virtX: ein Lehr- und Lernsystem für mobile Röntgengeräte zur Verbesserung der Ausbildung im Strahlenschutz

Hintergrund und Fragestellung: Die durch röntgentechnische Diagnoseverfahren in der Medizin entstehende Strahlenbelastung für Patient und Personal soll laut Strahlenschutzverordnung so gering wie möglich gehalten werden. Um dieses zu erreichen ist ein professioneller und bedachter Umgang mit den Röntgengeräten unabdingbar. Dieses Verhalten kann derzeit jedoch nur theoretisch vermittelt werden, da sich ein Üben mit realer Strahlung von selbst verbietet. Daher stellt sich die Frage wie man die Strahlenschutzausbildung durch eine verbesserte Vermittlung der komplexen Thematik unterstützen kann. Methoden: Das CBT-System (Computer Based Training) virtX, welches das Erlernen der korrekten Handhabung mobiler Röntgengeräte unterstützt, wurde um Aspekte aus dem Bereich des Strahlenschutzes erweitert. Es wurde eine prototypische Visualisierung der entstehenden Streustrahlung sowie die Darstellung des Nutzstrahlenganges integriert. Des Weiteren wurde die Berechnung und Anzeige der virtuellen Einfallsdosis für das durchstrahlte Volumen sowie für den Bereich des Bildverstärkers hinzugefügt. Für die Berechnung und Visualisierung all dieser Komponenten werden die in virtX parametrisierbaren C-Bogen-Einstellungen, z.B. Stellung der Blenden, Positionierung des Röntgengerätes zum durchstrahlten Volumen und Strahlenintensität, herangezogen. Das so erweiterte System wurde auf einem dreitägigen Kurs für OP-Personal mit über 120 Teilnehmern eingesetzt und auf der Basis von Fragebögen evaluiert. Ergebnisse: Von den Teilnehmern gaben 55 einen ausgefüllten Evaluations-Fragebogen ab (Responserate 82%). Das Durchschnittsalter der 39 weiblichen und 15 männlichen Teilnehmer (einer o.A.) lag bei 33±8 Jahren, die Berufserfahrung bei 9,37±7 Jahren. Die Erfahrung mit dem C-Bogen wurde von einem Teilnehmer (2%) mit „Keine oder bisher nur Einführung erhalten“, von acht Teilnehmern (14%) mit „bediene einen C-Bogen gelegentlich“ und von 46 (84%) mit „bediene einen C-Bogen regelmäßig“ angegeben. 45 (92%) der Teilnehmer gaben an, durch die Visualisierung der Streustrahlung etwas Neues zur Vermeidung unnötiger Strahlenbelastung dazugelernt zu haben. Schlussfolgerung: Trotz einer bislang nur prototypischen Visualisierung der Streustrahlung können mit virtX zentrale Aspekte und Verhaltensweisen zur Vermeidung unnötiger Strahlenbelastung erfolgreich vermittelt werden und so Lücken der traditionellen Strahlenschutzausbildung geschlossen werden.

Caractérisation de nouveaux aspects de l’ataxie spastique autosomale récessive de Charlevoix-Saguenay à l’aide d’un procédé d’imagerie: la tomographie par cohérence optique (OCT)

L’Ataxie spastique autosomale récessive de Charlevoix-Saguenay (ARSACS) est un syndrome héréditaire précoce caractérisé par un tableau clinique particulier incluant des anomalies oculaires. Quatorze ARSACS et 36 témoins sains ont été suivis prospectivement durant 20 mois et ont subi différents tests neuro-ophtalmologiques et des mesures par tomographie par cohérence optique. Des augmentations de l’épaisseur moyenne de la couche de fibres nerveuses (mRNFL), de l’épaisseur fovéolaire centrale et de l’épaisseur moyenne du cube maculaire (CAT) ont été mises en évidence chez les ARSACS en comparaison avec les témoins (p<0,0001 à toutes les séances). Une différence cliniquement significative a été observée dans l’évolution au cours du suivi des épaisseurs de la mRNFL et la CAT des ARSACS par rapport aux contrôles (p=0,030, p=0,026 respectivement), et ces paramètres étaient inversement corrélés avec le degré de sévérité de la maladie, suggérant une diminution d’épaisseur de la mRNFL et de la CAT à mesure que progresse la maladie.

Contribuição da ecografia cerebral transfontanelar para a avaliação do crescimento cerebral do recém-nascido pré-termo

Tese de doutoramento, Medicina (Pediatria), Universidade de Lisboa, Faculdade de Medicina, 2013

Machine learning techniques for music information retrieval

Tese de doutoramento, Informática (Engenharia Informática), Universidade de Lisboa, Faculdade de Ciências, 2015

Utilização de folhas de estilo para definir a apresentação de páginas Web

Relatório da Prática de Ensino Supervisionada, Mestrado em Ensino de Informática, Universidade de Lisboa, 2014

Aprendizagem baseada em projetos na consolidação de conceitos de programação de linguagens SCRIPT

Relatório da prática de ensino supervisionada, Mestrado em Ensino de Informática, Universidade de Lisboa, 2014

Uma avaliação do processo de constituição e desenvolvimento de um observatório num agrupamento de escolas

Dissertação de mestrado, Ciências da Educação (Avaliação em Educação), Universidade de Lisboa, Instituto de Educação, 2014

Do ensino da filosofia da ciência no ensino secundário

Relatório da Prática de Ensino Supervisionada, Mestrado em Ensino da Filosofia, Universidade de Lisboa, 2014

Using non-invasive techniques to examine black bear (Ursus americanus) abundance in the North Cascades Ecosystem, Washington State

Thesis (Master's)--University of Washington, 2013

A psicologia da construção da vida : incursões no conceito da adaptabilidade para o estudo da influência parental na construção de carreira em adolescentes

Tese de doutoramento, Psicologia (Psicologia do Desenvolvimento e Aconselhamento de Carreira), Universidade de Lisboa, Faculdade de Psicologia, 2016

Living and dealing with RF impairments in communication transceivers

This paper provides an overview of the sources and effects of the RF impairments limiting and rendering the performance of the future wireless communication transceivers costly as well as hindering their wide-spread use in commercial products. As transmission bandwidths and carrier frequencies increase effect of these impairments worsen. This paper studies and presents analytical evaluations of the performance degradation due to the RF impairments in terms of bit-error-rate and image rejection ratio. The paper also give highlights of the various aspects of the research carried out in mitigating the effects of these impairments primarily in the digital signal processing domain at the baseband as well as providing low-complexity hardware implementations of such algorithms incorporating a number of power and area saving techniques.

Analysis and compensation of RF impairments for next generation multimode GNSS receivers

Global navigation satellite system (GNSS) receivers require solutions that are compact, cheap and low-power, in order to enable their widespread proliferation into consumer products. Furthermore, interoperability of GNSS with non-navigation systems, especially communication systems will gain importance in providing the value added services in a variety of sectors, providing seamless quality of service for users. An important step into the market for Galileo is the timely availability of these hybrid multi-mode terminals for consumer applications. However, receiver architectures that are amenable to high-levels of integration will inevitably suffer from RF impairments hindering their easy widespread use in commercial products. This paper studies and presents analytical evaluations of the performance degradation due to the RF impairments and develops algorithms that can compensate for them in the DSP domain at the base band with complexity-reduced hardware overheads, hence, paving the way for low-power, highly integrated multi-mode GNSS receivers.

Identification of image attributes that are most affected with changes in displayed image size

This paper describes an investigation of changes in image appearance when images are viewed at different image sizes on a high-end LCD device. Two digital image capturing devices of different overall image quality were used for recording identical natural scenes with a variety of pictorial contents. From each capturing device, a total of sixty four captured scenes, including architecture, nature, portraits, still and moving objects and artworks under various illumination conditions and recorded noise level were selected. The test set included some images where camera shake was purposefully introduced. An achromatic version of the image set that contained only lightness information was obtained by processing the captured images in CIELAB space. Rank order experiments were carried out to determine which image attribute(s) were most affected when the displayed image size was altered. These evaluations were carried out for both chromatic and achromatic versions of the stimuli. For the achromatic stimuli, attributes such as contrast, brightness, sharpness and noisiness were rank-ordered by the observers in terms of the degree of change. The same attributes, as well as hue and colourfulness, were investigated for the chromatic versions of the stimuli. Results showed that sharpness and contrast were the two most affected attributes with changes in displayed image size. The ranking of the remaining attributes varied with image content and illumination conditions. Further, experiments were carried out to link original scene content to the attributes that changed mostly with changes in image size.

A fair day's wage? Perceptions of public sector pay

There is a scarcity of evidence pertaining to the general public's perception of public sector pay. Hence, in the present study, 161 women and 149 men were asked to estimate the wages 35 public sector professions should receive annually in the fictitious nation of Maldoria, based on a comparison value of an annual income of T10,000 for general practitioners. Analysis showed that only pilots were given a higher annual income than general practitioners; miners and local government workers were also provided with relatively high annual incomes. By contrast, newscasters were provided with the lowest annual income. Participants' sex did not affect these evaluations, and other demographic variables and public sector-related information of the participants were poor predictors of their evaluations. The implications of this research on public attitudes toward wage determination are discussed, and avenues for further research highlighted.

The continuing popularity of the neighbourhood and neighbourhood governance in the transition from the 'big state' to the 'big society' paradigm

The neighbourhood in both the UK and Europe continues to dominate thinking about the quality of life in local communities, representation and empowerment, and how local services can be delivered most effectively. For several decades a series of centrally funded programmes in neighbour- hood governance have targeted localities suffering deprivation and social exclusion in England. From these much can be learnt about the strengths and limitations of a local approach to achieving multiple objectives.We review the findings of a case study of neighbourhood governance in the City of Westminster and draw on evaluations of two national programmes. In the conclusions we discuss the problems arising from multiple objectives and examine the prospects for neighbourhood governance as the national paradigm moves away from `big state' solutions towards the less-well-defined `big society' approach and the reinvention of `localism'. While the rationale for neighbourhood governance may change, the `neighbourhood' as a site for service delivery and planning remains as important now as in the past.