402 research outputs found

    University of Amsterdam at TREC 2019:Complex Answer Retrieval Track

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    This paper documents the University of Amsterdam’s participation in the TREC 2019 Complex Answer Retrieval Track. This is the ïŹrst year we actively participate in TREC CAR, attracted by the introduction to the limited “budget” of 20 passages per heading in the outline. We conducted initial exploratory experiments on making each heading contain a unique set of passages within the outline, and even do this hierarchical for each subtree and main title/article level, hence remove any redundancy between passages for different “queries” within the same title. We experimented with top-down and bottom-up ïŹltering approaches. At the time of writing we are still in the process of analyzing the results. Some initial observations are the following. First, the restriction makes the task very challenging, as assigning any passage to the right heading in the outline is highly non-trivial. Qualitative analysis shows that our simple heuristics often make a different decision than the editorial judges on the heading under which a passage relevant to the title’s topic is assigned. Second, the fraction of judged and relevant passages per individual query or leave node is very small, making it hard to draw any deïŹnite conclusions on our experiments, and also resulting in a too small recall base to evaluate our non-pooled runs in a meaningful way. Third, when aggregating all qrels and runs to the title level, there is reasonable eïŹ€ectiveness of the underlying BM25 rankings, showing that the underlying passage ranking is not unreasonable, and that the hard and interesting problem is in the exact assignment of passages to the “right” headings

    University of Amsterdam at TREC 2019:Complex Answer Retrieval Track

    Get PDF
    This paper documents the University of Amsterdam’s participation in the TREC 2019 Complex Answer Retrieval Track. This is the ïŹrst year we actively participate in TREC CAR, attracted by the introduction to the limited “budget” of 20 passages per heading in the outline. We conducted initial exploratory experiments on making each heading contain a unique set of passages within the outline, and even do this hierarchical for each subtree and main title/article level, hence remove any redundancy between passages for different “queries” within the same title. We experimented with top-down and bottom-up ïŹltering approaches. At the time of writing we are still in the process of analyzing the results. Some initial observations are the following. First, the restriction makes the task very challenging, as assigning any passage to the right heading in the outline is highly non-trivial. Qualitative analysis shows that our simple heuristics often make a different decision than the editorial judges on the heading under which a passage relevant to the title’s topic is assigned. Second, the fraction of judged and relevant passages per individual query or leave node is very small, making it hard to draw any deïŹnite conclusions on our experiments, and also resulting in a too small recall base to evaluate our non-pooled runs in a meaningful way. Third, when aggregating all qrels and runs to the title level, there is reasonable eïŹ€ectiveness of the underlying BM25 rankings, showing that the underlying passage ranking is not unreasonable, and that the hard and interesting problem is in the exact assignment of passages to the “right” headings

    Jockeying for position: the construction of masculine identities

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    In this paper we examine the construction of masculine identities within a real-life social situation. Using data from an extensive series of interviews with small groups of sixth-form (17-18-year-old) students attending a UK-based, single-sex independent school, the analysis looks at the action orientation of different constructions of identity. More specifically, it focuses upon how the identity talk of one particular group of students were oriented towards managing their subordinate status within the school. In a number of instances the identity of the `new man' was adopted as a strategy of resistance. However, it was found that the more common strategy involved buying back into values embodied within a more traditional definition of masculinity

    Validation of distinct type 2 diabetes clusters and their association with diabetes complications in the DEVOTE, LEADER and SUSTAIN-6 cardiovascular outcomes trials

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    Aims: To validate the clusters of Swedish individuals with recent-onset diabetes at differential risk of complications, which were identified in a previous study, in three global populations with long-standing type 2 diabetes (T2D) who were at high cardiovascular risk, and to test for differences in the risk of major diabetes complications and survival endpoints. Materials and methods: We assigned participants from recent global outcomes trials (DEVOTE [n = 7637], LEADER [n = 9340] and SUSTAIN-6 [n = 3297]) to the previously defined clusters according to age at diabetes diagnosis, baseline glycated haemoglobin (HbA1c) and body mass index (BMI). Outcomes were assessed using Kaplan–Meier analysis and log-rank tests. Results: The T2D clusters were consistently replicated across the three trial cohorts. The risk of major adverse cardiovascular events and cardiovascular death differed significantly, in all trials, across clusters over a median follow-up duration of 2.0, 3.8 and 2.1 years, respectively, and was highest for the cluster of participants with high HbA1c and low BMI (P < 0.05 in DEVOTE and LEADER). In LEADER and SUSTAIN-6, the risk of nephropathy differed across clusters (P < 0.0001 and P = 0.003, respectively). The risk of severe hypoglycaemia differed in DEVOTE (P = 0.006). Conclusions: Previously identified clusters can be replicated in three geographically diverse cohorts of long-standing T2D and are associated with cluster-specific risk profiles for additional clinical and survival outcomes, providing further validation of the clustering methodology. The external validity and stability of clusters across cohorts provides a premise for future work to optimize the clustering approach to yield T2D subgroups with maximum predictive validity who may benefit from subtype-specific treatment paradigms

    Centrality Dependence of the High p_T Charged Hadron Suppression in Au+Au collisions at sqrt(s_NN) = 130 GeV

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    PHENIX has measured the centrality dependence of charged hadron p_T spectra from central Au+Au collisions at sqrt(s_NN)=130 GeV. The truncated mean p_T decreases with centrality for p_T > 2 GeV/c, indicating an apparent reduction of the contribution from hard scattering to high p_T hadron production. For central collisions the yield at high p_T is shown to be suppressed compared to binary nucleon-nucleon collision scaling of p+p data. This suppression is monotonically increasing with centrality, but most of the change occurs below 30% centrality, i.e. for collisions with less than about 140 participating nucleons. The observed p_T and centrality dependence is consistent with the particle production predicted by models including hard scattering and subsequent energy loss of the scattered partons in the dense matter created in the collisions.Comment: 7 pages text, LaTeX, 6 figures, 2 tables, 307 authors, resubmitted to Phys. Lett. B. Revised to address referee concerns. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are publicly available at http://www.phenix.bnl.gov/phenix/WWW/run/phenix/papers.htm

    The PHENIX Experiment at RHIC

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    The physics emphases of the PHENIX collaboration and the design and current status of the PHENIX detector are discussed. The plan of the collaboration for making the most effective use of the available luminosity in the first years of RHIC operation is also presented.Comment: 5 pages, 1 figure. Further details of the PHENIX physics program available at http://www.rhic.bnl.gov/phenix

    Azimuthal anisotropy and correlations in p+p, d+Au and Au+Au collisions at 200 GeV

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    We present the first measurement of directed flow (v1v_1) at RHIC. v1v_1 is found to be consistent with zero at pseudorapidities η\eta from -1.2 to 1.2, then rises to the level of a couple of percent over the range 2.4<∣η∣<42.4 < |\eta| < 4. The latter observation is similar to data from NA49 if the SPS rapidities are shifted by the difference in beam rapidity between RHIC and SPS. Back-to-back jets emitted out-of-plane are found to be suppressed more if compared to those emitted in-plane, which is consistent with {\it jet quenching}. Using the scalar product method, we systematically compared azimuthal correlations from p+p, d+Au and Au+Au collisions. Flow and non-flow from these three different collision systems are discussed.Comment: Quark Matter 2004 proceeding, 4 pages, 3 figure

    Azimuthal anisotropy: the higher harmonics

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    We report the first observations of the fourth harmonic (v_4) in the azimuthal distribution of particles at RHIC. The measurement was done taking advantage of the large elliptic flow generated at RHIC. The integrated v_4 is about a factor of 10 smaller than v_2. For the sixth (v_6) and eighth (v_8) harmonics upper limits on the magnitudes are reported.Comment: 4 pages, 6 figures, contribution to the Quark Matter 2004 proceeding

    All-optical switching and strong coupling using tunable whispering-gallery-mode microresonators

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    We review our recent work on tunable, ultrahigh quality factor whispering-gallery-mode bottle microresonators and highlight their applications in nonlinear optics and in quantum optics experiments. Our resonators combine ultra-high quality factors of up to Q = 3.6 \times 10^8, a small mode volume, and near-lossless fiber coupling, with a simple and customizable mode structure enabling full tunability. We study, theoretically and experimentally, nonlinear all-optical switching via the Kerr effect when the resonator is operated in an add-drop configuration. This allows us to optically route a single-wavelength cw optical signal between two fiber ports with high efficiency. Finally, we report on progress towards strong coupling of single rubidium atoms to an ultra-high Q mode of an actively stabilized bottle microresonator.Comment: 20 pages, 24 figures. Accepted for publication in Applied Physics B. Changes according to referee suggestions: minor corrections to some figures and captions, clarification of some points in the text, added references, added new paragraph with results on atom-resonator interactio
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