Large scale correlations of quasar polarisation vectors: Hints of extreme scale structures?

A survey measuring quasar polarization vectors has been started in two regions towards the North and South Galactic Poles. Here, We review the discovery of significant correlations of orientations of polarization vectors over huge angular distances. We report new results including a larger sample of the quasars confirming the existence of coherent orientations at redshifts z>1.Comment: Proc. of Astronomical Polarimetry - Current Status and Future Directions March 15-19, 2004. Waikoloa Beach Marriott, Hawaii. 5 pages, 3 figure

Dust in the Interplanetary Medium

The mass density of dust particles that form from asteroids and comets in the interplanetary medium of the solar system is, near 1 AU, comparable to the mass density of the solar wind. It is mainly contained in particles of micrometer size and larger. Dust and larger objects are destroyed by collisions and sublimation and hence feed heavy ions into the solar wind and the solar corona. Small dust particles are present in large number and as a result of their large charge to mass ratio deflected by electromagnetic forces in the solar wind. For nano dust particles of sizes 1 - 10 nm, recent calculations show trapping near the Sun and outside from about 0.15 AU ejection with velocities close to solar wind velocity. The fluxes of ejected nano dust are detected near 1AU with the plasma wave instrument onboard the STEREO spacecraft. Though such electric signals have been observed during dust impacts before, the interpretation depends on several different parameters and data analysis is still in progress.Comment: 12 pages, 8 figures, accepted for publication in Plasma Physics and Controlled Fusion, special issue 37th EPS Conference on Plasma Physic

Complexity Phenomena and ROMA of the Magnetospheric Cusp, Hydrodynamic Turbulence, and the Cosmic Web

Dynamic Complexity is a phenomenon exhibited by a nonlinearly interacting system within which multitudes of different sizes of large scale coherent structures emerge, resulting in a globally nonlinear stochastic behavior vastly different from that could be surmised from the underlying equations of interaction. The hallmark of such nonlinear, complex phenomena is the appearance of intermittent fluctuating events with the mixing and distributions of correlated structures at all scales. We briefly review here a relatively recent method, ROMA (rank-ordered multifractal analysis), explicitly constructed to analyze the intricate details of the distribution and scaling of such types of intermittent structures. This method is then applied to the analyses of selected examples related to the dynamical plasmas of the cusp region of the magnetosphere, velocity fluctuations of classical hydrodynamic turbulence, and the distribution of the structures of the cosmic gas obtained through large scale, moving mesh simulations. Differences and similarities of the analyzed results among these complex systems will be contrasted and highlighted. The first two examples have direct relevance to the geospace environment and are summaries of previously reported findings. The third example on the cosmic gas, though involving phenomena much larger in spatiotemporal scales, with its highly compressible turbulent behavior and the unique simulation technique employed in generating the data, provides direct motivations of applying such analysis to studies of similar multifractal processes in various extreme environments. These new results are both exciting and intriguing.Comment: 36 page

The auroral red line polarisation: modelling and measurements

In this work, we model the polarisation of the auroral red line using the electron impact theory developed by Bommier et al. (2011). This theory enables the computation of the distribution of the Degree of Linear Polarisation (DoLP) as a function of height if the flux of precipitated electrons is provided as input. An electron transport code is used to infer the stationary electron flux at each altitude in the ionosphere as a function of energy and pitch angle. Using adequate cross-sections, the integral of this electron flux over energy and pitch angle provides an anisotropy parameter from which the theoretical local DoLP can be computed at each altitude. The modelled DoLP is then derived by integrating along the line-of-sight. Depending on the integration length, the modelled DoLP ranges between 0.6% for a very long integration length and 1.8% for a very short integration length localised around an altitude of 210 km. A parametric study is performed to check how the characteristics of the local DoLP (maximum value, altitude of the maximum, integrated height profile) vary. It is found that the polarisation is highly sensitive to the scattering function of the electrons, to the electron precipitation and to the geomagnetic activity. We compare these values to measured ones obtained during an observational campaign performed in February 2012 from Svalbard. The measured DoLP during the campaign was 1.9% ± 0.1%. The comparison between this value and the theoretical one is discussed. Discrepancies may be due to the poor constraint of the input parameters (thermosphere and ionosphere), to the fact that only electron precipitation is considered in this approach (and not proton precipitation for instance) and to the difficulty in constraining the exact width of the emission layer in the thermosphere

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Efficacy and safety of the combination of rituximab, fludarabine, and mitoxantrone for rituximab-naive, recurrent/refractory follicular non-Hodgkin lymphoma with high tumor burden: a multicenter phase 2 trial by the Groupe d'Etude des Lymphomes de l'Adulte (GELA) and Groupe Ouest Est des Leucémies et Autres Maladies du Sang (GOELAMS).

International audienceBACKGROUND: This phase 2 trial was undertaken to evaluate the efficacy and safety of rituximab combined with intravenous fludarabine and mitoxantrone (R-FM) for patients with recurrent/refractory follicular lymphoma who had high tumor burden according to Groupe d'Etude des Lymphomes Folliculaires (GELF) criteria. METHODS: Fifty patients were enrolled who had received a maximum of 2 previous regimens, including 1 cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP)/CHOP-like regimen but no previous exposure to rituximab, fludarabine, or mitoxantrone. At baseline, 58% of patients had bulky disease (lesion > 7 cm), 56% had high-risk Follicular Lymphoma International Prognostic Index (FLIPI) scores (range, 3-5), and 22% were refractory. Treatment consisted of 4 courses of R-FM (rituximab 375 mg/m(2) intravenously on Day 1, fludarabine 25 mg/m(2) intravenously on Days 2 through 4, and mitoxantrone 10 mg/m(2) intravenously on Day 2, recycling at Day 28) and consolidation with 2 courses of fludarabine and mitoxantrone (the same regimen without rituximab). RESULTS: The best response (84% overall response rate including 68% complete response/complete response unconfirmed) was achieved after 4 courses of R-FM. Response rates were high regardless of age, refractoriness to last previous therapy, and FLIPI score. After a median follow-up of 4 years, the 3-year progression-free survival rate was 47%, the event-free survival rate was 41%, and the 3-year overall survival rate was 66%. Grade ≥ 3 neutropenia and infections were the most common toxicities and occurred in 72% and 14% of patients, respectively. CONCLUSIONS: Cytoreduction with 4 courses of R-FM was safe and highly efficient in patients with recurrent/refractory follicular lymphoma who had high tumor burden; however, better consolidation than FM is needed to further improve outcome

Fortuitous detection of uniparental isodisomy of chromosome 6.

Uniparental isodisomy is defined as the inheritance of two copies of the same parental chromosome and can result in defects when it produces homozygosity for a recessive mutation or in the presence of imprinting. We describe the detection of a chromosome 6 uniparental isodisomy in a 9 year old girl, discovered during a search for an HLA identical sib. HLA typing, erythrocyte phenotyping, and genotypes of microsatellite polymorphisms were compatible with a paternal isodisomy of chromosome 6, with normal biparental origin of the other chromosomes. Paternal cells were not responsive to the patient's cells in mixed lymphocyte cultures. This fortuitous detection of a chromosome 6 isodisomy suggests that cases of chromosome 6 UPD may not be deleterious and may therefore go undetected