246 research outputs found
Il concetto di violenza nel passato e nella civilta di massa dei nostri tempi
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 galaxies from [CII] line emission
We study the kinematical properties of galaxies in the Epoch of Reionization
via the [CII] 158m 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 () simulated prototypical Lyman Break Galaxy, in the redshift range , 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 (). A Tully-Fisher relation is
found for the observed high- galaxies, i.e. 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 ; 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
We study the formation and evolution of a sample of Lyman Break Galaxies in
the Epoch of Reionization by using high-resolution (),
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 , the most massive
galaxy, `Freesia', has an age , stellar mass
, and a star formation rate
, due to a recent burst.
Freesia has two stellar components (A and B) separated by ; other 11 galaxies are found within . The
mean ISRF in the Habing band is and is spatially uniform; in
contrast, the ionisation parameter is , and
has a patchy distribution peaked at the location of star-forming sites. The
resulting ionising escape fraction from Freesia is .
While [CII] emission is extended (radius 1.54 kpc), [OIII] is concentrated in
Freesia-A (0.85 kpc), where the ratio . As many high- 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
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?
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
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
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 , and the
major axis is covered by independent resolution elements.Comment: Submitted to Astronomy and Astrophysics (A&A) Journal. Comments are
welcom
The dense molecular gas in the QSO SDSS J231038.88+185519.7 resolved by ALMA
We present ALMA observations of the CO(6-5) and [CII] emission lines and the
sub-millimeter continuum of the 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 kpc, and
of kpc for the 91.5 GHz dust continuum. By assuming that CO(6-5) is
thermalized, and by adopting a CO--to-- conversion factor , we infer a molecular gas mass of
. Assuming that the
observed CO velocity gradient is due to an inclined rotating disk, we derive a
dynamical mass of , 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: . We find a molecular gas fraction of ,
where . We derive a ratio
suggesting high gas turbulence, outflows/inflows
and/or complex kinematics due to a merger event. We estimate a global Toomre
parameter , 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
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
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
- …