28 research outputs found

    Diverse applications of the Quantum Walk model in Quantum Information: a theoretical and experimental analysis in the optical framework

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    Quantum Walks have been a very important model in the last thirty years, after their first definition and rigorous description. The analysis of the many possible variations of their behavior has delivered a plethora of solutions and platforms for the many diverse fields of investigation. The applications of the Quantum Walk model spreads from the development of Quantum Algorithm, to the modeling and simulation of systems of the most diverse nature, such as solid state or biological systems. In general, it helped developing a well-established quantum (or coherent) propagation model, which is useful both inside and outside physics. In this thesis, we focus on the study of disordered Quantum Walks, in order to get better understanding of the inuence of Quantum Walk disordered dynamics to non-classical correlations and propagating quantum information. Afterwards, we generalize this dynamical approach to Quantum Information processing, developing a Quantum Receiver for Quantum State Discrimination featuring a time multiplexing structure and we investigate the potentiality of this Quantum Walk inspired framework in the field of Quantum State Discrimination, through the developing and realization of experimental protocols characterized by increasing complexity. We also report on some apparent deviations from this path, although still aimed at the transfer of our expertise, built in previous investigations, to the study of new models and more complex quantum systems

    ALS mutant FUS proteins are recruited into stress granules in induced pluripotent stem cells- derived motoneurons

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    Patient-derived induced Pluripotent Stem Cells (iPSCs) provide an opportunity to study human diseases mainly in those cases where no suitable model systems are available. Here we have taken advantage of in vitro iPSCs derived from patients affected by Amyotrophic Lateral Sclerosis and carrying mutations in the RNA-binding proteins FUS to study the cellular behavior of the mutant proteins in the appropriate genetic background. Moreover, the ability to differentiate iPSCs into spinal cord neural cells provides an in vitro model mimicking the physiological conditions. iPSCs were derived from FUS(R514S) and FUS(R521C) patients' fibroblasts, while in the case of the severe FUS(P525L) mutation, where fibroblasts were not available, a heterozygous and a homozygous iPSC lines were raised by TALEN-directed mutagenesis. We show that aberrant localization and recruitment of FUS into stress granules (SGs) is a prerogative of the FUS mutant proteins and occurs only upon induction of stress in both undifferentiated iPSCs and spinal cord neural cells. Moreover, we show that the incorporation into SGs is proportional to the amount of cytoplasmic FUS, nicely correlating with the cytoplasmic delocalization phenotype of the different mutants. Therefore, the available iPSCs represent a very powerful system for understanding the correlation between FUS mutations, the molecular mechanisms of SG formation and ALS ethiopathogenesis

    Specification and analysis of SOC systems using COWS: a finance case study

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    Service-oriented computing, an emerging paradigm for distributed computing based on the use of services, is calling for the development of tools and techniques to build safe and trustworthy systems, and to analyse their behaviour. Therefore many researchers have proposed to use process calculi, a cornerstone of current foundational research on specification and analysis of concurrent and distributed systems. We illustrate this approach by focussing on COWS, a process calculus expressly designed for specifying and combining services, while modelling their dynamic behaviour. We present the calculus and one of the analysis techniques it enables, that is based on the temporal logic SocL and the associated model checker CMC. We demonstrate applicability of our tools by means of a large case study, from the financial domain, which is first specified in COWS, and then analysed by using SocL to express many significant properties and CMC to verify them

    Service discovery and negotiation with COWS

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    To provide formal foundations to current (web) services technologies, we put forward using COWS, a process calculus for specifying, combining and analysing services, as a uniform formalism for modelling all the relevant phases of the life cycle of service-oriented applications, such as publication, discovery, negotiation, deployment and execution. In this paper, we show that constraints and operations on them can be smoothly incorporated in COWS, and propose a disciplined way to model multisets of constraints and to manipulate them through appropriate interaction protocols. Therefore, we demonstrate that also QoS requirement specifications and SLA achievements, and the phases of dynamic service discovery and negotiation can be comfortably modelled in COWS. We illustrate our approach through a scenario for a service-based web hosting provider

    Transient subdiffusion via disordered quantum walks

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    Transport phenomena play a crucial role in modern physics and applied sciences. Examples include thedissipation of energy across a large system, the distribution of quantum information in optical networks, andthe timely modeling of spreading diseases. In this work we experimentally prove the feasibility of disorderedquantum walks to realize a quantum simulator that is able to model general transient subdiffusive phenomena,exhibiting a sublinear spreading in space over time. Our experiment simulates such phenomena by means ofa finely controlled insertion of various levels of disorder during the evolution of the walker, enabled by theunique flexibility of our setup. This allows us to explore the full range of subdiffusive behaviors, ranging fromanomalous Anderson-like localization to normal diffusion for all experimentally accessible step numbers

    Circ-ZNF609 Is a Circular RNA that Can Be Translated and Functions in Myogenesis

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    Circular RNAs (circRNAs) constitute a family of transcripts with unique structures and still largely unknown functions. Their biogenesis, which proceeds via a back-splicing reaction, is fairly well characterized, whereas their role in the modulation of physiologically relevant processes is still unclear. Here we performed expression profiling of circRNAs during in vitro differentiation of murine and human myoblasts, and we identified conserved species regulated in myogenesis and altered in Duchenne muscular dystrophy. A high-content functional genomic screen allowed the study of their functional role in muscle differentiation. One of them, circ-ZNF609, resulted in specifically controlling myoblast proliferation. Circ-ZNF609 contains an open reading frame spanning from the start codon, in common with the linear transcript, and terminating at an in-frame STOP codon, created upon circularization. Circ-ZNF609 is associated with heavy polysomes, and it is translated into a protein in a splicing-dependent and cap-independent manner, providing an example of a protein-coding circRNA in eukaryotes

    Direct Anterior versus Lateral Approach for Femoral Neck Fracture: Role in COVID-19 Disease

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    Background: During the COVID-19 emergency, the incidence of fragility fractures in elderly patients remained unchanged. The management of these patients requires a multidisciplinary approach. The study aimed to assess the best surgical approach to treat COVID-19 patients with femoral neck fracture undergoing hemiarthroplasty (HA), comparing direct lateral (DL) versus direct anterior approach (DAA). Methods: A single-center, observational retrospective study including 50 patients affected by COVID-19 infection (30 males, 20 females) who underwent HA between April 2020 to April 2021 was performed. The patients were allocated into two groups according to the surgical approach used: lateral approach and anterior approach. For each patient, the data were recorded: age, sex, BMI, comorbidity, oxygen saturation (SpO2), fraction of the inspired oxygen (FiO2), type of ventilation invasive or non-invasive, HHb, P/F ratio (PaO2/FiO2), hemoglobin level the day of surgery and 1 day post operative, surgical time, Nottingham Hip Fractures Score (NHFS) and American Society of Anesthesiologists Score (ASA). The patients were observed from one hour before surgery until 48 h post-surgery of follow-up. The patients were stratified into five groups according to Alhazzani scores. A non-COVID-19 group of patients, as the control, was finally introduced. Results: A lateral position led to a better level of oxygenation (p < 0.01), compared to the supine anterior approach. We observed a better post-operative P/F ratio and a reduced need for invasive ventilation in patients lying in the lateral position. A statistically significant reduction in the surgical time emerged in patients treated with DAA (p < 0.01). Patients within the DAA group had a significantly lower blood loss compared to direct lateral approach. Conclusions: DL approach with lateral decubitus seems to preserved respiratory function in HA surgery. Thus, the lateral position may be associated with beneficial effects on gas exchange

    Using formal methods to develop WS-BPEL applications

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    In recent years, WS-BPEL has become a de facto standard language for orchestration of Web Services. However, there are still some well-known difficulties that make programming in WS-BPEL a tricky task. In this paper, we firstly point out major loose points of the WS-BPEL specification by means of many examples, some of which are also exploited to test and compare the behaviour of three of the most known freely available WS-BPEL engines. We show that, as a matter of fact, these engines implement different semantics, which undermines portability of WS-BPEL programs over different platforms. Then we introduce Blite, a prototypical orchestration language equipped with a formal operational semantics, which is closely inspired by, but simpler than, WS-BPEL. Indeed, Blite is designed around some of WS-BPEL distinctive features like partner links, process termination, message correlation, long-running business transactions and compensation handlers. Finally, we present BliteC, a software tool supporting a rapid and easy development of WS-BPEL applications via translation of service orchestrations written in Blite into executable WS-BPEL programs. We illustrate our approach by means of a running example borrowed from the official specification of WS-BPEL
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