Study of psi' and chi_c decays as feed-down sources of J/psi hadro-production

The interpretation of the J/psi suppression patterns observed in nuclear collisions, at CERN and RHIC, as a signature of the formation of a deconfined phase of QCD matter, requires knowing which fractions of the measured J/psi yields, in pp collisions, are due to decays of heavier charmonium states. From a detailed analysis of the available mid-rapidity charmonium hadro-production cross sections, or their ratios, we determine that the J/psi feed-down contributions from psi' and chi_c decays are, respectively, (8.1 +/- 0.3) % and (25 +/- 5) %. These proton-proton values are derived from global averages of the proton-nucleus measurements, assuming that the charmonium states are exponentially absorbed with the length of matter they traverse in the nuclear targets.Comment: 12 pages, 4 figures, 3 table

Arl13b interferes with α-tubulin acetylation

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Heavy-ion Physics at a Fixed-Target Experiment Using the LHC Proton and Lead Beams (AFTER@LHC): Feasibility Studies for Quarkonium and Drell-Yan Production

We outline the case for heavy-ion-physics studies using the multi-TeV lead LHC beams in the fixed-target mode. After a brief contextual reminder, we detail the possible contributions of AFTER@LHC to heavy-ion physics with a specific emphasis on quarkonia. We then present performance simulations for a selection of observables. These show that $\Upsilon(nS)$, $J/\psi$ and $\psi(2S)$ production in heavy-ion collisions can be studied in new energy and rapidity domains with the LHCb and ALICE detectors. We also discuss the relevance to analyse the Drell-Yan pair production in asymmetric nucleus-nucleus collisions to study the factorisation of the nuclear modification of partonic densities and of further quarkonia to restore their status of golden probes of the quark-gluon plasma formation.Comment: 18 pages, 7 figure

Possíveis genes Rps em linhagens de soja da Embrapa Trigo.

A podridão radicular de fitóftora, causada por Phytophthora sojae, pode causar redução de rendimento de grãos de soja de até 100% em cultivares altamente suscetíveis. A principal forma de controle da doença é o uso de cultivares com genes de resistência dominantes (Rps). O objetivo deste trabalho foi determinar possíveis genes Rps presentes em linhagens de soja desenvolvidas pela Embrapa Trigo. A caracterização da efetividade de genes Rps foi realizada pela técnica de inoculação do hipocótilo em plântulas das seguintes diferenciais: PI 547677 (Rps1a), PI 547842 (Rps1b), PI 547834 (Rps1c), PI 103091 (Rps1d), Williams 82 (Rps1k), PI 547838 (Rps2), PI 547862 (Rps3a), PI 591509 (Rps3b), L92-7857 (Rps3c), L85-2352 (Rps4), PI 547876 (Rps5), PI 591511 (Rps6), Harosoy (Rps7) e PI 399073 (Rps8). Considerou-se efetivo o gene da diferencial que apresentou até 30% de plantas mortas, e inefetivo, a diferencial com mortalidade de plantas acima de 70%. As linhagens desenvolvidas no programa de melhoramento genético de soja da Embrapa Trigo e testadas com o isolado Ps 2.4/07 podem possuir um ou mais dos seguintes genes dominantes de resistência à PRF: Rps1a, Rps1b, Rps1c, Rps1k, Rps3a e Rps8. Embora ainda considerados efetivos, os altos índices de mortalidade expressos pelo isolado Ps 2.4/07 a Rps1b e Rps3a não qualificariam estes genes para uso em manejo da PRF

Clinical study on the melarsoprol-related encephalopathic syndrome: risk factors and HLA association

Melarsoprol administration for the treatment of late-stage human African trypanosomiasis (HAT) is associated with the development of an unpredictable and badly characterized encephalopathic syndrome (ES), probably of immune origin, that kills approximately 50% of those affected. We investigated the characteristics and clinical risk factors for ES, as well as the association between the Human Leukocyte Antigen (HLA) complex and the risk for ES in a case-control study. Late-stage Gambiense HAT patients treated with melarsoprol and developing ES (69 cases) were compared to patients not suffering from the syndrome (207 controls). Patients were enrolled in six HAT treatment centres in Angola and in the Democratic Republic of Congo. Standardized clinical data was obtained from all participants before melarsoprol was initiated. Class I (HLA-A, HLA-B, HLA-Cw) and II (HLA-DR) alleles were determined by PCR-SSOP methods in 62 ES cases and 189 controls. The principal ES pattern consisted in convulsions followed by a coma, whereas ES with exclusively mental changes was not observed. Oedema, bone pain, apathy, and a depressed humour were associated with a higher risk of ES, while abdominal pain, coma, respiratory distress, and a Babinski sign were associated with higher ES-associated mortality. Haplotype C*14/B*15 was associated with an elevated risk for ES (OR: 6.64; p-value: 0.008). Haplotypes A*23/C*14, A*23/B*15 and DR*07/B*58 also showed a weaker association with ES. This result supports the hypothesis that a genetically determined peculiar type of immune response confers susceptibility for ES

Factorial Moments in a Generalized Lattice Gas Model

We construct a simple multicomponent lattice gas model in one dimension in which each site can either be empty or occupied by at most one particle of any one of $D$ species. Particles interact with a nearest neighbor interaction which depends on the species involved. This model is capable of reproducing the relations between factorial moments observed in high--energy scattering experiments for moderate values of $D$. The factorial moments of the negative binomial distribution can be obtained exactly in the limit as $D$ becomes large, and two suitable prescriptions involving randomly drawn nearest neighbor interactions are given. These results indicate the need for considerable care in any attempt to extract information regarding possible critical phenomena from empirical factorial moments.Comment: 15 pages + 1 figure (appended as postscript file), REVTEX 3.0, NORDITA preprint 93/4

Integral correlation measures for multiparticle physics

We report on a considerable improvement in the technique of measuring multiparticle correlations via integrals over correlation functions. A modification of measures used in the characterization of chaotic dynamical sytems permits fast and flexible calculation of factorial moments and cumulants as well as their differential versions. Higher order correlation integral measurements even of large multiplicity events such as encountered in heavy ion collisons are now feasible. The change from ``ordinary'' to ``factorial'' powers may have important consequences in other fields such as the study of galaxy correlations and Bose-Einstein interferometry.Comment: 23 pages, 6 tar-compressed uuencoded PostScript figures appended, preprint TPR-92-4

Photochemistry and photophysics of thienocarbazoles

Two methylated thienocarbazoles and two of their synthetic nitro-precursors have been examined by absorption, luminescence, laser flash photolysis and photoacoustic techniques. Their spectroscopic and photophysical characterization involves fluorescence spectra, fluorescence quantum yields and lifetimes, and phosphorescence spectra and phosphorescence lifetimes for all the compounds. Triplet-singlet difference absorption spectra, triplet molar absorption coefficients, triplet lifetimes, intersystem crossing S-1 similar tosimilar to--> T-1 and singlet molecular oxygen yields were obtained for the thienocarbazoles. In the case of the thienocarbazoles it was found that the lowest-lying singlet and triplet excited states, S, and T-1, are of pi,pi* origin, whereas for their precursors S-1 is n,pi*, and T-1 is pi,pi*. In both thienocarbazoles it appears that the thianaphthene ring dictates the S, T, yield, albeit there is less predominance of that ring in the triplet state of the linear thienocarbazole, which leads to a decrease in the observed Phi(T) value.info:eu-repo/semantics/publishedVersio