246 research outputs found

    Il concetto di violenza nel passato e nella civilta di massa dei nostri tempi

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    In agreement with the title of this article, the essay is divided into two basic parts: one which is historical and the other philosophical. In the first part, the author examines at the beginning the classical latin etyma of the term uiolentia (uis, uiolare, uiolator, etc .. .. ). After that comes the acclaration of the philosophical concept of «violence» in Aristotle and Saint Thomas, and in continuation an indication of the application of the same concept to the field of ethics, and finally to the juridical field within classical roman law. In another sphere of considerations -ethical and political- the author points out the opinions of some characters which Plato introduces in his dialogues Gorgias and The Republic, due aboye all to the resonance which these works hace had in the history of the Western World until the present time. The subject of bloody violence, which is inherent to the action of the tyrannicide, is treated here briefly with references to the works of Cicero, John of Salisbury, Saint Thomas, Marsilius of Padua, Coluccio Salutati, Juan de Mariana, etc. Phenomena of midieval history suchaas the Crusades and the trials of the Inquisition could not be silenced in this case because both phenomena legitimized morally the use of violence directed towards infidels and heretics. The historical excursus on the topic of the legitimacy of violence in the hands of those who govern passes in successive orden, through Machiavelli, to the political literature on the areasson of state», jusnaturalism, etc ... To be underlined is the fact that since the end of the Eighteenth Century -and in an even much more important way in the realm of hegelian Idealism- the concept of violence has undergone a process of amplification as much within the field of Philosophy as within the experimental sciences: Darwin, Malthus and Hegel form the framework. This concept, which in Hegel's dialectic transformed itself into the dynamic principie of the antithesis, and which, therefore, affirmed the structure of the metaphysical movement of history, was passed on as a legacy to the successive hegelian trend, which was in itself so complex and so full of ramifications. The figure of Marx stands out in these pages not so much for his ties with the hegelian left, and with Feuerbach in particular, but rather because of one of the basic concepts of historical materialism -the struggle of the classes- which Marx underlined in his Communist Manifesto as the motivating force of history. The author then considers on the one hand the relationships which exist between the different european nationalisms of the last Century and the ones actually existing today, and, on the other, the Marxist ideology; he analyzes in passing the profound influence exercised by the Aufk/arung of the Eighteenth Century upon the deChristianization of man wrapped up first in his rationalism, and, later on, as a compensation, in new forms of religion and the cult of the world. From here on several names appear: Lenin, Stalin, Sorel, Mussolini, Hitler, etc., men who were very different one from the other and even opposed with regard to their respective political philosophies , but who set the pace for violence of a revolutionary and counter-revolutionary nature during short years or lasting decades. After a few more considerations, the first part of this essay ends with the author underlining the interest which experimental psychology and psycho-analysis have dedicated to the study of human aggressiveness and its mechanisms. In the second part of this work the author tries to establish gUidelines for the study of the relationships between the multiple phenomena of individual and collective violence in the present, and the mass civilization of our time. In the first place, the author makes a series of admonitions with relation to the words used: «violence-, .mass civilization- instead of «tnass society-, «civilization- instead ot «culture-, etc. He also recommends the need for not classifying en masse as a result of a reactionary mentality, the discontent which the intellectual contemplation of the present times produces in the observer, because if our state of animation could be termed as nothing else but «reactionary», then the same could be said to define a great part of the best literature of this Century, as well as the figurative arts of this modem age. The expression «mentality of violence- is applied in the historical context of cultural regression, from Friedrich Nietzsche to our day. After this, the author makes a summary description of the mental coordinates of massified man, as well as of certain particular features of the actual «organization- of culture, which is increasingly impregnated by political and economical ideas, in agreement with the fundamental methodology of historical materialism. The nucleus of these considerations is made up of a philosophical definition of the actual conditions of culture in Europe. This definition rests upon the conviction that the ideology of Marxism-Leninism, although it may by in a stage of partial historical modification, directs not only the political evolution of important sectors of , occidental society, but also that it has known how to model. thanks again to the coming-together of circunstances, the forma mentis of the contemporary intellectual. In the final part of the essay, the author dedicates special emphasis on the influence of Marxism upon wide sectors of modem Catholicism. He then adds several wamings in order to avoid , on the part of the reader, interpretations which might be inopportune or false

    Kinematics of z6z\geq 6 galaxies from [CII] line emission

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    We study the kinematical properties of galaxies in the Epoch of Reionization via the [CII] 158μ\mum line emission. The line profile provides information on the kinematics as well as structural properties such as the presence of a disk and satellites. To understand how these properties are encoded in the line profile, first we develop analytical models from which we identify disk inclination and gas turbulent motions as the key parameters affecting the line profile. To gain further insights, we use "Althaea", a highly-resolved (30pc30\, \rm pc) simulated prototypical Lyman Break Galaxy, in the redshift range z=67z = 6-7, when the galaxy is in a very active assembling phase. Based on morphology, we select three main dynamical stages: I) Merger , II) Spiral Disk, and III) Disturbed Disk. We identify spectral signatures of merger events, spiral arms, and extra-planar flows in I), II), and III), respectively. We derive a generalised dynamical mass vs. [CII]-line FWHM relation. If precise information on the galaxy inclination is (not) available, the returned mass estimate is accurate within a factor 22 (44). A Tully-Fisher relation is found for the observed high-zz galaxies, i.e. L[CII](FWHM)1.80±0.35L_{\rm[CII]}\propto (FWHM)^{1.80\pm 0.35} for which we provide a simple, physically-based interpretation. Finally, we perform mock ALMA simulations to check the detectability of [CII]. When seen face-on, Althaea is always detected at >5σ> 5\sigma; in the edge-on case it remains undetected because the larger intrinsic FWHM pushes the line peak flux below detection limit. This suggests that some of the reported non-detections might be due to inclination effects.Comment: 14 pages, 12 figures, accepted for publication in MNRA

    Deep into the structure of the first galaxies: SERRA views

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    We study the formation and evolution of a sample of Lyman Break Galaxies in the Epoch of Reionization by using high-resolution (10pc\sim 10 \,{\rm pc}), cosmological zoom-in simulations part of the SERRA suite. In SERRA, we follow the interstellar medium (ISM) thermo-chemical non-equilibrium evolution, and perform on-the-fly radiative transfer of the interstellar radiation field (ISRF). The simulation outputs are post-processed to compute the emission of far infrared lines ([CII], [NII], and [OIII]). At z=8z=8, the most massive galaxy, `Freesia', has an age t409Myrt_\star \simeq 409\,{\rm Myr}, stellar mass M4.2×109MM_{\star} \simeq 4.2\times 10^9 {\rm M}_{\odot}, and a star formation rate SFR11.5Myr1{\rm SFR} \simeq 11.5\,{\rm M}_{\odot}{\rm yr}^{-1}, due to a recent burst. Freesia has two stellar components (A and B) separated by 2.5kpc\simeq 2.5\, {\rm kpc}; other 11 galaxies are found within 56.9±21.6kpc56.9 \pm 21.6 \, {\rm kpc}. The mean ISRF in the Habing band is G=7.9G0G = 7.9\, G_0 and is spatially uniform; in contrast, the ionisation parameter is U=22+20×103U = 2^{+20}_{-2} \times 10^{-3}, and has a patchy distribution peaked at the location of star-forming sites. The resulting ionising escape fraction from Freesia is fesc2%f_{\rm esc}\simeq 2\%. While [CII] emission is extended (radius 1.54 kpc), [OIII] is concentrated in Freesia-A (0.85 kpc), where the ratio Σ[OIII]/Σ[CII]10\Sigma_{\rm [OIII]}/\Sigma_{\rm [CII]} \simeq 10. As many high-zz galaxies, Freesia lies below the local [CII]-SFR relation. We show that this is the general consequence of a starburst phase (pushing the galaxy above the Kennicutt-Schmidt relation) which disrupts/photodissociates the emitting molecular clouds around star-forming sites. Metallicity has a sub-dominant impact on the amplitude of [CII]-SFR deviations.Comment: 22 pages, 14 figures, accepted by MNRA

    ALMA hints at the presence of turbulent disk galaxies at z > 5

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    High-redshift galaxies are expected to be more turbulent than local galaxies because of their smaller size and higher star formation and thus stronger feedback from star formation, frequent mergers events, and gravitational instabilities. However, this scenario has recently been questioned by the observational evidence of a few galaxies at z~4-5 with a gas velocity dispersion similar to what is observed in the local population. Our goal is to determine whether galaxies in the first Gyrs of the Universe have already formed a dynamically cold rotating disk similar to the local counterparts. We studied the gas kinematic of 22 main-sequence star-forming galaxies at z > 5 and determined their dynamical state by estimating the ratio of the rotational velocity and of the gas velocity dispersion. We mined the ALMA archive and exploited the [CII] and [OIII] observations to perform a kinematic analysis of the cold and warm gas of z>5 main-sequence galaxies. The gas kinematics of the high-z galaxies is consistent within the errors with rotating but turbulent disks. We infer a velocity dispersion that is systematically higher by 4 times than the local galaxy population and the z~5 dust-obscured galaxies reported in the literature. The difference between our results and those reported at similar redshift can be ascribed to the systematic difference in the galaxy properties in the two samples: the disks of massive dusty galaxies are dynamically colder than the disks of dust-poor galaxies. The comparison with the theoretical predictions suggests that the main driver of the velocity dispersion in high-z galaxies is the gravitational energy that is released by the transport of mass within the disk. Finally, we stress that future deeper ALMA high-angular resolution observations are crucial to constrain the kinematic properties of high-z galaxies and to distinguish rotating disks from kpc-scale mergers.Comment: 14 pages, 11 figures, 1 tables, accepted for publication in A&

    Early galaxy growth: mergers or gravitational instability?

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    We investigate the spatially-resolved morphology of galaxies in the early Universe. We consider a typical redshift z = 6 Lyman Break galaxy, "Althaea" from the SERRA hydrodynamical simulations. We create mock rest-frame ultraviolet, optical, and far-infrared observations, and perform a two-dimensional morphological analysis to de-blend the galaxy disk from substructures (merging satellites or star-forming regions). We find that the [CII]158um emitting region has an effective radius 1.5 - 2.5 times larger than the optical one, consistent with recent observations. This [CII] halo in our simulated galaxy arises as the joint effect of stellar outflows and carbon photoionization by the galaxy UV field, rather than from the emission of unresolved nearby satellites. At the typical angular resolution of current observations (> 0.15") only merging satellites can be detected; detection of star-forming regions requires resolutions of < 0.05". The [CII]-detected satellite has a 2.5 kpc projected distance from the galaxy disk, whereas the star-forming regions are embedded in the disk itself (distance < 1 kpc). This suggests that multi-component systems reported in the literature, which have separations > 2 kpc, are merging satellites, rather than galactic substructures. Finally, the star-forming regions found in our mock maps follow the local L[CII] - SFR_UV relation of galaxy disks, although sampling the low-luminosity, low-SFR tail of the distribution. We show that future JWST observations, bridging UV and [CII] datasets, will be exceptionally suited to characterize galaxy substructures thanks to their exquisite spatial resolution and sensitivity to both low-metallicity and dust-obscured regions that are bright at infrared wavelengths.Comment: Accepted for publication in MNRAS; 17 pages (plus appendix), 7 figures, 4 table

    Inhibition of Bromodomain and Extraterminal Domain (BET) Proteins by JQ1 Unravels a Novel Epigenetic Modulation to Control Lipid Homeostasis

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    The homeostatic control of lipid metabolism is essential for many fundamental physiological processes. A deep understanding of its regulatory mechanisms is pivotal to unravel prospective physiopathological factors and to identify novel molecular targets that could be employed to design promising therapies in the management of lipid disorders. Here, we investigated the role of bromodomain and extraterminal domain (BET) proteins in the regulation of lipid metabolism. To reach this aim, we used a loss-of-function approach by treating HepG2 cells with JQ1, a powerful and selective BET inhibitor. The main results demonstrated that BET inhibition by JQ1 efficiently decreases intracellular lipid content, determining a significant modulation of proteins involved in lipid biosynthesis, uptake and intracellular trafficking. Importantly, the capability of BET inhibition to slow down cell proliferation is dependent on the modulation of cholesterol metabolism. Taken together, these data highlight a novel epigenetic mechanism involved in the regulation of lipid homeostasis

    Dynamical characterization of galaxies up to z7z \sim 7

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    The characterization of the dynamical state of galaxies up to z~7 is crucial for constraining the mechanisms driving the mass assembly in the early Universe. However, it is unclear whether the data quality of current and future observations is sufficient to perform a solid dynamical analysis. This paper defines the angular resolution and S/N required for a robust characterization of the dynamical state of galaxies up to the EoR. The final aim is to help design spatially-resolved surveys targeting emission lines of primeval galaxies. We investigate the [CII]-158um emission from z~6-7 LBGs from the SERRA cosmological simulation, covering a range of dynamical states: from disks to major mergers. We create ALMA mock observations with various data quality and apply the kinematic classification methods used in the literature. These tests allow us to quantify the performances of such methods as a function of angular resolution and S/N. We find that barely-resolved observations do not allow the correct dynamical characterization of a galaxy, resulting in the misclassification of all disks in our sample. However, even when using spatially-resolved observations with data quality typical of high-z galaxies, the standard kinematic classification methods, based on the analysis of the moment maps, fail to distinguish a merger from a disk. The high angular resolution and S/N needed to apply these standard methods successfully can be achieved with current data only for a handful of bright galaxies. We propose a new classification method, called PVsplit, that quantifies the asymmetries and morphological features in position-velocity diagrams using three empirical parameters. We test PVsplit on our mock data concluding that it can predict whether a galaxy is a disk or a merger provided that S/N 10\gtrsim10, and the major axis is covered by 3\gtrsim3 independent resolution elements.Comment: Submitted to Astronomy and Astrophysics (A&A) Journal. Comments are welcom

    The dense molecular gas in the z6\rm z\sim6 QSO SDSS J231038.88+185519.7 resolved by ALMA

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    We present ALMA observations of the CO(6-5) and [CII] emission lines and the sub-millimeter continuum of the z6z\sim6 quasi-stellar object (QSO) SDSS J231038.88+185519.7. Compared to previous studies, we have analyzed a synthetic beam that is ten times smaller in angular size, we have achieved ten times better sensitivity in the CO(6-5) line, and two and half times better sensitivity in the [CII] line, enabling us to resolve the molecular gas emission. We obtain a size of the dense molecular gas of 2.9±0.52.9\pm0.5 kpc, and of 1.4±0.21.4\pm0.2 kpc for the 91.5 GHz dust continuum. By assuming that CO(6-5) is thermalized, and by adopting a CO--to--H2H_2 conversion factor αCO=0.8 M K1 (km/s)1 pc2\rm \alpha_{CO} = 0.8~ M_{\odot}~K^{-1}~ (km/s)^{-1} ~pc^{2}, we infer a molecular gas mass of M(H2)=(3.2±0.2)×1010M\rm M(H_2)=(3.2 \pm0.2) \times 10^{10}\rm M_{\odot}. Assuming that the observed CO velocity gradient is due to an inclined rotating disk, we derive a dynamical mass of Mdyn sin2(i)=(2.4±0.5)×1010 M\rm M_{dyn}~sin^2(i) = (2.4\pm0.5) \times 10^{10}~ M_{\odot}, which is a factor of approximately two smaller than the previously reported estimate based on [CII]. Regarding the central black hole, we provide a new estimate of the black hole mass based on the C~IV emission line detected in the X-SHOOTER/VLT spectrum: MBH=(1.8±0.5)×109 M\rm M_{BH}=(1.8\pm 0.5) \times 10^{9}~ M_{\odot}. We find a molecular gas fraction of μ=M(H2)/M4.4\rm \mu=M(H_2)/M^*\sim4.4, where MMdynM(H2)M(BH)\rm M^*\approx M_{dyn} - M(H_2)-M(BH). We derive a ratio vrot/σ12v_{rot}/\sigma \approx 1-2 suggesting high gas turbulence, outflows/inflows and/or complex kinematics due to a merger event. We estimate a global Toomre parameter Q0.20.5Q\sim 0.2-0.5, indicating likely cloud fragmentation. We compare, at the same angular resolution, the CO(6-5) and [CII] distributions, finding that dense molecular gas is more centrally concentrated with respect to [CII]. We find that the current BH growth rate is similar to that of its host galaxy.Comment: A&A in pres

    Butterflies as bioindicators of metal contamination

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    Anthropogenic trace metal contamination has significantly increased and has caused many hazardous consequences for the ecosystems and human health. The Terni basin valley (Central Italy) shows a heavy load of pollutants from industrial activities, while the characteristic orography structure of the valley favours air stagnation, thus limiting air pollution dispersal. The present study conducted in 2014 aimed to determine the concentration of ten metals in five species of butterflies at nine sites in the Terni valley along a 21-km-long transect, including both relatively pristine and industrial areas. At sites where soil contamination was high for a given metal, such as for chromium as in the case of site 4 (the closest to the steel plant) and for lead as in the case of site 2 (contaminated by a firing range), higher levels of contamination were observed in the tissues of butterflies. We found a correlation between soil contamination and the concentration of Cr, Al and Sr in the tissues of some species of butterflies. The sensitivity to contamination differed among the five species; in particular, Coenonympha pamphilus was generally the species that revealed the highest concentrations of all the ten trace metals at the sites closer to the industrial area. It is known that C. pamphilus is a sedentary species and that its host plants are the Poaceae, capable of accumulating high quantities of metals in their rhizosphere region, thus providing the link with soil contamination. Therefore, monitoring the metal concentration levels in butterflies might be a good indicator and a control tool of environmental quality, specifically in areas affected by high anthropogenic pollution loads linked to a specific source

    Metal Enrichment in the Reionization Epoch

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    The presence of elements heavier than helium ("metals") is of fundamental importance for a large number of astrophysical processes occurring in planet, star and galaxy formation; it also affects cosmic structure formation and evolution in several ways. Even a small amount of heavy elements can dramatically alter the chemistry of the gas, opening the path to complex molecules. Metals might enhance the ability of the gas to radiate away its thermal energy, thus favoring the formation of gravitationally bound objects; they can also condensate in a solid phase (dust grains), partly or totally blocking radiation from luminous sources. Finally, they represent useful tracers of energy deposition by stars and probe the physical properties of the environment by absorption or emission lines. Last, but certainly not least, life -- as we know it on Earth -- is tightly related to the presence of at least some of the heavy elements. In this pedagogical review I will concentrate on the connection between early metal enrichment and cosmic reionization. As we will see these two processes are intimately connected and their joint study might turn out to be fundamental in understanding the overall evolution of the Universe during the first billion years after the Big Bang, an epoch corresponding to redshifts z>6.Comment: Book chapter in Understanding the Epoch of Cosmic Reionization: Challenges and Progress, Springer International Publishing, Ed. Andrei Mesinger, ISBN 978-3-319-21956-1. arXiv admin note: text overlap with arXiv:astro-ph/0007248 by other author
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