DNA-Computing – ein funktionales Modell im laborpraktischen Experiment

Zusammenfassung.   Im Zentrum der Betrachtungen zum DNA-Computing steht die Frage nach den Chancen und Grenzen dieses neuen Berechnungsmodells, nachdem in den letzten Jahren eine rasante Entwicklung auf das Thema aufmerksam machte. Neben beachtlichen theoretischen Untersuchungen zum “Rechnen im Reagenzglas” werden auch laborpraktische Implementierungen favorisiert. An der TU Dresden wurde in interdisziplin?rer Arbeit ein Integer-Rucksackproblem mittels eines DNA-Algorithmus im Labor gel?st und dabei eine Vielzahl molekularbiologischer Operationen analysiert. Mit Hilfe dieses Satzes von Operationen gelang eine universelle und labornahe Modellierung des DNA-Computing. Hierbei angewandte Techniken und Methoden werden vorgestellt und bewertet. Die Beschreibung des DNA-Algorithmus zeigt, wie sich Einzeloperationen vorteilhaft zu Operationsfolgen zusammensetzen lassen und gemeinsam mit einer geeigneten DNA-Kodierung der Eingangsdaten zur L?sung des Problems im Labor führen. Erstmalig wurden hierbei natürliche Zahlen verarbeitet. Die Arbeitsgemeinschaft DNA-Computing Dresden konzentriert sich auf Aufgabenstellungen, die formale Modelle des DNA-Computing mit überzeugenden Laborimplementierungen verbinden. Eingegangen am 14. Februar 2000 / Angenommen am 26. Oktober 2000     

Restructuring reforms in Turkish teacher education: Modernisation and development in a dynamic environment

The paper examines the effectiveness of recent reforms in teacher education in Turkey, specifically the restructuring of programmes in university faculties of education. It first, briefly, sets the reforms of the 1990s in an historical context, prior to the 1997 Act which increased the length of compulsory schooling from 5 to 8 years, and the 1998 restructuring of faculties of education. It considers the national need for the restructuring of teacher education and the issues involved. The thrust of the paper is a study of how teacher educators across the country perceive both the changes and their effect on the quality of teacher education, methodology as a discipline, school partnerships, and relationships with the Ministry of National Education.     

Hematological Parameters and RBC TBARS Level of Q 10 Supplemented Tribal Sickle Cell Patients: A Hospital Based Study

The study has been undertaken as number of sickle cell patients in Chhattisgarh tribal population is 23.7 %. The Co enzyme Q10 is a strong antioxidant and energy producing compound. The patients were divided into three groups group A homozygous (SS), group B heterozygous (AS) and group C controls for TBARS study. The age group is 10–55 years and 200 mg of CoQ10 was given to A and B groups. The hematological parameters, C reactive protein as well as RBC TBARS level were performed by usual and standard techniques. The results were obtained as 25.37 % increased RBC level in group A and 23.24 % in group B. The increased hemoglobin level was observed as 16.73 % in group A and 10.7 % in group B. In case of WBC it was observed increased 24.38 % in group A and 12.0 % in group B. C-reactive protein was observed 7.8 times decreased in group A and 1.54 times in group B. The RBC TBARS level was also found decreased 48 % in group A and 51 % in group B as compared to group C. During the supplementation of coenzyme Q10 the pain caused by vaso-occlusive events has reduced. This significant increase in hematological parameters as well as decreased C-reactive protein and TBARS level suggest that the Q10 should be included in the diet of sickle cell patients.     

Children's experience of violence in China and Korea: a transcultural study

OBJECTIVE: There were two aims: First, to compare children's rates of being battered in home, by peers, and by teachers among students between China and Korea, and second, to identify particular risk factors for such violence. METHODS: Children in grades four through six in Shanghai (238 cases) and Yanji (245 cases) in China and Seoul (248 cases) and Kimpo (241 cases) in Korea were surveyed by questionnaire method. They were asked to complete the Straus' Conflict Tactics Scale and their frequencies in the three situations respectively, and other demographic items. RESULTS: Family violence during the last 1 year was experienced in 70.6% (minor 42.2%; serious 22.6%) of the children in China and 68.9% (minor 9.4%; serious 51.3%) of those in Korea. Experience rates of violence by peers were 42.7% (minor 25.7%; serious 13.7%) in China and 26.0% (minor 11.5%; serious 14.3%) in Korea. Finally, rates of corporal punishment by teachers were 51.1% (minor 28.0%; serious 4.1%) in China and 62.0% (minor 8.8%; serious 43.8%) in Korea. The most important and common risk factor for violence in one situation was the presence of violence in another situation. CONCLUSIONS: The findings indicate that the differences in children's overall experience rates were not particularly striking. However, Korean children experienced more severe forms of violence from family members and from teachers. Findings of risk factors clearly imply that there are children vulnerable to violence from multiple sources.     

Simulating Oppression: Digital Gaming,Race and the Education of African American Children

Educational game designers and educators are using digital games as a platform for teaching academic content, including multicultural curriculum. However, it is unclear how well digital game-based learning can coexist with the goals of multicultural education for the purpose of meeting the needs of African American children. In this essay, we raise serious questions about the use of digital games to teach about social oppression in ways that privilege the psychological well-being of African American children. We argue that digital games that intend to recreate histories of racial oppression can be harmful to African American children if they reproduce popular and problematic notions of indigenous lives and experiences. We illuminate some of the dangers of such digital games through a preliminary exploration of one digital game designed to teach about facets of African American enslavement. Our essay concludes with recommendations for culturally relevant digital game-based learning design and instruction.     

Alternating exposure to two compound flavors creates inhibitory associations between their unique features

Rats were exposed to two compound solutions, saline-lemon and sucrose-lemon. In Group ALT, trials with one solution alternated with trials with the other. Group BLK received all trials with one solution before any trials with the other. Previous retardation tests had implied that only alternating exposure would establish sucrose as an inhibitor of saline. To provide a complementary summation test for this inhibition, in Experiment 1, all the animals received pairings of peppermint and saline and were tested for consumption of peppermint-sucrose under sodium depletion. Consumption was increased by sodium depletion only in Group BLK. In Experiment 2, a retardation test was used to show that presentation of saline-lemon before sucrose-lemon on each exposure day would establish sucrose as an inhibitor of saline. Neither exposure to sucrose-lemon before saline-lemon nor alternating exposure to sucrose and saline alone had the same effect. These results provide support for an associative theory of perceptual learning that suggests that exposure to complex stimuli aids later discrimination partially as a result of establishing inhibitory associations between their unique elements.     

Inquiry and Astronomy: Preservice Teachers’ Investigations of Celestial Motion

This study investigated the impact of an open inquiry experience on elementary science methods students’ understanding of celestial motion as well as the methods developed by students to answer their own research questions. Pre/post interviews and assessments were used to measure change in participants’ understanding (N = 18). A qualitative approach was used to describe the nature of each participant’s investigation through an analysis of their science journal and poster presentations. A comparison of participants’ inquiry projects with the change in their understanding revealed that while most participants improved in both their area of inquiry and beyond, elementary science methods students may need more guidance to reach a full scientific understanding across all aspects of celestial motion.     

High school biology: What makes it a challenge for teachers?

This study contributes to our understanding of the complex issues inherent in dealing with the heterogeneity of current high school science classrooms, by reporting on in-depth interviews with 38 experienced biology teachers. Analyses of teachers' responses revealed complex and occasionally counter-intuitive relationships among: (a) their perceptions of what was distinctive about their school, its biology program, or their students; (b) their allocation of class time; (c) their efforts to individualize instruction and meet the needs of a heterogeneous student population; (d) their student outcome goals; and (e) the methods they used to evaluate student progress. Thus, for example, of the 9 teachers who cited the diversity of their students. 4 also commented on their poor motivation, but another 4 also commented on their high motivation. In addition, teachers reported using a similar range of instructional formats but for different reasons, depending on the characteristics of their students (e.g., cooperative learning groups used to compensate for poor attention spans, to challenge bright students, and to foster social tolerance). Discussion of these findings addresses several points of relevance for science education, teacher preparation, and curriculum reform. © 1996 John Wiley & Sons, Inc.     

Why users keep answering questions in online question answering communities: A theoretical and empirical investigation

This study theorized and validated a model of knowledge sharing continuance in a special type of online community, the online question answering (Q&A) community, in which knowledge exchange is reflected mainly by asking and answering specific questions. We created a model that integrated knowledge sharing factors and knowledge self-efficacy into the expectation confirmation theory. The hypotheses derived from this model were empirically validated using an online survey conducted among users of a famous online Q&A community in China, “Yahoo! Answers China”. The results suggested that users’ intention to continue sharing knowledge (i.e., answering questions) was directly influenced by users’ ex-post feelings as consisting of two dimensions: satisfaction, and knowledge self-efficacy. Based on the obtained results, we also found that knowledge self-efficacy and confirmation mediated the relationship between benefits and satisfaction.