ABSTRACT Printed articles increasingly rely on online supplements to store critical scientific information, but such data may eventually become unavailable. We checked the current availability of online supplementary scientific information published in six top‐cited scientific journals ( Science, Nature, Cell, New England Journal of Medicine, Lancet, Proceedings of the National Academy of Sciences USA ). Here we show that in 4.7% and 9.6% of articles with online supplementary material, some of the supplements became unavailable within 2 and 5 years of their publication, respectively.—Evangelou, E., Trikalinos, T. A., Ioannidis, J. P. A. Unavailability of online supplementary scientific information from articles published in major journals. FASEB J. 19, 1943–1944 (2005)
The foremost goal of superscalar processor design is to increase performance through the exploitation of instruction-level parallelism (ILP). Previous studies have shown that speculative execution is required for high instruction per cycle (IPC) rates in non-numerical applications. The general trend has been toward supporting speculative execution in complicated, dynamically-scheduled processors. Performance, though, is more than just a high IPC rate; it also depends upon instruction count and cycle time. Boosting is an architectural technique that supports general speculative execution in simpler, statically-scheduled processors. Boosting labels speculative instructions with their control dependence information. This labelling eliminates control dependence constraints on instruction scheduling while still providng full dependence information to the hardware. We have incorporated boosting into a trace-based, global scheduling algorithm that exploits ILP without adversely affecting the instruction count of a program. We use this algorithm and estimates of the boosting hardware involved to evaluate how much speculative execution support is really necessary to achieve good performance. We find that a statically-scheduled superscalar processor using a minimal implementation of boosting can easily reach the performance of a much more complex dynamically-scheduled superscalar processor.
SRT [Sweeney, Robertson and Tocher (1958)] dividers are common in modern floating point units. Higher division performance is achieved by retiring more quotient bits in each cycle. Previous research has shown that realistic stages are limited to radix-2 and radix-4. Higher radix dividers are therefore formed by a combination of low-radix stages. In this paper, we present an analysis of the effects of radix-2 and radix-4 SRT divider architectures and circuit families on divider area and performance. We show the performance and area results for a wide variety of divider architectures and implementations. We conclude that divider performance is only weakly sensitive to reasonable choices of architecture but significantly improved by aggressive circuit techniques.
In this metaepidemiological study, admission and mortality outcomes did not correlate, and discordances occurred in about one-third of the treatment comparisons included in our analyses. Both outcomes convey useful information and should be reported separately, but extrapolating the benefits of admission to survival is unreliable and should be avoided.
This Viewpoint discusses reports from China after its zero COVID-19 policy ended in December 2022.
Multiple treatment comparison (MTC) meta-analysis uses both direct (head-to-head) randomized clinical trial (RCT) evidence as well as indirect evidence from RCTs to compare the relative effectiveness of all included interventions. The methodological quality of MTCs may be difficult for clinicians to interpret because the number of interventions evaluated may be large and the methodological approaches may be complex. Clinicians and others evaluating an MTC should be aware of the potential biases that can affect the interpretation of these analyses. Readers should consider whether the primary studies are sufficiently homogeneous to combine; whether the different interventions are sufficiently similar in their populations, study designs, and outcomes; and whether the direct evidence is sufficiently similar to the indirect evidence to consider combining. This article uses the existing Users' Guides format to address study validity, interpretation of results, and application to a patient scenario.
To cope with poor quality in cryo-electron tomography images, electron-dense markers, such as colloidal goldbeads, are often used to assist image registration and analysis algorithms. However, these markers can create artifacts that occlude a specimen due to their high contrast, which can also cause failure of some image processing algorithms. One way of reducing these artifacts is to replace high contrast objects with pixel densities that blend into the surroundings in the projection domain before volume reconstruction. In this paper, we propose digital inpainting via compressed sensing (CS) as a new method to achieve this goal. We show that cryo-ET projections are sparse in the discrete cosine transform (DCT) domain, and, by finding the sparsest DCT domain decompositions given uncorrupted pixels, we can fill in the missing pixel values that are occluded by high contrast objects without discontinuities. Our method reduces visual artifacts both in projections and in tomograms better than conventional algorithms, such as polynomial interpolation and random noise inpainting.
The problem of detecting a signal that has both magnitude and sign is considered. A new type of correlation device, which employs the derivative of the correlation function, is proposed for measuring target range and position, and an analysis to determine the most useful waveform is made. The effects of white noise accompanying the input signal are minimized when an input waveform of long duration, wide bandwidth, and high derivative power is chosen.
There are too many studies with statistically significant results in the literature on brain volume abnormalities. This pattern suggests strong biases in the literature, with selective outcome reporting and selective analyses reporting being possible explanations.
Article Free Access Share on Modeling the performance of limited pointers directories for cache coherence Authors: Richard Simoni Computer Systems Laboratory, Stanford University, Stanford, CA Computer Systems Laboratory, Stanford University, Stanford, CAView Profile , Mark Horowitz Computer Systems Laboratory, Stanford University, Stanford, CA Computer Systems Laboratory, Stanford University, Stanford, CAView Profile Authors Info & Claims ISCA '91: Proceedings of the 18th annual international symposium on Computer architectureApril 1991Pages 309–319https://doi.org/10.1145/115952.115983Published:01 April 1991Publication History 10citation365DownloadsMetricsTotal Citations10Total Downloads365Last 12 Months44Last 6 weeks13 Get Citation AlertsNew Citation Alert added!This alert has been successfully added and will be sent to:You will be notified whenever a record that you have chosen has been cited.To manage your alert preferences, click on the button below.Manage my AlertsNew Citation Alert!Please log in to your account Save to BinderSave to BinderCreate a New BinderNameCancelCreateExport CitationPublisher SiteeReaderPDF
