Probabilistic subgroup identification using Bayesian finite mixture modelling : a case study in Parkinson’s disease phenotype identification

This article explores the use of probabilistic classification, namely finite mixture modelling, for identification of complex disease phenotypes, given cross-sectional data. In particular, if focuses on posterior probabilities of subgroup membership, a standard output of finite mixture modelling, and how the quantification of uncertainty in these probabilities can lead to more detailed analyses. Using a Bayesian approach, we describe two practical uses of this uncertainty: (i) as a means of describing a person’s membership to a single or multiple latent subgroups and (ii) as a means of describing identified subgroups by patient-centred covariates not included in model estimation. These proposed uses are demonstrated on a case study in Parkinson’s disease (PD), where latent subgroups are identified using multiple symptoms from the Unified Parkinson’s Disease Rating Scale (UPDRS).

Use of 3D visualisation to enhance groundwater stable isotope data and its interpretation, Lockyer Valley, southeast Queensland

The use of stable isotope ratios δ18O and δ2H are well established in assessment of groundwater systems and their hydrology. The conventional approach is based on x/y plots and relation to various MWL’s, and plots of either ratio against parameters such as Clor EC. An extension of interpretation is the use of 2D maps and contour plots, and 2D hydrogeological vertical sections. An enhancement of presentation and interpretation is the production of “isoscapes”, usually as 2.5D surface projections. We have applied groundwater isotopic data to a 3D visualisation, using the alluvial aquifer system of the Lockyer Valley. The 3D framework is produced in GVS (Groundwater Visualisation System). This format enables enhanced presentation by displaying the spatial relationships and allowing interpolation between “data points” i.e. borehole screened zones where groundwater enters. The relative variations in the δ18O and δ2H values are similar in these ambient temperature systems. However, δ2H better reflects hydrological processes, whereas δ18O also reflects aquifer/groundwater exchange reactions. The 3D model has the advantage that it displays borehole relations to spatial features, enabling isotopic ratios and their values to be associated with, for example, bedrock groundwater mixing, interaction between aquifers, relation to stream recharge, and to near-surface and return irrigation water evaporation. Some specific features are also shown, such as zones of leakage of deeper groundwater (in this case with a GAB signature). Variations in source of recharging water at a catchment scale can be displayed. Interpolation between bores is not always possible depending on numbers and spacing, and by elongate configuration of the alluvium. In these cases, the visualisation uses discs around the screens that can be manually expanded to test extent or intersections. Separate displays are used for each of δ18O and δ2H and colour coding for isotope values.

On the computation and interpretation of auto- and cross-trispectra

This paper discusses the principal domains of auto- and cross-trispectra. It is shown that the cumulant and moment based trispectra are identical except on certain planes in trifrequency space. If these planes are avoided, their principal domains can be derived by considering the regions of symmetry of the fourth order spectral moment. The fourth order averaged periodogram will then serve as an estimate for both cumulant and moment trispectra. Statistics of estimates of normalised trispectra or tricoherence are also discussed.

Desire in the winter’s pale : a hermeneutic interpretation of the experience of sexual desire in older age

The experience of sexual desire in older age remains an aspect of the ageing experience about which little is known; much less understood. To address this gap in knowledge, the purpose of this hermeneutic interpretive study was to describe and understand how sexual desire is experienced in a sample of 11 purposively selected men and six women aged between 62 and 92 years. The study was based on audio-taped interviews with participants who were willing to discuss their experiences of sexual desire. The study was guided by the philosophy of Paul Ricoeur through the process of interview transcription to the interpretation of the experience of sexual desire in older age. Participants’ narratives were analysed for emergent themes using a twofold methodology inspired by Ricoeur. The narratives provided first-hand accounts of the experience of sexual desire in an ageing context. Findings revealed that participants identified as a sexual being regardless of age and availability of sexual partner. Findings also revealed that sexual selfhood was acknowledged through physiological response, that sexual desire could be influenced by socio-cultural factors and experienced within an ethical relational domain. Major themes explicated during the study included the experience of health and wellbeing, experience of sexual response, experience of sexual inadequacy, being socialised and re-entering the social scene.

Optical and microscopic study of a polymer-nanotube mixture for organic photovoltaic applications

Organic solar cells based on bulk heterojunction between a conductive polymer and a carbon nanostructure offer potential advantages compared to conventional inorganic cells. Low cost, light weight, flexibility and high peak power per unit weight are all features that can be considered a reality for organic photovoltaics. Although polymer/carbon nanotubes solar cells have been proposed, only low power conversion efficiencies have been reached without addressing the mechanisms responsible for this poor performance. The purpose of this work is therefore to investigate the basic interaction between carbon nanotubes and poly(3-hexylthiophene) in order to demonstrate how this interaction affects the performance of photovoltaic devices. The outcomes of this study are the contributions made to the knowledge of the phenomena explaining the behaviour of electronic devices based on carbon nanotubes and poly(3-hexylthiophene). In this PhD, polymer thin films with the inclusion of uniformly distributed carbon nanotubes were deposited from solution and characterised. The bulk properties of the composites were studied with microscopy and spectroscopy techniques to provide evidence of higher degrees of polymer order when interacting with carbon nanotubes. Although bulk investigation techniques provided useful information about the interaction between the polymer and the nanotubes, clear evidence of the phenomena affecting the heterojunction formed between the two species was investigated at nanoscale. Identifying chirality-driven polymer assisted assembly on the carbon nanotube surface was one of the major achievements of this study. Moreover, the analysis of the electrical behaviour of the heterojunction between the polymer and the nanotube highlighted the charge transfer responsible for the low performance of photovoltaic devices. Polymer and carbon nanotube composite-based devices were fabricated and characterised in order to study their electronic properties. The carbon nanotube introduction in the polymer matrix evidenced a strong electrical conductivity enhancement but also a lower photoconductivity response. Moreover, the extension of pristine polymer device characterisation models to composites based devices evidenced the conduction mechanisms related to nanotubes. Finally, the introduction of carbon nanotubes in the polymer matrix was demonstrated to improve the pristine polymer solar cell performance and the spectral response even though the power conversion efficiency is still too low.

'The war of Canudos: a Euclidean interpretation.' [Guerra de Canudos: uma leitura euclidiana]

The publication of the book The interior, in 1902, would change the course of thinking about the War of Canudos, who for many years, had been known simply as' the history of Euclid. President Getulio Vargas became interested in the backwoods bloodbath after reading the book avenger-Euclidean. Liked the work he visited the place of occurrence of war promising enjoy the river poured-Barris with the construction of the weir Cocorobo. Euclides da Cunha lived and produced his work in a time of great change in thought, politics and technology. Despite having worked in the press throughout his life, was best known as an engineer, for having exercised the office during the reconstruction of the bridge, in Sao Jose do Rio Pardo. This article aims to illuminate the event of war in light of the Euclidean work. We will examine the trajectory of Euclides da Cunha in journalism. Your learning process to execute the office newsreader and war correspondent, the newspaper O Estado de S. Paul, as well as their reports and work-monument the hinterlands. Resumo: A publicação da obra Os sertões, em 1902, mudaria os rumos do pensamento sobre a Guerra de Canudos, que, por muitos anos, ficara conhecida, simplesmente, como ‘história de Euclides’. O presidente Getúlio Vargas interessou-se pela hecatombe sertaneja após ter lido o livro-vingador euclidiano. Gostou tanto da obra que visitou o lugar de acontecimento da guerra prometendo aproveitar as águas do rio Vaza-Barris com a construção do açude de Cocorobó. Euclides da Cunha viveu e produziu a sua obra em um momento de grandes transformações no pensamento, na política e na tecnologia. Apesar de ter atuado na imprensa ao longo de toda a sua vida, ficou mais conhecido como engenheiro, por ter exercido o ofício, durante a reconstrução da ponte, em São José do Rio Pardo. O presente artigo visa iluminar o acontecimento da guerra à luz da obra euclidiana. Examinaremos a trajetória de Euclides da Cunha no jornalismo. O seu processo de aprendizagem para exercer o ofício de noticiarista e correspondente de guerra, pelo jornal O Estado de S. Paulo, bem como, as suas reportagens e obra-monumento Os sertões.

An interpretation of current progress towards an industry model for Queensland's surveying and mapping industry

A strongly progressive surveying and mapping industry depends on a shared understanding of the industry as it exists, some shared vision or imagination of what the industry might become, and some shared action plan capable of bringing about a realisation of that vision. The emphasis on sharing implies a need for consensus reached through widespread discussion and mutual understanding. Unless this occurs, concerted action is unlikely. A more likely outcome is that industry representatives will negate each other's efforts in their separate bids for progress. The process of bringing about consensual viewpoints is essentially one of establishing an industry identity. Establishing the industry's identity and purpose is a prerequisite for rational development of the industry's education and training, its promotion and marketing, and operational research that can deal .with industry potential and efficiency. This paper interprets evolutionary developments occurring within Queensland's surveying and mapping industry within a framework that sets out logical requirements for a viable industry.

Dirichlet process mixture models for unsupervised clustering of symptoms in Parkinson's disease

In this paper, the goal of identifying disease subgroups based on differences in observed symptom profile is considered. Commonly referred to as phenotype identification, solutions to this task often involve the application of unsupervised clustering techniques. In this paper, we investigate the application of a Dirichlet Process mixture (DPM) model for this task. This model is defined by the placement of the Dirichlet Process (DP) on the unknown components of a mixture model, allowing for the expression of uncertainty about the partitioning of observed data into homogeneous subgroups. To exemplify this approach, an application to phenotype identification in Parkinson’s disease (PD) is considered, with symptom profiles collected using the Unified Parkinson’s Disease Rating Scale (UPDRS). Clustering, Dirichlet Process mixture, Parkinson’s disease, UPDRS.

Pedagogy and paradox : teaching interpretation in a religious community

A qualitative, discourse analytic study of literate practices in a small religious community in a northern Australian city. The chapter documents how this community constructs religious reading and writing, affiliated ideologies and theologies, and how readers/hearers/learners are positions vis a vis the authority of sacred text.

A phenomenological study of dream interpretation among the Xhosa-speaking people in rural South Africa

Psychologists investigating dreams in non-Western cultures have generally not considered the meanings of dreams within the unique meaning-structure of the person in his or her societal context. The study was concerned with explicating the indigenous system of dream interpretation of the Xhosa-speaking people, as revealed by acknowledged dream experts, and elaborating upon the life-world of the participants. Fifty dreams and their interpretations were collected from participants, who were traditional healers and their clients. A phenomenological methodology was adopted in explicating the data. Themes explicated included : the physiognomy of the dreamer's life-world as revealed by significant dreams, the interpretation of significant dreams as revealed through action, and human bodiliness as revealed in dream interpretations. The participants' approach to dreams is not based upon an explicit theory, but upon an immediate and pathic understanding of the dream phenomenon. The understanding is based upon the interpreter's concrete understanding of the life-world, which includes the possibility of cosmic integration and continuity between personal and trans-personal realms of being