455 research outputs found
Un-Certainty as a Pragmatic Resource for Psychiatric Argumentation: a Diachronical and Diatextual Approach
Psychiatry is the science that aims to propose plausible theories in the description and explanation of “body-mind” pathologies. Since also the modern institution of science produces a type of discourse aimed at reducing human insecuritas through a progressive falsification of conjectures on how things are actually, it seems very important to monitor the discursive construction of un-certainty about an extremely elusive object such as the abnormality of psychic functioning. In the light of this, the present paper aims to identify what changes are traceable in the argumentative structure of un-certainty in the psychiatric scientific communication by the British Journal of Psychiatry in its life span as well as how the construction of socially “credible” authorship profiles evolves. The randomly-selected 90 articles from the 160 years of the BJP life cycle were analyzed through various interpretative apparatuses, by practicing both bottom-up and top-down approaches. Indeed, in the perspective of cultural and discursive psychology, un-certainty is a multidimensional discursive construction which is not attributable to the psycho-linguistic level of the utterance in its entirety, but to the meta-pragmatic dimension of enunciation. The identified rhetoric, which collects the groupings of enunciative profiles, sees the researcher evolving between the explorer’s attempts, the investigator’s inquiries and the critical rigor of the technician
A numerical study of the alpha model for two-dimensional magnetohydrodynamic turbulent flows
We explore some consequences of the ``alpha model,'' also called the
``Lagrangian-averaged'' model, for two-dimensional incompressible
magnetohydrodynamic (MHD) turbulence. This model is an extension of the
smoothing procedure in fluid dynamics which filters velocity fields locally
while leaving their associated vorticities unsmoothed, and has proved useful
for high Reynolds number turbulence computations. We consider several known
effects (selective decay, dynamic alignment, inverse cascades, and the
probability distribution functions of fluctuating turbulent quantities) in
magnetofluid turbulence and compare the results of numerical solutions of the
primitive MHD equations with their alpha-model counterparts' performance for
the same flows, in regimes where available resolution is adequate to explore
both. The hope is to justify the use of the alpha model in regimes that lie
outside currently available resolution, as will be the case in particular in
three-dimensional geometry or for magnetic Prandtl numbers differing
significantly from unity. We focus our investigation, using direct numerical
simulations with a standard and fully parallelized pseudo-spectral method and
periodic boundary conditions in two space dimensions, on the role that such a
modeling of the small scales using the Lagrangian-averaged framework plays in
the large-scale dynamics of MHD turbulence. Several flows are examined, and for
all of them one can conclude that the statistical properties of the large-scale
spectra are recovered, whereas small-scale detailed phase information (such as
e.g. the location of structures) is lost.Comment: 22 pages, 20 figure
Direct simulations of helical Hall-MHD turbulence and dynamo action
Direct numerical simulations of turbulent Hall dynamos are presented. The
evolution of an initially weak and small scale magnetic field in a system
maintained in a stationary turbulent regime by a stirring force at a
macroscopic scale is studied to explore the conditions for exponential growth
of the magnetic energy. Scaling of the dynamo efficiency with the Reynolds
numbers is studied, and the resulting total energy spectra are found to be
compatible with a Kolmogorov type law. A faster growth of large scale magnetic
fields is observed at intermediate intensities of the Hall effect.Comment: 13 pages, 17 figures, ApJ (in press
Multifunctional peri-urban agriculture: Some ecosystem services of a sustainable olive grove
This study reports the influence of a sustainable management model which entails the recycling of urban wastewater and distribution by drip irrigation, recycling of polygenic carbon sources internal to the olive orchard (cover crops, pruning material) on yield, soil water holding capacity, soil biodiversity. Sustainable management practices were applied for a 15-year period in a 2-ha olive orchard located in an hilly peri-urban zone of southern Italy, where olive tree represents the dominant crop and has a key role inside the traditional landscape. A comparison between sustainable and conventional management (soil tillage, burning of the pruning residues, mineral fertilization, empirical irrigation) was carried out. This study suggests some guidelines of a sustainable management of peri-urban olive groves, with benefits to the whole agro-ecosystem stability and to the near town, recognizing the multifunctional role of agriculture that enhances the creation of synergies between urban and rural areas
Not Much Helicity is Needed to Drive Large Scale Dynamos
Understanding the in situ amplification of large scale magnetic fields in
turbulent astrophysical rotators has been a core subject of dynamo theory. When
turbulent velocities are helical, large scale dynamos that substantially
amplify fields on scales that exceed the turbulent forcing scale arise, but the
minimum sufficient fractional kinetic helicity f_h,C has not been previously
well quantified. Using direct numerical simulations for a simple helical
dynamo, we show that f_h,C decreases as the ratio of forcing to large scale
wave numbers k_F/k_min increases. From the condition that a large scale helical
dynamo must overcome the backreaction from any non-helical field on the large
scales, we develop a theory that can explain the simulations. For k_F/k_min>8
we find f_h,C< 3%, implying that very small helicity fractions strongly
influence magnetic spectra for even moderate scale separation.Comment: 5 pages, 4 figure
The Humble Charisma of a White-Dressed Man in a Desert Place: Pope Francis’ Communicative Style in the Covid-19 Pandemic
The context of deep uncertainty, fear, and “social distancing” characterizing the COVID-19 pandemic has led to a need for cultural anchorages and charismatic leaders who may conjointly and effectively support human beings, strengthen their identity, and empower social commitment. In this perspective, the charismatic leadership of Pope Francis, which is widely shared not only within the religious world, may play a crucial role in facing emergency with existential reasons and psychological resources. The general aim of this work is to shed light on the communicative features of the charismatic leadership of Pope Francis during the pandemic emergency; in order to better understand his effectiveness, we analyzed both the core issues and his multimodal body signals in the global TV event of the Universal Prayer with the Urbi et Orbi Blessing. The multimodal and discursive analyses of the homily enabled us to define the “humble” charisma of the Pope, which is based upon on authentic and informal presence, manifested emotional signals (and, in particular commotion) showing features of equity and familiarity. From a discursive point of view, the common and overarching affiliation is constructed through a multiple focus on the “we” pronoun, which is constructed through socio-epistemic rhetoric. The results show how this integrated methodological perspectives, which is multimodal and discursive, may offer meaningful pathways detection of effective and persuasive signals
Waves, Coriolis force and the dynamo effect
Dynamo activity caused by waves in a rotating magneto-plasma is investigated.
In astrophysical environments such as accretion disks and at sufficiently small
spatial scales, the Hall effect is likely to play an important role. It is
shown that a combination of the Coriolis force and Hall effect can produce a
finite -effect by generating net helicity in the small scales. The
shear/ion-cyclotron normal mode of the Hall plasma is the dominant contributor
to the dynamo action for short scale motions.Comment: 8 pages, 3 figures, ApJ (in press
- …