Repositorios digitales y taxonomías de términos clave en Educación Matemática

En este documento presentamos el proyecto Funes, un repositorio electrónico de documentos en Educación Matemática y describimos el procedimiento que seguimos para establecer la taxonomía de términos clave con el que se clasifican los documentos que se incluyen en el repositorio. Funes busca contribuir a la consolidación de la comunidad iberoamericana de Educación Matemática, al proporcionar un espacio virtual en el que profesores, innovadores e investigadores puedan compartir su producción escrita y puedan aprender mutuamente a partir de ella

Funes: depósito electrónico de documentos en Educación Matemática

En este documento justificamos la necesidad de aprovechar las oportunidades que ofrece actualmente la tecnología para compartir el conocimiento y aprender de los demás. Presentamos el proyecto Funes, un depósito electrónico de documentos en Educación Matemática. Su propósito es contribuir a la consolidación de la comunidad iberoamericana de Educación Matemática al proporcionar un espacio virtual en el que profesores, innovadores e investigadores en Educación Matemática pueden compartir su producción escrita y pueden aprender mutuamente a partir de ella

Funes: un repositorio digital para publicar y compartir documentos en Educación Matemática

Presentamos el proyecto Funes, un repositorio electrónico de documentos en Educación Matemática. Su propósito es contribuir a la consolidación de la comunidad iberoamericana de Educación Matemática, al proporcionar un espacio virtual en el que profesores, innovadores e investigadores pueden compartir su producción escrita y pueden aprender mutuamente a partir de ella

Dechlorination of polyvinyl chloride electric wires by hydrothermal treatment using K2CO3 in subcritical water

Polyvinyl chloride (PVC) waste generation has significantly increased in recent years and their disposal is considered a major environmental concern. Removal techniques of chlorine from PVC waste are being studied to minimize a negative environmental impact. In this work, the use of K2CO3 as an alkaline additive to improve the dechlorination efficiency (DE) in the hydrothermal degradation of PVC wires was studied. Different experiments were carried out varying both temperature (175, 200, 225, 235 and 250 °C) and K2CO3 concentration (0.025, 0.050 and 0.125 M), using a solid/liquid ratio of 1:5 in order to determine the evolution of the dechlorination efficiency with time. About 4.66, 21.1, 24.4, 45.7 and 92.6 wt% of chlorine in PVC wire was removed during hydrothermal dechlorination (HTD) with an additive/chlorine ratio of 1:25 (K2CO3 solution of 0.050 M) at 175, 200, 225, 235 and 250 °C, respectively. Optimal additive/chlorine ratio decreased to 1:50 (K2CO3 solution of 0.025 M) at 250 °C, obtaining a dechlorination degree of 99.1% after 4 h without the need of metallic catalysts. Concerning the solid phase behavior during dechlorination, a linear correlation between the DE reached and the weight loss of PVC was found.Support for this work was provided by the CTQ2016-76608-R project and the scholarship BES-2017-080382 from the Ministry of Economy Industry and Competitiveness (Spain)

Virtual Trip to the Abric Romaní site and its lithic procurement areas

This paper introduces the virtual field trip organised on the occasion of the 13th International Symposium on Knappable Materials in Tarragona from 4th to 6th October 2021, showing the Abric Romaní site (NE Iberian Peninsula) and the chert procurement areas located within a 30 km radius. The Abric Romaní section consists of a general presentation of the Middle Palaeolithic site, including a brief description of its 50 m stratigraphic sequence, where more than 20 archaeological levels have been identified dating from 110 to 39 ka BP, and some of the main traits of the archaeological assemblages have been recovered. This was followed by an introduction of the siliceous outcrops of the Panadella cherts approximately 24 km from the Abric Romaní; the Sant Martí de Tous chert outcrops 16 km away and the Valldeperes and Ca l’Alemany chert outcrops at distances of 24 and 25 km, respectively. In all cases, the geological formations, as well as the main chert macroscopic and microscopic characteristics, are described. This paper yields the most relevant aspects of a field trip that had to be recorded due to the COVID-19 pandemic, but which brought us back together and facilitated the presentation of the main source areas frequented by the Neanderthals groups of this referential site.En este trabajo se presenta la salida de campo virtual organizada con motivo del 13th International Symposium on Knappable Materials organizado en Tarragona del 4 al 6 de octubre de 2021, en el que se muestra el yacimiento de Abric Romaní (NE de la Península Ibérica) y las zonas de captación de sílex situadas en un radio de 30 km. La sección del Abric Romaní consiste en una presentación general del yacimiento del Paleolítico Medio, incluyendo una breve descripción de su secuencia estratigráfica de 50 m, donde se han identificado más de 20 niveles arqueológicos datados entre 110 y 39 ka BP, y se presentan de manera general los principales rasgos de los conjuntos arqueológicos. A continuación, se han introducido los afloramientos silíceos de los sílex de la Panadella a unos 24 km del Abric Romaní; los afloramientos de sílex de Sant Martí de Tous a 16 km y los afloramientos de sílex de Valldeperes y Ca l'Alemany a distancias de 24 y 25 km, respectivamente. En todos los casos se describen las formaciones geológicas, así como las principales características macroscópicas y microscópicas del sílex. En este trabajo se recogen los aspectos más relevantes de la salida de campo que tuvo que ser grabada debido a la pandemia del COVID-19, pero que nos volvió a reunir y facilitó la presentación de las principales zonas de captación silícea frecuentadas por los grupos neandertales de este yacimiento en cuestión

Dopaminergic Denervation Impairs Cortical Motor and Associative/Limbic Information Processing Through the Basal Ganglia and its Modulation by the CB1 Receptor

The basal ganglia (BG) are involved in cognitive/motivational functions in addition to movement control. Thus, BG segregated circuits, the sensorimotor (SM) and medial prefrontal (mPF) circuits, process different functional domains, such as motor and cognitive/motivational behaviours, respectively. With a high presence in the BG, the CB1 cannabinoid receptor modulates BG circuits. Furthermore, dopamine (DA), one of the principal neurotransmitters in the BG, also plays a key role in circuit functionality. Taking into account the interaction between DA and the endocannabinoid system at the BG level, we investigated the functioning of BG circuits and their modulation by the CB1 receptor under DA-depleted conditions. We performed single-unit extracellular recordings of substantia nigra pars reticulata (SNr) neurons with simultaneous cortical stimulation in sham and 6-hydroxydopamine (6-OHDA)-lesioned rats, together with immunohistochemical assays. We showed that DA loss alters cortico-nigral information processing in both circuits, with a predominant transmission through the hyperdirect pathway in the SM circuit and an increased transmission through the direct pathway in the mPF circuit. Moreover, although DA denervation does not change CB1 receptor density, it impairs its functionality, leading to a lack of modulation. These data highlight an abnormal transfer of information through the associative/limbic domains after DA denervation that may be related to the non-motor symptoms manifested by Parkinson's disease patients.This study was supported by grants from the Basque Government (PIBA 2019-38), the University of the Basque Country (GIU19/092), and the MINECO fund SAF2016-77758-R (AEI/FEDER, UE). M.A, has a fellowship from the MECD

Improving efficiency and feasibility of subcritical water debromination of printed circuit boards E-waste via potassium carbonate adding

Waste printed circuit boards (WCBs) were debrominated under hydrothermal treatment, using potassium carbonate as an alkaline additive to improve debromination efficiency (DE). Two different high-pressure reactors were used: a 1-L stirred reactor, where the evolution of the DE was followed over time at a low CO32−/Br− ratio (1:25), and an elementary 0.1-L non-stirred reactor, used to find the optimal parameters and to simplify the hydrothermal debromination (HTD) process. Considering both reactors, experiments were conducted changing the temperature (200 °C, 225 °C, 250 °C, 275 °C), and also the CO32−/Br− anionic ratio (1:50, 1:25, 1:10, 1:5, 1:2.5, 1:1, 2:1, 4:1) and the solid/liquid ratio (1:10, 1:5, 1:2) in the case of the 0.1-L reactor. No metallic catalyst was required. A maximum DE of about 98.9 wt % was reached in the agitated vessel at 275 °C after 4 h, with an additive/bromine ratio of 1:25. Similar DE (99.6 wt %) was also achieved in the non-stirred reactor at only 225 °C and after 2 h, using an additive/bromine ratio of 4:1 and a solid/liquid ratio of only 1:2. Concerning the solid phase behaviour during debromination, only 5 % of the net calorific value (NCV) was lost after a complete HTD treatment of WCB.Support for this work was granted by CTQ2016-76608-R project and the scholarship BES-2017-080382 from the Ministry of Economy, Industry and Competitiveness (Spain)

Retrospective study of the prevalence of postanesthtic hypotermia in dogs

The anaesthetic records of 1525 dogs were examined to determine the prevalence of postanaesthetic hypothermia, its clinical predictors and consequences. Temperature was recorded throughout the anaesthesia. At the end of the procedure, details coded in were: hyperthermia (>39.50°C), normothermia (38.50°C–39.50°C), slight (38.49°C–36.50°C), moderate (36.49°C–34.00°C) and severe hypothermia (<34.00°C). Statistical analysis consisted of multiple regression to identify the factors that are associated with the temperature at the end of the procedure. Before premedication, the temperature was 38.7±0.6°C (mean±sd). At 60, 120 and 180 minutes from induction, the temperature was 36.7±1.3°C, 36.1±1.4°C and 35.8±1.5°C, respectively. The prevalence of hypothermia was: slight, 51.5 per cent (95 per cent CI 49.0 to 54.0 per cent); moderate, 29.3 per cent (27.1–31.7 per cent) and severe: 2.8% (2.0–3.7%). The variables that associated with a decrease in the temperature recorded at the end of the anaesthesia were: duration of the preanesthetic time, duration of the anaesthesia, physical condition (ASA III and ASA IV dogs showed lower temperatures than ASA I dogs), the reason for anaesthesia (anaesthesia for diagnostic procedures or thoracic surgery reduce the temperature when compared with minor procedures), and the recumbency during the procedure (sternal and dorsal recumbencies showed lower temperatures than lateral recumbency). The temperature before premedication and the body surface (BS) were associated with a higher temperature at the end of the anaesthesia, and would be considered as protective factors.Ciencias Experimentale