A new data analysis framework for the search of continuous gravitational wave signals

Continuous gravitational wave signals, like those expected by asymmetric spinning neutron stars, are among the most promising targets for LIGO and Virgo detectors. The development of fast and robust data analysis methods is crucial to increase the chances of a detection. We have developed a new and flexible general data analysis framework for the search of this kind of signals, which allows to reduce the computational cost of the analysis by about two orders of magnitude with respect to current procedures. This can correspond, at fixed computing cost, to a sensitivity gain of up to 10%-20%, depending on the search parameter space. Some possible applications are discussed, with a particular focus on a directed search for sources in the Galactic center. Validation through the injection of artificial signals in the data of Advanced LIGO first observational science run is also shown.Comment: 21 pages, 8 figure

QGRS Mapper: a web-based server for predicting G-quadruplexes in nucleotide sequences

The quadruplex structures formed by guanine-rich nucleic acid sequences have received significant attention recently because of growing evidence for their role in important biological processes and as therapeutic targets. G-quadruplex DNA has been suggested to regulate DNA replication and may control cellular proliferation. Sequences capable of forming G-quadruplexes in the RNA have been shown to play significant roles in regulation of polyadenylation and splicing events in mammalian transcripts. Whether quadruplex structure directly plays a role in regulating RNA processing requires investigation. Computational approaches to study G-quadruplexes allow detailed analysis of mammalian genomes. There are no known easily accessible user-friendly tools that can compute G-quadruplexes in the nucleotide sequences. We have developed a web-based server, QGRS Mapper, that predicts quadruplex forming G-rich sequences (QGRS) in nucleotide sequences. It is a user-friendly application that provides many options for defining and studying G-quadruplexes. It performs analysis of the user provided genomic sequences, e.g. promoter and telomeric regions, as well as RNA sequences. It is also useful for predicting G-quadruplex structures in oligonucleotides. The program provides options to search and retrieve desired gene/nucleotide sequence entries from NCBI databases for mapping G-quadruplexes in the context of RNA processing sites. This feature is very useful for investigating the functional relevance of G-quadruplex structure, in particular its role in regulating the gene expression by alternative processing. In addition to providing data on composition and locations of QGRS relative to the processing sites in the pre-mRNA sequence, QGRS Mapper features interactive graphic representation of the data. The user can also use the graphics module to visualize QGRS distribution patterns among all the alternative RNA products of a gene simultaneously on a single screen. QGRS Mapper can be accessed at

A semi-coherent analysis method to search for continuous gravitational waves emitted by ultra-light boson clouds around spinning black holes

As a consequence of superradiant instability induced in Kerr black holes, ultra-light boson clouds can be a source of persistent gravitational waves, potentially detectable by current and future gravitational-wave detectors. These signals have been predicted to be nearly monochromatic, with a small steady frequency increase (spin-up), but given the several assumptions and simplifications done at theoretical level, it is wise to consider, from the data analysis point of view, a broader class of gravitational signals in which the phase (or the frequency) slightly wander in time. Also other types of sources, e.g. neutron stars in which a torque balance equilibrium exists between matter accretion and emission of persistent gravitational waves, would fit in this category. In this paper we present a robust and computationally cheap analysis pipeline devoted to the search of such kind of signals. We provide a full characterization of the method, through both a theoretical sensitivity estimation and through the analysis of syntethic data in which simulated signals have been injected. The search setup for both all-sky searches and higher sensitivity directed searches is discussed.Comment: 13 pages, 13 figure

An intrusion and fault tolerant forensic storage for a SIEM system

Current Security Information and Events Management (SIEM) solutions lack a data storage facility which is secure enough - i.e. stored events related to security incidents cannot be forged and are always available - that it can be used for forensic purposes. Forensic storage used by current SIEM solutions uses traditional RSA algorithm to sign the security events. In this paper we have analyzed the limits of current forensic storages, and we have proposed an architecture for forensic storage, implementing a threshold-based variant of the RSA algorithm, that outperforms state of the art SIEM solutions in terms of intrusion- and fault-tolerance. We show by experiments that our forensic storage works correctly even in the presence of cyber-attacks, although with a performance penalty. We also conduct an experimental campaign to evaluate the performance cost of the proposed scheme as a function of the threshold

Facing the blockchain endpoint vulnerability, an SGX-based solution for secure eHealth auditing

According to McAfee Labs, even in 2019, the eHealth sector is confirmed as one of the most critical in terms of cybersecurity incidents. It is estimated that more than 176 million patient records were target of attacks between 2009 and 2017, and with a single attack, in 2018, more than 1.4 million patient records were affected at UnityPoint Health. To cope with such a dramatic situation, one of the main strategic priority in the eHealth field is represented by the adoption of Blockchain. Specifically, according to a Deloittes survey, 55% of healthcare executives believe that blockchain technology will disrupt the healthcare industry. Unfortunately, while blockchain provides a valuable tool for enhancing the security of health applications and related data, it cannot be assumed as a panacea for data security. As an example, the so-called Endpoint Vulnerability issue is a well-known problem of Blockchain-based solutions: in such a case the attacker successful in gaining control of the end-point can tamper data off-chain during its generation and/or before it is sent to the chain. In this paper, we face such an issue by shielding the endpoint through the Intel Software Guard eXtension (SGX) technology. We demonstrate our solution for an auditing software belonging to the European eHealth management system (namely OpenNCP). We also discuss how our solution can be generalized to any other Blockchain-based solution. Finally, an experimental evaluation has been conducted to prove the actual feasibility of the proposed solution under the requirements of the real eHealth system

Boom‐bust dynamics in biological invasions: towards an improved application of the concept

Boom‐bust dynamics – the rise of a population to outbreak levels, followed by a dramatic decline – have been associated with biological invasions and offered as a reason not to manage troublesome invaders. However, boom‐bust dynamics rarely have been critically defined, analyzed, or interpreted. Here, we define boom‐bust dynamics and provide specific suggestions for improving the application of the boom‐bust concept. Boom‐bust dynamics can arise from many causes, some closely associated with invasions, but others occurring across a wide range of ecological settings, especially when environmental conditions are changing rapidly. As a result, it is difficult to infer cause or predict future trajectories merely by observing the dynamic. We use tests with simulated data to show that a common metric for detecting and describing boom‐bust dynamics, decline from an observed peak to a subsequent trough, tends to severely overestimate the frequency and severity of busts, and should be used cautiously if at all. We review and test other metrics that are better suited to describe boom‐bust dynamics. Understanding the frequency and importance of boom‐bust dynamics requires empirical studies of large, representative, long‐term data sets that use clear definitions of boom‐bust, appropriate analytical methods, and careful interpretations

Dark Matter searches using gravitational wave bar detectors: quark nuggets and newtorites

Many experiments have searched for supersymmetric WIMP dark matter, with null results. This may suggest to look for more exotic possibilities, for example compact ultra-dense quark nuggets, widely discussed in literature with several different names. Nuclearites are an example of candidate compact objects with atomic size cross section. After a short discussion on nuclearites, the result of a nuclearite search with the gravitational wave bar detectors Nautilus and Explorer is reported. The geometrical acceptance of the bar detectors is 19.5 $\rm m^2$ sr, that is smaller than that of other detectors used for similar searches. However, the detection mechanism is completely different and is more straightforward than in other detectors. The experimental limits we obtain are of interest because, for nuclearites of mass less than $10^{-5}$ g, we find a flux smaller than that one predicted considering nuclearites as dark matter candidates. Particles with gravitational only interactions (newtorites) are another example. In this case the sensitivity is quite poor and a short discussion is reported on possible improvements.Comment: published on Astroparticle Physics Sept 25th 2016 replaced fig 1