Positioning Verfification in the Context of Software/System Certification

Formal verification applied to software has been seen as an important focus in research for determining the acceptability of that software for use. However, in examining the requirements for determining the safety of a software intensive system for use in critical situations, it is quite clear that verification plays a role,but not necessarily a central role. It is entirely possible that a piece of software satisfies its specification, but is unsafe to use. (The first and foremost reason for this is that the program satisfies an unsafe specification.) In this paper we will address the nature of certification in the context of critical systems, decomposing it,by means of a new philosophical framework, into four aspects: evidence, confidence, determination and certification. Our point of view is that establishing the safety (in a very general sense) of a system is a confidence building exercise much in the same vein as the scientific method; our framework serves as a setting in which we can properly understand and develop such an exercise. We will then place formal verification and assurance cases in this setting, discussing their roles and limitations.Keywords: Software certification, System certification, Formal specification, Verification,Critical systems, Safety, Assurance cases, Safety case

VLT Spectroscopy of Globular Cluster Systems, I. The Photometric and Spectroscopic Dataset

We present Lick line-index measurements of extragalactic globular clusters in seven early-type galaxies (NGC 1380, 2434, 3115, 3379, 3585, 5846, and 7192) with different morphological types (E-S0) located in field and group/cluster environments. High-quality spectra were taken with the FORS2 instrument at ESO's Very Large Telescope. About 50% of our data allow an age resolution dt/t ~ 0.3 and a metallicity resolution ~0.25-0.4 dex, depending on the absolute metallicity. Globular cluster candidates are selected from deep B, V, R, I, K FORS2/ISAAC photometry with 80-100% success rate inside one effective radius. Using combined optical/near-infrared colour-colour diagrams we present a method to efficiently reduce fore-/background contamination down to <10%. We find clear signs for bi-modality in the globular cluster colour distributions of NGC 1380, 3115, and 3585. The colour distributions of globular clusters in NGC 2434, 3379, 5846, and 7192 are consistent with a broad single-peak distribution. For the analysed globular cluster systems the slopes of projected radial surface density profiles, of the form Sigma(R) ~ R^-Gamma, vary between ~0.8 and 2.6. Using globular clusters as a tracer population we determine total dynamical masses of host galaxies out to large radii (~1.6 - 4.8 Reff). For the sample we find masses in the range ~8.8*10^10 Msolar up to ~1.2*10^12 Msolar. The line index data presented here will be used in accompanying papers of this series to derive ages, metallicities and abundance ratios. A compilation of currently available high-quality Lick index measurements for globular clusters in elliptical, lenticular, and late-type galaxies is provided and will serve to augment the current data set. [abridged]Comment: A&A accepted, 42 page

Revised classification of kinases based on bioactivity data: the importance of data density and choice of visualization

RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

Rethinking Professor Westbrook\u27s Two Thoughts about Insider Preferences

status: publishe

Computational tools for the study of the genomes of filamentous fungi

During the past year, we have developed and deployed several new computational tools to provide new means of access to information used for research in the biology of filamentous fungi. These new tools complement and extend other resources available for access to both molecular and biological data

How Peer Support Specialists Uniquely Initiate and Build Connection with Young People Experiencing Homelessness

Young people experiencing homelessness are often apprehensive to engage in conventional service systems due to prior mistreatment by providers and others in their lives, as well as stigma associated with accessing services. Even when relationships between service providers and young people are initiated, they often end prematurely. Mutual aid, or peer-to-peer support, has a long and promising history within the mental health field, yet has received little empirical attention in work with young people experiencing homelessness. The present study used participatory qualitative methods to understand how peers uniquely initiate and build connection with young people experiencing homelessness. Through interviews and journaling with peer support specialists and program staff, this study found that peers initiate relationships with young people by becoming familiar faces in youth spaces, identifying themselves as peers, then formalizing relationships with young people. Peers build connection by showing they are on the “same side of the glass” as young people, establishing autonomy and availability over a preset agenda, and creating containers acceptable for failure. Peers, their supervisors, and organizations building mutual aid programs may consider these findings when working to build programs which flexibly and authentically engage young people experiencing homelessness in meaningful relationships

HI in Early-Type Galaxies

We briefly discuss the main differences between the HI properties of luminous and low-luminosity early-type galaxies. In luminous early-type galaxies the HI is often irregularly distributed, but in a few cases regular HI disks, of low surface density, are seen. In low-luminosity galaxies, the HI is more often in a disk with high central surface densities. This suggests a different evolution of the gas in these two groups of galaxies.Comment: To appear in the proceedings of the conference "Gas and Galaxy Evolution" (ASP Conference Series), eds. J. Hibbard, M. Rupen, and J. van Gorko

Post-weaning housing conditions influence freezing during contextual fear conditioning in adult rats

The present study aimed to investigate the influence of housing conditions on contextual fear memory malleability. Male Wistar rats were housed in enriched, standard, or impoverished conditions after weaning and remained in these conditions throughout the entire experiment. After six weeks into those housing conditions, all animals underwent a 3-day protocol including contextual fear conditioning (day 1), memory reactivation followed by systemic administration of midazolam or vehicle (day 2), and a retention test (day 3). Percentage freezing was used as a behavioral measure of contextual fear. There was no evidence for an effect of housing conditions on the sensitivity of contextual fear memory to amnestic effects of post-reactivation midazolam administration, and no indication for amnestic effects of post-reactivation midazolam overall (including in the standard group). The inability to replicate previous demonstrations of post-reactivation amnesia using the same protocol underscores the subtle nature of post-reactivation pharmacological memory interference. Notably, impoverished housing resulted in a decrease in contextual freezing during contextual fear conditioning, reactivation and retention testing, compared to enriched and standard housing conditions. This observation warrants caution when interpreting the results from experiments regarding effects of housing on fear memory processes, particularly when freezing is used as a measure of fear.Fil: Schroyens, Natalie. Katholikie Universiteit Leuven; BélgicaFil: Bender, Crhistian Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Farmacología Experimental de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Farmacología Experimental de Córdoba; ArgentinaFil: Alfei Palloni, Joaquin Matías. Katholikie Universiteit Leuven; BélgicaFil: Molina, Víctor Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Farmacología Experimental de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Farmacología Experimental de Córdoba; ArgentinaFil: Luyten, Laura. Katholikie Universiteit Leuven; BélgicaFil: Beckers, Tom. Katholikie Universiteit Leuven; Bélgic