420 research outputs found

    An ensemble neural network approach for space-time landslide predictive modelling

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    There is an urgent need for accurate and effective Landslide Early Warning Systems (LEWS). Most LEWS are currently based on a single temporally-aggregated measure of rainfall derived from either in-situ measurements or satellite-based rainfall estimates. Relying on a summary metric of precipitation may not capture the complexity of the rainfall signal and its dynamics in space and time in triggering landslides. Here, we present a proof-of-concept for constructing a LEWS that is based on an integrated spatio-temporal modelling framework. Our proposed methodology builds upon a recent approach that uses a daily rainfall time series instead of the traditional cumulated scalar approximation. Specifically, we partition the study area into slope units and use a Gated Recurrent Unit (GRU) to process a satellite-derived rainfall time series and combine the output features with a second neural network (NN) tasked with capturing the effect of terrain characteristics. To assess if our approach enhances accuracy, we applied it in Vietnam and compared it against a standard modelling approach that incorporates terrain characteristics and cumulative rainfall over 14 days. Our protocol leads to better performance in hindcasting landslides when using past rainfall estimates (CHIRPS), as compared to the standard modelling approach. While not tested here, our approach can be extended to rainfall obtained from weather forecasts, potentially leading to actual landslide forecasts

    CleanET: enabling timing validation for complex automotive systems

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    Timing validation for automotive systems occurs in late integration stages when it is hard to control how the instances of software tasks overlap in time. To make things worse, in complex software systems, like those for autonomous driving, tasks schedule has a strong event-driven nature, which further complicates relating those task-overlapping scenarios (TOS) captured during the software timing budgeting and those observed during validation phases. This paper proposes CleanET, an approach to derive the dilation factor r caused due to the simultaneous execution of multiple tasks. To that end, CleanET builds on the captured TOS during testing and predicts how tasks execution time react under untested TOS (e.g. full overlap), hence acting as a mean of robust testing. CleanET also provides additional evidence for certification about the derived timing budgets for every task. We apply CleanET to a commercial autonomous driving framework, Apollo, where task measurements can only be reasonably collected under 'arbitrary' TOS. Our results show that CleanET successfully derives the dilation factor and allows assessing whether execution times for the different tasks adhere to their respective deadlines for unobserved scenarios.This work has been partially supported by the Spanish Ministry of Economy and Competitiveness (MINECO) under grant TIN2015- 65316-P, the SuPerCom European Research Council (ERC) project under the European Union’s Horizon 2020 research and innovation programme (grant agreement No. 772773), and the HiPEAC Network of Excellence. MINECO partially supported Jaume Abella under Ramon y Cajal postdoctoral fellowship (RYC-2013-14717).Peer ReviewedPostprint (author's final draft

    Hidden cycle of dissolved organic carbon in the deep ocean

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    Marine dissolved organic carbon (DOC) is a large (660 Pg C) reactive carbon reservoir that mediates the oceanic microbial food web and interacts with climate on both short and long timescales. Carbon isotopic content provides information on the DOC source via δ[superscript 13]C and age via Δ[superscript 14]C. Bulk isotope measurements suggest a microbially sourced DOC reservoir with two distinct components of differing radiocarbon age. However, such measurements cannot determine internal dynamics and fluxes. Here we analyze serial oxidation experiments to quantify the isotopic diversity of DOC at an oligotrophic site in the central Pacific Ocean. Our results show diversity in both stable and radio isotopes at all depths, confirming DOC cycling hidden within bulk analyses. We confirm the presence of isotopically enriched, modern DOC cocycling with an isotopically depleted older fraction in the upper ocean. However, our results show that up to 30% of the deep DOC reservoir is modern and supported by a 1 Pg/y carbon flux, which is 10 times higher than inferred from bulk isotope measurements. Isotopically depleted material turns over at an apparent time scale of 30,000 y, which is far slower than indicated by bulk isotope measurements. These results are consistent with global DOC measurements and explain both the fluctuations in deep DOC concentration and the anomalous radiocarbon values of DOC in the Southern Ocean. Collectively these results provide an unprecedented view of the ways in which DOC moves through the marine carbon cycle.National Science Foundation (U.S.) (Grant OCE-0930866)National Science Foundation (U.S.) (Grant OCE-0930551

    A heuristic to minimize the cardinality of a real-time task set by automated task clustering

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    International audienceWe propose in this paper a method to automatically map functionalities (blocks of code corresponding to high-level features) with real-time constraints to tasks (or threads). We aim at reducing the number of tasks functions are mapped to, while preserving the schedulability of the initial system. We consider independent tasks running on a single processor. Our approach has been applied with fixed-task or fixed-job priorities assigned in a Deadline Monotonic (DM) or a Earliest Deadline First (EDF) manner

    Preliminary attempt to predict risk of invasive pulmonary aspergillosis in patients with influenza. Decision trees may help?

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    Invasive pulmonary aspergillosis (IPA) is typically considered a disease of immunocompromised patients, but, recently, many cases have been reported in patients without typical risk factors. The aim of our study is to develop a risk predictive model for IPA through machine learning techniques (decision trees) in patients with influenza. We conducted a retrospective observational study analyzing data regarding patients diagnosed with influenza hospitalized at the University Hospital “Umberto I” of Rome during the 2018-2019 season. We collected five IPA cases out of 77 influenza patients. Although the small sample size is a limit, the most vulnerable patients among the influenza-infected population seem to be those with evidence of lymphocytopenia and those that received corticosteroid therapy

    Antiviral activity of fecal water samples from HIV-1 infected subjects treated with a specific probiotic formulation

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    Objectives: The aim of the study was to investigate if the supplementation with multistrain probiotics may be able to modulate T cell response in HIV-1 infected patients and to evaluate the anti-HIV activity of probiotic by studying fecal water (FW) samples. Methods: Three HIV-1-positive patients (Pt1, Pt2 and Pt3) on long-term suppressive combined antiretroviral therapy (cART) received a specific multi-strain probiotic supplementation (Vivomixx ®), for six months (T6). Levels of T cell subsets were evaluated by flow cytometry. Anti- HIV activity of FW samples was evaluated in vitro. Results: CD4+ T cells levels increased in all HIV-1 infected patients whereas activation markers (CD38 and HLA-DR) were decreased both on CD4+ and CD8+ T cells. FW samples presented an increased inhibitory activity against HIV-1 compared to T0 (FW-Pt1: T0 =40%, T6 = 65% of reduction; FW Pt2: T0 = 26%, T6 = 46% of reduction; FW Pt3: T0 = 47%, T6 = 94% of reduction). Discussion: Our data suggest that the administration of the specific probiotic formulation improves the antiviral status of people living with HIV-1 under cART, also modulating T cell response. Conclusion: Anti-HIV activity of FW may have several public health and social implications for sexually transmitted diseases that need to be further explored

    Oral bacteriotherapy in patients with COVID-19: a retrospective cohort study

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    Background: Mounting evidence suggests SARS-CoV-2 may impact on host microbiota and gut inflammation, infecting intestinal epithelial cells. This possible link and its implications can be investigated by observing the effects of modulation of the microbial flora in patients with COVID-19. The aim of this study was to compare the rate of mortality, the need of ICU hospitalization and the length of hospitalization in patients with severe COVID-19 pneumonia who received the best available therapy (BAT) vs. patients treated with BAT and supplemented with oral bacteriotherapy. Methods: This retrospective, observational cohort study included 200 adults with severe COVID-19 pneumonia. All patients received therapeutic regimens including low molecular weight heparin plus one or more between hydroxychloroquine, azithromycin, antivirals, and Tocilizumab. Oral bacteriotherapy was used as complementary treatment. Results: Out of the 200 patients, 112 received BAT without oral bacteriotherapy, and 88 BAT with oral bacteriotherapy. Crude mortality was 22%. Eleven percent died in the group of patients treated with BAT plus oral bacteriotherapy vs. 30% subjects in the group of patients managed only with BAT (p < 0.001). By multivariate analysis, the age >65 years, CRP >41.8 mg/L, Platelets <150.000 mmc, and cardiovascular events were associated with the increased risk of mortality. Oral bacteriotherapy was an independent variable associated with a reduced risk for death. Despite large prospective trials are needed, this study highlights a possible role for oral bacteriotherapy in the management of patients hospitalized for COVID-19 pneumonia

    Analysis of type I IFN response and T cell activation in severe COVID-19/HIV-1 coinfection. A case report

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    RATIONALE: Complex immune dysregulation in interferon (IFN) and T cell response has been observed in human immunodeficiency virus (HIV-1)-infected patients as well as in coronavirus disease-2019 (COVID-19) patients. However, severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2)/HIV-1 coinfection has been described in only few cases worldwide and no data are available on immunological outcomes in HIV-1-patients infected with SARS-CoV-2. Hence, this study aims to compare type I IFN response and T cell activation levels between a SARS-CoV-2/HIV-1-coinfected female patient and age-matched HIV-1-positive or uninfected women. PATIENT CONCERNS: A 52-year-old woman diagnosed with SARS-CoV-2/HIV-1 coinfection, ten HIV-1-positive women and five age-matched-healthy individuals were enrolled in this study. DIAGNOSES: SARS-CoV-2 infection caused severe pneumonia in the second week of illness in HIV-1-positive patient under protease inhibitors. Chest high-resolution computed tomography images of the SARS-CoV-2/HIV-1-coinfected patient showed bilateral ground-glass opacities. INTERVENTIONS: SARS-CoV-2/HIV-1-coinfected female patient under darunavir/cobicistat regimen received a 7-days hydroxychloroquine therapy. Analysis of IFNα/β mRNA levels and CD4 and CD8 T cell (CD38, human leukocyte antigen-DR [HLA-DR], CD38 HLA-DR) frequencies were performed by RT/real-time PCR assays and flow cytometry, respectively. Median relative difference (MRD) was calculated for each immunological variable. For values greater than reference, MRD should be a positive number and for values that are smaller, MRD should be negative. OUTCOMES: The severe pneumonia observed in SARS-CoV-2/HIV-1-positive patient under protease inhibitors was reversed by a 7-days hydroxychloroquine therapy. At the end of treatment, on day 7, patient reported resolution of fever, normalization of respiratory rate (14 breaths/min), and improved oxygen arterial pressure with a FiO2 of 30%. MRD values for IFNα/β and CD4 and CD8 T cells expressing CD38 and/or HLA-DR found in SARS-CoV-2-/HIV-1-coinfected woman were approximatively equal to 0 when refereed respectively to HIV-1-positive female patients [MRDs IFNα/β: median -0.2545 (range: -0.5/0.1); T cells: median -0.11 (range: -0.8/1.3)] and ≥ 6 when referred to healthy individuals [MRDs IFNα/β: median 28.45 (range: 15/41.9); T cells: median 10 (range 6/22)]. LESSONS: These results indicate that SARS-CoV-2 infection in HIV-1-positive female patient was associated with increased levels of IFNα/β-mRNAs and T cell activation compared to healthy individuals

    Deep-Ocean dissolved organic matter reactivity along the Mediterranea Sea: does size matter?

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    Original research paperDespite of the major role ascribed to marine dissolved organic matter (DOM) in the global carbon cycle, the reactivity of this pool in the dark ocean is still poorly understood. Present hypotheses, posed within the size-reactivity continuum (SRC) and the microbial carbon pump (MCP) conceptual frameworks, need further empirical support. Here, we provide field evidence of the soundness of the SRC model. We sampled the high salinity core-of-flow of the Levantine Intermediate Water along its westward route through the entire Mediterranean Sea. At selected sites, DOM was size-fractionated in apparent high (aHMW) and low (aLMW) molecular weight fractions using an efficient ultrafiltration cell. A percentage decline of the aHMW DOM from 68–76% to 40–55% was observed from the Levantine Sea to the Strait of Gibraltar in parallel with increasing apparent oxygen utilization (AOU). DOM mineralization accounted for 30±3% of the AOU, being the aHMW fraction solely responsible for this consumption, verifying the SRC model in the field. We also demonstrate that, in parallel to this aHMW DOM consumption, fluorescent humic-like substances accumulate in both fractions and protein-like substances decline in the aLMW fraction, thus indicating that not only size matters and providing field support to the MCP modelHOTMIX (grant number CTM2011–30010-C02 01-MAR and 02-MAR) and the project FERMIO (MINECO, CTM2014-57334-JIN), both co-financed with FEDER funds; (reference BES-2012- 056175) from the Spanish Ministry of Economy, Industry and Competitivenes; the project MODMED from CSIC (PIE, 201730E020) and CSIC Program “Junta para la Ampliación de Estudios” co-financed by the ESF (reference JAE DOC 040)Versión del editor2,92

    Ozone as adjuvant support in the treatment of covid-19: a preliminary report of probiozovid trial

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    This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record. Please cite this article as doi: 10.1002/jmv.26636.Rationale: The evaluation of new therapeutic resources against COVID-19 represents a priority in clinical research considering the minimal options currently available. Objectives: To evaluate the adjuvant use of systemic oxygen-ozone administration in the early control of disease progression in patients with COVID-19 pneumonia. Methods: PROBIOZOVID is an ongoing, interventional, randomized, prospective, double-arm trial enrolling patient with COVID-19 pneumonia. From a total of 85 patients screened, 28 were recruited. Patients were randomly divided into ozone- autohemotherapy group (14) and control group (14). The procedure consisted in a daily double-treatment with systemic Oxygen-Ozone administration for 7 days. All patients were treated with ad interim best available therapy. Measurements and Main Results: The primary outcome was delta in the number of patients requiring orotracheal-intubation despite treatment. Secondary outcome was the difference of mortality between the two groups. Moreover, haematological parameters were compared before and after treatment. No differences in the characteristics between groups were observed at baseline. As a preliminary report we have observed that one patient for each group needed intubation and was transferred to ITU. No deaths were observed at 7-14 days of follow up. Thirty-day mortality was 8,3% for ozone group and 10% for controls. Ozone therapy didn’t significantly influence inflammation markers, haematology profile and lymphocyte subpopulations of patients treated. Ozone therapy had an impact on the need for the ventilatory support, although didn’t reach statistical significance. Finally, no adverse events related to the use of ozone-autohemotherapy were reported. Conclusions: Preliminary results, although not showing statistically significant benefits of ozone on COVID-19, did not report any toxicity
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