568 research outputs found

    The Limited Partnership in New York, 1822-1853: Partnerships without Kinship

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    In 1822, New York became the first common-law state to authorize the formation of limited partnerships, and over the ensuing decades, many other states followed. Most prior research has suggested that these statutes were utilized only rarely, but little is known about their effects. Using newly collected data, this paper analyzes the use of the limited partnership in nineteenth-century New York City. We find that the limited partnership form was adopted by a surprising number of firms, and that limited partnerships had more capital, failed at lower rates, and were less likely to be formed on the basis of kinship ties, compared to ordinary partnerships. The latter differences were not simply due to selection: even though the merchants who invested in limited partnerships were a wealthy and successful elite, their own ordinary partnerships were quite different from their limited partnerships. The results suggest that the limited partnership facilitated investments outside kinship networks, and into the hands of talented young merchants.

    Cellular Optogenetics for Spatiotemporal Control of Kinase Signaling and Biological Trojan Horses for Light-mediated Drug Release

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    Light provides an instantaneous, orthogonal, and spatially targeted tool to control cellular biochemistry and perform photochemistry. In the first three chapters of my thesis, I will discuss light as a tool for controlling intracellular communication. Intracellular signaling via kinases is highly controlled in space and time. While many tools exist that allow us to modulate signaling events on a global scale or observe signaling events with high spatial and temporal resolution, there are relatively few tools that are amenable to studying subcellular compartmentalized signaling. To this end, I have developed two optogenetic proteins for investigating the localized functions of 1) protein kinase A and 2) its second messenger cAMP. The optogenetic protein kinase A takes advantage of the Cry2-Cib photodimerizing pair. In short, a protein kinase A catalytic subunit with low constitutive activity was fused to Cry2 such that, upon stimulation with light, it translocates to whatever subcellular region Cib is localized to and activity is restored. In order to investigate localized cAMP signaling, a photoactivated adenylate cyclase was engineered to be expressed at specific subcellular locations. Upon activation with light, large increases in cellular cAMP levels are observed resulting in down-stream signaling events. I am still tweaking the photoactivated adenylate cyclase to control local cAMP signaling. The second half of my thesis discusses efforts to develop cell mediated delivery of phototherapeutics. Chapter 5 discusses the use of erythrocyte membranes as protective pools and launching pads for peptide therapeutics. Chapter 6 focuses on efforts to develop a treatment strategy for glioblastoma multiforme by loading tumor-homing neural stem cells with cobalamin-drug conjugates.Doctor of Philosoph

    Relationships between performance, muscle amino acid content, and muscle fiber characteristics in yearling bulls

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    Call number: LD2668 .T4 1979 O23Master of Scienc

    The role of interleukin-1 in neuroinflammation and Alzheimer disease: an evolving perspective

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    Elevation of the proinflammatory cytokine Interleukin-1 (IL-1) is an integral part of the local tissue reaction to central nervous system (CNS) insult. The discovery of increased IL-1 levels in patients following acute injury and in chronic neurodegenerative disease laid the foundation for two decades of research that has provided important details regarding IL-1's biology and function in the CNS. IL-1 elevation is now recognized as a critical component of the brain's patterned response to insults, termed neuroinflammation, and of leukocyte recruitment to the CNS. These processes are believed to underlie IL-1's function in the setting of acute brain injury, where it has been ascribed potential roles in repair as well as in exacerbation of damage. Explorations of IL-1's role in chronic neurodegenerative disease have mainly focused on Alzheimer disease (AD), where indirect evidence has implicated it in disease pathogenesis. However, recent observations in animal models challenge earlier assumptions that IL-1 elevation and resulting neuroinflammatory processes play a purely detrimental role in AD, and prompt a need for new characterizations of IL-1 function. Potentially adaptive functions of IL-1 elevation in AD warrant further mechanistic studies, and provide evidence that enhancement of these effects may help to alleviate the pathologic burden of disease

    Unmanned Aircraft System Assessments of Landslide Safety for Transportation Corridors

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    An assessment of unmanned aircraft systems (UAS) concluded that current, off-the-shelf UAS aircraft and cameras can be effective for creating the digital surface models used to evaluate rock-slope stability and landslide risk along transportation corridors. The imagery collected with UAS can be processed using a photogrammetry technique called Structure-from-Motion (SfM) which generates a point cloud and surface model, similar to terrestrial laser scanning (TLS). We treated the TLS data as our control, or “truth,” because it is a mature and well-proven technology. The comparisons of the TLS surfaces and the SFM surfaces were impressive – if not comparable is many cases. Thus, the SfM surface models would be suitable for deriving slope morphology to generate rockfall activity indices (RAI) for landslide assessment provided the slopes. This research also revealed that UAS are a safer alternative to the deployment and operation of TLS operating on a road shoulder because UAS can be launched and recovered from a remote location and capable of imaging without flying directly over the road. However both the UAS and TLS approaches still require traditional survey control and photo targets to accurately geo-reference their respective DSM.List of Figures ...................................................................................................... vi List of Abbreviations ......................................................................................... vii Acknowledgments ................................................................................................ x Executive Summary ............................................................................................. xi CHAPTER 1 INTRODUCTION .......................................................................... 1 CHAPTER 2 LITERATURE REVIEW ................................................................ 4 2.1 Landslide Hazards .................................................................................... 4 2.2 Unmanned Aircraft Systems Remote Sensing.......................................... 6 2.3 Structure From Motion (SfM) .................................................................. 7 2.4 Lidar terrain mapping ............................................................................... 8 CHAPTER 3 STUDY SITE/DATA .................................................................. 11 CHAPTER 4 METHODS ................................................................................ 13 4.1 Data Collection ............................................................................................. 13 4.1.1 Survey Control ..................................................................................... 14 4.1.2 TLS Surveys ........................................................................................ 16 4.1.3 UAS Imagery ....................................................................................... 17 4.1.4 Terrestrial Imagery Acquisition ........................................................... 19 4.2 Data Processing ............................................................................................ 20 4.2.1 Survey Control ..................................................................................... 20 4.2.2 TLS Processing .................................................................................... 20 4.2.3 SfM Processing .................................................................................... 21 4.2.4 Surface Generation .............................................................................. 22 4.3 Quality Evaluation ........................................................................................ 23 4.3.1 Completeness ....................................................................................... 23 4.3.2 Data Density/Resolution ...................................................................... 23 4.3.3 Accuracy Assessment .......................................................................... 23 4.3.2 Surface Morphology Analysis ............................................................. 24 4.2.6 Data Visualization ............................................................................... 25 CHAPTER 5 RESULTS ................................................................................. 27 v 5.1 UTIC DSM evaluation.................................................................................. 27 5.1.1 Completeness evaluation ..................................................................... 28 5.1.2 Data Density Evaluation ...................................................................... 29 5.1.3 Accuracy Evaluation............................................................................ 30 5.2 Geomorphological Evaluation ...................................................................... 32 CHAPTER 6 DISCUSSION ............................................................................ 35 6.1 Evaluation of UAS efficiencies .................................................................... 35 6.2 DSM quality and completeness .................................................................... 37 6.3 Safety and operational considerations .......................................................... 37 CHAPTER 7 CONCLUSIONS AND RECOMMENDATIONS ................................ 40 7.1 Technology Transfer..................................................................................... 41 7.1.1 Publications ......................................................................................... 41 7.1.2 Presentations ........................................................................................ 42 7.1.3 Multi-media outreach .......................................................................... 43 6.4 Integration of UAS and TLS data ................................................................. 44 REFERENCES .............................................................................................. 4

    Massively Scalable Inverse Reinforcement Learning in Google Maps

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    Optimizing for humans' latent preferences is a grand challenge in route recommendation, where globally-scalable solutions remain an open problem. Although past work created increasingly general solutions for the application of inverse reinforcement learning (IRL), these have not been successfully scaled to world-sized MDPs, large datasets, and highly parameterized models; respectively hundreds of millions of states, trajectories, and parameters. In this work, we surpass previous limitations through a series of advancements focused on graph compression, parallelization, and problem initialization based on dominant eigenvectors. We introduce Receding Horizon Inverse Planning (RHIP), which generalizes existing work and enables control of key performance trade-offs via its planning horizon. Our policy achieves a 16-24% improvement in global route quality, and, to our knowledge, represents the largest instance of IRL in a real-world setting to date. Our results show critical benefits to more sustainable modes of transportation (e.g. two-wheelers), where factors beyond journey time (e.g. route safety) play a substantial role. We conclude with ablations of key components, negative results on state-of-the-art eigenvalue solvers, and identify future opportunities to improve scalability via IRL-specific batching strategies
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