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UCL University College London Eprints (372,854 recursos)

UCL Eprints collects the work of UCL researchers and makes it freely available over the web, helping the worldwide scholarly community to discover UCL research. Institutional repositories like UCL Eprints complement the traditional academic publishing and scholarly communications processes. They raise the visibility of research and help to maximise its impact. UCL researchers are encouraged to deposit a copy of each journal article, conference paper, working paper, and any other research output, in the UCL Eprints at the earliest opportunity, ensuring that their research reaches as wide an audience as possible.

Mostrando recursos 61 - 80 de 376,678

  1. RESTRICTIVE VERSUS LIBERAL BLOOD TRANSFUSION FOR ACUTE UPPER GASTROINTESTINAL BLEEDING: CLUSTER RANDOMISED FEASIBILITY TRIAL

    Jairath, V; Kahan, B; Gray, A; Dore, C; Palmer, K; Travis, S; Logan, R; Walsh, T; Murphy, M; Investigators, TRIGGER

  2. The Collective Responsibility of Democratic Publics

    PASTERNAK, AVIA

  3. Undertaking the tokeneer challenge in event-b.

    Rivera, V; Bhattacharya, S; Cataño, N

  4. Quantum reverse hypercontractivity

    Cubitt, T; Kastoryano, M; Montanaro, A; Temme, K

  5. Rapid mixing and stability of quantum dissipative systems

    Lucia, A; Cubitt, TS; Michalakis, S; Pérez-García, D
    © 2015 American Physical Society.The physics of many materials is modeled by quantum many-body systems with local interactions. If the model of the system is sensitive to noise from the environment, or small perturbations to the original interactions, it will not properly model the robustness of the real physical system it aims to describe, or be useful when engineering novel systems for quantum information processing. We show that local observables and correlation functions of local Liouvillians are stable to local perturbations if the dynamics is rapidly mixing and has a unique fixed point. No other condition is required.

  6. Bounds on entanglement assisted source-channel coding via the lovász number and its variants

    Cubitt, T; Mancinska, L; Roberson, D; Severini, S; Stahlke, D; Winter, A
    We study zero-error entanglement assisted source-channel coding (communication in the presence of side information). Adapting a technique of Beigi, we show that such coding requires existence of a set of vectors satisfying orthogonality conditions related to suitably defined graphs G and H. Such vectors exist if and only if (G) ≤ (H) where represents the Lovász number. We also obtain similar inequalities for the related Schrijver - and Szegedy + numbers. These inequalities reproduce several known bounds and also lead to new results. We provide a lower bound on the entanglement assisted cost rate. We show that the entanglement assisted...

  7. Complexity classification of local hamiltonian problems

    Cubitt, TS; Montanaro, A
    © 2014 IEEE.The calculation of ground-state energies of physical systems can be formalised as the k-local Hamiltonian problem, which is the natural quantum analogue of classical constraint satisfaction problems. One way of making the problem more physically meaningful is to restrict the Hamiltonian in question by picking its terms from a fixed set S. Examples of such special cases are the Heisenberg and Ising models from condensed-matter physics. In this work we characterise the complexity of this problem for all 2-local qubit Hamiltonians. Depending on the subset S, the problem falls into one of the following categories: in P, NP-complete,...

  8. Evaluation of ionic liquids as dispersed phase during the production of lactones with E-coli in a three phase partitioning bioreactor

    Melgarejo-Torres, R; Castillo-Araiza, CO; Lopez-Ordaz, P; Calleja-Castaneda, NV; Cano-Velasco, JL; Camacho-Ruiz, RM; Lye, GJ; Huerta-Ochoa, S

  9. Margaret thatcher and the decline of class politics

    Lawrence, J; Sutcliffe-Braithwaite, F
    © Cambridge University Press 2012.Ditching the class baggage When Margaret Thatcher became leader of the Conservative Party in 1975, British public discourse remained heavily stamped by the impress of social class. Indeed, arguably ‘languages of class’ were more ubiquitous in the 1970s than they had been a decade earlier. In the 1960s, Wilson’s shrewd campaign against the Conservatives’ ‘thirteen wasted years’ had traded heavily on a classless populism. In the anti-establishment rhetoric of Wilson’s proposed technocratic revolution, the rule of the privileged ‘classes’ was to give way to a new meritocracy capable of reversing Britain’s relative economic decline. Reworking earlier...

  10. Factors limiting the number of independent cultural traits that can bemaintained in a population

    Fogarty, L; Wakano, JY; Feldman, M; Aoki, K
    © Springer Japan 2015.We obtain the theoretically expected number of independent cultural traits at equilibrium in a population where one of four modes of social learning—random oblique, best-of-K, success bias, or one-to-many—is practiced by its members. Cultural traits can be classified as simple or complex, depending on the ease or difficulty of acquisition by social learning and innovation. The number of simple cultural traits may saturate as population size increases, in which case a statistical association between the two variables is not predicted. At smaller population sizes, there is a major effect of the mode of social learning on the...

  11. Homo antecessor: The state of the art eighteen years later

    Bermúdez-de-Castro, JM; Martinón-Torres, M; Martín-Francés, L; Modesto-Mata, M; Martínez-de-Pinillos, M; García, C; Carbonell, E
    © 2015 Elsevier Ltd and INQUA.It is eighteen years since the human fossils recovered from the TD6 level of the Gran Dolina cave site, in Sierra de Atapuerca (Burgos, northern Spain) were assigned to a new hominin species, Homo antecessor. This review summarizes the main results obtained from the study of these fossils during this period. The increase of the African and Eurasian fossil record, as well as the application of new methodological approaches, has led to competing interpretations about its hypothetical phylogenetic position and possible evolutionary scenarios. At present, we can argue that this species is defined by a...

  12. Evolutionary interpretation of the modern human-like facial morphology of the Atapuerca Gran Dolina-TD6 hominins

    Bermúdez De Castro, JM; Martinón-Torres, M
    © 2014 The Anthropological Society of Nippon.The Early Pleistocene human fossil remains recovered from the TD6 lithostratigraphic unit of the Gran Dolina cave site in the Sierra de Atapuerca, northern Spain, show a mosaic of primitive and derived features. Among the latter, the modern human-like midfacial topography, as well as several synapomorphies shared with some European Middle Pleistocene hominin and Neanderthals, represents a challenge for the phylogenetic interpretation of Homo antecessor. Using an ontogenetic approach of the maxilla ATD6-69, Freidline et al. (Journal of Human Evolution, 65: 404–423 (2013)) have confirmed previous observations that H. antecessor adults had a set...

  13. The Atapuerca sites and their contribution to the knowledge of human evolution in Europe

    De Castro, JMB; Martinon-Torres, M; Carbonell, E; Sarmiento, S; Rosas, A; Van der Made, J; Lozano, M
    Over the last two decades, the Pleistocene sites of the Sierra de Atapuerca (Spain) have provided two extraordinary assemblages of hominin fossils that have helped refine the evolutionary story of the genus Homo in Europe. The TD6 level of the Gran Dolina site has yielded about one hundred remains belonging to a minimum of six individuals of the species Homo antecessor. These fossils, dated to the end of the Lower Pleistocene (800 kyr), provide the earliest evidence of hominin presence in Western Europe. The origin of these hominins is unknown, but they may represent a speciation event from Homo ergaster/Homo...

  14. Fluorescence lifetime imaging (Flim): Basic concepts and recent applications

    Suhling, K; Hirvonen, LM; Levitt, JA; Chung, PH; Tregido, C; Marois, AL; Rusakov, DA; Zheng, K; Ameer-Beg, S; Poland, S; Coelho, S; Dimble, R
    ©Springer International Publishing Switzerland 2015.Fluorescence lifetime imaging (FLIM) is a key fluorescence microscopy technique to map the environment and interaction of fluorescent probes. It can report on photo physical events that are difficult or impossible to observe by fluorescence intensity imaging, because FLIM is independent of the local fluorophore concentration and excitation intensity. A FLIM application relevant for biology concerns the identification of FRET to study protein interactions and conformational changes, and FLIM can also be used to image viscosity.

  15. Modal shift of passenger transport in a TIMES model: Application to Ireland and California

    Daly, HE; Ramea, K; Chiodi, A; Yeh, S; Gargiulo, M; Gallachóir, B
    © Springer International Publishing Switzerland 2015.Climate change mitigation clearly requires a focus on transport that should include improved representation of travel behaviour change in addition to increased vehicle efficiency and low-carbon fuels. Energy system models focus however on technology and fuel switching and tend to poorly incorporate travel behaviour. Conversely, transport demand modelling generally fails to address energy and climate policy trade-offs. This chapter seeks to make energy systems analysis more holistic by introducing modal choice within passenger transport in a TIMES model, to allow trade-offs between behaviour and technology choices explicit. Travel demand in TIMES models is typically exogenous-no...

  16. Streptozocin-based chemotherapy: Still a standard of care for neuroendocrine tumours?

    Khalique, S; Meyer, T
    © Springer-Verlag France 2014.Streptozocin (STZ)-based chemotherapy has been used for over 40 years in the treatment for neuroendocrine tumours (NETs); however, there have been few randomized trials, and STZ remains unlicensed in many countries. With the recent approval of sunitinib and everolimus for pancreatic NETs (PNETs), and the emergence of a more stratified approach to cancer therapy, it is timely to reevaluate the role of STZ for NETs. Here, we review the evidence base for STZbased chemotherapy, the toxicity associated with treatment and the position of STZ in the current therapeutic algorithm. Although there are no trials comparing chemotherapy with...

  17. The public impact of impacts: How the media play in the mass extinction debates

    Miller, S
    © 2014 The Geological Society of America. All rights reserved."Mass media" presentations of the dinosaurs and their co-inhabitants have been around for some 200 years. The question of what exterminated the dinosaurs and allowed mammals to take their leading place on Earth has a similarly lengthy history in the scientific arena and in public. However, there are amazingly few communication studies of the debates around mass extinctions and impacts. Those that do exist have picked up on the fact that these debates involve scientists from several disciplines, scientists who are often unused to reading each other's research. Under these circumstances,...

  18. The H+3 latitudinal profile of Saturn

    Stallard, T; Miller, S; Ballester, GE; Rego, D; Joseph, RD; Trafton, LM
    We present an H+3 latitudinal profile of Saturn, obtained in 1998 October using the CSHELL spectrometer on the NASA Infrared Telescope Facility. The profile, measured at 3.953 μm, shows that the majority of the emission is concentrated in the auroral ovals, making Saturn similar to Jupiter and different from Uranus. The spatial resolution is sufficient to resolve the southern auroral oval, currently fully displayed around the south pole, into two peaks separated by 1″.2. At the time of the observations reported here, the emission flux in the H+3 line is 8.3 (± 1.7) × 10-18 W m-2 for the intensity...

  19. Desegmentation of Ozurdex implant in vitreous cavity: report of two cases

    Agrawal, R; Fernandez-Sanz, G; Bala, S; Addison, PKF

  20. Teaching evolution in schools: A matter of controversy?

    Levinson, R
    © 2015 Sense Publishers. All rights reserved.In a clip from YouTube Richard Dawkins says ‘Who cares about creationists? They don’t know anything’. Like Dawkins, I agree that creationism has nothing to offer as an explanation for the origins and diversity of life on this planet. Although I am not a professional biologist everything I have read and heard, including Darwin’s On the origin of species, has so far convinced me that evolution is a fact, and that while there are different explanations to account for evolution none have to date undermined it.

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