Applied metamodelling : a foundation for language driven development

The Third Edition of Applied Metamodelling represents a small increment since the Second Edition was produced in 2008. The book continues to be referenced in schol- arly articles with 212 citations on Google Scholar including nearly 150 since 2008. The open-source release of the accompanying technologies XMF and XMF-Mosaic did not generate the same level of interest, partly due to a lack of exposure and associated tuto- rial materials. Recently, interest in the field of multi-level modelling has increased and has led to publications and a Dagstuhl Seminar based on the ideas of meta-languages and tool-modelling. An overview of the historical development of XMF, the ideas in this book, and the the birth and death of an associated startup company has been published in 2012 as part of the 10th anniversary edition of the the Journal of Software and Systems Modeling. A project based on the foundations developed in this book and the tooling, now rebranded XModeler, is underway and the aim is to advance the field of multi-level language-based system engineering

On the emergent System Mass Function: the contest between accretion and fragmentation

We propose a new model for the evolution of a star cluster's System Mass Function (SMF). The model involves both turbulent fragmentation and competitive accretion. Turbulent fragmentation creates low-mass seed proto-systems (i.e. single and multiple protostars). Some of these low-mass seed proto-systems then grow by competitive accretion to produce the high-mass power-law tail of the SMF. Turbulent fragmentation is relatively inefficient, in the sense that the creation of low-mass seed proto-systems only consumes a fraction, $\sim 23\%$ (at most $\sim 50\%$), of the mass available for star formation. The remaining mass is consumed by competitive accretion. Provided the accretion rate onto a proto-system is approximately proportional to its mass ($dm/dt \propto m$), the SMF develops a power-law tail at high masses with the Salpeter slope ($\sim -2.3$). If the rate of supply of mass accelerates, the rate of proto-system formation also accelerates, as appears to be observed in many clusters. However, even if the rate of supply of mass decreases, or ceases and then resumes, the SMF evolves homologously, retaining the same overall shape, and the high-mass power-law tail simply extends to ever higher masses until the supply of gas runs out completely. The Chabrier SMF can be reproduced very accurately if the seed proto-systems have an approximately log-normal mass distribution with median mass $\sim 0.11 {\rm M}_{_\odot}$ and logarithmic standard deviation $\sigma_{\log_{10}(M/{\rm M}_\odot)}\sim 0.47$).Comment: Accepted for publication in MNRAS. 13 pages, 4 figures, 1 appendi

Key issues in rural health: perspectives of health service providers in Queensland

The Centre for Rural and Remote Area Health (CRRAH) held interactive research workshops in eight towns in Southern Queensland. The purpose of the workshops was to determine what health providers considered were major issues affecting their service and for these results to inform future research strategy of CRRAH. Over 150 organisations identified as either providing health services or having a significant interest in health provision in one or more of the targeted towns were invited to attend. The workshops used the nominal group technique to identify what the participants considered were key health issues in the geographical area in which they worked. These issues were then prioritised by the participants. Thematic analysis of the issues generated a ranking of themes by importance. Results were compared with a similar exercise undertaken in 2003. Participants from organisation directly involved with health care were complemented at the workshops by representatives from local government, the police service and church groups. A total of 85 participants representing 47 services and 41 different organisations attended the eight workshops. Issues generated by the participants were pooled into seventeen themes. Workforce issues were by far the major concern of health providers. Recruitment and retention of health workers were a major concern. The other four highest ranked themes across all workshops were mental health, access to health services, perceptions and expectations of consumers of health services and interagency cooperation. Aged care was an additional theme that generated a lot of concern at several of the workshops. The workshops provided important information to CRRAH for developing research strategy. Additionally, several new alliances among health providers were developed which will support sharing of information and resources. The workshops enabled rural and remote organisations to meet and identify the key health issues and supported research planning. Much need alliances among health providers were forged and collaborative research avenues are being explored. The workshop forum is an excellent means of information exchange

Defining OCL expressions using templates.

OCL expressions are an essential part of UML. The current versions of OCL fail to have a meta-model which means that the integration of OCL with the UML meta-model cannot be formally defined [1]. This can result in ambiguous descriptions of systems which may compromise designs. The need to redesign the OCL has been addressed by a number of proposals submitted to the OMG. In this paper we demonstrate how a definition for OCL can be stamped out from a small number of templates. Such an approach enables a high level of reuse and an increased confidence that the definition is correct. This work forms part of the 2U consortium’s efforts for the definition of UML 2.0

The Origin and Universality of the Stellar Initial Mass Function

We review current theories for the origin of the Stellar Initial Mass Function (IMF) with particular focus on the extent to which the IMF can be considered universal across various environments. To place the issue in an observational context, we summarize the techniques used to determine the IMF for different stellar populations, the uncertainties affecting the results, and the evidence for systematic departures from universality under extreme circumstances. We next consider theories for the formation of prestellar cores by turbulent fragmentation and the possible impact of various thermal, hydrodynamic and magneto-hydrodynamic instabilities. We address the conversion of prestellar cores into stars and evaluate the roles played by different processes: competitive accretion, dynamical fragmentation, ejection and starvation, filament fragmentation and filamentary accretion flows, disk formation and fragmentation, critical scales imposed by thermodynamics, and magnetic braking. We present explanations for the characteristic shapes of the Present-Day Prestellar Core Mass Function and the IMF and consider what significance can be attached to their apparent similarity. Substantial computational advances have occurred in recent years, and we review the numerical simulations that have been performed to predict the IMF directly and discuss the influence of dynamics, time-dependent phenomena, and initial conditions.Comment: 24 pages, 6 figures. Accepted for publication as a chapter in Protostars and Planets VI, University of Arizona Press (2014), eds. H. Beuther, R. S. Klessen, C. P. Dullemond, Th. Hennin

Structural basis for complement factor H-linked age-related macular degeneration

This is the final version of the article. Available from the publisher via the DOI in this record.Nearly 50 million people worldwide suffer from age-related macular degeneration (AMD), which causes severe loss of central vision. A single-nucleotide polymorphism in the gene for the complement regulator factor H (FH), which causes a Tyr-to-His substitution at position 402, is linked to approximately 50% of attributable risks for AMD. We present the crystal structure of the region of FH containing the polymorphic amino acid His402 in complex with an analogue of the glycosaminoglycans (GAGs) that localize the complement regulator on the cell surface. The structure demonstrates direct coordination of ligand by the disease-associated polymorphic residue, providing a molecular explanation of the genetic observation. This glycan-binding site occupies the center of an extended interaction groove on the regulator's surface, implying multivalent binding of sulfated GAGs. This finding is confirmed by structure-based site-directed mutagenesis, nuclear magnetic resonance-monitored binding experiments performed for both H402 and Y402 variants with this and another model GAG, and analysis of an extended GAG-FH complex.B. Prosser is funded by the Wellcome Trust Structural Biology Training Program (075415/Z/04/Z). S. Johnson and P. Roversi were funded by grants to S.M. Lea from the Medical Research Council (MRC) of the United Kingdom (grants G0400389 and G0400775). D. Uhrin and P.N. Barlow were funded by the Wellcome Trust (078780/ Z/05/Z). S.J. Clark was funded by an MRC Doctoral Training Account (G78/7925), and R.B. Sim and A.J. Day were funded by MRC core funding to the MRC Immunochemistry Unit

A pattern based approach to defining the dynamic infrastructure of UML 2.0.

The 2U Consortium has recently submitted a proposal for the definition of the UML 2.0 infrastructure. This uses an innovative technique of rapidly “stamping out” the definition using a small number of patterns commonly found in software architecture. The patterns, their instantiation, and any further language details are described using precise class diagrams and OCL, this enables the definition to be easily understood. The main focus of the 2U approach is on the static part of the definition. A further concern when modelling software, using languages such as the UML, is describing the dynamic behaviour of the system over time. The contribution of this paper is to provide a template that can be used to “stamp out” the dynamic part of the UML 2.0 infrastructure. We argue for the suitability of the dynamic template because it makes little commitment to concrete abstractions and can, therefore, be used to support a broad spectrum of behavioural languages

Designing a Biomimetic Prosthetic Flipper for a Kemp’s Ridley Sea Turtle

Lola is a Kemp’s Ridley sea turtle that has an amputated right pectoral flipper. Our team focused our efforts on creating a lightweight, durable attachment that minimized application time and aligned properly to the residual limb. A final design was created in order to maximize the effectiveness of the device, while maintaining the biomechanics of the original flipper design. This work created a foundation that can be applied to other amputee turtles in order to improve their quality of life