Computador x papel, suor e caneta: percepção dos alunos sobre as avaliações realizadas em computadores

ABSTRACTThis study aims to verify the perception of undergraduate students in Economics of a public university, who were taking an introductory Accountancy course, about using computers to do bimonthly exams. Therefore, instead of usual paper and pen, the exams were electronically applied, with support of an online environment and the possibility of using electronic spreadsheets. After the implementation of two bimonthly tests, students were asked to answer a questionnaire adapted from an Apostolou et al. (2009) research, in order to obtain data about their perception of the advantages and disadvantages of online tests compared to traditional tests. Two classes, totaling 83 students, took part in the research. Results show that, most students (87%) are more prone to the realization of electronic tests. Some points stood out as being highly positive about online tests, such as flexibility for the realization of exercises, quicker feedback of the results and the elimination of the need of attending tests. As for the negative points, students indicated the elimination of discursive questions (in case the test has only direct questions). As a tool to identify hindrances to the adoption of electronic tests, the group of students who showed a negative perception was analyzed more closely, searching evidence to explain the lack of trust on that procedure. Analyzing the variables, students who do not trust in online tests have the perception that they limit the subject, they allow students to copy the answers (cheat) from each other (or from other sources), and affect negatively the grades obtained

Second Life for Plastic Fibre Waste Difficult to Recover: Partial Replacement of the Binder in Asphalt Concrete Mixtures by Dry Incorporation

ABSTRACT: In previous studies, different additives and modifiers have been studied to improve the properties of asphalt concrete mixtures, whose main failures are plastic deformation and cracking. In this research, the improvement of the properties of asphalt concrete mixtures were investigated by introducing residual plastics as a substitute for virgin bitumen, which improves the sustainability of the mixtures. Furthermore, the results obtained from these new mixtures were compared with a mixture designed with polymer-modified bitumen (PMB). Ten experimental designs were tested with three types of waste fibre plastics from a municipal solid waste treatment plant and two percentages of bitumen replacement (15% and 25%). The experimental testing plan included air void characterization, moisture sensitivity, stiffness and fatigue resistance, among others. An increase of approximately 5% in voids could be observed when introducing the plastic material and therefore some tests were carried out to over-compact the specimens. The results showed an improvement in the mechanical performance of the experimental mixtures, highlighting the resistance against plastic deformations, which even reached similar values to the mixtures made with PMB.This publication is part of the I+D+I project PID2019-110797RB-I00, funded by MCIN/AEI/ 10.13039/501100011033. PRE2020-093516 assistance financed by MCIN/ AEI/10.13039/501100011033 and FSE “FSE invests in your future”

Gaussianization of LA-ICP-MS features to improve calibration in forensic glass comparison

The forensic comparison of glass aims to compare a glass sample of an unknown source with a control glass sample of a known source. In this work, we use multi-elemental features from Laser Ablation Inductively Coupled Plasma with Mass Spectrometry (LA-ICP-MS) to compute a likelihood ratio. This calculation is a complex procedure that generally requires a probabilistic model including the within-source and betweensource variabilities of the features. Assuming the within-source variability to be normally distributed is a practical premise with the available data. However, the between-source variability is generally assumed to follow a much more complex distribution, typically described with a kernel density function. In this work, instead of modeling distributions with complex densities, we propose the use of simpler models and the introduction of a data pre-processing step consisting on the Gaussianization of the glass features. In this context, to obtain a better fit of the features with the Gaussian model assumptions, we explore the use of different normalization techniques of the LA-ICP-MS glass features, namely marginal Gaussianization based on histogram matching, marginal Gaussianization based on Yeo-Johnson transformation and a more complex joint Gaussianization using normalizing flows. We report an improvement in the performance of the Likelihood Ratios computed with the previously Gaussianized feature vectors, particularly relevant in their calibration, which implies a more reliable forensic glass comparisonThis work has been supported by the Spanish Ministerio de Ciencia e Innovación through grant PID2021-125943OB-I0

Cobertura de vacunación antigripal en grupos de riesgo menores de 60 años

Introducción: La gripe es una enfermedad que genera cada año un elevado número de hospitalizaciones y muertes potencialmente prevenibles con la administración de su vacuna estacional. Actualmente, durante la pandemia por Covid19, se pone en relieve la necesidad de alcanzar amplias tasas de vacunación de gripe para evitar el colapso de los servicios sanitarios. Además de proteger a la población mayor de 60 años, se debe fomentar la vacunación en población menor de 60 años con factores de riesgo; sobre lo cual existe una escasa información epidemiológica disponible. Objetivos: Conocer el porcentaje aproximado de cobertura vacunal alcanzada durante la campaña 2020/21 en población de riesgo menor de 60 años. Analizar la distribución geográfica de esta población por Zonas Básicas de Salud (ZBS) en la isla de Tenerife. Generar información para mejorar y/o reforzar la vacunación de este grupo poblacional. Metodología: Se trata de un estudio epidemiológico-observacional descriptivo de carácter retrospectivo. Se han recogido datos poblacionales sobre Canarias y de Tenerife en particular, desglosada por ZBS. La información ha sido extraída del sistema informático Drago AP. Resultados: A nivel de Canarias, existe una cobertura del 40,73% en mayores de 60 años, mientras que en la población menor de 60 años con patologías crónicas es del 12,15%. Se observa una amplia dispersión en los datos de vacunación en menores de 60 años sin patologías [3,06% - 12,4%] y con patologías crónicas [5,8% - 18,4%]. Las cifras de vacunación en las ZBS pertenecientes al sur de Tenerife son inferiores a las registradas en la zona norte y metropolitana de la isla. Conclusiones: La cobertura vacunal es significativamente mayor en >60 años en comparación a <60 años. Es necesario tomar medidas en vistas de mejorar la estrategia de vacunación en la población de riesgo joven.Introduction: Influenza is a disease that every year results in a significant number of hospitalizations and deaths potentially preventable with the administration of its seasonal vaccine. Currently, during the Covid19 pandemic, it’s remarkable the need to achieve broad flu vaccination rates in aims to avoid the collapse of health services. Besides protecting the elderly population, vaccination among citizens with risk factors associated and aged 60 or lower should be promoted; on which there is little epidemiological information available. Objectives: To estimate the approximate percentage of flu vaccination coverage achieved during the 2020/21 campaign for the endangered population under 60 years of age. To analyze the geographical distribution of this population by Basic Health Zones (BHZ) on Tenerife island. Generate information to improve and / or reinforce vaccination of this population group. Methodology: It is a retrospective descriptive epidemiological-observational study. Population data from the Canary Islands and Tenerife in particular have been collected, desegregating them by BHZ. The information was obtained from Drago AP’s computer system. Results: As for the Canary Islands, there is a vaccination coverage of 40,73% in people over 60 years old; while in the population aged under 60 with chronic illness it is 12.15%. Vaccination data has a wide dispersion in population under 60 years of age without pathologies [3.06% - 12.4%] and with chronic pathologies [5.8% - 18.4%]. The vaccination coverage in Southern Tenerife BHZs is lower compared to Northern and Metropolitan’s. Conclusions: There is a significantly wider vaccination coverage for people above 60 years old compared to people under 60 years old. It is necessary to take measures for improving the vaccination strategy in the endangered young population

Implementación de un plan estratégico para la empresa de calzado Carubi en el distrito El Porvenir, 2019

La tesis busca implementar un plan estratégico para la empresa de calzados Carubi. El problema surge debido a que existen muchas empresas del mismo rubro lo cual origina gran variabilidad en los precios. El efecto de ello para la empresa la reducción de sus ventas, es por ello que el objetivo es plantear una solución que permita incrementar la rentabilidad de la empresa. La medición fue en cinco empresas del mismo rubro como muestra; el diseño de investigación fue método descriptivo simple. Los datos recogidos con la técnica del focus group. Referente a la competitividad se halló que la empresa inicialmente tenía un factor ponderado de 2.2 que fue hallado mediante la matriz de perfil competitivo, que significa que no está compitiendo fuertemente con otras empresas. El plan estratégico propuesto permitirá incrementar la competitividad en un 45.45% gracias al efecto de sus estrategias en el incremento de los factores claves de éxito como: experiencia 13.67%, calidad del producto 13.67%, competitividad de precios 11%, fidelidad del cliente 13.5% y variedad de productos 12%. Llegando a la conclusión que el plan estratégico propuesto para la empresa de calzados Carubi, le permitirá obtener ventajas competitivas, conforme estimaciones de objetivos a corto plazo

Score-based Bayesian network structure learning algorithms for modeling radioisotope levels in nuclear power plant reactors

Radioactive corrosion products released into the primary coolant loop dominate the final shutdown radiation fields of pressurized water reactors. Thus, reducing the concentration of these corrosion products is a paramount duty in the optimization process of the reactor performance. However, the complexity and uncertainty present in this process make it difficult to predict their evolution in a theoretical way. We propose the application of structural learning of Bayesian networks to discover the complex relations between the corrosion products and the most relevant variables in the primary loop, giving rise to probabilistic models that obtain accurate and reliable predictions of the corrosion products. Our analysis of 5 power plants demonstrates that our approach results in simpler and more reliable models. Additionally, we conclude that the learned structures may represent an interpretable tool for power plant technicians since they reveal useful information that can be directly employed to improve the reactor operationThe authors from the UAM have been supported by the Spanish Ministerio de Ciencia e Innovación, Agencia del Fondo Europeo de Desarrollo Regional (grant reference PID2021-125943OB-I00, MCIN /AEI /10.13039/501100011033/FEDER, UE). The work has been conducted in the context of a signed collaboration agreement between AUDIAS-UAM and ENUSA Industrias Avanzadas S.

Satisfaction, Assessment and Adaptation to a Virtual Environment of the University Mentoring Programme GuíaMe-AC-UMA for Gifted High School Students

The purpose of this study is to analyse the satisfaction levels of participants (mentees, mentors, and technical-research team) of a university mentoring programme. The GuíaMe-AC-UMA is aimed at gifted high school students. Due to the COVID-19 pandemic, the IX edition was carried out in an online format. The results were compared to those of the in-person edition (VII edition) to assess whether there were differences between the editions. For this purpose, three versions (one for each participant type) of a Likert-type questionnaire were distributed among the participants of the 22 workshops offered by the GuíaMe-AC-UMA Programme. A total of 224 responses were received: 21 from the mentors, 181 from the mentees and 22 from the technical-research team. The results indicate a high level of satisfaction with the development of the workshops by all participants. While the mentees preferred the in-person edition, the rest of the participants showed no difference in satisfaction levels between editions. A similar result was observed when correcting for the subject area of the workshop. The in-person edition was valued higher than the online version by all. The overall level of satisfaction shown by all participants and the support for continuation of the programme suggest that this type of educational offer is beneficial and satisfactory for all involved, in accordance with previous research on mentoring programmes. These results indicate that programmes focused on young pre-university students with high abilities are valued; these results encourage us to continue the programmeThis research received no external funding.Partial funding for open access charge: Universidad de Málag

The biological characteristics and distribution of the greenbug, Schizaphis graminum, and Russian wheat aphid, Diuraphis noxia (Hemiptera: Aphididae), in Argentina and Chile

The aphids Schizaphis graminum (Rondani) (greenbug) and Diuraphis noxia (Mordvilko) (Russian wheat aphid, RWA) were collected from several localities in Argentina and Southern Chile. Clones were established from aphids collected at each location. The host preferences were studied in free choice tests. Biotypes were characterized on the basis of aphid antibiosis and host plant tolerance. The production of sexuals was assessed under natural conditions, from March to November in 1997-2001, at La Plata (34°55′ S, 57°57′ W). The greenbug distribution ranged from 24°40′ to 43°28′ S, and was bounded between isothermals 18-20°C and 8-10°C, and isohyets 400-600 mm and greater than 1200 mm. The aphids at all localities were collected from a wide range of cultivated and wild hosts. The biotypes in ten out of thirty-four populations were identified. One population was obligatorily parthenogenetic, the remainder cyclically parthenogenetic. No correlation was found between the region they came from and the period required for the induction of sexuals. RWA was found between 26°50′ and 43°28′S, bounded by the isothermals 20-22°C and 8-10°C, and isohyets 400-600 mm and 2000 mm. In Chile, this aphid was only found in Osorno County, which lies on isothermal 8-10°C and is bounded by the isohyets 1 000 mm and 2000 mm. Only a few RWA genotypes (clones) produced sexuals irrespective of the host they were collected from, period of the year, region, current host, or the day length and average temperature of the rearing conditions. For the first time, RWA was found infesting cultivated as well as wild oats in South America. At low latitudes, populations of both aphid species were found only infesting wild Sorghum halepensis (L).Facultad de Ciencias Agrarias y Forestale

Fresnel solar cooling plant for buildings: Optimal operation of an absorption chiller through inverse modelling

Increasing comfort conditions in buildings imply higher energy demands. However, these needs can be mitigated by solar cooling solutions. These systems, such as absorption chillers, are complex and require stable operation, with strict control to maximise the solar fraction and minimise gas consumption. This is incompatible with the variability of renewable resources, so they are often coupled with auxiliary gas systems. Although gas-free operation is possible if these systems are optimally controlled, they would require special supervision. This paper aims to develop an experimental validation of an inverse model to manage an absorption chiller coupled with a solar cooling plant. To know its real behaviour, long-term experiments have been performed using this plant, which consists of a linear Fresnel solar collector and an auxiliary natural gas boiler. The inverse model is used as a predictive control tool to decide the auxiliary boiler commands of the absorption chiller to optimise its operation: maximum cooling production by minimising gas consumption and maximising solar contribution. It has been identified with data from two weeks and validated with data from one summer month. Results show that the model estimates, on a time base of fewer than 30 min, are acceptable with errors of less than 5%. In addition, the maximum error of the estimated seasonal COP and the renewable fraction are less than 6% per day. Therefore, the results prove the usefulness of the proposal as a predictive control for optimal operation. Furthermore, it could be used as a baseline for preventive maintenance. If the proposed model is used for optimal management of the absorption chiller, the thermal efficiency of the plant increases significantly, doubling the solar contribution. As a result, the gas consumption of the solar cooling plant is halved and the total cost of air conditioning the building decreases by 16%.Comisión Europea A_B.4.3_02

Identificación de enfermedad carotídea y cardioembolismo en infarto cerebral. Hospital “Teodoro Maldonado Carbo”, período 1998-2001

Estudio realizado en el Servicio de Neurología del Hospital Teodoro Maldonado Carbo en pacientes con enfermedad cerebro vascular (ECV) isquémico.Tipo de estudio: Descriptivo, analítico, el análisis estadístico se realizó midiendo población y variables mediante reportes de frecuencias, media, proporciones y razón.Objetivo: Describir los posibles factores etiológicos. Determinar las características de la población.Resultados: De un total de 532 pacientes con ECV isquémico, 345 fueron de origen aterotrombótico y 187 de origen embólico; 30 enfermedades carotídea, 11 patología mixta y 60 causa desconocida. Se encontró que la mayor frecuencia por edad estuvo entre los 61–70 años (28%) de la totalidad de infarto cerebral embólico (ICE); el sexo predominante fue el masculino con 135 y mujeres 52. Entre los hallazgos de los estudios de neuroimágenes encontramos: evidencias de lesiones isquémicas en múltiples territorios vasculares, infartos que comprometen la corteza cerebral y área subcortical subyacente y presencia de transformaciones hemorrágicas evidentes.Conclusiones: La mayoría de los datos obtenidos coincidieron con la literatura mundial a excepción de los datos de enfermedad carotídea con un menor porcentaje, posiblemente por la falta de recursos para completar los estudios de gabinete