To provide high-level graphical support for PVM (Parallel Virtual Machine) based program development, a complex programming environment (GRADE) is being developed. GRADE currently provides tools to construct, execute, debug, monitor and visualise message-passing parallel programs. It offers high-level graphical programming abstraction mechanism to construct parallel applications by introducing a new graphical language called GRAPNEL. GRADE also provides the programmer with the same graphical user interface during the program design and debugging stages. A distributed debugging engine (DDBG) assists the user in debugging GRAPNEL programs on distributed memory computer architectures. Tape/PVM and PROVE support the performance monitoring and visualization of parallel programs developed in the GRADE environment.

To achieve a certain degree of confidence that a given program follows its specification, a testing phase must be included in the program development process, and also a complementary debugging phase to help locating the program's bugs. This paper presents an environment which results of the composition and integration of two basic tools: STEPS (Structural TEsting of Parallel Software), which is a testing tool, and DDBG (Distributed DeBuGger), which is a debugging tool. The two tools are presented individually as stand-alone tools, and we describe how they were combined through the use of another intermediate tool: DEIPA (Deterministic re-Execution and Interactive Program Analysis). We claim that the result achieved is a very effective testing and debugging environment.

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To achieve a certain degree of confidence that a given program follows its specification, a testing phase must be included in the program development process, and also a complementary debugging phase to help locating the program’s bugs. This paper presents an environment which results of the composition and integration of two basic tools: STEPS (Structural TEsting of Parallel Software), which is a testing tool, and DDBG (Distributed DeBuGger), which is a debugging tool. The two tools are presented individually as stand-alone tools, and we describe how they were combined through the use of another intermediate tool: DEIPA (Deterministic re-Execution and Interactive Program Analysis). We claim that the result achieved is a very effective testing and debugging environment.

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Conversion of Fe ions in solution to the solid phase in ferritin concentrates iron required for cell function. The rate of the Fe phase transition in ferritin is tissue specific and reflects the differential expression of two classes of ferritin subunits (H and L). Early stages of mineralization were probed by rapid freeze-quench Mossbauer, at strong fields (up to 8 T), and EPR spectroscopy in an H-type subunit, recombinant frog ferritin; small numbers of Fe (36 moles/mol of protein) were used to increase Fe3+ in mineral precursor forms, At 25 ms, four Fe3+-oxy species (three Fe dimers and one Fe trimer) were identified, These Fe3+-oxy species were found to form at similar rates and decay subsequently to a distinctive superparamagentic species designated the ''young core.'' The rate of oxidation of Fe2+ (1026 s(-1)) corresponded well to the formation constant for the Fe3+- tyrosinate complex (920 s(-1)) observed previously [Waldo, G. S., & Theil, E. C. (1993) Biochemistry 32, 13261] and, coupled with EPR data, indicates that several or possibly all of the Fe3+-oxy species involve tyrosine. The results, combined with previous Mossbauer studies of Y30F human H-type ferritin which showed decreases in several Fe3+ intermediates and stabilization of Fe2+ [Bauminger, E. R., et al. (1993) Biochem, J. 296, 709], emphasize the involvement of tyrosyl residues in the mineralization of H-type ferritins. The subsequent decay of these multiple Fe3+-oxy species to the superparamagnetic mineral suggests that Fe3+ species in different environments may be translocated as intact units from the protein shell into the ferritin cavity where the conversion to a solid mineral occurs.

We discuss issues in the design and implementation of a flexible debugging tool and its integration into a parallel software engineering environment.

{Dodecaheme cytochrome c has been purified from Desulfovibrio (D.) desulfuricans ATCC 27774 cells grown under both nitrate and sulfate-respiring conditions. Therefore, it is likely to play a role in the electron-transfer system of both respiratory chains. Its molecular mass (37 768 kDa) was determined by electrospray mass spectrometry. Its first 39 amino acids were sequenced and a motif was found between amino acids 32 and 37 that seems to exist in all the cytochromes of the c3 type from sulfate-reducing bacteria sequenced at present. The midpoint redox potentials of this cytochrome were estimated to be -68, -120, -248 and -310 mV. Electron paramagnetic resonance spectroscopy of the oxidized cytochrome shows several low-spin components with a g(max) spreading from 3.254 to 2.983. Two crystalline forms were obtained by vapour diffusion from a solution containing 2% PEG 6000 and 0.25-0.75 M acetate buffer pH = 5.5. Both crystals belong to monoclinic space groups: one is PZ,, with a = 61.00

The primary structure of desulfoferrodoxin from Desulfovibrio desulfuricans ATCC 27774, a redox protein with two mononuclear iron sites, was determined by automatic Edman degradation and mass spectrometry of the composing peptides, It contains 125 amino acid residues of which five are cysteines, The first four, Cys-9, Cys-12, Cys-28 and Cys-29, are responsible for the binding of Center I which has a distorted tetrahedral sulfur coordination similar to that found in desulforedoxin from D. gigas, The remaining Cys-115 is proposed to be involved in the coordination of Center II, which is probably octahedrally coordinated with predominantly nitrogen/oxygen containing ligands as previously suggested by Mossbauer and Raman spectroscopy.

{Crystals of the fully oxidized form of desulfoferrodoxin were obtained by vapor diffusion from a solution containing 20% PEG 4000, 0.1 M HEPES buffer, pH 7.5, and 0.2 M CaCl2. Trigonal and/or rectangular prisms could be obtained, depending on the temperature used for the crystal growth. Trigonal prisms belong to the rhombohedral space group R32, with a = 112.5 A and c = 63.2 A; rectangular prisms belong to the monoclinic space group C2, with a = 77.7 A

This communication reports the isolation, purification and characterization of key enzymes involved in dissimilatory sulfate reduction of a sulfate reducing bacterium classified as Desulfovibrio desulfuricans subspecies desulfuricans New Jersey (NCIMB 8313) (Ddd NJ). The chosen strain, originally recovered from a corroding cast iron heat exchanger, was grown in large scale batch cultures. Physico-chemical and spectroscopic studies of the purified enzymes were carried out. These analyses revealed a high degree of similarity between proteins isolated from the DddNJ strain and the homologous proteins obtained from Desulfomicrobium baculatus Norway 4. In view of the results obtained, taxonomic reclassification of Desulfovibrio desulfuricans subspecies desulfuricans New Jersey (NCIMB 8313) into Desulfomicrobium baculatus (New Jersey) is proposed. (C) 1996 Academic Press, Inc.

This paper describes a debugging interface that has been developed for a parallel software engineering environment and that was developed on top of the PVM environment in the scope of the SEPP and HPCTI projects of the COPERNICUS Program. The main goal of this interface is to provide the basic debugging functionalities that are required by some components of that environment. We give special attention to the requirements posed by high-level tools of the environment, and to the need of providing a flexible debugging support layer that can be suitably adapted and extended. We present the system logical architecture and the interface specification of the debugging engine. We discuss its interfacing with other components of the environment, namely a graphical editor for the GRAPNEL visual parallel programming language, and a testing tool. We finally describe current work on the improvement of the debugging engine. Keywords: Debugging, monitoring, parallel processing, software tools.

This paper presents an approach to education in Parallel and Distributed Processing undertaken in the Technical University of Gdansk and Technical University of Wroclaw. The paper gives a detailed structure of the project entitled "Teaching Parallel Processing: Development of Curriculum and Software Tools" which was started in 1994 and will be finish in 1997. Two universities from Poland: Technical University of Gdansk and Technical University of Wroclaw and two universities from EC countries: University Autònoma of Barcelona from Spain and University Nova of Lisbon from Portugal participate in the presented project. The main aim of the project is to develop existing curricula of Computer Science specialisation and to establish specialisation concerned with parallel and distributed processing at Polish universities.

This communication reports the isolation, purification and characterization of key enzymes involved in dissimilatory sulfate reduction of a sulfate reducing bacterium classified as Desulfovibrio desulfuricans subspecies desulfuricans New Jersey (NCIMB 8313) (Ddd NJ). The chosen strain, originally recovered from a corroding cast iron heat exchanger, was grown in large scale batch cultures. Physico-chemical and spectroscopic studies of the purified enzymes were carried out. These analyses revealed a high degree of similarity between proteins isolated from the DddNJ strain and the homologous proteins obtained from Desulfomicrobium baculatus Norway 4. In view of the results obtained, taxonomic reclassification of Desulfovibrio desulfuricans subspecies desulfuricans New Jersey (NCIMB 8313) into Desulfomicrobium baculatus (New Jersey) is proposed. (C) 1996 Academic Press, Inc.

This paper describes a debugging interface that has been developed for a parallel software engineering environment and that was developed on top of the PVM environment in the scope of the SEPP and HPCTI projects of the COPERNICUS Program. The main goal of this interface is to provide the basic debugging functionalities that are required by some components of that environment. We give special attention to the requirements posed by high-level tools of the environment, and to the need of providing a flexible debugging support layer that can be suitably adapted and extended. We present the system logical architecture and the interface specification of the debugging engine. We discuss its interfacing with other components of the environment, namely a graphical editor for the GRAPNEL visual parallel programming language, and a testing tool. We finally describe current work on the improvement of the debugging engine. Keywords: Debugging, monitoring, parallel processing, software tools.

We discuss issues in the design and implementation of a flexible debugging tool and its integration into a parallel software engineering environment.

In this paper we present a study on the electrical characteristics (conductivity, σ and relative dielectric constant, εr) of amorphous silicon nitride (a-SixN1-x) and carbide (a-SixC1-x) films deposited by PECVD, used as dielectric materials in TFT devices, aiming to select the most adequate alloy that lead to improve device performances. Besides that, double stack a-SixN1-x/a-SixC1-x structures were developed and applied as dielectric layers on TFTs, whose performances show to be superior to those ones using single silicon nitride or silicon carbide as dielectric.

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The primary structure of desulfoferrodoxin from Desulfovibrio desulfuricans ATCC 27774, a redox protein with two mononuclear iron sites, was determined by automatic Edman degradation and mass spectrometry of the composing peptides. It contains 125 amino acid residues of which five are cysteines. The first four, Cys-9, Cys-12, Cys-28 and Cys-29, are responsible for the binding of Center I which has a distorted tetrahedral sulfur coordination similar to that found in desulforedoxin from D. gigas. The remaining Cys-115 is proposed to be involved in the coordination of Center II, which is probably octahedrally coordinated with predominantly nitrogen/oxygen containing ligands as previously suggested by Mossbauer and Raman spectroscopy.