Quality Assurance of Cervical Smear Slide Inspection Using a Novel Eye-Tracking Technique

A novel objective quality assurance system for smear slide screening is investigated in this thesis. A method of data validation was developed that compares data from an eye tracked image display, machine image colour texture analysis and expert judgements in a statistical manner to identify salient areas of cervical cytological images. These data are used to construct screener performance profiles, which have been compared to screener experience. The experimental methodology is described and how the screener performance profile is constructed. Results from a study of 10 screeners, checkers and pathologists are presented showing predicted trends of human performance. Relations to experience and strategy are also shown, though these relationships are not statistically significant. A standardised quality assurance test is developed that profiles screeners across many performance measures. Highly significant correlations were found between fixation saliency and machine colour texture (maxima density), though fixation saliency suffers from a lack of a significant statistical basis. Further fixation data is needed, however if it conforms to the existing trends then the results would support the new data validation method as a framework from which image analysis techniques applied to cytology may be objectively tested. Furthermore, this new approach to cervical cytology quality assurance would have the potential to further reduce human errors in the cervical smear inspection process by lowering levels of observer variation found in all aspects of the cervical screening process

A pilot study of marking accuracy and mental workload as measures of OSCE examiner performance

Background The Objective Structured Clinical Examination (OSCE) is now a standard assessment format and while examiner training is seen as essential to assure quality, there appear to be no widely accepted measures of examiner performance. Methods The objective of this study was to determine whether the routine training provided to examiners improved their accuracy and reduced their mental workload. Accuracy was defined as the difference between the rating of each examiner and that of an expert group expressed as the mean error per item. At the same time the mental workload of each examiner was measured using a previously validated secondary task methodology. Results Training was not associated with an improvement in accuracy (p = 0.547) and that there was no detectable effect on mental workload. However, accuracy was improved after exposure to the same scenario (p < 0.001) and accuracy was greater when marking an excellent compared to a borderline performance. Conclusions This study suggests that the method of training OSCE examiners studied is not effective in improving their performance, but that average item accuracy and mental workload appear to be valid methods of assessing examiner performance

Student E-Learning Intrinsic Motivation: A Qualitative Analysis

In the age of life-long learning and increased competition for time, motivation becomes a salient issue. Students need to be more intrinsically motivated in the absence of more formal structure. This is especially true in online learning environments where direct instructor influence is mitigated. Online learning environments typically embrace many choices in ways in which learning material is presented and interaction with students is supported in both individual and collaborative contexts. As such, it is imperative that we better understand the implications of various learning activities and associated technologies on aspects of intrinsic motivation in e-learning. In this paper we examine these effects through qualitative analysis of semi-structured interviews with students in an online MBA program. Results encourage use of a pedagogically driven portfolio of learning activities supported by well-selected and integrated audio, video, and data technologies. Extension to use of mobile devices in ubiquitous e-learning contexts is explored

Transcripts for transforming growth factors in human breast cancer: clinical correlates.

The levels of mRNA for transforming growth factors (TGF alpha and beta) and the epidermal growth factor receptor (EGFR) were determined in 69 human breast carcinomas and 20 biopsies of non-neoplastic breast tissue by dot blot hybridisation analysis. TGF alpha mRNA was detected in 42% of cancers and 44% of non-neoplastic breast tissue at low levels. TGF beta mRNA was found in all breast cancers and non-neoplastic breast tissues, but the levels of TGF beta mRNA were found to be higher in breast cancers (P = 0.01). EGFR mRNA was detected in 55% of breast cancers and in all non-neoplastic breast tissue tested. The presence of EGFR mRNA was inversely related to oestrogen receptor (ER) status (P = 0.0001). Coexpression of TGF alpha and EGFR was observed in 28% of the carcinomas, and significantly more commonly in ER negative tumours (P = 0.01). No significant relationship was found between histological grade, tumour cellularity or tumour desmoplasia and expression of either the TGFs or of EGFR mRNA. High levels of TGF beta were, however, associated with the absence of lymph node metastases at presentation (P = 0.05). Levels of TGF alpha and beta and EGFR mRNA were analysed in relationship to the relapse-free and overall survival of patients with breast cancer, but none was found to predict significantly the outcome in these patients. Longer clinical follow-up and larger numbers of patients are required to determine whether TGFs will prove a useful marker for prognosis in breast cancer patients

The prognostic significance of transforming growth factors in human breast cancer.

Transforming growth factor alpha (TGF alpha) and Transforming growth factor beta-1 (TGF-beta 1) are growth regulatory for breast cancer cell lines in vitro and several studies have suggested that levels of the receptor for TGF alpha, the epidermal growth factor (EGFR) in tumour biopsies predict relapse and survival. We have examined the prognostic significance of TGF alpha, TGF-beta 1 and EGFR mRNA expression in a series of patients with primary breast cancer with a median follow up period of 60 months. In 167 patients the expression of TGF-beta 1 was inversely correlated with node status (P = 0.065) but not ER status, tumour size or menopausal status. Patients with high levels of TGF-beta 1 had a longer disease free interval with a significantly longer probability of survival at 80 months although the overall relapse free survival was not increased. EGFR mRNA expression was measured in 106 patients and was inversely correlated with ER status (P = 0.018). EGFR levels did not predict for early relapse or survival. TGF alpha mRNA levels were measured in 104 patients, no correlation was seen tumour size, node status, Er status, or clinical outcome

Mixed-Mode Oscillations in a Stochastic, Piecewise-Linear System

We analyze a piecewise-linear FitzHugh-Nagumo model. The system exhibits a canard near which both small amplitude and large amplitude periodic orbits exist. The addition of small noise induces mixed-mode oscillations (MMOs) in the vicinity of the canard point. We determine the effect of each model parameter on the stochastically driven MMOs. In particular we show that any parameter variation (such as a modification of the piecewise-linear function in the model) that leaves the ratio of noise amplitude to time-scale separation unchanged typically has little effect on the width of the interval of the primary bifurcation parameter over which MMOs occur. In that sense, the MMOs are robust. Furthermore we show that the piecewise-linear model exhibits MMOs more readily than the classical FitzHugh-Nagumo model for which a cubic polynomial is the only nonlinearity. By studying a piecewise-linear model we are able to explain results using analytical expressions and compare these with numerical investigations.Comment: 25 pages, 10 figure

Mode-Locking in Driven Disordered Systems as a Boundary-Value Problem

We study mode-locking in disordered media as a boundary-value problem. Focusing on the simplest class of mode-locking models which consists of a single driven overdamped degree-of-freedom, we develop an analytical method to obtain the shape of the Arnol'd tongues in the regime of low ac-driving amplitude or high ac-driving frequency. The method is exact for a scalloped pinning potential and easily adapted to other pinning potentials. It is complementary to the analysis based on the well-known Shapiro's argument that holds in the perturbative regime of large driving amplitudes or low driving frequency, where the effect of pinning is weak.Comment: 6 pages, 7 figures, RevTeX, Submitte

A Monitor of Beam Polarization Profiles for the TRIUMF Parity Experiment

TRIUMF experiment E497 is a study of parity violation in pp scattering at an energy where the leading term in the analyzing power is expected to vanish, thus measuring a unique combination of weak-interaction flavour conserving terms. It is desired to reach a level of sensitivity of 2x10^-8 in both statistical and systematic errors. The leading systematic errors depend on transverse polarization components and, at least, the first moment of transverse polarization. A novel polarimeter that measures profiles of both transverse components of polarization as a function of position is described.Comment: 19 pages LaTeX, 10 PostScript figures. To appear in Nuclear Instruments and Methods in Physics Research, Section

Industrial strategy and the UK regions: Sectorally narrow and spatially blind

The UK government's new Industrial Strategy could have a significant impact on the country's regions and localities. However, this has received little attention to date. The analysis presented here examines the existing location of the sectors targeted by the first phase of the Industrial Strategy Challenge Fund and the location of the R&D laboratories likely to be first in line for funding. In focusing on an extremely narrow range of sectors, the Fund is likely to have limited impact on the UK's persistent regional inequalities. The activities eligible for support account for relatively little of manufacturing or the rest of the economy and the basis of this targeting and its potential distributional consequences are spatially blind. As such, it runs the risk of widening regional divides in prosperity