3D reconstruction of complex dielectric function of the glass during the femtosecond micro-fabrication

We measure complex amplitude of scattered wave in the far field, and justify theoretically and numerically solution of the inverse scattering problem. This allows single-shot reconstructing of dielectric function distribution during direct femtosecond laser micro-fabrication.

3D Reconstruction of the complex dielectric function of glass during femtosecond laser micro-fabrication

We report on a new technique to reconstruct the 3D dielectric function change in transparent dielectric materials and the application of the technique for on-line monitoring of refractive index modification in BK7 glass during direct femtosecond laser microfabrication. The complex optical field scattered from the modified region is measured using two-beam, single-shot interferogram and the distribution of the modified refractive index is reconstructed by numerically solving the inverse scattering problem in Born approximation. The optical configuration suggested is further development of digital holographic microscopy (DHM). It takes advantage of high spatial resolution and almost the same optical paths for both interfering beams, and allows ultrafast time resolution.

Some aspects of system design for production management in the rolling-mill industry

Case studies in copper-alloy rolling mill companies showed that existing planning systems suffer from numerous shortcomings. Where computerised systems are in use, these tend to simply emulate older manual systems and still rely heavily on modification by experienced planners on the shopfloor. As the size and number of orders increase, the task of process planners, while seeking to optimise the manufacturing objectives and keep within the production constraints, becomes extremely complicated because of the number of options for mixing or splitting the orders into batches. This thesis develops a modular approach to computerisation of the production management and planning functions. The full functional specification of each module is discussed, together with practical problems associated with their phased implementation. By adapting the Distributed Bill of Material concept from Material Requirements Planning (MRP) philosophy, the production routes generated by the planning system are broken down to identify the rolling stages required. Then to optimise the use of material at each rolling stage, the system generates an optimal cutting pattern using a new algorithm that produces practical solutions to the cutting stock problem. It is shown that the proposed system can be accommodated on a micro-computer, which brings it into the reach of typical companies in the copper-alloy rolling industry, where profit margins are traditionally low and the cost of widespread use of mainframe computers would be prohibitive.

Design and function of trilobite exoskeletons

The fossil arthropod Class Trilobita is characterised by the possession of a highly mineralised dorsal exoskeleton with an incurved marginal flange (doublure). This cuticle is usually the only part of the organism to be preserved. Despite the common occurrence of trilobites in Palaeozoic sediments, the original exoskeletal mineralogy has not been determined previously. Petrographic data involving over seventy trilobite species, ranging in age from Cambrian to Devonian, together with atomic absorption and stable isotope analyses, indicate a primary low-magnesian calcite composition. Trilobite cuticles exhibit a variety of preservational textures which are related to the different diagenetic realms through which they have passed. A greater knowledge of post-depositional processes and the specific features they produce, has enabled post-mortem artefacts to be distinguished from primary cuticular microstructures. Alterations of the cuticle can either enhance or destroy primary features, and their effects are best observed in thin-sections, both under transmitted light and cathodoluminescence. Well-preserved trilobites often retain primary microstructures such as laminations, canals, and tubercles. These have been examined in stained thin-sections and by scanning electron microscopy, from as wide a range of trilobites as possible. Construction of sensory field maps has shown that although the basic organisation of the exoskeleton is the same in all trilobites, the types of microstructures found, and their distribution is species-specific. The composition, microstructure, and architecture of the trilobite exoskeleton have also been studied from a biomechanical viewpoint. Total cuticle thickness, and the relative proportions of the different layers, together with the overall architecture all affected the mechanical properties of the exoskeleton.

The investigation of the sensitivity gradient of the visual field, as a function of stimulus dynamic range, in the normal and abnormal eye

The study utilized the advanced technology provided by automated perimeters to investigate the hypothesis that patients with retinitis pigmentosa behave atypically over the dynamic range and to concurrently determine the influence of extraneous factors on the format of the normal perimetric sensitivity profile. The perimetric processing of some patients with retinitis pigmentosa was considered to be abnormal in either the temporal and/or the spatial domain. The standard size III stimulus saturated the central regions and was thus ineffective in detecting early depressions in sensitivity in these areas. When stimulus size was scaled in inverse proportion to the square root of ganglion cell receptive field density (M-scaled), isosensitive profiles did not result, although cortical representation was theoretically equivalent across the visual field. It was conjectured that this was due to variations in the ganglion cell characteristics with increasing peripheral angle, most notably spatial summation. It was concluded that the development of perimetric routines incorporating stimulus sizes adjusted in proportion to the coverage factor of retinal ganglion cells would enhance the diagnostic capacity of perimetry. Good general and local correspondence was found between perimetric sensitivity and the available retinal cell counts. Intraocular light scatter arising both from simulations and media opacities depressed perimetric sensitivity. Attenuation was greater centrally for the smaller LED stimuli, whereas the reverse was true for the larger projected stimuli. Prior perimetric experience and pupil size also demonstrated eccentricity-dependent effect on sensitivity. Practice improved perimetric sensitivity for projected stimuli at eccentricities greater than or equal to 30o; particularly in the superior region. Increase in pupil size for LED stimuli enhanced sensitivity at eccentricities greater than 10o. Conversely, microfluctuation in the accommodative response during perimetric examination and the correction of peripheral refractive error had no significant influence on perimetric sensitivity.

Improving the function of islet and beta-cell grafts

Background: Human islet transplantation would offer a less invasive and more physiological alternative than whole pancreas transplantation and insulin injections respectively for the treatment of diabetes mellitus if islet graft survival can be improved. Initial recipient post-transplant insulin independence declines to <10% after 5 years. Factors contributing to graft failure include enzymatic disruption of the islet microenvironment during isolation, diabetogenic effects of immunosuppressants and metabolic stress resulting from slow revascularisation. Aims: To investigate the effect of co-culture in both static (SC) and rotational culture (RC) of BRINBDII beta-cells (Dl1) and human umbilical vein endothelial cells (HUVEC) on Dl1 insulin secretion; and the effect of a thiazolidinedione (TZD) on DII function and HUVEC proliferation. To assess the effect of culture media, SC, RC and a TZD on human islet morphology, insulin secretion and VEGF production. To initiate in vivo protocol development for assessment of revascularisation of human islet grafts. Methods: D11 cells were cultured +/-TZD and co-cultured with HUVEC +/-TZD in SC and RC. Dl1 insulin secretion was induced by static incubation with low glucose (1.67mM), high glucose (l6.7mM: and high glucose with 10mM theophylline (G+T) and determined by ELISA. HUVEC were cultured +/-TZD in SC and RC and proliferation was assessed by ATP luminescence assay and VEGF ELISA. D II and HUVEC morphology was determined by immunocytochemistry. Human islets were cultured in SC and RC in various media +/-TZD. Insulin secretion was determined as above and VEGF production by fluorescence immunocytochemistry (FI) and ELISA. Revascularisation of islet grafts was assessed by vascular corrosion cast and FI. Results: Dll cultures showed significantly increased insulin secretion in response to 16.7mM and G+T over basal; this was enhanced by RC and further improved by adding 10mM TZD. Untreated Dll/HUVEC co-cultures displayed significantly increased insulin secretion in response to 16.7mM and G+T over basal, again enhanced by RC and improved with 10mM TZD. 10mM TZD significantly increased HUVEC proliferation over control. Human islets maintained in medium 199 (mI99) in SC and RC exhibited comparable maintenance of morphology and insulin secretory profiles compared to islets maintained in RPMI, endothelial growth media and dedicated islet medium Miami# I. All cultures showed significantly increased insulin secretion in response to 16.7mM and G+T over basal; this was enhanced by RC and in certain instances further improved by adding 25mM TZD. TZD increased VEGF production and release as determined by ELISA. Post-implant vascular corrosion casts of mouse kidneys analysed by x-ray micro tomography indicates a possible TZD enhancement of microvessel growth via VEGF upregulation. Conclusions: D II /HUVEC co-culture in SC or RC does not alter the morphology of either cell type and supports D 11 function. TZD improves 0 I I and D I I/HUVEC SC and RC co-culture insulin secretion while increasing HUVEC proliferation. Human islet RC supports islet functional viability and structural integrity compared to SC while the addition of TZD occasionally further improves secretagogue induced insulin secretion. Expensive, 'dedicated' islet media showed no advantage over ml99 in terms of maintaining islet morphology or function. TZD upregulates VEGF in islets as shown by ELISA and suggested by x-ray micro tomography analysis of vascular corrosion casts. Maintenance of islets in RC and treatment with TZD prior to transplant may improve the functional viability and revascularisation rate of islet grafts.

The Riesz transform and simultaneous representations of phase, energy and orientation in spatial vision

To represent the local orientation and energy of a 1-D image signal, many models of early visual processing employ bandpass quadrature filters, formed by combining the original signal with its Hilbert transform. However, representations capable of estimating an image signal's 2-D phase have been largely ignored. Here, we consider 2-D phase representations using a method based upon the Riesz transform. For spatial images there exist two Riesz transformed signals and one original signal from which orientation, phase and energy may be represented as a vector in 3-D signal space. We show that these image properties may be represented by a Singular Value Decomposition (SVD) of the higher-order derivatives of the original and the Riesz transformed signals. We further show that the expected responses of even and odd symmetric filters from the Riesz transform may be represented by a single signal autocorrelation function, which is beneficial in simplifying Bayesian computations for spatial orientation. Importantly, the Riesz transform allows one to weight linearly across orientation using both symmetric and asymmetric filters to account for some perceptual phase distortions observed in image signals - notably one's perception of edge structure within plaid patterns whose component gratings are either equal or unequal in contrast. Finally, exploiting the benefits that arise from the Riesz definition of local energy as a scalar quantity, we demonstrate the utility of Riesz signal representations in estimating the spatial orientation of second-order image signals. We conclude that the Riesz transform may be employed as a general tool for 2-D visual pattern recognition by its virtue of representing phase, orientation and energy as orthogonal signal quantities.

Developing the public health function of locum pharmacists under the auspices of the new pharmacy contract

Focal Point - There are reduced opportunities for locum pharmacists to access training and education that meets their needs and enables them to play a full role under the new pharmacy contract - Eighty-six per cent of locums consider themselves to be more health professional than business person, compared to just 48% of pharmacy owners - Forty per cent of locums believe that a lack of access to training is a major barrier to the development of their public health function - While locum pharmacists are arguably more likely to embrace 'professionalising', patient-care-based roles, they are also the group least likely to be able to access the necessary training to fulfill such roles Introduction It has been suggested that locum pharmacists do not want the business-based responsibilities (e.g. staff management, meeting targets, etc) that come with pharmacy management.1 Research also suggests that locums derive great satisfaction from the health-professional aspects of the pharmacists’ role (e.g. patient contact, the provision of advice, etc).1 However, upon the introduction of the new pharmacy contract (April 2005), concerns were expressed that it was becoming increasingly difficult for locum pharmacists to access training and education that would meet their needs and enable them to play a full role under the new framework.2,3 Method After piloting, in August 2006 a self-completion postal questionnaire was sent to a random sample of practising community pharmacists, stratified for country and sex, within Great Britain (n = 1998), with a follow-up to non-responders 4 weeks later. Data were analysed using SPSS (v12.0). A final response rate of 51% (n = 1023/1998) was achieved. Respondents were asked ‘indicate how you view yourself as a pharmacist’ – in terms of their relative focus on the health-professional and business aspects of their role. Respondents were also asked ‘do you consider a lack of training opportunities to be a barrier to the development of the public health role of community pharmacists?’. Results Locums were significantly more likely than owners or employees to consider each factor a major barrier. Discussion Four in 10 locums consider a lack of training opportunities to constitute a major barrier to the development of their public health function. Pharmacy may not be able to provide the services required of it by the policy agenda if pharmacists are unable to be involved in extended role activities through a lack of training opportunities. Therefore, the paradox that needs to be addressed is that while locum pharmacists are arguably more likely to embrace ‘professionalising’, patient-care-based roles, they are also the group least likely to be able to access training to fulfil such roles. The training needs of this large subset of the pharmacist population need to be assessed and met if the whole community pharmacy workforce is going to maximise its contribution to public health under the new contractual framework. References 1 Shann P, Hassell K. An exploration of the diversity and complexity of the pharmacy locum workforce. London: Royal Pharmaceutical Society of Great Britain; 2004. 2 Almond M. Locums – key players in workforce – cast adrift as contract launched. Pharm J 2005;274:420. 3 Bishop DH. A lack of appreciation of what really happens. Pharm J 2005;274:451.

Multiple roles of charged amino acids in cytoplasmic loop 7 for expression and function of the multidrug and organic anion transporter MRP1 (ABCC1)

Multidrug resistance protein MRP1 mediates the ATP-dependent efflux of many chemotherapeutic agents and organic anions. MRP1 has two nucleotide binding sites (NBSs) and three membrane spanning domains (MSDs) containing 17 transmembrane helices linked by extracellular and cytoplasmic loops (CL). Homology models suggest that CL7 (amino acids 1141-1195) is in a position where it could participate in signaling between the MSDs and NBSs during the transport process. We have individually replaced eight charged residues in CL7 with Ala, and in some cases, an amino acid with the same charge, and then investigated the effects on MRP1 expression, transport activity, and nucleotide and substrate interactions. A triple mutant in which Glu(1169), Glu(1170), and Glu(1172) were all replaced with Ala was also examined. The properties of R1173A and E1184A were comparable with those of wild-type MRP1, whereas the remaining mutants were either poorly expressed (R1166A, D1183A) or exhibited reduced transport of one or more organic anions (E1144A, D1179A, K1181A, (1169)AAQA). Same charge mutant D1183E was also not expressed, whereas expression and activity of R1166K were similar to wild-type MRP1. The moderate substrate-selective changes in transport activity displayed by mutants E1144A, D1179A, K1181A, and (1169)AAQA were accompanied by changes in orthovanadate-induced trapping of [alpha-(32)P]azidoADP by NBS2 indicating changes in ATP hydrolysis or release of ADP. In the case of E1144A, estradiol glucuronide no longer inhibited trapping of azidoADP. Together, our results demonstrate the extreme sensitivity of CL7 to mutation, consistent with its critical and complex dual role in both the proper folding and transport activity of MRP1.

Exceptional function of nanoporous metal organic framework particles in emulsion stabilisation

A new concept of nanoporous metal organic framework particles stabilising emulsions was investigated. The copper benzenetricarboxylate MOF particles adsorbed at the oil/water interface play an exceptional role in stabilising both oil-in-water and water-in-oil emulsions. © 2013 The Royal Society of Chemistry.

Evaluation of the auto-refraction function of the Nidek OPD-Scan III

Background: The aim was to evaluate the validity and repeatability of the auto-refraction function of the Nidek OPD-Scan III (Nidek Technologies, Gamagori, Japan) compared with non-cycloplegic subjective refraction. The Nidek OPD-Scan III is a new aberrometer/corneal topographer workstation based on the skiascopy principle. It combines a wavefront aberrometer, topographer, autorefractor, auto keratometer and pupillometer/pupillographer. Methods: Objective refraction results obtained using the Nidek OPD-Scan III were compared with non-cycloplegic subjective refraction for 108 eyes of 54 participants (29 female) with a mean age of 23.7±9.5 years. Intra-session and inter-session variability were assessed on 14 subjects (28 eyes). Results: The Nidek OPD-Scan III gave slightly more negative readings than results obtained by subjective refraction (Nidek mean difference -0.19±0.36 DS, p<0.01 for sphere; -0.19±0.35 DS, p<0.01 for mean spherical equivalent; -0.002±0.23 DC, p=0.91 for cylinder; -0.06±0.38 DC, p=0.30 for J0 and -0.36±0.31 DC for J45, p=0.29). Auto-refractor results for 74 per cent of spherical readings and 60 per cent of cylindrical powers were within±0.25 of subjective refraction. There was high intra-session and inter-session repeatability for all parameters; 90 per cent of inter-session repeatability results were within 0.25 D. Conclusion: The Nidek OPD-Scan III gives valid and repeatable measures of objective refraction when compared with non-cycloplegic subjective refraction. © 2013 The Authors. Clinical and Experimental Optometry © 2013 Optometrists Association Australia.