Eyes on 3D-Current 3D biomimetic disease concept models and potential applications in age-related macular degeneration

Three dimensional cellular models that mimic disease are being increasingly investigated and have opened an exciting new research area into understanding pathomechanisms. The advantage of 3D in vitro disease models is that they allow systematic and in-depth studies of physiological and pathophysiological processes with less costs and ethical concerns that have arisen with animal models. The purpose of the 3D approach is to allow crosstalk between cells and microenvironment, and with cues from the microenvironment, cells can assemble their niche similar to in vivo conditions. The use of 3D models for mimicking disease processes such as cancer, osteoarthritis etc., is only emerging and allows multidisciplinary teams consisting of tissue engineers, biologist biomaterial scientists and clinicians to work closely together. While in vitro systems require rigorous testing before they can be considered as replicates of the in vivo model, major steps have been made, suggesting that they will become powerful tools for studying physiological and pathophysiological processes. This paper aims to summarize some of the existing 3D models and proposes a novel 3D model of the eye structures that are involved in the most common cause of blindness in the Western World, namely age-related macular degeneration (AMD).

A snapshot of radiation therapy techniques and technology in Queensland : an aid to mapping undergraduate curriculum

Introduction: Undergraduate students studying the Bachelor of Radiation Therapy at Queensland University of Technology (QUT) attend clinical placements in a number of department sites across Queensland. To ensure that the curriculum prepares students for the most common treatments and current techniques in use in these departments, a curriculum matching exercise was performed. Methods: A cross-sectional census was performed on a pre-determined “Snapshot” date in 2012. This was undertaken by the clinical education staff in each department who used a standardized proforma to count the number of patients as well as prescription, equipment, and technique data for a list of tumour site categories. This information was combined into aggregate anonymized data. Results: All 12 Queensland radiation therapy clinical sites participated in the Snapshot data collection exercise to produce a comprehensive overview of clinical practice on the chosen day. A total of 59 different tumour sites were treated on the chosen day and as expected the most common treatment sites were prostate and breast, comprising 46% of patients treated. Data analysis also indicated that intensity-modulated radiotherapy (IMRT) use is relatively high with 19.6% of patients receiving IMRT treatment on the chosen day. Both IMRT and image-guided radiotherapy (IGRT) indications matched recommendations from the evidence. Conclusion: The Snapshot method proved to be a feasible and efficient method of gathering useful

The relationship between self-esteem and psychological adjustment in young adolescents

The study adopts a multi-dimensional construct of self-esteem to examine the relationship between self-perception and psychological adjustment in order to identify specific dimensions that discriminate between disturbed and non-disturbed groups. The disturbed group (n = 33) is derived from a clinical sample and are matched with a non-disturbed group (n = 33) of adolescents. Results indicate that dimensional self-concept scores are significantly lower for clinical subjects while there are no significant differences between groups on the mathematics, honesty, and physical ability dimensions. These findings provide a more fine grained understanding of the relationship between self-esteem and psychological adjustment and emphasize the need to examine self-esteem in terms of its particular dimensions.

Mapping quantitative trait loci in a wild population using linkage and linkage disequilibrium analyses

Historical information can be used, in addition to pedigree, traits and genotypes, to map quantitative trait locus (QTL) in general populations via maximum likelihood estimation of variance components. This analysis is known as linkage disequilibrium (LD) and linkage mapping, because it exploits both linkage in families and LD at the population level. The search for QTL in the wild population of Soay sheep on St. Kilda is a proof of principle. We analysed the data from a previous study and confirmed some of the QTLs reported. The most striking result was the confirmation of a QTL affecting birth weight that had been reported using association tests but not when using linkage-based analyses. Copyright © Cambridge University Press 2010.

Prediction of IBD based on population history for fine gene mapping

A novel multiple regression method (RM) is developed to predict identity-by-descent probabilities at a locus L (IBDL), among individuals without pedigree, given information on surrounding markers and population history. These IBDL probabilities are a function of the increase in linkage disequilibrium (LD) generated by drift in a homogeneous population over generations. Three parameters are sufficient to describe population history: effective population size (Ne), number of generations since foundation (T), and marker allele frequencies among founders (p). IBD L are used in a simulation study to map a quantitative trait locus (QTL) via variance component estimation. RM is compared to a coalescent method (CM) in terms of power and robustness of QTL detection. Differences between RM and CM are small but significant. For example, RM is more powerful than CM in dioecious populations, but not in monoecious populations. Moreover, RM is more robust than CM when marker phases are unknown or when there is complete LD among founders or Ne is wrong, and less robust when p is wrong. CM utilises all marker haplotype information, whereas RM utilises information contained in each individual marker and all possible marker pairs but not in higher order interactions. RM consists of a family of models encompassing four different population structures, and two ways of using marker information, which contrasts with the single model that must cater for all possible evolutionary scenarios in CM.

Mapping of multiple quantitative trait loci affecting bovine spongiform encephalopathy

A whole-genome scan was conducted to map quantitative trait loci (QTL) for BSE resistance or susceptibility. Cows from four half-sib families were included and 173 microsatellite markers were used to construct a 2835-cM (Kosambi) linkage map covering 29 autosomes and the pseudoautosomal region of the sex chromosome. Interval mapping by linear regression was applied and extended to a multiple-QTL analysis approach that used identified QTL on other chromosomes as cofactors to increase mapping power. In the multiple-QTL analysis, two genome-wide significant QTL (BTA17 and X/Y ps) and four genome-wide suggestive QTL (BTA1, 6, 13, and 19) were revealed. The QTL identified here using linkage analysis do not overlap with regions previously identified using TDT analysis. One factor that may explain the disparity between the results is that a more extensive data set was used in the present study. Furthermore, methodological differences between TDT and linkage analyses may affect the power of these approaches.

Power of QTL detection using association tests with family controls

The power of testing for a population-wide association between a biallelic quantitative trait locus and a linked biallelic marker locus is predicted both empirically and deterministically for several tests. The tests were based on the analysis of variance (ANOVA) and on a number of transmission disequilibrium tests (TDT). Deterministic power predictions made use of family information, and were functions of population parameters including linkage disequilibrium, allele frequencies, and recombination rate. Deterministic power predictions were very close to the empirical power from simulations in all scenarios considered in this study. The different TDTs had very similar power, intermediate between one-way and nested ANOVAs. One-way ANOVA was the only test that was not robust against spurious disequilibrium. Our general framework for predicting power deterministically can be used to predict power in other association tests. Deterministic power calculations are a powerful tool for researchers to plan and evaluate experiments and obviate the need for elaborate simulation studies.

Genome-wide search for markers associated with bovine spongiform encephalopathy

A genome-wide search for markers associated with BSE incidence was performed by using Transmission-Disequilibrium Tests (TDTs). Significant segregation distortion, i.e., unequal transmission probabilities of alleles within a locus, was found for three marker loci on Chromosomes (Chrs) 5, 10, and 20. Although TDTs are robust to false associations owing to hidden population substructures, it cannot distinguish segregation distortion caused by a true association between a marker and bovine spongiform encephalopathy (BSE) from a population-wide distortion. An interaction test and a segregation distortion analysis in half-sib controls were used to disentangle these two alternative hypotheses. None of the markers showed any significant interaction between allele transmission rates and disease status, and only the marker on Chr 10 showed a significant segregation distortion in control individuals. Nevertheless, the control group may have been a mixture of resistant and susceptible but unchallenged individuals. When new genotypes were generated in the vicinity of these three markers, evidence for an association with BSE was confirmed for the locus on Chr 5.

A vibrational spectroscopic study of philipsbornite PbAl3(AsO4)2(OH)5⋅H2O-molecular structural implications and relationship to the crandallite subgroup arsenates

The presence of arsenic in the environment is a hazard. The accumulation of arsenate by a range of cations in the formation of minerals provides a mechanism for the remediation of arsenate contamination. The formation of the crandallite group of minerals provides a mechanism for arsenate accumulation. Among the crandallite minerals are philipsbornite, arsenocrandallite and arsenogoyazite. Raman spectroscopy complimented with infrared spectroscopy has enabled aspects of the structure of philipsbornite to be studied. The Raman spectrum of philipsbornite displays an intense band at around 840 cm−1 attributed to the overlap of the symmetric and antisymmetric stretching modes. Raman bands observed at 325, 336, 347, 357, 376 and 399 cm−1 are assigned to the ν2 (AsO4)3− symmetric bending vibration (E) and to the ν4 bending vibration (F2). The observation of multiple bending modes supports the concept of a reduction in symmetry of the arsenate anion in philipsbornite. Evidence for phosphate in the mineral is provided. By using an empirical formula, hydrogen bond distances for the OH units in philipsbornite of 2.8648 Å, 2.7864 Å, 2.6896 Å cm−1 and 2.6220 were calculated.

A vibrational spectroscopic study of the phosphate mineral zanazziite - Ca2(MgFe2+)(MgFe2+Al)4Be4(PO4)6⋅6(H2O)

Zanazziite is the magnesium member of a complex beryllium calcium phosphate mineral group named roscherite. The studied samples were collected from the Ponte do Piauí mine, located in Itinga, Minas Gerais. The mineral was studied by electron microprobe, Raman and infrared spectroscopy. The chemical formula can be expressed as Ca2.00(Mg3.15,Fe0.78,Mn0.16,Zn0.01,Al0.26,Ca0.14)Be4.00(PO4)6.09(OH)4.00⋅5.69(H2O) and shows an intermediate member of the zanazziite–greinfeinstenite series, with predominance of zanazziite member. The molecular structure of the mineral zanazziite has been determined using a combination of Raman and infrared spectroscopy. A very intense Raman band at 970 cm−1 is assigned to the phosphate symmetric stretching mode whilst the Raman bands at 1007, 1047, 1064 and 1096 cm−1 are attributed to the phosphate antisymmetric stretching mode. The infrared spectrum is broad and the antisymmetric stretching bands are prominent. Raman bands at 559, 568, 589 cm−1 are assigned to the ν4 out of plane bending modes of the PO4 and HPO4 units. The observation of multiple bands supports the concept that the symmetry of the phosphate unit in the zanazziite structure is reduced in symmetry. Raman bands at 3437 and 3447 cm−1 are attributed to the OH stretching vibrations; Raman bands at 3098 and 3256 are attributed to water stretching vibrations. The width and complexity of the infrared spectral profile in contrast to the well resolved Raman spectra, proves that the pegmatitic phosphates are better studied with Raman spectroscopy.

The molecular structure of matioliite – NaMgAl5(PO4)4(OH)6·2(H2O) : a pegmatite mineral from Minas Gerais, Brazil

Detailed spectroscopic and chemical investigation of matioliite, including infrared and Raman spectroscopy, scanning electron microscopy and electron probe microanalysis has been carried out on homogeneous samples from the Gentil pegmatite, Mendes Pimentel, Minas Gerais, Brazil. The chemical composition is (wt.%): FeO 2.20, CaO 0.05, Na2O 1.28, MnO 0.06, Al2O3 39.82, P2O5 42.7, MgO 4.68, F 0.02 and H2O 9.19; total 100.00. The mineral crystallize in the monoclinic crystal system, C2/c space group, with a = 25.075(1) Å, b = 5.0470(3) Å, c = 13.4370(7) Å, β = 110.97(3)°, V = 1587.9(4) Å3, Z = 4. Raman spectroscopy coupled with infrared spectroscopy supports the concept of phosphate, hydrogen phosphate and dihydrogen phosphate units in the structure of matioliite. Infrared and Raman bands attributed to water and hydroxyl stretching modes are identified. Vibrational spectroscopy adds useful information to the molecular structure of matioliite.

Developing intercultural competence in pre-service teachers from Australia and Malaysia : insights from the “Patches” programme

Developing intercultural competence in pre-service teachers from Australia and Malaysia: Insights from a Patches program. Innovative pedagogies can offer pre-service teachers the opportunity to develop their intercultural competence and take up more globalised viewpoints. One such innovation is the Patches program which brought together Malaysian and Australian pre-service teachers who were studying at the same university in Brisbane, Australia, to actively explore issues of cultural and linguistic difference. The participants were 14 Australian fourth-year pre-service teachers who were enrolled in a program on inclusive education, and 58 Malaysian pre-service teachers who had recently arrived at the university in Brisbane to commence their second year of an international education program. In peer groupings, these domestic and international pre-service teachers engaged in a series of interactive tasks and reflective writing workshops exploring intercultural experiences, over a period of ten weeks. Each element or ‘patch’ in the program was designed to build up into a mosaic of intercultural learning. The flexible structuring of the Patches Program provided a supportive framework for participant interaction whilst allowing the groups to decide for themselves the nature and extent of their involvement in a series of community-related tasks. The process of negotiating and implementing these activities formed the basis for establishing meaningful relationships between the participants. The development of the participants’ intercultural competence is traced through their reflective narratives and focus group discussions, drawing on Byram’s concept of the five savoirs. Explaining aspects of Australian culture to their newly arrived Malaysian peers, allowed the Australian pre-service teachers to take a perspective of outsideness towards their own familiar social practices. In addition, being unusually positioned as the linguistic other amongst a group of Bahasa Melayu speakers, highlighted for the Australian pre-service teachers the importance of being inclusive. For the Malaysian pre-service teachers, participation in the Patches program helped to extend intercultural understandings, establish social networks with local students, and build a sense of community in their new learning environment. Both groups of pre-service teachers noted the power of “learning directly by interacting rather than through books”. In addition to interacting interculturally, the process of reflecting on these intercultural experiences is seen as integral to the development of intercultural competence.

Transnational field experience : making the familiar strange

This study explores the impact of field experience in Australian primary classrooms on the developing professional identities of Malaysian pre-service teachers. This group of 24 Malaysian students are undertaking their Bachelor of Education in Teaching English as a Foreign Language (BEd TESL) at an Australian university, as part of a transnational twinning program. The globalisation of education has seen an increase in such transnational school experiences for pre-service teachers, with the aim of extending professional experience and intercultural competence by engaging in communities of practice beyond the local (Tsui 2005, Luke 2004). Despite overseas governments, such as Malaysia, having sponsored multimillion dollar twinning programs for their pre-service teachers, there is a lack of research regarding the outcomes of transnational professional practice within such programs. This study adopts a qualitative approach focusing on participants’ narratives as revealed in their reflective writing and through semi-structured interviews. Adopting a Bakhtinian framework, this research uses the concept of ‘voice’ to explore how pre-service teachers negotiate their identities as EFL teachers in response to their lived professional experiences (Bakhtin 1981, 1986). Encountering different cultural and educational practices in their transnational field experiences can lead pre-service teachers to question taken-for-granted practices that they have grown up with. This has been described as a process of making the familiar strange, and can lead to a shift in professional understandings. This study investigates how such questioning occurs and how the transnational field experience is perceived by the participants as contributing to their developing professional identities.

Parent and adolescent perceptions of family functioning : a comparison of clinic and non-clinic families

In this paper two studies are reported which compare (a) the perceptions of family functioning held by clinic and non-clinic adolescents, and (b) the perceptions of family functioning held by adolescents and their mothers in clinic and non-clinic families. In Study 1, matched group of clinic and non-clinic adolescents were compared on their responses to a 30-item scale (ICPS) designed to measure three factors of family functioning: Intimacy (high vs. low), Parenting Style (democratic vs. controlled) and Conflict (high vs. low). Clinic and non-clinic adolescents were also compared on their responses to a multi-dimensional measure of adolescent self-concept. Although there was little difference between the two groups of adolescents in terms of their perceptions of family functioning, there were strong relationships between the self-concept variables and the family functioning variables. In Study 2, comparisons were made between the perceptions of family functioning held by mothers and adolescents for both clinical and non-clinic families. There were no differences between the two groups of adolescents in terms of their perceptions of family functioning, although there were clear differences between the two groups of mothers. In addition, clinic adolescents and their mothers did not differ in their perceptions of the family, whereas adolescents in the non-clinic group saw their families significantly as less intimate and more conflicted than did their mothers.

An evaluation of corpus-driven measures of medical concept similarity for information retrieval

Measures of semantic similarity between medical concepts are central to a number of techniques in medical informatics, including query expansion in medical information retrieval. Previous work has mainly considered thesaurus-based path measures of semantic similarity and has not compared different corpus-driven approaches in depth. We evaluate the effectiveness of eight common corpus-driven measures in capturing semantic relatedness and compare these against human judged concept pairs assessed by medical professionals. Our results show that certain corpus-driven measures correlate strongly (approx 0.8) with human judgements. An important finding is that performance was significantly affected by the choice of corpus used in priming the measure, i.e., used as evidence from which corpus-driven similarities are drawn. This paper provides guidelines for the implementation of semantic similarity measures for medical informatics and concludes with implications for medical information retrieval.