46 research outputs found
The Macerata Shooting: Digital Movements of Opinion in the Hybrid Media System
The role of Twitter in the organisation of political action – either by supporting existing street-level protests or native digital mobilizations – has attracted a great deal of attention. However, the wider media, political, and cultural context in which mobilizations take place is often overlooked. In this article, we analyse the trajectory of a digital movement of opinion that reacted to the shooting of black people by a right-wing militant in the Italian town of Macerata in 2018. Using a dataset of 571,996 tweets captured over 31 days, and employing a mix of machine learning, network analysis and qualitative investigation, we study how factors both external and internal to the platform sealed the fate of that movement. We maintain that the permeability of Twitter to outer divided arenas and its re-intermediation by political leaders are key to the transformation of protest movements into polarised crowds
The Macerata Shooting: Digital Movements of Opinion in the Hybrid Media System
The role of Twitter in the organisation of political action – either by supporting existing street-level protests or native digital mobilizations – has attracted a great deal of attention. However, the wider media, political, and cultural context in which mobilizations take place is often overlooked. In this article, we analyse the trajectory of a digital movement of opinion that reacted to the shooting of black people by a right-wing militant in the Italian town of Macerata in 2018. Using a dataset of 571,996 tweets captured over 31 days, and employing a mix of machine learning, network analysis and qualitative investigation, we study how factors both external and internal to the platform sealed the fate of that movement. We maintain that the permeability of Twitter to outer divided arenas and its re-intermediation by political leaders are key to the transformation of protest movements into polarised crowds
Search for flow invariants in even and odd dimensions
A flow invariant in quantum field theory is a quantity that does not depend
on the flow connecting the UV and IR conformal fixed points. We study the flow
invariance of the most general sum rule with correlators of the trace Theta of
the stress tensor. In even (four and six) dimensions we recover the results
known from the gravitational embedding. We derive the sum rules for the trace
anomalies a and a' in six dimensions. In three dimensions, where the
gravitational embedding is more difficult to use, we find a non-trivial
vanishing relation for the flow integrals of the three- and four-point
functions of Theta. Within a class of sum rules containing finitely many terms,
we do not find a non-vanishing flow invariant of type a in odd dimensions. We
comment on the implications of our results.Comment: 21 pages, v2: expanded introduction, published in NJ
Ergodic transition in a simple model of the continuous double auction
We study a phenomenological model for the continuous double auction, whose aggregate order process is equivalent to two independent M/M/1 queues. The continuous double auction defines a continuous-time random walk for trade prices. The conditions for ergodicity of the auction are derived and, as a consequence, three possible regimes in the behavior of prices and logarithmic returns are observed. In the ergodic regime, prices are unstable and one can observe a heteroskedastic behavior in the logarithmic returns. On the contrary, non-ergodicity triggers stability of prices, even if two different regimes can be seen
DANKMEMES @ EVALITA 2020: The Memeing of Life: Memes, Multimodality and Politics
DANKMEMES is a shared task proposed for the 2020 EVALITA campaign, focusing on the automatic classification of Internet memes. Providing a corpus of 2.361 memes on the 2019 Italian Government Crisis, DANKMEMES features three tasks: A) Meme Detection, B) Hate Speech Identification, and C) Event Clustering. Overall, 5 groups took part in the first task, 2 in the second and 1 in the third. The best system was proposed by the UniTor group and achieved a F1 score of 0.8501 for task A, 0.8235 for task B and 0.2657 for task C. In this report, we describe how the task was set up, we report the system results and we discuss them
On the assertion that PCT violation implies Lorentz non-invariance
Out of conviction or expediency, some current research programs take for
granted that "PCT violation implies violation of Lorentz invariance". We point
out that this claim is still on somewhat shaky ground. In fact, for many years
there has been no strengthening of the evidence in this direction. However,
using causal perturbation theory, we prove here that when starting with a local
PCT-invariant interaction, PCT symmetry can be maintained in the process of
renormalization.Comment: 13 page
Charge separation: From the topology of molecular electronic transitions to the dye/semiconductor interfacial energetics and kinetics
Charge separation properties, that is the ability of a chromophore, or a
chromophore/semiconductor interface, to separate charges upon light absorption,
are crucial characteristics for an efficient photovoltaic device. Starting from
this concept, we devote the first part of this book chapter to the topological
analysis of molecular electronic transitions induced by photon capture. Such
analysis can be either qualitative or quantitative, and is presented here in
the framework of the reduced density matrix theory applied to single-reference,
multiconfigurational excited states. The qualitative strategies are separated
into density-based and wave function-based approaches, while the quantitative
methods reported here for analysing the photoinduced charge transfer nature are
either fragment-based, global or statistical. In the second part of this
chapter we extend the analysis to dye-sensitized metal oxide surface models,
discussing interfacial charge separation, energetics and electron injection
kinetics from the dye excited state to the semiconductor conduction band
states
Una complessa eredità : ricordando Fabrizio Frasnedi (1944-2015)
Il volume raccoglie una serie di contributi in ricordo di Fabrizio Frasnedi a cinque anni dalla sua scomparsa.
Interventi di Gian Mario Anselmi, Bruno Capaci, Maria Rosaria Catino, Guido Conti, Cristiana De Santis, Yahis Martari, Chiara Panzieri, Michele Prandi, Rocco Ronchi, Alberto Sebastiani, Matteo Vial
Damaged Intestinal Epithelial Integrity Linked to Microbial Translocation in Pathogenic Simian Immunodeficiency Virus Infections
The chronic phase of HIV infection is marked by pathological activation of the immune system, the extent of which better predicts disease progression than either plasma viral load or CD4+ T cell count. Recently, translocation of microbial products from the gastrointestinal tract has been proposed as an underlying cause of this immune activation, based on indirect evidence including the detection of microbial products and specific immune responses in the plasma of chronically HIV-infected humans or SIV-infected Asian macaques. We analyzed tissues from SIV-infected rhesus macaques (RMs) to provide direct in situ evidence for translocation of microbial constituents from the lumen of the intestine into the lamina propria and to draining and peripheral lymph nodes and liver, accompanied by local immune responses in affected tissues. In chronically SIV-infected RMs this translocation is associated with breakdown of the integrity of the epithelial barrier of the gastrointestinal (GI) tract and apparent inability of lamina propria macrophages to effectively phagocytose translocated microbial constituents. By contrast, in the chronic phase of SIV infection in sooty mangabeys, we found no evidence of epithelial barrier breakdown, no increased microbial translocation and no pathological immune activation. Because immune activation is characteristic of the chronic phase of progressive HIV/SIV infections, these findings suggest that increased microbial translocation from the GI tract, in excess of capacity to clear the translocated microbial constituents, helps drive pathological immune activation. Novel therapeutic approaches to inhibit microbial translocation and/or attenuate chronic immune activation in HIV-infected individuals may complement treatments aimed at direct suppression of viral replication