2,792 research outputs found
pyLCSIM: X-ray lightcurves simulator
pyLCSIM simulates X-ray lightcurves from coherent signals and power spectrum models. Coherent signals can be specified as a sum of one or more sinusoids, each with its frequency, pulsed fraction and phase shift; or as a series of harmonics of a fundamental frequency (each with its pulsed fraction and phase shift). Power spectra can be simulated from a model of the power spectrum density (PSD) using as a template one or more of the built-in library functions. The user can also define his/her custom models. Models are additive
Correlation methods for the analysis of X-ray polarimetric signals
X-ray polarimetric measurements are based on studying the distribution of the
directions of scattered photons or photoelectrons and on the search of a
sinusoidal modulation with a period of {\pi}. We developed two tools for
investigating these angular distributions based on the correlations between
counts in phase bins separated by fixed phase distances. In one case we use the
correlation between data separated by half of the bin number (one period) which
is expected to give a linear pattern. In the other case, the scatter plot
obtained by shifting by 1/8 of the bin number (1/4 of period) transforms the
sinusoid in a circular pattern whose radius is equal to the amplitude of the
modulation. For unpolarized radiation these plots are reduced to a random point
distribution centred at the mean count level. This new methods provide direct
visual and simple statistical tools for evaluating the quality of polarization
measurements and for estimating the polarization parameters. Furthermore they
are useful for investigating distortions due to systematic effects
RAN Functional Splits in NTN: Architectures and Challenges
While 5G networks are already being deployed for commercial applications,
Academia and industry are focusing their effort on the development and
standardization of the next generations of mobile networks, i.e., 5G-Advance
and 6G. Beyond 5G networks will revolutionize communications systems providing
seamless connectivity, both in time and in space, to a unique ecosystem
consisting of the convergence of the digital, physical, and human domains. In
this scenario, NonTerrestrial Networks (NTN) will play a crucial role by
providing ubiquitous, secure, and resilient infrastructure fully integrated
into the overall system. The additional network complexity introduced by the
third dimension of the architecture requires the interoperability of different
network elements, enabled by the disaggregation and virtualization of network
components, their interconnection by standard interfaces and orchestration by
data-driven network artificial intelligence. The disaggregation paradigm
foresees the division of the radio access network in different virtualized
block of functions, introducing the concept of functional split. Wisely
selecting the RAN functional split is possible to better exploit the system
resources, obtaining costs saving, and to increase the system performances. In
this paper, we firstly provide a discussion of the current 6G NTN development
in terms of architectural solutions and then, we thoroughly analyze the impact
of the typical NTN channel impairments on the available functional splits.
Finally, the benefits of introducing the dynamic optimization of the functional
split in NTN are analyzed, together with the foreseen challenges
Basal cell carcinoma: 10-year experience with electrochemotherapy
BACKGROUND: Electrochemotherapy (ECT), by combining manageable cytotoxic agents with short electric pulses, represents an effective palliative skin-directed therapy. The accumulated evidence indicates that ECT stands out as a safe and well-tolerated alternative treatment for patients with multiple or large basal cell carcinoma (BCC), who are not suitable for conventional treatments. However, long-term data and shared indications are lacking.
METHODS: In this observational study, we retrospectively analyzed 84 prospectively collected patients with multiple, recurrent or locally advanced BCC who were not candidate for standard therapies and received bleomycin-based ECT according to the European Standard Operative Procedures of ECT, from 2006 to 2016.
RESULTS: Disease extent was local, locally advanced and metastatic in 40 (48%), 41 (49%) and 3 (3%), respectively. Forty-four (52%) individuals had multiple BCCs. Grade 3 skin toxicity after ECT was observed in 6% of cases. Clearance rate was 50% (95% CI 39-61%). Primary presentation (p = 0.004), tumor size <3 cm (p < 0.001), well-defined borders (p = 0.021), absence of tumor ulceration (p = 0.001), non-aggressive BCC histology (p = 0.046) and age 6469 years were associated with higher complete response rate. In patients with local BCC, the clearance rate was 72.5 and 85% after one or two ECT cycles, respectively. In the laBCC group, 32 patients (78%) achieved an objective response. Five-year recurrence rate for local and laBCC was 20 and 38%, respectively (p 64 0.001).
CONCLUSIONS: One or two ECT cycles with bleomycin may be a valuable palliative treatment in well-selected patients with multiple BCCs and favorable tumor features. Validation of predictive factors will be imperative to match patients with optimal ECT treatment modalities. Management of laBCC with ECT warrants further investigation. Trial registration ISRCTN14633165 Registered 24 March 2017 (retrospectively registered)
Gamma-ray burst observations with new generation imaging atmospheric Cerenkov Telescopes in the FERMI era
After the launch and successful beginning of operations of the FERMI
satellite, the topics related to high-energy observations of gamma-ray bursts
have obtained a considerable attention by the scientific community.
Undoubtedly, the diagnostic power of high-energy observations in constraining
the emission processes and the physical conditions of gamma-ray burst is
relevant. We briefly discuss how gamma-ray burst observations with ground-based
imaging array Cerenkov telescopes, in the GeV-TeV range, can compete and
cooperate with FERMI observations, in the MeV-GeV range, to allow researchers
to obtain a more detailed and complete picture of the prompt and afterglow
phases of gamma-ray bursts.Comment: 9 pages, two figures. Proceeding for the 6th "Science with the New
Generation of High Energy Gamma-Ray Experiments" worksho
A MST catalogue of γ-ray source candidates above 10 GeV and at Galactic latitudes higher than 20°
We describe a catalogue of γ-ray source candidates selected using the minimum spanning tree (MST) algorithm on the nine year Fermi-LAT sky (Pass 8) at energies higher than 10 GeV. The extragalactic sky at absolute Galactic latitudes above 20° has been investigated using rather restrictive selection criteria, resulting in a total sample of 1342 sources. Of these, 249 are new detections that have not been previously associated with γ-ray catalogues. A large portion of these candidates have interesting counterparts, which are most likely blazars. In this paper, we report the main results of the catalogue selection and search of counterparts. The catalogue is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/619/A2
Two new catalogs of blazar candidates in the WISE infrared sky
We present two catalogs of radio-loud candidate blazars whose WISE
mid-infrared colors are selected to be consistent with the colors of confirmed
gamma-ray emitting blazars. The first catalog is the improved and expanded
release of the WIBRaLS catalog presented by D'Abrusco et al. (2014): it
includes sources detected in all four WISE filters, spatially cross-matched
with radio source in one of three radio surveys and radio-loud based on their
q22 spectral parameter. WIBRaLS2 includes 9541 sources classified as BL Lacs,
FSRQs or mixed candidates based on their WISE colors. The second catalog,
called KDEBLLACS, based on a new selection technique, contains 5579 candidate
BL Lacs extracted from the population of WISE sources detected in the first
three WISE passbands ([3.4], [4.6] and [12]) only, whose mid-infrared colors
are similar to those of confirmed, gamma-ray BL Lacs. KDBLLACS members area
also required to have a radio counterpart and be radio-loud based on the
parameter q12, defined similarly to q22 used for the WIBRaLS2. We describe the
properties of these catalogs and compare them with the largest samples of
confirmed and candidate blazars in the literature. We crossmatch the two new
catalogs with the most recent catalogs of gamma-ray sources detected by Fermi
LAT instrument. Since spectroscopic observations of candidate blazars from the
first WIBRaLS catalog within the uncertainty regions of gamma-ray unassociated
sources confirmed that ~90% of these candidates are blazars, we anticipate that
these new catalogs will play again an important role in the identification of
the gamma-ray sky.Comment: 20 pages, 7 figures. Accepted for publication in The Astrophysical
Journal Supplement Serie
- …