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Towards clinical prediction with transparency: An explainable AI approach to survival modelling in residential aged care.
Get PDFBACKGROUND AND OBJECTIVE: Scalable, flexible and highly interpretable tools for predicting mortality in residential aged care facilities for the purpose of informing and optimizing palliative care decisions, do not exist. This study is the first and most comprehensive work applying machine learning to address this need while seeking to offer a transformative approach to integrating AI into palliative care decision-making. The objective is to predict survival in elderly individuals six months post-admission to residential aged care facilities with patient-level interpretability for transparency and support for clinical decision-making for palliative care options.
METHODS: Data from 11,944 residents across 40 facilities, with a novel combination of 18 features was used to develop predictive models, comparing standard approaches like Cox Proportional Hazards, Ridge and Lasso Regression with machine learning algorithms, Gradient Boosting (GB) and Random Survival Forest. Model calibration was performed together with ROC and a suite of evaluation metrics to analyze results. Explainable AI (XAI) tools were used to demonstrate both the cohort-level and patient-level model interpretability to enable transparency in the clinical usage of the models. TRIPOD reporting guidelines were followed, with model parameters and code provided publicly.
RESULTS: GB was the top performer with a Dynamic AUROC of 0.746 and a Concordance Index of 0.716 for six-month survival prediction. Explainable AI tools provided insights into key features such as comorbidities, cognitive impairment, and nutritional status, revealing their impact on survival outcomes and interactions that inform clinical decision-making. The calibrated model showed near-optimal performance with adjustable clinically relevant thresholds. The integration of XAI tools proved effective in enhancing the transparency and trustworthiness of predictions, offering actionable insights that support informed and ethically responsible end-of-life (EoL) care decisions in aged care settings.
CONCLUSION: This study successfully applied machine learning to create viable survival models for aged care residents, demonstrating their usability for clinical settings via a suite of interpretable tools. The findings support the introduction into clinical trials of machine learning with explainable AI tools in geriatric medicine for mortality prediction to enhance the quality of EoL care and informed discussions regarding palliative care.fals
Sputum quality affects assessment of airway microbiology in childhood asthma
Get PDFBackground: The analysis of sputum is the principal basis for characterising lower airway microbiology in those with chronic respiratory conditions. For such analysis to be informative, samples that poorly reflect the lower airways must be identified and removed. Our cross-sectional study explored the relationship between the quality of sputum samples and their microbiological content. We further investigated the impact of excluding low quality samples on observed microbiota-disease relationships in childhood asthma.
Methods: Induced sputum was collected from children with or without asthma. Sputum quality was assessed according to squamous cell%, cell viability%, detection of sputum plugs, and salivary α-amylase levels. Sputum microbiota was characterised by 16S rRNA amplicon sequencing and qPCR.
Results: Of 170 participants, 130 had asthma. Between 19% (32/170) and 29% (53/170) of samples were deemed to be of insufficient quality, depending on the quality criterion applied. Stratification of samples based on any of the sputum quality cut-offs resulted in significant differences in microbiota characteristics (all p < 0.05), with salivary α-amylase the least discriminant between microbiota of acceptable and unacceptable samples. The removal of 53 poor-quality samples based on ≥ 30% squamous cells identified a difference in the sputum microbiota by asthma status (p = 0.017) that was not evident otherwise, including significantly higher levels of Haemophilus and Gemella in asthma samples.
Conclusions: Upper airway contamination of induced sputum samples from children is common. Exclusion of samples based on ≥ 30% squamous cells enables identification of asthma-airway microbiology relationships that are otherwise not apparent.fals
Belowground Structural Attributes and Morpho-Anatomical Response Strategies of Bromus valdivianus Phil and Lolium perenne L to Soil Water Restriction
Get PDFThe effect of soil water restriction on the root structure and morpho-anatomical attributes of Lolium perenne L. (Lp) and Bromus valdivianus Phil. (Bv) was investigated. The anatomical structure of roots from plants grown under two water restriction conditions (20–25% and 80–85% field capacity (FC)) were assessed using paraffin embedding and thin sections. These sections were examined to assess anatomical traits, including root diameter (root D), stele diameter (stele D) and cortex thickness (cortex T), and xylem vessel of Lp and Bv roots. Tiller population, shoot herbage mass, and the shoot-to-root ratio were also determined. Under water restriction, biomass and tillers were significantly decreased (p < 0.001), while the root-to-shoot ratio significantly increased, indicating a higher proportion of Bv roots than shoots when compared to Lp. The root D and stele D, and cortex T, were larger in Bv than in Lp (p < 0.001), indicating a greater adaptation of Bv for water uptake and storage compared to Lp. Xylem vessels were wider in Lp when compared to Bv (p < 0.01), indicating greater water flow within the plant. Water restriction generated a decrease in root D, stele D, and cortex T (p < 0.01). Canonical variate analysis showed that the pith cell wall had a strong positive relationship with water restriction in both Bv and Lp; lignified xylem and the endodermis wall had a close relationship with Lp under water restriction. The findings demonstrate that Lp and Bv have individual structural and morpho-anatomical response strategies to increasing water restriction.fals
A female text in chorus : a thesis presented in fulfilment of the requirements for the degree of Masters in Creative Writing at Massey University, New Zealand. EMBARGOED until 27th May 2027
No full textEmbargoed until 27th May 2027Two voices. Many questions. A call, a refrain, a response. Is the language with which we write masculine in nature due to its birth through patriarchal means? Can it become feminine? How might women writers represent and reinvent themselves in text, or reclaim the very concept of text itself? My critical essay examines Irish writer Doireann Ní Ghríofa’s book A Ghost in the Throat (2021) through the lens of Hélène Cixous’ formative feminist article, “The Laugh of the Medusa” (1975), in which she presents a call to arms for women to write themselves into text in distinctly female ways. As these women’s voices call and respond across the decades, a female text is written and defined, examined and redefined, and both Cixous and Ní Ghríofa offer crucial contributions to literature that are distinctly female in plight and song. My own voice joins the chorus in the creative portion of my thesis – a memoir that weaves together scenes from the decade I spent raising my children in rural Guatemala and the first months in which I return to New Zealand after my husband leaves us. It explores the shock, grief and shift of identity that arises after he leaves, as I navigate the seas of solo motherhood and seek a new sense of home. Together, the creative and critical aspects of this thesis examine the rising of the female voice from the margins of literature, and the discovery that our voices in fact sing together in one chorus
Faithful subjectivities : narrative portrayals of a Christian social imaginary : a thesis presented in partial fulfilment of the requirements for the degree of Master of Arts in English at Massey University, Manawatū campus, New Zealand
Get PDFThis thesis argues that the novel has provided a means of expressing Christian social imaginaries, or models of reality, through attempts to give narrative form to the identity and experience of individual believers that I term faithful subjectivity. Faithful subjectivity refers to the portrayal of individual self-understanding and behaviour that is rooted in the Christian metanarrative and participates simultaneously in the material and spiritual dimensions of its understanding of the world and the cosmos. This thesis thereby highlights the seeming paradox whereby writers turn to fiction to articulate and explore theological verities. It considers three novels from different literary periods, which each conform to different genre norms and are shaped by different theological traditions: John Bunyan’s The Pilgrim’s Progress (1678), C. S. Lewis’s Perelandra (1943), and Marilynne Robinson’s Gilead (2004). My central contention is that these novelistic expressions of faithful subjectivity are each centred around distinctive organising metaphors: Bunyan famously presents faith as a journey in Pilgrim’s Progress, whereas Lewis frames it in terms of total war in Perelandra, and Robinson expresses faith as a matter of perception in Gilead. The analysis of each novel is situated in its historical and cultural contexts, as well as in light of its author’s theological dispositions, in order to better grasp the particular metaphor that it employs as a model of faithful subjectivity. I then consider the affordances and limitations of each structuring metaphor. This inquiry provides cultural and historical depth for broader conversations about the articulation of a Christian social imaginary alongside and in tension with the emergence of secular western subjectivity that has long been associated with the rise of the novel
Using test cases to refute incorrect existentially quantified propositions: An exploratory study
Get PDFTowards the goal of extending the applicability of test cases to the context of existentially quantified propositions, the present study explores how test cases might support learners with refuting their incorrect existentially quantified propositions. We present and analyze data from two separate instances in which two in-service primary school teachers initially made incorrect existentially quantified propositions and then were asked to find a valid example of their respective propositions (i.e., an element of the subject that satisfies the predicate). The participants were given, and sometimes generated their own, test cases which led to an iterative process of ruling out potential examples and classes of potential examples. Our analysis of this iterative process as it emerged within our specific research setting, comprising among aspects, particular researcher-participant interactions, sheds light on how these test cases afford and support the development and refinement of the learners’ respective existentially quantified propositions.fals
Understanding the evolution of scoria cone morphology using multivariate models
Get PDFScoria cones are the most abundant type of volcano in the Solar System. They occur in every tectonic setting and often overlap with human populations, yet our ability to provide complete geochronology within volcanic fields remains limited. Appropriate geochronology underpins the reconstruction of size-frequency distribution and is a key input for robust volcanic hazard assessment. Morphometric data have long been used to estimate relative ages of scoria cones; however, they have only shown promise at single volcanic fields and simple cones with homogenous pyroclastics. Here, we present a new global inventory of dated scoria cones (n = 572) from 71 volcanic fields formed under diverse magmatic, tectonic and climatic regimes, and build data-driven age models for dating scoria cones using easily accessible morphometric, reflectance and climatic variables. Our models suggest chemical composition of ascending magma may influence the initial scoria cone morphology which is then gradually modified by erosion over time. (Figure presented.)fals
Locally energy-stable finite element schemes for incompressible flow problems: Design and analysis for equal-order interpolations
Get PDFWe show that finite element discretizations of incompressible flow problems can be designed to ensure preservation/dissipation of kinetic energy not only globally but also locally. In the context of equal-order (piecewise-linear) interpolations, we prove the validity of a semi-discrete energy inequality for a quadrature-based approximation to the nonlinear convective term, which we combine with the Becker–Hansbo pressure stabilization. An analogy with entropy-stable algebraic flux correction schemes for the compressible Euler equations and the shallow water equations yields a weak ‘bounded variation’ estimate from which we deduce the semi-discrete Lax–Wendroff consistency and convergence towards dissipative weak solutions. The results of our numerical experiments for standard test problems confirm that the method under investigation is non-oscillatory and exhibits optimal convergence behavior.fals
Suspected brodifacoum poisoning in tuatara (Sphenodon punctatus)
Get PDFCase history: Between June 2017 and April 2019, three captive tuatara from a zoological facility in the South Island of New Zealand were found unwell and admitted to veterinary care. One other tuatara from the same facility was found dead from misadventure in May 2019.
Clinical findings: All three unwell tuatara showed clinical signs of lethargy, mucous membrane pallor, and dehydration, with haematoma formation/swelling in dependent parts of the body. Fine needle aspiration and cytology of the swellings showed common features of peripheral blood, with variable other cytological findings. Haematology confirmed marked anaemia in Case 1 (PCV 5%; reference range 22–53%) and Case 2 (PCV 1%) and suspected mild anaemia in Case 3 (PCV 27%). Case 1 died 6 weeks after initial presentation, whereas Cases 2 and 3 died soon after presentation.
Pathological findings: Post-mortem examination showed general pallor of soft tissues in the three tuatara with clinical signs of coagulopathy. There was haemorrhage in the bladder wall of Case 1, while Cases 2 and 3 had haematomas (subcutaneous in Case 2 and peri-oesophageal in Case 3). The pathological diagnosis in Case 4 was death by asphyxiation following burrow collapse. Retrospective analysis showed brodifacoum was present in liver tissue at a concentration of 0.26 mg/kg in Case 3, and in skeletal muscle tissue at concentrations of 0.019 mg/kg in Case 2 and 0.035 mg/kg in the non-clinical case (Case 4).
Diagnosis: The clinical signs and post-mortem findings were consistent with anticoagulant poisoning in three tuatara, and tissue concentrations of brodifacoum demonstrated exposure in three animals, including one animal with no clinical signs of coagulopathy (Case 4). Definitive diagnosis was prevented, however, by inconsistent toxicology testing and a limited understanding of toxicity thresholds in reptiles in general, and tuatara specifically.
Clinical relevance: This case series suggests that tuatara are susceptible to anticoagulant poisoning and this has implications for both the captive management of tuatara, and also the use of rodenticides in tuatara habitat, such as offshore islands and mainland sanctuaries.fals
Zodiac Year Fate Eased by CSR: Fact or Fiction?
No full textThis study examines the relationship between the Chinese zodiac year of chairpersons and corporate social responsibility (CSR) performance. Drawing on upper echelons and stakeholder theories, we argue that zodiac beliefs may lead chairpersons to prioritise CSR activities during their zodiac year to counteract potential bad luck and mitigate corporate risk. Using 24,418 observations from Chinese listed firms over the period 2010–2020, our empirical analysis reveals a significant and positive effect of chairpersons' zodiac year on CSR performance. We observe that the effect is transient, appearing before and during the zodiac year but diminishing thereafter. Further, our findings show that the zodiac year effect is more pronounced in state-owned enterprises, firms with higher levels of public, environmental and CSR concerns and those with favourable environmental track records. This study extends the application of upper echelons and stakeholder theories by incorporating chairpersons’ zodiac year effect.fals