PhD

dissertationPrimary cultures containing 99% neurons, 99% non-neuronal cell (glia), or both cell types prepared from the sympathetic ganglia of 12-day chick embryos. Levels of cyclic AMP in the non-neuronal cells (~ 14 pmoles per mg protein) were approximately three-fold higher than levels in the neurons (~ 4 pmoles per mg protein). Mixed cultures had concentrations of cyclic AMP which fell between the values measured for pure neuronal and pure non-neuronal cultures. The measured cyclic AMP values of mixed cultures were indistinguishable from values predicted by summing the expected contributions of the neurons and non-neuronal cells. Thus, contact between the neurons and non-neuronal cells in these mixed cultures did not appear to alter the level of cyclic AMP in either cell type. Neuronal-glial interactions, such as the specific neuronal stimulation of non-neuronal cell proliferation, occurred independently of any changes in the level of cyclic AMP in the mixed cultures. Cell density was varied in both pure and mixed cultures, and both cyclic AMP concentrations and amounts of 3H-thymidine incorporation into DNA were measured. The cyclic AMP content of the non-neuronal cells varied inversely with cell density. 3H-Thymidine incorporation was independed of cell density in both neuronal and non-neuronal cultures. Parallel density-dependent decreases in cyclic AMP concentration and 3H-thymidine incorporation were observed in mixed cultures as cell density was increased. The data suggest that there is no relationship between changes in rate of non-neuronal cell proliferation and cyclic AMP levels in these cultures. The effects of some putative neurotransmitters, analogs of transmitters, and adenosine on levels of cyclic AMP were determined in primary neuronal, non-neural, and mixed cultures of embryonic chick sympathetic ganglion cells. Adenosine increased the level of cyclic AMP in the non-neuronal cells but had no effect on levels in either neuronal or mixed cultures. Norepinephrine increased the level of cyclic AMP in neurons, had no effect on the non-neuronal levels, and decreased the cyclic nucleotide content of mixed cultures. Dopamine, isoproterenol, and pilocarpine all caused a reduction in the cyclic AMP content of mixed cultures but had no effect on levels of either neurons on non-neuronal cells. The measured cyclic AMP levels of norepinephrine- and isoproterenol-treated mixed cultures were significantly lower than the values predicted by summing the expected individual contributions of the neurons and the non-neuronal cells. Thus, cells in mixed cultures sometimes responded differently from cells in pure cultures

Dreams, Hopes, Realities: NASA's Goddard Space Flight Center, the First Forty Years

Throughout history, the great achievements of civilizations and cultures have been recorded in lists of dates and events. But to look only at the machinery, discoveries, or milestones is to miss the value of these achievements. Each goal achieved or discovery or made represents a supreme effort on the part of individual people who came and worked together for a purpose greater than themselves. Driven by an innate curiosity of the spirit, we have built civilizations and discovered new worlds, always reaching out beyond what we knew or thought was possible. These efforts may have used ships or machinery, but the achievement was that of the humans who made those machines possible- remarkable people willing to endure discomfort, frustration, fatigue, and the risk of failure in the hope of finding out something new. This is the case with the history of the Goddard Space Flight Center. This publication traces the legacy of successes, risks, disappointments and internationally recognized triumphs of the Center's first 40 years. It is a story of technological achievement and scientific discovery; of reaching back to the dawn of time and opening up a new set of eyes on our own planet Earth. In the end, it is not a story about machinery or discoveries, but a story about ourselves. If we were able to step off our planet, and if we continue to discover new mysteries and better technology, it is because the people who work at Goddard always had a passion for exploration and the dedication to make it happen. The text that follows is a testimony to the challenges people at the Goddard Space Flight Center have faced and overcome over almost half a century. Today, we stand on the threshold of a new and equally challenging era. It will once again test our ingenuity, skills, and flexibility as we find new ways of working with our colleagues in industry, government, and academia. Doing more with less is every bit as ambitious as designing the first science instrument to study the heavens. But if we are to continue exploring our world and our universe, it is every bit as important. Robert H. Goddard once said, "The dream of yesterday is the hope of today and the reality of tomorrow." This is our heritage. Our challenge is to keep our spirit of dedication, vision, and innovative thinking alive, so we can turn today's dreams into a new century of possibility and progress. Our journeys into space are the greatest ongoing adventure the human race has ever undertaken, and everyone here has played an important role in that endeavor. This book is about everyone who has worked at the Goddard Space Flight Center

1861 - Solution of the Negro Question

Source citation: Gen. Lane and his Solution of the Negro Question, New York (NY) World, November 19, 1861, p. 1.https://scholarworks.uni.edu/nhomefront/1010/thumbnail.jp

NET ZERO ENERGY BUILDING ANALYSIS FOR MCDONALDS USA, LLC

As a leader in the global quick service restaurant market, McDonald’s USA, LLC aims to push the limits of their energy efficiency and tasked the Duke team with exploring the possibility of a ‘net zero energy’ restaurant. This exploration includes researching and proposing design aspects and technologies for a restaurant in the Chicago, IL area to achieve net zero energy (NZE) consumption onsite utilizing the LEED Volume Prototype restaurant as a baseline comparison. The project focused on improving current technologies and building design aspects including, but not limited to, the following areas: the building envelope, including roof and wall insulation and window design; the service hot water system (SHW); lighting fixtures and systems; and ventilation system. Due to the heavy influence of McDonald’s operational design on its brand, the recommendations included in the analysis account for the restaurant’s operational constraints. The final deliverable presents maximum energy savings possible without violating most of these constraints and estimates the amount of renewable energy necessary to meet the resulting decreased energy demand of the proposed ‘Net Zero Restaurant’ to meet the goal of a net zero energy site

Letters from Chas. Eldered Shelton, John L. Tilton, George Clammer, and Wallace R. Lane

Letters concerning A. G. Reid, an applicant for position in athletic department at Utah Agricultural College

Can we trust “Magnitude-based inference”?

Editoria