What Is Grounded Theory Good For?

Grounded theory (GT) made its appearance in the social sciences in 1967 with publication of Barney Glaser and Anselm Strauss’s The Discovery of Grounded Theory. Glaser and Strauss advocated for systematically discovering and interpreting empirical data to generate theory, in contrast to testing or verifying theory derived from a priori assumptions. In the intervening 50 years, GT has spread into a wide range of fields including journalism and mass communication. Variations of the method have been developed, and debate has ensued about its relation to positivism and constructivism as well as pragmatism and postmodernism and about its value for critical race theory, feminist theory, and indigenous and other critical methods and theories. When and how is it best used? Is it misunderstood or misused by some? Is it more than a method? We asked senior scholars with expertise in GT to reflect on these issues, beginning with Vivian Martin, coeditor with Astrid Gynnild of Grounded Theory: The Philosophy, Method, and Work of Barney Glaserpublished by BrownWalker Press (2012). Martin, professor and chair of the Department of Journalism at Central Connecticut State University, argues the method has been misunderstood even by those who use it, often conflated with qualitative studies, with only two GT studies published in journalism and mass communication. It is practical and subversive, she observes, with the ability to develop new concepts and link ideas across disciplines. She advocates a closer adherence to Glaser’s original intentions for the method. Responding to Martin is Clifton Scott, associate professor in the Department of Communication Studies at the University of North Carolina at Charlotte. Scott is the author of “Grounded Theory” in Encyclopedia of Communication Theory, edited by Steven Littlejohn and Sonja Foss published by SAGE (2009). While agreeing with Martin that the name often is misapplied, Scott argues for less preoccupation with policing the purity of the method in favor of developing multiple approaches appropriate to it as a methodology. Reacting to both Martin and Scott, Bonnie Brennen critiques the original GT approach as neglecting “methodological self-consciousness,” which would uncover researchers “theoretical assumptions, power relations, class positions and personal experiences.” Brennen, the Nieman Professor of Journalism in the Diederich College of Communication at Marquette University, is the author of Qualitative Research Methods for Media Studies, second edition, published by Routledge in 2017. Finally, Meenakshi Gigi Durham, responding to all three, expresses optimism about GT’s potential to spur new inquiry through exploration of social life, while she proposes that, like all theory, it be seen as necessarily dynamic and evolutionary. Durham is a professor in the School of Journalism and Mass Communication at the University of Iowa and associate dean of the College of Liberal Arts and Sciences. She is the editor with Douglas M. Kellner of Media and Cultural Studies: Keyworks, second edition, published by Blackwell (2011). Lana Rakow, Associate Editor Louisa Ha, Edito

Lifelong Multi-Agent Path Finding in Large-Scale Warehouses

Multi-Agent Path Finding (MAPF) is the problem of moving a team of agents to their goal locations without collisions. In this paper, we study the lifelong variant of MAPF, where agents are constantly engaged with new goal locations, such as in large-scale automated warehouses. We propose a new framework Rolling-Horizon Collision Resolution (RHCR) for solving lifelong MAPF by decomposing the problem into a sequence of Windowed MAPF instances, where a Windowed MAPF solver resolves collisions among the paths of the agents only within a bounded time horizon and ignores collisions beyond it. RHCR is particularly well suited to generating pliable plans that adapt to continually arriving new goal locations. We empirically evaluate RHCR with a variety of MAPF solvers and show that it can produce high-quality solutions for up to 1,000 agents (= 38.9\% of the empty cells on the map) for simulated warehouse instances, significantly outperforming existing work.Comment: Published at AAAI 202

Small Aircraft Transportation System Concept and Technologies

This paper summarizes both the vision and the early public-private collaborative research for the Small Aircraft Transportation System (SATS). The paper outlines an operational definition of SATS, describes how SATS conceptually differs from current air transportation capabilities, introduces four SATS operating capabilities, and explains the relation between the SATS operating capabilities and the potential for expanded air mobility. The SATS technology roadmap encompasses on-demand, widely distributed, point-to-point air mobility, through hired-pilot modes in the nearer-term, and through self-operated user modes in the farther-term. The nearer-term concept is based on aircraft and airspace technologies being developed to make the use of smaller, more widely distributed community reliever and general aviation airports and their runways more useful in more weather conditions, in commercial hired-pilot service modes. The farther-term vision is based on technical concepts that could be developed to simplify or automate many of the operational functions in the aircraft and the airspace for meeting future public transportation needs, in personally operated modes. NASA technology strategies form a roadmap between the nearer-term concept and the farther-term vision. This paper outlines a roadmap for scalable, on-demand, distributed air mobility technologies for vehicle and airspace systems. The audiences for the paper include General Aviation manufacturers, small aircraft transportation service providers, the flight training industry, airport and transportation authorities at the Federal, state and local levels, and organizations involved in planning for future National Airspace System advancements

Physical Properties of Trans-Neptunian Object (20000) Varuna

We present new time-resolved photometric observations of the bright trans-Neptunian object (20000) Varuna and use them to study the rotation period, shape, and color. In observations from 2001 February and April, we find a best-fit two-peaked lightcurve with period 6.3442 +-0.0002 hr. The peak-to-peak photometric range in the R-band is 0.42 +-0.02 mag. We find no rotational variation in colors over the 0.45 < lambda < 0.85 micron wavelength range. From the short double-peaked period and large amplitude we suggest that Varuna is an elongated, prolate body perhaps close in shape to one of the Jacobi ellipsoids. If so, the ratio of the axes projected into the plane of the sky is 1.5:1 and the density is near 1000 kg m^(-3). (20000) Varuna may be a rotationally distorted rubble pile, with a weak internal constitution due to fracturing by past impacts. The high specific angular momentum implied by our observations and recent detections of binary Trans-Neptunian Objects both point to an early, intense collisional epoch in which large Trans-Neptunian Objects were about 100 times more abundant than now. In order to maintain a cosmochemically plausible rock:ice mass ratio of about 0.5, Varuna must be internally porous.Comment: 26 pages, 6 figures, 5 tables, accepted to A

Modelling the impact of antimalarial quality on the transmission of sulfadoxine-pyrimethamine resistance in Plasmodium falciparum

Background: The use of poor quality antimalarial medicines, including the use of non-recommended medicines for treatment such as sulfadoxine-pyrimethamine (SP) monotherapy, undermines malaria control and elimination efforts. Furthermore, the use of subtherapeutic doses of the active ingredient(s) can theoretically promote the emergence and transmission of drug resistant parasites. Methods: We developed a deterministic compartmental model to quantify the impact of antimalarial medicine quality on the transmission of SP resistance, and validated it using sensitivity analysis and a comparison with data from Kenya collected in 2006. We modelled human and mosquito population dynamics, incorporating two Plasmodium falciparum subtypes (SP-sensitive and SP-resistant) and both poor quality and good quality (artemether-lumefantrine) antimalarial use. Findings: The model predicted that an increase in human malaria cases, and among these, an increase in the proportion of SP-resistant infections, resulted from an increase in poor quality SP antimalarial use, whether it was full- or half-dose SP monotherapy. Interpretation: Our findings suggest that an increase in poor quality antimalarial use predicts an increase in the transmission of resistance. This highlights the need for stricter control and regulation on the availability and use of poor quality antimalarial medicines, in order to offer safe and effective treatments, and work towards the eradication of malaria

Total versus superficial parotidectomy for stage III melanoma

BackgroundThe primary purpose of this study was to describe the parotid recurrence rates after superficial and total parotidectomy.MethodsA retrospective cohort study was performed on patients with cutaneous melanoma metastatic to the parotid gland who underwent parotidectomy from 1998 through 2014. Primary outcome was parotid bed recurrence. Secondary outcomes were facial nerve function postoperatively and at last follow‐up.ResultsOne hundred twenty‐nine patients were included in the study. Thirty‐four patients (26%) underwent a total parotidectomy and 95 patients underwent superficial parotidectomy. Twelve patients (13%) developed parotid bed recurrence after superficial parotidectomy alone versus zero after total parotidectomy (P = .035). Facial nerve function, clinically detected disease, stage, and adjuvant treatment were not statistically different between the groups (P = .32, .32, .13, and 0.99, respectively).ConclusionParotid bed melanoma recurrence was more common after superficial parotidectomy compared to total parotidectomy, and recurrence resulted in significant facial nerve functional deficit. Our results support total parotidectomy when metastatic melanoma involves the parotid nodal basin.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/137735/1/hed24810_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/137735/2/hed24810.pd

Experimental characterization of photoemission from plasmonic nanogroove arrays

Metal photocathodes are an important source of high-brightness electron beams, ubiquitous in the operation of both large-scale accelerators and table-top microscopes. When the surface of a metal is nano-engineered with patterns on the order of the optical wavelength, it can lead to the excitation and confinement of surface plasmon polariton waves which drive nonlinear photoemission. In this work, we aim to evaluate gold plasmonic nanogrooves as a concept for producing bright electron beams for accelerators via nonlinear photoemission. We do this by first comparing their optical properties to numerical calculations from first principles to confirm our ability to fabricate these nanoscale structures. Their nonlinear photoemission yield is found by measuring emitted photocurrent as the intensity of their driving laser is varied. Finally, the mean transverse energy of this electron source is found using the solenoid scan technique. Our data demonstrate the ability of these cathodes to provide a tenfold enhancement in the efficiency of photoemission over flat metals driven with a linear process. We find that these cathodes are robust and capable of reaching sustained average currents over 100 nA at optical intensities larger than 2 GW/cm$^2$ with no degradation of performance. The emittance of the generated beam is found to be highly asymmetric, a fact we can explain with calculations involving the also asymmetric roughness of the patterned surface. These results demonstrate the use of nano-engineered surfaces as enhanced photocathodes, providing a robust, air-stable source of high average current electron beams with great potential for industrial and scientific applications.Comment: 9 pages, 9 figure

Blame framing and prior knowledge influence moral judgments for people involved in the Tulsa Race Massacre among a combined Oklahoma and UK sample

IntroductionHow an event is framed impacts how people judge the morality of those involved, but prior knowledge can influence information processing about an event, which also can impact moral judgments. The current study explored how blame framing and self-reported prior knowledge of a historical act of racial violence, labeled as Riot, Massacre, or Event, impacted individual’s cumulative moral judgments regarding the groups involved in the Tulsa Race Massacre (Black Tulsans, the Tulsa Police, and White Tulsans).Methods and resultsThis study was collected in two cohorts including undergraduates attending the University of Oklahoma and individuals living in the United Kingdom. Participants were randomly assigned to a blame framing condition, read a factual summary of what happened in Tulsa in 1921, and then responded to various moral judgment items about each group. Individuals without prior knowledge had higher average Likert ratings (more blame) toward Black Tulsans and lower average Likert ratings (less blame) toward White Tulsans and the Tulsa Police compared to participants with prior knowledge. This finding was largest when what participants read was framed as a Massacre rather than a Riot or Event. We also found participants with prior knowledge significantly differed in how they made moral judgments across target groups; those with prior knowledge had lower average Likert ratings (less blame) for Black Tulsans and higher average Likert ratings (more blame) for White Tulsans on items pertaining to causal responsibility, intentionality, and punishment compared to participants without prior knowledge.DiscussionFindings suggest that the effect of blame framing on moral judgments is dependent on prior knowledge. Implications for how people interpret both historical and new events involving harmful consequences are discussed

Now the wars are over: The past, present and future of Scottish battlefields

Battlefield archaeology has provided a new way of appreciating historic battlefields. This paper provides a summary of the long history of warfare and conflict in Scotland which has given rise to a large number of battlefield sites. Recent moves to highlight the archaeological importance of these sites, in the form of Historic Scotland’s Battlefields Inventory are discussed, along with some of the problems associated with the preservation and management of these important cultural sites

Cranial nerve outcomes in regionally recurrent head & neck melanoma after sentinel lymph node biopsy

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/156007/1/lary28243.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/156007/2/lary28243_am.pd