Quadrature wavelength scanning interferometry.

A novel method to double the measurement range of wavelength scanning interferometery (WSI) is described. In WSI the measured optical path difference (OPD) is affected by a sign ambiguity, that is, from an interference signal it is not possible to distinguish whether the OPD is positive or negative. The sign ambiguity can be resolved by measuring an interference signal in quadrature.

Phase and fringe order determination in wavelength scanning interferometry.

A method to obtain unambiguous surface height measurements using wavelength scanning interferometry with an improved repeatability, comparable to that obtainable using phase shifting interferometry, is reported. Rather than determining the conventional fringe frequency-derived z height directly, the method uses the frequency to resolve the fringe order ambiguity, and combine this information with the more accurate and repeatable fringe phase derived z height. A theoretical model to evaluate the method's performance in the presence of additive noise is derived and shown to be in good agreement with experiments.

Mathematics for modern precision engineering.

The aim of precision engineering is the accurate control of geometry. For this reason, mathematics has a long association with precision engineering: from the calculation and correction of angular scales used in surveying and astronomical instrumentation to statistical averaging techniques used to increase precision. This study illustrates the enabling role the mathematical sciences are playing in precision engineering: modelling physical processes, instruments and complex geometries, statistical characterization of metrology systems and error compensation.

Methodologies for assessing local surface texture features that are relevant to cell attachment.

In this paper, we describe techniques for extracting features from surface topography data, gathered by a 3D-microscopy system, on a length scale that is relevant for cell attachment. The feature parameters considered include standard surface roughness parameters applied to the complete surface as well as new feature parameters designed to quantify local variations in surface topography potentially influencing cell behaviour. Methodologies have been developed both to determine the degree of homogeneity or isotropy of a surface and to compare the topographies of different samples.

NCF1 (p47phox) and ncf1 pseudogenes are not associated with inflammatory bowel disease.

Crohn's disease (CD) and ulcerative colitis (UC) have a strong genetic component, contributing to a patient's susceptibility for inflammatory bowl disease (IBD). Linkage analysis has detected an IBD susceptibility locus in a region on chromosome 7q that encompasses the p47 (NCF1) gene and p47 (PsiNCF1) pseudogenes. Involvement of the NCF1 locus in IBD was supported by the observation that chronic inflammation of the bowel is a feature of chronic granulomatous disease caused by NCF1 mutation in 25% of cases.