A New Waveform Consistency Test for Gravitational Wave Inspiral Searches

Searches for binary inspiral signals in data collected by interferometric gravitational wave detectors utilize matched filtering techniques. Although matched filtering is optimal in the case of stationary Gaussian noise, data from real detectors often contains "glitches" and episodes of excess noise which cause filter outputs to ring strongly. We review the standard \chi^2 statistic which is used to test whether the filter output has appropriate contributions from several different frequency bands. We then propose a new type of waveform consistency test which is based on the time history of the filter output. We apply one such test to the data from the first LIGO science run and show that it cleanly distinguishes between true inspiral waveforms and large-amplitude false signals which managed to pass the standard \chi^2 test.Comment: 10 pages, 6 figures, submitted to Classical and Quantum Gravity for the proceedings of the Eighth Gravitational Wave Data Analysis Workshop (GWDAW-8

Blockchain-based access control management for Decentralized Online Social Networks

Online Social Networks (OSNs) represent today a big communication channel where users spend a lot of time to share personal data. Unfortunately, the big popularity of OSNs can be compared with their big privacy issues. Indeed, several recent scandals have demonstrated their vulnerability. Decentralized Online Social Networks (DOSNs) have been proposed as an alternative solution to the current centralized OSNs. DOSNs do not have a service provider that acts as central authority and users have more control over their information. Several DOSNs have been proposed during the last years. However, the decentralization of the social services requires efficient distributed solutions for protecting the privacy of users. During the last years the blockchain technology has been applied to Social Networks in order to overcome the privacy issues and to offer a real solution to the privacy issues in a decentralized system. However, in these platforms the blockchain is usually used as a storage, and content is public. In this paper, we propose a manageable and auditable access control framework for DOSNs using blockchain technology for the definition of privacy policies. The resource owner uses the public key of the subject to define auditable access control policies using Access Control List (ACL), while the private key associated with the subject's Ethereum account is used to decrypt the private data once access permission is validated on the blockchain. We provide an evaluation of our approach by exploiting the Rinkeby Ethereum testnet to deploy the smart contracts. Experimental results clearly show that our proposed ACL-based access control outperforms the Attribute-based access control (ABAC) in terms of gas cost. Indeed, a simple ABAC evaluation function requires 280,000 gas, instead our scheme requires 61,648 gas to evaluate ACL rules

Low-latency analysis pipeline for compact binary coalescences in the advanced gravitational wave detector era

The multi-band template analysis (MBTA) pipeline is a low-latency coincident analysis pipeline for the detection of gravitational waves (GWs) from compact binary coalescences. MBTA runs with a low computational cost, and can identify candidate GW events online with a sub-minute latency. The low computational running cost of MBTA also makes it useful for data quality studies. Events detected by MBTA online can be used to alert astronomical partners for electromagnetic follow-up. We outline the current status of MBTA and give details of recent pipeline upgrades and validation tests that were performed in preparation for the first advanced detector observing period. The MBTA pipeline is ready for the outset of the advanced detector era and the exciting prospects it will bring.Comment: 18 pages, 10 figure

Magnetic soft modes in the locally distorted triangular antiferromagnet alpha-CaCr2O4

In this paper we explore the phase diagram and excitations of a distorted triangular lattice antiferromagnet. The unique two-dimensional distortion considered here is very different from the 'isosceles'-type distortion that has been extensively investigated. We show that it is able to stabilize a 120{\deg} spin structure for a large range of exchange interaction values, while new structures are found for extreme distortions. A physical realization of this model is \alpha-CaCr2O4 which has 120{\deg} structure but lies very close to the phase boundary. This is verified by inelastic neutron scattering which reveals unusual roton-like minima at reciprocal space points different from those corresponding to the magnetic order.Comment: 5 pages, 3 figures and lots of spin-wave

Quantum spin chain as a potential realization of the Nersesyan-Tsvelik model

It is well established that long-range magnetic order is suppressed in magnetic systems whose interactions are low-dimensional. The prototypical example is the S-1/2 Heisenberg antiferromagnetic chain (S-1/2 HAFC) whose ground state is quantum critical. In real S-1/2 HAFC compounds interchain coupling induces long-range magnetic order although with a suppressed ordered moment and reduced N\'eel temperature compared to the Curie-Weiss temperature. Recently, it was suggested that order can also be suppressed if the interchain interactions are frustrated, as for the Nersesyan-Tsvelik model. Here, we study the new S-1/2 HAFC, (NO)[Cu(NO3)3]. This material shows extreme suppression of order which furthermore is incommensurate revealing the presence of frustration consistent with the Nersesyan-Tsvelik model

ENZYMES FROM MARINE MICROORGANISMS FOR THE PREPARATION OF BIOLOGICALLY ACTIVE MOLECULES

This PhD project focuses on the identification, isolation and characterization of new biocatalysts able to generate biologically active molecules with significant enantioselectivity. Through screening, we identified marine strains, from MaCuMBA (Marine Culturable Microorganism for Biotechnological Applications) and BIODEEP (Biotechnologies form the deep) European project collections, which show a marked enantioselectivity on intermediates of molecules of biological interest. Biotransformation substrate range included pramipexole, as main target, but it also embraces other common building blocks for synthetic industrial preparation. The stereoselective reduction of structurally different ketones using halotolerant marine yeasts (Meyerozyma guilliermondii and Rhodotorula mucilaginosa) was studied using cells grown and bio-converted in seawater. The preparation of valuable chemicals through water-saving (bio)processes based on the direct exploitation of seawater is a significant step towards sustainable biocatalysis. By choosing a suitable strain, high yields and stereoselectivity could be achieved in most cases. Notably, high chemoselectivity and enantioselectivity were observed using R. mucilaginosa in the reduction of aromatic \u3b2-ketonitriles, which allowed the recovery of the optically pure corresponding alcohols; notably, reduction with whole cells of yeasts generally give a mixture of undesired products, as observed with M. guilliermondii. Keto-reduction potential of thirty-three marine bacterium species was checked and afterwards the possibility to convert this substrate directly into the optically pure amine was investigated: marine bacteria were screened to identify transaminase activity. Based on the previous results in terms of halotolerance and transaminase activity, the marine bacterium strain Virgibacillus pantothenticus 21D was selected for the genome sequencing in order to clone and express an \u3c9-transaminase enzyme. A recombinant non-marine ketoreductase from Pichia glucozyma (KRED1-Pglu) was used for the enantioselective reduction of various cyclic ketones including pramipexole ketone intermediate. Thanks to co-factor recycling system, the purified enzyme showed very promising results. The soluble expression of a novel omega transaminase from a newly isolated halotolerant marine bacterium Virgibacillus pantothenticus was attained. Despite of several standard methodologies applied, the marine wild-type enzyme was total insoluble in E. coli host and it was satisfactorily solubilized by one single-point mutation, allowing the characterization of the new omega transaminase. The enzyme shows an interesting salt and solvent tolerance, in accordance to its origin and it results particularly active on some interesting building blocks molecules

Evaluating Posts on the Steemit Blockchain: Analysis on Topics Based on Textual Cues

Online Social Networking platforms (OSNs) are part of the people's everyday life answering the deep-rooted need for communication among humans. During recent years, a new generation of social media based on blockchain became very popular, bringing the power of the technology to the service of social networks. Steemit is one such and employs the blockchain to implement a rewarding mechanism, adding a new, economic, layer to the social media service. The reward mechanism grants virtual tokens to the users capable of engaging other users on the platform, which can be either vested in the platform for increased influence or exchanged for fiat currency. The introduction of an economic layer on a social networking platform can seriously influence how people socialize. In this work, we tackle the problem of understanding how this new business model conditions the way people create contents. We performed term frequency and topic modelling analyses over the written contents published on the platforms between 2017 and 2019. This analysis lets us understand the most common topics of the contents that appear in the platform. While personal mundane information still appears, along with contents related to arts, food, travels, and sport, we also see emerging a very strong presence of contents about blockchain, cryptocurrency and, more specifically, on Steemit itself and its users

Emergency radiology without the radiologist: the forensic perspective

Purpose. The aim of this paper is to describe two cases from the authors\u27 forensic archive database in which teleradiology was related to unfavourable outcomes. Material and methods. Two patients underwent autopsy after unexpected death following road accidents. In one case, death was caused by multiple cervical fractures following minor neck injury in the presence of diffuse idiopathic skeletal hyperostosis. In the other case, death was due to delayed isthmic aortic rupture occurring after thoracic blunt trauma in a young adult. Both conditions were diagnosed at autopsy only. Results. In both cases, the lethal outcome was due to the failure to obtain radiological reports of the X-rays performed in the emergency department. Radiological diagnoses could have been established by activating the teleradiology service which, according to the hospitals\u27 teleradiology protocols, is available on demand in cases of emergency only, as selected by the physician requesting the service. Conclusions. These cases suggest the high risk of excluding the radiologist from the management of patients whose images are transmitted via a teleradiology system.Obiettivo. Gli autori intendono descrivere due casi tratti dal proprio archivio autoptico medico-legale nei quali l\u27esito sfavorevole ? connesso all\u27uso della teleradiologia. Materiali e metodi. Sono descritte le risultanze dell\u27indagine autoptica eseguita su due soggetti deceduti in maniera inattesa dopo incidente della strada. In un caso la morte ? dipesa da fratture cervicali multiple determinatesi, in soggetto affetto da DISH (iperostosi scheletrica idiopatica diffusa), per un trauma minore del collo. Nel secondo caso un giovane adulto riportava una contusione del torace con "rottura in due tempi" dell\u27istmo aortico. Entrambe le patologie traumatiche sono state diagnosticate solo in sede di esame autoptico. Risultati. La mancata diagnosi in vita ha tratto origine, in entrambi i casi, dalla "non refertazione" degli esami radiologici eseguiti in urgenza; la diagnosi radiologica avrebbe potuto effettuarsi mediante attivazione del sistema di teleradiologia, utilizzabile, secondo il protocollo gestionale della struttura, solo in casi urgenti, selezionati dal medico richiedente la prestazione. Conclusioni. Questi due casi suggeriscono che l\u27esclusione del radiologo dalla gestione dei pazienti le cui immagini sono trasmesse in teleradiologia comporta un rischio molto elevato di prestazioni inadeguate