Correctness of Generalisation and Customisation of Concurrent Model Synchronisation Based on Triple Graph Grammars

Triple graph grammars (TGGs) have been successfully applied to specify and analyse bidirectional model transformations. Recently, a formal approach to concurrent model synchronisation has been presented, where a source and a target modification have to be synchronised simultaneously. In this approach, conflicts between the given and propagated source or target model modifications are taken into account. A semi-automatic conflict resolution strategy is proposed, where a formal resolution strategy can be combined with a user-specific strategy. Up to now, our approach requires deterministic propagation operations. In this paper, we want to relax this condition and also consider non-deterministic (conflicting) operations which might require backtracking. For optimisation, we propose to eliminate conflicts between the operational rules of a TGG using the concept of filter NACs. Nevertheless, concurrent synchronisation is non-deterministic from a user perspective: The user may choose between forward synchronisation and backward synchronisation. Moreover, the conflict resolution strategy may result in several solutions from which the user has to select the most adequate one. Hence, we discuss different kinds of customisation of the synchronisation process and explain the impacts of the different strategies

Accretion disk warping by resonant relaxation: The case of maser disk NGC4258

The maser disk around the massive black hole (MBH) in active galaxy NGC 4258 exhibits an O(10 deg) warp on the O(0.1 pc) scale. The physics driving the warp are still debated. Suggested mechanisms include torquing by relativistic frame dragging or by radiation pressure. We propose here a new warping mechanism: resonant torquing of the disk by stars in the dense cusp around the MBH. We show that resonant torquing can induce such a warp over a wide range of observed and deduced physical parameters of the maser disk.Comment: 4 pp, 2 figure

Observational Evidence for Massive Black Holes in the Centers of Active Galaxies

Naturally occurring water vapor maser emission at 1.35 cm wavelength provides an accurate probe for the study of accretion disks around highly compact objects, thought to be black holes, in the centers of active galaxies. Because of the exceptionally fine angular resolution, 200 microarcseconds, obtainable with very long baseline interferometry, accompanied by high spectral resolution, < 0.1 km/s, the dynamics and structures of these disks can be probed with exceptional clarity. The data on the galaxy NGC4258 are discussed here in detail. The mass of the black hole binding the accretion disk is 3.9 times 10^7 solar masses. Although the accretion disk has a rotational period of about 800 years, the physical motions of the masers have been directly measured with VLBI over a period of a few years. These measurements also allow the distance from the earth to the black hole to be estimated to an accuracy of 4 percent. The status of the search for other maser/black hole candidates is also discussed.Comment: 24 pages, 11 figures, latex, uses aaspp4 style file. To be published in the Journal of Astronomy and Astrophysics (India), proceedings of the Discussion Meeting on the Physics of Black Holes, Bangalore, India: December 199

Reduced Reactivation from Dormancy but Maintained Lineage Choice of Human Mesenchymal Stem Cells with Donor Age

Mesenchymal stem cells (MSC) are promising for cell-based regeneration therapies but up to date it is still controversial whether their function is maintained throughout ageing. Aim of this study was to address whether frequency, activation in vitro, replicative function, and in vitro lineage choice of MSC is maintained throughout ageing to answer the question whether MSC-based regeneration strategies should be restricted to younger individuals. MSC from bone marrow aspirates of 28 donors (5–80 years) were characterized regarding colony-forming unit-fibroblast (CFU-F) numbers, single cell cloning efficiency (SSCE), osteogenic, adipogenic and chondrogenic differentiation capacity in vitro. Alkaline phosphatase (ALP) activity, mineralization, Oil Red O content, proteoglycan- and collagen type II deposition were quantified. While CFU-F frequency was maintained, SSCE and early proliferation rate decreased significantly with advanced donor age. MSC with higher proliferation rate before start of induction showed stronger osteogenic, adipogenic and chondrogenic differentiation. MSC with high osteogenic capacity underwent better chondrogenesis and showed a trend to better adipogenesis. Lineage choice was, however, unaltered with age. Conclusion: Ageing influenced activation from dormancy and replicative function of MSC in a way that it may be more demanding to mobilize MSC to fast cell growth at advanced age. Since fast proliferation came along with high multilineage capacity, the proliferation status of expanded MSC rather than donor age may provide an argument to restrict MSC-based therapies to certain individuals

GWAS meta-analysis of over 29,000 people with epilepsy identifies 26 risk loci and subtype-specific genetic architecture

Epilepsy is a highly heritable disorder affecting over 50 million people worldwide, of which about one-third are resistant to current treatments. Here we report a multi-ancestry genome-wide association study including 29,944 cases, stratified into three broad categories and seven subtypes of epilepsy, and 52,538 controls. We identify 26 genome-wide significant loci, 19 of which are specific to genetic generalized epilepsy (GGE). We implicate 29 likely causal genes underlying these 26 loci. SNP-based heritability analyses show that common variants explain between 39.6% and 90% of genetic risk for GGE and its subtypes. Subtype analysis revealed markedly different genetic architectures between focal and generalized epilepsies. Gene-set analyses of GGE signals implicate synaptic processes in both excitatory and inhibitory neurons in the brain. Prioritized candidate genes overlap with monogenic epilepsy genes and with targets of current antiseizure medications. Finally, we leverage our results to identify alternate drugs with predicted efficacy if repurposed for epilepsy treatment

Towards Domain Completeness for Model Transformations Based on Triple Graph Grammars

The analysis of model transformations is a challenging research area within model driven engineering. Triple graph grammars (TGGs) have been applied in various transformation scenarios and their formal foundation has been a vital ground for general results concerning notions of correctness and completeness. This paper addresses existing gaps between practical scenarios and the formal results of TGGs concerning the notion of completeness. Since the source domain language of a model transformation is usually specified independently from the TGG, we use the notion of domain completeness, which requires that the model transformation has to provide a corresponding target model for each model of the source domain language. As main result, we provide a general method for showing that the source domain language is included in the language that is generated by the source rules of the TGG. This provides the first of two components for verifying domain completeness. The running example is the well studied object-relational mapping

Solving the FIXML2Code-case Study with HenshinTGG

Triple graph grammars (TGGs) provide a formal framework for bidirectional model transformations. As in practice, TGGs are primarily used in pure model-to-model transformation scenarios, tools for text-to-model and model-to-text transformations make them also applicable in text-to-text transformation contexts. This paper presents a solution for the text-to-text transformation case study of the Transformation Tool Contest 2014 on translating FIXML (an XML notation for financial transactions) to source code written in Java, C# or C++. The solution uses the HenshinTGG tool for specifying and executing model-to-model transformations based on the formal concept of TGGs as well as the Xtext tool for parsing XML content to yield its abstract syntax tree (text-to-model transformation) and serialising abstract syntax trees to source code (model-to-text transformation). The approach is evaluated concerning a given set of criteria

An Approach Using Formally Well-founded Domain Languages for Secure Coarse-grained IT System Modelling in a Real-world Banking Scenario Abstract

In this paper we show how distributed coarse-grained IT systems in a real-world banking scenario can be modelled using domain concepts and languages that are standing on top of formal methods. We further show how these methods help to enforce structural security requirements, like firewall placements. In contrast to today’s diagrams of IT landscapes, this approach makes use of the full power of formal methods, being at the same time completely transparent to the people using it in the scenario. This is what makes this theoretical approach applicable in a real-world environment where people are highly sensitive to set-up costs and any daily operational overhead

PERFORMANCE, PATIENT BENEFITS AND ACCEPTANCE OF A NEW GENERATION OF MICROPROCESSOR-CONTROLLED STANCE AND SWING CONTROL ORTHOSIS

INTRODUCTION By enabling users to flex the orthotic leg during swing phase and safely lock it during stance phase, stance control orthosis (SCO) offers clear benefits compared to locked knee-ankle-foot-orthosis (KAFO)1. Since such orthoses do not offer dampened knee flexion in the weight-bearing condition, this represents a limitation in everyday activities such as ramp and stair descent. C-Brace, a microprocessor controlled stance and swing orthosis (SSCO), overcomes many of those problems. Maximum knee flexion angle in stance and swing phase during level walking are closer to physiological values with C-Brace compared to conventional KAFOs2. The patients are with C-Brace able to descend stairs and ramps reciprocally2. Furthermore, patients report of safer and easier ability to perform activities of daily living3. The main aim of next generation C-Brace is a reduction in size and an increase of adaptability to the patient’s anatomic structure. Due to technological changes, improvements especially for difficult ADLs (e.g. walking on uneven ground) are expected. Abstract PDF&nbsp; Link: https://jps.library.utoronto.ca/index.php/cpoj/article/view/32020/24438 How to cite:&nbsp;Wismer N, Krebs A, Braatz F, Schmalz T, Kranzl A, Breuer C. PERFORMANCE, PATIENT BENEFITS AND ACCEPTANCE OF A NEW GENERATION OF MICROPROCESSOR-CONTROLLED STANCE AND SWING CONTROL ORTHOSIS. CANADIAN PROSTHETICS &amp; ORTHOTICS JOURNAL, VOLUME 1, ISSUE 2, 2018; ABSTRACT, POSTER PRESENTATION AT THE AOPA’S 101ST NATIONAL ASSEMBLY, SEPT. 26-29, VANCOUVER, CANADA, 2018.DOI: https://doi.org/10.33137/cpoj.v1i2.32020 Abstracts were Peer-reviewed by the American Orthotic Prosthetic Association (AOPA) 101st National Assembly Scientific Committee.&nbsp; http://www.aopanet.org