640 research outputs found
Acquisition and preliminary analysis of multi-channel seismic reflection data, acquired during the oceanographic cruises of the TOMO-ETNA experiment
The TOMO-ETNA experiment was performed in the framework of the FP7 “MED-SUV” (MEDiterranean SUpersite Volcanoes) in order to gain a detailed geological and structural model of the continental and oceanic crust concerning Etna and Aeolian Islands volcanoes (Sicily, Italy), by means of active and passive seismic exploration methodologies. Among all data collected, some 1410 km of marine multi-channel seismic (MCS) reflection profiles were acquired in the Ionian and Tyrrhenian Seas during two of the three oceanographic cruises of the TOMO-ETNA experiment, in July and November 2014, with the aim of shading light to deep, intermediate and shallow stratigraphy and crustal structure of the two above mentioned areas. The MCS sections, targeted to deep exploration, were acquired during the oceanographic cruise on board of the R/V “Sarmiento de Gamboa”, using an active seismic source of 16 air-guns, for a total volume of 4340 cu. in., and a 3000 m long, 240-channels digital streamer as receiving system. High-resolution seismic profiles were instead collected through the R/V “Aegaeo”, using two smaller air-guns (overall 270 cu. in. volume) and a 96 channels, 300 m long digital streamer. This paper provides a detailed description of the acquisition parameters and main processing steps adopted for the MCS data. Some processed lines are shown and preliminarily interpreted, to highlight the overall good quality and the high potential of the MCS sections collected during the TOMO-ETNA experiment. © 2016 by the Istituto Nazionale di Geofisica e Vulcanologia. All rights reserved
A three-year study of brain atrophy after autologous hematopoietic stem cell transplantation in rapidly evolving secondary progressive multiple sclerosis
BACKGROUND AND PURPOSE: In multiple sclerosis (MS), autologous hematopoietic stem cell transplantation (AHSCT) induces a profound suppression of clinical activity and MR imaging-detectable inflammation, but it may be associated with a rapid brain volume loss in the months subsequent to treatment. The aim of this study was to assess how AHSCT affects medium-term evolution of brain atrophy in MS. MATERIALS AND METHODS: MR imaging scans of the brain from 14 patients with rapidly evolving secondary-progressive MS obtained 3 months before and every year after AHSCT for 3 years were analyzed. Baseline normalized brain volumes and longitudinal percentage of brain volume changes (PBVCs) were assessed using the Structural Image Evaluation of Normalized Atrophy software. RESULTS: The median decrease of brain volume was 1.92% over the first year after AHSCT and then declined to 1.35% at the second year and to 0.69% at the third year. The number of enhancing lesions seen on the pretreatment scans was significantly correlated with the PBVCs between baseline and month 12 (r = -0.62; P = .02); no correlation was found with the PBVCs measured over the second and third years. CONCLUSIONS: After AHSCT, the rate of brain tissue loss in patients with MS declines dramatically after the first 2 years. The initial rapid development of brain atrophy may be a late consequence of the pretransplant disease activity and/or a transient result of the intense immunoablative conditioning procedure
Chronic GVHD is associated with inferior relapse risk irrespective of stem cell source among patients receiving transplantation from unrelated donors
Learning ability correlates with brain atrophy and disability progression in RRMS
Objective To assess the prognostic value of practice effect on Paced Auditory Serial Addition Test (PASAT) in multiple sclerosis. Methods We compared screening (day a '14) and baseline (day 0) PASAT scores of 1009 patients from the FTY720 Research Evaluating Effects of Daily Oral therapy in Multiple Sclerosis (FREEDOMS) trial. We grouped patients into high and low learners if their PASAT score change was above or below the median change in their screening PASAT quartile group. We used Wilcoxon test to compare baseline disease characteristics between high and low learners, and multiple regression models to assess the respective impact of learning ability, baseline normalised brain volume and treatment on brain volume loss and 6-month confirmed disability progression over 2 years. Results The mean PASAT score at screening was 45.38, increasing on average by 3.18 from day a '14 to day 0. High learners were younger (p=0.003), had lower Expanded Disability Status Scale score (p=0.031), higher brain volume (p<0.001) and lower T2 lesion volume (p=0.009) at baseline. Learning status was not significantly associated with disability progression (HR=0.953, p=0.779), when adjusting for baseline normalised brain volume, screening PASAT score and treatment arm. However, the effect of fingolimod on disability progression was more pronounced in high learners (HR=0.396, p<0.001) than in low learners (HR=0.798, p=0.351; p for interaction=0.05). Brain volume loss at month 24 tended to be higher in low learners (0.17%, p=0.058), after adjusting for the same covariates. Conclusions Short-term practice effects on PASAT are related to brain volume, disease severity and age and have clinically meaningful prognostic implications. High learners benefited more from fingolimod treatment
Orbital analysis of stars in the nuclear stellar disc of the Milky Way
Context. While orbital analysis studies were so far mainly focused on the Galactic halo, it is possible now to do these studies in the heavily obscured region close to the Galactic Centre.Aims. We aim to do a detailed orbital analysis of stars located in the nuclear stellar disc (NSD) of the Milky Way allowing us to trace the dynamical history of this structure.Methods. We integrated orbits of the observed stars in a non-axisymmetric potential. We used a Fourier transform to estimate the orbital frequencies. We compared two orbital classifications, one made by eye and the other with an algorithm, in order to identify the main orbital families. We also compared the Lyapunov and the frequency drift techniques to estimate the chaoticity of the orbits.Results. We identified several orbital families as chaotic, z-tube, x-tube, banana, fish, saucer, pretzel, 5:4, and 5:6 orbits. As expected for stars located in a NSD, the large majority of orbits are identified as z-tubes (or as a sub-family of z-tubes). Since the latter are parented by x2 orbits, this result supports the contribution of the bar (in which x2 orbits are dominant in the inner region) in the formation of the NSD. Moreover, most of the chaotic orbits are found to be contaminants from the bar or bulge which would confirm the predicted contamination from the most recent NSD models.Conclusions. Based on a detailed orbital analysis, we were able to classify orbits into various families, most of which are parented by x2-type orbits, which are dominant in the inner part of the bar
A revised day +7 predictive score for transplant-related mortality: serum cholinesterase, total protein, blood urea nitrogen, γ glutamyl transferase, donor type and cell dose
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Synthetic dust polarization emission maps at 353 GHz for an observer placed inside a Local Bubble-like cavity
We present a study of synthetic observations of polarized dust emission at
353 GHz as seen by an observer within a cavity in the interstellar medium
(ISM). The cavity is selected from a magnetohydrodynamic simulation of the
local ISM with time-dependent chemistry, star formation, and stellar feedback
in form of supernova explosions with physical properties comparable to the
Local Bubble ones. We find that the local density enhancement together with the
coherent magnetic field in the cavity walls makes the selected candidate a
translucent polarization filter to the emission coming from beyond its domains.
This underlines the importance of studying the Local Bubble in further detail.
The magnetic field lines inferred from synthetic dust polarization data are
qualitatively in agreement with the all-sky maps of polarized emission at 353
GHz from the Planck satellite in the latitudes interval 15deg <= |b| <= 65deg.
As our numerical simulation allows us to track the Galactic midplane only out
to distances of 250 pc, we exclude the region |b|<15deg from our analysis. At
large Galactic latitudes, our model exhibits a high degree of small-scale
structures. On the contrary, the observed polarization pattern around the
Galactic poles is relatively coherent and regular, and we argue that the global
toroidal magnetic field of the Milky Way is important for explaining the data
at |b| > 65deg. We show that from our synthetic polarization maps, it is
difficult to distinguish between an open and a closed Galactic cap using the
inferred magnetic field morphology alone
A CO Funnel in the Galactic Centre: Molecular Counterpart of the Northern Galactic Chimney?
We report the discovery of a velocity coherent, funnel shaped ^13CO emission
feature in the Galactic centre (GC) using data from the SEDIGISM survey. The
molecular cloud appears as a low velocity structure (V_LSR=[-3.5, +3.5] km/s)
with an angular extent of 0.95{\deg} x 1{\deg}, extending toward positive
Galactic latitudes. The structure is offset from Sgr A* toward negative
Galactic longitudes and spatially and morphologically correlates well with the
northern lobe of the 430 pc radio bubble, believed to be the radio counterpart
of the multiwavelength GC chimney. Spectral line observations in the frequency
range of 85-116 GHz have been carried out using the IRAM 30 metre telescope
toward 12 positions along the funnel-shaped emission. We examine the ^12C/^13C
isotopic ratios using various molecules and their isotopologues. The mean
^12C/^13C isotope ratio (30.6+-2.9) is consistent with the structure located
within inner 3 kpc of the Galaxy and possibly in the GC. The velocity of the
molecular funnel is consistent with previous radio recombination line
measurements of the northern lobe of radio bubble. Our multiwavelength analysis
suggests that the funnel shaped structure extending over 100 pc above the
Galactic plane is the molecular counterpart of the northern GC chimney.Comment: Accepted for publication in A&A Letter
First metallicity determination from Near-Infrared spectra for five obscured Cepheids discovered in the inner Disk
We report the discovery of five new classical Cepheids located in the inner Galactic Disk at longitude l ≃ −40° in our IRSF/SIRIUS Near-Infrared (NIR) variability survey. The new Cepheids are unique in probing the kinematics and metallicity of young stars at the transition between the inner Disk and the minor axis of the central Bar, where they are expected to be less affected by its dynamical influence. This is also the first time that metallicity of Cepheids is estimated on the basis of medium-resolution (R ∼ 3, 000) NIR spectra, and we validated our results with data in the literature, finding a minimal dependence on the adopted spectroscopic diagnostics. This result is very promising for using Cepheids as stellar proxy of the present-time chemical content of the obscured regions in the Disk. We found that the three Cepheids within 8–10 kpc from us have metallicities consistent with the mean radial metallicity gradient, and kinematics consistent with the Galactic rotation curve. Instead, the closest (∼4 kpc)/farthest (∼12 kpc) Cepheids have significant negative/positive residuals, both in velocity and in iron content. We discuss the possibility that such residuals are related to large-scale dynamical instabilities, induced by the bar/spiral-arm pattern, but the current sample is too limited to reach firm conclusion
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