A Methodology for Evaluating Artifacts Produced by a Formal Verification Process

The goal of this study is to produce a methodology for evaluating the claims and arguments employed in, and the evidence produced by formal verification activities. To illustrate the process, we conduct a full assessment of a representative case study for the Enabling Technology Development and Demonstration (ETDD) program. We assess the model checking and satisfiabilty solving techniques as applied to a suite of abstract models of fault tolerant algorithms which were selected to be deployed in Orion, namely the TTEthernet startup services specified and verified in the Symbolic Analysis Laboratory (SAL) by TTTech. To this end, we introduce the Modeling and Verification Evaluation Score (MVES), a metric that is intended to estimate the amount of trust that can be placed on the evidence that is obtained. The results of the evaluation process and the MVES can then be used by non-experts and evaluators in assessing the credibility of the verification results

Study and implementation of urogenital schistosomiasis elimination in Zanzibar (Unguja and Pemba islands) using an integrated multidisciplinary approach

ABSTRACT: BACKGROUND: Schistosomiasis is a parasitic infection that continues to be a major public health problem in many developing countries being responsible for an estimated burden of at least 1.4 million disability-adjusted life years (DALYs) in Africa alone. However, morbidity due to schistosomiasis has been greatly reduced in some parts of the world, including Zanzibar. The Zanzibar government is now committed to eliminate urogenital schistosomiasis. Over the next 3--5 years, the whole at-risk population will be administered praziquantel (40 mg/kg) biannually. Additionally, snail control and behaviour change interventions will be implemented in selected communities and the impact measured in a randomized intervention trial. METHODS: In this 5-year research study, on both Unguja and Pemba islands, urogenital schistosomiasis will be assessed in 45 communities with urine filtration and reagent strips in 4,500 schoolchildren aged 9--12 years annually, and in 4,500 first-year schoolchildren and 2,250 adults in years 1 and 5. Additionally, from first-year schoolchildren, a finger-prick blood sample will be collected and examined for Schistosoma haematobium infection biomarkers. Changes in prevalence and infection intensity will be assessed annually. Among the 45 communities, 15 were randomized for biannual snail control with niclosamide, in concordance with preventive chemotherapy campaigns. The reduction of Bulinus globosus snail populations and S. haematobium-infected snails will be investigated. In 15 other communities, interventions triggering behaviour change have been designed and will be implemented in collaboration with the community. A change in knowledge, attitudes and practices will be assessed annually through focus group discussions and in-depth interviews with schoolchildren, teachers, parents and community leaders. In all 45 communities, changes in the health system, water and sanitation infrastructure will be annually tracked by standardized questionnaire-interviews with community leaders. Additional issues potentially impacting on study outcomes and all incurring costs will be monitored and recorded. DISCUSSION: Elimination of schistosomiasis has become a priority on the agenda of the Zanzibar government and the international community. Our study will contribute to identifying what, in addition to preventive chemotherapy, needs to be done to prevent, control, and ultimately eliminate schistosomiasis, and to draw lessons for current and future schistosomiasis elimination programmes in Africa and elsewhere.Trial registrationISRCTN4883768

Intersectional effects of racial and gender discrimination on cardiovascular health vary among black and white women and men in the CARDIA study

Testing hypotheses from the emerging Identity Pathology (IP) framework, we assessed race-gender differences in the effects of reporting experiences of racial and gender discrimination simultaneously compared with racial or gender discrimination alone, or no discrimination, on future cardiovascular health (CVH). Data were from a sample of 3758 black or white adults in CARDIA, a community-based cohort recruited in Birmingham, AL; Chicago, IL; Minneapolis, MN, and Oakland, CA in 1985-6 (year 0). Racial and gender discrimination were assessed using the Experiences of Discrimination scale. CVH was evaluated using a 12-point composite outcome modified from the Life\u27s Simple 7, with higher scores indicating better health. Multivariable linear regressions were used to evaluate the associations between different perceptions of discrimination and CVH scores two decades later by race and gender simultaneously. Reporting racial and gender discrimination in \u3e /=2 settings were 48% of black women, 42% of black men, 10% of white women, and 5% of white men. Year 30 CVH scores (mean, SD) were 7.9(1.4), 8.1(1.6), 8.8(1.6), and 8.7(1.3), respectively. Compared with those of their race-gender groups reporting no discrimination, white women reporting only gender-based discrimination saw an adjusted score difference of +0.3 (95% CI: 0.0,0.6), whereas white men reporting only racial discrimination had on average a 0.4 (95% CI: 0.1,0.8) higher score, and scores among white men reporting both racial and gender discrimination were on average 0.6 (95% CI: 1.1,-0.1) lower than those of their group reporting no discrimination. Consistent with predictions of the IP model, the associations of reported racial and gender discrimination with future CVH were different for different racially-defined gender groups. More research is needed to understand why reported racial and gender discrimination might better predict deterioration in CVH for whites than blacks, and what additional factors associated with gender and race contribute variability to CVH among these groups

Decade-long trends in the timeliness of receipt of a primary percutaneous coronary intervention

OBJECTIVES: The purpose of this study was to examine decade-long trends (2001-2011) in, and factors associated with, door-to-balloon time within 90 minutes of hospital presentation among patients hospitalized with ST-segment elevation myocardial infarction (STEMI) who received a primary percutaneous coronary intervention (PCI). METHODS: Residents of central Massachusetts hospitalized with STEMI who received a primary PCI at two major PCI-capable medical centers in central Massachusetts on a biennial basis between 2001 and 2011 comprised the study population (n=629). Multivariable regression analyses were used to examine factors associated with failing to receive a primary PCI within 90 minutes after emergency department (ED) arrival. RESULTS: The average age of this patient population was 61.9 years; 30.5% were women, and 91.7% were White. During the years under study, 50.9% of patients received a primary PCI within 90 minutes of ED arrival; this proportion increased from 2001/2003 (17.2%) to 2009/2011 (70.5%) (P \u3c 0.001). Having previously undergone coronary artery bypass graft surgery, arriving at the ED by car/walk-in and during off-hours were significantly associated with a higher risk of failing to receive a primary PCI within 90 minutes of ED arrival. CONCLUSION: The likelihood of receiving a timely primary PCI in residents of central Massachusetts hospitalized with STEMI at the major teaching/community medical centers increased dramatically during the years under study. Several groups were identified for purposes of heightened surveillance and intervention efforts to reduce the likelihood of failing to receive a timely primary PCI among patients acutely diagnosed with STEMI

Universality of the Gunn effect: self-sustained oscillations mediated by solitary waves

The Gunn effect consists of time-periodic oscillations of the current flowing through an external purely resistive circuit mediated by solitary wave dynamics of the electric field on an attached appropriate semiconductor. By means of a new asymptotic analysis, it is argued that Gunn-like behavior occurs in specific classes of model equations. As an illustration, an example related to the constrained Cahn-Allen equation is analyzed.Comment: 4 pages,3 Post-Script figure

Cognitive Status, Initiation of Lifestyle Changes and Medication Adherence after Acute Coronary Syndrome: TRACE-CORE (Transitions, Risks, and Actions in Coronary Events- Center for Outcomes Research and Education)

Background: Lifestyle changes and medication adherence are often recommended to patients after acute coronary syndrome (ACS) as secondary prevention strategies. However, the impact of cognitive impairment (CI) on these secondary prevention strategies following ACS has not been examined. Methods: Cognitive status of 1374 patients with ACS from six hospitals in Massachusetts and Georgia enrolled in the ongoing TRACE-CORE (Transitions, Risks, and Actions in Coronary Events- Center for Outcomes Research and Education) study was assessed during hospitalization using the 41-point Telephone Interview for Cognitive Status (TICS). Information on recommendation and initiation of changes to diet, exercise, tobacco and alcohol use, stress, and cardiac rehabilitation attendance was collected through self-report one month after discharge. Medication adherence was assessed using the 8-item Morisky Scale. Among patients who reported receiving a recommendation for a lifestyle change, we modeled associations between CI and initiation of lifestyle changes and medication adherence, adjusting for demographics via logistic regression. Results: Mean age of participants was 63.0±11.1 years, 67% were male and 79% white; 526 (38.3%) screened positive for CI (TICS score ≤30) during hospitalization. Screening positive for CI was associated with being older, male, non-white, and less educated. Patients with CI more frequently received a recommendation to reduce alcohol use (25% vs. 16% of drinkers, p=.003) but were referred less often to a cardiac rehabilitation program (45% vs. 61%, p=.01). Among patients referred to cardiac rehabilitation (n=743), those with CI at baseline were less likely to report rehabilitation attendance at 1-month (OR= 0.70, 95%CI 0.50-0.97) compared to patients with normal cognitive function. Initiation of other lifestyle changes and medication adherence did not differ by cognitive status. Conclusions: CI is common among patients hospitalized for ACS and is associated with recommendation and initiation of certain lifestyle changes, making it an important factor to consider during the peri-discharge period

Decade-Long Trends in 30-Day Rehospitalization Rates After Acute Myocardial Infarction

BACKGROUND: There are limited data available describing relatively contemporary trends in 30-day rehospitalizations among patients who survive hospitalization after an acute myocardial infarction (AMI) in the community setting. We examined decade-long (2001-2011) trends in, and factors associated with, 30-day rehospitalizations in patients discharged from 3 central Massachusetts hospitals after AMI. METHODS AND RESULTS: Residents of the Worcester, MA, metropolitan area discharged after AMI from 3 central Massachusetts hospitals on a biennial basis between 2001 and 2011 comprised the study population (N=4810). Logistic regression analyses were used to examine the association between selected factors and 30-day rehospitalizations. The average age of this population was 69 years, 42% were women, and 92% were white. During the years under study, 18.5% of patients were rehospitalized within 30 days after hospital discharge. Crude 30-day rehospitalization rates decreased from 20.5% in 2001-2003 to 15.8% in 2009-2011. After adjusting for several patient characteristics, there was a reduced odds of being rehospitalized in 2009-2011 (odds ratio 0.74, 95% CI 0.61-0.91) compared with 2001-2003; this trend was slightly attenuated after further adjustment for hospital treatment practices. Female sex, having previously diagnosed heart failure and chronic kidney disease, and the development of in-hospital cardiogenic shock and heart failure were associated with an increased odds of being rehospitalized. CONCLUSIONS: While the likelihood of subsequent short-term rehospitalizations remained frequent, we observed an encouraging decline during the most recent years under study. Several high-risk groups were identified for purposes of heightened surveillance and intervention efforts to reduce the likelihood of being readmitted

Patterns of practice of regional nodal irradiation in breast cancer: results of the European Organization for Research and Treatment of Cancer (EORTC) NOdal Radiotherapy (NORA) survey†

Predicting breast cancer outcome based on SLN node status without ALND is currently an area of uncertainty in SLN+ patients. These uncertainties influence the decision-making of adjuvant nodal irradiation. The NORA Survey was designed to examine the patterns of RNI practice in Europe to provide a basis for designing future trials in areas of equipoise in clinical decision-making concerning RN

Cluster Transformation Coefficients for Structure and Dynamics Calculations in n-Particle Systems: Atoms, Nuclei, and Quarks

The structure and dynamics of an n-particle system are described with coupled nonlinear Heisenberg's commutator equations where the nonlinear terms are generated by the two-body interaction that excites the reference vacuum via particle-particle and particle-hole excitations. Nonperturbative solutions of the system are obtained with the use of dynamic linearization approximation and cluster transformation coefficients. The dynamic linearization approximation converts the commutator chain into an eigenvalue problem. The cluster coefficients factorize the matrix elements of the (n)-particles or particle-hole systems in terms of the matrix elements of the (n-1)-systems coupled to a particle-particle, particle-hole, and hole-hole boson. Group properties of the particle-particle, particle-hole, and hole-hole permutation groups simplify the calculation of these coefficients. The particle-particle vacuum-excitations generate superconductive diagrams in the dynamics of 3-quarks systems. Applications of the model to fermionic and bosonic systems are discussed.Comment: 13 pages, 5 figures, Wigner Proceedings for Conference Wigner Centenial Pecs, July 8-12, 200

Dynamics of Electric Field Domains and Oscillations of the Photocurrent in a Simple Superlattice Model

A discrete model is introduced to account for the time-periodic oscillations of the photocurrent in a superlattice observed by Kwok et al, in an undoped 40 period AlAs/GaAs superlattice. Basic ingredients are an effective negative differential resistance due to the sequential resonant tunneling of the photoexcited carriers through the potential barriers, and a rate equation for the holes that incorporates photogeneration and recombination. The photoexciting laser acts as a damping factor ending the oscillations when its power is large enough. The model explains: (i) the known oscillatory static I-V characteristic curve through the formation of a domain wall connecting high and low electric field domains, and (ii) the photocurrent and photoluminescence time-dependent oscillations after the domain wall is formed. In our model, they arise from the combined motion of the wall and the shift of the values of the electric field at the domains. Up to a certain value of the photoexcitation, the non-uniform field profile with two domains turns out to be metastable: after the photocurrent oscillations have ceased, the field profile slowly relaxes toward the uniform stationary solution (which is reached on a much longer time scale). Multiple stability of stationary states and hysteresis are also found. An interpretation of the oscillations in the photoluminescence spectrum is also given.Comment: 34 pages, REVTeX 3.0, 10 figures upon request, MA/UC3M/07/9