Supplementary article: Paying with Polymer: Developing Canada’s New Bank Notes

In this article, author Charles Spencer reviews the complex process of developing the new series, which represents a dramatic change for Canada. The leading-edge security features made possible by the new substrate, the cost savings of the move to a polymer base and the environmental advantages of the new notes are also examined.

The Effect of Extracurricular Activities on Friendship Diversity: A Look into an Organizational Aspect of College Activities and Cross-Group Relationships

With research supporting the benefits of racial diversity within the workplace and in academic settings, many colleges and universities have begun ramping up efforts to increase racial diversity within their student bodies. Gordon Allport’s contact hypothesis theory (1954) suggests that increasing racial diversity alone does not increase friendship diversity, but that support for cross-group interactions by persons in authority helps to promote meaningful interactions across racial groups. This paper looks at the effects of extracurricular activities on friendship diversity of individuals at the college level by distinguishing between if an individual is selected by authority figures or if that individual self-selects into that activity, after controlling for personal characteristics and high school diversity. The results show a positive correlation between joining an extracurricular activity into which one is selected by members of authority, and that individual’s friendship diversity. However when distinguishing between Whites and non-Whites, the results show that non-white students who are members of selective groups have increased friendship diversity, but Whites do not. As suggested by previous research, race, sex, and high school diversity are also strongly correlated with friendship diversity

Spraying apples : relative merits of liquid and dust applications

Cover title

Three Arabic Letters from North Sumatra of the sixteenth and seventeenth centuries

This article examines three Arabic documents, one from the Sultanate of Samudera-Pasai dated 1516, and two from the Sultanate of Aceh, dated 1602 and 1603, written in the name of Sultan Alauddin Riayat Syah (r.1589–1604). The Samudera-Pasai document represents the earliest surviving manuscript in the Arabic script from Southeast Asia, while the second and third letters are some of the earliest documents that have come down to us from the Aceh sultanate. Despite their historical importance, these documents have not previously been adequately published. This article presents an analysis from a diplomatic, stylistic and philological point of view, comparing them with Malay and Middle Eastern epistolary traditions and examining the significance of the use of Arabic. It also considers the light they shed on diplomatic practice in early modern North Sumatra. An edition and modern English translation of the documents are presented in an appendix, along with a contemporary Portuguese translation of the Pasai letter and the translation by the English Arabist William Bedwell (1561–1632) of the Aceh letter of 1602.PostprintPeer reviewe

Reviewer acknowledgement 2012

CONTRIBUTING REVIEWERS: The Editors of Pediatric Rheumatology would like to thank all our reviewers who have contributed to the journal in Volume 10 (2012)

Apparent Communicative Efficiency in the Lexicon is Emergent

Is language designed for communicative and functional efficiency? G. K. Zipf famously argued that shorter words are more frequent because they are easier to use, thereby resulting in the statistical law that bears his name. Yet, G. A. Miller showed that even a monkey randomly typing at a keyboard, and intermittently striking the space bar, would generate “words” with similar statistical properties. Recent quantitative analyses of human language lexicons (Piantadosi et al., 2012) have revived Zipf\u27s functionalist hypothesis. Ambiguous words tend to be short, frequent, and easy to articulate in language production. Such statistical findings are commonly interpreted as evidence for pressure for efficiency, as the context of language use often provides cues to overcome lexical ambiguity. In this study, we update Miller\u27s monkey thought experiment to incorporate empirically motivated phonological and semantic constraints on the creation of words. We claim that the appearance of communicative efficiency is a spandrel (Gould & Lewontin, 1979), as lexicons formed without the context of language use or reference to communication or efficiency exhibit comparable statistical properties. Furthermore, the updated monkey model provides a good fit for the growth trajectory of English as recorded in the Oxford English Dictionary. Focusing on the history of English words since 1900, we show that lexicons resulting from the monkey model provide a better embodiment of communicative efficiency than the actual lexicon of English. We conclude by arguing for the need to go beyond correlational statistics and to seek direct evidence for the mechanisms that underlie principles of language design

Mixture Density Network Estimation of Continuous Variable Maximum Likelihood Using Discrete Training Samples

Mixture Density Networks (MDNs) can be used to generate probability density functions of model parameters $\boldsymbol{\theta}$ given a set of observables $\mathbf{x}$. In some applications, training data are available only for discrete values of a continuous parameter $\boldsymbol{\theta}$. In such situations a number of performance-limiting issues arise which can result in biased estimates. We demonstrate the usage of MDNs for parameter estimation, discuss the origins of the biases, and propose a corrective method for each issue