Thick bone section preparation using a silicon-rubber-based sealant

A method has been developed, using a silicon-rubber-based sealant, which allows 2–3-mm-thick specimens to be maintained in a protected fluid environment for a number of months, without risk of dehydration. Following this, the specimen can be retrieved, stained, embedded and sectioned further. For example, 2-mm-thick sections of fixed unstained bone are easily examined by means of epi-illuminated polarized light and fluorescence microscopies using either conventional or confocal optics. The method could easily be extended to other tissues, for example brain tissue.     

Estimation of individual feature surface area with the vertical spatial grid

The area of an individual bounded surface (e.g. the boundary of a properly sampled cell) can be estimated from an isotropic uniform random stack of parallel sections, or of non-invasive planar scans, using the well-known spatial grid. A standing problem was to estimate the area of an individual bounded surface with an arbitrary degree of accuracy from a vertical (i.e. not isotropic) stack of sections or scans. A new tool to do this, called the ‘vertical spatial grid’, is presented.     

On asymmetric stochastic bang-bang control†

Three stochastic bang-bang control problems, the predicted miss, the linear regulator, and a complete observation model, are shown to have formally similar solutions under an asymmetric boundedness condition on the control u(t), 0<t<T.     

The application of remote sensing techniques to the monitoring of a sea outfall system

Preliminary results are presented from an airborne survey of a long sea outfall. Multispectral scanner data obtained from separate flights are discussed, and assessed favourably as diagnostic indicators of outfall performance. In particular, it is demonstrated that the processed data can be used to locate and count the individual sources of discharge within the effluent plume.     

Verification of cell viability at progressively higher scanning forces using a hybrid atomic force and fluorescence microscope

Dry 40× and 60× microscope objectives were fitted with opaque black masks in order to eliminate reflection and scattering of light off the objective front lens assembly during oblique incidence reflection (OIR) microscopy. The reflection and scattering are shown to induce background glare that leads to degradation in the quality of the OIR images. Mask prototypes were designed and machined to snap onto the spring-loaded retractable front lens assembly of each objective. OIR images of live cells and normalized intensity line profiles are used to demonstrate that, if these alterations to the housing of the objective are implemented, background glare is significantly reduced with the 60× objective, and virtually eliminated with the 40× objective.     

Microbiology of brines used to mature feta cheese

The microfloras of brines from two commercial factories manufacturing traditional feta cheese were examined over a period of 60 days, which is the normal maturation time for Greek feta. Non-starter lactic acid bacteria were the dominant group, and Lactobacillus paracasei ssp. paracasei and Lactobacillus plantarum were the principal species identified. A number of strains of Debaryomyces hansenii were isolated from the brines, and both the yeasts and the lactobacilli possessed enzymes capable of degrading fat or protein. It is suggested that these microfloras play an important role in the maturation of feta cheese. No recognized pathogens were isolated from the brines of' either factory.