A Comprehensive Model of Human Neuromuscular Function During Repeated Isometric Contractions: Predicting the Effect of Age on Fatigue

Repeated or prolonged activation of skeletal muscle results in an acute decline in the muscle\u27s ability to produce force, which is typically referred to as fatigue. Muscle fatigue is likely related to the by-products of cellular metabolism, alterations in neural activation and diminished membrane excitability that have been shown to accompany repeated contractions. However, the complicated etiology of the fatigue process makes it difficult to understand the relative influence of these physiological responses. Computational modeling of the skeletal muscle response to repeated activation is an appealing means of gaining insight into the mechanisms of muscle fatigue. A reasonably comprehensive model would include components that represent motor neurons and populations of muscle fibers that reflect the range of metabolic and contractile characteristics known to exist in human skeletal muscle. Consideration of joint and connective tissue mechanical properties will add translational value by predicting whole joint segment behavior that can be validated by in vivo experimentation. The proposed dissertation project involved the development of a computational model incorporating multiple components meant to represent the function of the intact neuromuscular system. The complete model combines previously-validated models of neural activation and contractile behavior with a control function that attempts to match torque output to a pre-determined task. The model uses experimentally-derived functions describing metabolic cost and force inhibition to predict the loss of force generating capacity during repeated activation. Once tested using data from a group of adult men, the parameters of this model were altered to reflect age-related changes in the human neuromuscular system. The model\u27s ability to predict the well-established phenomenon of age-related fatigue resistance during isometric contractions was then tested. The results from this series of studies support the utility of a computational approach to the investigation of muscle fatigue, and provide useful tools for future studies

Managing Large Task Public-Private Partnerships

Memo Overview Panel Recommendations on improving public and private relationships: There have been numerous reports from GAO and other organizations that all levels of Governments, even assuming normal economic growth, will experience fiscal shortfalls stretching far into the future. There are also numerous reports concluding that unless we undertake major investment programs in our collective goods issues of education, infrastructure, energy and health that we will not be able to accelerate growth and alter this future. Our panel is developing strategies and recommendations, both short and long term, on putting the organizations-public, private and non-profit together differently, with new “rules of the game,” so that synergy, efficiencies, partnerships and innovation will enable us to forge approaches that can help address these dilemmas. In our panel’s deliberations we have observed that this approach is not new and that there have been abundant examples of such initiatives in our history. The panel noted that we should learn the good and bad lessons from this rich history. Short term: The recent IBM Center for the Business of Government report on the lessons from the Recovery had a number of recommendations that could alter the way that Government operates that could substantially improve the way governments at all levels interact with other sectors. By setting outcome goals, focusing on team implementation approaches, assigning and assessing risks, improving contracting and procurement, and horizontal team building all highlighted what could be done to significantly improve the effectiveness of how we work across sectors. The lessons of hurricane Katrina, and the NAPA panel on the improvements in the budgeting and implementation process of the Corp’s of Engineers, along with the lessons of the recent Gulf oil spill all show the power of partnerships in problem solving. Recommendations are being developed from these lessons that could be implemented by the next administration. Long term: The panel is looking at experiments in new governance structures in the country, which if expanded could alter the nature of the relationship among the sectors. The panel defined the operating principles upon which a new relationship among the sectors could be built: starting point is outcomes and results; align funding with planning up front; look at all costs over time; use business plans with identified funding streams that relies on beneficial use funding streams linked to mission and results; look at alternative systems; move from risk avoidance to risk identification, risk mitigation, and risk management. The panel also concluded that many of the recent experiments had generated important learning lessons particularly relating to transparency and accountability. The Presidio Trust Act established by Congress to reduce the largest item in the Park Service Budget, and the subsequent NAPA panel on the Trust, provides a good example of a “public benefit corporation” – a non-profit organization that embodies the panel’s operating principles and addresses the concerns identified. Given these principles and examples, the panel is developing recommendations that would be helpful to the next administration in the development and operations of: infrastructure, security and safety for our ports of entry, park services, etc. Conclusion: These short and long term recommendations would enable experimentation in doing things differently and putting ourselves and our organizations together differently so that the major asset in America, innovation in the way we organize ourselves to solve problems, can be used to deal with our difficult fiscal future and our need in the same time to make significant investments

Developing Effective Mechanisms that Promote Fiscal Sustainability

State and local governments will likely continue to face the stress and shortfalls caused by the Great Recession for an extended period. Three years of research on fiscal sustainability in local government in Southern California identifies strategies that can be used to address this stress, including options for the executive, budget, and finance functions of these jurisdictions

Aligning Fiscal and Environmental Sustainability

The future of environmental sustainability will be driven by the capacity of local, state and federal levels of government to develop fiscal sustainability. For example, in the case of the Alameda Corridor in Los Angeles County environmental sustainability advanced only because of the fiscal sustainability of the project. The environmental improvements of reducing particulate car and truck pollutants, as well as remediation of underground water pollution, were financed by the innovative public–private partnership that generated revenues to pay for long-neglected environmental degradations (Callahan 2007). The Alameda Corridor rail construction case illustrates a small but emerging set of cases showing local government leaders linking fiscal de cisions to environmental issues (Wang et al. 2013), as well as the connection of public administration and environmental sustainability (Fiorino 2010). In research on leadership adaptation to fiscal stress, a recent set of case studies offered practical lessons for connecting fiscal and environmental sustainability (Pisano and Callahan 2012; 2013). These practices include: framing fiscal stress as a catalyst for addressing long-term natural resource needs, done recently in San Bernardino County; developing fiscal expertise before a crisis, in Los Angeles County; and more inclusive budget processes to develop trust, as found in the Whittier School District (Rubio-Cortes 2012). The findings from these and other cases offer actionable lessons for leaders in the public sector and communities to link environmental and fiscal sustainability. This chapter describes examples of fiscal sustainability that can fund environmental sustainability

Bankruptcy: The Divergent Cases of the City and the County of San Bernardino

The cases are the two separate jurisdictions of the City of San Bernardino and the County of San Bernardino, California, U.S.A. The matched pair offers a unique opportunity for a research design that compares a bankrupt city government with a jurisdiction sharing the essential demographic, economic, and geographical features, though as a county a different level of government. The two cases offer insights into bankruptcy as not simply a function of economic forces or recent poor policy choices but as a result of a pattern of decision-making, a structure of government, and the constraints placed on leadership by structure and electoral politics. The analysis of this comparison allows us to unbundle leadership and show that differences in strategy, transparency, civic culture, trust and accountability explain the divergent outcomes

Zero-gravity Mean Free Surface Curvature of a Confined Liquid in a Radially-Vaned Container

A variety of increasingly intricate container geometries are under consideration for the passive manipulation of liquids aboard spacecraft where the impact of gravity may be neglected. In this study we examine the mean curvature of a liquid volume confined within a radial array of disconnected vanes of infinite extent. This particular geometry possesses a number of desirable characteristics relevant to waste water treatment aboard spacecraft for life support. It is observed that under certain conditions the slender shape of the free surface approaches an asymptote, which can be predicted analytically using new hybrid boundary conditions proposed herein. This contribution represents possibly the final extension of what has been referred to as the method of de Lazzer et al. (1996). The method enables the integration of the Young-Laplace equation over a domain with its boundaries, including the wetted portion of the solid boundaries, symmetry planes, and circular arcs representing free surfaces at the center plane of the liquid body. Asymptotic solutions at several limits are obtained and the analysis is confirmed with numerical computations

Using Common-Pool Resource Principles to Design Local Government Fiscal Sustainability

This article analyzes local government fiscal sustainability as a common-pool resource (CPR) problem. By comparing the experiences of Los Angeles County, San Bernardino City, and San Bernardino County, the analysis applies a framework developed from three decades of CPR research to show the importance of six micro-situational variables — communications with the full set of participants, known reputations of participants, high marginal per capita return, entry or exit capabilities, longer time horizon, and agreed-upon sanctioning capabilities — in shaping collective-action dynamics and building the trust and reciprocity among stakeholders needed for achieving fiscal sustainability. The underlying contextual conditions for these micro-situational variables vary based on specific socio-economic and political settings, but the findings suggest that institutions and processes can be designed based on several well-tested principles in CPR governance to encourage stakeholders to look beyond their immediate self-interests and to make decisions that account for the community’s long-term fiscal sustainability

National Elm Trial

Although many Dutch elm disease-resistant elm cultivars are available in the nursery trade, much of the public is hesitant to purchase and plant any elm tree. In order to promote interest in planting these trees, scientific data on growth, form, and pest resistance for existing Dutch elm disease resistant elm cultivars are essential

A 3-D display head-set for personalized computing

Thesis (M.S.V.S.)--Massachusetts Institute of Technology, Dept. of Architecture, 1983.MICROFICHE COPY AVAILABLE IN ARCHIVES AND ROTCHIncludes bibliographical references (leaves 106-109).This thesis covers the design and implementation of a binocular display head-set akin to Dr . Ivan E. Sutherland's head-mounted display, but using several new technologies and new techniques in computer graphics: small portable video display, transmitter and receiver; write-once optical video disc recorder; a magnetic position sensor, and a depth cue based animation package. This implementation has permitted the creation of a highly interactive three dimensional trainer/simulator . Computer generated controlled images are optically mixed into the surrounding environment by imaging through two beamsplitter mirrors positioned in front of the viewer's eyes. The source of the images on the display head-set is two Sony Flat CRT's mounted on top of the head-set pointing downward. The beamsplitter mirrors are angled out from the bottom of a pair of eyeglasses. Normal vision is through the eyeglasses; the TV images are reflected in the mirrors . The viewer is able to manipulate the display image by "touching" and "moving" the image with his hand, or even to "look around" the display image. A position sensor located on either the viewers hand or the head-set itself provides the - input for the manipulation. Stereo for 3-D viewing is obtained by transmitting two video sources to the two receivers on two OHF channels located in a small beltpack. This thesis also describes a write-once optical video disc recorder that is used to store "pre-computed" view-point dependent images. The images of a scene were recorded in coherent segments to create a visual data base; included were full rotations and general movements of stereoscopic image pairs. Real-time manipulation of the pre-recorded images is done though fast-executing commands on the optical write-once recorder. The graphics package permits quick construction and scripting of objects. To increase the sensation of 3-D, special attention is paid to the inclusion and the highlighting of physiological and psychological depth cues.by Mark A. Callahan.M.S.V.S