475 research outputs found

    The revenues of local governments in the statistical register for public administrations: inequality decomposition by sources

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    During the last decade, the Italian national institute of statistics (Istat) has been engaged in a modernization program involving the revision of the statistical production model. The main goal behind this program is the use of statistical registers integrated into a single logical environment, the Italian Integrated System of Statistical Registers (ISSR), for supporting the consistency of statistical production processes and improving the quality of information for users. One object of the ISSR is the satellite statistical REgister for Public Administrations (REPA) that contains information on structural and economic variables on a subset of the Italian PA. The public institutions are different from each other in structures, dimensions, and scopes. In the present paper, these differences are analysed by looking at their revenues. For this aim, the inequality in the revenues, measured with the Gini index, is decomposed “by sources”

    Spectral signature of short attosecond pulse trains

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    We report experimental measurements of high-order harmonic spectra generated in Ar using a carrier-envelope-offset (CEO) stabilized 12 fs, 800nm laser field and a fraction (less than 10%) of its second harmonic. Additional spectral peaks are observed between the harmonic peaks, which are due to interferences between multiple pulses in the train. The position of these peaks varies with the CEO and their number is directly related to the number of pulses in the train. An analytical model, as well as numerical simulations, support our interpretation

    Efficient GW calculations via the interpolation of the screened interaction in momentum and frequency space: The case of graphene

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    The calculation of the GW self-energy may be a computational challenge due to the double convolution integrals over frequency and transferred momentum. In this work, we combine the recently developed multipole approximation (MPA) with the W-av method. MPA accurately approximates full-frequency response functions using a small number of poles, while W-av improves the convergence with respect to the Brillouin zone (BZ) sampling in 2D materials. The combination of these techniques is applied to obtain an accurate G0W0 QP band structure of graphene. The screened interaction of graphene shows a complex low-energy frequency dependence, that is poorly described with plasmon pole approximations (PPA), and a sharp q dependence of the dynamical dielectric function over momentum transfer, making standard BZ integration techniques inefficient. Within the present development, we compare the calculated QP band structure of graphene finding an excellent agreement with angle resolved photoemission spectroscopy (ARPES) measurements

    Mid Infrared Photometry of Mass-Losing AGB Stars

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    We present ground-based mid-infrared imaging for 27 M-, S- and C-type Asymptotic Giant Branch (AGB) stars. The data are compared with those of the database available thanks to the IRAS, ISO, MSX and 2MASS catalogues. Our goal is to establish relations between the IR colors, the effective temperature TeffT_{eff}, the luminosity LL and the mass loss rate MË™\dot M, for improving the effectiveness of AGB modelling. Bolometric (absolute) magnitudes are obtained through distance compilations, and by applying previously-derived bolometric corrections; the variability is also studied, using data accumulated since the IRAS epoch. The main results are: i) Values of LL and MË™\dot M for C stars fit relations previously established by us, with Miras being on average more evolved and mass losing than Semiregulars. ii) Moderate IR excesses (as compared to evolutionary tracks) are found for S and M stars in our sample: they are confirmed to originate from the dusty circumstellar environment. iii) A larger reddening characterizes C-rich Miras and post-AGBs. In this case, part of the excess is due to AGB models overestimating TeffT_{eff} for C-stars, as a consequence of the lack of suitable molecular opacities. This has a large effect on the colors of C-rich sources and sometimes disentangling the photospheric and circumstellar contributions is difficult; better model atmospheres should be used in stellar evolutionary codes for C stars. iv) The presence of a long-term variability at mid-IR wavelengths seems to be limited to sources with maximum emission in the 8 -- 20 ÎĽ\mum region, usually Mira variables (1/3 of our sample). Most Semiregular and post-AGB stars studied here remained remarkably constant in mid-IR over the last twenty years.Comment: Accepted for publication in the Astronomical Journal - 35 pages (in preprint), 9 figures, 5 table

    On the magnetic structure and wind parameter profiles of Alfven wave driven winds in late-type supergiant stars

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    Cool stars at giant and supergiant evolutionary phases present low velocity and high density winds, responsible for the observed high mass-loss rates. Although presenting high luminosities, radiation pressure on dust particles is not sufficient to explain the wind acceleration process. Among the possible solutions to this still unsolved problem, Alfven waves are, probably, the most interesting for their high efficiency in transfering energy and momentum to the wind. Typically, models of Alfven wave driven winds result in high velocity winds if they are not highly damped. In this work we determine self-consistently the magnetic field geometry and solve the momentum, energy and mass conservation equations, to demonstrate that even a low damped Alfven wave flux is able to reproduce the low velocity wind. We show that the magnetic fluxtubes expand with a super-radial factor S>30 near the stellar surface, larger than that used in previous semi-empirical models. The rapid expansion results in a strong spatial dilution of the wave flux. We obtained the wind parameter profiles for a typical supergiant star of 16 M_sun. The wind is accelerated in a narrow region, coincident with the region of high divergence of the magnetic field lines, up to 100 km/s. For the temperature, we obtained a slight decrease near the surface for low damped waves, because the wave heating mechanism is less effective than the radiative losses. The peak temperature occurs at 1.5 r_0 reaching 6000 K. Propagating outwards, the wind cools down mainly due to adiabatic expansion.Comment: to appear in the MNRA

    Structural Performance of Reinforced Concrete Flat Plate Buildings Subjected to Fire

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    El siguiente artículo se propone estudiar la poesía de Luis Hernández a partir de los problemas que surgen al intentar estudiar su obra reunida. Antes que ser valorada como una poesía “inacabada”, la deliberada asistematicidad de su poética debe ser entendida como el resultado de un calculado y consciente ejercicio artístico, cuyas fuentes filosóficas tradicionalmente han pugnado por una ontología del movimiento frente a una metafísica de la permanencia. Bajo esta perspectiva, la obra de Hernández se revela como un “plano de inmanencia”, desde el cual acontece el sentido de su poesía en el quehacer de la escritura.The article aims to study Luis Hernández’ poetry from the point of view of the problems that emerge when trying to analyze his Complete Works. Rather than being assessed as “unfinished”, the deliberate and unsystematic appearance of his poetic, should rather be understood as the result of a calculated and conscious artistic practice that stems from philosophical trends which traditionally have fostered an ontology of movement against a metaphysics of permanence. Under this view, Hernández work shows up as “plane of immanence” from where sense becomes an event for the creative writing process.El següent article es proposa estudiar la poesia de Luis Hernández a partir dels problemes que sorgeixen al tractar d’estudiar la seva obra reunida. Abans de ser valorada com una poesia “incabada”, la deliberada asistematicitat de la seva poètica deu ser entesa com el resultat d’un calculat i conscient exercici artístic, fonts filosòfiques de les quals han pugnat tradicionalment per una ontologia del moviment davant una metafísica de la permanència. Sota aquesta perspectiva, l’obra d’Hernàndez es revela com un “pla d’inmanència”, des del qual esdevé el sentit de la seva poesia en el afer de l’escriptura

    Breast milk butyrate as protective factor against food allergy

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    Conflicting evidences suggest a role for breast milk as pro- tective factor against food allergy. The major short chain fatty acids, butyrate produced by gut microbiota exerts positive effect on immune system. We aimed to see whether butyrate concen- tration in human milk is able to prevent food allergy in an animal model of cow milk allergy. Mature breast milk butyrate concentration from 40 healthy women (aged 21–42 yrs) was assessed by gas chromatography. 4- Week-old female C3H/HeOuJ mice were sensitized by oral route with -lactoglobulin (BLG, 20 mg) plus cholera toxin (CT, 10 g) as an adjuvant in the presence or absence of butyrate. Acute aller- gic skin response,anaphylactic symptom score, body temperature, intestinal permeability, anti-BLG IgE, IL-4 and IL-10 production were assessed soon after oral challenge. Mean butyrate concen- tration in breast milk was 0.75 mM (SD ± 0.15). Based on this concentration a daily dose of 30 mg/kg body weight was calculated. The same butyrate concentration was able to significantly prevent acute allergic skin response, anaphylactic symptom score, body temperature decrease, intestinal permeability increase, anti-BLG IgE, IL-4 and IL-10 production in CMA animal model (p < .05). Our data suggest a pivotal role for butyrate as an effective human milk component in food allergy prevention

    The new low-toxic histone deacetylase inhibitor S-(2) induces apoptosis in various acute myeloid leukemia cells

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    Histone deacetylase inhibitors (HDACi) induce tumour cell cycle arrest and/or apoptosis, and some of them are currently used in cancer therapy. Recently, we described a series of powerful HDACi characterized by a 1,4-benzodiazepine (BDZ) ring hybridized with a linear alkyl chain bearing a hydroxamate function as Zn(++)-chelating group. Here, we explored the anti-leukaemic properties of three novel hybrids, namely the chiral compounds (S)-2 and (R)-2, and their non-chiral analogue 4, which were first comparatively tested in promyelocytic NB4 cells. (S)-2 and partially 4– but not (R)-2 – caused G0/G1 cell-cycle arrest by up-regulating cyclin G2 and p21 expression and down-regulating cyclin D2 expression, and also apoptosis as assessed by cell morphology and cytofluorimetric assay, histone H2AX phosphorylation and PARP cleavage. Notably, these events were partly prevented by an anti-oxidant. Moreover, novel HDACi prompted p53 and α-tubulin acetylation and, consistently, inhibited HDAC1 and 6 activity. The rank order of potency was (S)-2 > 4 > (R)-2, reflecting that of other biological assays and addressing (S)-2 as the most effective compound capable of triggering apoptosis in various acute myeloid leukaemia (AML) cell lines and blasts from patients with different AML subtypes. Importantly, (S)-2 was safe in mice (up to 150 mg/kg/week) as determined by liver, spleen, kidney and bone marrow histopathology; and displayed negligible affinity for peripheral/central BDZ-receptors. Overall, the BDZ-hydroxamate (S)-2 showed to be a low-toxic HDACi with powerful anti-proliferative and pro-apototic activities towards different cultured and primary AML cells, and therefore of clinical interest to support conventional anti-leukaemic therapy

    Archiving multi-epoch data and the discovery of variables in the near infrared

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    We present a description of the design and usage of a new synoptic pipeline and database model for time series photometry in the VISTA Data Flow System (VDFS). All UKIRT-WFCAM data and most of the VISTA main survey data will be processed and archived by the VDFS. Much of these data are multi-epoch, useful for finding moving and variable objects. Our new database design allows the users to easily find rare objects of these types amongst the huge volume of data being produced by modern survey telescopes. Its effectiveness is demonstrated through examples using Data Release 5 of the UKIDSS Deep Extragalactic Survey (DXS) and the WFCAM standard star data. The synoptic pipeline provides additional quality control and calibration to these data in the process of generating accurate light-curves. We find that 0.6+-0.1% of stars and 2.3+-0.6% of galaxies in the UKIDSS-DXS with K<15 mag are variable with amplitudes \Delta K>0.015 magComment: 30 pages, 31 figures, MNRAS, in press Minor changes from previous version due to refereeing and proof-readin
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