Minerva Elements Records
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Characterization of new regulators in TNFR1-mediated death signalling
Tumor necrosis factor (TNF) is a master inflammatory cytokine that can, depending on the circumstances, promote survival and proliferation or induce cell death. Anti-TNF drugs have proven strikingly successful in treating inflammatory diseases such as rheumatoid arthritis (RA), psoriasis and inflammatory bowel disease (IBD) but it is still unclear exactly why. For a long time, it was thought that they work solely by preventing TNF induced transcription of other inflammatory cytokines, but more recently it has been proposed that one of their major anti-inflammatory functions is to prevent TNF induced death. Therefore, understanding the mechanism by which TNF induced death is regulated may enable the conceptualization of newer or improved approaches in treating a variety of inflammation-associated pathologies. Binding of TNF to its receptor TNFR1 leads to the formation of two distinct signalling complexes. While most previous studies have focused on the membrane-bound, transcription-activating complex (complex-1), the composition and post-translational modifications of the cytosolic, caspase-8-containing, death-inducing complex (complex-2) remain far less well defined. To analyse TNFR1 complex-2 composition at endogenous levels, we decided to generate FLAG tagged caspase-8 knock-in mouse strains. The reagents for the FLAG tag enable very efficient and specific purification and identification of a FLAG tagged protein and its partners. After some preliminary tests and trials, I decided to use a 3x FLAG tag which has been reported to be 20–200 times more sensitive than other FLAG tags in immunoprecipitation and detection assays. Before generating the mouse strains, in Chapter 3 I performed extensive in vitro comparison of N-terminally or C-terminally 3x FLAG-tagged caspase-8 using a doxycycline (Dox)-inducible stably integrated lentiviral system. The results suggested that when expressed above endogenous levels, the expression and killing activity of caspase-8 was unaffected by a 3x FLAG tag. Interestingly, when expressed at physiological levels, C-terminally 3x FLAG tagged caspase-8 appeared to be equivalent to untagged caspase-8 and marginally more efficient in mediating TNF-induced death and complex-2 formation compared to N-terminally 3x FLAG tagged caspase-8. In addition, I immunoprecipitated TNFR1 complex-2 from cells expressing endogenous levels of 3x FLAG tagged caspase-8 and performed a mass spectrometry (MS) analysis. According to this analysis, Tankyrase-1 (TNKS1/PARP5a/ ARTD5), a member of the poly ADP-ribose polymerase (PARP) superfamily, appears to be a novel interactor of complex-2. Based on our in vitro data, we generated N-terminally or C-terminally 3x FLAG tagged caspase-8 knock-in mice using CRIPSR/Cas9 technology and these mice were characterized in Chapter 4. Homozygous N-terminally or C-terminally 3x FLAG tagged caspase-8 knock-in mice were viable, fertile and developed normally, indicating that N-terminally or C-terminally 3x FLAG tagged caspase-8 were expressed and active in vivo, at least to heterozygous caspase-8 levels. As expected, the expression of N-terminal or C-terminal 3x FLAG tagged caspase-8 was detectable in tissue and cells from knock-in mice by Western blot and immunofluorescence stain using an anti-FLAG M2 antibody. The 3x FLAG tagged caspase-8 displayed similar tissue distribution and comparable expression levels as endogenous caspase-8. The cell death assay suggested that the primary cells and transformed cells from 3x FLAG tagged caspase-8 knock-in mice responded similarly as wild-type cells to apoptotic and necroptotic stimulations. Moreover, by performing anti-FLAG immunoprecipitation, I successfully purified endogenous TNFR1 complex-2 from knock-in mice derived cells. These data indicated that 3x FLAG tagged caspase-8 knock-in mouse strains are useful tools to study caspase-8 and caspase-8-containing protein complexes at physiological levels. In Chapter 5, I characterized tankyrases-mediated poly(ADP-ribosyl)ation (PARsylation) as a novel checkpoint that limits TNF-induced cytotoxicity. Using primary cells from the 3x FLAG tagged caspase-8 knock-in mice described in Chapter 4, I found that the enzyme tankyrase-1 (TNKS1/TNKS/PARP5a/ARTD5), which was identified by mass spectrometry in Chapter 3, is recruited to the endogenous TNFR1 complex-2. Western blot data indicates that tankyrase-2 (TNKS2/PARP5b/ARTD6) may also be recruited. Tankyrases are poly ADP-ribose polymerases and belong to an ancient group of enzymes that post-translationally modify proteins with ADP-ribose. I found that during TNF signalling, complex-2 becomes poly(ADP-ribosyl)ated (PARsylated) in a tankyrases-dependent manner. Furthermore, tankyrases-specific inhibitors sensitized cells to TNF-induced cell death, which correlated with increased levels of complex-2. This suggested that normally tankyrases help limit TNF induced death. Mechanistically, I showed that tankyrases may modulate the stability of complex-2 by recruiting the E3 ubiquitin ligase RNF146, that in turn promotes ubiquitylation and degradation of complex-2. Moreover, inactivation of tankyrases dramatically increased the killing of the clinical Smac-mimetic (SM) birinapant in a primary acute myeloid leukemia (AML) model. Taken together, this thesis describes 3x FLAG tagged caspase-8 knock-in mice as new tools to study caspase-8 and caspase-8-containing protein complexes at physiological levels. Furthermore, this study identifies tankyrases-mediated PARsylation as a novel checkpoint in TNF signalling that expands our understanding of how TNF induced death is regulated and provides a rationale to use tankyrases inhibitors for cancer therapy.
Seasonality and community composition of parasitoid wasps of four agromyzid leafminer species (Diptera: Agromyzidae) in Victoria
The vegetable leafminer, Liriomyza sativae Blanchard (Diptera: Agromyzidae), was first detected in the Torres Straits in 2008, crossed over to the tip of Cape York in 2015 and now poses a threat to Australian crops. This species is an economically important secondary pest in many parts of the world; populations readily evolve resistance to insecticides and benefit from the use of chemical controls against other pests, which kill their natural enemies. Liriomyza sativae is expected to spread into Australia’s agricultural production areas and it is therefore valuable to investigate the local biological agents that could contribute to future integrated pest management (IPM). I assessed the abundance and diversity of the hymenopteran parasitoid wasps of four common agromyzid flies in southern Victoria (Liriomyza brassicae (Riley), Liriomyza chenopodii (Watt), Phytomyza plantaginis Goureau, and Phytomyza syngenesiae (Hardy)) to evaluate their potential as candidates for control of L. sativae. I monitored six sites in Melbourne over a period of 18 months by collecting mined leaves from a range of plant species and rearing adult flies and their parasitoids. Additional sites around Victoria were also sampled to offer a snapshot of the agromyzid presence across the state. Eleven wasp species were identified in total, two of which were only classified to morphospecies level, including known parasitoids of L. sativae overseas and species reared from L. sativae populations from far north Queensland. Ninety percent of the parasitoids were eulophids (Hymenoptera: Eulophidae), with the rest consisting of opiines (Braconidae) and Pteromalinae (Pteromalidae). The adventive Chrysocharis pubicornis (Zetterstedt) was the most abundant parasitoid, reared almost entirely from Phytomyza hosts, followed by an Asecodes sp. and the introduced Diglyphus isaea (Walker). We recorded the first male Ph. plantaginis for Australia. Males were only found at Melbourne locations and these populations tended to have a female-biased sex ratio. Variation in sex ratio may be host plant dependent, as the female:male ratio was 4:1 from the host Plantago lanceolata L. while it was 1:1 in more limited samples from Plantago major L. The four common local agromyzids reached peak abundance at different times of the year and together supported a stable community of both adventive and native parasitoids. Of the species reared, several are known to attack L. sativae including D. isaea, Hemiptarsenus varicornis (Girault) and Neochrysocharis formosa (Westwood). The wasps reared include candidates for augmentative or conservation biological control that should be further considered in the event that L. sativae becomes a widespread pest of Australian crops.
Modeling the Distribution of a Widely Distributed butVulnerable Marsupial: Where and How to Fit Useful Models?
The greater glider (Petauroides volans) is the largest of the Australian gliding marsupials. Once abundant, it is now nationally listed as vulnerable because evidence of population decline exists across its distributional range. This decline and its likely relation with wildfire and logging, has prompted focus on conservation of this species. Species Distribution Models (SDMs) relate species occurrences to environmental variables at observation sites to predict distributions or make inferences about their key drivers. Conservation planning and land management use SDMs to deliver predictions of species distributions across landscapes. When modelling a broadly distributed species like the greater glider, data are often gathered from sources that vary in quality. In such cases, accounting for sampling biases and selection of geographic extent for model fitting are two key methodological steps that can largely influence models results. In this thesis I tested the effect of taking alternative decisions regarding occurrence data processing, modelling method and geographic extent on models’ predictive performance and how different decisions might (or not) provide different information for conservation and land management actions in a region subject to commercial logging. In the first research chapter, I tested different methods for dealing with sampling biases when modelling the distribution of the greater glider across its entire range. I compiled a dataset of occurrence data of the greater glider and other arboreal marsupials and tested alternative ways to use this large but biased dataset. I used modelling methods that utilize different types of occurrence data, namely, presence-background and presence-absence methods. I found that using presence-absence models fitted to an expanded presence-absence dataset in which some data were inferred provided the best performing models. In the second research chapter, I compared range-wide and local SDMs to predict the distribution of the greater glider in East Gippsland, Victoria. I found that two models: a range-wide one, and a local model fitted with higher quality variables, were the best performing. Models delivered somewhat different spatial predictions but broadly agreed on the largest patches of high predicted probability and gave similar estimates of the proportion of habitat across different land uses in the East Gippsland Regional Forest Agreement. I also completed a preliminary assessment of the extent of greater glider habitat burnt during the 2019-2020 wildfires that affected eastern Australia. I found that a large proportion of habitat was affected, including recently established protected areas. Throughout this thesis I show that decisions regarding data processing, selection of modelling method and geographic extent can lead to substantially different distribution predictions. In a context of local conservation planning such as the East Gippsland Regional Forest Agreement, different models, nevertheless, provided similar information on the implications that forest management and logging restrictions may have on the conservation of greater glider habitat in this region. Although the solutions we implemented relied on the broad availability of biodiversity data in Australia, we advocate for modellers and users to undertake thorough assessments of the data available in their regions and think carefully on how to make the best use of it.
Persisting Tensions: The Framing of International Legal Debates on Foreign Fighting
The issue of foreign fighting is approached today within a predominant framing of counterterrorism and security. Yet, international legal debate over the twentieth century to today demonstrates a grappling with richer debates and histories surrounding private individuals participating in “other people’s wars”. By carefully considering the alternative framings and international legal responses surrounding a broader range of foreign fighting, this thesis reveals the powers and limits of the present counterterrorism framing of foreign fighter issues. Not only has a counterterrorism approach proven problematic in its operation, but the continued participation in warfare of foreign fighters of different categories and persuasions means that a framing focusing solely on counterterrorism risks over-extension or reaches limits in terms of providing satisfactory responses to broader questions surrounding foreign fighting. This thesis argues that those working with international law are not limited to a counterterrorism framing of foreign fighting; that there is a richer repertoire of possible argument available within international law than may at first be appreciated. This argument is made by stepping back to consider three selected moments of foreign fighter regulation between 1907–2014, namely, neutrality law and the response to foreign volunteer fighters during the Spanish Civil War, the definition and attempted criminalisation of mercenaries following the conflicts linked to decolonisation, and the Security Council’s 2014 definition of foreign terrorist fighter. This study demonstrates how in each setting, legal debate, assessment of the key issues at stake, and resultant determinations took place within a powerful predominant legal framing of the foreign fighter issue, affecting the scope and focus of legal argumentation: neutrality and abstention at the beginning of the century, self-determination during decolonisation, and counterterrorism in the twenty-first century. At the same time, the thesis makes visible how red threads of debate surrounding foreign fighting reoccur across time and setting, and continue to resonate today. These include questions about the public and private, about foreignness, about ideological motivations and the commercialisation of force, about groups and individuals, abstention and intervention, harm and required levels of diligence. What emerges from this project is a view of both the change and the stasis in international law surrounding foreign fighting: changes, such as legal determinations made within alternative framings in different moments and the resultant definitions of categories of foreign fighters, and tensions — red threads — that persist throughout the debates. The tensions are always there but are argued and settled differently in different situations in line with the dominant framing of the moment. This thesis suggests the complementary explanatory power offered by paying attention to the operation of the counterterrorism framing; what it allows and what it obscures, and by thinking more generously and creatively about the shape of debates across different phenomena of foreign fighting, and, thus, the concerns and values beyond terrorism upon which determinations about foreign fighting could be based.
Multi-objective optimisation of a prefabricated house in Australian climate zones
Quantitative evaluations of indoor environmental quality (IEQ) along with energy efficiency are amongst the key features of environmentally sustainable buildings. Buildings are responsible for a significant portion (nearly 40%) of the world’s total energy consumption and GHG emissions. On the other hand, operational phase contributes to the greater part of the building’s energy consumption. Along with energy efficiency, IEQ is another aspect that has been attracting significant attention in the field of sustainable building design. People spend about 90% of their time indoors. Therefore, the comfort levels and satisfaction of indoor environment can easily affect the quality of their daily life. The IEQ parameters considered in this thesis include thermal comfort, visual comfort, auditory comfort and indoor air quality (IAQ). While prefabrication offers substantial benefits to the construction industry through quality assurance, time savings and waste reduction, it tends to transform the construction process and components which can affect the buildings’ performance in both positive and negative ways. Understanding the effects of the prefabricated building components on energy performance and IEQ will inform the design decisions which can lead to the creation of more sustainable buildings with high quality. Although previous research has focused on the benefits and limitations of prefabrication in housing, there has been little quantitative analysis on how various envelope components may affect several performance parameters including energy consumption and IEQ of residential buildings. Along with that, there is still a lack of systematic design methods and decision support which can lead to design solutions to improve both sustainability and affordability aspects. These issues constitute the main knowledge gaps, leading to the identification of the research aim as: ‘The aim of this thesis is to optimise the envelope components of a prefabricated house to minimise thermal discomfort hours (TDH), daylight unsatisfied hours (DUH) and life cycle costs (LCC) while meeting the requirement of Australian National Construction Code (NCC) on energy efficiency and IEQ performance’. The focus of this study is on a prefabricated house in various Australian climates. Building performance optimisations with multi-objectives in early stages of design have been conducted to minimise LCC while maintaining the satisfactory indoor environment. A framework was developed to conduct multi-objective optimisation of a selected residential building. The framework is the structure developed for conducting multi-objective optimisation in early design stages through a number of sequential rational steps. The steps include model development, model validation, sensitivity analysis, development of component’s library and multi-objective optimisation. As the result of optimisations, the optimal combinations of envelope components were presented in the form of Pareto optimal solutions. The optimal solutions achieved 27-31% savings in LCC compared to the baseline while the reductions for TDH varied between 6% and 55%. As a result of trade-offs, the selected compromised solutions in each climate could achieve better reductions for either TDH, LCC or both.The optimal solutions, as well as recommended best compromised solutions, provided useful insight and decision support towards the design solutions that minimise LCC while providing satisfactory indoor environment. The developed framework for building optimisation in early stages can be used by designers and building performance simulation practitioners across any types of buildings.
Sub-meter scale lithological heterogeneity and its influence on the CO2 trapping capacity in CO2 storage reservoirs
Lithological heterogeneity at mm- to cm-scale exists in the form of sedimentary structures such as cross bedding and planar bedding in heterogeneous siliciclastic reservoirs. At this scale, sedimentary structures typically consist of two lithologies with significant differences in their porosity, permeability, capillary entry pressure and mineral composition. The lithology with high porosity, high permeability, low capillary entry pressure and a high abundance of quartz and feldspar characterizes the reservoir rock and is conducive to fluid flow. On the other hand, the lithology with low porosity, low permeability, high capillary entry pressure and a high abundance of clay and carbonate minerals characterizes the intraformational baffle and acts as flow barrier. The presence of both lithologies at mm- to cm-scale govern local fluid flow and geochemical reactions. This is especially important in CO2 storage reservoirs where CO2 flow and mineralization might be significantly affected. Hence, it is necessary to account for lithological heterogeneity at sub-meter scale in regional scale dynamic simulations. However, intraformational baffles are typically neglected in static reservoir models primarily because small scale intraformational baffles are not commonly resolved by wireline logs. Therefore, their lithological properties are not accounted for in reservoir models. This study addresses the characterization and incorporation of intraformational baffles in reservoir models so that the reservoir scale estimation of carbon mineral trapping capacity can be improved. Firstly, rocks from the CO2CRC’s Otway Research Facility were characterised using a range of sample and data analysis methods. The variability in porosity, permeability, capillary entry pressure, grain size and mineral composition was used to classify five homogeneous rock type classes: coarse sandstone, fine sandstone, siltstone, mudstone and carbonate-cemented sandstone. A new workflow was developed where homogeneous rock types and composite rock types consisting of two lithologies characteristic of intraformational baffles were represented. Rock properties for composite rock types were derived so that mm-scale heterogeneity can be upscaled for integration in coarser discretised reservoir models. Lithotype logs of composite rock types were derived and used to build a high resolution 2D static reservoir model of the site. Multiphase fluid flow and reactive transport simulations were run on 120 and 8 realizations, respectively, to develop a detailed understanding of CO2 flow and geochemical reactions at mm-scale. It was found that the capillary entry pressure characteristic of the reservoir rock significantly governed the range of turning point saturations while the amount of clay and carbonate content of the baffle governed the amount of carbon mineralized. Reactive transport simulations were also run on two 2D reservoir models to quantify the error associated with the estimation of carbon mineral trapping at reservoir scales if intraformational baffles are not accounted for in dynamic simulations. The results show that the neglection of intraformational baffles in reservoir rocks might lead to an underestimation of mineral trapping capacity by nearly 2.5 times.
Development of modified cognitive behavioural therapy for depression in Sri Lanka
Depression is an important public health issue in Sri Lanka and an essential component of its treatment is psychotherapy. Standard Cognitive Behavioural Therapy (CBT), the most widely used psychotherapy in depression. originates in the West which has a culture and value system different from Sri Lanka. Despite multiple parallels and points of overlap between Buddhism, the majority religion in Sri Lanka, and CBT, the latter is underused in Sri Lanka. This thesis aimed to design a culturally modified cognitive behavioural therapy for depression in Sri Lanka. The thesis was conducted in two phases. Phase 1 aimed to gather the necessary information to modify the existing CBT manual to suit Sri Lanka. Phase 2 aimed to evaluate the feasibility and effects of the modified CBT manual developed in Phase 1. Phase 1 used a mixed methodology. A wide range of stakeholders including patients, carers, medical practitioners, psychologists, traditional healers and religious leaders took part in this phase of the study. The semi-structured interviews used were audio recorded, transcribed and translated. The data were analysed based on systematic content and question analysis by identifying emerging categories and themes. These results were used to develop a culturally modified CBT manual. Phase 2 was of an experimental prospective design. Patients with depression were recruited from Colombo North Teaching Hospital, Ragama, Sri Lanka, by convenient sampling. Participants were provided with 6 sessions of psychotherapy fortnightly as per the modified CBT manual and were followed up for 6 months. This was in addition to the usual treatment. Outcomes were assessed using the validated Hamilton Rating Scale for Depression (HRSD), Beck Depression Inventory II (BDI), and Global Assessment of Function (GAF) scales. Briefer and fewer psychotherapy sessions, a more didactic style of therapy and greater emphasis on behavioural therapy, family involvement in therapy and use of local literature in explaining therapy, were identified as necessary modifications to standard CBT by the participants of Phase 1. Phase 2 saw the participation of 12 patients, the majority of whom were females. Their average length of treatment for depression was 3.1 years. Their HRSD, BDI and GAF scores improved significantly at weeks 10 and 26 with better scores at 10 weeks. All patients believed that psychotherapy was useful and practical. A majority (73%, 8/11) reported the modified psychotherapy as providing them something significantly different from treatment as usual. All the clinicians reported modified CBT as being ‘feasible’ and ‘easily deliverable’. This thesis suggests that culturally modified CBT for depression is an acceptable and practical treatment option in Sri Lanka
Topographic organization of the human insular cortex and subcortex in health and neuropsychiatric illness
The structure, function and connectivity of the human brain are topographically organized. This topographic organization provides profound insight into cortical information processing, representation of mental states, and accounts for individual variation in behavioral traits and cognition. Whereas classical models of brain topography focus on distinct cortical patches defined by discrete boundaries, contemporary evidence from neuroimaging suggests that topographic variation may be better conceptualized in terms of a set of continuous gradients of gradual change that overlap in space. My work aims to reconcile these two conceptualizations of brain topography, particularly with respect to the insular cortex, a topographically complex and functionally heterogeneous cortical lobe whose organization has remained disputed for centuries. Using modern functional neuroimaging techniques, I showed that the insula’s topography is best conceptualized as a continuum of gradual change oriented along an anterior-posterior axis. I found that individual variation in the insula’s functional topography associates with human cognitive and emotional traits as well as somatosensory functions. Having characterized the functional architecture of the insular cortex in healthy adults, my next aim was to investigate whether neuropsychiatric illness is associated with alterations in the insula’s functional organization. To this end, I compared the insula’s functional connectivity gradients between individuals with schizophrenia and healthy controls. I found evidence suggesting subtle reorganization of the insula’s functional topography in schizophrenia. In particular, the connectivity profile along the anterior-posterior topographic axis of the insular cortex was altered and less differentiated in individuals with schizophrenia. I showed that the extent of reorganization of the insula’s functional topography significantly associates with the severity of clinical symptoms, particularly negative symptoms of psychosis and intellectual impairment. Finally, I applied the new methodology that I developed to map the insula’s topography to study other brain regions, including the entire human subcortex. This unveiled four hierarchical scales of subcortical organization, recapitulating well-known anatomical nuclei at the coarsest scale and delineating 27 new bilateral regions at the finest. Based on this work, I developed a new MRI subcortical atlas to enable holistic connectome mapping and characterization of cortico-subcortical circuits. The new subcortex atlas was personalized to account for connectivity differences across individuals and utilized to uncover a reproducible association between subcortical functional connectivity and tobacco use. Overall, this thesis provides fundamental insight into the functional organization of the human insular cortex and subcortex in health and neuropsychiatric illness, particularly focusing on the distinction between classical models of topographic variation based on discrete regions and contemporary representations involving continuous gradients. The new methodology that I developed is not limited to the insular cortex and the subcortex and can be applied to other cortical and subcortical regions in humans as well as other species.
Neuroimaging Biomarkers in Generalised Anxiety Disorder, and Associated Modulations Following an Anxiolytic Intervention
Introduction and Aims Generalised anxiety disorder (GAD) comprises a debilitating cluster of psychological and physiological symptoms that markedly impairs quality of life. GAD is characterised by hallmark cognitions of persistent worry and anticipatory anxiety. Evidence exists for dysregulation in excitatory/inhibitory neurobiological pathways in prefrontal and limbic brain regions, with the dorsal anterior cingulate cortex an area of particular interest. However, limited research exists assessing regional activations and the role of metabolites such as gamma-aminobutyric acid in these regions, nor modulations as a function of treatment. The aim of the thesis was to investigate the functional and metabolic features of this region, and to assess the role of neuroimaging biomarkers of anxiolytic treatment response. Methods Two investigations were conducted utilising structural features of the region of interest: task-based functional magnetic resonance blood oxygen level-dependant signal activation and GABA levels via magnetic resonance spectroscopy together with relevant psychometric and psychiatric measures. The first study was a cross-sectional investigation undertaken to compare neuroimaging biomarkers in 41 participants with GAD with 35 healthy control participants. The second study was an 8-week RCT sub-study involving 41 participants randomised to either daily 240mg of kavalactones Piper methysticum (Kava) extract or a matching placebo. This proof-of-concept study assessed the aforementioned outcomes and whether these markers signal the plant’s anxiolytic activity. Results The results of the first investigation did not reveal group differences in GABA level (p = .302). The relationship between GABA and anxiety severity was different for each group; a significant positive correlation in GAD (e.g., HAM-A, p = .018) and a negative correlation in healthy controls (e.g., trait anxiety, p = .019). The functional task was successful in eliciting regional BOLD signal differences between valent congruency conditions. Two regions exhibited significant group differences (at p < .05), showing hyperactivation in GAD and reduced activation in healthy controls. In both groups BOLD signal significantly predicted severity of state anxiety (GAD p = .027; HC p = .041). Gender, age, and comorbidity in the GAD group also influenced the biomarker-anxiety relationships. The results of the second study showed that Kava treatment was associated with a reduction to GABA levels at eight weeks (p = .049). The treatment was not associated with anxiety symptom, nor fMRI signal change, measured at eight weeks. Discussion This research investigated regional brain properties in GAD for biomarker utility, before testing them in a ‘proof of concept’ study using the purported anxiolytic agent, Kava. Metabolic and functional data were successful in producing differences in the dorsal ACC that could be (if replicated in a larger study) be utilised as biomarkers to aid in the management of GAD symptoms. Limitations of the studies were small sample sizes, GABA signal quality and equivocal toolbox results. The neurobiological effects of Kava have not been directly studied using MRI imaging in humans. The findings of a reduction to GABA levels after treatment may potentially reflect a normalising of the GABA system similar to healthy control data observed in the first study. GAD is a prevalent psychiatric disorder that is under-diagnosed and under-treated. While a great deal of work is inherent in establishing biomarkers for clinical benefit, this research contributes MRI evidence of biological differences, and insight into the mechanisms of Kava, together with a translational rationale for the study of novel anxiolytics as potential GAD treatments. The outcomes and findings of this research fit well with the current affective disorder literature and exceed contemporary work in the field of GAD biomarker and treatment research.
Development and Validation of a Diagnostic Rating Scale for Formative Assessment in a Thai EFL University Writing Classroom: A Mixed Methods Study
Aimed at identifying learners’ strengths and weaknesses on specific skills or contents, diagnostic assessment can provide fine-grained information to formatively promote teaching, learning, and language development in an ongoing language classroom (Alderson, et al., 2015, Elder, 2017; Jang, 2012; Knoch & Macqueen, 2017; Lee, 2015). While much research has developed diagnostic tools for large-scale standardised assessment, few have constructed diagnostic instruments for low-stakes formative classroom assessment. To contribute to the existing knowledge of diagnostic language assessment (e.g., Alderson et al., 2015; Jang, 2012; Knoch, 2007, 2009a, 2009b, 2011; Lee, 2015), this PhD research aimed to (1) develop a diagnostic rating scale for a formative diagnostic assessment to diagnose students’ strengths and weaknesses in academic writing products and support ongoing teaching and learning in an EFL university classroom, and (2) explore the validity of the assessment claims following an argument-based approach to validation (Chapelle et al., 2008, 2010; Kane, 1992, 2006, 2011, 2012, 2013, 2016a, 2016b; Knoch & Chapelle, 2018). To this end, this research employed a multistage exploratory sequential mixed-methods design (Creswell & Plano Clark, 2018) to undertake the scale development and validation over three study stages: scale construction, scale trialling, and scale implementation. Following the line of a multisource-driven approach to scale development (e.g., Banerjee et al., 2015; Knoch, 2007, 2009b; Montee & Malone, 2014), the scale was constructed and revised on the basis of theories of L2 writing ability, existing scales, expert intuition, and classroom curriculum. The scale was operationally implemented over the course of one semester in four writing classrooms, in which 80 English-major undergraduates used the scale to write, self-diagnose, and revise their assignment essays, and five teachers applied the scale to diagnose the students’ essays and use diagnostic results to support teaching and learning. The teachers and twenty students were interviewed regarding their perceptions of the scale and assessment. The diagnostic scores were analysed using Classical Test Theory, Many-Facets Rasch, correlation, regression, and ANOVA statistics, and the perception protocols were analysed following a qualitative content analysis. Overall, findings offered reasonable support for the overarching validity argument for the scale-driven assessment system. Yet, the different writing tasks to which the scale was applied over the course of instruction made it difficult to reliably gauge student progress, highlighting the need for stronger evidence relating to the consequence inference. This limits the usefulness of a measurement-driven assessment approach in detecting learning progression over the course. In addition, the current validation framework, driven by Kane’s argument-based approach, appeared not to well capture the dynamic and varying evidentiary sources of learning and writing development in the classroom assessment. The present study provides implications for developing a diagnostic rating scale for diagnostic purposes in a formative assessment, and examining the validity of the assessment within the context of EFL language classroom.
Optimising Web-Based Computer-Tailored Physical Activity Interventions for Prostate Cancer Survivors: A Randomised Controlled Trial Examining the Impact of Website Architecture on User Engagement
BACKGROUND: Web-based computer-tailored interventions can assist prostate cancer survivors to become more physically active by providing personally relevant behaviour change support. This study aimed to explore how changing the website architecture (free choice vs. tunnelled) impacted engagement within a physical activity computer-tailored intervention targeting prostate cancer survivors. METHODS: On a 2:2:1 ratio, 71 Australian prostate cancer survivors with local or locally advanced disease (mean age: 66.6 years ± 9.66) were randomised into either a free-choice (N = 27), tunnelled (N = 27) or minimal intervention control arm (N =17). The primary outcome was differences in usage of the physical activity self-monitoring and feedback modules between the two intervention arms. Differences in usage of other website components between the two intervention groups were explored as secondary outcomes. Further, secondary outcomes involving comparisons between all study groups (including the control) included usability, personal relevance, and behaviour change. RESULTS: The average number of physical activity self-monitoring and feedback modules accessed was higher in the tunnelled arm (M 2.6 SD 1.3) compared to the free-choice arm (M 1.5 SD 1.4), p = 0.01. However, free-choice participants were significantly more likely to have engaged with the social support (p = 0.008) and habit formation (p = 0.003) 'once-off' modules compared to the standard tunnelled arm. There were no other between-group differences found for any other study outcomes. CONCLUSION: This study indicated that website architecture influences behavioural engagement. Further research is needed to examine the impact of differential usage on mechanisms of action and behaviour change.
Non-Invasive Sheep Biometrics Obtained by Computer Vision Algorithms and Machine Learning Modeling Using Integrated Visible/Infrared Thermal Cameras
Live sheep export has become a public concern. This study aimed to test a non-contact biometric system based on artificial intelligence to assess heat stress of sheep to be potentially used as automated animal welfare assessment in farms and while in transport. Skin temperature (°C) from head features were extracted from infrared thermal videos (IRTV) using automated tracking algorithms. Two parameter engineering procedures from RGB videos were performed to assess Heart Rate (HR) in beats per minute (BPM) and respiration rate (RR) in breaths per minute (BrPM): (i) using changes in luminosity of the green (G) channel and (ii) changes in the green to red (a) from the CIELAB color scale. A supervised machine learning (ML) classification model was developed using raw RR parameters as inputs to classify cutoff frequencies for low, medium, and high respiration rate (Model 1). A supervised ML regression model was developed using raw HR and RR parameters from Model 1 (Model 2). Results showed that Models 1 and 2 were highly accurate in the estimation of RR frequency level with 96% overall accuracy (Model 1), and HR and RR with R = 0.94 and slope = 0.76 (Model 2) without statistical signs of overfitting.