9,204 research outputs found

    First results on the performance of the CMS global calorimeter trigger

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    The CMS Global Calorimeter Trigger (GCT) uses data from the CMS calorimeters to compute a number kinematical quantities which characterize the LHC event. The GTC output is used by the Global Trigger (GT) along with data from the Global Muon Trigger (GMT) to produce the Level-1 Accept (L1A) decision. The design for the current GCT system commenced early in 2006. After a rapid development phase all the different GCT components have been produced and a large fraction of them have been installed at the CMS electronics cavern (USC-55). There the GCT system has been under test since March 2007. This paper reports results from tests which took place at the USC-55. Initial tests aimed to test the integrity of the GCT data and establish that the proper synchronization had been achieved both internally within GCT as well as with the Regional Calorimeter Trigger (RCT) which provides the GCT input data and with GT which receives the GCT results. After synchronization and data integrity had been established, Monte Carlo Events with electrons in the final state were injected at the GCT inputs and were propagated to the GCT outputs. The GCT output was compared with the predictions of the GCT emulator model in the CMS Monte Carlo and were found to be identical

    Revised CMS Global Calorimeter Trigger Functionality & Algorithms

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    The Global Calorimeter Trigger (GCT) is a device which uses data from the CMS calorimeters to search for jets, produce isolated and non-isolated electron lists and compute all the transverse and missing transverse energy sums used for the Level-1 trigger decision (L1A). GCT performs these functions by receiving and processing the data from the Regional Calorimeter Trigger (RCT) and transmitting a summary to the Global Trigger (GT) which computes the L1A decision. The GCT must also transmit a copy of the RCT and GCT data to the CMS DAQ. The vast amount of data received by the GCT (230 Gb/s) as well as the necessity for data sharing required by the jet finder impose severe constrains on the GCT design. This paper presents an overview of the revised design, in particular, the algorithms, data flow and associated latency within the revised GCT

    Performance of the CMS Global Calorimeter Trigger

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    The CMS Global Calorimeter Trigger system performs a wide-variety of calorimeter data processing functions required by the CMS Level-1 trigger. It is responsible for finding and classifying jets and tau-jets, calculating total and missing transverse energy, total transverse energy identified within jets, sorting e/γ\gamma candidates, and calculating several quantities based on forward calorimetry for minimum-bias triggers. The system is based on high-speed serial optical links and large FPGAs. The system has provided CMS with calorimeter triggers during commissioning and cosmic runs throughout 2008. The performance of the system in validation tests and cosmic runs is presented here

    Knot Theory: from Fox 3-colorings of links to Yang-Baxter homology and Khovanov homology

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    This paper is an extended account of my "Introductory Plenary talk at Knots in Hellas 2016" conference We start from the short introduction to Knot Theory from the historical perspective, starting from Heraclas text (the first century AD), mentioning R.Llull (1232-1315), A.Kircher (1602-1680), Leibniz idea of Geometria Situs (1679), and J.B.Listing (student of Gauss) work of 1847. We spend some space on Ralph H. Fox (1913-1973) elementary introduction to diagram colorings (1956). In the second section we describe how Fox work was generalized to distributive colorings (racks and quandles) and eventually in the work of Jones and Turaev to link invariants via Yang-Baxter operators, here the importance of statistical mechanics to topology will be mentioned. Finally we describe recent developments which started with Mikhail Khovanov work on categorification of the Jones polynomial. By analogy to Khovanov homology we build homology of distributive structures (including homology of Fox colorings) and generalize it to homology of Yang-Baxter operators. We speculate, with supporting evidence, on co-cycle invariants of knots coming from Yang-Baxter homology. Here the work of Fenn-Rourke-Sanderson (geometric realization of pre-cubic sets of link diagrams) and Carter-Kamada-Saito (co-cycle invariants of links) will be discussed and expanded. Dedicated to Lou Kauffman for his 70th birthday.Comment: 35 pages, 31 figures, for Knots in Hellas II Proceedings, Springer, part of the series Proceedings in Mathematics & Statistics (PROMS

    The future of social is personal: the potential of the personal data store

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    This chapter argues that technical architectures that facilitate the longitudinal, decentralised and individual-centric personal collection and curation of data will be an important, but partial, response to the pressing problem of the autonomy of the data subject, and the asymmetry of power between the subject and large scale service providers/data consumers. Towards framing the scope and role of such Personal Data Stores (PDSes), the legalistic notion of personal data is examined, and it is argued that a more inclusive, intuitive notion expresses more accurately what individuals require in order to preserve their autonomy in a data-driven world of large aggregators. Six challenges towards realising the PDS vision are set out: the requirement to store data for long periods; the difficulties of managing data for individuals; the need to reconsider the regulatory basis for third-party access to data; the need to comply with international data handling standards; the need to integrate privacy-enhancing technologies; and the need to future-proof data gathering against the evolution of social norms. The open experimental PDS platform INDX is introduced and described, as a means of beginning to address at least some of these six challenges

    Identification and characterization of an inhibitory fibroblast growth factor receptor 2 (FGFR2) molecule, up-regulated in an Apert Syndrome mouse model

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    AS (Apert syndrome) is a congenital disease composed of skeletal, visceral and neural abnormalities, caused by dominant-acting mutations in FGFR2 [FGF (fibroblast growth factor) receptor 2]. Multiple FGFR2 splice variants are generated through alternative splicing, including PTC (premature termination codon)-containing transcripts that are normally eliminated via the NMD (nonsense-mediated decay) pathway. We have discovered that a soluble truncated FGFR2 molecule encoded by a PTC-containing transcript is up-regulated and persists in tissues of an AS mouse model. We have termed this IIIa–TM as it arises from aberrant splicing of FGFR2 exon 7 (IIIa) into exon 10 [TM (transmembrane domain)]. IIIa–TM is glycosylated and can modulate the binding of FGF1 to FGFR2 molecules in BIAcore-binding assays. We also show that IIIa–TM can negatively regulate FGF signalling in vitro and in vivo. AS phenotypes are thought to result from gain-of-FGFR2 signalling, but our findings suggest that IIIa–TM can contribute to these through a loss-of-FGFR2 function mechanism. Moreover, our findings raise the interesting possibility that FGFR2 signalling may be a regulator of the NMD pathway

    Carbon clusters near the crossover to fullerene stability

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    The thermodynamic stability of structural isomers of C24\mathrm{C}_{24}, C26\mathrm{C}_{26}, C28\mathrm{C}_{28} and C32\mathrm{C}_{32}, including fullerenes, is studied using density functional and quantum Monte Carlo methods. The energetic ordering of the different isomers depends sensitively on the treatment of electron correlation. Fixed-node diffusion quantum Monte Carlo calculations predict that a C24\mathrm{C}_{24} isomer is the smallest stable graphitic fragment and that the smallest stable fullerenes are the C26\mathrm{C}_{26} and C28\mathrm{C}_{28} clusters with C2v\mathrm{C}_{2v} and Td\mathrm{T}_{d} symmetry, respectively. These results support proposals that a C28\mathrm{C}_{28} solid could be synthesized by cluster deposition.Comment: 4 pages, includes 4 figures. For additional graphics, online paper and related information see http://www.tcm.phy.cam.ac.uk/~prck

    Changing knowledge, attitudes and behaviours towards cytomegalovirus in pregnancy through film-based antenatal education: a feasibility randomised controlled trial of a digital educational intervention

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    Background Congenital cytomegalovirus (CMV) is the most common congenital infection globally, however information about CMV is not routinely included in antenatal education in the United Kingdom. This feasibility study aimed to gather the essential data needed to design and power a large randomised controlled trial (RCT) to investigate the efficacy of a digital intervention in reducing the risk of CMV acquisition in pregnancy. In order to do this, we carried out a single-centre RCT, which explored the knowledge, attitudes and risk reduction behaviours in women in the intervention and treatment as usual groups, pre- and post-intervention. Methods CMV seronegative women living with a child less than four years old, receiving antenatal care at a single UK tertiary centre, were randomised to the digital intervention or ‘treatment as usual’ groups. Participants completed questionnaires before the digital intervention and after and at 34 gestational weeks, and responses within groups and between groups were compared using tailored randomisation tests. CMV serology was tested in the first trimester and at the end of pregnancy. Results Of the 878 women screened, 865 samples were analysed with 43% (n = 372) being CMV seronegative and therefore eligible to take part in the RCT; of these, 103 (27.7%) women were enrolled and 87 (84%) of these completed the study. Most participants (n = 66; 64%) were unfamiliar with CMV at enrolment, however at 34 gestational weeks, women in the intervention group (n = 51) were more knowledgeable about CMV compared to the treatment as usual group (n = 52) and reported engaging in activities that may increase the risk of CMV transmission less frequently. The digital intervention was highly acceptable to pregnant women. Overall, four participants seroconverted over the course of the study: two from each study group. Conclusions A large multi-centre RCT investigating the efficacy of a CMV digital intervention is feasible in the United Kingdom; this study has generated essential data upon which to power such a study. This single-centre feasibility RCT demonstrates that a digital educational intervention is associated with increase in knowledge about CMV and can result in behaviour change which may reduce the risk of CMV acquisition in pregnancy

    The effect of temperature, farm density and foot-and-mouth disease restrictions on the 2007 UK bluetongue outbreak

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    In 2006, bluetongue (BT), a disease of ruminants, was introduced into northern Europe for the first time and more than two thousand farms across five countries were affected. In 2007, BT affected more than 35,000 farms in France and Germany alone. By contrast, the UK outbreak beginning in 2007 was relatively small, with only 135 farms in southeast England affected. We use a model to investigate the effects of three factors on the scale of BT outbreaks in the UK: (1) place of introduction; (2) temperature; and (3) animal movement restrictions. Our results suggest that the UK outbreak could have been much larger had the infection been introduced into the west of England either directly or as a result of the movement of infected animals from southeast England before the first case was detected. The fact that air temperatures in the UK in 2007 were marginally lower than average probably contributed to the UK outbreak being relatively small. Finally, our results indicate that BT movement restrictions are effective at controlling the spread of infection. However, foot-and-mouth disease restrictions in place before the detection and control of BT in 2007 almost certainly helped to limit BT spread prior to its detection
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