1,438 research outputs found
Achieving a New Standard in Primary Care for Low-Income Populations -- Case Studies of Redesign and Change Through a Learning Collaborative
Describes four case studies that focus on improving patient care delivery systems through learning collaboratives that were undertaken by New York City's nonprofit Primary Care Development Corporation
Object Manipulation using a Multirobot Cluster with Force Sensing
This research explored object manipulation using multiple robots by developing a control system utilizing force sensing. Multirobot solutions provide advantages of redundancy, greater coverage, fault-tolerance, distributed sensing and actuation, and reconfigurability. In object manipulation, a variety of solutions have been explored with different robot types and numbers, control strategies, sensors, etc. This research involved the integration of force sensing with a centralized position control method of two robots (cluster control) and building it into an object level controller. This controller commands the robots to push the object based on the measured interaction forces between them while maintaining proper formation with respect to each other and the object.
To test this controller, force sensor plates were attached to the front of the Pioneer 3-AT robots. The object is a long, thin, rectangular prism made of cardboard, filled with paper for weight. An Ultra Wideband system was used to track the positions and headings of the robots and object. Force sensing was integrated into the position cluster controller by decoupling robot commands, derived from position and force control loops.
The result was a successful pair of experiments demonstrating controlled transportation of the object, validating the control architecture. The robots pushed the object to follow linear and circular trajectories. This research is an initial step toward a hybrid force/position control architecture with cluster control for object transportation by a multirobot system
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Total syntheses of the regenerative natural products vinaxanthone, xanthofulvin, and eupalinilide E.
textThe fungal metabolites vinaxanthone and xanthofulvin possess the remarkable ability to restore motor function in animal models of complete spinal cord transection making them the most promising small molecules for the development of spinal cord injury (SCI) therapeutics. A concise nine-step total synthesis of vinaxanthone was accomplished utilizing a biomimetic dimerization of the putative precursor 5,6-dehydropolivione and the first reported synthesis of xanthofulvin was achieved in 15-steps highlighted by an unprecedented enaminone O-to-C carboxyl transfer to forge key carbon-carbon bonds. Both natural products were also identified as positive allosteric modulators of the G-protein coupled receptor (GPCR), GPR91, thus elucidating their modes of action accounting for their regenerative capabilities. Furthermore, a unique ynone coupling reaction was developed in order to access various vinaxanthone analogs for structure activity relationship (SAR) studies. This resulted in the preparation of a small molecule library of 25 vinaxanthone analogs that demonstrated pronounced neuronal regeneration within laser axotomy assays performed in vivo on C. elegans.
The plant derived natural product eupalinilide E has been found to promote the ex vivo expansion of hematopoietic stem and progenitor cells (HSPCs) which have the potential to improve the success of medical procedures such as bone marrow transplants. In light of its promising applications, unknown mechanism of action, and scarcity in nature the total synthesis of eupalinilide E was undertaken. Efforts culminated in the first enantioselective total synthesis of the natural product in 20-steps, which showcases a Favorskii rearrangement, borylative enyne cyclization, aldehyde-ene ring closure, and a dual allylic oxidation.Chemistr
Enacting Politics through Art: Encounters between Queer and Trans of Color Organizers and the Canadian City.
This ethnographic study investigates the role of the arts in the relationship between urban governmental institutions and queer and transgender people of color (QTPOC) community organizations. Toronto is a fitting site for this project given that the city is intensively mobilizing the arts to foster urban economic development and that it is uniquely emblematic of Canada’s regulatory embrace of racialized, gendered and sexual minorities. The findings from this study are derived from two years of ethnographic fieldwork and 63 semi-structured interviews carried out between 2012 and 2014 among state arts institutions, funding bodies and community arts initiatives. Drawing from the fields of social work, anthropology, queer studies, and critical ethnic studies, I argue that the arts operate as a means of constructing the neoliberal welfare state through the incorporation of QTPOC. These inclusionary creative citizenship practices enable QTPOC to engage in a feelings-based mode of community development in ways that are nevertheless constrained by how state institutions administer the programs that fund these initiatives. Each chapter of this dissertation is organized around an ethnographic dilemma that brings into focus how the arts surface as the solution to the diverse challenges that government institutions and minority community organizations face. As a uniquely elastic mode of social action, the arts serve as the linchpin between QTPOC efforts to counter the intertwined mechanisms of racism, sexism, transphobia and homophobia, and municipal imperatives to promote economic growth and address the social exclusion of marginalized populations. By using the arts to explore the interrelated workings of urban government and grassroots collectives, this study demonstrates how questions of space, time, feelings, humanity and political economy are deeply implicated in the politics of making racialized, gendered and sexual difference.PhDSocial Work and AnthropologyUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/120709/1/chinm_1.pd
Ethanol Ablation of a Peripheral Nerve Sheath Tumor Presenting as a Small Bowel Obstruction.
Ethanol has historically been used as an ablative agent for a variety of lesions. One of the more common applications of this technique is celiac plexus neurolysis; however, recent reports have suggested a role for the endoscopic alcohol ablation of a variety of solid and cystic lesions. We report a novel case of endoscopic ethanol ablation of a peripheral nerve sheath tumor presenting as a small bowel obstruction
A Proposed Model and Measurement Instrument for the Formation of IS Satisfaction: The Case of End-User Computing Satisfaction
This paper presents a model that explicitly defines satisfaction and the antecedent factors that help form it. The model distinguishes between the notions of expectations and desires and argues that both have an impact on overall satisfaction in the form of the difference between priors and post hoc usage perceptions coupled with the individual’ s evaluation of these discrepancies. These two types of satisfaction, in turn, will have both direct and multiplicative impact on overall satisfaction. Given this understanding, we highlight possiblelimitations in existing instruments and provide a solution for creating new measures that should overcome these limitations. A complete set of measures is provided in this paper for future empirical testing, which are general enough to allow researchers to create measures for other aspects related to IS satisfaction beyond those targeted in this paper. We employ our model within the context of the five satisfaction areas outlined by Doll and Torzadeh (1988). Building upon their initial set of perceptual measures, we examine whether there are indeed two types of discrepancy effects, whether there are multiplicative effects for each discrepancy, and whether there is a higher order interaction between the two discrepancy components. Partial least squares analyses of data consisting of over 200 instructional staff member at a large university related to their satisfaction with an online grading system are employed and the results presented at the conference
Pilots’ visual scan pattern and attention distribution during the pursuit of a dynamic target
Introduction: The current research is investigating pilots’ visual
scan patterns in order to assess attention distribution during
air-to-air manoeuvers. Method: A total of thirty qualified
mission-ready fighter pilots participated in this research. Eye
movement data were collected by a portable head-mounted eye-tracking
device, combined with a jet fighter simulator. To complete the task,
pilots have to search for, pursue, and lock-on a moving target whilst
performing air-to-air tasks. Results: There were significant
differences in pilots’ saccade duration (msec) in three operating
phases including searching (M=241, SD=332), pursuing (M=311, SD=392),
and lock-on (M=191, SD=226). Also, there were significant differences
in pilots’ pupil sizes (pixel2) of which lock-on phase was the largest
(M=27237, SD=6457), followed by pursuing (M=26232, SD=6070), then
searching (M=25858, SD=6137). Furthermore, there were significant
differences between expert and novice pilots on the percentage of
fixation on the HUD, time spent looking outside the cockpit, and the
performance of situational awareness (SA). Discussion: Experienced
pilots have better SA performance and paid more attention to the HUD
but focused less outside the cockpit when compared with novice pilots.
Furthermore, pilots with better SA performance exhibited a smaller
pupil size during the operational phase of lock-on whilst pursuing
a dynamic target. Understanding pilots’ visual scan patterns and
attention distribution are beneficial to the design of interface
displays in the cockpit and in developing human factors training
syllabi to improve safety of flight operations
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