Prediction and measurement of radiation damage to CMOS devices on board spacecraft

The CMOS Radiation Effects Measurement (CREM) experiment is presently being flown on the Explorer-55. The purpose of the experiment is to evaluate device performance in the actual space radiation environment and to correlate the respective measurements to on-the-ground laboratory irradiation results. The experiment contains an assembly of C-MOS and P-MOS devices shielded in front by flat slabs of aluminum and by a practically infinite shield in the back. Predictions of radiation damage to C-MOS devices are based on standard environment models and computational techniques. A comparison of the shifts in CMOS threshold potentials, that is, those measured in space to those obtained from the on-the-ground simulation experiment with Co-60, indicates that the measured space damage is smaller than predicted by about a factor of 2-3 for thin shields, but agrees well with predictions for thicker shields

An open extensible tool environment for Event-B

Abstract. We consider modelling indispensable for the development of complex systems. Modelling must be carried out in a formal notation to reason and make meaningful conjectures about a model. But formal modelling of complex systems is a difficult task. Even when theorem provers improve further and get more powerful, modelling will remain difficult. The reason for this that modelling is an exploratory activity that requires ingenuity in order to arrive at a meaningful model. We are aware that automated theorem provers can discharge most of the onerous trivial proof obligations that appear when modelling systems. In this article we present a modelling tool that seamlessly integrates modelling and proving similar to what is offered today in modern integrated development environments for programming. The tool is extensible and configurable so that it can be adapted more easily to different application domains and development methods.

Disruption of termite gut-microbiota and its prolonged fitness consequences

Author Posting. © The Author(s), 2011. This is the author's version of the work. It is posted here by permission of American Society for Microbiology for personal use, not for redistribution. The definitive version was published in Applied and Environmental Microbiology 77 (2011): 4303-4312, doi:10.1128/AEM.01886-10.The disruption of host-symbiont interactions through the use of antibiotics can help elucidate microbial functions that go beyond short-term nutritional value. Termite gut symbionts have been studied extensively, but little is known about their impact on the termite’s reproductive output. Here we describe the effect that the antibiotic rifampin has not only on the gut microbial diversity, but also on the longevity, fecundity, and weight of two termite species - Zootermopsis angusticollis and Reticulitermes flavipes. We report three key findings: (i) the antibiotic rifampin, when fed to primary reproductives during the incipient stages of colony foundation, causes a permanent reduction in the diversity of gut bacteria, and a transitory effect on the density of the protozoan community, (ii) rifampin treatment reduces oviposition rates of queens, translating into delayed colony growth and ultimately reduced colony fitness and (iii) the initial dosages of rifampin on reproduction and colony fitness had severe longterm fitness effects on Z. angusticollis survivorship and colony size. Taken together, our findings demonstrate that the antibiotic-induced perturbation of the microbial community associates with prolonged reductions in longevity and fecundity. A causal relationship between these changes in the gut microbial population structures and fitness is suggested by the acquisition of opportunistic pathogens and incompetence of the termites to restore a pre-treatment, native microbiota. Our results indicate that antibiotic treatment significantly alters the termite’s microbiota, reproduction, colony establishment and ultimately, colony growth and development. We discuss the implications for antimicrobials as a new application to the control of termite pest species.This research was funded by the Louis Stokes Minority Program which supported Jessica Dumas, NSF CAREER award DEB 0447316 to Rosengaus RB, and NSF IOS-0852344 and NAI NNA04CC04A to Bordenstein SR

Single-machine scheduling with stepwise tardiness costs and release times

We study a scheduling problem that belongs to the yard operations component of the railroad planning problems, namely the hump sequencing problem. The scheduling problem is characterized as a single-machine problem with stepwise tardiness cost objectives. This is a new scheduling criterion which is also relevant in the context of traditional machine scheduling problems. We produce complexity results that characterize some cases of the problem as pseudo-polynomially solvable. For the difficult-to-solve cases of the problem, we develop mathematical programming formulations, and propose heuristic algorithms. We test the formulations and heuristic algorithms on randomly generated single-machine scheduling problems and real-life datasets for the hump sequencing problem. Our experiments show promising results for both sets of problems

‘In the dark’: Voices of parents in marginalised stepfamilies: perceptions and experiences of their parenting support needs

The fastest growing family type in the UK is the stepfamily with social parenting an increasingly normal practice. Parenting policy and practice, which has increased exponentially over the last two decades, has historically been modelled on the biological nuclear family model with marginalised families the main recipients. The possibility that parents in marginalised stepfamilies might have separate and discrete parenting support needs to biological parents seems to be overlooked in policy, practice and research. Rather, the historical legacy of deficit, dysfunction and a ‘whiff’ of poor parenting in marginalised stepfamilies lingers on. The focus of the research was to determine marginalised parents’ perceptions and experiences of parenting in their stepfamily and their parenting support needs. Thematic analysis of the data revealed accounts that were interwoven throughout with strong moral undertones which seemed to categorise their lives. The parenting issues were different and more complex than those they had encountered before. The parents adopted biological family identities, but these didn’t fit with their social roles and often rendered them powerless in their relationships with stepchildren. This appeared to have a cumulative effect which impacted on the already fragile couple relationship. Despite the parents easy articulation of the parenting issues there was a contrasting unease and ambivalence in discussing parenting support needs. Parenting support seemed to be an irrelevance that could be disregarded. Ultimately the moral significance of the parents marginalised class positions appeared to be central to their lives, which has important implications for policy and practice

Isabelle/DOF: Design and Implementation

This is the author accepted manuscript. The final version is available from Springer Verlag via the DOI in this record17th International Conference, SEFM 2019 Oslo, Norway, September 18–20, 2019DOF is a novel framework for defining ontologies and enforcing them during document development and evolution. A major goal of DOF is the integrated development of formal certification documents (e. g., for Common Criteria or CENELEC 50128) that require consistency across both formal and informal arguments. To support a consistent development of formal and informal parts of a document, we provide Isabelle/DOF, an implementation of DOF on top of the formal methods framework Isabelle/HOL. A particular emphasis is put on a deep integration into Isabelleâs IDE, which allows for smooth ontology development as well as immediate ontological feedback during the editing of a document. In this paper, we give an in-depth presentation of the design concepts of DOFâs Ontology Definition Language (ODL) and key aspects of the technology of its implementation. Isabelle/DOF is the first ontology language supporting machine-checked links between the formal and informal parts in an LCF-style interactive theorem proving environment. Sufficiently annotated, large documents can easily be developed collabo- ratively, while ensuring their consistency, and the impact of changes (in the formal and the semi-formal content) is tracked automatically.IRT SystemX, Paris-Saclay, Franc

Effects of Relaxation and Deep-Breathing on High School Students: ACT Prep

The purpose of this study was to relieve test anxiety in high school juniors preparing to take the ACT: a high-stakes, college admissions, standardized test. Participants included 81 eleventh grade students (25 males, 56 females) from a Midwestern public high school. Results demonstrated that relaxation training in the experimental group significantly lowered student’s perceptions of test anxiety from pre-test to post-test. Further research regarding systematic deep breathing and relaxation techniques is needed

Effects of Relaxation and Deep-Breathing on High School Students: ACT Prep

The purpose of this study was to relieve test anxiety in high school juniors preparing to take the ACT: a high-stakes, college admissions, standardized test. Participants included 81 eleventh grade students (25 males, 56 females) from a Midwestern public high school. Results demonstrated that relaxation training in the experimental group significantly lowered student’s perceptions of test anxiety from pre-test to post-test. Further research regarding systematic deep breathing and relaxation techniques is needed