Reliability of digital panoramic radiography in the diagnosis of carotid artery calcifications

Objective The present study evaluated the reliability of digital panoramic radiography in the diagnosis of carotid artery calcifications. Materials and Methods Thirty-five patients under high-risk for development of carotid artery calcifications who had digital panoramic radiography were referred to undergo ultrasonography. Thus, 70 arteries were assessed by both methods. The main parameters utilized to evaluate the panoramic radiography reliability in the diagnosis of carotid artery calcifications were accuracy, sensitivity, specificity and positive predictive value of this method as compared with ultrasonography. Additionally, the McNemar's test was utilized to verify whether there was a statistically significant difference between digital panoramic radiography and ultrasonography. Results Ultrasonography demonstrated carotid artery calcifications in 17 (48.57%) patients. Such individuals presented with a total of 29 (41.43%) carotid arteries affected by calcification. Radiography was accurate in 71.43% (n = 50) of cases evaluated. The degree of sensitivity of this method was 37.93%, specificity of 95.12% and positive predictive value of 84.61%. A statistically significant difference (p < 0.001) was observed between the methods evaluated in their capacity to diagnose carotid artery calcifications. Conclusion Digital panoramic radiography should not be indicated as a method of choice in the investigation of carotid artery calcifications.

Lessons from the Digital Divide

Peer-reviewed

Evaluación del estado del arte en relación con la temática, las plataformas y la experiencia del usuario: El documental interactivo en la estrategia de la multidifusión digital

This article argues that interactive documentaries play a key role in digital multicasting strategies the author offers analysis of the latest trends in this area from three angles: the documentery subject, the support/ platform, and the user experience.

A Social Network Analysis of Twitter: Mapping the Digital Humanities Community

Defining digital humanities might be an endless debate if we stick to the discussion about the boundaries of this concept as an academic "discipline". In an attempt to concretely identify this field and its actors, this paper shows that it is possible to analyse them through Twitter, a social media widely used by this "community of practice". Based on a network analysis of 2,500 users identified as members of this movement, the visualisation of the "who's following who?" graph allows us to highlight the structure of the network's relationships, and identify users whose position is particular. Specifically, we show that linguistic groups are key factors to explain clustering within a network whose characteristics look similar to a small world.

Monte Carlo derivation of filtered tungsten anode X-ray spectra for dose computation in digital mammography

Abstract Objective: Derive filtered tungsten X-ray spectra used in digital mammography systems by means of Monte Carlo simulations. Materials and Methods: Filtered spectra for rhodium filter were obtained for tube potentials between 26 and 32 kV. The half-value layer (HVL) of simulated filtered spectra were compared with those obtained experimentally with a solid state detector Unfors model 8202031-H Xi R/F & MAM Detector Platinum and 8201023-C Xi Base unit Platinum Plus w mAs in a Hologic Selenia Dimensions system using a direct radiography mode. Results: Calculated HVL values showed good agreement as compared with those obtained experimentally. The greatest relative difference between the Monte Carlo calculated HVL values and experimental HVL values was 4%. Conclusion: The results show that the filtered tungsten anode X-ray spectra and the EGSnrc Monte Carlo code can be used for mean glandular dose determination in mammography.

Prensa digital y bibliotecas

Quince años después de la aparición de los primeros diarios en Internet, los medios de comunicación en general y la prensa en particular se encuentran inmersos en una situación singularmente crítica, incierta y desconcertante. En estos momentos de cambios profundos se mezclan amenazas y oportunidades en un cóctel aún incierto del cual no se sabe muy bien qué surgirá.Las amenazas provienen de la crisis de la prensa escrita, acuciada por la pérdida de lectores y el descenso de la publicidad, por la aparición de nuevos agentes informativos y por las dudas sobre el papel mediador del periodista.La crisis económica, iniciada con virulencia en los últimos meses del 2008, provocó entre otros efectos una drástica reducción de las inversiones de las empresas e instituciones en publicidad en medios, hecho que ataca frontalmente el modelo de negocio de los diarios. Al agudo golpe acusado en la reducción de ingresos publicitarios, se superpone un cambio cultural de gran calado en los hábitos de consumo de noticias, que se va abriendo paso a medida que las nuevas (y no tan nuevas) generaciones de lectores dejan de comprar diarios en papel (o reducen su consumo) para leer las informaciones de actualidad directamente en Internet.Además, las informaciones de actualidad ahora ya no solamente las ofrecen las cabeceras en línea de los medios de comunicación convencionales, sino también una variada oferta de productos y servicios: agregadores, blogs, webs sociales, redes sociales, twitter, etcétera, con lo cual la hegemonía informativa de la que disfrutaban los medios de comunicación de masas en la época «analógica», se difumina en el entorno digital y a la vez también se debilita el papel del periodista como mediador entre la realidad y la audiencia. De esta forma se constata que los cambios no son tan solo económicos, sino que afectan también a la esencia de la función de la prensa y de los periodistas...

Student Journalism 2.0 : Testing Models for Participatory Learning in the Digital Age

Many educators and educational institutions have yet to integrate web-based practices into their classrooms and curricula. As a result, it can be difficult to prototype and evaluate approaches to transforming classrooms from static endpoints to dynamic, content-creating nodes in the online information ecosystem. But many scholastic journalism programs have already embraced the capabilities of the Internet for virtual collaboration, dissemination, and reader participation. Because of this, scholastic journalism can act as a test-bed for integrating web-based sharing and collaboration practices into classrooms. Student Journalism 2.0 was a research project to integrate open copyright licenses into two scholastic journalism programs, to document outcomes, and to identify recommendations and remaining challenges for similar integrations. Video and audio recordings of two participating high school journalism programs informed the research. In describing the steps of our integration process, we note some important legal, technical, and social challenges. Legal worries such as uncertainty over copyright ownership could lead districts and administrators to disallow open licensing of student work. Publication platforms among journalism classrooms are far from standardized, making any integration of new technologies and practices difficult to achieve at scale. And teachers and students face challenges re-conceptualizing the role their class work can play online.

Towards personalization in digital libraries through ontologies

In this paper we describe a browsing and searching personalization system for digitallibraries based on the use of ontologies for describing the relationships between all theelements which take part in a digital library scenario of use. The main goal of thisproject is to help the users of a digital library to improve their experience of use bymeans of two complementary strategies: first, by maintaining a complete history recordof his or her browsing and searching activities, which is part of a navigational userprofile which includes preferences and all the aspects related to community involvement; and second, by reusing all the knowledge which has been extracted from previous usage from other users with similar profiles. This can be accomplished in terms of narrowing and focusing the search results and browsing options through the use of a recommendation system which organizes such results in the most appropriatemanner, using ontologies and concepts drawn from the semantic web field. The complete integration of the experience of use of a digital library in the learning process is also pursued. Both the usage and information organization can be also exploited to extract useful knowledge from the way users interact with a digital library, knowledge that can be used to improve several design aspects of the library, ranging from internal organization aspects to human factors and user interfaces. Although this project is still on an early development stage, it is possible to identify all the desired functionalities and requirements that are necessary to fully integrate the use of a digital library in an e-learning environment.

Enriching e-learning metadata through digital library usage analysis

Peer-reviewed

The effects of ICT on school: teachers’ and students’ perspectives

The purpose of this study was to investigate the effects of information and communication technology (ICT) on school from teachers’ and students’ perspectives. The focus was on three main subject matters: on ICT use and competence, on teacher and school community, and on learning environment and teaching practices. The study is closely connected to the national educational policy which has aimed strongly at supporting the implementation of ICT in pedagogical practices at all institutional levels. The phenomena were investigated using a mixed methods approach. The qualitative data from three cases studies and the quantitative data from three statistical studies were combined. In this study, mixed methods were used to investigate the complex phenomena from various stakeholders’ points of view, and to support validation by combining different perspectives in order to give a fuller and more complete picture of the phenomena. The data were used in a complementary manner. The results indicate that the technical resources for using ICT both at school and at homes are very good. In general, students are capable and motivated users of new technology; these skills and attitudes are mainly based on home resources and leisuretime use. Students have the skills to use new kinds of applications and new forms of technology, and their ICT skills are wide, although not necessarily adequate; the working habits might be ineffective and even wrong. Some students have a special kind of ICT-related adaptive expertise which develops in a beneficial interaction between school guidance and challenges, and individual interest and activity. Teachers’ skills are more heterogeneous. The large majority of teachers have sufficient skills for everyday and routine working practices, but many of them still have difficulties in finding a meaningful pedagogical use for technology. The intensive case study indicated that for the majority of teachers the intensive ICT projects offer a possibility for learning new skills and competences intertwined in the work, often also supported by external experts and a collaborative teacher community; a possibility that “ordinary” teachers usually do not have. Further, teachers’ good ICT competence help them to adopt new pedagogical practices and integrate ICT in a meaningful way. The genders differ in their use of and skills in ICT: males show better skills especially in purely technical issues also in schools and classrooms, whereas female students and younger female teachers use ICT in their ordinary practices quite naturally. With time, the technology has become less technical and its communication and creation affordances have become stronger, easier to use, more popular and motivating, all of which has increased female interest in the technology. There is a generation gap in ICT use and competence between teachers and students. This is apparent especially in the ICT-related pedagogical practices in the majority of schools. The new digital affordances not only replace some previous practices; the new functionalities change many of our existing conceptions, values, attitudes and practices. The very different conceptions that generations have about technology leads, in the worst case, to a digital gap in education; the technology used in school is boring and ineffective compared to the ICT use outside school, and it does not provide the competence needed for using advanced technology in learning. The results indicate that in schools which have special ICT projects (“ICT pilot schools”) for improving pedagogy, these have led to true changes in teaching practices. Many teachers adopted student-centred and collaborative, inquiry-oriented teaching practices as well as practices that supported students' authentic activities, independent work, knowledge building, and students' responsibility. This is, indeed, strongly dependent on the ICT-related pedagogical competence of the teacher. However, the daily practices of some teachers still reflected a rather traditional teacher-centred approach. As a matter of fact, very few teachers ever represented solely, e.g. the knowledge building approach; teachers used various approaches or mixed them, based on the situation, teaching and learning goals, and on their pedagogical and technical competence. In general, changes towards pedagogical improvements even in wellorganised developmental projects are slow. As a result, there are two kinds of ICT stories: successful “ICT pilot schools” with pedagogical innovations related to ICT and with school community level agreement about the visions and aims, and “ordinary schools”, which have no particular interest in or external support for using ICT for improvement, and in which ICT is used in a more routine way, and as a tool for individual teachers, not for the school community.

Microcalcification evaluation in computer assisted diagnosis for digital mammography

In order to develop applications for z;isual interpretation of medical images, the early detection and evaluation of microcalcifications in digital mammograms is verg important since their presence is oftenassociated with a high incidence of breast cancers. Accurate classification into benign and malignant groups would help improve diagnostic sensitivity as well as reduce the number of unnecessa y biopsies. The challenge here is the selection of the useful features to distinguish benign from malignant micro calcifications. Our purpose in this work is to analyse a microcalcification evaluation method based on a set of shapebased features extracted from the digitised mammography. The segmentation of the microcalcificationsis performed using a fixed-tolerance region growing method to extract boundaries of calcifications with manually selected seed pixels. Taking into account that shapes and sizes of clustered microcalcificationshave been associated with a high risk of carcinoma based on digerent subjective measures, such as whether or not the calcifications are irregular, linear, vermiform, branched, rounded or ring like, our efforts were addressed to obtain a feature set related to the shape. The identification of the pammeters concerning the malignant character of the microcalcifications was performed on a set of 146 mammograms with their real diagnosis known in advance from biopsies. This allowed identifying the following shape-based parameters as the relevant ones: Number of clusters, Number of holes, Area, Feret elongation, Roughness, and Elongation. Further experiments on a set of 70 new mammogmms showed that the performance of the classification scheme is close to the mean performance of three expert radiologists, which allows to consider the proposed method for assisting the diagnosis and encourages to continue the investigation in the senseof adding new features not only related to the shape

Estudi i disseny d'un sistema de modificació tímbrica en instruments determinats a través d'anàlisi, filtratge i síntesi de senyal d'àudio digital

Aquest treball final de carrera sorgeix doncs d'una idea molt ambiciosa: crear un sistema de processat de senyal digital que permetés, a temps real, convertir un timbre d'un instrument determinat a un altre, és a dir, a través d'un micròfon que capti el so d'un instrument, com ara el clarinet, analitzar i processar mitjançant programari d'ordinador aquest so d'entrada. Conseqüentment, convertir-lo per poder percebre'l a través dels altaveus com a so d'un altre instrument. D'aquesta manera, un músic amb habilitats per tocar el clarinet, mitjançant aquesta eina podria simular so de saxo, trompeta, etc., sense haver de recórrer a un sintetitzador ni a altres instruments MIDI.

Propuestas pedagógicas para la introducción de la educación para el desarrollo en las enseñanzas científico-técnicas (edición digital)

Peer Reviewed

LUDOLITERACY Informe sobre la alfabetización mediática en el juego digital. Experiencias en Europa

El informe que a continuación presentamos recoge 18 experiencias, proyectos, actividades,investigaciones o políticas más significativas que se realizan en Europa relacionadas con la alfabetización mediática en el contexto de los videojuegos (ludoliteracy). La ludoliteracy tiene como finalidad potenciar las capacidades y competencias analíticas, reflexivas y creativas alrededor del juego digital. Se trata, en conjunto, de propuestas que permiten al ciudadano (joven o adulto, profesional o usuario) y a la sociedad en general ser más conscientes de nuestros propios placeres, tener capacidad crítica y competencia creativa en el campo específico de los juegos digitales.El objetivo final del informe es ofrecer recomendaciones en un campo socialmente controvertido y económicamente situado a la cabeza de las industrias culturales pero institucionalmente emplazado en los márgenes de las políticas educativas estatales y europeas.

La Fractura digital

La Brecha Digital. Según la OECD, en su 'Understanding Digital Divide' 2001, el término de Brecha Digital se refiere a las diferencias entre los individuos, hogares, empresas y áreas geográficas en los diferentes niveles socioeconómicos en relación con sus posibilidades de acceso a la información y a la comunicación (TIC) y su uso con internet para una gran variedad de actividades.