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Fault diagnosis via neural ordinary differential equations
No full textImplementation of model-based fault diagnosis systems can be a difficult task due to the complex dynamics of most systems, an appealing alternative to avoiding modeling is to use machine learning-based techniques for which the implementation is more affordable nowadays. However, the latter approach often requires extensive data processing. In this paper, a hybrid approach using recent developments in neural ordinary differential equations is proposed. This approach enables us to combine a natural deep learning technique with an estimated model of the system, making the training simpler and more efficient. For evaluation of this methodology, a nonlinear benchmark system is used by simulation of faults in actuators, sensors, and process. Simulation results show that the proposed methodology requires less processing for the training in comparison with conventional machine learning approaches since the data-set is directly taken from the measurements and inputs. Furthermore, since the model used in the essay is only a structural approximation of the plant; no advanced modeling is required. This approach can also alleviate some pitfalls of training data-series, such as complicated data augmentation methodologies and the necessity for big amounts of data. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.Fondo Nacional de Desarrollo Científico y Tecnológico - Fondecy
The potential role of news media to construct a machine learning based damage mapping framework
No full textWhen flooding occurs, Synthetic Aperture Radar (SAR) imagery is often used to identify flood extent and the affected buildings for two reasons: (i) for early disaster response, such as rescue operations, and (ii) for flood risk analysis. Furthermore, the application of machine learning has been valuable for the identification of damaged buildings. However, the performance of machine learning depends on the number and quality of training data, which is scarce in the aftermath of a large scale disaster. To address this issue, we propose the use of fragmentary but reliable news media photographs at the time of a disaster and use them to detect the whole extent of the flooded buildings. As an experimental test, the flood occurred in the town of Mabi, Japan, in 2018 is used. Five hand-engineered features were extracted from SAR images acquired before and after the disaster. The training data were collected based on news photos. The date release of the photographs were considered to assess the potential role of news information as a source of training data. Then, a discriminant function was calibrated using the training data and the support vector machine method. We found that news information taken within 24 h of a disaster can classify flooded and nonflooded buildings with about 80% accuracy. The results were also compared with a standard unsupervised learning method and confirmed that training data generated from news media photographs improves the accuracy obtained from unsupervised classification methods. We also provide a discussion on the potential role of news media as a source of reliable information to be used as training data and other activities associated to early disaster response. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.Consejo Nacional de Ciencia, Tecnología e Innovación Tecnológica - Concyte
Towards an ontology for urban tourism
No full textNowadays, diffusion and preservation of cultural heritage are being supported by technology on the Web. Thus, the online availability of urban tourism information, as part of cultural heritage, has been of enormous relevance to activate the tourism in many countries. The necessity of a well-defined and standard model for representing this knowledge is being managed by semantic web technologies, such as ontologies. However, current proposals represent partial knowledge of cultural heritage. In this context, this work proposes an ontology for indoor and outdoor environments of a city to represent the cultural heritage knowledge based on the UNESCO definitions. This ontology has a three-level architecture (Upper, Middle, and Lower ontologies) in accordance with a purpose of modularity and levels of specificity. To demonstrate the utility and suitability of our proposal, we have developed a parser to map and convert a museum repository (in CSV format) to RDF triples. With this case of study, we demonstrated that, by using our ontology, it is possible to represent the knowledge of urban tourism domains of a city. © 2021 Owner/Author.Consejo Nacional de Ciencia, Tecnología e Innovación Tecnológica - Concyte
Design and construction of a portable apparatus to measure thermal conductivity
No full textThe characterization of the thermal insulation properties of construction materials represents a fundamental step on building insulation assessment. The present work aims to design and build a portable apparatus, namely, Portable LAMBDA UNI, capable of measuring the thermal conductivity of insulation materials. This portable apparatus is based on the standard ASTM C 518, which is a secondary method for measuring thermal conductivity. The apparatus also measures the effective thermal conductivity of square prism thermal insulation materials of 60 mm per side and a maximum thickness of 14 mm. The thermal conductivity of the drywall and adobe with Stipa ichu was measured with the Portable LAMBDA UNI, with the values being 0.265 W m-1 K-1and 0.357 W m-1 K-1, respectively. © 2021 Published under licence by IOP Publishing Ltd.Consejo Nacional de Ciencia, Tecnología e Innovación Tecnológica - Concyte
Multifaceted Mechanism of Amicoumacin A Inhibition of Bacterial Translation
No full textAmicoumacin A (Ami) halts bacterial growth by inhibiting the ribosome during translation. The Ami binding site locates in the vicinity of the E-site codon of mRNA. However, Ami does not clash with mRNA, rather stabilizes it, which is relatively unusual and implies a unique way of translation inhibition. In this work, we performed a kinetic and thermodynamic investigation of Ami influence on the main steps of polypeptide synthesis. We show that Ami reduces the rate of the functional canonical 70S initiation complex (IC) formation by 30-fold. Additionally, our results indicate that Ami promotes the formation of erroneous 30S ICs; however, IF3 prevents them from progressing towards translation initiation. During early elongation steps, Ami does not compromise EF-Tu-dependent A-site binding or peptide bond formation. On the other hand, Ami reduces the rate of peptidyl-tRNA movement from the A to the P site and significantly decreases the amount of the ribosomes capable of polypeptide synthesis. Our data indicate that Ami progressively decreases the activity of translating ribosomes that may appear to be the main inhibitory mechanism of Ami. Indeed, the use of EF-G mutants that confer resistance to Ami (G542V, G581A, or ins544V) leads to a complete restoration of the ribosome functionality. It is possible that the changes in translocation induced by EF-G mutants compensate for the activity loss caused by Ami. © Copyright © 2021 Maksimova, Vinogradova, Osterman, Kasatsky, Nikonov, Milón, Dontsova, Sergiev, Paleskava and Konevega.Consejo Nacional de Ciencia, Tecnología e Innovación Tecnológica - Concyte
Mesenchymal Stromal Cell-Based Therapies as Promising Treatments for Muscle Regeneration After Snakebite Envenoming
No full textSnakebite envenoming is a global neglected disease with an incidence of up to 2.7 million new cases every year. Although antivenoms are so-far the most effective treatment to reverse the acute systemic effects induced by snakebite envenoming, they have a limited therapeutic potential, being unable to completely neutralize the local venom effects. Local damage, such as dermonecrosis and myonecrosis, can lead to permanent sequelae with physical, social, and psychological implications. The strong inflammatory process induced by snake venoms is associated with poor tissue regeneration, in particular the lack of or reduced skeletal muscle regeneration. Mesenchymal stromal cells (MSCs)-based therapies have shown both anti-inflammatory and pro-regenerative properties. We postulate that using allogeneic MSCs or their cell-free products can induce skeletal muscle regeneration in snakebite victims, improving all the three steps of the skeletal muscle regeneration process, mainly by anti-inflammatory activity, paracrine effects, neovascularization induction, and inhibition of tissue damage, instrumental for microenvironment remodeling and regeneration. Since snakebite envenoming occurs mainly in areas with poor healthcare, we enlist the principles and potential of MSCs-based therapies and discuss regulatory issues, good manufacturing practices, transportation, storage, and related-procedures that could allow the administration of these therapies, looking forward to a safe and cost-effective treatment for a so far unsolved and neglected health problem. © Copyright © 2021 Sanchez-Castro, Pajuelo-Reyes, Tejedo, Soria-Juan, Tapia-Limonchi, Andreu, Hitos, Martin, Cahuana, Guerra-Duarte, de Assis, Bedoya, Soria, Chávez-Olórtegui and Tejedo.Consejo Nacional de Ciencia, Tecnología e Innovación Tecnológica - Concyte
Electrochemical sensor based on 1,8-dihydroxyanthraquinone adsorbed on a glassy carbon electrode for the detection of [Cu(CN)3](aq)2− in alkaline cyanide copper plating baths waste
No full textThis work reports the fabrication of a novel electrochemical sensor for the detection of the complex ion [Cu(CN)3](aq)2−, one of the main components of the effluents from cyanide alkaline copper plating baths. This sensor was prepared by using a surface modified glassy carbon (GC) electrode with 1,8-dihydroxyantroquinone (1,8-DHAQ). It was characterized by electrochemical impedance, Raman spectroscopy and UV–Visible spectroscopy. The electrochemical detection of [Cu(CN)3](aq)2−was performed by differential pulse voltammetry. The 1,8-DHAQ/GC electrochemical sensor exhibits good reproducibility and a linear range of 5.50 × 10−7–3.81 × 10−6 mol L−1, with a detection limit (LOD) of 1.20 × 10−6 mol L−1, quantification limit (LOQ) of 3.97 × 10−6 mol L−1, and robustness to interfering Cl−, NO3−, SO42− y CO32− ions. Finally, a DFT approach suggests an almost parallel orientation of the bis(1,8-dihydroxyanthraquinone) over a graphene domain of the glassy carbon surface, as well as the noncovalent nature of the interactions involved. © 2020Fondo Nacional de Desarrollo Científico y Tecnológico - Fondecy
Nasal compartmentalization in Kogiidae (Cetacea, Physeteroidea): insights from a new late Miocene dwarf sperm whale from the Pisco Formation
No full textFacial compartmentalization in the skull of extant pygmy whales (Kogiidae) is a unique feature among cetaceans that allows for the housing of a wide array of organs responsible for echolocation. Recent fossil findings indicate a remarkable disparity of the facial bone organization in Miocene kogiids, but the significance of such a rearrangement for the evolution of the clade has been barely explored. Here we describe Kogia danomurai sp. nov., a late Miocene (c. 5.8 Ma) taxon from the Pisco Formation (Peru), based on a partially preserved skull with a new facial bone pattern. Phylogenetic analysis recovers K. danomurai as the most basal representative of the extant genus Kogia, displaying a combination of derived (incipiently developed and excavated sagittal facial crest) and plesiomorphic features (high position of the temporal fossa, and antorbital notch not transformed into a narrow slit). Furthermore, when compared with the extant Kogia, the facial patterning found in K. danomurai indicates differential development among the facial organs, implying different capabilities of sound production relative to extant Kogia spp. Different facial bone patterns are particularly notable within the multi-species kogiid assemblage of the Pisco Formation, which suggests causal connections between different patterns and feeding ecologies (e.g. nekton piscivory and benthic foraging). At c. 5.8 Ma, K. danomurai was part of a cetacean community composed of clades typical of the late Miocene, and of other early representatives of extant taxa, a mixture probably representing an initial shift of the coastal faunas toward the ecosystem dynamics of the present-day south-eastern Pacific. © 2021 The Palaeontological AssociationConsejo Nacional de Ciencia, Tecnología e Innovación Tecnológica - Concyte
Antimicrobial peptides purified from hydrolysates of kanihua (Chenopodium pallidicaule Aellen) seed protein fractions
No full textCIENCIACTIVA-CONCYTEC funded this research under contract 007-2014-FONDECYT. The professional collaboration and unconditional support of the Business administrator Pawel Moscoso-Mujica in carrying out the research are appreciated.The kanihua (Chenopodium pallidicaule Aellen) Andean grain from the Peruvian Altiplano presents proteins of 15% to 19%. The objective was to obtain purified bioactive antimicrobial peptides (AMPs), hydrolyzed with Alcalase and Pepsin-pancreatin sequential system of protein fractions of kanihua varieties Ramis (KR) and CupiSayhua (KS), and hydrolysates with different degrees of hydrolysis (DH) and percentage inhibition (IP) of the growth of E. coli, S. aureus, and C. albicans. To obtain AMPs, nutraceuticals, bio-preservatives, and novel ingredients in food design. The results showed 216 hydrolysates (1%, w/v), only 28 presented significant difference compared to controls (IP 0.05), and presented an anionic charge. In conclusion, the simulated digestion in vitro showed higher DH (7%-67%) than Alcalase (13%-54%); the majority were extensive; of 28 hydrolysates with IP 45% 4 AMPs with important IPs were obtained, and one was anionic.Consejo Nacional de Ciencia, Tecnología e Innovación Tecnológica - Concyte
Improvement of mechanical properties of hydroxyapatite composites reinforced with i-Al64Cu23Fe13 quasicrystal
No full textThe author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: J.C.-V. thanks to Circulo de Investigacion e Innovacion de Materiales Avanzados para la Industria y Biomedicina of FONDECYT (CONCYTEC) under grant No 011-2014-FONDECYT, and to the Brazilian Society of Physics (PLAF program) that financed part of this work. C. V.L., J.Q.-M. and V.P.R. are grateful to FONDECYT (CONCYTEC) for financial support through the Excellence Center Program.Mechanical behavior of hydroxyapatite-based composites (HAp) was studied as a function of the reinforcement concentration of the quasicrystalline (QC) Al64Cu23Fe13 alloy. The synthesis of the HAp matrix was carried out by sol-gel method, while the synthesis of the QC was performed by an arc furnace with a subsequent thermal treatment. The composites were made by powder metallurgy and cold compacted to form test pieces that were sintered with a constant flow of argon. The materials were characterized using X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy and Fourier transform Raman spectroscopy. The study of mechanical strength was carried through compression tests. The biocompatibility of the composites was tested using an in-vitro cytotoxicity assay. The mechanical resistance of HAp/QC composites increased with the concentration of quasicrystalline reinforcement. Young's modulus and compressive strength increased in 43% and 21%, respectively, with a 10 wt% QC reinforcement, which demonstrates an hybrid behaviour of the composite due to the inclusion of reinforcing particles in the pores of the matrix. This composite did not show cytotoxicity at any of the QC concentrations. A fabrication route is proposed as a fast, easy and high efficiency alternative for applications in the biomedical industry because of its high scalability potential.Consejo Nacional de Ciencia, Tecnología e Innovación Tecnológica - Concyte