Mining State-Based Models from Proof Corpora

Interactive theorem provers have been used extensively to reason about various software/hardware systems and mathematical theorems. The key challenge when using an interactive prover is finding a suitable sequence of proof steps that will lead to a successful proof requires a significant amount of human intervention. This paper presents an automated technique that takes as input examples of successful proofs and infers an Extended Finite State Machine as output. This can in turn be used to generate proofs of new conjectures. Our preliminary experiments show that the inferred models are generally accurate (contain few false-positive sequences) and that representing existing proofs in such a way can be very useful when guiding new ones.Comment: To Appear at Conferences on Intelligent Computer Mathematics 201

Home-based pre-exposure prophylaxis (PrEP) services for gay and bisexual men: An opportunity to address barriers to PrEP uptake and persistence

Gay, bisexual, and other men who have sex with men (GBM) are disproportionately affected by the HIV epidemic. Despite the promise of pre-exposure prophylaxis (PrEP) in reducing HIV transmission risk, barriers for uptake and persistence exist. We sought to identify whether GBM in a nationwide cohort who have not yet initiated PrEP (n = 906) would prefer to get PrEP-related care from a primary care provider (PCP) compared to a specialist clinic or provider. We then sought to identify their level of interest and factors associated with preference for using home-based PrEP services (i.e., HB-PrEP), defined to participants as conducting HIV/STI self-testing from home with PrEP prescription mailing after an initial inperson clinic visit. We examined the associations of demographics, sexual HIV transmission risk, concern about frequent medical checkups associated with PrEP, health care access, and PrEP intentions with preferences for healthcare provider type and HB-PrEP. Concern about frequent medical checkups were associated with preferring a PCP for PrEP-related care, but men who perceived a barrier to bringing up the topic of PrEP with a doctor preferred a specialist clinic or provider more than a PCP. HB-PrEP was more appealing for younger men and those engaged in sexual HIV transmission risk, suggesting HB-PrEP could help reach GBM most vulnerable to HIV and in need of PrEP. HB-PrEP expansion has potential to increase PrEP uptake and persistence among GBM, particularly for men with barriers to clinic-based care and higher intentions to initiate PrEP. Clinical guidelines regarding HB-PrEP are needed to expand its use

Exploring Design Alternatives for RAMP Transactions through Statistical Model Checking

In this paper we explore and extend the design space of the recent RAMP (Read Atomic Multi-Partition) transaction system for large-scale partitioned data stores. Arriving at a mature distributed system design through implementation and experimental validation is a labor-intensive task, so that only a limited number of design alternatives can be explored in practice. The developers of RAMP did implement and validate three design alternatives for RAMP, and sketched three additional designs. This work addresses two questions: (1) How can the design space of a distributed transaction system such as RAMP be explored with modest effort, so that substantial knowledge about design alternatives can be gained before designs are implemented? and (2) How realistic and informative are the results of such design explorations? We answer the first question by: (i) formally modeling eight RAMP-like designs (five by the RAMP developers and three of our own) in Maude as probabilistic rewrite theories, and (ii) using statistical model checking of those models to analyze key performance metrics such as throughput, average latency, and degrees of strong consistency and read atomicity. We answer the second question by showing that our quantitative analyses: (i) are consistent with the experimental results obtained by the RAMP developers for their implemented designs; (ii) confirm the conjectures made by the RAMP developers for their other three unimplemented designs; and (iii) uncover some promising new designs that seem attractive for some applications.Ope

A Systematic Review of Online Sex Addiction and Clinical Treatments Using CONSORT Evaluation

Researchers have suggested that the advances of the Internet over the past two decades have gradually eliminated traditional offline methods of obtaining sexual material. Additionally, research on cybersex and/or online sex addictions has increased alongside the development of online technology. The present study extended the findings from Griffiths’ (2012) systematic empirical review of online sex addiction by additionally investigating empirical studies that implemented and/or documented clinical treatments for online sex addiction in adults. A total of nine studies were identified and then each underwent a CONSORT evaluation. The main findings of the present review provide some evidence to suggest that some treatments (both psychological and/or pharmacological) provide positive outcomes among those experiencing difficulties with online sex addiction. Similar to Griffiths’ original review, this study recommends that further research is warranted to establish the efficacy of empirically driven treatments for online sex addiction

Semi-Automated Design Space Exploration for Formal Modelling

Refinement based formal methods allow the modelling of systems through incremental steps via abstraction. Discovering the right levels of abstraction, formulating correct and meaningful invariants, and analysing faulty models are some of the challenges faced when using this technique. We propose Design Space Exploration that aims to assist a designer by automatically providing high-level modelling guidance

Morbidity, life style and psychosocial situation in cancer survivors aged 60-69 years: results from The Nord-Trøndelag Health Study (The HUNT-II Study)

<p>Abstract</p> <p>Background</p> <p>Due to considerable health status differences in the elderly population, research limited to narrow age-spans might be an advantage. In this population-based controlled study we compare short-term (<5 years) (STS) and long-term (≥5 years) (LTS) cancer survivors and cancer-free controls aged 60-69 years from two Norwegian health registers; the Health Survey of North-Trøndelag County (HUNT-2 study) and the Cancer Registry of Norway (CRN). We examined possible factors associated with being cancer survivor.</p> <p>Methods</p> <p>Among 9,089 individuals aged 60-69 who participated in HUNT-2, 334 had been diagnosed with invasive primary cancer from 1 month to 42 years before HUNT-2 according to CRN and self-report. An overall random sample of controls without cancer five times larger than the sample of cases (N = 1,670) were drawn from the parent cohort.</p> <p>Results</p> <p>The cancer sample comprised 128 STS and 206 LTS. For most variables no significant differences were observed between LTS and STS. LTS were significantly more women, and cases with gynaecological cancer, with physical impairment and more thyroid diseases compared to STS. When comparing all the survivors with controls, the survivors showed significantly higher rate of pensioning, decreased self-rated health, more physical impairment and thyroid diseases, daily use of medication and psychotropics and higher level of anxiety and Framingham Risk score. Multivariate logistic regression analysis showed that increasing age, being female, physical impairment and thyroid diseases all were significantly associated with being survivor versus controls.</p> <p>Conclusion</p> <p>STS and LTS showed mostly similar situation. Compared to controls, the survivors reported somewhat poorer physical and mental health, but these differences were of doubtful clinical significance.</p

Automatic Analysis of Consistency Properties of Distributed Transaction Systems in Maude

Many transaction systems distribute, partition, and replicate their data for scalability, availability, and fault tolerance. However, observing and maintaining strong consistency of distributed and partially replicated data leads to high transaction latencies. Since different applications require different consistency guarantees, there is a plethora of consistency properties---from weak ones such as read atomicity through various forms of snapshot isolation to stronger serializability properties---and distributed transaction systems (DTSs) guaranteeing such properties. This paper presents a general framework for formally specifying a DTS in Maude, and formalizes in Maude nine common consistency properties for DTSs so defined. Furthermore, we provide a fully automated method for analyzing whether the DTS satisfies the desired property for all initial states up to given bounds on system parameters. This is based on automatically recording relevant history during a Maude run and defining the consistency properties on such histories. To the best of our knowledge, this is the first time that model checking of all these properties in a unified, systematic manner is investigated. We have implemented a tool that automates our method, and use it to model check state-of-the-art DTSs such as P-Store, RAMP, Walter, Jessy, and ROLA.Ope

Seroincidence of SARS-CoV-2 infection prior to and during the rollout of vaccines in a community-based prospective cohort of U.S. adults

This study used repeat serologic testing to estimate infection rates and risk factors in two overlapping cohorts of SARS-CoV-2 N protein seronegative U.S. adults. One mostly unvaccinated sub-cohort was tracked from April 2020 to March 2021 (pre-vaccine/wild-type era, n = 3421), and the other, mostly vaccinated cohort, from March 2021 to June 2022 (vaccine/variant era, n = 2735). Vaccine uptake was 0.53% and 91.3% in the pre-vaccine and vaccine/variant cohorts, respectively. Corresponding seroconversion rates were 9.6 and 25.7 per 100 person-years. In both cohorts, sociodemographic and epidemiologic risk factors for infection were similar, though new risk factors emerged in the vaccine/variant era, such as having a child in the household. Despite higher incidence rates in the vaccine/variant cohort, vaccine boosters, masking, and social distancing were associated with substantially reduced infection risk, even through major variant surges