Low cost first class functions

We describe a. new approach to implementing functions as first class values. Using this technique, there is no additional overhead imposed for the most common case, that of non-nested functions bound at compile time. Invoking function values assigned to variables requires two additional instructions. It is only when functions are invoked which contain nested functions that can outlive their defining context that the full overhead of the construction of dynamic closures is required. The approach is being used in a new strongly typed compiled multi-paradigm programming language being developed by the author

A multiprocessor implementation of Little Smalltalk

In this project we have attempted to exploit the parallel programming features of a Sequent Balance multiprocessor to improve the performance of a Smalltalk interpreter. The block construct and the fork message together make Smalltalk a 'natural' parallel programming language. We describe how processes can be created from within the Smalltalk system to execute concurrently on different processors while sharing a common object memory. We have described a suite of programs that were run to test the implementation and we report the results of the benchmark tests

OSU v 3.0 Browser : window into GUI applications

Graphical user interface (GUI) applications based on object-oriented design are difficult to build without a supportive tool to graphically visualize the structure of the entire application. As an application becomes larger and more complex, it becomes harder to visualize its class hierarchy. Several systems, such as Smalltalk, MacApp, THINK C 5.0 and THINK Pascal, have provided powerful tools for this visualization. However, none of them can be invoked internally by the Oregon Speedcode Universe version 3.0 (OSU v3.0) supporting tools such as the Petri Net Editor [Keh 91]. The Petri Net Editor needs to view the class hierarchy of an application and obtain information to specify a transition arc, such as the method that sends a message to an object, the class that defines this method. and the path to find the definition of this class. The solution is straight forward: to build our own OSU 3.0 Browser to meet the OSU v3.0 supporting tools' needs. A browser provides a graphical view of the class hierarchy of an entire application and gives a better idea of how the system or the application is structured and how the classes relate to each other. The functionalities of the OSU 3.0 Browser is to parse the C++ source code of the OSU Application Framework, save the necessary information in an internal data structure, display the class hierarchy in a tree chart, and return the path name of the definition of the selected methods to the Petri Net Editor. The Browser is built on the OSU Application Framework [Wittel 91] and integrated with the Petri Net Editor

Machine learning outperforms clinical experts in classification of hip fractures

Hip fractures are a major cause of morbidity and mortality in the elderly, and incur high health and social care costs. Given projected population ageing, the number of incident hip fractures is predicted to increase globally. As fracture classification strongly determines the chosen surgical treatment, differences in fracture classification influence patient outcomes and treatment costs. We aimed to create a machine learning method for identifying and classifying hip fractures, and to compare its performance to experienced human observers. We used 3659 hip radiographs, classified by at least two expert clinicians. The machine learning method was able to classify hip fractures with 19% greater accuracy than humans, achieving overall accuracy of 92%

Towards Symbolic Model-Based Mutation Testing: Combining Reachability and Refinement Checking

Model-based mutation testing uses altered test models to derive test cases that are able to reveal whether a modelled fault has been implemented. This requires conformance checking between the original and the mutated model. This paper presents an approach for symbolic conformance checking of action systems, which are well-suited to specify reactive systems. We also consider nondeterminism in our models. Hence, we do not check for equivalence, but for refinement. We encode the transition relation as well as the conformance relation as a constraint satisfaction problem and use a constraint solver in our reachability and refinement checking algorithms. Explicit conformance checking techniques often face state space explosion. First experimental evaluations show that our approach has potential to outperform explicit conformance checkers.Comment: In Proceedings MBT 2012, arXiv:1202.582

Ki67 Proliferation Index as a Tool for Chemotherapy Decisions During and After Neoadjuvant Aromatase Inhibitor Treatment of Breast Cancer: Results From the American College of Surgeons Oncology Group Z1031 Trial (Alliance)

To determine the pathologic complete response (pCR) rate in estrogen receptor (ER) –positive primary breast cancer triaged to chemotherapy when the protein encoded by the MKI67 gene (Ki67) level was > 10% after 2 to 4 weeks of neoadjuvant aromatase inhibitor (AI) therapy. A second objective was to examine risk of relapse using the Ki67-based Preoperative Endocrine Prognostic Index (PEPI)

Mechanical characterisation of polymer of intrinsic microporosity PIM-1 for hydrogen storage applications

Polymers of intrinsic microporosity (PIMs) are currently attracting interest due to their unusual combination of high surface areas and capability to be processed into free-standing films. However, there has been little published work with regards to their physical and mechanical properties. In this paper, detailed characterisation of PIM-1 was performed by considering its chemical, gas adsorption and mechanical properties. The polymer was cast into films, and characterised in terms of their hydrogen adsorption at −196 °C up to much higher pressures (17 MPa) than previously reported (2 MPa), demonstrating the maximum excess adsorbed capacity of the material and its uptake behaviour in higher pressure regimes. The measured tensile strength of the polymer film was 31 MPa with a Young’s modulus of 1.26 GPa, whereas the average storage modulus exceeded 960 MPa. The failure strain of the material was 4.4%. It was found that the film is thermally stable at low temperatures, down to −150 °C, and decomposition of the material occurs at 350 °C. These results suggest that PIM-1 has sufficient elasticity to withstand the elastic deformations occurring within state-of-the-art high-pressure hydrogen storage tanks and sufficient thermal stability to be applied at the range of temperatures necessary for gas storage applications