4,303 research outputs found
An effective likelihood-free approximate computing method with statistical inferential guarantees
Approximate Bayesian computing is a powerful likelihood-free method that has
grown increasingly popular since early applications in population genetics.
However, complications arise in the theoretical justification for Bayesian
inference conducted from this method with a non-sufficient summary statistic.
In this paper, we seek to re-frame approximate Bayesian computing within a
frequentist context and justify its performance by standards set on the
frequency coverage rate. In doing so, we develop a new computational technique
called approximate confidence distribution computing, yielding theoretical
support for the use of non-sufficient summary statistics in likelihood-free
methods. Furthermore, we demonstrate that approximate confidence distribution
computing extends the scope of approximate Bayesian computing to include
data-dependent priors without damaging the inferential integrity. This
data-dependent prior can be viewed as an initial `distribution estimate' of the
target parameter which is updated with the results of the approximate
confidence distribution computing method. A general strategy for constructing
an appropriate data-dependent prior is also discussed and is shown to often
increase the computing speed while maintaining statistical inferential
guarantees. We supplement the theory with simulation studies illustrating the
benefits of the proposed method, namely the potential for broader applications
and the increased computing speed compared to the standard approximate Bayesian
computing methods
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Conceptualizing Literature Pedagogy: World, Global, and Cosmopolitan Orientations to Teaching Literature in English
While there is a wealth of research about literary history, literary genres, and the nature of the literary text, research on approaches to teaching literature that shape the interpretation and reception of the text is insufficient. My overarching aim in this study is to conceptualize literature pedagogy across the historical evolution of the field of literature in English. Underlying literature pedagogy are beliefs about the good of teaching literature. Consequently, the teaching of literature is a form of values education. In the late eighteenth century, the teaching of literature was used to propagate ideological values of the nation-state when the discipline of English literature was institutionalized in public education. From the early twentieth century onwards, various global-political and disciplinary movements led to a shift towards a post nation-state model of values education emphasizing education for world, global, and cosmopolitan values. One way to understand the different values underlying literature pedagogy is to examine beliefs about the good of teaching literature as these are manifested in concepts that demonstrate various orientations to teaching literature. Given that the formal institutionalization of English literature and its subsequent re-configurations, in the form of literature in English, were conditioned by the phenomenon of globalization, the study explores how approaches to teaching literature have responded to four waves of globalization from the late eighteenth to the twenty-first century. Rather than focus on events, I employ a historical-paradigmatic analysis to analyze conceptual turns or moments in a historical period when particular concepts gain dominance. The advantage of this analysis is two-fold. First, it avoids examining history in terms of events so that more attention is paid to the history of ideas and second, paradigms disrupt the notion of a linear history which then allows for historical overlaps. In order to locate concepts that gain dominance, three domains are analyzed within each historical period - global waves, disciplinary movements, and philosophical contributions. The objectives of the study are driven by two research questions: (1) How do global waves, disciplinary movements, and philosophical contributions, from the late eighteenth century to the present, contribute to characterizing various beliefs about the good of teaching literature? (2) How do these beliefs orient approaches to teaching literature? The study argues that various global waves across history have facilitated the interrelation and dominance of key concepts that provide insights into beliefs about the good of teaching literature. From these concepts, four orientations emerge - nationalist-oriented, world-oriented, global-oriented, and cosmopolitan-oriented approaches to teaching literature. These approaches serve to recognize a key role for the teaching literature in educating for values beyond the ideologies of the nation-state. The study has implications for literature teachers in the hopes that it would broaden their consciousness and repertoire of pedagogical approaches as well as equip them to be more purposeful in their applications of these to the classroom. More importantly, an understanding of these orientations would serve to develop a greater sense of ethical agency in teachers as they work towards cultivating a hospitable imagination in their students
Primordia initiation of mushroom (Agaricus bisporus) strains on axenic casing materials
The mushroom (Agaricus bisporus) has a
requirement for a ‘‘casing layer’’ that has specific
physical, chemical and microbiological properties
which stimulate and promote the initiation of primordia.
Some of these primordia then may develop
further into sporophores, involving differentiation of
tissue. Wild and commercial strains of A. bisporus
were cultured in axenic and nonaxenic microcosms,
using a rye grain substrate covered by a range of organic
and inorganic casing materials. In axenic culture,
A. bisporus (commercial strain A15) was capable
of producing primordia and mature sporophores on
charcoal (wood and activated), anthracite coal, lignite
and zeolite, but not on bark, coir, peat, rockwool,
silica or vermiculite. Of six strains tested, only
the developmental variant mutant, B430, produced
rudimentary primordia on axenic peat-based casing
material. However, none of these rudimentary primordia
developed differentiated tissues or beyond 4
mm diameter, either on axenic casing material in the
microcosms or in larger-scale culture. In larger-scale,
nonaxenic culture, strain B430 produced severely
malformed but mature sporophores in similar numbers
to those of other strains. Typically, 3–6% of primordia
developed into mature sporophores, but significant
differences in this proportion, as well as in
the numbers of primordia produced, were recorded
between 12 A. bisporus strains
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