32 research outputs found
Single spin asymmetries in QCD
Measurements of single transverse spin asymmetries in high energy inclusive
processes have always shown unexpected and challenging results. Several cases
are considered and discussed within a QCD approach which couples perturbative
dynamics to new non perturbative partonic information; the aim is that of
developing a consistent phenomenological description of these unusual single
spin phenomena, based on a generalized QCD factorization scheme.Comment: 14 pages, lectures delivered at School on "Symmetries and Spin",
Praha-SPIN-2001, Prague, July 15 - July 28, 200
Azimuthal asymmetries in lepton-pair production at a fixed-target experiment using the LHC beams (AFTER)
A multi-purpose fixed-target experiment using the proton and lead-ion beams
of the LHC was recently proposed by Brodsky, Fleuret, Hadjidakis and Lansberg,
and here we concentrate our study on some issues related to the spin physics
part of this project (referred to as AFTER). We study the nucleon spin
structure through and processes with a fixed-target experiment using
the LHC proton beams, for the kinematical region with 7 TeV proton beams at the
energy in center-of-mass frame of two nucleons GeV. We calculate
and estimate the azimuthal asymmetries of unpolarized and
dilepton production processes in the Drell--Yan continuum region and at the
-pole. We also calculate the , and
azimuthal asymmetries of and dilepton production
processes with the target proton and deuteron longitudinally or transversally
polarized in the Drell--Yan continuum region and around resonances region.
We conclude that it is feasible to measure these azimuthal asymmetries,
consequently the three-dimensional or transverse momentum dependent parton
distribution functions (3dPDFs or TMDs), at this new AFTER facility.Comment: 15 pages, 40 figures. Version accepted for publication in EPJ
Lambda polarization from unpolarized quark fragmentation
The longstanding problem of explaining the observed polarization of Lambda
hyperons inclusively produced in the high energy collisions of unpolarized
hadrons is tackled by considering spin and k_T dependent quark fragmentation
functions. The data on Lambda's and Lambda-bar's produced in p-N processes are
used to determine simple phenomenological expressions for these new "polarizing
fragmentation functions", which describe the experiments remarkably well.Comment: LaTeX, 21+1 pages, 6 eps figures, uses epsfig.st
Gene expression profiling of mucinous ovarian tumors and comparison with upper and lower gastrointestinal tumors identifies markers associated with adverse outcomes.
PURPOSE: Advanced-stage mucinous ovarian carcinoma (MOC) has poor chemotherapy response and prognosis and lacks biomarkers to aid stage I adjuvant treatment. Differentiating primary MOC from gastrointestinal (GI) metastases to the ovary is also challenging due to phenotypic similarities. Clinicopathologic and gene-expression data were analyzed to identify prognostic and diagnostic features. EXPERIMENTAL DESIGN: Discovery analyses selected 19 genes with prognostic/diagnostic potential. Validation was performed through the Ovarian Tumor Tissue Analysis consortium and GI cancer biobanks comprising 604 patients with MOC (n = 333), mucinous borderline ovarian tumors (MBOT, n = 151), and upper GI (n = 65) and lower GI tumors (n = 55). RESULTS: Infiltrative pattern of invasion was associated with decreased overall survival (OS) within 2 years from diagnosis, compared with expansile pattern in stage I MOC [hazard ratio (HR), 2.77; 95% confidence interval (CI), 1.04–7.41, P = 0.042]. Increased expression of THBS2 and TAGLN was associated with shorter OS in MOC patients (HR, 1.25; 95% CI, 1.04–1.51, P = 0.016) and (HR, 1.21; 95% CI, 1.01–1.45, P = 0.043), respectively. ERBB2 (HER2) amplification or high mRNA expression was evident in 64 of 243 (26%) of MOCs, but only 8 of 243 (3%) were also infiltrative (4/39, 10%) or stage III/IV (4/31, 13%). CONCLUSIONS: An infiltrative growth pattern infers poor prognosis within 2 years from diagnosis and may help select stage I patients for adjuvant therapy. High expression of THBS2 and TAGLN in MOC confers an adverse prognosis and is upregulated in the infiltrative subtype, which warrants further investigation. Anti-HER2 therapy should be investigated in a subset of patients. MOC samples clustered with upper GI, yet markers to differentiate these entities remain elusive, suggesting similar underlying biology and shared treatment strategies
The effect of chronic ingestion of ethanol on modulation of granulomatous inflammation in experimental schistosomiasis in mice Efeito da ingestão crônica de etanol na modulação da resposta inflamatória granulomatosa no fígado de camundongos infectados por Schistosoma mansoni
We studied the role of ethanol on the modulation of liver granulomata around Schistosoma mansoni eggs in mice. Albino mice, receiving 7% ethanol as the sole drinking liquid, at 60 and 90 days post-infection, presented smaller granulomata than controls did, when sacrificed at 120 days post-infection. No differences in diameters could be observed, when ethanol was given 4 months before up to 120 days after infection. The results suggested that modulation of schistosome granulomata by ethanol ingestion varies with time and duration of drug consumption.<br>Estudamos a modulação da resposta inflamatória granulomatosa em torno de ovos de S. mansoni no fígado de camundongos albinos (Mus musculus), que receberam 7% de etanol como única fonte de líquido. Os animais que receberam etanol aos 60 e 90 dias após a infecção apresentaram granulomas menores do que os controles, quando sacrificados aos 120 dias após a infecção. Não houve diferença no diâmetro dos granulomas quando a ingestão de etanol foi iniciada 4 meses antes e prolongada até 120 dias após a infecção. Nossos resultados indicam que a modulação da inflamação granulomatosa varia de acordo com o tempo e a duração da ingestão do etanol