18,527 research outputs found
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
Experimental Control and Characterization of Autophagy in Drosophila
Insects such as the fruit fly Drosophila melanogaster, which fundamentally reorganize their body plan during metamorphosis, make extensive use of autophagy for their normal development and physiology. In the fruit fly, the hepatic/adipose organ known as the fat body accumulates nutrient stores during the larval feeding stage. Upon entering metamorphosis, as well as in response to starvation, these nutrients are mobilized through a massive induction of autophagy, providing support to other tissues and organs during periods of nutrient deprivation. High levels of autophagy are also observed in larval tissues destined for elimination, such as the salivary glands and larval gut. Drosophila is emerging as an important system for studying the functions and regulation of autophagy in an in vivo setting. In this chapter we describe reagents and methods for monitoring autophagy in Drosophila, focusing on the larval fat body. We also describe methods for experimentally activating and inhibiting autophagy in this system and discuss the potential for genetic analysis in Drosophila to identify novel genes involved in autophagy
Counting Arithmetical Structures on Paths and Cycles
Let G be a finite, connected graph. An arithmetical structure on G is a pair of positive integer vectors d, r such that (diag (d) - A) r=0 , where A is the adjacency matrix of G. We investigate the combinatorics of arithmetical structures on path and cycle graphs, as well as the associated critical groups (the torsion part of the cokernels of the matrices (diag (d) - A)). For paths, we prove that arithmetical structures are enumerated by the Catalan numbers, and we obtain refined enumeration results related to ballot sequences. For cycles, we prove that arithmetical structures are enumerated by the binomial coefficients ((2n-1)/(n-1)) , and we obtain refined enumeration results related to multisets. In addition, we determine the critical groups for all arithmetical structures on paths and cycles
What have we already learned from the CMB?
The COBE satellite, and the DMR experiment in particular, was extraordinarily
successful. However, the DMR results were announced about 7 years ago, during
which time a great deal more has been learned about anisotropies in the Cosmic
Microwave Background (CMB). The CMB experiments currently being designed and
built, including long-duration balloons, interferometers, and two space
missions, promise to address several fundamental cosmological issues. We
present our evaluation of what we already know, what we are beginning to learn
now, and what the future may bring.Comment: 20 pages, 3 figures. Changes to match version accepted by PAS
Counting Arithmetical Structures on Paths and Cycles
Let G be a finite, connected graph. An arithmetical structure on G is a pair of positive integer vectors d, r such that (diag (d) - A) r=0 , where A is the adjacency matrix of G. We investigate the combinatorics of arithmetical structures on path and cycle graphs, as well as the associated critical groups (the torsion part of the cokernels of the matrices (diag (d) - A)). For paths, we prove that arithmetical structures are enumerated by the Catalan numbers, and we obtain refined enumeration results related to ballot sequences. For cycles, we prove that arithmetical structures are enumerated by the binomial coefficients ((2n-1)/(n-1)) , and we obtain refined enumeration results related to multisets. In addition, we determine the critical groups for all arithmetical structures on paths and cycles
Pattern of Reaction Diffusion Front in Laminar Flows
Autocatalytic reaction between reacted and unreacted species may propagate as
solitary waves, namely at a constant front velocity and with a stationary
concentration profile, resulting from a balance between molecular diffusion and
chemical reaction. The effect of advective flow on the autocatalytic reaction
between iodate and arsenous acid in cylindrical tubes and Hele-Shaw cells is
analyzed experimentally and numerically using lattice BGK simulations. We do
observe the existence of solitary waves with concentration profiles exhibiting
a cusp and we delineate the eikonal and mixing regimes recently predicted.Comment: 4 pages, 3 figures. This paper report on experiments and simulations
in different geometries which test the theory of Boyd Edwards on flow
advection of chemical reaction front which just appears in PRL (PRL Vol
89,104501, sept2002
Maximum Likelihood Estimation for Single Particle, Passive Microrheology Data with Drift
Volume limitations and low yield thresholds of biological fluids have led to
widespread use of passive microparticle rheology. The mean-squared-displacement
(MSD) statistics of bead position time series (bead paths) are either applied
directly to determine the creep compliance [Xu et al (1998)] or transformed to
determine dynamic storage and loss moduli [Mason & Weitz (1995)]. A prevalent
hurdle arises when there is a non-diffusive experimental drift in the data.
Commensurate with the magnitude of drift relative to diffusive mobility,
quantified by a P\'eclet number, the MSD statistics are distorted, and thus the
path data must be "corrected" for drift. The standard approach is to estimate
and subtract the drift from particle paths, and then calculate MSD statistics.
We present an alternative, parametric approach using maximum likelihood
estimation that simultaneously fits drift and diffusive model parameters from
the path data; the MSD statistics (and consequently the compliance and dynamic
moduli) then follow directly from the best-fit model. We illustrate and compare
both methods on simulated path data over a range of P\'eclet numbers, where
exact answers are known. We choose fractional Brownian motion as the numerical
model because it affords tunable, sub-diffusive MSD statistics consistent with
typical 30 second long, experimental observations of microbeads in several
biological fluids. Finally, we apply and compare both methods on data from
human bronchial epithelial cell culture mucus.Comment: 29 pages, 12 figure
New Zealand athletes' attitudes towards seeking sport psychology consultation
The aim of this study was to use the Sport Psychology Attitudes-Revised (SPA-R) questionnaire (Martin, Kellman, Lavallee & Page, 2002) to develop an understanding of the attitudes elite New Zealand athletes (N = 112) hold towards sport psychology so that services can be tailored to accommodate these views. The influence of athlete characteristics such as nationality, gender, age, level of competition achieved, and previous use of sport psychology on attitudes was explored. Further, the SPA-R was used as a measure of attitudes within the Theory of Reasoned Action (TRA; Ajzen & Fishbein, 1980) and Theory Planned Behaviour (TPB; Ajzen, 1985, 1991), and integrated with measures of subjective norm and perceived behavioural control to investigate the influence of these variables on predicting athletes' intention to use sport psychology. Results suggested that New Zealand athletes generally held positive attitudes regarding sport psychology, with gender and previous experience of sport psychology significantly influencing attitudes. Regression analyses indicated that the TPB was a better model than the TRA for predicting intention, and the variables predicted 39.7% of variance in intention to use sport psychology. The only SPA-R subscale that contributed significantly was confidence in sport psychology, and perceived behavioural control and subjective norm also contributed significantly. These findings suggest the SPA-R may have limited value in predicting intentions, although the TPB could provide a useful theoretical framework to direct interventions aimed at increasing athletes' intention to use sport psychology
Theory-Based Design and Development of a Socially Connected, Gamified Mobile App for Men About Breastfeeding (Milk Man)
BACKGROUND: Despite evidence of the benefits of breastfeeding, <15% of Australian babies are exclusively breastfed to the recommended 6 months. The support of the father is one of the most important factors in breastfeeding success, and targeting breastfeeding interventions to the father has been a successful strategy in previous research. Mobile technology offers unique opportunities to engage and reach populations to enhance health literacy and healthy behavior. OBJECTIVE: The objective of our study was to use previous research, formative evaluation, and behavior change theory to develop the first evidence-based breastfeeding app targeted at men. We designed the app to provide men with social support and information aiming to increase the support men can offer their breastfeeding partners. METHODS: We used social cognitive theory to design and develop the Milk Man app through stages of formative research, testing, and iteration. We held focus groups with new and expectant fathers (n=18), as well as health professionals (n=16), and used qualitative data to inform the design and development of the app. We tested a prototype with fathers (n=4) via a think-aloud study and the completion of the Mobile Application Rating Scale (MARS).RESULTS: Fathers and health professionals provided input through the focus groups that informed the app development. The think-aloud walkthroughs identified 6 areas of functionality and usability to be addressed, including the addition of a tutorial, increased size of text and icons, and greater personalization. Testers rated the app highly, and the average MARS score for the app was 4.3 out of 5. CONCLUSIONS: To our knowledge, Milk Man is the first breastfeeding app targeted specifically at men. The development of Milk Man followed a best practice approach, including the involvement of a multidisciplinary team and grounding in behavior change theory. It tested well with end users during development. Milk Man is currently being trialed as part of the Parent Infant Feeding Initiative (ACTRN12614000605695)
Boomerang returns unexpectedly
Experimental study of the anisotropy in the cosmic microwave background (CMB)
is gathering momentum. The eagerly awaited Boomerang results have lived up to
expectations. They provide convincing evidence in favor of the standard
paradigm: the Universe is close to flat and with primordial fluctuations which
are redolent of inflation. Further scrutiny reveals something even more
exciting however -- two hints that there may be some unforeseen physical
effects. Firstly the primary acoustic peak appears at slightly larger scales
than expected. Although this may be explicable through a combination of mundane
effects, we suggest it is also prudent to consider the possibility that the
Universe might be marginally closed. The other hint is provided by a second
peak which appears less prominent than expected. This may indicate one of a
number of possibilities, including increased damping length or tilted initial
conditions, but also breaking of coherence or features in the initial power
spectrum. Further data should test whether the current concordance model needs
only to be tweaked, or to be enhanced in some fundamental way.Comment: 11 pages, 3 figures, final version accepted by Ap
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