Learning Membership Functions in a Function-Based Object Recognition System

Functionality-based recognition systems recognize objects at the category level by reasoning about how well the objects support the expected function. Such systems naturally associate a ``measure of goodness'' or ``membership value'' with a recognized object. This measure of goodness is the result of combining individual measures, or membership values, from potentially many primitive evaluations of different properties of the object's shape. A membership function is used to compute the membership value when evaluating a primitive of a particular physical property of an object. In previous versions of a recognition system known as Gruff, the membership function for each of the primitive evaluations was hand-crafted by the system designer. In this paper, we provide a learning component for the Gruff system, called Omlet, that automatically learns membership functions given a set of example objects labeled with their desired category measure. The learning algorithm is generally applicable to any problem in which low-level membership values are combined through an and-or tree structure to give a final overall membership value.Comment: See http://www.jair.org/ for any accompanying file

Preliminary Abundance Analysis of Galactic Bulge Main Sequence, Subgiant, and Giant Branch Stars Observed During Microlensing with Keck/HIRES

We present an abundance analysis of six main sequence turnoff, subgiant, and giant branch stars toward the Galactic bulge that were observed with Keck/HIRES during microlensing events. This is an early look at the first detailed chemical analysis of main sequence stars in the Galactic bulge. Lensing events allow the effective aperture of Keck to be increased beyond its current dimensions; although, some events still stretched its spectroscopic capabilities. Future large telescopes with high resolution and high throughput spectrometers will allow the study of abundances in distant stellar populations and in less evolved stars with greater ease.Comment: 8 pages including 2 figures. To appear in SPIE proceedings on Astronomical Telescopes and Instrumentation. Uses spie.cl

Sponsorship of sport mega events: a conceptual approach for creating shared value

Sport mega events represent an important platform that sponsors can use to communicate with prospective consumers. Although literature exists on value creation within sport (e.g. Woratschek, Horbel, & Popp, 2014), little attention has been afforded as to how sponsor brands and hosts may create value for consumers and other stakeholder groups within this important context. Therefore, this study aims to conceptualise the Creation of Shared Value (CSV) in sport mega events

Negative-weight percolation

We describe a percolation problem on lattices (graphs, networks), with edge weights drawn from disorder distributions that allow for weights (or distances) of either sign, i.e. including negative weights. We are interested whether there are spanning paths or loops of total negative weight. This kind of percolation problem is fundamentally different from conventional percolation problems, e.g. it does not exhibit transitivity, hence no simple definition of clusters, and several spanning paths/loops might coexist in the percolation regime at the same time. Furthermore, to study this percolation problem numerically, one has to perform a non-trivial transformation of the original graph and apply sophisticated matching algorithms. Using this approach, we study the corresponding percolation transitions on large square, hexagonal and cubic lattices for two types of disorder distributions and determine the critical exponents. The results show that negative-weight percolation is in a different universality class compared to conventional bond/site percolation. On the other hand, negative-weight percolation seems to be related to the ferromagnet/spin-glass transition of random-bond Ising systems, at least in two dimensions.Comment: v1: 4 pages, 4 figures; v2: 10 pages, 7 figures, added results, text and reference

A questionnaire elicitation of surgeons' belief about learning within a surgical trial

PMID: 23145113 [PubMed - indexed for MEDLINE] PMCID: PMC3493499 Free PMC ArticlePeer reviewedPublisher PD

Exploring Zeptosecond Quantum Equilibration Dynamics: From Deep-Inelastic to Fusion-Fission Outcomes in 58^{58}Ni+60^{60}Ni Reactions

Energy dissipative processes play a key role in how quantum many-body systems dynamically evolve towards equilibrium. In closed quantum systems, such processes are attributed to the transfer of energy from collective motion to single-particle degrees of freedom; however, the quantum many-body dynamics of this evolutionary process are poorly understood. To explore energy dissipative phenomena and equilibration dynamics in one such system, an experimental investigation of deep-inelastic and fusion-fission outcomes in the $^{58}$Ni+$^{60}$Ni reaction has been carried out. Experimental outcomes have been compared to theoretical predictions using Time Dependent Hartree Fock and Time Dependent Random Phase Approximation approaches, which respectively incorporate one-body energy dissipation and fluctuations. Excellent quantitative agreement has been found between experiment and calculations, indicating that microscopic models incorporating one-body dissipation and fluctuations provide a potential tool for exploring dissipation in low-energy heavy ion collisions.Comment: 11 pages, 9 figures, 1 table, including Supplemental Material - Version accepted for publication in Physical Review Letter

LAG-3 Confers a Competitive Disadvantage upon Antiviral CD8 + T Cell Responses

Ongoing clinical trials are evaluating the benefits of systemic blockade of lymphocyte activation gene-3 (LAG-3) signals to improve immunity to tumors. Those studies are founded on the well-established inhibitory role of LAG-3 in regulating CD8+ T cells during chronic virus infection and anti-tumor responses. However, the T cell response in LAG-3 deficient mice is similar in size and function to that in wild type animals, suggesting LAG-3 has nuanced immune-regulatory functions. We performed a series of adoptive transfer experiments in mice to better understand the T cell-intrinsic functions of LAG-3 in the regulation of CD8+ T cell responses. Our results indicate that LAG-3 expression by CD8+ T cells inhibits their competitive fitness and results in a slightly reduced rate of cell division in comparison to LAG-3 deficient cells. This cell-intrinsic effect of LAG-3 was consistent across both acute and chronic virus infections. These data show that LAG-3 directly modulates the size of the T cell response and support the use of LAG-3 blockade regimens to enhance CD8+ T cell responses

Enhanced motivational interviewing for reducing weight and increasing physical activity in adults with high cardiovascular risk: the MOVE IT three-arm RCT.

BACKGROUND: Motivational interviewing (MI) enhanced with behaviour change techniques (BCTs) and deployed by health trainers targeting multiple risk factors for cardiovascular disease (CVD) may be more effective than interventions targeting a single risk factor. OBJECTIVES: The clinical effectiveness and cost-effectiveness of an enhanced lifestyle motivational interviewing intervention for patients at high risk of CVD in group settings versus individual settings and usual care (UC) in reducing weight and increasing physical activity (PA) were tested. DESIGN: This was a three-arm, single-blind, parallel randomised controlled trial. SETTING: A total of 135 general practices across all 12 South London Clinical Commissioning Groups were recruited. PARTICIPANTS: A total of 1742 participants aged 40-74 years with a ≥ 20.0% risk of a CVD event in the following 10 years were randomised. INTERVENTIONS: The intervention was designed to integrate MI and cognitive-behavioural therapy (CBT), delivered by trained healthy lifestyle facilitators in 10 sessions over 1 year, in group or individual format. The control group received UC. RANDOMISATION: Simple randomisation was used with computer-generated randomisation blocks. In each block, 10 participants were randomised to the group, individual or UC arm in a 4 : 3 : 3 ratio. Researchers were blind to the allocation. MAIN OUTCOME MEASURES: The primary outcomes are change in weight (kg) from baseline and change in PA (average number of steps per day over 1 week) from baseline at the 24-month follow-up, with an interim follow-up at 12 months. An economic evaluation estimates the relative cost-effectiveness of each intervention. Secondary outcomes include changes in low-density lipoprotein cholesterol and CVD risk score. RESULTS: The mean age of participants was 69.75 years (standard deviation 4.11 years), 85.5% were male and 89.4% were white. At the 24-month follow-up, the group and individual intervention arms were not more effective than UC in increasing PA [mean 70.05 steps, 95% confidence interval (CI) -288 to 147.9 steps, and mean 7.24 steps, 95% CI -224.01 to 238.5 steps, respectively] or in reducing weight (mean -0.03 kg, 95% CI -0.49 to 0.44 kg, and mean -0.42 kg, 95% CI -0.93 to 0.09 kg, respectively). At the 12-month follow-up, the group and individual intervention arms were not more effective than UC in increasing PA (mean 131.1 steps, 95% CI -85.28 to 347.48 steps, and mean 210.22 steps, 95% CI -19.46 to 439.91 steps, respectively), but there were reductions in weight for the group and individual intervention arms compared with UC (mean -0.52 kg, 95% CI -0.90 to -0.13 kg, and mean -0.55 kg, 95% CI -0.95 to -0.14 kg, respectively). The group intervention arm was not more effective than the individual intervention arm in improving outcomes at either follow-up point. The group and individual interventions were not cost-effective. CONCLUSIONS: Enhanced MI, in group or individual formats, targeted at members of the general population with high CVD risk is not effective in reducing weight or increasing PA compared with UC. Future work should focus on ensuring objective evidence of high competency in BCTs, identifying those with modifiable factors for CVD risk and improving engagement of patients and primary care. TRIAL REGISTRATION: Current Controlled Trials ISRCTN84864870. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 23, No. 69. See the NIHR Journals Library website for further project information. This research was part-funded by the NIHR Biomedical Research Centre at South London and Maudsley NHS Foundation Trust and King's College London