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

Implementação da comunicação visual e procedimentos de conservação da obra Chemical Abstracts - Uma experiência da divisão de Biblioteca e documentação do conjunto das Químicas/USP

This paper proposes a model for visual communication, conservation, and maintenance of the collection "Chemical Abstracts". It describes the various steps for its implementation and makes considerations about the whole reference work.

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.

Factors Affecting Consumer’s Illicit Purchase of Copyrighted Digital Work

Peer-to-Peer (P2P) technology has revolutionized file exchange activities besides enhancing processing power distribution. As such, this technology which is nowadays made freely available to all internet users also imposes a threat as it enables the illegal distribution of copyrighted digital work. P2P technology continuously evolves in a greater pace than copyright legislation, leading to compatibility gaps between the applicability of copyright law and the illicit file sharing and downloading. Such issues give high incentives to consumers to practise piracy using P2P systems with a low perception of risk towards prosecution, leading to substantial losses for copyright owners. This study focuses on developing insights for content owners on consumer behaviour towards piracy in Finland, where quantitative analyses are assessed using a data set based on a survey conducted by the Helsinki Institute for IT. The research approach investigates the significance of three fundamental areas in relation to evaluate consumer behaviour as: environmental-related factors, innovation-related factors and consumer-related. each of these are integrates concepts derived in previous theoretical models such as the technology acceptance model, theory of reasoned action, theory of planned behaviour, the issue-risk-judgement model and the Hunt & Vitell’s model.

Shout and Act: an Algorithm for Digital Objects Preservation Inspired from Rescue Robots

We adapt the Shout and Act algorithm to Digital Objects Preservation where agents explore file systems looking for digital objects to be preserved (victims). When they find something they “shout” so that agent mates can hear it. The louder the shout, the urgent or most important the finding is. Louder shouts can also refer to closeness. We perform several experiments to show that this system works very scalably, showing that heterogeneous teams of agents outperform homogeneous ones over a wide range of tasks complexity. The target at-risk documents are MS Office documents (including an RTF file) with Excel content or in Excel format. Thus, an interesting conclusion from the experiments is that fewer heterogeneous (varying skills) agents can equal the performance of many homogeneous (combined super-skilled) agents, implying significant performance increases with lower overall cost growth. Our results impact the design of Digital Objects Preservation teams: a properly designed combination of heterogeneous teams is cheaper and more scalable when confronted with uncertain maps of digital objects that need to be preserved. A cost pyramid is proposed for engineers to use for modeling the most effective agent combinations

Análise de ácidos graxos não-esterificados de plasma humano por cromatografia gasosa capilar com injeção sem divisão de fluxo

The aim of the present work was to test the combination of non-esterified fatty acid (NEFA) isolation using fumed silicon dioxide with capillary gas-chromatography (C-GC) with splitless injection for the analysis of NEFAs in human plasma. Injection volume, solvent re-condensation and split purge flow-rate were the parameters evaluated for the analysis of fatty acid methyl esters by C-GC. The use of a solvent re-condensation technique, associated with 1.0 µL injection and a split purge flow rate of 80 mL/min resulted in satisfactory analysis of NEFAs. Fourteen fatty acids were identified in plasma samples, ranging from 2.03 to 184.0 µmol/L. The combination of both techniques proved useful for routine analyses of plasma NEFAs.

Creació d’un Dipòsit Digital d’Activitats Docents amb l’ús de les TIC a la Universitat de Vic

Avui en dia no es poden entendre els canvis socials sense pensar en les conseqüències derivades del nou paradigma digital de comunicació (Castells, 2003). Les Tecnologies de la Informació i la Comunicació (TIC) s’han convertit en eines d’ús quotidià que afecten a tots els àmbits de la vida, des de la gestió del sistema polític, la comunicació a les organitzacions i, també, les noves metodologies d’aprenentatge en les institucions educatives.

Do termoscópio ao termômetro digital: quatro séculos de termometria

This work describes the evolution of temperature measurement in the last four centuries using thermometers based on the thermal expansion of liquids such as ethyl alcohol and mercury. The concept of temperature was strongly dependent on the researcher and there was no systematic temperature scale for universal use. The precursor of the common thermometer was the thermoscope, probably invented at the end of the XVIth century. In the XVIIIth century the instrument was greatly improved and several thermometric scales were proposed some of which have been in use until now. These scales were based on arbitrary points. Mercury and ethyl alcohol were the most employed thermometric fluids. In the XIXth century, the concept of absolute zero was a great advance in this field. The most important contribution during the XXth century was the establishment of international temperature scales. The design of the thermometer has been essentially the same along the last 300 years, but many models were proposed for industrial and research purposes. Its association with the densimeter was of great importance for control of industrial chemical processes and also for teaching purposes in the past. Nowadays, there is a clear tendency to replace mercury-based thermometers by electronic digital models. Thermochemistry is the natural relationship between temperature and chemistry.

De Svante Arrhenius ao peagâmetro digital: 100 anos de medida de acidez

This work describes the establishment of the concept of pH and the evolution of its measurement. The origin of the pH definition can be found in the development of the chemistry of aqueous solutions during the XIXth century. The electrolytic dissociation theory by Svante Arrhenius played a central role. After the proposal of the pH scale by Sörensen, many years were necessary for the acceptance of this new parameter among chemists in general. Its importance was first recognized in biochemistry and related areas. Twenty years after, its importance had been recognized in many industrial and laboratorial practices. The previous methods were based on colorimetric and electrometric methods, but both suffered from many problems. Acceptance of pH in Chemistry was only possible after the development of experimental trustable measurements. The invention of the pH meter was the primordial step.

Digital learner portfolio as a tool for inovating assessment in the European Higher Education Area

The present article comes from a doctoral thesis that turns on digital learner portfolio, which is an innovating methodology from the perspective of European Higher Education Area. First, the educative concept of eportfolio is described in the sense of its procedure and its structure, by means of the technological support of a platform of virtual campus. Second, it is shown the pedagogical model of an eportfolio that adapts subjects with an instrumental character to one organization based on tasks and reflections. This design of virtual learning environment is based on a teaching- learning methodology sustained in the activity of the student, which tries to give support to the management of his or her own process of learning and assessment. Finally, the article illustrates the experience of implementation of the first digital learner portfolios in the University of Barcelona and the Autonomous University of Barcelona, with the objective of reflecting about the pedagogical consequences that this assessment model with technological support has in a traditional higher education institution.

Investigating university students' adaptation to digital learner course portfolio

Digital learner portfolios are of growing importance in higher education as the sector seeks new teaching-learning-assessment methods which promote students" autonomy as managers of their own virtual learning environment. The purpose of this study was to analyse descriptively the undergraduate students" perceptions, attitudes and behaviour when using an eportfolio to support their learning and assessment in practice based courses at two traditional Spanish universities. The participants were 88 students, who were studying through a blended learning mode. Data were collected through questionnaires: a computer experience survey, another which examined the psychological, pedagogical and technological dimensions of eportfolios use. Further, an individual overall reflection was obtained from each student to help gain an understanding of their experiences of using the eportfolio. A mixed-method analysis was applied in order to study the impact of this technological innovation on students and their satisfaction. The results showed that the students had positive opinions and self-efficiency through the eportfolio as a tool to manage their learning and assessment during a semester, especially from the second month of use. However, the expected impact on their learning was not so significant. Nevertheless, the students emphasised that the eportfolio was valuable as a personal developmental learning tool.

Learning in Digital Media: the legacy of McLuhan and his Impact on Formal Education

This paper describes a bibliographic analysis of the vision of Marshal McLuhan and the vision adopted by diverse current authors regarding the use of new interactive learning technologies. The paper also analyzes the transformation that will have to take place in the formal surroundings of education in order to improve their social function. The main points of view and contributions made by diverse authors are discussed. It is important that all actors involved in the educational process take in consideration these contributions in order to be ready for future changes.