4,886 research outputs found
"El Sendajo del Quemao", una cueva artificial en la cuenca de Río Grande (Málaga)
Se da a conocer la primera y por ahora única cueva artificial de la cuenca de río Grande.
Aunque sin materiales asociados, su morfología, con cámara circular y cámara secundaria,
engrosa el repertorio del sur peninsular de este tipo de estructuras funerarias, íntimamente
ligadas al megalitismo.This article describes the first and only man-made cave in the Rio Grande ravine. Although
no associated materials have been found, its morphology, which includes both a circular main
chamber and a secondary chamber, allows its inclusion in the Southern Peninsular funerary
structure repertoire. These structures are intimately linked to the Megalith Period
The concept of finite limit of a function at one point as explained by students of non-compulsory secondary education
We review various educational studies of the mathematical concept of limit of a function at a point that indicate how colloquial uses of the terms “to approach,” “to tend toward,” “to reach,” “to exceed” and “limit” influence students’ conceptions of these terms. We then present the results of an exploratory study of this question performed with Spanish students in non-compulsory secondary education and analyze the responses they provide to justify the truth or falsity of statements related to the different characteristics of the concept of finite limit of a function at a point when they use these terms. Finally, we organize their answers according to the kinds of arguments made. Using the response profiles detected, we discuss the influence of everyday usage on the students’ arguments
The NADPH-Dependent thioredoxin reductase C-2-Cys peroxiredoxin redox system modulates the activity of thioredoxin x in arabidopsis chloroplasts
The chloroplast redox network is composed of a complex set of thioredoxins (Trxs), reduced by ferredoxin (Fdx) via a Fdx-dependent Trx reductase (FTR), and an NADPH-dependent Trx reductase with a joint Trx domain, NTRC, which efficiently reduces 2-Cys peroxiredoxins (2-Cys Prxs). Recently, it was proposed that the redox balance of 2-Cys Prxs maintains the redox state of f-type Trxs, thus allowing the proper redox regulation of Calvin-Benson cycle enzymes such as fructose 1,6-bisphosphatase (FBPase). Here, we have addressed whether the action of 2-Cys Prxs is also exerted on Trx x. To that end, an Arabidopsis thaliana quadruple mutant, ntrc-trxx-δ "2cp, which is knocked out for NTRC and Trx x, and contains severely decreased levels of 2-Cys Prxs, was generated. In contrast to ntrc-trxx, which showed a severe growth inhibition phenotype and poor photosynthetic performance, the ntrc-trxx-δ "2cp mutant showed a significant recovery of growth rate and photosynthetic efficiency, indicating that the content of 2-Cys Prxs is critical for the performance of plants lacking both NTRC and Trx x. Light-dependent reduction of FBPase was severely impaired in mutant plants lacking NTRC or NTRC plus Trx x, despite the fact that neither NTRC nor Trx x is an effective reductant of this enzyme. However, FBPase reduction was recovered in the ntrc-trxx-δ "2cp mutant. Our results show that the redox balance of 2-Cys Prxs, which is mostly dependent on NTRC, modulates the activity of Trx x in a similar way as f-type Trxs, thus suggesting that the activity of these Trxs is highly interconnected.Ministerio de Economía y Competitividad BIO2017-85195-C2-1-
Jewelry from the Phoenician necropolises of Málaga
En este artículo se estudian las piezas de oro procedentes de los enterramientos fenicios de Málaga, la mayor parte de las cuales pueden datarse en el siglo VI a. C. Así mismo, se valora la posible existencia en este asentamiento de un taller que, junto a sus lógicas similitudes con otras piezas fenicias del Mediterráneo central y occidental, parece mostrar ciertas peculiaridades formales y decorativas.We study the golden objects from the Phoenician burials from Malaga. The most of them can be dated at VI century b. C. At the same time we value the possible existence in this site of a workshop that, with his logical parallelism with another Phoenicians pieces from central and western Mediterranean, it seem. To show some formals and decorative details
Anthropometric measures as predictive indicators of metabolic risk in a population of “holy week costaleros”
Preventive measures are a priority in those groups that perform intense physical efforts without physical preparation and that can also be overweight or obese. One of the groups that reflect these characteristics is the costaleros of the Holy Week of Andalusia, Spain. This paper aims to describe the effect of obesity on blood pressure. A descriptive cross-sectional study was conducted on 101 costaleros. The anthropometric measures were determined through segmental impedance. Cardiac
recovery and anaerobic power were measured through the Ruffier–Dickson test and the Abalakov test, respectively. Blood pressure was measured when the individuals were at rest. The Kruskal–Wallis test was applied for of continuous parameters and the X2 test for dichotomous measures. Binary logistic regression models were used for the subsequent analysis with R-square and Receiver Operating Characteristic (ROC) curves. The average population was 28 years of age, 173.7 cm tall, and 82.59 Kg weigh. The excess of body fat was 11.27 Kg and Body Mass Index was 27.33 Kg/m2. 72.3% showed abnormal blood pressure and 68.2% were overweight. 32.7% had a waist-hip ratio higher than 0.94. The probability of presenting abnormal blood pressure was higher among the subjects whose fat content was higher and muscle content was lower
Spanish university assessment practices: examination tradition with diversity by faculty.
Classroom assessment is crucial to understand how students approach course materials, even more in a competitive environment such as the one in higher education. Our aim was to explore the current situation of assessment in higher education to consider further institutional and training actions. Every syllabus from all public universities in Spain was entered into a database, from which 1,693 syllabi were selected completely at random for a content analysis. It was found that (1) university teachers use a greater variety and number of assessment instruments than did their counterparts of decades ago, (2) final exam score is still the highest-weighted source of information for the final grade, (3) the cluster of assessment practices show that traditional approaches are still the most prevalent ones, (4) formal peer and self-assessment practices are still extremely rare in the classroom, (5) assessment practices barely change between first- and fourth-year courses, and (6) most variations in assessment are explained by differences on faculty/academic divisions. This research has implications for European legislation, university regulation and university teacher training programmes.pre-print1061 K
Análisis de tareas de cálculo de límites en un punto en las que intervienen identidades notables
Una de las dificultades identificadas en las investigaciones en Pensamiento Matemático Avanzado es la ruptura con el pensamiento algebraico y sus procedimientos. El análisis se apoya continuamente en habilidades algebraicas pero, al mismo tiempo, para conseguir dominar el pensamiento analítico se requiere alejarse del algebraico y tomar conciencia de las diferencias que se establecen entre ellos. En este trabajo se analiza la relación entre los aspectos estructurales y los errores que los estudiantes manifiestan cuando realizan tareas en las que se involucran identidades notables y los errores que
los estudiantes manifiestan cuando calculan límites finitos de funciones en un punto, que corresponden a indeterminaciones del tipo 0/0 y, que se pueden resolver mediante la simplificación de fracciones algebraicas en las que aparecen identidades notables
Videojuegos y cultura de masas: Un estudio del fenómeno Fortnite
Desde los años 70 hasta la actualidad, el sector de los videojuegos ha dado un giro de 180º y se ha situado como una parte muy importante de la industria tecnológica. Los avances de hardware y software han permitido a este sector progresar a pasos agigantados. En cuanto a su posición como forma de cultura, en los últimos tiempos está ganando terreno y se sitúa como un producto cultural muy demandado y cada vez más aceptado desde su nacimiento en los años 70.
Este trabajo se ha acercado a un fenómeno actual que carece de muchos precedentes en el sector de los videojuegos. Un juego como Fortnite ha conseguido poner patas arriba la industria del videojuego y ha logrado enganchar a varias generaciones, además de copar plataformas como YouTube y Twitch de sus contenidos o ser incluido en multitud de medios de comunicación.
A través de una metodología mixta, con un análisis de contenido y una entrevista, se ha buscado un acercamiento completo a un campo poco estudiado y a un fenómeno actual e impredecible. Se ha intentado definir y observar la magnitud de Fortnite unido a las nuevas tecnologías y a nuevas formas de entretenimiento como los e-sports además de intentar descubrir el porqué de ese éxito.
Las conclusiones muestran en gran medida la existencia de un fenómeno global como es Fortnite y la importancia que han tenido plataformas como YouTube y Twitch para su desarrollo, además del buen hacer de la empresa desarrolladora: Epic Games. También se observa cómo ha conseguido en tiempo récord hacerse con el control de la mayoría del contenido audiovisual relacionado con videojuegos.Universidad de Sevilla. Grado en Publicidad y Relaciones Pública
Implantación RCM en grúas pórtico
El proyecto que a continuación se detalla tiene como objeto la mejora de los planes de mantenimiento de las grúas pórtico tipo cigüeña de la Dársena de Cartagena pertenecientes a la factoría de Navantia, como consecuencia de la mejora de los planes de mantenimiento se pretende conseguir una optimización de los procesos de mantenimiento y por tanto una mayor disponibilidad operativa de los equipos, del mismo modo se pretende cumplir los objetivos marcados en las directrices generales de la política de mantenimiento tanto a nivel de Factoría como a nivel corporativo.Escuela Técnica Superior de Ingeniería IndustrialUniversidad Politécnica de Cartagen
The citation merit of scientific publications
We propose a new method to assess the merit of any set of scientific papers in a given field based on the citations they
receive. Given a field and a citation impact indicator, such as the mean citation or the h-index, the merit of a given set of n
articles is identified with the probability that a randomly drawn set of n articles from a given pool of articles in that field has
a lower citation impact according to the indicator in question. The method allows for comparisons between sets of articles
of different sizes and fields. Using a dataset acquired from Thomson Scientific that contains the articles published in the
periodical literature in the period 1998–2007, we show that the novel approach yields rankings of research units different
from those obtained by a direct application of the mean citation or the h-index.The authors acknowledge financial support from the Santander Universities Global Division of Banco Santander. JR-C also acknowledges financial help
from the Spanish MEC (Ministerio de Educación) through grant SEJ2007-67436. JAC and IO-O also acknowledge financial help from the Spanish MEC through
grant ECO2010-19596. This paper is produced as part of the project Science, Innovation, Firms and markets in a Globalised World (SCIFI-GLOW), a Collaborative
Project funded by the European Commission’s Seventh Research Framework Programme, Contract number SSH7-CT-2008-217436
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