Atomismo versus energetismo : controversia científica a finales del siglo XIX

Los aprendizajes sobre la naturaleza atómica de la materia, en los niveles primarios, secundarios y también universitarios, son equívocos, porque están centrados sólo en la evolución de los modelos atómicos a lo largo de la historia, como si desde el origen de los tiempos nadie hubiera puesto en entredicho esa naturaleza corpuscular. Sin embargo, la propia historia fue muy distinta: hasta el primer tercio del siglo XX la comunidad científica no asumió la concepción atómica de la materia, incluso hubo rechazos tan significativos y triunfantes, durante algún tiempo, como el protagonizado por los energetistas. Estas deficiencias son patentes en los libros de texto, en los libros de divulgación científica y en los procesos de enseñanza-aprendizaje desarrollados por el profesorado, en general. A despejar este equívoco pretende contribuir el presente trabajo, en parte expuesto en la conferencia de clausura del VII Congreso Internacional sobre Investigación en la Didáctica de las Ciencias - Educación científi ca para la ciudadanía - celebrado en Granada (7-10/9/2005). La conferencia fue desarrollada mediante comentarios apoyados en sinopsis, gráficas e ilustraciones que no es posible reproducir aquí en su totalidad; de entre lo esencial, he seleccionado aquello que admitía una mejor y fácil reproducción, espero no haber cercenado excesivamente el contenido de la conferencia originaria.Learning on the atomic nature of matter is often equivocal in primary, secondary and universities too, due to the fact that they are focused on the evolution of the diverse atomic models throughout history, as if no one had ever questioned the corpuscular nature at stake. However, history itself developed along rather different paths: the scientific community did not acknowledge the atomic nature of matter until as late as the first third of the 20th century, and, for a while, there were such significant and triumphant rejections as the one led by the energeticists. These shortcomings are conspicuous in textbooks, popular science books and, generally, in the teacher-learning processes developed by teachers. The current paper, partially discussed in the closing lecture at the 7th International Conference of Research on Science Teaching - Science education for citizenship - held in Granada (7-10/09/2005) is intended to illuminate this misunderstanding. The conference was developed with printed and visual support which has not totally been reproduced here; among the essential data, I have selected that which allowed for a better reproduction, hoping not to have cut out excessively the original contents

La formación de los nuevos profesores.

Sin resume

Estrategias farmacológicas en el tratamiento de la adicción por cocaína

Probablemente la cocaína está siendo consumida de forma alarmante debido en parte a la falsa idea de que no iba a producir las devastadoras consecuencias y efectos atribuidos a otras drogas de abuso. Sin embargo, su gran poder adictógeno, dificulta lograr el abandono del consumo y sí plantea graves problemas destacables y efectos secundarios potencialmente vitales.En esta adicción, destaca el polimorfismo de patología psíquica coexistente. Nos limitaremos a conceptuar el tratamiento de la propia adicción y a esquematizarlo al máximo para favorecer la mayor claridad posible, dado que existen numerosos datos, referencias bibliográficas y publicaciones sobre el tema.El progreso en el conocimiento del mecanismo de acción de la cocaína ha abierto una serie de expectativas e investigaciones en un intento de mejorar el más adecuado rendimiento de los tratamientos farmacológicos.Actualmente, el arsenal terapéutico está concebido como una herramienta para ayudar a los pacientes a mantenerse abstinentes en conjunción con otros abordajes de tipos psicoterapéuticos y sociales

Universality on higher order Hardy spaces

We prove a Seidel-Walsh-type theorem about universality of a sequence of derivation-composition operators generated by automorphisms of the unit disk in the setting of the higher order Hardy spaces. Moreover, some related positive or negative assertions involving interpolating sequences and sequences between two tangent circles are established for the class of bounded functions in the unit disk. Our statements improve earlier ones due to Herzog and to the first and third authors.Plan Andaluz de Investigación (Junta de Andalucía)Dirección General de Enseñanza Superior (DGES). EspañaMinisterio de Ciencia y Tecnología (MCYT). EspañaEuropean Commission (EC). Fondo Europeo de Desarrollo Regional (FEDER

Evolutionary computing and particle filtering: a hardware-based motion estimation system

Particle filters constitute themselves a highly powerful estimation tool, especially when dealing with non-linear non-Gaussian systems. However, traditional approaches present several limitations, which reduce significantly their performance. Evolutionary algorithms, and more specifically their optimization capabilities, may be used in order to overcome particle-filtering weaknesses. In this paper, a novel FPGA-based particle filter that takes advantage of evolutionary computation in order to estimate motion patterns is presented. The evolutionary algorithm, which has been included inside the resampling stage, mitigates the known sample impoverishment phenomenon, very common in particle-filtering systems. In addition, a hybrid mutation technique using two different mutation operators, each of them with a specific purpose, is proposed in order to enhance estimation results and make a more robust system. Moreover, implementing the proposed Evolutionary Particle Filter as a hardware accelerator has led to faster processing times than different software implementations of the same algorithm

The DLMT hardware implementation. A comparative study with the DCT and the DWT

In the last recent years, with the popularity of image compression techniques, many architectures have been proposed. Those have been generally based on the Forward and Inverse Discrete Cosine Transform (FDCT, IDCT). Alternatively, compression schemes based on discrete "wavelets" transform (DWT), used, both, in JPEG2000 coding standard and in H264-SVC (Scalable Video Coding) standard, do not need to divide the image into non-overlapping blocks or macroblocks. This paper discusses the DLMT (Discrete Lopez-Moreno Transform) hardware implementation. It proposes a new scheme intermediate between the DCT and the DWT, comparing results of the most relevant proposed architectures for benchmarking. The DLMT can also be applied over a whole image, but this does not involve increasing computational complexity. FPGA implementation results show that the proposed DLMT has significant performance benefits and improvements comparing with the DCT and the DWT and consequently it is very suitable for implementation on WSN (Wireless Sensor Network) applications

The DLMT. An alternative to the DCT

In the last recent years, with the popularity of image compression techniques, many architectures have been proposed. Those have been generally based on the Forward and Inverse Discrete Cosine Transform (FDCT, IDCT). Alternatively, compression schemes based on discrete “wavelets” transform (DWT), used, both, in JPEG2000 coding standard and in the next H264-SVC (Scalable Video Coding), do not need to divide the image into non-overlapping blocks or macroblocks. This paper discusses the DLMT (Discrete Lopez-Moreno Transform). It proposes a new scheme intermediate between the DCT and the DWT (Discrete Wavelet Transform). The DLMT is computationally very similar to the DCT and uses quasi-sinusoidal functions, so the emergence of artifact blocks and their effects have a relative low importance. The use of quasi-sinusoidal functions has allowed achieving a multiresolution control quite close to that obtained by a DWT, but without increasing the computational complexity of the transformation. The DLMT can also be applied over a whole image, but this does not involve increasing computational complexity. Simulation results in MATLAB show that the proposed DLMT has significant performance benefits and improvements comparing with the DC

Structural aspects of the non-uniformly continuous functions and the unbounded functions within C(X)

We prove in this paper that if a metric space supports a real continuous function which is not uniformly continuous then, under appropriate mild assumptions, there exists in fact a plethora of such functions, in both topological and algebraical senses. Corresponding results are also obtained concerning unbounded continuous functions on a non-compact metrizable space.Plan Andaluz de Investigación (Junta de Andalucía)Ministerio de Economía y Competitividad (MINECO). Españ

The physics in the textbooks:a résistent medium to renovation (1845-1900)

The Physics and Chemistry text books used in the secondary and high schools in Spain, imposed by the Government or freely choosen by the teachers, have an evident French influence. The stereotype of these books was spread from the middle of the nineteen century to the end of the century, more or less, in the same way. The structure of the index, and many contents have arrived at today without variations. This condition in the scientific text books suposed a delay in the incorporation of the scientific newnesses. One of the reasons of this delay is in some way produced by the compulsory official programmes.LOS libros de texto de física y química utilizados en la segunda enseñanza en España, impuestos por el Estado o elegidos libremente por los profesores, ya fueran de autores extranjeros o españoles, tienen una evidente influencia francesa, tanto porque los autores lo fueran como por la estructura y contenidos de los libros escritos en castellano y por autores españoles. El estereotipo de libro difundido a mediados del siglo xix por los Institutos de Segunda Enseñanza se mantuvo con pocas variaciones hasta finales de siglo, y en muchos casos no sólo la estructura del indice, que casi idénticamente ha llegado a nuestros días, sino los contenidos mismos, lo que ha supuesto un retraso en la incorporación de novedades científicas. Entre otras explicaciones a este hecho, hay que señalar los escasos cambios introducidos por los responsables educativos en los programas oficiales a que aquellos libros habían de responder

"Pesar" la tierra : test newtoniano y origen de un anacronismo

The measure G, the universal gravitational constant, is attributed to Henry Cavendish. Nevertheless, the intention of the English physicist was to measure the density of the earth, which at that time was necessary in order to decide between different theories about the composition of this planet. G was measured much later. In this article I will try to explain how Cavendish accomplished the famous experiment and what his results were. Likewise, I will consider the problems that can arise in the scientific training of students from maintaining anachronisms such as this