Visualising Music with Impromptu

This paper discusses our experiments with a method of creating visual representations of music using a graphical library for Impromptu that emulates and builds on Logo’s turtle graphics. We explore the potential and limitations of this library for visualising music, and describe some ways in which this simple system can be utilised to assist the musician by revealing musical structure are demonstrated

Spanning trees of 3-uniform hypergraphs

Masbaum and Vaintrob's "Pfaffian matrix tree theorem" implies that counting spanning trees of a 3-uniform hypergraph (abbreviated to 3-graph) can be done in polynomial time for a class of "3-Pfaffian" 3-graphs, comparable to and related to the class of Pfaffian graphs. We prove a complexity result for recognizing a 3-Pfaffian 3-graph and describe two large classes of 3-Pfaffian 3-graphs -- one of these is given by a forbidden subgraph characterization analogous to Little's for bipartite Pfaffian graphs, and the other consists of a class of partial Steiner triple systems for which the property of being 3-Pfaffian can be reduced to the property of an associated graph being Pfaffian. We exhibit an infinite set of partial Steiner triple systems that are not 3-Pfaffian, none of which can be reduced to any other by deletion or contraction of triples. We also find some necessary or sufficient conditions for the existence of a spanning tree of a 3-graph (much more succinct than can be obtained by the currently fastest polynomial-time algorithm of Gabow and Stallmann for finding a spanning tree) and a superexponential lower bound on the number of spanning trees of a Steiner triple system.Comment: 34 pages, 9 figure

New insights into the effects of several environmental parameters on the relative fitness of a numerically dominant class of evolved niche specialist

Adaptive radiation in bacteria has been investigated using Wrinkly Spreaders (WS), a morphotype which colonises the air-liquid (A-L) interface of static microcosms by biofilm formation with a significant fitness advantage over competitors growing lower down in the O2-limited liquid column. Here, we investigate several environmental parameters which impact the ecological opportunity that the Wrinkly Spreaders exploit in this model system. Manipulation of surface area/volume ratios suggests that the size of the WS niche was not as important as the ability to dominate the A-L interface and restrict competitor growth. The value of this niche to the Wrinkly Spreaders, as determined by competitive fitness assays, was found to increase as O2 flux to the A-L interface was reduced, confirming that competition for O2 was the main driver of WS fitness. The effect of O2 on fitness was also found to be dependent on the availability of nutrients, reflecting the need to take up both for optimal growth. Finally, the meniscus trap, a high-O2 region formed by the interaction of the A-L interface with the vial walls, was also important for fitness during the early stages of biofilm formation. These findings reveal the complexity of this seemingly simple model system and illustrate how changes in environmental physicality alter ecological opportunity and the fitness of the adaptive morphotype

Tariff Rate Quotas and New Zealand’s Meat and Dairy Trade

The tariff rate quota (TRQ) system was formalised in the Uruguay Round with the aim of maintaining and improving market access for agricultural products. Under this system, a lower tariff rate is applied to imports up to the quota limit, with a higher (and often prohibitive) tariff rate levied on products imported beyond this quota. However, the success of the TRQ system has been limited, with dairy and meat products in particular still facing relatively high barriers to international trade. In this paper, we examine the impact of the TRQ system on New Zealand’s meat and dairy trade. We draw together theoretical and empirical insights and present preliminary findings arising from interviews with key stakeholders. In particular, we examine whether the TRQ system has achieved its objectives from the perspective of the dairy and meat sectors in New Zealand and we analyse problems that appear to exist with the system. We also examine implications of reform of the TRQ system, including lower in- and over-quota rates, increased quota limits and more transparent and efficient administration methods.Agribusiness, Agricultural and Food Policy, Crop Production/Industries, Environmental Economics and Policy, Farm Management, International Relations/Trade, Land Economics/Use, Livestock Production/Industries,

Language counts: Early language mediates the relationship between parent education and children\u27s math ability

Children\u27s early math skills have been hailed as a powerful predictor of academic success. Disparities in socioeconomic context, however, also have dramatic consequences on children\u27s learning. It is therefore critical to investigate both of these distinct contributors in order to better understand the early foundations of children\u27s academic outcomes. This study tests an integrated model of children\u27s developing math ability so as to (1) identify the specific skills and abilities most clearly linked to early math achievement and (2) measure the influence of children\u27s socioeconomic context on each of these skills. We first evaluated the early vocabulary, number word knowledge (knower level), and Approximate Number System (ANS) acuity of a diverse group of preschoolers. Then, approximately 1 year later as they entered Kindergarten, we administered a test of early math achievement. We find that children\u27s early language (general vocabulary and number word knowledge) fully mediates the relationship between parent education and math ability. Additionally, number word knowledge mediates the relationship between ANS acuity and early math. We argue that increased focus on number word knowledge, as well as general vocabulary, may help to minimize disparities in math ability as children enter kindergarten. We also highlight the role of parent education on children\u27s learning and note that this may be an important locus for intervention

The effect of school resources on pupil attainment: a multilevel simultaneous equation modelling approach

Improving educational achievement in UK schools is a priority, and of particular concern is the low achievement of specific groups, such as those from lower socio-economic backgrounds. An obvious question is whether we should be improving the outcomes of these students by spending more on their education. The literature on the effect of educational spending on pupil achievement has a number of methodological difficulties, in particular the endogeneity of school resource levels, and the intra-school correlations in student responses. In this paper, we adopt a multilevel simultaneous equation modelling approach to assess the impact of school resources on student attainment at age 14. This paper is the first to apply a simultaneous equation model to estimate the impact of school resources on pupil achievement, using the newly available National Pupil Database (NPDB)

Constraints on Neutron Star Crusts From Oscillations in Giant Flares

We show that the fundamental seismic shear mode, observed as a quasi-periodic oscillation in giant flares emitted by highly-magnetized neutron stars, is particularly sensitive to the nuclear physics of the crust. The identification of an oscillation at ~ 30 Hz as the fundamental crustal shear mode requires a nuclear symmetry energy that depends very weakly on density near saturation. If the nuclear symmetry energy varies more strongly with density, then lower frequency oscillations, previously identified as torsional Alfven modes of the fluid core, could instead be associated with the crust. If this is the case, then future observations of giant flares should detect oscillations at around 18 Hz. An accurate measurement of the neutron skin thickness of lead will also constrain the frequencies predicted by the model.Comment: 5 pages, 3 figures; Version to appear in Phys. Rev. Let

Listening between the Lines: Learning Personal Attributes from Conversations

Open-domain dialogue agents must be able to converse about many topics while incorporating knowledge about the user into the conversation. In this work we address the acquisition of such knowledge, for personalization in downstream Web applications, by extracting personal attributes from conversations. This problem is more challenging than the established task of information extraction from scientific publications or Wikipedia articles, because dialogues often give merely implicit cues about the speaker. We propose methods for inferring personal attributes, such as profession, age or family status, from conversations using deep learning. Specifically, we propose several Hidden Attribute Models, which are neural networks leveraging attention mechanisms and embeddings. Our methods are trained on a per-predicate basis to output rankings of object values for a given subject-predicate combination (e.g., ranking the doctor and nurse professions high when speakers talk about patients, emergency rooms, etc). Experiments with various conversational texts including Reddit discussions, movie scripts and a collection of crowdsourced personal dialogues demonstrate the viability of our methods and their superior performance compared to state-of-the-art baselines.Comment: published in WWW'1