Parallelizing Deadlock Resolution in Symbolic Synthesis of Distributed Programs

Previous work has shown that there are two major complexity barriers in the synthesis of fault-tolerant distributed programs: (1) generation of fault-span, the set of states reachable in the presence of faults, and (2) resolving deadlock states, from where the program has no outgoing transitions. Of these, the former closely resembles with model checking and, hence, techniques for efficient verification are directly applicable to it. Hence, we focus on expediting the latter with the use of multi-core technology. We present two approaches for parallelization by considering different design choices. The first approach is based on the computation of equivalence classes of program transitions (called group computation) that are needed due to the issue of distribution (i.e., inability of processes to atomically read and write all program variables). We show that in most cases the speedup of this approach is close to the ideal speedup and in some cases it is superlinear. The second approach uses traditional technique of partitioning deadlock states among multiple threads. However, our experiments show that the speedup for this approach is small. Consequently, our analysis demonstrates that a simple approach of parallelizing the group computation is likely to be the effective method for using multi-core computing in the context of deadlock resolution

Constraint Based Automated Synthesis of Nonmasking and Stabilizing Fault-Tolerance

We focus on constraint-based automated addition of nonmasking and stabilizing fault-tolerance to hi-erarchical programs. We specify legitimate states of the program in terms of constraints that should be satisfied in those states. To deal with faults that may violate these constraints, we add recovery ac-tions while ensuring interference freedom among the recovery actions added for satisfying different con-straints. Since the constraint-based manual design of fault-tolerance is well-known to be applicable in the manual design of nonmasking fault-tolerance, we expect our approach to have a significant benefit in automation of fault-tolerant programs. We illus-trate our algorithms with three case studies: stabi-lizing mutual exclusion, stabilizing diffusing compu-tation, and a data dissemination problem in sensor networks. With experimental results, we show that the complexity of synthesis is reasonable and that it can be reduced using the structure of the hierarchical systems. To our knowledge, this is the first instance where automated synthesis has been successfully used in synthesizing programs that are correct under fair-ness assumptions. Moreover, in two of the case studies considered in this paper, the structure of the recovery paths is too complex to permit exist-ing heuristic based approaches for adding recovery.

The Process of Translating and Culturally Adapting a Digital Elder Abuse Intervention

Elder Abuse is a national public health problem affecting one in ten older adults. It is estimated that only 4% of cases are reported to authorities. Latino populations that reside in the U.S. are less likely to report abuse, and language barriers may limit access to resources and prevent seeking help. There is a need for tools and services to not only be translated but culturally adapted to ensure the integrity and comprehension of the translated product. We conducted an extensive literature review that informed our multi-step language translation and cross-cultural adaptation of the VOICES digital health elder abuse intervention from English to Spanish. This process involved a team of independent translators for an iterative, step-by-step approach that included synthesis and review at each step of the process. Translations were individually rated by the review team based on a 7-point Likert scale. The review team found the translations appropriate and highly satisfactory. Comparison of separate versions of translated items highlighted key linguistic variations and issues that informed the team when producing the final translated product. Challenges found during the translation process were categorized as a posteriori. Examples are included. Following a multi-step, iterative framework for the translation and cultural adaptation provided a highly accurate product. Involving multiple translators from varying backgrounds reduced the risk for translation bias and flagged cultural nuances that allowed the research team to identify areas that needed more attention and care. The product will be further culturally adapted with the help of the community via cognitive interviews with Spanish-speaking individuals relevant to the intervention's intended target population before following up with a study to compare with the original findings of the intervention's parent study

Modeling human health behavior with a new index that measures connectivity

Objective: Health behavior is an important determinant of health. Adherence to medication and abstinence from harmful substances are two critical health behaviors. Although conceptually related, both are assessed using disparate measures. The goal of this study was to develop and test a new index, gamma, which models health behavior by quantifying the connectedness of discrete incidents of health behavior. Study design and setting: We derive gamma from first principles and use it to reanalyze data from a published trial of treatment for alcohol use disorders. We model a primary endpoint, changes in binge drinking, using gamma and a traditional measure: change in number of monthly binges. The original trial was conducted in an urban hospital emergency department in the U.S. Results: Incorporating gamma into the model provided additional insights into the relationship between the intervention and long-term changes in drinking. Conclusion: Gamma provides an additional tool to model the effects of interventions on outcomes in trials of substance use interventions or medication adherence. Gamma measures the pattern of behavior and may increase the explanatory power of models assessing differences between various treatments. The gamma index offers the possibility of novel real-time interventions to promote healthy behaviors

Comparing a Multimedia Digital Informed Consent Tool With Traditional Paper-Based Methods: Randomized Controlled Trial

BackgroundThe traditional informed consent (IC) process rarely emphasizes research participants’ comprehension of medical information, leaving them vulnerable to unknown risks and consequences associated with procedures or studies. ObjectiveThis paper explores how we evaluated the feasibility of a digital health tool called Virtual Multimedia Interactive Informed Consent (VIC) for advancing the IC process and compared the results with traditional paper-based methods of IC. MethodsUsing digital health and web-based coaching, we developed the VIC tool that uses multimedia and other digital features to improve the current IC process. The tool was developed on the basis of the user-centered design process and Mayer’s cognitive theory of multimedia learning. This study is a randomized controlled trial that compares the feasibility of VIC with standard paper consent to understand the impact of interactive digital consent. Participants were recruited from the Winchester Chest Clinic at Yale New Haven Hospital in New Haven, Connecticut, and healthy individuals were recruited from the community using fliers. In this coordinator-assisted trial, participants were randomized to complete the IC process using VIC on the iPad or with traditional paper consent. The study was conducted at the Winchester Chest Clinic, and the outcomes were self-assessed through coordinator-administered questionnaires. ResultsA total of 50 participants were recruited in the study (VIC, n=25; paper, n=25). The participants in both groups had high comprehension. VIC participants reported higher satisfaction, higher perceived ease of use, higher ability to complete the consent independently, and shorter perceived time to complete the consent process. ConclusionsThe use of dynamic, interactive audiovisual elements in VIC may improve participants’ satisfaction and facilitate the IC process. We believe that using VIC in an ongoing, real-world study rather than a hypothetical study improved the reliability of our findings, which demonstrates VIC’s potential to improve research participants’ comprehension and the overall process of IC. Trial RegistrationClinicalTrials.gov NCT02537886; https://clinicaltrials.gov/ct2/show/NCT0253788