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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.
21

International financial crises, term structure of foreign debt and monetary policy in open economies

Caliskan, Ahmet 16 August 2006 (has links)
In this dissertation, I study international financial crises. For this purpose, I build two models. In the first model, I focus on financial crises in developing, large open economies where foreign debt with various maturities and issue dates is available. The objective is to measure the vulnerability of the domestic financial system to domestically triggered bank runs and externally triggered sudden stops. The main contribution of this model is that both types of crises are treated as rational responses of domestic depositors and international creditors. Such vulnerability measures are linked to fundamentals and equilibrium term structure of foreign debt. Banks’ vulnerability to runs increases if they hold a relatively shorter term debt. Also, a larger cost of liquidating the long-term investment before maturity makes the banks more fragile. In the next step, given a domestic banking crisis, I allow international creditors to decide whether they want to stop lending to domestic banks (in which case a “sudden stop” takes place) or not. A sudden stop is more likely if (i) creditors highly discount future consumption, (ii) creditors’ current income is small relative to their future income, and (iii) the cost of liquidating the long-term investment before maturity is small. In the second model, I investigate the merits of alternative monetary policies with respect to financial fragility. In this monetary model of an explicit financial system, I motivate the demand for two fiat currencies by spatial separation and limited communication of agents. There is a domestic and a foreign currency freely traded without restrictions. I analyze the policy of a constant growth rate of domestic money supply with a floating exchange rate regime. Both currencies are held in positive amounts at the steady-state only if the growth rate of domestic money supply is equal to the world inflation rate (WIR). If the former rate is larger than the WIR, domestic currency is not held at the steady-state. Also, total real money balances held is negatively related with WIR. Finally, monetary policy in the form of a constant growth rate of domestic money supply is neutral with respect to welfare.
22

Performance based design of degrading structures

Chenouda, Mouchir 01 June 2006 (has links)
Seismic code provisions are now adopting performance-based methodologies, where structures are designed to satisfy multiple performance objectives. Most codes rely on approximate methods to predict the desired seismic demand parameters. Most of these methods are based on simple SDOF models, and do not take into account neither MDOF nor degradation effects, which are major factors influencing structural behavior under earthquake excitations. More importantly, most of these models can not predict collapse explicitly under severe seismic loads. This research presents a newly developed model that incorporates degradation effects into seismic analysis of structures. A new energy-based approach is used to define several types of degradation effects. The research presents also an evaluation of the collapse potential of degrading SDOF and MDOF structures. Collapse under severe seismic excitations, which is typically due to the formation of structures mechanisms amplified by P-Delt a effects, was modeled in this work through the degrading hysteretic structural behavior along with P-Delta effects due to gravity loads. The model was used to conduct extensive statistical dynamic analysis of different structural systems subjected to a large set of recent earthquake records. To perform this task, finite element models of a series of generic SDOF and MDOF structures were developed. The degrading hysteretic structural behavior along with P-Delta effects due to gravity loads proved to successfully replicate explicit collapse. For each structure, collapse was investigated and inelastic displacement ratios curves were developed in case collapse doesn't occur. Furthermore, seismic fragility curves for a collapse criterion were also developed. In general, seismic fragility of a system describes the probability of the system to reach or exceed different degrees of damage. Earlier work focused on developing seismic fragility curves of systems for several values of a calibrated damage index. This research work focuses on developing seismic fragility curves for a collapse criterion, in an explicit form. The newly developed fragility curves represent a major advancement over damage index-based fragility curves in assessing the collapse potential of structures subject to severe seismic excitations. The research findings provide necessary information for the design evaluation phase of a performance-based earthquake design process.
23

Seismic Fragility Analysis and Loss Estimation for Concrete Structures

Bai, Jong Wha 2011 December 1900 (has links)
The main objective of this study is to develop a methodology to assess seismic vulnerability of concrete structures and to estimate direct losses related to structural damage due to future seismic events. This dissertation contains several important components including development of more detailed demand models to enhance accuracy of fragility relationships and development of a damage assessment framework to account for uncertainties. This study focuses on concrete structures in the Mid-America region where a substantial seismic risk exists with potential high intensity earthquakes in this geographic region. The most common types of concrete structures in this area are identified based on the building inventory data and reinforced concrete (RC) frame buildings and tilt-up concrete buildings are selected as case study buildings for further analysis. Using synthetic ground motion records, the structural behavior of the representative case study buildings is analyzed through nonlinear time history analyses. The seismic performance of the case study buildings is evaluated to describe the structural behavior under ground motions. Using more detailed demand models and the corresponding capacity limits, analytical fragility curves are developed based on appropriate failure mechanisms for different structural parameters including different RC frame building heights and different aspect ratios for tilt-up concrete structures. A probabilistic methodology is used to estimate the seismic vulnerability of the case study buildings reflecting the uncertainties in the structural demand and capacity, analytical modeling, and the information used for structural loss estimation. To estimate structural losses, a set of damage states and the corresponding probabilistic framework to map the fragility and the damage state are proposed. Finally, scenario-based assessments are conducted to demonstrate the proposed methodology. Results show that the proposed methodology is successful to evaluate seismic vulnerability of concrete structures and effective in quantifying the uncertainties in the loss estimation process.
24

Application of Hybrid Simulation to Fragility Assessment of Self-centering Energy Dissipative (SCED) Bracing System

Kammula, Viswanath 05 September 2013 (has links)
Substructure hybrid simulation has been actively investigated in recent years. The simulation method allows for the assessment of seismic performance of structures by representing critical components with physical specimens and the rest of the structure with numerical models. In this study the system level performance of a six-storey structure with self-centering energy dissipative (SCED) braces was validated through pseudo dynamic (PsD) hybrid simulation. Fragility curves are derived for the SCED system. The study presents the configuration of the hybrid simulation and discusses some of the practical intricacies in performing PsD hybrid simulations. In addition the study addresses some of the challenges associated with the substructuring process during a hybrid simulation. Two techniques, extensive analytical study and model updation, are discussed to improve the response from the hybrid simulation accounting for the variation in global response of a structural system depending on which structural element was represented as a physical specimen.
25

Application of Hybrid Simulation to Fragility Assessment of Self-centering Energy Dissipative (SCED) Bracing System

Kammula, Viswanath 05 September 2013 (has links)
Substructure hybrid simulation has been actively investigated in recent years. The simulation method allows for the assessment of seismic performance of structures by representing critical components with physical specimens and the rest of the structure with numerical models. In this study the system level performance of a six-storey structure with self-centering energy dissipative (SCED) braces was validated through pseudo dynamic (PsD) hybrid simulation. Fragility curves are derived for the SCED system. The study presents the configuration of the hybrid simulation and discusses some of the practical intricacies in performing PsD hybrid simulations. In addition the study addresses some of the challenges associated with the substructuring process during a hybrid simulation. Two techniques, extensive analytical study and model updation, are discussed to improve the response from the hybrid simulation accounting for the variation in global response of a structural system depending on which structural element was represented as a physical specimen.
26

Os compartimentos da paisagem e a elaboração de uma matriz para o planejamento ambiental em uma bacia hidrográfica com uso intensivo da agricultura: bacia hidrográfica do Ribeirão Santa Gertrudes, Veríssimo-MG / Landscape compartments and elaboration of a matrix for environmental planning in a watershed with intensive agriculture: the Santa Gertrudes Creek, Veríssimo, MG

Campos, Carlos Alberto Araujo [UNESP] 25 July 2017 (has links)
Submitted by Carlos Alberto Araujo Campos Campos (carloscampos@geografia.uftm.edu.br) on 2017-08-21T10:55:27Z No. of bitstreams: 1 Tese_Carlos_Alberto_Araujo_Campos.pdf: 7726332 bytes, checksum: cc8e3b7058c2b0eb5a0d864e71520509 (MD5) / Approved for entry into archive by Monique Sasaki (sayumi_sasaki@hotmail.com) on 2017-08-23T19:54:34Z (GMT) No. of bitstreams: 1 campos_caa_dr_jabo.pdf: 7726332 bytes, checksum: cc8e3b7058c2b0eb5a0d864e71520509 (MD5) / Made available in DSpace on 2017-08-23T19:54:34Z (GMT). No. of bitstreams: 1 campos_caa_dr_jabo.pdf: 7726332 bytes, checksum: cc8e3b7058c2b0eb5a0d864e71520509 (MD5) Previous issue date: 2017-07-25 / Os aspectos pertinentes ao uso dos recursos ofertados pelo meio natural têm sido alvo de diferentes abordagens, seja pela necessidade de aproveitamento ou pelas limitações à sua captação pelo homem. Sendo os elementos que compõem o meio físico passiveis de análises mais apuradas quanto ao seu manuseio, envolvendo técnicas que reduzam os impactos gerados pela sua exploração direta e indireta. A espacialização das informações obtidas de forma direta ou indireta, acerca dos recursos ofertados pelo meio físico, representa uma possibilidade de interação entre as fontes fornecedoras de recursos naturais e sua localização, sendo essa passível de ser mapeada e circunscrita na superfície terrestre. Essa espacialização gera uma poderosa ferramenta de gestão e planejamento das atividades antrópicas. A delimitação de compartimentos da paisagem a partir de unidades do modelado do relevo apresentou resultados satisfatórios quanto as estabilidades dos compartimentos analisados. Assim, a delimitação de compartimentos da paisagem na bacia hidrográfica do ribeirão Santa Gertrudes que se localiza entre os munícipios de Uberaba e Veríssimo, na região do Triângulo Mineiro no estado de Minas Gerais, com 321 Km2 de área e é tributária da margem direita do rio Uberaba, teve como proposta buscar, analisar e compreender a dinâmica interna da mesma e suas alterações em função da ocupação antrópica e das atividades decorrentes dessa forma de ocupação. O objetivo deste trabalho, foi determinar compartimentos da paisagem a partir do mapeamento de unidades do modelado do relevo. Os compartimentos subsidiaram a elaboração dos mapeamentos de áreas com fragilidades e potencialidades ambientais. Para tanto, foram elaborados mapas geológicos, geomorfológicos, de declividades e usos dos solos, realizados testes de infiltração e análise granulométrica dos solos. Com o uso do sistema de informações geográficas, as informações foram espacializadas em mapas temáticos e o cruzamento dos mesmos dentro de um sistema de multicritérios, permitiu a elaboração dos mapas de potencialidades e fragilidades ambientais. O uso de compartimentos da paisagem a partir de unidades do modelado do relevo, permitiu a elaboração de uma matriz ambiental para o uso dos solos, apontando suas potencialidades e fragilidades de ocupação. Os resultados foram bem satisfatórios no que tange ao diagnóstico da bacia hidrográfica, que permitiu uma visão mais pontual e espacialização de informações, acerca do que ocorre em seu interior. Esse entendimento do comportamento natural de uma bacia hidrográfica, gera parâmetros comparativos, para entendimento das alterações que a sua ocupação pode levar, seja nos aspectos relacionados aos solos e seus usos, vegetação, escoamento superficial, contaminação dos solos e corpos hídricos superficiais e subsuperficiais. / Relevant aspects of the use of resources offered by the natural environment have been the subject of different approaches, either the need for exploitation or the limitations of uptake by man. The elements that compound the physical environment are subject of more accurate analysis regarding handling, involving techniques that reduce the impacts generated by your direct and indirect exploitation. The spatialization of information obtained directly or indirectly about the resources offered by the physical environment, what represents a possibility of interaction between the natural resources sources and location to be mapped and circumscribed on the Earth's surface. This spatialization generates a powerful management and planning tool of human activities. The Santa Gertrudes Creek watershed is located between the municipalities of Uberaba and Veríssimo, in the State of Minas Gerais, with 321 Km2 of area and is a right tributary of Uberaba River. It was proposed to search, analyze and understand the internal dynamics of the watershed and its changes as a function of human occupation and activities resulting from this form of occupation. The use of landscapes compartments from relief units enabled the development of an environmental matrix for land use, pointing potentialities and weaknesses. The aim of this work was the preparation of landscape compartments from the mapping of relief units, what subsidized the elaboration of maps of environmental potentialities and weaknesses for the watershed under study. To do so, maps of geology, slope, geomorphology, and land use have been drawn up and infiltration tests and particle size analysis of soils were performed. It is worth noting, that by using a geographic information system, the information was spatialized in thematic maps and the crossing of them within a multicriteria system allowed the elaboration of maps of environmental potentialities and weaknesses. The results were quite satisfactory with regard to the diagnosis of the watershed, which allowed a more punctual visualization and spatialization of information about what occurs in the area. This understanding of the natural behavior of a watershed generates comparative parameters for understanding the changes that human occupation can take in aspects related to soils, vegetation, runoff, soil contamination and surface and sub-surface water bodies.
27

Velocidade da marcha, quedas, medo de cair e capacidade funcional em idosos da comunidade : dados do FIBRA / Speed of walking, falls, fear of falling and functional ability in older community : data from FIBRA

Rodrigues, Iara Guimarães, 1984- 10 February 2009 (has links)
Orientador: Regina Maria Innocencio Ruscalleda / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-08-14T18:06:29Z (GMT). No. of bitstreams: 1 Rodrigues_IaraGuimaraes_M.pdf: 2544338 bytes, checksum: bdac7f99ac4abc0e0fc23e7cf8a9801b (MD5) Previous issue date: 2009 / Resumo: Objetivo: Investigar o perfil dos idosos da comunidade de Campinas, classificados segundo o nível de condição de vida do bairro onde residem, quanto a gênero, idade, velocidade da marcha, ocorrência de quedas no ultimo ano, medo de cair e desempenho em Atividades Avançadas de Vida Diária (AAVDs). Participantes: Fizeram parte deste Estudo 264 idosos com 65 anos ou mais, recrutados em domicilio, em setores censitários urbanos pertencentes a áreas de abrangência de Centros de Saúde classificados pelo Índice de Condições de Vida, um indicador de vulnerabilidade social Procedimentos: Os dados faziam parte do banco eletrônico de uma pesquisa populacional e foram coletados por instrumentos de auto-relato, com exceção da medida de marcha que foi coletada por teste de execução Resultados: 71,21% eram mulheres; 72,73% não referiram quedas no ultimo ano; 57,58% referiram medo de cair; 62,50% obtiveram uma media velocidade da marcha e 66,70% eram independentes para as AAVDs. As mulheres tiveram um numero de quedas significantemente mais alto do que os homens e também mais medo de cair. As AAVDs mais freqüentemente realizadas pelos idosos dizem respeito a sociabilidade desempenhada em casa e na igreja e as menos desempenhadas são relativas a participação em instituições de lazer e de educação para idosos. O indicador de baixo ICV apareceu significativamente associado com menor funcionalidade em AAVDs. Conclusão: A maioria dos sujeitos da pesquisa não relatou quedas no ultimo ano, porem relataram medo de cair. Observou-se uma ocorrência significativa de quedas, medo de cair e maior lentidão da marcha no sexo feminino, embora exista uma tendência das mulheres realizarem em media um percentual maior das AAVDs em relação aos homens. Idosos pertencentes ao grupo de alto ICV obtiveram melhor desempenho da marcha e aqueles com baixo ICV apareceram significativamente associados com uma menor funcionalidade em AAVDs, confirmando nossa hipótese de estudo. Contudo, estudar o perfil dos idosos de uma comunidade, pode alem de demonstrar a necessidade de intervenções, contribuir nos planejamentos de políticas publicas / Abstract: Objective: To investigate the profile of the elderly community of Campinas, classified by level of living conditions in the district where they reside, in terms of gender, age, speed of walking, with falls last year, fear of falling and performance in Advanced Activities of Daily Living (AAVDs). Participants: Participants were 264 elderly people aged 65 years or older, recruited in their residence in census tracts belonging covering areas of health centers classified by the Index of Living Conditions, an indicator of social vulnerability Procedures: The data were part of electronic banking population survey were collected and given to self-report, except the measure of progress which was collected by running test. Results: 71.21% were women, 72.73% did not report falls in the previous year; 57.58% reported fear of falling; 62.50% had an average speed of walking and 66.70% were independent for AAVDs. Women had a number of falls significantly higher than men and also more afraid of falling. The AAVDs most often done by older people relate to sociability played at home and at church and performed less are associated with participation in institutions of education and leisure for the elderly. The indicator of low ICV appeared significantly associated with less functionality in AAVDs. Conclusion: Most of the research subjects reported no falls in the last year, but reported fear of falling. There was a significant occurrence of falls, fear of falling and slower speed of walking in women, although there is a tendency for women making on average a higher percentage of AAVDs with men. Seniors in the group of high ICV showed a better performance of motion and those with low ICV appeared significantly associated with functionality in AAVDs, confirming our hypothesis of the study. However, studying the profile of the elderly in a community, can also demonstrate the need for interventions, help in the planning of public politics / Mestrado / Mestre em Gerontologia
28

Geomorfologia, geodiversidade e análise da fragilidade ambiental das paisagens do parque estadual Serra Ricardo Franco, MT-Brasil / Geomorphology, geodiversity and analyses of environmental fragility of the landscapes of the State Park Serra Ricardo Franco, MT Brazil

Ana Rosa Ferreira 17 December 2014 (has links)
Mato Grosso encontra-se em acelerado processo de desenvolvimento do agronegócio, expandindo cada vez mais suas fronteiras agrícolas. Por outro lado, amplia a criação de áreas de conservação ambiental sendo elas estaduais ou municipais. A concepção de proteção da flora, fauna e de recursos hídricos, manejo de recursos naturais, desenvolvimento de pesquisas científicas, manutenção do equilíbrio climático e ecológico e preservação de recursos genéticos, representa um importante instrumento para a sobrevivência de muitas espécies, inclusive a humana e contribuem para a criação dessas Unidades de Conservação. A região do Parque Estadual da Serra de Ricardo Franco, localizado no município de Vila Vela da Santíssima Trindade, mesmo abrigando grande riqueza da biodiversidade, não possui nenhuma infra-estrutura de gestão do parque que vise o combate a exploração da terra, invasão por grileiros e posseiros, desmatamentos e queimadas. Diante do exposto, essa pesquisa tem como objetivo principal avaliar e analisar a situação atual e importância da geodiversidade (geomorfologia, solos, geologia, clima), da biodiversidade (a cobertura vegetal), por meio principalmente do componente geomorfológicos, para o estudo e determinação da fragilidade da paisagem como subsídio ao planejamento ambiental do referido parque. Dessa forma, a partir dessa avaliação e análise, propor ações de recuperação e restauração dos recursos hídricos, edáficos, e dos ecossistemas degradados. No desenvolvimento desta pesquisa, aplicou-se uma metodologia de estudo que englobou os estudos de geodiversidade, compartimentação geomorfológica, dissecação e declividade do relevo, pedologia, uso do solo e cobertura vegetal e precipitação pluviométrica como subsídios para a produção da carta de fragilidade potencial da região. As cartas com dados geomorfológicos, geológicos e pedológicos foram confeccionados a partir da base de dados de cartas disponíveis pelo IBGE/DSG, CPRM e pela SEPLAN/MT, na escala de 1:1.000.000; 1:500.000, 1::250.000; 1:100.000 e 1:50.000, atualizadas com dados de imagens LANDAST 5 TM de 1993 a 1955 e 2005 a 2011, sendo as Folhas SD -20 Z B e SD 20 Z D/SE 20 X B, Mapa 001 MIR 369 e 385/401 as que demonstram o território do Parque Estadual Serra Ricardo Franco. Os resultados obtidos demonstram um relativo equilíbrio ambiental, que ocorre em função dos fatores naturais e pela forma de uso do solo do interior do Parque. Entretanto, os problemas fundiários do entorno do Parque se não forem legalizados, poderão ocasionar sérios problemas ambientais na região. Nesse sentido, torna-se necessário algumas ações de planejamento e gestão ambiental e territorial no intuito de preservar as áreas ainda conservadas. A hierarquização da área conforme as classes de fragilidade potencial, associadas às análises realizadas na presente pesquisa, constituem-se em ferramenta para orientar na definição de planos de recuperação, planejamento e zoneamento territorial e ambiental do Parque Estadual Serra Ricardo Franco, inserido em uma região de grande importância geoecológica, econômica e social do Estado de Mato Grosso. Diante do exposto fica explícito que a escolha da área do Parque Estadual Serra Ricardo Franco se deve aos seus aspectos naturais, destacando a compartimentação do relevo e da zona de ecótono entre o bioma Amazônico, o Cerrado e o Pantanal do Guaporé. / Mato Grosso is experiencing rapid growth in agribusiness, expanding the state\'s agricultural frontiers even farther. On the other hand, state and municipal environmental preservation areas are also expanding. The concept of preserving the flora, fauna and water resources, management natural resources, developing scientific research, maintenance of climatic and ecological balance and preservation of genetic resources represents an important tool for the survival of many species, including humankind, and contributes to the creation of these Conservation Units. The region of Serra de Ricardo Franco State Park, located in the municipality of Vila Vela da Santíssima Trindade, despite its rich biodiversity, presents no infrastructure aimed at fighting land exploitation, invasion by encroachers and squatters, deforestations and bush fires. In view of the above considerations, this research seeks to evaluate and analyze the current status and importance of biodiversity (geomorphology, soils, geology and climate), biodiversity (vegetal cover), mainly through the geomorphological components in order to study and determine the fragility of the landscape so as to support the environmental planning of the said park. Thus, from this evaluation and analysis, we propose actions to recover and restore water and edaphic resources of the degraded ecosystems. In the development of this research, we applied the methodology comprising studies on geodiversity, geomorphological compartimentation, relief dissection and declivity, pedology, soil use and vegetal cover and rainfall as subsidies for the production of the potential fragility letter of the region. The letters with geomorphological, geological and pedological data were prepared based on the letters database made available by the Brazilian Institute of Geography and Statistics (IBGE/DSG), the Geological Survey of Brazil (CPRM) and the Secretariat for Regional Planning and Development of the State of Mato Grosso (SEPLAN/MT), in scales of 1:1.000,000; 1:500,000, 1:250,000; 1:100,000 e 1:50,000, updated with LANDAST 5image data TM from 1993 to 1955 and 2005 to 2011, with pages SD -20 Z B and SD 20 Z D/SE 20 X B, Map 001 MIR 369 and 385/401 displaying the territory of Serra de Ricardo Franco State Park. The results obtained suggest relative environmental balance as a result of natural factors and the form of soil use in the interior of the park. However, land title problems surrounding the Park have not been legalized and may cause serious environmental problems in the region. Therefore, some environmental and territorial planning and management actions are needed to protect the areas currently preserved. Ranking the area according with potential fragility classes, in addition to the analyses carried out in this research, may help define recovery, planning and territorial and environmental zoning plans of Serra de Ricardo Franco State Park, a region of great geo-ecological, economic and social significance for the State of Mato Grosso. Based on the above considerations, we have made explicit that the choice of the area of Serra de Ricardo Franco State Park is due to its natural features, mainly relief compartimentation and the ecotone zone between the Amazon biome, the Cerrado and Pantanal do Guaporé.
29

The clinical characteristics, complications and treatment outcomes of patients with osteoporosis at Groote Schuur Hospital

Abdelfadiel, Omer Alawad Homaida 13 July 2021 (has links)
Background: Osteoporosis has become a major problem worldwide as the population ages. An osteoporotic fracture is associated with a high rate of morbidity and mortality. Data on the prevalence, risk factors and outcome of osteoporotic fractures in South Africa remains sparse. Method: A retrospective audit was undertaken in all patients attending the Endocrine Clinic at Groote Schuur Hospital between March 2019 and March 2020 for the treatment of osteoporosis. Patients folders were reviewed to obtain the following information: demographic data, risk factors, laboratory investigations, treatment, baseline and follow up DEXA scans. Results: 264 patients were evaluated, average age 65.7 ± 12.3 years, 92.8% (n=245) were female. Common risk factors included smoking (50.8%, n=134), vitamin D deficiency (29.2%, n=77), steroid use (21.6%, n=57) and primary hyperparathyroidism (15.2%, n=40). A fragility fracture was diagnosed in 68.6% (n=181) - vertebral only (54.7%, n=99), hip only (14.9%, n=27), vertebral and hip (10.5%, n=19), wrist (7.2%, n=13) and other (12.7%, n=23). Bisphosphonates were used by 75% (n=198) of patients at the time of enrolment. Of these, 80.8% (n=160) received intravenous zoledonic acid alone, 6.1% (n=12) received oral alendronate alone and 13.1% (n=26) initially received alendronate followed by intravenous zoledronic acid. Over 5.2 years there was an improvement in bone mineral density (BMD) of 4.4% at the lumbar spine, while there was slight worsening of BMD at the femoral neck (- 0.17%). A fracture whilst on treatment occurred in 10.6% (n=21) of patients. Conclusion: The majority of patients with osteoporosis at Groote Schuur Hospital had a fragility fracture at diagnosis with a vertebral fracture being most common. Bisphosphonate treatment showed a measurable improvement in BMD at the lumbar spine, however, there was no improvement at the femoral neck. Despite this, few patients had a symptomatic vertebral or hip fracture whilst on treatment.
30

Mathematical Modeling of the Osmotic Fragility of Rabbit Red Blood Cells

Orcutt, Ronald H., Thurmond, T. Scott, Ferslew, Kenneth E. 01 January 1995 (has links)
The osmotic fragility (OF) test is used to determine the extent of red blood cell hemolysis (RBCH) produced by osmotic stress. RBCH is dependent upon cell volume, surface area, and functional integrity of cell membranes. The variation of cell lysis with stress reflects underlying cell subpopulations and their membranes' cytoskeletal functionality. OF was determined on blood from New Zealand white rabbits. The dependence of RBCH on NaCl concentration ([NaCl]) was determined spectrophotometrically by measuring absorbance (Abs) from hemoglobin release at 545 nm. Abs data were fitted to the equation Abs = p3 erfc( ([NaCl] - p1) p2) where p3 reflects maximum RBCH, p1 measures the [NaCl] at 50% RBCH, and p2 shows the dispersion in [NaCl] producing the RBCH. Parameter values for control blood were p1 = 0.4489 ± 0.0016; p2 = 0.0486 ± 0.0016; and p3 = 0.4366 ± 0.0022. Addition of indomethacin (9.6 μg/mL) produced an increased fragility in the RBC's characterized by increased values of p1 and p2. Normalization of the data to p3 did not change the values of p1 or p2. Our equation satisfactorily describes the variation in RBCH as a function of [NaCl]. The parameters of the equation can be used to quantitatively characterize Abs/[NaCl]. The compare pharmacological, Toxicological, and pathological effects on the OF of RBC's.

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