134 research outputs found

    The WISENT Grid Architecture: Coping with Firewalls and NAT

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    In energy meteorology research, scientists from several domains such as physics, meteorology and electrical engineering work together to obtain information needed to characterize energy production from regenerative energy sources such as wind and solar power. For this purpose, several scientific applications were developed to process large data sets from heterogenous data sources in complex and sometimes long-running process chains. In our project WISENT a Grid infrastructure is created to speed up execution of these applications and to ease access to computational and data resources. To achieve this goal, Grid software such as Globus Toolkit and Condor is employed to connect the existing resources of each project partner. But this ongoing process is hindered by blocking firewalls due to strong security policies and by the use of network address translation (NAT). In this paper we describe the current Grid architecture and focus on problems that occurred due to the use of firewalls and NAT. We contribute our present solutions and also discuss alternative solution ideas. One solution using the so-called “hole punching” technology is described in more detail

    Investigating Strategies for Cooperative Planning of Independent Agents through Prototype Evaluation

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    This paper discusses the application of the prototyping approach to investigating the requirements on strategies for cooperative planning and conflict resolution of independent agents by means of an example application: the strategic game "Scotland Yard". The strategies for coordinating the agents, which are parallel algorithms, are developed with a prototyping approach using ProSet-Linda. ProSet-Linda designed for prototyping parallel algorithms. We concentrate o

    P110 and P140 Cytadherence-Related Proteins Are Negative Effectors of Terminal Organelle Duplication in Mycoplasma genitalium

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    BACKGROUND:The terminal organelle is a complex structure involved in many aspects of the biology of mycoplasmas such as cell adherence, motility or cell division. Mycoplasma genitalium cells display a single terminal organelle and duplicate this structure prior to cytokinesis in a coordinated manner with the cell division process. Despite the significance of the terminal organelle in mycoplasma virulence, little is known about the mechanisms governing its duplication. METHODOLOGY/PRINCIPAL FINDINGS:In this study we describe the isolation of a mutant, named T192, with a transposon insertion close to the 3' end of the mg192 gene encoding for P110 adhesin. This mutant shows a truncated P110, low levels of P140 and P110 adhesins, a large number of non-motile cells and a high frequency of new terminal organelle formation. Further analyses revealed that the high rates of new terminal organelle formation in T192 cells are a direct consequence of the reduced levels of P110 and P140 rather than to the expression of a truncated P110. Consistently, the phenotype of the T192 mutant was successfully complemented by the reintroduction of the mg192 WT allele which restored the levels of P110 and P140 to those of the WT strain. Quantification of DAPI-stained DNA also showed that the increase in the number of terminal organelles in T192 cells is not accompanied by a higher DNA content, indicating that terminal organelle duplication does not trigger DNA replication in mycoplasmas. CONCLUSIONS/SIGNIFICANCE:Our results demonstrate the existence of a mechanism regulating terminal organelle duplication in M. genitalium and strongly suggest the implication of P110 and P140 adhesins in this mechanism

    Do semantic standards lack quality? : a survey among 34 semantic standards

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    The adoption of standards to improve interoperability in the automotive, aerospace, shipbuilding and other sectors could save billions. While interoperability standards have been created for a number of industries, problems persist, suggesting a lack of quality of the standards themselves. The issue of semantic standard quality is not often addressed. In this research we take a closer look at the quality of semantics standards, development processes, and survey the current state of the quality of semantic standards by means of a questionnaire that was sent to standards developers. This survey looked at 34 semantic standards, and it shows that the quality of semantic standards for inter-organizational interoperability can be improved. Improved standards may advance interoperability in networked business. Improvement of semantic standards requires transparency of their quality. Although many semantic standard development organisations already have quality assurance in place, this research shows that they could benefit from a quality measuring instrument

    An environment for sustainable research software in Germany and beyond: current state, open challenges, and call for action

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    Research software has become a central asset in academic research. It optimizes existing and enables new research methods, implements and embeds research knowledge, and constitutes an essential research product in itself. Research software must be sustainable in order to understand, replicate, reproduce, and build upon existing research or conduct new research effectively. In other words, software must be available, discoverable, usable, and adaptable to new needs, both now and in the future. Research software therefore requires an environment that supports sustainability. Hence, a change is needed in the way research software development and maintenance are currently motivated, incentivized, funded, structurally and infrastructurally supported, and legally treated. Failing to do so will threaten the quality and validity of research. In this paper, we identify challenges for research software sustainability in Germany and beyond, in terms of motivation, selection, research software engineering personnel, funding, infrastructure, and legal aspects. Besides researchers, we specifically address political and academic decision-makers to increase awareness of the importance and needs of sustainable research software practices. In particular, we recommend strategies and measures to create an environment for sustainable research software, with the ultimate goal to ensure that software-driven research is valid, reproducible and sustainable, and that software is recognized as a first class citizen in research. This paper is the outcome of two workshops run in Germany in 2019, at deRSE19 - the first International Conference of Research Software Engineers in Germany - and a dedicated DFG-supported follow-up workshop in Berlin
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