790 research outputs found
Measurement-Based Analysis of Multiple Errors and Near-Coincident Fault Discovery in a Shared Memory Multiprocessor
Coordinated Science Laboratory was formerly known as Control Systems LaboratoryNational Aeronautics and Space Administration / NASA NAG-1-61
Non-equilibrium dynamics of isolated quantum systems
The non-equilibrium dynamics of isolated quantum systems represent a theoretical and experimental challenge raising many fundamental questions with applications to different fields of modern physics. In these proceedings, we briefly review some of the recent findings on the subject, with particular emphasis to the existence of stationary expectation values of local observables and to their statistical mechanics description. It turns out that the appropriate statistical ensemble describing these asymptotic values depends on whether the Hamiltonian governing the time evolution is integrable or not
Background Independent Quantum Gravity: A Status Report
The goal of this article is to present an introduction to loop quantum
gravity -a background independent, non-perturbative approach to the problem of
unification of general relativity and quantum physics, based on a quantum
theory of geometry. Our presentation is pedagogical. Thus, in addition to
providing a bird's eye view of the present status of the subject, the article
should also serve as a vehicle to enter the field and explore it in detail. To
aid non-experts, very little is assumed beyond elements of general relativity,
gauge theories and quantum field theory. While the article is essentially
self-contained, the emphasis is on communicating the underlying ideas and the
significance of results rather than on presenting systematic derivations and
detailed proofs. (These can be found in the listed references.) The subject can
be approached in different ways. We have chosen one which is deeply rooted in
well established physics and also has sufficient mathematical precision to
ensure that there are no hidden infinities. In order to keep the article to a
reasonable size, and to avoid overwhelming non-experts, we have had to leave
out several interesting topics, results and viewpoints; this is meant to be an
introduction to the subject rather than an exhaustive review of it.Comment: 125 pages, 5 figures (eps format), the final version published in CQ
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Detection of Oxidation Products of 5-Methyl-2′-Deoxycytidine in Arabidopsis DNA
Epigenetic regulations play important roles in plant development and adaptation to environmental stress. Recent studies
from mammalian systems have demonstrated the involvement of ten-eleven translocation (Tet) family of dioxygenases in
the generation of a series of oxidized derivatives of 5-methylcytosine (5-mC) in mammalian DNA. In addition, these oxidized
5-mC nucleobases have important roles in epigenetic remodeling and aberrant levels of 5-hydroxymethyl-29-deoxycytidine
(5-HmdC) were found to be associated with different types of human cancers. However, there is a lack of evidence
supporting the presence of these modified bases in plant DNA. Here we reported the use of a reversed-phase HPLC coupled
with tandem mass spectrometry method and stable isotope-labeled standards for assessing the levels of the oxidized 5-mC
nucleosides along with two other oxidatively induced DNA modifications in genomic DNA of Arabidopsis. These included 5-
HmdC, 5-formyl-29-deoxycytidine (5-FodC), 5-carboxyl-29-deoxycytidine (5-CadC), 5-hydroxymethyl-29-deoxyuridine (5-
HmdU), and the (59S) diastereomer of 8,59-cyclo-29-deoxyguanosine (S-cdG). We found that, in Arabidopsis DNA, the levels
of 5-HmdC, 5-FodC, and 5-CadC are approximately 0.8 modifications per 106 nucleosides, with the frequency of 5-HmdC
(per 5-mdC) being comparable to that of 5-HmdU (per thymidine). The relatively low levels of the 5-mdC oxidation products
suggest that they arise likely from reactive oxygen species present in cells, which is in line with the lack of homologous Tetfamily
dioxygenase enzymes in Arabidopsis
Hindu-Muslim Violence in India: A Postscript from the Twenty-First Century
The importance of religious conflict today can hardly be overstated. The appalling situation in Syria—stemming from the activism of the Islamic State (ISIS)—is just one cruel reminder of the utter devastation that religious extremism can wreak. The tragic humanitarian crisis in Myanmar involving the displacement of the Rohingya Muslims has strong religious overtones, as do the attacks on Muslims and Christians by Buddhist nationalist groups in Sri Lanka
Gravitational Waves From Known Pulsars: Results From The Initial Detector Era
We present the results of searches for gravitational waves from a large selection of pulsars using data from the most recent science runs (S6, VSR2 and VSR4) of the initial generation of interferometric gravitational wave detectors LIGO (Laser Interferometric Gravitational-wave Observatory) and Virgo. We do not see evidence for gravitational wave emission from any of the targeted sources but produce upper limits on the emission amplitude. We highlight the results from seven young pulsars with large spin-down luminosities. We reach within a factor of five of the canonical spin-down limit for all seven of these, whilst for the Crab and Vela pulsars we further surpass their spin-down limits. We present new or updated limits for 172 other pulsars (including both young and millisecond pulsars). Now that the detectors are undergoing major upgrades, and, for completeness, we bring together all of the most up-to-date results from all pulsars searched for during the operations of the first-generation LIGO, Virgo and GEO600 detectors. This gives a total of 195 pulsars including the most recent results described in this paper.United States National Science FoundationScience and Technology Facilities Council of the United KingdomMax-Planck-SocietyState of Niedersachsen/GermanyAustralian Research CouncilInternational Science Linkages program of the Commonwealth of AustraliaCouncil of Scientific and Industrial Research of IndiaIstituto Nazionale di Fisica Nucleare of ItalySpanish Ministerio de Economia y CompetitividadConselleria d'Economia Hisenda i Innovacio of the Govern de les Illes BalearsNetherlands Organisation for Scientific ResearchPolish Ministry of Science and Higher EducationFOCUS Programme of Foundation for Polish ScienceRoyal SocietyScottish Funding CouncilScottish Universities Physics AllianceNational Aeronautics and Space AdministrationOTKA of HungaryLyon Institute of Origins (LIO)National Research Foundation of KoreaIndustry CanadaProvince of Ontario through the Ministry of Economic Development and InnovationNational Science and Engineering Research Council CanadaCarnegie TrustLeverhulme TrustDavid and Lucile Packard FoundationResearch CorporationAlfred P. Sloan FoundationAstronom
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