51 research outputs found
How small wine Italian company from Puglia can enter the Chinese-Shanghai market
This paper encompasses the strategy for small-medium wine companies from Puglia (Italy) to
enter the Chinese market. The study was conducted to understand the reasons why the
excellent quality wine from Puglia has no penetration in the Chinese market.
The research took into consideration the position in terms of production, size and exports in
the world of Italian producers from Puglia and their competitors in China. After analysing the
market and the opportunities, the report develops a strategy of cooperation among the
companies to obtain more resources and more power in order to better approach this
enormous and difficult market
The Powerful Jet and Gamma-Ray Flare of the Quasar PKS 0438436
PKS 0438436 at a redshift of has been previously recognized as
possessing perhaps the most luminous known synchrotron jet. Little is known
about this source since the maximum elevation above the horizon is low for the
Very Large Array (VLA). We present the first VLA radio image that detects the
radio lobes. We use both the 151 MHz luminosity, as a surrogate for the
isotropic radio lobe luminosity, and the lobe flux density from the radio image
to estimate a long term, time averaged, jet power, . We analyze two deep optical spectra with
strong broad emission lines and estimate the thermal bolometric luminosity of
the accretion flow, . The ratio, , is at
the limit of this empirical metric of jet dominance seen in radio loud quasars
and this is the most luminous accretion flow to have this limiting behavior.
Despite being a very luminous blazar, it previously had no -ray
detections (EGRET, AGILE or FERMI) until December 11 - 13 2016 (54 hours) when
FERMI detected a flare that we analyze here. The isotropic apparent luminosity
from 100 MeV - 100 GeV rivals the most luminous detected blazar flares
(averaged over 18 hours), . The
-ray luminosity varies over time by two orders of magnitude,
highlighting the extreme role of Doppler abberation and geometric alignment in
producing the inverse Compton emission.Comment: To appear in ApJ. Revision required to replace the last figure file
with the current versio
Beginning a journey across the universe: the discovery of extragalactic neutrino factories
Neutrinos are the most elusive particles in the Universe, capable of
traveling nearly unimpeded across it. Despite the vast amount of data
collected, a long standing and unsolved issue is still the association of
high-energy neutrinos with the astrophysical sources that originate them.
Amongst the candidate sources of neutrinos there are blazars, a class of
extragalactic sources powered by supermassive black holes that feed highly
relativistic jets, pointed towards the Earth. Previous studies appear
controversial, with several efforts claiming a tentative link between
high-energy neutrino events and individual blazars, and others putting into
question such relation. In this work we show that blazars are unambiguously
associated with high-energy astrophysical neutrinos at unprecedented level of
confidence, i.e. chance probability of 6 x 10^{-7}. Our statistical analysis
provides the observational evidence that blazars are astrophysical neutrino
factories and hence, extragalactic cosmic-ray accelerators.Comment: Published in ApJ
Toward a Public MAGIC Gamma-Ray Telescope Legacy Data Portal
The MAGIC telescopes are one of the three major IACTs (Imaging Atmospheric
Cherenkov Telescopes) for observation of gamma rays in the TeV regime currently
operative. MAGIC functions since 2003, and has published data from more than 60
sources, mostly blazars. MAGIC already provides astronomical exttt.fits
files with basic final scientific products such as spectral energy
distributions, light curves and skymaps from published results. In future, the
format of the files can be complemented with further relevant information to
the community: a) by including the full multi-wavelength dataset enclosed in a
publication, b) providing data in alternative easy-to-use formats such as ASCII
or ECSV, which are accessible with other commonly used packages such as
extttastropy or extttgammapy. Finally, besides high level products,
activities have started to provide photon event lists and instrument response
functions in a format such that scientists within and outside the community are
allowed to perform higher level analysis. A second aim is to provide a full
legacy of MAGIC data. This contribution will illustrate the achievements and
plans of this activity
Hadronic processes at work in 5BZB J0630-2406
Recent observations are shedding light on the important role that active
galactic nuclei (AGN) play in the production of high-energy neutrinos. In this
study, we focus on one object, 5BZB J0630-2406, which is among the blazars
recently proposed as associated with neutrino emission during the first 7-yr
IceCube observations. Modelling the quasi-simultaneous, broad-band spectral
energy distribution, we explore various scenarios from purely leptonic to
lepto-hadronic models, testing the inclusion of external photon fields. This
theoretical study provides a complementary testing ground for the proposed
neutrino-blazar association. Despite being historically classified as a BL Lac,
our study shows that 5BZB J0630-2406 belongs to the relatively rare sub-class
of high-power flat-spectrum radio quasars (FSRQs). Our results indicate that
interactions between protons and external radiation fields can produce a
neutrino flux that is within the reach of the IceCube detector. Furthermore,
the spectral shape of the X-ray emission suggests the imprint of hadronic
processes related to very energetic protons.Comment: Accepted for publication. 18 pages, 10 figure
A ring accelerator? Unusual jet dynamics in the IceCube candidate PKS 1502+106
On 2019/07/30.86853 UT, IceCube detected a high-energy astrophysical neutrino
candidate. The Flat Spectrum Radio Quasar PKS 1502+106 is located within the 50
percent uncertainty region of the event. Our analysis of 15 GHz Very Long
Baseline Array (VLBA) and astrometric 8 GHz VLBA data, in a time span prior and
after the IceCube event, reveals evidence for a radio ring structure which
develops with time. Several arc-structures evolve perpendicular to the jet
ridge line. We find evidence for precession of a curved jet based on kinematic
modelling and a periodicity analysis. An outflowing broad line region (BLR)
based on the C IV line emission (Sloan Digital Sky Survey, SDSS) is found. We
attribute the atypical ring to an interaction of the precessing jet with the
outflowing material. We discuss our findings in the context of a spine-sheath
scenario where the ring reveals the sheath and its interaction with the
surroundings (narrow line region, NLR, clouds). We find that the radio emission
is correlated with the -ray emission, with radio lagging the
-rays. Based on the -ray variability timescale, we constrain
the -ray emission zone to the BLR (30-200 ) and within the
jet launching region. We discuss that the outflowing BLR provides the external
radiation field for -ray production via external Compton scattering.
The neutrino is most likely produced by proton-proton interaction in the blazar
zone (beyond the BLR), enabled by episodic encounters of the jet with dense
clouds, i.e. some molecular cloud in the NLR.Comment: 35 pages, 33 figures, 3 tables; accepted by the MNRAS Main Journa
A MST algorithm for source detection in gamma-ray images
We developed a source detection algorithm based on the Minimal Spanning Tree
(MST), that is a graph-theoretical method useful for finding clusters in a
given set of points. This algorithm is applied to gamma-ray bidimensional
images where the points correspond to the arrival direction of photons, and the
possible sources are associated with the regions where they clusterize. Some
filters to select these clusters and to reduce the spurious detections are
introduced. An empirical study of the statistical properties of MST on random
fields is carried in order to derive some criteria to estimate the best filter
values. We introduce also two parameters useful to verify the goodness of
candidate sources. To show how the MST algorithm works in the practice, we
present an application to an EGRET observation of the Virgo field, at high
galactic latitude and with a low and rather uniform background, in which
several sources are detected.Comment: 10 pages, 7 figures. Accepted for publication in MNRA
Use, tolerability, benefits and side effects of orthotic devices in Charcot-Marie-Tooth disease
Background: Shoe inserts, orthopaedic shoes, ankle-foot orthoses (AFOs) are important devices in Charcot-Marie-Tooth disease (CMT) management, but data about use, benefits and tolerance are scanty. Methods: We administered to Italian CMT Registry patients an online ad hoc questionnaire investigating use, complications and perceived benefit/tolerability/emotional distress of shoe inserts, orthopaedic shoes, AFOs and other orthoses/aids. Patients were also asked to fill in the Quebec User Evaluation of Satisfaction with assistive Technology questionnaire, rating satisfaction with currently used AFO and related services. Results: We analysed answers from 266 CMT patients. Seventy per cent of subjects were prescribed lower limb orthoses, but 19% did not used them. Overall, 39% of subjects wore shoe inserts, 18% orthopaedic shoes and 23% AFOs. Frequency of abandonment was high: 24% for shoe inserts, 28% for orthopaedic shoes and 31% for AFOs. Complications were reported by 59% of patients and were more frequently related to AFOs (69%). AFO users experienced greater emotional distress and reduced tolerability as compared with shoe inserts (p<0.001) and orthopaedic shoes (p=0.003 and p=0.045, respectively). Disease severity, degree of foot weakness, customisation and timing for customisation were determinant factors in AFOs' tolerability. Quality of professional and follow-up services were perceived issues. Conclusions: The majority of CMT patients is prescribed shoe inserts, orthopaedic shoes and/or AFOs. Although perceived benefits and tolerability are rather good, there is a high rate of complications, potentially inappropriate prescriptions and considerable emotional distress, which reduce the use of AFOs. A rational, patient-oriented and multidisciplinary approach to orthoses prescription must be encouraged
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