Giant Colloidal Diffusivity on Corrugated Optical Vortices

A single colloidal sphere circulating around a periodically modulated optical vortex trap can enter a dynamical state in which it intermittently alternates between freely running around the ring-like optical vortex and becoming trapped in local potential energy minima. Velocity fluctuations in this randomly switching state still are characterized by a linear Einstein-like diffusion law, but with an effective diffusion coefficient that is enhanced by more than two orders of magnitude.Comment: 4 pages, 4 figure

The use of non-human primates in research

The use of non-human primates in biomedical research is a contentious issue that raises serious ethical and practical concerns. In the European Union, where regulations on their use are very tight, the number of non-human primates used in research has been in decline over the past decade. However, this decline has been paralleled by an increase in numbers used elsewhere in the world, with less regard for some of the ethical issues (e.g. genetic manipulations). There is evidence that researchers from high-income countries (HICs), where regulations on the use of non-human primates are strict, may be tempted to conduct some of their experiments in countries where regulation is less strict, through new collaborative efforts. In collaborative ventures, equivalence in the application of ethical standards in animal research, regardless of location, is necessary to avoid this exploitatio

How the Proximal Pocket May Influence the Enantiospecificities of Chloroperoxidase-Catalyzed Epoxidations of Olefins

Chloroperoxidase-catalyzed enantiospecific epoxidations of olefins are of significant biotechnological interest. Typical enantiomeric excesses are in the range of 66%–97% and translate into free energy differences on the order of 1 kcal/mol. These differences are generally attributed to the effect of the distal pocket. In this paper, we show that the influence of the proximal pocket on the electron transfer mechanism in the rate-limiting event may be just as significant for a quantitatively accurate account of the experimentally-measured enantiospecificities

Sustained moderate reductions in arterial CO2 after brain trauma Time-course of cerebral blood flow velocity and intracranial pressure

Objective: In healthy volunteers cerebral blood flow starts to recover towards baseline within a few minutes of continued hyperventilation due to normalisation of perivascular pH. We investigated the time-course of changes in middle cerebral artery mean flow velocity (FVm) and intracranial pressure (ICP) in head-injured patients during sustained moderate reductions in arterial partial pressure of CO2 (PaCO2). Design: Observational study. Patients: Twenty-seven sedated, mechanically ventilated patients with severe head injury. Interventions: Measurements were made during and after routine determination of CO2-reactivity: an acute 20% increase in respiratory minute volume was followed by a 10-min stabilisation period and 50min of continued moderate hyperventilation at a constant PaCO2 (>3.5kPa). Measurements and results: FVm was monitored with transcranial Doppler, ICP was monitored with intraparenchymal probes. During the 50-min period with stable PaCO2 FVm increased in 36% of patients. All other patients showed a decline in FVm over the same time period. Overall FVm recovery was −0.03±0.14%·min-1. The time-course of ICP changes was significantly different from that of FVm, with ICP reaching its lowest value earlier than FVm (23±12 vs 37±20min; P = 0.001) and returning more rapidly towards baseline than FVm (0.23±0.23 vs −0.03±0.14%·min-1; P< 0.0001). Conclusions: Head-injured patients may adapt differently to hyperventilation than healthy volunteers. Potentially harmful reductions in cerebral blood flow may persist beyond the duration of useful ICP reductio

Use of T2-weighted magnetic resonance imaging of the optic nerve sheath to detect raised intracranial pressure.

INTRODUCTION: The dural sheath surrounding the optic nerve communicates with the subarachnoid space, and distends when intracranial pressure is elevated. Magnetic resonance imaging (MRI) is often performed in patients at risk for raised intracranial pressure (ICP) and can be used to measure precisely the diameter of optic nerve and its sheath. The objective of this study was to assess the relationship between optic nerve sheath diameter (ONSD), as measured using MRI, and ICP. METHODS: We conducted a retrospective blinded analysis of brain MRI images in a prospective cohort of 38 patients requiring ICP monitoring after severe traumatic brain injury (TBI), and in 36 healthy volunteers. ONSD was measured on T2-weighted turbo spin-echo fat-suppressed sequence obtained at 3 Tesla MRI. ICP was measured invasively during the MRI scan via a parenchymal sensor in the TBI patients. RESULTS: Measurement of ONSD was possible in 95% of cases. The ONSD was significantly greater in TBI patients with raised ICP (>20 mmHg; 6.31 +/- 0.50 mm, 19 measures) than in those with ICP of 20 mmHg or less (5.29 +/- 0.48 mm, 26 measures; P < 0.0001) or in healthy volunteers (5.08 +/- 0.52 mm; P < 0.0001). There was a significant relationship between ONSD and ICP (r = 0.71, P < 0.0001). Enlarged ONSD was a robust predictor of raised ICP (area under the receiver operating characteristic curve = 0.94), with a best cut-off of 5.82 mm, corresponding to a negative predictive value of 92%, and to a value of 100% when ONSD was less than 5.30 mm. CONCLUSIONS: When brain MRI is indicated, ONSD measurement on images obtained using routine sequences can provide a quantitative estimate of the likelihood of significant intracranial hypertension

Identification of hip fracture patients from radiographs using Fourier analysis of the trabecular structure: a cross-sectional study

Peer reviewedPublisher PD

The AXES submissions at TrecVid 2013

The AXES project participated in the interactive instance search task (INS), the semantic indexing task (SIN) the multimedia event recounting task (MER), and the multimedia event detection task (MED) for TRECVid 2013. Our interactive INS focused this year on using classifiers trained at query time with positive examples collected from external search engines. Participants in our INS experiments were carried out by students and researchers at Dublin City University. Our best INS runs performed on par with the top ranked INS runs in terms of P@10 and P@30, and around the median in terms of mAP. For SIN, MED and MER, we use systems based on state- of-the-art local low-level descriptors for motion, image, and sound, as well as high-level features to capture speech and text and the visual and audio stream respectively. The low-level descriptors were aggregated by means of Fisher vectors into high- dimensional video-level signatures, the high-level features are aggregated into bag-of-word histograms. Using these features we train linear classifiers, and use early and late-fusion to combine the different features. Our MED system achieved the best score of all submitted runs in the main track, as well as in the ad-hoc track. This paper describes in detail our INS, MER, and MED systems and the results and findings of our experimen

App Law Within:Rights and Regulation in the Smartphone Age

This article assesses the regulation of smartphone ‘app stores’. At the outset, the significance of smartphones and apps to the debate on Internet regulation is considered, and places in the context of the adoption of smartphones and apps. The importance (commercially and as a study in governance and control) of the iOS App Store (Apple) is highlighted, as is the need to explore forms of regulation that are not linked with a violation of competition law. Section ‘Developer-focused issues’ deals with the relationship between Apple and app developers; three themes of Apple’s Guidelines are identified (content, development and payments), and the ways in which control can be challenged (through jailbreaking, ‘web apps’ and regulatory intervention) are scrutinized. Section ‘Citizen- and consumer-focused issues’ considers three ways in which apps are already regulated by law. The focus is on the protection of consumers (particularly through the UK system for ‘premium rate services’), but a discussion of user privacy and the regulation of video games and video-on-demand services in Europe is also included. Finally, in the section ‘Conclusion’, the tension between comparatively ‘open’ and ‘closed’ app stores is highlighted; the problems of applying general provisions to emerging formats are emphasized. It is concluded that the emerging status of non-carrier app stores as neither retailer nor platform means that it is not yet possible to identify the form of regulation that is in operation, but that some steps are available to legislators that could shift the balance between closed and open model

The ethics of ‘Trials within Cohorts’ (TwiCs): 2nd international symposium - London, UK. 7-8 November 2016

On 7-8 th November 2016, 60 people with an interest in the ‘ Trials within Cohorts ’ (TwiCs) approach for randomised controlled trial design met in London. The purpose of this 2 nd TwiCs international symposium was to share perspectives and experiences on ethical aspects of the TwiCs design, discuss how TwiCs relate to the current ethical frame- work, provide a forum in which to discuss and debate ethical issues and identify future directions for conceptual and empirical research. The symposium was supported by the Wellcome Trust and the NIHR CLAHRC Yorkshire and Humber and organised by members of the TwiCs network led by Clare Relton and attended by people from the UK, the Netherlands, Norway, Canada and USA. The two-day sympo- sium enabled an international group to meet and share experiences of the TwiCs design (also known as the ‘ cohort multiple RCT design ’ ), and to discuss plans for future research. Over the two days, invited plenary talks were interspersed by discussions, posters and mini pre- sentations from bioethicists, triallists and health research regulators. Key findings of the symposium were: (1) It is possible to make a compelling case to ethics committees that TwiCs designs are ap- propriate and ethical; (2) The importance of wider considerations around the ethics of inefficient trial designs; and (3) some questions about the ethical requirements for content and timing of informed consent for a study using the TwiCs design need to be decided on a case-by-case basis

Overview of data-synthesis in systematic reviews of studies on outcome prediction models

Background: Many prognostic models have been developed. Different types of models, i.e. prognostic factor and outcome prediction studies, serve different purposes, which should be reflected in how the results are summarized in reviews. Therefore we set out to investigate how authors of reviews synthesize and report the results of primary outcome prediction studies. Methods: Outcome prediction reviews published in MEDLINE between October 2005 and March 2011 were eligible and 127 Systematic reviews with the aim to summarize outcome prediction studies written in English were identified for inclusion. Characteristics of the reviews and the primary studies that were included were independently assessed by 2 review authors, using standardized forms. Results: After consensus meetings a total of 50 systematic reviews that met the inclusion criteria were included. The type of primary studies included (prognostic factor or outcome prediction) was unclear in two-thirds of the reviews. A minority of the reviews reported univariable or multivariable point estimates and measures of dispersion from the primary studies. Moreover, the variables considered for outcome prediction model development were often not reported, or were unclear. In most reviews there was no information about model performance. Quantitative analysis was performed in 10 reviews, and 49 reviews assessed the primary studies qualitatively. In both analyses types a range of different methods was used to present the results of the outcome prediction studies. Conclusions: Different methods are applied to synthesize primary study results but quantitative analysis is rarely performed. The description of its objectives and of the primary studies is suboptimal and performance parameters of the outcome prediction models are rarely mentioned. The poor reporting and the wide variety of data synthesis strategies are prone to influence the conclusions of outcome prediction reviews. Therefore, there is much room for improvement in reviews of outcome prediction studies. (aut.ref.