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Segmentation, Super-resolution and Fusion for Digital Mammogram Classification
No full textMammography is one of the most common and effective techniques used by radiologists for the early detection of breast cancer. Recently, computer-aided detection/diagnosis (CAD) has become a major research topic in medical imaging and has been widely applied in clinical situations. According to statics, early detection of cancer can reduce the mortality rates by 30% to 70%, therefore detection and diagnosis in the early stage are very important. CAD systems are designed primarily to assist radiologists in detecting and classifying abnormalities in medical scan images, but the main challenges hindering their wider deployment is the difficulty in achieving accuracy rates that help improve radiologists’ performance.
The detection and diagnosis of breast cancer face two main issues: the accuracy of the CAD system, and the radiologists’ performance in reading and diagnosing mammograms. This thesis focused on the accuracy of CAD systems. In particular, we investigated two main steps of CAD systems; pre-processing (enhancement and segmentation), feature extraction and classification. Through this investigation, we make five main contributions to the field of automatic mammogram analysis.
In automated mammogram analysis, image segmentation techniques are employed in breast boundary or region-of-interest (ROI) extraction. In most Medio-Lateral Oblique (MLO) views of mammograms, the pectoral muscle represents a predominant density region and it is important to detect and segment out this muscle region during pre-processing because it could be bias to the detection of breast cancer. An important reason for the breast border extraction is that it will limit the search-zone for abnormalities in the region of the breast without undue influence from the background of the mammogram. Therefore, we propose a new scheme for breast border extraction, artifact removal and removal of annotations, which are found in the background of mammograms. This was achieved using an local adaptive threshold that creates a binary mask for the images, followed by the use of morphological operations. Furthermore, an adaptive algorithm is proposed to detect and remove the pectoral muscle automatically.
Feature extraction is another important step of any image-based pattern classification system. The performance of the corresponding classification depends very much on how well the extracted features represent the object of interest. We investigated a range of different texture feature sets such as Local Binary Pattern Histogram (LBPH), Histogram of Oriented Gradients (HOG) descriptor, and Gray Level Co-occurrence Matrix (GLCM). We propose the use of multi-scale features based on wavelet and local binary patterns for mammogram classification. We extract histograms of LBP codes from the original image as well as the wavelet sub-bands. Extracted features are combined into a single feature set. Experimental results show that our proposed method of combining LBPH features obtained from the original image and with LBPH features obtained from the wavelet domain increase the classification accuracy (sensitivity and specificity) when compared with LBPH extracted from the original image.
The feature vector size could be large for some types of feature extraction schemes and they may contain redundant features that could have a negative effect on the performance of classification accuracy. Therefore, feature vector size reduction is needed to achieve higher accuracy as well as efficiency (processing and storage). We reduced the size of the features by applying principle component analysis (PCA) on the feature set and only chose a small number of eigen components to represent the features. Experimental results showed enhancement in the mammogram classification accuracy with a small set of features when compared with using original feature vector.
Then we investigated and propose the use of the feature and decision fusion in mammogram classification. In feature-level fusion, two or more extracted feature sets of the same mammogram are concatenated into a single larger fused feature vector to represent the mammogram. Whereas in decision-level fusion, the results of individual classifiers based on distinct features extracted from the same mammogram are combined into a single decision. In this case the final decision is made by majority voting among the results of individual classifiers.
Finally, we investigated the use of super resolution as a pre-processing step to enhance the mammograms prior to extracting features. From the preliminary experimental results we conclude that using enhanced mammograms have a positive effect on the performance of the system. Overall, our combination of proposals outperforms several existing schemes published in the literature
Impact of pharmacy care upon adherence to cardiovascular medicines: a feasibility pilot controlled trial
No full textObjective To investigate the feasibility and potential impact of a pharmacy care intervention, involving motivational interviews among patients with acute coronary syndrome, on adherence to medication and on health outcomes.
Methods This article reports a prospective, interventional, controlled feasibility/pilot study. Seventy one patients discharged from a London Heart Attack Centre following acute treatment for a coronary event were enrolled and followed up for 6 months. Thirty two pharmacies from six London boroughs were allocated into intervention or control sites. The intervention was delivered by community pharmacists face-to-face in the pharmacy, or by telephone. Consultations were delivered as part of the New Medicine Service or a Medication Usage Review. They involved a 15–20 min motivational interview aimed at improving protective cardiovascular medicine taking.
Results At 3 months, there was a statistically significant difference in adherence between the intervention group (M=7.7, SD=0.56) and the control group (M=7.0, SD=1.85), p=0.026. At 6 months, the equivalent figures were for the intervention group M=7.5, SD=1.47 and for the controls M=6.1, SD=2.09 (p=0.004). In addition, there was a statistically significant relationship between the level of adherence at 3 months and beliefs regarding medicines (p=0.028). Patients who reported better adherence expressed positive beliefs regarding the necessity of taking their medicines. However, given the small sample size, no statistically significant outcome difference in terms of recorded blood pressure and low density lipoprotein-cholesterol was observed over the 6 months of the study.
Conclusions The feasibility, acceptability and potentially positive clinical outcome of the intervention were demonstrated, long with a high level of patient acceptability. It had a significant impact on cardiovascular medicine taking adherence. But these findings must be interpreted with caution. The intervention should be tested in a larger trial to ascertain its full clinical utility
An analysis of the relationships between peer support and diabetes outcomes in adolescents with type 1 diabetes
No full textThis study explores the relationships between the various subtypes of global and diabetes-specific peer support and health outcomes in adolescents with type 1 diabetes. Global peer support significantly predicted self-care and glycated haemoglobin, although no associations were identified for diabetes-specific support overall, nor its factors. When comparing participants with above or below average glycaemic control, significantly greater diabetes-specific support was reported in those with poorer control. It is suggested that this may be related to feelings of nagging, in which diabetes-specific support is perceived as harassment
The architectural transformation of Northumberland House under the 7th Duke of Somerset and the 1st Duke and Duchess of Northumberland, 1748-86
No full textThis paper is based on the authors’ longstanding interest in Northumberland House and follows two previous papers by Manolo Guerci, which appeared in this journal in 2010 and 2014 respectively. The first paper explored the house as originally built by the 1st Earl of Northampton between 1605 and 1614, while the second looked at both the ownership of the Earls of Suffolk, in the years between Northampton’s death and 1642, and the transformations of the 10th Earl of Northumberland, from that year to 1668. The changes initiated by the 7th Duke and Duchess of Somerset in 1748, and completed by the 1st Duke and Duchess of Northumberland (third creation) in the 1750s and 1760s, finished the process of shifting the public side of the house from the Strand to the river side, begun by the 10th Earl of Northumberland. Never before fully investigated, this period is crucial in the long history of the house, as a large body of renowned craftsmen and builders (presented as supplementary material to the online edition of this paper) experimented with lavish interiors, which became a model for contemporary enterprises. In addition, Northumberland House acted as the showcase of the couple’s taste and patronage, as well as the venue for the private ‘Musaeum’ of the Duchess, within a larger remarkable collection, and probably functioned as a proto-academy for selected artists and connoisseurs
Recruiting brown adipose tissue in human obesity
No full textObesity remains a major biomedical challenge with the associated diseases, particularly insulin resistance and type 2 diabetes, imposing a substantial and increasing burden on healthcare systems. In the US, one-third of adults are classed as obese (BMI >30), while in the UK, which has one of the highest incidence rates in Europe, 25% are obese. Conceptually, the treatment of obesity is simple: energy expenditure must exceed energy intake. In the late 1970’s it was proposed, primarily from studies on rats and mice, that reduced expenditure on adaptive heat production (thermogenesis) associated with a specialised fat tissue – brown adipose tissue (BAT) – is central to the development of obesity. Correspondingly, for a period stimulation of heat production in BAT was seen as a potential therapeutic route for reversing obesity and there was a search for agents that would stimulate the activity of the tissue
PCR arrays indicate that the expression of extracellular matrix and cell adhesion genes in human adipocytes is regulated by IL-1β (interleukin-1β)
Get PDFThe role of IL-1β in regulating the expression of extracellular matrix (ECM) and cell adhesion genes in human adipocytes has been examined. Adipocytes differentiated in culture were incubated with IL-1β for 4 or 24 h and RNA probed with PCR arrays for 84 ECM and cell adhesion genes. Treatment with IL-1β resulted in changes in the expression at one or both time points of ~50% of the genes probed by the arrays, the majority being down-regulated. Genes whose expression was down-regulated by IL-1β included those encoding several collagen chains and integrin subunits. In contrast, IL-1β induced substantial increases (>10-fold) in the expression of ICAM1, VCAM1, MMP1 and MMP3; the secretion of the encoded proteins was also markedly stimulated. IL-1β has a pervasive effect on the expression of ECM and cell adhesion genes in human adipocytes, consistent with the derangement of tissue structure during inflammation in white fat
Classical Horsemanship and the Dangers of the Emergent Intangible Cultural Heritage Authorised Discourse
No full textThis article uses discourse analysis to consider the criteria used in decisions on inscription of intangible cultural heritage. It specifically examines the decisions made on two elements of Classical Horsemanship, one submission by France and one by Austria, for inscription on the list of Representative heritage
Jus ad Bellum: nuclear weapons and the inherent right of self-defence
Get PDFThe lawfulness of a State’s recourse to the ‘nuclear option’ as a means of self-defence is still a discussion which, sits uncomfortably amongst most scholars, partly, because the seminal advisory opinion on the Legality of the Threat or Use of Nuclear Weapons delivered by the International Court of Justice in 1996 remains shrouded in legal uncertainty and, perhaps more importantly, because the threshold needed to lawfully invoke the doctrine of self-defence is set so high, and rightly so. Only under exceptional circumstances would a State meet the cardinal requirements of ‘necessity’ and ‘proportionality’. The use of a nuclear weapon as a means of self-defence lies at the very edge of the spectrum. That is not to say that recourse to conventional weapons automatically fulfils the necessity and proportionality requirements
Apples and Pears: Symbolism and Influence in Daphne du Maurier’s ‘The Apple Tree’ and Katherine Mansfield’s ‘Bliss’
No full textStructure-guided selection of specificity determining positions in the human kinome
No full textBackground:
The human kinome contains many important drug targets. It is well-known that inhibitors of protein kinases bind with very different selectivity profiles. This is also the case for inhibitors of many other protein families. The increased availability of protein 3D structures has provided much information on the structural variation within a given protein family. However, the relationship between structural variations and binding specificity is complex and incompletely understood. We have developed a structural bioinformatics approach which provides an analysis of key determinants of binding selectivity as a tool to enhance the rational design of drugs with a specific selectivity profile.
Results:
We propose a greedy algorithm that computes a subset of residue positions in a multiple sequence alignment such that structural and chemical variation in those positions helps explain known binding affinities. By providing this information, the main purpose of the algorithm is to provide experimentalists with possible insights into how the selectivity profile of certain inhibitors is achieved, which is useful for lead optimization. In addition, the algorithm can also be used to predict binding affinities for structures whose affinity for a given inhibitor is unknown. The algorithm’s performance is demonstrated using an extensive dataset for the human kinome.
Conclusion:
We show that the binding affinity of 38 different kinase inhibitors can be explained with consistently high precision and accuracy using the variation of at most six residue positions in the kinome binding site. We show for several inhibitors that we are able to identify residues that are known to be functionally important