Les structures protéiques peuvent être divisées en répétitives et apériodiques, les structures apériodiques correspondant pour la plupart à des protéines globulaires. Les protéines répétitives (PRs) contiennent des unités de répétitions adjacentes, appelées séquences répétées en tandem (TRs). Les PRs sont abondantes et ont une importance fonctionnelle fondamentale. De plus de nombreuses études ont démontré l'implication des TRs dans les pathologies humaines. Ainsi, la découverte des PRs et la compréhension de leur relation séquence-structure-fonction, offrent des perspectives de recherche prometteuses.Le développement d’initiatives en génomique structurale, combiné à une meilleure adaptation des techniques de cristallographie et de RMN à l’étude des protéines non globulaires, a permis d’élucider la structure d’un nombre croissant de PRs, d’où la nécessité de mettre en place un système de classification. Les structures répétitives ont été réparties en cinq classes, principalement fondées sur la longueur des TRs: Classe I - agrégats cristallins; Classe II - structures fibreuses; Classe III - structures allongées, dont la stabilité dépend des interactions qui s’établissent entre les motifs répétés. Classe IV - structures répétitives fermées ; Classe V - structures en collier de perles. Les efforts de ces dernières années ont abouti au développement d’outils bioinformatiques utiles à la détection et l'analyse d'éléments répétitifs présents au sein des structures protéiques (3D TRs). En fonction des caractéristiques des répétitions, certaines méthodes fonctionnent mieux que d'autres, mais, jusqu’à présent, aucune ne permettait de couvrir toute la gamme des répétitions. Ce constat nous a incités à développer une nouvelle méthode, appelée détecteur de protéines en tandem (TAPO). TAPO exploite les périodicités des coordonnées atomiques ainsi que d'autres types de représentation structurale, comprenant les chaînes générées par un alphabet conformationnel, les cartes de contact entre résidus, et les arrangements en vecteurs d'éléments de structure secondaire. Actuellement, sept scores, issus des caractéristiques analysées par TAPO, sont combinés à l’aide d’une Machine à Vecteur Support pour produire un score final permettant de différencier les protéines renfermant ou non des 3D TRs. En atteignant 94% de sensibilité et 97% de spécificité pour la référence actuelle, TAPO présente des performances améliorées par rapport aux autres méthodes de pointe. Le développement de TAPO offre de nouvelles opportunités pour l’analyse à grande échelle des protéines renfermant des 3D TRs. Ainsi, notre analyse de la base de données PDB, à l’aide de TAPO, a montré que 19% des protéines contiennent des 3D TRs. L'analyse à grande échelle des structures 3D TRs dans PDB nous a également permis de découvrir plusieurs nouveaux types de structures répétitives, absents de la classification existante et dont certains sont décrits ici.Nous avons entrepris une analyse complète des 3D TRs constitutifs du Rossmann Fold (RF). Notre intérêt pour les RFs a été suscité par le fait que de nombreuses protéines RFs représentent un cas ambigüe vis à vis des structures répétitives et non répétitives. A priori, les unités hélice α - feuillet β des RFs devraient avoir une forte tendance à s’empiler et donc, à former des structures répétitives. Afin de déterminer la fréquence à laquelle les RFs forment de longues unités de répétition empilées, nous avons sélectionné, à l’aide de TAPO, des structures contenant des RFs et les avons classées. Notre analyse montre que les RFs typiques ne peuvent pas être clairement définis comme des structures répétitives mais plutôt comme des unités de structures globulaires, comptant au plus trois répétitions α-β. Des éléments de discussion seront proposés pour tenter d’expliquer cette observation surprenante. / In general, protein structures can be divided into: repetitive and aperiodic structures. Most of the aperiodic structures are globular proteins. The repetitive proteins contain arrays of repeats that are adjacent to each other, called Tandem Repeats (TRs). Proteins containing TRs are abundant and have fundamental functional importance. Numerous studies demonstrated the involvement of such TR-containing proteins in human diseases. Furthermore, genetic instability of these regions can lead to emerging infection threats. Additionally, TR-containing structures have generated significant interest with respect to protein design as they can make excellent scaffolds for specific recognition of target molecules. Therefore, the discovery of these domains, understanding of their sequence–structure–function relationship promises to be a fertile direction for research.The growth of structural genomics initiatives, in combination with improvements in crystallographic and NMR techniques aimed at non-globular proteins, has resulted in an increase in structurally elucidated TR proteins. This has necessitated the development of classification schemes. Structural repeats were broadly divided into five classes mainly based on repeat length; Class I – crystalline aggregates; Class II – fibrous structures such as collagen; Class III – elongated structures where the repetitive units require each other for structural stability such as solenoid proteins; Class IV – closed repetitive structures, such as TIM-barrels and Class V – bead on a string structures such as tandems of Ig-fold domains. Despite this progress, the majority of bioinformatics approaches have focused on non-repetitive globular proteins.In recent years, efforts have been made to develop bioinformatics tools for the detection and analysis of repetitive elements in protein structures (3D TRs). Depending on the size and character of the repeats, some methods perform better than others, but currently no best approach exists to cover the whole range of repeats. This served as a motivation for the development of our method called the TAndem PrOtein detector (TAPO). TAPO exploits, periodicities of atomic coordinates and other types of structural representation, including strings generated by conformational alphabets, residue contact maps, and arrangements of vectors of secondary structure elements. Currently, seven feature based scores produced by TAPO are combined using a Support Vector Machine, producing a score to enable the differentiation between proteins with and without 3D TRs. TAPO shows an improved performance over other cutting edge methods, achieving 94% sensitivity and 97% specificity on the current benchmark. The development of TAPO provided new opportunities for large scale analysis of proteins with 3D TRs. In accordance with our analysis of PDB using TAPO, 19% of proteins contain 3D TRs. The large scale analysis of the 3D TR structures in PDB also allows us to discover several new types of TR structures that were absent in the existing classification. Some of them are described in the thesis manuscript. This suggests that TAPO can be used to regularly update the collection and classification of existing repetitive structures. In particular, a comprehensive analysis of 3D TRs related to Rossmann Fold (RF) was undertaken. Our special interest in RFs was based on the observation that many proteins with RFs represent borderline cases between repetitive and non-repetitive structures. In principle, α-helix-β-strand units of RFs should have a strong potential to stack one over the other, forming repetitive structures. To probe the question of how frequently RFs form long arrays of stacked repeats, we selected by using TAPO known RF-containing structures and classified them. Our analysis shows that typical RFs cannot be clearly defined as repetitive, rather they are part of globular structures with up to 3 αβ-repeats. We provide some explanations for this surprising observation.

The problem of this study was to determine the effects of computer programming instruction on fifth graders, as measured by gains, if any, on tests of logic and problem solving.

M. Tech. (Information Technology, Faculty of Applied and Computer Sciences, Vaal University of Technology / The number of students passing computer programming modules at Higher Education Institutions (HEIs) in South Africa at first year level is low. Only with the second attempt do most students pass. This delay results in students completing their three-year undergraduate qualification in four or even five years. One potential contribution towards addressing this problem is the introduction of a collaborative (cooperative) pedagogical approach where students develop software in teams, known in the Information Technology (IT) sector as pair-programming. This study endeavoured to investigate the impact of pair-programming on the academic progress of students registered for the Information Technology qualification at HEIs in South Africa. The study warranted the selection of action research as the most appropriate research strategy. Multi-methods data collection was carried out over two consecutive semesters. The data collection methods included a semi-structured interview, observations and empirical assessment. The participants were students registered for the Information Systems module, which focuses on software development. Pair-programming was introduced to one group of software development students, while a second group continued with the normal solo-programming approach. Semi-structured interviews were held with the students before commencement and after completion of the pair-programming intervention, to establish a change, if any, in the academic performance, attitude and enjoyment level of students introduced to pair-programming compared to those who continued with solo-programming. Observations were conducted throughout the course of the practical sessions over both semesters. Empirical assessments were done by means of tests given to both groups of students during the practical sessions, three tests per semester. Data analysis techniques included t-tests and thematic analysis. The findings concluded that pair-programming had a significant positive impact on the academic progress of IT students, including an increase in the enjoyment level and a more positive attitude towards software development.

The purposes of this study were (1) to determine if learning to program a computer in either BASIC or Logo improves the problem-solving skills of fifth grade students when compared to a control group that receives no programming instruction, and (2) to determine if learning to program a computer in Logo is more effective than learning to program in BASIC for improving problem-solving skills in fifth grade students. Subjects were 132 fifth graders from two suburban elementary schools. The materials used in the study were the Computer Challenge Guide for the BASIC group and Logo in the Classroom for the Logo group. The New Jersey Test of Reasoning Skills was used as the pretest and posttest measure.

The research described in this dissertation examines the possible link between self-regulated learning and LEGO Mindstorms robotics activities in teaching concepts in an introductory university computer programming course. The areas of student motivation, learning strategies, and mastery of course objectives are investigated. In all three cases analysis failed to reveal any statistically significant differences between the traditional control group and the experimental LEGO Mindstorms group as measured by the Motivated Strategies for Learning Questionnaire and course exams. Possible reasons for the lack of positive results include technical problems and limitations of the LEGO Mindstorms systems, limited number and availability of robots outside of class, limited amount of time during the semester for the robotics activities, and a possible difference in effectiveness based on gender. Responses to student follow-up questions, however, suggest that at least some of the students really enjoyed the LEGO activities. As with any teaching tool or activity, there are numerous ways in which LEGO Mindstorms can be incorporated into learning. This study explores whether or not LEGO Mindstorms are an effective tool for teaching introductory computer programming at the university level and how these systems can best be utilized.

Syftet med studien var att undersöka vilka stöd som matematiklärare erbjudits relativt programmering i matematikundervisningen. Därtill avsåg studien att undersöka vad matematiklärare önskar av ett stöd relativt programmering i matematik. Två datainsamlingsmetoder användes: en webbaserad enkät, och en semistrukturerad intervju. 29 enkätsvar erhölls och tre intervjuer genomfördes. Urvalspopulationen för dessa var matematiklärare i Stockholmsområdet. De insamlade data bearbetades med kvalitativ innehållsanalys där olika kategorier med tillhörande koder framkom, för att beskriva lärares uppfattningar av begreppet lärarstöd samt lärarnas åsikter om lärarstöd. Av enkätsvaren erhölls att 11 av 29 lärare upplevde att de inte erbjudits stöd för programmering i matematikundervisningen. Baserat på studiens resultat utvecklades ett lärarstödförslag vars syfte är att motsvara lärarnas önskemål på lärarstöd. Lärarstödförslaget består av ett upplägg för kompetensutveckling och lektionsplaner. / The purpose of the study was to examine which aids relative to programming in mathematics education the mathematics teachers have been offered. Moreover, the study sought to examine the desiderata of the mathematics teachers, relative to aid in programming in mathematics education. Two means of collecting data were used: a web based questionnaire, and a semi structured interview. 29 responses to the questionnaire were collected and three interviews were conducted. The sample population for the study was mathematics teachers in the Stockholm region. The collected data were processed with qualitative content analysis where different categories and codes emerged. The categories and codes describe the teachers’ understanding of the term teacher-aid, and the teachers’ opinion of teacher-aid. The questionnaire responses indicate that 11 of 29 teachers did not perceive that they were offered aid relative to programming in mathematics education. A teacher-aid-proposal with the purpose to match the desiderata of the teachers with respect to teacher-aids. The teacher-aid-proposal consists of a competence development arrangement and lesson plans.

No description available.

Typescript (photocopy). / Digitized by Kansas Correctional Industries

Call number: LD2668 .T4 1984 S39 / Master of Science / Biological and Agricultural Engineering

Call number: LD2668 .T4 1985 E34 / Master of Science