2,500 research outputs found
Phase transitions and stability of dynamical processes on hypergraphs
Get PDFHypergraphs naturally represent higher-order interactions, which persistently appear in social interactions, neural networks, and other natural systems. Although their importance is well recognized, a theoretical framework to describe general dynamical processes on hypergraphs is not available yet. In this paper, we derive expressions for the stability of dynamical systems defined on an arbitrary hypergraph. The framework allows us to reveal that, near the fixed point, the relevant structure is a weighted graph-projection of the hypergraph and that it is possible to identify the role of each structural order for a given process. We analytically solve two dynamics of general interest, namely, social contagion and diffusion processes, and show that the stability conditions can be decoupled in structural and dynamical components. Our results show that in social contagion process, only pairwise interactions play a role in the stability of the absorbing state, while for the diffusion dynamics, the order of the interactions plays a differential role. Our work provides a general framework for further exploration of dynamical processes on hypergraphs
Collective response to the media coverage of COVID-19 pandemic on Reddit and Wikipedia: mixed-methods analysis
Get PDFBackground: The exposure and consumption of information during epidemic outbreaks may alter risk perception, trigger behavioral changes, and ultimately affect the evolution of the disease. It is thus of the uttermost importance to map information dissemination by mainstream media outlets and public response. However, our understanding of this exposure-response dynamic during COVID-19 pandemic is still limited.
Objective: The goal of this work is to provide a characterization of media coverage and online collective response to COVID-19 pandemic in four countries: Italy, United Kingdom, United States, and Canada.
Methods: We collect a heterogeneous dataset including 227’768 online news articles and 13’448 YouTube videos published by mainstream media, 107’898 users posts and 3’829’309 comments on the social media platform Reddit, and 278’456’892 views to COVID-19 related Wikipedia pages.
Results: Our results show that public attention, quantified as users activity on Reddit and active searches on Wikipedia pages, is mainly driven by media coverage and declines rapidly, while news exposure and COVID-19 incidence remain high. Furthermore, by using an unsupervised, dynamical topic modeling approach, we show that while the attention dedicated to different topics by media and online users are in good accordance, interesting deviations emerge in their temporal patterns.
Conclusions: Overall, our findings offer an additional key to interpret public perception and response to the current global health emergency and raise questions about the effects of attention saturation on collective awareness, risk perception and thus on tendencies towards behavioural change
Michele Taruffo: el magisterio y la obra ejemplares del genial procesalista «todoterreno»
No full textThe author reflects on Michele Taruffo’s extraordinarily important contribution to the renewal of both conventional procedural law scholarship and the theoretical background of law-court professionals. Taruffo’s contribution was achieved by means of introducing to mainstream culture in those circles the necessary knowledge of the underlying epistemic dimension, which was traditionally suppressed by the strictly legal one.El autor discurre acerca de la importantísima contribución de Michele Taruffo a la renovación del procesalismo convencional y del bagaje teórico de los profesionales de la jurisdicción, mediante la incorporación a la cultura dominante en tales medios del imprescindible conocimiento de la dimensión epistémica subyacente y tradicionalmente sofocada por la propiamente jurídica
Looking for Japan in contemporary Italy
No full textPh. D.Includes bibliographical referencesIncludes vitaby Michele Monserrat
The Author Reply. Letter to the Editor
No full textThe Author reply to the Letter sent to the Editor about a previus article on low anterior resection
Analysis of the gene coding for pyruvate decarboxylase in the yeast Kluyveromyces lactis
No full textEpidemic spreading and aging in temporal networks with memory
No full textTime-varying network topologies can deeply influence dynamical processes mediated by them. Memory effects in the pattern of interactions among individuals are also known to affect how diffusive and spreading phenomena take place. In this paper we analyze the combined effect of these two ingredients on epidemic dynamics on networks. We study the susceptible-infected-susceptible (SIS) and the susceptible-infected-recovered (SIR) models on the recently introduced activity-driven networks with memory. By means of an activity-based mean-field approach, we derive, in the long-time limit, analytical predictions for the epidemic threshold as a function of the parameters describing the distribution of activities and the strength of the memory effects. Our results show that memory reduces the threshold, which is the same for SIS and SIR dynamics, therefore favoring epidemic spreading. The theoretical approach perfectly agrees with numerical simulations in the long-time asymptotic regime. Strong aging effects are present in the preasymptotic regime and the epidemic threshold is deeply affected by the starting time of the epidemics. We discuss in detail the origin of the model-dependent preasymptotic corrections, whose understanding could potentially allow for epidemic control on correlated temporal networks
Il trionfo della morte di Palermo. Un'allegoria della modernità
No full textOriginariamente collocato nel cortile dell’Ospedale Grande e Nuovo in Palazzo Sclafani, il Trionfo della morte – ora custodito nella Galleria di Palazzo Abatellis, a Palermo – è una straordinaria enciclopedia iconografica medievale e moderna, di cui non conosciamo l’autore.
Il libro di Michele Cometa è una guida all’interpretazione del tessuto narrativo di questo formidabile affresco. Le molteplici fonti pittoriche e letterarie che ne costituiscono la trama convergono nel tratteggiare – evocando la peste nera che imperversava in Europa da più di un secolo – una sorta di confutazione iconologica del retribuzionismo medievale. Le pene mondane, infatti, non sono qui più riconducibili al peccato, ma si stemperano in una melanconia tutta modernaOriginally located in the courtyard of the Great and New Hospital in Palazzo Sclafani, the Triumph of Death - now housed in the Gallery of Palazzo Abatellis, in Palermo - is an extraordinary medieval and modern iconographic encyclopedia, of which we do not know the author.
Michele Cometa's book is a guide to interpreting the narrative fabric of this formidable fresco. The multiple pictorial and literary sources that make up the plot converge in outlining - evoking the black plague that raged in Europe for more than a century - a sort of iconological refutation of medieval retribution. In fact, worldly pains are no longer attributable to sin, but are dissolved in a wholly modern melancholy
Global Misinformation Spillovers in the Vaccination Debate Before and During the COVID-19 Pandemic: Multilingual Twitter Study
Get PDFBackgroundAntivaccination views pervade online social media, fueling distrust in scientific expertise and increasing the number of vaccine-hesitant individuals. Although previous studies focused on specific countries, the COVID-19 pandemic has brought the vaccination discourse worldwide, underpinning the need to tackle low-credible information flows on a global scale to design effective countermeasures.
ObjectiveThis study aimed to quantify cross-border misinformation flows among users exposed to antivaccination (no-vax) content and the effects of content moderation on vaccine-related misinformation.
MethodsWe collected 316 million vaccine-related Twitter (Twitter, Inc) messages in 18 languages from October 2019 to March 2021. We geolocated users in 28 different countries and reconstructed a retweet network and cosharing network for each country. We identified communities of users exposed to no-vax content by detecting communities in the retweet network via hierarchical clustering and manual annotation. We collected a list of low-credibility domains and quantified the interactions and misinformation flows among no-vax communities of different countries.
ResultsThe findings showed that during the pandemic, no-vax communities became more central in the country-specific debates and their cross-border connections strengthened, revealing a global Twitter antivaccination network. US users are central in this network, whereas Russian users also became net exporters of misinformation during vaccination rollout. Interestingly, we found that Twitter’s content moderation efforts, in particular the suspension of users following the January 6 US Capitol attack, had a worldwide impact in reducing the spread of misinformation about vaccines.
ConclusionsThese findings may help public health institutions and social media platforms mitigate the spread of health-related, low-credibility information by revealing vulnerable web-based communities
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