Ultrasound directed self-assembly (DSA) relies on the acoustic radiation force associated with a standing ultrasound wave to organize particles dispersed in a fluid medium into specific patterns. State-of-the-art ultrasound DSA methods can only organize particles into (quasi-)periodic patterns, limited by the use of single-frequency ultrasound wave fields. Acoustic holography and acoustic waveguides provide alternatives to assembling complex patterns of particles, but generally provide low spatial accuracy and are not re-configurable because they require custom hardware for each specific pattern of particles, which is impractical. We introduce multi-frequency ultrasound wave fields to organize particles in non-periodic patterns. We theoretically derive and experimentally validate a solution methodology to determine the operating parameters (frequency, amplitude, phase) of any number and spatial arrangement of ultrasound transducers, required to assemble spherical particles dispersed in an inviscid fluid medium into any specific two-dimensional pattern. The results show that multi-frequency ultrasound DSA enables the assembly of complex, non-periodic patterns of particles with substantially fewer ultrasound transducers than single-frequency ultrasound DSA, and without incurring a penalty in terms of accuracy. The results of this work fundamentally transform the state-of-the-art knowledge of ultrasound DSA. Multi-frequency ultrasound wave fields enable a near-unlimited complexity of patterns of particles that can be assembled, increasing the relevance of the technology to practical implementation in engineering applications such as manufacturing of engineered composite materials that derive their properties from the spatial organization of the filler in the matrix material. Although this work focuses specifically on ultrasound wave fields, the theoretical model is valid for all wave phenomena. / Master of Science / Ultrasound directed self-assembly (DSA) is the process where particles dispersed in a fluid medium assemble into specific patterns due to their interactions with a sound wave and/or other particles. Current ultrasound DSA methods use a single-frequency ultrasound wave to assemble particles into specific patterns, which creates repeating patterns within the fluid medium. Other methods of assembling particles that allow for more complex, non-repeating patterns generally provide low spatial accuracy and do not allow dynamically changing the pattern as they require custom hardware for each specific pattern of particles, rendering these methods impractical. We use many ultrasound waves each with a different frequency to organize particles into complex, non-repeating patterns, which we call multi-frequency ultrasound DSA. We theoretically derive and experimentally validate a method that allows us to assemble any specific two-dimensional pattern of particles using multi-frequency ultrasound DSA. The results show that multi-frequency ultrasound DSA enables the assembly of complex, non-repeating patterns of particles with substantially resources than single-frequency ultrasound DSA, and without incurring a penalty in terms of accuracy. Multi-frequency ultrasound DSA enables a near-unlimited complexity of patterns of particles that can be assembled, increasing the relevance of the technology to practical implementation in engineering applications.

Rapid scientific and technological advances in health care mean that nurses need to keep learning and engage in professional education so that they can continue to provide safe and quality care. Education programs which prepare nurses for practice as a registered nurse have a vital role to play in ensuring that graduates are self-directed in responding to the need for ongoing learning throughout their professional career. In many countries, improving students’ readiness for self-directed learning has thus gained increasing recognition as being an important goal of nursing education programs. This level of interest in developing self-directedness in learning is evident in many policy documents and research in Taiwan. The aim of this study was to investigate factors influencing self-directed learning readiness amongst Taiwanese nursing students. A conceptual framework adopted from Biggs’s ‘3P model of teaching and learning’ was constructed to guide this study’s investigation. This study employed a two-staged mixed-method design to obtain a better understanding of Taiwanese students’ experience of SDL in undergraduate nursing programs. Stage one of the present study was a qualitative approach using semi-structured interview to explore students’ experiences with learning activities which they perceived to be self-directed in their undergraduate programs. Eight students were interviewed. Findings from this stage reveal that participants perceived a shift in teaching and learning styles between their previous nursing programs and the university. The more frequent use of student-directed learning activities, in which students were encouraged to be active and to take responsibility for their learning tasks, was one of the changes in teaching and learning approaches perceived by participants. Participants further suggested a number of factors that influenced the outcomes of these learning activities, including teacher-student interaction, facilitation process and learning resources. Stage two of this study used a quantitative approach consisting of two phases: instrument pilot testing and a cross-sectional survey. In the first phase, the instruments were translated into Chinese through a rigorous translation process and tested with a convenience sample of nursing students in Taiwan. Results indicated the translated instruments were reliable and stable. The second phase, a cross-sectional survey, was conducted to examine the conceptual framework of this study. A total of 369 undergraduate nursing students completed the questionnaire. Results of data analysis provides support for the conceptual framework proposed for this study, suggesting that students’ achievement goals and their perceptions of the learning environment significantly influence their adoption of learning approaches and the development of SDL readiness. Based on the results, this study provides practical implications that nurse educators may adopt to enhance students’ SDL readiness. This study also provides theoretical implications and recommendations for future research. It is envisaged that these recommendations may help future researchers focus their research design and further understandings of how to help students develop their ability to become self-directed learners.

This thesis concerns an active research area within fractal geometry. In the first part, in Chapters 2 and 3, for directed graph iterated function systems (IFSs) defined on ℝ, we prove that a class of 2-vertex directed graph IFSs have attractors that cannot be the attractors of standard (1-vertex directed graph) IFSs, with or without separation conditions. We also calculate their exact Hausdorff measure. Thus we are able to identify a new class of attractors for which the exact Hausdorff measure is known. We give a constructive algorithm for calculating the set of gap lengths of any attractor as a finite union of cosets of finitely generated semigroups of positive real numbers. The generators of these semigroups are contracting similarity ratios of simple cycles in the directed graph. The algorithm works for any IFS defined on ℝ with no limit on the number of vertices in the directed graph, provided a separation condition holds. The second part, in Chapter 4, applies to directed graph IFSs defined on ℝⁿ . We obtain an explicit calculable value for the power law behaviour as r → 0⁺ , of the qth packing moment of μ[subscript(u)], the self-similar measure at a vertex u, for the non-lattice case, with a corresponding limit for the lattice case. We do this (i) for any q ∈ ℝ if the strong separation condition holds, (ii) for q ≥ 0 if the weaker open set condition holds and a specified non-negative matrix associated with the system is irreducible. In the non-lattice case this enables the rate of convergence of the packing L[superscript(q)]-spectrum of μ[subscript(u)] to be determined. We also show, for (ii) but allowing q ∈ ℝ, that the upper multifractal q box-dimension with respect to μ[subscript(u)], of the set consisting of all the intersections of the components of F[subscript(u)], is strictly less than the multifractal q Hausdorff dimension with respect to μ[subscript(u)] of F[subscript(u)].

One of the major priorities for community colleges is to focus on the pedagogical tools that will allow students to achieve excellence and quality in curriculum and instruction to meet the changing societal needs (Shearon & Tollefson, 1989). Rapid demographic, social, and technological changes demand that community colleges produce self-directed lifelong learners (Closson, 1996). The study of student learning preferences for more teacher-directed or more self-directed learning is one of the concepts that is important in enhancing teaching and learning practices. The purpose of this study was to examine students' teacher-directed versus self-directed learning preferences in specific courses. The possible relationships among age, gender, and academic majors and the learning preferences (teacher-directed or self-directed) were also explored. The revised version of Learning Style Preference Questionnaire (LSPQ) originally designed by Hinkle (1990) was administered to 563 students at five selected community colleges in the southeast. The majority of the participants were female traditional students majoring in the natural sciences. The sample showed a preference for teacher-directed orientation in specific courses. Statistically significant differences were observed in the magnitude of the teacher-directed orientation between the mean scores of male and female students with male students scoring significantly higher than the female students. Traditional students obtained significantly higher mean scores on the items addressing the delivery of instruction than the nontraditional students. Nontraditional students obtained significantly higher mean scores on the items addressing the testing of learning. Gender had an impact on the magnitude of the teacher-directed learning preferences for evaluation and testing of learning. Academic majors had an impact on the magnitude of the teacher-directed learning preferences for evaluation of learning. Students in this study preferred a teacher-directed approach to learning. Follow-up research using a variety of instruments may investigate how this preference contributes to or affects academic achievement. It is recommended that the methods and procedures adopted in this study be replicated in other community colleges across the nation. Learning preference concepts and methods should be developed at the community college level to include professional development of instructors so that they may better provide learning opportunities for their students. Such studies may also be conducted in other parts of the world to determine how cultural differences may impact on learning preferences.

No description available.

This thesis is concerned with the efficient computation of Jacobian matrices of nonlinear vector maps using automatic differentiation (AD). Specifically, we propose the use of two directed edge separator methods, the weighted minimum separator and natural order separator methods, to exploit the structure of the computational graph of the nonlinear system.This allows for the efficient determination of the Jacobian matrix using AD software. We will illustrate the promise of this approach with computational experiments.

The purpose of this study was to show the effect of creativity on adults as a means of coming to terms with parental rejection experienced in childhood. The study was done according to a practical theological interpretation of the three-phase hermeneutical model of Ricoeur, namely: ? understanding according to Scriptural perspectives (basis-theoretical), as well as on a metatheoretical level by means of a literature study; ? interpreting by means of an empirical research in the form of interviews with respondents; ? change by means of practical theoretical guidelines for the creative adult who processed parental rejection experienced in childhood by the pursuing of person-directed creativity. Understanding on the basis-theoretical level showed the following: With the fall in paradise, man rejected God and tried to fulfil his / her own needs independently. The arts were also contaminated and artists moved away from God, the Creator and Source of their creativity, to pursue their art in a self-centred and arrogant way. Creativity is being used with wrong motives as a method of selfhealing to process unresolved pain from the past. The honour which God deserves is lost and without Him mankind, as well as art, deteriorates. Art does show therapeutic value if it is directed towards God, but otherwise the success is temporary and superficial. The literature study of ten well known creative individuals showed that the therapeutic effect of the pursuit of creativity to process parental rejection in childhood, failed sadly and ended in disillusionment for all of them. Their lives were a continuous search for healing and wholeness, as well as peace, meaning and happiness, whereas their personal relationships were destructive and / or broken and unhappy. The empirical research with creative adults who experienced parental rejection in childhood, and used their creativity as a means of processing it, provided an explanation for the effect of this on these creative adults. Their creativity was directed at the self instead of at God and failed to process the hurt of childhood, as well as bringing about inner peace for a healthy relationship with God, the self and others, especially loved ones.. To effect change, practical theoretical guidelines were established to guide the creative man or woman, who experienced parental rejection in childhood, by the use of their creative medium, to embark on the road to recovery and healing with God?s help. The main goal of the practical guidelines is bringing redemption to the creative person through Jesus Christ so that he / she will use his or her creativity in future to honour and praise God, as well as to serve the fellowman. / Thesis (Ph.D. (Pastoral))--North-West University, Potchefstroom Campus, 2011.

The purpose of this study was to show the effect of creativity on adults as a means of coming to terms with parental rejection experienced in childhood. The study was done according to a practical theological interpretation of the three-phase hermeneutical model of Ricoeur, namely: ? understanding according to Scriptural perspectives (basis-theoretical), as well as on a metatheoretical level by means of a literature study; ? interpreting by means of an empirical research in the form of interviews with respondents; ? change by means of practical theoretical guidelines for the creative adult who processed parental rejection experienced in childhood by the pursuing of person-directed creativity. Understanding on the basis-theoretical level showed the following: With the fall in paradise, man rejected God and tried to fulfil his / her own needs independently. The arts were also contaminated and artists moved away from God, the Creator and Source of their creativity, to pursue their art in a self-centred and arrogant way. Creativity is being used with wrong motives as a method of selfhealing to process unresolved pain from the past. The honour which God deserves is lost and without Him mankind, as well as art, deteriorates. Art does show therapeutic value if it is directed towards God, but otherwise the success is temporary and superficial. The literature study of ten well known creative individuals showed that the therapeutic effect of the pursuit of creativity to process parental rejection in childhood, failed sadly and ended in disillusionment for all of them. Their lives were a continuous search for healing and wholeness, as well as peace, meaning and happiness, whereas their personal relationships were destructive and / or broken and unhappy. The empirical research with creative adults who experienced parental rejection in childhood, and used their creativity as a means of processing it, provided an explanation for the effect of this on these creative adults. Their creativity was directed at the self instead of at God and failed to process the hurt of childhood, as well as bringing about inner peace for a healthy relationship with God, the self and others, especially loved ones.. To effect change, practical theoretical guidelines were established to guide the creative man or woman, who experienced parental rejection in childhood, by the use of their creative medium, to embark on the road to recovery and healing with God?s help. The main goal of the practical guidelines is bringing redemption to the creative person through Jesus Christ so that he / she will use his or her creativity in future to honour and praise God, as well as to serve the fellowman. / Thesis (Ph.D. (Pastoral))--North-West University, Potchefstroom Campus, 2011.

Self-directed learning (SDL) readiness skills and the command and/or retention of content knowledge have been identified as key factors for success in post-secondary settings. The Government of Jamaica (GOJ) has stated that two in three Jamaican secondary school graduates lack the requisite content knowledge and self-directed learning skills needed for advancement in the work space and in postsecondary education (Vision 2030 Jamaica National Development Plan, 2009). This dissertation examined the efficacy of project-based learning (PBL) as a method of instruction for improving SDL readiness skills and content knowledge retention. More specifically, the phenomenon was explored within the context of a developing country – in this case – Jamaica. The difference in SDL readiness skills and content knowledge retention was investigated among 8th grade students in an urban high school under PBL conditions (N = 30) and under Traditional Direct Instruction (N=35) using a quasi-experimental design. Data on students’ SDL readiness skills, knowledge comprehension and content knowledge retention were collected using validated instruments. Scores on all three measures were recorded pre-intervention and post-intervention with a follow-up on content knowledge retention. One way repeated measures mixed ANOVAs were run. Results showed that on SDL readiness skills, the difference over time for the PBL group was significantly different from the difference over time for the TDI/control group (pp

L’objectif de mon projet principal de thèse est de déterminer la fonction biologique d’un lncARN conservés chez le zebrafish que nous avons appelé libra. La séquence de libra étant hautement homologue à la région 3’UTR de la protéine Nrep. Ces deux transcrits, libra et Nrep, contiennent en effet un site de liaison au miARN profondément conservé et inhabituellement complémentaire au miR-29. En utilisant à le modèle souris et les cellules murines, nous avons décrypté la relation régulatrice entre ce transcrit conservé dans l’évolution des vertébrés et la voie métabolique des miARN. Nous avons montré que Nrep limite le domaine d’expression de miR-29 au cervelet, et qu’il le déstabilise en rognant sa séquence. Notre travail révèle donc le premier exemple de dégradation endogène ciblée des miARN (ou TDMD). De plus, un ensemble d’expériences in vivo sur les modèles zebrafish et souris, nous a permis de démontrer que libra et Nrep contrôlent tout les deux le comportement animal. Via la perturbation génétique du site de liaison au miARN de Nrep murin, nous avons observé que ce gène régule le dosage du miR29 de part son site de liaison aux miARN, et que cette régulation est nécessaire à un comportement animal normal. Dans la seconde partie de ma thèse, je décris une stratégie exploré afin de déréguler les lncARN de la manière la moins invasive possible. Les lncARN sont actuellement neutralisés par des approches qui introduisent de vastes changements de séquence au niveau génomique. Nous avons donc développer une stratégie in vivo, appliquée au zebrafish, qui inactive les lncARN via l’insertion génomique d’une séquence ribozyme autoclivante ou d’un signal polyA prématuré. / The goal of my main thesis project was to determine the biological function of a deeply conserved zebrafish long noncoding RNAs (lncRNA) which we called libra. libra shows sequence similarity with the 3'UTR of the NREP a protein coding transcript. Both libra and Nrep contain a deeply conserved and unusually complementary microRNA (miRNA) binding site for miR-29. Using both the mouse model and mouse cell lines, we deciphered the regulatory relationship between this conserved transcript and the miRNA pathway. We showed that Nrep restricts the spatial expression domain of miR-29 in the cerebellum and that it destabilizes miR-29 through 3' trimming. Until now, only viral transcripts and artificial reporters engineered to contain highly complementary miRNA binding sites have been shown to regulate miRNAs in this fashion. Thus, our work uncovers the first example of endogenous target-directed miRNA degradation (TDMD). In addition, through a set of in vivo experiments in zebrafish and mouse, we showed that both libra and Nrep control normal animal behavior. By genetically disrupting the miR-29 binding site in Nrep in mouse, we showed that Nrep regulates miR-29 dosage through its miR-29 site and controls animal behavioral. In a second part of my thesis I describe a strategy to genetically downregulate lncRNAs in a minimally invasive manner. Approaches to knock-out lncRNAs that do not introduce vast sequence changes at the genomic level have not been adequately developed yet. I present our in vivo strategy applied to the zebrafish model using a genomic knock-in of a self-cleaving ribozyme sequence and a premature poly(A) signal to knock-out lncRNAs.