On Models and Code:A Unified Approach to Support Large-Scale Deductive Program Verification

Despite the substantial progress in the area of deductive program verification over the last years, it still remains a challenge to use deductive verification on large-scale industrial applications. In this abstract, I analyse why this is case, and I argue that in order to solve this, we need to soften the border between models and code. This has two important advantages: (1) it would make it easier to reason about high-level behaviour of programs, using deductive verification, and (2) it would allow to reason about incomplete applications during the development process. I discuss how the first steps towards this goal are supported by verification techniques within the VerCors project, and I will sketch the future steps that are necessary to realise this goal

2010 SSO John Wayne Clinical Research Lecture: Rectal Cancer Outcome Improvements in Europe: Population-Based Outcome Registrations will Conquer the World

During the past two decades, rectal cancer treatment has improved considerably in Europe. Clinical trials played a crucial role in improving surgical techniques, (neo)adjuvant treatment schedules, imaging, and pathology. However, there is still a wide variation in outcome after rectal cancer. In most western health care systems, efforts are made to reduce hospital variation by focusing on selective referral and encouraging patients to seek care in high-volume hospitals. On the other hand, the expertise for diagnosis and treatment of common types of cancer should be preferably widespread and easily accessible for all patients. As an alternative to volume-based referral, hospitals and surgeons can improve their results by learning from their own outcome statistics and those from colleagues treating a similar patient group. Several European surgical (colo)rectal audits have led to improvements with a greater impact than any of the adjuvant therapies currently under study. However, differences remain between European countries, which cannot be easily explained. To generate the best care for colorectal cancer in the whole of Europe and to meet political and public demands for transparency, the European CanCer Organisation (ECCO) initiated an international, multidisciplinary, outcome-based quality improvement program: European Registration of Cancer Care (EURECCA). The goal is to create a multidisciplinary European registration structure for patient, tumor, and treatment characteristics linked to outcome registration. Clinical trials will always play a major role in improving rectal cancer treatment. To further improve outcomes and diminish variation, EURECCA will establish the basis for a strong, multidisciplinary, international audit structure that can be used as a template for similar projects worldwide

Abdominal Wound Dehiscence in Adults: Development and Validation of a Risk Model

Background: Several studies have been performed to identify risk factors for abdominal wound dehiscence. No risk model had yet been developed for the general surgical population. The objective of the present study was to identify independent risk factors for abdominal wound dehiscence and to develop a risk model to recognize high-risk patients. Identification of high-risk patients offers opportunities for intervention strategies. Methods: Medical registers from January 1985 to December 2005 were searched. Patients who had primarily undergone appendectomies or nonsurgical (e.g., urological) operations were excluded. Each patient with abdominal wound dehiscence was matched with three controls by systematic random sampling. Putative relevant patient-related, operation-related, and postoperative variables were evaluated in univariate analysis and subsequently entered in multivariate stepwise logistic regression models to delineate major independent predictors of abdominal wound dehiscence. A risk model was developed, which was validated in a population of patients who had undergone operation between January and December 2006. Results: A total of 363 cases and 1,089 controls were analyzed. Major independent risk factors were age, gender, chronic pulmonary disease, ascites, jaundice, anemia, emergency surgery, type of surgery, postoperative coughing, and wound infection. In the validation population, risk scores were significantly higher (P < 0.001) for patients with abdominal wound dehiscence (n = 19) compared to those without (n = 677). Resulting scores ranged from 0 to 8.5, and the risk for abdominal wound dehiscence over this range increased exponentially from 0.02% to 70.1%. Conclusions: The validated risk model shows high predictive value for abdominal wound dehiscence and may help to identify patients at increased risk

Refinement-Based Verification of the FreeRTOS Scheduler in VCC

We describe our experience with verifying the scheduler-related functionality of FreeRTOS, a popular open-source embedded real-time operating system. We propose a methodology for carrying out refinement-based proofs of functional correctness of abstract data types in the popular code-level verifier VCC. We then apply this methodology to carry out a full machine-checked proof of the functional correctness of the FreeRTOS scheduler. We describe the bugs found during this exercise, the fixes made, and the effort involved

The Chromatin Remodeler SPLAYED Regulates Specific Stress Signaling Pathways

Organisms are continuously exposed to a myriad of environmental stresses. Central to an organism's survival is the ability to mount a robust transcriptional response to the imposed stress. An emerging mechanism of transcriptional control involves dynamic changes in chromatin structure. Alterations in chromatin structure are brought about by a number of different mechanisms, including chromatin modifications, which covalently modify histone proteins; incorporation of histone variants; and chromatin remodeling, which utilizes ATP hydrolysis to alter histone-DNA contacts. While considerable insight into the mechanisms of chromatin remodeling has been gained, the biological role of chromatin remodeling complexes beyond their function as regulators of cellular differentiation and development has remained poorly understood. Here, we provide genetic, biochemical, and biological evidence for the critical role of chromatin remodeling in mediating plant defense against specific biotic stresses. We found that the Arabidopsis SWI/SNF class chromatin remodeling ATPase SPLAYED (SYD) is required for the expression of selected genes downstream of the jasmonate (JA) and ethylene (ET) signaling pathways. SYD is also directly recruited to the promoters of several of these genes. Furthermore, we show that SYD is required for resistance against the necrotrophic pathogen Botrytis cinerea but not the biotrophic pathogen Pseudomonas syringae. These findings demonstrate not only that chromatin remodeling is required for selective pathogen resistance, but also that chromatin remodelers such as SYD can regulate specific pathways within biotic stress signaling networks

Properties of Streptomyces sp. endo--xylanases in relation to their applicability in kraft pulp bleaching

info:eu-repo/semantics/publishe