1,914 research outputs found
SKA Weak Lensing II: Simulated Performance and Survey Design Considerations
We construct a pipeline for simulating weak lensing cosmology surveys with
the Square Kilometre Array (SKA), taking as inputs telescope sensitivity
curves; correlated source flux, size and redshift distributions; a simple
ionospheric model; source redshift and ellipticity measurement errors. We then
use this simulation pipeline to optimise a 2-year weak lensing survey performed
with the first deployment of the SKA (SKA1). Our assessments are based on the
total signal-to-noise of the recovered shear power spectra, a metric that we
find to correlate very well with a standard dark energy figure of merit. We
first consider the choice of frequency band, trading off increases in number
counts at lower frequencies against poorer resolution; our analysis strongly
prefers the higher frequency Band 2 (950-1760 MHz) channel of the SKA-MID
telescope to the lower frequency Band 1 (350-1050 MHz). Best results would be
obtained by allowing the centre of Band 2 to shift towards lower frequency,
around 1.1 GHz. We then move on to consider survey size, finding that an area
of 5,000 square degrees is optimal for most SKA1 instrumental configurations.
Finally, we forecast the performance of a weak lensing survey with the second
deployment of the SKA. The increased survey size (3\,steradian) and
sensitivity improves both the signal-to-noise and the dark energy metrics by
two orders of magnitude.Comment: 15 pages, 11 figures, 1 table. Comments welcome. Updated to match
published versio
SKA Weak Lensing III: Added Value of Multi-Wavelength Synergies for the Mitigation of Systematics
In this third paper of a series on radio weak lensing for cosmology with the
Square Kilometre Array, we scrutinise synergies between cosmic shear
measurements in the radio and optical/near-IR bands for mitigating systematic
effects. We focus on three main classes of systematics: (i) experimental
systematic errors in the observed shear; (ii) signal contamination by intrinsic
alignments; and (iii) systematic effects due to an incorrect modelling of
non-linear scales. First, we show that a comprehensive, multi-wavelength
analysis provides a self-calibration method for experimental systematic
effects, only implying <50% increment on the errors on cosmological parameters.
We also illustrate how the cross-correlation between radio and optical/near-IR
surveys alone is able to remove residual systematics with variance as large as
0.00001, i.e. the same order of magnitude of the cosmological signal. This also
opens the possibility of using such a cross-correlation as a means to detect
unknown experimental systematics. Secondly, we demonstrate that, thanks to
polarisation information, radio weak lensing surveys will be able to mitigate
contamination by intrinsic alignments, in a way similar but fully complementary
to available self-calibration methods based on position-shear correlations.
Lastly, we illustrate how radio weak lensing experiments, reaching higher
redshifts than those accessible to optical surveys, will probe dark energy and
the growth of cosmic structures in regimes less contaminated by non-linearities
in the matter perturbations. For instance, the higher-redshift bins of radio
catalogues peak at z~0.8-1, whereas their optical/near-IR counterparts are
limited to z<0.5-0.7. This translates into having a cosmological signal 2 to 5
times less contaminated by non-linear perturbations.Comment: 16 pages, 10 figures, 2 tables; improved discussion of experimental
systematics in Sec. 2; updated to match published versio
Green synthesis of vanillin: Pervaporation and dialysis for process intensification in a membrane reactor
In the present work, two different membrane processes (pervaporation and dialysis) are compared in view of their utilization in a membrane reactor, where vanillin, which is probably the most important aroma of the food industry, is synthesized in a green and sustainable way. The utilized precursor (ferulic acid, which is possibly a natural product from agricultural wastes) is partially oxidized (photocatalytically or biologically) and the product is continuously recovered from the reacting solution by the membrane process to avoid its degradation. It is observed that pervaporation is much more selective towards vanillin than dialysis, but the permeate flux of dialysis is much higher. Furthermore, dialysis can work also at lower temperatures and can be used to continuously restore the consumed substrate into the reacting mixture. A mathematical model of the integrated process (reaction combined with membrane separation) reproduces quite satisfactorily the experimental results and can be used for the analysis and the design of the process
Vineyard Age Effect on Juice Chemistry, Anthocyanins, and Total Phenolics
Grapevines (cv Zinfandel) planted in the same vineyard 100 years apart were analyzed for juice chemistry and phenolic content of the fruit. The vineyard was dry farmed, and vines from the original 1890 vineyard were compared to vines inter-planted in 1990. As “old vine” wines can command higher prices in the market due to a perceived difference in fruit characteristics. This study attempted to observe if there was a measurable difference in fruit characteristics, or if it is simply an effective marketing strategy. There has been little research conducted in the wine industry attempting to observe a difference of old vs young vines, and to the validity of marketing of “old vine” wines due to differences in fruit composition. Results from the study showed no significant difference in the analysis of fruit from vines planted in 1890 and vines planted in 1990 in regard to phenolic concentration, and juice chemistry. While it has proven to be an effective marketing strategy, these results do not validate the marketing of “old vine” wines based on being more concentrated or different in the variables measured in this study
Estimating the weak-lensing rotation signal in radio cosmic shear surveys
Weak lensing has become an increasingly important tool in cosmology and the
use of galaxy shapes to measure cosmic shear has become routine. The
weak-lensing distortion tensor contains two other effects in addition to the
two components of shear: the convergence and rotation. The rotation mode is not
measurable using the standard cosmic shear estimators based on galaxy shapes,
as there is no information on the original shapes of the images before they
were lensed. Due to this, no estimator has been proposed for the rotation mode
in cosmological weak-lensing surveys, and the rotation mode has never been
constrained. Here, we derive an estimator for this quantity, which is based on
the use of radio polarisation measurements of the intrinsic position angles of
galaxies. The rotation mode can be sourced by physics beyond CDM, and
also offers the chance to perform consistency checks of CDM and of
weak-lensing surveys themselves. We present simulations of this estimator and
show that, for the pedagogical example of cosmic string spectra, this estimator
could detect a signal that is consistent with the constraints from Planck. We
examine the connection between the rotation mode and the shear -modes and
thus how this estimator could help control systematics in future radio
weak-lensing surveys
Evidence of cross-correlation between the CMB lensing and the gamma-ray sky
We report the measurement of the angular power spectrum of cross-correlation
between the unresolved component of the Fermi-LAT gamma-ray sky-maps and the
CMB lensing potential map reconstructed by the Planck satellite. The matter
distribution in the Universe determines the bending of light coming from the
last scattering surface. At the same time, the matter density drives the growth
history of astrophysical objects, including their capability at generating
non-thermal phenomena, which in turn give rise to gamma-ray emissions. The
Planck lensing map provides information on the integrated distribution of
matter, while the integrated history of gamma-ray emitters is imprinted in the
Fermi-LAT sky maps. We report here the first evidence of their correlation. We
find that the multipole dependence of the cross-correlation measurement is in
agreement with current models of the gamma-ray luminosity function for AGN and
star forming galaxies, with a statistical evidence of 3.0. Moreover,
its amplitude can in general be matched only assuming that these extra-galactic
emitters are also the bulk contribution of the measured isotopic gamma-ray
background (IGRB) intensity. This leaves little room for a big contribution
from galactic sources to the IGRB measured by Fermi-LAT, pointing toward a
direct evidence of the extragalactic origin of the IGRB.Comment: 6 pages, 2 figures. v2: analysis updated with Planck 2015 lensing map
and 3FGL catalogue, conclusions strengthened; to appear in ApJ Letter
The effective Equation of State in Palatini cosmology
We investigate how the cosmological Equation of State can be used for
scrutinizing extended theories of gravity, in particular, the Palatini
gravity. Specifically, the approach consists, at first, in investigating the
effective Equation of State produced by a given model. Then, the inverse
problem can also be considered in view of determining which models are
compatible with a given effective Equation of State. We consider and solve some
cases and show that, for example, power-law models are (the only models)
capable of transforming barotropic Equations of State into effective barotropic
ones. Moreover, the form of Equation of State is preserved (only) for ,
as expected. In this perspective, modified Equations of State are a feature
capable of distinguishing Extended Gravity with respect to General Relativity.
We also investigate quadratic and non-homogeneous effective Equations of State
showing, in particular, that they contain the Starobinsky model and other ones.Comment: 19 page
IL COORDINAMENTO FRA AMMINISTRAZIONE COMUNITARIA DIRETTA E INDIRETTA
The research examines the relations between the direct and indirect European administration in medias res, concentrating its attention away from the framework introduced following the adoption of the Treaty of Lisbon amending the Treaty on European Union and the Treaty establishing the European Community, entered into force on 1 December 2009.
After a re-reading of the concepts of 'coordination' and 'executive function', the work reviews the procedures for exercising the executive European power updated by the treaties and some methods of coordination to which it is resorted in these first years of activities, instruments that seem to have favored complex and inefficient plots of skills in place of definitive solutions to the common work of the bureaucracy involved from the European administration. In this direction, the work analyzes, e.g., the cases of the management of structural funds, with specific reference to the Italian institution of the Agency for National Cohesion, next to punctual requests from the European Commission, and of the Agency for Cooperation between national energy regulators, particularly with respect to the this body\u2019s powers of direct administration attributed by REMIT discipline. Retrieved, finally, some considerations on the possibility of establishing Partnerships between European and national legal order based on the criteria of hierarchy and on the (new) legitimacy of the European equipment, the work concludes considering the introduction of a European regulation of the administrative procedure, for consequences of structural significance, as a useful tool for coordination between the various forms of implementing EU law
Brevi considerazioni su un non creduto conflitto tra spending rewiev e decreto inconferibilità
A fronte di un paventato contrasto tra l\u2019articolo 4, commi 4 e 5, del decreto-legge n. 95 del 2012, sulla composizione dei consigli di amministrazione delle societ\ue0 controllate o totalmente partecipate dalle pubbliche Amministrazioni, e la disciplina di recente introduzione, ad opera del decreto legislativo n. 39 del 2013, in materia di inconferibilit\ue0 e incompatibilit\ue0 di incarichi presso le medesime Amministrazioni e gli enti privati in controllo pubblico, si evidenzia una lettura coerente delle due disposizioni che consenta la nomina dei vertici e degli organi delle societ\ue0 considerate senza creare impedimenti alla gestione dell'attivit\ue0 d'impresa
Intravenous itraconazole for treating invasive pulmonary aspergillosis in neutropenic patients with acute lymphoblastic leukemia.
Aspergillus infection is associated with a high
mortality rate in immunocompromised hosts;
more effective drugs for this infection are needed.
Oral itraconazole has been studied in neutropenic
fungus-infected patients. Using a novel formulation
(intravenous) of itraconazole, we successfully
treated severe necrotizing pneumonias due to
Aspergillus species occurring during a postchemotherapy
prolonged aplastic phase in two
patients with acute lymphoblastic leukemia
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