Errors in algebraic statements translation during the creation of an algebraic domino

We present a research study which main objective is to inquire into secondary school students´ ability to translate and relate algebraic statements which are presented in the symbolic and verbal representation systems. Data collection was performed with 26 14-15 years old students to whom we proposed the creation of an algebraic domino, designed for this research, and its subsequent use in a tournament. Here we present an analysis of the errors made in such translations. Among the obtained results, we note that the students found easier to translate statements from the symbolic to the verbal representation and that most errors in translating from verbal to symbolic expressions where derived from the particular characteristics of algebraic language. Other types of errors are also identified. KEYWORDS: Algebraic language, domino, errors, translation between representation systems, verbal representation

Polymeric foams as the matrix of voltammetric sensors for the detection of catechol, hydroquinone, and their mixtures

Producción CientíficaPorous electrodes based on polymethylmethacrylate and graphite foams (PMMA_G_F) have been developed and characterized. Such devices have been successfully used as voltammetric sensors to analyze catechol, hydroquinone, and their mixtures. The presence of pores induces important changes in the oxidation/reduction mechanism of catechol and hydroquinone with respect to the sensing properties observed in nonfoamed PMMA_graphite electrodes (PMMA_G). The electropolymerization processes of catechol or hydroquinone at the electrode surface observed using PMMA_G do not occur at the surface of the foamed PMM_G_F. In addition, the limits of detection observed in foamed electrodes are one order of magnitude lower than the observed in the nonfoamed electrodes. Moreover, foamed electrodes can be used to detect simultaneously both isomers and a remarkable increase in the electrocatalytic properties shown by the foamed samples, produces a decrease in the oxidation potential peak of catechol in presence of hydroquinone, from +0.7 V to +0.3 V. Peak currents increased linearly with concentration of catechol in presence of hydroquinone over the range of 0.37·10−3 M to 1.69·10−3 M with a limit of detection (LOD) of 0.27 mM. These effects demonstrate the advantages obtained by increasing the active surface by means of porous structures.Ministerio de Economía, Industria y Competitividad - Fondo Europeo de Desarrollo Regional (project AGL2015-67482-R)Junta de Castilla y Leon - Fondo Europeo de Desarrollo Regional (project VA-011U16

Estudio de los picos tallados de la época preeuropea de Gran Canaria. Un ejemplo de especialización en el trabajo a partir de las evidencias recuperadas en la cantera de molinos de Montaña Quemada

In this paper we present the study of chipped stone picks. These instruments were employed to work rocks in several ways(working in quarries, excavating mine galleries and other enclosures, manufacturing tools, etc.). The artifacts were recoveredin the excavation of a quarry for the production of rotator milling stones (Montaña Quemada, Gran Canaria). In thequarries intensive productive processes were developed, where picks were submitted to strong mechanical and frictionalstresses, which caused frequent accidents requiring continuous repairs. These circumstances made it necessary to developa type of artifact with technical features that allowed reshaping and resharpening tasks in order to extend its active life. Acombination of morphotechnical and functional studies, along with the refitting results, have enabled us to reconstruct theirknapping and use strategies, showing a high level of skill. In addition, this analysis has involved defining, for the first time,the different categories of byproducts generated during the process of the configuration and reconfiguration of the picks.Their detailed description will make it possible to recognize them in other archaeological contexts.En este artículo se presentan los resultados del estudio de una muestra de picos de piedra tallada, útiles empleadospara trabajar la piedra en diversas labores (cantería, excavación de cuevas y minas, fabricación de herramientas…),procedentes de la excavación de una cantera de molinos de mano rotatorios (Montaña Quemada, Gran Canaria). Enlas canteras se desarrollaron unos procesos productivos intensivos, en los que los picos eran sometidos a un fuerteestrés mecánico y de fricción, que provocaba numerosos accidentes y desgastes, exigiendo continuas reparaciones. Elloobligó a concebir un tipo de artefacto con unas características que permitieran realizar gestos de remodelación queperduraran su vida activa. La combinación de los estudios morfotécnicos, funcionales y los remontajes obtenidos hapermitido reconstruir unas estrategias de talla y de uso que revelan un gran conocimiento del arte de la talla y la cantería.En este análisis se han definido por primera vez las diversas categorías de productos generados en esos procesos,lo que permitirá reconocerlas en los diversos contextos arqueológicos de la isla

Protein S-nitrosylation in plants under abiotic stress: an overview

Abiotic stress is one of the main problems affecting agricultural losses, and understanding the mechanisms behind plant tolerance and stress response will help us to develop new means of strengthening fruitful agronomy. The mechanisms of plant stress response are complex. Data obtained by experimental procedures are sometimes contradictory, depending on the species, strength, and timing applied. In recent years nitric oxide has been identified as a key signaling molecule involved in most plant responses to abiotic stress, either indirectly through gene activation or interaction with reactive oxygen species and hormones; or else directly, as a result of modifying enzyme activities mainly by nitration and S-nitrosylation. While the functional relevance of the S-nitrosylation of certain proteins has been assessed in response to biotic stress, it has yet to be characterized under abiotic stress. Here, we review initial works about S-nitrosylation in response to abiotic stress to conclude with a brief overview, and discuss further perspectives to obtain a clear outlook of the relevance of S-nitrosylation in plant response to abiotic stress.Peer reviewedPeer Reviewe

Enhanced recovery after surgery pathways in thoracic surgery, do they end at discharge?

Fast track pulmonary resection protocols have shown to be feasible and to improve hospital related costs, shortening length of stay and maintaining quality of care (1-4). Despite the increasing number of scientific literature addressing the benefits of specific lobectomy pathways (4,5) and the recent publication of Enhanced Recovery after Surgery (ERAS®) guidelines in thoracic surgery (4-6) the truth is that the description of most of these interventions ends at patients’ discharge, with no clear indications for follow up or measures to prevent unintended hospital readmissions (2,3

El Efecto De La Implantación Temprana En Niños Con Hipoacusia

Hearing loss in pediatric population is a major health concern, taking into account the immediate repercussions on the cognitive, emotional and language development (serious difficulties in communication and language development). Therefore, it is of crucial importance its early diagnosis and implantation. The objective of this study is to know the effect of cochlear implant on the development of oral language in implanted children in the Province of Santa Cruz de Tenerife (Canary Islands). In order to carry out this research, the psycholinguistic profiles of children who were implanted between 2011 and 2014 were studied, through the use of two standardized tests, Peabody Picture Vocabulary Test and The Illinois Test of Psycholinguistic Abilities (ITPA). As regards the age of implantation, we could observe a significant tendency to use the visual channel in the communication of those children who were implanted at a later age and a tendency to use the auditory channel at an early age of implantation. Children who were implanted at a later age showed a nonfunctional use of the implant and a limited development of their speaking skills

Surfing the waves: environmental and socio-economic aspects of surf tourism and recreation

Marine ecosystems contribute to human well-being, e.g. through the promotion of nature-based recreational activities such as surfing, which is a benefit obtained from Cultural Ecosystem Services (CES). Our research objective is to identify the benefits and impacts associated to surfing, and who are the main affected subjects and/or objects, achieving a better understanding of the sustainability status of this recreational activity. To this end, a bibliometric study and systematic review was carried out for the period 1965–2021. Benefits and impacts were collated and grouped according to their dimensional focus and type of effects in 6 groups (3-dimensional focus × 2 type of effects). The results revealed that since the beginning of 21st century surfing research topics are growing and diversifying. This review shows that implications of surfing go beyond direct users (i.e., surfers) and has consequences in diverse dimensions (environmental, socio cultural and economic), involving many stakeholders (e.g., scientific, and local communities). Most of the pieces of evidence collated in this research were related with the people who practice the activity and its social implications (psychological benefits as main benefit and injuries as main impact). Following an interdisciplinary approach, we obtained a holistic understanding of the surfing activity, not only in terms of the different dimensions addressed but on the sectors of the society that obtain benefits or are impacted by the activity. All of them should be considered and integrated to guarantee the sustainable management of this CES benefit.Financiado para publicación en acceso aberto: Universidade de Vigo/CISU

Improving NDT with Automatic Test Case Generation

The model-driven development defi nes the software development process as a set of iterations to create models and a set of transformations to obtain new models. From this point of view, this paper presents the enhancement of a model- driven approach, called navigational development techniques (NDT), by means of new models and transformations in order to generate test cases. It also states some conclusions from the research work and practical cases in which this approach was used.Ministerio de Ciencia e Innovación TIN2010-20057-C03-02Ministerio de Ciencia e Innovación TIN 2010-12312-

Citizens’ media in latin america

There are several reasons that explain why community and citizens’ media are so widespread and popular in Latin America. This chapter offers a series of short vignettes set in Colombia that describe the intricate processes that developed there since the 1920s and simultaneously elsewhere across Latin America, spreading the notion that agency and participation are everyone’s right. These vignettes highlight why understanding community and citizens’ media in Latin America requires recognizing the long history of radical politics in the region and the wide dissemination of leftist ideologies that popularized notions of popular participation and political agency as rights. The chapter also brings into dialogue the work of Peruvian scholar Rosa María Alfaro, who was instrumental in transforming communication scholarship in Latin America and is an early example of citizens’ media in Latin America. Including a translation of this key early text by Alfaro was a challenge, because the field is vast and there is so much material that has never been translated into English or published outside of Latin America. In selecting the following piece, the intention is to maintain the centrality of both theory and practice and to show how citizens’ media in Latin America cannot be understood unless we take into consideration what social movements and grassroots communities did in the region and how Latin American scholars thought about the region