Adapting to concurrent expert evidence in medical litigation

In medical negligence litigation expert evidence has long played a dominant role. The trend towards the use of concurrent expert evidence is now well underway. However, for the lawyers and the doctors involved, the pathway is not yet familiar. Disputes have frequently arisen in the context of pre-hearing expert conclaves, given the adversarial nature of litigation and perhaps fuelled by fears of a less transparent process at this increasingly important stage. This article explains the concurrent expert evidence framework and examines areas of common dispute both in the conclaves and at trial, with a view to providing assistance to legal practitioners working in this area and the medical practitioners called upon to provide expert evidence in such litigation.

Community engagement or community conversation?: Boomtown, a large-scale regional, outdoor community theatrical event

On the 18th of July 2013, three hundred local members of Gladstone, Queensland erupted into song and dance performing the fraught history of their community harbourside through tug boat ballets, taiko drumming, German bell ringing and BMX bike riding. Over 17,500 people attended the four performances of Boomtown, a Queensland Music Festival event. This was the largest regional, outdoor community-engaged musical performance staged in Australia. The narrative moved beyond the dominant, pejorative view of Gladstone as an industrial town to include the community members’ sense of purpose and aspirations. It was a celebratory, contentious and ambitious project that sought to disrupt the traditional conventions of performance-making through working in artistically democratic ways. This article explores the potential for Australian Community Engaged Arts (CEA) projects such as Boomtown to democratically engage community members and co-create culturally meaningful work within a community. Research into CEA projects rarely consider how the often delicate conversations between practitioners and the community work. The complex processes of finding and co-writing the narrative, casting, and rehearsing Boomtown are discussed with reference to artistic director/dramaturge Sean Mee’s innovative approaches. Boomtown began with and concluded with community conversations. Skilful negotiation ensured congruence between the townspeople’s stories and the “community story” presented on stage, abrogating potential problems of narrative ownership. To supplement the research, twenty-one personal interviews were undertaken with Gladstone community members invested in the production before, during and after the project: performers, audience members and local professionals. The stories shared and emphasised in the theatricalised story were based on propitious, meaningful, local stories from lived experiences rather than preconceived, trivial or tokenistic matters, and were underpinned by a consensus formed on what was in the best interests of the majority of community members. Boomtown exposed hidden issues in the community and gave voice to thoughts, feelings and concerns which triggered not just engagement, but honest conversation within the community.

Perubahan bahasa dalam perspektif Pre neogrammarian dan Neogrammarian dan Pengajaran bahasa dalam konteks EFL (Pre-Neogrammarian and Neogrammarians’ language change and English language pedagogy in EFL contexts)

This article describes different perspectives in response to language change, and aligns the perspectives of language change to English language pedagogy in non-English speaking contexts. The Pre-Neogrammarian and Neo-grammarian linguists that believe the change leads to respectively language decay or language existence will be outlined. This article suggests that the theories derived from both perspectives can be applied to any language. Once there is cultural contact between languages, the dominant language tends to suppress the non-dominant language. Hence, besides focusing on changes that happen in English and the effects of the changes into this language, this article also considers that other language—in this case EFL teachers’ “local language”—experiences an adverse change as the result of the speakers’ interaction with English. Then, this article also describes how the changes might lead to EFL teachers’ adaptation in their practice and cause teachers’ dilemmas.

Becoming bilingual: Children’s insights about making friends in bilingual settings

The majority of the world speaks more than one language yet the impact of learning a second language has rarely been studied from a child’s perspective. This paper describes monolingual children’s insights into becoming bilingual at four time points: two months before moving to another country (while living in Australia), as well as one, six, and twelve months after moving to Germany. The participants were two monolingual English-speaking siblings (a male aged 7- to 8-years and a female aged 9- to 10-years) who subsequently learned to speak German. At each of the four time points, interviews were undertaken with each child using child-friendly drawing and questionnaire techniques. Three themes were identified: (1) the children’s awareness of language competence; (2) inclusion factors, and; (3) exclusion factors that influenced friendship formation. The impact of language ability on making friends was a dominant theme that arose across the four time points and was triangulated across data collection methods. The children made friends with others who had similar language competence in German, even though they were younger, and did not share the same first language. Age-matched peers who were more competent in German were less likely to be described as friends. Across all three themes, the playground was highlighted by both children as the key site where becoming bilingual most strongly impacted initiation and negotiation of friendships. Becoming bilingual impacted the children’s friendship formation and socialization opportunities with more competent language users.

Technological adoption and use after mass market displacement: The case of the LP record

This paper investigates the reasons why some technologies, defying general expectations and the established models of technological change, may not disappear from the market after having been displaced from their once-dominant status. Our point of departure is that the established models of technological change are not suitable to explain this as they predominantly focus on technological dominance, giving attention to the technologies that display highest performance levels and gain greatest market share. And yet, technological landscapes are rife with technological designs that do not fulfil these conditions. Using the LP record as an empirical case, we propose that the central mechanism at play in the continuing market presence of once-dominant technologies is the recasting of their technological features from the functional-utilitarian to the aesthetic realm, with an additional element concerning communal interaction among users. The findings that emerge from our quantitative textual analysis of over 200,000 posts on a prominent online LP-related discussion forum (between 2002 and 2010) also suggest that the post-dominance technology adopters and users appear to share many key characteristics with the earliest adopters of new technologies, rather than with late-stage adopters which precede them.

Substrate effects in the supramolecular assembly of 1,3,5-benzene tricarboxylic acid on graphite and graphene

The behavior of small molecules on a surface depends critically on both molecule–substrate and intermolecular interactions. We present here a detailed comparative investigation of 1,3,5-benzene tricarboxylic acid (trimesic acid, TMA) on two different surfaces: highly oriented pyrolytic graphite (HOPG) and single-layer graphene (SLG) grown on a polycrystalline Cu foil. On the basis of high-resolution scanning tunnelling microscopy (STM) images, we show that the epitaxy matrix for the hexagonal TMA chicken wire phase is identical on these two surfaces, and, using density functional theory (DFT) with a non-local van der Waals correlation contribution, we identify the most energetically favorable adsorption geometries. Simulated STM images based on these calculations suggest that the TMA lattice can stably adsorb on sites other than those identified to maximize binding interactions with the substrate. This is consistent with our net energy calculations that suggest that intermolecular interactions (TMA–TMA dimer bonding) are dominant over TMA–substrate interactions in stabilizing the system. STM images demonstrate the robustness of the TMA films on SLG, where the molecular network extends across the variable topography of the SLG substrates and remains intact after rinsing and drying the films. These results help to elucidate molecular behavior on SLG and suggest significant similarities between adsorption on HOPG and SLG.

Mapping the regional influence of genetics on brain structure variability - A Tensor-Based Morphometry study

Genetic and environmental factors influence brain structure and function profoundly. The search for heritable anatomical features and their influencing genes would be accelerated with detailed 3D maps showing the degree to which brain morphometry is genetically determined. As part of an MRI study that will scan 1150 twins, we applied Tensor-Based Morphometry to compute morphometric differences in 23 pairs of identical twins and 23 pairs of same-sex fraternal twins (mean age: 23.8 ± 1.8 SD years). All 92 twins' 3D brain MRI scans were nonlinearly registered to a common space using a Riemannian fluid-based warping approach to compute volumetric differences across subjects. A multi-template method was used to improve volume quantification. Vector fields driving each subject's anatomy onto the common template were analyzed to create maps of local volumetric excesses and deficits relative to the standard template. Using a new structural equation modeling method, we computed the voxelwise proportion of variance in volumes attributable to additive (A) or dominant (D) genetic factors versus shared environmental (C) or unique environmental factors (E). The method was also applied to various anatomical regions of interest (ROIs). As hypothesized, the overall volumes of the brain, basal ganglia, thalamus, and each lobe were under strong genetic control; local white matter volumes were mostly controlled by common environment. After adjusting for individual differences in overall brain scale, genetic influences were still relatively high in the corpus callosum and in early-maturing brain regions such as the occipital lobes, while environmental influences were greater in frontal brain regions that have a more protracted maturational time-course.

Neural correlates of semantic priming for ambiguous words: An event-related fMRI study

We investigated the neural correlates of semantic priming by using event-related fMRI to record blood oxygen level dependent (BOLD) responses while participants performed speeded lexical decisions (word/nonword) on visually presented related versus unrelated prime-target pairs. A long stimulus onset asynchrony of 1000 ms was employed, which allowed for increased controlled processing and selective frequency-based ambiguity priming. Conditions included an ambiguous word prime (e.g. bank) and a target related to its dominant (e.g. money) or subordinate meaning (e.g. river). Compared to an unrelated condition, primed dominant targets were associated with increased activity in the LIFG, the right anterior cingulate and superior temporal gyrus, suggesting postlexical semantic integrative mechanisms, while increased right supramarginal activity for the unrelated condition was consistent with expectancy based priming. Subordinate targets were not primed and were associated with reduced activity primarily in occipitotemporal regions associated with word recognition, which may be consistent with frequency-based meaning suppression. These findings provide new insights into the neural substrates of semantic priming and the functional-anatomic correlates of lexical ambiguity suppression mechanisms.

Brain activity during automatic semantic priming revealed by event-related functional magnetic resonance imaging

Semantic priming occurs when a subject is faster in recognising a target word when it is preceded by a related word compared to an unrelated word. The effect is attributed to automatic or controlled processing mechanisms elicited by short or long interstimulus intervals (ISIs) between primes and targets. We employed event-related functional magnetic resonance imaging (fMRI) to investigate blood oxygen level dependent (BOLD) responses associated with automatic semantic priming using an experimental design identical to that used in standard behavioural priming tasks. Prime-target semantic strength was manipulated by using lexical ambiguity primes (e.g., bank) and target words related to dominant or subordinate meaning of the ambiguity. Subjects made speeded lexical decisions (word/nonword) on dominant related, subordinate related, and unrelated word pairs presented randomly with a short ISI. The major finding was a pattern of reduced activity in middle temporal and inferior prefrontal regions for dominant versus unrelated and subordinate versus unrelated comparisons, respectively. These findings are consistent with both a dual process model of semantic priming and recent repetition priming data that suggest that reductions in BOLD responses represent neural priming associated with automatic semantic activation and implicate the left middle temporal cortex and inferior prefrontal cortex in more automatic aspects of semantic processing.

Dopaminergic neuromodulation of semantic processing: A 4-T fMRI study with levodopa

There is emerging evidence that alterations in dopaminergic transmission can influence semantic processing, yet the neural mechanisms involved are unknown. The influence of levodopa (L-DOPA) on semantic priming was investigated in healthy individuals (n=20) using event-related functional magnetic resonance imaging with a randomized, double-blind crossover design. Critical prime-target pairs consisted of a lexical ambiguity prime and 1) a target related to the dominant meaning of the prime (e.g., bank-money), 2) a target related to the subordinate meaning (e.g., fence-sword), or 3) an unrelated target (e.g., ball-desk). Behavioral data showed that both dominant and subordinate meanings were primed on placebo. In contrast, there was preserved priming of dominant meanings and no significant priming of subordinate meanings on L-DOPA, the latter associated with decreased anterior cingulate and dorsal prefrontal cortex activity. Dominant meaning activation on L-DOPA was associated with increased activity in the left rolandic operculum and left middle temporal gyrus. These findings suggest that L-DOPA enhances frequency-based semantic focus via prefrontal and temporal modulation of automatic semantic priming and through engagement of anterior cingulate mechanisms supporting attentional/controlled priming.

Motor response suppression and the prepotent tendency to respond: A parametric fMRI study

In the present study we utilised functional magnetic resonance imaging (fMRI) to examine cerebral activation during performance of a classic motor task in which response suppression load was parametrically varied. Linear increases in activity were observed in a distributed network of regions across both cerebral hemispheres, although with more extensive involvement of the right prefrontal cortex. Activated regions included prefrontal, parietal and occipitotemporal cortices. Decreasing activation was similarly observed in a distributed network of regions. These response forms are discussed in terms of an increasing requirement for visual cue discrimination and suppression/selection of motor responses, and a decreasing probability of the occurrence of non-target stimuli and attenuation of a prepotent tendency to respond. The results support recent proposals for a dominant role for the right-hemisphere in performance of motor response suppression tasks that emphasise the importance of the right prefrontal cortex.

Probabilistic multi-tensor estimation using the tensor distribution function

Diffusion weighted magnetic resonance (MR) imaging is a powerful tool that can be employed to study white matter microstructure by examining the 3D displacement profile of water molecules in brain tissue. By applying diffusion-sensitized gradients along a minimum of 6 directions, second-order tensors can be computed to model dominant diffusion processes. However, conventional DTI is not sufficient to resolve crossing fiber tracts. Recently, a number of high-angular resolution schemes with greater than 6 gradient directions have been employed to address this issue. In this paper, we introduce the Tensor Distribution Function (TDF), a probability function defined on the space of symmetric positive definite matrices. Here, fiber crossing is modeled as an ensemble of Gaussian diffusion processes with weights specified by the TDF. Once this optimal TDF is determined, the diffusion orientation distribution function (ODF) can easily be computed by analytic integration of the resulting displacement probability function.

White matter integrity measured by fractional anisotropy correlates poorly with actual individual fiber anisotropy

Fractional anisotropy (FA), a very widely used measure of fiber integrity based on diffusion tensor imaging (DTI), is a problematic concept as it is influenced by several quantities including the number of dominant fiber directions within each voxel, each fiber's anisotropy, and partial volume effects from neighboring gray matter. High-angular resolution diffusion imaging (HARDI) can resolve more complex diffusion geometries than standard DTI, including fibers crossing or mixing. The tensor distribution function (TDF) can be used to reconstruct multiple underlying fibers per voxel, representing the diffusion profile as a probabilistic mixture of tensors. Here we found that DTIderived mean diffusivity (MD) correlates well with actual individual fiber MD, but DTI-derived FA correlates poorly with actual individual fiber anisotropy, and may be suboptimal when used to detect disease processes that affect myelination. Analysis of the TDFs revealed that almost 40% of voxels in the white matter had more than one dominant fiber present. To more accurately assess fiber integrity in these cases, we here propose the differential diffusivity (DD), which measures the average anisotropy based on all dominant directions in each voxel.

Discovery and replication of dopamine-related gene effects on caudate volume in young and elderly populations (N1198) using genome-wide search

The caudate is a subcortical brain structure implicated in many common neurological and psychiatric disorders. To identify specific genes associated with variations in caudate volume, structural magnetic resonance imaging and genome-wide genotypes were acquired from two large cohorts, the Alzheimer's Disease NeuroImaging Initiative (ADNI; N=734) and the Brisbane Adolescent/Young Adult Longitudinal Twin Study (BLTS; N=464). In a preliminary analysis of heritability, around 90% of the variation in caudate volume was due to genetic factors. We then conducted genome-wide association to find common variants that contribute to this relatively high heritability. Replicated genetic association was found for the right caudate volume at single-nucleotide polymorphism rs163030 in the ADNI discovery sample (P=2.36 × 10 -6) and in the BLTS replication sample (P=0.012). This genetic variation accounted for 2.79 and 1.61% of the trait variance, respectively. The peak of association was found in and around two genes, WDR41 and PDE8B, involved in dopamine signaling and development. In addition, a previously identified mutation in PDE8B causes a rare autosomal-dominant type of striatal degeneration. Searching across both samples offers a rigorous way to screen for genes consistently influencing brain structure at different stages of life. Variants identified here may be relevant to common disorders affecting the caudate.

A novel measure of fractional anisotropy based on the tensor distribution function

Fractional anisotropy (FA), a very widely used measure of fiber integrity based on diffusion tensor imaging (DTI), is a problematic concept as it is influenced by several quantities including the number of dominant fiber directions within each voxel, each fiber's anisotropy, and partial volume effects from neighboring gray matter. With High-angular resolution diffusion imaging (HARDI) and the tensor distribution function (TDF), one can reconstruct multiple underlying fibers per voxel and their individual anisotropy measures by representing the diffusion profile as a probabilistic mixture of tensors. We found that FA, when compared with TDF-derived anisotropy measures, correlates poorly with individual fiber anisotropy, and may sub-optimally detect disease processes that affect myelination. By contrast, mean diffusivity (MD) as defined in standard DTI appears to be more accurate. Overall, we argue that novel measures derived from the TDF approach may yield more sensitive and accurate information than DTI-derived measures.