30 research outputs found
Feature Neighbourhood Mutual Information for multi-modal image registration: An application to eye fundus imaging
© 2014 Elsevier Ltd. All rights reserved. Multi-modal image registration is becoming an increasingly powerful tool for medical diagnosis and treatment. The combination of different image modalities facilitates much greater understanding of the underlying condition, resulting in improved patient care. Mutual Information is a popular image similarity measure for performing multi-modal image registration. However, it is recognised that there are limitations with the technique that can compromise the accuracy of the registration, such as the lack of spatial information that is accounted for by the similarity measure. In this paper, we present a two-stage non-rigid registration process using a novel similarity measure, Feature Neighbourhood Mutual Information. The similarity measure efficiently incorporates both spatial and structural image properties that are not traditionally considered by MI. By incorporating such features, we find that this method is capable of achieving much greater registration accuracy when compared to existing methods, whilst also achieving efficient computational runtime. To demonstrate our method, we use a challenging medical image data set consisting of paired retinal fundus photographs and confocal scanning laser ophthalmoscope images. Accurate registration of these image pairs facilitates improved clinical diagnosis, and can be used for the early detection and prevention of glaucoma disease
Time consistent discounting
A possibly immortal agent tries to maximise its summed discounted rewards over time, where discounting is used to avoid infinite utilities and encourage the agent to value current rewards more than future ones. Some commonly used discount functions lead to time-inconsistent behavior where the agent changes its plan over time. These inconsistencies can lead to very poor behavior. We generalise the usual discounted utility model to one where the discount function changes with the age of the agent. We then give a simple characterisation of time-(in)consistent discount functions and show the existence of a rational policy for an agent that knows its discount function is time-inconsistent
Recommended from our members
U.S. Department of Energy worker health risk evaluation methodology for assessing risks associated with environmental restoration and waste management
This document describes a worker health risk evaluation methodology for assessing risks associated with Environmental Restoration (ER) and Waste Management (WM). The methodology is appropriate for estimating worker risks across the Department of Energy (DOE) Complex at both programmatic and site-specific levels. This document supports the worker health risk methodology used to perform the human health risk assessment portion of the DOE Programmatic Environmental Impact Statement (PEIS) although it has applications beyond the PEIS, such as installation-wide worker risk assessments, screening-level assessments, and site-specific assessments
Survey on whiteflies and their parasitoids in cassava mosaic pandemic areas of Tanzania using morphological and molecular techniques
Published online: 27 MAY 2014Bemisia tabaci (Gennadius) is the vector of cassava mosaic geminiviruses (CMGs) and cassava brown streak viruses (CBSVs) in Africa, which cause devastating yield losses. As a prerequisite to developing biological control methods and enhancing knowledge of the fauna of whitefly parasitoids in sub-Saharan Africa, endemic parasitoids were surveyed in the cassava-growing regions of Tanzania and analysed using both morphological and molecular methods. An attempt was made to corroborate the identification of the parasitoid species on the basis of consideration of their morphology and sequence analyses of three DNA fragments, namely partial cytochrome oxidase I (COI), the D2 expansion segment of the 28S rRNA and the internal transcribed spacer I (ITS1)
EV02: a Phase I trial to compare the safety and immunogenicity of HIV DNA-C prime-NYVAC-C boost to NYVAC-C alone.
The aim of this randomised controlled trial was to see if the addition of 4 mg/ml DNA-C priming given by the intramuscular route at weeks 0 and 4 to NYVAC-C at weeks 20 and 24, safely increased the proportion of participants with HIV-specific T-cell responses measured by the interferon (IFN)-gamma ELISpot assay at weeks 26 and/or 28 compared to NYVAC-C alone. Although 2 individuals discontinued after the first DNA-C due to adverse events (1 vaso-vagal; 1 transient, asymptomatic elevation in alanine transaminase), the vaccines were well tolerated. Three others failed to complete the regimen (1 changed her mind; 2 lost to follow-up). Of the 35 that completed the regimen 90% (18/20) in the DNA-C group had ELISpot responses compared to 33% (5/15) that received NYVAC-C alone (p=0.001). Responses were to envelope in the majority (21/23). Of the 9 individuals with responses to envelope and other peptides, 8 were in the DNA-C group. These promising results suggest that DNA-C was an effective priming agent, that merits further investigation