461 research outputs found
Light-cone-like spreading of correlations in a quantum many-body system
How fast can correlations spread in a quantum many-body system? Based on the
seminal work by Lieb and Robinson, it has recently been shown that several
interacting many-body systems exhibit an effective light cone that bounds the
propagation speed of correlations. The existence of such a "speed of light" has
profound implications for condensed matter physics and quantum information, but
has never been observed experimentally. Here we report on the time-resolved
detection of propagating correlations in an interacting quantum many-body
system. By quenching a one-dimensional quantum gas in an optical lattice, we
reveal how quasiparticle pairs transport correlations with a finite velocity
across the system, resulting in an effective light cone for the quantum
dynamics. Our results open important perspectives for understanding relaxation
of closed quantum systems far from equilibrium as well as for engineering
efficient quantum channels necessary for fast quantum computations.Comment: 7 pages, 5 figures, 2 table
Adoptive immunotherapy against allogeneic kidney grafts in dogs with stable hematopoietic trichimerism.
Dogs given nonmyeloablative conditioning and marrow grafts from 2 dog leukocyte antigen (DLA)-identical littermate donors developed stable trichimerism and stably accepted a subsequent kidney graft from one of the marrow donors without the need for immunosuppression. In this study, we used trichimeras to evaluate strategies for adoptive immunotherapy to solid tumors, using the kidney as a tumor surrogate. Three DLA-identical trichimeric recipients were established by simultaneously infusing marrow from 2 DLA-identical donor dogs into a DLA-identical recipient conditioned with 2 Gy of total body irradiation (TBI) and given a short course of postgraft immunosuppression. After stable hematopoietic engraftment was confirmed, a kidney was transplanted from 1 of the 2 marrow donors into each respective trichimeric recipient. Peripheral blood lymphocytes from each kidney donor were then used to sensitize the alternate marrow donor. The trichimeric recipients were given donor lymphocyte infusions (DLIs) from the sensitized dogs and monitored for chimerism, graft-versus-host disease (GVHD), and kidney rejection. After DLI, we observed both prompt rejection of the transplanted marrow and donor kidney and disappearance of corresponding hematopoietic chimerism. Presumably due to shared minor histocompatibility antigens, host chimerism also disappeared, and GVHD in skin, gut, and liver developed. The native kidneys, although exhibiting lymphocytic infiltration, remained functionally normal. This study demonstrates that under certain experimental conditions, the kidney--an organ ordinarily not involved in graft-versus-host reactions--can be targeted by sensitized donor lymphocytes
Global Kidney Exchange Should Expand Wisely.
We read with great interest and appreciation the careful consideration and analysis by Ambagtsheer et al. of the most critical ethical objections to Global Kidney Exchange (GKE). Ambagtsheer et al. conclude that implementation of GKE is a means to increase access to transplantation ethically and effectively
Forward pi^0 Production and Associated Transverse Energy Flow in Deep-Inelastic Scattering at HERA
Deep-inelastic positron-proton interactions at low values of Bjorken-x down
to x \approx 4.10^-5 which give rise to high transverse momentum pi^0 mesons
are studied with the H1 experiment at HERA. The inclusive cross section for
pi^0 mesons produced at small angles with respect to the proton remnant (the
forward region) is presented as a function of the transverse momentum and
energy of the pi^0 and of the four-momentum transfer Q^2 and Bjorken-x.
Measurements are also presented of the transverse energy flow in events
containing a forward pi^0 meson. Hadronic final state calculations based on QCD
models implementing different parton evolution schemes are confronted with the
data.Comment: 27 pages, 8 figures and 3 table
Performance of the CMS Cathode Strip Chambers with Cosmic Rays
The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device
in the CMS endcaps. Their performance has been evaluated using data taken
during a cosmic ray run in fall 2008. Measured noise levels are low, with the
number of noisy channels well below 1%. Coordinate resolution was measured for
all types of chambers, and fall in the range 47 microns to 243 microns. The
efficiencies for local charged track triggers, for hit and for segments
reconstruction were measured, and are above 99%. The timing resolution per
layer is approximately 5 ns
Performance and Operation of the CMS Electromagnetic Calorimeter
The operation and general performance of the CMS electromagnetic calorimeter
using cosmic-ray muons are described. These muons were recorded after the
closure of the CMS detector in late 2008. The calorimeter is made of lead
tungstate crystals and the overall status of the 75848 channels corresponding
to the barrel and endcap detectors is reported. The stability of crucial
operational parameters, such as high voltage, temperature and electronic noise,
is summarised and the performance of the light monitoring system is presented
Capability driven development: an approach to designing digital enterprises
The final publication is available at Springer via http://dx.doi.org/10.1007/s12599-014-0362-0[EN] The need for organizations to operate in changing environments is addressed by proposing an approach that integrates organizational development with information system (IS) development taking into account changes in the application context of the solution. This is referred to as Capability Driven Development (CDD). A meta-model representing business and IS designs consisting of goals, key performance indicators, capabilities, context and capability delivery patterns, is being proposed. The use of the meta-model is validated in three industrial case studies as part of an ongoing collaboration project, whereas one case is presented in the paper. Issues related to the use of the CDD approach, namely, CDD methodology and tool support are also discussed.This work has been partially supported by the EU-FP7 funded project no: 611351 CaaS - Capability as a Service in Digital Enterprises.Berzisa, S.; Bravos, G.; Cardona Gonzalez, T.; Czubayko, U.; EspaĂąa, S.; Grabis, J.; Henkel, M.... (2015). Capability driven development: an approach to designing digital enterprises. Business and Information Systems Engineering. 57(1):15-25. https://doi.org/10.1007/s12599-014-0362-0S1525571ArchiMate (2013) An enterprise modeling language from the Open Group. http://www.opengroup.org/archimate/ . Accessed 3 Dec 2014Asadi M, Ramsin R (2008) MDA-based methodologies: an analytical survey. In: Proceedings Model driven architecture â foundations and applications (ECMDA-FA 2008), LNCS 5095, pp 419â431Barney JB (1991) Firm resources and sustained competitive advantage. J Manag 17(1):99â120BÄrziĹĄa S, Bravos G, Gonzalez Cardona T, Czubayko U, EspaĂąa S, Grabis J, Henke lM, Jokste L, Kampars J, Koc H, Kuhr J, Llorca C, Loucopoulos P, Juanes Pascua lR, Sandkuh lK, Simic H, Stirna J, Zdravkovic J (2014) Deliverable 1.4: Requirements specification for CDD, CaaS â capability as a service for digital enterprises. FP7 project no 611351, Riga Technical University, Latvia. Submitted for reviewBubenko JA Jr, Persson A, Stirna J (2001) User guide of the knowledge management approach using enterprise knowledge patterns. Deliverable D3, IST programme project hypermedia and pattern based knowledge management for smart organisations. project no. IST-2000-28401, Royal Institute of Technology, SwedenBriand LC, Yue T, Labiche Y (2011) A systematic review of transformation approaches between user requirements and analysis models. Requir Eng 16:75â99De Kinderen S, Gordijn J, Akkermans H (2009) Reasoning about customer needs in multi-supplier ICT service bundles using decision models. In: Proceedings 11th international conference on enterprise information systems (ICEIS 2009), pp 131â136Deloitte (2009) Cloud computing: forecasting change. Deloitte Consulting, New York. http://public.deloitte.no/dokumenter/2_Cloud_Computing%5B1%5D.pdf . Accessed 3 Dec 2014Dey A (2001) Understanding and using context. Pers Ubiquitous Comput 5(1):4â7Gamma E, Helm R, Johnson R, Vlissides J (1995) Design patterns: elements of reusable object-oriented software architecture. Addison-Wesley, BostonGomes D, Gonçalves JM, Santos R, Aguiar R (2010) XMPP based context management architecture. In: Proceedings GLOBECOM workshop, IEEE, pp 1372â1377GonzĂĄlez A, EspaĂąa S, Ruiz M, Pastor Ă (2011) Systematic derivation of class diagrams from communication-oriented business process models. In: 12th working conference on business process modeling, development, and support (BPMDSâ11). Springer LNBIP 81, pp 246â260Henkel M, Stirna J (2010) Pondering on the key functionality of model driven development tools: the case of mendix. In: Forbrig P, GĂźnther H (eds) Proceedings business informatics research (BIR 2010), Springer LNBIP 64, pp 146â160Hervas R, Bravo J, Fontecha J (2010) A context model based on ontological languages â a proposal for information visualisation. J Univers Comput Sci 16(12):1539â1555Jarke M, Loucopoulos P, Lyytinen K, Mylopoulos J, Robinson W (2011) The brave new world of design requirements. Information Syst 36(7):992â1008Kaplan RS, Norton DP (2004) Strategy maps: converting intangible assets into tangible outcomes. Harvard Business School Press, BostonKleppe A, Warmer J, Bast W (2013) MDA explained. Addison-Wesley, BostonLoniewski G, Insfran E, Abrahao L (2010) A systematic review of the use of requirements engineering techniques in model-driven development. In: Proceedings model driven engineering languages and systems (MODELS 2010), Part II, LNCS 6395, pp 213â227Mohagheghi P, Dehlen V (2008) Where is the proof? - a review of experiences from applying MDE in industry. In: Proceedings model driven architecture â foundations and applications (ECMDA-FA 2008). LNCS 5095. Springer, Heidelberg, pp 432â443Nilsson AG, Tolis C, Nellborn C (eds) (1999) Perspectives on business modelling: understanding and changing organisations. Springer, HeidelbergOASIS (2011) Reference architecture foundation for service oriented architecture version 1.0, committee specification draft 03/public review draft 02 06 July 2011. http://docs.oasis-open.org/soa-rm/soa-ra/v1.0/soa-ra.pdf . Accessed 3 Dec 2014OMG (2011a) UML superstructure. http://www.omg.org/spec/UML/2.4.1/ . Accessed 3 Dec 2014OMG (2011b) Business process model and notation. http://www.omg.org/spec/BPMN/2.0/ . Accessed 3 Dec 2014Osterwalder A, Pigneur Y (2003) Modeling value propositions in e-business. Proc 5th international conference on electronic commerce (ICEC 2003). ACM Conference Proceedings Series 50Papazoglou MP, Yang J (2002) Design methodology for web services and business processes. In: Proceedings 3rd international workshop on technologies for e-services (TES 03). LNCS 2444. Springer, Heidelberg, pp 54â64Pastor O, Giachetti G (2010) Linking goal-oriented requirements and model-driven development. In: Intentional perspectives on information systems engineering. Springer, Heidelberg, pp 257â276Porter ME (1985) Competitive advantage: creating and sustaining superior performance. Free Press, New YorkRuiz M, Costal D, EspaĂąa S, Franch X, Pastor Ă (2014) Integrating the goal and business process perspectives in information system analysis. In: 26th International Conference on Advanced Information Systems Engineering (CAiSE 2014). LNCS 8484. Springer, Heidelberg, pp 332â346Sheng Q, Yu J, Dustar S (eds) (2010) Enabling context-aware web services: methods, architectures, and technologies. Chapman & Hall/CRC, Boca RatonSmanchat S, Ling S, Indrawan M (2008) A survey on context-aware workflow adaptations. In: Proceedings 6th international conference on advances in mobile computing and multimedia (MoMM 2008), New York, pp 414â417Stirna J, Grabis J, Henkel M, Zdravkovic J (2012) Capability driven development â an approach to support evolving organizations. In: The practice of enterprise modeling (PoEM 2012). LNBIP 134. Springer, Heidelberg, pp 117â131Vale S, Hammoudi S (2009) COMODE: a framework for the development of context-aware applications in the context of MDE. In: Proceedings 4th international conference on internet and web applications and services (ICIW 2009). IEEE, Venice, pp 261â266Wesenberg H (2011) Enterprise modeling in an agile world. In: Johannesson P, Krogstie J, Opdahl AL (eds) The practice of enterprise modeling (PoEM 2011). LNBIP 92. Springer, Heidelberg, pp 126â130Zdravkovic J, Stirna J, Henkel M, Grabis J (2013) Modeling business capabilities and context dependent delivery by cloud services. In: Proceedings advanced information systems engineering (CAiSE 2013). LNCS 7908. Springer, Heidelberg, pp 369â38
Calibration of the CMS Drift Tube Chambers and Measurement of the Drift Velocity with Cosmic Rays
Peer reviewe
Measurement of the prompt J/psi and psi(2S) polarizations in pp collisions at sqrt(s) = 7 TeV
The polarizations of prompt J/psi and psi(2S) mesons are measured in proton-proton collisions at sqrt(s) = 7 TeV, using a dimuon data sample collected by the CMS experiment at the LHC, corresponding to an integrated luminosity of 4.9 inverse femtobarns. The prompt J/psi and psi(2S) polarization parameters lambda[theta], lambda[phi], and lambda[theta, phi], as well as the frame-invariant quantity lambda(tilde), are measured from the dimuon decay angular distributions in three different polarization frames. The J/psi results are obtained in the transverse momentum range 14 < pt < 70 GeV, in the rapidity intervals abs(y) < 0.6 and 0.6 < abs(y) < 1.2. The corresponding psi(2S) results cover 14 < pt < 50 GeV and include a third rapidity bin, 1.2 < abs(y) < 1.5. No evidence of large transverse or longitudinal polarizations is seen in these kinematic regions, which extend much beyond those previously explored
- âŚ