Optimal Data-Dependent Hashing for Approximate Near Neighbors

We show an optimal data-dependent hashing scheme for the approximate near neighbor problem. For an $n$-point data set in a $d$-dimensional space our data structure achieves query time $O(d n^{\rho+o(1)})$ and space $O(n^{1+\rho+o(1)} + dn)$, where $\rho=\tfrac{1}{2c^2-1}$ for the Euclidean space and approximation $c>1$. For the Hamming space, we obtain an exponent of $\rho=\tfrac{1}{2c-1}$. Our result completes the direction set forth in [AINR14] who gave a proof-of-concept that data-dependent hashing can outperform classical Locality Sensitive Hashing (LSH). In contrast to [AINR14], the new bound is not only optimal, but in fact improves over the best (optimal) LSH data structures [IM98,AI06] for all approximation factors $c>1$. From the technical perspective, we proceed by decomposing an arbitrary dataset into several subsets that are, in a certain sense, pseudo-random.Comment: 36 pages, 5 figures, an extended abstract appeared in the proceedings of the 47th ACM Symposium on Theory of Computing (STOC 2015

The Boltzmann factor, DNA melting, and Brownian ratchets: Topics in an introductory physics sequence for biology and premedical students

Three, interrelated biologically-relevant examples of biased random walks are presented: (1) A model for DNA melting, modelled as DNA unzipping, which provides a way to illustrate the role of the Boltzmann factor in a venue well-known to biology and pre-medical students; (2) the activity of helicase motor proteins in unzipping double-stranded DNA, for example, at the replication fork, which is an example of a Brownian ratchet; (3) force generation by actin polymerization, which is another Brownian ratchet, and for which the force and actin-concentration dependence of the velocity of actin polymerization is determined

Bridging Physics and Biology Teaching through Modeling

As the frontiers of biology become increasingly interdisciplinary, the physics education community has engaged in ongoing efforts to make physics classes more relevant to life sciences majors. These efforts are complicated by the many apparent differences between these fields, including the types of systems that each studies, the behavior of those systems, the kinds of measurements that each makes, and the role of mathematics in each field. Nonetheless, physics and biology are both sciences that rely on observations and measurements to construct models of the natural world. In the present theoretical article, we propose that efforts to bridge the teaching of these two disciplines must emphasize shared scientific practices, particularly scientific modeling. We define modeling using language common to both disciplines and highlight how an understanding of the modeling process can help reconcile apparent differences between the teaching of physics and biology. We elaborate how models can be used for explanatory, predictive, and functional purposes and present common models from each discipline demonstrating key modeling principles. By framing interdisciplinary teaching in the context of modeling, we aim to bridge physics and biology teaching and to equip students with modeling competencies applicable across any scientific discipline.Comment: 10 pages, 2 figures, 3 table

NEXUS/Physics: An interdisciplinary repurposing of physics for biologists

In response to increasing calls for the reform of the undergraduate science curriculum for life science majors and pre-medical students (Bio2010, Scientific Foundations for Future Physicians, Vision & Change), an interdisciplinary team has created NEXUS/Physics: a repurposing of an introductory physics curriculum for the life sciences. The curriculum interacts strongly and supportively with introductory biology and chemistry courses taken by life sciences students, with the goal of helping students build general, multi-discipline scientific competencies. In order to do this, our two-semester NEXUS/Physics course sequence is positioned as a second year course so students will have had some exposure to basic concepts in biology and chemistry. NEXUS/Physics stresses interdisciplinary examples and the content differs markedly from traditional introductory physics to facilitate this. It extends the discussion of energy to include interatomic potentials and chemical reactions, the discussion of thermodynamics to include enthalpy and Gibbs free energy, and includes a serious discussion of random vs. coherent motion including diffusion. The development of instructional materials is coordinated with careful education research. Both the new content and the results of the research are described in a series of papers for which this paper serves as an overview and context.Comment: 12 page

Integrating Western and non-Western cultural expressions to further cultural and creative tourism: a case study

The term cultural industries was coined more than half a century ago, but at the beginning of the twenty-first century, the broader concept of creative industries, covering a wide range of cultural, design and digital activity, captured the imagination of public policymakers at national and city levels. Paralleling these developments has been the recognition of the phenomenon of cultural tourism and, more recently, the emergence of the idea of creative tourism, that is, tourism programmes designed to engage tourists actively in cultural activity. This paper presents a case study of a creative tourism event which took place in 2012 in the City of Manchester in the UK. The festival, which celebrated West African culture, utilised existing cultural institutions of the city and drew on the talents of local and visiting members of West African community to engage not only tourists but also indigenous and Black and Minority Ethnic (BME) residents of Manchester in a variety of cultural activities. It thus used the focus of creative tourism to seek to foster community and cultural development as well as tourism

Pylons in the back yard: local planning and perceived risks to health

Health fears arising from the presence of high-voltage power lines in residential areas have received recent attention in spatial planning. A study of stances taken by planning authorities in England and Wales shows their willingness to give expression to the concerns of local communities through precautionary measures, and the difficulties encountered in the face of official statements and industry opposition. These attempts to embody local feeling in patterns of development are illustrative of the increasing prevalence of a sense of risk in contemporary society. The spatial patterns of risk are also revealed, which owe much to the presence and distribution of industrial infrastructure in the landscape and to the associated contested use of land.</p

Siting prisons, sighting communities: geographies of objection in a planning process

This paper reviews the planning process for a Scottish prison located near a former mining village. Analysing the letters of objection submitted by residents offers an opportunity to explore local views about prison and community and to relate these to the unique social and spatial history of the area. The planning process itself structured how residents were able to express themselves and defined what counted as a relevant objection. After deconstructing this process, the paper then restores and uses as a framework for analysis three geographies of objection stripped from local responses to the development proposal: the emotional, temporal, and spatial. Emotional expressions of objection added intensity and gave meaning to claims about the historical decline of the region and also conveyed a deep sense of the proposed building site as a lived space. Particular grounds of opposition—over fear of strangers, the fragility of a local orchid, and the pollution from mining—provide an opportunity to explore the complex nature of place meaning and community identity, ultimately leading to a conclusion that the meaning of place is always in flux. The paper argues that Simmel’s classic concept of the stranger, as the outsider who comes to stay, offers a useful analytic in understanding how the quality of proximal remoteness that prisons and other unwanted developments constitute participates in a constantly evolving sense of the local

Following the signs: applying urban regime analysis to a UK case study

As the debate continues regarding the applicability of urban regime analysis in a UK context, three aspects stand out as highly significant: the target for analysis, the mode of scrutiny, and the context of local governing arrangements with its implications for interdependence as an impetus for co-operation. This article will examine urban regime analysis and the move from government to governance in order to answer why and how the private, voluntary and public sectors might be inclined to collaborate in regimes. In addition, the regime analysis will provide the parameters for examination whilst the issue of governance will afford context for local governing arrangements. Although some issues require slight reframing to reflect the UK context, the article will follow a rigorous framework for examination utilizing the full weight of regime analysis as articulated by Stone such that it could not be accused of “concept stretching.” Far from it: Through the examination of an informal partnership, a coalition of actors from the public, private, and voluntary sectors that has been in existence for more than 13 years, the article focuses, specifically, on the long-term, less visible aspects of local governance. As such, it is able to demonstrate how economic and political change can have a tangible effect on the manifestation of interdependence as an impetus for co-operation, not only for this specific locale but also for other cities facing similar challenges

The challenge of enterprise/innovation: a case study of a modern university

In the prevailing economic and political climate for Higher Education a greater emphasis has been placed on diversifying the funding base. The present study was undertaken between 2012 and 2014 and addressed the implementation of an approach to the transformation of one academic school in a medium-sized modern university in Wales to a more engaged enterprise culture. A multimethod investigation included a bi-lingual (English and Welsh) online survey of academic staff and yielded a 71% response rate (n = 45). The findings informed a series of in-depth interviews (n = 24) with a representative sample of those involved in enterprise work (support staff, managers, senior managers), and those who were not. The results provided the platform for the ‘S4E model’ for effective engagement with enterprise: (1) Strategic significance for Enterprise, (2) Support for Enterprise, (3) Synergy for Enterprise, and (4) Success for Enterprise. The outcomes of the research and the recommendations from it have potential to inform practice in other academic schools within the university and, in a wider context, within other Schools of Education regionally, nationally and internationally. Its original empirical exploration of enterprise within education studies is a significant contribution to that body of knowledge

Hospital food service: a comparative analysis of systems and introducing the ‘Steamplicity’ concept

Background Patient meals are an integral part of treatment hence the provision and consumption of a balanced diet, essential to aid recovery. A number of food service systems are used to provide meals and the Steamplicity concept has recently been introduced. This seeks, through the application of a static, extended choice menu, revised patient ordering procedures, new cooking processes and individual patient food heated/cooked at ward level, to address some of the current hospital food service concerns. The aim of this small-scale study, therefore, was to compare a cook-chill food service operation against Steamplicity. Specifically, the goals were to measure food intake and wastage at ward level; ‘stakeholders’ (i.e. patients, staff, etc.) satisfaction with both systems; and patients’ acceptability of the food provided. Method The study used both quantitative (self-completed patient questionnaires, n = 52) and qualitative methods (semi-structured interviews, n = 16) with appropriate stakeholders including medical and food service staff, patients and their visitors. Results Patients preferred the Steamplicity system overall and in particular in terms of food choice, ordering, delivery and food quality. Wastage was considerably less with the Steamplicity system, although care must be taken to ensure that poor operating procedures do not negate this advantage. When the total weight of food consumed in the ward at each meal is divided by the number of main courses served, at lunch, the mean intake with the cook-chill system was 202 g whilst that for the Steamplicity system was 282 g and for the evening meal, 226 g compared with 310 g. Conclusions The results of this small study suggest that Steamplicity is more acceptable to patients and encourages the consumption of larger portions. Further evaluation of the Steamplicity system is warranted. The purpose of this study was to directly compare selected aspects (food wastage at ward level; satisfaction with systems and food provided) of a traditional cook-chill food service operation against ‘Steamplicity’. Results indicate that patients preferred the ‘Steamplicty’ system in all areas: food choice, ordering, delivery, food quality and overall. Wastage was considerably less with the ‘Steamplicity’ system; although care must be taken to ensure that poor operating procedures do not negate this advantage. When the total weight of food consumed in the ward at each meal is divided by the number of main courses served, results show that at lunch, mean intake with the cook-chill system was 202g whilst that for the ‘Steamplicity’ system was 282g and for the evening meal, 226g compared with 310g