Meanings of the concept of finite limit of a function at a point: Background and Results

Eight Congress of European Research in Mathematics Education (CERME 8). Manavgat-Side, Antalya - Turkey, 6-10 February 2013.In this paper we present a description of previous work carried out by the authors on the general issue of designing and implementing a didactical planning for Spanish students from non-compulsory secondary education, 16-17 years old. The current research has as its aim to describe the meanings that students associate to specific terms from the language, such as, “to approach,” “to tend,”“to reach,”“to exceed,” and “to converge.” Prior to the study, we reviewed the mathematical use of these terms and we contrast this with the colloquial use of the terms. From the semi- structured interviews used to gather information, we provide an analysis of the written data. It is important to highlight that students have contributed with a variety of meanings, in addition to those from the previous review.This study was performed with aid and financing from Fellowship FPU AP2010- 0906 (MEC-FEDER), project EDU2012-33030 of the National Plan for R&D&R (MICIN), Subprogram EDUC, and group FQM-193 of the 3rd Andalusia Research Plan (PAIDI)

Real-time embedded eye detection system

The detection of a person’s eyes is a basic task in applications as important as iris recognition in biometric identification or fatigue detection in driving assistance systems. Current commercial and research systems use software frameworks that require a dedicated computer, whose power consumption, size, and price are significantly large. This paper presents a hardware-based embedded solution for eye detection in real-time. From an algorithmic point-of-view, the popular Viola-Jones approach has been redesigned to enable highly parallel, single-pass image-processing implementation. Synthesized and implemented in an All-Programmable System-on-Chip (AP SoC), this proposal allows us to process more than 88 frames per second (fps), taking the classifier less than 2 ms per image. Experimental validation has been successfully addressed in an iris recognition system that works with walking subjects. In this case, the prototype module includes a CMOS digital imaging sensor providing 16 Mpixels images, and it outputs a stream of detected eyes as 640 × 480 images. Experiments for determining the accuracy of the proposed system in terms of eye detection are performed in the CASIA-Iris-distance V4 database. Significantly, they show that the accuracy in terms of eye detection is 100%.This work has been partially developed within the project RTI2018-099522-B-C4X, funded by the Gobierno de España and FEDER funds, and the ARMORI project (CEIATECH-10) funded by the University of Málaga. Portions of the research in this paper use the CASIA-Iris V4 collected by the Chinese Academy of Sciences - Institute of Automation (CASIA)

La muralla Engel/Paris y la necrópolis protohistórica de Osuna

Durante las excavaciones arqueológicas realizadas en Osuna en el año 1903 por A. Engel y P. París, junto al Camino de San José, se exploró una muralla en una longitud de casi 100 m. que se asentaba sobre una necrópolis. En 1973 R. Corzo continuó las excavaciones en el punto en el que habían sido abandonados los trabajos por los franceses. Tanto éstos como Corzo fijaron su cronología hacia el s. 1 a.C., poniéndola en relación con los acontecimientos narrados en el Bellum Hispaniense. Sin embargo, el análisis de nuevas aportaciones surgidas durante los últimos años lleva a pensar que la datación de este elemento defensivo debe fijarse en un momento anterior. Para su discusión se considerarán tres aspectos, a saber, la técnica constructiva empleada en el muro, su probable época de erección y el valor funerario del sitio.In the archaeological explorations made next to Camino de San Jose in Osuna in 1903 by A. Engel and P. Paris, it was excavated an almost 100m long wall which was situated over a necropolis. In 1973 R. Corzo continued the excavations gave up by Frenchs. According to both Frenchs and Corzo, the wall dates from about 1" BC and it is connected with the events narrated in the Bellum Hispaniense. However, the new contributions appeared in the last years lead us to think this defensive element dates from an earlier time. In order to make sure of that, we are going to consider three aspects: the construction technique used, its probably erection time and the funeral value of the site

Demand and Storage Management in a Prosumer Nanogrid Based on Energy Forecasting

Energy efficiency and consumers' role in the energy system are among the strategic research topics in power systems these days. Smart grids (SG) and, specifically, microgrids, are key tools for these purposes. This paper presents a three-stage strategy for energy management in a prosumer nanogrid. Firstly, energy monitoring is performed and time-space compression is applied as a tool for forecasting energy resources and power quality (PQ) indices; secondly, demand is managed, taking advantage of smart appliances (SA) to reduce the electricity bill; finally, energy storage systems (ESS) are also managed to better match the forecasted generation of each prosumer. Results show how these strategies can be coordinated to contribute to energy management in the prosumer nanogrid. A simulation test is included, which proves how effectively the prosumers' power converters track the power setpoints obtained from the proposed strategy.Spanish Agencia Estatal de Investigacion ; Fondo Europeo de Desarrollo Regional

Exploring the ring-closing metathesis for the construction of the solomonamide macrocyclic core: identification of bioactive precursors

New synthetic strategies directed toward the novel cyclopeptides solomonamides have been explored utilizing an olefin metathesis as the key reaction. In the various strategies investigated, we worked on minimally oxidized systems, and the olefin metathesis reaction demonstrated efficiency and validity for the construction of the macrocyclic core. The described synthetic strategies toward the solomonamides are well suited for the subsequent access to the natural products and represent flexible and diversityoriented routes that allow for the generation of a variety of analogues via oxidative transformations. In addition, preliminary biological evaluations of the generated solomonamide precursors revealed antitumor activity against various tumor cell lines.This work was financially supported by the Ministerio de Economía y Competitividad (MINECO) (ref BIO2014-56092-R, CTQ2014-60223-R and CTQ2016-76311-R) and Junta de Andalucía and “Fondo Europeo de Desarrollo Regional-FEDER” (P12 CTS-1507). I.C.-S. thanks Ministerio de Educación, Cultura y Deporte for a predoctoral fellowship (FPU programme)

Aspectos estructurales y concepciones personales sobre límite finito de una función en un punto de estudiantes de bachillerato

El objeto de este trabajo es describir e interpretar las concepciones personales de un grupo de estudiantes de bachillerato acerca del concepto de límite finito de una función en un punto en términos de aspectos estructurales, compilados y sintetizados a partir de investigaciones previas. Estos aspectos son: la interpretación como objeto o como proceso de la noción de límite, su carácter exacto o aproximado, su consideración como proceso potencialmente infinito o finito en la práctica, su alcanzabilidad y su rebasabilidad. Los estudiantes respondieron a seis cuestiones para valorar la veracidad o falsedad de enunciados relativos a estos aspectos. Basados en estos aspectos, analizamos y tipificamos respuestas obtenidas en perfiles y destacamos la riqueza de relaciones entre los aspectos estructurales descritos, particularmente la vinculación entre la alcanzabilidad y la rebasabilidad.The purpose of this work is to describe and interpret the personal conceptions related to the concept of finite limit of a function at one point from a group of non-compulsory secondary education students in terms of structural aspects, compiled and synthesized from prior research. These aspects are: the interpretation of the limit notion as an object or a process, its exact or approximate character, its consideration as a potentially infinite or finite in practical process, its reachability and its possibility of being exceeded. Students answered six questions to verify the truthfulness or falsity of statements related to these properties. Based on these structural aspects, we analyze and typify the provided responses in profiles, pointing out the richness of relationships between these structural aspects, highlighting the one between reachability and the possibility of being exceeded.Este trabajo ha sido realizado con la ayuda y financiación de la beca FPU (AP2010- 0906), (MEC-FEDER), del proyecto “Modelización y representaciones en educación matemática (EDU2009-11337) del Plan Nacional de I+D+I (MICIN) y del grupo FQM- 193 (Didáctica de la Matemática. Pensamiento Numérico) del 3er Plan Andaluz de Investigación, Desarrollo e Innovación (PAIDI)

Preanalytical errors: the professionals’ perspective

This study was aimed at understanding the perspective on preanalytical errors from the point of view of the professionals involved in the preanalytical process. A significant contribution of their specialized knowledge and experience in day-to-day practice for identifying these kinds of mistakes, and their most frequent causes, was expected.It seems evident that weaknesses and threats are closely related to institutional organization aspects and the same is true for positive elements (strengths and opportunities). There is also an important appreciation of the staff’s implication. Staff´s opinions should be taken into account by institution managers, as they offer an approach that is different and complementary to the one traditionally applied, which is purely managerial and therefore not sufficient. The results should be complemented with more updated information. Multidisciplinary cooperation must involve not only professionals from different fields but also with different roles, i.e., managers, in order to obtain results that can be used to improve healthcare, save costs and to guarantee patient’s safety. We will continue with this research line investigating the same questions among primary care staff, in order to assess “the other side of the coin” of this problem.This study was partially supported by project Fondo de Investigaciones Sanitarias (FIS) grant PIFIS 1099/12 from “Instituto de Salud Carlos III” Ministerio de Sanidad y Política Social. Gobierno de España. (Health Ministry, Spanish Government).Yes2015-04-0

Significados puestos de manifiesto por estudiantes de bachillerato respecto al concepto de límite finito de una función en un punto: estudio exploratorio

Se trata de un estudio exploratorio y descriptivo llevado a cabo con estudiantes del primer curso de bachillerato de un instituto de la provincia de Granada con el objetivo de describir los significados del concepto de límite finito de una función en un punto que ponen de manifiesto al enfrentarse con tareas que vinculan varios sistemas de representación, tanto en formato de respuesta abierta como de elección múltiple cerrada. El instrumento utilizado fue un cuestionario que incluían tareas provenientes de investigaciones previas como propuestas por los investigadores. El análisis de las respuestas abiertas fundamentado en el análisis conceptual previo de los términos claves "aproximar", "tender", "alcanzar", "rebasar" y "límite" que emergen de las respuestas de los estudiantes concluyendo con que los escolares hacen uso de un lenguaje poco elaborado y con persistencia de significados coloquiales informados ya por Cornu, Monaghan y Tall, si bien el apoyo gráfico es un aliciente para una argumentación más fluida y precisa de los escolares. El análisis de las respuestas de elección múltiple refleja la existencia de contradicciones establecidas por los escolares cuando asignan propiedades simbólicas a diferentes tipos de gráficas, de hecho, las frecuencias asociadas a los distintos casos se corresponden con la complejidad que a priori pueden tener dichas gráficas

Low dietary inclusion of nutraceuticals from microalgae improves feed efficiency and modifies intermediary metabolisms in gilthead sea bream (Sparus aurata)

The aim of this work was to evaluate two functional feeds for the gilthead seabream, Sparus aurata, containing low inclusion of two microalgae-based products (LB-GREENboost, LBGb; and LB-GUThealth, LBGh). Fish (12-13 g) were fed for 13 weeks a control diet or one of the four diets supplemented with both products at 0.5% or 1%. LBGb and LBGh did not affect specific growth rate or survival, but increased feed efficiency by decreasing feed intake and enlarging the intestines. LBGb increased hepatosomatic index and reduced cortisol levels in plasma, while both products lowered plasma lactate. Extensive metabolite and metabolic enzyme profiling revealed that microalgae supplementations, especially 1% LBGh: (i) decrease plasma lactate and increase hepatic glycogen, (ii) reduce hepatic gluconeogenesis, (iii) enhance hepatic lipogenic activity and lipid secretion, (iv) led fish to double triglyceride content in muscle and to stimulate its lipid oxidative capacity, and (v) increase the content of monounsaturated fatty acids and the omega-3 alpha-linolenic acid in muscle. This study demonstrates that both microalgae-based products are suited to improve feed efficiency and orchestrate significant changes in the intermediary metabolism in gilthead seabream juveniles

Efficient microwave-assisted production of furfural from C5 sugars in aqueous media catalysed by Bro¨nsted acidic ionic liquids

Small amounts of SO3H-functionalised room temperature synthesized ionic liquids efficiently dehydrate aqueous xylose to furfural under microwave heating at mild reaction conditions. The RT-ionic liquid catalysts were also found to be effective catalysts for the two step one-pot simultaneous hydrolysis and dehydration of a lignocellulosic waste biorefinery-derived syrup enriched in C5 sugar oligomer