468 research outputs found

    Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV

    Get PDF
    The performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 inverse picobarns of data collected in pp collisions at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum pT larger than a few GeV is above 95% over the whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4, while the probability to misidentify a hadron as a muon is well below 1%. The efficiency to trigger on single muons with pT above a few GeV is higher than 90% over the full eta range, and typically substantially better. The overall momentum scale is measured to a precision of 0.2% with muons from Z decays. The transverse momentum resolution varies from 1% to 6% depending on pseudorapidity for muons with pT below 100 GeV and, using cosmic rays, it is shown to be better than 10% in the central region up to pT = 1 TeV. Observed distributions of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO

    Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV

    Get PDF
    The performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 inverse picobarns of data collected in pp collisions at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum pT larger than a few GeV is above 95% over the whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4, while the probability to misidentify a hadron as a muon is well below 1%. The efficiency to trigger on single muons with pT above a few GeV is higher than 90% over the full eta range, and typically substantially better. The overall momentum scale is measured to a precision of 0.2% with muons from Z decays. The transverse momentum resolution varies from 1% to 6% depending on pseudorapidity for muons with pT below 100 GeV and, using cosmic rays, it is shown to be better than 10% in the central region up to pT = 1 TeV. Observed distributions of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO

    Azimuthal anisotropy of charged particles at high transverse momenta in PbPb collisions at sqrt(s[NN]) = 2.76 TeV

    Get PDF
    The azimuthal anisotropy of charged particles in PbPb collisions at nucleon-nucleon center-of-mass energy of 2.76 TeV is measured with the CMS detector at the LHC over an extended transverse momentum (pt) range up to approximately 60 GeV. The data cover both the low-pt region associated with hydrodynamic flow phenomena and the high-pt region where the anisotropies may reflect the path-length dependence of parton energy loss in the created medium. The anisotropy parameter (v2) of the particles is extracted by correlating charged tracks with respect to the event-plane reconstructed by using the energy deposited in forward-angle calorimeters. For the six bins of collision centrality studied, spanning the range of 0-60% most-central events, the observed v2 values are found to first increase with pt, reaching a maximum around pt = 3 GeV, and then to gradually decrease to almost zero, with the decline persisting up to at least pt = 40 GeV over the full centrality range measured.Comment: Replaced with published version. Added journal reference and DO

    Search for new physics with same-sign isolated dilepton events with jets and missing transverse energy

    Get PDF
    A search for new physics is performed in events with two same-sign isolated leptons, hadronic jets, and missing transverse energy in the final state. The analysis is based on a data sample corresponding to an integrated luminosity of 4.98 inverse femtobarns produced in pp collisions at a center-of-mass energy of 7 TeV collected by the CMS experiment at the LHC. This constitutes a factor of 140 increase in integrated luminosity over previously published results. The observed yields agree with the standard model predictions and thus no evidence for new physics is found. The observations are used to set upper limits on possible new physics contributions and to constrain supersymmetric models. To facilitate the interpretation of the data in a broader range of new physics scenarios, information on the event selection, detector response, and efficiencies is provided.Comment: Published in Physical Review Letter

    Compressed representation of a partially defined integer function over multiple arguments

    Get PDF
    In OLAP (OnLine Analitical Processing) data are analysed in an n-dimensional cube. The cube may be represented as a partially defined function over n arguments. Considering that often the function is not defined everywhere, we ask: is there a known way of representing the function or the points in which it is defined, in a more compact manner than the trivial one

    City Blueprints: Baseline Assessments of Sustainable Water Management in 11 Cities of the Future

    Get PDF
    The necessity of Urban Water Cycle Services (UWCS) adapting to future stresses calls for changes that take sustainability into account. Megatrends (e.g. population growth, water scarcity, pollution and climate change) pose urgent water challenges in cities. In a previous paper, a set of indicators, i.e., the City Blueprint has been developed to assess the sustainability ofUWCS (Van Leeuwen et al.,Wat Resour Manage 26:2177¿2197, 2012). In this paper this approach has been applied in 9 cities and regions in Europe (Amsterdam, Algarve, Athens, Bucharest, Hamburg, Reggio Emilia, Rotterdam, Oslo and Cities of Scotland) and in 2 African cities in Angola (Kilamba Kiaxi) and Tanzania (Dar es Salaam). The assessments showed that cities vary considerably with regard to the sustainability of theUWCS. This is also captured in the Blue City Index (BCI), the arithmetic mean of 24 indicators comprising the City Blueprint (Van Leeuwen et al., Wat Resour Manage 26:2177¿2197, 2012). Theoretically, the BCI has a minimum score of 0 and a maximum score of 10. The actual BCIs in the 11 cities studied varied from 3.31 (Kilamba Kiaxi) to 7.72 (Hamburg). The BCI was positively correlated with the Gross Domestic Product (GDP) per person, the ambitions of the local authorities regarding the sustainability of the UWCS, the voluntary participation index (VPI) and all governance indicators according to the World Bank. The study demonstrated that the variability in sustainability among the UWCS of cities offers great opportunities for short-term and long-term improvements, provided that cities share their best practices.Van Leeuwen, CJ. (2013). City Blueprints: Baseline Assessments of Sustainable Water Management in 11 Cities of the Future. Water resources management. https://doi.org/10.1007/s11269-013-0462-5Bai X (2007) Industrial ecology and the global impacts of cities. J Industr Ecol 11:1–6Brown RR, Keath N, Wong THF (2009) Urban water management in cities: Historical, current and future regimes. Water Sci Technol 59:847–855De Graaf R, van de Giessen N, van de Ven F (2007a) Alternative water management options to reduce vulnerability for climate change in the Netherlands. Nat Hazards 5:407–422De Graaf RE, van de Giessen NC, van de Ven FHM (2007b) The closed city as a strategy to reduce vulnerability of urban areas for climate change. Water Sci Technol 56:165–173EEA (2010) European Environment Agency. The European environment. State and outlook 2010. Synthesis. Copenhagen, DenmarkEEA (2012) European Environment Agency. Urban adaptation to climate change in Europe. Challenges and opportunities for cities together with supportive national and European policies. Synthesis, Copenhagen, DenmarkEFILWC (2006) First European quality of life survey: participation in civil society. European Foundation for the Improvement of Living and Working Conditions, Dublin. http://www.eurofound.europa.eu/publications/htmlfiles/ef0676.htm . Accessed 21 February 2011Engel K, Jokiel D, Kraljevic A, Geiger M, Smith K (2011) Big cities. Big water. Big challenges. Water in an urbanizing world. World wildlife fund, KoberichEnvironmental Performance Index (2010) http://www.epi2010.yale.edu/Metrics/WaterEffectsOnEcosystem . Accessed 30 March 2012European Commission (2012) Communication from the Commission to the European Parliament, the Council, the European Economic and Social Committee and the Committee of the Regions. A Blueprint to Safeguard Europe’s Water Resources. COM (2012)673 finalEuropean Commission (2013) European Innovation Partnership on water (EIP Water). http://ec.europa.eu/environment/water/innovationpartnership/European green city index (2009) Assessing the environmental impact of Europe’s major cities. A research project conducted by the Economist Intelligence Unit, http://www.siemens.com/press/pool/de/events/corporate/2009-12-Cop15/European_Green_City_Index.pdf . Accessed 20 February 2011Grimm NB, Faeth SH, Golubiewski NE, Redman CL, Wu J, Bai X, Briggs JM (2008) Global change and the ecology of cities. Science 319(5864):756–760Hoekstra AY, Mekonnen MM, Chapagain AK, Mathews RE, Richter BD (2012) Global monthly water scarcity: Blue water footprints versus blue water availability. PLoS ONE 7(2):e32688. doi: 10.1371/journal.pone.0032688IMF (2012) Gross Domestic Product (international dollars) as provided by the International Monetary Fund for 2010–2011: http://en.wikipedia.org/wiki/List_of_countries_by_GDP_(PPP)_per_capita . Accessed October 2012Kaufman D, Kraay A, Mastruzzi M (2010) The worldwide governance indicators. Methodology and analytical issues. World Bank Policy Research Working Paper 5430. World Bank, Washington DCLange P, Driessen PJ, Sauer A, Borneman B, Burger P (2013) Governing towards sustainability – conceptualizing modes of governance. J Environ Policy Planning 15:403–425Makropoulos CK, Butler D (2010) Distributed water infrastructure for sustainable communities. Water Resour Manag 24(11):2795–2816Mekonnen MM, Hoekstra AY (2011) National water footprint accounts: the green, blue and grey water footprint of production and consumption. Volumes 1 and 2. Value of Water Research Report Series No. 50. UNESCO-IHE, Delft, the NetherlandsNorman E, Bakker K, Cook C, Dunn G, Allen D (2010) Water security: A primer. Policy report. Fostering water security in Canada Project www.watergovernance.ca Accessed 20 September 2013Philip R, Anton B, van der Steen P (2011) SWITCH training kit. Integrated urban water management in the city of the future. Module 1. Strategic planning, ICLEI, Freiburg, GermanyPrüss-Üstün A, Bos R, Gore F, Bartram J (2008) Safer water, better health: Costs, benefits and sustainability of interventions to protect and promote health. World Health Organization, GenevaRozos E, Makropoulos C (2013) Source to tap urban water cycle modelling. Environ Model Softw 41:139–150SIWI (2012) Stockholm International Water Institute. Statistics. http://www.siwi.org/sa/node.asp?node=159 Accessed 20 December, 2012Ugarelli R, Pachioli M, Di Federico V (2009) Planning maintenance strategies for Italian urban drainage systems applying CARE-S. In: Allegre H, do Céu Almeida M (eds) Strategic asset management of water supply and wastewater infrastructures. IWA Publishing, London, pp 471–486UN (2012) World urbanization prospects: The 2011 revision. UN, New York, USA. http://esa.un.org/unup/ . Accessed 30 November 2012UNDP (2004) Water governance for poverty reduction. USA, New YorkUNEP (2008) Every drop counts; environmentally sound technologies for urban and domestic water use efficiency. Switzerland, GenevaUNEP (2012) Fifth global environment outlook: Environment for the future we want. Switzerland, GenevaUNESCO (2012) Managing water under uncertainty and risk. Facts and figures from the UN world water development report 4. http://unesdoc.unesco.org/images/0021/002154/215492e.pdf . Accessed 20 December 2012UN-Habitat (2010). Climate change strategy 2010–2013. Urban Environmental Planning Branch, Nairobi, Kenia. http://www.google.nl/search?sourceid=navclient&ie=UTF-8&rlz=1T4MXGB_enNL512NL512&q=Climate+change+strategy+2010-2013 . Accessed 20 December 2012Van Leeuwen CJ (2007) Introduction. In: Van Leeuwen CJ, Vermeire TG (eds) Risk Assessment of Chemicals. An Introduction. Springer, Dordrecht, 2nd edn, pp. 1–36Van Leeuwen CJ, Frijns J, Van Wezel A, Van De Ven FHM (2012) City blueprints: 24 indicators to assess the sustainability of the urban water cycle. Wat Resour Manage 26:2177–2197Van Leeuwen CJ, Chandy PC (2013) The city blueprint: Experiences with the implementation of 24 indicators to assess the sustainability of the urban water cycle. Water Sci Technol 13(3):769–781Van Leeuwen K, Marques RC (2013) Current state of sustainability of urban water cycle services. Transition to the Urban Water Services of tomorrow (TRUST) report D11.1. http://www.trust-i.net/downloads/index.php?iddesc=682030 Water Resources Group (2009) Charting our water future. Economic framework to inform decisionmaking. West Perth, USA. http://www.mckinsey.com/App_Media/Reports/Water/Charting_Our_Water_Future_Full_Report_001.pdf . Accessed 20 February 2011World Bank (2013) Worldwide Governance Indicators. http://info.worldbank.org/governance/wgi/index.asp . Accessed 30 March 2013.World Economic Forum (2013) Global Risks, 8th edn. Geneva, Switzerland. http://reports.weforum.org/global-risks-2013/ Accessed 30 March 201

    A Concerted HIF-1α/MT1-MMP Signalling Axis Regulates the Expression of the 3BP2 Adaptor Protein in Hypoxic Mesenchymal Stromal Cells

    Get PDF
    Increased plasticity, migratory and immunosuppressive abilities characterize mesenchymal stromal cells (MSC) which enable them to be active participants in the development of hypoxic solid tumours. Our understanding of the oncogenic adaptation of MSC to hypoxia however lacks the identification and characterization of specific biomarkers. In this study, we assessed the hypoxic regulation of 3BP2/SH3BP2 (Abl SH3-binding protein 2), an immune response adaptor/scaffold protein which regulates leukocyte differentiation and motility. Gene silencing of 3BP2 abrogated MSC migration in response to hypoxic cues and generation of MSC stably expressing the transcription factor hypoxia inducible factor 1alpha (HIF-1α) resulted in increased endogenous 3BP2 expression as well as cell migration. Analysis of the 3BP2 promoter sequence revealed only one potential HIF-1α binding site within the human but none in the murine sequence. An alternate early signalling cascade that regulated 3BP2 expression was found to involve membrane type-1 matrix metalloproteinase (MT1-MMP) transcriptional regulation which gene silencing abrogated 3BP2 expression in response to hypoxia. Collectively, we provide evidence for a concerted HIF-1α/MT1-MMP signalling axis that explains the induction of adaptor protein 3BP2 and which may link protein binding partners together and stimulate oncogenic MSC migration. These mechanistic observations support the potential for malignant transformation of MSC within hypoxic tumour stroma and may contribute to evasion of the immune system by a tumour
    corecore