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International audience; We study a quantum switch that distributes tripartite entangled states to sets of users. The entanglement switching process requires two steps: first, each user attempts to generate bipartite entanglement between itself and the switch; and second, the switch performs local operations and a measurement to create multipartite entanglement for a set of three users. In this work, we study a simple variant of this system, wherein the switch has infinite memory and the links that connect the users to the switch are identical. This problem formulation is of interest to several distributed quantum applications, while the technical aspects of this work result in new contributions within queueing theory. The state of the system is modeled as continuous time Markov chain (CTMC) and performance metrics of interest (probability of an empty system, switch capacity, expectation and variance of the number of qubit-pairs stored) are computed via the solution of a two-dimensional functional equation obtained by reducing it to a boundary value problem on a closed curve. This work is a follow up of [28] where a switch distributing entangled multipartite states to sets of users was studied but only the switch capacity and the expected number of stored qubits were derived.

International audience; Porous materials, such as zeolites, have great potential for biomedical applications, thanks to their ability to accommodate positively charged metal-ions and their facile surface functionalization. Although the latter aspect is important to endow the nanoparticles with chemical/colloidal stability and desired biological properties, the possibility for simple ion-exchange enables easy switching between imaging modalities and/or combination with therapy, depending on the envisioned application. In this study, the nanozeolite Linde type L (LTL) with already confirmed magnetic resonance imaging properties, generated by the paramagnetic gadolinium (GdIII) in the inner cavities, was successfully radiolabeled with a positron emission tomography (PET)-tracer zirconium-89 (89Zr). Thereby, exploiting 89Zr-chloride resulted in a slightly higher radiolabeling in the inner cavities compared to the commonly used 89Zr-oxalate, which apparently remained on the surface of LTL. Intravenous injection of PEGylated 89Zr/GdIII-LTL in healthy mice allowed for PET-computed tomography evaluation, revealing initial lung uptake followed by gradual migration of LTL to the liver and spleen. Ex vivo biodistribution confirmed the in vivo stability and integrity of the proposed multimodal probe by demonstrating the original metal/Si ratio being preserved in the organs. These findings reveal beneficial biological behavior of the nanozeolite LTL and hence open the door for follow-up theranostic studies by exploiting the immense variety of metal-based radioisotopes.

International audience; Deformable object manipulation (DOM) is an emerging research problem in robotics. The ability to manipulate deformable objects endows robots with higher autonomy and promises new applications in the industrial, services, and healthcare sectors. However, compared to rigid object manipulation, the manipulation of deformable objects is considerably more complex, and is still an open research problem. Addressing DOM challenges demand breakthroughs in almost all aspects of robotics, namely hardware design, sensing, (deformation) modeling, planning, and control. In this article, we review recent advances and highlight the main challenges when considering deformation in each sub-field. A particular focus of our paper lies in the discussions of these challenges and proposing future directions of research.

Background The Editorial Board of EJNMMI Radiopharmacy and Chemistry releases a biannual highlight commentary to update the readership on trends in the field of radiopharmaceutical development. Main Body This selection of highlights provides commentary on 21 different topics selected by each coauthoring Editorial Board member addressing a variety of aspects ranging from novel radiochemistry to first-in-human application of novel radiopharmaceuticals. Conclusion Trends in radiochemistry and radiopharmacy are highlighted. Hot topics cover the entire scope of EJNMMI Radiopharmacy and Chemistry, demonstrating the progress in the research field, and include new PET-labelling methods for 11C and 18F, the importance of choosing the proper chelator for a given radioactive metal ion, implications of total body PET on use of radiopharmaceuticals, legislation issues and radionuclide therapy including the emerging role of 161Tb.

International audience; This study proposes a framework to analyze accelerated degradation testing (ADT) data in the presence of inspection effects. Motivated by a real dataset from the electric industry, we study two types of effects induced by inspections. After each inspection, the system degradation level instantaneously reduces by a random value. Meanwhile, the degrading rate is elevated afterwards. Considering the absence of observations due to practical reasons, we employ the expectation–maximization (EM) algorithm to analytically estimate the unknown parameters in a stepwise Wiener degradation process with covariates. Moreover, to maintain the level of generality for the adaption of the method in various scenarios, a confidence density approach is utilized to hierarchically estimate the parameters in the acceleration link function. The proposed methods can provide efficient parameter estimation under complex link functions with multiple stress factors. Further, confidence intervals are derived based on the large-sample approximation. Simulation studies and a case study from Schneider Electric are used to illustrate the proposed methods. The results show that the proposed model yields a remarkably better fit to the Schneider data in comparison to the conventional Wiener ADT model.

Computational homogenization allows to let the macroscopic constitutive behavior of materials emerge from microscale simulations without loss of generality with respect to microstructure and microscale constitutive response. Although computationally demanding, computational homogenization works very well for the hardening response of materials where the macroscopic stress and strain fields are smooth. However, in case of softening materials, when localization of deformation takes place, special care is needed to ensure objectivity of the method. In this paper, a generic multiscale computational homogenization approach for modeling onset and propagation of cracks in heterogeneous materials that is capable of considering various microscale mechanisms is presented. The common acoustic tensor bifurcation criterion is reinforced by an additional condition to help detect the localization mode more robustly. After the onset of macroscale localization, a key scale transition parameter is needed to translate the macroscopic displacement jump to an averaged strain over the micromodel domain. Then the macroscale crack is governed by a homogenized traction-separation relation evaluated from the underlying micromodel in which micro-failure accumulates. The scale transition parameter is studied for a range of different scenarios and endowed with a geometrical interpretation. Various numerical tests have been performed to confirm the objectivity and validity of the framework. The framework is generic in the sense that no assumptions on the microscale constitutive or kinematic representation of material failure are made in the scale transition. The framework is also highly compatible with the first order computational homogenization, which minimizes the additional complexity of adding macroscopic crack growth to the computational implementation.

In this work, a detection and classification method for sleep apnea and hypopnea, using photopletysmography (PPG) and peripheral oxygen saturation (SpO 2) signals, is proposed. The detector consists of two parts: one that detects reductions in amplitude fluctuation of PPG (DAP)and one that detects oxygen desaturations. To further differentiate among sleep disordered breathing events (SDBE), the pulse rate variability (PRV) was extracted from the PPG signal, and then used to extract features that enhance the sympatho-vagal arousals during apneas and hypopneas. A classification was performed to discriminate between central and obstructive events, apneas and hypopneas. The algorithms were tested on 96 overnight signals recorded at the UZ Leuven hospital, annotated by clinical experts, and from patients without any kind of co-morbidity. An accuracy of 75.1% for the detection of apneas and hypopneas, in one-minute segments,was reached. The classification of the detected events showed 92.6% accuracy in separating central from obstructive apnea, 83.7% for central apnea and central hypopnea and 82.7% for obstructive apnea and obstructive hypopnea. The low implementation cost showed a potential for the proposed method of being used as screening device, in ambulatory scenarios. ispartof: Ieee Transactions On Biomedical Engineering vol:68 issue:5 ispartof: location:United States status: accepted

The Golo River drains a steep catchment (average gradient of 30 m km−1, surface of 1214 km2) in the northeast part of Corsica Island, delivering sediments to the Ligurian Sea. In this study, we review and revise the geologic map and constrain the extent of the Golo coastal alluvial plain formations and their relative and absolute chronology. To update the surface extent of each formation, we performed a geomorphologic analysis with DEMs and satellite imagery data coupled with an extensive pedogenic and sedimentary field observations database, including a new borehole of 117,4 m depth. Additionally, we performed in-situ cosmogenic 10Be analysis from a depth-profile in the well-preserved alluvial terrace Fy2, yielding a minimum age of 70 ka for its emplacement. Our new chronology, based on cosmogenic 10Be and soil chronosequences, implies older ages than those previously obtained with luminescence methods. Soil mixing by bioturbation is proposed as a possibility to explain differences between luminescence and 10Be ages. In this scenario, 10Be dates the original deposition of the alluvial terrace, while luminescence dates a later soil development. We highlighted at least five outcropping alluvial terraces in the Golo coastal plain, which are controlled by sea-level fluctuations and were most likely deposited during past sea-level highstands (close to present-day sea-level). Moreover, we identified from a borehole more than 117 m of coarse fluvial sediments in the plain, that do not outcrop at the surface. New cosmogenic 26Al/10Be burial ages suggest that this sedimentary unit results from a thick accumulation of fluvial material filling a zone significantly affected by subsidence, probably accommodated by a normal fault during the Early Quaternary.

Intraosseous blood circulation is thought to have a critical role in bone growth and remodeling, fracture healing, and bone disorders. However, it is rarely considered in clinical practice because of the absence of a suitable noninvasive in vivo measurement technique. In this work, we assessed blood perfusion in tibial cortical bone simultaneously with blood flow in the superficial femoral artery with ultrasound imaging in five healthy volunteers. After suppression of stationary signal with singular‐value‐decomposition, pulsatile blood flow in cortical bone tissue is revealed, following the heart rate measured in the femoral artery. Using a method combining transverse oscillations and phase‐based motion estimation, 2D vector flow was obtained in the cortex of the tibia. After spatial averaging over the cortex, the peak blood velocity along the long axis of the tibia was measured at four times larger than the peak blood velocity across the bone cortex. This suggests that blood flow in central (Haversian) canals is larger than in perforating (Volkmann's) canals, as expected from the intracortical vascular organization in humans. The peak blood velocity indicates a flow from the endosteum to the periosteum and from the heart to the foot for all subjects. Because aging and the development of bone disorders are thought to modify the direction and velocity of intracortical blood flow, their quantification is crucial. This work reports for the first time an in vivo quantification of the direction and velocity of blood flow in human cortical bone. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

International audience; In this work, we employ a hierarchical approach for leak diagnosis, where time series analysis of AMR data, demand models and measured flows is first used for demand calibration. In the next step, efficient mathematical optimisation is used to calibrate the pipe roughnesses and valve statuses and update the network data. Finally, the calibrated water network model is employed to first build a dual hydraulic network representation for the combined sensor & water systems, simulation of which provide a first estimate for the leak's size and location. This dual network is then used to (i) detect the start time of the leaks as well as (ii) to compute analytical sensitivities and the Pearson correlation for pressure residuals, which allow further localisation of leaks. This whole process of leak diagnosis and localisation scales well as the dual network size is of the same order as the original network, analytical derivations are used for computing sensitivities, and a fast and stable least squares method is used for calibration and valve status assessment. Demand calibration Data from the 82 AMRs in Area C was used to develop a demand model for the unmeasured customers within the L-town network. Additionally, a virtual inflow measurement of Area C has been constructed from the pump flow measurements and the tank's water level. This virtual inflow was used to (i) validate the demand model and to (ii) estimate the leak outflow in Area C. Various time series models were tested on the AMRs aiming to extract daily and weekly seasonalities and trend components for the different customer types (Residential, Commercial). For both customer types, best performance was achieved with a rather simple model, consisting of a multiplicative superposition of weekly seasonalities (S(t)), a time varying trend (T(t)) and a random component (R(t)) accounting for stochastic variations and measurement noise: where " is the base demand for the corresponding customer type at the measurement node. Subsequently, the time varying demand at each unmeasured location is inferred with this model according to the base demand in the EPANET file. The seasonal and the trend components are shown in Figure 1.

International audience; In this work, we employ a hierarchical approach for leak diagnosis, where time series analysis of AMR data, demand models and measured flows is first used for demand calibration. In the next step, efficient mathematical optimisation is used to calibrate the pipe roughnesses and valve statuses and update the network data. Finally, the calibrated water network model is employed to first build a dual hydraulic network representation for the combined sensor & water systems, simulation of which provide a first estimate for the leak's size and location. This dual network is then used to (i) detect the start time of the leaks as well as (ii) to compute analytical sensitivities and the Pearson correlation for pressure residuals, which allow further localisation of leaks. This whole process of leak diagnosis and localisation scales well as the dual network size is of the same order as the original network, analytical derivations are used for computing sensitivities, and a fast and stable least squares method is used for calibration and valve status assessment. Demand calibration Data from the 82 AMRs in Area C was used to develop a demand model for the unmeasured customers within the L-town network. Additionally, a virtual inflow measurement of Area C has been constructed from the pump flow measurements and the tank's water level. This virtual inflow was used to (i) validate the demand model and to (ii) estimate the leak outflow in Area C. Various time series models were tested on the AMRs aiming to extract daily and weekly seasonalities and trend components for the different customer types (Residential, Commercial). For both customer types, best performance was achieved with a rather simple model, consisting of a multiplicative superposition of weekly seasonalities (S(t)), a time varying trend (T(t)) and a random component (R(t)) accounting for stochastic variations and measurement noise: where " is the base demand for the corresponding customer type at the measurement node. Subsequently, the time varying demand at each unmeasured location is inferred with this model according to the base demand in the EPANET file. The seasonal and the trend components are shown in Figure 1.

Full list of authors: Blanc, Michel; Prieto-Ballesteros, Olga; André, Nicolas; Gomez-Elvira, Javier; Jones, Geraint; Sterken, Veerle; Desprats, William; Gurvits, Leonid I.; Khurana, Krishan; Balmino, Georges; Blöcker, Aljona; Broquet, Renaud; Bunce, Emma; Cavel, Cyril; Choblet, Gaël; Colins, Geoffrey; Coradini, Marcello; Cooper, John; Dirkx, Dominic; Fontaine, Dominique; Garnier, Philippe; Gaudin, David; Hartogh, Paul; Hussmann, Hauke; Genova, Antonio; Iess, Luciano; Jäggi, Adrian; Kempf, Sascha; Krupp, Norbert; Lara, Luisa; Lasue, Jérémie; Lainey, Valéry; Leblanc, François; Lebreton, Jean-Pierre; Longobardo, Andrea; Lorenz, Ralph; Martins, Philippe; Martins, Zita; Marty, Jean-Charles; Masters, Adam; Mimoun, David; Palumba, Ernesto; Parro, Victor; Regnier, Pascal; Saur, Joachim; Schutte, Adriaan; Sittler, Edward C.; Spohn, Tilman; Srama, Ralf; Stephan, Katrin; Szegő, Károly; Tosi, Federico; Vance, Steve; Wagner, Roland; Van Hoolst, Tim; Volwerk, Martin; Wahlund, Jan-Erik; Westall, Frances; Wurz, Peter, Europa is the closest and probably the most promising target to search for extant life in the Solar System, based on complementary evidence that it may fulfil the key criteria for habitability: the Galileo discovery of a sub-surface ocean; the many indications that the ice shell is active and may be partly permeable to transfer of chemical species, biomolecules and elementary forms of life; the identification of candidate thermal and chemical energy sources necessary to drive a metabolic activity near the ocean floor. In this article we are proposing that ESA collaborates with NASA to design and fly jointly an ambitious and exciting planetary mission, which we call the Joint Europa Mission (JEM), to reach two objectives: perform a full characterization of Europa's habitability with the capabilities of a Europa orbiter, and search for bio-signatures in the environment of Europa (surface, subsurface and exosphere) by the combination of an orbiter and a lander. JEM can build on the advanced understanding of this system which the missions preceding JEM will provide: Juno, JUICE and Europa Clipper, and on the Europa lander concept currently designed by NASA (Maize, report to OPAG, 2019). We propose the following overarching goals for our Joint Europa Mission (JEM): Understand Europa as a complex system responding to Jupiter system forcing, characterize the habitability of its potential biosphere, and search for life at its surface and in its sub-surface and exosphere. We address these goals by a combination of five Priority Scientific Objectives, each with focused measurement objectives providing detailed constraints on the science payloads and on the platforms used by the mission. The JEM observation strategy will combine three types of scientific measurement sequences: measurements on a high-latitude, low-altitude Europan orbit; in-situ measurements to be performed at the surface, using a soft lander; and measurements during the final descent to Europa's surface. The implementation of these three observation sequences will rest on the combination of two science platforms: a soft lander to perform all scientific measurements at the surface and sub-surface at a selected landing site, and an orbiter to perform the orbital survey and descent sequences. We describe a science payload for the lander and orbiter that will meet our science objectives. We propose an innovative distribution of roles for NASA and ESA; while NASA would provide an SLS launcher, the lander stack and most of the mission operations, ESA would provide the carrier-orbiter-relay platform and a stand-alone astrobiology module for the characterization of life at Europa's surface: the Astrobiology Wet Laboratory (AWL). Following this approach, JEM will be a major exciting joint venture to the outer Solar System of NASA and ESA, working together toward one of the most exciting scientific endeavours of the 21st century: to search for life beyond our own planet. © 2020, The authors received support from the sponsors of their home institutions during the development of their projects, particularly at the two institutes leading this effort: at IRAP, Toulouse, MB and NA acknowledge the support of CNRS, University Toulouse III - Paul Sabatier and CNES. At CAB, Madrid, OPB and JGE acknowledge the support of INTA and Spanish MINECO project ESP2014-55811-C2-1-P and ESP2017-89053-C2-1-P and the AEI project MDM-2017-0737 Unidad de Excelencia "Maria de Maeztu". We would also like to extend special thanks to the PASO of CNES for its precious assistance and expertise in the design of the mission scenario.

International audience; This paper reports on a combined experimental and numerical study dedicated to barrier reefs hydrodynamics. A network of pressure sensors and velocity profilers has been deployed for more than 2 months over the Ouano reef barrier, New Caledonia. The primary aim of the study is to assess the relevance of the classical depth‐averaged momentum balance in such a complex and poorly documented environment. The combined analysis of experimental and numerical measurements reveals a specific hydrodynamic behavior contrasting with sandy beaches and fringing reefs. The cross‐reef current induced by wave breaking over the barrier reef plays an important role in the momentum budget, in particular through friction processes. The hydrodynamic behavior over the barrier reef is thus characterized by the progressive transition from a nearly classical beach type behavior on the forereef, where the gradient of radiation stress is balanced by a barotropic pressure gradient associated to the wave setup, to an open‐channel type regime, dominated by frictional head loss. The reef top wave setup shows a clear depth dependency mainly attributed to the forereef curvature. During extreme wave events, the measurements tend to indicate a transition toward a critical hydraulic regime above the reef top. The numerical simulations, involving a non‐hydrostatic wave‐resolving model coupled to a urn:x-wiley:jgrc:media:jgrc23848:jgrc23848-math-0001 turbulence model, highlight the vertical structure of the flow. Over the reef flat, a classical log‐layer profile is observed, in agreement with measurements, while above the forereef an anticlockwise circulation develops under the breaking zone.

Noisy labeled data is more a norm than a rarity for self-generated content that is continuously published on the web and social media. Due to privacy concerns and governmental regulations, such a data stream can only be stored and used for learning purposes in a limited duration. To overcome the noise in this on-line scenario we propose QActor which novel combines: the selection of supposedly clean samples via quality models and actively querying an oracle for the most informative true labels. While the former can suffer from low data volumes of on-line scenarios, the latter is constrained by the availability and costs of human experts. QActor swiftly combines the merits of quality models for data filtering and oracle queries for cleaning the most informative data. The objective of QActor is to leverage the stringent oracle budget to robustly maximize the learning accuracy. QActor explores various strategies combining different query allocations and uncertainty measures. A central feature of QActor is to dynamically adjust the query limit according to the learning loss for each data batch. We extensively evaluate different image datasets fed into the classifier that can be standard machine learning (ML) models or deep neural networks (DNN) with noise label ratios ranging between 30% and 80%. Our results show that QActor can nearly match the optimal accuracy achieved using only clean data at the cost of at most an additional 6% of ground truth data from the oracle.

International audience; In this case study, high sensitivity simple methods for the analysis of trihalomethanes (THM4), iodinated-trihalomethanes (I-THMs), haloacetic acids (HAAs), bromide, iodide and iodate have been developed. A one-step procedure for the analysis of haloacetic acids by head-space GC–MS provides good reproducibility and low limits of quantification (≤50 ng L−1). These methods were applied to characterize the formation of disinfection by-products (DBPs) in a full scale drinking water treatment plant. In this treatment plant, the incorporation of bromine into THMs increases throughout the water treatment line, due to the formation of bromine reactive species favored by the decrease of competition between dissolved organic carbon (DOC) and bromide towards chlorine. A linear correlation has been observed between the bromine incorporation factor and the Br-/DOC mass ratio. The conversion of iodine to iodate by chlorination occurs in this water due to the relatively high bromide concentration. Moreover, a higher formation of iodate compared to iodide levels in the raw water is observed indicating a degradation of organic iodinated compounds. The formation of I-THMs was constant in terms of quantity and speciation between campaigns despite fluctuating concentrations of DOC and total iodine in the raw water. A preferential removal of DBPs formed by the intermediate chlorination in the order I-DBPs > Br-DBPs > Cl-DBPs occurs during the subsequent activated carbon filtration. The removal rates range from 25 to 36% for the regulated THM4, from 82 to 93% for the ∑I-THMs and 95% for haloacetic acids. The assessment of the relative toxicity shows that despite a much lower concentration of HAAs (

Significance Remote positioning and activation of drug-loaded microparticles in vivo are a central pursuit of nanomedicine. Optical, magnetic, and acoustic fields have been used to position and sort microparticles in vitro, but the translation in vivo remains challenging. Because sound can be transmitted centimeters deep into opaque media, acoustical tweezers are considered an ideal candidate for in vivo contactless manipulation. Here we use a single-beam acoustical trap to manipulate microbubbles in three dimensions through materials that mimic biological tissues. We establish the trapping mechanism, which is strikingly different from conventional acoustic trapping of bubbles. We also demonstrate controlled release from nanoparticle-loaded microbubbles with an independent acoustic trigger. We thus lay the foundations for biomedical applications of single-beam acoustical tweezers., Contactless manipulation of microparticles using acoustic waves holds promise for applications ranging from cell sorting to three-dimensional (3D) printing and tissue engineering. However, the unique potential of acoustic trapping to be applied in biomedical settings remains largely untapped. In particular, the main advantage of acoustic trapping over optical trapping, namely the ability of sound to propagate through thick and opaque media, has not yet been exploited in full. Here we demonstrate experimentally the use of the recently developed technique of single-beam acoustical tweezers to trap microbubbles, an important class of biomedically relevant microparticles. We show that the region of vanishing pressure of a propagating vortex beam can confine a microbubble by forcing low-amplitude, nonspherical, shape oscillations, enabling its full 3D positioning. Our interpretation is validated by the absolute calibration of the acoustic trapping force and the direct spatial mapping of isolated bubble echos, for which both find excellent agreement with our theoretical model. Furthermore, we prove the stability of the trap through centimeter-thick layers of bio-mimicking, elastic materials. Finally, we demonstrate the simultaneous trapping of nanoparticle-loaded microbubbles and activation with an independent acoustic field to trigger the release of the nanoparticles. Overall, using exclusively acoustic powering to position and actuate microbubbles paves the way toward controlled delivery of drug payloads in confined, hard-to-reach locations, with potential in vivo applications.

WOS:000571784700004; Power outages in electrical grids can have very negative economic and societal impacts rendering fault diagnosis paramount to their secure and reliable operation. In this paper, deep neural networks are proposed for fault detection and location in low-voltage smart distribution grids. Due to its key properties, the proposed method solves some of the drawbacks of the existing literature methods, namely a method that: 1) is not limited by the grid topology; 2) is branch-independent; 3) can localize faults even with limited data; 4) is the first to accurately detect and localize high-impedance faults in the low-voltage distribution grid. The generalizability of the method derives from the non-grid specific nature of the inputs that it requires, inputs that can be obtained from any grid. To evaluate the proposed method, a real low-voltage distribution grid in Portugal is considered and the robustness of the method is tested against several disturbances including large fault resistance values (up to 1000 ). Based on the case study, it is shown that the proposed methodology outperforms conventional fault diagnosis methods: it detects faults with 100% accuracy, identifies faulty branches with 83.5% accuracy, and estimates the exact fault location with an average error of less than 11.8%. Finally, it is also shown that: 1) even when reducing the available measurements to the bare minimum, the accuracy of the proposed method is only decreased by 4.5%; 2) while deep neural networks usually require large amounts of data, the proposed model is accurate even for small dataset sizes.

International audience; The research and improvement of methods to be used for deformation measurements from space is a challenge. From the previous 20 years, time series Synthetic Aperture Radar (SAR) interferometry techniques have proved for their ability to provide millimeter-scale deformation measurements over time. This paper aims to provide a review of such techniques developed in the last twenty years. We first recall the background of interferometric SAR (InSAR). We then provide an overview of the InSAR time series methods developed in the literature, describing their principles and advancements. Finally, we highlight challenges and future perspectives of the InSAR in the Big Data era.

International audience; We are delighted to welcome you to Nice, France, for ACM Multimedia 2019, the 27th ACM International Conference on Multimedia. ACM Multimedia is the premier international conference in the area of multimedia within the field of computer science. Since 1993, ACM Multimedia has been bringing together researchers and practitioners from academia and industry to present innovative research and discuss recent advancements.This year's conference delivers the cutting-edge research results, covering the latest findings in the field, for which the ACM Multimedia conference series is already widely known. In addition, we are offering some key innovations, which we would like to highlight in this welcome message.We are proud to introduce, for the first time at ACM Multimedia, a Reproducibility Track, whose goal is to incentivize and support researchers in sharing resources that will help others to reproduce their work. The track is dedicated to publishing papers that document the reproducibility of work that has previously appeared at ACM Multimedia, and implements the ACM Artifact Review and Badging system.Also, for the first time, the conference features a Sisters and Ambassadors session. This session provides a window on what is happening at other conferences of the SIGMM, as well as related conferences in other fields.It is a special pleasure to host an innovative networking event at the conference, called "Meet the Chairs". The event will bring together newcomers with established members of the community in a "ConfLab", which is a natural interaction activity, which simultaneously serves two goals: allowing people to get to know each other and also creating a multimodal data set. The data set will be made available to the community to study multimodal research questions related to human behavior and communication. ConfLab serves as a model for best practices in ethical sourcing of data for multimedia research.You will quickly notice that this year posters are a centerpiece of the conference. Reading posters and interacting with authors during poster sessions are a highly effective channel of communication of research results and discussion of findings. All conference papers will be presented as posters, which are hanging throughout the conference. We hope that you take advantage of the poster sessions, but also other breaks, to study the posters and to interact directly with the paper authors.During the oral sessions, selected papers will be presented as 10 minute presentations, followed by a question and answer period. Make good use of this opportunity to ask the authors about their work. Other papers will be presented as two minute "flash" presentations. These presentations will direct the audience to specific posters for further interaction with the authors. There is no status distinction between these presentation modes. Selection of presentation format for accepted papers is based on breadth of interest and topical balance of the program.Continuing ACM Multimedia's commitment to building diversity, this year's conference will feature a special conference-wide diversity event. Maria Menendez-Blanco and Pernille Bjørn of the Department of Computer Science, University of Copenhagen, Denmark, will make a presentation on their experiences in broadening the participation of women in computer science research. They will also offer an interactive installation, which supports discussions about inclusion in computer science, and actively contributes to building new perspectives beyond the narratives that currently dominate in our field.

International audience; SKIM is an ESA Earth Explorer-9 candidate mission designed to measure directly and simultaneously, for the first time, directional ocean surface current vector (OSCV) and ocean wave spectra. SKIM builds on satellite altimetry, including a nadir altimeter beam, and the first ocean wave spectrometer SWIM on CFOSAT. Using rotating beams across a 330 km swath, SKIM will explore beyond the 200 km - 15 days resolution of ocean currents that can be diagnosed today from sea level at mid latitudes. In particular SKIM will fill two important blind spots: in the tropics and in the marginal ice zone, and expand the effective space and time resolution of the altimeter constellation by a factor 2 or more. The novel direct measurement of surface currents in the top two meters will produce the first maps of the equatorial upwellings that are critical for understanding and forecasting the heat budget at the equator with far-reaching weather and climate consequences, for example on the African monsoon. OSCV maps will also allow the first monitoring of the highly dynamic currents at the ice edge. Adding this new and fundamental variable to Earth Observation capability together with high fidelity measurements of wave spectra will allow scientists to address a wide range of questions, including: How OSCV and waves influence upper ocean mixing and large scale circulation? How do OSCV and waves influence the dynamics of the ice edge in the Arctic and Antarctic?What are the roles of eddies, wind-driven flows and waves in setting the surface concentration of marine litter and shaping marine ecosystems?This presentation will explain how SKIM measurements will be used to address these scientific challenges using examples from mission and instrument simulator outputs.

Electroporation or electropermeabilization is a technique that enables transient increase in the cell membrane permeability by exposing cells to pulsed electric field. However, the molecular mechanisms of the long-lived cell membrane permeability, which persists on the minutes time scale after the pulse treatment, remain elusive. Experimental studies have suggested that lipid peroxidation could present a mechanism of this prolonged membrane permeabilization. In this study we make the first important step in quantifying the possible contribution of lipid peroxidation to electropermeabilization. We use free energy calculations to quantify the permeability and conductance of bilayers, containing an increasing percentage of hydroperoxide lipid derivatives, to sodium and chloride ions. We then compare our calculations to experimental measurements on electropermeabilized cells. Our results show that the permeability and conductance increase dramatically by several orders of magnitude in peroxidized bilayers. Yet this increase is not sufficient to reasonably account for the entire range of experimental measurements. Nevertheless, lipid peroxidation might be considered an important mechanism of prolonged membrane permeabilization, if exposure of cells to high voltage electric pulses leads to secondary lipid peroxidation products. Our analysis calls for experimental studies, which will determine the type and amount of lipid peroxidation products in electropermeabilized cell membranes.

International audience; The quality and quantity of natural organic matter (NOM) has been observed to evolve which poses challenges to water treatment facilities. Even though NOM may not be toxic itself, its presence in water has aesthetic effects, enhances biological growth in distribution networks, binds with pollutants and controls the bioavailability of trace metals. Even though NOM has heterogeneous functional groups, the predominant ones are the carboxyl and the phenolic groups, which have high affinities for metals depending on the pH. The properties of both the NOM and the trace elements influence the binding kinetics and preferences. Ca2+ prefers to bind with the carboxylic groups especially at a low pH while Zn2+ prefers the amine groups though practically, most cations bind to several functions groups. The nature of the chemical environment (neighboring ligands) the ligand finds itself equally influences its preference for a cation. The presence of NOM, cations or a complex of NOM-cations may have significant impact on the efficiency of water processes such as coagulation, adsorption, ion exchange resin and membrane filtration. In coagulation, the complexation between the coagulant salts and NOM helps to remove NOM from solution. This positive influence can further be enhanced by the addition of Ca2+. A negative influence is however, observed in lime-softening method as NOM complexes with Ca2+. A negative influence is also seen in membrane filtration where divalent cations partially neutralize the carboxyl functional groups of NOM thereby reducing the repulsion effect on NOM and increasing membrane fouling. The formation of disinfection by-products could either be increased or reduced during chlorination, the speciation of products formed is modified with generally the enhancement of haloacetic acid formation observed in presence of metal cations. This current work, presents in details the interactions of cations and NOM in the environment, the preference of cations for each functional group and the possible competition between cations for binding sites, as well as the possible impacts of the presence of cations, NOM, or their complex on water treatment processes.

The polarization state of starlight reflected by a planetary atmosphere uniquely reveals coverage, particle size, and composition of aerosols as well as changing cloud patterns. It is not possible to obtain a comparable level of detailed from flux-only observations. Furthermore, polarization observations can probe the atmosphere of planets independently of the orbital geometry (i.e., transiting and non-transiting planets). We show that a high-resolution spectropolarimeter with a broad wavelength coverage, particularly if attached to a large space telescope, would enable simultaneous study of the polarimetric exoplanet properties of the continuum and to look for and characterize the polarimetric signal due to scattering from single molecules.

International audience; In the present study, the nonlinear flexural bending of thick and thin porous curved composite beams reinforced and functionally graded by graphene platelets is carried out using a three-noded C1 continuous curved beam finite element developed introducing an efficient shear deformation theory based on trigonometric function. The nonlinearity through the strain–displacement relationship by introducing von Karman’s assumptions is considered. The nonlinear equilibrium equations resulting from minimum potential energy principle are numerically solved based on the direct iteration technique. The bending nonlinear features through the load–deflection relationship are presented by selecting various design parameters like long and short beams, shallow and deep curved cases, support conditions, the variation of graphene platelets in the metal foam and the existence of porosity. This investigation reveals that the level of nonlinearity gets noticeably affected by the depth coupled with the curved beam slenderness ratio.

The cooling dynamics of hot charge carriers in colloidal lead chalcogenide nanocrystals is studied by hyperspectral transient absorption spectroscopy. We demonstrate a transient accumulation of charge carriers at a high energy critical point in the Brillouin zone. Using a theoretical study of the cooling rate in lead chalcogenides, we attribute this slowing down of charge carrier cooling to a phonon scattering bottleneck around this critical point. The relevance of this observation for the possible harvesting of the excess energy of hot carriers by schemes such as multiexciton generation is discussed.

International audience; This paper is devoted to the simulation of dynamic brittle crack propagation in an isotropic medium. It focuses on cases where the crack deviates from a straight-line trajectory and goes through stop-and-restart stages. Our argument is that standard methods such as element deletion or remeshing, although easy to use and implement, are not robust tools for this type of simulation essentially because they do not enable one to assess local energy conservation. Standard cohesive zone models behave much better when the crack’s path is known in advance, but are difficult to use when the crack’s path is unknown. The simplest method which consists in placing the cohesive segments along the sides of the finite elements leads to crack trajectories which are mesh-sensitive. The adaptive cohesive element formulation, which adds new cohesive elements when the crack propagates, is shown to have the proper energy conservation properties during remeshing. We show that the X-FEM is a good candidate for the simulation of complex dynamic crack propagation. A two-dimensional version of the proposed X-FEM approach is validated against dynamic experiments on a brittle isotropic plate.

The combination of space-time block coding (STBC) and direct-sequence code-division multiple access (DS-CDMA) has the potential to increase the performance of multiple users in a cellular network. However, if not carefully designed, the resulting transmission scheme suffers from increased multiuser interference (MUI), which dramatically deteriorates the performance. To tackle this MUI problem in the downlink, we combine two specific DS-CDMA and STBC techniques, namely single-carrier block transmission (SCBT) DS-CDMA and time-reversal STBC. The resulting transmission scheme allows for deterministic maximum-likelihood (ML) user separation through low-complexity code-matched filtering, as well as deterministic ML transmit stream separation through linear processing. Moreover, it can achieve maximum diversity gains of N/sub T/N/sub R/(L+1) for every user in the system, irrespective of the system load, where N/sub T/ is the number of transmit antennas, N/sub R/ the number of receive antennas, and L the order of the underlying multipath channels. In addition, it turns out that a low-complexity linear receiver based on frequency-domain equalization comes close to extracting the full diversity in reduced, as well as full load settings. In this perspective, we also develop two (recursive) least squares methods for direct equalizer design. Simulation results demonstrate the outstanding performance of the proposed transceiver compared to competing alternatives.

Thresholdless stimulated emission is observed using nanometer sized colloidal HgTe nanocrystals, in a broad spectral region covering the entire technologically relevant near-infrared spectrum.