues in implementing a hierarchical spatial decomposition on a hypercube multiprocessor. Particular attention is focused on the communication needed to update guard ring data, and on the load balancing method. The hierarchical approach is compared with other dynamic load balancing schemes.

  13. The PIP training programme: building of ACP experts capacities in crop protection and food safety to support local companies to comply with EU regulations on pesticides residues.

    PubMed

    Schiffers, B C; Schubert, A; Schiffers, C; Fontaine, S; Gumusboga, N; Werner, B; Webb, M; Lugros, H; Stinglhamber, G

    2006-01-01

    Regulatory requirements, and in particular phytosanitary quality standards change rapidly. As ACP producers/exporters race to become more competitive, to keep their market share and to satisfay their customers' commercial demands (e.g. EUREP-GAP certification), the need for competent staff who are aware of the company's quality objectives and trained to follow instructions is crucial. Mastering sanitary quality is only possible if matched with a programme to build the skills of companies' human resources. The Pesticide Initiative Programme (PIP), mindful of the importance of making operators autonomous and of training them to monitor EU food safety regulations and technology on their own, has successfully developed a training programme while building a quality network of local/ACP service providers. By building the capacities of ACP experts and then securing their services as trainers, PIP also guarantees companies' access to expertise and the sustainability of their efforts to comply with new EU regulations. The training strategy developed by PIP rests on two pilars: instructor training and collective training. Instructor training consists in reinforcing the technical knowledge of local experts (agronomists, hygienists, etc.) by providing them with active teaching methods. Once the ACP experts have gained enough technical knowledge of the key areas of crop protection--mainly pesticides management--and food safety, and have demonstrated their capacity to train the technical staff of local companies, the PIP has carried out a collective training programme in 2004, 2005 and 2006. To date, more than 130 consultants covering about 15 ACP countries have received instructor training, and more than 700 people have participated in collective and in-company training sessions. PMID:17390771

  14. Interleaved synchronous bus access protocol for a shared memory multi-processor system

    SciTech Connect

    Moore, W.T.

    1989-01-10

    A method is described for providing asynchronous processors with inter-processor communication and access to several memory modules over a common bus which includes a first bus and a second bus, comprising: providing clock pulses on the common bus, each pulse having a period; asserting a request signal and placing priority signal on the common bus; polling the processors during the first period to determine whether the processors request access to the common bus and to determine which one processor has priority; sending a destination address from the one processor to a destination during a second period, the destination being chosen from the processors and the several memory modules; performing one of reading input data between the destination and the processor; multiplexing priority and reading input data signals on the first bus, and multiplexing address and writing output data signals on the second bus; generating poll inhibit signals prior to each reading input data signal and prior to each memory address signal preceding a writing output data operation; and queuing the input data in a first-in-first-out manner for each of the processors when the input data indicates an interprocessor interrupt.

  15. Identification and characterization of the adipokinetic hormone/corazonin-related peptide signaling system in Rhodnius prolixus.

    PubMed

    Zandawala, Meet; Haddad, Amir S; Hamoudi, Zina; Orchard, Ian

    2015-09-01

    The mammalian gonadotropin-releasing hormone is evolutionarily related to the arthropod adipokinetic hormone and the recently discovered adipokinetic hormone/corazonin-related peptide (ACP). The function of the ACP signaling system in arthropods is currently unknown. In the present study, we identify and characterize the ACP signaling system in the kissing bug Rhodnius prolixus. We isolated the complete cDNA sequence encoding R. prolixus ACP (Rhopr-ACP) and examined its expression pattern. Rhopr-ACP is predominantly expressed in the central nervous system. In particular, it is found in both the brain and corpus cardiacum (CC)/corpora allata (CA) complex. To gain an insight into its role in R. prolixus, we also isolated and functionally characterized cDNA sequences of three splice variants (Rhopr-ACPR-A, B and C) encoding R. prolixus ACP G protein-coupled receptor (Rhopr-ACPR). Rhopr-ACPR-A has only five transmembrane domains, whereas Rhopr-ACPR-B and C have all seven domains. Interestingly, Rhopr-ACPR-A, B and C were all activated by Rhopr-ACP, albeit at different sensitivities, when expressed in Chinese hamster ovary cells stably expressing the human G-protein G16 (CHO/G16). To our knowledge, this is the first study to isolate a truncated receptor cDNA in invertebrates that is functional in a heterologous expression system. Moreover, Rhopr-ACPR-B and C but not Rhopr-ACPR-A can be coupled with Gq α subunits. Expression profiling indicates that Rhopr-ACPR is highly expressed in the central nervous system, as well as the CC/CA complex, suggesting that it may control the release of other hormones found in the CC in a manner analogous to gonadotropin-releasing hormone. Temporal expression profiling shows that both Rhopr-ACP and Rhopr-ACPR are upregulated after ecdysis, suggesting that this neuropeptide may be involved in processes associated with post-ecdysis. PMID:26138617

  16. Hybrid Simulation of the Interaction of Europa's Atmosphere with the Jovian Plasma: Multiprocessor Simulations

    NASA Astrophysics Data System (ADS)

    Dols, V. J.; Delamere, P. A.; Bagenal, F.; Cassidy, T. A.; Crary, F. J.

    2014-12-01

    We model the interaction of Europa's tenuous atmosphere with the plasma of Jupiter's torus with an improved version of our hybrid plasma code. In a hybrid plasma code, the ions are treated as kinetic Macro-particles moving under the Lorentz force and the electrons as a fluid leading to a generalized formulation of Ohm's law. In this version, the spatial simulation domain is decomposed in 2 directions and is non-uniform in the plasma convection direction. The code is run on a multi-processor supercomputer that offers 16416 cores and 2GB Ram per core. This new version allows us to tap into the large memory of the supercomputer and simulate the full interaction volume (Reuropa=1561km) with a high spatial resolution (50km). Compared to Io, Europa's atmosphere is about 100 times more tenuous, the ambient magnetic field is weaker and the density of incident plasma is lower. Consequently, the electrodynamic interaction is also weaker and substantial fluxes of thermal torus ions might reach and sputter the icy surface. Molecular O2 is the dominant atmospheric product of this surface sputtering. Observations of oxygen UV emissions (specifically the ratio of OI 1356A / 1304A emissions) are roughly consistent with an atmosphere that is composed predominantely of O2 with a small amount of atomic O. Galileo observations along flybys close to Europa have revealed the existence of induced currents in a conducting ocean under the icy crust. They also showed that, from flyby to flyby, the plasma interaction is very variable. Asymmetries of the plasma density and temperature in the wake of Europa were also observed and still elude a clear explanation. Galileo mag data also detected ion cyclotron waves, which is an indication of heavy ion pickup close to the moon. We prescribe an O2 atmosphere with a vertical density column consistent with UV observations and model the plasma properties along several Galileo flybys of the moon. We compare our results with the magnetometer

  17. Acp. Best practice no 155. Pathological investigation of deaths following surgery, anaesthesia, and medical procedures.

    PubMed Central

    Start, R D; Cross, S S

    1999-01-01

    The pathological investigation of deaths following surgery, anaesthesia, and medical procedures is discussed. The definition of "postoperative death" is examined and the classification of deaths following procedures detailed. The review of individual cases is described and the overall approach to necropsy and interpretation considered. There are specific sections dealing with the cardiovascular system (including air embolism, perioperative myocardial infarction, cardiac pacemakers, central venous catheters, cardiac surgery, heart valve replacement, angioplasty, and vascular surgery); respiratory system (postoperative pneumonia, pulmonary embolism, pneumothorax); central nervous system (dissection of cervical spinal cord), hepatobiliary and gastrointestinal system; musculoskeletal system; and head and neck region. Deaths associated with anaesthesia are classified and the specific problems of epidural anaesthesia and malignant hyperthermia discussed. The article concludes with a section on the recording of necropsy findings and their communication to clinicians and medicolegal authorities. PMID:10655984

  18. Transcriptional activation of Brassica napus β-ketoacyl-ACP synthase II with an engineered zinc finger protein transcription factor.

    PubMed

    Gupta, Manju; DeKelver, Russell C; Palta, Asha; Clifford, Carla; Gopalan, Sunita; Miller, Jeffrey C; Novak, Stephen; Desloover, Daniel; Gachotte, Daniel; Connell, James; Flook, Josh; Patterson, Thomas; Robbins, Kelly; Rebar, Edward J; Gregory, Philip D; Urnov, Fyodor D; Petolino, Joseph F

    2012-09-01

    Targeted gene regulation via designed transcription factors has great potential for precise phenotypic modification and acceleration of novel crop trait development. Canola seed oil composition is dictated largely by the expression of genes encoding enzymes in the fatty acid biosynthetic pathway. In the present study, zinc finger proteins (ZFPs) were designed to bind DNA sequences common to two canola β-ketoacyl-ACP Synthase II (KASII) genes downstream of their transcription start site. Transcriptional activators (ZFP-TFs) were constructed by fusing these ZFP DNA-binding domains to the VP16 transcriptional activation domain. Following transformation using Agrobacterium, transgenic events expressing ZFP-TFs were generated and shown to have elevated KASII transcript levels in the leaves of transgenic T(0) plants when compared to 'selectable marker only' controls as well as of T(1) progeny plants when compared to null segregants. In addition, leaves of ZFP-TF-expressing T(1) plants contained statistically significant decreases in palmitic acid (consistent with increased KASII activity) and increased total C18. Similarly, T(2) seed displayed statistically significant decreases in palmitic acid, increased total C18 and reduced total saturated fatty acid contents. These results demonstrate that designed ZFP-TFs can be used to regulate the expression of endogenous genes to elicit specific phenotypic modifications of agronomically relevant traits in a crop species. PMID:22520333

  19. Modification of Triclosan Scaffold in Search of Improved Inhibitors for Enoyl-Acyl Carrier Protein (ACP) Reductase in Toxoplasma gondii

    PubMed Central

    Stec, Jozef; Fomovska, Alina; Afanador, Gustavo A.; Muench, Stephen P.; Zhou, Ying; Lai, Bo-Shiun; Bissati, Kamal El; Hickman, Mark R.; Lee, Patty J.; Leed, Susan E.; Auschwitz, Jennifer M.; Sommervile, Caroline; Woods, Stuart; Roberts, Craig W.; Rice, David; Prigge, Sean T.; McLeod, Rima; Kozikowski, Alan P.

    2013-01-01

    Through our focused effort to discover new and effective agents against toxoplasmosis, a structure-based drug design approach was utilized to develop a series of potent inhibitors of the enoyl-acyl carrier protein (ACP) reductase (ENR) enzyme in Toxoplasma gondii (TgENR). Modifications to positions 5 and 4′ of the well-known ENR inhibitor triclosan afforded a series of 29 new analogs. Among the resulting compounds, many showed high potency and improved physicochemical properties in comparison with the lead. The most potent compounds 16a and 16c have IC50 values of 250 nM against Toxoplasma gondii tachyzoites without apparent toxicity to the host cells. Their IC50 values against the recombinant TgENR were 43 and 26 nM, respectively. Additionally, 11 other analogs in this series had IC50 values ranging from 17 to 130 nM in the enzyme-based assay. With respect to their excellent in vitro activity as well as improved drug-like properties, the lead compounds 16a and 16c are deemed to be an excellent starting point for the development of new medicines to effectively treat Toxoplasma gondii infections. PMID:23776166

  20. 3-Oxoacyl-ACP Reductase from Schistosoma japonicum: Integrated In Silico-In Vitro Strategy for Discovering Antischistosomal Lead Compounds

    PubMed Central

    Liu, Jian; Dyer, Dave; Wang, Jipeng; Wang, Shuqi; Du, Xiaofeng; Xu, Bin; Zhang, Haobing; Wang, Xiaoning; Hu, Wei

    2013-01-01

    Background Schistosomiasis is a disease caused by parasitic worms and more than 200 million people are infected worldwide. The emergence of resistance to the most commonly used drug, praziquantel (PZQ), makes the development of novel drugs an urgent task. 3-oxoacyl-ACP reductase (OAR), a key enzyme involved in the fatty acid synthesis pathway, has been identified as a potential drug target against many pathogenic organisms. However, no research on Schistosoma japonicum OAR (SjOAR) has been reported. The characterization of the SjOAR protein will provide new strategies for screening antischistosomal drugs that target SjOAR. Methodology/Principal Findings After cloning the SjOAR gene, recombinant SjOAR protein was purified and assayed for enzymatic activity. The tertiary structure of SjOAR was obtained by homology modeling and 27 inhibitor candidates were identified from 14,400 compounds through molecular docking based on the structure. All of these compounds were confirmed to be able to bind to the SjOAR protein by BIAcore analysis. Two compounds exhibited strong antischistosomal activity and inhibitory effects on the enzymatic activity of SjOAR. In contrast, these two compounds showed relatively low toxicity towards host cells. Conclusions/Significance The work presented here shows the feasibility of isolation of new antischistosomal compounds using a combination of virtual screening and experimental validation. Based on this strategy, we successfully identified 2 compounds that target SjOAR with strong antischistosomal activity but relatively low cytotoxicity to host cells. PMID:23762275

  1. A preliminary study of enamel remineralization by dentifrices based on Recalden (CPP-ACP) and Novamin (calcium-sodium-phosphosilicate).

    PubMed

    Gjorgievska, Elizabeta S; Nicholson, John W

    2010-01-01

    The purpose of this study was to investigate the enamel remineralization potential of two toothpastes, one of which was based on Recaldent (CPP- ACP) and the other on NovaMin (Calcium-sodium-phosphosilicate). Human permanent molar teeth were subjected to three consecutive demineralization cycles. These cycles were followed by remineralization of the experimental groups by toothpastes containing Recalden and NovaMin respectively. The samples were analyzed by Scanning Electron Microscope, (SEM) and energy-dispersive X-ray spectroscopy analysis (EDX). Extensive demineralization was noted in the control group (without remineralization) while the groups treated with the dentifices demonstrated various degrees of remineralization, as shown by formation of different types of deposits on the enamel surface. The EDX analysis showed increased amounts of Ca, P Si and Zn in the enamel of the experimental groups, compared to the control one. Toothpastes containing Recalden and especially NovaMin have the potential to remineralize enamel, a property which might be important in finding a substitute to pit and fissure sealing. PMID:21638965

  2. Cloning and characterization of cDNAs encoding for long-chain saturated acyl-ACP thioesterases from the developing seeds of Brassica juncea.

    PubMed

    Jha, Saheli Sinha; Jha, Jyoti K; Chattopadhyaya, Banani; Basu, Asitava; Sen, Soumitra K; Maiti, Mrinal K

    2010-06-01

    Four types of cDNAs corresponding to the fatty acyl-acyl carrier protein (ACP) thioesterase (Fat) enzyme were isolated from the developing seeds of Brassica juncea, a widely cultivated species amongst the oil-seed crops. The mature polypeptides deduced from the cDNAs showed sequence identity with the FatB class of plant thioesterases. Southern hybridization revealed the presence of at least four copies of BjFatB gene in the genome of this amphidiploid species. Western blot and RT-PCR analyses showed that the BjFatB class thioesterase is expressed poorly in flowers and leaves, but significantly in seeds at the mid-maturation stage. The enzymatic activities of different BjFatB isoforms were established upon heterologous expression of the four BjFatB CDSs in Escherichia coli K27fadD88, a mutant strain of fatty acid beta-oxidation pathway. The substrate specificity of each BjFatB isoform was determined in vivo by fatty acid profile analyses of the culture supernatant and membrane lipid of the recombinant K27fadD88 and E. coli DH10B (fadD(+)) clones, respectively. The BjFatB1 and BjFatB3 were predominantly active on C18:0-ACP substrate, whereas BjFatB2 and BjFatB4 were specific towards C18:0-ACP as well as C16:0-ACP. These novel FatB genes may find potential application in metabolic engineering of crop plants through their over-expression in seed tissues to generate stearate-rich vegetable fats/oils of commercial importance. PMID:20356753

  3. Cryopreservation of collared peccaries (Tayassu tajacu) semen using a powdered coconut water (ACP-116c) based extender plus various concentrations of egg yolk and glycerol.

    PubMed

    Silva, M A; Peixoto, G C X; Lima, G L; Bezerra, J A B; Campos, L B; Paiva, A L C; Paula, V V; Silva, A R

    2012-08-01

    The objective was to determine the effectiveness of a powdered coconut water-based extender (ACP-116c), plus various concentrations of egg-yolk and glycerol, as an alternative for cryopreservation of collared peccary semen. Twelve ejaculates were obtained from captive adult males by electroejaculation, and evaluated for sperm motility, kinetic rating, viability, morphology, and functional membrane integrity. The ejaculates were apportioned into aliquots that were diluted in Tris plus 10% egg yolk and 3% glycerol, or in ACP-116c plus 10 or 20% egg yolk and 1.5 or 3% glycerol. Samples were frozen in liquid nitrogen and, after 1 mo, thawed at 37 °C for 1 min. After thawing, samples were evaluated as reported for fresh semen, and also for sperm membrane integrity (fluorescent probes) and kinematic parameters (computerized analysis). Results were presented as means ± SEM. Freezing and thawing decreased sperm characteristics relative to fresh semen. Overall, ACP-116c plus 20% egg yolk and 3% glycerol provided better (P < 0.05) sperm motility and kinetic rating (48 ± 6.1% and 2.8 ± 0.2, respectively) after thawing than Tris extender (30.4 ± 5.7% and 2.4 ± 0.2). However, there were no differences (P > 0.05) among treatments with regard to the other sperm characteristics. Based on computerized motion analysis, total (26.5 ± 5.9%) and progressive (8.1 ± 2.2%) motility were best preserved (P < 0.05) with the above-mentioned treatment. In conclusion, a coconut water-based extender, ACP-116c, plus 20% egg yolk and 3% glycerol, was effective for cryopreservation of semen from collared peccaries. PMID:22538005

  4. Radiolabelling and positron emission tomography of PT70, a time-dependent inhibitor of InhA, the Mycobacterium tuberculosis enoyl-ACP reductase

    DOE PAGESBeta

    Wang, Hui; Liu, Li; Lu, Yang; Pan, Pan; Hooker, Jacob M.; Fowler, Joanna S.; Tonge, Peter J.

    2015-07-14

    PT70 is a diaryl ether inhibitor of InhA, the enoyl-ACP reductase in the Mycobacterium tuberculosis fatty acid biosynthesis pathway. It has a residence time of 24 min on the target, and also shows antibacterial activity in a mouse model of tuberculosis infection. Due to the interest in studying target tissue pharmacokinetics of PT70, we developed a method to radiolabel PT70 with carbon-11 and have studied its pharmacokinetics in mice and baboons using positron emission tomography.

  5. Mutations in a delta9-Stearoyl-ACP-Desaturase Gene Are Associated with Enhanced Stearic Acid Levels in Soybean Seeds

    SciTech Connect

    Zhang, P.; Shanklin, J.; Burton, J. W.; Upchurch, R. G.; Whittle, E.; Dewey, R. E.

    2008-11-01

    Stearic acid (18:0) is typically a minor component of soybean [Glycine max (L.) Merr.] oil, accounting for only 2 to 4% of the total fatty acid content. Increasing stearic acid levels of soybean oil would lead to enhanced oxidative stability, potentially reducing the need for hydrogenation, a process leading to the formation of undesirable trans fatty acids. Although mutagenesis strategies have been successful in developing soybean germplasm with elevated 18:0 levels in the seed oil, the specific gene mutations responsible for this phenotype were not known. We report a newly identified soybean gene, designated SACPD-C, that encodes a unique isoform of {Delta}{sup 9}-stearoyl-ACP-desaturase, the enzyme responsible for converting stearic acid to oleic acid (18:1). High levels of SACPD-C transcript were only detected in developing seed tissue, suggesting that the encoded desaturase functions to enhance oleic acid biosynthetic capacity as the immature seed is actively engaged in triacylglycerol production and storage. The participation of SACPD-C in storage triacylglycerol synthesis is further supported by the observation of mutations in this gene in two independent sources of elevated 18:0 soybean germplasm, A6 (30% 18:0) and FAM94-41 (9% 18:0). A molecular marker diagnostic for the FAM94-41 SACPD-C gene mutation strictly associates with the elevated 18:0 phenotype in a segregating population, and could thus serve as a useful tool in the development of cultivars with oils possessing enhanced oxidative stability.

  6. Effect of ACP-CPP Chewing Gum and Natural Chewable Products on Plaque pH, Calcium and Phosphate Concentration

    PubMed Central

    Sultan, Saima; Chaudhary, Seema; Manuja, Naveen; Kaur, Harsimran; Amit, Sinha Ashish; Lingesha, Ravishankar Telgi

    2016-01-01

    Introduction Numerous epidemiological studies have documented dental caries as the major public health problems throughout the world. It is gradually increasing in the underdeveloped and developing countries especially in children due to increasing popularity of refined sugars. Aim The aim of the study was to evaluate the effect of natural chewable products (Tulsi, sesame seeds, fennel seeds, coconut) and ACP-CPP chewing gum on plaque pH, calcium and phosphate concentration. Materials and Methods A randomized controlled trial, with a cross-over study design, was conducted. Ten subjects aged 15-17 years who agreed to refrain from oral hygiene practice for 48 hours prior to the sample collection were selected for the study. The baseline plaque pH, calcium and phosphate was measured and repeated after 5 and 30 minutes. It was ensured that each study participant was subjected to all the products making an effective sample of ten subjects per product. The data was statistically analysed. Results The mean pH in all the study groups increased after 5 minutes and 30 minutes compared to baseline, except for coconut group at 30 minutes and fennel group at 5 minutes. Highest increase in plaque calcium concentration was found in fennel group followed by recaldent and sesame, respectively. Whereas, the highest increase in plaque phosphate was found in recaldent group followed by sesame group and fennel group respectively. Conclusion Plant products can be effective, inexpensive, easily accessible methods of maintaining oral health. Further studies are recommended to confirm long term effects. PMID:27190943

  7. Selectivity of Pyridone- and Diphenyl Ether-Based Inhibitors for the Yersinia pestis FabV Enoyl-ACP Reductase.

    PubMed

    Neckles, Carla; Pschibul, Annica; Lai, Cheng-Tsung; Hirschbeck, Maria; Kuper, Jochen; Davoodi, Shabnam; Zou, Junjie; Liu, Nina; Pan, Pan; Shah, Sonam; Daryaee, Fereidoon; Bommineni, Gopal R; Lai, Cristina; Simmerling, Carlos; Kisker, Caroline; Tonge, Peter J

    2016-05-31

    The enoyl-ACP reductase (ENR) catalyzes the last reaction in the elongation cycle of the bacterial type II fatty acid biosynthesis (FAS-II) pathway. While the FabI ENR is a well-validated drug target in organisms such as Mycobacterium tuberculosis and Staphylococcus aureus, alternate ENR isoforms have been discovered in other pathogens, including the FabV enzyme that is the sole ENR in Yersinia pestis (ypFabV). Previously, we showed that the prototypical ENR inhibitor triclosan was a poor inhibitor of ypFabV and that inhibitors based on the 2-pyridone scaffold were more potent [Hirschbeck, M. (2012) Structure 20 (1), 89-100]. These studies were performed with the T276S FabV variant. In the work presented here, we describe a detailed examination of the mechanism and inhibition of wild-type ypFabV and the T276S variant. The T276S mutation significantly reduces the affinity of diphenyl ether inhibitors for ypFabV (20-fold → 100-fold). In addition, while T276S ypFabV generally displays an affinity for 2-pyridone inhibitors higher than that of the wild-type enzyme, the 4-pyridone scaffold yields compounds with similar affinity for both wild-type and T276S ypFabV. T276 is located at the N-terminus of the helical substrate-binding loop, and structural studies coupled with site-directed mutagenesis reveal that alterations in this residue modulate the size of the active site portal. Subsequently, we were able to probe the mechanism of time-dependent inhibition in this enzyme family by extending the inhibition studies to include P142W ypFabV, a mutation that results in a gain of slow-onset inhibition for the 4-pyridone PT156. PMID:27136302

  8. Advance care planning: identifying system-specific barriers and facilitators

    PubMed Central

    Hagen, N.A.; Howlett, J.; Sharma, N.C.; Biondo, P.; Holroyd-Leduc, J.; Fassbender, K.; Simon, J.

    2015-01-01

    Background Advance care planning (acp) is an important process in health care today. How to prospectively identify potential local barriers and facilitators to uptake of acp across a complex, multi-sector, publicly funded health care system and how to develop specific mitigating strategies have not been well characterized. Methods We surveyed a convenience sample of clinical and administrative health care opinion leaders across the province of Alberta to characterize system-specific barriers and facilitators to uptake of acp. The survey was based on published literature about the barriers to and facilitators of acp and on the Michie Theoretical Domains Framework. Results Of 88 surveys, 51 (58%) were returned. The survey identified system-specific barriers that could challenge uptake of acp. The factors were categorized into four main domains. Three examples of individual system-specific barriers were “insufficient public engagement and misunderstanding,” “conflict among different provincial health service initiatives,” and “lack of infrastructure.” Local system-specific barriers and facilitators were subsequently explored through a semi-structured informal discussion group involving key informants. The group identified approaches to mitigate specific barriers. Conclusions Uptake of acp is a priority for many health care systems, but bringing about change in multi-sector health care systems is complex. Identifying system-specific barriers and facilitators to the uptake of innovation are important elements of successful knowledge translation. We developed and successfully used a simple and inexpensive process to identify local system-specific barriers and enablers to uptake of acp, and to identify specific mitigating strategies. PMID:26300673

  9. Process for predicting structural performance of mechanical systems

    DOEpatents

    Gardner, David R.; Hendrickson, Bruce A.; Plimpton, Steven J.; Attaway, Stephen W.; Heinstein, Martin W.; Vaughan, Courtenay T.

    1998-01-01

    A process for predicting the structural performance of a mechanical system represents the mechanical system by a plurality of surface elements. The surface elements are grouped according to their location in the volume occupied by the mechanical system so that contacts between surface elements can be efficiently located. The process is well suited for efficient practice on multiprocessor computers.

  10. Process for predicting structural performance of mechanical systems

    DOEpatents

    Gardner, D.R.; Hendrickson, B.A.; Plimpton, S.J.; Attaway, S.W.; Heinstein, M.W.; Vaughan, C.T.

    1998-05-19

    A process for predicting the structural performance of a mechanical system represents the mechanical system by a plurality of surface elements. The surface elements are grouped according to their location in the volume occupied by the mechanical system so that contacts between surface elements can be efficiently located. The process is well suited for efficient practice on multiprocessor computers. 12 figs.

  11. Prediction of parallel NIKE3D performance on the KSR1 system

    SciTech Connect

    Su, P.S.; Zacharia, T.; Fulton, R.E.

    1995-05-01

    Finite element method is one of the bases for numerical solutions to engineering problems. Complex engineering problems using finite element analysis typically imply excessively large computational time. Parallel supercomputers have the potential for significantly increasing calculation speeds in order to meet these computational requirements. This paper predicts parallel NIKE3D performance on the Kendall Square Research (KSR1) system. The first part of the prediction is based on the implementation of parallel Cholesky (U{sup T}DU) matrix decomposition algorithm through actual computations on the KSRI multiprocessor system, with 64 processors, at Oak Ridge National Laboratory. The other predictions are based on actual computations for parallel element matrix generation, parallel global stiffness matrix assembly, and parallel forward/backward substitution on the BBN TC2000 multiprocessor system at Lawrence Livermore National Laboratory. The preliminary results indicate that parallel NIKE3D performance can be attractive under local/shared-memory multiprocessor system environments.

  12. Effect of CPP-ACP Paste on Enamel Carious Lesion of Primary Upper Anterior Teeth Assessed by Quantitative Light-Induced Fluorescence: A One-Year Clinical Trial.

    PubMed

    Sitthisettapong, Thanya; Doi, Takashi; Nishida, Yuhei; Kambara, Masaki; Phantumvanit, Prathip

    2015-01-01

    The purpose of this clinical trial was to evaluate the effect of 1 year of daily application of 10% w/v CPP-ACP (casein phosphopeptide-amorphous calcium phosphate) paste in addition to regular toothbrushing with fluoridated toothpaste on the remineralization of enamel carious lesions in preschool children using quantitative light-induced fluorescence (QLF). A total of 103 Thai children (aged 2(1)/2-3(1)/2 years) with high caries risk who had at least 1 enamel carious lesion (ICDAS 1-3) on the labial surface of the upper anterior teeth were assigned to receive either CPP-ACP paste (n = 53) or placebo control (n = 50) following toothbrushing with fluoridated toothpaste after lunch at school. QLF measurement was performed at baseline, 6 months and 1 year. At 1 year, a significant reduction in fluorescence loss (ΔF), lesion area and lesion volume (ΔQ; p ≤ 0.001) of the lesions were found over time in both groups. However, no significant difference was observed between the groups (p = 0.79, 0.98 and 0.88, respectively). There was no statistically significant difference between the odds of ΔQ transition to a stage of regression or arrest compared with progression from baseline to 1 year between the two groups (OR = 1.03, 95% CI 0.31-3.39). The daily application of 10% w/v CPP-ACP paste on a school day for 1 year resulted in no improvement of enamel carious lesion remineralization in the primary upper anterior teeth as assessed by QLF. The lesion improvement was not superior to remineralization from regular toothbrushing with fluoridated toothpaste alone in these children. PMID:26228178

  13. Cloning, characterization, and expression analysis of acyl-acyl carrier protein (ACP)-thioesterase B from seeds of Chinese Spicehush (Lindera communis).

    PubMed

    Dong, Shubin; Huang, Jiacong; Li, Yannan; Zhang, Jing; Lin, Shanzhi; Zhang, Zhixiang

    2014-05-25

    Acyl-acyl carrier protein (ACP) thioesterases (TE EC 3.1.2.14) are fatty acid biosynthesis key enzymes that determine fatty acid carbon chain length in most plant tissues. A full-length cDNA corresponding to one of the fatty acyl-ACP thioesterase (Fat) genes, designated LcFatB, was isolated from developing Lindera communis seeds using PCR and RACE with degenerate primers based on conserved sequences of multiple TE gene sequences obtained from GenBank. The 1788 bp cDNA had an open reading frame (ORF) of 1260 bp encoding a protein of 419 amino acids. The deduced amino acid sequence showed 61-73% identity to proteins in the FatB class of plant thioesterases. Real-time quantitative PCR analysis revealed that LcFatB was expressed in all tissues of L. communis, with the highest expression in the developing seeds 75days after flowering. Recombinant pET-MLcFatB was constructed using the pET-30 a vector and transformed into Escherichia coli BL21(DE3)△FadE, a strain that deleted the acyl-CoA dehydrogenase (FadE). SDS-PAGE analysis of proteins isolated from pET-MLcFatB E. coli cells after induction with IPTG revealed a protein band at ~40.5kDa, corresponding to the predicted size of LcFatB mature protein. The decanoic acid and lauric acid contents of the pET-MLcFatB transformant were increased significantly. These findings suggest that an LcFatB gene from a non-traditional oil-seed tree could be used to function as a saturated acyl-ACP thioesterase and could potentially be used to modify the fatty acid composition of seed oil from L. communis or other species through transgenic approaches. PMID:24631366

  14. The Crystal Structure of the Ivy delta4-16:0-ACP Desaturase Reveals Structural Details of the Oxidized Active Site and Potential Determinants of Regioselectivity

    SciTech Connect

    Guy,J.; Whittle, E.; Kumaran, D.; Lindqvist, Y.; Shanklin, J.

    2007-01-01

    The multifunctional acyl-acyl carrier protein (ACP) desaturase from Hedera helix (English ivy) catalyzes the {Delta}{sup 4} desaturation of 16:0-ACP and the{Delta}{sup 9} desaturation of 18:0-ACP and further desaturates{Delta}{sup 9}-16:1 or {Delta}{sup 9}-18:1 to the corresponding {Delta}{sup 4,9} dienes. The crystal structure of the enzyme has been solved to 1.95{angstrom} resolution, and both the iron-iron distance of 3.2{angstrom} and the presence of a {mu}-oxo bridge reveal this to be the only reported structure of a desaturase in the oxidized FeIII-FeIII form. Significant differences are seen between the oxidized active site and the reduced active site of the Ricinus communis (castor) desaturase; His{sup 227} coordination to Fe2 is lost, and the side chain of Glu{sup 224}, which bridges the two iron ions in the reduced structure, does not interact with either iron. Although carboxylate shifts have been observed on oxidation of other diiron proteins, this is the first example of the residue moving beyond the coordination range of both iron ions. Comparison of the ivy and castor structures reveal surface amino acids close to the annulus of the substrate-binding cavity and others lining the lower portion of the cavity that are potential determinants of their distinct substrate specificities. We propose a hypothesis that differences in side chain packing explains the apparent paradox that several residues lining the lower portion of the cavity in the ivy desaturase are bulkier than their equivalents in the castor enzyme despite the necessity for the ivy enzyme to accommodate three more carbons beyond the diiron site.

  15. Assessment of White Spot Lesions and In-Vivo Evaluation of the Effect of CPP-ACP on White Spot Lesions in Permanent Molars of Children

    PubMed Central

    Munjal, Deepti; Garg, Shalini; Dhindsa, Abhishek; Sidhu, Gagandeep Kaur

    2016-01-01

    Introduction As hindrance of remineralisation process occurs during orthodontic therapy resulting in decalcification of enamel because number of plaque retention sites increases due to banding and bonding of appliances to teeth. Aim The present analytic study was undertaken to assess the occurrence of white spot lesions in permanent molars of children with and without orthodontic therapy and to evaluate the effect of Casein PhosphoPeptide-Amorphous Calcium Phosphate (CPP-ACP) on white spot lesions in post-orthodontic patients in a given period of time. Materials and Methods The study comprised of examination of 679 first permanent molars which were examined to assess the occurrence of smooth surface white spot lesions in children of 8 to 16 years age group. Group I comprised subjects without any orthodontic treatment and Group II comprised of subjects who had undergone orthodontic therapy. The sample size was calculated using the epi-info6 computer package. Treatment group included 20 post-orthodontic patients examined with at least one white spot lesion within the enamel who received remineralizing cream (GC Tooth Mousse, Recaldent, GC Corporation.) i.e., CPP–ACP cream two times a day for 12 consecutive weeks. Computerized image analysis method was taken to evaluate white spot lesions. These frequency and percentages were compared with chi-square test. For comparison of numeric data, paired t-test was used. Results Of the total 278 (49.6%) first permanent molars showed occurrence of smooth surface white spot lesions out of 560 in Group I and 107 (89.9%) first permanent molars showed presence of white spot lesions out of 119 debanded first permanent molars of children examined in Group II. CPP-ACP therapy group showed reduction in severity of codes which was found to be highly significant after 12 weeks and eight weeks on gingival-third, p-value (<0.001) and significant after eight weeks and four weeks on middle-third according to ICDAS II criteria and

  16. Radiolabelling and positron emission tomography of PT70, a time-dependent inhibitor of InhA, the Mycobacterium tuberculosis enoyl-ACP reductase.

    PubMed

    Wang, Hui; Liu, Li; Lu, Yang; Pan, Pan; Hooker, Jacob M; Fowler, Joanna S; Tonge, Peter J

    2015-11-01

    PT70 is a diaryl ether inhibitor of InhA, the enoyl-ACP reductase in the Mycobacterium tuberculosis fatty acid biosynthesis pathway. It has a residence time of 24 min on the target, and also shows antibacterial activity in a mouse model of tuberculosis infection. Due to the interest in studying target tissue pharmacokinetics of PT70, we developed a method to radiolabel PT70 with carbon-11 and have studied its pharmacokinetics in mice and baboons using positron emission tomography. PMID:26227776

  17. A parallel row-based algorithm with error control for standard-cell replacement on a hypercube multiprocessor

    NASA Technical Reports Server (NTRS)

    Sargent, Jeff Scott

    1988-01-01

    A new row-based parallel algorithm for standard-cell placement targeted for execution on a hypercube multiprocessor is presented. Key features of this implementation include a dynamic simulated-annealing schedule, row-partitioning of the VLSI chip image, and two novel new approaches to controlling error in parallel cell-placement algorithms; Heuristic Cell-Coloring and Adaptive (Parallel Move) Sequence Control. Heuristic Cell-Coloring identifies sets of noninteracting cells that can be moved repeatedly, and in parallel, with no buildup of error in the placement cost. Adaptive Sequence Control allows multiple parallel cell moves to take place between global cell-position updates. This feedback mechanism is based on an error bound derived analytically from the traditional annealing move-acceptance profile. Placement results are presented for real industry circuits and the performance is summarized of an implementation on the Intel iPSC/2 Hypercube. The runtime of this algorithm is 5 to 16 times faster than a previous program developed for the Hypercube, while producing equivalent quality placement. An integrated place and route program for the Intel iPSC/2 Hypercube is currently being developed.

  18. Type III polyketide synthase beta-ketoacyl-ACP starter unit and ethylmalonyl-CoA extender unit selectivity discovered by Streptomyces coelicolor genome mining.

    PubMed

    Song, Lijiang; Barona-Gomez, Francisco; Corre, Christophe; Xiang, Longkuan; Udwary, Daniel W; Austin, Michael B; Noel, Joseph P; Moore, Bradley S; Challis, Gregory L

    2006-11-22

    Polyketide synthases (PKSs) are involved in the biosynthesis of many important natural products. In bacteria, type III PKSs typically catalyze iterative decarboxylation and condensation reactions of malonyl-CoA building blocks in the biosynthesis of polyhydroxyaromatic products. Here it is shown that Gcs, a type III PKS encoded by the sco7221 ORF of the bacterium Streptomyces coelicolor, is required for biosynthesis of the germicidin family of 3,6-dialkyl-4-hydroxypyran-2-one natural products. Evidence consistent with Gcs-catalyzed elongation of specific beta-ketoacyl-ACP products of the fatty acid synthase FabH with ethyl- or methylmalonyl-CoA in the biosynthesis of germicidins is presented. Selectivity for beta-ketoacyl-ACP starter units and ethylmalonyl-CoA as an extender unit is unprecedented for type III PKSs, suggesting these enzymes may be capable of utilizing a far wider range of starter and extender units for natural product assembly than believed until now. PMID:17105255

  19. Research in the Aloha system

    NASA Technical Reports Server (NTRS)

    Abramson, N.

    1974-01-01

    The Aloha system was studied and developed and extended to advanced forms of computer communications networks. Theoretical and simulation studies of Aloha type radio channels for use in packet switched communications networks were performed. Improved versions of the Aloha communications techniques and their extensions were tested experimentally. A packet radio repeater suitable for use with the Aloha system operational network was developed. General studies of the organization of multiprocessor systems centered on the development of the BCC 500 computer were concluded.

  20. Memory management and compiler support for rapid recovery from failures in computer systems

    NASA Technical Reports Server (NTRS)

    Fuchs, W. K.

    1991-01-01

    This paper describes recent developments in the use of memory management and compiler technology to support rapid recovery from failures in computer systems. The techniques described include cache coherence protocols for user transparent checkpointing in multiprocessor systems, compiler-based checkpoint placement, compiler-based code modification for multiple instruction retry, and forward recovery in distributed systems utilizing optimistic execution.

  1. Performance analysis of the Alliant FX/8 multiprocessor using statistical clustering

    NASA Technical Reports Server (NTRS)

    Dimpsey, Robert Tod

    1988-01-01

    Results for two distinct, real, scientific workloads executed on an Alliant FX/8 are discussed. A combination of user concurrency and system overhead measurements was taken for both workloads. Preliminary analysis shows that the first sampled workload is comprised of consistently high user concurrency, low system overhead, and little paging. The second sample has much less user concurrency, but significant paging and system overhead. Statistical cluster analysis is used to extract a state transition model to jointly characterize user concurrency and system overhead. A skewness factor is introduced and used to bring out the effects of unbalanced clustering when determining states with important transitions. The results from the models show that during the collection of the first sample, the system was operating in states of high user concurrency approximately 75 percent of the time. The second workload sample shows the system in high user concurrency states only 26 percent of the time. In addition, it is ascertained that high system overhead is usually accompanied by low user concurrency. The analysis also shows a high predictability of system behavior for both workloads.

  2. Event parallelism: Distributed memory parallel computing for high energy physics experiments

    SciTech Connect

    Nash, T.

    1989-05-01

    This paper describes the present and expected future development of distributed memory parallel computers for high energy physics experiments. It covers the use of event parallel microprocessor farms, particularly at Fermilab, including both ACP multiprocessors and farms of MicroVAXES. These systems have proven very cost effective in the past. A case is made for moving to the more open environment of UNIX and RISC processors. The 2nd Generation ACP Multiprocessor System, which is based on powerful RISC systems, is described. Given the promise of still more extraordinary increases in processor performance, a new emphasis on point to point, rather than bussed, communication will be required. Developments in this direction are described. 6 figs.

  3. Development and evaluation of a fault-tolerant multiprocessor (FTMP) computer

    NASA Technical Reports Server (NTRS)

    Smith, T. B., III; Lala, J. H.

    1986-01-01

    The design, development, and testing of FTMP hardware and software for use in advanced NASA vehicles are described in three previously published reports prepared for NASA. Consideration is given to the overall FTMP architecture; the system bus; the regional design and operation of processor, slave, clock-generation, and power systems; and the FTMP executive, facilities, acceptance-test/diagnostic, applications, and support softwar. Also included are a summary of test procedures and results and an executive summary characterizing the system, the reliability and availability models, and the overall performance.

  4. SpringNet: a network of multiprocessors for hard real-time. Final report

    SciTech Connect

    Stankovic, J.A.; Ramamritham, K.

    1988-10-01

    The Spring project has been very active in multiple areas of real-time computing. Significant results were developed in many aspects of real-time scheduling, in real-time operating system design, in real-time transactions, and in time-constrained communication protocols. We have also made progress in implementing a software (simulation) testbed, in developing a hardware operating system kernel testbed called SpringNet, and in implementing real-time transactions on a hardware testbed called CARAT. The authors also began a substantial research effort concerning dependable real-time systems, and provide a brief overview of the status and plans for the Spring project as a whole.

  5. Parallelizing a molecular dynamics algorithm on a multiprocessor workstation using OpenMP.

    PubMed

    Tarmyshov, Konstantin B; Müller-Plathe, Florian

    2005-01-01

    The atomistic molecular dynamics program YASP has been parallelized for shared-memory computer architectures. Parallelization was restricted to the most CPU-time-consuming parts: neighbor-list construction, calculation of nonbonded, angle and dihedral forces, and constraints. Most of the sequential FORTRAN code was kept; parallel constructs were inserted as compiler directives using the OpenMP standard. Only in the case of the neighbor list did the data structure have to be changed. The parallel code achieves a useful speedup over the sequential version for systems of several thousand atoms and above. On an IBM Regatta p690+, the throughput increases with the number of processors up to a maximum of 12-16 processors depending on the characteristics of the simulated systems. On dual-processor Xeon systems, the speedup is about 1.7. PMID:16309301

  6. AFN-1252 is a potent inhibitor of enoyl-ACP reductase from Burkholderia pseudomallei—Crystal structure, mode of action, and biological activity

    PubMed Central

    Narasimha Rao, Krishnamurthy; Lakshminarasimhan, Anirudha; Joseph, Sarah; Lekshmi, Swathi U; Lau, Ming-Seong; Takhi, Mohammed; Sreenivas, Kandepu; Nathan, Sheila; Yusof, Rohana; Abd Rahman, Noorsaadah; Ramachandra, Murali; Antony, Thomas; Subramanya, Hosahalli

    2015-01-01

    Melioidosis is a tropical bacterial infection caused by Burkholderia pseudomallei (B. pseudomallei; Bpm), a Gram-negative bacterium. Current therapeutic options are largely limited to trimethoprim-sulfamethoxazole and β-lactam drugs, and the treatment duration is about 4 months. Moreover, resistance has been reported to these drugs. Hence, there is a pressing need to develop new antibiotics for Melioidosis. Inhibition of enoyl-ACP reducatase (FabI), a key enzyme in the fatty acid biosynthesis pathway has shown significant promise for antibacterial drug development. FabI has been identified as the major enoyl-ACP reductase present in B. pseudomallei. In this study, we evaluated AFN-1252, a Staphylococcus aureus FabI inhibitor currently in clinical development, for its potential to bind to BpmFabI enzyme and inhibit B. pseudomallei bacterial growth. AFN-1252 stabilized BpmFabI and inhibited the enzyme activity with an IC50 of 9.6 nM. It showed good antibacterial activity against B. pseudomallei R15 strain, isolated from a melioidosis patient (MIC of 2.35 mg/L). X-ray structure of BpmFabI with AFN-1252 was determined at a resolution of 2.3 Å. Complex of BpmFabI with AFN-1252 formed a symmetrical tetrameric structure with one molecule of AFN-1252 bound to each monomeric subunit. The kinetic and thermal melting studies supported the finding that AFN-1252 can bind to BpmFabI independent of cofactor. The structural and mechanistic insights from these studies might help the rational design and development of new FabI inhibitors. PMID:25644789

  7. Cloning and functional expression of an acyl-ACP thioesterase FatB type from Diploknema (Madhuca) butyracea seeds in Escherichia coli.

    PubMed

    Jha, J K; Maiti, M K; Bhattacharjee, A; Basu, A; Sen, P C; Sen, S K

    2006-01-01

    A cDNA of fatty acyl-acyl carrier protein (ACP) thioesterase (Fat) from developing seed of Madhuca butyracea has been cloned. The deduced amino acid sequence of the cDNA corresponding to the mature polypeptide showed 30-40% and 60-75% identity to the reported FatA and FatB class of plant thioesterases, respectively. This gene, MbFatB, is present as a single copy in M. butyracea genome and the MbFatB protein was detected clearly in seed tissues of this plant but not in that of Indian mustard (Brassica juncea). Heterologous expression of the MbFatB gene driven by different promoters in E. coli wild type and fatty acid beta-oxidation mutant (fadD88) strains resulted production of the recombinant protein with various fusion tags either as biologically inactive (insoluble) or functionally active forms. Expression of functionally active recombinant MbFatB in E. coli affected bacterial growth and cell morphology as well as changed the fatty acid profiles of the membrane lipid and the culture supernatant. Alteration of the fatty acid composition was directed predominantly towards palmitate and to a lesser extent myristate and oleate due to acyl chain termination activity of plant thioesterase in bacteria. Thus, this new MbFatB gene isolated from a non-traditional oil-seed tree can be used in future for transgenic development of oil-seed Brassica, a widely cultivated crop that expresses predominantly oleoyl-ACP thioesterase (FatA) in its seed tissue and has high amount of unwanted erucic acid in edible oil in order to alter the fatty acid profile in a desirable way. PMID:17092734

  8. AFN-1252 is a potent inhibitor of enoyl-ACP reductase from Burkholderia pseudomallei--Crystal structure, mode of action, and biological activity.

    PubMed

    Rao, Krishnamurthy Narasimha; Lakshminarasimhan, Anirudha; Joseph, Sarah; Lekshmi, Swathi U; Lau, Ming-Seong; Takhi, Mohammed; Sreenivas, Kandepu; Nathan, Sheila; Yusof, Rohana; Abd Rahman, Noorsaadah; Ramachandra, Murali; Antony, Thomas; Subramanya, Hosahalli

    2015-05-01

    Melioidosis is a tropical bacterial infection caused by Burkholderia pseudomallei (B. pseudomallei; Bpm), a Gram-negative bacterium. Current therapeutic options are largely limited to trimethoprim-sulfamethoxazole and β-lactam drugs, and the treatment duration is about 4 months. Moreover, resistance has been reported to these drugs. Hence, there is a pressing need to develop new antibiotics for Melioidosis. Inhibition of enoyl-ACP reducatase (FabI), a key enzyme in the fatty acid biosynthesis pathway has shown significant promise for antibacterial drug development. FabI has been identified as the major enoyl-ACP reductase present in B. pseudomallei. In this study, we evaluated AFN-1252, a Staphylococcus aureus FabI inhibitor currently in clinical development, for its potential to bind to BpmFabI enzyme and inhibit B. pseudomallei bacterial growth. AFN-1252 stabilized BpmFabI and inhibited the enzyme activity with an IC50 of 9.6 nM. It showed good antibacterial activity against B. pseudomallei R15 strain, isolated from a melioidosis patient (MIC of 2.35 mg/L). X-ray structure of BpmFabI with AFN-1252 was determined at a resolution of 2.3 Å. Complex of BpmFabI with AFN-1252 formed a symmetrical tetrameric structure with one molecule of AFN-1252 bound to each monomeric subunit. The kinetic and thermal melting studies supported the finding that AFN-1252 can bind to BpmFabI independent of cofactor. The structural and mechanistic insights from these studies might help the rational design and development of new FabI inhibitors. PMID:25644789

  9. Insights from computational analysis of full-length β-ketoacyl-[ACP] synthase-II cDNA isolated from American and African oil palms

    PubMed Central

    Bhore, Subhash J.; Cha, Thye S.; Amelia, Kassim; Shah, Farida H.

    2014-01-01

    Background: Palm oil derived from fruits (mesocarp) of African oil palm (Elaeis guineensis Jacq. Tenera) and American oil palm (E. oleifera) is important for food industry. Due to high yield, Elaeis guineensis (Tenera) is cultivated on commercial scale, though its oil contains high (~54%) level of saturated fatty acids. The rate-limiting activity of beta-ketoacyl-[ACP] synthase-II (KAS-II) is considered mainly responsible for the high (44%) level of palmitic acid (C16:0) in the oil obtained from E. guineensis. Objective: The objective of this study was to annotate KAS-II cDNA isolated from American and African oil palms. Materials and Methods: The full-length E. oleifera KAS-II (EoKAS-II) cDNA clone was isolated using random method of gene isolation. Whereas, the E. guineensis KAS-II (EgTKAS-II) cDNA was isolated using reverse transcriptase polymerase chain reaction (RT-PCR) technique; and missing ends were obtained by employing 5’and 3’ RACE technique. Results: The results show that EoKAS-II and EgTKAS-II open reading frames (ORFs) are of 1689 and 1721 bp in length, respectively. Further analysis of the both EoKAS-II and EgTKAS-II predicted protein illustrates that they contains conserved domains for ‘KAS-I and II’, ‘elongating’ condensing enzymes, ‘condensing enzymes super-family’, and ‘3-oxoacyl-[ACP] synthase II’. The predicted protein sequences shows 95% similarity with each other. Consecutively, the three active sites (Cys, His, and His) were identified in both proteins. However, difference in positions of two active Histidine (His) residues was noticed. Conclusion: These insights may serve as the foundation in understanding the variable activity of KAS-II in American and African oil palms; and cDNA clones could be useful in the genetic engineering of oil palms. PMID:24678202

  10. Data acquisition and control system of the cosmic ray experiment kascade

    SciTech Connect

    Gils, H.J.

    1994-12-31

    The data acquisition and control system of the cosmic ray experiment KASCADE is based on a network of local front-end systems and a central multi-processor array, both using transputer processors. The hardware architecture, communication- and application-software is described.

  11. Design of a modular digital computer system, DRL 4. [for meeting future requirements of spaceborne computers

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The design is reported of an advanced modular computer system designated the Automatically Reconfigurable Modular Multiprocessor System, which anticipates requirements for higher computing capacity and reliability for future spaceborne computers. Subjects discussed include: an overview of the architecture, mission analysis, synchronous and nonsynchronous scheduling control, reliability, and data transmission.

  12. HEP - A semaphore-synchronized multiprocessor with central control. [Heterogeneous Element Processor

    NASA Technical Reports Server (NTRS)

    Gilliland, M. C.; Smith, B. J.; Calvert, W.

    1976-01-01

    The paper describes the design concept of the Heterogeneous Element Processor (HEP), a system tailored to the special needs of scientific simulation. In order to achieve high-speed computation required by simulation, HEP features a hierarchy of processes executing in parallel on a number of processors, with synchronization being largely accomplished by hardware. A full-empty-reserve scheme of synchronization is realized by zero-one-valued hardware semaphores. A typical system has, besides the control computer and the scheduler, an algebraic module, a memory module, a first-in first-out (FIFO) module, an integrator module, and an I/O module. The architecture of the scheduler and the algebraic module is examined in detail.

  13. Performance Modeling and Measurement of Parallelized Code for Distributed Shared Memory Multiprocessors

    NASA Technical Reports Server (NTRS)

    Waheed, Abdul; Yan, Jerry

    1998-01-01

    This paper presents a model to evaluate the performance and overhead of parallelizing sequential code using compiler directives for multiprocessing on distributed shared memory (DSM) systems. With increasing popularity of shared address space architectures, it is essential to understand their performance impact on programs that benefit from shared memory multiprocessing. We present a simple model to characterize the performance of programs that are parallelized using compiler directives for shared memory multiprocessing. We parallelized the sequential implementation of NAS benchmarks using native Fortran77 compiler directives for an Origin2000, which is a DSM system based on a cache-coherent Non Uniform Memory Access (ccNUMA) architecture. We report measurement based performance of these parallelized benchmarks from four perspectives: efficacy of parallelization process; scalability; parallelization overhead; and comparison with hand-parallelized and -optimized version of the same benchmarks. Our results indicate that sequential programs can conveniently be parallelized for DSM systems using compiler directives but realizing performance gains as predicted by the performance model depends primarily on minimizing architecture-specific data locality overhead.

  14. RTEMS SMP for LEON3/LEON4 Multi-Processor Devicies

    NASA Astrophysics Data System (ADS)

    Cederman, Daniel; Hellstrom, Daniel; Sherrill, Joel; Bloom, Gedare; Patte, Mathieu; Zulianello, Marco

    2014-08-01

    When multi-core processors are used in the space industry, they are mostly used in AMP configurations. The cost of increased complexity and difficulty in analyzing SMP systems has been deemed too high in comparison with the benefits of more processing power. A reason for this is the lack of easy to analyze operating systems capable of SMP configurations. In this paper we present an European Space Agency (ESA) activity aimed at bringing easily accessible SMP support to GR712RC and ESA's future Next Generation Microprocessor (NGMP). This will be achieved by extending the RTEMS operating system with SMP capabilities and by providing parallel programming models and related libraries to exploit the intrinsic parallelism of space applications. The work will be validated by porting the single-core Gaia Video Processing Unit space application used in ESA's Gaia satellite project to RTEMS SMP running on GR712RC and NGMP. The paper describes the ongoing effort and gives an overview of the challenges faced in extending a real-time OS to the SMP domain. The activity is funded by ESA under contract 4000108560/13/NL/JK. Gedare Bloom is supported in part by NSF CNS-0934725.

  15. A comparison of multiprocessor scheduling methods for iterative data flow architectures

    NASA Technical Reports Server (NTRS)

    Storch, Matthew

    1993-01-01

    A comparative study is made between the Algorithm to Architecture Mapping Model (ATAMM) and three other related multiprocessing models from the published literature. The primary focus of all four models is the non-preemptive scheduling of large-grain iterative data flow graphs as required in real-time systems, control applications, signal processing, and pipelined computations. Important characteristics of the models such as injection control, dynamic assignment, multiple node instantiations, static optimum unfolding, range-chart guided scheduling, and mathematical optimization are identified. The models from the literature are compared with the ATAMM for performance, scheduling methods, memory requirements, and complexity of scheduling and design procedures.

  16. Experience with a multiprocessor based on eight FPS 120B array processors

    SciTech Connect

    Bucher, I.Y.; Frederickson, P.O.; Moore, J.W.

    1981-01-01

    The rate of increase in the speed of monoprocessors is no longer keeping pace with the needs of the laboratory; accordingly, the use of parallel processors in large scientific computations is being investigated. As an initial experiment, a particle-in-cell plasma simulation was adapted to run on a star graph architecture consisting of a UNIVAC 1110 as hub, and up to eight Floating Point Systems AP120B array processors at the other vertices. Subdivision of tasks among processors and measured results are discussed.

  17. "Superluminal" FITS File Processing on Multiprocessors: Zero Time Endian Conversion Technique

    NASA Astrophysics Data System (ADS)

    Eguchi, Satoshi

    2013-05-01

    The FITS is the standard file format in astronomy, and it has been extended to meet the astronomical needs of the day. However, astronomical datasets have been inflating year by year. In the case of the ALMA telescope, a ~TB-scale four-dimensional data cube may be produced for one target. Considering that typical Internet bandwidth is tens of MB/s at most, the original data cubes in FITS format are hosted on a VO server, and the region which a user is interested in should be cut out and transferred to the user (Eguchi et al. 2012). The system will equip a very high-speed disk array to process a TB-scale data cube in 10 s, and disk I/O speed, endian conversion, and data processing speeds will be comparable. Hence, reducing the endian conversion time is one of issues to solve in our system. In this article, I introduce a technique named "just-in-time endian conversion", which delays the endian conversion for each pixel just before it is really needed, to sweep out the endian conversion time; by applying this method, the FITS processing speed increases 20% for single threading and 40% for multi-threading compared to CFITSIO. The speedup tightly relates to modern CPU architecture to improve the efficiency of instruction pipelines due to break of "causality", a programmed instruction code sequence.

  18. 3D Reconfigurable NoC Multiprocessor Imaging Interferometer for Space Climate

    NASA Astrophysics Data System (ADS)

    Dekoulis, George

    2016-07-01

    This paper describes the development of an imaging interferometer for long-term observations of solar activity related events. Heliospheric physics phenomena are responsible for causing irregularities to the ionospheric-magnetospheric plasmasphere. Distinct signatures of these events are captured and studied over long periods of time deducting crucial conclusions about the short-term Space Weather and in the long run about Space Climate. The new prototype features an eight-channel implementation. The available hardware resources permit a 256- channel configuration for accurate beam scanning of the Earth's plasmasphere. A dual-polarization scheme has been implemented for obtaining accurate measurements. The system is based on state-of-the-art three-dimensional reconfigurable logic and exhibits a performance increase in the range of 70% compared to similar instruments in operation. Special circuits allow measurements of the most intense heliospheric physics events to be fully captured and analyzed.

  19. Experimental demonstration of the optical multi-mesh hypercube: scaleable interconnection network for multiprocessors and multicomputers

    NASA Astrophysics Data System (ADS)

    Louri, Ahmed; Furlonge, Stephen; Neocleous, Costas

    1996-12-01

    A prototype of a novel topology for scaleable optical interconnection networks called the optical multi-mesh hypercube (OMMH) is experimentally demonstrated to as high as a 150-Mbit s data rate (2 7 1 nonreturn-to-zero pseudo-random data pattern) at a bit error rate of 10 13 link by the use of commercially available devices. OMMH is a scaleable network Appl. Opt. 33, 7558 (1994); J. Lightwave Technol. 12, 704 (1994) architecture that combines the positive features of the hypercube (small diameter, connectivity, symmetry, simple routing, and fault tolerance) and the mesh (constant node degree and size scaleability). The optical implementation method is divided into two levels: high-density local connections for the hypercube modules, and high-bit-rate, low-density, long connections for the mesh links connecting the hypercube modules. Free-space imaging systems utilizing vertical-cavity surface-emitting laser (VCSEL) arrays, lenslet arrays, space-invariant holographic techniques, and photodiode arrays are demonstrated for the local connections. Optobus fiber interconnects from Motorola are used for the long-distance connections. The OMMH was optimized to operate at the data rate of Motorola s Optobus (10-bit-wide, VCSEL-based bidirectional data interconnects at 150 Mbits s). Difficulties encountered included the varying fan-out efficiencies of the different orders of the hologram, misalignment sensitivity of the free-space links, low power (1 mW) of the individual VCSEL s, and noise.

  20. Parallel variable-band Choleski solvers for computational structural analysis applications on vector multiprocessor supercomputers

    NASA Technical Reports Server (NTRS)

    Poole, E. L.; Overman, A. L.

    1991-01-01

    A Choleski method used to solve linear systems of equations that arise in large scale structural analyses is described. The method uses a novel variable-band storage scheme and is structured to exploit fast local memory caches while minimizing data access delays between main memory and vector registers. Several parallel implementations of this method are described for the CRAY-2 and CRAY Y-MP computers demonstrating the use of microtasking and autotasking directives. A portable parallel language, FORCE, is also used for two different parallel implementations, demonstrating the use of CRAY macrotasking. Results are presented comparing the matrix factorization times for three representative structural analysis problems from runs made in both dedicated and multi-user modes on both the CRAY-2 and CRAY Y-MP computers. CPU and wall clock timings are given for the various parallel methods and are compared to single processor timings of the same algorithm. Computation rates over 1 GIGAFLOP (1 billion floating point operations per second) on a four processor CRAY-2 and over 2 GIGAFLOPS on an eight processor CRAY Y-MP are demonstrated as measured by wall clock time in a dedicated environment. Reduced wall clock times for the parallel methods relative to the single processor implementation of the same Choleski algorithm are also demonstrated for runs made in multi-user mode.

  1. A Self Consistent Multiprocessor Space Charge Algorithm that is Almost Embarrassingly Parallel

    SciTech Connect

    Edward Nissen, B. Erdelyi, S.L. Manikonda

    2012-07-01

    We present a space charge code that is self consistent, massively parallelizeable, and requires very little communication between computer nodes; making the calculation almost embarrassingly parallel. This method is implemented in the code COSY Infinity where the differential algebras used in this code are important to the algorithm's proper functioning. The method works by calculating the self consistent space charge distribution using the statistical moments of the test particles, and converting them into polynomial series coefficients. These coefficients are combined with differential algebraic integrals to form the potential, and electric fields. The result is a map which contains the effects of space charge. This method allows for massive parallelization since its statistics based solver doesn't require any binning of particles, and only requires a vector containing the partial sums of the statistical moments for the different nodes to be passed. All other calculations are done independently. The resulting maps can be used to analyze the system using normal form analysis, as well as advance particles in numbers and at speeds that were previously impossible.

  2. A pipelined IC architecture for radon transform computations in a multiprocessor array

    SciTech Connect

    Agi, I.; Hurst, P.J.; Current, K.W. . Dept. of Electrical Engineering and Computer Science)

    1990-05-25

    The amount of data generated by CT scanners is enormous, making the reconstruction operation slow, especially for 3-D and limited-data scans requiring iterative algorithms. The Radon transform and its inverse, commonly used for CT image reconstruction from projections, are computationally burdensome for today's single-processor computer architectures. If the processing times for the forward and inverse Radon transforms were comparatively small, a large set of new CT algorithms would become feasible, especially those for 3-D and iterative tomographic image reconstructions. In addition to image reconstruction, a fast Radon Transform Computer'' could be naturally applied in other areas of multidimensional signal processing including 2-D power spectrum estimation, modeling of human perception, Hough transforms, image representation, synthetic aperture radar processing, and others. A high speed processor for this operation is likely to motivate new algorithms for general multidimensional signal processing using the Radon transform. In the proposed workshop paper, we will first describe interpolation schemes useful in computation of the discrete Radon transform and backprojection and compare their errors and hardware complexities. We then will evaluate through statistical means the fixed-point number system required to accept and generate 12-bit input and output data with acceptable error using the linear interpolation scheme selected. These results set some of the requirements that must be met by our new VLSI chip architecture. Finally we will present a new unified architecture for a single-chip processor for computing both the forward Radon transform and backprojection at high data rates. 3 refs., 2 figs.

  3. A study of the Earth-Manna multithreaded system

    SciTech Connect

    Hum, H.H.J.; Maquelin, O.; Theobald, K.B.; Tian, Xinmin; Gao, G.R.; Hendren, L.J.

    1996-08-01

    Multithreaded architectures have been proposed for future multiprocessor systems. However, some open issues remain. Can multithreading be supported in a multiprocessor so that it can tolerate synchronization and communication latencies, with little intrusion on the performance of sequentially-executed code? How much does such support contribute to scalable performance when communication and synchronization demands are high? In this paper, we describe the design of EARTH, an architecture which addresses these issues. Each processor in EARTH has an off-the-shelf Execution Unit (EU) for executing threads, and an ASIC Synchronization Unit (SU) supporting dataflow-like thread synchronizations, scheduling, and remote requests. In preparation for an implementation of the SU, we have emulated a basic EARTH model on MANNA 2.0, an existing multiprocessor whose hardware configuration closely matches EARTH. This EARTH-MANNA testbed is fully functional, enabling us to experiment with large benchmarks with impressive speed. With this platform, we demonstrate that multithreading support can be efficiently implemented (with little emulation overhead) in a multiprocessor without a major impact on uniprocessor performance. Also, we measure how much basic multithreading support can help in tolerating increasing communication/synchronization demands.

  4. DAPHNE: a parallel multiprocessor data acquisition system for nuclear physics. [Data Acquisition by Parallel Histogramming and NEtworking

    SciTech Connect

    Welch, L.C.

    1984-01-01

    This paper describes a project to meet these data acquisition needs for a new accelerator, ATLAS, being built at Argonne National Laboratory. ATLAS is a heavy-ion linear superconducting accelerator providing beam energies up to 25 MeV/A with a relative spread in beam energy as good as .0001 and a time spread of less than 100 psec. Details about the hardware front end, command language, data structure, and the flow of event treatment are covered.

  5. A parallel numerical simulation for supersonic flows using zonal overlapped grids and local time steps for common and distributed memory multiprocessors

    SciTech Connect

    Patel, N.R.; Sturek, W.B.; Hiromoto, R.

    1989-01-01

    Parallel Navier-Stokes codes are developed to solve both two- dimensional and three-dimensional flow fields in and around ramjet and nose tip configurations. A multi-zone overlapped grid technique is used to extend an explicit finite-difference method to more complicated geometries. Parallel implementations are developed for execution on both distributed and common-memory multiprocessor architectures. For the steady-state solutions, the use of the local time-step method has the inherent advantage of reducing the communications overhead commonly incurred by parallel implementations. Computational results of the codes are given for a series of test problems. The parallel partitioning of computational zones is also discussed. 5 refs., 18 figs.

  6. Physiological function of mycobacterial mtFabD, an essential malonyl-CoA:AcpM transacylase of type 2 fatty acid synthase FASII, in yeast mct1Delta cells.

    PubMed

    Gurvitz, Aner

    2009-01-01

    Mycobacterium tuberculosis mtFabD is an essential malonyl-CoA:AcpM transacylase and is important for vital protein-protein interactions within type 2 fatty acid synthase FASII. mtFabD contacts KasA, KasB, FabH, InhA, and possibly also HadAB, HadBC, and FabG1/MabA. Disruption of mtFabD's interactions during FASII has been proposed for drug development. Here, the gene for a mitochondrially targeted mtFabD was ectopically expressed in Saccharomyces cerevisiae mct1Delta mutant cells lacking the corresponding mitochondrial malonyl-CoA transferase Mct1p, allowing the mutants to recover their abilities to respire on glycerol and synthesize lipoic acid. Hence, mtFabD could physiologically function in an environment lacking holo-AcpM or other native interaction partners. PMID:19859569

  7. Modulation of medium-chain fatty acid synthesis in Synechococcus sp. PCC 7002 by replacing FabH with a Chaetoceros Ketoacyl-ACP synthase

    DOE PAGESBeta

    Gu, Huiya; Jinkerson, Robert E.; Davies, Fiona K.; Sisson, Lyle A.; Schneider, Philip E.; Posewitz, Matthew C.

    2016-05-26

    The isolation or engineering of algal cells synthesizing high levels of medium-chain fatty acids (MCFAs) is attractive to mitigate the high clouding point of longer chain fatty acids in algal based biodiesel. To develop a more informed understanding of MCFA synthesis in photosynthetic microorganisms, we isolated several algae from Great Salt Lake and screened this collection for MCFA accumulation to identify strains naturally accumulating high levels of MCFA. A diatom, Chaetoceros sp. GSL56, accumulated particularly high levels of C14 (up to 40%), with the majority of C14 fatty acids allocated in triacylglycerols. Using whole cell transcriptome sequencing and de novomore » assembly, putative genes encoding fatty acid synthesis enzymes were identified. Enzymes from this Chaetoceros sp. were expressed in the cyanobacterium Synechococcus sp. PCC 7002 to validate gene function and to determine whether eukaryotic enzymes putatively lacking bacterial evolutionary control mechanisms could be used to improve MCFA production in this promising production strain. Replacement of the Synechococcus 7002 native FabH with a Chaetoceros ketoacyl-ACP synthase Ill increased MCFA synthesis up to fivefold. In conclusion, the level of increase is dependent on promoter strength and culturing conditions.« less

  8. Modulation of Medium-Chain Fatty Acid Synthesis in Synechococcus sp. PCC 7002 by Replacing FabH with a Chaetoceros Ketoacyl-ACP Synthase

    PubMed Central

    Gu, Huiya; Jinkerson, Robert E.; Davies, Fiona K.; Sisson, Lyle A.; Schneider, Philip E.; Posewitz, Matthew C.

    2016-01-01

    The isolation or engineering of algal cells synthesizing high levels of medium-chain fatty acids (MCFAs) is attractive to mitigate the high clouding point of longer chain fatty acids in algal based biodiesel. To develop a more informed understanding of MCFA synthesis in photosynthetic microorganisms, we isolated several algae from Great Salt Lake and screened this collection for MCFA accumulation to identify strains naturally accumulating high levels of MCFA. A diatom, Chaetoceros sp. GSL56, accumulated particularly high levels of C14 (up to 40%), with the majority of C14 fatty acids allocated in triacylglycerols. Using whole cell transcriptome sequencing and de novo assembly, putative genes encoding fatty acid synthesis enzymes were identified. Enzymes from this Chaetoceros sp. were expressed in the cyanobacterium Synechococcus sp. PCC 7002 to validate gene function and to determine whether eukaryotic enzymes putatively lacking bacterial evolutionary control mechanisms could be used to improve MCFA production in this promising production strain. Replacement of the Synechococcus 7002 native FabH with a Chaetoceros ketoacyl-ACP synthase III increased MCFA synthesis up to fivefold. The level of increase is dependent on promoter strength and culturing conditions. PMID:27303412

  9. Measurement of the Branching Fraction and Photon Energy Moments of B→Xsγ and ACP(B→Xs+dγ)

    NASA Astrophysics Data System (ADS)

    Aubert, B.; Barate, R.; Bona, M.; Boutigny, D.; Couderc, F.; Karyotakis, Y.; Lees, J. P.; Poireau, V.; Tisserand, V.; Zghiche, A.; Grauges, E.; Palano, A.; Chen, J. C.; Qi, N. D.; Rong, G.; Wang, P.; Zhu, Y. S.; Eigen, G.; Ofte, I.; Stugu, B.; Abrams, G. S.; Battaglia, M.; Brown, D. N.; Button-Shafer, J.; Cahn, R. N.; Charles, E.; Gill, M. S.; Groysman, Y.; Jacobsen, R. G.; Kadyk, J. A.; Kerth, L. T.; Kolomensky, Yu. G.; Kukartsev, G.; Lynch, G.; Mir, L. M.; Oddone, P. J.; Orimoto, T. J.; Pripstein, M.; Roe, N. A.; Ronan, M. T.; Wenzel, W. A.; Del Amo Sanchez, P.; Barrett, M.; Ford, K. E.; Harrison, T. J.; Hart, A. J.; Hawkes, C. M.; Morgan, S. E.; Watson, A. T.; Goetzen, K.; Held, T.; Koch, H.; Lewandowski, B.; Pelizaeus, M.; Peters, K.; Schroeder, T.; Steinke, M.; Boyd, J. T.; Burke, J. P.; Cottingham, W. N.; Walker, D.; Cuhadar-Donszelmann, T.; Fulsom, B. G.; Hearty, C.; Knecht, N. S.; Mattison, T. S.; McKenna, J. A.; Khan, A.; Kyberd, P.; Saleem, M.; Sherwood, D. J.; Teodorescu, L.; Blinov, V. E.; Bukin, A. D.; Druzhinin, V. P.; Golubev, V. B.; Onuchin, A. P.; Serednyakov, S. I.; Skovpen, Yu. I.; Solodov, E. P.; Todyshev, K. Yu; Best, D. S.; Bondioli, M.; Bruinsma, M.; Chao, M.; Curry, S.; Eschrich, I.; Kirkby, D.; Lankford, A. J.; Lund, P.; Mandelkern, M.; Mommsen, R. K.; Roethel, W.; Stoker, D. P.; Abachi, S.; Buchanan, C.; Foulkes, S. D.; Gary, J. W.; Long, O.; Shen, B. C.; Wang, K.; Zhang, L.; Hadavand, H. K.; Hill, E. J.; Paar, H. P.; Rahatlou, S.; Sharma, V.; Berryhill, J. W.; Campagnari, C.; Cunha, A.; Dahmes, B.; Hong, T. M.; Kovalskyi, D.; Richman, J. D.; Beck, T. W.; Eisner, A. M.; Flacco, C. J.; Heusch, C. A.; Kroseberg, J.; Lockman, W. S.; Nesom, G.; Schalk, T.; Schmitz, R. E.; Schumm, B. A.; Seiden, A.; Spradlin, P.; Williams, D. C.; Wilson, M. G.; Albert, J.; Chen, E.; Dvoretskii, A.; Fang, F.; Hitlin, D. G.; Narsky, I.; Piatenko, T.; Porter, F. C.; Ryd, A.; Samuel, A.; Mancinelli, G.; Meadows, B. T.; Sokoloff, M. D.; Blanc, F.; Bloom, P. C.; Chen, S.; Ford, W. T.; Hirschauer, J. F.; Kreisel, A.; Nauenberg, U.; Olivas, A.; Ruddick, W. O.; Smith, J. G.; Ulmer, K. A.; Wagner, S. R.; Zhang, J.; Chen, A.; Eckhart, E. A.; Soffer, A.; Toki, W. H.; Wilson, R. J.; Winklmeier, F.; Zeng, Q.; Altenburg, D. D.; Feltresi, E.; Hauke, A.; Jasper, H.; Petzold, A.; Spaan, B.; Brandt, T.; Klose, V.; Lacker, H. M.; Mader, W. F.; Nogowski, R.; Schubert, J.; Schubert, K. R.; Schwierz, R.; Sundermann, J. E.; Volk, A.; Bernard, D.; Bonneaud, G. R.; Grenier, P.; Latour, E.; Thiebaux, Ch.; Verderi, M.; Bard, D. J.; Clark, P. J.; Gradl, W.; Muheim, F.; Playfer, S.; Robertson, A. I.; Xie, Y.; Andreotti, M.; Bettoni, D.; Bozzi, C.; Calabrese, R.; Cibinetto, G.; Luppi, E.; Negrini, M.; Petrella, A.; Piemontese, L.; Prencipe, E.; Anulli, F.; Baldini-Ferroli, R.; Calcaterra, A.; de Sangro, R.; Finocchiaro, G.; Pacetti, S.; Patteri, P.; Peruzzi, I. M.; Piccolo, M.; Rama, M.; Zallo, A.; Buzzo, A.; Capra, R.; Contri, R.; Lo Vetere, M.; Macri, M. M.; Monge, M. R.; Passaggio, S.; Patrignani, C.; Robutti, E.; Santroni, A.; Tosi, S.; Brandenburg, G.; Chaisanguanthum, K. S.; Morii, M.; Wu, J.; Dubitzky, R. S.; Marks, J.; Schenk, S.; Uwer, U.; Bhimji, W.; Bowerman, D. A.; Dauncey, P. D.; Egede, U.; Flack, R. L.; Nash, J. A.; Nikolich, M. B.; Panduro Vazquez, W.; Chai, X.; Charles, M. J.; Mallik, U.; Meyer, N. T.; Ziegler, V.; Cochran, J.; Crawley, H. B.; Dong, L.; Eyges, V.; Meyer, W. T.; Prell, S.; Rosenberg, E. I.; Rubin, A. E.; Gritsan, A. V.; Fritsch, M.; Schott, G.; Arnaud, N.; Davier, M.; Grosdidier, G.; Höcker, A.; Le Diberder, F.; Lepeltier, V.; Lutz, A. M.; Oyanguren, A.; Pruvot, S.; Rodier, S.; Roudeau, P.; Schune, M. H.; Stocchi, A.; Wang, W. F.; Wormser, G.; Cheng, C. H.; Lange, D. J.; Wright, D. M.; Chavez, C. A.; Forster, I. J.; Fry, J. R.; Gabathuler, E.; Gamet, R.; George, K. A.; Hutchcroft, D. E.; Payne, D. J.; Schofield, K. C.; Touramanis, C.; Bevan, A. J.; di Lodovico, F.; Menges, W.; Sacco, R.; Cowan, G.; Flaecher, H. U.; Hopkins, D. A.; Jackson, P. S.; McMahon, T. R.; Ricciardi, S.; Salvatore, F.; Wren, A. C.; Brown, D. N.; Davis, C. L.; Allison, J.; Barlow, N. R.; Barlow, R. J.; Chia, Y. M.; Edgar, C. L.; Lafferty, G. D.; Naisbit, M. T.; Williams, J. C.; Yi, J. I.; Chen, C.; Hulsbergen, W. D.; Jawahery, A.; Lae, C. K.; Roberts, D. A.; Simi, G.; Blaylock, G.; Dallapiccola, C.; Hertzbach, S. S.; Li, X.; Moore, T. B.; Saremi, S.; Staengle, H.; Cowan, R.; Sciolla, G.; Sekula, S. J.; Spitznagel, M.; Taylor, F.; Yamamoto, R. K.; Kim, H.; Patel, P. M.; Robertson, S. H.; Lazzaro, A.; Lombardo, V.; Palombo, F.; Bauer, J. M.; Cremaldi, L.; Eschenburg, V.; Godang, R.; Kroeger, R.; Sanders, D. A.; Summers, D. J.; Zhao, H. W.; Brunet, S.; Côté, D.; Taras, P.; Viaud, F. B.; Nicholson, H.; Cavallo, N.; de Nardo, G.; Fabozzi, F.; Gatto, C.; Lista, L.; Monorchio, D.; Paolucci, P.; Piccolo, D.; Sciacca, C.; Baak, M.; Raven, G.; Snoek, H. L.; Jessop, C. P.; Losecco, J. M.; Allmendinger, T.; Benelli, G.; Gan, K. K.; Honscheid, K.; Hufnagel, D.; Jackson, P. D.; Kagan, H.; Kass, R.; Rahimi, A. M.; Ter-Antonyan, R.; Wong, Q. K.; Blount, N. L.; Brau, J.; Frey, R.; Igonkina, O.; Lu, M.; Potter, C. T.; Rahmat, R.; Sinev, N. B.; Strom, D.; Strube, J.; Torrence, E.; Galeazzi, F.; Gaz, A.; Margoni, M.; Morandin, M.; Pompili, A.; Posocco, M.; Rotondo, M.; Simonetto, F.; Stroili, R.; Voci, C.; Benayoun, M.; Chauveau, J.; David, P.; Del Buono, L.; de La Vaissière, Ch.; Hamon, O.; Hartfiel, B. L.; John, M. J. J.; Malclès, J.; Ocariz, J.; Roos, L.; Therin, G.; Behera, P. K.; Gladney, L.; Panetta, J.; Biasini, M.; Covarelli, R.; Angelini, C.; Batignani, G.; Bettarini, S.; Bucci, F.; Calderini, G.; Carpinelli, M.; Cenci, R.; Forti, F.; Giorgi, M. A.; Lusiani, A.; Marchiori, G.; Mazur, M. A.; Morganti, M.; Neri, N.; Paoloni, E.; Rizzo, G.; Walsh, J. J.; Haire, M.; Judd, D.; Wagoner, D. E.; Biesiada, J.; Danielson, N.; Elmer, P.; Lau, Y. P.; Lu, C.; Olsen, J.; Smith, A. J. S.; Telnov, A. V.; Bellini, F.; Cavoto, G.; D'Orazio, A.; Del Re, D.; di Marco, E.; Faccini, R.; Ferrarotto, F.; Ferroni, F.; Gaspero, M.; Li Gioi, L.; Mazzoni, M. A.; Morganti, S.; Piredda, G.; Polci, F.; Safai Tehrani, F.; Voena, C.; Ebert, M.; Schröder, H.; Waldi, R.; Adye, T.; de Groot, N.; Franek, B.; Olaiya, E. O.; Wilson, F. F.; Aleksan, R.; Emery, S.; Gaidot, A.; Ganzhur, S. F.; Hamel de Monchenault, G.; Kozanecki, W.; Legendre, M.; Vasseur, G.; Yèche, Ch.; Zito, M.; Chen, X. R.; Liu, H.; Park, W.; Purohit, M. V.; Wilson, J. R.; Allen, M. T.; Aston, D.; Bartoldus, R.; Bechtle, P.; Berger, N.; Claus, R.; Coleman, J. P.; Convery, M. R.; Cristinziani, M.; Dingfelder, J. C.; Dorfan, J.; Dubois-Felsmann, G. P.; Dujmic, D.; Dunwoodie, W.; Field, R. C.; Glanzman, T.; Gowdy, S. J.; Graham, M. T.; Halyo, V.; Hast, C.; Hryn'Ova, T.; Innes, W. R.; Kelsey, M. H.; Kim, P.; Leith, D. W. G. S.; Li, S.; Libby, J.; Luitz, S.; Luth, V.; Lynch, H. L.; Macfarlane, D. B.; Marsiske, H.; Messner, R.; Muller, D. R.; O'Grady, C. P.; Ozcan, V. E.; Perazzo, A.; Perl, M.; Pulliam, T.; Ratcliff, B. N.; Roodman, A.; Salnikov, A. A.; Schindler, R. H.; Schwiening, J.; Snyder, A.; Stelzer, J.; Su, D.; Sullivan, M. K.; Suzuki, K.; Swain, S. K.; Thompson, J. M.; Tinslay, J. S.; Va'Vra, J.; van Bakel, N.; Weaver, M.; Weinstein, A. J. R.; Wisniewski, W. J.; Wittgen, M.; Wright, D. H.; Yarritu, A. K.; Yi, K.; Young, C. C.; Burchat, P. R.; Edwards, A. J.; Majewski, S. A.; Petersen, B. A.; Roat, C.; Wilden, L.; Ahmed, S.; Alam, M. S.; Bula, R.; Ernst, J. A.; Jain, V.; Pan, B.; Saeed, M. A.; Wappler, F. R.; Zain, S. B.; Bugg, W.; Krishnamurthy, M.; Spanier, S. M.; Eckmann, R.; Ritchie, J. L.; Satpathy, A.; Schilling, C. J.; Schwitters, R. F.; Izen, J. M.; Lou, X. C.; Ye, S.; Bianchi, F.; Gallo, F.; Gamba, D.; Bomben, M.; Bosisio, L.; Cartaro, C.; Cossutti, F.; Della Ricca, G.; Dittongo, S.; Lanceri, L.; Vitale, L.; Azzolini, V.; Martinez-Vidal, F.; Banerjee, Sw.; Bhuyan, B.; Brown, C. M.; Fortin, D.; Hamano, K.; Kowalewski, R.; Nugent, I. M.; Roney, J. M.; Sobie, R. J.; Back, J. J.; Harrison, P. F.; Latham, T. E.; Mohanty, G. B.; Pappagallo, M.; Band, H. R.; Chen, X.; Cheng, B.; Dasu, S.; Datta, M.; Flood, K. T.; Hollar, J. J.; Kutter, P. E.; Mellado, B.; Mihalyi, A.; Pan, Y.; Pierini, M.; Prepost, R.; Wu, S. L.; Yu, Z.; Neal, H.

    2006-10-01

    The photon spectrum in B→Xsγ decay, where Xs is any strange hadronic state, is studied using a data sample of 88.5×106 e+e-→Υ(4S)→BB¯ decays collected by the BABAR experiment at the Stanford Linear Accelerator Center. The partial branching fraction, ΔB(B→Xsγ)=(3.67±0.29(stat)±0.34(syst)±0.29(model))×10-4, the first moment ⟨Eγ⟩=2.288±0.025±0.017±0.015GeV, and the second moment ⟨Eγ2⟩=0.0328±0.0040±0.0023±0.0036GeV2 are measured for the photon energy range 1.9GeV1.6GeV. In addition, the direct CP asymmetry ACP(B→Xs+dγ) is measured to be -0.110±0.115(stat)±0.017(syst).

  10. Modulation of Medium-Chain Fatty Acid Synthesis in Synechococcus sp. PCC 7002 by Replacing FabH with a Chaetoceros Ketoacyl-ACP Synthase.

    PubMed

    Gu, Huiya; Jinkerson, Robert E; Davies, Fiona K; Sisson, Lyle A; Schneider, Philip E; Posewitz, Matthew C

    2016-01-01

    The isolation or engineering of algal cells synthesizing high levels of medium-chain fatty acids (MCFAs) is attractive to mitigate the high clouding point of longer chain fatty acids in algal based biodiesel. To develop a more informed understanding of MCFA synthesis in photosynthetic microorganisms, we isolated several algae from Great Salt Lake and screened this collection for MCFA accumulation to identify strains naturally accumulating high levels of MCFA. A diatom, Chaetoceros sp. GSL56, accumulated particularly high levels of C14 (up to 40%), with the majority of C14 fatty acids allocated in triacylglycerols. Using whole cell transcriptome sequencing and de novo assembly, putative genes encoding fatty acid synthesis enzymes were identified. Enzymes from this Chaetoceros sp. were expressed in the cyanobacterium Synechococcus sp. PCC 7002 to validate gene function and to determine whether eukaryotic enzymes putatively lacking bacterial evolutionary control mechanisms could be used to improve MCFA production in this promising production strain. Replacement of the Synechococcus 7002 native FabH with a Chaetoceros ketoacyl-ACP synthase III increased MCFA synthesis up to fivefold. The level of increase is dependent on promoter strength and culturing conditions. PMID:27303412

  11. Elucidating the structural basis of diphenyl ether derivatives as highly potent enoyl-ACP reductase inhibitors through molecular dynamics simulations and 3D-QSAR study.

    PubMed

    Kamsri, Pharit; Punkvang, Auradee; Saparpakorn, Patchareenart; Hannongbua, Supa; Irle, Stephan; Pungpo, Pornpan

    2014-07-01

    Diphenyl ether derivatives are good candidates for anti-tuberculosis agents that display a promising potency for inhibition of InhA, an essential enoyl-acyl carrier protein (ACP) reductase involved in fatty acid biosynthesis pathways in Mycobacterium tuberculosis. In this work, key structural features for the inhibition were identified by 3D-QSAR CoMSIA models, constructed based on available experimental binding properties of diphenyl ether inhibitors, and a set of four representative compounds was subjected to MD simulations of inhibitor-InhA complexes for the calculation of binding free energies. The results show that bulky groups are required for the R1 substituent on the phenyl A ring of the inhibitors to favor a hydrophobic pocket formed by residues Phe149, Met155, Pro156, Ala157, Tyr158, Pro193, Met199, Val203, Leu207, Ile215, and Leu218. Small substituents with a hydrophilic property are required at the R3 and R4 positions of the inhibitor phenyl B rings to form hydrogen bonds with the backbones of Gly96 and Met98, respectively. For the R2 substituent, small substituents with simultaneous hydrophilic or hydrophobic properties are required to favor the interaction with the pyrophosphate moiety of NAD(+) and the methyl side chain of Ala198, respectively. The reported data provide structural guidance for the design of new and potent diphenyl ether-based inhibitors with high inhibitory activities against M. tuberculosis InhA. PMID:24935113

  12. Distributed Optimization System

    DOEpatents

    Hurtado, John E.; Dohrmann, Clark R.; Robinett, III, Rush D.

    2004-11-30

    A search system and method for controlling multiple agents to optimize an objective using distributed sensing and cooperative control. The search agent can be one or more physical agents, such as a robot, and can be software agents for searching cyberspace. The objective can be: chemical sources, temperature sources, radiation sources, light sources, evaders, trespassers, explosive sources, time dependent sources, time independent sources, function surfaces, maximization points, minimization points, and optimal control of a system such as a communication system, an economy, a crane, and a multi-processor computer.

  13. New computing systems and their impact on computational mechanics

    NASA Technical Reports Server (NTRS)

    Noor, Ahmed K.

    1989-01-01

    Recent advances in computer technology that are likely to impact computational mechanics are reviewed. The technical needs for computational mechanics technology are outlined. The major features of new and projected computing systems, including supersystems, parallel processing machines, special-purpose computing hardware, and small systems are described. Advances in programming environments, numerical algorithms, and computational strategies for new computing systems are reviewed, and a novel partitioning strategy is outlined for maximizing the degree of parallelism on multiprocessor computers with a shared memory.

  14. Cloning and functional expression of a cDNA encoding stearoyl-ACP Δ9-desaturase from the endosperm of coconut (Cocos nucifera L.).

    PubMed

    Gao, Lingchao; Sun, Ruhao; Liang, Yuanxue; Zhang, Mengdan; Zheng, Yusheng; Li, Dongdong

    2014-10-01

    Coconut (Cocos nucifera L.) is an economically tropical fruit tree with special fatty acid compositions. The stearoyl-acyl carrier protein (ACP) desaturase (SAD) plays a key role in the properties of the majority of cellular glycerolipids. In this paper, a full-length cDNA of a stearoyl-acyl carrier protein desaturase, designated CocoFAD, was isolated from cDNA library prepared from the endosperm of coconut (C. nucifera L.). An 1176 bp cDNA from overlapped PCR products containing ORF encoding a 391-amino acid (aa) protein was obtained. The coded protein was virtually identical and shared the homology to other Δ9-desaturase plant sequences (greater than 80% as similarity to that of Elaeis guineensis Jacq). The real-time fluorescent quantitative PCR result indicated that the yield of CocoFAD was the highest in the endosperm of 8-month-old coconut and leaf, and the yield was reduced to 50% of the highest level in the endosperm of 15-month-old coconut. The coding region showed heterologous expression in strain INVSc1 of yeast (Saccharomyces cerevisiae). GC-MS analysis showed that the levels of palmitoleic acid (16:1) and oleic acid (18:1) were improved significantly; meanwhile stearic acid (18:0) was reduced. These results indicated that the plastidial Δ9 desaturase from the endosperm of coconut was involved in the biosynthesis of hexadecenoic acid and octadecenoic acid, which was similar with other plants. These results may be valuable for understanding the mechanism of fatty acid metabolism and the genetic improvement of CocoFAD gene in palm plants in the future. PMID:25038276

  15. Molecular basis for the inhibition of β-hydroxyacyl-ACP dehydratase HadAB complex from Mycobacterium tuberculosis by flavonoid inhibitors.

    PubMed

    Dong, Yu; Qiu, Xiaodi; Shaw, Neil; Xu, Yueyang; Sun, Yuna; Li, Xuemei; Li, Jun; Rao, Zihe

    2015-07-01

    Dehydration is one of the key steps in the biosynthesis of mycolic acids and is vital to the growth of Mycobacterium tuberculosis (Mtb). Consequently, stalling dehydration cures tuberculosis (TB). Clinically used anti-TB drugs like thiacetazone (TAC) and isoxyl (ISO) as well as flavonoids inhibit the enzyme activity of the β-hydroxyacyl-ACP dehydratase HadAB complex. How this inhibition is exerted, has remained an enigma for years. Here, we describe the first crystal structures of the MtbHadAB complex bound with flavonoid inhibitor butein, 2',4,4'-trihydroxychalcone or fisetin. Despite sharing no sequence identity from Blast, HadA and HadB adopt a very similar hotdog fold. HadA forms a tight dimer with HadB in which the proteins are sitting side-by-side, but are oriented anti-parallel. While HadB contributes the catalytically critical His-Asp dyad, HadA binds the fatty acid substrate in a long channel. The atypical double hotdog fold with a single active site formed by MtbHadAB gives rise to a long, narrow cavity that vertically traverses the fatty acid binding channel. At the base of this cavity lies Cys61, which upon mutation to Ser confers drug-resistance in TB patients. We show that inhibitors bind in this cavity and protrude into the substrate binding channel. Thus, inhibitors of MtbHadAB exert their effect by occluding substrate from the active site. The unveiling of this mechanism of inhibition paves the way for accelerating development of next generation of anti-TB drugs. PMID:26081470

  16. Technology forecast and applications for autonomous, intelligent systems. [for space station, shuttle, and interplanetary missions

    NASA Technical Reports Server (NTRS)

    Lum, Henry, Jr.; Heer, Ewald

    1988-01-01

    Significant research products which have emerged from the core program of NASA's Office of Aeronautics and Space Technology (OAST) are discussed. The Space Station Thermal Control System, the Space Shuttle Integrated Communications Officer Station, the Launch Processing System, the Expert Scheduling System for Pioneer Venus Spacecraft, a Bayesian classification system, and a spaceborne multiprocessor system are included. The technology trends which led to these results are discussed and future developments in technology are forecasted.

  17. 4GL ward management system.

    PubMed Central

    Brandejs, J. F.

    1991-01-01

    After many years of extensive research of computerized information systems for nursing, inpatient care, clinics and HMOs, laboratories, diagnostic imaging, pharmacy and other services, an integrated Ward Patient Management system was developed. A mature, relational data base management system (RDBMS) ORACLE was selected as the design tool. The system is running under VMS, DOS and UNIX operating systems and ORACLE version 6 on nearly all computer platforms, although multiprocessors are preferred. A host of potentials and pitfalls is associated with the implementation of this new approach to Patient Management. PMID:1807662

  18. ACP Best Practice No 164

    PubMed Central

    Parsons, M; Start, R

    2001-01-01

    Much important information can be obtained at necropsy by the pathological examination of the eye and its adnexal structures in adults and children. This information may be related to the cause of death (for example, violent shaking trauma in physical child abuse), or may pertain to disease processes affecting the eye, the orbit, and surrounding structures outside the orbit. This article reviews the technical methods used to remove the following: the vitreous (for example, for biochemistry); the eye itself (anterior approach); the eye and orbital contents (posterior approach); the eye, orbit and orbital walls; and the eye, orbital walls, and surrounding structures. The removal of the eye and adnexal ocular structures must be recognised as a "culturally sensitive" issue, which must be approached cautiously. It should only be undertaken for sound scientific reasons, with the fully informed consent of the relatives and/or the coroner (or equivalent authority), and with properly agreed procedures for the eventual retention or disposal of the ocular tissues. For this reason, this article reviews not only the scientific indications and methods for the removal of such tissues, but also the legal and ethical issues that must underpin this pathology "best practice". Key Words: necropsy • ophthalamic pathology • enucleation PMID:11376013

  19. ACP Best Practice No 167

    PubMed Central

    Graham, J; Galloway, A

    2001-01-01

    Urinary tract infection is common, and it is not surprising that urine specimens make up a large proportion of those samples submitted to the routine diagnostic laboratory. Many of these specimens will show no evidence of infection and several methods can be used to screen out negative samples. Those that grow bacteria need to be carefully assessed to quantify the degree of bacteriuria and hence clinical relevance. To influence treatment, a final report should be produced within 24 hours of specimen receipt, with turnaround times continuously monitored. Much work needs to be done to determine the cost effectiveness involved in processing urine specimens and the evidence base for the final report provided. Key Words: laboratory diagnosis • urinary tract infection PMID:11729209

  20. Modeling of Spacecraft Advanced Chemical Propulsion Systems

    NASA Technical Reports Server (NTRS)

    Benfield, Michael P. J.; Belcher, Jeremy A.

    2004-01-01

    This paper outlines the development of the Advanced Chemical Propulsion System (ACPS) model for Earth and Space Storable propellants. This model was developed by the System Technology Operation of SAIC-Huntsville for the NASA MSFC In-Space Propulsion Project Office. Each subsystem of the model is described. Selected model results will also be shown to demonstrate the model's ability to evaluate technology changes in chemical propulsion systems.

  1. In-Space Chemical Propulsion System Model

    NASA Technical Reports Server (NTRS)

    Byers, David C.; Woodcock, Gordon; Benfield, Michael P. J.

    2004-01-01

    Multiple, new technologies for chemical systems are becoming available and include high temperature rockets, very light propellant tanks and structures, new bipropellant and monopropellant options, lower mass propellant control components, and zero boil off subsystems. Such technologies offer promise of increasing the performance of in-space chemical propulsion for energetic space missions. A mass model for pressure-fed, Earth and space-storable, advanced chemical propulsion systems (ACPS) was developed in support of the NASA MSFC In-Space Propulsion Program. Data from flight systems and studies defined baseline system architectures and subsystems and analyses were formulated for parametric scaling relationships for all ACPS subsystem. The paper will first provide summary descriptions of the approaches used for the systems and the subsystems and then present selected analyses to illustrate use of the model for missions with characteristics of current interest.

  2. In-Space Chemical Propulsion System Model

    NASA Technical Reports Server (NTRS)

    Byers, David C.; Woodcock, Gordon; Benfield, M. P. J.

    2004-01-01

    Multiple, new technologies for chemical systems are becoming available and include high temperature rockets, very light propellant tanks and structures, new bipropellant and monopropellant options, lower mass propellant control components, and zero boil off subsystems. Such technologies offer promise of increasing the performance of in-space chemical propulsion for energetic space missions. A mass model for pressure-fed, Earth and space-storable, advanced chemical propulsion systems (ACPS) was developed in support of the NASA MSFC In-Space Propulsion Program. Data from flight systems and studies defined baseline system architectures and subsystems and analyses were formulated for parametric scaling relationships for all ACPS subsystems. The paper will first provide summary descriptions of the approaches used for the systems and the subsystems and then present selected analyses to illustrate use of the model for missions with characteristics of current interest.

  3. Three-dimensional (3D) structure prediction of the American and African oil-palms β-ketoacyl-[ACP] synthase-II protein by comparative modelling

    PubMed Central

    Wang, Edina; Chinni, Suresh; Bhore, Subhash Janardhan

    2014-01-01

    Background: The fatty-acid profile of the vegetable oils determines its properties and nutritional value. Palm-oil obtained from the African oil-palm [Elaeis guineensis Jacq. (Tenera)] contains 44% palmitic acid (C16:0), but, palm-oil obtained from the American oilpalm [Elaeis oleifera] contains only 25% C16:0. In part, the b-ketoacyl-[ACP] synthase II (KASII) [EC: 2.3.1.179] protein is responsible for the high level of C16:0 in palm-oil derived from the African oil-palm. To understand more about E. guineensis KASII (EgKASII) and E. oleifera KASII (EoKASII) proteins, it is essential to know its structures. Hence, this study was undertaken. Objective: The objective of this study was to predict three-dimensional (3D) structure of EgKASII and EoKASII proteins using molecular modelling tools. Materials and Methods: The amino-acid sequences for KASII proteins were retrieved from the protein database of National Center for Biotechnology Information (NCBI), USA. The 3D structures were predicted for both proteins using homology modelling and ab-initio technique approach of protein structure prediction. The molecular dynamics (MD) simulation was performed to refine the predicted structures. The predicted structure models were evaluated and root mean square deviation (RMSD) and root mean square fluctuation (RMSF) values were calculated. Results: The homology modelling showed that EgKASII and EoKASII proteins are 78% and 74% similar with Streptococcus pneumonia KASII and Brucella melitensis KASII, respectively. The EgKASII and EoKASII structures predicted by using ab-initio technique approach shows 6% and 9% deviation to its structures predicted by homology modelling, respectively. The structure refinement and validation confirmed that the predicted structures are accurate. Conclusion: The 3D structures for EgKASII and EoKASII proteins were predicted. However, further research is essential to understand the interaction of EgKASII and EoKASII proteins with its substrates. PMID

  4. Distributed optimization system and method

    DOEpatents

    Hurtado, John E.; Dohrmann, Clark R.; Robinett, III, Rush D.

    2003-06-10

    A search system and method for controlling multiple agents to optimize an objective using distributed sensing and cooperative control. The search agent can be one or more physical agents, such as a robot, and can be software agents for searching cyberspace. The objective can be: chemical sources, temperature sources, radiation sources, light sources, evaders, trespassers, explosive sources, time dependent sources, time independent sources, function surfaces, maximization points, minimization points, and optimal control of a system such as a communication system, an economy, a crane, and a multi-processor computer.

  5. Distributed RTEMS Prototyping for Hard Real-Time Systems

    NASA Astrophysics Data System (ADS)

    Bossard, F.; Jouanneau, S.

    2009-05-01

    This paper presents a software prototyping to accommodate RTEMS to any embedded multiprocessor architecture. It outlines the development effort to move this free kernel to a distributed system. The concern of such an approach is to uncouple application software from underlying hardware including network. A real test platform consists of two ERC32 boards linked through an Ethernet network. RTEMS validation is achieved thanks to functional tests and a hard real-time application.

  6. A SEM and non-contact surface white light profilometry in vivo study of the effect of a crème containing CPP-ACP and fluoride on young etched enamel.

    PubMed

    Baroni, Chiara; Marchionni, Silvia; Bazzocchi, Maria Giulia; Cadenaro, Milena; Nucci, Cesare; Manton, David J

    2014-01-01

    The aim of this in vivo study was to evaluate the short and a longer term effect on enamel of the application of a crème containing 10% CPP-ACP and 900 ppm fluoride, in orthodontically planned, high caries-risk patients. Epoxy resin replicas of upper lateral incisors were obtained from polyvinyl siloxane (PVS) impressions, before and after etching. The right incisors were left untreated in order to control saliva remineralizing potential. The upper left surfaces were coated with a pea-size amount of the crème. Replicas were obtained at 3 weeks and 6 months and analyzed by SEM and non-contact surface white light profilometry. In the treated sample the profilometric roughness parameters at 3 weeks were statistically significantly lower than the control group values (p < 0.05). At 3 weeks SEM images of the enamel surface showed fewer irregularities. After 6 months, differences between test and control groups were not present on SEM images and profilometric values. CPP-ACP and fluoride crème had positive in vivo effects on enamel surfaces. Significant differences in surface roughness existed after a 3-week period of crème use. PMID:23843169

  7. Optimum spaceborne computer system design by simulation

    NASA Technical Reports Server (NTRS)

    Williams, T.; Kerner, H.; Weatherbee, J. E.; Taylor, D. S.; Hodges, B.

    1973-01-01

    A deterministic simulator is described which models the Automatically Reconfigurable Modular Multiprocessor System (ARMMS), a candidate computer system for future manned and unmanned space missions. Its use as a tool to study and determine the minimum computer system configuration necessary to satisfy the on-board computational requirements of a typical mission is presented. The paper describes how the computer system configuration is determined in order to satisfy the data processing demand of the various shuttle booster subsytems. The configuration which is developed as a result of studies with the simulator is optimal with respect to the efficient use of computer system resources.

  8. Optimum spaceborne computer system design by simulation

    NASA Technical Reports Server (NTRS)

    Williams, T.; Weatherbee, J. E.; Taylor, D. S.

    1972-01-01

    A deterministic digital simulation model is described which models the Automatically Reconfigurable Modular Multiprocessor System (ARMMS), a candidate computer system for future manned and unmanned space missions. Use of the model as a tool in configuring a minimum computer system for a typical mission is demonstrated. The configuration which is developed as a result of studies with the simulator is optimal with respect to the efficient use of computer system resources, i.e., the configuration derived is a minimal one. Other considerations such as increased reliability through the use of standby spares would be taken into account in the definition of a practical system for a given mission.

  9. Digital signal processor and programming system for parallel signal processing

    SciTech Connect

    Van den Bout, D.E.

    1987-01-01

    This thesis describes an integrated assault upon the problem of designing high-throughput, low-cost digital signal-processing systems. The dual prongs of this assault consist of: (1) the design of a digital signal processor (DSP) which efficiently executes signal-processing algorithms in either a uniprocessor or multiprocessor configuration, (2) the PaLS programming system which accepts an arbitrary algorithm, partitions it across a group of DSPs, synthesizes an optimal communication link topology for the DSPs, and schedules the partitioned algorithm upon the DSPs. The results of applying a new quasi-dynamic analysis technique to a set of high-level signal-processing algorithms were used to determine the uniprocessor features of the DSP design. For multiprocessing applications, the DSP contains an interprocessor communications port (IPC) which supports simple, flexible, dataflow communications while allowing the total communication bandwidth to be incrementally allocated to achieve the best link utilization. The net result is a DSP with a simple architecture that is easy to program for both uniprocessor and multi-processor modes of operation. The PaLS programming system simplifies the task of parallelizing an algorithm for execution upon a multiprocessor built with the DSP.

  10. Using parallel banded linear system solvers in generalized eigenvalue problems

    NASA Technical Reports Server (NTRS)

    Zhang, Hong; Moss, William F.

    1993-01-01

    Subspace iteration is a reliable and cost effective method for solving positive definite banded symmetric generalized eigenproblems, especially in the case of large scale problems. This paper discusses an algorithm that makes use of two parallel banded solvers in subspace iteration. A shift is introduced to decompose the banded linear systems into relatively independent subsystems and to accelerate the iterations. With this shift, an eigenproblem is mapped efficiently into the memories of a multiprocessor and a high speed-up is obtained for parallel implementations. An optimal shift is a shift that balances total computation and communication costs. Under certain conditions, we show how to estimate an optimal shift analytically using the decay rate for the inverse of a banded matrix, and how to improve this estimate. Computational results on iPSC/2 and iPSC/860 multiprocessors are presented.

  11. Impact of delays in parallel I/O system: An empirical study

    SciTech Connect

    Venugopal, C.R.; Rao, S.S.S.P.

    1996-12-31

    Performance of I/O intensive applications on a multiprocessor system depends mostly on the variety of disk access delays encountered in the I/O system. Over the years, the improvement in disk performance has taken place slower than corresponding increase in processor speeds. It is therefore necessary to model I/O delays and evaluate performance benefits of moving an application to a better multiprocessor system. In this work, we perform such an analysis by measuring I/O delays for a synthesized application that uses Parallel Distributed File System. The aim of this study was to evaluate the performance benefits of better disks in a multiprocessor system which was designed few years back. We report how the I/O performance would get affected if an application were to be run on a system which would have better disks and communication links. In this study, we show a substantial improvement in the performance of I/O system with better disks and communication links with respect to the existing system.

  12. 3-dimensional magnetotelluric inversion including topography using deformed hexahedral edge finite elements and direct solvers parallelized on symmetric multiprocessor computers - Part II: direct data-space inverse solution

    NASA Astrophysics Data System (ADS)

    Kordy, M.; Wannamaker, P.; Maris, V.; Cherkaev, E.; Hill, G.

    2016-01-01

    Following the creation described in Part I of a deformable edge finite-element simulator for 3-D magnetotelluric (MT) responses using direct solvers, in Part II we develop an algorithm named HexMT for 3-D regularized inversion of MT data including topography. Direct solvers parallelized on large-RAM, symmetric multiprocessor (SMP) workstations are used also for the Gauss-Newton model update. By exploiting the data-space approach, the computational cost of the model update becomes much less in both time and computer memory than the cost of the forward simulation. In order to regularize using the second norm of the gradient, we factor the matrix related to the regularization term and apply its inverse to the Jacobian, which is done using the MKL PARDISO library. For dense matrix multiplication and factorization related to the model update, we use the PLASMA library which shows very good scalability across processor cores. A synthetic test inversion using a simple hill model shows that including topography can be important; in this case depression of the electric field by the hill can cause false conductors at depth or mask the presence of resistive structure. With a simple model of two buried bricks, a uniform spatial weighting for the norm of model smoothing recovered more accurate locations for the tomographic images compared to weightings which were a function of parameter Jacobians. We implement joint inversion for static distortion matrices tested using the Dublin secret model 2, for which we are able to reduce nRMS to ˜1.1 while avoiding oscillatory convergence. Finally we test the code on field data by inverting full impedance and tipper MT responses collected around Mount St Helens in the Cascade volcanic chain. Among several prominent structures, the north-south trending, eruption-controlling shear zone is clearly imaged in the inversion.

  13. Parallel processing and expert systems

    NASA Technical Reports Server (NTRS)

    Lau, Sonie; Yan, Jerry C.

    1991-01-01

    Whether it be monitoring the thermal subsystem of Space Station Freedom, or controlling the navigation of the autonomous rover on Mars, NASA missions in the 1990s cannot enjoy an increased level of autonomy without the efficient implementation of expert systems. Merely increasing the computational speed of uniprocessors may not be able to guarantee that real-time demands are met for larger systems. Speedup via parallel processing must be pursued alongside the optimization of sequential implementations. Prototypes of parallel expert systems have been built at universities and industrial laboratories in the U.S. and Japan. The state-of-the-art research in progress related to parallel execution of expert systems is surveyed. The survey discusses multiprocessors for expert systems, parallel languages for symbolic computations, and mapping expert systems to multiprocessors. Results to date indicate that the parallelism achieved for these systems is small. The main reasons are (1) the body of knowledge applicable in any given situation and the amount of computation executed by each rule firing are small, (2) dividing the problem solving process into relatively independent partitions is difficult, and (3) implementation decisions that enable expert systems to be incrementally refined hamper compile-time optimization. In order to obtain greater speedups, data parallelism and application parallelism must be exploited.

  14. RT/OS — realtime programming and application environment for the COSY control system

    NASA Astrophysics Data System (ADS)

    Weinert, A.; Hacker, U.; Haberbosch, Ch.; Henn, K.; Simon, M.

    1994-12-01

    This paper presents the highlights and constraints of RT/OS and how it can be used at other places. The support of approximately 1000 VME and VXI CPUs in network-based multiprocessor systems needs a special set of programming tools and application environment which are bundled as the RT/OS Real-Time-Operating-System. Supporting the Motorola 680χ0 processors and micro-controller with a development system on UNIX and MS-DOS platforms, the tool set gives the opportunity of bringing small embedded controllers as well as VME multiprocessor systems into operation. The tool set includes a cross compiler and a special version of a remote debugger, as well as application support such as downloading and configuration management. The main feature is a modular kernel with message-based task switching, using the rendezvous principle to allow easy extension. Special features of this kernel for a distributed system are networking with the Berkeley socket library supporting TCP/IP, XNS and Novell Netware, a multiprocessor system on VMEbus with the interprocessor Communication Module (IPC), a device driver library for almost every G64 I/O card using a FieldBus Interface called PDV and a X11R4 port.

  15. DIstributed VIRtual System (DIVIRS) project

    NASA Technical Reports Server (NTRS)

    Schorr, Herbert; Neuman, Clifford B.

    1995-01-01

    As outlined in our continuation proposal 92-ISI-50R (revised) on NASA cooperative agreement NCC2-539, we are (1) developing software, including a system manager and a job manager, that will manage available resources and that will enable programmers to develop and execute parallel applications in terms of a virtual configuration of processors, hiding the mapping to physical nodes; (2) developing communications routines that support the abstractions implemented in item one; (3) continuing the development of file and information systems based on the Virtual System Model; and (4) incorporating appropriate security measures to allow the mechanisms developed in items 1 through 3 to be used on an open network. The goal throughout our work is to provide a uniform model that can be applied to both parallel and distributed systems. We believe that multiprocessor systems should exist in the context of distributed systems, allowing them to be more easily shared by those that need them. Our work provides the mechanisms through which nodes on multiprocessors are allocated to jobs running within the distributed system and the mechanisms through which files needed by those jobs can be located and accessed.

  16. Distributed Virtual System (DIVIRS) Project

    NASA Technical Reports Server (NTRS)

    Schorr, Herbert; Neuman, B. Clifford

    1993-01-01

    As outlined in our continuation proposal 92-ISI-50R (revised) on contract NCC 2-539, we are (1) developing software, including a system manager and a job manager, that will manage available resources and that will enable programmers to program parallel applications in terms of a virtual configuration of processors, hiding the mapping to physical nodes; (2) developing communications routines that support the abstractions implemented in item one; (3) continuing the development of file and information systems based on the virtual system model; and (4) incorporating appropriate security measures to allow the mechanisms developed in items 1 through 3 to be used on an open network. The goal throughout our work is to provide a uniform model that can be applied to both parallel and distributed systems. We believe that multiprocessor systems should exist in the context of distributed systems, allowing them to be more easily shared by those that need them. Our work provides the mechanisms through which nodes on multiprocessors are allocated to jobs running within the distributed system and the mechanisms through which files needed by those jobs can be located and accessed.

  17. DIstributed VIRtual System (DIVIRS) project

    NASA Technical Reports Server (NTRS)

    Schorr, Herbert; Neuman, B. Clifford

    1994-01-01

    As outlined in our continuation proposal 92-ISI-. OR (revised) on NASA cooperative agreement NCC2-539, we are (1) developing software, including a system manager and a job manager, that will manage available resources and that will enable programmers to develop and execute parallel applications in terms of a virtual configuration of processors, hiding the mapping to physical nodes; (2) developing communications routines that support the abstractions implemented in item one; (3) continuing the development of file and information systems based on the Virtual System Model; and (4) incorporating appropriate security measures to allow the mechanisms developed in items 1 through 3 to be used on an open network. The goal throughout our work is to provide a uniform model that can be applied to both parallel and distributed systems. We believe that multiprocessor systems should exist in the context of distributed systems, allowing them to be more easily shared by those that need them. Our work provides the mechanisms through which nodes on multiprocessors are allocated to jobs running within the distributed system and the mechanisms through which files needed by those jobs can be located and accessed.

  18. Distributed Virtual System (DIVIRS) project

    NASA Technical Reports Server (NTRS)

    Schorr, Herbert; Neuman, B. Clifford

    1993-01-01

    As outlined in the continuation proposal 92-ISI-50R (revised) on NASA cooperative agreement NCC 2-539, the investigators are developing software, including a system manager and a job manager, that will manage available resources and that will enable programmers to develop and execute parallel applications in terms of a virtual configuration of processors, hiding the mapping to physical nodes; developing communications routines that support the abstractions implemented; continuing the development of file and information systems based on the Virtual System Model; and incorporating appropriate security measures to allow the mechanisms developed to be used on an open network. The goal throughout the work is to provide a uniform model that can be applied to both parallel and distributed systems. The authors believe that multiprocessor systems should exist in the context of distributed systems, allowing them to be more easily shared by those that need them. The work provides the mechanisms through which nodes on multiprocessors are allocated to jobs running within the distributed system and the mechanisms through which files needed by those jobs can be located and accessed.

  19. Implementation of parallel matrix decomposition for NIKE3D on the KSR1 system

    SciTech Connect

    Su, Philip S.; Fulton, R.E.; Zacharia, T.

    1995-06-01

    New massively parallel computer architecture has revolutionized the design of computer algorithms and promises to have significant influence on algorithms for engineering computations. Realistic engineering problems using finite element analysis typically imply excessively large computational requirements. Parallel supercomputers that have the potential for significantly increasing calculation speeds can meet these computational requirements. This report explores the potential for the parallel Cholesky (U{sup T}DU) matrix decomposition algorithm on NIKE3D through actual computations. The examples of two- and three-dimensional nonlinear dynamic finite element problems are presented on the Kendall Square Research (KSR1) multiprocessor system, with 64 processors, at Oak Ridge National Laboratory. The numerical results indicate that the parallel Cholesky (U{sup T}DU) matrix decomposition algorithm is attractive for NIKE3D under multi-processor system environments.

  20. TbGT8 is a bifunctional glycosyltransferase that elaborates N-linked glycans on a protein phosphatase AcP115 and a GPI-anchor modifying glycan in Trypanosoma brucei.

    PubMed

    Nakanishi, Masayuki; Karasudani, Moe; Shiraishi, Takahiro; Hashida, Kazunori; Hino, Mami; Ferguson, Michael A J; Nomoto, Hiroshi

    2014-06-01

    The procyclic form of Trypanosoma brucei expresses procyclin surface glycoproteins with unusual glycosylphosphatidylinositol-anchor side chain structures that contain branched N-acetyllactosamine and lacto-N-biose units. The glycosyltransferase TbGT8 is involved in the synthesis of the branched side chain through its UDP-GlcNAc: βGal β1-3N-acetylglucosaminyltransferase activity. Here, we explored the role of TbGT8 in the mammalian bloodstream form of the parasite with a tetracycline-inducible conditional null T. brucei mutant for TbGT8. Under non-permissive conditions, the mutant showed significantly reduced binding to tomato lectin, which recognizes poly-N-acetyllactosamine-containing glycans. Lectin pull-down assays revealed differences between the wild type and TbGT8 null-mutant T. brucei, notably the absence of a broad protein band with an approximate molecular weight of 110 kDa in the mutant lysate. Proteomic analysis revealed that the band contained several glycoproteins, including the acidic ecto-protein phosphatase AcP115, a stage-specific glycoprotein in the bloodstream form of T. brucei. Western blotting with an anti-AcP115 antibody revealed that AcP115 was approximately 10kDa smaller in the mutant. Enzymatic de-N-glycosylation demonstrated that the underlying protein cores were the same, suggesting that the 10-kDa difference was due to differences in N-linked glycans. Immunofluorescence microscopy revealed the colocalization of hemagglutinin epitope-tagged TbGT8 and the Golgi-associated protein GRASP. These data suggest that TbGT8 is involved in the construction of complex poly-N-acetyllactosamine-containing type N-linked and GPI-linked glycans in the Golgi of the bloodstream and procyclic parasite forms, respectively. PMID:24508870

  1. Liquid chromatography-high resolution/ high accuracy (tandem) mass spectrometry-based identification of in vivo generated metabolites of the selective androgen receptor modulator ACP-105 for doping control purposes.

    PubMed

    Thevis, Mario; Thomas, Andreas; Piper, Thomas; Krug, Oliver; Delahaut, Philippe; Schänzer, Wilhelm

    2014-01-01

    Selective androgen receptor modulators (SARMs) represent an emerging class of therapeutics which have been prohibited in sport as anabolic agents according to the regulations of the World Anti-Doping Agency (WADA) since 2008. Within the past three years, numerous adverse analytical findings with SARMs in routine doping control samples have been reported despite missing clinical approval of these substances. Hence, preventive doping research concerning the metabolism and elimination of new therapeutic entities of the class of SARMs are vital for efficient and timely sports drug testing programs as banned compounds are most efficiently screened when viable targets (for example, characteristic metabolites) are identified. In the present study, the metabolism of ACP-105, a novel SARM drug candidate, was studied in vivo in rats. Following oral administration, urine samples were collected over a period of seven days and analyzed for metabolic products by Liquid chromatography-high resolution/high accuracy (tandem) mass spectrometry. Samples were subjected to enzymatic hydrolysis prior to liquid-liquid extraction and a total of seven major phase-I metabolites were detected, three of which were attributed to monohydroxylated and four to bishydroxylated ACP-105. The hydroxylation sites were assigned by means of diagnostic product ions and respective dissociation pathways of the analytes following positive or negative ionization and collisional activation as well as selective chemical derivatization. The identified metabolites were used as target compounds to investigate their traceability in a rat elimination urine samples study and monohydroxylated and bishydroxylated species were detectable for up to four and six days post-administration, respectively. PMID:24881457

  2. An acpXL Mutant of Rhizobium leguminosarum bv. phaseoli Lacks 27-Hydroxyoctacosanoic Acid in Its Lipid A and Is Developmentally Delayed during Symbiotic Infection of the Determinate Nodulating Host Plant Phaseolus vulgaris ▿

    PubMed Central

    Brown, Dusty B.; Huang, Yu-Chu; Kannenberg, Elmar L.; Sherrier, D. Janine; Carlson, Russell W.

    2011-01-01

    Rhizobium leguminosarum is a Gram-negative bacterium that forms nitrogen-fixing symbioses with compatible leguminous plants via intracellular invasion and establishes a persistent infection within host membrane-derived subcellular compartments. Notably, an unusual very-long-chain fatty acid (VLCFA) is found in the lipid A of R. leguminosarum as well as in the lipid A of the medically relevant pathogens Brucella abortus, Brucella melitensis, Bartonella henselae, and Legionella pneumophila, which are also able to persist within intracellular host-derived membranes. These bacterial symbionts and pathogens each contain a homologous gene region necessary for the synthesis and transfer of the VLCFA to the lipid A. Within this region lies a gene that encodes the specialized acyl carrier protein AcpXL, on which the VLCFA is built. This study describes the biochemical and infection phenotypes of an acpXL mutant which lacks the VLCFA. The mutation was created in R. leguminosarum bv. phaseoli strain 8002, which forms symbiosis with Phaseolus vulgaris, a determinate nodulating legume. Structural analysis using gas chromatography and mass spectrometry revealed that the mutant lipid A lacked the VLCFA. Compared to the parent strain, the mutant was more sensitive to the detergents deoxycholate and dodecyl sulfate and the antimicrobial peptide polymyxin B, suggesting a compromise to membrane stability. In addition, the mutant was more sensitive to higher salt concentrations. Passage through the plant restored salt tolerance. Electron microscopic examination showed that the mutant was developmentally delayed during symbiotic infection of the host plant Phaseolus vulgaris and produced abnormal symbiosome structures. PMID:21764936

  3. Multi-processing system study

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The results are summarized of a multiprocessor systems design review. The systems were reviewed against use in a space station environment. The proposed designs were evaluated from a systems viewpoint in general and from the systems software in particular. The recommendations resulting from this evaluation are anticipated to be considered for the design of a multiprocessing system built around a SUMC. Two multiprocessing system designs were reviewed. The designs reviewed were highly functional and many questions could not be answered. However, several major issues were uncovered which could be evaluated to some detail, and which could greatly impact the SUMC-MP design. The major issues relevant to a multiprocessing system design revolve around the following functions: (1) Storage Management, (2) Processor Management, (3) Intermodule Communication, (4) Memory Access Interference, (5) System Efficiency, and (6) System Recovery/Reliability.

  4. Instrumented Architectural Simulation System

    NASA Technical Reports Server (NTRS)

    Delagi, B. A.; Saraiya, N.; Nishimura, S.; Byrd, G.

    1987-01-01

    Simulation of systems at an architectural level can offer an effective way to study critical design choices if (1) the performance of the simulator is adequate to examine designs executing significant code bodies, not just toy problems or small application fragements, (2) the details of the simulation include the critical details of the design, (3) the view of the design presented by the simulator instrumentation leads to useful insights on the problems with the design, and (4) there is enough flexibility in the simulation system so that the asking of unplanned questions is not suppressed by the weight of the mechanics involved in making changes either in the design or its measurement. A simulation system with these goals is described together with the approach to its implementation. Its application to the study of a particular class of multiprocessor hardware system architectures is illustrated.

  5. Focus and Objectives for Effecting Near-Term Improvements to Bipropellant Earth Storable Propulsion Systems

    NASA Astrophysics Data System (ADS)

    Byers, Dave C.

    2006-12-01

    NASA’s In-Space Propulsion Technology (ISPT) Program is investing in Advanced Chemical Propulsion (ACP) technologies with the goal of enhancing propulsion system performance and science exploration mission capability in the nearto mid-term. These investments are currently focused on applying significant incremental technology improvements to state-of-the-art bipropellant propulsion systems for near-term implementation and adoption. Improvements in high temperature materials and processes for thrust chamber assemblies, lightweight composite tanks, and propellant management and delivery systems indicate potential for significantly reducing system mass and significantly increasing propellant performance. The current ACP development strategy and approach will mature technologies that can deliver these improvements while reducing manufacturing costs and increasing system reliability.

  6. Models for evaluating the performability of degradable computing systems

    NASA Technical Reports Server (NTRS)

    Wu, L. T.

    1982-01-01

    Recent advances in multiprocessor technology established the need for unified methods to evaluate computing systems performance and reliability. In response to this modeling need, a general modeling framework that permits the modeling, analysis and evaluation of degradable computing systems is considered. Within this framework, several user oriented performance variables are identified and shown to be proper generalizations of the traditional notions of system performance and reliability. Furthermore, a time varying version of the model is developed to generalize the traditional fault tree reliability evaluation methods of phased missions.

  7. Revisiting the cell biology of the acyl-ACP:phosphate transacylase PlsX suggests that the phospholipid synthesis and cell division machineries are not coupled in Bacillus subtilis.

    PubMed

    Sastre, Diego Emiliano; Bisson-Filho, Alexandre; de Mendoza, Diego; Gueiros-Filho, Frederico J

    2016-05-01

    PlsX is a central enzyme of phospholipid synthesis in bacteria, converting acyl-ACP to acyl-phosphate on the pathway to phosphatidic acid formation. PlsX has received attention because it plays a key role in the coordination of fatty acid and phospholipid synthesis. Recently, PlsX was also suggested to coordinate membrane synthesis with cell division in Bacillus subtilis. Here, we have re-investigated the cell biology of PlsX and determined that the enzyme is uniformly distributed on the membrane of most cells, but occasionally appears as membrane foci as well. Foci and homogenous patterns seem freely interconvertible but the prevalence of the uniform staining suggests that PlsX does not need to localize to specific sites to function correctly. We also investigated the relationship between PlsX and the divisome. In contrast to previous observations, PlsX's foci showed no obvious periodicity of localization and did not colocalize with the divisome. Furthermore, depletion of PlsX did not affect cell division if phospholipid synthesis is maintained by an alternative enzyme. These results suggest that coordination between division and membrane synthesis may not require physical or functional interactions between the divisome and phospholipid synthesis enzymes. PMID:26816052

  8. Firing distance estimation based on the analysis of GSR distribution on the target surface using ICP-MS--an experimental study with a 7.65 mm × 17 mm Browning pistol (.32 ACP).

    PubMed

    Santos, Agostinho; Ramos, Patrícia; Fernandes, Luís; Magalhães, Teresa; Almeida, Agostinho; Sousa, António

    2015-02-01

    An experimental study aiming to estimate the firing distance was conducted using a 7.65 mm × 17 mm Browning (.32ACP) pistol. Briefly, test shots were made against a target of cotton tissue (35 cm × 35 cm), and the amounts of antimony (Sb), barium (Ba), and lead (Pb) deposited in quadrangular pieces (1 cm × 1 cm) of the target cut from four radial positions at increasing distances from the bullet entrance hole ("samples") were determined by inductively coupled plasma-mass spectrometry (ICP-MS). The data obtained were used to search for a mathematical model for estimating the firing distance. The best model was a simple linear correlation between FD (the firing distance) and ln c (where c is the content of Sb, Ba or Pb in the samples, expressed in μg/g of target tissue). Best results were obtained with samples collected at radial distances within 2.0-3.0 cm from the bullet entrance hole. Using this approach, it was possible to accurately (±6 cm) estimate the firing distance in the interval [20-90] cm from the target. PMID:25553356

  9. The Galley Parallel File System

    NASA Technical Reports Server (NTRS)

    Nieuwejaar, Nils; Kotz, David

    1996-01-01

    As the I/O needs of parallel scientific applications increase, file systems for multiprocessors are being designed to provide applications with parallel access to multiple disks. Many parallel file systems present applications with a conventional Unix-like interface that allows the application to access multiple disks transparently. The interface conceals the parallelism within the file system, which increases the ease of programmability, but makes it difficult or impossible for sophisticated programmers and libraries to use knowledge about their I/O needs to exploit that parallelism. Furthermore, most current parallel file systems are optimized for a different workload than they are being asked to support. We introduce Galley, a new parallel file system that is intended to efficiently support realistic parallel workloads. We discuss Galley's file structure and application interface, as well as an application that has been implemented using that interface.

  10. Instructional image processing on a university mainframe: The Kansas system

    NASA Technical Reports Server (NTRS)

    Williams, T. H. L.; Siebert, J.; Gunn, C.

    1981-01-01

    An interactive digital image processing program package was developed that runs on the University of Kansas central computer, a Honeywell Level 66 multi-processor system. The module form of the package allows easy and rapid upgrades and extensions of the system and is used in remote sensing courses in the Department of Geography, in regional five-day short courses for academics and professionals, and also in remote sensing projects and research. The package comprises three self-contained modules of processing functions: Subimage extraction and rectification; image enhancement, preprocessing and data reduction; and classification. Its use in a typical course setting is described. Availability and costs are considered.

  11. Design and implementation of highly parallel pipelined VLSI systems

    NASA Astrophysics Data System (ADS)

    Delange, Alphonsus Anthonius Jozef

    A methodology and its realization as a prototype CAD (Computer Aided Design) system for the design and analysis of complex multiprocessor systems is presented. The design is an iterative process in which the behavioral specifications of the system components are refined into structural descriptions consisting of interconnections and lower level components etc. A model for the representation and analysis of multiprocessor systems at several levels of abstraction and an implementation of a CAD system based on this model are described. A high level design language, an object oriented development kit for tool design, a design data management system, and design and analysis tools such as a high level simulator and graphics design interface which are integrated into the prototype system and graphics interface are described. Procedures for the synthesis of semiregular processor arrays, and to compute the switching of input/output signals, memory management and control of processor array, and sequencing and segmentation of input/output data streams due to partitioning and clustering of the processor array during the subsequent synthesis steps, are described. The architecture and control of a parallel system is designed and each component mapped to a module or module generator in a symbolic layout library, compacted for design rules of VLSI (Very Large Scale Integration) technology. An example of the design of a processor that is a useful building block for highly parallel pipelined systems in the signal/image processing domains is given.

  12. Human nervous system function emulator.

    PubMed

    Frenger, P

    2000-01-01

    This paper describes a modular, extensible, open-systems design for a multiprocessor network which emulates the major functions of the human nervous system. Interchangeable hardware/software components, a socketed software bus with plug-and-play capability and self diagnostics are included. The computer hardware is based on IEEE P996.1 bus cards. Its operating system utilizes IEEE 1275 standard software. Object oriented design techniques and programming are featured. A machine-independent high level script-based command language was created for this project. Neural anatomical structures which were emulated include the cortex, brainstem, cerebellum, spinal cord, autonomic and peripheral nervous systems. Motor, sensory, autoregulatory, and higher cognitive artificial intelligence, behavioral and emotional functions are provided. The author discusses how he has interfaced this emulator to machine vision, speech recognition/speech synthesis, an artificial neural network and a dexterous hand to form an android robotic platform. PMID:10834247

  13. The Automated Instrumentation and Monitoring System (AIMS) reference manual

    NASA Technical Reports Server (NTRS)

    Yan, Jerry; Hontalas, Philip; Listgarten, Sherry

    1993-01-01

    Whether a researcher is designing the 'next parallel programming paradigm,' another 'scalable multiprocessor' or investigating resource allocation algorithms for multiprocessors, a facility that enables parallel program execution to be captured and displayed is invaluable. Careful analysis of execution traces can help computer designers and software architects to uncover system behavior and to take advantage of specific application characteristics and hardware features. A software tool kit that facilitates performance evaluation of parallel applications on multiprocessors is described. The Automated Instrumentation and Monitoring System (AIMS) has four major software components: a source code instrumentor which automatically inserts active event recorders into the program's source code before compilation; a run time performance-monitoring library, which collects performance data; a trace file animation and analysis tool kit which reconstructs program execution from the trace file; and a trace post-processor which compensate for data collection overhead. Besides being used as prototype for developing new techniques for instrumenting, monitoring, and visualizing parallel program execution, AIMS is also being incorporated into the run-time environments of various hardware test beds to evaluate their impact on user productivity. Currently, AIMS instrumentors accept FORTRAN and C parallel programs written for Intel's NX operating system on the iPSC family of multi computers. A run-time performance-monitoring library for the iPSC/860 is included in this release. We plan to release monitors for other platforms (such as PVM and TMC's CM-5) in the near future. Performance data collected can be graphically displayed on workstations (e.g. Sun Sparc and SGI) supporting X-Windows (in particular, Xl IR5, Motif 1.1.3).

  14. Evaluating thermodynamic integration performance of the new amber molecular dynamics package and assess potential halogen bonds of enoyl-ACP reductase (FabI) benzimidazole inhibitors.

    PubMed

    Su, Pin-Chih; Johnson, Michael E

    2016-04-01

    Thermodynamic integration (TI) can provide accurate binding free energy insights in a lead optimization program, but its high computational expense has limited its usage. In the effort of developing an efficient and accurate TI protocol for FabI inhibitors lead optimization program, we carefully compared TI with different Amber molecular dynamics (MD) engines (sander and pmemd), MD simulation lengths, the number of intermediate states and transformation steps, and the Lennard-Jones and Coulomb Softcore potentials parameters in the one-step TI, using eleven benzimidazole inhibitors in complex with Francisella tularensis enoyl acyl reductase (FtFabI). To our knowledge, this is the first study to extensively test the new AMBER MD engine, pmemd, on TI and compare the parameters of the Softcore potentials in the one-step TI in a protein-ligand binding system. The best performing model, the one-step pmemd TI, using 6 intermediate states and 1 ns MD simulations, provides better agreement with experimental results (RMSD = 0.52 kcal/mol) than the best performing implicit solvent method, QM/MM-GBSA from our previous study (RMSD = 3.00 kcal/mol), while maintaining similar efficiency. Briefly, we show the optimized TI protocol to be highly accurate and affordable for the FtFabI system. This approach can be implemented in a larger scale benzimidazole scaffold lead optimization against FtFabI. Lastly, the TI results here also provide structure-activity relationship insights, and suggest the parahalogen in benzimidazole compounds might form a weak halogen bond with FabI, which is a well-known halogen bond favoring enzyme. PMID:26666582

  15. Alpha: A real-time decentralized operating system for mission-oriented system integration and operation

    NASA Technical Reports Server (NTRS)

    Jensen, E. Douglas

    1988-01-01

    Alpha is a new kind of operating system that is unique in two highly significant ways. First, it is decentralized transparently providing reliable resource management across physically dispersed nodes, so that distributed applications programming can be done largely as though it were centralized. And second, it provides comprehensive, high technology support for real-time system integration and operation, an application area which consists predominately of aperiodic activities having critical time constraints such as deadlines. Alpha is extremely adaptable so that it can be easily optimized for a wide range of problem-specific functionality, performance, and cost. Alpha is the first systems effort of the Archons Project, and the prototype was created at Carnegie-Mellon University directly on modified Sun multiprocessor workstation hardware. It has been demonstrated with a real-time C(sup 2) application. Continuing research is leading to a series of enhanced follow-ons to Alpha; these are portable but initially hosted on Concurrent's MASSCOMP line of multiprocessor products.

  16. Architecture and grid application of cluster computing system

    NASA Astrophysics Data System (ADS)

    Lv, Yi; Yu, Shuiqin; Mao, Youju

    2004-11-01

    Recently, people pay more attention to the grid technology. It can not only connect all kinds of resources in the network, but also put them into a super transparent computing environment for customers to realize mete-computing which can share computing resources. Traditional parallel computing system, such as SMP(Symmetrical multiprocessor) and MPP(massively parallel processor), use multi-processors to raise computing speed in a close coupling way, so the flexible and scalable performance of the system are limited, as a result of it, the system can't meet the requirement of the grid technology. In this paper, the architecture of cluster computing system applied in grid nodes is introduced. It mainly includes the following aspects. First, the network architecture of cluster computing system in grid nodes is analyzed and designed. Second, how to realize distributing computing (including coordinating computing and sharing computing) of cluster computing system in grid nodes to construct virtual node computers is discussed. Last, communication among grid nodes is analyzed. In other words, it discusses how to realize single reflection to let all the service requirements from customers be met through sending to the grid nodes.

  17. On the ∆ACP saga

    NASA Astrophysics Data System (ADS)

    Santorelli, Pietro

    2014-11-01

    We discuss a model in which the large SU(3) flavor violations in singly Cabibbo suppressed decays of neutral D mesons are ascribed exclusively to the final state interactions. The agreement with the experimental data on the branching ratios is obtained with large strong phase differences which are also necessary for substantial direct CP violation. While the value of the CP violating asymmetries depends on the strength of the penguin contribution, we predict an asymmetry for the decays into charged pions more than twice larger than that for charged kaons and having opposite sign.

  18. Parallelism In Rule-Based Systems

    NASA Astrophysics Data System (ADS)

    Sabharwal, Arvind; Iyengar, S. Sitharama; de Saussure, G.; Weisbin, C. R.

    1988-03-01

    Rule-based systems, which have proven to be extremely useful for several Artificial Intelligence and Expert Systems applications, currently face severe limitations due to the slow speed of their execution. To achieve the desired speed-up, this paper addresses the problem of parallelization of production systems and explores the various architectural and algorithmic possibilities. The inherent sources of parallelism in the production system structure are analyzed and the trade-offs, limitations and feasibility of exploitation of these sources of parallelism are presented. Based on this analysis, we propose a dedicated, coarse-grained, n-ary tree multiprocessor architecture for the parallel implementation of rule-based systems and then present algorithms for partitioning of rules in this architecture.

  19. TOPOLOGY FOR A DSP BASED BEAM CONTROL SYSTEM IN THE AGS BOOSTER.

    SciTech Connect

    DELONG,J.BRENNAN,J.M.HAYES,T.LE,T.N.SMITH,K.

    2003-05-12

    The AGS Booster supports beams of ions and protons with a wide range of energies on a pulse-by-pulse modulation basis. This requires an agile beam control system highly integrated with its controls. To implement this system digital techniques in the form of Digital Signal Processors, Direct Digital Synthesizers, digital receivers and high speed Analog to Digital Converters are used. Signals from the beam and cavity pick-ups, as well as measurements of magnetic field strength in the ring dipoles are processed in real time. To facilitate this a multi-processor topology with high bandwidth data links is being designed.

  20. A new taxonomy for distributed computer systems based upon operating system structure

    NASA Technical Reports Server (NTRS)

    Foudriat, E. C.

    1985-01-01

    Characteristics of the resource structure found in the operating system are considered as a mechanism for classifying distributed computer systems. Since the operating system resources, themselves, are too diversified to provide a consistent classification, the structure upon which resources are built and shared are examined. The location and control character of this indivisibility provides the taxonomy for separating uniprocessors, computer networks, network computers (fully distributed processing systems or decentralized computers) and algorithm and/or data control multiprocessors. The taxonomy is important because it divides machines into a classification that is relevant or important to the client and not the hardware architect. It also defines the character of the kernel O/S structure needed for future computer systems. What constitutes an operating system for a fully distributed processor is discussed in detail.

  1. Isoniazid affects multiple components of the type II fatty acid synthase system of Mycobacterium tuberculosis.

    PubMed

    Slayden, R A; Lee, R E; Barry, C E

    2000-11-01

    Genetic and biochemical evidence has implicated two different target enzymes for isoniazid (INH) within the unique type II fatty acid synthase (FAS) system involved in the production of mycolic acids. These two components are an enoyl acyl carrier protein (ACP) reductase, InhA, and a beta-ketoacyl-ACP synthase, KasA. We compared the consequences of INH treatment of Mycobacterium tuberculosis (MTB) with two inhibitors having well-defined targets: triclosan (TRC), which inhibits InhA; and thiolactomycin (TLM), which inhibits KasA. INH and TLM, but not TRC, upregulate the expression of an operon containing five FAS II components, including kasA and acpM. Although all three compounds inhibit mycolic acid synthesis, treatment with INH and TLM, but not with TRC, results in the accumulation of ACP-bound lipid precursors to mycolic acids that were 26 carbons long and fully saturated. TLM-resistant mutants of MTB were more cross-resistant to INH than TRC-resistant mutants. Overexpression of KasA conferred more resistance to TLM and INH than to TRC. Overexpression of InhA conferred more resistance to TRC than to INH and TLM. Co-overexpression of both InhA and KasA resulted in strongly enhanced levels of INH resistance, in addition to cross-resistance to both TLM and TRC. These results suggest that these components of the FAS II complex are not independently regulated and that alterations in the expression level of InhA affect expression levels of KasA. Nonetheless, INH appeared to resemble TLM more closely in overall mode of action, and KasA levels appeared to be tightly correlated with INH sensitivity. PMID:11069675

  2. Using memory in the Cedar system

    SciTech Connect

    McGrath, R.E.; Emrath, P.

    1987-01-01

    The design of the virtual memory system for the Cedar multiprocessor under construction at the University of Illinois is discussed. The Cedar architecture features a hierarchy of memory, some shared by all processors, and some shared by subsets of processors. The Xylem operating system is based on Alliant Computer Systems CONCENTRIX(TM) operating system, which is based on 4.2BSD UNIX(TM). Xylem supports multi-tasking and demand paging of parts of the memory hierarchy into a linear virtual address space. Memory may be private to a task or shared between all the tasks. The locality and attributes of a page may be modified during the execution of a program. Examples of how these mechanisms can be used are discussed. 14 figs.

  3. ETHERNET BASED EMBEDDED IOC FOR FEL CONTROL SYSTEM

    SciTech Connect

    Jianxun Yan; Daniel Sexton; Albert Grippo; Steven Moore; Kevin Jordan

    2008-01-23

    An Ethernet based embedded Input Output Controller (IOC) has been developed to upgrade the control system for the Free Electron Laser Project at Jefferson Lab. The embedded IOC, called the Single Board IOC (SBIOC), was integrated with a ColdFire embedded microprocessor and a Field Programmable Gate Array (FPGA) on a circuit board, which can be easily configured to control different kinds of I/O devices. The SBIOC provided features of a complete System-on-Module (SOM) as a stand alone system with abundant high speed I/O ports to couple with suitable devices. The software kits, Experimental Physics and Industrial Control System (EPICS) and Real Time Executive for Multiprocessor System (RTEMS), were chosen to work with our existing control system. The embedded IOC system has the features of a low cost IOC, free open source RTOS, plug-and-play-like ease of installation and flexibility.

  4. Real-time visual tracking system modelling in MPSoC using platform based design

    NASA Astrophysics Data System (ADS)

    Jia, Zai Jian; Bautista, Tomás; Núñez, Antonio; Guerra, Cayetano; Hernández, Mario

    2009-02-01

    In this paper, we present the modelling of a real-time tracking system on a Multi-Processor System on Chip (MPSoC). Our final goal is to build a more complex computer vision system (CVS) by integrating several applications in a modular way, which performs different kind of data processing issues but sharing a common platform, and this way, a solution for a set of applications using the same architecture is offered and not just for one application. In our current work, a visual tracking system with real-time behaviour (25 frames/sec) is used like a reference application, and also, guidelines for our future CVS applications development. Our algorithm written in C++ is based on correlation technique and the threshold dynamic update approach. After an initial computational complexity analysis, a task-graph was generated from this tracking algorithm. Concurrently with this functionality correctness analysis, a generic model of multi-processor platform was developed. Finally, the tracking system performance mapped onto the proposed architecture and shared resource usage were analyzed to determine the real architecture capacity, and also to find out possible bottlenecks in order to propose new solutions which allow more applications to be mapped on the platform template in the future.

  5. Multicore Software Architectures on Virtualized Partitioned Systems

    NASA Astrophysics Data System (ADS)

    Carrascosa, E.; Masmano, M.; Balbastre, P.; Crespo, A.; Galizzi, J.

    2014-08-01

    Embedded system design is evolving in terms of complexity towards the use of multiprocessor architectures, increasing performance and reducing costs while presenting a low impact on critical design aspects. However, the use of multi-core technologies entails an increment in the level of indeterminism that is not acceptable for safety critical applications where predictability is crucial. This paper focuses on analysing the factors related to indeterminism on multicore systems and the methods to attenuate their impact, providing a series of guidelines aimed to obtain on-board software qualification. Time and space partitioning (TSP) is presented as a suitable mean to handle indeterminism, while XtratuM, an open source TSP hyper-visor designed to comply with safety critical real-time requirements, has been selected to adopt a practical approach to the subject.

  6. Global garbage collection for distributed heap storage systems

    SciTech Connect

    Ali, K.A.M.; Haridi, S.

    1986-10-01

    The authors present a garbage-collection algorithm, suitable for loosely-coupled multi-processor systems, in which the processing elements (PEs) share only the communication medium. The algorithm is global, i.e., it involves all the PEs in the system. It allows space compaction, and it uses a system-wide marking phase to mark all accessible objects where a combination of parallel breadth-first/depth-first strategies is used for tracing the object-graphs according to a decentralized credit mechanism that regulates the number of garbage collections messages in the system. The credit mechanism is crucial for determining the space requirement of the garbage-collection messages. Also a variation of this algorithm is presented for systems with high locality of reference. It allows each PE to perform first its local garbage collection and only invokes the global garbage collection when the freed space by the local collector is insufficient.

  7. Scalable Triadic Analysis of Large-Scale Graphs: Multi-Core vs. Multi-Processor vs. Multi-Threaded Shared Memory Architectures

    SciTech Connect

    Chin, George; Marquez, Andres; Choudhury, Sutanay; Feo, John T.

    2012-09-01

    Triadic analysis encompasses a useful set of graph mining methods that is centered on the concept of a triad, which is a subgraph of three nodes and the configuration of directed edges across the nodes. Such methods are often applied in the social sciences as well as many other diverse fields. Triadic methods commonly operate on a triad census that counts the number of triads of every possible edge configuration in a graph. Like other graph algorithms, triadic census algorithms do not scale well when graphs reach tens of millions to billions of nodes. To enable the triadic analysis of large-scale graphs, we developed and optimized a triad census algorithm to efficiently execute on shared memory architectures. We will retrace the development and evolution of a parallel triad census algorithm. Over the course of several versions, we continually adapted the code’s data structures and program logic to expose more opportunities to exploit parallelism on shared memory that would translate into improved computational performance. We will recall the critical steps and modifications that occurred during code development and optimization. Furthermore, we will compare the performances of triad census algorithm versions on three specific systems: Cray XMT, HP Superdome, and AMD multi-core NUMA machine. These three systems have shared memory architectures but with markedly different hardware capabilities to manage parallelism.

  8. Parallelism in the execution of a routine-knowledge rule system on the BUTTERFLY (trademark) computer. Technical report

    SciTech Connect

    Boulanger, A.

    1986-12-01

    This project ported a routine-knowledge rule system to the BUTTERFLY multiprocessor. The goal was to explore parallelization techniques with an existing rule system originally written for serial execution. The rule system was rewritten to introduce parallelism, and run on a single processor to establish a benchmark for serial operation. The same version, with parallelism enabled, was then run on a 16-node BUTTERFLY multiprocessor. The metering tools on the BUTTERFLY were used to display task behavior and processor utilization. The information gained from these displays was used to guide further experimentation with the granularity of the rules and with the system code to investigate bottlenecks that were lengthening execution time. The project demonstrated that parallelization of routine-knowledge rule systems can yield substantial speedup. It also demonstrated that the metering tools on the BUTTERFLY can be used to achieve additional speedup of parallel implementations. The implications of this research are discussed and compared to the findings of research at Carnegie-Mellon University on parallelizing production systems.

  9. An Analysis of System Balance Requirements for Scientific Applications

    SciTech Connect

    Alam, Sadaf R; Vetter, Jeffrey S

    2006-08-01

    Scientific applications are diverse in terms of the resource requirements, and tend to vary significantly from commercial applications. In order to provide sustained performance, a target high performance computing (HPC) platform must offer a balance between CPU performance to memory, interconnect and I/O subsystems performance. We characterize the system balance requirements for two large-scale Office of Science applications, GYRO (fusion simulation) and POP (climate modeling), and develop platform-independent parameterized requirement models. We measure the parallel efficiencies for GYRO and POP on three multiprocessor systems: an SMP cluster (IBM p690), a shared-memory system (SGI Altix) and a vector supercomputer (Cray X1). The higher computational intensity and interconnect bandwidth requirements of GYRO result in higher performance efficiencies on the vector platform. At the same time, small message sizes in POP benefit from low MPI latencies of the shared-memory platform. Overall results confirm system balance requirements that are generated by the requirement models.

  10. Critical Path-Based Thread Placement for NUMA Systems

    SciTech Connect

    Su, C Y; Li, D; Nikolopoulos, D S; Grove, M; Cameron, K; de Supinski, B R

    2011-11-01

    Multicore multiprocessors use a Non Uniform Memory Architecture (NUMA) to improve their scalability. However, NUMA introduces performance penalties due to remote memory accesses. Without efficiently managing data layout and thread mapping to cores, scientific applications, even if they are optimized for NUMA, may suffer performance loss. In this paper, we present algorithms and a runtime system that optimize the execution of OpenMP applications on NUMA architectures. By collecting information from hardware counters, the runtime system directs thread placement and reduces performance penalties by minimizing the critical path of OpenMP parallel regions. The runtime system uses a scalable algorithm that derives placement decisions with negligible overhead. We evaluate our algorithms and runtime system with four NPB applications implemented in OpenMP. On average the algorithms achieve between 8.13% and 25.68% performance improvement compared to the default Linux thread placement scheme. The algorithms miss the optimal thread placement in only 8.9% of the cases.

  11. 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.

  12. Identification of differentially expressed genes using an annealing control primer system in stage III serous ovarian carcinoma

    PubMed Central

    2010-01-01

    Background Most patients with ovarian cancer are diagnosed with advanced stage disease (i.e., stage III-IV), which is associated with a poor prognosis. Differentially expressed genes (DEGs) in stage III serous ovarian carcinoma compared to normal tissue were screened by a new differential display method, the annealing control primer (ACP) system. The potential targets for markers that could be used for diagnosis and prognosis, for stage III serous ovarian cancer, were found by cluster and survival analysis. Methods The ACP-based reverse transcriptase polymerase chain reaction (RT PCR) technique was used to identify DEGs in patients with stage III serous ovarian carcinoma. The DEGs identified by the ACP system were confirmed by quantitative real-time PCR. Cluster analysis was performed on the basis of the expression profile produced by quantitative real-time PCR and survival analysis was carried out by the Kaplan-Meier method and Cox proportional hazards multivariate model; the results of gene expression were compared between chemo-resistant and chemo-sensitive groups. Results A total of 114 DEGs were identified by the ACP-based RT PCR technique among patients with stage III serous ovarian carcinoma. The DEGs associated with an apoptosis inhibitory process tended to be up-regulated clones while the DEGs associated with immune response tended to be down-regulated clones. Cluster analysis of the gene expression profile obtained by quantitative real-time PCR revealed two contrasting groups of DEGs. That is, a group of genes including: SSBP1, IFI6 DDT, IFI27, C11orf92, NFKBIA, TNXB, NEAT1 and TFG were up-regulated while another group of genes consisting of: LAMB2, XRCC6, MEF2C, RBM5, FOXP1, NUDCP2, LGALS3, TMEM185A, and C1S were down-regulated in most patients. Survival analysis revealed that the up-regulated genes such as DDAH2, RNase K and TCEAL2 might be associated with a poor prognosis. Furthermore, the prognosis of patients with chemo-resistance was predicted to be

  13. Design and initial application of the extended aircraft interrogation and display system: Multiprocessing ground support equipment for digital flight systems

    NASA Technical Reports Server (NTRS)

    Glover, Richard D.

    1987-01-01

    A pipelined, multiprocessor, general-purpose ground support equipment for digital flight systems has been developed and placed in service at the NASA Ames Research Center's Dryden Flight Research Facility. The design is an outgrowth of the earlier aircraft interrogation and display system (AIDS) used in support of several research projects to provide engineering-units display of internal control system parameters during development and qualification testing activities. The new system, incorporating multiple 16-bit processors, is called extended AIDS (XAIDS) and is now supporting the X-29A forward-swept-wing aircraft project. This report describes the design and mechanization of XAIDS and shows the steps whereby a typical user may take advantage of its high throughput and flexible features.

  14. Absolute Cavity Pyrgeometer to Measure the Absolute Outdoor Longwave Irradiance with Traceability to International System of Units, SI

    SciTech Connect

    Reda, I.; Zeng, J.; Scheuch, J.; Hanssen, L.; Wilthan, B.; Myers, D.; Stoffel, T.

    2012-03-01

    This article describes a method of measuring the absolute outdoor longwave irradiance using an absolute cavity pyrgeometer (ACP), U.S. Patent application no. 13/049, 275. The ACP consists of domeless thermopile pyrgeometer, gold-plated concentrator, temperature controller, and data acquisition. The dome was removed from the pyrgeometer to remove errors associated with dome transmittance and the dome correction factor. To avoid thermal convection and wind effect errors resulting from using a domeless thermopile, the gold-plated concentrator was placed above the thermopile. The concentrator is a dual compound parabolic concentrator (CPC) with 180{sup o} view angle to measure the outdoor incoming longwave irradiance from the atmosphere. The incoming irradiance is reflected from the specular gold surface of the CPC and concentrated on the 11 mm diameter of the pyrgeometer's blackened thermopile. The CPC's interior surface design and the resulting cavitation result in a throughput value that was characterized by the National Institute of Standards and Technology. The ACP was installed horizontally outdoor on an aluminum plate connected to the temperature controller to control the pyrgeometer's case temperature. The responsivity of the pyrgeometer's thermopile detector was determined by lowering the case temperature and calculating the rate of change of the thermopile output voltage versus the changing net irradiance. The responsivity is then used to calculate the absolute atmospheric longwave irradiance with an uncertainty estimate (U{sub 95}) of {+-}3.96 W m{sup 02} with traceability to the International System of Units, SI. The measured irradiance was compared with the irradiance measured by two pyrgeometers calibrated by the World Radiation Center with traceability to the Interim World Infrared Standard Group, WISG. A total of 408 readings were collected over three different nights. The calculated irradiance measured by the ACP was 1.5 W/m{sup 2} lower than that

  15. An absolute cavity pyrgeometer to measure the absolute outdoor longwave irradiance with traceability to international system of units, SI

    NASA Astrophysics Data System (ADS)

    Reda, Ibrahim; Zeng, Jinan; Scheuch, Jonathan; Hanssen, Leonard; Wilthan, Boris; Myers, Daryl; Stoffel, Tom

    2012-03-01

    This article describes a method of measuring the absolute outdoor longwave irradiance using an absolute cavity pyrgeometer (ACP), U.S. Patent application no. 13/049, 275. The ACP consists of domeless thermopile pyrgeometer, gold-plated concentrator, temperature controller, and data acquisition. The dome was removed from the pyrgeometer to remove errors associated with dome transmittance and the dome correction factor. To avoid thermal convection and wind effect errors resulting from using a domeless thermopile, the gold-plated concentrator was placed above the thermopile. The concentrator is a dual compound parabolic concentrator (CPC) with 180° view angle to measure the outdoor incoming longwave irradiance from the atmosphere. The incoming irradiance is reflected from the specular gold surface of the CPC and concentrated on the 11 mm diameter of the pyrgeometer's blackened thermopile. The CPC's interior surface design and the resulting cavitation result in a throughput value that was characterized by the National Institute of Standards and Technology. The ACP was installed horizontally outdoor on an aluminum plate connected to the temperature controller to control the pyrgeometer's case temperature. The responsivity of the pyrgeometer's thermopile detector was determined by lowering the case temperature and calculating the rate of change of the thermopile output voltage versus the changing net irradiance. The responsivity is then used to calculate the absolute atmospheric longwave irradiance with an uncertainty estimate (U95) of ±3.96 W m-2 with traceability to the International System of Units, SI. The measured irradiance was compared with the irradiance measured by two pyrgeometers calibrated by the World Radiation Center with traceability to the Interim World Infrared Standard Group, WISG. A total of 408 readings were collected over three different nights. The calculated irradiance measured by the ACP was 1.5 W/m2 lower than that measured by the two

  16. Multi-system fibromyalgia syndrome emulator - biomed 2009.

    PubMed

    Frenger, Paul

    2009-01-01

    Fibromyalgia Syndrome is a chronic disorder characterized by abnormal pain, fatigue, depression, cognitive dysfunction and sleep disturbance. The body's immune, hormonal, and nervous systems are involved. The author proposes a model from his clinical practice where a relapsing human Herpesvirus 4 infection of ss-lymphocytes causes inappropriate activation of immune system components, thus leading to typical FMS signs and symptoms. This clinical model was subsequently embodied in a computer based on the author's human nervous system function emulator, which imitates the brain's biochemicalneural-cognitive operations. This Forth language emulator program runs on a multiprocessor network recently enhanced with 8-core 32-bit CPUs. Supplemental analog circuit boards provide support for an artificial neural network, synthetic emotion and cellular substrate-receptor binding activity simulation. The effects of antiviral antibiotics and other chemicals on this disease are included in the emulator. PMID:19369778

  17. Low Latency Messages on Distributed Memory Multiprocessors

    DOE PAGESBeta

    Rosing, Matt; Saltz, Joel

    1995-01-01

    This article describes many of the issues in developing an efficient interface for communication on distributed memory machines. Although the hardware component of message latency is less than 1 ws on many distributed memory machines, the software latency associated with sending and receiving typed messages is on the order of 50 μs. The reason for this imbalance is that the software interface does not match the hardware. By changing the interface to match the hardware more closely, applications with fine grained communication can be put on these machines. This article describes several tests performed and many of the issues involvedmore » in supporting low latency messages on distributed memory machines.« less

  18. Optimal cube-connected cube multiprocessors

    NASA Technical Reports Server (NTRS)

    Sun, Xian-He; Wu, Jie

    1993-01-01

    Many CFD (computational fluid dynamics) and other scientific applications can be partitioned into subproblems. However, in general the partitioned subproblems are very large. They demand high performance computing power themselves, and the solutions of the subproblems have to be combined at each time step. The cube-connect cube (CCCube) architecture is studied. The CCCube architecture is an extended hypercube structure with each node represented as a cube. It requires fewer physical links between nodes than the hypercube, and provides the same communication support as the hypercube does on many applications. The reduced physical links can be used to enhance the bandwidth of the remaining links and, therefore, enhance the overall performance. The concept and the method to obtain optimal CCCubes, which are the CCCubes with a minimum number of links under a given total number of nodes, are proposed. The superiority of optimal CCCubes over standard hypercubes was also shown in terms of the link usage in the embedding of a binomial tree. A useful computation structure based on a semi-binomial tree for divide-and-conquer type of parallel algorithms was identified. It was shown that this structure can be implemented in optimal CCCubes without performance degradation compared with regular hypercubes. The result presented should provide a useful approach to design of scientific parallel computers.

  19. Cell Multiprocessor Communication Network: Built for Speed

    SciTech Connect

    Kistler, Mike; Perrone, Michael; Petrini, Fabrizio

    2006-06-01

    The existence of major obstacles to the traditional path to processor performance improvement has led chip manufacturers to consider multi-core designs. These architectural solutions promise a variety of power/performance and area/performance benefits. But additional care must be taken to ensure that these benefits are not lost due to inadequate design of the on-chip communication network. This paper presents the design challenges of the on-chip network of the Cell Broadband Engine (Cell BE) processor, and describes in detail its architectural design and the network, communication and synchronization protocols. In the experimental evaluation, performed on an early prototype, we analyze the communication characteristics of the Cell BE processor, using a series of microbenchmarks involving various DMA traffic patterns and synchronization protocols. We find that the on-chip communication subsystem is well matched to the to computational capacity of the processor. A Synergistic Processing Element (SPE) can issue an internal direct memory access (DMA) operation in less than 4 nanoseconds, and a DMA of a single cache line can be executed in less the than 100 nanoseconds. SPEs can achieve the optimal bandwidth of 25.6 GB/second in point to point communication with surprisingly small messages ?only a few KB, using batches of non-blocking DMAs. The aggregate network behavior under heavy load is also remarkably efficient, reaching almost 200 GB/second with collective patterns and optimal contention resolution under hot-spot traffic. Additionally, we demonstrate the consistency of these hardware results with identical experiments carried out using the Mambo simulator software for Cell BE.

  20. REGIONAL OXIDANT MODEL MULTI-PROCESSOR (ROMMP)

    EPA Science Inventory

    EPA's Regional Oxidant Model (ROM), a three-dimensional model capable of describing photochemical smog on scales of 1000 km, is being used to analyze large-scale pollution patterns and the effectiveness of particular emissions control strategies on reducing ozone concentrations. ...

  1. Optimization of space trusses on vector multiprocessor

    SciTech Connect

    Adeli, H.; Hsu, H.L.

    1994-01-01

    Mathematical optimization of space trusses in a vector/parallel processing environment is the subject of this paper. Parallel processing is achieved through microtasking and the use of the CRAY CFT77 compiler directives. Speed-up results are presented for four space-truss examples. It is concluded that the speedup due to microtasking is improved substantially with an increase in the size of the problem.

  2. Parallel processing and expert systems

    NASA Technical Reports Server (NTRS)

    Yan, Jerry C.; Lau, Sonie

    1991-01-01

    Whether it be monitoring the thermal subsystem of Space Station Freedom, or controlling the navigation of the autonomous rover on Mars, NASA missions in the 90's cannot enjoy an increased level of autonomy without the efficient use of expert systems. Merely increasing the computational speed of uniprocessors may not be able to guarantee that real time demands are met for large expert systems. Speed-up via parallel processing must be pursued alongside the optimization of sequential implementations. Prototypes of parallel expert systems have been built at universities and industrial labs in the U.S. and Japan. The state-of-the-art research in progress related to parallel execution of expert systems was surveyed. The survey is divided into three major sections: (1) multiprocessors for parallel expert systems; (2) parallel languages for symbolic computations; and (3) measurements of parallelism of expert system. Results to date indicate that the parallelism achieved for these systems is small. In order to obtain greater speed-ups, data parallelism and application parallelism must be exploited.

  3. Problems related to the integration of fault tolerant aircraft electronic systems

    NASA Technical Reports Server (NTRS)

    Bannister, J. A.; Adlakha, V.; Triyedi, K.; Alspaugh, T. A., Jr.

    1982-01-01

    Problems related to the design of the hardware for an integrated aircraft electronic system are considered. Taxonomies of concurrent systems are reviewed and a new taxonomy is proposed. An informal methodology intended to identify feasible regions of the taxonomic design space is described. Specific tools are recommended for use in the methodology. Based on the methodology, a preliminary strawman integrated fault tolerant aircraft electronic system is proposed. Next, problems related to the programming and control of inegrated aircraft electronic systems are discussed. Issues of system resource management, including the scheduling and allocation of real time periodic tasks in a multiprocessor environment, are treated in detail. The role of software design in integrated fault tolerant aircraft electronic systems is discussed. Conclusions and recommendations for further work are included.

  4. Solving tridiagonal linear systems on the Butterfly parallel computer

    SciTech Connect

    Kumar, S.P.

    1989-01-01

    A parallel block partitioning method to solve a tri-diagonal system of linear equations is adapted to the BBN Butterfly multiprocessor. A performance analysis of the programming experiments on the 32-node Butterfly is presented. An upper bound on the number of processors to achieve the best performance with this method is derived. The computational results verify the theoretical speedup and efficiency results of the parallel algorithm over its serial counterpart. Also included is a study comparing performance runs of the same code on the Butterfly processor with a hardware floating point unit and on one with a software floating point facility. The total parallel time of the given code is considerably reduced by making use of the hardware floating point facility whereas the speedup and efficiency of the parallel program considerably improve on the system with software floating point capability. The achieved results are shown to be within 82% to 90% of the predicted performance.

  5. Analysis and design of algorithm-based fault-tolerant systems

    NASA Technical Reports Server (NTRS)

    Nair, V. S. Sukumaran

    1990-01-01

    An important consideration in the design of high performance multiprocessor systems is to ensure the correctness of the results computed in the presence of transient and intermittent failures. Concurrent error detection and correction have been applied to such systems in order to achieve reliability. Algorithm Based Fault Tolerance (ABFT) was suggested as a cost-effective concurrent error detection scheme. The research was motivated by the complexity involved in the analysis and design of ABFT systems. To that end, a matrix-based model was developed and, based on that, algorithms for both the design and analysis of ABFT systems are formulated. These algorithms are less complex than the existing ones. In order to reduce the complexity further, a hierarchical approach is developed for the analysis of large systems.

  6. Performance Monitoring of Distributed Data Processing Systems

    NASA Technical Reports Server (NTRS)

    Ojha, Anand K.

    2000-01-01

    Test and checkout systems are essential components in ensuring safety and reliability of aircraft and related systems for space missions. A variety of systems, developed over several years, are in use at the NASA/KSC. Many of these systems are configured as distributed data processing systems with the functionality spread over several multiprocessor nodes interconnected through networks. To be cost-effective, a system should take the least amount of resource and perform a given testing task in the least amount of time. There are two aspects of performance evaluation: monitoring and benchmarking. While monitoring is valuable to system administrators in operating and maintaining, benchmarking is important in designing and upgrading computer-based systems. These two aspects of performance evaluation are the foci of this project. This paper first discusses various issues related to software, hardware, and hybrid performance monitoring as applicable to distributed systems, and specifically to the TCMS (Test Control and Monitoring System). Next, a comparison of several probing instructions are made to show that the hybrid monitoring technique developed by the NIST (National Institutes for Standards and Technology) is the least intrusive and takes only one-fourth of the time taken by software monitoring probes. In the rest of the paper, issues related to benchmarking a distributed system have been discussed and finally a prescription for developing a micro-benchmark for the TCMS has been provided.

  7. Performance analysis of fault-tolerant systems in parallel execution of conversations

    NASA Technical Reports Server (NTRS)

    Kim, K. H.; Heu, Shin; Yang, Seung M.

    1989-01-01

    The execution overhead inherent in the conversation scheme, which is a scheme for realizing fault-tolerant cooperating processes free of the domino effect, is analyzed. Multiprocessor/multicomputer systems capable of parallel execution of conversation components are considered and a queuing network model of such systems is adopted. Based on the queuing model, various performance indicators, including system throughput, average number of processors idling inside a conversation due to the synchronization required, and average time spent in the conversation, have been evaluated numerically for several application environments. The numeric results are discussed and several essential performance characteristics of the conversation scheme are derived. For example, when the number of participant processes is not large, say less than six, the system performance is highly affected by the synchronization required on the processes in a conversation, and not so much by the probability of acceptance-test failure.

  8. Information management system breadboard data acquisition and control system.

    NASA Technical Reports Server (NTRS)

    Mallary, W. E.

    1972-01-01

    Description of a breadboard configuration of an advanced information management system based on requirements for high data rates and local and centralized computation for subsystems and experiments to be housed on a space station. The system is to contain a 10-megabit-per-second digital data bus, remote terminals with preprocessor capabilities, and a central multiprocessor. A concept definition is presented for the data acquisition and control system breadboard, and a detailed account is given of the operation of the bus control unit, the bus itself, and the remote acquisition and control unit. The data bus control unit is capable of operating under control of both its own test panel and the test processor. In either mode it is capable of both single- and multiple-message operation in that it can accept a block of data requests or update commands for transmission to the remote acquisition and control unit, which in turn is capable of three levels of data-handling complexity.

  9. Research on computer systems benchmarking

    NASA Technical Reports Server (NTRS)

    Smith, Alan Jay (Principal Investigator)

    1996-01-01

    This grant addresses the topic of research on computer systems benchmarking and is more generally concerned with performance issues in computer systems. This report reviews work in those areas during the period of NASA support under this grant. The bulk of the work performed concerned benchmarking and analysis of CPUs, compilers, caches, and benchmark programs. The first part of this work concerned the issue of benchmark performance prediction. A new approach to benchmarking and machine characterization was reported, using a machine characterizer that measures the performance of a given system in terms of a Fortran abstract machine. Another report focused on analyzing compiler performance. The performance impact of optimization in the context of our methodology for CPU performance characterization was based on the abstract machine model. Benchmark programs are analyzed in another paper. A machine-independent model of program execution was developed to characterize both machine performance and program execution. By merging these machine and program characterizations, execution time can be estimated for arbitrary machine/program combinations. The work was continued into the domain of parallel and vector machines, including the issue of caches in vector processors and multiprocessors. All of the afore-mentioned accomplishments are more specifically summarized in this report, as well as those smaller in magnitude supported by this grant.

  10. The DECam data acquisition and control system

    NASA Astrophysics Data System (ADS)

    Honscheid, K.; Eiting, J.; Elliott, A.; Annis, J.; Bonati, M.; Buckley-Geer, E.; Castander, F.; da Costa, L.; Haney, M.; Hanlon, W.; Karliner, I.; Kuehn, K.; Kuhlmann, S.; Marshall, S.; Meyer, M.; Neilsen, E.; Ogando, R.; Roodman, A.; Schalk, T.; Schumacher, G.; Selen, M.; Serrano, S.; Thaler, J.; Wester, W.

    2010-07-01

    In this paper we describe the data acquisition and control system of the Dark Energy Camera (DECam), which will be the primary instrument used in the Dark Energy Survey (DES). DES is a high precision multibandpath wide area survey of 5000 square degrees of the southern sky. DECam currently under construction at Fermilab will be a 3 square degree mosaic camera mounted at the prime focus of the Blanco 4m telescope at the Cerro-Tololo International Observatory (CTIO). The DECam data acquisition system (SISPI) is implemented as a distributed multi-processor system with a software architecture built on the Client-Server and Publish-Subscribe design patterns. The underlying message passing protocol is based on PYRO, a powerful distributed object technology system written entirely in Python. A distributed shared variable system was added to support exchange of telemetry data and other information between different components of the system. In this paper we discuss the SISPI infrastructure software, the image pipeline, the observer interface and quality monitoring system, and the instrument control system.

  11. Parallel of low-level computer vision algorithms on a multi-DSP system

    NASA Astrophysics Data System (ADS)

    Liu, Huaida; Jia, Pingui; Li, Lijian; Yang, Yiping

    2011-06-01

    Parallel hardware becomes a commonly used approach to satisfy the intensive computation demands of computer vision systems. A multiprocessor architecture based on hypercube interconnecting digital signal processors (DSPs) is described to exploit the temporal and spatial parallelism. This paper presents a parallel implementation of low level vision algorithms designed on multi-DSP system. The convolution operation has been parallelized by using redundant boundary partitioning. Performance of the parallel convolution operation is investigated by varying the image size, mask size and the number of processors. Experimental results show that the speedup is close to the ideal value. However, it can be found that the loading imbalance of processor can significantly affect the computation time and speedup of the multi- DSP system.

  12. Design of high-speed data collecting system for pipeline magnetic flux leakage inspection

    NASA Astrophysics Data System (ADS)

    Qu, Weidong; Xu, Hongbing

    2013-03-01

    In the process of high-speed magnetic flux leakage inspection, a large amount of signals containing pipeline status, characteristics and defects need to be collected and transmitted. High sampling frequency, high real-time, high precision and intellectualization for data collecting are long-term trend. This paper proposed a new design method of high speed data collecting system. In the system, dual CPU structure is applied in main controller and the high-speed communication between DSP and MCU is realized through dual-port RAM technology. With the Dual CPU structure being applied, the measurement, control and the communication are charged by two CPUs respectively, which can improve the system adaptability. Dual-port RAM can raise communication efficiency by improving the parallel processing ability among different type of multiprocessors.

  13. A Web-Remote/Robotic/Scheduled Astronomical Data Acquisition System

    NASA Astrophysics Data System (ADS)

    Denny, Robert

    2011-03-01

    Traditionally, remote/robotic observatory operating systems have been custom made for each observatory. While data reduction pipelines need to be tailored for each investigation, the data acquisition process (especially for stare-mode optical images) is often quite similar across investigations. Since 1999, DC-3 Dreams has focused on providing and supporting a remote/robotic observatory operating system which can be adapted to a wide variety of physical hardware and optics while achieving the highest practical observing efficiency and safe/secure web browser user controls. ACP Expert consists of three main subsystems: (1) a robotic list-driven data acquisition engine which controls all aspects of the observatory, (2) a constraint-driven dispatch scheduler with a long-term database of requests, and (3) a built-in "zero admin" web server and dynamic web pages which provide a remote capability for immediate execution and monitoring as well as entry and monitoring of dispatch-scheduled observing requests. No remote desktop login is necessary for observing, thus keeping the system safe and consistent. All routine operation is via the web browser. A wide variety of telescope mounts, CCD imagers, guiding sensors, filter selectors, focusers, instrument-package rotators, weather sensors, and dome control systems are supported via the ASCOM standardized device driver architecture. The system is most commonly employed on commercial 1-meter and smaller observatories used by universities and advanced amateurs for both science and art. One current project, the AAVSO Photometric All-Sky Survey (APASS), uses ACP Expert to acquire large volumes of data in dispatch-scheduled mode. In its first 18 months of operation (North then South), 40,307 sky images were acquired in 117 photometric nights, resulting in 12,107,135 stars detected two or more times. These stars had measures in 5 filters. The northern station covered 754 fields (6446 square degrees) at least twice, the southern

  14. Development of a model of machine hand eye coordination and program specifications for a topological machine vision system

    NASA Technical Reports Server (NTRS)

    1972-01-01

    A unified approach to computer vision and manipulation is developed which is called choreographic vision. In the model, objects to be viewed by a projected robot in the Viking missions to Mars are seen as objects to be manipulated within choreographic contexts controlled by a multimoded remote, supervisory control system on Earth. A new theory of context relations is introduced as a basis for choreographic programming languages. A topological vision model is developed for recognizing objects by shape and contour. This model is integrated with a projected vision system consisting of a multiaperture image dissector TV camera and a ranging laser system. System program specifications integrate eye-hand coordination and topological vision functions and an aerospace multiprocessor implementation is described.

  15. An Efficient Solution Method for Multibody Systems with Loops Using Multiple Processors

    NASA Technical Reports Server (NTRS)

    Ghosh, Tushar K.; Nguyen, Luong A.; Quiocho, Leslie J.

    2015-01-01

    This paper describes a multibody dynamics algorithm formulated for parallel implementation on multiprocessor computing platforms using the divide-and-conquer approach. The system of interest is a general topology of rigid and elastic articulated bodies with or without loops. The algorithm divides the multibody system into a number of smaller sets of bodies in chain or tree structures, called "branches" at convenient joints called "connection points", and uses an Order-N (O (N)) approach to formulate the dynamics of each branch in terms of the unknown spatial connection forces. The equations of motion for the branches, leaving the connection forces as unknowns, are implemented in separate processors in parallel for computational efficiency, and the equations for all the unknown connection forces are synthesized and solved in one or several processors. The performances of two implementations of this divide-and-conquer algorithm in multiple processors are compared with an existing method implemented on a single processor.

  16. Post-game analysis: An initial experiment for heuristic-based resource management in concurrent systems

    NASA Technical Reports Server (NTRS)

    Yan, Jerry C.

    1987-01-01

    In concurrent systems, a major responsibility of the resource management system is to decide how the application program is to be mapped onto the multi-processor. Instead of using abstract program and machine models, a generate-and-test framework known as 'post-game analysis' that is based on data gathered during program execution is proposed. Each iteration consists of (1) (a simulation of) an execution of the program; (2) analysis of the data gathered; and (3) the proposal of a new mapping that would have a smaller execution time. These heuristics are applied to predict execution time changes in response to small perturbations applied to the current mapping. An initial experiment was carried out using simple strategies on 'pipeline-like' applications. The results obtained from four simple strategies demonstrated that for this kind of application, even simple strategies can produce acceptable speed-up with a small number of iterations.

  17. Implementation of multi-channel electronics system for astrophysical reaction studies at ORNL

    NASA Astrophysics Data System (ADS)

    Ahn, S. H.; Jones, K. L.; Matos, M.; Bardayan, D. W.; Chae, K. Y.; Smith, M. S.; Varner, R. J.; Elson, J. M.; Famiano, M. A.

    2010-11-01

    The development of large area, high-granularity silicon detector arrays has created opportunities to study transfer reactions in inverse kinematics with low-intensity radioactive beams. We are developing a new detector array comprised of 24 double-sided silicon strip detectors that will allow measurements with lower thresholds and better resolution than current detectors at ORNL. To instrument this new array, we are implementing ˜2000 channels of signal processing electronics based on application-specific integrated circuits (ASICs) designed at Washington University. The ASICs handle pulse shaping, timing, triggering, and digitization of 32 channels all on a single chip. In addition, a Real-Time Executive for Multiprocessor Systems (RTEMS) is used for a network communication between the electronics and data acquisition server. Details of the electronics setup and a status report on the devices will be presented. We will also discuss plans to utilize this system for experiments of transfer reactions using radioactive ion beams.

  18. Efficient parallel architecture for highly coupled real-time linear system applications

    NASA Technical Reports Server (NTRS)

    Carroll, Chester C.; Homaifar, Abdollah; Barua, Soumavo

    1988-01-01

    A systematic procedure is developed for exploiting the parallel constructs of computation in a highly coupled, linear system application. An overall top-down design approach is adopted. Differential equations governing the application under consideration are partitioned into subtasks on the basis of a data flow analysis. The interconnected task units constitute a task graph which has to be computed in every update interval. Multiprocessing concepts utilizing parallel integration algorithms are then applied for efficient task graph execution. A simple scheduling routine is developed to handle task allocation while in the multiprocessor mode. Results of simulation and scheduling are compared on the basis of standard performance indices. Processor timing diagrams are developed on the basis of program output accruing to an optimal set of processors. Basic architectural attributes for implementing the system are discussed together with suggestions for processing element design. Emphasis is placed on flexible architectures capable of accommodating widely varying application specifics.

  19. Using a scalable modeling and simulation framework to evaluate the benefits of intelligent transportation systems.

    SciTech Connect

    Ewing, T.; Tentner, A.

    2000-03-21

    A scalable, distributed modeling and simulation framework has been developed at Argonne National Laboratory to study Intelligent Transportation Systems. The framework can run on a single-processor workstation, or run distributed on a multiprocessor computer or network of workstations. The framework is modular and supports plug-in models, hardware, and live data sources. The initial set of models currently includes road network and traffic flow, probe and smart vehicles, traffic management centers, communications between vehicles and centers, in-vehicle navigation systems, roadway traffic advisories. The modeling and simulation capability has been used to examine proposed ITS concepts. Results are presented from modeling scenarios from the Advanced Driver and Vehicle Advisory Navigation Concept (ADVANCE) experimental program to demonstrate how the framework can be used to evaluate the benefits of ITS and to plan future ITS operational tests and deployment initiatives.

  20. Thiolactomycin-based β-ketoacyl-AcpM synthase A (KasA) inhibitors: fragment-based inhibitor discovery using transient one-dimensional nuclear overhauser effect NMR spectroscopy.

    PubMed

    Kapilashrami, Kanishk; Bommineni, Gopal R; Machutta, Carl A; Kim, Pilho; Lai, Cheng-Tsung; Simmerling, Carlos; Picart, Francis; Tonge, Peter J

    2013-03-01

    Thiolactomycin (TLM) is a natural product inhibitor of KasA, the β-ketoacyl synthase A from Mycobacterium tuberculosis. To improve the affinity of TLM for KasA, a series of TLM analogs have been synthesized based on interligand NOEs between TLM and a pantetheine analog when both are bound simultaneously to the enzyme. Kinetic binding data reveal that position 3 of the thiolactone ring is a suitable position for elaboration of the TLM scaffold, and the structure-activity relationship studies provide information on the molecular features that govern time-dependent inhibition in this enzyme system. These experiments also exemplify the utility of transient one-dimensional NOE spectroscopy for obtaining interligand NOEs compared with traditional steady state two-dimensional NOESY spectroscopy. PMID:23306195

  1. The MEGA (Muon decays into an Electron and a GAmma ray) hardware trigger system

    SciTech Connect

    Szymanski, J.J.; Amann, J.F.; Black, J.K.; Cooper, M.D.; Wright, S.C.; Crocker, J.; Sanders, H.

    1988-01-01

    The MEGA experiment is designed to search for the rare decay ..mu.. ..-->.. e ..gamma.. with a branching ratio sensitivity of /approximately/10/sup -13/. As is typical of rare-decay experiments, extensive, online filtering of the data is required for MEGA. The MEGA experiment uses a hardware pattern-recognition system based on Programmable Array Logic (PAL) devices. Additional events are eliminated in an online ACP system before data are written to tape. The MEGA trigger system is generally applicable where high-rate, short-propagation-delay trigger systems are required. This report contains an introduction to the MEGA experiment, a discussion of the MEGA hardware trigger system and a discussion of the system's measured performance. 4 refs., 3 figs.

  2. Flight Test of an Intelligent Flight-Control System

    NASA Technical Reports Server (NTRS)

    Davidson, Ron; Bosworth, John T.; Jacobson, Steven R.; Thomson, Michael Pl; Jorgensen, Charles C.

    2003-01-01

    The F-15 Advanced Controls Technology for Integrated Vehicles (ACTIVE) airplane (see figure) was the test bed for a flight test of an intelligent flight control system (IFCS). This IFCS utilizes a neural network to determine critical stability and control derivatives for a control law, the real-time gains of which are computed by an algorithm that solves the Riccati equation. These derivatives are also used to identify the parameters of a dynamic model of the airplane. The model is used in a model-following portion of the control law, in order to provide specific vehicle handling characteristics. The flight test of the IFCS marks the initiation of the Intelligent Flight Control System Advanced Concept Program (IFCS ACP), which is a collaboration between NASA and Boeing Phantom Works. The goals of the IFCS ACP are to (1) develop the concept of a flight-control system that uses neural-network technology to identify aircraft characteristics to provide optimal aircraft performance, (2) develop a self-training neural network to update estimates of aircraft properties in flight, and (3) demonstrate the aforementioned concepts on the F-15 ACTIVE airplane in flight. The activities of the initial IFCS ACP were divided into three Phases, each devoted to the attainment of a different objective. The objective of Phase I was to develop a pre-trained neural network to store and recall the wind-tunnel-based stability and control derivatives of the vehicle. The objective of Phase II was to develop a neural network that can learn how to adjust the stability and control derivatives to account for failures or modeling deficiencies. The objective of Phase III was to develop a flight control system that uses the neural network outputs as a basis for controlling the aircraft. The flight test of the IFCS was performed in stages. In the first stage, the Phase I version of the pre-trained neural network was flown in a passive mode. The neural network software was running using flight data

  3. Advanced data management system architectures testbed

    NASA Technical Reports Server (NTRS)

    Grant, Terry

    1990-01-01

    The objective of the Architecture and Tools Testbed is to provide a working, experimental focus to the evolving automation applications for the Space Station Freedom data management system. Emphasis is on defining and refining real-world applications including the following: the validation of user needs; understanding system requirements and capabilities; and extending capabilities. The approach is to provide an open, distributed system of high performance workstations representing both the standard data processors and networks and advanced RISC-based processors and multiprocessor systems. The system provides a base from which to develop and evaluate new performance and risk management concepts and for sharing the results. Participants are given a common view of requirements and capability via: remote login to the testbed; standard, natural user interfaces to simulations and emulations; special attention to user manuals for all software tools; and E-mail communication. The testbed elements which instantiate the approach are briefly described including the workstations, the software simulation and monitoring tools, and performance and fault tolerance experiments.

  4. Performance of the Galley Parallel File System

    NASA Technical Reports Server (NTRS)

    Nieuwejaar, Nils; Kotz, David

    1996-01-01

    As the input/output (I/O) needs of parallel scientific applications increase, file systems for multiprocessors are being designed to provide applications with parallel access to multiple disks. Many parallel file systems present applications with a conventional Unix-like interface that allows the application to access multiple disks transparently. This interface conceals the parallism within the file system, which increases the ease of programmability, but makes it difficult or impossible for sophisticated programmers and libraries to use knowledge about their I/O needs to exploit that parallelism. Furthermore, most current parallel file systems are optimized for a different workload than they are being asked to support. We introduce Galley, a new parallel file system that is intended to efficiently support realistic parallel workloads. Initial experiments, reported in this paper, indicate that Galley is capable of providing high-performance 1/O to applications the applications that rely on them. In Section 3 we describe that access data in patterns that have been observed to be common.

  5. Memory System Technologies for Future High-End Computing Systems

    SciTech Connect

    McKee, S A; de Supinski, B R; Mueller, F; Tyson, G S

    2003-05-16

    Our ability to solve Grand Challenge Problems in computing hinges on the development of reliable and efficient High-End Computing systems. Unfortunately, the increasing gap between memory and processor speeds remains one of the major bottlenecks in modern architectures. Uniprocessor nodes still suffer, but symmetric multiprocessor nodes--where access to physical memory is shared among all processors--are among the hardest hit. In the latter case, the memory system must juggle multiple working sets and maintain memory coherence, on top of simply responding to access requests. To illustrate the severity of the current situation, consider two important examples: even the high-performance parallel supercomputers in use at Department of Energy National labs observe single-processor utilization rates as low as 5%, and transaction processing commercial workloads see utilizations of at most about 33%. A wealth of research demonstrates that traditional memory systems are incapable of bridging the processor/memory performance gap, and the problem continues to grow. The success of future High-End Computing platforms therefore depends on our developing hardware and software technologies to dramatically relieve the memory bottleneck. In order to take better advantage of the tremendous computing power of modern microprocessors and future High-End systems, we consider it crucial to develop the hardware for intelligent, adaptable memory systems; the middleware and OS modifications to manage them; and the compiler technology and performance tools to exploit them. Taken together, these will provide the foundations for meeting the requirements of future generations of performance-critical, parallel systems based on either uniprocessor or SMP nodes (including PIM organizations). We feel that such solutions should not be vendor-specific, but should be sufficiently general and adaptable such that the technologies could be leveraged by any commercial vendor of High-End Computing systems

  6. Numerical Study of a System of Long Josephson Junctions with Inductive and Capacitive Couplings

    NASA Astrophysics Data System (ADS)

    Rahmonov, I. R.; Shukrinov, Yu. M.; Plecenik, A.; Zemlyanaya, E. V.; Bashashin, M. V.

    2016-02-01

    The phase dynamics of the stacked long Josephson junctions is investigated taking into account the inductive and capacitive couplings between junctions and the diffusion current. The simulation of the current-voltage characteristics is based on the numerical solution of a system of nonlinear partial differential equations by a fourth order Runge-Kutta method and finite-difference approximation. A parallel implementation is based on the MPI technique. The effectiveness of the MPI/C++ code is confirmed by calculations on the multi-processor cluster CICC (LIT JINR, Dubna). We demonstrate the appearance of the charge traveling wave (CTW) at the boundary of the zero field step. Based on this fact, we conclude that the CTW and the fluxons coexist.

  7. Design and Implementation of a Threaded Search Engine for Tour Recommendation Systems

    NASA Astrophysics Data System (ADS)

    Lee, Junghoon; Park, Gyung-Leen; Ko, Jin-Hee; Shin, In-Hye; Kang, Mikyung

    This paper implements a threaded scan engine for the O(n!) search space and measures its performance, aiming at providing a responsive tour recommendation and scheduling service. As a preliminary step of integrating POI ontology, mobile object database, and personalization profile for the development of new vehicular telematics services, this implementation can give a useful guideline to design a challenging and computation-intensive vehicular telematics service. The implemented engine allocates the subtree to the respective threads and makes them run concurrently exploiting the primitives provided by the operating system and the underlying multiprocessor architecture. It also makes it easy to add a variety of constraints, for example, the search tree is pruned if the cost of partial allocation already exceeds the current best. The performance measurement result shows that the service can run even in the low-power telematics device when the number of destinations does not exceed 15, with an appropriate constraint processing.

  8. Distributed computing feasibility in a non-dedicated homogeneous distributed system

    NASA Technical Reports Server (NTRS)

    Leutenegger, Scott T.; Sun, Xian-He

    1993-01-01

    The low cost and availability of clusters of workstations have lead researchers to re-explore distributed computing using independent workstations. This approach may provide better cost/performance than tightly coupled multiprocessors. In practice, this approach often utilizes wasted cycles to run parallel jobs. The feasibility of such a non-dedicated parallel processing environment assuming workstation processes have preemptive priority over parallel tasks is addressed. An analytical model is developed to predict parallel job response times. Our model provides insight into how significantly workstation owner interference degrades parallel program performance. A new term task ratio, which relates the parallel task demand to the mean service demand of nonparallel workstation processes, is introduced. It was proposed that task ratio is a useful metric for determining how large the demand of a parallel applications must be in order to make efficient use of a non-dedicated distributed system.

  9. 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.

  10. Acp. Best practice no 160. Renal biopsy specimens.

    PubMed

    Furness, P N

    2000-06-01

    Taking a kidney biopsy is not a trivial procedure. The sample is almost invariably smaller than the pathologist would like. Investigation usually requires division into even smaller samples to permit the application of specialist techniques. In some cases the biopsy is taken not for diagnosis, but to assess the extent of tissue damage. The clinical need is sometimes extremely urgent. These features all underline the crucial importance of collaboration between pathologist and nephrologist if maximum benefit is to be obtained from such very small samples. Consequently, in deciding what to do with a renal biopsy, flexibility and thought are required rather than a single prescribed list of procedures. This article, written after extensive international consultation, represents an attempt to define current best practice in the laboratory handling of renal biopsy specimens, while not neglecting the need to tailor processing to the individual needs of each case. PMID:10911800

  11. Science Advisory Panel Meets to Discuss HLB/ACP

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A group of scientists met in December 2013 as a Science Advisory Panel (SAP) to listen to presentations by the Citrus Research Board (CRB) and the California Department of Food and Agriculture (CDFA) and to respond to questions posed by CDFA personnel and the general public. The goal of the meeting ...

  12. 26 CFR 1.401(m)-2 - ACP test.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... determined under § 1.401(m)-2(b)(2)(iv) (as it appeared in the April 1, 2007, edition of 26 CFR part 1). (E... determined under § 1.401(m)-2(b)(2)(vi) (as it appeared in the April 1, 2007, edition of 26 CFR Part 1)....

  13. Nuclear Science Symposium, 31st and Symposium on Nuclear Power Systems, 16th, Orlando, FL, October 31-November 2, 1984, Proceedings

    NASA Technical Reports Server (NTRS)

    Biggerstaff, J. A. (Editor)

    1985-01-01

    Topics related to physics instrumentation are discussed, taking into account cryostat and electronic development associated with multidetector spectrometer systems, the influence of materials and counting-rate effects on He-3 neutron spectrometry, a data acquisition system for time-resolved muscle experiments, and a sensitive null detector for precise measurements of integral linearity. Other subjects explored are concerned with space instrumentation, computer applications, detectors, instrumentation for high energy physics, instrumentation for nuclear medicine, environmental monitoring and health physics instrumentation, nuclear safeguards and reactor instrumentation, and a 1984 symposium on nuclear power systems. Attention is given to the application of multiprocessors to scientific problems, a large-scale computer facility for computational aerodynamics, a single-board 32-bit computer for the Fastbus, the integration of detector arrays and readout electronics on a single chip, and three-dimensional Monte Carlo simulation of the electron avalanche in a proportional counter.

  14. Concurrent algorithms for a mobile robot vision system

    SciTech Connect

    Jones, J.P.; Mann, R.C.

    1988-01-01

    The application of computer vision to mobile robots has generally been hampered by insufficient on-board computing power. The advent of VLSI-based general purpose concurrent multiprocessor systems promises to give mobile robots an increasing amount of on-board computing capability, and to allow computation intensive data analysis to be performed without high-bandwidth communication with a remote system. This paper describes the integration of robot vision algorithms on a 3-dimensional hypercube system on-board a mobile robot developed at Oak Ridge National Laboratory. The vision system is interfaced to navigation and robot control software, enabling the robot to maneuver in a laboratory environment, to find a known object of interest and to recognize the object's status based on visual sensing. We first present the robot system architecture and the principles followed in the vision system implementation. We then provide some benchmark timings for low-level image processing routines, describe a concurrent algorithm with load balancing for the Hough transform, a new algorithm for binary component labeling, and an algorithm for the concurrent extraction of region features from labeled images. This system analyzes a scene in less than 5 seconds and has proven to be a valuable experimental tool for research in mobile autonomous robots. 9 refs., 1 fig., 3 tabs.

  15. The Dark Energy Camera Data Acquisition and Control System

    NASA Astrophysics Data System (ADS)

    Buckley-Geer, Elizabeth J.; Annis, J.; Bonati, M.; Eiting, J.; Elliot, A.; Haney, M.; Hanlon, W.; Honscheid, K.; Karliner, I.; Kuehn, K. W.; Kuhlmann, S. E.; Marshall, S.; Roodman, A. J.; Schalk, T.; Schumacher, G.; Thaler, J.; Wester, W.

    2011-01-01

    The Dark Energy Camera (DECam) data acquisition and control system is called the Survey Image System Process Integration (SISPI). Implemented as a distributed multi-processor system, SISPI consists of a set of processes that will coordinate and perform image acquisition and deliver images to the data management system for processing. Separate processes for instrument control, image building and analysis, image acquisition and observatory control are built on top of an infrastructure layer that provides message passing and communications. Additional system components include a flexible configuration system and the facility database. The command protocol is implemented in Python using a client-server design pattern derived from the SML and SCLN communications software developed at CTIO. A publish-subscribe model has been added to support the distribution of telemetry data and alarm messages. The design of the graphical user interfaces follows the Model-View-Controller approach to distinguish between the actual information and the graphical representation of the data. We will present the software architecture of the SISPI system and report on the current status of the project.

  16. ETHERNET BASED EMBEDDED SYSTEM FOR FEL DIAGNOSTICS AND CONTROLS

    SciTech Connect

    Jianxun Yan; Daniel Sexton; Steven Moore; Albert Grippo; Kevin Jordan

    2006-10-24

    An Ethernet based embedded system has been developed to upgrade the Beam Viewer and Beam Position Monitor (BPM) systems within the free-electron laser (FEL) project at Jefferson Lab. The embedded microcontroller was mounted on the front-end I/O cards with software packages such as Experimental Physics and Industrial Control System (EPICS) and Real Time Executive for Multiprocessor System (RTEMS) running as an Input/Output Controller (IOC). By cross compiling with the EPICS, the RTEMS kernel, IOC device supports, and databases all of these can be downloaded into the microcontroller. The first version of the BPM electronics based on the embedded controller was built and is currently running in our FEL system. The new version of BPM that will use a Single Board IOC (SBIOC), which integrates with an Field Programming Gate Array (FPGA) and a ColdFire embedded microcontroller, is presently under development. The new system has the features of a low cost IOC, an open source real-time operating system, plug&play-like ease of installation and flexibility, and provides a much more localized solution.

  17. Overview of the CDF Run II data handling system

    NASA Astrophysics Data System (ADS)

    Buckley-Geer, L.; Lammel, S.; Leininger, M.; Watts, T.

    2001-10-01

    The Collider Detector at Fermilab (CDF) collaboration records and analyses proton-anti-proton interactions with a center-of-mass energy of 2 TeV at the Tevatron. During the next collider run the experiment expects to record about 1 PetaByte of data, an increase by more than an order of magnitude in data volume compared to the existing data of the experiment. This paper gives an overview of the new data handling system. The design builds upon successful strategies used in the past but eliminates shortcomings encountered with the old system. The core of the central analysis system will be a pool of over 20 TBytes of data disks. Logically behind this disk pool will be an automated tape library with a storage capacity to hold the full 1 PByte of Run II data. Multi-processor compute systems will be located around this storage pool to provide the required analysis power of over 3000 SPECint95. Desktop systems will be integrated into the analysis system via a shared login area and user authentication. The data handling software falls into four categories: software to manage computing resources, software for the data disks and for the mass storage subsystem, software to organize and manage the meta-data information, and the I/O modules in the analysis framework for accessing data.

  18. The readout and control system of the Dark Energy Camera

    NASA Astrophysics Data System (ADS)

    Honscheid, Klaus; Elliott, Ann; Annis, James; Bonati, Marco; Buckley-Geer, Elizabeth; Castander, Francisco; daCosta, Luiz; Fausti, Angelo; Karliner, Inga; Kuhlmann, Steve; Neilsen, Eric; Patton, Kenneth; Reil, Kevin; Roodman, Aaron; Thaler, Jon; Serrano, Santiago; Soares Santos, Marcelle; Suchyta, Eric

    2012-09-01

    The Dark Energy Camera (DECam) is a new 520 Mega Pixel CCD camera with a 3 square degree field of view designed for the Dark Energy Survey (DES). DES is a high precision, multi-bandpass, photometric survey of 5000 square degrees of the southern sky. DECam is currently being installed at the prime focus of the Blanco 4-m telescope at the Cerro- Tololo International Observatory (CTIO). In this paper we describe SISPI, the data acquisition and control system of the Dark Energy Camera. SISPI is implemented as a distributed multi-processor system with a software architecture based on the Client-Server and Publish-Subscribe design patterns. The underlying message passing protocol is based on PYRO, a powerful distributed object technology system written entirely in Python. A distributed shared variable system was added to support exchange of telemetry data and other information between different components of the system. We discuss the SISPI infrastructure software, the image pipeline, the observer console and user interface architecture, image quality monitoring, the instrument control system, and the observation strategy tool.

  19. Parallel Computing Environments and Methods for Power Distribution System Simulation

    SciTech Connect

    Lu, Ning; Taylor, Zachary T.; Chassin, David P.; Guttromson, Ross T.; Studham, Scott S.

    2005-11-10

    The development of cost-effective high-performance parallel computing on multi-processor super computers makes it attractive to port excessively time consuming simulation software from personal computers (PC) to super computes. The power distribution system simulator (PDSS) takes a bottom-up approach and simulates load at appliance level, where detailed thermal models for appliances are used. This approach works well for a small power distribution system consisting of a few thousand appliances. When the number of appliances increases, the simulation uses up the PC memory and its run time increases to a point where the approach is no longer feasible to model a practical large power distribution system. This paper presents an effort made to port a PC-based power distribution system simulator (PDSS) to a 128-processor shared-memory super computer. The paper offers an overview of the parallel computing environment and a description of the modification made to the PDSS model. The performances of the PDSS running on a standalone PC and on the super computer are compared. Future research direction of utilizing parallel computing in the power distribution system simulation is also addressed.

  20. Arrangement techniques of proteins and cells using amorphous calcium phosphate nanofiber scaffolds

    NASA Astrophysics Data System (ADS)

    Nonoyama, Takayuki; Kinoshita, Takatoshi; Higuchi, Masahiro; Nagata, Kenji; Tanaka, Masayoshi; Kamada, Mari; Sato, Kimiyasu; Kato, Katsuya

    2012-12-01

    We demonstrate arrangement techniques of proteins and cells using an amorphous calcium phosphate (ACP) nanofiber scaffold. It is well known that protein andosteoblastic cell are preferably adsorbed onto ACP surface. The ACP nanofiber scaffold was prepared by calcium phosphate mineralization on a polypeptide monolayer-coated mica substrate, and ACP nanofibers were oriented unidirectionaly. In a protein system, the ACP nanofiber scaffold was soaked in a fluorescein isothiocyanate conjugated immunoglobulin G (IgG-FITC) aqueous solution. From fluorescence microscopic measurement, the adsorbed IgG-FITC was highly confined and arranged on the ACP nanofiber. In a cell system, a mouse osteoblast-like cell (MC3T3-E1) behavior on the ACP nanofiber scaffold was observed. The cell was elongated unidirectionaly, and its cytoskeletal shape showed high aspect ratio. These results are clearly different from an ACP bulk template or bare mica substrate, and the arrangement technique enable to fabricate a fine-tuned biomaterial template.