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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the 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.
101

Combining 'phonics' and 'whole language' approaches in teaching reading : a case study of Phenduka Literacy Project in an Alexandra school.

Murahwa, Sindisiwe 10 February 2009 (has links)
This research report is a case study, the aim of which is to describe and analyse the methods used by a non-profit organization in teaching Grade Seven (7) learners with reading difficulties in an Alexandra Township school, by using a combination of the whole language and phonics approaches. It involves Phenduka Literacy Project facilitators immersed in a two to three week literacy intervention with an average of 30- 35 Grade 7 learners at Dr Knak Primary School. The aim of the Phenduka programme is to improve learners’ levels of reading so that they can meet the demands of high school education. Data was collected by analysing the teaching material, carrying out semi-structured interviews with Phenduka facilitators, and observing the facilitators at work. The findings revealed that there is no one suitable method for teaching reading; rather, using an integrated approach would bear much fruits. It is envisaged that the findings of this study would enlighten teachers in disadvantaged communities in South Africa who face the same scenario of dealing with poor readers and using limited teaching/learning resources.
102

A Multi-level Model for Analysing Whole Genome Sequencing Family Data with Longitudinal Traits

Chen, Taoye 24 April 2013 (has links)
Compared to microarray-based genotyping, next-generation whole genome-sequencing (WGS) studies have the strength to provide greater information for the identification of rare variants, which likely account for a significant portion of missing heritability of common human diseases. In WGS, family-based studies are important because they are likely enriched for rare disease variants that segregate with the disease in relatives. We propose a multilevel model to detect disease variants using family-based WGS data with longitudinal measures. This model incorporates the correlation structure from family pedigrees and that from repeated measures. The iterative generalized least squares (IGLS) algorithm was applied to estimation of parameters and test of associations. The model was applied to the data of Genetic Analysis Workshop 18 and compared with existing linear mixed effect (LME) models. The multilevel model shows higher power at practical p-value levels and a better type I error control than LME model. Both multilevel and LME models, which utilize the longitudinal repeated information, have higher power than the method that only utilize data collected at one time point.
103

Noise and whole-body vibration in underground locomotive operators

Southon, Sharon 16 March 2011 (has links)
MPH, Occupational Hygiene, Faculty of Health Sciences, University of the Witwatersrand / Introduction Locomotive operators in the mining industry are exposed to high levels of noise and vibration. There is currently limited information indicating whole-body vibration exposure levels conducted over an 8-hour time weighted average (TWA) exposure period; most of the available data are based on instantaneous measurements. The 10-Ton New Era locomotive was specifically designed with the focus on areas such as ergonomics, safety, future automation, productivity and flexibility of use. The locomotive has a single cab and can be driven and controlled with maximum visibility in the direction of travel. Most mining houses are converting from the use of the 10 Ton Goodman battery operated locomotive to the 10Ton New Era locomotive, hence the focus of noise and vibration measurements on the latter. Objectives This research report documents a project to measure noise and whole-body vibration exposure levels of locomotive operators working in an underground platinum mine. The objectives of the study are: • to describe the eight hour time weighted average occupational noise exposure levels of locomotive operators operating the 10-Ton New Era locomotive in an underground platinum mine over 2008 and 2009; • to describe personal whole-body vibration exposure levels of locomotive operators operating the 10-Ton New Era locomotive in an underground platinum mine over 2008 and 2009; and 5 • to determine whether personal noise and whole-body vibration exposure levels of locomotive operators operating the 10-Ton New Era locomotive in an underground platinum mine over 2008 and 2009 comply with national and international standards. Methods Personal noise and whole-body vibration exposure measurements were obtained from 21 underground locomotive operators. Measurements were conducted in accordance with the procedures described in the SANS 10083 standard for personal noise dosimetry and the ISO 2631-1 standard for whole-body vibration. Determination of likely health risks for the operators were based on a comparison of the measured time-weighted noise exposure levels with the South African OEL and the ACGIH threshold limit value; whole-body vibration levels were compared with the HGCZ limits presented in Annex B of the ISO 2631-1 standard and the EU directive daily exposure limits. Results The measured noise and whole-body vibration levels taken over an 8-hour TWA exposure period were higher when compared to national and international standards. The mean LTWA levels for noise was 66.5 dB(A) with 12.5% of the measurements exceeding the South African OEL of 85dB(A). 45% of the wholebody vibration measurements fell within the HGCZ indicating that whole-body vibration exposure on locomotive operators presents a moderate probability for an adverse health outcome. Discussion and Conclusion Locomotive operators are exposed to potentially harmful levels of noise and whole-body vibration. The Mine Health and Safety Act requires an employer to assess the health and safety risks that hazards pose to their employees, and to take reasonably practicable steps towards eliminating or controlling those risks. Like any other risks at a workplace, noise and whole-body vibration needs to be 6 identified and controlled, and the approach to be taken is one of a risk management
104

Empathy as a factor of the sublime and beautiful in a wilderness environment

Unknown Date (has links)
Contemporary views on the aesthetics of nature fall into two opposing schools of thought; the cognitive school where philosophers such as Allen Carlson believe that science can explain everything about the aesthetics of nature, and the non-cognitive where, for example, Arnold Berleant maintains that science is a sufficient though not a necessary condition for the aesthetic appreciation of nature. Berleant and others of his kind contend that an engaged multi-sensuous relationship with nature will manifest the required experience. Empathy with nature, specifically primal empathy is the focus of this research, but empathy can only be experienced from a phenomenological perspective. I have walked over two hundred miles in over 70 Florida state parks, including an autumn trip to Vermont and back. During this journey I came to experience a personal connection (empathy) with nature that I now believe is grounded in holism and a methodology of the sublime leading to the beautiful. The main conclusions derived from this research are: self-realized individuals will experience the connection I speak of more quickly than those who are not, and the genius nature artist through a creative act grounded in primal empathy can reveal the Ideas or Forms of nature to those who would otherwise never experience them. This research also concludes that empathy with nature, specifically primal empathy, is a new element that can reduce the cleft and help unify the two opposing views. / by Robert L.J. Axberg. / Thesis (Ph.D.)--Florida Atlantic University, 2011. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2011. Mode of access: World Wide Web.
105

Multiple displacement amplification and whole genome sequencing for the diagnosis of infectious diseases

Anscombe, C. J. January 2016 (has links)
Next-generation sequencing technologies are revolutionising our ability to characterise and investigate infectious diseases. Utilising the power of high throughput sequencing, this study reports, the development of a sensitive, non-PCR based, unbiased amplification method, which allows the rapid and accurate sequencing of multiple microbial pathogens directly from clinical samples. The method employs Φ29 DNA polymerase, a highly efficient enzyme able to produce strand displacement during the polymerisation process with high fidelity. Problems with DNA secondary structure were overcome and the method optimised to produce sufficient DNA to sequence from a single bacterial cell in two hours. Evidence was also found that the enzyme requires at least six bases of single stranded DNA to initiate replication, and is not capable of amplification from nicks. Φ29 multiple displacement amplification was shown to be suitable for a range of GC contents and bacterial cell wall types as well as for viral pathogens. The method was shown to be able to provide relative quantification of mixed cells, and a method for quantification of viruses using a known standard was developed. To complement the novel molecular biology workflow, a data analysis pipeline was developed to allow pathogen identification and characterisation without prior knowledge of input. The use of de novo assemblies for annotation was shown to be equivalent to the use of polished reference genomes. Single cell Φ29 MDA samples had better assembly and annotation than non-amplification controls, a novel finding which, when combined with the very long DNA fragments produced, has interesting implications for a variety of analytical procedures. A sampling process was developed to allow isolation and amplification of pathogens directly from clinical samples, with good concordance shown between this method and traditional testing. The process was tested on a variety of modelled and real clinical samples showing good application to sterile site infections, particularly bacteraemia models. Within these samples multiple bacterial, viral and parasitic pathogens were identified, showing good application across multiple infection types. Emerging pathogens were identified including Onchocerca volvulus within a CSF sample, and Sneathia sanguinegens within an STI sample. Use of Φ29 MDA allows rapid and accurate amplification of whole pathogen genomes. When this is coupled with the sample processing developed here it is possible to detect the presence of pathogens in sterile sites with a sensitivity of a single genome copy.
106

Adaptive control of an active seat for occupant vibration reduction

Gan, Zengkang January 2015 (has links)
Vehicle occupants are typically exposed to unpleasant whole-body vibration (WBV) for extended period of time. It is well known that the transmission of unwanted vibration to the human body can lead to fatigue and discomfort. Moreover, the unwanted vibration normally distributed in the low-frequency range has been found as the main risk factor for lower back pain and lumbago, which seriously affect the health and working performance of occupants. Thus vibration cancellation on seats has attracted considerable interest in recent years. So far, for most vehicle seats, vibration isolation is achieved passively by using seat cushions and conventional energy absorbers, which have very limited performance in the low-frequency range. The work presented in this thesis forms a successful development and experimental study of an active seat and control algorithm for occupants’ WBV reduction under low frequency excitations. Firstly, a modelling study of the seat human subjects (SHS) and an extensive experimental measurement of the vibration transmissibility of a test dummy and vehicle seat are carried out. The biodynamic responses of SHS exposed to uncoupled vertical and fore-and-aft WBV is modelled. A comparison with the existing models is made and the results show that an improved fit with the aggregated experimental data is achieved. Secondly, an active seat is developed based upon the observations and understanding of the SHS and seat system. The characteristics of the active seat dynamics are identified through experimental tests found suitable for the development of an active seat to attenuate the vibration experienced by vehicle occupants. The vibration cancellation performance of the active seat is initially examined by feedforward plus proportional-integral (PI) control tests. Through these tests, the effectiveness of the actuators control authority is verified, but the limitations are also revealed. Because the active seat system is subject to non-linear and time-varying behaviour, a self-tuning fully adaptive algorithm is a prime requirement. The Filtered-x Least-Mean-Square (FXLMS) algorithm with the Fast-block LMS (FBLMS) system identification technique is found suitable for this application and is investigated through experimental tests. Substantial vibration reductions are achieved for a variety of input vibration profiles. An excellent capability of the active seat and control system for efficiently reducing the vibration level of seated occupants under low-frequency WBV is demonstrated.
107

Myocardin-related transcription factor A regulates conversion of progenitors to beige adipocytes

Li, Chendi 08 April 2016 (has links)
Thermogenic brown adipose tissue generates heat via mitochondrial uncoupling protein-1 (UCP-1), increases whole-body energy expenditure and may protects against obesity and metabolic disorders. White adipocytes store excess energy in the form of triglycerides. UCP-1 positive adipocytes develop within white adipose tissue (beige or brite adipocytes) in response to cold exposure or β3 adrenergic agonists. It was known that beige adipocytes arise from a distinct lineage compared with brown adipocytes, but the developmental origin of the beige adipocytes is still unclear. Signaling pathways that control beige adipocyte determination and formation are essentially unknown. Here, we identified a novel signaling pathway that regulates the lineage specification of beige adipocytes. Bone morphogenetic protein 7 (BMP7), a known brown adipogenesis inducer, suppresses Rho-GTPase kinase (ROCK) and depolymerizes F-actin (filamentous actin) into G-actin (globular actin) in mesenchymal stem cells. G-actin regulates myocardin-related transcription factor A (MRTFA) that co-transactivates serum response factor (SRF) and promotes smooth muscle cell differentiation in various organs. Subcutaneous white adipose tissue from MRTFA-/- mice had enhanced accumulation of UCP-1+ adipocytes and elevated levels of brown-selective proteins. Compared with wild type (WT) controls, MRTFA-/- mice exhibited improved metabolic profiles and were protected from diet-induced obesity and insulin resistance, suggesting that the beige adipocytes are physiologically functional. Compared to WT mice, stromal vascular cells from MRTFA-/- mice expressed higher levels of distinct beige progenitor markers and reduced levels of smooth muscle markers. Our studies demonstrate a novel ROCK-actin-MRTFA/SRF pathway that contributes to the development of beige adipocytes.
108

The benefits of a plant-based diet for the prevention and treatment of heart disease

Dignan, Corynne Jocelyn 22 January 2016 (has links)
Heart disease is still the number one killer in the United States. Recent research has suggested that adhering to a plant-based diet can prevent, treat, and reverse heart disease. In order to further clarify these findings, an analysis was made of the components of a plant-based diet and such dietary effects in relation to being a possible treatment for heart disease. Based on a comprehensive investigation of this area of study, an extensive body of evidence supports the finding that a whole-food, plant-based diet can significantly lower the risk of heart disease, mainly by reducing blood levels of lipids and cholesterol associated with atherosclerosis. Comparison was made between the efficacy of the plant-based diet versus more conventional approaches such as medication and surgery. Further clinical trials are needed to validate the findings of adopting this diet in the prevention and treatment of heart disease.
109

Cellular properties of the medial entorhinal cortex as possible mechanisms of spatial processing

Shay, Christopher Frank 08 April 2016 (has links)
Cells of the rodent medial entorhinal cortex (EC) possess cellular properties hypothesized to underlie the spatially periodic firing behaviors of 'grid cells' (GC) observed in vivo. Computational models have simulated experimental GC data, but a consensus as to what mechanism(s) generate GC properties has not been reached. Using whole cell patch-clamp and computational modeling techniques this thesis investigates resonance, rebound spiking and persistent spiking properties of medial EC cells to test potential mechanisms generating GC firing. The first experiment tested the voltage dependence of resonance frequency in layer II medial EC stellate cells. Some GC models use interference between velocity-controlled oscillators to generate GCs. These interference mechanisms work best with a linear relationship between voltage and resonance frequency. Experimental results showed resonance frequency decreased linearly with membrane potential depolarization, suggesting resonance properties could support the generation of GCs. Resonance appeared in medial EC but not lateral EC consistent with location of GCs. The second experiment tested predictions of a recent network model that generates GCs using medial EC stellate cell resonance and rebound spiking properties. Sinusoidal oscillations superimposed with hyperpolarizing currents were delivered to layer II stellate cells. Results showed that relative to the sinusoid, a limited phase range of hyperpolarizing inputs elicited rebound spikes, and the phase range of rebound spikes was even narrower. Tuning model parameters of the stellate cell population to match experimental rebound spiking properties resulted in GC spatial periodicity, suggesting resonance and rebound spiking are viable mechanisms for GC generation. The third experiment tested whether short duration current inputs can induce persistent firing and afterdepolarization in layer V pyramidal cells. During muscarinic acetylcholine receptor activation 1-2 second long current injections have been shown to induce persistent firing in EC principal cells. Persistent firing may underlie working memory performance and has been used to model GCs. However, input stimuli during working memory and navigation may be much shorter than 1-2 seconds. Data showed that input durations of 10, 50 and 100 ms could elicit persistent firing, and revealed time courses and amplitude of afterdepolarization that could contribute to GC firing or maintenance of working memory.
110

Hur Engelskalärare använder autentiskt material under Engelsklektioner i årskurs nio / How English teachers use authentic material in the English classroom in year nine

Larsson, Fredrik January 2010 (has links)
BAKGRUND:Jag har skrivit om användandet av olika typer av autentiskt material som lärare i engelskaanvänder sig av i sin undervisning i årskurs nio. Detta användande av autentiskt material harjag sedan kopplat till Whole Language-teorin samt aktuell forskning om autentiskt material.SYFTE:Undersökningens syfte är att undersöka vilka autentiska material som används av aktiva lärareoch hur dessa används. Ett vidare syfte är att på en hemsida samla de tips och råd som jagerhållit för att vidarebefordra till lärare som använder autentiskt material i sinengelskundervisning.METOD:Jag har använt mig av ostrukturerade kvalitativa intervjuer för att samla in data.RESULTAT:Lärarna som jag intervjuat, vilka alla var positiva till att använda autentiskt material, visadepå att en stor variation av aktiviteter med olika typer av material som användes. Gemensamtvar att autentiskt material användes för att göra undervisning mer omväxlande och roligt,vilket stämmer bra överens med huvudtankarna i Whole Language-teorin.

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