From StPowla processes to SRML models

Service Oriented Computing is a paradigm for developing software systems as the composition of a number of services. Services are loosely coupled entities, that can be dynamically published, discovered and invoked over a network. The engineering of such systems presents novel challenges, mostly due to the dynamicity and distributed nature of service-based applications. In this paper, we focus on the modelling of service orchestrations. We discuss the relationship between two languages developed under the Sensoria project: SRML as a high level modelling language for Service Oriented Architectures, and StPowla as a process-oriented orchestration approach that separates core business processes from system variability at the end-user’s level, where the focus is towards achieving business goals. A fundamental challenge of software engineering is to correctly align business goals with IT strategy, and as such we present an encoding of StPowla to SRML. This provides a formal framework for StPowla and also a separated view of policies representing system variability that is not present in SRML.     

Rigorous evaluation of COTS middleware technology

The adoption of commercial off-the-shelf middleware products across the software industry has gathered significant momentum. While COTS middleware products demonstrably solve many problems, their adoption and use are by no means straightforward. Competition among products that apparently offer identical services complicates the COTS middleware selection process, especially when competing products provide different implementations of standards-based technologies, such as CORBA and Java 2 Enterprise Edition. The article discusses the Middleware Technology Evaluation project, which represents a significant attempt to provide rigorously derived, in-depth evaluations of technology for use by middleware product adopters.     

Enzyme-aided investigation of the substituent distribution in cationic potato amylopectin starch

The distribution of substituents along the polymer chain in cationic potato amylopectin starch, modified in solution, granular slurry, or dry state, was investigated. The starch derivatives were successively hydrolyzed by different enzymes, followed by characterization of the hydrolysis products obtained by means of electrospray mass spectrometry (ESI-MS) and matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). ESI-MS and MALDI-MS were proved to be appropriate techniques for identification of the substituted hydrolysis products, for which there are no standard compounds available. No highly substituted oligomers were found in the hydrolysates, which was taken as an indication of a more or less homogeneous distribution of cationic groups in the amylopectin molecules. Furthermore, from the results obtained it was suggested that the enzymes cleave glucosidic linkages only between unsubstituted glucose units and, preferentially, linkages in sequences containing more than two adjacent unsubstituted units. The determination of the amount of unsubstituted glucose produced from every successive hydrolysis step revealed slight differences between the different starch samples with respect to the homogeneity of the substitution pattern. Among the three samples under investigation, starch cationized in solution was found to have the most and dry-cationized starch the least homogeneous distribution of substituents.     

Charge ratio mass spectrometry of heavy elements

A simple method of stable element assay at the parts per billion level using a sequence of charge changes at MeV ion energies has been demonstrated. Isotopic ratios and abundances of platinum have been studied using this technique in nickel sulphide and copper samples. Silver isotopic distributions have also been investigated in a number of terrestrial and meteoritic materials. A similar charge changing sequence between electrostatic analyzers at keV ion energies was shown to reduce backgrounds for a mass independent search of fractionally charged particles.The methods described form the bases of a broad band mass spectroscopic system under development at IsoTrace.     

Sex pheromone-induced chemolocation in the male American cockroach,Periplaneta americana

Males of the American cockroach,Periplaneta americana, have evolved an efficient search strategy enabling them to locate a source of sex pheromone in the absence of directional information derived from wind. Since these animals are able to utilize chemotaxis to orient almost directly to the source from 45–50 cm away, it is only necessary that they maximize their chances of getting within that range once they perceive the pheromone. They accomplish this by: (1) increasing their overall levels of activity and (2) initiating local search. In this way, they are able to cover a rather large area in a short period of time, i.e., before the source female changes location. If their paths take them to within 45 cm of the source, they are able to locate it soon thereafter. It is probable that very similar strategies are utilized by many other nonflying insects to locate sources of airborne odors.     

Nationwide buildings energy research enabled through an integrated data intensive

Modern workflow systems can enable scientists to run ensemble simulations at unprecedented scales and levels of complexity, allowing them to study system sizes previously impossible to achieve. However as a result of these new capabilities the science teams suddenly also face unprecedented data volumes that they are unable to analyze with their existing tools and methodologies in a timely fashion. In this paper we describe the ongoing development work to create an integrated data intensive scientific workflow and analysis environment that offers researchers the ability to easily create and execute complex simulation studies and provides them with different scalable methods to analyze the resulting data volumes. The capabilities of the new environment are demonstrated on a use case that focuses on building energy modeling. As part of the PNNL research initiative PRIMA (Platform for Regional Integrated Modeling and Analysis) the team performed an initial 3-year study of building energy demands for the US Eastern Interconnect domain. They are now planning to extend to predict the demand for the complete century. In the 3-year study the team simulated 2000 individual building types for 100 independent climate similar regions (600 000 individual runs) raising their data demands from a few MBs to 400 GB for the 3-year study.     

Inhibition of neuronal high voltage-activated calcium channels by insect peptides: a comparison with the actions of omega-conotoxin GVIA

The whole cell variant of the patch clamp technique was used to investigate the actions of two novel insect peptides on high voltage-activated Ca2+ currents in cultured dorsal root ganglion (DRG) neurones. The insect peptides (PMP-D2 and PMP-C) were isolated originally from insect brains and fat bodies, and have been found to have similar three-dimensional structures to the N-type Ca2+ channel inhibitor omega-conotoxin GVIA (omega-CgTx GVIA). High voltage-activated Ca2+ currents were activated from a holding potential of -90 mV by depolarizing step commands to 0 mV. Extracellular application of synthetic PMP-D2 or PMP-C (1 microM) attenuated high voltage-activated Ca2+ currents. The effects of PMP-C were strongly dependent on the frequency of current activation, but inhibition was apparent and reached a steady state after 20 steps when currents were evoked for 30 msec at 0.1 Hz. The actions of the two insect peptides overlapped both with each other and with omega-CgTx GVIA, suggesting that N-type Ca2+ current was predominantly sensitive to these peptides. Low voltage-activated T-type current and 1,4-dihydropyridine sensitive L-type Ca2+ currents were insensitive to 1 microM PMP-D2 and PMP-C, which indicates a degree of selectivity. The presence of a fucose group on PMP-C abolished the ability of this peptide to attenuate high voltage-activated Ca2+ currents, which may reflect a mechanism by which peptide function could be regulated in insects. The electrophysiological data are supported by studies on 45Ca2+ influx into rat cerebrocortical synaptosomes. Both PMP-D2 (10 microM), PMP-C (10 microM) and omega-CgTx GVIA (1 microM) attenuated a proportion of 45Ca2+ influx into the synaptosomes, but additive effects of these peptides were not observed. We conclude that these naturally occurring peptides obtained from invertebrate preparations have inhibitory effects on N-type Ca2+ channels. Although the peptides have related three-dimensional structures, they have distinct amino acid sequences and appear to have different mechanisms of action to produce inhibition of mammalian neuronal high voltage-activated Ca2+ channels.     

User control of electronic component reliability in spacecraft applications

This paper elucidates the role of the electronic component engineer in ensuring the reliability of electronic components for high reliability spacecraft applications. The reliability of electronic components is categorized in three areas of responsibility, attributable to the component manufacturer, the user and a shared responsibility between the two. The broad scope of the component engineer's responsibility extends from circuit design to system operation. Co-operation with circuit design engineers for proper part application is emphasized, and the requirements for understanding the effects of environmental stresses on device material properties is treated. The importance of a close working relationship between the component engineer and the part supplier is also emphasized.