A conversation with Serena Corr

On July 19, 1545, King Henry VIII of England watched in dismay as one of his greatest warships, the Mary Rose, sank during the Battle of the Solent in the strait between Britain’s south coast and the Isle of Wight, taking the lives of hundreds of sailors with it. The English fleet eventually won its battle against the French, but the Mary Rose remained on the seabed for centuries. Then, in 1982, the oak vessel was raised in a spectacular feat of underwater archeology. The ship and its artifacts are now kept at the Mary Rose museum in Portsmouth, England, but conservators now face a battle of their own—preserving the ship’s oak timbers from decay. At the American Chemical Society national meeting in August, Serena Corr of the University of Sheffield explained how she is using nanotechnology to help save the Mary Rose. Mark Peplow caught up with Corr to get the latest on the project

A Unified Approach to Spurious Solutions Introduced by Time Discretisation. Part I: Basic Theory

The asymptotic states of numerical methods for initial value problems are examined. In particular, spurious steady solutions, solutions with period 2 in the timestep, and spurious invariant curves are studied. A numerical method is considered as a dynamical system parameterised by the timestep h. It is shown that the three kinds of spurious solutions can bifurcate from genuine steady solutions of the numerical method (which are inherited from the differential equation) as h is varied. Conditions under which these bifurcations occur are derived for Runge–Kutta schemes, linear multistep methods, and a class of predictor-corrector methods in a PE(CE)^M implementation. The results are used to provide a unifying framework to various scattered results on spurious solutions which already exist in the literature. Furthermore, the implications for choice of numerical scheme are studied. In numerical simulation it is desirable to minimise the effect of spurious solutions. Classes of methods with desirable dynamical properties are described and evaluated

Benefits of Using Lesson Study for SoTL, Cross-Disciplinary Research, and Assessment

Lesson study is a technique that helps faculty examine student learning that encourages scholarly teaching. In lesson study, faculty identify a concept and develop a lesson plan to support student learning of the concept. The opportunity to collaborate on lesson development and to examine student learning opens up a space for faculty to exchange ideas about effective teaching. Most faculty do not have opportunities to collaborate on their teaching at this deeper level, but a lesson study project provides guidance for instructors to explore student learning in-depth. This article examines how lesson study provides opportunities for college faculty to engage in cross-disciplinary Scholarship of Teaching and Learning (SoTL) projects. In addition to structuring SoTL projects, lesson study can aid faculty in the development of assessment plans to improve student learning

The Dynamics of the Theta Method

The dynamics of the theta method for arbitrary systems of nonlinear ordinary differential equations are analysed. Two scalar examples are presented to demonstrate the importance of spurious solutions in determining the dynamics of discretisations. A general system of differential equations is then considered. It is shown that the choice θ = ½ does not generate spurious solutions of period 2 in the timestep n. Using bifurcation theory, it is shown that for θ ≠ ½ the theta method does generate spurious solutions of period 2. The existence and form of spurious solutions are examined in the limit △t ⟶ 0. The existence of spurious steady solutions in a predictor-corrector method is proved to be equivalent to the existence of spurious period 2 solutions in the Euler method. The theory is applied to several examples from nonlinear parabolic equations. Numerical continuation is used to trace out the spurious solutions as Lit is varied. Timestepping experiments are presented to demonstrate the effect of the spurious solutions on the dynamics and some complementary theoretical results are proved. In particular, the linear stability restriction △t/△ x^2 ≤ ½ for the Euler method applied to the heat equation is generalised to cope with a nonlinear problem. This naturally introduces a restriction on △t in terms of the initial data; this restriction is necessary to avoid the effect of spurious periodic solutions

Die Agitpropbewegung als Teil der Arbeiterkultur der Weimarer Republik

The advent of next-generation sequencing has brought about an explosion of single nucleotide polymorphism (SNP) data in non-model organisms; however, profiling these SNPs across multiple natural populations still requires substantial time and resources. Results: Here, we introduce two cost-efficient quantitative High Resolution Melting (qHRM) methods for measuring allele frequencies at known SNP loci in pooled DNA samples: the "peaks" method, which can be applied to large numbers of SNPs, and the "curves" method, which is more labor intensive but also slightly more accurate. Using the reef-building coral Acropora millepora, we show that both qHRM methods can recover the allele proportions from mixtures prepared using two or more individuals of known genotype. We further demonstrate advantages of each method over previously published methods; specifically, the "peaks" method can be rapidly scaled to screen several hundred SNPs at once, whereas the "curves" method is better suited for smaller numbers of SNPs. Conclusions: Compared to genotyping individual samples, these methods can save considerable effort and genotyping costs when relatively few candidate SNPs must be profiled across a large number of populations. One of the main applications of this method could be validation of SNPs of interest identified in population genomic studies.Australian Institute of Marine ScienceNational Science Foundation DEB-1054766Cellular and Molecular Biolog

Negotiating stance within discourses of class: reactions to Benefits Street

In this article, we examine the way that audiences respond to particular representations of poverty. Using clips from the Channel 4 television programme Benefits Street we conducted focus groups in four locations across the UK, working with people from different socioeconomic backgrounds who had different experiences with the benefits system. Benefits Street (2014) is an example of reality television where members of the public are followed by film crews as they perform everyday tasks and routines. Our choice to focus on this particular programme was prompted by the huge media response that it received when it was broadcast; Benefits Street generated 950 complaints to regulatory watchdog Ofcom (2014) and was referred to as ‘poverty porn’ (Clark, 2014). We focus on the way that viewers of this programme produce assessments of those on benefits, analysing the discursive strategies used by our participants when evaluating representations of those on benefits. Specifically, we consider how the participants in our study construct their own stance and attribute stance to others through naming and agency practices, the negotiation of opinion, and stake inoculation. We invited our participants to judge the people they saw on screen, but they went beyond this. They used clips of the programme as stimuli to collaboratively construct an overarchingly-negative stereotype of those on benefits. We conclude that Benefits Street is not just an entertainment programme, but is rather a site for ideological construction and the perpetuation of existing stereotypes about benefit claimants. The programme (and others like it) invites negative evaluations of those on benefits and is thus a worthy site for critical linguistic analysis

Re-reading in Stylistics

Cognitive stylistics is primarily concerned with the cognitive processes – mental simulations – experienced by readers. Most cognitive stylisticians agree that experiences of reading texts are dynamic and flexible. Changes in the context of reading, our attentional focus on a given day, our extra background knowledge about the text, and so on, are all factors that contribute to our experience of a fictional world. A second reading of a text is a different experience to a first reading. As researchers begin to systematically distinguish between the ‘solitary’ and ‘social’ readings that constitute reading as a phenomenon (Peplow et al., 2016), the relationship between multiple readings and the nature of their processing become increasingly pertinent. In order to explore this relationship, firstly we examine the different ways in which re-reading has previously been discussed in stylistics, grounding our claims in an empirical analysis of articles published in key stylistics journals over the past two decades. Next, we draw on reader response data from an online questionnaire in order to assess the role of re-reading and the motivations that underpin it. Finally, we describe an exercise for the teaching of cognitive stylistics, specifically applying schema theory in literary linguistic analysis (Cook, 1994), which illustrates the need to distinguish between readings as part of an analysis. Through these three sections we argue that our experiences of texts should be considered diachronically, and propose that the different readings that make up an analysis of a text should be given greater attention in stylistic research and teaching