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A computational model of Lakatos-style reasoning
No full textLakatos outlined a theory of mathematical discovery and justification, which suggests ways in which concepts, conjectures and proofs gradually evolve via interaction between mathematicians. Different mathematicians may have different interpretations of a conjecture, examples or counterexamples of it, and beliefs regarding its value or theoremhood. Through discussion, concepts are refined and conjectures and proofs modified. We hypothesise that (i) it is possible to computationally represent Lakatos’s theory, and (ii) it is useful to do so. In order to test our hypotheses we have developed a computational model of his theory.Our model is a multiagent dialogue system. Each agent has a copy of a pre-existing theory formation system, which can form concepts and make conjectures which empirically hold for the objects of interest supplied. Distributing the objects of interest between agents means that they form different theories, which they communicate to each other. Agents then find counterexamples and use methods identified by Lakatos to suggest modifications to conjectures, concept definitions and proofs.Our main aim is to provide a computational reading of Lakatos’s theory, by interpreting it as a series of algorithms and implementing these algorithms as a computer program.This is the first systematic automated realisation of Lakatos’s theory. We contribute to the computational philosophy of science by interpreting, clarifying and extending his theory. We also contribute by evaluating his theory, using our model to test hypotheses about it, and evaluating our extended computational theory on the basis of criteria proposed by several theorists. A further contribution is to automated theory formation and automated theorem proving. The process of refining conjectures, proofs and concept definitions requires a flexibility which is inherently useful in fields which handle ill-specified problems, such as theory formation. Similarly, the ability to automatically modify an open conjecture into one which can be proved, is a valuable contribution to automated theorem proving.<br/
Segmenting multiple objects with overlapping appearance and uncertainty
No full textA probabilistic method is proposed for segmentation of multiple objects that overlap or are in close proximity to one another. A likelihood function is formulated that explicitly models overlapping object appearance. Priors on global appearance and geometry (including shape) are learned from example images. Markov chain Monte Carlo methods are used to obtain samples from a posterior distribution over model parameters from which expectations can be estimated. The method is described in detail for the problem of segmenting femur and tibia in x-ray images. The result is a probabilistic segmentation that quantifies uncertainty so that measurements such as joint space can be made with associated uncertainty
ART ± EDUCATION:the paradox of the ventriloquist’s soliloquy
Get PDFWhen we speak of art education are we trying to make sense of something by means of something else, just as a ventriloquist speaks with the mouth of a puppet to make us believe that he is having a dialogue with someone else,when in effect he is speaking to himself? This paper discusses how art education could only flourish as an act of approximation as it rejects the incremental and constructivist assumptions that have turned art and education into transactional instruments. Discussing art and education’s immanent relationship, this paper argues that art education is only necessary by force of the accidents that characterise it. Four scenarios, here identified in what the author calls the paradox of the ventriloquist’s soliloquy in art education,illustrate this argument. In discussing how this comes about, this paper makes reference to HernerSaeverot’s concept of indirect pedagogy and Charles Garoian’s prosthetic pedagogy
FutureEverything: ArtsAPI:Research & Development Report
No full textArtsAPI was a research and development project on how to better understand and evidence the connectivity and connections that arts organisations generate between things, people and events. The outcome is a proof of concept business modelling and analytic tool to enable arts organisations to generate new insight from data.ArtsAPI was led by 3 partners:FutureEverything, is an art and innovation organisation that conceived and led the project; Swirrl, is a leading linked open data (LOD) developer with a long track record of partnership with FutureEverything; and University of Dundee, is a leading research university with a strong academic team who offered expertise in analysing networks of people, organisations and things.A wider group of arts partners were collaborators in the project. These were: Blast Theory Red Eye Culture 24 Forma Warwick Arts Contact Theatre Islington Mill BalticWhat is it?ArtsAPI is a web application and an ambitious and experimental research and development project.The ArtsAPI web application is designed to enable arts organisations to show the value and impact generated through their networks. We believe that many arts organisations generate significant value through the relationships they create and sustain, but far too often this is not articulated or evidenced sufficiently to leverage insight, support and opportunities. ArtsAPI uses data to give organisations new insight into their relationships both internally and externally. This insight can be usedfor business planning, marketing, programming and as a way of demonstrating your impact.The tool uses email data gathered from team members to generate the following: A visualisation of your network both on an individual and organisational level A list of all the organisations and individuals you are connected to both on an individual and organisational level A clustering tool which will allow you to analyse how well connected you are to different sectors (some manual input is required) A clustering tool which will allow you to analyse how well connected you are to different cities and countries (some manual input is required) It gives you insight into Keywords that you use in email exchanges. These keywords can indicate the types of activities of individuals in your network It gives you insight into the Social Network Analysis measure of ‘out degrees’ – a measure which demonstrates whom within the network is distributing information It gives you insight into the Social Network Analysis measure of ‘in degrees’ – a measure which demonstrates whom within a network is receiving information from other nodes It gives you insight into the Social Network Analysis measure of ‘Degree Centrality’ – a measure which demonstrates which nodes are central to a network in terms of control over information flow It gives you insight into the Social Network Analysis measure of ‘Density’ – a measure that gives some insight into the speed of information handling within the networkOutcomesThe main outcome of this ambitious and exploratory project is a proof of concept web application. This has been trialled and showcased through a roadshow, and the project themes have been communicated through an art commission. The ambitious and experimental research and development process has generated new findings, and also revealed significant challenges that further development will need to address
The Local Projected Finite Element Method for Maxwell Problem
No full textAn element-local L2-projected C0 finite element method is presented to approximate the nonsmooth solution being not in H1 of the Maxwell problem on a nonconvex Lipschitz polyhedron with reentrant corners and edges. The key idea lies in that element-local L2 projectors are applied to both curl and div operators. The C0 linear finite element (enriched with certain higher degree bubble functions) is employed to approximate the nonsmooth solution. The coercivity in L2 norm is established uniform in the mesh-size, and the condition number O(h-2) of the resulting linear system is proven. For the solution and its curl in Hr with r < 1 we obtain an error bound O(hr) in an energy norm. Numerical experiments confirm the theoretical error bound
Mechanistic Insights Into the Therapeutic Use of High-Dose Allopurinol in Angina Pectoris
No full textObjectives The aim of this study was to evaluate the effect of high-dose allopurinol on vascular oxidative stress (OS) and endothelial function in subjects with stable coronary artery disease (CAD).Background Allopurinol, a xanthine oxidase inhibitor, prolongs the time to chest pain during exercise in angina. We sought to ascertain whether allopurinol also improves endothelial dysfunction in optimally treated CAD patients, because such an effect might be of value to reduce future cardiovascular mortality. The mechanism of the anti-ischemic effect of allopurinol could be related to its reducing xanthine oxidase-induced OS, and our second aim was to see whether allopurinol really does reduce vascular tissue OS in CAD patients.Methods A randomized, double-blind, placebo-controlled, crossover study was conducted in 80 patients with CAD, comparing allopurinol (600 mg/day) with placebo. Endothelial function was assessed by forearm venous occlusion plethysmography, flow-mediated dilation, and pulse wave analysis. Vascular OS was assessed by intra-arterial co-infusion of vitamin C and acetylcholine.Results Compared with placebo, allopurinol significantly improved endothelium-dependent vasodilation, by both forearm venous occlusion plethysmography (93 +/- 67% vs. 145 +/- 106%, p = 0.006) and flow-mediated dilation (4.2 +/- 1.8% vs. 5.4 +/- 1.7%, p < 0.001). Vascular oxidative stress was completely abolished by allopurinol. Central augmentation index improved significantly with allopurinol (2.6 +/- 7.0%, p < 0.001) but not with placebo.Conclusions Our study demonstrates that, in optimally treated CAD patients, high-dose allopurinol profoundly reduces vascular tissue OS and improves 3 different measures of vascular/endothelial dysfunction. The former effect on OS might underpin the anti-ischemic effect of allopurinol in CAD. Both effects (on OS and endothelial dysfunction) increase the likelihood that high-dose allopurinol might reduce future cardiovascular mortality in CAD, over and above existing optimum therapy. (Exploring the therapeutic potential of xanthine oxidase inhibitor allopurinol in angina; ISRCTN15253766) (J Am Coll Cardiol 2011;58:820-8) (C) 2011 by the American College of Cardiology Foundation</p
APEX1 regulation of aldosterone synthase gene transcription is disrupted by a common polymorphism in humans
No full textRATIONALE: The genetic mechanisms underlying hypertension are unclear, but relative aldosterone excess, present in ˜10% of hypertensive patients, is known to be a heritable trait. This phenotype associates with a T/C single nucleotide polymorphism (SNP) at position -344 of the aldosterone synthase gene (CYP11B2). However, deletion of this SNP has no effect on gene transcription. We have identified another T/C SNP at -1651, in tight linkage disequilibrium with the -344 SNP and here investigate its functional effect on CYP11B2 transcription. OBJECTIVE: We assessed the effect on transcriptional activity of the -1651 T/C SNP in vivo and in vitro and propose the mechanism by which transcriptional activity is altered. METHODS AND RESULTS: We demonstrated that the SNP at -1651 exerts significant allele-dependent effects on CYP11B2 transcription. We confirm binding of the transcriptional repressor APEX1 to -1651T, which is associated with reduced transcriptional activity in relation to the less strongly bound -1651C. We show that inhibiting APEX1 by small molecule inhibition or small interfering RNA (SiRNA) leads to increased CYP11B2 transcription. In addition, overexpression of APEX1 is associated with reduced transcriptional activity. Finally, we also show that -1651T associates with lower excretion rates of aldosterone metabolites in human subjects. CONCLUSIONS: We conclude that APEX1 is a novel transcriptional repressor of CYP11B2 and that differential APEX1 binding at -1651 of CYP11B2 results in altered gene expression. This mechanism may contribute to the observed relationship between CYP11B2 genotype and aldosterone phenotype in a subgroup of hypertensive patients
The Big Brother House is watching you
No full textThe transitory celebrities who compete in Big Brother occupy the arena of their competition agog and open mouthed, for while Big Brother is, apparently, about the contestants, the real star of the reality show is the House in which it takes place. The Big Brother House is a place of mirrors concealing hidden eyes, disembodied voices and multiple voyeurs. Rather than granted refuge in this house, its occupants are exposed in a crazy cottage where Orwell meets vaudeville; and prison cells or luxuriant dens appear overnight installed by mischievous pixies. The BB House is the antithesis of Bachelard’s vertically ordered Oneiric Axis of nightmarish cellar, formal, domestic ‘middle kingdom’, and the dream space of the attic. The Big Brother house is horizontally layered but fabricated, (to build and to lie). The Big Brother House is a model in extremis of what contemporary domestic interior has become. Like a Foucaulvian heterotopia it is an hermetic, apparently complete model of occupancy. Indeed there is no exterior to this house, which is both closed-off and opened-up through live digital streaming, RSS feeds, and text updates. As such the BB House reveals surrealist tendencies: the mirrors are evocative of Magritte; the windows are for the voyeur not external vista; the BB occupants and the TV viewers are passive idle loafers. In this respect, the Big Brother House reflects the spectacular model homes that have adorned expos from the Great to the Ideal Home exhibitions, from Peter and Alison Smithson’s House of the Future (1956) to Archigram’s 1990 Automated House (1967). Like these other models, the BB House is not a ‘real’ home, but is as abstracted as a white card maquette. But the Big Brother House possesses something that these other simulations lack: occupants who are at the same time real and imagined: The Big Brother House is not a fantasy, but an experiment, as empirically valid as any the most Orwellian of rational modernists could desire. Because the design of the house (and the show itself) is iterative and repeated, learning with each iteration from the experiences of the last, it is a continuing experiment in the negotiation between occupancy and constructed space of the most radical kind. This paper explores the emergence and the development of the many Big Brother Houses of the last decade, and the ways in which they have been occupied, in order to discuss issues that affect more general perceptions of the contemporary interior
Effects of atorvastatin added to inhaled corticosteroids on lung function and sputum cell counts in atopic asthma
No full textStatins have anti-inflammatory properties that may be beneficial in the treatment of asthma. A study was undertaken to test the hypothesis that atorvastatin added to inhaled corticosteroids improves lung function and airway inflammation in atopic adults with asthma
The emotional wellbeing of researchers:considerations for practice
No full textAs technology progressively pervades all aspects of our lives, members of the HCI community are engaging with increasingly sensitive contexts in their research - for example, end of life, genocide, computer-mediated communication under oppressive regimes. The considerations generated by research in such contexts can go well beyond those addressed by generic ethical approval processes and institutional practice. Whilst it is standard to ensure that the wellbeing of participants is taken into account in research design and the ethical approval process, it is much less common for the researcher's own emotional wellbeing to be considered explicitly. This paper describes the role that a researcher's emotions may play in research, and the impact which research in sensitive contexts can have on researchers' emotional wellbeing and on research validity. A qualitative survey is described which investigated the support mechanisms which HCI researchers have in place in case they are distressed/ troubled as a result of their research. The results of the survey are used, in combination with insights into how other disciplines address the topic, to synthesize suggestions for ways in which the HCI community can proactively incorporate consideration for the emotional wellbeing of the researcher into the research process
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