The functional validation of a state-of-the-art digital design is usually performed by simulation of a register-transfer-level model. The degree to which the test vector suite covers the important tests is known as the coverage of the suite. Previous coverage metrics have relied on measures such as the number of simulated cycles or number of toggles on a circuit node, which are indirect metrics at best. This paper proposes a new method of analyzing coverage based on projecting a minimized control finite-state graph onto control signals for the datapath part of the design to yield a meaningful metric and provide detailed feedback about missing tests. The largest hurdle is state-space explosion. We describe two methods of dealing with this in a practical manner and give results of applying this coverage analysis to parts of the node controller of the Stanford FLASH multiprocessor.
ABSTRACT Objectives To determine the presence of a set of pre-specified traditional and progressive criteria used to assess scientists for promotion and tenure in faculties of biomedical sciences among universities worldwide. Design Cross-sectional study. Setting Not applicable. Participants 170 randomly selected universities from the Leiden Ranking of world universities list were considered. Main outcome measures Two independent reviewers searched for all guidelines applied when assessing scientists for promotion and tenure for institutions with biomedical faculties. Where faculty-level guidelines were not available, institution-level guidelines were sought. Available documents were reviewed and the presence of 5 traditional (e.g., number of publications) and 7 progressive (e.g., data sharing) criteria was noted in guidelines for assessing assistant professors, associate professors, professors, and the granting of tenure. Results A total of 146 institutions had faculties of biomedical sciences with 92 having eligible guidelines available to review. Traditional criteria were more commonly reported than progressive criteria (t(82)= 15.1, p= .001). Traditional criteria mentioned peer-reviewed publications, authorship order, journal impact, grant funding, and national or international reputation in 95%, 37%, 28%, 67%, and 48% of the guidelines, respectively. Conversely, among progressive criteria only citations (any mention in 26%) and accommodations for extenuating circumstances (37%) were relatively commonly mentioned; while there was rare mention of alternative metrics for sharing research (2%) and data sharing (1%), and 3 criteria (publishing in open access mediums, registering research, and adhering to reporting guidelines) were not found in any institution reviewed. We observed notable differences across continents on whether guidelines are accessible or not (Australia 100%, North America 97%, Europe 50%, Asia 58%, South America 17%), and more subtle differences on the use of specific criteria. Conclusions This study demonstrates that the current evaluation of scientists emphasizes traditional criteria as opposed to progressive criteria. This may reinforce research practices that are known to be problematic while insufficiently supporting the conduct of better-quality research and open science. Institutions should consider incentivizing progressive criteria. Registration Open Science Framework ( https://osf.io/26ucp/ ) What is already known on this topic Academics tailor their research practices based on the evaluation criteria applied within their academic institution. Ensuring that biomedical researchers are incentivized by adhering to best practice guidelines for research is essential given the clinical implications of this work. While changes to the criteria used to assess professors and confer tenure have been recommended, a systematic assessment of promotion and tenure criteria being applied worldwide has not been conducted. What this study adds Across countries, university guidelines focus on rewarding traditional research criteria (peer-reviewed publications, authorship order, journal impact, grant funding, and national or international reputation). The minimum requirements for promotion and tenure criteria are predominantly objective in nature, although several of them are inadequate measures to assess the impact of researchers. Developing and evaluating more appropriate, progressive indicators of research may facilitate changes in the evaluation practices for rewarding researchers.
The recent publication of first results from the “Reproducibility Project: Cancer Biology” has stirred debate. The project synopsis put together by Nosek and Errington (1) tried to describe carefully what replication means, how to judge whether “same” (or different) results emerge in a replication experiment, and how to interpret divergent results in original vs reproducibility studies. However, multiple other commentators on these first reproducibility studies have enhanced our uncertainty. Almost every commentator reached a somewhat different conclusion. Reproducibility of inferences has been dismal. Several authors of the original papers along with other commentators have questioned the reproducibility effort. These retorts typically defend the original findings, interpreting the replications as more successful than unsuccessful. They question replications on multiple fronts, e.g., inappropriate statistical methods or poor experimental competence. They lament the inappropriate shaming consequences, when poorly done replication efforts tarnish great scientists. They worry that reproducibility checks destroy discovery and stall efforts to translate promising research. They wonder whether we should waste money on replication. The reproducibility wars are not exclusive to laboratory science. Last year, a similar debate erupted with a Technical Comment exchange on the respective reproducibility project on psychology (2), although the available data were far more extensive (100 experiments instead of just 5 preliminary ones) and had a massive participation of top psychologists (270 scientists and their teams) trying to reproduce results. Some famous psychology academics nevertheless concluded that their field had no reproducibility problem and reproducibility was misleading business. This position is immediately suspect. If psychological science is so perfect, how can it be that 270 of the best psychologists in the world working under optimal conditions of openness and most rigorous protocols and methods could get everything so badly wrong? If the most closely controlled and scrutinized corpus of experiments ever done on psychological science …
fMRI research is highly prolific but raises multiple concerns. Many competing statistical methods and respective packages are available using different assumptions, none of which applies equally well to all settings. However, the most fundamental concerns are not about the statistical machinery, but about issues of reproducibility, utility, and even construct validity. One can probe how much the field would benefit by statistical refinements, the conduct of larger studies and/or improved reproducibility practices. Alternatively, maybe fMRI research should largely be abandoned with focus shifting toward developing imaging methods with construct validity for granular neuronal activity and higher potential for clinical utility.
In this Viewpoint, John Ioannidis discusses implications of the 2017 hypertension guidelines for real-world management of blood pressure (BP), including labeling healthy people as having disease and possible adverse treatment effects at lower BP treatment targets..
© Copyright CLINICALAND EXPERIMENTAL RHEUMATOLOGY 2004. Pulmonary interstitial fibrosis (PIF) affects half of all patients with systemic sclerosis (SSc) (1) and accounts for one-third of SSc-related deaths (2). Despite enormous efforts, therapy remains empirical and its efficacy is questionable. D-penicillamine (3) interfero n -γ (4), and cyclophosphamide (5) have been used to halt the progression of PIF. While studies on these regimens have reported encouraging results, patients still die from respiratory failure due to PIF. For instance, D-penicillamine was shown to have beneficial effects for SSc lung disease, as detected by increased values of DLCO/lung volumes (3), but hardly anyone believes in this therapy today. This is probably a reflection of the weak design and lack of methodological credibility of most studies performed in SSc. There are several reasons for this situation. First, the natural history of the disease is not well known, and therefore slow disease progression due to the disease itself could be spuriously considered as stabilization due to the therapy for some patients, while for patients with an unfavourable disease profile at entry regression-to-the-mean is a problem in uncontrolled studies (6). Second, the duration of follow-up in patients receiving a therapeutic intervention under evaluation is usually short. Third, the small numbers of patients per cohort do not favour the adoption of randomized controlled studies, and whenever such studies are undertaken, small sample sizes are the rule (7). Finally, surrogate markers are used for the response instead of hard clinical outcomes, and these surrogates have their limitations. Nevertheless these surrogate markers probably represent very early changes of lung function, in a time point when the involvement of the lung can regress without serious consequences for the health of the individual. Therefore these markers have been proposed for future studies in the Portonovo Conference on the evaluation of patients with systemic scleroderma (8). At the same time, very little progress has been made at the basic science level to suppress fibrotic processes. Airo et al. in this issue of the journal (9) report their experience with intravenous cyclophosphamide therapy for SSc PIF in a retrospective, observational study. They also attempted to enhance their findings by reviewing five other relevant studies (10-14). However, they were not able to adopt a standard protocol and use standardized individual level data from all the previous cohorts. Pooling was performed on the data of 3 of the 6 studies. The endpoint of the study by Airo et al. was alterations in lung function tests after 6 months (9). The regimen used was cyclophosphamide 750 mg pulses combined with methylprednisolone 125 mg pulses every 3 weeks and the results were promising. Despite the small numbers, lack of prospective or even retrospective control subjects, and the limitations of retrospective evaluation, practically all the studies reporting the results of cyclophosphamide therapy in SSc PIF have suggested that cyclophosphamide may be more or less efficacious for PIF. However, the outcomes have not been the same between studies, the prednisolone dose differs significantly between them, and the baseline characteristics of the patients are considerably different across studies. For instance, the patients in the study of Pakas et al. (12) had considerably advanced disease at the initiation of treatment, while the patients in the study by Giacomelli et al. (14) had initial FVC levels within normal range. While the results are promising, the need for caution cannot be overstated. There are several issues regarding the definition of the disease and outcomes thereof that have to be considered in future studies (15). First, what is the histopathologic subset of fibrosing alveolitis in patients with SSc? It is well known today that non-specific interstitial pneumonia (NSIP) and usual interstitial pneumonia (UIP) are two histopathologic types with different outcomes, and they may coexist in patients with scleroderma lung disease but to a different extent from one patient to another (16). Second, is PIF clinically significant? Pulmonary function tests and dyspnea scoring are the only widely available means of determining wheEDITORIAL Clinical and Experimental Rheumatology 2004; 22: 551-552.
Proposes a digital controller for adaptive power-supply regulation that uses sliding control, which is a widely used technique in switching power supplies for its fast transient response and robust stability. A novel reformulation of the sliding control law enables a simple and power-efficient digital implementation. The reference circuit can be either a delay line or a ring oscillator, and the sensor circuits for both cases are discussed. The prototype chip fabricated in 0.25-/spl mu/m CMOS technology demonstrates a power efficiency of 89% - 95 % over the regulated voltage range of 1.1 - 2.3 V.
The study protocol was pre-registered on 4 April 2019 and is available at https://osf.io/hbkj3/. The protocol was hidden under embargo for the duration of the survey to avoid contamination of participant responses. The introductory text of this report is largely based on the text of the pre-registered document. All procedural deviations from the pre-registered protocol are explicitly acknowledged in this article. All data exclusions and measures conducted during this study are reported in this article. Data, materials and analysis scripts related to this study are publicly available at https://osf.io/8aenp/. To facilitate reproducibility, the analysis script is available in a Code Ocean container (https://doi.org/10.24433/CO.3912558.v1) which re-creates the software environment in which the original analyses were performed. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.
