Changes in classroom assessment practices during emergency remote teaching due to COVID-19.

This study explores the effects of the shift to emergency remote teaching on assessment practices due to COVID-19 lockdown. A total of 936 Spanish teachers from all educational levels ranging from early childhood to university participated in this nationwide survey. Four aspects were explored: (1) changes in the use of assessment instruments (e.g. exams); (2) changes in assessment criteria, standards and grading; (3) changes in the delivery of feedback and use of rubrics; and (4) changes in students’ involvement in assessment (i.e. self- and peer assessment). In general, results are mixed, with some areas undergoing certain changes with the aim of adapting to the new situation (e.g. primary education teachers lowering their grading standards), whereas many other assessment practices have remained similar, especially among higher education teachers. Unfortunately, some of the assessment practices have worsened, such as students’ involvement in assessment which has decreased.pre-print764 K

Parallel Computing in Water Network Analysis and Leakage Minimization

[EN] In this paper a parallel computing based software demonstrator for the simulation and leakage minimization of water networks is presented. This demonstrator, based on the EPANET package, tackles three different types of problems making use of parallel computing. First, the solution of the hydraulic problem is treated by means of the gradient method. The key point in the parallelization of the method is the solution of the underlying linear systems, which is carried out by means of a multifrontal Choleski method. Second, the water quality simulation problem is approached by using the discrete volume element method. The application of parallel computing is based on dividing the water network in several parts using the multilevel recursive bisection graph partitioning algorithm. Finally, the problem of leakage minimization using pressure reducing valves is approached. This results in the formulation of an optimization problem for each time step, which is solved by means of sequential quadratic programming. Because these subproblems are independent of each other, they can be solved in parallel.The writers wish to acknowledge the financial support provided by the ESPRIT program of the European Commission (HIPERWATER, ESPRIT project 24003), by the CICYT TIC96-1062-C03-01 project, and also by research staff training grants from the Spanish government and the autonomous government of the Comunidad Valenciana in Spain.Alonso Ábalos, JM.; Alvarruiz Bermejo, F.; Guerrero López, D.; Hernández García, V.; Ruiz Martínez, PA.; Vidal Maciá, AM.; Martínez Alzamora, F.... (2000). Parallel Computing in Water Network Analysis and Leakage Minimization. Journal of Water Resources Planning and Management. 126(4):251-260. https://doi.org/10.1061/(ASCE)0733-9496(2000)126:4(251)S251260126

Estimating Stand and Fire-Related Surface and Canopy Fuel Variables in Pine Stands Using Low-Density Airborne and Single-Scan Terrestrial Laser Scanning Data

In this study, we used data from a thinning trial conducted on 34 different sites and 102 sample plots established in pure and even-aged Pinus radiata and Pinus pinaster stands, to test the potential use of low-density airborne laser scanning (ALS) metrics and terrestrial laser scanning (TLS) metrics to provide accurate estimates of variables related to surface and canopy fires. An exhaustive field inventory was carried out in each plot to estimate the main stand variables and the main variables related to fire hazard: surface fuel loads by layers, fuel strata gap, surface fuel height, stand mean height, canopy base height, canopy fuel load and canopy bulk density. In addition, the point clouds from low-density ALS and single-scan TLS of each sample plot were used to calculate metrics related to the vertical and horizontal distribution of forest fuels. The comparative performance of the following three non-parametric machine learning techniques used to estimate the main stand- and fire-related variables from those metrics was evaluated: (i) multivariate adaptive regression splines (MARS), (ii) support vector machine (SVM), and (iii) random forest (RF). The selection of the best modeling approach was based on a comparison of the root mean square error (RMSE), obtained by optimizing the parameters of each technique and performing cross-validation. Overall, the best results were obtained with the MARS techniques for data from both sensors. The TLS data provided the best results for variables associated with the internal characteristics of canopy structure and understory fuel but were less reliable for estimating variables associated with the upper canopy, due to occlusion by mid-canopy foliage. The combination of ALS and TLS metrics improved the accuracy of estimates for all variables analyzed, except the height and the biomass of the understory shrubs. The variability demonstrated by the combined use of both types of metrics ranged from 43.11% for the biomass of duff litter layers to 94.25% for dominant height. The results suggest that the combination of machine learning techniques and metrics derived from low-density ALS data, drawn from a single-scan TLS or a combination of both metrics, may represent a promising alternative to traditional field inventories for obtaining valuable information about surface and canopy fuel variables at large scalesinfo:eu-repo/semantics/publishedVersio

Estimating Stand and Fire-Related Surface and Canopy Fuel Variables in Pine Stands Using Low-Density Airborne and Single-Scan Terrestrial Laser Scanning Data

[EN] In this study, we used data from a thinning trial conducted on 34 different sites and 102 sample plots established in pure and even-aged Pinus radiata and Pinus pinaster stands, to test the potential use of low-density airborne laser scanning (ALS) metrics and terrestrial laser scanning (TLS) metrics to provide accurate estimates of variables related to surface and canopy fires. An exhaustive field inventory was carried out in each plot to estimate the main stand variables and the main variables related to fire hazard: surface fuel loads by layers, fuel strata gap, surface fuel height, stand mean height, canopy base height, canopy fuel load and canopy bulk density. In addition, the point clouds from low-density ALS and single-scan TLS of each sample plot were used to calculate metrics related to the vertical and horizontal distribution of forest fuels. The comparative performance of the following three non-parametric machine learning techniques used to estimate the main stand-and fire-related variables from those metrics was evaluated: (i) multivariate adaptive regression splines (MARS), (ii) support vector machine (SVM), and (iii) random forest (RF). The selection of the best modeling approach was based on a comparison of the root mean square error (RMSE), obtained by optimizing the parameters of each technique and performing crossvalidation. Overall, the best results were obtained with the MARS techniques for data from both sensors. The TLS data provided the best results for variables associated with the internal characteristics of canopy structure and understory fuel but were less reliable for estimating variables associated with the upper canopy, due to occlusion by mid-canopy foliage. The combination of ALS and TLS metrics improved the accuracy of estimates for all variables analyzed, except the height and the biomass of the understory shrubs. The variability demonstrated by the combined use of both types of metrics ranged from 43.11% for the biomass of duff litter layers to 94.25% for dominant height. The results suggest that the combination of machine learning techniques and metrics derived from low-density ALS data, drawn from a single-scan TLS or a combination of both metrics, may represent a promising alternative to traditional field inventories for obtaining valuable information about surface and canopy fuel variables at large scalesSIThis research was funded by the projects GEPRIF (RTA2014-00011-C06-04) and VIS4FIRE (RTA2017-00042-C05-05) of the Spanish Ministry of Economy, Industry, and Competitiveness and a pre-doctoral grant of the first author funded by the “Consejería de Educación, Universidad y Formación Profesional” and the “Consejería de Economía, Empleo e Industria” of the Galician Government and the EU operational program “FSE Galicia 2014–2020”

Entrenamiento de una red neuronal en LabVIEW para la identificación en línea de un sistema dinámico

En el presente trabajo se describe el diseño de un instrumento virtual implementado en LabVIEW para el uso, creación y entrenamiento de redes neuronales artificiales mediante el algoritmo de retropropagación. Como prueba de su correcto funcionamiento se realiza la identificación de un sistema dinámico en línea y la adaptación del instrumento virtual para generar redes recurrentes; el sistema dinámico es un sistema resistivo – capacitivo. Por último, se comparan los resultados de varias redes entrenadas con diferentes estructuras

Pretreatment of urine samples with SDS improves direct identification of urinary tract pathogens with matrix-assisted laser desorption ionization-time of flight mass spectrometry

[EN]We pretreated with SDS 71 urine samples with bacterial counts of >10(5) CFU/ml and matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) identification scores of <2, in order to minimize failure rates. Identification improved in 46.5% of samples, remained unchanged in 49.3%, and worsened in 4.2%. The improvement was more evident for Gram-negative (54.3%) than for Gram-positive (32%) bacteria

EL PAPEL SOCIAL DEL MEGALITISMO EN EL SURESTE DE LA PENÍNSULA IBÉRICA. LAS COMUNIDADES MEGALÍTICAS DEL PASILLO DE TABERNAS

We have tried to discover the meaning of the megalithic tombs from an intensive survey in the Pasillo de Tabernas through the choice and statistical analysis of different data. We have also tried to explain the differences in tombs location among the distinct areas, not only the aggregated tombs near the most important settlements but also the lonely and scattered one salong the mountains. Finally sorne commentaries are made about the relation between these communities and the neighbouring ones in Almanzora and Andarax vales.A partir de una prospección intensiva desarrollada en el Pasillo de Tabernas (Almería) hemos procedido a tratar de valorar el significado de las tumbas megalíticas localizadas desde de la elección de una serie de diferentes variables y su estudio estadístico. Se ha intentado también explicar las diferencias de situación de las tumbas entre unas zonas y otras de este Pasillo, desde las que se sitúan concentradas en torno a los poblados más importantes a aquellas otras que se disponen alineadas por las sierras. Por último se realizan algunas reflexiones sobre la relación de estas comunidades con las que ocupan el valle del Andarax y con las que se sitúanen el valle del Almanzora al otro lado de los Filabres

Estudio de la estructura de recubrimientos de silicio depositados mediante proyección térmica por llama oxiacetilénica

RESUMEN: Se estudió el efecto del tipo de llama, del tipo de sustrato y de la distancia de proyección sobre la porosidad y el espesor de recubrimientos de silicio depositados por medio de proyección térmica por llama oxiacetilénica. Para la elaboración de los recubrimientos se utilizó una llama reductora, una neutra y una oxidante, con el objetivo de calentar y posteriormente proyectar las partículas de silicio sobre sustratos de aluminio y de Ti6Al4V, a una distancia de proyección de 15 cm y 8.5 cm. Los resultados indican que los recubrimientos depositados a 8.5 cm son más compactos y que la utilización de una llama neutra reduce ligeramente la porosidad y permite tener capas más gruesas. Así mismo, los recubrimientos depositados sobre sustratos de Ti6Al4V presentaron menor porosidad y menos fallas estructurales que los depositados sobre aluminio.ABSTRACT: The effect of flame type, material substrate and spray distance on the porosity and thickness of silicon coatings elaborated by oxy-acetylene flame spray were studied. Reductive, neutral and oxidative flames were used in order to manufacture the coatings on aluminum and Ti6Al4V substrates, using spray distances of 15 cm and 8.5 cm. The results indicate that the coatings elaborated using a spray distance of 8.5 cm are more compact than those manufactured using a spray distance of 15 cm and that the use of a neutral flame slightly decreases the porosity increases thickness. Also the porosity and structural defects in coatings elaborated on Ti6Al4V substrates are lower than those manufactured on aluminum

Clinical and Non-Clinical Variables Associated With Preventive and Curative Dental Service Utilisation: A Cross-Sectional Study Among Adolescents and Young Adults in Central Mexico

Objective The present study aimed to identify preventive and curative dental health service utilisation (DHSU) in the context of associated clinical and non-clinical factors among adolescents and young adults in Mexico. Design Cross-sectional study. Setting Applicants to a public university in Mexico. Participants Participants were 638 adolescents and young adults aged 16–25 randomly selected from university applicants. Interventions Data were collected using a self-administered questionnaire filled out by the students. For assessment of dental caries experience, we used the index of decayed, missing and filled teeth. Primary outcome The dependent variable was DHSU in the previous 12 months, coded as 0=non-use, 1=use of curative services and 2=use of preventive services. Results The mean age was 18.76±1.76 years, and 49.2% were women. The prevalence of DHSU was 40.9% (95% CI 37.1 to 44.8) for curative services and 22.9% (95% CI 19.7 to 26.3) for preventive services. The variables associated with curative services were age, sex, mother’s education, dental pain in the previous 12 months, caries experience, use of self-care devices and oral health knowledge. For preventive services, the variables associated were mother’s education, dental pain in the previous 12 months, caries experience, use of self-care devices and self-perception of oral health. Conclusions While differences emerged by type of service, a number of variables (sociodemographic and socioeconomic characteristics as well as dental factors) remained in the final model. Greater oral health needs and socioeconomic inequalities remained as predictors of both types of DHSU. Given the differences revealed by our study, oral health policies should refer those seeking dental care for oral diseases to preventive services, and promote the use of such services among the poorer and less educated population groups

Prepolarized MRI of Hard Tissues and Solid-State Matter

[EN] Prepolarized MRI (PMRI) is a long-established technique conceived to counteract the loss in signal-to-noise ratio (SNR) inherent to low-field MRI systems. When it comes to hard biological tissues and solid-state matter, PMRI is severely restricted by their ultra-short characteristic relaxation times. Here we demonstrate that efficient hard-tissue prepolarization is within reach with a special-purpose 0.26 T scanner designed for ex vivo dental MRI and equipped with suitable high-power electronics. We have characterized the performance of a 0.5 T prepolarizer module, which can be switched on and off in 200 mu s. To this end, we have used resin, dental and bone samples, all with T1$${\mathbf{T}}_{\mathbf{1}}$$ times of the order of 20 ms at our field strength. The measured SNR enhancement is in good agreement with a simple theoretical model, and deviations in extreme regimes can be attributed to mechanical vibrations due to the magnetic interaction between the prepolarization and main magnets.Agencia Valenciana de la Innovaci~o; European Regional Development Fund; Ministerio de Ciencia e Innovacion; This work was supported by the Ministerio de Ciencia e Innovaci~on of Spain through research grant PID2019-111436RBC21. Action co-financed by the European Union through the Programa Operativo del Fondo Europeo de Desarrollo Regional (FEDER) of the Comunitat Valenciana 2014-2020 (IDIFEDER/2018/022). JMG and JB acknowledge support from the Innodocto program of the Agencia Valenciana de la Innovacion (INNTA3/2020/22 and INNTA3/2021/17); Ministerio de Ciencia e Innovaci~on of Spain, Grant/Award Number: PID2019-111436RB-C21; Programa Operativo del Fondo Europeo de Desarrollo Regional (FEDER) of the Comunitat Valenciana, Grant/Award Number: IDIFEDER/2018/022; Innodocto program of the Agencia Valenciana de la Innovacion, Grant/Award Numbers: INNTA3/2020/22, INNTA3/2021/17Borreguero-Morata, J.; González Hernández, JM.; Pallás Lodeiro, E.; Rigla, JP.; Algarín-Guisado, JM.; Bosch-Esteve, R.; Galve, F.... (2022). Prepolarized MRI of Hard Tissues and Solid-State Matter. NMR in Biomedicine. 35(8):1-10. https://doi.org/10.1002/nbm.473711035