9,844 research outputs found
Interpretation of AMS-02 electrons and positrons data
We perform a combined analysis of the recent AMS-02 data on electrons,
positrons, electrons plus positrons and positron fraction, in a self-consistent
framework where we realize a theoretical modeling of all the astrophysical
components that can contribute to the observed fluxes in the whole energy
range. The primary electron contribution is modeled through the sum of an
average flux from distant sources and the fluxes from the local supernova
remnants in the Green catalog. The secondary electron and positron fluxes
originate from interactions on the interstellar medium of primary cosmic rays,
for which we derive a novel determination by using AMS-02 proton and helium
data. Primary positrons and electrons from pulsar wind nebulae in the ATNF
catalog are included and studied in terms of their most significant (while
loosely known) properties and under different assumptions (average contribution
from the whole catalog, single dominant pulsar, a few dominant pulsars). We
obtain a remarkable agreement between our various modeling and the AMS-02 data
for all types of analysis, demonstrating that the whole AMS-02 leptonic data
admit a self-consistent interpretation in terms of astrophysical contributions.Comment: 33 pages, 26 figures and 4 tables, v2: accepted for publication in
JCAP, minor changes relative to v
Surgical management of rhinosinusitis in onco-hematological patients
ObjectivesIn onco-hematological diseases, the incidence of paranasal sinuses infection dramatically increase and requires a combination of medical and surgical therapy. Balloon dilatation surgery (DS) is a minimally invasive, tissue preserving procedure. The study evaluates the results of DS for rhinosinusitis in immunocompromised patients.MethodsA retrospective chart review was conducted in 110 hematologic patients with rhinosinusitis. Twenty-five patients were treated with DS technique and 85 patients with endoscopic sinus surgery (ESS). We considered the type of anesthesia and the extent of intra- and postoperative bleeding. Patients underwent Sino-Nasal Outcome Test (SNOT-20) to evaluate changes in subjective symptoms and global patient assessment (GPA) questionnaire to value patient satisfaction.ResultsLocal anesthesia was employed in 8 cases of DS and in 15 of ESS. In 50 ESS patients, an anterior nasal packing was placed and in 12 cases a repacking was necessary. In the DS group, nasal packing was required in 8 cases and in 2 cases a repacking was placed (P=0.019 and P=0.422, respectively). The SNOT-20 change score showed significant improvement of health status in both groups. However the DS group showed a major improvement in 3 voices: need to blow nose, runny nose, and facial pain/pressure. The 3-month follow-up GPA questionnaire showed an higher satisfaction of DS group.ConclusionBalloon DS represents a potentially low aggressive treatment and appears to be relatively safe and effective in onco-hematologic patients. All these remarks may lead the surgeon to consider a larger number of candidates for surgical procedure
The rotational shear layer inside the early red-giant star KIC 4448777
We present the asteroseismic study of the early red-giant star KIC 4448777,
complementing and integrating a previous work (Di Mauro et al. 2016), aimed at
characterizing the dynamics of its interior by analyzing the overall set of
data collected by the {\it Kepler} satellite during the four years of its first
nominal mission. We adopted the Bayesian inference code DIAMOND (Corsaro \& De
Ridder 2014) for the peak bagging analysis and asteroseismic splitting
inversion methods to derive the internal rotational profile of the star. The
detection of new splittings of mixed modes, more concentrated in the very inner
part of the helium core, allowed us to reconstruct the angular velocity profile
deeper into the interior of the star and to disentangle the details better than
in Paper I: the helium core rotates almost rigidly about 6 times faster than
the convective envelope, while part of the hydrogen shell seems to rotate at a
constant velocity about 1.15 times lower than the He core. In particular, we
studied the internal shear layer between the fast-rotating radiative interior
and the slow convective zone and we found that it lies partially inside the
hydrogen shell above and extends across the core-envelope
boundary. Finally, we theoretically explored the possibility for the future to
sound the convective envelope in the red-giant stars and we concluded that the
inversion of a set of splittings with only low-harmonic degree , even
supposing a very large number of modes, will not allow to resolve the
rotational profile of this region in detail.Comment: accepted for publication on Ap
Progress in Developing Hybrid RPCs: GEM-like Detectors with Resistive Electrodes
We have recently developed an innovative detector of photons and charged
particles: a GEM-like gaseous amplification structure with resistive electrodes
instead of commonly used metallic ones. This novel detector combines the best
property of GEMs- the capability to operate in a cascaded mode and in poorly
quenched gases - and of RPC: the protection against sparks. In this paper will
shortly review our latest achievements in this direction, however the main
focus will be given on a new advanced design that allows to build large area
detectors manufactured by a screen printing technology. The proposed detector,
depending on the applications, can operate either in a GEM mode (electron
multiplications through holes only) or as a hybrid RPC with simultaneous
amplifications in the drift region and in the holes. The possible applications
of this new detector will be discussed
Reforming the international financial system
Against the backdrop of the present crisis this Forum is dedicated to the discussion of measures to prevent future breakdowns of the global economy. Daniel Gros, Ulrich Klüh and Beatrice Weder di Mauro regard as the biggest flaw in the existing structures the lack of an institution that has the information, expertise and impartiality that would enable it to swiftly identify and frankly communicate emerging risks to the global financial system and the world economy. They present a proposal that aims at placing the IMF in a position to play this part. The paper by Philip Lane focuses on how reforms in the governance of the global financial system may alter the incentives facing those emerging market economies that have opted to run large and globally inefficient current account surpluses as insurance against the risks of disruptions in capital flows to these economies
Efficiency of microsatellite markers in assisted selection for resistance to soybean cyst nematode (race 3).
Four microsatellite sequences were tested in soybean DNA from cultivars and segregating genotypes. Three of them were close to the resistance locus rhg 1 on molecular linkage group G (Satt 309, Sat_168, Sat_163) and one was close to Rhg4 locus on group A2 (Sat_162). Progenies previously classified as cyst nematode (SNC) resistant and others with unknown reaction were tested, using the resistant cultivars Liderança, and Renascença and the susceptibles 'Cristalina' and 'OCEPAR-4' as control. The best primer for resistance to SCN was Sat_162. Twenty segregant progenies tested with Sat_162 presented a 150 bp band for homozygous resistant genotypes and 200 bp for susceptible ones, and both for the heterozigous genotypes. Previous studies have shown that this microsatellite marker is efficient to select genotypes carrying Peking-derivative resistance. 'Peking' takes part in the in the genealogy of all segregant progenies evaluated in this study. Thus, the obtained results showed that Sat_162 distinguished resistant and susceptible soybean genotypes to SCN, race 3
Internal rotation of the red-giant star KIC 4448777 by means of asteroseismic inversion
In this paper we study the dynamics of the stellar interior of the early
red-giant star KIC 4448777 by asteroseismic inversion of 14 splittings of the
dipole mixed modes obtained from {\it Kepler} observations. In order to
overcome the complexity of the oscillation pattern typical of red-giant stars,
we present a procedure which involves a combination of different methods to
extract the rotational splittings from the power spectrum. We find not only
that the core rotates faster than the surface, confirming previous inversion
results generated for other red giants (Deheuvels et al. 2012,2014), but we
also estimate the variation of the angular velocity within the helium core with
a spatial resolution of and verify the hypothesis of a sharp
discontinuity in the inner stellar rotation (Deheuvels et al. 2014). The
results show that the entire core rotates rigidly with an angular velocity of
about ~nHz and provide evidence for an
angular velocity decrease through a region between the helium core and part of
the hydrogen burning shell; however we do not succeed to characterize the
rotational slope, due to the intrinsic limits of the applied techniques. The
angular velocity, from the edge of the core and through the hydrogen burning
shell, appears to decrease with increasing distance from the center, reaching
an average value in the convective envelope of
~nHz. Hence, the core in KIC~4448777 is
rotating from a minimum of 8 to a maximum of 17 times faster than the envelope.
We conclude that a set of data which includes only dipolar modes is sufficient
to infer quite accurately the rotation of a red giant not only in the dense
core but also, with a lower level of confidence, in part of the radiative
region and in the convective envelope.Comment: accepted for publication on Ap
Internal rotation of red giants by asteroseismology
We present an asteroseismic approach to study the dynamics of the stellar
interior in red-giant stars by asteroseismic inversion of the splittings
induced by the stellar rotation on the oscillation frequencies. We show
preliminary results obtained for the red giant KIC4448777 observed by the space
mission Kepler.Comment: 3 pages, 4 figures, the 40th Liege International Astrophysical
Colloquium Liac40, 'Ageing low mass stars: from red giants to white dwarfs',
to be published on EPJ Web of Conference
Plio-Pleistocene geological evolution of the northern Sicily continental margin (southern Tyrrhenian Sea): new insights from high-resolution, multi-electrode sparker profiles
High-resolution seismic profiles were acquired in the north Sicily offshore region with an innovative, multi-tip sparker array which lacks ringing and has a base frequency around 600 Hz. The new data, combined
with published data, suggest that intra-slope and extensional basins formed as a consequence of the late
Miocene (?)–early Pliocene shortening and thrusting,
and the middle (?)–late Pliocene continental rifting affecting the internal side of the Sicilian-Maghrebian chain. Early (?) Pleistocene to Holocene high-amplitude
and high-frequency sea-level changes resulted in repeated
sub-aerial exposure and flooding of the shelf, and the deposition of cyclically arranged hemipelagic and shelf sediments. An uplift of the shelf could explain the non-preservation of the transgressive and of the lowstand wedge systems tracts in the oldest sequences
Beam lead technology
Beam lead technology for microcircuit interconnections with applications to metallization, passivation, and bondin
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