New technology for interactive CAL: The origami project

Origami is a three‐year EPSRC project that forms part of a general research programme on human‐computer interaction. The goal of this research is to investigate and implement new methods for human‐computer interaction, and to apply and evaluate their use. The research centres on the DigitalDesk, an ordinary desk augmented with a computer display using projection television and a video camera to monitor inputs. The DigitalDesk allows electronic and printed documents to be combined to give richer presentation and interaction possibilities than are possible with either separate medium. This paper examines the implications of such a system for CAL, and presents two prototype applications that demonstrate the possibilities

Active paper for active learning

Recent research into distance learning and the virtual campus has focused on the use of electronic documents and computer‐based demonstrations to replace or reinforce traditional learning material. We show how a computer‐augmented desk, the DigitalDesk, can provide the benefits of both paper and electronic documents using a natural interface based on real paper documents. Many electronic documents, particularly those created using the guidelines produced by the Text Encoding Initiative (TEI), include detailed semantic and linguistic information that can be used to good effect in learning material. We discuss potential uses of TEI texts, and describe one simple application that allows a student's book to become an active part of a grammar lesson when placed on the DigitalDesk. The book is integrated into an interactive point‐and‐click interface, and feedback is related to the currently visible pages of the boo

Linear and nonlinear waveguides induced by optical vortex solitons

We study, numerically and analytically, linear and nonlinear waveguides induced by optical vortex solitons in a Kerr medium. Both fundamental and first-order guided modes are analyzed, as well as the cases of effectively defocusing and focusing nonlinearity.Comment: 3 pages, 3 figures, changed conten

Genomic plasticity and rapid host switching can promote the evolution of generalism : a case study in the zoonotic pathogen Campylobacter

This work was supported by the Biotechnology and Biological Sciences Research Council (BBSRC) grant BB/I02464X/1, the Medical Research Council (MRC) grants MR/M501608/1 and MR/L015080/1, and the Wellcome Trust grant 088786/C/09/Z. GM was supported by a NISCHR Health Research Fellowship (HF-14–13).Peer reviewedPublisher PD

Minibix: Item banking with web services

The Minibix system was developed from an existing prototype item bank system in use for high-stakes testing at the University of Cambridge. The system has been developed over the last year with support from the JISC e- Learning Programme. This project has redeveloped the system based on version 2 of the IMS Question and Test Interoperability (QTI) specification and is publishing the resulting system under an open source license. In this paper, we propose a simple service model for describing the authoring, banking, test construction and delivery of assessment content. The item banking model is implemented by the Minibix system and will be demonstrated in conjunction with authoring, test construction and delivery systems developed by the sister projects: AQuRate (Kingston University) and AsDel (University of Southampton). These services, as part of a wider e-Framework, could enable tool integration on a scale suitable for interacting with large-scale item banks. Private banks are already used routinely in high-stakes summative assessment but open repositories of items for formative use are now becoming available. For example, the E3AN item bank for Electrical and Electronic Engineering or the item bank for the Physical Sciences recently announced by the HEA

The cross-scale role of reef fish behaviour in mediating space use and behavioural cascades on coral reefs

Interspecific interactions play a fundamental role in shaping ecological communities. Whilst the non-consumptive effects of predation on animal behaviour and interspecific interactions are widely studied, the role of aggressive interactions between competitors in behavioural cascades is largely unknown. Using coral reef fish as a model system, I address this significant knowledge gap and improve our understanding of how competitive interactions may drive behavioural cascades across multiple ecological levels and taxa. Firstly, I take a macroecological approach to demonstrate strong links between coral reef benthic state and herbivorous fish functional group co-occurrence and their functional group diversity. Secondly, I demonstrate that between-individual variation in aggressive behaviour by farming damselfish creates a competitive landscape of risk on coral reefs. Thirdly, I identify that competitive risk avoidance between reef fish drives behavioural cascades in other taxa, reducing cleaning rates and client diversity at Pederson’s cleaner shrimp Ancylomenes pedersoni stations. Finally, I demonstrate that intraspecific aggression between territorial farming damselfish can be predicted by familiarity and differences in body size. The results presented in this thesis improve our knowledge of both the driving mechanisms and ultimate consequences of competition to community dynamics and ecosystem function. Furthermore, by drawing links across ecological scales, from between-individual behavioural variation to the macroecology of co-occurrence patterns, my thesis highlights the multiple pathways through which co-occurrence and competition may drive behaviourally mediated cascades throughout ecosystems

Comparative performance of airyscan and structured illumination superresolution microscopy in the study of the surface texture and 3D shape of pollen

The visualization of taxonomically diagnostic features of individual pollen grains can be a challenge for many ecologically and phylogenetically important pollen types. The resolution of traditional optical microscopy is limited by the diffraction of light (250 nm), while high resolution tools such as electron microscopy are limited by laborious preparation and imaging workflows. Airyscan confocal superresolution and structured illumination superresolution (SR-SIM) microscopy are powerful new tools for the study of nanoscale pollen morphology and three-dimensional structure that can overcome these basic limitations. This study demonstrates their utility in capturing morphological details below the diffraction limit of light. Using three distinct pollen morphotypes (Croton hirtus, Dactylis glomerata, and Helianthus sp.) and contrast-enhancing fluorescent staining, we were able to assess the effectiveness of the Airyscan and SR-SIM. We further demonstrate that these new superresolution methods can be easily applied to the study of fossil pollen material

Randomness Concerns When Deploying Differential Privacy

The U.S. Census Bureau is using differential privacy (DP) to protect confidential respondent data collected for the 2020 Decennial Census of Population & Housing. The Census Bureau's DP system is implemented in the Disclosure Avoidance System (DAS) and requires a source of random numbers. We estimate that the 2020 Census will require roughly 90TB of random bytes to protect the person and household tables. Although there are critical differences between cryptography and DP, they have similar requirements for randomness. We review the history of random number generation on deterministic computers, including von Neumann's "middle-square" method, Mersenne Twister (MT19937) (previously the default NumPy random number generator, which we conclude is unacceptable for use in production privacy-preserving systems), and the Linux /dev/urandom device. We also review hardware random number generator schemes, including the use of so-called "Lava Lamps" and the Intel Secure Key RDRAND instruction. We finally present our plan for generating random bits in the Amazon Web Services (AWS) environment using AES-CTR-DRBG seeded by mixing bits from /dev/urandom and the Intel Secure Key RDSEED instruction, a compromise of our desire to rely on a trusted hardware implementation, the unease of our external reviewers in trusting a hardware-only implementation, and the need to generate so many random bits.Comment: 12 pages plus 2 pages bibliograph

Restaurant cooking trends and increased risk for Campylobacter infection

In the United Kingdom, outbreaks of Campylobacter infection are increasingly attributed to undercooked chicken livers, yet many recipes, including those of top chefs, advocate short cooking times and serving livers pink. During 2015, we studied preferences of chefs and the public in the United Kingdom and investigated the link between liver rareness and survival of Campylobacter. We used photographs to assess chefs’ ability to identify chicken livers meeting safe cooking guidelines. To investigate the microbiological safety of livers chefs preferred to serve, we modeled Campylobacter survival in infected chicken livers cooked to various temperatures. Most chefs correctly identified safely cooked livers but overestimated the public’s preference for rareness and thus preferred to serve them more rare. We estimated that 19%-52% of livers served commercially in the United Kingdom fail to reach 70°C and that predicted Campylobacter survival rates are 48%-98%. These findings indicate that cooking trends are linked to increasing Campylobacter infections