30 research outputs found
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Using abuse frames to bound the scope of security problems
Security problems arise from the concern for
protecting assets from security threats. In a systems
development process, the security protection of a system
is specified by security requirements, identified from the
analysis of the threats to the system. However, as it is
often not possible to obtain a full system description until
late in the RE process, a security problem often has to be
described in the context of a bounded scope, that is, one
containing only the domains relevant to some part of the
functionality of the full system. By binding the scope of a
security problem, it can be described more explicitly and
precisely, thereby facilitating the identification and
analysis of threats, which in turn drive the elicitation and
elaboration of security requirements. In this poster, we
elaborate on an approach we developed based on abuse
frames and suggest how it can provide a means for
structuring and bounding the scope security problems
Effects of Anacetrapib in Patients with Atherosclerotic Vascular Disease
BACKGROUND:
Patients with atherosclerotic vascular disease remain at high risk for cardiovascular events despite effective statin-based treatment of low-density lipoprotein (LDL) cholesterol levels. The inhibition of cholesteryl ester transfer protein (CETP) by anacetrapib reduces LDL cholesterol levels and increases high-density lipoprotein (HDL) cholesterol levels. However, trials of other CETP inhibitors have shown neutral or adverse effects on cardiovascular outcomes.
METHODS:
We conducted a randomized, double-blind, placebo-controlled trial involving 30,449 adults with atherosclerotic vascular disease who were receiving intensive atorvastatin therapy and who had a mean LDL cholesterol level of 61 mg per deciliter (1.58 mmol per liter), a mean non-HDL cholesterol level of 92 mg per deciliter (2.38 mmol per liter), and a mean HDL cholesterol level of 40 mg per deciliter (1.03 mmol per liter). The patients were assigned to receive either 100 mg of anacetrapib once daily (15,225 patients) or matching placebo (15,224 patients). The primary outcome was the first major coronary event, a composite of coronary death, myocardial infarction, or coronary revascularization.
RESULTS:
During the median follow-up period of 4.1 years, the primary outcome occurred in significantly fewer patients in the anacetrapib group than in the placebo group (1640 of 15,225 patients [10.8%] vs. 1803 of 15,224 patients [11.8%]; rate ratio, 0.91; 95% confidence interval, 0.85 to 0.97; P=0.004). The relative difference in risk was similar across multiple prespecified subgroups. At the trial midpoint, the mean level of HDL cholesterol was higher by 43 mg per deciliter (1.12 mmol per liter) in the anacetrapib group than in the placebo group (a relative difference of 104%), and the mean level of non-HDL cholesterol was lower by 17 mg per deciliter (0.44 mmol per liter), a relative difference of -18%. There were no significant between-group differences in the risk of death, cancer, or other serious adverse events.
CONCLUSIONS:
Among patients with atherosclerotic vascular disease who were receiving intensive statin therapy, the use of anacetrapib resulted in a lower incidence of major coronary events than the use of placebo. (Funded by Merck and others; Current Controlled Trials number, ISRCTN48678192 ; ClinicalTrials.gov number, NCT01252953 ; and EudraCT number, 2010-023467-18 .)
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The Problem of Reproducibility
In this article, I look at the issue of reproducibility in science, concentrating on omics- and medicine-based research work. In a sense I am (to quote a British saying) ‘teaching my grandmother to suck eggs’ since many of you, as statisticians, will have this as your central tenet. However, I hope I might describe some ideas and materials that are new to you—at least partially. Ideas which you might like to share with non-statisticians
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The Re-development of a Problem System
The Integrated Children's System is a set of computer programs that are used to chronicle the interaction between British social workers and children in need. It has been the subject of many criticisms from social workers , a major trade union and social work academics. This article details a redevelopment of the system that removes the problems with the system and demonstrates the advantages that can be gained in development by employing readily available open-source software. The redevelopment ignored the implementation directive in the specification for a record-based system. The advantages are twofold: first it removes the major problems with the system and, second, does it for a fraction of the £80-100m original cost (the article estimates the full cost of the redevelopment to be c £35k). The article is important in that it details a major reuse effort which resulted in very large savings; describes an approach to software development for human-centred applications that is radically different to the forms, relational database, Java/PHP approach; and is one of the first case studies which shows the dramatic effects of employing open-source software
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Latent Error Analysis and Child-Care Chronicling Systems
Munro (Munro, 2005) and others have made the point that approaches to investigating child abuse deaths have concentrated on surfae issues where human error is regarded as the terminating point in an investigation. This article describes the use of an approach to accounts of serious abuse that is systemic. The approach is based on one that is used by Boeing, the aircraft manufacturer, to trace back problems to latent errors. The context here is in the development of a set of properties for a computer system that is used for chronicling the interactioni between a child and their family, relevant professionals and agencies. Boeing would normally use an aircraft incident report, accident report or an informal description of a set of incidents as their starting point. The research detailed here uses the report of the Victoria Climbie inquiry. The properties developed from this exercise are then compared with the specificaiton of the Integrated Children's System (ICS), a British chronicling system that has had major problems assocaited with it. It is posited that a systemic approach would have eliminated many of the problems with the ICS requirements specification. Although this article describes one system that is extant in two countries it is general in nature in that the principles hold for any chronicling system, for example those used in other branches of social work areas, and is not specific to England and Wales, the countries whose social workers employ computer systems associated with ICS
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Victoria Climbié, Baby P and the Technological Shackling of British Childrens' Social Work
A computer system known as the Integrated Children's System (ICS) was specified by that part of the British government responsible for child welfare-the Department for Children, Families and Schools (DCSF). The specification was developed in response to the failings of a number of agencies that could have prevented the death of a young child Victoria Climbié. The system specification gave rise to a number of implementations that were deployed in all but one of the local authority departments associated with children's welfare. It did not prevent a second death. This article shows that whatever criterion you use to judge the ICS it failed-not just in terms of preventing the second death, but in terms of its usability, fitness for purpose and efficiency. The article is a chronicle of the events that lead up to the development of the ICS starting with the death of Victoria Climbié and the deployment of a flawed system and concludes with the aftermath following the death of a child known as Baby P. Most of the literature on ICS has concentrated on the deleterious effects on social workers. This article looks at some of the reasons why it is defective. It concludes with two simple solutions. Although in financial terms the failure of ICS is small compared with other system failures in government , in terms of its effect of a whole profession responsible for the care of young people at risk it is large. While this article deals with one particular human-centred systems failure in the United Kingdom its lessons are general and not just specific to a British context
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Heuristics and Software Design - A Case Study
This article describes a case study in which a software system costing hundreds of thousands of pounds was redesigned and re-implemented using a series of heuristics due to the Hungarian mathematician George Pólya. The heuristics are first outlined by applying some of the more important ones to a small programming problem. Then the application of the heuristics applied to the redesign of the system is detailed. Because of the attention to abstraction the resulting system is able to be used in a variety of applications-not just the one that it was envisaged for
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Social Work, Chronicling and the Internet Age
Many of the IT systems that are used by social workers are typical of those that were developed before the Internet became a part of everyday life. This article examines a number of developments-in terms of users, technical facilities and environment-that have been enabled by the Internet and describes a system for social work chronicling that reflects them. The context is that of the computer systems used to support the British Integrated Children's System (ICS); this was a set of business processes that were supported by computer programs that reflected an industrial, pre-Internet approach. The article looks briefly at ICS, examines a series of Internet-affected developments and finally describes a chronicling system suitable for any branch of social work that reflects these developments. Although ICS is used as an exemplar in how not to develop a modern system, the major points made in this article are relevant to all forms of social work and are also not just relevant to a British context.
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The effectiveness of t-way test data generation
This paper reports the results of a study comparing the effectiveness of automatically generated tests constructed using random and t-way combinatorial techniques on safety related industrial code using mutation adequacy criteria. A reference point is provided by hand generated test vectors constructed during development to establish minimum acceptance criteria. The study shows that 2-way testing is not adequate measured by mutants kill rate compared with hand generated test set of similar size, but that higher factor t-way test sets can perform at least as well. To reduce the computation overhead of testing large numbers of vectors over large numbers of mutants a staged optimising approach to applying t-way tests is proposed and evaluated which shows improvements in execution time and final test set size