520 research outputs found

    inSense: A Variation and Fault Tolerant Architecture for Nanoscale Devices

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    Transistor technology scaling has been the driving force in improving the size, speed, and power consumption of digital systems. As devices approach atomic size, however, their reliability and performance are increasingly compromised due to reduced noise margins, difficulties in fabrication, and emergent nano-scale phenomena. Scaled CMOS devices, in particular, suffer from process variations such as random dopant fluctuation (RDF) and line edge roughness (LER), transistor degradation mechanisms such as negative-bias temperature instability (NBTI) and hot-carrier injection (HCI), and increased sensitivity to single event upsets (SEUs). Consequently, future devices may exhibit reduced performance, diminished lifetimes, and poor reliability. This research proposes a variation and fault tolerant architecture, the inSense architecture, as a circuit-level solution to the problems induced by the aforementioned phenomena. The inSense architecture entails augmenting circuits with introspective and sensory capabilities which are able to dynamically detect and compensate for process variations, transistor degradation, and soft errors. This approach creates ``smart\u27\u27 circuits able to function despite the use of unreliable devices and is applicable to current CMOS technology as well as next-generation devices using new materials and structures. Furthermore, this work presents an automated prototype implementation of the inSense architecture targeted to CMOS devices and is evaluated via implementation in ISCAS \u2785 benchmark circuits. The automated prototype implementation is functionally verified and characterized: it is found that error detection capability (with error windows from β‰ˆ\approx30-400ps) can be added for less than 2\% area overhead for circuits of non-trivial complexity. Single event transient (SET) detection capability (configurable with target set-points) is found to be functional, although it generally tracks the standard DMR implementation with respect to overheads

    Effect of Ceftazidime on Systemic Cytokine Concentrations in Rats

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    The effect of a single dose of ceftazidime on circulating concentrations of interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α) in a rat model of sepsis was studied. IL-6 concentrations were significantly elevated (100 to 200 times the baseline) 6 h after ceftazidime administration in both septic and nonseptic (control) rats. TNF-α concentrations increased significantly in nonseptic (∼40 times the baseline) rats but not septic (∼2 to 3 times the baseline) rats. Ceftazidime administration was not associated with an increase in endotoxin concentrations. These findings suggest that ceftazidime modulation of proinflammatory cytokine concentrations may be independent of its antimicrobial properties

    Genomic comparison of diverse Salmonella serovars isolated from swine.

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    Food animals act as a reservoir for many foodborne pathogens. Salmonella enterica is one of the leading pathogens that cause food borne illness in a broad host range including animals and humans. They can also be associated with a single host species or a subset of hosts, due to genetic factors associated with colonization and infection. Adult swine are often asymptomatic carriers of a broad range of Salmonella servoars and can act as an important reservoir of infections for humans. In order to understand the genetic variations among different Salmonella serovars, Whole Genome Sequences (WGS) of fourteen Salmonella serovars from swine products were analyzed. More than 75% of the genes were part of the core genome in each isolate and the higher fraction of gene assign to different functional categories in dispensable genes indicated that these genes acquired for better adaptability and diversity. High concordance (97%) was detected between phenotypically confirmed antibiotic resistances and identified antibiotic resistance genes from WGS. The resistance determinants were mainly located on mobile genetic elements (MGE) on plasmids or integrated into the chromosome. Most of known and putative virulence genes were part of the core genome, but a small fraction were detected on MGE. Predicted integrated phage were highly diverse and many harbored virulence, metal resistance, or antibiotic resistance genes. CRISPR (Clustered regularly interspaced short palindromic repeats) patterns revealed the common ancestry or infection history among Salmonella serovars. Overall genomic analysis revealed a great deal of diversity among Salmonella serovars due to acquired genes that enable them to thrive and survive during infection

    Hydrogen Peroxide Stimulates Activity and Alters Behavior in Drosophila melanogaster

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    Circadian rhythms in animals are regulated at the level of individual cells and by systemic signaling to coordinate the activities of multiple tissues. The circadian pacemakers have several physiological outputs, including daily locomotor rhythms. Several redox-active compounds have been found to function in regulation of circadian rhythms in cells, however, how particular compounds might be involved in regulating specific animal behaviors remains largely unknown. Here the effects of hydrogen peroxide on Drosophila movement were analyzed using a recently developed three-dimensional real-time multiple fly tracking assay. Both hydrogen peroxide feeding and direct injection of hydrogen peroxide caused increased adult fly locomotor activity. Continuous treatment with hydrogen peroxide also suppressed daily locomotor rhythms. Conditional over-expression of the hydrogen peroxide-producing enzyme superoxide dismutase (SOD) also increased fly activity and altered the patterns of locomotor activity across days and weeks. The real-time fly tracking system allowed for detailed analysis of the effects of these manipulations on behavior. For example, both hydrogen peroxide feeding and SOD over-expression increased all fly motion parameters, however, hydrogen peroxide feeding caused relatively more erratic movement, whereas SOD over-expression produced relatively faster-moving flies. Taken together, the data demonstrate that hydrogen peroxide has dramatic effects on fly movement and daily locomotor rhythms, and implicate hydrogen peroxide in the normal control of these processes

    Design and operation of automated ice-tethered profilers for real-time seawater observations in the polar oceans

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    An automated, easily-deployed Ice-Tethered Profiler (ITP) has been developed for deployment on perennial sea ice in polar oceans to measure changes in upper ocean temperature and salinity in all seasons. The ITP system consists of three components: a surface instrument that sits atop an ice floe, a weighted, plastic-jacketed wire-rope tether of arbitrary length (up to 800 m) suspended from the surface instrument, and an instrumented underwater unit that profiles up and down the wire tether. The profiling underwater unit is similar in shape and dimension to an ARGO float except that the float's variable-buoyancy system is replaced with a traction drive unit. Deployment of ITPs may be conducted either from ice caps or icebreakers, utilizing a self contained tripod/winch system that requires no power. Careful selection of an appropriate multiyear ice floe is needed to prolong the lifetime of the system (up to 3 years depending on the profiling schedule). Shortly after deployment, each ITP begins profiling the water column at its programmed sampling interval. After each acquired temperature and salinity profile, the underwater unit (PROCON) transfers the data and engineering files using an inductive modem to the surface controller (SURFCON). SURFCON also accumulates battery voltages, buoy temperature, and locations from GPS at specified intervals in status files, and queues that information for transmission at the start of each new day. At frequent intervals, an Iridium satellite transceiver in the surface package calls and transmits queued status and CTD data files onto a WHOI logger computer, which are subsequently processed and displayed in near-real time at http://www.whoi.edu/itp. In 2004 and 2005, three ITP prototypes were deployed in the Arctic Ocean. Each system was programmed with accelerated sampling schedules of multiple one-way traverses per day between 10 and 750-760 m depth in order to quickly evaluate endurance and component fatigue. Two of the ITPs are continuing to function after more than 10 months and 1200 profiles. Larger motor currents are observed at times of fast ice floe motion when larger wire angles develop and drag forces on the profiler are increased. The CTD profile data so far obtained document interesting spatial variations in the major water masses of the Beaufort Gyre, show the double-diffusive thermohaline staircase that lies above the warm, salty Atlantic layer, and many mesoscale eddys. Deployed together with CRREL Ice Mass Balance (IMB) buoys, these ITP systems also operate as part of an Ice Based Observatory (IBO). Data returned from an array of IBOs within an Arctic Observing Network will provide valuable real time observations, support studies of ocean processes, and facilitate numerical model initialization and validation.Funding was provided by the National Science Foundation under Contract Nos. OCE-0324233 and ARC-0519899

    Pennsylvania Folklife Vol. 46, No. 2

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    β€’ An Uncommon Woman in the Age of the Common Man: The Life and Times of Sarah Righter Major β€’ Maintaining Mennonite Identity: The Old Order Church in Pennsylvania and Virginia β€’ The End of an Era: The Last One-Room Public Schools in Lebanon County β€’ Pennsylvania Extended in the Cherokee Country: A Study of Log Architecturehttps://digitalcommons.ursinus.edu/pafolklifemag/1148/thumbnail.jp

    The Ursinus Weekly, March 1, 1973

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    New USGA officers initiate programs β€’ Ursinus Union apparently an instant, smash success β€’ 1973 Arts Festival begins Friday, March 2 β€’ Ursinus affiliates with United Student Aid Funds β€’ Editorial: The Union β€’ First Union concert presents blend of folk, blues, jazz β€’ New Ruby to be different from former edition β€’ English department will show Oedipus the King β€’ Ursinus beats West Chester in last minute of play β€’ Bears upset LVC β€’ U.C. volleyball clinic features Canadians β€’ Rambo sets record as intercollegiate champ β€’ Letterhttps://digitalcommons.ursinus.edu/weekly/1098/thumbnail.jp

    The Ursinus Weekly, November 7, 1974

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    The Great Pumpkin comes to U.C. β€’ Course Directory Catalogue Committee formed by U.S.G.A. β€’ Antigone is ProTheatre\u27s production β€’ Union does it again β€’ Criminal law featured as Forum topic β€’ Letters to the editor: Epitaph on an Ursinus transfer β€’ Pages from Ursinus past: A legend β€’ Perusing Pfahler\u27s pigeons β€’ New Economics head β€’ Equus reviewed β€’ Concerts: Bizarre and sublime β€’ Record review β€’ Nate DuPree: Can a black man find happiness at Ursinus? β€’ Martha Franklin: A half century of service to our students and campus β€’ Readin\u27, ritin\u27 and new math β€’ Introducing campus leaders β€’ Football wrapup: Swarthmore; Widener β€’ Hockey teams win the big games! β€’ Harriers 6-4 on seasonhttps://digitalcommons.ursinus.edu/weekly/1024/thumbnail.jp

    Analysis of seafloor seismograms of the 2003 Tokachi-Oki earthquake sequence for earthquake early warning

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    Author Posting. Β© American Geophysical Union, 2008. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 35 (2008): L14310, doi:10.1029/2008GL033986.Earthquake Early Warning (EEW) algorithms estimate the magnitude of an underway rupture from the first few seconds of the P-wave to allow hazard assessment and mitigation before the S-wave arrival. Many large subduction-zone earthquakes initiate 50–150 km offshore, potentially allowing seafloor instruments sufficient time to identify large ruptures before the S-waves reach land. We tested an EEW algorithm using accelerograms recorded offshore Hokkaido in the region of the 2003 Mw 8.1 Tokachi-Oki earthquake and its aftershocks. A wavelet transform of the first ∼4 s of the P-wave concentrates information about earthquake magnitude from both waveform amplitude and frequency content. We find that wavelets with support of a few seconds provide discriminants for EEW that are both accurate enough to be useful and superior to peak acceleration or peak velocity. Additionally, we observe a scaling of wavelet coefficient magnitude above Mw 6.0 indicating that, at least for the mainshock (Mw 8.1) and largest aftershock (Mw 7.1), the final size of a rupture could have been estimated from the initial portion of the seismogram.This work was supported by the Deep Ocean Exploration Institute at WHOI

    A Climatology of Cold-Season Nonconvective Wind Events in the Great Lakes Region

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    A 44-yr climatology of nonconvective wind events (NCWEs) for the Great Lakes region has been created using hourly wind data for 38 first-order weather stations during the months of November through April. The data were analyzed in terms of the two National Weather Service (NWS) criteria for a high-wind watch or warning: sustained winds of at least 18 m s-1for at least 1 h or a wind gust of at least 26 m s-1for any duration. The results indicate a pronounced southwest quadrant directional preference for nonconvective high winds in this region. Between 70% and 76% of all occurrences that satisfied the NWS criteria for NCWEs were associated with wind directions from 180Β° through 270Β°. Within the southwest quadrant, the west-southwest direction is preferred, with 14%-35% of all NCWEs coming from this particular compass heading. This directional preference is borne out in five out of six stations with high occurrences of cold-season NCWEs (Buffalo, New York; Dayton, Ohio; Lansing, Michigan; Moline, Illinois; Springfield, Illinois). Given the geographic spread of these stations, a nontopographic cause for the directional preference of cold-season NCWEs is indicated. The connection between NCWEs and low pressure systems found in this climatology and in case studies suggests that midlatitude cyclone dynamics may be a possible cause of the directional preference
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