3,389 research outputs found
Search for single sources of ultra high energy cosmic rays on the sky
In this paper, we suggest a new way to identify single bright sources of
Ultra High Energy Cosmic Rays (UHECR) on the sky, on top of background. We look
for doublets of events at the highest energies, E > 6 x 10^19 eV, and identify
low energy tails, which are deflected by the Galactic Magnetic Field (GMF). For
the sources which are detected, we can recover their angular positions on the
sky within one degree from the real ones in 68% of cases. The reconstruction of
the deflection power of the regular GMF is strongly affected by the value of
the turbulent GMF. For typical values of 4 microG near the Earth, one can
reconstruct the deflection power with 25% precision in 68% of cases.Comment: 20 pages, 10 figures. Corresponds to the version published in JCA
Idiopathic pulmonary fibrosis: From clinical trials to real-life experiences
Randomised controlled clinical trials are fundamental in medicine to develop new effective drugs and new therapeutic regimens and are the strength of evidence-based medicine. These studies allow us to avoid the repetition of misleading experiences that have been reported in the past, where drugs or associations were utilised without compelling evidence and ultimately proven to be ineffective. In recent years, randomised clinical trials have been conducted and concluded for many rare diseases, including idiopathic pulmonary fibrosis. However, clinical trials do not always reflect the real-life scenario. Patients selected for clinical trials present fewer comorbidities, they fall between certain age limits, and the severity of their disease is defined; therefore, they do not always reflect the whole of the population affected by a specific disease. These are the reasons why we also need data that mirror real-life experience. The limitations that these kind of studies present are always several and the studies should be interpreted with caution, although they can fill the important gap between efficacy and effectiveness. In this article, we will review the existing clinical data on real-life treatment of idiopathic pulmonary fibrosis
Chern-Simons-fermion model of quarks
We propose an extension of the standard model where quarks are viewed as
fermions with a ``bare'' integer (weak) hypercharge which is normalized with a
fractional part created by a quantized topological Chern-Simons configuration
of the weak gauge fields. Consistency with hypercharge patterns not included in
the standard model is shown.Comment: 4 pages, Revtex, no figure
Lensing of ultra-high energy cosmic rays in turbulent magnetic fields
We consider the propagation of ultra high energy cosmic rays through
turbulent magnetic fields and study the transition between the regimes of
single and multiple images of point-like sources. The transition occurs at
energies around , where is the distance traversed by the
CR's with electric charge in the turbulent magnetic field of root mean
square strength and coherence length . We find that above only sources located in a fraction of a few % of the sky can reach large
amplifications of its principal image or start developing multiple images. New
images appear in pairs with huge magnifications, and they remain amplified over
a significant range of energies. At decreasing energies the fraction of the sky
in which sources can develop multiple images increases, reaching about 50% for
. The magnification peaks become however increasingly narrower and for
their integrated effect becomes less noticeable. If a uniform
magnetic field component is also present it would further narrow down the
peaks, shrinking the energy range in which they can be relevant. Below some kind of scintillation regime is reached, where many demagnified
images of a source are present but with overall total magnification of order
unity. We also search for lensing signatures in the AGASA data studying
two-dimensional correlations in angle and energy and find some interesting
hints.Comment: 30 pages, 16 figures, final version with minor change
Tidal Analysis of Long Series
It is shown how M (≥5) sets of Fourier coefficients obtained from M successive Fast Fourier Transforms (FFT) of 214 tapered hourly heights can be combined to obtain the harmonic constants of the clusters of the main astronomical and shallow-water constituents and their respective satellites. It is also shown how the clusters of the shallow-water constituents are formed
On the Stability of Long Series Tidal Analyses
Fourteen analyses with a nodal cycle resolution of filtered daily values of the 'mean' sea level at Cananéia (Brazil) were worked out, with a one-year shift. The results were examined for the stability of the harmonic constants of constituents Sa, Ssa, Mm, MSf, Mf and Mtm. Simultaneous barometric pressure data were available to correct the filtered tidal heights and the analyses were worked out with and without these corrections.The general conclusion is that the harmonic constants of Sa and Ssa were not stable and that their phase lags increased in the successive analyses. The harmonic constants of the remaining long period constituents were absolutely unstable and completely unreliable. Other fourteen harmonic analyses of 10*214 hourly tidal heights were worked out, for determining the harmonic constants of constituents with higher frequencies, in the same port. The results of these analyses, with a one-year shift,were very stable and gave an excellent insight of the micro-structure of the phenomenon
Ultrahigh Energy Nuclei in the Galactic Magnetic Field
Observations are consistent with a significant fraction of heavy nuclei in
the cosmic ray flux above a few times 10^19 eV. Such nuclei can be deflected
considerably in the Galactic magnetic field, with important implications for
the search of their sources. We perform detailed simulations of heavy nuclei
propagation within recent Galactic magnetic field models. While such models are
not yet sufficiently constrained to predict deflection maps in detail, we find
general features of the distribution of (de-) magnified flux from sources.
Since in most theoretical models sources of heavy nuclei are located in the
local large scale structure of galaxies, we show examples of images of several
nearby galaxy clusters and of the supergalactic plane. Such general features
may be useful to develop efficient methods for source reconstruction from
observed ultrahigh energy cosmic ray arrival directions.Comment: 17 pages, 11 figures. Published in JCA
Pulmonary hypertension in chronic interstitial lung diseases
Pulmonary hypertension (PH) is a common complication of interstitial lung diseases (ILDs), particularly in idiopathic pulmonary fibrosis and ILD associated with connective tissue disease. However, other lung diseases, such as combined pulmonary fibrosis and emphysema syndrome, pulmonary Langerhans cell histiocytosis, and lymphangioleiomyomatosis, may also include PH in their clinical manifestations. In all of these diseases, PH is associated with reduced exercise capacity and poor prognosis. The degree of PH in ILDs is typically mild-to-moderate. However, some of these patients may develop a disproportionate increase in PH that cannot be justified solely by hypoxia and parenchymal injury: this condition has been termed "out-of-proportion" PH. The pathogenesis of PH in these diseases is various, incompletely understood and may be multifactorial. The clinical suspicion (i.e. increased dyspnoea, low diffusion capacity) and echocardiographic assessment are the first steps towards proper diagnosis of PH; however, right heart catheterisation remains the current gold standard for diagnosis of PH. At present, no specific therapies have been approved for the treatment of PH in patients with ILDs. \ua9 ERS 2013
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