The Impact of External Audience on Second Graders\u27 Writing Quality

The overarching purpose of writing is to communicate; as such, the intended audience is a critical consideration for writers. However, elementary school writing instruction commonly neglects the role of the audience. Typically, children are asked to compose a piece of text without a specific audience that is usually evaluated by the classroom teacher. Previous studies have found a relationship between audience specification and higher quality writing among older children; this study examines the impact of audience specification on young children’s writing. Using a within-subjects design, the study compared writing quality when second-grade students wrote for internal versus external audiences and found that children are more likely to produce higher quality writing when writing for an external audience than when writing for their teacher

Modular Frobenius manifolds and their invariant flows

The space of Frobenius manifolds has a natural involutive symmetry on it: there exists a map $I$ which send a Frobenius manifold to another Frobenius manifold. Also, from a Frobenius manifold one may construct a so-called almost dual Frobenius manifold which satisfies almost all of the axioms of a Frobenius manifold. The action of $I$ on the almost dual manifolds is studied, and the action of $I$ on objects such as periods, twisted periods and flows is studied. A distinguished class of Frobenius manifolds sit at the fixed point of this involutive symmetry, and this is made manifest in certain modular properties of the various structures. In particular, up to a simple reciprocal transformation, for this class of modular Frobenius manifolds, the flows are invariant under the action of $I\,.

Bayesian Model Averaging in Vector Autoregressive Processes with an Investigation of Stability of the US Great Ratios and Risk of a Liquidity Trap in the USA, UK and Japan.

A Bayesian model averaging procedure is presented within the class of vector autoregressive (VAR) processes and applied to two empirical issues. First, stability of the Great Ratios in U.S. macro-economic time series is investigated, together with the presence and effects of permanent shocks. Measures on manifolds are employed in order to elicit uniform priors on subspaces defined by particular structural features of linear VARs. Second, the VAR model is extended to include a smooth transition function in a (monetary) equation and stochastic volatility in the disturbances. The risk of a liquidity trap in the USA, UK and Japan is evaluated, together with the expected cost of a policy adjustment of central banks. Posterior probabilities of different models are evaluated usingMarkov chainMonte Carlo techniques.

Evidence on a DSGE Business Cycle model subject to Neutral and Investment-Specific Technology Shocks using Bayesian Model Averaging

The empirical support for a DSGE type of real business cycle model with two technology shocks is evaluated using a Bayesian model averaging procedure that makes use of a finite mixture of many models within the class of vector autoregressive (VAR) processes. The linear VAR model is extended to permit equilibrium restrictions and restrictions on long-run responses to technology shocks apart from having a range of lag structures and deterministic processes. These model features are weighted as posterior probabilites and computed using MCMC and analytical methods. Uncertainty exists as to the most appropriate model for our data, with five models receiving significant support. The model set used has substantial implications for the results obtained. We do find support for a number of features implied by the real business cycle model. Business cycle volatility seems more due to investment specific technology shocks than neutral technology shocks and this result is robust to model specification. These techonolgy schocks appear to account for all stochastic trends in our system after 1984. we provide evidence on the uncertainty bands associated with these results.

Model Uncertainty and Bayesian Model Averaging in Vector Autoregressive Processes

Economic forecasts and policy decisions are often informed by empirical analysis based on econometric models. However, inference based upon a single model, when several viable models exist, limits its usefulness. Taking account of model uncertainty, a Bayesian model averaging procedure is presented which allows for unconditional inference within the class of vector autoregressive (VAR) processes. Several features of VAR process are investigated. Measures on manifolds are employed in order to elicit uniform priors on subspaces defined by particular structural features of VARs. The features considered are the number and form of the equilibrium economic relations and deterministic processes. Posterior probabilities of these features are used in a model averaging approach for forecasting and impulse response analysis. The methods are applied to investigate stability of the "Great Ratios" in U.S. consumption, investment and income, and the presence and effects of permanent shocks in these series. The results obtained indicate the feasibility of the proposed method.Posterior probability; Grassman manifold; Orthogonal group; Cointegration; Model averaging; Stochastic trend; Impulse response; Vector autoregressive model.

Improper priors with well defined Bayes Factors

While some improper priors have attractive properties, it is generally claimed that Bartlett’s paradox implies that using improper priors for the parameters in alternative models results in Bayes factors that are not well defined, thus preventing model comparison in this case. In this paper we demonstrate, using well understood principles underlying what is already common practice, that this latter result is not generally true and so expand the class of priors that may be used for computing posterior odds to two classes of improper priors: the shrink age prior; and a prior based upon a nesting argument. Using a new representation of the issue of undefined Bayes factors, we develop classes of improper priors from which well defined Bayes factors result. However, as the use of such priors is not free of problems, we include discussion on the issues with using such priors for model comparison.Improper prior; Bayes factor; marginal likelihood; shrinkage prior; measure

The dynamics of copper intercalated molybdenum ditelluride

Layered transition metal dichalcogenides are emerging as key materials in nanoelectronics and energy applications. Predictive models to understand their growth, thermomechanical properties and interactions with metals are needed in order to accelerate their incorporation into commercial products. Interatomic potentials enable large-scale atomistic simulations at the device level, beyond the range of applications of first principle methods. We present a ReaxFF reactive force field to describe molybdenum ditelluride and its interactions with copper. We optimized the force field parameters to describe the properties of layered MoTe2 in various phases, the intercalation of Cu atoms and clusters within its van der Waals gap, including a proper description of energetics, charges and mechanical properties. The training set consists of an extensive set of first principle calculations computed from density functional theory. We use the force field to study the adhesion of a single layer MoTe2 on a Cu(111) surface and the results are in good agreement with density functional theory, even though such structures were not part of the training set. We characterized the mobility of the Cu ions intercalated into MoTe2 under the presence of an external electric fields via molecular dynamics simulations. The results show a significant increase in drift velocity for electric fields of approximately 0.4 V/A and that mobility increases with Cu ion concentration.Comment: 21 pages, 9 Figure

Differing preferences of Antarctic soil nematodes for microbial prey

We tested the preferences of three nematode taxa, Geomonhystera villosa, Plectus spp. and Teratocephalus spp., extracted from moss at Signy Island in the Maritime Antarctic, for two microalgae, three microfungi and six heterotrophic bacteria, each also from soils at Signy Island. Choice test experiments on water agar medium, in which nematodes were enumerated in wells containing microbes at 24 and 48 h, indicated that there were differing preferences between nematodes for distinct prey. G. villosa was significantly attracted to the alga Chlorella cf. minutissima and the fungus Mortierella hyalina, and was more attracted to all algae and fungi than either of the other two nematodes. Both G. villosa and Teratocephalus spp. were attracted to an actinobacterium. Plectus spp. were significantly attracted to the alga Stichococcus bacillaris and bacteria with close taxonomic affinities to Arthrobacter, Pseudomonas and Polaromonas. Experiments using 0.5 μm diameter fluorescent beads indicated significantly increased ingestion by nematodes in the presence of each of these microbes compared with controls, except by Plectus spp. in the presence of S. bacillaris. We conclude that complex trophic interactions may occur in apparently simple Antarctic soil food webs

Transformation through learning: Education about, for, and as sustainability

The United Nations foregrounds education as a means to achieving the Sustainable Development Goals (https://sdgs.un.org/goals). In this conceptual paper, we argue education must offer learning that is transformative to better prepare learners to respond to the current global challenges. We argue that the dominant educational approaches fall short of realizing learners' potential for transformation toward sustainability. Focusing on the region of Southeast Asia we draw on educator experiences working with and at the Green School (Indonesia) and United World College (Singapore) to map some of their educational successes and identify some of the key processes and conditions that have contributed to those successes. The potential that exists in the context of independent international schools maybe a relevant factor in their success. We see the lessons that can be learned from these examples as useful in other school contexts. We draw on three sequential pedagogical development phases of learning in engaging with sustainability: namely, Learning about Sustainability, Learning for Sustainability (LfS), and Learning as Sustainability. We argue that the third transformative learning phase, Learning as Sustainability (which also incorporates processes of learning about and for sustainability) offers the best fertile ground for engaging learners as active social change agents within and outside of the learning environment. We see these learning phases as all interconnected, dynamic, and fluid rather than a formulaic progression. This paper contributes to advancing schools toward a perspective on education that reflects an ecological approach toward sustainability and support educators to better integrate education as sustainability in their learning activities. It is worth mentioning that changes in the school that reflect an ecological approach does not guarantee that the experience of the learner will result in transformative Learning as Sustainability. Instead, it is our contention that attaining a clear understanding of these learning processes empowers educators to facilitate an environment by identifying and incorporating the necessary conditions required to inspire deep ecological transformation, thus increasing the potential to arrive at Learning as Sustainability

Duality for Jacobi group orbit spaces and elliptic solutions of the WDVV equations

From any given Frobenius manifold one may construct a so-called dual structure which, while not satisfying the full axioms of a Frobenius manifold, shares many of its essential features, such as the existence of a prepotential satisfying the WDVV equations of associativity. Jacobi group orbit spaces naturally carry the structures of a Frobenius manifold and hence there exists a dual prepotential. In this paper this dual prepotential is constructed and expressed in terms of the elliptic polylogarithm function of Beilinson and Levin