Comparing knowledge sources for nominal anaphora resolution

We compare two ways of obtaining lexical knowledge for antecedent selection in other-anaphora and definite noun phrase coreference. Specifically, we compare an algorithm that relies on links encoded in the manually created lexical hierarchy WordNet and an algorithm that mines corpora by means of shallow lexico-semantic patterns. As corpora we use the British National Corpus (BNC), as well as the Web, which has not been previously used for this task. Our results show that (a) the knowledge encoded in WordNet is often insufficient, especially for anaphor-antecedent relations that exploit subjective or context-dependent knowledge; (b) for other-anaphora, the Web-based method outperforms the WordNet-based method; (c) for definite NP coreference, the Web-based method yields results comparable to those obtained using WordNet over the whole dataset and outperforms the WordNet-based method on subsets of the dataset; (d) in both case studies, the BNC-based method is worse than the other methods because of data sparseness. Thus, in our studies, the Web-based method alleviated the lexical knowledge gap often encountered in anaphora resolution, and handled examples with context-dependent relations between anaphor and antecedent. Because it is inexpensive and needs no hand-modelling of lexical knowledge, it is a promising knowledge source to integrate in anaphora resolution systems

Resonance production from jet fragmentation

Short lived resonances are sensitive to the medium properties in heavy-ion collisions. Heavy hadrons have larger probability to be produced within the quark gluon plasma phase due to their short formation times. Therefore heavy mass resonances are more likely to be affected by the medium, and the identification of early produced resonances from jet fragmentation might be a viable option to study chirality. The high momentum resonances on the away-side of a triggered di-jet are likely to be the most modified by the partonic or early hadronic medium. We will discuss first results of triggered hadron-resonance correlations in Cu+Cu heavy ion collisions.Comment: Hot Quarks Colorado 2008 Proceedings, 4 pages 5 figure

Resonance Production in STAR

The recent results from resonance production in central Au+Au and p+p collisions at $\sqrt{s_{\rm NN}} =$ 200 GeV from the STAR experiment at RHIC are presented and discussed.Comment: 7 pages, proceedings 19th Winter Workshop on Nuclear Dynamics, Breckenridge, Colorado, USA, February 8-15, 200

What do we learn from Resonance Production in Heavy Ion Collisions?

Resonances with their short life time and strong coupling to the dense and hot medium are suggested as a signature of the early stage of the fireball created in a heavy ion collision \cite{rap00,lut01,lut02}. The comparison of resonances with different lifetimes and quark contents may give information about time evolution and density and temperature of during the expanding of fireball medium. Resonances in elementary reactions have been measured since 1960. Resonance production in elementary collisions compared with heavy ion collisions where we expect to create a hot and dense medium may show the direct of influence of the medium on the resonances. This paper shows a selection of the recent resonance measurements from SPS and RHIC heavy ion colliders.Comment: 10 pages, 8 figures, HotQuarks 2004 conference proceeding

Resonance production in heavy ion collisions

Recent results of resonance production from RHIC at $\sqrt{s_{\rm NN}} =$ 200 GeV and SPS at $\sqrt{s_{\rm NN}} =$ 17 GeV are presented and discussed in terms of the evolution and freeze-out conditions of a hot and dense fireball medium. Yields and spectra are compared with thermal model predictions at chemical freeze-out. Deviations in the low transverse momentum region of the resonance spectrum of the hadronic decay channel, suggest a strongly interaction hadronic phase between chemical and kinetic freeze-out. Microscopic models including resonance rescattering and regeneration are able to describe the trend of the data. The magnitude of the regeneration cross sections for different inverse decay channels are discussed. Model calculations which include elastic hadronic interactions between chemical freeze-out and thermal freeze-out based on the K(892)/K and $\Lambda$(1520)/$\Lambda$ ratios suggest a time between two freeze-outs surfaces of $\Delta \tau>$ 4 fm/c. The difference in momentum distributions and yields for the $\phi$(1020) resonance reconstructed from the leptonic and hadronic decay channels at SPS energy are discussed taking into account the impact of a hadronic phase and possible medium modifications.Comment: 8 pages, 4 figures, conference proceedings (SQM2004

Neutrophil Oxygen Radical Production by Dialysis Membranes

The ability of different dialysis membranes to activate polymorphonuclear neutrophil oxygen radical production was investigated with chemiluminescence. All the six membranes, namely cuprophan, cellulose acetate, polycarbonate, polysulphone, polyacrilonitrile and polymethylmethacrylate were able to interact with neutrophils and stimulate their oxygen radical production, the highest responses being seen with polyacrilonitrile, polymethylmethacrylate and polycarbonate. To analyse the role of complement in this interaction, fresh plasma, heat inactivated and zymosan-activated plasma were added: with fresh plasma oxygen radical production was stimulated on cuprophan, cellulose acetate and polysulphone, not modified on polycarbonate, and decreased on polyacrilonitrile and polymethylmethacrylate. With heat-inactivated plasma, the responses were decreased or abrogated on all the membranes except polycarbonate and polymethylmethacrylate, whereas with zymosanactivated plasma similar responses to fresh plasma were observed. In addition, when plasma was used to precoat the membrane, cuprophan, cellulose acetate and polysulphone disclosed an enhanced neutrophil oxidative burst, while precoated polyacrilonitrile and polymethylmethacrylate were less stimulatory than uncoated membranes. In contrast the precoating of polycarbonate did not modify oxygen radical production. These data suggest that neutrophil activation occurs by direct membrane neutrophil interaction. Plasmatic factors modulate this interaction but complement seems involved on cellulosic and polysulphone membranes only. Therefore, it appears that oxygen radicals produced from contact of neutrophils with the dialysis membrane might play an initial and/or additional role in the events occurring at the initiation of haemodialysi

Role of protein adsorption on haemodialysis-induced complement activation and neutrophil defects

The present clinical study investigated the role of protein adsorption on complement activation and neutrophil functions during in vivo haemodialysis. The parameters were measured simultaneously at the arterial and venous sites of a cuprophan (CU) dialyser with or without pretreatment with human albumin, human immunoglobulins or human total plasma proteins (PLP). Leukocyte count, complement activation (C3a des arg), oxygen radical production and chemotaxis were measured at time zero and 15 min at the arterial and venous sites of the dialyser. Leukopenia observed at both sites was prevented only with PLP treatment. Complement activation was maximal at the venous site, but was not prevented by any of the treatments. Neutrophil oxygen radical production and chemotaxis were significantly decreased only at the venous site and restored to normal with any of the three treatments. Complement activation was maximal at the venous site, but was not prevented by any of the treatments. Protein adsorption on the dialyser membrane seems to modulate the bioincompatibility parameters in a different way. Depending on the functions tested, the protein fractions have different protecting effects, indicating the multifactorial mechanism implicated in the CU haemodialysis-induced leukopenia, complement activation and neutrophil defec

Thymus transplantation for complete DiGeorge syndrome: European experience

Background: Thymus transplantation is a promising strategy for the treatment of athymic complete DiGeorge syndrome (cDGS). Methods: Twelve patients with cDGS were transplanted with allogeneic cultured thymus. Objective: To confirm and extend the results previously obtained in a single centre. Results: Two patients died of pre-existing viral infections without developing thymopoeisis and one late death occurred from autoimmune thrombocytopaenia. One infant suffered septic shock shortly after transplant resulting in graft loss and the need for a second transplant. Evidence of thymopoeisis developed from 5-6 months after transplantation in ten patients. The median (range) of circulating naïve CD4 counts (x10663 /L) were 44(11-440) and 200(5-310) at twelve and twenty-four months post-transplant and T-cell receptor excision circles were 2238 (320-8807) and 4184 (1582 -24596) per106 65 T-cells. Counts did not usually reach normal levels for age but patients were able to clear pre-existing and later acquired infections. At a median of 49 months (22-80), eight have ceased prophylactic antimicrobials and five immunoglobulin replacement. Histological confirmation of thymopoeisis was seen in seven of eleven patients undergoing biopsy of transplanted tissue including five showing full maturation through to the terminal stage of Hassall body formation. Autoimmune regulator (AIRE) expression was also demonstrated. Autoimmune complications were seen in 7/12 patients. In two, early transient autoimmune haemolysis settled after treatment and did not recur. The other five suffered ongoing autoimmune problems including: thyroiditis (3); haemolysis (1), thrombocytopaenia (4) and neutropenia (1). Conclusions: This study confirms the previous reports that thymus transplantation can reconstitute T cells in cDGS but with frequent autoimmune complications in survivors

Possible glueball production in relativistic heavy-ion collisions

Within a thermal model we estimate possible multiplicities of scalar glueballs in central Au+Au collisions at AGS, SPS, RHIC and LHC energies. For the glueball mass in the region 1.5-1.7 GeV, the model predicts on average (per event) 0.5-1.5 glueballs at RHIC and 1.5-4 glueballs at LHC energies. Possible enhancement mechanisms are discussed.Comment: 8 pages, 2 figure