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The Global ETD Search service is a free service for researchers
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Networked Digital Library of Theses and Dissertations.
Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
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Showing 111 to 116 of 116 (0.36 seconds)| 111 |
Enhancing discourse through motivation : a case study of high school teaching in SwazilandSitsebe, Vusi Friday 30 January 2019 (has links)
Communication seems to play a pivotal role in any high school classroom. But it was found those classes or certain individual students shy away from engaging in effective communication during natural science lessons in Swaziland. One of the directives in the Swaziland National Education Policy states that syllabuses for studies in Form 4 and 5 should enable learners to develop essential skills which include communication and language skills. This study then, on realising that there was a gap between what was stated in the Education Policy and what was actually the case in the natural science classrooms, sought for a solution that would encourage effective communication in natural sciences. Therefore, the main purpose of the study was to encourage active participation of high school students in natural science lessons. The main research question posed for this purpose was:
Can student motivation enhance classroom discourse for the negotiation of science understanding?
Five sub-questions emanated from the main research question:
(a) How does classroom discourse relate to natural science understanding?
(b) What effect does external motivation have on discourse during natural science lessons?
(c) What is the effect of feedback during natural science learning?
(d) How can feedback be enhanced in the natural science class?
(e) Which teaching strategies improve interactions during natural science learning?
The study is organised into five chapters. The first chapter summarises the whole study by giving the problem statement, research aim and objectives, definition of terms, as well as chapter divisions. Chapter two provides the background to the study through the discussion of education theories based on classroom discourse and motivation. The third chapter presents detailed information about the research design, methods of data collection and analysis, as well as a proposed method for motivating students. The fourth chapter presents the research results, analysis and discussion. The fifth and the final chapter presents research findings, concluding remarks drawn from the research findings, as well as recommendations for similar future research.
The case study style uses a qualitative, descriptive and exploratory approach. The study concentrated on theories explaining learning and motivation. The sample comprised six purposefully selected students and their two physical science teachers. Data were collected using the standardised open-ended interview and non-participant lesson observation methods, and from documents. The data were collected in two phases, the pre-motivation phase and the motivation phase. The collected data was further categorised into two segments, with each segment being a unit of analysis. One of the segments was composed of oral interchanges, while the other was composed of students’ written work. The data was then transcribed, coded, analysed and discussed using the thematic discourse analysis approach. The principles of triangulation, reliability and validity ensured the credibility of the study remained intact. Research ethics were also observed by the researcher and there was trust, respect and autonomy during data collection. The ethics observed included informed consent, confidentiality, beneficence, anonymity and non-malificence. Permission to collect data was sought and obtained from all concerned.
The motivation method helped the physics group improve more (55%) than the chemistry group (7%) in tests. In the overall performance the two groups improved more or less the same: the chemistry group improved by 4% while the physics group improved by 5%. There were three main findings for the study and they revolved around the purpose and the research question. The first major finding was that the motivation method used with the students instilled self-discipline in the students, resulting in self-regulated behaviour and better understanding of science concepts. The finding suggested that motivated students are self-disciplined and take ownership of their learning. The second major finding was that during the motivation phase of data collection interactions improved between the students and their science teachers. These interactions were in the form of classroom talk, submission of school work and feedback. It was inferred that motivated students communicate more effectively and with better understanding of the concepts taught. The third major revelation was that the students were motivated by learner-centred teaching strategies and the use of teaching aids in a science laboratory.
A main finding for the first sub-question was that the more students interacted with each other, with their natural science teachers, and with their books the more they appreciated and understood science concepts. For the second sub-question the main finding was, the motivation method used with the students improved discourse during natural science lessons. The marks the students were awarded gave them the energy to engage more in science activities and to behave well. The main finding for the third sub-question was that prompt feedback and positive comments motivated students to engage more in science discourse and to understand science concepts better. An important finding from the fourth sub-question was that prompt and positive feedback enhanced feedback, as well as giving students tasks that were not too far above their abilities, enhanced feedback in the natural science class. For the fifth sub-question it was found that student-centred teaching methods as well as teaching aids and learning in science laboratories improved interactions during natural science learning. / Curriculum and Instructional Studies / D. Ed. (Curriculum Studies)
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Drug Discovery Targeting Bacterial and Viral non-coding RNA: pH Modulation of RNAStability and RNA-RNA InteractionsHossain, Md Ismail 23 May 2022 (has links)
No description available.
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Validation of the recognition-primed decision model and the roles of common-sense strategies in an adversarial environmentSoh, Boon Kee 24 April 2007 (has links)
This dissertation set out to understand the decision processes used by decision makers in adversarial environment by setting up an adversarial decision making microworld, as an experimental platform, using a real time strategy (RTS) game called Rise of Nations (RON). The specific objectives of this dissertation were:
1.Contribute to the validation of recognition-primed decision (RPD) model in a simulated adversarial environment;
2.Explore the roles of common-sense strategies in decision making in the adversarial environment; and
3.Test the effectiveness of training recommendations based on the RPD model.
Three related experimental studies were setup to investigate each of the objectives. Study 1 found that RPD model was partly valid where RPD processes were prevalently used but other decision processes were also important in an adversarial environment. A new decision model (ConPAD model) was proposed to capture the nature of decision making in the adversarial environment. It was also found that cognitive abilities might have some effects on the types of decision processes used by the decision makers.
Study 2 found that common-sense strategies were prevalent in the adversarial environment where the participants were able to use all but one of the warfare related strategies extracted from literature without teaching them. The strategy familiarization training was not found to significantly improve decision making but showed that common-sense strategies were prevalent and simple familiarization training was not sufficient to produce differences in strategy usage and performances from the novice participants. Study 3 also found that RPD based training (cue-recognition and decision skill training) were not significant in producing better performance although subjective feedback found such training to be useful. However, the participants with RPD based training conditions were able to perform on the same level as the expert participants bridging the gap between novices and experts.
Based on the findings, it was recommended that decision training should involve not just RPD based training, but comparisons of attributes as well. A more interactive training combining common-sense strategies, cue-recognition and decision skill training might be more useful. More theoretical experimentation would be required to validate the new decision model proposed in this dissertation. / Ph. D.
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Imagerie ultrarapide à l’échelle nanométrique par diffraction XUV cohérente / Ultrafast coherent XUV diffractive imaging at nanometer scaleGe, Xunyou 11 December 2012 (has links)
Imager des objets non-périodiques à une échelle nanométrique et à une échelle femto seconde est un vrai challenge à notre époque. Les techniques d’imagerie « sans lentille » sont des moyens puissants pour répondre à ce besoin. En utilisant des sources ultrarapide (~fs) et cohérente (ex. laser à électron libre ou harmoniques d’ordres élevés), ces techniques nous permettent de reconstruire des objets à partir de leur figure de diffraction, remplaçant les optiques conventionnelles du système d’imagerie par un algorithme informatique. Dans ce travail de thèse, je présent des expériences d’imageries en utilisant un rayonnement extrême-UV (15~40 nm) produit par la génération d’harmoniques d’ordre élevé d’un laser infrarouge puissant. Ce manuscrit est constitué d’une introduction, un chapitre de background théorique, trois chapitres de travail de thèse et une conclusion générale avec perspectives. La première partie du travail de thèse porte sur les développements et caractérisations de la ligne de lumière avec l’objectif de générer maximum de photons harmoniques cohérents avec un front d’onde plat. La deuxième partie est consacrée aux expériences et analyses de trois techniques d’imageries « sans lentille » : Imagerie par diffraction cohérente (CDI), Holographie par la transformée de Fourier (FTH) et Holographie avec références étendues (HERALDO). Ces derniers nous permettent de reconstruire des objets avec une résolution spatiale de 78 nm dans le cas de CDI et de 112 nm dans le cas de HERALDO, tous les deux avec une résolution temporaire de 20 fs. La troisième partie est une première application physique de l’imagerie sur la ligne harmonique. Il s’agit des études statiques et dynamiques de nano-domaines magnétique avec une résolution spatiale sub-100 nm à l’échelle femto seconde. Perspective des techniques d’imagerie 3D et développement potentiel de la ligne d’harmoniques sont présentés à la fin. / Ultrafast imaging of isolated objects with nanometric spatial resolution is a great challenge in our time. The lensless imaging techniques have shown great potential to answer this challenge. In lensless imaging, one can reconstruct sample images from their diffraction patterns with computational algorithms, which replace the conventional lens systems. Using ultrafast and coherent light sources, such as free electron laser and high order harmonics, one can investigate dynamic phenomena at the femtosecond time scale. In this thesis work, I present the lenless imaging experiments using XUV radiation provided by a laser driven high order harmonic beamline. The manuscript is composed of an introduction, a chapter of theoretical background, three chapters of main research work and a general conclusion with perspectives. The first part of this work concerns the development of the harmonic beamline to optimize the illumination condition for lensless imaging. The second part concentrates on the imaging techniques: the Coherent Diffraction Imaging (CDI), the Fourier Transform Holography (FTH) and the Holography using extended references (HERALDO). The reconstructions have achieved 78 nm spatial resolution in case of CDI and 112 nm resolution in case of HERALDO, both in single-shot regime corresponding to a temporal resolution of 20 fs. The third part presents the first physical application on the harmonic beamline using the lensless imaging. Samples with magnetic nano-domains have been studied with sub-100 nm spatial resolution, which paves the way for ultrafast magnetic dynamic studies. At the end, single-shot 3D imaging and further beamline development have been discussed.
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The Human Y chromosome and its role in the developing male nervous systemJohansson, Martin M. January 2015 (has links)
Recent research demonstrated that besides a role in sex determination and male fertility, the Y chromosome is involved in additional functions including prostate cancer, sex-specific effects on the brain and behaviour, graft-versus-host disease, nociception, aggression and autoimmune diseases. The results presented in this thesis include an analysis of sex-biased genes encoded on the X and Y chromosomes of rodents. Expression data from six different somatic tissues was analyzed and we found that the X chromosome is enriched in female biased genes and depleted of male biased ones. The second study described copy number variation (CNV) patterns in a world-wide collection of human Y chromosome samples. Contrary to expectations, duplications and not deletions were the most frequent variations. We also discovered novel CNV patterns of which some were significantly overrepresented in specific haplogroups. A substantial part of the thesis focuses on analysis of spatial expression of two Y-encoded brain-specific genes, namely PCDH11Y and NLGN4Y. The perhaps most surprising discovery was the observation that X and Y transcripts of both gene pairs are mostly expressed in different cells in human spinal cord and medulla oblongata. Also, we detected spatial expression differences for the PCDH11X gene in spinal cord. The main focus of the spatial investigations was to uncover genetically coded sexual differences in expression during early development of human central nervous system (CNS). Also, investigations of the expression profiles for 13 X and Y homolog gene pairs in human CNS, adult brain, testes and still-born chimpanzee brain samples were included. Contrary to previous studies, we found only three X-encoded genes from the 13 X/Y homologous gene pairs studied that exhibit female-bias. We also describe six novel non-coding RNAs encoded in the human MSY, some of which are polyadenylated and with conserved expression in chimpanzee brain. The description of dimorphic cellular expression patterns of X- and Y-linked genes should boost the interest in the human specific gene PCDH11Y, and draw attention to other Y-encoded genes expressed in the brain during development. This may help to elucidate the role of the Y chromosome in sex differences during early CNS development in humans. / <p>chinese, finnish, norwegian, schizophrenia, bipolar, bipolar disorder, msy, male specific region Y, PAR1, PAR2, pseudoautosomal, male-biased, female-biased, male biased, female biased, ashkenazi population, structure, variants, YHRD, Elena Jazin, Björn Reinius, Per Ahlberg, brain, hjärna, CNS, central nervous system, IR2, inverted repeat 2, isodicentric, genetics, genetik, padlock, rolling circle, amplification, PCR, sY1191, sY1291, STS, DDX3Y, DAZ, AZFa, AZFb, AZFc, AZF, Repping, haplogroup J, rearrangements, DE-M145, I-M170, E-M96, Q-M242, R-M207, O-M175, G-M201, D-M174, C-M130, NO-M214, N-M231, poland</p>
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Channel Probing for an Indoor Wireless Communications ChannelHunter, Brandon 13 March 2003 (has links) (PDF)
The statistics of the amplitude, time and angle of arrival of multipaths in an indoor environment are all necessary components of multipath models used to simulate the performance of spatial diversity in receive antenna configurations. The model presented by Saleh and Valenzuela, was added to by Spencer et. al., and included all three of these parameters for a 7 GHz channel. A system was built to measure these multipath parameters at 2.4 GHz for multiple locations in an indoor environment. Another system was built to measure the angle of transmission for a 6 GHz channel. The addition of this parameter allows spatial diversity at the transmitter along with the receiver to be simulated. The process of going from raw measurement data to discrete arrivals and then to clustered arrivals is analyzed. Many possible errors associated with discrete arrival processing are discussed along with possible solutions. Four clustering methods are compared and their relative strengths and weaknesses are pointed out. The effects that errors in the clustering process have on parameter estimation and model performance are also simulated.
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