Many-core compiler fuzzing

We address the compiler correctness problem for many-core systems through novel applications of fuzz testing to OpenCL compilers. Focusing on two methods from prior work, random differential testing and testing via equivalence modulo inputs (EMI), we present several strategies for random generation of deterministic, communicating OpenCL kernels, and an injection mechanism that allows EMI testing to be applied to kernels that otherwise exhibit little or no dynamically-dead code. We use these methods to conduct a large, controlled testing campaign with respect to 21 OpenCL (device, compiler) configurations, covering a range of CPU, GPU, accelerator, FPGA and emulator implementations. Our study provides independent validation of claims in prior work related to the effectiveness of random differential testing and EMI testing, proposes novel methods for lifting these techniques to the many-core setting and reveals a significant number of OpenCL compiler bugs in commercial implementations

Environment Behavior Models for Scenario Generation and Testing Automation

In Proceedings of the First International Workshop on Advances in Model-Based Software Testing (A-MOST'05), the 27th International Conference on Software Engineering ICSE’05, May 15-16, 2005, St. Louis, USAThis paper suggests an approach to automatic scenario generation from environment models for testing of real-time reactive systems. The behavior of the system is defined as a set of events (event trace) with two basic relations: precedence and inclusion. The attributed event grammar (AEG) specifies possible event traces and provides a uniform approach for automatically generating, executing, and analyzing test cases. The environment model includes a description of hazardous states in which the system may arrive and makes it possible to gather statistics for system safety assessment. The approach is supported by a generator that creates test cases from the AEG models. We demonstrate the approach with case studies of prototypes for the safety-critical computer-assisted resuscitation algorithm (CARA) software for a casualty intravenous fluid infusion pump and the Paderborn Shuttle System

Zaštitno djelovanje selenija protiv prekomjerne ekspresije apoptotskih gena povezanih s karcinomom u štakora izloženih o-krezolu

Cresols are monomethyl derivatives of phenol frequently used as solvents and intermediates in the production of disinfectants, fragrances, pesticides, dyes, and explosives, which is probably why they are widely distributed in the environment. General population may be exposed to cresols mainly through inhalation of contaminated air. In this study we evaluated the toxicological effects of o-cresol on differential gene expression profile of rat liver and prostate. Experiments were conducted on 80 male rats, 60 of which were exposed to o-cresol (1.5 g kg-1, 5 g kg-1, or 15 g kg-1) through feed for 8 weeks. Three groups of rats were supplemented with 0.1 mg kg-1 selenium (Se, in the form of, sodium selenite) in addition to o-cresol to evaluate its effectiveness against o-cresol toxicity. Control group received neither o-cresol nor Se, while one group received Se alone. Survival was similar between the exposed and control animals. Rats exposed to 15 g kg-1 of o-cresol showed a 16 % loss in body weight by the end of the study, which may have been related to o-cresol making feed unpalatable at this concentration. Liver and prostate tissue samples were collected at the end of the treatment. mRNA analysis revealed that apoptotic genes (CYP3A, COX-2, PPARγ, BAX, BCL2, AKT-1, and PKCα) related to cancer were up-regulated in liver and prostate tissues isolated from groups exposed to 5 g kg-1 and 15 g kg-1 o-cresol in comparison to control. Changes in gene expression profile were prevented when rats were supplemented with Se. The exact mechanisms underlying its protective effect remain to be clarified by future studies.Krezoli su monometilni derivati fenola koji se često rabe kao otapala te kao posrednici u proizvodnji dezinfekcijskih sredstava, mirisa, pesticida, boja i eksploziva. Otuda i njihova rasprostranjenost u okolišu. Opća je populacija izložena krezolima uglavnom putem zraka. U ovome se toksikološkom istraživanju ocijenilo djelovanje o-krezola, jednoga od tri krezolova izomera, na ekspresiju gena u tkivima jetre i prostate mužjaka štakora. Istraživanje je provedeno na 80 mužjaka, od kojih je 60 tijekom osam tjedana bilo izloženo o-krezolu (1,5 g kg-1, 5 g kg-1, odnosno 15 g kg-1) preko krmiva. Tri skupine štakora primale su uz o-krezol nadomjestak selenija u dozi od 0.1 mg kg-1 (Se, u obliku natrijeva selenita) radi ocjene njegove djelotvornosti protiv toksičnosti o-krezola. Kontrolna skupina nije primala ni o-krezol ni Se, dok je jedna skupina primala samo Se. Preživljenje je bilo podjednako u svih skupina životinja. Štakori izloženi najvišoj dozi o-krezola (15 g kg-1) imali su 16 % manju tjelesnu masu od kontrolne skupine na kraju ispitivanja, što može biti povezano s lošim okusom krmiva zbog primjese visoke doze o-krezola. S istekom osmotjednoga izlaganja o-krezolu životinje su eutanazirane te su prikupljeni uzorci tkiva jetre i prostate. Analiza m-RNA pokazala je značajno povišenu ekspresiju apoptotskih gena CYP3A, COX-2, PPARγ, BAX, BCL2, AKT-1 i PKCα, koji su povezani s nastankom karcinoma u skupinama štakora izloženim o-krezolu (5 g kg-1 i 15 g kg-1 u odnosu na kontrolu. Ova je prekomjerna ekspresija poništena u štakora koji su primali selenij. Još nisu jasni mehanizmi iza ovoga zaštitnog djelovanja, na što će odgovoriti buduća istraživanja

The Relationship of Maternal Prepregnancy Body Mass Index and Pregnancy Weight Gain to Neurocognitive Function at Age 10 Years among Children Born Extremely Preterm

OBJECTIVE: To assess the association between maternal prepregnancy body mass index and adequacy of pregnancy weight gain in relation to neurocognitive function in school-aged children born extremely preterm. STUDY DESIGN: Study participants were 535 ten-year-old children enrolled previously in the prospective multicenter Extremely Low Gestational Age Newborns cohort study who were products of singleton pregnancies. Soon after delivery, mothers provided information about prepregnancy weight. Prepregnancy body mass index and adequacy of weight gain were characterized based on this information. Children underwent a neurocognitive evaluation at 10 years of age. RESULTS: Maternal prepregnancy obesity was associated with increased odds of a lower score for Differential Ability Scales-II Verbal IQ, for Developmental Neuropsychological Assessment-II measures of processing speed and visual fine motor control, and for Wechsler Individual Achievement Test-III Spelling. Children born to mothers who gained an excessive amount of weight were at increased odds of a low score on the Oral and Written Language Scales Oral Expression assessment. Conversely, children whose mother did not gain an adequate amount of weight were at increased odds of a lower score on the Oral and Written Language Scales Oral Expression and Wechsler Individual Achievement Test-III Word Reading assessments. CONCLUSION: In this cohort of infants born extremely preterm, maternal obesity was associated with poorer performance on some assessments of neurocognitive function. Our findings are consistent with the observational and experimental literature and suggest that opportunities may exist to mitigate risk through education and behavioral intervention before pregnancy

BHPR research: qualitative1. Complex reasoning determines patients' perception of outcome following foot surgery in rheumatoid arhtritis

Background: Foot surgery is common in patients with RA but research into surgical outcomes is limited and conceptually flawed as current outcome measures lack face validity: to date no one has asked patients what is important to them. This study aimed to determine which factors are important to patients when evaluating the success of foot surgery in RA Methods: Semi structured interviews of RA patients who had undergone foot surgery were conducted and transcribed verbatim. Thematic analysis of interviews was conducted to explore issues that were important to patients. Results: 11 RA patients (9 ♂, mean age 59, dis dur = 22yrs, mean of 3 yrs post op) with mixed experiences of foot surgery were interviewed. Patients interpreted outcome in respect to a multitude of factors, frequently positive change in one aspect contrasted with negative opinions about another. Overall, four major themes emerged. Function: Functional ability & participation in valued activities were very important to patients. Walking ability was a key concern but patients interpreted levels of activity in light of other aspects of their disease, reflecting on change in functional ability more than overall level. Positive feelings of improved mobility were often moderated by negative self perception ("I mean, I still walk like a waddling duck”). Appearance: Appearance was important to almost all patients but perhaps the most complex theme of all. Physical appearance, foot shape, and footwear were closely interlinked, yet patients saw these as distinct separate concepts. Patients need to legitimize these feelings was clear and they frequently entered into a defensive repertoire ("it's not cosmetic surgery; it's something that's more important than that, you know?”). Clinician opinion: Surgeons' post operative evaluation of the procedure was very influential. The impact of this appraisal continued to affect patients' lasting impression irrespective of how the outcome compared to their initial goals ("when he'd done it ... he said that hasn't worked as good as he'd wanted to ... but the pain has gone”). Pain: Whilst pain was important to almost all patients, it appeared to be less important than the other themes. Pain was predominately raised when it influenced other themes, such as function; many still felt the need to legitimize their foot pain in order for health professionals to take it seriously ("in the end I went to my GP because it had happened a few times and I went to an orthopaedic surgeon who was quite dismissive of it, it was like what are you complaining about”). Conclusions: Patients interpret the outcome of foot surgery using a multitude of interrelated factors, particularly functional ability, appearance and surgeons' appraisal of the procedure. While pain was often noted, this appeared less important than other factors in the overall outcome of the surgery. Future research into foot surgery should incorporate the complexity of how patients determine their outcome Disclosure statement: All authors have declared no conflicts of interes