63 research outputs found

    Recovering Missing Node Features with Local Structure-based Embeddings

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    Node features bolster graph-based learning when exploited jointly with network structure. However, a lack of nodal attributes is prevalent in graph data. We present a framework to recover completely missing node features for a set of graphs, where we only know the signals of a subset of graphs. Our approach incorporates prior information from both graph topology and existing nodal values. We demonstrate an example implementation of our framework where we assume that node features depend on local graph structure. Missing nodal values are estimated by aggregating known features from the most similar nodes. Similarity is measured through a node embedding space that preserves local topological features, which we train using a Graph AutoEncoder. We empirically show not only the accuracy of our feature estimation approach but also its value for downstream graph classification. Our success embarks on and implies the need to emphasize the relationship between node features and graph structure in graph-based learning.Comment: Submitted to 2024 IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP 2024

    Drosophila Interspecific Hybridization Causes a Deregulation of the piRNA Pathway Genes

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    Almost all eukaryotes have transposable elements (TEs) against which they have developed defense mechanisms. In the Drosophila germline, the main transposable element (TE) regulation pathway is mediated by specific Piwi-interacting small RNAs (piRNAs). Nonetheless, for unknown reasons, TEs sometimes escape cellular control during interspecific hybridization processes. Because the piRNA pathway genes are involved in piRNA biogenesis and TE control, we sequenced and characterized nine key genes from this pathway in Drosophila buzzatii and Drosophila koepferae species and studied their expression pattern in ovaries of both species and their F1 hybrids. We found that gene structure is, in general, maintained between both species and that two genes- armitage and aubergine- are under positive selection. Three genes- krimper, methyltransferase 2, and zucchini -displayed higher expression values in hybrids than both parental species, while others had RNA levels similar to the parental species with the highest expression. This suggests that the overexpression of some piRNA pathway genes can be a primary response to hybrid stress. Therefore, these results reinforce the hypothesis that TE deregulation may be due to the protein incompatibility caused by the rapid evolution of these genes, leading to a TE silencing failure, rather than to an underexpression of piRNA pathway genes

    Setup and validation of shake-flask procedures for the determinationof partition coefficients (log D) from low drug amounts

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    Several procedures based on the shake-flask method and designed to require a minimum amount of drug for octanol-water partition coefficient determination have been established and developed. The procedures have been validated by a 28 substance set with a lipophilicity range from -2.0 to 4.5 (logD7.4). The experimental partition is carried out using aqueous phases buffered with phosphate (pH 7.4) and n-octanol saturated with buffered water and the analysis is performed by liquid chromatography. In order to have accurate results, four procedures and eight different ratios between phase volumes are proposed. Each procedure has been designed and optimized (for partition ratios) for a specific range of drug lipophilicity (low, regular and high lipophilicity) and solubility (high and low aqueous solubility). The procedures have been developed to minimize the measurement in the octanolic phase. Experimental logD7.4 values obtained from different procedures and partition ratios show a standard deviation lower than 0.3 and there is a nice agreement when these values are compared with the reference literature one

    The impact of the COVID-19 pandemic on the mental health of healthcare workers:study protocol for the COVID-19 HEalth caRe wOrkErS (HEROES) study

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    BACKGROUND: Preliminary country-specific reports suggest that the COVID-19 pandemic has a negative impact on the mental health of the healthcare workforce. In this paper, we summarize the protocol of the COVID-19 HEalth caRe wOrkErS (HEROES) study, an ongoing, global initiative, aimed to describe and track longitudinal trajectories of mental health symptoms and disorders among health care workers at different phases of the pandemic across a wide range of countries in Latin America, Europe, Africa, Middle-East, and Asia. METHODS: Participants from various settings, including primary care clinics, hospitals, nursing homes, and mental health facilities, are being enrolled. In 26 countries, we are using a similar study design with harmonized measures to capture data on COVID-19 related exposures and variables of interest during two years of follow-up. Exposures include potential stressors related to working in healthcare during the COVID-19 pandemic, as well as sociodemographic and clinical factors. Primary outcomes of interest include mental health variables such as psychological distress, depressive symptoms, and posttraumatic stress disorders. Other domains of interest include potentially mediating or moderating influences such as workplace conditions, trust in the government, and the country’s income level. RESULTS: As of August 2021, ~ 34,000 health workers have been recruited. A general characterization of the recruited samples by sociodemographic and workplace variables is presented. Most participating countries have identified several health facilities where they can identify denominators and attain acceptable response rates. Of the 26 countries, 22 are collecting data and 2 plan to start shortly. CONCLUSIONS: This is one of the most extensive global studies on the mental health of healthcare workers during the COVID-19 pandemic, including a variety of countries with diverse economic realities and different levels of severity of pandemic and management. Moreover, unlike most previous studies, we included workers (clinical and non-clinical staff) in a wide range of settings. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00127-021-02211-9

    Zika virus infection in pregnancy: a protocol for the joint analysis of the prospective cohort studies of the ZIKAlliance, ZikaPLAN and ZIKAction consortia

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    INTRODUCTION: Zika virus (ZIKV) infection in pregnancy has been associated with microcephaly and severe neurological damage to the fetus. Our aim is to document the risks of adverse pregnancy and birth outcomes and the prevalence of laboratory markers of congenital infection in deliveries to women experiencing ZIKV infection during pregnancy, using data from European Commission-funded prospective cohort studies in 20 centres in 11 countries across Latin America and the Caribbean. METHODS AND ANALYSIS: We will carry out a centre-by-centre analysis of the risks of adverse pregnancy and birth outcomes, comparing women with confirmed and suspected ZIKV infection in pregnancy to those with no evidence of infection in pregnancy. We will document the proportion of deliveries in which laboratory markers of congenital infection were present. Finally, we will investigate the associations of trimester of maternal infection in pregnancy, presence or absence of maternal symptoms of acute ZIKV infection and previous flavivirus infections with adverse outcomes and with markers of congenital infection. Centre-specific estimates will be pooled using a two-stage approach. ETHICS AND DISSEMINATION: Ethical approval was obtained at each centre. Findings will be presented at international conferences and published in peer-reviewed open access journals and discussed with local public health officials and representatives of the national Ministries of Health, Pan American Health Organization and WHO involved with ZIKV prevention and control activities

    Omecamtiv mecarbil in chronic heart failure with reduced ejection fraction, GALACTIC‐HF: baseline characteristics and comparison with contemporary clinical trials

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    Aims: The safety and efficacy of the novel selective cardiac myosin activator, omecamtiv mecarbil, in patients with heart failure with reduced ejection fraction (HFrEF) is tested in the Global Approach to Lowering Adverse Cardiac outcomes Through Improving Contractility in Heart Failure (GALACTIC‐HF) trial. Here we describe the baseline characteristics of participants in GALACTIC‐HF and how these compare with other contemporary trials. Methods and Results: Adults with established HFrEF, New York Heart Association functional class (NYHA) ≄ II, EF ≀35%, elevated natriuretic peptides and either current hospitalization for HF or history of hospitalization/ emergency department visit for HF within a year were randomized to either placebo or omecamtiv mecarbil (pharmacokinetic‐guided dosing: 25, 37.5 or 50 mg bid). 8256 patients [male (79%), non‐white (22%), mean age 65 years] were enrolled with a mean EF 27%, ischemic etiology in 54%, NYHA II 53% and III/IV 47%, and median NT‐proBNP 1971 pg/mL. HF therapies at baseline were among the most effectively employed in contemporary HF trials. GALACTIC‐HF randomized patients representative of recent HF registries and trials with substantial numbers of patients also having characteristics understudied in previous trials including more from North America (n = 1386), enrolled as inpatients (n = 2084), systolic blood pressure < 100 mmHg (n = 1127), estimated glomerular filtration rate < 30 mL/min/1.73 m2 (n = 528), and treated with sacubitril‐valsartan at baseline (n = 1594). Conclusions: GALACTIC‐HF enrolled a well‐treated, high‐risk population from both inpatient and outpatient settings, which will provide a definitive evaluation of the efficacy and safety of this novel therapy, as well as informing its potential future implementation

    Statistical UDWDM-PONs Operating With ONU Lasers Under Limited Tunability

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    CoMFA of benzyl derivatives of 2,1,3-benzo and benzothieno[3,2-a]thiadiazine 2,2-dioxides: Clues for the design of phosphodiesterase 7 inhibitors

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    A CoMFA study of benzo- and benzothienothiadiazines derivatives as phosphodiesterase 7 inhibitors has been carried out in order to determine the factors required for the activity of these compounds and also for the selectivity versus other phosphodiesterase isoenzymes. This methodology is employed to gain clues on the design of new fused thiadiazines with improved activity and selectivity on phosphodiesterase 7. Using the information achieved from the three CoMFA models, new structures have been designed in silico and their inhibitory activity on phosphodiesterase 7 was predicted. © 2001 Éditions scientifiques et mĂ©dicales Elsevier SAS.Peer Reviewe

    Detection of Solar Flares from the Analysis of Signal-to-Noise Ratio Recorded by Digisonde at Mid-Latitudes

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    This work proposes a new indirect method to detect the impact of solar flares on ionospheric sounding measurements, i.e., on the signal-to-noise ratio of ionospheric reflected radio signals. The method allows us to detect and characterize the ionospheric absorption of high-frequency radio waves as a product of these energetic events. The detection is based on the estimation of the quiet conditions signal-to-noise ratio (SNR) pattern of the month and the subsequent comparison of this pattern with the SNR for the analyzed day. The method has been tested by using data from Ebro Observatory ionospheric station (DPS4D, EB040), but it can be applied to any other ionospheric station. At EB040, it can provide observational data to the international Service of Rapid Magnetic Variations (SRMV) to help confirm Sfe (Solar Flare Effects). To set up the method, we considered a data set of 262 solar flares that occurred during 2011–2014 and were observed during daylight hours at EB040 (17 X-class, 124 M-class, and 121 C-class). This led to impose a threshold of −20 dB in the SNR for at least four consecutive frequencies to confirm that a solar flare took place. The method is particularly sensitive for the detection of X-class solar flares, performs quite well with M-class events, and is even able to detect some C-class flares with high solar altitude angles. Furthermore, we studied some constraints that affect the detection of solar flares from the analysis of GOES-15 hard X-ray flux data about the considered events. For each flare, we computed its solar altitude angle at the time of the ionospheric sounding to get an estimation of its geoeffective irradiance, which had an effect on the local ionosphere. We can confirm that the method of detection is more effective with flares that present a solar elevation angle higher than 18.94°, a geoeffective hard X-ray irradiance above 3.30 × 10−6 W/m2, and a geoeffective hard X-ray radiant exposure higher than 1.61 × 10−3 J/m2, computed during the 5 min preceding the ionospheric sounding

    REDI: Towards knowledge graph-powered scholarly information management and research networking

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    Academic data management has become an increasingly challenging task as research evolves over time. Essential tasks such as information retrieval and research networking have turned into extremely difficult operations due to an ever-growing number of researchers and scientific articles. Numerous initiatives have emerged in the IT environments to address this issue, especially focused on web technologies. Although those approaches have individually provided solutions for diverse problems, they still can not offer integrated knowledge bases nor flexibility to exploit adequately this information. In this article, we present REDI, a Linked Data-powered framework for academic knowledge management and research networking, which introduces a new perspective of integration. REDI combines information from multiple sources into a consolidated knowledge base through state-of-the-art procedures and leverages semantic web standards to represent the information. Moreover, REDI takes advantage of such knowledge for data visualisation and analysis, which ultimately improves and simplifies many activities including research networking
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