A possible use for polarizers in imaging atmospheric Cherenkov telescopes

Cherenkov radiation produced in Extensive Air Showers shows a net polarization. This article discusses its properties and physical origin, and proposes an arrangement of polarizers potentially useful for Imaging Atmospheric Cherenkov Telescopes.Comment: 30 pages, 13 figures. Accepted for publication in Astroparticle Physic

Validation of the international prognostic index in working formulation group a low-grade non-Hodgkin's lymphoma: retrospective analysis of 137 patients from the Gruppo Italiano per lo studio dei linfomi registry.

BACKGROUND AND OBJECTIVE: The subset of non-follicular non-Hodgkin's lymphoma (NHL) includes patients with varied prognoses, thus suitable for different therapeutic approaches. The International Prognostic Index (IPI), originally proposed for aggressive NHL, has been demonstrated to be of prognostic relevance also in follicular NHL. The main aim of the study was to validate the IPI in this histologic category; in addition, the specific prognostic classification, currently employed in the Gruppo Italiano per lo Studio dei Linfomi (GISL) prospective therapeutic trials and based on different features, more similar to those applied to chronic lymphocytic leukemia, was analyzed. DESIGN AND METHODS: The present series consists of 137 evaluable patients affected by Working Formulation group A NHL out of 256 cases referred to the GISL Registry. The retrospective prognostic study included the evaluation by both univariate and multivariate analyses of overall survival, response to therapy and response duration. The IPI was applied as originally proposed. The GISL definition of indolent and aggressive disease at diagnosis was based on the presence of B symptoms, bulky disease, anemia and thrombocytopenia. RESULTS: The distribution of patients in IPI risk groups was rather unbalanced with 18%, 47%, 28% and 7% of cases classified as low (L), intermediate-low (IL), intermediate-high (IH) and high (H) risk, respectively. The median overall survival was not reached in either L or IL risk groups, and was 84.1 and 7.4 months for IH and H risk groups, respectively (p=0. 0005). A simplified IPI model was designed merging patients in both intermediate risk groups and the statistical difference of survival retained its significance. GISL prognostic stratification was demonstrated to have a significant association with survival, with a median survival of 71.3 months in aggressive disease and a median survival not reached at 152 months in indolent disease. Both the simplified IPI model and the GISL risk definition retained their significance in multivariate analysis for overall survival, while for response to therapy only the simplified IPI model resulted to be of statistical significance. In addition, the GISL prognostic stratification identified patients with different outcomes within the IPI intermediate risk group, with a median survival of 70.2 months for patients with aggressive disease wheras the median survival for those with indolent disease was not reached. Finally, a prognostic score resulting from the integration of the simplified IPI and the GISL system was statistically validated. INTERPRETATION AND CONCLUSIONS: The retrospective analysis of this series demonstrates the validity of the IPI in non-follicular indolent NHL and the usefulness of integrating the IPI parameters with disease specific prognostic variables

Clinical relevance of immunophenotype in a retrospective comparative study of 297 peripheral T-cell lymphomas, unspecified, and 496 diffuse large B-cell lymphomas: experience of the Intergruppo Italiano Linformi.

BACKGROUND. To assess the impact of T-cell/B-cell phenotype on clinical outcome, the authors retrospectively compared patients who had peripheral T-cell lymphoma, unspecified (PTCL-U), with patients who had diffuse large B-cell lymphoma (DLBCL). METHODS. Two hundred ninety-seven cases of PTCL-U and 496 cases of DLBCL that had been transferred from the files of the Intergruppo Italiano Linfomi or the Gruppo Italiano Linfomi were integrated into a unique working file and reviewed by the authors. RESULTS. The PTCL-U group and the DLBCL group had significantly different distribution patterns with respect to patient age, gender, disease stage, performance status (PS), the presence or absence of systemic B symptoms, the presence or absence of bulky disease, lactic acid dehydrogenase (LDH) levels, and number of extranodal sites (ENS). A significantly greater number of patients in the DLBCL group experienced complete remission (P < 0.0001). Multinomial logistic regression analysis confirmed that immunophenotype, PS, LDH concentration, and number of ENS were independent predictors of response. At a median follow-tip duration of 43 months, there was no observable difference in disease-free Survival (DFS) between patients with DLBCL and patients with PTCL-U; however, multivariate analysis did reveal that poorer PS and bone marrow involvement were significantly associated with shorter DFS. Furthermore, although the overall survival (OS) curves associated with the T-cell and B-cell ummunophenotypes were significantly different from each other at a median follow-up duration of 37 months (P = 0.0012), Cox multivariate analysis excluded immunophenotype from the final OS model. CONCLUSIONS. The findings made in the current study indicate that the natural history of PTCL-U may differ from that of DLBCL. Patients with PTCL-U tended to have less favorable clinical outcomes, although the observed difference in outcome was only partially attributable to immunophenotype, which was independently associated with response, but not with survival. Differences in prognostic factor distributions between patients with PTCL-U and patients with DLBCL may account for some portion of the expected phenotype-associated risk

CCNU, vinblastine, procarbazine and prednisone (CVPP) with extended-field radiotherapy in the treatment of early unfavorable Hodgkin's disease - A prospective study on behalf of the Gruppo Italiano per lo Studio dei Linfomi (GISL)

Purpose. To test the adequacy of the CVPP four-drug regimen as ancillary chemotherapy associated with extended-field radiotherapy in the treatment of early, unfavorable, clinically staged Hodgkin's disease. Patients and Methods. The population of this prospective, multicenter study consisted of 49 patients with stage I-II disease, associated with bulky involvement or unfavorable histology (lymphocyte-depleted nodular sclerosis or lymphocyte depletion), systemic symptoms or extranodal involvement, or presenting with stage III A favorable-histology disease, with or without extranodal involvement. Results. Complete remission was achieved in 39 patients, partial remission in 2, while 8 patients did not respond. Four patients have relapsed so far (median follow-up: 43 months), all of whom were subsequently rescued with different salvage treatments. Dose intensity (mean+/-SD: 0.83+/-0.12) and hematological toxicity (including 2 deaths from infection) were higher when RT followed CT than when it was interposed in the middle of the 6 cycles. No growth factors were used. Nonhematological toxicity was very low and fully tolerable. Conclusions. Results confirmed the mild neurological and gastroenteric side effects of CVPP that make it an interesting MOPP-variant regimen. This combination seems most indicated when a regimen devoid of cardiac and pulmonary toxicity is required for association with full-dosage mediastinal radiotherapy, as is often the case in early, unfavorable Hodgkin's disease. The optimal sequence consists of radiotherapy administered after completion of the chemotherapy program. The use of growth factors for correction (or prevention) of marked leukopenia seems appropriate

Measurement of the cross-section and charge asymmetry of WW bosons produced in proton-proton collisions at s=8\sqrt{s}=8 TeV with the ATLAS detector

This paper presents measurements of the $W^+ \rightarrow \mu^+\nu$ and $W^- \rightarrow \mu^-\nu$ cross-sections and the associated charge asymmetry as a function of the absolute pseudorapidity of the decay muon. The data were collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with the ATLAS experiment at the LHC and correspond to a total integrated luminosity of 20.2~\mbox{fb^{-1}}. The precision of the cross-section measurements varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the 1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured with an uncertainty between 0.002 and 0.003. The results are compared with predictions based on next-to-next-to-leading-order calculations with various parton distribution functions and have the sensitivity to discriminate between them.Comment: 38 pages in total, author list starting page 22, 5 figures, 4 tables, submitted to EPJC. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2017-13

Search for chargino-neutralino production with mass splittings near the electroweak scale in three-lepton final states in √s=13 TeV pp collisions with the ATLAS detector

A search for supersymmetry through the pair production of electroweakinos with mass splittings near the electroweak scale and decaying via on-shell W and Z bosons is presented for a three-lepton final state. The analyzed proton-proton collision data taken at a center-of-mass energy of √s=13  TeV were collected between 2015 and 2018 by the ATLAS experiment at the Large Hadron Collider, corresponding to an integrated luminosity of 139  fb−1. A search, emulating the recursive jigsaw reconstruction technique with easily reproducible laboratory-frame variables, is performed. The two excesses observed in the 2015–2016 data recursive jigsaw analysis in the low-mass three-lepton phase space are reproduced. Results with the full data set are in agreement with the Standard Model expectations. They are interpreted to set exclusion limits at the 95% confidence level on simplified models of chargino-neutralino pair production for masses up to 345 GeV

Search for direct stau production in events with two hadronic tau-leptons in root s=13 TeV pp collisions with the ATLAS detector

A search for the direct production of the supersymmetric partners ofτ-leptons (staus) in final stateswith two hadronically decayingτ-leptons is presented. The analysis uses a dataset of pp collisions corresponding to an integrated luminosity of139fb−1, recorded with the ATLAS detector at the LargeHadron Collider at a center-of-mass energy of 13 TeV. No significant deviation from the expected StandardModel background is observed. Limits are derived in scenarios of direct production of stau pairs with eachstau decaying into the stable lightest neutralino and oneτ-lepton in simplified models where the two staumass eigenstates are degenerate. Stau masses from 120 GeV to 390 GeV are excluded at 95% confidencelevel for a massless lightest neutralino

Splenic marginal zone lymphoma: a prognostic model for clinical use.

The Integruppo Italiano Linfomi (IIL) carried out a study to assess the outcomes of splenic marginal zone lymphoma and to identify prognostic factors in 309 patients. The 5-year cause-specific survival (CSS) rate was 76%. In univariate analysis, the parameters predictive of shorter CSS were hemoglobin levels below 12 g/dL (P < .001), albumin levels below 3.5 g/dL (P = .001), International Prognostic Index (IPI) scores of 2 to 3 (P < .001), lactate dehydrogenase (LDH) levels above normal (P < .001), age older than 60 years (P = .01), platelet counts below 100 000/μL (P = .04), HbsAg-positivity (P = .01), and no splenectomy at diagnosis (P = .006). Values that maintained a negative influence on CSS in multivariate analysis were hemoglobin level less than 12 g/dL, LDH level greater than normal, and albumin level less than 3.5 g/dL. Using these 3 variables, we grouped patients into 3 prognostic categories: low-risk group (41%) with no adverse factors, intermediate-risk group (34%) with one adverse factor, and high-risk group (25%) with 2 or 3 adverse factors. The 5-year CSS rate was 88% for the low-risk group, 73% for the intermediate-risk group, and 50% for the high-risk group. The cause-specific mortality rate (x 1000 person-years) was 20 for the low-risk group, 47 for the intermediate-risk group, and 174 for the high-risk group. This latter group accounted for 54% of all lymphoma-related deaths. In conclusion, with the use of readily available factors, this prognostic index may be an effective tool for evaluating the need for treatment and the intensity of therapy in an individual patient. © 2006 by The American Society of Hematology

Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector

Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente

Silver-Russell syndrome. Clinical and etiopathological aspects of a model genomic imprinting entity

Silver-Russell syndrome is characterized by asymmetrical intrauterine growth retardation, with normal head circumference and small, pointed chin, which results in a triangular face. It can also include body asymmetry, among other characteristics. Its global incidence is estimated at 1 in 30 000-100 000 births, even though this figure may be underestimated. In approximately 60 % of cases, a molecular cause can be identified, and the main one is hypomethylation of the paternal allele at the imprinting control region 1 located at 11p15.5-p15.4. It is necessary to make the diagnosis of this entity, exclude differential diagnoses, and know (epi)genotype-phenotype correlations in order to ensure an adequate follow-up, provide available therapeutic options, and offer a timely family genetic counseling. The objective of this article is to describe the current status of the Silver-Russell syndrome, a model of genomic imprinting disorder