bluuebunny/crossref_metadata_2025 huggingface dataset:
Bayesian Probability and Tanimoto Based Recurrent Neural Network for Question Answering System
Authors: Jagannathan Veeraraghavan
Published: July 2021

Question Answering (QA) has become one of the most significant information retrieval applications. Despite that, most of the question answering system focused to increase the user experience in finding the relevant result. Due to the continuous increase of web content, retrieving the relevant result faces a challenging issue in the Question Answering System (QAS). Thus, an effective Question Classification (QC), and retrieval approach named Bayesian probability and Tanimoto-based Recurrent Neural Network (RNN) are proposed in this research to differentiate the types of questions more efficiently. This research presented an analysis of different types of questions with respect to the grammatical structures. Various patterns are identified from the questions and the RNN classifier is used to classify the questions. The results obtained by the proposed Bayesian probability and Tanimoto-based RNN showed that the syntactic categories related to the domain-specific types of proper nouns, numeral numbers, and the common nouns enable the RNN classifier to reveal better result for different types of questions. However, the proposed approach obtained better performance in terms of precision, recall, and F-measure with the values of 90.14, 86.301, and 90.936 using dataset-2.
Key Distribution Strategy of Wireless Sensor Network Based on Multi-Hash Chain
Authors: Xiong Peng , Su Qinggang
Published: July 2021

Key management is the basis of the security mechanism for wireless sensor networks and services, and random key pre-distribution is the most effective key management mechanism at present. However, there is a potential challenge to most current random key pre-distribution strategies: it is difficult to achieve both ideal network security connectivity and network survivability. In this paper, we present a novel random key pre-distribution scheme based on the hash chain. By adjusting certain system parameters, such as the hash chain length, the number of common auxiliary nodes and the number of hash chains, a sensor node only need to preload a few of keys, making it possible to establish the pairwise key with high probability among its neighboring nodes. The proposed scheme can still maintain strong network survivability even if there are many compromised nodes. The theoretical analysis and simulation experiments show that the proposed scheme is not only effective and secure, but also scalable.
Integration of “Offline + Online” Teaching Method of College English Based on Web Search Technology
Authors: Bian Lijun
Published: July 2021

The change of social demand for English application-oriented talents has affected the transformation of the way of cultivating talents in College English. The traditional training mode of indoctrination has exposed more and more disadvantages, and the demand of new teaching mode is imminent. This paper first analyzes the current situation of College English learning platform in China. Then, it discusses the design and implementation of “Online + offline” College English learning platform based on Web. The overall structure and function of the database are designed in detail. The teaching platform provides students with learning tools, learning resources, communication platform, testing and evaluation functions, and can evaluate students’ learning behavior, learning process and learning effect. This paper traces and collects a large amount of data left by learners in learning college English courses, and analyzes learners’ learning habits, learning progress and learning effect. Finally, according to the learning big data, this paper customized a reasonable personalized learning platform and improved the online teaching personalized service system.
Named Entity Recognition with Gating Mechanism and Parallel BiLSTM
Authors: Yi Yenan , Bian Yijie
Published: July 2021

In this paper, we propose a novel neural network for named entity recognition, which is improved in two aspects. On the one hand, our model uses a parallel BiLSTM structure to generate character-level word representations. By inputting character sequences of words into several independent and parallel BiLSTMs, we can obtain word representations from different representation subspaces, because the parameters of these BiLSTMs are randomly initialized. This method can enhance the expression abilities of character-level word representations. On the other hand, we use a two-layer BiLSTM with gating mechanism to model sentences. Since the features extracted by each layer in a multi-layer LSTM from texts contain different types of information, we use the gating mechanism to assign appropriate weights to the outputs of each layer, and take the weighted sum of these outputs as the final output for named entity recognition. Our model only changes the structure, does not need any feature engineering or external knowledge source, which is a complete end-to-end NER model. We used the CoNLL-2003 English and German datasets to evaluate our model and got better results compared with baseline models.
Optimal Design of Electrical Capacitance Tomography Sensor and Improved ART Image Reconstruction Algorithm Based On the Internet of Things
Authors: Chen Feng , Chen Deyun , Wang Lili , Botao Yang
Published: July 2021

For the problems of low sensitivity, weak signal of high and low frequency and low signal-to-noise ratio in ECT, the mathematical model of the sensor is established. From the aspects of electrostatic field distribution and soft field effect, the influence of the structural parameters of the sensor on the sensor performance is analyzed. According to the influence of the components of the sensor on the sensitivity, the principle of optimal design is put forward. Based on the optimized Landweber image reconstruction algorithm, an ART image reconstruction algorithm with iterative correction is proposed, and the mathematical model of the algorithm is designed. According to constructing the target functional regularization term in the negative problems of electrical capacitance tomography, the iterative process of the modified art algorithm is deduced, and with adaptive step size, the convergence is speeded and accuracy of image reconstruction is improved. The experimental results show that the semi-convergence in the improved algorithm is obviously weakened, and the reconstructed image quality is better than that of the traditional art algorithm.
A physically stabilized and locking-free formulation of the (SHB8PS) solid-shell element
Authors: Abed-Meraim Farid , Combescure Alain
Published: July 2021

In this work, the formulation of the SHB8PS finite element is reviewed in order to eliminate some persistent membrane and shear locking phenomena. This is a solid-shell element based on a purely three-dimensional formulation. In fact, the element has eight nodes as well as five integration points, all distributed along the “thickness” direction. Consequently, it can be used for the modeling of thin structures, while providing an accurate description of the various through-thickness phenomena. The reduced integration has been used in order to prevent some locking phenomena and to increase computational efficiency. The spurious zero-energy modes due to the reduced integration are efficiently stabilized, whereas the strain components corresponding to locking modes are eliminated with a projection technique following the Enhanced Assumed Strain (EAS) method.
Application of the penalty coupling method for the analysis of blood vessels
Authors: Pericevic Ian Owens , Moatamedi Moji
Published: July 2021

Due to the significant health and economic impact of blood vessel diseases on modern society, its analysis is becoming of increasing importance for the medical sciences. The complexity of the vascular system, its dynamics and material characteristics all make it an ideal candidate for analysis through fluid structure interaction (FSI) simulations. FSI is a relatively new approach in numerical analysis and enables the multi-physical analysis of problems, yielding a higher accuracy of results than could be possible when using a single physics code to analyse the same category of problems. This paper introduces the concepts behind the Arbitrary Lagrangian Eulerian (ALE) formulation using the penalty coupling method. It moves on to present a validation case and compares it to available simulation results from the literature using a different FSI method. Results were found to correspond well to the comparison case as well as basic theory.
Error estimates for the unilateral buckling critical load of a thin plate
Authors: Ayadi Mekki
Published: July 2021

The paper deals with error estimates for the unilateral buckling critical load of a thin plate in presence of an obstacle. First, using the Kirchhoff-Love’s plate model, an abstract error estimate is given up. Its drawback is that it contains a hard term to evaluate. Then, by using the Mindlin’s plate model together with a finite elements scheme of degree one, an error estimate, depending on the mesh size h, is established. The last part of the paper is devoted to some numerical results in order to validate the error estimate formula.
Couplage et adaptation de maillage anisotrope pour des simulations de flux d’air dans des géométries complexes
Authors: Dobrzynski Cécile , Frey Pascal , Pironneau Olivier
Published: July 2021

The numerical simulation of air flow in a building or a house is certainly a very challenging field of engineering applications. The objectives differ from one application to the other, ranging from the optimization of air conditioning systems in buildings to the study of the propagation of harmful products via the air conditioning system. In this paper, we address the problem of coupling the Navier-Stokes equations for incompressible fluids and a temperature equation. To solve this problem in 3d, we use an anisotropic mesh adaptation strategy. The meshes are generated by a local remeshing techniques based on an anisotropic version of Delaunay kernel. The method is fairly general and applies to other cases as well. We illustrate this problem with an example showing the heating of the last floor of a furnished house.
Méthodes numériques de propagation de fissures appliquées au découpage des métaux
Authors: Lemiale Vincent , Chambert Jérôme , Touache Abdelhamid , Picart Philippe
Published: July 2021

The purpose of this paper is to propose an efficient numerical tool to simulate the blanking process and predict the geometric and mechanical characteristics of the blanked component. Two different strategies are proposed to simulate the crack propagation: a finite element elimination method and a discrete cracking approach. First, these methods are evaluated on the set-up test of an asymmetrical plate submitted to traction. Second, the ability of these methods to predict a realistic cut edge profile is analyzed within the framework of blanking. The load - penetration punch curves obtained by both fracture propagation methods are compared to the experimental one.
Approche couplée éléments discrets/finis pour la simulation d’un impact sur ouvrage
Authors: Frangin Emmanuel , Marin Philippe , Daudeville Laurent
Published: July 2021

The paper deals with combined finite/discrete element method to study structures under severe dynamic loading, like impact. The discrete element method take naturally into account the non linear phenomena, it is used in the vicinity of the impacted zone. The finite element method is used to reduce the time of computation in order to carry out large structure analyses. The aim of the paper is to discuss the way to reduce non physical wave reflections; it presents an application on a rock impact on a concrete slab.
Theory and practice of optimal shape design
Authors: Mohammadi Bijan , Pironneau Olivier
Published: July 2021

This paper is a short survey of some recent developments in Optimal Shape Design (OSD) for fluids. Existence, sensitivity, compatibility of discretizations as well as efficient algorithmic implementations with low complexity are critical. In this paper we will discuss some of these issues with application to shape optimization for aerodynamic noise reduction.
Multilevel strategies for parametric shape optimization in aerodynamics
Authors: El Majd Badr Abou , Désidéri Jean-Antoine , Duvigneau Régis
Published: July 2021

The essential numerical features of multilevel strategies developed for parametric shape optimization are reviewed. These methods employ nested parameterization supports of either shape, or shape deformation, and the classical process of degree elevation resulting in exact geometrical data transfer from coarse to fine representations. The algorithms mimick classical multigrid strategies and are found very effective in terms of convergence acceleration. In particular, for a drag reduction problem involving a three-dimensional Eulerian transonic flow simulated by an unstructured-grid finite-volume method, the complete algorithm is found to be noticeably superior to the natural algorithm simply based on progressive degree elevation.
Etude de l’influence des défauts de petite taille sur le comportement à rupture avec le modèle de Dugdale régularisé
Authors: Ferdjani Hichème , Khelifi Med Zaim , Marigo Jean-Jacques
Published: July 2021

The goal of this work is to prove that, within the framework of Fracture Mechanics with the regularized Dugdale’s model of cohesive forces, the defects the size of which are small compared to the material characteristic length are practically without influence on the limit loads of structures. For that, we treat two examples : the case of a precracked plate, then the case of a plate with a circular hole. The calculations are made with the finite element method.
Utilisation du quadrangle « discrete shear » pour la génération des surfaces d’influence des efforts de plaque
Authors: Lévêque Philippe , Bacchus Florent
Published: July 2021

Concept of influence surface is the appropriate tool to determine the extreme structural response values of structures under the effect of moving loads. The action of road traffic moving on bridge deck is computed this way. Influence surface generation method is based on Maxwell-Betti’s theorem of reciprocity. This paper presents the use of the « discrete shear » formulation of a thick plate quadrangle finite element to generate the influence surfaces of internal forces in a slab bridge using the Code_Aster free software.
On the frontier of the simulation world
Authors: Chinesta Francisco , Ammar Amine
Published: July 2021

In the last years, we have assisted to an impressive progression in the numerical modeling capabilities as a result of the progression in computer science but also in the numerical analysis. Thus, new scales have been explored, allowing modeling of richer and finer physical models. In this work we focus on some models encountered in the microscopic description of the physics, all of them with a common particularity: they involve an impressive number of degrees of freedom or are defined in highly multidimensional spaces.
Fracture of piezoelectric materials with the X-FEM
Authors: Béchet Eric , Scherzer Matthias , Kuna Meinhard
Published: July 2021

We present an application of X-FEM to the fracture analysis of piezoelectric materials. These materials are increasingly used in actuators and sensors. Under in service loading, phenomena of crack initiation and propagation may occur due to high electromechanical field concentrations. In the past few years, the extended finite element method (X-FEM) has been applied mostly to model cracks in structural materials. The present paper focuses on the definition of new enrichment functions suitable for cracks in piezolectric structures. The approach is based on specific asymptotic crack tip solutions, derived for piezoelectric materials.
A quasi-symmetric formulation for contact between deformable bodies
Authors: Fourment Lionel
Published: July 2021

In the frame of contact issues between 3D deformable bodies with non-matching finite element discretizations of possibly very different mesh sizes, a quasi-symmetric formulation is proposed to obtain satisfactory results whichever body is selected as master or slave. This approach is not based on usual mortar elements in order to avoid the creation of an additional integration surface. It draws its inspiration from a symmetric treatment of the contact conditions, where the formulation is made compatible by replacing the Lagrange multiplier of the master body by the projection of the slave one. Numerical results are obtained within the FORGE3® finite element software. Numerous 3D test cases numerically show that this approach actually solves the main issues of contact between deformable bodies, in a rather simple way.
Key Concepts in Advertising: Sponsorship
Authors: Meyers Cynthia B.
Published: July 2021

Abstract: Keywords in Advertising articles provide short lectures on an important concept to help understand advertising's place in society, culture, history, and the economy. This article focuses on sponsorship: the act of supporting an event, activity, person, or organization financially or through providing products or services in return for an opportunity to advertise. It's not a new strategy: advertisers have long used events and programs to get consumers' attention. The first video provides an overview of how advertisers used sponsorship in early broadcasting, when barking sled dogs and jokes about Jell-O were integrated into sponsored radio shows. The second video includes examples of early television sponsorship, including singing gas station attendants for Texaco and future President Ronald Reagan promoting electricity for General Electric. The third video is an overview of how advertisers are using sponsorship today and includes clips from Hawaii 5-0 and Cherries Wild . A recommended reading list provides other sources to learn more about sponsorship and its associated topics.
Clinical assessment of W-band spectroscopy for non-invasive detection and monitoring of sustained hyperglycemia
Authors: Moreno-Oyervides Aldo , Aguilera-Morillo M. Carmen , de la Cruz Fernández María José , Pascual Edurne Lecumberri , Jiménez Lucía Llanos , Krozer Viktor , Acedo Pablo
Published: July 2021

HbA1c is the gold standard test for monitoring medium/long term glycemia conditions in diabetes care, which is a critical factor in reducing the risk of chronic diabetes complications. Current technologies for measuring HbA1c concentration are invasive and adequate assays are still limited to laboratory-based methods that are not widely available worldwide. The development of a non-invasive diagnostic tool for HbA1c concentration can lead to the decrease of the rate of undiagnosed cases and facilitate early detection in diabetes care. We present a preliminary validation diagnostic study of W-band spectroscopy for detection and monitoring of sustained hyperglycemia, using the HbA1c concentration as reference. A group of 20 patients with type 1 diabetes mellitus and 10 healthy subjects were non-invasively assessed at three different visits over a period of 7 months by a millimeter-wave spectrometer (transmission mode) operating across the full W-band. The relationship between the W-band spectral profile and the HbA1c concentration is studied using longitudinal and non-longitudinal functional data analysis methods. A potential blind discrimination between patients with or without diabetes is obtained, and more importantly, an excellent relation (R-squared = 0.97) between the non-invasive assessment and the HbA1c measure is achieved. Such results support that W-band spectroscopy has great potential for developing a non-invasive diagnostic tool for in-vivo HbA1c concentration monitoring in humans.
Introduction to the ECOC 2020 Special Issue
Authors: Van Daele Peter , Koonen Ton , Bauwelinck Johan , Raz Oded
Published: July 2021

This special issue includes extensions of invited and top-scored optical networking papers that were presented at the European Conference on Optical Communication (ECOC) 2020, held virtually, December 6–10, 2020.
Evaluation of the colour quality of display primary: Part I. Chromaticity based methods
Authors: Xu Lihao , Luo Ming Ronnier
Published: July 2021

It is a challenge to determine the RGB primaries when designing a display. A big issue is to estimate the colorimetric performance of the display. In this paper, a systematic method was proposed to determine the best RGB primaries for a display. Nine testing metrics were implemented and they were divided into two groups (the gamut metrics and the colour related metrics). They were adopted to evaluate the performance of 52 displays having different RGB primary combinations. The results verified the proposed method. Some of the testing metrics gave similar results and it should be sufficient to choose some of them to reveal the overall performance of a display.
Compact hybrid plasmonic slot waveguide sensor with a giant enhancement factor for surface-enhanced Raman scattering application
Authors: Wang Suoming , Zhu Yanying , Luo Sijie , Zhu Erkuang , Chen Shuqing
Published: July 2021

In this paper, a surface-enhanced Raman scattering (SERS) sensor with a giant field enhancement factor based on the coupling of surface plasmon polaritons (SPPs) is designed and studied theoretically. The proposed sensor adopts a metal-dielectric layered hybrid slot waveguide structure, combining thin metal (gold) layers and silicon nitride strip waveguides. Unlike other similar sensors, the silicon nitride waveguide structure does not serve as an excitation signal channel, conventionally loaded with the guided modes, but as an auxiliary layer, making it easier to concentrate the light field in the slot. Therefore, the sensor has a higher enhancement factor compared to the pure metal or dielectric slot structure. The results exhibit that we can obtain a maximum enhancement factor exceeding 10^6 under the compact configuration of 510 × 300 × 225nm^3 at the wavelength of 785 nm. By analyzing the dependence of the sensor performance on the structural parameters, we show that the structure of such sensor can directly be applied to SERS spectroscopic analysis as well as integrated with micro-and nano-photonic platform to perform on-chip detection system.
Label-free detection of virus-like particles employing rotationally symmetric nanowire array based whispering gallery and quasi-whispering gallery resonant modes onto a silicon platform
Authors: Hassan Mohammad Muntasir , Baten Md Zunaid
Published: July 2021

In spite of tremendous advancements in modern diagnostics, there is a dire need for reliable, label-free detection of highly contagious pathogens like viruses. In view of the limitations of existing diagnostic techniques, the present theoretical study proposes a novel scheme of detecting virus-like particles employing whispering gallery and quasi-whispering gallery resonant modes of a composite optical system. Whereas whispering gallery mode (WGM) resonators are conventionally realized using micro-disk, -ring, -toroid or spherical structures, the present study utilizes a rotationally symmetric array of silicon nanowires which offers higher sensitivity compared to the conventional WGM resonator while detecting virus-like particles. Notwithstanding the relatively low quality factor of the system, the underlying multiple-scattering mediated photon entrapment, coupled with peripheral total-internal reflection, results in high fidelity of the system against low signal-to-noise ratio. Finite difference time domain based numerical analysis has been performed to correlate resonant modes of the array with spatial location of the virus. The correlation has been subsequently utilized for statistical analysis of simulated test cases. Assuming detection to be limited by resolution of the measurement system, results of the analysis suggest that for only about 5% of the simulate test cases the resonant wavelength shift lies within the minimum detection range of 0.001-0.01 nm. For a single virus of 160 nm diameter, more than 8 nm shift of the resonant mode and nearly 100% change of quality factor are attained with the proposed nanowire array based photonic structure.
Development of a two-degree-of-freedom vibration generator for fabricating optical microstructure arrays
Authors: Du Hanheng , Yip Waisze , Zhu Zhiwei , To Sandy
Published: July 2021

Optical microstructure arrays on metallic surfaces are drawing ever-increasing attention due to the increasing requirements in optical systems. Although vibration generators are developed for generating optical microarrays with the ultra-precision diamond cutting process, the systematic research works on its mechanical design, working performance simulation, and numerical simulation of microstructure arrays has received less attention. In this study, a novel two-degree-of-freedom vibration generator (2DOF-VG) is designed based on the triangular amplification mechanism. To precisely simulate the working performance of this designed 2DOF-VG, the detailed multi-physics finite element method is proposed. Considering the three-dimensional geometric shape of the cutting tool, the cutting motion trajectory, and the elastic recovery of the workpiece material, the numerical simulation algorithm of the microstructure arrays generation is then established and used to precisely predict the surface topography of microstructure arrays. Finally, two types of unique microstructure arrays are fabricated, which demonstrates the feasibility and flexibility of the 2DOF-VG.
Multi-controlled broadband terahertz absorber engineered with VO2-integrated borophene metamaterials
Authors: Liu Meng , Cheng Weijuan , Zhang Yanliang , Zhang Huiyun , Zhang Yuping , Li Dehua
Published: July 2021

We demonstrated a dynamically controlled broadband terahertz (THz) metamaterials absorber, which composed of continuous vanadium dioxide (VO2) film, a silicon dioxide (SiO2) layer, and a structured borophene layer. When VO2 is in its metallic state and the armchair direction of borophene along x axis, the proposed absorber realizes an absorptivity peak value of 100% at 7.2 THz for y polarized normal incidence, and an absorptivity peak value of 79% at 8.9 THz for x polarized normal incidence. It is the anisotropic property of borophene that results in the absorptivity difference for x and y polarization in the whole frequency range. Simulated electric field distribution and surface current oscillation has been extracted to explain the physical mechanism of THz wave absorption. Through modifying the geometric parameters of metamaterials microstructure, the broadband absorption performance can be tailored passively. Additionally, the proposed metamaterials absorber has been actively controlled by manipulating the carrier density of borophene and the conductivity of VO2, respectively. The absorptivity can be switched from 45% to 100% at 7.2 THz by changing the carrier density of borophene, and from 22% to 100% at 7.2 THz by changing the conductivity of VO2. Moreover, the proposed absorber exhibits an excellent operation tolerance for oblique TE and TE polarized incidence from 0° to 60°. This work provides a novel approach to design dynamically controlled broadband THz absorbers, which reveals promising applications in the devices of optoelectronic switches, cloakings, filters, and sensors, etc.
Use of zinc to increase fluorescence in an in vitro biofilm model as a tool for caries diagnosis
Authors: Wichachang Kittituspong , Locharoenrat Kitsakorn
Published: July 2021

Artificial sound enamel and caries enamel lesions were prepared. The sound enamel did not emit fluorescence in the visible spectrum. The spectrum of Zn(II)-protoporphyrin-9 biofilm from caries enamel lesions showed the fluorescence emitted by Zn(II)-protoporphyrin-9, with two main peaks at 630 and 690 nm. The luminescence properties of protoporphyrin-9 change depended on the amount of Zn(II). The increase in fluorescence intensity as Zn(II)-protoporphyrin-9 penetrated deeper to 1.75 mm was appropriate for the diagnosis of caries enamel lesions. Fluorescence intensity was maximum when Zn(II) reached 0.0256 µM and significantly produced a high contrast of fluorescence image together with high fluorescence quantum efficiency and photostability.
Association between type 2 diabetes and osteoporosis risk: A representative cohort study in Taiwan
Authors: Lin Hsin-Hui , Hsu Hsin-Yin , Tsai Ming-Chieh , Hsu Le-Yin , Chien Kuo-Liong , Yeh Tzu-Lin
Published: July 2021

Although previous studies have investigated the relationship between fracture risk and type 2 diabetes (T2D), cohort studies that estimate composite osteoporosis risk are lacking. This retrospective cohort study sought to determine the risk of osteoporosis in Taiwanese patients with T2D. Patients diagnosed with T2D between 2002 and 2015 identified through the 2002 Taiwan Survey of Hypertension, Hyperglycemia, and Hyperlipidemia were included. A total of 1690 men and 1641 women aged ≥40 years linked to the National Health Insurance Research Database (NHIRD) were followed up to the end of 2015 to identify the incidences of osteoporosis through ICD9-CM codes for osteoporosis or osteoporotic fractures or usage of anti-osteoporotic agents according to Anatomical Therapeutic Chemical codes determined from NHIRD. The person year approach and Kaplan–Meier analysis were then used to estimate the incidences and cumulative event rates, whereas the Cox proportional hazard model was used to calculate adjusted hazard ratios (HR) for osteoporosis events. A total of 792 new osteoporosis events were documented over a median follow-up duration of 13.6 years. Participants with T2D had higher osteoporosis risk [adjusted HR: 1.37, 95% confidence interval (CI): 1.11–1.69] compared with those without T2D. Subgroup analyses revealed that age had a marginally significant effect, indicating that T2D had a more pronounced effect on osteoporosis risk in younger population (<65 years old). No difference was found between patients stratified according to sex. In conclusion, T2D was significantly associated with increased osteoporosis risk, especially in younger participants.
Prediction of 28-day mortality in critically ill patients with COVID-19: Development and internal validation of a clinical prediction model
Authors: Leoni Matteo Luigi Giuseppe , Lombardelli Luisa , Colombi Davide , Bignami Elena Giovanna , Pergolotti Benedetta , Repetti Francesca , Villani Matteo , Bellini Valentina , Rossi Tommaso , Halasz Geza , Caprioli Serena , Micheli Fabrizio , Nolli Massimo
Published: July 2021

Background

COVID-19 pandemic has rapidly required a high demand of hospitalization and an increased number of intensive care units (ICUs) admission. Therefore, it became mandatory to develop prognostic models to evaluate critical COVID-19 patients.

Materials and methods

We retrospectively evaluate a cohort of consecutive COVID-19 critically ill patients admitted to ICU with a confirmed diagnosis of SARS-CoV-2 pneumonia. A multivariable Cox regression model including demographic, clinical and laboratory findings was developed to assess the predictive value of these variables. Internal validation was performed using the bootstrap resampling technique. The model’s discriminatory ability was assessed with Harrell’s C-statistic and the goodness-of-fit was evaluated with calibration plot.

Results

242 patients were included [median age, 64 years (56–71 IQR), 196 (81%) males]. Hypertension was the most common comorbidity (46.7%), followed by diabetes (15.3%) and heart disease (14.5%). Eighty-five patients (35.1%) died within 28 days after ICU admission and the median time from ICU admission to death was 11 days (IQR 6–18). In multivariable model after internal validation, age, obesity, procaltitonin, SOFA score and PaO2/FiO2 resulted as independent predictors of 28-day mortality. The C-statistic of the model showed a very good discriminatory capacity (0.82).

Conclusions

We present the results of a multivariable prediction model for mortality of critically ill COVID-19 patients admitted to ICU. After adjustment for other factors, age, obesity, procalcitonin, SOFA and PaO2/FiO2 were independently associated with 28-day mortality in critically ill COVID-19 patients. The calibration plot revealed good agreements between the observed and expected probability of death.
The epidemiology of autoimmune bullous diseases in Sudan between 2000 and 2016
Authors: Siddig Omayma , Mustafa Mayson B. , Kordofani Yousif , Gibson John , Suleiman Ahmed M.
Published: July 2021

Objectives

Autoimmune bullous diseases vary in their clinico-epidemiological features and burden across populations. Data about these diseases was lacking in Sudan. We aimed to describe the epidemiological profile and to estimate the burden of autoimmune bullous diseases in Sudan.

Methods

This was a retrospective cross-sectional study conducted at Khartoum Dermatological and Venereal Diseases Teaching Hospital. We used routinely collected health care data, and included all patients with an autoimmune bullous disease who presented to the hospital between 2001 and 2016.

Results

Out of the 4736 patients who were admitted to the hospital during the study period, 923 (19.5%) had an autoimmune bullous disease. The average rate of patients at the hospital was 57.7 per year representing 1.3 per 100,000 population per year. After exclusion of patients where the final diagnosis was missing, 585 were included in the further analysis. Pemphigus vulgaris was the most common disease (50.9%), followed by bullous pemphigoid (28.2%), linear IgA disease/chronic bullous disease of childhood (8.4%), and pemphigus foliaceous (8.2%). Pemphigoid gestationis and IgA pemphigus constituted 1.4% and 1.2% of the cohort, respectively. Paraneoplastic pemphigus, mucous membrane pemphigoid, lichen planus pemphigoidis, bullous systemic lupus erythematosus, and dermatitis herpetiformis were rare. None of the patients had epidermolysis bullosa acquisita.

Conclusions

The clinico-epidemiological characteristics vary among the types of autoimmune bullous diseases. Females were more predominant in most of them. Sudanese patients tended in general to present at a younger age than other populations. The pool of Sudanese patients with autoimmune bullous diseases is large which requires investigation for the local risk factors and presents a field for future trials.
Availability of preoperative neutrophil-lymphocyte ratio to predict postoperative delirium after head and neck free-flap reconstruction: A retrospective study
Authors: Kinoshita Hirotaka , Saito Junichi , Takekawa Daiki , Ohyama Tasuku , Kushikata Tetsuya , Hirota Kazuyoshi
Published: July 2021

Postoperative delirium (POD) is a well-recognized postoperative complication and is associated with increased morbidity and mortality. We investigated whether the preoperative neutrophil-lymphocyte ratio (NLR) could be an effective predictor of POD after head and neck free-flap reconstruction. This was a single-center, retrospective, observational study. We analyzed the perioperative data of patients who had undergone elective head and neck free-flap reconstruction surgery. POD was assessed with the Intensive Care Delirium Screening Checklist (ICDSC) during admission to our intensive care unit (ICU). POD was defined as an ICDSC score ≥4. Risk factors for POD were evaluated by univariate and multivariate logistic regression analysis. We included 97 patients. The incidence of POD was 20.6% (20/97). Significantly longer ICU stays were observed in the patients with POD compared to those without POD (median [interquartile range]: 5 [4–6] vs. 4 [4–5], p = 0.031). Higher preoperative NLR values (3 <NLR ≤4 and 4 <NLR) were significantly associated with higher ICDSC scores compared to NLR ≤1 (4 [2–4] vs. 1 [1–1], p = 0.027 and 4 [1–4] vs. 1 [1–1], p = 0.038, respectively). The multivariable logistic regression analysis revealed that only a preoperative NLR >3.0 (adjusted Odds Ratio: 23.6, 95% Confidence Interval: 6.6–85.1; p<0.001) was independently associated with POD. The multivariate area under the receiver operator curve was significantly greater for the E-PRE-DELIRIC model with NLR compared to the E-PRE-DELIRIC model (0.87 vs. 0.60; p<0.001). The preoperative NLR may be a good predictor of POD in patients undergoing head and neck free-flap reconstruction.
Videoclip musical y nuevas tendencias en formatos musicovisuales [Editorial]
Authors: Sedeño-Valdellós Ana , Guarinos-Galan Virginia , Pérez-Rufi José Patricio
Published: July 2021

Quizás sea el videoclip musical, producción audiovisual de corta duración, grabada por expreso deseo de acompañar un track musical preexisten para animar las ventas musicales, el formato más poroso a las transformaciones del audiovisual digital, las redes sociales y las prácticas interactivas que permiten las tecnologías de la comunicación en la actualidad. Frente a otros medios o formatos que se han visto en la necesidad de redefinir su naturaleza por una pura cuestión de supervivencia, el video musical ha renacido al punto de convertirse en un referente fundamental de producción preferida por la audiencia o por los usuarios, al tiempo que las industrias culturales han entendido su idoneidad como vehículo de transmisión de variados mensajes o como medio adecuado a la experimentación de tecnologías y lenguajes. A pesar de esta centralidad cultural y de que cada vez es más frecuente encontrar investigaciones que lo tengan como objeto de estudio, es uno de los formatos más desconocidos y escasamente enfrentados desde la teoría y el análisis audiovisual. A ello se une que su extraordinaria variedad como formato impide establecer una única metodología de análisis o encuadre epistemológico. Junto a esto, dos son los elementos de contexto que ayudarían a encuadrar al videoclip en su etapa post-YouTube: su creciente especialización por géneros musicales y su naturaleza de formato publicitario en transformación constante. Por todo ello, y en este momento de crisis de la industria discográfica, audiovisual y mediática, donde los fenómenos de transmediación y de hibridación vuelven complicada una diferenciación en categorías estanco, asistimos a una gran complejidad del formato, como nos parece necesario destacar y es prueba este monográfico.
Calidad informativa en la era de la digitalización: Fundamentos profesionales vs. infopolución
Authors: Osuna-Acedo Sara
Published: July 2021

El libro Calidad informativa en la era de la digitalización: Fundamentos profesionales vs. Infopolución presenta el trabajo pormenorizado de reconocidos investigadores que presentan sus avances en el área de la comunicación. El libro, estructurado en un prólogo y 12 capítulos, está dirigido a los docente, investigadores y profesionales del periodismo y de la comunicación digital. Los autores se centran en la calidad de la información en la era actual, caracterizada por la infopolución, la postverdad y la manipulación informativa. En todos los capítulos se tratan cada uno de los temas que preocupan acerca del proceso de comunicación en los tiempos actuales, sin perder la perspectiva del humanismo digital. Por ello, este libro está escrito teniendo como eje central a una ciudadanía digital, participativa, intercreativa y protagonista de sus actos comunicativos en los entornos que proporcionan las Tecnologías de la Relación, la Información y la Comunicación (TRIC).
Sobre la investigación en Comunicación en España
Authors: Rodríguez-Ferrándiz Raúl
Published: July 2021

Reseña del libro Investigar en la era neoliberal. Visiones críticas sobre la investigación en comunicación en España.
Forma y fondo, nuevas perspectivas de la publicidad
Authors: Marta-Lazo Carmen
Published: July 2021

Este año Revista Mediterránea de Comunicación cumple su décimo aniversario. Ha sido una década en constante crecimiento que queremos celebrar con quienes habéis depositado la confianza en nuestro journal, tanto los autores, como los investigadores y lectores que habéis hecho que se convierta en una revista fuente de la que beber. Las posiciones en los diferentes ranking así lo atestiguan. Como estamos de celebración, nada mejor que dar una buena noticia antes de pasar a brindar por los éxitos conseguidos y por los que, de la mano de todas vosotras y vosotros, estén por llegar. Paso a anunciar este gran titular: en la Base de Dialnet Métricas nos hemos posicionado en quinto lugar del cuartil 1, tras las prestigiosas revistas Comunicar, El profesional de la información, Revista Latina de Comunicación Social y Comunicación y Sociedad. Hemos alcanzado un destacado índice de impacto de 0,688, con 128 artículos y un total de 88 citas. A ello se suma nuestro sello de calidad FECYT, el estar en Emerging Source Citation Index (ESCI) de Clarivate donde el estudio de Revista Comunicar (2018) le otorga la 6ª posición en España (42/102 en el mundo, Q2, IF: 0,241, percentil 57); 3ª en España en el ranking REDIB (CSIC); 8ª de 41 en Google Scholar Metric en el campo de Comunicación (2018); y la situación en cuarto puesto de las revistas latinoamericanas en comunicación, en el índice de la Red Iberoamericana de innovación y Conocimiento Científico, promovido por Clarivate y CSIC, entre otros logros.
Apps móviles y empoderamiento mediático en entornos digitales y ubicuos
Authors: Villalonga-Gómez Cristina , Hergueta-Covacho Elisa
Published: July 2021

La sociedad del siglo XXI se caracteriza por estar interconectada, en gran medida gracias al uso de dispositivos que tienen una presencia fundamental en nuestras vidas y que nos acompañan a todas partes y en todos los contextos, tanto sociales, como laborales y educativos. La tecnología se vuelve omnipresente. Objetos cotidianos se convierten en inteligentes. Se conectan entre ellos. Aplicaciones, dispositivos, redes, infraestructuras que convergen y producen una ingente cantidad de contenido e información variada, rápida y de gran alcance que nos plantea, tanto a las organizaciones como a los usuarios, nuevos retos tecnológicos, comunicativos y socioculturales para hacer frente a esta distribución instantánea digitalizada.
[Editorial] Profundo agradecimiento
Authors: Tur-Viñes Victoria
Published: July 2021

Una vez sobrepasados los 10 años de publicación ininterrumpida, es hora de agradecer la contribución de todos los colaboradores que han hecho posible este reto. Revisores, autores, miembros del comité científico, todos y todas habéis impulsado con vuestro aliento las velas de este barco que navega de forma decidida en aguas internacionales.
Las narrativas transmedia en el aprendizaje de lenguas extranjeras
Authors: Andrade-Velásquez Marjorie-Roxana , Fonseca-Mora María-Carmen
Published: July 2021

La educación transmedia ha irrumpido en el campo educativo en los últimos años generando nuevas formas de aprendizaje activo centrado en los estudiantes. Sin embargo, aún se desconoce su efectividad y cómo afecta al aprendizaje de lenguas extranjeras. En este artículo se revisa de manera sistemática estudios de la aplicación de Transmedia Storytelling o Narrativas Transmedia para detallar los beneficios del resultado de su aplicación y los principales logros alcanzados por los estudiantes en el aprendizaje de lenguas extranjeras. Esta síntesis cualitativa, que surge de la revisión de estudios publicados al respecto desde el año 2010 al 2020, permite describir el estado actual de la cuestión y recomendar esta innovadora técnica metodológica en el contexto educativo para el desarrollo de las competencias lingüísticas de una lengua extranjera.
Política y redes sociales. Perfiles de Pedro Sánchez y Pablo Iglesias en Instagram antes y después de ser cargos públicos (2019-2020)
Authors: Gil-Torres Alicia , Tapia-Cuesta Sofía , San-José-de-la-Rosa Cristina
Published: July 2021

En la comunicación política priman plataformas que permiten a los actores políticos desarrollar estrategias comunicativas e interactuar con la sociedad Este artículo se embarca en una casi desconocida investigación que aúna la actualidad política española con el auge de Instagram, la red social que crece exponencialmente y más demandada por los jóvenes (WeAreSocial, 2020). Un estudio cuantitativo y cualitativo de casi 1.000 publicaciones de las cuentas del presidente Pedro Sánchez y del vicepresidente Pablo Iglesias comprendidas entre el 5 de abril de 2019 y 2020 analiza cómo son sus estrategias comunicativas (imagen, texto, connotación e interactividad) e indaga si la comunicación en sus cuentas de Instagram ha cambiado después de que Pedro Sánchez y Pablo Iglesias tomaran posesión de sus cargos en el primer Gobierno de coalición de la historia democrática de España. Los resultados muestran un cambio de estrategia comunicativa en ambos líderes cuando alcanzan el Ejecutivo y, aunque publican contenido referido al Gobierno, no logran proyectar una imagen de unidad política.
Evolución de la inversión publicitaria durante la década de crisis económica (2007-2018). El caso del sector del automóvil y su adaptación a Internet
Authors: Bonales-Daimiel Gema , Mañas-Viniegra Luis
Published: July 2021

La crisis económica y la irrupción de la tecnología -liderada por el medio Internet- han provocado una auténtica transformación del sector de la publicidad y del mercado del automóvil. En los últimos años, las industrias, y más concretamente la automovilística, se han dado cuenta del poder que ejerce Internet -por tratarse de un medio interactivo-, dotándole de gran protagonismo en la estrategia de comunicación corporativa al permitirles contactar con millones de potenciales clientes que cada vez pasan más tiempo conectados (Armstrong, 2001). El objetivo de la presente investigación es examinar a partir de un análisis de contenido la evolución de la inversión en el periodo analizado y los cambios en la publicidad, si los hubiera habido. Los resultados sugieren que la tecnología ha evolucionado de una manera tan notoria que ha condicionado la publicidad. Concretamente, la cifra de inversión total de la automoción en publicidad ha descendido un 61% en el periodo que va desde el año 2007 al 2018, mientras que la publicidad en Internet ha crecido un 83% en el mismo ciclo (Infoadex, 2019).
Claves para repensar los medios y el mundo que habitamos [Reseña]
Authors: Espinar Lara-María
Published: July 2021

Distopía, “representación ficticia de una sociedad futura de características negativas causantes de la alineación humana” (Real Academia de la Lengua Española). Esta es la palabra que Manuel Chaparro, con matemática precisión, escoge para el título de su obra: “Claves para repensar los medios y el mundo que habitamos. La distopía del desarrollo”. Para el autor desarrollo es mucho más que un término, se trata de todo un sistema complejo cuyo carácter distópico va desenmascarando a través de las páginas de este libro, que nos ofrece una perspectiva de análisis de la realidad y la evolución que hemos tenido como civilización desde el ámbito de la comunicación. Un libro que nos habla de cómo la información y la comunicación han construido, difundido e implantado los imaginarios del Modelo de Desarrollo.
Violencia simbólica e inequidad de género en la publicidad radiofónica en México
Authors: Medina-Ávila Virginia , Mecalco-López Rosa-Azucena
Published: July 2021

Pese a los adelantos en materia de equidad de género realizados en México, dentro de la radio existe aún un rezago importante que impide contrarrestar la violencia simbólica ejercida en contra de las mujeres, la cual se refleja, sobre todo, en la publicidad que se presenta en las estaciones radiofónicas del Zona Metropolitana del Valle de México. En este artículo se realiza un extenso análisis de las narrativas de la publicidad radiofónica en México desde 1991 hasta 2018 para conocer cuál es el papel de las voces femeninas y las estructuras que perpetúan la violencia de género. Pero también para entender cómo se crean esas estructuras y cuáles son las consecuencias de su reiteración. El análisis se realizó en dos tiempos, por medio de dos matrices distintas: elementos sonoros generales y con perspectiva de género. Con un universo de 313 spots, se encontró que la violencia simbólica sigue vigente. Asimismo, si bien en México se analiza la incursión de la mujer en los procesos de la radio o la publicidad dentro de sus espacios, no se realiza un análisis del impacto de ésta en el avance de la equidad, motivo por el cual la presente investigación resulta necesaria.