303 research outputs found

    Polynomially Over-Parameterized Convolutional Neural Networks Contain Structured Strong Winning Lottery Tickets

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    The Strong Lottery Ticket Hypothesis (SLTH) states that randomly-initialised neural networks likely contain subnetworks that perform well without any training. Although unstructured pruning has been extensively studied in this context, its structured counterpart, which can deliver significant computational and memory efficiency gains, has been largely unexplored. One of the main reasons for this gap is the limitations of the underlying mathematical tools used in formal analyses of the SLTH. In this paper, we overcome these limitations: we leverage recent advances in the multidimensional generalisation of the Random Subset-Sum Problem and obtain a variant that admits the stochastic dependencies that arise when addressing structured pruning in the SLTH. We apply this result to prove, for a wide class of random Convolutional Neural Networks, the existence of structured subnetworks that can approximate any sufficiently smaller network. This result provides the first sub-exponential bound around the SLTH for structured pruning, opening up new avenues for further research on the hypothesis and contributing to the understanding of the role of over-parameterization in deep learning.Comment: To be published in the 37th Conference on Neural Information Processing Systems (NeurIPS 2023

    A Chemical Transport Model Emulator for the Interactive Evaluation of Mercury Emission Reduction Scenarios

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    Implementation of the Minamata Convention on Mercury requires all parties to "control, and where feasible, reduce" mercury (Hg) emissions from a convention-specified set of sources. However, the convention does not specify the extent of the measures to be adopted, which may only be analysed by decision-makers using modelled scenarios. Currently, the numerical models available to study the Hg atmospheric cycle require significant expertise and high-end hardware, with results which are generally available on a time frame of days to weeks. In this work we present HERMES, a statistical emulator built on the output of a global Chemical Transport Model (CTM) for Hg (ECHMERIT), to simulate changes in anthropogenic Hg (Hganthr) deposition fluxes in a source-receptor framework, due to perturbations to Hganthr emissions and the associated statistical significance of the changes. The HERMES emulator enables stakeholders to evaluate the implementation of different Hganthr emission scenarios in an interactive and real-time manner, simulating the application of the different Best Available Technologies. HERMES provides the scientific soundness of a full CTM numerical framework in an interactive and user-friendly spreadsheet, without the necessity for specific training or formation and is a first step towards a more comprehensive, and integrated, decision support system to aid decision-makers in the implementation of the Minamata Convention

    The GOS4M Knowledge Hub: A web-based effectiveness evaluation platform in support of the Minamata Convention on Mercury

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    Abstract The Minamata Convention on Mercury was established to reduce the pressure on the environment caused by mercury by significantly reducing its emissions from anthropogenic activities. However, knowledge gaps still exist concerning emission inventories, emission factors and their integration in modelling frameworks. In addition, tools to facilitate communication between decision-makers and research groups providing measurement and modelling data are still scarce. This work presents the GOS4M Knowledge Hub, a public web application that provides an interactive and user friendly experience to access state-of-the-art modelling tools and data available in the literature. The Knowledge Hub currently integrates a Chemical Transport Model emulator, HERMES, coupled with a biogeochemical model, although it has been designed to house and deploy any number of different modelling components. Using the integrated dashboard, non-experts can perturb mercury releases from different anthropogenic emission sectors, simulating, for example, the application of Best Available Technologies, and then visualise in real-time the short- and long-term effects of the consequent reductions within a source-receptor framework. The dashboard also furnishes an estimate of the statistical significance of the changes in the model results. The analysis of a set of anthropogenic Hg emission reduction scenarios shows how an internationally coordinated effort would be necessary to achieve significant policy goals. It is important to note that the GOS4M Knowledge Hub yields the analysis presented here in a matter of seconds, compared to the days or weeks required by traditional modelling tools

    Integration and optimization of the after-treatments systems to reduce the acoustic footprint of the ships

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    Exhaust Gas Cleaning Systems (EGCS) such as scrubbers are mandatory and extensively used to abate SOx in exhaust gases when high sulphur content fuel oil is employed in the marine engine in order to comply with international ship emission regulations, both in new and existing ships. Currently, about 13% of bulker, container, and tanker ships have a scrubber installed, despite the fact that their installation on board is challenging due to their large dimensions to be fitted into the funnel and the complexity of the system, since the exhaust line must control both the chemical and acoustic emissions. In the presented work a combined FEM, CFD simulations and GA optimization methodology aimed at the integration of the abatement system, while optimizing the acoustic properties, is developed. The methodology is first assessed on an industrially-relevant scenario that involves the use of a Genset mock-up equipped with a reference Diesel Oxidation Catalyst (DOC) and a scrubber for the abatement of both NOx and SOx, showing that acoustic performances of the DOC are reliably modelled by the FEM-CFD methodology, which has a significantly reduced computational cost as compared to conventional CFD modelling of acoustic properties. The GA optimization is carried out to improve the DOC acoustic properties showing that it is possible to confer the silencing effect to the after-treatment systems, thus eliminating the traditional silencers from the exhaust line. This leads to a compact exhaust line that integrates the EGCS while maintaining efficient both the chemical pollution abatement capability, and silencing effects to guarantee full compliance (i.e., acoustic and chemical) with the international regulations

    An Assessment of Stratospheric Intrusions in Italian Mountain Regions Using STEFLUX

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    The Mediterranean basin is considered a global hot-spot region for climate change and air quality, especially concerning summer-time ozone (O3). Previous investigations indicated that the Mediterranean basin is a preferred region for stratosphere-to-troposphere exchange (STE) and deep stratospheric intrusion (SI) events. The Lagrangian tool STEFLUX, based on a STE climatology that uses the ERA Interim data, was hereby used to diagnose the occurrence of deep SI events in four mountain regions over the Italian peninsula, spanning from the Alpine region to the southern Apennines. By using near-surface O3 and relative humidity (RH) observations at three high-mountain observatories, we investigated the performance of STEFLUX in detecting deep SI events. Both experimental and STEFLUX detections agreed in describing the seasonal cycle of SI occurrence. Moreover, STEFLUX showed skills in detecting "long-lasting" SI events, especially in the Alps and in the northern Apennines. By using STEFLUX, we found positive tendencies in the SI occurrence during 1979–2017. However, in contrast to similar studies carried out in the Alpine region, the negative long-term (1996–2016) trend of O3 in the northern Apennines did not appear to be related to the SI's variability

    Low Absolute Lymphocyte Counts in the Peripheral Blood Predict Inferior Survival and Improve the International Prognostic Index in Testicular Diffuse Large B-Cell Lymphoma

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    Low absolute lymphocyte counts (ALC) and high absolute monocyte counts (AMC) are associated with poor survival in patients with diffuse large B-cell lymphoma (DLBCL). We studied the prognostic impact of the ALC and AMC in patients with testicular DLBCL (T-DLBCL). T-DLBCL patients were searched using Southern Finland University Hospital databases and the Danish lymphoma registry. The progression free survival (PFS) and overall survival (OS) were assessed using Kaplan-Meier and Cox proportional hazards methods. We identified 178 T-DLBCL patients, of whom 78 (44%) had a low ALC at diagnosis. The ALC did not correlate with survival in the whole cohort. However, among the patients treated with rituximab (R) containing regimen, a pre-therapeutic low ALC was associated with an increased risk of progression (HR 1.976, 95% CI 1.267-3.086,p= 0.003). Conversely, intravenous (iv) CNS directed chemotherapy translated to favorable outcome. In multivariate analyses, the advantage of an iv CNS directed chemotherapy was sustained (PFS, HR 0.364, 95% CI 0.175-0.757,p= 0.007). The benefit of R and intravenous CNS directed chemotherapy was observed only in non-lymphopenic patients. The AMC did not correlate with survival. A low ALC is an adverse prognostic factor in patients with T-DLBCL. Alternative treatment options for lymphopenic patients are needed.Peer reviewe

    Identification of homozygous deletion in ACAN and other candidate variants in familial classical Hodgkin lymphoma by exome sequencing

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    Tutkimuksessamme tarkastelimme Lähi-idästä lähtöisin olevaa perhettä, jossa kolmella viidestä lapsesta on todettu nuorellä iällä klassinen Hodgkinin lymfooma (cHL). Perinnöllinen alttius cHL:lle tunnetaan huonosti, eikä taudille mahdollisesti altistavia geenimuutoksia ole aiemmin raportoitui kuin yksi kappale. Geenimuutosten selvittämiseksi eksomisekvensoimme kolmen sairastuneen lapsen verinäytteestä eristetyn DNA:n ja poimimme joukosta kaikkien kolmen jakamat muutokset. Suodatimme lasten jakamien DNA-muutosten joukosta pois omissa vertailujoukoissamme ja useissa julkisissa tietokannoissa esiintyvät geneettiset muutokset ja arvioimme jäljellejääneiden muutosten haitallisuutta kahdella laskennallisella priorisaatioalgoritmilla. Näin saimme järjestettyä jäljelle jääneet 35 jaettua muutosta laskennalliseen haitallisuusjärjestykseen. Jaetuista muutoksista merkittävimmäksi nousi ACAN-geenissä oleva homotsygoottinen 57 emäksen pituinen deleetio c.2836_2892del, jota ei ole aiemmin liitytty cHL-fenotyyppiin

    Effect of load spatial configuration on the heating of chicken meat assisted by radio frequency at 40.68 MHz

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    Food heating assisted by radio frequencies has been industrially applied to post-harvest treat-ment of grains, legumes and various kind of nuts, to tempering and thawing of meat and fish products and to post-baking of biscuits. The design of food processes based on the application of radiofrequencies was often based on rules of thumb, so much so that their intensification could lead significant improvements. One of the subjects under consideration is the shape of the food items that may influence their heating assisted by radiofrequency. In this work, a joint experi-mental and numerical study on the effects of the spatial configuration of a food sample (chicken meat shaped as a parallelepiped) on the heating pattern in a custom RF oven (40.68 MHz, 50 Ohm, 10 cm electrodes gap, 300 W) is presented. Minced chicken breast samples were shaped as cubes (4 × 4 × 4 cm3) to be organized in different loads and spatial configurations (horizontal or vertical arrays of 2 to 16 cubes). The samples were heated at two radiofrequency operative pow-er levels (225 W and 300 W). Heating rate, temperature uniformity and heating efficiency were determined during each run. A digital twin of the experimental system and process was devel-oped by building and numerically solving a 3D transient mathematical model, taking into ac-count electromagnetic field distribution in air and samples and heat transfer in the food samples. Once validated, the digital tool was used to analyze the heating behavior of the samples, focus-ing on the most efficient configurations. Both experiments and simulations showed that, given a fixed gap between the electrodes (10 cm), the vertically oriented samples exhibited a larger heat-ing efficiency with respect to the horizontally oriented ones, pointing out that the gap between the top electrode and the samples plays a major role in the heating efficiency. The efficiency was larger (double or even more; >40% vs. 10?15%) in thicker samples (built with two layers of cu-bes), closer to the top electrode, independently from nominal power. Nevertheless, temperature uniformity in vertical configurations was poorer (6?7 °C) than in horizontal ones (3 °C).Fil: Goñi, Sandro Mauricio. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; ArgentinaFil: d'Amore, Mateo. Universita di Salerno; ItaliaFil: Della Valle, Marta. Universita di Salerno; ItaliaFil: Olivera, Daniela Flavia. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; ArgentinaFil: Salvadori, Viviana Olga. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; Argentina. Universidad Nacional de La Plata. Facultad de Ingeniería; ArgentinaFil: Marra, Francesco. Universita Di Salerno. Facolta Di Ingegneria; Itali

    Genome wide transcriptional analysis of resting and IL2 activated human natural killer cells: gene expression signatures indicative of novel molecular signaling pathways

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    <p>Abstract</p> <p>Background</p> <p>Human natural killer (NK) cells are the key contributors of innate immune response and the effector functions of these cells are enhanced by cytokines such as interleukine 2 (IL2). We utilized genome-wide transcriptional profiling to identify gene expression signatures and pathways in resting and IL2 activated NK cell isolated from peripheral blood of healthy donors.</p> <p>Results</p> <p>Gene expression profiling of resting NK cells showed high expression of a number of cytotoxic factors, cytokines, chemokines and inhibitory and activating surface NK receptors. Resting NK cells expressed many genes associated with cellular quiescence and also appeared to have an active TGFβ (TGFB1) signaling pathway. IL2 stimulation induced rapid downregulation of quiescence associated genes and upregulation of genes associated with cell cycle progression and proliferation. Numerous genes that may enhance immune function and responsiveness including activating receptors (<it>DNAM1, KLRC1 </it>and <it>KLRC3</it>), death receptor ligand (<it>TNFSF6 (FASL</it>) and <it>TRAIL</it>), chemokine receptors (<it>CX3CR1, CCR5 </it>and <it>CCR7</it>), interleukin receptors (<it>IL2RG, IL18RAB </it>and <it>IL27RA</it>) and members of secretory pathways (<it>DEGS1, FKBP11, SSR3, SEC61G </it>and <it>SLC3A2</it>) were upregulated. The expression profile suggested PI3K/AKT activation and NF-κB activation through multiple pathways (TLR/IL1R, TNF receptor induced and TCR-like possibly involving BCL10). Activation of NFAT signaling was supported by increased expression of many pathway members and downstream target genes. The transcription factor <it>GATA3 </it>was expressed in resting cells while <it>T-BET </it>was upregulated on activation concurrent with the change in cytokine expression profile. The importance of NK cells in innate immune response was also reflected by late increased expression of inflammatory chemotactic factors and receptors and molecules involved in adhesion and lymphocyte trafficking or migration.</p> <p>Conclusion</p> <p>This analysis allowed us to identify genes implicated in cellular quiescence and the cytokines and cytotoxic factors ready for immediate immune response. It also allowed us to observe the sequential immunostimulatory effects of IL2 on NK cells improving our understanding of the biology and molecular mediators behind NK cell activation.</p
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