Well-formed Model Co-evolution with Customizable Model Migration

Model-driven engineering (MDE) is a software engineering discipline which focuses on models as the primary artifact of the software development process while programs are mainly generated by means of model-to-code transformations. In particular, modeling languages tailored to specific domains promise to increase the productivity and quality of software. Nevertheless due to e.g. evolving requirements, modeling languages evolve and existing models have to be migrated. Corresponding manual model migration is tedious and error-prone, therefore tools have been developed to (partly) automate this process. We follow the idea of considering such modeling language and model co-evolutions as related graph transformations ensuring a correct and unique typing of migrated models. In this paper, we present a general and formal construction of well-formed model migration schemes that are able to co-adapt any model of a given modeling language to a performed meta-model change. We show how appropriate model migration schemes can be constructed and discuss how they may be customized

A database model for object dynamics.

Object-oriented database systems, Dynamic object re-classification, Object role model, Dynamic class hierarchy, Object migration

Using Data in Undergraduate Science Classrooms

Provides pedagogical insight concerning the skill of using data The resource being annotated is: http://www.dlese.org/dds/catalog_DATA-CLASS-000-000-000-007.htm

The role of ependymoglial cells in the regeneration of zebrafish telencephalon

Achieving successful brain regeneration in humans is currently one of the biggest challenges in the field of regeneration studies. In contrast, regeneration competent species such as the zebrafish, have a remarkable capacity for regeneration and neurogenesis after injury. Ependymoglial cells of the zebrafish brain, among which a subset act as progenitors, react to an injury and generate new neurons that subsequently migrate towards the lesion site and contribute to repair. Understanding the cellular and molecular details of regeneration in zebrafish could potentially offer targets for therapeutically relevant interventions in humans. In order to study ependymoglia behavior in depth, I developed an electroporation technique to reliably label high numbers of ependymoglial cells in vivo. Additionally, I adapted functional usage of StagR-Cas9 method in the adult zebrafish telencephalon in vivo, which allowed us to genetically manipulate multiple genes in ependymoglial cells. I then used the developed live imaging methodology to analyze the diversity of ependymoglial response to injury in the Tg (gfap:GFP) zebrafish line and discovered two subpopulations of ependymoglial cells – GFP high and GFP low with their different reactions. I observed that the GFP low subpopulation directly converts to post-mitotic neurons in response to the injury and engages in restorative neurogenesis. To understand the molecular mechanisms underlying successful regenerative neurogenesis, I focused on the behavior of the GFP low ependymoglia. I made use of the existing transcriptome analysis of this glial population and identified aryl hydrocarbon receptor (AhR) to be involved in regulation of ependymoglia behavior after injury. More specifically, inactivation of AhR signaling shortly after the injury promoted ependymoglia proliferation, whereas return of AhR to basal levels - around 7 days post-injury, promoted direct conversion of ependymoglial cells into neurons. Moreover, I was able to show that GFP low ependymoglia have high AhR signaling levels and regulate it in response to the injury. Interfering with proper regulation of AhR signaling after the injury led to inappropriate timing of generation of new-neurons and failed restorative neurogenesis. Taken together, the core data I present in this thesis identified AhR to be an important regulator of ependymoglia behavior and their timely coordination after the injury. More precisely, AhR is a crucial factor involved in proper timing of restorative neurogenesis and successful regeneration in zebrafish, which has insofar been previously unknown

Trends in bone metastasis modeling

Bone is one of the most common sites for cancer metastasis. Bone tissue is composed by different kinds of cells that coexist in a coordinated balance. Due to the complexity of bone, it is impossible to capture the intricate interactions between cells under either physiological or pathological conditions. Hence, a variety of in vivo and in vitro approaches have been developed. Various models of tumor\u2013bone diseases are routinely used to provide valuable information on the relationship between metastatic cancer cells and the bone tissue. Ideally, when modeling the metastasis of human cancers to bone, models would replicate the intra-tumor heterogeneity, as well as the genetic and phenotypic changes that occur with human cancers; such models would be scalable and reproducible to allow high-throughput investigation. Despite the continuous progress, there is still a lack of solid, amenable, and affordable models that are able to fully recapitulate the biological processes happening in vivo, permitting a correct interpretation of results. In the last decades, researchers have demonstrated that three-dimensional (3D) methods could be an innovative approach that lies between bi-dimensional (2D) models and animal models. Scientific evidence supports that the tumor microenvironment can be better reproduced in a 3D system than a 2D cell culture, and the 3D systems can be scaled up for drug screening in the same way as the 2D systems thanks to the current technologies developed. However, 3D models cannot completely recapitulate the inter-and intra-tumor heterogeneity found in patients. In contrast, ex vivo cultures of fragments of bone preserve key cell\u2013cell and cell\u2013matrix interactions and allow the study of bone cells in their natural 3D environment. Moreover, ex vivo bone organ cultures could be a better model to resemble the human pathogenic metastasis condition and useful tools to predict in vivo response to therapies. The aim of our review is to provide an overview of the current trends in bone metastasis modeling. By showing the existing in vitro and ex vivo systems, we aspire to contribute to broaden the knowledge on bone metastasis models and make these tools more appealing for further translational studies

From EGEE OPerations Portal towards EGI OPerations Portal

International audienceEGEE to EGI structure based on NGIs evolution induces a large move from the operations that will rely on a sustainable and largely decentralized model. One of the key evolutions for the challenge in the regionalisation relies in the scalability and the flexibility required regarding information source types and information handling. For 5 years, we have developed and maintained a standard-based component that allows us to address both theses issues. This open-source tool, named Lavoisier, has been a critical success factor for the operations dashboard, one of the Operations Portal main features. Indeed, it enables coherent efficient and reliable data handling which is customizable and scalable, as Lavoisier is an extensible service designed to provide a unified view of data collected from multiple heterogeneous data sources. Data views are represented and accessed as XML documents through standard languages such as XSLT, XPath. Moreover, scalability and reliability are enforced by a caching mechanism adaptable to specific data sources and use-cases. We will namely expose how the concept and the implementation enable clear roles separation between plug-in developer, service configuration administrator or end-user. Also, maintainability of the portal code has increased dramatically as the latter is now independent from the data sources technology or from the cache management policies. Finally, integration of data has recently been simplified as the service administrator proceeds now through web interface