A Formal Executable Semantics of Verilog

This paper describes a formal executable semantics for the Verilog hardware description language. The goal of our formalization is to provide a concise and mathematically rigorous reference augmenting the prose of the official language standard, and ultimately to aid developers of Verilog-based tools; e.g., simulators, test generators, and verification tools. Our semantics applies equally well to both synthesizeable and behavioral designs and is given in a familiar, operational-style within a logic providing important additional benefits above and beyond static formalization. In particular, it is executable and searchable so that one can ask questions about how a, possibly nondeterministic, Verilog program can legally behave under the formalization. The formalization should not be seen as the final word on Verilog, but rather as a starting point and basis for community discussions on the Verilog semantics.CCF-0916893CNS-0720512CCF-0905584CCF-0448501NNL08AA23Cunpublishedis peer reviewe

Efficient Monitoring of Parametric Context Free Patterns

Recent developments in runtime verification and monitoring show that parametric regular and temporal logic specifications can be efficiently monitored against large programs. However, these logics reduce to ordinary finite automata, limiting their expressivity. For example, neither can specify structured properties that refer to the call stack of the program. While context-free grammars (CFGs) are expressive and well-understood, existing techniques of monitoring CFGs generate massive runtime overhead in real-life applications. This paper shows for the first time that monitoring parametric CFGs is practical (on the order of 10% or lower for average cases, several times faster than the state-of-the-art). We present a monitor synthesis algorithm for CFGs based on an LR(1) parsing algorithm, modified with stack cloning to account for good prefix matching. In addition, a logic-independent mechanism is introduced to support partial matching, allowing patterns to be checked against fragments of execution traces

Unskilled labour before the Industrial Revolution

The Industrial Revolution is seen as a major turning point in the management of labour, bringing about employment practices that gave structure and stability to the workforce. This paper provides evidence that employers were using hiring and retention strategies to stabilize the unskilled workforce at least a century before industrialization. We exploit the comprehensive employment records that survive from the rebuilding of St. Paul’s Cathedral in London (1672–1748) to reconstruct and analyse the employment history of over one thousand general building labourers, the benchmark category of unskilled workers for economic historians. We show that St. Paul’s was able to stabilize its workforce by establishing a core group of long-standing workers. Tenure was incentivized with more days of work each month on the site, priority in the queue for retention and rehiring in periods of low labour demand, and the opportunity to earn additional income as watchmen. These strategies reduced turnover and may have allowed the Cathedral to retain the most productive workers, reshaping our understanding of when modern employment practices emerged

Evaluation of Two Malaria Rapid Diagnostic Tests Quality Assurance (mRDT’s QA) Methods in Peripheral Health Facilities, Rural Tanzania.

\ud WHO recommends confirming suspected malaria cases before initiation of treatment. Due to the imited availability of quality microscopy services, this recommendation has been followed with increased use of antigen-detecting malaria rapid diagnostic tests (mRDTs) in many malaria endemic countries. With the increased use of mRDTs, the need for a thorough mRDT quality assurance (RDT QA) method has become more apparent. One of the WHO recommendations for RDT QA is to monitor the tests in field use monthly, by comparing mRDT results to reference microscopy. This study was carried out to monitor mRDT performance in selected health facilities using two quality assurance methods; first based on ference microscopy and second based on detection of parasite DNA by real time quantitative PCR (qPCR) on dried blood spots (DBS); as well as assessing the cost and timeliness of the two QA methods. Blood samples were collected from patients undergoing a rapid test for malaria for two to three consecutive days per month, for five months, in 12 health facilities in Iringa rural and Mufindi districts. The health workers were instructed to label RDT cassettes, blood smear slides, and filter papers for DBS with matching unique ID stickers. A sticker was also placed in the log book where RDT results were recorded. Blood smears (BS) were first read at the district hospital (BS1) and then transported to Bagamoyo for a reference reading at the IHI- Bagamoyo laboratory (BS2). A third BS reader (BS3) was consulted from Muhimbili University of Health and Allied Sciences (MUHAS) in case of discordant results between BS1 and BS2. Molecular analysis involved extraction of parasite DNA from DBS samples using a QIAamp DNA Mini Kit. Sample DNA aliquots were compared against standard solutions with parasite DNA diluted 10-fold to give a parasitemia ranging from 200,000/μL to 20/μL. About 20% of the study DNA aliquots were sent to the CDC laboratory in Atlanta in order to validate qPCR results performed at the Bagamoyo laboratory. Data were entered in Microsoft Access (Microsoft Corporation, 2006) and analyzed in STATA 10 (StataCorp, Texas USA). Because of the known limitations of mRDTs to detect parasitemia below 200 parasites/μL, BS and PCR results greater than or equal to 5 parasites/200 WBC or 200 parasites/μL were considered positive in comparisons with mRDT performance. In the univariate analysis, proportions of positive tests were compared among the three types of tests: mRDT, microscopy and qPCR. Microscopy readings were categorized into 3 groups; BS1, BS2 and /or BS summary which is an average of BS1 and BS2. In case of discordant results between BS1 and BS2, a third reader- BS3 was consulted. Chi-squared test was done to assess differences in proportion of positive tests per district; whereas McNemar’s test was Malaria RDT QA Final Report, March 2012 5 used to assess the difference in test positivity by type of test. Kappa statistic was used to quantify the strength of the agreement between tests results. In addition, we examined health workers performance of the testing procedure when attending patients at a health facility, using a predefined checklist. Towards the end of the study, an evaluation of health worker acceptability was carried out to assess preferences between the two RDT QA methods. We received 2369 samples and 2324 (98%) had complete information. mRDTs had the highest positivity rate (6.5%). The proportion of positive tests by all types of tests was slightly higher in Iringa DC, but only qPCR and BS2 showed statistically significant differences in positivity rate between the two districts, where Iringa DC had more positive tests than Mufindi DC (p<0.05). When qPCR was a gold standard, mRDTs had higher sensitivity (68.6%, 95%CI: 55.0-79.7) than microscopy (53.7%, 95%CI: 38.7- 68.0) but highest mRDT sensitivity was achieved with comparison to microscopy (85.3%, 95%CI: 70.0- 93.6). All tests had higher inter-observer agreement than would be expected by chance. Substantial high inter-observer agreement (kappa =0.75; p<0.001) was seen amongst the microscopists i.e. district’s quality assurance officers and the reference microscopy readings. Assessment of the time needed to process BS at the district level revealed that, smears at district level took on average 8 days (min 2 to max 33) to be processed and provide feedback; but up to an average of 44 days (min 19 to max 98) to get a second reading. Many health workers were aware that the use of mRDTs was due to changes in treatment policy (11/30), and patients who qualify for the test are those suspected to have malaria. Majority (16/30) related assessment of control line as a measure of test accuracy and suggested the use of microscopy for quality control of mRDT results (15/30). Their major concerns were mRDTs’ inability to give parasite count, stock-out of the tests kits in their working areas and the frequency of negative results. This evaluation encountered several challenges, among them were 1. Poor quality of blood smears made at health facilities, especially dispensaries, which do not have laboratory services. 2. About 3.5% of BS1 slides could not be processed for BS2 because they were damaged during transportation and/or poor quality of smears. This accounts for the small difference in the numbers of BS assessed between two readers. 3. We were not able to prepare standard concentration solutions for qPCR analysis in the country. 4. Problems with PCR machine and inability to repair it that necessitated shipment of the machine, to and from, the manufacturers in Europe (Germany). Malaria RDT QA Final Report, March 2012 6 Due to these challenges, qPCR results were not available until after specimen collection had ended. In this study malaria positivity was higher with mRDTs than microscopy and qPCR for the 200 parasites/μL lower boundary of positivity threshold. This could either be due to the strict lower cut-off point for microscopy and qPCR parasite density or higher false positivity of mRDTs due to persistent antigen in blood, errors in mRDTs performance or other patient’s characteristics. When qPCR was taken as gold standard, mRDTs showed better sensitivity than microscopy, but when microscopy was regarded as a gold standard, mRDTs showed higher sensitivity than with qPCR. However, results of qPCR demonstrated a better correlation (inter-observer agreement) with those of microscopy than with mRDTs. The challenges of performing qPCR, as observed in this evaluation, make it unsuitable for quality assurance of mRDTs in routine care, Tanzania. The high inter-observer agreement between districts’ and reference microscopists (K=0.75) and higher tests performances of BS1 when BS2 was a comparator, demonstrates the competence shown by district’s technicians/ technologists to suffice their involvement as reference microscopists for quality assurance of mRDTs in their respective districts. This is also complimented by a fact that, both BS1 and BS2 had more similar performance when qPCR was taken as a gold standard. In this setting, a microscopy-based quality assurance system to assess mRDT performance in routine use may be a practical and suitable method. However, long distance transportation of smears should be avoided.\u

Social Defense: An Evolutionary-Developmental Model of Children’s Strategies for Coping with Threat in the Peer Group

Navigating the ubiquitous conflict, competition, and complex group dynamics of the peer group is a pivotal developmental task of childhood. Difficulty negotiating these challenges represents a substantial source of risk for psychopathology. Evolutionary developmental psychology offers a unique perspective with the potential to reorganize the way we think about the role of peer relationships in shaping how children cope with the everyday challenges of establishing a social niche. To address this gap, we utilize the ethological reformulation of the emotional security theory as a guide to developing an evolutionary framework for advancing an understanding of the defense strategies children use to manage antagonistic peer relationships and protect themselves from interpersonal threat (Davies and Sturge-Apple, 2007). In this way, we hope to illustrate the value of an evolutionary developmental lens in generating unique theoretical insight and novel research directions into the role of peer relationships in the development of psychopathology

Red Giant Eclipsing Binaries: Exploring Non-Oscillators and Testing Asteroseismic Scalings

Thanks to advances in asteroseismology, red giants have become astrophysical laboratories for probing the Milky Way. Eclipsing binaries allow us to directly measure stellar properties independently of asteroseismology, which we use to investigate why some red giants don't oscillate and test asteroseismic scaling relations for those that do. By combining orbital solutions, high-resolution spectroscopy, and stellar evolution models for a subset of eight eclipsing red giants observed by Kepler, we find short-period binaries with strong tidal forces and systems with active red giants are less likely to exhibit solar-like oscillations. We also preview the results from Gaulme et al. 2016 (submitted). We find asteroseismic scalings overestimate red giant radii by about 6% on average and masses by about 16% in ten systems observed by Kepler. Systematic overestimation of mass leads to underestimation of stellar age, which has important implications for ensemble asteroseismology applied to galactic studies

Parametric Trace Slicing

A program trace is obtained and events of the program trace are traversed. For each event identified in traversing the program trace, a trace slice of which the identified event is a part is identified based on the parameter instance of the identified event. For each trace slice of which the identified event is a part, the identified event is added to an end of a record of the trace slice. These parametric trace slices can be used in a variety of different manners, such as for monitoring, mining, and predicting

Four-month moxifloxacin-based regimens for drug-sensitive tuberculosis

Supported by the Global Alliance for TB Drug Development with support from the Bill and Melinda Gates Foundation, the European and Developing Countries Clinical Trials Partnership, U.S. Agency for International Development, U.K. Department for International Development, Directorate General for International Cooperation of the Netherlands, Irish Aid, Australia Department of Foreign Affairs and Trade, and National Institutes of Health, AIDS Clinical Trials Group and by grants from the National Institute of Allergy and Infectious Diseases (NIAID) (UM1AI068634, UM1 AI068636, and UM1AI106701) and by NIAID grants to the University of KwaZulu Natal, South Africa, AIDS Clinical Trials Group (ACTG) site 31422 (1U01AI069469); to the Perinatal HIV Research Unit, Chris Hani Baragwanath Hospital, South Africa, ACTG site 12301 (1U01AI069453); and to the Durban International Clinical Trials Unit, South Africa, ACTG site 11201 (1U01AI069426); Bayer Healthcare for the donation of moxifloxacin; and Sanofi for the donation of rifampin.Background: Early-phase and preclinical studies suggest that moxifloxacin-containing regimens could allow for effective 4-month treatment of uncomplicated, smear-positive pulmonary tuberculosis. Methods: We conducted a randomized, double-blind, placebo-controlled, phase 3 trial to test the noninferiority of two moxifloxacin-containing regimens as compared with a control regimen. One group of patients received isoniazid, rifampin, pyrazinamide, and ethambutol for 8 weeks, followed by 18 weeks of isoniazid and rifampin (control group). In the second group, we replaced ethambutol with moxifloxacin for 17 weeks, followed by 9 weeks of placebo (isoniazid group), and in the third group, we replaced isoniazid with moxifloxacin for 17 weeks, followed by 9 weeks of placebo (ethambutol group). The primary end point was treatment failure or relapse within 18 months after randomization. Results: Of the 1931 patients who underwent randomization, in the per-protocol analysis, a favorable outcome was reported in fewer patients in the isoniazid group (85%) and the ethambutol group (80%) than in the control group (92%), for a difference favoring the control group of 6.1 percentage points (97.5% confidence interval [CI], 1.7 to 10.5) versus the isoniazid group and 11.4 percentage points (97.5% CI, 6.7 to 16.1) versus the ethambutol group. Results were consistent in the modified intention-to-treat analysis and all sensitivity analyses. The hazard ratios for the time to culture negativity in both solid and liquid mediums for the isoniazid and ethambutol groups, as compared with the control group, ranged from 1.17 to 1.25, indicating a shorter duration, with the lower bounds of the 95% confidence intervals exceeding 1.00 in all cases. There was no significant difference in the incidence of grade 3 or 4 adverse events, with events reported in 127 patients (19%) in the isoniazid group, 111 (17%) in the ethambutol group, and 123 (19%) in the control group. Conclusions: The two moxifloxacin-containing regimens produced a more rapid initial decline in bacterial load, as compared with the control group. However, noninferiority for these regimens was not shown, which indicates that shortening treatment to 4 months was not effective in this setting. (Funded by the Global Alliance for TB Drug Development and others; REMoxTB ClinicalTrials.gov number, NCT00864383.)Publisher PDFPeer reviewe