1,425 research outputs found

    Identification of the key excreted molecule by Lactobacillus fermentum related to host iron absorption

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    We have taken a vital step towards understanding why probiotic bacteria increase iron absorption in the gastrointestinal tract. We show here that Lactobacillus fermentum, one of the main probiotics of the microbiota, exhibits an extraordinary ferric-reducing activity. This activity is predominantly due to an excreted molecule: p-hydroxyphenyllactic acid (HPLA). Reduction of Fe(III) to Fe(II) is essential for iron absorption in the gastrointestinal tract. By reducing Fe(III), HPLA boosts Fe(II) absorption through the DMT1 channels of enterocytes. An in vitro experiment tested and confirmed this hypothesis. This discovery opens new avenues for the treatment of iron deficiency in humans, one of the most common and widespread nutritional disorders in the world

    Dynamic Federated Learning Model for Identifying Adversarial Clients

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    Federated learning, as a distributed learning that conducts the training on the local devices without accessing to the training data, is vulnerable to dirty-label data poisoning adversarial attacks. We claim that the federated learning model has to avoid those kind of adversarial attacks through filtering out the clients that manipulate the local data. We propose a dynamic federated learning model that dynamically discards those adversarial clients, which allows to prevent the corruption of the global learning model. We evaluate the dynamic discarding of adversarial clients deploying a deep learning classification model in a federated learning setting, and using the EMNIST Digits and Fashion MNIST image classification datasets. Likewise, we analyse the capacity of detecting clients with poor data distribution and reducing the number of rounds of learning by selecting the clients to aggregate. The results show that the dynamic selection of the clients to aggregate enhances the performance of the global learning model, discards the adversarial and poor clients and reduces the rounds of learning.Comment: 11 pages, 6 figure

    Alimentos diferenciados por atributos de producto y de procesos: una experiencia de investigación socio-económica integrada a los aspectos integrada a los aspectos agronómicos

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    Fil: Rodríguez, Elsa Mirta M. Universidad Nacional de Mar del Plata. Facultad de Ciencias Económicas y Sociales; Argentina.Fil: Lacaze, María Victoria. Universidad Nacional de Mar del Plata. Facultad de Ciencias Económicas y Sociales; Argentina.Fil: Lupín, Beatriz. Universidad Nacional de Mar del Plata. Facultad de Ciencias Económicas y Sociales; Argentina.Fil: González, Julia. Universidad Nacional de Mar del Plata. Facultad de Ciencias Económicas y Sociales; Argentina

    454-Pyrosequencing Analysis of Bacterial Communities from Autotrophic Nitrogen Removal Bioreactors Utilizing Universal Primers: Effect of Annealing Temperature

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    Identification of anaerobic ammonium oxidizing (anammox) bacteria by molecular tools aimed at the evaluation of bacterial diversity in autotrophic nitrogen removal systems is limited by the difficulty to design universal primers for the Bacteria domain able to amplify the anammox 16S rRNA genes. A metagenomic analysis (pyrosequencing) of total bacterial diversity including anammox population in five autotrophic nitrogen removal technologies, two bench-scale models (MBR and Low Temperature CANON) and three full-scale bioreactors (anammox, CANON, and DEMON), was successfully carried out by optimization of primer selection and PCR conditions (annealing temperature). The universal primer 530F was identified as the best candidate for total bacteria and anammox bacteria diversity coverage. Salt-adjusted optimum annealing temperature of primer 530F was calculated (47°C) and hence a range of annealing temperatures of 44–49°C was tested. Pyrosequencing data showed that annealing temperature of 45°C yielded the best results in terms of species richness and diversity for all bioreactors analyzed

    Catalytic activity of iridium NHC complexes covalently bonded to carbon nanotubes and graphene oxide

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    Trabajo presentado a la Annual World Conference on Carbon, celebrada en Dresden (Alemania) del 12 al 17 de julio de 2015.Carbon nanotubes and graphene have been extensively applied as proactive supports to generate heterogeneous catalysts. Both exhibit a carbon structure composed by carbon atoms with sp2 hybridization and both are used in similar applications, as in catalysis. However, the role of each particular substrate, determined by its structural peculiarities, can be differentvshould be studied for each particular catalytic reaction and in their structure.The aim of this work is to study the differences between oxidized carbon nanotubes (CNT) and graphene oxides (GO) as proactive supports of iridium Nheterocyclic carbene (NHC) catalyst. The effect of their inherent structure in the catalytic activity in hydrogen transfer reactions was studied in detail.The authors thank MINECO/MECD (Projects CONSOLIDER INGENIO 2010 CSD2009-00050, CTQ 2010-15221, Ramón y Cajal contract of P. Alvarez and fellowship of M. Blanco) and the Diputación General de Aragón (E07) for their financial support.Peer Reviewe

    Thermoelectric properties and intrinsic conduction processes in DBSA and NaSIPA doped polyanilines

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    Seeking to gain fundamental understanding of the thermoelectric (TE) behavior of polyanilines (PANIs), structure- property relationships of PANI nanorods, doped with dodecylbenzenesulfonic acid (DBSA) and 5-sulfoisophtalic acid sodium salt (NaSIPA), and prepared by an indirect synthetic route, are discussed in terms of the contribution of the acid concentrations on the thermoelectric properties. The synergistic combination of high doping level and layer structure, accounts for the moderately high electrical conductivities (σ) and low constant Seebeck coefficients (α) of PANI-DBSA. Conversely, the poor doping ability of NaSIPA and low crystallinity degree explain the low electrical conductivities along with significant increases in Seebeck coefficient values. In relation to conduction mechanisms, PANI-DBSA shows a hopping behavior with a carrier concentration of c≈0.49 (hole type), while PANI-NaSIPA displays a diffusive regime, characteristic of degenerate metallic semiconductors, with an estimated charge carrier density of n≈3 × 1021 e/cm3

    5G spatial modeling of personal RF-EMF assessment within aircrafts cabin environments

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    Recently, new wireless communication systems within aircrafts cabins have drawn higher attention due to the growing demand of passenger services and applications and their corresponding requirements and constraints. In this regard, the fifth generation (5G) of wireless communication becomes an attractive and promising alternative to enable aircraft passengers' comfort and entertainment along the flight, considering its potential benefits in term of high data transfers and low latencies. Nevertheless, general population concern about radio frequency electromagnetic fields (RF-EMF) safety in general and, in particular to the environmental exposure at which we are all exposed in these flights, increases at the same time. Thus, in this work, we present an experimental campaign of measurements for current passengers' environmental exposure assessment, performed in different real generalizable type of flights and aircrafts' cabins, in order to provide current RF-EMF exposure insight within these complex heterogeneous environments. In addition, worst-case uplink 5G scenarios, where all 5G cellular handsets of the passengers operate at the same time, have been simulated by means of an in-house developed 3D Ray Launching (3D-RL) deterministic technique. Before takeoff and after landing, critical scenarios with the aircrafts' doors closed have been selected and assessed considering different types of modeled aircrafts full of passengers, considering 5G frequency range 2 (5G-FR2) operating links. The obtained results show that the operation frequency and the morphology and topology of the aircraft cabin have a great influence in the environmental RF-EMF passengers' spatial distribution and overall exposure, but not exceeding, even in worst case conditions, the international established regulatory limits. © 2022 IEEE.This work was supported by the Ministerio de Ciencia, Innovación y Universidades, Gobierno de España (MCIU/AEI/FEDER, UE) under Project RTI2018-095499-B-C31
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