FAMILIES OF STREET CHILDREN IN THE TRANSKEI: A DEVELOPMENTAL PERSPECTIVE

In South Africa, as elsewhere in the world, there is a paucity of literature on families of street children. A recent literature search (on the internet and in other resources) reveals that reasons for this state of affairs are many, some of the main ones bein

Doctor of Philosophy

dissertationAlthough Electronic Health Record (EHR) systems have recently achieved widespread adoption in the U.S., our understanding of their impact on care outcomes is still limited. Current literature has produced mixed results due to the use of non-standardized measurements and weak research designs. In this dissertation, 4 studies are conducted to develop a systematic methodology for detecting near real-time performance changes during EHR implementations. It also explores factors that can affect outcomes during a commercial EHR implementation. The first study assesses the current state of the literature on health IT adoption to identify the most commonly reported outcome measures and proposes a taxonomy to classify these measurements. The second study expands the first study by identifying additional measures through semistructured interviews with experienced clinical and administrative leaders from a large care delivery system. We also collect input from national informatics experts who suggested additional relevant measures. The third study is a robust longitudinal analysis including several measures from our larger inventory that were used for monitoring a large-scale commercial EHR implementation and detected patterns of impact and mixed time-sensitive effects across geographically dispersed settings from an integrated care delivery system. The fourth study is a qualitative analysis guided by the quantitative results of the third study. We identified several factors that may have contributed to performance changes detected by our methodology. In summary, this dissertation will help the broader medical and informatics communities by informing what and how to continuously monitor future similar implementations. First, it contributes to the identification of relevant outcomes likely impacted by health IT interventions. Second, it combines these outcome measures with a robust interrupted time-series design, producing a systematic methodology that allows earlier and potentially more precise detection of unexpected effects, and implementation of effective response to mitigate negative impacts. Last, the identification of factors that may impact outcomes during and following an EHR implementation and covariates to measure them will empower researchers in charge of future evaluations, hopefully increasing the understanding of the full impact of health IT interventions

Frequency-modulated comb LIDAR

Frequency-modulated continuous-wave LIDAR (FMCW LIDAR) has been widely used for both scientific and industrial tools. Here, in this report, a new class of LIDAR technique based on an optical frequency comb, named frequency-modulated comb LIDAR (FMcomb LIDAR), is proposed. Instead of using one carrier such as FMCW LIDAR, the multiple carriers from an optical frequency comb are used in FMcomb LIDAR. Because of the correlation between comb modes, each frequency-scanned comb mode can be coherently stitched, thus allowing for a resolution equivalent to scanning by many comb modes while scanning only by the comb mode spacing. In a proof-of-concept experiment, three comb modes from an electro-optic frequency comb (EO comb) are coherently stitched, showing Fourier-transform limited resolution (defined as FWHM linewidth) of 10 ps (i.e., 1.5 mm in air) for about 65 ns delay. The obtained resolution is three-times higher than that of conventional FMCW LIDAR when the same scan range is considered

THE RELATIONSHIP BETWEEN HIV/AIDS AND POVERTY: THE CASE OF THREE ADMINISTRATIVE AREAS IN THE TRANSKEI

The paper is based on on-going research that is conducted under the auspicies of the Department of Social Development, University of Transkei. The findings of this research study, on completion, will highlight the relationship between HIV/AIDS and poverty in the Transkei region of the Eastern Cape

Electro-optic comb based real time ultra-high sensitivity phase noise measurement system for high frequency microwaves

Recent progress in ultra low phase noise microwave generation indispensably depends on ultra low phase noise characterization systems. However, achieving high sensitivity currently relies on time consuming averaging via cross correlation, which sometimes even underestimates phase noise because of residual correlations. Moreover, extending high sensitivity phase noise measurements to microwaves beyond 10 GHz is very difficult because of the lack of suitable high frequency microwave components. In this work, we introduce a delayed self-heterodyne method in conjunction with sensitivity enhancement via the use of higher order comb modes from an electro-optic comb for ultra-high sensitivity phase noise measurements. The method obviates the need for any high frequency RF components and has a frequency measurement range limited only by the bandwidth (100 GHz) of current electro-optic modulators. The estimated noise floor is as low as −133 dBc/Hz, −155 dBc/Hz, −170 dBc/Hz and −171 dBc/Hz without cross correlation at 1 kHz, 10 kHz, 100 kHz and 1 MHz Fourier offset frequency for a 10 GHz carrier, respectively. Moreover, since no cross correlation is necessary, RF oscillator phase noise can be directly suppressed via feedback up to 100 kHz frequency offset