40 research outputs found

    Desynchronization: Synthesis of asynchronous circuits from synchronous specifications

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    Asynchronous implementation techniques, which measure logic delays at run time and activate registers accordingly, are inherently more robust than their synchronous counterparts, which estimate worst-case delays at design time, and constrain the clock cycle accordingly. De-synchronization is a new paradigm to automate the design of asynchronous circuits from synchronous specifications, thus permitting widespread adoption of asynchronicity, without requiring special design skills or tools. In this paper, we first of all study different protocols for de-synchronization and formally prove their correctness, using techniques originally developed for distributed deployment of synchronous language specifications. We also provide a taxonomy of existing protocols for asynchronous latch controllers, covering in particular the four-phase handshake protocols devised in the literature for micro-pipelines. We then propose a new controller which exhibits provably maximal concurrency, and analyze the performance of desynchronized circuits with respect to the original synchronous optimized implementation. We finally prove the feasibility and effectiveness of our approach, by showing its application to a set of real designs, including a complete implementation of the DLX microprocessor architectur

    Developing a collaborative project on higher education pedagogy: The institutional, organizational, and community identity dimensions of student staff partnerships

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    This case study presents an ambitious student-staff partnership project at University College London (UCL) to publish a collaborative book on higher education pedagogy. Over two-and-a-half years, a total of 86 students and staff contributed to the project, which sought to provide educators with a new type of scholarly material under the unifying theme of connecting research and teaching. Multiple layers of student-staff partnership were interwoven throughout the project; this case study contextualizes these layers against three dimensions: institutional, organizational, and community identity. Central to the project was our distinctive approach to engaging with Graduate Teaching Assistants (GTAs) and their crucial role in bringing the three dimensions together. As such, the project represents a model of enhanced student-staff partnership that has the capacity to empower students and break down educational silos to form new, multi-specialty learning communities.</jats:p

    CircumMed+Euro pine forest database: an electronic archive for Mediterranean and European forests

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    Large thematic databases of vegetation-plots are increasingly needed for vegetation studies and biodiversity research. In this paper, we present the CircumMed+Euro Pine Forest Database (GIVD ID: EU-00-026), which in September 2018 encompassed 5590 records from pine-dominated vegetation plots (relevés) and associated vegetation types from 23 countries of temperate Europe, Eastern Mediterranean and North Africa. These vegetation plots were collected through a detailed literature search for plots not included in the European Vegetation Archive (EVA). The database includes plots from 192 bibliographic references and unpublished vegetation plots by different authors. All vegetation plots are georeferenced, and coordinates are available with different accuracy as reported by the authors. The database is managed by the Vegetation Science Group, Department of Botany and Zoology of the Masaryk University in Brno (Czech Republic). It is registered in the Global Index of Vegetation-Plot Databases (GIVD) with the code EU-00-026 and is accessible through the European Vegetation Archive (EVA) or by asking the Custodian. The CircumMed+Euro Pine Forest Database is an important resource for conducting different types of broad-scale studies in the fields of vegetation classification, plant invasion ecology, macroecology and biological conservationN/

    Processed pseudogenes acquired somatically during cancer development

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    Cancer evolves by mutation, with somatic reactivation of retrotransposons being one such mutational process. Germline retrotransposition can cause processed pseudogenes, but whether this occurs somatically has not been evaluated. Here we screen sequencing data from 660 cancer samples for somatically acquired pseudogenes. We find 42 events in 17 samples, especially non-small cell lung cancer (5/27) and colorectal cancer (2/11). Genomic features mirror those of germline LINE element retrotranspositions, with frequent target-site duplications (67%), consensus TTTTAA sites at insertion points, inverted rearrangements (21%), 5′ truncation (74%) and polyA tails (88%). Transcriptional consequences include expression of pseudogenes from UTRs or introns of target genes. In addition, a somatic pseudogene that integrated into the promoter and first exon of the tumour suppressor gene, MGA, abrogated expression from that allele. Thus, formation of processed pseudogenes represents a new class of mutation occurring during cancer development, with potentially diverse functional consequences depending on genomic context

    Retrospective evaluation of whole exome and genome mutation calls in 746 cancer samples

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    Funder: NCI U24CA211006Abstract: The Cancer Genome Atlas (TCGA) and International Cancer Genome Consortium (ICGC) curated consensus somatic mutation calls using whole exome sequencing (WES) and whole genome sequencing (WGS), respectively. Here, as part of the ICGC/TCGA Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium, which aggregated whole genome sequencing data from 2,658 cancers across 38 tumour types, we compare WES and WGS side-by-side from 746 TCGA samples, finding that ~80% of mutations overlap in covered exonic regions. We estimate that low variant allele fraction (VAF < 15%) and clonal heterogeneity contribute up to 68% of private WGS mutations and 71% of private WES mutations. We observe that ~30% of private WGS mutations trace to mutations identified by a single variant caller in WES consensus efforts. WGS captures both ~50% more variation in exonic regions and un-observed mutations in loci with variable GC-content. Together, our analysis highlights technological divergences between two reproducible somatic variant detection efforts

    Coping with the variability of combinational logic delays

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    This paper proposes a technique for creating a combinational logic network with an output that signals when all other outputs have stabilized. The method is based on dual-rail encoding, and guarantees low timing overhead and reasonable area and power overhead. We discuss various scenarios in which completion detection can be used to measure the delay of a synchronous circuit at fabrication time or at run time, and of an asynchronous circuit at run time. We conclude by showing, on a large set of benchmarks, the effectiveness of the proposed technique.Peer Reviewe

    From synchronous to asynchronous: an automatic approach

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    This paper presents a methodology to derive asynchronous circuits from optimized synchronous circuits by replacing the clock distribution tree by a handshaking network. A case study shows the applicability of the method and the potential benefits of de-synchronizing synchronous circuits.Peer Reviewe
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