Starting from December 2019 the world has faced an unprecedented health crisis caused by the new Coronavirus (COVID-19) due to the SARS-CoV-2 pathogen. Within this topic, the aim of the paper was to ...quantify the effect of mobility habits in the spread of the Coronavirus in Italy through a multiple linear regression model. Estimation results showed that mobility habits represent one of the variables that explains the number of COVID-19 infections jointly with the number of tests/day and some environmental variables (i.e. PM pollution and temperature). Nevertheless, a proximity variable to the first outbreak was also significant, meaning that the areas close to the outbreak had a higher risk of contagion, especially in the initial stage of infection (time-decay phenomena). Furthermore, the number of daily new cases was related to the trips performed three weeks before. This threshold of 21 days could be considered as a sort of positivity detection time, meaning that the mobility restrictions quarantine commonly set at 14 days, defined only according to incubation-based epidemiological considerations, is underestimated (possible delays between contagion and detection) as a containment policy and may not always contribute to effectively slowing down the spread of virus worldwide. This result is original and, if confirmed in other studies, will lay the groundwork for more effective containment of COVID-19 in countries that are still in the health emergency, as well as for possible future returns of the virus.
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•We quantify the effect of mobility habits in the spread of the Coronavirus in Italy.•Daily COVID-19 cases are directly related to the mobility habits performed 21 days before.•Population density, PM pollutant and number of tests per day have a direct relationship with the infection.•Temperature has an inverse relationship with the spread of the virus.•The areas close to the outbreak had a higher risk of contagion (time-decay phenomena).
Blockchain 3.0 applications survey Di Francesco Maesa, Damiano; Mori, Paolo
Journal of parallel and distributed computing,
April 2020, 2020-04-00, Letnik:
138
Journal Article
Recenzirano
In this paper we survey a number of interesting applications of blockchain technology not related to cryptocurrencies. As a matter of fact, after an initial period of application to cryptocurrencies ...and to the financial world, blockchain technology has been successfully exploited in many other different scenarios, where its unique features allowed the definition of innovative and sometimes disruptive solutions. In particular, this paper takes into account the following application scenarios: end-to-end verifiable electronic voting, healthcare records management, identity management systems, access control systems, decentralized notary (with a focus on intellectual property protection) and supply chain management. For each of these, we firstly analyse the problem, the related requirements and the advantages the adoption of blockchain technology might bring. Then, we present a number of relevant solutions proposed in the literature both by academia and companies.
•Survey of five selected applications Blockchain 3.0 applications.•Problem definition, Blockchain based advantages, case studies for each application.•Electronic voting, healthcare records, IM, AC, decentralized notary, supply chain.
A time to fast Di Francesco, Andrea; Di Germanio, Clara; Bernier, Michel ...
Science,
11/2018, Letnik:
362, Številka:
6416
Journal Article
Recenzirano
Odprti dostop
Nutrient composition and caloric intake have traditionally been used to devise optimized diets for various phases of life. Adjustment of meal size and frequency have emerged as powerful tools to ...ameliorate and postpone the onset of disease and delay aging, whereas periods of fasting, with or without reduced energy intake, can have profound health benefits. The underlying physiological processes involve periodic shifts of metabolic fuel sources, promotion of repair mechanisms, and the optimization of energy utilization for cellular and organismal health. Future research endeavors should be directed to the integration of a balanced nutritious diet with controlled meal size and patterns and periods of fasting to develop better strategies to prevent, postpone, and treat the socioeconomical burden of chronic diseases associated with aging.
Future wireless networks will provide high-bandwidth, low-latency, and ultra-reliable Internet connectivity to meet the requirements of different applications, ranging from virtual reality to the ...Internet of Things. To this aim, edge caching, computing, and communication (edge-C3) have emerged to bring network resources (i.e., bandwidth, storage, and computing) closer to end users. Edge-C3 improves the network resource utilization as well as the quality of experience (QoE) of end users. Recently, several video-oriented mobile applications (e.g., live content sharing, gaming, and augmented reality) have leveraged edge-C3 in diverse scenarios involving video streaming in both the downlink and the uplink. Hence, a large number of recent works have studied the implications of video analysis and streaming through edge-C3. This article presents an in-depth survey on video edge-C3 challenges and state-of-the-art solutions in next-generation wireless and mobile networks. Specifically, it includes: a tutorial on video streaming in mobile networks (e.g., video encoding and adaptive bit-rate streaming); an overview of mobile network architectures, enabling technologies, and applications for video edge-C3; video edge computing and analytics in uplink scenarios (e.g., architectures, analytics, and applications); and video edge caching, computing and communication methods in downlink scenarios (e.g., collaborative, popularity-based, and context-aware). A new taxonomy for video edge-C3 is proposed and the major contributions of recent studies are first highlighted and then systematically compared. Finally, several open problems and key challenges for future research are outlined.
Purinergic signaling, DAMPs, and inflammation Di Virgilio, Francesco; Sarti, Alba Clara; Coutinho-Silva, Robson
American Journal of Physiology: Cell Physiology,
2020-May-01, 2020-05-01, 20200501, Letnik:
318, Številka:
5
Journal Article
Recenzirano
Odprti dostop
Danger sensing is one of the most fundamental evolutionary features enabling multicellular organisms to perceive potential threats, escape from risky situations, fight actual intruders, and repair ...damage. Several endogenous molecules are used to "signal damage," currently referred to as "alarmins" or "damage-associated molecular patterns" (DAMPs), most being already present within all cells (preformed DAMPs), and thus ready to be released, and others neosynthesized following injury. Over recent years it has become overwhelmingly clear that adenosine 5'-triphosphate (ATP) is a ubiquitous and extremely efficient DAMP (thus promoting inflammation), and its main metabolite, adenosine, is a strong immunosuppressant (thus dampening inflammation). Extracellular ATP ligates and activates the P2 purinergic receptors (P2Rs) and is then degraded by soluble and plasma membrane ecto-nucleotidases to generate adenosine acting at P1 purinergic receptors (P1Rs). Extracellular ATP, P2Rs, ecto-nucleotidases, adenosine, and P1Rs are basic elements of the purinergic signaling network and fundamental pillars of inflammation.
One of the biggest obstacles to the dissemination of fuel cells is their cost, a large part of which is due to platinum (Pt) electrocatalysts. Complete removal of Pt is a difficult if not impossible ...task for proton exchange membrane fuel cells (PEM‐FCs). The anion exchange membrane fuel cell (AEM‐FC) has long been proposed as a solution as non‐Pt metals may be employed. Despite this, few examples of Pt‐free AEM‐FCs have been demonstrated with modest power output. The main obstacle preventing the realization of a high power density Pt‐free AEM‐FC is sluggish hydrogen oxidation (HOR) kinetics of the anode catalyst. Here we describe a Pt‐free AEM‐FC that employs a mixed carbon‐CeO2 supported palladium (Pd) anode catalyst that exhibits enhanced kinetics for the HOR. AEM‐FC tests run on dry H2 and pure air show peak power densities of more than 500 mW cm−2.
Low‐cost cell: A platinum‐free alkaline membrane fuel cell employing a Pd/C‐CeO2 anode electrocatalyst produces peak power densities of more than 500 mW cm−2. Morphological analysis attests to a fine dispersion of the Pd nanoparticles accumulated mostly on the ceria part of the catalyst.
The amount of data generated by sensors, actuators, and other devices in the Internet of Things (IoT) has substantially increased in the last few years. IoT data are currently processed in the cloud, ...mostly through computing resources located in distant data centers. As a consequence, network bandwidth and communication latency become serious bottlenecks. This paper advocates edge computing for emerging IoT applications that leverage sensor streams to augment interactive applications. First, we classify and survey current edge computing architectures and platforms, then describe key IoT application scenarios that benefit from edge computing. Second, we carry out an experimental evaluation of edge computing and its enabling technologies in a selected use case represented by mobile gaming. To this end, we consider a resource-intensive 3-D application as a paradigmatic example and evaluate the response delay in different deployment scenarios. Our experimental results show that edge computing is necessary to meet the latency requirements of applications involving virtual and augmented reality. We conclude by discussing what can be achieved with current edge computing platforms and how emerging technologies will impact on the deployment of future IoT applications.
•Integration of a traditional Access Control System with blockchain technology.•A proven auditable blockchain based Access Control System.•Implementation of a general XACML Access Control System ...through smart contracts.•Proof of concept implementation and testing of the proposed blockchain based Access Control System.
This work proposes to exploit blockchain technology to define Access Control systems that guarantee the auditability of access control policies evaluation. The key idea of our proposal is to codify attribute-based Access Control policies as smart contracts and deploy them on a blockchain, hence transforming the policy evaluation process into a completely distributed smart contract execution. Not only the policies, but also the attributes required for their evaluation are managed by smart contracts deployed on the blockchain. The auditability property derives from the immutability and transparency properties of blockchain technology. This paper not only presents the proposed Access Control system in general, but also its application to the innovative reference scenario where the resources to be protected are themselves smart contracts. To prove the feasibility of our approach, we present a reference implementation exploiting XACML policies and Solidity written smart contracts deployed on the Ethereum blockchain. Finally, we evaluate the system performances through a set of experimental results, and we discuss the advantages and drawbacks of our proposal.
Aims.
More than 20 years ago, the existence of stable white dwarfs with a core of strange quark matter was proposed. More recently, via the study of radial modes, it has been concluded instead that ...such objects are unstable. We aim to clarify this issue.
Methods.
We investigated the stability of these objects by looking at their radial oscillations while incorporating boundary conditions at the quark–hadron interface, which correspond to either a rapid or a slow conversion of hadrons into quarks.
Results.
Our analysis shows that objects of this type are stable if the star is not strongly perturbed and ordinary matter cannot transform into strange quark matter because of the Coulomb barrier separating the two components. On the other hand, ordinary matter can be transformed into strange quark matter if the star undergoes a violent process, as in the preliminary stages of a type Ia supernova, and this causes the system to become unstable and collapse into a strange quark star. In this way, the accretion-induced collapse of strange dwarfs can be facilitated, and kilometre-sized objects with sub-solar masses can be produced.
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