441 research outputs found

    Strokes for Representing Univariate Vector Field Maps

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    Particle systems make an excellent tool for creating tracks (which we call strokes) in vector fields. The question addressed in this paper is how such tracks should be made to vary in size and colour in order to reveal properties such as local direction and strength of the field. We find that for strokes that vary from large to small, direction is indicated by the large end. We also find that for strokes that vary in colour, the colour of the background is the most important determinant of perceived direction

    CONTRACT BUILDER ETHEREUM APPLICATION

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    Developments in Blockchain, smart contract, and decentralized application (“dApps”) technology have enabled new types of software that can improve efficiency within law firms by increasing speed at which attorneys may draft and execute contracts. Smart contracts and dApps are self-executing software that reside on a blockchain. Custom smart contracts can be built in a modular manner in order to emulate contracts that are commonly generated and executed in law firms. Such contracts include those for the transfer of services, goods, and title. This article explores exactly how implementations of smart contracts for law firms may look

    On a generalized quantum SWAP gate

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    The SWAP gate plays a central role in network designs for qubit quantum computation. However, there has been a view to generalize qubit quantum computing to higher dimensional quantum systems. In this paper we construct a generalized SWAP gate using only instances of the generalized controlled-NOT gate to cyclically permute the states of d qudits for d prime

    Effect of light filters on reading speed in normal and low vision due to age-related macular degeneration

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    Purpose: To investigate the effects of light filters on reading speed in normal and low vision due to age-related macular degeneration (AMD). Methods: Reading speed was determined for 12 subjects with normal vision and 12 subjects with non-exudative AMD using stationary lowercase nonsensical print in Times Roman font and four light filters; a yellow Corning Photochromic Filter (CPF) 450, a grey neural density (ND) filter, an individual filter obtained using the Intuitive ColorimeterŸ and a clear filter. Results: There was no statistically significant light filter effect on reading speed for the normal subjects. The AMD group demonstrated a statistically significant 5% average improvement in reading speed with the CPF450 compared with the other filters although some AMD subjects had improvements of 10-15%. Conclusions: Light filters obtained using the Intuitive ColorimeterŸ performed poorly when compared with the CPF450, ND and clear filters for both the study groups. For the AMD group, average reading speed was statistically greater with the CPF450 than the other filters, however it is questionable whether the improvement (5%) would be clinically significant. As some of the subjects with AMD had greater improvements with the CPF450 we advocate clinical assessment of light filters using existing protocols on an individual basis. © 2004 The College of Optometrists

    Dating the Morris House: A Study of Heritage Value in Nova Scotia

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    In 2009, a group of concerned citizens in Halifax rallied to the banner of The Heritage Trust of Nova Scotia and the Ecology Action Centre to save an 18th century building from demolition. Their case for preserving the building hinged on its unique heritage value, it having formerly housed the office of Charles Morris,Nova Scotia’s first Chief Surveyor. Thanks to their efforts, the Morris House was temporarily relocated to a nearby vacant lot while a new apartment building gradually rose in its place. Although researchers had believed the Morris House pre-dated 1781, the year of Charles Morris’s death, its precise age was unknown at the time of the move. Through a combination of dendroarchaeological, cartographic, and documentary evidence, our research significantly alters previous understandings of the building’s history and complicates the narrative advanced by heritage advocates in its defense. In doing so, it also raises questions about the interface between empirical research and the socio-political factors influencing the determination of heritage value. En 2009, un groupe de citoyen s’est rĂ©uni sous les auspices de The Heritage Trust of Nova Scotia et The Ecology Action Centre concernĂ© par la sauvegarde d’un bĂątiment du 18e siĂšcle menacĂ© de dĂ©molition. Connu sous le nom de Morris Building en raison de liens possibles avec Charles Morris (pĂšre), premier chef arpenteur gĂ©omĂštre de la Nouvelle-Écosse, le bĂątiment a Ă©tĂ© dĂ©placĂ© de sa position initiale du 1273 de la rue Hollis de Halifax Ă  un site temporaire Ă  proximitĂ©, car un bloc appartement devait y ĂȘtre construit. Bien que les spĂ©cialistes croyaient que le Morris Building datait d’avant 1781, son Ăąge exact restait inconnu. Avec la combinaison de recherches dendroarchĂ©ologiques, cartographiques et documentaires, notre Ă©tude modifie significativement la comprĂ©hension de l’histoire du bĂątiment et complique le tableau avancĂ© par les dĂ©fenseurs de la tradition dans la conservation de cet hĂ©ritage. Ce faisant, la question est posĂ©e sur les chevauchements et relations entre la recherche empirique et les facteurs socio-politiques qui influencent la dĂ©termination de la valeur historique d’un site

    Do tinted lenses or filters improve visual performance in low vision? A review of the literature

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    This is a review of studies that have investigated the proposed rehabilitative benefit of tinted lenses and filters for people with low vision. Currently, eye care practitioners have to rely on marketing literature and anecdotal reports from users when making recommendations for tinted lens or filter use in low vision. Our main aim was to locate a prescribing protocol that was scientifically based and could assist low vision specialists with tinted lens prescribing decisions. We also wanted to determine if previous work had found any tinted lens/task or tinted lens/ocular condition relationships, i.e. were certain tints or filters of use for specific tasks or for specific eye conditions. Another aim was to provide a review of previous research in order to stimulate new work using modern experimental designs. Past studies of tinted lenses and low vision have assessed effects on visual acuity (VA), grating acuity, contrast sensitivity (CS), visual field, adaptation time, glare, photophobia and TV viewing. Objective and subjective outcome measures have been used. However, very little objective evidence has been provided to support anecdotal reports of improvements in visual performance. Many studies are flawed in that they lack controls for investigator bias, and placebo, learning and fatigue effects. Therefore, the use of tinted lenses in low vision remains controversial and eye care practitioners will have to continue to rely on anecdotal evidence to assist them in their prescribing decisions. Suggestions for future research, avoiding some of these experimental shortcomings, are made. © 2002 The College of Optometrists

    On swapping the states of two qudits

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    The SWAP gate has become an integral feature of quantum circuit architectures and is designed to permute the states of two qubits through the use of the well-known controlled-NOT gate. We consider the question of whether a two-qudit quantum circuit composed entirely from instances of the generalised controlled-NOT gate can be constructed to permute the states of two qudits. Arguing via the signature of a permutation, we demonstrate the impossibility of such circuits for dimensions d≡3d \equiv 3 (mod 4)

    Systematic reviews of and integrated report on the quantitative, qualitative and economic evidence base for the management of obesity in men

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    <b>Background</b><p></p> Obesity increases the risk of many serious illnesses such as coronary heart disease, type 2 diabetes and osteoarthritis. More men than women are overweight or obese in the UK but men are less likely to perceive their weight as a problem and less likely to engage with weight-loss services.<p></p> <b>Objective</b><p></p> The aim of this study was to systematically review evidence-based management strategies for treating obesity in men and investigate how to engage men in obesity services by integrating the quantitative, qualitative and health economic evidence base.<p></p> <b>Data sources</b><p></p> Electronic databases including MEDLINE, EMBASE, PsycINFO, the Cochrane Central Register of Controlled Trials, the Database of Abstracts of Reviews of Effects and the NHS Economic Evaluation Database were searched from inception to January 2012, with a limited update search in July 2012. Subject-specific websites, reference lists and professional health-care and commercial organisations were also consulted.<p></p> <b>Review methods</b><p></p> Six systematic reviews were conducted to consider the clinical effectiveness, cost-effectiveness and qualitative evidence on interventions for treating obesity in men, and men in contrast to women, and the effectiveness of interventions to engage men in their weight reduction. Randomised controlled trials (RCTs) with follow-up data of at least 1 year, or any study design and length of follow-up for UK studies, were included. Qualitative and mixed-method studies linked to RCTs and non-randomised intervention studies, and UK-based, men-only qualitative studies not linked to interventions were included. One reviewer extracted data from the included studies and a second reviewer checked data for omissions or inaccuracies. Two reviewers carried out quality assessment. We undertook meta-analysis of quantitative data and a realist approach to integrating the qualitative and quantitative evidence synthesis.<p></p> <b>Results</b><p></p> From a total of 12,764 titles reviewed, 33 RCTs with 12 linked reports, 24 non-randomised reports, five economic evaluations with two linked reports, and 22 qualitative studies were included. Men were more likely than women to benefit if physical activity was part of a weight-loss programme. Reducing diets tended to produce more favourable weight loss than physical activity alone (mean weight change after 1 year from a reducing diet compared with an exercise programme -3.2 kg, 95% CI -4.8 kg to -1.6 kg). The type of reducing diet did not affect long-term weight loss. A reducing diet plus physical activity and behaviour change gave the most effective results. Low-fat reducing diets, some with meal replacements, combined with physical activity and behaviour change training gave the most effective long-term weight change in men [-5.2 kg (standard error 0.2 kg) after 4 years]. Such trials may prevent type 2 diabetes in men and improve erectile dysfunction. Although fewer men joined weight-loss programmes, once recruited they were less likely to drop out than women (difference 11%, 95% CI 8% to 14%). The perception of having a health problem (e.g. being defined as obese by a health professional), the impact of weight loss on health problems and desire to improve personal appearance without looking too thin were motivators for weight loss amongst men. The key components differ from those found for women, with men preferring more factual information on how to lose weight and more emphasis on physical activity programmes. Interventions delivered in social settings were preferred to those delivered in health-care settings. Group-based programmes showed benefits by facilitating support for men with similar health problems, and some individual tailoring of advice assisted weight loss in some studies. Generally, men preferred interventions that were individualised, fact-based and flexible, which used business-like language and which included simple to understand information. Preferences for men-only versus mixed-sex weight-loss group programmes were divided. In terms of context, programmes which were cited in a sporting context where participants have a strong sense of affiliation showed low drop out rates and high satisfaction. Although some men preferred weight-loss programmes delivered in an NHS context, the evidence comparing NHS and commercial programmes for men was unclear. The effect of family and friends on participants in weight-loss programmes was inconsistent in the evidence reviewed - benefits were shown in some cases, but the social role of food in maintaining relationships may also act as a barrier to weight loss. Evidence on the economics of managing obesity in men was limited and heterogeneous.<p></p> <b>Limitations</b><p></p> The main limitations were the limited quantity and quality of the evidence base and narrow outcome reporting, particularly for men from disadvantaged and minority groups. Few of the studies were undertaken in the UK.<p></p> <b>Conclusions</b><p></p> Weight reduction for men is best achieved and maintained with the combination of a reducing diet, physical activity advice or a physical activity programme, and behaviour change techniques. Tailoring interventions and settings for men may enhance effectiveness, though further research is needed to better understand the influence of context and content. Future studies should include cost-effectiveness analyses in the UK setting

    Discovery of a missense mutation (Q222K) of the APOE gene from the Australian imaging, biomarker and lifestyle study

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    After age, polymorphisms of the Apolipoprotein E (APOE) gene are the biggest risk factor for the development of Alzheimer\u27s disease (AD). During our investigation to discovery biomarkers in plasma, using 2D gel electrophoresis, we found an individual with and unusual apoE isoelectric point compared to APOE ϔ2, ϔ3, and ϔ4 carriers. Whole exome sequencing of APOE from the donor confirmed a single nucleotide polymorphism (SNP) in exon 4, translating to a rare Q222K missense mutation. The apoE ϔ4 (Q222K) mutation did not form dimers or complexes observed for apoE ϔ2 ϔ3 proteins
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