Development and validation of a computational multibody model of the elbow joint

Title from PDF of title page, viewed on March 25, 2014Thesis advisor: Trent M. GuessVitaIncludes bibliographical references (pages 71-78)Thesis (M. S.)--School of Computing and Engineering. University of Missouri--Kansas City, 2013Computational multibody models of the elbow joint can provide a powerful tool to study joint biomechanics, examine muscle and ligament function, soft tissue loading, and the effects of joint trauma. Such models can reduce the cost of expensive experimental testing and can predict some parameters that are difficult to investigate experimentally, such as forces within ligaments and contact forces between cartilage covered bones. These parameters can assist surgeons and other investigators to develop better treatments for elbow injuries and thereby increase patient care. Biomechanical computational models of the elbow exist in the literature, but these models are typically limited in their applicability by artificially constraining the joint (e.g. modeling the elbow as a hinge joint), prescribing specific kinematics, simplifying ligament characteristics or ignoring cartilage geometries. The purpose of this thesis was to develop anatomically correct subject specific computational multibody models of elbow joints and validate these models against experimental data. In these models, the joints were constrained by three-dimensional deformable contacts between articulating geometries, passive muscle loading, and multiple bundles of non-linear ligaments wrapped around the bones. In this approach, three-dimensional bone geometries for the model were constructed from volume images generated by computed tomography (CT) scans obtained from cadaver elbows. The ligaments and triceps tendon were modeled as spring-damper elements with non-linear stiffness. Articular cartilage was represented as uniform thickness solids covering the articulating bone surfaces. Finally, the model was validated by placing the cadaver elbows in a mechanical testing apparatus and comparing predicted kinematics and triceps tendon forces to experimentally measured values. A small improvement in predicted kinematics was observed compared to experimental values when the lateral ulnar collateral and annular ligament were wrapped around the bone. Some reductions of RMS error were also observed when a non-linear toe region was modeled in the ligament compared to models that had only a linear force-displacement relationship. None of these changes were statistically significant (ANOVA p-value was greater than 0.05)Abstract -- List of illustrations -- List of tables -- Acknowledgments -- Introduction -- Background -- Methods and materials -- Results -- Discussion -- Appendix -- Reference

Rural consumers' adoption of CRM in a developing country context

This paper illustrates how understanding consumer preferences through market research may enhance CRM adoption among the rural customers of a developing country like Bangladesh. It presents the case of Community Information Centre (CIC) established by Grameenphone, a company owned by Telenor, the Norwegian telecommunications company and Grameen Bank, the Nobel prize winning micro credit organisation in the rural settings of Bangladesh. The paper shows that CIC is an innovative way of building and maintaining customer relationships and technological interface with the financially constrained consumers in a poor developing economy like Bangladesh

Musculoskeletal Modeling of The Human Elbow Joint

Title from PDF of title page viewed June 8, 2017Dissertation advisor: Antonis P. Stylianou and Majid Bani-YaghoubVitaIncludes bibliographical references (pages 130-139)Thesis (Ph.D.)--School of Computing and Engineering and Department of Mathematics and Statistics. University of Missouri--Kansas City, 2017Comprehensive knowledge of the in vivo loading of elbow structures is essential in understanding the biomechanical causes associated with elbow diseases and injuries, and to find appropriate treatment. Currently, in vivo measurements of ligament, and muscle forces, and cartilage contact pressures during elbow activities is not possible. Therefore, computational models needs to be employed for prediction. A dynamic computational model in which muscle, ligament and articular surface contact forces are predicted concurrently would be the ideal tool for patient specific pre-operative planning, computer aided surgery and rehabilitation. Computational models of the elbow have been developed to study joint behavior, but all of these models have limited applicability because the joint structure was modeled as an idealized joint (e.g. hinge joint) rather than a true anatomical joint. Three dimensional studies of elbow passive motion showed that the elbow does not function as a simple hinge joint. An accurate elbow model should reflect the intrinsic laxity of the elbow especially for clinical applications. Presented here are methods for developing an anatomically based computational model of the human elbow joint that replicates the mechanical behavior of the joint and is capable of concurrent prediction of articular contact, ligament, and muscle forces under dynamic conditions. The model performance was evaluated in both a cadaveric study and a living human subject experiment. The validated models were then used to investigate the effects of medial and lateral collateral ligament deficiency on elbow joint kinematics, ligament loads, and articular contact pressure distribution.Introduction -- Background -- Prediction of elbow joint contact mechanics in the multibody framework -- Lateral collateral ligament deficiency of the elbow joint: a modeling approach -- A modeling approach to simulating medial collateral ligament deficiency of the elbow joint -- Muscle driven elbow joint simulation: a computational approach -- Conclusio

Determinants of Living Arrangements, Health Status and Abuse among Elderly Women: A Study of Rural Naogaon District, Bangladesh

In this study, the socio-economic backdrops, living arrangements, health status and abuse of the women aged 60 years and older in the rural Naogaon district of Bangladesh are examined. The data were collected from seven villages by using probability proportional to size (PPS) sampling and the results show that an overwhelming majority of the elderly women in the age group 60-69 years who are widowed, illiterate, have no education and income, economically dependent, living with married children, unhealthy, suffer from arthritis related illness and are taking treatment from village doctors. Furthermore, the study shows that, nearly 35 percent elderly women are abused, mostly mentally abused due to poverty. Logistic regression analysis reveals the determinants of living arrangements, health status and abuse of the elderly women. The findings of the study should get due attention to provide secured later life of the elder especially female elderly in Bangladesh and developing nation as well

Uptake of climate change adaptation research results in South Asia

Climate Resilience and National Resilience programs focus on formulating the Bangladesh National Adaptation Plan (NAP) for long-term adaptation investments and enhancing the national capacity to integrate climate change adaptation (CCA) in planning, budgeting, and financial tracking process. However, these programs and projects need a system-level quantitative tool to assess the requirement for adaptations at different scales and consequently decide on adaptation financing for these programs and projects. The current project is built on the earlier findings of the DECCMA project to address the above issues, with the target to add the necessary refinement through incorporating the equity, accessibility, adequacy, and gender dimensions to be useful at different scales of adaptation for climate change. The Dynamic Adaptation Model (DAM) is a product that has been developed gradually. It can be applied at different scales that can support the different communities and sectorial agencies/departments to guide local and national planning to adaptations while prioritizing in selecting appropriate options in different programs and projects to ensure the efficient use of available resources. DAM is developed based on strong mathematical formulation supported by field evidence. The model is calibrated and validated using field data to quantify the present-day adaptation need and now is being tested for some of the proposed adaptations in the NAP processes to assess its usefulness at the national level. Moreover, it is the home-grown model; therefore, the required customized version for different communities and agencies is possible through updates in the future with its extension for new areal coverage in collaboration with the developers and the alignment of the recent national initiatives. These are the ongoing processes essential to make it worthwhile for the mainstream national adaptation plan that needs further work

Developing socio-ecological scenarios:A participatory process for engaging stakeholders

Deltas are experiencing profound demographic, economic and land use changes and human-induced catchment and climate change. Bangladesh exemplifies these difficulties through multiple climate risks including subsidence/sea-level rise, temperature rise, and changing precipitation patterns, as well as changing management of the Ganges and Brahmaputra catchments. There is a growing population and economy driving numerous more local changes, while dense rural population and poverty remain significant. Identifying appropriate policy and planning responses is extremely difficult in these circumstances. This paper adopts a participatory scenario development process incorporating both socio-economic and biophysical elements across multiple scales and sectors as part of an integrated assessment of ecosystem services and livelihoods in coastal Bangladesh. Rather than simply downscale global perspectives, the analysis was driven by a large and diverse stakeholder group who met with the researchers over four years as the assessment was designed, implemented and applied. There were four main stages: (A) establish meta-framework for the analysis; (B) develop qualitative scenarios of key trends; (C) translate these scenarios into quantitative form for the integrated assessment model analysis; and (D) a review of the model results, which raises new stakeholder insights (e.g., preferred adaptation and policy responses) and questions. Step D can be repeated leading to an iterative learning loop cycle, and the process can potentially be ongoing. The strong and structured process of stakeholder engagement gave strong local ownership of the scenarios and the wider process. This process can be generalised for widespread application across socio-ecological systems following the same four-stage approach. It demands sustained engagement with stakeholders and hence needs to be linked to a long-term research process. However, it facilitates a more credible foundation for planning especially where there are multiple interacting factors

Correlates of healthy life expectancy in low- and lower-middle-income countries

Background: Healthy life expectancy (HALE) at birth is an important indicator of health status and quality of life of a country's population. However, little is known about the determinants of HALE as yet globally or even country-specific level. Thus, we examined the factors that are associated with HALE at birth in low- and lower-middleincome countries. Methods: In accordance with the World Bank (WB) classification seventy-nine low- and lower-middle-income countries were selected for the study. Data on HALE, demographic, socioeconomic, social structural, health, and environmental factors from several reliable sources, such as the World Health Organization, the United Nations Development Program, Population Reference Bureau, WB, Heritage Foundation, Transparency International, Freedom House, and International Center for Prison Studies were obtained as selected countries. Descriptive statistics, correlation analysis, and regression analysis were performed to reach the research objectives. Results: The lowest and highest HALE were observed in Sierra Leone (44.40 years) and in Sri Lanka (67.00 years), respectively. The mean years of schooling, total fertility rate (TFR), physician density, gross national income per capita, health expenditure, economic freedom, carbon dioxide emission rate, freedom of the press, corruption perceptions index, prison population rate, and achieving a level of health-related millennium development goals (MDGs) were revealed as the correlates of HALE. Among all the correlates, the mean years of schooling, TFR, freedom of the press, and achieving a level of health-related MDGs were found to be the most influential factors. Conclusion: To increase the HALE in low- and lower-middle-income countries, we suggest that TFR is to be reduced as well as to increase the mean years of schooling, freedom of the press, and the achievement of a level of health-related MDGs

Afforestation as a Buffer against Storm Surge Flooding Along the Bangladesh Coast

Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchive

The physical sustainability of the coastal zone of the Ganges-Brahmaputra-Meghna delta under climatic and anthropogenic stresses

The Ganges-Brahmaputra-Meghna (GBM) delta is one of the world’s largest deltas, and consists of large areas of low flat lands formed by the deposition of sediment from the GBM rivers. However, recent estimates have projected between 200~1000 mm of climate-driven sea-level rise by the end of the 21st century, at an average rate of ~6 mm/yr. Eustatic sea-level rise is further compounded by subsidence of the delta, which in the coastal fringes varies from 0.2 to 7.5 mm/yr, at an average value of ~2.0 mm/yr. Therefore, the combined effect of sea-level rise and subsidence (termed relative sea-level rise, RSLR) is around 8.0 mm/yr. Such high values of RSLR raise the question of whether sediment deposition on the surface of the delta is sufficient to maintain the delta surface above sea level. Moreover, as the total fluvial sediment influx to the GBM delta system is known to be decreasing, the retained portion of fluvial sediment on the delta surface is also likely decreasing, reducing the potential to offset RSLR. Within this context, the potential of various interventions geared at promoting greater retention of sediment on the delta surface is explored using numerical experiments under different flow-sediment regime and anthropogenic interventions. We find that for the existing, highly managed, conditions, the retained portion of fluvial sediment on the delta surface varies between 22% and 50% during average (when about 20% of the total floodplain in the country is inundated) and extreme (> 60% of the total floodplain in the country is inundated) flood years, respectively. However, the degree to which sediment has the potential to be deposited on the delta surface increases by up to 10% when existing anthropogenic interventions such as polders that act as barriers to delta-plain sedimentation are removed. While dismantling existing interventions is not a politically realistic proposition, more quasi-natural conditions can be reestablished through local- sediment management using tidal river management, cross dams, dredging, bandal-like structures and/or combinations of the above measures

Simulation of freshwater transport network and salt flux in the Bangladesh delta

Circulation of saline water is important for maintaining water quality in the Ganges-Brahmaputra-Meghna (GBM) delta because of its vulnerability to the threat of climate change. We applied a numerical model to examine the volume and salt transports within the GBM delta, Bangladesh. To understand the components of salt water intrusion driven by tidal and subtidal (residual) transports, we selected 19 cross-sections to represent the complex delta circulation in a simplified network model. Our results show that over 82.51% of GBM river water drains through the eastern estuarine system (EES) in the wet season, increasing to 98.37% in the dry season. Residual transport can be comparable in size with the tidal transport in the wet season, and one order of magnitude smaller in the dry season. The western estuarine system (WES) experiences serious salinity intrusion in the dry season, and strong seasonal variability in both tidal and subtidal transport, with suppression of tide-driven transport observed during the wet season. Our results show the sub-channels area of the Lower Meghna River also faces the risk from salinity intrusion issues, as stronger tidal salt flux is estimated in the dry season. Tidal volume transport varies seasonally, corresponding to the variability of river discharge. A simplified solution by means of polynomial expansion was applied to describe the tidal propagation within river channels. Inland penetration of tidal energy is reduced with large river discharge, and additionally the propagation speed of the tidal wave increases in the wet season. Our analysis helps understand the response of the three estuarine systems to seasonal and tidal controls, and can be used to inform river management about the upstream-downstream linkages