64 research outputs found

    Heavy quarkonium: progress, puzzles, and opportunities

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    A golden age for heavy quarkonium physics dawned a decade ago, initiated by the confluence of exciting advances in quantum chromodynamics (QCD) and an explosion of related experimental activity. The early years of this period were chronicled in the Quarkonium Working Group (QWG) CERN Yellow Report (YR) in 2004, which presented a comprehensive review of the status of the field at that time and provided specific recommendations for further progress. However, the broad spectrum of subsequent breakthroughs, surprises, and continuing puzzles could only be partially anticipated. Since the release of the YR, the BESII program concluded only to give birth to BESIII; the BB-factories and CLEO-c flourished; quarkonium production and polarization measurements at HERA and the Tevatron matured; and heavy-ion collisions at RHIC have opened a window on the deconfinement regime. All these experiments leave legacies of quality, precision, and unsolved mysteries for quarkonium physics, and therefore beg for continuing investigations. The plethora of newly-found quarkonium-like states unleashed a flood of theoretical investigations into new forms of matter such as quark-gluon hybrids, mesonic molecules, and tetraquarks. Measurements of the spectroscopy, decays, production, and in-medium behavior of c\bar{c}, b\bar{b}, and b\bar{c} bound states have been shown to validate some theoretical approaches to QCD and highlight lack of quantitative success for others. The intriguing details of quarkonium suppression in heavy-ion collisions that have emerged from RHIC have elevated the importance of separating hot- and cold-nuclear-matter effects in quark-gluon plasma studies. This review systematically addresses all these matters and concludes by prioritizing directions for ongoing and future efforts.Comment: 182 pages, 112 figures. Editors: N. Brambilla, S. Eidelman, B. K. Heltsley, R. Vogt. Section Coordinators: G. T. Bodwin, E. Eichten, A. D. Frawley, A. B. Meyer, R. E. Mitchell, V. Papadimitriou, P. Petreczky, A. A. Petrov, P. Robbe, A. Vair

    Highly-parallelized simulation of a pixelated LArTPC on a GPU

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    The rapid development of general-purpose computing on graphics processing units (GPGPU) is allowing the implementation of highly-parallelized Monte Carlo simulation chains for particle physics experiments. This technique is particularly suitable for the simulation of a pixelated charge readout for time projection chambers, given the large number of channels that this technology employs. Here we present the first implementation of a full microphysical simulator of a liquid argon time projection chamber (LArTPC) equipped with light readout and pixelated charge readout, developed for the DUNE Near Detector. The software is implemented with an end-to-end set of GPU-optimized algorithms. The algorithms have been written in Python and translated into CUDA kernels using Numba, a just-in-time compiler for a subset of Python and NumPy instructions. The GPU implementation achieves a speed up of four orders of magnitude compared with the equivalent CPU version. The simulation of the current induced on 10^3 pixels takes around 1 ms on the GPU, compared with approximately 10 s on the CPU. The results of the simulation are compared against data from a pixel-readout LArTPC prototype

    Facial Recognition Techniques Applied to the Automated Registration of Patients in the Emergency Treatment of Head Injuries

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    This article was accepted for publication in the journal Proceedings of the Institution of Mechanical Engineers Part H- Journal of Engineering in Medicine. The definitive version is available at: http://dx.doi.org/10.1243/09544119JEIM839This paper describes the development of a registration framework for image-guided solutions to the automation of certain routine neurosurgical procedures. The registration process aligns the pose of the patient in the preoperative space to that of the intra-operative space. CT images are used in the pre-operative (planning) stage, whilst white light (TV camera) images are used to capture the intra-operative pose. Craniofacial landmarks, rather than artificial markers, are used as the registration basis for the alignment. To further synergy between the user and the image-guided system, automated methods for extraction of these landmarks have been developed. The results obtained from the application of a Polynomial Neural Network (PNN) classifier based on Gabor features for the detection and localisation of the selected craniofacial landmarks, namely the ear tragus and eye corners in the white light modality are presented. The robustness of the classifier to variations in intensity and noise is analysed. The results show that such a classifier gives good performance for the extraction of craniofacial landmarks

    Tratamento térmico de lodo anaeróbio com utilização do biogás gerado em reatores UASB: avaliação da autossustentabilidade do sistema e do efeito sobre a higienização e a desidratação do lodo Thermal treatment of anaerobic sludge utilizing biogas produced in UASB reactors: evaluation of system self-sustainability and the effect on sludge hygienization and dehydration

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    O presente trabalho objetiva avaliar a eficiência do biogás gerado em reatores UASB como fonte de energia para higienização térmica do lodo excedente, atentando-se ainda para a autossustentabilidade do sistema e para a avaliação do desaguamento do lodo tratado termicamente. Foi desenvolvido em um aparato experimental em escala de demonstração constituído de reator UASB, reservatório de biogás, reator térmico e leitos de secagem. A autossustentabilidade foi verificada por meio de balanço térmico teórico e de testes experimentais de higienização térmica. Estes testes indicaram que o aproveitamento da energia térmica do biogás foi suficiente para aquecer o lodo em temperaturas de 55 a 65ºC, durante três a cinco horas, possibilitando a completa eliminação de ovos viáveis de helmintos. No entanto, o processo de desidratação se mostrou muito mais difícil para o lodo tratado termicamente.<br>The objective of this research was to determine how effectively biogas produced in UASB reactors could be used as a source of heat for the thermal hygienization of excess anaerobic sludge, whether the system can operate on a self-sustained basis and how the dehydration of the thermally treated sludge behave. The experiments were conducted in a demonstration-scale setup comprising UASB reactor, biogas holder, thermal reactor and sludge drying beds. The self-sustainability of the system was evaluated by the systemâ€TMs theoretical thermal balance and by experimental hygienization tests. These tests indicated that the recovery of thermal energy from the biogas was sufficient to heat the sludge at temperatures in the range of 55 to 65ºC, for three to five hours, allowing the complete elimination of viable helminth eggs. However, the dehydration process showed to be much more difficult for the thermally treated sludge

    Does smoking status influence the prognosis of bladder cancer? A systematic review.

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    OBJECTIVE: To summarize, in a systematic review, the evidence for the effect of stopping smoking on recurrence, cancer-specific and all cause-mortality among smokers with newly diagnosed bladder cancer. MATERIALS AND METHODS: Two electronic databases and the reference lists of identified primary studies and reviews were searched. Studies were included if a hazard ratio and its confidence intervals could be extracted. A predefined set of study characteristics was extracted which defined whether studies were giving valid prognostic data on the effects of smoking in reasonably homogenous cohorts. The results of studies were synthesized qualitatively. RESULTS: Fifteen relevant studies were identified; former and current smokers were combined in many studies. Many studies produced information on prognosis that was confounded by the mixing of incident and prevalent cases. Only three studies examined the influence of smoking on prognosis in only incident cases, most of whom had superficial disease. Of these, only one was of high quality. These three studies and the other 12 showed suggestive evidence that continued smoking or a lifetime of smoking constitutes a moderate risk factor for recurrence and death, and that stopping smoking could favourably change this. However, the evidence base for this is weak because of the methodological shortcomings and because most studies' results were not statistically significant. A life-table model showed that if stopping smoking altered the prognosis, the size of the benefit would be clinically worthwhile. CONCLUSION: There is suggestive evidence that stopping smoking might favourably alter the course of bladder cancer, but this is insufficient for clinicians to inform patients that doing so will improve their prognosis, and for providing specialized services to assist in stopping smoking to patients with bladder cancer

    Post-Soviet transformation of Lithuanian state cultural policy: the meanings of democratisation

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    Straipsnyje pateikiama kultūros politikos demokratizacijos proceso Lietuvoje bendra apžvalga. Ji parengta analizuojant atvirų diskusijų apie demokratiją argumentus ir Lietuvos politinius dokumentus (1988-2011 m.). Pokyčių pradžioje (1988-1992 m.) demokratizacija įsivaizduota kaip politinių institucijų administracinė decentralizacija, ypatingai Kultūros ministerijos, ir demokratijos principų, pvz., žodžio laisvės ir kultūrinės savivaldos, įdiegimas. Daugiau esminių demokratizacijos reikšmių atskleista diskusijose apie etninę įvairovę ir socialinę lygybę. Tyrimas išryškino įtampą tarp aukštosios ir pop kultūros vertybių bei lietuvių ir tautinių mažumų tautinės etninės kultūros vieningos sampratos. Vėliau, sumažėjus etninės dimensijos reikšmei, kultūros politikos demokratizacija konceptualizuota sąveikoje su žinių ekonomika, reikalavusia keisti ankstyvąją post-sovietinę konfrontaciją tarp kultūros ir jos ekonomikos.This paper presents a general overview of the process of the democratisation of cultural policy in Lithuania by exploring explicit arguments about democratisation in debates and policy documents in Lithuania (1988-2011). At the early stage of transformation (1988-1992), democratisation was envisaged as the administrative decentralisation of political institutions, particularly the Ministry of Culture, and as the introduction of democratic principles, such as freedom of speech and cultural self-regulation. More substantial meanings of democratisation were articulated in debates about ethnic diversity and social equality. The study reveals tensions between the values of high culture and pop culture and the unitary notion of Lithuanian national ethnic culture and the cultures of national minorities. At a later stage, the salience of the ethnic dimension decreased when the democratisation of cultural policy was conceptualised in relation to the knowledge economy, which required revision of the early post- Soviet confrontation between culture and its economic use
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