3,278 research outputs found

    Score-driven generalized fitness model for sparse and weighted temporal networks

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    Temporal network data have recently received increasing attention due to the rich information content and valuable insight that appropriate modeling of links’ dynamics can unveil. While most of the literature on temporal network models focuses on binary graphs, each link of a real networks is often associated with a weight, a positive number describing the intensity of the relation between the nodes. Here we propose a novel dynamical model for sparse and weighted temporal networks as a combination of an extension of the fitness model and of the score-driven framework. We consider a zero-augmented generalized linear model to handle the weights and an observation-driven approach to describe time-varying parameters. We propose a flexible approach where the existence probability of a link is independent of its expected weight. This fact represents a crucial difference with alternative specifications proposed in the recent literature, with relevant implications both for the model's flexibility and for the forecasting capability. Our approach also accommodates the network dynamics’ dependence on external variables. We present a link forecasting analysis to data describing the overnight exposures in the Euro interbank market and investigate whether the influence of EONIA rates on the interbank network dynamics has changed over time during the sovereign debt crisis. (c) 2022 Elsevier Inc. All rights reserved

    Environmental Genomics: A Tale of Two Fishes

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    The influence of the environment on two congeneric fishes, Gillichthys mirabilis and Gillichthys seta, that live in the Gulf of California at temperatures of 10-25 degrees C, and up to 42-44 degrees C, respectively, was addressed by analyzing their genomes. Compared with G. mirabilis, G. seta showed some striking features. Substitution rates in the mitochondrial genes were found to be extremely fast, in fact faster than in noncoding control regions (D-loops), from which a divergence time of less than 0.66-0.75 Mya could be estimated. In the nuclear genome, 1) both AT --> GC/GC --> AT and transversion: transition ratios in coding sequences (CDSs) were relatively high; moreover, the ratios of nonsynonymous/synonymous changes (Ka/Ks) suggested that some genes were under positive selection; 2) DNA methylation showed a very significant decrease; and 3) a GC-rich minisatellite underwent a 4-fold amplification in the gene-rich regions. All these observations clearly indicate that the environment (temperature and the accompanying hypoxia) can rapidly mold the nuclear as well as the mitochondrial genome. The stabilization of gene-rich regions by the amplification of the GC-rich minisatellite and by the GC increase in nuclear CDSs is of special interest because it provides a model for the formation of the GC-rich and gene-rich isochores of the genomes of mammals and birds

    Proposal of a health care network based on big data analytics for PDs

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    Health care networks for Parkinson's disease (PD) already exist and have been already proposed in the literature, but most of them are not able to analyse the vast volume of data generated from medical examinations and collected and organised in a pre-defined manner. In this work, the authors propose a novel health care network based on big data analytics for PD. The main goal of the proposed architecture is to support clinicians in the objective assessment of the typical PD motor issues and alterations. The proposed health care network has the ability to retrieve a vast volume of acquired heterogeneous data from a Data warehouse and train an ensemble SVM to classify and rate the motor severity of a PD patient. Once the network is trained, it will be able to analyse the data collected during motor examinations of a PD patient and generate a diagnostic report on the basis of the previously acquired knowledge. Such a diagnostic report represents a tool both to monitor the follow up of the disease for each patient and give robust advice about the severity of the disease to clinicians

    Enriching the GEOFON seismic catalog with automatic energy magnitude estimations

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    We present a seismic catalog (Bindi et al., 2024, https://doi.org/10.5880/GFZ.2.6.2023.010) including energy magnitude Me estimated from P waves recorded at teleseismic distances in the range 20° ≀ Δ ≀ 98° and for depths shorter than 80 km. The catalog is built starting from the event catalog disseminated by GEOFON (GEOFOrschungsNetz), considering 6349 earthquakes with moment magnitude Mw≄5 occurring between 2011 and 2023. Magnitudes are computed using 1 031 396 freely available waveforms archived in EIDA (European Integrated Data Archive) and IRIS (Incorporated Research Institutions for Seismology) repositories, retrieved through the standard International Federation of Digital Seismograph Networks (FDSN) web services (https://www.fdsn.org/webservices/, last access: March 2024). A reduced, high-quality catalog for events with Mw≄5.8 and from which stations and events with only few recordings were removed forms the basis of a detailed analysis of the residuals of individual station measurements, which are decomposed into station- and event-specific terms and a term accounting for remaining variability. The derived Me values are compared to Mw computed by GEOFON and with the Me values calculated by IRIS. Software and tools developed for downloading and processing waveforms for bulk analysis and an add-on for SeisComP for real-time assessment of Me in a monitoring context are also provided alongside the catalog. The SeisComP add-on has been part of the GEOFON routine processing since December 2021 to compute and disseminate Me for major events via the existing services

    Thrombosis in Autoimmune Diseases: A Role for Immunosuppressive Treatments?

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    Autoimmune diseases are not infrequently associated with arterial or venous thrombotic events. Chronic inflammation and immune system impairment are considered the main pathogenetic mechanisms. Some of the drugs used in the treatment of such diseases have been associated with an increased risk of thrombosis. On the contrary, their anti-inflammatory and immune modulator activity could correct some mechanisms leading to thrombosis. In this review, recent evidence available on this topic is examined. There is a lack of adequate studies, but available evidence suggests that glucocorticoids and high-dose immunoglobulins are associated with an increased incidence of venous thromboembolism. Although available data do not allow drawing definite conclusions and more data are needed from future studies and registries, physicians should be aware of these associations

    H9c2 Cardiomyocytes under Hypoxic Stress: Biological Effects Mediated by Sentinel Downstream Targets

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    The association between diabetes and cardiovascular diseases is well known. Related diabetes macro- and microangiopathies frequently induce hypoxia and consequently energy failure to satisfy the jeopardized myocardium basal needs. Additionally, it is widely accepted that diabetes impairs endothelial nitric oxide synthase (eNOS) activity, resulting in diminished nitric oxide (NO) bioavailability and consequent endothelial cell dysfunction. In this study, we analyzed the embryonic heart-derived H9c2 cell response to hypoxic stress after administration of a high glucose concentration to reproduce a condition often observed in diabetes. We observed that 24 h hypoxia exposure of H9c2 cells reduced cell viability compared to cells grown in normoxic conditions. Cytotoxicity and early apoptosis were increased after exposure to high glucose administration. In addition, hypoxia induced a RhoA upregulation and a Bcl-2 downregulation and lowered the ERK activation observed in normoxia at both glucose concentrations. Furthermore, a significant cell proliferation rate increases after the 1400W iNOS inhibitor administration was observed. Again, hypoxia increased the expression level of myogenin, a marker of skeletal muscle cell differentiation. The cardiomyocyte gene expression profiles and morphology changes observed in response to pathological stimuli, as hypoxia, could lead to improper ventricular remodeling responsible for heart failure. Therefore, understanding cell signaling events that regulate cardiac response to hypoxia could be useful for the discovery of novel therapeutic approaches able to prevent heart diseases

    Islamic finance and conventional financial systems. Market trends, supervisory perspectives and implications for central banking activity

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    The paper analyses Islamic finance from the central bank and supervisory authorityÂ’s perspective, focusing on the European and Italian context. It depicts a rapidly expanding sector, with recent annual growth rates of between 10 and 15 percent and a geographical presence that now reaches several Western countries. Future prospects, however, could be hampered by problems concerning the standardization of products, governance structure, supervisory regulation, monetary policy instruments, and liquidity management. Islamic intermediaries are not necessarily riskier than traditional counterparts but their operational structure tends to be more complex. Key issues in supervision include the treatment of investment accounts and transparency. It has been seen that there are limits to the efficiency of the monetary policy instruments developed so far to remedy the prohibition of interest; moreover, the growth of interbank and money markets is hindered by a shortage of "Shari'ah-compliant" products. Problems arising from the participation of Islamic banks in payment systems are also discussed.Islamic finance, Islamic financial institutions, supervision, monetary policy instrments, payment systems

    Conventional echo color Doppler versus ULA-OP in the assessment of venous flow model

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    The quantification of venous flows can be obtained by multiplying cross sectional area, measured on a B-mode video-clip, by velocity values, obtained with Doppler measurements. The Doppler angle between ultrasound (US) line and blood flow requires a manual adjustment. Establishing this parameter is critical in order to calculate blood velocity. However, the operator dependency gives high variable results. It is worth noting that a new class of vector Doppler devices can enhance the accuracy and precision of measurements. Such technology uses a double US line that leads to automatically know the Doppler angle. By comparing in an in vitro model of venous flow conventional echo color Doppler (ECD) equipment with the new device, we found a better minimal difference between the latter and the nominal flow rate (20%). On the contrary, the comparison with conventional ECD showed a difference ranging between 2% and 43%, according to the possible settings of the equipment. Our study demonstrates a better accuracy of the experimental device with respect to conventional ECD in measuring the venous flow rate
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