Purpose: To grade cataract changes in a Guatemala population with direct ophthalmoscopy and a grading system based on the grading system used by V. Mehra and D. C. Minassian in 1988. Methods: A population from Guatemala who attended field clinics conducted by Vision For All were included in this study. The sample consisted of 352 participants, 219 women and 133 men, from 9-90 years old. Mean age of the participants was 47.9 ± 17.8 years old. Binocular VA and subjective refraction was obtained with trial lenses and a Snellen E-chart at 5 meters. A 2 mm pinhole was used monocularly with the subjective refraction and whether participants felt any improvement in VA was documented.  The opacities in the red reflex in the crystalline lens were graded using a handheld direct ophthalmoscope. The grading was made in an angle of 25o nasal and at approximately 33 cm from the participant’s undilated eye. Results: The prevalence of cataract was 28.6% and 68% had some form of opacity in the red reflex. There was no statistically significant difference (p > 0.05) between the grade of lens opacities in right and left eye. Mean grade of lens opacities in right eye was 1.64 ± 1.46 and 1.63 ± 1.43 in left eye. The analysis showed a highly significant correlation between age and grade of lens opacities in right eye (y = 0.0657x -1.5106; r = 0.8; p < 0.001) and left eye (r = 0.78; p < 0.001). Lens opacities start to develop at an average age of 38.5 years in this population. There was a significant correlation between aided VA and grade of lens opacities for right eye (r = 0.52; p < 0.05) and left eye (r = 0.49; p < 0.05). 72 participants (20.5%) who had grading 3-5 in one or both eyes felt an improvement in their vision with the pinhole. Conclusions: The prevalence of cataract was 28.6% and this population had an earlier development of cataract compared to previous studies. This could be due to the UV-radiation, the temperature and nutrition and antioxidant insufficiency. Also this study showed a highly significant correlation between age and grade of lens opacities and a low, but significant, correlation between aided VA and grade of lens opacities.

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Thesis (Ph. D.)--University of Texas at Austin, 2003. / Vita. Includes bibliographical references.

In the face of tightened loans from commercial banks, skyrocketing interest rates, reduced export demand, and weak domestic industries, the countries of the Andean Community (Ancom) turned their eyes, in the early 1990s, to the promise of FOI. Paradoxically, despite the success of the incentives put in place to attract FOI, Ancom failed to attract the sought after technology flows that would assist them in diversifying their exports, strengthening their industry, and retaining a higher portion of the value-added activities in the production chain. FOI was mainly directed to economic sectors entailing enclave-type activities with weak linkages to the rest of the economy as well as often low levels of local processing of resources, unstable international prices, low tax income for non-renewable resources, and environmental contamination. The aim of this thesis is to investigate, first, what are the historical sector-level FOI patterns of inward FOI in Ancom; and second, what are their determinants. In particular, we explore the role that local political and civil institutions play in determining inward FOI, and whether this role varies from one sector to another. We present a newly compiled dataset of inward FDI stocks, disaggregated by eight welldefined economic sectors within each country. The contributions of this dataset are, first, unprecedented time coverage, extending for an entire extra decade, the 1980s, for the countries of Colombia and Peru, for every disaggregated economic sector; second, the presentation of previously unpublished FDI stock data for the Colombian oil and petroleum sector; and third, the reorganisation of the existing individual country datasets into a comprehensive regional dataset. The outcome is the creation of the strongest available statistical foundation, based on published as well as unpublished figures from official sources. From an econometric perspective our analysis uses techniques that allow exploring nonstationary processes such as the analysis of stochastic and time trends, cointegration, and vector-error-correction models. Key findings include the importance of the quality of the institutional quality of a country in determining the industrial structure of inward FOI. Furthermore, we find that institutions are multidimensional and, as such, changes in the quality of different institutions often play conflicting roles in determining sector-level FDI. In the sectors of: Mining, Utilities, and Communications and Transport, FDI is associated with low levels of political rights, and high levels of civil liberties, whilst, the opposite holds for FOI in Agriculture, Manufacturing , Construction, Finance and Oil/Petroleum. Market size and trade openness are found to be important determinant in most sectors, whilst wages are either insignificant or inversely related to FOI. We also examine, from a historical perspective, the political economy surrounding changes in FOI policy as well as the evolving FDI trends, made available by the new dataset. We find, on the one hand, that the degree of political sensitivity to liberalisation, at sector-level, determines the availability and contract-modality of opportunities for foreign investors. On the other hand, geographical characteristics of each sector determine the type of political environment that is most conducive to increases in FDI. For this purpose we propose an extension of the definition of key geographical characteristics. We present an original framework, matching the two dimensions of sector-level characteristics to FDI contractmodality and political-conducive environment to increased FDI.

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A large direct numerical simulation database spanning a wide range of Reynolds and Schmidt number is used to examine fundamental laws governing passive scalar mixing and turbulence structure. Efficient parallel algorithms have been developed to calculate quantities useful in examining the Kolmogorov small-scale phenomenology. These new algorithms are used to analyze data sets with Taylor scale Reynolds numbers as high as 650 with grid-spacing as small as the Kolmogrov length scale. Direct numerical simulation codes using pseudo-spectral methods typically use transpose based three-dimensional (3D) Fast Fourier Transforms (FFT). The ALLTOALL type routines to perform global transposes have a quadratic dependence on message size and typically show limited scaling at very large problem sizes. A hybrid MPI/OpenMP 3D FFT kernel has been developed that divides the work among the threads and schedules them in a pipelined fashion. All threads perform the communication, although not concurrently, with the aim of minimizing thread-idling time and increasing the overlap between communication and computation. The new algorithm is seen to reduce the communication time by as much as 30% at large core-counts, as compared to pure-MPI communication. Turbulent mixing is important in a wide range of fields ranging from combustion to cosmology. Schmidt numbers range from O(1) to O(0.01) in these applications. The Schmidt number dependence of the second-order scalar structure function and the applicability of the so-called Yaglomﾒs relation is examined in isotropic turbulence with a uniform mean scalar gradient. At the moderate Reynolds numbers currently achievable, the dynamics of strongly diffusive scalars is inherently different from moderately diffusive Schmidt numbers. Results at Schmidt number as low as 1/2048 show that the range of scales in the scalar field become quite narrow with the distribution of the small-scales approaching a Gaussian shape. A much weaker alignment between velocity gradients and principal strain rates and a strong departure from Yaglomﾒs relation have also been observed. Evaluation of different terms in the scalar structure function budget equation assuming statistical stationarity in time shows that with decreasing Schmidt number, the production and diffusion terms dominate at the intermediate scales possibly leading to non-universal behavior for the low-to-moderate Peclet number regime considered in this study. One of the few exact, non-trivial results in hydrodynamic theory is the so-called Kolmogorov 4/5th law. Agreement for the third order longitudinal structure function with the 4/5 plateau is used to measure the extent of the inertial range, both in experiments and simulations. Direct numerical simulation techniques to obtain the third order structure structure functions typically use component averaging, combined with time averaging over multiple eddy-turnover times. However, anisotropic large scale effects tend to limit the inertial range with significant variance in the components of the structure functions in the intermediate scale ranges along the Cartesian directions. The net result is that the asymptotic 4/5 plateau is not attained. Motivated by recent theoretical developments we present an efficient parallel algorithm to compute spherical averages in a periodic domain. The spherically averaged third-order structure function is shown to attain the K41 plateau in time-local fashion, which decreases the need for running direct numerical simulations for multiple eddy-turnover times. It is well known that the intermittent character of the energy dissipation rate leads to discrepancies between experiments and theory in calculating higher order moments of velocity increments. As a correction, the use of three-dimensional local averages has been proposed in the literature. Kolmogorov used the local 3D averaged dissipation rate to propose a refined similarity theory. An algorithm to calculate 3D local averages has been developed which is shown to scale well up to 32k cores. The algorithm, computes local averages over overlapping regions in space for a range of separation distances, resulting in N^3 samples of the locally averaged dissipation for each averaging length. In light of this new calculation, the refined similarity theory of Kolmogorov is examined using the 3D local averages at high Reynolds number and/or high resolution.

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This work constitutes a study of the operations of local authority building direct labour organisations (DLOs) during the 1980s, An overt aim of Part III of the 1980 Local Government, Planning and Land Act was to improve efficiency in the operations of local authority building direct labour organisations (DLOs). Whilst the Act did not specify how DLOs should be organised, the legislation on accounting and accountability clearly had Important organisational implications. Even prior to 1981, some DLOs already obtained the majority of work via competitive tender, had control over their functions and had systems for demonstrating their efficiency. Others were not operated in such ways and fundamental changes were needed to successfully meet the challenge of the new legislation. By 1988, the Audit Commission admitted that DLO5 had very largely been successful in meeting the competitive requirements of the 1980 Act, but expressed concern over the varying levels of effectiveness and efficiency of operation that existed amongst organisations. An objective of the study is to look at the problems associated with efficiency and productivity measurement in the context of DLO performance. The Conservative government of this period had a strong conniitment to the improvement of efficiency of the public sector. In other areas of public services, various forms of performance Indicator were being employed to monitor performance, but for a DLO the sole measure of efficiency was the ability to meet the 5a target rate of return. The concern with efficiency produced new interest in the application of quantitative techniques to provide methods of efficiency measurement. This work undertakes a study of the problems associated with efficiency and performance measurement In this sector of the U.K. construction Industry. The availability of appropriate data at the Individual organisation level from 1981 onwards, enabled, for the first time, viable lnter-DLO comparisons to be undertaken at the micro-level and sectoral comparisons to be made at the macro-level. The data used In the study were obtained over a five year period from a variety of sources of published and unpublished sources. A unique database of expenditure and revenue Information from over 150 DLOs has been developed, which in many ways is even more comprehensive than the 'official' statistics collected by the Chartered Institute of Public Finance and Accountancy. Methods used for efficiency measurement With the great emphasis placed on ensuring that the public sector of the construction industry acts in an efficient manner, the data are employed In various methods for the measurement of efficiency. 1. At the sector level, total factor productivity neasurement is used to gauge the rate of growth of the DLO sector of the industry. 2. At the organisation level, 'Farrell' measures of efficiency are used. A model for measuring the efficiency of Individual organisations is presented. Data Envelopment Analysis I used to consider inefficiency that raises Costs above their feasible minimum.