Neue klinische Anwendungen der dreidimensionalen Rekonstruktion in der echographischen Diagnostik

Zusammenfassung.   Die Verwendung der Ultraschalltechnik als bildgebendes Verfahren geh?rt in den unterschiedlichsten Bereichen der Medizin zur klinischen Routine. In den letzten Jahren sind sowohl bei der Weiterentwicklung der Echoscanner selbst als auch auf der Softwareseite im Bereich der computer-gestützten Auswertung von Ultraschalldaten enorme Fortschritte erzielt worden. Die Ergebnisse der T?tigkeiten im Sonderforschungsbereich 414 “Rechner- und sensorgestützte Chirurgie” sind bedeutsame Beispiele der Fortschritte in der klinischen Anwendung in unterschiedlichen medizinischen Fachrichtungen. Wir zeigen ein Beispiel aus der 3D-Echographie (Diagnose von Knochentumoren und ihren Auswirkungen auf das umgebende Weichgewebe) und zwei Beispiele aus der Echokardiographie (Vermessung von Herzklappenringen und Diagnose von Herzklappeninsuffizienzen durch Volumetrie und Visualisierung). Die echokardiographischen Anwendungen unterscheiden sich dabei hinsichtlich der verwendeten Ultraschallinformation. W?hrend für die Vermessung von Herzklappenringen die morphologische Information aus den Backscatterdaten gewonnen wird, wird bei der Bestimmung von Flu?volumen auf die Dopplerdaten zurückgegriffen. Eingegangen am 11. Juli 1998 / Angenommen am 12. Januar 1999     

Day-level sedentary pattern estimates derived from hip-worn accelerometer cut-points in 8–12-year-olds: Do they reflect postural transitions?

Improving sedentary measurement is critical to understanding sedentary-health associations in youth. This study assessed agreement between the thigh-worn activPAL and commonly used hip-worn ActiGraph accelerometer methods for assessing sedentary patterns in children. Both devices were worn by 8–12-year-olds (N = 195) for 4.6 ± 1.9 days. Two ActiGraph cut-points were applied to two epoch durations: ≤25 counts (c)/15 s, ≤75c/15s, ≤100c/60s, and ≤300c/60s. Bias, mean absolute deviation (MAD), and intraclass correlation coefficients (ICCs) tested agreement between devices for total sedentary time and 11 sedentary pattern variables (usual bout duration, sedentary time accumulated in various bout durations, breaks/day, break rate, and alpha). For most sedentary pattern variables, ActiGraph 25c/15s, 75c/15s, and 100c/60s had poor ICCs, with bias and MAD >20%. ActiGraph 300c/60s had a better agreement than the other cut-points, but all ICCs were <0.587. ActiGraph underestimated sedentary time in longer bouts and usual bout duration, and overestimated sedentary time in shorter bouts, breaks/day, and alpha. For total sedentary time, ActiGraph 25c/15s, 300c/60s, and 75c/15s had good/fair ICCs, with bias and MAD <20%. Sedentary patterns derived from two commonly used ActiGraph cut-points did not appear to reflect postural changes. These differences between measurement devices should be considered when interpreting findings from sedentary pattern studies.     

Access to Educational and Instructional Computer Technologies for Post‐secondary Students with Disabilities: lessons from three empirical studies

Access issues based on three Canadian empirical studies of the use of computer and information technologies by college and university students with physical, sensory, and learning disabilities are presented. Data were obtained between fall 1997 and spring 1999 from: (1) focus groups with students with disabilities (n = 12); (2) structured interviews with students with disabilities (a = 37) and with post‐secondary personnel responsible for providing services to them (n = 30); (3) questionnaires completed by post‐secondary students with disabilities (n= 725). Findings indicate that the overwhelming majority of students with disabilities use computers and the Internet, but that 41 % of them need some type of adaptation to use computers effectively. Key findings emphasize advantages of computer technologies and delineate barriers to full access. Types of computer, information and adaptive technologies used by students with different disabilities are presented and emerging trends are highlighted. The goal is (1) to sensitize educational and instructional technologists, professors and planners involved in the implementation of educational media into post‐secondary education curricula and (2) to demonstrate that designing for accessibility from the outset creates a more equitable learning environment that provides opportunities for all students     

When arts and crafts education meets Fascism: the Friuli mosaic school, 1922-1943

This paper examines the early history of the Friuli Mosaic School (FMS), an Italian arts and crafts school specialising in mosaic and terrazzo. The history of the FMS opens up a rare window into an often-overlooked field in the history of education: arts and crafts schools in Fascist Italy (1922–1943). Then, the FMS excelled in mosaic education and production and gained the trust of the regime, which notably commissioned the school to produce large mosaic works for the Foro Italico sports complex in Rome. Yet, as this paper contends, the FMS–Fascist Italy relationship was primarily functional rather than political. Similarly, the FMS adopted a pragmatic approach in times of economic hardship by becoming an active agent for its students and alumni who were compelled to emigrate. The migrant trajectory of alumnus Ettore Lorenzini to the United States was paradigmatic of this.     

Differences in Effectiveness Between Primary Schools and their Impact on Secondary School Recommendations

In school effectiveness research differences between schools are mainly expressed in percentages of the variance in cognitive test scores. This article focuses on the impact these differences in effectiveness have on the school career of pupils. The analyses were executed on the data of a school effectiveness study carried out in 1987 and 1988. Two groups of outlier primary schools were selected. The pupils were divided into four categories based on their IQ-score, and into four categories based on their SES-score. Four dependent variables were used: test scores on language, test scores on mathematics, expectations for the follow-up secondary school type based on these test scores, and the actual secondary school recommendation given by the teacher. For all groups of pupils the average scores on mathematics, language and the total standard test score differ significantly for both low- and high-effective schools. The actual recommendation for type of secondary education does not differ significantly. This leads to the conclusion that the recommendations given to the other pupils in the same grade seem to be important; schools tend to recommend a secondary school type according to a normal distribution. High-effective schools tend to recommend beneath, while low-effective schools tend to advise above the expectations.     

Conceptual and empirical differences among various value-added models for accountability

Accountability systems in education generally include indicators of student performance. However, these indicators often differ considerably among the various systems. More and more countries try to include value-added measures, mainly because they do not want to hold schools accountable for differences in their initial intake of students. This study presents a conceptual framework of these value-added measures, resulting in an overview of 5 different types. Using data from Dutch secondary schools, we empirically provide estimates of these different measures. Our analyses show that the correlation between the different types of school effects estimated is rather high, but that the different models implicate different results for individual schools. Based on theoretical considerations, arguments are given to use the following indicators in the value-added accountability models: prior achievement, student-level background characteristics, and compositional characteristics of the student population.     

Networking From the Inside Out: Understanding Learners' Processes,Activities, and Experiences

Research to date has demonstrated that networking can be an effective strategy for supporting meaningful learning. However, studies have shown that learners encounter difficulties using it. In an attempt to understand and thus reduce these difficulties, this study examined learners' underlying cognitive processes and activities while networking. Detailed process, observational, and post-activity interview data were gathered on 14 participants during and after their networking of an 800-word text. The study showed that learners must possess several forms of prior knowledge, and devote appropriate time and effort in order to derive benefits from networking. The instructional implications of the process and the methodological contribution of this study are discussed.     

Supporting the Learning Process with Collaborative Concept Mapping Using Computer-Based Communication Tools and Processes

University students are too often challenged by their limited skills in application, investigation, relational thinking, and communication of ideas. In this study, we have combined 3 tools that potentially can support and foster students’ development in the above mentioned areas through student collaboration, concept mapping, and electronic technologies. The participants in this study were 26 students in two intact classes in learning theories. In groups of 3 to 5 students, they were asked to generate 3 concept maps and accompanying prose over the term on 3 major issues in the field of learning. Through the use of interviews, questionnaires, and student generated concept maps, students reportedly enjoyed concept mapping for its organizational and relational properties but preferred sharing their concept maps and dialoguing with one another in a synchronous mode where immediate feedback and flow of thinking could be maintained when involved in constructing maps. Moreover, they did not like the redundancy offered by both prose and concept map outputs, suggesting that while concept mapping can be an arena for generating and generally structuring ideas, prose can be a means of communicating such ideas in a form that is common to most people. This is particularly important for teachers and students who have difficulty navigating through maps alone.