Query Complexity of Derivative-Free Optimization

This paper provides lower bounds on the convergence rate of Derivative Free Optimization (DFO) with noisy function evaluations, exposing a fundamental and unavoidable gap between the performance of algorithms with access to gradients and those with access to only function evaluations. However, there are situations in which DFO is unavoidable, and for such situations we propose a new DFO algorithm that is proved to be near optimal for the class of strongly convex objective functions. A distinctive feature of the algorithm is that it uses only Boolean-valued function comparisons, rather than function evaluations. This makes the algorithm useful in an even wider range of applications, such as optimization based on paired comparisons from human subjects, for example. We also show that regardless of whether DFO is based on noisy function evaluations or Boolean-valued function comparisons, the convergence rate is the same

How was it for you? A cross-disciplinary study of ‘troublesome knowledge’ as identified by undergraduate students and lecturers in Geography, Medical Science and Psychology

We carried out a small scale pilot study to determine whether participants would spontaneously identify Threshold Concepts (TC’s) and/or troublesome knowledge during open questioning on the characteristics of their disciplines. Students and lecturers reflected upon both easy and difficult aspects of their studies or teaching practice in either group discussions or one-to-one interviews. We compared students and staff observations both within and between the disciplines we examined (Geography, Medical Sciences and Psychology undergraduate degrees). Our intention was to provide specific examples of TC’s within our three disciplines to inform further discussion of embedding the enhancement theme both in our practice and in the learning experiences of our students. Our working hypothesis was that if TC’s exerted an influence on the teaching and learning experience either negatively or otherwise, then we would find ample evidence supplied in our interviews. What we found was that overwhelmingly our interviewees focussed on generic skills-based aspects of teaching and learning. Only three potential content-specific TC’s were offered spontaneously by students and these were all from the discipline of geography

Trade acceptances, financial reform, and the culture of commercial credit in the United States, 1915-1920

This article examines the nationwide campaign by financial reformers in the 1910s to convince businesses across the United States to abandon established commercial credit practices and use trade acceptances—the quintessential “real bill”—in their stead. The creation of the Federal Reserve System (Fed) and the outbreak of World War I offered a powerful coalition of campaigners the opportunity to forcefully argue that by capitalizing open account credit, trade acceptances fostered good business practices and stabilized the banking and financial systems. These campaigners relied on trade associations to disseminate, and the federal government to legitimize, their message. While some firms obliged, many businesses and banks criticized the campaigners’ arguments, casting trade acceptances as a means of financial centralization and as being contrary to the American culture of credit. Trade acceptances did not supplant promissory notes or trade in the open market and were rarely used by banks to access Fed liquidity. Instead, their legacy lies in their adoption by finance companies in the hope of securing financing for the distribution and mass consumption of consumer durables

Three and Four Region Multi-sector Linear Modelling Using UK Data : Some Preliminary Results

Scotland and Wales have relatively up-to-date, independently generated, IO tables. These can be separated out from a UK national IO table to construct an inter-regional table. We therefore undertake the detailed analysis at this three-region (Scotland, Wales and the Rest of the UK (RUK)) level, where the Rest of the UK is England and Northern Ireland. However, we also construct a more rudimentary four-region (Scotland, Wales, England and Ireland) set of IO and SAM accounts by constructing a separate Northern Ireland accounts. The inter-regional IO and SAM models are produced for the year 1999. This was determined by the availability of consistent data. In Section II we describe the construction of a three-region Input-Output model for the United Kingdom, which includes the regions of Scotland, Wales and the Rest of the UK (RUK). In Section III we extend the three-region model to construct an inter-regional Social Accounting Matrix. Section IV reports some results using the three-region IO and SAM models. In Section V, we generate a four-region IO and SAM model for the UK, which disaggregates Northern Ireland from the Rest of the UK, and provide some results using the four-region IO and SAM models. Section VI offers our conclusions

Genetic Determinism in the Genetics Curriculum: An Exploratory Study of the Effects of Mendelian and Weldonian Emphases

Twenty-first century biology rejects genetic determinism, yet an exaggerated view of the power of genes in the making of bodies and minds remains a problem. What accounts for such tenacity? This article reports an exploratory study suggesting that the common reliance on Mendelian examples and concepts at the start of teaching in basic genetics is an eliminable source of determinism. Undergraduate students who attended a standard “Mendelian approach” university course in introductory genetics on average showed no change in their determinist views about genes. By contrast, students who attended an alternative course which, inspired by the work of a critic of early Mendelism, W. F. R. Weldon (1860-1906), replaced an emphasis on Mendel’s peas with an emphasis on developmental contexts and their role in bringing about phenotypic variability, were less determinist about genes by the end of teaching. Improvements in both the new Weldonian curriculum and the study design are in view for the future

Left Extended Hemihepatectomy With Preservation of Large Inferior Right Hepatic Vein: A Case Report

For hepatic function to be preserved after an extended hemihepatectomy adequate venous drainage of the remaining liver is required. Most metastases close to the confluence of the superior hepatic veins are considered unresectable because hepatic venous outflow after resection would be compromised. In 10–25% of people, the inferior right hepatic vein is of large calibre. Thus the superior hepatic veins may be sacrificed and hepatic function preserved if a large inferior right hepatic vein is present

Friends, Neighbours and Distant Partners: Extending or Decentring Family Relationships?

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From Brazil to Britain: the vicissitudes of participatory budgeting: the importance of context

This project asks: How was it that a participatory practice, originating in the demands of social movements in Brazil, came to fit within the prevailing neoliberal orthodoxy? It explores changes within both neoliberalism and the practice of Participatory Budgeting (PB) itself. It examines PB’s Brazilian origins and the ways in which the process, initially emerging from protest movements, became a formal institutional process and a feature of Brazil’s new democracy, post authoritarian rule. It then explores developments in the process itself within Brazil, before examining its translation to the UK. PB in the UK is explored through an examination of the political climate into which it came to be deployed (i.e. Blair’s New Labour) and two concrete examples of the process (in Manton, Nottinghamshire and Tower Hamlets, London). It focuses on the way in which the discursive environment of operation (the context) impacts upon PB in terms of both its form and its potential. These explorations raise important questions about the roles and relationships of, and between, the state and the citizen in contemporary representative democracy. Arguing that context matters, it demonstrates ways in which an increase in participation may have a positive democratic impact, but this is not a given; an increase in participation may serve to either enhance or diminish democracy. This work makes use of policy analysis and field word. It uses the discourse theory of Laclau and Mouffe as a theoretical guide and asks what can be learnt about PB’s journey, state/citizen roles and relationships, and the relationship between participation and democracy by using this particular theoretical lens

In situ observations of trophic behaviour and locomotion of Princaxelia amphipods (Crustacea, Pardaliscidae) at hadal depths in four West Pacific Trenches

Peer reviewedPublisher PD