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Sample records for acp multiprocessor system

  1. Software for the ACP (Advanced Computer Program) multiprocessor system

    SciTech Connect

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

    1987-02-02

    Software has been developed for use with the Fermilab Advanced Computer Program (ACP) multiprocessor system. The software was designed to make a system of a hundred independent node processors as easy to use as a single, powerful CPU. Subroutines have been developed by which a user's host program can send data to and get results from the program running in each of his ACP node processors. Utility programs make it easy to compile and link host and node programs, to debug a node program on an ACP development system, and to submit a debugged program to an ACP production system.

  2. 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.

  3. Validation of multiprocessor systems

    NASA Technical Reports Server (NTRS)

    Siewiorek, D. P.; Segall, Z.; Kong, T.

    1982-01-01

    Experiments that can be used to validate fault free performance of multiprocessor systems in aerospace systems integrating flight controls and avionics are discussed. Engineering prototypes for two fault tolerant multiprocessors are tested.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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)

  10. 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.

  11. 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.

  12. Distributed parallel messaging for multiprocessor systems

    SciTech Connect

    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.

  13. Using multiprocessor systems in scientific applications

    SciTech Connect

    Maples, C.; Logan, D.

    1985-08-01

    The MIDAS multiprocessor system is a multi-level, hierarchial structure developed at the Advanced Computer Architecture Laboratory of the University of California's Lawrence Berkeley Laboratory. A two-stage, 11-processor system has been operational for about 18 months. It has been employed to investigate techniques for decomposing a variety of problems and algorithms into a parallel processor environment. The performance results for a number of different applications are discussed. These include scientific data analysis, Monte Carlo calculations, solutions to partial differential calculations (using finitedifference methods), and problems in accelerator design. Language extensions and programming techniques for the data-flow architecture is also presented.

  14. 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.

  15. 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.

  16. SIERA: A Multiprocessor System For Robotics

    NASA Astrophysics Data System (ADS)

    Kazanzides, Peter; Wasti, Hamid; Wolovich, W. A.

    1987-03-01

    This paper describes SIERA (System for Implementing and Evaluating Robotic Algorithms), which has been developed at the Laboratory for Engineering Man/Machine Systems (LEMS) at Brown University. SIERA was created to satisfy the requirement for a multiprocessor-based development system flexible enough to be used for research into new robotic algorithms, especially those that utilize externally sensed information, such as vision and force. A multiprocessor architecture has been developed that incorporates a tightly coupled bus-based system for real-time servoing and a loosely coupled point-to-point network for less time-critical operations. SIERA is capable of controlling many types of commercially available robots since all input and output is done via general-purpose I/O boards. Suitably constructed robot interface boards are used to condition all feedback signals and to amplify the control outputs to the proper drive levels. We have constructed robot interface boards for the IBM 7565 and PUMA 560 manipulators in LEMS, and have controlled both robots using SIERA. The operating system used for SIERA has been designed to provide maximum flexibility in implementing new robotic algorithms. The concept of programming levels has been introduced to classify the different ways SIERA can be utilized ¬â€?for simple robot control, for robotics research, and for system enhancements. The main benefit of SIERA is that it is now possible to experimentally implement and evaluate a variety of algorithms in areas such as compliant control, visual servoing, and inverse kinematics.

  17. 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.

  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. Design of software for distributed/multiprocessor systems

    SciTech Connect

    Mckelvey, T.R.; Agrawal, D.P.

    1982-01-01

    Software design methodologies for distributed/multiprocessor systems are investigated. Parallelism and multitasking are considered as key issues in the design process. Petri-Nets and precedence graphs are presented as techniques for the modeling of a problem for implementation on a computer system. Techniques using the Petri-Net and precedence graph to decompose the problem model into subsets that may be executed on a distributed/multiprocessor system are presented. These techniques offer a systematic design methodology for the design of distributed/multiprocessor system software. 8 references.

  20. 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.

  1. Efficient hierarchical interconnection for multiprocessor systems

    NASA Technical Reports Server (NTRS)

    Wei, Sizheng; Levy, Saul

    1992-01-01

    The authors present a novel approach to the design of a class of hierarchical interconnection networks for multiprocessor systems. This approach, based on an architecture providing separate networks for each level, gives a general and flexible way to construct efficient hierarchical networks. The performance and cost-effectiveness of the resulting networks are analyzed and compared in detail, using both unbuffered and buffered network models. It is shown that, if the design parameters are determined based on the degree of locality, the cost-effectiveness of a hierarchical network can be significantly improved. In addition, the authors investigate how to construct a cost-effectiveness hierarchical network by determining appropriate design parameters. Two associated algorithms are developed for this purpose.

  2. 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.

  3. 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.

  4. 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.

  5. Multitasking runtime systems for the Cedar Multiprocessor

    SciTech Connect

    Guzzi, M.D.

    1986-07-01

    The programming of a MIMD machine is more complex than for SISD and SIMD machines. The multiple computational resources of the machine must be made available to the programming language compiler and to the programmer so that multitasking programs may be written. This thesis will explore the additional complexity of programming a MIMD machine, the Cedar Multiprocessor specifically, and the multitasking runtime system necessary to provide multitasking resources to the user. First, the problem will be well defined: the Cedar machine, its operating system, the programming language, and multitasking concepts will be described. Second, a solution to the problem, called macrotasking, will be proposed. This solution provides multitasking facilities to the programmer at a very coarse level with many visible machine dependencies. Third, an alternate solution, called microtasking, will be proposed. This solution provides multitasking facilities of a much finer grain. This solution does not depend so rigidly on the specific architecture of the machine. Finally, the two solutions will be compared for effectiveness. 12 refs., 16 figs.

  6. 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.

  7. 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.

  8. Dynamically Reconfigurable Multiprocessor System For Scene Segmentation In Histopathology

    NASA Astrophysics Data System (ADS)

    Shoemaker, Richard L.; Stucky, Oliver; Maenner, Reinhard; Thompson, Deborah B.; Griswold, W. G.; Bartels, Peter H.

    1989-06-01

    The Heidelberg Polyp multiprocessor and its application to scene segmentation problems in histopathology is discussed, including ways in which the architecture can be utilized to support expert system-guided scene segmentation software, the system's current performance, and some major improvements currently being made to the system.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. Application programming for MIDAS, a multiprocessor system

    SciTech Connect

    Logan, D.; Maples, C.; Rathbun, W.; Weaver, D.

    1983-10-01

    All programs currently running on serial computers require some degree of modification when moved to parallel processors. This is true whether the architectural parallelism is manifested at the instruction level, such as in array processors or the CRAY, or achieved via multiple processors, as is the case in the MIDAS system. In either case the degree to which the program exploits the architecture can significantly affect the processing speed. Some guidelines for application programming for the MIDAS system are discussed. Important programming considerations include the separation of serial and parallel elements of a program (such as program initialization), data input mechanisms (including hardware preprocessing), and output mechanisms. Comparisons of code written for standard serial machines to the same code modified for MIDAS are examined and performance results discussed.

  14. 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.

  15. 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.

  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. 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.

  19. Efficient implementation techniques for gracefully degradable multiprocessor systems

    SciTech Connect

    Liu, J.C.; Shin, K.G.

    1995-04-01

    We propose the dynamic reconfiguration network (DRN) and a monitoring-at-transmission (MAT) bus to support dynamic reconfiguration of an N-modular redundancy (NMR) multiprocessor system. In the reconfiguration process, a maximal number of processor triads are guaranteed to be formed on each processor cluster, thus supporting gracefully degradable operations. This is made possible by dynamically routing the control and clock signals of processors on the DRN so as to synchronize fault-free processors. The MAT bus is an efficient way to implement a triple modular redundant (TMR) pipeline voter (PV), which is a special case of the voting network proposed previously. Extensive experimental results have shown to support our design concept, and the performance of different cache memory organizations is evaluated through an analytic model. 22 refs.

  20. Multiprocessor system on chip with shared memory using crossbar topology

    NASA Astrophysics Data System (ADS)

    de Macedo Mourelle, Luiza; Nedjah, Nadia; Gonçalves Pessanha, Fábio

    2015-01-01

    Multiprocessor system on chip offers a set of processors, embedded in one single chip. A parallel application can, then, be scheduled to each processor, in order to accelerate its execution, using either shared memory or message passing for exchanging data. In this case, the use of a shared bus is no longer a viable solution, due to its high contention. In order to allow for non-blocking parallelism, we implemented the interconnection network based on the crossbar topology. In this kind of interconnection, processors have full access to their own memory module simultaneously, besides been able to address the whole memory. One processor accesses the memory module of another processor only when it needs to retrieve data generated by the latter. This paper presents the specification and modelling of an interconnection network based on the crossbar topology. The aim of this work is to investigate the performance characteristics of a parallel application running on this platform.

  1. 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.

  2. 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.

  3. Hawk: An operating system kernel for a real-time embedded multiprocessor. [SANDAC V

    SciTech Connect

    Holmes, V.P.; Harris, D.L.; Piorkowksi, K.W.; Davidson, G.S.

    1987-01-01

    The Hawk operating system is a real-time multitasking environment for the SANDAC V, a Motorola 68020-based multiprocessor. This system is presented with respect to general target applications, the underlying multiprocessor hardware and the programming abstractions useful for real-time problems. The design principles, system features and user interface are discussed, together with an evaluation of the success of the Hawk effort and its usefulness in fielded application.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. Cache-based error recovery for shared memory multiprocessor systems

    NASA Technical Reports Server (NTRS)

    Wu, Kun-Lung; Fuchs, W. Kent; Patel, Janak H.

    1989-01-01

    A multiprocessor cache-based checkpointing and recovery scheme for of recovering from transient processor errors in a shared-memory multiprocessor with private caches is presented. New implementation techniques that use checkpoint identifiers and recovery stacks to reduce performance degradation in processor utilization during normal execution are examined. This cache-based checkpointing technique prevents rollback propagation, provides for rapid recovery, and can be integrated into standard cache coherence protocols. An analytical model is used to estimate the relative performance of the scheme during normal execution. Extensions that take error latency into account are presented.

  9. Reliability Inherent in Heterogeneous Multiprocessor Systems and Task Scheduling for Ameliorating Their Reliability

    NASA Astrophysics Data System (ADS)

    Sugihara, Makoto

    Utilizing a heterogeneous multiprocessor system has become a popular design paradigm to build an embedded system at a cheap cost within short development time. A reliability issue for embedded systems, which is vulnerability to single event upsets (SEUs), has become a matter of concern as technology proceeds. This paper discusses reliability inherent in heterogeneous multiprocessors and proposes task scheduling for minimizing SEU vulnerability of them. This paper experimentally shows that increasing performance of a CPU core deteriorates its reliability. Based on the experimental observation, we propose task scheduling for reducing SEU vulnerability of a heterogeneous multiprocessor system. The experimental results demonstrate that our task scheduling technique can reduce much of SEU vulnerability under real-time constraints.

  10. 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.

  11. Modeling techniques in a parallelizing compiler for the B-HIVE multiprocessor system

    NASA Technical Reports Server (NTRS)

    Kim, Sukil; Agrawal, Dharma P.; Mauney, Jon; Leu, Ja-Song

    1989-01-01

    The parallelizing compiler for the B-HIVE loosely-coupled multiprocessor system uses a medium grain model to minimize the communication overhead. A medium grain model is shown to be an optimum way of merging fine grain operations into parallel tasks such that the parallelism obtained at the grain level is retained and communication overhead is decreased. A new communication model is introduced in this paper, allowing additional overlap between computation and communication. Simulation results indicate that the medium grain communication model shows promise for automatic parallelization for a loosely-coupled multiprocessor system.

  12. Image-Data-Driven Dynamically-Reconfigurable Multiprocessor System In Automated Histopathology

    NASA Astrophysics Data System (ADS)

    Shoemaker, R. L.; Bartels, P. H.; Bartels, H.; Griswold, W. G.; Hillman, D.; Maenner, R.

    1986-04-01

    The diagnostic evaluation of biomedical imagery by computer presents a massive data processing problem that may be effectively handled by multiprocessor computer systems such as the Heidelberg Polyp. A hardware and software configuration of the Polyp is described that can run as a data-driven system directed by a knowledge data base for efficient image analysis.

  13. Implementation of multigrid methods for solving Navier-Stokes equations on a multiprocessor system

    NASA Technical Reports Server (NTRS)

    Naik, Vijay K.; Taasan, Shlomo

    1987-01-01

    Presented are schemes for implementing multigrid algorithms on message based MIMD multiprocessor systems. To address the various issues involved, a nontrivial problem of solving the 2-D incompressible Navier-Stokes equations is considered as the model problem. Three different multigrid algorithms are considered. Results from implementing these algorithms on an Intel iPSC are presented.

  14. Multiprocessor data acquisition system for high event rates at the Heidelberg/Darmstadt crystal ball

    SciTech Connect

    Ender, C.; Manner, R.; Bauer, P. . Physikalisches Inst.)

    1989-10-01

    The Heidelberg/Darmstadt crystal ball detector uses a distributed data acquisition system consisting of a Fastbus/CAMAC front-end, the Heidelberg Polyp multiprocessor system with 30 processor modules, and an online VAX. For this heterogeneous multicomputer system a distributed real-time operating system was developed. The distributed computer system allows for event rates up to 2 x 10/sup 4/ events/s. It is managed user transparently and fault tolerantly.

  15. 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.

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. Modeling and measuring multiprogramming and system overheads on a shared-memory multiprocessor - Case study

    NASA Technical Reports Server (NTRS)

    Dimpsey, Robert T.; Iyer, Ravi K.

    1991-01-01

    The present discussion of methods for quantifying multiprogramming (MP) overhead on a computer system illustrates two such techniques, respectively for quantifying MP overheads' lower bound and determining the MP overload of real workloads, in light of the percentage of parallel processing time that is consumed by MP overhead on Alliant multiprocessors. Kernel lock spinning is found to be a major factor in MP overhead, which accounts for more than half of total system overhead. It is noted that parallel environments' MP overhead is not statistically dependent on the number of parallel jobs undergoing multiprogramming.

  1. A VME multiprocessor data acquisition system combining a UNIX workstation and real-time microprocessors

    SciTech Connect

    Barome, N.; Bossu, Y.; Douet, R.; Harroch, H.; Tran-Khanh, T. )

    1990-08-01

    A data acquisition system combining a UNIX workstation and one or several real-time microprocessors has been designed and built for the Tandem accelerator at IPN. The hardware and software options chosen for reading, processing, storing, and displaying real-time experimental data are detailed. The fixed components of the hardware architecture are the VME bus for data processing and the CMAC system for transferring digital data. A multitask multiprocessor software based on shared memory and message passing has been developed around a mixed UNIX/pSOS kernel.

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

    SciTech Connect

    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.

  3. 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.

  4. Advanced large-scale and high-speed multiprocessor system for scientific applications CRAY X-MP-4 series

    SciTech Connect

    Chen, S.S.

    1986-06-01

    This paper offers an overview of CRAY X-MP-4 system, a general purpose multiprocessor system for multitasking applications. Diagrams illustrate the overall system organization, data flow, vector computations and vector loop families benchmark timings. The CRAY X-MP-4 has scalar and vector applications.

  5. 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

  6. 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

  7. 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.

  8. Operating system considerations in the multiprocessor MIDAS environment

    SciTech Connect

    Weaver, D.; Maples, C.; Meng, J.; Rathbun, W.

    1983-10-01

    The operating system for MIDAS provides interfaces for custom hardware, debugging facilities, and run time support. The MIDAS architecture uses various specialized hardware devices for controlling the multiple processors and to achieve high I/O throughput. The operating system interfaces with the custom hardware for diagnostics, problem setup, and loading the processors with user code. After the code is loaded, a debugging facility may be used to examine or modify the program in any of the processors, or all the processors simultaneously. During execution of the code, the operating system monitors the processors for exceptional conditions, detects hardware failures, and gathers statistics on performance. This performance information includes histograms depicting instruction execution frequency and analysis of data flow.

  9. 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.

  10. Support system for a 1750A VHSIC multiprocessor

    NASA Technical Reports Server (NTRS)

    Ruggles, Stephen L.

    1990-01-01

    A design approach for a support system or test station necessary to functionally operate a very high-speed integrated circuit (VHSIC) microprocessor brassboard is presented. Major subsystems which make up the support are the following: (1) power supply unit; (2) temperature controller unit; (3) input/output module; and (4) mechanical test fixture. Theoretical analyses and experimental techniques were utilized to design and implement the power and temperature requirements for the VHSIC processor. A functional description of the input/output module and test fixture is discussed. The support system provides the means to evaluate and functionally test a VHSIC microprocessor.

  11. 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.

  12. 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.

  13. Delayed information flow effect in economy systems. An ACP model study

    NASA Astrophysics Data System (ADS)

    Miśkiewicz, Janusz; Ausloos, M.

    2007-08-01

    Applying any strategy requires some knowledge about the past state of the system. Unfortunately in the case of economy, collecting information is a difficult, expensive and time consuming process. Therefore, the information about the system is usually known only at the end of some well-defined intervals, e.g. through company, national bank inflation data and Gross Domestic Product (GDP) reports, etc. They describe a (market) situation in the past. The time delay is specific to the market branch. It can be very short (e.g. stock market offer is updated every minute or so and this information is quasi-immediately available) or long, like months in the case of agricultural markets, when the decisions are taken based on the results from the previous harvest. The analysis of the information flow delay can be based on the Ausloos-Clippe-Pękalski (ACP) model of spatial evolution of economic systems. The entities can move on a (square) lattice and when meeting take one of the two following decisions: merge or create a new entity. The decision is based on the system state, which is known with some time delay. The effect of system's feedback is hereby investigated. We consider the case of company distribution evolution in a heterogeneous field. The information flow time delay implies different final states, including cycles; it is like a control parameter in a logistic map.

  14. 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.

  15. Dynamic modelling and estimation of the error due to asynchronism in a redundant asynchronous multiprocessor system

    NASA Technical Reports Server (NTRS)

    Huynh, Loc C.; Duval, R. W.

    1986-01-01

    The use of Redundant Asynchronous Multiprocessor System to achieve ultrareliable Fault Tolerant Control Systems shows great promise. The development has been hampered by the inability to determine whether differences in the outputs of redundant CPU's are due to failures or to accrued error built up by slight differences in CPU clock intervals. This study derives an analytical dynamic model of the difference between redundant CPU's due to differences in their clock intervals and uses this model with on-line parameter identification to idenitify the differences in the clock intervals. The ability of this methodology to accurately track errors due to asynchronisity generate an error signal with the effect of asynchronisity removed and this signal may be used to detect and isolate actual system failures.

  16. 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.

  17. 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.

  18. Multiprocessor data acquisition system for a 256x256-pixel infrared camera

    NASA Astrophysics Data System (ADS)

    Rodriguez-Ramos, Luis F.; Rodriguez-Mora, A.; Sosa, Nicolas A.; Diaz, Jose J.; Joven-Alvarez, Enrique

    1993-04-01

    The Department of Detectors of the Instituto de Astrofisica de Canarias, Spain is developing a data acquisition system (DAS) for an infrared camera based in a 256 X 256 InSb detector. The camera is going to work from 1 to 5 microns wavelength, with a scale on the sky of 0.5 arcsec per pixel, and will be installed as a common user instrument at the Carlos Sanchez Telescope in the Observatorio del Teide (Canary Island, Spain). A multiprocessor architecture has been chosen for the DAS, due to the very tight requirements on real time processing, and high speed storage capability (20 images per second readout rate, 2 images per second storage rate). The complete system is split into two main parts, the front end electronics and the user workstation. They are interconnected through an ETHERNET link.

  19. Scheduling for energy and reliability management on multiprocessor real-time systems

    NASA Astrophysics Data System (ADS)

    Qi, Xuan

    Scheduling algorithms for multiprocessor real-time systems have been studied for years with many well-recognized algorithms proposed. However, it is still an evolving research area and many problems remain open due to their intrinsic complexities. With the emergence of multicore processors, it is necessary to re-investigate the scheduling problems and design/develop efficient algorithms for better system utilization, low scheduling overhead, high energy efficiency, and better system reliability. Focusing cluster schedulings with optimal global schedulers, we study the utilization bound and scheduling overhead for a class of cluster-optimal schedulers. Then, taking energy/power consumption into consideration, we developed energy-efficient scheduling algorithms for real-time systems, especially for the proliferating embedded systems with limited energy budget. As the commonly deployed energy-saving technique (e.g. dynamic voltage frequency scaling (DVFS)) will significantly affect system reliability, we study schedulers that have intelligent mechanisms to recuperate system reliability to satisfy the quality assurance requirements. Extensive simulation is conducted to evaluate the performance of the proposed algorithms on reduction of scheduling overhead, energy saving, and reliability improvement. The simulation results show that the proposed reliability-aware power management schemes could preserve the system reliability while still achieving substantial energy saving.

  20. 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.

  1. 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.

  2. 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).

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. Multiprocessor memory contention

    SciTech Connect

    Knadler, C.E. Jr.

    1989-01-01

    Caches are frequently incorporated in processor architectures to increase the effective memory speed and to reduce memory contention. However, task switches and the coherency problems of large n-way, mainframe-class multiprocessors lessen the effectiveness of cache architectures for general-purpose applications. A proposed alternative approach is to increase the effective memory bandwidth and decrease memory-access delays through instruction prefetch, operand buffering, highly interleave memory, and multiple-word width processor-memory data paths. This approach was evaluated by comparing cache and noncache system performance, using discrete-event simulation. Since the performance of a multiprocessor architecture is a function of its operating environment was well as its design, the system workload was defined. General-purpose applications, running under multitasking operating systems, were characterized with respect to addressing patterns, paging rates, and frequency of input/output operations. The proposed noncache architecture was found to have performance comparable to that of the cache architectures and obviated then need to solve the cache coherency problem.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. Multiprocessor sort-merge join algorithm for relational data bases

    SciTech Connect

    Thompson, W.C. III; Ries, D.R.

    1981-01-01

    Using multiprocessor systems for rapid processing of relational operations in relational databases is currently a topic of some interest. This paper presents a new multiprocessor algorithm for merge joins of relations. Considerable gains in speed in comparison with existing algorithms are exhibited by this algorithm.

  15. Multiprocessor sort-merge join algorithm for relational databases

    SciTech Connect

    Thompson, W.C. III; Ries, D.R.

    1981-12-01

    Using multiprocessor systems for rapid processing of relational operations in relational databases is currently a topic of some interest. This paper presents a new multiprocessor algorithm for merge joins of relations. Considerable gains in speed in comparison with existing algorithms are exhibited by this algorithm.

  16. 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.

  17. Compiler-directed cache management in multiprocessors

    NASA Technical Reports Server (NTRS)

    Cheong, Hoichi; Veidenbaum, Alexander V.

    1990-01-01

    The necessity of finding alternatives to hardware-based cache coherence strategies for large-scale multiprocessor systems is discussed. Three different software-based strategies sharing the same goals and general approach are presented. They consist of a simple invalidation approach, a fast selective invalidation scheme, and a version control scheme. The strategies are suitable for shared-memory multiprocessor systems with interconnection networks and a large number of processors. Results of trace-driven simulations conducted on numerical benchmark routines to compare the performance of the three schemes are presented.

  18. Performance and scalability aspects of directory-based cache coherence in shared-memory multiprocessors

    SciTech Connect

    Picano, S.; Meyer, D.G.; Brooks, E.D. III; Hoag, J.E.

    1993-05-01

    We present a study that accentuates the performance and scalability aspects of directory-based cache coherence in multiprocessor systems. Using a multiprocessor with a software-based coherence scheme, efficient implementations rely heavily on the programmer`s ability to explicitly manage the memory system, which is typically handled by hardware support on other bus-based, shared memory multiprocessors. We describe a scalable, shared memory, cache coherent multiprocessor and present simulation results obtained on three parallel programs. This multiprocessor configuration exhibits high performance at no additional parallel programming cost.

  19. 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.

  20. 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)

  1. 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.

  2. A macro actor/token implementation of production systems on a data-flow multiprocessor

    SciTech Connect

    Sohn, A.; Gaudiot, J.-L.

    1991-12-31

    The importance of production systems in artificial intelligence has been repeatedly demonstrated by a number of expert systems. Much effort has therefore been expended on finding an efficient processing mechanism to process production systems. While data-flow principles of execution offer the promise of high programmability for numerical computations, the authors study here variable resolution actors, called macro actors, a processing mechanism for production systems. Characteristics of the production system paradigm are identified, based on which they introduce the concept of macro tokens as a companion to macro actors. A set of guidelines is identified in the context of production systems to derive well-formed macroactors from primitive micro actors. Parallel pattern matching is written in macro actors/tokens to be executed on the Macro Data-flow simulator. Simulation results demonstrate that the macro approach can be an efficient implementation of production systems.

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

    DOEpatents

    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.

  4. 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.

  5. 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.

  6. Controlling fine-grain non-numeric parallelism on a combinator-based multiprocessor system

    SciTech Connect

    Chu, Pong Ping.

    1989-01-01

    The author has developed a scheme to extend the SASL programming language and its run-time system for fine grain parallel processing. The proposed scheme provides a mechanism that can override the original lazy semantics by augmenting proper eager information. This information is first annotated in SASL programs and then translated to the combinator control tags by a new set of optimization rules. The effectiveness of this scheme has been evaluated through the simulation of a set of symbolic-oriented programs on an idealized shared-memory system. The results show that a considerable amount of parallelism can be extracted from a wide variety of application programs.

  7. Nearest Neighbor Searching in Binary Search Trees: Simulation of a Multiprocessor System.

    ERIC Educational Resources Information Center

    Stewart, Mark; Willett, Peter

    1987-01-01

    Describes the simulation of a nearest neighbor searching algorithm for document retrieval using a pool of microprocessors. Three techniques are described which allow parallel searching of a binary search tree as well as a PASCAL-based system, PASSIM, which can simulate these techniques. Fifty-six references are provided. (Author/LRW)

  8. 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.

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

    SciTech Connect

    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.

  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. A contention-based bus-control scheme for multiprocessor systems

    NASA Technical Reports Server (NTRS)

    Juang, Jie-Yong; Wah, Benjamin W.

    1991-01-01

    The authors study contention-based bus-control schemes for scheduling processors in using a bit-parallel shared bus. The protocol is designed under the requirements that each processor exhibit a random access behavior, that there be no centralized bus control in the system, and that access be granted in real time. The proposed scheme is based on splitting algorithms used in conventional contention-resolution schemes, and utilizes two-state information obtained from collision detection. Two versions of the bus-control scheme are studied. The static one resolves contentions of N requesting processors in an average of O(logW/2N) iterations, where W is the number of bits in the bit-parallel bus. An adaptive version resolves contentions in an average time that is independent of N.

  12. 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

  13. 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.

  14. 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.

  15. Bibliography On Multiprocessors And Distributed Processing

    NASA Technical Reports Server (NTRS)

    Miya, Eugene N.

    1988-01-01

    Multiprocessor and Distributed Processing Bibliography package consists of large machine-readable bibliographic data base, which in addition to usual keyword searches, used for producing citations, indexes, and cross-references. Data base contains UNIX(R) "refer" -formatted ASCII data and implemented on any computer running under UNIX(R) operating system. Easily convertible to other operating systems. Requires approximately one megabyte of secondary storage. Bibliography compiled in 1985.

  16. The fault-tolerant multiprocessor computer

    SciTech Connect

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

    1986-01-01

    This book presents studies of two fault-tolerant computer systems designed to meet the extreme reliability requirements for safety- critical functions in advanced NASA vehicles , plus a study of potential architectures for future flight control fault-tolerant systems, which might succeed the current generation of computers. While it is understood that these studies were done for NASA, they also have practical commercial applicability. The fault-tolerant multiprocessor (FTMP) architecture is a high reliability computer concept. The basic organization of the FTMP is that of a general purpose homogeneous multiprocessor. Three processors operate on a shared system (memory and l/O) bus. Replication and tight synchronization of all elements and hardware voting are 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.

  17. 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.

  18. 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.

  19. Effect of the application of a casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) paste and adhesive systems on bond durability of a fissure sealant.

    PubMed

    Borges, Boniek Castillo Dutra; Catelan, Anderson; Sasaki, Robson Tetsuo; Ambrosano, Gláucia Maria Bovi; Reis, André Figueiredo; Aguiar, Flávio Henrique Baggio

    2013-01-01

    This study aimed to evaluate the effect of the previous application of a casein phosphopeptide-amorphous calcium phosphate paste (MI Paste, MI) and adhesive systems on the bond durability of a fissure sealant. Ninety-eight enamel blocks were obtained from proximal surfaces of erupted third molars. Specimens were divided into 14 groups (n = 7) according to the previous application of MI (with and without) and the adhesive systems used (no adhesive system; hydrophobic resin of a three-step etch-and-rinse adhesive system; etch-and-rinse single-bottle adhesive system; all-in-one adhesive system; two-step self-etching adhesive system; additional phosphoric acid conditioning and all-in-one adhesive system; additional phosphoric acid conditioning and two-step self-etching adhesive system). A fissure sealant (Fluroshield) was applied and photoactivated for 20 s. Beams (~0.7 mm(2)) were prepared for the microtensile bond strength test, which was executed after 24 h or 6 months of water storage. Fractured specimens were analyzed by scanning electronic microscopy. Data were analyzed by two-way ANOVA with repeated measures/Tukey's test (P < 0.05). Groups that received MI application and adhesive systems presented higher means than those groups where MI was not applied. Higher frequency of cohesive failures was observed for groups with MI. Applying a CPP-ACP containing paste on enamel before adhesive systems was an effective method to increase bond durability of the sealant tested.

  20. 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

  1. Innovative design methodology for implementing heterogeneous multiprocessor architectures in VLSI

    SciTech Connect

    Tientien Li

    1983-01-01

    Considering the design cost of today's VLSI systems, advanced VLSI technology may not be cost-effective for implementing complex computer systems. In the paper, an innovative design approach which can drastically reduce the cost of implementing heterogeneous multiprocessor architectures in VLSI is presented. The author introduces high-level architectural design tools for assisting the design of multiprocessor systems with distributed memory modules and communication networks, and presents a logic/firmware synthesis scheme for automatically implementing multitasking structures and system service functions for multiprocessor architectures. Furthermore, the importance of the firmware synthesis aspect of VLSI system design is emphasized. Most logic of complex VLSI systems can be implemented very easily in firmware using the design approach introduced here. 10 references.

  2. 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.

  3. 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.

  4. Expanding symmetric multiprocessor capability through gang scheduling

    SciTech Connect

    Jette, M.A.

    1998-03-01

    Symmetric Multiprocessor (SMP) systems normally provide both space- sharing and time-sharing to insure high system utilization and good responsiveness. However the prevailing lack of concurrent scheduling for parallel programs precludes SMP use in addressing many large-scale problems. Tightly synchronized communications are impractical and normal time-sharing reduces the benefit of cache memory. Evidence gathered at Lawrence Livermore National Laboratory (LLNL) indicates that gang scheduling can increase the capability of SMP systems and parallel program performance without adverse impact upon system utilization or responsiveness.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. Dynamic Program Phase Detection in Distributed Shared-Memory Multiprocessors

    SciTech Connect

    Ipek, E; Martinez, J F; de Supinski, B R; McKee, S A; Schulz, M

    2006-03-06

    We present a novel hardware mechanism for dynamic program phase detection in distributed shared-memory (DSM) multiprocessors. We show that successful hardware mechanisms for phase detection in uniprocessors do not necessarily work well in DSM systems, since they lack the ability to incorporate the parallel application's global execution information and memory access behavior based on data distribution. We then propose a hardware extension to a well-known uniprocessor mechanism that significantly improves phase detection in the context of DSM multiprocessors. The resulting mechanism is modest in size and complexity, and is transparent to the parallel application.

  10. 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.

  11. 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.

  12. Message-passing multiprocessor simulator

    SciTech Connect

    Dunigan, T.H.

    1986-05-01

    The structure and use of a message-passing multiprocessor simulator are described. The simulator provides a multitasking environment for the development of algorithms for parallel processors using either shared or local memories. The simulator may be used from C or FORTRAN and provides a library of subroutines for task control and message passing. The simulator produces a trace file that can be used for debugging, performance analysis, or graphical display. 9 refs., 7 figs.

  13. Fault-tolerant multiprocessor computer

    SciTech Connect

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

    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 systms 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, aceptance-test/diagnostic, applications, and support software; FTM reliability and availability models; SIFT hardware design; and SIFT validation and verification.

  14. Access ordering and coherence in shared-memory multi-processors

    SciTech Connect

    Scheurich, C.E.

    1989-01-01

    Shared memory forms a convenient communication medium in a multitasking multiprocessor system. However, different multiprocessors can execute the same program in different manners, possibly yielding incorrect results because the machines adhere to different rules. Differences in behavior are due to the varying approaches of designers to attack the shared memory access latency problem in multiprocessors. In particular, the manner in which multiple copies of data are controlled and the manner in which memory accesses are sequenced, propagated, and buffered has impact on the behavior of the multiprocessor. Three shared memory execution models, referred to as concurrency models, are defined. The precise properties of processors, memories, and interconnection networks are derived to comply to each of the concurrency models. The usefulness of these concurrency models is demonstrated by showing the simplicity with which their rules can be applied to allow buffering of memory accesses, implement combining networks, prove cache coherence protocols correct, and design lockup-free caches. Specific examples are provided, both of a cache-based multiprocessor potentially without bottlenecks and of a cache-based multiprocessor employing lockup-free caches which can continue to service the processor while concurrently servicing one of several access misses. The paradigms and associated conditions presented in this thesis form a set of powerful tools allowing multiprocessor designers to concentrate on functionality while being burdened less with side-effect analysis.

  15. 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.

  16. 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.

  17. The Drosophila melanogaster seminal fluid protein Acp62F is a protease inhibitor that is toxic upon ectopic expression.

    PubMed

    Lung, Oliver; Tram, Uyen; Finnerty, Casey M; Eipper-Mains, Marcie A; Kalb, John M; Wolfner, Mariana F

    2002-01-01

    Drosophila melanogaster seminal fluid proteins stimulate sperm storage and egg laying in the mated female but also cause a reduction in her life span. We report here that of eight Drosophila seminal fluid proteins (Acps) and one non-Acp tested, only Acp62F is toxic when ectopically expressed. Toxicity to preadult male or female Drosophila occurs upon one exposure, whereas multiple exposures are needed for toxicity to adult female flies. Of the Acp62F received by females during mating, approximately 10% enters the circulatory system while approximately 90% remains in the reproductive tract. We show that in the reproductive tract, Acp62F localizes to the lumen of the uterus and the female's sperm storage organs. Analysis of Acp62F's sequence, and biochemical assays, reveals that it encodes a trypsin inhibitor with sequence and structural similarities to extracellular serine protease inhibitors from the nematode Ascaris. In light of previous results demonstrating entry of Acp62F into the mated female's hemolymph, we propose that Acp62F is a candidate for a molecule to contribute to the Acp-dependent decrease in female life span. We propose that Acp62F's protease inhibitor activity exerts positive protective functions in the mated female's reproductive tract but that entry of a small amount of this protein into the female's hemolymph could contribute to the cost of mating. PMID:11805057

  18. 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.

  19. Performance degradation due to multiprogramming and system overheads in real workloads - Case study on a shared memory multiprocessor

    NASA Technical Reports Server (NTRS)

    Dimpsey, R. T.; Iyer, R. K.

    1990-01-01

    The performance degradation due to the multiprogramming (MP) overhead in a parallel execution environment is quantified. In addition, total system overhead is also measured. A methodology, which estimates the MP overhead present in real workloads, is illustrated with real measurents. It is found that MP overhead usually consumes between 10 and 23 percent of the processing power available to parallel programs. The mean MP overhead is determined to be 16 percent which is well over half the total system overhead executed on the system (the mean system overhead is determined to be 24 percent of the processing power). It is found that MP overhead, total system overhead, and application completion time are all moderately correlated.

  20. 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.

  1. 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.

  2. Multiprocessor computing for images

    SciTech Connect

    Cantoni, V. ); Levialdi, S. )

    1988-08-01

    A review of image processing systems developed until now is given, highlighting the weak points of such systems and the trends that have dictated their evolution through the years producing different generations of machines. Each generation may be characterized by the hardware architecture, the programmability features and the relative application areas. The need for multiprocessing hierarchical systems is discussed focusing on pyramidal architectures. Their computational paradigms, their virtual and physical implementation, their programming and software requirements, and capabilities by means of suitable languages, are discussed.

  3. 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.

  4. 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.

  5. Supernodal synmbolic Cholesky factorization on a local-memory multiprocessor

    SciTech Connect

    Ng, E.

    1991-06-01

    In this paper, we consider the symbolic factorization step in computing the Cholesky factorization of a sparse symmetric positive definite matrix on distributed-memory multiprocessor systems. By exploiting the supernodal structure in the Cholesky factor, the performance of a previous parallel symbolic factorization algorithm is improved. Empirical tests demonstrate that there can be drastic reduction in the execution time required by the new algorithm on an Intel iPSC/2 hypercube. 23 refs., 8 figs.

  6. 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.

  7. Verifying a multiprocessor cache controller using random case generation

    SciTech Connect

    Wood, D.A.; Gibson, G.A.; Katz, R.H. )

    1989-01-01

    The newest generation of cache controller chips provide coherency to support multiprocessor systems, i.e., the controllers coordinate access to the cache memories to guarantee a single global view of memory. The cache coherency protocols they implement complicate the controller design, making design verification difficult. In the design of the cache controller for SPUR, a shared memory multiprocessor designed and built at U.C. Berkeley, the authors developed a random tester to generate and verify the complex interactions between multiple processors in the the functional simulation. Replacing the CPU model, the tester generates memory references by randomly selecting from a script of actions and checks. The checks verify correct completion of their corresponding actions. The tester was easy to develop, and detected over half of the functional bugs uncovered during simulation. They used an assembly language version of the random tester to verify the prototype hardware. A multiprocessor system is operational; it runs the Sprite operating system and is being used for experiments in parallel programming.

  8. 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.

  9. 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

  10. 7 CFR 701.44 - Agricultural Conservation Program (ACP) contracts.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 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 PROGRAM... General § 701.44 Agricultural Conservation Program (ACP) contracts. Contracts for ACP that are, or...

  11. 7 CFR 701.44 - Agricultural Conservation Program (ACP) contracts.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 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 PROGRAM... General § 701.44 Agricultural Conservation Program (ACP) contracts. Contracts for ACP that are, or...

  12. 7 CFR 701.44 - Agricultural Conservation Program (ACP) contracts.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 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 PROGRAM... General § 701.44 Agricultural Conservation Program (ACP) contracts. Contracts for ACP that are, or...

  13. 7 CFR 701.44 - Agricultural Conservation Program (ACP) contracts.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 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 PROGRAM... General § 701.44 Agricultural Conservation Program (ACP) contracts. Contracts for ACP that are, or...

  14. 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...

  15. 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.

  16. Sorting large files on a backend multiprocessor

    SciTech Connect

    Beck, M.; Bitton, D.; Wilkinson, W.K.

    1988-07-01

    A fundamental measure of processing power in a database management system is the performance of the sort utility it provides. When sorting a large data file on a serial computer, performance is limited by factors involving processor speed, memory capacity, and I/O bandwidth. In this paper, the authors investigate the feasibility and efficiency of a parallel sort-merge algorithm through implementation on the JASMIN prototype, a backend multiprocessor built around a fast packet bus. The authors describe the design and implementation of a parallel sort utility. They then present and analyze the results of measurements corresponding to a range of file sizes and processor configurations. Their results show that using current, off-the-shelf technology coupled with a streamlined distributed operating system, three- and five-microprocessor configurations provide a very cost-effective sort of large files. The three-processor configuration sorts a 100 Mbyte file in 1 h, which compares well to commercial sort packages available on high-performance mainframes. In additional experiments, the authors investigate a model to tune their sort software and scale their results to higher processor and network capabilities.

  17. 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

  18. Multiprocessor scheduling problem with machine constraints

    NASA Astrophysics Data System (ADS)

    He, Yong; Tan, Zhiyi

    2001-09-01

    This paper investigates multiprocessor scheduling with machine constraints, which has many applications in the flexible manufacturing systems and in VLSI chip design. Machines have different starting times and each machine can schedule at most k jobs in a period. The objective is to minimizing the makespan. For this strogly NP-hard problem, it is important to design near-optimal approximation algorithms. It is known that Modified LPT algorithm has a worst-case ratio of 3/2-1/(2m) for kequals2 where m is the number of machines. For k>2, no good algorithm has been got in the literature. In this paper, we prove the worst-case ratio of Modified LPT is less than 2. We further present an approximation algorithm Matching and show it has a worst-case ratio 2-1/m for every k>2. By introducing parameters, we get two better worst-case ratios which show the Matching algorithm is near optimal for two special cases.

  19. 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.

  20. 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

  1. 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.

  2. Instrumentation, performance visualization, and debugging tools for multiprocessors

    NASA Technical Reports Server (NTRS)

    Yan, Jerry C.; Fineman, Charles E.; Hontalas, Philip J.

    1991-01-01

    The need for computing power has forced a migration from serial computation on a single processor to parallel processing on multiprocessor architectures. However, without effective means to monitor (and visualize) program execution, debugging, and tuning parallel programs becomes intractably difficult as program complexity increases with the number of processors. Research on performance evaluation tools for multiprocessors is being carried out at ARC. Besides investigating new techniques for instrumenting, monitoring, and presenting the state of parallel program execution in a coherent and user-friendly manner, prototypes of software tools are being incorporated into the run-time environments of various hardware testbeds to evaluate their impact on user productivity. Our current tool set, the Ames Instrumentation Systems (AIMS), incorporates features from various software systems developed in academia and industry. The execution of FORTRAN programs on the Intel iPSC/860 can be automatically instrumented and monitored. Performance data collected in this manner can be displayed graphically on workstations supporting X-Windows. We have successfully compared various parallel algorithms for computational fluid dynamics (CFD) applications in collaboration with scientists from the Numerical Aerodynamic Simulation Systems Division. By performing these comparisons, we show that performance monitors and debuggers such as AIMS are practical and can illuminate the complex dynamics that occur within parallel programs.

  3. 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.

  4. 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.

  5. 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.

  6. Power-Aware Compiler Controllable Chip Multiprocessor

    NASA Astrophysics Data System (ADS)

    Shikano, Hiroaki; Shirako, Jun; Wada, Yasutaka; Kimura, Keiji; Kasahara, Hironori

    A power-aware compiler controllable chip multiprocessor (CMP) is presented and its performance and power consumption are evaluated with the optimally scheduled advanced multiprocessor (OSCAR) parallelizing compiler. The CMP is equipped with power control registers that change clock frequency and power supply voltage to functional units including processor cores, memories, and an interconnection network. The OSCAR compiler carries out coarse-grain task parallelization of programs and reduces power consumption using architectural power control support and the compiler's power saving scheme. The performance evaluation shows that MPEG-2 encoding on the proposed CMP with four CPUs results in 82.6% power reduction in real-time execution mode with a deadline constraint on its sequential execution time. Furthermore, MP3 encoding on a heterogeneous CMP with four CPUs and four accelerators results in 53.9% power reduction at 21.1-fold speed-up in performance against its sequential execution in the fastest execution mode.

  7. 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

  8. Frontal optimization algorithms for multiprocessor computers

    SciTech Connect

    Sergienko, I.V.; Gulyanitskii, L.F.

    1981-11-01

    The authors describe one of the approaches to the construction of locally optimal optimization algorithms on multiprocessor computers. Algorithms of this type, called frontal, have been realized previously on single-processor computers, although this configuration does not fully exploit the specific features of their computational scheme. Experience with a number of practical discrete optimization problems confirms that the frontal algorithms are highly successful even with single-processor computers. 9 references.

  9. 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.

  10. On-line data acquisition using a multiprocessor architecture

    SciTech Connect

    DeAsmundis, R.; Spadaccini, G.; Terrasi, F. )

    1989-10-01

    In this paper a system for on-line data processing based on a multiprocessor architecture and a PC/AT is presented. Many improvements with respect to a previous published architecture have been introduced in order to speed-up the processing and the display features of the system. A new CAMAC module for event identification and triggering has been designed and assembled. Collected data are now recorded on a magnetic tape unit, and integrated data (1-dim. and 2-dim. spectra) are handled by a PC/AT linked directly to the system. Although almost the whole code is stored in Eprom, the PC/AT supports also mass-storage and development features for debug phases of the system software.

  11. 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.

  12. 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.

  13. 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.

  14. Multiprocessor switch with selective pairing

    DOEpatents

    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

  15. The effect of CPP-ACP and Nd:YAG laser on the bond strength of softened dentin.

    PubMed

    Kamozaki, Maria Beatriz Beber; Prakki, Anuradha; Perote, Letícia Carvalho Coutinho Costa; Gutierrez, Natalia Cortez; Pagani, Clovis

    2015-01-01

    The purpose of this study was to investigate the effect of CPP-ACP treatment and Nd:YAG laser on microtensile bond strength (µTBS) of softened dentin. Sixty samples were obtained from thirty sound third molars. All samples were submitted to dentin softening procedure, by the immersion of the specimens in 30 mL of Sprite Zero for 30 min. Afterwards, the samples were randomly divided according to the CPP-ACP treatment: CG-Control group; MP-treated with CPP-ACP paste (MI Paste); MPP-treated with CPP-ACP+900 ppm NaF paste (MI Paste Plus). Each group was further divided according to bonding procedure: NL-No laser; L-Laser irradiation after adhesive application and before polymerization. The laser parameters used were 1.4 W, 10 Hz, 140 mJ/pulse, with an optic fiber of 320 µm, generating energy of 174 J/cm(2) per pulse. All samples were restored with Clearfil SE Bond/Filtek Z350 XT. After 24 h, the restored samples were cut into beams (± 1 mm(2) adhesive interface area) and subjected to a µTBS test. Data were analyzed by two-way ANOVA test and Holm-Sidak post-hoc method (α = 0.05). The treatment with CPP-ACP pastes did not significantly affect softened dentin µTBS (p = 0.070). Statistic revealed significant reduction on µTBS values for CG/L, leading to the rejection of the second null hypothesis (p < 0.001). Both CPP-ACP based pastes did not affect µTBS of softened dentin for the adhesive system utilized. The Nd:YAG laser irradiation after application of adhesive system did affect µTBS values of softened dentin samples untreated with CPP-ACP based pastes. PMID:26083086

  16. 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

  17. 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

  18. 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

  19. 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.

  20. A VLSI chip set for a multiprocessor workstation; Part II: A memory management unit and cache controller

    SciTech Connect

    Jeong, D.K.; Wood, D.A.; Gibson, G.A.; Eggers, S.J.; Hodges, D.A.; Katz, R.H.; Patterson, D.A. )

    1989-12-01

    This paper describes a memory management unit and a cache controller (MMU/CC) for a shared memory multiprocessor. The MMU/CC implements a novel memory management scheme, called in-cache address translation, that does not require a translation lookaside buffer (TLB). It also implements a snooping but protocol to maintain data consistency across all caches in the system. Both chips are implemented in a 1.6-{mu}m double-layer-metal CMOS technology, and are being used in a multiprocessor workstation (SPUR) successfully executing a UNIX-like network-based operating system called Sprite as well as many applications including LISP programs.

  1. Polyketide β-Branching in Bryostatin Biosynthesis: Identification of Surrogate Acetyl-ACP Donors for BryR, an HMG-ACP Synthase

    PubMed Central

    Buchholz, Tonia J.; Rath, Christopher M.; Lopanik, Nicole B.; Gardner, Noah P.; Håkansson, Kristina; Sherman, David H.

    2010-01-01

    Summary In vitro analysis of natural product biosynthetic gene products isolated from unculturable symbiotic bacteria is necessary to probe the functionalities of these enzymes. Herein, we report the biochemical characterization of BryR, the 3-hydroxy-3-methylglutaryl (HMG)-CoA synthase (HMGS) homolog implicated in β-branching at C13 and C21 of the core ring system from the bryostatin metabolic pathway (Bry). We confirmed the activity of BryR using two complementary methods, radio-SDS PAGE and Fourier Transform Ion Cyclotron Resonance-Mass Spectrometry (FTICR-MS). The activity of BryR depended on pairing of the native acetoacetyl-BryM3 acceptor acyl carrier protein (ACP) with an appropriate donor acetyl-ACP from a heterologous HMGS cassette. Additionally, the ability of BryR to discriminate between various ACPs was assessed using a surface plasmon resonance (SPR)-based protein-protein binding assay. Our data suggest that specificity for a protein-bound acyl group is a distinguishing feature between HMGS homologs found in PKS or PKS/NRPS biosynthetic pathways and those of primary metabolism. These findings reveal an important example of molecular recognition between protein components that are essential for biosynthetic fidelity in natural product assembly and modification. PMID:21035732

  2. Association between ACP(1) genetic polymorphism and favism.

    PubMed

    Polzonetti, V; Passini, V; Lucarini, N

    2011-01-01

    An association between favism (a hemolytic reaction to consumption of fava beans), glucose-6-phosphate dehydrogenase deficiency (G6PD(-)) and acid phosphatase locus 1 (ACP(1)) phenotypes has been reported; the frequency of carriers of the p(a) and p(c) ACP(1) alleles was found to be significantly higher in G6PD(-) individuals showing favism than in the general population. Here, we investigated the hypothesis that favism is caused by toxic Vicia faba substances, which in some ACP(1) phenotypes cause increased phosphorylation and consequently increased glycolysis, with strong reduction in reduced glutathione production, resulting in hemolysis. It has been demonstrated that ACP(1) f isoforms have physiological functions different from those of s isoforms and are responsible for most of the phosphatase activity, in addition to being less stable in the presence of oxidizing molecules. Thus, the C, CA and A phenotypes, characterized by lower concentrations of f isoforms, could be more susceptible to damage by oxidative events compared to the other phenotypes. To test this hypothesis, the (f+s) enzymatic activity of different ACP(1) phenotypes with and without added V. faba extract was analyzed. Enzymatic activities of ACP(1) A, -CA, -C groups (low activity) and -B, -BA, -CB groups (high activity) were significantly different after addition of V. faba extract. Phenotypes A, CA and C had extremely low enzymatic activity levels, which would lead to low levels of reduced glutathione and bring about erythrocyte lysis. PMID:21644204

  3. 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

  4. 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.

  5. 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.

  6. Maximizing run time performance of deployed data flow graphs on a multiprocessor architecture

    NASA Astrophysics Data System (ADS)

    Tobias, Richard J.; Hunt, Peter D.

    1993-10-01

    This paper discusses a practical solution for supporting the deployment of data flow graphs onto the Loral/Rolm Computer Systems, Inc. vector processing multi-processor architecture. It outlines the support software (both workstation hosted and target system hosted) that is required to design, debug, and maximize deployed data flow graph performance on the multiprocessor architecture. The deployment process guarantees real-time deadlines, minimizes run time scheduling overhead, and minimizes designer partitioning input. It is known that determining effective run time data flow graph node schedules for multi-processor architectures is an NP-complete class of problem not well suited to real-time systems. Loral/Rolm Computer Systems, Inc.'s vector processing toolset recognizes this problem and this paper discusses a prescheduling and pre-assignment approach for partitioning data flow graphs to available hardware resources. In particular the toolset components (which are based upon an enhanced data flow graph language) of workstation pre-assignment, prescheduling, run time gross allocation and local compute element dispatching are discussed in detail.

  7. 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.

  8. Performance of multiprocessors and parallel algorithms: Quick-sort, a case study

    SciTech Connect

    Patil, I.M.

    1989-01-01

    Performance of parallel algorithms on multiprocessors has been traditionally analyzed by looking at either the algorithm or the architecture of the multiprocessor system. However, it is important to study the combined effect of both these factors in order to evaluate and predict performance. A different methodology based on approximate trace-driven simulation is adopted in this thesis to study the performance of a class of non-numerical algorithms. Performance of parallel quick-sort and parallel quick-merge sort is investigated in order to demonstrate the methodology as well as develop an understanding of the limitations imposed by a cache-based single bus environment on achievable speedup. A wide range of issues including the effect of cache parameters, coherency protocol, scheduling mechanisms and technology effects are discussed in the context of performance of the two versions of parallel quick-sort.

  9. 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

  10. A cache-aided multiprocessor rollback recovery scheme

    NASA Technical Reports Server (NTRS)

    Wu, Kun-Lung; Fuchs, W. Kent

    1989-01-01

    This paper demonstrates how previous uniprocessor cache-aided recovery schemes can be applied to multiprocessor architectures, for recovering from transient processor failures, utilizing private caches and a global shared memory. As with cache-aided uniprocessor recovery, the multiprocessor cache-aided recovery scheme of this paper can be easily integrated into standard bus-based snoopy cache coherence protocols. A consistent shared memory state is maintained without the necessity of global check-pointing.

  11. 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.

  12. 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

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

    PubMed

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

    1995-03-01

    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.

  14. 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.

  15. Thermal induced intramolecular [2 + 2] cycloaddition of allene-ACPs.

    PubMed

    Chen, Kai; Sun, Run; Xu, Qin; Wei, Yin; Shi, Min

    2013-06-28

    A facile synthetic method for preparation of bicyclo[4.2.0] nitrogen heterocycles has been developed via a thermal induced intramolecular [2 + 2] cycloaddition reaction of allene-ACPs. The DFT calculations indicate that this intramolecular cycloaddition proceeds in a concerted manner and a strained small ring is essential.

  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. 3-Oxoacyl-[ACP] reductase from oilseed rape (Brassica napus).

    PubMed

    Sheldon, P S; Kekwick, R G; Smith, C G; Sidebottom, C; Slabas, A R

    1992-04-01

    3-Oxoacyl-[ACP] reductase (E.C. 1.1.1.100, alternatively known as beta-ketoacyl-[ACP] reductase), a component of fatty acid synthetase has been purified from seeds of rape by ammonium sulphate fractionation, Procion Red H-E3B chromatography, FPLC gel filtration and high performance hydroxyapatite chromatography. The purified enzyme appears on SDS-PAGE as a number of 20-30 kDa components and has a strong tendency to exist in a dimeric form, particularly when dithiothreitol is not present to reduce disulphide bonds. Cleveland mapping and cross-reactivity with antiserum raised against avocado 3-oxoacyl-[ACP] reductase both indicate that the multiple components have similar primary structures. On gel filtration the enzyme appears to have a molecular mass of 120 kDa suggesting that the native structure is tetrameric. The enzyme has a strong preference for the acetoacetyl ester of acyl carrier protein (Km = 3 microM) over the corresponding esters of the model substrates N-acetyl cysteamine (Km = 35 mM) and CoA (Km = 261 microM). It is inactivated by dilution but this can be partly prevented by the inclusion of NADPH. Using an antiserum prepared against avocado 3-oxoacyl-[ACP] reductase, the enzyme has been visualised inside the plastids of rape embryo and leaf tissues by immunoelectron microscopy. Amino acid sequencing of two peptides prepared by digestion of the purified enzyme with trypsin showed strong similarities with 3-oxoacyl-[ACP] reductase from avocado pear and the Nod G gene product from Rhizobium meliloti.

  18. 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

  19. 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.

  20. 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.

  1. Experimental evaluation of multiprocessor cache-based error recovery

    NASA Technical Reports Server (NTRS)

    Janssens, Bob; Fuchs, W. K.

    1991-01-01

    Several variations of cache-based checkpointing for rollback error recovery in shared-memory multiprocessors have been recently developed. By modifying the cache replacement policy, these techniques use the inherent redundancy in the memory hierarchy to periodically checkpoint the computation state. Three schemes, different in the manner in which they avoid rollback propagation, are evaluated. By simulation with address traces from parallel applications running on an Encore Multimax shared-memory multiprocessor, the performance effect of integrating the recovery schemes in the cache coherence protocol are evaluated. The results indicate that the cache-based schemes can provide checkpointing capability with low performance overhead but uncontrollable high variability in the checkpoint interval.

  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. 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...

  4. Preliminary calibration of the ACP safeguards neutron counter

    NASA Astrophysics Data System (ADS)

    Lee, T. H.; Kim, H. D.; Yoon, J. S.; Lee, S. Y.; Swinhoe, M.; Menlove, H. O.

    2007-10-01

    The Advanced Spent Fuel Conditioning Process (ACP), a kind of pyroprocess, has been developed at the Korea Atomic Energy Research Institute (KAERI). Since there is no IAEA safeguards criteria for this process, KAERI has developed a neutron coincidence counter to make it possible to perform a material control and accounting (MC&A) for its ACP materials for the purpose of a transparency in the peaceful uses of nuclear materials at KAERI. The test results of the ACP Safeguards Neutron Counter (ASNC) show a satisfactory performance for the Doubles count measurement with a low measurement error for its cylindrical sample cavity. The neutron detection efficiency is about 21% with an error of ±1.32% along the axial direction of the cavity. Using two 252Cf neutron sources, we obtained various parameters for the Singles and Doubles rates for the ASNC. The Singles, Doubles, and Triples rates for a 252Cf point source were obtained by using the MCNPX code and the results for the ft8 cap multiplicity tally option with the values of ɛ, fd, and ft measured with a strong source most closely match the measurement results to within a 1% error. A preliminary calibration curve for the ASNC was generated by using the point model equation relationship between 244Cm and 252Cf and the calibration coefficient for the non-multiplying sample is 2.78×10 5 (Doubles counts/s/g 244Cm). The preliminary calibration curves for the ACP samples were also obtained by using an MCNPX simulation. A neutron multiplication influence on an increase of the Doubles rate for a metal ingot and UO2 powder is clearly observed. These calibration curves will be modified and complemented, when hot calibration samples become available. To verify the validity of this calibration curve, a measurement of spent fuel standards for a known 244Cm mass will be performed in the near future.

  5. Compiling Lisp for evaluation on a tightly coupled multiprocessor

    SciTech Connect

    Harrison, W.L. III

    1986-03-20

    The problem of compiling Lisp for efficient evaluation on a large, tightly coupled, shared memory multiprocessor is investigated. A representation for s-expressions which facilitates parallel evaluation is proposed, along with a sequence of transformations, to be applied to the functions comprising a Lisp program, which reveal and exploit parallelism. 26 refs., 170 figs.

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. ACP5 (Uteroferrin): phylogeny of an ancient and conserved gene expressed in the endometrium of mammals.

    PubMed

    Padua, Maria B; Lynch, Vincent J; Alvarez, Natalia V; Garthwaite, Mark A; Golos, Thaddeus G; Bazer, Fuller W; Kalkunte, Satyan; Sharma, Surendra; Wagner, Gunter P; Hansen, Peter J

    2012-04-01

    Type 5 acid phosphatase (ACP5; also known as tartrate-resistant acid phosphatase or uteroferrin) is a metalloprotein secreted by the endometrial glandular epithelium of pigs, mares, sheep, and water buffalo. In this paper, we describe the phylogenetic distribution of endometrial expression of ACP5 and demonstrate that endometrial expression arose early in evolution (i.e., before divergence of prototherian and therian mammals ~166 million years ago). To determine expression of ACP5 in the pregnant endometrium, RNA was isolated from rhesus, mouse, rat, dog, sheep, cow, horse, armadillo, opossum, and duck-billed platypus. Results from RT-PCR and RNA-Seq experiments confirmed that ACP5 is expressed in all species examined. ACP5 was also demonstrated immunochemically in endometrium of rhesus, marmoset, sheep, cow, goat, and opossum. Alignment of inferred amino acid sequences shows a high conservation of ACP5 throughout speciation, with species-specific differences most extensive in the N-terminal and C-terminal regions of the protein. Analysis by Selecton indicated that most of the sites in ACP5 are undergoing purifying selection, and no sites undergoing positive selection were found. In conclusion, endometrial expression of ACP5 is a common feature in all orders of mammals and has been subjected to purifying selection. Expression of ACP5 in the uterus predates the divergence of therians and prototherians. ACP5 is an evolutionary conserved gene that likely exerts a common function important for pregnancy in mammals using a wide range of reproductive strategies. PMID:22278982

  11. ACP5 (Uteroferrin): phylogeny of an ancient and conserved gene expressed in the endometrium of mammals.

    PubMed

    Padua, Maria B; Lynch, Vincent J; Alvarez, Natalia V; Garthwaite, Mark A; Golos, Thaddeus G; Bazer, Fuller W; Kalkunte, Satyan; Sharma, Surendra; Wagner, Gunter P; Hansen, Peter J

    2012-04-01

    Type 5 acid phosphatase (ACP5; also known as tartrate-resistant acid phosphatase or uteroferrin) is a metalloprotein secreted by the endometrial glandular epithelium of pigs, mares, sheep, and water buffalo. In this paper, we describe the phylogenetic distribution of endometrial expression of ACP5 and demonstrate that endometrial expression arose early in evolution (i.e., before divergence of prototherian and therian mammals ~166 million years ago). To determine expression of ACP5 in the pregnant endometrium, RNA was isolated from rhesus, mouse, rat, dog, sheep, cow, horse, armadillo, opossum, and duck-billed platypus. Results from RT-PCR and RNA-Seq experiments confirmed that ACP5 is expressed in all species examined. ACP5 was also demonstrated immunochemically in endometrium of rhesus, marmoset, sheep, cow, goat, and opossum. Alignment of inferred amino acid sequences shows a high conservation of ACP5 throughout speciation, with species-specific differences most extensive in the N-terminal and C-terminal regions of the protein. Analysis by Selecton indicated that most of the sites in ACP5 are undergoing purifying selection, and no sites undergoing positive selection were found. In conclusion, endometrial expression of ACP5 is a common feature in all orders of mammals and has been subjected to purifying selection. Expression of ACP5 in the uterus predates the divergence of therians and prototherians. ACP5 is an evolutionary conserved gene that likely exerts a common function important for pregnancy in mammals using a wide range of reproductive strategies.

  12. DiFX: A Software Correlator for Very Long Baseline Interferometry Using Multiprocessor Computing Environments

    NASA Astrophysics Data System (ADS)

    Deller, A. T.; Tingay, S. J.; Bailes, M.; West, C.

    2007-03-01

    We describe the development of an FX-style correlator for very long baseline interferometry (VLBI), implemented in software and intended to run in multiprocessor computing environments, such as large clusters of commodity machines (Beowulf clusters) or computers specifically designed for high-performance computing, such as multiprocessor shared-memory machines. We outline the scientific and practical benefits for VLBI correlation, these chiefly being due to the inherent flexibility of software and the fact that the highly parallel and scalable nature of the correlation task is well suited to a multiprocessor computing environment. We suggest scientific applications where such an approach to VLBI correlation is most suited and will give the best returns. We report detailed results from the Distributed FX (DiFX) software correlator running on the Swinburne supercomputer (a Beowulf cluster of ~300 commodity processors), including measures of the performance of the system. For example, to correlate all Stokes products for a 10 antenna array with an aggregate bandwidth of 64 MHz per station, and using typical time and frequency resolution, currently requires an order of 100 desktop-class compute nodes. Due to the effect of Moore's law on commodity computing performance, the total number and cost of compute nodes required to meet a given correlation task continues to decrease rapidly with time. We show detailed comparisons between DiFX and two existing hardware-based correlators: the Australian Long Baseline Array S2 correlator and the NRAO Very Long Baseline Array correlator. In both cases, excellent agreement was found between the correlators. Finally, we describe plans for the future operation of DiFX on the Swinburne supercomputer for both astrophysical and geodetic science.

  13. 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

  14. 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.

  15. 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.

  16. 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

  17. 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.

  18. 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.

  19. Plasma physics modeling and the Cray-2 multiprocessor

    SciTech Connect

    Killeen, J.

    1985-01-01

    The importance of computer modeling in the magnetic fusion energy research program is discussed. The need for the most advanced supercomputers is described. To meet the demand for more powerful scientific computers to solve larger and more complicated problems, the computer industry is developing multiprocessors. The role of the Cray-2 in plasma physics modeling is discussed with some examples. 28 refs., 2 figs., 1 tab.

  20. 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.

  1. A Multiprocessor SoC Architecture with Efficient Communication Infrastructure and Advanced Compiler Support for Easy Application Development

    NASA Astrophysics Data System (ADS)

    Urfianto, Mohammad Zalfany; Isshiki, Tsuyoshi; Khan, Arif Ullah; Li, Dongju; Kunieda, Hiroaki

    This paper presentss a Multiprocessor System-on-Chips (MPSoC) architecture used as an execution platform for the new C-language based MPSoC design framework we are currently developing. The MPSoC architecture is based on an existing SoC platform with a commercial RISC core acting as the host CPU. We extend the existing SoC with a multiprocessor-array block that is used as the main engine to run parallel applications modeled in our design framework. Utilizing several optimizations provided by our compiler, an efficient inter-communication between processing elements with minimum overhead is implemented. A host-interface is designed to integrate the existing RISC core to the multiprocessor-array. The experimental results show that an efficacious integration is achieved, proving that the designed communication module can be used to efficiently incorporate off-the-shelf processors as a processing element for MPSoC architectures designed using our framework.

  2. 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.

  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. 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

  6. 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

  7. Highly reliable multiprocessors. [for commerical transport aircraft

    NASA Technical Reports Server (NTRS)

    Murray, N. D.; Hopkins, A. L.; Wensley, J. H.

    1977-01-01

    Highly reliable fault-tolerant computer systems are discussed for use in flight-critical avionic and control systems of future commercial transport aircraft. Such aircraft are envisioned to have integrated systems, to be terminally configured, and to be equipped with fly-by-wire flight control systems, all of which require highly reliable, fault-tolerant computers. Two candidate computer architectures are identified as having the potential of satisfying the commercial transport aircraft requirements.

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. Modeling and analysis of multiprocessor architectures

    NASA Technical Reports Server (NTRS)

    Yalamanchili, S.; Carpenter, T.

    1989-01-01

    Some technologies developed for system level modeling and analysis of algorithms/architectures using an architecture design and development system are reviewed. Modeling and analysis is described with attention given to modeling constraints and analysis using constrained software graphs. An example is presented of an ADAS graph and its associated attributes, such as firing delay, token consume rate, token produce rate, firing threshold, firing condition, arc queue lengths, associated C or Ada functional model, and stochastic behavior.

  13. 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.

  14. 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.

  15. 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.

  16. Addressing, routing, and broadcasting in hexagonal mesh multiprocessors

    SciTech Connect

    Chen, M.S. ); Shin, K.G.; Kandlur, D.D. )

    1990-01-01

    A family of 6-regular graphs, called hexagonal meshes or H-meshes, is considered as a multiprocessor interconnection network. Processing nodes on the periphery of an H-mesh are first wrapped around to achieve regularity and homogeneity. The diameter of a wrapped H-mesh is shown to be of O(p{sup 1}2/), where p is the number of nodes in the H-mesh. An elegant, distributed routing scheme is developed for wrapped H-meshes so that each node in an H-mesh can compute shortest paths from itself to any other node with a straightforward algorithm of O(1) using the addresses of the source-destination pair only, i.e., independent of the network's size. This is in sharp contract with those previously known algorithms that rely on using routing tables. The authors also develop an efficient point-to-point broadcasting algorithm for the H-meshes which is shown to be optimal in the number of required communication steps. The wrapped H-meshes are compared against some of other existing multiprocessor interconnection networks. such as hypercubes, trees, and square meshes. The comparison reinforces the attractiveness of the H-mesh architecture.

  17. 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.

  18. 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.

  19. Optical interconnects for multiprocessors in computer backplane

    NASA Astrophysics Data System (ADS)

    Kim, Tae-Jin; Tu, Kun-Yii; Ramsey, Darrell; Oh, Tchang-Hun; Kostuk, Raymond K.

    1995-04-01

    Optical interconnects have potential advantage over electrical methods at the backplane level. In this paper we present a free-space optical connection cube for backplane interconnect applications. The connection cube has a symmetric structure which reduces skew between boards. It can be expanded into a 3-dimensional configuration for parallel communication using vertical-cavity surface-emitting laser (VCSEL) and receiver arrays. Fan-out and fan-in of propagation beams for the connection cube are realized using volume holographic optical elements formed in dichromated gelatin (DCG) emulsion. A four-port communication system has been demonstrated using the connection cube and tested at 500 MHz. In this paper, advantages and detailed implementation of the free-space optical connection cube are presented. Design considerations for fan-out/in holographic gratings and alignment tolerances for the connection cube are discussed. Characteristics of the connection cube are also presented.

  20. Solar detoxification of wastewater in a novel aerated cascade photoreactor (ACP).

    PubMed

    Xi, W; Geissen, S U; Vogelpohl, A

    2001-01-01

    A newly developed aerated cascade photoreactor (ACP), based on a non-concentrating suspension photoreactor, combines the advantages of a cascade with the increased mass-transfer and the use of oxygen from air as an oxidizing agent in a bubble column. Systematic studies of the limiting hydrodynamic conditions in the ACP and the solid/liquid-separation of the photocatalyst from the treated wastewater have shown that the ACP is technically and commercially attractive. The ACP outperforms the thin-film fixed-bed reactor (TFFBR) with respect to a 3-13 times higher degradation efficiency for the model compound dichloroacetic acid (DCA). The treatment of two biologically pretreated real wastewaters, one from a textile factory and one from car-washing, have been successfully carried out under artificial light and sunlight.

  1. Communication Efficient Multi-processor FFT

    NASA Astrophysics Data System (ADS)

    Lennart Johnsson, S.; Jacquemin, Michel; Krawitz, Robert L.

    1992-10-01

    Computing the fast Fourier transform on a distributed memory architecture by a direct pipelined radix-2, a bi-section, or a multisection algorithm, all yield the same communications requirement, if communication for all FFT stages can be performed concurrently, the input data is in normal order, and the data allocation is consecutive. With a cyclic data allocation, or bit-reversed input data and a consecutive allocation, multi-sectioning offers a reduced communications requirement by approximately a factor of two. For a consecutive data allocation, normal input order, a decimation-in-time FFT requires that P/ N + d-2 twiddle factors be stored for P elements distributed evenly over N processors, and the axis that is subject to transformation be distributed over 2 d processors. No communication of twiddle factors is required. The same storage requirements hold for a decimation-in-frequency FFT, bit-reversed input order, and consecutive data allocation. The opposite combination of FFT type and data ordering requires a factor of log 2N more storage for N processors. The peak performance for a Connection Machine system CM-200 implementation is 12.9 Gflops/s in 32-bit precision, and 10.7 Gflops/s in 64-bit precision for unordered transforms local to each processor. The corresponding execution rates for ordered transforms are 11.1 Gflops/s and 8.5 Gflops/s, respectively. For distributed one- and two-dimensional transforms the peak performance for unordered transforms exceeds 5 Gflops/s in 32-bit precision and 3 Gflops/s in 64-bit precision. Three-dimensional transforms execute at a slightly lower rate. Distributed ordered transforms execute at a rate of about {1}/{2}to {2}/{3} of the unordered transforms.

  2. 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

  3. Dimethylformamide as a cryoprotectant for canine semen diluted and frozen in ACP-106C.

    PubMed

    Mota Filho, A C; Teles, C H A; Jucá, R P; Cardoso, J F S; Uchoa, D C; Campello, C C; Silva, A R; Silva, L D M

    2011-10-15

    The objective was to assess the effect of adding various concentrations of dimethylformamide on characteristics of canine semen diluted in powdered coconut water (ACP-106C; ACP Biotecnologia, Fortaleza, CE, Brazil) and frozen at -196°C. Fifteen ejaculates were collected by manual stimulation from five adult Boxer dogs. The sperm-rich fraction was diluted in ACP-106C (ACP Biotecnologia) containing 10% egg yolk and divided into four aliquots. The cryoprotectants used for each aliquot were 6% glycerol (control group; CG) or 2%, 4%, or 6% dimethylformamide (DF2, DF4, and DF6, respectively). After thawing, total motility (mean ± SEM) for CG (58.4 ± 24.6) was higher (P < 0.05) than that of the other groups (2% dimethylformamide, 24.4 ± 12.3; 4% dimethylformamide, 26.5 ± 16.1; and 6% dimethylformamide, 21.7 ± 17.9). Furthermore, there was a greater percentage of fast, average, and slow moving sperm (assessed with computer-aided semen analysis; CASA) in CG in comparison with the other three groups. Therefore, based on concentrations tested in this study, dimethylformamide, together with ACP-106C (ACP Biotecnologia) and 10% egg yolk as a diluent, yielded unsatisfactory in vitro results for freezing canine semen.

  4. Acalabrutinib (ACP-196) in Relapsed Chronic Lymphocytic Leukemia

    PubMed Central

    Byrd, John C; Harrington, Bonnie; O’Brien, Susan; Jones, Jeffrey A; Schuh, Anna; Devereux, Steve; Chaves, Jorge; Wierda, William G; Awan, Farrukh T; Brown, Jennifer R; Hillmen, Peter; Stephens, Deborah M; Ghia, Paolo; Barrientos, Jacqueline C; Pagel, John M; Woyach, Jennifer; Johnson, Dave; Huang, Jane; Wang, Xiaolin; Lannutti, Brian J; Covey, Todd; Fardis, Maria; McGreivy, Jesse; Hamdy, Ahmed; Rothbaum, Wayne; Izumi, Raquel; Diacovo, Thomas G; Johnson, Amy J; Furman, Richard R

    2016-01-01

    Background Irreversible inhibition of Bruton tyrosine kinase (Btk) by ibrutinib represents a significant therapeutic advance for chronic lymphocytic leukemia (CLL). However, ibrutinib also irreversibly inhibits alternative kinase targets, which potentially compromise its therapeutic index. Acalabrutinib (ACP-196) is a more selective irreversible Btk inhibitor specifically designed to improve upon the safety and efficacy of first generation Btk inhibitors. Methods Sixty-one patients with relapsed CLL were treated in a phase 1–2 multicenter study designed to assess the safety, efficacy, pharmacokinetics and pharmacodynamics of oral acalabrutinib. Patients were continuously treated with acalabrutinib 100 to 400 mg once daily in the dose-escalation portion of the study, and 100 mg twice daily in the expansion portion. Results Patient demographics include a median age of 62 years; median of 3 prior therapies; 31% del(17)(p13.1) and 75% unmutated immunoglobulin heavy chain variable genes. No dose-limiting toxicities occurred. The most common adverse events observed were headache (43%), diarrhea (39%) and increased weight (26%). Most adverse events were Grade 1–2. At a median follow-up of 14.3 months, the best overall response rate was 95%, including 85% partial response, 10% partial response with lymphocytosis and 5% stable disease. In patients with del(17)(p13.1), the best overall response was 100%. No cases of Richter’s transformation and only 1 CLL progression have occurred. Conclusions Acalabrutinib is a highly selective Btk inhibitor that provides effective and well tolerated treatment for patients with relapsed CLL, including those with del(17)(p13.1). PMID:26641137

  5. Utilizing a multiprocessor architecture - The performance of MIDAS

    SciTech Connect

    Maples, C.; Logan, D.; Meng, J.; Rathbun, W.; Weaver, D.

    1983-10-01

    The MIDAS architecture organizes multiple CPUs into clusters called distributed subsystems. Each subsystem consists of an array of processors controlled by a supervisory CPU. The multiprocessor array is composed of commercial CPUs (with floating point hardware) and specialized processing elements. Interprocessor communication within the array may occur either through switched memory modules or common shared memory. The architecture permits multiple processors to be focused on single problems. A distributed subsystem has been constructed and tested. It currently consists of a supervisor CPU; 16 blocks of independently switchable memory; 9 general purpose, VAX-class CPUs; and 2 specialized pipelined processors to handle I/O. Results on a variety of problems indicate that the subsystem performs 8 to 15 times faster than a standard computer with an identical CPU. The difference in performance represents the effect of differing CPU and I/O requirements.

  6. 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.

  7. Optically Connected Multiprocessors For Simulating Artificial Neural Networks

    NASA Astrophysics Data System (ADS)

    Ghosh, Joydeep; Hwang, Kai

    1988-05-01

    This paper investigates the architectural requirements in simulating large neural networks using a highly parallel multiprocessor with distributed memory and optical interconnects. First, we model the structure of a neural network and the functional behavior of individual cells. These models are used to estimate the volume of messages that need to be exchanged among physical processors to simulate the weighted connections of the neural network. The distributed processor/memory organization is tailored to an electronic implementation for greater versatility and flexibility. Optical interconnects are used to satisfy the interprocessor communication bandwidth demands. The hybrid implementation attempts to balance the processing, memory and bandwidth demands in simulating asynchronous, value-passing models for cooperative parallel computation with self-learning capabilities.

  8. Dynamic programming on a shared-memory multiprocessor

    NASA Technical Reports Server (NTRS)

    Edmonds, Phil; Chu, Eleanor; George, Alan

    1993-01-01

    Three new algorithms for solving dynamic programming problems on a shared-memory parallel computer are described. All three algorithms attempt to balance work load, while keeping synchronization cost low. In particular, for a multiprocessor having p processors, an analysis of the best algorithm shows that the arithmetic cost is O(n-cubed/6p) and that the synchronization cost is O(absolute value of log sub C n) if p much less than n, where C = (2p-1)/(2p + 1) and n is the size of the problem. The low synchronization cost is important for machines where synchronization is expensive. Analysis and experiments show that the best algorithm is effective in balancing the work load and producing high efficiency.

  9. Anatomy of the β-branching enzyme of polyketide biosynthesis and its interaction with an acyl-ACP substrate.

    PubMed

    Maloney, Finn P; Gerwick, Lena; Gerwick, William H; Sherman, David H; Smith, Janet L

    2016-09-13

    Alkyl branching at the β position of a polyketide intermediate is an important variation on canonical polyketide natural product biosynthesis. The branching enzyme, 3-hydroxy-3-methylglutaryl synthase (HMGS), catalyzes the aldol addition of an acyl donor to a β-keto-polyketide intermediate acceptor. HMGS is highly selective for two specialized acyl carrier proteins (ACPs) that deliver the donor and acceptor substrates. The HMGS from the curacin A biosynthetic pathway (CurD) was examined to establish the basis for ACP selectivity. The donor ACP (CurB) had high affinity for the enzyme (Kd = 0.5 μM) and could not be substituted by the acceptor ACP. High-resolution crystal structures of HMGS alone and in complex with its donor ACP reveal a tight interaction that depends on exquisite surface shape and charge complementarity between the proteins. Selectivity is explained by HMGS binding to an unusual surface cleft on the donor ACP, in a manner that would exclude the acceptor ACP. Within the active site, HMGS discriminates between pre- and postreaction states of the donor ACP. The free phosphopantetheine (Ppant) cofactor of ACP occupies a conserved pocket that excludes the acetyl-Ppant substrate. In comparison with HMG-CoA (CoA) synthase, the homologous enzyme from primary metabolism, HMGS has several differences at the active site entrance, including a flexible-loop insertion, which may account for the specificity of one enzyme for substrates delivered by ACP and the other by CoA.

  10. Recovery and cryopreservation of epididymal sperm from agouti (Dasiprocta aguti) using powdered coconut water (ACP-109c) and Tris extenders.

    PubMed

    Silva, M A; Peixoto, G C X; Santos, E A A; Castelo, T S; Oliveira, M F; Silva, A R

    2011-10-01

    The objective was to compare the use of powdered coconut water (ACP-109c; ACP Biotecnologia, Fortaleza, CE, Brazil) and Tris extenders for recovery and cryopreservation of epididymal sperm from agouti. The caudae epididymus and proximal ductus deferens from 10 sexually mature agoutis were subjected to retrograde washing using ACP-109c (ACP Biotecnologia) or Tris. Epididymal sperm were evaluated for motility, vigor, sperm viability, membrane integrity, and morphology. Samples were centrifuged, and extended in the same diluents plus egg yolk (20%) and glycerol (6%), frozen in liquid nitrogen, and subsequently thawed at 37°C for 1 min, followed by re-evaluation of sperm characteristics. The two extenders were similarly efficient for epididymal recovery, with regard to the number and quality of sperm recovered. However, for both extenders, sperm quality decreased (P < 0.05) after centrifugation and dilution. After sperm cryopreservation and thawing, there were (mean ± SEM) 26.5 ± 2.6% motile sperm with 2.6 ± 0.2 vigor in the ACP-109c (ACP Biotecnologia) group, which was significantly better than 9.7 ± 2.6% motile sperm with 1.2 ± 0.3 vigor in Tris. In conclusion, agouti epididymal sperm were successfully recovered using either ACP-109c (ACP Biotecnologia) or Tris extenders; however, ACP-109c (ACP Biotecnologia) was a significantly better extender for processing and cryopreserving these sperm.

  11. Anatomy of the β-branching enzyme of polyketide biosynthesis and its interaction with an acyl-ACP substrate.

    PubMed

    Maloney, Finn P; Gerwick, Lena; Gerwick, William H; Sherman, David H; Smith, Janet L

    2016-09-13

    Alkyl branching at the β position of a polyketide intermediate is an important variation on canonical polyketide natural product biosynthesis. The branching enzyme, 3-hydroxy-3-methylglutaryl synthase (HMGS), catalyzes the aldol addition of an acyl donor to a β-keto-polyketide intermediate acceptor. HMGS is highly selective for two specialized acyl carrier proteins (ACPs) that deliver the donor and acceptor substrates. The HMGS from the curacin A biosynthetic pathway (CurD) was examined to establish the basis for ACP selectivity. The donor ACP (CurB) had high affinity for the enzyme (Kd = 0.5 μM) and could not be substituted by the acceptor ACP. High-resolution crystal structures of HMGS alone and in complex with its donor ACP reveal a tight interaction that depends on exquisite surface shape and charge complementarity between the proteins. Selectivity is explained by HMGS binding to an unusual surface cleft on the donor ACP, in a manner that would exclude the acceptor ACP. Within the active site, HMGS discriminates between pre- and postreaction states of the donor ACP. The free phosphopantetheine (Ppant) cofactor of ACP occupies a conserved pocket that excludes the acetyl-Ppant substrate. In comparison with HMG-CoA (CoA) synthase, the homologous enzyme from primary metabolism, HMGS has several differences at the active site entrance, including a flexible-loop insertion, which may account for the specificity of one enzyme for substrates delivered by ACP and the other by CoA. PMID:27573844

  12. 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.

  13. 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.

  14. [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.

  15. [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

  16. 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

  17. 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

  18. 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

  19. 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.

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

    DOE PAGES

    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

  1. 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.

  2. 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.

  3. 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)

  4. Association of the acid phosphatase (ACP1) gene with triglyceride levels in obese women.

    PubMed

    Bottini, Nunzio; MacMurray, James; Peters, Warren; Rostamkhani, Masoud; Comings, David E

    2002-11-01

    The acid phosphatase (ACP1) locus codes for a low molecular weight protein tyrosine phosphatase (LMPTP) that is found ubiquitously in human tissues. The *A allele of the ACP1 gene is associated with lower total enzymatic activity than the *B and *C alleles. An association between the *A allele and extreme values of body-mass-index (BMI) and dyslipidemia has previously been described in several samples of obese subjects from the Italian population. In the present study, we investigated the relationship between ACP1 *A allele genotypes (*A/*A, *A/*B, and *A/*C) and non-*A allele genotypes (*B/*B, *B/*C, and *C/*C) and metabolic variables in 277 Caucasian post-menopausal subjects consisting of 82 non-obese subjects (BMI/=35) subjects. ACP1 genotypes were found to be significantly associated with total cholesterol (pACP1 *A allele may be partially protected against developing the metabolic syndrome. The confirmation of ACP1 as a modifier gene of the metabolic complications could open the door to the prevention of the lethal complications of obesity. PMID:12409270

  5. MASC: Multiprocessor Architecture for Symbolic Processing. Final report, March 1986-September 1988

    SciTech Connect

    Hopkins, W.C.; Blenko, T.M.; Cassell, K.; Clark, J.P.; Coltoff, J.B.

    1989-08-01

    The MASC program addresses the support of symbolic computation for Artificial Intelligence (AI), as part of the DARPA Strategic Computing Program. The work has been aimed at the fundamental questions of choosing an appropriate programming model for AI and finding efficient implementation techniques to support it on multiprocessor systems. The Strategic Computing Program is motivated by the need to provide real-time response by AI subsystems in planned or contemplated DoD systems. The authors efforts have directly supported this goal, contributing fundamental results in language design, language implementation, and application parallelism. The work has been driven by the needs of real AI applications, drawn from their substantial experience in natural language processing, knowledge representation, and expert systems. The technologies they have developed are broadly applicable, and several specific recommendations for their further development and application are presented. The most profound result is the design and demonstration of a powerful technique for the compilation of logic programs to applicative form. This brings the power of compilation and optimization techniques for functional programming to bear on logic programming languages. It is recommended that these technologies be extended and applied to current research efforts in language design for very-high-level programming and program prototyping. Other results and recommendations are contained in the body of the report.

  6. Design of a resource allocation and management mechanism for a multiprocessor

    SciTech Connect

    Lin, W.

    1985-01-01

    This work presents the design of a resource allocation and management mechanism for a multiprocessor, Star. The mechanism is designed for supporting highly parallel computation. Three major functions performed by the mechanism are: (1) resource allocation - for each task a suitable execution environment will be created, which contains an adequate number of processors, and these processors are reconfigured to achieve the desired topologies to match communication graph, (2) multitasking - several execution environments can be simultaneously created to execute different tasks on the system, and (3) distributed and structured management - the entire system can be dynamically partitioned into independent management entities, in each of which the resources are structured and managed in the form of objects, rather than individual system components. In addition, to demonstrate the effectiveness of the proposed mechanism, a simulation is performed to gather various statistics. With the simulation, the kind of space-dependent scheduling disciplines that can best match the proposed mechanism to achieve effective resource utilization can be examined.

  7. 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.

  8. 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.

  9. Restructuring symbolic programs for concurrent execution on multiprocessors

    SciTech Connect

    Larus, J.R.

    1989-01-01

    CURARE, the program restructurer described in this dissertation, automatically transforms a sequential Lisp program into an equivalent concurrent program that executes on a multiprocessor. CURARE first analyzes a program to find its control and data dependences. This analysis is most difficult for references to structures connected by pointers. CURARE uses a new data-dependence algorithm, which finds and classifies these dependences. The analysis is conservative and may detect conflicts that do not arise in practice. A programmer can temper and refine its results with declarations. Dependences constrain the program's concurrent execution because, in general, two conflicting statements cannot execute in a different order without affecting the program's result. A restructurer must know all dependences in order to preserve them. However, not all dependences are essential to produce the program's result. CURARE attempts to transform the program so it computes its result with fewer conflicts. An optimized program will execute with less synchronization and more concurrency. CURARE then examines loops in a program to find those that are unconstrained or lightly constrained by dependences. By necessity, CURARE treats recursive functions as loops and does not limit itself to explicit program loops. Recursive functions offer several advantages over explicit loops since they provide a convenient framework for inserting locks and handling the dynamic behavior of symbolic programs. Loops that are suitable for concurrent execution are changed to execute on a set of concurrent server processes. These servers execute single loop iterations and therefore need to be extremely inexpensive to invoke.

  10. 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.

  11. 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.

  12. Trajectory optimization on multiprocessors - A comparison of three implementation strategies

    NASA Astrophysics Data System (ADS)

    Summerset, Twain K.; Chowkwanyun, Raymond M.

    The optimization of atmospheric flight vehicle trajectories can require the simulation of several thousand individual trajectories. Such a task can be extremely time consuming if simulating each trajectory requires numerically integrating a set of nonlinear differential equations. This traditional approach, which may require many hours' worth of analysis on a time-shared computer facility, is a bottleneck in space mission planning and limits the number of trajectory design options a mission planner can evaluate. To achieve marked reductions in trajectory design solution times, parallel optimization techniques are proposed. In this paper, three strategies for implementing trajectory optimization methods on multiprocessors will be compared. The comparisons will be illustrated through four trajectory design examples. In the first two examples, maximum reentry downrange and crossrange optimal control problems are posed for a generic maneuvering aerodynamic space vehicle. The third example is Troesch's problem, while the fourth example is the classic Brachistochrone problem. Each of the examples are posed as two-point boundary value problems whose solutions can be expressed as the solutions to a set of nonlinear equations.

  13. 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

  14. [Frequencies of red cell enzyme polymorphisms acP, ADA, AK, EsD, 6-PGD, and PGM1 determined by parallel investigations of Turks and Germans living in the Lübeck area (author's transl)].

    PubMed

    Weissmann, J; Oepen, B; Pribilla, O

    1980-01-01

    Gene frequencies for enzyme polymorphisms in the acP, ADA, AK, EsD, 6-PGD, and PGM1 systems were determined by a random sample (n = 281-556-575) Turks living in Lübeck. The results were compared with those of a parallel inquiry on Germans from Lübeck. The following gene frequencies were detected: (table: see text).

  15. The Performance of Parallel Disk Write Methods for Linux Multiprocessor Nodes

    SciTech Connect

    Benson, G D; Long, K; Pacheco, P

    2003-05-07

    Despite increasing attention paid to parallel I/O and the introduction of MPI-IO, there is limited, practical data to help guide a programmer in the choice of a good parallel write strategy in the absence of a parallel file system. In this study we experimentally evaluate several methods for implementing parallel computations that interleave a significant number of contiguous or strided writes to a local disk on Linux-based multiprocessor nodes. Using synthetic benchmark programs written with MPI and Pthreads, we have acquired detailed performance data for different application characteristics of programs running on dual processor nodes. In general, our results show that programs that perform a significant amount of I/O relative to pure computation benefit greatly from the use of threads, while programs that perform relatively little I/O obtain excellent results using only MPI. For a pure MPI approach, we have found that it is best to use two writing processes with mmap(). For Pthreads it is usually best to use write() for contiguous data and writev() for strided data. Codes that use mmap() tend to benefit from periodic syncs of the data of the data to the disk, while codes that use write() or writev() tend to have better performance with few syncs. A straightforward use of ROMIO usually does not perform as well as these direct approaches for writing to the local disk.

  16. 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.

  17. 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.

  18. 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).

  19. 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

  20. 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.

  1. Hyaluronic acid auto-crosslinked polymer (ACP): Reaction monitoring, process investigation and hyaluronidase stability.

    PubMed

    Pluda, Stefano; Pavan, Mauro; Galesso, Devis; Guarise, Cristian

    2016-10-01

    Hyaluronic Acid (HA) is a non-sulphated glycosaminoglycan that, despite its high molecular weight, is soluble in water and is not resistant to enzymatic degradation, the latter of which hinders its wider application as a biomedical material. Auto-crosslinked polymer (ACP) gels of HA are fully biocompatible hydrogels that exhibit improved viscoelastic properties and prolonged in vivo residence times compared to the native polymer. Crosslinking is achieved through a base-catalysed reaction consisting of the activation of HA carboxyl groups by 2-chloro-1-methylpyridinium iodide (CMPI) and subsequent nucleophilic acyl substitution by the hydroxyl groups of HA in organic solvent. In this study, a number of ACP hydrogels have been obtained via reactions using varying ratios of CMPI to HA. The crosslinking reaction was monitored by rheological measurements in organic solvents during CMPI addition to the reaction mixture. The ACP intermediates, powders and hydrogels were characterized, helping to elucidate the crosslinking process. A two-step mechanism was proposed to explain the observed trends in viscosity and particle size. Syntheses were carried out by varying the reaction temperature, respectively at 0 °C, 25 °C and 45 °C in N-Methyl-2-Pyrrolidone (NMP), as well as the solvent respectively in NMP, DMSO and DMF at 25 °C. Interestingly, varying these parameters did not substantially affect the degree of crosslinking but likely did influence the intra/inter-molecular crosslinking ratio and, therefore, the viscoelastic properties. A wide range of crosslinking densities was confirmed through ESEM analysis. Finally, a comparative hyaluronidase degradation assay revealed that the ACPs exhibited a higher resistance toward enzymatic cleavage at low elastic modulus compared to other more chemically resistant, crosslinked HAs. These observations demonstrated the importance of crosslinking density of matrix structures on substrate availability. PMID:27442913

  2. 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.

  3. Intravaginal artificial insemination in bitches using frozen/thawed semen after dilution in powdered coconut water (ACP-106c).

    PubMed

    Uchoa, D C; Silva, T F P; Mota Filho, A C; Silva, L D M

    2012-12-01

    The aim of this study was to evaluate powdered coconut water extender (ACP-106c; ACP Serviços Tecnológicos Ltda, ACP Biotecnologia, Fortaleza, Ceará, Brazil) as a diluent for freezing dog semen and the fertility after vaginal insemination of semen frozen therein. Ten ejaculates were collected from five dogs, evaluated fresh, diluted in ACP-106c, 10% egg yolk and 6% glycerol, cooled and frozen. In the first phase of the study, straws with frozen semen were thawed and immediately subjected to the same analysis as the fresh semen and, in addition, to Computer-Assisted Semen Analysis (CASA). In phase 2, 10 bitches that had been subjected to natural breeding during a preceding oestrous cycle were vaginally inseminated with thawed semen that had been re-diluted in ACP-106c. After thawing, a mean of 77% sperm motility was obtained through subjective analysis and 77.3% through CASA. Following artificial insemination, a 60% pregnancy rate was observed, resulting in a 50% parturition rate and a mean litter size of 3.4 (SEM 0.6), with 47.1% males and 52.9% females. ACP-106c can be successfully used for freezing canine semen, and vaginal deposition of such semen yields similar pregnancy rates to those reported in other studies.

  4. 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.

  5. 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

  6. Synchronous multi-microprocessor system for implementing digital signal processing algorithms

    SciTech Connect

    Barnwell, T.P. III; Hodges, C.J.M.

    1982-01-01

    This paper discusses the details of a multi-microprocessor system design as a research facility for studying multiprocessor implementation of digital signal processing algorithms. The overall system, which consists of a control microprocessor, eight satellite microprocessors, a control minicomputer, and extensive distributed software, has proven to be an effect tool in the study of multiprocessor implementations. 5 references.

  7. 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.

  8. 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.

  9. 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.

  10. Inhibition and covalent modification of rape seed (Brassica napus) enoyl ACP reductase by phenylglyoxal.

    PubMed

    Cottingham, I R; Austin, A J; Slabas, A R

    1989-05-01

    The NADH-dependent enoyl-ACP reductase from oil seed rape (Brassica napus) was inactivated by treatment with phenylglyoxal, a reagent which specifically modifies arginine residues. The inhibition at various phenylglyoxal concentrations shows pseudo-first-order kinetics, with an apparent second-order rate constant of 14.2 M-1.min-1 for inactivation. The protective ability of several substrates and substrate analogues was investigated in order to ascertain if the inhibition was directed towards the active site of the enzyme. NADH and NAD+ did not protect but acyl carrier protein (ACP) and reduced coenzyme A, along with various derivatives, did protect. 9 microM ACP gave 35% protection from inactivation and 10 mM reduced coenzyme A gave 98% protection. The effectiveness of various subfragments of coenzyme A in protecting against inhibition indicates that the phosphate group is essential for preventing the binding of phenylglyoxal. The idea that phenylglyoxal is inhibiting by binding at the active site is further supported by the observation that the incorporation of 14C-labelled phenylglyoxal is directly related to the loss of activity. Extrapolation of the amount of label incorporated to give total inhibition shows that 4 mol of phenylglyoxal would be incorporated per mol of enzyme. This corresponds to the modification of two arginine side-chains with equal reactiveness towards the reagent. These results are consistent with there being two arginine residues either at the active site of the enzyme or in an environment which is protected from phenylglyoxal by a conformational change induced by coenzyme A binding.

  11. Protective effect of calcium nanophosphate and CPP-ACP agents on enamel erosion.

    PubMed

    Carvalho, Fabíola Galbiatti de; Brasil, Veruska Lima Moura; Silva Filho, Tiago João da; Carlo, Hugo Lemes; Santos, Rogério Lacerda dos; Lima, Bruno Alessandro Silva Guedes de

    2013-01-01

    The aim of this study was to assess the effect of different remineralizing agents on enamel microhardness (KHN) and surface topography after an erosive challenge. Forty-eight human enamel specimens (4 × 4 mm) were randomly assigned to 4 groups: control (no treatment), fluoride varnish, calcium nanophosphate paste and casein phosphopeptide-amorphous calcium phosphate paste (CPP-ACP). Both pastes were applied for 5 minutes, and fluoride varnish, for 24 h. Four daily erosive cycles of 5 minutes of immersion in a cola drink and 2 h in artificial saliva were conducted for 5 days. KHN readings were performed at baseline and after 5 days. The percentage of enamel hardness change (%KHN) was obtained after erosion. The surface topography was evaluated by atomic force microscopy (AFM). The data were tested using ANOVA, Tukey's and paired-T tests (p < 0.05). After an erosive challenge, there was no statistically significant difference between the control (96.8 ± 11.4 KHN / 72.4 ± 3.0%KHN) and the varnish (91.7 ± 14.1 KHN / 73.4 ± 5.5%KHN) groups. The nanophosphate group showed lower enamel hardness loss (187.2 ± 27.9 / 49.0 ± 7.9%KHN), compared with the CPP-ACP group (141.8 ± 16.5 / 60.6 ± 4.0%KHN), and both were statistically different from the varnish and the control groups. AFM images showed a rough surface for the control and the varnish groups, a non-homogeneous layer with globular irregularities for CPP-ACP, and a thick homogeneous layer for the nanophosphate group. None of the agents provided protection against the development of erosion; however, nanophosphate paste was able to reduce enamel surface softening after the erosive challenge.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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

  17. Isolation and characterization of a cDNA from Cuphea lanceolata encoding a beta-ketoacyl-ACP reductase.

    PubMed

    Klein, B; Pawlowski, K; Höricke-Grandpierre, C; Schell, J; Töpfer, R

    1992-05-01

    A cDNA encoding beta-ketoacyl-ACP reductase (EC 1.1.1.100), an integral part of the fatty acid synthase type II, was cloned from Cuphea lanceolata. This cDNA of 1276 bp codes for a polypeptide of 320 amino acids with 63 N-terminal residues presumably representing a transit peptide and 257 residues corresponding to the mature protein of 27 kDa. The encoded protein shows strong homology with the amino-terminal sequence and two tryptic peptides from avocado mesocarp beta-ketoacyl-ACP reductase, and its total amino acid composition is highly similar to those of the beta-ketoacyl-ACP reductases of avocado and spinach. Amino acid sequence homologies to polyketide synthase, beta-ketoreductases and short-chain alcohol dehydrogenases are discussed. An engineered fusion protein lacking most of the transit peptide, which was produced in Escherichia coli, was isolated and proved to possess beta-ketoacyl-ACP reductase activity. Hybridization studies revealed that in C. lanceolata beta-ketoacyl-ACP reductase is encoded by a small family of at least two genes and that members of this family are expressed in roots, leaves, flowers and seeds.

  18. 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

  19. 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.

  20. 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.

  1. 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

  2. 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

  3. A multitasking, multisinked, multiprocessor data acquisition front end

    SciTech Connect

    Fox, R.; Au, R.; Molen, A.V. . Cyclotron Lab.)

    1989-10-01

    The authors have developed a generalized data acquisition front end system which is based on MC68020 processors running a commercial real time kernel (rhoSOS), and implemented primarily in a high level language (C). This system has been attached to the back end on-line computing system at NSCL via our high performance ETHERNET protocol. Data may be simultaneously sent to any number of back end systems. Fixed fraction sampling along links to back end computing is also supported. A nonprocedural program generator simplifies the development of experiment specific code.

  4. 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

  5. Multiprogramming performance degradation - Case study on a shared memory multiprocessor

    NASA Technical Reports Server (NTRS)

    Dimpsey, R. T.; Iyer, R. K.

    1989-01-01

    The performance degradation due to multiprogramming overhead is quantified for a parallel-processing machine. Measurements of real workloads were taken, and it was found that there is a moderate correlation between the completion time of a program and the amount of system overhead measured during program execution. Experiments in controlled environments were then conducted to calculate a lower bound on the performance degradation of parallel jobs caused by multiprogramming overhead. The results show that the multiprogramming overhead of parallel jobs consumes at least 4 percent of the processor time. When two or more serial jobs are introduced into the system, this amount increases to 5.3 percent

  6. Speedup of linear stationary iteration processes in multiprocessor computers. I

    SciTech Connect

    Romm, Ya.E.

    1982-01-01

    The author considers two forms of stationary iteration process. Conditions are discussed under which the simpler process is slower than the other one on a multiprocessing computer, for the same method error. Estimates of the number of processors and the computation time are compared. Results are applied to Jacobi's method of solving systems of linear algebraic equations. 27 references.

  7. Role of Serine140 in the mode of action of Mycobacterium tuberculosis β-ketoacyl-ACP Reductase (MabA)

    PubMed Central

    2012-01-01

    Background Tuberculosis (TB) still remains one of the most deadly infectious diseases in the world. Mycobacterium tuberculosis β-ketoacyl-ACP Reductase (MabA) is a member of the fatty acid elongation system type II, providing precursors of mycolic acids that are essential to the bacterial cell growth and survival. MabA has been shown to be essential for M. tuberculosis survival and to play a role in intracellular signal transduction of bacilli. Findings Here we describe site-directed mutagenesis, recombinant protein expression and purification, steady-state kinetics, fluorescence spectroscopy, and molecular modeling for S140T and S140A mutant MabA enzymes. No enzyme activity could be detected for S140T and S140A. Although the S140T protein showed impaired NADPH binding, the S140A mutant could bind to NADPH. Computational predictions for NADPH binding affinity to WT, S140T and S140A MabA proteins were consistent with fluorescence spectroscopy data. Conclusions The results suggest that the main role of the S140 side chain of MabA is in catalysis. The S140 side chain appears to also play an indirect role in NADPH binding. Interestingly, NADPH titrations curves shifted from sigmoidal for WT to hyperbolic for S140A, suggesting that the S140 residue may play a role in displacing the pre-existing equilibrium between two forms of MabA in solution. The results here reported provide a better understanding of the mode of action of MabA that should be useful to guide the rational (function-based) design of inhibitors of MabA enzyme activity which, hopefully, could be used as lead compounds with anti-TB action. PMID:23006410

  8. 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.

  9. Highway traffic simulation on multi-processor computers

    SciTech Connect

    Hanebutte, U.R.; Doss, E.; Tentner, A.M.

    1997-04-01

    A computer model has been developed to simulate highway traffic for various degrees of automation with a high level of fidelity in regard to driver control and vehicle characteristics. The model simulates vehicle maneuvering in a multi-lane highway traffic system and allows for the use of Intelligent Transportation System (ITS) technologies such as an Automated Intelligent Cruise Control (AICC). The structure of the computer model facilitates the use of parallel computers for the highway traffic simulation, since domain decomposition techniques can be applied in a straight forward fashion. In this model, the highway system (i.e. a network of road links) is divided into multiple regions; each region is controlled by a separate link manager residing on an individual processor. A graphical user interface augments the computer model kv allowing for real-time interactive simulation control and interaction with each individual vehicle and road side infrastructure element on each link. Average speed and traffic volume data is collected at user-specified loop detector locations. Further, as a measure of safety the so- called Time To Collision (TTC) parameter is being recorded.

  10. Error recovery in shared memory multiprocessors using private caches

    NASA Technical Reports Server (NTRS)

    Wu, Kun-Lung; Fuchs, W. Kent; Patel, Janak H.

    1990-01-01

    The problem of recovering from processor transient faults in shared memory multiprocesses systems is examined. A user-transparent checkpointing and recovery scheme using private caches is presented. Processes can recover from errors due to faulty processors by restarting from the checkpointed computation state. Implementation techniques using checkpoint identifiers and recovery stacks are examined as a means of reducing performance degradation in processor utilization during normal execution. This cache-based checkpointing technique prevents rollback propagation, provides rapid recovery, and can be integrated into standard cache coherence protocols. An analytical model is used to estimate the relative performance of the scheme during normal execution. Extensions to take error latency into account are presented.

  11. 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

  12. 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

  13. 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.

  14. 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.

  15. SYMNET: an optical interconnection network for scalable high-performance symmetric multiprocessors.

    PubMed

    Louri, Ahmed; Kodi, Avinash Karanth

    2003-06-10

    We address the primary limitation of the bandwidth to satisfy the demands for address transactions in future cache-coherent symmetric multiprocessors (SMPs). It is widely known that the bus speed and the coherence overhead limit the snoop/address bandwidth needed to broadcast address transactions to all processors. As a solution, we propose a scalable address subnetwork called symmetric multiprocessor network (SYMNET) in which address requests and snoop responses of SMPs are implemented optically. SYMNET not only has the ability to pipeline address requests, but also multiple address requests from different processors can propagate through the address subnetwork simultaneously. This is in contrast with all electrical bus-based SMPs, where only a single request is broadcast on the physical address bus at any given point in time. The simultaneous propagation of multiple address requests in SYMNET increases the available address bandwidth and lowers the latency of the network, but the preservation of cache coherence can no longer be maintained with the usual fast snooping protocols. A modified snooping cache-coherence protocol, coherence in SYMNET (COSYM) is introduced to solve the coherence problem. We evaluated SYMNET with a subset of Splash-2 benchmarks and compared it with the electrical bus-based MOESI (modified, owned, exclusive, shared, invalid) protocol. Our simulation studies have shown a 5-66% improvement in execution time for COSYM as compared with MOESI for various applications. Simulations have also shown that the average latency for a transaction to complete by use of COSYM protocol was 5-78% better than the MOESI protocol. SYMNET can scale up to hundreds of processors while still using fast snooping-based cache-coherence protocols, and additional performance gains may be attained with further improvement in optical device technology.

  16. Use of a genetic algorithm to solve two-fluid flow problems on an NCUBE multiprocessor computer

    SciTech Connect

    Pryor, R.J.; Cline, D.D.

    1992-01-01

    A method of solving the two-phase fluid flow equations using a genetic algorithm on a NCUBE multiprocessor computer is presented. The topics discussed are the two-phase flow equations, the genetic representation of the unknowns, the fitness function, the genetic operators, and the implementation of the algorithm on the NCUBE computer. The efficiency of the implementation is investigated using a pipe blowdown problem. Effects of varying the genetic parameters and the number of processors are presented.

  17. Use of a genetic algorithm to solve two-fluid flow problems on an NCUBE multiprocessor computer

    SciTech Connect

    Pryor, R.J.; Cline, D.D.

    1992-12-31

    A method of solving the two-phase fluid flow equations using a genetic algorithm on a NCUBE multiprocessor computer is presented. The topics discussed are the two-phase flow equations, the genetic representation of the unknowns, the fitness function, the genetic operators, and the implementation of the algorithm on the NCUBE computer. The efficiency of the implementation is investigated using a pipe blowdown problem. Effects of varying the genetic parameters and the number of processors are presented.

  18. Effect of CPP-ACP on the remineralization of acid-eroded human tooth enamel: nanomechanical properties and microtribological behaviour study

    NASA Astrophysics Data System (ADS)

    Zheng, L.; Zheng, J.; Zhang, Y. F.; Qian, L. M.; Zhou, Z. R.

    2013-10-01

    Casein phosphopeptide-stabilized amorphous calcium phosphate (CPP-ACP) has been used to enhance tooth remineralization in the dental clinic. But the contribution of CPP-ACP to the remineralization of acid-eroded human tooth enamel is of widespread controversy. To confirm the application potential of CPP-ACP in the remineralization repair of tooth erosion caused by acid-attack, the effect of remineralization in vitro in 2% w/v CPP-ACP solution on the acid-eroded human tooth enamel was investigated in this study. The repair of surface morphology and the improvement of nanomechanical and microtribological properties were characterized with laser confocal scanning microscope, scanning electron microscope, nanoindentation tester and nanoscratch tester. Results showed that a layer of uneven mineral deposits, which were mainly amorphous calcium phosphate (ACP) in all probability, was observed on the acid-eroded enamel surface after remineralization. Compared with the acid-eroded enamel surface, the nanoindentation hardness and Young's modulus of the remineralized enamel surface obviously increased. Both the friction coefficient and wear volume of the acid-eroded enamel surface decreased after remineralization. However, both the nanomechanical and the anti-wear properties of the remineralized enamel surface were still inferior to those of original enamel surface. In summary, tooth damage caused by acid erosion could be repaired by remineralization in CPP-ACP solution, but the repair effect, especially on the nanomechanical and anti-wear properties of the acid-eroded enamel, was limited. These results would contribute to a further exploration of the remineralization potential of CPP-ACP and a better understanding of the remineralization repair mechanism for acid-eroded human tooth enamel.

  19. 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 PAGES

    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

  20. 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.

  1. Use of a genetic algorithm to solve fluid flow problems on an NCUBE/2 multiprocessor computer

    SciTech Connect

    Pryor, R.J.; Cline, D.D.

    1992-04-01

    This paper presents a method to solve partial differential equations governing two-phase fluid flow by using a genetic algorithm on the NCUBE/2 multiprocessor computer. Genetic algorithms represent a significant departure from traditional approaches of solving fluid flow problems. The inherent parallelism of genetic algorithms offers the prospect of obtaining solutions faster than ever possible. The paper discusses the two-phase flow equations, the genetic representation of the unknowns, the fitness function, the genetic operators, and the implementation of the genetic algorithm on the NCUBE/2 computer. The paper investigates the implementation efficiency using a pipe blowdown test and presents the effects of varying both the genetic parameters and the number of processors. The results show that genetic algorithms provide a major advancement in methods for solving two-phase flow problems. A desired goal of solving these equations for a specific simulation problem in real time or faster requires computers with an order of magnitude more processors or faster than the NCUBE/2's 1024.

  2. Use of a genetic algorithm to solve fluid flow problems on an NCUBE/2 multiprocessor computer

    SciTech Connect

    Pryor, R.J.; Cline, D.D.

    1992-04-01

    This paper presents a method to solve partial differential equations governing two-phase fluid flow by using a genetic algorithm on the NCUBE/2 multiprocessor computer. Genetic algorithms represent a significant departure from traditional approaches of solving fluid flow problems. The inherent parallelism of genetic algorithms offers the prospect of obtaining solutions faster than ever possible. The paper discusses the two-phase flow equations, the genetic representation of the unknowns, the fitness function, the genetic operators, and the implementation of the genetic algorithm on the NCUBE/2 computer. The paper investigates the implementation efficiency using a pipe blowdown test and presents the effects of varying both the genetic parameters and the number of processors. The results show that genetic algorithms provide a major advancement in methods for solving two-phase flow problems. A desired goal of solving these equations for a specific simulation problem in real time or faster requires computers with an order of magnitude more processors or faster than the NCUBE/2`s 1024.

  3. 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.

  4. Comparing the Effects of Whey Extract and Casein Phosphopeptide-Amorphous Calcium Phosphate (CPP-ACP) on Enamel Microhardness

    PubMed Central

    Rezvani, Mohammad Bagher; Karimi, Mehrdad; Akhavan Rasoolzade, Raheleh; Haghgoo, Roza

    2015-01-01

    Statement of the Problem With the recent focus of researches on the development of non-invasive treatment modalities, the non-invasive treatment of early carious lesions by remineralization would bring a major advance in the clinical management of these dental defects. Casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) is considered to be effective in tooth remineralization. Purpose The aim of this in-vitro study was to compare the effects of whey and CPP-ACP in increasing the enamel microhardness. Materials and Method Microhardness of 30 sound human permanent premolars was measured before and after 8-minute immersion of samples in Coca-Cola. The teeth were then randomly divided into 3 groups and were immersed in artificial saliva, whey, and tooth mousse for 10 minutes. The changes of microhardness within each group and among the groups were recorded and analyzed using paired t-test. Results The microhardness increased in each group and between the groups; this increase was statistically significant (p= 0.009). Conclusion The effect of whey on increasing the enamel microhardness was more than that of tooth mousse. PMID:25759858

  5. 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

  6. 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.

  7. Computational design of RNA parts, devices, and transcripts with kinetic folding algorithms implemented on multiprocessor clusters.

    PubMed

    Thimmaiah, Tim; Voje, William E; Carothers, James M

    2015-01-01

    With progress toward inexpensive, large-scale DNA assembly, the demand for simulation tools that allow the rapid construction of synthetic biological devices with predictable behaviors continues to increase. By combining engineered transcript components, such as ribosome binding sites, transcriptional terminators, ligand-binding aptamers, catalytic ribozymes, and aptamer-controlled ribozymes (aptazymes), gene expression in bacteria can be fine-tuned, with many corollaries and applications in yeast and mammalian cells. The successful design of genetic constructs that implement these kinds of RNA-based control mechanisms requires modeling and analyzing kinetically determined co-transcriptional folding pathways. Transcript design methods using stochastic kinetic folding simulations to search spacer sequence libraries for motifs enabling the assembly of RNA component parts into static ribozyme- and dynamic aptazyme-regulated expression devices with quantitatively predictable functions (rREDs and aREDs, respectively) have been described (Carothers et al., Science 334:1716-1719, 2011). Here, we provide a detailed practical procedure for computational transcript design by illustrating a high throughput, multiprocessor approach for evaluating spacer sequences and generating functional rREDs. This chapter is written as a tutorial, complete with pseudo-code and step-by-step instructions for setting up a computational cluster with an Amazon, Inc. web server and performing the large numbers of kinefold-based stochastic kinetic co-transcriptional folding simulations needed to design functional rREDs and aREDs. The method described here should be broadly applicable for designing and analyzing a variety of synthetic RNA parts, devices and transcripts.

  8. 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.

  9. Cloning of acyl-ACP thioesterase FatA from Arachis hypogaea L. and its expression in Escherichia coli.

    PubMed

    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.

  10. 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

  11. QSAR and Molecular Docking Studies of Oxadiazole-Ligated Pyrrole Derivatives as Enoyl-ACP (CoA) Reductase Inhibitors

    PubMed Central

    Asgaonkar, Kalyani D.; Mote, Ganesh D.; Chitre, Trupti S.

    2014-01-01

    A quantitative structure-activity relationship model was developed on a series of compounds containing oxadiazole-ligated pyrrole pharmacophore to identify key structural fragments required for anti-tubercular activity. Two-dimensional (2D) and three-dimensional (3D) QSAR studies were performed using multiple linear regression (MLR) analysis and k-nearest neighbour molecular field analysis (kNN-MFA), respectively. The developed QSAR models were found to be statistically significant with respect to training, cross-validation, and external validation. New chemical entities (NCEs) were designed based on the results of the 2D- and 3D-QSAR. NCEs were subjected to Lipinski’s screen to ensure the drug-like pharmacokinetic profile of the designed compounds in order to improve their bioavailability. Also, the binding ability of the NCEs with enoyl-ACP (CoA) reductase was assessed by docking. PMID:24634843

  12. 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

  13. 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.

  14. Early-onset obesity and paternal 2pter deletion encompassing the ACP1, TMEM18, and MYT1L genes

    PubMed Central

    Doco-Fenzy, Martine; Leroy, Camille; Schneider, Anouck; Petit, Florence; Delrue, Marie-Ange; Andrieux, Joris; Perrin-Sabourin, Laurence; Landais, Emilie; Aboura, Azzedine; Puechberty, Jacques; Girard, Manon; Tournaire, Magali; Sanchez, Elodie; Rooryck, Caroline; Ameil, Agnès; Goossens, Michel; Jonveaux, Philippe; Lefort, Geneviève; Taine, Laurence; Cailley, Dorothée; Gaillard, Dominique; Leheup, Bruno; Sarda, Pierre; Geneviève, David

    2014-01-01

    Obesity is a common but highly, clinically, and genetically heterogeneous disease. Deletion of the terminal region of the short arm of chromosome 2 is rare and has been reported in about 13 patients in the literature often associated with a Prader–Willi-like phenotype. We report on five unrelated patients with 2p25 deletion of paternal origin presenting with early-onset obesity, hyperphagia, intellectual deficiency, and behavioural difficulties. Among these patients, three had de novo pure 2pter deletions, one presented with a paternal derivative der(2)t(2;15)(p25.3;q26) with deletion in the 2pter region and the last patient presented with an interstitial 2p25 deletion. The size of the deletions was characterized by SNP array or array-CGH and was confirmed by fluorescence in situ hybridization (FISH) studies. Four patients shared a 2p25.3 deletion with a minimal critical region estimated at 1.97 Mb and encompassing seven genes, namely SH3HYL1, ACP1, TMEMI8, SNTG2, TPO, PXDN, and MYT1L genes. The fifth patient had a smaller interstitial deletion encompassing the TPO, PXDN, and MYT1L genes. Paternal origin of the deletion was determined by genotyping using microsatellite markers. Analysis of the genes encompassed in the deleted region led us to speculate that the ACP1, TMEM18, and/or MYT1L genes might be involved in early-onset obesity. In addition, intellectual deficiency and behavioural troubles can be explained by the heterozygous loss of the SNTG2 and MYT1L genes. Finally, we discuss the parent-of-origin of the deletion. PMID:24129437

  15. Early-onset obesity and paternal 2pter deletion encompassing the ACP1, TMEM18, and MYT1L genes.

    PubMed

    Doco-Fenzy, Martine; Leroy, Camille; Schneider, Anouck; Petit, Florence; Delrue, Marie-Ange; Andrieux, Joris; Perrin-Sabourin, Laurence; Landais, Emilie; Aboura, Azzedine; Puechberty, Jacques; Girard, Manon; Tournaire, Magali; Sanchez, Elodie; Rooryck, Caroline; Ameil, Agnès; Goossens, Michel; Jonveaux, Philippe; Lefort, Geneviève; Taine, Laurence; Cailley, Dorothée; Gaillard, Dominique; Leheup, Bruno; Sarda, Pierre; Geneviève, David

    2014-04-01

    Obesity is a common but highly, clinically, and genetically heterogeneous disease. Deletion of the terminal region of the short arm of chromosome 2 is rare and has been reported in about 13 patients in the literature often associated with a Prader-Willi-like phenotype. We report on five unrelated patients with 2p25 deletion of paternal origin presenting with early-onset obesity, hyperphagia, intellectual deficiency, and behavioural difficulties. Among these patients, three had de novo pure 2pter deletions, one presented with a paternal derivative der(2)t(2;15)(p25.3;q26) with deletion in the 2pter region and the last patient presented with an interstitial 2p25 deletion. The size of the deletions was characterized by SNP array or array-CGH and was confirmed by fluorescence in situ hybridization (FISH) studies. Four patients shared a 2p25.3 deletion with a minimal critical region estimated at 1.97 Mb and encompassing seven genes, namely SH3HYL1, ACP1, TMEMI8, SNTG2, TPO, PXDN, and MYT1L genes. The fifth patient had a smaller interstitial deletion encompassing the TPO, PXDN, and MYT1L genes. Paternal origin of the deletion was determined by genotyping using microsatellite markers. Analysis of the genes encompassed in the deleted region led us to speculate that the ACP1, TMEM18, and/or MYT1L genes might be involved in early-onset obesity. In addition, intellectual deficiency and behavioural troubles can be explained by the heterozygous loss of the SNTG2 and MYT1L genes. Finally, we discuss the parent-of-origin of the deletion.

  16. A functional analysis of ACP-20, an adult-specific cuticular protein gene from the beetle Tenebrio: role of an intronic sequence in transcriptional activation during the late metamorphic period.

    PubMed

    Lemoine, A; Mathelin, J; Braquart-Varnier, C; Everaerts, C; Delachambre, J

    2004-10-01

    A gene encoding the adult cuticular protein ACP-20 was isolated in Tenebrio. It consists of three exons interspersed by two introns, intron 1 interrupting the signal peptide. To understand the regulatory mechanisms of ACP-20 expression, ACP-20 promoter-luciferase reporter gene constructs were transfected into cultured pharate adult wing epidermis. Transfection assays needed the presence of 20-hydroxyecdysone, confirming that ACP-20 is up-regulated by ecdysteroids. Analysis of 5' deletion constructs revealed that three regions are necessary for high levels of transcription. Interaction experiments between intronic fragments and epidermal nuclear proteins confirmed the importance of intron 1 in ACP-20 transcriptional control, which results from the combined activity of regulatory cis-acting elements of the promoter and those of intron 1.

  17. 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.

  18. 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…

  19. 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…

  20. 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…

  1. 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 …

  2. 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

  3. 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…

  4. Intelligent computational systems for space applications

    NASA Technical Reports Server (NTRS)

    Lum, Henry, Jr.; Lau, Sonie

    1989-01-01

    The evolution of intelligent computation systems is discussed starting with the Spaceborne VHSIC Multiprocessor System (SVMS). The SVMS is a six-processor system designed to provide at least a 100-fold increase in both numeric and symbolic processing over the i386 uniprocessor. The significant system performance parameters necessary to achieve the performance increase are discussed.

  5. 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.

  6. Multiprocessor position/velocity servo control for multiaxis digital robot control system

    SciTech Connect

    Lancraft, R.E.; Daggett, K.E.; Omaga, E.M.; Casler, R.J. Jr.; Booth, B.L.; Bergman, N.J.; Nuncy, M.D.

    1989-09-19

    This paper describes a digitally controlled robot. It comprises: an arm having a plurality of joints; each of the joints being axis driven by an electric motor drive; a power amplifier operable to supply drive current to each joint drive motor; respective feedback control loop means for respectively controlling the power amplifier for each of the joint drive motors; servo control means for performing control support tasks and calculation tasks; control means including a first microprocessor having a relatively high computing performance capability and a relatively low data processing interface capability; control means further including a second microprocessor having a relatively high data processing performance capability; means for interfacing the first and second microprocessors; means for generating position commands for implementation by the second microprocessor; means for detecting motor position and velocity for each drive axis and for generating corresponding digital feedback signals; means for operating the second microprocessor to control the interfacing means so as to send position commands to the first microprocessor and receive calculated torque commands from the first microprocessor; and means for operating the second microprocessor to apply the torque commands to the torque control circuitry for execution and for synchronously receiving from the motor detecting means the digital feedback position and velocity signals.

  7. 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

  8. Towards real-time stereovision systems for planetary missions

    NASA Astrophysics Data System (ADS)

    Parkes, Stephen Maxwell

    1993-01-01

    Stereovision algorithms applicable to planetary mobile vehicles are considered. Stereovision systems have an important role to play in planetary exploration from digital elevation modeling of planetary surfaces to navigation of semiautonomous vehicles and control of robotic manipulators. Real time stereovision systems require very high processing power which can only be met by a heterogeneous multiprocessor processing architecture. The current and future processing technologies are examined together with the constraints on space-based electronic systems. The integrated multiprocessor system being developed for digital signal and image processing applications is described.

  9. 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

  10. 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

  11. Sex in Drosophila mauritiana: a very high level of amino acid polymorphism in a male reproductive protein gene, Acp26Aa.

    PubMed

    Tsaur, S C; Ting, C T; Wu, C I

    2001-01-01

    Many genes pertaining to male reproductive functions have been shown to evolve rapidly between species, and evidence increasingly suggest the influence of positive Darwinian selection. The accessory gland protein gene (Acp26Aa) of Drosophila is one such example. In order to understand the mechanism of selection, it is often helpful to examine the pattern of polymorphism. We report here that the level of amino acid polymorphism in the N-terminal quarter of Acp26Aa is high in Drosophila melanogaster and is unprecedented in its sibling species Drosophila mauritiana. We postulate that (1) this N-terminal segment may play a role in sperm competition, and (2) D. mauritiana may have been under much more intense sexual selection than other species. Both postulates have important ramifications and deserve to be tested rigorously.

  12. 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.

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

    DOE PAGES

    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.

  14. Thiolactomycin-based β-Ketoacyl-AcpM Synthase A (KasA) Inhibitors

    PubMed Central

    Kapilashrami, Kanishk; Bommineni, Gopal R.; Machutta, Carl A.; Kim, Pilho; Lai, Cheng-Tsung; Simmerling, Carlos; Picart, Francis; Tonge, Peter J.

    2013-01-01

    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

  15. Sequence-level comparative analysis of the Brassica napus genome around two stearoyl-ACP desaturase loci.

    PubMed

    Cho, Kwangsoo; O'Neill, Carmel M; Kwon, Soo-Jin; Yang, Tae-Jin; Smooker, Andrew M; Fraser, Fiona; Bancroft, Ian

    2010-02-01

    We conducted a sequence-level comparative analyses, at the scale of complete bacterial artificial chromosome (BAC) clones, between the genome of the most economically important Brassica species, Brassica napus (oilseed rape), and those of Brassica rapa, the genome of which is currently being sequenced, and Arabidopsis thaliana. We constructed a new B. napus BAC library and identified and sequenced clones that contain homoeologous regions of the genome including stearoyl-ACP desaturase-encoding genes. We sequenced the orthologous region of the genome of B. rapa and conducted comparative analyses between the Brassica sequences and those of the orthologous region of the genome of A. thaliana. The proportion of genes conserved (approximately 56%) is lower than has been reported previously between A. thaliana and Brassica (approximately 66%). The gene models for sets of conserved genes were used to determine the extent of nucleotide conservation of coding regions. This was found to be 84.2 +/- 3.9% and 85.8 +/- 3.7% between the B. napus A and C genomes, respectively, and that of A. thaliana, which is consistent with previous results for other Brassica species, and 97.5 +/- 3.1% between the B. napus A genome and B. rapa, and 93.1 +/- 4.9% between the B. napus C genome and B. rapa. The divergence of the B. napus genes from the A genome and the B. rapa genes was greater than anticipated and indicates that the A genome ancestor of the B. napus cultivar studied was relatively distantly related to the cultivar of B. rapa selected for genome sequencing.

  16. 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.

  17. 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.

  18. 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

  19. 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

  20. 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.

  1. 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.

  2. 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.

  3. Solution of sparse positive definite systems on a hypercube

    SciTech Connect

    George, A.; Heath, M.; Liu, J.; Ng, E.

    1988-10-01

    The solution of large sparse positive definite systems of equations typically involves four steps: ordering, data structure set-up (symbolic factorization), numerical factorization, and triangular solution. This article describes how these four phases are implemented on a hypercube multiprocessor. The role of elimination trees in the exploitation of sparsity and the identification of parallelism is explained, and pseudo-code algorithms are provided for some of the important algorithms. Numerical experiments run on an Intel iPSC multiprocessor are presented in order to provide some indication of the performance of the various algorithms. 36 refs., 23 figs., 5 tabs.

  4. 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

  5. Proceedings of the twentieth Hawaii international conference on system sciences

    SciTech Connect

    Shriver, B.D.

    1987-01-01

    This book presents the papers given at a conference which considered parallel processing. Topics covered at the conference included the implementation of LISP on Cray computers, executive codes, a programming language for the DADO parallel machine, parallel algorithms, multiprocessor algorithms, functional parallel languages, distributed processing systems, compiler technology, and issues in distributed data base systems.

  6. 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.

  7. 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

  8. 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.

  9. 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.

  10. Biochemical characteristics of AtFAR2, a fatty acid reductase from Arabidopsis thaliana that reduces fatty acyl-CoA and -ACP substrates into fatty alcohols.

    PubMed

    Doan, Thuy T P; Carlsson, Anders S; Stymne, Sten; Hofvander, Per

    2016-01-01

    Fatty alcohols and derivatives are important for proper deposition of a functional pollen wall. Mutations in specific genes encoding fatty acid reductases (FAR) responsible for fatty alcohol production cause abnormal development of pollen. A disrupted AtFAR2 (MS2) gene in Arabidopsis thaliana results in pollen developing an abnormal exine layer and a reduced fertility phenotype. AtFAR2 has been shown to be targeted to chloroplasts and in a purified form to be specific for acyl-ACP substrates. Here, we present data on the in vitro and in planta characterizations of AtFAR2 from A. thaliana and show that this enzyme has the ability to use both, C16:0-ACP and C16:0-CoA, as substrates to produce C16:0-alcohol. Our results further show that AtFAR2 is highly similar in properties and substrate specificity to AtFAR6 for which in vitro data has been published, and which is also a chloroplast localized enzyme. This suggests that although AtFAR2 is the major enzyme responsible for exine layer functionality, AtFAR6 might provide functional redundancy to AtFAR2. PMID:27274541

  11. 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.

  12. Recent advances in inhibitors of bacterial fatty acid synthesis type II (FASII) system enzymes as potential antibacterial agents.

    PubMed

    Wang, Yi; Ma, Shutao

    2013-10-01

    Bacterial infections are a constant and serious threat to human health. With the increase of multidrug resistance of clinically pathogenic bacteria, common antibiotic therapies have been less effective. Fatty acid synthesis type II (FASII) system enzymes are essential for bacterial membrane lipid biosynthesis and represent increasingly promising targets for the discovery of antibacterial agents with new mechanisms of action. This review highlights recent advances in inhibitors of bacterial FASII as potential antibacterial agents, paying special attention to the activities, mechanisms, and structure-activity relationships of those inhibitors that mainly target β-ketoacyl-ACP synthase, β-ketoacyl-ACP reductase, β-hydroxyacyl-ACP dehydratase, and enoyl-ACP reductase. Although inhibitors with low nanomolar and selective activity against various bacterial FASII have entered clinical trials, further research is needed to expand upon both available and yet unknown scaffolds to identify new FASII inhibitors that may have antibacterial potential, particularly against resistant bacterial strains.

  13. 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.

  14. 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.

  15. Framework for analysis of guaranteed QOS systems

    NASA Astrophysics Data System (ADS)

    Chaudhry, Shailender; Choudhary, Alok

    1997-01-01

    Multimedia data is isochronous in nature and entails managing and delivering high volumes of data. Multiprocessors with their large processing power, vast memory, and fast interconnects, are an ideal candidate for the implementation of multimedia applications. Initially, multiprocessors were designed to execute scientific programs and thus their architecture was optimized to provide low message latency and efficiently support regular communication patterns. Hence, they have a regular network topology and most use wormhole routing. The design offers the benefits of a simple router, small buffer size, and network latency that is almost independent of path length. Among the various multimedia applications, video on demand (VOD) server is well-suited for implementation using parallel multiprocessors. Logical models for VOD servers are presently mapped onto multiprocessors. Our paper provides a framework for calculating bounds on utilization of system resources with which QoS parameters for each isochronous stream can be guaranteed. Effects of the architecture of multiprocessors, and efficiency of various local models and mapping on particular architectures can be investigated within our framework. Our framework is based on rigorous proofs and provides tight bounds. The results obtained may be used as the basis for admission control tests. To illustrate the versatility of our framework, we provide bounds on utilization for various logical models applied to mesh connected architectures for a video on demand server. Our results show that worm hole routing can lead to packets waiting for transmission of other packets that apparently share no common resources. This situation is analogous to head-of-the-line blocking. We find that the provision of multiple VCs per link and multiple flit buffers improves utilization (even under guaranteed QoS parameters). This analogous to parallel iterative matching.

  16. Structural and Biological Evaluation of a Novel Series of Benzimidazole Inhibitors of Francisella tularensis Enoyl-ACP Reductase (FabI)

    PubMed Central

    Mehboob, Shahila; Song, Jinhua; Hevener, Kirk E; Su, Pin-Chih; Boci, Teuta; Brubaker, Libby; Truong, Lena; Mistry, Tina; Deng, Jiangping; Cook, James L; Santarsiero, Bernard D; Ghosh, Arun K; Johnson, Michael E

    2015-01-01

    Francisella tularensis, the causative agent of tularemia, presents a significant biological threat and is a Category A priority pathogen due to its potential for weaponization. The bacterial FASII pathway is a viable target for the development of novel antibacterial agents treating Gram-negative infections. Here we report the advancement of a promising series of benzimidazole FabI (enoyl-ACP reductase) inhibitors to a second-generation using a systematic, structure-guided lead optimization strategy, and the determination of several co-crystal structures that confirm the binding mode of designed inhibitors. These compounds display an improved low nanomolar enzymatic activity as well as promising low microgram/mL antibacterial activity against both F. tularensis and S. aureus and its methicillin-resistant strain (MRSA). The improvements in activity accompanying structural modifications lead to a better understanding of the relationship between the chemical structure and biological activity that encompasses both enzymatic and whole-cell activity. PMID:25677657

  17. 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.

  18. 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.

  19. 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

  20. A comparison of multiprocessor scheduling methods for iterative data flow architectures

    NASA Astrophysics Data System (ADS)

    Storch, Matthew

    1993-02-01

    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.

  1. 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.

  2. "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.

  3. 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.

  4. Data management system advanced architectures

    NASA Technical Reports Server (NTRS)

    Chevers, ED

    1991-01-01

    The topics relating to the Space Station Freedom (SSF) are presented in view graph form and include: (1) the data management system (DMS) concept; (2) DMS evolution rationale; (3) the DMS advance architecture task; (4) DMS group support for Ames payloads; (5) DMS testbed development; (6) the DMS architecture task status; (7) real time multiprocessor testbed; (8) networked processor performance; (9) and the DMS advance architecture task 1992 goals.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. The complement system of the duck.

    PubMed

    Koppenheffer, T L; Chan, S W; Higgins, D A

    1999-02-01

    Antibody (Ab)-dependent and-independent activation of the duck complement (C') system were studied. Ab-independent C' activity exhibited characteristics similar to those of the mammalian alternative C' pathway (ACP), including the selective lysis of rabbit erythrocytes (RRBC), a requirement for Mg2+, but not Ca2+, depletion of activity by zymosan, and lack of sensitivity to the mammalian C1 inhibitor carrageenan. Measurement of C' activity using antisera against sheep erythrocytes (SRBC) revealed that duck Abs activate C' by a pathway resembling the mammalian classical pathway (CCP) requiring both Ca2+ and Mg2+. Ab-dependent and-independent activities were further distinguishable by their kinetics of lysis and sensitivities to heat. Duck Abs were also found to activate C' in normal and carrageenan-treated serum by a mechanism that requires only Mg2+, and thus resembles the ACP. However, this Ab-dependent ACP-like activity exhibits patterns of ionic strength dependence and ontogeny which are clearly different from those of the conventional ACP and CCP. These findings indicate that duck C' can be activated by three mechanisms: Ab-mediated activation of the CCP, and Ab-mediated and Ab-independent activation of the ACP. Duck Ab responses to SRBC and RRBC were followed by direct agglutination, antiglobulin agglutination, and activation of the CCP and ACP. While the C'-activating abilities of duck anti-SRBC Abs persisted through a 3-month programme of inoculation, the anti-RRBC response lost its ability to activate C' after 2 weeks. PMID:16147546

  10. 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.

  11. Evaluating the Effect of CPP-ACP as a Final Irrigant in Improving the Micro-Hardness of Erosive Root Dentin and its Influence on the Bond Strength of Self Etch Resin Sealer – An In-vitro Study

    PubMed Central

    Bollineni, Swetha; Janga, Ravi Kumar; Saraswati, Disha; Babu, Mandava Ramesh

    2016-01-01

    Introduction Smear layer removal from the root canal wall involves the use of 17% EDTA and 5.25% sodium hypochlorite, which thereby improves the adhesion of obturating materials to root dentin. But these chemical irrigants have shown to decrease micro hardness, increase roughness, cause erosion and reduce the root dentin fracture toughness. To combat these adverse effects, studies can be focussed on the remineralisation of the erosive root dentin and this novel idea has been utilized in the present study. Aim To evaluate the micro hardness of erosive root dentin when Casein Phosphopeptide–Amorphous Calcium Phosphate (CPP-ACP) was used as a final irrigant and its influence on resin sealer bonding tested by push-out bond strength method. Materials and Methods Sixty extracted maxillary incisors were divided into three groups based on the final irrigation protocol. Group 1-normal saline, Group 2-17% EDTA (Ethylene Diamine Tetraacetic Acid) + 5.25% NaOCl (Sodium Hypochlorite), Group 3 - 17% EDTA + 5.25% NaOCl + CPP-ACP; each group was divided into two subgroups. Half the specimens of each group were evaluated for Vicker’s micro hardness test after the treatment. In continuation with the above methodology the remaining specimens were tested for push-out bond strength after obturation of the specimens with self etch adhesive resin sealer and conventional 6% gutta percha cones. Results Micro hardness was statistically analysed using Kruskal Wallis test and push-out bond strength was evaluated using Mann Whitney test and paired t-test. CPP-ACP treated group showed increased micro hardness (p<0.05). There was no statistically significant difference between the push-out bond strength values between group EDTA + NaOCl group and EDTA + NaOCl + CPP-ACP group. Conclusion Within the limitations of this study it can be concluded that, CPP-ACP improved the micro hardness of erosive root dentin and is not affecting its bond strength. Therefore, CPP-ACP may be used before bonding

  12. Modulation of medium-chain fatty acid synthesis in Synechococcus sp. PCC 7002 by replacing FabH with a Chaetoceros Ketoacyl-ACP synthase

    DOE PAGES

    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

  13. 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).

  14. 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

  15. 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

  16. Inhibitory effects on bacterial growth and beta-ketoacyl-ACP reductase by different species of maple leaf extracts and tannic acid.

    PubMed

    Wu, Dan; Wu, Xiao-Dong; You, Xue-Fu; Ma, Xiao-Feng; Tian, Wei-Xi

    2010-01-01

    It is important to develop new antibiotics aimed at novel targets. The investigation found that the leaf extracts from five maples (Acer platanoides, Acer campestre, Acer rubrum, Acer saccharum and Acer truncatum Bunge collected in Denmark, Canada and China) and their component tannic acid displayed antibacterial ability against 24 standard bacteria strains with the minimum inhibitory concentration of 0.3-8.0 mg/mL. Unlike the standard antibiotic levofloxacin (LFX), these samples inhibited Gram-positive bacteria more effectively than they inhibited Gram-negative bacteria. These samples effectively inhibited two antidrug bacterial strains. The results show that these samples inhibit bacteria by a different mechanism from LFX. These samples potently inhibited b-ketoacyl-ACP reductase (FabG), which is an important enzyme in bacterial fatty acid synthesis. Tannic acid showed the strongest inhibition on FabG with a half inhibition concentration of 0.78 microM (0.81 microg/mL). Furthermore, tannic acid and two maple leaf extracts showed time-dependent irreversible inhibition of FabG. These three samples also exhibited better inhibition on bacteria. It is suggested that FabG is the antibacteria target of maple leaf extracts and tannic acid, and both reversible and irreversible inhibitions of FabG are important for the antibacterial effect.

  17. 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

  18. 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.

  19. 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.

  20. 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.

  1. 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

  2. Homology modeling and docking studies of FabH (β-ketoacyl-ACP synthase III) enzyme involved in type II fatty acid biosynthesis of Chlorella variabilis: a potential algal feedstock for biofuel production.

    PubMed

    Misra, Namrata; Patra, Mahesh Chandra; Panda, Prasanna Kumar; Sukla, Lala Bihari; Mishra, Barada Kanta

    2013-03-01

    The concept of using microalgae as an alternative renewable source of biofuel has gained much importance in recent years. However, its commercial feasibility is still an area of concern for researchers. Unraveling the fatty acid metabolic pathway and understanding structural features of various key enzymes regulating the process will provide valuable insights to target microalgae for augmented oil content. FabH (β-ketoacyl-acyl carrier protein synthase; KAS III) is a condensing enzyme catalyzing the initial elongation step of type II fatty acid biosynthetic process and acyl carrier protein (ACP) facilitates the shuttling of the fatty acyl intermediates to the active site of the respective enzymes in the pathway. In the present study, a reliable three-dimensional structure of FabH from Chlorella variabilis, an oleaginous green microalga was modeled and subsequently the key residues involved in substrate binding were determined by employing protein-protein docking and molecular dynamics (MD) simulation protocols. The FabH-ACP complex having the lowest docking energy score showed the binding of ACP to the electropositive FabH surface with strong hydrogen bond interactions. The MD simulation results indicated that the substrate-complexed FabH adopted a more stable conformation than the free enzyme. Further, the FabH structure retained its stability throughout the simulation although noticeable displacements were observed in the loop regions. Molecular simulation studies suggested the importance of crucial hydrogen bonding of the conserved Arg(91) of FabH with Glu(53) and Asp(56) of ACP for exhibiting high affinity between the enzyme and substrate. The molecular modeling results are consistent with available experimental results on the flexibility of FabH and the present study provides first in silico insights into the structural and dynamical aspect of catalytic mechanism of FabH, which could be used for further site-specific mutagenic experiments to develop

  3. 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.

  4. 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

  5. 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

  6. 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.

  7. 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.

  8. Experience with the parallel solution of partial differential equations on a distributed computed system

    SciTech Connect

    Gelenbe, E.; Lichnewsky, A.; Staphylopatis, A.

    1982-12-01

    It is of interest to determine whether loosely coupled multiprocessors can be profitably used for the solution of larger numerical problems. The authors present a performance evaluation of the gain obtained by solving partial differential equation systems on such an architecture. The experimental setting is an LSI 11 based multiprocessor system using a fiber optics local area network designed and implemented at Laboratoire de Recherche en Informatique, Universite Paris-Sud. The paper includes a discussion of the numerical methods and of their implementation, a performance model of the parallel processing system, and measurements taken on the experimental system. The experimentally validated theoretical results confirm the interest of the authors approach based on performance models. 11 references.

  9. Using parallel banded linear system solvers in generalized eigenvalue problems

    NASA Technical Reports Server (NTRS)

    Zhang, Hong; Moss, William F.

    1994-01-01

    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 speedup 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.

  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. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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

  16. 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.

  17. 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.

  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. 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.

  20. 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.

  1. 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.

  2. 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.

  3. The PARTY parallel runtime system

    NASA Technical Reports Server (NTRS)

    Saltz, J. H.; Mirchandaney, Ravi; Smith, R. M.; Crowley, Kay; Nicol, D. M.

    1989-01-01

    In the present automated system for the organization of the data and computational operations entailed by parallel problems, in ways that optimize multiprocessor performance, general heuristics for partitioning program data and control are implemented by capturing and manipulating representations of a computation at run time. These heuristics are directed toward the dynamic identification and allocation of concurrent work in computations with irregular computational patterns. An optimized static-workload partitioning is computed for such repetitive-computation pattern problems as the iterative ones employed in scientific computation.

  4. Rabbit System. Low cost, high reliability front end electronics featuring 16 bit dynamic range. [Redundant Analog Bus Based Information Transfer

    SciTech Connect

    Drake, G.; Droege, T.F.; Nelson, C.A. Jr.; Turner, K.J.; Ohska, T.K.

    1985-10-01

    A new crate-based front end system has been built which features low cost, compact packaging, command capability, 16 bit dynamic range digitization, and a high degree of redundancy. The crate can contain a variety of instrumentation modules, and is designed to be situated close to the detector. The system is suitable for readout of a large number of channels via parallel multiprocessor data acquisition.

  5. 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

  6. 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.

  7. Health monitoring system for the SSME - Hardware architecture study

    NASA Technical Reports Server (NTRS)

    Kamenetz, Jeffry K.; Hawman, Mike W.; Tulpule, Sharayu

    1990-01-01

    This paper presents a hardware architecture for a health monitoring system (HMS) for the SSME. The architecture study was conducted in conjunction with a NASA sponsored program to develop a framework for SSME HMS for (1) ground test and, potentially (2) flight applications. The requirements for both systems are both stated and analyzed. A multiprocessor distributed VME system is envisioned for the ground-test hardware. By repackaging the boards, the same concept is shown to be usable for the flight system. The paper concludes with an analysis of weight, power, and reliability with respect to variations in functionality.

  8. 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.

  9. 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.

  10. Effect of acetate formation pathway and long chain fatty acid CoA-ligase on the free fatty acid production in E. coli expressing acy-ACP thioesterase from Ricinus communis.

    PubMed

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

    2012-07-01

    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. Wild type E. coli strains produce fatty acids mainly for the biosynthesis of lipids and cell membranes and do not accumulate free fatty acids as intermediates in lipid biosynthesis. However, free fatty acids can be produced by breaking the fatty acid elongation through the overexpression of an acyl-ACP thioesterase. Since acetyl-CoA might be an important factor for fatty acid synthesis (acetate formation pathways are the main competitive pathways in consuming acetyl-CoA or pyruvate, a precursor of acetyl-CoA), and the long chain fatty acid CoA-ligase (FadD) plays a pivotal role in the transport and activation of exogenous fatty acids prior to their subsequent degradation, we examined the composition and the secretion of the free fatty acids in four different strains including the wild type MG1655, a mutant strain with inactivation of the fatty acid beta-oxidation pathway (fadD mutant (ML103)), and mutant strains with inactivation of the two major acetate production pathways (an ack-pta (acetate kinase/phosphotransacetylase), poxB (pyruvate oxidase) double mutant (ML112)) and a fadD, ack-pta, poxB triple mutant (ML115). The engineered E. coli cells expressing acyl-ACP thioesterase with glucose yield is higher than 40% of theoretical yield. Compared to MG1655(pXZ18) and ML103(pXZ18), acetate forming pathway deletion strains such as ML112(pXZ18) and ML115(pXZ18) produced similar quantity of total free fatty acids, which indicated that acetyl-CoA availability does not appear to be limiting factor for fatty acid production in these strains. However, these strains did show significant differences in the composition of free fatty acids. Different from MG1655(pXZ18) and ML103(pXZ18), acetate formation pathway deletion strains such as ML112(pXZ18) and ML115

  11. Mass Spectrometry-Based Systems Approach for Identification of Inhibitors of Plasmodium falciparum Fatty Acid Synthase▿

    PubMed Central

    Sharma, Shilpi; Sharma, Shailendra Kumar; Modak, Rahul; Karmodiya, Krishanpal; Surolia, Namita; Surolia, Avadhesha

    2007-01-01

    The emergence of strains of Plasmodium falciparum resistant to the commonly used antimalarials warrants the development of new antimalarial agents. The discovery of type II fatty acid synthase (FAS) in Plasmodium distinct from the FAS in its human host (type I FAS) opened up new avenues for the development of novel antimalarials. The process of fatty acid synthesis takes place by iterative elongation of butyryl-acyl carrier protein (butyryl-ACP) by two carbon units, with the successive action of four enzymes constituting the elongation module of FAS until the desired acyl length is obtained. The study of the fatty acid synthesis machinery of the parasite inside the red blood cell culture has always been a challenging task. Here, we report the in vitro reconstitution of the elongation module of the FAS of malaria parasite involving all four enzymes, FabB/F (β-ketoacyl-ACP synthase), FabG (β-ketoacyl-ACP reductase), FabZ (β-ketoacyl-ACP dehydratase), and FabI (enoyl-ACP reductase), and its analysis by matrix-assisted laser desorption-time of flight mass spectrometry (MALDI-TOF MS). That this in vitro systems approach completely mimics the in vivo machinery is confirmed by the distribution of acyl products. Using known inhibitors of the enzymes of the elongation module, cerulenin, triclosan, NAS-21/91, and (−)-catechin gallate, we demonstrate that accumulation of intermediates resulting from the inhibition of any of the enzymes can be unambiguously followed by MALDI-TOF MS. Thus, this work not only offers a powerful tool for easier and faster throughput screening of inhibitors but also allows for the study of the biochemical properties of the FAS pathway of the malaria parasite. PMID:17485508

  12. Design and construction of the high-speed optoelectronic memory system demonstrator.

    PubMed

    Barbieri, Roberto; Benabes, Philippe; Bierhoff, Thomas; Caswell, Josh J; Gauthier, Alain; Jahns, Jürgen; Jarczynski, Manfred; Lukowicz, Paul; Oksman, Jacques; Russell, Gordon A; Schrage, Jürgen; Snowdon, John F; Stübbe, Oliver; Troster, Gerhard; Wirz, Marco

    2008-07-01

    The high-speed optoelectronic memory system project is concerned with the reduction of latency within multiprocessor computer systems (a key problem) by the use of optoelectronics and associated packaging technologies. System demonstrators have been constructed to enable the evaluation of the technologies in terms of manufacturability. The system combines fiber, free space, and planar integrated optical waveguide technologies to augment the electronic memory and the processor components. Modeling and simulation techniques were developed toward the analysis and design of board-integrated waveguide transmission characteristics and optical interfacing. We describe the fabrication, assembly, and simulation of the major components within the system.

  13. 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.

  14. 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.

  15. 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.

  16. 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

  17. 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).

  18. Communications processor speeds Unix-based multi-user system

    SciTech Connect

    Pickard, M.

    1983-03-01

    Handling the many interrupts and disk accesses involved in a multiuser, multitasking environment presents a problem for Unix-based systems. The Plexus computers Inc.'s P/40 takes a multiprocessor approach, distributing tasks such as controlling high- and low-speed to outboard processors. By giving these processors their own memory and a direct-memory-access channel, they can handle most interrupts. The key component to this approach is the intelligent peripheral processor, which, along with intelligent peripheral controllers and a memory-control unit, frees the main processor to manage heavy computing loads.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. Gigaflop speed algorithm for the direct solution of large block-tridiagonal systems in 3-D physics applications

    SciTech Connect

    Anderson, D.V.; Fry, A.R.; Gruber, R.; Roy, A.

    1989-03-01

    In the discretization of the 3-D partial differential equations of many physics problems, it is found that the resultant system of linear equations can be represented by a block tridiagonal matrix. Depending on the substructure of the blocks, one can devise many algorithms for the solution of these systems. For plasma physics problems of interest to the authors, several interesting matrix problems arise that should be useful in other applications as well. In one case, where the blocks are dense, it was found that by using a multitasked cyclic reduction procedure, it was possible to reach gigaflop rates on a Cray-2 for the direct solve of these large linear systems. The recently built code PAMS (parallelized matrix solver) embodies this technique and uses fast vendor-supplied routines and obtains this good performance. Manipulations within the blocks are done by these highly optimized linear algebra subroutines that exploit vectorization as well as overlap of the functional units within each CPU. In unitasking mode, speeds well above 340 Mflops have been measured. The cyclic reduction method multitasks quite well with overlap factors in the range of three to four. In multitasking mode, average speeds of 1.1 gigaflops have been measured for the entire PAMS algorithm. In addition to the presentation of the PAMS algorithm, it is shown how related systems having banded blocks may be treated efficiently by multitasked cyclic reduction in the Cray-2 multiprocessor environment. The PAMS method is intended for multiprocessors and would not be a method of choice on a uniprocessor. Furthermore, this method's advantage was found to be critically dependent on the hardware, software, and charging algorithm installed on any given multiprocessor system.

  6. A new partitioning strategy for efficient re-analysis of large structural systems

    NASA Technical Reports Server (NTRS)

    Noor, Ahmed K.; Peters, Jeanne M.

    1989-01-01

    A computational procedure is presented for the reanalysis of large unsymmetric structural systems. The procedure is based on a novel partitioning strategy in which the responses of both the original and modified structures are approximated by symmetric and antisymmetric response vectors, each obtained by using only a fraction of the degrees of freedom of the discrete model of the structure. The procedure is applied to linear static analysis of framed structures. Design modifications consisted of removing members, resulting in topologically unsymmetric structures. The efficient application of the procedure on sequential computers as well as on multiprocessor computers is discussed, and its effectiveness is demonstrated by means of two numerical examples.

  7. 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.

  8. 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.

  9. 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

  10. Production of glucose-6-phosphate by glucokinase coupled with an ATP regeneration system.

    PubMed

    Yan, Bingkun; Ding, Qingbao; Ou, Ling; Zou, Zhi

    2014-03-01

    A process of glucose-6-phosphate (G-6-P) production coupled with an adenosine triphosphate (ATP) regeneration system was constructed that utilized acetyl phosphate (ACP) via acetate kinase (ACKase). The genes glk and ack from Escherichia coli K12 were amplified and cloned into pET-28a(+), then transformed into E. coli BL21 (DE3) and the recombinant strains were named pGLK and pACK respectively. Glucokinase (glkase) in pGLK and ACKase in pACK were both overexpressed in soluble form. G-6-P was efficiently produced from glucose and ACP using a very small amount of ATP. The conversion yield was greater than 97 % when the reaction solution containing 10 mM glucose, 20 mM ACP-Na₂, 0.5 mM ATP, 5 mM Mg²⁺, 50 mM potassium phosphate buffer (pH 7.0), 4.856 U glkase and 3.632 U ACKase were put into 37 °C water bath for 1 h. PMID:24165747

  11. 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.

  12. 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.

  13. 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.

  14. Predicting multiprocessing efficiency on the Cray multiprocessors in a (CTSS) time-sharing environment/application to a 3-D magnetohydrodynamics code

    SciTech Connect

    Mirin, A.A.

    1988-07-01

    A formula is derived for predicting multiprocessing efficiency on Cray supercomputers equipped with the Cray Time-Sharing System (CTSS). The model is applicable to an intensive time-sharing environment. The actual efficiency estimate depends on three factors: the code size, task length, and job mix. The implementation of multitasking in a three-dimensional plasma magnetohydrodynamics (MHD) code, TEMCO, is discussed. TEMCO solves the primitive one-fluid compressible MHD equations and includes resistive and Hall effects in Ohm's law. Virtually all segments of the main time-integration loop are multitasked. The multiprocessing efficiency model is applied to TEMCO. Excellent agreement is obtained between the actual multiprocessing efficiency and the theoretical prediction.

  15. 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.

  16. 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.

  17. Closed-form solutions of performability. [in computer systems

    NASA Technical Reports Server (NTRS)

    Meyer, J. F.

    1982-01-01

    It is noted that if computing system performance is degradable then system evaluation must deal simultaneously with aspects of both performance and reliability. One approach is the evaluation of a system's performability which, relative to a specified performance variable Y, generally requires solution of the probability distribution function of Y. The feasibility of closed-form solutions of performability when Y is continuous are examined. 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. Employing an approximate decomposition of the model, it is shown that a closed-form solution can indeed be obtained.

  18. Performance of a modular interactive data analysis system (MIDAS)

    SciTech Connect

    Maples, C.; Weaver, D.; Logan, D.; Rathbun, W.

    1983-01-01

    A processor cluster, part of a multiprocessor system named MIDAS (modular interactive data analysis system), has been constructed and tested. The architecture permits considerable flexibility in organizing the processing elements for different applications. The current tests involved 8 general CPUs from commercial computers, 2 special purpose pipelined processors and a specially designed communications system. Results on a variety of programs indicated that the cluster performs from 8 to 16 times faster than a standard computer with an identical CPU. The range represents the effect of differing CPU and I/O requirements-ranging from CPU intensive to I/O intensive. A benchmark test indicated that the cluster performed at approximately 85percent the speed of the CDC 7600. Plans for further cluster enhancements and multicluster operation are discussed. 5 references.

  19. 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

  20. VME and network applications for the JT-60U control system

    NASA Astrophysics Data System (ADS)

    Kimura, T.

    1994-12-01

    The control system for the large tokamak JT-60 at JAERI-Naka was completed in 1985. It was originally composed of 16-bit industrial minicomputers and CAMAC systems with 16-bit microcomputers. Rejuvenation of the control system has become necessary to improving the control performance. The renewal of the control system is also stimulated by the requirements for upgrading the software development and hardware maintenance environment of the control system. This paper describes how the control system was and will be upgraded, utilizing the advanced technologies of VME and networks. Two years ago, a VMEbus-based 32-bit multiprocessor system for fast plasma control and a new operator's console using UNIX workstations connected to an Ethernet LAN were developed to cope with upgrading the JT-60 tokamak (JT-60U). VME and network applications are now being extended to the level of subsystem controllers.

  1. 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.

  2. 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.

  3. Low Latency Messages on Distributed Memory Multiprocessors

    DOE PAGES

    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

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  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. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. 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.

  19. 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.

  20. 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.

  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. 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.

  4. 26 CFR 1.401(m)-2 - ACP test.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... be distributed under the plan. Second, the plan must apportion the total amount of excess aggregate... 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)....

  5. 26 CFR 1.401(m)-2 - ACP test.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... an eligible employee's qualified military service under section 414(u) are not taken into account.... For plan years beginning on or after January 1, 2008, the income allocable to excess aggregate...)(D) of this section for rules that apply to plan years beginning before January 1, 2008. (B)...

  6. 26 CFR 1.401(m)-2 - ACP test.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... employee contributions under Plan S and Plan T, two calendar-year profit-sharing plans of Employer H. Plan... 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)....

  7. 26 CFR 1.401(m)-2 - ACP test.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... employee contributions under Plan S and Plan T, two calendar-year profit-sharing plans of Employer H. Plan... 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)....

  8. 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 ...

  9. 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.

  10. 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.

  11. 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.

  12. Optical interconnection networks for high-performance computing systems.

    PubMed

    Biberman, Aleksandr; Bergman, Keren

    2012-04-01

    Enabled by silicon photonic technology, optical interconnection networks have the potential to be a key disruptive technology in computing and communication industries. The enduring pursuit of performance gains in computing, combined with stringent power constraints, has fostered the ever-growing computational parallelism associated with chip multiprocessors, memory systems, high-performance computing systems and data centers. Sustaining these parallelism growths introduces unique challenges for on- and off-chip communications, shifting the focus toward novel and fundamentally different communication approaches. Chip-scale photonic interconnection networks, enabled by high-performance silicon photonic devices, offer unprecedented bandwidth scalability with reduced power consumption. We demonstrate that the silicon photonic platforms have already produced all the high-performance photonic devices required to realize these types of networks. Through extensive empirical characterization in much of our work, we demonstrate such feasibility of waveguides, modulators, switches and photodetectors. We also demonstrate systems that simultaneously combine many functionalities to achieve more complex building blocks. We propose novel silicon photonic devices, subsystems, network topologies and architectures to enable unprecedented performance of these photonic interconnection networks. Furthermore, the advantages of photonic interconnection networks extend far beyond the chip, offering advanced communication environments for memory systems, high-performance computing systems, and data centers.

  13. Economical graphics display system for flight simulation avionics

    NASA Technical Reports Server (NTRS)

    1990-01-01

    During the past academic year the focal point of this project has been to enhance the economical flight simulator system by incorporating it into the aero engineering educational environment. To accomplish this goal it was necessary to develop appropriate software modules that provide a foundation for student interaction with the system. In addition experiments had to be developed and tested to determine if they were appropriate for incorporation into the beginning flight simulation course, AERO-41B. For the most part these goals were accomplished. Experiments were developed and evaluated by graduate students. More work needs to be done in this area. The complexity and length of the experiments must be refined to match the programming experience of the target students. It was determined that few undergraduate students are ready to absorb the full extent and complexity of a real-time flight simulation. For this reason the experiments developed are designed to introduce basic computer architectures suitable for simulation, the programming environment and languages, the concept of math modules, evaluation of acquired data, and an introduction to the meaning of real-time. An overview is included of the system environment as it pertains to the students, an example of a flight simulation experiment performed by the students, and a summary of the executive programming modules created by the students to achieve a user-friendly multi-processor system suitable to an aero engineering educational program.

  14. Software architecture for a distributed real-time system in Ada, with application to telerobotics

    NASA Technical Reports Server (NTRS)

    Olsen, Douglas R.; Messiora, Steve; Leake, Stephen

    1992-01-01

    The architecture structure and software design methodology presented is described in the context of telerobotic application in Ada, specifically the Engineering Test Bed (ETB), which was developed to support the Flight Telerobotic Servicer (FTS) Program at GSFC. However, the nature of the architecture is such that it has applications to any multiprocessor distributed real-time system. The ETB architecture, which is a derivation of the NASA/NBS Standard Reference Model (NASREM), defines a hierarchy for representing a telerobot system. Within this hierarchy, a module is a logical entity consisting of the software associated with a set of related hardware components in the robot system. A module is comprised of submodules, which are cyclically executing processes that each perform a specific set of functions. The submodules in a module can run on separate processors. The submodules in the system communicate via command/status (C/S) interface channels, which are used to send commands down and relay status back up the system hierarchy. Submodules also communicate via setpoint data links, which are used to transfer control data from one submodule to another. A submodule invokes submodule algorithms (SMA's) to perform algorithmic operations. Data that describe or models a physical component of the system are stored as objects in the World Model (WM). The WM is a system-wide distributed database that is accessible to submodules in all modules of the system for creating, reading, and writing objects.

  15. Documentation generator for VHDL and MatLab source codes for photonic and electronic systems

    NASA Astrophysics Data System (ADS)

    Niton, B.; Pozniak, K. T.; Romaniuk, R. S.

    2011-06-01

    The UML, which is a complex system modeling and description technology, has recently been expanding its uses in the field of formalization and algorithmic approach to such systems like multiprocessor photonic, optoelectronic and advanced electronics carriers; distributed, multichannel measurement systems; optical networks, industrial electronics, novel R&D solutions. The paper describes a new concept of software dedicated for documenting the source codes written in VHDL and MatLab. The work starts with the analysis of available documentation generators for both programming languages, with an emphasis on the open source solutions. There are presented own solutions which base on the Doxygen program available as a free license with the source code. The supporting tools for parsers building were used like Bison and Flex. The documentation generator application is used for design of large optoelectronic and electronic measurement and control systems. The paper consists of three parts which describe the following components of the documentation generator for photonic and electronic systems: concept, MatLab application and VHDL application. This is part one which describes the system concept. Part two describes the MatLab application. MatLab is used for description of the measured phenomena. Part three describes the VHDL application. VHDL is used for behavioral description of the optoelectronic system. All the proposed approach and application documents big, complex software configurations for large systems.

  16. 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.

  17. Evolution of the ATLAS Nightly Build System

    NASA Astrophysics Data System (ADS)

    Undrus, A.

    2012-12-01

    The ATLAS Nightly Build System is a major component in the ATLAS collaborative software organization, validation, and code approval scheme. For over 10 years of development it has evolved into a factory for automatic release production and grid distribution. The 50 multi-platform branches of ATLAS releases provide vast opportunities for testing new packages, verification of patches to existing software, and migration to new platforms and compilers for ATLAS code that currently contains 2200 packages with 4 million C++ and 1.4 million python scripting lines written by about 1000 developers. Recent development was focused on the integration of ATLAS Nightly Build and Installation systems. The nightly releases are distributed and validated and some are transformed into stable releases used for data processing worldwide. The ATLAS Nightly System is managed by the NICOS control tool on a computing farm with 50 powerful multiprocessor nodes. NICOS provides the fully automated framework for the release builds, testing, and creation of distribution kits. The ATN testing framework of the Nightly System runs unit and integration tests in parallel suites, fully utilizing the resources of multi-core machines, and provides the first results even before compilations complete. The NICOS error detection system is based on several techniques and classifies the compilation and test errors according to their severity. It is periodically tuned to place greater emphasis on certain software defects by highlighting the problems on NICOS web pages and sending automatic e-mail notifications to responsible developers. These and other recent developments will be presented and future plans will be described.

  18. Design consideration in constructing high performance embedded Knowledge-Based Systems (KBS)

    NASA Technical Reports Server (NTRS)

    Dalton, Shelly D.; Daley, Philip C.

    1988-01-01

    As the hardware trends for artificial intelligence (AI) involve more and more complexity, the process of optimizing the computer system design for a particular problem will also increase in complexity. Space applications of knowledge based systems (KBS) will often require an ability to perform both numerically intensive vector computations and real time symbolic computations. Although parallel machines can theoretically achieve the speeds necessary for most of these problems, if the application itself is not highly parallel, the machine's power cannot be utilized. A scheme is presented which will provide the computer systems engineer with a tool for analyzing machines with various configurations of array, symbolic, scaler, and multiprocessors. High speed networks and interconnections make customized, distributed, intelligent systems feasible for the application of AI in space. The method presented can be used to optimize such AI system configurations and to make comparisons between existing computer systems. It is an open question whether or not, for a given mission requirement, a suitable computer system design can be constructed for any amount of money.

  19. Use of neural networks to recover from software faults in real-time systems

    NASA Astrophysics Data System (ADS)

    Hunter, Erwin L.; Pandya, Abhijit S.; Coulter, Neal

    1994-03-01

    In fault-tolerant real-time systems, software errors can be detected, recovered from, and reported using a recovery controller. A simulator has been developed to test the performance of an ANN (Artificial Neural Network) based recovery controller. The simulator for a highly reliable, fault-tolerant multiprocessor telecommunications exchange provides a real-world application to test the effectiveness of the ANN recovery controller. The ANN provides the software recovery controller with the adaptability to determine recovery actions for faults that were previously unseen or not anticipated. This reduces the number of times that human intervention is required to recover the system, and thus reduces the total down-time for the system. The ANN is trained by inserting known faults into the simulated real-time system. The system collects data on the characteristics observed when the fault is detected and uses the back propagation learning algorithm to classify the observed characteristics and recent history of recovery actions into an appropriate recovery action such as restarting or terminating a process, initializing the operating system for a specific processor, or reloading a data base for a processor of group of processors. Once the neural network has been trained, it is used to determine the appropriate responses for faults that occur during the operation of the system.

  20. Terminal Area Simulation System User's Guide - Version 10.0

    NASA Technical Reports Server (NTRS)

    Switzer, George F.; Proctor, Fred H.

    2014-01-01

    The Terminal Area Simulation System (TASS) is a three-dimensional, time-dependent, large eddy simulation model that has been developed for studies of wake vortex and weather hazards to aviation, along with other atmospheric turbulence, and cloud-scale weather phenomenology. This document describes the source code for TASS version 10.0 and provides users with needed documentation to run the model. The source code is programed in Fortran language and is formulated to take advantage of vector and efficient multi-processor scaling for execution on massively-parallel supercomputer clusters. The code contains different initialization modules allowing the study of aircraft wake vortex interaction with the atmosphere and ground, atmospheric turbulence, atmospheric boundary layers, precipitating convective clouds, hail storms, gust fronts, microburst windshear, supercell and mesoscale convective systems, tornadic storms, and ring vortices. The model is able to operate in either two- or three-dimensions with equations numerically formulated on a Cartesian grid. The primary output from the TASS is time-dependent domain fields generated by the prognostic equations and diagnosed variables. This document will enable a user to understand the general logic of TASS, and will show how to configure and initialize the model domain. Also described are the formats of the input and output files, as well as the parameters that control the input and output.