909 research outputs found

    Coleopterans Associated with Plants that form Phytotelmata in Subtropical and Temperate Argentina, South America

    Get PDF
    A list of the most common plants that form phytotelmata and their associated coleopterans (aquatic, semi-aquatic and terrestrial) from the northeastern subtropical and temperate area of Argentina, South America with biological and behavioral observations is presented in this study. Species of Poaceae (n = 3), Bromeliaceae (5), Apiaceae (6), Araceae (2), Urticaceae (1), Marantaceae (1), Arecaceae (1), Dipsacaceae (1) and Cyperaceae (1) were identified as phytotelmata. Aquatic species of Scirtidae (2), Dytiscidae (2), and Hydrophilidae (4), semi-aquatic Chelonariidae (2), and terrestrial species of Carabidae (3), Staphylinidae (5), Histeridae (1), Elateridae (1), Cantharidae (1), Cleridae (1), Tenebrionidae (1), Meloidae (1), Anthicidae (1), Chrysomelidae (3), Curculionidae (7) and Apionidae (1) were identified from six species of Eryngium L. (Apiales: Apiaceae), two species of Guadua Kunth (Poales: Poaceae), Aechmea distichantha Lemaire (Poales: Bromeliaceae), and from fallen leaves of Euterpe edulis Martius (Arecales: Arecaceae) from the temperate and subtropical area. The highest species richness was recorded in Eryngium phytotelmata. Fifteen species of beetles inhabit Eryngium cabrerae Pontiroli, 11 in E. horridum Malme, 7 in E. stenophyllum Urban, 4 in E. aff. serra Chamisso and Schlechtendal., 3 in E. elegans Chamisso and Schlechtendal, 2 in E. eburneum Decne and E. pandanifolium Chamisso and Schlechtendal. From bamboo, 6 species of coleopterans were collected from Guadua trinii (Nees) Nees ex Ruprecht and 4 from G. chacoensis (Rojas) Londoño and Peterson. Three species of aquatic coleopterans were recorded from A. distichantha and only one from E. edulis

    A new approach to modelling the impact of EMI on MOSFET DC behavior

    Get PDF
    A simple analytical model to predict the DC MOSFET behavior under electromagnetic interference (EMI) is presented. The model is able to describe the MOSFET performance in the linear and saturation regions under EMI disturbance applied to the gate. The model consists of a unique simple equivalent circuit based on a voltage dependent current source and a reduced number of parameters which can accurately predict the drift on the drain current due to the EMI source. The analytical approach has been validated by means of electric simulation and mesaurement and can be easily introduced in circuit simulators. The proposed modeling technique combined with the nth-power law model of the MOSFET without EMI, significantyly improves its accuracy in comparison with the n-th power law directy applied to a MOSFET under EMI impact.Peer ReviewedPostprint (published version

    OBOE: an Explainable Text Classification Framework

    Get PDF
    Explainable Artificial Intelligence (XAI) has recently gained visibility as one of the main topics of Artificial Intelligence research due to, among others, the need to provide a meaningful justification of the reasons behind the decision of black-box algorithms. Current approaches are based on model agnostic or ad-hoc solutions and, although there are frameworks that define workflows to generate meaningful explanations, a text classification framework that provides such explanations considering the different ingredients involved in the classification process (data, model, explanations, and users) is still missing. With the intention of covering this research gap, in this paper we present a text classification framework called OBOE (explanatiOns Based On concEpts), in which such ingredients play an active role to open the black-box. OBOE defines different components whose implementation can be customized and, thus, explanations are adapted to specific contexts. We also provide a tailored implementation to show the customization capability of OBOE. Additionally, we performed (a) a validation of the implemented framework to evaluate the performance using different corpora and (b) a user-based evaluation of the explanations provided by OBOE. The latter evaluation shows that the explanations generated in natural language express the reason for the classification results in a way that is comprehensible to non-technical users

    Correlation between Ct-values and symptoms of COVID-19 patients

    Get PDF
    Background: Currently available RT-PCR methods for the diagnosis of COVID-19 can give an estimate of the viral load. The cycle threshold value (Ct-value) of the PCR correlates inversely with the viral load; low Ct-values indicate high viral loads and vice versa. Higher viral loads have been seen to correlate with disease severity and infectivity. Therefore, we studied the correlation of the Ct-value of RT-PCR and the most common symptoms of COVID-19 individually. Methods: A prospective and descriptive study was carried out with the subjects that attended our laboratory for a COVID-19 test from September 14, 2020, to January 30, 2021. Subjects filled out a questionnaire with demographic and clinical information prior to taking the naso and oropharyngeal samples. The samples were processed by Vircell SARS-CoV-2 Real-time PCR Kit (Granada, Spain). Statistical analyses were performed using IBM SPSS software. Results: We included 657 positive subjects with complete information, with a median age of 36 (27-47) and a male predominance of 477 (72.6%). Of these, 395 (60.1%) were symptomatic and the median number of symptoms was 2 (0-5). The most predominant symptoms were headache 271 (68.6%), cough 229 (58%), and myalgias 180 (45.6%). The median Ct-value for gene N was 30 (23-36) and for gene E was 31 (23-35). In comparison between symptomatic and asymptomatic subjects, asymptomatic patients had a higher Ct-value (lower viral load) in both genes and a lower age (p Conclusions: The viral load correlates with symptoms within COVID-19, having found that higher viral loads were correlated with symptoms such as headache, cough, and fever, while lower viral loads were correlated with dyspnea, diarrhea, and alterations of smell or taste senses

    Three-dimensional linear peeling-ballooning theory in magnetic fusion devices

    Get PDF
    Ideal magnetohydrodynamics theory is extended to fully 3D magnetic configurations to investigate the linear stability of intermediate to high n peeling-ballooning modes, with n the toroidal mode number. These are thought to be important for the behavior of edge localized modes and for the limit of the size of the pedestal that governs the high confinement H-mode. The end point of the derivation is a set of coupled second order ordinary differential equations with appropriate boundary conditions that minimize the perturbed energy and that can be solved to find the growth rate of the perturbations. This theory allows of the evaluation of 3D effects on edge plasma stability in tokamaks such as those associated with the toroidal ripple due to the finite number of toroidal field coils, the application of external 3D fields for elm control, local modification of the magnetic field in the vicinity of ferromagnetic components such as the test blanket modules in ITER, etc.This research was sponsored in part by DGICYT (Dirección General de Investigaciones Científicas y Tecnológicas) of Spain under Project No. ENE2012-38620-C02-02 and also in part by Comunidad de Madrid Project No. S2009/ENE-1679.Publicad

    On Some Sampling-Related Frames in U-Invariant Spaces

    Get PDF
    This paper is concerned with the characterization as frames of some sequences in -invariant spaces of a separable Hilbert space H where U denotes an unitary operator defined on H ; besides, the dual frames having the same form are also found. This general setting includes, in particular, shift-invariant or modulation-invariant subspaces in L2(R) , where these frames are intimately related to the generalized sampling problem. We also deal with some related perturbation problems. In doing so, we need the unitary operator to belong to a continuous group of unitary operators

    Insights into coacervative and dispersive liquid-phase microextraction strategies with hydrophilic media - a review

    Get PDF
    Since the development of liquid-phase microextraction (LPME), different LPME modes depending on the experimental set-up to carry out the extraction have been described. Dispersive liquid-liquid microextraction (DLLME), in which a small amount of the water-insoluble extraction solvent is dispersed in the sample, is the most successful mode in terms of number of applications reported. Advances within DLLME have been mainly shifted to the incorporation of green, smart and tunable materials as extraction solvents to improve the sustainability and efficiency of the method. In this sense, hydrophilic media represent a promising alternative since the water-miscibility of these substances increases the mass transfer of the analytes to the extraction media, leading to higher extraction efficiencies. Considering the variety of hydrophilic media that have been incorporated in LPME approaches resembling DLLME, this review aims to classify these methods in order to clarify the confusing terminology used for some of the strategies. Hydrophilic media covered in this review comprise surfactants, polar organic solvents, deep eutectic solvents, ionic liquids, water-miscible polymers, and switchable solvents. Different physicochemical mechanisms of phase separation are discussed for each LPME method, including the coacervation phenomena and other driving forces, such as pH, temperature, salting-out effect, metathesis reaction and organic solvents. LPME modes are classified (in cloud-point extraction, coacervative extraction, aqueous biphasic systems, and different DLLME modes depending on the extraction medium) according to both the nature of the water-miscible extraction phase and the driving force of the separation. In addition, the main advances and analytical applications of these methods in the last three years are described.publishe

    Autonomous navigation and obstacle avoidance of a micro-bus: Regular paper

    Get PDF
    At present, the topic of automated vehicles is one of the most promising research areas in the field of Intelligent Transportation Systems (ITS). The use of automated vehicles for public transportation also contributes to reductions in congestion levels and to improvements in traffic flow. Moreover, electrical public autonomous vehicles are environmentally friendly, provide better air quality and contribute to energy conservation. The driverless public transportation systems, which are at present operating in some airports and train stations, are restricted to dedicated roads and exhibit serious trouble dynamically avoiding obstacles in the trajectory. In this paper, an electric autonomous mini-bus is presented. All datasets used in this article were collected during the experiments carried out in the demonstration event of the 2012 IEEE Intelligent Vehicles Symposium that took place in Alcalá de Henares (Spain). The demonstration consisted of a route 725 metres long containing a list of latitude-longitude points (waypoints). The mini-bus was capable of driving autonomously from one waypoint to another using a GPS sensor. Furthermore, the vehicle is provided with a multi-beam Laser Imaging Detection and Ranging (LIDAR) sensor for surrounding reconstruction and obstacle detection. When an obstacle is detected in the planned path, the planned route is modified in order to avoid the obstacle and continue ist way to the end of the mission. On the demonstration day, a total of 196 attendees had the opportunity to get a ride on the vehicles. A total of 28 laps were successfully completed in full autonomous mode in a private circuit located in the National Institute for Aerospace Research (INTA), Spain. In other words, the system completed 20.3 km of driverless navigation and obstacle avoidance

    Analysis of the oscillations induced by a supersonic jet applied to produce nanofibers

    Get PDF
    Financiado para publicación en acceso aberto: Universidade de Vigo/CISUGHigh-performance fibers are key components for enhancing the mechanical properties of composite materials. The development of high strength nanofibers augurs the production of new nano-composites with outstanding features. However, the robust production of continuous glass nanofibers that can be feasible processed for efficiently manufacturing nanocomposites is still challenging. Recently, Cofiblas (Continuous Fiberizing by Laser melting and Supersonic dragging) was demonstrated as a technique capable of producing continuous glass nanofibers with unlimited length. Cofiblas process has some similarities with the widely known melt blowing technique for the production of polymeric fibers. In both techniques, the design of the gas nozzle is key to ensure the feasibility of the process since the turbulences of the gas jet may induce strong whipping of the filament. This paper gives novel experimental evidences on the correlation of the supersonic gas jet instabilities with the oscillation of the filament in the melt-blowing and Cofiblas processes, relating these oscillations with the presence of shock waves and unsteadiness in the flow, and gives valuable insight into the use of supersonic jets in the melt blowing process as an effective approach for the formation of nanofibers. A thin 3D-axisymmetric model in OpenFOAM® was put to test by comparing the performance of different solvers which were validated by flow visualization of the exit jet using digital holography (DH). In order to perform a realistic and thorough validation, we simulated the optical measurements of the flow from the CFD simulations of the mass density by Abel transform and numerical differentiation. The application of digital holography as the flow visualization technique makes possible both a precise validation of the density maps obtained from the Abel transformation of the 2D-alike results, and the analysis of the shockwave pattern in the air jet. Conversely, the numerical reconstruction of time-averaged holograms is employed to detect unsteadiness in the flow and to analyze the fiber oscillation, which is essential to assess the stability of the process. Lastly, the analysis and comparison of the vibration of the filament using the basic design and the optimized nozzle demonstrates a clear influence of the shock waves and flow unsteadiness in the stability of the filament.Agencia Estatal de Investigación | Ref. PGC2018-094900-B-I00Xunta de Galicia | Ref. ED431C 2019/23Ministerio de Universidades | Ref. FPU20/0311
    corecore