6,047 research outputs found
DPA on quasi delay insensitive asynchronous circuits: formalization and improvement
The purpose of this paper is to formally specify a flow devoted to the design
of Differential Power Analysis (DPA) resistant QDI asynchronous circuits. The
paper first proposes a formal modeling of the electrical signature of QDI
asynchronous circuits. The DPA is then applied to the formal model in order to
identify the source of leakage of this type of circuits. Finally, a complete
design flow is specified to minimize the information leakage. The relevancy and
efficiency of the approach is demonstrated using the design of an AES
crypto-processor.Comment: Submitted on behalf of EDAA (http://www.edaa.com/
Evaluation tests of platinum resistance thermometers for a cryogenic wind tunnel application
Thirty-one commercially designed platinum resistance thermometers were evaluated for applicability to stagnation temperature measurements between -190 C and +65 C in the Langley Research Center's National Transonic Facility. Evaluation tests included X-ray shadowgraphs, calibrations before and after aging, and time constant measurements. Two wire-wound low thermal mass probes of a conventional design were chosen as most suitable for this cryogenic wind tunnel application
Des allers-retours sans retour? L'entre-deux dans Tombeau de Romain Gary et Limbes/Limbo: Hommage Ă Samuel Beckett de Nancy Huston
Nancy Huston a publié à trois ans d’intervalles deux œuvres dont les titres symétriques incitent à les étudier ensemble : Tombeau de Romain Gary en 1995 et Limbes/Limbo, hommage à Samuel Beckett en 1998. Sont ainsi réunis ici trois auteurs, figures de l’entre-deux des langues et des cultures, trois auteurs qui ont choisi le français comme langue d’expression, une langue qui n’était pas leur langue maternelle. A ce jour, Nancy Huston n’a pas publié d’autres hommages de ce type à d’autres auteurs, faisant de ce trio – dont elle fait partie – un ensemble arrêté. Ecrire entre deux langues, soit en écrivant dans une langue qui n’est pas sa langue maternelle, soit en s’auto-traduisant, c’est échapper aux règles des deux langues. C’est une façon d’être insaisissable mais aussi d’éviter que sa langue soit saisie par une autorité, c’est créer un espace de liberté pour la création littéraire
Low-latency analysis pipeline for compact binary coalescences in the advanced gravitational wave detector era
The multi-band template analysis (MBTA) pipeline is a low-latency coincident
analysis pipeline for the detection of gravitational waves (GWs) from compact
binary coalescences. MBTA runs with a low computational cost, and can identify
candidate GW events online with a sub-minute latency. The low computational
running cost of MBTA also makes it useful for data quality studies. Events
detected by MBTA online can be used to alert astronomical partners for
electromagnetic follow-up. We outline the current status of MBTA and give
details of recent pipeline upgrades and validation tests that were performed in
preparation for the first advanced detector observing period. The MBTA pipeline
is ready for the outset of the advanced detector era and the exciting prospects
it will bring.Comment: 18 pages, 10 figure
3-hydroxykynurenine suppresses CD4+ T-cell proliferation, induces T-regulatory-cell development, and prolongs corneal allograft survival
Copyright © 2011 Association for Research in Vision and Ophthalmology. This article is available open access through the publisher’s website at the link below.Purpose. IDO (indoleamine 2,3-dioxygenase) modulates the immune response by depletion of the essential amino acid tryptophan, and IDO overexpression has been shown to prolong corneal allograft survival. This study was conducted to examine the effect of kynurenines, the products of tryptophan breakdown and known to act directly on T lymphocytes, on corneal graft survival.
Methods. The effects of kynurenines on T-cell proliferation and death, T-regulatory-cell development, and dendritic cell function, phenotype, and viability were analyzed in vitro. The effect of topical and systemic administration of 3-hydroxykynurenine (3HK) on orthotopic murine corneal allograft survival was examined.
Results. T-lymphocyte proliferation was inhibited by two of the four different kynurenines: 3HK and 3-hydroxyanthranilic acid (3HAA). This effect was accompanied by significant T-cell death. Neither 3HK nor 3HAA altered dendritic cell function, nor did they induce apoptosis or pathogenicity to corneal endothelial cells. Administration of systemic and topical 3HK to mice receiving a fully mismatched corneal graft resulted in significant prolongation of graft survival (median survival of control grafts, 12 days; of treated, 19 and 15 days, respectively; P < 0.0003). While systemic administration of 3HK was associated with a significant depletion of CD4+ T, CD8+ T, and B lymphocytes in peripheral blood, no depletion was found after topical administration.
Conclusions. The production of kynurenines, in particular 3HK and 3HAA, may be one mechanism (in addition to tryptophan depletion) by which IDO prolongs graft survival. These molecules have potential as specific agents for preventing allograft rejection in patients at high rejection risk.Fight for Sight and the Wellcome Trust
A preliminary study of factors affecting the calibration stability of the iridium versus iridium-40 percent rhodium thermocouple
An iridium versus iridium-40% rhodium thermocouple was studied. Problems associated with the use of this thermocouple for high temperature applications (up to 2000 C) were investigated. The metallurgical studies included X-ray, macroscopic, resistance, and metallographic studies. The thermocouples in the as-received condition from the manufacturer revealed large amounts of internal stress caused by cold working during manufacturing. The thermocouples also contained a large amount of inhomogeneities and segregations. No phase transformations were observed in the alloy up to 1100 C. It was found that annealing the thermocouple at 1800 C for two hours, and then at 1400 C for 2 to 3 hours yielded a fine grain structure, relieving some of the strains, and making the wire more ductile. It was also found that the above annealing procedure stabilized the thermal emf behavior of the thermocouple for application below 1800 C (an improvement from + or - 1% to + or - 0.02% within the range of the test parameters used)
Sea state monitoring using coastal GNSS-R
We report on a coastal experiment to study GPS L1 reflections. The campaign
was carried out at the Barcelona Port breaker and dedicated to the development
of sea-state retrieval algorithms. An experimental system built for this
purpose collected and processed GPS data to automatically generate a times
series of the interferometric complex field (ICF). The ICF was analyzed off
line and compared to a simple developed model that relates ICF coherence time
to the ratio of significant wave height (SWH) and mean wave period (MWP). The
analysis using this model showed good consistency between the ICF coherence
time and nearby oceanographic buoy data. Based on this result, preliminary
conclusions are drawn on the potential of coastal GNSS-R for sea state
monitoring using semi-empirical modeling to relate GNSS-R ICF coherence time to
SWH.Comment: All Starlab authors have contributed significantly; the Starlab
author list has been ordered randomly. Submitted to GR
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